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 1.114 2001/05/08 19:17:30 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 set to NULL
81 static int channels_alloc = 0;
84 * Maximum file descriptor value used in any of the channels. This is
85 * updated in channel_new.
87 static int channel_max_fd = 0;
89 /* Name and directory of socket for authentication agent forwarding. */
90 static char *channel_forwarded_auth_socket_name = NULL;
91 static char *channel_forwarded_auth_socket_dir = NULL;
93 /* Saved X11 authentication protocol name. */
94 char *x11_saved_proto = NULL;
96 /* Saved X11 authentication data. This is the real data. */
97 char *x11_saved_data = NULL;
98 u_int x11_saved_data_len = 0;
101 * Fake X11 authentication data. This is what the server will be sending us;
102 * we should replace any occurrences of this by the real data.
104 char *x11_fake_data = NULL;
105 u_int x11_fake_data_len;
108 * Data structure for storing which hosts are permitted for forward requests.
109 * The local sides of any remote forwards are stored in this array to prevent
110 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
111 * network (which might be behind a firewall).
114 char *host_to_connect; /* Connect to 'host'. */
115 u_short port_to_connect; /* Connect to 'port'. */
116 u_short listen_port; /* Remote side should listen port number. */
119 /* List of all permitted host/port pairs to connect. */
120 static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
121 /* Number of permitted host/port pairs in the array. */
122 static int num_permitted_opens = 0;
124 * If this is true, all opens are permitted. This is the case on the server
125 * on which we have to trust the client anyway, and the user could do
126 * anything after logging in anyway.
128 static int all_opens_permitted = 0;
130 /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
131 static int have_hostname_in_open = 0;
133 /* AF_UNSPEC or AF_INET or AF_INET6 */
136 void port_open_helper(Channel *c, char *rtype);
138 /* Sets specific protocol options. */
141 channel_set_options(int hostname_in_open)
143 have_hostname_in_open = hostname_in_open;
146 /* lookup channel by id */
149 channel_lookup(int id)
153 if (id < 0 || id > channels_alloc) {
154 log("channel_lookup: %d: bad id", id);
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++)
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] == NULL) {
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++)
251 /* Initialize and return new channel. */
252 c = channels[found] = xmalloc(sizeof(Channel));
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);
278 /* Close all channel fd/socket. */
281 channel_close_fds(Channel *c)
301 /* Free the channel and close its fd/socket. */
304 channel_free(Channel *c)
308 s = channel_open_message();
309 debug("channel_free: channel %d: status: %s", c->self, s);
312 if (c->dettach_user != NULL) {
313 debug("channel_free: channel %d: dettaching channel user", c->self);
314 c->dettach_user(c->self, NULL);
317 shutdown(c->sock, SHUT_RDWR);
318 channel_close_fds(c);
319 buffer_free(&c->input);
320 buffer_free(&c->output);
321 buffer_free(&c->extended);
322 if (c->remote_name) {
323 xfree(c->remote_name);
324 c->remote_name = NULL;
326 channels[c->self] = NULL;
331 * 'channel_pre*' are called just before select() to add any bits relevant to
332 * channels in the select bitmasks.
335 * 'channel_post*': perform any appropriate operations for channels which
336 * have events pending.
338 typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
339 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
340 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
343 channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
345 FD_SET(c->sock, readset);
349 channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
351 debug3("channel %d: waiting for connection", c->self);
352 FD_SET(c->sock, writeset);
356 channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
358 if (buffer_len(&c->input) < packet_get_maxsize())
359 FD_SET(c->sock, readset);
360 if (buffer_len(&c->output) > 0)
361 FD_SET(c->sock, writeset);
365 channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
367 /* test whether sockets are 'alive' for read/write */
368 if (c->istate == CHAN_INPUT_OPEN)
369 if (buffer_len(&c->input) < packet_get_maxsize())
370 FD_SET(c->sock, readset);
371 if (c->ostate == CHAN_OUTPUT_OPEN ||
372 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
373 if (buffer_len(&c->output) > 0) {
374 FD_SET(c->sock, writeset);
375 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
382 channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
384 if (c->istate == CHAN_INPUT_OPEN &&
385 c->remote_window > 0 &&
386 buffer_len(&c->input) < c->remote_window)
387 FD_SET(c->rfd, readset);
388 if (c->ostate == CHAN_OUTPUT_OPEN ||
389 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
390 if (buffer_len(&c->output) > 0) {
391 FD_SET(c->wfd, writeset);
392 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
396 /** XXX check close conditions, too */
398 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
399 buffer_len(&c->extended) > 0)
400 FD_SET(c->efd, writeset);
401 else if (c->extended_usage == CHAN_EXTENDED_READ &&
402 buffer_len(&c->extended) < c->remote_window)
403 FD_SET(c->efd, readset);
408 channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
410 if (buffer_len(&c->input) == 0) {
411 packet_start(SSH_MSG_CHANNEL_CLOSE);
412 packet_put_int(c->remote_id);
414 c->type = SSH_CHANNEL_CLOSED;
415 debug("channel %d: closing after input drain.", c->self);
420 channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
422 if (buffer_len(&c->output) == 0)
425 FD_SET(c->sock, writeset);
429 * This is a special state for X11 authentication spoofing. An opened X11
430 * connection (when authentication spoofing is being done) remains in this
431 * state until the first packet has been completely read. The authentication
432 * data in that packet is then substituted by the real data if it matches the
433 * fake data, and the channel is put into normal mode.
434 * XXX All this happens at the client side.
437 x11_open_helper(Channel *c)
440 u_int proto_len, data_len;
442 /* Check if the fixed size part of the packet is in buffer. */
443 if (buffer_len(&c->output) < 12)
446 /* Parse the lengths of variable-length fields. */
447 ucp = (u_char *) buffer_ptr(&c->output);
448 if (ucp[0] == 0x42) { /* Byte order MSB first. */
449 proto_len = 256 * ucp[6] + ucp[7];
450 data_len = 256 * ucp[8] + ucp[9];
451 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
452 proto_len = ucp[6] + 256 * ucp[7];
453 data_len = ucp[8] + 256 * ucp[9];
455 debug("Initial X11 packet contains bad byte order byte: 0x%x",
460 /* Check if the whole packet is in buffer. */
461 if (buffer_len(&c->output) <
462 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
465 /* Check if authentication protocol matches. */
466 if (proto_len != strlen(x11_saved_proto) ||
467 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
468 debug("X11 connection uses different authentication protocol.");
471 /* Check if authentication data matches our fake data. */
472 if (data_len != x11_fake_data_len ||
473 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
474 x11_fake_data, x11_fake_data_len) != 0) {
475 debug("X11 auth data does not match fake data.");
478 /* Check fake data length */
479 if (x11_fake_data_len != x11_saved_data_len) {
480 error("X11 fake_data_len %d != saved_data_len %d",
481 x11_fake_data_len, x11_saved_data_len);
485 * Received authentication protocol and data match
486 * our fake data. Substitute the fake data with real
489 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
490 x11_saved_data, x11_saved_data_len);
495 channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
497 int ret = x11_open_helper(c);
499 /* Start normal processing for the channel. */
500 c->type = SSH_CHANNEL_OPEN;
501 channel_pre_open_13(c, readset, writeset);
502 } else if (ret == -1) {
504 * We have received an X11 connection that has bad
505 * authentication information.
