1 /* $OpenBSD: channels.c,v 1.309 2010/08/05 13:08:42 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;
129 * If this is true, all opens are permitted. This is the case on the server
130 * on which we have to trust the client anyway, and the user could do
131 * anything after logging in anyway.
133 static int all_opens_permitted = 0;
136 /* -- X11 forwarding */
138 /* Maximum number of fake X11 displays to try. */
139 #define MAX_DISPLAYS 1000
141 /* Saved X11 local (client) display. */
142 static char *x11_saved_display = NULL;
144 /* Saved X11 authentication protocol name. */
145 static char *x11_saved_proto = NULL;
147 /* Saved X11 authentication data. This is the real data. */
148 static char *x11_saved_data = NULL;
149 static u_int x11_saved_data_len = 0;
152 * Fake X11 authentication data. This is what the server will be sending us;
153 * we should replace any occurrences of this by the real data.
155 static u_char *x11_fake_data = NULL;
156 static u_int x11_fake_data_len;
159 /* -- agent forwarding */
163 /* AF_UNSPEC or AF_INET or AF_INET6 */
164 static int IPv4or6 = AF_UNSPEC;
167 static void port_open_helper(Channel *c, char *rtype);
169 /* non-blocking connect helpers */
170 static int connect_next(struct channel_connect *);
171 static void channel_connect_ctx_free(struct channel_connect *);
174 static int hpn_disabled = 0;
175 static int hpn_buffer_size = 2 * 1024 * 1024;
177 /* -- channel core */
182 channel_by_id(int id)
186 if (id < 0 || (u_int)id >= channels_alloc) {
187 logit("channel_by_id: %d: bad id", id);
192 logit("channel_by_id: %d: bad id: channel free", id);
199 * Returns the channel if it is allowed to receive protocol messages.
200 * Private channels, like listening sockets, may not receive messages.
203 channel_lookup(int id)
207 if ((c = channel_by_id(id)) == NULL)
211 case SSH_CHANNEL_X11_OPEN:
212 case SSH_CHANNEL_LARVAL:
213 case SSH_CHANNEL_CONNECTING:
214 case SSH_CHANNEL_DYNAMIC:
215 case SSH_CHANNEL_OPENING:
216 case SSH_CHANNEL_OPEN:
217 case SSH_CHANNEL_INPUT_DRAINING:
218 case SSH_CHANNEL_OUTPUT_DRAINING:
221 logit("Non-public channel %d, type %d.", id, c->type);
226 * Register filedescriptors for a channel, used when allocating a channel or
227 * when the channel consumer/producer is ready, e.g. shell exec'd
230 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
231 int extusage, int nonblock, int is_tty)
233 /* Update the maximum file descriptor value. */
234 channel_max_fd = MAX(channel_max_fd, rfd);
235 channel_max_fd = MAX(channel_max_fd, wfd);
236 channel_max_fd = MAX(channel_max_fd, efd);
239 fcntl(rfd, F_SETFD, FD_CLOEXEC);
240 if (wfd != -1 && wfd != rfd)
241 fcntl(wfd, F_SETFD, FD_CLOEXEC);
242 if (efd != -1 && efd != rfd && efd != wfd)
243 fcntl(efd, F_SETFD, FD_CLOEXEC);
247 c->sock = (rfd == wfd) ? rfd : -1;
249 c->extended_usage = extusage;
251 if ((c->isatty = is_tty) != 0)
252 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
253 c->wfd_isatty = is_tty || isatty(c->wfd);
255 /* enable nonblocking mode */
267 * Allocate a new channel object and set its type and socket. This will cause
268 * remote_name to be freed.
271 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
272 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
278 /* Do initial allocation if this is the first call. */
279 if (channels_alloc == 0) {
281 channels = xcalloc(channels_alloc, sizeof(Channel *));
282 for (i = 0; i < channels_alloc; i++)
285 /* Try to find a free slot where to put the new channel. */
286 for (found = -1, i = 0; i < channels_alloc; i++)
287 if (channels[i] == NULL) {
288 /* Found a free slot. */
293 /* There are no free slots. Take last+1 slot and expand the array. */
294 found = channels_alloc;
295 if (channels_alloc > 10000)
296 fatal("channel_new: internal error: channels_alloc %d "
297 "too big.", channels_alloc);
298 channels = xrealloc(channels, channels_alloc + 10,
300 channels_alloc += 10;
301 debug2("channel: expanding %d", channels_alloc);
302 for (i = found; i < channels_alloc; i++)
305 /* Initialize and return new channel. */
306 c = channels[found] = xcalloc(1, sizeof(Channel));
307 buffer_init(&c->input);
308 buffer_init(&c->output);
309 buffer_init(&c->extended);
311 c->ostate = CHAN_OUTPUT_OPEN;
312 c->istate = CHAN_INPUT_OPEN;
314 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;
322 c->dynamic_window = 0;
324 c->remote_name = xstrdup(remote_name);
325 c->remote_window = 0;
326 c->remote_maxpacket = 0;
328 c->single_connection = 0;
329 c->detach_user = NULL;
331 c->open_confirm = NULL;
332 c->open_confirm_ctx = NULL;
333 c->input_filter = NULL;
334 c->output_filter = NULL;
335 c->filter_ctx = NULL;
336 c->filter_cleanup = NULL;
341 c->delayed = 1; /* prevent call to channel_post handler */
342 TAILQ_INIT(&c->status_confirms);
343 debug("channel %d: new [%s]", found, remote_name);
348 channel_find_maxfd(void)
354 for (i = 0; i < channels_alloc; i++) {
357 max = MAX(max, c->rfd);
358 max = MAX(max, c->wfd);
359 max = MAX(max, c->efd);
366 channel_close_fd(int *fdp)
368 int ret = 0, fd = *fdp;
373 if (fd == channel_max_fd)
374 channel_max_fd = channel_find_maxfd();
379 /* Close all channel fd/socket. */
381 channel_close_fds(Channel *c)
383 debug3("channel %d: close_fds r %d w %d e %d",
384 c->self, c->rfd, c->wfd, c->efd);
386 channel_close_fd(&c->sock);
387 channel_close_fd(&c->rfd);
388 channel_close_fd(&c->wfd);
389 channel_close_fd(&c->efd);
392 /* Free the channel and close its fd/socket. */
394 channel_free(Channel *c)
398 struct channel_confirm *cc;
400 for (n = 0, i = 0; i < channels_alloc; i++)
403 debug("channel %d: free: %s, nchannels %u", c->self,
404 c->remote_name ? c->remote_name : "???", n);
406 s = channel_open_message();
407 debug3("channel %d: status: %s", c->self, s);
411 shutdown(c->sock, SHUT_RDWR);
412 channel_close_fds(c);
413 buffer_free(&c->input);
414 buffer_free(&c->output);
415 buffer_free(&c->extended);
416 if (c->remote_name) {
417 xfree(c->remote_name);
418 c->remote_name = 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);
821 int channel_tcpwinsz () {
822 u_int32_t tcpwinsz = 0;
823 socklen_t optsz = sizeof(tcpwinsz);
826 /* if we aren't on a socket return 128KB*/
827 if(!packet_connection_is_on_socket())
829 ret = getsockopt(packet_get_connection_in(),
830 SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
831 /* return no more than 64MB */
832 if ((ret == 0) && tcpwinsz > BUFFER_MAX_LEN_HPN)
833 tcpwinsz = BUFFER_MAX_LEN_HPN;
834 debug2("tcpwinsz: %d for connection: %d", tcpwinsz,
835 packet_get_connection_in());
840 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
842 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
844 /* check buffer limits */
845 if ((!c->tcpwinsz) || (c->dynamic_window > 0))
846 c->tcpwinsz = channel_tcpwinsz();
848 limit = MIN(limit, 2 * c->tcpwinsz);
850 if (c->istate == CHAN_INPUT_OPEN &&
852 buffer_len(&c->input) < limit &&
853 buffer_check_alloc(&c->input, CHAN_RBUF))
854 FD_SET(c->rfd, readset);
855 if (c->ostate == CHAN_OUTPUT_OPEN ||
856 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
857 if (buffer_len(&c->output) > 0) {
858 FD_SET(c->wfd, writeset);
859 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
860 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
861 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
862 c->self, c->efd, buffer_len(&c->extended));
867 /** XXX check close conditions, too */
868 if (compat20 && c->efd != -1 &&
869 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
870 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
871 buffer_len(&c->extended) > 0)
872 FD_SET(c->efd, writeset);
873 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
874 (c->extended_usage == CHAN_EXTENDED_READ ||
875 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
876 buffer_len(&c->extended) < c->remote_window)
877 FD_SET(c->efd, readset);
879 /* XXX: What about efd? races? */
884 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
886 if (buffer_len(&c->input) == 0) {
887 packet_start(SSH_MSG_CHANNEL_CLOSE);
888 packet_put_int(c->remote_id);
890 c->type = SSH_CHANNEL_CLOSED;
891 debug2("channel %d: closing after input drain.", c->self);
897 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
899 if (buffer_len(&c->output) == 0)
902 FD_SET(c->sock, writeset);
906 * This is a special state for X11 authentication spoofing. An opened X11
907 * connection (when authentication spoofing is being done) remains in this
908 * state until the first packet has been completely read. The authentication
909 * data in that packet is then substituted by the real data if it matches the
910 * fake data, and the channel is put into normal mode.
