1 /* $OpenBSD: channels.c,v 1.433 2023/09/04 00:01:46 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * This file contains functions for generic socket connection forwarding.
7 * There is also code for initiating connection forwarding for X11 connections,
8 * arbitrary tcp/ip connections, and the authentication agent connection.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 support added by Markus Friedl.
17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Copyright (c) 1999 Dug Song. All rights reserved.
19 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 #include <sys/types.h>
46 #include <sys/ioctl.h>
48 #include <sys/socket.h>
49 #ifdef HAVE_SYS_TIME_H
50 # include <sys/time.h>
53 #include <netinet/in.h>
54 #include <arpa/inet.h>
73 #include "openbsd-compat/sys-queue.h"
87 #include "pathnames.h"
90 /* XXX remove once we're satisfied there's no lurking bugs */
91 /* #define DEBUG_CHANNEL_POLL 1 */
93 /* -- agent forwarding */
96 /* -- tcp forwarding */
97 /* special-case port number meaning allow any port */
98 #define FWD_PERMIT_ANY_PORT 0
100 /* special-case wildcard meaning allow any host */
101 #define FWD_PERMIT_ANY_HOST "*"
103 /* -- X11 forwarding */
104 /* Maximum number of fake X11 displays to try. */
105 #define MAX_DISPLAYS 1000
107 /* Per-channel callback for pre/post IO actions */
108 typedef void chan_fn(struct ssh *, Channel *c);
111 * Data structure for storing which hosts are permitted for forward requests.
112 * The local sides of any remote forwards are stored in this array to prevent
113 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
114 * network (which might be behind a firewall).
116 /* XXX: streamlocal wants a path instead of host:port */
117 /* Overload host_to_connect; we could just make this match Forward */
118 /* XXX - can we use listen_host instead of listen_path? */
120 char *host_to_connect; /* Connect to 'host'. */
121 int port_to_connect; /* Connect to 'port'. */
122 char *listen_host; /* Remote side should listen address. */
123 char *listen_path; /* Remote side should listen path. */
124 int listen_port; /* Remote side should listen port. */
125 Channel *downstream; /* Downstream mux*/
129 * Stores the forwarding permission state for a single direction (local or
132 struct permission_set {
134 * List of all local permitted host/port pairs to allow for the
137 u_int num_permitted_user;
138 struct permission *permitted_user;
141 * List of all permitted host/port pairs to allow for the admin.
143 u_int num_permitted_admin;
144 struct permission *permitted_admin;
147 * If this is true, all opens/listens are permitted. This is the
148 * case on the server on which we have to trust the client anyway,
149 * and the user could do anything after logging in.
154 /* Used to record timeouts per channel type */
155 struct ssh_channel_timeout {
160 /* Master structure for channels state */
161 struct ssh_channels {
163 * Pointer to an array containing all allocated channels. The array
164 * is dynamically extended as needed.
169 * Size of the channel array. All slots of the array must always be
170 * initialized (at least the type field); unused slots set to NULL
172 u_int channels_alloc;
175 * 'channel_pre*' are called just before IO to add any bits
176 * relevant to channels in the c->io_want bitmasks.
178 * 'channel_post*': perform any appropriate operations for
179 * channels which have c->io_ready events pending.
181 chan_fn **channel_pre;
182 chan_fn **channel_post;
184 /* -- tcp forwarding */
185 struct permission_set local_perms;
186 struct permission_set remote_perms;
188 /* -- X11 forwarding */
190 /* Saved X11 local (client) display. */
191 char *x11_saved_display;
193 /* Saved X11 authentication protocol name. */
194 char *x11_saved_proto;
196 /* Saved X11 authentication data. This is the real data. */
197 char *x11_saved_data;
198 u_int x11_saved_data_len;
200 /* Deadline after which all X11 connections are refused */
201 time_t x11_refuse_time;
204 * Fake X11 authentication data. This is what the server will be
205 * sending us; we should replace any occurrences of this by the
208 u_char *x11_fake_data;
209 u_int x11_fake_data_len;
211 /* AF_UNSPEC or AF_INET or AF_INET6 */
214 /* Channel timeouts by type */
215 struct ssh_channel_timeout *timeouts;
220 static void port_open_helper(struct ssh *ssh, Channel *c, char *rtype);
221 static const char *channel_rfwd_bind_host(const char *listen_host);
223 /* non-blocking connect helpers */
224 static int connect_next(struct channel_connect *);
225 static void channel_connect_ctx_free(struct channel_connect *);
226 static Channel *rdynamic_connect_prepare(struct ssh *, char *, char *);
227 static int rdynamic_connect_finish(struct ssh *, Channel *);
230 static void channel_handler_init(struct ssh_channels *sc);
232 /* -- channel core */
235 channel_init_channels(struct ssh *ssh)
237 struct ssh_channels *sc;
239 if ((sc = calloc(1, sizeof(*sc))) == NULL)
240 fatal_f("allocation failed");
241 sc->channels_alloc = 10;
242 sc->channels = xcalloc(sc->channels_alloc, sizeof(*sc->channels));
243 sc->IPv4or6 = AF_UNSPEC;
244 channel_handler_init(sc);
250 channel_by_id(struct ssh *ssh, int id)
254 if (id < 0 || (u_int)id >= ssh->chanctxt->channels_alloc) {
255 logit_f("%d: bad id", id);
258 c = ssh->chanctxt->channels[id];
260 logit_f("%d: bad id: channel free", id);
267 channel_by_remote_id(struct ssh *ssh, u_int remote_id)
272 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
273 c = ssh->chanctxt->channels[i];
274 if (c != NULL && c->have_remote_id && c->remote_id == remote_id)
281 * Returns the channel if it is allowed to receive protocol messages.
282 * Private channels, like listening sockets, may not receive messages.
285 channel_lookup(struct ssh *ssh, int id)
289 if ((c = channel_by_id(ssh, id)) == NULL)
293 case SSH_CHANNEL_X11_OPEN:
294 case SSH_CHANNEL_LARVAL:
295 case SSH_CHANNEL_CONNECTING:
296 case SSH_CHANNEL_DYNAMIC:
297 case SSH_CHANNEL_RDYNAMIC_OPEN:
298 case SSH_CHANNEL_RDYNAMIC_FINISH:
299 case SSH_CHANNEL_OPENING:
300 case SSH_CHANNEL_OPEN:
301 case SSH_CHANNEL_ABANDONED:
302 case SSH_CHANNEL_MUX_PROXY:
305 logit("Non-public channel %d, type %d.", id, c->type);
310 * Add a timeout for open channels whose c->ctype (or c->xctype if it is set)
311 * match type_pattern.
314 channel_add_timeout(struct ssh *ssh, const char *type_pattern,
317 struct ssh_channels *sc = ssh->chanctxt;
319 debug2_f("channel type \"%s\" timeout %d seconds",
320 type_pattern, timeout_secs);
321 sc->timeouts = xrecallocarray(sc->timeouts, sc->ntimeouts,
322 sc->ntimeouts + 1, sizeof(*sc->timeouts));
323 sc->timeouts[sc->ntimeouts].type_pattern = xstrdup(type_pattern);
324 sc->timeouts[sc->ntimeouts].timeout_secs = timeout_secs;
328 /* Clears all previously-added channel timeouts */
330 channel_clear_timeouts(struct ssh *ssh)
332 struct ssh_channels *sc = ssh->chanctxt;
335 debug3_f("clearing");
336 for (i = 0; i < sc->ntimeouts; i++)
337 free(sc->timeouts[i].type_pattern);
344 lookup_timeout(struct ssh *ssh, const char *type)
346 struct ssh_channels *sc = ssh->chanctxt;
349 for (i = 0; i < sc->ntimeouts; i++) {
350 if (match_pattern(type, sc->timeouts[i].type_pattern))
351 return sc->timeouts[i].timeout_secs;
358 * Sets "extended type" of a channel; used by session layer to add additional
359 * information about channel types (e.g. shell, login, subsystem) that can then
360 * be used to select timeouts.
361 * Will reset c->inactive_deadline as a side-effect.
364 channel_set_xtype(struct ssh *ssh, int id, const char *xctype)
368 if ((c = channel_by_id(ssh, id)) == NULL)
369 fatal_f("missing channel %d", id);
370 if (c->xctype != NULL)
372 c->xctype = xstrdup(xctype);
373 /* Type has changed, so look up inactivity deadline again */
374 c->inactive_deadline = lookup_timeout(ssh, c->xctype);
375 debug2_f("labeled channel %d as %s (inactive timeout %u)", id, xctype,
376 c->inactive_deadline);
380 * Register filedescriptors for a channel, used when allocating a channel or
381 * when the channel consumer/producer is ready, e.g. shell exec'd
384 channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
385 int extusage, int nonblock, int is_tty)
390 (void)fcntl(rfd, F_SETFD, FD_CLOEXEC);
391 if (wfd != -1 && wfd != rfd)
392 (void)fcntl(wfd, F_SETFD, FD_CLOEXEC);
393 if (efd != -1 && efd != rfd && efd != wfd)
394 (void)fcntl(efd, F_SETFD, FD_CLOEXEC);
398 c->sock = (rfd == wfd) ? rfd : -1;
400 c->extended_usage = extusage;
402 if ((c->isatty = is_tty) != 0)
403 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
405 /* XXX: Later AIX versions can't push as much data to tty */
406 c->wfd_isatty = is_tty || isatty(c->wfd);
409 /* enable nonblocking mode */
410 c->restore_block = 0;
411 if (nonblock == CHANNEL_NONBLOCK_STDIO) {
413 * Special handling for stdio file descriptors: do not set
414 * non-blocking mode if they are TTYs. Otherwise prepare to
415 * restore their blocking state on exit to avoid interfering
416 * with other programs that follow.
418 if (rfd != -1 && !isatty(rfd) &&
419 (val = fcntl(rfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
420 c->restore_flags[0] = val;
421 c->restore_block |= CHANNEL_RESTORE_RFD;
424 if (wfd != -1 && !isatty(wfd) &&
425 (val = fcntl(wfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
426 c->restore_flags[1] = val;
427 c->restore_block |= CHANNEL_RESTORE_WFD;
430 if (efd != -1 && !isatty(efd) &&
431 (val = fcntl(efd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
432 c->restore_flags[2] = val;
433 c->restore_block |= CHANNEL_RESTORE_EFD;
436 } else if (nonblock) {
447 * Allocate a new channel object and set its type and socket.
450 channel_new(struct ssh *ssh, char *ctype, int type, int rfd, int wfd, int efd,
451 u_int window, u_int maxpack, int extusage, const char *remote_name,
454 struct ssh_channels *sc = ssh->chanctxt;
459 /* Try to find a free slot where to put the new channel. */
460 for (i = 0; i < sc->channels_alloc; i++) {
461 if (sc->channels[i] == NULL) {
462 /* Found a free slot. */
467 if (i >= sc->channels_alloc) {
469 * There are no free slots. Take last+1 slot and expand
472 found = sc->channels_alloc;
473 if (sc->channels_alloc > CHANNELS_MAX_CHANNELS)
474 fatal_f("internal error: channels_alloc %d too big",
476 sc->channels = xrecallocarray(sc->channels, sc->channels_alloc,
477 sc->channels_alloc + 10, sizeof(*sc->channels));
478 sc->channels_alloc += 10;
479 debug2("channel: expanding %d", sc->channels_alloc);
481 /* Initialize and return new channel. */
482 c = sc->channels[found] = xcalloc(1, sizeof(Channel));
483 if ((c->input = sshbuf_new()) == NULL ||
484 (c->output = sshbuf_new()) == NULL ||
485 (c->extended = sshbuf_new()) == NULL)
486 fatal_f("sshbuf_new failed");
487 if ((r = sshbuf_set_max_size(c->input, CHAN_INPUT_MAX)) != 0)
488 fatal_fr(r, "sshbuf_set_max_size");
489 c->ostate = CHAN_OUTPUT_OPEN;
490 c->istate = CHAN_INPUT_OPEN;
491 channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, 0);
495 c->local_window = window;
496 c->local_window_max = window;
497 c->local_maxpacket = maxpack;
498 c->remote_name = xstrdup(remote_name);
500 c->delayed = 1; /* prevent call to channel_post handler */
501 c->inactive_deadline = lookup_timeout(ssh, c->ctype);
502 TAILQ_INIT(&c->status_confirms);
503 debug("channel %d: new %s [%s] (inactive timeout: %u)",
504 found, c->ctype, remote_name, c->inactive_deadline);
509 channel_close_fd(struct ssh *ssh, Channel *c, int *fdp)
516 /* restore blocking */
517 if (*fdp == c->rfd &&
518 (c->restore_block & CHANNEL_RESTORE_RFD) != 0)
519 (void)fcntl(*fdp, F_SETFL, c->restore_flags[0]);
520 else if (*fdp == c->wfd &&
521 (c->restore_block & CHANNEL_RESTORE_WFD) != 0)
522 (void)fcntl(*fdp, F_SETFL, c->restore_flags[1]);
523 else if (*fdp == c->efd &&
524 (c->restore_block & CHANNEL_RESTORE_EFD) != 0)
525 (void)fcntl(*fdp, F_SETFL, c->restore_flags[2]);
527 if (*fdp == c->rfd) {
528 c->io_want &= ~SSH_CHAN_IO_RFD;
529 c->io_ready &= ~SSH_CHAN_IO_RFD;
533 if (*fdp == c->wfd) {
534 c->io_want &= ~SSH_CHAN_IO_WFD;
535 c->io_ready &= ~SSH_CHAN_IO_WFD;
539 if (*fdp == c->efd) {
540 c->io_want &= ~SSH_CHAN_IO_EFD;
541 c->io_ready &= ~SSH_CHAN_IO_EFD;
545 if (*fdp == c->sock) {
546 c->io_want &= ~SSH_CHAN_IO_SOCK;
547 c->io_ready &= ~SSH_CHAN_IO_SOCK;
553 *fdp = -1; /* probably redundant */
557 /* Close all channel fd/socket. */
559 channel_close_fds(struct ssh *ssh, Channel *c)
561 int sock = c->sock, rfd = c->rfd, wfd = c->wfd, efd = c->efd;
563 channel_close_fd(ssh, c, &c->sock);
565 channel_close_fd(ssh, c, &c->rfd);
566 if (wfd != sock && wfd != rfd)
567 channel_close_fd(ssh, c, &c->wfd);
568 if (efd != sock && efd != rfd && efd != wfd)
569 channel_close_fd(ssh, c, &c->efd);
573 fwd_perm_clear(struct permission *perm)
575 free(perm->host_to_connect);
576 free(perm->listen_host);
577 free(perm->listen_path);
578 memset(perm, 0, sizeof(*perm));
581 /* Returns an printable name for the specified forwarding permission list */
583 fwd_ident(int who, int where)
585 if (who == FORWARD_ADM) {
586 if (where == FORWARD_LOCAL)
587 return "admin local";
588 else if (where == FORWARD_REMOTE)
589 return "admin remote";
590 } else if (who == FORWARD_USER) {
591 if (where == FORWARD_LOCAL)
593 else if (where == FORWARD_REMOTE)
594 return "user remote";
596 fatal("Unknown forward permission list %d/%d", who, where);
599 /* Returns the forwarding permission list for the specified direction */
600 static struct permission_set *
601 permission_set_get(struct ssh *ssh, int where)
603 struct ssh_channels *sc = ssh->chanctxt;
607 return &sc->local_perms;
610 return &sc->remote_perms;
613 fatal_f("invalid forwarding direction %d", where);
617 /* Returns pointers to the specified forwarding list and its element count */
619 permission_set_get_array(struct ssh *ssh, int who, int where,
620 struct permission ***permpp, u_int **npermpp)
622 struct permission_set *pset = permission_set_get(ssh, where);
626 *permpp = &pset->permitted_user;
627 *npermpp = &pset->num_permitted_user;
630 *permpp = &pset->permitted_admin;
631 *npermpp = &pset->num_permitted_admin;
634 fatal_f("invalid forwarding client %d", who);
638 /* Adds an entry to the specified forwarding list */
640 permission_set_add(struct ssh *ssh, int who, int where,
641 const char *host_to_connect, int port_to_connect,
642 const char *listen_host, const char *listen_path, int listen_port,
645 struct permission **permp;
648 permission_set_get_array(ssh, who, where, &permp, &npermp);
650 if (*npermp >= INT_MAX)
651 fatal_f("%s overflow", fwd_ident(who, where));
653 *permp = xrecallocarray(*permp, *npermp, *npermp + 1, sizeof(**permp));
655 #define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
656 (*permp)[n].host_to_connect = MAYBE_DUP(host_to_connect);
657 (*permp)[n].port_to_connect = port_to_connect;
658 (*permp)[n].listen_host = MAYBE_DUP(listen_host);
659 (*permp)[n].listen_path = MAYBE_DUP(listen_path);
660 (*permp)[n].listen_port = listen_port;
661 (*permp)[n].downstream = downstream;
667 mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
669 struct ssh_channels *sc = ssh->chanctxt;
670 struct permission_set *pset = &sc->local_perms;
671 struct permission *perm;
675 for (i = 0; i < pset->num_permitted_user; i++) {
676 perm = &pset->permitted_user[i];
677 if (perm->downstream != c)
680 /* cancel on the server, since mux client is gone */
681 debug("channel %d: cleanup remote forward for %s:%u",
682 c->self, perm->listen_host, perm->listen_port);
683 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
684 (r = sshpkt_put_cstring(ssh,
685 "cancel-tcpip-forward")) != 0 ||
686 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
687 (r = sshpkt_put_cstring(ssh,
688 channel_rfwd_bind_host(perm->listen_host))) != 0 ||
689 (r = sshpkt_put_u32(ssh, perm->listen_port)) != 0 ||
690 (r = sshpkt_send(ssh)) != 0) {
691 fatal_fr(r, "channel %i", c->self);
693 fwd_perm_clear(perm); /* unregister */
697 /* Free the channel and close its fd/socket. */
699 channel_free(struct ssh *ssh, Channel *c)
701 struct ssh_channels *sc = ssh->chanctxt;
705 struct channel_confirm *cc;
707 for (n = 0, i = 0; i < sc->channels_alloc; i++) {
708 if ((other = sc->channels[i]) == NULL)
711 /* detach from mux client and prepare for closing */
712 if (c->type == SSH_CHANNEL_MUX_CLIENT &&
713 other->type == SSH_CHANNEL_MUX_PROXY &&
714 other->mux_ctx == c) {
715 other->mux_ctx = NULL;
716 other->type = SSH_CHANNEL_OPEN;
717 other->istate = CHAN_INPUT_CLOSED;
718 other->ostate = CHAN_OUTPUT_CLOSED;
721 debug("channel %d: free: %s, nchannels %u", c->self,
722 c->remote_name ? c->remote_name : "???", n);
724 if (c->type == SSH_CHANNEL_MUX_CLIENT) {
725 mux_remove_remote_forwardings(ssh, c);
728 } else if (c->type == SSH_CHANNEL_MUX_LISTENER) {
733 if (log_level_get() >= SYSLOG_LEVEL_DEBUG3) {
734 s = channel_open_message(ssh);
735 debug3("channel %d: status: %s", c->self, s);
739 channel_close_fds(ssh, c);
740 sshbuf_free(c->input);
741 sshbuf_free(c->output);
742 sshbuf_free(c->extended);
743 c->input = c->output = c->extended = NULL;
744 free(c->remote_name);
745 c->remote_name = NULL;
748 free(c->listening_addr);
749 c->listening_addr = NULL;
752 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
753 if (cc->abandon_cb != NULL)
754 cc->abandon_cb(ssh, c, cc->ctx);
755 TAILQ_REMOVE(&c->status_confirms, cc, entry);
756 freezero(cc, sizeof(*cc));
758 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
759 c->filter_cleanup(ssh, c->self, c->filter_ctx);
760 sc->channels[c->self] = NULL;
761 freezero(c, sizeof(*c));
765 channel_free_all(struct ssh *ssh)
768 struct ssh_channels *sc = ssh->chanctxt;
770 for (i = 0; i < sc->channels_alloc; i++)
771 if (sc->channels[i] != NULL)
772 channel_free(ssh, sc->channels[i]);
776 sc->channels_alloc = 0;
778 free(sc->x11_saved_display);
779 sc->x11_saved_display = NULL;
781 free(sc->x11_saved_proto);
782 sc->x11_saved_proto = NULL;
784 free(sc->x11_saved_data);
785 sc->x11_saved_data = NULL;
786 sc->x11_saved_data_len = 0;
788 free(sc->x11_fake_data);
789 sc->x11_fake_data = NULL;
790 sc->x11_fake_data_len = 0;
794 * Closes the sockets/fds of all channels. This is used to close extra file
795 * descriptors after a fork.
