2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * This file contains functions for generic socket connection forwarding.
6 * There is also code for initiating connection forwarding for X11 connections,
7 * arbitrary tcp/ip connections, and the authentication agent connection.
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 support added by Markus Friedl.
17 * Copyright (c) 1999,2000 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.
43 RCSID("$OpenBSD: channels.c,v 1.112 2001/05/04 14:34:34 markus Exp $");
45 #include <openssl/rsa.h>
46 #include <openssl/dsa.h>
65 /* Maximum number of fake X11 displays to try. */
66 #define MAX_DISPLAYS 1000
68 /* Max len of agent socket */
69 #define MAX_SOCKET_NAME 100
72 * Pointer to an array containing all allocated channels. The array is
73 * dynamically extended as needed.
75 static Channel *channels = NULL;
78 * Size of the channel array. All slots of the array must always be
79 * initialized (at least the type field); unused slots are marked with type
82 static int channels_alloc = 0;
85 * Maximum file descriptor value used in any of the channels. This is
86 * updated in channel_allocate.
88 static int channel_max_fd = 0;
90 /* Name and directory of socket for authentication agent forwarding. */
91 static char *channel_forwarded_auth_socket_name = NULL;
92 static char *channel_forwarded_auth_socket_dir = NULL;
94 /* Saved X11 authentication protocol name. */
95 char *x11_saved_proto = NULL;
97 /* Saved X11 authentication data. This is the real data. */
98 char *x11_saved_data = NULL;
99 u_int x11_saved_data_len = 0;
102 * Fake X11 authentication data. This is what the server will be sending us;
103 * we should replace any occurrences of this by the real data.
105 char *x11_fake_data = NULL;
106 u_int x11_fake_data_len;
109 * Data structure for storing which hosts are permitted for forward requests.
110 * The local sides of any remote forwards are stored in this array to prevent
111 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
112 * network (which might be behind a firewall).
115 char *host_to_connect; /* Connect to 'host'. */
116 u_short port_to_connect; /* Connect to 'port'. */
117 u_short listen_port; /* Remote side should listen port number. */
120 /* List of all permitted host/port pairs to connect. */
121 static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
122 /* Number of permitted host/port pairs in the array. */
123 static int num_permitted_opens = 0;
125 * If this is true, all opens are permitted. This is the case on the server
126 * on which we have to trust the client anyway, and the user could do
127 * anything after logging in anyway.
129 static int all_opens_permitted = 0;
131 /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
132 static int have_hostname_in_open = 0;
134 /* AF_UNSPEC or AF_INET or AF_INET6 */
137 void port_open_helper(Channel *c, char *rtype);
139 /* Sets specific protocol options. */
142 channel_set_options(int hostname_in_open)
144 have_hostname_in_open = hostname_in_open;
147 /* lookup channel by id */
150 channel_lookup(int id)
153 if (id < 0 || id > channels_alloc) {
154 log("channel_lookup: %d: bad id", id);
158 if (c->type == SSH_CHANNEL_FREE) {
159 log("channel_lookup: %d: bad id: channel free", id);
166 * Register filedescriptors for a channel, used when allocating a channel or
167 * when the channel consumer/producer is ready, e.g. shell exec'd
171 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
172 int extusage, int nonblock)
174 /* Update the maximum file descriptor value. */
175 channel_max_fd = MAX(channel_max_fd, rfd);
176 channel_max_fd = MAX(channel_max_fd, wfd);
177 channel_max_fd = MAX(channel_max_fd, efd);
179 /* XXX set close-on-exec -markus */
183 c->sock = (rfd == wfd) ? rfd : -1;
185 c->extended_usage = extusage;
187 /* XXX ugly hack: nonblock is only set by the server */
188 if (nonblock && isatty(c->rfd)) {
189 debug("channel %d: rfd %d isatty", c->self, c->rfd);
191 if (!isatty(c->wfd)) {
192 error("channel %d: wfd %d is not a tty?",
199 /* enable nonblocking mode */
211 * Allocate a new channel object and set its type and socket. This will cause
212 * remote_name to be freed.
216 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
217 int window, int maxpack, int extusage, char *remote_name, int nonblock)
222 /* Do initial allocation if this is the first call. */
223 if (channels_alloc == 0) {
226 channels = xmalloc(channels_alloc * sizeof(Channel));
227 for (i = 0; i < channels_alloc; i++)
228 channels[i].type = SSH_CHANNEL_FREE;
230 * Kludge: arrange a call to channel_stop_listening if we
231 * terminate with fatal().
233 fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
235 /* Try to find a free slot where to put the new channel. */
236 for (found = -1, i = 0; i < channels_alloc; i++)
237 if (channels[i].type == SSH_CHANNEL_FREE) {
238 /* Found a free slot. */
243 /* There are no free slots. Take last+1 slot and expand the array. */
244 found = channels_alloc;
245 channels_alloc += 10;
246 debug2("channel: expanding %d", channels_alloc);
247 channels = xrealloc(channels, channels_alloc * sizeof(Channel));
248 for (i = found; i < channels_alloc; i++)
249 channels[i].type = SSH_CHANNEL_FREE;
251 /* Initialize and return new channel number. */
252 c = &channels[found];
253 buffer_init(&c->input);
254 buffer_init(&c->output);
255 buffer_init(&c->extended);
256 chan_init_iostates(c);
257 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
261 c->local_window = window;
262 c->local_window_max = window;
263 c->local_consumed = 0;
264 c->local_maxpacket = maxpack;
266 c->remote_name = remote_name;
267 c->remote_window = 0;
268 c->remote_maxpacket = 0;
272 c->dettach_user = NULL;
273 c->input_filter = NULL;
274 debug("channel %d: new [%s]", found, remote_name);
277 /* old interface XXX */
279 channel_allocate(int type, int sock, char *remote_name)
281 return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
285 /* Close all channel fd/socket. */
288 channel_close_fds(Channel *c)
308 /* Free the channel and close its fd/socket. */
313 Channel *c = channel_lookup(id);
314 char *s = channel_open_message();
317 packet_disconnect("channel free: bad local channel %d", id);
318 debug("channel_free: channel %d: status: %s", id, s);
321 if (c->dettach_user != NULL) {
322 debug("channel_free: channel %d: dettaching channel user", id);
323 c->dettach_user(c->self, NULL);
326 shutdown(c->sock, SHUT_RDWR);
327 channel_close_fds(c);
328 buffer_free(&c->input);
329 buffer_free(&c->output);
330 buffer_free(&c->extended);
331 c->type = SSH_CHANNEL_FREE;
332 if (c->remote_name) {
333 xfree(c->remote_name);
334 c->remote_name = NULL;
339 * 'channel_pre*' are called just before select() to add any bits relevant to
340 * channels in the select bitmasks.
343 * 'channel_post*': perform any appropriate operations for channels which
344 * have events pending.
346 typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
347 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
348 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
351 channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
353 FD_SET(c->sock, readset);
357 channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
359 debug3("channel %d: waiting for connection", c->self);
360 FD_SET(c->sock, writeset);
364 channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
366 if (buffer_len(&c->input) < packet_get_maxsize())
367 FD_SET(c->sock, readset);
368 if (buffer_len(&c->output) > 0)
369 FD_SET(c->sock, writeset);
373 channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
375 /* test whether sockets are 'alive' for read/write */
376 if (c->istate == CHAN_INPUT_OPEN)
377 if (buffer_len(&c->input) < packet_get_maxsize())
378 FD_SET(c->sock, readset);
379 if (c->ostate == CHAN_OUTPUT_OPEN ||
380 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
381 if (buffer_len(&c->output) > 0) {
382 FD_SET(c->sock, writeset);
383 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
390 channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
392 if (c->istate == CHAN_INPUT_OPEN &&
393 c->remote_window > 0 &&
394 buffer_len(&c->input) < c->remote_window)
395 FD_SET(c->rfd, readset);
396 if (c->ostate == CHAN_OUTPUT_OPEN ||
397 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
398 if (buffer_len(&c->output) > 0) {
399 FD_SET(c->wfd, writeset);
400 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
404 /** XXX check close conditions, too */
406 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
407 buffer_len(&c->extended) > 0)
408 FD_SET(c->efd, writeset);
409 else if (c->extended_usage == CHAN_EXTENDED_READ &&
410 buffer_len(&c->extended) < c->remote_window)
411 FD_SET(c->efd, readset);
416 channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
418 if (buffer_len(&c->input) == 0) {
419 packet_start(SSH_MSG_CHANNEL_CLOSE);
420 packet_put_int(c->remote_id);
422 c->type = SSH_CHANNEL_CLOSED;
423 debug("channel %d: closing after input drain.", c->self);
428 channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
430 if (buffer_len(&c->output) == 0)
431 channel_free(c->self);
433 FD_SET(c->sock, writeset);
437 * This is a special state for X11 authentication spoofing. An opened X11
438 * connection (when authentication spoofing is being done) remains in this
439 * state until the first packet has been completely read. The authentication
440 * data in that packet is then substituted by the real data if it matches the
441 * fake data, and the channel is put into normal mode.
