1 /* $OpenBSD: channels.c,v 1.303 2010/01/30 21:12:08 djm Exp $ */
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7 * This file contains functions for generic socket connection forwarding.
8 * There is also code for initiating connection forwarding for X11 connections,
9 * arbitrary tcp/ip connections, and the authentication agent connection.
11 * As far as I am concerned, the code I have written for this software
12 * can be used freely for any purpose. Any derived versions of this
13 * software must be clearly marked as such, and if the derived work is
14 * incompatible with the protocol description in the RFC file, it must be
15 * called by a name other than "ssh" or "Secure Shell".
17 * SSH2 support added by Markus Friedl.
18 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
19 * Copyright (c) 1999 Dug Song. All rights reserved.
20 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 #include <sys/types.h>
46 #include <sys/ioctl.h>
48 #include <sys/socket.h>
49 #ifdef HAVE_SYS_TIME_H
50 # include <sys/time.h>
53 #include <netinet/in.h>
54 #include <arpa/inet.h>
66 #include "openbsd-compat/sys-queue.h"
80 #include "pathnames.h"
85 * Pointer to an array containing all allocated channels. The array is
86 * dynamically extended as needed.
88 static Channel **channels = NULL;
91 * Size of the channel array. All slots of the array must always be
92 * initialized (at least the type field); unused slots set to NULL
94 static u_int channels_alloc = 0;
97 * Maximum file descriptor value used in any of the channels. This is
98 * updated in channel_new.
100 static int channel_max_fd = 0;
103 /* -- tcp forwarding */
106 * Data structure for storing which hosts are permitted for forward requests.
107 * The local sides of any remote forwards are stored in this array to prevent
108 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
109 * network (which might be behind a firewall).
112 char *host_to_connect; /* Connect to 'host'. */
113 u_short port_to_connect; /* Connect to 'port'. */
114 u_short listen_port; /* Remote side should listen port number. */
117 /* List of all permitted host/port pairs to connect by the user. */
118 static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
120 /* List of all permitted host/port pairs to connect by the admin. */
121 static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
123 /* Number of permitted host/port pairs in the array permitted by the user. */
124 static int num_permitted_opens = 0;
126 /* Number of permitted host/port pair in the array permitted by the admin. */
127 static int num_adm_permitted_opens = 0;
130 * If this is true, all opens are permitted. This is the case on the server
131 * on which we have to trust the client anyway, and the user could do
132 * anything after logging in anyway.
134 static int all_opens_permitted = 0;
137 /* -- X11 forwarding */
139 /* Maximum number of fake X11 displays to try. */
140 #define MAX_DISPLAYS 1000
142 /* Saved X11 local (client) display. */
143 static char *x11_saved_display = NULL;
145 /* Saved X11 authentication protocol name. */
146 static char *x11_saved_proto = NULL;
148 /* Saved X11 authentication data. This is the real data. */
149 static char *x11_saved_data = NULL;
150 static u_int x11_saved_data_len = 0;
153 * Fake X11 authentication data. This is what the server will be sending us;
154 * we should replace any occurrences of this by the real data.
156 static u_char *x11_fake_data = NULL;
157 static u_int x11_fake_data_len;
160 /* -- agent forwarding */
164 /* AF_UNSPEC or AF_INET or AF_INET6 */
165 static int IPv4or6 = AF_UNSPEC;
168 static void port_open_helper(Channel *c, char *rtype);
170 /* non-blocking connect helpers */
171 static int connect_next(struct channel_connect *);
172 static void channel_connect_ctx_free(struct channel_connect *);
176 static int hpn_disabled = 0;
177 static u_int buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
179 /* -- 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->dynamic_window = 0;
319 c->local_window = window;
320 c->local_window_max = window;
321 c->local_consumed = 0;
322 c->local_maxpacket = maxpack;
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;
340 c->delayed = 1; /* prevent call to channel_post handler */
341 TAILQ_INIT(&c->status_confirms);
342 debug("channel %d: new [%s]", found, remote_name);
347 channel_find_maxfd(void)
353 for (i = 0; i < channels_alloc; i++) {
356 max = MAX(max, c->rfd);
357 max = MAX(max, c->wfd);
358 max = MAX(max, c->efd);
365 channel_close_fd(int *fdp)
367 int ret = 0, fd = *fdp;
372 if (fd == channel_max_fd)
373 channel_max_fd = channel_find_maxfd();
378 /* Close all channel fd/socket. */
380 channel_close_fds(Channel *c)
382 debug3("channel %d: close_fds r %d w %d e %d",
383 c->self, c->rfd, c->wfd, c->efd);
385 channel_close_fd(&c->sock);
386 channel_close_fd(&c->rfd);
387 channel_close_fd(&c->wfd);
388 channel_close_fd(&c->efd);
391 /* Free the channel and close its fd/socket. */
393 channel_free(Channel *c)
397 struct channel_confirm *cc;
399 for (n = 0, i = 0; i < channels_alloc; i++)
402 debug("channel %d: free: %s, nchannels %u", c->self,
403 c->remote_name ? c->remote_name : "???", n);
405 s = channel_open_message();
406 debug3("channel %d: status: %s", c->self, s);
410 shutdown(c->sock, SHUT_RDWR);
411 channel_close_fds(c);
412 buffer_free(&c->input);
413 buffer_free(&c->output);
414 buffer_free(&c->extended);
415 if (c->remote_name) {
416 xfree(c->remote_name);
417 c->remote_name = NULL;
423 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
424 if (cc->abandon_cb != NULL)
425 cc->abandon_cb(c, cc->ctx);
426 TAILQ_REMOVE(&c->status_confirms, cc, entry);
427 bzero(cc, sizeof(*cc));
430 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
431 c->filter_cleanup(c->self, c->filter_ctx);
432 channels[c->self] = NULL;
437 channel_free_all(void)
441 for (i = 0; i < channels_alloc; i++)
442 if (channels[i] != NULL)
443 channel_free(channels[i]);
447 * Closes the sockets/fds of all channels. This is used to close extra file
448 * descriptors after a fork.
451 channel_close_all(void)
455 for (i = 0; i < channels_alloc; i++)
456 if (channels[i] != NULL)
457 channel_close_fds(channels[i]);
461 * Stop listening to channels.
464 channel_stop_listening(void)
469 for (i = 0; i < channels_alloc; i++) {
473 case SSH_CHANNEL_AUTH_SOCKET:
474 case SSH_CHANNEL_PORT_LISTENER:
475 case SSH_CHANNEL_RPORT_LISTENER:
476 case SSH_CHANNEL_X11_LISTENER:
477 channel_close_fd(&c->sock);
486 * Returns true if no channel has too much buffered data, and false if one or
487 * more channel is overfull.
490 channel_not_very_much_buffered_data(void)
495 for (i = 0; i < channels_alloc; i++) {
497 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
500 buffer_len(&c->input) > packet_get_maxsize()) {
501 debug2("channel %d: big input buffer %d",
502 c->self, buffer_len(&c->input));
506 if (buffer_len(&c->output) > packet_get_maxsize()) {
507 debug2("channel %d: big output buffer %u > %u",
508 c->self, buffer_len(&c->output),
509 packet_get_maxsize());
517 /* Returns true if any channel is still open. */
519 channel_still_open(void)
524 for (i = 0; i < channels_alloc; i++) {
529 case SSH_CHANNEL_X11_LISTENER:
530 case SSH_CHANNEL_PORT_LISTENER:
531 case SSH_CHANNEL_RPORT_LISTENER:
532 case SSH_CHANNEL_MUX_LISTENER:
533 case SSH_CHANNEL_CLOSED:
534 case SSH_CHANNEL_AUTH_SOCKET:
535 case SSH_CHANNEL_DYNAMIC:
536 case SSH_CHANNEL_CONNECTING:
537 case SSH_CHANNEL_ZOMBIE:
539 case SSH_CHANNEL_LARVAL:
541 fatal("cannot happen: SSH_CHANNEL_LARVAL");
543 case SSH_CHANNEL_OPENING:
544 case SSH_CHANNEL_OPEN:
545 case SSH_CHANNEL_X11_OPEN:
546 case SSH_CHANNEL_MUX_CLIENT:
548 case SSH_CHANNEL_INPUT_DRAINING:
549 case SSH_CHANNEL_OUTPUT_DRAINING:
551 fatal("cannot happen: OUT_DRAIN");
554 fatal("channel_still_open: bad channel type %d", c->type);
561 /* Returns the id of an open channel suitable for keepaliving */
563 channel_find_open(void)
568 for (i = 0; i < channels_alloc; i++) {
570 if (c == NULL || c->remote_id < 0)
573 case SSH_CHANNEL_CLOSED:
574 case SSH_CHANNEL_DYNAMIC:
575 case SSH_CHANNEL_X11_LISTENER:
576 case SSH_CHANNEL_PORT_LISTENER:
577 case SSH_CHANNEL_RPORT_LISTENER:
578 case SSH_CHANNEL_MUX_LISTENER:
579 case SSH_CHANNEL_MUX_CLIENT:
580 case SSH_CHANNEL_OPENING:
581 case SSH_CHANNEL_CONNECTING:
582 case SSH_CHANNEL_ZOMBIE:
584 case SSH_CHANNEL_LARVAL:
585 case SSH_CHANNEL_AUTH_SOCKET:
586 case SSH_CHANNEL_OPEN:
587 case SSH_CHANNEL_X11_OPEN:
589 case SSH_CHANNEL_INPUT_DRAINING:
590 case SSH_CHANNEL_OUTPUT_DRAINING:
592 fatal("cannot happen: OUT_DRAIN");
595 fatal("channel_find_open: bad channel type %d", c->type);
604 * Returns a message describing the currently open forwarded connections,
605 * suitable for sending to the client. The message contains crlf pairs for
609 channel_open_message(void)
616 buffer_init(&buffer);
617 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
