1 /* $OpenBSD: channels.c,v 1.336 2014/07/15 15:54:14 millert 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>
66 #include "openbsd-compat/sys-queue.h"
80 #include "pathnames.h"
85 * Pointer to an array containing all allocated channels. The array is
86 * dynamically extended as needed.
88 static Channel **channels = NULL;
91 * Size of the channel array. All slots of the array must always be
92 * initialized (at least the type field); unused slots set to NULL
94 static u_int channels_alloc = 0;
97 * Maximum file descriptor value used in any of the channels. This is
98 * updated in channel_new.
100 static int channel_max_fd = 0;
103 /* -- tcp forwarding */
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. */
122 /* List of all permitted host/port pairs to connect by the user. */
123 static ForwardPermission *permitted_opens = NULL;
125 /* List of all permitted host/port pairs to connect by the admin. */
126 static ForwardPermission *permitted_adm_opens = NULL;
128 /* Number of permitted host/port pairs in the array permitted by the user. */
129 static int num_permitted_opens = 0;
131 /* Number of permitted host/port pair in the array permitted by the admin. */
132 static int num_adm_permitted_opens = 0;
134 /* special-case port number meaning allow any port */
135 #define FWD_PERMIT_ANY_PORT 0
138 * If this is true, all opens are permitted. This is the case on the server
139 * on which we have to trust the client anyway, and the user could do
140 * anything after logging in anyway.
142 static int all_opens_permitted = 0;
145 /* -- X11 forwarding */
147 /* Maximum number of fake X11 displays to try. */
148 #define MAX_DISPLAYS 1000
150 /* Saved X11 local (client) display. */
151 static char *x11_saved_display = NULL;
153 /* Saved X11 authentication protocol name. */
154 static char *x11_saved_proto = NULL;
156 /* Saved X11 authentication data. This is the real data. */
157 static char *x11_saved_data = NULL;
158 static u_int x11_saved_data_len = 0;
161 * Fake X11 authentication data. This is what the server will be sending us;
162 * we should replace any occurrences of this by the real data.
164 static u_char *x11_fake_data = NULL;
165 static u_int x11_fake_data_len;
168 /* -- agent forwarding */
172 /* AF_UNSPEC or AF_INET or AF_INET6 */
173 static int IPv4or6 = AF_UNSPEC;
176 static void port_open_helper(Channel *c, char *rtype);
178 /* non-blocking connect helpers */
179 static int connect_next(struct channel_connect *);
180 static void channel_connect_ctx_free(struct channel_connect *);
182 /* -- channel core */
185 channel_by_id(int id)
189 if (id < 0 || (u_int)id >= channels_alloc) {
190 logit("channel_by_id: %d: bad id", id);
195 logit("channel_by_id: %d: bad id: channel free", id);
202 * Returns the channel if it is allowed to receive protocol messages.
203 * Private channels, like listening sockets, may not receive messages.
206 channel_lookup(int id)
210 if ((c = channel_by_id(id)) == NULL)
214 case SSH_CHANNEL_X11_OPEN:
215 case SSH_CHANNEL_LARVAL:
216 case SSH_CHANNEL_CONNECTING:
217 case SSH_CHANNEL_DYNAMIC:
218 case SSH_CHANNEL_OPENING:
219 case SSH_CHANNEL_OPEN:
220 case SSH_CHANNEL_INPUT_DRAINING:
221 case SSH_CHANNEL_OUTPUT_DRAINING:
222 case SSH_CHANNEL_ABANDONED:
225 logit("Non-public channel %d, type %d.", id, c->type);
230 * Register filedescriptors for a channel, used when allocating a channel or
231 * when the channel consumer/producer is ready, e.g. shell exec'd
234 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
235 int extusage, int nonblock, int is_tty)
237 /* Update the maximum file descriptor value. */
238 channel_max_fd = MAX(channel_max_fd, rfd);
239 channel_max_fd = MAX(channel_max_fd, wfd);
240 channel_max_fd = MAX(channel_max_fd, efd);
243 fcntl(rfd, F_SETFD, FD_CLOEXEC);
244 if (wfd != -1 && wfd != rfd)
245 fcntl(wfd, F_SETFD, FD_CLOEXEC);
246 if (efd != -1 && efd != rfd && efd != wfd)
247 fcntl(efd, F_SETFD, FD_CLOEXEC);
251 c->sock = (rfd == wfd) ? rfd : -1;
253 c->extended_usage = extusage;
255 if ((c->isatty = is_tty) != 0)
256 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
258 /* XXX: Later AIX versions can't push as much data to tty */
259 c->wfd_isatty = is_tty || isatty(c->wfd);
262 /* enable nonblocking mode */
274 * Allocate a new channel object and set its type and socket. This will cause
275 * remote_name to be freed.
278 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
279 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
285 /* Do initial allocation if this is the first call. */
286 if (channels_alloc == 0) {
288 channels = xcalloc(channels_alloc, sizeof(Channel *));
289 for (i = 0; i < channels_alloc; i++)
292 /* Try to find a free slot where to put the new channel. */
293 for (found = -1, i = 0; i < channels_alloc; i++)
294 if (channels[i] == NULL) {
295 /* Found a free slot. */
300 /* There are no free slots. Take last+1 slot and expand the array. */
301 found = channels_alloc;
302 if (channels_alloc > 10000)
303 fatal("channel_new: internal error: channels_alloc %d "
304 "too big.", channels_alloc);
305 channels = xrealloc(channels, channels_alloc + 10,
307 channels_alloc += 10;
308 debug2("channel: expanding %d", channels_alloc);
309 for (i = found; i < channels_alloc; i++)
312 /* Initialize and return new channel. */
313 c = channels[found] = xcalloc(1, sizeof(Channel));
314 buffer_init(&c->input);
315 buffer_init(&c->output);
316 buffer_init(&c->extended);
318 c->listening_addr = NULL;
319 c->listening_port = 0;
320 c->ostate = CHAN_OUTPUT_OPEN;
321 c->istate = CHAN_INPUT_OPEN;
323 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
328 c->local_window = window;
329 c->local_window_max = window;
330 c->local_consumed = 0;
331 c->local_maxpacket = maxpack;
333 c->remote_name = xstrdup(remote_name);
334 c->remote_window = 0;
335 c->remote_maxpacket = 0;
337 c->single_connection = 0;
338 c->detach_user = NULL;
340 c->open_confirm = NULL;
341 c->open_confirm_ctx = NULL;
342 c->input_filter = NULL;
343 c->output_filter = NULL;
344 c->filter_ctx = NULL;
345 c->filter_cleanup = NULL;
350 c->delayed = 1; /* prevent call to channel_post handler */
351 TAILQ_INIT(&c->status_confirms);
352 debug("channel %d: new [%s]", found, remote_name);
357 channel_find_maxfd(void)
363 for (i = 0; i < channels_alloc; i++) {
366 max = MAX(max, c->rfd);
367 max = MAX(max, c->wfd);
368 max = MAX(max, c->efd);
375 channel_close_fd(int *fdp)
377 int ret = 0, fd = *fdp;
382 if (fd == channel_max_fd)
383 channel_max_fd = channel_find_maxfd();
388 /* Close all channel fd/socket. */
390 channel_close_fds(Channel *c)
392 channel_close_fd(&c->sock);
393 channel_close_fd(&c->rfd);
394 channel_close_fd(&c->wfd);
395 channel_close_fd(&c->efd);
398 /* Free the channel and close its fd/socket. */
400 channel_free(Channel *c)
404 struct channel_confirm *cc;
406 for (n = 0, i = 0; i < channels_alloc; i++)
409 debug("channel %d: free: %s, nchannels %u", c->self,
410 c->remote_name ? c->remote_name : "???", n);
412 s = channel_open_message();
413 debug3("channel %d: status: %s", c->self, s);
417 shutdown(c->sock, SHUT_RDWR);
418 channel_close_fds(c);
419 buffer_free(&c->input);
420 buffer_free(&c->output);
421 buffer_free(&c->extended);
422 free(c->remote_name);
423 c->remote_name = NULL;
426 free(c->listening_addr);
427 c->listening_addr = NULL;
428 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
429 if (cc->abandon_cb != NULL)
430 cc->abandon_cb(c, cc->ctx);
431 TAILQ_REMOVE(&c->status_confirms, cc, entry);
432 explicit_bzero(cc, sizeof(*cc));
435 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
436 c->filter_cleanup(c->self, c->filter_ctx);
437 channels[c->self] = NULL;
442 channel_free_all(void)
446 for (i = 0; i < channels_alloc; i++)
447 if (channels[i] != NULL)
448 channel_free(channels[i]);
452 * Closes the sockets/fds of all channels. This is used to close extra file
453 * descriptors after a fork.
456 channel_close_all(void)
460 for (i = 0; i < channels_alloc; i++)
461 if (channels[i] != NULL)
462 channel_close_fds(channels[i]);
466 * Stop listening to channels.
469 channel_stop_listening(void)
474 for (i = 0; i < channels_alloc; i++) {
478 case SSH_CHANNEL_AUTH_SOCKET:
479 case SSH_CHANNEL_PORT_LISTENER:
480 case SSH_CHANNEL_RPORT_LISTENER:
481 case SSH_CHANNEL_X11_LISTENER:
482 case SSH_CHANNEL_UNIX_LISTENER:
483 case SSH_CHANNEL_RUNIX_LISTENER:
484 channel_close_fd(&c->sock);
493 * Returns true if no channel has too much buffered data, and false if one or
494 * more channel is overfull.
