1 /* $OpenBSD: channels.c,v 1.349 2016/02/05 13:28:19 naddy 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/param.h> /* MIN MAX */
47 #include <sys/ioctl.h>
49 #include <sys/socket.h>
50 #ifdef HAVE_SYS_TIME_H
51 # include <sys/time.h>
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
70 #include "openbsd-compat/sys-queue.h"
84 #include "pathnames.h"
89 * Pointer to an array containing all allocated channels. The array is
90 * dynamically extended as needed.
92 static Channel **channels = NULL;
95 * Size of the channel array. All slots of the array must always be
96 * initialized (at least the type field); unused slots set to NULL
98 static u_int channels_alloc = 0;
101 * Maximum file descriptor value used in any of the channels. This is
102 * updated in channel_new.
104 static int channel_max_fd = 0;
107 /* -- tcp forwarding */
110 * Data structure for storing which hosts are permitted for forward requests.
111 * The local sides of any remote forwards are stored in this array to prevent
112 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
113 * network (which might be behind a firewall).
115 /* XXX: streamlocal wants a path instead of host:port */
116 /* Overload host_to_connect; we could just make this match Forward */
117 /* XXX - can we use listen_host instead of listen_path? */
119 char *host_to_connect; /* Connect to 'host'. */
120 int port_to_connect; /* Connect to 'port'. */
121 char *listen_host; /* Remote side should listen address. */
122 char *listen_path; /* Remote side should listen path. */
123 int listen_port; /* Remote side should listen port. */
126 /* List of all permitted host/port pairs to connect by the user. */
127 static ForwardPermission *permitted_opens = NULL;
129 /* List of all permitted host/port pairs to connect by the admin. */
130 static ForwardPermission *permitted_adm_opens = NULL;
132 /* Number of permitted host/port pairs in the array permitted by the user. */
133 static int num_permitted_opens = 0;
135 /* Number of permitted host/port pair in the array permitted by the admin. */
136 static int num_adm_permitted_opens = 0;
138 /* special-case port number meaning allow any port */
139 #define FWD_PERMIT_ANY_PORT 0
142 * If this is true, all opens are permitted. This is the case on the server
143 * on which we have to trust the client anyway, and the user could do
144 * anything after logging in anyway.
146 static int all_opens_permitted = 0;
149 /* -- X11 forwarding */
151 /* Maximum number of fake X11 displays to try. */
152 #define MAX_DISPLAYS 1000
154 /* Saved X11 local (client) display. */
155 static char *x11_saved_display = NULL;
157 /* Saved X11 authentication protocol name. */
158 static char *x11_saved_proto = NULL;
160 /* Saved X11 authentication data. This is the real data. */
161 static char *x11_saved_data = NULL;
162 static u_int x11_saved_data_len = 0;
164 /* Deadline after which all X11 connections are refused */
165 static u_int x11_refuse_time;
168 * Fake X11 authentication data. This is what the server will be sending us;
169 * we should replace any occurrences of this by the real data.
171 static u_char *x11_fake_data = NULL;
172 static u_int x11_fake_data_len;
175 /* -- agent forwarding */
179 /* AF_UNSPEC or AF_INET or AF_INET6 */
180 static int IPv4or6 = AF_UNSPEC;
183 static void port_open_helper(Channel *c, char *rtype);
185 /* non-blocking connect helpers */
186 static int connect_next(struct channel_connect *);
187 static void channel_connect_ctx_free(struct channel_connect *);
189 /* -- channel core */
192 channel_by_id(int id)
196 if (id < 0 || (u_int)id >= channels_alloc) {
197 logit("channel_by_id: %d: bad id", id);
202 logit("channel_by_id: %d: bad id: channel free", id);
209 * Returns the channel if it is allowed to receive protocol messages.
210 * Private channels, like listening sockets, may not receive messages.
213 channel_lookup(int id)
217 if ((c = channel_by_id(id)) == NULL)
221 case SSH_CHANNEL_X11_OPEN:
222 case SSH_CHANNEL_LARVAL:
223 case SSH_CHANNEL_CONNECTING:
224 case SSH_CHANNEL_DYNAMIC:
225 case SSH_CHANNEL_OPENING:
226 case SSH_CHANNEL_OPEN:
227 case SSH_CHANNEL_INPUT_DRAINING:
228 case SSH_CHANNEL_OUTPUT_DRAINING:
229 case SSH_CHANNEL_ABANDONED:
232 logit("Non-public channel %d, type %d.", id, c->type);
237 * Register filedescriptors for a channel, used when allocating a channel or
238 * when the channel consumer/producer is ready, e.g. shell exec'd
241 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
242 int extusage, int nonblock, int is_tty)
244 /* Update the maximum file descriptor value. */
245 channel_max_fd = MAX(channel_max_fd, rfd);
246 channel_max_fd = MAX(channel_max_fd, wfd);
247 channel_max_fd = MAX(channel_max_fd, efd);
250 fcntl(rfd, F_SETFD, FD_CLOEXEC);
251 if (wfd != -1 && wfd != rfd)
252 fcntl(wfd, F_SETFD, FD_CLOEXEC);
253 if (efd != -1 && efd != rfd && efd != wfd)
254 fcntl(efd, F_SETFD, FD_CLOEXEC);
258 c->sock = (rfd == wfd) ? rfd : -1;
260 c->extended_usage = extusage;
262 if ((c->isatty = is_tty) != 0)
263 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
265 /* XXX: Later AIX versions can't push as much data to tty */
266 c->wfd_isatty = is_tty || isatty(c->wfd);
269 /* enable nonblocking mode */
281 * Allocate a new channel object and set its type and socket. This will cause
282 * remote_name to be freed.
285 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
286 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
292 /* Do initial allocation if this is the first call. */
293 if (channels_alloc == 0) {
295 channels = xcalloc(channels_alloc, sizeof(Channel *));
296 for (i = 0; i < channels_alloc; i++)
299 /* Try to find a free slot where to put the new channel. */
300 for (found = -1, i = 0; i < channels_alloc; i++)
301 if (channels[i] == NULL) {
302 /* Found a free slot. */
307 /* There are no free slots. Take last+1 slot and expand the array. */
308 found = channels_alloc;
309 if (channels_alloc > 10000)
310 fatal("channel_new: internal error: channels_alloc %d "
311 "too big.", channels_alloc);
312 channels = xreallocarray(channels, channels_alloc + 10,
314 channels_alloc += 10;
315 debug2("channel: expanding %d", channels_alloc);
316 for (i = found; i < channels_alloc; i++)
319 /* Initialize and return new channel. */
320 c = channels[found] = xcalloc(1, sizeof(Channel));
321 buffer_init(&c->input);
322 buffer_init(&c->output);
323 buffer_init(&c->extended);
325 c->listening_addr = NULL;
326 c->listening_port = 0;
327 c->ostate = CHAN_OUTPUT_OPEN;
328 c->istate = CHAN_INPUT_OPEN;
330 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
335 c->local_window = window;
336 c->local_window_max = window;
337 c->local_consumed = 0;
338 c->local_maxpacket = maxpack;
340 c->remote_name = xstrdup(remote_name);
341 c->remote_window = 0;
342 c->remote_maxpacket = 0;
344 c->single_connection = 0;
345 c->detach_user = NULL;
347 c->open_confirm = NULL;
348 c->open_confirm_ctx = NULL;
349 c->input_filter = NULL;
350 c->output_filter = NULL;
351 c->filter_ctx = NULL;
352 c->filter_cleanup = NULL;
357 c->delayed = 1; /* prevent call to channel_post handler */
358 TAILQ_INIT(&c->status_confirms);
359 debug("channel %d: new [%s]", found, remote_name);
364 channel_find_maxfd(void)
370 for (i = 0; i < channels_alloc; i++) {
373 max = MAX(max, c->rfd);
374 max = MAX(max, c->wfd);
375 max = MAX(max, c->efd);
382 channel_close_fd(int *fdp)
384 int ret = 0, fd = *fdp;
389 if (fd == channel_max_fd)
390 channel_max_fd = channel_find_maxfd();
395 /* Close all channel fd/socket. */
397 channel_close_fds(Channel *c)
399 channel_close_fd(&c->sock);
400 channel_close_fd(&c->rfd);
401 channel_close_fd(&c->wfd);
402 channel_close_fd(&c->efd);
405 /* Free the channel and close its fd/socket. */
407 channel_free(Channel *c)
411 struct channel_confirm *cc;
413 for (n = 0, i = 0; i < channels_alloc; i++)
416 debug("channel %d: free: %s, nchannels %u", c->self,
417 c->remote_name ? c->remote_name : "???", n);
419 s = channel_open_message();
420 debug3("channel %d: status: %s", c->self, s);
424 shutdown(c->sock, SHUT_RDWR);
425 channel_close_fds(c);
426 buffer_free(&c->input);
427 buffer_free(&c->output);
428 buffer_free(&c->extended);
429 free(c->remote_name);
430 c->remote_name = NULL;
433 free(c->listening_addr);
434 c->listening_addr = NULL;
435 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
436 if (cc->abandon_cb != NULL)
437 cc->abandon_cb(c, cc->ctx);
438 TAILQ_REMOVE(&c->status_confirms, cc, entry);
439 explicit_bzero(cc, sizeof(*cc));
442 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
443 c->filter_cleanup(c->self, c->filter_ctx);
444 channels[c->self] = NULL;
449 channel_free_all(void)
453 for (i = 0; i < channels_alloc; i++)
454 if (channels[i] != NULL)
455 channel_free(channels[i]);
459 * Closes the sockets/fds of all channels. This is used to close extra file
460 * descriptors after a fork.
463 channel_close_all(void)
467 for (i = 0; i < channels_alloc; i++)
468 if (channels[i] != NULL)
469 channel_close_fds(channels[i]);
473 * Stop listening to channels.
476 channel_stop_listening(void)
481 for (i = 0; i < channels_alloc; i++) {
485 case SSH_CHANNEL_AUTH_SOCKET:
486 case SSH_CHANNEL_PORT_LISTENER:
487 case SSH_CHANNEL_RPORT_LISTENER:
488 case SSH_CHANNEL_X11_LISTENER:
489 case SSH_CHANNEL_UNIX_LISTENER:
490 case SSH_CHANNEL_RUNIX_LISTENER:
491 channel_close_fd(&c->sock);
500 * Returns true if no channel has too much buffered data, and false if one or
501 * more channel is overfull.