618 buffer_append(&buffer, buf, strlen(buf));
619 for (i = 0; i < channels_alloc; i++) {
624 case SSH_CHANNEL_X11_LISTENER:
625 case SSH_CHANNEL_PORT_LISTENER:
626 case SSH_CHANNEL_RPORT_LISTENER:
627 case SSH_CHANNEL_CLOSED:
628 case SSH_CHANNEL_AUTH_SOCKET:
629 case SSH_CHANNEL_ZOMBIE:
630 case SSH_CHANNEL_MUX_CLIENT:
631 case SSH_CHANNEL_MUX_LISTENER:
633 case SSH_CHANNEL_LARVAL:
634 case SSH_CHANNEL_OPENING:
635 case SSH_CHANNEL_CONNECTING:
636 case SSH_CHANNEL_DYNAMIC:
637 case SSH_CHANNEL_OPEN:
638 case SSH_CHANNEL_X11_OPEN:
639 case SSH_CHANNEL_INPUT_DRAINING:
640 case SSH_CHANNEL_OUTPUT_DRAINING:
641 snprintf(buf, sizeof buf,
642 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
643 c->self, c->remote_name,
644 c->type, c->remote_id,
645 c->istate, buffer_len(&c->input),
646 c->ostate, buffer_len(&c->output),
647 c->rfd, c->wfd, c->ctl_chan);
648 buffer_append(&buffer, buf, strlen(buf));
651 fatal("channel_open_message: bad channel type %d", c->type);
655 buffer_append(&buffer, "\0", 1);
656 cp = xstrdup(buffer_ptr(&buffer));
657 buffer_free(&buffer);
662 channel_send_open(int id)
664 Channel *c = channel_lookup(id);
667 logit("channel_send_open: %d: bad id", id);
670 debug2("channel %d: send open", id);
671 packet_start(SSH2_MSG_CHANNEL_OPEN);
672 packet_put_cstring(c->ctype);
673 packet_put_int(c->self);
674 packet_put_int(c->local_window);
675 packet_put_int(c->local_maxpacket);
680 channel_request_start(int id, char *service, int wantconfirm)
682 Channel *c = channel_lookup(id);
685 logit("channel_request_start: %d: unknown channel id", id);
688 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
689 packet_start(SSH2_MSG_CHANNEL_REQUEST);
690 packet_put_int(c->remote_id);
691 packet_put_cstring(service);
692 packet_put_char(wantconfirm);
696 channel_register_status_confirm(int id, channel_confirm_cb *cb,
697 channel_confirm_abandon_cb *abandon_cb, void *ctx)
699 struct channel_confirm *cc;
702 if ((c = channel_lookup(id)) == NULL)
703 fatal("channel_register_expect: %d: bad id", id);
705 cc = xmalloc(sizeof(*cc));
707 cc->abandon_cb = abandon_cb;
709 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
713 channel_register_open_confirm(int id, channel_callback_fn *fn, void *ctx)
715 Channel *c = channel_lookup(id);
718 logit("channel_register_open_confirm: %d: bad id", id);
721 c->open_confirm = fn;
722 c->open_confirm_ctx = ctx;
726 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
728 Channel *c = channel_by_id(id);
731 logit("channel_register_cleanup: %d: bad id", id);
735 c->detach_close = do_close;
739 channel_cancel_cleanup(int id)
741 Channel *c = channel_by_id(id);
744 logit("channel_cancel_cleanup: %d: bad id", id);
747 c->detach_user = NULL;
752 channel_register_filter(int id, channel_infilter_fn *ifn,
753 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
755 Channel *c = channel_lookup(id);
758 logit("channel_register_filter: %d: bad id", id);
761 c->input_filter = ifn;
762 c->output_filter = ofn;
764 c->filter_cleanup = cfn;
768 channel_set_fds(int id, int rfd, int wfd, int efd,
769 int extusage, int nonblock, int is_tty, u_int window_max)
771 Channel *c = channel_lookup(id);
773 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
774 fatal("channel_activate for non-larval channel %d.", id);
775 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
776 c->type = SSH_CHANNEL_OPEN;
777 c->local_window = c->local_window_max = window_max;
778 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
779 packet_put_int(c->remote_id);
780 packet_put_int(c->local_window);
785 * 'channel_pre*' are called just before select() to add any bits relevant to
786 * channels in the select bitmasks.
789 * 'channel_post*': perform any appropriate operations for channels which
790 * have events pending.
792 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
793 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
794 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
798 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
800 FD_SET(c->sock, readset);
805 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
807 debug3("channel %d: waiting for connection", c->self);
808 FD_SET(c->sock, writeset);
812 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
814 if (buffer_len(&c->input) < packet_get_maxsize())
815 FD_SET(c->sock, readset);
816 if (buffer_len(&c->output) > 0)
817 FD_SET(c->sock, writeset);
821 channel_tcpwinsz(void)
828 /* If we are not on a socket return 128KB. */
829 if (!packet_connection_is_on_socket())
833 optsz = sizeof(tcpwinsz);
834 sd = packet_get_connection_in();
835 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
837 /* Return no more than the maximum buffer size. */
838 maxlen = buffer_get_max_len();
839 if ((ret == 0) && tcpwinsz > maxlen)
841 /* In case getsockopt() failed return a minimum. */
843 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
844 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
849 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
853 /* Check buffer limits. */
854 if (!c->tcpwinsz || c->dynamic_window > 0)
855 c->tcpwinsz = channel_tcpwinsz();
857 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
860 if (c->istate == CHAN_INPUT_OPEN &&
862 buffer_len(&c->input) < limit &&
863 buffer_check_alloc(&c->input, CHAN_RBUF))
864 FD_SET(c->rfd, readset);
865 if (c->ostate == CHAN_OUTPUT_OPEN ||
866 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
867 if (buffer_len(&c->output) > 0) {
868 FD_SET(c->wfd, writeset);
869 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
870 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
871 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
872 c->self, c->efd, buffer_len(&c->extended));
877 /** XXX check close conditions, too */
878 if (compat20 && c->efd != -1 &&
879 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
880 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
881 buffer_len(&c->extended) > 0)
882 FD_SET(c->efd, writeset);
883 else if (!(c->flags & CHAN_EOF_SENT) &&
884 c->extended_usage == CHAN_EXTENDED_READ &&
885 buffer_len(&c->extended) < c->remote_window)
886 FD_SET(c->efd, readset);
888 /* XXX: What about efd? races? */
893 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
895 if (buffer_len(&c->input) == 0) {
896 packet_start(SSH_MSG_CHANNEL_CLOSE);
897 packet_put_int(c->remote_id);
899 c->type = SSH_CHANNEL_CLOSED;
900 debug2("channel %d: closing after input drain.", c->self);
906 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
908 if (buffer_len(&c->output) == 0)
911 FD_SET(c->sock, writeset);
915 * This is a special state for X11 authentication spoofing. An opened X11
916 * connection (when authentication spoofing is being done) remains in this
917 * state until the first packet has been completely read. The authentication
918 * data in that packet is then substituted by the real data if it matches the
919 * fake data, and the channel is put into normal mode.
920 * XXX All this happens at the client side.
921 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
924 x11_open_helper(Buffer *b)
927 u_int proto_len, data_len;
929 /* Check if the fixed size part of the packet is in buffer. */
930 if (buffer_len(b) < 12)
933 /* Parse the lengths of variable-length fields. */
935 if (ucp[0] == 0x42) { /* Byte order MSB first. */
936 proto_len = 256 * ucp[6] + ucp[7];
937 data_len = 256 * ucp[8] + ucp[9];
938 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
939 proto_len = ucp[6] + 256 * ucp[7];
940 data_len = ucp[8] + 256 * ucp[9];
942 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
947 /* Check if the whole packet is in buffer. */
949 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
952 /* Check if authentication protocol matches. */
953 if (proto_len != strlen(x11_saved_proto) ||
954 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
955 debug2("X11 connection uses different authentication protocol.");
958 /* Check if authentication data matches our fake data. */
959 if (data_len != x11_fake_data_len ||
960 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
961 x11_fake_data, x11_fake_data_len) != 0) {
962 debug2("X11 auth data does not match fake data.");
965 /* Check fake data length */
966 if (x11_fake_data_len != x11_saved_data_len) {
967 error("X11 fake_data_len %d != saved_data_len %d",
968 x11_fake_data_len, x11_saved_data_len);
972 * Received authentication protocol and data match
973 * our fake data. Substitute the fake data with real
976 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
977 x11_saved_data, x11_saved_data_len);
982 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
984 int ret = x11_open_helper(&c->output);
987 /* Start normal processing for the channel. */
988 c->type = SSH_CHANNEL_OPEN;
989 channel_pre_open_13(c, readset, writeset);
990 } else if (ret == -1) {
992 * We have received an X11 connection that has bad
993 * authentication information.