507 log("X11 connection rejected because of wrong authentication.");
508 buffer_clear(&c->input);
509 buffer_clear(&c->output);
512 c->type = SSH_CHANNEL_CLOSED;
513 packet_start(SSH_MSG_CHANNEL_CLOSE);
514 packet_put_int(c->remote_id);
520 channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
522 int ret = x11_open_helper(c);
524 c->type = SSH_CHANNEL_OPEN;
526 channel_pre_open_20(c, readset, writeset);
528 channel_pre_open_15(c, readset, writeset);
529 } else if (ret == -1) {
530 debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
531 chan_read_failed(c); /** force close? */
532 chan_write_failed(c);
533 debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
537 /* try to decode a socks4 header */
539 channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
542 int len, have, i, found;
548 struct in_addr dest_addr;
551 debug2("channel %d: decode socks4", c->self);
553 have = buffer_len(&c->input);
554 len = sizeof(s4_req);
557 p = buffer_ptr(&c->input);
558 for (found = 0, i = len; i < have; i++) {
564 /* the peer is probably sending garbage */
565 debug("channel %d: decode socks4: too long",
572 buffer_get(&c->input, (char *)&s4_req.version, 1);
573 buffer_get(&c->input, (char *)&s4_req.command, 1);
574 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
575 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
576 have = buffer_len(&c->input);
577 p = buffer_ptr(&c->input);
579 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
581 fatal("channel %d: decode socks4: len %d > have %d",
583 strlcpy(username, p, sizeof(username));
584 buffer_consume(&c->input, len);
585 buffer_consume(&c->input, 1); /* trailing '\0' */
587 host = inet_ntoa(s4_req.dest_addr);
588 strlcpy(c->path, host, sizeof(c->path));
589 c->host_port = ntohs(s4_req.dest_port);
591 debug("channel %d: dynamic request: socks4 host %s port %u command %u",
592 c->self, host, c->host_port, s4_req.command);
594 if (s4_req.command != 1) {
595 debug("channel %d: cannot handle: socks4 cn %d",
596 c->self, s4_req.command);
599 s4_rsp.version = 0; /* vn: 0 for reply */
600 s4_rsp.command = 90; /* cd: req granted */
601 s4_rsp.dest_port = 0; /* ignored */
602 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
603 buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
607 /* dynamic port forwarding */
609 channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
614 have = buffer_len(&c->input);
616 debug2("channel %d: pre_dynamic: have %d", c->self, have);
617 /* buffer_dump(&c->input); */
618 /* check if the fixed size part of the packet is in buffer. */
621 FD_SET(c->sock, readset);
624 /* try to guess the protocol */
625 p = buffer_ptr(&c->input);
628 ret = channel_decode_socks4(c, readset, writeset);
636 } else if (ret == 0) {
637 debug2("channel %d: pre_dynamic: need more", c->self);
639 FD_SET(c->sock, readset);
641 /* switch to the next state */
642 c->type = SSH_CHANNEL_OPENING;
643 port_open_helper(c, "direct-tcpip");
647 /* This is our fake X11 server socket. */
649 channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
652 struct sockaddr addr;
655 char buf[16384], *remote_ipaddr;
658 if (FD_ISSET(c->sock, readset)) {
659 debug("X11 connection requested.");
660 addrlen = sizeof(addr);
661 newsock = accept(c->sock, &addr, &addrlen);
663 error("accept: %.100s", strerror(errno));
666 remote_ipaddr = get_peer_ipaddr(newsock);
667 remote_port = get_peer_port(newsock);
668 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
669 remote_ipaddr, remote_port);
671 nc = channel_new("accepted x11 socket",
672 SSH_CHANNEL_OPENING, newsock, newsock, -1,
673 c->local_window_max, c->local_maxpacket,
677 xfree(remote_ipaddr);
681 packet_start(SSH2_MSG_CHANNEL_OPEN);
682 packet_put_cstring("x11");
683 packet_put_int(nc->self);
684 packet_put_int(c->local_window_max);
685 packet_put_int(c->local_maxpacket);
686 /* originator ipaddr and port */
687 packet_put_cstring(remote_ipaddr);
688 if (datafellows & SSH_BUG_X11FWD) {
689 debug("ssh2 x11 bug compat mode");
691 packet_put_int(remote_port);
695 packet_start(SSH_SMSG_X11_OPEN);
696 packet_put_int(nc->self);
697 if (have_hostname_in_open)
698 packet_put_string(buf, strlen(buf));
701 xfree(remote_ipaddr);
706 port_open_helper(Channel *c, char *rtype)
710 char *remote_ipaddr = get_peer_ipaddr(c->sock);
711 u_short remote_port = get_peer_port(c->sock);
713 direct = (strcmp(rtype, "direct-tcpip") == 0);
715 snprintf(buf, sizeof buf,
716 "%s: listening port %d for %.100s port %d, "
717 "connect from %.200s port %d",
718 rtype, c->listening_port, c->path, c->host_port,
719 remote_ipaddr, remote_port);
721 xfree(c->remote_name);
722 c->remote_name = xstrdup(buf);
725 packet_start(SSH2_MSG_CHANNEL_OPEN);
726 packet_put_cstring(rtype);
727 packet_put_int(c->self);
728 packet_put_int(c->local_window_max);
729 packet_put_int(c->local_maxpacket);
731 /* target host, port */
732 packet_put_cstring(c->path);
733 packet_put_int(c->host_port);
735 /* listen address, port */
736 packet_put_cstring(c->path);
737 packet_put_int(c->listening_port);
739 /* originator host and port */
740 packet_put_cstring(remote_ipaddr);
741 packet_put_int(remote_port);
744 packet_start(SSH_MSG_PORT_OPEN);
745 packet_put_int(c->self);
746 packet_put_cstring(c->path);
747 packet_put_int(c->host_port);
748 if (have_hostname_in_open)
749 packet_put_cstring(c->remote_name);
752 xfree(remote_ipaddr);
756 * This socket is listening for connections to a forwarded TCP/IP port.