497 channel_not_very_much_buffered_data(void)
502 for (i = 0; i < channels_alloc; i++) {
504 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
507 buffer_len(&c->input) > packet_get_maxsize()) {
508 debug2("channel %d: big input buffer %d",
509 c->self, buffer_len(&c->input));
513 if (buffer_len(&c->output) > packet_get_maxsize()) {
514 debug2("channel %d: big output buffer %u > %u",
515 c->self, buffer_len(&c->output),
516 packet_get_maxsize());
524 /* Returns true if any channel is still open. */
526 channel_still_open(void)
531 for (i = 0; i < channels_alloc; i++) {
536 case SSH_CHANNEL_X11_LISTENER:
537 case SSH_CHANNEL_PORT_LISTENER:
538 case SSH_CHANNEL_RPORT_LISTENER:
539 case SSH_CHANNEL_MUX_LISTENER:
540 case SSH_CHANNEL_CLOSED:
541 case SSH_CHANNEL_AUTH_SOCKET:
542 case SSH_CHANNEL_DYNAMIC:
543 case SSH_CHANNEL_CONNECTING:
544 case SSH_CHANNEL_ZOMBIE:
545 case SSH_CHANNEL_ABANDONED:
546 case SSH_CHANNEL_UNIX_LISTENER:
547 case SSH_CHANNEL_RUNIX_LISTENER:
549 case SSH_CHANNEL_LARVAL:
551 fatal("cannot happen: SSH_CHANNEL_LARVAL");
553 case SSH_CHANNEL_OPENING:
554 case SSH_CHANNEL_OPEN:
555 case SSH_CHANNEL_X11_OPEN:
556 case SSH_CHANNEL_MUX_CLIENT:
558 case SSH_CHANNEL_INPUT_DRAINING:
559 case SSH_CHANNEL_OUTPUT_DRAINING:
561 fatal("cannot happen: OUT_DRAIN");
564 fatal("channel_still_open: bad channel type %d", c->type);
571 /* Returns the id of an open channel suitable for keepaliving */
573 channel_find_open(void)
578 for (i = 0; i < channels_alloc; i++) {
580 if (c == NULL || c->remote_id < 0)
583 case SSH_CHANNEL_CLOSED:
584 case SSH_CHANNEL_DYNAMIC:
585 case SSH_CHANNEL_X11_LISTENER:
586 case SSH_CHANNEL_PORT_LISTENER:
587 case SSH_CHANNEL_RPORT_LISTENER:
588 case SSH_CHANNEL_MUX_LISTENER:
589 case SSH_CHANNEL_MUX_CLIENT:
590 case SSH_CHANNEL_OPENING:
591 case SSH_CHANNEL_CONNECTING:
592 case SSH_CHANNEL_ZOMBIE:
593 case SSH_CHANNEL_ABANDONED:
594 case SSH_CHANNEL_UNIX_LISTENER:
595 case SSH_CHANNEL_RUNIX_LISTENER:
597 case SSH_CHANNEL_LARVAL:
598 case SSH_CHANNEL_AUTH_SOCKET:
599 case SSH_CHANNEL_OPEN:
600 case SSH_CHANNEL_X11_OPEN:
602 case SSH_CHANNEL_INPUT_DRAINING:
603 case SSH_CHANNEL_OUTPUT_DRAINING:
605 fatal("cannot happen: OUT_DRAIN");
608 fatal("channel_find_open: bad channel type %d", c->type);
617 * Returns a message describing the currently open forwarded connections,
618 * suitable for sending to the client. The message contains crlf pairs for
622 channel_open_message(void)
629 buffer_init(&buffer);
630 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
631 buffer_append(&buffer, buf, strlen(buf));
632 for (i = 0; i < channels_alloc; i++) {
637 case SSH_CHANNEL_X11_LISTENER:
638 case SSH_CHANNEL_PORT_LISTENER:
639 case SSH_CHANNEL_RPORT_LISTENER:
640 case SSH_CHANNEL_CLOSED:
641 case SSH_CHANNEL_AUTH_SOCKET:
642 case SSH_CHANNEL_ZOMBIE:
643 case SSH_CHANNEL_ABANDONED:
644 case SSH_CHANNEL_MUX_CLIENT:
645 case SSH_CHANNEL_MUX_LISTENER:
646 case SSH_CHANNEL_UNIX_LISTENER:
647 case SSH_CHANNEL_RUNIX_LISTENER:
649 case SSH_CHANNEL_LARVAL:
650 case SSH_CHANNEL_OPENING:
651 case SSH_CHANNEL_CONNECTING:
652 case SSH_CHANNEL_DYNAMIC:
653 case SSH_CHANNEL_OPEN:
654 case SSH_CHANNEL_X11_OPEN:
655 case SSH_CHANNEL_INPUT_DRAINING:
656 case SSH_CHANNEL_OUTPUT_DRAINING:
657 snprintf(buf, sizeof buf,
658 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
659 c->self, c->remote_name,
660 c->type, c->remote_id,
661 c->istate, buffer_len(&c->input),
662 c->ostate, buffer_len(&c->output),
663 c->rfd, c->wfd, c->ctl_chan);
664 buffer_append(&buffer, buf, strlen(buf));
667 fatal("channel_open_message: bad channel type %d", c->type);
671 buffer_append(&buffer, "\0", 1);
672 cp = xstrdup(buffer_ptr(&buffer));
673 buffer_free(&buffer);
678 channel_send_open(int id)
680 Channel *c = channel_lookup(id);
683 logit("channel_send_open: %d: bad id", id);
686 debug2("channel %d: send open", id);
687 packet_start(SSH2_MSG_CHANNEL_OPEN);
688 packet_put_cstring(c->ctype);
689 packet_put_int(c->self);
690 packet_put_int(c->local_window);
691 packet_put_int(c->local_maxpacket);
696 channel_request_start(int id, char *service, int wantconfirm)
698 Channel *c = channel_lookup(id);
701 logit("channel_request_start: %d: unknown channel id", id);
704 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
705 packet_start(SSH2_MSG_CHANNEL_REQUEST);
706 packet_put_int(c->remote_id);
707 packet_put_cstring(service);
708 packet_put_char(wantconfirm);
712 channel_register_status_confirm(int id, channel_confirm_cb *cb,
713 channel_confirm_abandon_cb *abandon_cb, void *ctx)
715 struct channel_confirm *cc;
718 if ((c = channel_lookup(id)) == NULL)
719 fatal("channel_register_expect: %d: bad id", id);
721 cc = xcalloc(1, sizeof(*cc));
723 cc->abandon_cb = abandon_cb;
725 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
729 channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
731 Channel *c = channel_lookup(id);
734 logit("channel_register_open_confirm: %d: bad id", id);
737 c->open_confirm = fn;
738 c->open_confirm_ctx = ctx;
742 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
744 Channel *c = channel_by_id(id);
747 logit("channel_register_cleanup: %d: bad id", id);
751 c->detach_close = do_close;
755 channel_cancel_cleanup(int id)
757 Channel *c = channel_by_id(id);
760 logit("channel_cancel_cleanup: %d: bad id", id);
763 c->detach_user = NULL;
768 channel_register_filter(int id, channel_infilter_fn *ifn,
769 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
771 Channel *c = channel_lookup(id);
774 logit("channel_register_filter: %d: bad id", id);
777 c->input_filter = ifn;
778 c->output_filter = ofn;
780 c->filter_cleanup = cfn;
784 channel_set_fds(int id, int rfd, int wfd, int efd,
785 int extusage, int nonblock, int is_tty, u_int window_max)
787 Channel *c = channel_lookup(id);
789 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
790 fatal("channel_activate for non-larval channel %d.", id);
791 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
792 c->type = SSH_CHANNEL_OPEN;
793 c->local_window = c->local_window_max = window_max;
794 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
795 packet_put_int(c->remote_id);
796 packet_put_int(c->local_window);
801 * 'channel_pre*' are called just before select() to add any bits relevant to
802 * channels in the select bitmasks.
805 * 'channel_post*': perform any appropriate operations for channels which
806 * have events pending.
808 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
809 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
810 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
814 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
816 FD_SET(c->sock, readset);
821 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
823 debug3("channel %d: waiting for connection", c->self);
824 FD_SET(c->sock, writeset);
828 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
830 if (buffer_len(&c->input) < packet_get_maxsize())
831 FD_SET(c->sock, readset);
832 if (buffer_len(&c->output) > 0)
833 FD_SET(c->sock, writeset);
837 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
839 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
841 if (c->istate == CHAN_INPUT_OPEN &&
843 buffer_len(&c->input) < limit &&
844 buffer_check_alloc(&c->input, CHAN_RBUF))
845 FD_SET(c->rfd, readset);
846 if (c->ostate == CHAN_OUTPUT_OPEN ||
847 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
848 if (buffer_len(&c->output) > 0) {
849 FD_SET(c->wfd, writeset);
850 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
851 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
852 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
853 c->self, c->efd, buffer_len(&c->extended));
858 /** XXX check close conditions, too */
859 if (compat20 && c->efd != -1 &&
860 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
861 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
862 buffer_len(&c->extended) > 0)
863 FD_SET(c->efd, writeset);
864 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
865 (c->extended_usage == CHAN_EXTENDED_READ ||
866 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
867 buffer_len(&c->extended) < c->remote_window)
868 FD_SET(c->efd, readset);
870 /* XXX: What about efd? races? */
875 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
877 if (buffer_len(&c->input) == 0) {
878 packet_start(SSH_MSG_CHANNEL_CLOSE);
879 packet_put_int(c->remote_id);
881 c->type = SSH_CHANNEL_CLOSED;
882 debug2("channel %d: closing after input drain.", c->self);
888 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
890 if (buffer_len(&c->output) == 0)
893 FD_SET(c->sock, writeset);
897 * This is a special state for X11 authentication spoofing. An opened X11
898 * connection (when authentication spoofing is being done) remains in this
899 * state until the first packet has been completely read. The authentication
900 * data in that packet is then substituted by the real data if it matches the
901 * fake data, and the channel is put into normal mode.
902 * XXX All this happens at the client side.
903 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
906 x11_open_helper(Buffer *b)
909 u_int proto_len, data_len;
911 /* Check if the fixed size part of the packet is in buffer. */
912 if (buffer_len(b) < 12)
915 /* Parse the lengths of variable-length fields. */
917 if (ucp[0] == 0x42) { /* Byte order MSB first. */
918 proto_len = 256 * ucp[6] + ucp[7];
919 data_len = 256 * ucp[8] + ucp[9];
920 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
921 proto_len = ucp[6] + 256 * ucp[7];
922 data_len = ucp[8] + 256 * ucp[9];
924 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
929 /* Check if the whole packet is in buffer. */
931 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
934 /* Check if authentication protocol matches. */
935 if (proto_len != strlen(x11_saved_proto) ||
936 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
937 debug2("X11 connection uses different authentication protocol.");
940 /* Check if authentication data matches our fake data. */
941 if (data_len != x11_fake_data_len ||
942 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
943 x11_fake_data, x11_fake_data_len) != 0) {
944 debug2("X11 auth data does not match fake data.");
947 /* Check fake data length */
948 if (x11_fake_data_len != x11_saved_data_len) {
949 error("X11 fake_data_len %d != saved_data_len %d",
950 x11_fake_data_len, x11_saved_data_len);
954 * Received authentication protocol and data match
955 * our fake data. Substitute the fake data with real
958 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
959 x11_saved_data, x11_saved_data_len);
964 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
966 int ret = x11_open_helper(&c->output);
969 /* Start normal processing for the channel. */
970 c->type = SSH_CHANNEL_OPEN;
971 channel_pre_open_13(c, readset, writeset);
972 } else if (ret == -1) {
974 * We have received an X11 connection that has bad
975 * authentication information.