995 logit("X11 connection rejected because of wrong authentication.");
996 buffer_clear(&c->input);
997 buffer_clear(&c->output);
998 channel_close_fd(&c->sock);
1000 c->type = SSH_CHANNEL_CLOSED;
1001 packet_start(SSH_MSG_CHANNEL_CLOSE);
1002 packet_put_int(c->remote_id);
1008 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1010 int ret = x11_open_helper(&c->output);
1012 /* c->force_drain = 1; */
1015 c->type = SSH_CHANNEL_OPEN;
1016 channel_pre_open(c, readset, writeset);
1017 } else if (ret == -1) {
1018 logit("X11 connection rejected because of wrong authentication.");
1019 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1020 chan_read_failed(c);
1021 buffer_clear(&c->input);
1023 buffer_clear(&c->output);
1024 /* for proto v1, the peer will send an IEOF */
1026 chan_write_failed(c);
1028 c->type = SSH_CHANNEL_OPEN;
1029 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1034 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1036 if (c->istate == CHAN_INPUT_OPEN &&
1037 buffer_check_alloc(&c->input, CHAN_RBUF))
1038 FD_SET(c->rfd, readset);
1039 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1040 /* clear buffer immediately (discard any partial packet) */
1041 buffer_clear(&c->input);
1043 /* Start output drain. XXX just kill chan? */
1044 chan_rcvd_oclose(c);
1046 if (c->ostate == CHAN_OUTPUT_OPEN ||
1047 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1048 if (buffer_len(&c->output) > 0)
1049 FD_SET(c->wfd, writeset);
1050 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1055 /* try to decode a socks4 header */
1058 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1061 u_int len, have, i, found, need;
1066 u_int16_t dest_port;
1067 struct in_addr dest_addr;
1070 debug2("channel %d: decode socks4", c->self);
1072 have = buffer_len(&c->input);
1073 len = sizeof(s4_req);
1076 p = buffer_ptr(&c->input);
1079 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1080 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1081 debug2("channel %d: socks4a request", c->self);
1082 /* ... and needs an extra string (the hostname) */
1085 /* Check for terminating NUL on the string(s) */
1086 for (found = 0, i = len; i < have; i++) {
1093 /* the peer is probably sending garbage */
1094 debug("channel %d: decode socks4: too long",
1101 buffer_get(&c->input, (char *)&s4_req.version, 1);
1102 buffer_get(&c->input, (char *)&s4_req.command, 1);
1103 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1104 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1105 have = buffer_len(&c->input);
1106 p = buffer_ptr(&c->input);
1108 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1109 len++; /* trailing '\0' */
1111 fatal("channel %d: decode socks4: len %d > have %d",
1112 c->self, len, have);
1113 strlcpy(username, p, sizeof(username));
1114 buffer_consume(&c->input, len);
1116 if (c->path != NULL) {
1120 if (need == 1) { /* SOCKS4: one string */
1121 host = inet_ntoa(s4_req.dest_addr);
1122 c->path = xstrdup(host);
1123 } else { /* SOCKS4A: two strings */
1124 have = buffer_len(&c->input);
1125 p = buffer_ptr(&c->input);
1127 debug2("channel %d: decode socks4a: host %s/%d",
1129 len++; /* trailing '\0' */
1131 fatal("channel %d: decode socks4a: len %d > have %d",
1132 c->self, len, have);
1133 if (len > NI_MAXHOST) {
1134 error("channel %d: hostname \"%.100s\" too long",
1138 c->path = xstrdup(p);
1139 buffer_consume(&c->input, len);
1141 c->host_port = ntohs(s4_req.dest_port);
1143 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1144 c->self, c->path, c->host_port, s4_req.command);
1146 if (s4_req.command != 1) {
1147 debug("channel %d: cannot handle: %s cn %d",
1148 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1151 s4_rsp.version = 0; /* vn: 0 for reply */
1152 s4_rsp.command = 90; /* cd: req granted */
1153 s4_rsp.dest_port = 0; /* ignored */
1154 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1155 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1159 /* try to decode a socks5 header */
1160 #define SSH_SOCKS5_AUTHDONE 0x1000
1161 #define SSH_SOCKS5_NOAUTH 0x00
1162 #define SSH_SOCKS5_IPV4 0x01
1163 #define SSH_SOCKS5_DOMAIN 0x03
1164 #define SSH_SOCKS5_IPV6 0x04
1165 #define SSH_SOCKS5_CONNECT 0x01
1166 #define SSH_SOCKS5_SUCCESS 0x00
1170 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1178 u_int16_t dest_port;
1179 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1180 u_int have, need, i, found, nmethods, addrlen, af;
1182 debug2("channel %d: decode socks5", c->self);
1183 p = buffer_ptr(&c->input);
1186 have = buffer_len(&c->input);
1187 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1188 /* format: ver | nmethods | methods */
1192 if (have < nmethods + 2)
1194 /* look for method: "NO AUTHENTICATION REQUIRED" */
1195 for (found = 0, i = 2; i < nmethods + 2; i++) {
1196 if (p[i] == SSH_SOCKS5_NOAUTH) {
1202 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1206 buffer_consume(&c->input, nmethods + 2);
1207 buffer_put_char(&c->output, 0x05); /* version */
1208 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1209 FD_SET(c->sock, writeset);
1210 c->flags |= SSH_SOCKS5_AUTHDONE;
1211 debug2("channel %d: socks5 auth done", c->self);
1212 return 0; /* need more */
1214 debug2("channel %d: socks5 post auth", c->self);
1215 if (have < sizeof(s5_req)+1)
1216 return 0; /* need more */
1217 memcpy(&s5_req, p, sizeof(s5_req));
1218 if (s5_req.version != 0x05 ||
1219 s5_req.command != SSH_SOCKS5_CONNECT ||
1220 s5_req.reserved != 0x00) {
1221 debug2("channel %d: only socks5 connect supported", c->self);
1224 switch (s5_req.atyp){
1225 case SSH_SOCKS5_IPV4:
1229 case SSH_SOCKS5_DOMAIN:
1230 addrlen = p[sizeof(s5_req)];
1233 case SSH_SOCKS5_IPV6:
1238 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1241 need = sizeof(s5_req) + addrlen + 2;
1242 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1246 buffer_consume(&c->input, sizeof(s5_req));
1247 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1248 buffer_consume(&c->input, 1); /* host string length */
1249 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1250 buffer_get(&c->input, (char *)&dest_port, 2);
1251 dest_addr[addrlen] = '\0';
1252 if (c->path != NULL) {
1256 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1257 if (addrlen >= NI_MAXHOST) {
1258 error("channel %d: dynamic request: socks5 hostname "
1259 "\"%.100s\" too long", c->self, dest_addr);
1262 c->path = xstrdup(dest_addr);
1264 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1266 c->path = xstrdup(ntop);
1268 c->host_port = ntohs(dest_port);
1270 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1271 c->self, c->path, c->host_port, s5_req.command);
1273 s5_rsp.version = 0x05;
1274 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1275 s5_rsp.reserved = 0; /* ignored */
1276 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1277 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1278 dest_port = 0; /* ignored */
1280 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1281 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1282 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1287 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1292 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1295 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1296 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1297 0, "stdio-forward", /*nonblock*/0);
1299 c->path = xstrdup(host_to_connect);
1300 c->host_port = port_to_connect;
1301 c->listening_port = 0;
1304 channel_register_fds(c, in, out, -1, 0, 1, 0);
1305 port_open_helper(c, "direct-tcpip");
1310 /* dynamic port forwarding */
1312 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1318 have = buffer_len(&c->input);
1319 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1320 /* buffer_dump(&c->input); */
1321 /* check if the fixed size part of the packet is in buffer. */
1324 FD_SET(c->sock, readset);
1327 /* try to guess the protocol */
1328 p = buffer_ptr(&c->input);
1331 ret = channel_decode_socks4(c, readset, writeset);
1334 ret = channel_decode_socks5(c, readset, writeset);
1342 } else if (ret == 0) {
1343 debug2("channel %d: pre_dynamic: need more", c->self);
1345 FD_SET(c->sock, readset);
1347 /* switch to the next state */
1348 c->type = SSH_CHANNEL_OPENING;
1349 port_open_helper(c, "direct-tcpip");
1353 /* This is our fake X11 server socket. */
1356 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1359 struct sockaddr_storage addr;
1362 char buf[16384], *remote_ipaddr;
1365 if (FD_ISSET(c->sock, readset)) {
1366 debug("X11 connection requested.");
1367 addrlen = sizeof(addr);
1368 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1369 if (c->single_connection) {
1370 debug2("single_connection: closing X11 listener.");
1371 channel_close_fd(&c->sock);
1375 error("accept: %.100s", strerror(errno));
1378 set_nodelay(newsock);
1379 remote_ipaddr = get_peer_ipaddr(newsock);
1380 remote_port = get_peer_port(newsock);
1381 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1382 remote_ipaddr, remote_port);
1384 nc = channel_new("accepted x11 socket",
1385 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1386 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1388 packet_start(SSH2_MSG_CHANNEL_OPEN);
1389 packet_put_cstring("x11");
1390 packet_put_int(nc->self);
1391 packet_put_int(nc->local_window_max);
1392 packet_put_int(nc->local_maxpacket);
1393 /* originator ipaddr and port */
1394 packet_put_cstring(remote_ipaddr);
1395 if (datafellows & SSH_BUG_X11FWD) {
1396 debug2("ssh2 x11 bug compat mode");
1398 packet_put_int(remote_port);
1402 packet_start(SSH_SMSG_X11_OPEN);
1403 packet_put_int(nc->self);
1404 if (packet_get_protocol_flags() &
1405 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1406 packet_put_cstring(buf);
1409 xfree(remote_ipaddr);
1414 port_open_helper(Channel *c, char *rtype)
1418 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1419 int remote_port = get_peer_port(c->sock);
1421 if (remote_port == -1) {
1422 /* Fake addr/port to appease peers that validate it (Tectia) */
1423 xfree(remote_ipaddr);
1424 remote_ipaddr = xstrdup("127.0.0.1");
1425 remote_port = 65535;
1428 direct = (strcmp(rtype, "direct-tcpip") == 0);
1430 snprintf(buf, sizeof buf,
1431 "%s: listening port %d for %.100s port %d, "
1432 "connect from %.200s port %d",
1433 rtype, c->listening_port, c->path, c->host_port,
1434 remote_ipaddr, remote_port);
1436 xfree(c->remote_name);
1437 c->remote_name = xstrdup(buf);
1440 packet_start(SSH2_MSG_CHANNEL_OPEN);
1441 packet_put_cstring(rtype);
1442 packet_put_int(c->self);
1443 packet_put_int(c->local_window_max);
1444 packet_put_int(c->local_maxpacket);
1446 /* target host, port */
1447 packet_put_cstring(c->path);
1448 packet_put_int(c->host_port);
1450 /* listen address, port */
1451 packet_put_cstring(c->path);
1452 packet_put_int(c->listening_port);
1454 /* originator host and port */
1455 packet_put_cstring(remote_ipaddr);
1456 packet_put_int((u_int)remote_port);
1459 packet_start(SSH_MSG_PORT_OPEN);
1460 packet_put_int(c->self);
1461 packet_put_cstring(c->path);
1462 packet_put_int(c->host_port);
1463 if (packet_get_protocol_flags() &
1464 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1465 packet_put_cstring(c->remote_name);
1468 xfree(remote_ipaddr);
1472 channel_set_reuseaddr(int fd)
1477 * Set socket options.
