1 /* $OpenBSD: channels.c,v 1.389 2019/01/19 21:37:13 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>
70 #include "openbsd-compat/sys-queue.h"
84 #include "pathnames.h"
87 /* -- agent forwarding */
90 /* -- tcp forwarding */
91 /* special-case port number meaning allow any port */
92 #define FWD_PERMIT_ANY_PORT 0
94 /* special-case wildcard meaning allow any host */
95 #define FWD_PERMIT_ANY_HOST "*"
97 /* -- X11 forwarding */
98 /* Maximum number of fake X11 displays to try. */
99 #define MAX_DISPLAYS 1000
101 /* Per-channel callback for pre/post select() actions */
102 typedef void chan_fn(struct ssh *, Channel *c,
103 fd_set *readset, fd_set *writeset);
106 * Data structure for storing which hosts are permitted for forward requests.
107 * The local sides of any remote forwards are stored in this array to prevent
108 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
109 * network (which might be behind a firewall).
111 /* XXX: streamlocal wants a path instead of host:port */
112 /* Overload host_to_connect; we could just make this match Forward */
113 /* XXX - can we use listen_host instead of listen_path? */
115 char *host_to_connect; /* Connect to 'host'. */
116 int port_to_connect; /* Connect to 'port'. */
117 char *listen_host; /* Remote side should listen address. */
118 char *listen_path; /* Remote side should listen path. */
119 int listen_port; /* Remote side should listen port. */
120 Channel *downstream; /* Downstream mux*/
124 * Stores the forwarding permission state for a single direction (local or
127 struct permission_set {
129 * List of all local permitted host/port pairs to allow for the
132 u_int num_permitted_user;
133 struct permission *permitted_user;
136 * List of all permitted host/port pairs to allow for the admin.
138 u_int num_permitted_admin;
139 struct permission *permitted_admin;
142 * If this is true, all opens/listens are permitted. This is the
143 * case on the server on which we have to trust the client anyway,
144 * and the user could do anything after logging in.
149 /* Master structure for channels state */
150 struct ssh_channels {
152 * Pointer to an array containing all allocated channels. The array
153 * is dynamically extended as needed.
158 * Size of the channel array. All slots of the array must always be
159 * initialized (at least the type field); unused slots set to NULL
161 u_int channels_alloc;
164 * Maximum file descriptor value used in any of the channels. This is
165 * updated in channel_new.
170 * 'channel_pre*' are called just before select() to add any bits
171 * relevant to channels in the select bitmasks.
173 * 'channel_post*': perform any appropriate operations for
174 * channels which have events pending.
176 chan_fn **channel_pre;
177 chan_fn **channel_post;
179 /* -- tcp forwarding */
180 struct permission_set local_perms;
181 struct permission_set remote_perms;
183 /* -- X11 forwarding */
185 /* Saved X11 local (client) display. */
186 char *x11_saved_display;
188 /* Saved X11 authentication protocol name. */
189 char *x11_saved_proto;
191 /* Saved X11 authentication data. This is the real data. */
192 char *x11_saved_data;
193 u_int x11_saved_data_len;
195 /* Deadline after which all X11 connections are refused */
196 u_int x11_refuse_time;
199 * Fake X11 authentication data. This is what the server will be
200 * sending us; we should replace any occurrences of this by the
203 u_char *x11_fake_data;
204 u_int x11_fake_data_len;
206 /* AF_UNSPEC or AF_INET or AF_INET6 */
211 static void port_open_helper(struct ssh *ssh, Channel *c, char *rtype);
212 static const char *channel_rfwd_bind_host(const char *listen_host);
214 /* non-blocking connect helpers */
215 static int connect_next(struct channel_connect *);
216 static void channel_connect_ctx_free(struct channel_connect *);
217 static Channel *rdynamic_connect_prepare(struct ssh *, char *, char *);
218 static int rdynamic_connect_finish(struct ssh *, Channel *);
221 static void channel_handler_init(struct ssh_channels *sc);
223 /* -- channel core */
226 channel_init_channels(struct ssh *ssh)
228 struct ssh_channels *sc;
230 if ((sc = calloc(1, sizeof(*sc))) == NULL)
231 fatal("%s: allocation failed", __func__);
232 sc->channels_alloc = 10;
233 sc->channels = xcalloc(sc->channels_alloc, sizeof(*sc->channels));
234 sc->IPv4or6 = AF_UNSPEC;
235 channel_handler_init(sc);
241 channel_by_id(struct ssh *ssh, int id)
245 if (id < 0 || (u_int)id >= ssh->chanctxt->channels_alloc) {
246 logit("%s: %d: bad id", __func__, id);
249 c = ssh->chanctxt->channels[id];
251 logit("%s: %d: bad id: channel free", __func__, id);
258 channel_by_remote_id(struct ssh *ssh, u_int remote_id)
263 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
264 c = ssh->chanctxt->channels[i];
265 if (c != NULL && c->have_remote_id && c->remote_id == remote_id)
272 * Returns the channel if it is allowed to receive protocol messages.
273 * Private channels, like listening sockets, may not receive messages.
276 channel_lookup(struct ssh *ssh, int id)
280 if ((c = channel_by_id(ssh, id)) == NULL)
284 case SSH_CHANNEL_X11_OPEN:
285 case SSH_CHANNEL_LARVAL:
286 case SSH_CHANNEL_CONNECTING:
287 case SSH_CHANNEL_DYNAMIC:
288 case SSH_CHANNEL_RDYNAMIC_OPEN:
289 case SSH_CHANNEL_RDYNAMIC_FINISH:
290 case SSH_CHANNEL_OPENING:
291 case SSH_CHANNEL_OPEN:
292 case SSH_CHANNEL_ABANDONED:
293 case SSH_CHANNEL_MUX_PROXY:
296 logit("Non-public channel %d, type %d.", id, c->type);
301 * Register filedescriptors for a channel, used when allocating a channel or
302 * when the channel consumer/producer is ready, e.g. shell exec'd
305 channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
306 int extusage, int nonblock, int is_tty)
308 struct ssh_channels *sc = ssh->chanctxt;
310 /* Update the maximum file descriptor value. */
311 sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, rfd);
312 sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, wfd);
313 sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, efd);
316 fcntl(rfd, F_SETFD, FD_CLOEXEC);
317 if (wfd != -1 && wfd != rfd)
318 fcntl(wfd, F_SETFD, FD_CLOEXEC);
319 if (efd != -1 && efd != rfd && efd != wfd)
320 fcntl(efd, F_SETFD, FD_CLOEXEC);
324 c->sock = (rfd == wfd) ? rfd : -1;
326 c->extended_usage = extusage;
328 if ((c->isatty = is_tty) != 0)
329 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
331 /* XXX: Later AIX versions can't push as much data to tty */
332 c->wfd_isatty = is_tty || isatty(c->wfd);
335 /* enable nonblocking mode */
347 * Allocate a new channel object and set its type and socket. This will cause
348 * remote_name to be freed.
351 channel_new(struct ssh *ssh, char *ctype, int type, int rfd, int wfd, int efd,
352 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
354 struct ssh_channels *sc = ssh->chanctxt;
358 /* Try to find a free slot where to put the new channel. */
359 for (i = 0; i < sc->channels_alloc; i++) {
360 if (sc->channels[i] == NULL) {
361 /* Found a free slot. */
366 if (i >= sc->channels_alloc) {
368 * There are no free slots. Take last+1 slot and expand
371 found = sc->channels_alloc;
372 if (sc->channels_alloc > CHANNELS_MAX_CHANNELS)
373 fatal("%s: internal error: channels_alloc %d too big",
374 __func__, sc->channels_alloc);
375 sc->channels = xrecallocarray(sc->channels, sc->channels_alloc,
376 sc->channels_alloc + 10, sizeof(*sc->channels));
377 sc->channels_alloc += 10;
378 debug2("channel: expanding %d", sc->channels_alloc);
380 /* Initialize and return new channel. */
381 c = sc->channels[found] = xcalloc(1, sizeof(Channel));
382 if ((c->input = sshbuf_new()) == NULL ||
383 (c->output = sshbuf_new()) == NULL ||
384 (c->extended = sshbuf_new()) == NULL)
385 fatal("%s: sshbuf_new failed", __func__);
386 c->ostate = CHAN_OUTPUT_OPEN;
387 c->istate = CHAN_INPUT_OPEN;
388 channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, 0);
392 c->local_window = window;
393 c->local_window_max = window;
394 c->local_maxpacket = maxpack;
395 c->remote_name = xstrdup(remote_name);
397 c->delayed = 1; /* prevent call to channel_post handler */
398 TAILQ_INIT(&c->status_confirms);
399 debug("channel %d: new [%s]", found, remote_name);
404 channel_find_maxfd(struct ssh_channels *sc)
410 for (i = 0; i < sc->channels_alloc; i++) {
413 max = MAXIMUM(max, c->rfd);
414 max = MAXIMUM(max, c->wfd);
415 max = MAXIMUM(max, c->efd);
418 sc->channel_max_fd = max;
422 channel_close_fd(struct ssh *ssh, int *fdp)
424 struct ssh_channels *sc = ssh->chanctxt;
425 int ret = 0, fd = *fdp;
430 if (fd == sc->channel_max_fd)
431 channel_find_maxfd(sc);
436 /* Close all channel fd/socket. */
438 channel_close_fds(struct ssh *ssh, Channel *c)
440 int sock = c->sock, rfd = c->rfd, wfd = c->wfd, efd = c->efd;
442 channel_close_fd(ssh, &c->sock);
444 channel_close_fd(ssh, &c->rfd);
445 if (wfd != sock && wfd != rfd)
446 channel_close_fd(ssh, &c->wfd);
447 if (efd != sock && efd != rfd && efd != wfd)
448 channel_close_fd(ssh, &c->efd);
452 fwd_perm_clear(struct permission *perm)
454 free(perm->host_to_connect);
455 free(perm->listen_host);
456 free(perm->listen_path);
457 bzero(perm, sizeof(*perm));
460 /* Returns an printable name for the specified forwarding permission list */
462 fwd_ident(int who, int where)
464 if (who == FORWARD_ADM) {
465 if (where == FORWARD_LOCAL)
466 return "admin local";
467 else if (where == FORWARD_REMOTE)
468 return "admin remote";
469 } else if (who == FORWARD_USER) {
470 if (where == FORWARD_LOCAL)
472 else if (where == FORWARD_REMOTE)
473 return "user remote";
475 fatal("Unknown forward permission list %d/%d", who, where);
478 /* Returns the forwarding permission list for the specified direction */
479 static struct permission_set *
480 permission_set_get(struct ssh *ssh, int where)
482 struct ssh_channels *sc = ssh->chanctxt;
486 return &sc->local_perms;
489 return &sc->remote_perms;
492 fatal("%s: invalid forwarding direction %d", __func__, where);
496 /* Reutrns pointers to the specified forwarding list and its element count */
498 permission_set_get_array(struct ssh *ssh, int who, int where,
499 struct permission ***permpp, u_int **npermpp)
501 struct permission_set *pset = permission_set_get(ssh, where);
505 *permpp = &pset->permitted_user;
506 *npermpp = &pset->num_permitted_user;
509 *permpp = &pset->permitted_admin;
510 *npermpp = &pset->num_permitted_admin;
513 fatal("%s: invalid forwarding client %d", __func__, who);
517 /* Adds an entry to the spcified forwarding list */
519 permission_set_add(struct ssh *ssh, int who, int where,
520 const char *host_to_connect, int port_to_connect,
521 const char *listen_host, const char *listen_path, int listen_port,
524 struct permission **permp;
527 permission_set_get_array(ssh, who, where, &permp, &npermp);
529 if (*npermp >= INT_MAX)
530 fatal("%s: %s overflow", __func__, fwd_ident(who, where));
532 *permp = xrecallocarray(*permp, *npermp, *npermp + 1, sizeof(**permp));
534 #define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
535 (*permp)[n].host_to_connect = MAYBE_DUP(host_to_connect);
536 (*permp)[n].port_to_connect = port_to_connect;
537 (*permp)[n].listen_host = MAYBE_DUP(listen_host);
538 (*permp)[n].listen_path = MAYBE_DUP(listen_path);
539 (*permp)[n].listen_port = listen_port;
540 (*permp)[n].downstream = downstream;
546 mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
548 struct ssh_channels *sc = ssh->chanctxt;
549 struct permission_set *pset = &sc->local_perms;
550 struct permission *perm;
554 for (i = 0; i < pset->num_permitted_user; i++) {
555 perm = &pset->permitted_user[i];
556 if (perm->downstream != c)
559 /* cancel on the server, since mux client is gone */
560 debug("channel %d: cleanup remote forward for %s:%u",
561 c->self, perm->listen_host, perm->listen_port);
562 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
563 (r = sshpkt_put_cstring(ssh,
564 "cancel-tcpip-forward")) != 0 ||
565 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
566 (r = sshpkt_put_cstring(ssh,
567 channel_rfwd_bind_host(perm->listen_host))) != 0 ||
568 (r = sshpkt_put_u32(ssh, perm->listen_port)) != 0 ||
569 (r = sshpkt_send(ssh)) != 0) {
570 fatal("%s: channel %i: %s", __func__,
571 c->self, ssh_err(r));
573 fwd_perm_clear(perm); /* unregister */
577 /* Free the channel and close its fd/socket. */
579 channel_free(struct ssh *ssh, Channel *c)
581 struct ssh_channels *sc = ssh->chanctxt;
585 struct channel_confirm *cc;
587 for (n = 0, i = 0; i < sc->channels_alloc; i++) {
588 if ((other = sc->channels[i]) == NULL)
591 /* detach from mux client and prepare for closing */
592 if (c->type == SSH_CHANNEL_MUX_CLIENT &&
593 other->type == SSH_CHANNEL_MUX_PROXY &&
594 other->mux_ctx == c) {
595 other->mux_ctx = NULL;
596 other->type = SSH_CHANNEL_OPEN;
597 other->istate = CHAN_INPUT_CLOSED;
598 other->ostate = CHAN_OUTPUT_CLOSED;
601 debug("channel %d: free: %s, nchannels %u", c->self,
602 c->remote_name ? c->remote_name : "???", n);
604 if (c->type == SSH_CHANNEL_MUX_CLIENT)
605 mux_remove_remote_forwardings(ssh, c);
607 if (log_level_get() >= SYSLOG_LEVEL_DEBUG3) {
608 s = channel_open_message(ssh);
609 debug3("channel %d: status: %s", c->self, s);
613 channel_close_fds(ssh, c);
614 sshbuf_free(c->input);
615 sshbuf_free(c->output);
616 sshbuf_free(c->extended);
617 c->input = c->output = c->extended = NULL;
618 free(c->remote_name);
619 c->remote_name = NULL;
622 free(c->listening_addr);
623 c->listening_addr = NULL;
624 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
625 if (cc->abandon_cb != NULL)
626 cc->abandon_cb(ssh, c, cc->ctx);
627 TAILQ_REMOVE(&c->status_confirms, cc, entry);
628 explicit_bzero(cc, sizeof(*cc));
631 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
632 c->filter_cleanup(ssh, c->self, c->filter_ctx);
633 sc->channels[c->self] = NULL;
634 explicit_bzero(c, sizeof(*c));
639 channel_free_all(struct ssh *ssh)
643 for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
644 if (ssh->chanctxt->channels[i] != NULL)
645 channel_free(ssh, ssh->chanctxt->channels[i]);
649 * Closes the sockets/fds of all channels. This is used to close extra file
650 * descriptors after a fork.
653 channel_close_all(struct ssh *ssh)
657 for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
658 if (ssh->chanctxt->channels[i] != NULL)
659 channel_close_fds(ssh, ssh->chanctxt->channels[i]);
663 * Stop listening to channels.
666 channel_stop_listening(struct ssh *ssh)
671 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
672 c = ssh->chanctxt->channels[i];
675 case SSH_CHANNEL_AUTH_SOCKET:
676 case SSH_CHANNEL_PORT_LISTENER:
677 case SSH_CHANNEL_RPORT_LISTENER:
678 case SSH_CHANNEL_X11_LISTENER:
679 case SSH_CHANNEL_UNIX_LISTENER:
680 case SSH_CHANNEL_RUNIX_LISTENER:
681 channel_close_fd(ssh, &c->sock);
682 channel_free(ssh, c);
690 * Returns true if no channel has too much buffered data, and false if one or
691 * more channel is overfull.