759 channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
762 struct sockaddr addr;
763 int newsock, nextstate;
767 if (FD_ISSET(c->sock, readset)) {
768 debug("Connection to port %d forwarding "
769 "to %.100s port %d requested.",
770 c->listening_port, c->path, c->host_port);
772 rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
773 "forwarded-tcpip" : "direct-tcpip";
774 nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :
777 addrlen = sizeof(addr);
778 newsock = accept(c->sock, &addr, &addrlen);
780 error("accept: %.100s", strerror(errno));
783 nc = channel_new(rtype,
784 nextstate, newsock, newsock, -1,
785 c->local_window_max, c->local_maxpacket,
786 0, xstrdup(rtype), 1);
788 error("channel_post_port_listener: no new channel:");
792 nc->listening_port = c->listening_port;
793 nc->host_port = c->host_port;
794 strlcpy(nc->path, c->path, sizeof(nc->path));
796 if (nextstate != SSH_CHANNEL_DYNAMIC)
797 port_open_helper(nc, rtype);
802 * This is the authentication agent socket listening for connections from
806 channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
810 struct sockaddr addr;
813 if (FD_ISSET(c->sock, readset)) {
814 addrlen = sizeof(addr);
815 newsock = accept(c->sock, &addr, &addrlen);
817 error("accept from auth socket: %.100s", strerror(errno));
820 nc = channel_new("accepted auth socket",
821 SSH_CHANNEL_OPENING, newsock, newsock, -1,
822 c->local_window_max, c->local_maxpacket,
823 0, xstrdup("accepted auth socket"), 1);
825 error("channel_post_auth_listener: channel_new failed");
829 packet_start(SSH2_MSG_CHANNEL_OPEN);
830 packet_put_cstring("auth-agent@openssh.com");
831 packet_put_int(nc->self);
832 packet_put_int(c->local_window_max);
833 packet_put_int(c->local_maxpacket);
835 packet_start(SSH_SMSG_AGENT_OPEN);
836 packet_put_int(nc->self);
843 channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
846 int sz = sizeof(err);
848 if (FD_ISSET(c->sock, writeset)) {
849 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
852 error("getsockopt SO_ERROR failed");
855 debug("channel %d: connected", c->self);
856 c->type = SSH_CHANNEL_OPEN;
858 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
859 packet_put_int(c->remote_id);
860 packet_put_int(c->self);
861 packet_put_int(c->local_window);
862 packet_put_int(c->local_maxpacket);
864 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
865 packet_put_int(c->remote_id);
866 packet_put_int(c->self);
869 debug("channel %d: not connected: %s",
870 c->self, strerror(err));
872 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
873 packet_put_int(c->remote_id);
874 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
875 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
876 packet_put_cstring(strerror(err));
877 packet_put_cstring("");
880 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
881 packet_put_int(c->remote_id);
890 channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
896 FD_ISSET(c->rfd, readset)) {
897 len = read(c->rfd, buf, sizeof(buf));
898 if (len < 0 && (errno == EINTR || errno == EAGAIN))
901 debug("channel %d: read<=0 rfd %d len %d",
902 c->self, c->rfd, len);
903 if (c->type != SSH_CHANNEL_OPEN) {
904 debug("channel %d: not open", c->self);
907 } else if (compat13) {
908 buffer_consume(&c->output, buffer_len(&c->output));
909 c->type = SSH_CHANNEL_INPUT_DRAINING;
910 debug("channel %d: status set to input draining.", c->self);
916 if(c->input_filter != NULL) {
917 if (c->input_filter(c, buf, len) == -1) {
918 debug("channel %d: filter stops", c->self);
922 buffer_append(&c->input, buf, len);
928 channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
933 /* Send buffered output data to the socket. */
935 FD_ISSET(c->wfd, writeset) &&
936 buffer_len(&c->output) > 0) {
937 len = write(c->wfd, buffer_ptr(&c->output),
938 buffer_len(&c->output));
939 if (len < 0 && (errno == EINTR || errno == EAGAIN))
942 if (c->type != SSH_CHANNEL_OPEN) {
943 debug("channel %d: not open", c->self);
946 } else if (compat13) {
947 buffer_consume(&c->output, buffer_len(&c->output));
948 debug("channel %d: status set to input draining.", c->self);
949 c->type = SSH_CHANNEL_INPUT_DRAINING;
951 chan_write_failed(c);
955 if (compat20 && c->isatty) {
956 if (tcgetattr(c->wfd, &tio) == 0 &&
957 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
959 * Simulate echo to reduce the impact of
960 * traffic analysis. We need to match the
961 * size of a SSH2_MSG_CHANNEL_DATA message
962 * (4 byte channel id + data)
964 packet_send_ignore(4 + len);
968 buffer_consume(&c->output, len);
969 if (compat20 && len > 0) {
970 c->local_consumed += len;
976 channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
981 /** XXX handle drain efd, too */
983 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
984 FD_ISSET(c->efd, writeset) &&
985 buffer_len(&c->extended) > 0) {
986 len = write(c->efd, buffer_ptr(&c->extended),
987 buffer_len(&c->extended));
988 debug2("channel %d: written %d to efd %d",
989 c->self, len, c->efd);
990 if (len < 0 && (errno == EINTR || errno == EAGAIN))
993 debug2("channel %d: closing write-efd %d",
998 buffer_consume(&c->extended, len);
999 c->local_consumed += len;
1001 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1002 FD_ISSET(c->efd, readset)) {
1003 len = read(c->efd, buf, sizeof(buf));
1004 debug2("channel %d: read %d from efd %d",
1005 c->self, len, c->efd);
1006 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1009 debug2("channel %d: closing read-efd %d",
1014 buffer_append(&c->extended, buf, len);
1021 channel_check_window(Channel *c)
1023 if (c->type == SSH_CHANNEL_OPEN &&
1024 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1025 c->local_window < c->local_window_max/2 &&
1026 c->local_consumed > 0) {
1027 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1028 packet_put_int(c->remote_id);
1029 packet_put_int(c->local_consumed);
1031 debug2("channel %d: window %d sent adjust %d",
1032 c->self, c->local_window,
1034 c->local_window += c->local_consumed;
1035 c->local_consumed = 0;
1041 channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1043 channel_handle_rfd(c, readset, writeset);
1044 channel_handle_wfd(c, readset, writeset);
1048 channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1050 channel_handle_rfd(c, readset, writeset);
1051 channel_handle_wfd(c, readset, writeset);
1052 channel_handle_efd(c, readset, writeset);
1054 channel_check_window(c);
1058 channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1061 /* Send buffered output data to the socket. */
1062 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1063 len = write(c->sock, buffer_ptr(&c->output),
1064 buffer_len(&c->output));
1066 buffer_consume(&c->output, buffer_len(&c->output));
1068 buffer_consume(&c->output, len);
1073 channel_handler_init_20(void)
1075 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1076 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1077 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1078 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1079 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1080 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1081 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1082 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1084 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1085 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1086 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1087 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1088 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1089 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1090 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1094 channel_handler_init_13(void)
1096 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1097 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1098 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1099 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1100 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1101 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1102 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1103 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1104 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1106 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1107 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1108 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1109 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1110 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1111 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1112 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1116 channel_handler_init_15(void)
1118 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1119 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1120 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1121 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1122 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1123 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1124 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1126 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1127 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1128 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1129 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1130 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1131 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1135 channel_handler_init(void)
1138 for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1139 channel_pre[i] = NULL;
1140 channel_post[i] = NULL;
1143 channel_handler_init_20();
1145 channel_handler_init_13();
1147 channel_handler_init_15();
1151 channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1153 static int did_init = 0;
1158 channel_handler_init();
1161 for (i = 0; i < channels_alloc; i++) {
1165 if (ftab[c->type] == NULL)
1167 (*ftab[c->type])(c, readset, writeset);
1168 if (chan_is_dead(c)) {
1170 * we have to remove the fd's from the select mask
1171 * before the channels are free'd and the fd's are
1175 FD_CLR(c->wfd, writeset);
1177 FD_CLR(c->rfd, readset);
1179 if (c->extended_usage == CHAN_EXTENDED_READ)
1180 FD_CLR(c->efd, readset);
1181 if (c->extended_usage == CHAN_EXTENDED_WRITE)
1182 FD_CLR(c->efd, writeset);
1190 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1196 n = MAX(*maxfdp, channel_max_fd);
1198 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1199 if (*readsetp == NULL || n > *maxfdp) {
1204 *readsetp = xmalloc(sz);
1205 *writesetp = xmalloc(sz);
1208 memset(*readsetp, 0, sz);
1209 memset(*writesetp, 0, sz);
1212 channel_handler(channel_pre, *readsetp, *writesetp);
1216 channel_after_select(fd_set * readset, fd_set * writeset)
1218 channel_handler(channel_post, readset, writeset);
1221 /* If there is data to send to the connection, enqueue some of it now. */
1224 channel_output_poll()
1229 for (i = 0; i < channels_alloc; i++) {
1235 /* We are only interested in channels that can have buffered incoming data. */
1237 if (c->type != SSH_CHANNEL_OPEN &&
1238 c->type != SSH_CHANNEL_INPUT_DRAINING)
1241 if (c->type != SSH_CHANNEL_OPEN)
1245 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1246 /* XXX is this true? */
1247 debug2("channel %d: no data after CLOSE", c->self);
1251 /* Get the amount of buffered data for this channel. */
1252 if ((c->istate == CHAN_INPUT_OPEN ||
1253 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1254 (len = buffer_len(&c->input)) > 0) {
1255 /* Send some data for the other side over the secure connection. */
1257 if (len > c->remote_window)
1258 len = c->remote_window;
1259 if (len > c->remote_maxpacket)
1260 len = c->remote_maxpacket;
1262 if (packet_is_interactive()) {
1266 /* Keep the packets at reasonable size. */
1267 if (len > packet_get_maxsize()/2)
1268 len = packet_get_maxsize()/2;
1272 packet_start(compat20 ?