977 logit("X11 connection rejected because of wrong authentication.");
978 buffer_clear(&c->input);
979 buffer_clear(&c->output);
980 channel_close_fd(&c->sock);
982 c->type = SSH_CHANNEL_CLOSED;
983 packet_start(SSH_MSG_CHANNEL_CLOSE);
984 packet_put_int(c->remote_id);
990 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
992 int ret = x11_open_helper(&c->output);
994 /* c->force_drain = 1; */
997 c->type = SSH_CHANNEL_OPEN;
998 channel_pre_open(c, readset, writeset);
999 } else if (ret == -1) {
1000 logit("X11 connection rejected because of wrong authentication.");
1001 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1002 chan_read_failed(c);
1003 buffer_clear(&c->input);
1005 buffer_clear(&c->output);
1006 /* for proto v1, the peer will send an IEOF */
1008 chan_write_failed(c);
1010 c->type = SSH_CHANNEL_OPEN;
1011 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1016 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1018 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1019 buffer_check_alloc(&c->input, CHAN_RBUF))
1020 FD_SET(c->rfd, readset);
1021 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1022 /* clear buffer immediately (discard any partial packet) */
1023 buffer_clear(&c->input);
1025 /* Start output drain. XXX just kill chan? */
1026 chan_rcvd_oclose(c);
1028 if (c->ostate == CHAN_OUTPUT_OPEN ||
1029 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1030 if (buffer_len(&c->output) > 0)
1031 FD_SET(c->wfd, writeset);
1032 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1037 /* try to decode a socks4 header */
1040 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1043 u_int len, have, i, found, need;
1048 u_int16_t dest_port;
1049 struct in_addr dest_addr;
1052 debug2("channel %d: decode socks4", c->self);
1054 have = buffer_len(&c->input);
1055 len = sizeof(s4_req);
1058 p = buffer_ptr(&c->input);
1061 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1062 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1063 debug2("channel %d: socks4a request", c->self);
1064 /* ... and needs an extra string (the hostname) */
1067 /* Check for terminating NUL on the string(s) */
1068 for (found = 0, i = len; i < have; i++) {
1075 /* the peer is probably sending garbage */
1076 debug("channel %d: decode socks4: too long",
1083 buffer_get(&c->input, (char *)&s4_req.version, 1);
1084 buffer_get(&c->input, (char *)&s4_req.command, 1);
1085 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1086 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1087 have = buffer_len(&c->input);
1088 p = buffer_ptr(&c->input);
1089 if (memchr(p, '\0', have) == NULL)
1090 fatal("channel %d: decode socks4: user not nul terminated",
1093 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1094 len++; /* trailing '\0' */
1096 fatal("channel %d: decode socks4: len %d > have %d",
1097 c->self, len, have);
1098 strlcpy(username, p, sizeof(username));
1099 buffer_consume(&c->input, len);
1103 if (need == 1) { /* SOCKS4: one string */
1104 host = inet_ntoa(s4_req.dest_addr);
1105 c->path = xstrdup(host);
1106 } else { /* SOCKS4A: two strings */
1107 have = buffer_len(&c->input);
1108 p = buffer_ptr(&c->input);
1110 debug2("channel %d: decode socks4a: host %s/%d",
1112 len++; /* trailing '\0' */
1114 fatal("channel %d: decode socks4a: len %d > have %d",
1115 c->self, len, have);
1116 if (len > NI_MAXHOST) {
1117 error("channel %d: hostname \"%.100s\" too long",
1121 c->path = xstrdup(p);
1122 buffer_consume(&c->input, len);
1124 c->host_port = ntohs(s4_req.dest_port);
1126 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1127 c->self, c->path, c->host_port, s4_req.command);
1129 if (s4_req.command != 1) {
1130 debug("channel %d: cannot handle: %s cn %d",
1131 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1134 s4_rsp.version = 0; /* vn: 0 for reply */
1135 s4_rsp.command = 90; /* cd: req granted */
1136 s4_rsp.dest_port = 0; /* ignored */
1137 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1138 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1142 /* try to decode a socks5 header */
1143 #define SSH_SOCKS5_AUTHDONE 0x1000
1144 #define SSH_SOCKS5_NOAUTH 0x00
1145 #define SSH_SOCKS5_IPV4 0x01
1146 #define SSH_SOCKS5_DOMAIN 0x03
1147 #define SSH_SOCKS5_IPV6 0x04
1148 #define SSH_SOCKS5_CONNECT 0x01
1149 #define SSH_SOCKS5_SUCCESS 0x00
1153 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1161 u_int16_t dest_port;
1162 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1164 u_int have, need, i, found, nmethods, addrlen, af;
1166 debug2("channel %d: decode socks5", c->self);
1167 p = buffer_ptr(&c->input);
1170 have = buffer_len(&c->input);
1171 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1172 /* format: ver | nmethods | methods */
1176 if (have < nmethods + 2)
1178 /* look for method: "NO AUTHENTICATION REQUIRED" */
1179 for (found = 0, i = 2; i < nmethods + 2; i++) {
1180 if (p[i] == SSH_SOCKS5_NOAUTH) {
1186 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1190 buffer_consume(&c->input, nmethods + 2);
1191 buffer_put_char(&c->output, 0x05); /* version */
1192 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1193 FD_SET(c->sock, writeset);
1194 c->flags |= SSH_SOCKS5_AUTHDONE;
1195 debug2("channel %d: socks5 auth done", c->self);
1196 return 0; /* need more */
1198 debug2("channel %d: socks5 post auth", c->self);
1199 if (have < sizeof(s5_req)+1)
1200 return 0; /* need more */
1201 memcpy(&s5_req, p, sizeof(s5_req));
1202 if (s5_req.version != 0x05 ||
1203 s5_req.command != SSH_SOCKS5_CONNECT ||
1204 s5_req.reserved != 0x00) {
1205 debug2("channel %d: only socks5 connect supported", c->self);
1208 switch (s5_req.atyp){
1209 case SSH_SOCKS5_IPV4:
1213 case SSH_SOCKS5_DOMAIN:
1214 addrlen = p[sizeof(s5_req)];
1217 case SSH_SOCKS5_IPV6:
1222 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1225 need = sizeof(s5_req) + addrlen + 2;
1226 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1230 buffer_consume(&c->input, sizeof(s5_req));
1231 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1232 buffer_consume(&c->input, 1); /* host string length */
1233 buffer_get(&c->input, &dest_addr, addrlen);
1234 buffer_get(&c->input, (char *)&dest_port, 2);
1235 dest_addr[addrlen] = '\0';
1238 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1239 if (addrlen >= NI_MAXHOST) {
1240 error("channel %d: dynamic request: socks5 hostname "
1241 "\"%.100s\" too long", c->self, dest_addr);
1244 c->path = xstrdup(dest_addr);
1246 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1248 c->path = xstrdup(ntop);
1250 c->host_port = ntohs(dest_port);
1252 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1253 c->self, c->path, c->host_port, s5_req.command);
1255 s5_rsp.version = 0x05;
1256 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1257 s5_rsp.reserved = 0; /* ignored */
1258 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1259 dest_port = 0; /* ignored */
1261 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1262 buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1263 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1268 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1273 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1276 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1277 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1278 0, "stdio-forward", /*nonblock*/0);
1280 c->path = xstrdup(host_to_connect);
1281 c->host_port = port_to_connect;
1282 c->listening_port = 0;
1285 channel_register_fds(c, in, out, -1, 0, 1, 0);
1286 port_open_helper(c, "direct-tcpip");
1291 /* dynamic port forwarding */
1293 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1299 have = buffer_len(&c->input);
1300 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1301 /* buffer_dump(&c->input); */
1302 /* check if the fixed size part of the packet is in buffer. */
1305 FD_SET(c->sock, readset);
1308 /* try to guess the protocol */
1309 p = buffer_ptr(&c->input);
1312 ret = channel_decode_socks4(c, readset, writeset);
1315 ret = channel_decode_socks5(c, readset, writeset);
1323 } else if (ret == 0) {
1324 debug2("channel %d: pre_dynamic: need more", c->self);
1326 FD_SET(c->sock, readset);
1328 /* switch to the next state */
1329 c->type = SSH_CHANNEL_OPENING;
1330 port_open_helper(c, "direct-tcpip");
1334 /* This is our fake X11 server socket. */
1337 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1340 struct sockaddr_storage addr;
1341 int newsock, oerrno;
1343 char buf[16384], *remote_ipaddr;
1346 if (FD_ISSET(c->sock, readset)) {
1347 debug("X11 connection requested.");
1348 addrlen = sizeof(addr);
1349 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1350 if (c->single_connection) {
1352 debug2("single_connection: closing X11 listener.");
1353 channel_close_fd(&c->sock);
1358 if (errno != EINTR && errno != EWOULDBLOCK &&
1359 errno != ECONNABORTED)
1360 error("accept: %.100s", strerror(errno));
1361 if (errno == EMFILE || errno == ENFILE)
1362 c->notbefore = monotime() + 1;
1365 set_nodelay(newsock);
1366 remote_ipaddr = get_peer_ipaddr(newsock);
1367 remote_port = get_peer_port(newsock);
1368 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1369 remote_ipaddr, remote_port);
1371 nc = channel_new("accepted x11 socket",
1372 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1373 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1375 packet_start(SSH2_MSG_CHANNEL_OPEN);
1376 packet_put_cstring("x11");
1377 packet_put_int(nc->self);
1378 packet_put_int(nc->local_window_max);
1379 packet_put_int(nc->local_maxpacket);
1380 /* originator ipaddr and port */
1381 packet_put_cstring(remote_ipaddr);
1382 if (datafellows & SSH_BUG_X11FWD) {
1383 debug2("ssh2 x11 bug compat mode");
1385 packet_put_int(remote_port);
1389 packet_start(SSH_SMSG_X11_OPEN);
1390 packet_put_int(nc->self);
1391 if (packet_get_protocol_flags() &
1392 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1393 packet_put_cstring(buf);
1396 free(remote_ipaddr);
1401 port_open_helper(Channel *c, char *rtype)
1404 char *local_ipaddr = get_local_ipaddr(c->sock);
1405 int local_port = c->sock == -1 ? 65536 : get_sock_port(c->sock, 1);
1406 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1407 int remote_port = get_peer_port(c->sock);
1409 if (remote_port == -1) {
1410 /* Fake addr/port to appease peers that validate it (Tectia) */
1411 free(remote_ipaddr);
1412 remote_ipaddr = xstrdup("127.0.0.1");
1413 remote_port = 65535;
1416 snprintf(buf, sizeof buf,
1417 "%s: listening port %d for %.100s port %d, "
1418 "connect from %.200s port %d to %.100s port %d",
1419 rtype, c->listening_port, c->path, c->host_port,
1420 remote_ipaddr, remote_port, local_ipaddr, local_port);
1422 free(c->remote_name);
1423 c->remote_name = xstrdup(buf);
1426 packet_start(SSH2_MSG_CHANNEL_OPEN);
1427 packet_put_cstring(rtype);
1428 packet_put_int(c->self);
1429 packet_put_int(c->local_window_max);
1430 packet_put_int(c->local_maxpacket);
1431 if (strcmp(rtype, "direct-tcpip") == 0) {
1432 /* target host, port */
1433 packet_put_cstring(c->path);
1434 packet_put_int(c->host_port);
1435 } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1437 packet_put_cstring(c->path);
1438 } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1440 packet_put_cstring(c->path);
1442 /* listen address, port */
1443 packet_put_cstring(c->path);
1444 packet_put_int(local_port);
1446 if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1447 /* reserved for future owner/mode info */
1448 packet_put_cstring("");
1450 /* originator host and port */
1451 packet_put_cstring(remote_ipaddr);
1452 packet_put_int((u_int)remote_port);
1456 packet_start(SSH_MSG_PORT_OPEN);
1457 packet_put_int(c->self);
1458 packet_put_cstring(c->path);
1459 packet_put_int(c->host_port);
1460 if (packet_get_protocol_flags() &
1461 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1462 packet_put_cstring(c->remote_name);
1465 free(remote_ipaddr);
1470 channel_set_reuseaddr(int fd)
1475 * Set socket options.
1476 * Allow local port reuse in TIME_WAIT.
1478 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1479 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1483 * This socket is listening for connections to a forwarded TCP/IP port.
