File: [local] / src / sys / net / pf.c (download)
Revision 1.1196, Tue May 14 08:26:13 2024 UTC (4 weeks ago) by jsg
Branch: MAIN
Changes since 1.1195: +1 -3 lines
remove prototypes with no matching function
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/* $OpenBSD: pf.c,v 1.1196 2024/05/14 08:26:13 jsg Exp $ */
/*
* Copyright (c) 2001 Daniel Hartmeier
* Copyright (c) 2002 - 2013 Henning Brauer <henning@openbsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Effort sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F30602-01-2-0537.
*
*/
#include "bpfilter.h"
#include "carp.h"
#include "pflog.h"
#include "pfsync.h"
#include "pflow.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/filio.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <crypto/sha2.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/toeplitz.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_fsm.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip_divert.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_divert.h>
#endif /* INET6 */
#include <net/pfvar.h>
#include <net/pfvar_priv.h>
#if NPFLOG > 0
#include <net/if_pflog.h>
#endif /* NPFLOG > 0 */
#if NPFLOW > 0
#include <net/if_pflow.h>
#endif /* NPFLOW > 0 */
#if NPFSYNC > 0
#include <net/if_pfsync.h>
#endif /* NPFSYNC > 0 */
/*
* Global variables
*/
struct pf_state_tree pf_statetbl;
struct pf_queuehead pf_queues[2];
struct pf_queuehead *pf_queues_active;
struct pf_queuehead *pf_queues_inactive;
struct pf_status pf_status;
struct mutex pf_inp_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);
int pf_hdr_limit = 20; /* arbitrary limit, tune in ddb */
SHA2_CTX pf_tcp_secret_ctx;
u_char pf_tcp_secret[16];
int pf_tcp_secret_init;
int pf_tcp_iss_off;
enum pf_test_status {
PF_TEST_FAIL = -1,
PF_TEST_OK,
PF_TEST_QUICK
};
struct pf_test_ctx {
struct pf_pdesc *pd;
struct pf_rule_actions act;
u_int8_t icmpcode;
u_int8_t icmptype;
int icmp_dir;
int state_icmp;
int tag;
u_short reason;
struct pf_rule_item *ri;
struct pf_src_node *sns[PF_SN_MAX];
struct pf_rule_slist rules;
struct pf_rule *nr;
struct pf_rule **rm;
struct pf_rule *a;
struct pf_rule **am;
struct pf_ruleset **rsm;
struct pf_ruleset *arsm;
struct pf_ruleset *aruleset;
struct tcphdr *th;
};
struct pool pf_src_tree_pl, pf_rule_pl, pf_queue_pl;
struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl;
struct pool pf_rule_item_pl, pf_sn_item_pl, pf_pktdelay_pl;
void pf_add_threshold(struct pf_threshold *);
int pf_check_threshold(struct pf_threshold *);
int pf_check_tcp_cksum(struct mbuf *, int, int,
sa_family_t);
__inline void pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t,
u_int8_t);
void pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *,
const struct pf_addr *, sa_family_t, u_int8_t);
int pf_modulate_sack(struct pf_pdesc *,
struct pf_state_peer *);
int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *,
u_int16_t *, u_int16_t *);
int pf_change_icmp_af(struct mbuf *, int,
struct pf_pdesc *, struct pf_pdesc *,
struct pf_addr *, struct pf_addr *, sa_family_t,
sa_family_t);
int pf_translate_a(struct pf_pdesc *, struct pf_addr *,
struct pf_addr *);
void pf_translate_icmp(struct pf_pdesc *, struct pf_addr *,
u_int16_t *, struct pf_addr *, struct pf_addr *,
u_int16_t);
int pf_translate_icmp_af(struct pf_pdesc*, int, void *);
void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int,
sa_family_t, struct pf_rule *, u_int);
void pf_detach_state(struct pf_state *);
struct pf_state_key *pf_state_key_attach(struct pf_state_key *,
struct pf_state *, int);
void pf_state_key_detach(struct pf_state *, int);
u_int32_t pf_tcp_iss(struct pf_pdesc *);
void pf_rule_to_actions(struct pf_rule *,
struct pf_rule_actions *);
int pf_test_rule(struct pf_pdesc *, struct pf_rule **,
struct pf_state **, struct pf_rule **,
struct pf_ruleset **, u_short *);
static __inline int pf_create_state(struct pf_pdesc *, struct pf_rule *,
struct pf_rule *, struct pf_rule *,
struct pf_state_key **, struct pf_state_key **,
int *, struct pf_state **, int,
struct pf_rule_slist *, struct pf_rule_actions *,
struct pf_src_node **);
static __inline int pf_state_key_addr_setup(struct pf_pdesc *, void *,
int, struct pf_addr *, int, struct pf_addr *,
int, int);
int pf_state_key_setup(struct pf_pdesc *, struct
pf_state_key **, struct pf_state_key **, int);
int pf_tcp_track_full(struct pf_pdesc *,
struct pf_state **, u_short *, int *, int);
int pf_tcp_track_sloppy(struct pf_pdesc *,
struct pf_state **, u_short *);
static __inline int pf_synproxy(struct pf_pdesc *, struct pf_state **,
u_short *);
int pf_test_state(struct pf_pdesc *, struct pf_state **,
u_short *);
int pf_icmp_state_lookup(struct pf_pdesc *,
struct pf_state_key_cmp *, struct pf_state **,
u_int16_t, u_int16_t, int, int *, int, int);
int pf_test_state_icmp(struct pf_pdesc *,
struct pf_state **, u_short *);
u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, int,
u_int16_t);
static __inline int pf_set_rt_ifp(struct pf_state *, struct pf_addr *,
sa_family_t, struct pf_src_node **);
struct pf_divert *pf_get_divert(struct mbuf *);
int pf_walk_option(struct pf_pdesc *, struct ip *,
int, int, u_short *);
int pf_walk_header(struct pf_pdesc *, struct ip *,
u_short *);
int pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *,
int, int, u_short *);
int pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *,
u_short *);
void pf_print_state_parts(struct pf_state *,
struct pf_state_key *, struct pf_state_key *);
int pf_addr_wrap_neq(struct pf_addr_wrap *,
struct pf_addr_wrap *);
int pf_compare_state_keys(struct pf_state_key *,
struct pf_state_key *, struct pfi_kif *, u_int);
u_int16_t pf_pkt_hash(sa_family_t, uint8_t,
const struct pf_addr *, const struct pf_addr *,
uint16_t, uint16_t);
int pf_find_state(struct pf_pdesc *,
struct pf_state_key_cmp *, struct pf_state **);
int pf_src_connlimit(struct pf_state **);
int pf_match_rcvif(struct mbuf *, struct pf_rule *);
enum pf_test_status pf_match_rule(struct pf_test_ctx *,
struct pf_ruleset *);
void pf_counters_inc(int, struct pf_pdesc *,
struct pf_state *, struct pf_rule *,
struct pf_rule *);
int pf_state_insert(struct pfi_kif *,
struct pf_state_key **, struct pf_state_key **,
struct pf_state *);
int pf_state_key_isvalid(struct pf_state_key *);
struct pf_state_key *pf_state_key_ref(struct pf_state_key *);
void pf_state_key_unref(struct pf_state_key *);
void pf_state_key_link_reverse(struct pf_state_key *,
struct pf_state_key *);
void pf_state_key_unlink_reverse(struct pf_state_key *);
void pf_state_key_link_inpcb(struct pf_state_key *,
struct inpcb *);
void pf_state_key_unlink_inpcb(struct pf_state_key *);
void pf_pktenqueue_delayed(void *);
int32_t pf_state_expires(const struct pf_state *, uint8_t);
#if NPFLOG > 0
void pf_log_matches(struct pf_pdesc *, struct pf_rule *,
struct pf_rule *, struct pf_ruleset *,
struct pf_rule_slist *);
#endif /* NPFLOG > 0 */
extern struct pool pfr_ktable_pl;
extern struct pool pfr_kentry_pl;
struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = {
{ &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT },
{ &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT },
{ &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT },
{ &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT },
{ &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT },
{ &pf_pktdelay_pl, PF_PKTDELAY_MAXPKTS, PF_PKTDELAY_MAXPKTS },
{ &pf_anchor_pl, PF_ANCHOR_HIWAT, PF_ANCHOR_HIWAT }
};
#define BOUND_IFACE(r, k) \
((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all
#define STATE_INC_COUNTERS(s) \
do { \
struct pf_rule_item *mrm; \
s->rule.ptr->states_cur++; \
s->rule.ptr->states_tot++; \
if (s->anchor.ptr != NULL) { \
s->anchor.ptr->states_cur++; \
s->anchor.ptr->states_tot++; \
} \
SLIST_FOREACH(mrm, &s->match_rules, entry) \
mrm->r->states_cur++; \
} while (0)
static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *);
static inline int pf_state_compare_key(const struct pf_state_key *,
const struct pf_state_key *);
static inline int pf_state_compare_id(const struct pf_state *,
const struct pf_state *);
#ifdef INET6
static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t);
static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t);
#endif /* INET6 */
static __inline void pf_set_protostate(struct pf_state *, int, u_int8_t);
struct pf_src_tree tree_src_tracking;
struct pf_state_tree_id tree_id;
struct pf_state_list pf_state_list = PF_STATE_LIST_INITIALIZER(pf_state_list);
RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare);
RBT_GENERATE(pf_state_tree, pf_state_key, sk_entry, pf_state_compare_key);
RBT_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id);
int
pf_addr_compare(const struct pf_addr *a, const struct pf_addr *b,
sa_family_t af)
{
switch (af) {
case AF_INET:
if (a->addr32[0] > b->addr32[0])
return (1);
if (a->addr32[0] < b->addr32[0])
return (-1);
break;
#ifdef INET6
case AF_INET6:
if (a->addr32[3] > b->addr32[3])
return (1);
if (a->addr32[3] < b->addr32[3])
return (-1);
if (a->addr32[2] > b->addr32[2])
return (1);
if (a->addr32[2] < b->addr32[2])
return (-1);
if (a->addr32[1] > b->addr32[1])
return (1);
if (a->addr32[1] < b->addr32[1])
return (-1);
if (a->addr32[0] > b->addr32[0])
return (1);
if (a->addr32[0] < b->addr32[0])
return (-1);
break;
#endif /* INET6 */
}
return (0);
}
static __inline int
pf_src_compare(struct pf_src_node *a, struct pf_src_node *b)
{
int diff;
if (a->rule.ptr > b->rule.ptr)
return (1);
if (a->rule.ptr < b->rule.ptr)
return (-1);
if ((diff = a->type - b->type) != 0)
return (diff);
if ((diff = a->af - b->af) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0)
return (diff);
return (0);
}
static __inline void
pf_set_protostate(struct pf_state *st, int which, u_int8_t newstate)
{
if (which == PF_PEER_DST || which == PF_PEER_BOTH)
st->dst.state = newstate;
if (which == PF_PEER_DST)
return;
if (st->src.state == newstate)
return;
if (st->creatorid == pf_status.hostid &&
st->key[PF_SK_STACK]->proto == IPPROTO_TCP &&
!(TCPS_HAVEESTABLISHED(st->src.state) ||
st->src.state == TCPS_CLOSED) &&
(TCPS_HAVEESTABLISHED(newstate) || newstate == TCPS_CLOSED))
pf_status.states_halfopen--;
st->src.state = newstate;
}
void
pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af)
{
switch (af) {
case AF_INET:
dst->addr32[0] = src->addr32[0];
break;
#ifdef INET6
case AF_INET6:
dst->addr32[0] = src->addr32[0];
dst->addr32[1] = src->addr32[1];
dst->addr32[2] = src->addr32[2];
dst->addr32[3] = src->addr32[3];
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
}
void
pf_init_threshold(struct pf_threshold *threshold,
u_int32_t limit, u_int32_t seconds)
{
threshold->limit = limit * PF_THRESHOLD_MULT;
threshold->seconds = seconds;
threshold->count = 0;
threshold->last = getuptime();
}
void
pf_add_threshold(struct pf_threshold *threshold)
{
u_int32_t t = getuptime(), diff = t - threshold->last;
if (diff >= threshold->seconds)
threshold->count = 0;
else
threshold->count -= threshold->count * diff /
threshold->seconds;
threshold->count += PF_THRESHOLD_MULT;
threshold->last = t;
}
int
pf_check_threshold(struct pf_threshold *threshold)
{
return (threshold->count > threshold->limit);
}
void
pf_state_list_insert(struct pf_state_list *pfs, struct pf_state *st)
{
/*
* we can always put states on the end of the list.
*
* things reading the list should take a read lock, then
* the mutex, get the head and tail pointers, release the
* mutex, and then they can iterate between the head and tail.
*/
pf_state_ref(st); /* get a ref for the list */
mtx_enter(&pfs->pfs_mtx);
TAILQ_INSERT_TAIL(&pfs->pfs_list, st, entry_list);
mtx_leave(&pfs->pfs_mtx);
}
void
pf_state_list_remove(struct pf_state_list *pfs, struct pf_state *st)
{
/* states can only be removed when the write lock is held */
rw_assert_wrlock(&pfs->pfs_rwl);
mtx_enter(&pfs->pfs_mtx);
TAILQ_REMOVE(&pfs->pfs_list, st, entry_list);
mtx_leave(&pfs->pfs_mtx);
pf_state_unref(st); /* list no longer references the state */
}
void
pf_update_state_timeout(struct pf_state *st, int to)
{
mtx_enter(&st->mtx);
if (st->timeout != PFTM_UNLINKED)
st->timeout = to;
mtx_leave(&st->mtx);
}
int
pf_src_connlimit(struct pf_state **stp)
{
int bad = 0;
struct pf_src_node *sn;
if ((sn = pf_get_src_node((*stp), PF_SN_NONE)) == NULL)
return (0);
sn->conn++;
(*stp)->src.tcp_est = 1;
pf_add_threshold(&sn->conn_rate);
if ((*stp)->rule.ptr->max_src_conn &&
(*stp)->rule.ptr->max_src_conn < sn->conn) {
pf_status.lcounters[LCNT_SRCCONN]++;
bad++;
}
if ((*stp)->rule.ptr->max_src_conn_rate.limit &&
pf_check_threshold(&sn->conn_rate)) {
pf_status.lcounters[LCNT_SRCCONNRATE]++;
bad++;
}
if (!bad)
return (0);
if ((*stp)->rule.ptr->overload_tbl) {
struct pfr_addr p;
u_int32_t killed = 0;
pf_status.lcounters[LCNT_OVERLOAD_TABLE]++;
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: pf_src_connlimit: blocking address ");
pf_print_host(&sn->addr, 0,
(*stp)->key[PF_SK_WIRE]->af);
}
memset(&p, 0, sizeof(p));
p.pfra_af = (*stp)->key[PF_SK_WIRE]->af;
switch ((*stp)->key[PF_SK_WIRE]->af) {
case AF_INET:
p.pfra_net = 32;
p.pfra_ip4addr = sn->addr.v4;
break;
#ifdef INET6
case AF_INET6:
p.pfra_net = 128;
p.pfra_ip6addr = sn->addr.v6;
break;
#endif /* INET6 */
}
pfr_insert_kentry((*stp)->rule.ptr->overload_tbl,
&p, gettime());
/* kill existing states if that's required. */
if ((*stp)->rule.ptr->flush) {
struct pf_state_key *sk;
struct pf_state *st;
pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++;
RBT_FOREACH(st, pf_state_tree_id, &tree_id) {
sk = st->key[PF_SK_WIRE];
/*
* Kill states from this source. (Only those
* from the same rule if PF_FLUSH_GLOBAL is not
* set)
*/
if (sk->af ==
(*stp)->key[PF_SK_WIRE]->af &&
(((*stp)->direction == PF_OUT &&
PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) ||
((*stp)->direction == PF_IN &&
PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) &&
((*stp)->rule.ptr->flush &
PF_FLUSH_GLOBAL ||
(*stp)->rule.ptr == st->rule.ptr)) {
pf_update_state_timeout(st, PFTM_PURGE);
pf_set_protostate(st, PF_PEER_BOTH,
TCPS_CLOSED);
killed++;
}
}
if (pf_status.debug >= LOG_NOTICE)
addlog(", %u states killed", killed);
}
if (pf_status.debug >= LOG_NOTICE)
addlog("\n");
}
/* kill this state */
pf_update_state_timeout(*stp, PFTM_PURGE);
pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_CLOSED);
return (1);
}
int
pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule,
enum pf_sn_types type, sa_family_t af, struct pf_addr *src,
struct pf_addr *raddr, struct pfi_kif *kif)
{
struct pf_src_node k;
if (*sn == NULL) {
k.af = af;
k.type = type;
pf_addrcpy(&k.addr, src, af);
k.rule.ptr = rule;
pf_status.scounters[SCNT_SRC_NODE_SEARCH]++;
*sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k);
}
if (*sn == NULL) {
if (!rule->max_src_nodes ||
rule->src_nodes < rule->max_src_nodes)
(*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO);
else
pf_status.lcounters[LCNT_SRCNODES]++;
if ((*sn) == NULL)
return (-1);
pf_init_threshold(&(*sn)->conn_rate,
rule->max_src_conn_rate.limit,
rule->max_src_conn_rate.seconds);
(*sn)->type = type;
(*sn)->af = af;
(*sn)->rule.ptr = rule;
pf_addrcpy(&(*sn)->addr, src, af);
if (raddr)
pf_addrcpy(&(*sn)->raddr, raddr, af);
if (RB_INSERT(pf_src_tree,
&tree_src_tracking, *sn) != NULL) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: src_tree insert failed: ");
pf_print_host(&(*sn)->addr, 0, af);
addlog("\n");
}
pool_put(&pf_src_tree_pl, *sn);
return (-1);
}
(*sn)->creation = getuptime();
(*sn)->rule.ptr->src_nodes++;
if (kif != NULL) {
(*sn)->kif = kif;
pfi_kif_ref(kif, PFI_KIF_REF_SRCNODE);
}
pf_status.scounters[SCNT_SRC_NODE_INSERT]++;
pf_status.src_nodes++;
} else {
if (rule->max_src_states &&
(*sn)->states >= rule->max_src_states) {
pf_status.lcounters[LCNT_SRCSTATES]++;
return (-1);
}
}
return (0);
}
void
pf_remove_src_node(struct pf_src_node *sn)
{
if (sn->states > 0 || sn->expire > getuptime())
return;
sn->rule.ptr->src_nodes--;
if (sn->rule.ptr->states_cur == 0 &&
sn->rule.ptr->src_nodes == 0)
pf_rm_rule(NULL, sn->rule.ptr);
RB_REMOVE(pf_src_tree, &tree_src_tracking, sn);
pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++;
pf_status.src_nodes--;
pfi_kif_unref(sn->kif, PFI_KIF_REF_SRCNODE);
pool_put(&pf_src_tree_pl, sn);
}
struct pf_src_node *
pf_get_src_node(struct pf_state *st, enum pf_sn_types type)
{
struct pf_sn_item *sni;
SLIST_FOREACH(sni, &st->src_nodes, next)
if (sni->sn->type == type)
return (sni->sn);
return (NULL);
}
void
pf_state_rm_src_node(struct pf_state *st, struct pf_src_node *sn)
{
struct pf_sn_item *sni, *snin, *snip = NULL;
for (sni = SLIST_FIRST(&st->src_nodes); sni; sni = snin) {
snin = SLIST_NEXT(sni, next);
if (sni->sn == sn) {
if (snip)
SLIST_REMOVE_AFTER(snip, next);
else
SLIST_REMOVE_HEAD(&st->src_nodes, next);
pool_put(&pf_sn_item_pl, sni);
sni = NULL;
sn->states--;
}
if (sni != NULL)
snip = sni;
}
}
/* state table stuff */
static inline int
pf_state_compare_key(const struct pf_state_key *a,
const struct pf_state_key *b)
{
int diff;
if ((diff = a->hash - b->hash) != 0)
return (diff);
if ((diff = a->proto - b->proto) != 0)
return (diff);
if ((diff = a->af - b->af) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0)
return (diff);
if ((diff = a->port[0] - b->port[0]) != 0)
return (diff);
if ((diff = a->port[1] - b->port[1]) != 0)
return (diff);
if ((diff = a->rdomain - b->rdomain) != 0)
return (diff);
return (0);
}
static inline int
pf_state_compare_id(const struct pf_state *a, const struct pf_state *b)
{
if (a->id > b->id)
return (1);
if (a->id < b->id)
return (-1);
if (a->creatorid > b->creatorid)
return (1);
if (a->creatorid < b->creatorid)
return (-1);
return (0);
}
/*
* on failure, pf_state_key_attach() releases the pf_state_key
* reference and returns NULL.
*/
struct pf_state_key *
pf_state_key_attach(struct pf_state_key *sk, struct pf_state *st, int idx)
{
struct pf_state_item *si;
struct pf_state_key *cur;
struct pf_state *oldst = NULL;
PF_ASSERT_LOCKED();
KASSERT(st->key[idx] == NULL);
sk->sk_removed = 0;
cur = RBT_INSERT(pf_state_tree, &pf_statetbl, sk);
if (cur != NULL) {
sk->sk_removed = 1;
/* key exists. check for same kif, if none, add to key */
TAILQ_FOREACH(si, &cur->sk_states, si_entry) {
struct pf_state *sist = si->si_st;
if (sist->kif == st->kif &&
((sist->key[PF_SK_WIRE]->af == sk->af &&
sist->direction == st->direction) ||
(sist->key[PF_SK_WIRE]->af !=
sist->key[PF_SK_STACK]->af &&
sk->af == sist->key[PF_SK_STACK]->af &&
sist->direction != st->direction))) {
int reuse = 0;
if (sk->proto == IPPROTO_TCP &&
sist->src.state >= TCPS_FIN_WAIT_2 &&
sist->dst.state >= TCPS_FIN_WAIT_2)
reuse = 1;
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: %s key attach %s on %s: ",
(idx == PF_SK_WIRE) ?
"wire" : "stack",
reuse ? "reuse" : "failed",
st->kif->pfik_name);
pf_print_state_parts(st,
(idx == PF_SK_WIRE) ? sk : NULL,
(idx == PF_SK_STACK) ? sk : NULL);
addlog(", existing: ");
pf_print_state_parts(sist,
(idx == PF_SK_WIRE) ? sk : NULL,
(idx == PF_SK_STACK) ? sk : NULL);
addlog("\n");
}
if (reuse) {
pf_set_protostate(sist, PF_PEER_BOTH,
TCPS_CLOSED);
/* remove late or sks can go away */
oldst = sist;
} else {
pf_state_key_unref(sk);
return (NULL); /* collision! */
}
}
}
/* reuse the existing state key */
pf_state_key_unref(sk);
sk = cur;
}
if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) {
if (TAILQ_EMPTY(&sk->sk_states)) {
KASSERT(cur == NULL);
RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
sk->sk_removed = 1;
pf_state_key_unref(sk);
}
return (NULL);
}
st->key[idx] = pf_state_key_ref(sk); /* give a ref to state */
si->si_st = pf_state_ref(st);
/* list is sorted, if-bound states before floating */
if (st->kif == pfi_all)
TAILQ_INSERT_TAIL(&sk->sk_states, si, si_entry);
else
TAILQ_INSERT_HEAD(&sk->sk_states, si, si_entry);
if (oldst)
pf_remove_state(oldst);
/* caller owns the pf_state ref, which owns a pf_state_key ref now */
return (sk);
}
void
pf_detach_state(struct pf_state *st)
{
KASSERT(st->key[PF_SK_WIRE] != NULL);
pf_state_key_detach(st, PF_SK_WIRE);
KASSERT(st->key[PF_SK_STACK] != NULL);
if (st->key[PF_SK_STACK] != st->key[PF_SK_WIRE])
pf_state_key_detach(st, PF_SK_STACK);
}
void
pf_state_key_detach(struct pf_state *st, int idx)
{
struct pf_state_item *si;
struct pf_state_key *sk;
PF_ASSERT_LOCKED();
sk = st->key[idx];
if (sk == NULL)
return;
TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
if (si->si_st == st)
break;
}
if (si == NULL)
return;
TAILQ_REMOVE(&sk->sk_states, si, si_entry);
pool_put(&pf_state_item_pl, si);
if (TAILQ_EMPTY(&sk->sk_states)) {
RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
sk->sk_removed = 1;
pf_state_key_unlink_reverse(sk);
pf_state_key_unlink_inpcb(sk);
pf_state_key_unref(sk);
}
pf_state_unref(st);
}
struct pf_state_key *
pf_alloc_state_key(int pool_flags)
{
struct pf_state_key *sk;
if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL)
return (NULL);
PF_REF_INIT(sk->sk_refcnt);
TAILQ_INIT(&sk->sk_states);
sk->sk_removed = 1;
return (sk);
}
static __inline int
pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx,
struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi)
{
struct pf_state_key_cmp *key = arg;
#ifdef INET6
struct pf_addr *target;
if (af == AF_INET || pd->proto != IPPROTO_ICMPV6)
goto copy;
switch (pd->hdr.icmp6.icmp6_type) {
case ND_NEIGHBOR_SOLICIT:
if (multi)
return (-1);
target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
daddr = target;
break;
case ND_NEIGHBOR_ADVERT:
if (multi)
return (-1);
target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
saddr = target;
if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) {
key->addr[didx].addr32[0] = 0;
key->addr[didx].addr32[1] = 0;
key->addr[didx].addr32[2] = 0;
key->addr[didx].addr32[3] = 0;
daddr = NULL; /* overwritten */
}
break;
default:
if (multi) {
key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL;
key->addr[sidx].addr32[1] = 0;
key->addr[sidx].addr32[2] = 0;
key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE;
saddr = NULL; /* overwritten */
}
}
copy:
#endif /* INET6 */
if (saddr)
pf_addrcpy(&key->addr[sidx], saddr, af);
if (daddr)
pf_addrcpy(&key->addr[didx], daddr, af);
return (0);
}
int
pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw,
struct pf_state_key **sks, int rtableid)
{
/* if returning error we MUST pool_put state keys ourselves */
struct pf_state_key *sk1, *sk2;
u_int wrdom = pd->rdomain;
int afto = pd->af != pd->naf;
if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL)
return (ENOMEM);
pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst,
pd->af, 0);
sk1->port[pd->sidx] = pd->osport;
sk1->port[pd->didx] = pd->odport;
sk1->proto = pd->proto;
sk1->af = pd->af;
sk1->rdomain = pd->rdomain;
sk1->hash = pf_pkt_hash(sk1->af, sk1->proto,
&sk1->addr[0], &sk1->addr[1], sk1->port[0], sk1->port[1]);
if (rtableid >= 0)
wrdom = rtable_l2(rtableid);
if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) ||
PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) ||
pd->nsport != pd->osport || pd->ndport != pd->odport ||
wrdom != pd->rdomain || afto) { /* NAT/NAT64 */
if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) {
pf_state_key_unref(sk1);
return (ENOMEM);
}
pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx,
&pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr,
pd->naf, 0);
sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport;
sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport;
if (afto) {
switch (pd->proto) {
case IPPROTO_ICMP:
sk2->proto = IPPROTO_ICMPV6;
break;
case IPPROTO_ICMPV6:
sk2->proto = IPPROTO_ICMP;
break;
default:
sk2->proto = pd->proto;
}
} else
sk2->proto = pd->proto;
sk2->af = pd->naf;
sk2->rdomain = wrdom;
sk2->hash = pf_pkt_hash(sk2->af, sk2->proto,
&sk2->addr[0], &sk2->addr[1], sk2->port[0], sk2->port[1]);
} else
sk2 = pf_state_key_ref(sk1);
if (pd->dir == PF_IN) {
*skw = sk1;
*sks = sk2;
} else {
*sks = sk1;
*skw = sk2;
}
if (pf_status.debug >= LOG_DEBUG) {
log(LOG_DEBUG, "pf: key setup: ");
pf_print_state_parts(NULL, *skw, *sks);
addlog("\n");
}
return (0);
}
/*
* pf_state_insert() does the following:
* - links the pf_state up with pf_state_key(s).
* - inserts the pf_state_keys into pf_state_tree.
* - inserts the pf_state into the into pf_state_tree_id.
* - tells pfsync about the state.
*
* pf_state_insert() owns the references to the pf_state_key structs
* it is given. on failure to insert, these references are released.
* on success, the caller owns a pf_state reference that allows it
* to access the state keys.