798 channel_close_all(struct ssh *ssh)
802 for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
803 if (ssh->chanctxt->channels[i] != NULL)
804 channel_close_fds(ssh, ssh->chanctxt->channels[i]);
808 * Stop listening to channels.
811 channel_stop_listening(struct ssh *ssh)
816 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
817 c = ssh->chanctxt->channels[i];
820 case SSH_CHANNEL_AUTH_SOCKET:
821 case SSH_CHANNEL_PORT_LISTENER:
822 case SSH_CHANNEL_RPORT_LISTENER:
823 case SSH_CHANNEL_X11_LISTENER:
824 case SSH_CHANNEL_UNIX_LISTENER:
825 case SSH_CHANNEL_RUNIX_LISTENER:
826 channel_close_fd(ssh, c, &c->sock);
827 channel_free(ssh, c);
835 * Returns true if no channel has too much buffered data, and false if one or
836 * more channel is overfull.
839 channel_not_very_much_buffered_data(struct ssh *ssh)
842 u_int maxsize = ssh_packet_get_maxsize(ssh);
845 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
846 c = ssh->chanctxt->channels[i];
847 if (c == NULL || c->type != SSH_CHANNEL_OPEN)
849 if (sshbuf_len(c->output) > maxsize) {
850 debug2("channel %d: big output buffer %zu > %u",
851 c->self, sshbuf_len(c->output), maxsize);
858 /* Returns true if any channel is still open. */
860 channel_still_open(struct ssh *ssh)
865 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
866 c = ssh->chanctxt->channels[i];
870 case SSH_CHANNEL_X11_LISTENER:
871 case SSH_CHANNEL_PORT_LISTENER:
872 case SSH_CHANNEL_RPORT_LISTENER:
873 case SSH_CHANNEL_MUX_LISTENER:
874 case SSH_CHANNEL_CLOSED:
875 case SSH_CHANNEL_AUTH_SOCKET:
876 case SSH_CHANNEL_DYNAMIC:
877 case SSH_CHANNEL_RDYNAMIC_OPEN:
878 case SSH_CHANNEL_CONNECTING:
879 case SSH_CHANNEL_ZOMBIE:
880 case SSH_CHANNEL_ABANDONED:
881 case SSH_CHANNEL_UNIX_LISTENER:
882 case SSH_CHANNEL_RUNIX_LISTENER:
884 case SSH_CHANNEL_LARVAL:
886 case SSH_CHANNEL_OPENING:
887 case SSH_CHANNEL_OPEN:
888 case SSH_CHANNEL_RDYNAMIC_FINISH:
889 case SSH_CHANNEL_X11_OPEN:
890 case SSH_CHANNEL_MUX_CLIENT:
891 case SSH_CHANNEL_MUX_PROXY:
894 fatal_f("bad channel type %d", c->type);
901 /* Returns the id of an open channel suitable for keepaliving */
903 channel_find_open(struct ssh *ssh)
908 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
909 c = ssh->chanctxt->channels[i];
910 if (c == NULL || !c->have_remote_id)
913 case SSH_CHANNEL_CLOSED:
914 case SSH_CHANNEL_DYNAMIC:
915 case SSH_CHANNEL_RDYNAMIC_OPEN:
916 case SSH_CHANNEL_RDYNAMIC_FINISH:
917 case SSH_CHANNEL_X11_LISTENER:
918 case SSH_CHANNEL_PORT_LISTENER:
919 case SSH_CHANNEL_RPORT_LISTENER:
920 case SSH_CHANNEL_MUX_LISTENER:
921 case SSH_CHANNEL_MUX_CLIENT:
922 case SSH_CHANNEL_MUX_PROXY:
923 case SSH_CHANNEL_OPENING:
924 case SSH_CHANNEL_CONNECTING:
925 case SSH_CHANNEL_ZOMBIE:
926 case SSH_CHANNEL_ABANDONED:
927 case SSH_CHANNEL_UNIX_LISTENER:
928 case SSH_CHANNEL_RUNIX_LISTENER:
930 case SSH_CHANNEL_LARVAL:
931 case SSH_CHANNEL_AUTH_SOCKET:
932 case SSH_CHANNEL_OPEN:
933 case SSH_CHANNEL_X11_OPEN:
936 fatal_f("bad channel type %d", c->type);
943 /* Returns the state of the channel's extended usage flag */
945 channel_format_extended_usage(const Channel *c)
950 switch (c->extended_usage) {
951 case CHAN_EXTENDED_WRITE:
953 case CHAN_EXTENDED_READ:
955 case CHAN_EXTENDED_IGNORE:
963 channel_format_status(const Channel *c)
967 xasprintf(&ret, "t%d [%s] %s%u i%u/%zu o%u/%zu e[%s]/%zu "
968 "fd %d/%d/%d sock %d cc %d io 0x%02x/0x%02x",
969 c->type, c->xctype != NULL ? c->xctype : c->ctype,
970 c->have_remote_id ? "r" : "nr", c->remote_id,
971 c->istate, sshbuf_len(c->input),
972 c->ostate, sshbuf_len(c->output),
973 channel_format_extended_usage(c), sshbuf_len(c->extended),
974 c->rfd, c->wfd, c->efd, c->sock, c->ctl_chan,
975 c->io_want, c->io_ready);
980 * Returns a message describing the currently open forwarded connections,
981 * suitable for sending to the client. The message contains crlf pairs for
985 channel_open_message(struct ssh *ssh)
993 if ((buf = sshbuf_new()) == NULL)
994 fatal_f("sshbuf_new");
995 if ((r = sshbuf_putf(buf,
996 "The following connections are open:\r\n")) != 0)
997 fatal_fr(r, "sshbuf_putf");
998 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
999 c = ssh->chanctxt->channels[i];
1003 case SSH_CHANNEL_X11_LISTENER:
1004 case SSH_CHANNEL_PORT_LISTENER:
1005 case SSH_CHANNEL_RPORT_LISTENER:
1006 case SSH_CHANNEL_CLOSED:
1007 case SSH_CHANNEL_AUTH_SOCKET:
1008 case SSH_CHANNEL_ZOMBIE:
1009 case SSH_CHANNEL_ABANDONED:
1010 case SSH_CHANNEL_MUX_LISTENER:
1011 case SSH_CHANNEL_UNIX_LISTENER:
1012 case SSH_CHANNEL_RUNIX_LISTENER:
1014 case SSH_CHANNEL_LARVAL:
1015 case SSH_CHANNEL_OPENING:
1016 case SSH_CHANNEL_CONNECTING:
1017 case SSH_CHANNEL_DYNAMIC:
1018 case SSH_CHANNEL_RDYNAMIC_OPEN:
1019 case SSH_CHANNEL_RDYNAMIC_FINISH:
1020 case SSH_CHANNEL_OPEN:
1021 case SSH_CHANNEL_X11_OPEN:
1022 case SSH_CHANNEL_MUX_PROXY:
1023 case SSH_CHANNEL_MUX_CLIENT:
1024 cp = channel_format_status(c);
1025 if ((r = sshbuf_putf(buf, " #%d %.300s (%s)\r\n",
1026 c->self, c->remote_name, cp)) != 0) {
1028 fatal_fr(r, "sshbuf_putf");
1033 fatal_f("bad channel type %d", c->type);
1037 if ((ret = sshbuf_dup_string(buf)) == NULL)
1038 fatal_f("sshbuf_dup_string");
1044 open_preamble(struct ssh *ssh, const char *where, Channel *c, const char *type)
1048 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1049 (r = sshpkt_put_cstring(ssh, type)) != 0 ||
1050 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1051 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1052 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
1053 fatal_r(r, "%s: channel %i: open", where, c->self);
1058 channel_send_open(struct ssh *ssh, int id)
1060 Channel *c = channel_lookup(ssh, id);
1064 logit("channel_send_open: %d: bad id", id);
1067 debug2("channel %d: send open", id);
1068 open_preamble(ssh, __func__, c, c->ctype);
1069 if ((r = sshpkt_send(ssh)) != 0)
1070 fatal_fr(r, "channel %i", c->self);
1074 channel_request_start(struct ssh *ssh, int id, char *service, int wantconfirm)
1076 Channel *c = channel_lookup(ssh, id);
1080 logit_f("%d: unknown channel id", id);
1083 if (!c->have_remote_id)
1084 fatal_f("channel %d: no remote id", c->self);
1086 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1087 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
1088 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1089 (r = sshpkt_put_cstring(ssh, service)) != 0 ||
1090 (r = sshpkt_put_u8(ssh, wantconfirm)) != 0) {
1091 fatal_fr(r, "channel %i", c->self);
1096 channel_register_status_confirm(struct ssh *ssh, int id,
1097 channel_confirm_cb *cb, channel_confirm_abandon_cb *abandon_cb, void *ctx)
1099 struct channel_confirm *cc;
1102 if ((c = channel_lookup(ssh, id)) == NULL)
1103 fatal_f("%d: bad id", id);
1105 cc = xcalloc(1, sizeof(*cc));
1107 cc->abandon_cb = abandon_cb;
1109 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
1113 channel_register_open_confirm(struct ssh *ssh, int id,
1114 channel_open_fn *fn, void *ctx)
1116 Channel *c = channel_lookup(ssh, id);
1119 logit_f("%d: bad id", id);
1122 c->open_confirm = fn;
1123 c->open_confirm_ctx = ctx;
1127 channel_register_cleanup(struct ssh *ssh, int id,
1128 channel_callback_fn *fn, int do_close)
1130 Channel *c = channel_by_id(ssh, id);
1133 logit_f("%d: bad id", id);
1136 c->detach_user = fn;
1137 c->detach_close = do_close;
1141 channel_cancel_cleanup(struct ssh *ssh, int id)
1143 Channel *c = channel_by_id(ssh, id);
1146 logit_f("%d: bad id", id);
1149 c->detach_user = NULL;
1150 c->detach_close = 0;
1154 channel_register_filter(struct ssh *ssh, int id, channel_infilter_fn *ifn,
1155 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1157 Channel *c = channel_lookup(ssh, id);
1160 logit_f("%d: bad id", id);
1163 c->input_filter = ifn;
1164 c->output_filter = ofn;
1165 c->filter_ctx = ctx;
1166 c->filter_cleanup = cfn;
1170 channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
1171 int extusage, int nonblock, int is_tty, u_int window_max)
1173 Channel *c = channel_lookup(ssh, id);
1176 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
1177 fatal("channel_activate for non-larval channel %d.", id);
1178 if (!c->have_remote_id)
1179 fatal_f("channel %d: no remote id", c->self);
1181 channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, is_tty);
1182 c->type = SSH_CHANNEL_OPEN;
1183 c->lastused = monotime();
1184 c->local_window = c->local_window_max = window_max;
1186 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
1187 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1188 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1189 (r = sshpkt_send(ssh)) != 0)
1190 fatal_fr(r, "channel %i", c->self);
1194 channel_pre_listener(struct ssh *ssh, Channel *c)
1196 c->io_want = SSH_CHAN_IO_SOCK_R;
1200 channel_pre_connecting(struct ssh *ssh, Channel *c)
1202 debug3("channel %d: waiting for connection", c->self);
1203 c->io_want = SSH_CHAN_IO_SOCK_W;
1207 channel_pre_open(struct ssh *ssh, Channel *c)
1210 if (c->istate == CHAN_INPUT_OPEN &&
1211 c->remote_window > 0 &&
1212 sshbuf_len(c->input) < c->remote_window &&
1213 sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1214 c->io_want |= SSH_CHAN_IO_RFD;
1215 if (c->ostate == CHAN_OUTPUT_OPEN ||
1216 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1217 if (sshbuf_len(c->output) > 0) {
1218 c->io_want |= SSH_CHAN_IO_WFD;
1219 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1220 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1221 debug2("channel %d: "
1222 "obuf_empty delayed efd %d/(%zu)", c->self,
1223 c->efd, sshbuf_len(c->extended));
1225 chan_obuf_empty(ssh, c);
1228 /** XXX check close conditions, too */
1229 if (c->efd != -1 && !(c->istate == CHAN_INPUT_CLOSED &&
1230 c->ostate == CHAN_OUTPUT_CLOSED)) {
1231 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1232 sshbuf_len(c->extended) > 0)
1233 c->io_want |= SSH_CHAN_IO_EFD_W;
1234 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
1235 (c->extended_usage == CHAN_EXTENDED_READ ||
1236 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1237 sshbuf_len(c->extended) < c->remote_window)
1238 c->io_want |= SSH_CHAN_IO_EFD_R;
1240 /* XXX: What about efd? races? */
1244 * This is a special state for X11 authentication spoofing. An opened X11
1245 * connection (when authentication spoofing is being done) remains in this
1246 * state until the first packet has been completely read. The authentication
1247 * data in that packet is then substituted by the real data if it matches the
1248 * fake data, and the channel is put into normal mode.
1249 * XXX All this happens at the client side.
