1 /* $OpenBSD: channels.c,v 1.286 2008/07/16 11:52:19 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * This file contains functions for generic socket connection forwarding.
7 * There is also code for initiating connection forwarding for X11 connections,
8 * arbitrary tcp/ip connections, and the authentication agent connection.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 support added by Markus Friedl.
17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Copyright (c) 1999 Dug Song. All rights reserved.
19 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 #include <sys/types.h>
45 #include <sys/ioctl.h>
47 #include <sys/socket.h>
48 #ifdef HAVE_SYS_TIME_H
49 # include <sys/time.h>
52 #include <netinet/in.h>
53 #include <arpa/inet.h>
64 #include "openbsd-compat/sys-queue.h"
78 #include "pathnames.h"
83 * Pointer to an array containing all allocated channels. The array is
84 * dynamically extended as needed.
86 static Channel
**channels
= NULL
;
89 * Size of the channel array. All slots of the array must always be
90 * initialized (at least the type field); unused slots set to NULL
92 static u_int channels_alloc
= 0;
95 * Maximum file descriptor value used in any of the channels. This is
96 * updated in channel_new.
98 static int channel_max_fd
= 0;
101 /* -- tcp forwarding */
104 * Data structure for storing which hosts are permitted for forward requests.
105 * The local sides of any remote forwards are stored in this array to prevent
106 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
107 * network (which might be behind a firewall).
110 char *host_to_connect
; /* Connect to 'host'. */
111 u_short port_to_connect
; /* Connect to 'port'. */
112 u_short listen_port
; /* Remote side should listen port number. */
115 /* List of all permitted host/port pairs to connect by the user. */
116 static ForwardPermission permitted_opens
[SSH_MAX_FORWARDS_PER_DIRECTION
];
118 /* List of all permitted host/port pairs to connect by the admin. */
119 static ForwardPermission permitted_adm_opens
[SSH_MAX_FORWARDS_PER_DIRECTION
];
121 /* Number of permitted host/port pairs in the array permitted by the user. */
122 static int num_permitted_opens
= 0;
124 /* Number of permitted host/port pair in the array permitted by the admin. */
125 static int num_adm_permitted_opens
= 0;
128 * If this is true, all opens are permitted. This is the case on the server
129 * on which we have to trust the client anyway, and the user could do
130 * anything after logging in anyway.
132 static int all_opens_permitted
= 0;
135 /* -- X11 forwarding */
137 /* Maximum number of fake X11 displays to try. */
138 #define MAX_DISPLAYS 1000
140 /* Saved X11 local (client) display. */
141 static char *x11_saved_display
= NULL
;
143 /* Saved X11 authentication protocol name. */
144 static char *x11_saved_proto
= NULL
;
146 /* Saved X11 authentication data. This is the real data. */
147 static char *x11_saved_data
= NULL
;
148 static u_int x11_saved_data_len
= 0;
151 * Fake X11 authentication data. This is what the server will be sending us;
152 * we should replace any occurrences of this by the real data.
154 static u_char
*x11_fake_data
= NULL
;
155 static u_int x11_fake_data_len
;
158 /* -- agent forwarding */
162 /* AF_UNSPEC or AF_INET or AF_INET6 */
163 static int IPv4or6
= AF_UNSPEC
;
166 static void port_open_helper(Channel
*c
, char *rtype
);
168 /* non-blocking connect helpers */
169 static int connect_next(struct channel_connect
*);
170 static void channel_connect_ctx_free(struct channel_connect
*);
172 /* -- channel core */
175 channel_by_id(int id
)
179 if (id
< 0 || (u_int
)id
>= channels_alloc
) {
180 logit("channel_by_id: %d: bad id", id
);
185 logit("channel_by_id: %d: bad id: channel free", id
);
192 * Returns the channel if it is allowed to receive protocol messages.
193 * Private channels, like listening sockets, may not receive messages.
196 channel_lookup(int id
)
200 if ((c
= channel_by_id(id
)) == NULL
)
204 case SSH_CHANNEL_X11_OPEN
:
205 case SSH_CHANNEL_LARVAL
:
206 case SSH_CHANNEL_CONNECTING
:
207 case SSH_CHANNEL_DYNAMIC
:
208 case SSH_CHANNEL_OPENING
:
209 case SSH_CHANNEL_OPEN
:
210 case SSH_CHANNEL_INPUT_DRAINING
:
211 case SSH_CHANNEL_OUTPUT_DRAINING
:
214 logit("Non-public channel %d, type %d.", id
, c
->type
);
219 * Register filedescriptors for a channel, used when allocating a channel or
220 * when the channel consumer/producer is ready, e.g. shell exec'd
223 channel_register_fds(Channel
*c
, int rfd
, int wfd
, int efd
,
224 int extusage
, int nonblock
, int is_tty
)
226 /* Update the maximum file descriptor value. */
227 channel_max_fd
= MAX(channel_max_fd
, rfd
);
228 channel_max_fd
= MAX(channel_max_fd
, wfd
);
229 channel_max_fd
= MAX(channel_max_fd
, efd
);
231 /* XXX set close-on-exec -markus */
235 c
->sock
= (rfd
== wfd
) ? rfd
: -1;
236 c
->ctl_fd
= -1; /* XXX: set elsewhere */
238 c
->extended_usage
= extusage
;
240 if ((c
->isatty
= is_tty
) != 0)
241 debug2("channel %d: rfd %d isatty", c
->self
, c
->rfd
);
242 c
->wfd_isatty
= is_tty
|| isatty(c
->wfd
);
244 /* enable nonblocking mode */
256 * Allocate a new channel object and set its type and socket. This will cause
257 * remote_name to be freed.
260 channel_new(char *ctype
, int type
, int rfd
, int wfd
, int efd
,
261 u_int window
, u_int maxpack
, int extusage
, char *remote_name
, int nonblock
)
267 /* Do initial allocation if this is the first call. */
268 if (channels_alloc
== 0) {
270 channels
= xcalloc(channels_alloc
, sizeof(Channel
*));
271 for (i
= 0; i
< channels_alloc
; i
++)
274 /* Try to find a free slot where to put the new channel. */
275 for (found
= -1, i
= 0; i
< channels_alloc
; i
++)
276 if (channels
[i
] == NULL
) {
277 /* Found a free slot. */
282 /* There are no free slots. Take last+1 slot and expand the array. */
283 found
= channels_alloc
;
284 if (channels_alloc
> 10000)
285 fatal("channel_new: internal error: channels_alloc %d "
286 "too big.", channels_alloc
);
287 channels
= xrealloc(channels
, channels_alloc
+ 10,
289 channels_alloc
+= 10;
290 debug2("channel: expanding %d", channels_alloc
);
291 for (i
= found
; i
< channels_alloc
; i
++)
294 /* Initialize and return new channel. */
295 c
= channels
[found
] = xcalloc(1, sizeof(Channel
));
296 buffer_init(&c
->input
);
297 buffer_init(&c
->output
);
298 buffer_init(&c
->extended
);
299 c
->ostate
= CHAN_OUTPUT_OPEN
;
300 c
->istate
= CHAN_INPUT_OPEN
;
302 channel_register_fds(c
, rfd
, wfd
, efd
, extusage
, nonblock
, 0);
306 c
->local_window
= window
;
307 c
->local_window_max
= window
;
308 c
->local_consumed
= 0;
309 c
->local_maxpacket
= maxpack
;
311 c
->remote_name
= xstrdup(remote_name
);
312 c
->remote_window
= 0;
313 c
->remote_maxpacket
= 0;
315 c
->single_connection
= 0;
316 c
->detach_user
= NULL
;
318 c
->open_confirm
= NULL
;
319 c
->open_confirm_ctx
= NULL
;
320 c
->input_filter
= NULL
;
321 c
->output_filter
= NULL
;
322 c
->filter_ctx
= NULL
;
323 c
->filter_cleanup
= NULL
;
324 TAILQ_INIT(&c
->status_confirms
);
325 debug("channel %d: new [%s]", found
, remote_name
);
330 channel_find_maxfd(void)
336 for (i
= 0; i
< channels_alloc
; i
++) {
339 max
= MAX(max
, c
->rfd
);
340 max
= MAX(max
, c
->wfd
);
341 max
= MAX(max
, c
->efd
);
348 channel_close_fd(int *fdp
)
350 int ret
= 0, fd
= *fdp
;
355 if (fd
== channel_max_fd
)
356 channel_max_fd
= channel_find_maxfd();
361 /* Close all channel fd/socket. */
363 channel_close_fds(Channel
*c
)
365 debug3("channel %d: close_fds r %d w %d e %d c %d",
366 c
->self
, c
->rfd
, c
->wfd
, c
->efd
, c
->ctl_fd
);
368 channel_close_fd(&c
->sock
);
369 channel_close_fd(&c
->ctl_fd
);
370 channel_close_fd(&c
->rfd
);
371 channel_close_fd(&c
->wfd
);
372 channel_close_fd(&c
->efd
);
375 /* Free the channel and close its fd/socket. */
377 channel_free(Channel
*c
)
381 struct channel_confirm
*cc
;
383 for (n
= 0, i
= 0; i
< channels_alloc
; i
++)
386 debug("channel %d: free: %s, nchannels %u", c
->self
,
387 c
->remote_name
? c
->remote_name
: "???", n
);
389 s
= channel_open_message();
390 debug3("channel %d: status: %s", c
->self
, s
);
394 shutdown(c
->sock
, SHUT_RDWR
);
396 shutdown(c
->ctl_fd
, SHUT_RDWR
);
397 channel_close_fds(c
);
398 buffer_free(&c
->input
);
399 buffer_free(&c
->output
);
400 buffer_free(&c
->extended
);
401 if (c
->remote_name
) {
402 xfree(c
->remote_name
);
403 c
->remote_name
= NULL
;
405 while ((cc
= TAILQ_FIRST(&c
->status_confirms
)) != NULL
) {
406 if (cc
->abandon_cb
!= NULL
)
407 cc
->abandon_cb(c
, cc
->ctx
);
408 TAILQ_REMOVE(&c
->status_confirms
, cc
, entry
);
409 bzero(cc
, sizeof(*cc
));
412 if (c
->filter_cleanup
!= NULL
&& c
->filter_ctx
!= NULL
)
413 c
->filter_cleanup(c
->self
, c
->filter_ctx
);
414 channels
[c
->self
] = NULL
;
419 channel_free_all(void)
423 for (i
= 0; i
< channels_alloc
; i
++)
424 if (channels
[i
] != NULL
)
425 channel_free(channels
[i
]);
429 * Closes the sockets/fds of all channels. This is used to close extra file
430 * descriptors after a fork.
433 channel_close_all(void)
437 for (i
= 0; i
< channels_alloc
; i
++)
438 if (channels
[i
] != NULL
)
439 channel_close_fds(channels
[i
]);
443 * Stop listening to channels.
446 channel_stop_listening(void)
451 for (i
= 0; i
< channels_alloc
; i
++) {
455 case SSH_CHANNEL_AUTH_SOCKET
:
456 case SSH_CHANNEL_PORT_LISTENER
:
457 case SSH_CHANNEL_RPORT_LISTENER
:
458 case SSH_CHANNEL_X11_LISTENER
:
459 channel_close_fd(&c
->sock
);
468 * Returns true if no channel has too much buffered data, and false if one or
469 * more channel is overfull.