1478 * Allow local port reuse in TIME_WAIT.
1480 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1481 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1485 * This socket is listening for connections to a forwarded TCP/IP port.
1489 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1492 struct sockaddr_storage addr;
1493 int newsock, nextstate;
1497 if (FD_ISSET(c->sock, readset)) {
1498 debug("Connection to port %d forwarding "
1499 "to %.100s port %d requested.",
1500 c->listening_port, c->path, c->host_port);
1502 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1503 nextstate = SSH_CHANNEL_OPENING;
1504 rtype = "forwarded-tcpip";
1506 if (c->host_port == 0) {
1507 nextstate = SSH_CHANNEL_DYNAMIC;
1508 rtype = "dynamic-tcpip";
1510 nextstate = SSH_CHANNEL_OPENING;
1511 rtype = "direct-tcpip";
1515 addrlen = sizeof(addr);
1516 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1518 error("accept: %.100s", strerror(errno));
1521 set_nodelay(newsock);
1522 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1523 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1524 nc->listening_port = c->listening_port;
1525 nc->host_port = c->host_port;
1526 if (c->path != NULL)
1527 nc->path = xstrdup(c->path);
1529 if (nextstate != SSH_CHANNEL_DYNAMIC)
1530 port_open_helper(nc, rtype);
1535 * This is the authentication agent socket listening for connections from
1540 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1544 struct sockaddr_storage addr;
1547 if (FD_ISSET(c->sock, readset)) {
1548 addrlen = sizeof(addr);
1549 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1551 error("accept from auth socket: %.100s", strerror(errno));
1554 nc = channel_new("accepted auth socket",
1555 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1556 c->local_window_max, c->local_maxpacket,
1557 0, "accepted auth socket", 1);
1559 packet_start(SSH2_MSG_CHANNEL_OPEN);
1560 packet_put_cstring("auth-agent@openssh.com");
1561 packet_put_int(nc->self);
1562 packet_put_int(c->local_window_max);
1563 packet_put_int(c->local_maxpacket);
1565 packet_start(SSH_SMSG_AGENT_OPEN);
1566 packet_put_int(nc->self);
1574 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1577 socklen_t sz = sizeof(err);
1579 if (FD_ISSET(c->sock, writeset)) {
1580 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1582 error("getsockopt SO_ERROR failed");
1585 debug("channel %d: connected to %s port %d",
1586 c->self, c->connect_ctx.host, c->connect_ctx.port);
1587 channel_connect_ctx_free(&c->connect_ctx);
1588 c->type = SSH_CHANNEL_OPEN;
1590 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1591 packet_put_int(c->remote_id);
1592 packet_put_int(c->self);
1593 packet_put_int(c->local_window);
1594 packet_put_int(c->local_maxpacket);
1596 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1597 packet_put_int(c->remote_id);
1598 packet_put_int(c->self);
1601 debug("channel %d: connection failed: %s",
1602 c->self, strerror(err));
1603 /* Try next address, if any */
1604 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1606 c->sock = c->rfd = c->wfd = sock;
1607 channel_max_fd = channel_find_maxfd();
1610 /* Exhausted all addresses */
1611 error("connect_to %.100s port %d: failed.",
1612 c->connect_ctx.host, c->connect_ctx.port);
1613 channel_connect_ctx_free(&c->connect_ctx);
1615 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1616 packet_put_int(c->remote_id);
1617 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1618 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1619 packet_put_cstring(strerror(err));
1620 packet_put_cstring("");
1623 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1624 packet_put_int(c->remote_id);
1634 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1636 char buf[CHAN_RBUF];
1639 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1640 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1642 len = read(c->rfd, buf, sizeof(buf));
1643 if (len < 0 && (errno == EINTR ||
1644 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1646 #ifndef PTY_ZEROREAD
1649 if ((!c->isatty && len <= 0) ||
1650 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1652 debug2("channel %d: read<=0 rfd %d len %d",
1653 c->self, c->rfd, len);
1654 if (c->type != SSH_CHANNEL_OPEN) {
1655 debug2("channel %d: not open", c->self);
1658 } else if (compat13) {
1659 buffer_clear(&c->output);
1660 c->type = SSH_CHANNEL_INPUT_DRAINING;
1661 debug2("channel %d: input draining.", c->self);
1663 chan_read_failed(c);
1667 if (c->input_filter != NULL) {
1668 if (c->input_filter(c, buf, len) == -1) {
1669 debug2("channel %d: filter stops", c->self);
1670 chan_read_failed(c);
1672 } else if (c->datagram) {
1673 buffer_put_string(&c->input, buf, len);
1675 buffer_append(&c->input, buf, len);
1683 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1686 u_char *data = NULL, *buf;
1690 /* Send buffered output data to the socket. */
1692 FD_ISSET(c->wfd, writeset) &&
1693 buffer_len(&c->output) > 0) {
1694 if (c->output_filter != NULL) {
1695 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1696 debug2("channel %d: filter stops", c->self);
1697 if (c->type != SSH_CHANNEL_OPEN)
1700 chan_write_failed(c);
1703 } else if (c->datagram) {
1704 buf = data = buffer_get_string(&c->output, &dlen);
1706 buf = data = buffer_ptr(&c->output);
1707 dlen = buffer_len(&c->output);
1711 /* ignore truncated writes, datagrams might get lost */
1712 c->local_consumed += dlen + 4;
1713 len = write(c->wfd, buf, dlen);
1715 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1716 errno == EWOULDBLOCK))
1719 if (c->type != SSH_CHANNEL_OPEN)
1722 chan_write_failed(c);
1728 /* XXX: Later AIX versions can't push as much data to tty */
1729 if (compat20 && c->wfd_isatty)
1730 dlen = MIN(dlen, 8*1024);
1733 len = write(c->wfd, buf, dlen);
1735 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1738 if (c->type != SSH_CHANNEL_OPEN) {
1739 debug2("channel %d: not open", c->self);
1742 } else if (compat13) {
1743 buffer_clear(&c->output);
1744 debug2("channel %d: input draining.", c->self);
1745 c->type = SSH_CHANNEL_INPUT_DRAINING;
1747 chan_write_failed(c);
1751 #ifndef BROKEN_TCGETATTR_ICANON
1752 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1753 if (tcgetattr(c->wfd, &tio) == 0 &&
1754 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1756 * Simulate echo to reduce the impact of
1757 * traffic analysis. We need to match the
1758 * size of a SSH2_MSG_CHANNEL_DATA message
1759 * (4 byte channel id + buf)
1761 packet_send_ignore(4 + len);
1766 buffer_consume(&c->output, len);
1767 if (compat20 && len > 0) {
1768 c->local_consumed += len;
1775 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1777 char buf[CHAN_RBUF];
1780 /** XXX handle drain efd, too */
1782 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1783 FD_ISSET(c->efd, writeset) &&
1784 buffer_len(&c->extended) > 0) {
1785 len = write(c->efd, buffer_ptr(&c->extended),
1786 buffer_len(&c->extended));
1787 debug2("channel %d: written %d to efd %d",
1788 c->self, len, c->efd);
1789 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1790 errno == EWOULDBLOCK))
1793 debug2("channel %d: closing write-efd %d",
1795 channel_close_fd(&c->efd);
1797 buffer_consume(&c->extended, len);
1798 c->local_consumed += len;
1800 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1801 (c->detach_close || FD_ISSET(c->efd, readset))) {
1802 len = read(c->efd, buf, sizeof(buf));
1803 debug2("channel %d: read %d from efd %d",
1804 c->self, len, c->efd);
1805 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1806 errno == EWOULDBLOCK) && !c->detach_close)))
1809 debug2("channel %d: closing read-efd %d",
1811 channel_close_fd(&c->efd);
1813 buffer_append(&c->extended, buf, len);
1821 channel_check_window(Channel *c)
1823 if (c->type == SSH_CHANNEL_OPEN &&
1824 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1825 ((c->local_window_max - c->local_window >
1826 c->local_maxpacket*3) ||
1827 c->local_window < c->local_window_max/2) &&
1828 c->local_consumed > 0) {
1831 /* Adjust max window size if we are in a dynamic environment. */
1832 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1834 * Grow the window somewhat aggressively to maintain
1837 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1838 c->local_window_max += addition;
1840 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1841 packet_put_int(c->remote_id);
1842 packet_put_int(c->local_consumed + addition);
1844 debug2("channel %d: window %d sent adjust %d",
1845 c->self, c->local_window,
1847 c->local_window += c->local_consumed + addition;
1848 c->local_consumed = 0;
1854 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1856 channel_handle_rfd(c, readset, writeset);
1857 channel_handle_wfd(c, readset, writeset);
1860 channel_handle_efd(c, readset, writeset);
1861 channel_check_window(c);
1865 read_mux(Channel *c, u_int need)
1867 char buf[CHAN_RBUF];
1871 if (buffer_len(&c->input) < need) {
1872 rlen = need - buffer_len(&c->input);
1873 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1875 if (errno != EINTR && errno != EAGAIN) {
1876 debug2("channel %d: ctl read<=0 rfd %d len %d",
1877 c->self, c->rfd, len);
1878 chan_read_failed(c);
1882 buffer_append(&c->input, buf, len);
1884 return buffer_len(&c->input);
1888 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1894 fatal("%s: entered with !compat20", __func__);
1896 if (c->rfd != -1 && FD_ISSET(c->rfd, readset) &&
1897 (c->istate == CHAN_INPUT_OPEN ||
1898 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1900 * Don't not read past the precise end of packets to
1901 * avoid disrupting fd passing.
