1 /* $OpenBSD: channels.c,v 1.318 2012/04/23 08:18:17 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * This file contains functions for generic socket connection forwarding.
7 * There is also code for initiating connection forwarding for X11 connections,
8 * arbitrary tcp/ip connections, and the authentication agent connection.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 support added by Markus Friedl.
17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Copyright (c) 1999 Dug Song. All rights reserved.
19 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 #include <sys/types.h>
45 #include <sys/ioctl.h>
47 #include <sys/socket.h>
48 #ifdef HAVE_SYS_TIME_H
49 # include <sys/time.h>
52 #include <netinet/in.h>
53 #include <arpa/inet.h>
65 #include "openbsd-compat/sys-queue.h"
79 #include "pathnames.h"
84 * Pointer to an array containing all allocated channels. The array is
85 * dynamically extended as needed.
87 static Channel **channels = NULL;
90 * Size of the channel array. All slots of the array must always be
91 * initialized (at least the type field); unused slots set to NULL
93 static u_int channels_alloc = 0;
96 * Maximum file descriptor value used in any of the channels. This is
97 * updated in channel_new.
99 static int channel_max_fd = 0;
102 /* -- tcp forwarding */
105 * Data structure for storing which hosts are permitted for forward requests.
106 * The local sides of any remote forwards are stored in this array to prevent
107 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
108 * network (which might be behind a firewall).
111 char *host_to_connect; /* Connect to 'host'. */
112 u_short port_to_connect; /* Connect to 'port'. */
113 u_short listen_port; /* Remote side should listen port number. */
116 /* List of all permitted host/port pairs to connect by the user. */
117 static ForwardPermission *permitted_opens = NULL;
119 /* List of all permitted host/port pairs to connect by the admin. */
120 static ForwardPermission *permitted_adm_opens = NULL;
122 /* Number of permitted host/port pairs in the array permitted by the user. */
123 static int num_permitted_opens = 0;
125 /* Number of permitted host/port pair in the array permitted by the admin. */
126 static int num_adm_permitted_opens = 0;
128 /* special-case port number meaning allow any port */
129 #define FWD_PERMIT_ANY_PORT 0
132 * If this is true, all opens are permitted. This is the case on the server
133 * on which we have to trust the client anyway, and the user could do
134 * anything after logging in anyway.
136 static int all_opens_permitted = 0;
139 /* -- X11 forwarding */
141 /* Maximum number of fake X11 displays to try. */
142 #define MAX_DISPLAYS 1000
144 /* Saved X11 local (client) display. */
145 static char *x11_saved_display = NULL;
147 /* Saved X11 authentication protocol name. */
148 static char *x11_saved_proto = NULL;
150 /* Saved X11 authentication data. This is the real data. */
151 static char *x11_saved_data = NULL;
152 static u_int x11_saved_data_len = 0;
155 * Fake X11 authentication data. This is what the server will be sending us;
156 * we should replace any occurrences of this by the real data.
158 static u_char *x11_fake_data = NULL;
159 static u_int x11_fake_data_len;
162 /* -- agent forwarding */
166 /* AF_UNSPEC or AF_INET or AF_INET6 */
167 static int IPv4or6 = AF_UNSPEC;
170 static void port_open_helper(Channel *c, char *rtype);
172 /* non-blocking connect helpers */
173 static int connect_next(struct channel_connect *);
174 static void channel_connect_ctx_free(struct channel_connect *);
176 /* -- channel core */
179 channel_by_id(int id)
183 if (id < 0 || (u_int)id >= channels_alloc) {
184 logit("channel_by_id: %d: bad id", id);
189 logit("channel_by_id: %d: bad id: channel free", id);
196 * Returns the channel if it is allowed to receive protocol messages.
197 * Private channels, like listening sockets, may not receive messages.
200 channel_lookup(int id)
204 if ((c = channel_by_id(id)) == NULL)
208 case SSH_CHANNEL_X11_OPEN:
209 case SSH_CHANNEL_LARVAL:
210 case SSH_CHANNEL_CONNECTING:
211 case SSH_CHANNEL_DYNAMIC:
212 case SSH_CHANNEL_OPENING:
213 case SSH_CHANNEL_OPEN:
214 case SSH_CHANNEL_INPUT_DRAINING:
215 case SSH_CHANNEL_OUTPUT_DRAINING:
218 logit("Non-public channel %d, type %d.", id, c->type);
223 * Register filedescriptors for a channel, used when allocating a channel or
224 * when the channel consumer/producer is ready, e.g. shell exec'd
227 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
228 int extusage, int nonblock, int is_tty)
230 /* Update the maximum file descriptor value. */
231 channel_max_fd = MAX(channel_max_fd, rfd);
232 channel_max_fd = MAX(channel_max_fd, wfd);
233 channel_max_fd = MAX(channel_max_fd, efd);
236 fcntl(rfd, F_SETFD, FD_CLOEXEC);
237 if (wfd != -1 && wfd != rfd)
238 fcntl(wfd, F_SETFD, FD_CLOEXEC);
239 if (efd != -1 && efd != rfd && efd != wfd)
240 fcntl(efd, F_SETFD, FD_CLOEXEC);
244 c->sock = (rfd == wfd) ? rfd : -1;
246 c->extended_usage = extusage;
248 if ((c->isatty = is_tty) != 0)
249 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
250 c->wfd_isatty = is_tty || isatty(c->wfd);
252 /* enable nonblocking mode */
264 * Allocate a new channel object and set its type and socket. This will cause
265 * remote_name to be freed.
268 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
269 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
275 /* Do initial allocation if this is the first call. */
276 if (channels_alloc == 0) {
278 channels = xcalloc(channels_alloc, sizeof(Channel *));
279 for (i = 0; i < channels_alloc; i++)
282 /* Try to find a free slot where to put the new channel. */
283 for (found = -1, i = 0; i < channels_alloc; i++)
284 if (channels[i] == NULL) {
285 /* Found a free slot. */
290 /* There are no free slots. Take last+1 slot and expand the array. */
291 found = channels_alloc;
292 if (channels_alloc > 10000)
293 fatal("channel_new: internal error: channels_alloc %d "
294 "too big.", channels_alloc);
295 channels = xrealloc(channels, channels_alloc + 10,
297 channels_alloc += 10;
298 debug2("channel: expanding %d", channels_alloc);
299 for (i = found; i < channels_alloc; i++)
302 /* Initialize and return new channel. */
303 c = channels[found] = xcalloc(1, sizeof(Channel));
304 buffer_init(&c->input);
305 buffer_init(&c->output);
306 buffer_init(&c->extended);
308 c->listening_addr = NULL;
309 c->listening_port = 0;
310 c->ostate = CHAN_OUTPUT_OPEN;
311 c->istate = CHAN_INPUT_OPEN;
313 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
318 c->local_window = window;
319 c->local_window_max = window;
320 c->local_consumed = 0;
321 c->local_maxpacket = maxpack;
323 c->remote_name = xstrdup(remote_name);
324 c->remote_window = 0;
325 c->remote_maxpacket = 0;
327 c->single_connection = 0;
328 c->detach_user = NULL;
330 c->open_confirm = NULL;
331 c->open_confirm_ctx = NULL;
332 c->input_filter = NULL;
333 c->output_filter = NULL;
334 c->filter_ctx = NULL;
335 c->filter_cleanup = NULL;
340 c->delayed = 1; /* prevent call to channel_post handler */
341 TAILQ_INIT(&c->status_confirms);
342 debug("channel %d: new [%s]", found, remote_name);
347 channel_find_maxfd(void)
353 for (i = 0; i < channels_alloc; i++) {
356 max = MAX(max, c->rfd);
357 max = MAX(max, c->wfd);
358 max = MAX(max, c->efd);
365 channel_close_fd(int *fdp)
367 int ret = 0, fd = *fdp;
372 if (fd == channel_max_fd)
373 channel_max_fd = channel_find_maxfd();
378 /* Close all channel fd/socket. */
380 channel_close_fds(Channel *c)
382 channel_close_fd(&c->sock);
383 channel_close_fd(&c->rfd);
384 channel_close_fd(&c->wfd);
385 channel_close_fd(&c->efd);
388 /* Free the channel and close its fd/socket. */
390 channel_free(Channel *c)
394 struct channel_confirm *cc;
396 for (n = 0, i = 0; i < channels_alloc; i++)
399 debug("channel %d: free: %s, nchannels %u", c->self,
400 c->remote_name ? c->remote_name : "???", n);
402 s = channel_open_message();
403 debug3("channel %d: status: %s", c->self, s);
407 shutdown(c->sock, SHUT_RDWR);
408 channel_close_fds(c);
409 buffer_free(&c->input);
410 buffer_free(&c->output);
411 buffer_free(&c->extended);
412 if (c->remote_name) {
413 xfree(c->remote_name);
414 c->remote_name = NULL;
420 if (c->listening_addr) {
421 xfree(c->listening_addr);
422 c->listening_addr = NULL;
424 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
425 if (cc->abandon_cb != NULL)
426 cc->abandon_cb(c, cc->ctx);
427 TAILQ_REMOVE(&c->status_confirms, cc, entry);
428 bzero(cc, sizeof(*cc));
431 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
432 c->filter_cleanup(c->self, c->filter_ctx);
433 channels[c->self] = NULL;
438 channel_free_all(void)
442 for (i = 0; i < channels_alloc; i++)
443 if (channels[i] != NULL)
444 channel_free(channels[i]);
448 * Closes the sockets/fds of all channels. This is used to close extra file
449 * descriptors after a fork.
452 channel_close_all(void)
456 for (i = 0; i < channels_alloc; i++)
457 if (channels[i] != NULL)
458 channel_close_fds(channels[i]);
462 * Stop listening to channels.
465 channel_stop_listening(void)
470 for (i = 0; i < channels_alloc; i++) {
474 case SSH_CHANNEL_AUTH_SOCKET:
475 case SSH_CHANNEL_PORT_LISTENER:
476 case SSH_CHANNEL_RPORT_LISTENER:
477 case SSH_CHANNEL_X11_LISTENER:
478 channel_close_fd(&c->sock);
487 * Returns true if no channel has too much buffered data, and false if one or
488 * more channel is overfull.
