1 /* $OpenBSD: channels.c,v 1.331 2014/02/26 20:29:29 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.
46 #include <sys/types.h>
47 #include <sys/ioctl.h>
49 #include <sys/socket.h>
50 #ifdef HAVE_SYS_TIME_H
51 # include <sys/time.h>
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
67 #include "openbsd-compat/sys-queue.h"
81 #include "pathnames.h"
86 * Pointer to an array containing all allocated channels. The array is
87 * dynamically extended as needed.
89 static Channel **channels = NULL;
92 * Size of the channel array. All slots of the array must always be
93 * initialized (at least the type field); unused slots set to NULL
95 static u_int channels_alloc = 0;
98 * Maximum file descriptor value used in any of the channels. This is
99 * updated in channel_new.
101 static int channel_max_fd = 0;
104 /* -- tcp forwarding */
107 * Data structure for storing which hosts are permitted for forward requests.
108 * The local sides of any remote forwards are stored in this array to prevent
109 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
110 * network (which might be behind a firewall).
113 char *host_to_connect; /* Connect to 'host'. */
114 u_short port_to_connect; /* Connect to 'port'. */
115 u_short listen_port; /* Remote side should listen port number. */
118 /* List of all permitted host/port pairs to connect by the user. */
119 static ForwardPermission *permitted_opens = NULL;
121 /* List of all permitted host/port pairs to connect by the admin. */
122 static ForwardPermission *permitted_adm_opens = NULL;
124 /* Number of permitted host/port pairs in the array permitted by the user. */
125 static int num_permitted_opens = 0;
127 /* Number of permitted host/port pair in the array permitted by the admin. */
128 static int num_adm_permitted_opens = 0;
130 /* special-case port number meaning allow any port */
131 #define FWD_PERMIT_ANY_PORT 0
134 * If this is true, all opens are permitted. This is the case on the server
135 * on which we have to trust the client anyway, and the user could do
136 * anything after logging in anyway.
138 static int all_opens_permitted = 0;
141 /* -- X11 forwarding */
143 /* Maximum number of fake X11 displays to try. */
144 #define MAX_DISPLAYS 1000
146 /* Saved X11 local (client) display. */
147 static char *x11_saved_display = NULL;
149 /* Saved X11 authentication protocol name. */
150 static char *x11_saved_proto = NULL;
152 /* Saved X11 authentication data. This is the real data. */
153 static char *x11_saved_data = NULL;
154 static u_int x11_saved_data_len = 0;
157 * Fake X11 authentication data. This is what the server will be sending us;
158 * we should replace any occurrences of this by the real data.
160 static u_char *x11_fake_data = NULL;
161 static u_int x11_fake_data_len;
164 /* -- agent forwarding */
168 /* AF_UNSPEC or AF_INET or AF_INET6 */
169 static int IPv4or6 = AF_UNSPEC;
172 static void port_open_helper(Channel *c, char *rtype);
174 /* non-blocking connect helpers */
175 static int connect_next(struct channel_connect *);
176 static void channel_connect_ctx_free(struct channel_connect *);
180 static int hpn_disabled = 0;
181 static u_int buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
183 /* -- channel core */
186 channel_by_id(int id)
190 if (id < 0 || (u_int)id >= channels_alloc) {
191 logit("channel_by_id: %d: bad id", id);
196 logit("channel_by_id: %d: bad id: channel free", id);
203 * Returns the channel if it is allowed to receive protocol messages.
204 * Private channels, like listening sockets, may not receive messages.
207 channel_lookup(int id)
211 if ((c = channel_by_id(id)) == NULL)
215 case SSH_CHANNEL_X11_OPEN:
216 case SSH_CHANNEL_LARVAL:
217 case SSH_CHANNEL_CONNECTING:
218 case SSH_CHANNEL_DYNAMIC:
219 case SSH_CHANNEL_OPENING:
220 case SSH_CHANNEL_OPEN:
221 case SSH_CHANNEL_INPUT_DRAINING:
222 case SSH_CHANNEL_OUTPUT_DRAINING:
223 case SSH_CHANNEL_ABANDONED:
226 logit("Non-public channel %d, type %d.", id, c->type);
231 * Register filedescriptors for a channel, used when allocating a channel or
232 * when the channel consumer/producer is ready, e.g. shell exec'd
235 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
236 int extusage, int nonblock, int is_tty)
238 /* Update the maximum file descriptor value. */
239 channel_max_fd = MAX(channel_max_fd, rfd);
240 channel_max_fd = MAX(channel_max_fd, wfd);
241 channel_max_fd = MAX(channel_max_fd, efd);
244 fcntl(rfd, F_SETFD, FD_CLOEXEC);
245 if (wfd != -1 && wfd != rfd)
246 fcntl(wfd, F_SETFD, FD_CLOEXEC);
247 if (efd != -1 && efd != rfd && efd != wfd)
248 fcntl(efd, F_SETFD, FD_CLOEXEC);
252 c->sock = (rfd == wfd) ? rfd : -1;
254 c->extended_usage = extusage;
256 if ((c->isatty = is_tty) != 0)
257 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
259 /* XXX: Later AIX versions can't push as much data to tty */
260 c->wfd_isatty = is_tty || isatty(c->wfd);
263 /* enable nonblocking mode */
275 * Allocate a new channel object and set its type and socket. This will cause
276 * remote_name to be freed.
279 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
280 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
286 /* Do initial allocation if this is the first call. */
287 if (channels_alloc == 0) {
289 channels = xcalloc(channels_alloc, sizeof(Channel *));
290 for (i = 0; i < channels_alloc; i++)
293 /* Try to find a free slot where to put the new channel. */
294 for (found = -1, i = 0; i < channels_alloc; i++)
295 if (channels[i] == NULL) {
296 /* Found a free slot. */
301 /* There are no free slots. Take last+1 slot and expand the array. */
302 found = channels_alloc;
303 if (channels_alloc > 10000)
304 fatal("channel_new: internal error: channels_alloc %d "
305 "too big.", channels_alloc);
306 channels = xrealloc(channels, channels_alloc + 10,
308 channels_alloc += 10;
309 debug2("channel: expanding %d", channels_alloc);
310 for (i = found; i < channels_alloc; i++)
313 /* Initialize and return new channel. */
314 c = channels[found] = xcalloc(1, sizeof(Channel));
315 buffer_init(&c->input);
316 buffer_init(&c->output);
317 buffer_init(&c->extended);
319 c->listening_addr = NULL;
320 c->listening_port = 0;
321 c->ostate = CHAN_OUTPUT_OPEN;
322 c->istate = CHAN_INPUT_OPEN;
324 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
329 c->dynamic_window = 0;
330 c->local_window = window;
331 c->local_window_max = window;
332 c->local_consumed = 0;
333 c->local_maxpacket = maxpack;
335 c->remote_name = xstrdup(remote_name);
336 c->remote_window = 0;
337 c->remote_maxpacket = 0;
339 c->single_connection = 0;
340 c->detach_user = NULL;
342 c->open_confirm = NULL;
343 c->open_confirm_ctx = NULL;
344 c->input_filter = NULL;
345 c->output_filter = NULL;
346 c->filter_ctx = NULL;
347 c->filter_cleanup = NULL;
352 c->delayed = 1; /* prevent call to channel_post handler */
353 TAILQ_INIT(&c->status_confirms);
354 debug("channel %d: new [%s]", found, remote_name);
359 channel_find_maxfd(void)
365 for (i = 0; i < channels_alloc; i++) {
368 max = MAX(max, c->rfd);
369 max = MAX(max, c->wfd);
370 max = MAX(max, c->efd);
377 channel_close_fd(int *fdp)
379 int ret = 0, fd = *fdp;
384 if (fd == channel_max_fd)
385 channel_max_fd = channel_find_maxfd();
390 /* Close all channel fd/socket. */
392 channel_close_fds(Channel *c)
394 channel_close_fd(&c->sock);
395 channel_close_fd(&c->rfd);
396 channel_close_fd(&c->wfd);
397 channel_close_fd(&c->efd);
400 /* Free the channel and close its fd/socket. */
402 channel_free(Channel *c)
406 struct channel_confirm *cc;
408 for (n = 0, i = 0; i < channels_alloc; i++)
411 debug("channel %d: free: %s, nchannels %u", c->self,
412 c->remote_name ? c->remote_name : "???", n);
414 s = channel_open_message();
415 debug3("channel %d: status: %s", c->self, s);
419 shutdown(c->sock, SHUT_RDWR);
420 channel_close_fds(c);
421 buffer_free(&c->input);
422 buffer_free(&c->output);
423 buffer_free(&c->extended);
424 free(c->remote_name);
425 c->remote_name = NULL;
428 free(c->listening_addr);
429 c->listening_addr = NULL;
430 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
431 if (cc->abandon_cb != NULL)
432 cc->abandon_cb(c, cc->ctx);
433 TAILQ_REMOVE(&c->status_confirms, cc, entry);
434 explicit_bzero(cc, sizeof(*cc));
437 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
438 c->filter_cleanup(c->self, c->filter_ctx);
439 channels[c->self] = NULL;
444 channel_free_all(void)
448 for (i = 0; i < channels_alloc; i++)
449 if (channels[i] != NULL)
450 channel_free(channels[i]);
454 * Closes the sockets/fds of all channels. This is used to close extra file
455 * descriptors after a fork.
458 channel_close_all(void)
462 for (i = 0; i < channels_alloc; i++)
463 if (channels[i] != NULL)
464 channel_close_fds(channels[i]);
468 * Stop listening to channels.
471 channel_stop_listening(void)
476 for (i = 0; i < channels_alloc; i++) {
480 case SSH_CHANNEL_AUTH_SOCKET:
481 case SSH_CHANNEL_PORT_LISTENER:
482 case SSH_CHANNEL_RPORT_LISTENER:
483 case SSH_CHANNEL_X11_LISTENER:
484 channel_close_fd(&c->sock);
493 * Returns true if no channel has too much buffered data, and false if one or
494 * more channel is overfull.