1250 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1253 x11_open_helper(struct ssh *ssh, struct sshbuf *b)
1255 struct ssh_channels *sc = ssh->chanctxt;
1257 u_int proto_len, data_len;
1259 /* Is this being called after the refusal deadline? */
1260 if (sc->x11_refuse_time != 0 &&
1261 monotime() >= sc->x11_refuse_time) {
1262 verbose("Rejected X11 connection after ForwardX11Timeout "
1267 /* Check if the fixed size part of the packet is in buffer. */
1268 if (sshbuf_len(b) < 12)
1271 /* Parse the lengths of variable-length fields. */
1272 ucp = sshbuf_mutable_ptr(b);
1273 if (ucp[0] == 0x42) { /* Byte order MSB first. */
1274 proto_len = 256 * ucp[6] + ucp[7];
1275 data_len = 256 * ucp[8] + ucp[9];
1276 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
1277 proto_len = ucp[6] + 256 * ucp[7];
1278 data_len = ucp[8] + 256 * ucp[9];
1280 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1285 /* Check if the whole packet is in buffer. */
1287 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
1290 /* Check if authentication protocol matches. */
1291 if (proto_len != strlen(sc->x11_saved_proto) ||
1292 memcmp(ucp + 12, sc->x11_saved_proto, proto_len) != 0) {
1293 debug2("X11 connection uses different authentication protocol.");
1296 /* Check if authentication data matches our fake data. */
1297 if (data_len != sc->x11_fake_data_len ||
1298 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1299 sc->x11_fake_data, sc->x11_fake_data_len) != 0) {
1300 debug2("X11 auth data does not match fake data.");
1303 /* Check fake data length */
1304 if (sc->x11_fake_data_len != sc->x11_saved_data_len) {
1305 error("X11 fake_data_len %d != saved_data_len %d",
1306 sc->x11_fake_data_len, sc->x11_saved_data_len);
1310 * Received authentication protocol and data match
1311 * our fake data. Substitute the fake data with real
1314 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
1315 sc->x11_saved_data, sc->x11_saved_data_len);
1320 channel_force_close(struct ssh *ssh, Channel *c, int abandon)
1322 debug3_f("channel %d: forcibly closing", c->self);
1323 if (c->istate == CHAN_INPUT_OPEN)
1324 chan_read_failed(ssh, c);
1325 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1326 sshbuf_reset(c->input);
1327 chan_ibuf_empty(ssh, c);
1329 if (c->ostate == CHAN_OUTPUT_OPEN ||
1330 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1331 sshbuf_reset(c->output);
1332 chan_write_failed(ssh, c);
1335 c->detach_user(ssh, c->self, 1, NULL);
1337 channel_close_fd(ssh, c, &c->efd);
1339 c->type = SSH_CHANNEL_ABANDONED;
1340 /* exempt from inactivity timeouts */
1341 c->inactive_deadline = 0;
1346 channel_pre_x11_open(struct ssh *ssh, Channel *c)
1348 int ret = x11_open_helper(ssh, c->output);
1350 /* c->force_drain = 1; */
1353 c->type = SSH_CHANNEL_OPEN;
1354 c->lastused = monotime();
1355 channel_pre_open(ssh, c);
1356 } else if (ret == -1) {
1357 logit("X11 connection rejected because of wrong "
1359 debug2("X11 rejected %d i%d/o%d",
1360 c->self, c->istate, c->ostate);
1361 channel_force_close(ssh, c, 0);
1366 channel_pre_mux_client(struct ssh *ssh, Channel *c)
1369 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1370 sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1371 c->io_want |= SSH_CHAN_IO_RFD;
1372 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1373 /* clear buffer immediately (discard any partial packet) */
1374 sshbuf_reset(c->input);
1375 chan_ibuf_empty(ssh, c);
1376 /* Start output drain. XXX just kill chan? */
1377 chan_rcvd_oclose(ssh, c);
1379 if (c->ostate == CHAN_OUTPUT_OPEN ||
1380 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1381 if (sshbuf_len(c->output) > 0)
1382 c->io_want |= SSH_CHAN_IO_WFD;
1383 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1384 chan_obuf_empty(ssh, c);
1388 /* try to decode a socks4 header */
1390 channel_decode_socks4(Channel *c, struct sshbuf *input, struct sshbuf *output)
1394 u_int len, have, i, found, need;
1399 u_int16_t dest_port;
1400 struct in_addr dest_addr;
1404 debug2("channel %d: decode socks4", c->self);
1406 have = sshbuf_len(input);
1407 len = sizeof(s4_req);
1410 p = sshbuf_ptr(input);
1413 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1414 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1415 debug2("channel %d: socks4a request", c->self);
1416 /* ... and needs an extra string (the hostname) */
1419 /* Check for terminating NUL on the string(s) */
1420 for (found = 0, i = len; i < have; i++) {
1427 /* the peer is probably sending garbage */
1428 debug("channel %d: decode socks4: too long",
1435 if ((r = sshbuf_get(input, &s4_req.version, 1)) != 0 ||
1436 (r = sshbuf_get(input, &s4_req.command, 1)) != 0 ||
1437 (r = sshbuf_get(input, &s4_req.dest_port, 2)) != 0 ||
1438 (r = sshbuf_get(input, &s4_req.dest_addr, 4)) != 0) {
1439 debug_r(r, "channels %d: decode socks4", c->self);
1442 have = sshbuf_len(input);
1443 p = sshbuf_ptr(input);
1444 if (memchr(p, '\0', have) == NULL) {
1445 error("channel %d: decode socks4: unterminated user", c->self);
1449 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1450 len++; /* trailing '\0' */
1451 strlcpy(username, p, sizeof(username));
1452 if ((r = sshbuf_consume(input, len)) != 0)
1453 fatal_fr(r, "channel %d: consume", c->self);
1456 if (need == 1) { /* SOCKS4: one string */
1457 host = inet_ntoa(s4_req.dest_addr);
1458 c->path = xstrdup(host);
1459 } else { /* SOCKS4A: two strings */
1460 have = sshbuf_len(input);
1461 p = sshbuf_ptr(input);
1462 if (memchr(p, '\0', have) == NULL) {
1463 error("channel %d: decode socks4a: host not nul "
1464 "terminated", c->self);
1468 debug2("channel %d: decode socks4a: host %s/%d",
1470 len++; /* trailing '\0' */
1471 if (len > NI_MAXHOST) {
1472 error("channel %d: hostname \"%.100s\" too long",
1476 c->path = xstrdup(p);
1477 if ((r = sshbuf_consume(input, len)) != 0)
1478 fatal_fr(r, "channel %d: consume", c->self);
1480 c->host_port = ntohs(s4_req.dest_port);
1482 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1483 c->self, c->path, c->host_port, s4_req.command);
1485 if (s4_req.command != 1) {
1486 debug("channel %d: cannot handle: %s cn %d",
1487 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1490 s4_rsp.version = 0; /* vn: 0 for reply */
1491 s4_rsp.command = 90; /* cd: req granted */
1492 s4_rsp.dest_port = 0; /* ignored */
1493 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1494 if ((r = sshbuf_put(output, &s4_rsp, sizeof(s4_rsp))) != 0)
1495 fatal_fr(r, "channel %d: append reply", c->self);
1499 /* try to decode a socks5 header */
1500 #define SSH_SOCKS5_AUTHDONE 0x1000
1501 #define SSH_SOCKS5_NOAUTH 0x00
1502 #define SSH_SOCKS5_IPV4 0x01
1503 #define SSH_SOCKS5_DOMAIN 0x03
1504 #define SSH_SOCKS5_IPV6 0x04
1505 #define SSH_SOCKS5_CONNECT 0x01
1506 #define SSH_SOCKS5_SUCCESS 0x00
1509 channel_decode_socks5(Channel *c, struct sshbuf *input, struct sshbuf *output)
1511 /* XXX use get/put_u8 instead of trusting struct padding */
1518 u_int16_t dest_port;
1519 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1521 u_int have, need, i, found, nmethods, addrlen, af;
1524 debug2("channel %d: decode socks5", c->self);
1525 p = sshbuf_ptr(input);
1528 have = sshbuf_len(input);
1529 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1530 /* format: ver | nmethods | methods */
1534 if (have < nmethods + 2)
1536 /* look for method: "NO AUTHENTICATION REQUIRED" */
1537 for (found = 0, i = 2; i < nmethods + 2; i++) {
1538 if (p[i] == SSH_SOCKS5_NOAUTH) {
1544 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1548 if ((r = sshbuf_consume(input, nmethods + 2)) != 0)
1549 fatal_fr(r, "channel %d: consume", c->self);
1550 /* version, method */
1551 if ((r = sshbuf_put_u8(output, 0x05)) != 0 ||
1552 (r = sshbuf_put_u8(output, SSH_SOCKS5_NOAUTH)) != 0)
1553 fatal_fr(r, "channel %d: append reply", c->self);
1554 c->flags |= SSH_SOCKS5_AUTHDONE;
1555 debug2("channel %d: socks5 auth done", c->self);
1556 return 0; /* need more */
1558 debug2("channel %d: socks5 post auth", c->self);
1559 if (have < sizeof(s5_req)+1)
1560 return 0; /* need more */
1561 memcpy(&s5_req, p, sizeof(s5_req));
1562 if (s5_req.version != 0x05 ||
1563 s5_req.command != SSH_SOCKS5_CONNECT ||
1564 s5_req.reserved != 0x00) {
1565 debug2("channel %d: only socks5 connect supported", c->self);
1568 switch (s5_req.atyp){
1569 case SSH_SOCKS5_IPV4:
1573 case SSH_SOCKS5_DOMAIN:
1574 addrlen = p[sizeof(s5_req)];
1577 case SSH_SOCKS5_IPV6:
1582 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1585 need = sizeof(s5_req) + addrlen + 2;
1586 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1590 if ((r = sshbuf_consume(input, sizeof(s5_req))) != 0)
1591 fatal_fr(r, "channel %d: consume", c->self);
1592 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1593 /* host string length */
1594 if ((r = sshbuf_consume(input, 1)) != 0)
1595 fatal_fr(r, "channel %d: consume", c->self);
1597 if ((r = sshbuf_get(input, &dest_addr, addrlen)) != 0 ||
1598 (r = sshbuf_get(input, &dest_port, 2)) != 0) {
1599 debug_r(r, "channel %d: parse addr/port", c->self);
1602 dest_addr[addrlen] = '\0';
1605 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1606 if (addrlen >= NI_MAXHOST) {
1607 error("channel %d: dynamic request: socks5 hostname "
1608 "\"%.100s\" too long", c->self, dest_addr);
1611 c->path = xstrdup(dest_addr);
1613 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1615 c->path = xstrdup(ntop);
1617 c->host_port = ntohs(dest_port);
1619 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1620 c->self, c->path, c->host_port, s5_req.command);
1622 s5_rsp.version = 0x05;
1623 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1624 s5_rsp.reserved = 0; /* ignored */
1625 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1626 dest_port = 0; /* ignored */
1628 if ((r = sshbuf_put(output, &s5_rsp, sizeof(s5_rsp))) != 0 ||
1629 (r = sshbuf_put_u32(output, ntohl(INADDR_ANY))) != 0 ||
1630 (r = sshbuf_put(output, &dest_port, sizeof(dest_port))) != 0)
1631 fatal_fr(r, "channel %d: append reply", c->self);
1636 channel_connect_stdio_fwd(struct ssh *ssh,
1637 const char *host_to_connect, int port_to_connect,
1638 int in, int out, int nonblock)
1642 debug_f("%s:%d", host_to_connect, port_to_connect);
1644 c = channel_new(ssh, "stdio-forward", SSH_CHANNEL_OPENING, in, out,
1645 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1646 0, "stdio-forward", nonblock);
1648 c->path = xstrdup(host_to_connect);
1649 c->host_port = port_to_connect;
1650 c->listening_port = 0;
1653 channel_register_fds(ssh, c, in, out, -1, 0, 1, 0);
1654 port_open_helper(ssh, c, port_to_connect == PORT_STREAMLOCAL ?
1655 "direct-streamlocal@openssh.com" : "direct-tcpip");
1660 /* dynamic port forwarding */
1662 channel_pre_dynamic(struct ssh *ssh, Channel *c)
1669 have = sshbuf_len(c->input);
1670 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1671 /* sshbuf_dump(c->input, stderr); */
1672 /* check if the fixed size part of the packet is in buffer. */
1675 c->io_want |= SSH_CHAN_IO_RFD;
1678 /* try to guess the protocol */
1679 p = sshbuf_ptr(c->input);
1680 /* XXX sshbuf_peek_u8? */
1683 ret = channel_decode_socks4(c, c->input, c->output);
1686 ret = channel_decode_socks5(c, c->input, c->output);
1693 chan_mark_dead(ssh, c);
1694 } else if (ret == 0) {
1695 debug2("channel %d: pre_dynamic: need more", c->self);
1697 c->io_want |= SSH_CHAN_IO_RFD;
1698 if (sshbuf_len(c->output))
1699 c->io_want |= SSH_CHAN_IO_WFD;
1701 /* switch to the next state */
1702 c->type = SSH_CHANNEL_OPENING;
1703 port_open_helper(ssh, c, "direct-tcpip");
1707 /* simulate read-error */
1709 rdynamic_close(struct ssh *ssh, Channel *c)
1711 c->type = SSH_CHANNEL_OPEN;
1712 channel_force_close(ssh, c, 0);
1715 /* reverse dynamic port forwarding */
1717 channel_before_prepare_io_rdynamic(struct ssh *ssh, Channel *c)
1723 have = sshbuf_len(c->output);
1724 debug2("channel %d: pre_rdynamic: have %d", c->self, have);
1725 /* sshbuf_dump(c->output, stderr); */
1727 if (c->flags & CHAN_EOF_RCVD) {
1728 if ((r = sshbuf_consume(c->output, have)) != 0)
1729 fatal_fr(r, "channel %d: consume", c->self);
1730 rdynamic_close(ssh, c);
1733 /* check if the fixed size part of the packet is in buffer. */
1736 /* try to guess the protocol */
1737 p = sshbuf_ptr(c->output);
1740 /* switch input/output for reverse forwarding */
1741 ret = channel_decode_socks4(c, c->output, c->input);
1744 ret = channel_decode_socks5(c, c->output, c->input);
1751 rdynamic_close(ssh, c);
1752 } else if (ret == 0) {
1753 debug2("channel %d: pre_rdynamic: need more", c->self);
1754 /* send socks request to peer */
1755 len = sshbuf_len(c->input);
1756 if (len > 0 && len < c->remote_window) {
1757 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
1758 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1759 (r = sshpkt_put_stringb(ssh, c->input)) != 0 ||
1760 (r = sshpkt_send(ssh)) != 0) {
1761 fatal_fr(r, "channel %i: rdynamic", c->self);
1763 if ((r = sshbuf_consume(c->input, len)) != 0)
1764 fatal_fr(r, "channel %d: consume", c->self);
1765 c->remote_window -= len;
1767 } else if (rdynamic_connect_finish(ssh, c) < 0) {
1768 /* the connect failed */
1769 rdynamic_close(ssh, c);
1773 /* This is our fake X11 server socket. */
1775 channel_post_x11_listener(struct ssh *ssh, Channel *c)
1778 struct sockaddr_storage addr;
1779 int r, newsock, oerrno, remote_port;
1781 char buf[16384], *remote_ipaddr;
1783 if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1786 debug("X11 connection requested.");
1787 addrlen = sizeof(addr);
1788 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1789 if (c->single_connection) {
1791 debug2("single_connection: closing X11 listener.");
1792 channel_close_fd(ssh, c, &c->sock);
1793 chan_mark_dead(ssh, c);
1796 if (newsock == -1) {
1797 if (errno != EINTR && errno != EWOULDBLOCK &&
1798 errno != ECONNABORTED)
1799 error("accept: %.100s", strerror(errno));
1800 if (errno == EMFILE || errno == ENFILE)
1801 c->notbefore = monotime() + 1;
1804 set_nodelay(newsock);
1805 remote_ipaddr = get_peer_ipaddr(newsock);
1806 remote_port = get_peer_port(newsock);
1807 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1808 remote_ipaddr, remote_port);
1810 nc = channel_new(ssh, "x11-connection",
1811 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1812 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1813 open_preamble(ssh, __func__, nc, "x11");
1814 if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1815 (r = sshpkt_put_u32(ssh, remote_port)) != 0) {
1816 fatal_fr(r, "channel %i: reply", c->self);
1818 if ((r = sshpkt_send(ssh)) != 0)
1819 fatal_fr(r, "channel %i: send", c->self);
1820 free(remote_ipaddr);
1824 port_open_helper(struct ssh *ssh, Channel *c, char *rtype)
1826 char *local_ipaddr = get_local_ipaddr(c->sock);
1827 int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
1828 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1829 int remote_port = get_peer_port(c->sock);
1832 if (remote_port == -1) {
1833 /* Fake addr/port to appease peers that validate it (Tectia) */
1834 free(remote_ipaddr);
1835 remote_ipaddr = xstrdup("127.0.0.1");
1836 remote_port = 65535;
1839 free(c->remote_name);
1840 xasprintf(&c->remote_name,
1841 "%s: listening port %d for %.100s port %d, "
1842 "connect from %.200s port %d to %.100s port %d",
1843 rtype, c->listening_port, c->path, c->host_port,
1844 remote_ipaddr, remote_port, local_ipaddr, local_port);
1846 open_preamble(ssh, __func__, c, rtype);
1847 if (strcmp(rtype, "direct-tcpip") == 0) {
1848 /* target host, port */
1849 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1850 (r = sshpkt_put_u32(ssh, c->host_port)) != 0)
1851 fatal_fr(r, "channel %i: reply", c->self);
1852 } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1854 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
1855 fatal_fr(r, "channel %i: reply", c->self);
1856 } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1858 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
1859 fatal_fr(r, "channel %i: reply", c->self);
1861 /* listen address, port */
1862 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1863 (r = sshpkt_put_u32(ssh, local_port)) != 0)
1864 fatal_fr(r, "channel %i: reply", c->self);
1866 if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1867 /* reserved for future owner/mode info */
1868 if ((r = sshpkt_put_cstring(ssh, "")) != 0)
1869 fatal_fr(r, "channel %i: reply", c->self);
1871 /* originator host and port */
1872 if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1873 (r = sshpkt_put_u32(ssh, (u_int)remote_port)) != 0)
1874 fatal_fr(r, "channel %i: reply", c->self);
1876 if ((r = sshpkt_send(ssh)) != 0)
1877 fatal_fr(r, "channel %i: send", c->self);
1878 free(remote_ipaddr);
1883 channel_set_x11_refuse_time(struct ssh *ssh, time_t refuse_time)
1885 ssh->chanctxt->x11_refuse_time = refuse_time;
1889 * This socket is listening for connections to a forwarded TCP/IP port.
1892 channel_post_port_listener(struct ssh *ssh, Channel *c)
1895 struct sockaddr_storage addr;
1896 int newsock, nextstate;
1900 if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1903 debug("Connection to port %d forwarding to %.100s port %d requested.",
1904 c->listening_port, c->path, c->host_port);
1906 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1907 nextstate = SSH_CHANNEL_OPENING;
1908 rtype = "forwarded-tcpip";
1909 } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1910 nextstate = SSH_CHANNEL_OPENING;
1911 rtype = "forwarded-streamlocal@openssh.com";
1912 } else if (c->host_port == PORT_STREAMLOCAL) {
1913 nextstate = SSH_CHANNEL_OPENING;
1914 rtype = "direct-streamlocal@openssh.com";
1915 } else if (c->host_port == 0) {
1916 nextstate = SSH_CHANNEL_DYNAMIC;
1917 rtype = "dynamic-tcpip";
1919 nextstate = SSH_CHANNEL_OPENING;
1920 rtype = "direct-tcpip";
1923 addrlen = sizeof(addr);
1924 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1925 if (newsock == -1) {
1926 if (errno != EINTR && errno != EWOULDBLOCK &&
1927 errno != ECONNABORTED)
1928 error("accept: %.100s", strerror(errno));
1929 if (errno == EMFILE || errno == ENFILE)
1930 c->notbefore = monotime() + 1;
1933 if (c->host_port != PORT_STREAMLOCAL)
1934 set_nodelay(newsock);
1935 nc = channel_new(ssh, rtype, nextstate, newsock, newsock, -1,
1936 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1937 nc->listening_port = c->listening_port;
1938 nc->host_port = c->host_port;
1939 if (c->path != NULL)
1940 nc->path = xstrdup(c->path);
1942 if (nextstate != SSH_CHANNEL_DYNAMIC)
1943 port_open_helper(ssh, nc, rtype);
1947 * This is the authentication agent socket listening for connections from
1951 channel_post_auth_listener(struct ssh *ssh, Channel *c)
1955 struct sockaddr_storage addr;
1958 if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1961 addrlen = sizeof(addr);
1962 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1963 if (newsock == -1) {
1964 error("accept from auth socket: %.100s", strerror(errno));
1965 if (errno == EMFILE || errno == ENFILE)
1966 c->notbefore = monotime() + 1;
1969 nc = channel_new(ssh, "agent-connection",
1970 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1971 c->local_window_max, c->local_maxpacket,
1972 0, "accepted auth socket", 1);
1973 open_preamble(ssh, __func__, nc, "auth-agent@openssh.com");
1974 if ((r = sshpkt_send(ssh)) != 0)
1975 fatal_fr(r, "channel %i", c->self);
1979 channel_post_connecting(struct ssh *ssh, Channel *c)
1981 int err = 0, sock, isopen, r;
1982 socklen_t sz = sizeof(err);
1984 if ((c->io_ready & SSH_CHAN_IO_SOCK_W) == 0)
1986 if (!c->have_remote_id)
1987 fatal_f("channel %d: no remote id", c->self);
1988 /* for rdynamic the OPEN_CONFIRMATION has been sent already */
1989 isopen = (c->type == SSH_CHANNEL_RDYNAMIC_FINISH);
1991 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) == -1) {
1993 error("getsockopt SO_ERROR failed");
1997 /* Non-blocking connection completed */
1998 debug("channel %d: connected to %s port %d",
1999 c->self, c->connect_ctx.host, c->connect_ctx.port);
2000 channel_connect_ctx_free(&c->connect_ctx);
2001 c->type = SSH_CHANNEL_OPEN;
2002 c->lastused = monotime();
2004 /* no message necessary */
2006 if ((r = sshpkt_start(ssh,
2007 SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
2008 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2009 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
2010 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
2011 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
2012 (r = sshpkt_send(ssh)) != 0)
2013 fatal_fr(r, "channel %i open confirm", c->self);
2017 if (err == EINTR || err == EAGAIN || err == EINPROGRESS)
2020 /* Non-blocking connection failed */
2021 debug("channel %d: connection failed: %s", c->self, strerror(err));
2023 /* Try next address, if any */
2024 if ((sock = connect_next(&c->connect_ctx)) == -1) {
2025 /* Exhausted all addresses for this destination */
2026 error("connect_to %.100s port %d: failed.",
2027 c->connect_ctx.host, c->connect_ctx.port);
2028 channel_connect_ctx_free(&c->connect_ctx);
2030 rdynamic_close(ssh, c);
2032 if ((r = sshpkt_start(ssh,
2033 SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
2034 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2035 (r = sshpkt_put_u32(ssh,
2036 SSH2_OPEN_CONNECT_FAILED)) != 0 ||
2037 (r = sshpkt_put_cstring(ssh, strerror(err))) != 0 ||
2038 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2039 (r = sshpkt_send(ssh)) != 0)
2040 fatal_fr(r, "channel %i: failure", c->self);
2041 chan_mark_dead(ssh, c);
2045 /* New non-blocking connection in progress */
2047 c->sock = c->rfd = c->wfd = sock;
2051 channel_handle_rfd(struct ssh *ssh, Channel *c)
2053 char buf[CHAN_RBUF];
2056 size_t nr = 0, have, avail, maxlen = CHANNEL_MAX_READ;
2057 int pty_zeroread = 0;
2060 /* Bug on AIX: read(1) can return 0 for a non-closed fd */
2061 pty_zeroread = c->isatty;
2064 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
2066 if (!force && (c->io_ready & SSH_CHAN_IO_RFD) == 0)
2068 if ((avail = sshbuf_avail(c->input)) == 0)
2069 return 1; /* Shouldn't happen */
2072 * For "simple" channels (i.e. not datagram or filtered), we can
2073 * read directly to the channel buffer.