491 channel_not_very_much_buffered_data(void)
496 for (i = 0; i < channels_alloc; i++) {
498 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
501 buffer_len(&c->input) > packet_get_maxsize()) {
502 debug2("channel %d: big input buffer %d",
503 c->self, buffer_len(&c->input));
507 if (buffer_len(&c->output) > packet_get_maxsize()) {
508 debug2("channel %d: big output buffer %u > %u",
509 c->self, buffer_len(&c->output),
510 packet_get_maxsize());
518 /* Returns true if any channel is still open. */
520 channel_still_open(void)
525 for (i = 0; i < channels_alloc; i++) {
530 case SSH_CHANNEL_X11_LISTENER:
531 case SSH_CHANNEL_PORT_LISTENER:
532 case SSH_CHANNEL_RPORT_LISTENER:
533 case SSH_CHANNEL_MUX_LISTENER:
534 case SSH_CHANNEL_CLOSED:
535 case SSH_CHANNEL_AUTH_SOCKET:
536 case SSH_CHANNEL_DYNAMIC:
537 case SSH_CHANNEL_CONNECTING:
538 case SSH_CHANNEL_ZOMBIE:
540 case SSH_CHANNEL_LARVAL:
542 fatal("cannot happen: SSH_CHANNEL_LARVAL");
544 case SSH_CHANNEL_OPENING:
545 case SSH_CHANNEL_OPEN:
546 case SSH_CHANNEL_X11_OPEN:
547 case SSH_CHANNEL_MUX_CLIENT:
549 case SSH_CHANNEL_INPUT_DRAINING:
550 case SSH_CHANNEL_OUTPUT_DRAINING:
552 fatal("cannot happen: OUT_DRAIN");
555 fatal("channel_still_open: bad channel type %d", c->type);
562 /* Returns the id of an open channel suitable for keepaliving */
564 channel_find_open(void)
569 for (i = 0; i < channels_alloc; i++) {
571 if (c == NULL || c->remote_id < 0)
574 case SSH_CHANNEL_CLOSED:
575 case SSH_CHANNEL_DYNAMIC:
576 case SSH_CHANNEL_X11_LISTENER:
577 case SSH_CHANNEL_PORT_LISTENER:
578 case SSH_CHANNEL_RPORT_LISTENER:
579 case SSH_CHANNEL_MUX_LISTENER:
580 case SSH_CHANNEL_MUX_CLIENT:
581 case SSH_CHANNEL_OPENING:
582 case SSH_CHANNEL_CONNECTING:
583 case SSH_CHANNEL_ZOMBIE:
585 case SSH_CHANNEL_LARVAL:
586 case SSH_CHANNEL_AUTH_SOCKET:
587 case SSH_CHANNEL_OPEN:
588 case SSH_CHANNEL_X11_OPEN:
590 case SSH_CHANNEL_INPUT_DRAINING:
591 case SSH_CHANNEL_OUTPUT_DRAINING:
593 fatal("cannot happen: OUT_DRAIN");
596 fatal("channel_find_open: bad channel type %d", c->type);
605 * Returns a message describing the currently open forwarded connections,
606 * suitable for sending to the client. The message contains crlf pairs for
610 channel_open_message(void)
617 buffer_init(&buffer);
618 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
619 buffer_append(&buffer, buf, strlen(buf));
620 for (i = 0; i < channels_alloc; i++) {
625 case SSH_CHANNEL_X11_LISTENER:
626 case SSH_CHANNEL_PORT_LISTENER:
627 case SSH_CHANNEL_RPORT_LISTENER:
628 case SSH_CHANNEL_CLOSED:
629 case SSH_CHANNEL_AUTH_SOCKET:
630 case SSH_CHANNEL_ZOMBIE:
631 case SSH_CHANNEL_MUX_CLIENT:
632 case SSH_CHANNEL_MUX_LISTENER:
634 case SSH_CHANNEL_LARVAL:
635 case SSH_CHANNEL_OPENING:
636 case SSH_CHANNEL_CONNECTING:
637 case SSH_CHANNEL_DYNAMIC:
638 case SSH_CHANNEL_OPEN:
639 case SSH_CHANNEL_X11_OPEN:
640 case SSH_CHANNEL_INPUT_DRAINING:
641 case SSH_CHANNEL_OUTPUT_DRAINING:
642 snprintf(buf, sizeof buf,
643 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
644 c->self, c->remote_name,
645 c->type, c->remote_id,
646 c->istate, buffer_len(&c->input),
647 c->ostate, buffer_len(&c->output),
648 c->rfd, c->wfd, c->ctl_chan);
649 buffer_append(&buffer, buf, strlen(buf));
652 fatal("channel_open_message: bad channel type %d", c->type);
656 buffer_append(&buffer, "\0", 1);
657 cp = xstrdup(buffer_ptr(&buffer));
658 buffer_free(&buffer);
663 channel_send_open(int id)
665 Channel *c = channel_lookup(id);
668 logit("channel_send_open: %d: bad id", id);
671 debug2("channel %d: send open", id);
672 packet_start(SSH2_MSG_CHANNEL_OPEN);
673 packet_put_cstring(c->ctype);
674 packet_put_int(c->self);
675 packet_put_int(c->local_window);
676 packet_put_int(c->local_maxpacket);
681 channel_request_start(int id, char *service, int wantconfirm)
683 Channel *c = channel_lookup(id);
686 logit("channel_request_start: %d: unknown channel id", id);
689 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
690 packet_start(SSH2_MSG_CHANNEL_REQUEST);
691 packet_put_int(c->remote_id);
692 packet_put_cstring(service);
693 packet_put_char(wantconfirm);
697 channel_register_status_confirm(int id, channel_confirm_cb *cb,
698 channel_confirm_abandon_cb *abandon_cb, void *ctx)
700 struct channel_confirm *cc;
703 if ((c = channel_lookup(id)) == NULL)
704 fatal("channel_register_expect: %d: bad id", id);
706 cc = xmalloc(sizeof(*cc));
708 cc->abandon_cb = abandon_cb;
710 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
714 channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
716 Channel *c = channel_lookup(id);
719 logit("channel_register_open_confirm: %d: bad id", id);
722 c->open_confirm = fn;
723 c->open_confirm_ctx = ctx;
727 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
729 Channel *c = channel_by_id(id);
732 logit("channel_register_cleanup: %d: bad id", id);
736 c->detach_close = do_close;
740 channel_cancel_cleanup(int id)
742 Channel *c = channel_by_id(id);
745 logit("channel_cancel_cleanup: %d: bad id", id);
748 c->detach_user = NULL;
753 channel_register_filter(int id, channel_infilter_fn *ifn,
754 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
756 Channel *c = channel_lookup(id);
759 logit("channel_register_filter: %d: bad id", id);
762 c->input_filter = ifn;
763 c->output_filter = ofn;
765 c->filter_cleanup = cfn;
769 channel_set_fds(int id, int rfd, int wfd, int efd,
770 int extusage, int nonblock, int is_tty, u_int window_max)
772 Channel *c = channel_lookup(id);
774 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
775 fatal("channel_activate for non-larval channel %d.", id);
776 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
777 c->type = SSH_CHANNEL_OPEN;
778 c->local_window = c->local_window_max = window_max;
779 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
780 packet_put_int(c->remote_id);
781 packet_put_int(c->local_window);
786 * 'channel_pre*' are called just before select() to add any bits relevant to
787 * channels in the select bitmasks.
790 * 'channel_post*': perform any appropriate operations for channels which
791 * have events pending.
793 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
794 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
795 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
799 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
801 FD_SET(c->sock, readset);
806 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
808 debug3("channel %d: waiting for connection", c->self);
809 FD_SET(c->sock, writeset);
813 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
815 if (buffer_len(&c->input) < packet_get_maxsize())
816 FD_SET(c->sock, readset);
817 if (buffer_len(&c->output) > 0)
818 FD_SET(c->sock, writeset);
822 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
824 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
826 if (c->istate == CHAN_INPUT_OPEN &&
828 buffer_len(&c->input) < limit &&
829 buffer_check_alloc(&c->input, CHAN_RBUF))
830 FD_SET(c->rfd, readset);
831 if (c->ostate == CHAN_OUTPUT_OPEN ||
832 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
833 if (buffer_len(&c->output) > 0) {
834 FD_SET(c->wfd, writeset);
835 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
836 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
837 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
838 c->self, c->efd, buffer_len(&c->extended));
843 /** XXX check close conditions, too */
844 if (compat20 && c->efd != -1 &&
845 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
846 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
847 buffer_len(&c->extended) > 0)
848 FD_SET(c->efd, writeset);
849 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
850 (c->extended_usage == CHAN_EXTENDED_READ ||
851 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
852 buffer_len(&c->extended) < c->remote_window)
853 FD_SET(c->efd, readset);
855 /* XXX: What about efd? races? */
860 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
862 if (buffer_len(&c->input) == 0) {
863 packet_start(SSH_MSG_CHANNEL_CLOSE);
864 packet_put_int(c->remote_id);
866 c->type = SSH_CHANNEL_CLOSED;
867 debug2("channel %d: closing after input drain.", c->self);
873 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
875 if (buffer_len(&c->output) == 0)
878 FD_SET(c->sock, writeset);
882 * This is a special state for X11 authentication spoofing. An opened X11
883 * connection (when authentication spoofing is being done) remains in this
884 * state until the first packet has been completely read. The authentication
885 * data in that packet is then substituted by the real data if it matches the
886 * fake data, and the channel is put into normal mode.
887 * XXX All this happens at the client side.
888 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
891 x11_open_helper(Buffer *b)
894 u_int proto_len, data_len;
896 /* Check if the fixed size part of the packet is in buffer. */
897 if (buffer_len(b) < 12)
900 /* Parse the lengths of variable-length fields. */
902 if (ucp[0] == 0x42) { /* Byte order MSB first. */
903 proto_len = 256 * ucp[6] + ucp[7];
904 data_len = 256 * ucp[8] + ucp[9];
905 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
906 proto_len = ucp[6] + 256 * ucp[7];
907 data_len = ucp[8] + 256 * ucp[9];
909 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
914 /* Check if the whole packet is in buffer. */
916 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
919 /* Check if authentication protocol matches. */
920 if (proto_len != strlen(x11_saved_proto) ||
921 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
922 debug2("X11 connection uses different authentication protocol.");
925 /* Check if authentication data matches our fake data. */
926 if (data_len != x11_fake_data_len ||
927 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
928 x11_fake_data, x11_fake_data_len) != 0) {
929 debug2("X11 auth data does not match fake data.");
932 /* Check fake data length */
933 if (x11_fake_data_len != x11_saved_data_len) {
934 error("X11 fake_data_len %d != saved_data_len %d",
935 x11_fake_data_len, x11_saved_data_len);
939 * Received authentication protocol and data match
940 * our fake data. Substitute the fake data with real
943 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
944 x11_saved_data, x11_saved_data_len);
949 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
951 int ret = x11_open_helper(&c->output);
954 /* Start normal processing for the channel. */
955 c->type = SSH_CHANNEL_OPEN;
956 channel_pre_open_13(c, readset, writeset);
957 } else if (ret == -1) {
959 * We have received an X11 connection that has bad
960 * authentication information.