472 channel_not_very_much_buffered_data(void)
477 for (i
= 0; i
< channels_alloc
; i
++) {
479 if (c
!= NULL
&& c
->type
== SSH_CHANNEL_OPEN
) {
482 buffer_len(&c
->input
) > packet_get_maxsize()) {
483 debug2("channel %d: big input buffer %d",
484 c
->self
, buffer_len(&c
->input
));
488 if (buffer_len(&c
->output
) > packet_get_maxsize()) {
489 debug2("channel %d: big output buffer %u > %u",
490 c
->self
, buffer_len(&c
->output
),
491 packet_get_maxsize());
499 /* Returns true if any channel is still open. */
501 channel_still_open(void)
506 for (i
= 0; i
< channels_alloc
; i
++) {
511 case SSH_CHANNEL_X11_LISTENER
:
512 case SSH_CHANNEL_PORT_LISTENER
:
513 case SSH_CHANNEL_RPORT_LISTENER
:
514 case SSH_CHANNEL_CLOSED
:
515 case SSH_CHANNEL_AUTH_SOCKET
:
516 case SSH_CHANNEL_DYNAMIC
:
517 case SSH_CHANNEL_CONNECTING
:
518 case SSH_CHANNEL_ZOMBIE
:
520 case SSH_CHANNEL_LARVAL
:
522 fatal("cannot happen: SSH_CHANNEL_LARVAL");
524 case SSH_CHANNEL_OPENING
:
525 case SSH_CHANNEL_OPEN
:
526 case SSH_CHANNEL_X11_OPEN
:
528 case SSH_CHANNEL_INPUT_DRAINING
:
529 case SSH_CHANNEL_OUTPUT_DRAINING
:
531 fatal("cannot happen: OUT_DRAIN");
534 fatal("channel_still_open: bad channel type %d", c
->type
);
541 /* Returns the id of an open channel suitable for keepaliving */
543 channel_find_open(void)
548 for (i
= 0; i
< channels_alloc
; i
++) {
550 if (c
== NULL
|| c
->remote_id
< 0)
553 case SSH_CHANNEL_CLOSED
:
554 case SSH_CHANNEL_DYNAMIC
:
555 case SSH_CHANNEL_X11_LISTENER
:
556 case SSH_CHANNEL_PORT_LISTENER
:
557 case SSH_CHANNEL_RPORT_LISTENER
:
558 case SSH_CHANNEL_OPENING
:
559 case SSH_CHANNEL_CONNECTING
:
560 case SSH_CHANNEL_ZOMBIE
:
562 case SSH_CHANNEL_LARVAL
:
563 case SSH_CHANNEL_AUTH_SOCKET
:
564 case SSH_CHANNEL_OPEN
:
565 case SSH_CHANNEL_X11_OPEN
:
567 case SSH_CHANNEL_INPUT_DRAINING
:
568 case SSH_CHANNEL_OUTPUT_DRAINING
:
570 fatal("cannot happen: OUT_DRAIN");
573 fatal("channel_find_open: bad channel type %d", c
->type
);
582 * Returns a message describing the currently open forwarded connections,
583 * suitable for sending to the client. The message contains crlf pairs for
587 channel_open_message(void)
594 buffer_init(&buffer
);
595 snprintf(buf
, sizeof buf
, "The following connections are open:\r\n");
596 buffer_append(&buffer
, buf
, strlen(buf
));
597 for (i
= 0; i
< channels_alloc
; i
++) {
602 case SSH_CHANNEL_X11_LISTENER
:
603 case SSH_CHANNEL_PORT_LISTENER
:
604 case SSH_CHANNEL_RPORT_LISTENER
:
605 case SSH_CHANNEL_CLOSED
:
606 case SSH_CHANNEL_AUTH_SOCKET
:
607 case SSH_CHANNEL_ZOMBIE
:
609 case SSH_CHANNEL_LARVAL
:
610 case SSH_CHANNEL_OPENING
:
611 case SSH_CHANNEL_CONNECTING
:
612 case SSH_CHANNEL_DYNAMIC
:
613 case SSH_CHANNEL_OPEN
:
614 case SSH_CHANNEL_X11_OPEN
:
615 case SSH_CHANNEL_INPUT_DRAINING
:
616 case SSH_CHANNEL_OUTPUT_DRAINING
:
617 snprintf(buf
, sizeof buf
,
618 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
619 c
->self
, c
->remote_name
,
620 c
->type
, c
->remote_id
,
621 c
->istate
, buffer_len(&c
->input
),
622 c
->ostate
, buffer_len(&c
->output
),
623 c
->rfd
, c
->wfd
, c
->ctl_fd
);
624 buffer_append(&buffer
, buf
, strlen(buf
));
627 fatal("channel_open_message: bad channel type %d", c
->type
);
631 buffer_append(&buffer
, "\0", 1);
632 cp
= xstrdup(buffer_ptr(&buffer
));
633 buffer_free(&buffer
);
638 channel_send_open(int id
)
640 Channel
*c
= channel_lookup(id
);
643 logit("channel_send_open: %d: bad id", id
);
646 debug2("channel %d: send open", id
);
647 packet_start(SSH2_MSG_CHANNEL_OPEN
);
648 packet_put_cstring(c
->ctype
);
649 packet_put_int(c
->self
);
650 packet_put_int(c
->local_window
);
651 packet_put_int(c
->local_maxpacket
);
656 channel_request_start(int id
, char *service
, int wantconfirm
)
658 Channel
*c
= channel_lookup(id
);
661 logit("channel_request_start: %d: unknown channel id", id
);
664 debug2("channel %d: request %s confirm %d", id
, service
, wantconfirm
);
665 packet_start(SSH2_MSG_CHANNEL_REQUEST
);
666 packet_put_int(c
->remote_id
);
667 packet_put_cstring(service
);
668 packet_put_char(wantconfirm
);
672 channel_register_status_confirm(int id
, channel_confirm_cb
*cb
,
673 channel_confirm_abandon_cb
*abandon_cb
, void *ctx
)
675 struct channel_confirm
*cc
;
678 if ((c
= channel_lookup(id
)) == NULL
)
679 fatal("channel_register_expect: %d: bad id", id
);
681 cc
= xmalloc(sizeof(*cc
));
683 cc
->abandon_cb
= abandon_cb
;
685 TAILQ_INSERT_TAIL(&c
->status_confirms
, cc
, entry
);
689 channel_register_open_confirm(int id
, channel_callback_fn
*fn
, void *ctx
)
691 Channel
*c
= channel_lookup(id
);
694 logit("channel_register_open_comfirm: %d: bad id", id
);
697 c
->open_confirm
= fn
;
698 c
->open_confirm_ctx
= ctx
;
702 channel_register_cleanup(int id
, channel_callback_fn
*fn
, int do_close
)
704 Channel
*c
= channel_by_id(id
);
707 logit("channel_register_cleanup: %d: bad id", id
);
711 c
->detach_close
= do_close
;
715 channel_cancel_cleanup(int id
)
717 Channel
*c
= channel_by_id(id
);
720 logit("channel_cancel_cleanup: %d: bad id", id
);
723 c
->detach_user
= NULL
;
728 channel_register_filter(int id
, channel_infilter_fn
*ifn
,
729 channel_outfilter_fn
*ofn
, channel_filter_cleanup_fn
*cfn
, void *ctx
)
731 Channel
*c
= channel_lookup(id
);
734 logit("channel_register_filter: %d: bad id", id
);
737 c
->input_filter
= ifn
;
738 c
->output_filter
= ofn
;
740 c
->filter_cleanup
= cfn
;
744 channel_set_fds(int id
, int rfd
, int wfd
, int efd
,
745 int extusage
, int nonblock
, int is_tty
, u_int window_max
)
747 Channel
*c
= channel_lookup(id
);
749 if (c
== NULL
|| c
->type
!= SSH_CHANNEL_LARVAL
)
750 fatal("channel_activate for non-larval channel %d.", id
);
751 channel_register_fds(c
, rfd
, wfd
, efd
, extusage
, nonblock
, is_tty
);
752 c
->type
= SSH_CHANNEL_OPEN
;
753 c
->local_window
= c
->local_window_max
= window_max
;
754 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
755 packet_put_int(c
->remote_id
);
756 packet_put_int(c
->local_window
);
761 * 'channel_pre*' are called just before select() to add any bits relevant to
762 * channels in the select bitmasks.
765 * 'channel_post*': perform any appropriate operations for channels which
766 * have events pending.
768 typedef void chan_fn(Channel
*c
, fd_set
*readset
, fd_set
*writeset
);
769 chan_fn
*channel_pre
[SSH_CHANNEL_MAX_TYPE
];
770 chan_fn
*channel_post
[SSH_CHANNEL_MAX_TYPE
];
774 channel_pre_listener(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
776 FD_SET(c
->sock
, readset
);
781 channel_pre_connecting(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
783 debug3("channel %d: waiting for connection", c
->self
);
784 FD_SET(c
->sock
, writeset
);
788 channel_pre_open_13(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
790 if (buffer_len(&c
->input
) < packet_get_maxsize())
791 FD_SET(c
->sock
, readset
);
792 if (buffer_len(&c
->output
) > 0)
793 FD_SET(c
->sock
, writeset
);
797 channel_pre_open(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
799 u_int limit
= compat20
? c
->remote_window
: packet_get_maxsize();
801 if (c
->istate
== CHAN_INPUT_OPEN
&&
803 buffer_len(&c
->input
) < limit
&&
804 buffer_check_alloc(&c
->input
, CHAN_RBUF
))
805 FD_SET(c
->rfd
, readset
);
806 if (c
->ostate
== CHAN_OUTPUT_OPEN
||
807 c
->ostate
== CHAN_OUTPUT_WAIT_DRAIN
) {
808 if (buffer_len(&c
->output
) > 0) {
809 FD_SET(c
->wfd
, writeset
);
810 } else if (c
->ostate
== CHAN_OUTPUT_WAIT_DRAIN
) {
811 if (CHANNEL_EFD_OUTPUT_ACTIVE(c
))
812 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
813 c
->self
, c
->efd
, buffer_len(&c
->extended
));
818 /** XXX check close conditions, too */
819 if (compat20
&& c
->efd
!= -1 &&
820 !(c
->istate
== CHAN_INPUT_CLOSED
&& c
->ostate
== CHAN_OUTPUT_CLOSED
)) {
821 if (c
->extended_usage
== CHAN_EXTENDED_WRITE
&&
822 buffer_len(&c
->extended
) > 0)
823 FD_SET(c
->efd
, writeset
);
824 else if (!(c
->flags
& CHAN_EOF_SENT
) &&
825 c
->extended_usage
== CHAN_EXTENDED_READ
&&
826 buffer_len(&c
->extended
) < c
->remote_window
)
827 FD_SET(c
->efd
, readset
);
829 /* XXX: What about efd? races? */
830 if (compat20
&& c
->ctl_fd
!= -1 &&
831 c
->istate
== CHAN_INPUT_OPEN
&& c
->ostate
== CHAN_OUTPUT_OPEN
)
832 FD_SET(c
->ctl_fd
, readset
);
837 channel_pre_input_draining(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
839 if (buffer_len(&c
->input
) == 0) {
840 packet_start(SSH_MSG_CHANNEL_CLOSE
);
841 packet_put_int(c
->remote_id
);
843 c
->type
= SSH_CHANNEL_CLOSED
;
844 debug2("channel %d: closing after input drain.", c
->self
);
850 channel_pre_output_draining(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
852 if (buffer_len(&c
->output
) == 0)
855 FD_SET(c
->sock
, writeset
);
859 * This is a special state for X11 authentication spoofing. An opened X11
860 * connection (when authentication spoofing is being done) remains in this
861 * state until the first packet has been completely read. The authentication
862 * data in that packet is then substituted by the real data if it matches the
863 * fake data, and the channel is put into normal mode.
864 * XXX All this happens at the client side.
865 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
868 x11_open_helper(Buffer
*b
)
871 u_int proto_len
, data_len
;
873 /* Check if the fixed size part of the packet is in buffer. */
874 if (buffer_len(b
) < 12)
877 /* Parse the lengths of variable-length fields. */
879 if (ucp
[0] == 0x42) { /* Byte order MSB first. */
880 proto_len
= 256 * ucp
[6] + ucp
[7];
881 data_len
= 256 * ucp
[8] + ucp
[9];
882 } else if (ucp
[0] == 0x6c) { /* Byte order LSB first. */
883 proto_len
= ucp
[6] + 256 * ucp
[7];
884 data_len
= ucp
[8] + 256 * ucp
[9];
886 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
891 /* Check if the whole packet is in buffer. */
893 12 + ((proto_len
+ 3) & ~3) + ((data_len
+ 3) & ~3))
896 /* Check if authentication protocol matches. */
897 if (proto_len
!= strlen(x11_saved_proto
) ||
898 memcmp(ucp
+ 12, x11_saved_proto
, proto_len
) != 0) {
899 debug2("X11 connection uses different authentication protocol.");
902 /* Check if authentication data matches our fake data. */
903 if (data_len
!= x11_fake_data_len
||
904 memcmp(ucp
+ 12 + ((proto_len
+ 3) & ~3),
905 x11_fake_data
, x11_fake_data_len
) != 0) {
906 debug2("X11 auth data does not match fake data.");
909 /* Check fake data length */
910 if (x11_fake_data_len
!= x11_saved_data_len
) {
911 error("X11 fake_data_len %d != saved_data_len %d",
912 x11_fake_data_len
, x11_saved_data_len
);
916 * Received authentication protocol and data match
917 * our fake data. Substitute the fake data with real
920 memcpy(ucp
+ 12 + ((proto_len
+ 3) & ~3),
921 x11_saved_data
, x11_saved_data_len
);
926 channel_pre_x11_open_13(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
928 int ret
= x11_open_helper(&c
->output
);
931 /* Start normal processing for the channel. */
932 c
->type
= SSH_CHANNEL_OPEN
;
933 channel_pre_open_13(c
, readset
, writeset
);
934 } else if (ret
== -1) {
936 * We have received an X11 connection that has bad
937 * authentication information.