497 channel_not_very_much_buffered_data(void)
502 for (i = 0; i < channels_alloc; i++) {
504 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
507 buffer_len(&c->input) > packet_get_maxsize()) {
508 debug2("channel %d: big input buffer %d",
509 c->self, buffer_len(&c->input));
513 if (buffer_len(&c->output) > packet_get_maxsize()) {
514 debug2("channel %d: big output buffer %u > %u",
515 c->self, buffer_len(&c->output),
516 packet_get_maxsize());
524 /* Returns true if any channel is still open. */
526 channel_still_open(void)
531 for (i = 0; i < channels_alloc; i++) {
536 case SSH_CHANNEL_X11_LISTENER:
537 case SSH_CHANNEL_PORT_LISTENER:
538 case SSH_CHANNEL_RPORT_LISTENER:
539 case SSH_CHANNEL_MUX_LISTENER:
540 case SSH_CHANNEL_CLOSED:
541 case SSH_CHANNEL_AUTH_SOCKET:
542 case SSH_CHANNEL_DYNAMIC:
543 case SSH_CHANNEL_CONNECTING:
544 case SSH_CHANNEL_ZOMBIE:
545 case SSH_CHANNEL_ABANDONED:
547 case SSH_CHANNEL_LARVAL:
549 fatal("cannot happen: SSH_CHANNEL_LARVAL");
551 case SSH_CHANNEL_OPENING:
552 case SSH_CHANNEL_OPEN:
553 case SSH_CHANNEL_X11_OPEN:
554 case SSH_CHANNEL_MUX_CLIENT:
556 case SSH_CHANNEL_INPUT_DRAINING:
557 case SSH_CHANNEL_OUTPUT_DRAINING:
559 fatal("cannot happen: OUT_DRAIN");
562 fatal("channel_still_open: bad channel type %d", c->type);
569 /* Returns the id of an open channel suitable for keepaliving */
571 channel_find_open(void)
576 for (i = 0; i < channels_alloc; i++) {
578 if (c == NULL || c->remote_id < 0)
581 case SSH_CHANNEL_CLOSED:
582 case SSH_CHANNEL_DYNAMIC:
583 case SSH_CHANNEL_X11_LISTENER:
584 case SSH_CHANNEL_PORT_LISTENER:
585 case SSH_CHANNEL_RPORT_LISTENER:
586 case SSH_CHANNEL_MUX_LISTENER:
587 case SSH_CHANNEL_MUX_CLIENT:
588 case SSH_CHANNEL_OPENING:
589 case SSH_CHANNEL_CONNECTING:
590 case SSH_CHANNEL_ZOMBIE:
591 case SSH_CHANNEL_ABANDONED:
593 case SSH_CHANNEL_LARVAL:
594 case SSH_CHANNEL_AUTH_SOCKET:
595 case SSH_CHANNEL_OPEN:
596 case SSH_CHANNEL_X11_OPEN:
598 case SSH_CHANNEL_INPUT_DRAINING:
599 case SSH_CHANNEL_OUTPUT_DRAINING:
601 fatal("cannot happen: OUT_DRAIN");
604 fatal("channel_find_open: bad channel type %d", c->type);
613 * Returns a message describing the currently open forwarded connections,
614 * suitable for sending to the client. The message contains crlf pairs for
618 channel_open_message(void)
625 buffer_init(&buffer);
626 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
627 buffer_append(&buffer, buf, strlen(buf));
628 for (i = 0; i < channels_alloc; i++) {
633 case SSH_CHANNEL_X11_LISTENER:
634 case SSH_CHANNEL_PORT_LISTENER:
635 case SSH_CHANNEL_RPORT_LISTENER:
636 case SSH_CHANNEL_CLOSED:
637 case SSH_CHANNEL_AUTH_SOCKET:
638 case SSH_CHANNEL_ZOMBIE:
639 case SSH_CHANNEL_ABANDONED:
640 case SSH_CHANNEL_MUX_CLIENT:
641 case SSH_CHANNEL_MUX_LISTENER:
643 case SSH_CHANNEL_LARVAL:
644 case SSH_CHANNEL_OPENING:
645 case SSH_CHANNEL_CONNECTING:
646 case SSH_CHANNEL_DYNAMIC:
647 case SSH_CHANNEL_OPEN:
648 case SSH_CHANNEL_X11_OPEN:
649 case SSH_CHANNEL_INPUT_DRAINING:
650 case SSH_CHANNEL_OUTPUT_DRAINING:
651 snprintf(buf, sizeof buf,
652 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
653 c->self, c->remote_name,
654 c->type, c->remote_id,
655 c->istate, buffer_len(&c->input),
656 c->ostate, buffer_len(&c->output),
657 c->rfd, c->wfd, c->ctl_chan);
658 buffer_append(&buffer, buf, strlen(buf));
661 fatal("channel_open_message: bad channel type %d", c->type);
665 buffer_append(&buffer, "\0", 1);
666 cp = xstrdup(buffer_ptr(&buffer));
667 buffer_free(&buffer);
672 channel_send_open(int id)
674 Channel *c = channel_lookup(id);
677 logit("channel_send_open: %d: bad id", id);
680 debug2("channel %d: send open", id);
681 packet_start(SSH2_MSG_CHANNEL_OPEN);
682 packet_put_cstring(c->ctype);
683 packet_put_int(c->self);
684 packet_put_int(c->local_window);
685 packet_put_int(c->local_maxpacket);
690 channel_request_start(int id, char *service, int wantconfirm)
692 Channel *c = channel_lookup(id);
695 logit("channel_request_start: %d: unknown channel id", id);
698 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
699 packet_start(SSH2_MSG_CHANNEL_REQUEST);
700 packet_put_int(c->remote_id);
701 packet_put_cstring(service);
702 packet_put_char(wantconfirm);
706 channel_register_status_confirm(int id, channel_confirm_cb *cb,
707 channel_confirm_abandon_cb *abandon_cb, void *ctx)
709 struct channel_confirm *cc;
712 if ((c = channel_lookup(id)) == NULL)
713 fatal("channel_register_expect: %d: bad id", id);
715 cc = xcalloc(1, sizeof(*cc));
717 cc->abandon_cb = abandon_cb;
719 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
723 channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
725 Channel *c = channel_lookup(id);
728 logit("channel_register_open_confirm: %d: bad id", id);
731 c->open_confirm = fn;
732 c->open_confirm_ctx = ctx;
736 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
738 Channel *c = channel_by_id(id);
741 logit("channel_register_cleanup: %d: bad id", id);
745 c->detach_close = do_close;
749 channel_cancel_cleanup(int id)
751 Channel *c = channel_by_id(id);
754 logit("channel_cancel_cleanup: %d: bad id", id);
757 c->detach_user = NULL;
762 channel_register_filter(int id, channel_infilter_fn *ifn,
763 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
765 Channel *c = channel_lookup(id);
768 logit("channel_register_filter: %d: bad id", id);
771 c->input_filter = ifn;
772 c->output_filter = ofn;
774 c->filter_cleanup = cfn;
778 channel_set_fds(int id, int rfd, int wfd, int efd,
779 int extusage, int nonblock, int is_tty, u_int window_max)
781 Channel *c = channel_lookup(id);
783 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
784 fatal("channel_activate for non-larval channel %d.", id);
785 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
786 c->type = SSH_CHANNEL_OPEN;
787 c->local_window = c->local_window_max = window_max;
788 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
789 packet_put_int(c->remote_id);
790 packet_put_int(c->local_window);
795 * 'channel_pre*' are called just before select() to add any bits relevant to
796 * channels in the select bitmasks.
799 * 'channel_post*': perform any appropriate operations for channels which
800 * have events pending.
802 typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
803 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
804 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
808 channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
810 FD_SET(c->sock, readset);
815 channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
817 debug3("channel %d: waiting for connection", c->self);
818 FD_SET(c->sock, writeset);
822 channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
824 if (buffer_len(&c->input) < packet_get_maxsize())
825 FD_SET(c->sock, readset);
826 if (buffer_len(&c->output) > 0)
827 FD_SET(c->sock, writeset);
831 channel_tcpwinsz(void)
838 /* If we are not on a socket return 128KB. */
839 if (!packet_connection_is_on_socket())
843 optsz = sizeof(tcpwinsz);
844 sd = packet_get_connection_in();
845 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
847 /* Return no more than the maximum buffer size. */
848 maxlen = buffer_get_max_len();
849 if ((ret == 0) && tcpwinsz > maxlen)
851 /* In case getsockopt() failed return a minimum. */
853 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
854 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
859 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
863 /* Check buffer limits. */
864 if (!c->tcpwinsz || c->dynamic_window > 0)
865 c->tcpwinsz = channel_tcpwinsz();
867 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
870 if (c->istate == CHAN_INPUT_OPEN &&
872 buffer_len(&c->input) < limit &&
873 buffer_check_alloc(&c->input, CHAN_RBUF))
874 FD_SET(c->rfd, readset);
875 if (c->ostate == CHAN_OUTPUT_OPEN ||
876 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
877 if (buffer_len(&c->output) > 0) {
878 FD_SET(c->wfd, writeset);
879 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
880 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
881 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
882 c->self, c->efd, buffer_len(&c->extended));
887 /** XXX check close conditions, too */
888 if (compat20 && c->efd != -1 &&
889 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
890 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
891 buffer_len(&c->extended) > 0)
892 FD_SET(c->efd, writeset);
893 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
894 (c->extended_usage == CHAN_EXTENDED_READ ||
895 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
896 buffer_len(&c->extended) < c->remote_window)
897 FD_SET(c->efd, readset);
899 /* XXX: What about efd? races? */
904 channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
906 if (buffer_len(&c->input) == 0) {
907 packet_start(SSH_MSG_CHANNEL_CLOSE);
908 packet_put_int(c->remote_id);
910 c->type = SSH_CHANNEL_CLOSED;
911 debug2("channel %d: closing after input drain.", c->self);
917 channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
919 if (buffer_len(&c->output) == 0)
922 FD_SET(c->sock, writeset);
926 * This is a special state for X11 authentication spoofing. An opened X11
927 * connection (when authentication spoofing is being done) remains in this
928 * state until the first packet has been completely read. The authentication
929 * data in that packet is then substituted by the real data if it matches the
930 * fake data, and the channel is put into normal mode.
931 * XXX All this happens at the client side.
932 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
935 x11_open_helper(Buffer *b)
938 u_int proto_len, data_len;
940 /* Check if the fixed size part of the packet is in buffer. */
941 if (buffer_len(b) < 12)
944 /* Parse the lengths of variable-length fields. */
946 if (ucp[0] == 0x42) { /* Byte order MSB first. */
947 proto_len = 256 * ucp[6] + ucp[7];
948 data_len = 256 * ucp[8] + ucp[9];
949 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
950 proto_len = ucp[6] + 256 * ucp[7];
951 data_len = ucp[8] + 256 * ucp[9];
953 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
958 /* Check if the whole packet is in buffer. */
960 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
963 /* Check if authentication protocol matches. */
964 if (proto_len != strlen(x11_saved_proto) ||
965 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
966 debug2("X11 connection uses different authentication protocol.");
969 /* Check if authentication data matches our fake data. */
970 if (data_len != x11_fake_data_len ||
971 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
972 x11_fake_data, x11_fake_data_len) != 0) {
973 debug2("X11 auth data does not match fake data.");
976 /* Check fake data length */
977 if (x11_fake_data_len != x11_saved_data_len) {
978 error("X11 fake_data_len %d != saved_data_len %d",
979 x11_fake_data_len, x11_saved_data_len);
983 * Received authentication protocol and data match
984 * our fake data. Substitute the fake data with real
987 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
988 x11_saved_data, x11_saved_data_len);
993 channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
995 int ret = x11_open_helper(&c->output);
998 /* Start normal processing for the channel. */
999 c->type = SSH_CHANNEL_OPEN;
1000 channel_pre_open_13(c, readset, writeset);
1001 } else if (ret == -1) {
1003 * We have received an X11 connection that has bad
1004 * authentication information.
