File: [local] / src / usr.bin / nc / netcat.c (download)
Revision 1.226, Mon Aug 14 08:07:27 2023 UTC (9 months ago) by tb
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, HEAD
Changes since 1.225: +9 -3 lines
netcat: avoid issuing syscalls on fd -1
In case a socket error condition occurs, readwrite() invalidates the
corresponding fd. Later on, readwrite() may still issue a syscall on
it. Avoid that by adding a couple of checks for fd == -1.
Reported and fix suggested by Leah Neukirchen.
Fixes https://github.com/libressl/openbsd/issues/143
"looks right" deraadt
|
/* $OpenBSD: netcat.c,v 1.226 2023/08/14 08:07:27 tb Exp $ */
/*
* Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
* Copyright (c) 2015 Bob Beck. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* Re-written nc(1) for OpenBSD. Original implementation by
* *Hobbit* <hobbit@avian.org>.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>
#include <arpa/telnet.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <netdb.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tls.h>
#include <unistd.h>
#include "atomicio.h"
#define PORT_MAX 65535
#define UNIX_DG_TMP_SOCKET_SIZE 19
#define POLL_STDIN 0
#define POLL_NETOUT 1
#define POLL_NETIN 2
#define POLL_STDOUT 3
#define BUFSIZE 16384
#define TLS_NOVERIFY (1 << 1)
#define TLS_NONAME (1 << 2)
#define TLS_CCERT (1 << 3)
#define TLS_MUSTSTAPLE (1 << 4)
/* Command Line Options */
int dflag; /* detached, no stdin */
int Fflag; /* fdpass sock to stdout */
unsigned int iflag; /* Interval Flag */
int kflag; /* More than one connect */
int lflag; /* Bind to local port */
int Nflag; /* shutdown() network socket */
int nflag; /* Don't do name look up */
char *Pflag; /* Proxy username */
char *pflag; /* Localport flag */
int rflag; /* Random ports flag */
char *sflag; /* Source Address */
int tflag; /* Telnet Emulation */
int uflag; /* UDP - Default to TCP */
int vflag; /* Verbosity */
int xflag; /* Socks proxy */
int zflag; /* Port Scan Flag */
int Dflag; /* sodebug */
int Iflag; /* TCP receive buffer size */
int Oflag; /* TCP send buffer size */
int Sflag; /* TCP MD5 signature option */
int Tflag = -1; /* IP Type of Service */
int rtableid = -1;
int usetls; /* use TLS */
const char *Cflag; /* Public cert file */
const char *Kflag; /* Private key file */
const char *oflag; /* OCSP stapling file */
const char *Rflag; /* Root CA file */
int tls_cachanged; /* Using non-default CA file */
int TLSopt; /* TLS options */
char *tls_expectname; /* required name in peer cert */
char *tls_expecthash; /* required hash of peer cert */
char *tls_ciphers; /* TLS ciphers */
char *tls_protocols; /* TLS protocols */
FILE *Zflag; /* file to save peer cert */
int recvcount, recvlimit;
int timeout = -1;
int family = AF_UNSPEC;
char *portlist[PORT_MAX+1];
char *unix_dg_tmp_socket;
int ttl = -1;
int minttl = -1;
void atelnet(int, unsigned char *, unsigned int);
int strtoport(char *portstr, int udp);
void build_ports(char *);
void help(void) __attribute__((noreturn));
int local_listen(const char *, const char *, struct addrinfo);
void readwrite(int, struct tls *);
void fdpass(int nfd) __attribute__((noreturn));
int remote_connect(const char *, const char *, struct addrinfo, char *);
int timeout_tls(int, struct tls *, int (*)(struct tls *));
int timeout_connect(int, const struct sockaddr *, socklen_t);
int socks_connect(const char *, const char *, struct addrinfo,
const char *, const char *, struct addrinfo, int, const char *);
int udptest(int);
void connection_info(const char *, const char *, const char *, const char *);
int unix_bind(char *, int);
int unix_connect(char *);
int unix_listen(char *);
void set_common_sockopts(int, int);
int process_tos_opt(char *, int *);
int process_tls_opt(char *, int *);
void save_peer_cert(struct tls *_tls_ctx, FILE *_fp);
void report_sock(const char *, const struct sockaddr *, socklen_t, char *);
void report_tls(struct tls *tls_ctx, char * host);
void usage(int);
ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *);
ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *);
void tls_setup_client(struct tls *, int, char *);
struct tls *tls_setup_server(struct tls *, int, char *);
int
main(int argc, char *argv[])
{
int ch, s = -1, ret, socksv;
char *host, *uport;
char ipaddr[NI_MAXHOST];
struct addrinfo hints;
socklen_t len;
struct sockaddr_storage cliaddr;
char *proxy = NULL, *proxyport = NULL;
const char *errstr;
struct addrinfo proxyhints;
char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE];
struct tls_config *tls_cfg = NULL;
struct tls *tls_ctx = NULL;
uint32_t protocols;
ret = 1;
socksv = 5;
host = NULL;
uport = NULL;
Rflag = tls_default_ca_cert_file();
signal(SIGPIPE, SIG_IGN);
while ((ch = getopt(argc, argv,
"46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z"))
!= -1) {
switch (ch) {
case '4':
family = AF_INET;
break;
case '6':
family = AF_INET6;
break;
case 'U':
family = AF_UNIX;
break;
case 'X':
if (strcasecmp(optarg, "connect") == 0)
socksv = -1; /* HTTP proxy CONNECT */
else if (strcmp(optarg, "4") == 0)
socksv = 4; /* SOCKS v.4 */
else if (strcmp(optarg, "5") == 0)
socksv = 5; /* SOCKS v.5 */
else
errx(1, "unsupported proxy protocol");
break;
case 'C':
Cflag = optarg;
break;
case 'c':
usetls = 1;
break;
case 'd':
dflag = 1;
break;
case 'e':
tls_expectname = optarg;
break;
case 'F':
Fflag = 1;
break;
case 'H':
tls_expecthash = optarg;
break;
case 'h':
help();
break;
case 'i':
iflag = strtonum(optarg, 0, UINT_MAX, &errstr);
if (errstr)
errx(1, "interval %s: %s", errstr, optarg);
break;
case 'K':
Kflag = optarg;
break;
case 'k':
kflag = 1;
break;
case 'l':
lflag = 1;
break;
case 'M':
ttl = strtonum(optarg, 0, 255, &errstr);