939 logit("X11 connection rejected because of wrong authentication.");
940 buffer_clear(&c
->input
);
941 buffer_clear(&c
->output
);
942 channel_close_fd(&c
->sock
);
944 c
->type
= SSH_CHANNEL_CLOSED
;
945 packet_start(SSH_MSG_CHANNEL_CLOSE
);
946 packet_put_int(c
->remote_id
);
952 channel_pre_x11_open(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
954 int ret
= x11_open_helper(&c
->output
);
956 /* c->force_drain = 1; */
959 c
->type
= SSH_CHANNEL_OPEN
;
960 channel_pre_open(c
, readset
, writeset
);
961 } else if (ret
== -1) {
962 logit("X11 connection rejected because of wrong authentication.");
963 debug2("X11 rejected %d i%d/o%d", c
->self
, c
->istate
, c
->ostate
);
965 buffer_clear(&c
->input
);
967 buffer_clear(&c
->output
);
968 /* for proto v1, the peer will send an IEOF */
970 chan_write_failed(c
);
972 c
->type
= SSH_CHANNEL_OPEN
;
973 debug2("X11 closed %d i%d/o%d", c
->self
, c
->istate
, c
->ostate
);
977 /* try to decode a socks4 header */
980 channel_decode_socks4(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
983 u_int len
, have
, i
, found
;
989 struct in_addr dest_addr
;
992 debug2("channel %d: decode socks4", c
->self
);
994 have
= buffer_len(&c
->input
);
995 len
= sizeof(s4_req
);
998 p
= buffer_ptr(&c
->input
);
999 for (found
= 0, i
= len
; i
< have
; i
++) {
1005 /* the peer is probably sending garbage */
1006 debug("channel %d: decode socks4: too long",
1013 buffer_get(&c
->input
, (char *)&s4_req
.version
, 1);
1014 buffer_get(&c
->input
, (char *)&s4_req
.command
, 1);
1015 buffer_get(&c
->input
, (char *)&s4_req
.dest_port
, 2);
1016 buffer_get(&c
->input
, (char *)&s4_req
.dest_addr
, 4);
1017 have
= buffer_len(&c
->input
);
1018 p
= buffer_ptr(&c
->input
);
1020 debug2("channel %d: decode socks4: user %s/%d", c
->self
, p
, len
);
1022 fatal("channel %d: decode socks4: len %d > have %d",
1023 c
->self
, len
, have
);
1024 strlcpy(username
, p
, sizeof(username
));
1025 buffer_consume(&c
->input
, len
);
1026 buffer_consume(&c
->input
, 1); /* trailing '\0' */
1028 host
= inet_ntoa(s4_req
.dest_addr
);
1029 strlcpy(c
->path
, host
, sizeof(c
->path
));
1030 c
->host_port
= ntohs(s4_req
.dest_port
);
1032 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1033 c
->self
, host
, c
->host_port
, s4_req
.command
);
1035 if (s4_req
.command
!= 1) {
1036 debug("channel %d: cannot handle: socks4 cn %d",
1037 c
->self
, s4_req
.command
);
1040 s4_rsp
.version
= 0; /* vn: 0 for reply */
1041 s4_rsp
.command
= 90; /* cd: req granted */
1042 s4_rsp
.dest_port
= 0; /* ignored */
1043 s4_rsp
.dest_addr
.s_addr
= INADDR_ANY
; /* ignored */
1044 buffer_append(&c
->output
, &s4_rsp
, sizeof(s4_rsp
));
1048 /* try to decode a socks5 header */
1049 #define SSH_SOCKS5_AUTHDONE 0x1000
1050 #define SSH_SOCKS5_NOAUTH 0x00
1051 #define SSH_SOCKS5_IPV4 0x01
1052 #define SSH_SOCKS5_DOMAIN 0x03
1053 #define SSH_SOCKS5_IPV6 0x04
1054 #define SSH_SOCKS5_CONNECT 0x01
1055 #define SSH_SOCKS5_SUCCESS 0x00
1059 channel_decode_socks5(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1067 u_int16_t dest_port
;
1068 u_char
*p
, dest_addr
[255+1];
1069 u_int have
, need
, i
, found
, nmethods
, addrlen
, af
;
1071 debug2("channel %d: decode socks5", c
->self
);
1072 p
= buffer_ptr(&c
->input
);
1075 have
= buffer_len(&c
->input
);
1076 if (!(c
->flags
& SSH_SOCKS5_AUTHDONE
)) {
1077 /* format: ver | nmethods | methods */
1081 if (have
< nmethods
+ 2)
1083 /* look for method: "NO AUTHENTICATION REQUIRED" */
1084 for (found
= 0, i
= 2; i
< nmethods
+ 2; i
++) {
1085 if (p
[i
] == SSH_SOCKS5_NOAUTH
) {
1091 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1095 buffer_consume(&c
->input
, nmethods
+ 2);
1096 buffer_put_char(&c
->output
, 0x05); /* version */
1097 buffer_put_char(&c
->output
, SSH_SOCKS5_NOAUTH
); /* method */
1098 FD_SET(c
->sock
, writeset
);
1099 c
->flags
|= SSH_SOCKS5_AUTHDONE
;
1100 debug2("channel %d: socks5 auth done", c
->self
);
1101 return 0; /* need more */
1103 debug2("channel %d: socks5 post auth", c
->self
);
1104 if (have
< sizeof(s5_req
)+1)
1105 return 0; /* need more */
1106 memcpy(&s5_req
, p
, sizeof(s5_req
));
1107 if (s5_req
.version
!= 0x05 ||
1108 s5_req
.command
!= SSH_SOCKS5_CONNECT
||
1109 s5_req
.reserved
!= 0x00) {
1110 debug2("channel %d: only socks5 connect supported", c
->self
);
1113 switch (s5_req
.atyp
){
1114 case SSH_SOCKS5_IPV4
:
1118 case SSH_SOCKS5_DOMAIN
:
1119 addrlen
= p
[sizeof(s5_req
)];
1122 case SSH_SOCKS5_IPV6
:
1127 debug2("channel %d: bad socks5 atyp %d", c
->self
, s5_req
.atyp
);
1130 need
= sizeof(s5_req
) + addrlen
+ 2;
1131 if (s5_req
.atyp
== SSH_SOCKS5_DOMAIN
)
1135 buffer_consume(&c
->input
, sizeof(s5_req
));
1136 if (s5_req
.atyp
== SSH_SOCKS5_DOMAIN
)
1137 buffer_consume(&c
->input
, 1); /* host string length */
1138 buffer_get(&c
->input
, (char *)&dest_addr
, addrlen
);
1139 buffer_get(&c
->input
, (char *)&dest_port
, 2);
1140 dest_addr
[addrlen
] = '\0';
1141 if (s5_req
.atyp
== SSH_SOCKS5_DOMAIN
)
1142 strlcpy(c
->path
, (char *)dest_addr
, sizeof(c
->path
));
1143 else if (inet_ntop(af
, dest_addr
, c
->path
, sizeof(c
->path
)) == NULL
)
1145 c
->host_port
= ntohs(dest_port
);
1147 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1148 c
->self
, c
->path
, c
->host_port
, s5_req
.command
);
1150 s5_rsp
.version
= 0x05;
1151 s5_rsp
.command
= SSH_SOCKS5_SUCCESS
;
1152 s5_rsp
.reserved
= 0; /* ignored */
1153 s5_rsp
.atyp
= SSH_SOCKS5_IPV4
;
1154 ((struct in_addr
*)&dest_addr
)->s_addr
= INADDR_ANY
;
1155 dest_port
= 0; /* ignored */
1157 buffer_append(&c
->output
, &s5_rsp
, sizeof(s5_rsp
));
1158 buffer_append(&c
->output
, &dest_addr
, sizeof(struct in_addr
));
1159 buffer_append(&c
->output
, &dest_port
, sizeof(dest_port
));
1163 /* dynamic port forwarding */
1165 channel_pre_dynamic(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1171 have
= buffer_len(&c
->input
);
1173 debug2("channel %d: pre_dynamic: have %d", c
->self
, have
);
1174 /* buffer_dump(&c->input); */
1175 /* check if the fixed size part of the packet is in buffer. */
1178 FD_SET(c
->sock
, readset
);
1181 /* try to guess the protocol */
1182 p
= buffer_ptr(&c
->input
);
1185 ret
= channel_decode_socks4(c
, readset
, writeset
);
1188 ret
= channel_decode_socks5(c
, readset
, writeset
);
1196 } else if (ret
== 0) {
1197 debug2("channel %d: pre_dynamic: need more", c
->self
);
1199 FD_SET(c
->sock
, readset
);
1201 /* switch to the next state */
1202 c
->type
= SSH_CHANNEL_OPENING
;
1203 port_open_helper(c
, "direct-tcpip");
1207 /* This is our fake X11 server socket. */
1210 channel_post_x11_listener(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1213 struct sockaddr_storage addr
;
1216 char buf
[16384], *remote_ipaddr
;
1219 if (FD_ISSET(c
->sock
, readset
)) {
1220 debug("X11 connection requested.");
1221 addrlen
= sizeof(addr
);
1222 newsock
= accept(c
->sock
, (struct sockaddr
*)&addr
, &addrlen
);
1223 if (c
->single_connection
) {
1224 debug2("single_connection: closing X11 listener.");
1225 channel_close_fd(&c
->sock
);
1229 error("accept: %.100s", strerror(errno
));
1232 set_nodelay(newsock
);
1233 remote_ipaddr
= get_peer_ipaddr(newsock
);
1234 remote_port
= get_peer_port(newsock
);
1235 snprintf(buf
, sizeof buf
, "X11 connection from %.200s port %d",
1236 remote_ipaddr
, remote_port
);
1238 nc
= channel_new("accepted x11 socket",
1239 SSH_CHANNEL_OPENING
, newsock
, newsock
, -1,
1240 c
->local_window_max
, c
->local_maxpacket
, 0, buf
, 1);
1242 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1243 packet_put_cstring("x11");
1244 packet_put_int(nc
->self
);
1245 packet_put_int(nc
->local_window_max
);
1246 packet_put_int(nc
->local_maxpacket
);
1247 /* originator ipaddr and port */
1248 packet_put_cstring(remote_ipaddr
);
1249 if (datafellows
& SSH_BUG_X11FWD
) {
1250 debug2("ssh2 x11 bug compat mode");
1252 packet_put_int(remote_port
);
1256 packet_start(SSH_SMSG_X11_OPEN
);
1257 packet_put_int(nc
->self
);
1258 if (packet_get_protocol_flags() &
1259 SSH_PROTOFLAG_HOST_IN_FWD_OPEN
)
1260 packet_put_cstring(buf
);
1263 xfree(remote_ipaddr
);
1268 port_open_helper(Channel
*c
, char *rtype
)
1272 char *remote_ipaddr
= get_peer_ipaddr(c
->sock
);
1273 int remote_port
= get_peer_port(c
->sock
);
1275 direct
= (strcmp(rtype
, "direct-tcpip") == 0);
1277 snprintf(buf
, sizeof buf
,
1278 "%s: listening port %d for %.100s port %d, "
1279 "connect from %.200s port %d",
1280 rtype
, c
->listening_port
, c
->path
, c
->host_port
,
1281 remote_ipaddr
, remote_port
);
1283 xfree(c
->remote_name
);
1284 c
->remote_name
= xstrdup(buf
);
1287 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1288 packet_put_cstring(rtype
);
1289 packet_put_int(c
->self
);
1290 packet_put_int(c
->local_window_max
);
1291 packet_put_int(c
->local_maxpacket
);
1293 /* target host, port */
1294 packet_put_cstring(c
->path
);
1295 packet_put_int(c
->host_port
);
1297 /* listen address, port */
1298 packet_put_cstring(c
->path
);
1299 packet_put_int(c
->listening_port
);
1301 /* originator host and port */
1302 packet_put_cstring(remote_ipaddr
);
1303 packet_put_int((u_int
)remote_port
);
1306 packet_start(SSH_MSG_PORT_OPEN
);
1307 packet_put_int(c
->self
);
1308 packet_put_cstring(c
->path
);
1309 packet_put_int(c
->host_port
);
1310 if (packet_get_protocol_flags() &
1311 SSH_PROTOFLAG_HOST_IN_FWD_OPEN
)
1312 packet_put_cstring(c
->remote_name
);
1315 xfree(remote_ipaddr
);
1319 channel_set_reuseaddr(int fd
)
1324 * Set socket options.
