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Diff for /src/usr.bin/ssh/channels.c between version 1.109 and 1.109.2.5

version 1.109, 2001/04/17 12:55:03

version 1.109.2.5, 2002/03/09 00:20:44

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* incompatible with the protocol description in the RFC file, it must be

* called by a name other than "ssh" or "Secure Shell".

* SSH2 support added by Markus Friedl.

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#include "includes.h"

RCSID("$OpenBSD$");

#include <openssl/rsa.h>

#include <openssl/dsa.h>

#include "ssh.h"

#include "ssh1.h"

#include "ssh2.h"

#include "packet.h"

#include "xmalloc.h"

#include "buffer.h"

#include "bufaux.h"

#include "uidswap.h"

#include "log.h"

#include "misc.h"

#include "channels.h"

#include "nchan.h"

#include "compat.h"

#include "canohost.h"

#include "key.h"

#include "authfd.h"

#include "pathnames.h"

/* Maximum number of fake X11 displays to try. */

#define MAX_DISPLAYS 1000

/* Max len of agent socket */

/* -- channel core */

#define MAX_SOCKET_NAME 100

* Pointer to an array containing all allocated channels. The array is

* dynamically extended as needed.

static Channel *channels = NULL;

static Channel **channels = NULL;

* Size of the channel array. All slots of the array must always be

* initialized (at least the type field); unused slots are marked with type

* initialized (at least the type field); unused slots set to NULL

* SSH_CHANNEL_FREE.

static int channels_alloc = 0;

* Maximum file descriptor value used in any of the channels. This is

* updated in channel_allocate.

* updated in channel_new.

static int channel_max_fd = 0;

/* Name and directory of socket for authentication agent forwarding. */

static char *channel_forwarded_auth_socket_name = NULL;

static char *channel_forwarded_auth_socket_dir = NULL;

/* Saved X11 authentication protocol name. */

/* -- tcp forwarding */

char *x11_saved_proto = NULL;

/* Saved X11 authentication data. This is the real data. */

char *x11_saved_data = NULL;

u_int x11_saved_data_len = 0;

* Fake X11 authentication data. This is what the server will be sending us;

* we should replace any occurrences of this by the real data.

char *x11_fake_data = NULL;

u_int x11_fake_data_len;

* Data structure for storing which hosts are permitted for forward requests.

* The local sides of any remote forwards are stored in this array to prevent

* a corrupt remote server from accessing arbitrary TCP/IP ports on our local

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/* List of all permitted host/port pairs to connect. */

static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];

/* Number of permitted host/port pairs in the array. */

static int num_permitted_opens = 0;

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static int all_opens_permitted = 0;

/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */

static int have_hostname_in_open = 0;

/* AF_UNSPEC or AF_INET or AF_INET6 */

/* -- X11 forwarding */

extern int IPv4or6;

void port_open_helper(Channel *c, char *rtype);

/* Maximum number of fake X11 displays to try. */

#define MAX_DISPLAYS 1000

/* Sets specific protocol options. */

/* Saved X11 authentication protocol name. */

static char *x11_saved_proto = NULL;

void

/* Saved X11 authentication data. This is the real data. */

channel_set_options(int hostname_in_open)

static char *x11_saved_data = NULL;

{

static u_int x11_saved_data_len = 0;

have_hostname_in_open = hostname_in_open;

}

/* lookup channel by id */

* Fake X11 authentication data. This is what the server will be sending us;

* we should replace any occurrences of this by the real data.

static char *x11_fake_data = NULL;

static u_int x11_fake_data_len;

/* -- agent forwarding */

#define NUM_SOCKS 10

/* Name and directory of socket for authentication agent forwarding. */

static char *auth_sock_name = NULL;

static char *auth_sock_dir = NULL;

/* AF_UNSPEC or AF_INET or AF_INET6 */

static int IPv4or6 = AF_UNSPEC;

/* helper */

static void port_open_helper(Channel *c, char *rtype);

/* -- channel core */

Channel *

channel_lookup(int id)

{

Channel *c;

if (id < 0 || id > channels_alloc) {

if (id < 0 || id >= channels_alloc) {

log("channel_lookup: %d: bad id", id);

return NULL;

}

c = &channels[id];

c = channels[id];

if (c->type == SSH_CHANNEL_FREE) {

if (c == NULL) {

log("channel_lookup: %d: bad id: channel free", id);

return NULL;

}

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* when the channel consumer/producer is ready, e.g. shell exec'd

void

static void

channel_register_fds(Channel *c, int rfd, int wfd, int efd,

int extusage, int nonblock)

{

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* remote_name to be freed.

int

Channel *

channel_new(char *ctype, int type, int rfd, int wfd, int efd,

int window, int maxpack, int extusage, char *remote_name, int nonblock)

{

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/* Do initial allocation if this is the first call. */

if (channels_alloc == 0) {

chan_init();

channels_alloc = 10;

channels = xmalloc(channels_alloc * sizeof(Channel));

channels = xmalloc(channels_alloc * sizeof(Channel *));

for (i = 0; i < channels_alloc; i++)

channels[i].type = SSH_CHANNEL_FREE;

channels[i] = NULL;

fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);

* Kludge: arrange a call to channel_stop_listening if we

* terminate with fatal().

fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);

}

/* Try to find a free slot where to put the new channel. */

for (found = -1, i = 0; i < channels_alloc; i++)

if (channels[i].type == SSH_CHANNEL_FREE) {

if (channels[i] == NULL) {

/* Found a free slot. */

found = i;

break;

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found = channels_alloc;

channels_alloc += 10;

debug2("channel: expanding %d", channels_alloc);

channels = xrealloc(channels, channels_alloc * sizeof(Channel));

channels = xrealloc(channels, channels_alloc * sizeof(Channel *));

for (i = found; i < channels_alloc; i++)

channels[i].type = SSH_CHANNEL_FREE;

channels[i] = NULL;

}

/* Initialize and return new channel number. */

/* Initialize and return new channel. */

c = &channels[found];

c = channels[found] = xmalloc(sizeof(Channel));

memset(c, 0, sizeof(Channel));

buffer_init(&c->input);

buffer_init(&c->output);

buffer_init(&c->extended);

chan_init_iostates(c);

c->ostate = CHAN_OUTPUT_OPEN;

c->istate = CHAN_INPUT_OPEN;

c->flags = 0;

channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);

c->self = found;

c->type = type;

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c->remote_name = remote_name;

c->remote_window = 0;

c->remote_maxpacket = 0;

c->cb_fn = NULL;

c->force_drain = 0;

c->cb_arg = NULL;

c->single_connection = 0;

c->cb_event = 0;

c->detach_user = NULL;

c->dettach_user = NULL;

c->confirm = NULL;

c->input_filter = NULL;

debug("channel %d: new [%s]", found, remote_name);

return found;

return c;

}

/* old interface XXX */

int

static int

channel_allocate(int type, int sock, char *remote_name)

channel_find_maxfd(void)

{

return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);

int i, max = 0;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c != NULL) {

max = MAX(max, c->rfd);

max = MAX(max, c->wfd);

max = MAX(max, c->efd);

}

return max;

}

int

channel_close_fd(int *fdp)

{

int ret = 0, fd = *fdp;

if (fd != -1) {

ret = close(fd);

*fdp = -1;

if (fd == channel_max_fd)

channel_max_fd = channel_find_maxfd();

}

return ret;

}

/* Close all channel fd/socket. */

void

static void

channel_close_fds(Channel *c)

{

if (c->sock != -1) {

debug3("channel_close_fds: channel %d: r %d w %d e %d",

close(c->sock);

c->self, c->rfd, c->wfd, c->efd);

c->sock = -1;

}

channel_close_fd(&c->sock);

if (c->rfd != -1) {

channel_close_fd(&c->rfd);

close(c->rfd);

channel_close_fd(&c->wfd);

c->rfd = -1;

channel_close_fd(&c->efd);

}

if (c->wfd != -1) {

close(c->wfd);

c->wfd = -1;

}

if (c->efd != -1) {

close(c->efd);

c->efd = -1;

}

/* Free the channel and close its fd/socket. */

void

channel_free(int id)

channel_free(Channel *c)

