1 /* $OpenBSD: channels.c,v 1.310 2010/11/24 01:24:14 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * This file contains functions for generic socket connection forwarding.
7 * There is also code for initiating connection forwarding for X11 connections,
8 * arbitrary tcp/ip connections, and the authentication agent connection.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 support added by Markus Friedl.
17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Copyright (c) 1999 Dug Song. All rights reserved.
19 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 #include <sys/types.h>
45 #include <sys/ioctl.h>
47 #include <sys/socket.h>
48 #ifdef HAVE_SYS_TIME_H
49 # include <sys/time.h>
52 #include <netinet/in.h>
53 #include <arpa/inet.h>
65 #include "openbsd-compat/sys-queue.h"
79 #include "pathnames.h"
84 * Pointer to an array containing all allocated channels. The array is
85 * dynamically extended as needed.
87 static Channel **channels = NULL;
90 * Size of the channel array. All slots of the array must always be
91 * initialized (at least the type field); unused slots set to NULL
93 static u_int channels_alloc = 0;
96 * Maximum file descriptor value used in any of the channels. This is
97 * updated in channel_new.
99 static int channel_max_fd = 0;
102 /* -- tcp forwarding */
105 * Data structure for storing which hosts are permitted for forward requests.
106 * The local sides of any remote forwards are stored in this array to prevent
107 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
108 * network (which might be behind a firewall).
111 char *host_to_connect; /* Connect to 'host'. */
112 u_short port_to_connect; /* Connect to 'port'. */
113 u_short listen_port; /* Remote side should listen port number. */
116 /* List of all permitted host/port pairs to connect by the user. */
117 static ForwardPermission *permitted_opens = NULL;
119 /* List of all permitted host/port pairs to connect by the admin. */
120 static ForwardPermission *permitted_adm_opens = NULL;
122 /* Number of permitted host/port pairs in the array permitted by the user. */
123 static int num_permitted_opens = 0;
125 /* Number of permitted host/port pair in the array permitted by the admin. */
126 static int num_adm_permitted_opens = 0;
129 * If this is true, all opens are permitted. This is the case on the server
130 * on which we have to trust the client anyway, and the user could do
131 * anything after logging in anyway.
133 static int all_opens_permitted = 0;
136 /* -- X11 forwarding */
138 /* Maximum number of fake X11 displays to try. */
139 #define MAX_DISPLAYS 1000
141 /* Saved X11 local (client) display. */
142 static char *x11_saved_display = NULL;
144 /* Saved X11 authentication protocol name. */
145 static char *x11_saved_proto = NULL;
147 /* Saved X11 authentication data. This is the real data. */
148 static char *x11_saved_data = NULL;
149 static u_int x11_saved_data_len = 0;
152 * Fake X11 authentication data. This is what the server will be sending us;
153 * we should replace any occurrences of this by the real data.
155 static u_char *x11_fake_data = NULL;
156 static u_int x11_fake_data_len;
159 /* -- agent forwarding */
163 /* AF_UNSPEC or AF_INET or AF_INET6 */
164 static int IPv4or6 = AF_UNSPEC;
167 static void port_open_helper(Channel *c, char *rtype);
169 /* non-blocking connect helpers */
170 static int connect_next(struct channel_connect *);
171 static void channel_connect_ctx_free(struct channel_connect *);
174 static int hpn_disabled = 0;
175 static int hpn_buffer_size = 2 * 1024 * 1024;
177 /* -- channel core */
182 channel_by_id(int id)
186 if (id < 0 || (u_int)id >= channels_alloc) {
187 logit("channel_by_id: %d: bad id", id);
192 logit("channel_by_id: %d: bad id: channel free", id);
199 * Returns the channel if it is allowed to receive protocol messages.
200 * Private channels, like listening sockets, may not receive messages.
203 channel_lookup(int id)
207 if ((c = channel_by_id(id)) == NULL)
211 case SSH_CHANNEL_X11_OPEN:
212 case SSH_CHANNEL_LARVAL:
213 case SSH_CHANNEL_CONNECTING:
214 case SSH_CHANNEL_DYNAMIC:
215 case SSH_CHANNEL_OPENING:
216 case SSH_CHANNEL_OPEN:
217 case SSH_CHANNEL_INPUT_DRAINING:
218 case SSH_CHANNEL_OUTPUT_DRAINING:
221 logit("Non-public channel %d, type %d.", id, c->type);
226 * Register filedescriptors for a channel, used when allocating a channel or
227 * when the channel consumer/producer is ready, e.g. shell exec'd
230 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
231 int extusage, int nonblock, int is_tty)
233 /* Update the maximum file descriptor value. */
234 channel_max_fd = MAX(channel_max_fd, rfd);
235 channel_max_fd = MAX(channel_max_fd, wfd);
236 channel_max_fd = MAX(channel_max_fd, efd);
239 fcntl(rfd, F_SETFD, FD_CLOEXEC);
240 if (wfd != -1 && wfd != rfd)
241 fcntl(wfd, F_SETFD, FD_CLOEXEC);
242 if (efd != -1 && efd != rfd && efd != wfd)
243 fcntl(efd, F_SETFD, FD_CLOEXEC);
247 c->sock = (rfd == wfd) ? rfd : -1;
249 c->extended_usage = extusage;
251 if ((c->isatty = is_tty) != 0)
252 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
253 c->wfd_isatty = is_tty || isatty(c->wfd);
255 /* enable nonblocking mode */
267 * Allocate a new channel object and set its type and socket. This will cause
268 * remote_name to be freed.
271 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
272 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
278 /* Do initial allocation if this is the first call. */
279 if (channels_alloc == 0) {
281 channels = xcalloc(channels_alloc, sizeof(Channel *));
282 for (i = 0; i < channels_alloc; i++)
285 /* Try to find a free slot where to put the new channel. */
286 for (found = -1, i = 0; i < channels_alloc; i++)
287 if (channels[i] == NULL) {
288 /* Found a free slot. */
293 /* There are no free slots. Take last+1 slot and expand the array. */
294 found = channels_alloc;
295 if (channels_alloc > 10000)
296 fatal("channel_new: internal error: channels_alloc %d "
297 "too big.", channels_alloc);
298 channels = xrealloc(channels, channels_alloc + 10,
300 channels_alloc += 10;
301 debug2("channel: expanding %d", channels_alloc);
302 for (i = found; i < channels_alloc; i++)
305 /* Initialize and return new channel. */
306 c = channels[found] = xcalloc(1, sizeof(Channel));
307 buffer_init(&c->input);
308 buffer_init(&c->output);
309 buffer_init(&c->extended);
311 c->ostate = CHAN_OUTPUT_OPEN;
312 c->istate = CHAN_INPUT_OPEN;
314 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
318 c->local_window = window;
319 c->local_window_max = window;
320 c->local_consumed = 0;
321 c->local_maxpacket = maxpack;
322 c->dynamic_window = 0;
324 c->remote_name = xstrdup(remote_name);
325 c->remote_window = 0;
326 c->remote_maxpacket = 0;
328 c->single_connection = 0;
329 c->detach_user = NULL;
331 c->open_confirm = NULL;
332 c->open_confirm_ctx = NULL;
333 c->input_filter = NULL;
334 c->output_filter = NULL;
335 c->filter_ctx = NULL;
336 c->filter_cleanup = NULL;
341 c->delayed = 1; /* prevent call to channel_post handler */
342 TAILQ_INIT(&c->status_confirms);
343 debug("channel %d: new [%s]", found, remote_name);
348 channel_find_maxfd(void)
354 for (i = 0; i < channels_alloc; i++) {
357 max = MAX(max, c->rfd);
358 max = MAX(max, c->wfd);
359 max = MAX(max, c->efd);
366 channel_close_fd(int *fdp)
368 int ret = 0, fd = *fdp;
373 if (fd == channel_max_fd)
374 channel_max_fd = channel_find_maxfd();
379 /* Close all channel fd/socket. */
381 channel_close_fds(Channel *c)
383 channel_close_fd(&c->sock);
384 channel_close_fd(&c->rfd);
385 channel_close_fd(&c->wfd);
386 channel_close_fd(&c->efd);
389 /* Free the channel and close its fd/socket. */
391 channel_free(Channel *c)
395 struct channel_confirm *cc;
397 for (n = 0, i = 0; i < channels_alloc; i++)
400 debug("channel %d: free: %s, nchannels %u", c->self,
401 c->remote_name ? c->remote_name : "???", n);
403 s = channel_open_message();
404 debug3("channel %d: status: %s", c->self, s);
408 shutdown(c->sock, SHUT_RDWR);
409 channel_close_fds(c);
410 buffer_free(&c->input);
411 buffer_free(&c->output);
412 buffer_free(&c->extended);
413 if (c->remote_name) {
414 xfree(c->remote_name);
415 c->remote_name = NULL;
421 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
422 if (cc->abandon_cb != NULL)
423 cc->abandon_cb(c, cc->ctx);
424 TAILQ_REMOVE(&c->status_confirms, cc, entry);
425 bzero(cc, sizeof(*cc));
428 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
429 c->filter_cleanup(c->self, c->filter_ctx);
430 channels[c->self] = NULL;
435 channel_free_all(void)
439 for (i = 0; i < channels_alloc; i++)
440 if (channels[i] != NULL)
441 channel_free(channels[i]);
445 * Closes the sockets/fds of all channels. This is used to close extra file
446 * descriptors after a fork.
449 channel_close_all(void)
453 for (i = 0; i < channels_alloc; i++)
454 if (channels[i] != NULL)
455 channel_close_fds(channels[i]);
459 * Stop listening to channels.
462 channel_stop_listening(void)
467 for (i = 0; i < channels_alloc; i++) {
471 case SSH_CHANNEL_AUTH_SOCKET:
472 case SSH_CHANNEL_PORT_LISTENER:
473 case SSH_CHANNEL_RPORT_LISTENER:
474 case SSH_CHANNEL_X11_LISTENER:
475 channel_close_fd(&c->sock);
484 * Returns true if no channel has too much buffered data, and false if one or
485 * more channel is overfull.