911 * XXX All this happens at the client side.
912 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
915 x11_open_helper(Buffer *b)
918 u_int proto_len, data_len;
920 /* Check if the fixed size part of the packet is in buffer. */
921 if (buffer_len(b) < 12)
924 /* Parse the lengths of variable-length fields. */
926 if (ucp[0] == 0x42) { /* Byte order MSB first. */
927 proto_len = 256 * ucp[6] + ucp[7];
928 data_len = 256 * ucp[8] + ucp[9];
929 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
930 proto_len = ucp[6] + 256 * ucp[7];
931 data_len = ucp[8] + 256 * ucp[9];
933 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
938 /* Check if the whole packet is in buffer. */
940 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
943 /* Check if authentication protocol matches. */
944 if (proto_len != strlen(x11_saved_proto) ||
945 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
946 debug2("X11 connection uses different authentication protocol.");
949 /* Check if authentication data matches our fake data. */
950 if (data_len != x11_fake_data_len ||
951 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
952 x11_fake_data, x11_fake_data_len) != 0) {
953 debug2("X11 auth data does not match fake data.");
956 /* Check fake data length */
957 if (x11_fake_data_len != x11_saved_data_len) {
958 error("X11 fake_data_len %d != saved_data_len %d",
959 x11_fake_data_len, x11_saved_data_len);
963 * Received authentication protocol and data match
964 * our fake data. Substitute the fake data with real
967 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
968 x11_saved_data, x11_saved_data_len);
973 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
975 int ret = x11_open_helper(&c->output);
978 /* Start normal processing for the channel. */
979 c->type = SSH_CHANNEL_OPEN;
980 channel_pre_open_13(c, readset, writeset);
981 } else if (ret == -1) {
983 * We have received an X11 connection that has bad
984 * authentication information.
986 logit("X11 connection rejected because of wrong authentication.");
987 buffer_clear(&c->input);
988 buffer_clear(&c->output);
989 channel_close_fd(&c->sock);
991 c->type = SSH_CHANNEL_CLOSED;
992 packet_start(SSH_MSG_CHANNEL_CLOSE);
993 packet_put_int(c->remote_id);
999 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1001 int ret = x11_open_helper(&c->output);
1003 /* c->force_drain = 1; */
1006 c->type = SSH_CHANNEL_OPEN;
1007 channel_pre_open(c, readset, writeset);
1008 } else if (ret == -1) {
1009 logit("X11 connection rejected because of wrong authentication.");
1010 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1011 chan_read_failed(c);
1012 buffer_clear(&c->input);
1014 buffer_clear(&c->output);
1015 /* for proto v1, the peer will send an IEOF */
1017 chan_write_failed(c);
1019 c->type = SSH_CHANNEL_OPEN;
1020 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1025 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1027 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1028 buffer_check_alloc(&c->input, CHAN_RBUF))
1029 FD_SET(c->rfd, readset);
1030 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1031 /* clear buffer immediately (discard any partial packet) */
1032 buffer_clear(&c->input);
1034 /* Start output drain. XXX just kill chan? */
1035 chan_rcvd_oclose(c);
1037 if (c->ostate == CHAN_OUTPUT_OPEN ||
1038 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1039 if (buffer_len(&c->output) > 0)
1040 FD_SET(c->wfd, writeset);
1041 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1046 /* try to decode a socks4 header */
1049 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1052 u_int len, have, i, found, need;
1057 u_int16_t dest_port;
1058 struct in_addr dest_addr;
1061 debug2("channel %d: decode socks4", c->self);
1063 have = buffer_len(&c->input);
1064 len = sizeof(s4_req);
1067 p = buffer_ptr(&c->input);
1070 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1071 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1072 debug2("channel %d: socks4a request", c->self);
1073 /* ... and needs an extra string (the hostname) */
1076 /* Check for terminating NUL on the string(s) */
1077 for (found = 0, i = len; i < have; i++) {
1084 /* the peer is probably sending garbage */
1085 debug("channel %d: decode socks4: too long",
1092 buffer_get(&c->input, (char *)&s4_req.version, 1);
1093 buffer_get(&c->input, (char *)&s4_req.command, 1);
1094 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1095 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1096 have = buffer_len(&c->input);
1097 p = buffer_ptr(&c->input);
1099 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1100 len++; /* trailing '\0' */
1102 fatal("channel %d: decode socks4: len %d > have %d",
1103 c->self, len, have);
1104 strlcpy(username, p, sizeof(username));
1105 buffer_consume(&c->input, len);
1107 if (c->path != NULL) {
1111 if (need == 1) { /* SOCKS4: one string */
1112 host = inet_ntoa(s4_req.dest_addr);
1113 c->path = xstrdup(host);
1114 } else { /* SOCKS4A: two strings */
1115 have = buffer_len(&c->input);
1116 p = buffer_ptr(&c->input);
1118 debug2("channel %d: decode socks4a: host %s/%d",
1120 len++; /* trailing '\0' */
1122 fatal("channel %d: decode socks4a: len %d > have %d",
1123 c->self, len, have);
1124 if (len > NI_MAXHOST) {
1125 error("channel %d: hostname \"%.100s\" too long",
1129 c->path = xstrdup(p);
1130 buffer_consume(&c->input, len);
1132 c->host_port = ntohs(s4_req.dest_port);
1134 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1135 c->self, c->path, c->host_port, s4_req.command);
1137 if (s4_req.command != 1) {
1138 debug("channel %d: cannot handle: %s cn %d",
1139 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1142 s4_rsp.version = 0; /* vn: 0 for reply */
1143 s4_rsp.command = 90; /* cd: req granted */
1144 s4_rsp.dest_port = 0; /* ignored */
1145 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1146 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1150 /* try to decode a socks5 header */
1151 #define SSH_SOCKS5_AUTHDONE 0x1000
1152 #define SSH_SOCKS5_NOAUTH 0x00
1153 #define SSH_SOCKS5_IPV4 0x01
1154 #define SSH_SOCKS5_DOMAIN 0x03
1155 #define SSH_SOCKS5_IPV6 0x04
1156 #define SSH_SOCKS5_CONNECT 0x01
1157 #define SSH_SOCKS5_SUCCESS 0x00
1161 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1169 u_int16_t dest_port;
1170 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1171 u_int have, need, i, found, nmethods, addrlen, af;
1173 debug2("channel %d: decode socks5", c->self);
1174 p = buffer_ptr(&c->input);
1177 have = buffer_len(&c->input);
1178 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1179 /* format: ver | nmethods | methods */
1183 if (have < nmethods + 2)
1185 /* look for method: "NO AUTHENTICATION REQUIRED" */
1186 for (found = 0, i = 2; i < nmethods + 2; i++) {
1187 if (p[i] == SSH_SOCKS5_NOAUTH) {
1193 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1197 buffer_consume(&c->input, nmethods + 2);
1198 buffer_put_char(&c->output, 0x05); /* version */
1199 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1200 FD_SET(c->sock, writeset);
1201 c->flags |= SSH_SOCKS5_AUTHDONE;
1202 debug2("channel %d: socks5 auth done", c->self);
1203 return 0; /* need more */
1205 debug2("channel %d: socks5 post auth", c->self);
1206 if (have < sizeof(s5_req)+1)
1207 return 0; /* need more */
1208 memcpy(&s5_req, p, sizeof(s5_req));
1209 if (s5_req.version != 0x05 ||
1210 s5_req.command != SSH_SOCKS5_CONNECT ||
1211 s5_req.reserved != 0x00) {
1212 debug2("channel %d: only socks5 connect supported", c->self);
1215 switch (s5_req.atyp){
1216 case SSH_SOCKS5_IPV4:
1220 case SSH_SOCKS5_DOMAIN:
1221 addrlen = p[sizeof(s5_req)];
1224 case SSH_SOCKS5_IPV6:
1229 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1232 need = sizeof(s5_req) + addrlen + 2;
1233 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1237 buffer_consume(&c->input, sizeof(s5_req));
1238 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1239 buffer_consume(&c->input, 1); /* host string length */
1240 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1241 buffer_get(&c->input, (char *)&dest_port, 2);
1242 dest_addr[addrlen] = '\0';
1243 if (c->path != NULL) {
1247 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1248 if (addrlen >= NI_MAXHOST) {
1249 error("channel %d: dynamic request: socks5 hostname "
1250 "\"%.100s\" too long", c->self, dest_addr);
1253 c->path = xstrdup(dest_addr);
1255 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1257 c->path = xstrdup(ntop);
1259 c->host_port = ntohs(dest_port);
1261 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1262 c->self, c->path, c->host_port, s5_req.command);
1264 s5_rsp.version = 0x05;
1265 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1266 s5_rsp.reserved = 0; /* ignored */
1267 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1268 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1269 dest_port = 0; /* ignored */
1271 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1272 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1273 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1278 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1283 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1286 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1287 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1288 0, "stdio-forward", /*nonblock*/0);