2075 if (!pty_zeroread && c->input_filter == NULL && !c->datagram) {
2076 /* Only OPEN channels have valid rwin */
2077 if (c->type == SSH_CHANNEL_OPEN) {
2078 if ((have = sshbuf_len(c->input)) >= c->remote_window)
2079 return 1; /* shouldn't happen */
2080 if (maxlen > c->remote_window - have)
2081 maxlen = c->remote_window - have;
2085 if ((r = sshbuf_read(c->rfd, c->input, maxlen, &nr)) != 0) {
2086 if (errno == EINTR || (!force &&
2087 (errno == EAGAIN || errno == EWOULDBLOCK)))
2089 debug2("channel %d: read failed rfd %d maxlen %zu: %s",
2090 c->self, c->rfd, maxlen, ssh_err(r));
2094 c->lastused = monotime();
2099 len = read(c->rfd, buf, sizeof(buf));
2100 /* fixup AIX zero-length read with errno set to look more like errors */
2101 if (pty_zeroread && len == 0 && errno != 0)
2103 if (len == -1 && (errno == EINTR ||
2104 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
2106 if (len < 0 || (!pty_zeroread && len == 0)) {
2107 debug2("channel %d: read<=0 rfd %d len %zd: %s",
2108 c->self, c->rfd, len,
2109 len == 0 ? "closed" : strerror(errno));
2111 if (c->type != SSH_CHANNEL_OPEN) {
2112 debug2("channel %d: not open", c->self);
2113 chan_mark_dead(ssh, c);
2116 chan_read_failed(ssh, c);
2120 c->lastused = monotime();
2121 if (c->input_filter != NULL) {
2122 if (c->input_filter(ssh, c, buf, len) == -1) {
2123 debug2("channel %d: filter stops", c->self);
2124 chan_read_failed(ssh, c);
2126 } else if (c->datagram) {
2127 if ((r = sshbuf_put_string(c->input, buf, len)) != 0)
2128 fatal_fr(r, "channel %i: put datagram", c->self);
2129 } else if ((r = sshbuf_put(c->input, buf, len)) != 0)
2130 fatal_fr(r, "channel %i: put data", c->self);
2136 channel_handle_wfd(struct ssh *ssh, Channel *c)
2139 u_char *data = NULL, *buf; /* XXX const; need filter API change */
2140 size_t dlen, olen = 0;
2143 if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
2145 if (sshbuf_len(c->output) == 0)
2148 /* Send buffered output data to the socket. */
2149 olen = sshbuf_len(c->output);
2150 if (c->output_filter != NULL) {
2151 if ((buf = c->output_filter(ssh, c, &data, &dlen)) == NULL) {
2152 debug2("channel %d: filter stops", c->self);
2153 if (c->type != SSH_CHANNEL_OPEN)
2154 chan_mark_dead(ssh, c);
2156 chan_write_failed(ssh, c);
2159 } else if (c->datagram) {
2160 if ((r = sshbuf_get_string(c->output, &data, &dlen)) != 0)
2161 fatal_fr(r, "channel %i: get datagram", c->self);
2164 buf = data = sshbuf_mutable_ptr(c->output);
2165 dlen = sshbuf_len(c->output);
2169 /* ignore truncated writes, datagrams might get lost */
2170 len = write(c->wfd, buf, dlen);
2172 if (len == -1 && (errno == EINTR || errno == EAGAIN ||
2173 errno == EWOULDBLOCK))
2181 /* XXX: Later AIX versions can't push as much data to tty */
2183 dlen = MINIMUM(dlen, 8*1024);
2186 len = write(c->wfd, buf, dlen);
2188 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
2192 if (c->type != SSH_CHANNEL_OPEN) {
2193 debug2("channel %d: not open", c->self);
2194 chan_mark_dead(ssh, c);
2197 chan_write_failed(ssh, c);
2201 c->lastused = monotime();
2202 #ifndef BROKEN_TCGETATTR_ICANON
2203 if (c->isatty && dlen >= 1 && buf[0] != '\r') {
2204 if (tcgetattr(c->wfd, &tio) == 0 &&
2205 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
2207 * Simulate echo to reduce the impact of
2208 * traffic analysis. We need to match the
2209 * size of a SSH2_MSG_CHANNEL_DATA message
2210 * (4 byte channel id + buf)
2212 if ((r = sshpkt_msg_ignore(ssh, 4+len)) != 0 ||
2213 (r = sshpkt_send(ssh)) != 0)
2214 fatal_fr(r, "channel %i: ignore", c->self);
2217 #endif /* BROKEN_TCGETATTR_ICANON */
2218 if ((r = sshbuf_consume(c->output, len)) != 0)
2219 fatal_fr(r, "channel %i: consume", c->self);
2221 c->local_consumed += olen - sshbuf_len(c->output);
2227 channel_handle_efd_write(struct ssh *ssh, Channel *c)
2232 if ((c->io_ready & SSH_CHAN_IO_EFD_W) == 0)
2234 if (sshbuf_len(c->extended) == 0)
2237 len = write(c->efd, sshbuf_ptr(c->extended),
2238 sshbuf_len(c->extended));
2239 debug2("channel %d: written %zd to efd %d", c->self, len, c->efd);
2240 if (len == -1 && (errno == EINTR || errno == EAGAIN ||
2241 errno == EWOULDBLOCK))
2244 debug2("channel %d: closing write-efd %d", c->self, c->efd);
2245 channel_close_fd(ssh, c, &c->efd);
2247 if ((r = sshbuf_consume(c->extended, len)) != 0)
2248 fatal_fr(r, "channel %i: consume", c->self);
2249 c->local_consumed += len;
2250 c->lastused = monotime();
2256 channel_handle_efd_read(struct ssh *ssh, Channel *c)
2258 char buf[CHAN_RBUF];
2262 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
2264 if (!force && (c->io_ready & SSH_CHAN_IO_EFD_R) == 0)
2267 len = read(c->efd, buf, sizeof(buf));
2268 debug2("channel %d: read %zd from efd %d", c->self, len, c->efd);
2269 if (len == -1 && (errno == EINTR || ((errno == EAGAIN ||
2270 errno == EWOULDBLOCK) && !force)))
2273 debug2("channel %d: closing read-efd %d", c->self, c->efd);
2274 channel_close_fd(ssh, c, &c->efd);
2277 c->lastused = monotime();
2278 if (c->extended_usage == CHAN_EXTENDED_IGNORE)
2279 debug3("channel %d: discard efd", c->self);
2280 else if ((r = sshbuf_put(c->extended, buf, len)) != 0)
2281 fatal_fr(r, "channel %i: append", c->self);
2286 channel_handle_efd(struct ssh *ssh, Channel *c)
2291 /** XXX handle drain efd, too */
2293 if (c->extended_usage == CHAN_EXTENDED_WRITE)
2294 return channel_handle_efd_write(ssh, c);
2295 else if (c->extended_usage == CHAN_EXTENDED_READ ||
2296 c->extended_usage == CHAN_EXTENDED_IGNORE)
2297 return channel_handle_efd_read(ssh, c);
2303 channel_check_window(struct ssh *ssh, Channel *c)
2307 if (c->type == SSH_CHANNEL_OPEN &&
2308 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
2309 ((c->local_window_max - c->local_window >
2310 c->local_maxpacket*3) ||
2311 c->local_window < c->local_window_max/2) &&
2312 c->local_consumed > 0) {
2313 if (!c->have_remote_id)
2314 fatal_f("channel %d: no remote id", c->self);
2315 if ((r = sshpkt_start(ssh,
2316 SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
2317 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2318 (r = sshpkt_put_u32(ssh, c->local_consumed)) != 0 ||
2319 (r = sshpkt_send(ssh)) != 0) {
2320 fatal_fr(r, "channel %i", c->self);
2322 debug2("channel %d: window %d sent adjust %d", c->self,
2323 c->local_window, c->local_consumed);
2324 c->local_window += c->local_consumed;
2325 c->local_consumed = 0;
2331 channel_post_open(struct ssh *ssh, Channel *c)
2333 channel_handle_rfd(ssh, c);
2334 channel_handle_wfd(ssh, c);
2335 channel_handle_efd(ssh, c);
2336 channel_check_window(ssh, c);
2340 read_mux(struct ssh *ssh, Channel *c, u_int need)
2342 char buf[CHAN_RBUF];
2347 if (sshbuf_len(c->input) < need) {
2348 rlen = need - sshbuf_len(c->input);
2349 len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
2350 if (len == -1 && (errno == EINTR || errno == EAGAIN))
2351 return sshbuf_len(c->input);
2353 debug2("channel %d: ctl read<=0 rfd %d len %zd",
2354 c->self, c->rfd, len);
2355 chan_read_failed(ssh, c);
2357 } else if ((r = sshbuf_put(c->input, buf, len)) != 0)
2358 fatal_fr(r, "channel %i: append", c->self);
2360 return sshbuf_len(c->input);
2364 channel_post_mux_client_read(struct ssh *ssh, Channel *c)
2368 if ((c->io_ready & SSH_CHAN_IO_RFD) == 0)
2370 if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
2376 * Don't not read past the precise end of packets to
2377 * avoid disrupting fd passing.
2379 if (read_mux(ssh, c, 4) < 4) /* read header */
2381 /* XXX sshbuf_peek_u32 */
2382 need = PEEK_U32(sshbuf_ptr(c->input));
2383 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
2384 if (need > CHANNEL_MUX_MAX_PACKET) {
2385 debug2("channel %d: packet too big %u > %u",
2386 c->self, CHANNEL_MUX_MAX_PACKET, need);
2387 chan_rcvd_oclose(ssh, c);
2390 if (read_mux(ssh, c, need + 4) < need + 4) /* read body */
2392 if (c->mux_rcb(ssh, c) != 0) {
2393 debug("channel %d: mux_rcb failed", c->self);
2394 chan_mark_dead(ssh, c);
2400 channel_post_mux_client_write(struct ssh *ssh, Channel *c)
2405 if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
2407 if (sshbuf_len(c->output) == 0)
2410 len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
2411 if (len == -1 && (errno == EINTR || errno == EAGAIN))
2414 chan_mark_dead(ssh, c);
2417 if ((r = sshbuf_consume(c->output, len)) != 0)
2418 fatal_fr(r, "channel %i: consume", c->self);
2422 channel_post_mux_client(struct ssh *ssh, Channel *c)
2424 channel_post_mux_client_read(ssh, c);
2425 channel_post_mux_client_write(ssh, c);
2429 channel_post_mux_listener(struct ssh *ssh, Channel *c)
2432 struct sockaddr_storage addr;
2438 if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
2441 debug("multiplexing control connection");
2444 * Accept connection on control socket
2446 memset(&addr, 0, sizeof(addr));
2447 addrlen = sizeof(addr);
2448 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
2450 error_f("accept: %s", strerror(errno));
2451 if (errno == EMFILE || errno == ENFILE)
2452 c->notbefore = monotime() + 1;
2456 if (getpeereid(newsock, &euid, &egid) == -1) {
2457 error_f("getpeereid failed: %s", strerror(errno));
2461 if ((euid != 0) && (getuid() != euid)) {
2462 error("multiplex uid mismatch: peer euid %u != uid %u",
2463 (u_int)euid, (u_int)getuid());
2467 nc = channel_new(ssh, "mux-control", SSH_CHANNEL_MUX_CLIENT,
2468 newsock, newsock, -1, c->local_window_max,
2469 c->local_maxpacket, 0, "mux-control", 1);
2470 nc->mux_rcb = c->mux_rcb;
2471 debug3_f("new mux channel %d fd %d", nc->self, nc->sock);
2472 /* establish state */
2473 nc->mux_rcb(ssh, nc);
2474 /* mux state transitions must not elicit protocol messages */
2475 nc->flags |= CHAN_LOCAL;
2479 channel_handler_init(struct ssh_channels *sc)
2481 chan_fn **pre, **post;
2483 if ((pre = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*pre))) == NULL ||
2484 (post = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*post))) == NULL)
2485 fatal_f("allocation failed");
2487 pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2488 pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2489 pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2490 pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2491 pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2492 pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
2493 pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2494 pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2495 pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2496 pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2497 pre[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_pre_connecting;
2498 pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2499 pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2501 post[SSH_CHANNEL_OPEN] = &channel_post_open;
2502 post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2503 post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2504 post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2505 post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
2506 post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2507 post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2508 post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2509 post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2510 post[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_post_connecting;
2511 post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2512 post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2514 sc->channel_pre = pre;
2515 sc->channel_post = post;
2518 /* gc dead channels */
2520 channel_garbage_collect(struct ssh *ssh, Channel *c)
2524 if (c->detach_user != NULL) {
2525 if (!chan_is_dead(ssh, c, c->detach_close))
2528 debug2("channel %d: gc: notify user", c->self);
2529 c->detach_user(ssh, c->self, 0, NULL);
2530 /* if we still have a callback */
2531 if (c->detach_user != NULL)
2533 debug2("channel %d: gc: user detached", c->self);
2535 if (!chan_is_dead(ssh, c, 1))
2537 debug2("channel %d: garbage collecting", c->self);
2538 channel_free(ssh, c);
2541 enum channel_table { CHAN_PRE, CHAN_POST };
2544 channel_handler(struct ssh *ssh, int table, struct timespec *timeout)
2546 struct ssh_channels *sc = ssh->chanctxt;
2547 chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
2553 for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
2554 c = sc->channels[i];
2557 /* Try to keep IO going while rekeying */
2558 if (ssh_packet_is_rekeying(ssh) && c->type != SSH_CHANNEL_OPEN)
2561 if (table == CHAN_PRE)
2566 if (ftab[c->type] != NULL) {
2567 if (table == CHAN_PRE &&
2568 c->type == SSH_CHANNEL_OPEN &&
2569 c->inactive_deadline != 0 && c->lastused != 0 &&
2570 now >= c->lastused + c->inactive_deadline) {
2571 /* channel closed for inactivity */
2572 verbose("channel %d: closing after %u seconds "
2573 "of inactivity", c->self,
2574 c->inactive_deadline);
2575 channel_force_close(ssh, c, 1);
2576 } else if (c->notbefore <= now) {
2577 /* Run handlers that are not paused. */
2578 (*ftab[c->type])(ssh, c);
2579 /* inactivity timeouts must interrupt poll() */
2580 if (timeout != NULL &&
2581 c->type == SSH_CHANNEL_OPEN &&
2583 c->inactive_deadline != 0) {
2584 ptimeout_deadline_monotime(timeout,
2585 c->lastused + c->inactive_deadline);
2587 } else if (timeout != NULL) {
2589 * Arrange for poll() wakeup when channel pause
2592 ptimeout_deadline_monotime(timeout,
2596 channel_garbage_collect(ssh, c);
2601 * Create sockets before preparing IO.
2602 * This is necessary for things that need to happen after reading
2603 * the network-input but need to be completed before IO event setup, e.g.
2604 * because they may create new channels.