{

Channel *c = channel_lookup(id);

char *s;

char *s = channel_open_message();

int i, n;

if (c == NULL)

for (n = 0, i = 0; i < channels_alloc; i++)

packet_disconnect("channel free: bad local channel %d", id);

if (channels[i])

debug("channel_free: channel %d: status: %s", id, s);

n++;

debug("channel_free: channel %d: %s, nchannels %d", c->self,

c->remote_name ? c->remote_name : "???", n);

s = channel_open_message();

debug3("channel_free: status: %s", s);

xfree(s);

if (c->dettach_user != NULL) {

debug("channel_free: channel %d: dettaching channel user", id);

c->dettach_user(c->self, NULL);

}

if (c->sock != -1)

shutdown(c->sock, SHUT_RDWR);

channel_close_fds(c);

buffer_free(&c->input);

buffer_free(&c->output);

buffer_free(&c->extended);

c->type = SSH_CHANNEL_FREE;

if (c->remote_name) {

xfree(c->remote_name);

c->remote_name = NULL;

}

channels[c->self] = NULL;

xfree(c);

}

void

channel_free_all(void)

{

int i;

for (i = 0; i < channels_alloc; i++)

if (channels[i] != NULL)

channel_free(channels[i]);

}

* Closes the sockets/fds of all channels. This is used to close extra file

* descriptors after a fork.

void

channel_close_all(void)

{

int i;

for (i = 0; i < channels_alloc; i++)

if (channels[i] != NULL)

channel_close_fds(channels[i]);

}

* Stop listening to channels.

void

channel_stop_listening(void)

{

int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c != NULL) {

switch (c->type) {

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_X11_LISTENER:

channel_close_fd(&c->sock);

channel_free(c);

break;

}

* Returns true if no channel has too much buffered data, and false if one or

* more channel is overfull.

int

channel_not_very_much_buffered_data(void)

{

u_int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c != NULL && c->type == SSH_CHANNEL_OPEN) {

#if 0

if (!compat20 &&

buffer_len(&c->input) > packet_get_maxsize()) {

debug("channel %d: big input buffer %d",

c->self, buffer_len(&c->input));

return 0;

}

#endif

if (buffer_len(&c->output) > packet_get_maxsize()) {

debug("channel %d: big output buffer %d > %d",

c->self, buffer_len(&c->output),

packet_get_maxsize());

return 0;

}

return 1;

}

/* Returns true if any channel is still open. */

int

channel_still_open(void)

{

int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c == NULL)

continue;

switch (c->type) {

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_CONNECTING:

case SSH_CHANNEL_ZOMBIE:

continue;

case SSH_CHANNEL_LARVAL:

if (!compat20)

fatal("cannot happen: SSH_CHANNEL_LARVAL");

continue;

case SSH_CHANNEL_OPENING:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

return 1;

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

if (!compat13)

fatal("cannot happen: OUT_DRAIN");

return 1;

default:

fatal("channel_still_open: bad channel type %d", c->type);

/* NOTREACHED */

}

return 0;

}

/* Returns the id of an open channel suitable for keepaliving */

int

channel_find_open(void)

{

int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c == NULL)

continue;

switch (c->type) {

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_OPENING:

case SSH_CHANNEL_CONNECTING:

case SSH_CHANNEL_ZOMBIE:

continue;

case SSH_CHANNEL_LARVAL:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

return i;

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

if (!compat13)

fatal("cannot happen: OUT_DRAIN");

return i;

default:

fatal("channel_find_open: bad channel type %d", c->type);

/* NOTREACHED */

}

return -1;

}

* Returns a message describing the currently open forwarded connections,

* suitable for sending to the client. The message contains crlf pairs for

* newlines.

char *

channel_open_message(void)

{

Buffer buffer;

Channel *c;

char buf[1024], *cp;

int i;

buffer_init(&buffer);

snprintf(buf, sizeof buf, "The following connections are open:\r\n");

buffer_append(&buffer, buf, strlen(buf));

for (i = 0; i < channels_alloc; i++) {

c = channels[i];

if (c == NULL)

continue;

switch (c->type) {

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_ZOMBIE:

continue;

case SSH_CHANNEL_LARVAL:

case SSH_CHANNEL_OPENING:

case SSH_CHANNEL_CONNECTING:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",

c->self, c->remote_name,

c->type, c->remote_id,

c->istate, buffer_len(&c->input),

c->ostate, buffer_len(&c->output),

c->rfd, c->wfd);

buffer_append(&buffer, buf, strlen(buf));

continue;

default:

fatal("channel_open_message: bad channel type %d", c->type);

/* NOTREACHED */

}

buffer_append(&buffer, "\0", 1);

cp = xstrdup(buffer_ptr(&buffer));

buffer_free(&buffer);

return cp;

}

void

channel_send_open(int id)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_send_open: %d: bad id", id);

return;

}

debug("send channel open %d", id);

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring(c->ctype);

packet_put_int(c->self);

packet_put_int(c->local_window);

packet_put_int(c->local_maxpacket);

packet_send();

}

void

channel_request_start(int local_id, char *service, int wantconfirm)

{

Channel *c = channel_lookup(local_id);

if (c == NULL) {

log("channel_request_start: %d: unknown channel id", local_id);

return;

}

debug("channel request %d: %s", local_id, service) ;

packet_start(SSH2_MSG_CHANNEL_REQUEST);

packet_put_int(c->remote_id);

packet_put_cstring(service);

packet_put_char(wantconfirm);

}

void

channel_register_confirm(int id, channel_callback_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_comfirm: %d: bad id", id);

return;

}

c->confirm = fn;

}

void

channel_register_cleanup(int id, channel_callback_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_cleanup: %d: bad id", id);

return;

}

c->detach_user = fn;

}

void

channel_cancel_cleanup(int id)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_cancel_cleanup: %d: bad id", id);

return;

}

c->detach_user = NULL;

}

void

channel_register_filter(int id, channel_filter_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_filter: %d: bad id", id);

return;

}

c->input_filter = fn;

}

void

channel_set_fds(int id, int rfd, int wfd, int efd,

int extusage, int nonblock, u_int window_max)

{

Channel *c = channel_lookup(id);

if (c == NULL || c->type != SSH_CHANNEL_LARVAL)

fatal("channel_activate for non-larval channel %d.", id);

channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);

c->type = SSH_CHANNEL_OPEN;

c->local_window = c->local_window_max = window_max;

packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);

packet_put_int(c->remote_id);

packet_put_int(c->local_window);

packet_send();

}

* 'channel_pre*' are called just before select() to add any bits relevant to

* channels in the select bitmasks.

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chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];

chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];

void

static void

channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)

{

FD_SET(c->sock, readset);

}

void

static void

channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)

{

debug3("channel %d: waiting for connection", c->self);

FD_SET(c->sock, writeset);

}

void

static void

channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)

{

if (buffer_len(&c->input) < packet_get_maxsize())

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FD_SET(c->sock, writeset);

}

void

static void

channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)

channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)

{

/* test whether sockets are 'alive' for read/write */

u_int limit = compat20 ? c->remote_window : packet_get_maxsize();

if (c->istate == CHAN_INPUT_OPEN)

if (buffer_len(&c->input) < packet_get_maxsize())

FD_SET(c->sock, readset);

if (c->ostate == CHAN_OUTPUT_OPEN ||

c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {

if (buffer_len(&c->output) > 0) {

FD_SET(c->sock, writeset);

} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {

chan_obuf_empty(c);

}

void

channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)

{

if (c->istate == CHAN_INPUT_OPEN &&

c->remote_window > 0 &&

limit > 0 &&

buffer_len(&c->input) < c->remote_window)

buffer_len(&c->input) < limit)

FD_SET(c->rfd, readset);

if (c->ostate == CHAN_OUTPUT_OPEN ||

c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {

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}

/** XXX check close conditions, too */

if (c->efd != -1) {

if (compat20 && c->efd != -1) {

if (c->extended_usage == CHAN_EXTENDED_WRITE &&

buffer_len(&c->extended) > 0)

FD_SET(c->efd, writeset);

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}

void

static void

channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)

{

if (buffer_len(&c->input) == 0) {

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}

void

static void

channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)

{

if (buffer_len(&c->output) == 0)

channel_free(c->self);

chan_mark_dead(c);

else

FD_SET(c->sock, writeset);

}

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* data in that packet is then substituted by the real data if it matches the

* fake data, and the channel is put into normal mode.

* XXX All this happens at the client side.

