2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * This file contains functions for generic socket connection forwarding.
6 * There is also code for initiating connection forwarding for X11 connections,
7 * arbitrary tcp/ip connections, and the authentication agent connection.
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
15 * SSH2 support added by Markus Friedl.
16 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
17 * Copyright (c) 1999 Dug Song. All rights reserved.
18 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimer in the
27 * documentation and/or other materials provided with the distribution.
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 RCSID("$OpenBSD: channels.c,v 1.200 2004/01/19 09:24:21 markus Exp $");
56 #include "pathnames.h"
62 * Pointer to an array containing all allocated channels. The array is
63 * dynamically extended as needed.
65 static Channel
**channels
= NULL
;
68 * Size of the channel array. All slots of the array must always be
69 * initialized (at least the type field); unused slots set to NULL
71 static int channels_alloc
= 0;
74 * Maximum file descriptor value used in any of the channels. This is
75 * updated in channel_new.
77 static int channel_max_fd
= 0;
80 /* -- tcp forwarding */
83 * Data structure for storing which hosts are permitted for forward requests.
84 * The local sides of any remote forwards are stored in this array to prevent
85 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86 * network (which might be behind a firewall).
89 char *host_to_connect
; /* Connect to 'host'. */
90 u_short port_to_connect
; /* Connect to 'port'. */
91 u_short listen_port
; /* Remote side should listen port number. */
94 /* List of all permitted host/port pairs to connect. */
95 static ForwardPermission permitted_opens
[SSH_MAX_FORWARDS_PER_DIRECTION
];
97 /* Number of permitted host/port pairs in the array. */
98 static int num_permitted_opens
= 0;
100 * If this is true, all opens are permitted. This is the case on the server
101 * on which we have to trust the client anyway, and the user could do
102 * anything after logging in anyway.
104 static int all_opens_permitted
= 0;
107 /* -- X11 forwarding */
109 /* Maximum number of fake X11 displays to try. */
110 #define MAX_DISPLAYS 1000
112 /* Saved X11 authentication protocol name. */
113 static char *x11_saved_proto
= NULL
;
115 /* Saved X11 authentication data. This is the real data. */
116 static char *x11_saved_data
= NULL
;
117 static u_int x11_saved_data_len
= 0;
120 * Fake X11 authentication data. This is what the server will be sending us;
121 * we should replace any occurrences of this by the real data.
123 static char *x11_fake_data
= NULL
;
124 static u_int x11_fake_data_len
;
127 /* -- agent forwarding */
131 /* AF_UNSPEC or AF_INET or AF_INET6 */
132 static int IPv4or6
= AF_UNSPEC
;
135 static void port_open_helper(Channel
*c
, char *rtype
);
137 /* -- channel core */
140 channel_lookup(int id
)
144 if (id
< 0 || id
>= channels_alloc
) {
145 logit("channel_lookup: %d: bad id", id
);
150 logit("channel_lookup: %d: bad id: channel free", id
);
157 * Register filedescriptors for a channel, used when allocating a channel or
158 * when the channel consumer/producer is ready, e.g. shell exec'd
162 channel_register_fds(Channel
*c
, int rfd
, int wfd
, int efd
,
163 int extusage
, int nonblock
)
165 /* Update the maximum file descriptor value. */
166 channel_max_fd
= MAX(channel_max_fd
, rfd
);
167 channel_max_fd
= MAX(channel_max_fd
, wfd
);
168 channel_max_fd
= MAX(channel_max_fd
, efd
);
170 /* XXX set close-on-exec -markus */
174 c
->sock
= (rfd
== wfd
) ? rfd
: -1;
176 c
->extended_usage
= extusage
;
178 /* XXX ugly hack: nonblock is only set by the server */
179 if (nonblock
&& isatty(c
->rfd
)) {
180 debug2("channel %d: rfd %d isatty", c
->self
, c
->rfd
);
182 if (!isatty(c
->wfd
)) {
183 error("channel %d: wfd %d is not a tty?",
189 c
->wfd_isatty
= isatty(c
->wfd
);
191 /* enable nonblocking mode */
203 * Allocate a new channel object and set its type and socket. This will cause
204 * remote_name to be freed.
208 channel_new(char *ctype
, int type
, int rfd
, int wfd
, int efd
,
209 u_int window
, u_int maxpack
, int extusage
, char *remote_name
, int nonblock
)
214 /* Do initial allocation if this is the first call. */
215 if (channels_alloc
== 0) {
217 channels
= xmalloc(channels_alloc
* sizeof(Channel
*));
218 for (i
= 0; i
< channels_alloc
; i
++)
221 /* Try to find a free slot where to put the new channel. */
222 for (found
= -1, i
= 0; i
< channels_alloc
; i
++)
223 if (channels
[i
] == NULL
) {
224 /* Found a free slot. */
229 /* There are no free slots. Take last+1 slot and expand the array. */
230 found
= channels_alloc
;
231 if (channels_alloc
> 10000)
232 fatal("channel_new: internal error: channels_alloc %d "
233 "too big.", channels_alloc
);
234 channels
= xrealloc(channels
,
235 (channels_alloc
+ 10) * sizeof(Channel
*));
236 channels_alloc
+= 10;
237 debug2("channel: expanding %d", channels_alloc
);
238 for (i
= found
; i
< channels_alloc
; i
++)
241 /* Initialize and return new channel. */
242 c
= channels
[found
] = xmalloc(sizeof(Channel
));
243 memset(c
, 0, sizeof(Channel
));
244 buffer_init(&c
->input
);
245 buffer_init(&c
->output
);
246 buffer_init(&c
->extended
);
247 c
->ostate
= CHAN_OUTPUT_OPEN
;
248 c
->istate
= CHAN_INPUT_OPEN
;
250 channel_register_fds(c
, rfd
, wfd
, efd
, extusage
, nonblock
);
254 c
->local_window
= window
;
255 c
->local_window_max
= window
;
256 c
->local_consumed
= 0;
257 c
->local_maxpacket
= maxpack
;
259 c
->remote_name
= xstrdup(remote_name
);
260 c
->remote_window
= 0;
261 c
->remote_maxpacket
= 0;
263 c
->single_connection
= 0;
264 c
->detach_user
= NULL
;
266 c
->input_filter
= NULL
;
267 debug("channel %d: new [%s]", found
, remote_name
);
272 channel_find_maxfd(void)
277 for (i
= 0; i
< channels_alloc
; i
++) {
280 max
= MAX(max
, c
->rfd
);
281 max
= MAX(max
, c
->wfd
);
282 max
= MAX(max
, c
->efd
);
289 channel_close_fd(int *fdp
)
291 int ret
= 0, fd
= *fdp
;
296 if (fd
== channel_max_fd
)
297 channel_max_fd
= channel_find_maxfd();
302 /* Close all channel fd/socket. */
305 channel_close_fds(Channel
*c
)
307 debug3("channel %d: close_fds r %d w %d e %d",
308 c
->self
, c
->rfd
, c
->wfd
, c
->efd
);
310 channel_close_fd(&c
->sock
);
311 channel_close_fd(&c
->rfd
);
312 channel_close_fd(&c
->wfd
);
313 channel_close_fd(&c
->efd
);
316 /* Free the channel and close its fd/socket. */
319 channel_free(Channel
*c
)
324 for (n
= 0, i
= 0; i
< channels_alloc
; i
++)
327 debug("channel %d: free: %s, nchannels %d", c
->self
,
328 c
->remote_name
? c
->remote_name
: "???", n
);
330 s
= channel_open_message();
331 debug3("channel %d: status: %s", c
->self
, s
);
335 shutdown(c
->sock
, SHUT_RDWR
);
336 channel_close_fds(c
);
337 buffer_free(&c
->input
);
338 buffer_free(&c
->output
);
339 buffer_free(&c
->extended
);
340 if (c
->remote_name
) {
341 xfree(c
->remote_name
);
342 c
->remote_name
= NULL
;
344 channels
[c
->self
] = NULL
;
349 channel_free_all(void)
353 for (i
= 0; i
< channels_alloc
; i
++)
354 if (channels
[i
] != NULL
)
355 channel_free(channels
[i
]);
359 * Closes the sockets/fds of all channels. This is used to close extra file
360 * descriptors after a fork.
364 channel_close_all(void)
368 for (i
= 0; i
< channels_alloc
; i
++)
369 if (channels
[i
] != NULL
)
370 channel_close_fds(channels
[i
]);
374 * Stop listening to channels.
378 channel_stop_listening(void)
383 for (i
= 0; i
< channels_alloc
; i
++) {
387 case SSH_CHANNEL_AUTH_SOCKET
:
388 case SSH_CHANNEL_PORT_LISTENER
:
389 case SSH_CHANNEL_RPORT_LISTENER
:
390 case SSH_CHANNEL_X11_LISTENER
:
391 channel_close_fd(&c
->sock
);
400 * Returns true if no channel has too much buffered data, and false if one or
401 * more channel is overfull.