1903 if (read_mux(c, 4) < 4) /* read header */
1905 need = get_u32(buffer_ptr(&c->input));
1906 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1907 if (need > CHANNEL_MUX_MAX_PACKET) {
1908 debug2("channel %d: packet too big %u > %u",
1909 c->self, CHANNEL_MUX_MAX_PACKET, need);
1910 chan_rcvd_oclose(c);
1913 if (read_mux(c, need + 4) < need + 4) /* read body */
1915 if (c->mux_rcb(c) != 0) {
1916 debug("channel %d: mux_rcb failed", c->self);
1922 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1923 buffer_len(&c->output) > 0) {
1924 len = write(c->wfd, buffer_ptr(&c->output),
1925 buffer_len(&c->output));
1926 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1932 buffer_consume(&c->output, len);
1937 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1940 struct sockaddr_storage addr;
1946 if (!FD_ISSET(c->sock, readset))
1949 debug("multiplexing control connection");
1952 * Accept connection on control socket
1954 memset(&addr, 0, sizeof(addr));
1955 addrlen = sizeof(addr);
1956 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1958 error("%s accept: %s", __func__, strerror(errno));
1962 if (getpeereid(newsock, &euid, &egid) < 0) {
1963 error("%s getpeereid failed: %s", __func__,
1968 if ((euid != 0) && (getuid() != euid)) {
1969 error("multiplex uid mismatch: peer euid %u != uid %u",
1970 (u_int)euid, (u_int)getuid());
1974 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1975 newsock, newsock, -1, c->local_window_max,
1976 c->local_maxpacket, 0, "mux-control", 1);
1977 nc->mux_rcb = c->mux_rcb;
1978 debug3("%s: new mux channel %d fd %d", __func__,
1979 nc->self, nc->sock);
1980 /* establish state */
1982 /* mux state transitions must not elicit protocol messages */
1983 nc->flags |= CHAN_LOCAL;
1988 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1992 /* Send buffered output data to the socket. */
1993 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1994 len = write(c->sock, buffer_ptr(&c->output),
1995 buffer_len(&c->output));
1997 buffer_clear(&c->output);
1999 buffer_consume(&c->output, len);
2004 channel_handler_init_20(void)
2006 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2007 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2008 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2009 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2010 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2011 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2012 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2013 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2014 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2015 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2017 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2018 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2019 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2020 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2021 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2022 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2023 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2024 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2025 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2029 channel_handler_init_13(void)
2031 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2032 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2033 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2034 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2035 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2036 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2037 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2038 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2039 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2041 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2042 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2043 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2044 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2045 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2046 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2047 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2051 channel_handler_init_15(void)
2053 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2054 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2055 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2056 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2057 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2058 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2059 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2061 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2062 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2063 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2064 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2065 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2066 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2070 channel_handler_init(void)
2074 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2075 channel_pre[i] = NULL;
2076 channel_post[i] = NULL;
2079 channel_handler_init_20();
2081 channel_handler_init_13();
2083 channel_handler_init_15();
2086 /* gc dead channels */
2088 channel_garbage_collect(Channel *c)
2092 if (c->detach_user != NULL) {
2093 if (!chan_is_dead(c, c->detach_close))
2095 debug2("channel %d: gc: notify user", c->self);
2096 c->detach_user(c->self, NULL);
2097 /* if we still have a callback */
2098 if (c->detach_user != NULL)
2100 debug2("channel %d: gc: user detached", c->self);
2102 if (!chan_is_dead(c, 1))
2104 debug2("channel %d: garbage collecting", c->self);
2109 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
2111 static int did_init = 0;
2116 channel_handler_init();
2119 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2124 if (ftab == channel_pre)
2129 if (ftab[c->type] != NULL)
2130 (*ftab[c->type])(c, readset, writeset);
2131 channel_garbage_collect(c);
2136 * Allocate/update select bitmasks and add any bits relevant to channels in
2140 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2141 u_int *nallocp, int rekeying)
2143 u_int n, sz, nfdset;
2145 n = MAX(*maxfdp, channel_max_fd);
2147 nfdset = howmany(n+1, NFDBITS);
2148 /* Explicitly test here, because xrealloc isn't always called */
2149 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2150 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2151 sz = nfdset * sizeof(fd_mask);
2153 /* perhaps check sz < nalloc/2 and shrink? */
2154 if (*readsetp == NULL || sz > *nallocp) {
2155 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2156 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2160 memset(*readsetp, 0, sz);
2161 memset(*writesetp, 0, sz);
2164 channel_handler(channel_pre, *readsetp, *writesetp);
2168 * After select, perform any appropriate operations for channels which have
2172 channel_after_select(fd_set *readset, fd_set *writeset)
2174 channel_handler(channel_post, readset, writeset);
2178 /* If there is data to send to the connection, enqueue some of it now. */
2180 channel_output_poll(void)
2185 for (i = 0; i < channels_alloc; i++) {
2191 * We are only interested in channels that can have buffered
2195 if (c->type != SSH_CHANNEL_OPEN &&
2196 c->type != SSH_CHANNEL_INPUT_DRAINING)
2199 if (c->type != SSH_CHANNEL_OPEN)
2203 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2204 /* XXX is this true? */
2205 debug3("channel %d: will not send data after close", c->self);
2209 /* Get the amount of buffered data for this channel. */
2210 if ((c->istate == CHAN_INPUT_OPEN ||
2211 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2212 (len = buffer_len(&c->input)) > 0) {
2218 data = buffer_get_string(&c->input,
2220 packet_start(SSH2_MSG_CHANNEL_DATA);
2221 packet_put_int(c->remote_id);
2222 packet_put_string(data, dlen);
2224 c->remote_window -= dlen + 4;
2230 * Send some data for the other side over the secure
2234 if (len > c->remote_window)
2235 len = c->remote_window;
2236 if (len > c->remote_maxpacket)
2237 len = c->remote_maxpacket;
2239 if (packet_is_interactive()) {
2243 /* Keep the packets at reasonable size. */
2244 if (len > packet_get_maxsize()/2)
2245 len = packet_get_maxsize()/2;
2249 packet_start(compat20 ?
2250 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2251 packet_put_int(c->remote_id);
2252 packet_put_string(buffer_ptr(&c->input), len);
2254 buffer_consume(&c->input, len);
2255 c->remote_window -= len;
2257 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2259 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2261 * input-buffer is empty and read-socket shutdown:
2262 * tell peer, that we will not send more data: send IEOF.
2263 * hack for extended data: delay EOF if EFD still in use.
2265 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2266 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2267 c->self, c->efd, buffer_len(&c->extended));
2271 /* Send extended data, i.e. stderr */
2273 !(c->flags & CHAN_EOF_SENT) &&
2274 c->remote_window > 0 &&
2275 (len = buffer_len(&c->extended)) > 0 &&
2276 c->extended_usage == CHAN_EXTENDED_READ) {
2277 debug2("channel %d: rwin %u elen %u euse %d",
2278 c->self, c->remote_window, buffer_len(&c->extended),
2280 if (len > c->remote_window)
2281 len = c->remote_window;
2282 if (len > c->remote_maxpacket)
2283 len = c->remote_maxpacket;
2284 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2285 packet_put_int(c->remote_id);
2286 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2287 packet_put_string(buffer_ptr(&c->extended), len);
2289 buffer_consume(&c->extended, len);
2290 c->remote_window -= len;
2291 debug2("channel %d: sent ext data %d", c->self, len);
2297 /* -- protocol input */
2301 channel_input_data(int type, u_int32_t seq, void *ctxt)
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 * Ignore data for protocol > 1.3 if output end is no longer open.