1006 logit("X11 connection rejected because of wrong authentication.");
1007 buffer_clear(&c->input);
1008 buffer_clear(&c->output);
1009 channel_close_fd(&c->sock);
1011 c->type = SSH_CHANNEL_CLOSED;
1012 packet_start(SSH_MSG_CHANNEL_CLOSE);
1013 packet_put_int(c->remote_id);
1019 channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1021 int ret = x11_open_helper(&c->output);
1023 /* c->force_drain = 1; */
1026 c->type = SSH_CHANNEL_OPEN;
1027 channel_pre_open(c, readset, writeset);
1028 } else if (ret == -1) {
1029 logit("X11 connection rejected because of wrong authentication.");
1030 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1031 chan_read_failed(c);
1032 buffer_clear(&c->input);
1034 buffer_clear(&c->output);
1035 /* for proto v1, the peer will send an IEOF */
1037 chan_write_failed(c);
1039 c->type = SSH_CHANNEL_OPEN;
1040 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1045 channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1047 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1048 buffer_check_alloc(&c->input, CHAN_RBUF))
1049 FD_SET(c->rfd, readset);
1050 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1051 /* clear buffer immediately (discard any partial packet) */
1052 buffer_clear(&c->input);
1054 /* Start output drain. XXX just kill chan? */
1055 chan_rcvd_oclose(c);
1057 if (c->ostate == CHAN_OUTPUT_OPEN ||
1058 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1059 if (buffer_len(&c->output) > 0)
1060 FD_SET(c->wfd, writeset);
1061 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1066 /* try to decode a socks4 header */
1069 channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1072 u_int len, have, i, found, need;
1077 u_int16_t dest_port;
1078 struct in_addr dest_addr;
1081 debug2("channel %d: decode socks4", c->self);
1083 have = buffer_len(&c->input);
1084 len = sizeof(s4_req);
1087 p = buffer_ptr(&c->input);
1090 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1091 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1092 debug2("channel %d: socks4a request", c->self);
1093 /* ... and needs an extra string (the hostname) */
1096 /* Check for terminating NUL on the string(s) */
1097 for (found = 0, i = len; i < have; i++) {
1104 /* the peer is probably sending garbage */
1105 debug("channel %d: decode socks4: too long",
1112 buffer_get(&c->input, (char *)&s4_req.version, 1);
1113 buffer_get(&c->input, (char *)&s4_req.command, 1);
1114 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1115 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1116 have = buffer_len(&c->input);
1117 p = buffer_ptr(&c->input);
1118 if (memchr(p, '\0', have) == NULL)
1119 fatal("channel %d: decode socks4: user not nul terminated",
1122 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1123 len++; /* trailing '\0' */
1125 fatal("channel %d: decode socks4: len %d > have %d",
1126 c->self, len, have);
1127 strlcpy(username, p, sizeof(username));
1128 buffer_consume(&c->input, len);
1132 if (need == 1) { /* SOCKS4: one string */
1133 host = inet_ntoa(s4_req.dest_addr);
1134 c->path = xstrdup(host);
1135 } else { /* SOCKS4A: two strings */
1136 have = buffer_len(&c->input);
1137 p = buffer_ptr(&c->input);
1139 debug2("channel %d: decode socks4a: host %s/%d",
1141 len++; /* trailing '\0' */
1143 fatal("channel %d: decode socks4a: len %d > have %d",
1144 c->self, len, have);
1145 if (len > NI_MAXHOST) {
1146 error("channel %d: hostname \"%.100s\" too long",
1150 c->path = xstrdup(p);
1151 buffer_consume(&c->input, len);
1153 c->host_port = ntohs(s4_req.dest_port);
1155 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1156 c->self, c->path, c->host_port, s4_req.command);
1158 if (s4_req.command != 1) {
1159 debug("channel %d: cannot handle: %s cn %d",
1160 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1163 s4_rsp.version = 0; /* vn: 0 for reply */
1164 s4_rsp.command = 90; /* cd: req granted */
1165 s4_rsp.dest_port = 0; /* ignored */
1166 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1167 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1171 /* try to decode a socks5 header */
1172 #define SSH_SOCKS5_AUTHDONE 0x1000
1173 #define SSH_SOCKS5_NOAUTH 0x00
1174 #define SSH_SOCKS5_IPV4 0x01
1175 #define SSH_SOCKS5_DOMAIN 0x03
1176 #define SSH_SOCKS5_IPV6 0x04
1177 #define SSH_SOCKS5_CONNECT 0x01
1178 #define SSH_SOCKS5_SUCCESS 0x00
1182 channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1190 u_int16_t dest_port;
1191 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1193 u_int have, need, i, found, nmethods, addrlen, af;
1195 debug2("channel %d: decode socks5", c->self);
1196 p = buffer_ptr(&c->input);
1199 have = buffer_len(&c->input);
1200 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1201 /* format: ver | nmethods | methods */
1205 if (have < nmethods + 2)
1207 /* look for method: "NO AUTHENTICATION REQUIRED" */
1208 for (found = 0, i = 2; i < nmethods + 2; i++) {
1209 if (p[i] == SSH_SOCKS5_NOAUTH) {
1215 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1219 buffer_consume(&c->input, nmethods + 2);
1220 buffer_put_char(&c->output, 0x05); /* version */
1221 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1222 FD_SET(c->sock, writeset);
1223 c->flags |= SSH_SOCKS5_AUTHDONE;
1224 debug2("channel %d: socks5 auth done", c->self);
1225 return 0; /* need more */
1227 debug2("channel %d: socks5 post auth", c->self);
1228 if (have < sizeof(s5_req)+1)
1229 return 0; /* need more */
1230 memcpy(&s5_req, p, sizeof(s5_req));
1231 if (s5_req.version != 0x05 ||
1232 s5_req.command != SSH_SOCKS5_CONNECT ||
1233 s5_req.reserved != 0x00) {
1234 debug2("channel %d: only socks5 connect supported", c->self);
1237 switch (s5_req.atyp){
1238 case SSH_SOCKS5_IPV4:
1242 case SSH_SOCKS5_DOMAIN:
1243 addrlen = p[sizeof(s5_req)];
1246 case SSH_SOCKS5_IPV6:
1251 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1254 need = sizeof(s5_req) + addrlen + 2;
1255 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1259 buffer_consume(&c->input, sizeof(s5_req));
1260 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1261 buffer_consume(&c->input, 1); /* host string length */
1262 buffer_get(&c->input, &dest_addr, addrlen);
1263 buffer_get(&c->input, (char *)&dest_port, 2);
1264 dest_addr[addrlen] = '\0';
1267 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1268 if (addrlen >= NI_MAXHOST) {
1269 error("channel %d: dynamic request: socks5 hostname "
1270 "\"%.100s\" too long", c->self, dest_addr);
1273 c->path = xstrdup(dest_addr);
1275 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1277 c->path = xstrdup(ntop);
1279 c->host_port = ntohs(dest_port);
1281 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1282 c->self, c->path, c->host_port, s5_req.command);
1284 s5_rsp.version = 0x05;
1285 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1286 s5_rsp.reserved = 0; /* ignored */
1287 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1288 dest_port = 0; /* ignored */
1290 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1291 buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1292 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1297 channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1302 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1305 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1306 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1307 0, "stdio-forward", /*nonblock*/0);
1309 c->path = xstrdup(host_to_connect);
1310 c->host_port = port_to_connect;
1311 c->listening_port = 0;
1314 channel_register_fds(c, in, out, -1, 0, 1, 0);
1315 port_open_helper(c, "direct-tcpip");
1320 /* dynamic port forwarding */
1322 channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1328 have = buffer_len(&c->input);
1329 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1330 /* buffer_dump(&c->input); */
1331 /* check if the fixed size part of the packet is in buffer. */
1334 FD_SET(c->sock, readset);
1337 /* try to guess the protocol */
1338 p = buffer_ptr(&c->input);
1341 ret = channel_decode_socks4(c, readset, writeset);
1344 ret = channel_decode_socks5(c, readset, writeset);
1352 } else if (ret == 0) {
1353 debug2("channel %d: pre_dynamic: need more", c->self);
1355 FD_SET(c->sock, readset);
1357 /* switch to the next state */
1358 c->type = SSH_CHANNEL_OPENING;
1359 port_open_helper(c, "direct-tcpip");
1363 /* This is our fake X11 server socket. */
1366 channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1369 struct sockaddr_storage addr;
1370 int newsock, oerrno;
1372 char buf[16384], *remote_ipaddr;
1375 if (FD_ISSET(c->sock, readset)) {
1376 debug("X11 connection requested.");
1377 addrlen = sizeof(addr);
1378 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1379 if (c->single_connection) {
1381 debug2("single_connection: closing X11 listener.");
1382 channel_close_fd(&c->sock);
1387 if (errno != EINTR && errno != EWOULDBLOCK &&
1388 errno != ECONNABORTED)
1389 error("accept: %.100s", strerror(errno));
1390 if (errno == EMFILE || errno == ENFILE)
1391 c->notbefore = monotime() + 1;
1394 set_nodelay(newsock);
1395 remote_ipaddr = get_peer_ipaddr(newsock);
1396 remote_port = get_peer_port(newsock);
1397 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1398 remote_ipaddr, remote_port);
1400 nc = channel_new("accepted x11 socket",
1401 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1402 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1404 packet_start(SSH2_MSG_CHANNEL_OPEN);
1405 packet_put_cstring("x11");
1406 packet_put_int(nc->self);
1407 packet_put_int(nc->local_window_max);
1408 packet_put_int(nc->local_maxpacket);
1409 /* originator ipaddr and port */
1410 packet_put_cstring(remote_ipaddr);
1411 if (datafellows & SSH_BUG_X11FWD) {
1412 debug2("ssh2 x11 bug compat mode");
1414 packet_put_int(remote_port);
1418 packet_start(SSH_SMSG_X11_OPEN);
1419 packet_put_int(nc->self);
1420 if (packet_get_protocol_flags() &
1421 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1422 packet_put_cstring(buf);
1425 free(remote_ipaddr);
1430 port_open_helper(Channel *c, char *rtype)
1434 char *local_ipaddr = get_local_ipaddr(c->sock);
1435 int local_port = c->sock == -1 ? 65536 : get_sock_port(c->sock, 1);
1436 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1437 int remote_port = get_peer_port(c->sock);
1439 if (remote_port == -1) {
1440 /* Fake addr/port to appease peers that validate it (Tectia) */
1441 free(remote_ipaddr);
1442 remote_ipaddr = xstrdup("127.0.0.1");
1443 remote_port = 65535;
1446 direct = (strcmp(rtype, "direct-tcpip") == 0);
1448 snprintf(buf, sizeof buf,
1449 "%s: listening port %d for %.100s port %d, "
1450 "connect from %.200s port %d to %.100s port %d",
1451 rtype, c->listening_port, c->path, c->host_port,
1452 remote_ipaddr, remote_port, local_ipaddr, local_port);
1454 free(c->remote_name);
1455 c->remote_name = xstrdup(buf);
1458 packet_start(SSH2_MSG_CHANNEL_OPEN);
1459 packet_put_cstring(rtype);
1460 packet_put_int(c->self);
1461 packet_put_int(c->local_window_max);
1462 packet_put_int(c->local_maxpacket);
1464 /* target host, port */
1465 packet_put_cstring(c->path);
1466 packet_put_int(c->host_port);
1468 /* listen address, port */
1469 packet_put_cstring(c->path);
1470 packet_put_int(local_port);
1472 /* originator host and port */
1473 packet_put_cstring(remote_ipaddr);
1474 packet_put_int((u_int)remote_port);
1477 packet_start(SSH_MSG_PORT_OPEN);
1478 packet_put_int(c->self);
1479 packet_put_cstring(c->path);
1480 packet_put_int(c->host_port);
1481 if (packet_get_protocol_flags() &
1482 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1483 packet_put_cstring(c->remote_name);
1486 free(remote_ipaddr);
1491 channel_set_reuseaddr(int fd)
1496 * Set socket options.