405 channel_not_very_much_buffered_data(void)
410 for (i
= 0; i
< channels_alloc
; i
++) {
412 if (c
!= NULL
&& c
->type
== SSH_CHANNEL_OPEN
) {
415 buffer_len(&c
->input
) > packet_get_maxsize()) {
416 debug2("channel %d: big input buffer %d",
417 c
->self
, buffer_len(&c
->input
));
421 if (buffer_len(&c
->output
) > packet_get_maxsize()) {
422 debug2("channel %d: big output buffer %u > %u",
423 c
->self
, buffer_len(&c
->output
),
424 packet_get_maxsize());
432 /* Returns true if any channel is still open. */
435 channel_still_open(void)
440 for (i
= 0; i
< channels_alloc
; i
++) {
445 case SSH_CHANNEL_X11_LISTENER
:
446 case SSH_CHANNEL_PORT_LISTENER
:
447 case SSH_CHANNEL_RPORT_LISTENER
:
448 case SSH_CHANNEL_CLOSED
:
449 case SSH_CHANNEL_AUTH_SOCKET
:
450 case SSH_CHANNEL_DYNAMIC
:
451 case SSH_CHANNEL_CONNECTING
:
452 case SSH_CHANNEL_ZOMBIE
:
454 case SSH_CHANNEL_LARVAL
:
456 fatal("cannot happen: SSH_CHANNEL_LARVAL");
458 case SSH_CHANNEL_OPENING
:
459 case SSH_CHANNEL_OPEN
:
460 case SSH_CHANNEL_X11_OPEN
:
462 case SSH_CHANNEL_INPUT_DRAINING
:
463 case SSH_CHANNEL_OUTPUT_DRAINING
:
465 fatal("cannot happen: OUT_DRAIN");
468 fatal("channel_still_open: bad channel type %d", c
->type
);
475 /* Returns the id of an open channel suitable for keepaliving */
478 channel_find_open(void)
483 for (i
= 0; i
< channels_alloc
; i
++) {
488 case SSH_CHANNEL_CLOSED
:
489 case SSH_CHANNEL_DYNAMIC
:
490 case SSH_CHANNEL_X11_LISTENER
:
491 case SSH_CHANNEL_PORT_LISTENER
:
492 case SSH_CHANNEL_RPORT_LISTENER
:
493 case SSH_CHANNEL_OPENING
:
494 case SSH_CHANNEL_CONNECTING
:
495 case SSH_CHANNEL_ZOMBIE
:
497 case SSH_CHANNEL_LARVAL
:
498 case SSH_CHANNEL_AUTH_SOCKET
:
499 case SSH_CHANNEL_OPEN
:
500 case SSH_CHANNEL_X11_OPEN
:
502 case SSH_CHANNEL_INPUT_DRAINING
:
503 case SSH_CHANNEL_OUTPUT_DRAINING
:
505 fatal("cannot happen: OUT_DRAIN");
508 fatal("channel_find_open: bad channel type %d", c
->type
);
517 * Returns a message describing the currently open forwarded connections,
518 * suitable for sending to the client. The message contains crlf pairs for
523 channel_open_message(void)
530 buffer_init(&buffer
);
531 snprintf(buf
, sizeof buf
, "The following connections are open:\r\n");
532 buffer_append(&buffer
, buf
, strlen(buf
));
533 for (i
= 0; i
< channels_alloc
; i
++) {
538 case SSH_CHANNEL_X11_LISTENER
:
539 case SSH_CHANNEL_PORT_LISTENER
:
540 case SSH_CHANNEL_RPORT_LISTENER
:
541 case SSH_CHANNEL_CLOSED
:
542 case SSH_CHANNEL_AUTH_SOCKET
:
543 case SSH_CHANNEL_ZOMBIE
:
545 case SSH_CHANNEL_LARVAL
:
546 case SSH_CHANNEL_OPENING
:
547 case SSH_CHANNEL_CONNECTING
:
548 case SSH_CHANNEL_DYNAMIC
:
549 case SSH_CHANNEL_OPEN
:
550 case SSH_CHANNEL_X11_OPEN
:
551 case SSH_CHANNEL_INPUT_DRAINING
:
552 case SSH_CHANNEL_OUTPUT_DRAINING
:
553 snprintf(buf
, sizeof buf
, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
554 c
->self
, c
->remote_name
,
555 c
->type
, c
->remote_id
,
556 c
->istate
, buffer_len(&c
->input
),
557 c
->ostate
, buffer_len(&c
->output
),
559 buffer_append(&buffer
, buf
, strlen(buf
));
562 fatal("channel_open_message: bad channel type %d", c
->type
);
566 buffer_append(&buffer
, "\0", 1);
567 cp
= xstrdup(buffer_ptr(&buffer
));
568 buffer_free(&buffer
);
573 channel_send_open(int id
)
575 Channel
*c
= channel_lookup(id
);
578 logit("channel_send_open: %d: bad id", id
);
581 debug2("channel %d: send open", id
);
582 packet_start(SSH2_MSG_CHANNEL_OPEN
);
583 packet_put_cstring(c
->ctype
);
584 packet_put_int(c
->self
);
585 packet_put_int(c
->local_window
);
586 packet_put_int(c
->local_maxpacket
);
591 channel_request_start(int id
, char *service
, int wantconfirm
)
593 Channel
*c
= channel_lookup(id
);
596 logit("channel_request_start: %d: unknown channel id", id
);
599 debug2("channel %d: request %s", id
, service
) ;
600 packet_start(SSH2_MSG_CHANNEL_REQUEST
);
601 packet_put_int(c
->remote_id
);
602 packet_put_cstring(service
);
603 packet_put_char(wantconfirm
);
606 channel_register_confirm(int id
, channel_callback_fn
*fn
)
608 Channel
*c
= channel_lookup(id
);
611 logit("channel_register_comfirm: %d: bad id", id
);
617 channel_register_cleanup(int id
, channel_callback_fn
*fn
)
619 Channel
*c
= channel_lookup(id
);
622 logit("channel_register_cleanup: %d: bad id", id
);
628 channel_cancel_cleanup(int id
)
630 Channel
*c
= channel_lookup(id
);
633 logit("channel_cancel_cleanup: %d: bad id", id
);
636 c
->detach_user
= NULL
;
639 channel_register_filter(int id
, channel_filter_fn
*fn
)
641 Channel
*c
= channel_lookup(id
);
644 logit("channel_register_filter: %d: bad id", id
);
647 c
->input_filter
= fn
;
651 channel_set_fds(int id
, int rfd
, int wfd
, int efd
,
652 int extusage
, int nonblock
, u_int window_max
)
654 Channel
*c
= channel_lookup(id
);
656 if (c
== NULL
|| c
->type
!= SSH_CHANNEL_LARVAL
)
657 fatal("channel_activate for non-larval channel %d.", id
);
658 channel_register_fds(c
, rfd
, wfd
, efd
, extusage
, nonblock
);
659 c
->type
= SSH_CHANNEL_OPEN
;
660 c
->local_window
= c
->local_window_max
= window_max
;
661 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
662 packet_put_int(c
->remote_id
);
663 packet_put_int(c
->local_window
);
668 * 'channel_pre*' are called just before select() to add any bits relevant to
669 * channels in the select bitmasks.
672 * 'channel_post*': perform any appropriate operations for channels which
673 * have events pending.
675 typedef void chan_fn(Channel
*c
, fd_set
* readset
, fd_set
* writeset
);
676 chan_fn
*channel_pre
[SSH_CHANNEL_MAX_TYPE
];
677 chan_fn
*channel_post
[SSH_CHANNEL_MAX_TYPE
];
680 channel_pre_listener(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
682 FD_SET(c
->sock
, readset
);
686 channel_pre_connecting(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
688 debug3("channel %d: waiting for connection", c
->self
);
689 FD_SET(c
->sock
, writeset
);
693 channel_pre_open_13(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
695 if (buffer_len(&c
->input
) < packet_get_maxsize())
696 FD_SET(c
->sock
, readset
);
697 if (buffer_len(&c
->output
) > 0)
698 FD_SET(c
->sock
, writeset
);
702 channel_pre_open(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
704 u_int limit
= compat20
? c
->remote_window
: packet_get_maxsize();
706 if (c
->istate
== CHAN_INPUT_OPEN
&&
708 buffer_len(&c
->input
) < limit
)
709 FD_SET(c
->rfd
, readset
);
710 if (c
->ostate
== CHAN_OUTPUT_OPEN
||
711 c
->ostate
== CHAN_OUTPUT_WAIT_DRAIN
) {
712 if (buffer_len(&c
->output
) > 0) {
713 FD_SET(c
->wfd
, writeset
);
714 } else if (c
->ostate
== CHAN_OUTPUT_WAIT_DRAIN
) {
715 if (CHANNEL_EFD_OUTPUT_ACTIVE(c
))
716 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
717 c
->self
, c
->efd
, buffer_len(&c
->extended
));
722 /** XXX check close conditions, too */
723 if (compat20
&& c
->efd
!= -1) {
724 if (c
->extended_usage
== CHAN_EXTENDED_WRITE
&&
725 buffer_len(&c
->extended
) > 0)
726 FD_SET(c
->efd
, writeset
);
727 else if (!(c
->flags
& CHAN_EOF_SENT
) &&
728 c
->extended_usage
== CHAN_EXTENDED_READ
&&
729 buffer_len(&c
->extended
) < c
->remote_window
)
730 FD_SET(c
->efd
, readset
);
735 channel_pre_input_draining(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
737 if (buffer_len(&c
->input
) == 0) {
738 packet_start(SSH_MSG_CHANNEL_CLOSE
);
739 packet_put_int(c
->remote_id
);
741 c
->type
= SSH_CHANNEL_CLOSED
;
742 debug2("channel %d: closing after input drain.", c
->self
);
747 channel_pre_output_draining(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
749 if (buffer_len(&c
->output
) == 0)
752 FD_SET(c
->sock
, writeset
);
756 * This is a special state for X11 authentication spoofing. An opened X11
757 * connection (when authentication spoofing is being done) remains in this
758 * state until the first packet has been completely read. The authentication
759 * data in that packet is then substituted by the real data if it matches the
760 * fake data, and the channel is put into normal mode.
761 * XXX All this happens at the client side.