*/
int
pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skwp,
struct pf_state_key **sksp, struct pf_state *st)
{
struct pf_state_key *skw = *skwp;
struct pf_state_key *sks = *sksp;
int same = (skw == sks);
PF_ASSERT_LOCKED();
st->kif = kif;
PF_STATE_ENTER_WRITE();
skw = pf_state_key_attach(skw, st, PF_SK_WIRE);
if (skw == NULL) {
pf_state_key_unref(sks);
PF_STATE_EXIT_WRITE();
return (-1);
}
if (same) {
/* pf_state_key_attach might have swapped skw */
pf_state_key_unref(sks);
st->key[PF_SK_STACK] = sks = pf_state_key_ref(skw);
} else if (pf_state_key_attach(sks, st, PF_SK_STACK) == NULL) {
pf_state_key_detach(st, PF_SK_WIRE);
PF_STATE_EXIT_WRITE();
return (-1);
}
if (st->id == 0 && st->creatorid == 0) {
st->id = htobe64(pf_status.stateid++);
st->creatorid = pf_status.hostid;
}
if (RBT_INSERT(pf_state_tree_id, &tree_id, st) != NULL) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE, "pf: state insert failed: "
"id: %016llx creatorid: %08x",
betoh64(st->id), ntohl(st->creatorid));
addlog("\n");
}
pf_detach_state(st);
PF_STATE_EXIT_WRITE();
return (-1);
}
pf_state_list_insert(&pf_state_list, st);
pf_status.fcounters[FCNT_STATE_INSERT]++;
pf_status.states++;
pfi_kif_ref(kif, PFI_KIF_REF_STATE);
PF_STATE_EXIT_WRITE();
#if NPFSYNC > 0
pfsync_insert_state(st);
#endif /* NPFSYNC > 0 */
*skwp = skw;
*sksp = sks;
return (0);
}
struct pf_state *
pf_find_state_byid(struct pf_state_cmp *key)
{
pf_status.fcounters[FCNT_STATE_SEARCH]++;
return (RBT_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key));
}
int
pf_compare_state_keys(struct pf_state_key *a, struct pf_state_key *b,
struct pfi_kif *kif, u_int dir)
{
/* a (from hdr) and b (new) must be exact opposites of each other */
if (a->af == b->af && a->proto == b->proto &&
PF_AEQ(&a->addr[0], &b->addr[1], a->af) &&
PF_AEQ(&a->addr[1], &b->addr[0], a->af) &&
a->port[0] == b->port[1] &&
a->port[1] == b->port[0] && a->rdomain == b->rdomain)
return (0);
else {
/* mismatch. must not happen. */
if (pf_status.debug >= LOG_ERR) {
log(LOG_ERR,
"pf: state key linking mismatch! dir=%s, "
"if=%s, stored af=%u, a0: ",
dir == PF_OUT ? "OUT" : "IN",
kif->pfik_name, a->af);
pf_print_host(&a->addr[0], a->port[0], a->af);
addlog(", a1: ");
pf_print_host(&a->addr[1], a->port[1], a->af);
addlog(", proto=%u", a->proto);
addlog(", found af=%u, a0: ", b->af);
pf_print_host(&b->addr[0], b->port[0], b->af);
addlog(", a1: ");
pf_print_host(&b->addr[1], b->port[1], b->af);
addlog(", proto=%u", b->proto);
addlog("\n");
}
return (-1);
}
}
int
pf_find_state(struct pf_pdesc *pd, struct pf_state_key_cmp *key,
struct pf_state **stp)
{
struct pf_state_key *sk, *pkt_sk;
struct pf_state_item *si;
struct pf_state *st = NULL;
pf_status.fcounters[FCNT_STATE_SEARCH]++;
if (pf_status.debug >= LOG_DEBUG) {
log(LOG_DEBUG, "pf: key search, %s on %s: ",
pd->dir == PF_OUT ? "out" : "in", pd->kif->pfik_name);
pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL);
addlog("\n");
}
pkt_sk = NULL;
sk = NULL;
if (pd->dir == PF_OUT) {
/* first if block deals with outbound forwarded packet */
pkt_sk = pd->m->m_pkthdr.pf.statekey;
if (!pf_state_key_isvalid(pkt_sk)) {
pf_mbuf_unlink_state_key(pd->m);
pkt_sk = NULL;
}
if (pkt_sk && pf_state_key_isvalid(pkt_sk->sk_reverse))
sk = pkt_sk->sk_reverse;
if (pkt_sk == NULL) {
struct inpcb *inp = pd->m->m_pkthdr.pf.inp;
/* here we deal with local outbound packet */
if (inp != NULL) {
struct pf_state_key *inp_sk;
mtx_enter(&pf_inp_mtx);
inp_sk = inp->inp_pf_sk;
if (pf_state_key_isvalid(inp_sk)) {
sk = inp_sk;
mtx_leave(&pf_inp_mtx);
} else if (inp_sk != NULL) {
KASSERT(inp_sk->sk_inp == inp);
inp_sk->sk_inp = NULL;
inp->inp_pf_sk = NULL;
mtx_leave(&pf_inp_mtx);
pf_state_key_unref(inp_sk);
in_pcbunref(inp);
} else
mtx_leave(&pf_inp_mtx);
}
}
}
if (sk == NULL) {
if ((sk = RBT_FIND(pf_state_tree, &pf_statetbl,
(struct pf_state_key *)key)) == NULL)
return (PF_DROP);
if (pd->dir == PF_OUT && pkt_sk &&
pf_compare_state_keys(pkt_sk, sk, pd->kif, pd->dir) == 0)
pf_state_key_link_reverse(sk, pkt_sk);
else if (pd->dir == PF_OUT)
pf_state_key_link_inpcb(sk, pd->m->m_pkthdr.pf.inp);
}
/* remove firewall data from outbound packet */
if (pd->dir == PF_OUT)
pf_pkt_addr_changed(pd->m);
/* list is sorted, if-bound states before floating ones */
TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
struct pf_state *sist = si->si_st;
if (sist->timeout != PFTM_PURGE &&
(sist->kif == pfi_all || sist->kif == pd->kif) &&
((sist->key[PF_SK_WIRE]->af == sist->key[PF_SK_STACK]->af &&
sk == (pd->dir == PF_IN ? sist->key[PF_SK_WIRE] :
sist->key[PF_SK_STACK])) ||
(sist->key[PF_SK_WIRE]->af != sist->key[PF_SK_STACK]->af
&& pd->dir == PF_IN && (sk == sist->key[PF_SK_STACK] ||
sk == sist->key[PF_SK_WIRE])))) {
st = sist;
break;
}
}
if (st == NULL)
return (PF_DROP);
if (ISSET(st->state_flags, PFSTATE_INP_UNLINKED))
return (PF_DROP);
if (st->rule.ptr->pktrate.limit && pd->dir == st->direction) {
pf_add_threshold(&st->rule.ptr->pktrate);
if (pf_check_threshold(&st->rule.ptr->pktrate))
return (PF_DROP);
}
*stp = st;
return (PF_MATCH);
}
struct pf_state *
pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more)
{
struct pf_state_key *sk;
struct pf_state_item *si, *ret = NULL;
pf_status.fcounters[FCNT_STATE_SEARCH]++;
sk = RBT_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key);
if (sk != NULL) {
TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
struct pf_state *sist = si->si_st;
if (dir == PF_INOUT ||
(sk == (dir == PF_IN ? sist->key[PF_SK_WIRE] :
sist->key[PF_SK_STACK]))) {
if (more == NULL)
return (sist);
if (ret)
(*more)++;
else
ret = si;
}
}
}
return (ret ? ret->si_st : NULL);
}
void
pf_state_peer_hton(const struct pf_state_peer *s, struct pfsync_state_peer *d)
{
d->seqlo = htonl(s->seqlo);
d->seqhi = htonl(s->seqhi);
d->seqdiff = htonl(s->seqdiff);
d->max_win = htons(s->max_win);
d->mss = htons(s->mss);
d->state = s->state;
d->wscale = s->wscale;
if (s->scrub) {
d->scrub.pfss_flags =
htons(s->scrub->pfss_flags & PFSS_TIMESTAMP);
d->scrub.pfss_ttl = (s)->scrub->pfss_ttl;
d->scrub.pfss_ts_mod = htonl((s)->scrub->pfss_ts_mod);
d->scrub.scrub_flag = PFSYNC_SCRUB_FLAG_VALID;
}
}
void
pf_state_peer_ntoh(const struct pfsync_state_peer *s, struct pf_state_peer *d)
{
d->seqlo = ntohl(s->seqlo);
d->seqhi = ntohl(s->seqhi);
d->seqdiff = ntohl(s->seqdiff);
d->max_win = ntohs(s->max_win);
d->mss = ntohs(s->mss);
d->state = s->state;
d->wscale = s->wscale;
if (s->scrub.scrub_flag == PFSYNC_SCRUB_FLAG_VALID &&
d->scrub != NULL) {
d->scrub->pfss_flags =
ntohs(s->scrub.pfss_flags) & PFSS_TIMESTAMP;
d->scrub->pfss_ttl = s->scrub.pfss_ttl;
d->scrub->pfss_ts_mod = ntohl(s->scrub.pfss_ts_mod);
}
}
void
pf_state_export(struct pfsync_state *sp, struct pf_state *st)
{
int32_t expire;
memset(sp, 0, sizeof(struct pfsync_state));
/* copy from state key */
sp->key[PF_SK_WIRE].addr[0] = st->key[PF_SK_WIRE]->addr[0];
sp->key[PF_SK_WIRE].addr[1] = st->key[PF_SK_WIRE]->addr[1];
sp->key[PF_SK_WIRE].port[0] = st->key[PF_SK_WIRE]->port[0];
sp->key[PF_SK_WIRE].port[1] = st->key[PF_SK_WIRE]->port[1];
sp->key[PF_SK_WIRE].rdomain = htons(st->key[PF_SK_WIRE]->rdomain);
sp->key[PF_SK_WIRE].af = st->key[PF_SK_WIRE]->af;
sp->key[PF_SK_STACK].addr[0] = st->key[PF_SK_STACK]->addr[0];
sp->key[PF_SK_STACK].addr[1] = st->key[PF_SK_STACK]->addr[1];
sp->key[PF_SK_STACK].port[0] = st->key[PF_SK_STACK]->port[0];
sp->key[PF_SK_STACK].port[1] = st->key[PF_SK_STACK]->port[1];
sp->key[PF_SK_STACK].rdomain = htons(st->key[PF_SK_STACK]->rdomain);
sp->key[PF_SK_STACK].af = st->key[PF_SK_STACK]->af;
sp->rtableid[PF_SK_WIRE] = htonl(st->rtableid[PF_SK_WIRE]);
sp->rtableid[PF_SK_STACK] = htonl(st->rtableid[PF_SK_STACK]);
sp->proto = st->key[PF_SK_WIRE]->proto;
sp->af = st->key[PF_SK_WIRE]->af;
/* copy from state */
strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname));
sp->rt = st->rt;
sp->rt_addr = st->rt_addr;
sp->creation = htonl(getuptime() - st->creation);
expire = pf_state_expires(st, st->timeout);
if (expire <= getuptime())
sp->expire = htonl(0);
else
sp->expire = htonl(expire - getuptime());
sp->direction = st->direction;
#if NPFLOG > 0
sp->log = st->log;
#endif /* NPFLOG > 0 */
sp->timeout = st->timeout;
sp->state_flags = htons(st->state_flags);
if (READ_ONCE(st->sync_defer) != NULL)
sp->state_flags |= htons(PFSTATE_ACK);
if (!SLIST_EMPTY(&st->src_nodes))
sp->sync_flags |= PFSYNC_FLAG_SRCNODE;
sp->id = st->id;
sp->creatorid = st->creatorid;
pf_state_peer_hton(&st->src, &sp->src);
pf_state_peer_hton(&st->dst, &sp->dst);
if (st->rule.ptr == NULL)
sp->rule = htonl(-1);
else
sp->rule = htonl(st->rule.ptr->nr);
if (st->anchor.ptr == NULL)
sp->anchor = htonl(-1);
else
sp->anchor = htonl(st->anchor.ptr->nr);
sp->nat_rule = htonl(-1); /* left for compat, nat_rule is gone */
pf_state_counter_hton(st->packets[0], sp->packets[0]);
pf_state_counter_hton(st->packets[1], sp->packets[1]);
pf_state_counter_hton(st->bytes[0], sp->bytes[0]);
pf_state_counter_hton(st->bytes[1], sp->bytes[1]);
sp->max_mss = htons(st->max_mss);
sp->min_ttl = st->min_ttl;
sp->set_tos = st->set_tos;
sp->set_prio[0] = st->set_prio[0];
sp->set_prio[1] = st->set_prio[1];
}
int
pf_state_alloc_scrub_memory(const struct pfsync_state_peer *s,
struct pf_state_peer *d)
{
if (s->scrub.scrub_flag && d->scrub == NULL)
return (pf_normalize_tcp_alloc(d));
return (0);
}
#if NPFSYNC > 0
int
pf_state_import(const struct pfsync_state *sp, int flags)
{
struct pf_state *st = NULL;
struct pf_state_key *skw = NULL, *sks = NULL;
struct pf_rule *r = NULL;
struct pfi_kif *kif;
int pool_flags;
int error = ENOMEM;
int n = 0;
PF_ASSERT_LOCKED();
if (sp->creatorid == 0) {
DPFPRINTF(LOG_NOTICE, "%s: invalid creator id: %08x", __func__,
ntohl(sp->creatorid));
return (EINVAL);
}
if ((kif = pfi_kif_get(sp->ifname, NULL)) == NULL) {
DPFPRINTF(LOG_NOTICE, "%s: unknown interface: %s", __func__,
sp->ifname);
if (flags & PFSYNC_SI_IOCTL)
return (EINVAL);
return (0); /* skip this state */
}
if (sp->af == 0)
return (0); /* skip this state */
/*
* If the ruleset checksums match or the state is coming from the ioctl,
* it's safe to associate the state with the rule of that number.
*/
if (sp->rule != htonl(-1) && sp->anchor == htonl(-1) &&
(flags & (PFSYNC_SI_IOCTL | PFSYNC_SI_CKSUM)) &&
ntohl(sp->rule) < pf_main_ruleset.rules.active.rcount) {
TAILQ_FOREACH(r, pf_main_ruleset.rules.active.ptr, entries)
if (ntohl(sp->rule) == n++)
break;
} else
r = &pf_default_rule;
if ((r->max_states && r->states_cur >= r->max_states))
goto cleanup;
if (flags & PFSYNC_SI_IOCTL)
pool_flags = PR_WAITOK | PR_LIMITFAIL | PR_ZERO;
else
pool_flags = PR_NOWAIT | PR_LIMITFAIL | PR_ZERO;
if ((st = pool_get(&pf_state_pl, pool_flags)) == NULL)
goto cleanup;
if ((skw = pf_alloc_state_key(pool_flags)) == NULL)
goto cleanup;
if ((sp->key[PF_SK_WIRE].af &&
(sp->key[PF_SK_WIRE].af != sp->key[PF_SK_STACK].af)) ||
PF_ANEQ(&sp->key[PF_SK_WIRE].addr[0],
&sp->key[PF_SK_STACK].addr[0], sp->af) ||
PF_ANEQ(&sp->key[PF_SK_WIRE].addr[1],
&sp->key[PF_SK_STACK].addr[1], sp->af) ||
sp->key[PF_SK_WIRE].port[0] != sp->key[PF_SK_STACK].port[0] ||
sp->key[PF_SK_WIRE].port[1] != sp->key[PF_SK_STACK].port[1] ||
sp->key[PF_SK_WIRE].rdomain != sp->key[PF_SK_STACK].rdomain) {
if ((sks = pf_alloc_state_key(pool_flags)) == NULL)
goto cleanup;
} else
sks = pf_state_key_ref(skw);
/* allocate memory for scrub info */
if (pf_state_alloc_scrub_memory(&sp->src, &st->src) ||
pf_state_alloc_scrub_memory(&sp->dst, &st->dst))
goto cleanup;
/* copy to state key(s) */
skw->addr[0] = sp->key[PF_SK_WIRE].addr[0];
skw->addr[1] = sp->key[PF_SK_WIRE].addr[1];
skw->port[0] = sp->key[PF_SK_WIRE].port[0];
skw->port[1] = sp->key[PF_SK_WIRE].port[1];
skw->rdomain = ntohs(sp->key[PF_SK_WIRE].rdomain);
skw->proto = sp->proto;
if (!(skw->af = sp->key[PF_SK_WIRE].af))
skw->af = sp->af;
skw->hash = pf_pkt_hash(skw->af, skw->proto,
&skw->addr[0], &skw->addr[1], skw->port[0], skw->port[1]);
if (sks != skw) {
sks->addr[0] = sp->key[PF_SK_STACK].addr[0];
sks->addr[1] = sp->key[PF_SK_STACK].addr[1];
sks->port[0] = sp->key[PF_SK_STACK].port[0];
sks->port[1] = sp->key[PF_SK_STACK].port[1];
sks->rdomain = ntohs(sp->key[PF_SK_STACK].rdomain);
if (!(sks->af = sp->key[PF_SK_STACK].af))
sks->af = sp->af;
if (sks->af != skw->af) {
switch (sp->proto) {
case IPPROTO_ICMP:
sks->proto = IPPROTO_ICMPV6;
break;
case IPPROTO_ICMPV6:
sks->proto = IPPROTO_ICMP;
break;
default:
sks->proto = sp->proto;
}
} else
sks->proto = sp->proto;
if (((sks->af != AF_INET) && (sks->af != AF_INET6)) ||
((skw->af != AF_INET) && (skw->af != AF_INET6))) {
error = EINVAL;
goto cleanup;
}
sks->hash = pf_pkt_hash(sks->af, sks->proto,
&sks->addr[0], &sks->addr[1], sks->port[0], sks->port[1]);
} else if ((sks->af != AF_INET) && (sks->af != AF_INET6)) {
error = EINVAL;
goto cleanup;
}
st->rtableid[PF_SK_WIRE] = ntohl(sp->rtableid[PF_SK_WIRE]);
st->rtableid[PF_SK_STACK] = ntohl(sp->rtableid[PF_SK_STACK]);
/* copy to state */
st->rt_addr = sp->rt_addr;
st->rt = sp->rt;
st->creation = getuptime() - ntohl(sp->creation);
st->expire = getuptime();
if (ntohl(sp->expire)) {
u_int32_t timeout;
timeout = r->timeout[sp->timeout];
if (!timeout)
timeout = pf_default_rule.timeout[sp->timeout];
/* sp->expire may have been adaptively scaled by export. */
st->expire -= timeout - ntohl(sp->expire);
}
st->direction = sp->direction;
st->log = sp->log;
st->timeout = sp->timeout;
st->state_flags = ntohs(sp->state_flags);
st->max_mss = ntohs(sp->max_mss);
st->min_ttl = sp->min_ttl;
st->set_tos = sp->set_tos;
st->set_prio[0] = sp->set_prio[0];
st->set_prio[1] = sp->set_prio[1];
st->id = sp->id;
st->creatorid = sp->creatorid;
pf_state_peer_ntoh(&sp->src, &st->src);
pf_state_peer_ntoh(&sp->dst, &st->dst);
st->rule.ptr = r;
st->anchor.ptr = NULL;
PF_REF_INIT(st->refcnt);
mtx_init(&st->mtx, IPL_NET);
/* XXX when we have anchors, use STATE_INC_COUNTERS */
r->states_cur++;
r->states_tot++;
st->sync_state = PFSYNC_S_NONE;
st->pfsync_time = getuptime();
#if NPFSYNC > 0
pfsync_init_state(st, skw, sks, flags);
#endif
if (pf_state_insert(kif, &skw, &sks, st) != 0) {
/* XXX when we have anchors, use STATE_DEC_COUNTERS */
r->states_cur--;
error = EEXIST;
goto cleanup_state;
}
return (0);
cleanup:
if (skw != NULL)
pf_state_key_unref(skw);
if (sks != NULL)
pf_state_key_unref(sks);
cleanup_state: /* pf_state_insert frees the state keys */
if (st) {
if (st->dst.scrub)
pool_put(&pf_state_scrub_pl, st->dst.scrub);
if (st->src.scrub)
pool_put(&pf_state_scrub_pl, st->src.scrub);
pool_put(&pf_state_pl, st);
}
return (error);
}
#endif /* NPFSYNC > 0 */
/* END state table stuff */
void pf_purge_states(void *);
struct task pf_purge_states_task =
TASK_INITIALIZER(pf_purge_states, NULL);
void pf_purge_states_tick(void *);
struct timeout pf_purge_states_to =
TIMEOUT_INITIALIZER(pf_purge_states_tick, NULL);
unsigned int pf_purge_expired_states(unsigned int, unsigned int);
/*
* how many states to scan this interval.
*
* this is set when the timeout fires, and reduced by the task. the
* task will reschedule itself until the limit is reduced to zero,
* and then it adds the timeout again.
*/
unsigned int pf_purge_states_limit;
/*
* limit how many states are processed with locks held per run of
* the state purge task.
*/
unsigned int pf_purge_states_collect = 64;
void
pf_purge_states_tick(void *null)
{
unsigned int limit = pf_status.states;
unsigned int interval = pf_default_rule.timeout[PFTM_INTERVAL];
if (limit == 0) {
timeout_add_sec(&pf_purge_states_to, 1);
return;
}
/*
* process a fraction of the state table every second
*/
if (interval > 1)
limit /= interval;
pf_purge_states_limit = limit;
task_add(systqmp, &pf_purge_states_task);
}
void
pf_purge_states(void *null)
{
unsigned int limit;
unsigned int scanned;
limit = pf_purge_states_limit;
if (limit < pf_purge_states_collect)
limit = pf_purge_states_collect;
scanned = pf_purge_expired_states(limit, pf_purge_states_collect);
if (scanned >= pf_purge_states_limit) {
/* we've run out of states to scan this "interval" */
timeout_add_sec(&pf_purge_states_to, 1);
return;
}
pf_purge_states_limit -= scanned;
task_add(systqmp, &pf_purge_states_task);
}
void pf_purge_tick(void *);
struct timeout pf_purge_to =
TIMEOUT_INITIALIZER(pf_purge_tick, NULL);
void pf_purge(void *);
struct task pf_purge_task =
TASK_INITIALIZER(pf_purge, NULL);
void
pf_purge_tick(void *null)
{
task_add(systqmp, &pf_purge_task);
}
void
pf_purge(void *null)
{
unsigned int interval = max(1, pf_default_rule.timeout[PFTM_INTERVAL]);
PF_LOCK();
pf_purge_expired_src_nodes();
PF_UNLOCK();
/*
* Fragments don't require PF_LOCK(), they use their own lock.
*/
pf_purge_expired_fragments();
/* interpret the interval as idle time between runs */
timeout_add_sec(&pf_purge_to, interval);
}
int32_t
pf_state_expires(const struct pf_state *st, uint8_t stimeout)
{
u_int32_t timeout;
u_int32_t start;
u_int32_t end;
u_int32_t states;
/*
* pf_state_expires is used by the state purge task to
* decide if a state is a candidate for cleanup, and by the
* pfsync state export code to populate an expiry time.
*
* this function may be called by the state purge task while
* the state is being modified. avoid inconsistent reads of
* state->timeout by having the caller do the read (and any
* checks it needs to do on the same variable) and then pass
* their view of the timeout in here for this function to use.
* the only consequence of using a stale timeout value is
* that the state won't be a candidate for purging until the
* next pass of the purge task.
*/
/* handle all PFTM_* >= PFTM_MAX here */
if (stimeout >= PFTM_MAX)
return (0);
KASSERT(stimeout < PFTM_MAX);
timeout = st->rule.ptr->timeout[stimeout];
if (!timeout)
timeout = pf_default_rule.timeout[stimeout];
start = st->rule.ptr->timeout[PFTM_ADAPTIVE_START];
if (start) {
end = st->rule.ptr->timeout[PFTM_ADAPTIVE_END];
states = st->rule.ptr->states_cur;
} else {
start = pf_default_rule.timeout[PFTM_ADAPTIVE_START];
end = pf_default_rule.timeout[PFTM_ADAPTIVE_END];
states = pf_status.states;
}
if (end && states > start && start < end) {
if (states >= end)
return (0);
timeout = (u_int64_t)timeout * (end - states) / (end - start);
}
return (st->expire + timeout);
}
void
pf_purge_expired_src_nodes(void)
{
struct pf_src_node *cur, *next;
PF_ASSERT_LOCKED();
RB_FOREACH_SAFE(cur, pf_src_tree, &tree_src_tracking, next) {
if (cur->states == 0 && cur->expire <= getuptime()) {
pf_remove_src_node(cur);
}
}
}
void
pf_src_tree_remove_state(struct pf_state *st)
{
u_int32_t timeout;
struct pf_sn_item *sni;
while ((sni = SLIST_FIRST(&st->src_nodes)) != NULL) {
SLIST_REMOVE_HEAD(&st->src_nodes, next);
if (st->src.tcp_est)
--sni->sn->conn;
if (--sni->sn->states == 0) {
timeout = st->rule.ptr->timeout[PFTM_SRC_NODE];
if (!timeout)
timeout =
pf_default_rule.timeout[PFTM_SRC_NODE];
sni->sn->expire = getuptime() + timeout;
}
pool_put(&pf_sn_item_pl, sni);
}
}
void
pf_remove_state(struct pf_state *st)
{
PF_ASSERT_LOCKED();
mtx_enter(&st->mtx);
if (st->timeout == PFTM_UNLINKED) {
mtx_leave(&st->mtx);
return;
}
st->timeout = PFTM_UNLINKED;
mtx_leave(&st->mtx);
/* handle load balancing related tasks */
pf_postprocess_addr(st);
if (st->src.state == PF_TCPS_PROXY_DST) {
pf_send_tcp(st->rule.ptr, st->key[PF_SK_WIRE]->af,
&st->key[PF_SK_WIRE]->addr[1],
&st->key[PF_SK_WIRE]->addr[0],
st->key[PF_SK_WIRE]->port[1],
st->key[PF_SK_WIRE]->port[0],
st->src.seqhi, st->src.seqlo + 1,
TH_RST|TH_ACK, 0, 0, 0, 1, st->tag,
st->key[PF_SK_WIRE]->rdomain);
}
if (st->key[PF_SK_STACK]->proto == IPPROTO_TCP)
pf_set_protostate(st, PF_PEER_BOTH, TCPS_CLOSED);
RBT_REMOVE(pf_state_tree_id, &tree_id, st);
#if NPFLOW > 0
if (st->state_flags & PFSTATE_PFLOW)
export_pflow(st);
#endif /* NPFLOW > 0 */
#if NPFSYNC > 0
pfsync_delete_state(st);
#endif /* NPFSYNC > 0 */
pf_src_tree_remove_state(st);
pf_detach_state(st);
}
void
pf_remove_divert_state(struct inpcb *inp)
{
struct pf_state_key *sk;
struct pf_state_item *si;
PF_ASSERT_UNLOCKED();
if (READ_ONCE(inp->inp_pf_sk) == NULL)
return;
mtx_enter(&pf_inp_mtx);
sk = pf_state_key_ref(inp->inp_pf_sk);
mtx_leave(&pf_inp_mtx);
if (sk == NULL)
return;
PF_LOCK();
PF_STATE_ENTER_WRITE();
TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
struct pf_state *sist = si->si_st;
if (sk == sist->key[PF_SK_STACK] && sist->rule.ptr &&
(sist->rule.ptr->divert.type == PF_DIVERT_TO ||
sist->rule.ptr->divert.type == PF_DIVERT_REPLY)) {
if (sist->key[PF_SK_STACK]->proto == IPPROTO_TCP &&
sist->key[PF_SK_WIRE] != sist->key[PF_SK_STACK]) {
/*
* If the local address is translated, keep
* the state for "tcp.closed" seconds to
* prevent its source port from being reused.
*/
if (sist->src.state < TCPS_FIN_WAIT_2 ||
sist->dst.state < TCPS_FIN_WAIT_2) {
pf_set_protostate(sist, PF_PEER_BOTH,
TCPS_TIME_WAIT);
pf_update_state_timeout(sist,
PFTM_TCP_CLOSED);
sist->expire = getuptime();
}
sist->state_flags |= PFSTATE_INP_UNLINKED;
} else
pf_remove_state(sist);
break;
}
}
PF_STATE_EXIT_WRITE();
PF_UNLOCK();
pf_state_key_unref(sk);
}
void
pf_free_state(struct pf_state *st)
{
struct pf_rule_item *ri;
PF_ASSERT_LOCKED();
#if NPFSYNC > 0
if (pfsync_state_in_use(st))
return;
#endif /* NPFSYNC > 0 */
KASSERT(st->timeout == PFTM_UNLINKED);
if (--st->rule.ptr->states_cur == 0 &&
st->rule.ptr->src_nodes == 0)
pf_rm_rule(NULL, st->rule.ptr);
if (st->anchor.ptr != NULL)
if (--st->anchor.ptr->states_cur == 0)
pf_rm_rule(NULL, st->anchor.ptr);
while ((ri = SLIST_FIRST(&st->match_rules))) {
SLIST_REMOVE_HEAD(&st->match_rules, entry);
if (--ri->r->states_cur == 0 &&
ri->r->src_nodes == 0)
pf_rm_rule(NULL, ri->r);
pool_put(&pf_rule_item_pl, ri);
}
pf_normalize_tcp_cleanup(st);
pfi_kif_unref(st->kif, PFI_KIF_REF_STATE);
pf_state_list_remove(&pf_state_list, st);
if (st->tag)
pf_tag_unref(st->tag);
pf_state_unref(st);
pf_status.fcounters[FCNT_STATE_REMOVALS]++;
pf_status.states--;
}
unsigned int
pf_purge_expired_states(const unsigned int limit, const unsigned int collect)
{
/*
* this task/thread/context/whatever is the only thing that
* removes states from the pf_state_list, so the cur reference
* it holds between calls is guaranteed to still be in the
* list.