488 channel_not_very_much_buffered_data(void)
493 for (i = 0; i < channels_alloc; i++) {
495 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
498 buffer_len(&c->input) > packet_get_maxsize()) {
499 debug2("channel %d: big input buffer %d",
500 c->self, buffer_len(&c->input));
504 if (buffer_len(&c->output) > packet_get_maxsize()) {
505 debug2("channel %d: big output buffer %u > %u",
506 c->self, buffer_len(&c->output),
507 packet_get_maxsize());
515 /* Returns true if any channel is still open. */
517 channel_still_open(void)
522 for (i = 0; i < channels_alloc; i++) {
527 case SSH_CHANNEL_X11_LISTENER:
528 case SSH_CHANNEL_PORT_LISTENER:
529 case SSH_CHANNEL_RPORT_LISTENER:
530 case SSH_CHANNEL_MUX_LISTENER:
531 case SSH_CHANNEL_CLOSED:
532 case SSH_CHANNEL_AUTH_SOCKET:
533 case SSH_CHANNEL_DYNAMIC:
534 case SSH_CHANNEL_CONNECTING:
535 case SSH_CHANNEL_ZOMBIE:
537 case SSH_CHANNEL_LARVAL:
539 fatal("cannot happen: SSH_CHANNEL_LARVAL");
541 case SSH_CHANNEL_OPENING:
542 case SSH_CHANNEL_OPEN:
543 case SSH_CHANNEL_X11_OPEN:
544 case SSH_CHANNEL_MUX_CLIENT:
546 case SSH_CHANNEL_INPUT_DRAINING:
547 case SSH_CHANNEL_OUTPUT_DRAINING:
549 fatal("cannot happen: OUT_DRAIN");
552 fatal("channel_still_open: bad channel type %d", c->type);
559 /* Returns the id of an open channel suitable for keepaliving */
561 channel_find_open(void)
566 for (i = 0; i < channels_alloc; i++) {
568 if (c == NULL || c->remote_id < 0)
571 case SSH_CHANNEL_CLOSED:
572 case SSH_CHANNEL_DYNAMIC:
573 case SSH_CHANNEL_X11_LISTENER:
574 case SSH_CHANNEL_PORT_LISTENER:
575 case SSH_CHANNEL_RPORT_LISTENER:
576 case SSH_CHANNEL_MUX_LISTENER:
577 case SSH_CHANNEL_MUX_CLIENT:
578 case SSH_CHANNEL_OPENING:
579 case SSH_CHANNEL_CONNECTING:
580 case SSH_CHANNEL_ZOMBIE:
582 case SSH_CHANNEL_LARVAL:
583 case SSH_CHANNEL_AUTH_SOCKET:
584 case SSH_CHANNEL_OPEN:
585 case SSH_CHANNEL_X11_OPEN:
587 case SSH_CHANNEL_INPUT_DRAINING:
588 case SSH_CHANNEL_OUTPUT_DRAINING:
590 fatal("cannot happen: OUT_DRAIN");
593 fatal("channel_find_open: bad channel type %d", c->type);
602 * Returns a message describing the currently open forwarded connections,
603 * suitable for sending to the client. The message contains crlf pairs for
607 channel_open_message(void)
614 buffer_init(&buffer);
615 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
616 buffer_append(&buffer, buf, strlen(buf));
617 for (i = 0; i < channels_alloc; i++) {
622 case SSH_CHANNEL_X11_LISTENER:
623 case SSH_CHANNEL_PORT_LISTENER:
624 case SSH_CHANNEL_RPORT_LISTENER:
625 case SSH_CHANNEL_CLOSED:
626 case SSH_CHANNEL_AUTH_SOCKET:
627 case SSH_CHANNEL_ZOMBIE:
628 case SSH_CHANNEL_MUX_CLIENT:
629 case SSH_CHANNEL_MUX_LISTENER:
631 case SSH_CHANNEL_LARVAL:
632 case SSH_CHANNEL_OPENING:
633 case SSH_CHANNEL_CONNECTING:
634 case SSH_CHANNEL_DYNAMIC:
635 case SSH_CHANNEL_OPEN:
636 case SSH_CHANNEL_X11_OPEN:
637 case SSH_CHANNEL_INPUT_DRAINING:
638 case SSH_CHANNEL_OUTPUT_DRAINING:
639 snprintf(buf, sizeof buf,
640 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
641 c->self, c->remote_name,
642 c->type, c->remote_id,
643 c->istate, buffer_len(&c->input),
644 c->ostate, buffer_len(&c->output),
645 c->rfd, c->wfd, c->ctl_chan);
646 buffer_append(&buffer, buf, strlen(buf));
649 fatal("channel_open_message: bad channel type %d", c->type);
653 buffer_append(&buffer, "\0", 1);
654 cp = xstrdup(buffer_ptr(&buffer));
655 buffer_free(&buffer);
660 channel_send_open(int id)
662 Channel *c = channel_lookup(id);
665 logit("channel_send_open: %d: bad id", id);
668 debug2("channel %d: send open", id);
669 packet_start(SSH2_MSG_CHANNEL_OPEN);
670 packet_put_cstring(c->ctype);
671 packet_put_int(c->self);
672 packet_put_int(c->local_window);
673 packet_put_int(c->local_maxpacket);
678 channel_request_start(int id, char *service, int wantconfirm)
680 Channel *c = channel_lookup(id);
683 logit("channel_request_start: %d: unknown channel id", id);
686 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
687 packet_start(SSH2_MSG_CHANNEL_REQUEST);
688 packet_put_int(c->remote_id);
689 packet_put_cstring(service);
690 packet_put_char(wantconfirm);
694 channel_register_status_confirm(int id, channel_confirm_cb *cb,
695 channel_confirm_abandon_cb *abandon_cb, void *ctx)
697 struct channel_confirm *cc;
700 if ((c = channel_lookup(id)) == NULL)
701 fatal("channel_register_expect: %d: bad id", id);
703 cc = xmalloc(sizeof(*cc));
705 cc->abandon_cb = abandon_cb;
707 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
711 channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
713 Channel *c = channel_lookup(id);
716 logit("channel_register_open_confirm: %d: bad id", id);
719 c->open_confirm = fn;
720 c->open_confirm_ctx = ctx;
724 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
726 Channel *c = channel_by_id(id);
729 logit("channel_register_cleanup: %d: bad id", id);
733 c->detach_close = do_close;
737 channel_cancel_cleanup(int id)
739 Channel *c = channel_by_id(id);
742 logit("channel_cancel_cleanup: %d: bad id", id);
745 c->detach_user = NULL;
750 channel_register_filter(int id, channel_infilter_fn *ifn,
751 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
753 Channel *c = channel_lookup(id);
756 logit("channel_register_filter: %d: bad id", id);
759 c->input_filter = ifn;
760 c->output_filter = ofn;
762 c->filter_cleanup = cfn;
766 channel_set_fds(int id, int rfd, int wfd, int efd,
767 int extusage, int nonblock, int is_tty, u_int window_max)
769 Channel *c = channel_lookup(id);
771 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
772 fatal("channel_activate for non-larval channel %d.", id);
773 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
774 c->type = SSH_CHANNEL_OPEN;
775 c->local_window = c->local_window_max = window_max;
776 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
777 packet_put_int(c->remote_id);
778 packet_put_int(c->local_window);
783 * 'channel_pre*' are called just before select() to add any bits relevant to
784 * channels in the select bitmasks.
787 * 'channel_post*': perform any appropriate operations for channels which
788 * have events pending.
790 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
791 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
792 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
796 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
798 FD_SET(c->sock, readset);
803 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
805 debug3("channel %d: waiting for connection", c->self);
806 FD_SET(c->sock, writeset);
810 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
812 if (buffer_len(&c->input) < packet_get_maxsize())
813 FD_SET(c->sock, readset);
814 if (buffer_len(&c->output) > 0)
815 FD_SET(c->sock, writeset);
818 int channel_tcpwinsz () {
819 u_int32_t tcpwinsz = 0;
820 socklen_t optsz = sizeof(tcpwinsz);
823 /* if we aren't on a socket return 128KB*/
824 if(!packet_connection_is_on_socket())
826 ret = getsockopt(packet_get_connection_in(),
827 SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
828 /* return no more than 64MB */
829 if ((ret == 0) && tcpwinsz > BUFFER_MAX_LEN_HPN)
830 tcpwinsz = BUFFER_MAX_LEN_HPN;
831 debug2("tcpwinsz: %d for connection: %d", tcpwinsz,
832 packet_get_connection_in());
837 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
839 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
841 /* check buffer limits */
842 if ((!c->tcpwinsz) || (c->dynamic_window > 0))
843 c->tcpwinsz = channel_tcpwinsz();
845 limit = MIN(limit, 2 * c->tcpwinsz);
847 if (c->istate == CHAN_INPUT_OPEN &&
849 buffer_len(&c->input) < limit &&
850 buffer_check_alloc(&c->input, CHAN_RBUF))
851 FD_SET(c->rfd, readset);
852 if (c->ostate == CHAN_OUTPUT_OPEN ||
853 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
854 if (buffer_len(&c->output) > 0) {
855 FD_SET(c->wfd, writeset);
856 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
857 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
858 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
859 c->self, c->efd, buffer_len(&c->extended));
864 /** XXX check close conditions, too */
865 if (compat20 && c->efd != -1 &&
866 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
867 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
868 buffer_len(&c->extended) > 0)
869 FD_SET(c->efd, writeset);
870 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
871 (c->extended_usage == CHAN_EXTENDED_READ ||
872 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
873 buffer_len(&c->extended) < c->remote_window)
874 FD_SET(c->efd, readset);
876 /* XXX: What about efd? races? */
881 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
883 if (buffer_len(&c->input) == 0) {
884 packet_start(SSH_MSG_CHANNEL_CLOSE);
885 packet_put_int(c->remote_id);
887 c->type = SSH_CHANNEL_CLOSED;
888 debug2("channel %d: closing after input drain.", c->self);
894 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
896 if (buffer_len(&c->output) == 0)
899 FD_SET(c->sock, writeset);
903 * This is a special state for X11 authentication spoofing. An opened X11
904 * connection (when authentication spoofing is being done) remains in this
905 * state until the first packet has been completely read. The authentication
906 * data in that packet is then substituted by the real data if it matches the
907 * fake data, and the channel is put into normal mode.
908 * XXX All this happens at the client side.