1497 * Allow local port reuse in TIME_WAIT.
1499 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1500 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1504 * This socket is listening for connections to a forwarded TCP/IP port.
1508 channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1511 struct sockaddr_storage addr;
1512 int newsock, nextstate;
1516 if (FD_ISSET(c->sock, readset)) {
1517 debug("Connection to port %d forwarding "
1518 "to %.100s port %d requested.",
1519 c->listening_port, c->path, c->host_port);
1521 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1522 nextstate = SSH_CHANNEL_OPENING;
1523 rtype = "forwarded-tcpip";
1525 if (c->host_port == 0) {
1526 nextstate = SSH_CHANNEL_DYNAMIC;
1527 rtype = "dynamic-tcpip";
1529 nextstate = SSH_CHANNEL_OPENING;
1530 rtype = "direct-tcpip";
1534 addrlen = sizeof(addr);
1535 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1537 if (errno != EINTR && errno != EWOULDBLOCK &&
1538 errno != ECONNABORTED)
1539 error("accept: %.100s", strerror(errno));
1540 if (errno == EMFILE || errno == ENFILE)
1541 c->notbefore = monotime() + 1;
1544 set_nodelay(newsock);
1545 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1546 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1547 nc->listening_port = c->listening_port;
1548 nc->host_port = c->host_port;
1549 if (c->path != NULL)
1550 nc->path = xstrdup(c->path);
1552 if (nextstate != SSH_CHANNEL_DYNAMIC)
1553 port_open_helper(nc, rtype);
1558 * This is the authentication agent socket listening for connections from
1563 channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1567 struct sockaddr_storage addr;
1570 if (FD_ISSET(c->sock, readset)) {
1571 addrlen = sizeof(addr);
1572 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1574 error("accept from auth socket: %.100s",
1576 if (errno == EMFILE || errno == ENFILE)
1577 c->notbefore = monotime() + 1;
1580 nc = channel_new("accepted auth socket",
1581 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1582 c->local_window_max, c->local_maxpacket,
1583 0, "accepted auth socket", 1);
1585 packet_start(SSH2_MSG_CHANNEL_OPEN);
1586 packet_put_cstring("auth-agent@openssh.com");
1587 packet_put_int(nc->self);
1588 packet_put_int(c->local_window_max);
1589 packet_put_int(c->local_maxpacket);
1591 packet_start(SSH_SMSG_AGENT_OPEN);
1592 packet_put_int(nc->self);
1600 channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1603 socklen_t sz = sizeof(err);
1605 if (FD_ISSET(c->sock, writeset)) {
1606 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1608 error("getsockopt SO_ERROR failed");
1611 debug("channel %d: connected to %s port %d",
1612 c->self, c->connect_ctx.host, c->connect_ctx.port);
1613 channel_connect_ctx_free(&c->connect_ctx);
1614 c->type = SSH_CHANNEL_OPEN;
1616 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1617 packet_put_int(c->remote_id);
1618 packet_put_int(c->self);
1619 packet_put_int(c->local_window);
1620 packet_put_int(c->local_maxpacket);
1622 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1623 packet_put_int(c->remote_id);
1624 packet_put_int(c->self);
1627 debug("channel %d: connection failed: %s",
1628 c->self, strerror(err));
1629 /* Try next address, if any */
1630 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1632 c->sock = c->rfd = c->wfd = sock;
1633 channel_max_fd = channel_find_maxfd();
1636 /* Exhausted all addresses */
1637 error("connect_to %.100s port %d: failed.",
1638 c->connect_ctx.host, c->connect_ctx.port);
1639 channel_connect_ctx_free(&c->connect_ctx);
1641 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1642 packet_put_int(c->remote_id);
1643 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1644 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1645 packet_put_cstring(strerror(err));
1646 packet_put_cstring("");
1649 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1650 packet_put_int(c->remote_id);
1660 channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1662 char buf[CHAN_RBUF];
1665 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1666 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1668 len = read(c->rfd, buf, sizeof(buf));
1669 if (len < 0 && (errno == EINTR ||
1670 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1672 #ifndef PTY_ZEROREAD
1675 if ((!c->isatty && len <= 0) ||
1676 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1678 debug2("channel %d: read<=0 rfd %d len %d",
1679 c->self, c->rfd, len);
1680 if (c->type != SSH_CHANNEL_OPEN) {
1681 debug2("channel %d: not open", c->self);
1684 } else if (compat13) {
1685 buffer_clear(&c->output);
1686 c->type = SSH_CHANNEL_INPUT_DRAINING;
1687 debug2("channel %d: input draining.", c->self);
1689 chan_read_failed(c);
1693 if (c->input_filter != NULL) {
1694 if (c->input_filter(c, buf, len) == -1) {
1695 debug2("channel %d: filter stops", c->self);
1696 chan_read_failed(c);
1698 } else if (c->datagram) {
1699 buffer_put_string(&c->input, buf, len);
1701 buffer_append(&c->input, buf, len);
1709 channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1712 u_char *data = NULL, *buf;
1713 u_int dlen, olen = 0;
1716 /* Send buffered output data to the socket. */
1718 FD_ISSET(c->wfd, writeset) &&
1719 buffer_len(&c->output) > 0) {
1720 olen = buffer_len(&c->output);
1721 if (c->output_filter != NULL) {
1722 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1723 debug2("channel %d: filter stops", c->self);
1724 if (c->type != SSH_CHANNEL_OPEN)
1727 chan_write_failed(c);
1730 } else if (c->datagram) {
1731 buf = data = buffer_get_string(&c->output, &dlen);
1733 buf = data = buffer_ptr(&c->output);
1734 dlen = buffer_len(&c->output);
1738 /* ignore truncated writes, datagrams might get lost */
1739 len = write(c->wfd, buf, dlen);
1741 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1742 errno == EWOULDBLOCK))
1745 if (c->type != SSH_CHANNEL_OPEN)
1748 chan_write_failed(c);
1754 /* XXX: Later AIX versions can't push as much data to tty */
1755 if (compat20 && c->wfd_isatty)
1756 dlen = MIN(dlen, 8*1024);
1759 len = write(c->wfd, buf, dlen);
1761 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1764 if (c->type != SSH_CHANNEL_OPEN) {
1765 debug2("channel %d: not open", c->self);
1768 } else if (compat13) {
1769 buffer_clear(&c->output);
1770 debug2("channel %d: input draining.", c->self);
1771 c->type = SSH_CHANNEL_INPUT_DRAINING;
1773 chan_write_failed(c);
1777 #ifndef BROKEN_TCGETATTR_ICANON
1778 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1779 if (tcgetattr(c->wfd, &tio) == 0 &&
1780 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1782 * Simulate echo to reduce the impact of
1783 * traffic analysis. We need to match the
1784 * size of a SSH2_MSG_CHANNEL_DATA message
1785 * (4 byte channel id + buf)
1787 packet_send_ignore(4 + len);
1792 buffer_consume(&c->output, len);
1795 if (compat20 && olen > 0)
1796 c->local_consumed += olen - buffer_len(&c->output);
1801 channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1803 char buf[CHAN_RBUF];
1806 /** XXX handle drain efd, too */
1808 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1809 FD_ISSET(c->efd, writeset) &&
1810 buffer_len(&c->extended) > 0) {
1811 len = write(c->efd, buffer_ptr(&c->extended),
1812 buffer_len(&c->extended));
1813 debug2("channel %d: written %d to efd %d",
1814 c->self, len, c->efd);
1815 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1816 errno == EWOULDBLOCK))
1819 debug2("channel %d: closing write-efd %d",
1821 channel_close_fd(&c->efd);
1823 buffer_consume(&c->extended, len);
1824 c->local_consumed += len;
1826 } else if (c->efd != -1 &&
1827 (c->extended_usage == CHAN_EXTENDED_READ ||
1828 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1829 (c->detach_close || FD_ISSET(c->efd, readset))) {
1830 len = read(c->efd, buf, sizeof(buf));
1831 debug2("channel %d: read %d from efd %d",
1832 c->self, len, c->efd);
1833 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1834 errno == EWOULDBLOCK) && !c->detach_close)))
1837 debug2("channel %d: closing read-efd %d",
1839 channel_close_fd(&c->efd);
1841 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1842 debug3("channel %d: discard efd",
1845 buffer_append(&c->extended, buf, len);
1853 channel_check_window(Channel *c)
1855 if (c->type == SSH_CHANNEL_OPEN &&
1856 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1857 ((c->local_window_max - c->local_window >
1858 c->local_maxpacket*3) ||
1859 c->local_window < c->local_window_max/2) &&
1860 c->local_consumed > 0) {
1863 /* Adjust max window size if we are in a dynamic environment. */
1864 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1866 * Grow the window somewhat aggressively to maintain
1869 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1870 c->local_window_max += addition;
1872 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1873 packet_put_int(c->remote_id);
1874 packet_put_int(c->local_consumed + addition);
1876 debug2("channel %d: window %d sent adjust %d",
1877 c->self, c->local_window,
1879 c->local_window += c->local_consumed + addition;
1880 c->local_consumed = 0;
1886 channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1888 channel_handle_rfd(c, readset, writeset);
1889 channel_handle_wfd(c, readset, writeset);
1892 channel_handle_efd(c, readset, writeset);
1893 channel_check_window(c);
1897 read_mux(Channel *c, u_int need)
1899 char buf[CHAN_RBUF];
1903 if (buffer_len(&c->input) < need) {
1904 rlen = need - buffer_len(&c->input);
1905 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1907 if (errno != EINTR && errno != EAGAIN) {
1908 debug2("channel %d: ctl read<=0 rfd %d len %d",
1909 c->self, c->rfd, len);
1910 chan_read_failed(c);
1914 buffer_append(&c->input, buf, len);
1916 return buffer_len(&c->input);
1920 channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1926 fatal("%s: entered with !compat20", __func__);
1928 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1929 (c->istate == CHAN_INPUT_OPEN ||
1930 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1932 * Don't not read past the precise end of packets to
1933 * avoid disrupting fd passing.