762 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
765 x11_open_helper(Buffer
*b
)
768 u_int proto_len
, data_len
;
770 /* Check if the fixed size part of the packet is in buffer. */
771 if (buffer_len(b
) < 12)
774 /* Parse the lengths of variable-length fields. */
776 if (ucp
[0] == 0x42) { /* Byte order MSB first. */
777 proto_len
= 256 * ucp
[6] + ucp
[7];
778 data_len
= 256 * ucp
[8] + ucp
[9];
779 } else if (ucp
[0] == 0x6c) { /* Byte order LSB first. */
780 proto_len
= ucp
[6] + 256 * ucp
[7];
781 data_len
= ucp
[8] + 256 * ucp
[9];
783 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
788 /* Check if the whole packet is in buffer. */
790 12 + ((proto_len
+ 3) & ~3) + ((data_len
+ 3) & ~3))
793 /* Check if authentication protocol matches. */
794 if (proto_len
!= strlen(x11_saved_proto
) ||
795 memcmp(ucp
+ 12, x11_saved_proto
, proto_len
) != 0) {
796 debug2("X11 connection uses different authentication protocol.");
799 /* Check if authentication data matches our fake data. */
800 if (data_len
!= x11_fake_data_len
||
801 memcmp(ucp
+ 12 + ((proto_len
+ 3) & ~3),
802 x11_fake_data
, x11_fake_data_len
) != 0) {
803 debug2("X11 auth data does not match fake data.");
806 /* Check fake data length */
807 if (x11_fake_data_len
!= x11_saved_data_len
) {
808 error("X11 fake_data_len %d != saved_data_len %d",
809 x11_fake_data_len
, x11_saved_data_len
);
813 * Received authentication protocol and data match
814 * our fake data. Substitute the fake data with real
817 memcpy(ucp
+ 12 + ((proto_len
+ 3) & ~3),
818 x11_saved_data
, x11_saved_data_len
);
823 channel_pre_x11_open_13(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
825 int ret
= x11_open_helper(&c
->output
);
828 /* Start normal processing for the channel. */
829 c
->type
= SSH_CHANNEL_OPEN
;
830 channel_pre_open_13(c
, readset
, writeset
);
831 } else if (ret
== -1) {
833 * We have received an X11 connection that has bad
834 * authentication information.
836 logit("X11 connection rejected because of wrong authentication.");
837 buffer_clear(&c
->input
);
838 buffer_clear(&c
->output
);
839 channel_close_fd(&c
->sock
);
841 c
->type
= SSH_CHANNEL_CLOSED
;
842 packet_start(SSH_MSG_CHANNEL_CLOSE
);
843 packet_put_int(c
->remote_id
);
849 channel_pre_x11_open(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
851 int ret
= x11_open_helper(&c
->output
);
853 /* c->force_drain = 1; */
856 c
->type
= SSH_CHANNEL_OPEN
;
857 channel_pre_open(c
, readset
, writeset
);
858 } else if (ret
== -1) {
859 logit("X11 connection rejected because of wrong authentication.");
860 debug2("X11 rejected %d i%d/o%d", c
->self
, c
->istate
, c
->ostate
);
862 buffer_clear(&c
->input
);
864 buffer_clear(&c
->output
);
865 /* for proto v1, the peer will send an IEOF */
867 chan_write_failed(c
);
869 c
->type
= SSH_CHANNEL_OPEN
;
870 debug2("X11 closed %d i%d/o%d", c
->self
, c
->istate
, c
->ostate
);
874 /* try to decode a socks4 header */
876 channel_decode_socks4(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
879 int len
, have
, i
, found
;
885 struct in_addr dest_addr
;
888 debug2("channel %d: decode socks4", c
->self
);
890 have
= buffer_len(&c
->input
);
891 len
= sizeof(s4_req
);
894 p
= buffer_ptr(&c
->input
);
895 for (found
= 0, i
= len
; i
< have
; i
++) {
901 /* the peer is probably sending garbage */
902 debug("channel %d: decode socks4: too long",
909 buffer_get(&c
->input
, (char *)&s4_req
.version
, 1);
910 buffer_get(&c
->input
, (char *)&s4_req
.command
, 1);
911 buffer_get(&c
->input
, (char *)&s4_req
.dest_port
, 2);
912 buffer_get(&c
->input
, (char *)&s4_req
.dest_addr
, 4);
913 have
= buffer_len(&c
->input
);
914 p
= buffer_ptr(&c
->input
);
916 debug2("channel %d: decode socks4: user %s/%d", c
->self
, p
, len
);
918 fatal("channel %d: decode socks4: len %d > have %d",
920 strlcpy(username
, p
, sizeof(username
));
921 buffer_consume(&c
->input
, len
);
922 buffer_consume(&c
->input
, 1); /* trailing '\0' */
924 host
= inet_ntoa(s4_req
.dest_addr
);
925 strlcpy(c
->path
, host
, sizeof(c
->path
));
926 c
->host_port
= ntohs(s4_req
.dest_port
);
928 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
929 c
->self
, host
, c
->host_port
, s4_req
.command
);
931 if (s4_req
.command
!= 1) {
932 debug("channel %d: cannot handle: socks4 cn %d",
933 c
->self
, s4_req
.command
);
936 s4_rsp
.version
= 0; /* vn: 0 for reply */
937 s4_rsp
.command
= 90; /* cd: req granted */
938 s4_rsp
.dest_port
= 0; /* ignored */
939 s4_rsp
.dest_addr
.s_addr
= INADDR_ANY
; /* ignored */
940 buffer_append(&c
->output
, (char *)&s4_rsp
, sizeof(s4_rsp
));
944 /* try to decode a socks5 header */
945 #define SSH_SOCKS5_AUTHDONE 0x1000
946 #define SSH_SOCKS5_NOAUTH 0x00
947 #define SSH_SOCKS5_IPV4 0x01
948 #define SSH_SOCKS5_DOMAIN 0x03
949 #define SSH_SOCKS5_IPV6 0x04
950 #define SSH_SOCKS5_CONNECT 0x01
951 #define SSH_SOCKS5_SUCCESS 0x00
954 channel_decode_socks5(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
963 u_char
*p
, dest_addr
[255+1];
964 int i
, have
, found
, nmethods
, addrlen
, af
;
966 debug2("channel %d: decode socks5", c
->self
);
967 p
= buffer_ptr(&c
->input
);
970 have
= buffer_len(&c
->input
);
971 if (!(c
->flags
& SSH_SOCKS5_AUTHDONE
)) {
972 /* format: ver | nmethods | methods */
976 if (have
< nmethods
+ 2)
978 /* look for method: "NO AUTHENTICATION REQUIRED" */
979 for (found
= 0, i
= 2 ; i
< nmethods
+ 2; i
++) {
980 if (p
[i
] == SSH_SOCKS5_NOAUTH
) {
986 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
990 buffer_consume(&c
->input
, nmethods
+ 2);
991 buffer_put_char(&c
->output
, 0x05); /* version */
992 buffer_put_char(&c
->output
, SSH_SOCKS5_NOAUTH
); /* method */
993 FD_SET(c
->sock
, writeset
);
994 c
->flags
|= SSH_SOCKS5_AUTHDONE
;
995 debug2("channel %d: socks5 auth done", c
->self
);
996 return 0; /* need more */
998 debug2("channel %d: socks5 post auth", c
->self
);
999 if (have
< sizeof(s5_req
)+1)
1000 return 0; /* need more */
1001 memcpy((char *)&s5_req
, p
, sizeof(s5_req
));
1002 if (s5_req
.version
!= 0x05 ||
1003 s5_req
.command
!= SSH_SOCKS5_CONNECT
||
1004 s5_req
.reserved
!= 0x00) {
1005 debug2("channel %d: only socks5 connect supported", c
->self
);
1008 switch(s5_req
.atyp
){
1009 case SSH_SOCKS5_IPV4
:
1013 case SSH_SOCKS5_DOMAIN
:
1014 addrlen
= p
[sizeof(s5_req
)];
1017 case SSH_SOCKS5_IPV6
:
1022 debug2("channel %d: bad socks5 atyp %d", c
->self
, s5_req
.atyp
);
1025 if (have
< 4 + addrlen
+ 2)
1027 buffer_consume(&c
->input
, sizeof(s5_req
));
1028 if (s5_req
.atyp
== SSH_SOCKS5_DOMAIN
)
1029 buffer_consume(&c
->input
, 1); /* host string length */
1030 buffer_get(&c
->input
, (char *)&dest_addr
, addrlen
);
1031 buffer_get(&c
->input
, (char *)&dest_port
, 2);
1032 dest_addr
[addrlen
] = '\0';
1033 if (s5_req
.atyp
== SSH_SOCKS5_DOMAIN
)
1034 strlcpy(c
->path
, dest_addr
, sizeof(c
->path
));
1035 else if (inet_ntop(af
, dest_addr
, c
->path
, sizeof(c
->path
)) == NULL
)
1037 c
->host_port
= ntohs(dest_port
);
1039 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1040 c
->self
, c
->path
, c
->host_port
, s5_req
.command
);
1042 s5_rsp
.version
= 0x05;
1043 s5_rsp
.command
= SSH_SOCKS5_SUCCESS
;
1044 s5_rsp
.reserved
= 0; /* ignored */
1045 s5_rsp
.atyp
= SSH_SOCKS5_IPV4
;
1046 ((struct in_addr
*)&dest_addr
)->s_addr
= INADDR_ANY
;
1047 dest_port
= 0; /* ignored */
1049 buffer_append(&c
->output
, (char *)&s5_rsp
, sizeof(s5_rsp
));
1050 buffer_append(&c
->output
, (char *)&dest_addr
, sizeof(struct in_addr
));
1051 buffer_append(&c
->output
, (char *)&dest_port
, sizeof(dest_port
));
1055 /* dynamic port forwarding */
1057 channel_pre_dynamic(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1062 have
= buffer_len(&c
->input
);
1064 debug2("channel %d: pre_dynamic: have %d", c
->self
, have
);
1065 /* buffer_dump(&c->input); */
1066 /* check if the fixed size part of the packet is in buffer. */
1069 FD_SET(c
->sock
, readset
);
1072 /* try to guess the protocol */
1073 p
= buffer_ptr(&c
->input
);
1076 ret
= channel_decode_socks4(c
, readset
, writeset
);
1079 ret
= channel_decode_socks5(c
, readset
, writeset
);
1087 } else if (ret
== 0) {
1088 debug2("channel %d: pre_dynamic: need more", c
->self
);
1090 FD_SET(c
->sock
, readset
);
1092 /* switch to the next state */
1093 c
->type
= SSH_CHANNEL_OPENING
;
1094 port_open_helper(c
, "direct-tcpip");
1098 /* This is our fake X11 server socket. */
1100 channel_post_x11_listener(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1103 struct sockaddr addr
;
1106 char buf
[16384], *remote_ipaddr
;
1109 if (FD_ISSET(c
->sock
, readset
)) {
1110 debug("X11 connection requested.");
1111 addrlen
= sizeof(addr
);
1112 newsock
= accept(c
->sock
, &addr
, &addrlen
);
1113 if (c
->single_connection
) {
1114 debug2("single_connection: closing X11 listener.");
1115 channel_close_fd(&c
->sock
);
1119 error("accept: %.100s", strerror(errno