* Returns: 0 = need more data, -1 = wrong cookie, 1 = ok

int

static int

x11_open_helper(Channel *c)

x11_open_helper(Buffer *b)

{

u_char *ucp;

u_int proto_len, data_len;

/* Check if the fixed size part of the packet is in buffer. */

if (buffer_len(&c->output) < 12)

if (buffer_len(b) < 12)

return 0;

/* Parse the lengths of variable-length fields. */

ucp = (u_char *) buffer_ptr(&c->output);

ucp = buffer_ptr(b);

if (ucp[0] == 0x42) { /* Byte order MSB first. */

proto_len = 256 * ucp[6] + ucp[7];

data_len = 256 * ucp[8] + ucp[9];

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data_len = ucp[8] + 256 * ucp[9];

} else {

debug("Initial X11 packet contains bad byte order byte: 0x%x",

ucp[0]);

return -1;

}

/* Check if the whole packet is in buffer. */

if (buffer_len(&c->output) <

if (buffer_len(b) <

12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))

return 0;

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return 1;

}

void

static void

channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)

{

int ret = x11_open_helper(c);

int ret = x11_open_helper(&c->output);

if (ret == 1) {

/* Start normal processing for the channel. */

c->type = SSH_CHANNEL_OPEN;

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log("X11 connection rejected because of wrong authentication.");

buffer_clear(&c->input);

buffer_clear(&c->output);

close(c->sock);

channel_close_fd(&c->sock);

c->sock = -1;

c->type = SSH_CHANNEL_CLOSED;

packet_start(SSH_MSG_CHANNEL_CLOSE);

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}

void

static void

channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)

{

int ret = x11_open_helper(c);

int ret = x11_open_helper(&c->output);

/* c->force_drain = 1; */

if (ret == 1) {

c->type = SSH_CHANNEL_OPEN;

if (compat20)

channel_pre_open(c, readset, writeset);

channel_pre_open_20(c, readset, writeset);

else

channel_pre_open_15(c, readset, writeset);

} else if (ret == -1) {

log("X11 connection rejected because of wrong authentication.");

debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);

chan_read_failed(c); /** force close? */

chan_read_failed(c);

chan_write_failed(c);

buffer_clear(&c->input);

chan_ibuf_empty(c);

buffer_clear(&c->output);

/* for proto v1, the peer will send an IEOF */

if (compat20)

chan_write_failed(c);

else

c->type = SSH_CHANNEL_OPEN;

debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);

}

/* try to decode a socks4 header */

int

static int

channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)

{

u_char *p, *host;

int len, have, i, found;

char username[256];

struct {

u_int8_t version;

u_int8_t command;

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host = inet_ntoa(s4_req.dest_addr);

strlcpy(c->path, host, sizeof(c->path));

c->host_port = ntohs(s4_req.dest_port);

debug("channel %d: dynamic request: socks4 host %s port %u command %u",

c->self, host, c->host_port, s4_req.command);

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}

/* dynamic port forwarding */

void

static void

channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)

{

u_char *p;

int have, ret;

have = buffer_len(&c->input);

c->delayed = 0;

debug2("channel %d: pre_dynamic: have %d", c->self, have);

/* buffer_dump(&c->input); */

/* check if the fixed size part of the packet is in buffer. */

Line 640

Line 957

break;

}

if (ret < 0) {

channel_free(c->self);

chan_mark_dead(c);

} else if (ret == 0) {

debug2("channel %d: pre_dynamic: need more", c->self);

/* need more */

Line 653

Line 970

}

/* This is our fake X11 server socket. */

void

static void

channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)

{

Channel *nc;

struct sockaddr addr;

int newsock, newch;

int newsock;

socklen_t addrlen;

char buf[16384], *remote_ipaddr;

int remote_port;

Line 666

Line 984

debug("X11 connection requested.");

addrlen = sizeof(addr);

newsock = accept(c->sock, &addr, &addrlen);

if (c->single_connection) {

debug("single_connection: closing X11 listener.");

channel_close_fd(&c->sock);

chan_mark_dead(c);

}

if (newsock < 0) {

error("accept: %.100s", strerror(errno));

return;

}

set_nodelay(newsock);

remote_ipaddr = get_peer_ipaddr(newsock);

remote_port = get_peer_port(newsock);

snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",

remote_ipaddr, remote_port);

newch = channel_new("x11",

nc = channel_new("accepted x11 socket",

SSH_CHANNEL_OPENING, newsock, newsock, -1,

c->local_window_max, c->local_maxpacket,

0, xstrdup(buf), 1);

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring("x11");

packet_put_int(newch);

packet_put_int(nc->self);

packet_put_int(c->local_window_max);

packet_put_int(nc->local_window_max);

packet_put_int(c->local_maxpacket);

packet_put_int(nc->local_maxpacket);

/* originator ipaddr and port */

packet_put_cstring(remote_ipaddr);

if (datafellows & SSH_BUG_X11FWD) {

Line 695

Line 1019

packet_send();

} else {

packet_start(SSH_SMSG_X11_OPEN);

packet_put_int(newch);

packet_put_int(nc->self);

if (have_hostname_in_open)

if (packet_get_protocol_flags() &

packet_put_string(buf, strlen(buf));

SSH_PROTOFLAG_HOST_IN_FWD_OPEN)

packet_put_cstring(buf);

packet_send();

}

xfree(remote_ipaddr);

}

void

static void

port_open_helper(Channel *c, char *rtype)

{

int direct;

Line 747

Line 1072

packet_put_int(c->self);

packet_put_cstring(c->path);

packet_put_int(c->host_port);

if (have_hostname_in_open)

if (packet_get_protocol_flags() &

SSH_PROTOFLAG_HOST_IN_FWD_OPEN)

packet_put_cstring(c->remote_name);

packet_send();

}

Line 757

Line 1083

* This socket is listening for connections to a forwarded TCP/IP port.

void

static void

channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)

{

Channel *nc;

struct sockaddr addr;

int newsock, newch, nextstate;

int newsock, nextstate;

socklen_t addrlen;

char *rtype;

Line 771

Line 1097

"to %.100s port %d requested.",

c->listening_port, c->path, c->host_port);

rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?

if (c->type == SSH_CHANNEL_RPORT_LISTENER) {

"forwarded-tcpip" : "direct-tcpip";

nextstate = SSH_CHANNEL_OPENING;

nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :

rtype = "forwarded-tcpip";

SSH_CHANNEL_OPENING;

} else {

if (c->host_port == 0) {

nextstate = SSH_CHANNEL_DYNAMIC;

rtype = "dynamic-tcpip";

} else {

nextstate = SSH_CHANNEL_OPENING;

rtype = "direct-tcpip";

}

addrlen = sizeof(addr);

newsock = accept(c->sock, &addr, &addrlen);

Line 782

Line 1116

error("accept: %.100s", strerror(errno));

return;

}

newch = channel_new(rtype,

set_nodelay(newsock);

nc = channel_new(rtype,

nextstate, newsock, newsock, -1,

c->local_window_max, c->local_maxpacket,

0, xstrdup(rtype), 1);

nc = channel_lookup(newch);

if (nc == NULL) {

error("xxx: no new channel:");

return;

}

nc->listening_port = c->listening_port;

nc->host_port = c->host_port;

strlcpy(nc->path, c->path, sizeof(nc->path));

if (nextstate != SSH_CHANNEL_DYNAMIC)

if (nextstate == SSH_CHANNEL_DYNAMIC) {

* do not call the channel_post handler until

* this flag has been reset by a pre-handler.