if (errstr)
errx(1, "ttl is %s", errstr);
break;
case 'm':
minttl = strtonum(optarg, 0, 255, &errstr);
if (errstr)
errx(1, "minttl is %s", errstr);
break;
case 'N':
Nflag = 1;
break;
case 'n':
nflag = 1;
break;
case 'P':
Pflag = optarg;
break;
case 'p':
pflag = optarg;
break;
case 'R':
tls_cachanged = 1;
Rflag = optarg;
break;
case 'r':
rflag = 1;
break;
case 's':
sflag = optarg;
break;
case 't':
tflag = 1;
break;
case 'u':
uflag = 1;
break;
case 'V':
rtableid = (int)strtonum(optarg, 0,
RT_TABLEID_MAX, &errstr);
if (errstr)
errx(1, "rtable %s: %s", errstr, optarg);
break;
case 'v':
vflag = 1;
break;
case 'W':
recvlimit = strtonum(optarg, 1, INT_MAX, &errstr);
if (errstr)
errx(1, "receive limit %s: %s", errstr, optarg);
break;
case 'w':
timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr);
if (errstr)
errx(1, "timeout %s: %s", errstr, optarg);
timeout *= 1000;
break;
case 'x':
xflag = 1;
if ((proxy = strdup(optarg)) == NULL)
err(1, NULL);
break;
case 'Z':
if (strcmp(optarg, "-") == 0)
Zflag = stderr;
else if ((Zflag = fopen(optarg, "w")) == NULL)
err(1, "can't open %s", optarg);
break;
case 'z':
zflag = 1;
break;
case 'D':
Dflag = 1;
break;
case 'I':
Iflag = strtonum(optarg, 1, 65536 << 14, &errstr);
if (errstr != NULL)
errx(1, "TCP receive window %s: %s",
errstr, optarg);
break;
case 'O':
Oflag = strtonum(optarg, 1, 65536 << 14, &errstr);
if (errstr != NULL)
errx(1, "TCP send window %s: %s",
errstr, optarg);
break;
case 'o':
oflag = optarg;
break;
case 'S':
Sflag = 1;
break;
case 'T':
errstr = NULL;
errno = 0;
if (process_tls_opt(optarg, &TLSopt))
break;
if (process_tos_opt(optarg, &Tflag))
break;
if (strlen(optarg) > 1 && optarg[0] == '0' &&
optarg[1] == 'x')
Tflag = (int)strtol(optarg, NULL, 16);
else
Tflag = (int)strtonum(optarg, 0, 255,
&errstr);
if (Tflag < 0 || Tflag > 255 || errstr || errno)
errx(1, "illegal tos/tls value %s", optarg);
break;
default:
usage(1);
}
}
argc -= optind;
argv += optind;
if (rtableid >= 0)
if (setrtable(rtableid) == -1)
err(1, "setrtable");
/* Cruft to make sure options are clean, and used properly. */
if (argc == 1 && family == AF_UNIX) {
host = argv[0];
} else if (argc == 1 && lflag) {
uport = argv[0];
} else if (argc == 2) {
host = argv[0];
uport = argv[1];
} else
usage(1);
if (usetls) {
if (Cflag && unveil(Cflag, "r") == -1)
err(1, "unveil %s", Cflag);
if (unveil(Rflag, "r") == -1)
err(1, "unveil %s", Rflag);
if (Kflag && unveil(Kflag, "r") == -1)
err(1, "unveil %s", Kflag);
if (oflag && unveil(oflag, "r") == -1)
err(1, "unveil %s", oflag);
} else if (family == AF_UNIX && uflag && lflag && !kflag) {
/*
* After recvfrom(2) from client, the server connects
* to the client socket. As the client path is determined
* during runtime, we cannot unveil(2).
*/
} else {
if (family == AF_UNIX) {
if (unveil(host, "rwc") == -1)
err(1, "unveil %s", host);
if (uflag && !kflag) {
if (sflag) {
if (unveil(sflag, "rwc") == -1)
err(1, "unveil %s", sflag);
} else {
if (unveil("/tmp", "rwc") == -1)
err(1, "unveil /tmp");
}
}
} else {
/* no filesystem visibility */
if (unveil("/", "") == -1)
err(1, "unveil /");
}
}
if (family == AF_UNIX) {
if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1)
err(1, "pledge");
} else if (Fflag && Pflag) {
if (pledge("stdio inet dns sendfd tty", NULL) == -1)
err(1, "pledge");
} else if (Fflag) {
if (pledge("stdio inet dns sendfd", NULL) == -1)
err(1, "pledge");
} else if (Pflag && usetls) {
if (pledge("stdio rpath inet dns tty", NULL) == -1)
err(1, "pledge");
} else if (Pflag) {
if (pledge("stdio inet dns tty", NULL) == -1)
err(1, "pledge");
} else if (usetls) {
if (pledge("stdio rpath inet dns", NULL) == -1)
err(1, "pledge");
} else if (pledge("stdio inet dns", NULL) == -1)
err(1, "pledge");
if (lflag && sflag)
errx(1, "cannot use -s and -l");
if (lflag && pflag)
errx(1, "cannot use -p and -l");
if (lflag && zflag)
errx(1, "cannot use -z and -l");
if (!lflag && kflag)
errx(1, "must use -l with -k");
if (uflag && usetls)
errx(1, "cannot use -c and -u");
if ((family == AF_UNIX) && usetls)
errx(1, "cannot use -c and -U");
if ((family == AF_UNIX) && Fflag)
errx(1, "cannot use -F and -U");
if (Fflag && usetls)
errx(1, "cannot use -c and -F");
if (TLSopt && !usetls)
errx(1, "you must specify -c to use TLS options");
if (Cflag && !usetls)
errx(1, "you must specify -c to use -C");
if (Kflag && !usetls)
errx(1, "you must specify -c to use -K");
if (Zflag && !usetls)
errx(1, "you must specify -c to use -Z");
if (oflag && !Cflag)
errx(1, "you must specify -C to use -o");
if (tls_cachanged && !usetls)
errx(1, "you must specify -c to use -R");
if (tls_expecthash && !usetls)
errx(1, "you must specify -c to use -H");
if (tls_expectname && !usetls)
errx(1, "you must specify -c to use -e");
/* Get name of temporary socket for unix datagram client */
if ((family == AF_UNIX) && uflag && !lflag) {
if (sflag) {
unix_dg_tmp_socket = sflag;
} else {
strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX",
UNIX_DG_TMP_SOCKET_SIZE);
if (mktemp(unix_dg_tmp_socket_buf) == NULL)
err(1, "mktemp");
unix_dg_tmp_socket = unix_dg_tmp_socket_buf;
}
}
/* Initialize addrinfo structure. */
if (family != AF_UNIX) {
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = family;
hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP;
if (nflag)
hints.ai_flags |= AI_NUMERICHOST;
}
if (xflag) {
if (uflag)
errx(1, "no proxy support for UDP mode");
if (lflag)
errx(1, "no proxy support for listen");
if (family == AF_UNIX)
errx(1, "no proxy support for unix sockets");
if (sflag)
errx(1, "no proxy support for local source address");
if (*proxy == '[') {
++proxy;
proxyport = strchr(proxy, ']');
if (proxyport == NULL)