));
1122 set_nodelay(newsock
);
1123 remote_ipaddr
= get_peer_ipaddr(newsock
);
1124 remote_port
= get_peer_port(newsock
);
1125 snprintf(buf
, sizeof buf
, "X11 connection from %.200s port %d",
1126 remote_ipaddr
, remote_port
);
1128 nc
= channel_new("accepted x11 socket",
1129 SSH_CHANNEL_OPENING
, newsock
, newsock
, -1,
1130 c
->local_window_max
, c
->local_maxpacket
, 0, buf
, 1);
1132 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1133 packet_put_cstring("x11");
1134 packet_put_int(nc
->self
);
1135 packet_put_int(nc
->local_window_max
);
1136 packet_put_int(nc
->local_maxpacket
);
1137 /* originator ipaddr and port */
1138 packet_put_cstring(remote_ipaddr
);
1139 if (datafellows
& SSH_BUG_X11FWD
) {
1140 debug2("ssh2 x11 bug compat mode");
1142 packet_put_int(remote_port
);
1146 packet_start(SSH_SMSG_X11_OPEN
);
1147 packet_put_int(nc
->self
);
1148 if (packet_get_protocol_flags() &
1149 SSH_PROTOFLAG_HOST_IN_FWD_OPEN
)
1150 packet_put_cstring(buf
);
1153 xfree(remote_ipaddr
);
1158 port_open_helper(Channel
*c
, char *rtype
)
1162 char *remote_ipaddr
= get_peer_ipaddr(c
->sock
);
1163 u_short remote_port
= get_peer_port(c
->sock
);
1165 direct
= (strcmp(rtype
, "direct-tcpip") == 0);
1167 snprintf(buf
, sizeof buf
,
1168 "%s: listening port %d for %.100s port %d, "
1169 "connect from %.200s port %d",
1170 rtype
, c
->listening_port
, c
->path
, c
->host_port
,
1171 remote_ipaddr
, remote_port
);
1173 xfree(c
->remote_name
);
1174 c
->remote_name
= xstrdup(buf
);
1177 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1178 packet_put_cstring(rtype
);
1179 packet_put_int(c
->self
);
1180 packet_put_int(c
->local_window_max
);
1181 packet_put_int(c
->local_maxpacket
);
1183 /* target host, port */
1184 packet_put_cstring(c
->path
);
1185 packet_put_int(c
->host_port
);
1187 /* listen address, port */
1188 packet_put_cstring(c
->path
);
1189 packet_put_int(c
->listening_port
);
1191 /* originator host and port */
1192 packet_put_cstring(remote_ipaddr
);
1193 packet_put_int(remote_port
);
1196 packet_start(SSH_MSG_PORT_OPEN
);
1197 packet_put_int(c
->self
);
1198 packet_put_cstring(c
->path
);
1199 packet_put_int(c
->host_port
);
1200 if (packet_get_protocol_flags() &
1201 SSH_PROTOFLAG_HOST_IN_FWD_OPEN
)
1202 packet_put_cstring(c
->remote_name
);
1205 xfree(remote_ipaddr
);
1209 * This socket is listening for connections to a forwarded TCP/IP port.
1212 channel_post_port_listener(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1215 struct sockaddr addr
;
1216 int newsock
, nextstate
;
1220 if (FD_ISSET(c
->sock
, readset
)) {
1221 debug("Connection to port %d forwarding "
1222 "to %.100s port %d requested.",
1223 c
->listening_port
, c
->path
, c
->host_port
);
1225 if (c
->type
== SSH_CHANNEL_RPORT_LISTENER
) {
1226 nextstate
= SSH_CHANNEL_OPENING
;
1227 rtype
= "forwarded-tcpip";
1229 if (c
->host_port
== 0) {
1230 nextstate
= SSH_CHANNEL_DYNAMIC
;
1231 rtype
= "dynamic-tcpip";
1233 nextstate
= SSH_CHANNEL_OPENING
;
1234 rtype
= "direct-tcpip";
1238 addrlen
= sizeof(addr
);
1239 newsock
= accept(c
->sock
, &addr
, &addrlen
);
1241 error("accept: %.100s", strerror(errno
));
1244 set_nodelay(newsock
);
1245 nc
= channel_new(rtype
, nextstate
, newsock
, newsock
, -1,
1246 c
->local_window_max
, c
->local_maxpacket
, 0, rtype
, 1);
1247 nc
->listening_port
= c
->listening_port
;
1248 nc
->host_port
= c
->host_port
;
1249 strlcpy(nc
->path
, c
->path
, sizeof(nc
->path
));
1251 if (nextstate
== SSH_CHANNEL_DYNAMIC
) {
1253 * do not call the channel_post handler until
1254 * this flag has been reset by a pre-handler.
1255 * otherwise the FD_ISSET calls might overflow
1259 port_open_helper(nc
, rtype
);
1265 * This is the authentication agent socket listening for connections from
1269 channel_post_auth_listener(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1273 struct sockaddr addr
;
1276 if (FD_ISSET(c
->sock
, readset
)) {
1277 addrlen
= sizeof(addr
);
1278 newsock
= accept(c
->sock
, &addr
, &addrlen
);
1280 error("accept from auth socket: %.100s", strerror(errno
));
1283 nc
= channel_new("accepted auth socket",
1284 SSH_CHANNEL_OPENING
, newsock
, newsock
, -1,
1285 c
->local_window_max
, c
->local_maxpacket
,
1286 0, "accepted auth socket", 1);
1288 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1289 packet_put_cstring("auth-agent@openssh.com");
1290 packet_put_int(nc
->self
);
1291 packet_put_int(c
->local_window_max
);
1292 packet_put_int(c
->local_maxpacket
);
1294 packet_start(SSH_SMSG_AGENT_OPEN
);
1295 packet_put_int(nc
->self
);
1302 channel_post_connecting(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1305 socklen_t sz
= sizeof(err
);
1307 if (FD_ISSET(c
->sock
, writeset
)) {
1308 if (getsockopt(c
->sock
, SOL_SOCKET
, SO_ERROR
, &err
, &sz
) < 0) {
1310 error("getsockopt SO_ERROR failed");
1313 debug("channel %d: connected", c
->self
);
1314 c
->type
= SSH_CHANNEL_OPEN
;
1316 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
1317 packet_put_int(c
->remote_id
);
1318 packet_put_int(c
->self
);
1319 packet_put_int(c
->local_window
);
1320 packet_put_int(c
->local_maxpacket
);
1322 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION
);
1323 packet_put_int(c
->remote_id
);
1324 packet_put_int(c
->self
);
1327 debug("channel %d: not connected: %s",
1328 c
->self
, strerror(err
));
1330 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
1331 packet_put_int(c
->remote_id
);
1332 packet_put_int(SSH2_OPEN_CONNECT_FAILED
);
1333 if (!(datafellows
& SSH_BUG_OPENFAILURE
)) {
1334 packet_put_cstring(strerror(err
));
1335 packet_put_cstring("");
1338 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
1339 packet_put_int(c
->remote_id
);
1348 channel_handle_rfd(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1354 FD_ISSET(c
->rfd
, readset
)) {
1355 len
= read(c
->rfd
, buf
, sizeof(buf
));
1356 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
))
1359 debug2("channel %d: read<=0 rfd %d len %d",
1360 c
->self
, c
->rfd
, len
);
1361 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1362 debug2("channel %d: not open", c
->self
);
1365 } else if (compat13
) {
1366 buffer_clear(&c
->output
);
1367 c
->type
= SSH_CHANNEL_INPUT_DRAINING
;
1368 debug2("channel %d: input draining.", c
->self
);
1370 chan_read_failed(c
);
1374 if (c
->input_filter
!= NULL
) {
1375 if (c
->input_filter(c
, buf
, len
) == -1) {
1376 debug2("channel %d: filter stops", c
->self
);
1377 chan_read_failed(c
);
1380 buffer_append(&c
->input
, buf
, len
);
1386 channel_handle_wfd(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1393 /* Send buffered output data to the socket. */
1395 FD_ISSET(c
->wfd
, writeset
) &&
1396 buffer_len(&c
->output
) > 0) {
1397 data
= buffer_ptr(&c
->output
);
1398 dlen
= buffer_len(&c
->output
);
1400 /* XXX: Later AIX versions can't push as much data to tty */
1401 if (compat20
&& c
->wfd_isatty
)
1402 dlen
= MIN(dlen
, 8*1024);
1404 len
= write(c
->wfd
, data
, dlen
);
1405 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
))
1408 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1409 debug2("channel %d: not open", c
->self
);
1412 } else if (compat13
) {
1413 buffer_clear(&c
->output
);
1414 debug2("channel %d: input draining.", c
->self
);
1415 c
->type
= SSH_CHANNEL_INPUT_DRAINING
;
1417 chan_write_failed(c
);
1421 if (compat20
&& c
->isatty
&& dlen
>= 1 && data
[0] != '\r') {
1422 if (tcgetattr(c
->wfd
, &tio
) == 0 &&
1423 !(tio
.c_lflag
& ECHO
) && (tio
.c_lflag
& ICANON
)) {
1425 * Simulate echo to reduce the impact of
1426 * traffic analysis. We need to match the
1427 * size of a SSH2_MSG_CHANNEL_DATA message
1428 * (4 byte channel id + data)
1430 packet_send_ignore(4 + len
);
1434 buffer_consume(&c
->output
, len
);
1435 if (compat20
&& len
> 0) {
1436 c
->local_consumed
+= len
;
1442 channel_handle_efd(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1447 /** XXX handle drain efd, too */
1449 if (c
->extended_usage
== CHAN_EXTENDED_WRITE
&&
1450 FD_ISSET(c
->efd
, writeset
) &&
1451 buffer_len(&c
->extended
) > 0) {
1452 len
= write(c
->efd
, buffer_ptr(&c
->extended
),
1453 buffer_len(&c
->extended
));
1454 debug2("channel %d: written %d to efd %d",
1455 c
->self
, len
, c
->efd
);
1456 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
))
1459 debug2("channel %d: closing write-efd %d",
1461 channel_close_fd(&c
->efd
);
1463 buffer_consume(&c
->extended
, len
);
1464 c
->local_consumed
+= len
;
1466 } else if (c
->extended_usage
== CHAN_EXTENDED_READ
&&
1467 FD_ISSET(c
->efd
, readset
)) {
1468 len
= read(c
->efd
, buf
, sizeof(buf
));
1469 debug2("channel %d: read %d from efd %d",
1470 c
->self
, len
, c
->efd
);
1471 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
))
1474 debug2("channel %d: closing read-efd %d",
1476 channel_close_fd(&c
->efd
);
1478 buffer_append(&c
->extended
, buf