2607 channel_before_prepare_io(struct ssh *ssh)
2609 struct ssh_channels *sc = ssh->chanctxt;
2613 for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
2614 c = sc->channels[i];
2617 if (c->type == SSH_CHANNEL_RDYNAMIC_OPEN)
2618 channel_before_prepare_io_rdynamic(ssh, c);
2623 dump_channel_poll(const char *func, const char *what, Channel *c,
2624 u_int pollfd_offset, struct pollfd *pfd)
2626 #ifdef DEBUG_CHANNEL_POLL
2627 debug3("%s: channel %d: %s r%d w%d e%d s%d c->pfds [ %d %d %d %d ] "
2628 "io_want 0x%02x io_ready 0x%02x pfd[%u].fd=%d "
2629 "pfd.ev 0x%02x pfd.rev 0x%02x", func, c->self, what,
2630 c->rfd, c->wfd, c->efd, c->sock,
2631 c->pfds[0], c->pfds[1], c->pfds[2], c->pfds[3],
2632 c->io_want, c->io_ready,
2633 pollfd_offset, pfd->fd, pfd->events, pfd->revents);
2637 /* Prepare pollfd entries for a single channel */
2639 channel_prepare_pollfd(Channel *c, u_int *next_pollfd,
2640 struct pollfd *pfd, u_int npfd)
2642 u_int ev, p = *next_pollfd;
2647 /* Shouldn't happen */
2648 fatal_f("channel %d: bad pfd offset %u (max %u)",
2651 c->pfds[0] = c->pfds[1] = c->pfds[2] = c->pfds[3] = -1;
2655 * This is a special case, since c->rfd might be the same as
2656 * c->wfd, c->efd and/or c->sock. Handle those here if they want
2661 if ((c->io_want & SSH_CHAN_IO_RFD) != 0)
2664 if (c->wfd == c->rfd) {
2665 if ((c->io_want & SSH_CHAN_IO_WFD) != 0)
2669 if (c->efd == c->rfd) {
2670 if ((c->io_want & SSH_CHAN_IO_EFD_R) != 0)
2672 if ((c->io_want & SSH_CHAN_IO_EFD_W) != 0)
2676 if (c->sock == c->rfd) {
2677 if ((c->io_want & SSH_CHAN_IO_SOCK_R) != 0)
2679 if ((c->io_want & SSH_CHAN_IO_SOCK_W) != 0)
2682 /* Pack a pfd entry if any event armed for this fd */
2687 dump_channel_poll(__func__, "rfd", c, p, &pfd[p]);
2691 /* prepare c->wfd if wanting IO and not already handled above */
2692 if (c->wfd != -1 && c->rfd != c->wfd) {
2694 if ((c->io_want & SSH_CHAN_IO_WFD))
2696 /* Pack a pfd entry if any event armed for this fd */
2701 dump_channel_poll(__func__, "wfd", c, p, &pfd[p]);
2705 /* prepare c->efd if wanting IO and not already handled above */
2706 if (c->efd != -1 && c->rfd != c->efd) {
2708 if ((c->io_want & SSH_CHAN_IO_EFD_R) != 0)
2710 if ((c->io_want & SSH_CHAN_IO_EFD_W) != 0)
2712 /* Pack a pfd entry if any event armed for this fd */
2717 dump_channel_poll(__func__, "efd", c, p, &pfd[p]);
2721 /* prepare c->sock if wanting IO and not already handled above */
2722 if (c->sock != -1 && c->rfd != c->sock) {
2724 if ((c->io_want & SSH_CHAN_IO_SOCK_R) != 0)
2726 if ((c->io_want & SSH_CHAN_IO_SOCK_W) != 0)
2728 /* Pack a pfd entry if any event armed for this fd */
2731 pfd[p].fd = c->sock;
2733 dump_channel_poll(__func__, "sock", c, p, &pfd[p]);
2740 /* * Allocate/prepare poll structure */
2742 channel_prepare_poll(struct ssh *ssh, struct pollfd **pfdp, u_int *npfd_allocp,
2743 u_int *npfd_activep, u_int npfd_reserved, struct timespec *timeout)
2745 struct ssh_channels *sc = ssh->chanctxt;
2746 u_int i, oalloc, p, npfd = npfd_reserved;
2748 channel_before_prepare_io(ssh); /* might create a new channel */
2749 /* clear out I/O flags from last poll */
2750 for (i = 0; i < sc->channels_alloc; i++) {
2751 if (sc->channels[i] == NULL)
2753 sc->channels[i]->io_want = sc->channels[i]->io_ready = 0;
2755 /* Allocate 4x pollfd for each channel (rfd, wfd, efd, sock) */
2756 if (sc->channels_alloc >= (INT_MAX / 4) - npfd_reserved)
2757 fatal_f("too many channels"); /* shouldn't happen */
2758 npfd += sc->channels_alloc * 4;
2759 if (npfd > *npfd_allocp) {
2760 *pfdp = xrecallocarray(*pfdp, *npfd_allocp,
2761 npfd, sizeof(**pfdp));
2762 *npfd_allocp = npfd;
2764 *npfd_activep = npfd_reserved;
2765 oalloc = sc->channels_alloc;
2767 channel_handler(ssh, CHAN_PRE, timeout);
2769 if (oalloc != sc->channels_alloc) {
2770 /* shouldn't happen */
2771 fatal_f("channels_alloc changed during CHAN_PRE "
2772 "(was %u, now %u)", oalloc, sc->channels_alloc);
2775 /* Prepare pollfd */
2777 for (i = 0; i < sc->channels_alloc; i++)
2778 channel_prepare_pollfd(sc->channels[i], &p, *pfdp, npfd);
2783 fd_ready(Channel *c, int p, struct pollfd *pfds, u_int npfd, int fd,
2784 const char *what, u_int revents_mask, u_int ready)
2786 struct pollfd *pfd = &pfds[p];
2790 if (p == -1 || (u_int)p >= npfd)
2791 fatal_f("channel %d: bad pfd %d (max %u)", c->self, p, npfd);
2792 dump_channel_poll(__func__, what, c, p, pfd);
2793 if (pfd->fd != fd) {
2794 fatal("channel %d: inconsistent %s fd=%d pollfd[%u].fd %d "
2795 "r%d w%d e%d s%d", c->self, what, fd, p, pfd->fd,
2796 c->rfd, c->wfd, c->efd, c->sock);
2798 if ((pfd->revents & POLLNVAL) != 0) {
2799 fatal("channel %d: invalid %s pollfd[%u].fd %d r%d w%d e%d s%d",
2800 c->self, what, p, pfd->fd, c->rfd, c->wfd, c->efd, c->sock);
2802 if ((pfd->revents & (revents_mask|POLLHUP|POLLERR)) != 0)
2803 c->io_ready |= ready & c->io_want;
2807 * After poll, perform any appropriate operations for channels which have
2811 channel_after_poll(struct ssh *ssh, struct pollfd *pfd, u_int npfd)
2813 struct ssh_channels *sc = ssh->chanctxt;
2818 #ifdef DEBUG_CHANNEL_POLL
2819 for (p = 0; p < (int)npfd; p++) {
2820 if (pfd[p].revents == 0)
2822 debug_f("pfd[%u].fd %d rev 0x%04x",
2823 p, pfd[p].fd, pfd[p].revents);
2827 /* Convert pollfd into c->io_ready */
2828 for (i = 0; i < sc->channels_alloc; i++) {
2829 c = sc->channels[i];
2832 /* if rfd is shared with efd/sock then wfd should be too */
2833 if (c->rfd != -1 && c->wfd != -1 && c->rfd != c->wfd &&
2834 (c->rfd == c->efd || c->rfd == c->sock)) {
2835 /* Shouldn't happen */
2836 fatal_f("channel %d: unexpected fds r%d w%d e%d s%d",
2837 c->self, c->rfd, c->wfd, c->efd, c->sock);
2840 /* rfd, potentially shared with wfd, efd and sock */
2841 if (c->rfd != -1 && (p = c->pfds[0]) != -1) {
2842 fd_ready(c, p, pfd, npfd, c->rfd,
2843 "rfd", POLLIN, SSH_CHAN_IO_RFD);
2844 if (c->rfd == c->wfd) {
2845 fd_ready(c, p, pfd, npfd, c->wfd,
2846 "wfd/r", POLLOUT, SSH_CHAN_IO_WFD);
2848 if (c->rfd == c->efd) {
2849 fd_ready(c, p, pfd, npfd, c->efd,
2850 "efdr/r", POLLIN, SSH_CHAN_IO_EFD_R);
2851 fd_ready(c, p, pfd, npfd, c->efd,
2852 "efdw/r", POLLOUT, SSH_CHAN_IO_EFD_W);
2854 if (c->rfd == c->sock) {
2855 fd_ready(c, p, pfd, npfd, c->sock,
2856 "sockr/r", POLLIN, SSH_CHAN_IO_SOCK_R);
2857 fd_ready(c, p, pfd, npfd, c->sock,
2858 "sockw/r", POLLOUT, SSH_CHAN_IO_SOCK_W);
2860 dump_channel_poll(__func__, "rfd", c, p, pfd);
2863 if (c->wfd != -1 && c->wfd != c->rfd &&
2864 (p = c->pfds[1]) != -1) {
2865 fd_ready(c, p, pfd, npfd, c->wfd,
2866 "wfd", POLLOUT, SSH_CHAN_IO_WFD);
2867 dump_channel_poll(__func__, "wfd", c, p, pfd);
2870 if (c->efd != -1 && c->efd != c->rfd &&
2871 (p = c->pfds[2]) != -1) {
2872 fd_ready(c, p, pfd, npfd, c->efd,
2873 "efdr", POLLIN, SSH_CHAN_IO_EFD_R);
2874 fd_ready(c, p, pfd, npfd, c->efd,
2875 "efdw", POLLOUT, SSH_CHAN_IO_EFD_W);
2876 dump_channel_poll(__func__, "efd", c, p, pfd);
2879 if (c->sock != -1 && c->sock != c->rfd &&
2880 (p = c->pfds[3]) != -1) {
2881 fd_ready(c, p, pfd, npfd, c->sock,
2882 "sockr", POLLIN, SSH_CHAN_IO_SOCK_R);
2883 fd_ready(c, p, pfd, npfd, c->sock,
2884 "sockw", POLLOUT, SSH_CHAN_IO_SOCK_W);
2885 dump_channel_poll(__func__, "sock", c, p, pfd);
2888 channel_handler(ssh, CHAN_POST, NULL);
2892 * Enqueue data for channels with open or draining c->input.
2893 * Returns non-zero if a packet was enqueued.
2896 channel_output_poll_input_open(struct ssh *ssh, Channel *c)
2902 if ((len = sshbuf_len(c->input)) == 0) {
2903 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2905 * input-buffer is empty and read-socket shutdown:
2906 * tell peer, that we will not send more data:
2908 * hack for extended data: delay EOF if EFD still
2911 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2912 debug2("channel %d: "
2913 "ibuf_empty delayed efd %d/(%zu)",
2914 c->self, c->efd, sshbuf_len(c->extended));
2916 chan_ibuf_empty(ssh, c);
2921 if (!c->have_remote_id)
2922 fatal_f("channel %d: no remote id", c->self);
2925 /* Check datagram will fit; drop if not */
2926 if ((r = sshbuf_get_string_direct(c->input, &pkt, &plen)) != 0)
2927 fatal_fr(r, "channel %i: get datagram", c->self);
2929 * XXX this does tail-drop on the datagram queue which is
2930 * usually suboptimal compared to head-drop. Better to have
2931 * backpressure at read time? (i.e. read + discard)
2933 if (plen > c->remote_window || plen > c->remote_maxpacket) {
2934 debug("channel %d: datagram too big", c->self);
2938 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2939 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2940 (r = sshpkt_put_string(ssh, pkt, plen)) != 0 ||
2941 (r = sshpkt_send(ssh)) != 0)
2942 fatal_fr(r, "channel %i: send datagram", c->self);
2943 c->remote_window -= plen;
2947 /* Enqueue packet for buffered data. */
2948 if (len > c->remote_window)
2949 len = c->remote_window;
2950 if (len > c->remote_maxpacket)
2951 len = c->remote_maxpacket;
2954 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2955 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2956 (r = sshpkt_put_string(ssh, sshbuf_ptr(c->input), len)) != 0 ||
2957 (r = sshpkt_send(ssh)) != 0)
2958 fatal_fr(r, "channel %i: send data", c->self);
2959 if ((r = sshbuf_consume(c->input, len)) != 0)
2960 fatal_fr(r, "channel %i: consume", c->self);
2961 c->remote_window -= len;
2966 * Enqueue data for channels with open c->extended in read mode.
2967 * Returns non-zero if a packet was enqueued.
2970 channel_output_poll_extended_read(struct ssh *ssh, Channel *c)
2975 if ((len = sshbuf_len(c->extended)) == 0)
2978 debug2("channel %d: rwin %u elen %zu euse %d", c->self,
2979 c->remote_window, sshbuf_len(c->extended), c->extended_usage);
2980 if (len > c->remote_window)
2981 len = c->remote_window;
2982 if (len > c->remote_maxpacket)
2983 len = c->remote_maxpacket;
2986 if (!c->have_remote_id)
2987 fatal_f("channel %d: no remote id", c->self);
2988 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA)) != 0 ||
2989 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2990 (r = sshpkt_put_u32(ssh, SSH2_EXTENDED_DATA_STDERR)) != 0 ||
2991 (r = sshpkt_put_string(ssh, sshbuf_ptr(c->extended), len)) != 0 ||
2992 (r = sshpkt_send(ssh)) != 0)
2993 fatal_fr(r, "channel %i: data", c->self);
2994 if ((r = sshbuf_consume(c->extended, len)) != 0)
2995 fatal_fr(r, "channel %i: consume", c->self);
2996 c->remote_window -= len;
2997 debug2("channel %d: sent ext data %zu", c->self, len);
3002 * If there is data to send to the connection, enqueue some of it now.
3003 * Returns non-zero if data was enqueued.
3006 channel_output_poll(struct ssh *ssh)
3008 struct ssh_channels *sc = ssh->chanctxt;
3013 for (i = 0; i < sc->channels_alloc; i++) {
3014 c = sc->channels[i];
3019 * We are only interested in channels that can have buffered
3022 if (c->type != SSH_CHANNEL_OPEN)
3024 if ((c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
3025 /* XXX is this true? */
3026 debug3("channel %d: will not send data after close",
3031 /* Get the amount of buffered data for this channel. */
3032 if (c->istate == CHAN_INPUT_OPEN ||
3033 c->istate == CHAN_INPUT_WAIT_DRAIN)
3034 ret |= channel_output_poll_input_open(ssh, c);
3035 /* Send extended data, i.e. stderr */
3036 if (!(c->flags & CHAN_EOF_SENT) &&
3037 c->extended_usage == CHAN_EXTENDED_READ)
3038 ret |= channel_output_poll_extended_read(ssh, c);
3043 /* -- mux proxy support */
3046 * When multiplexing channel messages for mux clients we have to deal
3047 * with downstream messages from the mux client and upstream messages
3048 * from the ssh server:
3049 * 1) Handling downstream messages is straightforward and happens
3050 * in channel_proxy_downstream():
3051 * - We forward all messages (mostly) unmodified to the server.
3052 * - However, in order to route messages from upstream to the correct
3053 * downstream client, we have to replace the channel IDs used by the
3054 * mux clients with a unique channel ID because the mux clients might
3055 * use conflicting channel IDs.
3056 * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
3057 * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
3058 * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
3059 * with the newly allocated channel ID.
3060 * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
3061 * channels and processed by channel_proxy_upstream(). The local channel ID
3062 * is then translated back to the original mux client ID.
3063 * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
3064 * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
3065 * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
3066 * downstream mux client are removed.
3067 * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
3068 * requires more work, because they are not addressed to a specific
3069 * channel. E.g. client_request_forwarded_tcpip() needs to figure
3070 * out whether the request is addressed to the local client or a
3071 * specific downstream client based on the listen-address/port.
3072 * 6) Agent and X11-Forwarding have a similar problem and are currently
3073 * not supported as the matching session/channel cannot be identified
3078 * receive packets from downstream mux clients:
3079 * channel callback fired on read from mux client, creates
3080 * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
3081 * on channel creation.
3084 channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
3087 struct sshbuf *original = NULL, *modified = NULL;
3089 char *ctype = NULL, *listen_host = NULL;
3093 u_int id, remote_id, listen_port;
3095 /* sshbuf_dump(downstream->input, stderr); */
3096 if ((r = sshbuf_get_string_direct(downstream->input, &cp, &have))
3098 error_fr(r, "parse");
3102 error_f("short message");
3106 /* skip padlen + type */
3109 if (ssh_packet_log_type(type))
3110 debug3_f("channel %u: down->up: type %u",
3111 downstream->self, type);
3114 case SSH2_MSG_CHANNEL_OPEN:
3115 if ((original = sshbuf_from(cp, have)) == NULL ||
3116 (modified = sshbuf_new()) == NULL) {
3120 if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
3121 (r = sshbuf_get_u32(original, &id)) != 0) {
3122 error_fr(r, "parse");
3125 c = channel_new(ssh, "mux-proxy", SSH_CHANNEL_MUX_PROXY,
3126 -1, -1, -1, 0, 0, 0, ctype, 1);
3127 c->mux_ctx = downstream; /* point to mux client */
3128 c->mux_downstream_id = id; /* original downstream id */
3129 if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
3130 (r = sshbuf_put_u32(modified, c->self)) != 0 ||
3131 (r = sshbuf_putb(modified, original)) != 0) {
3132 error_fr(r, "compose");
3133 channel_free(ssh, c);
3137 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
3139 * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
3140 * need to parse 'remote_id' instead of 'ctype'.
3142 if ((original = sshbuf_from(cp, have)) == NULL ||
3143 (modified = sshbuf_new()) == NULL) {
3147 if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
3148 (r = sshbuf_get_u32(original, &id)) != 0) {
3149 error_fr(r, "parse");
3152 c = channel_new(ssh, "mux-proxy", SSH_CHANNEL_MUX_PROXY,
3153 -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
3154 c->mux_ctx = downstream; /* point to mux client */
3155 c->mux_downstream_id = id;
3156 c->remote_id = remote_id;
3157 c->have_remote_id = 1;
3158 if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
3159 (r = sshbuf_put_u32(modified, c->self)) != 0 ||
3160 (r = sshbuf_putb(modified, original)) != 0) {
3161 error_fr(r, "compose");
3162 channel_free(ssh, c);
3166 case SSH2_MSG_GLOBAL_REQUEST:
3167 if ((original = sshbuf_from(cp, have)) == NULL) {
3171 if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
3172 error_fr(r, "parse");
3175 if (strcmp(ctype, "tcpip-forward") != 0) {
3176 error_f("unsupported request %s", ctype);
3179 if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
3180 (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
3181 (r = sshbuf_get_u32(original, &listen_port)) != 0) {
3182 error_fr(r, "parse");
3185 if (listen_port > 65535) {
3186 error_f("tcpip-forward for %s: bad port %u",
3187 listen_host, listen_port);
3190 /* Record that connection to this host/port is permitted. */
3191 permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL, "<mux>", -1,
3192 listen_host, NULL, (int)listen_port, downstream);
3195 case SSH2_MSG_CHANNEL_CLOSE:
3198 remote_id = PEEK_U32(cp);
3199 if ((c = channel_by_remote_id(ssh, remote_id)) != NULL) {
3200 if (c->flags & CHAN_CLOSE_RCVD)
3201 channel_free(ssh, c);
3203 c->flags |= CHAN_CLOSE_SENT;
3208 if ((r = sshpkt_start(ssh, type)) != 0 ||
3209 (r = sshpkt_putb(ssh, modified)) != 0 ||
3210 (r = sshpkt_send(ssh)) != 0) {
3211 error_fr(r, "send");
3215 if ((r = sshpkt_start(ssh, type)) != 0 ||
3216 (r = sshpkt_put(ssh, cp, have)) != 0 ||
3217 (r = sshpkt_send(ssh)) != 0) {
3218 error_fr(r, "send");
3226 sshbuf_free(original);
3227 sshbuf_free(modified);
3232 * receive packets from upstream server and de-multiplex packets
3233 * to correct downstream:
3234 * implemented as a helper for channel input handlers,
3235 * replaces local (proxy) channel ID with downstream channel ID.