694 channel_not_very_much_buffered_data(struct ssh *ssh)
697 u_int maxsize = ssh_packet_get_maxsize(ssh);
700 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
701 c = ssh->chanctxt->channels[i];
702 if (c == NULL || c->type != SSH_CHANNEL_OPEN)
704 if (sshbuf_len(c->output) > maxsize) {
705 debug2("channel %d: big output buffer %zu > %u",
706 c->self, sshbuf_len(c->output), maxsize);
713 /* Returns true if any channel is still open. */
715 channel_still_open(struct ssh *ssh)
720 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
721 c = ssh->chanctxt->channels[i];
725 case SSH_CHANNEL_X11_LISTENER:
726 case SSH_CHANNEL_PORT_LISTENER:
727 case SSH_CHANNEL_RPORT_LISTENER:
728 case SSH_CHANNEL_MUX_LISTENER:
729 case SSH_CHANNEL_CLOSED:
730 case SSH_CHANNEL_AUTH_SOCKET:
731 case SSH_CHANNEL_DYNAMIC:
732 case SSH_CHANNEL_RDYNAMIC_OPEN:
733 case SSH_CHANNEL_CONNECTING:
734 case SSH_CHANNEL_ZOMBIE:
735 case SSH_CHANNEL_ABANDONED:
736 case SSH_CHANNEL_UNIX_LISTENER:
737 case SSH_CHANNEL_RUNIX_LISTENER:
739 case SSH_CHANNEL_LARVAL:
741 case SSH_CHANNEL_OPENING:
742 case SSH_CHANNEL_OPEN:
743 case SSH_CHANNEL_RDYNAMIC_FINISH:
744 case SSH_CHANNEL_X11_OPEN:
745 case SSH_CHANNEL_MUX_CLIENT:
746 case SSH_CHANNEL_MUX_PROXY:
749 fatal("%s: bad channel type %d", __func__, c->type);
756 /* Returns the id of an open channel suitable for keepaliving */
758 channel_find_open(struct ssh *ssh)
763 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
764 c = ssh->chanctxt->channels[i];
765 if (c == NULL || !c->have_remote_id)
768 case SSH_CHANNEL_CLOSED:
769 case SSH_CHANNEL_DYNAMIC:
770 case SSH_CHANNEL_RDYNAMIC_OPEN:
771 case SSH_CHANNEL_RDYNAMIC_FINISH:
772 case SSH_CHANNEL_X11_LISTENER:
773 case SSH_CHANNEL_PORT_LISTENER:
774 case SSH_CHANNEL_RPORT_LISTENER:
775 case SSH_CHANNEL_MUX_LISTENER:
776 case SSH_CHANNEL_MUX_CLIENT:
777 case SSH_CHANNEL_MUX_PROXY:
778 case SSH_CHANNEL_OPENING:
779 case SSH_CHANNEL_CONNECTING:
780 case SSH_CHANNEL_ZOMBIE:
781 case SSH_CHANNEL_ABANDONED:
782 case SSH_CHANNEL_UNIX_LISTENER:
783 case SSH_CHANNEL_RUNIX_LISTENER:
785 case SSH_CHANNEL_LARVAL:
786 case SSH_CHANNEL_AUTH_SOCKET:
787 case SSH_CHANNEL_OPEN:
788 case SSH_CHANNEL_X11_OPEN:
791 fatal("%s: bad channel type %d", __func__, c->type);
798 /* Returns the state of the channel's extended usage flag */
800 channel_format_extended_usage(const Channel *c)
805 switch (c->extended_usage) {
806 case CHAN_EXTENDED_WRITE:
808 case CHAN_EXTENDED_READ:
810 case CHAN_EXTENDED_IGNORE:
818 channel_format_status(const Channel *c)
822 xasprintf(&ret, "t%d %s%u i%u/%zu o%u/%zu e[%s]/%zu "
823 "fd %d/%d/%d sock %d cc %d",
825 c->have_remote_id ? "r" : "nr", c->remote_id,
826 c->istate, sshbuf_len(c->input),
827 c->ostate, sshbuf_len(c->output),
828 channel_format_extended_usage(c), sshbuf_len(c->extended),
829 c->rfd, c->wfd, c->efd, c->sock, c->ctl_chan);
834 * Returns a message describing the currently open forwarded connections,
835 * suitable for sending to the client. The message contains crlf pairs for
839 channel_open_message(struct ssh *ssh)
847 if ((buf = sshbuf_new()) == NULL)
848 fatal("%s: sshbuf_new", __func__);
849 if ((r = sshbuf_putf(buf,
850 "The following connections are open:\r\n")) != 0)
851 fatal("%s: sshbuf_putf: %s", __func__, ssh_err(r));
852 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
853 c = ssh->chanctxt->channels[i];
857 case SSH_CHANNEL_X11_LISTENER:
858 case SSH_CHANNEL_PORT_LISTENER:
859 case SSH_CHANNEL_RPORT_LISTENER:
860 case SSH_CHANNEL_CLOSED:
861 case SSH_CHANNEL_AUTH_SOCKET:
862 case SSH_CHANNEL_ZOMBIE:
863 case SSH_CHANNEL_ABANDONED:
864 case SSH_CHANNEL_MUX_LISTENER:
865 case SSH_CHANNEL_UNIX_LISTENER:
866 case SSH_CHANNEL_RUNIX_LISTENER:
868 case SSH_CHANNEL_LARVAL:
869 case SSH_CHANNEL_OPENING:
870 case SSH_CHANNEL_CONNECTING:
871 case SSH_CHANNEL_DYNAMIC:
872 case SSH_CHANNEL_RDYNAMIC_OPEN:
873 case SSH_CHANNEL_RDYNAMIC_FINISH:
874 case SSH_CHANNEL_OPEN:
875 case SSH_CHANNEL_X11_OPEN:
876 case SSH_CHANNEL_MUX_PROXY:
877 case SSH_CHANNEL_MUX_CLIENT:
878 cp = channel_format_status(c);
879 if ((r = sshbuf_putf(buf, " #%d %.300s (%s)\r\n",
880 c->self, c->remote_name, cp)) != 0) {
882 fatal("%s: sshbuf_putf: %s",
883 __func__, ssh_err(r));
888 fatal("%s: bad channel type %d", __func__, c->type);
892 if ((ret = sshbuf_dup_string(buf)) == NULL)
893 fatal("%s: sshbuf_dup_string", __func__);
899 open_preamble(struct ssh *ssh, const char *where, Channel *c, const char *type)
903 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
904 (r = sshpkt_put_cstring(ssh, type)) != 0 ||
905 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
906 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
907 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
908 fatal("%s: channel %i: open: %s", where, c->self, ssh_err(r));
913 channel_send_open(struct ssh *ssh, int id)
915 Channel *c = channel_lookup(ssh, id);
919 logit("channel_send_open: %d: bad id", id);
922 debug2("channel %d: send open", id);
923 open_preamble(ssh, __func__, c, c->ctype);
924 if ((r = sshpkt_send(ssh)) != 0)
925 fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
929 channel_request_start(struct ssh *ssh, int id, char *service, int wantconfirm)
931 Channel *c = channel_lookup(ssh, id);
935 logit("%s: %d: unknown channel id", __func__, id);
938 if (!c->have_remote_id)
939 fatal(":%s: channel %d: no remote id", __func__, c->self);
941 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
942 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
943 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
944 (r = sshpkt_put_cstring(ssh, service)) != 0 ||
945 (r = sshpkt_put_u8(ssh, wantconfirm)) != 0) {
946 fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
951 channel_register_status_confirm(struct ssh *ssh, int id,
952 channel_confirm_cb *cb, channel_confirm_abandon_cb *abandon_cb, void *ctx)
954 struct channel_confirm *cc;
957 if ((c = channel_lookup(ssh, id)) == NULL)
958 fatal("%s: %d: bad id", __func__, id);
960 cc = xcalloc(1, sizeof(*cc));
962 cc->abandon_cb = abandon_cb;
964 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
968 channel_register_open_confirm(struct ssh *ssh, int id,
969 channel_open_fn *fn, void *ctx)
971 Channel *c = channel_lookup(ssh, id);
974 logit("%s: %d: bad id", __func__, id);
977 c->open_confirm = fn;
978 c->open_confirm_ctx = ctx;
982 channel_register_cleanup(struct ssh *ssh, int id,
983 channel_callback_fn *fn, int do_close)
985 Channel *c = channel_by_id(ssh, id);
988 logit("%s: %d: bad id", __func__, id);
992 c->detach_close = do_close;
996 channel_cancel_cleanup(struct ssh *ssh, int id)
998 Channel *c = channel_by_id(ssh, id);
1001 logit("%s: %d: bad id", __func__, id);
1004 c->detach_user = NULL;
1005 c->detach_close = 0;
1009 channel_register_filter(struct ssh *ssh, int id, channel_infilter_fn *ifn,
1010 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1012 Channel *c = channel_lookup(ssh, id);
1015 logit("%s: %d: bad id", __func__, id);
1018 c->input_filter = ifn;
1019 c->output_filter = ofn;
1020 c->filter_ctx = ctx;
1021 c->filter_cleanup = cfn;
1025 channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
1026 int extusage, int nonblock, int is_tty, u_int window_max)
1028 Channel *c = channel_lookup(ssh, id);
1031 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
1032 fatal("channel_activate for non-larval channel %d.", id);
1033 if (!c->have_remote_id)
1034 fatal(":%s: channel %d: no remote id", __func__, c->self);
1036 channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, is_tty);
1037 c->type = SSH_CHANNEL_OPEN;
1038 c->local_window = c->local_window_max = window_max;
1040 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
1041 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1042 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1043 (r = sshpkt_send(ssh)) != 0)
1044 fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1048 channel_pre_listener(struct ssh *ssh, Channel *c,
1049 fd_set *readset, fd_set *writeset)
1051 FD_SET(c->sock, readset);
1055 channel_pre_connecting(struct ssh *ssh, Channel *c,
1056 fd_set *readset, fd_set *writeset)
1058 debug3("channel %d: waiting for connection", c->self);
1059 FD_SET(c->sock, writeset);
1063 channel_pre_open(struct ssh *ssh, Channel *c,
1064 fd_set *readset, fd_set *writeset)
1066 if (c->istate == CHAN_INPUT_OPEN &&
1067 c->remote_window > 0 &&
1068 sshbuf_len(c->input) < c->remote_window &&
1069 sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1070 FD_SET(c->rfd, readset);
1071 if (c->ostate == CHAN_OUTPUT_OPEN ||
1072 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1073 if (sshbuf_len(c->output) > 0) {
1074 FD_SET(c->wfd, writeset);
1075 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1076 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1077 debug2("channel %d: "
1078 "obuf_empty delayed efd %d/(%zu)", c->self,
1079 c->efd, sshbuf_len(c->extended));
1081 chan_obuf_empty(ssh, c);
1084 /** XXX check close conditions, too */
1085 if (c->efd != -1 && !(c->istate == CHAN_INPUT_CLOSED &&
1086 c->ostate == CHAN_OUTPUT_CLOSED)) {
1087 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1088 sshbuf_len(c->extended) > 0)
1089 FD_SET(c->efd, writeset);
1090 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
1091 (c->extended_usage == CHAN_EXTENDED_READ ||
1092 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1093 sshbuf_len(c->extended) < c->remote_window)
1094 FD_SET(c->efd, readset);
1096 /* XXX: What about efd? races? */
1100 * This is a special state for X11 authentication spoofing. An opened X11
1101 * connection (when authentication spoofing is being done) remains in this
1102 * state until the first packet has been completely read. The authentication
1103 * data in that packet is then substituted by the real data if it matches the
1104 * fake data, and the channel is put into normal mode.
1105 * XXX All this happens at the client side.
1106 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1109 x11_open_helper(struct ssh *ssh, struct sshbuf *b)
1111 struct ssh_channels *sc = ssh->chanctxt;
1113 u_int proto_len, data_len;
1115 /* Is this being called after the refusal deadline? */
1116 if (sc->x11_refuse_time != 0 &&
1117 (u_int)monotime() >= sc->x11_refuse_time) {
1118 verbose("Rejected X11 connection after ForwardX11Timeout "
1123 /* Check if the fixed size part of the packet is in buffer. */
1124 if (sshbuf_len(b) < 12)
1127 /* Parse the lengths of variable-length fields. */
1128 ucp = sshbuf_mutable_ptr(b);
1129 if (ucp[0] == 0x42) { /* Byte order MSB first. */
1130 proto_len = 256 * ucp[6] + ucp[7];
1131 data_len = 256 * ucp[8] + ucp[9];
1132 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
1133 proto_len = ucp[6] + 256 * ucp[7];
1134 data_len = ucp[8] + 256 * ucp[9];
1136 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1141 /* Check if the whole packet is in buffer. */
1143 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
1146 /* Check if authentication protocol matches. */
1147 if (proto_len != strlen(sc->x11_saved_proto) ||
1148 memcmp(ucp + 12, sc->x11_saved_proto, proto_len) != 0) {
1149 debug2("X11 connection uses different authentication protocol.");
1152 /* Check if authentication data matches our fake data. */
1153 if (data_len != sc->x11_fake_data_len ||
1154 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1155 sc->x11_fake_data, sc->x11_fake_data_len) != 0) {
1156 debug2("X11 auth data does not match fake data.");
1159 /* Check fake data length */
1160 if (sc->x11_fake_data_len != sc->x11_saved_data_len) {
1161 error("X11 fake_data_len %d != saved_data_len %d",
1162 sc->x11_fake_data_len, sc->x11_saved_data_len);
1166 * Received authentication protocol and data match
1167 * our fake data. Substitute the fake data with real
1170 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
1171 sc->x11_saved_data, sc->x11_saved_data_len);
1176 channel_pre_x11_open(struct ssh *ssh, Channel *c,
1177 fd_set *readset, fd_set *writeset)
1179 int ret = x11_open_helper(ssh, c->output);
1181 /* c->force_drain = 1; */
1184 c->type = SSH_CHANNEL_OPEN;
1185 channel_pre_open(ssh, c, readset, writeset);
1186 } else if (ret == -1) {
1187 logit("X11 connection rejected because of wrong authentication.");
1188 debug2("X11 rejected %d i%d/o%d",
1189 c->self, c->istate, c->ostate);
1190 chan_read_failed(ssh, c);
1191 sshbuf_reset(c->input);
1192 chan_ibuf_empty(ssh, c);
1193 sshbuf_reset(c->output);
1194 chan_write_failed(ssh, c);
1195 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1200 channel_pre_mux_client(struct ssh *ssh,
1201 Channel *c, fd_set *readset, fd_set *writeset)
1203 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1204 sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1205 FD_SET(c->rfd, readset);
1206 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1207 /* clear buffer immediately (discard any partial packet) */
1208 sshbuf_reset(c->input);
1209 chan_ibuf_empty(ssh, c);
1210 /* Start output drain. XXX just kill chan? */
1211 chan_rcvd_oclose(ssh, c);
1213 if (c->ostate == CHAN_OUTPUT_OPEN ||
1214 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1215 if (sshbuf_len(c->output) > 0)
1216 FD_SET(c->wfd, writeset);
1217 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1218 chan_obuf_empty(ssh, c);
1222 /* try to decode a socks4 header */
1224 channel_decode_socks4(Channel *c, struct sshbuf *input, struct sshbuf *output)
1228 u_int len, have, i, found, need;
1233 u_int16_t dest_port;
1234 struct in_addr dest_addr;
1238 debug2("channel %d: decode socks4", c->self);
