Annotation of src/usr.bin/ssh/channels.c, Revision 1.82
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
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.
1.49 markus 8: *
1.67 deraadt 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".
14: *
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.67 deraadt 17: * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
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.
29: *
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.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.82 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.81 2001/01/19 15:55:10 markus Exp $");
! 44:
! 45: #include <openssl/rsa.h>
! 46: #include <openssl/dsa.h>
1.1 deraadt 47:
48: #include "ssh.h"
1.82 ! markus 49: #include "ssh1.h"
! 50: #include "ssh2.h"
1.1 deraadt 51: #include "packet.h"
52: #include "xmalloc.h"
53: #include "buffer.h"
54: #include "uidswap.h"
1.82 ! markus 55: #include "log.h"
! 56: #include "misc.h"
1.14 markus 57: #include "channels.h"
58: #include "nchan.h"
59: #include "compat.h"
1.82 ! markus 60: #include "canohost.h"
1.64 markus 61: #include "key.h"
62: #include "authfd.h"
1.44 markus 63:
1.1 deraadt 64: /* Maximum number of fake X11 displays to try. */
65: #define MAX_DISPLAYS 1000
66:
1.12 markus 67: /* Max len of agent socket */
68: #define MAX_SOCKET_NAME 100
69:
1.27 markus 70: /*
71: * Pointer to an array containing all allocated channels. The array is
72: * dynamically extended as needed.
73: */
1.1 deraadt 74: static Channel *channels = NULL;
75:
1.27 markus 76: /*
77: * Size of the channel array. All slots of the array must always be
78: * initialized (at least the type field); unused slots are marked with type
79: * SSH_CHANNEL_FREE.
80: */
1.1 deraadt 81: static int channels_alloc = 0;
82:
1.27 markus 83: /*
84: * Maximum file descriptor value used in any of the channels. This is
85: * updated in channel_allocate.
86: */
1.1 deraadt 87: static int channel_max_fd_value = 0;
88:
1.12 markus 89: /* Name and directory of socket for authentication agent forwarding. */
1.1 deraadt 90: static char *channel_forwarded_auth_socket_name = NULL;
1.25 markus 91: static char *channel_forwarded_auth_socket_dir = NULL;
1.1 deraadt 92:
93: /* Saved X11 authentication protocol name. */
94: char *x11_saved_proto = NULL;
95:
96: /* Saved X11 authentication data. This is the real data. */
97: char *x11_saved_data = NULL;
1.77 markus 98: u_int x11_saved_data_len = 0;
1.1 deraadt 99:
1.27 markus 100: /*
101: * Fake X11 authentication data. This is what the server will be sending us;
102: * we should replace any occurrences of this by the real data.
103: */
1.1 deraadt 104: char *x11_fake_data = NULL;
1.77 markus 105: u_int x11_fake_data_len;
1.1 deraadt 106:
1.27 markus 107: /*
108: * Data structure for storing which hosts are permitted for forward requests.
109: * The local sides of any remote forwards are stored in this array to prevent
110: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
111: * network (which might be behind a firewall).
112: */
1.25 markus 113: typedef struct {
1.41 markus 114: char *host_to_connect; /* Connect to 'host'. */
115: u_short port_to_connect; /* Connect to 'port'. */
116: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 117: } ForwardPermission;
118:
119: /* List of all permitted host/port pairs to connect. */
120: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
121: /* Number of permitted host/port pairs in the array. */
122: static int num_permitted_opens = 0;
1.27 markus 123: /*
124: * If this is true, all opens are permitted. This is the case on the server
125: * on which we have to trust the client anyway, and the user could do
126: * anything after logging in anyway.
127: */
1.1 deraadt 128: static int all_opens_permitted = 0;
129:
130: /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
131: static int have_hostname_in_open = 0;
1.82 ! markus 132:
! 133: /* AF_UNSPEC or AF_INET or AF_INET6 */
! 134: extern int IPv4or6;
1.1 deraadt 135:
136: /* Sets specific protocol options. */
137:
1.49 markus 138: void
1.25 markus 139: channel_set_options(int hostname_in_open)
1.1 deraadt 140: {
1.25 markus 141: have_hostname_in_open = hostname_in_open;
1.1 deraadt 142: }
143:
1.27 markus 144: /*
145: * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
146: * called by the server, because the user could connect to any port anyway,
147: * and the server has no way to know but to trust the client anyway.