, len
);
1485 channel_check_window(Channel
*c
)
1487 if (c
->type
== SSH_CHANNEL_OPEN
&&
1488 !(c
->flags
& (CHAN_CLOSE_SENT
|CHAN_CLOSE_RCVD
)) &&
1489 c
->local_window
< c
->local_window_max
/2 &&
1490 c
->local_consumed
> 0) {
1491 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1492 packet_put_int(c
->remote_id
);
1493 packet_put_int(c
->local_consumed
);
1495 debug2("channel %d: window %d sent adjust %d",
1496 c
->self
, c
->local_window
,
1498 c
->local_window
+= c
->local_consumed
;
1499 c
->local_consumed
= 0;
1505 channel_post_open(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1509 channel_handle_rfd(c
, readset
, writeset
);
1510 channel_handle_wfd(c
, readset
, writeset
);
1513 channel_handle_efd(c
, readset
, writeset
);
1514 channel_check_window(c
);
1518 channel_post_output_drain_13(Channel
*c
, fd_set
* readset
, fd_set
* writeset
)
1522 /* Send buffered output data to the socket. */
1523 if (FD_ISSET(c
->sock
, writeset
) && buffer_len(&c
->output
) > 0) {
1524 len
= write(c
->sock
, buffer_ptr(&c
->output
),
1525 buffer_len(&c
->output
));
1527 buffer_clear(&c
->output
);
1529 buffer_consume(&c
->output
, len
);
1534 channel_handler_init_20(void)
1536 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open
;
1537 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open
;
1538 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1539 channel_pre
[SSH_CHANNEL_RPORT_LISTENER
] = &channel_pre_listener
;
1540 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1541 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1542 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1543 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1545 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1546 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1547 channel_post
[SSH_CHANNEL_RPORT_LISTENER
] = &channel_post_port_listener
;
1548 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1549 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1550 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1551 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1555 channel_handler_init_13(void)
1557 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open_13
;
1558 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open_13
;
1559 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1560 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1561 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1562 channel_pre
[SSH_CHANNEL_INPUT_DRAINING
] = &channel_pre_input_draining
;
1563 channel_pre
[SSH_CHANNEL_OUTPUT_DRAINING
] = &channel_pre_output_draining
;
1564 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1565 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1567 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1568 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1569 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1570 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1571 channel_post
[SSH_CHANNEL_OUTPUT_DRAINING
] = &channel_post_output_drain_13
;
1572 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1573 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1577 channel_handler_init_15(void)
1579 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open
;
1580 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open
;
1581 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1582 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1583 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1584 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1585 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1587 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1588 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1589 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1590 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1591 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1592 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1596 channel_handler_init(void)
1600 for (i
= 0; i
< SSH_CHANNEL_MAX_TYPE
; i
++) {
1601 channel_pre
[i
] = NULL
;
1602 channel_post
[i
] = NULL
;
1605 channel_handler_init_20();
1607 channel_handler_init_13();
1609 channel_handler_init_15();
1612 /* gc dead channels */
1614 channel_garbage_collect(Channel
*c
)
1618 if (c
->detach_user
!= NULL
) {
1619 if (!chan_is_dead(c
, 0))
1621 debug2("channel %d: gc: notify user", c
->self
);
1622 c
->detach_user(c
->self
, NULL
);
1623 /* if we still have a callback */
1624 if (c
->detach_user
!= NULL
)
1626 debug2("channel %d: gc: user detached", c
->self
);
1628 if (!chan_is_dead(c
, 1))
1630 debug2("channel %d: garbage collecting", c
->self
);
1635 channel_handler(chan_fn
*ftab
[], fd_set
* readset
, fd_set
* writeset
)
1637 static int did_init
= 0;
1642 channel_handler_init();
1645 for (i
= 0; i
< channels_alloc
; i
++) {
1649 if (ftab
[c
->type
] != NULL
)
1650 (*ftab
[c
->type
])(c
, readset
, writeset
);
1651 channel_garbage_collect(c
);
1656 * Allocate/update select bitmasks and add any bits relevant to channels in
1660 channel_prepare_select(fd_set
**readsetp
, fd_set
**writesetp
, int *maxfdp
,
1661 int *nallocp
, int rekeying
)
1666 n
= MAX(*maxfdp
, channel_max_fd
);
1668 sz
= howmany(n
+1, NFDBITS
) * sizeof(fd_mask
);
1669 /* perhaps check sz < nalloc/2 and shrink? */
1670 if (*readsetp
== NULL
|| sz
> *nallocp
) {
1671 *readsetp
= xrealloc(*readsetp
, sz
);
1672 *writesetp
= xrealloc(*writesetp
, sz
);
1676 memset(*readsetp
, 0, sz
);
1677 memset(*writesetp
, 0, sz
);
1680 channel_handler(channel_pre
, *readsetp
, *writesetp
);
1684 * After select, perform any appropriate operations for channels which have
1688 channel_after_select(fd_set
* readset
, fd_set
* writeset
)
1690 channel_handler(channel_post
, readset
, writeset
);
1694 /* If there is data to send to the connection, enqueue some of it now. */
1697 channel_output_poll(void)
1703 for (i
= 0; i
< channels_alloc
; i
++) {
1709 * We are only interested in channels that can have buffered
1713 if (c
->type
!= SSH_CHANNEL_OPEN
&&
1714 c
->type
!= SSH_CHANNEL_INPUT_DRAINING
)
1717 if (c
->type
!= SSH_CHANNEL_OPEN
)
1721 (c
->flags
& (CHAN_CLOSE_SENT
|CHAN_CLOSE_RCVD
))) {
1722 /* XXX is this true? */
1723 debug3("channel %d: will not send data after close", c
->self
);
1727 /* Get the amount of buffered data for this channel. */
1728 if ((c
->istate
== CHAN_INPUT_OPEN
||
1729 c
->istate
== CHAN_INPUT_WAIT_DRAIN
) &&
1730 (len
= buffer_len(&c
->input
)) > 0) {
1732 * Send some data for the other side over the secure
1736 if (len
> c
->remote_window
)
1737 len
= c
->remote_window
;
1738 if (len
> c
->remote_maxpacket
)
1739 len
= c
->remote_maxpacket
;
1741 if (packet_is_interactive()) {
1745 /* Keep the packets at reasonable size. */
1746 if (len
> packet_get_maxsize()/2)
1747 len
= packet_get_maxsize()/2;
1751 packet_start(compat20
?
1752 SSH2_MSG_CHANNEL_DATA
: SSH_MSG_CHANNEL_DATA
);
1753 packet_put_int(c
->remote_id
);
1754 packet_put_string(buffer_ptr(&c
->input
), len
);
1756 buffer_consume(&c
->input
, len
);
1757 c
->remote_window
-= len
;
1759 } else if (c
->istate
== CHAN_INPUT_WAIT_DRAIN
) {
1761 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1763 * input-buffer is empty and read-socket shutdown:
1764 * tell peer, that we will not send more data: send IEOF.
1765 * hack for extended data: delay EOF if EFD still in use.
1767 if (CHANNEL_EFD_INPUT_ACTIVE(c
))
1768 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1769 c
->self
, c
->efd
, buffer_len(&c
->extended
));
1773 /* Send extended data, i.e. stderr */
1775 !(c
->flags
& CHAN_EOF_SENT
) &&
1776 c
->remote_window
> 0 &&
1777 (len
= buffer_len(&c
->extended
)) > 0 &&
1778 c
->extended_usage
== CHAN_EXTENDED_READ
) {
1779 debug2("channel %d: rwin %u elen %u euse %d",
1780 c
->self
, c
->remote_window
, buffer_len(&c
->extended
),
1782 if (len
> c
->remote_window
)
1783 len
= c
->remote_window
;
1784 if (len
> c
->remote_maxpacket
)
1785 len
= c
->remote_maxpacket
;
1786 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
1787 packet_put_int(c
->remote_id
);
1788 packet_put_int(SSH2_EXTENDED_DATA_STDERR
);
1789 packet_put_string(buffer_ptr(&c
->extended
), len
);
1791 buffer_consume(&c
->extended
, len
);
1792 c
->remote_window
-= len
;
1793 debug2("channel %d: sent ext data %d", c
->self
, len
);
1799 /* -- protocol input */
1802 channel_input_data(int type
, u_int32_t seq
, void *ctxt
)
1809 /* Get the channel number and verify it. */
1810 id
= packet_get_int();
1811 c
= channel_lookup(id
);
1813 packet_disconnect("Received data for nonexistent channel %d.", id
);
1815 /* Ignore any data for non-open channels (might happen on close) */
1816 if (c
->type
!= SSH_CHANNEL_OPEN
&&
1817 c
->type
!= SSH_CHANNEL_X11_OPEN
)
1821 data
= packet_get_string(&data_len
);
1824 * Ignore data for protocol > 1.3 if output end is no longer open.