1290 c->path = xstrdup(host_to_connect);
1291 c->host_port = port_to_connect;
1292 c->listening_port = 0;
1295 channel_register_fds(c, in, out, -1, 0, 1, 0);
1296 port_open_helper(c, "direct-tcpip");
1301 /* dynamic port forwarding */
1303 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1309 have = buffer_len(&c->input);
1310 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1311 /* buffer_dump(&c->input); */
1312 /* check if the fixed size part of the packet is in buffer. */
1315 FD_SET(c->sock, readset);
1318 /* try to guess the protocol */
1319 p = buffer_ptr(&c->input);
1322 ret = channel_decode_socks4(c, readset, writeset);
1325 ret = channel_decode_socks5(c, readset, writeset);
1333 } else if (ret == 0) {
1334 debug2("channel %d: pre_dynamic: need more", c->self);
1336 FD_SET(c->sock, readset);
1338 /* switch to the next state */
1339 c->type = SSH_CHANNEL_OPENING;
1340 port_open_helper(c, "direct-tcpip");
1344 /* This is our fake X11 server socket. */
1347 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1350 struct sockaddr_storage addr;
1353 char buf[16384], *remote_ipaddr;
1356 if (FD_ISSET(c->sock, readset)) {
1357 debug("X11 connection requested.");
1358 addrlen = sizeof(addr);
1359 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1360 if (c->single_connection) {
1361 debug2("single_connection: closing X11 listener.");
1362 channel_close_fd(&c->sock);
1366 error("accept: %.100s", strerror(errno));
1369 set_nodelay(newsock);
1370 remote_ipaddr = get_peer_ipaddr(newsock);
1371 remote_port = get_peer_port(newsock);
1372 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1373 remote_ipaddr, remote_port);
1375 nc = channel_new("accepted x11 socket",
1376 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1377 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1379 packet_start(SSH2_MSG_CHANNEL_OPEN);
1380 packet_put_cstring("x11");
1381 packet_put_int(nc->self);
1382 packet_put_int(nc->local_window_max);
1383 packet_put_int(nc->local_maxpacket);
1384 /* originator ipaddr and port */
1385 packet_put_cstring(remote_ipaddr);
1386 if (datafellows & SSH_BUG_X11FWD) {
1387 debug2("ssh2 x11 bug compat mode");
1389 packet_put_int(remote_port);
1393 packet_start(SSH_SMSG_X11_OPEN);
1394 packet_put_int(nc->self);
1395 if (packet_get_protocol_flags() &
1396 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1397 packet_put_cstring(buf);
1400 xfree(remote_ipaddr);
1405 port_open_helper(Channel *c, char *rtype)
1409 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1410 int remote_port = get_peer_port(c->sock);
1412 if (remote_port == -1) {
1413 /* Fake addr/port to appease peers that validate it (Tectia) */
1414 xfree(remote_ipaddr);
1415 remote_ipaddr = xstrdup("127.0.0.1");
1416 remote_port = 65535;
1419 direct = (strcmp(rtype, "direct-tcpip") == 0);
1421 snprintf(buf, sizeof buf,
1422 "%s: listening port %d for %.100s port %d, "
1423 "connect from %.200s port %d",
1424 rtype, c->listening_port, c->path, c->host_port,
1425 remote_ipaddr, remote_port);
1427 xfree(c->remote_name);
1428 c->remote_name = xstrdup(buf);
1431 packet_start(SSH2_MSG_CHANNEL_OPEN);
1432 packet_put_cstring(rtype);
1433 packet_put_int(c->self);
1434 packet_put_int(c->local_window_max);
1435 packet_put_int(c->local_maxpacket);
1437 /* target host, port */
1438 packet_put_cstring(c->path);
1439 packet_put_int(c->host_port);
1441 /* listen address, port */
1442 packet_put_cstring(c->path);
1443 packet_put_int(c->listening_port);
1445 /* originator host and port */
1446 packet_put_cstring(remote_ipaddr);
1447 packet_put_int((u_int)remote_port);
1450 packet_start(SSH_MSG_PORT_OPEN);
1451 packet_put_int(c->self);
1452 packet_put_cstring(c->path);
1453 packet_put_int(c->host_port);
1454 if (packet_get_protocol_flags() &
1455 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1456 packet_put_cstring(c->remote_name);
1459 xfree(remote_ipaddr);
1463 channel_set_reuseaddr(int fd)
1468 * Set socket options.
1469 * Allow local port reuse in TIME_WAIT.
1471 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1472 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1476 * This socket is listening for connections to a forwarded TCP/IP port.
1480 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1483 struct sockaddr_storage addr;
1484 int newsock, nextstate;
1488 if (FD_ISSET(c->sock, readset)) {
1489 debug("Connection to port %d forwarding "
1490 "to %.100s port %d requested.",
1491 c->listening_port, c->path, c->host_port);
1493 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1494 nextstate = SSH_CHANNEL_OPENING;
1495 rtype = "forwarded-tcpip";
1497 if (c->host_port == 0) {
1498 nextstate = SSH_CHANNEL_DYNAMIC;
1499 rtype = "dynamic-tcpip";
1501 nextstate = SSH_CHANNEL_OPENING;
1502 rtype = "direct-tcpip";
1506 addrlen = sizeof(addr);
1507 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1509 error("accept: %.100s", strerror(errno));
1512 set_nodelay(newsock);
1513 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1514 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1515 nc->listening_port = c->listening_port;
1516 nc->host_port = c->host_port;
1517 if (c->path != NULL)
1518 nc->path = xstrdup(c->path);
1520 if (nextstate != SSH_CHANNEL_DYNAMIC)
1521 port_open_helper(nc, rtype);
1526 * This is the authentication agent socket listening for connections from
1531 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1535 struct sockaddr_storage addr;
1538 if (FD_ISSET(c->sock, readset)) {
1539 addrlen = sizeof(addr);
1540 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1542 error("accept from auth socket: %.100s", strerror(errno));
1545 nc = channel_new("accepted auth socket",
1546 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1547 c->local_window_max, c->local_maxpacket,
1548 0, "accepted auth socket", 1);
1550 packet_start(SSH2_MSG_CHANNEL_OPEN);
1551 packet_put_cstring("auth-agent@openssh.com");
1552 packet_put_int(nc->self);
1553 packet_put_int(c->local_window_max);
1554 packet_put_int(c->local_maxpacket);
1556 packet_start(SSH_SMSG_AGENT_OPEN);
1557 packet_put_int(nc->self);
1565 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1568 socklen_t sz = sizeof(err);
1570 if (FD_ISSET(c->sock, writeset)) {
1571 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1573 error("getsockopt SO_ERROR failed");
1576 debug("channel %d: connected to %s port %d",
1577 c->self, c->connect_ctx.host, c->connect_ctx.port);
1578 channel_connect_ctx_free(&c->connect_ctx);
1579 c->type = SSH_CHANNEL_OPEN;
1581 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1582 packet_put_int(c->remote_id);
1583 packet_put_int(c->self);
1584 packet_put_int(c->local_window);
1585 packet_put_int(c->local_maxpacket);
1587 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1588 packet_put_int(c->remote_id);
1589 packet_put_int(c->self);
1592 debug("channel %d: connection failed: %s",
1593 c->self, strerror(err));
1594 /* Try next address, if any */
1595 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1597 c->sock = c->rfd = c->wfd = sock;
1598 channel_max_fd = channel_find_maxfd();
1601 /* Exhausted all addresses */
1602 error("connect_to %.100s port %d: failed.",
1603 c->connect_ctx.host, c->connect_ctx.port);
1604 channel_connect_ctx_free(&c->connect_ctx);
1606 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1607 packet_put_int(c->remote_id);
1608 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1609 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1610 packet_put_cstring(strerror(err));
1611 packet_put_cstring("");
1614 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1615 packet_put_int(c->remote_id);
1625 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1627 char buf[CHAN_RBUF];
1630 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1631 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1633 len = read(c->rfd, buf, sizeof(buf));
1634 if (len < 0 && (errno == EINTR ||
1635 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1637 #ifndef PTY_ZEROREAD
1640 if ((!c->isatty && len <= 0) ||
1641 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1643 debug2("channel %d: read<=0 rfd %d len %d",
1644 c->self, c->rfd, len);
1645 if (c->type != SSH_CHANNEL_OPEN) {
1646 debug2("channel %d: not open", c->self);
1649 } else if (compat13) {
1650 buffer_clear(&c->output);
1651 c->type = SSH_CHANNEL_INPUT_DRAINING;
1652 debug2("channel %d: input draining.", c->self);
1654 chan_read_failed(c);
1658 if (c->input_filter != NULL) {
1659 if (c->input_filter(c, buf, len) == -1) {
1660 debug2("channel %d: filter stops", c->self);
1661 chan_read_failed(c);
1663 } else if (c->datagram) {
1664 buffer_put_string(&c->input, buf, len);
1666 buffer_append(&c->input, buf, len);
1674 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1677 u_char *data = NULL, *buf;
1678 u_int dlen, olen = 0;
1681 /* Send buffered output data to the socket. */
1683 FD_ISSET(c->wfd, writeset) &&
1684 buffer_len(&c->output) > 0) {
1685 olen = buffer_len(&c->output);