442 * XXX All this happens at the client side.
445 x11_open_helper(Channel *c)
448 u_int proto_len, data_len;
450 /* Check if the fixed size part of the packet is in buffer. */
451 if (buffer_len(&c->output) < 12)
454 /* Parse the lengths of variable-length fields. */
455 ucp = (u_char *) buffer_ptr(&c->output);
456 if (ucp[0] == 0x42) { /* Byte order MSB first. */
457 proto_len = 256 * ucp[6] + ucp[7];
458 data_len = 256 * ucp[8] + ucp[9];
459 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
460 proto_len = ucp[6] + 256 * ucp[7];
461 data_len = ucp[8] + 256 * ucp[9];
463 debug("Initial X11 packet contains bad byte order byte: 0x%x",
468 /* Check if the whole packet is in buffer. */
469 if (buffer_len(&c->output) <
470 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
473 /* Check if authentication protocol matches. */
474 if (proto_len != strlen(x11_saved_proto) ||
475 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
476 debug("X11 connection uses different authentication protocol.");
479 /* Check if authentication data matches our fake data. */
480 if (data_len != x11_fake_data_len ||
481 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
482 x11_fake_data, x11_fake_data_len) != 0) {
483 debug("X11 auth data does not match fake data.");
486 /* Check fake data length */
487 if (x11_fake_data_len != x11_saved_data_len) {
488 error("X11 fake_data_len %d != saved_data_len %d",
489 x11_fake_data_len, x11_saved_data_len);
493 * Received authentication protocol and data match
494 * our fake data. Substitute the fake data with real
497 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
498 x11_saved_data, x11_saved_data_len);
503 channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
505 int ret = x11_open_helper(c);
507 /* Start normal processing for the channel. */
508 c->type = SSH_CHANNEL_OPEN;
509 channel_pre_open_13(c, readset, writeset);
510 } else if (ret == -1) {
512 * We have received an X11 connection that has bad
513 * authentication information.
515 log("X11 connection rejected because of wrong authentication.");
516 buffer_clear(&c->input);
517 buffer_clear(&c->output);
520 c->type = SSH_CHANNEL_CLOSED;
521 packet_start(SSH_MSG_CHANNEL_CLOSE);
522 packet_put_int(c->remote_id);
528 channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
530 int ret = x11_open_helper(c);
532 c->type = SSH_CHANNEL_OPEN;
534 channel_pre_open_20(c, readset, writeset);
536 channel_pre_open_15(c, readset, writeset);
537 } else if (ret == -1) {
538 debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
539 chan_read_failed(c); /** force close? */
540 chan_write_failed(c);
541 debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
545 /* try to decode a socks4 header */
547 channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
550 int len, have, i, found;
556 struct in_addr dest_addr;
559 debug2("channel %d: decode socks4", c->self);
561 have = buffer_len(&c->input);
562 len = sizeof(s4_req);
565 p = buffer_ptr(&c->input);
566 for (found = 0, i = len; i < have; i++) {
572 /* the peer is probably sending garbage */
573 debug("channel %d: decode socks4: too long",
580 buffer_get(&c->input, (char *)&s4_req.version, 1);
581 buffer_get(&c->input, (char *)&s4_req.command, 1);
582 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
583 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
584 have = buffer_len(&c->input);
585 p = buffer_ptr(&c->input);
587 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
589 fatal("channel %d: decode socks4: len %d > have %d",
591 strlcpy(username, p, sizeof(username));
592 buffer_consume(&c->input, len);
593 buffer_consume(&c->input, 1); /* trailing '\0' */
595 host = inet_ntoa(s4_req.dest_addr);
596 strlcpy(c->path, host, sizeof(c->path));
597 c->host_port = ntohs(s4_req.dest_port);
599 debug("channel %d: dynamic request: socks4 host %s port %u command %u",
600 c->self, host, c->host_port, s4_req.command);
602 if (s4_req.command != 1) {
603 debug("channel %d: cannot handle: socks4 cn %d",
604 c->self, s4_req.command);
607 s4_rsp.version = 0; /* vn: 0 for reply */
608 s4_rsp.command = 90; /* cd: req granted */
609 s4_rsp.dest_port = 0; /* ignored */
610 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
611 buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
615 /* dynamic port forwarding */
617 channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
622 have = buffer_len(&c->input);
624 debug2("channel %d: pre_dynamic: have %d", c->self, have);
625 /* buffer_dump(&c->input); */
626 /* check if the fixed size part of the packet is in buffer. */
629 FD_SET(c->sock, readset);
632 /* try to guess the protocol */
633 p = buffer_ptr(&c->input);
636 ret = channel_decode_socks4(c, readset, writeset);
643 channel_free(c->self);
644 } else if (ret == 0) {
645 debug2("channel %d: pre_dynamic: need more", c->self);
647 FD_SET(c->sock, readset);
649 /* switch to the next state */
650 c->type = SSH_CHANNEL_OPENING;
651 port_open_helper(c, "direct-tcpip");
655 /* This is our fake X11 server socket. */
657 channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
659 struct sockaddr addr;
660 int newsock, newch, oldch;
662 char buf[16384], *remote_ipaddr;
665 if (FD_ISSET(c->sock, readset)) {
666 debug("X11 connection requested.");
667 addrlen = sizeof(addr);
668 newsock = accept(c->sock, &addr, &addrlen);
670 error("accept: %.100s", strerror(errno));
673 remote_ipaddr = get_peer_ipaddr(newsock);
674 remote_port = get_peer_port(newsock);
675 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
676 remote_ipaddr, remote_port);
679 newch = channel_new("x11",
680 SSH_CHANNEL_OPENING, newsock, newsock, -1,
681 c->local_window_max, c->local_maxpacket,
683 c = channel_lookup(oldch);
685 packet_start(SSH2_MSG_CHANNEL_OPEN);
686 packet_put_cstring("x11");
687 packet_put_int(newch);
688 packet_put_int(c->local_window_max);
689 packet_put_int(c->local_maxpacket);
690 /* originator ipaddr and port */
691 packet_put_cstring(remote_ipaddr);
692 if (datafellows & SSH_BUG_X11FWD) {
693 debug("ssh2 x11 bug compat mode");
695 packet_put_int(remote_port);
699 packet_start(SSH_SMSG_X11_OPEN);
700 packet_put_int(newch);
701 if (have_hostname_in_open)
702 packet_put_string(buf, strlen(buf));
705 xfree(remote_ipaddr);
710 port_open_helper(Channel *c, char *rtype)
714 char *remote_ipaddr = get_peer_ipaddr(c->sock);
715 u_short remote_port = get_peer_port(c->sock);
717 direct = (strcmp(rtype, "direct-tcpip") == 0);
719 snprintf(buf, sizeof buf,
720 "%s: listening port %d for %.100s port %d, "
721 "connect from %.200s port %d",
722 rtype, c->listening_port, c->path, c->host_port,
723 remote_ipaddr, remote_port);
725 xfree(c->remote_name);
726 c->remote_name = xstrdup(buf);
729 packet_start(SSH2_MSG_CHANNEL_OPEN);
730 packet_put_cstring(rtype);
731 packet_put_int(c->self);
732 packet_put_int(c->local_window_max);
733 packet_put_int(c->local_maxpacket);
735 /* target host, port */
736 packet_put_cstring(c->path);
737 packet_put_int(c->host_port);
739 /* listen address, port */
740 packet_put_cstring(c->path);
741 packet_put_int(c->listening_port);
743 /* originator host and port */
744 packet_put_cstring(remote_ipaddr);
745 packet_put_int(remote_port);
748 packet_start(SSH_MSG_PORT_OPEN);
749 packet_put_int(c->self);
750 packet_put_cstring(c->path);
751 packet_put_int(c->host_port);
752 if (have_hostname_in_open)
753 packet_put_cstring(c->remote_name);
756 xfree(remote_ipaddr);
760 * This socket is listening for connections to a forwarded TCP/IP port.