1935 if (read_mux(c, 4) < 4) /* read header */
1937 need = get_u32(buffer_ptr(&c->input));
1938 #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1939 if (need > CHANNEL_MUX_MAX_PACKET) {
1940 debug2("channel %d: packet too big %u > %u",
1941 c->self, CHANNEL_MUX_MAX_PACKET, need);
1942 chan_rcvd_oclose(c);
1945 if (read_mux(c, need + 4) < need + 4) /* read body */
1947 if (c->mux_rcb(c) != 0) {
1948 debug("channel %d: mux_rcb failed", c->self);
1954 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1955 buffer_len(&c->output) > 0) {
1956 len = write(c->wfd, buffer_ptr(&c->output),
1957 buffer_len(&c->output));
1958 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1964 buffer_consume(&c->output, len);
1969 channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1972 struct sockaddr_storage addr;
1978 if (!FD_ISSET(c->sock, readset))
1981 debug("multiplexing control connection");
1984 * Accept connection on control socket
1986 memset(&addr, 0, sizeof(addr));
1987 addrlen = sizeof(addr);
1988 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1990 error("%s accept: %s", __func__, strerror(errno));
1991 if (errno == EMFILE || errno == ENFILE)
1992 c->notbefore = monotime() + 1;
1996 if (getpeereid(newsock, &euid, &egid) < 0) {
1997 error("%s getpeereid failed: %s", __func__,
2002 if ((euid != 0) && (getuid() != euid)) {
2003 error("multiplex uid mismatch: peer euid %u != uid %u",
2004 (u_int)euid, (u_int)getuid());
2008 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
2009 newsock, newsock, -1, c->local_window_max,
2010 c->local_maxpacket, 0, "mux-control", 1);
2011 nc->mux_rcb = c->mux_rcb;
2012 debug3("%s: new mux channel %d fd %d", __func__,
2013 nc->self, nc->sock);
2014 /* establish state */
2016 /* mux state transitions must not elicit protocol messages */
2017 nc->flags |= CHAN_LOCAL;
2022 channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
2026 /* Send buffered output data to the socket. */
2027 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2028 len = write(c->sock, buffer_ptr(&c->output),
2029 buffer_len(&c->output));
2031 buffer_clear(&c->output);
2033 buffer_consume(&c->output, len);
2038 channel_handler_init_20(void)
2040 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2041 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2042 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2043 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2044 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2045 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2046 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2047 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2048 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2049 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2051 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2052 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2053 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2054 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2055 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2056 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2057 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2058 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2059 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2063 channel_handler_init_13(void)
2065 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2066 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2067 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2068 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2069 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2070 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2071 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2072 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2073 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2075 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2076 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2077 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2078 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2079 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2080 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2081 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2085 channel_handler_init_15(void)
2087 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2088 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2089 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2090 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2091 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2092 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2093 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2095 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2096 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2097 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2098 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2099 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2100 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2104 channel_handler_init(void)
2108 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2109 channel_pre[i] = NULL;
2110 channel_post[i] = NULL;
2113 channel_handler_init_20();
2115 channel_handler_init_13();
2117 channel_handler_init_15();
2120 /* gc dead channels */
2122 channel_garbage_collect(Channel *c)
2126 if (c->detach_user != NULL) {
2127 if (!chan_is_dead(c, c->detach_close))
2129 debug2("channel %d: gc: notify user", c->self);
2130 c->detach_user(c->self, NULL);
2131 /* if we still have a callback */
2132 if (c->detach_user != NULL)
2134 debug2("channel %d: gc: user detached", c->self);
2136 if (!chan_is_dead(c, 1))
2138 debug2("channel %d: garbage collecting", c->self);
2143 channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2144 time_t *unpause_secs)
2146 static int did_init = 0;
2152 channel_handler_init();
2156 if (unpause_secs != NULL)
2158 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2163 if (ftab == channel_pre)
2168 if (ftab[c->type] != NULL) {
2170 * Run handlers that are not paused.
2172 if (c->notbefore <= now)
2173 (*ftab[c->type])(c, readset, writeset);
2174 else if (unpause_secs != NULL) {
2176 * Collect the time that the earliest
2177 * channel comes off pause.
2179 debug3("%s: chan %d: skip for %d more seconds",
2181 (int)(c->notbefore - now));
2182 if (*unpause_secs == 0 ||
2183 (c->notbefore - now) < *unpause_secs)
2184 *unpause_secs = c->notbefore - now;
2187 channel_garbage_collect(c);
2189 if (unpause_secs != NULL && *unpause_secs != 0)
2190 debug3("%s: first channel unpauses in %d seconds",
2191 __func__, (int)*unpause_secs);
2195 * Allocate/update select bitmasks and add any bits relevant to channels in
2199 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2200 u_int *nallocp, time_t *minwait_secs, int rekeying)
2202 u_int n, sz, nfdset;
2204 n = MAX(*maxfdp, channel_max_fd);
2206 nfdset = howmany(n+1, NFDBITS);
2207 /* Explicitly test here, because xrealloc isn't always called */
2208 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2209 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2210 sz = nfdset * sizeof(fd_mask);
2212 /* perhaps check sz < nalloc/2 and shrink? */
2213 if (*readsetp == NULL || sz > *nallocp) {
2214 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2215 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2219 memset(*readsetp, 0, sz);
2220 memset(*writesetp, 0, sz);
2223 channel_handler(channel_pre, *readsetp, *writesetp,
2228 * After select, perform any appropriate operations for channels which have
2232 channel_after_select(fd_set *readset, fd_set *writeset)
2234 channel_handler(channel_post, readset, writeset, NULL);
2238 /* If there is data to send to the connection, enqueue some of it now. */
2240 channel_output_poll(void)
2245 for (i = 0; i < channels_alloc; i++) {
2251 * We are only interested in channels that can have buffered
2255 if (c->type != SSH_CHANNEL_OPEN &&
2256 c->type != SSH_CHANNEL_INPUT_DRAINING)
2259 if (c->type != SSH_CHANNEL_OPEN)
2263 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2264 /* XXX is this true? */
2265 debug3("channel %d: will not send data after close", c->self);
2269 /* Get the amount of buffered data for this channel. */
2270 if ((c->istate == CHAN_INPUT_OPEN ||
2271 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2272 (len = buffer_len(&c->input)) > 0) {
2278 data = buffer_get_string(&c->input,
2280 if (dlen > c->remote_window ||
2281 dlen > c->remote_maxpacket) {
2282 debug("channel %d: datagram "
2283 "too big for channel",
2288 packet_start(SSH2_MSG_CHANNEL_DATA);
2289 packet_put_int(c->remote_id);
2290 packet_put_string(data, dlen);
2292 c->remote_window -= dlen + 4;
2298 * Send some data for the other side over the secure
2302 if (len > c->remote_window)
2303 len = c->remote_window;
2304 if (len > c->remote_maxpacket)
2305 len = c->remote_maxpacket;
2307 if (packet_is_interactive()) {
2311 /* Keep the packets at reasonable size. */
2312 if (len > packet_get_maxsize()/2)
2313 len = packet_get_maxsize()/2;
2317 packet_start(compat20 ?
2318 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2319 packet_put_int(c->remote_id);
2320 packet_put_string(buffer_ptr(&c->input), len);
2322 buffer_consume(&c->input, len);
2323 c->remote_window -= len;
2325 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2327 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2329 * input-buffer is empty and read-socket shutdown:
2330 * tell peer, that we will not send more data: send IEOF.
2331 * hack for extended data: delay EOF if EFD still in use.
2333 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2334 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2335 c->self, c->efd, buffer_len(&c->extended));
2339 /* Send extended data, i.e. stderr */
2341 !(c->flags & CHAN_EOF_SENT) &&
2342 c->remote_window > 0 &&
2343 (len = buffer_len(&c->extended)) > 0 &&
2344 c->extended_usage == CHAN_EXTENDED_READ) {
2345 debug2("channel %d: rwin %u elen %u euse %d",
2346 c->self, c->remote_window, buffer_len(&c->extended),
2348 if (len > c->remote_window)
2349 len = c->remote_window;
2350 if (len > c->remote_maxpacket)
2351 len = c->remote_maxpacket;
2352 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2353 packet_put_int(c->remote_id);
2354 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2355 packet_put_string(buffer_ptr(&c->extended), len);
2357 buffer_consume(&c->extended, len);
2358 c->remote_window -= len;
2359 debug2("channel %d: sent ext data %d", c->self, len);
2365 /* -- protocol input */
2369 channel_input_data(int type, u_int32_t seq, void *ctxt)
2373 u_int data_len, win_len;
2376 /* Get the channel number and verify it. */
2377 id = packet_get_int();
2378 c = channel_lookup(id);
2380 packet_disconnect("Received data for nonexistent channel %d.", id);
2382 /* Ignore any data for non-open channels (might happen on close) */
2383 if (c->type != SSH_CHANNEL_OPEN &&
2384 c->type != SSH_CHANNEL_X11_OPEN)
2388 data = packet_get_string_ptr(&data_len);
2391 win_len += 4; /* string length header */
2394 * Ignore data for protocol > 1.3 if output end is no longer open.