3238 channel_proxy_upstream(Channel *c, int type, u_int32_t seq, struct ssh *ssh)
3240 struct sshbuf *b = NULL;
3241 Channel *downstream;
3242 const u_char *cp = NULL;
3247 * When receiving packets from the peer we need to check whether we
3248 * need to forward the packets to the mux client. In this case we
3249 * restore the original channel id and keep track of CLOSE messages,
3250 * so we can cleanup the channel.
3252 if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
3254 if ((downstream = c->mux_ctx) == NULL)
3257 case SSH2_MSG_CHANNEL_CLOSE:
3258 case SSH2_MSG_CHANNEL_DATA:
3259 case SSH2_MSG_CHANNEL_EOF:
3260 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
3261 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
3262 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
3263 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
3264 case SSH2_MSG_CHANNEL_SUCCESS:
3265 case SSH2_MSG_CHANNEL_FAILURE:
3266 case SSH2_MSG_CHANNEL_REQUEST:
3269 debug2_f("channel %u: unsupported type %u", c->self, type);
3272 if ((b = sshbuf_new()) == NULL) {
3273 error_f("alloc reply");
3276 /* get remaining payload (after id) */
3277 cp = sshpkt_ptr(ssh, &len);
3279 error_f("no packet");
3282 /* translate id and send to muxclient */
3283 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
3284 (r = sshbuf_put_u8(b, type)) != 0 ||
3285 (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
3286 (r = sshbuf_put(b, cp, len)) != 0 ||
3287 (r = sshbuf_put_stringb(downstream->output, b)) != 0) {
3288 error_fr(r, "compose muxclient");
3291 /* sshbuf_dump(b, stderr); */
3292 if (ssh_packet_log_type(type))
3293 debug3_f("channel %u: up->down: type %u", c->self, type);
3297 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
3298 /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
3299 if (cp && len > 4) {
3300 c->remote_id = PEEK_U32(cp);
3301 c->have_remote_id = 1;
3304 case SSH2_MSG_CHANNEL_CLOSE:
3305 if (c->flags & CHAN_CLOSE_SENT)
3306 channel_free(ssh, c);
3308 c->flags |= CHAN_CLOSE_RCVD;
3315 /* -- protocol input */
3317 /* Parse a channel ID from the current packet */
3319 channel_parse_id(struct ssh *ssh, const char *where, const char *what)
3324 if ((r = sshpkt_get_u32(ssh, &id)) != 0) {
3325 error_r(r, "%s: parse id", where);
3326 ssh_packet_disconnect(ssh, "Invalid %s message", what);
3329 error_r(r, "%s: bad channel id %u", where, id);
3330 ssh_packet_disconnect(ssh, "Invalid %s channel id", what);
3335 /* Lookup a channel from an ID in the current packet */
3337 channel_from_packet_id(struct ssh *ssh, const char *where, const char *what)
3339 int id = channel_parse_id(ssh, where, what);
3342 if ((c = channel_lookup(ssh, id)) == NULL) {
3343 ssh_packet_disconnect(ssh,
3344 "%s packet referred to nonexistent channel %d", what, id);
3350 channel_input_data(int type, u_int32_t seq, struct ssh *ssh)
3353 size_t data_len, win_len;
3354 Channel *c = channel_from_packet_id(ssh, __func__, "data");
3357 if (channel_proxy_upstream(c, type, seq, ssh))
3360 /* Ignore any data for non-open channels (might happen on close) */
3361 if (c->type != SSH_CHANNEL_OPEN &&
3362 c->type != SSH_CHANNEL_RDYNAMIC_OPEN &&
3363 c->type != SSH_CHANNEL_RDYNAMIC_FINISH &&
3364 c->type != SSH_CHANNEL_X11_OPEN)
3368 if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
3369 (r = sshpkt_get_end(ssh)) != 0)
3370 fatal_fr(r, "channel %i: get data", c->self);
3374 win_len += 4; /* string length header */
3377 * The sending side reduces its window as it sends data, so we
3378 * must 'fake' consumption of the data in order to ensure that window
3379 * updates are sent back. Otherwise the connection might deadlock.
3381 if (c->ostate != CHAN_OUTPUT_OPEN) {
3382 c->local_window -= win_len;
3383 c->local_consumed += win_len;
3387 if (win_len > c->local_maxpacket) {
3388 logit("channel %d: rcvd big packet %zu, maxpack %u",
3389 c->self, win_len, c->local_maxpacket);
3392 if (win_len > c->local_window) {
3393 logit("channel %d: rcvd too much data %zu, win %u",
3394 c->self, win_len, c->local_window);
3397 c->local_window -= win_len;
3400 if ((r = sshbuf_put_string(c->output, data, data_len)) != 0)
3401 fatal_fr(r, "channel %i: append datagram", c->self);
3402 } else if ((r = sshbuf_put(c->output, data, data_len)) != 0)
3403 fatal_fr(r, "channel %i: append data", c->self);
3409 channel_input_extended_data(int type, u_int32_t seq, struct ssh *ssh)
3414 Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
3417 if (channel_proxy_upstream(c, type, seq, ssh))
3419 if (c->type != SSH_CHANNEL_OPEN) {
3420 logit("channel %d: ext data for non open", c->self);
3423 if (c->flags & CHAN_EOF_RCVD) {
3424 if (ssh->compat & SSH_BUG_EXTEOF)
3425 debug("channel %d: accepting ext data after eof",
3428 ssh_packet_disconnect(ssh, "Received extended_data "
3429 "after EOF on channel %d.", c->self);
3432 if ((r = sshpkt_get_u32(ssh, &tcode)) != 0) {
3433 error_fr(r, "parse tcode");
3434 ssh_packet_disconnect(ssh, "Invalid extended_data message");
3437 c->extended_usage != CHAN_EXTENDED_WRITE ||
3438 tcode != SSH2_EXTENDED_DATA_STDERR) {
3439 logit("channel %d: bad ext data", c->self);
3442 if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
3443 (r = sshpkt_get_end(ssh)) != 0) {
3444 error_fr(r, "parse data");
3445 ssh_packet_disconnect(ssh, "Invalid extended_data message");
3448 if (data_len > c->local_window) {
3449 logit("channel %d: rcvd too much extended_data %zu, win %u",
3450 c->self, data_len, c->local_window);
3453 debug2("channel %d: rcvd ext data %zu", c->self, data_len);
3454 /* XXX sshpkt_getb? */
3455 if ((r = sshbuf_put(c->extended, data, data_len)) != 0)
3456 error_fr(r, "append");
3457 c->local_window -= data_len;
3462 channel_input_ieof(int type, u_int32_t seq, struct ssh *ssh)
3464 Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
3467 if ((r = sshpkt_get_end(ssh)) != 0) {
3468 error_fr(r, "parse data");
3469 ssh_packet_disconnect(ssh, "Invalid ieof message");
3472 if (channel_proxy_upstream(c, type, seq, ssh))
3474 chan_rcvd_ieof(ssh, c);
3476 /* XXX force input close */
3477 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
3478 debug("channel %d: FORCE input drain", c->self);
3479 c->istate = CHAN_INPUT_WAIT_DRAIN;
3480 if (sshbuf_len(c->input) == 0)
3481 chan_ibuf_empty(ssh, c);
3487 channel_input_oclose(int type, u_int32_t seq, struct ssh *ssh)
3489 Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
3492 if (channel_proxy_upstream(c, type, seq, ssh))
3494 if ((r = sshpkt_get_end(ssh)) != 0) {
3495 error_fr(r, "parse data");
3496 ssh_packet_disconnect(ssh, "Invalid oclose message");
3498 chan_rcvd_oclose(ssh, c);
3503 channel_input_open_confirmation(int type, u_int32_t seq, struct ssh *ssh)
3505 Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
3506 u_int32_t remote_window, remote_maxpacket;
3509 if (channel_proxy_upstream(c, type, seq, ssh))
3511 if (c->type != SSH_CHANNEL_OPENING)
3512 ssh_packet_disconnect(ssh, "Received open confirmation for "
3513 "non-opening channel %d.", c->self);
3515 * Record the remote channel number and mark that the channel
3518 if ((r = sshpkt_get_u32(ssh, &c->remote_id)) != 0 ||
3519 (r = sshpkt_get_u32(ssh, &remote_window)) != 0 ||
3520 (r = sshpkt_get_u32(ssh, &remote_maxpacket)) != 0 ||
3521 (r = sshpkt_get_end(ssh)) != 0) {
3522 error_fr(r, "window/maxpacket");
3523 ssh_packet_disconnect(ssh, "Invalid open confirmation message");
3526 c->have_remote_id = 1;
3527 c->remote_window = remote_window;
3528 c->remote_maxpacket = remote_maxpacket;
3529 c->type = SSH_CHANNEL_OPEN;
3530 if (c->open_confirm) {
3531 debug2_f("channel %d: callback start", c->self);
3532 c->open_confirm(ssh, c->self, 1, c->open_confirm_ctx);
3533 debug2_f("channel %d: callback done", c->self);
3535 c->lastused = monotime();
3536 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
3537 c->remote_window, c->remote_maxpacket);
3542 reason2txt(int reason)
3545 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
3546 return "administratively prohibited";
3547 case SSH2_OPEN_CONNECT_FAILED:
3548 return "connect failed";
3549 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
3550 return "unknown channel type";
3551 case SSH2_OPEN_RESOURCE_SHORTAGE:
3552 return "resource shortage";
3554 return "unknown reason";
3558 channel_input_open_failure(int type, u_int32_t seq, struct ssh *ssh)
3560 Channel *c = channel_from_packet_id(ssh, __func__, "open failure");
3565 if (channel_proxy_upstream(c, type, seq, ssh))
3567 if (c->type != SSH_CHANNEL_OPENING)
3568 ssh_packet_disconnect(ssh, "Received open failure for "
3569 "non-opening channel %d.", c->self);
3570 if ((r = sshpkt_get_u32(ssh, &reason)) != 0) {
3571 error_fr(r, "parse reason");
3572 ssh_packet_disconnect(ssh, "Invalid open failure message");
3575 if ((r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
3576 (r = sshpkt_get_string_direct(ssh, NULL, NULL)) != 0 ||
3577 (r = sshpkt_get_end(ssh)) != 0) {
3578 error_fr(r, "parse msg/lang");
3579 ssh_packet_disconnect(ssh, "Invalid open failure message");
3581 logit("channel %d: open failed: %s%s%s", c->self,
3582 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
3584 if (c->open_confirm) {
3585 debug2_f("channel %d: callback start", c->self);
3586 c->open_confirm(ssh, c->self, 0, c->open_confirm_ctx);
3587 debug2_f("channel %d: callback done", c->self);
3589 /* Schedule the channel for cleanup/deletion. */
3590 chan_mark_dead(ssh, c);
3595 channel_input_window_adjust(int type, u_int32_t seq, struct ssh *ssh)
3597 int id = channel_parse_id(ssh, __func__, "window adjust");
3603 if ((c = channel_lookup(ssh, id)) == NULL) {
3604 logit("Received window adjust for non-open channel %d.", id);
3608 if (channel_proxy_upstream(c, type, seq, ssh))
3610 if ((r = sshpkt_get_u32(ssh, &adjust)) != 0 ||
3611 (r = sshpkt_get_end(ssh)) != 0) {
3612 error_fr(r, "parse adjust");
3613 ssh_packet_disconnect(ssh, "Invalid window adjust message");
3615 debug2("channel %d: rcvd adjust %u", c->self, adjust);
3616 if ((new_rwin = c->remote_window + adjust) < c->remote_window) {
3617 fatal("channel %d: adjust %u overflows remote window %u",
3618 c->self, adjust, c->remote_window);
3620 c->remote_window = new_rwin;
3625 channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
3627 int id = channel_parse_id(ssh, __func__, "status confirm");
3629 struct channel_confirm *cc;
3631 /* Reset keepalive timeout */
3632 ssh_packet_set_alive_timeouts(ssh, 0);
3634 debug2_f("type %d id %d", type, id);
3636 if ((c = channel_lookup(ssh, id)) == NULL) {
3637 logit_f("%d: unknown", id);
3640 if (channel_proxy_upstream(c, type, seq, ssh))
3642 if (sshpkt_get_end(ssh) != 0)
3643 ssh_packet_disconnect(ssh, "Invalid status confirm message");
3644 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
3646 cc->cb(ssh, type, c, cc->ctx);
3647 TAILQ_REMOVE(&c->status_confirms, cc, entry);
3648 freezero(cc, sizeof(*cc));
3652 /* -- tcp forwarding */
3655 channel_set_af(struct ssh *ssh, int af)
3657 ssh->chanctxt->IPv4or6 = af;
3662 * Determine whether or not a port forward listens to loopback, the
3663 * specified address or wildcard. On the client, a specified bind
3664 * address will always override gateway_ports. On the server, a
3665 * gateway_ports of 1 (``yes'') will override the client's specification
3666 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
3667 * will bind to whatever address the client asked for.
3669 * Special-case listen_addrs are:
3671 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
3672 * "" (empty string), "*" -> wildcard v4/v6
3673 * "localhost" -> loopback v4/v6
3674 * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
3677 channel_fwd_bind_addr(struct ssh *ssh, const char *listen_addr, int *wildcardp,
3678 int is_client, struct ForwardOptions *fwd_opts)
3680 const char *addr = NULL;
3683 if (listen_addr == NULL) {
3684 /* No address specified: default to gateway_ports setting */
3685 if (fwd_opts->gateway_ports)
3687 } else if (fwd_opts->gateway_ports || is_client) {
3688 if (((ssh->compat & SSH_OLD_FORWARD_ADDR) &&
3689 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3690 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
3691 (!is_client && fwd_opts->gateway_ports == 1)) {
3694 * Notify client if they requested a specific listen
3695 * address and it was overridden.
3697 if (*listen_addr != '\0' &&
3698 strcmp(listen_addr, "0.0.0.0") != 0 &&
3699 strcmp(listen_addr, "*") != 0) {
3700 ssh_packet_send_debug(ssh,
3701 "Forwarding listen address "
3702 "\"%s\" overridden by server "
3703 "GatewayPorts", listen_addr);
3705 } else if (strcmp(listen_addr, "localhost") != 0 ||
3706 strcmp(listen_addr, "127.0.0.1") == 0 ||
3707 strcmp(listen_addr, "::1") == 0) {
3709 * Accept explicit localhost address when
3710 * GatewayPorts=yes. The "localhost" hostname is
3711 * deliberately skipped here so it will listen on all
3712 * available local address families.
3716 } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
3717 strcmp(listen_addr, "::1") == 0) {
3719 * If a specific IPv4/IPv6 localhost address has been
3720 * requested then accept it even if gateway_ports is in
3721 * effect. This allows the client to prefer IPv4 or IPv6.
3725 if (wildcardp != NULL)
3726 *wildcardp = wildcard;
3731 channel_setup_fwd_listener_tcpip(struct ssh *ssh, int type,
3732 struct Forward *fwd, int *allocated_listen_port,
3733 struct ForwardOptions *fwd_opts)
3736 int sock, r, success = 0, wildcard = 0, is_client;
3737 struct addrinfo hints, *ai, *aitop;
3738 const char *host, *addr;
3739 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3742 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
3744 if (is_client && fwd->connect_path != NULL) {
3745 host = fwd->connect_path;
3747 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
3748 fwd->listen_host : fwd->connect_host;
3750 error("No forward host name.");
3753 if (strlen(host) >= NI_MAXHOST) {
3754 error("Forward host name too long.");
3759 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
3760 addr = channel_fwd_bind_addr(ssh, fwd->listen_host, &wildcard,
3761 is_client, fwd_opts);
3762 debug3_f("type %d wildcard %d addr %s", type, wildcard,
3763 (addr == NULL) ? "NULL" : addr);
3766 * getaddrinfo returns a loopback address if the hostname is
3767 * set to NULL and hints.ai_flags is not AI_PASSIVE
3769 memset(&hints, 0, sizeof(hints));
3770 hints.ai_family = ssh->chanctxt->IPv4or6;
3771 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
3772 hints.ai_socktype = SOCK_STREAM;
3773 snprintf(strport, sizeof strport, "%d", fwd->listen_port);
3774 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
3776 /* This really shouldn't happen */
3777 ssh_packet_disconnect(ssh, "getaddrinfo: fatal error: %s",
3778 ssh_gai_strerror(r));
3780 error_f("getaddrinfo(%.64s): %s", addr,
3781 ssh_gai_strerror(r));
3785 if (allocated_listen_port != NULL)
3786 *allocated_listen_port = 0;
3787 for (ai = aitop; ai; ai = ai->ai_next) {
3788 switch (ai->ai_family) {
3790 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
3794 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
3801 * If allocating a port for -R forwards, then use the
3802 * same port for all address families.
3804 if (type == SSH_CHANNEL_RPORT_LISTENER &&
3805 fwd->listen_port == 0 && allocated_listen_port != NULL &&
3806 *allocated_listen_port > 0)
3807 *lport_p = htons(*allocated_listen_port);
3809 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
3810 strport, sizeof(strport),
3811 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3812 error_f("getnameinfo failed");
3815 /* Create a port to listen for the host. */
3816 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3818 /* this is no error since kernel may not support ipv6 */
3819 verbose("socket [%s]:%s: %.100s", ntop, strport,
3824 set_reuseaddr(sock);
3825 if (ai->ai_family == AF_INET6)
3826 sock_set_v6only(sock);
3828 debug("Local forwarding listening on %s port %s.",
3831 /* Bind the socket to the address. */
3832 if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
3834 * address can be in if use ipv6 address is
3838 error("bind [%s]:%s: %.100s",
3839 ntop, strport, strerror(errno));
3841 verbose("bind [%s]:%s: %.100s",
3842 ntop, strport, strerror(errno));
3847 /* Start listening for connections on the socket. */
3848 if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
3849 error("listen [%s]:%s: %.100s", ntop, strport,
3856 * fwd->listen_port == 0 requests a dynamically allocated port -
3857 * record what we got.