763 channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
766 struct sockaddr addr;
767 int newsock, newch, nextstate, oldch;
771 if (FD_ISSET(c->sock, readset)) {
772 debug("Connection to port %d forwarding "
773 "to %.100s port %d requested.",
774 c->listening_port, c->path, c->host_port);
776 rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
777 "forwarded-tcpip" : "direct-tcpip";
778 nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :
781 addrlen = sizeof(addr);
782 newsock = accept(c->sock, &addr, &addrlen);
784 error("accept: %.100s", strerror(errno));
788 newch = channel_new(rtype,
789 nextstate, newsock, newsock, -1,
790 c->local_window_max, c->local_maxpacket,
791 0, xstrdup(rtype), 1);
793 c = channel_lookup(oldch);
794 nc = channel_lookup(newch);
796 error("xxx: no new channel:");
799 nc->listening_port = c->listening_port;
800 nc->host_port = c->host_port;
801 strlcpy(nc->path, c->path, sizeof(nc->path));
803 if (nextstate != SSH_CHANNEL_DYNAMIC)
804 port_open_helper(nc, rtype);
809 * This is the authentication agent socket listening for connections from
813 channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
815 struct sockaddr addr;
816 int newsock, newch, oldch;
819 if (FD_ISSET(c->sock, readset)) {
820 addrlen = sizeof(addr);
821 newsock = accept(c->sock, &addr, &addrlen);
823 error("accept from auth socket: %.100s", strerror(errno));
827 newch = channel_new("accepted auth socket",
828 SSH_CHANNEL_OPENING, newsock, newsock, -1,
829 c->local_window_max, c->local_maxpacket,
830 0, xstrdup("accepted auth socket"), 1);
831 c = channel_lookup(oldch);
833 packet_start(SSH2_MSG_CHANNEL_OPEN);
834 packet_put_cstring("auth-agent@openssh.com");
835 packet_put_int(newch);
836 packet_put_int(c->local_window_max);
837 packet_put_int(c->local_maxpacket);
839 packet_start(SSH_SMSG_AGENT_OPEN);
840 packet_put_int(newch);
847 channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
849 if (FD_ISSET(c->sock, writeset)) {
851 int sz = sizeof(err);
852 c->type = SSH_CHANNEL_OPEN;
853 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
854 debug("getsockopt SO_ERROR failed");
857 debug("channel %d: connected", c->self);
859 debug("channel %d: not connected: %s",
860 c->self, strerror(err));
862 chan_write_failed(c);
869 channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
875 FD_ISSET(c->rfd, readset)) {
876 len = read(c->rfd, buf, sizeof(buf));
877 if (len < 0 && (errno == EINTR || errno == EAGAIN))
880 debug("channel %d: read<=0 rfd %d len %d",
881 c->self, c->rfd, len);
882 if (c->type != SSH_CHANNEL_OPEN) {
883 debug("channel %d: not open", c->self);
884 channel_free(c->self);
886 } else if (compat13) {
887 buffer_consume(&c->output, buffer_len(&c->output));
888 c->type = SSH_CHANNEL_INPUT_DRAINING;
889 debug("channel %d: status set to input draining.", c->self);
895 if(c->input_filter != NULL) {
896 if (c->input_filter(c, buf, len) == -1) {
897 debug("channel %d: filter stops", c->self);
901 buffer_append(&c->input, buf, len);
907 channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
912 /* Send buffered output data to the socket. */
914 FD_ISSET(c->wfd, writeset) &&
915 buffer_len(&c->output) > 0) {
916 len = write(c->wfd, buffer_ptr(&c->output),
917 buffer_len(&c->output));
918 if (len < 0 && (errno == EINTR || errno == EAGAIN))
921 if (c->type != SSH_CHANNEL_OPEN) {
922 debug("channel %d: not open", c->self);
923 channel_free(c->self);
925 } else if (compat13) {
926 buffer_consume(&c->output, buffer_len(&c->output));
927 debug("channel %d: status set to input draining.", c->self);
928 c->type = SSH_CHANNEL_INPUT_DRAINING;
930 chan_write_failed(c);
934 if (compat20 && c->isatty) {
935 if (tcgetattr(c->wfd, &tio) == 0 &&
936 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
938 * Simulate echo to reduce the impact of
939 * traffic analysis. We need to match the
940 * size of a SSH2_MSG_CHANNEL_DATA message
941 * (4 byte channel id + data)
943 packet_send_ignore(4 + len);
947 buffer_consume(&c->output, len);
948 if (compat20 && len > 0) {
949 c->local_consumed += len;
955 channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
960 /** XXX handle drain efd, too */
962 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
963 FD_ISSET(c->efd, writeset) &&
964 buffer_len(&c->extended) > 0) {
965 len = write(c->efd, buffer_ptr(&c->extended),
966 buffer_len(&c->extended));
967 debug2("channel %d: written %d to efd %d",
968 c->self, len, c->efd);
969 if (len < 0 && (errno == EINTR || errno == EAGAIN))
972 debug2("channel %d: closing write-efd %d",
977 buffer_consume(&c->extended, len);
978 c->local_consumed += len;
980 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
981 FD_ISSET(c->efd, readset)) {
982 len = read(c->efd, buf, sizeof(buf));
983 debug2("channel %d: read %d from efd %d",
984 c->self, len, c->efd);
985 if (len < 0 && (errno == EINTR || errno == EAGAIN))
988 debug2("channel %d: closing read-efd %d",
993 buffer_append(&c->extended, buf, len);
1000 channel_check_window(Channel *c)
1002 if (c->type == SSH_CHANNEL_OPEN &&
1003 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1004 c->local_window < c->local_window_max/2 &&
1005 c->local_consumed > 0) {
1006 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1007 packet_put_int(c->remote_id);
1008 packet_put_int(c->local_consumed);
1010 debug2("channel %d: window %d sent adjust %d",
1011 c->self, c->local_window,
1013 c->local_window += c->local_consumed;
1014 c->local_consumed = 0;
1020 channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1022 channel_handle_rfd(c, readset, writeset);
1023 channel_handle_wfd(c, readset, writeset);
1027 channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1029 channel_handle_rfd(c, readset, writeset);
1030 channel_handle_wfd(c, readset, writeset);
1031 channel_handle_efd(c, readset, writeset);
1033 channel_check_window(c);
1037 channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1040 /* Send buffered output data to the socket. */
1041 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1042 len = write(c->sock, buffer_ptr(&c->output),
1043 buffer_len(&c->output));
1045 buffer_consume(&c->output, buffer_len(&c->output));
1047 buffer_consume(&c->output, len);
1052 channel_handler_init_20(void)
1054 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1055 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1056 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1057 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1058 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1059 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1060 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1061 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1063 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1064 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1065 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1066 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1067 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1068 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1069 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1073 channel_handler_init_13(void)
1075 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1076 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1077 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1078 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1079 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1080 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1081 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1082 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1083 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1085 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1086 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1087 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1088 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1089 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1090 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1091 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1095 channel_handler_init_15(void)