1273 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1274 packet_put_int(c->remote_id);
1275 packet_put_string(buffer_ptr(&c->input), len);
1277 buffer_consume(&c->input, len);
1278 c->remote_window -= len;
1280 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1282 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1284 * input-buffer is empty and read-socket shutdown:
1285 * tell peer, that we will not send more data: send IEOF
1289 /* Send extended data, i.e. stderr */
1291 c->remote_window > 0 &&
1292 (len = buffer_len(&c->extended)) > 0 &&
1293 c->extended_usage == CHAN_EXTENDED_READ) {
1294 debug2("channel %d: rwin %d elen %d euse %d",
1295 c->self, c->remote_window, buffer_len(&c->extended),
1297 if (len > c->remote_window)
1298 len = c->remote_window;
1299 if (len > c->remote_maxpacket)
1300 len = c->remote_maxpacket;
1301 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1302 packet_put_int(c->remote_id);
1303 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1304 packet_put_string(buffer_ptr(&c->extended), len);
1306 buffer_consume(&c->extended, len);
1307 c->remote_window -= len;
1308 debug2("channel %d: sent ext data %d", c->self, len);
1314 * This is called when a packet of type CHANNEL_DATA has just been received.
1315 * The message type has already been consumed, but channel number and data is
1320 channel_input_data(int type, int plen, void *ctxt)
1327 /* Get the channel number and verify it. */
1328 id = packet_get_int();
1329 c = channel_lookup(id);
1331 packet_disconnect("Received data for nonexistent channel %d.", id);
1333 /* Ignore any data for non-open channels (might happen on close) */
1334 if (c->type != SSH_CHANNEL_OPEN &&
1335 c->type != SSH_CHANNEL_X11_OPEN)
1338 /* same for protocol 1.5 if output end is no longer open */
1339 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1343 data = packet_get_string(&data_len);
1347 if (data_len > c->local_maxpacket) {
1348 log("channel %d: rcvd big packet %d, maxpack %d",
1349 c->self, data_len, c->local_maxpacket);
1351 if (data_len > c->local_window) {
1352 log("channel %d: rcvd too much data %d, win %d",
1353 c->self, data_len, c->local_window);
1357 c->local_window -= data_len;
1359 packet_integrity_check(plen, 4 + 4 + data_len, type);
1361 buffer_append(&c->output, data, data_len);
1365 channel_input_extended_data(int type, int plen, void *ctxt)
1373 /* Get the channel number and verify it. */
1374 id = packet_get_int();
1375 c = channel_lookup(id);
1378 packet_disconnect("Received extended_data for bad channel %d.", id);
1379 if (c->type != SSH_CHANNEL_OPEN) {
1380 log("channel %d: ext data for non open", id);
1383 tcode = packet_get_int();
1385 c->extended_usage != CHAN_EXTENDED_WRITE ||
1386 tcode != SSH2_EXTENDED_DATA_STDERR) {
1387 log("channel %d: bad ext data", c->self);
1390 data = packet_get_string(&data_len);
1392 if (data_len > c->local_window) {
1393 log("channel %d: rcvd too much extended_data %d, win %d",
1394 c->self, data_len, c->local_window);
1398 debug2("channel %d: rcvd ext data %d", c->self, data_len);
1399 c->local_window -= data_len;
1400 buffer_append(&c->extended, data, data_len);
1406 * Returns true if no channel has too much buffered data, and false if one or
1407 * more channel is overfull.
1411 channel_not_very_much_buffered_data()
1416 for (i = 0; i < channels_alloc; i++) {
1418 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1419 if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1420 debug("channel %d: big input buffer %d",
1421 c->self, buffer_len(&c->input));
1424 if (buffer_len(&c->output) > packet_get_maxsize()) {
1425 debug("channel %d: big output buffer %d",
1426 c->self, buffer_len(&c->output));
1435 channel_input_ieof(int type, int plen, void *ctxt)
1440 packet_integrity_check(plen, 4, type);
1442 id = packet_get_int();
1443 c = channel_lookup(id);
1445 packet_disconnect("Received ieof for nonexistent channel %d.", id);
1450 channel_input_close(int type, int plen, void *ctxt)
1455 packet_integrity_check(plen, 4, type);
1457 id = packet_get_int();
1458 c = channel_lookup(id);
1460 packet_disconnect("Received close for nonexistent channel %d.", id);
1463 * Send a confirmation that we have closed the channel and no more
1464 * data is coming for it.
1466 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1467 packet_put_int(c->remote_id);
1471 * If the channel is in closed state, we have sent a close request,
1472 * and the other side will eventually respond with a confirmation.
1473 * Thus, we cannot free the channel here, because then there would be
1474 * no-one to receive the confirmation. The channel gets freed when
1475 * the confirmation arrives.
1477 if (c->type != SSH_CHANNEL_CLOSED) {
1479 * Not a closed channel - mark it as draining, which will
1480 * cause it to be freed later.