504 channel_not_very_much_buffered_data(void)
509 for (i = 0; i < channels_alloc; i++) {
511 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
514 buffer_len(&c->input) > packet_get_maxsize()) {
515 debug2("channel %d: big input buffer %d",
516 c->self, buffer_len(&c->input));
520 if (buffer_len(&c->output) > packet_get_maxsize()) {
521 debug2("channel %d: big output buffer %u > %u",
522 c->self, buffer_len(&c->output),
523 packet_get_maxsize());
531 /* Returns true if any channel is still open. */
533 channel_still_open(void)
538 for (i = 0; i < channels_alloc; i++) {
543 case SSH_CHANNEL_X11_LISTENER:
544 case SSH_CHANNEL_PORT_LISTENER:
545 case SSH_CHANNEL_RPORT_LISTENER:
546 case SSH_CHANNEL_MUX_LISTENER:
547 case SSH_CHANNEL_CLOSED:
548 case SSH_CHANNEL_AUTH_SOCKET:
549 case SSH_CHANNEL_DYNAMIC:
550 case SSH_CHANNEL_CONNECTING:
551 case SSH_CHANNEL_ZOMBIE:
552 case SSH_CHANNEL_ABANDONED:
553 case SSH_CHANNEL_UNIX_LISTENER:
554 case SSH_CHANNEL_RUNIX_LISTENER:
556 case SSH_CHANNEL_LARVAL:
558 fatal("cannot happen: SSH_CHANNEL_LARVAL");
560 case SSH_CHANNEL_OPENING:
561 case SSH_CHANNEL_OPEN:
562 case SSH_CHANNEL_X11_OPEN:
563 case SSH_CHANNEL_MUX_CLIENT:
565 case SSH_CHANNEL_INPUT_DRAINING:
566 case SSH_CHANNEL_OUTPUT_DRAINING:
568 fatal("cannot happen: OUT_DRAIN");
571 fatal("channel_still_open: bad channel type %d", c->type);
578 /* Returns the id of an open channel suitable for keepaliving */
580 channel_find_open(void)
585 for (i = 0; i < channels_alloc; i++) {
587 if (c == NULL || c->remote_id < 0)
590 case SSH_CHANNEL_CLOSED:
591 case SSH_CHANNEL_DYNAMIC:
592 case SSH_CHANNEL_X11_LISTENER:
593 case SSH_CHANNEL_PORT_LISTENER:
594 case SSH_CHANNEL_RPORT_LISTENER:
595 case SSH_CHANNEL_MUX_LISTENER:
596 case SSH_CHANNEL_MUX_CLIENT:
597 case SSH_CHANNEL_OPENING:
598 case SSH_CHANNEL_CONNECTING:
599 case SSH_CHANNEL_ZOMBIE:
600 case SSH_CHANNEL_ABANDONED:
601 case SSH_CHANNEL_UNIX_LISTENER:
602 case SSH_CHANNEL_RUNIX_LISTENER:
604 case SSH_CHANNEL_LARVAL:
605 case SSH_CHANNEL_AUTH_SOCKET:
606 case SSH_CHANNEL_OPEN:
607 case SSH_CHANNEL_X11_OPEN:
609 case SSH_CHANNEL_INPUT_DRAINING:
610 case SSH_CHANNEL_OUTPUT_DRAINING:
612 fatal("cannot happen: OUT_DRAIN");
615 fatal("channel_find_open: bad channel type %d", c->type);
624 * Returns a message describing the currently open forwarded connections,
625 * suitable for sending to the client. The message contains crlf pairs for
629 channel_open_message(void)
636 buffer_init(&buffer);
637 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
638 buffer_append(&buffer, buf, strlen(buf));
639 for (i = 0; i < channels_alloc; i++) {
644 case SSH_CHANNEL_X11_LISTENER:
645 case SSH_CHANNEL_PORT_LISTENER:
646 case SSH_CHANNEL_RPORT_LISTENER:
647 case SSH_CHANNEL_CLOSED:
648 case SSH_CHANNEL_AUTH_SOCKET:
649 case SSH_CHANNEL_ZOMBIE:
650 case SSH_CHANNEL_ABANDONED:
651 case SSH_CHANNEL_MUX_CLIENT:
652 case SSH_CHANNEL_MUX_LISTENER:
653 case SSH_CHANNEL_UNIX_LISTENER:
654 case SSH_CHANNEL_RUNIX_LISTENER:
656 case SSH_CHANNEL_LARVAL:
657 case SSH_CHANNEL_OPENING:
658 case SSH_CHANNEL_CONNECTING:
659 case SSH_CHANNEL_DYNAMIC:
660 case SSH_CHANNEL_OPEN:
661 case SSH_CHANNEL_X11_OPEN:
662 case SSH_CHANNEL_INPUT_DRAINING:
663 case SSH_CHANNEL_OUTPUT_DRAINING:
664 snprintf(buf, sizeof buf,
665 " #%d %.300s (t%d r%d i%u/%d o%u/%d fd %d/%d cc %d)\r\n",
666 c->self, c->remote_name,
667 c->type, c->remote_id,
668 c->istate, buffer_len(&c->input),
669 c->ostate, buffer_len(&c->output),
670 c->rfd, c->wfd, c->ctl_chan);
671 buffer_append(&buffer, buf, strlen(buf));
674 fatal("channel_open_message: bad channel type %d", c->type);
678 buffer_append(&buffer, "\0", 1);
679 cp = xstrdup((char *)buffer_ptr(&buffer));
680 buffer_free(&buffer);
685 channel_send_open(int id)
687 Channel *c = channel_lookup(id);
690 logit("channel_send_open: %d: bad id", id);
693 debug2("channel %d: send open", id);
694 packet_start(SSH2_MSG_CHANNEL_OPEN);
695 packet_put_cstring(c->ctype);
696 packet_put_int(c->self);
697 packet_put_int(c->local_window);
698 packet_put_int(c->local_maxpacket);
703 channel_request_start(int id, char *service, int wantconfirm)
705 Channel *c = channel_lookup(id);
708 logit("channel_request_start: %d: unknown channel id", id);
711 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
712 packet_start(SSH2_MSG_CHANNEL_REQUEST);
713 packet_put_int(c->remote_id);
714 packet_put_cstring(service);
715 packet_put_char(wantconfirm);
719 channel_register_status_confirm(int id, channel_confirm_cb *cb,
720 channel_confirm_abandon_cb *abandon_cb, void *ctx)
722 struct channel_confirm *cc;
725 if ((c = channel_lookup(id)) == NULL)
726 fatal("channel_register_expect: %d: bad id", id);
728 cc = xcalloc(1, sizeof(*cc));
730 cc->abandon_cb = abandon_cb;
732 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
736 channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
738 Channel *c = channel_lookup(id);
741 logit("channel_register_open_confirm: %d: bad id", id);
744 c->open_confirm = fn;
745 c->open_confirm_ctx = ctx;
749 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
751 Channel *c = channel_by_id(id);
754 logit("channel_register_cleanup: %d: bad id", id);
758 c->detach_close = do_close;
762 channel_cancel_cleanup(int id)
764 Channel *c = channel_by_id(id);
767 logit("channel_cancel_cleanup: %d: bad id", id);
770 c->detach_user = NULL;
775 channel_register_filter(int id, channel_infilter_fn *ifn,
776 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
778 Channel *c = channel_lookup(id);
781 logit("channel_register_filter: %d: bad id", id);
784 c->input_filter = ifn;
785 c->output_filter = ofn;
787 c->filter_cleanup = cfn;
791 channel_set_fds(int id, int rfd, int wfd, int efd,
792 int extusage, int nonblock, int is_tty, u_int window_max)
794 Channel *c = channel_lookup(id);
796 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
797 fatal("channel_activate for non-larval channel %d.", id);
798 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
799 c->type = SSH_CHANNEL_OPEN;
800 c->local_window = c->local_window_max = window_max;
801 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
802 packet_put_int(c->remote_id);
803 packet_put_int(c->local_window);
808 * 'channel_pre*' are called just before select() to add any bits relevant to
809 * channels in the select bitmasks.
812 * 'channel_post*': perform any appropriate operations for channels which
813 * have events pending.
815 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
816 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
817 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
821 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
823 FD_SET(c->sock, readset);
828 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
830 debug3("channel %d: waiting for connection", c->self);
831 FD_SET(c->sock, writeset);
835 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
837 if (buffer_len(&c->input) < packet_get_maxsize())
838 FD_SET(c->sock, readset);
839 if (buffer_len(&c->output) > 0)
840 FD_SET(c->sock, writeset);
844 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
846 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
848 if (c->istate == CHAN_INPUT_OPEN &&
850 buffer_len(&c->input) < limit &&
851 buffer_check_alloc(&c->input, CHAN_RBUF))
852 FD_SET(c->rfd, readset);
853 if (c->ostate == CHAN_OUTPUT_OPEN ||
854 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
855 if (buffer_len(&c->output) > 0) {
856 FD_SET(c->wfd, writeset);
857 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
858 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
859 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
860 c->self, c->efd, buffer_len(&c->extended));
865 /** XXX check close conditions, too */
866 if (compat20 && c->efd != -1 &&
867 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
868 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
869 buffer_len(&c->extended) > 0)
870 FD_SET(c->efd, writeset);
871 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
872 (c->extended_usage == CHAN_EXTENDED_READ ||
873 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
874 buffer_len(&c->extended) < c->remote_window)
875 FD_SET(c->efd, readset);
877 /* XXX: What about efd? races? */
882 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
884 if (buffer_len(&c->input) == 0) {
885 packet_start(SSH_MSG_CHANNEL_CLOSE);
886 packet_put_int(c->remote_id);
888 c->type = SSH_CHANNEL_CLOSED;
889 debug2("channel %d: closing after input drain.", c->self);
895 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
897 if (buffer_len(&c->output) == 0)
900 FD_SET(c->sock, writeset);
904 * This is a special state for X11 authentication spoofing. An opened X11
905 * connection (when authentication spoofing is being done) remains in this
906 * state until the first packet has been completely read. The authentication
907 * data in that packet is then substituted by the real data if it matches the
908 * fake data, and the channel is put into normal mode.
909 * XXX All this happens at the client side.
910 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
913 x11_open_helper(Buffer *b)
916 u_int proto_len, data_len;
918 /* Is this being called after the refusal deadline? */
919 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
920 verbose("Rejected X11 connection after ForwardX11Timeout "
925 /* Check if the fixed size part of the packet is in buffer. */
926 if (buffer_len(b) < 12)
929 /* Parse the lengths of variable-length fields. */
931 if (ucp[0] == 0x42) { /* Byte order MSB first. */
932 proto_len = 256 * ucp[6] + ucp[7];
933 data_len = 256 * ucp[8] + ucp[9];
934 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
935 proto_len = ucp[6] + 256 * ucp[7];
936 data_len = ucp[8] + 256 * ucp[9];
938 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
943 /* Check if the whole packet is in buffer. */
945 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
948 /* Check if authentication protocol matches. */
949 if (proto_len != strlen(x11_saved_proto) ||
950 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
951 debug2("X11 connection uses different authentication protocol.");
954 /* Check if authentication data matches our fake data. */
955 if (data_len != x11_fake_data_len ||
956 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
957 x11_fake_data, x11_fake_data_len) != 0) {
958 debug2("X11 auth data does not match fake data.");
961 /* Check fake data length */
962 if (x11_fake_data_len != x11_saved_data_len) {
963 error("X11 fake_data_len %d != saved_data_len %d",
964 x11_fake_data_len, x11_saved_data_len);
968 * Received authentication protocol and data match
969 * our fake data. Substitute the fake data with real
972 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
973 x11_saved_data, x11_saved_data_len);
978 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
980 int ret = x11_open_helper(&c->output);
983 /* Start normal processing for the channel. */
984 c->type = SSH_CHANNEL_OPEN;
985 channel_pre_open_13(c, readset, writeset);
986 } else if (ret == -1) {
988 * We have received an X11 connection that has bad
989 * authentication information.