1825 * For protocol 2 the sending side is reducing its window as it sends
1826 * data, so we must 'fake' consumption of the data in order to ensure
1827 * that window updates are sent back. Otherwise the connection might
1830 if (!compat13
&& c
->ostate
!= CHAN_OUTPUT_OPEN
) {
1832 c
->local_window
-= data_len
;
1833 c
->local_consumed
+= data_len
;
1840 if (data_len
> c
->local_maxpacket
) {
1841 logit("channel %d: rcvd big packet %d, maxpack %d",
1842 c
->self
, data_len
, c
->local_maxpacket
);
1844 if (data_len
> c
->local_window
) {
1845 logit("channel %d: rcvd too much data %d, win %d",
1846 c
->self
, data_len
, c
->local_window
);
1850 c
->local_window
-= data_len
;
1853 buffer_append(&c
->output
, data
, data_len
);
1858 channel_input_extended_data(int type
, u_int32_t seq
, void *ctxt
)
1862 u_int data_len
, tcode
;
1865 /* Get the channel number and verify it. */
1866 id
= packet_get_int();
1867 c
= channel_lookup(id
);
1870 packet_disconnect("Received extended_data for bad channel %d.", id
);
1871 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1872 logit("channel %d: ext data for non open", id
);
1875 if (c
->flags
& CHAN_EOF_RCVD
) {
1876 if (datafellows
& SSH_BUG_EXTEOF
)
1877 debug("channel %d: accepting ext data after eof", id
);
1879 packet_disconnect("Received extended_data after EOF "
1880 "on channel %d.", id
);
1882 tcode
= packet_get_int();
1884 c
->extended_usage
!= CHAN_EXTENDED_WRITE
||
1885 tcode
!= SSH2_EXTENDED_DATA_STDERR
) {
1886 logit("channel %d: bad ext data", c
->self
);
1889 data
= packet_get_string(&data_len
);
1891 if (data_len
> c
->local_window
) {
1892 logit("channel %d: rcvd too much extended_data %d, win %d",
1893 c
->self
, data_len
, c
->local_window
);
1897 debug2("channel %d: rcvd ext data %d", c
->self
, data_len
);
1898 c
->local_window
-= data_len
;
1899 buffer_append(&c
->extended
, data
, data_len
);
1904 channel_input_ieof(int type
, u_int32_t seq
, void *ctxt
)
1909 id
= packet_get_int();
1911 c
= channel_lookup(id
);
1913 packet_disconnect("Received ieof for nonexistent channel %d.", id
);
1916 /* XXX force input close */
1917 if (c
->force_drain
&& c
->istate
== CHAN_INPUT_OPEN
) {
1918 debug("channel %d: FORCE input drain", c
->self
);
1919 c
->istate
= CHAN_INPUT_WAIT_DRAIN
;
1920 if (buffer_len(&c
->input
) == 0)
1927 channel_input_close(int type
, u_int32_t seq
, void *ctxt
)
1932 id
= packet_get_int();
1934 c
= channel_lookup(id
);
1936 packet_disconnect("Received close for nonexistent channel %d.", id
);
1939 * Send a confirmation that we have closed the channel and no more
1940 * data is coming for it.
1942 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION
);
1943 packet_put_int(c
->remote_id
);
1947 * If the channel is in closed state, we have sent a close request,
1948 * and the other side will eventually respond with a confirmation.
1949 * Thus, we cannot free the channel here, because then there would be
1950 * no-one to receive the confirmation. The channel gets freed when
1951 * the confirmation arrives.
1953 if (c
->type
!= SSH_CHANNEL_CLOSED
) {
1955 * Not a closed channel - mark it as draining, which will
1956 * cause it to be freed later.
1958 buffer_clear(&c
->input
);
1959 c
->type
= SSH_CHANNEL_OUTPUT_DRAINING
;
1963 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1965 channel_input_oclose(int type
, u_int32_t seq
, void *ctxt
)
1967 int id
= packet_get_int();
1968 Channel
*c
= channel_lookup(id
);
1972 packet_disconnect("Received oclose for nonexistent channel %d.", id
);
1973 chan_rcvd_oclose(c
);
1977 channel_input_close_confirmation(int type
, u_int32_t seq
, void *ctxt
)
1979 int id
= packet_get_int();
1980 Channel
*c
= channel_lookup(id
);
1984 packet_disconnect("Received close confirmation for "
1985 "out-of-range channel %d.", id
);
1986 if (c
->type
!= SSH_CHANNEL_CLOSED
)
1987 packet_disconnect("Received close confirmation for "
1988 "non-closed channel %d (type %d).", id
, c
->type
);
1993 channel_input_open_confirmation(int type
, u_int32_t seq
, void *ctxt
)
1998 id
= packet_get_int();
1999 c
= channel_lookup(id
);
2001 if (c
==NULL
|| c
->type
!= SSH_CHANNEL_OPENING
)
2002 packet_disconnect("Received open confirmation for "
2003 "non-opening channel %d.", id
);
2004 remote_id
= packet_get_int();
2005 /* Record the remote channel number and mark that the channel is now open. */
2006 c
->remote_id
= remote_id
;
2007 c
->type
= SSH_CHANNEL_OPEN
;
2010 c
->remote_window
= packet_get_int();
2011 c
->remote_maxpacket
= packet_get_int();
2013 debug2("callback start");
2014 c
->confirm(c
->self
, NULL
);
2015 debug2("callback done");
2017 debug2("channel %d: open confirm rwindow %u rmax %u", c
->self
,
2018 c
->remote_window
, c
->remote_maxpacket
);
2024 reason2txt(int reason
)
2027 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED
:
2028 return "administratively prohibited";
2029 case SSH2_OPEN_CONNECT_FAILED
:
2030 return "connect failed";
2031 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE
:
2032 return "unknown channel type";
2033 case SSH2_OPEN_RESOURCE_SHORTAGE
:
2034 return "resource shortage";
2036 return "unknown reason";
2040 channel_input_open_failure(int type
, u_int32_t seq
, void *ctxt
)
2043 char *msg
= NULL
, *lang
= NULL
;
2046 id
= packet_get_int();
2047 c
= channel_lookup(id
);
2049 if (c
==NULL
|| c
->type
!= SSH_CHANNEL_OPENING
)
2050 packet_disconnect("Received open failure for "
2051 "non-opening channel %d.", id
);
2053 reason
= packet_get_int();
2054 if (!(datafellows
& SSH_BUG_OPENFAILURE
)) {
2055 msg
= packet_get_string(NULL
);
2056 lang
= packet_get_string(NULL
);
2058 logit("channel %d: open failed: %s%s%s", id
,
2059 reason2txt(reason
), msg
? ": ": "", msg
? msg
: "");
2066 /* Free the channel. This will also close the socket. */
2071 channel_input_window_adjust(int type
, u_int32_t seq
, void *ctxt
)
2080 /* Get the channel number and verify it. */
2081 id
= packet_get_int();
2082 c
= channel_lookup(id
);
2084 if (c
== NULL
|| c
->type
!= SSH_CHANNEL_OPEN
) {
2085 logit("Received window adjust for "
2086 "non-open channel %d.", id
);
2089 adjust
= packet_get_int();
2091 debug2("channel %d: rcvd adjust %u", id
, adjust
);
2092 c
->remote_window
+= adjust
;
2096 channel_input_port_open(int type
, u_int32_t seq
, void *ctxt
)
2100 char *host
, *originator_string
;
2101 int remote_id
, sock
= -1;
2103 remote_id
= packet_get_int();
2104 host
= packet_get_string(NULL
);
2105 host_port
= packet_get_int();
2107 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN
) {
2108 originator_string
= packet_get_string(NULL
);
2110 originator_string
= xstrdup("unknown (remote did not supply name)");
2113 sock
= channel_connect_to(host
, host_port
);
2115 c
= channel_new("connected socket",
2116 SSH_CHANNEL_CONNECTING
, sock
, sock
, -1, 0, 0, 0,
2117 originator_string
, 1);
2118 c
->remote_id
= remote_id
;
2120 xfree(originator_string
);
2122 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
2123 packet_put_int(remote_id
);
2130 /* -- tcp forwarding */
2133 channel_set_af(int af
)
2139 channel_setup_fwd_listener(int type
, const char *listen_addr
, u_short listen_port
,
2140 const char *host_to_connect
, u_short port_to_connect
, int gateway_ports
)
2143 int success
, sock
, on
= 1;
2144 struct addrinfo hints
, *ai
, *aitop
;
2146 char ntop
[NI_MAXHOST
], strport
[NI_MAXSERV
];
2149 host
= (type
== SSH_CHANNEL_RPORT_LISTENER
) ?