2324 * For protocol 2 the sending side is reducing its window as it sends
2325 * data, so we must 'fake' consumption of the data in order to ensure
2326 * that window updates are sent back. Otherwise the connection might
2329 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2331 c->local_window -= data_len;
2332 c->local_consumed += data_len;
2338 if (data_len > c->local_maxpacket) {
2339 logit("channel %d: rcvd big packet %d, maxpack %d",
2340 c->self, data_len, c->local_maxpacket);
2342 if (data_len > c->local_window) {
2343 logit("channel %d: rcvd too much data %d, win %d",
2344 c->self, data_len, c->local_window);
2347 c->local_window -= data_len;
2350 buffer_put_string(&c->output, data, data_len);
2352 buffer_append(&c->output, data, data_len);
2358 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2362 u_int data_len, tcode;
2365 /* Get the channel number and verify it. */
2366 id = packet_get_int();
2367 c = channel_lookup(id);
2370 packet_disconnect("Received extended_data for bad channel %d.", id);
2371 if (c->type != SSH_CHANNEL_OPEN) {
2372 logit("channel %d: ext data for non open", id);
2375 if (c->flags & CHAN_EOF_RCVD) {
2376 if (datafellows & SSH_BUG_EXTEOF)
2377 debug("channel %d: accepting ext data after eof", id);
2379 packet_disconnect("Received extended_data after EOF "
2380 "on channel %d.", id);
2382 tcode = packet_get_int();
2384 c->extended_usage != CHAN_EXTENDED_WRITE ||
2385 tcode != SSH2_EXTENDED_DATA_STDERR) {
2386 logit("channel %d: bad ext data", c->self);
2389 data = packet_get_string(&data_len);
2391 if (data_len > c->local_window) {
2392 logit("channel %d: rcvd too much extended_data %d, win %d",
2393 c->self, data_len, c->local_window);
2397 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2398 c->local_window -= data_len;
2399 buffer_append(&c->extended, data, data_len);
2405 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2410 id = packet_get_int();
2412 c = channel_lookup(id);
2414 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2417 /* XXX force input close */
2418 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2419 debug("channel %d: FORCE input drain", c->self);
2420 c->istate = CHAN_INPUT_WAIT_DRAIN;
2421 if (buffer_len(&c->input) == 0)
2429 channel_input_close(int type, u_int32_t seq, void *ctxt)
2434 id = packet_get_int();
2436 c = channel_lookup(id);
2438 packet_disconnect("Received close for nonexistent channel %d.", id);
2441 * Send a confirmation that we have closed the channel and no more
2442 * data is coming for it.
2444 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2445 packet_put_int(c->remote_id);
2449 * If the channel is in closed state, we have sent a close request,
2450 * and the other side will eventually respond with a confirmation.
2451 * Thus, we cannot free the channel here, because then there would be
2452 * no-one to receive the confirmation. The channel gets freed when
2453 * the confirmation arrives.
2455 if (c->type != SSH_CHANNEL_CLOSED) {
2457 * Not a closed channel - mark it as draining, which will
2458 * cause it to be freed later.
2460 buffer_clear(&c->input);
2461 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2465 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2468 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2470 int id = packet_get_int();
2471 Channel *c = channel_lookup(id);
2475 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2476 chan_rcvd_oclose(c);
2481 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2483 int id = packet_get_int();
2484 Channel *c = channel_lookup(id);
2488 packet_disconnect("Received close confirmation for "
2489 "out-of-range channel %d.", id);
2490 if (c->type != SSH_CHANNEL_CLOSED)
2491 packet_disconnect("Received close confirmation for "
2492 "non-closed channel %d (type %d).", id, c->type);
2498 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2503 id = packet_get_int();
2504 c = channel_lookup(id);
2506 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2507 packet_disconnect("Received open confirmation for "
2508 "non-opening channel %d.", id);
2509 remote_id = packet_get_int();
2510 /* Record the remote channel number and mark that the channel is now open. */
2511 c->remote_id = remote_id;
2512 c->type = SSH_CHANNEL_OPEN;
2515 c->remote_window = packet_get_int();
2516 c->remote_maxpacket = packet_get_int();
2517 if (c->open_confirm) {
2518 debug2("callback start");
2519 c->open_confirm(c->self, c->open_confirm_ctx);
2520 debug2("callback done");
2522 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2523 c->remote_window, c->remote_maxpacket);
2529 reason2txt(int reason)
2532 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2533 return "administratively prohibited";
2534 case SSH2_OPEN_CONNECT_FAILED:
2535 return "connect failed";
2536 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2537 return "unknown channel type";
2538 case SSH2_OPEN_RESOURCE_SHORTAGE:
2539 return "resource shortage";
2541 return "unknown reason";
2546 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2549 char *msg = NULL, *lang = NULL;
2552 id = packet_get_int();
2553 c = channel_lookup(id);
2555 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2556 packet_disconnect("Received open failure for "
2557 "non-opening channel %d.", id);
2559 reason = packet_get_int();
2560 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2561 msg = packet_get_string(NULL);
2562 lang = packet_get_string(NULL);
2564 logit("channel %d: open failed: %s%s%s", id,
2565 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2572 /* Schedule the channel for cleanup/deletion. */
2578 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2587 /* Get the channel number and verify it. */
2588 id = packet_get_int();
2589 c = channel_lookup(id);
2592 logit("Received window adjust for non-open channel %d.", id);
2595 adjust = packet_get_int();
2597 debug2("channel %d: rcvd adjust %u", id, adjust);
2598 c->remote_window += adjust;
2603 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2607 char *host, *originator_string;
2610 remote_id = packet_get_int();
2611 host = packet_get_string(NULL);
2612 host_port = packet_get_int();
2614 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2615 originator_string = packet_get_string(NULL);
2617 originator_string = xstrdup("unknown (remote did not supply name)");
2620 c = channel_connect_to(host, host_port,
2621 "connected socket", originator_string);
2622 xfree(originator_string);
2625 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2626 packet_put_int(remote_id);
2629 c->remote_id = remote_id;
2634 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2637 struct channel_confirm *cc;
2640 /* Reset keepalive timeout */
2641 packet_set_alive_timeouts(0);
2643 id = packet_get_int();
2646 debug2("channel_input_status_confirm: type %d id %d", type, id);
2648 if ((c = channel_lookup(id)) == NULL) {
2649 logit("channel_input_status_confirm: %d: unknown", id);
2653 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2655 cc->cb(type, c, cc->ctx);
2656 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2657 bzero(cc, sizeof(*cc));
2661 /* -- tcp forwarding */
2664 channel_set_af(int af)
2670 channel_set_hpn(int disabled, u_int buf_size)
2672 hpn_disabled = disabled;
2673 buffer_size = buf_size;
2674 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2675 hpn_disabled, buffer_size);
2679 channel_setup_fwd_listener(int type, const char *listen_addr,
2680 u_short listen_port, int *allocated_listen_port,
2681 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2684 int sock, r, success = 0, wildcard = 0, is_client;
2685 struct addrinfo hints, *ai, *aitop;
2686 const char *host, *addr;
2687 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2690 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2691 listen_addr : host_to_connect;
2692 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2695 error("No forward host name.");
2698 if (strlen(host) >= NI_MAXHOST) {
2699 error("Forward host name too long.");
2704 * Determine whether or not a port forward listens to loopback,
2705 * specified address or wildcard. On the client, a specified bind
2706 * address will always override gateway_ports. On the server, a
2707 * gateway_ports of 1 (``yes'') will override the client's
2708 * specification and force a wildcard bind, whereas a value of 2
2709 * (``clientspecified'') will bind to whatever address the client
2712 * Special-case listen_addrs are:
2714 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2715 * "" (empty string), "*" -> wildcard v4/v6
2716 * "localhost" -> loopback v4/v6
2719 if (listen_addr == NULL) {
2720 /* No address specified: default to gateway_ports setting */
2723 } else if (gateway_ports || is_client) {
2724 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2725 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2726 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2727 (!is_client && gateway_ports == 1))
2729 else if (strcmp(listen_addr, "localhost") != 0)
2733 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2734 type, wildcard, (addr == NULL) ? "NULL" : addr);
2737 * getaddrinfo returns a loopback address if the hostname is
2738 * set to NULL and hints.ai_flags is not AI_PASSIVE
2740 memset(&hints, 0, sizeof(hints));
2741 hints.ai_family = IPv4or6;
2742 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2743 hints.ai_socktype = SOCK_STREAM;
2744 snprintf(strport, sizeof strport, "%d", listen_port);
2745 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2747 /* This really shouldn't happen */
2748 packet_disconnect("getaddrinfo: fatal error: %s",
2749 ssh_gai_strerror(r));
2751 error("channel_setup_fwd_listener: "
2752 "getaddrinfo(%.64s): %s", addr,
2753 ssh_gai_strerror(r));
2757 if (allocated_listen_port != NULL)
2758 *allocated_listen_port = 0;
2759 for (ai = aitop; ai; ai = ai->ai_next) {
2760 switch (ai->ai_family) {
2762 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2766 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2773 * If allocating a port for -R forwards, then use the
2774 * same port for all address families.
2776 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2777 allocated_listen_port != NULL && *allocated_listen_port > 0)
2778 *lport_p = htons(*allocated_listen_port);
2780 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2781 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2782 error("channel_setup_fwd_listener: getnameinfo failed");
2785 /* Create a port to listen for the host. */
2786 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2788 /* this is no error since kernel may not support ipv6 */
2789 verbose("socket: %.100s", strerror(errno));
2793 channel_set_reuseaddr(sock);
2794 if (ai->ai_family == AF_INET6)
2795 sock_set_v6only(sock);
2797 debug("Local forwarding listening on %s port %s.",
2800 /* Bind the socket to the address. */
2801 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2802 /* address can be in use ipv6 address is already bound */
2804 error("bind: %.100s", strerror(errno));
2806 verbose("bind: %.100s", strerror(errno));
2811 /* Start listening for connections on the socket. */
2812 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2813 error("listen: %.100s", strerror(errno));
2819 * listen_port == 0 requests a dynamically allocated port -
2820 * record what we got.
2822 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2823 allocated_listen_port != NULL &&
2824 *allocated_listen_port == 0) {
2825 *allocated_listen_port = get_sock_port(sock, 1);
2826 debug("Allocated listen port %d",
2827 *allocated_listen_port);
2831 * Allocate a channel number for the socket. Explicitly test
2832 * for hpn disabled option. If true use smaller window size.