148: */
1.1 deraadt 149:
1.49 markus 150: void
1.25 markus 151: channel_permit_all_opens()
1.1 deraadt 152: {
1.25 markus 153: all_opens_permitted = 1;
1.1 deraadt 154: }
155:
1.41 markus 156: /* lookup channel by id */
157:
158: Channel *
159: channel_lookup(int id)
160: {
161: Channel *c;
1.63 provos 162: if (id < 0 || id > channels_alloc) {
1.41 markus 163: log("channel_lookup: %d: bad id", id);
164: return NULL;
165: }
166: c = &channels[id];
167: if (c->type == SSH_CHANNEL_FREE) {
168: log("channel_lookup: %d: bad id: channel free", id);
169: return NULL;
170: }
171: return c;
1.55 markus 172: }
173:
1.27 markus 174: /*
1.55 markus 175: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 176: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 177: */
1.1 deraadt 178:
1.52 markus 179: void
1.71 markus 180: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
181: int extusage, int nonblock)
1.1 deraadt 182: {
1.25 markus 183: /* Update the maximum file descriptor value. */
1.41 markus 184: if (rfd > channel_max_fd_value)
185: channel_max_fd_value = rfd;
186: if (wfd > channel_max_fd_value)
187: channel_max_fd_value = wfd;
188: if (efd > channel_max_fd_value)
189: channel_max_fd_value = efd;
1.27 markus 190: /* XXX set close-on-exec -markus */
1.55 markus 191:
1.52 markus 192: c->rfd = rfd;
193: c->wfd = wfd;
194: c->sock = (rfd == wfd) ? rfd : -1;
195: c->efd = efd;
196: c->extended_usage = extusage;
1.71 markus 197:
198: /* enable nonblocking mode */
199: if (nonblock) {
200: if (rfd != -1)
201: set_nonblock(rfd);
202: if (wfd != -1)
203: set_nonblock(wfd);
204: if (efd != -1)
205: set_nonblock(efd);
206: }
1.52 markus 207: }
208:
209: /*
210: * Allocate a new channel object and set its type and socket. This will cause
211: * remote_name to be freed.
212: */
213:
214: int
215: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 216: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 217: {
218: int i, found;
219: Channel *c;
1.25 markus 220:
221: /* Do initial allocation if this is the first call. */
222: if (channels_alloc == 0) {
1.44 markus 223: chan_init();
1.25 markus 224: channels_alloc = 10;
225: channels = xmalloc(channels_alloc * sizeof(Channel));
226: for (i = 0; i < channels_alloc; i++)
227: channels[i].type = SSH_CHANNEL_FREE;
1.27 markus 228: /*
229: * Kludge: arrange a call to channel_stop_listening if we
230: * terminate with fatal().
231: */
1.25 markus 232: fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
233: }
234: /* Try to find a free slot where to put the new channel. */
235: for (found = -1, i = 0; i < channels_alloc; i++)
236: if (channels[i].type == SSH_CHANNEL_FREE) {
237: /* Found a free slot. */
238: found = i;
239: break;
240: }
241: if (found == -1) {
1.27 markus 242: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 243: found = channels_alloc;
244: channels_alloc += 10;
1.70 markus 245: debug2("channel: expanding %d", channels_alloc);
1.25 markus 246: channels = xrealloc(channels, channels_alloc * sizeof(Channel));
247: for (i = found; i < channels_alloc; i++)
248: channels[i].type = SSH_CHANNEL_FREE;
249: }
250: /* Initialize and return new channel number. */
251: c = &channels[found];
252: buffer_init(&c->input);
253: buffer_init(&c->output);
1.41 markus 254: buffer_init(&c->extended);
1.25 markus 255: chan_init_iostates(c);
1.71 markus 256: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 257: c->self = found;
258: c->type = type;
1.41 markus 259: c->ctype = ctype;
1.51 markus 260: c->local_window = window;
261: c->local_window_max = window;
262: c->local_consumed = 0;
263: c->local_maxpacket = maxpack;
1.25 markus 264: c->remote_id = -1;
265: c->remote_name = remote_name;
1.41 markus 266: c->remote_window = 0;
267: c->remote_maxpacket = 0;
268: c->cb_fn = NULL;
269: c->cb_arg = NULL;
270: c->cb_event = 0;
271: c->dettach_user = NULL;
1.65 markus 272: c->input_filter = NULL;
1.25 markus 273: debug("channel %d: new [%s]", found, remote_name);
274: return found;
1.1 deraadt 275: }
1.52 markus 276: /* old interface XXX */
1.49 markus 277: int
1.41 markus 278: channel_allocate(int type, int sock, char *remote_name)
279: {
1.71 markus 280: return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
1.41 markus 281: }
1.1 deraadt 282:
1.52 markus 283:
284: /* Close all channel fd/socket. */
285:
286: void
287: channel_close_fds(Channel *c)
288: {
289: if (c->sock != -1) {
290: close(c->sock);
291: c->sock = -1;
292: }
293: if (c->rfd != -1) {
294: close(c->rfd);
295: c->rfd = -1;
296: }
297: if (c->wfd != -1) {
298: close(c->wfd);
299: c->wfd = -1;
300: }
301: if (c->efd != -1) {
302: close(c->efd);
303: c->efd = -1;
304: }
305: }
306:
307: /* Free the channel and close its fd/socket. */
1.1 deraadt 308:
1.49 markus 309: void
1.41 markus 310: channel_free(int id)
1.1 deraadt 311: {
1.41 markus 312: Channel *c = channel_lookup(id);
1.79 markus 313: char *s = channel_open_message();
314:
1.41 markus 315: if (c == NULL)
316: packet_disconnect("channel free: bad local channel %d", id);
1.79 markus 317: debug("channel_free: channel %d: status: %s", id, s);
318: xfree(s);
319:
1.44 markus 320: if (c->dettach_user != NULL) {
321: debug("channel_free: channel %d: dettaching channel user", id);
322: c->dettach_user(c->self, NULL);
323: }
1.54 markus 324: if (c->sock != -1)
325: shutdown(c->sock, SHUT_RDWR);
1.52 markus 326: channel_close_fds(c);
1.41 markus 327: buffer_free(&c->input);
328: buffer_free(&c->output);
329: buffer_free(&c->extended);
330: c->type = SSH_CHANNEL_FREE;
331: if (c->remote_name) {
332: xfree(c->remote_name);
333: c->remote_name = NULL;
1.25 markus 334: }
1.1 deraadt 335: }
336:
1.27 markus 337: /*
1.41 markus 338: * 'channel_pre*' are called just before select() to add any bits relevant to
339: * channels in the select bitmasks.