* otherwise the FD_ISSET calls might overflow

nc->delayed = 1;

} else {

port_open_helper(nc, rtype);

}

Line 805

Line 1142

* This is the authentication agent socket listening for connections from

* clients.

void

static void

channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)

{

Channel *nc;

char *name;

int newsock;

struct sockaddr addr;

int newsock, newch;

socklen_t addrlen;

if (FD_ISSET(c->sock, readset)) {

Line 819

Line 1158

error("accept from auth socket: %.100s", strerror(errno));

return;

}

newch = channel_new("accepted auth socket",

name = xstrdup("accepted auth socket");

nc = channel_new("accepted auth socket",

SSH_CHANNEL_OPENING, newsock, newsock, -1,

c->local_window_max, c->local_maxpacket,

0, xstrdup("accepted auth socket"), 1);

0, name, 1);

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring("auth-agent@openssh.com");

packet_put_int(newch);

packet_put_int(nc->self);

packet_put_int(c->local_window_max);

packet_put_int(c->local_maxpacket);

} else {

packet_start(SSH_SMSG_AGENT_OPEN);

packet_put_int(newch);

packet_put_int(nc->self);

}

packet_send();

}

void

static void

channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)

{

int err = 0;

socklen_t sz = sizeof(err);

if (FD_ISSET(c->sock, writeset)) {

int err = 0;

if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {

int sz = sizeof(err);

err = errno;

c->type = SSH_CHANNEL_OPEN;

error("getsockopt SO_ERROR failed");

if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {

}

debug("getsockopt SO_ERROR failed");

if (err == 0) {

debug("channel %d: connected", c->self);

c->type = SSH_CHANNEL_OPEN;

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(c->remote_id);

packet_put_int(c->self);

packet_put_int(c->local_window);

packet_put_int(c->local_maxpacket);

} else {

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(c->remote_id);

packet_put_int(c->self);

}

} else {

if (err == 0) {

debug("channel %d: not connected: %s",

debug("channel %d: connected)", c->self);

c->self, strerror(err));

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);

packet_put_int(c->remote_id);

packet_put_int(SSH2_OPEN_CONNECT_FAILED);

if (!(datafellows & SSH_BUG_OPENFAILURE)) {

packet_put_cstring(strerror(err));

packet_put_cstring("");

}

} else {

debug("channel %d: not connected: %s",

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

c->self, strerror(err));

packet_put_int(c->remote_id);

chan_read_failed(c);

chan_write_failed(c);

}

chan_mark_dead(c);

}

packet_send();

}

int

static int

channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)

{

char buf[16*1024];

Line 875

Line 1239

c->self, c->rfd, len);

if (c->type != SSH_CHANNEL_OPEN) {

debug("channel %d: not open", c->self);

channel_free(c->self);

chan_mark_dead(c);

return -1;

} else if (compat13) {

buffer_consume(&c->output, buffer_len(&c->output));

buffer_clear(&c->output);

c->type = SSH_CHANNEL_INPUT_DRAINING;

debug("channel %d: status set to input draining.", c->self);

debug("channel %d: input draining.", c->self);

} else {

chan_read_failed(c);

}

return -1;

}

if(c->input_filter != NULL) {

if (c->input_filter != NULL) {

if (c->input_filter(c, buf, len) == -1) {

debug("channel %d: filter stops", c->self);

chan_read_failed(c);

Line 897

Line 1261

}

return 1;

}

int

static int

channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)

{

struct termios tio;

u_char *data;

u_int dlen;

int len;

/* Send buffered output data to the socket. */

if (c->wfd != -1 &&

FD_ISSET(c->wfd, writeset) &&

buffer_len(&c->output) > 0) {

len = write(c->wfd, buffer_ptr(&c->output),

data = buffer_ptr(&c->output);

buffer_len(&c->output));

dlen = buffer_len(&c->output);

len = write(c->wfd, data, dlen);

if (len < 0 && (errno == EINTR || errno == EAGAIN))

return 1;

if (len <= 0) {

if (c->type != SSH_CHANNEL_OPEN) {

debug("channel %d: not open", c->self);

channel_free(c->self);

chan_mark_dead(c);

return -1;

} else if (compat13) {

buffer_consume(&c->output, buffer_len(&c->output));

buffer_clear(&c->output);

debug("channel %d: status set to input draining.", c->self);

debug("channel %d: input draining.", c->self);

c->type = SSH_CHANNEL_INPUT_DRAINING;

} else {

chan_write_failed(c);

}

return -1;

}

if (compat20 && c->isatty) {

if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {

if (tcgetattr(c->wfd, &tio) == 0 &&

!(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {

Line 945

Line 1312

}

return 1;

}

int

static int

channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)

{

char buf[16*1024];

Line 965

Line 1332

if (len <= 0) {

debug2("channel %d: closing write-efd %d",

c->self, c->efd);

close(c->efd);

channel_close_fd(&c->efd);

c->efd = -1;

} else {

buffer_consume(&c->extended, len);

c->local_consumed += len;

Line 975

Line 1341

FD_ISSET(c->efd, readset)) {

len = read(c->efd, buf, sizeof(buf));

debug2("channel %d: read %d from efd %d",

c->self, len, c->efd);

if (len < 0 && (errno == EINTR || errno == EAGAIN))

return 1;

if (len <= 0) {

debug2("channel %d: closing read-efd %d",

c->self, c->efd);

close(c->efd);

channel_close_fd(&c->efd);

c->efd = -1;

} else {

buffer_append(&c->extended, buf, len);

}

Line 990

Line 1355

}

return 1;

}

int

static int

channel_check_window(Channel *c)

{

if (c->type == SSH_CHANNEL_OPEN &&

Line 1010

Line 1375

return 1;

}

void

static void

channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)

channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)

{

if (c->delayed)

return;

channel_handle_rfd(c, readset, writeset);

channel_handle_wfd(c, readset, writeset);

}

if (!compat20)

return;

void

channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)

{

channel_handle_rfd(c, readset, writeset);

channel_handle_wfd(c, readset, writeset);

channel_handle_efd(c, readset, writeset);

channel_check_window(c);

}

void

static void

channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)

{

int len;

Line 1036

Line 1397

len = write(c->sock, buffer_ptr(&c->output),

buffer_len(&c->output));

if (len <= 0)

buffer_consume(&c->output, buffer_len(&c->output));

buffer_clear(&c->output);

else

buffer_consume(&c->output, len);

}

void

static void

channel_handler_init_20(void)

{

channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;

channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;

channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;

channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;

channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;

Line 1054

Line 1415

channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;

channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;

channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;

channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;

channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;

channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;

channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;

}

void

static void

channel_handler_init_13(void)

{

channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;

Line 1076

Line 1437

channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;

channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;

channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;

channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;

channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;

channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;

channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;

}

void

static void

channel_handler_init_15(void)

{

channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;

channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;

channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;

channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;

channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;

Line 1099

Line 1460

channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;

channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;

channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;

channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;

channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;

channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;

}

void

static void

channel_handler_init(void)

{

int i;

for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {

for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {

channel_pre[i] = NULL;

channel_post[i] = NULL;

}

Line 1120

Line 1481

channel_handler_init_15();

}

void

/* gc dead channels */

static void

channel_garbage_collect(Channel *c)

{

if (c == NULL)

return;

if (c->detach_user != NULL) {

if (!chan_is_dead(c, 0))

return;

debug("channel %d: gc: notify user", c->self);

c->detach_user(c->self, NULL);

/* if we still have a callback */

if (c->detach_user != NULL)

return;

debug("channel %d: gc: user detached", c->self);

}

if (!chan_is_dead(c, 1))

return;

debug("channel %d: garbage collecting", c->self);

channel_free(c);

}

static void

channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)

{

static int did_init = 0;

Line 1132

Line 1515

did_init = 1;

}

for (i = 0; i < channels_alloc; i++) {

c = &channels[i];

c = channels[i];

if (c->type == SSH_CHANNEL_FREE)

if (c == NULL)

continue;

if (ftab[c->type] == NULL)

if (ftab[c->type] != NULL)

continue;

(*ftab[c->type])(c, readset, writeset);

channel_garbage_collect(c);

if (chan_is_dead(c)) {

* we have to remove the fd's from the select mask

* before the channels are free'd and the fd's are

* closed

if (c->wfd != -1)

FD_CLR(c->wfd, writeset);

if (c->rfd != -1)

FD_CLR(c->rfd, readset);

if (c->efd != -1) {

if (c->extended_usage == CHAN_EXTENDED_READ)

FD_CLR(c->efd, readset);

if (c->extended_usage == CHAN_EXTENDED_WRITE)

FD_CLR(c->efd, writeset);

}

channel_free(c->self);

}

* Allocate/update select bitmasks and add any bits relevant to channels in

* select bitmasks.

void

channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,

int rekeying)

int *nallocp, int rekeying)

{

int n;

u_int sz;