1097 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1098 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1099 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1100 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1101 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1102 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1103 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1105 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1106 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1107 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1108 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1109 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1110 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1114 channel_handler_init(void)
1117 for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1118 channel_pre[i] = NULL;
1119 channel_post[i] = NULL;
1122 channel_handler_init_20();
1124 channel_handler_init_13();
1126 channel_handler_init_15();
1130 channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1132 static int did_init = 0;
1137 channel_handler_init();
1140 for (i = 0; i < channels_alloc; i++) {
1142 if (c->type == SSH_CHANNEL_FREE)
1144 if (ftab[c->type] == NULL)
1146 (*ftab[c->type])(c, readset, writeset);
1147 c = &channels[i]; /* XXX realloc */
1148 if (chan_is_dead(c)) {
1150 * we have to remove the fd's from the select mask
1151 * before the channels are free'd and the fd's are
1155 FD_CLR(c->wfd, writeset);
1157 FD_CLR(c->rfd, readset);
1159 if (c->extended_usage == CHAN_EXTENDED_READ)
1160 FD_CLR(c->efd, readset);
1161 if (c->extended_usage == CHAN_EXTENDED_WRITE)
1162 FD_CLR(c->efd, writeset);
1164 channel_free(c->self);
1170 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1176 n = MAX(*maxfdp, channel_max_fd);
1178 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1179 if (*readsetp == NULL || n > *maxfdp) {
1184 *readsetp = xmalloc(sz);
1185 *writesetp = xmalloc(sz);
1188 memset(*readsetp, 0, sz);
1189 memset(*writesetp, 0, sz);
1192 channel_handler(channel_pre, *readsetp, *writesetp);
1196 channel_after_select(fd_set * readset, fd_set * writeset)
1198 channel_handler(channel_post, readset, writeset);
1201 /* If there is data to send to the connection, enqueue some of it now. */
1204 channel_output_poll()
1209 for (i = 0; i < channels_alloc; i++) {
1212 /* We are only interested in channels that can have buffered incoming data. */
1214 if (c->type != SSH_CHANNEL_OPEN &&
1215 c->type != SSH_CHANNEL_INPUT_DRAINING)
1218 if (c->type != SSH_CHANNEL_OPEN)
1222 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1223 /* XXX is this true? */
1224 debug2("channel %d: no data after CLOSE", c->self);
1228 /* Get the amount of buffered data for this channel. */
1229 if ((c->istate == CHAN_INPUT_OPEN ||
1230 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1231 (len = buffer_len(&c->input)) > 0) {
1232 /* Send some data for the other side over the secure connection. */
1234 if (len > c->remote_window)
1235 len = c->remote_window;
1236 if (len > c->remote_maxpacket)
1237 len = c->remote_maxpacket;
1239 if (packet_is_interactive()) {
1243 /* Keep the packets at reasonable size. */
1244 if (len > packet_get_maxsize()/2)
1245 len = packet_get_maxsize()/2;
1249 packet_start(compat20 ?
1250 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1251 packet_put_int(c->remote_id);
1252 packet_put_string(buffer_ptr(&c->input), len);
1254 buffer_consume(&c->input, len);
1255 c->remote_window -= len;
1257 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1259 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1261 * input-buffer is empty and read-socket shutdown:
1262 * tell peer, that we will not send more data: send IEOF
1266 /* Send extended data, i.e. stderr */
1268 c->remote_window > 0 &&
1269 (len = buffer_len(&c->extended)) > 0 &&
1270 c->extended_usage == CHAN_EXTENDED_READ) {
1271 debug2("channel %d: rwin %d elen %d euse %d",
1272 c->self, c->remote_window, buffer_len(&c->extended),
1274 if (len > c->remote_window)
1275 len = c->remote_window;
1276 if (len > c->remote_maxpacket)
1277 len = c->remote_maxpacket;
1278 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1279 packet_put_int(c->remote_id);
1280 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1281 packet_put_string(buffer_ptr(&c->extended), len);
1283 buffer_consume(&c->extended, len);
1284 c->remote_window -= len;
1285 debug2("channel %d: sent ext data %d", c->self, len);
1291 * This is called when a packet of type CHANNEL_DATA has just been received.
1292 * The message type has already been consumed, but channel number and data is
1297 channel_input_data(int type, int plen, void *ctxt)
1304 /* Get the channel number and verify it. */
1305 id = packet_get_int();
1306 c = channel_lookup(id);
1308 packet_disconnect("Received data for nonexistent channel %d.", id);
1310 /* Ignore any data for non-open channels (might happen on close) */
1311 if (c->type != SSH_CHANNEL_OPEN &&
1312 c->type != SSH_CHANNEL_X11_OPEN)
1315 /* same for protocol 1.5 if output end is no longer open */
1316 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1320 data = packet_get_string(&data_len);
1324 if (data_len > c->local_maxpacket) {
1325 log("channel %d: rcvd big packet %d, maxpack %d",
1326 c->self, data_len, c->local_maxpacket);
1328 if (data_len > c->local_window) {
1329 log("channel %d: rcvd too much data %d, win %d",
1330 c->self, data_len, c->local_window);
1334 c->local_window -= data_len;
1336 packet_integrity_check(plen, 4 + 4 + data_len, type);
1338 buffer_append(&c->output, data, data_len);
1342 channel_input_extended_data(int type, int plen, void *ctxt)
1350 /* Get the channel number and verify it. */
1351 id = packet_get_int();
1352 c = channel_lookup(id);
1355 packet_disconnect("Received extended_data for bad channel %d.", id);
1356 if (c->type != SSH_CHANNEL_OPEN) {
1357 log("channel %d: ext data for non open", id);
1360 tcode = packet_get_int();
1362 c->extended_usage != CHAN_EXTENDED_WRITE ||
1363 tcode != SSH2_EXTENDED_DATA_STDERR) {
1364 log("channel %d: bad ext data", c->self);
1367 data = packet_get_string(&data_len);
1369 if (data_len > c->local_window) {
1370 log("channel %d: rcvd too much extended_data %d, win %d",
1371 c->self, data_len, c->local_window);
1375 debug2("channel %d: rcvd ext data %d", c->self, data_len);
1376 c->local_window -= data_len;
1377 buffer_append(&c->extended, data, data_len);
1383 * Returns true if no channel has too much buffered data, and false if one or
1384 * more channel is overfull.
1388 channel_not_very_much_buffered_data()
1393 for (i = 0; i < channels_alloc; i++) {
1395 if (c->type == SSH_CHANNEL_OPEN) {
1396 if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1397 debug("channel %d: big input buffer %d",
1398 c->self, buffer_len(&c->input));
1401 if (buffer_len(&c->output) > packet_get_maxsize()) {
1402 debug("channel %d: big output buffer %d",
1403 c->self, buffer_len(&c->output));
1412 channel_input_ieof(int type, int plen, void *ctxt)
1417 packet_integrity_check(plen, 4, type);
1419 id = packet_get_int();
1420 c = channel_lookup(id);
1422 packet_disconnect("Received ieof for nonexistent channel %d.", id);
1427 channel_input_close(int type, int plen, void *ctxt)
1432 packet_integrity_check(plen, 4, type);
1434 id = packet_get_int();
1435 c = channel_lookup(id);
1437 packet_disconnect("Received close for nonexistent channel %d.", id);
1440 * Send a confirmation that we have closed the channel and no more
1441 * data is coming for it.
1443 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1444 packet_put_int(c->remote_id);
1448 * If the channel is in closed state, we have sent a close request,
1449 * and the other side will eventually respond with a confirmation.
1450 * Thus, we cannot free the channel here, because then there would be
1451 * no-one to receive the confirmation. The channel gets freed when
1452 * the confirmation arrives.
1454 if (c->type != SSH_CHANNEL_CLOSED) {
1456 * Not a closed channel - mark it as draining, which will
1457 * cause it to be freed later.