1686 if (c->output_filter != NULL) {
1687 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1688 debug2("channel %d: filter stops", c->self);
1689 if (c->type != SSH_CHANNEL_OPEN)
1692 chan_write_failed(c);
1695 } else if (c->datagram) {
1696 buf = data = buffer_get_string(&c->output, &dlen);
1698 buf = data = buffer_ptr(&c->output);
1699 dlen = buffer_len(&c->output);
1703 /* ignore truncated writes, datagrams might get lost */
1704 len = write(c->wfd, buf, dlen);
1706 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1707 errno == EWOULDBLOCK))
1710 if (c->type != SSH_CHANNEL_OPEN)
1713 chan_write_failed(c);
1719 /* XXX: Later AIX versions can't push as much data to tty */
1720 if (compat20 && c->wfd_isatty)
1721 dlen = MIN(dlen, 8*1024);
1724 len = write(c->wfd, buf, dlen);
1726 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1729 if (c->type != SSH_CHANNEL_OPEN) {
1730 debug2("channel %d: not open", c->self);
1733 } else if (compat13) {
1734 buffer_clear(&c->output);
1735 debug2("channel %d: input draining.", c->self);
1736 c->type = SSH_CHANNEL_INPUT_DRAINING;
1738 chan_write_failed(c);
1742 #ifndef BROKEN_TCGETATTR_ICANON
1743 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1744 if (tcgetattr(c->wfd, &tio) == 0 &&
1745 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1747 * Simulate echo to reduce the impact of
1748 * traffic analysis. We need to match the
1749 * size of a SSH2_MSG_CHANNEL_DATA message
1750 * (4 byte channel id + buf)
1752 packet_send_ignore(4 + len);
1757 buffer_consume(&c->output, len);
1760 if (compat20 && olen > 0)
1761 c->local_consumed += olen - buffer_len(&c->output);
1766 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1768 char buf[CHAN_RBUF];
1771 /** XXX handle drain efd, too */
1773 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1774 FD_ISSET(c->efd, writeset) &&
1775 buffer_len(&c->extended) > 0) {
1776 len = write(c->efd, buffer_ptr(&c->extended),
1777 buffer_len(&c->extended));
1778 debug2("channel %d: written %d to efd %d",
1779 c->self, len, c->efd);
1780 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1781 errno == EWOULDBLOCK))
1784 debug2("channel %d: closing write-efd %d",
1786 channel_close_fd(&c->efd);
1788 buffer_consume(&c->extended, len);
1789 c->local_consumed += len;
1791 } else if (c->efd != -1 &&
1792 (c->extended_usage == CHAN_EXTENDED_READ ||
1793 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1794 (c->detach_close || FD_ISSET(c->efd, readset))) {
1795 len = read(c->efd, buf, sizeof(buf));
1796 debug2("channel %d: read %d from efd %d",
1797 c->self, len, c->efd);
1798 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1799 errno == EWOULDBLOCK) && !c->detach_close)))
1802 debug2("channel %d: closing read-efd %d",
1804 channel_close_fd(&c->efd);
1806 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1807 debug3("channel %d: discard efd",
1810 buffer_append(&c->extended, buf, len);
1818 channel_check_window(Channel *c)
1820 if (c->type == SSH_CHANNEL_OPEN &&
1821 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1822 ((c->local_window_max - c->local_window >
1823 c->local_maxpacket*3) ||
1824 c->local_window < c->local_window_max/2) &&
1825 c->local_consumed > 0) {
1827 /* adjust max window size if we are in a dynamic environment */
1828 if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
1829 /* grow the window somewhat aggressively to maintain pressure */
1830 addition = 1.5*(c->tcpwinsz - c->local_window_max);
1831 c->local_window_max += addition;
1833 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1834 packet_put_int(c->remote_id);
1835 packet_put_int(c->local_consumed + addition);
1837 debug2("channel %d: window %d sent adjust %d",
1838 c->self, c->local_window,
1840 c->local_window += c->local_consumed + addition;
1841 c->local_consumed = 0;
1847 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1849 channel_handle_rfd(c, readset, writeset);
1850 channel_handle_wfd(c, readset, writeset);
1853 channel_handle_efd(c, readset, writeset);
1854 channel_check_window(c);
1858 read_mux(Channel *c, u_int need)
1860 char buf[CHAN_RBUF];
1864 if (buffer_len(&c->input) < need) {
1865 rlen = need - buffer_len(&c->input);
1866 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1868 if (errno != EINTR && errno != EAGAIN) {
1869 debug2("channel %d: ctl read<=0 rfd %d len %d",
1870 c->self, c->rfd, len);
1871 chan_read_failed(c);
1875 buffer_append(&c->input, buf, len);
1877 return buffer_len(&c->input);
1881 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1887 fatal("%s: entered with !compat20", __func__);
1889 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1890 (c->istate == CHAN_INPUT_OPEN ||
1891 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1893 * Don't not read past the precise end of packets to
1894 * avoid disrupting fd passing.
1896 if (read_mux(c, 4) < 4) /* read header */
1898 need = get_u32(buffer_ptr(&c->input));
1899 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1900 if (need > CHANNEL_MUX_MAX_PACKET) {
1901 debug2("channel %d: packet too big %u > %u",
1902 c->self, CHANNEL_MUX_MAX_PACKET, need);
1903 chan_rcvd_oclose(c);
1906 if (read_mux(c, need + 4) < need + 4) /* read body */
1908 if (c->mux_rcb(c) != 0) {
1909 debug("channel %d: mux_rcb failed", c->self);
1915 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1916 buffer_len(&c->output) > 0) {
1917 len = write(c->wfd, buffer_ptr(&c->output),
1918 buffer_len(&c->output));
1919 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1925 buffer_consume(&c->output, len);
1930 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1933 struct sockaddr_storage addr;
1939 if (!FD_ISSET(c->sock, readset))
1942 debug("multiplexing control connection");
1945 * Accept connection on control socket
1947 memset(&addr, 0, sizeof(addr));
1948 addrlen = sizeof(addr);
1949 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1951 error("%s accept: %s", __func__, strerror(errno));
1955 if (getpeereid(newsock, &euid, &egid) < 0) {
1956 error("%s getpeereid failed: %s", __func__,
1961 if ((euid != 0) && (getuid() != euid)) {
1962 error("multiplex uid mismatch: peer euid %u != uid %u",
1963 (u_int)euid, (u_int)getuid());
1967 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1968 newsock, newsock, -1, c->local_window_max,
1969 c->local_maxpacket, 0, "mux-control", 1);
1970 nc->mux_rcb = c->mux_rcb;
1971 debug3("%s: new mux channel %d fd %d", __func__,
1972 nc->self, nc->sock);
1973 /* establish state */
1975 /* mux state transitions must not elicit protocol messages */
1976 nc->flags |= CHAN_LOCAL;
1981 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1985 /* Send buffered output data to the socket. */
1986 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1987 len = write(c->sock, buffer_ptr(&c->output),
1988 buffer_len(&c->output));
1990 buffer_clear(&c->output);
1992 buffer_consume(&c->output, len);
1997 channel_handler_init_20(void)
1999 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2000 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2001 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2002 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2003 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2004 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2005 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2006 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2007 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2008 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2010 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2011 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2012 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2013 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2014 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2015 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2016 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2017 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2018 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2022 channel_handler_init_13(void)
2024 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2025 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
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_INPUT_DRAINING] = &channel_pre_input_draining;
2030 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2031 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2032 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2034 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2035 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2036 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2037 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2038 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2039 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2040 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2044 channel_handler_init_15(void)