1240 have = sshbuf_len(input);
1241 len = sizeof(s4_req);
1244 p = sshbuf_ptr(input);
1247 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1248 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1249 debug2("channel %d: socks4a request", c->self);
1250 /* ... and needs an extra string (the hostname) */
1253 /* Check for terminating NUL on the string(s) */
1254 for (found = 0, i = len; i < have; i++) {
1261 /* the peer is probably sending garbage */
1262 debug("channel %d: decode socks4: too long",
1269 if ((r = sshbuf_get(input, &s4_req.version, 1)) != 0 ||
1270 (r = sshbuf_get(input, &s4_req.command, 1)) != 0 ||
1271 (r = sshbuf_get(input, &s4_req.dest_port, 2)) != 0 ||
1272 (r = sshbuf_get(input, &s4_req.dest_addr, 4)) != 0) {
1273 debug("channels %d: decode socks4: %s", c->self, ssh_err(r));
1276 have = sshbuf_len(input);
1277 p = sshbuf_ptr(input);
1278 if (memchr(p, '\0', have) == NULL) {
1279 error("channel %d: decode socks4: user not nul terminated",
1284 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1285 len++; /* trailing '\0' */
1286 strlcpy(username, p, sizeof(username));
1287 if ((r = sshbuf_consume(input, len)) != 0) {
1288 fatal("%s: channel %d: consume: %s", __func__,
1289 c->self, ssh_err(r));
1293 if (need == 1) { /* SOCKS4: one string */
1294 host = inet_ntoa(s4_req.dest_addr);
1295 c->path = xstrdup(host);
1296 } else { /* SOCKS4A: two strings */
1297 have = sshbuf_len(input);
1298 p = sshbuf_ptr(input);
1299 if (memchr(p, '\0', have) == NULL) {
1300 error("channel %d: decode socks4a: host not nul "
1301 "terminated", c->self);
1305 debug2("channel %d: decode socks4a: host %s/%d",
1307 len++; /* trailing '\0' */
1308 if (len > NI_MAXHOST) {
1309 error("channel %d: hostname \"%.100s\" too long",
1313 c->path = xstrdup(p);
1314 if ((r = sshbuf_consume(input, len)) != 0) {
1315 fatal("%s: channel %d: consume: %s", __func__,
1316 c->self, ssh_err(r));
1319 c->host_port = ntohs(s4_req.dest_port);
1321 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1322 c->self, c->path, c->host_port, s4_req.command);
1324 if (s4_req.command != 1) {
1325 debug("channel %d: cannot handle: %s cn %d",
1326 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1329 s4_rsp.version = 0; /* vn: 0 for reply */
1330 s4_rsp.command = 90; /* cd: req granted */
1331 s4_rsp.dest_port = 0; /* ignored */
1332 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1333 if ((r = sshbuf_put(output, &s4_rsp, sizeof(s4_rsp))) != 0) {
1334 fatal("%s: channel %d: append reply: %s", __func__,
1335 c->self, ssh_err(r));
1340 /* try to decode a socks5 header */
1341 #define SSH_SOCKS5_AUTHDONE 0x1000
1342 #define SSH_SOCKS5_NOAUTH 0x00
1343 #define SSH_SOCKS5_IPV4 0x01
1344 #define SSH_SOCKS5_DOMAIN 0x03
1345 #define SSH_SOCKS5_IPV6 0x04
1346 #define SSH_SOCKS5_CONNECT 0x01
1347 #define SSH_SOCKS5_SUCCESS 0x00
1350 channel_decode_socks5(Channel *c, struct sshbuf *input, struct sshbuf *output)
1352 /* XXX use get/put_u8 instead of trusting struct padding */
1359 u_int16_t dest_port;
1360 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1362 u_int have, need, i, found, nmethods, addrlen, af;
1365 debug2("channel %d: decode socks5", c->self);
1366 p = sshbuf_ptr(input);
1369 have = sshbuf_len(input);
1370 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1371 /* format: ver | nmethods | methods */
1375 if (have < nmethods + 2)
1377 /* look for method: "NO AUTHENTICATION REQUIRED" */
1378 for (found = 0, i = 2; i < nmethods + 2; i++) {
1379 if (p[i] == SSH_SOCKS5_NOAUTH) {
1385 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1389 if ((r = sshbuf_consume(input, nmethods + 2)) != 0) {
1390 fatal("%s: channel %d: consume: %s", __func__,
1391 c->self, ssh_err(r));
1393 /* version, method */
1394 if ((r = sshbuf_put_u8(output, 0x05)) != 0 ||
1395 (r = sshbuf_put_u8(output, SSH_SOCKS5_NOAUTH)) != 0) {
1396 fatal("%s: channel %d: append reply: %s", __func__,
1397 c->self, ssh_err(r));
1399 c->flags |= SSH_SOCKS5_AUTHDONE;
1400 debug2("channel %d: socks5 auth done", c->self);
1401 return 0; /* need more */
1403 debug2("channel %d: socks5 post auth", c->self);
1404 if (have < sizeof(s5_req)+1)
1405 return 0; /* need more */
1406 memcpy(&s5_req, p, sizeof(s5_req));
1407 if (s5_req.version != 0x05 ||
1408 s5_req.command != SSH_SOCKS5_CONNECT ||
1409 s5_req.reserved != 0x00) {
1410 debug2("channel %d: only socks5 connect supported", c->self);
1413 switch (s5_req.atyp){
1414 case SSH_SOCKS5_IPV4:
1418 case SSH_SOCKS5_DOMAIN:
1419 addrlen = p[sizeof(s5_req)];
1422 case SSH_SOCKS5_IPV6:
1427 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1430 need = sizeof(s5_req) + addrlen + 2;
1431 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1435 if ((r = sshbuf_consume(input, sizeof(s5_req))) != 0) {
1436 fatal("%s: channel %d: consume: %s", __func__,
1437 c->self, ssh_err(r));
1439 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1440 /* host string length */
1441 if ((r = sshbuf_consume(input, 1)) != 0) {
1442 fatal("%s: channel %d: consume: %s", __func__,
1443 c->self, ssh_err(r));
1446 if ((r = sshbuf_get(input, &dest_addr, addrlen)) != 0 ||
1447 (r = sshbuf_get(input, &dest_port, 2)) != 0) {
1448 debug("channel %d: parse addr/port: %s", c->self, ssh_err(r));
1451 dest_addr[addrlen] = '\0';
1454 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1455 if (addrlen >= NI_MAXHOST) {
1456 error("channel %d: dynamic request: socks5 hostname "
1457 "\"%.100s\" too long", c->self, dest_addr);
1460 c->path = xstrdup(dest_addr);
1462 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1464 c->path = xstrdup(ntop);
1466 c->host_port = ntohs(dest_port);
1468 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1469 c->self, c->path, c->host_port, s5_req.command);
1471 s5_rsp.version = 0x05;
1472 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1473 s5_rsp.reserved = 0; /* ignored */
1474 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1475 dest_port = 0; /* ignored */
1477 if ((r = sshbuf_put(output, &s5_rsp, sizeof(s5_rsp))) != 0 ||
1478 (r = sshbuf_put_u32(output, ntohl(INADDR_ANY))) != 0 ||
1479 (r = sshbuf_put(output, &dest_port, sizeof(dest_port))) != 0)
1480 fatal("%s: channel %d: append reply: %s", __func__,
1481 c->self, ssh_err(r));
1486 channel_connect_stdio_fwd(struct ssh *ssh,
1487 const char *host_to_connect, u_short port_to_connect, int in, int out)
1491 debug("%s %s:%d", __func__, host_to_connect, port_to_connect);
1493 c = channel_new(ssh, "stdio-forward", SSH_CHANNEL_OPENING, in, out,
1494 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1495 0, "stdio-forward", /*nonblock*/0);
1497 c->path = xstrdup(host_to_connect);
1498 c->host_port = port_to_connect;
1499 c->listening_port = 0;
1502 channel_register_fds(ssh, c, in, out, -1, 0, 1, 0);
1503 port_open_helper(ssh, c, "direct-tcpip");
1508 /* dynamic port forwarding */
1510 channel_pre_dynamic(struct ssh *ssh, Channel *c,
1511 fd_set *readset, fd_set *writeset)
1517 have = sshbuf_len(c->input);
1518 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1519 /* sshbuf_dump(c->input, stderr); */
1520 /* check if the fixed size part of the packet is in buffer. */
1523 FD_SET(c->sock, readset);
1526 /* try to guess the protocol */
1527 p = sshbuf_ptr(c->input);
1528 /* XXX sshbuf_peek_u8? */
1531 ret = channel_decode_socks4(c, c->input, c->output);
1534 ret = channel_decode_socks5(c, c->input, c->output);
1541 chan_mark_dead(ssh, c);
1542 } else if (ret == 0) {
1543 debug2("channel %d: pre_dynamic: need more", c->self);
1545 FD_SET(c->sock, readset);
1546 if (sshbuf_len(c->output))
1547 FD_SET(c->sock, writeset);
1549 /* switch to the next state */
1550 c->type = SSH_CHANNEL_OPENING;
1551 port_open_helper(ssh, c, "direct-tcpip");
1555 /* simulate read-error */
1557 rdynamic_close(struct ssh *ssh, Channel *c)
1559 c->type = SSH_CHANNEL_OPEN;
1560 chan_read_failed(ssh, c);
1561 sshbuf_reset(c->input);
1562 chan_ibuf_empty(ssh, c);
1563 sshbuf_reset(c->output);
1564 chan_write_failed(ssh, c);
1567 /* reverse dynamic port forwarding */
1569 channel_before_prepare_select_rdynamic(struct ssh *ssh, Channel *c)
1575 have = sshbuf_len(c->output);
1576 debug2("channel %d: pre_rdynamic: have %d", c->self, have);
1577 /* sshbuf_dump(c->output, stderr); */
1579 if (c->flags & CHAN_EOF_RCVD) {
1580 if ((r = sshbuf_consume(c->output, have)) != 0) {
1581 fatal("%s: channel %d: consume: %s",
1582 __func__, c->self, ssh_err(r));
1584 rdynamic_close(ssh, c);
1587 /* check if the fixed size part of the packet is in buffer. */
1590 /* try to guess the protocol */
1591 p = sshbuf_ptr(c->output);
1594 /* switch input/output for reverse forwarding */
1595 ret = channel_decode_socks4(c, c->output, c->input);
1598 ret = channel_decode_socks5(c, c->output, c->input);
1605 rdynamic_close(ssh, c);
1606 } else if (ret == 0) {
1607 debug2("channel %d: pre_rdynamic: need more", c->self);
1608 /* send socks request to peer */
1609 len = sshbuf_len(c->input);
1610 if (len > 0 && len < c->remote_window) {
1611 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
1612 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1613 (r = sshpkt_put_stringb(ssh, c->input)) != 0 ||
1614 (r = sshpkt_send(ssh)) != 0) {
1615 fatal("%s: channel %i: rdynamic: %s", __func__,
1616 c->self, ssh_err(r));
1618 if ((r = sshbuf_consume(c->input, len)) != 0) {
1619 fatal("%s: channel %d: consume: %s",
1620 __func__, c->self, ssh_err(r));
1622 c->remote_window -= len;
1624 } else if (rdynamic_connect_finish(ssh, c) < 0) {
1625 /* the connect failed */
1626 rdynamic_close(ssh, c);
1630 /* This is our fake X11 server socket. */
1632 channel_post_x11_listener(struct ssh *ssh, Channel *c,
1633 fd_set *readset, fd_set *writeset)
1636 struct sockaddr_storage addr;
1637 int r, newsock, oerrno, remote_port;
1639 char buf[16384], *remote_ipaddr;
1641 if (!FD_ISSET(c->sock, readset))
1644 debug("X11 connection requested.");
1645 addrlen = sizeof(addr);
1646 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1647 if (c->single_connection) {
1649 debug2("single_connection: closing X11 listener.");
1650 channel_close_fd(ssh, &c->sock);
1651 chan_mark_dead(ssh, c);
1655 if (errno != EINTR && errno != EWOULDBLOCK &&
1656 errno != ECONNABORTED)
1657 error("accept: %.100s", strerror(errno));
1658 if (errno == EMFILE || errno == ENFILE)
1659 c->notbefore = monotime() + 1;
1662 set_nodelay(newsock);
1663 remote_ipaddr = get_peer_ipaddr(newsock);
1664 remote_port = get_peer_port(newsock);
1665 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1666 remote_ipaddr, remote_port);
1668 nc = channel_new(ssh, "accepted x11 socket",
1669 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1670 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1671 open_preamble(ssh, __func__, nc, "x11");
1672 if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1673 (r = sshpkt_put_u32(ssh, remote_port)) != 0) {
1674 fatal("%s: channel %i: reply %s", __func__,
1675 c->self, ssh_err(r));
1677 if ((r = sshpkt_send(ssh)) != 0)
1678 fatal("%s: channel %i: send %s", __func__, c->self, ssh_err(r));
1679 free(remote_ipaddr);
1683 port_open_helper(struct ssh *ssh, Channel *c, char *rtype)
1685 char *local_ipaddr = get_local_ipaddr(c->sock);
1686 int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
1687 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1688 int remote_port = get_peer_port(c->sock);
1691 if (remote_port == -1) {
1692 /* Fake addr/port to appease peers that validate it (Tectia) */
1693 free(remote_ipaddr);
1694 remote_ipaddr = xstrdup("127.0.0.1");
1695 remote_port = 65535;
1698 free(c->remote_name);
1699 xasprintf(&c->remote_name,
1700 "%s: listening port %d for %.100s port %d, "
1701 "connect from %.200s port %d to %.100s port %d",
1702 rtype, c->listening_port, c->path, c->host_port,
1703 remote_ipaddr, remote_port, local_ipaddr, local_port);
1705 open_preamble(ssh, __func__, c, rtype);
1706 if (strcmp(rtype, "direct-tcpip") == 0) {
1707 /* target host, port */
1708 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1709 (r = sshpkt_put_u32(ssh, c->host_port)) != 0) {
1710 fatal("%s: channel %i: reply %s", __func__,
1711 c->self, ssh_err(r));
1713 } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1715 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0) {
1716 fatal("%s: channel %i: reply %s", __func__,
1717 c->self, ssh_err(r));
1719 } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1721 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0) {
1722 fatal("%s: channel %i: reply %s", __func__,
1723 c->self, ssh_err(r));
1726 /* listen address, port */
1727 if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1728 (r = sshpkt_put_u32(ssh, local_port)) != 0) {
1729 fatal("%s: channel %i: reply %s", __func__,
1730 c->self, ssh_err(r));
1733 if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1734 /* reserved for future owner/mode info */
1735 if ((r = sshpkt_put_cstring(ssh, "")) != 0) {
1736 fatal("%s: channel %i: reply %s", __func__,
1737 c->self, ssh_err(r));
1740 /* originator host and port */
1741 if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1742 (r = sshpkt_put_u32(ssh, (u_int)remote_port)) != 0) {
1743 fatal("%s: channel %i: reply %s", __func__,
1744 c->self, ssh_err(r));
1747 if ((r = sshpkt_send(ssh)) != 0)
1748 fatal("%s: channel %i: send %s", __func__, c->self, ssh_err(r));
1749 free(remote_ipaddr);
1754 channel_set_x11_refuse_time(struct ssh *ssh, u_int refuse_time)
1756 ssh->chanctxt->x11_refuse_time = refuse_time;
1760 * This socket is listening for connections to a forwarded TCP/IP port.