1325 * Allow local port reuse in TIME_WAIT.
1327 if (setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &on
, sizeof(on
)) == -1)
1328 error("setsockopt SO_REUSEADDR fd %d: %s", fd
, strerror(errno
));
1332 * This socket is listening for connections to a forwarded TCP/IP port.
1336 channel_post_port_listener(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1339 struct sockaddr_storage addr
;
1340 int newsock
, nextstate
;
1344 if (FD_ISSET(c
->sock
, readset
)) {
1345 debug("Connection to port %d forwarding "
1346 "to %.100s port %d requested.",
1347 c
->listening_port
, c
->path
, c
->host_port
);
1349 if (c
->type
== SSH_CHANNEL_RPORT_LISTENER
) {
1350 nextstate
= SSH_CHANNEL_OPENING
;
1351 rtype
= "forwarded-tcpip";
1353 if (c
->host_port
== 0) {
1354 nextstate
= SSH_CHANNEL_DYNAMIC
;
1355 rtype
= "dynamic-tcpip";
1357 nextstate
= SSH_CHANNEL_OPENING
;
1358 rtype
= "direct-tcpip";
1362 addrlen
= sizeof(addr
);
1363 newsock
= accept(c
->sock
, (struct sockaddr
*)&addr
, &addrlen
);
1365 error("accept: %.100s", strerror(errno
));
1368 set_nodelay(newsock
);
1369 nc
= channel_new(rtype
, nextstate
, newsock
, newsock
, -1,
1370 c
->local_window_max
, c
->local_maxpacket
, 0, rtype
, 1);
1371 nc
->listening_port
= c
->listening_port
;
1372 nc
->host_port
= c
->host_port
;
1373 strlcpy(nc
->path
, c
->path
, sizeof(nc
->path
));
1375 if (nextstate
== SSH_CHANNEL_DYNAMIC
) {
1377 * do not call the channel_post handler until
1378 * this flag has been reset by a pre-handler.
1379 * otherwise the FD_ISSET calls might overflow
1383 port_open_helper(nc
, rtype
);
1389 * This is the authentication agent socket listening for connections from
1394 channel_post_auth_listener(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1398 struct sockaddr_storage addr
;
1401 if (FD_ISSET(c
->sock
, readset
)) {
1402 addrlen
= sizeof(addr
);
1403 newsock
= accept(c
->sock
, (struct sockaddr
*)&addr
, &addrlen
);
1405 error("accept from auth socket: %.100s", strerror(errno
));
1408 nc
= channel_new("accepted auth socket",
1409 SSH_CHANNEL_OPENING
, newsock
, newsock
, -1,
1410 c
->local_window_max
, c
->local_maxpacket
,
1411 0, "accepted auth socket", 1);
1413 packet_start(SSH2_MSG_CHANNEL_OPEN
);
1414 packet_put_cstring("auth-agent@openssh.com");
1415 packet_put_int(nc
->self
);
1416 packet_put_int(c
->local_window_max
);
1417 packet_put_int(c
->local_maxpacket
);
1419 packet_start(SSH_SMSG_AGENT_OPEN
);
1420 packet_put_int(nc
->self
);
1428 channel_post_connecting(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1431 socklen_t sz
= sizeof(err
);
1433 if (FD_ISSET(c
->sock
, writeset
)) {
1434 if (getsockopt(c
->sock
, SOL_SOCKET
, SO_ERROR
, &err
, &sz
) < 0) {
1436 error("getsockopt SO_ERROR failed");
1439 debug("channel %d: connected to %s port %d",
1440 c
->self
, c
->connect_ctx
.host
, c
->connect_ctx
.port
);
1441 channel_connect_ctx_free(&c
->connect_ctx
);
1442 c
->type
= SSH_CHANNEL_OPEN
;
1444 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
1445 packet_put_int(c
->remote_id
);
1446 packet_put_int(c
->self
);
1447 packet_put_int(c
->local_window
);
1448 packet_put_int(c
->local_maxpacket
);
1450 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION
);
1451 packet_put_int(c
->remote_id
);
1452 packet_put_int(c
->self
);
1455 debug("channel %d: connection failed: %s",
1456 c
->self
, strerror(err
));
1457 /* Try next address, if any */
1458 if ((sock
= connect_next(&c
->connect_ctx
)) > 0) {
1460 c
->sock
= c
->rfd
= c
->wfd
= sock
;
1461 channel_max_fd
= channel_find_maxfd();
1464 /* Exhausted all addresses */
1465 error("connect_to %.100s port %d: failed.",
1466 c
->connect_ctx
.host
, c
->connect_ctx
.port
);
1467 channel_connect_ctx_free(&c
->connect_ctx
);
1469 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
1470 packet_put_int(c
->remote_id
);
1471 packet_put_int(SSH2_OPEN_CONNECT_FAILED
);
1472 if (!(datafellows
& SSH_BUG_OPENFAILURE
)) {
1473 packet_put_cstring(strerror(err
));
1474 packet_put_cstring("");
1477 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
1478 packet_put_int(c
->remote_id
);
1488 channel_handle_rfd(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1490 char buf
[CHAN_RBUF
];
1493 force
= c
->isatty
&& c
->detach_close
&& c
->istate
!= CHAN_INPUT_CLOSED
;
1494 if (c
->rfd
!= -1 && (force
|| FD_ISSET(c
->rfd
, readset
))) {
1496 len
= read(c
->rfd
, buf
, sizeof(buf
));
1497 if (len
< 0 && (errno
== EINTR
||
1498 ((errno
== EAGAIN
|| errno
== EWOULDBLOCK
) && !force
)))
1500 #ifndef PTY_ZEROREAD
1503 if ((!c
->isatty
&& len
<= 0) ||
1504 (c
->isatty
&& (len
< 0 || (len
== 0 && errno
!= 0)))) {
1506 debug2("channel %d: read<=0 rfd %d len %d",
1507 c
->self
, c
->rfd
, len
);
1508 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1509 debug2("channel %d: not open", c
->self
);
1512 } else if (compat13
) {
1513 buffer_clear(&c
->output
);
1514 c
->type
= SSH_CHANNEL_INPUT_DRAINING
;
1515 debug2("channel %d: input draining.", c
->self
);
1517 chan_read_failed(c
);
1521 if (c
->input_filter
!= NULL
) {
1522 if (c
->input_filter(c
, buf
, len
) == -1) {
1523 debug2("channel %d: filter stops", c
->self
);
1524 chan_read_failed(c
);
1526 } else if (c
->datagram
) {
1527 buffer_put_string(&c
->input
, buf
, len
);
1529 buffer_append(&c
->input
, buf
, len
);
1537 channel_handle_wfd(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1540 u_char
*data
= NULL
, *buf
;
1544 /* Send buffered output data to the socket. */
1546 FD_ISSET(c
->wfd
, writeset
) &&
1547 buffer_len(&c
->output
) > 0) {
1548 if (c
->output_filter
!= NULL
) {
1549 if ((buf
= c
->output_filter(c
, &data
, &dlen
)) == NULL
) {
1550 debug2("channel %d: filter stops", c
->self
);
1551 if (c
->type
!= SSH_CHANNEL_OPEN
)
1554 chan_write_failed(c
);
1557 } else if (c
->datagram
) {
1558 buf
= data
= buffer_get_string(&c
->output
, &dlen
);
1560 buf
= data
= buffer_ptr(&c
->output
);
1561 dlen
= buffer_len(&c
->output
);
1565 /* ignore truncated writes, datagrams might get lost */
1566 c
->local_consumed
+= dlen
+ 4;
1567 len
= write(c
->wfd
, buf
, dlen
);
1569 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
||
1570 errno
== EWOULDBLOCK
))
1573 if (c
->type
!= SSH_CHANNEL_OPEN
)
1576 chan_write_failed(c
);
1582 /* XXX: Later AIX versions can't push as much data to tty */
1583 if (compat20
&& c
->wfd_isatty
)
1584 dlen
= MIN(dlen
, 8*1024);
1587 len
= write(c
->wfd
, buf
, dlen
);
1589 (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
))
1592 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1593 debug2("channel %d: not open", c
->self
);
1596 } else if (compat13
) {
1597 buffer_clear(&c
->output
);
1598 debug2("channel %d: input draining.", c
->self
);
1599 c
->type
= SSH_CHANNEL_INPUT_DRAINING
;
1601 chan_write_failed(c
);
1605 if (compat20
&& c
->isatty
&& dlen
>= 1 && buf
[0] != '\r') {
1606 if (tcgetattr(c
->wfd
, &tio
) == 0 &&
1607 !(tio
.c_lflag
& ECHO
) && (tio
.c_lflag
& ICANON
)) {
1609 * Simulate echo to reduce the impact of
1610 * traffic analysis. We need to match the
1611 * size of a SSH2_MSG_CHANNEL_DATA message
1612 * (4 byte channel id + buf)
1614 packet_send_ignore(4 + len
);
1618 buffer_consume(&c
->output
, len
);
1619 if (compat20
&& len
> 0) {
1620 c
->local_consumed
+= len
;
1627 channel_handle_efd(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1629 char buf
[CHAN_RBUF
];
1632 /** XXX handle drain efd, too */
1634 if (c
->extended_usage
== CHAN_EXTENDED_WRITE
&&
1635 FD_ISSET(c
->efd
, writeset
) &&
1636 buffer_len(&c
->extended
) > 0) {
1637 len
= write(c
->efd
, buffer_ptr(&c
->extended
),
1638 buffer_len(&c
->extended
));
1639 debug2("channel %d: written %d to efd %d",
1640 c
->self
, len
, c
->efd
);
1641 if (len
< 0 && (errno
== EINTR
|| errno
== EAGAIN
||
1642 errno
== EWOULDBLOCK
))
1645 debug2("channel %d: closing write-efd %d",
1647 channel_close_fd(&c
->efd
);
1649 buffer_consume(&c
->extended
, len
);
1650 c
->local_consumed
+= len
;
1652 } else if (c
->extended_usage
== CHAN_EXTENDED_READ
&&
1653 (c
->detach_close
|| FD_ISSET(c
->efd
, readset
))) {
1654 len
= read(c
->efd
, buf
, sizeof(buf
));
1655 debug2("channel %d: read %d from efd %d",
1656 c
->self
, len
, c
->efd
);
1657 if (len
< 0 && (errno
== EINTR
|| ((errno
== EAGAIN
||
1658 errno
== EWOULDBLOCK
) && !c
->detach_close
)))
1661 debug2("channel %d: closing read-efd %d",
1663 channel_close_fd(&c
->efd
);
1665 buffer_append(&c
->extended
, buf
, len
);
1674 channel_handle_ctl(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1679 /* Monitor control fd to detect if the slave client exits */
1680 if (c
->ctl_fd
!= -1 && FD_ISSET(c
->ctl_fd
, readset
)) {
1681 len
= read(c
->ctl_fd
, buf
, sizeof(buf
));
1683 (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
))
1686 debug2("channel %d: ctl read<=0", c
->self
);
1687 if (c
->type
!= SSH_CHANNEL_OPEN
) {
1688 debug2("channel %d: not open", c
->self
);
1692 chan_read_failed(c
);
1693 chan_write_failed(c
);
1697 fatal("%s: unexpected data on ctl fd", __func__
);
1703 channel_check_window(Channel
*c
)
1705 if (c
->type
== SSH_CHANNEL_OPEN
&&
1706 !(c
->flags
& (CHAN_CLOSE_SENT
|CHAN_CLOSE_RCVD
)) &&
1707 ((c
->local_window_max
- c
->local_window
>
1708 c
->local_maxpacket
*3) ||
1709 c
->local_window
< c
->local_window_max
/2) &&
1710 c
->local_consumed
> 0) {