*/
static struct pf_state *cur = NULL;
struct pf_state *head, *tail;
struct pf_state *st;
SLIST_HEAD(pf_state_gcl, pf_state) gcl = SLIST_HEAD_INITIALIZER(gcl);
time_t now;
unsigned int scanned;
unsigned int collected = 0;
PF_ASSERT_UNLOCKED();
rw_enter_read(&pf_state_list.pfs_rwl);
mtx_enter(&pf_state_list.pfs_mtx);
head = TAILQ_FIRST(&pf_state_list.pfs_list);
tail = TAILQ_LAST(&pf_state_list.pfs_list, pf_state_queue);
mtx_leave(&pf_state_list.pfs_mtx);
if (head == NULL) {
/* the list is empty */
rw_exit_read(&pf_state_list.pfs_rwl);
return (limit);
}
/* (re)start at the front of the list */
if (cur == NULL)
cur = head;
now = getuptime();
for (scanned = 0; scanned < limit; scanned++) {
uint8_t stimeout = cur->timeout;
unsigned int limited = 0;
if ((stimeout == PFTM_UNLINKED) ||
(pf_state_expires(cur, stimeout) <= now)) {
st = pf_state_ref(cur);
SLIST_INSERT_HEAD(&gcl, st, gc_list);
if (++collected >= collect)
limited = 1;
}
/* don't iterate past the end of our view of the list */
if (cur == tail) {
cur = NULL;
break;
}
cur = TAILQ_NEXT(cur, entry_list);
/* don't spend too much time here. */
if (ISSET(READ_ONCE(curcpu()->ci_schedstate.spc_schedflags),
SPCF_SHOULDYIELD) || limited)
break;
}
rw_exit_read(&pf_state_list.pfs_rwl);
if (SLIST_EMPTY(&gcl))
return (scanned);
rw_enter_write(&pf_state_list.pfs_rwl);
PF_LOCK();
PF_STATE_ENTER_WRITE();
SLIST_FOREACH(st, &gcl, gc_list) {
if (st->timeout != PFTM_UNLINKED)
pf_remove_state(st);
pf_free_state(st);
}
PF_STATE_EXIT_WRITE();
PF_UNLOCK();
rw_exit_write(&pf_state_list.pfs_rwl);
while ((st = SLIST_FIRST(&gcl)) != NULL) {
SLIST_REMOVE_HEAD(&gcl, gc_list);
pf_state_unref(st);
}
return (scanned);
}
int
pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw, int wait)
{
if (aw->type != PF_ADDR_TABLE)
return (0);
if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, wait)) == NULL)
return (1);
return (0);
}
void
pf_tbladdr_remove(struct pf_addr_wrap *aw)
{
if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL)
return;
pfr_detach_table(aw->p.tbl);
aw->p.tbl = NULL;
}
void
pf_tbladdr_copyout(struct pf_addr_wrap *aw)
{
struct pfr_ktable *kt = aw->p.tbl;
if (aw->type != PF_ADDR_TABLE || kt == NULL)
return;
if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL)
kt = kt->pfrkt_root;
aw->p.tbl = NULL;
aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ?
kt->pfrkt_cnt : -1;
}
void
pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af)
{
switch (af) {
case AF_INET: {
u_int32_t a = ntohl(addr->addr32[0]);
addlog("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255,
(a>>8)&255, a&255);
if (p) {
p = ntohs(p);
addlog(":%u", p);
}
break;
}
#ifdef INET6
case AF_INET6: {
u_int16_t b;
u_int8_t i, curstart, curend, maxstart, maxend;
curstart = curend = maxstart = maxend = 255;
for (i = 0; i < 8; i++) {
if (!addr->addr16[i]) {
if (curstart == 255)
curstart = i;
curend = i;
} else {
if ((curend - curstart) >
(maxend - maxstart)) {
maxstart = curstart;
maxend = curend;
}
curstart = curend = 255;
}
}
if ((curend - curstart) >
(maxend - maxstart)) {
maxstart = curstart;
maxend = curend;
}
for (i = 0; i < 8; i++) {
if (i >= maxstart && i <= maxend) {
if (i == 0)
addlog(":");
if (i == maxend)
addlog(":");
} else {
b = ntohs(addr->addr16[i]);
addlog("%x", b);
if (i < 7)
addlog(":");
}
}
if (p) {
p = ntohs(p);
addlog("[%u]", p);
}
break;
}
#endif /* INET6 */
}
}
void
pf_print_state(struct pf_state *st)
{
pf_print_state_parts(st, NULL, NULL);
}
void
pf_print_state_parts(struct pf_state *st,
struct pf_state_key *skwp, struct pf_state_key *sksp)
{
struct pf_state_key *skw, *sks;
u_int8_t proto, dir;
/* Do our best to fill these, but they're skipped if NULL */
skw = skwp ? skwp : (st ? st->key[PF_SK_WIRE] : NULL);
sks = sksp ? sksp : (st ? st->key[PF_SK_STACK] : NULL);
proto = skw ? skw->proto : (sks ? sks->proto : 0);
dir = st ? st->direction : 0;
switch (proto) {
case IPPROTO_IPV4:
addlog("IPv4");
break;
case IPPROTO_IPV6:
addlog("IPv6");
break;
case IPPROTO_TCP:
addlog("TCP");
break;
case IPPROTO_UDP:
addlog("UDP");
break;
case IPPROTO_ICMP:
addlog("ICMP");
break;
case IPPROTO_ICMPV6:
addlog("ICMPv6");
break;
default:
addlog("%u", proto);
break;
}
switch (dir) {
case PF_IN:
addlog(" in");
break;
case PF_OUT:
addlog(" out");
break;
}
if (skw) {
addlog(" wire: (%d) ", skw->rdomain);
pf_print_host(&skw->addr[0], skw->port[0], skw->af);
addlog(" ");
pf_print_host(&skw->addr[1], skw->port[1], skw->af);
}
if (sks) {
addlog(" stack: (%d) ", sks->rdomain);
if (sks != skw) {
pf_print_host(&sks->addr[0], sks->port[0], sks->af);
addlog(" ");
pf_print_host(&sks->addr[1], sks->port[1], sks->af);
} else
addlog("-");
}
if (st) {
if (proto == IPPROTO_TCP) {
addlog(" [lo=%u high=%u win=%u modulator=%u",
st->src.seqlo, st->src.seqhi,
st->src.max_win, st->src.seqdiff);
if (st->src.wscale && st->dst.wscale)
addlog(" wscale=%u",
st->src.wscale & PF_WSCALE_MASK);
addlog("]");
addlog(" [lo=%u high=%u win=%u modulator=%u",
st->dst.seqlo, st->dst.seqhi,
st->dst.max_win, st->dst.seqdiff);
if (st->src.wscale && st->dst.wscale)
addlog(" wscale=%u",
st->dst.wscale & PF_WSCALE_MASK);
addlog("]");
}
addlog(" %u:%u", st->src.state, st->dst.state);
if (st->rule.ptr)
addlog(" @%d", st->rule.ptr->nr);
}
}
void
pf_print_flags(u_int8_t f)
{
if (f)
addlog(" ");
if (f & TH_FIN)
addlog("F");
if (f & TH_SYN)
addlog("S");
if (f & TH_RST)
addlog("R");
if (f & TH_PUSH)
addlog("P");
if (f & TH_ACK)
addlog("A");
if (f & TH_URG)
addlog("U");
if (f & TH_ECE)
addlog("E");
if (f & TH_CWR)
addlog("W");
}
#define PF_SET_SKIP_STEPS(i) \
do { \
while (head[i] != cur) { \
head[i]->skip[i].ptr = cur; \
head[i] = TAILQ_NEXT(head[i], entries); \
} \
} while (0)
void
pf_calc_skip_steps(struct pf_rulequeue *rules)
{
struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT];
int i;
cur = TAILQ_FIRST(rules);
prev = cur;
for (i = 0; i < PF_SKIP_COUNT; ++i)
head[i] = cur;
while (cur != NULL) {
if (cur->kif != prev->kif || cur->ifnot != prev->ifnot)
PF_SET_SKIP_STEPS(PF_SKIP_IFP);
if (cur->direction != prev->direction)
PF_SET_SKIP_STEPS(PF_SKIP_DIR);
if (cur->onrdomain != prev->onrdomain ||
cur->ifnot != prev->ifnot)
PF_SET_SKIP_STEPS(PF_SKIP_RDOM);
if (cur->af != prev->af)
PF_SET_SKIP_STEPS(PF_SKIP_AF);
if (cur->proto != prev->proto)
PF_SET_SKIP_STEPS(PF_SKIP_PROTO);
if (cur->src.neg != prev->src.neg ||
pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr))
PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR);
if (cur->dst.neg != prev->dst.neg ||
pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr))
PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR);
if (cur->src.port[0] != prev->src.port[0] ||
cur->src.port[1] != prev->src.port[1] ||
cur->src.port_op != prev->src.port_op)
PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT);
if (cur->dst.port[0] != prev->dst.port[0] ||
cur->dst.port[1] != prev->dst.port[1] ||
cur->dst.port_op != prev->dst.port_op)
PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT);
prev = cur;
cur = TAILQ_NEXT(cur, entries);
}
for (i = 0; i < PF_SKIP_COUNT; ++i)
PF_SET_SKIP_STEPS(i);
}
int
pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2)
{
if (aw1->type != aw2->type)
return (1);
switch (aw1->type) {
case PF_ADDR_ADDRMASK:
case PF_ADDR_RANGE:
if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, AF_INET6))
return (1);
if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, AF_INET6))
return (1);
return (0);
case PF_ADDR_DYNIFTL:
return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt);
case PF_ADDR_NONE:
case PF_ADDR_NOROUTE:
case PF_ADDR_URPFFAILED:
return (0);
case PF_ADDR_TABLE:
return (aw1->p.tbl != aw2->p.tbl);
case PF_ADDR_RTLABEL:
return (aw1->v.rtlabel != aw2->v.rtlabel);
default:
addlog("invalid address type: %d\n", aw1->type);
return (1);
}
}
/* This algorithm computes 'a + b - c' in ones-complement using a trick to
* emulate at most one ones-complement subtraction. This thereby limits net
* carries/borrows to at most one, eliminating a reduction step and saving one
* each of +, >>, & and ~.
*
* def. x mod y = x - (x//y)*y for integer x,y
* def. sum = x mod 2^16
* def. accumulator = (x >> 16) mod 2^16
*
* The trick works as follows: subtracting exactly one u_int16_t from the
* u_int32_t x incurs at most one underflow, wrapping its upper 16-bits, the
* accumulator, to 2^16 - 1. Adding this to the 16-bit sum preserves the
* ones-complement borrow:
*
* (sum + accumulator) mod 2^16
* = { assume underflow: accumulator := 2^16 - 1 }
* (sum + 2^16 - 1) mod 2^16
* = { mod }
* (sum - 1) mod 2^16
*
* Although this breaks for sum = 0, giving 0xffff, which is ones-complement's
* other zero, not -1, that cannot occur: the 16-bit sum cannot be underflown
* to zero as that requires subtraction of at least 2^16, which exceeds a
* single u_int16_t's range.
*
* We use the following theorem to derive the implementation:
*
* th. (x + (y mod z)) mod z = (x + y) mod z (0)
* proof.
* (x + (y mod z)) mod z
* = { def mod }
* (x + y - (y//z)*z) mod z
* = { (a + b*c) mod c = a mod c }
* (x + y) mod z [end of proof]
*
* ... and thereby obtain:
*
* (sum + accumulator) mod 2^16
* = { def. accumulator, def. sum }
* (x mod 2^16 + (x >> 16) mod 2^16) mod 2^16
* = { (0), twice }
* (x + (x >> 16)) mod 2^16
* = { x mod 2^n = x & (2^n - 1) }
* (x + (x >> 16)) & 0xffff
*
* Note: this serves also as a reduction step for at most one add (as the
* trailing mod 2^16 prevents further reductions by destroying carries).
*/
__inline void
pf_cksum_fixup(u_int16_t *cksum, u_int16_t was, u_int16_t now,
u_int8_t proto)
{
u_int32_t x;
const int udp = proto == IPPROTO_UDP;
x = *cksum + was - now;
x = (x + (x >> 16)) & 0xffff;
/* optimise: eliminate a branch when not udp */
if (udp && *cksum == 0x0000)
return;
if (udp && x == 0x0000)
x = 0xffff;
*cksum = (u_int16_t)(x);
}
#ifdef INET6
/* pre: coverage(cksum) is superset of coverage(covered_cksum) */
static __inline void
pf_cksum_uncover(u_int16_t *cksum, u_int16_t covered_cksum, u_int8_t proto)
{
pf_cksum_fixup(cksum, ~covered_cksum, 0x0, proto);
}
/* pre: disjoint(coverage(cksum), coverage(uncovered_cksum)) */
static __inline void
pf_cksum_cover(u_int16_t *cksum, u_int16_t uncovered_cksum, u_int8_t proto)
{
pf_cksum_fixup(cksum, 0x0, ~uncovered_cksum, proto);
}
#endif /* INET6 */
/* pre: *a is 16-bit aligned within its packet
*
* This algorithm emulates 16-bit ones-complement sums on a twos-complement
* machine by conserving ones-complement's otherwise discarded carries in the
* upper bits of x. These accumulated carries when added to the lower 16-bits
* over at least zero 'reduction' steps then complete the ones-complement sum.
*
* def. sum = x mod 2^16
* def. accumulator = (x >> 16)
*
* At most two reduction steps
*
* x := sum + accumulator
* = { def sum, def accumulator }
* x := x mod 2^16 + (x >> 16)
* = { x mod 2^n = x & (2^n - 1) }
* x := (x & 0xffff) + (x >> 16)
*
* are necessary to incorporate the accumulated carries (at most one per add)
* i.e. to reduce x < 2^16 from at most 16 carries in the upper 16 bits.
*
* The function is also invariant over the endian of the host. Why?
*
* Define the unary transpose operator ~ on a bitstring in python slice
* notation as lambda m: m[P:] + m[:P] , for some constant pivot P.
*
* th. ~ distributes over ones-complement addition, denoted by +_1, i.e.
*
* ~m +_1 ~n = ~(m +_1 n) (for all bitstrings m,n of equal length)
*
* proof. Regard the bitstrings in m +_1 n as split at P, forming at most two
* 'half-adds'. Under ones-complement addition, each half-add carries to the
* other, so the sum of each half-add is unaffected by their relative
* order. Therefore:
*
* ~m +_1 ~n
* = { half-adds invariant under transposition }
* ~s
* = { substitute }
* ~(m +_1 n) [end of proof]
*
* th. Summing two in-memory ones-complement 16-bit variables m,n on a machine
* with the converse endian does not alter the result.
*
* proof.
* { converse machine endian: load/store transposes, P := 8 }
* ~(~m +_1 ~n)
* = { ~ over +_1 }
* ~~m +_1 ~~n
* = { ~ is an involution }
* m +_1 n [end of proof]
*
*/
#define NEG(x) ((u_int16_t)~(x))
void
pf_cksum_fixup_a(u_int16_t *cksum, const struct pf_addr *a,
const struct pf_addr *an, sa_family_t af, u_int8_t proto)
{
u_int32_t x;
const u_int16_t *n = an->addr16;
const u_int16_t *o = a->addr16;
const int udp = proto == IPPROTO_UDP;
switch (af) {
case AF_INET:
x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]);
break;
#ifdef INET6
case AF_INET6:
x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]) +\
o[2] + NEG(n[2]) + o[3] + NEG(n[3]) +\
o[4] + NEG(n[4]) + o[5] + NEG(n[5]) +\
o[6] + NEG(n[6]) + o[7] + NEG(n[7]);
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
x = (x & 0xffff) + (x >> 16);
x = (x & 0xffff) + (x >> 16);
/* optimise: eliminate a branch when not udp */
if (udp && *cksum == 0x0000)
return;
if (udp && x == 0x0000)
x = 0xffff;
*cksum = (u_int16_t)(x);
}
int
pf_patch_8(struct pf_pdesc *pd, u_int8_t *f, u_int8_t v, bool hi)
{
int rewrite = 0;
if (*f != v) {
u_int16_t old = htons(hi ? (*f << 8) : *f);
u_int16_t new = htons(hi ? ( v << 8) : v);
pf_cksum_fixup(pd->pcksum, old, new, pd->proto);
*f = v;
rewrite = 1;
}
return (rewrite);
}
/* pre: *f is 16-bit aligned within its packet */
int
pf_patch_16(struct pf_pdesc *pd, u_int16_t *f, u_int16_t v)
{
int rewrite = 0;
if (*f != v) {
pf_cksum_fixup(pd->pcksum, *f, v, pd->proto);
*f = v;
rewrite = 1;
}
return (rewrite);
}
int
pf_patch_16_unaligned(struct pf_pdesc *pd, void *f, u_int16_t v, bool hi)
{
int rewrite = 0;
u_int8_t *fb = (u_int8_t*)f;
u_int8_t *vb = (u_int8_t*)&v;
if (hi && ALIGNED_POINTER(f, u_int16_t)) {
return (pf_patch_16(pd, f, v)); /* optimise */
}
rewrite += pf_patch_8(pd, fb++, *vb++, hi);
rewrite += pf_patch_8(pd, fb++, *vb++,!hi);
return (rewrite);
}
/* pre: *f is 16-bit aligned within its packet */
/* pre: pd->proto != IPPROTO_UDP */
int
pf_patch_32(struct pf_pdesc *pd, u_int32_t *f, u_int32_t v)
{
int rewrite = 0;
u_int16_t *pc = pd->pcksum;
u_int8_t proto = pd->proto;
/* optimise: inline udp fixup code is unused; let compiler scrub it */
if (proto == IPPROTO_UDP)
panic("%s: udp", __func__);
/* optimise: skip *f != v guard; true for all use-cases */
pf_cksum_fixup(pc, *f / (1 << 16), v / (1 << 16), proto);
pf_cksum_fixup(pc, *f % (1 << 16), v % (1 << 16), proto);
*f = v;
rewrite = 1;
return (rewrite);
}
int
pf_patch_32_unaligned(struct pf_pdesc *pd, void *f, u_int32_t v, bool hi)
{
int rewrite = 0;
u_int8_t *fb = (u_int8_t*)f;
u_int8_t *vb = (u_int8_t*)&v;
if (hi && ALIGNED_POINTER(f, u_int32_t)) {
return (pf_patch_32(pd, f, v)); /* optimise */
}
rewrite += pf_patch_8(pd, fb++, *vb++, hi);
rewrite += pf_patch_8(pd, fb++, *vb++,!hi);
rewrite += pf_patch_8(pd, fb++, *vb++, hi);
rewrite += pf_patch_8(pd, fb++, *vb++,!hi);
return (rewrite);
}
int
pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir,
u_int16_t *virtual_id, u_int16_t *virtual_type)
{
/*
* ICMP types marked with PF_OUT are typically responses to
* PF_IN, and will match states in the opposite direction.
* PF_IN ICMP types need to match a state with that type.
*/
*icmp_dir = PF_OUT;
/* Queries (and responses) */
switch (pd->af) {
case AF_INET:
switch (type) {
case ICMP_ECHO:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_ECHOREPLY:
*virtual_type = ICMP_ECHO;
*virtual_id = pd->hdr.icmp.icmp_id;
break;
case ICMP_TSTAMP:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_TSTAMPREPLY:
*virtual_type = ICMP_TSTAMP;
*virtual_id = pd->hdr.icmp.icmp_id;
break;
case ICMP_IREQ:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_IREQREPLY:
*virtual_type = ICMP_IREQ;
*virtual_id = pd->hdr.icmp.icmp_id;
break;
case ICMP_MASKREQ:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_MASKREPLY:
*virtual_type = ICMP_MASKREQ;
*virtual_id = pd->hdr.icmp.icmp_id;
break;
case ICMP_IPV6_WHEREAREYOU:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_IPV6_IAMHERE:
*virtual_type = ICMP_IPV6_WHEREAREYOU;
*virtual_id = 0; /* Nothing sane to match on! */
break;
case ICMP_MOBILE_REGREQUEST:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_MOBILE_REGREPLY:
*virtual_type = ICMP_MOBILE_REGREQUEST;
*virtual_id = 0; /* Nothing sane to match on! */
break;
case ICMP_ROUTERSOLICIT:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP_ROUTERADVERT:
*virtual_type = ICMP_ROUTERSOLICIT;
*virtual_id = 0; /* Nothing sane to match on! */
break;
/* These ICMP types map to other connections */
case ICMP_UNREACH:
case ICMP_SOURCEQUENCH:
case ICMP_REDIRECT:
case ICMP_TIMXCEED:
case ICMP_PARAMPROB:
/* These will not be used, but set them anyway */
*icmp_dir = PF_IN;
*virtual_type = htons(type);
*virtual_id = 0;
return (1); /* These types match to another state */
/*
* All remaining ICMP types get their own states,
* and will only match in one direction.
*/
default:
*icmp_dir = PF_IN;
*virtual_type = type;
*virtual_id = 0;
break;
}
break;
#ifdef INET6
case AF_INET6:
switch (type) {
case ICMP6_ECHO_REQUEST:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP6_ECHO_REPLY:
*virtual_type = ICMP6_ECHO_REQUEST;
*virtual_id = pd->hdr.icmp6.icmp6_id;
break;
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT: {
struct mld_hdr *mld = &pd->hdr.mld;
u_int32_t h;
/*
* Listener Report can be sent by clients
* without an associated Listener Query.
* In addition to that, when Report is sent as a
* reply to a Query its source and destination
* address are different.
*/
*icmp_dir = PF_IN;
*virtual_type = MLD_LISTENER_QUERY;
/* generate fake id for these messages */
h = mld->mld_addr.s6_addr32[0] ^
mld->mld_addr.s6_addr32[1] ^
mld->mld_addr.s6_addr32[2] ^
mld->mld_addr.s6_addr32[3];
*virtual_id = (h >> 16) ^ (h & 0xffff);
break;
}
/*
* ICMP6_FQDN and ICMP6_NI query/reply are the same type as
* ICMP6_WRU
*/
case ICMP6_WRUREQUEST:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ICMP6_WRUREPLY:
*virtual_type = ICMP6_WRUREQUEST;
*virtual_id = 0; /* Nothing sane to match on! */
break;
case MLD_MTRACE:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case MLD_MTRACE_RESP:
*virtual_type = MLD_MTRACE;
*virtual_id = 0; /* Nothing sane to match on! */
break;
case ND_NEIGHBOR_SOLICIT:
*icmp_dir = PF_IN;
/* FALLTHROUGH */
case ND_NEIGHBOR_ADVERT: {
struct nd_neighbor_solicit *nd = &pd->hdr.nd_ns;
u_int32_t h;
*virtual_type = ND_NEIGHBOR_SOLICIT;
/* generate fake id for these messages */
h = nd->nd_ns_target.s6_addr32[0] ^
nd->nd_ns_target.s6_addr32[1] ^
nd->nd_ns_target.s6_addr32[2] ^
nd->nd_ns_target.s6_addr32[3];
*virtual_id = (h >> 16) ^ (h & 0xffff);
/*
* the extra work here deals with 'keep state' option
* at pass rule for unsolicited advertisement. By
* returning 1 (state_icmp = 1) we override 'keep
* state' to 'no state' so we don't create state for
* unsolicited advertisements. No one expects answer to
* unsolicited advertisements so we should be good.
*/
if (type == ND_NEIGHBOR_ADVERT) {
*virtual_type = htons(*virtual_type);
return (1);
}
break;
}
/*
* These ICMP types map to other connections.
* ND_REDIRECT can't be in this list because the triggering
* packet header is optional.
*/
case ICMP6_DST_UNREACH:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PARAM_PROB:
/* These will not be used, but set them anyway */
*icmp_dir = PF_IN;
*virtual_type = htons(type);
*virtual_id = 0;
return (1); /* These types match to another state */
/*
* All remaining ICMP6 types get their own states,
* and will only match in one direction.
*/
default:
*icmp_dir = PF_IN;
*virtual_type = type;
*virtual_id = 0;
break;
}
break;
#endif /* INET6 */
}
*virtual_type = htons(*virtual_type);
return (0); /* These types match to their own state */
}
void
pf_translate_icmp(struct pf_pdesc *pd, struct pf_addr *qa, u_int16_t *qp,
struct pf_addr *oa, struct pf_addr *na, u_int16_t np)
{
/* note: doesn't trouble to fixup quoted checksums, if any */
/* change quoted protocol port */
if (qp != NULL)
pf_patch_16(pd, qp, np);
/* change quoted ip address */
pf_cksum_fixup_a(pd->pcksum, qa, na, pd->af, pd->proto);
pf_addrcpy(qa, na, pd->af);
/* change network-header's ip address */
if (oa)
pf_translate_a(pd, oa, na);
}
/* pre: *a is 16-bit aligned within its packet */
/* *a is a network header src/dst address */
int
pf_translate_a(struct pf_pdesc *pd, struct pf_addr *a, struct pf_addr *an)
{
int rewrite = 0;
/* warning: !PF_ANEQ != PF_AEQ */
if (!PF_ANEQ(a, an, pd->af))
return (0);
/* fixup transport pseudo-header, if any */
switch (pd->proto) {
case IPPROTO_TCP: /* FALLTHROUGH */
case IPPROTO_UDP: /* FALLTHROUGH */
case IPPROTO_ICMPV6:
pf_cksum_fixup_a(pd->pcksum, a, an, pd->af, pd->proto);
break;
default:
break; /* assume no pseudo-header */
}
pf_addrcpy(a, an, pd->af);
rewrite = 1;
return (rewrite);
}
#ifdef INET6
/* pf_translate_af() may change pd->m, adjust local copies after calling */
int
pf_translate_af(struct pf_pdesc *pd)
{
static const struct pf_addr zero;
struct ip *ip4;
struct ip6_hdr *ip6;
int copyback = 0;
u_int hlen, ohlen, dlen;
u_int16_t *pc;
u_int8_t af_proto, naf_proto;
hlen = (pd->naf == AF_INET) ? sizeof(*ip4) : sizeof(*ip6);
ohlen = pd->off;
dlen = pd->tot_len - pd->off;
pc = pd->pcksum;
af_proto = naf_proto = pd->proto;
if (naf_proto == IPPROTO_ICMP)
af_proto = IPPROTO_ICMPV6;
if (naf_proto == IPPROTO_ICMPV6)
af_proto = IPPROTO_ICMP;
/* uncover stale pseudo-header */
switch (af_proto) {
case IPPROTO_ICMPV6:
/* optimise: unchanged for TCP/UDP */
pf_cksum_fixup(pc, htons(af_proto), 0x0, af_proto);
pf_cksum_fixup(pc, htons(dlen), 0x0, af_proto);
/* FALLTHROUGH */
case IPPROTO_UDP: /* FALLTHROUGH */
case IPPROTO_TCP:
pf_cksum_fixup_a(pc, pd->src, &zero, pd->af, af_proto);
pf_cksum_fixup_a(pc, pd->dst, &zero, pd->af, af_proto);
copyback = 1;
break;
default:
break; /* assume no pseudo-header */
}
/* replace the network header */
m_adj(pd->m, pd->off);
pd->src = NULL;
pd->dst = NULL;
if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) {
pd->m = NULL;
return (-1);
}
pd->off = hlen;
pd->tot_len += hlen - ohlen;
switch (pd->naf) {
case AF_INET:
ip4 = mtod(pd->m, struct ip *);
memset(ip4, 0, hlen);
ip4->ip_v = IPVERSION;
ip4->ip_hl = hlen >> 2;
ip4->ip_tos = pd->tos;
ip4->ip_len = htons(hlen + dlen);
ip4->ip_id = htons(ip_randomid());
ip4->ip_off = htons(IP_DF);
ip4->ip_ttl = pd->ttl;
ip4->ip_p = pd->proto;
ip4->ip_src = pd->nsaddr.v4;
ip4->ip_dst = pd->ndaddr.v4;
break;
case AF_INET6:
ip6 = mtod(pd->m, struct ip6_hdr *);
memset(ip6, 0, hlen);
ip6->ip6_vfc = IPV6_VERSION;
ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20);
ip6->ip6_plen = htons(dlen);
ip6->ip6_nxt = pd->proto;
if (!pd->ttl || pd->ttl > IPV6_DEFHLIM)
ip6->ip6_hlim = IPV6_DEFHLIM;
else
ip6->ip6_hlim = pd->ttl;
ip6->ip6_src = pd->nsaddr.v6;
ip6->ip6_dst = pd->ndaddr.v6;
break;
default:
unhandled_af(pd->naf);
}
/* UDP over IPv6 must be checksummed per rfc2460 p27 */
if (naf_proto == IPPROTO_UDP && *pc == 0x0000 &&
pd->naf == AF_INET6) {
pd->m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
}
/* cover fresh pseudo-header */
switch (naf_proto) {
case IPPROTO_ICMPV6:
/* optimise: unchanged for TCP/UDP */
pf_cksum_fixup(pc, 0x0, htons(naf_proto), naf_proto);
pf_cksum_fixup(pc, 0x0, htons(dlen), naf_proto);
/* FALLTHROUGH */
case IPPROTO_UDP: /* FALLTHROUGH */
case IPPROTO_TCP:
pf_cksum_fixup_a(pc, &zero, &pd->nsaddr, pd->naf, naf_proto);
pf_cksum_fixup_a(pc, &zero, &pd->ndaddr, pd->naf, naf_proto);
copyback = 1;
break;
default:
break; /* assume no pseudo-header */
}
/* flush pd->pcksum */
if (copyback)
m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
return (0);
}
int
pf_change_icmp_af(struct mbuf *m, int ipoff2, struct pf_pdesc *pd,
struct pf_pdesc *pd2, struct pf_addr *src, struct pf_addr *dst,
sa_family_t af, sa_family_t naf)
{
struct mbuf *n = NULL;
struct ip *ip4;
struct ip6_hdr *ip6;
u_int hlen, ohlen, dlen;
int d;
if (af == naf || (af != AF_INET && af != AF_INET6) ||
(naf != AF_INET && naf != AF_INET6))
return (-1);
/* split the mbuf chain on the quoted ip/ip6 header boundary */
if ((n = m_split(m, ipoff2, M_DONTWAIT)) == NULL)
return (-1);
/* new quoted header */
hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6);
/* old quoted header */
ohlen = pd2->off - ipoff2;
/* trim old quoted header */
pf_cksum_uncover(pd->pcksum, in_cksum(n, ohlen), pd->proto);
m_adj(n, ohlen);
/* prepend a new, translated, quoted header */
if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL)
return (-1);
switch (naf) {
case AF_INET:
ip4 = mtod(n, struct ip *);
memset(ip4, 0, sizeof(*ip4));
ip4->ip_v = IPVERSION;
ip4->ip_hl = sizeof(*ip4) >> 2;
ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - ohlen);
ip4->ip_id = htons(ip_randomid());
ip4->ip_off = htons(IP_DF);
ip4->ip_ttl = pd2->ttl;
if (pd2->proto == IPPROTO_ICMPV6)
ip4->ip_p = IPPROTO_ICMP;
else
ip4->ip_p = pd2->proto;
ip4->ip_src = src->v4;
ip4->ip_dst = dst->v4;
in_hdr_cksum_out(n, NULL);
break;
case AF_INET6:
ip6 = mtod(n, struct ip6_hdr *);
memset(ip6, 0, sizeof(*ip6));
ip6->ip6_vfc = IPV6_VERSION;
ip6->ip6_plen = htons(pd2->tot_len - ohlen);
if (pd2->proto == IPPROTO_ICMP)
ip6->ip6_nxt = IPPROTO_ICMPV6;
else
ip6->ip6_nxt = pd2->proto;
if (!pd2->ttl || pd2->ttl > IPV6_DEFHLIM)
ip6->ip6_hlim = IPV6_DEFHLIM;
else
ip6->ip6_hlim = pd2->ttl;
ip6->ip6_src = src->v6;
ip6->ip6_dst = dst->v6;
break;
}
/* cover new quoted header */
/* optimise: any new AF_INET header of ours sums to zero */
if (naf != AF_INET) {
pf_cksum_cover(pd->pcksum, in_cksum(n, hlen), pd->proto);
}
/* reattach modified quoted packet to outer header */
{
int nlen = n->m_pkthdr.len;
m_cat(m, n);
m->m_pkthdr.len += nlen;
}
/* account for altered length */
d = hlen - ohlen;
if (pd->proto == IPPROTO_ICMPV6) {
/* fixup pseudo-header */
dlen = pd->tot_len - pd->off;
pf_cksum_fixup(pd->pcksum,
htons(dlen), htons(dlen + d), pd->proto);
}
pd->tot_len += d;
pd2->tot_len += d;
pd2->off += d;
/* note: not bothering to update network headers as
these due for rewrite by pf_translate_af() */
return (0);
}
#define PTR_IP(field) (offsetof(struct ip, field))
#define PTR_IP6(field) (offsetof(struct ip6_hdr, field))
int
pf_translate_icmp_af(struct pf_pdesc *pd, int af, void *arg)
{
struct icmp *icmp4;
struct icmp6_hdr *icmp6;
u_int32_t mtu;
int32_t ptr = -1;
u_int8_t type;
u_int8_t code;
switch (af) {
case AF_INET:
icmp6 = arg;
type = icmp6->icmp6_type;
code = icmp6->icmp6_code;
mtu = ntohl(icmp6->icmp6_mtu);
switch (type) {
case ICMP6_ECHO_REQUEST:
type = ICMP_ECHO;
break;
case ICMP6_ECHO_REPLY:
type = ICMP_ECHOREPLY;
break;
case ICMP6_DST_UNREACH:
type = ICMP_UNREACH;
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
case ICMP6_DST_UNREACH_BEYONDSCOPE:
case ICMP6_DST_UNREACH_ADDR:
code = ICMP_UNREACH_HOST;
break;
case ICMP6_DST_UNREACH_ADMIN:
code = ICMP_UNREACH_HOST_PROHIB;
break;
case ICMP6_DST_UNREACH_NOPORT:
code = ICMP_UNREACH_PORT;
break;
default:
return (-1);
}
break;
case ICMP6_PACKET_TOO_BIG:
type = ICMP_UNREACH;
code = ICMP_UNREACH_NEEDFRAG;
mtu -= 20;
break;
case ICMP6_TIME_EXCEEDED:
type = ICMP_TIMXCEED;
break;
case ICMP6_PARAM_PROB:
switch (code) {
case ICMP6_PARAMPROB_HEADER:
type = ICMP_PARAMPROB;
code = ICMP_PARAMPROB_ERRATPTR;
ptr = ntohl(icmp6->icmp6_pptr);
if (ptr == PTR_IP6(ip6_vfc))
; /* preserve */
else if (ptr == PTR_IP6(ip6_vfc) + 1)
ptr = PTR_IP(ip_tos);
else if (ptr == PTR_IP6(ip6_plen) ||
ptr == PTR_IP6(ip6_plen) + 1)
ptr = PTR_IP(ip_len);
else if (ptr == PTR_IP6(ip6_nxt))
ptr = PTR_IP(ip_p);