962 logit("X11 connection rejected because of wrong authentication.");
963 buffer_clear(&c->input);
964 buffer_clear(&c->output);
965 channel_close_fd(&c->sock);
967 c->type = SSH_CHANNEL_CLOSED;
968 packet_start(SSH_MSG_CHANNEL_CLOSE);
969 packet_put_int(c->remote_id);
975 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
977 int ret = x11_open_helper(&c->output);
979 /* c->force_drain = 1; */
982 c->type = SSH_CHANNEL_OPEN;
983 channel_pre_open(c, readset, writeset);
984 } else if (ret == -1) {
985 logit("X11 connection rejected because of wrong authentication.");
986 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
988 buffer_clear(&c->input);
990 buffer_clear(&c->output);
991 /* for proto v1, the peer will send an IEOF */
993 chan_write_failed(c);
995 c->type = SSH_CHANNEL_OPEN;
996 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1001 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1003 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1004 buffer_check_alloc(&c->input, CHAN_RBUF))
1005 FD_SET(c->rfd, readset);
1006 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1007 /* clear buffer immediately (discard any partial packet) */
1008 buffer_clear(&c->input);
1010 /* Start output drain. XXX just kill chan? */
1011 chan_rcvd_oclose(c);
1013 if (c->ostate == CHAN_OUTPUT_OPEN ||
1014 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1015 if (buffer_len(&c->output) > 0)
1016 FD_SET(c->wfd, writeset);
1017 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1022 /* try to decode a socks4 header */
1025 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1028 u_int len, have, i, found, need;
1033 u_int16_t dest_port;
1034 struct in_addr dest_addr;
1037 debug2("channel %d: decode socks4", c->self);
1039 have = buffer_len(&c->input);
1040 len = sizeof(s4_req);
1043 p = buffer_ptr(&c->input);
1046 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1047 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1048 debug2("channel %d: socks4a request", c->self);
1049 /* ... and needs an extra string (the hostname) */
1052 /* Check for terminating NUL on the string(s) */
1053 for (found = 0, i = len; i < have; i++) {
1060 /* the peer is probably sending garbage */
1061 debug("channel %d: decode socks4: too long",
1068 buffer_get(&c->input, (char *)&s4_req.version, 1);
1069 buffer_get(&c->input, (char *)&s4_req.command, 1);
1070 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1071 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1072 have = buffer_len(&c->input);
1073 p = buffer_ptr(&c->input);
1075 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1076 len++; /* trailing '\0' */
1078 fatal("channel %d: decode socks4: len %d > have %d",
1079 c->self, len, have);
1080 strlcpy(username, p, sizeof(username));
1081 buffer_consume(&c->input, len);
1083 if (c->path != NULL) {
1087 if (need == 1) { /* SOCKS4: one string */
1088 host = inet_ntoa(s4_req.dest_addr);
1089 c->path = xstrdup(host);
1090 } else { /* SOCKS4A: two strings */
1091 have = buffer_len(&c->input);
1092 p = buffer_ptr(&c->input);
1094 debug2("channel %d: decode socks4a: host %s/%d",
1096 len++; /* trailing '\0' */
1098 fatal("channel %d: decode socks4a: len %d > have %d",
1099 c->self, len, have);
1100 if (len > NI_MAXHOST) {
1101 error("channel %d: hostname \"%.100s\" too long",
1105 c->path = xstrdup(p);
1106 buffer_consume(&c->input, len);
1108 c->host_port = ntohs(s4_req.dest_port);
1110 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1111 c->self, c->path, c->host_port, s4_req.command);
1113 if (s4_req.command != 1) {
1114 debug("channel %d: cannot handle: %s cn %d",
1115 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1118 s4_rsp.version = 0; /* vn: 0 for reply */
1119 s4_rsp.command = 90; /* cd: req granted */
1120 s4_rsp.dest_port = 0; /* ignored */
1121 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1122 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1126 /* try to decode a socks5 header */
1127 #define SSH_SOCKS5_AUTHDONE 0x1000
1128 #define SSH_SOCKS5_NOAUTH 0x00
1129 #define SSH_SOCKS5_IPV4 0x01
1130 #define SSH_SOCKS5_DOMAIN 0x03
1131 #define SSH_SOCKS5_IPV6 0x04
1132 #define SSH_SOCKS5_CONNECT 0x01
1133 #define SSH_SOCKS5_SUCCESS 0x00
1137 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1145 u_int16_t dest_port;
1146 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1147 u_int have, need, i, found, nmethods, addrlen, af;
1149 debug2("channel %d: decode socks5", c->self);
1150 p = buffer_ptr(&c->input);
1153 have = buffer_len(&c->input);
1154 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1155 /* format: ver | nmethods | methods */
1159 if (have < nmethods + 2)
1161 /* look for method: "NO AUTHENTICATION REQUIRED" */
1162 for (found = 0, i = 2; i < nmethods + 2; i++) {
1163 if (p[i] == SSH_SOCKS5_NOAUTH) {
1169 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1173 buffer_consume(&c->input, nmethods + 2);
1174 buffer_put_char(&c->output, 0x05); /* version */
1175 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1176 FD_SET(c->sock, writeset);
1177 c->flags |= SSH_SOCKS5_AUTHDONE;
1178 debug2("channel %d: socks5 auth done", c->self);
1179 return 0; /* need more */
1181 debug2("channel %d: socks5 post auth", c->self);
1182 if (have < sizeof(s5_req)+1)
1183 return 0; /* need more */
1184 memcpy(&s5_req, p, sizeof(s5_req));
1185 if (s5_req.version != 0x05 ||
1186 s5_req.command != SSH_SOCKS5_CONNECT ||
1187 s5_req.reserved != 0x00) {
1188 debug2("channel %d: only socks5 connect supported", c->self);
1191 switch (s5_req.atyp){
1192 case SSH_SOCKS5_IPV4:
1196 case SSH_SOCKS5_DOMAIN:
1197 addrlen = p[sizeof(s5_req)];
1200 case SSH_SOCKS5_IPV6:
1205 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1208 need = sizeof(s5_req) + addrlen + 2;
1209 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1213 buffer_consume(&c->input, sizeof(s5_req));
1214 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1215 buffer_consume(&c->input, 1); /* host string length */
1216 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1217 buffer_get(&c->input, (char *)&dest_port, 2);
1218 dest_addr[addrlen] = '\0';
1219 if (c->path != NULL) {
1223 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1224 if (addrlen >= NI_MAXHOST) {
1225 error("channel %d: dynamic request: socks5 hostname "
1226 "\"%.100s\" too long", c->self, dest_addr);
1229 c->path = xstrdup(dest_addr);
1231 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1233 c->path = xstrdup(ntop);
1235 c->host_port = ntohs(dest_port);
1237 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1238 c->self, c->path, c->host_port, s5_req.command);
1240 s5_rsp.version = 0x05;
1241 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1242 s5_rsp.reserved = 0; /* ignored */
1243 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1244 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1245 dest_port = 0; /* ignored */
1247 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1248 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1249 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1254 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1259 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1262 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1263 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1264 0, "stdio-forward", /*nonblock*/0);
1266 c->path = xstrdup(host_to_connect);
1267 c->host_port = port_to_connect;
1268 c->listening_port = 0;
1271 channel_register_fds(c, in, out, -1, 0, 1, 0);
1272 port_open_helper(c, "direct-tcpip");
1277 /* dynamic port forwarding */
1279 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1285 have = buffer_len(&c->input);
1286 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1287 /* buffer_dump(&c->input); */
1288 /* check if the fixed size part of the packet is in buffer. */
1291 FD_SET(c->sock, readset);
1294 /* try to guess the protocol */
1295 p = buffer_ptr(&c->input);
1298 ret = channel_decode_socks4(c, readset, writeset);
1301 ret = channel_decode_socks5(c, readset, writeset);
1309 } else if (ret == 0) {
1310 debug2("channel %d: pre_dynamic: need more", c->self);
1312 FD_SET(c->sock, readset);
1314 /* switch to the next state */
1315 c->type = SSH_CHANNEL_OPENING;
1316 port_open_helper(c, "direct-tcpip");
1320 /* This is our fake X11 server socket. */
1323 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1326 struct sockaddr_storage addr;
1329 char buf[16384], *remote_ipaddr;
1332 if (FD_ISSET(c->sock, readset)) {
1333 debug("X11 connection requested.");
1334 addrlen = sizeof(addr);
1335 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1336 if (c->single_connection) {
1337 debug2("single_connection: closing X11 listener.");
1338 channel_close_fd(&c->sock);
1342 error("accept: %.100s", strerror(errno));
1343 if (errno == EMFILE || errno == ENFILE)
1344 c->notbefore = time(NULL) + 1;
1347 set_nodelay(newsock);
1348 remote_ipaddr = get_peer_ipaddr(newsock);
1349 remote_port = get_peer_port(newsock);
1350 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1351 remote_ipaddr, remote_port);
1353 nc = channel_new("accepted x11 socket",
1354 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1355 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1357 packet_start(SSH2_MSG_CHANNEL_OPEN);
1358 packet_put_cstring("x11");
1359 packet_put_int(nc->self);
1360 packet_put_int(nc->local_window_max);
1361 packet_put_int(nc->local_maxpacket);
1362 /* originator ipaddr and port */
1363 packet_put_cstring(remote_ipaddr);
1364 if (datafellows & SSH_BUG_X11FWD) {
1365 debug2("ssh2 x11 bug compat mode");
1367 packet_put_int(remote_port);
1371 packet_start(SSH_SMSG_X11_OPEN);
1372 packet_put_int(nc->self);
1373 if (packet_get_protocol_flags() &
1374 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1375 packet_put_cstring(buf);
1378 xfree(remote_ipaddr);
1383 port_open_helper(Channel *c, char *rtype)
1387 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1388 int remote_port = get_peer_port(c->sock);
1390 if (remote_port == -1) {
1391 /* Fake addr/port to appease peers that validate it (Tectia) */
1392 xfree(remote_ipaddr);
1393 remote_ipaddr = xstrdup("127.0.0.1");
1394 remote_port = 65535;
1397 direct = (strcmp(rtype, "direct-tcpip") == 0);
1399 snprintf(buf, sizeof buf,
1400 "%s: listening port %d for %.100s port %d, "
1401 "connect from %.200s port %d",
1402 rtype, c->listening_port, c->path, c->host_port,
1403 remote_ipaddr, remote_port);
1405 xfree(c->remote_name);
1406 c->remote_name = xstrdup(buf);
1409 packet_start(SSH2_MSG_CHANNEL_OPEN);
1410 packet_put_cstring(rtype);
1411 packet_put_int(c->self);
1412 packet_put_int(c->local_window_max);
1413 packet_put_int(c->local_maxpacket);
1415 /* target host, port */
1416 packet_put_cstring(c->path);
1417 packet_put_int(c->host_port);
1419 /* listen address, port */
1420 packet_put_cstring(c->path);
1421 packet_put_int(c->listening_port);
1423 /* originator host and port */
1424 packet_put_cstring(remote_ipaddr);
1425 packet_put_int((u_int)remote_port);
1428 packet_start(SSH_MSG_PORT_OPEN);
1429 packet_put_int(c->self);
1430 packet_put_cstring(c->path);
1431 packet_put_int(c->host_port);
1432 if (packet_get_protocol_flags() &
1433 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1434 packet_put_cstring(c->remote_name);
1437 xfree(remote_ipaddr);
1441 channel_set_reuseaddr(int fd)
1446 * Set socket options.