errx(1, "missing closing bracket in proxy");
*proxyport++ = '\0';
if (*proxyport == '\0')
/* Use default proxy port. */
proxyport = NULL;
else {
if (*proxyport == ':')
++proxyport;
else
errx(1, "garbage proxy port delimiter");
}
} else {
proxyport = strrchr(proxy, ':');
if (proxyport != NULL)
*proxyport++ = '\0';
}
memset(&proxyhints, 0, sizeof(struct addrinfo));
proxyhints.ai_family = family;
proxyhints.ai_socktype = SOCK_STREAM;
proxyhints.ai_protocol = IPPROTO_TCP;
if (nflag)
proxyhints.ai_flags |= AI_NUMERICHOST;
}
if (usetls) {
if ((tls_cfg = tls_config_new()) == NULL)
errx(1, "unable to allocate TLS config");
if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (tls_config_parse_protocols(&protocols, tls_protocols) == -1)
errx(1, "invalid TLS protocols `%s'", tls_protocols);
if (tls_config_set_protocols(tls_cfg, protocols) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1)
errx(1, "%s", tls_config_error(tls_cfg));
if (!lflag && (TLSopt & TLS_CCERT))
errx(1, "clientcert is only valid with -l");
if (TLSopt & TLS_NONAME)
tls_config_insecure_noverifyname(tls_cfg);
if (TLSopt & TLS_NOVERIFY) {
if (tls_expecthash != NULL)
errx(1, "-H and -T noverify may not be used "
"together");
tls_config_insecure_noverifycert(tls_cfg);
}
if (TLSopt & TLS_MUSTSTAPLE)
tls_config_ocsp_require_stapling(tls_cfg);
if (Pflag) {
if (pledge("stdio inet dns tty", NULL) == -1)
err(1, "pledge");
} else if (pledge("stdio inet dns", NULL) == -1)
err(1, "pledge");
}
if (lflag) {
ret = 0;
if (family == AF_UNIX) {
if (uflag)
s = unix_bind(host, 0);
else
s = unix_listen(host);
}
if (usetls) {
tls_config_verify_client_optional(tls_cfg);
if ((tls_ctx = tls_server()) == NULL)
errx(1, "tls server creation failed");
if (tls_configure(tls_ctx, tls_cfg) == -1)
errx(1, "tls configuration failed (%s)",
tls_error(tls_ctx));
}
/* Allow only one connection at a time, but stay alive. */
for (;;) {
if (family != AF_UNIX) {
if (s != -1)
close(s);
s = local_listen(host, uport, hints);
}
if (s == -1)
err(1, NULL);
if (uflag && kflag) {
if (family == AF_UNIX) {
if (pledge("stdio unix", NULL) == -1)
err(1, "pledge");
}
/*
* For UDP and -k, don't connect the socket,
* let it receive datagrams from multiple
* socket pairs.
*/
readwrite(s, NULL);
} else if (uflag && !kflag) {
/*
* For UDP and not -k, we will use recvfrom()
* initially to wait for a caller, then use
* the regular functions to talk to the caller.
*/
int rv;
char buf[2048];
struct sockaddr_storage z;
len = sizeof(z);
rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK,
(struct sockaddr *)&z, &len);
if (rv == -1)
err(1, "recvfrom");
rv = connect(s, (struct sockaddr *)&z, len);
if (rv == -1)
err(1, "connect");
if (family == AF_UNIX) {
if (pledge("stdio unix", NULL) == -1)
err(1, "pledge");
}
if (vflag)
report_sock("Connection received",
(struct sockaddr *)&z, len,
family == AF_UNIX ? host : NULL);
readwrite(s, NULL);
} else {
struct tls *tls_cctx = NULL;
int connfd;
len = sizeof(cliaddr);
connfd = accept4(s, (struct sockaddr *)&cliaddr,
&len, SOCK_NONBLOCK);
if (connfd == -1) {
/* For now, all errnos are fatal */
err(1, "accept");
}
if (vflag)
report_sock("Connection received",
(struct sockaddr *)&cliaddr, len,
family == AF_UNIX ? host : NULL);
if ((usetls) &&
(tls_cctx = tls_setup_server(tls_ctx, connfd, host)))
readwrite(connfd, tls_cctx);
if (!usetls)
readwrite(connfd, NULL);
if (tls_cctx)
timeout_tls(s, tls_cctx, tls_close);
close(connfd);
tls_free(tls_cctx);
}
if (family == AF_UNIX && uflag) {
if (connect(s, NULL, 0) == -1)
err(1, "connect");
}
if (!kflag)
break;
}
} else if (family == AF_UNIX) {
ret = 0;
if ((s = unix_connect(host)) > 0) {
if (!zflag)
readwrite(s, NULL);
close(s);
} else {
warn("%s", host);
ret = 1;
}
if (uflag)
unlink(unix_dg_tmp_socket);
return ret;
} else {
int i = 0;
/* Construct the portlist[] array. */
build_ports(uport);
/* Cycle through portlist, connecting to each port. */
for (s = -1, i = 0; portlist[i] != NULL; i++) {
if (s != -1)
close(s);
tls_free(tls_ctx);
tls_ctx = NULL;
if (usetls) {
if ((tls_ctx = tls_client()) == NULL)
errx(1, "tls client creation failed");
if (tls_configure(tls_ctx, tls_cfg) == -1)
errx(1, "tls configuration failed (%s)",
tls_error(tls_ctx));
}
if (xflag)
s = socks_connect(host, portlist[i], hints,
proxy, proxyport, proxyhints, socksv,
Pflag);
else
s = remote_connect(host, portlist[i], hints,
ipaddr);
if (s == -1)
continue;
ret = 0;
if (vflag || zflag) {
int print_info = 1;
/* For UDP, make sure we are connected. */
if (uflag) {
/* No info on failed or skipped test. */
if ((print_info = udptest(s)) == -1) {
ret = 1;
continue;
}
}
if (print_info == 1)
connection_info(host, portlist[i],
uflag ? "udp" : "tcp", ipaddr);
}
if (Fflag)
fdpass(s);
else {
if (usetls)
tls_setup_client(tls_ctx, s, host);
if (!zflag)
readwrite(s, tls_ctx);
if (tls_ctx)
timeout_tls(s, tls_ctx, tls_close);
}
}
}
if (s != -1)
close(s);
tls_free(tls_ctx);
tls_config_free(tls_cfg);
return ret;
}
/*
* unix_bind()
* Returns a unix socket bound to the given path
*/
int
unix_bind(char *path, int flags)
{
struct sockaddr_un s_un;
int s, save_errno;
/* Create unix domain socket. */
if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM),
0)) == -1)
return -1;
memset(&s_un, 0, sizeof(struct sockaddr_un));
s_un.sun_family = AF_UNIX;
if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >=
sizeof(s_un.sun_path)) {
close(s);
errno = ENAMETOOLONG;
return -1;
}
if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) {
save_errno = errno;
close(s);
errno = save_errno;
return -1;
}
if (vflag)
report_sock("Bound", NULL, 0, path);
return s;
}
int
timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *))
{