340: */
341: /*
342: * 'channel_post*': perform any appropriate operations for channels which
343: * have events pending.
1.27 markus 344: */
1.41 markus 345: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
346: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
347: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
348:
349: void
350: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
351: {
352: FD_SET(c->sock, readset);
353: }
354:
355: void
1.75 markus 356: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
357: {
358: debug3("channel %d: waiting for connection", c->self);
359: FD_SET(c->sock, writeset);
360: }
361:
362: void
1.41 markus 363: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
364: {
365: if (buffer_len(&c->input) < packet_get_maxsize())
366: FD_SET(c->sock, readset);
367: if (buffer_len(&c->output) > 0)
368: FD_SET(c->sock, writeset);
369: }
1.1 deraadt 370:
1.41 markus 371: void
372: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
373: {
374: /* test whether sockets are 'alive' for read/write */
375: if (c->istate == CHAN_INPUT_OPEN)
376: if (buffer_len(&c->input) < packet_get_maxsize())
377: FD_SET(c->sock, readset);
378: if (c->ostate == CHAN_OUTPUT_OPEN ||
379: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
380: if (buffer_len(&c->output) > 0) {
381: FD_SET(c->sock, writeset);
382: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
383: chan_obuf_empty(c);
384: }
385: }
386: }
387:
388: void
1.44 markus 389: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
390: {
391: if (c->istate == CHAN_INPUT_OPEN &&
392: c->remote_window > 0 &&
393: buffer_len(&c->input) < c->remote_window)
394: FD_SET(c->rfd, readset);
395: if (c->ostate == CHAN_OUTPUT_OPEN ||
396: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
397: if (buffer_len(&c->output) > 0) {
398: FD_SET(c->wfd, writeset);
399: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
400: chan_obuf_empty(c);
401: }
402: }
403: /** XXX check close conditions, too */
404: if (c->efd != -1) {
405: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
406: buffer_len(&c->extended) > 0)
407: FD_SET(c->efd, writeset);
408: else if (c->extended_usage == CHAN_EXTENDED_READ &&
409: buffer_len(&c->extended) < c->remote_window)
410: FD_SET(c->efd, readset);
411: }
412: }
413:
414: void
1.41 markus 415: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
416: {
417: if (buffer_len(&c->input) == 0) {
418: packet_start(SSH_MSG_CHANNEL_CLOSE);
419: packet_put_int(c->remote_id);
420: packet_send();
421: c->type = SSH_CHANNEL_CLOSED;
422: debug("Closing channel %d after input drain.", c->self);
423: }
424: }
425:
426: void
427: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
428: {
429: if (buffer_len(&c->output) == 0)
430: channel_free(c->self);
1.49 markus 431: else
1.41 markus 432: FD_SET(c->sock, writeset);
433: }
434:
435: /*
436: * This is a special state for X11 authentication spoofing. An opened X11
437: * connection (when authentication spoofing is being done) remains in this
438: * state until the first packet has been completely read. The authentication
439: * data in that packet is then substituted by the real data if it matches the
440: * fake data, and the channel is put into normal mode.
1.51 markus 441: * XXX All this happens at the client side.