1482 buffer_consume(&c->input, buffer_len(&c->input));
1483 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1487 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1489 channel_input_oclose(int type, int plen, void *ctxt)
1491 int id = packet_get_int();
1492 Channel *c = channel_lookup(id);
1493 packet_integrity_check(plen, 4, type);
1495 packet_disconnect("Received oclose for nonexistent channel %d.", id);
1496 chan_rcvd_oclose(c);
1500 channel_input_close_confirmation(int type, int plen, void *ctxt)
1502 int id = packet_get_int();
1503 Channel *c = channel_lookup(id);
1507 packet_disconnect("Received close confirmation for "
1508 "out-of-range channel %d.", id);
1509 if (c->type != SSH_CHANNEL_CLOSED)
1510 packet_disconnect("Received close confirmation for "
1511 "non-closed channel %d (type %d).", id, c->type);
1516 channel_input_open_confirmation(int type, int plen, void *ctxt)
1522 packet_integrity_check(plen, 4 + 4, type);
1524 id = packet_get_int();
1525 c = channel_lookup(id);
1527 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1528 packet_disconnect("Received open confirmation for "
1529 "non-opening channel %d.", id);
1530 remote_id = packet_get_int();
1531 /* Record the remote channel number and mark that the channel is now open. */
1532 c->remote_id = remote_id;
1533 c->type = SSH_CHANNEL_OPEN;
1536 c->remote_window = packet_get_int();
1537 c->remote_maxpacket = packet_get_int();
1539 if (c->cb_fn != NULL && c->cb_event == type) {
1540 debug2("callback start");
1541 c->cb_fn(c->self, c->cb_arg);
1542 debug2("callback done");
1544 debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1545 c->remote_window, c->remote_maxpacket);
1550 reason2txt(int reason)
1553 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1554 return "administratively prohibited";
1555 case SSH2_OPEN_CONNECT_FAILED:
1556 return "connect failed";
1557 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1558 return "unknown channel type";
1559 case SSH2_OPEN_RESOURCE_SHORTAGE:
1560 return "resource shortage";
1562 return "unkown reason";
1566 channel_input_open_failure(int type, int plen, void *ctxt)
1569 char *msg = NULL, *lang = NULL;
1573 packet_integrity_check(plen, 4, type);
1575 id = packet_get_int();
1576 c = channel_lookup(id);
1578 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1579 packet_disconnect("Received open failure for "
1580 "non-opening channel %d.", id);
1582 reason = packet_get_int();
1583 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1584 msg = packet_get_string(NULL);
1585 lang = packet_get_string(NULL);
1588 log("channel %d: open failed: %s%s%s", id,
1589 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1595 /* Free the channel. This will also close the socket. */
1600 channel_input_channel_request(int type, int plen, void *ctxt)
1605 id = packet_get_int();
1606 c = channel_lookup(id);
1609 (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1610 packet_disconnect("Received request for "
1611 "non-open channel %d.", id);
1612 if (c->cb_fn != NULL && c->cb_event == type) {
1613 debug2("callback start");
1614 c->cb_fn(c->self, c->cb_arg);
1615 debug2("callback done");
1617 char *service = packet_get_string(NULL);
1618 debug("channel %d: rcvd request for %s", c->self, service);
1619 debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1625 channel_input_window_adjust(int type, int plen, void *ctxt)
1633 /* Get the channel number and verify it. */
1634 id = packet_get_int();
1635 c = channel_lookup(id);
1637 if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1638 log("Received window adjust for "
1639 "non-open channel %d.", id);
1642 adjust = packet_get_int();
1644 debug2("channel %d: rcvd adjust %d", id, adjust);
1645 c->remote_window += adjust;
1649 * Stops listening for channels, and removes any unix domain sockets that we
1654 channel_stop_listening()
1659 for (i = 0; i < channels_alloc; i++) {
1663 case SSH_CHANNEL_AUTH_SOCKET:
1668 case SSH_CHANNEL_PORT_LISTENER:
1669 case SSH_CHANNEL_RPORT_LISTENER:
1670 case SSH_CHANNEL_X11_LISTENER:
1682 * Closes the sockets/fds of all channels. This is used to close extra file
1683 * descriptors after a fork.
1691 for (i = 0; i < channels_alloc; i++)
1692 if (channels[i] != NULL)
1693 channel_close_fds(channels[i]);
1696 /* Returns true if any channel is still open. */
1699 channel_still_open()
1704 for (i = 0; i < channels_alloc; i++) {
1709 case SSH_CHANNEL_X11_LISTENER:
1710 case SSH_CHANNEL_PORT_LISTENER:
1711 case SSH_CHANNEL_RPORT_LISTENER:
1712 case SSH_CHANNEL_CLOSED:
1713 case SSH_CHANNEL_AUTH_SOCKET:
1714 case SSH_CHANNEL_DYNAMIC:
1715 case SSH_CHANNEL_CONNECTING:
1717 case SSH_CHANNEL_LARVAL:
1719 fatal("cannot happen: SSH_CHANNEL_LARVAL");
1721 case SSH_CHANNEL_OPENING:
1722 case SSH_CHANNEL_OPEN:
1723 case SSH_CHANNEL_X11_OPEN:
1725 case SSH_CHANNEL_INPUT_DRAINING:
1726 case SSH_CHANNEL_OUTPUT_DRAINING:
1728 fatal("cannot happen: OUT_DRAIN");
1731 fatal("channel_still_open: bad channel type %d", c->type);
1738 /* Returns the id of an open channel suitable for keepaliving */
1746 for (i = 0; i < channels_alloc; i++) {
1751 case SSH_CHANNEL_CLOSED:
1752 case SSH_CHANNEL_DYNAMIC:
1753 case SSH_CHANNEL_X11_LISTENER:
1754 case SSH_CHANNEL_PORT_LISTENER:
1755 case SSH_CHANNEL_RPORT_LISTENER:
1756 case SSH_CHANNEL_OPENING:
1757 case SSH_CHANNEL_CONNECTING:
1759 case SSH_CHANNEL_LARVAL:
1760 case SSH_CHANNEL_AUTH_SOCKET:
1761 case SSH_CHANNEL_OPEN:
1762 case SSH_CHANNEL_X11_OPEN:
1764 case SSH_CHANNEL_INPUT_DRAINING:
1765 case SSH_CHANNEL_OUTPUT_DRAINING:
1767 fatal("cannot happen: OUT_DRAIN");
1770 fatal("channel_find_open: bad channel type %d", c->type);
1779 * Returns a message describing the currently open forwarded connections,
1780 * suitable for sending to the client. The message contains crlf pairs for
1785 channel_open_message()
1789 char buf[1024], *cp;
1792 buffer_init(&buffer);
1793 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1794 buffer_append(&buffer, buf, strlen(buf));
1795 for (i = 0; i < channels_alloc; i++) {
1800 case SSH_CHANNEL_X11_LISTENER:
1801 case SSH_CHANNEL_PORT_LISTENER:
1802 case SSH_CHANNEL_RPORT_LISTENER:
1803 case SSH_CHANNEL_CLOSED:
1804 case SSH_CHANNEL_AUTH_SOCKET:
1806 case SSH_CHANNEL_LARVAL:
1807 case SSH_CHANNEL_OPENING:
1808 case SSH_CHANNEL_CONNECTING:
1809 case SSH_CHANNEL_DYNAMIC:
1810 case SSH_CHANNEL_OPEN:
1811 case SSH_CHANNEL_X11_OPEN:
1812 case SSH_CHANNEL_INPUT_DRAINING:
1813 case SSH_CHANNEL_OUTPUT_DRAINING:
1814 snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1815 c->self, c->remote_name,
1816 c->type, c->remote_id,
1817 c->istate, buffer_len(&c->input),
1818 c->ostate, buffer_len(&c->output),
1820 buffer_append(&buffer, buf, strlen(buf));
1823 fatal("channel_open_message: bad channel type %d", c->type);
1827 buffer_append(&buffer, "\0", 1);
1828 cp = xstrdup(buffer_ptr(&buffer));
1829 buffer_free(&buffer);
1834 * Initiate forwarding of connections to local port "port" through the secure
1835 * channel to host:port from remote side.
1838 channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1839 u_short port_to_connect, int gateway_ports)
1841 return channel_request_forwarding(
1843 host_to_connect, port_to_connect,
1844 gateway_ports, /*remote_fwd*/ 0);
1848 * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1849 * (SSH_CHANNEL_RPORT_LISTENER).
1852 channel_request_forwarding(
1853 const char *listen_address, u_short listen_port,
1854 const char *host_to_connect, u_short port_to_connect,
1855 int gateway_ports, int remote_fwd)
1858 int success, sock, on = 1, ctype;
1859 struct addrinfo hints, *ai, *aitop;
1860 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1862 struct linger linger;
1867 host = listen_address;
1868 ctype = SSH_CHANNEL_RPORT_LISTENER;
1870 host = host_to_connect;
1871 ctype =SSH_CHANNEL_PORT_LISTENER;
1874 if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1875 error("Forward host name too long.");
1879 /* XXX listen_address is currently ignored */
1881 * getaddrinfo returns a loopback address if the hostname is
1882 * set to NULL and hints.ai_flags is not AI_PASSIVE
1884 memset(&hints, 0, sizeof(hints));
1885 hints.ai_family = IPv4or6;
1886 hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1887 hints.ai_socktype = SOCK_STREAM;
1888 snprintf(strport, sizeof strport, "%d", listen_port);
1889 if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1890 packet_disconnect("getaddrinfo: fatal error");
1892 for (ai = aitop; ai; ai = ai->ai_next) {
1893 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1895 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1896 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1897 error("channel_request_forwarding: getnameinfo failed");
1900 /* Create a port to listen for the host. */
1901 sock = socket(ai->ai_family, SOCK_STREAM, 0);
1903 /* this is no error since kernel may not support ipv6 */
1904 verbose("socket: %.100s", strerror(errno));
1908 * Set socket options. We would like the socket to disappear
1909 * as soon as it has been closed for whatever reason.