909 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
912 x11_open_helper(Buffer *b)
915 u_int proto_len, data_len;
917 /* Check if the fixed size part of the packet is in buffer. */
918 if (buffer_len(b) < 12)
921 /* Parse the lengths of variable-length fields. */
923 if (ucp[0] == 0x42) { /* Byte order MSB first. */
924 proto_len = 256 * ucp[6] + ucp[7];
925 data_len = 256 * ucp[8] + ucp[9];
926 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
927 proto_len = ucp[6] + 256 * ucp[7];
928 data_len = ucp[8] + 256 * ucp[9];
930 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
935 /* Check if the whole packet is in buffer. */
937 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
940 /* Check if authentication protocol matches. */
941 if (proto_len != strlen(x11_saved_proto) ||
942 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
943 debug2("X11 connection uses different authentication protocol.");
946 /* Check if authentication data matches our fake data. */
947 if (data_len != x11_fake_data_len ||
948 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
949 x11_fake_data, x11_fake_data_len) != 0) {
950 debug2("X11 auth data does not match fake data.");
953 /* Check fake data length */
954 if (x11_fake_data_len != x11_saved_data_len) {
955 error("X11 fake_data_len %d != saved_data_len %d",
956 x11_fake_data_len, x11_saved_data_len);
960 * Received authentication protocol and data match
961 * our fake data. Substitute the fake data with real
964 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
965 x11_saved_data, x11_saved_data_len);
970 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
972 int ret = x11_open_helper(&c->output);
975 /* Start normal processing for the channel. */
976 c->type = SSH_CHANNEL_OPEN;
977 channel_pre_open_13(c, readset, writeset);
978 } else if (ret == -1) {
980 * We have received an X11 connection that has bad
981 * authentication information.
983 logit("X11 connection rejected because of wrong authentication.");
984 buffer_clear(&c->input);
985 buffer_clear(&c->output);
986 channel_close_fd(&c->sock);
988 c->type = SSH_CHANNEL_CLOSED;
989 packet_start(SSH_MSG_CHANNEL_CLOSE);
990 packet_put_int(c->remote_id);
996 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
998 int ret = x11_open_helper(&c->output);
1000 /* c->force_drain = 1; */
1003 c->type = SSH_CHANNEL_OPEN;
1004 channel_pre_open(c, readset, writeset);
1005 } else if (ret == -1) {
1006 logit("X11 connection rejected because of wrong authentication.");
1007 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1008 chan_read_failed(c);
1009 buffer_clear(&c->input);
1011 buffer_clear(&c->output);
1012 /* for proto v1, the peer will send an IEOF */
1014 chan_write_failed(c);
1016 c->type = SSH_CHANNEL_OPEN;
1017 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1022 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1024 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1025 buffer_check_alloc(&c->input, CHAN_RBUF))
1026 FD_SET(c->rfd, readset);
1027 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1028 /* clear buffer immediately (discard any partial packet) */
1029 buffer_clear(&c->input);
1031 /* Start output drain. XXX just kill chan? */
1032 chan_rcvd_oclose(c);
1034 if (c->ostate == CHAN_OUTPUT_OPEN ||
1035 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1036 if (buffer_len(&c->output) > 0)
1037 FD_SET(c->wfd, writeset);
1038 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1043 /* try to decode a socks4 header */
1046 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1049 u_int len, have, i, found, need;
1054 u_int16_t dest_port;
1055 struct in_addr dest_addr;
1058 debug2("channel %d: decode socks4", c->self);
1060 have = buffer_len(&c->input);
1061 len = sizeof(s4_req);
1064 p = buffer_ptr(&c->input);
1067 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1068 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1069 debug2("channel %d: socks4a request", c->self);
1070 /* ... and needs an extra string (the hostname) */
1073 /* Check for terminating NUL on the string(s) */
1074 for (found = 0, i = len; i < have; i++) {
1081 /* the peer is probably sending garbage */
1082 debug("channel %d: decode socks4: too long",
1089 buffer_get(&c->input, (char *)&s4_req.version, 1);
1090 buffer_get(&c->input, (char *)&s4_req.command, 1);
1091 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1092 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1093 have = buffer_len(&c->input);
1094 p = buffer_ptr(&c->input);
1096 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1097 len++; /* trailing '\0' */
1099 fatal("channel %d: decode socks4: len %d > have %d",
1100 c->self, len, have);
1101 strlcpy(username, p, sizeof(username));
1102 buffer_consume(&c->input, len);
1104 if (c->path != NULL) {
1108 if (need == 1) { /* SOCKS4: one string */
1109 host = inet_ntoa(s4_req.dest_addr);
1110 c->path = xstrdup(host);
1111 } else { /* SOCKS4A: two strings */
1112 have = buffer_len(&c->input);
1113 p = buffer_ptr(&c->input);
1115 debug2("channel %d: decode socks4a: host %s/%d",
1117 len++; /* trailing '\0' */
1119 fatal("channel %d: decode socks4a: len %d > have %d",
1120 c->self, len, have);
1121 if (len > NI_MAXHOST) {
1122 error("channel %d: hostname \"%.100s\" too long",
1126 c->path = xstrdup(p);
1127 buffer_consume(&c->input, len);
1129 c->host_port = ntohs(s4_req.dest_port);
1131 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1132 c->self, c->path, c->host_port, s4_req.command);
1134 if (s4_req.command != 1) {
1135 debug("channel %d: cannot handle: %s cn %d",
1136 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1139 s4_rsp.version = 0; /* vn: 0 for reply */
1140 s4_rsp.command = 90; /* cd: req granted */
1141 s4_rsp.dest_port = 0; /* ignored */
1142 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1143 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1147 /* try to decode a socks5 header */
1148 #define SSH_SOCKS5_AUTHDONE 0x1000
1149 #define SSH_SOCKS5_NOAUTH 0x00
1150 #define SSH_SOCKS5_IPV4 0x01
1151 #define SSH_SOCKS5_DOMAIN 0x03
1152 #define SSH_SOCKS5_IPV6 0x04
1153 #define SSH_SOCKS5_CONNECT 0x01
1154 #define SSH_SOCKS5_SUCCESS 0x00
1158 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1166 u_int16_t dest_port;
1167 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1168 u_int have, need, i, found, nmethods, addrlen, af;
1170 debug2("channel %d: decode socks5", c->self);
1171 p = buffer_ptr(&c->input);
1174 have = buffer_len(&c->input);
1175 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1176 /* format: ver | nmethods | methods */
1180 if (have < nmethods + 2)
1182 /* look for method: "NO AUTHENTICATION REQUIRED" */
1183 for (found = 0, i = 2; i < nmethods + 2; i++) {
1184 if (p[i] == SSH_SOCKS5_NOAUTH) {
1190 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1194 buffer_consume(&c->input, nmethods + 2);
1195 buffer_put_char(&c->output, 0x05); /* version */
1196 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1197 FD_SET(c->sock, writeset);
1198 c->flags |= SSH_SOCKS5_AUTHDONE;
1199 debug2("channel %d: socks5 auth done", c->self);
1200 return 0; /* need more */
1202 debug2("channel %d: socks5 post auth", c->self);
1203 if (have < sizeof(s5_req)+1)
1204 return 0; /* need more */
1205 memcpy(&s5_req, p, sizeof(s5_req));
1206 if (s5_req.version != 0x05 ||
1207 s5_req.command != SSH_SOCKS5_CONNECT ||
1208 s5_req.reserved != 0x00) {
1209 debug2("channel %d: only socks5 connect supported", c->self);
1212 switch (s5_req.atyp){
1213 case SSH_SOCKS5_IPV4:
1217 case SSH_SOCKS5_DOMAIN:
1218 addrlen = p[sizeof(s5_req)];
1221 case SSH_SOCKS5_IPV6:
1226 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1229 need = sizeof(s5_req) + addrlen + 2;
1230 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1234 buffer_consume(&c->input, sizeof(s5_req));
1235 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1236 buffer_consume(&c->input, 1); /* host string length */
1237 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1238 buffer_get(&c->input, (char *)&dest_port, 2);
1239 dest_addr[addrlen] = '\0';
1240 if (c->path != NULL) {
1244 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1245 if (addrlen >= NI_MAXHOST) {
1246 error("channel %d: dynamic request: socks5 hostname "
1247 "\"%.100s\" too long", c->self, dest_addr);
1250 c->path = xstrdup(dest_addr);
1252 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1254 c->path = xstrdup(ntop);
1256 c->host_port = ntohs(dest_port);
1258 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1259 c->self, c->path, c->host_port, s5_req.command);
1261 s5_rsp.version = 0x05;
1262 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1263 s5_rsp.reserved = 0; /* ignored */
1264 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1265 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1266 dest_port = 0; /* ignored */
1268 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1269 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1270 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1275 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1280 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1283 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1284 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1285 0, "stdio-forward", /*nonblock*/0);
1287 c->path = xstrdup(host_to_connect);
1288 c->host_port = port_to_connect;
1289 c->listening_port = 0;
1292 channel_register_fds(c, in, out, -1, 0, 1, 0);
1293 port_open_helper(c, "direct-tcpip");
1298 /* dynamic port forwarding */
1300 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1306 have = buffer_len(&c->input);
1307 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1308 /* buffer_dump(&c->input); */
1309 /* check if the fixed size part of the packet is in buffer. */
1312 FD_SET(c->sock, readset);
1315 /* try to guess the protocol */
1316 p = buffer_ptr(&c->input);
1319 ret = channel_decode_socks4(c, readset, writeset);
1322 ret = channel_decode_socks5(c, readset, writeset);
1330 } else if (ret == 0) {
1331 debug2("channel %d: pre_dynamic: need more", c->self);
1333 FD_SET(c->sock, readset);
1335 /* switch to the next state */
1336 c->type = SSH_CHANNEL_OPENING;
1337 port_open_helper(c, "direct-tcpip");
1341 /* This is our fake X11 server socket. */
1344 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1347 struct sockaddr_storage addr;
1350 char buf[16384], *remote_ipaddr;
1353 if (FD_ISSET(c->sock, readset)) {
1354 debug("X11 connection requested.");
1355 addrlen = sizeof(addr);
1356 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1357 if (c->single_connection) {
1358 debug2("single_connection: closing X11 listener.");
1359 channel_close_fd(&c->sock);
1363 error("accept: %.100s", strerror(errno));
1366 set_nodelay(newsock);
1367 remote_ipaddr = get_peer_ipaddr(newsock);
1368 remote_port = get_peer_port(newsock);
1369 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1370 remote_ipaddr, remote_port);
1372 nc = channel_new("accepted x11 socket",
1373 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1374 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1376 packet_start(SSH2_MSG_CHANNEL_OPEN);
1377 packet_put_cstring("x11");
1378 packet_put_int(nc->self);
1379 packet_put_int(nc->local_window_max);
1380 packet_put_int(nc->local_maxpacket);
1381 /* originator ipaddr and port */
1382 packet_put_cstring(remote_ipaddr);
1383 if (datafellows & SSH_BUG_X11FWD) {
1384 debug2("ssh2 x11 bug compat mode");
1386 packet_put_int(remote_port);
1390 packet_start(SSH_SMSG_X11_OPEN);
1391 packet_put_int(nc->self);
1392 if (packet_get_protocol_flags() &
1393 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1394 packet_put_cstring(buf);
1397 xfree(remote_ipaddr);
1402 port_open_helper(Channel *c, char *rtype)
1406 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1407 int remote_port = get_peer_port(c->sock);
1409 if (remote_port == -1) {
1410 /* Fake addr/port to appease peers that validate it (Tectia) */
1411 xfree(remote_ipaddr);
1412 remote_ipaddr = xstrdup("127.0.0.1");
1413 remote_port = 65535;
1416 direct = (strcmp(rtype, "direct-tcpip") == 0);
1418 snprintf(buf, sizeof buf,
1419 "%s: listening port %d for %.100s port %d, "
1420 "connect from %.200s port %d",
1421 rtype, c->listening_port, c->path, c->host_port,
1422 remote_ipaddr, remote_port);
1424 xfree(c->remote_name);
1425 c->remote_name = xstrdup(buf);
1428 packet_start(SSH2_MSG_CHANNEL_OPEN);
1429 packet_put_cstring(rtype);
1430 packet_put_int(c->self);
1431 packet_put_int(c->local_window_max);
1432 packet_put_int(c->local_maxpacket);
1434 /* target host, port */
1435 packet_put_cstring(c->path);
1436 packet_put_int(c->host_port);
1438 /* listen address, port */
1439 packet_put_cstring(c->path);
1440 packet_put_int(c->listening_port);
1442 /* originator host and port */
1443 packet_put_cstring(remote_ipaddr);
1444 packet_put_int((u_int)remote_port);
1447 packet_start(SSH_MSG_PORT_OPEN);
1448 packet_put_int(c->self);
1449 packet_put_cstring(c->path);
1450 packet_put_int(c->host_port);
1451 if (packet_get_protocol_flags() &
1452 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1453 packet_put_cstring(c->remote_name);
1456 xfree(remote_ipaddr);
1460 channel_set_reuseaddr(int fd)
1465 * Set socket options.