1.41 markus 442: */
443: int
444: x11_open_helper(Channel *c)
1.1 deraadt 445: {
1.77 markus 446: u_char *ucp;
447: u_int proto_len, data_len;
1.25 markus 448:
1.41 markus 449: /* Check if the fixed size part of the packet is in buffer. */
450: if (buffer_len(&c->output) < 12)
451: return 0;
452:
453: /* Parse the lengths of variable-length fields. */
1.77 markus 454: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 455: if (ucp[0] == 0x42) { /* Byte order MSB first. */
456: proto_len = 256 * ucp[6] + ucp[7];
457: data_len = 256 * ucp[8] + ucp[9];
458: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
459: proto_len = ucp[6] + 256 * ucp[7];
460: data_len = ucp[8] + 256 * ucp[9];
461: } else {
462: debug("Initial X11 packet contains bad byte order byte: 0x%x",
463: ucp[0]);
464: return -1;
465: }
466:
467: /* Check if the whole packet is in buffer. */
468: if (buffer_len(&c->output) <
469: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
470: return 0;
471:
472: /* Check if authentication protocol matches. */
473: if (proto_len != strlen(x11_saved_proto) ||
474: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
475: debug("X11 connection uses different authentication protocol.");
476: return -1;
477: }
478: /* Check if authentication data matches our fake data. */
479: if (data_len != x11_fake_data_len ||
480: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
481: x11_fake_data, x11_fake_data_len) != 0) {
482: debug("X11 auth data does not match fake data.");
483: return -1;
484: }
485: /* Check fake data length */
486: if (x11_fake_data_len != x11_saved_data_len) {
487: error("X11 fake_data_len %d != saved_data_len %d",
488: x11_fake_data_len, x11_saved_data_len);
489: return -1;
490: }
491: /*
492: * Received authentication protocol and data match
493: * our fake data. Substitute the fake data with real
494: * data.
495: */
496: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
497: x11_saved_data, x11_saved_data_len);
498: return 1;
499: }
500:
501: void
502: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
503: {
504: int ret = x11_open_helper(c);
505: if (ret == 1) {
506: /* Start normal processing for the channel. */
507: c->type = SSH_CHANNEL_OPEN;
1.47 markus 508: channel_pre_open_13(c, readset, writeset);
1.41 markus 509: } else if (ret == -1) {
510: /*
511: * We have received an X11 connection that has bad
512: * authentication information.
513: */
514: log("X11 connection rejected because of wrong authentication.\r\n");
515: buffer_clear(&c->input);
516: buffer_clear(&c->output);
517: close(c->sock);
518: c->sock = -1;
519: c->type = SSH_CHANNEL_CLOSED;
520: packet_start(SSH_MSG_CHANNEL_CLOSE);
521: packet_put_int(c->remote_id);
522: packet_send();
523: }
524: }
1.25 markus 525:
1.41 markus 526: void
1.51 markus 527: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 528: {
529: int ret = x11_open_helper(c);
530: if (ret == 1) {
531: c->type = SSH_CHANNEL_OPEN;
1.57 markus 532: if (compat20)
533: channel_pre_open_20(c, readset, writeset);
534: else
535: channel_pre_open_15(c, readset, writeset);
1.41 markus 536: } else if (ret == -1) {
537: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 538: chan_read_failed(c); /** force close? */
1.41 markus 539: chan_write_failed(c);
540: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
541: }
542: }
1.25 markus 543:
1.41 markus 544: /* This is our fake X11 server socket. */
545: void
546: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
547: {
548: struct sockaddr addr;
549: int newsock, newch;
550: socklen_t addrlen;
551: char buf[16384], *remote_hostname;
1.51 markus 552: int remote_port;
1.25 markus 553:
1.41 markus 554: if (FD_ISSET(c->sock, readset)) {
555: debug("X11 connection requested.");
556: addrlen = sizeof(addr);
557: newsock = accept(c->sock, &addr, &addrlen);
558: if (newsock < 0) {
559: error("accept: %.100s", strerror(errno));
560: return;
561: }
562: remote_hostname = get_remote_hostname(newsock);
1.51 markus 563: remote_port = get_peer_port(newsock);
1.41 markus 564: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.51 markus 565: remote_hostname, remote_port);
566:
567: newch = channel_new("x11",
568: SSH_CHANNEL_OPENING, newsock, newsock, -1,
569: c->local_window_max, c->local_maxpacket,
1.71 markus 570: 0, xstrdup(buf), 1);
1.51 markus 571: if (compat20) {
572: packet_start(SSH2_MSG_CHANNEL_OPEN);
573: packet_put_cstring("x11");
574: packet_put_int(newch);
575: packet_put_int(c->local_window_max);
576: packet_put_int(c->local_maxpacket);
577: /* originator host and port */
578: packet_put_cstring(remote_hostname);
1.57 markus 579: if (datafellows & SSH_BUG_X11FWD) {
580: debug("ssh2 x11 bug compat mode");
581: } else {
582: packet_put_int(remote_port);
583: }
1.51 markus 584: packet_send();
585: } else {
586: packet_start(SSH_SMSG_X11_OPEN);
587: packet_put_int(newch);
588: if (have_hostname_in_open)
589: packet_put_string(buf, strlen(buf));
590: packet_send();
591: }
1.41 markus 592: xfree(remote_hostname);
593: }
594: }
1.25 markus 595:
1.41 markus 596: /*
597: * This socket is listening for connections to a forwarded TCP/IP port.