Line 1169

Line 1538

n = MAX(*maxfdp, channel_max_fd);

sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);

if (*readsetp == NULL || n > *maxfdp) {

/* perhaps check sz < nalloc/2 and shrink? */

if (*readsetp)

if (*readsetp == NULL || sz > *nallocp) {

xfree(*readsetp);

*readsetp = xrealloc(*readsetp, sz);

if (*writesetp)

*writesetp = xrealloc(*writesetp, sz);

xfree(*writesetp);

*nallocp = sz;

*readsetp = xmalloc(sz);

*writesetp = xmalloc(sz);

*maxfdp = n;

}

*maxfdp = n;

memset(*readsetp, 0, sz);

memset(*writesetp, 0, sz);

Line 1185

Line 1552

channel_handler(channel_pre, *readsetp, *writesetp);

}

* After select, perform any appropriate operations for channels which have

* events pending.

void

channel_after_select(fd_set * readset, fd_set * writeset)

{

channel_handler(channel_post, readset, writeset);

}

/* If there is data to send to the connection, enqueue some of it now. */

void

channel_output_poll()

channel_output_poll(void)

{

int len, i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = &channels[i];

c = channels[i];

if (c == NULL)

continue;

/* We are only interested in channels that can have buffered incoming data. */

* We are only interested in channels that can have buffered

* incoming data.

if (compat13) {

if (c->type != SSH_CHANNEL_OPEN &&

c->type != SSH_CHANNEL_INPUT_DRAINING)

Line 1214

Line 1591

if (compat20 &&

(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {

/* XXX is this true? */

debug2("channel %d: no data after CLOSE", c->self);

debug3("channel %d: will not send data after close", c->self);

continue;

}

Line 1222

Line 1599

if ((c->istate == CHAN_INPUT_OPEN ||

c->istate == CHAN_INPUT_WAIT_DRAIN) &&

(len = buffer_len(&c->input)) > 0) {

/* Send some data for the other side over the secure connection. */

* Send some data for the other side over the secure

* connection.

if (compat20) {

if (len > c->remote_window)

len = c->remote_window;

Line 1280

Line 1660

}

* This is called when a packet of type CHANNEL_DATA has just been received.

* The message type has already been consumed, but channel number and data is

* still there.

/* -- protocol input */

void

channel_input_data(int type, int plen, void *ctxt)

channel_input_data(int type, u_int32_t seq, void *ctxt)

{

int id;

char *data;

Line 1311

Line 1688

/* Get the data. */

data = packet_get_string(&data_len);

packet_done();

if (compat20){

if (compat20) {

if (data_len > c->local_maxpacket) {

log("channel %d: rcvd big packet %d, maxpack %d",

c->self, data_len, c->local_maxpacket);

Line 1325

Line 1701

return;

}

c->local_window -= data_len;

}else{

packet_integrity_check(plen, 4 + 4 + data_len, type);

}

packet_check_eom();

buffer_append(&c->output, data, data_len);

xfree(data);

}

void

channel_input_extended_data(int type, int plen, void *ctxt)

channel_input_extended_data(int type, u_int32_t seq, void *ctxt)

{

int id;

int tcode;

Line 1358

Line 1734

return;

}

data = packet_get_string(&data_len);

packet_done();

packet_check_eom();

if (data_len > c->local_window) {

log("channel %d: rcvd too much extended_data %d, win %d",

c->self, data_len, c->local_window);

Line 1371

Line 1747

xfree(data);

}

* Returns true if no channel has too much buffered data, and false if one or

* more channel is overfull.

int

channel_not_very_much_buffered_data()

{

u_int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

c = &channels[i];

if (c->type == SSH_CHANNEL_OPEN) {

if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {

debug("channel %d: big input buffer %d",

c->self, buffer_len(&c->input));

return 0;

}

if (buffer_len(&c->output) > packet_get_maxsize()) {

debug("channel %d: big output buffer %d",

c->self, buffer_len(&c->output));

return 0;

}

return 1;

}

void

channel_input_ieof(int type, int plen, void *ctxt)

channel_input_ieof(int type, u_int32_t seq, void *ctxt)

{

int id;

Channel *c;

packet_integrity_check(plen, 4, type);

id = packet_get_int();

packet_check_eom();

c = channel_lookup(id);

if (c == NULL)

packet_disconnect("Received ieof for nonexistent channel %d.", id);

chan_rcvd_ieof(c);

/* XXX force input close */

if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {

debug("channel %d: FORCE input drain", c->self);

c->istate = CHAN_INPUT_WAIT_DRAIN;

if (buffer_len(&c->input) == 0)

chan_ibuf_empty(c);

}

void

channel_input_close(int type, int plen, void *ctxt)

channel_input_close(int type, u_int32_t seq, void *ctxt)

{

int id;

Channel *c;

packet_integrity_check(plen, 4, type);

id = packet_get_int();

packet_check_eom();

c = channel_lookup(id);

if (c == NULL)

packet_disconnect("Received close for nonexistent channel %d.", id);

Line 1449

Line 1802

* Not a closed channel - mark it as draining, which will

* cause it to be freed later.

buffer_consume(&c->input, buffer_len(&c->input));

buffer_clear(&c->input);

c->type = SSH_CHANNEL_OUTPUT_DRAINING;

}

/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */

void

channel_input_oclose(int type, int plen, void *ctxt)

channel_input_oclose(int type, u_int32_t seq, void *ctxt)

{

int id = packet_get_int();

Channel *c = channel_lookup(id);

packet_integrity_check(plen, 4, type);

packet_check_eom();

if (c == NULL)

packet_disconnect("Received oclose for nonexistent channel %d.", id);

chan_rcvd_oclose(c);

}

void

channel_input_close_confirmation(int type, int plen, void *ctxt)

channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)

{

int id = packet_get_int();

Channel *c = channel_lookup(id);

packet_done();

packet_check_eom();

if (c == NULL)

packet_disconnect("Received close confirmation for "

"out-of-range channel %d.", id);

if (c->type != SSH_CHANNEL_CLOSED)

packet_disconnect("Received close confirmation for "

"non-closed channel %d (type %d).", id, c->type);

channel_free(c->self);

channel_free(c);

}

void

channel_input_open_confirmation(int type, int plen, void *ctxt)

channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)

{

int id, remote_id;

Channel *c;

if (!compat20)

packet_integrity_check(plen, 4 + 4, type);

id = packet_get_int();

c = channel_lookup(id);

Line 1505

Line 1856

if (compat20) {

c->remote_window = packet_get_int();

c->remote_maxpacket = packet_get_int();

packet_done();

if (c->confirm) {

if (c->cb_fn != NULL && c->cb_event == type) {

debug2("callback start");

c->cb_fn(c->self, c->cb_arg);

c->confirm(c->self, NULL);

debug2("callback done");

}

debug("channel %d: open confirm rwindow %d rmax %d", c->self,

c->remote_window, c->remote_maxpacket);

}

packet_check_eom();

}

static char *

reason2txt(int reason)

{

switch (reason) {

case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:

return "administratively prohibited";

case SSH2_OPEN_CONNECT_FAILED:

return "connect failed";

case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:

return "unknown channel type";

case SSH2_OPEN_RESOURCE_SHORTAGE:

return "resource shortage";

}

return "unknown reason";

}

void

channel_input_open_failure(int type, int plen, void *ctxt)

channel_input_open_failure(int type, u_int32_t seq, void *ctxt)

{

int id, reason;

char *msg = NULL, *lang = NULL;

Channel *c;

if (!compat20)

packet_integrity_check(plen, 4, type);

id = packet_get_int();

c = channel_lookup(id);

Line 1534

Line 1898

"non-opening channel %d.", id);

if (compat20) {

reason = packet_get_int();

if (packet_remaining() > 0) {

if (!(datafellows & SSH_BUG_OPENFAILURE)) {

msg = packet_get_string(NULL);

lang = packet_get_string(NULL);

}

packet_done();

log("channel %d: open failed: %s%s%s", id,

log("channel_open_failure: %d: reason %d %s", id,

reason2txt(reason), msg ? ": ": "", msg ? msg : "");

reason, msg ? msg : "<no additional info>");

if (msg != NULL)

xfree(msg);

if (lang != NULL)

xfree(lang);

}

packet_check_eom();

/* Free the channel. This will also close the socket. */

channel_free(id);

channel_free(c);

}

void

channel_input_channel_request(int type, int plen, void *ctxt)

channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)

{

int id;