1487 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1490 struct sockaddr_storage addr;
1491 int newsock, nextstate;
1495 if (FD_ISSET(c->sock, readset)) {
1496 debug("Connection to port %d forwarding "
1497 "to %.100s port %d requested.",
1498 c->listening_port, c->path, c->host_port);
1500 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1501 nextstate = SSH_CHANNEL_OPENING;
1502 rtype = "forwarded-tcpip";
1503 } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1504 nextstate = SSH_CHANNEL_OPENING;
1505 rtype = "forwarded-streamlocal@openssh.com";
1506 } else if (c->host_port == PORT_STREAMLOCAL) {
1507 nextstate = SSH_CHANNEL_OPENING;
1508 rtype = "direct-streamlocal@openssh.com";
1509 } else if (c->host_port == 0) {
1510 nextstate = SSH_CHANNEL_DYNAMIC;
1511 rtype = "dynamic-tcpip";
1513 nextstate = SSH_CHANNEL_OPENING;
1514 rtype = "direct-tcpip";
1517 addrlen = sizeof(addr);
1518 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1520 if (errno != EINTR && errno != EWOULDBLOCK &&
1521 errno != ECONNABORTED)
1522 error("accept: %.100s", strerror(errno));
1523 if (errno == EMFILE || errno == ENFILE)
1524 c->notbefore = monotime() + 1;
1527 if (c->host_port != PORT_STREAMLOCAL)
1528 set_nodelay(newsock);
1529 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1530 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1531 nc->listening_port = c->listening_port;
1532 nc->host_port = c->host_port;
1533 if (c->path != NULL)
1534 nc->path = xstrdup(c->path);
1536 if (nextstate != SSH_CHANNEL_DYNAMIC)
1537 port_open_helper(nc, rtype);
1542 * This is the authentication agent socket listening for connections from
1547 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1551 struct sockaddr_storage addr;
1554 if (FD_ISSET(c->sock, readset)) {
1555 addrlen = sizeof(addr);
1556 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1558 error("accept from auth socket: %.100s",
1560 if (errno == EMFILE || errno == ENFILE)
1561 c->notbefore = monotime() + 1;
1564 nc = channel_new("accepted auth socket",
1565 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1566 c->local_window_max, c->local_maxpacket,
1567 0, "accepted auth socket", 1);
1569 packet_start(SSH2_MSG_CHANNEL_OPEN);
1570 packet_put_cstring("auth-agent@openssh.com");
1571 packet_put_int(nc->self);
1572 packet_put_int(c->local_window_max);
1573 packet_put_int(c->local_maxpacket);
1575 packet_start(SSH_SMSG_AGENT_OPEN);
1576 packet_put_int(nc->self);
1584 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1587 socklen_t sz = sizeof(err);
1589 if (FD_ISSET(c->sock, writeset)) {
1590 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1592 error("getsockopt SO_ERROR failed");
1595 debug("channel %d: connected to %s port %d",
1596 c->self, c->connect_ctx.host, c->connect_ctx.port);
1597 channel_connect_ctx_free(&c->connect_ctx);
1598 c->type = SSH_CHANNEL_OPEN;
1600 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1601 packet_put_int(c->remote_id);
1602 packet_put_int(c->self);
1603 packet_put_int(c->local_window);
1604 packet_put_int(c->local_maxpacket);
1606 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1607 packet_put_int(c->remote_id);
1608 packet_put_int(c->self);
1611 debug("channel %d: connection failed: %s",
1612 c->self, strerror(err));
1613 /* Try next address, if any */
1614 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1616 c->sock = c->rfd = c->wfd = sock;
1617 channel_max_fd = channel_find_maxfd();
1620 /* Exhausted all addresses */
1621 error("connect_to %.100s port %d: failed.",
1622 c->connect_ctx.host, c->connect_ctx.port);
1623 channel_connect_ctx_free(&c->connect_ctx);
1625 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1626 packet_put_int(c->remote_id);
1627 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1628 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1629 packet_put_cstring(strerror(err));
1630 packet_put_cstring("");
1633 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1634 packet_put_int(c->remote_id);
1644 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1646 char buf[CHAN_RBUF];
1649 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1650 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1652 len = read(c->rfd, buf, sizeof(buf));
1653 if (len < 0 && (errno == EINTR ||
1654 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1656 #ifndef PTY_ZEROREAD
1659 if ((!c->isatty && len <= 0) ||
1660 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1662 debug2("channel %d: read<=0 rfd %d len %d",
1663 c->self, c->rfd, len);
1664 if (c->type != SSH_CHANNEL_OPEN) {
1665 debug2("channel %d: not open", c->self);
1668 } else if (compat13) {
1669 buffer_clear(&c->output);
1670 c->type = SSH_CHANNEL_INPUT_DRAINING;
1671 debug2("channel %d: input draining.", c->self);
1673 chan_read_failed(c);
1677 if (c->input_filter != NULL) {
1678 if (c->input_filter(c, buf, len) == -1) {
1679 debug2("channel %d: filter stops", c->self);
1680 chan_read_failed(c);
1682 } else if (c->datagram) {
1683 buffer_put_string(&c->input, buf, len);
1685 buffer_append(&c->input, buf, len);
1693 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1696 u_char *data = NULL, *buf;
1697 u_int dlen, olen = 0;
1700 /* Send buffered output data to the socket. */
1702 FD_ISSET(c->wfd, writeset) &&
1703 buffer_len(&c->output) > 0) {
1704 olen = buffer_len(&c->output);
1705 if (c->output_filter != NULL) {
1706 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1707 debug2("channel %d: filter stops", c->self);
1708 if (c->type != SSH_CHANNEL_OPEN)
1711 chan_write_failed(c);
1714 } else if (c->datagram) {
1715 buf = data = buffer_get_string(&c->output, &dlen);
1717 buf = data = buffer_ptr(&c->output);
1718 dlen = buffer_len(&c->output);
1722 /* ignore truncated writes, datagrams might get lost */
1723 len = write(c->wfd, buf, dlen);
1725 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1726 errno == EWOULDBLOCK))
1729 if (c->type != SSH_CHANNEL_OPEN)
1732 chan_write_failed(c);
1738 /* XXX: Later AIX versions can't push as much data to tty */
1739 if (compat20 && c->wfd_isatty)
1740 dlen = MIN(dlen, 8*1024);
1743 len = write(c->wfd, buf, dlen);
1745 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1748 if (c->type != SSH_CHANNEL_OPEN) {
1749 debug2("channel %d: not open", c->self);
1752 } else if (compat13) {
1753 buffer_clear(&c->output);
1754 debug2("channel %d: input draining.", c->self);
1755 c->type = SSH_CHANNEL_INPUT_DRAINING;
1757 chan_write_failed(c);
1761 #ifndef BROKEN_TCGETATTR_ICANON
1762 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1763 if (tcgetattr(c->wfd, &tio) == 0 &&
1764 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1766 * Simulate echo to reduce the impact of
1767 * traffic analysis. We need to match the
1768 * size of a SSH2_MSG_CHANNEL_DATA message
1769 * (4 byte channel id + buf)
1771 packet_send_ignore(4 + len);
1776 buffer_consume(&c->output, len);
1779 if (compat20 && olen > 0)
1780 c->local_consumed += olen - buffer_len(&c->output);
1785 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1787 char buf[CHAN_RBUF];
1790 /** XXX handle drain efd, too */
1792 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1793 FD_ISSET(c->efd, writeset) &&
1794 buffer_len(&c->extended) > 0) {
1795 len = write(c->efd, buffer_ptr(&c->extended),
1796 buffer_len(&c->extended));
1797 debug2("channel %d: written %d to efd %d",
1798 c->self, len, c->efd);
1799 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1800 errno == EWOULDBLOCK))
1803 debug2("channel %d: closing write-efd %d",
1805 channel_close_fd(&c->efd);
1807 buffer_consume(&c->extended, len);
1808 c->local_consumed += len;
1810 } else if (c->efd != -1 &&
1811 (c->extended_usage == CHAN_EXTENDED_READ ||
1812 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1813 (c->detach_close || FD_ISSET(c->efd, readset))) {
1814 len = read(c->efd, buf, sizeof(buf));
1815 debug2("channel %d: read %d from efd %d",
1816 c->self, len, c->efd);
1817 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1818 errno == EWOULDBLOCK) && !c->detach_close)))
1821 debug2("channel %d: closing read-efd %d",
1823 channel_close_fd(&c->efd);
1825 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1826 debug3("channel %d: discard efd",
1829 buffer_append(&c->extended, buf, len);
1837 channel_check_window(Channel *c)
1839 if (c->type == SSH_CHANNEL_OPEN &&
1840 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1841 ((c->local_window_max - c->local_window >
1842 c->local_maxpacket*3) ||
1843 c->local_window < c->local_window_max/2) &&
1844 c->local_consumed > 0) {
1845 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1846 packet_put_int(c->remote_id);
1847 packet_put_int(c->local_consumed);
1849 debug2("channel %d: window %d sent adjust %d",
1850 c->self, c->local_window,
1852 c->local_window += c->local_consumed;
1853 c->local_consumed = 0;
1859 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1861 channel_handle_rfd(c, readset, writeset);
1862 channel_handle_wfd(c, readset, writeset);
1865 channel_handle_efd(c, readset, writeset);
1866 channel_check_window(c);
1870 read_mux(Channel *c, u_int need)
1872 char buf[CHAN_RBUF];
1876 if (buffer_len(&c->input) < need) {
1877 rlen = need - buffer_len(&c->input);
1878 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1880 if (errno != EINTR && errno != EAGAIN) {
1881 debug2("channel %d: ctl read<=0 rfd %d len %d",
1882 c->self, c->rfd, len);
1883 chan_read_failed(c);
1887 buffer_append(&c->input, buf, len);
1889 return buffer_len(&c->input);
1893 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1899 fatal("%s: entered with !compat20", __func__);
1901 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1902 (c->istate == CHAN_INPUT_OPEN ||
1903 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1905 * Don't not read past the precise end of packets to
1906 * avoid disrupting fd passing.
1908 if (read_mux(c, 4) < 4) /* read header */
1910 need = get_u32(buffer_ptr(&c->input));
1911 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1912 if (need > CHANNEL_MUX_MAX_PACKET) {
1913 debug2("channel %d: packet too big %u > %u",
1914 c->self, CHANNEL_MUX_MAX_PACKET, need);
1915 chan_rcvd_oclose(c);
1918 if (read_mux(c, need + 4) < need + 4) /* read body */
1920 if (c->mux_rcb(c) != 0) {
1921 debug("channel %d: mux_rcb failed", c->self);
1927 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1928 buffer_len(&c->output) > 0) {
1929 len = write(c->wfd, buffer_ptr(&c->output),
1930 buffer_len(&c->output));
1931 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1937 buffer_consume(&c->output, len);
1942 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1945 struct sockaddr_storage addr;
1951 if (!FD_ISSET(c->sock, readset))
1954 debug("multiplexing control connection");
1957 * Accept connection on control socket
1959 memset(&addr, 0, sizeof(addr));
1960 addrlen = sizeof(addr);
1961 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1963 error("%s accept: %s", __func__, strerror(errno));
1964 if (errno == EMFILE || errno == ENFILE)
1965 c->notbefore = monotime() + 1;
1969 if (getpeereid(newsock, &euid, &egid) < 0) {
1970 error("%s getpeereid failed: %s", __func__,
1975 if ((euid != 0) && (getuid() != euid)) {
1976 error("multiplex uid mismatch: peer euid %u != uid %u",
1977 (u_int)euid, (u_int)getuid());
1981 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1982 newsock, newsock, -1, c->local_window_max,
1983 c->local_maxpacket, 0, "mux-control", 1);
1984 nc->mux_rcb = c->mux_rcb;
1985 debug3("%s: new mux channel %d fd %d", __func__,
1986 nc->self, nc->sock);
1987 /* establish state */
1989 /* mux state transitions must not elicit protocol messages */
1990 nc->flags |= CHAN_LOCAL;
1995 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1999 /* Send buffered output data to the socket. */
2000 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2001 len = write(c->sock, buffer_ptr(&c->output),
2002 buffer_len(&c->output));
2004 buffer_clear(&c->output);
2006 buffer_consume(&c->output, len);
2011 channel_handler_init_20(void)
2013 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2014 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2015 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2016 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2017 channel_pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2018 channel_pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
2019 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2020 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2021 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2022 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2023 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2024 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2026 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2027 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2028 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2029 channel_post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2030 channel_post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
2031 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2032 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2033 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2034 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2035 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2036 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2040 channel_handler_init_13(void)
2042 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2043 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2044 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2045 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2046 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2047 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2048 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2049 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2050 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2052 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2053 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2054 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2055 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2056 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2057 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2058 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2062 channel_handler_init_15(void)
2064 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2065 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2066 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2067 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2068 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2069 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2070 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2072 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2073 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2074 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2075 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2076 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2077 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2081 channel_handler_init(void)
2085 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2086 channel_pre[i] = NULL;
2087 channel_post[i] = NULL;
2090 channel_handler_init_20();
2092 channel_handler_init_13();
2094 channel_handler_init_15();
2097 /* gc dead channels */
2099 channel_garbage_collect(Channel *c)
2103 if (c->detach_user != NULL) {
2104 if (!chan_is_dead(c, c->detach_close))
2106 debug2("channel %d: gc: notify user", c->self);
2107 c->detach_user(c->self, NULL);
2108 /* if we still have a callback */
2109 if (c->detach_user != NULL)
2111 debug2("channel %d: gc: user detached", c->self);
2113 if (!chan_is_dead(c, 1))
2115 debug2("channel %d: garbage collecting", c->self);
2120 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2121 time_t *unpause_secs)
2123 static int did_init = 0;
2129 channel_handler_init();
2133 if (unpause_secs != NULL)
2135 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2140 if (ftab == channel_pre)
2145 if (ftab[c->type] != NULL) {
2147 * Run handlers that are not paused.
2149 if (c->notbefore <= now)
2150 (*ftab[c->type])(c, readset, writeset);
2151 else if (unpause_secs != NULL) {
2153 * Collect the time that the earliest
2154 * channel comes off pause.