else if (ptr == PTR_IP6(ip6_hlim))
ptr = PTR_IP(ip_ttl);
else if (ptr >= PTR_IP6(ip6_src) &&
ptr < PTR_IP6(ip6_dst))
ptr = PTR_IP(ip_src);
else if (ptr >= PTR_IP6(ip6_dst) &&
ptr < sizeof(struct ip6_hdr))
ptr = PTR_IP(ip_dst);
else {
return (-1);
}
break;
case ICMP6_PARAMPROB_NEXTHEADER:
type = ICMP_UNREACH;
code = ICMP_UNREACH_PROTOCOL;
break;
default:
return (-1);
}
break;
default:
return (-1);
}
pf_patch_8(pd, &icmp6->icmp6_type, type, PF_HI);
pf_patch_8(pd, &icmp6->icmp6_code, code, PF_LO);
/* aligns well with a icmpv4 nextmtu */
pf_patch_32(pd, &icmp6->icmp6_mtu, htonl(mtu));
/* icmpv4 pptr is a one most significant byte */
if (ptr >= 0)
pf_patch_32(pd, &icmp6->icmp6_pptr, htonl(ptr << 24));
break;
case AF_INET6:
icmp4 = arg;
type = icmp4->icmp_type;
code = icmp4->icmp_code;
mtu = ntohs(icmp4->icmp_nextmtu);
switch (type) {
case ICMP_ECHO:
type = ICMP6_ECHO_REQUEST;
break;
case ICMP_ECHOREPLY:
type = ICMP6_ECHO_REPLY;
break;
case ICMP_UNREACH:
type = ICMP6_DST_UNREACH;
switch (code) {
case ICMP_UNREACH_NET:
case ICMP_UNREACH_HOST:
case ICMP_UNREACH_NET_UNKNOWN:
case ICMP_UNREACH_HOST_UNKNOWN:
case ICMP_UNREACH_ISOLATED:
case ICMP_UNREACH_TOSNET:
case ICMP_UNREACH_TOSHOST:
code = ICMP6_DST_UNREACH_NOROUTE;
break;
case ICMP_UNREACH_PORT:
code = ICMP6_DST_UNREACH_NOPORT;
break;
case ICMP_UNREACH_NET_PROHIB:
case ICMP_UNREACH_HOST_PROHIB:
case ICMP_UNREACH_FILTER_PROHIB:
case ICMP_UNREACH_PRECEDENCE_CUTOFF:
code = ICMP6_DST_UNREACH_ADMIN;
break;
case ICMP_UNREACH_PROTOCOL:
type = ICMP6_PARAM_PROB;
code = ICMP6_PARAMPROB_NEXTHEADER;
ptr = offsetof(struct ip6_hdr, ip6_nxt);
break;
case ICMP_UNREACH_NEEDFRAG:
type = ICMP6_PACKET_TOO_BIG;
code = 0;
mtu += 20;
break;
default:
return (-1);
}
break;
case ICMP_TIMXCEED:
type = ICMP6_TIME_EXCEEDED;
break;
case ICMP_PARAMPROB:
type = ICMP6_PARAM_PROB;
switch (code) {
case ICMP_PARAMPROB_ERRATPTR:
code = ICMP6_PARAMPROB_HEADER;
break;
case ICMP_PARAMPROB_LENGTH:
code = ICMP6_PARAMPROB_HEADER;
break;
default:
return (-1);
}
ptr = icmp4->icmp_pptr;
if (ptr == 0 || ptr == PTR_IP(ip_tos))
; /* preserve */
else if (ptr == PTR_IP(ip_len) ||
ptr == PTR_IP(ip_len) + 1)
ptr = PTR_IP6(ip6_plen);
else if (ptr == PTR_IP(ip_ttl))
ptr = PTR_IP6(ip6_hlim);
else if (ptr == PTR_IP(ip_p))
ptr = PTR_IP6(ip6_nxt);
else if (ptr >= PTR_IP(ip_src) &&
ptr < PTR_IP(ip_dst))
ptr = PTR_IP6(ip6_src);
else if (ptr >= PTR_IP(ip_dst) &&
ptr < sizeof(struct ip))
ptr = PTR_IP6(ip6_dst);
else {
return (-1);
}
break;
default:
return (-1);
}
pf_patch_8(pd, &icmp4->icmp_type, type, PF_HI);
pf_patch_8(pd, &icmp4->icmp_code, code, PF_LO);
pf_patch_16(pd, &icmp4->icmp_nextmtu, htons(mtu));
if (ptr >= 0)
pf_patch_32(pd, &icmp4->icmp_void, htonl(ptr));
break;
}
return (0);
}
#endif /* INET6 */
/*
* Need to modulate the sequence numbers in the TCP SACK option
* (credits to Krzysztof Pfaff for report and patch)
*/
int
pf_modulate_sack(struct pf_pdesc *pd, struct pf_state_peer *dst)
{
struct sackblk sack;
int copyback = 0, i;
int olen, optsoff;
u_int8_t opts[MAX_TCPOPTLEN], *opt, *eoh;
olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
optsoff = pd->off + sizeof(struct tcphdr);
#define TCPOLEN_MINSACK (TCPOLEN_SACK + 2)
if (olen < TCPOLEN_MINSACK ||
!pf_pull_hdr(pd->m, optsoff, opts, olen, NULL, pd->af))
return (0);
eoh = opts + olen;
opt = opts;
while ((opt = pf_find_tcpopt(opt, opts, olen,
TCPOPT_SACK, TCPOLEN_MINSACK)) != NULL)
{
size_t safelen = MIN(opt[1], (eoh - opt));
for (i = 2; i + TCPOLEN_SACK <= safelen; i += TCPOLEN_SACK) {
size_t startoff = (opt + i) - opts;
memcpy(&sack, &opt[i], sizeof(sack));
pf_patch_32_unaligned(pd, &sack.start,
htonl(ntohl(sack.start) - dst->seqdiff),
PF_ALGNMNT(startoff));
pf_patch_32_unaligned(pd, &sack.end,
htonl(ntohl(sack.end) - dst->seqdiff),
PF_ALGNMNT(startoff + sizeof(sack.start)));
memcpy(&opt[i], &sack, sizeof(sack));
}
copyback = 1;
opt += opt[1];
}
if (copyback)
m_copyback(pd->m, optsoff, olen, opts, M_NOWAIT);
return (copyback);
}
struct mbuf *
pf_build_tcp(const struct pf_rule *r, sa_family_t af,
const struct pf_addr *saddr, const struct pf_addr *daddr,
u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
u_int16_t rtag, u_int sack, u_int rdom)
{
struct mbuf *m;
int len, tlen;
struct ip *h;
#ifdef INET6
struct ip6_hdr *h6;
#endif /* INET6 */
struct tcphdr *th;
char *opt;
/* maximum segment size tcp option */
tlen = sizeof(struct tcphdr);
if (mss)
tlen += 4;
if (sack)
tlen += 2;
switch (af) {
case AF_INET:
len = sizeof(struct ip) + tlen;
break;
#ifdef INET6
case AF_INET6:
len = sizeof(struct ip6_hdr) + tlen;
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
/* create outgoing mbuf */
m = m_gethdr(M_DONTWAIT, MT_HEADER);
if (m == NULL)
return (NULL);
if (tag)
m->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
m->m_pkthdr.pf.tag = rtag;
m->m_pkthdr.ph_rtableid = rdom;
if (r && (r->scrub_flags & PFSTATE_SETPRIO))
m->m_pkthdr.pf.prio = r->set_prio[0];
if (r && r->qid)
m->m_pkthdr.pf.qid = r->qid;
m->m_data += max_linkhdr;
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.ph_ifidx = 0;
m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT;
memset(m->m_data, 0, len);
switch (af) {
case AF_INET:
h = mtod(m, struct ip *);
h->ip_p = IPPROTO_TCP;
h->ip_len = htons(tlen);
h->ip_v = 4;
h->ip_hl = sizeof(*h) >> 2;
h->ip_tos = IPTOS_LOWDELAY;
h->ip_len = htons(len);
h->ip_off = htons(ip_mtudisc ? IP_DF : 0);
h->ip_ttl = ttl ? ttl : ip_defttl;
h->ip_sum = 0;
h->ip_src.s_addr = saddr->v4.s_addr;
h->ip_dst.s_addr = daddr->v4.s_addr;
th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip));
break;
#ifdef INET6
case AF_INET6:
h6 = mtod(m, struct ip6_hdr *);
h6->ip6_nxt = IPPROTO_TCP;
h6->ip6_plen = htons(tlen);
h6->ip6_vfc |= IPV6_VERSION;
h6->ip6_hlim = IPV6_DEFHLIM;
memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr));
memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr));
th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr));
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
/* TCP header */
th->th_sport = sport;
th->th_dport = dport;
th->th_seq = htonl(seq);
th->th_ack = htonl(ack);
th->th_off = tlen >> 2;
th->th_flags = flags;
th->th_win = htons(win);
opt = (char *)(th + 1);
if (mss) {
opt[0] = TCPOPT_MAXSEG;
opt[1] = 4;
mss = htons(mss);
memcpy((opt + 2), &mss, 2);
opt += 4;
}
if (sack) {
opt[0] = TCPOPT_SACK_PERMITTED;
opt[1] = 2;
opt += 2;
}
return (m);
}
void
pf_send_tcp(const struct pf_rule *r, sa_family_t af,
const struct pf_addr *saddr, const struct pf_addr *daddr,
u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
u_int16_t rtag, u_int rdom)
{
struct mbuf *m;
if ((m = pf_build_tcp(r, af, saddr, daddr, sport, dport, seq, ack,
flags, win, mss, ttl, tag, rtag, 0, rdom)) == NULL)
return;
switch (af) {
case AF_INET:
ip_send(m);
break;
#ifdef INET6
case AF_INET6:
ip6_send(m);
break;
#endif /* INET6 */
}
}
static void
pf_send_challenge_ack(struct pf_pdesc *pd, struct pf_state *st,
struct pf_state_peer *src, struct pf_state_peer *dst)
{
/*
* We are sending challenge ACK as a response to SYN packet, which
* matches existing state (modulo TCP window check). Therefore packet
* must be sent on behalf of destination.
*
* We expect sender to remain either silent, or send RST packet
* so both, firewall and remote peer, can purge dead state from
* memory.
*/
pf_send_tcp(st->rule.ptr, pd->af, pd->dst, pd->src,
pd->hdr.tcp.th_dport, pd->hdr.tcp.th_sport, dst->seqlo,
src->seqlo, TH_ACK, 0, 0, st->rule.ptr->return_ttl, 1, 0,
pd->rdomain);
}
void
pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, int param,
sa_family_t af, struct pf_rule *r, u_int rdomain)
{
struct mbuf *m0;
if ((m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL)
return;
m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
m0->m_pkthdr.ph_rtableid = rdomain;
if (r && (r->scrub_flags & PFSTATE_SETPRIO))
m0->m_pkthdr.pf.prio = r->set_prio[0];
if (r && r->qid)
m0->m_pkthdr.pf.qid = r->qid;
switch (af) {
case AF_INET:
icmp_error(m0, type, code, 0, param);
break;
#ifdef INET6
case AF_INET6:
icmp6_error(m0, type, code, param);
break;
#endif /* INET6 */
}
}
/*
* Return ((n = 0) == (a = b [with mask m]))
* Note: n != 0 => returns (a != b [with mask m])
*/
int
pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m,
struct pf_addr *b, sa_family_t af)
{
switch (af) {
case AF_INET:
if ((a->addr32[0] & m->addr32[0]) ==
(b->addr32[0] & m->addr32[0]))
return (n == 0);
break;
#ifdef INET6
case AF_INET6:
if (((a->addr32[0] & m->addr32[0]) ==
(b->addr32[0] & m->addr32[0])) &&
((a->addr32[1] & m->addr32[1]) ==
(b->addr32[1] & m->addr32[1])) &&
((a->addr32[2] & m->addr32[2]) ==
(b->addr32[2] & m->addr32[2])) &&
((a->addr32[3] & m->addr32[3]) ==
(b->addr32[3] & m->addr32[3])))
return (n == 0);
break;
#endif /* INET6 */
}
return (n != 0);
}
/*
* Return 1 if b <= a <= e, otherwise return 0.
*/
int
pf_match_addr_range(struct pf_addr *b, struct pf_addr *e,
struct pf_addr *a, sa_family_t af)
{
switch (af) {
case AF_INET:
if ((ntohl(a->addr32[0]) < ntohl(b->addr32[0])) ||
(ntohl(a->addr32[0]) > ntohl(e->addr32[0])))
return (0);
break;
#ifdef INET6
case AF_INET6: {
int i;
/* check a >= b */
for (i = 0; i < 4; ++i)
if (ntohl(a->addr32[i]) > ntohl(b->addr32[i]))
break;
else if (ntohl(a->addr32[i]) < ntohl(b->addr32[i]))
return (0);
/* check a <= e */
for (i = 0; i < 4; ++i)
if (ntohl(a->addr32[i]) < ntohl(e->addr32[i]))
break;
else if (ntohl(a->addr32[i]) > ntohl(e->addr32[i]))
return (0);
break;
}
#endif /* INET6 */
}
return (1);
}
int
pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p)
{
switch (op) {
case PF_OP_IRG:
return ((p > a1) && (p < a2));
case PF_OP_XRG:
return ((p < a1) || (p > a2));
case PF_OP_RRG:
return ((p >= a1) && (p <= a2));
case PF_OP_EQ:
return (p == a1);
case PF_OP_NE:
return (p != a1);
case PF_OP_LT:
return (p < a1);
case PF_OP_LE:
return (p <= a1);
case PF_OP_GT:
return (p > a1);
case PF_OP_GE:
return (p >= a1);
}
return (0); /* never reached */
}
int
pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p)
{
return (pf_match(op, ntohs(a1), ntohs(a2), ntohs(p)));
}
int
pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u)
{
if (u == -1 && op != PF_OP_EQ && op != PF_OP_NE)
return (0);
return (pf_match(op, a1, a2, u));
}
int
pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g)
{
if (g == -1 && op != PF_OP_EQ && op != PF_OP_NE)
return (0);
return (pf_match(op, a1, a2, g));
}
int
pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag)
{
if (*tag == -1)
*tag = m->m_pkthdr.pf.tag;
return ((!r->match_tag_not && r->match_tag == *tag) ||
(r->match_tag_not && r->match_tag != *tag));
}
int
pf_match_rcvif(struct mbuf *m, struct pf_rule *r)
{
struct ifnet *ifp;
#if NCARP > 0
struct ifnet *ifp0;
#endif
struct pfi_kif *kif;
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL)
return (0);
#if NCARP > 0
if (ifp->if_type == IFT_CARP &&
(ifp0 = if_get(ifp->if_carpdevidx)) != NULL) {
kif = (struct pfi_kif *)ifp0->if_pf_kif;
if_put(ifp0);
} else
#endif /* NCARP */
kif = (struct pfi_kif *)ifp->if_pf_kif;
if_put(ifp);
if (kif == NULL) {
DPFPRINTF(LOG_ERR,
"%s: kif == NULL, @%d via %s", __func__,
r->nr, r->rcv_ifname);
return (0);
}
return (pfi_kif_match(r->rcv_kif, kif));
}
void
pf_tag_packet(struct mbuf *m, int tag, int rtableid)
{
if (tag > 0)
m->m_pkthdr.pf.tag = tag;
if (rtableid >= 0)
m->m_pkthdr.ph_rtableid = (u_int)rtableid;
}
void
pf_anchor_stack_init(void)
{
struct pf_anchor_stackframe *stack;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
stack[PF_ANCHOR_STACK_MAX].sf_stack_top = &stack[0];
cpumem_leave(pf_anchor_stack, stack);
}
int
pf_anchor_stack_is_full(struct pf_anchor_stackframe *sf)
{
struct pf_anchor_stackframe *stack;
int rv;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
rv = (sf == &stack[PF_ANCHOR_STACK_MAX]);
cpumem_leave(pf_anchor_stack, stack);
return (rv);
}
int
pf_anchor_stack_is_empty(struct pf_anchor_stackframe *sf)
{
struct pf_anchor_stackframe *stack;
int rv;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
rv = (sf == &stack[0]);
cpumem_leave(pf_anchor_stack, stack);
return (rv);
}
struct pf_anchor_stackframe *
pf_anchor_stack_top(void)
{
struct pf_anchor_stackframe *stack;
struct pf_anchor_stackframe *top_sf;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
top_sf = stack[PF_ANCHOR_STACK_MAX].sf_stack_top;
cpumem_leave(pf_anchor_stack, stack);
return (top_sf);
}
int
pf_anchor_stack_push(struct pf_ruleset *rs, struct pf_rule *r,
struct pf_anchor *child, int jump_target)
{
struct pf_anchor_stackframe *stack;
struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top();
top_sf++;
if (pf_anchor_stack_is_full(top_sf))
return (-1);
top_sf->sf_rs = rs;
top_sf->sf_r = r;
top_sf->sf_child = child;
top_sf->sf_jump_target = jump_target;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
if ((top_sf <= &stack[0]) || (top_sf >= &stack[PF_ANCHOR_STACK_MAX]))
panic("%s: top frame outside of anchor stack range", __func__);
stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf;
cpumem_leave(pf_anchor_stack, stack);
return (0);
}
int
pf_anchor_stack_pop(struct pf_ruleset **rs, struct pf_rule **r,
struct pf_anchor **child, int *jump_target)
{
struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top();
struct pf_anchor_stackframe *stack;
int on_top;
stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
if (pf_anchor_stack_is_empty(top_sf)) {
on_top = -1;
} else {
if ((top_sf <= &stack[0]) ||
(top_sf >= &stack[PF_ANCHOR_STACK_MAX]))
panic("%s: top frame outside of anchor stack range",
__func__);
*rs = top_sf->sf_rs;
*r = top_sf->sf_r;
*child = top_sf->sf_child;
*jump_target = top_sf->sf_jump_target;
top_sf--;
stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf;
on_top = 0;
}
cpumem_leave(pf_anchor_stack, stack);
return (on_top);
}
void
pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr,
struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af)
{
switch (af) {
case AF_INET:
naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
break;
#ifdef INET6
case AF_INET6:
naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) |
((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]);
naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) |
((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]);
naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) |
((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]);
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
}
void
pf_addr_inc(struct pf_addr *addr, sa_family_t af)
{
switch (af) {
case AF_INET:
addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1);
break;
#ifdef INET6
case AF_INET6:
if (addr->addr32[3] == 0xffffffff) {
addr->addr32[3] = 0;
if (addr->addr32[2] == 0xffffffff) {
addr->addr32[2] = 0;
if (addr->addr32[1] == 0xffffffff) {
addr->addr32[1] = 0;
addr->addr32[0] =
htonl(ntohl(addr->addr32[0]) + 1);
} else
addr->addr32[1] =
htonl(ntohl(addr->addr32[1]) + 1);
} else
addr->addr32[2] =
htonl(ntohl(addr->addr32[2]) + 1);
} else
addr->addr32[3] =
htonl(ntohl(addr->addr32[3]) + 1);
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
}
int
pf_socket_lookup(struct pf_pdesc *pd)
{
struct pf_addr *saddr, *daddr;
u_int16_t sport, dport;
struct inpcbtable *table;
struct inpcb *inp;
pd->lookup.uid = -1;
pd->lookup.gid = -1;
pd->lookup.pid = NO_PID;
switch (pd->virtual_proto) {
case IPPROTO_TCP:
sport = pd->hdr.tcp.th_sport;
dport = pd->hdr.tcp.th_dport;
PF_ASSERT_LOCKED();
NET_ASSERT_LOCKED();
table = &tcbtable;
break;
case IPPROTO_UDP:
sport = pd->hdr.udp.uh_sport;
dport = pd->hdr.udp.uh_dport;
PF_ASSERT_LOCKED();
NET_ASSERT_LOCKED();
table = &udbtable;
break;
default:
return (-1);
}
if (pd->dir == PF_IN) {
saddr = pd->src;
daddr = pd->dst;
} else {
u_int16_t p;
p = sport;
sport = dport;
dport = p;
saddr = pd->dst;
daddr = pd->src;
}
switch (pd->af) {
case AF_INET:
/*
* Fails when rtable is changed while evaluating the ruleset
* The socket looked up will not match the one hit in the end.
*/
inp = in_pcblookup(table, saddr->v4, sport, daddr->v4, dport,
pd->rdomain);
if (inp == NULL) {
inp = in_pcblookup_listen(table, daddr->v4, dport,
NULL, pd->rdomain);
if (inp == NULL)
return (-1);
}
break;
#ifdef INET6
case AF_INET6:
if (pd->virtual_proto == IPPROTO_UDP)
table = &udb6table;
if (pd->virtual_proto == IPPROTO_TCP)
table = &tcb6table;
inp = in6_pcblookup(table, &saddr->v6, sport, &daddr->v6,
dport, pd->rdomain);
if (inp == NULL) {
inp = in6_pcblookup_listen(table, &daddr->v6, dport,
NULL, pd->rdomain);
if (inp == NULL)
return (-1);
}
break;
#endif /* INET6 */
default:
unhandled_af(pd->af);
}
pd->lookup.uid = inp->inp_socket->so_euid;
pd->lookup.gid = inp->inp_socket->so_egid;
pd->lookup.pid = inp->inp_socket->so_cpid;
in_pcbunref(inp);
return (1);
}
/* post: r => (r[0] == type /\ r[1] >= min_typelen >= 2 "validity"
* /\ (eoh - r) >= min_typelen >= 2 "safety" )
*
* warning: r + r[1] may exceed opts bounds for r[1] > min_typelen
*/
u_int8_t*
pf_find_tcpopt(u_int8_t *opt, u_int8_t *opts, size_t hlen, u_int8_t type,
u_int8_t min_typelen)
{
u_int8_t *eoh = opts + hlen;
if (min_typelen < 2)
return (NULL);
while ((eoh - opt) >= min_typelen) {
switch (*opt) {
case TCPOPT_EOL:
/* FALLTHROUGH - Workaround the failure of some
systems to NOP-pad their bzero'd option buffers,
producing spurious EOLs */
case TCPOPT_NOP:
opt++;
continue;
default:
if (opt[0] == type &&
opt[1] >= min_typelen)
return (opt);
}
opt += MAX(opt[1], 2); /* evade infinite loops */
}
return (NULL);
}
u_int8_t
pf_get_wscale(struct pf_pdesc *pd)
{
int olen;
u_int8_t opts[MAX_TCPOPTLEN], *opt;
u_int8_t wscale = 0;
olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
if (olen < TCPOLEN_WINDOW || !pf_pull_hdr(pd->m,
pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af))
return (0);
opt = opts;
while ((opt = pf_find_tcpopt(opt, opts, olen,
TCPOPT_WINDOW, TCPOLEN_WINDOW)) != NULL) {
wscale = opt[2];
wscale = MIN(wscale, TCP_MAX_WINSHIFT);
wscale |= PF_WSCALE_FLAG;
opt += opt[1];
}
return (wscale);
}
u_int16_t
pf_get_mss(struct pf_pdesc *pd)
{
int olen;
u_int8_t opts[MAX_TCPOPTLEN], *opt;
u_int16_t mss = tcp_mssdflt;
olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
if (olen < TCPOLEN_MAXSEG || !pf_pull_hdr(pd->m,
pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af))
return (0);
opt = opts;
while ((opt = pf_find_tcpopt(opt, opts, olen,
TCPOPT_MAXSEG, TCPOLEN_MAXSEG)) != NULL) {
memcpy(&mss, (opt + 2), 2);
mss = ntohs(mss);
opt += opt[1];
}
return (mss);
}
u_int16_t
pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer)
{
struct ifnet *ifp;
struct sockaddr_in *dst;
#ifdef INET6
struct sockaddr_in6 *dst6;
#endif /* INET6 */
struct rtentry *rt = NULL;
struct sockaddr_storage ss;
int hlen;
u_int16_t mss = tcp_mssdflt;
memset(&ss, 0, sizeof(ss));
switch (af) {
case AF_INET:
hlen = sizeof(struct ip);
dst = (struct sockaddr_in *)&ss;
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = addr->v4;
rt = rtalloc(sintosa(dst), 0, rtableid);
break;
#ifdef INET6
case AF_INET6:
hlen = sizeof(struct ip6_hdr);
dst6 = (struct sockaddr_in6 *)&ss;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = addr->v6;
rt = rtalloc(sin6tosa(dst6), 0, rtableid);
break;
#endif /* INET6 */
}
if (rt != NULL && (ifp = if_get(rt->rt_ifidx)) != NULL) {
mss = ifp->if_mtu - hlen - sizeof(struct tcphdr);
mss = max(tcp_mssdflt, mss);
if_put(ifp);
}
rtfree(rt);
mss = min(mss, offer);
mss = max(mss, 64); /* sanity - at least max opt space */
return (mss);
}
static __inline int
pf_set_rt_ifp(struct pf_state *st, struct pf_addr *saddr, sa_family_t af,
struct pf_src_node **sns)
{
struct pf_rule *r = st->rule.ptr;
int rv;
if (!r->rt)
return (0);
rv = pf_map_addr(af, r, saddr, &st->rt_addr, NULL, sns,
&r->route, PF_SN_ROUTE);
if (rv == 0)
st->rt = r->rt;
return (rv);
}
u_int32_t
pf_tcp_iss(struct pf_pdesc *pd)
{
SHA2_CTX ctx;
union {
uint8_t bytes[SHA512_DIGEST_LENGTH];
uint32_t words[1];
} digest;
if (pf_tcp_secret_init == 0) {
arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret));
SHA512Init(&pf_tcp_secret_ctx);
SHA512Update(&pf_tcp_secret_ctx, pf_tcp_secret,
sizeof(pf_tcp_secret));
pf_tcp_secret_init = 1;
}
ctx = pf_tcp_secret_ctx;
SHA512Update(&ctx, &pd->rdomain, sizeof(pd->rdomain));
SHA512Update(&ctx, &pd->hdr.tcp.th_sport, sizeof(u_short));
SHA512Update(&ctx, &pd->hdr.tcp.th_dport, sizeof(u_short));
switch (pd->af) {
case AF_INET:
SHA512Update(&ctx, &pd->src->v4, sizeof(struct in_addr));
SHA512Update(&ctx, &pd->dst->v4, sizeof(struct in_addr));
break;
#ifdef INET6
case AF_INET6:
SHA512Update(&ctx, &pd->src->v6, sizeof(struct in6_addr));
SHA512Update(&ctx, &pd->dst->v6, sizeof(struct in6_addr));
break;
#endif /* INET6 */
}
SHA512Final(digest.bytes, &ctx);
pf_tcp_iss_off += 4096;
return (digest.words[0] + READ_ONCE(tcp_iss) + pf_tcp_iss_off);
}
void
pf_rule_to_actions(struct pf_rule *r, struct pf_rule_actions *a)
{
if (r->qid)
a->qid = r->qid;
if (r->pqid)
a->pqid = r->pqid;
if (r->rtableid >= 0)
a->rtableid = r->rtableid;
#if NPFLOG > 0
a->log |= r->log;
#endif /* NPFLOG > 0 */
if (r->scrub_flags & PFSTATE_SETTOS)
a->set_tos = r->set_tos;
if (r->min_ttl)
a->min_ttl = r->min_ttl;
if (r->max_mss)
a->max_mss = r->max_mss;
a->flags |= (r->scrub_flags & (PFSTATE_NODF|PFSTATE_RANDOMID|
PFSTATE_SETTOS|PFSTATE_SCRUB_TCP|PFSTATE_SETPRIO));
if (r->scrub_flags & PFSTATE_SETPRIO) {
a->set_prio[0] = r->set_prio[0];
a->set_prio[1] = r->set_prio[1];
}
if (r->rule_flag & PFRULE_SETDELAY)
a->delay = r->delay;
}
#define PF_TEST_ATTRIB(t, a) \
if (t) { \
r = a; \
continue; \
} else do { \
} while (0)
enum pf_test_status
pf_match_rule(struct pf_test_ctx *ctx, struct pf_ruleset *ruleset)
{
struct pf_rule *r;
struct pf_anchor *child = NULL;
int target;
pf_anchor_stack_init();
enter_ruleset:
r = TAILQ_FIRST(ruleset->rules.active.ptr);
while (r != NULL) {
PF_TEST_ATTRIB(r->rule_flag & PFRULE_EXPIRED,
TAILQ_NEXT(r, entries));
r->evaluations++;
PF_TEST_ATTRIB(
(pfi_kif_match(r->kif, ctx->pd->kif) == r->ifnot),
r->skip[PF_SKIP_IFP].ptr);
PF_TEST_ATTRIB((r->direction && r->direction != ctx->pd->dir),
r->skip[PF_SKIP_DIR].ptr);
PF_TEST_ATTRIB((r->onrdomain >= 0 &&
(r->onrdomain == ctx->pd->rdomain) == r->ifnot),
r->skip[PF_SKIP_RDOM].ptr);
PF_TEST_ATTRIB((r->af && r->af != ctx->pd->af),
r->skip[PF_SKIP_AF].ptr);
PF_TEST_ATTRIB((r->proto && r->proto != ctx->pd->proto),
r->skip[PF_SKIP_PROTO].ptr);
PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &ctx->pd->nsaddr,
ctx->pd->naf, r->src.neg, ctx->pd->kif,
ctx->act.rtableid)),
r->skip[PF_SKIP_SRC_ADDR].ptr);
PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &ctx->pd->ndaddr,
ctx->pd->af, r->dst.neg, NULL, ctx->act.rtableid)),
r->skip[PF_SKIP_DST_ADDR].ptr);
switch (ctx->pd->virtual_proto) {
case PF_VPROTO_FRAGMENT:
/* tcp/udp only. port_op always 0 in other cases */
PF_TEST_ATTRIB((r->src.port_op || r->dst.port_op),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((ctx->pd->proto == IPPROTO_TCP &&
r->flagset),
TAILQ_NEXT(r, entries));
/* icmp only. type/code always 0 in other cases */
PF_TEST_ATTRIB((r->type || r->code),
TAILQ_NEXT(r, entries));
/* tcp/udp only. {uid|gid}.op always 0 in other cases */
PF_TEST_ATTRIB((r->gid.op || r->uid.op),
TAILQ_NEXT(r, entries));
break;
case IPPROTO_TCP:
PF_TEST_ATTRIB(((r->flagset & ctx->th->th_flags) !=
r->flags),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY &&
!pf_osfp_match(pf_osfp_fingerprint(ctx->pd),
r->os_fingerprint)),
TAILQ_NEXT(r, entries));
/* FALLTHROUGH */
case IPPROTO_UDP:
/* tcp/udp only. port_op always 0 in other cases */
PF_TEST_ATTRIB((r->src.port_op &&
!pf_match_port(r->src.port_op, r->src.port[0],
r->src.port[1], ctx->pd->nsport)),
r->skip[PF_SKIP_SRC_PORT].ptr);
PF_TEST_ATTRIB((r->dst.port_op &&
!pf_match_port(r->dst.port_op, r->dst.port[0],
r->dst.port[1], ctx->pd->ndport)),
r->skip[PF_SKIP_DST_PORT].ptr);
/* tcp/udp only. uid.op always 0 in other cases */
PF_TEST_ATTRIB((r->uid.op && (ctx->pd->lookup.done ||
(ctx->pd->lookup.done =
pf_socket_lookup(ctx->pd), 1)) &&
!pf_match_uid(r->uid.op, r->uid.uid[0],
r->uid.uid[1], ctx->pd->lookup.uid)),
TAILQ_NEXT(r, entries));
/* tcp/udp only. gid.op always 0 in other cases */
PF_TEST_ATTRIB((r->gid.op && (ctx->pd->lookup.done ||
(ctx->pd->lookup.done =
pf_socket_lookup(ctx->pd), 1)) &&
!pf_match_gid(r->gid.op, r->gid.gid[0],
r->gid.gid[1], ctx->pd->lookup.gid)),
TAILQ_NEXT(r, entries));
break;
case IPPROTO_ICMP:
/* icmp only. type always 0 in other cases */
PF_TEST_ATTRIB((r->type &&
r->type != ctx->icmptype + 1),
TAILQ_NEXT(r, entries));
/* icmp only. type always 0 in other cases */
PF_TEST_ATTRIB((r->code &&
r->code != ctx->icmpcode + 1),
TAILQ_NEXT(r, entries));
/* icmp only. don't create states on replies */
PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp &&
(r->rule_flag & PFRULE_STATESLOPPY) == 0 &&
ctx->icmp_dir != PF_IN),
TAILQ_NEXT(r, entries));
break;
case IPPROTO_ICMPV6:
/* icmp only. type always 0 in other cases */
PF_TEST_ATTRIB((r->type &&
r->type != ctx->icmptype + 1),
TAILQ_NEXT(r, entries));
/* icmp only. type always 0 in other cases */
PF_TEST_ATTRIB((r->code &&
r->code != ctx->icmpcode + 1),
TAILQ_NEXT(r, entries));
/* icmp only. don't create states on replies */
PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp &&
(r->rule_flag & PFRULE_STATESLOPPY) == 0 &&
ctx->icmp_dir != PF_IN &&
ctx->icmptype != ND_NEIGHBOR_ADVERT),
TAILQ_NEXT(r, entries));
break;
default:
break;
}
PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT &&
ctx->pd->virtual_proto != PF_VPROTO_FRAGMENT),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->tos && !(r->tos == ctx->pd->tos)),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->prob &&
r->prob <= arc4random_uniform(UINT_MAX - 1) + 1),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->match_tag &&
!pf_match_tag(ctx->pd->m, r, &ctx->tag)),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(ctx->pd->m, r) ==
r->rcvifnot),
TAILQ_NEXT(r, entries));
PF_TEST_ATTRIB((r->prio &&
(r->prio == PF_PRIO_ZERO ? 0 : r->prio) !=
ctx->pd->m->m_pkthdr.pf.prio),
TAILQ_NEXT(r, entries));
/* must be last! */
if (r->pktrate.limit) {
pf_add_threshold(&r->pktrate);
PF_TEST_ATTRIB((pf_check_threshold(&r->pktrate)),
TAILQ_NEXT(r, entries));
}
/* FALLTHROUGH */
if (r->tag)
ctx->tag = r->tag;
if (r->anchor == NULL) {
if (r->rule_flag & PFRULE_ONCE) {
u_int32_t rule_flag;
rule_flag = r->rule_flag;
if (((rule_flag & PFRULE_EXPIRED) == 0) &&
atomic_cas_uint(&r->rule_flag, rule_flag,
rule_flag | PFRULE_EXPIRED) == rule_flag) {
r->exptime = gettime();
} else {
r = TAILQ_NEXT(r, entries);
continue;
}
}
if (r->action == PF_MATCH) {
if ((ctx->ri = pool_get(&pf_rule_item_pl,
PR_NOWAIT)) == NULL) {
REASON_SET(&ctx->reason, PFRES_MEMORY);
return (PF_TEST_FAIL);
}
ctx->ri->r = r;
/* order is irrelevant */
SLIST_INSERT_HEAD(&ctx->rules, ctx->ri, entry);
ctx->ri = NULL;
pf_rule_to_actions(r, &ctx->act);
if (r->rule_flag & PFRULE_AFTO)
ctx->pd->naf = r->naf;
if (pf_get_transaddr(r, ctx->pd, ctx->sns,
&ctx->nr) == -1) {
REASON_SET(&ctx->reason,
PFRES_TRANSLATE);
return (PF_TEST_FAIL);
}
#if NPFLOG > 0
if (r->log) {
REASON_SET(&ctx->reason, PFRES_MATCH);
pflog_packet(ctx->pd, ctx->reason, r,
ctx->a, ruleset, NULL);
}
#endif /* NPFLOG > 0 */
} else {
/*
* found matching r
*/
*ctx->rm = r;
/*
* anchor, with ruleset, where r belongs to
*/
*ctx->am = ctx->a;
/*
* ruleset where r belongs to
*/
*ctx->rsm = ruleset;
/*
* ruleset, where anchor belongs to.