1763 channel_post_port_listener(struct ssh *ssh, Channel *c,
1764 fd_set *readset, fd_set *writeset)
1767 struct sockaddr_storage addr;
1768 int newsock, nextstate;
1772 if (!FD_ISSET(c->sock, readset))
1775 debug("Connection to port %d forwarding to %.100s port %d requested.",
1776 c->listening_port, c->path, c->host_port);
1778 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1779 nextstate = SSH_CHANNEL_OPENING;
1780 rtype = "forwarded-tcpip";
1781 } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1782 nextstate = SSH_CHANNEL_OPENING;
1783 rtype = "forwarded-streamlocal@openssh.com";
1784 } else if (c->host_port == PORT_STREAMLOCAL) {
1785 nextstate = SSH_CHANNEL_OPENING;
1786 rtype = "direct-streamlocal@openssh.com";
1787 } else if (c->host_port == 0) {
1788 nextstate = SSH_CHANNEL_DYNAMIC;
1789 rtype = "dynamic-tcpip";
1791 nextstate = SSH_CHANNEL_OPENING;
1792 rtype = "direct-tcpip";
1795 addrlen = sizeof(addr);
1796 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1798 if (errno != EINTR && errno != EWOULDBLOCK &&
1799 errno != ECONNABORTED)
1800 error("accept: %.100s", strerror(errno));
1801 if (errno == EMFILE || errno == ENFILE)
1802 c->notbefore = monotime() + 1;
1805 if (c->host_port != PORT_STREAMLOCAL)
1806 set_nodelay(newsock);
1807 nc = channel_new(ssh, rtype, nextstate, newsock, newsock, -1,
1808 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1809 nc->listening_port = c->listening_port;
1810 nc->host_port = c->host_port;
1811 if (c->path != NULL)
1812 nc->path = xstrdup(c->path);
1814 if (nextstate != SSH_CHANNEL_DYNAMIC)
1815 port_open_helper(ssh, nc, rtype);
1819 * This is the authentication agent socket listening for connections from
1823 channel_post_auth_listener(struct ssh *ssh, Channel *c,
1824 fd_set *readset, fd_set *writeset)
1828 struct sockaddr_storage addr;
1831 if (!FD_ISSET(c->sock, readset))
1834 addrlen = sizeof(addr);
1835 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1837 error("accept from auth socket: %.100s", strerror(errno));
1838 if (errno == EMFILE || errno == ENFILE)
1839 c->notbefore = monotime() + 1;
1842 nc = channel_new(ssh, "accepted auth socket",
1843 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1844 c->local_window_max, c->local_maxpacket,
1845 0, "accepted auth socket", 1);
1846 open_preamble(ssh, __func__, nc, "auth-agent@openssh.com");
1847 if ((r = sshpkt_send(ssh)) != 0)
1848 fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1852 channel_post_connecting(struct ssh *ssh, Channel *c,
1853 fd_set *readset, fd_set *writeset)
1855 int err = 0, sock, isopen, r;
1856 socklen_t sz = sizeof(err);
1858 if (!FD_ISSET(c->sock, writeset))
1860 if (!c->have_remote_id)
1861 fatal(":%s: channel %d: no remote id", __func__, c->self);
1862 /* for rdynamic the OPEN_CONFIRMATION has been sent already */
1863 isopen = (c->type == SSH_CHANNEL_RDYNAMIC_FINISH);
1864 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1866 error("getsockopt SO_ERROR failed");
1869 debug("channel %d: connected to %s port %d",
1870 c->self, c->connect_ctx.host, c->connect_ctx.port);
1871 channel_connect_ctx_free(&c->connect_ctx);
1872 c->type = SSH_CHANNEL_OPEN;
1874 /* no message necessary */
1876 if ((r = sshpkt_start(ssh,
1877 SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
1878 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1879 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1880 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1881 (r = sshpkt_put_u32(ssh, c->local_maxpacket))
1883 fatal("%s: channel %i: confirm: %s", __func__,
1884 c->self, ssh_err(r));
1885 if ((r = sshpkt_send(ssh)) != 0)
1886 fatal("%s: channel %i: %s", __func__, c->self,
1890 debug("channel %d: connection failed: %s",
1891 c->self, strerror(err));
1892 /* Try next address, if any */
1893 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1895 c->sock = c->rfd = c->wfd = sock;
1896 channel_find_maxfd(ssh->chanctxt);
1899 /* Exhausted all addresses */
1900 error("connect_to %.100s port %d: failed.",
1901 c->connect_ctx.host, c->connect_ctx.port);
1902 channel_connect_ctx_free(&c->connect_ctx);
1904 rdynamic_close(ssh, c);
1906 if ((r = sshpkt_start(ssh,
1907 SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
1908 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1909 (r = sshpkt_put_u32(ssh,
1910 SSH2_OPEN_CONNECT_FAILED)) != 0 ||
1911 (r = sshpkt_put_cstring(ssh, strerror(err))) != 0 ||
1912 (r = sshpkt_put_cstring(ssh, "")) != 0) {
1913 fatal("%s: channel %i: failure: %s", __func__,
1914 c->self, ssh_err(r));
1916 if ((r = sshpkt_send(ssh)) != 0)
1917 fatal("%s: channel %i: %s", __func__, c->self,
1919 chan_mark_dead(ssh, c);
1925 channel_handle_rfd(struct ssh *ssh, Channel *c,
1926 fd_set *readset, fd_set *writeset)
1928 char buf[CHAN_RBUF];
1932 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1934 if (c->rfd == -1 || (!force && !FD_ISSET(c->rfd, readset)))
1938 len = read(c->rfd, buf, sizeof(buf));
1939 if (len < 0 && (errno == EINTR ||
1940 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1942 #ifndef PTY_ZEROREAD
1945 if ((!c->isatty && len <= 0) ||
1946 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1948 debug2("channel %d: read<=0 rfd %d len %zd",
1949 c->self, c->rfd, len);
1950 if (c->type != SSH_CHANNEL_OPEN) {
1951 debug2("channel %d: not open", c->self);
1952 chan_mark_dead(ssh, c);
1955 chan_read_failed(ssh, c);
1959 if (c->input_filter != NULL) {
1960 if (c->input_filter(ssh, c, buf, len) == -1) {
1961 debug2("channel %d: filter stops", c->self);
1962 chan_read_failed(ssh, c);
1964 } else if (c->datagram) {
1965 if ((r = sshbuf_put_string(c->input, buf, len)) != 0)
1966 fatal("%s: channel %d: put datagram: %s", __func__,
1967 c->self, ssh_err(r));
1968 } else if ((r = sshbuf_put(c->input, buf, len)) != 0) {
1969 fatal("%s: channel %d: put data: %s", __func__,
1970 c->self, ssh_err(r));
1976 channel_handle_wfd(struct ssh *ssh, Channel *c,
1977 fd_set *readset, fd_set *writeset)
1980 u_char *data = NULL, *buf; /* XXX const; need filter API change */
1981 size_t dlen, olen = 0;
1984 if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
1985 sshbuf_len(c->output) == 0)
1988 /* Send buffered output data to the socket. */
1989 olen = sshbuf_len(c->output);
1990 if (c->output_filter != NULL) {
1991 if ((buf = c->output_filter(ssh, c, &data, &dlen)) == NULL) {
1992 debug2("channel %d: filter stops", c->self);
1993 if (c->type != SSH_CHANNEL_OPEN)
1994 chan_mark_dead(ssh, c);
1996 chan_write_failed(ssh, c);
1999 } else if (c->datagram) {
2000 if ((r = sshbuf_get_string(c->output, &data, &dlen)) != 0)
2001 fatal("%s: channel %d: get datagram: %s", __func__,
2002 c->self, ssh_err(r));
2005 buf = data = sshbuf_mutable_ptr(c->output);
2006 dlen = sshbuf_len(c->output);
2010 /* ignore truncated writes, datagrams might get lost */
2011 len = write(c->wfd, buf, dlen);
2013 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
2014 errno == EWOULDBLOCK))
2022 /* XXX: Later AIX versions can't push as much data to tty */
2024 dlen = MIN(dlen, 8*1024);
2027 len = write(c->wfd, buf, dlen);
2029 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
2033 if (c->type != SSH_CHANNEL_OPEN) {
2034 debug2("channel %d: not open", c->self);
2035 chan_mark_dead(ssh, c);
2038 chan_write_failed(ssh, c);
2042 #ifndef BROKEN_TCGETATTR_ICANON
2043 if (c->isatty && dlen >= 1 && buf[0] != '\r') {
2044 if (tcgetattr(c->wfd, &tio) == 0 &&
2045 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
2047 * Simulate echo to reduce the impact of
2048 * traffic analysis. We need to match the
2049 * size of a SSH2_MSG_CHANNEL_DATA message
2050 * (4 byte channel id + buf)
2052 if ((r = sshpkt_msg_ignore(ssh, 4+len)) != 0 ||
2053 (r = sshpkt_send(ssh)) != 0)
2054 fatal("%s: channel %d: ignore: %s",
2055 __func__, c->self, ssh_err(r));
2058 #endif /* BROKEN_TCGETATTR_ICANON */
2059 if ((r = sshbuf_consume(c->output, len)) != 0) {
2060 fatal("%s: channel %d: consume: %s",
2061 __func__, c->self, ssh_err(r));
2064 c->local_consumed += olen - sshbuf_len(c->output);
2070 channel_handle_efd_write(struct ssh *ssh, Channel *c,
2071 fd_set *readset, fd_set *writeset)
2076 if (!FD_ISSET(c->efd, writeset) || sshbuf_len(c->extended) == 0)
2079 len = write(c->efd, sshbuf_ptr(c->extended),
2080 sshbuf_len(c->extended));
2081 debug2("channel %d: written %zd to efd %d", c->self, len, c->efd);
2082 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
2083 errno == EWOULDBLOCK))
2086 debug2("channel %d: closing write-efd %d", c->self, c->efd);
2087 channel_close_fd(ssh, &c->efd);
2089 if ((r = sshbuf_consume(c->extended, len)) != 0) {
2090 fatal("%s: channel %d: consume: %s",
2091 __func__, c->self, ssh_err(r));
2093 c->local_consumed += len;
2099 channel_handle_efd_read(struct ssh *ssh, Channel *c,
2100 fd_set *readset, fd_set *writeset)
2102 char buf[CHAN_RBUF];
2106 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
2108 if (c->efd == -1 || (!force && !FD_ISSET(c->efd, readset)))
2111 len = read(c->efd, buf, sizeof(buf));
2112 debug2("channel %d: read %zd from efd %d", c->self, len, c->efd);
2113 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
2114 errno == EWOULDBLOCK) && !force)))
2117 debug2("channel %d: closing read-efd %d",
2119 channel_close_fd(ssh, &c->efd);
2121 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
2122 debug3("channel %d: discard efd",
2124 } else if ((r = sshbuf_put(c->extended, buf, len)) != 0) {
2125 fatal("%s: channel %d: append: %s",
2126 __func__, c->self, ssh_err(r));
2133 channel_handle_efd(struct ssh *ssh, Channel *c,
2134 fd_set *readset, fd_set *writeset)
2139 /** XXX handle drain efd, too */
2141 if (c->extended_usage == CHAN_EXTENDED_WRITE)
2142 return channel_handle_efd_write(ssh, c, readset, writeset);
2143 else if (c->extended_usage == CHAN_EXTENDED_READ ||
2144 c->extended_usage == CHAN_EXTENDED_IGNORE)
2145 return channel_handle_efd_read(ssh, c, readset, writeset);
2151 channel_check_window(struct ssh *ssh, Channel *c)
2155 if (c->type == SSH_CHANNEL_OPEN &&
2156 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
2157 ((c->local_window_max - c->local_window >
2158 c->local_maxpacket*3) ||
2159 c->local_window < c->local_window_max/2) &&
2160 c->local_consumed > 0) {
2161 if (!c->have_remote_id)
2162 fatal(":%s: channel %d: no remote id",
2164 if ((r = sshpkt_start(ssh,
2165 SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
2166 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2167 (r = sshpkt_put_u32(ssh, c->local_consumed)) != 0 ||
2168 (r = sshpkt_send(ssh)) != 0) {
2169 fatal("%s: channel %i: %s", __func__,
2170 c->self, ssh_err(r));
2172 debug2("channel %d: window %d sent adjust %d",
2173 c->self, c->local_window,
2175 c->local_window += c->local_consumed;
2176 c->local_consumed = 0;
2182 channel_post_open(struct ssh *ssh, Channel *c,
2183 fd_set *readset, fd_set *writeset)
2185 channel_handle_rfd(ssh, c, readset, writeset);
2186 channel_handle_wfd(ssh, c, readset, writeset);
2187 channel_handle_efd(ssh, c, readset, writeset);
2188 channel_check_window(ssh, c);
2192 read_mux(struct ssh *ssh, Channel *c, u_int need)
2194 char buf[CHAN_RBUF];
2199 if (sshbuf_len(c->input) < need) {
2200 rlen = need - sshbuf_len(c->input);
2201 len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
2202 if (len < 0 && (errno == EINTR || errno == EAGAIN))
2203 return sshbuf_len(c->input);
2205 debug2("channel %d: ctl read<=0 rfd %d len %zd",
2206 c->self, c->rfd, len);
2207 chan_read_failed(ssh, c);
2209 } else if ((r = sshbuf_put(c->input, buf, len)) != 0) {
2210 fatal("%s: channel %d: append: %s",
2211 __func__, c->self, ssh_err(r));
2214 return sshbuf_len(c->input);
2218 channel_post_mux_client_read(struct ssh *ssh, Channel *c,
2219 fd_set *readset, fd_set *writeset)
2223 if (c->rfd == -1 || !FD_ISSET(c->rfd, readset))
2225 if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
2231 * Don't not read past the precise end of packets to
2232 * avoid disrupting fd passing.
2234 if (read_mux(ssh, c, 4) < 4) /* read header */
2236 /* XXX sshbuf_peek_u32 */
2237 need = PEEK_U32(sshbuf_ptr(c->input));
2238 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
2239 if (need > CHANNEL_MUX_MAX_PACKET) {
2240 debug2("channel %d: packet too big %u > %u",
2241 c->self, CHANNEL_MUX_MAX_PACKET, need);
2242 chan_rcvd_oclose(ssh, c);
2245 if (read_mux(ssh, c, need + 4) < need + 4) /* read body */
2247 if (c->mux_rcb(ssh, c) != 0) {
2248 debug("channel %d: mux_rcb failed", c->self);
2249 chan_mark_dead(ssh, c);
2255 channel_post_mux_client_write(struct ssh *ssh, Channel *c,
2256 fd_set *readset, fd_set *writeset)
2261 if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
2262 sshbuf_len(c->output) == 0)
2265 len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
2266 if (len < 0 && (errno == EINTR || errno == EAGAIN))
2269 chan_mark_dead(ssh, c);
2272 if ((r = sshbuf_consume(c->output, len)) != 0)
2273 fatal("%s: channel %d: consume: %s", __func__,
2274 c->self, ssh_err(r));
2278 channel_post_mux_client(struct ssh *ssh, Channel *c,
2279 fd_set *readset, fd_set *writeset)
2281 channel_post_mux_client_read(ssh, c, readset, writeset);
2282 channel_post_mux_client_write(ssh, c, readset, writeset);
2286 channel_post_mux_listener(struct ssh *ssh, Channel *c,
2287 fd_set *readset, fd_set *writeset)
2290 struct sockaddr_storage addr;
2296 if (!FD_ISSET(c->sock, readset))
2299 debug("multiplexing control connection");
2302 * Accept connection on control socket
2304 memset(&addr, 0, sizeof(addr));
2305 addrlen = sizeof(addr);
2306 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
2308 error("%s accept: %s", __func__, strerror(errno));
2309 if (errno == EMFILE || errno == ENFILE)
2310 c->notbefore = monotime() + 1;
2314 if (getpeereid(newsock, &euid, &egid) < 0) {
2315 error("%s getpeereid failed: %s", __func__,
2320 if ((euid != 0) && (getuid() != euid)) {
2321 error("multiplex uid mismatch: peer euid %u != uid %u",
2322 (u_int)euid, (u_int)getuid());
2326 nc = channel_new(ssh, "multiplex client", SSH_CHANNEL_MUX_CLIENT,
2327 newsock, newsock, -1, c->local_window_max,
2328 c->local_maxpacket, 0, "mux-control", 1);
2329 nc->mux_rcb = c->mux_rcb;
2330 debug3("%s: new mux channel %d fd %d", __func__, nc->self, nc->sock);
2331 /* establish state */
2332 nc->mux_rcb(ssh, nc);
2333 /* mux state transitions must not elicit protocol messages */
2334 nc->flags |= CHAN_LOCAL;
2338 channel_handler_init(struct ssh_channels *sc)
2340 chan_fn **pre, **post;
2342 if ((pre = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*pre))) == NULL ||
2343 (post = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*post))) == NULL)
2344 fatal("%s: allocation failed", __func__);
2346 pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2347 pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2348 pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2349 pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2350 pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2351 pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
2352 pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2353 pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2354 pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2355 pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2356 pre[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_pre_connecting;
2357 pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2358 pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2360 post[SSH_CHANNEL_OPEN] = &channel_post_open;
2361 post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2362 post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2363 post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2364 post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
2365 post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2366 post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2367 post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2368 post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2369 post[SSH_CHANNEL_RDYNAMIC_FINISH] = &channel_post_connecting;
2370 post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2371 post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2373 sc->channel_pre = pre;
2374 sc->channel_post = post;
2377 /* gc dead channels */
2379 channel_garbage_collect(struct ssh *ssh, Channel *c)
2383 if (c->detach_user != NULL) {
2384 if (!chan_is_dead(ssh, c, c->detach_close))
2387 debug2("channel %d: gc: notify user", c->self);
2388 c->detach_user(ssh, c->self, NULL);
2389 /* if we still have a callback */
2390 if (c->detach_user != NULL)
2392 debug2("channel %d: gc: user detached", c->self);
2394 if (!chan_is_dead(ssh, c, 1))
2396 debug2("channel %d: garbage collecting", c->self);
2397 channel_free(ssh, c);
2400 enum channel_table { CHAN_PRE, CHAN_POST };
2403 channel_handler(struct ssh *ssh, int table,
2404 fd_set *readset, fd_set *writeset, time_t *unpause_secs)
2406 struct ssh_channels *sc = ssh->chanctxt;
2407 chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
2413 if (unpause_secs != NULL)
2415 for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
2416 c = sc->channels[i];
2420 if (table == CHAN_PRE)
2425 if (ftab[c->type] != NULL) {
2427 * Run handlers that are not paused.
2429 if (c->notbefore <= now)
2430 (*ftab[c->type])(ssh, c, readset, writeset);
2431 else if (unpause_secs != NULL) {
2433 * Collect the time that the earliest
2434 * channel comes off pause.