2046 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2047 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2048 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2049 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2050 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2051 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2052 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2054 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2055 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2056 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2057 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2058 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2059 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2063 channel_handler_init(void)
2067 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2068 channel_pre[i] = NULL;
2069 channel_post[i] = NULL;
2072 channel_handler_init_20();
2074 channel_handler_init_13();
2076 channel_handler_init_15();
2079 /* gc dead channels */
2081 channel_garbage_collect(Channel *c)
2085 if (c->detach_user != NULL) {
2086 if (!chan_is_dead(c, c->detach_close))
2088 debug2("channel %d: gc: notify user", c->self);
2089 c->detach_user(c->self, NULL);
2090 /* if we still have a callback */
2091 if (c->detach_user != NULL)
2093 debug2("channel %d: gc: user detached", c->self);
2095 if (!chan_is_dead(c, 1))
2097 debug2("channel %d: garbage collecting", c->self);
2102 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
2104 static int did_init = 0;
2109 channel_handler_init();
2112 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2117 if (ftab == channel_pre)
2122 if (ftab[c->type] != NULL)
2123 (*ftab[c->type])(c, readset, writeset);
2124 channel_garbage_collect(c);
2129 * Allocate/update select bitmasks and add any bits relevant to channels in
2133 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2134 u_int *nallocp, int rekeying)
2136 u_int n, sz, nfdset;
2138 n = MAX(*maxfdp, channel_max_fd);
2140 nfdset = howmany(n+1, NFDBITS);
2141 /* Explicitly test here, because xrealloc isn't always called */
2142 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2143 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2144 sz = nfdset * sizeof(fd_mask);
2146 /* perhaps check sz < nalloc/2 and shrink? */
2147 if (*readsetp == NULL || sz > *nallocp) {
2148 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2149 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2153 memset(*readsetp, 0, sz);
2154 memset(*writesetp, 0, sz);
2157 channel_handler(channel_pre, *readsetp, *writesetp);
2161 * After select, perform any appropriate operations for channels which have
2165 channel_after_select(fd_set *readset, fd_set *writeset)
2167 channel_handler(channel_post, readset, writeset);
2171 /* If there is data to send to the connection, enqueue some of it now. */
2173 channel_output_poll(void)
2177 int packet_length = 0;
2179 for (i = 0; i < channels_alloc; i++) {
2185 * We are only interested in channels that can have buffered
2189 if (c->type != SSH_CHANNEL_OPEN &&
2190 c->type != SSH_CHANNEL_INPUT_DRAINING)
2193 if (c->type != SSH_CHANNEL_OPEN)
2197 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2198 /* XXX is this true? */
2199 debug3("channel %d: will not send data after close", c->self);
2203 /* Get the amount of buffered data for this channel. */
2204 if ((c->istate == CHAN_INPUT_OPEN ||
2205 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2206 (len = buffer_len(&c->input)) > 0) {
2212 data = buffer_get_string(&c->input,
2214 if (dlen > c->remote_window ||
2215 dlen > c->remote_maxpacket) {
2216 debug("channel %d: datagram "
2217 "too big for channel",
2222 packet_start(SSH2_MSG_CHANNEL_DATA);
2223 packet_put_int(c->remote_id);
2224 packet_put_string(data, dlen);
2225 packet_length = packet_send();
2226 c->remote_window -= dlen + 4;
2232 * Send some data for the other side over the secure
2236 if (len > c->remote_window)
2237 len = c->remote_window;
2238 if (len > c->remote_maxpacket)
2239 len = c->remote_maxpacket;
2241 if (packet_is_interactive()) {
2245 /* Keep the packets at reasonable size. */
2246 if (len > packet_get_maxsize()/2)
2247 len = packet_get_maxsize()/2;
2251 packet_start(compat20 ?
2252 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2253 packet_put_int(c->remote_id);
2254 packet_put_string(buffer_ptr(&c->input), len);
2255 packet_length = packet_send();
2256 buffer_consume(&c->input, len);
2257 c->remote_window -= len;
2259 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2261 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2263 * input-buffer is empty and read-socket shutdown:
2264 * tell peer, that we will not send more data: send IEOF.
2265 * hack for extended data: delay EOF if EFD still in use.
2267 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2268 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2269 c->self, c->efd, buffer_len(&c->extended));
2273 /* Send extended data, i.e. stderr */
2275 !(c->flags & CHAN_EOF_SENT) &&
2276 c->remote_window > 0 &&
2277 (len = buffer_len(&c->extended)) > 0 &&
2278 c->extended_usage == CHAN_EXTENDED_READ) {
2279 debug2("channel %d: rwin %u elen %u euse %d",
2280 c->self, c->remote_window, buffer_len(&c->extended),
2282 if (len > c->remote_window)
2283 len = c->remote_window;
2284 if (len > c->remote_maxpacket)
2285 len = c->remote_maxpacket;
2286 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2287 packet_put_int(c->remote_id);
2288 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2289 packet_put_string(buffer_ptr(&c->extended), len);
2290 packet_length = packet_send();
2291 buffer_consume(&c->extended, len);
2292 c->remote_window -= len;
2293 debug2("channel %d: sent ext data %d", c->self, len);
2296 return (packet_length);
2300 /* -- protocol input */
2304 channel_input_data(int type, u_int32_t seq, void *ctxt)
2308 u_int data_len, win_len;
2311 /* Get the channel number and verify it. */
2312 id = packet_get_int();
2313 c = channel_lookup(id);
2315 packet_disconnect("Received data for nonexistent channel %d.", id);
2317 /* Ignore any data for non-open channels (might happen on close) */
2318 if (c->type != SSH_CHANNEL_OPEN &&
2319 c->type != SSH_CHANNEL_X11_OPEN)
2323 data = packet_get_string_ptr(&data_len);
2326 win_len += 4; /* string length header */
2329 * Ignore data for protocol > 1.3 if output end is no longer open.
2330 * For protocol 2 the sending side is reducing its window as it sends
2331 * data, so we must 'fake' consumption of the data in order to ensure
2332 * that window updates are sent back. Otherwise the connection might
2335 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2337 c->local_window -= win_len;
2338 c->local_consumed += win_len;
2344 if (win_len > c->local_maxpacket) {
2345 logit("channel %d: rcvd big packet %d, maxpack %d",
2346 c->self, win_len, c->local_maxpacket);
2348 if (win_len > c->local_window) {
2349 logit("channel %d: rcvd too much data %d, win %d",
2350 c->self, win_len, c->local_window);
2353 c->local_window -= win_len;
2356 buffer_put_string(&c->output, data, data_len);
2358 buffer_append(&c->output, data, data_len);
2364 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2368 u_int data_len, tcode;
2371 /* Get the channel number and verify it. */
2372 id = packet_get_int();
2373 c = channel_lookup(id);
2376 packet_disconnect("Received extended_data for bad channel %d.", id);
2377 if (c->type != SSH_CHANNEL_OPEN) {
2378 logit("channel %d: ext data for non open", id);
2381 if (c->flags & CHAN_EOF_RCVD) {
2382 if (datafellows & SSH_BUG_EXTEOF)
2383 debug("channel %d: accepting ext data after eof", id);
2385 packet_disconnect("Received extended_data after EOF "
2386 "on channel %d.", id);
2388 tcode = packet_get_int();
2390 c->extended_usage != CHAN_EXTENDED_WRITE ||
2391 tcode != SSH2_EXTENDED_DATA_STDERR) {
2392 logit("channel %d: bad ext data", c->self);
2395 data = packet_get_string(&data_len);
2397 if (data_len > c->local_window) {
2398 logit("channel %d: rcvd too much extended_data %d, win %d",
2399 c->self, data_len, c->local_window);
2403 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2404 c->local_window -= data_len;
2405 buffer_append(&c->extended, data, data_len);
2411 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2416 id = packet_get_int();
2418 c = channel_lookup(id);
2420 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2423 /* XXX force input close */
2424 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2425 debug("channel %d: FORCE input drain", c->self);
2426 c->istate = CHAN_INPUT_WAIT_DRAIN;
2427 if (buffer_len(&c->input) == 0)
2435 channel_input_close(int type, u_int32_t seq, void *ctxt)
2440 id = packet_get_int();
2442 c = channel_lookup(id);
2444 packet_disconnect("Received close for nonexistent channel %d.", id);
2447 * Send a confirmation that we have closed the channel and no more
2448 * data is coming for it.
2450 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2451 packet_put_int(c->remote_id);
2455 * If the channel is in closed state, we have sent a close request,
2456 * and the other side will eventually respond with a confirmation.
2457 * Thus, we cannot free the channel here, because then there would be
2458 * no-one to receive the confirmation. The channel gets freed when
2459 * the confirmation arrives.
2461 if (c->type != SSH_CHANNEL_CLOSED) {
2463 * Not a closed channel - mark it as draining, which will
2464 * cause it to be freed later.