1466 * Allow local port reuse in TIME_WAIT.
1468 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1469 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1473 * This socket is listening for connections to a forwarded TCP/IP port.
1477 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1480 struct sockaddr_storage addr;
1481 int newsock, nextstate;
1485 if (FD_ISSET(c->sock, readset)) {
1486 debug("Connection to port %d forwarding "
1487 "to %.100s port %d requested.",
1488 c->listening_port, c->path, c->host_port);
1490 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1491 nextstate = SSH_CHANNEL_OPENING;
1492 rtype = "forwarded-tcpip";
1494 if (c->host_port == 0) {
1495 nextstate = SSH_CHANNEL_DYNAMIC;
1496 rtype = "dynamic-tcpip";
1498 nextstate = SSH_CHANNEL_OPENING;
1499 rtype = "direct-tcpip";
1503 addrlen = sizeof(addr);
1504 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1506 error("accept: %.100s", strerror(errno));
1509 set_nodelay(newsock);
1510 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1511 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1512 nc->listening_port = c->listening_port;
1513 nc->host_port = c->host_port;
1514 if (c->path != NULL)
1515 nc->path = xstrdup(c->path);
1517 if (nextstate != SSH_CHANNEL_DYNAMIC)
1518 port_open_helper(nc, rtype);
1523 * This is the authentication agent socket listening for connections from
1528 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1532 struct sockaddr_storage addr;
1535 if (FD_ISSET(c->sock, readset)) {
1536 addrlen = sizeof(addr);
1537 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1539 error("accept from auth socket: %.100s", strerror(errno));
1542 nc = channel_new("accepted auth socket",
1543 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1544 c->local_window_max, c->local_maxpacket,
1545 0, "accepted auth socket", 1);
1547 packet_start(SSH2_MSG_CHANNEL_OPEN);
1548 packet_put_cstring("auth-agent@openssh.com");
1549 packet_put_int(nc->self);
1550 packet_put_int(c->local_window_max);
1551 packet_put_int(c->local_maxpacket);
1553 packet_start(SSH_SMSG_AGENT_OPEN);
1554 packet_put_int(nc->self);
1562 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1565 socklen_t sz = sizeof(err);
1567 if (FD_ISSET(c->sock, writeset)) {
1568 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1570 error("getsockopt SO_ERROR failed");
1573 debug("channel %d: connected to %s port %d",
1574 c->self, c->connect_ctx.host, c->connect_ctx.port);
1575 channel_connect_ctx_free(&c->connect_ctx);
1576 c->type = SSH_CHANNEL_OPEN;
1578 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1579 packet_put_int(c->remote_id);
1580 packet_put_int(c->self);
1581 packet_put_int(c->local_window);
1582 packet_put_int(c->local_maxpacket);
1584 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1585 packet_put_int(c->remote_id);
1586 packet_put_int(c->self);
1589 debug("channel %d: connection failed: %s",
1590 c->self, strerror(err));
1591 /* Try next address, if any */
1592 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1594 c->sock = c->rfd = c->wfd = sock;
1595 channel_max_fd = channel_find_maxfd();
1598 /* Exhausted all addresses */
1599 error("connect_to %.100s port %d: failed.",
1600 c->connect_ctx.host, c->connect_ctx.port);
1601 channel_connect_ctx_free(&c->connect_ctx);
1603 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1604 packet_put_int(c->remote_id);
1605 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1606 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1607 packet_put_cstring(strerror(err));
1608 packet_put_cstring("");
1611 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1612 packet_put_int(c->remote_id);
1622 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1624 char buf[CHAN_RBUF];
1627 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1628 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1630 len = read(c->rfd, buf, sizeof(buf));
1631 if (len < 0 && (errno == EINTR ||
1632 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1634 #ifndef PTY_ZEROREAD
1637 if ((!c->isatty && len <= 0) ||
1638 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1640 debug2("channel %d: read<=0 rfd %d len %d",
1641 c->self, c->rfd, len);
1642 if (c->type != SSH_CHANNEL_OPEN) {
1643 debug2("channel %d: not open", c->self);
1646 } else if (compat13) {
1647 buffer_clear(&c->output);
1648 c->type = SSH_CHANNEL_INPUT_DRAINING;
1649 debug2("channel %d: input draining.", c->self);
1651 chan_read_failed(c);
1655 if (c->input_filter != NULL) {
1656 if (c->input_filter(c, buf, len) == -1) {
1657 debug2("channel %d: filter stops", c->self);
1658 chan_read_failed(c);
1660 } else if (c->datagram) {
1661 buffer_put_string(&c->input, buf, len);
1663 buffer_append(&c->input, buf, len);
1671 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1674 u_char *data = NULL, *buf;
1675 u_int dlen, olen = 0;
1678 /* Send buffered output data to the socket. */
1680 FD_ISSET(c->wfd, writeset) &&
1681 buffer_len(&c->output) > 0) {
1682 olen = buffer_len(&c->output);
1683 if (c->output_filter != NULL) {
1684 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1685 debug2("channel %d: filter stops", c->self);
1686 if (c->type != SSH_CHANNEL_OPEN)
1689 chan_write_failed(c);
1692 } else if (c->datagram) {
1693 buf = data = buffer_get_string(&c->output, &dlen);
1695 buf = data = buffer_ptr(&c->output);
1696 dlen = buffer_len(&c->output);
1700 /* ignore truncated writes, datagrams might get lost */
1701 len = write(c->wfd, buf, dlen);
1703 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1704 errno == EWOULDBLOCK))
1707 if (c->type != SSH_CHANNEL_OPEN)
1710 chan_write_failed(c);
1716 /* XXX: Later AIX versions can't push as much data to tty */
1717 if (compat20 && c->wfd_isatty)
1718 dlen = MIN(dlen, 8*1024);
1721 len = write(c->wfd, buf, dlen);
1723 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1726 if (c->type != SSH_CHANNEL_OPEN) {
1727 debug2("channel %d: not open", c->self);
1730 } else if (compat13) {
1731 buffer_clear(&c->output);
1732 debug2("channel %d: input draining.", c->self);
1733 c->type = SSH_CHANNEL_INPUT_DRAINING;
1735 chan_write_failed(c);
1739 #ifndef BROKEN_TCGETATTR_ICANON
1740 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1741 if (tcgetattr(c->wfd, &tio) == 0 &&
1742 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1744 * Simulate echo to reduce the impact of
1745 * traffic analysis. We need to match the
1746 * size of a SSH2_MSG_CHANNEL_DATA message
1747 * (4 byte channel id + buf)
1749 packet_send_ignore(4 + len);
1754 buffer_consume(&c->output, len);
1757 if (compat20 && olen > 0)
1758 c->local_consumed += olen - buffer_len(&c->output);
1763 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1765 char buf[CHAN_RBUF];
1768 /** XXX handle drain efd, too */
1770 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1771 FD_ISSET(c->efd, writeset) &&
1772 buffer_len(&c->extended) > 0) {
1773 len = write(c->efd, buffer_ptr(&c->extended),
1774 buffer_len(&c->extended));
1775 debug2("channel %d: written %d to efd %d",
1776 c->self, len, c->efd);
1777 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1778 errno == EWOULDBLOCK))
1781 debug2("channel %d: closing write-efd %d",
1783 channel_close_fd(&c->efd);
1785 buffer_consume(&c->extended, len);
1786 c->local_consumed += len;
1788 } else if (c->efd != -1 &&
1789 (c->extended_usage == CHAN_EXTENDED_READ ||
1790 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1791 (c->detach_close || FD_ISSET(c->efd, readset))) {
1792 len = read(c->efd, buf, sizeof(buf));
1793 debug2("channel %d: read %d from efd %d",
1794 c->self, len, c->efd);
1795 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1796 errno == EWOULDBLOCK) && !c->detach_close)))
1799 debug2("channel %d: closing read-efd %d",
1801 channel_close_fd(&c->efd);
1803 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1804 debug3("channel %d: discard efd",
1807 buffer_append(&c->extended, buf, len);
1815 channel_check_window(Channel *c)
1817 if (c->type == SSH_CHANNEL_OPEN &&
1818 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1819 ((c->local_window_max - c->local_window >
1820 c->local_maxpacket*3) ||
1821 c->local_window < c->local_window_max/2) &&
1822 c->local_consumed > 0) {
1824 /* adjust max window size if we are in a dynamic environment */
1825 if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
1826 /* grow the window somewhat aggressively to maintain pressure */
1827 addition = 1.5*(c->tcpwinsz - c->local_window_max);
1828 c->local_window_max += addition;
1830 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1831 packet_put_int(c->remote_id);
1832 packet_put_int(c->local_consumed + addition);
1834 debug2("channel %d: window %d sent adjust %d",
1835 c->self, c->local_window,
1837 c->local_window += c->local_consumed + addition;
1838 c->local_consumed = 0;
1844 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1846 channel_handle_rfd(c, readset, writeset);
1847 channel_handle_wfd(c, readset, writeset);
1850 channel_handle_efd(c, readset, writeset);
1851 channel_check_window(c);
1855 read_mux(Channel *c, u_int need)
1857 char buf[CHAN_RBUF];
1861 if (buffer_len(&c->input) < need) {
1862 rlen = need - buffer_len(&c->input);
1863 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1865 if (errno != EINTR && errno != EAGAIN) {
1866 debug2("channel %d: ctl read<=0 rfd %d len %d",
1867 c->self, c->rfd, len);
1868 chan_read_failed(c);
1872 buffer_append(&c->input, buf, len);
1874 return buffer_len(&c->input);
1878 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1884 fatal("%s: entered with !compat20", __func__);
1886 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1887 (c->istate == CHAN_INPUT_OPEN ||
1888 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1890 * Don't not read past the precise end of packets to
1891 * avoid disrupting fd passing.