2436 debug3("%s: chan %d: skip for %d more seconds",
2438 (int)(c->notbefore - now));
2439 if (*unpause_secs == 0 ||
2440 (c->notbefore - now) < *unpause_secs)
2441 *unpause_secs = c->notbefore - now;
2444 channel_garbage_collect(ssh, c);
2446 if (unpause_secs != NULL && *unpause_secs != 0)
2447 debug3("%s: first channel unpauses in %d seconds",
2448 __func__, (int)*unpause_secs);
2452 * Create sockets before allocating the select bitmasks.
2453 * This is necessary for things that need to happen after reading
2454 * the network-input but before channel_prepare_select().
2457 channel_before_prepare_select(struct ssh *ssh)
2459 struct ssh_channels *sc = ssh->chanctxt;
2463 for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
2464 c = sc->channels[i];
2467 if (c->type == SSH_CHANNEL_RDYNAMIC_OPEN)
2468 channel_before_prepare_select_rdynamic(ssh, c);
2473 * Allocate/update select bitmasks and add any bits relevant to channels in
2477 channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
2478 int *maxfdp, u_int *nallocp, time_t *minwait_secs)
2480 u_int n, sz, nfdset;
2482 channel_before_prepare_select(ssh); /* might update channel_max_fd */
2484 n = MAXIMUM(*maxfdp, ssh->chanctxt->channel_max_fd);
2486 nfdset = howmany(n+1, NFDBITS);
2487 /* Explicitly test here, because xrealloc isn't always called */
2488 if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
2489 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2490 sz = nfdset * sizeof(fd_mask);
2492 /* perhaps check sz < nalloc/2 and shrink? */
2493 if (*readsetp == NULL || sz > *nallocp) {
2494 *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
2495 *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
2499 memset(*readsetp, 0, sz);
2500 memset(*writesetp, 0, sz);
2502 if (!ssh_packet_is_rekeying(ssh))
2503 channel_handler(ssh, CHAN_PRE, *readsetp, *writesetp,
2508 * After select, perform any appropriate operations for channels which have
2512 channel_after_select(struct ssh *ssh, fd_set *readset, fd_set *writeset)
2514 channel_handler(ssh, CHAN_POST, readset, writeset, NULL);
2518 * Enqueue data for channels with open or draining c->input.
2521 channel_output_poll_input_open(struct ssh *ssh, Channel *c)
2527 if ((len = sshbuf_len(c->input)) == 0) {
2528 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2530 * input-buffer is empty and read-socket shutdown:
2531 * tell peer, that we will not send more data:
2533 * hack for extended data: delay EOF if EFD still
2536 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2537 debug2("channel %d: "
2538 "ibuf_empty delayed efd %d/(%zu)",
2539 c->self, c->efd, sshbuf_len(c->extended));
2541 chan_ibuf_empty(ssh, c);
2546 if (!c->have_remote_id)
2547 fatal(":%s: channel %d: no remote id", __func__, c->self);
2550 /* Check datagram will fit; drop if not */
2551 if ((r = sshbuf_get_string_direct(c->input, &pkt, &plen)) != 0)
2552 fatal("%s: channel %d: get datagram: %s", __func__,
2553 c->self, ssh_err(r));
2555 * XXX this does tail-drop on the datagram queue which is
2556 * usually suboptimal compared to head-drop. Better to have
2557 * backpressure at read time? (i.e. read + discard)
2559 if (plen > c->remote_window || plen > c->remote_maxpacket) {
2560 debug("channel %d: datagram too big", c->self);
2564 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2565 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2566 (r = sshpkt_put_string(ssh, pkt, plen)) != 0 ||
2567 (r = sshpkt_send(ssh)) != 0) {
2568 fatal("%s: channel %i: datagram: %s", __func__,
2569 c->self, ssh_err(r));
2571 c->remote_window -= plen;
2575 /* Enqueue packet for buffered data. */
2576 if (len > c->remote_window)
2577 len = c->remote_window;
2578 if (len > c->remote_maxpacket)
2579 len = c->remote_maxpacket;
2582 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2583 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2584 (r = sshpkt_put_string(ssh, sshbuf_ptr(c->input), len)) != 0 ||
2585 (r = sshpkt_send(ssh)) != 0) {
2586 fatal("%s: channel %i: data: %s", __func__,
2587 c->self, ssh_err(r));
2589 if ((r = sshbuf_consume(c->input, len)) != 0)
2590 fatal("%s: channel %i: consume: %s", __func__,
2591 c->self, ssh_err(r));
2592 c->remote_window -= len;
2596 * Enqueue data for channels with open c->extended in read mode.
2599 channel_output_poll_extended_read(struct ssh *ssh, Channel *c)
2604 if ((len = sshbuf_len(c->extended)) == 0)
2607 debug2("channel %d: rwin %u elen %zu euse %d", c->self,
2608 c->remote_window, sshbuf_len(c->extended), c->extended_usage);
2609 if (len > c->remote_window)
2610 len = c->remote_window;
2611 if (len > c->remote_maxpacket)
2612 len = c->remote_maxpacket;
2615 if (!c->have_remote_id)
2616 fatal(":%s: channel %d: no remote id", __func__, c->self);
2617 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA)) != 0 ||
2618 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2619 (r = sshpkt_put_u32(ssh, SSH2_EXTENDED_DATA_STDERR)) != 0 ||
2620 (r = sshpkt_put_string(ssh, sshbuf_ptr(c->extended), len)) != 0 ||
2621 (r = sshpkt_send(ssh)) != 0) {
2622 fatal("%s: channel %i: data: %s", __func__,
2623 c->self, ssh_err(r));
2625 if ((r = sshbuf_consume(c->extended, len)) != 0)
2626 fatal("%s: channel %i: consume: %s", __func__,
2627 c->self, ssh_err(r));
2628 c->remote_window -= len;
2629 debug2("channel %d: sent ext data %zu", c->self, len);
2632 /* If there is data to send to the connection, enqueue some of it now. */
2634 channel_output_poll(struct ssh *ssh)
2636 struct ssh_channels *sc = ssh->chanctxt;
2640 for (i = 0; i < sc->channels_alloc; i++) {
2641 c = sc->channels[i];
2646 * We are only interested in channels that can have buffered
2649 if (c->type != SSH_CHANNEL_OPEN)
2651 if ((c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2652 /* XXX is this true? */
2653 debug3("channel %d: will not send data after close",
2658 /* Get the amount of buffered data for this channel. */
2659 if (c->istate == CHAN_INPUT_OPEN ||
2660 c->istate == CHAN_INPUT_WAIT_DRAIN)
2661 channel_output_poll_input_open(ssh, c);
2662 /* Send extended data, i.e. stderr */
2663 if (!(c->flags & CHAN_EOF_SENT) &&
2664 c->extended_usage == CHAN_EXTENDED_READ)
2665 channel_output_poll_extended_read(ssh, c);
2669 /* -- mux proxy support */
2672 * When multiplexing channel messages for mux clients we have to deal
2673 * with downstream messages from the mux client and upstream messages
2674 * from the ssh server:
2675 * 1) Handling downstream messages is straightforward and happens
2676 * in channel_proxy_downstream():
2677 * - We forward all messages (mostly) unmodified to the server.
2678 * - However, in order to route messages from upstream to the correct
2679 * downstream client, we have to replace the channel IDs used by the
2680 * mux clients with a unique channel ID because the mux clients might
2681 * use conflicting channel IDs.
2682 * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
2683 * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
2684 * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
2685 * with the newly allocated channel ID.
2686 * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
2687 * channels and processed by channel_proxy_upstream(). The local channel ID
2688 * is then translated back to the original mux client ID.
2689 * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
2690 * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
2691 * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
2692 * downstream mux client are removed.
2693 * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
2694 * requires more work, because they are not addressed to a specific
2695 * channel. E.g. client_request_forwarded_tcpip() needs to figure
2696 * out whether the request is addressed to the local client or a
2697 * specific downstream client based on the listen-address/port.
2698 * 6) Agent and X11-Forwarding have a similar problem and are currently
2699 * not supported as the matching session/channel cannot be identified
2704 * receive packets from downstream mux clients:
2705 * channel callback fired on read from mux client, creates
2706 * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
2707 * on channel creation.
2710 channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
2713 struct sshbuf *original = NULL, *modified = NULL;
2715 char *ctype = NULL, *listen_host = NULL;
2719 u_int id, remote_id, listen_port;
2721 /* sshbuf_dump(downstream->input, stderr); */
2722 if ((r = sshbuf_get_string_direct(downstream->input, &cp, &have))
2724 error("%s: malformed message: %s", __func__, ssh_err(r));
2728 error("%s: short message", __func__);
2732 /* skip padlen + type */
2735 if (ssh_packet_log_type(type))
2736 debug3("%s: channel %u: down->up: type %u", __func__,
2737 downstream->self, type);
2740 case SSH2_MSG_CHANNEL_OPEN:
2741 if ((original = sshbuf_from(cp, have)) == NULL ||
2742 (modified = sshbuf_new()) == NULL) {
2743 error("%s: alloc", __func__);
2746 if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
2747 (r = sshbuf_get_u32(original, &id)) != 0) {
2748 error("%s: parse error %s", __func__, ssh_err(r));
2751 c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
2752 -1, -1, -1, 0, 0, 0, ctype, 1);
2753 c->mux_ctx = downstream; /* point to mux client */
2754 c->mux_downstream_id = id; /* original downstream id */
2755 if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
2756 (r = sshbuf_put_u32(modified, c->self)) != 0 ||
2757 (r = sshbuf_putb(modified, original)) != 0) {
2758 error("%s: compose error %s", __func__, ssh_err(r));
2759 channel_free(ssh, c);
2763 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2765 * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
2766 * need to parse 'remote_id' instead of 'ctype'.
2768 if ((original = sshbuf_from(cp, have)) == NULL ||
2769 (modified = sshbuf_new()) == NULL) {
2770 error("%s: alloc", __func__);
2773 if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
2774 (r = sshbuf_get_u32(original, &id)) != 0) {
2775 error("%s: parse error %s", __func__, ssh_err(r));
2778 c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
2779 -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
2780 c->mux_ctx = downstream; /* point to mux client */
2781 c->mux_downstream_id = id;
2782 c->remote_id = remote_id;
2783 c->have_remote_id = 1;
2784 if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
2785 (r = sshbuf_put_u32(modified, c->self)) != 0 ||
2786 (r = sshbuf_putb(modified, original)) != 0) {
2787 error("%s: compose error %s", __func__, ssh_err(r));
2788 channel_free(ssh, c);
2792 case SSH2_MSG_GLOBAL_REQUEST:
2793 if ((original = sshbuf_from(cp, have)) == NULL) {
2794 error("%s: alloc", __func__);
2797 if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
2798 error("%s: parse error %s", __func__, ssh_err(r));
2801 if (strcmp(ctype, "tcpip-forward") != 0) {
2802 error("%s: unsupported request %s", __func__, ctype);
2805 if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
2806 (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
2807 (r = sshbuf_get_u32(original, &listen_port)) != 0) {
2808 error("%s: parse error %s", __func__, ssh_err(r));
2811 if (listen_port > 65535) {
2812 error("%s: tcpip-forward for %s: bad port %u",
2813 __func__, listen_host, listen_port);
2816 /* Record that connection to this host/port is permitted. */
2817 permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL, "<mux>", -1,
2818 listen_host, NULL, (int)listen_port, downstream);
2821 case SSH2_MSG_CHANNEL_CLOSE:
2824 remote_id = PEEK_U32(cp);
2825 if ((c = channel_by_remote_id(ssh, remote_id)) != NULL) {
2826 if (c->flags & CHAN_CLOSE_RCVD)
2827 channel_free(ssh, c);
2829 c->flags |= CHAN_CLOSE_SENT;
2834 if ((r = sshpkt_start(ssh, type)) != 0 ||
2835 (r = sshpkt_putb(ssh, modified)) != 0 ||
2836 (r = sshpkt_send(ssh)) != 0) {
2837 error("%s: send %s", __func__, ssh_err(r));
2841 if ((r = sshpkt_start(ssh, type)) != 0 ||
2842 (r = sshpkt_put(ssh, cp, have)) != 0 ||
2843 (r = sshpkt_send(ssh)) != 0) {
2844 error("%s: send %s", __func__, ssh_err(r));
2852 sshbuf_free(original);
2853 sshbuf_free(modified);
2858 * receive packets from upstream server and de-multiplex packets
2859 * to correct downstream:
2860 * implemented as a helper for channel input handlers,
2861 * replaces local (proxy) channel ID with downstream channel ID.
2864 channel_proxy_upstream(Channel *c, int type, u_int32_t seq, struct ssh *ssh)
2866 struct sshbuf *b = NULL;
2867 Channel *downstream;
2868 const u_char *cp = NULL;
2873 * When receiving packets from the peer we need to check whether we
2874 * need to forward the packets to the mux client. In this case we
2875 * restore the original channel id and keep track of CLOSE messages,
2876 * so we can cleanup the channel.
2878 if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
2880 if ((downstream = c->mux_ctx) == NULL)
2883 case SSH2_MSG_CHANNEL_CLOSE:
2884 case SSH2_MSG_CHANNEL_DATA:
2885 case SSH2_MSG_CHANNEL_EOF:
2886 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
2887 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2888 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
2889 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
2890 case SSH2_MSG_CHANNEL_SUCCESS:
2891 case SSH2_MSG_CHANNEL_FAILURE:
2892 case SSH2_MSG_CHANNEL_REQUEST:
2895 debug2("%s: channel %u: unsupported type %u", __func__,
2899 if ((b = sshbuf_new()) == NULL) {
2900 error("%s: alloc reply", __func__);
2903 /* get remaining payload (after id) */
2904 cp = sshpkt_ptr(ssh, &len);
2906 error("%s: no packet", __func__);
2909 /* translate id and send to muxclient */
2910 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
2911 (r = sshbuf_put_u8(b, type)) != 0 ||
2912 (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
2913 (r = sshbuf_put(b, cp, len)) != 0 ||
2914 (r = sshbuf_put_stringb(downstream->output, b)) != 0) {
2915 error("%s: compose for muxclient %s", __func__, ssh_err(r));
2918 /* sshbuf_dump(b, stderr); */
2919 if (ssh_packet_log_type(type))
2920 debug3("%s: channel %u: up->down: type %u", __func__, c->self,
2925 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2926 /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
2927 if (cp && len > 4) {
2928 c->remote_id = PEEK_U32(cp);
2929 c->have_remote_id = 1;
2932 case SSH2_MSG_CHANNEL_CLOSE:
2933 if (c->flags & CHAN_CLOSE_SENT)
2934 channel_free(ssh, c);
2936 c->flags |= CHAN_CLOSE_RCVD;
2943 /* -- protocol input */
2945 /* Parse a channel ID from the current packet */
2947 channel_parse_id(struct ssh *ssh, const char *where, const char *what)
2952 if ((r = sshpkt_get_u32(ssh, &id)) != 0) {
2953 error("%s: parse id: %s", where, ssh_err(r));
2954 ssh_packet_disconnect(ssh, "Invalid %s message", what);
2957 error("%s: bad channel id %u: %s", where, id, ssh_err(r));
2958 ssh_packet_disconnect(ssh, "Invalid %s channel id", what);
2963 /* Lookup a channel from an ID in the current packet */
2965 channel_from_packet_id(struct ssh *ssh, const char *where, const char *what)
2967 int id = channel_parse_id(ssh, where, what);
2970 if ((c = channel_lookup(ssh, id)) == NULL) {
2971 ssh_packet_disconnect(ssh,
2972 "%s packet referred to nonexistent channel %d", what, id);
2978 channel_input_data(int type, u_int32_t seq, struct ssh *ssh)
2981 size_t data_len, win_len;
2982 Channel *c = channel_from_packet_id(ssh, __func__, "data");
2985 if (channel_proxy_upstream(c, type, seq, ssh))
2988 /* Ignore any data for non-open channels (might happen on close) */
2989 if (c->type != SSH_CHANNEL_OPEN &&
2990 c->type != SSH_CHANNEL_RDYNAMIC_OPEN &&
2991 c->type != SSH_CHANNEL_RDYNAMIC_FINISH &&
2992 c->type != SSH_CHANNEL_X11_OPEN)
2996 if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
2997 (r = sshpkt_get_end(ssh)) != 0)
2998 fatal("%s: channel %d: get data: %s", __func__,
2999 c->self, ssh_err(r));
3003 win_len += 4; /* string length header */
3006 * The sending side reduces its window as it sends data, so we
3007 * must 'fake' consumption of the data in order to ensure that window
3008 * updates are sent back. Otherwise the connection might deadlock.