2835 c = channel_new("port listener", type, sock, sock, -1,
2836 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2837 0, "port listener", 1);
2839 c = channel_new("port listener", type, sock, sock, -1,
2840 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2841 0, "port listener", 1);
2842 c->path = xstrdup(host);
2843 c->host_port = port_to_connect;
2844 c->listening_port = listen_port;
2848 error("channel_setup_fwd_listener: cannot listen to port: %d",
2850 freeaddrinfo(aitop);
2855 channel_cancel_rport_listener(const char *host, u_short port)
2860 for (i = 0; i < channels_alloc; i++) {
2861 Channel *c = channels[i];
2863 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2864 strcmp(c->path, host) == 0 && c->listening_port == port) {
2865 debug2("%s: close channel %d", __func__, i);
2874 /* protocol local port fwd, used by ssh (and sshd in v1) */
2876 channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2877 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2879 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2880 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2884 /* protocol v2 remote port fwd, used by sshd */
2886 channel_setup_remote_fwd_listener(const char *listen_address,
2887 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2889 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2890 listen_address, listen_port, allocated_listen_port,
2891 NULL, 0, gateway_ports);
2895 * Initiate forwarding of connections to port "port" on remote host through
2896 * the secure channel to host:port from local side.
2900 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2901 const char *host_to_connect, u_short port_to_connect)
2903 int type, success = 0;
2905 /* Record locally that connection to this host/port is permitted. */
2906 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2907 fatal("channel_request_remote_forwarding: too many forwards");
2909 /* Send the forward request to the remote side. */
2911 const char *address_to_bind;
2912 if (listen_host == NULL) {
2913 if (datafellows & SSH_BUG_RFWD_ADDR)
2914 address_to_bind = "127.0.0.1";
2916 address_to_bind = "localhost";
2917 } else if (*listen_host == '\0' ||
2918 strcmp(listen_host, "*") == 0) {
2919 if (datafellows & SSH_BUG_RFWD_ADDR)
2920 address_to_bind = "0.0.0.0";
2922 address_to_bind = "";
2924 address_to_bind = listen_host;
2926 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2927 packet_put_cstring("tcpip-forward");
2928 packet_put_char(1); /* boolean: want reply */
2929 packet_put_cstring(address_to_bind);
2930 packet_put_int(listen_port);
2932 packet_write_wait();
2933 /* Assume that server accepts the request */
2936 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2937 packet_put_int(listen_port);
2938 packet_put_cstring(host_to_connect);
2939 packet_put_int(port_to_connect);
2941 packet_write_wait();
2943 /* Wait for response from the remote side. */
2944 type = packet_read();
2946 case SSH_SMSG_SUCCESS:
2949 case SSH_SMSG_FAILURE:
2952 /* Unknown packet */
2953 packet_disconnect("Protocol error for port forward request:"
2954 "received packet type %d.", type);
2958 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2959 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2960 permitted_opens[num_permitted_opens].listen_port = listen_port;
2961 num_permitted_opens++;
2963 return (success ? 0 : -1);
2967 * Request cancellation of remote forwarding of connection host:port from
2971 channel_request_rforward_cancel(const char *host, u_short port)
2978 for (i = 0; i < num_permitted_opens; i++) {
2979 if (permitted_opens[i].host_to_connect != NULL &&
2980 permitted_opens[i].listen_port == port)
2983 if (i >= num_permitted_opens) {
2984 debug("%s: requested forward not found", __func__);
2987 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2988 packet_put_cstring("cancel-tcpip-forward");
2990 packet_put_cstring(host == NULL ? "" : host);
2991 packet_put_int(port);
2994 permitted_opens[i].listen_port = 0;
2995 permitted_opens[i].port_to_connect = 0;
2996 xfree(permitted_opens[i].host_to_connect);
2997 permitted_opens[i].host_to_connect = NULL;
3001 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3002 * listening for the port, and sends back a success reply (or disconnect
3003 * message if there was an error).
3006 channel_input_port_forward_request(int is_root, int gateway_ports)
3008 u_short port, host_port;
3012 /* Get arguments from the packet. */
3013 port = packet_get_int();
3014 hostname = packet_get_string(NULL);
3015 host_port = packet_get_int();
3019 * Check that an unprivileged user is not trying to forward a
3022 if (port < IPPORT_RESERVED && !is_root)
3024 "Requested forwarding of port %d but user is not root.",
3027 packet_disconnect("Dynamic forwarding denied.");
3030 /* Initiate forwarding */
3031 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3032 host_port, gateway_ports);
3034 /* Free the argument string. */
3037 return (success ? 0 : -1);
3041 * Permits opening to any host/port if permitted_opens[] is empty. This is
3042 * usually called by the server, because the user could connect to any port
3043 * anyway, and the server has no way to know but to trust the client anyway.
3046 channel_permit_all_opens(void)
3048 if (num_permitted_opens == 0)
3049 all_opens_permitted = 1;
3053 channel_add_permitted_opens(char *host, int port)
3055 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
3056 fatal("channel_add_permitted_opens: too many forwards");
3057 debug("allow port forwarding to host %s port %d", host, port);
3059 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3060 permitted_opens[num_permitted_opens].port_to_connect = port;
3061 num_permitted_opens++;
3063 all_opens_permitted = 0;
3067 channel_add_adm_permitted_opens(char *host, int port)
3069 if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
3070 fatal("channel_add_adm_permitted_opens: too many forwards");
3071 debug("config allows port forwarding to host %s port %d", host, port);
3073 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3075 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3076 return ++num_adm_permitted_opens;
3080 channel_clear_permitted_opens(void)
3084 for (i = 0; i < num_permitted_opens; i++)
3085 if (permitted_opens[i].host_to_connect != NULL)
3086 xfree(permitted_opens[i].host_to_connect);
3087 num_permitted_opens = 0;
3091 channel_clear_adm_permitted_opens(void)
3095 for (i = 0; i < num_adm_permitted_opens; i++)
3096 if (permitted_adm_opens[i].host_to_connect != NULL)
3097 xfree(permitted_adm_opens[i].host_to_connect);
3098 num_adm_permitted_opens = 0;
3102 channel_print_adm_permitted_opens(void)
3106 printf("permitopen");
3107 if (num_adm_permitted_opens == 0) {
3111 for (i = 0; i < num_adm_permitted_opens; i++)
3112 if (permitted_adm_opens[i].host_to_connect != NULL)
3113 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3114 permitted_adm_opens[i].port_to_connect);
3118 /* Try to start non-blocking connect to next host in cctx list */
3120 connect_next(struct channel_connect *cctx)
3122 int sock, saved_errno;
3123 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3125 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3126 if (cctx->ai->ai_family != AF_INET &&
3127 cctx->ai->ai_family != AF_INET6)
3129 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3130 ntop, sizeof(ntop), strport, sizeof(strport),
3131 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3132 error("connect_next: getnameinfo failed");
3135 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3136 cctx->ai->ai_protocol)) == -1) {
3137 if (cctx->ai->ai_next == NULL)
3138 error("socket: %.100s", strerror(errno));
3140 verbose("socket: %.100s", strerror(errno));
3143 if (set_nonblock(sock) == -1)
3144 fatal("%s: set_nonblock(%d)", __func__, sock);
3145 if (connect(sock, cctx->ai->ai_addr,
3146 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3147 debug("connect_next: host %.100s ([%.100s]:%s): "
3148 "%.100s", cctx->host, ntop, strport,
3150 saved_errno = errno;
3152 errno = saved_errno;
3153 continue; /* fail -- try next */
3155 debug("connect_next: host %.100s ([%.100s]:%s) "
3156 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3157 cctx->ai = cctx->ai->ai_next;
3165 channel_connect_ctx_free(struct channel_connect *cctx)
3169 freeaddrinfo(cctx->aitop);
3170 bzero(cctx, sizeof(*cctx));
3172 cctx->ai = cctx->aitop = NULL;
3175 /* Return CONNECTING channel to remote host, port */
3177 connect_to(const char *host, u_short port, char *ctype, char *rname)
3179 struct addrinfo hints;
3182 char strport[NI_MAXSERV];
3183 struct channel_connect cctx;
3186 memset(&cctx, 0, sizeof(cctx));
3187 memset(&hints, 0, sizeof(hints));
3188 hints.ai_family = IPv4or6;
3189 hints.ai_socktype = SOCK_STREAM;
3190 snprintf(strport, sizeof strport, "%d", port);
3191 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3192 error("connect_to %.100s: unknown host (%s)", host,
3193 ssh_gai_strerror(gaierr));
3197 cctx.host = xstrdup(host);
3199 cctx.ai = cctx.aitop;
3201 if ((sock = connect_next(&cctx)) == -1) {
3202 error("connect to %.100s port %d failed: %s",
3203 host, port, strerror(errno));
3204 channel_connect_ctx_free(&cctx);
3207 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3208 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3209 c->connect_ctx = cctx;
3214 channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3218 for (i = 0; i < num_permitted_opens; i++) {
3219 if (permitted_opens[i].host_to_connect != NULL &&
3220 permitted_opens[i].listen_port == listen_port) {
3222 permitted_opens[i].host_to_connect,
3223 permitted_opens[i].port_to_connect, ctype, rname);
3226 error("WARNING: Server requests forwarding for unknown listen_port %d",
3231 /* Check if connecting to that port is permitted and connect. */
3233 channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3235 int i, permit, permit_adm = 1;
3237 permit = all_opens_permitted;
3239 for (i = 0; i < num_permitted_opens; i++)
3240 if (permitted_opens[i].host_to_connect != NULL &&
3241 permitted_opens[i].port_to_connect == port &&
3242 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3246 if (num_adm_permitted_opens > 0) {
3248 for (i = 0; i < num_adm_permitted_opens; i++)
3249 if (permitted_adm_opens[i].host_to_connect != NULL &&
3250 permitted_adm_opens[i].port_to_connect == port &&
3251 strcmp(permitted_adm_opens[i].host_to_connect, host)
3256 if (!permit || !permit_adm) {
3257 logit("Received request to connect to host %.100s port %d, "
3258 "but the request was denied.", host, port);
3261 return connect_to(host, port, ctype, rname);
3265 channel_send_window_changes(void)
3270 for (i = 0; i < channels_alloc; i++) {
3271 if (channels[i] == NULL || !channels[i]->client_tty ||
3272 channels[i]->type != SSH_CHANNEL_OPEN)
3274 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3276 channel_request_start(i, "window-change", 0);
3277 packet_put_int((u_int)ws.ws_col);
3278 packet_put_int((u_int)ws.ws_row);
3279 packet_put_int((u_int)ws.ws_xpixel);
3280 packet_put_int((u_int)ws.ws_ypixel);
3285 /* -- X11 forwarding */
3288 * Creates an internet domain socket for listening for X11 connections.