1447 * Allow local port reuse in TIME_WAIT.
1449 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1450 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1454 * This socket is listening for connections to a forwarded TCP/IP port.
1458 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1461 struct sockaddr_storage addr;
1462 int newsock, nextstate;
1466 if (FD_ISSET(c->sock, readset)) {
1467 debug("Connection to port %d forwarding "
1468 "to %.100s port %d requested.",
1469 c->listening_port, c->path, c->host_port);
1471 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1472 nextstate = SSH_CHANNEL_OPENING;
1473 rtype = "forwarded-tcpip";
1475 if (c->host_port == 0) {
1476 nextstate = SSH_CHANNEL_DYNAMIC;
1477 rtype = "dynamic-tcpip";
1479 nextstate = SSH_CHANNEL_OPENING;
1480 rtype = "direct-tcpip";
1484 addrlen = sizeof(addr);
1485 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1487 error("accept: %.100s", strerror(errno));
1488 if (errno == EMFILE || errno == ENFILE)
1489 c->notbefore = time(NULL) + 1;
1492 set_nodelay(newsock);
1493 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1494 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1495 nc->listening_port = c->listening_port;
1496 nc->host_port = c->host_port;
1497 if (c->path != NULL)
1498 nc->path = xstrdup(c->path);
1500 if (nextstate != SSH_CHANNEL_DYNAMIC)
1501 port_open_helper(nc, rtype);
1506 * This is the authentication agent socket listening for connections from
1511 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1515 struct sockaddr_storage addr;
1518 if (FD_ISSET(c->sock, readset)) {
1519 addrlen = sizeof(addr);
1520 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1522 error("accept from auth socket: %.100s",
1524 if (errno == EMFILE || errno == ENFILE)
1525 c->notbefore = time(NULL) + 1;
1528 nc = channel_new("accepted auth socket",
1529 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1530 c->local_window_max, c->local_maxpacket,
1531 0, "accepted auth socket", 1);
1533 packet_start(SSH2_MSG_CHANNEL_OPEN);
1534 packet_put_cstring("auth-agent@openssh.com");
1535 packet_put_int(nc->self);
1536 packet_put_int(c->local_window_max);
1537 packet_put_int(c->local_maxpacket);
1539 packet_start(SSH_SMSG_AGENT_OPEN);
1540 packet_put_int(nc->self);
1548 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1551 socklen_t sz = sizeof(err);
1553 if (FD_ISSET(c->sock, writeset)) {
1554 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1556 error("getsockopt SO_ERROR failed");
1559 debug("channel %d: connected to %s port %d",
1560 c->self, c->connect_ctx.host, c->connect_ctx.port);
1561 channel_connect_ctx_free(&c->connect_ctx);
1562 c->type = SSH_CHANNEL_OPEN;
1564 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1565 packet_put_int(c->remote_id);
1566 packet_put_int(c->self);
1567 packet_put_int(c->local_window);
1568 packet_put_int(c->local_maxpacket);
1570 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1571 packet_put_int(c->remote_id);
1572 packet_put_int(c->self);
1575 debug("channel %d: connection failed: %s",
1576 c->self, strerror(err));
1577 /* Try next address, if any */
1578 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1580 c->sock = c->rfd = c->wfd = sock;
1581 channel_max_fd = channel_find_maxfd();
1584 /* Exhausted all addresses */
1585 error("connect_to %.100s port %d: failed.",
1586 c->connect_ctx.host, c->connect_ctx.port);
1587 channel_connect_ctx_free(&c->connect_ctx);
1589 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1590 packet_put_int(c->remote_id);
1591 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1592 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1593 packet_put_cstring(strerror(err));
1594 packet_put_cstring("");
1597 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1598 packet_put_int(c->remote_id);
1608 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1610 char buf[CHAN_RBUF];
1613 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1614 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1616 len = read(c->rfd, buf, sizeof(buf));
1617 if (len < 0 && (errno == EINTR ||
1618 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1620 #ifndef PTY_ZEROREAD
1623 if ((!c->isatty && len <= 0) ||
1624 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1626 debug2("channel %d: read<=0 rfd %d len %d",
1627 c->self, c->rfd, len);
1628 if (c->type != SSH_CHANNEL_OPEN) {
1629 debug2("channel %d: not open", c->self);
1632 } else if (compat13) {
1633 buffer_clear(&c->output);
1634 c->type = SSH_CHANNEL_INPUT_DRAINING;
1635 debug2("channel %d: input draining.", c->self);
1637 chan_read_failed(c);
1641 if (c->input_filter != NULL) {
1642 if (c->input_filter(c, buf, len) == -1) {
1643 debug2("channel %d: filter stops", c->self);
1644 chan_read_failed(c);
1646 } else if (c->datagram) {
1647 buffer_put_string(&c->input, buf, len);
1649 buffer_append(&c->input, buf, len);
1657 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1660 u_char *data = NULL, *buf;
1661 u_int dlen, olen = 0;
1664 /* Send buffered output data to the socket. */
1666 FD_ISSET(c->wfd, writeset) &&
1667 buffer_len(&c->output) > 0) {
1668 olen = buffer_len(&c->output);
1669 if (c->output_filter != NULL) {
1670 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1671 debug2("channel %d: filter stops", c->self);
1672 if (c->type != SSH_CHANNEL_OPEN)
1675 chan_write_failed(c);
1678 } else if (c->datagram) {
1679 buf = data = buffer_get_string(&c->output, &dlen);
1681 buf = data = buffer_ptr(&c->output);
1682 dlen = buffer_len(&c->output);
1686 /* ignore truncated writes, datagrams might get lost */
1687 len = write(c->wfd, buf, dlen);
1689 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1690 errno == EWOULDBLOCK))
1693 if (c->type != SSH_CHANNEL_OPEN)
1696 chan_write_failed(c);
1702 /* XXX: Later AIX versions can't push as much data to tty */
1703 if (compat20 && c->wfd_isatty)
1704 dlen = MIN(dlen, 8*1024);
1707 len = write(c->wfd, buf, dlen);
1709 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1712 if (c->type != SSH_CHANNEL_OPEN) {
1713 debug2("channel %d: not open", c->self);
1716 } else if (compat13) {
1717 buffer_clear(&c->output);
1718 debug2("channel %d: input draining.", c->self);
1719 c->type = SSH_CHANNEL_INPUT_DRAINING;
1721 chan_write_failed(c);
1725 #ifndef BROKEN_TCGETATTR_ICANON
1726 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1727 if (tcgetattr(c->wfd, &tio) == 0 &&
1728 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1730 * Simulate echo to reduce the impact of
1731 * traffic analysis. We need to match the
1732 * size of a SSH2_MSG_CHANNEL_DATA message
1733 * (4 byte channel id + buf)
1735 packet_send_ignore(4 + len);
1740 buffer_consume(&c->output, len);
1743 if (compat20 && olen > 0)
1744 c->local_consumed += olen - buffer_len(&c->output);
1749 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1751 char buf[CHAN_RBUF];
1754 /** XXX handle drain efd, too */
1756 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1757 FD_ISSET(c->efd, writeset) &&
1758 buffer_len(&c->extended) > 0) {
1759 len = write(c->efd, buffer_ptr(&c->extended),
1760 buffer_len(&c->extended));
1761 debug2("channel %d: written %d to efd %d",
1762 c->self, len, c->efd);
1763 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1764 errno == EWOULDBLOCK))
1767 debug2("channel %d: closing write-efd %d",
1769 channel_close_fd(&c->efd);
1771 buffer_consume(&c->extended, len);
1772 c->local_consumed += len;
1774 } else if (c->efd != -1 &&
1775 (c->extended_usage == CHAN_EXTENDED_READ ||
1776 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1777 (c->detach_close || FD_ISSET(c->efd, readset))) {
1778 len = read(c->efd, buf, sizeof(buf));
1779 debug2("channel %d: read %d from efd %d",
1780 c->self, len, c->efd);
1781 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1782 errno == EWOULDBLOCK) && !c->detach_close)))
1785 debug2("channel %d: closing read-efd %d",
1787 channel_close_fd(&c->efd);
1789 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1790 debug3("channel %d: discard efd",
1793 buffer_append(&c->extended, buf, len);
1801 channel_check_window(Channel *c)
1803 if (c->type == SSH_CHANNEL_OPEN &&
1804 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1805 ((c->local_window_max - c->local_window >
1806 c->local_maxpacket*3) ||
1807 c->local_window < c->local_window_max/2) &&
1808 c->local_consumed > 0) {
1809 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1810 packet_put_int(c->remote_id);
1811 packet_put_int(c->local_consumed);
1813 debug2("channel %d: window %d sent adjust %d",
1814 c->self, c->local_window,
1816 c->local_window += c->local_consumed;
1817 c->local_consumed = 0;
1823 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1825 channel_handle_rfd(c, readset, writeset);
1826 channel_handle_wfd(c, readset, writeset);
1829 channel_handle_efd(c, readset, writeset);
1830 channel_check_window(c);
1834 read_mux(Channel *c, u_int need)
1836 char buf[CHAN_RBUF];
1840 if (buffer_len(&c->input) < need) {
1841 rlen = need - buffer_len(&c->input);
1842 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1844 if (errno != EINTR && errno != EAGAIN) {
1845 debug2("channel %d: ctl read<=0 rfd %d len %d",
1846 c->self, c->rfd, len);
1847 chan_read_failed(c);
1851 buffer_append(&c->input, buf, len);
1853 return buffer_len(&c->input);
1857 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1863 fatal("%s: entered with !compat20", __func__);
1865 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1866 (c->istate == CHAN_INPUT_OPEN ||
1867 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1869 * Don't not read past the precise end of packets to
1870 * avoid disrupting fd passing.