1911 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1913 linger.l_linger = 5;
1914 setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1915 debug("Local forwarding listening on %s port %s.", ntop, strport);
1917 /* Bind the socket to the address. */
1918 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1919 /* address can be in use ipv6 address is already bound */
1921 error("bind: %.100s", strerror(errno));
1923 verbose("bind: %.100s", strerror(errno));
1928 /* Start listening for connections on the socket. */
1929 if (listen(sock, 5) < 0) {
1930 error("listen: %.100s", strerror(errno));
1934 /* Allocate a channel number for the socket. */
1935 c = channel_new("port listener", ctype, sock, sock, -1,
1936 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1937 0, xstrdup("port listener"), 1);
1939 error("channel_request_forwarding: channel_new failed");
1943 strlcpy(c->path, host, sizeof(c->path));
1944 c->host_port = port_to_connect;
1945 c->listening_port = listen_port;
1949 error("channel_request_forwarding: cannot listen to port: %d",
1951 freeaddrinfo(aitop);
1956 * Initiate forwarding of connections to port "port" on remote host through
1957 * the secure channel to host:port from local side.
1961 channel_request_remote_forwarding(u_short listen_port,
1962 const char *host_to_connect, u_short port_to_connect)
1964 int payload_len, type, success = 0;
1966 /* Record locally that connection to this host/port is permitted. */
1967 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1968 fatal("channel_request_remote_forwarding: too many forwards");
1970 /* Send the forward request to the remote side. */
1972 const char *address_to_bind = "0.0.0.0";
1973 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1974 packet_put_cstring("tcpip-forward");
1975 packet_put_char(0); /* boolean: want reply */
1976 packet_put_cstring(address_to_bind);
1977 packet_put_int(listen_port);
1979 packet_write_wait();
1980 /* Assume that server accepts the request */
1983 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1984 packet_put_int(listen_port);
1985 packet_put_cstring(host_to_connect);
1986 packet_put_int(port_to_connect);
1988 packet_write_wait();
1990 /* Wait for response from the remote side. */
1991 type = packet_read(&payload_len);
1993 case SSH_SMSG_SUCCESS:
1996 case SSH_SMSG_FAILURE:
1997 log("Warning: Server denied remote port forwarding.");
2000 /* Unknown packet */
2001 packet_disconnect("Protocol error for port forward request:"
2002 "received packet type %d.", type);
2006 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2007 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2008 permitted_opens[num_permitted_opens].listen_port = listen_port;
2009 num_permitted_opens++;
2014 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2015 * listening for the port, and sends back a success reply (or disconnect
2016 * message if there was an error). This never returns if there was an error.
2020 channel_input_port_forward_request(int is_root, int gateway_ports)
2022 u_short port, host_port;
2025 /* Get arguments from the packet. */
2026 port = packet_get_int();
2027 hostname = packet_get_string(NULL);
2028 host_port = packet_get_int();
2032 * Check that an unprivileged user is not trying to forward a
2035 if (port < IPPORT_RESERVED && !is_root)
2036 packet_disconnect("Requested forwarding of port %d but user is not root.",
2039 /* Initiate forwarding */
2040 channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
2042 /* Free the argument string. */
2047 * Permits opening to any host/port if permitted_opens[] is empty. This is
2048 * usually called by the server, because the user could connect to any port
2049 * anyway, and the server has no way to know but to trust the client anyway.
2052 channel_permit_all_opens()
2054 if (num_permitted_opens == 0)
2055 all_opens_permitted = 1;
2059 channel_add_permitted_opens(char *host, int port)
2061 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2062 fatal("channel_request_remote_forwarding: too many forwards");
2063 debug("allow port forwarding to host %s port %d", host, port);
2065 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2066 permitted_opens[num_permitted_opens].port_to_connect = port;
2067 num_permitted_opens++;
2069 all_opens_permitted = 0;
2073 channel_clear_permitted_opens(void)
2077 for (i = 0; i < num_permitted_opens; i++)
2078 xfree(permitted_opens[i].host_to_connect);
2079 num_permitted_opens = 0;
2084 /* return socket to remote host, port */
2086 connect_to(const char *host, u_short port)
2088 struct addrinfo hints, *ai, *aitop;
2089 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2093 memset(&hints, 0, sizeof(hints));
2094 hints.ai_family = IPv4or6;
2095 hints.ai_socktype = SOCK_STREAM;
2096 snprintf(strport, sizeof strport, "%d", port);
2097 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
2098 error("connect_to %.100s: unknown host (%s)", host,
2099 gai_strerror(gaierr));
2102 for (ai = aitop; ai; ai = ai->ai_next) {
2103 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2105 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2106 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2107 error("connect_to: getnameinfo failed");
2110 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2112 error("socket: %.100s", strerror(errno));
2115 if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
2116 fatal("connect_to: F_SETFL: %s", strerror(errno));
2117 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2118 errno != EINPROGRESS) {
2119 error("connect_to %.100s port %s: %.100s", ntop, strport,
2122 continue; /* fail -- try next */
2124 break; /* success */
2127 freeaddrinfo(aitop);
2129 error("connect_to %.100s port %d: failed.", host, port);
2137 channel_connect_by_listen_adress(u_short listen_port)
2141 for (i = 0; i < num_permitted_opens; i++)
2142 if (permitted_opens[i].listen_port == listen_port)
2144 permitted_opens[i].host_to_connect,
2145 permitted_opens[i].port_to_connect);
2146 error("WARNING: Server requests forwarding for unknown listen_port %d",
2151 /* Check if connecting to that port is permitted and connect. */
2153 channel_connect_to(const char *host, u_short port)
2157 permit = all_opens_permitted;
2159 for (i = 0; i < num_permitted_opens; i++)
2160 if (permitted_opens[i].port_to_connect == port &&
2161 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2166 log("Received request to connect to host %.100s port %d, "
2167 "but the request was denied.", host, port);
2170 return connect_to(host, port);
2174 * This is called after receiving PORT_OPEN message. This attempts to
2175 * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2176 * or CHANNEL_OPEN_FAILURE.
2180 channel_input_port_open(int type, int plen, void *ctxt)
2184 char *host, *originator_string;
2185 int remote_id, sock = -1;
2187 remote_id = packet_get_int();
2188 host = packet_get_string(NULL);
2189 host_port = packet_get_int();
2191 if (have_hostname_in_open) {
2192 originator_string = packet_get_string(NULL);
2194 originator_string = xstrdup("unknown (remote did not supply name)");
2197 sock = channel_connect_to(host, host_port);
2199 c = channel_new("connected socket",
2200 SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2201 originator_string, 1);
2203 error("channel_input_port_open: channel_new failed");
2206 c->remote_id = remote_id;
2210 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2211 packet_put_int(remote_id);
2218 * Creates an internet domain socket for listening for X11 connections.