2156 debug3("%s: chan %d: skip for %d more seconds",
2158 (int)(c->notbefore - now));
2159 if (*unpause_secs == 0 ||
2160 (c->notbefore - now) < *unpause_secs)
2161 *unpause_secs = c->notbefore - now;
2164 channel_garbage_collect(c);
2166 if (unpause_secs != NULL && *unpause_secs != 0)
2167 debug3("%s: first channel unpauses in %d seconds",
2168 __func__, (int)*unpause_secs);
2172 * Allocate/update select bitmasks and add any bits relevant to channels in
2176 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2177 u_int *nallocp, time_t *minwait_secs, int rekeying)
2179 u_int n, sz, nfdset;
2181 n = MAX(*maxfdp, channel_max_fd);
2183 nfdset = howmany(n+1, NFDBITS);
2184 /* Explicitly test here, because xrealloc isn't always called */
2185 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2186 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2187 sz = nfdset * sizeof(fd_mask);
2189 /* perhaps check sz < nalloc/2 and shrink? */
2190 if (*readsetp == NULL || sz > *nallocp) {
2191 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2192 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2196 memset(*readsetp, 0, sz);
2197 memset(*writesetp, 0, sz);
2200 channel_handler(channel_pre, *readsetp, *writesetp,
2205 * After select, perform any appropriate operations for channels which have
2209 channel_after_select(fd_set *readset, fd_set *writeset)
2211 channel_handler(channel_post, readset, writeset, NULL);
2215 /* If there is data to send to the connection, enqueue some of it now. */
2217 channel_output_poll(void)
2222 for (i = 0; i < channels_alloc; i++) {
2228 * We are only interested in channels that can have buffered
2232 if (c->type != SSH_CHANNEL_OPEN &&
2233 c->type != SSH_CHANNEL_INPUT_DRAINING)
2236 if (c->type != SSH_CHANNEL_OPEN)
2240 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2241 /* XXX is this true? */
2242 debug3("channel %d: will not send data after close", c->self);
2246 /* Get the amount of buffered data for this channel. */
2247 if ((c->istate == CHAN_INPUT_OPEN ||
2248 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2249 (len = buffer_len(&c->input)) > 0) {
2255 data = buffer_get_string(&c->input,
2257 if (dlen > c->remote_window ||
2258 dlen > c->remote_maxpacket) {
2259 debug("channel %d: datagram "
2260 "too big for channel",
2265 packet_start(SSH2_MSG_CHANNEL_DATA);
2266 packet_put_int(c->remote_id);
2267 packet_put_string(data, dlen);
2269 c->remote_window -= dlen + 4;
2275 * Send some data for the other side over the secure
2279 if (len > c->remote_window)
2280 len = c->remote_window;
2281 if (len > c->remote_maxpacket)
2282 len = c->remote_maxpacket;
2284 if (packet_is_interactive()) {
2288 /* Keep the packets at reasonable size. */
2289 if (len > packet_get_maxsize()/2)
2290 len = packet_get_maxsize()/2;
2294 packet_start(compat20 ?
2295 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2296 packet_put_int(c->remote_id);
2297 packet_put_string(buffer_ptr(&c->input), len);
2299 buffer_consume(&c->input, len);
2300 c->remote_window -= len;
2302 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2304 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2306 * input-buffer is empty and read-socket shutdown:
2307 * tell peer, that we will not send more data: send IEOF.
2308 * hack for extended data: delay EOF if EFD still in use.
2310 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2311 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2312 c->self, c->efd, buffer_len(&c->extended));
2316 /* Send extended data, i.e. stderr */
2318 !(c->flags & CHAN_EOF_SENT) &&
2319 c->remote_window > 0 &&
2320 (len = buffer_len(&c->extended)) > 0 &&
2321 c->extended_usage == CHAN_EXTENDED_READ) {
2322 debug2("channel %d: rwin %u elen %u euse %d",
2323 c->self, c->remote_window, buffer_len(&c->extended),
2325 if (len > c->remote_window)
2326 len = c->remote_window;
2327 if (len > c->remote_maxpacket)
2328 len = c->remote_maxpacket;
2329 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2330 packet_put_int(c->remote_id);
2331 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2332 packet_put_string(buffer_ptr(&c->extended), len);
2334 buffer_consume(&c->extended, len);
2335 c->remote_window -= len;
2336 debug2("channel %d: sent ext data %d", c->self, len);
2342 /* -- protocol input */
2346 channel_input_data(int type, u_int32_t seq, void *ctxt)
2350 u_int data_len, win_len;
2353 /* Get the channel number and verify it. */
2354 id = packet_get_int();
2355 c = channel_lookup(id);
2357 packet_disconnect("Received data for nonexistent channel %d.", id);
2359 /* Ignore any data for non-open channels (might happen on close) */
2360 if (c->type != SSH_CHANNEL_OPEN &&
2361 c->type != SSH_CHANNEL_X11_OPEN)
2365 data = packet_get_string_ptr(&data_len);
2368 win_len += 4; /* string length header */
2371 * Ignore data for protocol > 1.3 if output end is no longer open.
2372 * For protocol 2 the sending side is reducing its window as it sends
2373 * data, so we must 'fake' consumption of the data in order to ensure
2374 * that window updates are sent back. Otherwise the connection might
2377 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2379 c->local_window -= win_len;
2380 c->local_consumed += win_len;
2386 if (win_len > c->local_maxpacket) {
2387 logit("channel %d: rcvd big packet %d, maxpack %d",
2388 c->self, win_len, c->local_maxpacket);
2390 if (win_len > c->local_window) {
2391 logit("channel %d: rcvd too much data %d, win %d",
2392 c->self, win_len, c->local_window);
2395 c->local_window -= win_len;
2398 buffer_put_string(&c->output, data, data_len);
2400 buffer_append(&c->output, data, data_len);
2406 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2410 u_int data_len, tcode;
2413 /* Get the channel number and verify it. */
2414 id = packet_get_int();
2415 c = channel_lookup(id);
2418 packet_disconnect("Received extended_data for bad channel %d.", id);
2419 if (c->type != SSH_CHANNEL_OPEN) {
2420 logit("channel %d: ext data for non open", id);
2423 if (c->flags & CHAN_EOF_RCVD) {
2424 if (datafellows & SSH_BUG_EXTEOF)
2425 debug("channel %d: accepting ext data after eof", id);
2427 packet_disconnect("Received extended_data after EOF "
2428 "on channel %d.", id);
2430 tcode = packet_get_int();
2432 c->extended_usage != CHAN_EXTENDED_WRITE ||
2433 tcode != SSH2_EXTENDED_DATA_STDERR) {
2434 logit("channel %d: bad ext data", c->self);
2437 data = packet_get_string(&data_len);
2439 if (data_len > c->local_window) {
2440 logit("channel %d: rcvd too much extended_data %d, win %d",
2441 c->self, data_len, c->local_window);
2445 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2446 c->local_window -= data_len;
2447 buffer_append(&c->extended, data, data_len);
2453 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2458 id = packet_get_int();
2460 c = channel_lookup(id);
2462 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2465 /* XXX force input close */
2466 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2467 debug("channel %d: FORCE input drain", c->self);
2468 c->istate = CHAN_INPUT_WAIT_DRAIN;
2469 if (buffer_len(&c->input) == 0)
2477 channel_input_close(int type, u_int32_t seq, void *ctxt)
2482 id = packet_get_int();
2484 c = channel_lookup(id);
2486 packet_disconnect("Received close for nonexistent channel %d.", id);
2489 * Send a confirmation that we have closed the channel and no more
2490 * data is coming for it.
2492 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2493 packet_put_int(c->remote_id);
2497 * If the channel is in closed state, we have sent a close request,
2498 * and the other side will eventually respond with a confirmation.
2499 * Thus, we cannot free the channel here, because then there would be
2500 * no-one to receive the confirmation. The channel gets freed when
2501 * the confirmation arrives.
2503 if (c->type != SSH_CHANNEL_CLOSED) {
2505 * Not a closed channel - mark it as draining, which will
2506 * cause it to be freed later.
2508 buffer_clear(&c->input);
2509 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2513 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2516 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2518 int id = packet_get_int();
2519 Channel *c = channel_lookup(id);
2523 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2524 chan_rcvd_oclose(c);
2529 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2531 int id = packet_get_int();
2532 Channel *c = channel_lookup(id);
2536 packet_disconnect("Received close confirmation for "
2537 "out-of-range channel %d.", id);
2538 if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
2539 packet_disconnect("Received close confirmation for "
2540 "non-closed channel %d (type %d).", id, c->type);
2546 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2551 id = packet_get_int();
2552 c = channel_lookup(id);
2554 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2555 packet_disconnect("Received open confirmation for "
2556 "non-opening channel %d.", id);
2557 remote_id = packet_get_int();
2558 /* Record the remote channel number and mark that the channel is now open. */
2559 c->remote_id = remote_id;
2560 c->type = SSH_CHANNEL_OPEN;
2563 c->remote_window = packet_get_int();
2564 c->remote_maxpacket = packet_get_int();
2565 if (c->open_confirm) {
2566 debug2("callback start");
2567 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2568 debug2("callback done");
2570 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2571 c->remote_window, c->remote_maxpacket);
2577 reason2txt(int reason)
2580 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2581 return "administratively prohibited";
2582 case SSH2_OPEN_CONNECT_FAILED:
2583 return "connect failed";
2584 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2585 return "unknown channel type";
2586 case SSH2_OPEN_RESOURCE_SHORTAGE:
2587 return "resource shortage";
2589 return "unknown reason";
2594 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2597 char *msg = NULL, *lang = NULL;
2600 id = packet_get_int();
2601 c = channel_lookup(id);
2603 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2604 packet_disconnect("Received open failure for "
2605 "non-opening channel %d.", id);
2607 reason = packet_get_int();
2608 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2609 msg = packet_get_string(NULL);
2610 lang = packet_get_string(NULL);
2612 logit("channel %d: open failed: %s%s%s", id,
2613 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2616 if (c->open_confirm) {
2617 debug2("callback start");
2618 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2619 debug2("callback done");
2623 /* Schedule the channel for cleanup/deletion. */
2629 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2638 /* Get the channel number and verify it. */
2639 id = packet_get_int();
2640 c = channel_lookup(id);
2643 logit("Received window adjust for non-open channel %d.", id);
2646 adjust = packet_get_int();
2648 debug2("channel %d: rcvd adjust %u", id, adjust);
2649 c->remote_window += adjust;
2654 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2658 char *host, *originator_string;
2661 remote_id = packet_get_int();
2662 host = packet_get_string(NULL);
2663 host_port = packet_get_int();
2665 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2666 originator_string = packet_get_string(NULL);
2668 originator_string = xstrdup("unknown (remote did not supply name)");
2671 c = channel_connect_to_port(host, host_port,
2672 "connected socket", originator_string);
2673 free(originator_string);
2676 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2677 packet_put_int(remote_id);
2680 c->remote_id = remote_id;
2685 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2688 struct channel_confirm *cc;
2691 /* Reset keepalive timeout */
2692 packet_set_alive_timeouts(0);
2694 id = packet_get_int();
2697 debug2("channel_input_status_confirm: type %d id %d", type, id);
2699 if ((c = channel_lookup(id)) == NULL) {
2700 logit("channel_input_status_confirm: %d: unknown", id);
2704 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2706 cc->cb(type, c, cc->ctx);
2707 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2708 explicit_bzero(cc, sizeof(*cc));
2712 /* -- tcp forwarding */
2715 channel_set_af(int af)
2722 * Determine whether or not a port forward listens to loopback, the
2723 * specified address or wildcard. On the client, a specified bind
2724 * address will always override gateway_ports. On the server, a
2725 * gateway_ports of 1 (``yes'') will override the client's specification
2726 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2727 * will bind to whatever address the client asked for.
2729 * Special-case listen_addrs are:
2731 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2732 * "" (empty string), "*" -> wildcard v4/v6
2733 * "localhost" -> loopback v4/v6
2734 * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
2737 channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2738 int is_client, struct ForwardOptions *fwd_opts)
2740 const char *addr = NULL;
2743 if (listen_addr == NULL) {
2744 /* No address specified: default to gateway_ports setting */
2745 if (fwd_opts->gateway_ports)
2747 } else if (fwd_opts->gateway_ports || is_client) {
2748 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2749 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2750 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2751 (!is_client && fwd_opts->gateway_ports == 1)) {
2754 * Notify client if they requested a specific listen
2755 * address and it was overridden.