1872 if (read_mux(c, 4) < 4) /* read header */
1874 need = get_u32(buffer_ptr(&c->input));
1875 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1876 if (need > CHANNEL_MUX_MAX_PACKET) {
1877 debug2("channel %d: packet too big %u > %u",
1878 c->self, CHANNEL_MUX_MAX_PACKET, need);
1879 chan_rcvd_oclose(c);
1882 if (read_mux(c, need + 4) < need + 4) /* read body */
1884 if (c->mux_rcb(c) != 0) {
1885 debug("channel %d: mux_rcb failed", c->self);
1891 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1892 buffer_len(&c->output) > 0) {
1893 len = write(c->wfd, buffer_ptr(&c->output),
1894 buffer_len(&c->output));
1895 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1901 buffer_consume(&c->output, len);
1906 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1909 struct sockaddr_storage addr;
1915 if (!FD_ISSET(c->sock, readset))
1918 debug("multiplexing control connection");
1921 * Accept connection on control socket
1923 memset(&addr, 0, sizeof(addr));
1924 addrlen = sizeof(addr);
1925 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1927 error("%s accept: %s", __func__, strerror(errno));
1928 if (errno == EMFILE || errno == ENFILE)
1929 c->notbefore = time(NULL) + 1;
1933 if (getpeereid(newsock, &euid, &egid) < 0) {
1934 error("%s getpeereid failed: %s", __func__,
1939 if ((euid != 0) && (getuid() != euid)) {
1940 error("multiplex uid mismatch: peer euid %u != uid %u",
1941 (u_int)euid, (u_int)getuid());
1945 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1946 newsock, newsock, -1, c->local_window_max,
1947 c->local_maxpacket, 0, "mux-control", 1);
1948 nc->mux_rcb = c->mux_rcb;
1949 debug3("%s: new mux channel %d fd %d", __func__,
1950 nc->self, nc->sock);
1951 /* establish state */
1953 /* mux state transitions must not elicit protocol messages */
1954 nc->flags |= CHAN_LOCAL;
1959 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1963 /* Send buffered output data to the socket. */
1964 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1965 len = write(c->sock, buffer_ptr(&c->output),
1966 buffer_len(&c->output));
1968 buffer_clear(&c->output);
1970 buffer_consume(&c->output, len);
1975 channel_handler_init_20(void)
1977 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1978 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1979 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1980 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1981 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1982 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1983 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1984 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1985 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1986 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1988 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1989 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1990 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1991 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1992 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1993 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1994 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1995 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1996 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2000 channel_handler_init_13(void)
2002 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2003 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2004 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2005 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2006 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2007 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2008 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2009 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2010 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2012 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2013 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2014 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2015 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2016 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2017 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2018 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2022 channel_handler_init_15(void)
2024 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2025 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2026 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2027 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2028 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2029 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2030 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2032 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2033 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2034 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2035 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2036 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2037 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2041 channel_handler_init(void)
2045 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2046 channel_pre[i] = NULL;
2047 channel_post[i] = NULL;
2050 channel_handler_init_20();
2052 channel_handler_init_13();
2054 channel_handler_init_15();
2057 /* gc dead channels */
2059 channel_garbage_collect(Channel *c)
2063 if (c->detach_user != NULL) {
2064 if (!chan_is_dead(c, c->detach_close))
2066 debug2("channel %d: gc: notify user", c->self);
2067 c->detach_user(c->self, NULL);
2068 /* if we still have a callback */
2069 if (c->detach_user != NULL)
2071 debug2("channel %d: gc: user detached", c->self);
2073 if (!chan_is_dead(c, 1))
2075 debug2("channel %d: garbage collecting", c->self);
2080 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2081 time_t *unpause_secs)
2083 static int did_init = 0;
2089 channel_handler_init();
2093 if (unpause_secs != NULL)
2095 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2100 if (ftab == channel_pre)
2105 if (ftab[c->type] != NULL) {
2107 * Run handlers that are not paused.
2109 if (c->notbefore <= now)
2110 (*ftab[c->type])(c, readset, writeset);
2111 else if (unpause_secs != NULL) {
2113 * Collect the time that the earliest
2114 * channel comes off pause.
2116 debug3("%s: chan %d: skip for %d more seconds",
2118 (int)(c->notbefore - now));
2119 if (*unpause_secs == 0 ||
2120 (c->notbefore - now) < *unpause_secs)
2121 *unpause_secs = c->notbefore - now;
2124 channel_garbage_collect(c);
2126 if (unpause_secs != NULL && *unpause_secs != 0)
2127 debug3("%s: first channel unpauses in %d seconds",
2128 __func__, (int)*unpause_secs);
2132 * Allocate/update select bitmasks and add any bits relevant to channels in
2136 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2137 u_int *nallocp, time_t *minwait_secs, int rekeying)
2139 u_int n, sz, nfdset;
2141 n = MAX(*maxfdp, channel_max_fd);
2143 nfdset = howmany(n+1, NFDBITS);
2144 /* Explicitly test here, because xrealloc isn't always called */
2145 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2146 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2147 sz = nfdset * sizeof(fd_mask);
2149 /* perhaps check sz < nalloc/2 and shrink? */
2150 if (*readsetp == NULL || sz > *nallocp) {
2151 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2152 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2156 memset(*readsetp, 0, sz);
2157 memset(*writesetp, 0, sz);
2160 channel_handler(channel_pre, *readsetp, *writesetp,
2165 * After select, perform any appropriate operations for channels which have
2169 channel_after_select(fd_set *readset, fd_set *writeset)
2171 channel_handler(channel_post, readset, writeset, NULL);
2175 /* If there is data to send to the connection, enqueue some of it now. */
2177 channel_output_poll(void)
2182 for (i = 0; i < channels_alloc; i++) {
2188 * We are only interested in channels that can have buffered
2192 if (c->type != SSH_CHANNEL_OPEN &&
2193 c->type != SSH_CHANNEL_INPUT_DRAINING)
2196 if (c->type != SSH_CHANNEL_OPEN)
2200 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2201 /* XXX is this true? */
2202 debug3("channel %d: will not send data after close", c->self);
2206 /* Get the amount of buffered data for this channel. */
2207 if ((c->istate == CHAN_INPUT_OPEN ||
2208 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2209 (len = buffer_len(&c->input)) > 0) {
2215 data = buffer_get_string(&c->input,
2217 if (dlen > c->remote_window ||
2218 dlen > c->remote_maxpacket) {
2219 debug("channel %d: datagram "
2220 "too big for channel",
2225 packet_start(SSH2_MSG_CHANNEL_DATA);
2226 packet_put_int(c->remote_id);
2227 packet_put_string(data, dlen);
2229 c->remote_window -= dlen + 4;
2235 * Send some data for the other side over the secure
2239 if (len > c->remote_window)
2240 len = c->remote_window;
2241 if (len > c->remote_maxpacket)
2242 len = c->remote_maxpacket;
2244 if (packet_is_interactive()) {
2248 /* Keep the packets at reasonable size. */
2249 if (len > packet_get_maxsize()/2)
2250 len = packet_get_maxsize()/2;
2254 packet_start(compat20 ?
2255 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2256 packet_put_int(c->remote_id);
2257 packet_put_string(buffer_ptr(&c->input), len);
2259 buffer_consume(&c->input, len);
2260 c->remote_window -= len;
2262 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2264 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2266 * input-buffer is empty and read-socket shutdown:
2267 * tell peer, that we will not send more data: send IEOF.
2268 * hack for extended data: delay EOF if EFD still in use.
2270 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2271 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2272 c->self, c->efd, buffer_len(&c->extended));
2276 /* Send extended data, i.e. stderr */
2278 !(c->flags & CHAN_EOF_SENT) &&
2279 c->remote_window > 0 &&
2280 (len = buffer_len(&c->extended)) > 0 &&
2281 c->extended_usage == CHAN_EXTENDED_READ) {
2282 debug2("channel %d: rwin %u elen %u euse %d",
2283 c->self, c->remote_window, buffer_len(&c->extended),
2285 if (len > c->remote_window)
2286 len = c->remote_window;
2287 if (len > c->remote_maxpacket)
2288 len = c->remote_maxpacket;
2289 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2290 packet_put_int(c->remote_id);
2291 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2292 packet_put_string(buffer_ptr(&c->extended), len);
2294 buffer_consume(&c->extended, len);
2295 c->remote_window -= len;
2296 debug2("channel %d: sent ext data %d", c->self, len);
2302 /* -- protocol input */
2306 channel_input_data(int type, u_int32_t seq, void *ctxt)
2310 u_int data_len, win_len;
2313 /* Get the channel number and verify it. */
2314 id = packet_get_int();
2315 c = channel_lookup(id);
2317 packet_disconnect("Received data for nonexistent channel %d.", id);
2319 /* Ignore any data for non-open channels (might happen on close) */
2320 if (c->type != SSH_CHANNEL_OPEN &&
2321 c->type != SSH_CHANNEL_X11_OPEN)
2325 data = packet_get_string_ptr(&data_len);
2328 win_len += 4; /* string length header */
2331 * Ignore data for protocol > 1.3 if output end is no longer open.