2219 * Returns a suitable value for the DISPLAY variable, or NULL if an error
2223 #define NUM_SOCKS 10
2226 x11_create_display_inet(int screen_number, int x11_display_offset)
2228 int display_number, sock;
2230 struct addrinfo hints, *ai, *aitop;
2231 char strport[NI_MAXSERV];
2232 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2234 char hostname[MAXHOSTNAMELEN];
2236 for (display_number = x11_display_offset;
2237 display_number < MAX_DISPLAYS;
2239 port = 6000 + display_number;
2240 memset(&hints, 0, sizeof(hints));
2241 hints.ai_family = IPv4or6;
2242 hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
2243 hints.ai_socktype = SOCK_STREAM;
2244 snprintf(strport, sizeof strport, "%d", port);
2245 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2246 error("getaddrinfo: %.100s", gai_strerror(gaierr));
2249 for (ai = aitop; ai; ai = ai->ai_next) {
2250 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2252 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2254 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
2255 error("socket: %.100s", strerror(errno));
2258 debug("x11_create_display_inet: Socket family %d not supported",
2263 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2264 debug("bind port %d: %.100s", port, strerror(errno));
2265 shutdown(sock, SHUT_RDWR);
2271 for (n = 0; n < num_socks; n++) {
2272 shutdown(socks[n], SHUT_RDWR);
2278 socks[num_socks++] = sock;
2279 #ifndef DONT_TRY_OTHER_AF
2280 if (num_socks == NUM_SOCKS)
2286 freeaddrinfo(aitop);
2290 if (display_number >= MAX_DISPLAYS) {
2291 error("Failed to allocate internet-domain X11 display socket.");
2294 /* Start listening for connections on the socket. */
2295 for (n = 0; n < num_socks; n++) {
2297 if (listen(sock, 5) < 0) {
2298 error("listen: %.100s", strerror(errno));
2299 shutdown(sock, SHUT_RDWR);
2305 /* Set up a suitable value for the DISPLAY variable. */
2306 if (gethostname(hostname, sizeof(hostname)) < 0)
2307 fatal("gethostname: %.100s", strerror(errno));
2309 #ifdef IPADDR_IN_DISPLAY
2311 * HPUX detects the local hostname in the DISPLAY variable and tries
2312 * to set up a shared memory connection to the server, which it
2313 * incorrectly supposes to be local.
2315 * The workaround - as used in later $$H and other programs - is
2316 * is to set display to the host's IP address.
2320 struct in_addr my_addr;
2322 he = gethostbyname(hostname);
2324 error("[X11-broken-fwd-hostname-workaround] Could not get "
2325 "IP address for hostname %s.", hostname);
2327 packet_send_debug("[X11-broken-fwd-hostname-workaround]"
2328 "Could not get IP address for hostname %s.", hostname);
2330 shutdown(sock, SHUT_RDWR);
2336 memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
2338 /* Set DISPLAY to <ip address>:screen.display */
2339 snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr),
2340 display_number, screen_number);
2342 #else /* IPADDR_IN_DISPLAY */
2343 /* Just set DISPLAY to hostname:screen.display */
2344 snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
2345 display_number, screen_number);
2346 #endif /* IPADDR_IN_DISPLAY */
2348 /* Allocate a channel for each socket. */
2349 for (n = 0; n < num_socks; n++) {
2351 (void) channel_new("x11 listener",
2352 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2353 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2354 0, xstrdup("X11 inet listener"), 1);
2357 /* Return a suitable value for the DISPLAY environment variable. */
2358 return xstrdup(display);
2362 #define X_UNIX_PATH "/tmp/.X11-unix/X"
2367 connect_local_xsocket(u_int dnr)
2369 static const char *const x_sockets[] = {
2371 "/var/X/.X11-unix/X" "%u",
2372 "/usr/spool/sockets/X11/" "%u",
2376 struct sockaddr_un addr;
2377 const char *const * path;
2379 for (path = x_sockets; *path; ++path) {
2380 sock = socket(AF_UNIX, SOCK_STREAM, 0);
2382 error("socket: %.100s", strerror(errno));
2383 memset(&addr, 0, sizeof(addr));
2384 addr.sun_family = AF_UNIX;
2385 snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2386 if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2390 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2395 x11_connect_display(void)
2397 int display_number, sock = 0;
2398 const char *display;
2399 char buf[1024], *cp;
2400 struct addrinfo hints, *ai, *aitop;
2401 char strport[NI_MAXSERV];
2404 /* Try to open a socket for the local X server. */
2405 display = getenv("DISPLAY");
2407 error("DISPLAY not set.");
2411 * Now we decode the value of the DISPLAY variable and make a
2412 * connection to the real X server.
2416 * Check if it is a unix domain socket. Unix domain displays are in
2417 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2419 if (strncmp(display, "unix:", 5) == 0 ||
2420 display[0] == ':') {
2421 /* Connect to the unix domain socket. */
2422 if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2423 error("Could not parse display number from DISPLAY: %.100s",
2427 /* Create a socket. */
2428 sock = connect_local_xsocket(display_number);
2432 /* OK, we now have a connection to the display. */
2436 * Connect to an inet socket. The DISPLAY value is supposedly
2437 * hostname:d[.s], where hostname may also be numeric IP address.
2439 strncpy(buf, display, sizeof(buf));
2440 buf[sizeof(buf) - 1] = 0;
2441 cp = strchr(buf, ':');
2443 error("Could not find ':' in DISPLAY: %.100s", display);
2447 /* buf now contains the host name. But first we parse the display number. */
2448 if (sscanf(cp + 1, "%d", &display_number) != 1) {
2449 error("Could not parse display number from DISPLAY: %.100s",
2454 /* Look up the host address */
2455 memset(&hints, 0, sizeof(hints));
2456 hints.ai_family = IPv4or6;
2457 hints.ai_socktype = SOCK_STREAM;
2458 snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2459 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2460 error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
2463 for (ai = aitop; ai; ai = ai->ai_next) {
2464 /* Create a socket. */
2465 sock = socket(ai->ai_family, SOCK_STREAM, 0);
2467 debug("socket: %.100s", strerror(errno));
2470 /* Connect it to the display. */
2471 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2472 debug("connect %.100s port %d: %.100s", buf,
2473 6000 + display_number, strerror(errno));
2480 freeaddrinfo(aitop);
2482 error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
2490 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2491 * the remote channel number. We should do whatever we want, and respond
2492 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2496 x11_input_open(int type, int plen, void *ctxt)
2499 int remote_id, sock = 0;
2502 debug("Received X11 open request.");
2504 remote_id = packet_get_int();
2505 if (have_hostname_in_open) {
2506 remote_host = packet_get_string(NULL);
2508 remote_host = xstrdup("unknown (remote did not supply name)");
2512 /* Obtain a connection to the real X display. */
2513 sock = x11_connect_display();
2515 /* Allocate a channel for this connection. */
2516 c = channel_new("connected x11 socket",
2517 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2520 error("x11_input_open: channel_new failed");
2523 c->remote_id = remote_id;
2527 /* Send refusal to the remote host. */
2528 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2529 packet_put_int(remote_id);
2531 /* Send a confirmation to the remote host. */
2532 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2533 packet_put_int(remote_id);
2534 packet_put_int(c->self);
2539 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2541 deny_input_open(int type, int plen, void *ctxt)
2543 int rchan = packet_get_int();
2545 case SSH_SMSG_AGENT_OPEN:
2546 error("Warning: ssh server tried agent forwarding.");
2548 case SSH_SMSG_X11_OPEN:
2549 error("Warning: ssh server tried X11 forwarding.");
2552 error("deny_input_open: type %d plen %d", type, plen);
2555 error("Warning: this is probably a break in attempt by a malicious server.");
2556 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2557 packet_put_int(rchan);
2562 * Requests forwarding of X11 connections, generates fake authentication
2563 * data, and enables authentication spoofing.