991 logit("X11 connection rejected because of wrong authentication.");
992 buffer_clear(&c->input);
993 buffer_clear(&c->output);
994 channel_close_fd(&c->sock);
996 c->type = SSH_CHANNEL_CLOSED;
997 packet_start(SSH_MSG_CHANNEL_CLOSE);
998 packet_put_int(c->remote_id);
1004 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1006 int ret = x11_open_helper(&c->output);
1008 /* c->force_drain = 1; */
1011 c->type = SSH_CHANNEL_OPEN;
1012 channel_pre_open(c, readset, writeset);
1013 } else if (ret == -1) {
1014 logit("X11 connection rejected because of wrong authentication.");
1015 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1016 chan_read_failed(c);
1017 buffer_clear(&c->input);
1019 buffer_clear(&c->output);
1020 /* for proto v1, the peer will send an IEOF */
1022 chan_write_failed(c);
1024 c->type = SSH_CHANNEL_OPEN;
1025 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1030 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1032 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1033 buffer_check_alloc(&c->input, CHAN_RBUF))
1034 FD_SET(c->rfd, readset);
1035 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1036 /* clear buffer immediately (discard any partial packet) */
1037 buffer_clear(&c->input);
1039 /* Start output drain. XXX just kill chan? */
1040 chan_rcvd_oclose(c);
1042 if (c->ostate == CHAN_OUTPUT_OPEN ||
1043 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1044 if (buffer_len(&c->output) > 0)
1045 FD_SET(c->wfd, writeset);
1046 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1051 /* try to decode a socks4 header */
1054 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1057 u_int len, have, i, found, need;
1062 u_int16_t dest_port;
1063 struct in_addr dest_addr;
1066 debug2("channel %d: decode socks4", c->self);
1068 have = buffer_len(&c->input);
1069 len = sizeof(s4_req);
1072 p = (char *)buffer_ptr(&c->input);
1075 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1076 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1077 debug2("channel %d: socks4a request", c->self);
1078 /* ... and needs an extra string (the hostname) */
1081 /* Check for terminating NUL on the string(s) */
1082 for (found = 0, i = len; i < have; i++) {
1089 /* the peer is probably sending garbage */
1090 debug("channel %d: decode socks4: too long",
1097 buffer_get(&c->input, (char *)&s4_req.version, 1);
1098 buffer_get(&c->input, (char *)&s4_req.command, 1);
1099 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1100 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1101 have = buffer_len(&c->input);
1102 p = (char *)buffer_ptr(&c->input);
1103 if (memchr(p, '\0', have) == NULL)
1104 fatal("channel %d: decode socks4: user not nul terminated",
1107 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1108 len++; /* trailing '\0' */
1110 fatal("channel %d: decode socks4: len %d > have %d",
1111 c->self, len, have);
1112 strlcpy(username, p, sizeof(username));
1113 buffer_consume(&c->input, len);
1117 if (need == 1) { /* SOCKS4: one string */
1118 host = inet_ntoa(s4_req.dest_addr);
1119 c->path = xstrdup(host);
1120 } else { /* SOCKS4A: two strings */
1121 have = buffer_len(&c->input);
1122 p = (char *)buffer_ptr(&c->input);
1124 debug2("channel %d: decode socks4a: host %s/%d",
1126 len++; /* trailing '\0' */
1128 fatal("channel %d: decode socks4a: len %d > have %d",
1129 c->self, len, have);
1130 if (len > NI_MAXHOST) {
1131 error("channel %d: hostname \"%.100s\" too long",
1135 c->path = xstrdup(p);
1136 buffer_consume(&c->input, len);
1138 c->host_port = ntohs(s4_req.dest_port);
1140 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1141 c->self, c->path, c->host_port, s4_req.command);
1143 if (s4_req.command != 1) {
1144 debug("channel %d: cannot handle: %s cn %d",
1145 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1148 s4_rsp.version = 0; /* vn: 0 for reply */
1149 s4_rsp.command = 90; /* cd: req granted */
1150 s4_rsp.dest_port = 0; /* ignored */
1151 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1152 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1156 /* try to decode a socks5 header */
1157 #define SSH_SOCKS5_AUTHDONE 0x1000
1158 #define SSH_SOCKS5_NOAUTH 0x00
1159 #define SSH_SOCKS5_IPV4 0x01
1160 #define SSH_SOCKS5_DOMAIN 0x03
1161 #define SSH_SOCKS5_IPV6 0x04
1162 #define SSH_SOCKS5_CONNECT 0x01
1163 #define SSH_SOCKS5_SUCCESS 0x00
1167 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1175 u_int16_t dest_port;
1176 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1178 u_int have, need, i, found, nmethods, addrlen, af;
1180 debug2("channel %d: decode socks5", c->self);
1181 p = buffer_ptr(&c->input);
1184 have = buffer_len(&c->input);
1185 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1186 /* format: ver | nmethods | methods */
1190 if (have < nmethods + 2)
1192 /* look for method: "NO AUTHENTICATION REQUIRED" */
1193 for (found = 0, i = 2; i < nmethods + 2; i++) {
1194 if (p[i] == SSH_SOCKS5_NOAUTH) {
1200 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1204 buffer_consume(&c->input, nmethods + 2);
1205 buffer_put_char(&c->output, 0x05); /* version */
1206 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1207 FD_SET(c->sock, writeset);
1208 c->flags |= SSH_SOCKS5_AUTHDONE;
1209 debug2("channel %d: socks5 auth done", c->self);
1210 return 0; /* need more */
1212 debug2("channel %d: socks5 post auth", c->self);
1213 if (have < sizeof(s5_req)+1)
1214 return 0; /* need more */
1215 memcpy(&s5_req, p, sizeof(s5_req));
1216 if (s5_req.version != 0x05 ||
1217 s5_req.command != SSH_SOCKS5_CONNECT ||
1218 s5_req.reserved != 0x00) {
1219 debug2("channel %d: only socks5 connect supported", c->self);
1222 switch (s5_req.atyp){
1223 case SSH_SOCKS5_IPV4:
1227 case SSH_SOCKS5_DOMAIN:
1228 addrlen = p[sizeof(s5_req)];
1231 case SSH_SOCKS5_IPV6:
1236 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1239 need = sizeof(s5_req) + addrlen + 2;
1240 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1244 buffer_consume(&c->input, sizeof(s5_req));
1245 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1246 buffer_consume(&c->input, 1); /* host string length */
1247 buffer_get(&c->input, &dest_addr, addrlen);
1248 buffer_get(&c->input, (char *)&dest_port, 2);
1249 dest_addr[addrlen] = '\0';
1252 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1253 if (addrlen >= NI_MAXHOST) {
1254 error("channel %d: dynamic request: socks5 hostname "
1255 "\"%.100s\" too long", c->self, dest_addr);
1258 c->path = xstrdup(dest_addr);
1260 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1262 c->path = xstrdup(ntop);
1264 c->host_port = ntohs(dest_port);
1266 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1267 c->self, c->path, c->host_port, s5_req.command);
1269 s5_rsp.version = 0x05;
1270 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1271 s5_rsp.reserved = 0; /* ignored */
1272 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1273 dest_port = 0; /* ignored */
1275 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1276 buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1277 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1282 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1287 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1290 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1291 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1292 0, "stdio-forward", /*nonblock*/0);
1294 c->path = xstrdup(host_to_connect);
1295 c->host_port = port_to_connect;
1296 c->listening_port = 0;
1299 channel_register_fds(c, in, out, -1, 0, 1, 0);
1300 port_open_helper(c, "direct-tcpip");
1305 /* dynamic port forwarding */
1307 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1313 have = buffer_len(&c->input);
1314 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1315 /* buffer_dump(&c->input); */
1316 /* check if the fixed size part of the packet is in buffer. */
1319 FD_SET(c->sock, readset);
1322 /* try to guess the protocol */
1323 p = buffer_ptr(&c->input);
1326 ret = channel_decode_socks4(c, readset, writeset);
1329 ret = channel_decode_socks5(c, readset, writeset);
1337 } else if (ret == 0) {
1338 debug2("channel %d: pre_dynamic: need more", c->self);
1340 FD_SET(c->sock, readset);
1342 /* switch to the next state */
1343 c->type = SSH_CHANNEL_OPENING;
1344 port_open_helper(c, "direct-tcpip");
1348 /* This is our fake X11 server socket. */
1351 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1354 struct sockaddr_storage addr;
1355 int newsock, oerrno;
1357 char buf[16384], *remote_ipaddr;
1360 if (FD_ISSET(c->sock, readset)) {
1361 debug("X11 connection requested.");
1362 addrlen = sizeof(addr);
1363 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1364 if (c->single_connection) {
1366 debug2("single_connection: closing X11 listener.");
1367 channel_close_fd(&c->sock);
1372 if (errno != EINTR && errno != EWOULDBLOCK &&
1373 errno != ECONNABORTED)
1374 error("accept: %.100s", strerror(errno));
1375 if (errno == EMFILE || errno == ENFILE)
1376 c->notbefore = monotime() + 1;
1379 set_nodelay(newsock);
1380 remote_ipaddr = get_peer_ipaddr(newsock);
1381 remote_port = get_peer_port(newsock);
1382 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1383 remote_ipaddr, remote_port);
1385 nc = channel_new("accepted x11 socket",
1386 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1387 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1389 packet_start(SSH2_MSG_CHANNEL_OPEN);
1390 packet_put_cstring("x11");
1391 packet_put_int(nc->self);
1392 packet_put_int(nc->local_window_max);
1393 packet_put_int(nc->local_maxpacket);
1394 /* originator ipaddr and port */
1395 packet_put_cstring(remote_ipaddr);
1396 if (datafellows & SSH_BUG_X11FWD) {
1397 debug2("ssh2 x11 bug compat mode");
1399 packet_put_int(remote_port);
1403 packet_start(SSH_SMSG_X11_OPEN);
1404 packet_put_int(nc->self);
1405 if (packet_get_protocol_flags() &
1406 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1407 packet_put_cstring(buf);
1410 free(remote_ipaddr);
1415 port_open_helper(Channel *c, char *rtype)
1418 char *local_ipaddr = get_local_ipaddr(c->sock);
1419 int local_port = c->sock == -1 ? 65536 : get_sock_port(c->sock, 1);
1420 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1421 int remote_port = get_peer_port(c->sock);
1423 if (remote_port == -1) {
1424 /* Fake addr/port to appease peers that validate it (Tectia) */
1425 free(remote_ipaddr);
1426 remote_ipaddr = xstrdup("127.0.0.1");
1427 remote_port = 65535;
1430 snprintf(buf, sizeof buf,
1431 "%s: listening port %d for %.100s port %d, "
1432 "connect from %.200s port %d to %.100s port %d",
1433 rtype, c->listening_port, c->path, c->host_port,
1434 remote_ipaddr, remote_port, local_ipaddr, local_port);
1436 free(c->remote_name);
1437 c->remote_name = xstrdup(buf);
1440 packet_start(SSH2_MSG_CHANNEL_OPEN);
1441 packet_put_cstring(rtype);
1442 packet_put_int(c->self);
1443 packet_put_int(c->local_window_max);
1444 packet_put_int(c->local_maxpacket);
1445 if (strcmp(rtype, "direct-tcpip") == 0) {
1446 /* target host, port */
1447 packet_put_cstring(c->path);
1448 packet_put_int(c->host_port);
1449 } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1451 packet_put_cstring(c->path);
1452 } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1454 packet_put_cstring(c->path);
1456 /* listen address, port */
1457 packet_put_cstring(c->path);
1458 packet_put_int(local_port);
1460 if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1461 /* reserved for future owner/mode info */
1462 packet_put_cstring("");
1464 /* originator host and port */
1465 packet_put_cstring(remote_ipaddr);
1466 packet_put_int((u_int)remote_port);
1470 packet_start(SSH_MSG_PORT_OPEN);
1471 packet_put_int(c->self);
1472 packet_put_cstring(c->path);
1473 packet_put_int(c->host_port);
1474 if (packet_get_protocol_flags() &
1475 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1476 packet_put_cstring(c->remote_name);
1479 free(remote_ipaddr);
1484 channel_set_reuseaddr(int fd)
1489 * Set socket options.
1490 * Allow local port reuse in TIME_WAIT.
1492 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1493 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1497 channel_set_x11_refuse_time(u_int refuse_time)
1499 x11_refuse_time = refuse_time;
1503 * This socket is listening for connections to a forwarded TCP/IP port.