2757 if (*listen_addr != '\0' &&
2758 strcmp(listen_addr, "0.0.0.0") != 0 &&
2759 strcmp(listen_addr, "*") != 0) {
2760 packet_send_debug("Forwarding listen address "
2761 "\"%s\" overridden by server "
2762 "GatewayPorts", listen_addr);
2764 } else if (strcmp(listen_addr, "localhost") != 0 ||
2765 strcmp(listen_addr, "127.0.0.1") == 0 ||
2766 strcmp(listen_addr, "::1") == 0) {
2767 /* Accept localhost address when GatewayPorts=yes */
2770 } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
2771 strcmp(listen_addr, "::1") == 0) {
2773 * If a specific IPv4/IPv6 localhost address has been
2774 * requested then accept it even if gateway_ports is in
2775 * effect. This allows the client to prefer IPv4 or IPv6.
2779 if (wildcardp != NULL)
2780 *wildcardp = wildcard;
2785 channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
2786 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
2789 int sock, r, success = 0, wildcard = 0, is_client;
2790 struct addrinfo hints, *ai, *aitop;
2791 const char *host, *addr;
2792 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2795 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2796 fwd->listen_host : fwd->connect_host;
2797 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2800 error("No forward host name.");
2803 if (strlen(host) >= NI_MAXHOST) {
2804 error("Forward host name too long.");
2808 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2809 addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
2810 is_client, fwd_opts);
2811 debug3("%s: type %d wildcard %d addr %s", __func__,
2812 type, wildcard, (addr == NULL) ? "NULL" : addr);
2815 * getaddrinfo returns a loopback address if the hostname is
2816 * set to NULL and hints.ai_flags is not AI_PASSIVE
2818 memset(&hints, 0, sizeof(hints));
2819 hints.ai_family = IPv4or6;
2820 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2821 hints.ai_socktype = SOCK_STREAM;
2822 snprintf(strport, sizeof strport, "%d", fwd->listen_port);
2823 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2825 /* This really shouldn't happen */
2826 packet_disconnect("getaddrinfo: fatal error: %s",
2827 ssh_gai_strerror(r));
2829 error("%s: getaddrinfo(%.64s): %s", __func__, addr,
2830 ssh_gai_strerror(r));
2834 if (allocated_listen_port != NULL)
2835 *allocated_listen_port = 0;
2836 for (ai = aitop; ai; ai = ai->ai_next) {
2837 switch (ai->ai_family) {
2839 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2843 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2850 * If allocating a port for -R forwards, then use the
2851 * same port for all address families.
2853 if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
2854 allocated_listen_port != NULL && *allocated_listen_port > 0)
2855 *lport_p = htons(*allocated_listen_port);
2857 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2858 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2859 error("%s: getnameinfo failed", __func__);
2862 /* Create a port to listen for the host. */
2863 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2865 /* this is no error since kernel may not support ipv6 */
2866 verbose("socket: %.100s", strerror(errno));
2870 channel_set_reuseaddr(sock);
2871 if (ai->ai_family == AF_INET6)
2872 sock_set_v6only(sock);
2874 debug("Local forwarding listening on %s port %s.",
2877 /* Bind the socket to the address. */
2878 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2879 /* address can be in use ipv6 address is already bound */
2881 error("bind: %.100s", strerror(errno));
2883 verbose("bind: %.100s", strerror(errno));
2888 /* Start listening for connections on the socket. */
2889 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2890 error("listen: %.100s", strerror(errno));
2896 * fwd->listen_port == 0 requests a dynamically allocated port -
2897 * record what we got.
2899 if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
2900 allocated_listen_port != NULL &&
2901 *allocated_listen_port == 0) {
2902 *allocated_listen_port = get_sock_port(sock, 1);
2903 debug("Allocated listen port %d",
2904 *allocated_listen_port);
2907 /* Allocate a channel number for the socket. */
2908 c = channel_new("port listener", type, sock, sock, -1,
2909 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2910 0, "port listener", 1);
2911 c->path = xstrdup(host);
2912 c->host_port = fwd->connect_port;
2913 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2914 if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
2915 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2916 c->listening_port = *allocated_listen_port;
2918 c->listening_port = fwd->listen_port;
2922 error("%s: cannot listen to port: %d", __func__,
2924 freeaddrinfo(aitop);
2929 channel_setup_fwd_listener_streamlocal(int type, struct Forward *fwd,
2930 struct ForwardOptions *fwd_opts)
2932 struct sockaddr_un sunaddr;
2939 case SSH_CHANNEL_UNIX_LISTENER:
2940 if (fwd->connect_path != NULL) {
2941 if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
2942 error("Local connecting path too long: %s",
2946 path = fwd->connect_path;
2947 port = PORT_STREAMLOCAL;
2949 if (fwd->connect_host == NULL) {
2950 error("No forward host name.");
2953 if (strlen(fwd->connect_host) >= NI_MAXHOST) {
2954 error("Forward host name too long.");
2957 path = fwd->connect_host;
2958 port = fwd->connect_port;
2961 case SSH_CHANNEL_RUNIX_LISTENER:
2962 path = fwd->listen_path;
2963 port = PORT_STREAMLOCAL;
2966 error("%s: unexpected channel type %d", __func__, type);
2970 if (fwd->listen_path == NULL) {
2971 error("No forward path name.");
2974 if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
2975 error("Local listening path too long: %s", fwd->listen_path);
2979 debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
2981 /* Start a Unix domain listener. */
2982 omask = umask(fwd_opts->streamlocal_bind_mask);
2983 sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
2984 fwd_opts->streamlocal_bind_unlink);
2989 debug("Local forwarding listening on path %s.", fwd->listen_path);
2991 /* Allocate a channel number for the socket. */
2992 c = channel_new("unix listener", type, sock, sock, -1,
2993 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2994 0, "unix listener", 1);
2995 c->path = xstrdup(path);
2996 c->host_port = port;
2997 c->listening_port = PORT_STREAMLOCAL;
2998 c->listening_addr = xstrdup(fwd->listen_path);
3003 channel_cancel_rport_listener_tcpip(const char *host, u_short port)
3008 for (i = 0; i < channels_alloc; i++) {
3009 Channel *c = channels[i];
3010 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3012 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3013 debug2("%s: close channel %d", __func__, i);
3023 channel_cancel_rport_listener_streamlocal(const char *path)
3028 for (i = 0; i < channels_alloc; i++) {
3029 Channel *c = channels[i];
3030 if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3032 if (c->path == NULL)
3034 if (strcmp(c->path, path) == 0) {
3035 debug2("%s: close channel %d", __func__, i);
3045 channel_cancel_rport_listener(struct Forward *fwd)
3047 if (fwd->listen_path != NULL)
3048 return channel_cancel_rport_listener_streamlocal(fwd->listen_path);
3050 return channel_cancel_rport_listener_tcpip(fwd->listen_host, fwd->listen_port);
3054 channel_cancel_lport_listener_tcpip(const char *lhost, u_short lport,
3055 int cport, struct ForwardOptions *fwd_opts)
3059 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
3061 for (i = 0; i < channels_alloc; i++) {
3062 Channel *c = channels[i];
3063 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
3065 if (c->listening_port != lport)
3067 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
3068 /* skip dynamic forwardings */
3069 if (c->host_port == 0)
3072 if (c->host_port != cport)
3075 if ((c->listening_addr == NULL && addr != NULL) ||
3076 (c->listening_addr != NULL && addr == NULL))
3078 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
3079 debug2("%s: close channel %d", __func__, i);
3089 channel_cancel_lport_listener_streamlocal(const char *path)
3095 error("%s: no path specified.", __func__);
3099 for (i = 0; i < channels_alloc; i++) {
3100 Channel *c = channels[i];
3101 if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
3103 if (c->listening_addr == NULL)
3105 if (strcmp(c->listening_addr, path) == 0) {
3106 debug2("%s: close channel %d", __func__, i);
3116 channel_cancel_lport_listener(struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
3118 if (fwd->listen_path != NULL)
3119 return channel_cancel_lport_listener_streamlocal(fwd->listen_path);
3121 return channel_cancel_lport_listener_tcpip(fwd->listen_host, fwd->listen_port, cport, fwd_opts);
3124 /* protocol local port fwd, used by ssh (and sshd in v1) */
3126 channel_setup_local_fwd_listener(struct Forward *fwd, struct ForwardOptions *fwd_opts)
3128 if (fwd->listen_path != NULL) {
3129 return channel_setup_fwd_listener_streamlocal(
3130 SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
3132 return channel_setup_fwd_listener_tcpip(SSH_CHANNEL_PORT_LISTENER,
3133 fwd, NULL, fwd_opts);
3137 /* protocol v2 remote port fwd, used by sshd */
3139 channel_setup_remote_fwd_listener(struct Forward *fwd,
3140 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
3142 if (fwd->listen_path != NULL) {
3143 return channel_setup_fwd_listener_streamlocal(
3144 SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
3146 return channel_setup_fwd_listener_tcpip(
3147 SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
3153 * Translate the requested rfwd listen host to something usable for
3157 channel_rfwd_bind_host(const char *listen_host)
3159 if (listen_host == NULL) {
3160 if (datafellows & SSH_BUG_RFWD_ADDR)
3164 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3165 if (datafellows & SSH_BUG_RFWD_ADDR)
3174 * Initiate forwarding of connections to port "port" on remote host through
3175 * the secure channel to host:port from local side.
3176 * Returns handle (index) for updating the dynamic listen port with
3177 * channel_update_permitted_opens().
3180 channel_request_remote_forwarding(struct Forward *fwd)
3182 int type, success = 0, idx = -1;
3184 /* Send the forward request to the remote side. */
3186 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3187 if (fwd->listen_path != NULL) {
3188 packet_put_cstring("streamlocal-forward@openssh.com");
3189 packet_put_char(1); /* boolean: want reply */
3190 packet_put_cstring(fwd->listen_path);
3192 packet_put_cstring("tcpip-forward");
3193 packet_put_char(1); /* boolean: want reply */
3194 packet_put_cstring(channel_rfwd_bind_host(fwd->listen_host));
3195 packet_put_int(fwd->listen_port);
3198 packet_write_wait();
3199 /* Assume that server accepts the request */
3201 } else if (fwd->listen_path == NULL) {
3202 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
3203 packet_put_int(fwd->listen_port);
3204 packet_put_cstring(fwd->connect_host);
3205 packet_put_int(fwd->connect_port);
3207 packet_write_wait();
3209 /* Wait for response from the remote side. */
3210 type = packet_read();
3212 case SSH_SMSG_SUCCESS:
3215 case SSH_SMSG_FAILURE:
3218 /* Unknown packet */
3219 packet_disconnect("Protocol error for port forward request:"
3220 "received packet type %d.", type);
3223 logit("Warning: Server does not support remote stream local forwarding.");
3226 /* Record that connection to this host/port is permitted. */
3227 permitted_opens = xrealloc(permitted_opens,
3228 num_permitted_opens + 1, sizeof(*permitted_opens));
3229 idx = num_permitted_opens++;
3230 if (fwd->connect_path != NULL) {
3231 permitted_opens[idx].host_to_connect =
3232 xstrdup(fwd->connect_path);
3233 permitted_opens[idx].port_to_connect =
3236 permitted_opens[idx].host_to_connect =
3237 xstrdup(fwd->connect_host);
3238 permitted_opens[idx].port_to_connect =
3241 if (fwd->listen_path != NULL) {
3242 permitted_opens[idx].listen_host = NULL;
3243 permitted_opens[idx].listen_path =
3244 xstrdup(fwd->listen_path);
3245 permitted_opens[idx].listen_port = PORT_STREAMLOCAL;
3247 permitted_opens[idx].listen_host =
3248 fwd->listen_host ? xstrdup(fwd->listen_host) : NULL;
3249 permitted_opens[idx].listen_path = NULL;
3250 permitted_opens[idx].listen_port = fwd->listen_port;
3257 open_match(ForwardPermission *allowed_open, const char *requestedhost,
3260 if (allowed_open->host_to_connect == NULL)
3262 if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
3263 allowed_open->port_to_connect != requestedport)
3265 if (strcmp(allowed_open->host_to_connect, requestedhost) != 0)
3271 * Note that in the listen host/port case
3272 * we don't support FWD_PERMIT_ANY_PORT and
3273 * need to translate between the configured-host (listen_host)
3274 * and what we've sent to the remote server (channel_rfwd_bind_host)
3277 open_listen_match_tcpip(ForwardPermission *allowed_open,
3278 const char *requestedhost, u_short requestedport, int translate)
3280 const char *allowed_host;
3282 if (allowed_open->host_to_connect == NULL)
3284 if (allowed_open->listen_port != requestedport)
3286 if (!translate && allowed_open->listen_host == NULL &&
3287 requestedhost == NULL)
3289 allowed_host = translate ?