1893 if (read_mux(c, 4) < 4) /* read header */
1895 need = get_u32(buffer_ptr(&c->input));
1896 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1897 if (need > CHANNEL_MUX_MAX_PACKET) {
1898 debug2("channel %d: packet too big %u > %u",
1899 c->self, CHANNEL_MUX_MAX_PACKET, need);
1900 chan_rcvd_oclose(c);
1903 if (read_mux(c, need + 4) < need + 4) /* read body */
1905 if (c->mux_rcb(c) != 0) {
1906 debug("channel %d: mux_rcb failed", c->self);
1912 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1913 buffer_len(&c->output) > 0) {
1914 len = write(c->wfd, buffer_ptr(&c->output),
1915 buffer_len(&c->output));
1916 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1922 buffer_consume(&c->output, len);
1927 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1930 struct sockaddr_storage addr;
1936 if (!FD_ISSET(c->sock, readset))
1939 debug("multiplexing control connection");
1942 * Accept connection on control socket
1944 memset(&addr, 0, sizeof(addr));
1945 addrlen = sizeof(addr);
1946 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1948 error("%s accept: %s", __func__, strerror(errno));
1952 if (getpeereid(newsock, &euid, &egid) < 0) {
1953 error("%s getpeereid failed: %s", __func__,
1958 if ((euid != 0) && (getuid() != euid)) {
1959 error("multiplex uid mismatch: peer euid %u != uid %u",
1960 (u_int)euid, (u_int)getuid());
1964 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1965 newsock, newsock, -1, c->local_window_max,
1966 c->local_maxpacket, 0, "mux-control", 1);
1967 nc->mux_rcb = c->mux_rcb;
1968 debug3("%s: new mux channel %d fd %d", __func__,
1969 nc->self, nc->sock);
1970 /* establish state */
1972 /* mux state transitions must not elicit protocol messages */
1973 nc->flags |= CHAN_LOCAL;
1978 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1982 /* Send buffered output data to the socket. */
1983 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1984 len = write(c->sock, buffer_ptr(&c->output),
1985 buffer_len(&c->output));
1987 buffer_clear(&c->output);
1989 buffer_consume(&c->output, len);
1994 channel_handler_init_20(void)
1996 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1997 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1998 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1999 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2000 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2001 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2002 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2003 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2004 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2005 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2007 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2008 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2009 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2010 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2011 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2012 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2013 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2014 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2015 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2019 channel_handler_init_13(void)
2021 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2022 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2023 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2024 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2025 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2026 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2027 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2028 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2029 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2031 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2032 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2033 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2034 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2035 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2036 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2037 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2041 channel_handler_init_15(void)
2043 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2044 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2045 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2046 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2047 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2048 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2049 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2051 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2052 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2053 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2054 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2055 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2056 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2060 channel_handler_init(void)
2064 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2065 channel_pre[i] = NULL;
2066 channel_post[i] = NULL;
2069 channel_handler_init_20();
2071 channel_handler_init_13();
2073 channel_handler_init_15();
2076 /* gc dead channels */
2078 channel_garbage_collect(Channel *c)
2082 if (c->detach_user != NULL) {
2083 if (!chan_is_dead(c, c->detach_close))
2085 debug2("channel %d: gc: notify user", c->self);
2086 c->detach_user(c->self, NULL);
2087 /* if we still have a callback */
2088 if (c->detach_user != NULL)
2090 debug2("channel %d: gc: user detached", c->self);
2092 if (!chan_is_dead(c, 1))
2094 debug2("channel %d: garbage collecting", c->self);
2099 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
2101 static int did_init = 0;
2106 channel_handler_init();
2109 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2114 if (ftab == channel_pre)
2119 if (ftab[c->type] != NULL)
2120 (*ftab[c->type])(c, readset, writeset);
2121 channel_garbage_collect(c);
2126 * Allocate/update select bitmasks and add any bits relevant to channels in
2130 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2131 u_int *nallocp, int rekeying)
2133 u_int n, sz, nfdset;
2135 n = MAX(*maxfdp, channel_max_fd);
2137 nfdset = howmany(n+1, NFDBITS);
2138 /* Explicitly test here, because xrealloc isn't always called */
2139 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2140 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2141 sz = nfdset * sizeof(fd_mask);
2143 /* perhaps check sz < nalloc/2 and shrink? */
2144 if (*readsetp == NULL || sz > *nallocp) {
2145 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2146 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2150 memset(*readsetp, 0, sz);
2151 memset(*writesetp, 0, sz);
2154 channel_handler(channel_pre, *readsetp, *writesetp);
2158 * After select, perform any appropriate operations for channels which have
2162 channel_after_select(fd_set *readset, fd_set *writeset)
2164 channel_handler(channel_post, readset, writeset);
2168 /* If there is data to send to the connection, enqueue some of it now. */
2170 channel_output_poll(void)
2174 int packet_length = 0;
2176 for (i = 0; i < channels_alloc; i++) {
2182 * We are only interested in channels that can have buffered
2186 if (c->type != SSH_CHANNEL_OPEN &&
2187 c->type != SSH_CHANNEL_INPUT_DRAINING)
2190 if (c->type != SSH_CHANNEL_OPEN)
2194 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2195 /* XXX is this true? */
2196 debug3("channel %d: will not send data after close", c->self);
2200 /* Get the amount of buffered data for this channel. */
2201 if ((c->istate == CHAN_INPUT_OPEN ||
2202 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2203 (len = buffer_len(&c->input)) > 0) {
2209 data = buffer_get_string(&c->input,
2211 if (dlen > c->remote_window ||
2212 dlen > c->remote_maxpacket) {
2213 debug("channel %d: datagram "
2214 "too big for channel",
2219 packet_start(SSH2_MSG_CHANNEL_DATA);
2220 packet_put_int(c->remote_id);
2221 packet_put_string(data, dlen);
2222 packet_length = packet_send();
2223 c->remote_window -= dlen + 4;
2229 * Send some data for the other side over the secure
2233 if (len > c->remote_window)
2234 len = c->remote_window;
2235 if (len > c->remote_maxpacket)
2236 len = c->remote_maxpacket;
2238 if (packet_is_interactive()) {
2242 /* Keep the packets at reasonable size. */
2243 if (len > packet_get_maxsize()/2)
2244 len = packet_get_maxsize()/2;
2248 packet_start(compat20 ?
2249 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2250 packet_put_int(c->remote_id);
2251 packet_put_string(buffer_ptr(&c->input), len);
2252 packet_length = packet_send();
2253 buffer_consume(&c->input, len);
2254 c->remote_window -= len;
2256 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2258 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2260 * input-buffer is empty and read-socket shutdown:
2261 * tell peer, that we will not send more data: send IEOF.
2262 * hack for extended data: delay EOF if EFD still in use.
2264 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2265 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2266 c->self, c->efd, buffer_len(&c->extended));
2270 /* Send extended data, i.e. stderr */
2272 !(c->flags & CHAN_EOF_SENT) &&
2273 c->remote_window > 0 &&
2274 (len = buffer_len(&c->extended)) > 0 &&
2275 c->extended_usage == CHAN_EXTENDED_READ) {
2276 debug2("channel %d: rwin %u elen %u euse %d",
2277 c->self, c->remote_window, buffer_len(&c->extended),
2279 if (len > c->remote_window)
2280 len = c->remote_window;
2281 if (len > c->remote_maxpacket)
2282 len = c->remote_maxpacket;
2283 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2284 packet_put_int(c->remote_id);
2285 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2286 packet_put_string(buffer_ptr(&c->extended), len);
2287 packet_length = packet_send();
2288 buffer_consume(&c->extended, len);
2289 c->remote_window -= len;
2290 debug2("channel %d: sent ext data %d", c->self, len);
2293 return (packet_length);
2297 /* -- protocol input */
2301 channel_input_data(int type, u_int32_t seq, void *ctxt)
2305 u_int data_len, win_len;
2308 /* Get the channel number and verify it. */
2309 id = packet_get_int();
2310 c = channel_lookup(id);
2312 packet_disconnect("Received data for nonexistent channel %d.", id);
2314 /* Ignore any data for non-open channels (might happen on close) */
2315 if (c->type != SSH_CHANNEL_OPEN &&
2316 c->type != SSH_CHANNEL_X11_OPEN)
2320 data = packet_get_string_ptr(&data_len);
2323 win_len += 4; /* string length header */
2326 * Ignore data for protocol > 1.3 if output end is no longer open.