1507 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1510 struct sockaddr_storage addr;
1511 int newsock, nextstate;
1515 if (FD_ISSET(c->sock, readset)) {
1516 debug("Connection to port %d forwarding "
1517 "to %.100s port %d requested.",
1518 c->listening_port, c->path, c->host_port);
1520 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1521 nextstate = SSH_CHANNEL_OPENING;
1522 rtype = "forwarded-tcpip";
1523 } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1524 nextstate = SSH_CHANNEL_OPENING;
1525 rtype = "forwarded-streamlocal@openssh.com";
1526 } else if (c->host_port == PORT_STREAMLOCAL) {
1527 nextstate = SSH_CHANNEL_OPENING;
1528 rtype = "direct-streamlocal@openssh.com";
1529 } else if (c->host_port == 0) {
1530 nextstate = SSH_CHANNEL_DYNAMIC;
1531 rtype = "dynamic-tcpip";
1533 nextstate = SSH_CHANNEL_OPENING;
1534 rtype = "direct-tcpip";
1537 addrlen = sizeof(addr);
1538 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1540 if (errno != EINTR && errno != EWOULDBLOCK &&
1541 errno != ECONNABORTED)
1542 error("accept: %.100s", strerror(errno));
1543 if (errno == EMFILE || errno == ENFILE)
1544 c->notbefore = monotime() + 1;
1547 if (c->host_port != PORT_STREAMLOCAL)
1548 set_nodelay(newsock);
1549 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1550 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1551 nc->listening_port = c->listening_port;
1552 nc->host_port = c->host_port;
1553 if (c->path != NULL)
1554 nc->path = xstrdup(c->path);
1556 if (nextstate != SSH_CHANNEL_DYNAMIC)
1557 port_open_helper(nc, rtype);
1562 * This is the authentication agent socket listening for connections from
1567 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1571 struct sockaddr_storage addr;
1574 if (FD_ISSET(c->sock, readset)) {
1575 addrlen = sizeof(addr);
1576 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1578 error("accept from auth socket: %.100s",
1580 if (errno == EMFILE || errno == ENFILE)
1581 c->notbefore = monotime() + 1;
1584 nc = channel_new("accepted auth socket",
1585 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1586 c->local_window_max, c->local_maxpacket,
1587 0, "accepted auth socket", 1);
1589 packet_start(SSH2_MSG_CHANNEL_OPEN);
1590 packet_put_cstring("auth-agent@openssh.com");
1591 packet_put_int(nc->self);
1592 packet_put_int(c->local_window_max);
1593 packet_put_int(c->local_maxpacket);
1595 packet_start(SSH_SMSG_AGENT_OPEN);
1596 packet_put_int(nc->self);
1604 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1607 socklen_t sz = sizeof(err);
1609 if (FD_ISSET(c->sock, writeset)) {
1610 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1612 error("getsockopt SO_ERROR failed");
1615 debug("channel %d: connected to %s port %d",
1616 c->self, c->connect_ctx.host, c->connect_ctx.port);
1617 channel_connect_ctx_free(&c->connect_ctx);
1618 c->type = SSH_CHANNEL_OPEN;
1620 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1621 packet_put_int(c->remote_id);
1622 packet_put_int(c->self);
1623 packet_put_int(c->local_window);
1624 packet_put_int(c->local_maxpacket);
1626 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1627 packet_put_int(c->remote_id);
1628 packet_put_int(c->self);
1631 debug("channel %d: connection failed: %s",
1632 c->self, strerror(err));
1633 /* Try next address, if any */
1634 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1636 c->sock = c->rfd = c->wfd = sock;
1637 channel_max_fd = channel_find_maxfd();
1640 /* Exhausted all addresses */
1641 error("connect_to %.100s port %d: failed.",
1642 c->connect_ctx.host, c->connect_ctx.port);
1643 channel_connect_ctx_free(&c->connect_ctx);
1645 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1646 packet_put_int(c->remote_id);
1647 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1648 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1649 packet_put_cstring(strerror(err));
1650 packet_put_cstring("");
1653 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1654 packet_put_int(c->remote_id);
1664 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1666 char buf[CHAN_RBUF];
1669 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1670 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1672 len = read(c->rfd, buf, sizeof(buf));
1673 if (len < 0 && (errno == EINTR ||
1674 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1676 #ifndef PTY_ZEROREAD
1679 if ((!c->isatty && len <= 0) ||
1680 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1682 debug2("channel %d: read<=0 rfd %d len %d",
1683 c->self, c->rfd, len);
1684 if (c->type != SSH_CHANNEL_OPEN) {
1685 debug2("channel %d: not open", c->self);
1688 } else if (compat13) {
1689 buffer_clear(&c->output);
1690 c->type = SSH_CHANNEL_INPUT_DRAINING;
1691 debug2("channel %d: input draining.", c->self);
1693 chan_read_failed(c);
1697 if (c->input_filter != NULL) {
1698 if (c->input_filter(c, buf, len) == -1) {
1699 debug2("channel %d: filter stops", c->self);
1700 chan_read_failed(c);
1702 } else if (c->datagram) {
1703 buffer_put_string(&c->input, buf, len);
1705 buffer_append(&c->input, buf, len);
1713 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1716 u_char *data = NULL, *buf;
1717 u_int dlen, olen = 0;
1720 /* Send buffered output data to the socket. */
1722 FD_ISSET(c->wfd, writeset) &&
1723 buffer_len(&c->output) > 0) {
1724 olen = buffer_len(&c->output);
1725 if (c->output_filter != NULL) {
1726 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1727 debug2("channel %d: filter stops", c->self);
1728 if (c->type != SSH_CHANNEL_OPEN)
1731 chan_write_failed(c);
1734 } else if (c->datagram) {
1735 buf = data = buffer_get_string(&c->output, &dlen);
1737 buf = data = buffer_ptr(&c->output);
1738 dlen = buffer_len(&c->output);
1742 /* ignore truncated writes, datagrams might get lost */
1743 len = write(c->wfd, buf, dlen);
1745 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1746 errno == EWOULDBLOCK))
1749 if (c->type != SSH_CHANNEL_OPEN)
1752 chan_write_failed(c);
1758 /* XXX: Later AIX versions can't push as much data to tty */
1759 if (compat20 && c->wfd_isatty)
1760 dlen = MIN(dlen, 8*1024);
1763 len = write(c->wfd, buf, dlen);
1765 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1768 if (c->type != SSH_CHANNEL_OPEN) {
1769 debug2("channel %d: not open", c->self);
1772 } else if (compat13) {
1773 buffer_clear(&c->output);
1774 debug2("channel %d: input draining.", c->self);
1775 c->type = SSH_CHANNEL_INPUT_DRAINING;
1777 chan_write_failed(c);
1781 #ifndef BROKEN_TCGETATTR_ICANON
1782 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1783 if (tcgetattr(c->wfd, &tio) == 0 &&
1784 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1786 * Simulate echo to reduce the impact of
1787 * traffic analysis. We need to match the
1788 * size of a SSH2_MSG_CHANNEL_DATA message
1789 * (4 byte channel id + buf)
1791 packet_send_ignore(4 + len);
1796 buffer_consume(&c->output, len);
1799 if (compat20 && olen > 0)
1800 c->local_consumed += olen - buffer_len(&c->output);
1805 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1807 char buf[CHAN_RBUF];
1810 /** XXX handle drain efd, too */
1812 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1813 FD_ISSET(c->efd, writeset) &&
1814 buffer_len(&c->extended) > 0) {
1815 len = write(c->efd, buffer_ptr(&c->extended),
1816 buffer_len(&c->extended));
1817 debug2("channel %d: written %d to efd %d",
1818 c->self, len, c->efd);
1819 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1820 errno == EWOULDBLOCK))
1823 debug2("channel %d: closing write-efd %d",
1825 channel_close_fd(&c->efd);
1827 buffer_consume(&c->extended, len);
1828 c->local_consumed += len;
1830 } else if (c->efd != -1 &&
1831 (c->extended_usage == CHAN_EXTENDED_READ ||
1832 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1833 (c->detach_close || FD_ISSET(c->efd, readset))) {
1834 len = read(c->efd, buf, sizeof(buf));
1835 debug2("channel %d: read %d from efd %d",
1836 c->self, len, c->efd);
1837 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1838 errno == EWOULDBLOCK) && !c->detach_close)))
1841 debug2("channel %d: closing read-efd %d",
1843 channel_close_fd(&c->efd);
1845 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1846 debug3("channel %d: discard efd",
1849 buffer_append(&c->extended, buf, len);
1857 channel_check_window(Channel *c)
1859 if (c->type == SSH_CHANNEL_OPEN &&
1860 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1861 ((c->local_window_max - c->local_window >
1862 c->local_maxpacket*3) ||
1863 c->local_window < c->local_window_max/2) &&
1864 c->local_consumed > 0) {
1865 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1866 packet_put_int(c->remote_id);
1867 packet_put_int(c->local_consumed);
1869 debug2("channel %d: window %d sent adjust %d",
1870 c->self, c->local_window,
1872 c->local_window += c->local_consumed;
1873 c->local_consumed = 0;
1879 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1881 channel_handle_rfd(c, readset, writeset);
1882 channel_handle_wfd(c, readset, writeset);
1885 channel_handle_efd(c, readset, writeset);
1886 channel_check_window(c);
1890 read_mux(Channel *c, u_int need)
1892 char buf[CHAN_RBUF];
1896 if (buffer_len(&c->input) < need) {
1897 rlen = need - buffer_len(&c->input);
1898 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1899 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1900 return buffer_len(&c->input);
1902 debug2("channel %d: ctl read<=0 rfd %d len %d",
1903 c->self, c->rfd, len);
1904 chan_read_failed(c);
1907 buffer_append(&c->input, buf, len);
1909 return buffer_len(&c->input);
1913 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1919 fatal("%s: entered with !compat20", __func__);
1921 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1922 (c->istate == CHAN_INPUT_OPEN ||
1923 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1925 * Don't not read past the precise end of packets to
1926 * avoid disrupting fd passing.
1928 if (read_mux(c, 4) < 4) /* read header */
1930 need = get_u32(buffer_ptr(&c->input));
1931 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1932 if (need > CHANNEL_MUX_MAX_PACKET) {
1933 debug2("channel %d: packet too big %u > %u",
1934 c->self, CHANNEL_MUX_MAX_PACKET, need);
1935 chan_rcvd_oclose(c);
1938 if (read_mux(c, need + 4) < need + 4) /* read body */
1940 if (c->mux_rcb(c) != 0) {
1941 debug("channel %d: mux_rcb failed", c->self);
1947 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1948 buffer_len(&c->output) > 0) {
1949 len = write(c->wfd, buffer_ptr(&c->output),
1950 buffer_len(&c->output));
1951 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1957 buffer_consume(&c->output, len);
1962 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1965 struct sockaddr_storage addr;
1971 if (!FD_ISSET(c->sock, readset))
1974 debug("multiplexing control connection");
1977 * Accept connection on control socket
1979 memset(&addr, 0, sizeof(addr));
1980 addrlen = sizeof(addr);
1981 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1983 error("%s accept: %s", __func__, strerror(errno));
1984 if (errno == EMFILE || errno == ENFILE)
1985 c->notbefore = monotime() + 1;
1989 if (getpeereid(newsock, &euid, &egid) < 0) {
1990 error("%s getpeereid failed: %s", __func__,
1995 if ((euid != 0) && (getuid() != euid)) {
1996 error("multiplex uid mismatch: peer euid %u != uid %u",
1997 (u_int)euid, (u_int)getuid());
2001 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
2002 newsock, newsock, -1, c->local_window_max,
2003 c->local_maxpacket, 0, "mux-control", 1);
2004 nc->mux_rcb = c->mux_rcb;
2005 debug3("%s: new mux channel %d fd %d", __func__,
2006 nc->self, nc->sock);
2007 /* establish state */
2009 /* mux state transitions must not elicit protocol messages */
2010 nc->flags |= CHAN_LOCAL;
2015 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
2019 /* Send buffered output data to the socket. */
2020 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2021 len = write(c->sock, buffer_ptr(&c->output),
2022 buffer_len(&c->output));
2024 buffer_clear(&c->output);
2026 buffer_consume(&c->output, len);
2031 channel_handler_init_20(void)
2033 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2034 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2035 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2036 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2037 channel_pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2038 channel_pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
2039 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2040 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2041 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2042 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2043 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2044 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2046 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2047 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2048 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2049 channel_post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2050 channel_post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
2051 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2052 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2053 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2054 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2055 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2056 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2060 channel_handler_init_13(void)
2062 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2063 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2064 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2065 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2066 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2067 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2068 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2069 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2070 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2072 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2073 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2074 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2075 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2076 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2077 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2078 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2082 channel_handler_init_15(void)
2084 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2085 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2086 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2087 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2088 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2089 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2090 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2092 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2093 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2094 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2095 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2096 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2097 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2101 channel_handler_init(void)
2105 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2106 channel_pre[i] = NULL;
2107 channel_post[i] = NULL;
2110 channel_handler_init_20();
2112 channel_handler_init_13();
2114 channel_handler_init_15();
2117 /* gc dead channels */
2119 channel_garbage_collect(Channel *c)
2123 if (c->detach_user != NULL) {
2124 if (!chan_is_dead(c, c->detach_close))
2126 debug2("channel %d: gc: notify user", c->self);
2127 c->detach_user(c->self, NULL);
2128 /* if we still have a callback */
2129 if (c->detach_user != NULL)
2131 debug2("channel %d: gc: user detached", c->self);
2133 if (!chan_is_dead(c, 1))
2135 debug2("channel %d: garbage collecting", c->self);
2140 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2141 time_t *unpause_secs)
2143 static int did_init = 0;
2149 channel_handler_init();
2153 if (unpause_secs != NULL)
2155 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2160 if (ftab == channel_pre)
2165 if (ftab[c->type] != NULL) {
2167 * Run handlers that are not paused.
2169 if (c->notbefore <= now)
2170 (*ftab[c->type])(c, readset, writeset);
2171 else if (unpause_secs != NULL) {
2173 * Collect the time that the earliest
2174 * channel comes off pause.