2332 * For protocol 2 the sending side is reducing its window as it sends
2333 * data, so we must 'fake' consumption of the data in order to ensure
2334 * that window updates are sent back. Otherwise the connection might
2337 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2339 c->local_window -= win_len;
2340 c->local_consumed += win_len;
2346 if (win_len > c->local_maxpacket) {
2347 logit("channel %d: rcvd big packet %d, maxpack %d",
2348 c->self, win_len, c->local_maxpacket);
2350 if (win_len > c->local_window) {
2351 logit("channel %d: rcvd too much data %d, win %d",
2352 c->self, win_len, c->local_window);
2355 c->local_window -= win_len;
2358 buffer_put_string(&c->output, data, data_len);
2360 buffer_append(&c->output, data, data_len);
2366 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2370 u_int data_len, tcode;
2373 /* Get the channel number and verify it. */
2374 id = packet_get_int();
2375 c = channel_lookup(id);
2378 packet_disconnect("Received extended_data for bad channel %d.", id);
2379 if (c->type != SSH_CHANNEL_OPEN) {
2380 logit("channel %d: ext data for non open", id);
2383 if (c->flags & CHAN_EOF_RCVD) {
2384 if (datafellows & SSH_BUG_EXTEOF)
2385 debug("channel %d: accepting ext data after eof", id);
2387 packet_disconnect("Received extended_data after EOF "
2388 "on channel %d.", id);
2390 tcode = packet_get_int();
2392 c->extended_usage != CHAN_EXTENDED_WRITE ||
2393 tcode != SSH2_EXTENDED_DATA_STDERR) {
2394 logit("channel %d: bad ext data", c->self);
2397 data = packet_get_string(&data_len);
2399 if (data_len > c->local_window) {
2400 logit("channel %d: rcvd too much extended_data %d, win %d",
2401 c->self, data_len, c->local_window);
2405 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2406 c->local_window -= data_len;
2407 buffer_append(&c->extended, data, data_len);
2413 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2418 id = packet_get_int();
2420 c = channel_lookup(id);
2422 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2425 /* XXX force input close */
2426 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2427 debug("channel %d: FORCE input drain", c->self);
2428 c->istate = CHAN_INPUT_WAIT_DRAIN;
2429 if (buffer_len(&c->input) == 0)
2437 channel_input_close(int type, u_int32_t seq, void *ctxt)
2442 id = packet_get_int();
2444 c = channel_lookup(id);
2446 packet_disconnect("Received close for nonexistent channel %d.", id);
2449 * Send a confirmation that we have closed the channel and no more
2450 * data is coming for it.
2452 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2453 packet_put_int(c->remote_id);
2457 * If the channel is in closed state, we have sent a close request,
2458 * and the other side will eventually respond with a confirmation.
2459 * Thus, we cannot free the channel here, because then there would be
2460 * no-one to receive the confirmation. The channel gets freed when
2461 * the confirmation arrives.
2463 if (c->type != SSH_CHANNEL_CLOSED) {
2465 * Not a closed channel - mark it as draining, which will
2466 * cause it to be freed later.
2468 buffer_clear(&c->input);
2469 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2473 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2476 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2478 int id = packet_get_int();
2479 Channel *c = channel_lookup(id);
2483 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2484 chan_rcvd_oclose(c);
2489 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2491 int id = packet_get_int();
2492 Channel *c = channel_lookup(id);
2496 packet_disconnect("Received close confirmation for "
2497 "out-of-range channel %d.", id);
2498 if (c->type != SSH_CHANNEL_CLOSED)
2499 packet_disconnect("Received close confirmation for "
2500 "non-closed channel %d (type %d).", id, c->type);
2506 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2511 id = packet_get_int();
2512 c = channel_lookup(id);
2514 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2515 packet_disconnect("Received open confirmation for "
2516 "non-opening channel %d.", id);
2517 remote_id = packet_get_int();
2518 /* Record the remote channel number and mark that the channel is now open. */
2519 c->remote_id = remote_id;
2520 c->type = SSH_CHANNEL_OPEN;
2523 c->remote_window = packet_get_int();
2524 c->remote_maxpacket = packet_get_int();
2525 if (c->open_confirm) {
2526 debug2("callback start");
2527 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2528 debug2("callback done");
2530 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2531 c->remote_window, c->remote_maxpacket);
2537 reason2txt(int reason)
2540 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2541 return "administratively prohibited";
2542 case SSH2_OPEN_CONNECT_FAILED:
2543 return "connect failed";
2544 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2545 return "unknown channel type";
2546 case SSH2_OPEN_RESOURCE_SHORTAGE:
2547 return "resource shortage";
2549 return "unknown reason";
2554 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2557 char *msg = NULL, *lang = NULL;
2560 id = packet_get_int();
2561 c = channel_lookup(id);
2563 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2564 packet_disconnect("Received open failure for "
2565 "non-opening channel %d.", id);
2567 reason = packet_get_int();
2568 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2569 msg = packet_get_string(NULL);
2570 lang = packet_get_string(NULL);
2572 logit("channel %d: open failed: %s%s%s", id,
2573 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2578 if (c->open_confirm) {
2579 debug2("callback start");
2580 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2581 debug2("callback done");
2585 /* Schedule the channel for cleanup/deletion. */
2591 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2600 /* Get the channel number and verify it. */
2601 id = packet_get_int();
2602 c = channel_lookup(id);
2605 logit("Received window adjust for non-open channel %d.", id);
2608 adjust = packet_get_int();
2610 debug2("channel %d: rcvd adjust %u", id, adjust);
2611 c->remote_window += adjust;
2616 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2620 char *host, *originator_string;
2623 remote_id = packet_get_int();
2624 host = packet_get_string(NULL);
2625 host_port = packet_get_int();
2627 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2628 originator_string = packet_get_string(NULL);
2630 originator_string = xstrdup("unknown (remote did not supply name)");
2633 c = channel_connect_to(host, host_port,
2634 "connected socket", originator_string);
2635 xfree(originator_string);
2638 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2639 packet_put_int(remote_id);
2642 c->remote_id = remote_id;
2647 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2650 struct channel_confirm *cc;
2653 /* Reset keepalive timeout */
2654 packet_set_alive_timeouts(0);
2656 id = packet_get_int();
2659 debug2("channel_input_status_confirm: type %d id %d", type, id);
2661 if ((c = channel_lookup(id)) == NULL) {
2662 logit("channel_input_status_confirm: %d: unknown", id);
2666 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2668 cc->cb(type, c, cc->ctx);
2669 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2670 bzero(cc, sizeof(*cc));
2674 /* -- tcp forwarding */
2677 channel_set_af(int af)
2684 * Determine whether or not a port forward listens to loopback, the
2685 * specified address or wildcard. On the client, a specified bind
2686 * address will always override gateway_ports. On the server, a
2687 * gateway_ports of 1 (``yes'') will override the client's specification
2688 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2689 * will bind to whatever address the client asked for.
2691 * Special-case listen_addrs are:
2693 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2694 * "" (empty string), "*" -> wildcard v4/v6
2695 * "localhost" -> loopback v4/v6
2698 channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2699 int is_client, int gateway_ports)
2701 const char *addr = NULL;
2704 if (listen_addr == NULL) {
2705 /* No address specified: default to gateway_ports setting */
2708 } else if (gateway_ports || is_client) {
2709 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2710 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2711 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2712 (!is_client && gateway_ports == 1))
2714 else if (strcmp(listen_addr, "localhost") != 0)
2717 if (wildcardp != NULL)
2718 *wildcardp = wildcard;
2723 channel_setup_fwd_listener(int type, const char *listen_addr,
2724 u_short listen_port, int *allocated_listen_port,
2725 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2728 int sock, r, success = 0, wildcard = 0, is_client;
2729 struct addrinfo hints, *ai, *aitop;
2730 const char *host, *addr;
2731 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2734 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2735 listen_addr : host_to_connect;
2736 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2739 error("No forward host name.");
2742 if (strlen(host) >= NI_MAXHOST) {
2743 error("Forward host name too long.");
2747 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2748 addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2749 is_client, gateway_ports);
2750 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2751 type, wildcard, (addr == NULL) ? "NULL" : addr);
2754 * getaddrinfo returns a loopback address if the hostname is
2755 * set to NULL and hints.ai_flags is not AI_PASSIVE
2757 memset(&hints, 0, sizeof(hints));
2758 hints.ai_family = IPv4or6;
2759 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2760 hints.ai_socktype = SOCK_STREAM;
2761 snprintf(strport, sizeof strport, "%d", listen_port);
2762 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2764 /* This really shouldn't happen */
2765 packet_disconnect("getaddrinfo: fatal error: %s",
2766 ssh_gai_strerror(r));
2768 error("channel_setup_fwd_listener: "
2769 "getaddrinfo(%.64s): %s", addr,
2770 ssh_gai_strerror(r));
2774 if (allocated_listen_port != NULL)
2775 *allocated_listen_port = 0;
2776 for (ai = aitop; ai; ai = ai->ai_next) {
2777 switch (ai->ai_family) {
2779 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2783 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2790 * If allocating a port for -R forwards, then use the
2791 * same port for all address families.
2793 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2794 allocated_listen_port != NULL && *allocated_listen_port > 0)
2795 *lport_p = htons(*allocated_listen_port);
2797 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2798 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2799 error("channel_setup_fwd_listener: getnameinfo failed");
2802 /* Create a port to listen for the host. */
2803 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2805 /* this is no error since kernel may not support ipv6 */
2806 verbose("socket: %.100s", strerror(errno));
2810 channel_set_reuseaddr(sock);
2811 if (ai->ai_family == AF_INET6)
2812 sock_set_v6only(sock);
2814 debug("Local forwarding listening on %s port %s.",
2817 /* Bind the socket to the address. */
2818 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2819 /* address can be in use ipv6 address is already bound */
2821 error("bind: %.100s", strerror(errno));
2823 verbose("bind: %.100s", strerror(errno));
2828 /* Start listening for connections on the socket. */
2829 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2830 error("listen: %.100s", strerror(errno));
2836 * listen_port == 0 requests a dynamically allocated port -
2837 * record what we got.