2327 * For protocol 2 the sending side is reducing its window as it sends
2328 * data, so we must 'fake' consumption of the data in order to ensure
2329 * that window updates are sent back. Otherwise the connection might
2332 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2334 c->local_window -= win_len;
2335 c->local_consumed += win_len;
2341 if (win_len > c->local_maxpacket) {
2342 logit("channel %d: rcvd big packet %d, maxpack %d",
2343 c->self, win_len, c->local_maxpacket);
2345 if (win_len > c->local_window) {
2346 logit("channel %d: rcvd too much data %d, win %d",
2347 c->self, win_len, c->local_window);
2350 c->local_window -= win_len;
2353 buffer_put_string(&c->output, data, data_len);
2355 buffer_append(&c->output, data, data_len);
2361 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2365 u_int data_len, tcode;
2368 /* Get the channel number and verify it. */
2369 id = packet_get_int();
2370 c = channel_lookup(id);
2373 packet_disconnect("Received extended_data for bad channel %d.", id);
2374 if (c->type != SSH_CHANNEL_OPEN) {
2375 logit("channel %d: ext data for non open", id);
2378 if (c->flags & CHAN_EOF_RCVD) {
2379 if (datafellows & SSH_BUG_EXTEOF)
2380 debug("channel %d: accepting ext data after eof", id);
2382 packet_disconnect("Received extended_data after EOF "
2383 "on channel %d.", id);
2385 tcode = packet_get_int();
2387 c->extended_usage != CHAN_EXTENDED_WRITE ||
2388 tcode != SSH2_EXTENDED_DATA_STDERR) {
2389 logit("channel %d: bad ext data", c->self);
2392 data = packet_get_string(&data_len);
2394 if (data_len > c->local_window) {
2395 logit("channel %d: rcvd too much extended_data %d, win %d",
2396 c->self, data_len, c->local_window);
2400 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2401 c->local_window -= data_len;
2402 buffer_append(&c->extended, data, data_len);
2408 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2413 id = packet_get_int();
2415 c = channel_lookup(id);
2417 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2420 /* XXX force input close */
2421 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2422 debug("channel %d: FORCE input drain", c->self);
2423 c->istate = CHAN_INPUT_WAIT_DRAIN;
2424 if (buffer_len(&c->input) == 0)
2432 channel_input_close(int type, u_int32_t seq, void *ctxt)
2437 id = packet_get_int();
2439 c = channel_lookup(id);
2441 packet_disconnect("Received close for nonexistent channel %d.", id);
2444 * Send a confirmation that we have closed the channel and no more
2445 * data is coming for it.
2447 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2448 packet_put_int(c->remote_id);
2452 * If the channel is in closed state, we have sent a close request,
2453 * and the other side will eventually respond with a confirmation.
2454 * Thus, we cannot free the channel here, because then there would be
2455 * no-one to receive the confirmation. The channel gets freed when
2456 * the confirmation arrives.
2458 if (c->type != SSH_CHANNEL_CLOSED) {
2460 * Not a closed channel - mark it as draining, which will
2461 * cause it to be freed later.
2463 buffer_clear(&c->input);
2464 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2468 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2471 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2473 int id = packet_get_int();
2474 Channel *c = channel_lookup(id);
2478 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2479 chan_rcvd_oclose(c);
2484 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2486 int id = packet_get_int();
2487 Channel *c = channel_lookup(id);
2491 packet_disconnect("Received close confirmation for "
2492 "out-of-range channel %d.", id);
2493 if (c->type != SSH_CHANNEL_CLOSED)
2494 packet_disconnect("Received close confirmation for "
2495 "non-closed channel %d (type %d).", id, c->type);
2501 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2506 id = packet_get_int();
2507 c = channel_lookup(id);
2509 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2510 packet_disconnect("Received open confirmation for "
2511 "non-opening channel %d.", id);
2512 remote_id = packet_get_int();
2513 /* Record the remote channel number and mark that the channel is now open. */
2514 c->remote_id = remote_id;
2515 c->type = SSH_CHANNEL_OPEN;
2518 c->remote_window = packet_get_int();
2519 c->remote_maxpacket = packet_get_int();
2520 if (c->open_confirm) {
2521 debug2("callback start");
2522 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2523 debug2("callback done");
2525 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2526 c->remote_window, c->remote_maxpacket);
2532 reason2txt(int reason)
2535 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2536 return "administratively prohibited";
2537 case SSH2_OPEN_CONNECT_FAILED:
2538 return "connect failed";
2539 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2540 return "unknown channel type";
2541 case SSH2_OPEN_RESOURCE_SHORTAGE:
2542 return "resource shortage";
2544 return "unknown reason";
2549 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2552 char *msg = NULL, *lang = NULL;
2555 id = packet_get_int();
2556 c = channel_lookup(id);
2558 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2559 packet_disconnect("Received open failure for "
2560 "non-opening channel %d.", id);
2562 reason = packet_get_int();
2563 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2564 msg = packet_get_string(NULL);
2565 lang = packet_get_string(NULL);
2567 logit("channel %d: open failed: %s%s%s", id,
2568 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2573 if (c->open_confirm) {
2574 debug2("callback start");
2575 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2576 debug2("callback done");
2580 /* Schedule the channel for cleanup/deletion. */
2586 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2595 /* Get the channel number and verify it. */
2596 id = packet_get_int();
2597 c = channel_lookup(id);
2600 logit("Received window adjust for non-open channel %d.", id);
2603 adjust = packet_get_int();
2605 debug2("channel %d: rcvd adjust %u", id, adjust);
2606 c->remote_window += adjust;
2611 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2615 char *host, *originator_string;
2618 remote_id = packet_get_int();
2619 host = packet_get_string(NULL);
2620 host_port = packet_get_int();
2622 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2623 originator_string = packet_get_string(NULL);
2625 originator_string = xstrdup("unknown (remote did not supply name)");
2628 c = channel_connect_to(host, host_port,
2629 "connected socket", originator_string);
2630 xfree(originator_string);
2633 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2634 packet_put_int(remote_id);
2637 c->remote_id = remote_id;
2642 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2645 struct channel_confirm *cc;
2648 /* Reset keepalive timeout */
2649 packet_set_alive_timeouts(0);
2651 id = packet_get_int();
2654 debug2("channel_input_status_confirm: type %d id %d", type, id);
2656 if ((c = channel_lookup(id)) == NULL) {
2657 logit("channel_input_status_confirm: %d: unknown", id);
2661 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2663 cc->cb(type, c, cc->ctx);
2664 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2665 bzero(cc, sizeof(*cc));
2669 /* -- tcp forwarding */
2672 channel_set_af(int af)
2679 channel_set_hpn(int external_hpn_disabled, int external_hpn_buffer_size)
2681 hpn_disabled = external_hpn_disabled;
2682 hpn_buffer_size = external_hpn_buffer_size;
2683 debug("HPN Disabled: %d, HPN Buffer Size: %d", hpn_disabled, hpn_buffer_size);
2687 channel_setup_fwd_listener(int type, const char *listen_addr,
2688 u_short listen_port, int *allocated_listen_port,
2689 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2692 int sock, r, success = 0, wildcard = 0, is_client;
2693 struct addrinfo hints, *ai, *aitop;
2694 const char *host, *addr;
2695 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2698 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2699 listen_addr : host_to_connect;
2700 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2703 error("No forward host name.");
2706 if (strlen(host) >= NI_MAXHOST) {
2707 error("Forward host name too long.");
2712 * Determine whether or not a port forward listens to loopback,
2713 * specified address or wildcard. On the client, a specified bind
2714 * address will always override gateway_ports. On the server, a
2715 * gateway_ports of 1 (``yes'') will override the client's
2716 * specification and force a wildcard bind, whereas a value of 2
2717 * (``clientspecified'') will bind to whatever address the client
2720 * Special-case listen_addrs are:
2722 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2723 * "" (empty string), "*" -> wildcard v4/v6
2724 * "localhost" -> loopback v4/v6
2727 if (listen_addr == NULL) {
2728 /* No address specified: default to gateway_ports setting */
2731 } else if (gateway_ports || is_client) {
2732 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2733 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2734 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2735 (!is_client && gateway_ports == 1))
2737 else if (strcmp(listen_addr, "localhost") != 0)
2741 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2742 type, wildcard, (addr == NULL) ? "NULL" : addr);
2745 * getaddrinfo returns a loopback address if the hostname is
2746 * set to NULL and hints.ai_flags is not AI_PASSIVE
2748 memset(&hints, 0, sizeof(hints));
2749 hints.ai_family = IPv4or6;
2750 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2751 hints.ai_socktype = SOCK_STREAM;
2752 snprintf(strport, sizeof strport, "%d", listen_port);
2753 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2755 /* This really shouldn't happen */
2756 packet_disconnect("getaddrinfo: fatal error: %s",
2757 ssh_gai_strerror(r));
2759 error("channel_setup_fwd_listener: "
2760 "getaddrinfo(%.64s): %s", addr,
2761 ssh_gai_strerror(r));
2765 if (allocated_listen_port != NULL)
2766 *allocated_listen_port = 0;
2767 for (ai = aitop; ai; ai = ai->ai_next) {
2768 switch (ai->ai_family) {
2770 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2774 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2781 * If allocating a port for -R forwards, then use the
2782 * same port for all address families.