3290 channel_rfwd_bind_host(allowed_open->listen_host) :
3291 allowed_open->listen_host;
3292 if (allowed_host == NULL ||
3293 strcmp(allowed_host, requestedhost) != 0)
3299 open_listen_match_streamlocal(ForwardPermission *allowed_open,
3300 const char *requestedpath)
3302 if (allowed_open->host_to_connect == NULL)
3304 if (allowed_open->listen_port != PORT_STREAMLOCAL)
3306 if (allowed_open->listen_path == NULL ||
3307 strcmp(allowed_open->listen_path, requestedpath) != 0)
3313 * Request cancellation of remote forwarding of connection host:port from
3317 channel_request_rforward_cancel_tcpip(const char *host, u_short port)
3324 for (i = 0; i < num_permitted_opens; i++) {
3325 if (open_listen_match_tcpip(&permitted_opens[i], host, port, 0))
3328 if (i >= num_permitted_opens) {
3329 debug("%s: requested forward not found", __func__);
3332 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3333 packet_put_cstring("cancel-tcpip-forward");
3335 packet_put_cstring(channel_rfwd_bind_host(host));
3336 packet_put_int(port);
3339 permitted_opens[i].listen_port = 0;
3340 permitted_opens[i].port_to_connect = 0;
3341 free(permitted_opens[i].host_to_connect);
3342 permitted_opens[i].host_to_connect = NULL;
3343 free(permitted_opens[i].listen_host);
3344 permitted_opens[i].listen_host = NULL;
3345 permitted_opens[i].listen_path = NULL;
3351 * Request cancellation of remote forwarding of Unix domain socket
3352 * path from local side.
3355 channel_request_rforward_cancel_streamlocal(const char *path)
3362 for (i = 0; i < num_permitted_opens; i++) {
3363 if (open_listen_match_streamlocal(&permitted_opens[i], path))
3366 if (i >= num_permitted_opens) {
3367 debug("%s: requested forward not found", __func__);
3370 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3371 packet_put_cstring("cancel-streamlocal-forward@openssh.com");
3373 packet_put_cstring(path);
3376 permitted_opens[i].listen_port = 0;
3377 permitted_opens[i].port_to_connect = 0;
3378 free(permitted_opens[i].host_to_connect);
3379 permitted_opens[i].host_to_connect = NULL;
3380 permitted_opens[i].listen_host = NULL;
3381 free(permitted_opens[i].listen_path);
3382 permitted_opens[i].listen_path = NULL;
3388 * Request cancellation of remote forwarding of a connection from local side.
3391 channel_request_rforward_cancel(struct Forward *fwd)
3393 if (fwd->listen_path != NULL) {
3394 return (channel_request_rforward_cancel_streamlocal(
3397 return (channel_request_rforward_cancel_tcpip(fwd->listen_host,
3398 fwd->listen_port ? fwd->listen_port : fwd->allocated_port));
3403 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3404 * listening for the port, and sends back a success reply (or disconnect
3405 * message if there was an error).
3408 channel_input_port_forward_request(int is_root, struct ForwardOptions *fwd_opts)
3413 /* Get arguments from the packet. */
3414 memset(&fwd, 0, sizeof(fwd));
3415 fwd.listen_port = packet_get_int();
3416 fwd.connect_host = packet_get_string(NULL);
3417 fwd.connect_port = packet_get_int();
3421 * Check that an unprivileged user is not trying to forward a
3424 if (fwd.listen_port < IPPORT_RESERVED && !is_root)
3426 "Requested forwarding of port %d but user is not root.",
3428 if (fwd.connect_port == 0)
3429 packet_disconnect("Dynamic forwarding denied.");
3432 /* Initiate forwarding */
3433 success = channel_setup_local_fwd_listener(&fwd, fwd_opts);
3435 /* Free the argument string. */
3436 free(fwd.connect_host);
3438 return (success ? 0 : -1);
3442 * Permits opening to any host/port if permitted_opens[] is empty. This is
3443 * usually called by the server, because the user could connect to any port
3444 * anyway, and the server has no way to know but to trust the client anyway.
3447 channel_permit_all_opens(void)
3449 if (num_permitted_opens == 0)
3450 all_opens_permitted = 1;
3454 channel_add_permitted_opens(char *host, int port)
3456 debug("allow port forwarding to host %s port %d", host, port);
3458 permitted_opens = xrealloc(permitted_opens,
3459 num_permitted_opens + 1, sizeof(*permitted_opens));
3460 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3461 permitted_opens[num_permitted_opens].port_to_connect = port;
3462 permitted_opens[num_permitted_opens].listen_host = NULL;
3463 permitted_opens[num_permitted_opens].listen_path = NULL;
3464 permitted_opens[num_permitted_opens].listen_port = 0;
3465 num_permitted_opens++;
3467 all_opens_permitted = 0;
3471 * Update the listen port for a dynamic remote forward, after
3472 * the actual 'newport' has been allocated. If 'newport' < 0 is
3473 * passed then they entry will be invalidated.
3476 channel_update_permitted_opens(int idx, int newport)
3478 if (idx < 0 || idx >= num_permitted_opens) {
3479 debug("channel_update_permitted_opens: index out of range:"
3480 " %d num_permitted_opens %d", idx, num_permitted_opens);
3483 debug("%s allowed port %d for forwarding to host %s port %d",
3484 newport > 0 ? "Updating" : "Removing",
3486 permitted_opens[idx].host_to_connect,
3487 permitted_opens[idx].port_to_connect);
3489 permitted_opens[idx].listen_port =
3490 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3492 permitted_opens[idx].listen_port = 0;
3493 permitted_opens[idx].port_to_connect = 0;
3494 free(permitted_opens[idx].host_to_connect);
3495 permitted_opens[idx].host_to_connect = NULL;
3496 free(permitted_opens[idx].listen_host);
3497 permitted_opens[idx].listen_host = NULL;
3498 free(permitted_opens[idx].listen_path);
3499 permitted_opens[idx].listen_path = NULL;
3504 channel_add_adm_permitted_opens(char *host, int port)
3506 debug("config allows port forwarding to host %s port %d", host, port);
3508 permitted_adm_opens = xrealloc(permitted_adm_opens,
3509 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3510 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3512 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3513 permitted_adm_opens[num_adm_permitted_opens].listen_host = NULL;
3514 permitted_adm_opens[num_adm_permitted_opens].listen_path = NULL;
3515 permitted_adm_opens[num_adm_permitted_opens].listen_port = 0;
3516 return ++num_adm_permitted_opens;
3520 channel_disable_adm_local_opens(void)
3522 channel_clear_adm_permitted_opens();
3523 permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3524 permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3525 num_adm_permitted_opens = 1;
3529 channel_clear_permitted_opens(void)
3533 for (i = 0; i < num_permitted_opens; i++) {
3534 free(permitted_opens[i].host_to_connect);
3535 free(permitted_opens[i].listen_host);
3536 free(permitted_opens[i].listen_path);
3538 free(permitted_opens);
3539 permitted_opens = NULL;
3540 num_permitted_opens = 0;
3544 channel_clear_adm_permitted_opens(void)
3548 for (i = 0; i < num_adm_permitted_opens; i++) {
3549 free(permitted_adm_opens[i].host_to_connect);
3550 free(permitted_adm_opens[i].listen_host);
3551 free(permitted_adm_opens[i].listen_path);
3553 free(permitted_adm_opens);
3554 permitted_adm_opens = NULL;
3555 num_adm_permitted_opens = 0;
3559 channel_print_adm_permitted_opens(void)
3563 printf("permitopen");
3564 if (num_adm_permitted_opens == 0) {
3568 for (i = 0; i < num_adm_permitted_opens; i++)
3569 if (permitted_adm_opens[i].host_to_connect == NULL)
3572 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3573 permitted_adm_opens[i].port_to_connect);
3577 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3579 permitopen_port(const char *p)
3583 if (strcmp(p, "*") == 0)
3584 return FWD_PERMIT_ANY_PORT;
3585 if ((port = a2port(p)) > 0)
3590 /* Try to start non-blocking connect to next host in cctx list */
3592 connect_next(struct channel_connect *cctx)
3594 int sock, saved_errno;
3595 struct sockaddr_un *sunaddr;
3596 char ntop[NI_MAXHOST], strport[MAX(NI_MAXSERV,sizeof(sunaddr->sun_path))];
3598 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3599 switch (cctx->ai->ai_family) {
3601 /* unix:pathname instead of host:port */
3602 sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
3603 strlcpy(ntop, "unix", sizeof(ntop));
3604 strlcpy(strport, sunaddr->sun_path, sizeof(strport));
3608 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3609 ntop, sizeof(ntop), strport, sizeof(strport),
3610 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3611 error("connect_next: getnameinfo failed");
3618 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3619 cctx->ai->ai_protocol)) == -1) {
3620 if (cctx->ai->ai_next == NULL)
3621 error("socket: %.100s", strerror(errno));
3623 verbose("socket: %.100s", strerror(errno));
3626 if (set_nonblock(sock) == -1)
3627 fatal("%s: set_nonblock(%d)", __func__, sock);
3628 if (connect(sock, cctx->ai->ai_addr,
3629 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3630 debug("connect_next: host %.100s ([%.100s]:%s): "
3631 "%.100s", cctx->host, ntop, strport,
3633 saved_errno = errno;
3635 errno = saved_errno;
3636 continue; /* fail -- try next */
3638 if (cctx->ai->ai_family != AF_UNIX)
3640 debug("connect_next: host %.100s ([%.100s]:%s) "
3641 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3642 cctx->ai = cctx->ai->ai_next;
3649 channel_connect_ctx_free(struct channel_connect *cctx)
3653 if (cctx->aitop->ai_family == AF_UNIX)
3656 freeaddrinfo(cctx->aitop);
3658 memset(cctx, 0, sizeof(*cctx));
3661 /* Return CONNECTING channel to remote host:port or local socket path */
3663 connect_to(const char *name, int port, char *ctype, char *rname)
3665 struct addrinfo hints;
3668 char strport[NI_MAXSERV];
3669 struct channel_connect cctx;
3672 memset(&cctx, 0, sizeof(cctx));
3674 if (port == PORT_STREAMLOCAL) {
3675 struct sockaddr_un *sunaddr;
3676 struct addrinfo *ai;
3678 if (strlen(name) > sizeof(sunaddr->sun_path)) {
3679 error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
3684 * Fake up a struct addrinfo for AF_UNIX connections.
3685 * channel_connect_ctx_free() must check ai_family
3686 * and use free() not freeaddirinfo() for AF_UNIX.