598: */
599: void
600: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
601: {
602: struct sockaddr addr;
603: int newsock, newch;
604: socklen_t addrlen;
1.73 markus 605: char buf[1024], *remote_hostname, *rtype;
1.41 markus 606: int remote_port;
1.25 markus 607:
1.73 markus 608: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
609: "forwarded-tcpip" : "direct-tcpip";
610:
1.41 markus 611: if (FD_ISSET(c->sock, readset)) {
612: debug("Connection to port %d forwarding "
613: "to %.100s port %d requested.",
614: c->listening_port, c->path, c->host_port);
615: addrlen = sizeof(addr);
616: newsock = accept(c->sock, &addr, &addrlen);
617: if (newsock < 0) {
618: error("accept: %.100s", strerror(errno));
619: return;
620: }
621: remote_hostname = get_remote_hostname(newsock);
622: remote_port = get_peer_port(newsock);
623: snprintf(buf, sizeof buf,
624: "listen port %d for %.100s port %d, "
625: "connect from %.200s port %d",
626: c->listening_port, c->path, c->host_port,
627: remote_hostname, remote_port);
1.73 markus 628:
629: newch = channel_new(rtype,
1.41 markus 630: SSH_CHANNEL_OPENING, newsock, newsock, -1,
631: c->local_window_max, c->local_maxpacket,
1.71 markus 632: 0, xstrdup(buf), 1);
1.44 markus 633: if (compat20) {
634: packet_start(SSH2_MSG_CHANNEL_OPEN);
1.73 markus 635: packet_put_cstring(rtype);
1.44 markus 636: packet_put_int(newch);
637: packet_put_int(c->local_window_max);
638: packet_put_int(c->local_maxpacket);
1.73 markus 639: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
640: /* listen address, port */
641: packet_put_string(c->path, strlen(c->path));
642: packet_put_int(c->listening_port);
643: } else {
644: /* target host, port */
645: packet_put_string(c->path, strlen(c->path));
646: packet_put_int(c->host_port);
647: }
1.48 markus 648: /* originator host and port */
1.44 markus 649: packet_put_cstring(remote_hostname);
650: packet_put_int(remote_port);
651: packet_send();
652: } else {
653: packet_start(SSH_MSG_PORT_OPEN);
654: packet_put_int(newch);
655: packet_put_string(c->path, strlen(c->path));
656: packet_put_int(c->host_port);
657: if (have_hostname_in_open) {
658: packet_put_string(buf, strlen(buf));
659: }
660: packet_send();
1.41 markus 661: }
662: xfree(remote_hostname);
663: }
664: }
1.25 markus 665:
1.41 markus 666: /*
667: * This is the authentication agent socket listening for connections from
668: * clients.
669: */
670: void
671: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
672: {
673: struct sockaddr addr;
674: int newsock, newch;
675: socklen_t addrlen;
1.25 markus 676:
1.41 markus 677: if (FD_ISSET(c->sock, readset)) {
678: addrlen = sizeof(addr);
679: newsock = accept(c->sock, &addr, &addrlen);
680: if (newsock < 0) {
681: error("accept from auth socket: %.100s", strerror(errno));
682: return;
683: }
1.73 markus 684: newch = channel_new("accepted auth socket",
685: SSH_CHANNEL_OPENING, newsock, newsock, -1,
686: c->local_window_max, c->local_maxpacket,
687: 0, xstrdup("accepted auth socket"), 1);
688: if (compat20) {
689: packet_start(SSH2_MSG_CHANNEL_OPEN);
690: packet_put_cstring("auth-agent@openssh.com");
691: packet_put_int(newch);
692: packet_put_int(c->local_window_max);
693: packet_put_int(c->local_maxpacket);
694: } else {
695: packet_start(SSH_SMSG_AGENT_OPEN);
696: packet_put_int(newch);
697: }
1.41 markus 698: packet_send();
699: }
700: }
1.25 markus 701:
1.75 markus 702: void
703: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
704: {
705: if (FD_ISSET(c->sock, writeset)) {
706: int err = 0;
707: int sz = sizeof(err);
708: c->type = SSH_CHANNEL_OPEN;
709: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
710: debug("getsockopt SO_ERROR failed");
711: } else {
712: if (err == 0) {
713: debug("channel %d: connected)", c->self);
714: } else {
715: debug("channel %d: not connected: %s",
716: c->self, strerror(err));
717: chan_read_failed(c);
718: chan_write_failed(c);
719: }
720: }
721: }
722: }
723:
1.41 markus 724: int
725: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
726: {
727: char buf[16*1024];
728: int len;
1.25 markus 729:
1.41 markus 730: if (c->rfd != -1 &&
731: FD_ISSET(c->rfd, readset)) {
732: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 733: if (len < 0 && (errno == EINTR || errno == EAGAIN))
734: return 1;
1.41 markus 735: if (len <= 0) {
1.51 markus 736: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 737: c->self, c->rfd, len);
1.25 markus 738: if (compat13) {
1.41 markus 739: buffer_consume(&c->output, buffer_len(&c->output));
740: c->type = SSH_CHANNEL_INPUT_DRAINING;
741: debug("Channel %d status set to input draining.", c->self);
1.25 markus 742: } else {
1.41 markus 743: chan_read_failed(c);
1.25 markus 744: }
1.41 markus 745: return -1;
746: }