struct pollfd pfd;
int ret;
while ((ret = (*func)(tls_ctx)) != 0) {
if (ret == TLS_WANT_POLLIN)
pfd.events = POLLIN;
else if (ret == TLS_WANT_POLLOUT)
pfd.events = POLLOUT;
else
break;
pfd.fd = s;
if ((ret = poll(&pfd, 1, timeout)) == 1)
continue;
else if (ret == 0) {
errno = ETIMEDOUT;
ret = -1;
break;
} else
err(1, "poll failed");
}
return ret;
}
void
tls_setup_client(struct tls *tls_ctx, int s, char *host)
{
const char *errstr;
if (tls_connect_socket(tls_ctx, s,
tls_expectname ? tls_expectname : host) == -1) {
errx(1, "tls connection failed (%s)",
tls_error(tls_ctx));
}
if (timeout_tls(s, tls_ctx, tls_handshake) == -1) {
if ((errstr = tls_error(tls_ctx)) == NULL)
errstr = strerror(errno);
errx(1, "tls handshake failed (%s)", errstr);
}
if (vflag)
report_tls(tls_ctx, host);
if (tls_expecthash && (tls_peer_cert_hash(tls_ctx) == NULL ||
strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0))
errx(1, "peer certificate is not %s", tls_expecthash);
if (Zflag) {
save_peer_cert(tls_ctx, Zflag);
if (Zflag != stderr && (fclose(Zflag) != 0))
err(1, "fclose failed saving peer cert");
}
}
struct tls *
tls_setup_server(struct tls *tls_ctx, int connfd, char *host)
{
struct tls *tls_cctx;
const char *errstr;
if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) {
warnx("tls accept failed (%s)", tls_error(tls_ctx));
} else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) {
if ((errstr = tls_error(tls_cctx)) == NULL)
errstr = strerror(errno);
warnx("tls handshake failed (%s)", errstr);
} else {
int gotcert = tls_peer_cert_provided(tls_cctx);
if (vflag && gotcert)
report_tls(tls_cctx, host);
if ((TLSopt & TLS_CCERT) && !gotcert)
warnx("No client certificate provided");
else if (gotcert && tls_expecthash &&
(tls_peer_cert_hash(tls_cctx) == NULL ||
strcmp(tls_expecthash, tls_peer_cert_hash(tls_cctx)) != 0))
warnx("peer certificate is not %s", tls_expecthash);
else if (gotcert && tls_expectname &&
(!tls_peer_cert_contains_name(tls_cctx, tls_expectname)))
warnx("name (%s) not found in client cert",
tls_expectname);
else {
return tls_cctx;
}
}
return NULL;
}
/*
* unix_connect()
* Returns a socket connected to a local unix socket. Returns -1 on failure.
*/
int
unix_connect(char *path)
{
struct sockaddr_un s_un;
int s, save_errno;
if (uflag) {
if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1)
return -1;
} else {
if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1)
return -1;
}
memset(&s_un, 0, sizeof(struct sockaddr_un));
s_un.sun_family = AF_UNIX;
if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >=
sizeof(s_un.sun_path)) {
close(s);
errno = ENAMETOOLONG;
return -1;
}
if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) {
save_errno = errno;
close(s);
errno = save_errno;
return -1;
}
return s;
}
/*
* unix_listen()
* Create a unix domain socket, and listen on it.
*/
int
unix_listen(char *path)
{
int s;
if ((s = unix_bind(path, 0)) == -1)
return -1;
if (listen(s, 5) == -1) {
close(s);
return -1;
}
if (vflag)
report_sock("Listening", NULL, 0, path);
return s;
}
/*
* remote_connect()
* Returns a socket connected to a remote host. Properly binds to a local
* port or source address if needed. Returns -1 on failure.
*/
int
remote_connect(const char *host, const char *port, struct addrinfo hints,
char *ipaddr)
{
struct addrinfo *res, *res0;
int s = -1, error, herr, on = 1, save_errno;
if ((error = getaddrinfo(host, port, &hints, &res0)))
errx(1, "getaddrinfo for host \"%s\" port %s: %s", host,
port, gai_strerror(error));
for (res = res0; res; res = res->ai_next) {
if ((s = socket(res->ai_family, res->ai_socktype |
SOCK_NONBLOCK, res->ai_protocol)) == -1)
continue;
/* Bind to a local port or source address if specified. */
if (sflag || pflag) {
struct addrinfo ahints, *ares;
/* try SO_BINDANY, but don't insist */
setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on));
memset(&ahints, 0, sizeof(struct addrinfo));
ahints.ai_family = res->ai_family;
ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP;
ahints.ai_flags = AI_PASSIVE;
if ((error = getaddrinfo(sflag, pflag, &ahints, &ares)))
errx(1, "getaddrinfo: %s", gai_strerror(error));
if (bind(s, (struct sockaddr *)ares->ai_addr,
ares->ai_addrlen) == -1)
err(1, "bind failed");
freeaddrinfo(ares);
}
set_common_sockopts(s, res->ai_family);
if (ipaddr != NULL) {
herr = getnameinfo(res->ai_addr, res->ai_addrlen,
ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
switch (herr) {
case 0:
break;
case EAI_SYSTEM:
err(1, "getnameinfo");
default:
errx(1, "getnameinfo: %s", gai_strerror(herr));
}
}
if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0)
break;
if (vflag) {
/* only print IP if there is something to report */
if (nflag || ipaddr == NULL ||
(strncmp(host, ipaddr, NI_MAXHOST) == 0))
warn("connect to %s port %s (%s) failed", host,
port, uflag ? "udp" : "tcp");
else
warn("connect to %s (%s) port %s (%s) failed",
host, ipaddr, port, uflag ? "udp" : "tcp");
}
save_errno = errno;
close(s);
errno = save_errno;
s = -1;
}
freeaddrinfo(res0);
return s;
}
int
timeout_connect(int s, const struct sockaddr *name, socklen_t namelen)
{
struct pollfd pfd;
socklen_t optlen;
int optval;
int ret;
if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) {
pfd.fd = s;
pfd.events = POLLOUT;
if ((ret = poll(&pfd, 1, timeout)) == 1) {
optlen = sizeof(optval);
if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR,
&optval, &optlen)) == 0) {
errno = optval;
ret = optval == 0 ? 0 : -1;
}
} else if (ret == 0) {
errno = ETIMEDOUT;
ret = -1;
} else
err(1, "poll failed");
}
return ret;
}
/*
* local_listen()
* Returns a socket listening on a local port, binds to specified source
* address. Returns -1 on failure.