2150 listen_addr
: host_to_connect
;
2153 error("No forward host name.");
2156 if (strlen(host
) > SSH_CHANNEL_PATH_LEN
- 1) {
2157 error("Forward host name too long.");
2162 * getaddrinfo returns a loopback address if the hostname is
2163 * set to NULL and hints.ai_flags is not AI_PASSIVE
2165 memset(&hints
, 0, sizeof(hints
));
2166 hints
.ai_family
= IPv4or6
;
2167 hints
.ai_flags
= gateway_ports
? AI_PASSIVE
: 0;
2168 hints
.ai_socktype
= SOCK_STREAM
;
2169 snprintf(strport
, sizeof strport
, "%d", listen_port
);
2170 if (getaddrinfo(NULL
, strport
, &hints
, &aitop
) != 0)
2171 packet_disconnect("getaddrinfo: fatal error");
2173 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
2174 if (ai
->ai_family
!= AF_INET
&& ai
->ai_family
!= AF_INET6
)
2176 if (getnameinfo(ai
->ai_addr
, ai
->ai_addrlen
, ntop
, sizeof(ntop
),
2177 strport
, sizeof(strport
), NI_NUMERICHOST
|NI_NUMERICSERV
) != 0) {
2178 error("channel_setup_fwd_listener: getnameinfo failed");
2181 /* Create a port to listen for the host. */
2182 sock
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
2184 /* this is no error since kernel may not support ipv6 */
2185 verbose("socket: %.100s", strerror(errno
));
2189 * Set socket options.
2190 * Allow local port reuse in TIME_WAIT.
2192 if (setsockopt(sock
, SOL_SOCKET
, SO_REUSEADDR
, &on
,
2194 error("setsockopt SO_REUSEADDR: %s", strerror(errno
));
2196 debug("Local forwarding listening on %s port %s.", ntop
, strport
);
2198 /* Bind the socket to the address. */
2199 if (bind(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
2200 /* address can be in use ipv6 address is already bound */
2202 error("bind: %.100s", strerror(errno
));
2204 verbose("bind: %.100s", strerror(errno
));
2209 /* Start listening for connections on the socket. */
2210 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
2211 error("listen: %.100s", strerror(errno
));
2215 /* Allocate a channel number for the socket. */
2216 c
= channel_new("port listener", type
, sock
, sock
, -1,
2217 CHAN_TCP_WINDOW_DEFAULT
, CHAN_TCP_PACKET_DEFAULT
,
2218 0, "port listener", 1);
2219 strlcpy(c
->path
, host
, sizeof(c
->path
));
2220 c
->host_port
= port_to_connect
;
2221 c
->listening_port
= listen_port
;
2225 error("channel_setup_fwd_listener: cannot listen to port: %d",
2227 freeaddrinfo(aitop
);
2231 /* protocol local port fwd, used by ssh (and sshd in v1) */
2233 channel_setup_local_fwd_listener(u_short listen_port
,
2234 const char *host_to_connect
, u_short port_to_connect
, int gateway_ports
)
2236 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER
,
2237 NULL
, listen_port
, host_to_connect
, port_to_connect
, gateway_ports
);
2240 /* protocol v2 remote port fwd, used by sshd */
2242 channel_setup_remote_fwd_listener(const char *listen_address
,
2243 u_short listen_port
, int gateway_ports
)
2245 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER
,
2246 listen_address
, listen_port
, NULL
, 0, gateway_ports
);
2250 * Initiate forwarding of connections to port "port" on remote host through
2251 * the secure channel to host:port from local side.
2255 channel_request_remote_forwarding(u_short listen_port
,
2256 const char *host_to_connect
, u_short port_to_connect
)
2258 int type
, success
= 0;
2260 /* Record locally that connection to this host/port is permitted. */
2261 if (num_permitted_opens
>= SSH_MAX_FORWARDS_PER_DIRECTION
)
2262 fatal("channel_request_remote_forwarding: too many forwards");
2264 /* Send the forward request to the remote side. */
2266 const char *address_to_bind
= "0.0.0.0";
2267 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
2268 packet_put_cstring("tcpip-forward");
2269 packet_put_char(1); /* boolean: want reply */
2270 packet_put_cstring(address_to_bind
);
2271 packet_put_int(listen_port
);
2273 packet_write_wait();
2274 /* Assume that server accepts the request */
2277 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST
);
2278 packet_put_int(listen_port
);
2279 packet_put_cstring(host_to_connect
);
2280 packet_put_int(port_to_connect
);
2282 packet_write_wait();
2284 /* Wait for response from the remote side. */
2285 type
= packet_read();
2287 case SSH_SMSG_SUCCESS
:
2290 case SSH_SMSG_FAILURE
:
2291 logit("Warning: Server denied remote port forwarding.");
2294 /* Unknown packet */
2295 packet_disconnect("Protocol error for port forward request:"
2296 "received packet type %d.", type
);
2300 permitted_opens
[num_permitted_opens
].host_to_connect
= xstrdup(host_to_connect
);
2301 permitted_opens
[num_permitted_opens
].port_to_connect
= port_to_connect
;
2302 permitted_opens
[num_permitted_opens
].listen_port
= listen_port
;
2303 num_permitted_opens
++;
2308 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2309 * listening for the port, and sends back a success reply (or disconnect
2310 * message if there was an error). This never returns if there was an error.
2314 channel_input_port_forward_request(int is_root
, int gateway_ports
)
2316 u_short port
, host_port
;
2319 /* Get arguments from the packet. */
2320 port
= packet_get_int();
2321 hostname
= packet_get_string(NULL
);
2322 host_port
= packet_get_int();
2326 * Check that an unprivileged user is not trying to forward a
2329 if (port
< IPPORT_RESERVED
&& !is_root
)
2331 "Requested forwarding of port %d but user is not root.",
2334 packet_disconnect("Dynamic forwarding denied.");
2337 /* Initiate forwarding */
2338 channel_setup_local_fwd_listener(port
, hostname
, host_port
, gateway_ports
);
2340 /* Free the argument string. */
2345 * Permits opening to any host/port if permitted_opens[] is empty. This is
2346 * usually called by the server, because the user could connect to any port
2347 * anyway, and the server has no way to know but to trust the client anyway.
2350 channel_permit_all_opens(void)
2352 if (num_permitted_opens
== 0)
2353 all_opens_permitted
= 1;
2357 channel_add_permitted_opens(char *host
, int port
)
2359 if (num_permitted_opens
>= SSH_MAX_FORWARDS_PER_DIRECTION
)
2360 fatal("channel_request_remote_forwarding: too many forwards");
2361 debug("allow port forwarding to host %s port %d", host
, port
);
2363 permitted_opens
[num_permitted_opens
].host_to_connect
= xstrdup(host
);
2364 permitted_opens
[num_permitted_opens
].port_to_connect
= port
;
2365 num_permitted_opens
++;
2367 all_opens_permitted
= 0;
2371 channel_clear_permitted_opens(void)
2375 for (i
= 0; i
< num_permitted_opens
; i
++)
2376 xfree(permitted_opens
[i
].host_to_connect
);
2377 num_permitted_opens
= 0;
2382 /* return socket to remote host, port */
2384 connect_to(const char *host
, u_short port
)
2386 struct addrinfo hints
, *ai
, *aitop
;
2387 char ntop
[NI_MAXHOST
], strport
[NI_MAXSERV
];
2391 memset(&hints
, 0, sizeof(hints
));
2392 hints
.ai_family
= IPv4or6
;
2393 hints
.ai_socktype
= SOCK_STREAM
;
2394 snprintf(strport
, sizeof strport
, "%d", port
);
2395 if ((gaierr
= getaddrinfo(host
, strport
, &hints
, &aitop
)) != 0) {
2396 error("connect_to %.100s: unknown host (%s)", host
,
2397 gai_strerror(gaierr
));
2400 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
2401 if (ai
->ai_family
!= AF_INET
&& ai
->ai_family
!= AF_INET6
)
2403 if (getnameinfo(ai
->ai_addr
, ai
->ai_addrlen
, ntop
, sizeof(ntop
),
2404 strport
, sizeof(strport
), NI_NUMERICHOST
|NI_NUMERICSERV
) != 0) {
2405 error("connect_to: getnameinfo failed");
2408 sock
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
2410 if (ai
->ai_next
== NULL
)
2411 error("socket: %.100s", strerror(errno
));
2413 verbose("socket: %.100s", strerror(errno
));
2416 if (fcntl(sock
, F_SETFL
, O_NONBLOCK
) < 0)
2417 fatal("connect_to: F_SETFL: %s", strerror(errno
));
2418 if (connect(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0 &&
2419 errno
!= EINPROGRESS
) {
2420 error("connect_to %.100s port %s: %.100s", ntop
, strport
,
2423 continue; /* fail -- try next */
2425 break; /* success */
2428 freeaddrinfo(aitop
);
2430 error("connect_to %.100s port %d: failed.", host
, port
);
2439 channel_connect_by_listen_address(u_short listen_port
)
2443 for (i
= 0; i
< num_permitted_opens
; i
++)
2444 if (permitted_opens
[i
].listen_port
== listen_port
)
2446 permitted_opens
[i
].host_to_connect
,
2447 permitted_opens
[i
].port_to_connect
);
2448 error("WARNING: Server requests forwarding for unknown listen_port %d",
2453 /* Check if connecting to that port is permitted and connect. */
2455 channel_connect_to(const char *host
, u_short port
)
2459 permit
= all_opens_permitted
;
2461 for (i
= 0; i
< num_permitted_opens
; i
++)
2462 if (permitted_opens
[i
].port_to_connect
== port
&&
2463 strcmp(permitted_opens
[i
].host_to_connect
, host
) == 0)
2468 logit("Received request to connect to host %.100s port %d, "
2469 "but the request was denied.", host
, port
);
2472 return connect_to(host
, port
);
2475 /* -- X11 forwarding */
2478 * Creates an internet domain socket for listening for X11 connections.
2479 * Returns 0 and a suitable display number for the DISPLAY variable
2480 * stored in display_numberp , or -1 if an error occurs.