1711 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1712 packet_put_int(c
->remote_id
);
1713 packet_put_int(c
->local_consumed
);
1715 debug2("channel %d: window %d sent adjust %d",
1716 c
->self
, c
->local_window
,
1718 c
->local_window
+= c
->local_consumed
;
1719 c
->local_consumed
= 0;
1725 channel_post_open(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1729 channel_handle_rfd(c
, readset
, writeset
);
1730 channel_handle_wfd(c
, readset
, writeset
);
1733 channel_handle_efd(c
, readset
, writeset
);
1734 channel_handle_ctl(c
, readset
, writeset
);
1735 channel_check_window(c
);
1740 channel_post_output_drain_13(Channel
*c
, fd_set
*readset
, fd_set
*writeset
)
1744 /* Send buffered output data to the socket. */
1745 if (FD_ISSET(c
->sock
, writeset
) && buffer_len(&c
->output
) > 0) {
1746 len
= write(c
->sock
, buffer_ptr(&c
->output
),
1747 buffer_len(&c
->output
));
1749 buffer_clear(&c
->output
);
1751 buffer_consume(&c
->output
, len
);
1756 channel_handler_init_20(void)
1758 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open
;
1759 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open
;
1760 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1761 channel_pre
[SSH_CHANNEL_RPORT_LISTENER
] = &channel_pre_listener
;
1762 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1763 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1764 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1765 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1767 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1768 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1769 channel_post
[SSH_CHANNEL_RPORT_LISTENER
] = &channel_post_port_listener
;
1770 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1771 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1772 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1773 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1777 channel_handler_init_13(void)
1779 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open_13
;
1780 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open_13
;
1781 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1782 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1783 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1784 channel_pre
[SSH_CHANNEL_INPUT_DRAINING
] = &channel_pre_input_draining
;
1785 channel_pre
[SSH_CHANNEL_OUTPUT_DRAINING
] = &channel_pre_output_draining
;
1786 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1787 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1789 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1790 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1791 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1792 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1793 channel_post
[SSH_CHANNEL_OUTPUT_DRAINING
] = &channel_post_output_drain_13
;
1794 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1795 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1799 channel_handler_init_15(void)
1801 channel_pre
[SSH_CHANNEL_OPEN
] = &channel_pre_open
;
1802 channel_pre
[SSH_CHANNEL_X11_OPEN
] = &channel_pre_x11_open
;
1803 channel_pre
[SSH_CHANNEL_X11_LISTENER
] = &channel_pre_listener
;
1804 channel_pre
[SSH_CHANNEL_PORT_LISTENER
] = &channel_pre_listener
;
1805 channel_pre
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_pre_listener
;
1806 channel_pre
[SSH_CHANNEL_CONNECTING
] = &channel_pre_connecting
;
1807 channel_pre
[SSH_CHANNEL_DYNAMIC
] = &channel_pre_dynamic
;
1809 channel_post
[SSH_CHANNEL_X11_LISTENER
] = &channel_post_x11_listener
;
1810 channel_post
[SSH_CHANNEL_PORT_LISTENER
] = &channel_post_port_listener
;
1811 channel_post
[SSH_CHANNEL_AUTH_SOCKET
] = &channel_post_auth_listener
;
1812 channel_post
[SSH_CHANNEL_OPEN
] = &channel_post_open
;
1813 channel_post
[SSH_CHANNEL_CONNECTING
] = &channel_post_connecting
;
1814 channel_post
[SSH_CHANNEL_DYNAMIC
] = &channel_post_open
;
1818 channel_handler_init(void)
1822 for (i
= 0; i
< SSH_CHANNEL_MAX_TYPE
; i
++) {
1823 channel_pre
[i
] = NULL
;
1824 channel_post
[i
] = NULL
;
1827 channel_handler_init_20();
1829 channel_handler_init_13();
1831 channel_handler_init_15();
1834 /* gc dead channels */
1836 channel_garbage_collect(Channel
*c
)
1840 if (c
->detach_user
!= NULL
) {
1841 if (!chan_is_dead(c
, c
->detach_close
))
1843 debug2("channel %d: gc: notify user", c
->self
);
1844 c
->detach_user(c
->self
, NULL
);
1845 /* if we still have a callback */
1846 if (c
->detach_user
!= NULL
)
1848 debug2("channel %d: gc: user detached", c
->self
);
1850 if (!chan_is_dead(c
, 1))
1852 debug2("channel %d: garbage collecting", c
->self
);
1857 channel_handler(chan_fn
*ftab
[], fd_set
*readset
, fd_set
*writeset
)
1859 static int did_init
= 0;
1864 channel_handler_init();
1867 for (i
= 0; i
< channels_alloc
; i
++) {
1871 if (ftab
[c
->type
] != NULL
)
1872 (*ftab
[c
->type
])(c
, readset
, writeset
);
1873 channel_garbage_collect(c
);
1878 * Allocate/update select bitmasks and add any bits relevant to channels in
1882 channel_prepare_select(fd_set
**readsetp
, fd_set
**writesetp
, int *maxfdp
,
1883 u_int
*nallocp
, int rekeying
)
1885 u_int n
, sz
, nfdset
;
1887 n
= MAX(*maxfdp
, channel_max_fd
);
1889 nfdset
= howmany(n
+1, NFDBITS
);
1890 /* Explicitly test here, because xrealloc isn't always called */
1891 if (nfdset
&& SIZE_T_MAX
/ nfdset
< sizeof(fd_mask
))
1892 fatal("channel_prepare_select: max_fd (%d) is too large", n
);
1893 sz
= nfdset
* sizeof(fd_mask
);
1895 /* perhaps check sz < nalloc/2 and shrink? */
1896 if (*readsetp
== NULL
|| sz
> *nallocp
) {
1897 *readsetp
= xrealloc(*readsetp
, nfdset
, sizeof(fd_mask
));
1898 *writesetp
= xrealloc(*writesetp
, nfdset
, sizeof(fd_mask
));
1902 memset(*readsetp
, 0, sz
);
1903 memset(*writesetp
, 0, sz
);
1906 channel_handler(channel_pre
, *readsetp
, *writesetp
);
1910 * After select, perform any appropriate operations for channels which have
1914 channel_after_select(fd_set
*readset
, fd_set
*writeset
)
1916 channel_handler(channel_post
, readset
, writeset
);
1920 /* If there is data to send to the connection, enqueue some of it now. */
1922 channel_output_poll(void)
1927 for (i
= 0; i
< channels_alloc
; i
++) {
1933 * We are only interested in channels that can have buffered
1937 if (c
->type
!= SSH_CHANNEL_OPEN
&&
1938 c
->type
!= SSH_CHANNEL_INPUT_DRAINING
)
1941 if (c
->type
!= SSH_CHANNEL_OPEN
)
1945 (c
->flags
& (CHAN_CLOSE_SENT
|CHAN_CLOSE_RCVD
))) {
1946 /* XXX is this true? */
1947 debug3("channel %d: will not send data after close", c
->self
);
1951 /* Get the amount of buffered data for this channel. */
1952 if ((c
->istate
== CHAN_INPUT_OPEN
||
1953 c
->istate
== CHAN_INPUT_WAIT_DRAIN
) &&
1954 (len
= buffer_len(&c
->input
)) > 0) {
1960 data
= buffer_get_string(&c
->input
,
1962 packet_start(SSH2_MSG_CHANNEL_DATA
);
1963 packet_put_int(c
->remote_id
);
1964 packet_put_string(data
, dlen
);
1966 c
->remote_window
-= dlen
+ 4;
1972 * Send some data for the other side over the secure
1976 if (len
> c
->remote_window
)
1977 len
= c
->remote_window
;
1978 if (len
> c
->remote_maxpacket
)
1979 len
= c
->remote_maxpacket
;
1981 if (packet_is_interactive()) {
1985 /* Keep the packets at reasonable size. */
1986 if (len
> packet_get_maxsize()/2)
1987 len
= packet_get_maxsize()/2;
1991 packet_start(compat20
?
1992 SSH2_MSG_CHANNEL_DATA
: SSH_MSG_CHANNEL_DATA
);
1993 packet_put_int(c
->remote_id
);
1994 packet_put_string(buffer_ptr(&c
->input
), len
);
1996 buffer_consume(&c
->input
, len
);
1997 c
->remote_window
-= len
;
1999 } else if (c
->istate
== CHAN_INPUT_WAIT_DRAIN
) {
2001 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2003 * input-buffer is empty and read-socket shutdown:
2004 * tell peer, that we will not send more data: send IEOF.
2005 * hack for extended data: delay EOF if EFD still in use.
2007 if (CHANNEL_EFD_INPUT_ACTIVE(c
))
2008 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2009 c
->self
, c
->efd
, buffer_len(&c
->extended
));
2013 /* Send extended data, i.e. stderr */
2015 !(c
->flags
& CHAN_EOF_SENT
) &&
2016 c
->remote_window
> 0 &&
2017 (len
= buffer_len(&c
->extended
)) > 0 &&
2018 c
->extended_usage
== CHAN_EXTENDED_READ
) {
2019 debug2("channel %d: rwin %u elen %u euse %d",
2020 c
->self
, c
->remote_window
, buffer_len(&c
->extended
),
2022 if (len
> c
->remote_window
)
2023 len
= c
->remote_window
;
2024 if (len
> c
->remote_maxpacket
)
2025 len
= c
->remote_maxpacket
;
2026 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
2027 packet_put_int(c
->remote_id
);
2028 packet_put_int(SSH2_EXTENDED_DATA_STDERR
);
2029 packet_put_string(buffer_ptr(&c
->extended
), len
);
2031 buffer_consume(&c
->extended
, len
);
2032 c
->remote_window
-= len
;
2033 debug2("channel %d: sent ext data %d", c
->self
, len
);
2039 /* -- protocol input */
2043 channel_input_data(int type
, u_int32_t seq
, void *ctxt
)
2050 /* Get the channel number and verify it. */
2051 id
= packet_get_int();
2052 c
= channel_lookup(id
);
2054 packet_disconnect("Received data for nonexistent channel %d.", id
);
2056 /* Ignore any data for non-open channels (might happen on close) */
2057 if (c
->type
!= SSH_CHANNEL_OPEN
&&
2058 c
->type
!= SSH_CHANNEL_X11_OPEN
)
2062 data
= packet_get_string_ptr(&data_len
);
2065 * Ignore data for protocol > 1.3 if output end is no longer open.