*/
int
local_listen(const char *host, const char *port, struct addrinfo hints)
{
struct addrinfo *res, *res0;
int s = -1, ret, x = 1, save_errno;
int error;
/* Allow nodename to be null. */
hints.ai_flags |= AI_PASSIVE;
/*
* In the case of binding to a wildcard address
* default to binding to an ipv4 address.
*/
if (host == NULL && hints.ai_family == AF_UNSPEC)
hints.ai_family = AF_INET;
if ((error = getaddrinfo(host, port, &hints, &res0)))
errx(1, "getaddrinfo: %s", gai_strerror(error));
for (res = res0; res; res = res->ai_next) {
if ((s = socket(res->ai_family, res->ai_socktype,
res->ai_protocol)) == -1)
continue;
ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x));
if (ret == -1)
err(1, NULL);
set_common_sockopts(s, res->ai_family);
if (bind(s, (struct sockaddr *)res->ai_addr,
res->ai_addrlen) == 0)
break;
save_errno = errno;
close(s);
errno = save_errno;
s = -1;
}
if (!uflag && s != -1) {
if (listen(s, 1) == -1)
err(1, "listen");
}
if (vflag && s != -1) {
struct sockaddr_storage ss;
socklen_t len;
len = sizeof(ss);
if (getsockname(s, (struct sockaddr *)&ss, &len) == -1)
err(1, "getsockname");
report_sock(uflag ? "Bound" : "Listening",
(struct sockaddr *)&ss, len, NULL);
}
freeaddrinfo(res0);
return s;
}
/*
* readwrite()
* Loop that polls on the network file descriptor and stdin.
*/
void
readwrite(int net_fd, struct tls *tls_ctx)
{
struct pollfd pfd[4];
int stdin_fd = STDIN_FILENO;
int stdout_fd = STDOUT_FILENO;
unsigned char netinbuf[BUFSIZE];
size_t netinbufpos = 0;
unsigned char stdinbuf[BUFSIZE];
size_t stdinbufpos = 0;
int n, num_fds;
ssize_t ret;
/* don't read from stdin if requested */
if (dflag)
stdin_fd = -1;
/* stdin */
pfd[POLL_STDIN].fd = stdin_fd;
pfd[POLL_STDIN].events = POLLIN;
/* network out */
pfd[POLL_NETOUT].fd = net_fd;
pfd[POLL_NETOUT].events = 0;
/* network in */
pfd[POLL_NETIN].fd = net_fd;
pfd[POLL_NETIN].events = POLLIN;
/* stdout */
pfd[POLL_STDOUT].fd = stdout_fd;
pfd[POLL_STDOUT].events = 0;
while (1) {
/* both inputs are gone, buffers are empty, we are done */
if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 &&
stdinbufpos == 0 && netinbufpos == 0)
return;
/* both outputs are gone, we can't continue */
if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1)
return;
/* listen and net in gone, queues empty, done */
if (lflag && pfd[POLL_NETIN].fd == -1 &&
stdinbufpos == 0 && netinbufpos == 0)
return;
/* help says -i is for "wait between lines sent". We read and
* write arbitrary amounts of data, and we don't want to start
* scanning for newlines, so this is as good as it gets */
if (iflag)
sleep(iflag);
/* poll */
num_fds = poll(pfd, 4, timeout);
/* treat poll errors */
if (num_fds == -1)
err(1, "polling error");
/* timeout happened */
if (num_fds == 0)
return;
/* treat socket error conditions */
for (n = 0; n < 4; n++) {
if (pfd[n].revents & (POLLERR|POLLNVAL)) {
pfd[n].fd = -1;
}
}
/* reading is possible after HUP */
if (pfd[POLL_STDIN].events & POLLIN &&
pfd[POLL_STDIN].revents & POLLHUP &&
!(pfd[POLL_STDIN].revents & POLLIN))
pfd[POLL_STDIN].fd = -1;
if (pfd[POLL_NETIN].events & POLLIN &&
pfd[POLL_NETIN].revents & POLLHUP &&
!(pfd[POLL_NETIN].revents & POLLIN))
pfd[POLL_NETIN].fd = -1;
if (pfd[POLL_NETOUT].revents & POLLHUP) {
if (pfd[POLL_NETOUT].fd != -1 && Nflag)
shutdown(pfd[POLL_NETOUT].fd, SHUT_WR);
pfd[POLL_NETOUT].fd = -1;
}
/* if HUP, stop watching stdout */
if (pfd[POLL_STDOUT].revents & POLLHUP)
pfd[POLL_STDOUT].fd = -1;
/* if no net out, stop watching stdin */
if (pfd[POLL_NETOUT].fd == -1)
pfd[POLL_STDIN].fd = -1;
/* if no stdout, stop watching net in */
if (pfd[POLL_STDOUT].fd == -1) {
if (pfd[POLL_NETIN].fd != -1)
shutdown(pfd[POLL_NETIN].fd, SHUT_RD);
pfd[POLL_NETIN].fd = -1;
}
/* try to read from stdin */
if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) {
ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf,
&stdinbufpos, NULL);
if (ret == TLS_WANT_POLLIN)
pfd[POLL_STDIN].events = POLLIN;
else if (ret == TLS_WANT_POLLOUT)
pfd[POLL_STDIN].events = POLLOUT;
else if (ret == 0 || ret == -1)
pfd[POLL_STDIN].fd = -1;
/* read something - poll net out */
if (stdinbufpos > 0)
pfd[POLL_NETOUT].events = POLLOUT;
/* filled buffer - remove self from polling */
if (stdinbufpos == BUFSIZE)
pfd[POLL_STDIN].events = 0;
}
/* try to write to network */
if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) {
ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf,
&stdinbufpos, tls_ctx);
if (ret == TLS_WANT_POLLIN)
pfd[POLL_NETOUT].events = POLLIN;
else if (ret == TLS_WANT_POLLOUT)
pfd[POLL_NETOUT].events = POLLOUT;
else if (ret == -1)
pfd[POLL_NETOUT].fd = -1;
/* buffer empty - remove self from polling */
if (stdinbufpos == 0)
pfd[POLL_NETOUT].events = 0;
/* buffer no longer full - poll stdin again */
if (stdinbufpos < BUFSIZE)
pfd[POLL_STDIN].events = POLLIN;
}
/* try to read from network */