2483 x11_create_display_inet(int x11_display_offset
, int x11_use_localhost
,
2484 int single_connection
, u_int
*display_numberp
)
2487 int display_number
, sock
;
2489 struct addrinfo hints
, *ai
, *aitop
;
2490 char strport
[NI_MAXSERV
];
2491 int gaierr
, n
, num_socks
= 0, socks
[NUM_SOCKS
];
2493 for (display_number
= x11_display_offset
;
2494 display_number
< MAX_DISPLAYS
;
2496 port
= 6000 + display_number
;
2497 memset(&hints
, 0, sizeof(hints
));
2498 hints
.ai_family
= IPv4or6
;
2499 hints
.ai_flags
= x11_use_localhost
? 0: AI_PASSIVE
;
2500 hints
.ai_socktype
= SOCK_STREAM
;
2501 snprintf(strport
, sizeof strport
, "%d", port
);
2502 if ((gaierr
= getaddrinfo(NULL
, strport
, &hints
, &aitop
)) != 0) {
2503 error("getaddrinfo: %.100s", gai_strerror(gaierr
));
2506 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
2507 if (ai
->ai_family
!= AF_INET
&& ai
->ai_family
!= AF_INET6
)
2509 sock
= socket(ai
->ai_family
, ai
->ai_socktype
,
2512 if ((errno
!= EINVAL
) && (errno
!= EAFNOSUPPORT
)) {
2513 error("socket: %.100s", strerror(errno
));
2516 debug("x11_create_display_inet: Socket family %d not supported",
2522 if (ai
->ai_family
== AF_INET6
) {
2524 if (setsockopt(sock
, IPPROTO_IPV6
, IPV6_V6ONLY
, &on
, sizeof(on
)) < 0)
2525 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno
));
2528 if (bind(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
2529 debug2("bind port %d: %.100s", port
, strerror(errno
));
2535 for (n
= 0; n
< num_socks
; n
++) {
2541 socks
[num_socks
++] = sock
;
2542 #ifndef DONT_TRY_OTHER_AF
2543 if (num_socks
== NUM_SOCKS
)
2546 if (x11_use_localhost
) {
2547 if (num_socks
== NUM_SOCKS
)
2554 freeaddrinfo(aitop
);
2558 if (display_number
>= MAX_DISPLAYS
) {
2559 error("Failed to allocate internet-domain X11 display socket.");
2562 /* Start listening for connections on the socket. */
2563 for (n
= 0; n
< num_socks
; n
++) {
2565 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
2566 error("listen: %.100s", strerror(errno
));
2572 /* Allocate a channel for each socket. */
2573 for (n
= 0; n
< num_socks
; n
++) {
2575 nc
= channel_new("x11 listener",
2576 SSH_CHANNEL_X11_LISTENER
, sock
, sock
, -1,
2577 CHAN_X11_WINDOW_DEFAULT
, CHAN_X11_PACKET_DEFAULT
,
2578 0, "X11 inet listener", 1);
2579 nc
->single_connection
= single_connection
;
2582 /* Return the display number for the DISPLAY environment variable. */
2583 *display_numberp
= display_number
;
2588 connect_local_xsocket(u_int dnr
)
2591 struct sockaddr_un addr
;
2593 sock
= socket(AF_UNIX
, SOCK_STREAM
, 0);
2595 error("socket: %.100s", strerror(errno
));
2596 memset(&addr
, 0, sizeof(addr
));
2597 addr
.sun_family
= AF_UNIX
;
2598 snprintf(addr
.sun_path
, sizeof addr
.sun_path
, _PATH_UNIX_X
, dnr
);
2599 if (connect(sock
, (struct sockaddr
*) & addr
, sizeof(addr
)) == 0)
2602 error("connect %.100s: %.100s", addr
.sun_path
, strerror(errno
));
2607 x11_connect_display(void)
2609 int display_number
, sock
= 0;
2610 const char *display
;
2611 char buf
[1024], *cp
;
2612 struct addrinfo hints
, *ai
, *aitop
;
2613 char strport
[NI_MAXSERV
];
2616 /* Try to open a socket for the local X server. */
2617 display
= getenv("DISPLAY");
2619 error("DISPLAY not set.");
2623 * Now we decode the value of the DISPLAY variable and make a
2624 * connection to the real X server.
2628 * Check if it is a unix domain socket. Unix domain displays are in
2629 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2631 if (strncmp(display
, "unix:", 5) == 0 ||
2632 display
[0] == ':') {
2633 /* Connect to the unix domain socket. */
2634 if (sscanf(strrchr(display
, ':') + 1, "%d", &display_number
) != 1) {
2635 error("Could not parse display number from DISPLAY: %.100s",
2639 /* Create a socket. */
2640 sock
= connect_local_xsocket(display_number
);
2644 /* OK, we now have a connection to the display. */
2648 * Connect to an inet socket. The DISPLAY value is supposedly
2649 * hostname:d[.s], where hostname may also be numeric IP address.
2651 strlcpy(buf
, display
, sizeof(buf
));
2652 cp
= strchr(buf
, ':');
2654 error("Could not find ':' in DISPLAY: %.100s", display
);
2658 /* buf now contains the host name. But first we parse the display number. */
2659 if (sscanf(cp
+ 1, "%d", &display_number
) != 1) {
2660 error("Could not parse display number from DISPLAY: %.100s",
2665 /* Look up the host address */
2666 memset(&hints
, 0, sizeof(hints
));
2667 hints
.ai_family
= IPv4or6
;
2668 hints
.ai_socktype
= SOCK_STREAM
;
2669 snprintf(strport
, sizeof strport
, "%d", 6000 + display_number
);
2670 if ((gaierr
= getaddrinfo(buf
, strport
, &hints
, &aitop
)) != 0) {
2671 error("%.100s: unknown host. (%s)", buf
, gai_strerror(gaierr
));
2674 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
2675 /* Create a socket. */
2676 sock
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
2678 debug2("socket: %.100s", strerror(errno
));
2681 /* Connect it to the display. */
2682 if (connect(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
2683 debug2("connect %.100s port %d: %.100s", buf
,
2684 6000 + display_number
, strerror(errno
));
2691 freeaddrinfo(aitop
);
2693 error("connect %.100s port %d: %.100s", buf
, 6000 + display_number
,
2702 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2703 * the remote channel number. We should do whatever we want, and respond
2704 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2708 x11_input_open(int type
, u_int32_t seq
, void *ctxt
)
2711 int remote_id
, sock
= 0;
2714 debug("Received X11 open request.");
2716 remote_id
= packet_get_int();
2718 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN
) {
2719 remote_host
= packet_get_string(NULL
);
2721 remote_host
= xstrdup("unknown (remote did not supply name)");
2725 /* Obtain a connection to the real X display. */
2726 sock
= x11_connect_display();
2728 /* Allocate a channel for this connection. */
2729 c
= channel_new("connected x11 socket",
2730 SSH_CHANNEL_X11_OPEN
, sock
, sock
, -1, 0, 0, 0,
2732 c
->remote_id
= remote_id
;
2737 /* Send refusal to the remote host. */
2738 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
2739 packet_put_int(remote_id
);
2741 /* Send a confirmation to the remote host. */
2742 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION
);
2743 packet_put_int(remote_id
);
2744 packet_put_int(c
->self
);
2749 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2751 deny_input_open(int type
, u_int32_t seq
, void *ctxt
)
2753 int rchan
= packet_get_int();
2756 case SSH_SMSG_AGENT_OPEN
:
2757 error("Warning: ssh server tried agent forwarding.");
2759 case SSH_SMSG_X11_OPEN
:
2760 error("Warning: ssh server tried X11 forwarding.");
2763 error("deny_input_open: type %d", type
);
2766 error("Warning: this is probably a break in attempt by a malicious server.");
2767 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
2768 packet_put_int(rchan
);
2773 * Requests forwarding of X11 connections, generates fake authentication
2774 * data, and enables authentication spoofing.
2775 * This should be called in the client only.
2778 x11_request_forwarding_with_spoofing(int client_session_id
,
2779 const char *proto
, const char *data
)
2781 u_int data_len
= (u_int
) strlen(data
) / 2;
2782 u_int i
, value
, len
;
2788 cp
= getenv("DISPLAY");
2790 cp
= strchr(cp
, ':');
2792 cp
= strchr(cp
, '.');
2794 screen_number
= atoi(cp
+ 1);
2798 /* Save protocol name. */
2799 x11_saved_proto
= xstrdup(proto
);
2802 * Extract real authentication data and generate fake data of the
2805 x11_saved_data
= xmalloc(data_len
);
2806 x11_fake_data
= xmalloc(data_len
);
2807 for (i
= 0; i
< data_len
; i
++) {
2808 if (sscanf(data
+ 2 * i
, "%2x", &value
) != 1)
2809 fatal("x11_request_forwarding: bad authentication data: %.100s", data
);
2811 rand
= arc4random();
2812 x11_saved_data
[i
] = value
;
2813 x11_fake_data
[i
] = rand
& 0xff;
2816 x11_saved_data_len
= data_len
;
2817 x11_fake_data_len
= data_len
;
2819 /* Convert the fake data into hex. */
2820 len
= 2 * data_len
+ 1;
2821 new_data
= xmalloc(len
);
2822 for (i
= 0; i
< data_len
; i
++)
2823 snprintf(new_data
+ 2 * i
, len
- 2 * i
,
2824 "%02x", (u_char
) x11_fake_data
[i
]);
2826 /* Send the request packet. */
2828 channel_request_start(client_session_id
, "x11-req", 0);
2829 packet_put_char(0); /* XXX bool single connection */
2831 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING
);
2833 packet_put_cstring(proto
);
2834 packet_put_cstring(new_data
);
2835 packet_put_int(screen_number
);
2837 packet_write_wait();
2842 /* -- agent forwarding */
2844 /* Sends a message to the server to request authentication fd forwarding. */
2847 auth_request_forwarding(void)
2849 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING
);
2851 packet_write_wait();