2176 debug3("%s: chan %d: skip for %d more seconds",
2178 (int)(c->notbefore - now));
2179 if (*unpause_secs == 0 ||
2180 (c->notbefore - now) < *unpause_secs)
2181 *unpause_secs = c->notbefore - now;
2184 channel_garbage_collect(c);
2186 if (unpause_secs != NULL && *unpause_secs != 0)
2187 debug3("%s: first channel unpauses in %d seconds",
2188 __func__, (int)*unpause_secs);
2192 * Allocate/update select bitmasks and add any bits relevant to channels in
2196 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2197 u_int *nallocp, time_t *minwait_secs, int rekeying)
2199 u_int n, sz, nfdset;
2201 n = MAX(*maxfdp, channel_max_fd);
2203 nfdset = howmany(n+1, NFDBITS);
2204 /* Explicitly test here, because xrealloc isn't always called */
2205 if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
2206 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2207 sz = nfdset * sizeof(fd_mask);
2209 /* perhaps check sz < nalloc/2 and shrink? */
2210 if (*readsetp == NULL || sz > *nallocp) {
2211 *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
2212 *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
2216 memset(*readsetp, 0, sz);
2217 memset(*writesetp, 0, sz);
2220 channel_handler(channel_pre, *readsetp, *writesetp,
2225 * After select, perform any appropriate operations for channels which have
2229 channel_after_select(fd_set *readset, fd_set *writeset)
2231 channel_handler(channel_post, readset, writeset, NULL);
2235 /* If there is data to send to the connection, enqueue some of it now. */
2237 channel_output_poll(void)
2242 for (i = 0; i < channels_alloc; i++) {
2248 * We are only interested in channels that can have buffered
2252 if (c->type != SSH_CHANNEL_OPEN &&
2253 c->type != SSH_CHANNEL_INPUT_DRAINING)
2256 if (c->type != SSH_CHANNEL_OPEN)
2260 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2261 /* XXX is this true? */
2262 debug3("channel %d: will not send data after close", c->self);
2266 /* Get the amount of buffered data for this channel. */
2267 if ((c->istate == CHAN_INPUT_OPEN ||
2268 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2269 (len = buffer_len(&c->input)) > 0) {
2275 data = buffer_get_string(&c->input,
2277 if (dlen > c->remote_window ||
2278 dlen > c->remote_maxpacket) {
2279 debug("channel %d: datagram "
2280 "too big for channel",
2285 packet_start(SSH2_MSG_CHANNEL_DATA);
2286 packet_put_int(c->remote_id);
2287 packet_put_string(data, dlen);
2289 c->remote_window -= dlen;
2295 * Send some data for the other side over the secure
2299 if (len > c->remote_window)
2300 len = c->remote_window;
2301 if (len > c->remote_maxpacket)
2302 len = c->remote_maxpacket;
2304 if (packet_is_interactive()) {
2308 /* Keep the packets at reasonable size. */
2309 if (len > packet_get_maxsize()/2)
2310 len = packet_get_maxsize()/2;
2314 packet_start(compat20 ?
2315 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2316 packet_put_int(c->remote_id);
2317 packet_put_string(buffer_ptr(&c->input), len);
2319 buffer_consume(&c->input, len);
2320 c->remote_window -= len;
2322 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2324 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2326 * input-buffer is empty and read-socket shutdown:
2327 * tell peer, that we will not send more data: send IEOF.
2328 * hack for extended data: delay EOF if EFD still in use.
2330 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2331 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2332 c->self, c->efd, buffer_len(&c->extended));
2336 /* Send extended data, i.e. stderr */
2338 !(c->flags & CHAN_EOF_SENT) &&
2339 c->remote_window > 0 &&
2340 (len = buffer_len(&c->extended)) > 0 &&
2341 c->extended_usage == CHAN_EXTENDED_READ) {
2342 debug2("channel %d: rwin %u elen %u euse %d",
2343 c->self, c->remote_window, buffer_len(&c->extended),
2345 if (len > c->remote_window)
2346 len = c->remote_window;
2347 if (len > c->remote_maxpacket)
2348 len = c->remote_maxpacket;
2349 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2350 packet_put_int(c->remote_id);
2351 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2352 packet_put_string(buffer_ptr(&c->extended), len);
2354 buffer_consume(&c->extended, len);
2355 c->remote_window -= len;
2356 debug2("channel %d: sent ext data %d", c->self, len);
2362 /* -- protocol input */
2366 channel_input_data(int type, u_int32_t seq, void *ctxt)
2370 u_int data_len, win_len;
2373 /* Get the channel number and verify it. */
2374 id = packet_get_int();
2375 c = channel_lookup(id);
2377 packet_disconnect("Received data for nonexistent channel %d.", id);
2379 /* Ignore any data for non-open channels (might happen on close) */
2380 if (c->type != SSH_CHANNEL_OPEN &&
2381 c->type != SSH_CHANNEL_X11_OPEN)
2385 data = packet_get_string_ptr(&data_len);
2388 win_len += 4; /* string length header */
2391 * Ignore data for protocol > 1.3 if output end is no longer open.
2392 * For protocol 2 the sending side is reducing its window as it sends
2393 * data, so we must 'fake' consumption of the data in order to ensure
2394 * that window updates are sent back. Otherwise the connection might
2397 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2399 c->local_window -= win_len;
2400 c->local_consumed += win_len;
2406 if (win_len > c->local_maxpacket) {
2407 logit("channel %d: rcvd big packet %d, maxpack %d",
2408 c->self, win_len, c->local_maxpacket);
2410 if (win_len > c->local_window) {
2411 logit("channel %d: rcvd too much data %d, win %d",
2412 c->self, win_len, c->local_window);
2415 c->local_window -= win_len;
2418 buffer_put_string(&c->output, data, data_len);
2420 buffer_append(&c->output, data, data_len);
2427 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2431 u_int data_len, tcode;
2434 /* Get the channel number and verify it. */
2435 id = packet_get_int();
2436 c = channel_lookup(id);
2439 packet_disconnect("Received extended_data for bad channel %d.", id);
2440 if (c->type != SSH_CHANNEL_OPEN) {
2441 logit("channel %d: ext data for non open", id);
2444 if (c->flags & CHAN_EOF_RCVD) {
2445 if (datafellows & SSH_BUG_EXTEOF)
2446 debug("channel %d: accepting ext data after eof", id);
2448 packet_disconnect("Received extended_data after EOF "
2449 "on channel %d.", id);
2451 tcode = packet_get_int();
2453 c->extended_usage != CHAN_EXTENDED_WRITE ||
2454 tcode != SSH2_EXTENDED_DATA_STDERR) {
2455 logit("channel %d: bad ext data", c->self);
2458 data = packet_get_string(&data_len);
2460 if (data_len > c->local_window) {
2461 logit("channel %d: rcvd too much extended_data %d, win %d",
2462 c->self, data_len, c->local_window);
2466 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2467 c->local_window -= data_len;
2468 buffer_append(&c->extended, data, data_len);
2475 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2480 id = packet_get_int();
2482 c = channel_lookup(id);
2484 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2487 /* XXX force input close */
2488 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2489 debug("channel %d: FORCE input drain", c->self);
2490 c->istate = CHAN_INPUT_WAIT_DRAIN;
2491 if (buffer_len(&c->input) == 0)
2499 channel_input_close(int type, u_int32_t seq, void *ctxt)
2504 id = packet_get_int();
2506 c = channel_lookup(id);
2508 packet_disconnect("Received close for nonexistent channel %d.", id);
2511 * Send a confirmation that we have closed the channel and no more
2512 * data is coming for it.
2514 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2515 packet_put_int(c->remote_id);
2519 * If the channel is in closed state, we have sent a close request,
2520 * and the other side will eventually respond with a confirmation.
2521 * Thus, we cannot free the channel here, because then there would be
2522 * no-one to receive the confirmation. The channel gets freed when
2523 * the confirmation arrives.
2525 if (c->type != SSH_CHANNEL_CLOSED) {
2527 * Not a closed channel - mark it as draining, which will
2528 * cause it to be freed later.
2530 buffer_clear(&c->input);
2531 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2536 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2539 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2541 int id = packet_get_int();
2542 Channel *c = channel_lookup(id);
2546 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2547 chan_rcvd_oclose(c);
2553 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2555 int id = packet_get_int();
2556 Channel *c = channel_lookup(id);
2560 packet_disconnect("Received close confirmation for "
2561 "out-of-range channel %d.", id);
2562 if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
2563 packet_disconnect("Received close confirmation for "
2564 "non-closed channel %d (type %d).", id, c->type);
2571 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2576 id = packet_get_int();
2577 c = channel_lookup(id);
2579 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2580 packet_disconnect("Received open confirmation for "
2581 "non-opening channel %d.", id);
2582 remote_id = packet_get_int();
2583 /* Record the remote channel number and mark that the channel is now open. */
2584 c->remote_id = remote_id;
2585 c->type = SSH_CHANNEL_OPEN;
2588 c->remote_window = packet_get_int();
2589 c->remote_maxpacket = packet_get_int();
2590 if (c->open_confirm) {
2591 debug2("callback start");
2592 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2593 debug2("callback done");
2595 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2596 c->remote_window, c->remote_maxpacket);
2603 reason2txt(int reason)
2606 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2607 return "administratively prohibited";
2608 case SSH2_OPEN_CONNECT_FAILED:
2609 return "connect failed";
2610 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2611 return "unknown channel type";
2612 case SSH2_OPEN_RESOURCE_SHORTAGE:
2613 return "resource shortage";
2615 return "unknown reason";
2620 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2623 char *msg = NULL, *lang = NULL;
2626 id = packet_get_int();
2627 c = channel_lookup(id);
2629 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2630 packet_disconnect("Received open failure for "
2631 "non-opening channel %d.", id);
2633 reason = packet_get_int();
2634 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2635 msg = packet_get_string(NULL);
2636 lang = packet_get_string(NULL);
2638 logit("channel %d: open failed: %s%s%s", id,
2639 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2642 if (c->open_confirm) {
2643 debug2("callback start");
2644 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2645 debug2("callback done");
2649 /* Schedule the channel for cleanup/deletion. */
2656 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2665 /* Get the channel number and verify it. */
2666 id = packet_get_int();
2667 c = channel_lookup(id);
2670 logit("Received window adjust for non-open channel %d.", id);
2673 adjust = packet_get_int();
2675 debug2("channel %d: rcvd adjust %u", id, adjust);
2676 if ((tmp = c->remote_window + adjust) < c->remote_window)
2677 fatal("channel %d: adjust %u overflows remote window %u",
2678 id, adjust, c->remote_window);
2679 c->remote_window = tmp;
2685 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2689 char *host, *originator_string;
2692 remote_id = packet_get_int();
2693 host = packet_get_string(NULL);
2694 host_port = packet_get_int();
2696 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2697 originator_string = packet_get_string(NULL);
2699 originator_string = xstrdup("unknown (remote did not supply name)");
2702 c = channel_connect_to_port(host, host_port,
2703 "connected socket", originator_string);
2704 free(originator_string);
2707 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2708 packet_put_int(remote_id);
2711 c->remote_id = remote_id;
2717 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2720 struct channel_confirm *cc;
2723 /* Reset keepalive timeout */
2724 packet_set_alive_timeouts(0);
2726 id = packet_get_int();
2729 debug2("channel_input_status_confirm: type %d id %d", type, id);
2731 if ((c = channel_lookup(id)) == NULL) {
2732 logit("channel_input_status_confirm: %d: unknown", id);
2735 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2737 cc->cb(type, c, cc->ctx);
2738 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2739 explicit_bzero(cc, sizeof(*cc));
2744 /* -- tcp forwarding */
2747 channel_set_af(int af)
2754 * Determine whether or not a port forward listens to loopback, the
2755 * specified address or wildcard. On the client, a specified bind
2756 * address will always override gateway_ports. On the server, a
2757 * gateway_ports of 1 (``yes'') will override the client's specification
2758 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2759 * will bind to whatever address the client asked for.