Channel *c;

id = packet_get_int();

c = channel_lookup(id);

if (c == NULL ||

(c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))

packet_disconnect("Received request for "

"non-open channel %d.", id);

if (c->cb_fn != NULL && c->cb_event == type) {

debug2("callback start");

c->cb_fn(c->self, c->cb_arg);

debug2("callback done");

} else {

char *service = packet_get_string(NULL);

debug("channel %d: rcvd request for %s", c->self, service);

debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);

xfree(service);

}

void

channel_input_window_adjust(int type, int plen, void *ctxt)

{

Channel *c;

int id, adjust;

if (!compat20)

Line 1594

Line 1933

return;

}

adjust = packet_get_int();

packet_done();

packet_check_eom();

debug2("channel %d: rcvd adjust %d", id, adjust);

c->remote_window += adjust;

}

* Stops listening for channels, and removes any unix domain sockets that we

* might have.

void

channel_stop_listening()

channel_input_port_open(int type, u_int32_t seq, void *ctxt)

{

int i;

Channel *c = NULL;

for (i = 0; i < channels_alloc; i++) {

u_short host_port;

switch (channels[i].type) {

char *host, *originator_string;

case SSH_CHANNEL_AUTH_SOCKET:

int remote_id, sock = -1;

close(channels[i].sock);

unlink(channels[i].path);

channel_free(i);

break;

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_X11_LISTENER:

close(channels[i].sock);

channel_free(i);

break;

default:

break;

}

remote_id = packet_get_int();

* Closes the sockets/fds of all channels. This is used to close extra file

host = packet_get_string(NULL);

* descriptors after a fork.

host_port = packet_get_int();

void

if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {

channel_close_all()

originator_string = packet_get_string(NULL);

{

} else {

int i;

originator_string = xstrdup("unknown (remote did not supply name)");

for (i = 0; i < channels_alloc; i++)

}

if (channels[i].type != SSH_CHANNEL_FREE)

packet_check_eom();

channel_close_fds(&channels[i]);

sock = channel_connect_to(host, host_port);

if (sock != -1) {

c = channel_new("connected socket",

SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,

originator_string, 1);

c->remote_id = remote_id;

}

if (c == NULL) {

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

packet_put_int(remote_id);

packet_send();

}

xfree(host);

}

/* Returns true if any channel is still open. */

int

/* -- tcp forwarding */

channel_still_open()

{

u_int i;

for (i = 0; i < channels_alloc; i++)

switch (channels[i].type) {

case SSH_CHANNEL_FREE:

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_CONNECTING: /* XXX ??? */

continue;

case SSH_CHANNEL_LARVAL:

if (!compat20)

fatal("cannot happen: SSH_CHANNEL_LARVAL");

continue;

case SSH_CHANNEL_OPENING:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

return 1;

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

if (!compat13)

fatal("cannot happen: OUT_DRAIN");

return 1;

default:

fatal("channel_still_open: bad channel type %d", channels[i].type);

/* NOTREACHED */

}

return 0;

}

/* Returns the id of an open channel suitable for keepaliving */

void

channel_set_af(int af)

int

channel_find_open()

{

u_int i;

IPv4or6 = af;

for (i = 0; i < channels_alloc; i++)

switch (channels[i].type) {

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_FREE:

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_OPENING:

continue;

case SSH_CHANNEL_LARVAL:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_CONNECTING: /* XXX ??? */

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

return i;

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

if (!compat13)

fatal("cannot happen: OUT_DRAIN");

return i;

default:

fatal("channel_find_open: bad channel type %d", channels[i].type);

/* NOTREACHED */

}

return -1;

}

static int

channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,

* Returns a message describing the currently open forwarded connections,

const char *host_to_connect, u_short port_to_connect, int gateway_ports)

* suitable for sending to the client. The message contains crlf pairs for

* newlines.

char *

channel_open_message()

{

Buffer buffer;

Channel *c;

int i;

int success, sock, on = 1;

char buf[512], *cp;

buffer_init(&buffer);

snprintf(buf, sizeof buf, "The following connections are open:\r\n");

buffer_append(&buffer, buf, strlen(buf));

for (i = 0; i < channels_alloc; i++) {

Channel *c = &channels[i];

switch (c->type) {

case SSH_CHANNEL_FREE:

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_AUTH_SOCKET:

continue;

case SSH_CHANNEL_LARVAL:

case SSH_CHANNEL_OPENING:

case SSH_CHANNEL_CONNECTING:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",

c->self, c->remote_name,

c->type, c->remote_id,

c->istate, buffer_len(&c->input),

c->ostate, buffer_len(&c->output),

c->rfd, c->wfd);

buffer_append(&buffer, buf, strlen(buf));

continue;

default:

fatal("channel_open_message: bad channel type %d", c->type);

/* NOTREACHED */

}

buffer_append(&buffer, "\0", 1);

cp = xstrdup(buffer_ptr(&buffer));

buffer_free(&buffer);

return cp;

}

* Initiate forwarding of connections to local port "port" through the secure

* channel to host:port from remote side.

int

channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,

u_short port_to_connect, int gateway_ports)

{

return channel_request_forwarding(

NULL, listen_port,

host_to_connect, port_to_connect,

gateway_ports, /*remote_fwd*/ 0);

}

* If 'remote_fwd' is true we have a '-R style' listener for protocol 2

* (SSH_CHANNEL_RPORT_LISTENER).

int

channel_request_forwarding(

const char *listen_address, u_short listen_port,

const char *host_to_connect, u_short port_to_connect,

int gateway_ports, int remote_fwd)

{

int success, ch, sock, on = 1, ctype;

struct addrinfo hints, *ai, *aitop;

char ntop[NI_MAXHOST], strport[NI_MAXSERV];

const char *host;

char ntop[NI_MAXHOST], strport[NI_MAXSERV];

struct linger linger;

success = 0;

host = (type == SSH_CHANNEL_RPORT_LISTENER) ?

listen_addr : host_to_connect;

if (remote_fwd) {

if (host == NULL) {

host = listen_address;

error("No forward host name.");

ctype = SSH_CHANNEL_RPORT_LISTENER;

return success;

} else {

host = host_to_connect;

ctype =SSH_CHANNEL_PORT_LISTENER;

}

if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {

if (strlen(host) > sizeof(channels[0].path) - 1) {

error("Forward host name too long.");

return success;

}

/* XXX listen_address is currently ignored */

* getaddrinfo returns a loopback address if the hostname is

* set to NULL and hints.ai_flags is not AI_PASSIVE

Line 1829

Line 2021

continue;

if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),

strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {

error("channel_request_forwarding: getnameinfo failed");

error("channel_setup_fwd_listener: getnameinfo failed");

continue;

}

/* Create a port to listen for the host. */

Line 1843

Line 2035

* Set socket options. We would like the socket to disappear

* as soon as it has been closed for whatever reason.

setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));

setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

linger.l_onoff = 1;

linger.l_linger = 5;

setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));

setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));

debug("Local forwarding listening on %s port %s.", ntop, strport);

/* Bind the socket to the address. */

Line 1863

Line 2055

continue;

}

/* Allocate a channel number for the socket. */

ch = channel_new("port listener", ctype, sock, sock, -1,

c = channel_new("port listener", type, sock, sock, -1,

CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,

0, xstrdup("port listener"), 1);

strlcpy(channels[ch].path, host, sizeof(channels[ch].path));

strlcpy(c->path, host, sizeof(c->path));

channels[ch].host_port = port_to_connect;

c->host_port = port_to_connect;

channels[ch].listening_port = listen_port;

c->listening_port = listen_port;

success = 1;

}

if (success == 0)

error("channel_request_forwarding: cannot listen to port: %d",

error("channel_setup_fwd_listener: cannot listen to port: %d",

listen_port);

freeaddrinfo(aitop);

return success;

}

/* protocol local port fwd, used by ssh (and sshd in v1) */

int

channel_setup_local_fwd_listener(u_short listen_port,

const char *host_to_connect, u_short port_to_connect, int gateway_ports)

{

return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,

NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);

}

/* protocol v2 remote port fwd, used by sshd */

int

channel_setup_remote_fwd_listener(const char *listen_address,

u_short listen_port, int gateway_ports)

{

return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,

listen_address, listen_port, NULL, 0, gateway_ports);

}

* Initiate forwarding of connections to port "port" on remote host through

* the secure channel to host:port from local side.