1.65 markus 747: if(c->input_filter != NULL) {
1.66 markus 748: if (c->input_filter(c, buf, len) == -1) {
1.65 markus 749: debug("filter stops channel %d", c->self);
750: chan_read_failed(c);
751: }
752: } else {
753: buffer_append(&c->input, buf, len);
754: }
1.41 markus 755: }
756: return 1;
757: }
758: int
759: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
760: {
761: int len;
1.25 markus 762:
1.41 markus 763: /* Send buffered output data to the socket. */
764: if (c->wfd != -1 &&
765: FD_ISSET(c->wfd, writeset) &&
766: buffer_len(&c->output) > 0) {
767: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 768: buffer_len(&c->output));
769: if (len < 0 && (errno == EINTR || errno == EAGAIN))
770: return 1;
1.41 markus 771: if (len <= 0) {
772: if (compat13) {
773: buffer_consume(&c->output, buffer_len(&c->output));
774: debug("Channel %d status set to input draining.", c->self);
775: c->type = SSH_CHANNEL_INPUT_DRAINING;
776: } else {
777: chan_write_failed(c);
778: }
779: return -1;
1.25 markus 780: }
1.41 markus 781: buffer_consume(&c->output, len);
1.44 markus 782: if (compat20 && len > 0) {
783: c->local_consumed += len;
784: }
785: }
786: return 1;
787: }
788: int
789: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
790: {
791: char buf[16*1024];
792: int len;
793:
1.45 markus 794: /** XXX handle drain efd, too */
1.44 markus 795: if (c->efd != -1) {
796: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
797: FD_ISSET(c->efd, writeset) &&
798: buffer_len(&c->extended) > 0) {
799: len = write(c->efd, buffer_ptr(&c->extended),
800: buffer_len(&c->extended));
1.70 markus 801: debug2("channel %d: written %d to efd %d",
1.44 markus 802: c->self, len, c->efd);
803: if (len > 0) {
804: buffer_consume(&c->extended, len);
805: c->local_consumed += len;
806: }
807: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
808: FD_ISSET(c->efd, readset)) {
809: len = read(c->efd, buf, sizeof(buf));
1.70 markus 810: debug2("channel %d: read %d from efd %d",
1.44 markus 811: c->self, len, c->efd);
1.45 markus 812: if (len == 0) {
813: debug("channel %d: closing efd %d",
814: c->self, c->efd);
815: close(c->efd);
816: c->efd = -1;
817: } else if (len > 0)
1.44 markus 818: buffer_append(&c->extended, buf, len);
819: }
820: }
821: return 1;
822: }
823: int
824: channel_check_window(Channel *c, fd_set * readset, fd_set * writeset)
825: {
1.46 markus 826: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 827: c->local_window < c->local_window_max/2 &&
828: c->local_consumed > 0) {
829: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
830: packet_put_int(c->remote_id);
831: packet_put_int(c->local_consumed);
832: packet_send();
1.70 markus 833: debug2("channel %d: window %d sent adjust %d",
1.44 markus 834: c->self, c->local_window,
835: c->local_consumed);
836: c->local_window += c->local_consumed;
837: c->local_consumed = 0;
1.1 deraadt 838: }
1.41 markus 839: return 1;
1.1 deraadt 840: }
841:
1.41 markus 842: void
843: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
844: {
845: channel_handle_rfd(c, readset, writeset);
846: channel_handle_wfd(c, readset, writeset);
847: }
1.1 deraadt 848:
1.41 markus 849: void
1.44 markus 850: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
851: {
852: channel_handle_rfd(c, readset, writeset);
853: channel_handle_wfd(c, readset, writeset);
854: channel_handle_efd(c, readset, writeset);
855: channel_check_window(c, readset, writeset);
856: }
857:
858: void
1.41 markus 859: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 860: {
1.41 markus 861: int len;
862: /* Send buffered output data to the socket. */
863: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
864: len = write(c->sock, buffer_ptr(&c->output),
865: buffer_len(&c->output));
866: if (len <= 0)
867: buffer_consume(&c->output, buffer_len(&c->output));
868: else
869: buffer_consume(&c->output, len);
870: }
871: }
1.25 markus 872:
1.41 markus 873: void
1.44 markus 874: channel_handler_init_20(void)
875: {
876: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 877: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 878: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 879: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 880: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 881: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 882: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.44 markus 883:
884: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
885: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 886: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 887: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 888: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 889: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.44 markus 890: }