2761 * Special-case listen_addrs are:
2763 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2764 * "" (empty string), "*" -> wildcard v4/v6
2765 * "localhost" -> loopback v4/v6
2766 * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
2769 channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2770 int is_client, struct ForwardOptions *fwd_opts)
2772 const char *addr = NULL;
2775 if (listen_addr == NULL) {
2776 /* No address specified: default to gateway_ports setting */
2777 if (fwd_opts->gateway_ports)
2779 } else if (fwd_opts->gateway_ports || is_client) {
2780 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2781 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2782 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2783 (!is_client && fwd_opts->gateway_ports == 1)) {
2786 * Notify client if they requested a specific listen
2787 * address and it was overridden.
2789 if (*listen_addr != '\0' &&
2790 strcmp(listen_addr, "0.0.0.0") != 0 &&
2791 strcmp(listen_addr, "*") != 0) {
2792 packet_send_debug("Forwarding listen address "
2793 "\"%s\" overridden by server "
2794 "GatewayPorts", listen_addr);
2796 } else if (strcmp(listen_addr, "localhost") != 0 ||
2797 strcmp(listen_addr, "127.0.0.1") == 0 ||
2798 strcmp(listen_addr, "::1") == 0) {
2799 /* Accept localhost address when GatewayPorts=yes */
2802 } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
2803 strcmp(listen_addr, "::1") == 0) {
2805 * If a specific IPv4/IPv6 localhost address has been
2806 * requested then accept it even if gateway_ports is in
2807 * effect. This allows the client to prefer IPv4 or IPv6.
2811 if (wildcardp != NULL)
2812 *wildcardp = wildcard;
2817 channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
2818 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
2821 int sock, r, success = 0, wildcard = 0, is_client;
2822 struct addrinfo hints, *ai, *aitop;
2823 const char *host, *addr;
2824 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2827 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2829 if (is_client && fwd->connect_path != NULL) {
2830 host = fwd->connect_path;
2832 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2833 fwd->listen_host : fwd->connect_host;
2835 error("No forward host name.");
2838 if (strlen(host) >= NI_MAXHOST) {
2839 error("Forward host name too long.");
2844 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2845 addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
2846 is_client, fwd_opts);
2847 debug3("%s: type %d wildcard %d addr %s", __func__,
2848 type, wildcard, (addr == NULL) ? "NULL" : addr);
2851 * getaddrinfo returns a loopback address if the hostname is
2852 * set to NULL and hints.ai_flags is not AI_PASSIVE
2854 memset(&hints, 0, sizeof(hints));
2855 hints.ai_family = IPv4or6;
2856 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2857 hints.ai_socktype = SOCK_STREAM;
2858 snprintf(strport, sizeof strport, "%d", fwd->listen_port);
2859 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2861 /* This really shouldn't happen */
2862 packet_disconnect("getaddrinfo: fatal error: %s",
2863 ssh_gai_strerror(r));
2865 error("%s: getaddrinfo(%.64s): %s", __func__, addr,
2866 ssh_gai_strerror(r));
2870 if (allocated_listen_port != NULL)
2871 *allocated_listen_port = 0;
2872 for (ai = aitop; ai; ai = ai->ai_next) {
2873 switch (ai->ai_family) {
2875 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2879 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2886 * If allocating a port for -R forwards, then use the
2887 * same port for all address families.
2889 if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
2890 allocated_listen_port != NULL && *allocated_listen_port > 0)
2891 *lport_p = htons(*allocated_listen_port);
2893 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2894 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2895 error("%s: getnameinfo failed", __func__);
2898 /* Create a port to listen for the host. */
2899 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2901 /* this is no error since kernel may not support ipv6 */
2902 verbose("socket: %.100s", strerror(errno));
2906 channel_set_reuseaddr(sock);
2907 if (ai->ai_family == AF_INET6)
2908 sock_set_v6only(sock);
2910 debug("Local forwarding listening on %s port %s.",
2913 /* Bind the socket to the address. */
2914 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2915 /* address can be in use ipv6 address is already bound */
2917 error("bind: %.100s", strerror(errno));
2919 verbose("bind: %.100s", strerror(errno));
2924 /* Start listening for connections on the socket. */
2925 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2926 error("listen: %.100s", strerror(errno));
2932 * fwd->listen_port == 0 requests a dynamically allocated port -
2933 * record what we got.
2935 if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
2936 allocated_listen_port != NULL &&
2937 *allocated_listen_port == 0) {
2938 *allocated_listen_port = get_sock_port(sock, 1);
2939 debug("Allocated listen port %d",
2940 *allocated_listen_port);
2943 /* Allocate a channel number for the socket. */
2944 c = channel_new("port listener", type, sock, sock, -1,
2945 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2946 0, "port listener", 1);
2947 c->path = xstrdup(host);
2948 c->host_port = fwd->connect_port;
2949 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2950 if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
2951 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2952 c->listening_port = *allocated_listen_port;
2954 c->listening_port = fwd->listen_port;
2958 error("%s: cannot listen to port: %d", __func__,
2960 freeaddrinfo(aitop);
2965 channel_setup_fwd_listener_streamlocal(int type, struct Forward *fwd,
2966 struct ForwardOptions *fwd_opts)
2968 struct sockaddr_un sunaddr;
2975 case SSH_CHANNEL_UNIX_LISTENER:
2976 if (fwd->connect_path != NULL) {
2977 if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
2978 error("Local connecting path too long: %s",
2982 path = fwd->connect_path;
2983 port = PORT_STREAMLOCAL;
2985 if (fwd->connect_host == NULL) {
2986 error("No forward host name.");
2989 if (strlen(fwd->connect_host) >= NI_MAXHOST) {
2990 error("Forward host name too long.");
2993 path = fwd->connect_host;
2994 port = fwd->connect_port;
2997 case SSH_CHANNEL_RUNIX_LISTENER:
2998 path = fwd->listen_path;
2999 port = PORT_STREAMLOCAL;
3002 error("%s: unexpected channel type %d", __func__, type);
3006 if (fwd->listen_path == NULL) {
3007 error("No forward path name.");
3010 if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
3011 error("Local listening path too long: %s", fwd->listen_path);
3015 debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
3017 /* Start a Unix domain listener. */
3018 omask = umask(fwd_opts->streamlocal_bind_mask);
3019 sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
3020 fwd_opts->streamlocal_bind_unlink);
3025 debug("Local forwarding listening on path %s.", fwd->listen_path);
3027 /* Allocate a channel number for the socket. */
3028 c = channel_new("unix listener", type, sock, sock, -1,
3029 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3030 0, "unix listener", 1);
3031 c->path = xstrdup(path);
3032 c->host_port = port;
3033 c->listening_port = PORT_STREAMLOCAL;
3034 c->listening_addr = xstrdup(fwd->listen_path);
3039 channel_cancel_rport_listener_tcpip(const char *host, u_short port)
3044 for (i = 0; i < channels_alloc; i++) {
3045 Channel *c = channels[i];
3046 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3048 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3049 debug2("%s: close channel %d", __func__, i);
3059 channel_cancel_rport_listener_streamlocal(const char *path)
3064 for (i = 0; i < channels_alloc; i++) {
3065 Channel *c = channels[i];
3066 if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3068 if (c->path == NULL)
3070 if (strcmp(c->path, path) == 0) {
3071 debug2("%s: close channel %d", __func__, i);
3081 channel_cancel_rport_listener(struct Forward *fwd)
3083 if (fwd->listen_path != NULL)
3084 return channel_cancel_rport_listener_streamlocal(fwd->listen_path);
3086 return channel_cancel_rport_listener_tcpip(fwd->listen_host, fwd->listen_port);
3090 channel_cancel_lport_listener_tcpip(const char *lhost, u_short lport,
3091 int cport, struct ForwardOptions *fwd_opts)
3095 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
3097 for (i = 0; i < channels_alloc; i++) {
3098 Channel *c = channels[i];
3099 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
3101 if (c->listening_port != lport)
3103 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
3104 /* skip dynamic forwardings */
3105 if (c->host_port == 0)
3108 if (c->host_port != cport)
3111 if ((c->listening_addr == NULL && addr != NULL) ||
3112 (c->listening_addr != NULL && addr == NULL))
3114 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
3115 debug2("%s: close channel %d", __func__, i);
3125 channel_cancel_lport_listener_streamlocal(const char *path)
3131 error("%s: no path specified.", __func__);
3135 for (i = 0; i < channels_alloc; i++) {
3136 Channel *c = channels[i];
3137 if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
3139 if (c->listening_addr == NULL)
3141 if (strcmp(c->listening_addr, path) == 0) {
3142 debug2("%s: close channel %d", __func__, i);
3152 channel_cancel_lport_listener(struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
3154 if (fwd->listen_path != NULL)
3155 return channel_cancel_lport_listener_streamlocal(fwd->listen_path);
3157 return channel_cancel_lport_listener_tcpip(fwd->listen_host, fwd->listen_port, cport, fwd_opts);
3160 /* protocol local port fwd, used by ssh (and sshd in v1) */
3162 channel_setup_local_fwd_listener(struct Forward *fwd, struct ForwardOptions *fwd_opts)
3164 if (fwd->listen_path != NULL) {
3165 return channel_setup_fwd_listener_streamlocal(
3166 SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
3168 return channel_setup_fwd_listener_tcpip(SSH_CHANNEL_PORT_LISTENER,
3169 fwd, NULL, fwd_opts);
3173 /* protocol v2 remote port fwd, used by sshd */
3175 channel_setup_remote_fwd_listener(struct Forward *fwd,
3176 int *allocated_listen_port, struct ForwardOptions *fwd_opts)
3178 if (fwd->listen_path != NULL) {
3179 return channel_setup_fwd_listener_streamlocal(
3180 SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
3182 return channel_setup_fwd_listener_tcpip(
3183 SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
3189 * Translate the requested rfwd listen host to something usable for
3193 channel_rfwd_bind_host(const char *listen_host)
3195 if (listen_host == NULL) {
3196 if (datafellows & SSH_BUG_RFWD_ADDR)
3200 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3201 if (datafellows & SSH_BUG_RFWD_ADDR)
3210 * Initiate forwarding of connections to port "port" on remote host through
3211 * the secure channel to host:port from local side.
3212 * Returns handle (index) for updating the dynamic listen port with
3213 * channel_update_permitted_opens().
3216 channel_request_remote_forwarding(struct Forward *fwd)
3218 int type, success = 0, idx = -1;
3220 /* Send the forward request to the remote side. */
3222 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3223 if (fwd->listen_path != NULL) {
3224 packet_put_cstring("streamlocal-forward@openssh.com");
3225 packet_put_char(1); /* boolean: want reply */
3226 packet_put_cstring(fwd->listen_path);
3228 packet_put_cstring("tcpip-forward");
3229 packet_put_char(1); /* boolean: want reply */
3230 packet_put_cstring(channel_rfwd_bind_host(fwd->listen_host));
3231 packet_put_int(fwd->listen_port);
3234 packet_write_wait();
3235 /* Assume that server accepts the request */
3237 } else if (fwd->listen_path == NULL) {
3238 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
3239 packet_put_int(fwd->listen_port);
3240 packet_put_cstring(fwd->connect_host);
3241 packet_put_int(fwd->connect_port);
3243 packet_write_wait();
3245 /* Wait for response from the remote side. */
3246 type = packet_read();
3248 case SSH_SMSG_SUCCESS:
3251 case SSH_SMSG_FAILURE:
3254 /* Unknown packet */
3255 packet_disconnect("Protocol error for port forward request:"
3256 "received packet type %d.", type);
3259 logit("Warning: Server does not support remote stream local forwarding.");
3262 /* Record that connection to this host/port is permitted. */
3263 permitted_opens = xreallocarray(permitted_opens,
3264 num_permitted_opens + 1, sizeof(*permitted_opens));
3265 idx = num_permitted_opens++;
3266 if (fwd->connect_path != NULL) {
3267 permitted_opens[idx].host_to_connect =
3268 xstrdup(fwd->connect_path);
3269 permitted_opens[idx].port_to_connect =
3272 permitted_opens[idx].host_to_connect =
3273 xstrdup(fwd->connect_host);
3274 permitted_opens[idx].port_to_connect =
3277 if (fwd->listen_path != NULL) {
3278 permitted_opens[idx].listen_host = NULL;
3279 permitted_opens[idx].listen_path =
3280 xstrdup(fwd->listen_path);
3281 permitted_opens[idx].listen_port = PORT_STREAMLOCAL;
3283 permitted_opens[idx].listen_host =
3284 fwd->listen_host ? xstrdup(fwd->listen_host) : NULL;
3285 permitted_opens[idx].listen_path = NULL;
3286 permitted_opens[idx].listen_port = fwd->listen_port;
3293 open_match(ForwardPermission *allowed_open, const char *requestedhost,
3296 if (allowed_open->host_to_connect == NULL)
3298 if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
3299 allowed_open->port_to_connect != requestedport)
3301 if (strcmp(allowed_open->host_to_connect, requestedhost) != 0)
3307 * Note that in the listen host/port case
3308 * we don't support FWD_PERMIT_ANY_PORT and
3309 * need to translate between the configured-host (listen_host)
3310 * and what we've sent to the remote server (channel_rfwd_bind_host)
3313 open_listen_match_tcpip(ForwardPermission *allowed_open,
3314 const char *requestedhost, u_short requestedport, int translate)
3316 const char *allowed_host;
3318 if (allowed_open->host_to_connect == NULL)
3320 if (allowed_open->listen_port != requestedport)
3322 if (!translate && allowed_open->listen_host == NULL &&
3323 requestedhost == NULL)
3325 allowed_host = translate ?