2839 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2840 allocated_listen_port != NULL &&
2841 *allocated_listen_port == 0) {
2842 *allocated_listen_port = get_sock_port(sock, 1);
2843 debug("Allocated listen port %d",
2844 *allocated_listen_port);
2847 /* Allocate a channel number for the socket. */
2848 c = channel_new("port listener", type, sock, sock, -1,
2849 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2850 0, "port listener", 1);
2851 c->path = xstrdup(host);
2852 c->host_port = port_to_connect;
2853 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2854 if (listen_port == 0 && allocated_listen_port != NULL &&
2855 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2856 c->listening_port = *allocated_listen_port;
2858 c->listening_port = listen_port;
2862 error("channel_setup_fwd_listener: cannot listen to port: %d",
2864 freeaddrinfo(aitop);
2869 channel_cancel_rport_listener(const char *host, u_short port)
2874 for (i = 0; i < channels_alloc; i++) {
2875 Channel *c = channels[i];
2876 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2878 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2879 debug2("%s: close channel %d", __func__, i);
2889 channel_cancel_lport_listener(const char *lhost, u_short lport,
2890 int cport, int gateway_ports)
2894 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
2896 for (i = 0; i < channels_alloc; i++) {
2897 Channel *c = channels[i];
2898 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2900 if (c->listening_port != lport)
2902 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2903 /* skip dynamic forwardings */
2904 if (c->host_port == 0)
2907 if (c->host_port != cport)
2910 if ((c->listening_addr == NULL && addr != NULL) ||
2911 (c->listening_addr != NULL && addr == NULL))
2913 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
2914 debug2("%s: close channel %d", __func__, i);
2923 /* protocol local port fwd, used by ssh (and sshd in v1) */
2925 channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2926 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2928 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2929 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2933 /* protocol v2 remote port fwd, used by sshd */
2935 channel_setup_remote_fwd_listener(const char *listen_address,
2936 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2938 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2939 listen_address, listen_port, allocated_listen_port,
2940 NULL, 0, gateway_ports);
2944 * Translate the requested rfwd listen host to something usable for
2948 channel_rfwd_bind_host(const char *listen_host)
2950 if (listen_host == NULL) {
2951 if (datafellows & SSH_BUG_RFWD_ADDR)
2955 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
2956 if (datafellows & SSH_BUG_RFWD_ADDR)
2965 * Initiate forwarding of connections to port "port" on remote host through
2966 * the secure channel to host:port from local side.
2967 * Returns handle (index) for updating the dynamic listen port with
2968 * channel_update_permitted_opens().
2971 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2972 const char *host_to_connect, u_short port_to_connect)
2974 int type, success = 0, idx = -1;
2976 /* Send the forward request to the remote side. */
2978 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2979 packet_put_cstring("tcpip-forward");
2980 packet_put_char(1); /* boolean: want reply */
2981 packet_put_cstring(channel_rfwd_bind_host(listen_host));
2982 packet_put_int(listen_port);
2984 packet_write_wait();
2985 /* Assume that server accepts the request */
2988 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2989 packet_put_int(listen_port);
2990 packet_put_cstring(host_to_connect);
2991 packet_put_int(port_to_connect);
2993 packet_write_wait();
2995 /* Wait for response from the remote side. */
2996 type = packet_read();
2998 case SSH_SMSG_SUCCESS:
3001 case SSH_SMSG_FAILURE:
3004 /* Unknown packet */
3005 packet_disconnect("Protocol error for port forward request:"
3006 "received packet type %d.", type);
3010 /* Record that connection to this host/port is permitted. */
3011 permitted_opens = xrealloc(permitted_opens,
3012 num_permitted_opens + 1, sizeof(*permitted_opens));
3013 idx = num_permitted_opens++;
3014 permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
3015 permitted_opens[idx].port_to_connect = port_to_connect;
3016 permitted_opens[idx].listen_port = listen_port;
3022 * Request cancellation of remote forwarding of connection host:port from
3026 channel_request_rforward_cancel(const char *host, u_short port)
3033 for (i = 0; i < num_permitted_opens; i++) {
3034 if (permitted_opens[i].host_to_connect != NULL &&
3035 permitted_opens[i].listen_port == port)
3038 if (i >= num_permitted_opens) {
3039 debug("%s: requested forward not found", __func__);
3042 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3043 packet_put_cstring("cancel-tcpip-forward");
3045 packet_put_cstring(channel_rfwd_bind_host(host));
3046 packet_put_int(port);
3049 permitted_opens[i].listen_port = 0;
3050 permitted_opens[i].port_to_connect = 0;
3051 xfree(permitted_opens[i].host_to_connect);
3052 permitted_opens[i].host_to_connect = NULL;
3058 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3059 * listening for the port, and sends back a success reply (or disconnect
3060 * message if there was an error).
3063 channel_input_port_forward_request(int is_root, int gateway_ports)
3065 u_short port, host_port;
3069 /* Get arguments from the packet. */
3070 port = packet_get_int();
3071 hostname = packet_get_string(NULL);
3072 host_port = packet_get_int();
3076 * Check that an unprivileged user is not trying to forward a
3079 if (port < IPPORT_RESERVED && !is_root)
3081 "Requested forwarding of port %d but user is not root.",
3084 packet_disconnect("Dynamic forwarding denied.");
3087 /* Initiate forwarding */
3088 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3089 host_port, gateway_ports);
3091 /* Free the argument string. */
3094 return (success ? 0 : -1);
3098 * Permits opening to any host/port if permitted_opens[] is empty. This is
3099 * usually called by the server, because the user could connect to any port
3100 * anyway, and the server has no way to know but to trust the client anyway.
3103 channel_permit_all_opens(void)
3105 if (num_permitted_opens == 0)
3106 all_opens_permitted = 1;
3110 channel_add_permitted_opens(char *host, int port)
3112 debug("allow port forwarding to host %s port %d", host, port);
3114 permitted_opens = xrealloc(permitted_opens,
3115 num_permitted_opens + 1, sizeof(*permitted_opens));
3116 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3117 permitted_opens[num_permitted_opens].port_to_connect = port;
3118 num_permitted_opens++;
3120 all_opens_permitted = 0;
3124 * Update the listen port for a dynamic remote forward, after
3125 * the actual 'newport' has been allocated. If 'newport' < 0 is
3126 * passed then they entry will be invalidated.
3129 channel_update_permitted_opens(int idx, int newport)
3131 if (idx < 0 || idx >= num_permitted_opens) {
3132 debug("channel_update_permitted_opens: index out of range:"
3133 " %d num_permitted_opens %d", idx, num_permitted_opens);
3136 debug("%s allowed port %d for forwarding to host %s port %d",
3137 newport > 0 ? "Updating" : "Removing",
3139 permitted_opens[idx].host_to_connect,
3140 permitted_opens[idx].port_to_connect);
3142 permitted_opens[idx].listen_port =
3143 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3145 permitted_opens[idx].listen_port = 0;
3146 permitted_opens[idx].port_to_connect = 0;
3147 xfree(permitted_opens[idx].host_to_connect);
3148 permitted_opens[idx].host_to_connect = NULL;
3153 channel_add_adm_permitted_opens(char *host, int port)
3155 debug("config allows port forwarding to host %s port %d", host, port);
3157 permitted_adm_opens = xrealloc(permitted_adm_opens,
3158 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3159 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3161 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3162 return ++num_adm_permitted_opens;
3166 channel_disable_adm_local_opens(void)
3168 if (num_adm_permitted_opens == 0) {
3169 permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3170 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3172 num_adm_permitted_opens = 1;
3177 channel_clear_permitted_opens(void)
3181 for (i = 0; i < num_permitted_opens; i++)
3182 if (permitted_opens[i].host_to_connect != NULL)
3183 xfree(permitted_opens[i].host_to_connect);
3184 if (num_permitted_opens > 0) {
3185 xfree(permitted_opens);
3186 permitted_opens = NULL;
3188 num_permitted_opens = 0;
3192 channel_clear_adm_permitted_opens(void)
3196 for (i = 0; i < num_adm_permitted_opens; i++)
3197 if (permitted_adm_opens[i].host_to_connect != NULL)
3198 xfree(permitted_adm_opens[i].host_to_connect);
3199 if (num_adm_permitted_opens > 0) {
3200 xfree(permitted_adm_opens);
3201 permitted_adm_opens = NULL;
3203 num_adm_permitted_opens = 0;
3207 channel_print_adm_permitted_opens(void)
3211 printf("permitopen");
3212 if (num_adm_permitted_opens == 0) {
3216 for (i = 0; i < num_adm_permitted_opens; i++)
3217 if (permitted_adm_opens[i].host_to_connect == NULL)
3220 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3221 permitted_adm_opens[i].port_to_connect);
3225 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3227 permitopen_port(const char *p)
3231 if (strcmp(p, "*") == 0)
3232 return FWD_PERMIT_ANY_PORT;
3233 if ((port = a2port(p)) > 0)
3239 port_match(u_short allowedport, u_short requestedport)
3241 if (allowedport == FWD_PERMIT_ANY_PORT ||
3242 allowedport == requestedport)
3247 /* Try to start non-blocking connect to next host in cctx list */
3249 connect_next(struct channel_connect *cctx)
3251 int sock, saved_errno;
3252 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3254 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3255 if (cctx->ai->ai_family != AF_INET &&
3256 cctx->ai->ai_family != AF_INET6)
3258 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3259 ntop, sizeof(ntop), strport, sizeof(strport),
3260 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3261 error("connect_next: getnameinfo failed");
3264 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3265 cctx->ai->ai_protocol)) == -1) {
3266 if (cctx->ai->ai_next == NULL)
3267 error("socket: %.100s", strerror(errno));
3269 verbose("socket: %.100s", strerror(errno));
3272 if (set_nonblock(sock) == -1)
3273 fatal("%s: set_nonblock(%d)", __func__, sock);
3274 if (connect(sock, cctx->ai->ai_addr,
3275 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3276 debug("connect_next: host %.100s ([%.100s]:%s): "
3277 "%.100s", cctx->host, ntop, strport,
3279 saved_errno = errno;
3281 errno = saved_errno;
3282 continue; /* fail -- try next */
3284 debug("connect_next: host %.100s ([%.100s]:%s) "
3285 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3286 cctx->ai = cctx->ai->ai_next;
3294 channel_connect_ctx_free(struct channel_connect *cctx)
3298 freeaddrinfo(cctx->aitop);
3299 bzero(cctx, sizeof(*cctx));
3301 cctx->ai = cctx->aitop = NULL;
3304 /* Return CONNECTING channel to remote host, port */
3306 connect_to(const char *host, u_short port, char *ctype, char *rname)
3308 struct addrinfo hints;
3311 char strport[NI_MAXSERV];
3312 struct channel_connect cctx;
3315 memset(&cctx, 0, sizeof(cctx));
3316 memset(&hints, 0, sizeof(hints));
3317 hints.ai_family = IPv4or6;
3318 hints.ai_socktype = SOCK_STREAM;
3319 snprintf(strport, sizeof strport, "%d", port);
3320 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3321 error("connect_to %.100s: unknown host (%s)", host,
3322 ssh_gai_strerror(gaierr));
3326 cctx.host = xstrdup(host);
3328 cctx.ai = cctx.aitop;
3330 if ((sock = connect_next(&cctx)) == -1) {
3331 error("connect to %.100s port %d failed: %s",
3332 host, port, strerror(errno));
3333 channel_connect_ctx_free(&cctx);
3336 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3337 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3338 c->connect_ctx = cctx;
3343 channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3347 for (i = 0; i < num_permitted_opens; i++) {
3348 if (permitted_opens[i].host_to_connect != NULL &&
3349 port_match(permitted_opens[i].listen_port, listen_port)) {
3351 permitted_opens[i].host_to_connect,
3352 permitted_opens[i].port_to_connect, ctype, rname);
3355 error("WARNING: Server requests forwarding for unknown listen_port %d",
3360 /* Check if connecting to that port is permitted and connect. */
3362 channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3364 int i, permit, permit_adm = 1;
3366 permit = all_opens_permitted;
3368 for (i = 0; i < num_permitted_opens; i++)
3369 if (permitted_opens[i].host_to_connect != NULL &&
3370 port_match(permitted_opens[i].port_to_connect, port) &&
3371 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3375 if (num_adm_permitted_opens > 0) {
3377 for (i = 0; i < num_adm_permitted_opens; i++)
3378 if (permitted_adm_opens[i].host_to_connect != NULL &&
3379 port_match(permitted_adm_opens[i].port_to_connect, port) &&
3380 strcmp(permitted_adm_opens[i].host_to_connect, host)
3385 if (!permit || !permit_adm) {
3386 logit("Received request to connect to host %.100s port %d, "
3387 "but the request was denied.", host, port);
3390 return connect_to(host, port, ctype, rname);
3394 channel_send_window_changes(void)
3399 for (i = 0; i < channels_alloc; i++) {
3400 if (channels[i] == NULL || !channels[i]->client_tty ||
3401 channels[i]->type != SSH_CHANNEL_OPEN)
3403 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3405 channel_request_start(i, "window-change", 0);
3406 packet_put_int((u_int)ws.ws_col);
3407 packet_put_int((u_int)ws.ws_row);
3408 packet_put_int((u_int)ws.ws_xpixel);
3409 packet_put_int((u_int)ws.ws_ypixel);
3414 /* -- X11 forwarding */
3417 * Creates an internet domain socket for listening for X11 connections.