3859 if (type == SSH_CHANNEL_RPORT_LISTENER &&
3860 fwd->listen_port == 0 &&
3861 allocated_listen_port != NULL &&
3862 *allocated_listen_port == 0) {
3863 *allocated_listen_port = get_local_port(sock);
3864 debug("Allocated listen port %d",
3865 *allocated_listen_port);
3868 /* Allocate a channel number for the socket. */
3869 c = channel_new(ssh, "port-listener", type, sock, sock, -1,
3870 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3871 0, "port listener", 1);
3872 c->path = xstrdup(host);
3873 c->host_port = fwd->connect_port;
3874 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
3875 if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
3876 !(ssh->compat & SSH_BUG_DYNAMIC_RPORT))
3877 c->listening_port = *allocated_listen_port;
3879 c->listening_port = fwd->listen_port;
3883 error_f("cannot listen to port: %d", fwd->listen_port);
3884 freeaddrinfo(aitop);
3889 channel_setup_fwd_listener_streamlocal(struct ssh *ssh, int type,
3890 struct Forward *fwd, struct ForwardOptions *fwd_opts)
3892 struct sockaddr_un sunaddr;
3899 case SSH_CHANNEL_UNIX_LISTENER:
3900 if (fwd->connect_path != NULL) {
3901 if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
3902 error("Local connecting path too long: %s",
3906 path = fwd->connect_path;
3907 port = PORT_STREAMLOCAL;
3909 if (fwd->connect_host == NULL) {
3910 error("No forward host name.");
3913 if (strlen(fwd->connect_host) >= NI_MAXHOST) {
3914 error("Forward host name too long.");
3917 path = fwd->connect_host;
3918 port = fwd->connect_port;
3921 case SSH_CHANNEL_RUNIX_LISTENER:
3922 path = fwd->listen_path;
3923 port = PORT_STREAMLOCAL;
3926 error_f("unexpected channel type %d", type);
3930 if (fwd->listen_path == NULL) {
3931 error("No forward path name.");
3934 if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
3935 error("Local listening path too long: %s", fwd->listen_path);
3939 debug3_f("type %d path %s", type, fwd->listen_path);
3941 /* Start a Unix domain listener. */
3942 omask = umask(fwd_opts->streamlocal_bind_mask);
3943 sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
3944 fwd_opts->streamlocal_bind_unlink);
3949 debug("Local forwarding listening on path %s.", fwd->listen_path);
3951 /* Allocate a channel number for the socket. */
3952 c = channel_new(ssh, "unix-listener", type, sock, sock, -1,
3953 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3954 0, "unix listener", 1);
3955 c->path = xstrdup(path);
3956 c->host_port = port;
3957 c->listening_port = PORT_STREAMLOCAL;
3958 c->listening_addr = xstrdup(fwd->listen_path);
3963 channel_cancel_rport_listener_tcpip(struct ssh *ssh,
3964 const char *host, u_short port)
3969 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3970 Channel *c = ssh->chanctxt->channels[i];
3971 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3973 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3974 debug2_f("close channel %d", i);
3975 channel_free(ssh, c);
3984 channel_cancel_rport_listener_streamlocal(struct ssh *ssh, const char *path)
3989 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3990 Channel *c = ssh->chanctxt->channels[i];
3991 if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3993 if (c->path == NULL)
3995 if (strcmp(c->path, path) == 0) {
3996 debug2_f("close channel %d", i);
3997 channel_free(ssh, c);
4006 channel_cancel_rport_listener(struct ssh *ssh, struct Forward *fwd)
4008 if (fwd->listen_path != NULL) {
4009 return channel_cancel_rport_listener_streamlocal(ssh,
4012 return channel_cancel_rport_listener_tcpip(ssh,
4013 fwd->listen_host, fwd->listen_port);
4018 channel_cancel_lport_listener_tcpip(struct ssh *ssh,
4019 const char *lhost, u_short lport, int cport,
4020 struct ForwardOptions *fwd_opts)
4024 const char *addr = channel_fwd_bind_addr(ssh, lhost, NULL, 1, fwd_opts);
4026 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
4027 Channel *c = ssh->chanctxt->channels[i];
4028 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
4030 if (c->listening_port != lport)
4032 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
4033 /* skip dynamic forwardings */
4034 if (c->host_port == 0)
4037 if (c->host_port != cport)
4040 if ((c->listening_addr == NULL && addr != NULL) ||
4041 (c->listening_addr != NULL && addr == NULL))
4043 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
4044 debug2_f("close channel %d", i);
4045 channel_free(ssh, c);
4054 channel_cancel_lport_listener_streamlocal(struct ssh *ssh, const char *path)
4060 error_f("no path specified.");
4064 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
4065 Channel *c = ssh->chanctxt->channels[i];
4066 if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
4068 if (c->listening_addr == NULL)
4070 if (strcmp(c->listening_addr, path) == 0) {
4071 debug2_f("close channel %d", i);
4072 channel_free(ssh, c);
4081 channel_cancel_lport_listener(struct ssh *ssh,
4082 struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
4084 if (fwd->listen_path != NULL) {
4085 return channel_cancel_lport_listener_streamlocal(ssh,
4088 return channel_cancel_lport_listener_tcpip(ssh,
4089 fwd->listen_host, fwd->listen_port, cport, fwd_opts);
4093 /* protocol local port fwd, used by ssh */
4095 channel_setup_local_fwd_listener(struct ssh *ssh,
4096 struct Forward *fwd, struct ForwardOptions *fwd_opts)
4098 if (fwd->listen_path != NULL) {
4099 return channel_setup_fwd_listener_streamlocal(ssh,
4100 SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
4102 return channel_setup_fwd_listener_tcpip(ssh,
4103 SSH_CHANNEL_PORT_LISTENER, fwd, NULL, fwd_opts);
4107 /* Matches a remote forwarding permission against a requested forwarding */
4109 remote_open_match(struct permission *allowed_open, struct Forward *fwd)
4114 /* XXX add ACLs for streamlocal */
4115 if (fwd->listen_path != NULL)
4118 if (fwd->listen_host == NULL || allowed_open->listen_host == NULL)
4121 if (allowed_open->listen_port != FWD_PERMIT_ANY_PORT &&
4122 allowed_open->listen_port != fwd->listen_port)
4125 /* Match hostnames case-insensitively */
4126 lhost = xstrdup(fwd->listen_host);
4128 ret = match_pattern(lhost, allowed_open->listen_host);
4134 /* Checks whether a requested remote forwarding is permitted */
4136 check_rfwd_permission(struct ssh *ssh, struct Forward *fwd)
4138 struct ssh_channels *sc = ssh->chanctxt;
4139 struct permission_set *pset = &sc->remote_perms;
4140 u_int i, permit, permit_adm = 1;
4141 struct permission *perm;
4143 /* XXX apply GatewayPorts override before checking? */
4145 permit = pset->all_permitted;
4147 for (i = 0; i < pset->num_permitted_user; i++) {
4148 perm = &pset->permitted_user[i];
4149 if (remote_open_match(perm, fwd)) {
4156 if (pset->num_permitted_admin > 0) {
4158 for (i = 0; i < pset->num_permitted_admin; i++) {
4159 perm = &pset->permitted_admin[i];
4160 if (remote_open_match(perm, fwd)) {
4167 return permit && permit_adm;
4170 /* protocol v2 remote port fwd, used by sshd */
4172 channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
4173 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
4175 if (!check_rfwd_permission(ssh, fwd)) {
4176 ssh_packet_send_debug(ssh, "port forwarding refused");
4177 if (fwd->listen_path != NULL)
4178 /* XXX always allowed, see remote_open_match() */
4179 logit("Received request from %.100s port %d to "
4180 "remote forward to path \"%.100s\", "
4181 "but the request was denied.",
4182 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
4184 else if(fwd->listen_host != NULL)
4185 logit("Received request from %.100s port %d to "
4186 "remote forward to host %.100s port %d, "
4187 "but the request was denied.",
4188 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
4189 fwd->listen_host, fwd->listen_port );
4191 logit("Received request from %.100s port %d to remote "
4192 "forward, but the request was denied.",
4193 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
4196 if (fwd->listen_path != NULL) {
4197 return channel_setup_fwd_listener_streamlocal(ssh,
4198 SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
4200 return channel_setup_fwd_listener_tcpip(ssh,
4201 SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
4207 * Translate the requested rfwd listen host to something usable for
4211 channel_rfwd_bind_host(const char *listen_host)
4213 if (listen_host == NULL) {
4215 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
4222 * Initiate forwarding of connections to port "port" on remote host through
4223 * the secure channel to host:port from local side.
4224 * Returns handle (index) for updating the dynamic listen port with
4225 * channel_update_permission().
4228 channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
4230 int r, success = 0, idx = -1;
4231 const char *host_to_connect, *listen_host, *listen_path;
4232 int port_to_connect, listen_port;
4234 /* Send the forward request to the remote side. */
4235 if (fwd->listen_path != NULL) {
4236 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
4237 (r = sshpkt_put_cstring(ssh,
4238 "streamlocal-forward@openssh.com")) != 0 ||
4239 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
4240 (r = sshpkt_put_cstring(ssh, fwd->listen_path)) != 0 ||
4241 (r = sshpkt_send(ssh)) != 0 ||
4242 (r = ssh_packet_write_wait(ssh)) != 0)
4243 fatal_fr(r, "request streamlocal");
4245 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
4246 (r = sshpkt_put_cstring(ssh, "tcpip-forward")) != 0 ||
4247 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
4248 (r = sshpkt_put_cstring(ssh,
4249 channel_rfwd_bind_host(fwd->listen_host))) != 0 ||
4250 (r = sshpkt_put_u32(ssh, fwd->listen_port)) != 0 ||
4251 (r = sshpkt_send(ssh)) != 0 ||
4252 (r = ssh_packet_write_wait(ssh)) != 0)
4253 fatal_fr(r, "request tcpip-forward");
4255 /* Assume that server accepts the request */
4258 /* Record that connection to this host/port is permitted. */
4259 host_to_connect = listen_host = listen_path = NULL;
4260 port_to_connect = listen_port = 0;
4261 if (fwd->connect_path != NULL) {
4262 host_to_connect = fwd->connect_path;
4263 port_to_connect = PORT_STREAMLOCAL;
4265 host_to_connect = fwd->connect_host;
4266 port_to_connect = fwd->connect_port;
4268 if (fwd->listen_path != NULL) {
4269 listen_path = fwd->listen_path;
4270 listen_port = PORT_STREAMLOCAL;
4272 listen_host = fwd->listen_host;
4273 listen_port = fwd->listen_port;
4275 idx = permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL,
4276 host_to_connect, port_to_connect,
4277 listen_host, listen_path, listen_port, NULL);
4283 open_match(struct permission *allowed_open, const char *requestedhost,
4286 if (allowed_open->host_to_connect == NULL)
4288 if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
4289 allowed_open->port_to_connect != requestedport)
4291 if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
4292 strcmp(allowed_open->host_to_connect, requestedhost) != 0)
4298 * Note that in the listen host/port case
4299 * we don't support FWD_PERMIT_ANY_PORT and
4300 * need to translate between the configured-host (listen_host)
4301 * and what we've sent to the remote server (channel_rfwd_bind_host)
4304 open_listen_match_tcpip(struct permission *allowed_open,
4305 const char *requestedhost, u_short requestedport, int translate)
4307 const char *allowed_host;
4309 if (allowed_open->host_to_connect == NULL)
4311 if (allowed_open->listen_port != requestedport)
4313 if (!translate && allowed_open->listen_host == NULL &&
4314 requestedhost == NULL)
4316 allowed_host = translate ?
4317 channel_rfwd_bind_host(allowed_open->listen_host) :
4318 allowed_open->listen_host;
4319 if (allowed_host == NULL || requestedhost == NULL ||
4320 strcmp(allowed_host, requestedhost) != 0)
4326 open_listen_match_streamlocal(struct permission *allowed_open,
4327 const char *requestedpath)
4329 if (allowed_open->host_to_connect == NULL)
4331 if (allowed_open->listen_port != PORT_STREAMLOCAL)
4333 if (allowed_open->listen_path == NULL ||
4334 strcmp(allowed_open->listen_path, requestedpath) != 0)
4340 * Request cancellation of remote forwarding of connection host:port from
4344 channel_request_rforward_cancel_tcpip(struct ssh *ssh,
4345 const char *host, u_short port)
4347 struct ssh_channels *sc = ssh->chanctxt;
4348 struct permission_set *pset = &sc->local_perms;
4351 struct permission *perm = NULL;
4353 for (i = 0; i < pset->num_permitted_user; i++) {
4354 perm = &pset->permitted_user[i];
4355 if (open_listen_match_tcpip(perm, host, port, 0))
4360 debug_f("requested forward not found");
4363 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
4364 (r = sshpkt_put_cstring(ssh, "cancel-tcpip-forward")) != 0 ||
4365 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
4366 (r = sshpkt_put_cstring(ssh, channel_rfwd_bind_host(host))) != 0 ||
4367 (r = sshpkt_put_u32(ssh, port)) != 0 ||
4368 (r = sshpkt_send(ssh)) != 0)
4369 fatal_fr(r, "send cancel");
4371 fwd_perm_clear(perm); /* unregister */
4377 * Request cancellation of remote forwarding of Unix domain socket
4378 * path from local side.
4381 channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
4383 struct ssh_channels *sc = ssh->chanctxt;
4384 struct permission_set *pset = &sc->local_perms;
4387 struct permission *perm = NULL;
4389 for (i = 0; i < pset->num_permitted_user; i++) {
4390 perm = &pset->permitted_user[i];
4391 if (open_listen_match_streamlocal(perm, path))
4396 debug_f("requested forward not found");
4399 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
4400 (r = sshpkt_put_cstring(ssh,
4401 "cancel-streamlocal-forward@openssh.com")) != 0 ||
4402 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
4403 (r = sshpkt_put_cstring(ssh, path)) != 0 ||
4404 (r = sshpkt_send(ssh)) != 0)
4405 fatal_fr(r, "send cancel");
4407 fwd_perm_clear(perm); /* unregister */
4413 * Request cancellation of remote forwarding of a connection from local side.
4416 channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
4418 if (fwd->listen_path != NULL) {
4419 return channel_request_rforward_cancel_streamlocal(ssh,
4422 return channel_request_rforward_cancel_tcpip(ssh,
4424 fwd->listen_port ? fwd->listen_port : fwd->allocated_port);
4429 * Permits opening to any host/port if permitted_user[] is empty. This is
4430 * usually called by the server, because the user could connect to any port
4431 * anyway, and the server has no way to know but to trust the client anyway.
4434 channel_permit_all(struct ssh *ssh, int where)
4436 struct permission_set *pset = permission_set_get(ssh, where);
4438 if (pset->num_permitted_user == 0)
4439 pset->all_permitted = 1;
4443 * Permit the specified host/port for forwarding.
4446 channel_add_permission(struct ssh *ssh, int who, int where,
4447 char *host, int port)
4449 int local = where == FORWARD_LOCAL;
4450 struct permission_set *pset = permission_set_get(ssh, where);
4452 debug("allow %s forwarding to host %s port %d",
4453 fwd_ident(who, where), host, port);
4455 * Remote forwards set listen_host/port, local forwards set
4456 * host/port_to_connect.
4458 permission_set_add(ssh, who, where,
4459 local ? host : 0, local ? port : 0,
4460 local ? NULL : host, NULL, local ? 0 : port, NULL);
4461 pset->all_permitted = 0;
4465 * Administratively disable forwarding.
4468 channel_disable_admin(struct ssh *ssh, int where)
4470 channel_clear_permission(ssh, FORWARD_ADM, where);
4471 permission_set_add(ssh, FORWARD_ADM, where,
4472 NULL, 0, NULL, NULL, 0, NULL);
4476 * Clear a list of permitted opens.
4479 channel_clear_permission(struct ssh *ssh, int who, int where)
4481 struct permission **permp;
4484 permission_set_get_array(ssh, who, where, &permp, &npermp);
4485 *permp = xrecallocarray(*permp, *npermp, 0, sizeof(**permp));
4490 * Update the listen port for a dynamic remote forward, after
4491 * the actual 'newport' has been allocated. If 'newport' < 0 is
4492 * passed then they entry will be invalidated.
4495 channel_update_permission(struct ssh *ssh, int idx, int newport)
4497 struct permission_set *pset = &ssh->chanctxt->local_perms;
4499 if (idx < 0 || (u_int)idx >= pset->num_permitted_user) {
4500 debug_f("index out of range: %d num_permitted_user %d",
4501 idx, pset->num_permitted_user);
4504 debug("%s allowed port %d for forwarding to host %s port %d",
4505 newport > 0 ? "Updating" : "Removing",
4507 pset->permitted_user[idx].host_to_connect,
4508 pset->permitted_user[idx].port_to_connect);
4510 fwd_perm_clear(&pset->permitted_user[idx]);
4512 pset->permitted_user[idx].listen_port =
4513 (ssh->compat & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
4517 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
4519 permitopen_port(const char *p)
4523 if (strcmp(p, "*") == 0)
4524 return FWD_PERMIT_ANY_PORT;
4525 if ((port = a2port(p)) > 0)
4530 /* Try to start non-blocking connect to next host in cctx list */
4532 connect_next(struct channel_connect *cctx)
4534 int sock, saved_errno;
4535 struct sockaddr_un *sunaddr;
4536 char ntop[NI_MAXHOST];
4537 char strport[MAXIMUM(NI_MAXSERV, sizeof(sunaddr->sun_path))];
4539 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
4540 switch (cctx->ai->ai_family) {
4542 /* unix:pathname instead of host:port */
4543 sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
4544 strlcpy(ntop, "unix", sizeof(ntop));
4545 strlcpy(strport, sunaddr->sun_path, sizeof(strport));
4549 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
4550 ntop, sizeof(ntop), strport, sizeof(strport),
4551 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
4552 error_f("getnameinfo failed");
4559 debug_f("start for host %.100s ([%.100s]:%s)",
4560 cctx->host, ntop, strport);
4561 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
4562 cctx->ai->ai_protocol)) == -1) {
4563 if (cctx->ai->ai_next == NULL)
4564 error("socket: %.100s", strerror(errno));
4566 verbose("socket: %.100s", strerror(errno));
4569 if (set_nonblock(sock) == -1)
4570 fatal_f("set_nonblock(%d)", sock);
4571 if (connect(sock, cctx->ai->ai_addr,
4572 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
4573 debug_f("host %.100s ([%.100s]:%s): %.100s",
4574 cctx->host, ntop, strport, strerror(errno));
4575 saved_errno = errno;
4577 errno = saved_errno;
4578 continue; /* fail -- try next */
4580 if (cctx->ai->ai_family != AF_UNIX)
4582 debug_f("connect host %.100s ([%.100s]:%s) in progress, fd=%d",
4583 cctx->host, ntop, strport, sock);
4584 cctx->ai = cctx->ai->ai_next;
4591 channel_connect_ctx_free(struct channel_connect *cctx)
4595 if (cctx->aitop->ai_family == AF_UNIX)
4598 freeaddrinfo(cctx->aitop);
4600 memset(cctx, 0, sizeof(*cctx));
4604 * Return connecting socket to remote host:port or local socket path,
4605 * passing back the failure reason if appropriate.