2066 * For protocol 2 the sending side is reducing its window as it sends
2067 * data, so we must 'fake' consumption of the data in order to ensure
2068 * that window updates are sent back. Otherwise the connection might
2071 if (!compat13
&& c
->ostate
!= CHAN_OUTPUT_OPEN
) {
2073 c
->local_window
-= data_len
;
2074 c
->local_consumed
+= data_len
;
2080 if (data_len
> c
->local_maxpacket
) {
2081 logit("channel %d: rcvd big packet %d, maxpack %d",
2082 c
->self
, data_len
, c
->local_maxpacket
);
2084 if (data_len
> c
->local_window
) {
2085 logit("channel %d: rcvd too much data %d, win %d",
2086 c
->self
, data_len
, c
->local_window
);
2089 c
->local_window
-= data_len
;
2092 buffer_put_string(&c
->output
, data
, data_len
);
2094 buffer_append(&c
->output
, data
, data_len
);
2100 channel_input_extended_data(int type
, u_int32_t seq
, void *ctxt
)
2104 u_int data_len
, tcode
;
2107 /* Get the channel number and verify it. */
2108 id
= packet_get_int();
2109 c
= channel_lookup(id
);
2112 packet_disconnect("Received extended_data for bad channel %d.", id
);
2113 if (c
->type
!= SSH_CHANNEL_OPEN
) {
2114 logit("channel %d: ext data for non open", id
);
2117 if (c
->flags
& CHAN_EOF_RCVD
) {
2118 if (datafellows
& SSH_BUG_EXTEOF
)
2119 debug("channel %d: accepting ext data after eof", id
);
2121 packet_disconnect("Received extended_data after EOF "
2122 "on channel %d.", id
);
2124 tcode
= packet_get_int();
2126 c
->extended_usage
!= CHAN_EXTENDED_WRITE
||
2127 tcode
!= SSH2_EXTENDED_DATA_STDERR
) {
2128 logit("channel %d: bad ext data", c
->self
);
2131 data
= packet_get_string(&data_len
);
2133 if (data_len
> c
->local_window
) {
2134 logit("channel %d: rcvd too much extended_data %d, win %d",
2135 c
->self
, data_len
, c
->local_window
);
2139 debug2("channel %d: rcvd ext data %d", c
->self
, data_len
);
2140 c
->local_window
-= data_len
;
2141 buffer_append(&c
->extended
, data
, data_len
);
2147 channel_input_ieof(int type
, u_int32_t seq
, void *ctxt
)
2152 id
= packet_get_int();
2154 c
= channel_lookup(id
);
2156 packet_disconnect("Received ieof for nonexistent channel %d.", id
);
2159 /* XXX force input close */
2160 if (c
->force_drain
&& c
->istate
== CHAN_INPUT_OPEN
) {
2161 debug("channel %d: FORCE input drain", c
->self
);
2162 c
->istate
= CHAN_INPUT_WAIT_DRAIN
;
2163 if (buffer_len(&c
->input
) == 0)
2171 channel_input_close(int type
, u_int32_t seq
, void *ctxt
)
2176 id
= packet_get_int();
2178 c
= channel_lookup(id
);
2180 packet_disconnect("Received close for nonexistent channel %d.", id
);
2183 * Send a confirmation that we have closed the channel and no more
2184 * data is coming for it.
2186 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION
);
2187 packet_put_int(c
->remote_id
);
2191 * If the channel is in closed state, we have sent a close request,
2192 * and the other side will eventually respond with a confirmation.
2193 * Thus, we cannot free the channel here, because then there would be
2194 * no-one to receive the confirmation. The channel gets freed when
2195 * the confirmation arrives.
2197 if (c
->type
!= SSH_CHANNEL_CLOSED
) {
2199 * Not a closed channel - mark it as draining, which will
2200 * cause it to be freed later.
2202 buffer_clear(&c
->input
);
2203 c
->type
= SSH_CHANNEL_OUTPUT_DRAINING
;
2207 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2210 channel_input_oclose(int type
, u_int32_t seq
, void *ctxt
)
2212 int id
= packet_get_int();
2213 Channel
*c
= channel_lookup(id
);
2217 packet_disconnect("Received oclose for nonexistent channel %d.", id
);
2218 chan_rcvd_oclose(c
);
2223 channel_input_close_confirmation(int type
, u_int32_t seq
, void *ctxt
)
2225 int id
= packet_get_int();
2226 Channel
*c
= channel_lookup(id
);
2230 packet_disconnect("Received close confirmation for "
2231 "out-of-range channel %d.", id
);
2232 if (c
->type
!= SSH_CHANNEL_CLOSED
)
2233 packet_disconnect("Received close confirmation for "
2234 "non-closed channel %d (type %d).", id
, c
->type
);
2240 channel_input_open_confirmation(int type
, u_int32_t seq
, void *ctxt
)
2245 id
= packet_get_int();
2246 c
= channel_lookup(id
);
2248 if (c
==NULL
|| c
->type
!= SSH_CHANNEL_OPENING
)
2249 packet_disconnect("Received open confirmation for "
2250 "non-opening channel %d.", id
);
2251 remote_id
= packet_get_int();
2252 /* Record the remote channel number and mark that the channel is now open. */
2253 c
->remote_id
= remote_id
;
2254 c
->type
= SSH_CHANNEL_OPEN
;
2257 c
->remote_window
= packet_get_int();
2258 c
->remote_maxpacket
= packet_get_int();
2259 if (c
->open_confirm
) {
2260 debug2("callback start");
2261 c
->open_confirm(c
->self
, c
->open_confirm_ctx
);
2262 debug2("callback done");
2264 debug2("channel %d: open confirm rwindow %u rmax %u", c
->self
,
2265 c
->remote_window
, c
->remote_maxpacket
);
2271 reason2txt(int reason
)
2274 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED
:
2275 return "administratively prohibited";
2276 case SSH2_OPEN_CONNECT_FAILED
:
2277 return "connect failed";
2278 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE
:
2279 return "unknown channel type";
2280 case SSH2_OPEN_RESOURCE_SHORTAGE
:
2281 return "resource shortage";
2283 return "unknown reason";
2288 channel_input_open_failure(int type
, u_int32_t seq
, void *ctxt
)
2291 char *msg
= NULL
, *lang
= NULL
;
2294 id
= packet_get_int();
2295 c
= channel_lookup(id
);
2297 if (c
==NULL
|| c
->type
!= SSH_CHANNEL_OPENING
)
2298 packet_disconnect("Received open failure for "
2299 "non-opening channel %d.", id
);
2301 reason
= packet_get_int();
2302 if (!(datafellows
& SSH_BUG_OPENFAILURE
)) {
2303 msg
= packet_get_string(NULL
);
2304 lang
= packet_get_string(NULL
);
2306 logit("channel %d: open failed: %s%s%s", id
,
2307 reason2txt(reason
), msg
? ": ": "", msg
? msg
: "");
2314 /* Free the channel. This will also close the socket. */
2320 channel_input_window_adjust(int type
, u_int32_t seq
, void *ctxt
)
2329 /* Get the channel number and verify it. */
2330 id
= packet_get_int();
2331 c
= channel_lookup(id
);
2334 logit("Received window adjust for non-open channel %d.", id
);
2337 adjust
= packet_get_int();
2339 debug2("channel %d: rcvd adjust %u", id
, adjust
);
2340 c
->remote_window
+= adjust
;
2345 channel_input_port_open(int type
, u_int32_t seq
, void *ctxt
)
2349 char *host
, *originator_string
;
2352 remote_id
= packet_get_int();
2353 host
= packet_get_string(NULL
);
2354 host_port
= packet_get_int();
2356 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN
) {
2357 originator_string
= packet_get_string(NULL
);
2359 originator_string
= xstrdup("unknown (remote did not supply name)");
2362 c
= channel_connect_to(host
, host_port
,
2363 "connected socket", originator_string
);
2364 xfree(originator_string
);
2367 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
2368 packet_put_int(remote_id
);
2371 c
->remote_id
= remote_id
;
2376 channel_input_status_confirm(int type
, u_int32_t seq
, void *ctxt
)
2379 struct channel_confirm
*cc
;
2382 /* Reset keepalive timeout */
2383 keep_alive_timeouts
= 0;
2385 remote_id
= packet_get_int();
2388 debug2("channel_input_confirm: type %d id %d", type
, remote_id
);
2390 if ((c
= channel_lookup(remote_id
)) == NULL
) {
2391 logit("channel_input_success_failure: %d: unknown", remote_id
);
2395 if ((cc
= TAILQ_FIRST(&c
->status_confirms
)) == NULL
)
2397 cc
->cb(type
, c
, cc
->ctx
);
2398 TAILQ_REMOVE(&c
->status_confirms
, cc
, entry
);
2399 bzero(cc
, sizeof(*cc
));
2403 /* -- tcp forwarding */
2406 channel_set_af(int af
)
2412 channel_setup_fwd_listener(int type
, const char *listen_addr
, u_short listen_port
,
2413 const char *host_to_connect
, u_short port_to_connect
, int gateway_ports
)
2416 int sock
, r
, success
= 0, wildcard
= 0, is_client
;
2417 struct addrinfo hints
, *ai
, *aitop
;
2418 const char *host
, *addr
;
2419 char ntop
[NI_MAXHOST
], strport
[NI_MAXSERV
];
2421 host
= (type
== SSH_CHANNEL_RPORT_LISTENER
) ?
2422 listen_addr
: host_to_connect
;
2423 is_client
= (type
== SSH_CHANNEL_PORT_LISTENER
);
2426 error("No forward host name.");
2429 if (strlen(host
) > SSH_CHANNEL_PATH_LEN
- 1) {
2430 error("Forward host name too long.");
2435 * Determine whether or not a port forward listens to loopback,
2436 * specified address or wildcard. On the client, a specified bind
2437 * address will always override gateway_ports. On the server, a
2438 * gateway_ports of 1 (``yes'') will override the client's
2439 * specification and force a wildcard bind, whereas a value of 2
2440 * (``clientspecified'') will bind to whatever address the client
2443 * Special-case listen_addrs are:
2445 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2446 * "" (empty string), "*" -> wildcard v4/v6
2447 * "localhost" -> loopback v4/v6
2450 if (listen_addr
== NULL
) {
2451 /* No address specified: default to gateway_ports setting */
2454 } else if (gateway_ports
|| is_client
) {
2455 if (((datafellows
& SSH_OLD_FORWARD_ADDR
) &&
2456 strcmp(listen_addr
, "0.0.0.0") == 0 && is_client
== 0) ||
2457 *listen_addr
== '\0' || strcmp(listen_addr
, "*") == 0 ||
2458 (!is_client
&& gateway_ports
== 1))
2460 else if (strcmp(listen_addr
, "localhost") != 0)
2464 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2465 type
, wildcard
, (addr
== NULL
) ? "NULL" : addr
);
2468 * getaddrinfo returns a loopback address if the hostname is
2469 * set to NULL and hints.ai_flags is not AI_PASSIVE
2471 memset(&hints
, 0, sizeof(hints
));
2472 hints
.ai_family
= IPv4or6
;
2473 hints
.ai_flags
= wildcard
? AI_PASSIVE
: 0;
2474 hints
.ai_socktype
= SOCK_STREAM
;
2475 snprintf(strport
, sizeof strport
, "%d", listen_port
);
2476 if ((r
= getaddrinfo(addr
, strport
, &hints
, &aitop
)) != 0) {
2478 /* This really shouldn't happen */
2479 packet_disconnect("getaddrinfo: fatal error: %s",
2480 ssh_gai_strerror(r
));
2482 error("channel_setup_fwd_listener: "
2483 "getaddrinfo(%.64s): %s", addr
,
2484 ssh_gai_strerror(r
));
2489 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
2490 if (ai
->ai_family
!= AF_INET
&& ai
->ai_family
!= AF_INET6
)
2492 if (getnameinfo(ai
->ai_addr
, ai
->ai_addrlen
, ntop
, sizeof(ntop
),
2493 strport
, sizeof(strport
), NI_NUMERICHOST
|NI_NUMERICSERV
) != 0) {
2494 error("channel_setup_fwd_listener: getnameinfo failed");
2497 /* Create a port to listen for the host. */
2498 sock
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
2500 /* this is no error since kernel may not support ipv6 */
2501 verbose("socket: %.100s", strerror(errno
));
2505 channel_set_reuseaddr(sock
);
2507 debug("Local forwarding listening on %s port %s.", ntop
, strport
);
2509 /* Bind the socket to the address. */
2510 if (bind(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
2511 /* address can be in use ipv6 address is already bound */
2513 error("bind: %.100s", strerror(errno
));
2515 verbose("bind: %.100s", strerror(errno
));
2520 /* Start listening for connections on the socket. */
2521 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
2522 error("listen: %.100s", strerror(errno
));
2526 /* Allocate a channel number for the socket. */
2527 c
= channel_new("port listener", type
, sock
, sock
, -1,
2528 CHAN_TCP_WINDOW_DEFAULT
, CHAN_TCP_PACKET_DEFAULT
,
2529 0, "port listener", 1);
2530 strlcpy(c
->path
, host
, sizeof(c
->path
));
2531 c
->host_port
= port_to_connect
;
2532 c
->listening_port
= listen_port
;
2536 error("channel_setup_fwd_listener: cannot listen to port: %d",
2538 freeaddrinfo(aitop
);
2543 channel_cancel_rport_listener(const char *host
, u_short port
)
2548 for (i
= 0; i
< channels_alloc
; i
++) {
2549 Channel
*c
= channels
[i
];
2551 if (c
!= NULL
&& c
->type
== SSH_CHANNEL_RPORT_LISTENER
&&
2552 strncmp(c
->path
, host
, sizeof(c
->path
)) == 0 &&
2553 c
->listening_port
== port
) {
2554 debug2("%s: close channel %d", __func__
, i
);
2563 /* protocol local port fwd, used by ssh (and sshd in v1) */
2565 channel_setup_local_fwd_listener(const char *listen_host
, u_short listen_port
,
2566 const char *host_to_connect
, u_short port_to_connect
, int gateway_ports
)
2568 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER
,
2569 listen_host
, listen_port
, host_to_connect
, port_to_connect
,
2573 /* protocol v2 remote port fwd, used by sshd */
2575 channel_setup_remote_fwd_listener(const char *listen_address
,
2576 u_short listen_port
, int gateway_ports
)
2578 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER
,
2579 listen_address
, listen_port
, NULL
, 0, gateway_ports
);
2583 * Initiate forwarding of connections to port "port" on remote host through
2584 * the secure channel to host:port from local side.