3418 * Returns 0 and a suitable display number for the DISPLAY variable
3419 * stored in display_numberp , or -1 if an error occurs.
3422 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3423 int single_connection, u_int *display_numberp, int **chanids)
3426 int display_number, sock;
3428 struct addrinfo hints, *ai, *aitop;
3429 char strport[NI_MAXSERV];
3430 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3432 if (chanids == NULL)
3435 for (display_number = x11_display_offset;
3436 display_number < MAX_DISPLAYS;
3438 port = 6000 + display_number;
3439 memset(&hints, 0, sizeof(hints));
3440 hints.ai_family = IPv4or6;
3441 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3442 hints.ai_socktype = SOCK_STREAM;
3443 snprintf(strport, sizeof strport, "%d", port);
3444 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3445 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3448 for (ai = aitop; ai; ai = ai->ai_next) {
3449 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3451 sock = socket(ai->ai_family, ai->ai_socktype,
3454 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3456 && (errno != EPFNOSUPPORT)
3459 error("socket: %.100s", strerror(errno));
3460 freeaddrinfo(aitop);
3463 debug("x11_create_display_inet: Socket family %d not supported",
3468 if (ai->ai_family == AF_INET6)
3469 sock_set_v6only(sock);
3470 if (x11_use_localhost)
3471 channel_set_reuseaddr(sock);
3472 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3473 debug2("bind port %d: %.100s", port, strerror(errno));
3476 for (n = 0; n < num_socks; n++) {
3482 socks[num_socks++] = sock;
3483 if (num_socks == NUM_SOCKS)
3486 freeaddrinfo(aitop);
3490 if (display_number >= MAX_DISPLAYS) {
3491 error("Failed to allocate internet-domain X11 display socket.");
3494 /* Start listening for connections on the socket. */
3495 for (n = 0; n < num_socks; n++) {
3497 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3498 error("listen: %.100s", strerror(errno));
3504 /* Allocate a channel for each socket. */
3505 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3506 for (n = 0; n < num_socks; n++) {
3508 nc = channel_new("x11 listener",
3509 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3510 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3511 0, "X11 inet listener", 1);
3512 nc->single_connection = single_connection;
3513 (*chanids)[n] = nc->self;
3517 /* Return the display number for the DISPLAY environment variable. */
3518 *display_numberp = display_number;
3523 connect_local_xsocket_path(const char *pathname)
3526 struct sockaddr_un addr;
3528 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3530 error("socket: %.100s", strerror(errno));
3531 memset(&addr, 0, sizeof(addr));
3532 addr.sun_family = AF_UNIX;
3533 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3534 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3537 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3542 connect_local_xsocket(u_int dnr)
3545 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3546 return connect_local_xsocket_path(buf);
3550 x11_connect_display(void)
3552 u_int display_number;
3553 const char *display;
3554 char buf[1024], *cp;
3555 struct addrinfo hints, *ai, *aitop;
3556 char strport[NI_MAXSERV];
3557 int gaierr, sock = 0;
3559 /* Try to open a socket for the local X server. */
3560 display = getenv("DISPLAY");
3562 error("DISPLAY not set.");
3566 * Now we decode the value of the DISPLAY variable and make a
3567 * connection to the real X server.
3570 /* Check if the display is from launchd. */
3572 if (strncmp(display, "/tmp/launch", 11) == 0) {
3573 sock = connect_local_xsocket_path(display);
3577 /* OK, we now have a connection to the display. */
3582 * Check if it is a unix domain socket. Unix domain displays are in
3583 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3585 if (strncmp(display, "unix:", 5) == 0 ||
3586 display[0] == ':') {
3587 /* Connect to the unix domain socket. */
3588 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3589 error("Could not parse display number from DISPLAY: %.100s",
3593 /* Create a socket. */
3594 sock = connect_local_xsocket(display_number);
3598 /* OK, we now have a connection to the display. */
3602 * Connect to an inet socket. The DISPLAY value is supposedly
3603 * hostname:d[.s], where hostname may also be numeric IP address.
3605 strlcpy(buf, display, sizeof(buf));
3606 cp = strchr(buf, ':');
3608 error("Could not find ':' in DISPLAY: %.100s", display);
3612 /* buf now contains the host name. But first we parse the display number. */
3613 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3614 error("Could not parse display number from DISPLAY: %.100s",
3619 /* Look up the host address */
3620 memset(&hints, 0, sizeof(hints));
3621 hints.ai_family = IPv4or6;
3622 hints.ai_socktype = SOCK_STREAM;
3623 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3624 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3625 error("%.100s: unknown host. (%s)", buf,
3626 ssh_gai_strerror(gaierr));
3629 for (ai = aitop; ai; ai = ai->ai_next) {
3630 /* Create a socket. */
3631 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3633 debug2("socket: %.100s", strerror(errno));
3636 /* Connect it to the display. */
3637 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3638 debug2("connect %.100s port %u: %.100s", buf,
3639 6000 + display_number, strerror(errno));
3646 freeaddrinfo(aitop);
3648 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3657 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3658 * the remote channel number. We should do whatever we want, and respond
3659 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3664 x11_input_open(int type, u_int32_t seq, void *ctxt)
3667 int remote_id, sock = 0;
3670 debug("Received X11 open request.");
3672 remote_id = packet_get_int();
3674 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3675 remote_host = packet_get_string(NULL);
3677 remote_host = xstrdup("unknown (remote did not supply name)");
3681 /* Obtain a connection to the real X display. */
3682 sock = x11_connect_display();
3684 /* Allocate a channel for this connection. */
3685 c = channel_new("connected x11 socket",
3686 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3688 c->remote_id = remote_id;
3693 /* Send refusal to the remote host. */
3694 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3695 packet_put_int(remote_id);
3697 /* Send a confirmation to the remote host. */
3698 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3699 packet_put_int(remote_id);
3700 packet_put_int(c->self);
3705 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3708 deny_input_open(int type, u_int32_t seq, void *ctxt)
3710 int rchan = packet_get_int();
3713 case SSH_SMSG_AGENT_OPEN:
3714 error("Warning: ssh server tried agent forwarding.");
3716 case SSH_SMSG_X11_OPEN:
3717 error("Warning: ssh server tried X11 forwarding.");
3720 error("deny_input_open: type %d", type);
3723 error("Warning: this is probably a break-in attempt by a malicious server.");
3724 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3725 packet_put_int(rchan);
3730 * Requests forwarding of X11 connections, generates fake authentication
3731 * data, and enables authentication spoofing.
3732 * This should be called in the client only.
3735 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3736 const char *proto, const char *data, int want_reply)
3738 u_int data_len = (u_int) strlen(data) / 2;
3745 if (x11_saved_display == NULL)
3746 x11_saved_display = xstrdup(disp);
3747 else if (strcmp(disp, x11_saved_display) != 0) {
3748 error("x11_request_forwarding_with_spoofing: different "
3749 "$DISPLAY already forwarded");
3753 cp = strchr(disp, ':');
3755 cp = strchr(cp, '.');
3757 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3761 if (x11_saved_proto == NULL) {
3762 /* Save protocol name. */
3763 x11_saved_proto = xstrdup(proto);
3765 * Extract real authentication data and generate fake data
3766 * of the same length.
3768 x11_saved_data = xmalloc(data_len);
3769 x11_fake_data = xmalloc(data_len);
3770 for (i = 0; i < data_len; i++) {
3771 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3772 fatal("x11_request_forwarding: bad "
3773 "authentication data: %.100s", data);
3776 x11_saved_data[i] = value;
3777 x11_fake_data[i] = rnd & 0xff;
3780 x11_saved_data_len = data_len;
3781 x11_fake_data_len = data_len;
3784 /* Convert the fake data into hex. */
3785 new_data = tohex(x11_fake_data, data_len);
3787 /* Send the request packet. */
3789 channel_request_start(client_session_id, "x11-req", want_reply);
3790 packet_put_char(0); /* XXX bool single connection */
3792 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3794 packet_put_cstring(proto);
3795 packet_put_cstring(new_data);
3796 packet_put_int(screen_number);
3798 packet_write_wait();
3803 /* -- agent forwarding */
3805 /* Sends a message to the server to request authentication fd forwarding. */
3808 auth_request_forwarding(void)
3810 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3812 packet_write_wait();