2395 * For protocol 2 the sending side is reducing its window as it sends
2396 * data, so we must 'fake' consumption of the data in order to ensure
2397 * that window updates are sent back. Otherwise the connection might
2400 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2402 c->local_window -= win_len;
2403 c->local_consumed += win_len;
2409 if (win_len > c->local_maxpacket) {
2410 logit("channel %d: rcvd big packet %d, maxpack %d",
2411 c->self, win_len, c->local_maxpacket);
2413 if (win_len > c->local_window) {
2414 logit("channel %d: rcvd too much data %d, win %d",
2415 c->self, win_len, c->local_window);
2418 c->local_window -= win_len;
2421 buffer_put_string(&c->output, data, data_len);
2423 buffer_append(&c->output, data, data_len);
2429 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2433 u_int data_len, tcode;
2436 /* Get the channel number and verify it. */
2437 id = packet_get_int();
2438 c = channel_lookup(id);
2441 packet_disconnect("Received extended_data for bad channel %d.", id);
2442 if (c->type != SSH_CHANNEL_OPEN) {
2443 logit("channel %d: ext data for non open", id);
2446 if (c->flags & CHAN_EOF_RCVD) {
2447 if (datafellows & SSH_BUG_EXTEOF)
2448 debug("channel %d: accepting ext data after eof", id);
2450 packet_disconnect("Received extended_data after EOF "
2451 "on channel %d.", id);
2453 tcode = packet_get_int();
2455 c->extended_usage != CHAN_EXTENDED_WRITE ||
2456 tcode != SSH2_EXTENDED_DATA_STDERR) {
2457 logit("channel %d: bad ext data", c->self);
2460 data = packet_get_string(&data_len);
2462 if (data_len > c->local_window) {
2463 logit("channel %d: rcvd too much extended_data %d, win %d",
2464 c->self, data_len, c->local_window);
2468 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2469 c->local_window -= data_len;
2470 buffer_append(&c->extended, data, data_len);
2476 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2481 id = packet_get_int();
2483 c = channel_lookup(id);
2485 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2488 /* XXX force input close */
2489 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2490 debug("channel %d: FORCE input drain", c->self);
2491 c->istate = CHAN_INPUT_WAIT_DRAIN;
2492 if (buffer_len(&c->input) == 0)
2500 channel_input_close(int type, u_int32_t seq, void *ctxt)
2505 id = packet_get_int();
2507 c = channel_lookup(id);
2509 packet_disconnect("Received close for nonexistent channel %d.", id);
2512 * Send a confirmation that we have closed the channel and no more
2513 * data is coming for it.
2515 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2516 packet_put_int(c->remote_id);
2520 * If the channel is in closed state, we have sent a close request,
2521 * and the other side will eventually respond with a confirmation.
2522 * Thus, we cannot free the channel here, because then there would be
2523 * no-one to receive the confirmation. The channel gets freed when
2524 * the confirmation arrives.
2526 if (c->type != SSH_CHANNEL_CLOSED) {
2528 * Not a closed channel - mark it as draining, which will
2529 * cause it to be freed later.
2531 buffer_clear(&c->input);
2532 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2536 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2539 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2541 int id = packet_get_int();
2542 Channel *c = channel_lookup(id);
2546 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2547 chan_rcvd_oclose(c);
2552 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2554 int id = packet_get_int();
2555 Channel *c = channel_lookup(id);
2559 packet_disconnect("Received close confirmation for "
2560 "out-of-range channel %d.", id);
2561 if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
2562 packet_disconnect("Received close confirmation for "
2563 "non-closed channel %d (type %d).", id, c->type);
2569 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2574 id = packet_get_int();
2575 c = channel_lookup(id);
2577 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2578 packet_disconnect("Received open confirmation for "
2579 "non-opening channel %d.", id);
2580 remote_id = packet_get_int();
2581 /* Record the remote channel number and mark that the channel is now open. */
2582 c->remote_id = remote_id;
2583 c->type = SSH_CHANNEL_OPEN;
2586 c->remote_window = packet_get_int();
2587 c->remote_maxpacket = packet_get_int();
2588 if (c->open_confirm) {
2589 debug2("callback start");
2590 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2591 debug2("callback done");
2593 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2594 c->remote_window, c->remote_maxpacket);
2600 reason2txt(int reason)
2603 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2604 return "administratively prohibited";
2605 case SSH2_OPEN_CONNECT_FAILED:
2606 return "connect failed";
2607 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2608 return "unknown channel type";
2609 case SSH2_OPEN_RESOURCE_SHORTAGE:
2610 return "resource shortage";
2612 return "unknown reason";
2617 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2620 char *msg = NULL, *lang = NULL;
2623 id = packet_get_int();
2624 c = channel_lookup(id);
2626 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2627 packet_disconnect("Received open failure for "
2628 "non-opening channel %d.", id);
2630 reason = packet_get_int();
2631 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2632 msg = packet_get_string(NULL);
2633 lang = packet_get_string(NULL);
2635 logit("channel %d: open failed: %s%s%s", id,
2636 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2639 if (c->open_confirm) {
2640 debug2("callback start");
2641 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2642 debug2("callback done");
2646 /* Schedule the channel for cleanup/deletion. */
2652 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2661 /* Get the channel number and verify it. */
2662 id = packet_get_int();
2663 c = channel_lookup(id);
2666 logit("Received window adjust for non-open channel %d.", id);
2669 adjust = packet_get_int();
2671 debug2("channel %d: rcvd adjust %u", id, adjust);
2672 c->remote_window += adjust;
2677 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2681 char *host, *originator_string;
2684 remote_id = packet_get_int();
2685 host = packet_get_string(NULL);
2686 host_port = packet_get_int();
2688 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2689 originator_string = packet_get_string(NULL);
2691 originator_string = xstrdup("unknown (remote did not supply name)");
2694 c = channel_connect_to(host, host_port,
2695 "connected socket", originator_string);
2696 free(originator_string);
2699 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2700 packet_put_int(remote_id);
2703 c->remote_id = remote_id;
2708 channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2711 struct channel_confirm *cc;
2714 /* Reset keepalive timeout */
2715 packet_set_alive_timeouts(0);
2717 id = packet_get_int();
2720 debug2("channel_input_status_confirm: type %d id %d", type, id);
2722 if ((c = channel_lookup(id)) == NULL) {
2723 logit("channel_input_status_confirm: %d: unknown", id);
2727 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2729 cc->cb(type, c, cc->ctx);
2730 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2731 explicit_bzero(cc, sizeof(*cc));
2735 /* -- tcp forwarding */
2738 channel_set_af(int af)
2744 channel_set_hpn(int disabled, u_int buf_size)
2746 hpn_disabled = disabled;
2747 buffer_size = buf_size;
2748 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2749 hpn_disabled, buffer_size);
2753 * Determine whether or not a port forward listens to loopback, the
2754 * specified address or wildcard. On the client, a specified bind
2755 * address will always override gateway_ports. On the server, a
2756 * gateway_ports of 1 (``yes'') will override the client's specification
2757 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2758 * will bind to whatever address the client asked for.
2760 * Special-case listen_addrs are:
2762 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2763 * "" (empty string), "*" -> wildcard v4/v6
2764 * "localhost" -> loopback v4/v6
2767 channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2768 int is_client, int gateway_ports)
2770 const char *addr = NULL;
2773 if (listen_addr == NULL) {
2774 /* No address specified: default to gateway_ports setting */
2777 } else if (gateway_ports || is_client) {
2778 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2779 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2780 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2781 (!is_client && gateway_ports == 1)) {
2784 * Notify client if they requested a specific listen
2785 * address and it was overridden.
2787 if (*listen_addr != '\0' &&
2788 strcmp(listen_addr, "0.0.0.0") != 0 &&
2789 strcmp(listen_addr, "*") != 0) {
2790 packet_send_debug("Forwarding listen address "
2791 "\"%s\" overridden by server "
2792 "GatewayPorts", listen_addr);
2795 else if (strcmp(listen_addr, "localhost") != 0)
2798 if (wildcardp != NULL)
2799 *wildcardp = wildcard;
2804 channel_setup_fwd_listener(int type, const char *listen_addr,
2805 u_short listen_port, int *allocated_listen_port,
2806 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2809 int sock, r, success = 0, wildcard = 0, is_client;
2810 struct addrinfo hints, *ai, *aitop;
2811 const char *host, *addr;
2812 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2815 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2816 listen_addr : host_to_connect;
2817 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2820 error("No forward host name.");
2823 if (strlen(host) >= NI_MAXHOST) {
2824 error("Forward host name too long.");
2828 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2829 addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2830 is_client, gateway_ports);
2831 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2832 type, wildcard, (addr == NULL) ? "NULL" : addr);
2835 * getaddrinfo returns a loopback address if the hostname is
2836 * set to NULL and hints.ai_flags is not AI_PASSIVE
2838 memset(&hints, 0, sizeof(hints));
2839 hints.ai_family = IPv4or6;
2840 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2841 hints.ai_socktype = SOCK_STREAM;
2842 snprintf(strport, sizeof strport, "%d", listen_port);
2843 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2845 /* This really shouldn't happen */
2846 packet_disconnect("getaddrinfo: fatal error: %s",
2847 ssh_gai_strerror(r));
2849 error("channel_setup_fwd_listener: "
2850 "getaddrinfo(%.64s): %s", addr,
2851 ssh_gai_strerror(r));
2855 if (allocated_listen_port != NULL)
2856 *allocated_listen_port = 0;
2857 for (ai = aitop; ai; ai = ai->ai_next) {
2858 switch (ai->ai_family) {
2860 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2864 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2871 * If allocating a port for -R forwards, then use the
2872 * same port for all address families.
2874 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2875 allocated_listen_port != NULL && *allocated_listen_port > 0)
2876 *lport_p = htons(*allocated_listen_port);
2878 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2879 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2880 error("channel_setup_fwd_listener: getnameinfo failed");
2883 /* Create a port to listen for the host. */
2884 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2886 /* this is no error since kernel may not support ipv6 */
2887 verbose("socket: %.100s", strerror(errno));
2891 channel_set_reuseaddr(sock);
2892 if (ai->ai_family == AF_INET6)
2893 sock_set_v6only(sock);
2895 debug("Local forwarding listening on %s port %s.",
2898 /* Bind the socket to the address. */
2899 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2900 /* address can be in use ipv6 address is already bound */
2902 error("bind: %.100s", strerror(errno));
2904 verbose("bind: %.100s", strerror(errno));
2909 /* Start listening for connections on the socket. */
2910 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2911 error("listen: %.100s", strerror(errno));
2917 * listen_port == 0 requests a dynamically allocated port -
2918 * record what we got.
2920 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2921 allocated_listen_port != NULL &&
2922 *allocated_listen_port == 0) {
2923 *allocated_listen_port = get_sock_port(sock, 1);
2924 debug("Allocated listen port %d",
2925 *allocated_listen_port);
2929 * Allocate a channel number for the socket. Explicitly test
2930 * for hpn disabled option. If true use smaller window size.