2588 channel_request_remote_forwarding(const char *listen_host
, u_short listen_port
,
2589 const char *host_to_connect
, u_short port_to_connect
)
2591 int type
, success
= 0;
2593 /* Record locally that connection to this host/port is permitted. */
2594 if (num_permitted_opens
>= SSH_MAX_FORWARDS_PER_DIRECTION
)
2595 fatal("channel_request_remote_forwarding: too many forwards");
2597 /* Send the forward request to the remote side. */
2599 const char *address_to_bind
;
2600 if (listen_host
== NULL
) {
2601 if (datafellows
& SSH_BUG_RFWD_ADDR
)
2602 address_to_bind
= "127.0.0.1";
2604 address_to_bind
= "localhost";
2605 } else if (*listen_host
== '\0' ||
2606 strcmp(listen_host
, "*") == 0) {
2607 if (datafellows
& SSH_BUG_RFWD_ADDR
)
2608 address_to_bind
= "0.0.0.0";
2610 address_to_bind
= "";
2612 address_to_bind
= listen_host
;
2614 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
2615 packet_put_cstring("tcpip-forward");
2616 packet_put_char(1); /* boolean: want reply */
2617 packet_put_cstring(address_to_bind
);
2618 packet_put_int(listen_port
);
2620 packet_write_wait();
2621 /* Assume that server accepts the request */
2624 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST
);
2625 packet_put_int(listen_port
);
2626 packet_put_cstring(host_to_connect
);
2627 packet_put_int(port_to_connect
);
2629 packet_write_wait();
2631 /* Wait for response from the remote side. */
2632 type
= packet_read();
2634 case SSH_SMSG_SUCCESS
:
2637 case SSH_SMSG_FAILURE
:
2640 /* Unknown packet */
2641 packet_disconnect("Protocol error for port forward request:"
2642 "received packet type %d.", type
);
2646 permitted_opens
[num_permitted_opens
].host_to_connect
= xstrdup(host_to_connect
);
2647 permitted_opens
[num_permitted_opens
].port_to_connect
= port_to_connect
;
2648 permitted_opens
[num_permitted_opens
].listen_port
= listen_port
;
2649 num_permitted_opens
++;
2651 return (success
? 0 : -1);
2655 * Request cancellation of remote forwarding of connection host:port from
2659 channel_request_rforward_cancel(const char *host
, u_short port
)
2666 for (i
= 0; i
< num_permitted_opens
; i
++) {
2667 if (permitted_opens
[i
].host_to_connect
!= NULL
&&
2668 permitted_opens
[i
].listen_port
== port
)
2671 if (i
>= num_permitted_opens
) {
2672 debug("%s: requested forward not found", __func__
);
2675 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
2676 packet_put_cstring("cancel-tcpip-forward");
2678 packet_put_cstring(host
== NULL
? "" : host
);
2679 packet_put_int(port
);
2682 permitted_opens
[i
].listen_port
= 0;
2683 permitted_opens
[i
].port_to_connect
= 0;
2684 xfree(permitted_opens
[i
].host_to_connect
);
2685 permitted_opens
[i
].host_to_connect
= NULL
;
2689 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2690 * listening for the port, and sends back a success reply (or disconnect
2691 * message if there was an error).
2694 channel_input_port_forward_request(int is_root
, int gateway_ports
)
2696 u_short port
, host_port
;
2700 /* Get arguments from the packet. */
2701 port
= packet_get_int();
2702 hostname
= packet_get_string(NULL
);
2703 host_port
= packet_get_int();
2707 * Check that an unprivileged user is not trying to forward a
2710 if (port
< IPPORT_RESERVED
&& !is_root
)
2712 "Requested forwarding of port %d but user is not root.",
2715 packet_disconnect("Dynamic forwarding denied.");
2718 /* Initiate forwarding */
2719 success
= channel_setup_local_fwd_listener(NULL
, port
, hostname
,
2720 host_port
, gateway_ports
);
2722 /* Free the argument string. */
2725 return (success
? 0 : -1);
2729 * Permits opening to any host/port if permitted_opens[] is empty. This is
2730 * usually called by the server, because the user could connect to any port
2731 * anyway, and the server has no way to know but to trust the client anyway.
2734 channel_permit_all_opens(void)
2736 if (num_permitted_opens
== 0)
2737 all_opens_permitted
= 1;
2741 channel_add_permitted_opens(char *host
, int port
)
2743 if (num_permitted_opens
>= SSH_MAX_FORWARDS_PER_DIRECTION
)
2744 fatal("channel_add_permitted_opens: too many forwards");
2745 debug("allow port forwarding to host %s port %d", host
, port
);
2747 permitted_opens
[num_permitted_opens
].host_to_connect
= xstrdup(host
);
2748 permitted_opens
[num_permitted_opens
].port_to_connect
= port
;
2749 num_permitted_opens
++;
2751 all_opens_permitted
= 0;
2755 channel_add_adm_permitted_opens(char *host
, int port
)
2757 if (num_adm_permitted_opens
>= SSH_MAX_FORWARDS_PER_DIRECTION
)
2758 fatal("channel_add_adm_permitted_opens: too many forwards");
2759 debug("config allows port forwarding to host %s port %d", host
, port
);
2761 permitted_adm_opens
[num_adm_permitted_opens
].host_to_connect
2763 permitted_adm_opens
[num_adm_permitted_opens
].port_to_connect
= port
;
2764 return ++num_adm_permitted_opens
;
2768 channel_clear_permitted_opens(void)
2772 for (i
= 0; i
< num_permitted_opens
; i
++)
2773 if (permitted_opens
[i
].host_to_connect
!= NULL
)
2774 xfree(permitted_opens
[i
].host_to_connect
);
2775 num_permitted_opens
= 0;
2779 channel_clear_adm_permitted_opens(void)
2783 for (i
= 0; i
< num_adm_permitted_opens
; i
++)
2784 if (permitted_adm_opens
[i
].host_to_connect
!= NULL
)
2785 xfree(permitted_adm_opens
[i
].host_to_connect
);
2786 num_adm_permitted_opens
= 0;
2790 channel_print_adm_permitted_opens(void)
2794 for (i
= 0; i
< num_adm_permitted_opens
; i
++)
2795 if (permitted_adm_opens
[i
].host_to_connect
!= NULL
)
2796 printf(" %s:%d", permitted_adm_opens
[i
].host_to_connect
,
2797 permitted_adm_opens
[i
].port_to_connect
);
2800 /* Try to start non-blocking connect to next host in cctx list */
2802 connect_next(struct channel_connect
*cctx
)
2804 int sock
, saved_errno
;
2805 char ntop
[NI_MAXHOST
], strport
[NI_MAXSERV
];
2807 for (; cctx
->ai
; cctx
->ai
= cctx
->ai
->ai_next
) {
2808 if (cctx
->ai
->ai_family
!= AF_INET
&&
2809 cctx
->ai
->ai_family
!= AF_INET6
)
2811 if (getnameinfo(cctx
->ai
->ai_addr
, cctx
->ai
->ai_addrlen
,
2812 ntop
, sizeof(ntop
), strport
, sizeof(strport
),
2813 NI_NUMERICHOST
|NI_NUMERICSERV
) != 0) {
2814 error("connect_next: getnameinfo failed");
2817 if ((sock
= socket(cctx
->ai
->ai_family
, cctx
->ai
->ai_socktype
,
2818 cctx
->ai
->ai_protocol
)) == -1) {
2819 if (cctx
->ai
->ai_next
== NULL
)
2820 error("socket: %.100s", strerror(errno
));
2822 verbose("socket: %.100s", strerror(errno
));
2825 if (set_nonblock(sock
) == -1)
2826 fatal("%s: set_nonblock(%d)", __func__
, sock
);
2827 if (connect(sock
, cctx
->ai
->ai_addr
,
2828 cctx
->ai
->ai_addrlen
) == -1 && errno
!= EINPROGRESS
) {
2829 debug("connect_next: host %.100s ([%.100s]:%s): "
2830 "%.100s", cctx
->host
, ntop
, strport
,
2832 saved_errno
= errno
;
2834 errno
= saved_errno
;
2835 continue; /* fail -- try next */
2837 debug("connect_next: host %.100s ([%.100s]:%s) "
2838 "in progress, fd=%d", cctx
->host
, ntop
, strport
, sock
);
2839 cctx
->ai
= cctx
->ai
->ai_next
;
2847 channel_connect_ctx_free(struct channel_connect
*cctx
)
2851 freeaddrinfo(cctx
->aitop
);
2852 bzero(cctx
, sizeof(*cctx
));
2854 cctx
->ai
= cctx
->aitop
= NULL
;
2857 /* Return CONNECTING channel to remote host, port */
2859 connect_to(const char *host
, u_short port
, char *ctype
, char *rname
)
2861 struct addrinfo hints
;
2864 char strport
[NI_MAXSERV
];
2865 struct channel_connect cctx
;
2868 memset(&cctx
, 0, sizeof(cctx
));
2869 memset(&hints
, 0, sizeof(hints
));
2870 hints
.ai_family
= IPv4or6
;
2871 hints
.ai_socktype
= SOCK_STREAM
;
2872 snprintf(strport
, sizeof strport
, "%d", port
);
2873 if ((gaierr
= getaddrinfo(host
, strport
, &hints
, &cctx
.aitop
)) != 0) {
2874 error("connect_to %.100s: unknown host (%s)", host
,
2875 ssh_gai_strerror(gaierr
));
2879 cctx
.host
= xstrdup(host
);
2881 cctx
.ai
= cctx
.aitop
;
2883 if ((sock
= connect_next(&cctx
)) == -1) {
2884 error("connect to %.100s port %d failed: %s",
2885 host
, port
, strerror(errno
));
2886 channel_connect_ctx_free(&cctx
);
2889 c
= channel_new(ctype
, SSH_CHANNEL_CONNECTING
, sock
, sock
, -1,
2890 CHAN_TCP_WINDOW_DEFAULT
, CHAN_TCP_PACKET_DEFAULT
, 0, rname
, 1);
2891 c
->connect_ctx
= cctx
;
2896 channel_connect_by_listen_address(u_short listen_port
, char *ctype
, char *rname
)
2900 for (i
= 0; i
< num_permitted_opens
; i
++) {
2901 if (permitted_opens
[i
].host_to_connect
!= NULL
&&
2902 permitted_opens
[i
].listen_port
== listen_port
) {
2904 permitted_opens
[i
].host_to_connect
,
2905 permitted_opens
[i
].port_to_connect
, ctype
, rname
);
2908 error("WARNING: Server requests forwarding for unknown listen_port %d",
2913 /* Check if connecting to that port is permitted and connect. */
2915 channel_connect_to(const char *host
, u_short port
, char *ctype
, char *rname
)
2917 int i
, permit
, permit_adm
= 1;
2919 permit
= all_opens_permitted
;
2921 for (i
= 0; i
< num_permitted_opens
; i
++)
2922 if (permitted_opens
[i
].host_to_connect
!= NULL
&&
2923 permitted_opens
[i
].port_to_connect
== port
&&
2924 strcmp(permitted_opens
[i
].host_to_connect
, host
) == 0)
2928 if (num_adm_permitted_opens
> 0) {
2930 for (i
= 0; i
< num_adm_permitted_opens
; i
++)
2931 if (permitted_adm_opens
[i
].host_to_connect
!= NULL
&&
2932 permitted_adm_opens
[i
].port_to_connect
== port
&&
2933 strcmp(permitted_adm_opens
[i
].host_to_connect
, host
)
2938 if (!permit
|| !permit_adm
) {
2939 logit("Received request to connect to host %.100s port %d, "
2940 "but the request was denied.", host
, port
);
2943 return connect_to(host
, port
, ctype
, rname
);
2947 channel_send_window_changes(void)
2952 for (i
= 0; i
< channels_alloc
; i
++) {
2953 if (channels
[i
] == NULL
|| !channels
[i
]->client_tty
||
2954 channels
[i
]->type
!= SSH_CHANNEL_OPEN
)
2956 if (ioctl(channels
[i
]->rfd
, TIOCGWINSZ
, &ws
) < 0)
2958 channel_request_start(i
, "window-change", 0);
2959 packet_put_int((u_int
)ws
.ws_col
);
2960 packet_put_int((u_int
)ws
.ws_row
);
2961 packet_put_int((u_int
)ws
.ws_xpixel
);
2962 packet_put_int((u_int
)ws
.ws_ypixel
);
2967 /* -- X11 forwarding */
2970 * Creates an internet domain socket for listening for X11 connections.