3688 ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
3689 memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
3690 ai->ai_addr = (struct sockaddr *)(ai + 1);
3691 ai->ai_addrlen = sizeof(*sunaddr);
3692 ai->ai_family = AF_UNIX;
3693 ai->ai_socktype = SOCK_STREAM;
3694 ai->ai_protocol = PF_UNSPEC;
3695 sunaddr = (struct sockaddr_un *)ai->ai_addr;
3696 sunaddr->sun_family = AF_UNIX;
3697 strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
3700 memset(&hints, 0, sizeof(hints));
3701 hints.ai_family = IPv4or6;
3702 hints.ai_socktype = SOCK_STREAM;
3703 snprintf(strport, sizeof strport, "%d", port);
3704 if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop)) != 0) {
3705 error("connect_to %.100s: unknown host (%s)", name,
3706 ssh_gai_strerror(gaierr));
3711 cctx.host = xstrdup(name);
3713 cctx.ai = cctx.aitop;
3715 if ((sock = connect_next(&cctx)) == -1) {
3716 error("connect to %.100s port %d failed: %s",
3717 name, port, strerror(errno));
3718 channel_connect_ctx_free(&cctx);
3721 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3722 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3723 c->connect_ctx = cctx;
3728 channel_connect_by_listen_address(const char *listen_host,
3729 u_short listen_port, char *ctype, char *rname)
3733 for (i = 0; i < num_permitted_opens; i++) {
3734 if (open_listen_match_tcpip(&permitted_opens[i], listen_host,
3737 permitted_opens[i].host_to_connect,
3738 permitted_opens[i].port_to_connect, ctype, rname);
3741 error("WARNING: Server requests forwarding for unknown listen_port %d",
3747 channel_connect_by_listen_path(const char *path, char *ctype, char *rname)
3751 for (i = 0; i < num_permitted_opens; i++) {
3752 if (open_listen_match_streamlocal(&permitted_opens[i], path)) {
3754 permitted_opens[i].host_to_connect,
3755 permitted_opens[i].port_to_connect, ctype, rname);
3758 error("WARNING: Server requests forwarding for unknown path %.100s",
3763 /* Check if connecting to that port is permitted and connect. */
3765 channel_connect_to_port(const char *host, u_short port, char *ctype, char *rname)
3767 int i, permit, permit_adm = 1;
3769 permit = all_opens_permitted;
3771 for (i = 0; i < num_permitted_opens; i++)
3772 if (open_match(&permitted_opens[i], host, port)) {
3778 if (num_adm_permitted_opens > 0) {
3780 for (i = 0; i < num_adm_permitted_opens; i++)
3781 if (open_match(&permitted_adm_opens[i], host, port)) {
3787 if (!permit || !permit_adm) {
3788 logit("Received request to connect to host %.100s port %d, "
3789 "but the request was denied.", host, port);
3792 return connect_to(host, port, ctype, rname);
3795 /* Check if connecting to that path is permitted and connect. */
3797 channel_connect_to_path(const char *path, char *ctype, char *rname)
3799 int i, permit, permit_adm = 1;
3801 permit = all_opens_permitted;
3803 for (i = 0; i < num_permitted_opens; i++)
3804 if (open_match(&permitted_opens[i], path, PORT_STREAMLOCAL)) {
3810 if (num_adm_permitted_opens > 0) {
3812 for (i = 0; i < num_adm_permitted_opens; i++)
3813 if (open_match(&permitted_adm_opens[i], path, PORT_STREAMLOCAL)) {
3819 if (!permit || !permit_adm) {
3820 logit("Received request to connect to path %.100s, "
3821 "but the request was denied.", path);
3824 return connect_to(path, PORT_STREAMLOCAL, ctype, rname);
3828 channel_send_window_changes(void)
3833 for (i = 0; i < channels_alloc; i++) {
3834 if (channels[i] == NULL || !channels[i]->client_tty ||
3835 channels[i]->type != SSH_CHANNEL_OPEN)
3837 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3839 channel_request_start(i, "window-change", 0);
3840 packet_put_int((u_int)ws.ws_col);
3841 packet_put_int((u_int)ws.ws_row);
3842 packet_put_int((u_int)ws.ws_xpixel);
3843 packet_put_int((u_int)ws.ws_ypixel);
3848 /* -- X11 forwarding */
3851 * Creates an internet domain socket for listening for X11 connections.
3852 * Returns 0 and a suitable display number for the DISPLAY variable
3853 * stored in display_numberp , or -1 if an error occurs.
3856 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3857 int single_connection, u_int *display_numberp, int **chanids)
3860 int display_number, sock;
3862 struct addrinfo hints, *ai, *aitop;
3863 char strport[NI_MAXSERV];
3864 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3866 if (chanids == NULL)
3869 for (display_number = x11_display_offset;
3870 display_number < MAX_DISPLAYS;
3872 port = 6000 + display_number;
3873 memset(&hints, 0, sizeof(hints));
3874 hints.ai_family = IPv4or6;
3875 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3876 hints.ai_socktype = SOCK_STREAM;
3877 snprintf(strport, sizeof strport, "%d", port);
3878 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3879 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3882 for (ai = aitop; ai; ai = ai->ai_next) {
3883 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3885 sock = socket(ai->ai_family, ai->ai_socktype,
3888 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3890 && (errno != EPFNOSUPPORT)
3893 error("socket: %.100s", strerror(errno));
3894 freeaddrinfo(aitop);
3897 debug("x11_create_display_inet: Socket family %d not supported",
3902 if (ai->ai_family == AF_INET6)
3903 sock_set_v6only(sock);
3904 if (x11_use_localhost)
3905 channel_set_reuseaddr(sock);
3906 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3907 debug2("bind port %d: %.100s", port, strerror(errno));
3910 for (n = 0; n < num_socks; n++) {
3916 socks[num_socks++] = sock;
3917 if (num_socks == NUM_SOCKS)
3920 freeaddrinfo(aitop);
3924 if (display_number >= MAX_DISPLAYS) {
3925 error("Failed to allocate internet-domain X11 display socket.");
3928 /* Start listening for connections on the socket. */
3929 for (n = 0; n < num_socks; n++) {
3931 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3932 error("listen: %.100s", strerror(errno));
3938 /* Allocate a channel for each socket. */
3939 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3940 for (n = 0; n < num_socks; n++) {
3942 nc = channel_new("x11 listener",
3943 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3944 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3945 0, "X11 inet listener", 1);
3946 nc->single_connection = single_connection;
3947 (*chanids)[n] = nc->self;
3951 /* Return the display number for the DISPLAY environment variable. */
3952 *display_numberp = display_number;
3957 connect_local_xsocket_path(const char *pathname)
3960 struct sockaddr_un addr;
3962 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3964 error("socket: %.100s", strerror(errno));
3965 memset(&addr, 0, sizeof(addr));
3966 addr.sun_family = AF_UNIX;
3967 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3968 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3971 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3976 connect_local_xsocket(u_int dnr)
3979 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3980 return connect_local_xsocket_path(buf);
3984 x11_connect_display(void)
3986 u_int display_number;
3987 const char *display;
3988 char buf[1024], *cp;
3989 struct addrinfo hints, *ai, *aitop;
3990 char strport[NI_MAXSERV];
3991 int gaierr, sock = 0;
3993 /* Try to open a socket for the local X server. */
3994 display = getenv("DISPLAY");
3996 error("DISPLAY not set.");
4000 * Now we decode the value of the DISPLAY variable and make a
4001 * connection to the real X server.
4004 /* Check if the display is from launchd. */
4006 if (strncmp(display, "/tmp/launch", 11) == 0) {
4007 sock = connect_local_xsocket_path(display);
4011 /* OK, we now have a connection to the display. */
4016 * Check if it is a unix domain socket. Unix domain displays are in
4017 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
4019 if (strncmp(display, "unix:", 5) == 0 ||
4020 display[0] == ':') {
4021 /* Connect to the unix domain socket. */
4022 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
4023 error("Could not parse display number from DISPLAY: %.100s",
4027 /* Create a socket. */
4028 sock = connect_local_xsocket(display_number);
4032 /* OK, we now have a connection to the display. */
4036 * Connect to an inet socket. The DISPLAY value is supposedly
4037 * hostname:d[.s], where hostname may also be numeric IP address.
4039 strlcpy(buf, display, sizeof(buf));
4040 cp = strchr(buf, ':');
4042 error("Could not find ':' in DISPLAY: %.100s", display);
4046 /* buf now contains the host name. But first we parse the display number. */
4047 if (sscanf(cp + 1, "%u", &display_number) != 1) {
4048 error("Could not parse display number from DISPLAY: %.100s",
4053 /* Look up the host address */
4054 memset(&hints, 0, sizeof(hints));
4055 hints.ai_family = IPv4or6;
4056 hints.ai_socktype = SOCK_STREAM;
4057 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
4058 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
4059 error("%.100s: unknown host. (%s)", buf,
4060 ssh_gai_strerror(gaierr));
4063 for (ai = aitop; ai; ai = ai->ai_next) {
4064 /* Create a socket. */
4065 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
4067 debug2("socket: %.100s", strerror(errno));
4070 /* Connect it to the display. */
4071 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4072 debug2("connect %.100s port %u: %.100s", buf,
4073 6000 + display_number, strerror(errno));
4080 freeaddrinfo(aitop);
4082 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
4091 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
4092 * the remote channel number. We should do whatever we want, and respond
4093 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
4098 x11_input_open(int type, u_int32_t seq, void *ctxt)
4101 int remote_id, sock = 0;
4104 debug("Received X11 open request.");
4106 remote_id = packet_get_int();
4108 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
4109 remote_host = packet_get_string(NULL);
4111 remote_host = xstrdup("unknown (remote did not supply name)");
4115 /* Obtain a connection to the real X display. */
4116 sock = x11_connect_display();
4118 /* Allocate a channel for this connection. */
4119 c = channel_new("connected x11 socket",
4120 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
4122 c->remote_id = remote_id;
4127 /* Send refusal to the remote host. */
4128 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
4129 packet_put_int(remote_id);
4131 /* Send a confirmation to the remote host. */
4132 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
4133 packet_put_int(remote_id);
4134 packet_put_int(c->self);
4139 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
4142 deny_input_open(int type, u_int32_t seq, void *ctxt)
4144 int rchan = packet_get_int();
4147 case SSH_SMSG_AGENT_OPEN:
4148 error("Warning: ssh server tried agent forwarding.");
4150 case SSH_SMSG_X11_OPEN:
4151 error("Warning: ssh server tried X11 forwarding.");
4154 error("deny_input_open: type %d", type);
4157 error("Warning: this is probably a break-in attempt by a malicious server.");
4158 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
4159 packet_put_int(rchan);
4164 * Requests forwarding of X11 connections, generates fake authentication
4165 * data, and enables authentication spoofing.
4166 * This should be called in the client only.
4169 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
4170 const char *proto, const char *data, int want_reply)
4172 u_int data_len = (u_int) strlen(data) / 2;
4179 if (x11_saved_display == NULL)
4180 x11_saved_display = xstrdup(disp);
4181 else if (strcmp(disp, x11_saved_display) != 0) {
4182 error("x11_request_forwarding_with_spoofing: different "
4183 "$DISPLAY already forwarded");
4187 cp = strchr(disp, ':');
4189 cp = strchr(cp, '.');
4191 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
4195 if (x11_saved_proto == NULL) {
4196 /* Save protocol name. */
4197 x11_saved_proto = xstrdup(proto);
4199 * Extract real authentication data and generate fake data
4200 * of the same length.
4202 x11_saved_data = xmalloc(data_len);
4203 x11_fake_data = xmalloc(data_len);
4204 for (i = 0; i < data_len; i++) {
4205 if (sscanf(data + 2 * i, "%2x", &value) != 1)
4206 fatal("x11_request_forwarding: bad "
4207 "authentication data: %.100s", data);
4210 x11_saved_data[i] = value;
4211 x11_fake_data[i] = rnd & 0xff;
4214 x11_saved_data_len = data_len;
4215 x11_fake_data_len = data_len;
4218 /* Convert the fake data into hex. */
4219 new_data = tohex(x11_fake_data, data_len);
4221 /* Send the request packet. */
4223 channel_request_start(client_session_id, "x11-req", want_reply);
4224 packet_put_char(0); /* XXX bool single connection */
4226 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
4228 packet_put_cstring(proto);
4229 packet_put_cstring(new_data);
4230 packet_put_int(screen_number);
4232 packet_write_wait();
4237 /* -- agent forwarding */
4239 /* Sends a message to the server to request authentication fd forwarding. */
4242 auth_request_forwarding(void)
4244 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
4246 packet_write_wait();