*/
ctx->arsm = ctx->aruleset;
}
#if NPFLOG > 0
if (ctx->act.log & PF_LOG_MATCHES)
pf_log_matches(ctx->pd, r, ctx->a, ruleset,
&ctx->rules);
#endif /* NPFLOG > 0 */
if (r->quick)
return (PF_TEST_QUICK);
} else {
ctx->a = r;
ctx->aruleset = &r->anchor->ruleset;
if (r->anchor_wildcard) {
RB_FOREACH(child, pf_anchor_node,
&r->anchor->children) {
if (pf_anchor_stack_push(ruleset, r,
child, PF_NEXT_CHILD) != 0)
return (PF_TEST_FAIL);
ruleset = &child->ruleset;
goto enter_ruleset;
next_child:
continue; /* with RB_FOREACH() */
}
} else {
if (pf_anchor_stack_push(ruleset, r, child,
PF_NEXT_RULE) != 0)
return (PF_TEST_FAIL);
ruleset = &r->anchor->ruleset;
child = NULL;
goto enter_ruleset;
next_rule:
;
}
}
r = TAILQ_NEXT(r, entries);
}
if (pf_anchor_stack_pop(&ruleset, &r, &child, &target) == 0) {
/* stop if any rule matched within quick anchors. */
if (r->quick == PF_TEST_QUICK && *ctx->am == r)
return (PF_TEST_QUICK);
switch (target) {
case PF_NEXT_CHILD:
goto next_child;
case PF_NEXT_RULE:
goto next_rule;
default:
panic("%s: unknown jump target", __func__);
}
}
return (PF_TEST_OK);
}
int
pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, struct pf_state **sm,
struct pf_rule **am, struct pf_ruleset **rsm, u_short *reason)
{
struct pf_rule *r = NULL;
struct pf_rule *a = NULL;
struct pf_ruleset *ruleset = NULL;
struct pf_state_key *skw = NULL, *sks = NULL;
int rewrite = 0;
u_int16_t virtual_type, virtual_id;
int action = PF_DROP;
struct pf_test_ctx ctx;
int rv;
PF_ASSERT_LOCKED();
memset(&ctx, 0, sizeof(ctx));
ctx.pd = pd;
ctx.rm = rm;
ctx.am = am;
ctx.rsm = rsm;
ctx.th = &pd->hdr.tcp;
ctx.act.rtableid = pd->rdomain;
ctx.tag = -1;
SLIST_INIT(&ctx.rules);
if (pd->dir == PF_IN && if_congested()) {
REASON_SET(&ctx.reason, PFRES_CONGEST);
return (PF_DROP);
}
switch (pd->virtual_proto) {
case IPPROTO_ICMP:
ctx.icmptype = pd->hdr.icmp.icmp_type;
ctx.icmpcode = pd->hdr.icmp.icmp_code;
ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype,
&ctx.icmp_dir, &virtual_id, &virtual_type);
if (ctx.icmp_dir == PF_IN) {
pd->osport = pd->nsport = virtual_id;
pd->odport = pd->ndport = virtual_type;
} else {
pd->osport = pd->nsport = virtual_type;
pd->odport = pd->ndport = virtual_id;
}
break;
#ifdef INET6
case IPPROTO_ICMPV6:
ctx.icmptype = pd->hdr.icmp6.icmp6_type;
ctx.icmpcode = pd->hdr.icmp6.icmp6_code;
ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype,
&ctx.icmp_dir, &virtual_id, &virtual_type);
if (ctx.icmp_dir == PF_IN) {
pd->osport = pd->nsport = virtual_id;
pd->odport = pd->ndport = virtual_type;
} else {
pd->osport = pd->nsport = virtual_type;
pd->odport = pd->ndport = virtual_id;
}
break;
#endif /* INET6 */
}
ruleset = &pf_main_ruleset;
rv = pf_match_rule(&ctx, ruleset);
if (rv == PF_TEST_FAIL) {
/*
* Reason has been set in pf_match_rule() already.
*/
goto cleanup;
}
r = *ctx.rm; /* matching rule */
a = *ctx.am; /* rule that defines an anchor containing 'r' */
ruleset = *ctx.rsm;/* ruleset of the anchor defined by the rule 'a' */
ctx.aruleset = ctx.arsm;/* ruleset of the 'a' rule itself */
/* apply actions for last matching pass/block rule */
pf_rule_to_actions(r, &ctx.act);
if (r->rule_flag & PFRULE_AFTO)
pd->naf = r->naf;
if (pf_get_transaddr(r, pd, ctx.sns, &ctx.nr) == -1) {
REASON_SET(&ctx.reason, PFRES_TRANSLATE);
goto cleanup;
}
REASON_SET(&ctx.reason, PFRES_MATCH);
#if NPFLOG > 0
if (r->log)
pflog_packet(pd, ctx.reason, r, a, ruleset, NULL);
if (ctx.act.log & PF_LOG_MATCHES)
pf_log_matches(pd, r, a, ruleset, &ctx.rules);
#endif /* NPFLOG > 0 */
if (pd->virtual_proto != PF_VPROTO_FRAGMENT &&
(r->action == PF_DROP) &&
((r->rule_flag & PFRULE_RETURNRST) ||
(r->rule_flag & PFRULE_RETURNICMP) ||
(r->rule_flag & PFRULE_RETURN))) {
if (pd->proto == IPPROTO_TCP &&
((r->rule_flag & PFRULE_RETURNRST) ||
(r->rule_flag & PFRULE_RETURN)) &&
!(ctx.th->th_flags & TH_RST)) {
u_int32_t ack =
ntohl(ctx.th->th_seq) + pd->p_len;
if (pf_check_tcp_cksum(pd->m, pd->off,
pd->tot_len - pd->off, pd->af))
REASON_SET(&ctx.reason, PFRES_PROTCKSUM);
else {
if (ctx.th->th_flags & TH_SYN)
ack++;
if (ctx.th->th_flags & TH_FIN)
ack++;
pf_send_tcp(r, pd->af, pd->dst,
pd->src, ctx.th->th_dport,
ctx.th->th_sport, ntohl(ctx.th->th_ack),
ack, TH_RST|TH_ACK, 0, 0, r->return_ttl,
1, 0, pd->rdomain);
}
} else if ((pd->proto != IPPROTO_ICMP ||
ICMP_INFOTYPE(ctx.icmptype)) && pd->af == AF_INET &&
r->return_icmp)
pf_send_icmp(pd->m, r->return_icmp >> 8,
r->return_icmp & 255, 0, pd->af, r, pd->rdomain);
else if ((pd->proto != IPPROTO_ICMPV6 ||
(ctx.icmptype >= ICMP6_ECHO_REQUEST &&
ctx.icmptype != ND_REDIRECT)) && pd->af == AF_INET6 &&
r->return_icmp6)
pf_send_icmp(pd->m, r->return_icmp6 >> 8,
r->return_icmp6 & 255, 0, pd->af, r, pd->rdomain);
}
if (r->action == PF_DROP)
goto cleanup;
pf_tag_packet(pd->m, ctx.tag, ctx.act.rtableid);
if (ctx.act.rtableid >= 0 &&
rtable_l2(ctx.act.rtableid) != pd->rdomain)
pd->destchg = 1;
if (r->action == PF_PASS && pd->badopts != 0 && ! r->allow_opts) {
REASON_SET(&ctx.reason, PFRES_IPOPTIONS);
#if NPFLOG > 0
pd->pflog |= PF_LOG_FORCE;
#endif /* NPFLOG > 0 */
DPFPRINTF(LOG_NOTICE, "dropping packet with "
"ip/ipv6 options in pf_test_rule()");
goto cleanup;
}
if (pd->virtual_proto != PF_VPROTO_FRAGMENT
&& !ctx.state_icmp && r->keep_state) {
if (r->rule_flag & PFRULE_SRCTRACK &&
pf_insert_src_node(&ctx.sns[PF_SN_NONE], r, PF_SN_NONE,
pd->af, pd->src, NULL, NULL) != 0) {
REASON_SET(&ctx.reason, PFRES_SRCLIMIT);
goto cleanup;
}
if (r->max_states && (r->states_cur >= r->max_states)) {
pf_status.lcounters[LCNT_STATES]++;
REASON_SET(&ctx.reason, PFRES_MAXSTATES);
goto cleanup;
}
action = pf_create_state(pd, r, a, ctx.nr, &skw, &sks,
&rewrite, sm, ctx.tag, &ctx.rules, &ctx.act, ctx.sns);
if (action != PF_PASS)
goto cleanup;
if (sks != skw) {
struct pf_state_key *sk;
if (pd->dir == PF_IN)
sk = sks;
else
sk = skw;
rewrite += pf_translate(pd,
&sk->addr[pd->af == pd->naf ? pd->sidx : pd->didx],
sk->port[pd->af == pd->naf ? pd->sidx : pd->didx],
&sk->addr[pd->af == pd->naf ? pd->didx : pd->sidx],
sk->port[pd->af == pd->naf ? pd->didx : pd->sidx],
virtual_type, ctx.icmp_dir);
}
#ifdef INET6
if (rewrite && skw->af != sks->af)
action = PF_AFRT;
#endif /* INET6 */
} else {
action = PF_PASS;
while ((ctx.ri = SLIST_FIRST(&ctx.rules))) {
SLIST_REMOVE_HEAD(&ctx.rules, entry);
pool_put(&pf_rule_item_pl, ctx.ri);
}
}
/* copy back packet headers if needed */
if (rewrite && pd->hdrlen) {
m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
}
#if NPFSYNC > 0
if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) &&
pd->dir == PF_OUT && pfsync_is_up()) {
/*
* We want the state created, but we dont
* want to send this in case a partner
* firewall has to know about it to allow
* replies through it.
*/
if (pfsync_defer(*sm, pd->m))
return (PF_DEFER);
}
#endif /* NPFSYNC > 0 */
return (action);
cleanup:
while ((ctx.ri = SLIST_FIRST(&ctx.rules))) {
SLIST_REMOVE_HEAD(&ctx.rules, entry);
pool_put(&pf_rule_item_pl, ctx.ri);
}
return (action);
}
static __inline int
pf_create_state(struct pf_pdesc *pd, struct pf_rule *r, struct pf_rule *a,
struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks,
int *rewrite, struct pf_state **sm, int tag, struct pf_rule_slist *rules,
struct pf_rule_actions *act, struct pf_src_node *sns[PF_SN_MAX])
{
struct pf_state *st = NULL;
struct tcphdr *th = &pd->hdr.tcp;
u_int16_t mss = tcp_mssdflt;
u_short reason;
u_int i;
st = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO);
if (st == NULL) {
REASON_SET(&reason, PFRES_MEMORY);
goto csfailed;
}
st->rule.ptr = r;
st->anchor.ptr = a;
st->natrule.ptr = nr;
if (r->allow_opts)
st->state_flags |= PFSTATE_ALLOWOPTS;
if (r->rule_flag & PFRULE_STATESLOPPY)
st->state_flags |= PFSTATE_SLOPPY;
if (r->rule_flag & PFRULE_PFLOW)
st->state_flags |= PFSTATE_PFLOW;
if (r->rule_flag & PFRULE_NOSYNC)
st->state_flags |= PFSTATE_NOSYNC;
#if NPFLOG > 0
st->log = act->log & PF_LOG_ALL;
#endif /* NPFLOG > 0 */
st->qid = act->qid;
st->pqid = act->pqid;
st->rtableid[pd->didx] = act->rtableid;
st->rtableid[pd->sidx] = -1; /* return traffic is routed normally */
st->min_ttl = act->min_ttl;
st->set_tos = act->set_tos;
st->max_mss = act->max_mss;
st->state_flags |= act->flags;
#if NPFSYNC > 0
st->sync_state = PFSYNC_S_NONE;
#endif /* NPFSYNC > 0 */
st->set_prio[0] = act->set_prio[0];
st->set_prio[1] = act->set_prio[1];
st->delay = act->delay;
SLIST_INIT(&st->src_nodes);
/*
* must initialize refcnt, before pf_state_insert() gets called.
* pf_state_inserts() grabs reference for pfsync!
*/
PF_REF_INIT(st->refcnt);
mtx_init(&st->mtx, IPL_NET);
switch (pd->proto) {
case IPPROTO_TCP:
st->src.seqlo = ntohl(th->th_seq);
st->src.seqhi = st->src.seqlo + pd->p_len + 1;
if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN &&
r->keep_state == PF_STATE_MODULATE) {
/* Generate sequence number modulator */
st->src.seqdiff = pf_tcp_iss(pd) - st->src.seqlo;
if (st->src.seqdiff == 0)
st->src.seqdiff = 1;
pf_patch_32(pd, &th->th_seq,
htonl(st->src.seqlo + st->src.seqdiff));
*rewrite = 1;
} else
st->src.seqdiff = 0;
if (th->th_flags & TH_SYN) {
st->src.seqhi++;
st->src.wscale = pf_get_wscale(pd);
}
st->src.max_win = MAX(ntohs(th->th_win), 1);
if (st->src.wscale & PF_WSCALE_MASK) {
/* Remove scale factor from initial window */
int win = st->src.max_win;
win += 1 << (st->src.wscale & PF_WSCALE_MASK);
st->src.max_win = (win - 1) >>
(st->src.wscale & PF_WSCALE_MASK);
}
if (th->th_flags & TH_FIN)
st->src.seqhi++;
st->dst.seqhi = 1;
st->dst.max_win = 1;
pf_set_protostate(st, PF_PEER_SRC, TCPS_SYN_SENT);
pf_set_protostate(st, PF_PEER_DST, TCPS_CLOSED);
st->timeout = PFTM_TCP_FIRST_PACKET;
pf_status.states_halfopen++;
break;
case IPPROTO_UDP:
pf_set_protostate(st, PF_PEER_SRC, PFUDPS_SINGLE);
pf_set_protostate(st, PF_PEER_DST, PFUDPS_NO_TRAFFIC);
st->timeout = PFTM_UDP_FIRST_PACKET;
break;
case IPPROTO_ICMP:
#ifdef INET6
case IPPROTO_ICMPV6:
#endif /* INET6 */
st->timeout = PFTM_ICMP_FIRST_PACKET;
break;
default:
pf_set_protostate(st, PF_PEER_SRC, PFOTHERS_SINGLE);
pf_set_protostate(st, PF_PEER_DST, PFOTHERS_NO_TRAFFIC);
st->timeout = PFTM_OTHER_FIRST_PACKET;
}
st->creation = getuptime();
st->expire = getuptime();
if (pd->proto == IPPROTO_TCP) {
if (st->state_flags & PFSTATE_SCRUB_TCP &&
pf_normalize_tcp_init(pd, &st->src)) {
REASON_SET(&reason, PFRES_MEMORY);
goto csfailed;
}
if (st->state_flags & PFSTATE_SCRUB_TCP && st->src.scrub &&
pf_normalize_tcp_stateful(pd, &reason, st,
&st->src, &st->dst, rewrite)) {
/* This really shouldn't happen!!! */
DPFPRINTF(LOG_ERR,
"%s: tcp normalize failed on first pkt", __func__);
goto csfailed;
}
}
st->direction = pd->dir;
if (pf_state_key_setup(pd, skw, sks, act->rtableid)) {
REASON_SET(&reason, PFRES_MEMORY);
goto csfailed;
}
if (pf_set_rt_ifp(st, pd->src, (*skw)->af, sns) != 0) {
REASON_SET(&reason, PFRES_NOROUTE);
goto csfailed;
}
for (i = 0; i < PF_SN_MAX; i++)
if (sns[i] != NULL) {
struct pf_sn_item *sni;
sni = pool_get(&pf_sn_item_pl, PR_NOWAIT);
if (sni == NULL) {
REASON_SET(&reason, PFRES_MEMORY);
goto csfailed;
}
sni->sn = sns[i];
SLIST_INSERT_HEAD(&st->src_nodes, sni, next);
sni->sn->states++;
}
#if NPFSYNC > 0
pfsync_init_state(st, *skw, *sks, 0);
#endif
if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, st)) {
*sks = *skw = NULL;
REASON_SET(&reason, PFRES_STATEINS);
goto csfailed;
} else
*sm = st;
/*
* Make state responsible for rules it binds here.
*/
memcpy(&st->match_rules, rules, sizeof(st->match_rules));
memset(rules, 0, sizeof(*rules));
STATE_INC_COUNTERS(st);
if (tag > 0) {
pf_tag_ref(tag);
st->tag = tag;
}
if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) ==
TH_SYN && r->keep_state == PF_STATE_SYNPROXY && pd->dir == PF_IN) {
int rtid = pd->rdomain;
if (act->rtableid >= 0)
rtid = act->rtableid;
pf_set_protostate(st, PF_PEER_SRC, PF_TCPS_PROXY_SRC);
st->src.seqhi = arc4random();
/* Find mss option */
mss = pf_get_mss(pd);
mss = pf_calc_mss(pd->src, pd->af, rtid, mss);
mss = pf_calc_mss(pd->dst, pd->af, rtid, mss);
st->src.mss = mss;
pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport,
th->th_sport, st->src.seqhi, ntohl(th->th_seq) + 1,
TH_SYN|TH_ACK, 0, st->src.mss, 0, 1, 0, pd->rdomain);
REASON_SET(&reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
return (PF_PASS);
csfailed:
if (st) {
pf_normalize_tcp_cleanup(st); /* safe even w/o init */
pf_src_tree_remove_state(st);
pool_put(&pf_state_pl, st);
}
for (i = 0; i < PF_SN_MAX; i++)
if (sns[i] != NULL)
pf_remove_src_node(sns[i]);
return (PF_DROP);
}
int
pf_translate(struct pf_pdesc *pd, struct pf_addr *saddr, u_int16_t sport,
struct pf_addr *daddr, u_int16_t dport, u_int16_t virtual_type,
int icmp_dir)
{
int rewrite = 0;
int afto = pd->af != pd->naf;
if (afto || PF_ANEQ(daddr, pd->dst, pd->af))
pd->destchg = 1;
switch (pd->proto) {
case IPPROTO_TCP: /* FALLTHROUGH */
case IPPROTO_UDP:
rewrite += pf_patch_16(pd, pd->sport, sport);
rewrite += pf_patch_16(pd, pd->dport, dport);
break;
case IPPROTO_ICMP:
if (pd->af != AF_INET)
return (0);
#ifdef INET6
if (afto) {
if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp))
return (0);
pd->proto = IPPROTO_ICMPV6;
rewrite = 1;
}
#endif /* INET6 */
if (virtual_type == htons(ICMP_ECHO)) {
u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport;
rewrite += pf_patch_16(pd,
&pd->hdr.icmp.icmp_id, icmpid);
}
break;
#ifdef INET6
case IPPROTO_ICMPV6:
if (pd->af != AF_INET6)
return (0);
if (afto) {
if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6))
return (0);
pd->proto = IPPROTO_ICMP;
rewrite = 1;
}
if (virtual_type == htons(ICMP6_ECHO_REQUEST)) {
u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport;
rewrite += pf_patch_16(pd,
&pd->hdr.icmp6.icmp6_id, icmpid);
}
break;
#endif /* INET6 */
}
if (!afto) {
rewrite += pf_translate_a(pd, pd->src, saddr);
rewrite += pf_translate_a(pd, pd->dst, daddr);
}
return (rewrite);
}
int
pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason,
int *copyback, int reverse)
{
struct tcphdr *th = &pd->hdr.tcp;
struct pf_state_peer *src, *dst;
u_int16_t win = ntohs(th->th_win);
u_int32_t ack, end, data_end, seq, orig_seq;
u_int8_t sws, dws, psrc, pdst;
int ackskew;
if ((pd->dir == (*stp)->direction && !reverse) ||
(pd->dir != (*stp)->direction && reverse)) {
src = &(*stp)->src;
dst = &(*stp)->dst;
psrc = PF_PEER_SRC;
pdst = PF_PEER_DST;
} else {
src = &(*stp)->dst;
dst = &(*stp)->src;
psrc = PF_PEER_DST;
pdst = PF_PEER_SRC;
}
if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) {
sws = src->wscale & PF_WSCALE_MASK;
dws = dst->wscale & PF_WSCALE_MASK;
} else
sws = dws = 0;
/*
* Sequence tracking algorithm from Guido van Rooij's paper:
* http://www.madison-gurkha.com/publications/tcp_filtering/
* tcp_filtering.ps
*/
orig_seq = seq = ntohl(th->th_seq);
if (src->seqlo == 0) {
/* First packet from this end. Set its state */
if (((*stp)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) &&
src->scrub == NULL) {
if (pf_normalize_tcp_init(pd, src)) {
REASON_SET(reason, PFRES_MEMORY);
return (PF_DROP);
}
}
/* Deferred generation of sequence number modulator */
if (dst->seqdiff && !src->seqdiff) {
/* use random iss for the TCP server */
while ((src->seqdiff = arc4random() - seq) == 0)
continue;
ack = ntohl(th->th_ack) - dst->seqdiff;
pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff));
pf_patch_32(pd, &th->th_ack, htonl(ack));
*copyback = 1;
} else {
ack = ntohl(th->th_ack);
}
end = seq + pd->p_len;
if (th->th_flags & TH_SYN) {
end++;
if (dst->wscale & PF_WSCALE_FLAG) {
src->wscale = pf_get_wscale(pd);
if (src->wscale & PF_WSCALE_FLAG) {
/* Remove scale factor from initial
* window */
sws = src->wscale & PF_WSCALE_MASK;
win = ((u_int32_t)win + (1 << sws) - 1)
>> sws;
dws = dst->wscale & PF_WSCALE_MASK;
} else {
/* fixup other window */
dst->max_win = MIN(TCP_MAXWIN,
(u_int32_t)dst->max_win <<
(dst->wscale & PF_WSCALE_MASK));
/* in case of a retrans SYN|ACK */
dst->wscale = 0;
}
}
}
data_end = end;
if (th->th_flags & TH_FIN)
end++;
src->seqlo = seq;
if (src->state < TCPS_SYN_SENT)
pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);
/*
* May need to slide the window (seqhi may have been set by
* the crappy stack check or if we picked up the connection
* after establishment)
*/
if (src->seqhi == 1 ||
SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi))
src->seqhi = end + MAX(1, dst->max_win << dws);
if (win > src->max_win)
src->max_win = win;
} else {
ack = ntohl(th->th_ack) - dst->seqdiff;
if (src->seqdiff) {
/* Modulate sequence numbers */
pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff));
pf_patch_32(pd, &th->th_ack, htonl(ack));
*copyback = 1;
}
end = seq + pd->p_len;
if (th->th_flags & TH_SYN)
end++;
data_end = end;
if (th->th_flags & TH_FIN)
end++;
}
if ((th->th_flags & TH_ACK) == 0) {
/* Let it pass through the ack skew check */
ack = dst->seqlo;
} else if ((ack == 0 &&
(th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) ||
/* broken tcp stacks do not set ack */
(dst->state < TCPS_SYN_SENT)) {
/*
* Many stacks (ours included) will set the ACK number in an
* FIN|ACK if the SYN times out -- no sequence to ACK.
*/
ack = dst->seqlo;
}
if (seq == end) {
/* Ease sequencing restrictions on no data packets */
seq = src->seqlo;
data_end = end = seq;
}
ackskew = dst->seqlo - ack;
/*
* Need to demodulate the sequence numbers in any TCP SACK options
* (Selective ACK). We could optionally validate the SACK values
* against the current ACK window, either forwards or backwards, but
* I'm not confident that SACK has been implemented properly
* everywhere. It wouldn't surprise me if several stacks accidently
* SACK too far backwards of previously ACKed data. There really aren't
* any security implications of bad SACKing unless the target stack
* doesn't validate the option length correctly. Someone trying to
* spoof into a TCP connection won't bother blindly sending SACK
* options anyway.
*/
if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) {
if (pf_modulate_sack(pd, dst))
*copyback = 1;
}
#define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */
if (SEQ_GEQ(src->seqhi, data_end) &&
/* Last octet inside other's window space */
SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) &&
/* Retrans: not more than one window back */
(ackskew >= -MAXACKWINDOW) &&
/* Acking not more than one reassembled fragment backwards */
(ackskew <= (MAXACKWINDOW << sws)) &&
/* Acking not more than one window forward */
((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo ||
(orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo))) {
/* Require an exact/+1 sequence match on resets when possible */
if (dst->scrub || src->scrub) {
if (pf_normalize_tcp_stateful(pd, reason, *stp, src,
dst, copyback))
return (PF_DROP);
}
/* update max window */
if (src->max_win < win)
src->max_win = win;
/* synchronize sequencing */
if (SEQ_GT(end, src->seqlo))
src->seqlo = end;
/* slide the window of what the other end can send */
if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
dst->seqhi = ack + MAX((win << sws), 1);
/* update states */
if (th->th_flags & TH_SYN)
if (src->state < TCPS_SYN_SENT)
pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
pf_set_protostate(*stp, psrc, TCPS_CLOSING);
if (th->th_flags & TH_ACK) {
if (dst->state == TCPS_SYN_SENT) {
pf_set_protostate(*stp, pdst,
TCPS_ESTABLISHED);
if (src->state == TCPS_ESTABLISHED &&
!SLIST_EMPTY(&(*stp)->src_nodes) &&
pf_src_connlimit(stp)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (dst->state == TCPS_CLOSING)
pf_set_protostate(*stp, pdst,
TCPS_FIN_WAIT_2);
}
if (th->th_flags & TH_RST)
pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);
/* update expire time */
(*stp)->expire = getuptime();
if (src->state >= TCPS_FIN_WAIT_2 &&
dst->state >= TCPS_FIN_WAIT_2)
pf_update_state_timeout(*stp, PFTM_TCP_CLOSED);
else if (src->state >= TCPS_CLOSING &&
dst->state >= TCPS_CLOSING)
pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT);
else if (src->state < TCPS_ESTABLISHED ||
dst->state < TCPS_ESTABLISHED)
pf_update_state_timeout(*stp, PFTM_TCP_OPENING);
else if (src->state >= TCPS_CLOSING ||
dst->state >= TCPS_CLOSING)
pf_update_state_timeout(*stp, PFTM_TCP_CLOSING);
else
pf_update_state_timeout(*stp, PFTM_TCP_ESTABLISHED);
/* Fall through to PASS packet */
} else if ((dst->state < TCPS_SYN_SENT ||
dst->state >= TCPS_FIN_WAIT_2 ||
src->state >= TCPS_FIN_WAIT_2) &&
SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) &&
/* Within a window forward of the originating packet */
SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) {
/* Within a window backward of the originating packet */
/*
* This currently handles three situations:
* 1) Stupid stacks will shotgun SYNs before their peer
* replies.