Line 1887

Line 2097

channel_request_remote_forwarding(u_short listen_port,

const char *host_to_connect, u_short port_to_connect)

{

int payload_len, type, success = 0;

int type, success = 0;

/* Record locally that connection to this host/port is permitted. */

if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)

Line 1914

Line 2124

packet_write_wait();

/* Wait for response from the remote side. */

type = packet_read(&payload_len);

type = packet_read();

switch (type) {

case SSH_SMSG_SUCCESS:

success = 1;

Line 1961

Line 2171

packet_disconnect("Requested forwarding of port %d but user is not root.",

port);

/* Initiate forwarding */

channel_request_local_forwarding(port, hostname, host_port, gateway_ports);

channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);

/* Free the argument string. */

xfree(hostname);

Line 1973

Line 2183

* anyway, and the server has no way to know but to trust the client anyway.

void

channel_permit_all_opens()

channel_permit_all_opens(void)

{

if (num_permitted_opens == 0)

all_opens_permitted = 1;

Line 2006

Line 2216

/* return socket to remote host, port */

int

static int

connect_to(const char *host, u_short port)

{

struct addrinfo hints, *ai, *aitop;

Line 2054

Line 2264

return -1;

}

/* success */

set_nodelay(sock);

return sock;

}

int

channel_connect_by_listen_adress(u_short listen_port)

channel_connect_by_listen_address(u_short listen_port)

{

int i;

Line 2094

Line 2305

return connect_to(host, port);

}

/* -- X11 forwarding */

* This is called after receiving PORT_OPEN message. This attempts to

* connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION

* or CHANNEL_OPEN_FAILURE.

void

channel_input_port_open(int type, int plen, void *ctxt)

{

u_short host_port;

char *host, *originator_string;

int remote_channel, sock = -1, newch;

remote_channel = packet_get_int();

host = packet_get_string(NULL);

host_port = packet_get_int();

if (have_hostname_in_open) {

originator_string = packet_get_string(NULL);

} else {

originator_string = xstrdup("unknown (remote did not supply name)");

}

packet_done();

sock = channel_connect_to(host, host_port);

if (sock != -1) {

newch = channel_allocate(SSH_CHANNEL_CONNECTING,

sock, originator_string);

channels[newch].remote_id = remote_channel;

/*XXX delay answer? */

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(remote_channel);

packet_put_int(newch);

packet_send();

} else {

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

packet_put_int(remote_channel);

packet_send();

}

xfree(host);

}

* Creates an internet domain socket for listening for X11 connections.

* Returns a suitable value for the DISPLAY variable, or NULL if an error

* Returns a suitable display number for the DISPLAY variable, or -1 if

* occurs.

* an error occurs.

int

#define NUM_SOCKS 10

x11_create_display_inet(int x11_display_offset, int x11_use_localhost,

int single_connection)

char *

x11_create_display_inet(int screen_number, int x11_display_offset)

{

Channel *nc = NULL;

int display_number, sock;

u_short port;

struct addrinfo hints, *ai, *aitop;

char strport[NI_MAXSERV];

int gaierr, n, num_socks = 0, socks[NUM_SOCKS];

char display[512];

char hostname[MAXHOSTNAMELEN];

for (display_number = x11_display_offset;

display_number < MAX_DISPLAYS;

display_number++) {

port = 6000 + display_number;

memset(&hints, 0, sizeof(hints));

hints.ai_family = IPv4or6;

hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */

hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;

hints.ai_socktype = SOCK_STREAM;

snprintf(strport, sizeof strport, "%d", port);

if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {

error("getaddrinfo: %.100s", gai_strerror(gaierr));

return NULL;

return -1;

}

for (ai = aitop; ai; ai = ai->ai_next) {

if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)

Line 2174

Line 2342

sock = socket(ai->ai_family, SOCK_STREAM, 0);

if (sock < 0) {

error("socket: %.100s", strerror(errno));

return NULL;

return -1;

}

if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {

debug("bind port %d: %.100s", port, strerror(errno));

shutdown(sock, SHUT_RDWR);

close(sock);

for (n = 0; n < num_socks; n++) {

shutdown(socks[n], SHUT_RDWR);

close(socks[n]);

}

num_socks = 0;

Line 2197

Line 2363

}

if (display_number >= MAX_DISPLAYS) {

error("Failed to allocate internet-domain X11 display socket.");

return NULL;

return -1;

}

/* Start listening for connections on the socket. */

for (n = 0; n < num_socks; n++) {

sock = socks[n];

if (listen(sock, 5) < 0) {

error("listen: %.100s", strerror(errno));

shutdown(sock, SHUT_RDWR);

close(sock);

return NULL;

return -1;

}

/* Set up a suitable value for the DISPLAY variable. */

if (gethostname(hostname, sizeof(hostname)) < 0)

fatal("gethostname: %.100s", strerror(errno));

snprintf(display, sizeof display, "%.400s:%d.%d", hostname,

display_number, screen_number);

/* Allocate a channel for each socket. */

for (n = 0; n < num_socks; n++) {

sock = socks[n];

(void) channel_new("x11 listener",

nc = channel_new("x11 listener",

SSH_CHANNEL_X11_LISTENER, sock, sock, -1,

CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,

0, xstrdup("X11 inet listener"), 1);

nc->single_connection = single_connection;

}

/* Return a suitable value for the DISPLAY environment variable. */

/* Return the display number for the DISPLAY environment variable. */

return xstrdup(display);

return display_number;

}

#ifndef X_UNIX_PATH

static int

#define X_UNIX_PATH "/tmp/.X11-unix/X"

#endif

static

int

connect_local_xsocket(u_int dnr)

{

static const char *const x_sockets[] = {

X_UNIX_PATH "%u",

"/var/X/.X11-unix/X" "%u",

"/usr/spool/sockets/X11/" "%u",

NULL

};

int sock;

struct sockaddr_un addr;

const char *const * path;

for (path = x_sockets; *path; ++path) {

sock = socket(AF_UNIX, SOCK_STREAM, 0);

if (sock < 0)

error("socket: %.100s", strerror(errno));

memset(&addr, 0, sizeof(addr));

addr.sun_family = AF_UNIX;

snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);

snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);

if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)

return sock;

close(sock);

}

error("connect %.100s: %.100s", addr.sun_path, strerror(errno));

return -1;

}

Line 2292

Line 2438

/* Connect to the unix domain socket. */

if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {

error("Could not parse display number from DISPLAY: %.100s",

display);

return -1;

}

/* Create a socket. */

Line 2307

Line 2453

* Connect to an inet socket. The DISPLAY value is supposedly

* hostname:d[.s], where hostname may also be numeric IP address.

strncpy(buf, display, sizeof(buf));

strlcpy(buf, display, sizeof(buf));

buf[sizeof(buf) - 1] = 0;

cp = strchr(buf, ':');

if (!cp) {

error("Could not find ':' in DISPLAY: %.100s", display);

Line 2318

Line 2463

/* buf now contains the host name. But first we parse the display number. */

if (sscanf(cp + 1, "%d", &display_number) != 1) {

error("Could not parse display number from DISPLAY: %.100s",

display);

return -1;

}

Line 2354

Line 2499

strerror(errno));

return -1;

}

set_nodelay(sock);

return sock;

}

Line 2364

Line 2510

void

x11_input_open(int type, int plen, void *ctxt)

x11_input_open(int type, u_int32_t seq, void *ctxt)

{

int remote_channel, sock = 0, newch;

Channel *c = NULL;

int remote_id, sock = 0;

char *remote_host;

u_int remote_len;

/* Get remote channel number. */

debug("Received X11 open request.");

remote_channel = packet_get_int();

/* Get remote originator name. */

remote_id = packet_get_int();

if (have_hostname_in_open) {

remote_host = packet_get_string(&remote_len);

if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {

remote_len += 4;

remote_host = packet_get_string(NULL);

} else {

remote_host = xstrdup("unknown (remote did not supply name)");

remote_len = 0;

}

packet_check_eom();

debug("Received X11 open request.");

packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);

/* Obtain a connection to the real X display. */

sock = x11_connect_display();

if (sock == -1) {

if (sock != -1) {

/* Allocate a channel for this connection. */

c = channel_new("connected x11 socket",

SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,

remote_host, 1);

c->remote_id = remote_id;

c->force_drain = 1;

}

if (c == NULL) {

/* Send refusal to the remote host. */

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

packet_put_int(remote_channel);

packet_put_int(remote_id);

packet_send();

} else {

/* Allocate a channel for this connection. */

newch = channel_allocate(

(x11_saved_proto == NULL) ?

SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,

sock, remote_host);

channels[newch].remote_id = remote_channel;

/* Send a confirmation to the remote host. */

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(remote_channel);

packet_put_int(remote_id);

packet_put_int(newch);

packet_put_int(c->self);

packet_send();

}

packet_send();

}

/* dummy protocol handler that denies SSH-1 requests (agent/x11) */

void

deny_input_open(int type, int plen, void *ctxt)

deny_input_open(int type, u_int32_t seq, void *ctxt)

{

int rchan = packet_get_int();

switch(type){

switch (type) {

case SSH_SMSG_AGENT_OPEN:

error("Warning: ssh server tried agent forwarding.");

break;

Line 2421

Line 2563

error("Warning: ssh server tried X11 forwarding.");

break;

default:

error("deny_input_open: type %d plen %d", type, plen);

error("deny_input_open: type %d", type);

break;

}

error("Warning: this is probably a break in attempt by a malicious server.");

Line 2433

Line 2575

* Requests forwarding of X11 connections, generates fake authentication

* data, and enables authentication spoofing.

* This should be called in the client only.

void

x11_request_forwarding_with_spoofing(int client_session_id,

const char *proto, const char *data)

Line 2499

Line 2641

xfree(new_data);

}

/* -- agent forwarding */

/* Sends a message to the server to request authentication fd forwarding. */

void

auth_request_forwarding()

auth_request_forwarding(void)

{

packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);

packet_send();

Line 2516

Line 2661

char *

auth_get_socket_name()

auth_get_socket_name(void)

{

return channel_forwarded_auth_socket_name;

return auth_sock_name;

}

/* removes the agent forwarding socket */

void

cleanup_socket(void)

auth_sock_cleanup_proc(void *_pw)

{

unlink(channel_forwarded_auth_socket_name);

struct passwd *pw = _pw;

rmdir(channel_forwarded_auth_socket_dir);

if (auth_sock_name) {

temporarily_use_uid(pw);

unlink(auth_sock_name);

rmdir(auth_sock_dir);

auth_sock_name = NULL;

restore_uid();

}

Line 2538

Line 2690

int

auth_input_request_forwarding(struct passwd * pw)

{

int sock, newch;

Channel *nc;

int sock;

struct sockaddr_un sunaddr;

if (auth_get_socket_name() != NULL)

if (auth_get_socket_name() != NULL) {

fatal("Protocol error: authentication forwarding requested twice.");

error("authentication forwarding requested twice.");

return 0;

}

/* Temporarily drop privileged uid for mkdir/bind. */

temporarily_use_uid(pw);

/* Allocate a buffer for the socket name, and format the name. */

channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);

auth_sock_name = xmalloc(MAXPATHLEN);

channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);

auth_sock_dir = xmalloc(MAXPATHLEN);

strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);

strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);

/* Create private directory for socket */

if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {

if (mkdtemp(auth_sock_dir) == NULL) {

packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",

packet_send_debug("Agent forwarding disabled: "

strerror(errno));

"mkdtemp() failed: %.100s", strerror(errno));

restore_uid();

xfree(channel_forwarded_auth_socket_name);

xfree(auth_sock_name);

xfree(channel_forwarded_auth_socket_dir);

xfree(auth_sock_dir);

channel_forwarded_auth_socket_name = NULL;

auth_sock_name = NULL;

channel_forwarded_auth_socket_dir = NULL;

auth_sock_dir = NULL;

return 0;

}

snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",

snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",

channel_forwarded_auth_socket_dir, (int) getpid());

auth_sock_dir, (int) getpid());

if (atexit(cleanup_socket) < 0) {

/* delete agent socket on fatal() */

int saved = errno;

fatal_add_cleanup(auth_sock_cleanup_proc, pw);

cleanup_socket();

packet_disconnect("socket: %.100s", strerror(saved));

}

/* Create the socket. */

sock = socket(AF_UNIX, SOCK_STREAM, 0);

if (sock < 0)

Line 2579

Line 2732

/* Bind it to the name. */

memset(&sunaddr, 0, sizeof(sunaddr));

sunaddr.sun_family = AF_UNIX;

strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,

strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));

sizeof(sunaddr.sun_path));

if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)

packet_disconnect("bind: %.100s", strerror(errno));

Line 2593

Line 2745

packet_disconnect("listen: %.100s", strerror(errno));

/* Allocate a channel for the authentication agent socket. */

newch = channel_new("auth socket",

nc = channel_new("auth socket",

SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,

CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,

0, xstrdup("auth socket"), 1);

strlcpy(nc->path, auth_sock_name, sizeof(nc->path));

strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,

sizeof(channels[newch].path));

return 1;

}

/* This is called to process an SSH_SMSG_AGENT_OPEN message. */

void

auth_input_open_request(int type, int plen, void *ctxt)

auth_input_open_request(int type, u_int32_t seq, void *ctxt)

{

int remch, sock, newch;

Channel *c = NULL;

char *dummyname;

int remote_id, sock;

char *name;

packet_integrity_check(plen, 4, type);

/* Read the remote channel number from the message. */

remch = packet_get_int();

remote_id = packet_get_int();

packet_check_eom();

* Get a connection to the local authentication agent (this may again

Line 2628

Line 2778

* because authentication forwarding is only enabled if we have an

* agent.

if (sock < 0) {

if (sock >= 0) {

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

name = xstrdup("authentication agent connection");

packet_put_int(remch);

c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,

packet_send();

-1, 0, 0, 0, name, 1);

return;

c->remote_id = remote_id;

c->force_drain = 1;

}

debug("Forwarding authentication connection.");

* Dummy host name. This will be freed when the channel is freed; it

* will still be valid in the packet_put_string below since the

* channel cannot yet be freed at that point.

dummyname = xstrdup("authentication agent connection");

newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);

channels[newch].remote_id = remch;

/* Send a confirmation to the remote host. */

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(remch);

packet_put_int(newch);

packet_send();

}

void

channel_start_open(int id)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_open: %d: bad id", id);

packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);

return;

packet_put_int(remote_id);

} else {

/* Send a confirmation to the remote host. */

debug("Forwarding authentication connection.");

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(remote_id);

packet_put_int(c->self);

}

debug("send channel open %d", id);

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring(c->ctype);

packet_put_int(c->self);

packet_put_int(c->local_window);

packet_put_int(c->local_maxpacket);

}

void

channel_open(int id)

{

/* XXX REMOVE ME */

channel_start_open(id);

packet_send();

}

void

channel_request(int id, char *service, int wantconfirm)

{

channel_request_start(id, service, wantconfirm);

packet_send();

debug("channel request %d: %s", id, service) ;

}

void

channel_request_start(int id, char *service, int wantconfirm)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_request: %d: bad id", id);

return;

}

packet_start(SSH2_MSG_CHANNEL_REQUEST);

packet_put_int(c->remote_id);

packet_put_cstring(service);

packet_put_char(wantconfirm);

}

void

channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_callback: %d: bad id", id);

return;

}

c->cb_event = mtype;

c->cb_fn = fn;

c->cb_arg = arg;

}

void

channel_register_cleanup(int id, channel_callback_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_cleanup: %d: bad id", id);

return;

}

c->dettach_user = fn;

}

void

channel_cancel_cleanup(int id)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_cancel_cleanup: %d: bad id", id);

return;

}

c->dettach_user = NULL;

}

void

channel_register_filter(int id, channel_filter_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_filter: %d: bad id", id);

return;

}

c->input_filter = fn;

}

void

channel_set_fds(int id, int rfd, int wfd, int efd,

int extusage, int nonblock)

{

Channel *c = channel_lookup(id);

if (c == NULL || c->type != SSH_CHANNEL_LARVAL)

fatal("channel_activate for non-larval channel %d.", id);

channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);

c->type = SSH_CHANNEL_OPEN;

/* XXX window size? */

c->local_window = c->local_window_max = c->local_maxpacket * 2;

packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);

packet_put_int(c->remote_id);

packet_put_int(c->local_window);

packet_send();

}