2567 x11_request_forwarding_with_spoofing(int client_session_id,
2568 const char *proto, const char *data)
2570 u_int data_len = (u_int) strlen(data) / 2;
2571 u_int i, value, len;
2577 cp = getenv("DISPLAY");
2579 cp = strchr(cp, ':');
2581 cp = strchr(cp, '.');
2583 screen_number = atoi(cp + 1);
2587 /* Save protocol name. */
2588 x11_saved_proto = xstrdup(proto);
2591 * Extract real authentication data and generate fake data of the
2594 x11_saved_data = xmalloc(data_len);
2595 x11_fake_data = xmalloc(data_len);
2596 for (i = 0; i < data_len; i++) {
2597 if (sscanf(data + 2 * i, "%2x", &value) != 1)
2598 fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2600 rand = arc4random();
2601 x11_saved_data[i] = value;
2602 x11_fake_data[i] = rand & 0xff;
2605 x11_saved_data_len = data_len;
2606 x11_fake_data_len = data_len;
2608 /* Convert the fake data into hex. */
2609 len = 2 * data_len + 1;
2610 new_data = xmalloc(len);
2611 for (i = 0; i < data_len; i++)
2612 snprintf(new_data + 2 * i, len - 2 * i,
2613 "%02x", (u_char) x11_fake_data[i]);
2615 /* Send the request packet. */
2617 channel_request_start(client_session_id, "x11-req", 0);
2618 packet_put_char(0); /* XXX bool single connection */
2620 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2622 packet_put_cstring(proto);
2623 packet_put_cstring(new_data);
2624 packet_put_int(screen_number);
2626 packet_write_wait();
2630 /* Sends a message to the server to request authentication fd forwarding. */
2633 auth_request_forwarding()
2635 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2637 packet_write_wait();
2641 * Returns the name of the forwarded authentication socket. Returns NULL if
2642 * there is no forwarded authentication socket. The returned value points to
2647 auth_get_socket_name()
2649 return channel_forwarded_auth_socket_name;
2652 /* removes the agent forwarding socket */
2655 cleanup_socket(void)
2657 unlink(channel_forwarded_auth_socket_name);
2658 rmdir(channel_forwarded_auth_socket_dir);
2662 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
2663 * This starts forwarding authentication requests.
2667 auth_input_request_forwarding(struct passwd * pw)
2671 struct sockaddr_un sunaddr;
2673 if (auth_get_socket_name() != NULL)
2674 fatal("Protocol error: authentication forwarding requested twice.");
2676 /* Temporarily drop privileged uid for mkdir/bind. */
2677 temporarily_use_uid(pw);
2679 /* Allocate a buffer for the socket name, and format the name. */
2680 channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2681 channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2682 strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2684 /* Create private directory for socket */
2685 if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2686 packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2689 xfree(channel_forwarded_auth_socket_name);
2690 xfree(channel_forwarded_auth_socket_dir);
2691 channel_forwarded_auth_socket_name = NULL;
2692 channel_forwarded_auth_socket_dir = NULL;
2695 snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2696 channel_forwarded_auth_socket_dir, (int) getpid());
2698 if (atexit(cleanup_socket) < 0) {
2701 packet_disconnect("socket: %.100s", strerror(saved));
2703 /* Create the socket. */
2704 sock = socket(AF_UNIX, SOCK_STREAM, 0);
2706 packet_disconnect("socket: %.100s", strerror(errno));
2708 /* Bind it to the name. */
2709 memset(&sunaddr, 0, sizeof(sunaddr));
2710 sunaddr.sun_family = AF_UNIX;
2711 strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2712 sizeof(sunaddr.sun_path));
2714 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2715 packet_disconnect("bind: %.100s", strerror(errno));
2717 /* Restore the privileged uid. */
2720 /* Start listening on the socket. */
2721 if (listen(sock, 5) < 0)
2722 packet_disconnect("listen: %.100s", strerror(errno));
2724 /* Allocate a channel for the authentication agent socket. */
2725 nc = channel_new("auth socket",
2726 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2727 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2728 0, xstrdup("auth socket"), 1);
2730 error("auth_input_request_forwarding: channel_new failed");
2734 strlcpy(nc->path, channel_forwarded_auth_socket_name, sizeof(nc->path));
2738 /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2741 auth_input_open_request(int type, int plen, void *ctxt)
2744 int remote_id, sock;
2747 packet_integrity_check(plen, 4, type);
2749 /* Read the remote channel number from the message. */
2750 remote_id = packet_get_int();
2753 * Get a connection to the local authentication agent (this may again
2756 sock = ssh_get_authentication_socket();
2759 * If we could not connect the agent, send an error message back to
2760 * the server. This should never happen unless the agent dies,
2761 * because authentication forwarding is only enabled if we have an
2765 dummyname = xstrdup("authentication agent connection");
2766 c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1);
2768 error("auth_input_open_request: channel_new failed");
2771 c->remote_id = remote_id;
2775 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2776 packet_put_int(remote_id);
2778 /* Send a confirmation to the remote host. */
2779 debug("Forwarding authentication connection.");
2780 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2781 packet_put_int(remote_id);
2782 packet_put_int(c->self);
2788 channel_start_open(int id)
2790 Channel *c = channel_lookup(id);
2792 log("channel_open: %d: bad id", id);
2795 debug("send channel open %d", id);
2796 packet_start(SSH2_MSG_CHANNEL_OPEN);
2797 packet_put_cstring(c->ctype);
2798 packet_put_int(c->self);
2799 packet_put_int(c->local_window);
2800 packet_put_int(c->local_maxpacket);
2803 channel_open(int id)
2806 channel_start_open(id);
2810 channel_request(int id, char *service, int wantconfirm)
2812 channel_request_start(id, service, wantconfirm);
2814 debug("channel request %d: %s", id, service) ;
2817 channel_request_start(int id, char *service, int wantconfirm)
2819 Channel *c = channel_lookup(id);
2821 log("channel_request: %d: bad id", id);
2824 packet_start(SSH2_MSG_CHANNEL_REQUEST);
2825 packet_put_int(c->remote_id);
2826 packet_put_cstring(service);
2827 packet_put_char(wantconfirm);
2830 channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2832 Channel *c = channel_lookup(id);
2834 log("channel_register_callback: %d: bad id", id);
2837 c->cb_event = mtype;
2842 channel_register_cleanup(int id, channel_callback_fn *fn)
2844 Channel *c = channel_lookup(id);
2846 log("channel_register_cleanup: %d: bad id", id);
2849 c->dettach_user = fn;
2852 channel_cancel_cleanup(int id)
2854 Channel *c = channel_lookup(id);
2856 log("channel_cancel_cleanup: %d: bad id", id);
2859 c->dettach_user = NULL;
2862 channel_register_filter(int id, channel_filter_fn *fn)
2864 Channel *c = channel_lookup(id);
2866 log("channel_register_filter: %d: bad id", id);
2869 c->input_filter = fn;
2873 channel_set_fds(int id, int rfd, int wfd, int efd,
2874 int extusage, int nonblock)
2876 Channel *c = channel_lookup(id);
2877 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2878 fatal("channel_activate for non-larval channel %d.", id);
2879 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
2880 c->type = SSH_CHANNEL_OPEN;
2881 /* XXX window size? */
2882 c->local_window = c->local_window_max = c->local_maxpacket * 2;
2883 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2884 packet_put_int(c->remote_id);
2885 packet_put_int(c->local_window);