* 2) When PF catches an already established stream (the
* firewall rebooted, the state table was flushed, routes
* changed...)
* 3) Packets get funky immediately after the connection
* closes (this should catch Solaris spurious ACK|FINs
* that web servers like to spew after a close)
*
* This must be a little more careful than the above code
* since packet floods will also be caught here. We don't
* update the TTL here to mitigate the damage of a packet
* flood and so the same code can handle awkward establishment
* and a loosened connection close.
* In the establishment case, a correct peer response will
* validate the connection, go through the normal state code
* and keep updating the state TTL.
*/
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE, "pf: loose state match: ");
pf_print_state(*stp);
pf_print_flags(th->th_flags);
addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d "
"pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack,
pd->p_len, ackskew, (*stp)->packets[0],
(*stp)->packets[1],
pd->dir == PF_IN ? "in" : "out",
pd->dir == (*stp)->direction ? "fwd" : "rev");
}
if (dst->scrub || src->scrub) {
if (pf_normalize_tcp_stateful(pd, reason, *stp, src,
dst, copyback))
return (PF_DROP);
}
/* update max window */
if (src->max_win < win)
src->max_win = win;
/* synchronize sequencing */
if (SEQ_GT(end, src->seqlo))
src->seqlo = end;
/* slide the window of what the other end can send */
if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
dst->seqhi = ack + MAX((win << sws), 1);
/*
* Cannot set dst->seqhi here since this could be a shotgunned
* SYN and not an already established connection.
*/
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
pf_set_protostate(*stp, psrc, TCPS_CLOSING);
if (th->th_flags & TH_RST)
pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);
/* Fall through to PASS packet */
} else {
if ((*stp)->dst.state == TCPS_SYN_SENT &&
(*stp)->src.state == TCPS_SYN_SENT) {
/* Send RST for state mismatches during handshake */
if (!(th->th_flags & TH_RST))
pf_send_tcp((*stp)->rule.ptr, pd->af,
pd->dst, pd->src, th->th_dport,
th->th_sport, ntohl(th->th_ack), 0,
TH_RST, 0, 0,
(*stp)->rule.ptr->return_ttl, 1, 0,
pd->rdomain);
src->seqlo = 0;
src->seqhi = 1;
src->max_win = 1;
} else if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE, "pf: BAD state: ");
pf_print_state(*stp);
pf_print_flags(th->th_flags);
addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d "
"pkts=%llu:%llu dir=%s,%s\n",
seq, orig_seq, ack, pd->p_len, ackskew,
(*stp)->packets[0], (*stp)->packets[1],
pd->dir == PF_IN ? "in" : "out",
pd->dir == (*stp)->direction ? "fwd" : "rev");
addlog("pf: State failure on: %c %c %c %c | %c %c\n",
SEQ_GEQ(src->seqhi, data_end) ? ' ' : '1',
SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ?
' ': '2',
(ackskew >= -MAXACKWINDOW) ? ' ' : '3',
(ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4',
SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) ?
' ' :'5',
SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6');
}
REASON_SET(reason, PFRES_BADSTATE);
return (PF_DROP);
}
return (PF_PASS);
}
int
pf_tcp_track_sloppy(struct pf_pdesc *pd, struct pf_state **stp,
u_short *reason)
{
struct tcphdr *th = &pd->hdr.tcp;
struct pf_state_peer *src, *dst;
u_int8_t psrc, pdst;
if (pd->dir == (*stp)->direction) {
src = &(*stp)->src;
dst = &(*stp)->dst;
psrc = PF_PEER_SRC;
pdst = PF_PEER_DST;
} else {
src = &(*stp)->dst;
dst = &(*stp)->src;
psrc = PF_PEER_DST;
pdst = PF_PEER_SRC;
}
if (th->th_flags & TH_SYN)
if (src->state < TCPS_SYN_SENT)
pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
pf_set_protostate(*stp, psrc, TCPS_CLOSING);
if (th->th_flags & TH_ACK) {
if (dst->state == TCPS_SYN_SENT) {
pf_set_protostate(*stp, pdst, TCPS_ESTABLISHED);
if (src->state == TCPS_ESTABLISHED &&
!SLIST_EMPTY(&(*stp)->src_nodes) &&
pf_src_connlimit(stp)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (dst->state == TCPS_CLOSING) {
pf_set_protostate(*stp, pdst, TCPS_FIN_WAIT_2);
} else if (src->state == TCPS_SYN_SENT &&
dst->state < TCPS_SYN_SENT) {
/*
* Handle a special sloppy case where we only see one
* half of the connection. If there is a ACK after
* the initial SYN without ever seeing a packet from
* the destination, set the connection to established.
*/
pf_set_protostate(*stp, PF_PEER_BOTH,
TCPS_ESTABLISHED);
if (!SLIST_EMPTY(&(*stp)->src_nodes) &&
pf_src_connlimit(stp)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (src->state == TCPS_CLOSING &&
dst->state == TCPS_ESTABLISHED &&
dst->seqlo == 0) {
/*
* Handle the closing of half connections where we
* don't see the full bidirectional FIN/ACK+ACK
* handshake.
*/
pf_set_protostate(*stp, pdst, TCPS_CLOSING);
}
}
if (th->th_flags & TH_RST)
pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);
/* update expire time */
(*stp)->expire = getuptime();
if (src->state >= TCPS_FIN_WAIT_2 &&
dst->state >= TCPS_FIN_WAIT_2)
pf_update_state_timeout(*stp, PFTM_TCP_CLOSED);
else if (src->state >= TCPS_CLOSING &&
dst->state >= TCPS_CLOSING)
pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT);
else if (src->state < TCPS_ESTABLISHED ||
dst->state < TCPS_ESTABLISHED)
pf_update_state_timeout(*stp, PFTM_TCP_OPENING);
else if (src->state >= TCPS_CLOSING ||
dst->state >= TCPS_CLOSING)
pf_update_state_timeout(*stp, PFTM_TCP_CLOSING);
else
pf_update_state_timeout(*stp, PFTM_TCP_ESTABLISHED);
return (PF_PASS);
}
static __inline int
pf_synproxy(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason)
{
struct pf_state_key *sk = (*stp)->key[pd->didx];
if ((*stp)->src.state == PF_TCPS_PROXY_SRC) {
struct tcphdr *th = &pd->hdr.tcp;
if (pd->dir != (*stp)->direction) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
if (th->th_flags & TH_SYN) {
if (ntohl(th->th_seq) != (*stp)->src.seqlo) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
}
pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst,
pd->src, th->th_dport, th->th_sport,
(*stp)->src.seqhi, ntohl(th->th_seq) + 1,
TH_SYN|TH_ACK, 0, (*stp)->src.mss, 0, 1,
0, pd->rdomain);
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
} else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK ||
(ntohl(th->th_ack) != (*stp)->src.seqhi + 1) ||
(ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
} else if (!SLIST_EMPTY(&(*stp)->src_nodes) &&
pf_src_connlimit(stp)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
} else
pf_set_protostate(*stp, PF_PEER_SRC,
PF_TCPS_PROXY_DST);
}
if ((*stp)->src.state == PF_TCPS_PROXY_DST) {
struct tcphdr *th = &pd->hdr.tcp;
if (pd->dir == (*stp)->direction) {
if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) ||
(ntohl(th->th_ack) != (*stp)->src.seqhi + 1) ||
(ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
}
(*stp)->src.max_win = MAX(ntohs(th->th_win), 1);
if ((*stp)->dst.seqhi == 1)
(*stp)->dst.seqhi = arc4random();
pf_send_tcp((*stp)->rule.ptr, pd->af,
&sk->addr[pd->sidx], &sk->addr[pd->didx],
sk->port[pd->sidx], sk->port[pd->didx],
(*stp)->dst.seqhi, 0, TH_SYN, 0,
(*stp)->src.mss, 0, 0, (*stp)->tag,
sk->rdomain);
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
} else if (((th->th_flags & (TH_SYN|TH_ACK)) !=
(TH_SYN|TH_ACK)) ||
(ntohl(th->th_ack) != (*stp)->dst.seqhi + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
} else {
(*stp)->dst.max_win = MAX(ntohs(th->th_win), 1);
(*stp)->dst.seqlo = ntohl(th->th_seq);
pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst,
pd->src, th->th_dport, th->th_sport,
ntohl(th->th_ack), ntohl(th->th_seq) + 1,
TH_ACK, (*stp)->src.max_win, 0, 0, 0,
(*stp)->tag, pd->rdomain);
pf_send_tcp((*stp)->rule.ptr, pd->af,
&sk->addr[pd->sidx], &sk->addr[pd->didx],
sk->port[pd->sidx], sk->port[pd->didx],
(*stp)->src.seqhi + 1, (*stp)->src.seqlo + 1,
TH_ACK, (*stp)->dst.max_win, 0, 0, 1,
0, sk->rdomain);
(*stp)->src.seqdiff = (*stp)->dst.seqhi -
(*stp)->src.seqlo;
(*stp)->dst.seqdiff = (*stp)->src.seqhi -
(*stp)->dst.seqlo;
(*stp)->src.seqhi = (*stp)->src.seqlo +
(*stp)->dst.max_win;
(*stp)->dst.seqhi = (*stp)->dst.seqlo +
(*stp)->src.max_win;
(*stp)->src.wscale = (*stp)->dst.wscale = 0;
pf_set_protostate(*stp, PF_PEER_BOTH,
TCPS_ESTABLISHED);
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
}
return (PF_PASS);
}
int
pf_test_state(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason)
{
int copyback = 0;
struct pf_state_peer *src, *dst;
int action;
struct inpcb *inp = pd->m->m_pkthdr.pf.inp;
u_int8_t psrc, pdst;
action = PF_PASS;
if (pd->dir == (*stp)->direction) {
src = &(*stp)->src;
dst = &(*stp)->dst;
psrc = PF_PEER_SRC;
pdst = PF_PEER_DST;
} else {
src = &(*stp)->dst;
dst = &(*stp)->src;
psrc = PF_PEER_DST;
pdst = PF_PEER_SRC;
}
switch (pd->virtual_proto) {
case IPPROTO_TCP:
if ((action = pf_synproxy(pd, stp, reason)) != PF_PASS)
return (action);
if ((pd->hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN) {
if (dst->state >= TCPS_FIN_WAIT_2 &&
src->state >= TCPS_FIN_WAIT_2) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE, "pf: state reuse ");
pf_print_state(*stp);
pf_print_flags(pd->hdr.tcp.th_flags);
addlog("\n");
}
/* XXX make sure it's the same direction ?? */
pf_update_state_timeout(*stp, PFTM_PURGE);
pf_state_unref(*stp);
*stp = NULL;
pf_mbuf_link_inpcb(pd->m, inp);
return (PF_DROP);
} else if (dst->state >= TCPS_ESTABLISHED &&
src->state >= TCPS_ESTABLISHED) {
/*
* SYN matches existing state???
* Typically happens when sender boots up after
* sudden panic. Certain protocols (NFSv3) are
* always using same port numbers. Challenge
* ACK enables all parties (firewall and peers)
* to get in sync again.
*/
pf_send_challenge_ack(pd, *stp, src, dst);
return (PF_DROP);
}
}
if ((*stp)->state_flags & PFSTATE_SLOPPY) {
if (pf_tcp_track_sloppy(pd, stp, reason) == PF_DROP)
return (PF_DROP);
} else {
if (pf_tcp_track_full(pd, stp, reason, ©back,
PF_REVERSED_KEY((*stp)->key, pd->af)) == PF_DROP)
return (PF_DROP);
}
break;
case IPPROTO_UDP:
/* update states */
if (src->state < PFUDPS_SINGLE)
pf_set_protostate(*stp, psrc, PFUDPS_SINGLE);
if (dst->state == PFUDPS_SINGLE)
pf_set_protostate(*stp, pdst, PFUDPS_MULTIPLE);
/* update expire time */
(*stp)->expire = getuptime();
if (src->state == PFUDPS_MULTIPLE &&
dst->state == PFUDPS_MULTIPLE)
pf_update_state_timeout(*stp, PFTM_UDP_MULTIPLE);
else
pf_update_state_timeout(*stp, PFTM_UDP_SINGLE);
break;
default:
/* update states */
if (src->state < PFOTHERS_SINGLE)
pf_set_protostate(*stp, psrc, PFOTHERS_SINGLE);
if (dst->state == PFOTHERS_SINGLE)
pf_set_protostate(*stp, pdst, PFOTHERS_MULTIPLE);
/* update expire time */
(*stp)->expire = getuptime();
if (src->state == PFOTHERS_MULTIPLE &&
dst->state == PFOTHERS_MULTIPLE)
pf_update_state_timeout(*stp, PFTM_OTHER_MULTIPLE);
else
pf_update_state_timeout(*stp, PFTM_OTHER_SINGLE);
break;
}
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd->didx : pd->sidx;
didx = afto ? pd->sidx : pd->didx;
#ifdef INET6
if (afto) {
pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], nk->af);
pf_addrcpy(&pd->ndaddr, &nk->addr[didx], nk->af);
pd->naf = nk->af;
action = PF_AFRT;
}
#endif /* INET6 */
if (!afto)
pf_translate_a(pd, pd->src, &nk->addr[sidx]);
if (pd->sport != NULL)
pf_patch_16(pd, pd->sport, nk->port[sidx]);
if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) ||
pd->rdomain != nk->rdomain)
pd->destchg = 1;
if (!afto)
pf_translate_a(pd, pd->dst, &nk->addr[didx]);
if (pd->dport != NULL)
pf_patch_16(pd, pd->dport, nk->port[didx]);
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
copyback = 1;
}
if (copyback && pd->hdrlen > 0) {
m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
}
return (action);
}
int
pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key,
struct pf_state **stp, u_int16_t icmpid, u_int16_t type,
int icmp_dir, int *iidx, int multi, int inner)
{
int direction, action;
key->af = pd->af;
key->proto = pd->proto;
key->rdomain = pd->rdomain;
if (icmp_dir == PF_IN) {
*iidx = pd->sidx;
key->port[pd->sidx] = icmpid;
key->port[pd->didx] = type;
} else {
*iidx = pd->didx;
key->port[pd->sidx] = type;
key->port[pd->didx] = icmpid;
}
if (pf_state_key_addr_setup(pd, key, pd->sidx, pd->src, pd->didx,
pd->dst, pd->af, multi))
return (PF_DROP);
key->hash = pf_pkt_hash(key->af, key->proto,
&key->addr[0], &key->addr[1], 0, 0);
action = pf_find_state(pd, key, stp);
if (action != PF_MATCH)
return (action);
if ((*stp)->state_flags & PFSTATE_SLOPPY)
return (-1);
/* Is this ICMP message flowing in right direction? */
if ((*stp)->key[PF_SK_WIRE]->af != (*stp)->key[PF_SK_STACK]->af)
direction = (pd->af == (*stp)->key[PF_SK_WIRE]->af) ?
PF_IN : PF_OUT;
else
direction = (*stp)->direction;
if ((((!inner && direction == pd->dir) ||
(inner && direction != pd->dir)) ?
PF_IN : PF_OUT) != icmp_dir) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: icmp type %d in wrong direction (%d): ",
ntohs(type), icmp_dir);
pf_print_state(*stp);
addlog("\n");
}
return (PF_DROP);
}
return (-1);
}
int
pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **stp,
u_short *reason)
{
u_int16_t virtual_id, virtual_type;
u_int8_t icmptype, icmpcode;
int icmp_dir, iidx, ret, copyback = 0;
struct pf_state_key_cmp key;
switch (pd->proto) {
case IPPROTO_ICMP:
icmptype = pd->hdr.icmp.icmp_type;
icmpcode = pd->hdr.icmp.icmp_code;
break;
#ifdef INET6
case IPPROTO_ICMPV6:
icmptype = pd->hdr.icmp6.icmp6_type;
icmpcode = pd->hdr.icmp6.icmp6_code;
break;
#endif /* INET6 */
default:
panic("unhandled proto %d", pd->proto);
}
if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id,
&virtual_type) == 0) {
/*
* ICMP query/reply message not related to a TCP/UDP packet.
* Search for an ICMP state.
*/
ret = pf_icmp_state_lookup(pd, &key, stp,
virtual_id, virtual_type, icmp_dir, &iidx,
0, 0);
/* IPv6? try matching a multicast address */
if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT)
ret = pf_icmp_state_lookup(pd, &key, stp, virtual_id,
virtual_type, icmp_dir, &iidx, 1, 0);
if (ret >= 0)
return (ret);
(*stp)->expire = getuptime();
pf_update_state_timeout(*stp, PFTM_ICMP_ERROR_REPLY);
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd->didx : pd->sidx;
didx = afto ? pd->sidx : pd->didx;
iidx = afto ? !iidx : iidx;
#ifdef INET6
if (afto) {
pf_addrcpy(&pd->nsaddr, &nk->addr[sidx],
nk->af);
pf_addrcpy(&pd->ndaddr, &nk->addr[didx],
nk->af);
pd->naf = nk->af;
}
#endif /* INET6 */
if (!afto) {
pf_translate_a(pd, pd->src, &nk->addr[sidx]);
pf_translate_a(pd, pd->dst, &nk->addr[didx]);
}
if (pd->rdomain != nk->rdomain)
pd->destchg = 1;
if (!afto && PF_ANEQ(pd->dst,
&nk->addr[didx], pd->af))
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
switch (pd->af) {
case AF_INET:
#ifdef INET6
if (afto) {
if (pf_translate_icmp_af(pd, AF_INET6,
&pd->hdr.icmp))
return (PF_DROP);
pd->proto = IPPROTO_ICMPV6;
}
#endif /* INET6 */
pf_patch_16(pd,
&pd->hdr.icmp.icmp_id, nk->port[iidx]);
m_copyback(pd->m, pd->off, ICMP_MINLEN,
&pd->hdr.icmp, M_NOWAIT);
copyback = 1;
break;
#ifdef INET6
case AF_INET6:
if (afto) {
if (pf_translate_icmp_af(pd, AF_INET,
&pd->hdr.icmp6))
return (PF_DROP);
pd->proto = IPPROTO_ICMP;
}
pf_patch_16(pd,
&pd->hdr.icmp6.icmp6_id, nk->port[iidx]);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr), &pd->hdr.icmp6,
M_NOWAIT);
copyback = 1;
break;
#endif /* INET6 */
}
#ifdef INET6
if (afto)
return (PF_AFRT);
#endif /* INET6 */
}
} else {
/*
* ICMP error message in response to a TCP/UDP packet.
* Extract the inner TCP/UDP header and search for that state.
*/
struct pf_pdesc pd2;
struct ip h2;
#ifdef INET6
struct ip6_hdr h2_6;
#endif /* INET6 */
int ipoff2;
/* Initialize pd2 fields valid for both packets with pd. */
memset(&pd2, 0, sizeof(pd2));
pd2.af = pd->af;
pd2.dir = pd->dir;
pd2.kif = pd->kif;
pd2.m = pd->m;
pd2.rdomain = pd->rdomain;
/* Payload packet is from the opposite direction. */
pd2.sidx = (pd2.dir == PF_IN) ? 1 : 0;
pd2.didx = (pd2.dir == PF_IN) ? 0 : 1;
switch (pd->af) {
case AF_INET:
/* offset of h2 in mbuf chain */
ipoff2 = pd->off + ICMP_MINLEN;
if (!pf_pull_hdr(pd2.m, ipoff2, &h2, sizeof(h2),
reason, pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (ip)");
return (PF_DROP);
}
/*
* ICMP error messages don't refer to non-first
* fragments
*/
if (h2.ip_off & htons(IP_OFFMASK)) {
REASON_SET(reason, PFRES_FRAG);
return (PF_DROP);
}
/* offset of protocol header that follows h2 */
pd2.off = ipoff2;
if (pf_walk_header(&pd2, &h2, reason) != PF_PASS)
return (PF_DROP);
pd2.tot_len = ntohs(h2.ip_len);
pd2.src = (struct pf_addr *)&h2.ip_src;
pd2.dst = (struct pf_addr *)&h2.ip_dst;
break;
#ifdef INET6
case AF_INET6:
ipoff2 = pd->off + sizeof(struct icmp6_hdr);
if (!pf_pull_hdr(pd2.m, ipoff2, &h2_6, sizeof(h2_6),
reason, pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (ip6)");
return (PF_DROP);
}
pd2.off = ipoff2;
if (pf_walk_header6(&pd2, &h2_6, reason) != PF_PASS)
return (PF_DROP);
pd2.tot_len = ntohs(h2_6.ip6_plen) +
sizeof(struct ip6_hdr);
pd2.src = (struct pf_addr *)&h2_6.ip6_src;
pd2.dst = (struct pf_addr *)&h2_6.ip6_dst;
break;
#endif /* INET6 */
default:
unhandled_af(pd->af);
}
if (PF_ANEQ(pd->dst, pd2.src, pd->af)) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: BAD ICMP %d:%d outer dst: ",
icmptype, icmpcode);
pf_print_host(pd->src, 0, pd->af);
addlog(" -> ");
pf_print_host(pd->dst, 0, pd->af);
addlog(" inner src: ");
pf_print_host(pd2.src, 0, pd2.af);
addlog(" -> ");
pf_print_host(pd2.dst, 0, pd2.af);
addlog("\n");
}
REASON_SET(reason, PFRES_BADSTATE);
return (PF_DROP);
}
switch (pd2.proto) {
case IPPROTO_TCP: {
struct tcphdr *th = &pd2.hdr.tcp;
u_int32_t seq;
struct pf_state_peer *src, *dst;
u_int8_t dws;
int action;
/*
* Only the first 8 bytes of the TCP header can be
* expected. Don't access any TCP header fields after
* th_seq, an ackskew test is not possible.
*/
if (!pf_pull_hdr(pd2.m, pd2.off, th, 8, reason,
pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (tcp)");
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_TCP;
key.rdomain = pd2.rdomain;
pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[pd2.sidx] = th->th_sport;
key.port[pd2.didx] = th->th_dport;
key.hash = pf_pkt_hash(pd2.af, pd2.proto,
pd2.src, pd2.dst, th->th_sport, th->th_dport);
action = pf_find_state(&pd2, &key, stp);
if (action != PF_MATCH)
return (action);
if (pd2.dir == (*stp)->direction) {
if (PF_REVERSED_KEY((*stp)->key, pd->af)) {
src = &(*stp)->src;
dst = &(*stp)->dst;
} else {
src = &(*stp)->dst;
dst = &(*stp)->src;
}
} else {
if (PF_REVERSED_KEY((*stp)->key, pd->af)) {
src = &(*stp)->dst;
dst = &(*stp)->src;
} else {
src = &(*stp)->src;
dst = &(*stp)->dst;
}
}
if (src->wscale && dst->wscale)
dws = dst->wscale & PF_WSCALE_MASK;
else
dws = 0;
/* Demodulate sequence number */
seq = ntohl(th->th_seq) - src->seqdiff;
if (src->seqdiff) {
pf_patch_32(pd, &th->th_seq, htonl(seq));
copyback = 1;
}
if (!((*stp)->state_flags & PFSTATE_SLOPPY) &&
(!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq,
src->seqlo - (dst->max_win << dws)))) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: BAD ICMP %d:%d ",
icmptype, icmpcode);
pf_print_host(pd->src, 0, pd->af);
addlog(" -> ");
pf_print_host(pd->dst, 0, pd->af);
addlog(" state: ");
pf_print_state(*stp);
addlog(" seq=%u\n", seq);
}
REASON_SET(reason, PFRES_BADSTATE);
return (PF_DROP);
} else {
if (pf_status.debug >= LOG_DEBUG) {
log(LOG_DEBUG,
"pf: OK ICMP %d:%d ",
icmptype, icmpcode);
pf_print_host(pd->src, 0, pd->af);
addlog(" -> ");
pf_print_host(pd->dst, 0, pd->af);
addlog(" state: ");
pf_print_state(*stp);
addlog(" seq=%u\n", seq);
}
}
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] !=
(*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd2.didx : pd2.sidx;
didx = afto ? pd2.sidx : pd2.didx;
#ifdef INET6
if (afto) {
if (pf_translate_icmp_af(pd, nk->af,
&pd->hdr.icmp))
return (PF_DROP);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
if (pf_change_icmp_af(pd->m, ipoff2,
pd, &pd2, &nk->addr[sidx],
&nk->addr[didx], pd->af, nk->af))
return (PF_DROP);
if (nk->af == AF_INET)
pd->proto = IPPROTO_ICMP;
else
pd->proto = IPPROTO_ICMPV6;
pd->m->m_pkthdr.ph_rtableid =
nk->rdomain;
pd->destchg = 1;
pf_addrcpy(&pd->nsaddr,
&nk->addr[pd2.sidx], nk->af);
pf_addrcpy(&pd->ndaddr,
&nk->addr[pd2.didx], nk->af);
pd->naf = nk->af;
pf_patch_16(pd,
&th->th_sport, nk->port[sidx]);
pf_patch_16(pd,
&th->th_dport, nk->port[didx]);
m_copyback(pd2.m, pd2.off, 8, th,
M_NOWAIT);
return (PF_AFRT);
}
#endif /* INET6 */
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != th->th_sport)
pf_translate_icmp(pd, pd2.src,
&th->th_sport, pd->dst,
&nk->addr[pd2.sidx],
nk->port[pd2.sidx]);
if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
pd2.af) || pd2.rdomain != nk->rdomain)
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != th->th_dport)
pf_translate_icmp(pd, pd2.dst,
&th->th_dport, pd->src,
&nk->addr[pd2.didx],
nk->port[pd2.didx]);
copyback = 1;
}
if (copyback) {
switch (pd2.af) {
case AF_INET:
m_copyback(pd->m, pd->off, ICMP_MINLEN,
&pd->hdr.icmp, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2),
&h2, M_NOWAIT);
break;
#ifdef INET6
case AF_INET6:
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2_6),
&h2_6, M_NOWAIT);
break;
#endif /* INET6 */
}
m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT);
}
break;
}
case IPPROTO_UDP: {
struct udphdr *uh = &pd2.hdr.udp;
int action;
if (!pf_pull_hdr(pd2.m, pd2.off, uh, sizeof(*uh),
reason, pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (udp)");
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_UDP;
key.rdomain = pd2.rdomain;
pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[pd2.sidx] = uh->uh_sport;
key.port[pd2.didx] = uh->uh_dport;
key.hash = pf_pkt_hash(pd2.af, pd2.proto,
pd2.src, pd2.dst, uh->uh_sport, uh->uh_dport);
action = pf_find_state(&pd2, &key, stp);
if (action != PF_MATCH)
return (action);
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] !=
(*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd2.didx : pd2.sidx;
didx = afto ? pd2.sidx : pd2.didx;
#ifdef INET6
if (afto) {
if (pf_translate_icmp_af(pd, nk->af,
&pd->hdr.icmp))
return (PF_DROP);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
if (pf_change_icmp_af(pd->m, ipoff2,
pd, &pd2, &nk->addr[sidx],
&nk->addr[didx], pd->af, nk->af))
return (PF_DROP);
if (nk->af == AF_INET)
pd->proto = IPPROTO_ICMP;
else
pd->proto = IPPROTO_ICMPV6;
pd->m->m_pkthdr.ph_rtableid =
nk->rdomain;
pd->destchg = 1;
pf_addrcpy(&pd->nsaddr,
&nk->addr[pd2.sidx], nk->af);
pf_addrcpy(&pd->ndaddr,
&nk->addr[pd2.didx], nk->af);
pd->naf = nk->af;
pf_patch_16(pd,
&uh->uh_sport, nk->port[sidx]);
pf_patch_16(pd,
&uh->uh_dport, nk->port[didx]);
m_copyback(pd2.m, pd2.off, sizeof(*uh),
uh, M_NOWAIT);
return (PF_AFRT);
}
#endif /* INET6 */
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != uh->uh_sport)
pf_translate_icmp(pd, pd2.src,
&uh->uh_sport, pd->dst,
&nk->addr[pd2.sidx],
nk->port[pd2.sidx]);
if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
pd2.af) || pd2.rdomain != nk->rdomain)
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != uh->uh_dport)
pf_translate_icmp(pd, pd2.dst,
&uh->uh_dport, pd->src,
&nk->addr[pd2.didx],
nk->port[pd2.didx]);
switch (pd2.af) {
case AF_INET:
m_copyback(pd->m, pd->off, ICMP_MINLEN,
&pd->hdr.icmp, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2),
&h2, M_NOWAIT);
break;
#ifdef INET6
case AF_INET6:
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2_6),
&h2_6, M_NOWAIT);
break;
#endif /* INET6 */
}
/* Avoid recomputing quoted UDP checksum.
* note: udp6 0 csum invalid per rfc2460 p27.
* but presumed nothing cares in this context */
pf_patch_16(pd, &uh->uh_sum, 0);
m_copyback(pd2.m, pd2.off, sizeof(*uh), uh,
M_NOWAIT);
copyback = 1;
}
break;
}
case IPPROTO_ICMP: {
struct icmp *iih = &pd2.hdr.icmp;
if (pd2.af != AF_INET) {
REASON_SET(reason, PFRES_NORM);
return (PF_DROP);
}
if (!pf_pull_hdr(pd2.m, pd2.off, iih, ICMP_MINLEN,
reason, pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (icmp)");
return (PF_DROP);
}
pf_icmp_mapping(&pd2, iih->icmp_type,
&icmp_dir, &virtual_id, &virtual_type);
ret = pf_icmp_state_lookup(&pd2, &key, stp,
virtual_id, virtual_type, icmp_dir, &iidx, 0, 1);
if (ret >= 0)
return (ret);
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] !=
(*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd2.didx : pd2.sidx;
didx = afto ? pd2.sidx : pd2.didx;
iidx = afto ? !iidx : iidx;
#ifdef INET6
if (afto) {
if (nk->af != AF_INET6)
return (PF_DROP);
if (pf_translate_icmp_af(pd, nk->af,
&pd->hdr.icmp))
return (PF_DROP);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
if (pf_change_icmp_af(pd->m, ipoff2,
pd, &pd2, &nk->addr[sidx],
&nk->addr[didx], pd->af, nk->af))
return (PF_DROP);
pd->proto = IPPROTO_ICMPV6;
if (pf_translate_icmp_af(pd,
nk->af, iih))
return (PF_DROP);
if (virtual_type == htons(ICMP_ECHO))
pf_patch_16(pd, &iih->icmp_id,
nk->port[iidx]);
m_copyback(pd2.m, pd2.off, ICMP_MINLEN,
iih, M_NOWAIT);
pd->m->m_pkthdr.ph_rtableid =
nk->rdomain;
pd->destchg = 1;
pf_addrcpy(&pd->nsaddr,
&nk->addr[pd2.sidx], nk->af);
pf_addrcpy(&pd->ndaddr,
&nk->addr[pd2.didx], nk->af);
pd->naf = nk->af;
return (PF_AFRT);
}
#endif /* INET6 */
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
(virtual_type == htons(ICMP_ECHO) &&
nk->port[iidx] != iih->icmp_id))
pf_translate_icmp(pd, pd2.src,
(virtual_type == htons(ICMP_ECHO)) ?