3326 channel_rfwd_bind_host(allowed_open->listen_host) :
3327 allowed_open->listen_host;
3328 if (allowed_host == NULL ||
3329 strcmp(allowed_host, requestedhost) != 0)
3335 open_listen_match_streamlocal(ForwardPermission *allowed_open,
3336 const char *requestedpath)
3338 if (allowed_open->host_to_connect == NULL)
3340 if (allowed_open->listen_port != PORT_STREAMLOCAL)
3342 if (allowed_open->listen_path == NULL ||
3343 strcmp(allowed_open->listen_path, requestedpath) != 0)
3349 * Request cancellation of remote forwarding of connection host:port from
3353 channel_request_rforward_cancel_tcpip(const char *host, u_short port)
3360 for (i = 0; i < num_permitted_opens; i++) {
3361 if (open_listen_match_tcpip(&permitted_opens[i], host, port, 0))
3364 if (i >= num_permitted_opens) {
3365 debug("%s: requested forward not found", __func__);
3368 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3369 packet_put_cstring("cancel-tcpip-forward");
3371 packet_put_cstring(channel_rfwd_bind_host(host));
3372 packet_put_int(port);
3375 permitted_opens[i].listen_port = 0;
3376 permitted_opens[i].port_to_connect = 0;
3377 free(permitted_opens[i].host_to_connect);
3378 permitted_opens[i].host_to_connect = NULL;
3379 free(permitted_opens[i].listen_host);
3380 permitted_opens[i].listen_host = NULL;
3381 permitted_opens[i].listen_path = NULL;
3387 * Request cancellation of remote forwarding of Unix domain socket
3388 * path from local side.
3391 channel_request_rforward_cancel_streamlocal(const char *path)
3398 for (i = 0; i < num_permitted_opens; i++) {
3399 if (open_listen_match_streamlocal(&permitted_opens[i], path))
3402 if (i >= num_permitted_opens) {
3403 debug("%s: requested forward not found", __func__);
3406 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3407 packet_put_cstring("cancel-streamlocal-forward@openssh.com");
3409 packet_put_cstring(path);
3412 permitted_opens[i].listen_port = 0;
3413 permitted_opens[i].port_to_connect = 0;
3414 free(permitted_opens[i].host_to_connect);
3415 permitted_opens[i].host_to_connect = NULL;
3416 permitted_opens[i].listen_host = NULL;
3417 free(permitted_opens[i].listen_path);
3418 permitted_opens[i].listen_path = NULL;
3424 * Request cancellation of remote forwarding of a connection from local side.
3427 channel_request_rforward_cancel(struct Forward *fwd)
3429 if (fwd->listen_path != NULL) {
3430 return (channel_request_rforward_cancel_streamlocal(
3433 return (channel_request_rforward_cancel_tcpip(fwd->listen_host,
3434 fwd->listen_port ? fwd->listen_port : fwd->allocated_port));
3439 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3440 * listening for the port, and sends back a success reply (or disconnect
3441 * message if there was an error).
3444 channel_input_port_forward_request(int is_root, struct ForwardOptions *fwd_opts)
3449 /* Get arguments from the packet. */
3450 memset(&fwd, 0, sizeof(fwd));
3451 fwd.listen_port = packet_get_int();
3452 fwd.connect_host = packet_get_string(NULL);
3453 fwd.connect_port = packet_get_int();
3457 * Check that an unprivileged user is not trying to forward a
3460 if (fwd.listen_port < IPPORT_RESERVED && !is_root)
3462 "Requested forwarding of port %d but user is not root.",
3464 if (fwd.connect_port == 0)
3465 packet_disconnect("Dynamic forwarding denied.");
3468 /* Initiate forwarding */
3469 success = channel_setup_local_fwd_listener(&fwd, fwd_opts);
3471 /* Free the argument string. */
3472 free(fwd.connect_host);
3474 return (success ? 0 : -1);
3478 * Permits opening to any host/port if permitted_opens[] is empty. This is
3479 * usually called by the server, because the user could connect to any port
3480 * anyway, and the server has no way to know but to trust the client anyway.
3483 channel_permit_all_opens(void)
3485 if (num_permitted_opens == 0)
3486 all_opens_permitted = 1;
3490 channel_add_permitted_opens(char *host, int port)
3492 debug("allow port forwarding to host %s port %d", host, port);
3494 permitted_opens = xreallocarray(permitted_opens,
3495 num_permitted_opens + 1, sizeof(*permitted_opens));
3496 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3497 permitted_opens[num_permitted_opens].port_to_connect = port;
3498 permitted_opens[num_permitted_opens].listen_host = NULL;
3499 permitted_opens[num_permitted_opens].listen_path = NULL;
3500 permitted_opens[num_permitted_opens].listen_port = 0;
3501 num_permitted_opens++;
3503 all_opens_permitted = 0;
3507 * Update the listen port for a dynamic remote forward, after
3508 * the actual 'newport' has been allocated. If 'newport' < 0 is
3509 * passed then they entry will be invalidated.
3512 channel_update_permitted_opens(int idx, int newport)
3514 if (idx < 0 || idx >= num_permitted_opens) {
3515 debug("channel_update_permitted_opens: index out of range:"
3516 " %d num_permitted_opens %d", idx, num_permitted_opens);
3519 debug("%s allowed port %d for forwarding to host %s port %d",
3520 newport > 0 ? "Updating" : "Removing",
3522 permitted_opens[idx].host_to_connect,
3523 permitted_opens[idx].port_to_connect);
3525 permitted_opens[idx].listen_port =
3526 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3528 permitted_opens[idx].listen_port = 0;
3529 permitted_opens[idx].port_to_connect = 0;
3530 free(permitted_opens[idx].host_to_connect);
3531 permitted_opens[idx].host_to_connect = NULL;
3532 free(permitted_opens[idx].listen_host);
3533 permitted_opens[idx].listen_host = NULL;
3534 free(permitted_opens[idx].listen_path);
3535 permitted_opens[idx].listen_path = NULL;
3540 channel_add_adm_permitted_opens(char *host, int port)
3542 debug("config allows port forwarding to host %s port %d", host, port);
3544 permitted_adm_opens = xreallocarray(permitted_adm_opens,
3545 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3546 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3548 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3549 permitted_adm_opens[num_adm_permitted_opens].listen_host = NULL;
3550 permitted_adm_opens[num_adm_permitted_opens].listen_path = NULL;
3551 permitted_adm_opens[num_adm_permitted_opens].listen_port = 0;
3552 return ++num_adm_permitted_opens;
3556 channel_disable_adm_local_opens(void)
3558 channel_clear_adm_permitted_opens();
3559 permitted_adm_opens = xcalloc(sizeof(*permitted_adm_opens), 1);
3560 permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3561 num_adm_permitted_opens = 1;
3565 channel_clear_permitted_opens(void)
3569 for (i = 0; i < num_permitted_opens; i++) {
3570 free(permitted_opens[i].host_to_connect);
3571 free(permitted_opens[i].listen_host);
3572 free(permitted_opens[i].listen_path);
3574 free(permitted_opens);
3575 permitted_opens = NULL;
3576 num_permitted_opens = 0;
3580 channel_clear_adm_permitted_opens(void)
3584 for (i = 0; i < num_adm_permitted_opens; i++) {
3585 free(permitted_adm_opens[i].host_to_connect);
3586 free(permitted_adm_opens[i].listen_host);
3587 free(permitted_adm_opens[i].listen_path);
3589 free(permitted_adm_opens);
3590 permitted_adm_opens = NULL;
3591 num_adm_permitted_opens = 0;
3595 channel_print_adm_permitted_opens(void)
3599 printf("permitopen");
3600 if (num_adm_permitted_opens == 0) {
3604 for (i = 0; i < num_adm_permitted_opens; i++)
3605 if (permitted_adm_opens[i].host_to_connect == NULL)
3608 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3609 permitted_adm_opens[i].port_to_connect);
3613 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3615 permitopen_port(const char *p)
3619 if (strcmp(p, "*") == 0)
3620 return FWD_PERMIT_ANY_PORT;
3621 if ((port = a2port(p)) > 0)
3626 /* Try to start non-blocking connect to next host in cctx list */
3628 connect_next(struct channel_connect *cctx)
3630 int sock, saved_errno;
3631 struct sockaddr_un *sunaddr;
3632 char ntop[NI_MAXHOST], strport[MAX(NI_MAXSERV,sizeof(sunaddr->sun_path))];
3634 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3635 switch (cctx->ai->ai_family) {
3637 /* unix:pathname instead of host:port */
3638 sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
3639 strlcpy(ntop, "unix", sizeof(ntop));
3640 strlcpy(strport, sunaddr->sun_path, sizeof(strport));
3644 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3645 ntop, sizeof(ntop), strport, sizeof(strport),
3646 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3647 error("connect_next: getnameinfo failed");
3654 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3655 cctx->ai->ai_protocol)) == -1) {
3656 if (cctx->ai->ai_next == NULL)
3657 error("socket: %.100s", strerror(errno));
3659 verbose("socket: %.100s", strerror(errno));
3662 if (set_nonblock(sock) == -1)
3663 fatal("%s: set_nonblock(%d)", __func__, sock);
3664 if (connect(sock, cctx->ai->ai_addr,
3665 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3666 debug("connect_next: host %.100s ([%.100s]:%s): "
3667 "%.100s", cctx->host, ntop, strport,
3669 saved_errno = errno;
3671 errno = saved_errno;
3672 continue; /* fail -- try next */
3674 if (cctx->ai->ai_family != AF_UNIX)
3676 debug("connect_next: host %.100s ([%.100s]:%s) "
3677 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3678 cctx->ai = cctx->ai->ai_next;
3685 channel_connect_ctx_free(struct channel_connect *cctx)
3689 if (cctx->aitop->ai_family == AF_UNIX)
3692 freeaddrinfo(cctx->aitop);
3694 memset(cctx, 0, sizeof(*cctx));
3697 /* Return CONNECTING channel to remote host:port or local socket path */
3699 connect_to(const char *name, int port, char *ctype, char *rname)
3701 struct addrinfo hints;
3704 char strport[NI_MAXSERV];
3705 struct channel_connect cctx;
3708 memset(&cctx, 0, sizeof(cctx));
3710 if (port == PORT_STREAMLOCAL) {
3711 struct sockaddr_un *sunaddr;
3712 struct addrinfo *ai;
3714 if (strlen(name) > sizeof(sunaddr->sun_path)) {
3715 error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
3720 * Fake up a struct addrinfo for AF_UNIX connections.
3721 * channel_connect_ctx_free() must check ai_family
3722 * and use free() not freeaddirinfo() for AF_UNIX.