891:
892: void
1.41 markus 893: channel_handler_init_13(void)
894: {
895: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
896: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
897: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
898: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
899: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
900: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
901: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 902: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 903:
1.41 markus 904: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
905: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
906: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
907: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
908: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 909: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 910: }
1.25 markus 911:
1.41 markus 912: void
913: channel_handler_init_15(void)
914: {
915: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 916: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 917: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
918: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
919: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 920: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 921:
1.41 markus 922: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
923: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
924: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
925: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 926: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 927: }
1.27 markus 928:
1.41 markus 929: void
930: channel_handler_init(void)
931: {
932: int i;
933: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
934: channel_pre[i] = NULL;
935: channel_post[i] = NULL;
936: }
1.44 markus 937: if (compat20)
938: channel_handler_init_20();
939: else if (compat13)
1.41 markus 940: channel_handler_init_13();
941: else
942: channel_handler_init_15();
943: }
1.25 markus 944:
1.49 markus 945: void
1.41 markus 946: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
947: {
948: static int did_init = 0;
949: int i;
950: Channel *c;
1.25 markus 951:
1.41 markus 952: if (!did_init) {
953: channel_handler_init();
954: did_init = 1;
955: }
956: for (i = 0; i < channels_alloc; i++) {
957: c = &channels[i];
958: if (c->type == SSH_CHANNEL_FREE)
959: continue;
960: if (ftab[c->type] == NULL)
1.25 markus 961: continue;
1.41 markus 962: (*ftab[c->type])(c, readset, writeset);
1.44 markus 963: chan_delete_if_full_closed(c);
1.1 deraadt 964: }
965: }
966:
1.49 markus 967: void
1.41 markus 968: channel_prepare_select(fd_set * readset, fd_set * writeset)
969: {
970: channel_handler(channel_pre, readset, writeset);
971: }
972:
1.49 markus 973: void
1.41 markus 974: channel_after_select(fd_set * readset, fd_set * writeset)
975: {
976: channel_handler(channel_post, readset, writeset);
977: }
978:
1.1 deraadt 979: /* If there is data to send to the connection, send some of it now. */
980:
1.49 markus 981: void
1.25 markus 982: channel_output_poll()
1.1 deraadt 983: {
1.25 markus 984: int len, i;
1.41 markus 985: Channel *c;
1.1 deraadt 986:
1.25 markus 987: for (i = 0; i < channels_alloc; i++) {
1.41 markus 988: c = &channels[i];
1.37 markus 989:
1.27 markus 990: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 991: if (compat13) {
1.41 markus 992: if (c->type != SSH_CHANNEL_OPEN &&
993: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 994: continue;
995: } else {
1.41 markus 996: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 997: continue;
1.41 markus 998: if (c->istate != CHAN_INPUT_OPEN &&
999: c->istate != CHAN_INPUT_WAIT_DRAIN)
1.37 markus 1000: continue;
1001: }
1.46 markus 1002: if (compat20 &&
1003: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.44 markus 1004: debug("channel: %d: no data after CLOSE", c->self);
1005: continue;
1006: }
1.25 markus 1007:
1008: /* Get the amount of buffered data for this channel. */
1.41 markus 1009: len = buffer_len(&c->input);
1.25 markus 1010: if (len > 0) {
1.27 markus 1011: /* Send some data for the other side over the secure connection. */
1.44 markus 1012: if (compat20) {
1013: if (len > c->remote_window)
1014: len = c->remote_window;
1015: if (len > c->remote_maxpacket)
1016: len = c->remote_maxpacket;
1.25 markus 1017: } else {
1.44 markus 1018: if (packet_is_interactive()) {
1019: if (len > 1024)
1020: len = 512;
1021: } else {
1022: /* Keep the packets at reasonable size. */
1023: if (len > packet_get_maxsize()/2)
1024: len = packet_get_maxsize()/2;
1025: }
1.25 markus 1026: }
1.41 markus 1027: if (len > 0) {
1.44 markus 1028: packet_start(compat20 ?