&iih->icmp_id : NULL,
pd->dst, &nk->addr[pd2.sidx],
(virtual_type == htons(ICMP_ECHO)) ?
nk->port[iidx] : 0);
if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
pd2.af) || pd2.rdomain != nk->rdomain)
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af))
pf_translate_icmp(pd, pd2.dst, NULL,
pd->src, &nk->addr[pd2.didx], 0);
m_copyback(pd->m, pd->off, ICMP_MINLEN,
&pd->hdr.icmp, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2), &h2,
M_NOWAIT);
m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih,
M_NOWAIT);
copyback = 1;
}
break;
}
#ifdef INET6
case IPPROTO_ICMPV6: {
struct icmp6_hdr *iih = &pd2.hdr.icmp6;
if (pd2.af != AF_INET6) {
REASON_SET(reason, PFRES_NORM);
return (PF_DROP);
}
if (!pf_pull_hdr(pd2.m, pd2.off, iih,
sizeof(struct icmp6_hdr), reason, pd2.af)) {
DPFPRINTF(LOG_NOTICE,
"ICMP error message too short (icmp6)");
return (PF_DROP);
}
pf_icmp_mapping(&pd2, iih->icmp6_type,
&icmp_dir, &virtual_id, &virtual_type);
ret = pf_icmp_state_lookup(&pd2, &key, stp,
virtual_id, virtual_type, icmp_dir, &iidx, 0, 1);
/* IPv6? try matching a multicast address */
if (ret == PF_DROP && pd2.af == AF_INET6 &&
icmp_dir == PF_OUT)
ret = pf_icmp_state_lookup(&pd2, &key, stp,
virtual_id, virtual_type, icmp_dir, &iidx,
1, 1);
if (ret >= 0)
return (ret);
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] !=
(*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk;
int afto, sidx, didx;
if (PF_REVERSED_KEY((*stp)->key, pd->af))
nk = (*stp)->key[pd->sidx];
else
nk = (*stp)->key[pd->didx];
afto = pd->af != nk->af;
sidx = afto ? pd2.didx : pd2.sidx;
didx = afto ? pd2.sidx : pd2.didx;
iidx = afto ? !iidx : iidx;
if (afto) {
if (nk->af != AF_INET)
return (PF_DROP);
if (pf_translate_icmp_af(pd, nk->af,
&pd->hdr.icmp))
return (PF_DROP);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
if (pf_change_icmp_af(pd->m, ipoff2,
pd, &pd2, &nk->addr[sidx],
&nk->addr[didx], pd->af, nk->af))
return (PF_DROP);
pd->proto = IPPROTO_ICMP;
if (pf_translate_icmp_af(pd,
nk->af, iih))
return (PF_DROP);
if (virtual_type ==
htons(ICMP6_ECHO_REQUEST))
pf_patch_16(pd, &iih->icmp6_id,
nk->port[iidx]);
m_copyback(pd2.m, pd2.off,
sizeof(struct icmp6_hdr), iih,
M_NOWAIT);
pd->m->m_pkthdr.ph_rtableid =
nk->rdomain;
pd->destchg = 1;
pf_addrcpy(&pd->nsaddr,
&nk->addr[pd2.sidx], nk->af);
pf_addrcpy(&pd->ndaddr,
&nk->addr[pd2.didx], nk->af);
pd->naf = nk->af;
return (PF_AFRT);
}
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
((virtual_type ==
htons(ICMP6_ECHO_REQUEST)) &&
nk->port[pd2.sidx] != iih->icmp6_id))
pf_translate_icmp(pd, pd2.src,
(virtual_type ==
htons(ICMP6_ECHO_REQUEST))
? &iih->icmp6_id : NULL,
pd->dst, &nk->addr[pd2.sidx],
(virtual_type ==
htons(ICMP6_ECHO_REQUEST))
? nk->port[iidx] : 0);
if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
pd2.af) || pd2.rdomain != nk->rdomain)
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af))
pf_translate_icmp(pd, pd2.dst, NULL,
pd->src, &nk->addr[pd2.didx], 0);
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr), &pd->hdr.icmp6,
M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6,
M_NOWAIT);
m_copyback(pd2.m, pd2.off,
sizeof(struct icmp6_hdr), iih, M_NOWAIT);
copyback = 1;
}
break;
}
#endif /* INET6 */
default: {
int action;
key.af = pd2.af;
key.proto = pd2.proto;
key.rdomain = pd2.rdomain;
pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[0] = key.port[1] = 0;
key.hash = pf_pkt_hash(pd2.af, pd2.proto,
pd2.src, pd2.dst, 0, 0);
action = pf_find_state(&pd2, &key, stp);
if (action != PF_MATCH)
return (action);
/* translate source/destination address, if necessary */
if ((*stp)->key[PF_SK_WIRE] !=
(*stp)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*stp)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af))
pf_translate_icmp(pd, pd2.src, NULL,
pd->dst, &nk->addr[pd2.sidx], 0);
if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
pd2.af) || pd2.rdomain != nk->rdomain)
pd->destchg = 1;
pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af))
pf_translate_icmp(pd, pd2.dst, NULL,
pd->src, &nk->addr[pd2.didx], 0);
switch (pd2.af) {
case AF_INET:
m_copyback(pd->m, pd->off, ICMP_MINLEN,
&pd->hdr.icmp, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2),
&h2, M_NOWAIT);
break;
#ifdef INET6
case AF_INET6:
m_copyback(pd->m, pd->off,
sizeof(struct icmp6_hdr),
&pd->hdr.icmp6, M_NOWAIT);
m_copyback(pd2.m, ipoff2, sizeof(h2_6),
&h2_6, M_NOWAIT);
break;
#endif /* INET6 */
}
copyback = 1;
}
break;
}
}
}
if (copyback) {
m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
}
return (PF_PASS);
}
/*
* ipoff and off are measured from the start of the mbuf chain.
* h must be at "ipoff" on the mbuf chain.
*/
void *
pf_pull_hdr(struct mbuf *m, int off, void *p, int len,
u_short *reasonp, sa_family_t af)
{
int iplen = 0;
switch (af) {
case AF_INET: {
struct ip *h = mtod(m, struct ip *);
u_int16_t fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3;
if (fragoff) {
REASON_SET(reasonp, PFRES_FRAG);
return (NULL);
}
iplen = ntohs(h->ip_len);
break;
}
#ifdef INET6
case AF_INET6: {
struct ip6_hdr *h = mtod(m, struct ip6_hdr *);
iplen = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
break;
}
#endif /* INET6 */
}
if (m->m_pkthdr.len < off + len || iplen < off + len) {
REASON_SET(reasonp, PFRES_SHORT);
return (NULL);
}
m_copydata(m, off, len, p);
return (p);
}
int
pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif,
int rtableid)
{
struct sockaddr_storage ss;
struct sockaddr_in *dst;
int ret = 1;
int check_mpath;
#ifdef INET6
struct sockaddr_in6 *dst6;
#endif /* INET6 */
struct rtentry *rt = NULL;
check_mpath = 0;
memset(&ss, 0, sizeof(ss));
switch (af) {
case AF_INET:
dst = (struct sockaddr_in *)&ss;
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = addr->v4;
if (ipmultipath)
check_mpath = 1;
break;
#ifdef INET6
case AF_INET6:
/*
* Skip check for addresses with embedded interface scope,
* as they would always match anyway.
*/
if (IN6_IS_SCOPE_EMBED(&addr->v6))
goto out;
dst6 = (struct sockaddr_in6 *)&ss;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = addr->v6;
if (ip6_multipath)
check_mpath = 1;
break;
#endif /* INET6 */
}
/* Skip checks for ipsec interfaces */
if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC)
goto out;
rt = rtalloc(sstosa(&ss), 0, rtableid);
if (rt != NULL) {
/* No interface given, this is a no-route check */
if (kif == NULL)
goto out;
if (kif->pfik_ifp == NULL) {
ret = 0;
goto out;
}
/* Perform uRPF check if passed input interface */
ret = 0;
do {
if (rt->rt_ifidx == kif->pfik_ifp->if_index) {
ret = 1;
#if NCARP > 0
} else {
struct ifnet *ifp;
ifp = if_get(rt->rt_ifidx);
if (ifp != NULL && ifp->if_type == IFT_CARP &&
ifp->if_carpdevidx ==
kif->pfik_ifp->if_index)
ret = 1;
if_put(ifp);
#endif /* NCARP */
}
rt = rtable_iterate(rt);
} while (check_mpath == 1 && rt != NULL && ret == 0);
} else
ret = 0;
out:
rtfree(rt);
return (ret);
}
int
pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw,
int rtableid)
{
struct sockaddr_storage ss;
struct sockaddr_in *dst;
#ifdef INET6
struct sockaddr_in6 *dst6;
#endif /* INET6 */
struct rtentry *rt;
int ret = 0;
memset(&ss, 0, sizeof(ss));
switch (af) {
case AF_INET:
dst = (struct sockaddr_in *)&ss;
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = addr->v4;
break;
#ifdef INET6
case AF_INET6:
dst6 = (struct sockaddr_in6 *)&ss;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = addr->v6;
break;
#endif /* INET6 */
}
rt = rtalloc(sstosa(&ss), RT_RESOLVE, rtableid);
if (rt != NULL) {
if (rt->rt_labelid == aw->v.rtlabel)
ret = 1;
rtfree(rt);
}
return (ret);
}
/* pf_route() may change pd->m, adjust local copies after calling */
void
pf_route(struct pf_pdesc *pd, struct pf_state *st)
{
struct mbuf *m0;
struct mbuf_list ml;
struct sockaddr_in *dst, sin;
struct rtentry *rt = NULL;
struct ip *ip;
struct ifnet *ifp = NULL;
unsigned int rtableid;
if (pd->m->m_pkthdr.pf.routed++ > 3) {
m_freem(pd->m);
pd->m = NULL;
return;
}
if (st->rt == PF_DUPTO) {
if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL)
return;
} else {
if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir))
return;
m0 = pd->m;
pd->m = NULL;
}
if (m0->m_len < sizeof(struct ip)) {
DPFPRINTF(LOG_ERR,
"%s: m0->m_len < sizeof(struct ip)", __func__);
goto bad;
}
ip = mtod(m0, struct ip *);
if (pd->dir == PF_IN) {
if (ip->ip_ttl <= IPTTLDEC) {
if (st->rt != PF_DUPTO) {
pf_send_icmp(m0, ICMP_TIMXCEED,
ICMP_TIMXCEED_INTRANS, 0,
pd->af, st->rule.ptr, pd->rdomain);
}
goto bad;
}
ip->ip_ttl -= IPTTLDEC;
}
memset(&sin, 0, sizeof(sin));
dst = &sin;
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = st->rt_addr.v4;
rtableid = m0->m_pkthdr.ph_rtableid;
rt = rtalloc_mpath(sintosa(dst), &ip->ip_src.s_addr, rtableid);
if (!rtisvalid(rt)) {
if (st->rt != PF_DUPTO) {
pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_HOST,
0, pd->af, st->rule.ptr, pd->rdomain);
}
ipstat_inc(ips_noroute);
goto bad;
}
ifp = if_get(rt->rt_ifidx);
if (ifp == NULL)
goto bad;
/* A locally generated packet may have invalid source address. */
if ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET &&
(ifp->if_flags & IFF_LOOPBACK) == 0)
ip->ip_src = ifatoia(rt->rt_ifa)->ia_addr.sin_addr;
if (st->rt != PF_DUPTO && pd->dir == PF_IN) {
if (pf_test(AF_INET, PF_OUT, ifp, &m0) != PF_PASS)
goto bad;
else if (m0 == NULL)
goto done;
if (m0->m_len < sizeof(struct ip)) {
DPFPRINTF(LOG_ERR,
"%s: m0->m_len < sizeof(struct ip)", __func__);
goto bad;
}
ip = mtod(m0, struct ip *);
}
if (if_output_tso(ifp, &m0, sintosa(dst), rt, ifp->if_mtu) ||
m0 == NULL)
goto done;
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
if (ip->ip_off & htons(IP_DF)) {
ipstat_inc(ips_cantfrag);
if (st->rt != PF_DUPTO)
pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG,
ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain);
goto bad;
}
if (ip_fragment(m0, &ml, ifp, ifp->if_mtu) ||
if_output_ml(ifp, &ml, sintosa(dst), rt))
goto done;
ipstat_inc(ips_fragmented);
done:
if_put(ifp);
rtfree(rt);
return;
bad:
m_freem(m0);
goto done;
}
#ifdef INET6
/* pf_route6() may change pd->m, adjust local copies after calling */
void
pf_route6(struct pf_pdesc *pd, struct pf_state *st)
{
struct mbuf *m0;
struct sockaddr_in6 *dst, sin6;
struct rtentry *rt = NULL;
struct ip6_hdr *ip6;
struct ifnet *ifp = NULL;
struct m_tag *mtag;
unsigned int rtableid;
if (pd->m->m_pkthdr.pf.routed++ > 3) {
m_freem(pd->m);
pd->m = NULL;
return;
}
if (st->rt == PF_DUPTO) {
if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL)
return;
} else {
if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir))
return;
m0 = pd->m;
pd->m = NULL;
}
if (m0->m_len < sizeof(struct ip6_hdr)) {
DPFPRINTF(LOG_ERR,
"%s: m0->m_len < sizeof(struct ip6_hdr)", __func__);
goto bad;
}
ip6 = mtod(m0, struct ip6_hdr *);
if (pd->dir == PF_IN) {
if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
if (st->rt != PF_DUPTO) {
pf_send_icmp(m0, ICMP6_TIME_EXCEEDED,
ICMP6_TIME_EXCEED_TRANSIT, 0,
pd->af, st->rule.ptr, pd->rdomain);
}
goto bad;
}
ip6->ip6_hlim -= IPV6_HLIMDEC;
}
memset(&sin6, 0, sizeof(sin6));
dst = &sin6;
dst->sin6_family = AF_INET6;
dst->sin6_len = sizeof(*dst);
dst->sin6_addr = st->rt_addr.v6;
rtableid = m0->m_pkthdr.ph_rtableid;
rt = rtalloc_mpath(sin6tosa(dst), &ip6->ip6_src.s6_addr32[0],
rtableid);
if (!rtisvalid(rt)) {
if (st->rt != PF_DUPTO) {
pf_send_icmp(m0, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_NOROUTE, 0,
pd->af, st->rule.ptr, pd->rdomain);
}
ip6stat_inc(ip6s_noroute);
goto bad;
}
ifp = if_get(rt->rt_ifidx);
if (ifp == NULL)
goto bad;
/* A locally generated packet may have invalid source address. */
if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
(ifp->if_flags & IFF_LOOPBACK) == 0)
ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
if (st->rt != PF_DUPTO && pd->dir == PF_IN) {
if (pf_test(AF_INET6, PF_OUT, ifp, &m0) != PF_PASS)
goto bad;
else if (m0 == NULL)
goto done;
if (m0->m_len < sizeof(struct ip6_hdr)) {
DPFPRINTF(LOG_ERR,
"%s: m0->m_len < sizeof(struct ip6_hdr)", __func__);
goto bad;
}
}
/*
* If packet has been reassembled by PF earlier, we have to
* use pf_refragment6() here to turn it back to fragments.
*/
if ((mtag = m_tag_find(m0, PACKET_TAG_PF_REASSEMBLED, NULL))) {
(void) pf_refragment6(&m0, mtag, dst, ifp, rt);
goto done;
}
if (if_output_tso(ifp, &m0, sin6tosa(dst), rt, ifp->if_mtu) ||
m0 == NULL)
goto done;
ip6stat_inc(ip6s_cantfrag);
if (st->rt != PF_DUPTO)
pf_send_icmp(m0, ICMP6_PACKET_TOO_BIG, 0,
ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain);
goto bad;
done:
if_put(ifp);
rtfree(rt);
return;
bad:
m_freem(m0);
goto done;
}
#endif /* INET6 */
/*
* check TCP checksum and set mbuf flag
* off is the offset where the protocol header starts
* len is the total length of protocol header plus payload
* returns 0 when the checksum is valid, otherwise returns 1.
* if the _OUT flag is set the checksum isn't done yet, consider these ok
*/
int
pf_check_tcp_cksum(struct mbuf *m, int off, int len, sa_family_t af)
{
u_int16_t sum;
if (m->m_pkthdr.csum_flags &
(M_TCP_CSUM_IN_OK | M_TCP_CSUM_OUT)) {
return (0);
}
if (m->m_pkthdr.csum_flags & M_TCP_CSUM_IN_BAD ||
off < sizeof(struct ip) ||
m->m_pkthdr.len < off + len) {
return (1);
}
/* need to do it in software */
tcpstat_inc(tcps_inswcsum);
switch (af) {
case AF_INET:
if (m->m_len < sizeof(struct ip))
return (1);
sum = in4_cksum(m, IPPROTO_TCP, off, len);
break;
#ifdef INET6
case AF_INET6:
if (m->m_len < sizeof(struct ip6_hdr))
return (1);
sum = in6_cksum(m, IPPROTO_TCP, off, len);
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
if (sum) {
tcpstat_inc(tcps_rcvbadsum);
m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD;
return (1);
}
m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK;
return (0);
}
struct pf_divert *
pf_find_divert(struct mbuf *m)
{
struct m_tag *mtag;
if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL)
return (NULL);
return ((struct pf_divert *)(mtag + 1));
}
struct pf_divert *
pf_get_divert(struct mbuf *m)
{
struct m_tag *mtag;
if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) {
mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert),
M_NOWAIT);
if (mtag == NULL)
return (NULL);
memset(mtag + 1, 0, sizeof(struct pf_divert));
m_tag_prepend(m, mtag);
}
return ((struct pf_divert *)(mtag + 1));
}
int
pf_walk_option(struct pf_pdesc *pd, struct ip *h, int off, int end,
u_short *reason)
{
uint8_t type, length, opts[15 * 4 - sizeof(struct ip)];
/* IP header in payload of ICMP packet may be too short */
if (pd->m->m_pkthdr.len < end) {
DPFPRINTF(LOG_NOTICE, "IP option too short");
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
KASSERT(end - off <= sizeof(opts));
m_copydata(pd->m, off, end - off, opts);
end -= off;
off = 0;
while (off < end) {
type = opts[off];
if (type == IPOPT_EOL)
break;
if (type == IPOPT_NOP) {
off++;
continue;
}
if (off + 2 > end) {
DPFPRINTF(LOG_NOTICE, "IP length opt");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
length = opts[off + 1];
if (length < 2) {
DPFPRINTF(LOG_NOTICE, "IP short opt");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
if (off + length > end) {
DPFPRINTF(LOG_NOTICE, "IP long opt");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
switch (type) {
case IPOPT_RA:
SET(pd->badopts, PF_OPT_ROUTER_ALERT);
break;
default:
SET(pd->badopts, PF_OPT_OTHER);
break;
}
off += length;
}
return (PF_PASS);
}
int
pf_walk_header(struct pf_pdesc *pd, struct ip *h, u_short *reason)
{
struct ip6_ext ext;
u_int32_t hlen, end;
int hdr_cnt;
hlen = h->ip_hl << 2;
if (hlen < sizeof(struct ip) || hlen > ntohs(h->ip_len)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
if (hlen != sizeof(struct ip)) {
if (pf_walk_option(pd, h, pd->off + sizeof(struct ip),
pd->off + hlen, reason) != PF_PASS)
return (PF_DROP);
/* header options which contain only padding is fishy */
if (pd->badopts == 0)
SET(pd->badopts, PF_OPT_OTHER);
}
end = pd->off + ntohs(h->ip_len);
pd->off += hlen;
pd->proto = h->ip_p;
/* IGMP packets have router alert options, allow them */
if (pd->proto == IPPROTO_IGMP) {
/*
* According to RFC 1112 ttl must be set to 1 in all IGMP
* packets sent to 224.0.0.1
*/
if ((h->ip_ttl != 1) &&
(h->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP)) {
DPFPRINTF(LOG_NOTICE, "Invalid IGMP");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
CLR(pd->badopts, PF_OPT_ROUTER_ALERT);
}
/* stop walking over non initial fragments */
if ((h->ip_off & htons(IP_OFFMASK)) != 0)
return (PF_PASS);
for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) {
switch (pd->proto) {
case IPPROTO_AH:
/* fragments may be short */
if ((h->ip_off & htons(IP_MF | IP_OFFMASK)) != 0 &&
end < pd->off + sizeof(ext))
return (PF_PASS);
if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
reason, AF_INET)) {
DPFPRINTF(LOG_NOTICE, "IP short exthdr");
return (PF_DROP);
}
pd->off += (ext.ip6e_len + 2) * 4;
pd->proto = ext.ip6e_nxt;
break;
default:
return (PF_PASS);
}
}
DPFPRINTF(LOG_NOTICE, "IPv4 nested authentication header limit");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
#ifdef INET6
int
pf_walk_option6(struct pf_pdesc *pd, struct ip6_hdr *h, int off, int end,
u_short *reason)
{
struct ip6_opt opt;
struct ip6_opt_jumbo jumbo;
while (off < end) {
if (!pf_pull_hdr(pd->m, off, &opt.ip6o_type,
sizeof(opt.ip6o_type), reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short opt type");
return (PF_DROP);
}
if (opt.ip6o_type == IP6OPT_PAD1) {
off++;
continue;
}
if (!pf_pull_hdr(pd->m, off, &opt, sizeof(opt),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short opt");
return (PF_DROP);
}
if (off + sizeof(opt) + opt.ip6o_len > end) {
DPFPRINTF(LOG_NOTICE, "IPv6 long opt");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
switch (opt.ip6o_type) {
case IP6OPT_PADN:
break;
case IP6OPT_JUMBO:
SET(pd->badopts, PF_OPT_JUMBO);
if (pd->jumbolen != 0) {
DPFPRINTF(LOG_NOTICE, "IPv6 multiple jumbo");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
if (ntohs(h->ip6_plen) != 0) {
DPFPRINTF(LOG_NOTICE, "IPv6 bad jumbo plen");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
if (!pf_pull_hdr(pd->m, off, &jumbo, sizeof(jumbo),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short jumbo");
return (PF_DROP);
}
memcpy(&pd->jumbolen, jumbo.ip6oj_jumbo_len,
sizeof(pd->jumbolen));
pd->jumbolen = ntohl(pd->jumbolen);
if (pd->jumbolen < IPV6_MAXPACKET) {
DPFPRINTF(LOG_NOTICE, "IPv6 short jumbolen");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
break;
case IP6OPT_ROUTER_ALERT:
SET(pd->badopts, PF_OPT_ROUTER_ALERT);
break;
default:
SET(pd->badopts, PF_OPT_OTHER);
break;
}
off += sizeof(opt) + opt.ip6o_len;
}
return (PF_PASS);
}
int
pf_walk_header6(struct pf_pdesc *pd, struct ip6_hdr *h, u_short *reason)
{
struct ip6_frag frag;
struct ip6_ext ext;
struct icmp6_hdr icmp6;
struct ip6_rthdr rthdr;
u_int32_t end;
int hdr_cnt, fraghdr_cnt = 0, rthdr_cnt = 0;
pd->off += sizeof(struct ip6_hdr);
end = pd->off + ntohs(h->ip6_plen);
pd->fragoff = pd->extoff = pd->jumbolen = 0;
pd->proto = h->ip6_nxt;
for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) {
switch (pd->proto) {
case IPPROTO_ROUTING:
case IPPROTO_DSTOPTS:
SET(pd->badopts, PF_OPT_OTHER);
break;
case IPPROTO_HOPOPTS:
if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr");
return (PF_DROP);
}
if (pf_walk_option6(pd, h, pd->off + sizeof(ext),
pd->off + (ext.ip6e_len + 1) * 8, reason)
!= PF_PASS)
return (PF_DROP);
/* option header which contains only padding is fishy */
if (pd->badopts == 0)
SET(pd->badopts, PF_OPT_OTHER);
break;
}
switch (pd->proto) {
case IPPROTO_FRAGMENT:
if (fraghdr_cnt++) {
DPFPRINTF(LOG_NOTICE, "IPv6 multiple fragment");
REASON_SET(reason, PFRES_FRAG);
return (PF_DROP);
}
/* jumbo payload packets cannot be fragmented */
if (pd->jumbolen != 0) {
DPFPRINTF(LOG_NOTICE, "IPv6 fragmented jumbo");
REASON_SET(reason, PFRES_FRAG);
return (PF_DROP);
}
if (!pf_pull_hdr(pd->m, pd->off, &frag, sizeof(frag),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short fragment");
return (PF_DROP);
}
/* stop walking over non initial fragments */
if (ntohs((frag.ip6f_offlg & IP6F_OFF_MASK)) != 0) {
pd->fragoff = pd->off;
return (PF_PASS);
}
/* RFC6946: reassemble only non atomic fragments */
if (frag.ip6f_offlg & IP6F_MORE_FRAG)
pd->fragoff = pd->off;
pd->off += sizeof(frag);
pd->proto = frag.ip6f_nxt;
break;
case IPPROTO_ROUTING:
if (rthdr_cnt++) {
DPFPRINTF(LOG_NOTICE, "IPv6 multiple rthdr");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
/* fragments may be short */
if (pd->fragoff != 0 && end < pd->off + sizeof(rthdr)) {
pd->off = pd->fragoff;
pd->proto = IPPROTO_FRAGMENT;
return (PF_PASS);
}
if (!pf_pull_hdr(pd->m, pd->off, &rthdr, sizeof(rthdr),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short rthdr");
return (PF_DROP);
}
if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) {
DPFPRINTF(LOG_NOTICE, "IPv6 rthdr0");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
/* FALLTHROUGH */
case IPPROTO_HOPOPTS:
/* RFC2460 4.1: Hop-by-Hop only after IPv6 header */
if (pd->proto == IPPROTO_HOPOPTS && hdr_cnt > 0) {
DPFPRINTF(LOG_NOTICE, "IPv6 hopopts not first");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
/* FALLTHROUGH */
case IPPROTO_AH:
case IPPROTO_DSTOPTS:
/* fragments may be short */
if (pd->fragoff != 0 && end < pd->off + sizeof(ext)) {
pd->off = pd->fragoff;
pd->proto = IPPROTO_FRAGMENT;
return (PF_PASS);
}
if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr");
return (PF_DROP);
}
/* reassembly needs the ext header before the frag */
if (pd->fragoff == 0)
pd->extoff = pd->off;
if (pd->proto == IPPROTO_HOPOPTS && pd->fragoff == 0 &&
ntohs(h->ip6_plen) == 0 && pd->jumbolen != 0) {
DPFPRINTF(LOG_NOTICE, "IPv6 missing jumbo");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
if (pd->proto == IPPROTO_AH)
pd->off += (ext.ip6e_len + 2) * 4;
else
pd->off += (ext.ip6e_len + 1) * 8;
pd->proto = ext.ip6e_nxt;
break;
case IPPROTO_ICMPV6:
/* fragments may be short, ignore inner header then */
if (pd->fragoff != 0 && end < pd->off + sizeof(icmp6)) {
pd->off = pd->fragoff;
pd->proto = IPPROTO_FRAGMENT;
return (PF_PASS);
}
if (!pf_pull_hdr(pd->m, pd->off, &icmp6, sizeof(icmp6),
reason, AF_INET6)) {
DPFPRINTF(LOG_NOTICE, "IPv6 short icmp6hdr");
return (PF_DROP);
}
/* ICMP multicast packets have router alert options */
switch (icmp6.icmp6_type) {
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
case MLD_LISTENER_DONE:
case MLDV2_LISTENER_REPORT:
/*
* According to RFC 2710 all MLD messages are
* sent with hop-limit (ttl) set to 1, and link
* local source address. If either one is
* missing then MLD message is invalid and
* should be discarded.
*/
if ((h->ip6_hlim != 1) ||
!IN6_IS_ADDR_LINKLOCAL(&h->ip6_src)) {
DPFPRINTF(LOG_NOTICE, "Invalid MLD");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
CLR(pd->badopts, PF_OPT_ROUTER_ALERT);
break;
}
return (PF_PASS);
case IPPROTO_TCP:
case IPPROTO_UDP:
/* fragments may be short, ignore inner header then */
if (pd->fragoff != 0 && end < pd->off +
(pd->proto == IPPROTO_TCP ? sizeof(struct tcphdr) :
pd->proto == IPPROTO_UDP ? sizeof(struct udphdr) :
sizeof(struct icmp6_hdr))) {
pd->off = pd->fragoff;
pd->proto = IPPROTO_FRAGMENT;
}
/* FALLTHROUGH */
default:
return (PF_PASS);
}
}
DPFPRINTF(LOG_NOTICE, "IPv6 nested extension header limit");
REASON_SET(reason, PFRES_IPOPTIONS);
return (PF_DROP);
}
#endif /* INET6 */
u_int16_t
pf_pkt_hash(sa_family_t af, uint8_t proto,
const struct pf_addr *src, const struct pf_addr *dst,
uint16_t sport, uint16_t dport)
{
uint32_t hash;
hash = src->addr32[0] ^ dst->addr32[0];
#ifdef INET6
if (af == AF_INET6) {
hash ^= src->addr32[1] ^ dst->addr32[1];
hash ^= src->addr32[2] ^ dst->addr32[2];
hash ^= src->addr32[3] ^ dst->addr32[3];
}
#endif
switch (proto) {
case IPPROTO_TCP:
case IPPROTO_UDP:
hash ^= sport ^ dport;
break;
}
return stoeplitz_n32(hash);
}
int
pf_setup_pdesc(struct pf_pdesc *pd, sa_family_t af, int dir,
struct pfi_kif *kif, struct mbuf *m, u_short *reason)
{
memset(pd, 0, sizeof(*pd));
pd->dir = dir;
pd->kif = kif; /* kif is NULL when called by pflog */
pd->m = m;
pd->sidx = (dir == PF_IN) ? 0 : 1;
pd->didx = (dir == PF_IN) ? 1 : 0;
pd->af = pd->naf = af;
pd->rdomain = rtable_l2(pd->m->m_pkthdr.ph_rtableid);
switch (pd->af) {
case AF_INET: {
struct ip *h;
/* Check for illegal packets */
if (pd->m->m_pkthdr.len < (int)sizeof(struct ip)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
h = mtod(pd->m, struct ip *);
if (pd->m->m_pkthdr.len < ntohs(h->ip_len)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
if (pf_walk_header(pd, h, reason) != PF_PASS)
return (PF_DROP);
pd->src = (struct pf_addr *)&h->ip_src;
pd->dst = (struct pf_addr *)&h->ip_dst;
pd->tot_len = ntohs(h->ip_len);
pd->tos = h->ip_tos & ~IPTOS_ECN_MASK;
pd->ttl = h->ip_ttl;
pd->virtual_proto = (h->ip_off & htons(IP_MF | IP_OFFMASK)) ?