3010 if (c->ostate != CHAN_OUTPUT_OPEN) {
3011 c->local_window -= win_len;
3012 c->local_consumed += win_len;
3016 if (win_len > c->local_maxpacket) {
3017 logit("channel %d: rcvd big packet %zu, maxpack %u",
3018 c->self, win_len, c->local_maxpacket);
3021 if (win_len > c->local_window) {
3022 logit("channel %d: rcvd too much data %zu, win %u",
3023 c->self, win_len, c->local_window);
3026 c->local_window -= win_len;
3029 if ((r = sshbuf_put_string(c->output, data, data_len)) != 0)
3030 fatal("%s: channel %d: append datagram: %s",
3031 __func__, c->self, ssh_err(r));
3032 } else if ((r = sshbuf_put(c->output, data, data_len)) != 0)
3033 fatal("%s: channel %d: append data: %s",
3034 __func__, c->self, ssh_err(r));
3040 channel_input_extended_data(int type, u_int32_t seq, struct ssh *ssh)
3045 Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
3048 if (channel_proxy_upstream(c, type, seq, ssh))
3050 if (c->type != SSH_CHANNEL_OPEN) {
3051 logit("channel %d: ext data for non open", c->self);
3054 if (c->flags & CHAN_EOF_RCVD) {
3055 if (datafellows & SSH_BUG_EXTEOF)
3056 debug("channel %d: accepting ext data after eof",
3059 ssh_packet_disconnect(ssh, "Received extended_data "
3060 "after EOF on channel %d.", c->self);
3063 if ((r = sshpkt_get_u32(ssh, &tcode)) != 0) {
3064 error("%s: parse tcode: %s", __func__, ssh_err(r));
3065 ssh_packet_disconnect(ssh, "Invalid extended_data message");
3068 c->extended_usage != CHAN_EXTENDED_WRITE ||
3069 tcode != SSH2_EXTENDED_DATA_STDERR) {
3070 logit("channel %d: bad ext data", c->self);
3073 if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
3074 (r = sshpkt_get_end(ssh)) != 0) {
3075 error("%s: parse data: %s", __func__, ssh_err(r));
3076 ssh_packet_disconnect(ssh, "Invalid extended_data message");
3079 if (data_len > c->local_window) {
3080 logit("channel %d: rcvd too much extended_data %zu, win %u",
3081 c->self, data_len, c->local_window);
3084 debug2("channel %d: rcvd ext data %zu", c->self, data_len);
3085 /* XXX sshpkt_getb? */
3086 if ((r = sshbuf_put(c->extended, data, data_len)) != 0)
3087 error("%s: append: %s", __func__, ssh_err(r));
3088 c->local_window -= data_len;
3093 channel_input_ieof(int type, u_int32_t seq, struct ssh *ssh)
3095 Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
3098 if ((r = sshpkt_get_end(ssh)) != 0) {
3099 error("%s: parse data: %s", __func__, ssh_err(r));
3100 ssh_packet_disconnect(ssh, "Invalid ieof message");
3103 if (channel_proxy_upstream(c, type, seq, ssh))
3105 chan_rcvd_ieof(ssh, c);
3107 /* XXX force input close */
3108 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
3109 debug("channel %d: FORCE input drain", c->self);
3110 c->istate = CHAN_INPUT_WAIT_DRAIN;
3111 if (sshbuf_len(c->input) == 0)
3112 chan_ibuf_empty(ssh, c);
3118 channel_input_oclose(int type, u_int32_t seq, struct ssh *ssh)
3120 Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
3123 if (channel_proxy_upstream(c, type, seq, ssh))
3125 if ((r = sshpkt_get_end(ssh)) != 0) {
3126 error("%s: parse data: %s", __func__, ssh_err(r));
3127 ssh_packet_disconnect(ssh, "Invalid oclose message");
3129 chan_rcvd_oclose(ssh, c);
3134 channel_input_open_confirmation(int type, u_int32_t seq, struct ssh *ssh)
3136 Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
3137 u_int32_t remote_window, remote_maxpacket;
3140 if (channel_proxy_upstream(c, type, seq, ssh))
3142 if (c->type != SSH_CHANNEL_OPENING)
3143 ssh_packet_disconnect(ssh, "Received open confirmation for "
3144 "non-opening channel %d.", c->self);
3146 * Record the remote channel number and mark that the channel
3149 if ((r = sshpkt_get_u32(ssh, &c->remote_id)) != 0 ||
3150 (r = sshpkt_get_u32(ssh, &remote_window)) != 0 ||
3151 (r = sshpkt_get_u32(ssh, &remote_maxpacket)) != 0 ||
3152 (r = sshpkt_get_end(ssh)) != 0) {
3153 error("%s: window/maxpacket: %s", __func__, ssh_err(r));
3154 ssh_packet_disconnect(ssh, "Invalid open confirmation message");
3157 c->have_remote_id = 1;
3158 c->remote_window = remote_window;
3159 c->remote_maxpacket = remote_maxpacket;
3160 c->type = SSH_CHANNEL_OPEN;
3161 if (c->open_confirm) {
3162 debug2("%s: channel %d: callback start", __func__, c->self);
3163 c->open_confirm(ssh, c->self, 1, c->open_confirm_ctx);
3164 debug2("%s: channel %d: callback done", __func__, c->self);
3166 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
3167 c->remote_window, c->remote_maxpacket);
3172 reason2txt(int reason)
3175 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
3176 return "administratively prohibited";
3177 case SSH2_OPEN_CONNECT_FAILED:
3178 return "connect failed";
3179 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
3180 return "unknown channel type";
3181 case SSH2_OPEN_RESOURCE_SHORTAGE:
3182 return "resource shortage";
3184 return "unknown reason";
3188 channel_input_open_failure(int type, u_int32_t seq, struct ssh *ssh)
3190 Channel *c = channel_from_packet_id(ssh, __func__, "open failure");
3195 if (channel_proxy_upstream(c, type, seq, ssh))
3197 if (c->type != SSH_CHANNEL_OPENING)
3198 ssh_packet_disconnect(ssh, "Received open failure for "
3199 "non-opening channel %d.", c->self);
3200 if ((r = sshpkt_get_u32(ssh, &reason)) != 0) {
3201 error("%s: reason: %s", __func__, ssh_err(r));
3202 ssh_packet_disconnect(ssh, "Invalid open failure message");
3205 if ((r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
3206 (r = sshpkt_get_string_direct(ssh, NULL, NULL)) != 0 ||
3207 (r = sshpkt_get_end(ssh)) != 0) {
3208 error("%s: message/lang: %s", __func__, ssh_err(r));
3209 ssh_packet_disconnect(ssh, "Invalid open failure message");
3211 logit("channel %d: open failed: %s%s%s", c->self,
3212 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
3214 if (c->open_confirm) {
3215 debug2("%s: channel %d: callback start", __func__, c->self);
3216 c->open_confirm(ssh, c->self, 0, c->open_confirm_ctx);
3217 debug2("%s: channel %d: callback done", __func__, c->self);
3219 /* Schedule the channel for cleanup/deletion. */
3220 chan_mark_dead(ssh, c);
3225 channel_input_window_adjust(int type, u_int32_t seq, struct ssh *ssh)
3227 int id = channel_parse_id(ssh, __func__, "window adjust");
3233 if ((c = channel_lookup(ssh, id)) == NULL) {
3234 logit("Received window adjust for non-open channel %d.", id);
3238 if (channel_proxy_upstream(c, type, seq, ssh))
3240 if ((r = sshpkt_get_u32(ssh, &adjust)) != 0 ||
3241 (r = sshpkt_get_end(ssh)) != 0) {
3242 error("%s: adjust: %s", __func__, ssh_err(r));
3243 ssh_packet_disconnect(ssh, "Invalid window adjust message");
3245 debug2("channel %d: rcvd adjust %u", c->self, adjust);
3246 if ((new_rwin = c->remote_window + adjust) < c->remote_window) {
3247 fatal("channel %d: adjust %u overflows remote window %u",
3248 c->self, adjust, c->remote_window);
3250 c->remote_window = new_rwin;
3255 channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
3257 int id = channel_parse_id(ssh, __func__, "status confirm");
3259 struct channel_confirm *cc;
3262 /* Reset keepalive timeout */
3263 ssh_packet_set_alive_timeouts(ssh, 0);
3265 debug2("%s: type %d id %d", __func__, type, id);
3267 if ((c = channel_lookup(ssh, id)) == NULL) {
3268 logit("%s: %d: unknown", __func__, id);
3271 if (channel_proxy_upstream(c, type, seq, ssh))
3273 if ((r = sshpkt_get_end(ssh)) != 0)
3274 ssh_packet_disconnect(ssh, "Invalid status confirm message");
3275 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
3277 cc->cb(ssh, type, c, cc->ctx);
3278 TAILQ_REMOVE(&c->status_confirms, cc, entry);
3279 explicit_bzero(cc, sizeof(*cc));
3284 /* -- tcp forwarding */
3287 channel_set_af(struct ssh *ssh, int af)
3289 ssh->chanctxt->IPv4or6 = af;
3294 * Determine whether or not a port forward listens to loopback, the
3295 * specified address or wildcard. On the client, a specified bind
3296 * address will always override gateway_ports. On the server, a
3297 * gateway_ports of 1 (``yes'') will override the client's specification
3298 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
3299 * will bind to whatever address the client asked for.
3301 * Special-case listen_addrs are:
3303 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
3304 * "" (empty string), "*" -> wildcard v4/v6
3305 * "localhost" -> loopback v4/v6
3306 * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
3309 channel_fwd_bind_addr(struct ssh *ssh, const char *listen_addr, int *wildcardp,
3310 int is_client, struct ForwardOptions *fwd_opts)
3312 const char *addr = NULL;
3315 if (listen_addr == NULL) {
3316 /* No address specified: default to gateway_ports setting */
3317 if (fwd_opts->gateway_ports)
3319 } else if (fwd_opts->gateway_ports || is_client) {
3320 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
3321 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3322 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
3323 (!is_client && fwd_opts->gateway_ports == 1)) {
3326 * Notify client if they requested a specific listen
3327 * address and it was overridden.
3329 if (*listen_addr != '\0' &&
3330 strcmp(listen_addr, "0.0.0.0") != 0 &&
3331 strcmp(listen_addr, "*") != 0) {
3332 ssh_packet_send_debug(ssh,
3333 "Forwarding listen address "
3334 "\"%s\" overridden by server "
3335 "GatewayPorts", listen_addr);
3337 } else if (strcmp(listen_addr, "localhost") != 0 ||
3338 strcmp(listen_addr, "127.0.0.1") == 0 ||
3339 strcmp(listen_addr, "::1") == 0) {
3340 /* Accept localhost address when GatewayPorts=yes */
3343 } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
3344 strcmp(listen_addr, "::1") == 0) {
3346 * If a specific IPv4/IPv6 localhost address has been
3347 * requested then accept it even if gateway_ports is in
3348 * effect. This allows the client to prefer IPv4 or IPv6.
3352 if (wildcardp != NULL)
3353 *wildcardp = wildcard;
3358 channel_setup_fwd_listener_tcpip(struct ssh *ssh, int type,
3359 struct Forward *fwd, int *allocated_listen_port,
3360 struct ForwardOptions *fwd_opts)
3363 int sock, r, success = 0, wildcard = 0, is_client;
3364 struct addrinfo hints, *ai, *aitop;
3365 const char *host, *addr;
3366 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3369 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
3371 if (is_client && fwd->connect_path != NULL) {
3372 host = fwd->connect_path;
3374 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
3375 fwd->listen_host : fwd->connect_host;
3377 error("No forward host name.");
3380 if (strlen(host) >= NI_MAXHOST) {
3381 error("Forward host name too long.");
3386 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
3387 addr = channel_fwd_bind_addr(ssh, fwd->listen_host, &wildcard,
3388 is_client, fwd_opts);
3389 debug3("%s: type %d wildcard %d addr %s", __func__,
3390 type, wildcard, (addr == NULL) ? "NULL" : addr);
3393 * getaddrinfo returns a loopback address if the hostname is
3394 * set to NULL and hints.ai_flags is not AI_PASSIVE
3396 memset(&hints, 0, sizeof(hints));
3397 hints.ai_family = ssh->chanctxt->IPv4or6;
3398 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
3399 hints.ai_socktype = SOCK_STREAM;
3400 snprintf(strport, sizeof strport, "%d", fwd->listen_port);
3401 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
3403 /* This really shouldn't happen */
3404 ssh_packet_disconnect(ssh, "getaddrinfo: fatal error: %s",
3405 ssh_gai_strerror(r));
3407 error("%s: getaddrinfo(%.64s): %s", __func__, addr,
3408 ssh_gai_strerror(r));
3412 if (allocated_listen_port != NULL)
3413 *allocated_listen_port = 0;
3414 for (ai = aitop; ai; ai = ai->ai_next) {
3415 switch (ai->ai_family) {
3417 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
3421 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
3428 * If allocating a port for -R forwards, then use the
3429 * same port for all address families.
3431 if (type == SSH_CHANNEL_RPORT_LISTENER &&
3432 fwd->listen_port == 0 && allocated_listen_port != NULL &&
3433 *allocated_listen_port > 0)
3434 *lport_p = htons(*allocated_listen_port);
3436 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
3437 strport, sizeof(strport),
3438 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3439 error("%s: getnameinfo failed", __func__);
3442 /* Create a port to listen for the host. */
3443 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3445 /* this is no error since kernel may not support ipv6 */
3446 verbose("socket [%s]:%s: %.100s", ntop, strport,
3451 set_reuseaddr(sock);
3452 if (ai->ai_family == AF_INET6)
3453 sock_set_v6only(sock);
3455 debug("Local forwarding listening on %s port %s.",
3458 /* Bind the socket to the address. */
3459 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3461 * address can be in if use ipv6 address is
3465 error("bind [%s]:%s: %.100s",
3466 ntop, strport, strerror(errno));
3468 verbose("bind [%s]:%s: %.100s",
3469 ntop, strport, strerror(errno));
3474 /* Start listening for connections on the socket. */
3475 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3476 error("listen: %.100s", strerror(errno));
3477 error("listen [%s]:%s: %.100s", ntop, strport,
3484 * fwd->listen_port == 0 requests a dynamically allocated port -
3485 * record what we got.