2971 * Returns 0 and a suitable display number for the DISPLAY variable
2972 * stored in display_numberp , or -1 if an error occurs.
2975 x11_create_display_inet(int x11_display_offset
, int x11_use_localhost
,
2976 int single_connection
, u_int
*display_numberp
, int **chanids
)
2979 int display_number
, sock
;
2981 struct addrinfo hints
, *ai
, *aitop
;
2982 char strport
[NI_MAXSERV
];
2983 int gaierr
, n
, num_socks
= 0, socks
[NUM_SOCKS
];
2985 if (chanids
== NULL
)
2988 for (display_number
= x11_display_offset
;
2989 display_number
< MAX_DISPLAYS
;
2991 port
= 6000 + display_number
;
2992 memset(&hints
, 0, sizeof(hints
));
2993 hints
.ai_family
= IPv4or6
;
2994 hints
.ai_flags
= x11_use_localhost
? 0: AI_PASSIVE
;
2995 hints
.ai_socktype
= SOCK_STREAM
;
2996 snprintf(strport
, sizeof strport
, "%d", port
);
2997 if ((gaierr
= getaddrinfo(NULL
, strport
, &hints
, &aitop
)) != 0) {
2998 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr
));
3001 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
3002 if (ai
->ai_family
!= AF_INET
&& ai
->ai_family
!= AF_INET6
)
3004 sock
= socket(ai
->ai_family
, ai
->ai_socktype
,
3007 if ((errno
!= EINVAL
) && (errno
!= EAFNOSUPPORT
)) {
3008 error("socket: %.100s", strerror(errno
));
3009 freeaddrinfo(aitop
);
3012 debug("x11_create_display_inet: Socket family %d not supported",
3018 if (ai
->ai_family
== AF_INET6
) {
3020 if (setsockopt(sock
, IPPROTO_IPV6
, IPV6_V6ONLY
, &on
, sizeof(on
)) < 0)
3021 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno
));
3024 if (x11_use_localhost
)
3025 channel_set_reuseaddr(sock
);
3026 if (bind(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
3027 debug2("bind port %d: %.100s", port
, strerror(errno
));
3030 for (n
= 0; n
< num_socks
; n
++) {
3036 socks
[num_socks
++] = sock
;
3037 if (num_socks
== NUM_SOCKS
)
3040 freeaddrinfo(aitop
);
3044 if (display_number
>= MAX_DISPLAYS
) {
3045 error("Failed to allocate internet-domain X11 display socket.");
3048 /* Start listening for connections on the socket. */
3049 for (n
= 0; n
< num_socks
; n
++) {
3051 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
3052 error("listen: %.100s", strerror(errno
));
3058 /* Allocate a channel for each socket. */
3059 *chanids
= xcalloc(num_socks
+ 1, sizeof(**chanids
));
3060 for (n
= 0; n
< num_socks
; n
++) {
3062 nc
= channel_new("x11 listener",
3063 SSH_CHANNEL_X11_LISTENER
, sock
, sock
, -1,
3064 CHAN_X11_WINDOW_DEFAULT
, CHAN_X11_PACKET_DEFAULT
,
3065 0, "X11 inet listener", 1);
3066 nc
->single_connection
= single_connection
;
3067 (*chanids
)[n
] = nc
->self
;
3071 /* Return the display number for the DISPLAY environment variable. */
3072 *display_numberp
= display_number
;
3077 connect_local_xsocket(u_int dnr
)
3080 struct sockaddr_un addr
;
3082 sock
= socket(AF_UNIX
, SOCK_STREAM
, 0);
3084 error("socket: %.100s", strerror(errno
));
3085 memset(&addr
, 0, sizeof(addr
));
3086 addr
.sun_family
= AF_UNIX
;
3087 snprintf(addr
.sun_path
, sizeof addr
.sun_path
, _PATH_UNIX_X
, dnr
);
3088 if (connect(sock
, (struct sockaddr
*)&addr
, sizeof(addr
)) == 0)
3091 error("connect %.100s: %.100s", addr
.sun_path
, strerror(errno
));
3096 x11_connect_display(void)
3098 u_int display_number
;
3099 const char *display
;
3100 char buf
[1024], *cp
;
3101 struct addrinfo hints
, *ai
, *aitop
;
3102 char strport
[NI_MAXSERV
];
3103 int gaierr
, sock
= 0;
3105 /* Try to open a socket for the local X server. */
3106 display
= getenv("DISPLAY");
3108 error("DISPLAY not set.");
3112 * Now we decode the value of the DISPLAY variable and make a
3113 * connection to the real X server.
3117 * Check if it is a unix domain socket. Unix domain displays are in
3118 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3120 if (strncmp(display
, "unix:", 5) == 0 ||
3121 display
[0] == ':') {
3122 /* Connect to the unix domain socket. */
3123 if (sscanf(strrchr(display
, ':') + 1, "%u", &display_number
) != 1) {
3124 error("Could not parse display number from DISPLAY: %.100s",
3128 /* Create a socket. */
3129 sock
= connect_local_xsocket(display_number
);
3133 /* OK, we now have a connection to the display. */
3137 * Connect to an inet socket. The DISPLAY value is supposedly
3138 * hostname:d[.s], where hostname may also be numeric IP address.
3140 strlcpy(buf
, display
, sizeof(buf
));
3141 cp
= strchr(buf
, ':');
3143 error("Could not find ':' in DISPLAY: %.100s", display
);
3147 /* buf now contains the host name. But first we parse the display number. */
3148 if (sscanf(cp
+ 1, "%u", &display_number
) != 1) {
3149 error("Could not parse display number from DISPLAY: %.100s",
3154 /* Look up the host address */
3155 memset(&hints
, 0, sizeof(hints
));
3156 hints
.ai_family
= IPv4or6
;
3157 hints
.ai_socktype
= SOCK_STREAM
;
3158 snprintf(strport
, sizeof strport
, "%u", 6000 + display_number
);
3159 if ((gaierr
= getaddrinfo(buf
, strport
, &hints
, &aitop
)) != 0) {
3160 error("%.100s: unknown host. (%s)", buf
,
3161 ssh_gai_strerror(gaierr
));
3164 for (ai
= aitop
; ai
; ai
= ai
->ai_next
) {
3165 /* Create a socket. */
3166 sock
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
3168 debug2("socket: %.100s", strerror(errno
));
3171 /* Connect it to the display. */
3172 if (connect(sock
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
3173 debug2("connect %.100s port %u: %.100s", buf
,
3174 6000 + display_number
, strerror(errno
));
3181 freeaddrinfo(aitop
);
3183 error("connect %.100s port %u: %.100s", buf
, 6000 + display_number
,
3192 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3193 * the remote channel number. We should do whatever we want, and respond
3194 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3199 x11_input_open(int type
, u_int32_t seq
, void *ctxt
)
3202 int remote_id
, sock
= 0;
3205 debug("Received X11 open request.");
3207 remote_id
= packet_get_int();
3209 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN
) {
3210 remote_host
= packet_get_string(NULL
);
3212 remote_host
= xstrdup("unknown (remote did not supply name)");
3216 /* Obtain a connection to the real X display. */
3217 sock
= x11_connect_display();
3219 /* Allocate a channel for this connection. */
3220 c
= channel_new("connected x11 socket",
3221 SSH_CHANNEL_X11_OPEN
, sock
, sock
, -1, 0, 0, 0,
3223 c
->remote_id
= remote_id
;
3228 /* Send refusal to the remote host. */
3229 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
3230 packet_put_int(remote_id
);
3232 /* Send a confirmation to the remote host. */
3233 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION
);
3234 packet_put_int(remote_id
);
3235 packet_put_int(c
->self
);
3240 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3243 deny_input_open(int type
, u_int32_t seq
, void *ctxt
)
3245 int rchan
= packet_get_int();
3248 case SSH_SMSG_AGENT_OPEN
:
3249 error("Warning: ssh server tried agent forwarding.");
3251 case SSH_SMSG_X11_OPEN
:
3252 error("Warning: ssh server tried X11 forwarding.");
3255 error("deny_input_open: type %d", type
);
3258 error("Warning: this is probably a break-in attempt by a malicious server.");
3259 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE
);
3260 packet_put_int(rchan
);
3265 * Requests forwarding of X11 connections, generates fake authentication
3266 * data, and enables authentication spoofing.
3267 * This should be called in the client only.
3270 x11_request_forwarding_with_spoofing(int client_session_id
, const char *disp
,
3271 const char *proto
, const char *data
)
3273 u_int data_len
= (u_int
) strlen(data
) / 2;
3280 if (x11_saved_display
== NULL
)
3281 x11_saved_display
= xstrdup(disp
);
3282 else if (strcmp(disp
, x11_saved_display
) != 0) {
3283 error("x11_request_forwarding_with_spoofing: different "
3284 "$DISPLAY already forwarded");
3288 cp
= strchr(disp
, ':');
3290 cp
= strchr(cp
, '.');
3292 screen_number
= (u_int
)strtonum(cp
+ 1, 0, 400, NULL
);
3296 if (x11_saved_proto
== NULL
) {
3297 /* Save protocol name. */
3298 x11_saved_proto
= xstrdup(proto
);
3300 * Extract real authentication data and generate fake data
3301 * of the same length.
3303 x11_saved_data
= xmalloc(data_len
);
3304 x11_fake_data
= xmalloc(data_len
);
3305 for (i
= 0; i
< data_len
; i
++) {
3306 if (sscanf(data
+ 2 * i
, "%2x", &value
) != 1)
3307 fatal("x11_request_forwarding: bad "
3308 "authentication data: %.100s", data
);
3311 x11_saved_data
[i
] = value
;
3312 x11_fake_data
[i
] = rnd
& 0xff;
3315 x11_saved_data_len
= data_len
;
3316 x11_fake_data_len
= data_len
;
3319 /* Convert the fake data into hex. */
3320 new_data
= tohex(x11_fake_data
, data_len
);
3322 /* Send the request packet. */
3324 channel_request_start(client_session_id
, "x11-req", 0);
3325 packet_put_char(0); /* XXX bool single connection */
3327 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING
);
3329 packet_put_cstring(proto
);
3330 packet_put_cstring(new_data
);
3331 packet_put_int(screen_number
);
3333 packet_write_wait();
3338 /* -- agent forwarding */
3340 /* Sends a message to the server to request authentication fd forwarding. */
3343 auth_request_forwarding(void)
3345 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING
);
3347 packet_write_wait();