if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) {
ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf,
&netinbufpos, tls_ctx);
if (ret == TLS_WANT_POLLIN)
pfd[POLL_NETIN].events = POLLIN;
else if (ret == TLS_WANT_POLLOUT)
pfd[POLL_NETIN].events = POLLOUT;
else if (ret == -1)
pfd[POLL_NETIN].fd = -1;
/* eof on net in - remove from pfd */
if (ret == 0) {
shutdown(pfd[POLL_NETIN].fd, SHUT_RD);
pfd[POLL_NETIN].fd = -1;
}
if (recvlimit > 0 && ++recvcount >= recvlimit) {
if (pfd[POLL_NETIN].fd != -1)
shutdown(pfd[POLL_NETIN].fd, SHUT_RD);
pfd[POLL_NETIN].fd = -1;
pfd[POLL_STDIN].fd = -1;
}
/* read something - poll stdout */
if (netinbufpos > 0)
pfd[POLL_STDOUT].events = POLLOUT;
/* filled buffer - remove self from polling */
if (netinbufpos == BUFSIZE)
pfd[POLL_NETIN].events = 0;
/* handle telnet */
if (pfd[POLL_NETIN].fd != -1 && tflag)
atelnet(pfd[POLL_NETIN].fd, netinbuf,
netinbufpos);
}
/* try to write to stdout */
if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) {
ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf,
&netinbufpos, NULL);
if (ret == TLS_WANT_POLLIN)
pfd[POLL_STDOUT].events = POLLIN;
else if (ret == TLS_WANT_POLLOUT)
pfd[POLL_STDOUT].events = POLLOUT;
else if (ret == -1)
pfd[POLL_STDOUT].fd = -1;
/* buffer empty - remove self from polling */
if (netinbufpos == 0)
pfd[POLL_STDOUT].events = 0;
/* buffer no longer full - poll net in again */
if (netinbufpos < BUFSIZE)
pfd[POLL_NETIN].events = POLLIN;
}
/* stdin gone and queue empty? */
if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) {
if (pfd[POLL_NETOUT].fd != -1 && Nflag)
shutdown(pfd[POLL_NETOUT].fd, SHUT_WR);
pfd[POLL_NETOUT].fd = -1;
}
/* net in gone and queue empty? */
if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) {
pfd[POLL_STDOUT].fd = -1;
}
}
}
ssize_t
drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls)
{
ssize_t n;
ssize_t adjust;
if (fd == -1)
return -1;
if (tls) {
n = tls_write(tls, buf, *bufpos);
if (n == -1)
errx(1, "tls write failed (%s)", tls_error(tls));
} else {
n = write(fd, buf, *bufpos);
/* don't treat EAGAIN, EINTR as error */
if (n == -1 && (errno == EAGAIN || errno == EINTR))
n = TLS_WANT_POLLOUT;
}
if (n <= 0)
return n;
/* adjust buffer */
adjust = *bufpos - n;
if (adjust > 0)
memmove(buf, buf + n, adjust);
*bufpos -= n;
return n;
}
ssize_t
fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls)
{
size_t num = BUFSIZE - *bufpos;
ssize_t n;
if (fd == -1)
return -1;
if (tls) {
n = tls_read(tls, buf + *bufpos, num);
if (n == -1)
errx(1, "tls read failed (%s)", tls_error(tls));
} else {
n = read(fd, buf + *bufpos, num);
/* don't treat EAGAIN, EINTR as error */
if (n == -1 && (errno == EAGAIN || errno == EINTR))
n = TLS_WANT_POLLIN;
}
if (n <= 0)
return n;
*bufpos += n;
return n;
}
/*
* fdpass()
* Pass the connected file descriptor to stdout and exit.
*/
void
fdpass(int nfd)
{
struct msghdr mh;
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(int))];
} cmsgbuf;
struct cmsghdr *cmsg;
struct iovec iov;
char c = '\0';
ssize_t r;
struct pollfd pfd;
/* Avoid obvious stupidity */
if (isatty(STDOUT_FILENO))
errx(1, "Cannot pass file descriptor to tty");
memset(&mh, 0, sizeof(mh));
memset(&cmsgbuf, 0, sizeof(cmsgbuf));
memset(&iov, 0, sizeof(iov));
mh.msg_control = (caddr_t)&cmsgbuf.buf;
mh.msg_controllen = sizeof(cmsgbuf.buf);
cmsg = CMSG_FIRSTHDR(&mh);
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = nfd;
iov.iov_base = &c;
iov.iov_len = 1;
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
memset(&pfd, 0, sizeof(pfd));
pfd.fd = STDOUT_FILENO;
pfd.events = POLLOUT;
for (;;) {
r = sendmsg(STDOUT_FILENO, &mh, 0);
if (r == -1) {
if (errno == EAGAIN || errno == EINTR) {
if (poll(&pfd, 1, -1) == -1)
err(1, "poll");
continue;
}
err(1, "sendmsg");
} else if (r != 1)
errx(1, "sendmsg: unexpected return value %zd", r);
else
break;
}
exit(0);
}
/* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */
void
atelnet(int nfd, unsigned char *buf, unsigned int size)
{
unsigned char *p, *end;
unsigned char obuf[4];
if (size < 3)
return;
end = buf + size - 2;
for (p = buf; p < end; p++) {
if (*p != IAC)
continue;
obuf[0] = IAC;
p++;
if ((*p == WILL) || (*p == WONT))
obuf[1] = DONT;
else if ((*p == DO) || (*p == DONT))
obuf[1] = WONT;
else
continue;
p++;
obuf[2] = *p;
if (atomicio(vwrite, nfd, obuf, 3) != 3)
warn("Write Error!");
}
}
int
strtoport(char *portstr, int udp)
{
struct servent *entry;
const char *errstr;
char *proto;
int port = -1;
proto = udp ? "udp" : "tcp";
port = strtonum(portstr, 1, PORT_MAX, &errstr);
if (errstr == NULL)
return port;
if (errno != EINVAL)
errx(1, "port number %s: %s", errstr, portstr);
if ((entry = getservbyname(portstr, proto)) == NULL)
errx(1, "service \"%s\" unknown", portstr);
return ntohs(entry->s_port);
}
/*
* build_ports()
* Build an array of ports in portlist[], listing each port
* that we should try to connect to.