2933 c = channel_new("port listener", type, sock, sock, -1,
2934 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2935 0, "port listener", 1);
2937 c = channel_new("port listener", type, sock, sock, -1,
2938 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2939 0, "port listener", 1);
2940 c->path = xstrdup(host);
2941 c->host_port = port_to_connect;
2942 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2943 if (listen_port == 0 && allocated_listen_port != NULL &&
2944 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2945 c->listening_port = *allocated_listen_port;
2947 c->listening_port = listen_port;
2951 error("channel_setup_fwd_listener: cannot listen to port: %d",
2953 freeaddrinfo(aitop);
2958 channel_cancel_rport_listener(const char *host, u_short port)
2963 for (i = 0; i < channels_alloc; i++) {
2964 Channel *c = channels[i];
2965 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2967 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2968 debug2("%s: close channel %d", __func__, i);
2978 channel_cancel_lport_listener(const char *lhost, u_short lport,
2979 int cport, int gateway_ports)
2983 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
2985 for (i = 0; i < channels_alloc; i++) {
2986 Channel *c = channels[i];
2987 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2989 if (c->listening_port != lport)
2991 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2992 /* skip dynamic forwardings */
2993 if (c->host_port == 0)
2996 if (c->host_port != cport)
2999 if ((c->listening_addr == NULL && addr != NULL) ||
3000 (c->listening_addr != NULL && addr == NULL))
3002 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
3003 debug2("%s: close channel %d", __func__, i);
3012 /* protocol local port fwd, used by ssh (and sshd in v1) */
3014 channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
3015 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
3017 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
3018 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
3022 /* protocol v2 remote port fwd, used by sshd */
3024 channel_setup_remote_fwd_listener(const char *listen_address,
3025 u_short listen_port, int *allocated_listen_port, int gateway_ports)
3027 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
3028 listen_address, listen_port, allocated_listen_port,
3029 NULL, 0, gateway_ports);
3033 * Translate the requested rfwd listen host to something usable for
3037 channel_rfwd_bind_host(const char *listen_host)
3039 if (listen_host == NULL) {
3040 if (datafellows & SSH_BUG_RFWD_ADDR)
3044 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3045 if (datafellows & SSH_BUG_RFWD_ADDR)
3054 * Initiate forwarding of connections to port "port" on remote host through
3055 * the secure channel to host:port from local side.
3056 * Returns handle (index) for updating the dynamic listen port with
3057 * channel_update_permitted_opens().
3060 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
3061 const char *host_to_connect, u_short port_to_connect)
3063 int type, success = 0, idx = -1;
3065 /* Send the forward request to the remote side. */
3067 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3068 packet_put_cstring("tcpip-forward");
3069 packet_put_char(1); /* boolean: want reply */
3070 packet_put_cstring(channel_rfwd_bind_host(listen_host));
3071 packet_put_int(listen_port);
3073 packet_write_wait();
3074 /* Assume that server accepts the request */
3077 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
3078 packet_put_int(listen_port);
3079 packet_put_cstring(host_to_connect);
3080 packet_put_int(port_to_connect);
3082 packet_write_wait();
3084 /* Wait for response from the remote side. */
3085 type = packet_read();
3087 case SSH_SMSG_SUCCESS:
3090 case SSH_SMSG_FAILURE:
3093 /* Unknown packet */
3094 packet_disconnect("Protocol error for port forward request:"
3095 "received packet type %d.", type);
3099 /* Record that connection to this host/port is permitted. */
3100 permitted_opens = xrealloc(permitted_opens,
3101 num_permitted_opens + 1, sizeof(*permitted_opens));
3102 idx = num_permitted_opens++;
3103 permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
3104 permitted_opens[idx].port_to_connect = port_to_connect;
3105 permitted_opens[idx].listen_port = listen_port;
3111 * Request cancellation of remote forwarding of connection host:port from
3115 channel_request_rforward_cancel(const char *host, u_short port)
3122 for (i = 0; i < num_permitted_opens; i++) {
3123 if (permitted_opens[i].host_to_connect != NULL &&
3124 permitted_opens[i].listen_port == port)
3127 if (i >= num_permitted_opens) {
3128 debug("%s: requested forward not found", __func__);
3131 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3132 packet_put_cstring("cancel-tcpip-forward");
3134 packet_put_cstring(channel_rfwd_bind_host(host));
3135 packet_put_int(port);
3138 permitted_opens[i].listen_port = 0;
3139 permitted_opens[i].port_to_connect = 0;
3140 free(permitted_opens[i].host_to_connect);
3141 permitted_opens[i].host_to_connect = NULL;
3147 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3148 * listening for the port, and sends back a success reply (or disconnect
3149 * message if there was an error).
3152 channel_input_port_forward_request(int is_root, int gateway_ports)
3154 u_short port, host_port;
3158 /* Get arguments from the packet. */
3159 port = packet_get_int();
3160 hostname = packet_get_string(NULL);
3161 host_port = packet_get_int();
3165 * Check that an unprivileged user is not trying to forward a
3168 if (port < IPPORT_RESERVED && !is_root)
3170 "Requested forwarding of port %d but user is not root.",
3173 packet_disconnect("Dynamic forwarding denied.");
3176 /* Initiate forwarding */
3177 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3178 host_port, gateway_ports);
3180 /* Free the argument string. */
3183 return (success ? 0 : -1);
3187 * Permits opening to any host/port if permitted_opens[] is empty. This is
3188 * usually called by the server, because the user could connect to any port
3189 * anyway, and the server has no way to know but to trust the client anyway.
3192 channel_permit_all_opens(void)
3194 if (num_permitted_opens == 0)
3195 all_opens_permitted = 1;
3199 channel_add_permitted_opens(char *host, int port)
3201 debug("allow port forwarding to host %s port %d", host, port);
3203 permitted_opens = xrealloc(permitted_opens,
3204 num_permitted_opens + 1, sizeof(*permitted_opens));
3205 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3206 permitted_opens[num_permitted_opens].port_to_connect = port;
3207 num_permitted_opens++;
3209 all_opens_permitted = 0;
3213 * Update the listen port for a dynamic remote forward, after
3214 * the actual 'newport' has been allocated. If 'newport' < 0 is
3215 * passed then they entry will be invalidated.
3218 channel_update_permitted_opens(int idx, int newport)
3220 if (idx < 0 || idx >= num_permitted_opens) {
3221 debug("channel_update_permitted_opens: index out of range:"
3222 " %d num_permitted_opens %d", idx, num_permitted_opens);
3225 debug("%s allowed port %d for forwarding to host %s port %d",
3226 newport > 0 ? "Updating" : "Removing",
3228 permitted_opens[idx].host_to_connect,
3229 permitted_opens[idx].port_to_connect);
3231 permitted_opens[idx].listen_port =
3232 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3234 permitted_opens[idx].listen_port = 0;
3235 permitted_opens[idx].port_to_connect = 0;
3236 free(permitted_opens[idx].host_to_connect);
3237 permitted_opens[idx].host_to_connect = NULL;
3242 channel_add_adm_permitted_opens(char *host, int port)
3244 debug("config allows port forwarding to host %s port %d", host, port);
3246 permitted_adm_opens = xrealloc(permitted_adm_opens,
3247 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3248 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3250 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3251 return ++num_adm_permitted_opens;
3255 channel_disable_adm_local_opens(void)
3257 channel_clear_adm_permitted_opens();
3258 permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3259 permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3260 num_adm_permitted_opens = 1;
3264 channel_clear_permitted_opens(void)
3268 for (i = 0; i < num_permitted_opens; i++)
3269 free(permitted_opens[i].host_to_connect);
3270 free(permitted_opens);
3271 permitted_opens = NULL;
3272 num_permitted_opens = 0;
3276 channel_clear_adm_permitted_opens(void)
3280 for (i = 0; i < num_adm_permitted_opens; i++)
3281 free(permitted_adm_opens[i].host_to_connect);
3282 free(permitted_adm_opens);
3283 permitted_adm_opens = NULL;
3284 num_adm_permitted_opens = 0;
3288 channel_print_adm_permitted_opens(void)
3292 printf("permitopen");
3293 if (num_adm_permitted_opens == 0) {
3297 for (i = 0; i < num_adm_permitted_opens; i++)
3298 if (permitted_adm_opens[i].host_to_connect == NULL)
3301 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3302 permitted_adm_opens[i].port_to_connect);
3306 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3308 permitopen_port(const char *p)
3312 if (strcmp(p, "*") == 0)
3313 return FWD_PERMIT_ANY_PORT;
3314 if ((port = a2port(p)) > 0)
3320 port_match(u_short allowedport, u_short requestedport)
3322 if (allowedport == FWD_PERMIT_ANY_PORT ||
3323 allowedport == requestedport)
3328 /* Try to start non-blocking connect to next host in cctx list */
3330 connect_next(struct channel_connect *cctx)
3332 int sock, saved_errno;
3333 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3335 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3336 if (cctx->ai->ai_family != AF_INET &&
3337 cctx->ai->ai_family != AF_INET6)
3339 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3340 ntop, sizeof(ntop), strport, sizeof(strport),
3341 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3342 error("connect_next: getnameinfo failed");
3345 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3346 cctx->ai->ai_protocol)) == -1) {
3347 if (cctx->ai->ai_next == NULL)
3348 error("socket: %.100s", strerror(errno));
3350 verbose("socket: %.100s", strerror(errno));
3353 if (set_nonblock(sock) == -1)
3354 fatal("%s: set_nonblock(%d)", __func__, sock);
3355 if (connect(sock, cctx->ai->ai_addr,
3356 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3357 debug("connect_next: host %.100s ([%.100s]:%s): "
3358 "%.100s", cctx->host, ntop, strport,
3360 saved_errno = errno;
3362 errno = saved_errno;
3363 continue; /* fail -- try next */
3365 debug("connect_next: host %.100s ([%.100s]:%s) "
3366 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3367 cctx->ai = cctx->ai->ai_next;
3375 channel_connect_ctx_free(struct channel_connect *cctx)
3379 freeaddrinfo(cctx->aitop);
3380 memset(cctx, 0, sizeof(*cctx));
3383 /* Return CONNECTING channel to remote host, port */
3385 connect_to(const char *host, u_short port, char *ctype, char *rname)
3387 struct addrinfo hints;
3390 char strport[NI_MAXSERV];
3391 struct channel_connect cctx;
3394 memset(&cctx, 0, sizeof(cctx));
3395 memset(&hints, 0, sizeof(hints));
3396 hints.ai_family = IPv4or6;
3397 hints.ai_socktype = SOCK_STREAM;
3398 snprintf(strport, sizeof strport, "%d", port);
3399 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3400 error("connect_to %.100s: unknown host (%s)", host,
3401 ssh_gai_strerror(gaierr));
3405 cctx.host = xstrdup(host);
3407 cctx.ai = cctx.aitop;
3409 if ((sock = connect_next(&cctx)) == -1) {
3410 error("connect to %.100s port %d failed: %s",
3411 host, port, strerror(errno));
3412 channel_connect_ctx_free(&cctx);
3415 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3416 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3417 c->connect_ctx = cctx;
3422 channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3426 for (i = 0; i < num_permitted_opens; i++) {
3427 if (permitted_opens[i].host_to_connect != NULL &&
3428 port_match(permitted_opens[i].listen_port, listen_port)) {
3430 permitted_opens[i].host_to_connect,
3431 permitted_opens[i].port_to_connect, ctype, rname);
3434 error("WARNING: Server requests forwarding for unknown listen_port %d",
3439 /* Check if connecting to that port is permitted and connect. */
3441 channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3443 int i, permit, permit_adm = 1;
3445 permit = all_opens_permitted;
3447 for (i = 0; i < num_permitted_opens; i++)
3448 if (permitted_opens[i].host_to_connect != NULL &&
3449 port_match(permitted_opens[i].port_to_connect, port) &&
3450 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3454 if (num_adm_permitted_opens > 0) {
3456 for (i = 0; i < num_adm_permitted_opens; i++)
3457 if (permitted_adm_opens[i].host_to_connect != NULL &&
3458 port_match(permitted_adm_opens[i].port_to_connect, port) &&
3459 strcmp(permitted_adm_opens[i].host_to_connect, host)
3464 if (!permit || !permit_adm) {
3465 logit("Received request to connect to host %.100s port %d, "
3466 "but the request was denied.", host, port);
3469 return connect_to(host, port, ctype, rname);
3473 channel_send_window_changes(void)
3478 for (i = 0; i < channels_alloc; i++) {
3479 if (channels[i] == NULL || !channels[i]->client_tty ||
3480 channels[i]->type != SSH_CHANNEL_OPEN)
3482 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3484 channel_request_start(i, "window-change", 0);
3485 packet_put_int((u_int)ws.ws_col);
3486 packet_put_int((u_int)ws.ws_row);
3487 packet_put_int((u_int)ws.ws_xpixel);
3488 packet_put_int((u_int)ws.ws_ypixel);
3493 /* -- X11 forwarding */
3496 * Creates an internet domain socket for listening for X11 connections.