1459 buffer_consume(&c->input, buffer_len(&c->input));
1460 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1464 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1466 channel_input_oclose(int type, int plen, void *ctxt)
1468 int id = packet_get_int();
1469 Channel *c = channel_lookup(id);
1470 packet_integrity_check(plen, 4, type);
1472 packet_disconnect("Received oclose for nonexistent channel %d.", id);
1473 chan_rcvd_oclose(c);
1477 channel_input_close_confirmation(int type, int plen, void *ctxt)
1479 int id = packet_get_int();
1480 Channel *c = channel_lookup(id);
1484 packet_disconnect("Received close confirmation for "
1485 "out-of-range channel %d.", id);
1486 if (c->type != SSH_CHANNEL_CLOSED)
1487 packet_disconnect("Received close confirmation for "
1488 "non-closed channel %d (type %d).", id, c->type);
1489 channel_free(c->self);
1493 channel_input_open_confirmation(int type, int plen, void *ctxt)
1499 packet_integrity_check(plen, 4 + 4, type);
1501 id = packet_get_int();
1502 c = channel_lookup(id);
1504 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1505 packet_disconnect("Received open confirmation for "
1506 "non-opening channel %d.", id);
1507 remote_id = packet_get_int();
1508 /* Record the remote channel number and mark that the channel is now open. */
1509 c->remote_id = remote_id;
1510 c->type = SSH_CHANNEL_OPEN;
1513 c->remote_window = packet_get_int();
1514 c->remote_maxpacket = packet_get_int();
1516 if (c->cb_fn != NULL && c->cb_event == type) {
1517 debug2("callback start");
1518 c->cb_fn(c->self, c->cb_arg);
1519 debug2("callback done");
1521 debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1522 c->remote_window, c->remote_maxpacket);
1527 channel_input_open_failure(int type, int plen, void *ctxt)
1530 char *msg = NULL, *lang = NULL;
1534 packet_integrity_check(plen, 4, type);
1536 id = packet_get_int();
1537 c = channel_lookup(id);
1539 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1540 packet_disconnect("Received open failure for "
1541 "non-opening channel %d.", id);
1543 reason = packet_get_int();
1544 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1545 msg = packet_get_string(NULL);
1546 lang = packet_get_string(NULL);
1549 log("channel_open_failure: %d: reason %d %s", id,
1550 reason, msg ? msg : "<no additional info>");
1556 /* Free the channel. This will also close the socket. */
1561 channel_input_channel_request(int type, int plen, void *ctxt)
1566 id = packet_get_int();
1567 c = channel_lookup(id);
1570 (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1571 packet_disconnect("Received request for "
1572 "non-open channel %d.", id);
1573 if (c->cb_fn != NULL && c->cb_event == type) {
1574 debug2("callback start");
1575 c->cb_fn(c->self, c->cb_arg);
1576 debug2("callback done");
1578 char *service = packet_get_string(NULL);
1579 debug("channel %d: rcvd request for %s", c->self, service);
1580 debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1586 channel_input_window_adjust(int type, int plen, void *ctxt)
1594 /* Get the channel number and verify it. */
1595 id = packet_get_int();
1596 c = channel_lookup(id);
1598 if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1599 log("Received window adjust for "
1600 "non-open channel %d.", id);
1603 adjust = packet_get_int();
1605 debug2("channel %d: rcvd adjust %d", id, adjust);
1606 c->remote_window += adjust;
1610 * Stops listening for channels, and removes any unix domain sockets that we
1615 channel_stop_listening()
1618 for (i = 0; i < channels_alloc; i++) {
1619 switch (channels[i].type) {
1620 case SSH_CHANNEL_AUTH_SOCKET:
1621 close(channels[i].sock);
1622 unlink(channels[i].path);
1625 case SSH_CHANNEL_PORT_LISTENER:
1626 case SSH_CHANNEL_RPORT_LISTENER:
1627 case SSH_CHANNEL_X11_LISTENER:
1628 close(channels[i].sock);
1638 * Closes the sockets/fds of all channels. This is used to close extra file
1639 * descriptors after a fork.
1646 for (i = 0; i < channels_alloc; i++)
1647 if (channels[i].type != SSH_CHANNEL_FREE)
1648 channel_close_fds(&channels[i]);
1651 /* Returns true if any channel is still open. */
1654 channel_still_open()
1657 for (i = 0; i < channels_alloc; i++)
1658 switch (channels[i].type) {
1659 case SSH_CHANNEL_FREE:
1660 case SSH_CHANNEL_X11_LISTENER:
1661 case SSH_CHANNEL_PORT_LISTENER:
1662 case SSH_CHANNEL_RPORT_LISTENER:
1663 case SSH_CHANNEL_CLOSED:
1664 case SSH_CHANNEL_AUTH_SOCKET:
1665 case SSH_CHANNEL_DYNAMIC:
1666 case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1668 case SSH_CHANNEL_LARVAL:
1670 fatal("cannot happen: SSH_CHANNEL_LARVAL");
1672 case SSH_CHANNEL_OPENING:
1673 case SSH_CHANNEL_OPEN:
1674 case SSH_CHANNEL_X11_OPEN:
1676 case SSH_CHANNEL_INPUT_DRAINING:
1677 case SSH_CHANNEL_OUTPUT_DRAINING:
1679 fatal("cannot happen: OUT_DRAIN");
1682 fatal("channel_still_open: bad channel type %d", channels[i].type);
1688 /* Returns the id of an open channel suitable for keepaliving */
1694 for (i = 0; i < channels_alloc; i++)
1695 switch (channels[i].type) {
1696 case SSH_CHANNEL_CLOSED:
1697 case SSH_CHANNEL_DYNAMIC:
1698 case SSH_CHANNEL_FREE:
1699 case SSH_CHANNEL_X11_LISTENER:
1700 case SSH_CHANNEL_PORT_LISTENER:
1701 case SSH_CHANNEL_RPORT_LISTENER:
1702 case SSH_CHANNEL_OPENING:
1704 case SSH_CHANNEL_LARVAL:
1705 case SSH_CHANNEL_AUTH_SOCKET:
1706 case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1707 case SSH_CHANNEL_OPEN:
1708 case SSH_CHANNEL_X11_OPEN:
1710 case SSH_CHANNEL_INPUT_DRAINING:
1711 case SSH_CHANNEL_OUTPUT_DRAINING:
1713 fatal("cannot happen: OUT_DRAIN");
1716 fatal("channel_find_open: bad channel type %d", channels[i].type);
1724 * Returns a message describing the currently open forwarded connections,
1725 * suitable for sending to the client. The message contains crlf pairs for
1730 channel_open_message()
1736 buffer_init(&buffer);
1737 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1738 buffer_append(&buffer, buf, strlen(buf));
1739 for (i = 0; i < channels_alloc; i++) {
1740 Channel *c = &channels[i];
1742 case SSH_CHANNEL_FREE:
1743 case SSH_CHANNEL_X11_LISTENER:
1744 case SSH_CHANNEL_PORT_LISTENER:
1745 case SSH_CHANNEL_RPORT_LISTENER:
1746 case SSH_CHANNEL_CLOSED:
1747 case SSH_CHANNEL_AUTH_SOCKET:
1749 case SSH_CHANNEL_LARVAL:
1750 case SSH_CHANNEL_OPENING:
1751 case SSH_CHANNEL_CONNECTING:
1752 case SSH_CHANNEL_DYNAMIC:
1753 case SSH_CHANNEL_OPEN:
1754 case SSH_CHANNEL_X11_OPEN:
1755 case SSH_CHANNEL_INPUT_DRAINING:
1756 case SSH_CHANNEL_OUTPUT_DRAINING:
1757 snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1758 c->self, c->remote_name,
1759 c->type, c->remote_id,
1760 c->istate, buffer_len(&c->input),
1761 c->ostate, buffer_len(&c->output),
1763 buffer_append(&buffer, buf, strlen(buf));
1766 fatal("channel_open_message: bad channel type %d", c->type);
1770 buffer_append(&buffer, "\0", 1);
1771 cp = xstrdup(buffer_ptr(&buffer));
1772 buffer_free(&buffer);
1777 * Initiate forwarding of connections to local port "port" through the secure
1778 * channel to host:port from remote side.