2784 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2785 allocated_listen_port != NULL && *allocated_listen_port > 0)
2786 *lport_p = htons(*allocated_listen_port);
2788 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2789 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2790 error("channel_setup_fwd_listener: getnameinfo failed");
2793 /* Create a port to listen for the host. */
2794 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2796 /* this is no error since kernel may not support ipv6 */
2797 verbose("socket: %.100s", strerror(errno));
2801 channel_set_reuseaddr(sock);
2802 if (ai->ai_family == AF_INET6)
2803 sock_set_v6only(sock);
2805 debug("Local forwarding listening on %s port %s.",
2808 /* Bind the socket to the address. */
2809 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2810 /* address can be in use ipv6 address is already bound */
2812 error("bind: %.100s", strerror(errno));
2814 verbose("bind: %.100s", strerror(errno));
2819 /* Start listening for connections on the socket. */
2820 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2821 error("listen: %.100s", strerror(errno));
2827 * listen_port == 0 requests a dynamically allocated port -
2828 * record what we got.
2830 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2831 allocated_listen_port != NULL &&
2832 *allocated_listen_port == 0) {
2833 *allocated_listen_port = get_sock_port(sock, 1);
2834 debug("Allocated listen port %d",
2835 *allocated_listen_port);
2838 /* Allocate a channel number for the socket. */
2839 /* explicitly test for hpn disabled option. if true use smaller window size */
2841 c = channel_new("port listener", type, sock, sock, -1,
2842 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2843 0, "port listener", 1);
2845 c = channel_new("port listener", type, sock, sock, -1,
2846 hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
2847 0, "port listener", 1);
2848 c->path = xstrdup(host);
2849 c->host_port = port_to_connect;
2850 c->listening_port = listen_port;
2854 error("channel_setup_fwd_listener: cannot listen to port: %d",
2856 freeaddrinfo(aitop);
2861 channel_cancel_rport_listener(const char *host, u_short port)
2866 for (i = 0; i < channels_alloc; i++) {
2867 Channel *c = channels[i];
2869 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2870 strcmp(c->path, host) == 0 && c->listening_port == port) {
2871 debug2("%s: close channel %d", __func__, i);
2880 /* protocol local port fwd, used by ssh (and sshd in v1) */
2882 channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2883 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2885 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2886 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2890 /* protocol v2 remote port fwd, used by sshd */
2892 channel_setup_remote_fwd_listener(const char *listen_address,
2893 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2895 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2896 listen_address, listen_port, allocated_listen_port,
2897 NULL, 0, gateway_ports);
2901 * Initiate forwarding of connections to port "port" on remote host through
2902 * the secure channel to host:port from local side.
2906 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2907 const char *host_to_connect, u_short port_to_connect)
2909 int type, success = 0;
2911 /* Send the forward request to the remote side. */
2913 const char *address_to_bind;
2914 if (listen_host == NULL) {
2915 if (datafellows & SSH_BUG_RFWD_ADDR)
2916 address_to_bind = "127.0.0.1";
2918 address_to_bind = "localhost";
2919 } else if (*listen_host == '\0' ||
2920 strcmp(listen_host, "*") == 0) {
2921 if (datafellows & SSH_BUG_RFWD_ADDR)
2922 address_to_bind = "0.0.0.0";
2924 address_to_bind = "";
2926 address_to_bind = listen_host;
2928 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2929 packet_put_cstring("tcpip-forward");
2930 packet_put_char(1); /* boolean: want reply */
2931 packet_put_cstring(address_to_bind);
2932 packet_put_int(listen_port);
2934 packet_write_wait();
2935 /* Assume that server accepts the request */
2938 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2939 packet_put_int(listen_port);
2940 packet_put_cstring(host_to_connect);
2941 packet_put_int(port_to_connect);
2943 packet_write_wait();
2945 /* Wait for response from the remote side. */
2946 type = packet_read();
2948 case SSH_SMSG_SUCCESS:
2951 case SSH_SMSG_FAILURE:
2954 /* Unknown packet */
2955 packet_disconnect("Protocol error for port forward request:"
2956 "received packet type %d.", type);
2960 /* Record that connection to this host/port is permitted. */
2961 permitted_opens = xrealloc(permitted_opens,
2962 num_permitted_opens + 1, sizeof(*permitted_opens));
2963 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2964 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2965 permitted_opens[num_permitted_opens].listen_port = listen_port;
2966 num_permitted_opens++;
2968 return (success ? 0 : -1);
2972 * Request cancellation of remote forwarding of connection host:port from
2976 channel_request_rforward_cancel(const char *host, u_short port)
2983 for (i = 0; i < num_permitted_opens; i++) {
2984 if (permitted_opens[i].host_to_connect != NULL &&
2985 permitted_opens[i].listen_port == port)
2988 if (i >= num_permitted_opens) {
2989 debug("%s: requested forward not found", __func__);
2992 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2993 packet_put_cstring("cancel-tcpip-forward");
2995 packet_put_cstring(host == NULL ? "" : host);
2996 packet_put_int(port);
2999 permitted_opens[i].listen_port = 0;
3000 permitted_opens[i].port_to_connect = 0;
3001 xfree(permitted_opens[i].host_to_connect);
3002 permitted_opens[i].host_to_connect = NULL;
3006 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3007 * listening for the port, and sends back a success reply (or disconnect
3008 * message if there was an error).
3011 channel_input_port_forward_request(int is_root, int gateway_ports)
3013 u_short port, host_port;
3017 /* Get arguments from the packet. */
3018 port = packet_get_int();
3019 hostname = packet_get_string(NULL);
3020 host_port = packet_get_int();
3024 * Check that an unprivileged user is not trying to forward a
3027 if (port < IPPORT_RESERVED && !is_root)
3029 "Requested forwarding of port %d but user is not root.",
3032 packet_disconnect("Dynamic forwarding denied.");
3035 /* Initiate forwarding */
3036 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3037 host_port, gateway_ports);
3039 /* Free the argument string. */
3042 return (success ? 0 : -1);
3046 * Permits opening to any host/port if permitted_opens[] is empty. This is
3047 * usually called by the server, because the user could connect to any port
3048 * anyway, and the server has no way to know but to trust the client anyway.
3051 channel_permit_all_opens(void)
3053 if (num_permitted_opens == 0)
3054 all_opens_permitted = 1;
3058 channel_add_permitted_opens(char *host, int port)
3060 debug("allow port forwarding to host %s port %d", host, port);
3062 permitted_opens = xrealloc(permitted_opens,
3063 num_permitted_opens + 1, sizeof(*permitted_opens));
3064 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3065 permitted_opens[num_permitted_opens].port_to_connect = port;
3066 num_permitted_opens++;
3068 all_opens_permitted = 0;
3072 channel_add_adm_permitted_opens(char *host, int port)
3074 debug("config allows port forwarding to host %s port %d", host, port);
3076 permitted_adm_opens = xrealloc(permitted_adm_opens,
3077 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3078 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3080 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3081 return ++num_adm_permitted_opens;
3085 channel_clear_permitted_opens(void)
3089 for (i = 0; i < num_permitted_opens; i++)
3090 if (permitted_opens[i].host_to_connect != NULL)
3091 xfree(permitted_opens[i].host_to_connect);
3092 if (num_permitted_opens > 0) {
3093 xfree(permitted_opens);
3094 permitted_opens = NULL;
3096 num_permitted_opens = 0;
3100 channel_clear_adm_permitted_opens(void)
3104 for (i = 0; i < num_adm_permitted_opens; i++)
3105 if (permitted_adm_opens[i].host_to_connect != NULL)
3106 xfree(permitted_adm_opens[i].host_to_connect);
3107 if (num_adm_permitted_opens > 0) {
3108 xfree(permitted_adm_opens);
3109 permitted_adm_opens = NULL;
3111 num_adm_permitted_opens = 0;
3115 channel_print_adm_permitted_opens(void)
3119 printf("permitopen");
3120 if (num_adm_permitted_opens == 0) {
3124 for (i = 0; i < num_adm_permitted_opens; i++)
3125 if (permitted_adm_opens[i].host_to_connect != NULL)
3126 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3127 permitted_adm_opens[i].port_to_connect);
3131 /* Try to start non-blocking connect to next host in cctx list */
3133 connect_next(struct channel_connect *cctx)
3135 int sock, saved_errno;
3136 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3138 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3139 if (cctx->ai->ai_family != AF_INET &&
3140 cctx->ai->ai_family != AF_INET6)
3142 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3143 ntop, sizeof(ntop), strport, sizeof(strport),
3144 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3145 error("connect_next: getnameinfo failed");
3148 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3149 cctx->ai->ai_protocol)) == -1) {
3150 if (cctx->ai->ai_next == NULL)
3151 error("socket: %.100s", strerror(errno));
3153 verbose("socket: %.100s", strerror(errno));
3156 if (set_nonblock(sock) == -1)
3157 fatal("%s: set_nonblock(%d)", __func__, sock);
3158 if (connect(sock, cctx->ai->ai_addr,
3159 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3160 debug("connect_next: host %.100s ([%.100s]:%s): "
3161 "%.100s", cctx->host, ntop, strport,
3163 saved_errno = errno;
3165 errno = saved_errno;
3166 continue; /* fail -- try next */
3168 debug("connect_next: host %.100s ([%.100s]:%s) "
3169 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3170 cctx->ai = cctx->ai->ai_next;
3178 channel_connect_ctx_free(struct channel_connect *cctx)
3182 freeaddrinfo(cctx->aitop);
3183 bzero(cctx, sizeof(*cctx));
3185 cctx->ai = cctx->aitop = NULL;
3188 /* Return CONNECTING channel to remote host, port */
3190 connect_to(const char *host, u_short port, char *ctype, char *rname)
3192 struct addrinfo hints;
3195 char strport[NI_MAXSERV];
3196 struct channel_connect cctx;
3199 memset(&cctx, 0, sizeof(cctx));
3200 memset(&hints, 0, sizeof(hints));
3201 hints.ai_family = IPv4or6;
3202 hints.ai_socktype = SOCK_STREAM;
3203 snprintf(strport, sizeof strport, "%d", port);
3204 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3205 error("connect_to %.100s: unknown host (%s)", host,
3206 ssh_gai_strerror(gaierr));
3210 cctx.host = xstrdup(host);
3212 cctx.ai = cctx.aitop;
3214 if ((sock = connect_next(&cctx)) == -1) {
3215 error("connect to %.100s port %d failed: %s",
3216 host, port, strerror(errno));
3217 channel_connect_ctx_free(&cctx);
3220 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3221 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3222 c->connect_ctx = cctx;
3227 channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3231 for (i = 0; i < num_permitted_opens; i++) {
3232 if (permitted_opens[i].host_to_connect != NULL &&
3233 permitted_opens[i].listen_port == listen_port) {
3235 permitted_opens[i].host_to_connect,
3236 permitted_opens[i].port_to_connect, ctype, rname);
3239 error("WARNING: Server requests forwarding for unknown listen_port %d",
3244 /* Check if connecting to that port is permitted and connect. */
3246 channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3248 int i, permit, permit_adm = 1;
3250 permit = all_opens_permitted;
3252 for (i = 0; i < num_permitted_opens; i++)
3253 if (permitted_opens[i].host_to_connect != NULL &&
3254 permitted_opens[i].port_to_connect == port &&
3255 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3259 if (num_adm_permitted_opens > 0) {
3261 for (i = 0; i < num_adm_permitted_opens; i++)
3262 if (permitted_adm_opens[i].host_to_connect != NULL &&
3263 permitted_adm_opens[i].port_to_connect == port &&
3264 strcmp(permitted_adm_opens[i].host_to_connect, host)
3269 if (!permit || !permit_adm) {
3270 logit("Received request to connect to host %.100s port %d, "
3271 "but the request was denied.", host, port);
3274 return connect_to(host, port, ctype, rname);
3278 channel_send_window_changes(void)
3283 for (i = 0; i < channels_alloc; i++) {
3284 if (channels[i] == NULL || !channels[i]->client_tty ||
3285 channels[i]->type != SSH_CHANNEL_OPEN)
3287 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3289 channel_request_start(i, "window-change", 0);
3290 packet_put_int((u_int)ws.ws_col);
3291 packet_put_int((u_int)ws.ws_row);
3292 packet_put_int((u_int)ws.ws_xpixel);
3293 packet_put_int((u_int)ws.ws_ypixel);
3298 /* -- X11 forwarding */
3301 * Creates an internet domain socket for listening for X11 connections.