*/
void
build_ports(char *p)
{
char *n;
int hi, lo, cp;
int x = 0;
if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) {
*n = '\0';
n++;
/* Make sure the ports are in order: lowest->highest. */
hi = strtoport(n, uflag);
lo = strtoport(p, uflag);
if (lo > hi) {
cp = hi;
hi = lo;
lo = cp;
}
/*
* Initialize portlist with a random permutation. Based on
* Knuth, as in ip_randomid() in sys/netinet/ip_id.c.
*/
if (rflag) {
for (x = 0; x <= hi - lo; x++) {
cp = arc4random_uniform(x + 1);
portlist[x] = portlist[cp];
if (asprintf(&portlist[cp], "%d", x + lo) == -1)
err(1, "asprintf");
}
} else { /* Load ports sequentially. */
for (cp = lo; cp <= hi; cp++) {
if (asprintf(&portlist[x], "%d", cp) == -1)
err(1, "asprintf");
x++;
}
}
} else {
char *tmp;
hi = strtoport(p, uflag);
if (asprintf(&tmp, "%d", hi) != -1)
portlist[0] = tmp;
else
err(1, NULL);
}
}
/*
* udptest()
* Do a few writes to see if the UDP port is there.
* Fails once PF state table is full.
*/
int
udptest(int s)
{
int i, ret;
/* Only write to the socket in scan mode or interactive mode. */
if (!zflag && !isatty(STDIN_FILENO))
return 0;
for (i = 0; i <= 3; i++) {
if (write(s, "X", 1) == 1)
ret = 1;
else
ret = -1;
}
return ret;
}
void
connection_info(const char *host, const char *port, const char *proto,
const char *ipaddr)
{
struct servent *sv;
char *service = "*";
/* Look up service name unless -n. */
if (!nflag) {
sv = getservbyport(ntohs(atoi(port)), proto);
if (sv != NULL)
service = sv->s_name;
}
fprintf(stderr, "Connection to %s", host);
/*
* if we aren't connecting thru a proxy and
* there is something to report, print IP
*/
if (!nflag && !xflag && strcmp(host, ipaddr) != 0)
fprintf(stderr, " (%s)", ipaddr);
fprintf(stderr, " %s port [%s/%s] succeeded!\n", port, proto, service);
}
void
set_common_sockopts(int s, int af)
{
int x = 1;
if (Sflag) {
if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG,
&x, sizeof(x)) == -1)
err(1, NULL);
}
if (Dflag) {
if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
&x, sizeof(x)) == -1)
err(1, NULL);
}
if (Tflag != -1) {
if (af == AF_INET && setsockopt(s, IPPROTO_IP,
IP_TOS, &Tflag, sizeof(Tflag)) == -1)
err(1, "set IP ToS");
else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6,
IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1)
err(1, "set IPv6 traffic class");
}
if (Iflag) {
if (setsockopt(s, SOL_SOCKET, SO_RCVBUF,
&Iflag, sizeof(Iflag)) == -1)
err(1, "set TCP receive buffer size");
}
if (Oflag) {
if (setsockopt(s, SOL_SOCKET, SO_SNDBUF,
&Oflag, sizeof(Oflag)) == -1)
err(1, "set TCP send buffer size");
}
if (ttl != -1) {
if (af == AF_INET && setsockopt(s, IPPROTO_IP,
IP_TTL, &ttl, sizeof(ttl)))
err(1, "set IP TTL");
else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6,
IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)))
err(1, "set IPv6 unicast hops");
}
if (minttl != -1) {
if (af == AF_INET && setsockopt(s, IPPROTO_IP,
IP_MINTTL, &minttl, sizeof(minttl)))
err(1, "set IP min TTL");
else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6,
IPV6_MINHOPCOUNT, &minttl, sizeof(minttl)))
err(1, "set IPv6 min hop count");
}
}
int
process_tos_opt(char *s, int *val)
{
/* DiffServ Codepoints and other TOS mappings */
const struct toskeywords {
const char *keyword;
int val;
} *t, toskeywords[] = {
{ "af11", IPTOS_DSCP_AF11 },
{ "af12", IPTOS_DSCP_AF12 },
{ "af13", IPTOS_DSCP_AF13 },
{ "af21", IPTOS_DSCP_AF21 },
{ "af22", IPTOS_DSCP_AF22 },
{ "af23", IPTOS_DSCP_AF23 },
{ "af31", IPTOS_DSCP_AF31 },
{ "af32", IPTOS_DSCP_AF32 },
{ "af33", IPTOS_DSCP_AF33 },
{ "af41", IPTOS_DSCP_AF41 },
{ "af42", IPTOS_DSCP_AF42 },
{ "af43", IPTOS_DSCP_AF43 },
{ "critical", IPTOS_PREC_CRITIC_ECP },
{ "cs0", IPTOS_DSCP_CS0 },
{ "cs1", IPTOS_DSCP_CS1 },
{ "cs2", IPTOS_DSCP_CS2 },
{ "cs3", IPTOS_DSCP_CS3 },
{ "cs4", IPTOS_DSCP_CS4 },
{ "cs5", IPTOS_DSCP_CS5 },
{ "cs6", IPTOS_DSCP_CS6 },
{ "cs7", IPTOS_DSCP_CS7 },
{ "ef", IPTOS_DSCP_EF },
{ "inetcontrol", IPTOS_PREC_INTERNETCONTROL },
{ "lowdelay", IPTOS_LOWDELAY },
{ "netcontrol", IPTOS_PREC_NETCONTROL },
{ "reliability", IPTOS_RELIABILITY },
{ "throughput", IPTOS_THROUGHPUT },
{ NULL, -1 },
};
for (t = toskeywords; t->keyword != NULL; t++) {
if (strcmp(s, t->keyword) == 0) {
*val = t->val;
return 1;
}
}
return 0;
}
int
process_tls_opt(char *s, int *flags)
{
size_t len;
char *v;
const struct tlskeywords {
const char *keyword;
int flag;
char **value;
} *t, tlskeywords[] = {
{ "ciphers", -1, &tls_ciphers },
{ "clientcert", TLS_CCERT, NULL },
{ "muststaple", TLS_MUSTSTAPLE, NULL },
{ "noverify", TLS_NOVERIFY, NULL },
{ "noname", TLS_NONAME, NULL },
{ "protocols", -1, &tls_protocols },
{ NULL, -1, NULL },
};
len = strlen(s);
if ((v = strchr(s, '=')) != NULL) {
len = v - s;
v++;
}
for (t = tlskeywords; t->keyword != NULL; t++) {
if (strlen(t->keyword) == len &&
strncmp(s, t->keyword, len) == 0) {
if (t->value != NULL) {
if (v == NULL)
errx(1, "invalid tls value `%s'", s);