3724 ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
3725 memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
3726 ai->ai_addr = (struct sockaddr *)(ai + 1);
3727 ai->ai_addrlen = sizeof(*sunaddr);
3728 ai->ai_family = AF_UNIX;
3729 ai->ai_socktype = SOCK_STREAM;
3730 ai->ai_protocol = PF_UNSPEC;
3731 sunaddr = (struct sockaddr_un *)ai->ai_addr;
3732 sunaddr->sun_family = AF_UNIX;
3733 strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
3736 memset(&hints, 0, sizeof(hints));
3737 hints.ai_family = IPv4or6;
3738 hints.ai_socktype = SOCK_STREAM;
3739 snprintf(strport, sizeof strport, "%d", port);
3740 if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop)) != 0) {
3741 error("connect_to %.100s: unknown host (%s)", name,
3742 ssh_gai_strerror(gaierr));
3747 cctx.host = xstrdup(name);
3749 cctx.ai = cctx.aitop;
3751 if ((sock = connect_next(&cctx)) == -1) {
3752 error("connect to %.100s port %d failed: %s",
3753 name, port, strerror(errno));
3754 channel_connect_ctx_free(&cctx);
3757 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3758 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3759 c->connect_ctx = cctx;
3764 channel_connect_by_listen_address(const char *listen_host,
3765 u_short listen_port, char *ctype, char *rname)
3769 for (i = 0; i < num_permitted_opens; i++) {
3770 if (open_listen_match_tcpip(&permitted_opens[i], listen_host,
3773 permitted_opens[i].host_to_connect,
3774 permitted_opens[i].port_to_connect, ctype, rname);
3777 error("WARNING: Server requests forwarding for unknown listen_port %d",
3783 channel_connect_by_listen_path(const char *path, char *ctype, char *rname)
3787 for (i = 0; i < num_permitted_opens; i++) {
3788 if (open_listen_match_streamlocal(&permitted_opens[i], path)) {
3790 permitted_opens[i].host_to_connect,
3791 permitted_opens[i].port_to_connect, ctype, rname);
3794 error("WARNING: Server requests forwarding for unknown path %.100s",
3799 /* Check if connecting to that port is permitted and connect. */
3801 channel_connect_to_port(const char *host, u_short port, char *ctype, char *rname)
3803 int i, permit, permit_adm = 1;
3805 permit = all_opens_permitted;
3807 for (i = 0; i < num_permitted_opens; i++)
3808 if (open_match(&permitted_opens[i], host, port)) {
3814 if (num_adm_permitted_opens > 0) {
3816 for (i = 0; i < num_adm_permitted_opens; i++)
3817 if (open_match(&permitted_adm_opens[i], host, port)) {
3823 if (!permit || !permit_adm) {
3824 logit("Received request to connect to host %.100s port %d, "
3825 "but the request was denied.", host, port);
3828 return connect_to(host, port, ctype, rname);
3831 /* Check if connecting to that path is permitted and connect. */
3833 channel_connect_to_path(const char *path, char *ctype, char *rname)
3835 int i, permit, permit_adm = 1;
3837 permit = all_opens_permitted;
3839 for (i = 0; i < num_permitted_opens; i++)
3840 if (open_match(&permitted_opens[i], path, PORT_STREAMLOCAL)) {
3846 if (num_adm_permitted_opens > 0) {
3848 for (i = 0; i < num_adm_permitted_opens; i++)
3849 if (open_match(&permitted_adm_opens[i], path, PORT_STREAMLOCAL)) {
3855 if (!permit || !permit_adm) {
3856 logit("Received request to connect to path %.100s, "
3857 "but the request was denied.", path);
3860 return connect_to(path, PORT_STREAMLOCAL, ctype, rname);
3864 channel_send_window_changes(void)
3869 for (i = 0; i < channels_alloc; i++) {
3870 if (channels[i] == NULL || !channels[i]->client_tty ||
3871 channels[i]->type != SSH_CHANNEL_OPEN)
3873 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3875 channel_request_start(i, "window-change", 0);
3876 packet_put_int((u_int)ws.ws_col);
3877 packet_put_int((u_int)ws.ws_row);
3878 packet_put_int((u_int)ws.ws_xpixel);
3879 packet_put_int((u_int)ws.ws_ypixel);
3884 /* -- X11 forwarding */
3887 * Creates an internet domain socket for listening for X11 connections.
3888 * Returns 0 and a suitable display number for the DISPLAY variable
3889 * stored in display_numberp , or -1 if an error occurs.
3892 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3893 int single_connection, u_int *display_numberp, int **chanids)
3896 int display_number, sock;
3898 struct addrinfo hints, *ai, *aitop;
3899 char strport[NI_MAXSERV];
3900 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3902 if (chanids == NULL)
3905 for (display_number = x11_display_offset;
3906 display_number < MAX_DISPLAYS;
3908 port = 6000 + display_number;
3909 memset(&hints, 0, sizeof(hints));
3910 hints.ai_family = IPv4or6;
3911 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3912 hints.ai_socktype = SOCK_STREAM;
3913 snprintf(strport, sizeof strport, "%d", port);
3914 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3915 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3918 for (ai = aitop; ai; ai = ai->ai_next) {
3919 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3921 sock = socket(ai->ai_family, ai->ai_socktype,
3924 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3926 && (errno != EPFNOSUPPORT)
3929 error("socket: %.100s", strerror(errno));
3930 freeaddrinfo(aitop);
3933 debug("x11_create_display_inet: Socket family %d not supported",
3938 if (ai->ai_family == AF_INET6)
3939 sock_set_v6only(sock);
3940 if (x11_use_localhost)
3941 channel_set_reuseaddr(sock);
3942 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3943 debug2("bind port %d: %.100s", port, strerror(errno));
3946 for (n = 0; n < num_socks; n++) {
3952 socks[num_socks++] = sock;
3953 if (num_socks == NUM_SOCKS)
3956 freeaddrinfo(aitop);
3960 if (display_number >= MAX_DISPLAYS) {
3961 error("Failed to allocate internet-domain X11 display socket.");
3964 /* Start listening for connections on the socket. */
3965 for (n = 0; n < num_socks; n++) {
3967 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3968 error("listen: %.100s", strerror(errno));
3974 /* Allocate a channel for each socket. */
3975 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3976 for (n = 0; n < num_socks; n++) {
3978 nc = channel_new("x11 listener",
3979 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3980 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3981 0, "X11 inet listener", 1);
3982 nc->single_connection = single_connection;
3983 (*chanids)[n] = nc->self;
3987 /* Return the display number for the DISPLAY environment variable. */
3988 *display_numberp = display_number;
3993 connect_local_xsocket_path(const char *pathname)
3996 struct sockaddr_un addr;
3998 sock = socket(AF_UNIX, SOCK_STREAM, 0);
4000 error("socket: %.100s", strerror(errno));
4001 memset(&addr, 0, sizeof(addr));
4002 addr.sun_family = AF_UNIX;
4003 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
4004 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
4007 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
4012 connect_local_xsocket(u_int dnr)
4015 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
4016 return connect_local_xsocket_path(buf);
4020 x11_connect_display(void)
4022 u_int display_number;
4023 const char *display;
4024 char buf[1024], *cp;
4025 struct addrinfo hints, *ai, *aitop;
4026 char strport[NI_MAXSERV];
4027 int gaierr, sock = 0;
4029 /* Try to open a socket for the local X server. */
4030 display = getenv("DISPLAY");
4032 error("DISPLAY not set.");
4036 * Now we decode the value of the DISPLAY variable and make a
4037 * connection to the real X server.
4040 /* Check if the display is from launchd. */
4042 if (strncmp(display, "/tmp/launch", 11) == 0) {
4043 sock = connect_local_xsocket_path(display);
4047 /* OK, we now have a connection to the display. */
4052 * Check if it is a unix domain socket. Unix domain displays are in
4053 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
4055 if (strncmp(display, "unix:", 5) == 0 ||
4056 display[0] == ':') {
4057 /* Connect to the unix domain socket. */
4058 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
4059 error("Could not parse display number from DISPLAY: %.100s",
4063 /* Create a socket. */
4064 sock = connect_local_xsocket(display_number);
4068 /* OK, we now have a connection to the display. */
4072 * Connect to an inet socket. The DISPLAY value is supposedly
4073 * hostname:d[.s], where hostname may also be numeric IP address.
4075 strlcpy(buf, display, sizeof(buf));
4076 cp = strchr(buf, ':');
4078 error("Could not find ':' in DISPLAY: %.100s", display);
4082 /* buf now contains the host name. But first we parse the display number. */
4083 if (sscanf(cp + 1, "%u", &display_number) != 1) {
4084 error("Could not parse display number from DISPLAY: %.100s",
4089 /* Look up the host address */
4090 memset(&hints, 0, sizeof(hints));
4091 hints.ai_family = IPv4or6;
4092 hints.ai_socktype = SOCK_STREAM;
4093 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
4094 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
4095 error("%.100s: unknown host. (%s)", buf,
4096 ssh_gai_strerror(gaierr));
4099 for (ai = aitop; ai; ai = ai->ai_next) {
4100 /* Create a socket. */
4101 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
4103 debug2("socket: %.100s", strerror(errno));
4106 /* Connect it to the display. */
4107 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4108 debug2("connect %.100s port %u: %.100s", buf,
4109 6000 + display_number, strerror(errno));
4116 freeaddrinfo(aitop);
4118 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
4127 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
4128 * the remote channel number. We should do whatever we want, and respond
4129 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
4134 x11_input_open(int type, u_int32_t seq, void *ctxt)
4137 int remote_id, sock = 0;
4140 debug("Received X11 open request.");
4142 remote_id = packet_get_int();
4144 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
4145 remote_host = packet_get_string(NULL);
4147 remote_host = xstrdup("unknown (remote did not supply name)");
4151 /* Obtain a connection to the real X display. */
4152 sock = x11_connect_display();
4154 /* Allocate a channel for this connection. */
4155 c = channel_new("connected x11 socket",
4156 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
4158 c->remote_id = remote_id;
4163 /* Send refusal to the remote host. */
4164 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
4165 packet_put_int(remote_id);
4167 /* Send a confirmation to the remote host. */
4168 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
4169 packet_put_int(remote_id);
4170 packet_put_int(c->self);
4176 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
4179 deny_input_open(int type, u_int32_t seq, void *ctxt)
4181 int rchan = packet_get_int();
4184 case SSH_SMSG_AGENT_OPEN:
4185 error("Warning: ssh server tried agent forwarding.");
4187 case SSH_SMSG_X11_OPEN:
4188 error("Warning: ssh server tried X11 forwarding.");
4191 error("deny_input_open: type %d", type);
4194 error("Warning: this is probably a break-in attempt by a malicious server.");
4195 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
4196 packet_put_int(rchan);
4202 * Requests forwarding of X11 connections, generates fake authentication
4203 * data, and enables authentication spoofing.
4204 * This should be called in the client only.
4207 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
4208 const char *proto, const char *data, int want_reply)
4210 u_int data_len = (u_int) strlen(data) / 2;
4217 if (x11_saved_display == NULL)
4218 x11_saved_display = xstrdup(disp);
4219 else if (strcmp(disp, x11_saved_display) != 0) {
4220 error("x11_request_forwarding_with_spoofing: different "
4221 "$DISPLAY already forwarded");
4225 cp = strchr(disp, ':');
4227 cp = strchr(cp, '.');
4229 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
4233 if (x11_saved_proto == NULL) {
4234 /* Save protocol name. */
4235 x11_saved_proto = xstrdup(proto);
4237 * Extract real authentication data and generate fake data
4238 * of the same length.
4240 x11_saved_data = xmalloc(data_len);
4241 x11_fake_data = xmalloc(data_len);
4242 for (i = 0; i < data_len; i++) {
4243 if (sscanf(data + 2 * i, "%2x", &value) != 1)
4244 fatal("x11_request_forwarding: bad "
4245 "authentication data: %.100s", data);
4248 x11_saved_data[i] = value;
4249 x11_fake_data[i] = rnd & 0xff;
4252 x11_saved_data_len = data_len;
4253 x11_fake_data_len = data_len;
4256 /* Convert the fake data into hex. */
4257 new_data = tohex(x11_fake_data, data_len);
4259 /* Send the request packet. */
4261 channel_request_start(client_session_id, "x11-req", want_reply);
4262 packet_put_char(0); /* XXX bool single connection */
4264 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
4266 packet_put_cstring(proto);
4267 packet_put_cstring(new_data);
4268 packet_put_int(screen_number);
4270 packet_write_wait();
4275 /* -- agent forwarding */
4277 /* Sends a message to the server to request authentication fd forwarding. */
4280 auth_request_forwarding(void)
4282 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
4284 packet_write_wait();