3302 * Returns 0 and a suitable display number for the DISPLAY variable
3303 * stored in display_numberp , or -1 if an error occurs.
3306 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3307 int single_connection, u_int *display_numberp, int **chanids)
3310 int display_number, sock;
3312 struct addrinfo hints, *ai, *aitop;
3313 char strport[NI_MAXSERV];
3314 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3316 if (chanids == NULL)
3319 for (display_number = x11_display_offset;
3320 display_number < MAX_DISPLAYS;
3322 port = 6000 + display_number;
3323 memset(&hints, 0, sizeof(hints));
3324 hints.ai_family = IPv4or6;
3325 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3326 hints.ai_socktype = SOCK_STREAM;
3327 snprintf(strport, sizeof strport, "%d", port);
3328 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3329 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3332 for (ai = aitop; ai; ai = ai->ai_next) {
3333 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3335 sock = socket(ai->ai_family, ai->ai_socktype,
3338 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3340 && (errno != EPFNOSUPPORT)
3343 error("socket: %.100s", strerror(errno));
3344 freeaddrinfo(aitop);
3347 debug("x11_create_display_inet: Socket family %d not supported",
3352 if (ai->ai_family == AF_INET6)
3353 sock_set_v6only(sock);
3354 if (x11_use_localhost)
3355 channel_set_reuseaddr(sock);
3356 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3357 debug2("bind port %d: %.100s", port, strerror(errno));
3360 for (n = 0; n < num_socks; n++) {
3366 socks[num_socks++] = sock;
3367 if (num_socks == NUM_SOCKS)
3370 freeaddrinfo(aitop);
3374 if (display_number >= MAX_DISPLAYS) {
3375 error("Failed to allocate internet-domain X11 display socket.");
3378 /* Start listening for connections on the socket. */
3379 for (n = 0; n < num_socks; n++) {
3381 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3382 error("listen: %.100s", strerror(errno));
3388 /* Allocate a channel for each socket. */
3389 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3390 for (n = 0; n < num_socks; n++) {
3392 /* Is this really necassary? */
3394 nc = channel_new("x11 listener",
3395 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3396 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3397 0, "X11 inet listener", 1);
3399 nc = channel_new("x11 listener",
3400 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3401 hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
3402 0, "X11 inet listener", 1);
3403 nc->single_connection = single_connection;
3404 (*chanids)[n] = nc->self;
3408 /* Return the display number for the DISPLAY environment variable. */
3409 *display_numberp = display_number;
3414 connect_local_xsocket_path(const char *pathname)
3417 struct sockaddr_un addr;
3419 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3421 error("socket: %.100s", strerror(errno));
3422 memset(&addr, 0, sizeof(addr));
3423 addr.sun_family = AF_UNIX;
3424 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3425 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3428 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3433 connect_local_xsocket(u_int dnr)
3436 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3437 return connect_local_xsocket_path(buf);
3441 x11_connect_display(void)
3443 u_int display_number;
3444 const char *display;
3445 char buf[1024], *cp;
3446 struct addrinfo hints, *ai, *aitop;
3447 char strport[NI_MAXSERV];
3448 int gaierr, sock = 0;
3450 /* Try to open a socket for the local X server. */
3451 display = getenv("DISPLAY");
3453 error("DISPLAY not set.");
3457 * Now we decode the value of the DISPLAY variable and make a
3458 * connection to the real X server.
3461 /* Check if the display is from launchd. */
3463 if (strncmp(display, "/tmp/launch", 11) == 0) {
3464 sock = connect_local_xsocket_path(display);
3468 /* OK, we now have a connection to the display. */
3473 * Check if it is a unix domain socket. Unix domain displays are in
3474 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3476 if (strncmp(display, "unix:", 5) == 0 ||
3477 display[0] == ':') {
3478 /* Connect to the unix domain socket. */
3479 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3480 error("Could not parse display number from DISPLAY: %.100s",
3484 /* Create a socket. */
3485 sock = connect_local_xsocket(display_number);
3489 /* OK, we now have a connection to the display. */
3493 * Connect to an inet socket. The DISPLAY value is supposedly
3494 * hostname:d[.s], where hostname may also be numeric IP address.
3496 strlcpy(buf, display, sizeof(buf));
3497 cp = strchr(buf, ':');
3499 error("Could not find ':' in DISPLAY: %.100s", display);
3503 /* buf now contains the host name. But first we parse the display number. */
3504 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3505 error("Could not parse display number from DISPLAY: %.100s",
3510 /* Look up the host address */
3511 memset(&hints, 0, sizeof(hints));
3512 hints.ai_family = IPv4or6;
3513 hints.ai_socktype = SOCK_STREAM;
3514 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3515 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3516 error("%.100s: unknown host. (%s)", buf,
3517 ssh_gai_strerror(gaierr));
3520 for (ai = aitop; ai; ai = ai->ai_next) {
3521 /* Create a socket. */
3522 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3524 debug2("socket: %.100s", strerror(errno));
3527 /* Connect it to the display. */
3528 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3529 debug2("connect %.100s port %u: %.100s", buf,
3530 6000 + display_number, strerror(errno));
3537 freeaddrinfo(aitop);
3539 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3548 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3549 * the remote channel number. We should do whatever we want, and respond
3550 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3555 x11_input_open(int type, u_int32_t seq, void *ctxt)
3558 int remote_id, sock = 0;
3561 debug("Received X11 open request.");
3563 remote_id = packet_get_int();
3565 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3566 remote_host = packet_get_string(NULL);
3568 remote_host = xstrdup("unknown (remote did not supply name)");
3572 /* Obtain a connection to the real X display. */
3573 sock = x11_connect_display();
3575 /* Allocate a channel for this connection. */
3576 c = channel_new("connected x11 socket",
3577 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3579 c->remote_id = remote_id;
3584 /* Send refusal to the remote host. */
3585 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3586 packet_put_int(remote_id);
3588 /* Send a confirmation to the remote host. */
3589 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3590 packet_put_int(remote_id);
3591 packet_put_int(c->self);
3596 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3599 deny_input_open(int type, u_int32_t seq, void *ctxt)
3601 int rchan = packet_get_int();
3604 case SSH_SMSG_AGENT_OPEN:
3605 error("Warning: ssh server tried agent forwarding.");
3607 case SSH_SMSG_X11_OPEN:
3608 error("Warning: ssh server tried X11 forwarding.");
3611 error("deny_input_open: type %d", type);
3614 error("Warning: this is probably a break-in attempt by a malicious server.");
3615 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3616 packet_put_int(rchan);
3621 * Requests forwarding of X11 connections, generates fake authentication
3622 * data, and enables authentication spoofing.
3623 * This should be called in the client only.
3626 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3627 const char *proto, const char *data)
3629 u_int data_len = (u_int) strlen(data) / 2;
3636 if (x11_saved_display == NULL)
3637 x11_saved_display = xstrdup(disp);
3638 else if (strcmp(disp, x11_saved_display) != 0) {
3639 error("x11_request_forwarding_with_spoofing: different "
3640 "$DISPLAY already forwarded");
3644 cp = strchr(disp, ':');
3646 cp = strchr(cp, '.');
3648 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3652 if (x11_saved_proto == NULL) {
3653 /* Save protocol name. */
3654 x11_saved_proto = xstrdup(proto);
3656 * Extract real authentication data and generate fake data
3657 * of the same length.
3659 x11_saved_data = xmalloc(data_len);
3660 x11_fake_data = xmalloc(data_len);
3661 for (i = 0; i < data_len; i++) {
3662 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3663 fatal("x11_request_forwarding: bad "
3664 "authentication data: %.100s", data);
3667 x11_saved_data[i] = value;
3668 x11_fake_data[i] = rnd & 0xff;
3671 x11_saved_data_len = data_len;
3672 x11_fake_data_len = data_len;
3675 /* Convert the fake data into hex. */
3676 new_data = tohex(x11_fake_data, data_len);
3678 /* Send the request packet. */
3680 channel_request_start(client_session_id, "x11-req", 0);
3681 packet_put_char(0); /* XXX bool single connection */
3683 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3685 packet_put_cstring(proto);
3686 packet_put_cstring(new_data);
3687 packet_put_int(screen_number);
3689 packet_write_wait();
3694 /* -- agent forwarding */
3696 /* Sends a message to the server to request authentication fd forwarding. */
3699 auth_request_forwarding(void)
3701 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3703 packet_write_wait();