2466 buffer_clear(&c->input);
2467 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2471 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2474 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2476 int id = packet_get_int();
2477 Channel *c = channel_lookup(id);
2481 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2482 chan_rcvd_oclose(c);
2487 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2489 int id = packet_get_int();
2490 Channel *c = channel_lookup(id);
2494 packet_disconnect("Received close confirmation for "
2495 "out-of-range channel %d.", id);
2496 if (c->type != SSH_CHANNEL_CLOSED)
2497 packet_disconnect("Received close confirmation for "
2498 "non-closed channel %d (type %d).", id, c->type);
2504 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2509 id = packet_get_int();
2510 c = channel_lookup(id);
2512 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2513 packet_disconnect("Received open confirmation for "
2514 "non-opening channel %d.", id);
2515 remote_id = packet_get_int();
2516 /* Record the remote channel number and mark that the channel is now open. */
2517 c->remote_id = remote_id;
2518 c->type = SSH_CHANNEL_OPEN;
2521 c->remote_window = packet_get_int();
2522 c->remote_maxpacket = packet_get_int();
2523 if (c->open_confirm) {
2524 debug2("callback start");
2525 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2526 debug2("callback done");
2528 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2529 c->remote_window, c->remote_maxpacket);
2535 reason2txt(int reason)
2538 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2539 return "administratively prohibited";
2540 case SSH2_OPEN_CONNECT_FAILED:
2541 return "connect failed";
2542 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2543 return "unknown channel type";
2544 case SSH2_OPEN_RESOURCE_SHORTAGE:
2545 return "resource shortage";
2547 return "unknown reason";
2552 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2555 char *msg = NULL, *lang = NULL;
2558 id = packet_get_int();
2559 c = channel_lookup(id);
2561 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2562 packet_disconnect("Received open failure for "
2563 "non-opening channel %d.", id);
2565 reason = packet_get_int();
2566 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2567 msg = packet_get_string(NULL);
2568 lang = packet_get_string(NULL);
2570 logit("channel %d: open failed: %s%s%s", id,
2571 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2576 if (c->open_confirm) {
2577 debug2("callback start");
2578 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2579 debug2("callback done");
2583 /* Schedule the channel for cleanup/deletion. */
2589 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2598 /* Get the channel number and verify it. */
2599 id = packet_get_int();
2600 c = channel_lookup(id);
2603 logit("Received window adjust for non-open channel %d.", id);
2606 adjust = packet_get_int();
2608 debug2("channel %d: rcvd adjust %u", id, adjust);
2609 c->remote_window += adjust;
2614 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2618 char *host, *originator_string;
2621 remote_id = packet_get_int();
2622 host = packet_get_string(NULL);
2623 host_port = packet_get_int();
2625 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2626 originator_string = packet_get_string(NULL);
2628 originator_string = xstrdup("unknown (remote did not supply name)");
2631 c = channel_connect_to(host, host_port,
2632 "connected socket", originator_string);
2633 xfree(originator_string);
2636 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2637 packet_put_int(remote_id);
2640 c->remote_id = remote_id;
2645 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2648 struct channel_confirm *cc;
2651 /* Reset keepalive timeout */
2652 packet_set_alive_timeouts(0);
2654 id = packet_get_int();
2657 debug2("channel_input_status_confirm: type %d id %d", type, id);
2659 if ((c = channel_lookup(id)) == NULL) {
2660 logit("channel_input_status_confirm: %d: unknown", id);
2664 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2666 cc->cb(type, c, cc->ctx);
2667 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2668 bzero(cc, sizeof(*cc));
2672 /* -- tcp forwarding */
2675 channel_set_af(int af)
2682 channel_set_hpn(int external_hpn_disabled, int external_hpn_buffer_size)
2684 hpn_disabled = external_hpn_disabled;
2685 hpn_buffer_size = external_hpn_buffer_size;
2686 debug("HPN Disabled: %d, HPN Buffer Size: %d", hpn_disabled, hpn_buffer_size);
2690 channel_setup_fwd_listener(int type, const char *listen_addr,
2691 u_short listen_port, int *allocated_listen_port,
2692 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2695 int sock, r, success = 0, wildcard = 0, is_client;
2696 struct addrinfo hints, *ai, *aitop;
2697 const char *host, *addr;
2698 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2701 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2702 listen_addr : host_to_connect;
2703 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2706 error("No forward host name.");
2709 if (strlen(host) >= NI_MAXHOST) {
2710 error("Forward host name too long.");
2715 * Determine whether or not a port forward listens to loopback,
2716 * specified address or wildcard. On the client, a specified bind
2717 * address will always override gateway_ports. On the server, a
2718 * gateway_ports of 1 (``yes'') will override the client's
2719 * specification and force a wildcard bind, whereas a value of 2
2720 * (``clientspecified'') will bind to whatever address the client
2723 * Special-case listen_addrs are:
2725 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2726 * "" (empty string), "*" -> wildcard v4/v6
2727 * "localhost" -> loopback v4/v6
2730 if (listen_addr == NULL) {
2731 /* No address specified: default to gateway_ports setting */
2734 } else if (gateway_ports || is_client) {
2735 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2736 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2737 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2738 (!is_client && gateway_ports == 1))
2740 else if (strcmp(listen_addr, "localhost") != 0)
2744 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2745 type, wildcard, (addr == NULL) ? "NULL" : addr);
2748 * getaddrinfo returns a loopback address if the hostname is
2749 * set to NULL and hints.ai_flags is not AI_PASSIVE
2751 memset(&hints, 0, sizeof(hints));
2752 hints.ai_family = IPv4or6;
2753 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2754 hints.ai_socktype = SOCK_STREAM;
2755 snprintf(strport, sizeof strport, "%d", listen_port);
2756 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2758 /* This really shouldn't happen */
2759 packet_disconnect("getaddrinfo: fatal error: %s",
2760 ssh_gai_strerror(r));
2762 error("channel_setup_fwd_listener: "
2763 "getaddrinfo(%.64s): %s", addr,
2764 ssh_gai_strerror(r));
2768 if (allocated_listen_port != NULL)
2769 *allocated_listen_port = 0;
2770 for (ai = aitop; ai; ai = ai->ai_next) {
2771 switch (ai->ai_family) {
2773 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2777 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2784 * If allocating a port for -R forwards, then use the
2785 * same port for all address families.
2787 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2788 allocated_listen_port != NULL && *allocated_listen_port > 0)
2789 *lport_p = htons(*allocated_listen_port);
2791 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2792 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2793 error("channel_setup_fwd_listener: getnameinfo failed");
2796 /* Create a port to listen for the host. */
2797 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2799 /* this is no error since kernel may not support ipv6 */
2800 verbose("socket: %.100s", strerror(errno));
2804 channel_set_reuseaddr(sock);
2805 if (ai->ai_family == AF_INET6)
2806 sock_set_v6only(sock);
2808 debug("Local forwarding listening on %s port %s.",
2811 /* Bind the socket to the address. */
2812 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2813 /* address can be in use ipv6 address is already bound */
2815 error("bind: %.100s", strerror(errno));
2817 verbose("bind: %.100s", strerror(errno));
2822 /* Start listening for connections on the socket. */
2823 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2824 error("listen: %.100s", strerror(errno));
2830 * listen_port == 0 requests a dynamically allocated port -
2831 * record what we got.
2833 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2834 allocated_listen_port != NULL &&
2835 *allocated_listen_port == 0) {
2836 *allocated_listen_port = get_sock_port(sock, 1);
2837 debug("Allocated listen port %d",
2838 *allocated_listen_port);
2841 /* Allocate a channel number for the socket. */
2842 /* explicitly test for hpn disabled option. if true use smaller window size */
2844 c = channel_new("port listener", type, sock, sock, -1,
2845 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2846 0, "port listener", 1);
2848 c = channel_new("port listener", type, sock, sock, -1,
2849 hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
2850 0, "port listener", 1);
2851 c->path = xstrdup(host);
2852 c->host_port = port_to_connect;
2853 c->listening_port = listen_port;
2857 error("channel_setup_fwd_listener: cannot listen to port: %d",
2859 freeaddrinfo(aitop);
2864 channel_cancel_rport_listener(const char *host, u_short port)
2869 for (i = 0; i < channels_alloc; i++) {
2870 Channel *c = channels[i];
2872 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2873 strcmp(c->path, host) == 0 && c->listening_port == port) {
2874 debug2("%s: close channel %d", __func__, i);
2883 /* protocol local port fwd, used by ssh (and sshd in v1) */
2885 channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2886 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2888 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2889 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2893 /* protocol v2 remote port fwd, used by sshd */
2895 channel_setup_remote_fwd_listener(const char *listen_address,
2896 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2898 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2899 listen_address, listen_port, allocated_listen_port,
2900 NULL, 0, gateway_ports);
2904 * Initiate forwarding of connections to port "port" on remote host through
2905 * the secure channel to host:port from local side.