3497 * Returns 0 and a suitable display number for the DISPLAY variable
3498 * stored in display_numberp , or -1 if an error occurs.
3501 x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3502 int single_connection, u_int *display_numberp, int **chanids)
3505 int display_number, sock;
3507 struct addrinfo hints, *ai, *aitop;
3508 char strport[NI_MAXSERV];
3509 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3511 if (chanids == NULL)
3514 for (display_number = x11_display_offset;
3515 display_number < MAX_DISPLAYS;
3517 port = 6000 + display_number;
3518 memset(&hints, 0, sizeof(hints));
3519 hints.ai_family = IPv4or6;
3520 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3521 hints.ai_socktype = SOCK_STREAM;
3522 snprintf(strport, sizeof strport, "%d", port);
3523 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3524 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3527 for (ai = aitop; ai; ai = ai->ai_next) {
3528 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3530 sock = socket(ai->ai_family, ai->ai_socktype,
3533 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3535 && (errno != EPFNOSUPPORT)
3538 error("socket: %.100s", strerror(errno));
3539 freeaddrinfo(aitop);
3542 debug("x11_create_display_inet: Socket family %d not supported",
3547 if (ai->ai_family == AF_INET6)
3548 sock_set_v6only(sock);
3549 if (x11_use_localhost)
3550 channel_set_reuseaddr(sock);
3551 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3552 debug2("bind port %d: %.100s", port, strerror(errno));
3555 for (n = 0; n < num_socks; n++) {
3561 socks[num_socks++] = sock;
3562 if (num_socks == NUM_SOCKS)
3565 freeaddrinfo(aitop);
3569 if (display_number >= MAX_DISPLAYS) {
3570 error("Failed to allocate internet-domain X11 display socket.");
3573 /* Start listening for connections on the socket. */
3574 for (n = 0; n < num_socks; n++) {
3576 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3577 error("listen: %.100s", strerror(errno));
3583 /* Allocate a channel for each socket. */
3584 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3585 for (n = 0; n < num_socks; n++) {
3588 nc = channel_new("x11 listener",
3589 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3590 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3591 0, "X11 inet listener", 1);
3593 nc = channel_new("x11 listener",
3594 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3595 buffer_size, CHAN_X11_PACKET_DEFAULT,
3596 0, "X11 inet listener", 1);
3597 nc->single_connection = single_connection;
3598 (*chanids)[n] = nc->self;
3602 /* Return the display number for the DISPLAY environment variable. */
3603 *display_numberp = display_number;
3608 connect_local_xsocket_path(const char *pathname)
3611 struct sockaddr_un addr;
3613 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3615 error("socket: %.100s", strerror(errno));
3616 memset(&addr, 0, sizeof(addr));
3617 addr.sun_family = AF_UNIX;
3618 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3619 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3622 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3627 connect_local_xsocket(u_int dnr)
3630 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3631 return connect_local_xsocket_path(buf);
3635 x11_connect_display(void)
3637 u_int display_number;
3638 const char *display;
3639 char buf[1024], *cp;
3640 struct addrinfo hints, *ai, *aitop;
3641 char strport[NI_MAXSERV];
3642 int gaierr, sock = 0;
3644 /* Try to open a socket for the local X server. */
3645 display = getenv("DISPLAY");
3647 error("DISPLAY not set.");
3651 * Now we decode the value of the DISPLAY variable and make a
3652 * connection to the real X server.
3655 /* Check if the display is from launchd. */
3657 if (strncmp(display, "/tmp/launch", 11) == 0) {
3658 sock = connect_local_xsocket_path(display);
3662 /* OK, we now have a connection to the display. */
3667 * Check if it is a unix domain socket. Unix domain displays are in
3668 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3670 if (strncmp(display, "unix:", 5) == 0 ||
3671 display[0] == ':') {
3672 /* Connect to the unix domain socket. */
3673 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3674 error("Could not parse display number from DISPLAY: %.100s",
3678 /* Create a socket. */
3679 sock = connect_local_xsocket(display_number);
3683 /* OK, we now have a connection to the display. */
3687 * Connect to an inet socket. The DISPLAY value is supposedly
3688 * hostname:d[.s], where hostname may also be numeric IP address.
3690 strlcpy(buf, display, sizeof(buf));
3691 cp = strchr(buf, ':');
3693 error("Could not find ':' in DISPLAY: %.100s", display);
3697 /* buf now contains the host name. But first we parse the display number. */
3698 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3699 error("Could not parse display number from DISPLAY: %.100s",
3704 /* Look up the host address */
3705 memset(&hints, 0, sizeof(hints));
3706 hints.ai_family = IPv4or6;
3707 hints.ai_socktype = SOCK_STREAM;
3708 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3709 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3710 error("%.100s: unknown host. (%s)", buf,
3711 ssh_gai_strerror(gaierr));
3714 for (ai = aitop; ai; ai = ai->ai_next) {
3715 /* Create a socket. */
3716 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3718 debug2("socket: %.100s", strerror(errno));
3721 /* Connect it to the display. */
3722 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3723 debug2("connect %.100s port %u: %.100s", buf,
3724 6000 + display_number, strerror(errno));
3731 freeaddrinfo(aitop);
3733 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3742 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3743 * the remote channel number. We should do whatever we want, and respond
3744 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3749 x11_input_open(int type, u_int32_t seq, void *ctxt)
3752 int remote_id, sock = 0;
3755 debug("Received X11 open request.");
3757 remote_id = packet_get_int();
3759 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3760 remote_host = packet_get_string(NULL);
3762 remote_host = xstrdup("unknown (remote did not supply name)");
3766 /* Obtain a connection to the real X display. */
3767 sock = x11_connect_display();
3769 /* Allocate a channel for this connection. */
3770 c = channel_new("connected x11 socket",
3771 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3773 c->remote_id = remote_id;
3778 /* Send refusal to the remote host. */
3779 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3780 packet_put_int(remote_id);
3782 /* Send a confirmation to the remote host. */
3783 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3784 packet_put_int(remote_id);
3785 packet_put_int(c->self);
3790 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3793 deny_input_open(int type, u_int32_t seq, void *ctxt)
3795 int rchan = packet_get_int();
3798 case SSH_SMSG_AGENT_OPEN:
3799 error("Warning: ssh server tried agent forwarding.");
3801 case SSH_SMSG_X11_OPEN:
3802 error("Warning: ssh server tried X11 forwarding.");
3805 error("deny_input_open: type %d", type);
3808 error("Warning: this is probably a break-in attempt by a malicious server.");
3809 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3810 packet_put_int(rchan);
3815 * Requests forwarding of X11 connections, generates fake authentication
3816 * data, and enables authentication spoofing.
3817 * This should be called in the client only.
3820 x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3821 const char *proto, const char *data, int want_reply)
3823 u_int data_len = (u_int) strlen(data) / 2;
3830 if (x11_saved_display == NULL)
3831 x11_saved_display = xstrdup(disp);
3832 else if (strcmp(disp, x11_saved_display) != 0) {
3833 error("x11_request_forwarding_with_spoofing: different "
3834 "$DISPLAY already forwarded");
3838 cp = strchr(disp, ':');
3840 cp = strchr(cp, '.');
3842 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3846 if (x11_saved_proto == NULL) {
3847 /* Save protocol name. */
3848 x11_saved_proto = xstrdup(proto);
3850 * Extract real authentication data and generate fake data
3851 * of the same length.
3853 x11_saved_data = xmalloc(data_len);
3854 x11_fake_data = xmalloc(data_len);
3855 for (i = 0; i < data_len; i++) {
3856 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3857 fatal("x11_request_forwarding: bad "
3858 "authentication data: %.100s", data);
3861 x11_saved_data[i] = value;
3862 x11_fake_data[i] = rnd & 0xff;
3865 x11_saved_data_len = data_len;
3866 x11_fake_data_len = data_len;
3869 /* Convert the fake data into hex. */
3870 new_data = tohex(x11_fake_data, data_len);
3872 /* Send the request packet. */
3874 channel_request_start(client_session_id, "x11-req", want_reply);
3875 packet_put_char(0); /* XXX bool single connection */
3877 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3879 packet_put_cstring(proto);
3880 packet_put_cstring(new_data);
3881 packet_put_int(screen_number);
3883 packet_write_wait();
3888 /* -- agent forwarding */
3890 /* Sends a message to the server to request authentication fd forwarding. */
3893 auth_request_forwarding(void)
3895 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3897 packet_write_wait();