*t->value = v;
} else {
*flags |= t->flag;
}
return 1;
}
}
return 0;
}
void
save_peer_cert(struct tls *tls_ctx, FILE *fp)
{
const char *pem;
size_t plen;
if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL)
errx(1, "Can't get peer certificate");
if (fprintf(fp, "%.*s", (int)plen, pem) < 0)
err(1, "unable to save peer cert");
if (fflush(fp) != 0)
err(1, "unable to flush peer cert");
}
void
report_tls(struct tls *tls_ctx, char *host)
{
time_t t;
const char *ocsp_url;
fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n",
tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host);
fprintf(stderr, "Peer name: %s\n",
tls_expectname ? tls_expectname : host);
if (tls_peer_cert_subject(tls_ctx))
fprintf(stderr, "Subject: %s\n",
tls_peer_cert_subject(tls_ctx));
if (tls_peer_cert_issuer(tls_ctx))
fprintf(stderr, "Issuer: %s\n",
tls_peer_cert_issuer(tls_ctx));
if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1)
fprintf(stderr, "Valid From: %s", ctime(&t));
if ((t = tls_peer_cert_notafter(tls_ctx)) != -1)
fprintf(stderr, "Valid Until: %s", ctime(&t));
if (tls_peer_cert_hash(tls_ctx))
fprintf(stderr, "Cert Hash: %s\n",
tls_peer_cert_hash(tls_ctx));
ocsp_url = tls_peer_ocsp_url(tls_ctx);
if (ocsp_url != NULL)
fprintf(stderr, "OCSP URL: %s\n", ocsp_url);
switch (tls_peer_ocsp_response_status(tls_ctx)) {
case TLS_OCSP_RESPONSE_SUCCESSFUL:
fprintf(stderr, "OCSP Stapling: %s\n",
tls_peer_ocsp_result(tls_ctx) == NULL ? "" :
tls_peer_ocsp_result(tls_ctx));
fprintf(stderr,
" response_status=%d cert_status=%d crl_reason=%d\n",
tls_peer_ocsp_response_status(tls_ctx),
tls_peer_ocsp_cert_status(tls_ctx),
tls_peer_ocsp_crl_reason(tls_ctx));
t = tls_peer_ocsp_this_update(tls_ctx);
fprintf(stderr, " this update: %s",
t != -1 ? ctime(&t) : "\n");
t = tls_peer_ocsp_next_update(tls_ctx);
fprintf(stderr, " next update: %s",
t != -1 ? ctime(&t) : "\n");
t = tls_peer_ocsp_revocation_time(tls_ctx);
fprintf(stderr, " revocation: %s",
t != -1 ? ctime(&t) : "\n");
break;
case -1:
break;
default:
fprintf(stderr,
"OCSP Stapling: failure - response_status %d (%s)\n",
tls_peer_ocsp_response_status(tls_ctx),
tls_peer_ocsp_result(tls_ctx) == NULL ? "" :
tls_peer_ocsp_result(tls_ctx));
break;
}
}
void
report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen,
char *path)
{
char host[NI_MAXHOST], port[NI_MAXSERV];
int herr;
int flags = NI_NUMERICSERV;
if (path != NULL) {
fprintf(stderr, "%s on %s\n", msg, path);
return;
}
if (nflag)
flags |= NI_NUMERICHOST;
herr = getnameinfo(sa, salen, host, sizeof(host), port, sizeof(port),
flags);
switch (herr) {
case 0:
break;
case EAI_SYSTEM:
err(1, "getnameinfo");
default:
errx(1, "getnameinfo: %s", gai_strerror(herr));
}
fprintf(stderr, "%s on %s %s\n", msg, host, port);
}
void
help(void)
{
usage(0);
fprintf(stderr, "\tCommand Summary:\n\
\t-4 Use IPv4\n\
\t-6 Use IPv6\n\
\t-C certfile Public key file\n\
\t-c Use TLS\n\
\t-D Enable the debug socket option\n\
\t-d Detach from stdin\n\
\t-e name\t Required name in peer certificate\n\
\t-F Pass socket fd\n\
\t-H hash\t Hash string of peer certificate\n\
\t-h This help text\n\
\t-I length TCP receive buffer length\n\
\t-i interval Delay interval for lines sent, ports scanned\n\
\t-K keyfile Private key file\n\
\t-k Keep inbound sockets open for multiple connects\n\
\t-l Listen mode, for inbound connects\n\
\t-M ttl Outgoing TTL / Hop Limit\n\
\t-m minttl Minimum incoming TTL / Hop Limit\n\
\t-N Shutdown the network socket after EOF on stdin\n\
\t-n Suppress name/port resolutions\n\
\t-O length TCP send buffer length\n\
\t-o staplefile Staple file\n\
\t-P proxyuser\tUsername for proxy authentication\n\
\t-p port\t Specify local port for remote connects\n\
\t-R CAfile CA bundle\n\
\t-r Randomize remote ports\n\
\t-S Enable the TCP MD5 signature option\n\
\t-s sourceaddr Local source address\n\
\t-T keyword TOS value or TLS options\n\
\t-t Answer TELNET negotiation\n\
\t-U Use UNIX domain socket\n\
\t-u UDP mode\n\
\t-V rtable Specify alternate routing table\n\
\t-v Verbose\n\
\t-W recvlimit Terminate after receiving a number of packets\n\
\t-w timeout Timeout for connects and final net reads\n\
\t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\
\t-x addr[:port]\tSpecify proxy address and port\n\
\t-Z Peer certificate file\n\
\t-z Zero-I/O mode [used for scanning]\n\
Port numbers can be individual or ranges: lo-hi [inclusive]\n");
exit(1);
}
void
usage(int ret)
{
fprintf(stderr,
"usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] "
"[-H hash] [-I length]\n"
"\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n"
"\t [-o staplefile] [-P proxy_username] [-p source_port] "
"[-R CAfile]\n"
"\t [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit] "
"[-w timeout]\n"
"\t [-X proxy_protocol] [-x proxy_address[:port]] "
"[-Z peercertfile]\n"
"\t [destination] [port]\n");
if (ret)
exit(1);
}
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