2909 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2910 const char *host_to_connect, u_short port_to_connect)
2912 int type, success = 0;
2914 /* Send the forward request to the remote side. */
2916 const char *address_to_bind;
2917 if (listen_host == NULL) {
2918 if (datafellows & SSH_BUG_RFWD_ADDR)
2919 address_to_bind = "127.0.0.1";
2921 address_to_bind = "localhost";
2922 } else if (*listen_host == '\0' ||
2923 strcmp(listen_host, "*") == 0) {
2924 if (datafellows & SSH_BUG_RFWD_ADDR)
2925 address_to_bind = "0.0.0.0";
2927 address_to_bind = "";
2929 address_to_bind = listen_host;
2931 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2932 packet_put_cstring("tcpip-forward");
2933 packet_put_char(1); /* boolean: want reply */
2934 packet_put_cstring(address_to_bind);
2935 packet_put_int(listen_port);
2937 packet_write_wait();
2938 /* Assume that server accepts the request */
2941 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2942 packet_put_int(listen_port);
2943 packet_put_cstring(host_to_connect);
2944 packet_put_int(port_to_connect);
2946 packet_write_wait();
2948 /* Wait for response from the remote side. */
2949 type = packet_read();
2951 case SSH_SMSG_SUCCESS:
2954 case SSH_SMSG_FAILURE:
2957 /* Unknown packet */
2958 packet_disconnect("Protocol error for port forward request:"
2959 "received packet type %d.", type);
2963 /* Record that connection to this host/port is permitted. */
2964 permitted_opens = xrealloc(permitted_opens,
2965 num_permitted_opens + 1, sizeof(*permitted_opens));
2966 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2967 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2968 permitted_opens[num_permitted_opens].listen_port = listen_port;
2969 num_permitted_opens++;
2971 return (success ? 0 : -1);
2975 * Request cancellation of remote forwarding of connection host:port from
2979 channel_request_rforward_cancel(const char *host, u_short port)
2986 for (i = 0; i < num_permitted_opens; i++) {
2987 if (permitted_opens[i].host_to_connect != NULL &&
2988 permitted_opens[i].listen_port == port)
2991 if (i >= num_permitted_opens) {
2992 debug("%s: requested forward not found", __func__);
2995 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2996 packet_put_cstring("cancel-tcpip-forward");
2998 packet_put_cstring(host == NULL ? "" : host);
2999 packet_put_int(port);
3002 permitted_opens[i].listen_port = 0;
3003 permitted_opens[i].port_to_connect = 0;
3004 xfree(permitted_opens[i].host_to_connect);
3005 permitted_opens[i].host_to_connect = NULL;
3009 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3010 * listening for the port, and sends back a success reply (or disconnect
3011 * message if there was an error).
3014 channel_input_port_forward_request(int is_root, int gateway_ports)
3016 u_short port, host_port;
3020 /* Get arguments from the packet. */
3021 port = packet_get_int();
3022 hostname = packet_get_string(NULL);
3023 host_port = packet_get_int();
3027 * Check that an unprivileged user is not trying to forward a
3030 if (port < IPPORT_RESERVED && !is_root)
3032 "Requested forwarding of port %d but user is not root.",
3035 packet_disconnect("Dynamic forwarding denied.");
3038 /* Initiate forwarding */
3039 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3040 host_port, gateway_ports);
3042 /* Free the argument string. */
3045 return (success ? 0 : -1);
3049 * Permits opening to any host/port if permitted_opens[] is empty. This is
3050 * usually called by the server, because the user could connect to any port
3051 * anyway, and the server has no way to know but to trust the client anyway.
3054 channel_permit_all_opens(void)
3056 if (num_permitted_opens == 0)
3057 all_opens_permitted = 1;
3061 channel_add_permitted_opens(char *host, int port)
3063 debug("allow port forwarding to host %s port %d", host, port);
3065 permitted_opens = xrealloc(permitted_opens,
3066 num_permitted_opens + 1, sizeof(*permitted_opens));
3067 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3068 permitted_opens[num_permitted_opens].port_to_connect = port;
3069 num_permitted_opens++;
3071 all_opens_permitted = 0;
3075 channel_add_adm_permitted_opens(char *host, int port)
3077 debug("config allows port forwarding to host %s port %d", host, port);
3079 permitted_adm_opens = xrealloc(permitted_adm_opens,
3080 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3081 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3083 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3084 return ++num_adm_permitted_opens;
3088 channel_clear_permitted_opens(void)
3092 for (i = 0; i < num_permitted_opens; i++)
3093 if (permitted_opens[i].host_to_connect != NULL)
3094 xfree(permitted_opens[i].host_to_connect);
3095 if (num_permitted_opens > 0) {
3096 xfree(permitted_opens);
3097 permitted_opens = NULL;
3099 num_permitted_opens = 0;
3103 channel_clear_adm_permitted_opens(void)
3107 for (i = 0; i < num_adm_permitted_opens; i++)
3108 if (permitted_adm_opens[i].host_to_connect != NULL)
3109 xfree(permitted_adm_opens[i].host_to_connect);
3110 if (num_adm_permitted_opens > 0) {
3111 xfree(permitted_adm_opens);
3112 permitted_adm_opens = NULL;
3114 num_adm_permitted_opens = 0;
3118 channel_print_adm_permitted_opens(void)
3122 printf("permitopen");
3123 if (num_adm_permitted_opens == 0) {
3127 for (i = 0; i < num_adm_permitted_opens; i++)
3128 if (permitted_adm_opens[i].host_to_connect != NULL)
3129 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3130 permitted_adm_opens[i].port_to_connect);
3134 /* Try to start non-blocking connect to next host in cctx list */
3136 connect_next(struct channel_connect *cctx)
3138 int sock, saved_errno;
3139 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3141 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3142 if (cctx->ai->ai_family != AF_INET &&
3143 cctx->ai->ai_family != AF_INET6)
3145 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3146 ntop, sizeof(ntop), strport, sizeof(strport),
3147 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3148 error("connect_next: getnameinfo failed");
3151 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3152 cctx->ai->ai_protocol)) == -1) {
3153 if (cctx->ai->ai_next == NULL)
3154 error("socket: %.100s", strerror(errno));
3156 verbose("socket: %.100s", strerror(errno));
3159 if (set_nonblock(sock) == -1)
3160 fatal("%s: set_nonblock(%d)", __func__, sock);
3161 if (connect(sock, cctx->ai->ai_addr,
3162 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3163 debug("connect_next: host %.100s ([%.100s]:%s): "
3164 "%.100s", cctx->host, ntop, strport,
3166 saved_errno = errno;
3168 errno = saved_errno;
3169 continue; /* fail -- try next */
3171 debug("connect_next: host %.100s ([%.100s]:%s) "
3172 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3173 cctx->ai = cctx->ai->ai_next;
3181 channel_connect_ctx_free(struct channel_connect *cctx)
3185 freeaddrinfo(cctx->aitop);
3186 bzero(cctx, sizeof(*cctx));
3188 cctx->ai = cctx->aitop = NULL;
3191 /* Return CONNECTING channel to remote host, port */
3193 connect_to(const char *host, u_short port, char *ctype, char *rname)
3195 struct addrinfo hints;
3198 char strport[NI_MAXSERV];
3199 struct channel_connect cctx;
3202 memset(&cctx, 0, sizeof(cctx));
3203 memset(&hints, 0, sizeof(hints));
3204 hints.ai_family = IPv4or6;
3205 hints.ai_socktype = SOCK_STREAM;
3206 snprintf(strport, sizeof strport, "%d", port);
3207 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3208 error("connect_to %.100s: unknown host (%s)", host,
3209 ssh_gai_strerror(gaierr));
3213 cctx.host = xstrdup(host);
3215 cctx.ai = cctx.aitop;
3217 if ((sock = connect_next(&cctx)) == -1) {
3218 error("connect to %.100s port %d failed: %s",
3219 host, port, strerror(errno));
3220 channel_connect_ctx_free(&cctx);
3223 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3224 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3225 c->connect_ctx = cctx;
3230 channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3234 for (i = 0; i < num_permitted_opens; i++) {
3235 if (permitted_opens[i].host_to_connect != NULL &&
3236 permitted_opens[i].listen_port == listen_port) {
3238 permitted_opens[i].host_to_connect,
3239 permitted_opens[i].port_to_connect, ctype, rname);
3242 error("WARNING: Server requests forwarding for unknown listen_port %d",
3247 /* Check if connecting to that port is permitted and connect. */
3249 channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3251 int i, permit, permit_adm = 1;
3253 permit = all_opens_permitted;
3255 for (i = 0; i < num_permitted_opens; i++)
3256 if (permitted_opens[i].host_to_connect != NULL &&
3257 permitted_opens[i].port_to_connect == port &&
3258 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3262 if (num_adm_permitted_opens > 0) {
3264 for (i = 0; i < num_adm_permitted_opens; i++)
3265 if (permitted_adm_opens[i].host_to_connect != NULL &&
3266 permitted_adm_opens[i].port_to_connect == port &&
3267 strcmp(permitted_adm_opens[i].host_to_connect, host)
3272 if (!permit || !permit_adm) {
3273 logit("Received request to connect to host %.100s port %d, "
3274 "but the request was denied.", host, port);
3277 return connect_to(host, port, ctype, rname);
3281 channel_send_window_changes(void)
3286 for (i = 0; i < channels_alloc; i++) {
3287 if (channels[i] == NULL || !channels[i]->client_tty ||
3288 channels[i]->type != SSH_CHANNEL_OPEN)
3290 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3292 channel_request_start(i, "window-change", 0);
3293 packet_put_int((u_int)ws.ws_col);
3294 packet_put_int((u_int)ws.ws_row);
3295 packet_put_int((u_int)ws.ws_xpixel);
3296 packet_put_int((u_int)ws.ws_ypixel);
3301 /* -- X11 forwarding */
3304 * Creates an internet domain socket for listening for X11 connections.