1781 channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1782 u_short port_to_connect, int gateway_ports)
1784 return channel_request_forwarding(
1786 host_to_connect, port_to_connect,
1787 gateway_ports, /*remote_fwd*/ 0);
1791 * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1792 * (SSH_CHANNEL_RPORT_LISTENER).
1795 channel_request_forwarding(
1796 const char *listen_address, u_short listen_port,
1797 const char *host_to_connect, u_short port_to_connect,
1798 int gateway_ports, int remote_fwd)
1800 int success, ch, sock, on = 1, ctype;
1801 struct addrinfo hints, *ai, *aitop;
1802 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1804 struct linger linger;
1809 host = listen_address;
1810 ctype = SSH_CHANNEL_RPORT_LISTENER;
1812 host = host_to_connect;
1813 ctype =SSH_CHANNEL_PORT_LISTENER;
1816 if (strlen(host) > sizeof(channels[0].path) - 1) {
1817 error("Forward host name too long.");
1821 /* XXX listen_address is currently ignored */
1823 * getaddrinfo returns a loopback address if the hostname is
1824 * set to NULL and hints.ai_flags is not AI_PASSIVE
1826 memset(&hints, 0, sizeof(hints));
1827 hints.ai_family = IPv4or6;
1828 hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1829 hints.ai_socktype = SOCK_STREAM;
1830 snprintf(strport, sizeof strport, "%d", listen_port);
1831 if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1832 packet_disconnect("getaddrinfo: fatal error");
1834 for (ai = aitop; ai; ai = ai->ai_next) {
1835 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1837 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1838 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1839 error("channel_request_forwarding: getnameinfo failed");
1842 /* Create a port to listen for the host. */
1843 sock = socket(ai->ai_family, SOCK_STREAM, 0);
1845 /* this is no error since kernel may not support ipv6 */
1846 verbose("socket: %.100s", strerror(errno));
1850 * Set socket options. We would like the socket to disappear
1851 * as soon as it has been closed for whatever reason.
1853 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1855 linger.l_linger = 5;
1856 setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1857 debug("Local forwarding listening on %s port %s.", ntop, strport);
1859 /* Bind the socket to the address. */
1860 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1861 /* address can be in use ipv6 address is already bound */
1863 error("bind: %.100s", strerror(errno));
1865 verbose("bind: %.100s", strerror(errno));
1870 /* Start listening for connections on the socket. */
1871 if (listen(sock, 5) < 0) {
1872 error("listen: %.100s", strerror(errno));
1876 /* Allocate a channel number for the socket. */
1877 ch = channel_new("port listener", ctype, sock, sock, -1,
1878 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1879 0, xstrdup("port listener"), 1);
1880 strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1881 channels[ch].host_port = port_to_connect;
1882 channels[ch].listening_port = listen_port;
1886 error("channel_request_forwarding: cannot listen to port: %d",
1888 freeaddrinfo(aitop);
1893 * Initiate forwarding of connections to port "port" on remote host through
1894 * the secure channel to host:port from local side.
1898 channel_request_remote_forwarding(u_short listen_port,
1899 const char *host_to_connect, u_short port_to_connect)
1901 int payload_len, type, success = 0;
1903 /* Record locally that connection to this host/port is permitted. */
1904 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1905 fatal("channel_request_remote_forwarding: too many forwards");
1907 /* Send the forward request to the remote side. */
1909 const char *address_to_bind = "0.0.0.0";
1910 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1911 packet_put_cstring("tcpip-forward");
1912 packet_put_char(0); /* boolean: want reply */
1913 packet_put_cstring(address_to_bind);
1914 packet_put_int(listen_port);
1916 packet_write_wait();
1917 /* Assume that server accepts the request */
1920 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1921 packet_put_int(listen_port);
1922 packet_put_cstring(host_to_connect);
1923 packet_put_int(port_to_connect);
1925 packet_write_wait();
1927 /* Wait for response from the remote side. */
1928 type = packet_read(&payload_len);
1930 case SSH_SMSG_SUCCESS:
1933 case SSH_SMSG_FAILURE:
1934 log("Warning: Server denied remote port forwarding.");
1937 /* Unknown packet */
1938 packet_disconnect("Protocol error for port forward request:"
1939 "received packet type %d.", type);
1943 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1944 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1945 permitted_opens[num_permitted_opens].listen_port = listen_port;
1946 num_permitted_opens++;
1951 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1952 * listening for the port, and sends back a success reply (or disconnect
1953 * message if there was an error). This never returns if there was an error.
1957 channel_input_port_forward_request(int is_root, int gateway_ports)
1959 u_short port, host_port;
1962 /* Get arguments from the packet. */
1963 port = packet_get_int();
1964 hostname = packet_get_string(NULL);
1965 host_port = packet_get_int();
1969 * Check that an unprivileged user is not trying to forward a
1972 if (port < IPPORT_RESERVED && !is_root)
1973 packet_disconnect("Requested forwarding of port %d but user is not root.",
1976 /* Initiate forwarding */
1977 channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1979 /* Free the argument string. */
1984 * Permits opening to any host/port if permitted_opens[] is empty. This is
1985 * usually called by the server, because the user could connect to any port
1986 * anyway, and the server has no way to know but to trust the client anyway.
1989 channel_permit_all_opens()
1991 if (num_permitted_opens == 0)
1992 all_opens_permitted = 1;
1996 channel_add_permitted_opens(char *host, int port)
1998 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1999 fatal("channel_request_remote_forwarding: too many forwards");
2000 debug("allow port forwarding to host %s port %d", host, port);
2002 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2003 permitted_opens[num_permitted_opens].port_to_connect = port;
2004 num_permitted_opens++;
2006 all_opens_permitted = 0;
2010 channel_clear_permitted_opens(void)
2014 for (i = 0; i < num_permitted_opens; i++)
2015 xfree(permitted_opens[i].host_to_connect);
2016 num_permitted_opens = 0;
2021 /* return socket to remote host, port */
2023 connect_to(const char *host, u_short port)
2025 struct addrinfo hints, *ai, *aitop;
2026 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2030 memset(&hints, 0, sizeof(hints));
2031 hints.ai_family = IPv4or6;
2032 hints.ai_socktype = SOCK_STREAM;
2033 snprintf(strport, sizeof strport, "%d", port);
2034 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
2035 error("connect_to %.100s: unknown host (%s)", host,
2036 gai_strerror(gaierr));
2039 for (ai = aitop; ai; ai = ai->ai_next) {
2040 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2042 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2043 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2044 error("connect_to: getnameinfo failed");
2047 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2049 error("socket: %.100s", strerror(errno));
2052 if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
2053 fatal("connect_to: F_SETFL: %s", strerror(errno));
2054 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2055 errno != EINPROGRESS) {
2056 error("connect_to %.100s port %s: %.100s", ntop, strport,
2059 continue; /* fail -- try next */
2061 break; /* success */
2064 freeaddrinfo(aitop);
2066 error("connect_to %.100s port %d: failed.", host, port);
2074 channel_connect_by_listen_adress(u_short listen_port)
2078 for (i = 0; i < num_permitted_opens; i++)
2079 if (permitted_opens[i].listen_port == listen_port)
2081 permitted_opens[i].host_to_connect,
2082 permitted_opens[i].port_to_connect);
2083 error("WARNING: Server requests forwarding for unknown listen_port %d",
2088 /* Check if connecting to that port is permitted and connect. */
2090 channel_connect_to(const char *host, u_short port)
2094 permit = all_opens_permitted;
2096 for (i = 0; i < num_permitted_opens; i++)
2097 if (permitted_opens[i].port_to_connect == port &&
2098 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2103 log("Received request to connect to host %.100s port %d, "
2104 "but the request was denied.", host, port);
2107 return connect_to(host, port);
2111 * This is called after receiving PORT_OPEN message. This attempts to
2112 * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2113 * or CHANNEL_OPEN_FAILURE.