PF_VPROTO_FRAGMENT : pd->proto;
break;
}
#ifdef INET6
case AF_INET6: {
struct ip6_hdr *h;
/* Check for illegal packets */
if (pd->m->m_pkthdr.len < (int)sizeof(struct ip6_hdr)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
h = mtod(pd->m, struct ip6_hdr *);
if (pd->m->m_pkthdr.len <
sizeof(struct ip6_hdr) + ntohs(h->ip6_plen)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
if (pf_walk_header6(pd, h, reason) != PF_PASS)
return (PF_DROP);
#if 1
/*
* we do not support jumbogram yet. if we keep going, zero
* ip6_plen will do something bad, so drop the packet for now.
*/
if (pd->jumbolen != 0) {
REASON_SET(reason, PFRES_NORM);
return (PF_DROP);
}
#endif /* 1 */
pd->src = (struct pf_addr *)&h->ip6_src;
pd->dst = (struct pf_addr *)&h->ip6_dst;
pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20;
pd->ttl = h->ip6_hlim;
pd->virtual_proto = (pd->fragoff != 0) ?
PF_VPROTO_FRAGMENT : pd->proto;
break;
}
#endif /* INET6 */
default:
panic("pf_setup_pdesc called with illegal af %u", pd->af);
}
pf_addrcpy(&pd->nsaddr, pd->src, pd->af);
pf_addrcpy(&pd->ndaddr, pd->dst, pd->af);
switch (pd->virtual_proto) {
case IPPROTO_TCP: {
struct tcphdr *th = &pd->hdr.tcp;
if (!pf_pull_hdr(pd->m, pd->off, th, sizeof(*th),
reason, pd->af))
return (PF_DROP);
pd->hdrlen = sizeof(*th);
if (th->th_dport == 0 ||
pd->off + (th->th_off << 2) > pd->tot_len ||
(th->th_off << 2) < sizeof(struct tcphdr)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
pd->p_len = pd->tot_len - pd->off - (th->th_off << 2);
pd->sport = &th->th_sport;
pd->dport = &th->th_dport;
pd->pcksum = &th->th_sum;
break;
}
case IPPROTO_UDP: {
struct udphdr *uh = &pd->hdr.udp;
if (!pf_pull_hdr(pd->m, pd->off, uh, sizeof(*uh),
reason, pd->af))
return (PF_DROP);
pd->hdrlen = sizeof(*uh);
if (uh->uh_dport == 0 ||
pd->off + ntohs(uh->uh_ulen) > pd->tot_len ||
ntohs(uh->uh_ulen) < sizeof(struct udphdr)) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
pd->sport = &uh->uh_sport;
pd->dport = &uh->uh_dport;
pd->pcksum = &uh->uh_sum;
break;
}
case IPPROTO_ICMP: {
if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp, ICMP_MINLEN,
reason, pd->af))
return (PF_DROP);
pd->hdrlen = ICMP_MINLEN;
if (pd->off + pd->hdrlen > pd->tot_len) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
pd->pcksum = &pd->hdr.icmp.icmp_cksum;
break;
}
#ifdef INET6
case IPPROTO_ICMPV6: {
size_t icmp_hlen = sizeof(struct icmp6_hdr);
if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen,
reason, pd->af))
return (PF_DROP);
/* ICMP headers we look further into to match state */
switch (pd->hdr.icmp6.icmp6_type) {
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
icmp_hlen = sizeof(struct mld_hdr);
break;
case ND_NEIGHBOR_SOLICIT:
case ND_NEIGHBOR_ADVERT:
icmp_hlen = sizeof(struct nd_neighbor_solicit);
/* FALLTHROUGH */
case ND_ROUTER_SOLICIT:
case ND_ROUTER_ADVERT:
case ND_REDIRECT:
if (pd->ttl != 255) {
REASON_SET(reason, PFRES_NORM);
return (PF_DROP);
}
break;
}
if (icmp_hlen > sizeof(struct icmp6_hdr) &&
!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen,
reason, pd->af))
return (PF_DROP);
pd->hdrlen = icmp_hlen;
if (pd->off + pd->hdrlen > pd->tot_len) {
REASON_SET(reason, PFRES_SHORT);
return (PF_DROP);
}
pd->pcksum = &pd->hdr.icmp6.icmp6_cksum;
break;
}
#endif /* INET6 */
}
if (pd->sport)
pd->osport = pd->nsport = *pd->sport;
if (pd->dport)
pd->odport = pd->ndport = *pd->dport;
pd->hash = pf_pkt_hash(pd->af, pd->proto,
pd->src, pd->dst, pd->osport, pd->odport);
return (PF_PASS);
}
void
pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *st,
struct pf_rule *r, struct pf_rule *a)
{
int dirndx;
pd->kif->pfik_bytes[pd->af == AF_INET6][pd->dir == PF_OUT]
[action != PF_PASS] += pd->tot_len;
pd->kif->pfik_packets[pd->af == AF_INET6][pd->dir == PF_OUT]
[action != PF_PASS]++;
if (action == PF_PASS || action == PF_AFRT || r->action == PF_DROP) {
dirndx = (pd->dir == PF_OUT);
r->packets[dirndx]++;
r->bytes[dirndx] += pd->tot_len;
if (a != NULL) {
a->packets[dirndx]++;
a->bytes[dirndx] += pd->tot_len;
}
if (st != NULL) {
struct pf_rule_item *ri;
struct pf_sn_item *sni;
SLIST_FOREACH(sni, &st->src_nodes, next) {
sni->sn->packets[dirndx]++;
sni->sn->bytes[dirndx] += pd->tot_len;
}
dirndx = (pd->dir == st->direction) ? 0 : 1;
st->packets[dirndx]++;
st->bytes[dirndx] += pd->tot_len;
SLIST_FOREACH(ri, &st->match_rules, entry) {
ri->r->packets[dirndx]++;
ri->r->bytes[dirndx] += pd->tot_len;
if (ri->r->src.addr.type == PF_ADDR_TABLE)
pfr_update_stats(ri->r->src.addr.p.tbl,
&st->key[(st->direction == PF_IN)]->
addr[(st->direction == PF_OUT)],
pd, ri->r->action, ri->r->src.neg);
if (ri->r->dst.addr.type == PF_ADDR_TABLE)
pfr_update_stats(ri->r->dst.addr.p.tbl,
&st->key[(st->direction == PF_IN)]->
addr[(st->direction == PF_IN)],
pd, ri->r->action, ri->r->dst.neg);
}
}
if (r->src.addr.type == PF_ADDR_TABLE)
pfr_update_stats(r->src.addr.p.tbl,
(st == NULL) ? pd->src :
&st->key[(st->direction == PF_IN)]->
addr[(st->direction == PF_OUT)],
pd, r->action, r->src.neg);
if (r->dst.addr.type == PF_ADDR_TABLE)
pfr_update_stats(r->dst.addr.p.tbl,
(st == NULL) ? pd->dst :
&st->key[(st->direction == PF_IN)]->
addr[(st->direction == PF_IN)],
pd, r->action, r->dst.neg);
}
}
int
pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0)
{
#if NCARP > 0
struct ifnet *ifp0;
#endif
struct pfi_kif *kif;
u_short action, reason = 0;
struct pf_rule *a = NULL, *r = &pf_default_rule;
struct pf_state *st = NULL;
struct pf_state_key_cmp key;
struct pf_ruleset *ruleset = NULL;
struct pf_pdesc pd;
int dir = (fwdir == PF_FWD) ? PF_OUT : fwdir;
u_int32_t qid, pqid = 0;
int have_pf_lock = 0;
if (!pf_status.running)
return (PF_PASS);
#if NCARP > 0
if (ifp->if_type == IFT_CARP &&
(ifp0 = if_get(ifp->if_carpdevidx)) != NULL) {
kif = (struct pfi_kif *)ifp0->if_pf_kif;
if_put(ifp0);
} else
#endif /* NCARP */
kif = (struct pfi_kif *)ifp->if_pf_kif;
if (kif == NULL) {
DPFPRINTF(LOG_ERR,
"%s: kif == NULL, if_xname %s", __func__, ifp->if_xname);
return (PF_DROP);
}
if (kif->pfik_flags & PFI_IFLAG_SKIP)
return (PF_PASS);
#ifdef DIAGNOSTIC
if (((*m0)->m_flags & M_PKTHDR) == 0)
panic("non-M_PKTHDR is passed to pf_test");
#endif /* DIAGNOSTIC */
if ((*m0)->m_pkthdr.pf.flags & PF_TAG_GENERATED)
return (PF_PASS);
if ((*m0)->m_pkthdr.pf.flags & PF_TAG_DIVERTED_PACKET) {
(*m0)->m_pkthdr.pf.flags &= ~PF_TAG_DIVERTED_PACKET;
return (PF_PASS);
}
if ((*m0)->m_pkthdr.pf.flags & PF_TAG_REFRAGMENTED) {
(*m0)->m_pkthdr.pf.flags &= ~PF_TAG_REFRAGMENTED;
return (PF_PASS);
}
action = pf_setup_pdesc(&pd, af, dir, kif, *m0, &reason);
if (action != PF_PASS) {
#if NPFLOG > 0
pd.pflog |= PF_LOG_FORCE;
#endif /* NPFLOG > 0 */
goto done;
}
/* packet normalization and reassembly */
switch (pd.af) {
case AF_INET:
action = pf_normalize_ip(&pd, &reason);
break;
#ifdef INET6
case AF_INET6:
action = pf_normalize_ip6(&pd, &reason);
break;
#endif /* INET6 */
}
*m0 = pd.m;
/* if packet sits in reassembly queue, return without error */
if (pd.m == NULL)
return PF_PASS;
if (action != PF_PASS) {
#if NPFLOG > 0
pd.pflog |= PF_LOG_FORCE;
#endif /* NPFLOG > 0 */
goto done;
}
/* if packet has been reassembled, update packet description */
if (pf_status.reass && pd.virtual_proto == PF_VPROTO_FRAGMENT) {
action = pf_setup_pdesc(&pd, af, dir, kif, pd.m, &reason);
if (action != PF_PASS) {
#if NPFLOG > 0
pd.pflog |= PF_LOG_FORCE;
#endif /* NPFLOG > 0 */
goto done;
}
}
pd.m->m_pkthdr.pf.flags |= PF_TAG_PROCESSED;
/*
* Avoid pcb-lookups from the forwarding path. They should never
* match and would cause MP locking problems.
*/
if (fwdir == PF_FWD) {
pd.lookup.done = -1;
pd.lookup.uid = -1;
pd.lookup.gid = -1;
pd.lookup.pid = NO_PID;
}
switch (pd.virtual_proto) {
case PF_VPROTO_FRAGMENT: {
/*
* handle fragments that aren't reassembled by
* normalization
*/
PF_LOCK();
have_pf_lock = 1;
action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason);
st = pf_state_ref(st);
if (action != PF_PASS)
REASON_SET(&reason, PFRES_FRAG);
break;
}
case IPPROTO_ICMP: {
if (pd.af != AF_INET) {
action = PF_DROP;
REASON_SET(&reason, PFRES_NORM);
DPFPRINTF(LOG_NOTICE,
"dropping IPv6 packet with ICMPv4 payload");
break;
}
PF_STATE_ENTER_READ();
action = pf_test_state_icmp(&pd, &st, &reason);
st = pf_state_ref(st);
PF_STATE_EXIT_READ();
if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
r = st->rule.ptr;
a = st->anchor.ptr;
#if NPFLOG > 0
pd.pflog |= st->log;
#endif /* NPFLOG > 0 */
} else if (st == NULL) {
PF_LOCK();
have_pf_lock = 1;
action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
&reason);
st = pf_state_ref(st);
}
break;
}
#ifdef INET6
case IPPROTO_ICMPV6: {
if (pd.af != AF_INET6) {
action = PF_DROP;
REASON_SET(&reason, PFRES_NORM);
DPFPRINTF(LOG_NOTICE,
"dropping IPv4 packet with ICMPv6 payload");
break;
}
PF_STATE_ENTER_READ();
action = pf_test_state_icmp(&pd, &st, &reason);
st = pf_state_ref(st);
PF_STATE_EXIT_READ();
if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
r = st->rule.ptr;
a = st->anchor.ptr;
#if NPFLOG > 0
pd.pflog |= st->log;
#endif /* NPFLOG > 0 */
} else if (st == NULL) {
PF_LOCK();
have_pf_lock = 1;
action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
&reason);
st = pf_state_ref(st);
}
break;
}
#endif /* INET6 */
default:
if (pd.virtual_proto == IPPROTO_TCP) {
if (pd.dir == PF_IN && (pd.hdr.tcp.th_flags &
(TH_SYN|TH_ACK)) == TH_SYN &&
pf_synflood_check(&pd)) {
PF_LOCK();
have_pf_lock = 1;
pf_syncookie_send(&pd);
action = PF_DROP;
break;
}
if ((pd.hdr.tcp.th_flags & TH_ACK) && pd.p_len == 0)
pqid = 1;
action = pf_normalize_tcp(&pd);
if (action == PF_DROP)
break;
}
key.af = pd.af;
key.proto = pd.virtual_proto;
key.rdomain = pd.rdomain;
pf_addrcpy(&key.addr[pd.sidx], pd.src, key.af);
pf_addrcpy(&key.addr[pd.didx], pd.dst, key.af);
key.port[pd.sidx] = pd.osport;
key.port[pd.didx] = pd.odport;
key.hash = pd.hash;
PF_STATE_ENTER_READ();
action = pf_find_state(&pd, &key, &st);
st = pf_state_ref(st);
PF_STATE_EXIT_READ();
/* check for syncookies if tcp ack and no active state */
if (pd.dir == PF_IN && pd.virtual_proto == IPPROTO_TCP &&
(st == NULL || (st->src.state >= TCPS_FIN_WAIT_2 &&
st->dst.state >= TCPS_FIN_WAIT_2)) &&
(pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK|TH_RST)) == TH_ACK &&
pf_syncookie_validate(&pd)) {
struct mbuf *msyn = pf_syncookie_recreate_syn(&pd);
if (msyn) {
action = pf_test(af, fwdir, ifp, &msyn);
m_freem(msyn);
if (action == PF_PASS || action == PF_AFRT) {
PF_STATE_ENTER_READ();
pf_state_unref(st);
action = pf_find_state(&pd, &key, &st);
st = pf_state_ref(st);
PF_STATE_EXIT_READ();
if (st == NULL)
return (PF_DROP);
st->src.seqhi = st->dst.seqhi =
ntohl(pd.hdr.tcp.th_ack) - 1;
st->src.seqlo =
ntohl(pd.hdr.tcp.th_seq) - 1;
pf_set_protostate(st, PF_PEER_SRC,
PF_TCPS_PROXY_DST);
}
} else
action = PF_DROP;
}
if (action == PF_MATCH)
action = pf_test_state(&pd, &st, &reason);
if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
r = st->rule.ptr;
a = st->anchor.ptr;
#if NPFLOG > 0
pd.pflog |= st->log;
#endif /* NPFLOG > 0 */
} else if (st == NULL) {
PF_LOCK();
have_pf_lock = 1;
action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
&reason);
st = pf_state_ref(st);
}
if (pd.virtual_proto == IPPROTO_TCP) {
if (st) {
if (st->max_mss)
pf_normalize_mss(&pd, st->max_mss);
} else if (r->max_mss)
pf_normalize_mss(&pd, r->max_mss);
}
break;
}
if (have_pf_lock != 0)
PF_UNLOCK();
/*
* At the moment, we rely on NET_LOCK() to prevent removal of items
* we've collected above ('r', 'anchor' and 'ruleset'). They'll have
* to be refcounted when NET_LOCK() is gone.
*/
done:
if (action != PF_DROP) {
if (st) {
/* The non-state case is handled in pf_test_rule() */
if (action == PF_PASS && pd.badopts != 0 &&
!(st->state_flags & PFSTATE_ALLOWOPTS)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_IPOPTIONS);
#if NPFLOG > 0
pd.pflog |= PF_LOG_FORCE;
#endif /* NPFLOG > 0 */
DPFPRINTF(LOG_NOTICE, "dropping packet with "
"ip/ipv6 options in pf_test()");
}
pf_scrub(pd.m, st->state_flags, pd.af, st->min_ttl,
st->set_tos);
pf_tag_packet(pd.m, st->tag, st->rtableid[pd.didx]);
if (pqid || (pd.tos & IPTOS_LOWDELAY)) {
qid = st->pqid;
if (st->state_flags & PFSTATE_SETPRIO) {
pd.m->m_pkthdr.pf.prio =
st->set_prio[1];
}
} else {
qid = st->qid;
if (st->state_flags & PFSTATE_SETPRIO) {
pd.m->m_pkthdr.pf.prio =
st->set_prio[0];
}
}
pd.m->m_pkthdr.pf.delay = st->delay;
} else {
pf_scrub(pd.m, r->scrub_flags, pd.af, r->min_ttl,
r->set_tos);
if (pqid || (pd.tos & IPTOS_LOWDELAY)) {
qid = r->pqid;
if (r->scrub_flags & PFSTATE_SETPRIO)
pd.m->m_pkthdr.pf.prio = r->set_prio[1];
} else {
qid = r->qid;
if (r->scrub_flags & PFSTATE_SETPRIO)
pd.m->m_pkthdr.pf.prio = r->set_prio[0];
}
pd.m->m_pkthdr.pf.delay = r->delay;
}
}
if (action == PF_PASS && qid)
pd.m->m_pkthdr.pf.qid = qid;
if (pd.dir == PF_IN && st && st->key[PF_SK_STACK])
pf_mbuf_link_state_key(pd.m, st->key[PF_SK_STACK]);
if (pd.dir == PF_OUT && st && st->key[PF_SK_STACK])
pf_state_key_link_inpcb(st->key[PF_SK_STACK],
pd.m->m_pkthdr.pf.inp);
if (st != NULL && !ISSET(pd.m->m_pkthdr.csum_flags, M_FLOWID)) {
pd.m->m_pkthdr.ph_flowid = st->key[PF_SK_WIRE]->hash;
SET(pd.m->m_pkthdr.csum_flags, M_FLOWID);
}
/*
* connections redirected to loopback should not match sockets
* bound specifically to loopback due to security implications,
* see in_pcblookup_listen().
*/
if (pd.destchg)
if ((pd.af == AF_INET && (ntohl(pd.dst->v4.s_addr) >>
IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) ||
(pd.af == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6)))
pd.m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST;
/* We need to redo the route lookup on outgoing routes. */
if (pd.destchg && pd.dir == PF_OUT)
pd.m->m_pkthdr.pf.flags |= PF_TAG_REROUTE;
if (pd.dir == PF_IN && action == PF_PASS &&
(r->divert.type == PF_DIVERT_TO ||
r->divert.type == PF_DIVERT_REPLY)) {
struct pf_divert *divert;
if ((divert = pf_get_divert(pd.m))) {
pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED;
divert->addr = r->divert.addr;
divert->port = r->divert.port;
divert->rdomain = pd.rdomain;
divert->type = r->divert.type;
}
}
if (action == PF_PASS && r->divert.type == PF_DIVERT_PACKET)
action = PF_DIVERT;
#if NPFLOG > 0
if (pd.pflog) {
struct pf_rule_item *ri;
if (pd.pflog & PF_LOG_FORCE || r->log & PF_LOG_ALL)
pflog_packet(&pd, reason, r, a, ruleset, NULL);
if (st) {
SLIST_FOREACH(ri, &st->match_rules, entry)
if (ri->r->log & PF_LOG_ALL)
pflog_packet(&pd, reason, ri->r, a,
ruleset, NULL);
}
}
#endif /* NPFLOG > 0 */
pf_counters_inc(action, &pd, st, r, a);
switch (action) {
case PF_SYNPROXY_DROP:
m_freem(pd.m);
/* FALLTHROUGH */
case PF_DEFER:
pd.m = NULL;
action = PF_PASS;
break;
case PF_DIVERT:
switch (pd.af) {
case AF_INET:
divert_packet(pd.m, pd.dir, r->divert.port);
pd.m = NULL;
break;
#ifdef INET6
case AF_INET6:
divert6_packet(pd.m, pd.dir, r->divert.port);
pd.m = NULL;
break;
#endif /* INET6 */
}
action = PF_PASS;
break;
#ifdef INET6
case PF_AFRT:
if (pf_translate_af(&pd)) {
action = PF_DROP;
break;
}
pd.m->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
switch (pd.naf) {
case AF_INET:
if (pd.dir == PF_IN) {
if (ipforwarding == 0) {
ipstat_inc(ips_cantforward);
action = PF_DROP;
break;
}
ip_forward(pd.m, ifp, NULL, 1);
} else
ip_output(pd.m, NULL, NULL, 0, NULL, NULL, 0);
break;
case AF_INET6:
if (pd.dir == PF_IN) {
if (ip6_forwarding == 0) {
ip6stat_inc(ip6s_cantforward);
action = PF_DROP;
break;
}
ip6_forward(pd.m, NULL, 1);
} else
ip6_output(pd.m, NULL, NULL, 0, NULL, NULL);
break;
}
if (action != PF_DROP) {
pd.m = NULL;
action = PF_PASS;
}
break;
#endif /* INET6 */
case PF_DROP:
m_freem(pd.m);
pd.m = NULL;
break;
default:
if (st && st->rt) {
switch (pd.af) {
case AF_INET:
pf_route(&pd, st);
break;
#ifdef INET6
case AF_INET6:
pf_route6(&pd, st);
break;
#endif /* INET6 */
}
}
break;
}
#ifdef INET6
/* if reassembled packet passed, create new fragments */
if (pf_status.reass && action == PF_PASS && pd.m && fwdir == PF_FWD &&
pd.af == AF_INET6) {
struct m_tag *mtag;
if ((mtag = m_tag_find(pd.m, PACKET_TAG_PF_REASSEMBLED, NULL)))
action = pf_refragment6(&pd.m, mtag, NULL, NULL, NULL);
}
#endif /* INET6 */
if (st && action != PF_DROP) {
if (!st->if_index_in && dir == PF_IN)
st->if_index_in = ifp->if_index;
else if (!st->if_index_out && dir == PF_OUT)
st->if_index_out = ifp->if_index;
}
*m0 = pd.m;
pf_state_unref(st);
return (action);
}
int
pf_ouraddr(struct mbuf *m)
{
struct pf_state_key *sk;
if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED)
return (1);
sk = m->m_pkthdr.pf.statekey;
if (sk != NULL) {
if (READ_ONCE(sk->sk_inp) != NULL)
return (1);
}
return (-1);
}
/*
* must be called whenever any addressing information such as
* address, port, protocol has changed
*/
void
pf_pkt_addr_changed(struct mbuf *m)
{
pf_mbuf_unlink_state_key(m);
pf_mbuf_unlink_inpcb(m);
}
struct inpcb *
pf_inp_lookup(struct mbuf *m)
{
struct inpcb *inp = NULL;
struct pf_state_key *sk = m->m_pkthdr.pf.statekey;
if (!pf_state_key_isvalid(sk))
pf_mbuf_unlink_state_key(m);
else if (READ_ONCE(sk->sk_inp) != NULL) {
mtx_enter(&pf_inp_mtx);
inp = in_pcbref(sk->sk_inp);
mtx_leave(&pf_inp_mtx);
}
return (inp);
}
void
pf_inp_link(struct mbuf *m, struct inpcb *inp)
{
struct pf_state_key *sk = m->m_pkthdr.pf.statekey;
if (!pf_state_key_isvalid(sk)) {
pf_mbuf_unlink_state_key(m);
return;
}
/*
* we don't need to grab PF-lock here. At worst case we link inp to
* state, which might be just being marked as deleted by another
* thread.
*/
pf_state_key_link_inpcb(sk, inp);
/* The statekey has finished finding the inp, it is no longer needed. */
pf_mbuf_unlink_state_key(m);
}
void
pf_inp_unlink(struct inpcb *inp)
{
struct pf_state_key *sk;
if (READ_ONCE(inp->inp_pf_sk) == NULL)
return;
mtx_enter(&pf_inp_mtx);
sk = inp->inp_pf_sk;
if (sk == NULL) {
mtx_leave(&pf_inp_mtx);
return;
}
KASSERT(sk->sk_inp == inp);
sk->sk_inp = NULL;
inp->inp_pf_sk = NULL;
mtx_leave(&pf_inp_mtx);
pf_state_key_unref(sk);
in_pcbunref(inp);
}
void
pf_state_key_link_reverse(struct pf_state_key *sk, struct pf_state_key *skrev)
{
struct pf_state_key *old_reverse;
old_reverse = atomic_cas_ptr(&sk->sk_reverse, NULL, skrev);
if (old_reverse != NULL)
KASSERT(old_reverse == skrev);
else {
pf_state_key_ref(skrev);
/*
* NOTE: if sk == skrev, then KASSERT() below holds true, we
* still want to grab a reference in such case, because
* pf_state_key_unlink_reverse() does not check whether keys
* are identical or not.
*/
old_reverse = atomic_cas_ptr(&skrev->sk_reverse, NULL, sk);
if (old_reverse != NULL)
KASSERT(old_reverse == sk);
pf_state_key_ref(sk);
}
}
#if NPFLOG > 0
void
pf_log_matches(struct pf_pdesc *pd, struct pf_rule *rm, struct pf_rule *am,
struct pf_ruleset *ruleset, struct pf_rule_slist *matchrules)
{
struct pf_rule_item *ri;
/* if this is the log(matches) rule, packet has been logged already */
if (rm->log & PF_LOG_MATCHES)
return;
SLIST_FOREACH(ri, matchrules, entry)
if (ri->r->log & PF_LOG_MATCHES)
pflog_packet(pd, PFRES_MATCH, rm, am, ruleset, ri->r);
}
#endif /* NPFLOG > 0 */
struct pf_state_key *
pf_state_key_ref(struct pf_state_key *sk)
{
if (sk != NULL)
PF_REF_TAKE(sk->sk_refcnt);
return (sk);
}
void
pf_state_key_unref(struct pf_state_key *sk)
{
if (PF_REF_RELE(sk->sk_refcnt)) {
/* state key must be removed from tree */
KASSERT(!pf_state_key_isvalid(sk));
/* state key must be unlinked from reverse key */
KASSERT(sk->sk_reverse == NULL);
/* state key must be unlinked from socket */
KASSERT(sk->sk_inp == NULL);
pool_put(&pf_state_key_pl, sk);
}
}
int
pf_state_key_isvalid(struct pf_state_key *sk)
{
return ((sk != NULL) && (sk->sk_removed == 0));
}
void
pf_mbuf_link_state_key(struct mbuf *m, struct pf_state_key *sk)
{
KASSERT(m->m_pkthdr.pf.statekey == NULL);
m->m_pkthdr.pf.statekey = pf_state_key_ref(sk);
}
void
pf_mbuf_unlink_state_key(struct mbuf *m)
{
struct pf_state_key *sk = m->m_pkthdr.pf.statekey;
if (sk != NULL) {
m->m_pkthdr.pf.statekey = NULL;
pf_state_key_unref(sk);
}
}
void
pf_mbuf_link_inpcb(struct mbuf *m, struct inpcb *inp)
{
KASSERT(m->m_pkthdr.pf.inp == NULL);
m->m_pkthdr.pf.inp = in_pcbref(inp);
}
void
pf_mbuf_unlink_inpcb(struct mbuf *m)
{
struct inpcb *inp = m->m_pkthdr.pf.inp;
if (inp != NULL) {
m->m_pkthdr.pf.inp = NULL;
in_pcbunref(inp);
}
}
void
pf_state_key_link_inpcb(struct pf_state_key *sk, struct inpcb *inp)
{
if (inp == NULL || READ_ONCE(sk->sk_inp) != NULL)
return;
mtx_enter(&pf_inp_mtx);
if (inp->inp_pf_sk != NULL || sk->sk_inp != NULL) {
mtx_leave(&pf_inp_mtx);
return;
}
sk->sk_inp = in_pcbref(inp);
inp->inp_pf_sk = pf_state_key_ref(sk);
mtx_leave(&pf_inp_mtx);
}
void
pf_state_key_unlink_inpcb(struct pf_state_key *sk)
{
struct inpcb *inp;
if (READ_ONCE(sk->sk_inp) == NULL)
return;
mtx_enter(&pf_inp_mtx);
inp = sk->sk_inp;
if (inp == NULL) {
mtx_leave(&pf_inp_mtx);
return;
}
KASSERT(inp->inp_pf_sk == sk);
sk->sk_inp = NULL;
inp->inp_pf_sk = NULL;
mtx_leave(&pf_inp_mtx);
pf_state_key_unref(sk);
in_pcbunref(inp);
}
void
pf_state_key_unlink_reverse(struct pf_state_key *sk)
{
struct pf_state_key *skrev = sk->sk_reverse;
/* Note that sk and skrev may be equal, then we unref twice. */
if (skrev != NULL) {
KASSERT(skrev->sk_reverse == sk);
sk->sk_reverse = NULL;
skrev->sk_reverse = NULL;
pf_state_key_unref(skrev);
pf_state_key_unref(sk);
}
}
struct pf_state *
pf_state_ref(struct pf_state *st)
{
if (st != NULL)
PF_REF_TAKE(st->refcnt);
return (st);
}
void
pf_state_unref(struct pf_state *st)
{
if ((st != NULL) && PF_REF_RELE(st->refcnt)) {
/* never inserted or removed */
#if NPFSYNC > 0
KASSERT((TAILQ_NEXT(st, sync_list) == NULL) ||
((TAILQ_NEXT(st, sync_list) == _Q_INVALID) &&
(st->sync_state >= PFSYNC_S_NONE)));
#endif /* NPFSYNC */
KASSERT((TAILQ_NEXT(st, entry_list) == NULL) ||
(TAILQ_NEXT(st, entry_list) == _Q_INVALID));
pf_state_key_unref(st->key[PF_SK_WIRE]);
pf_state_key_unref(st->key[PF_SK_STACK]);
pool_put(&pf_state_pl, st);
}
}
int
pf_delay_pkt(struct mbuf *m, u_int ifidx)
{
struct pf_pktdelay *pdy;
if ((pdy = pool_get(&pf_pktdelay_pl, PR_NOWAIT)) == NULL) {
m_freem(m);
return (ENOBUFS);
}
pdy->ifidx = ifidx;
pdy->m = m;
timeout_set(&pdy->to, pf_pktenqueue_delayed, pdy);
timeout_add_msec(&pdy->to, m->m_pkthdr.pf.delay);
m->m_pkthdr.pf.delay = 0;
return (0);
}
void
pf_pktenqueue_delayed(void *arg)
{
struct pf_pktdelay *pdy = arg;
struct ifnet *ifp;
ifp = if_get(pdy->ifidx);
if (ifp != NULL) {
if_enqueue(ifp, pdy->m);
if_put(ifp);
} else
m_freem(pdy->m);
pool_put(&pf_pktdelay_pl, pdy);
}
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