3487 if (type == SSH_CHANNEL_RPORT_LISTENER &&
3488 fwd->listen_port == 0 &&
3489 allocated_listen_port != NULL &&
3490 *allocated_listen_port == 0) {
3491 *allocated_listen_port = get_local_port(sock);
3492 debug("Allocated listen port %d",
3493 *allocated_listen_port);
3496 /* Allocate a channel number for the socket. */
3497 c = channel_new(ssh, "port listener", type, sock, sock, -1,
3498 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3499 0, "port listener", 1);
3500 c->path = xstrdup(host);
3501 c->host_port = fwd->connect_port;
3502 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
3503 if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
3504 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
3505 c->listening_port = *allocated_listen_port;
3507 c->listening_port = fwd->listen_port;
3511 error("%s: cannot listen to port: %d", __func__,
3513 freeaddrinfo(aitop);
3518 channel_setup_fwd_listener_streamlocal(struct ssh *ssh, int type,
3519 struct Forward *fwd, struct ForwardOptions *fwd_opts)
3521 struct sockaddr_un sunaddr;
3528 case SSH_CHANNEL_UNIX_LISTENER:
3529 if (fwd->connect_path != NULL) {
3530 if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
3531 error("Local connecting path too long: %s",
3535 path = fwd->connect_path;
3536 port = PORT_STREAMLOCAL;
3538 if (fwd->connect_host == NULL) {
3539 error("No forward host name.");
3542 if (strlen(fwd->connect_host) >= NI_MAXHOST) {
3543 error("Forward host name too long.");
3546 path = fwd->connect_host;
3547 port = fwd->connect_port;
3550 case SSH_CHANNEL_RUNIX_LISTENER:
3551 path = fwd->listen_path;
3552 port = PORT_STREAMLOCAL;
3555 error("%s: unexpected channel type %d", __func__, type);
3559 if (fwd->listen_path == NULL) {
3560 error("No forward path name.");
3563 if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
3564 error("Local listening path too long: %s", fwd->listen_path);
3568 debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
3570 /* Start a Unix domain listener. */
3571 omask = umask(fwd_opts->streamlocal_bind_mask);
3572 sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
3573 fwd_opts->streamlocal_bind_unlink);
3578 debug("Local forwarding listening on path %s.", fwd->listen_path);
3580 /* Allocate a channel number for the socket. */
3581 c = channel_new(ssh, "unix listener", type, sock, sock, -1,
3582 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3583 0, "unix listener", 1);
3584 c->path = xstrdup(path);
3585 c->host_port = port;
3586 c->listening_port = PORT_STREAMLOCAL;
3587 c->listening_addr = xstrdup(fwd->listen_path);
3592 channel_cancel_rport_listener_tcpip(struct ssh *ssh,
3593 const char *host, u_short port)
3598 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3599 Channel *c = ssh->chanctxt->channels[i];
3600 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3602 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3603 debug2("%s: close channel %d", __func__, i);
3604 channel_free(ssh, c);
3613 channel_cancel_rport_listener_streamlocal(struct ssh *ssh, const char *path)
3618 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3619 Channel *c = ssh->chanctxt->channels[i];
3620 if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3622 if (c->path == NULL)
3624 if (strcmp(c->path, path) == 0) {
3625 debug2("%s: close channel %d", __func__, i);
3626 channel_free(ssh, c);
3635 channel_cancel_rport_listener(struct ssh *ssh, struct Forward *fwd)
3637 if (fwd->listen_path != NULL) {
3638 return channel_cancel_rport_listener_streamlocal(ssh,
3641 return channel_cancel_rport_listener_tcpip(ssh,
3642 fwd->listen_host, fwd->listen_port);
3647 channel_cancel_lport_listener_tcpip(struct ssh *ssh,
3648 const char *lhost, u_short lport, int cport,
3649 struct ForwardOptions *fwd_opts)
3653 const char *addr = channel_fwd_bind_addr(ssh, lhost, NULL, 1, fwd_opts);
3655 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3656 Channel *c = ssh->chanctxt->channels[i];
3657 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
3659 if (c->listening_port != lport)
3661 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
3662 /* skip dynamic forwardings */
3663 if (c->host_port == 0)
3666 if (c->host_port != cport)
3669 if ((c->listening_addr == NULL && addr != NULL) ||
3670 (c->listening_addr != NULL && addr == NULL))
3672 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
3673 debug2("%s: close channel %d", __func__, i);
3674 channel_free(ssh, c);
3683 channel_cancel_lport_listener_streamlocal(struct ssh *ssh, const char *path)
3689 error("%s: no path specified.", __func__);
3693 for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3694 Channel *c = ssh->chanctxt->channels[i];
3695 if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
3697 if (c->listening_addr == NULL)
3699 if (strcmp(c->listening_addr, path) == 0) {
3700 debug2("%s: close channel %d", __func__, i);
3701 channel_free(ssh, c);
3710 channel_cancel_lport_listener(struct ssh *ssh,
3711 struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
3713 if (fwd->listen_path != NULL) {
3714 return channel_cancel_lport_listener_streamlocal(ssh,
3717 return channel_cancel_lport_listener_tcpip(ssh,
3718 fwd->listen_host, fwd->listen_port, cport, fwd_opts);
3722 /* protocol local port fwd, used by ssh */
3724 channel_setup_local_fwd_listener(struct ssh *ssh,
3725 struct Forward *fwd, struct ForwardOptions *fwd_opts)
3727 if (fwd->listen_path != NULL) {
3728 return channel_setup_fwd_listener_streamlocal(ssh,
3729 SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
3731 return channel_setup_fwd_listener_tcpip(ssh,
3732 SSH_CHANNEL_PORT_LISTENER, fwd, NULL, fwd_opts);
3736 /* Matches a remote forwarding permission against a requested forwarding */
3738 remote_open_match(struct permission *allowed_open, struct Forward *fwd)
3743 /* XXX add ACLs for streamlocal */
3744 if (fwd->listen_path != NULL)
3747 if (fwd->listen_host == NULL || allowed_open->listen_host == NULL)
3750 if (allowed_open->listen_port != FWD_PERMIT_ANY_PORT &&
3751 allowed_open->listen_port != fwd->listen_port)
3754 /* Match hostnames case-insensitively */
3755 lhost = xstrdup(fwd->listen_host);
3757 ret = match_pattern(lhost, allowed_open->listen_host);
3763 /* Checks whether a requested remote forwarding is permitted */
3765 check_rfwd_permission(struct ssh *ssh, struct Forward *fwd)
3767 struct ssh_channels *sc = ssh->chanctxt;
3768 struct permission_set *pset = &sc->remote_perms;
3769 u_int i, permit, permit_adm = 1;
3770 struct permission *perm;
3772 /* XXX apply GatewayPorts override before checking? */
3774 permit = pset->all_permitted;
3776 for (i = 0; i < pset->num_permitted_user; i++) {
3777 perm = &pset->permitted_user[i];
3778 if (remote_open_match(perm, fwd)) {
3785 if (pset->num_permitted_admin > 0) {
3787 for (i = 0; i < pset->num_permitted_admin; i++) {
3788 perm = &pset->permitted_admin[i];
3789 if (remote_open_match(perm, fwd)) {
3796 return permit && permit_adm;
3799 /* protocol v2 remote port fwd, used by sshd */
3801 channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
3802 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
3804 if (!check_rfwd_permission(ssh, fwd)) {
3805 ssh_packet_send_debug(ssh, "port forwarding refused");
3808 if (fwd->listen_path != NULL) {
3809 return channel_setup_fwd_listener_streamlocal(ssh,
3810 SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
3812 return channel_setup_fwd_listener_tcpip(ssh,
3813 SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
3819 * Translate the requested rfwd listen host to something usable for
3823 channel_rfwd_bind_host(const char *listen_host)
3825 if (listen_host == NULL) {
3827 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3834 * Initiate forwarding of connections to port "port" on remote host through
3835 * the secure channel to host:port from local side.
3836 * Returns handle (index) for updating the dynamic listen port with
3837 * channel_update_permission().
3840 channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
3842 int r, success = 0, idx = -1;
3843 char *host_to_connect, *listen_host, *listen_path;
3844 int port_to_connect, listen_port;
3846 /* Send the forward request to the remote side. */
3847 if (fwd->listen_path != NULL) {
3848 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3849 (r = sshpkt_put_cstring(ssh,
3850 "streamlocal-forward@openssh.com")) != 0 ||
3851 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
3852 (r = sshpkt_put_cstring(ssh, fwd->listen_path)) != 0 ||
3853 (r = sshpkt_send(ssh)) != 0 ||
3854 (r = ssh_packet_write_wait(ssh)) != 0)
3855 fatal("%s: request streamlocal: %s",
3856 __func__, ssh_err(r));
3858 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3859 (r = sshpkt_put_cstring(ssh, "tcpip-forward")) != 0 ||
3860 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
3861 (r = sshpkt_put_cstring(ssh,
3862 channel_rfwd_bind_host(fwd->listen_host))) != 0 ||
3863 (r = sshpkt_put_u32(ssh, fwd->listen_port)) != 0 ||
3864 (r = sshpkt_send(ssh)) != 0 ||
3865 (r = ssh_packet_write_wait(ssh)) != 0)
3866 fatal("%s: request tcpip-forward: %s",
3867 __func__, ssh_err(r));
3869 /* Assume that server accepts the request */
3872 /* Record that connection to this host/port is permitted. */
3873 host_to_connect = listen_host = listen_path = NULL;
3874 port_to_connect = listen_port = 0;
3875 if (fwd->connect_path != NULL) {
3876 host_to_connect = xstrdup(fwd->connect_path);
3877 port_to_connect = PORT_STREAMLOCAL;
3879 host_to_connect = xstrdup(fwd->connect_host);
3880 port_to_connect = fwd->connect_port;
3882 if (fwd->listen_path != NULL) {
3883 listen_path = xstrdup(fwd->listen_path);
3884 listen_port = PORT_STREAMLOCAL;
3886 if (fwd->listen_host != NULL)
3887 listen_host = xstrdup(fwd->listen_host);
3888 listen_port = fwd->listen_port;
3890 idx = permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL,
3891 host_to_connect, port_to_connect,
3892 listen_host, listen_path, listen_port, NULL);
3898 open_match(struct permission *allowed_open, const char *requestedhost,
3901 if (allowed_open->host_to_connect == NULL)
3903 if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
3904 allowed_open->port_to_connect != requestedport)
3906 if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
3907 strcmp(allowed_open->host_to_connect, requestedhost) != 0)
3913 * Note that in the listen host/port case
3914 * we don't support FWD_PERMIT_ANY_PORT and
3915 * need to translate between the configured-host (listen_host)
3916 * and what we've sent to the remote server (channel_rfwd_bind_host)
3919 open_listen_match_tcpip(struct permission *allowed_open,
3920 const char *requestedhost, u_short requestedport, int translate)
3922 const char *allowed_host;
3924 if (allowed_open->host_to_connect == NULL)
3926 if (allowed_open->listen_port != requestedport)
3928 if (!translate && allowed_open->listen_host == NULL &&
3929 requestedhost == NULL)
3931 allowed_host = translate ?
3932 channel_rfwd_bind_host(allowed_open->listen_host) :
3933 allowed_open->listen_host;
3934 if (allowed_host == NULL || requestedhost == NULL ||
3935 strcmp(allowed_host, requestedhost) != 0)
3941 open_listen_match_streamlocal(struct permission *allowed_open,
3942 const char *requestedpath)
3944 if (allowed_open->host_to_connect == NULL)
3946 if (allowed_open->listen_port != PORT_STREAMLOCAL)
3948 if (allowed_open->listen_path == NULL ||
3949 strcmp(allowed_open->listen_path, requestedpath) != 0)
3955 * Request cancellation of remote forwarding of connection host:port from
3959 channel_request_rforward_cancel_tcpip(struct ssh *ssh,
3960 const char *host, u_short port)
3962 struct ssh_channels *sc = ssh->chanctxt;
3963 struct permission_set *pset = &sc->local_perms;
3966 struct permission *perm;
3968 for (i = 0; i < pset->num_permitted_user; i++) {
3969 perm = &pset->permitted_user[i];
3970 if (open_listen_match_tcpip(perm, host, port, 0))
3975 debug("%s: requested forward not found", __func__);
3978 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3979 (r = sshpkt_put_cstring(ssh, "cancel-tcpip-forward")) != 0 ||
3980 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
3981 (r = sshpkt_put_cstring(ssh, channel_rfwd_bind_host(host))) != 0 ||
3982 (r = sshpkt_put_u32(ssh, port)) != 0 ||
3983 (r = sshpkt_send(ssh)) != 0)
3984 fatal("%s: send cancel: %s", __func__, ssh_err(r));
3986 fwd_perm_clear(perm); /* unregister */
3992 * Request cancellation of remote forwarding of Unix domain socket
3993 * path from local side.
3996 channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
3998 struct ssh_channels *sc = ssh->chanctxt;
3999 struct permission_set *pset = &sc->local_perms;
4002 struct permission *perm;
4004 for (i = 0; i < pset->num_permitted_user; i++) {
4005 perm = &pset->permitted_user[i];
4006 if (open_listen_match_streamlocal(perm, path))
4011 debug("%s: requested forward not found", __func__);
4014 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
4015 (r = sshpkt_put_cstring(ssh,
4016 "cancel-streamlocal-forward@openssh.com")) != 0 ||
4017 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
4018 (r = sshpkt_put_cstring(ssh, path)) != 0 ||
4019 (r = sshpkt_send(ssh)) != 0)
4020 fatal("%s: send cancel: %s", __func__, ssh_err(r));
4022 fwd_perm_clear(perm); /* unregister */
4028 * Request cancellation of remote forwarding of a connection from local side.
4031 channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
4033 if (fwd->listen_path != NULL) {
4034 return channel_request_rforward_cancel_streamlocal(ssh,
4037 return channel_request_rforward_cancel_tcpip(ssh,
4039 fwd->listen_port ? fwd->listen_port : fwd->allocated_port);
4044 * Permits opening to any host/port if permitted_user[] is empty. This is
4045 * usually called by the server, because the user could connect to any port
4046 * anyway, and the server has no way to know but to trust the client anyway.
4049 channel_permit_all(struct ssh *ssh, int where)
4051 struct permission_set *pset = permission_set_get(ssh, where);
4053 if (pset->num_permitted_user == 0)
4054 pset->all_permitted = 1;
4058 * Permit the specified host/port for forwarding.
4061 channel_add_permission(struct ssh *ssh, int who, int where,
4062 char *host, int port)
4064 int local = where == FORWARD_LOCAL;
4065 struct permission_set *pset = permission_set_get(ssh, where);
4067 debug("allow %s forwarding to host %s port %d",
4068 fwd_ident(who, where), host, port);
4070 * Remote forwards set listen_host/port, local forwards set
4071 * host/port_to_connect.
4073 permission_set_add(ssh, who, where,
4074 local ? host : 0, local ? port : 0,
4075 local ? NULL : host, NULL, local ? 0 : port, NULL);
4076 pset->all_permitted = 0;
4080 * Administratively disable forwarding.
4083 channel_disable_admin(struct ssh *ssh, int where)
4085 channel_clear_permission(ssh, FORWARD_ADM, where);
4086 permission_set_add(ssh, FORWARD_ADM, where,
4087 NULL, 0, NULL, NULL, 0, NULL);
4091 * Clear a list of permitted opens.
4094 channel_clear_permission(struct ssh *ssh, int who, int where)
4096 struct permission **permp;
4099 permission_set_get_array(ssh, who, where, &permp, &npermp);
4100 *permp = xrecallocarray(*permp, *npermp, 0, sizeof(**permp));
4105 * Update the listen port for a dynamic remote forward, after
4106 * the actual 'newport' has been allocated. If 'newport' < 0 is
4107 * passed then they entry will be invalidated.
4110 channel_update_permission(struct ssh *ssh, int idx, int newport)
4112 struct permission_set *pset = &ssh->chanctxt->local_perms;
4114 if (idx < 0 || (u_int)idx >= pset->num_permitted_user) {
4115 debug("%s: index out of range: %d num_permitted_user %d",
4116 __func__, idx, pset->num_permitted_user);
4119 debug("%s allowed port %d for forwarding to host %s port %d",
4120 newport > 0 ? "Updating" : "Removing",
4122 pset->permitted_user[idx].host_to_connect,
4123 pset->permitted_user[idx].port_to_connect);
4125 fwd_perm_clear(&pset->permitted_user[idx]);
4127 pset->permitted_user[idx].listen_port =
4128 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
4132 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
4134 permitopen_port(const char *p)
4138 if (strcmp(p, "*") == 0)
4139 return FWD_PERMIT_ANY_PORT;
4140 if ((port = a2port(p)) > 0)
4145 /* Try to start non-blocking connect to next host in cctx list */
4147 connect_next(struct channel_connect *cctx)
4149 int sock, saved_errno;
4150 struct sockaddr_un *sunaddr;
4151 char ntop[NI_MAXHOST];
4152 char strport[MAXIMUM(NI_MAXSERV, sizeof(sunaddr->sun_path))];
4154 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
4155 switch (cctx->ai->ai_family) {
4157 /* unix:pathname instead of host:port */
4158 sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
4159 strlcpy(ntop, "unix", sizeof(ntop));
4160 strlcpy(strport, sunaddr->sun_path, sizeof(strport));
4164 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
4165 ntop, sizeof(ntop), strport, sizeof(strport),
4166 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
4167 error("connect_next: getnameinfo failed");
4174 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
4175 cctx->ai->ai_protocol)) == -1) {
4176 if (cctx->ai->ai_next == NULL)
4177 error("socket: %.100s", strerror(errno));
4179 verbose("socket: %.100s", strerror(errno));
4182 if (set_nonblock(sock) == -1)
4183 fatal("%s: set_nonblock(%d)", __func__, sock);
4184 if (connect(sock, cctx->ai->ai_addr,
4185 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
4186 debug("connect_next: host %.100s ([%.100s]:%s): "
4187 "%.100s", cctx->host, ntop, strport,
4189 saved_errno = errno;
4191 errno = saved_errno;
4192 continue; /* fail -- try next */
4194 if (cctx->ai->ai_family != AF_UNIX)
4196 debug("connect_next: host %.100s ([%.100s]:%s) "
4197 "in progress, fd=%d", cctx->host, ntop, strport, sock);
4198 cctx->ai = cctx->ai->ai_next;
4205 channel_connect_ctx_free(struct channel_connect *cctx)
4209 if (cctx->aitop->ai_family == AF_UNIX)
4212 freeaddrinfo(cctx->aitop);
4214 memset(cctx, 0, sizeof(*cctx));
4218 * Return connecting socket to remote host:port or local socket path,
4219 * passing back the failure reason if appropriate.