2117 channel_input_port_open(int type, int plen, void *ctxt)
2120 char *host, *originator_string;
2121 int remote_channel, sock = -1, newch;
2123 remote_channel = packet_get_int();
2124 host = packet_get_string(NULL);
2125 host_port = packet_get_int();
2127 if (have_hostname_in_open) {
2128 originator_string = packet_get_string(NULL);
2130 originator_string = xstrdup("unknown (remote did not supply name)");
2133 sock = channel_connect_to(host, host_port);
2135 newch = channel_allocate(SSH_CHANNEL_CONNECTING,
2136 sock, originator_string);
2137 channels[newch].remote_id = remote_channel;
2139 /*XXX delay answer? */
2140 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2141 packet_put_int(remote_channel);
2142 packet_put_int(newch);
2145 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2146 packet_put_int(remote_channel);
2153 * Creates an internet domain socket for listening for X11 connections.
2154 * Returns a suitable value for the DISPLAY variable, or NULL if an error
2158 #define NUM_SOCKS 10
2161 x11_create_display_inet(int screen_number, int x11_display_offset)
2163 int display_number, sock;
2165 struct addrinfo hints, *ai, *aitop;
2166 char strport[NI_MAXSERV];
2167 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2169 char hostname[MAXHOSTNAMELEN];
2171 for (display_number = x11_display_offset;
2172 display_number < MAX_DISPLAYS;
2174 port = 6000 + display_number;
2175 memset(&hints, 0, sizeof(hints));
2176 hints.ai_family = IPv4or6;
2177 hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
2178 hints.ai_socktype = SOCK_STREAM;
2179 snprintf(strport, sizeof strport, "%d", port);
2180 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2181 error("getaddrinfo: %.100s", gai_strerror(gaierr));
2184 for (ai = aitop; ai; ai = ai->ai_next) {
2185 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2187 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2189 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
2190 error("socket: %.100s", strerror(errno));
2193 debug("x11_create_display_inet: Socket family %d not supported",
2198 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2199 debug("bind port %d: %.100s", port, strerror(errno));
2200 shutdown(sock, SHUT_RDWR);
2206 for (n = 0; n < num_socks; n++) {
2207 shutdown(socks[n], SHUT_RDWR);
2213 socks[num_socks++] = sock;
2214 #ifndef DONT_TRY_OTHER_AF
2215 if (num_socks == NUM_SOCKS)
2221 freeaddrinfo(aitop);
2225 if (display_number >= MAX_DISPLAYS) {
2226 error("Failed to allocate internet-domain X11 display socket.");
2229 /* Start listening for connections on the socket. */
2230 for (n = 0; n < num_socks; n++) {
2232 if (listen(sock, 5) < 0) {
2233 error("listen: %.100s", strerror(errno));
2234 shutdown(sock, SHUT_RDWR);
2240 /* Set up a suitable value for the DISPLAY variable. */
2241 if (gethostname(hostname, sizeof(hostname)) < 0)
2242 fatal("gethostname: %.100s", strerror(errno));
2244 #ifdef IPADDR_IN_DISPLAY
2246 * HPUX detects the local hostname in the DISPLAY variable and tries
2247 * to set up a shared memory connection to the server, which it
2248 * incorrectly supposes to be local.
2250 * The workaround - as used in later $$H and other programs - is
2251 * is to set display to the host's IP address.
2255 struct in_addr my_addr;
2257 he = gethostbyname(hostname);
2259 error("[X11-broken-fwd-hostname-workaround] Could not get "
2260 "IP address for hostname %s.", hostname);
2262 packet_send_debug("[X11-broken-fwd-hostname-workaround]"
2263 "Could not get IP address for hostname %s.", hostname);
2265 shutdown(sock, SHUT_RDWR);
2271 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2273 /* Set DISPLAY to <ip address>:screen.display */
2274 snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr),
2275 display_number, screen_number);
2277 #else /* IPADDR_IN_DISPLAY */
2278 /* Just set DISPLAY to hostname:screen.display */
2279 snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
2280 display_number, screen_number);
2281 #endif /* IPADDR_IN_DISPLAY */
2283 /* Allocate a channel for each socket. */
2284 for (n = 0; n < num_socks; n++) {
2286 (void) channel_new("x11 listener",
2287 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2288 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2289 0, xstrdup("X11 inet listener"), 1);
2292 /* Return a suitable value for the DISPLAY environment variable. */
2293 return xstrdup(display);
2297 #define X_UNIX_PATH "/tmp/.X11-unix/X"
2302 connect_local_xsocket(u_int dnr)
2304 static const char *const x_sockets[] = {
2306 "/var/X/.X11-unix/X" "%u",
2307 "/usr/spool/sockets/X11/" "%u",
2311 struct sockaddr_un addr;
2312 const char *const * path;
2314 for (path = x_sockets; *path; ++path) {
2315 sock = socket(AF_UNIX, SOCK_STREAM, 0);
2317 error("socket: %.100s", strerror(errno));
2318 memset(&addr, 0, sizeof(addr));
2319 addr.sun_family = AF_UNIX;
2320 snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2321 if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2325 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2330 x11_connect_display(void)
2332 int display_number, sock = 0;
2333 const char *display;
2334 char buf[1024], *cp;
2335 struct addrinfo hints, *ai, *aitop;
2336 char strport[NI_MAXSERV];
2339 /* Try to open a socket for the local X server. */
2340 display = getenv("DISPLAY");
2342 error("DISPLAY not set.");
2346 * Now we decode the value of the DISPLAY variable and make a
2347 * connection to the real X server.
2351 * Check if it is a unix domain socket. Unix domain displays are in
2352 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2354 if (strncmp(display, "unix:", 5) == 0 ||
2355 display[0] == ':') {
2356 /* Connect to the unix domain socket. */
2357 if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2358 error("Could not parse display number from DISPLAY: %.100s",
2362 /* Create a socket. */
2363 sock = connect_local_xsocket(display_number);
2367 /* OK, we now have a connection to the display. */
2371 * Connect to an inet socket. The DISPLAY value is supposedly
2372 * hostname:d[.s], where hostname may also be numeric IP address.
2374 strncpy(buf, display, sizeof(buf));
2375 buf[sizeof(buf) - 1] = 0;
2376 cp = strchr(buf, ':');
2378 error("Could not find ':' in DISPLAY: %.100s", display);
2382 /* buf now contains the host name. But first we parse the display number. */
2383 if (sscanf(cp + 1, "%d", &display_number) != 1) {
2384 error("Could not parse display number from DISPLAY: %.100s",
2389 /* Look up the host address */
2390 memset(&hints, 0, sizeof(hints));
2391 hints.ai_family = IPv4or6;
2392 hints.ai_socktype = SOCK_STREAM;
2393 snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2394 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2395 error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
2398 for (ai = aitop; ai; ai = ai->ai_next) {
2399 /* Create a socket. */
2400 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2402 debug("socket: %.100s", strerror(errno));
2405 /* Connect it to the display. */
2406 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2407 debug("connect %.100s port %d: %.100s", buf,
2408 6000 + display_number, strerror(errno));
2415 freeaddrinfo(aitop);
2417 error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
2425 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2426 * the remote channel number. We should do whatever we want, and respond
2427 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2431 x11_input_open(int type, int plen, void *ctxt)
2433 int remote_channel, sock = 0, newch;
2437 /* Get remote channel number. */
2438 remote_channel = packet_get_int();
2440 /* Get remote originator name. */
2441 if (have_hostname_in_open) {
2442 remote_host = packet_get_string(&remote_len);
2445 remote_host = xstrdup("unknown (remote did not supply name)");
2449 debug("Received X11 open request.");
2450 packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
2452 /* Obtain a connection to the real X display. */
2453 sock = x11_connect_display();
2455 /* Send refusal to the remote host. */
2456 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2457 packet_put_int(remote_channel);
2460 /* Allocate a channel for this connection. */
2461 newch = channel_allocate(
2462 (x11_saved_proto == NULL) ?