4608 connect_to_helper(struct ssh *ssh, const char *name, int port, int socktype,
4609 char *ctype, char *rname, struct channel_connect *cctx,
4610 int *reason, const char **errmsg)
4612 struct addrinfo hints;
4615 char strport[NI_MAXSERV];
4617 if (port == PORT_STREAMLOCAL) {
4618 struct sockaddr_un *sunaddr;
4619 struct addrinfo *ai;
4621 if (strlen(name) > sizeof(sunaddr->sun_path)) {
4622 error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
4627 * Fake up a struct addrinfo for AF_UNIX connections.
4628 * channel_connect_ctx_free() must check ai_family
4629 * and use free() not freeaddirinfo() for AF_UNIX.
4631 ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
4632 memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
4633 ai->ai_addr = (struct sockaddr *)(ai + 1);
4634 ai->ai_addrlen = sizeof(*sunaddr);
4635 ai->ai_family = AF_UNIX;
4636 ai->ai_socktype = socktype;
4637 ai->ai_protocol = PF_UNSPEC;
4638 sunaddr = (struct sockaddr_un *)ai->ai_addr;
4639 sunaddr->sun_family = AF_UNIX;
4640 strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
4643 memset(&hints, 0, sizeof(hints));
4644 hints.ai_family = ssh->chanctxt->IPv4or6;
4645 hints.ai_socktype = socktype;
4646 snprintf(strport, sizeof strport, "%d", port);
4647 if ((gaierr = getaddrinfo(name, strport, &hints, &cctx->aitop))
4650 *errmsg = ssh_gai_strerror(gaierr);
4652 *reason = SSH2_OPEN_CONNECT_FAILED;
4653 error("connect_to %.100s: unknown host (%s)", name,
4654 ssh_gai_strerror(gaierr));
4659 cctx->host = xstrdup(name);
4661 cctx->ai = cctx->aitop;
4663 if ((sock = connect_next(cctx)) == -1) {
4664 error("connect to %.100s port %d failed: %s",
4665 name, port, strerror(errno));
4672 /* Return CONNECTING channel to remote host:port or local socket path */
4674 connect_to(struct ssh *ssh, const char *host, int port,
4675 char *ctype, char *rname)
4677 struct channel_connect cctx;
4681 memset(&cctx, 0, sizeof(cctx));
4682 sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
4685 channel_connect_ctx_free(&cctx);
4688 c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
4689 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4690 c->host_port = port;
4691 c->path = xstrdup(host);
4692 c->connect_ctx = cctx;
4698 * returns either the newly connected channel or the downstream channel
4699 * that needs to deal with this connection.
4702 channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
4703 u_short listen_port, char *ctype, char *rname)
4705 struct ssh_channels *sc = ssh->chanctxt;
4706 struct permission_set *pset = &sc->local_perms;
4708 struct permission *perm;
4710 for (i = 0; i < pset->num_permitted_user; i++) {
4711 perm = &pset->permitted_user[i];
4712 if (open_listen_match_tcpip(perm,
4713 listen_host, listen_port, 1)) {
4714 if (perm->downstream)
4715 return perm->downstream;
4716 if (perm->port_to_connect == 0)
4717 return rdynamic_connect_prepare(ssh,
4719 return connect_to(ssh,
4720 perm->host_to_connect, perm->port_to_connect,
4724 error("WARNING: Server requests forwarding for unknown listen_port %d",
4730 channel_connect_by_listen_path(struct ssh *ssh, const char *path,
4731 char *ctype, char *rname)
4733 struct ssh_channels *sc = ssh->chanctxt;
4734 struct permission_set *pset = &sc->local_perms;
4736 struct permission *perm;
4738 for (i = 0; i < pset->num_permitted_user; i++) {
4739 perm = &pset->permitted_user[i];
4740 if (open_listen_match_streamlocal(perm, path)) {
4741 return connect_to(ssh,
4742 perm->host_to_connect, perm->port_to_connect,
4746 error("WARNING: Server requests forwarding for unknown path %.100s",
4751 /* Check if connecting to that port is permitted and connect. */
4753 channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
4754 char *ctype, char *rname, int *reason, const char **errmsg)
4756 struct ssh_channels *sc = ssh->chanctxt;
4757 struct permission_set *pset = &sc->local_perms;
4758 struct channel_connect cctx;
4760 u_int i, permit, permit_adm = 1;
4762 struct permission *perm;
4764 permit = pset->all_permitted;
4766 for (i = 0; i < pset->num_permitted_user; i++) {
4767 perm = &pset->permitted_user[i];
4768 if (open_match(perm, host, port)) {
4775 if (pset->num_permitted_admin > 0) {
4777 for (i = 0; i < pset->num_permitted_admin; i++) {
4778 perm = &pset->permitted_admin[i];
4779 if (open_match(perm, host, port)) {
4786 if (!permit || !permit_adm) {
4787 logit("Received request from %.100s port %d to connect to "
4788 "host %.100s port %d, but the request was denied.",
4789 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), host, port);
4791 *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
4795 memset(&cctx, 0, sizeof(cctx));
4796 sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
4797 &cctx, reason, errmsg);
4799 channel_connect_ctx_free(&cctx);
4803 c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
4804 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4805 c->host_port = port;
4806 c->path = xstrdup(host);
4807 c->connect_ctx = cctx;
4812 /* Check if connecting to that path is permitted and connect. */
4814 channel_connect_to_path(struct ssh *ssh, const char *path,
4815 char *ctype, char *rname)
4817 struct ssh_channels *sc = ssh->chanctxt;
4818 struct permission_set *pset = &sc->local_perms;
4819 u_int i, permit, permit_adm = 1;
4820 struct permission *perm;
4822 permit = pset->all_permitted;
4824 for (i = 0; i < pset->num_permitted_user; i++) {
4825 perm = &pset->permitted_user[i];
4826 if (open_match(perm, path, PORT_STREAMLOCAL)) {
4833 if (pset->num_permitted_admin > 0) {
4835 for (i = 0; i < pset->num_permitted_admin; i++) {
4836 perm = &pset->permitted_admin[i];
4837 if (open_match(perm, path, PORT_STREAMLOCAL)) {
4844 if (!permit || !permit_adm) {
4845 logit("Received request to connect to path %.100s, "
4846 "but the request was denied.", path);
4849 return connect_to(ssh, path, PORT_STREAMLOCAL, ctype, rname);
4853 channel_send_window_changes(struct ssh *ssh)
4855 struct ssh_channels *sc = ssh->chanctxt;
4860 for (i = 0; i < sc->channels_alloc; i++) {
4861 if (sc->channels[i] == NULL || !sc->channels[i]->client_tty ||
4862 sc->channels[i]->type != SSH_CHANNEL_OPEN)
4864 if (ioctl(sc->channels[i]->rfd, TIOCGWINSZ, &ws) == -1)
4866 channel_request_start(ssh, i, "window-change", 0);
4867 if ((r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
4868 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
4869 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
4870 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0 ||
4871 (r = sshpkt_send(ssh)) != 0)
4872 fatal_fr(r, "channel %u; send window-change", i);
4876 /* Return RDYNAMIC_OPEN channel: channel allows SOCKS, but is not connected */
4878 rdynamic_connect_prepare(struct ssh *ssh, char *ctype, char *rname)
4883 c = channel_new(ssh, ctype, SSH_CHANNEL_RDYNAMIC_OPEN, -1, -1, -1,
4884 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4889 * We need to open the channel before we have a FD,
4890 * so that we can get SOCKS header from peer.
4892 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
4893 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
4894 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
4895 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
4896 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0)
4897 fatal_fr(r, "channel %i; confirm", c->self);
4901 /* Return CONNECTING socket to remote host:port or local socket path */
4903 rdynamic_connect_finish(struct ssh *ssh, Channel *c)
4905 struct ssh_channels *sc = ssh->chanctxt;
4906 struct permission_set *pset = &sc->local_perms;
4907 struct permission *perm;
4908 struct channel_connect cctx;
4909 u_int i, permit_adm = 1;
4912 if (pset->num_permitted_admin > 0) {
4914 for (i = 0; i < pset->num_permitted_admin; i++) {
4915 perm = &pset->permitted_admin[i];
4916 if (open_match(perm, c->path, c->host_port)) {
4923 debug_f("requested forward not permitted");
4927 memset(&cctx, 0, sizeof(cctx));
4928 sock = connect_to_helper(ssh, c->path, c->host_port, SOCK_STREAM, NULL,
4929 NULL, &cctx, NULL, NULL);
4931 channel_connect_ctx_free(&cctx);
4933 /* similar to SSH_CHANNEL_CONNECTING but we've already sent the open */
4934 c->type = SSH_CHANNEL_RDYNAMIC_FINISH;
4935 c->connect_ctx = cctx;
4936 channel_register_fds(ssh, c, sock, sock, -1, 0, 1, 0);
4941 /* -- X11 forwarding */
4944 * Creates an internet domain socket for listening for X11 connections.
4945 * Returns 0 and a suitable display number for the DISPLAY variable
4946 * stored in display_numberp , or -1 if an error occurs.
4949 x11_create_display_inet(struct ssh *ssh, int x11_display_offset,
4950 int x11_use_localhost, int single_connection,
4951 u_int *display_numberp, int **chanids)
4954 int display_number, sock;
4956 struct addrinfo hints, *ai, *aitop;
4957 char strport[NI_MAXSERV];
4958 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
4960 if (chanids == NULL)
4963 for (display_number = x11_display_offset;
4964 display_number < MAX_DISPLAYS;
4966 port = 6000 + display_number;
4967 memset(&hints, 0, sizeof(hints));
4968 hints.ai_family = ssh->chanctxt->IPv4or6;
4969 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
4970 hints.ai_socktype = SOCK_STREAM;
4971 snprintf(strport, sizeof strport, "%d", port);
4972 if ((gaierr = getaddrinfo(NULL, strport,
4973 &hints, &aitop)) != 0) {
4974 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
4977 for (ai = aitop; ai; ai = ai->ai_next) {
4978 if (ai->ai_family != AF_INET &&
4979 ai->ai_family != AF_INET6)
4981 sock = socket(ai->ai_family, ai->ai_socktype,
4984 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
4986 && (errno != EPFNOSUPPORT)
4989 error("socket: %.100s", strerror(errno));
4990 freeaddrinfo(aitop);
4993 debug("x11_create_display_inet: Socket family %d not supported",
4998 if (ai->ai_family == AF_INET6)
4999 sock_set_v6only(sock);
5000 if (x11_use_localhost)
5001 set_reuseaddr(sock);
5002 if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
5003 debug2_f("bind port %d: %.100s", port,
5006 for (n = 0; n < num_socks; n++)
5011 socks[num_socks++] = sock;
5012 if (num_socks == NUM_SOCKS)
5015 freeaddrinfo(aitop);
5019 if (display_number >= MAX_DISPLAYS) {
5020 error("Failed to allocate internet-domain X11 display socket.");
5023 /* Start listening for connections on the socket. */
5024 for (n = 0; n < num_socks; n++) {
5026 if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
5027 error("listen: %.100s", strerror(errno));
5033 /* Allocate a channel for each socket. */
5034 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
5035 for (n = 0; n < num_socks; n++) {
5037 nc = channel_new(ssh, "x11-listener",
5038 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
5039 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
5040 0, "X11 inet listener", 1);
5041 nc->single_connection = single_connection;
5042 (*chanids)[n] = nc->self;
5046 /* Return the display number for the DISPLAY environment variable. */
5047 *display_numberp = display_number;
5052 connect_local_xsocket_path(const char *pathname)
5055 struct sockaddr_un addr;
5057 sock = socket(AF_UNIX, SOCK_STREAM, 0);
5059 error("socket: %.100s", strerror(errno));
5062 memset(&addr, 0, sizeof(addr));
5063 addr.sun_family = AF_UNIX;
5064 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
5065 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
5068 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
5073 connect_local_xsocket(u_int dnr)
5076 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
5077 return connect_local_xsocket_path(buf);
5082 is_path_to_xsocket(const char *display, char *path, size_t pathlen)
5086 if (strlcpy(path, display, pathlen) >= pathlen) {
5087 error("%s: display path too long", __func__);
5090 if (display[0] != '/')
5092 if (stat(path, &sbuf) == 0) {
5095 char *dot = strrchr(path, '.');
5098 if (stat(path, &sbuf) == 0) {
5108 x11_connect_display(struct ssh *ssh)
5110 u_int display_number;
5111 const char *display;
5112 char buf[1024], *cp;
5113 struct addrinfo hints, *ai, *aitop;
5114 char strport[NI_MAXSERV];
5115 int gaierr, sock = 0;
5117 /* Try to open a socket for the local X server. */
5118 display = getenv("DISPLAY");
5120 error("DISPLAY not set.");
5124 * Now we decode the value of the DISPLAY variable and make a
5125 * connection to the real X server.
5129 /* Check if display is a path to a socket (as set by launchd). */
5131 char path[PATH_MAX];
5133 if (is_path_to_xsocket(display, path, sizeof(path))) {
5134 debug("x11_connect_display: $DISPLAY is launchd");
5136 /* Create a socket. */
5137 sock = connect_local_xsocket_path(path);
5141 /* OK, we now have a connection to the display. */
5147 * Check if it is a unix domain socket. Unix domain displays are in
5148 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
5150 if (strncmp(display, "unix:", 5) == 0 ||
5151 display[0] == ':') {
5152 /* Connect to the unix domain socket. */
5153 if (sscanf(strrchr(display, ':') + 1, "%u",
5154 &display_number) != 1) {
5155 error("Could not parse display number from DISPLAY: "
5159 /* Create a socket. */
5160 sock = connect_local_xsocket(display_number);
5164 /* OK, we now have a connection to the display. */
5168 * Connect to an inet socket. The DISPLAY value is supposedly
5169 * hostname:d[.s], where hostname may also be numeric IP address.
5171 strlcpy(buf, display, sizeof(buf));
5172 cp = strchr(buf, ':');
5174 error("Could not find ':' in DISPLAY: %.100s", display);
5179 * buf now contains the host name. But first we parse the
5182 if (sscanf(cp + 1, "%u", &display_number) != 1) {
5183 error("Could not parse display number from DISPLAY: %.100s",
5188 /* Look up the host address */
5189 memset(&hints, 0, sizeof(hints));
5190 hints.ai_family = ssh->chanctxt->IPv4or6;
5191 hints.ai_socktype = SOCK_STREAM;
5192 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
5193 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
5194 error("%.100s: unknown host. (%s)", buf,
5195 ssh_gai_strerror(gaierr));
5198 for (ai = aitop; ai; ai = ai->ai_next) {
5199 /* Create a socket. */
5200 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
5202 debug2("socket: %.100s", strerror(errno));
5205 /* Connect it to the display. */
5206 if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
5207 debug2("connect %.100s port %u: %.100s", buf,
5208 6000 + display_number, strerror(errno));
5215 freeaddrinfo(aitop);
5217 error("connect %.100s port %u: %.100s", buf,
5218 6000 + display_number, strerror(errno));
5226 * Requests forwarding of X11 connections, generates fake authentication
5227 * data, and enables authentication spoofing.
5228 * This should be called in the client only.
5231 x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id,
5232 const char *disp, const char *proto, const char *data, int want_reply)
5234 struct ssh_channels *sc = ssh->chanctxt;
5235 u_int data_len = (u_int) strlen(data) / 2;
5239 int r, screen_number;
5241 if (sc->x11_saved_display == NULL)
5242 sc->x11_saved_display = xstrdup(disp);
5243 else if (strcmp(disp, sc->x11_saved_display) != 0) {
5244 error("x11_request_forwarding_with_spoofing: different "
5245 "$DISPLAY already forwarded");
5249 cp = strchr(disp, ':');
5251 cp = strchr(cp, '.');
5253 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
5257 if (sc->x11_saved_proto == NULL) {
5258 /* Save protocol name. */
5259 sc->x11_saved_proto = xstrdup(proto);
5261 /* Extract real authentication data. */
5262 sc->x11_saved_data = xmalloc(data_len);
5263 for (i = 0; i < data_len; i++) {
5264 if (sscanf(data + 2 * i, "%2x", &value) != 1) {
5265 fatal("x11_request_forwarding: bad "
5266 "authentication data: %.100s", data);
5268 sc->x11_saved_data[i] = value;
5270 sc->x11_saved_data_len = data_len;
5272 /* Generate fake data of the same length. */
5273 sc->x11_fake_data = xmalloc(data_len);
5274 arc4random_buf(sc->x11_fake_data, data_len);
5275 sc->x11_fake_data_len = data_len;
5278 /* Convert the fake data into hex. */
5279 new_data = tohex(sc->x11_fake_data, data_len);
5281 /* Send the request packet. */
5282 channel_request_start(ssh, client_session_id, "x11-req", want_reply);
5283 if ((r = sshpkt_put_u8(ssh, 0)) != 0 || /* bool: single connection */
5284 (r = sshpkt_put_cstring(ssh, proto)) != 0 ||
5285 (r = sshpkt_put_cstring(ssh, new_data)) != 0 ||
5286 (r = sshpkt_put_u32(ssh, screen_number)) != 0 ||
5287 (r = sshpkt_send(ssh)) != 0 ||
5288 (r = ssh_packet_write_wait(ssh)) != 0)
5289 fatal_fr(r, "send x11-req");