4222 connect_to_helper(struct ssh *ssh, const char *name, int port, int socktype,
4223 char *ctype, char *rname, struct channel_connect *cctx,
4224 int *reason, const char **errmsg)
4226 struct addrinfo hints;
4229 char strport[NI_MAXSERV];
4231 if (port == PORT_STREAMLOCAL) {
4232 struct sockaddr_un *sunaddr;
4233 struct addrinfo *ai;
4235 if (strlen(name) > sizeof(sunaddr->sun_path)) {
4236 error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
4241 * Fake up a struct addrinfo for AF_UNIX connections.
4242 * channel_connect_ctx_free() must check ai_family
4243 * and use free() not freeaddirinfo() for AF_UNIX.
4245 ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
4246 memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
4247 ai->ai_addr = (struct sockaddr *)(ai + 1);
4248 ai->ai_addrlen = sizeof(*sunaddr);
4249 ai->ai_family = AF_UNIX;
4250 ai->ai_socktype = socktype;
4251 ai->ai_protocol = PF_UNSPEC;
4252 sunaddr = (struct sockaddr_un *)ai->ai_addr;
4253 sunaddr->sun_family = AF_UNIX;
4254 strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
4257 memset(&hints, 0, sizeof(hints));
4258 hints.ai_family = ssh->chanctxt->IPv4or6;
4259 hints.ai_socktype = socktype;
4260 snprintf(strport, sizeof strport, "%d", port);
4261 if ((gaierr = getaddrinfo(name, strport, &hints, &cctx->aitop))
4264 *errmsg = ssh_gai_strerror(gaierr);
4266 *reason = SSH2_OPEN_CONNECT_FAILED;
4267 error("connect_to %.100s: unknown host (%s)", name,
4268 ssh_gai_strerror(gaierr));
4273 cctx->host = xstrdup(name);
4275 cctx->ai = cctx->aitop;
4277 if ((sock = connect_next(cctx)) == -1) {
4278 error("connect to %.100s port %d failed: %s",
4279 name, port, strerror(errno));
4286 /* Return CONNECTING channel to remote host:port or local socket path */
4288 connect_to(struct ssh *ssh, const char *host, int port,
4289 char *ctype, char *rname)
4291 struct channel_connect cctx;
4295 memset(&cctx, 0, sizeof(cctx));
4296 sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
4299 channel_connect_ctx_free(&cctx);
4302 c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
4303 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4304 c->host_port = port;
4305 c->path = xstrdup(host);
4306 c->connect_ctx = cctx;
4312 * returns either the newly connected channel or the downstream channel
4313 * that needs to deal with this connection.
4316 channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
4317 u_short listen_port, char *ctype, char *rname)
4319 struct ssh_channels *sc = ssh->chanctxt;
4320 struct permission_set *pset = &sc->local_perms;
4322 struct permission *perm;
4324 for (i = 0; i < pset->num_permitted_user; i++) {
4325 perm = &pset->permitted_user[i];
4326 if (open_listen_match_tcpip(perm,
4327 listen_host, listen_port, 1)) {
4328 if (perm->downstream)
4329 return perm->downstream;
4330 if (perm->port_to_connect == 0)
4331 return rdynamic_connect_prepare(ssh,
4333 return connect_to(ssh,
4334 perm->host_to_connect, perm->port_to_connect,
4338 error("WARNING: Server requests forwarding for unknown listen_port %d",
4344 channel_connect_by_listen_path(struct ssh *ssh, const char *path,
4345 char *ctype, char *rname)
4347 struct ssh_channels *sc = ssh->chanctxt;
4348 struct permission_set *pset = &sc->local_perms;
4350 struct permission *perm;
4352 for (i = 0; i < pset->num_permitted_user; i++) {
4353 perm = &pset->permitted_user[i];
4354 if (open_listen_match_streamlocal(perm, path)) {
4355 return connect_to(ssh,
4356 perm->host_to_connect, perm->port_to_connect,
4360 error("WARNING: Server requests forwarding for unknown path %.100s",
4365 /* Check if connecting to that port is permitted and connect. */
4367 channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
4368 char *ctype, char *rname, int *reason, const char **errmsg)
4370 struct ssh_channels *sc = ssh->chanctxt;
4371 struct permission_set *pset = &sc->local_perms;
4372 struct channel_connect cctx;
4374 u_int i, permit, permit_adm = 1;
4376 struct permission *perm;
4378 permit = pset->all_permitted;
4380 for (i = 0; i < pset->num_permitted_user; i++) {
4381 perm = &pset->permitted_user[i];
4382 if (open_match(perm, host, port)) {
4389 if (pset->num_permitted_admin > 0) {
4391 for (i = 0; i < pset->num_permitted_admin; i++) {
4392 perm = &pset->permitted_admin[i];
4393 if (open_match(perm, host, port)) {
4400 if (!permit || !permit_adm) {
4401 logit("Received request to connect to host %.100s port %d, "
4402 "but the request was denied.", host, port);
4404 *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
4408 memset(&cctx, 0, sizeof(cctx));
4409 sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
4410 &cctx, reason, errmsg);
4412 channel_connect_ctx_free(&cctx);
4416 c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
4417 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4418 c->host_port = port;
4419 c->path = xstrdup(host);
4420 c->connect_ctx = cctx;
4425 /* Check if connecting to that path is permitted and connect. */
4427 channel_connect_to_path(struct ssh *ssh, const char *path,
4428 char *ctype, char *rname)
4430 struct ssh_channels *sc = ssh->chanctxt;
4431 struct permission_set *pset = &sc->local_perms;
4432 u_int i, permit, permit_adm = 1;
4433 struct permission *perm;
4435 permit = pset->all_permitted;
4437 for (i = 0; i < pset->num_permitted_user; i++) {
4438 perm = &pset->permitted_user[i];
4439 if (open_match(perm, path, PORT_STREAMLOCAL)) {
4446 if (pset->num_permitted_admin > 0) {
4448 for (i = 0; i < pset->num_permitted_admin; i++) {
4449 perm = &pset->permitted_admin[i];
4450 if (open_match(perm, path, PORT_STREAMLOCAL)) {
4457 if (!permit || !permit_adm) {
4458 logit("Received request to connect to path %.100s, "
4459 "but the request was denied.", path);
4462 return connect_to(ssh, path, PORT_STREAMLOCAL, ctype, rname);
4466 channel_send_window_changes(struct ssh *ssh)
4468 struct ssh_channels *sc = ssh->chanctxt;
4473 for (i = 0; i < sc->channels_alloc; i++) {
4474 if (sc->channels[i] == NULL || !sc->channels[i]->client_tty ||
4475 sc->channels[i]->type != SSH_CHANNEL_OPEN)
4477 if (ioctl(sc->channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
4479 channel_request_start(ssh, i, "window-change", 0);
4480 if ((r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
4481 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
4482 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
4483 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0 ||
4484 (r = sshpkt_send(ssh)) != 0)
4485 fatal("%s: channel %u: send window-change: %s",
4486 __func__, i, ssh_err(r));
4490 /* Return RDYNAMIC_OPEN channel: channel allows SOCKS, but is not connected */
4492 rdynamic_connect_prepare(struct ssh *ssh, char *ctype, char *rname)
4497 c = channel_new(ssh, ctype, SSH_CHANNEL_RDYNAMIC_OPEN, -1, -1, -1,
4498 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4503 * We need to open the channel before we have a FD,
4504 * so that we can get SOCKS header from peer.
4506 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
4507 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
4508 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
4509 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
4510 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
4511 fatal("%s: channel %i: confirm: %s", __func__,
4512 c->self, ssh_err(r));
4517 /* Return CONNECTING socket to remote host:port or local socket path */
4519 rdynamic_connect_finish(struct ssh *ssh, Channel *c)
4521 struct channel_connect cctx;
4524 memset(&cctx, 0, sizeof(cctx));
4525 sock = connect_to_helper(ssh, c->path, c->host_port, SOCK_STREAM, NULL,
4526 NULL, &cctx, NULL, NULL);
4528 channel_connect_ctx_free(&cctx);
4530 /* similar to SSH_CHANNEL_CONNECTING but we've already sent the open */
4531 c->type = SSH_CHANNEL_RDYNAMIC_FINISH;
4532 c->connect_ctx = cctx;
4533 channel_register_fds(ssh, c, sock, sock, -1, 0, 1, 0);
4538 /* -- X11 forwarding */
4541 * Creates an internet domain socket for listening for X11 connections.
4542 * Returns 0 and a suitable display number for the DISPLAY variable
4543 * stored in display_numberp , or -1 if an error occurs.
4546 x11_create_display_inet(struct ssh *ssh, int x11_display_offset,
4547 int x11_use_localhost, int single_connection,
4548 u_int *display_numberp, int **chanids)
4551 int display_number, sock;
4553 struct addrinfo hints, *ai, *aitop;
4554 char strport[NI_MAXSERV];
4555 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
4557 if (chanids == NULL)
4560 for (display_number = x11_display_offset;
4561 display_number < MAX_DISPLAYS;
4563 port = 6000 + display_number;
4564 memset(&hints, 0, sizeof(hints));
4565 hints.ai_family = ssh->chanctxt->IPv4or6;
4566 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
4567 hints.ai_socktype = SOCK_STREAM;
4568 snprintf(strport, sizeof strport, "%d", port);
4569 if ((gaierr = getaddrinfo(NULL, strport,
4570 &hints, &aitop)) != 0) {
4571 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
4574 for (ai = aitop; ai; ai = ai->ai_next) {
4575 if (ai->ai_family != AF_INET &&
4576 ai->ai_family != AF_INET6)
4578 sock = socket(ai->ai_family, ai->ai_socktype,
4581 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
4583 && (errno != EPFNOSUPPORT)
4586 error("socket: %.100s", strerror(errno));
4587 freeaddrinfo(aitop);
4590 debug("x11_create_display_inet: Socket family %d not supported",
4595 if (ai->ai_family == AF_INET6)
4596 sock_set_v6only(sock);
4597 if (x11_use_localhost)
4598 set_reuseaddr(sock);
4599 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4600 debug2("%s: bind port %d: %.100s", __func__,
4601 port, strerror(errno));
4603 for (n = 0; n < num_socks; n++)
4608 socks[num_socks++] = sock;
4609 if (num_socks == NUM_SOCKS)
4612 freeaddrinfo(aitop);
4616 if (display_number >= MAX_DISPLAYS) {
4617 error("Failed to allocate internet-domain X11 display socket.");
4620 /* Start listening for connections on the socket. */
4621 for (n = 0; n < num_socks; n++) {
4623 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
4624 error("listen: %.100s", strerror(errno));
4630 /* Allocate a channel for each socket. */
4631 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
4632 for (n = 0; n < num_socks; n++) {
4634 nc = channel_new(ssh, "x11 listener",
4635 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
4636 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
4637 0, "X11 inet listener", 1);
4638 nc->single_connection = single_connection;
4639 (*chanids)[n] = nc->self;
4643 /* Return the display number for the DISPLAY environment variable. */
4644 *display_numberp = display_number;
4649 connect_local_xsocket_path(const char *pathname)
4652 struct sockaddr_un addr;
4654 sock = socket(AF_UNIX, SOCK_STREAM, 0);
4656 error("socket: %.100s", strerror(errno));
4657 memset(&addr, 0, sizeof(addr));
4658 addr.sun_family = AF_UNIX;
4659 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
4660 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
4663 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
4668 connect_local_xsocket(u_int dnr)
4671 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
4672 return connect_local_xsocket_path(buf);
4677 is_path_to_xsocket(const char *display, char *path, size_t pathlen)
4681 if (strlcpy(path, display, pathlen) >= pathlen) {
4682 error("%s: display path too long", __func__);
4685 if (display[0] != '/')
4687 if (stat(path, &sbuf) == 0) {
4690 char *dot = strrchr(path, '.');
4693 if (stat(path, &sbuf) == 0) {
4703 x11_connect_display(struct ssh *ssh)
4705 u_int display_number;
4706 const char *display;
4707 char buf[1024], *cp;
4708 struct addrinfo hints, *ai, *aitop;
4709 char strport[NI_MAXSERV];
4710 int gaierr, sock = 0;
4712 /* Try to open a socket for the local X server. */
4713 display = getenv("DISPLAY");
4715 error("DISPLAY not set.");
4719 * Now we decode the value of the DISPLAY variable and make a
4720 * connection to the real X server.
4724 /* Check if display is a path to a socket (as set by launchd). */
4726 char path[PATH_MAX];
4728 if (is_path_to_xsocket(display, path, sizeof(path))) {
4729 debug("x11_connect_display: $DISPLAY is launchd");
4731 /* Create a socket. */
4732 sock = connect_local_xsocket_path(path);
4736 /* OK, we now have a connection to the display. */
4742 * Check if it is a unix domain socket. Unix domain displays are in
4743 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
4745 if (strncmp(display, "unix:", 5) == 0 ||
4746 display[0] == ':') {
4747 /* Connect to the unix domain socket. */
4748 if (sscanf(strrchr(display, ':') + 1, "%u",
4749 &display_number) != 1) {
4750 error("Could not parse display number from DISPLAY: "
4754 /* Create a socket. */
4755 sock = connect_local_xsocket(display_number);
4759 /* OK, we now have a connection to the display. */
4763 * Connect to an inet socket. The DISPLAY value is supposedly
4764 * hostname:d[.s], where hostname may also be numeric IP address.
4766 strlcpy(buf, display, sizeof(buf));
4767 cp = strchr(buf, ':');
4769 error("Could not find ':' in DISPLAY: %.100s", display);
4774 * buf now contains the host name. But first we parse the
4777 if (sscanf(cp + 1, "%u", &display_number) != 1) {
4778 error("Could not parse display number from DISPLAY: %.100s",
4783 /* Look up the host address */
4784 memset(&hints, 0, sizeof(hints));
4785 hints.ai_family = ssh->chanctxt->IPv4or6;
4786 hints.ai_socktype = SOCK_STREAM;
4787 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
4788 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
4789 error("%.100s: unknown host. (%s)", buf,
4790 ssh_gai_strerror(gaierr));
4793 for (ai = aitop; ai; ai = ai->ai_next) {
4794 /* Create a socket. */
4795 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
4797 debug2("socket: %.100s", strerror(errno));
4800 /* Connect it to the display. */
4801 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4802 debug2("connect %.100s port %u: %.100s", buf,
4803 6000 + display_number, strerror(errno));
4810 freeaddrinfo(aitop);
4812 error("connect %.100s port %u: %.100s", buf,
4813 6000 + display_number, strerror(errno));
4821 * Requests forwarding of X11 connections, generates fake authentication
4822 * data, and enables authentication spoofing.
4823 * This should be called in the client only.
4826 x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id,
4827 const char *disp, const char *proto, const char *data, int want_reply)
4829 struct ssh_channels *sc = ssh->chanctxt;
4830 u_int data_len = (u_int) strlen(data) / 2;
4834 int r, screen_number;
4836 if (sc->x11_saved_display == NULL)
4837 sc->x11_saved_display = xstrdup(disp);
4838 else if (strcmp(disp, sc->x11_saved_display) != 0) {
4839 error("x11_request_forwarding_with_spoofing: different "
4840 "$DISPLAY already forwarded");
4844 cp = strchr(disp, ':');
4846 cp = strchr(cp, '.');
4848 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
4852 if (sc->x11_saved_proto == NULL) {
4853 /* Save protocol name. */
4854 sc->x11_saved_proto = xstrdup(proto);
4856 /* Extract real authentication data. */
4857 sc->x11_saved_data = xmalloc(data_len);
4858 for (i = 0; i < data_len; i++) {
4859 if (sscanf(data + 2 * i, "%2x", &value) != 1)
4860 fatal("x11_request_forwarding: bad "
4861 "authentication data: %.100s", data);
4862 sc->x11_saved_data[i] = value;
4864 sc->x11_saved_data_len = data_len;
4866 /* Generate fake data of the same length. */
4867 sc->x11_fake_data = xmalloc(data_len);
4868 arc4random_buf(sc->x11_fake_data, data_len);
4869 sc->x11_fake_data_len = data_len;
4872 /* Convert the fake data into hex. */
4873 new_data = tohex(sc->x11_fake_data, data_len);
4875 /* Send the request packet. */
4876 channel_request_start(ssh, client_session_id, "x11-req", want_reply);
4877 if ((r = sshpkt_put_u8(ssh, 0)) != 0 || /* bool: single connection */
4878 (r = sshpkt_put_cstring(ssh, proto)) != 0 ||
4879 (r = sshpkt_put_cstring(ssh, new_data)) != 0 ||
4880 (r = sshpkt_put_u32(ssh, screen_number)) != 0 ||
4881 (r = sshpkt_send(ssh)) != 0 ||
4882 (r = ssh_packet_write_wait(ssh)) != 0)
4883 fatal("%s: send x11-req: %s", __func__, ssh_err(r));