2463 SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2465 channels[newch].remote_id = remote_channel;
2467 /* Send a confirmation to the remote host. */
2468 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2469 packet_put_int(remote_channel);
2470 packet_put_int(newch);
2475 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2477 deny_input_open(int type, int plen, void *ctxt)
2479 int rchan = packet_get_int();
2481 case SSH_SMSG_AGENT_OPEN:
2482 error("Warning: ssh server tried agent forwarding.");
2484 case SSH_SMSG_X11_OPEN:
2485 error("Warning: ssh server tried X11 forwarding.");
2488 error("deny_input_open: type %d plen %d", type, plen);
2491 error("Warning: this is probably a break in attempt by a malicious server.");
2492 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2493 packet_put_int(rchan);
2498 * Requests forwarding of X11 connections, generates fake authentication
2499 * data, and enables authentication spoofing.
2503 x11_request_forwarding_with_spoofing(int client_session_id,
2504 const char *proto, const char *data)
2506 u_int data_len = (u_int) strlen(data) / 2;
2507 u_int i, value, len;
2513 cp = getenv("DISPLAY");
2515 cp = strchr(cp, ':');
2517 cp = strchr(cp, '.');
2519 screen_number = atoi(cp + 1);
2523 /* Save protocol name. */
2524 x11_saved_proto = xstrdup(proto);
2527 * Extract real authentication data and generate fake data of the
2530 x11_saved_data = xmalloc(data_len);
2531 x11_fake_data = xmalloc(data_len);
2532 for (i = 0; i < data_len; i++) {
2533 if (sscanf(data + 2 * i, "%2x", &value) != 1)
2534 fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2536 rand = arc4random();
2537 x11_saved_data[i] = value;
2538 x11_fake_data[i] = rand & 0xff;
2541 x11_saved_data_len = data_len;
2542 x11_fake_data_len = data_len;
2544 /* Convert the fake data into hex. */
2545 len = 2 * data_len + 1;
2546 new_data = xmalloc(len);
2547 for (i = 0; i < data_len; i++)
2548 snprintf(new_data + 2 * i, len - 2 * i,
2549 "%02x", (u_char) x11_fake_data[i]);
2551 /* Send the request packet. */
2553 channel_request_start(client_session_id, "x11-req", 0);
2554 packet_put_char(0); /* XXX bool single connection */
2556 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2558 packet_put_cstring(proto);
2559 packet_put_cstring(new_data);
2560 packet_put_int(screen_number);
2562 packet_write_wait();
2566 /* Sends a message to the server to request authentication fd forwarding. */
2569 auth_request_forwarding()
2571 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2573 packet_write_wait();
2577 * Returns the name of the forwarded authentication socket. Returns NULL if
2578 * there is no forwarded authentication socket. The returned value points to
2583 auth_get_socket_name()
2585 return channel_forwarded_auth_socket_name;
2588 /* removes the agent forwarding socket */
2591 cleanup_socket(void)
2593 unlink(channel_forwarded_auth_socket_name);
2594 rmdir(channel_forwarded_auth_socket_dir);
2598 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
2599 * This starts forwarding authentication requests.
2603 auth_input_request_forwarding(struct passwd * pw)
2606 struct sockaddr_un sunaddr;
2608 if (auth_get_socket_name() != NULL)
2609 fatal("Protocol error: authentication forwarding requested twice.");
2611 /* Temporarily drop privileged uid for mkdir/bind. */
2612 temporarily_use_uid(pw);
2614 /* Allocate a buffer for the socket name, and format the name. */
2615 channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2616 channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2617 strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2619 /* Create private directory for socket */
2620 if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2621 packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2624 xfree(channel_forwarded_auth_socket_name);
2625 xfree(channel_forwarded_auth_socket_dir);
2626 channel_forwarded_auth_socket_name = NULL;
2627 channel_forwarded_auth_socket_dir = NULL;
2630 snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2631 channel_forwarded_auth_socket_dir, (int) getpid());
2633 if (atexit(cleanup_socket) < 0) {
2636 packet_disconnect("socket: %.100s", strerror(saved));
2638 /* Create the socket. */
2639 sock = socket(AF_UNIX, SOCK_STREAM, 0);
2641 packet_disconnect("socket: %.100s", strerror(errno));
2643 /* Bind it to the name. */
2644 memset(&sunaddr, 0, sizeof(sunaddr));
2645 sunaddr.sun_family = AF_UNIX;
2646 strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2647 sizeof(sunaddr.sun_path));
2649 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2650 packet_disconnect("bind: %.100s", strerror(errno));
2652 /* Restore the privileged uid. */
2655 /* Start listening on the socket. */
2656 if (listen(sock, 5) < 0)
2657 packet_disconnect("listen: %.100s", strerror(errno));
2659 /* Allocate a channel for the authentication agent socket. */
2660 newch = channel_new("auth socket",
2661 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2662 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2663 0, xstrdup("auth socket"), 1);
2665 strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2666 sizeof(channels[newch].path));
2670 /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2673 auth_input_open_request(int type, int plen, void *ctxt)
2675 int remch, sock, newch;
2678 packet_integrity_check(plen, 4, type);
2680 /* Read the remote channel number from the message. */
2681 remch = packet_get_int();
2684 * Get a connection to the local authentication agent (this may again
2687 sock = ssh_get_authentication_socket();
2690 * If we could not connect the agent, send an error message back to
2691 * the server. This should never happen unless the agent dies,
2692 * because authentication forwarding is only enabled if we have an
2696 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2697 packet_put_int(remch);
2701 debug("Forwarding authentication connection.");
2704 * Dummy host name. This will be freed when the channel is freed; it
2705 * will still be valid in the packet_put_string below since the
2706 * channel cannot yet be freed at that point.
2708 dummyname = xstrdup("authentication agent connection");
2710 newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2711 channels[newch].remote_id = remch;
2713 /* Send a confirmation to the remote host. */
2714 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2715 packet_put_int(remch);
2716 packet_put_int(newch);
2721 channel_start_open(int id)
2723 Channel *c = channel_lookup(id);
2725 log("channel_open: %d: bad id", id);
2728 debug("send channel open %d", id);
2729 packet_start(SSH2_MSG_CHANNEL_OPEN);
2730 packet_put_cstring(c->ctype);
2731 packet_put_int(c->self);
2732 packet_put_int(c->local_window);
2733 packet_put_int(c->local_maxpacket);
2736 channel_open(int id)
2739 channel_start_open(id);
2743 channel_request(int id, char *service, int wantconfirm)
2745 channel_request_start(id, service, wantconfirm);
2747 debug("channel request %d: %s", id, service) ;
2750 channel_request_start(int id, char *service, int wantconfirm)
2752 Channel *c = channel_lookup(id);
2754 log("channel_request: %d: bad id", id);
2757 packet_start(SSH2_MSG_CHANNEL_REQUEST);
2758 packet_put_int(c->remote_id);
2759 packet_put_cstring(service);
2760 packet_put_char(wantconfirm);
2763 channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2765 Channel *c = channel_lookup(id);
2767 log("channel_register_callback: %d: bad id", id);
2770 c->cb_event = mtype;
2775 channel_register_cleanup(int id, channel_callback_fn *fn)
2777 Channel *c = channel_lookup(id);
2779 log("channel_register_cleanup: %d: bad id", id);
2782 c->dettach_user = fn;
2785 channel_cancel_cleanup(int id)
2787 Channel *c = channel_lookup(id);
2789 log("channel_cancel_cleanup: %d: bad id", id);
2792 c->dettach_user = NULL;
2795 channel_register_filter(int id, channel_filter_fn *fn)
2797 Channel *c = channel_lookup(id);
2799 log("channel_register_filter: %d: bad id", id);
2802 c->input_filter = fn;
2806 channel_set_fds(int id, int rfd, int wfd, int efd,
2807 int extusage, int nonblock)
2809 Channel *c = channel_lookup(id);
2810 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2811 fatal("channel_activate for non-larval channel %d.", id);
2812 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
2813 c->type = SSH_CHANNEL_OPEN;
2814 /* XXX window size? */
2815 c->local_window = c->local_window_max = c->local_maxpacket * 2;
2816 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2817 packet_put_int(c->remote_id);
2818 packet_put_int(c->local_window);