3305 * Returns 0 and a suitable display number for the DISPLAY variable
3306 * stored in display_numberp , or -1 if an error occurs.
3309 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3310 int single_connection, u_int *display_numberp, int **chanids)
3313 int display_number, sock;
3315 struct addrinfo hints, *ai, *aitop;
3316 char strport[NI_MAXSERV];
3317 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3319 if (chanids == NULL)
3322 for (display_number = x11_display_offset;
3323 display_number < MAX_DISPLAYS;
3325 port = 6000 + display_number;
3326 memset(&hints, 0, sizeof(hints));
3327 hints.ai_family = IPv4or6;
3328 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3329 hints.ai_socktype = SOCK_STREAM;
3330 snprintf(strport, sizeof strport, "%d", port);
3331 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3332 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3335 for (ai = aitop; ai; ai = ai->ai_next) {
3336 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3338 sock = socket(ai->ai_family, ai->ai_socktype,
3341 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3343 && (errno != EPFNOSUPPORT)
3346 error("socket: %.100s", strerror(errno));
3347 freeaddrinfo(aitop);
3350 debug("x11_create_display_inet: Socket family %d not supported",
3355 if (ai->ai_family == AF_INET6)
3356 sock_set_v6only(sock);
3357 if (x11_use_localhost)
3358 channel_set_reuseaddr(sock);
3359 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3360 debug2("bind port %d: %.100s", port, strerror(errno));
3363 for (n = 0; n < num_socks; n++) {
3369 socks[num_socks++] = sock;
3370 if (num_socks == NUM_SOCKS)
3373 freeaddrinfo(aitop);
3377 if (display_number >= MAX_DISPLAYS) {
3378 error("Failed to allocate internet-domain X11 display socket.");
3381 /* Start listening for connections on the socket. */
3382 for (n = 0; n < num_socks; n++) {
3384 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3385 error("listen: %.100s", strerror(errno));
3391 /* Allocate a channel for each socket. */
3392 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3393 for (n = 0; n < num_socks; n++) {
3395 /* Is this really necassary? */
3397 nc = channel_new("x11 listener",
3398 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3399 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3400 0, "X11 inet listener", 1);
3402 nc = channel_new("x11 listener",
3403 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3404 hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
3405 0, "X11 inet listener", 1);
3406 nc->single_connection = single_connection;
3407 (*chanids)[n] = nc->self;
3411 /* Return the display number for the DISPLAY environment variable. */
3412 *display_numberp = display_number;
3417 connect_local_xsocket_path(const char *pathname)
3420 struct sockaddr_un addr;
3422 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3424 error("socket: %.100s", strerror(errno));
3425 memset(&addr, 0, sizeof(addr));
3426 addr.sun_family = AF_UNIX;
3427 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3428 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3431 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3436 connect_local_xsocket(u_int dnr)
3439 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3440 return connect_local_xsocket_path(buf);
3444 x11_connect_display(void)
3446 u_int display_number;
3447 const char *display;
3448 char buf[1024], *cp;
3449 struct addrinfo hints, *ai, *aitop;
3450 char strport[NI_MAXSERV];
3451 int gaierr, sock = 0;
3453 /* Try to open a socket for the local X server. */
3454 display = getenv("DISPLAY");
3456 error("DISPLAY not set.");
3460 * Now we decode the value of the DISPLAY variable and make a
3461 * connection to the real X server.
3464 /* Check if the display is from launchd. */
3466 if (strncmp(display, "/tmp/launch", 11) == 0) {
3467 sock = connect_local_xsocket_path(display);
3471 /* OK, we now have a connection to the display. */
3476 * Check if it is a unix domain socket. Unix domain displays are in
3477 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3479 if (strncmp(display, "unix:", 5) == 0 ||
3480 display[0] == ':') {
3481 /* Connect to the unix domain socket. */
3482 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3483 error("Could not parse display number from DISPLAY: %.100s",
3487 /* Create a socket. */
3488 sock = connect_local_xsocket(display_number);
3492 /* OK, we now have a connection to the display. */
3496 * Connect to an inet socket. The DISPLAY value is supposedly
3497 * hostname:d[.s], where hostname may also be numeric IP address.
3499 strlcpy(buf, display, sizeof(buf));
3500 cp = strchr(buf, ':');
3502 error("Could not find ':' in DISPLAY: %.100s", display);
3506 /* buf now contains the host name. But first we parse the display number. */
3507 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3508 error("Could not parse display number from DISPLAY: %.100s",
3513 /* Look up the host address */
3514 memset(&hints, 0, sizeof(hints));
3515 hints.ai_family = IPv4or6;
3516 hints.ai_socktype = SOCK_STREAM;
3517 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3518 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3519 error("%.100s: unknown host. (%s)", buf,
3520 ssh_gai_strerror(gaierr));
3523 for (ai = aitop; ai; ai = ai->ai_next) {
3524 /* Create a socket. */
3525 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3527 debug2("socket: %.100s", strerror(errno));
3530 /* Connect it to the display. */
3531 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3532 debug2("connect %.100s port %u: %.100s", buf,
3533 6000 + display_number, strerror(errno));
3540 freeaddrinfo(aitop);
3542 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3551 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3552 * the remote channel number. We should do whatever we want, and respond
3553 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3558 x11_input_open(int type, u_int32_t seq, void *ctxt)
3561 int remote_id, sock = 0;
3564 debug("Received X11 open request.");
3566 remote_id = packet_get_int();
3568 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3569 remote_host = packet_get_string(NULL);
3571 remote_host = xstrdup("unknown (remote did not supply name)");
3575 /* Obtain a connection to the real X display. */
3576 sock = x11_connect_display();
3578 /* Allocate a channel for this connection. */
3579 c = channel_new("connected x11 socket",
3580 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3582 c->remote_id = remote_id;
3587 /* Send refusal to the remote host. */
3588 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3589 packet_put_int(remote_id);
3591 /* Send a confirmation to the remote host. */
3592 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3593 packet_put_int(remote_id);
3594 packet_put_int(c->self);
3599 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3602 deny_input_open(int type, u_int32_t seq, void *ctxt)
3604 int rchan = packet_get_int();
3607 case SSH_SMSG_AGENT_OPEN:
3608 error("Warning: ssh server tried agent forwarding.");
3610 case SSH_SMSG_X11_OPEN:
3611 error("Warning: ssh server tried X11 forwarding.");
3614 error("deny_input_open: type %d", type);
3617 error("Warning: this is probably a break-in attempt by a malicious server.");
3618 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3619 packet_put_int(rchan);
3624 * Requests forwarding of X11 connections, generates fake authentication
3625 * data, and enables authentication spoofing.
3626 * This should be called in the client only.
3629 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3630 const char *proto, const char *data)
3632 u_int data_len = (u_int) strlen(data) / 2;
3639 if (x11_saved_display == NULL)
3640 x11_saved_display = xstrdup(disp);
3641 else if (strcmp(disp, x11_saved_display) != 0) {
3642 error("x11_request_forwarding_with_spoofing: different "
3643 "$DISPLAY already forwarded");
3647 cp = strchr(disp, ':');
3649 cp = strchr(cp, '.');
3651 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3655 if (x11_saved_proto == NULL) {
3656 /* Save protocol name. */
3657 x11_saved_proto = xstrdup(proto);
3659 * Extract real authentication data and generate fake data
3660 * of the same length.
3662 x11_saved_data = xmalloc(data_len);
3663 x11_fake_data = xmalloc(data_len);
3664 for (i = 0; i < data_len; i++) {
3665 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3666 fatal("x11_request_forwarding: bad "
3667 "authentication data: %.100s", data);
3670 x11_saved_data[i] = value;
3671 x11_fake_data[i] = rnd & 0xff;
3674 x11_saved_data_len = data_len;
3675 x11_fake_data_len = data_len;
3678 /* Convert the fake data into hex. */
3679 new_data = tohex(x11_fake_data, data_len);
3681 /* Send the request packet. */
3683 channel_request_start(client_session_id, "x11-req", 0);
3684 packet_put_char(0); /* XXX bool single connection */
3686 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3688 packet_put_cstring(proto);
3689 packet_put_cstring(new_data);
3690 packet_put_int(screen_number);
3692 packet_write_wait();
3697 /* -- agent forwarding */
3699 /* Sends a message to the server to request authentication fd forwarding. */
3702 auth_request_forwarding(void)
3704 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3706 packet_write_wait();