3289 * Returns 0 and a suitable display number for the DISPLAY variable
3290 * stored in display_numberp , or -1 if an error occurs.
3293 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3294 int single_connection, u_int *display_numberp, int **chanids)
3297 int display_number, sock;
3299 struct addrinfo hints, *ai, *aitop;
3300 char strport[NI_MAXSERV];
3301 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3303 if (chanids == NULL)
3306 for (display_number = x11_display_offset;
3307 display_number < MAX_DISPLAYS;
3309 port = 6000 + display_number;
3310 memset(&hints, 0, sizeof(hints));
3311 hints.ai_family = IPv4or6;
3312 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3313 hints.ai_socktype = SOCK_STREAM;
3314 snprintf(strport, sizeof strport, "%d", port);
3315 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3316 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3319 for (ai = aitop; ai; ai = ai->ai_next) {
3320 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3322 sock = socket(ai->ai_family, ai->ai_socktype,
3325 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
3326 error("socket: %.100s", strerror(errno));
3327 freeaddrinfo(aitop);
3330 debug("x11_create_display_inet: Socket family %d not supported",
3335 if (ai->ai_family == AF_INET6)
3336 sock_set_v6only(sock);
3337 if (x11_use_localhost)
3338 channel_set_reuseaddr(sock);
3339 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3340 debug2("bind port %d: %.100s", port, strerror(errno));
3343 for (n = 0; n < num_socks; n++) {
3349 socks[num_socks++] = sock;
3350 if (num_socks == NUM_SOCKS)
3353 freeaddrinfo(aitop);
3357 if (display_number >= MAX_DISPLAYS) {
3358 error("Failed to allocate internet-domain X11 display socket.");
3361 /* Start listening for connections on the socket. */
3362 for (n = 0; n < num_socks; n++) {
3364 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3365 error("listen: %.100s", strerror(errno));
3371 /* Allocate a channel for each socket. */
3372 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3373 for (n = 0; n < num_socks; n++) {
3376 nc = channel_new("x11 listener",
3377 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3378 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3379 0, "X11 inet listener", 1);
3381 nc = channel_new("x11 listener",
3382 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3383 buffer_size, CHAN_X11_PACKET_DEFAULT,
3384 0, "X11 inet listener", 1);
3385 nc->single_connection = single_connection;
3386 (*chanids)[n] = nc->self;
3390 /* Return the display number for the DISPLAY environment variable. */
3391 *display_numberp = display_number;
3396 connect_local_xsocket_path(const char *pathname)
3399 struct sockaddr_un addr;
3401 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3403 error("socket: %.100s", strerror(errno));
3404 memset(&addr, 0, sizeof(addr));
3405 addr.sun_family = AF_UNIX;
3406 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3407 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3410 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3415 connect_local_xsocket(u_int dnr)
3418 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3419 return connect_local_xsocket_path(buf);
3423 x11_connect_display(void)
3425 u_int display_number;
3426 const char *display;
3427 char buf[1024], *cp;
3428 struct addrinfo hints, *ai, *aitop;
3429 char strport[NI_MAXSERV];
3430 int gaierr, sock = 0;
3432 /* Try to open a socket for the local X server. */
3433 display = getenv("DISPLAY");
3435 error("DISPLAY not set.");
3439 * Now we decode the value of the DISPLAY variable and make a
3440 * connection to the real X server.
3443 /* Check if the display is from launchd. */
3445 if (strncmp(display, "/tmp/launch", 11) == 0) {
3446 sock = connect_local_xsocket_path(display);
3450 /* OK, we now have a connection to the display. */
3455 * Check if it is a unix domain socket. Unix domain displays are in
3456 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3458 if (strncmp(display, "unix:", 5) == 0 ||
3459 display[0] == ':') {
3460 /* Connect to the unix domain socket. */
3461 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3462 error("Could not parse display number from DISPLAY: %.100s",
3466 /* Create a socket. */
3467 sock = connect_local_xsocket(display_number);
3471 /* OK, we now have a connection to the display. */
3475 * Connect to an inet socket. The DISPLAY value is supposedly
3476 * hostname:d[.s], where hostname may also be numeric IP address.
3478 strlcpy(buf, display, sizeof(buf));
3479 cp = strchr(buf, ':');
3481 error("Could not find ':' in DISPLAY: %.100s", display);
3485 /* buf now contains the host name. But first we parse the display number. */
3486 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3487 error("Could not parse display number from DISPLAY: %.100s",
3492 /* Look up the host address */
3493 memset(&hints, 0, sizeof(hints));
3494 hints.ai_family = IPv4or6;
3495 hints.ai_socktype = SOCK_STREAM;
3496 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3497 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3498 error("%.100s: unknown host. (%s)", buf,
3499 ssh_gai_strerror(gaierr));
3502 for (ai = aitop; ai; ai = ai->ai_next) {
3503 /* Create a socket. */
3504 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3506 debug2("socket: %.100s", strerror(errno));
3509 /* Connect it to the display. */
3510 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3511 debug2("connect %.100s port %u: %.100s", buf,
3512 6000 + display_number, strerror(errno));
3519 freeaddrinfo(aitop);
3521 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3530 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3531 * the remote channel number. We should do whatever we want, and respond
3532 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3537 x11_input_open(int type, u_int32_t seq, void *ctxt)
3540 int remote_id, sock = 0;
3543 debug("Received X11 open request.");
3545 remote_id = packet_get_int();
3547 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3548 remote_host = packet_get_string(NULL);
3550 remote_host = xstrdup("unknown (remote did not supply name)");
3554 /* Obtain a connection to the real X display. */
3555 sock = x11_connect_display();
3557 /* Allocate a channel for this connection. */
3558 c = channel_new("connected x11 socket",
3559 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3561 c->remote_id = remote_id;
3566 /* Send refusal to the remote host. */
3567 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3568 packet_put_int(remote_id);
3570 /* Send a confirmation to the remote host. */
3571 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3572 packet_put_int(remote_id);
3573 packet_put_int(c->self);
3578 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3581 deny_input_open(int type, u_int32_t seq, void *ctxt)
3583 int rchan = packet_get_int();
3586 case SSH_SMSG_AGENT_OPEN:
3587 error("Warning: ssh server tried agent forwarding.");
3589 case SSH_SMSG_X11_OPEN:
3590 error("Warning: ssh server tried X11 forwarding.");
3593 error("deny_input_open: type %d", type);
3596 error("Warning: this is probably a break-in attempt by a malicious server.");
3597 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3598 packet_put_int(rchan);
3603 * Requests forwarding of X11 connections, generates fake authentication
3604 * data, and enables authentication spoofing.
3605 * This should be called in the client only.
3608 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3609 const char *proto, const char *data)
3611 u_int data_len = (u_int) strlen(data) / 2;
3618 if (x11_saved_display == NULL)
3619 x11_saved_display = xstrdup(disp);
3620 else if (strcmp(disp, x11_saved_display) != 0) {
3621 error("x11_request_forwarding_with_spoofing: different "
3622 "$DISPLAY already forwarded");
3626 cp = strchr(disp, ':');
3628 cp = strchr(cp, '.');
3630 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3634 if (x11_saved_proto == NULL) {
3635 /* Save protocol name. */
3636 x11_saved_proto = xstrdup(proto);
3638 * Extract real authentication data and generate fake data
3639 * of the same length.
3641 x11_saved_data = xmalloc(data_len);
3642 x11_fake_data = xmalloc(data_len);
3643 for (i = 0; i < data_len; i++) {
3644 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3645 fatal("x11_request_forwarding: bad "
3646 "authentication data: %.100s", data);
3649 x11_saved_data[i] = value;
3650 x11_fake_data[i] = rnd & 0xff;
3653 x11_saved_data_len = data_len;
3654 x11_fake_data_len = data_len;
3657 /* Convert the fake data into hex. */
3658 new_data = tohex(x11_fake_data, data_len);
3660 /* Send the request packet. */
3662 channel_request_start(client_session_id, "x11-req", 0);
3663 packet_put_char(0); /* XXX bool single connection */
3665 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3667 packet_put_cstring(proto);
3668 packet_put_cstring(new_data);
3669 packet_put_int(screen_number);
3671 packet_write_wait();
3676 /* -- agent forwarding */
3678 /* Sends a message to the server to request authentication fd forwarding. */
3681 auth_request_forwarding(void)
3683 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3685 packet_write_wait();