1029: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1030: packet_put_int(c->remote_id);
1031: packet_put_string(buffer_ptr(&c->input), len);
1032: packet_send();
1033: buffer_consume(&c->input, len);
1034: c->remote_window -= len;
1035: }
1036: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1037: if (compat13)
1038: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1039: /*
1040: * input-buffer is empty and read-socket shutdown:
1041: * tell peer, that we will not send more data: send IEOF
1042: */
1.41 markus 1043: chan_ibuf_empty(c);
1.25 markus 1044: }
1.44 markus 1045: /* Send extended data, i.e. stderr */
1046: if (compat20 &&
1047: c->remote_window > 0 &&
1048: (len = buffer_len(&c->extended)) > 0 &&
1049: c->extended_usage == CHAN_EXTENDED_READ) {
1050: if (len > c->remote_window)
1051: len = c->remote_window;
1052: if (len > c->remote_maxpacket)
1053: len = c->remote_maxpacket;
1054: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1055: packet_put_int(c->remote_id);
1056: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1057: packet_put_string(buffer_ptr(&c->extended), len);
1058: packet_send();
1059: buffer_consume(&c->extended, len);
1060: c->remote_window -= len;
1061: }
1.25 markus 1062: }
1.1 deraadt 1063: }
1064:
1.27 markus 1065: /*
1066: * This is called when a packet of type CHANNEL_DATA has just been received.
1067: * The message type has already been consumed, but channel number and data is
1068: * still there.
1069: */
1.1 deraadt 1070:
1.49 markus 1071: void
1.69 markus 1072: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1073: {
1.37 markus 1074: int id;
1.25 markus 1075: char *data;
1.77 markus 1076: u_int data_len;
1.41 markus 1077: Channel *c;
1.25 markus 1078:
1079: /* Get the channel number and verify it. */
1.37 markus 1080: id = packet_get_int();
1.41 markus 1081: c = channel_lookup(id);
1082: if (c == NULL)
1.37 markus 1083: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1084:
1085: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1086: if (c->type != SSH_CHANNEL_OPEN &&
1087: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1088: return;
1089:
1090: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1091: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1092: return;
1093:
1094: /* Get the data. */
1095: data = packet_get_string(&data_len);
1.48 markus 1096: packet_done();
1.41 markus 1097:
1.44 markus 1098: if (compat20){
1099: if (data_len > c->local_maxpacket) {
1100: log("channel %d: rcvd big packet %d, maxpack %d",
1101: c->self, data_len, c->local_maxpacket);
1102: }
1103: if (data_len > c->local_window) {
1104: log("channel %d: rcvd too much data %d, win %d",
1105: c->self, data_len, c->local_window);
1106: xfree(data);
1107: return;
1108: }
1109: c->local_window -= data_len;
1110: }else{
1111: packet_integrity_check(plen, 4 + 4 + data_len, type);
1112: }
1.41 markus 1113: buffer_append(&c->output, data, data_len);
1.25 markus 1114: xfree(data);
1.1 deraadt 1115: }
1.49 markus 1116: void
1.69 markus 1117: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1118: {
1119: int id;
1120: int tcode;
1121: char *data;
1.77 markus 1122: u_int data_len;
1.44 markus 1123: Channel *c;
1124:
1125: /* Get the channel number and verify it. */
1126: id = packet_get_int();
1127: c = channel_lookup(id);
1128:
1129: if (c == NULL)
1130: packet_disconnect("Received extended_data for bad channel %d.", id);
1131: if (c->type != SSH_CHANNEL_OPEN) {
1132: log("channel %d: ext data for non open", id);
1133: return;
1134: }
1135: tcode = packet_get_int();
1136: if (c->efd == -1 ||
1137: c->extended_usage != CHAN_EXTENDED_WRITE ||
1138: tcode != SSH2_EXTENDED_DATA_STDERR) {
1139: log("channel %d: bad ext data", c->self);
1140: return;
1141: }
1142: data = packet_get_string(&data_len);
1.48 markus 1143: packet_done();
1.44 markus 1144: if (data_len > c->local_window) {
1145: log("channel %d: rcvd too much extended_data %d, win %d",
1146: c->self, data_len, c->local_window);
1147: xfree(data);
1148: return;
1149: }
1.70 markus 1150: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1151: c->local_window -= data_len;
1152: buffer_append(&c->extended, data, data_len);
1153: xfree(data);
1154: }
1155:
1.1 deraadt 1156:
1.27 markus 1157: /*
1158: * Returns true if no channel has too much buffered data, and false if one or
1159: * more channel is overfull.
1160: */
1.1 deraadt 1161:
1.49 markus 1162: int
1.25 markus 1163: channel_not_very_much_buffered_data()
1.1 deraadt 1164: {
1.77 markus 1165: u_int i;
1.41 markus 1166: Channel *c;
1.25 markus 1167:
1168: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1169: c = &channels[i];
1170: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1171: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1172: debug("channel %d: big input buffer %d",
1173: c->self, buffer_len(&c->input));
1.25 markus 1174: return 0;
1.41 markus 1175: }
1176: if (buffer_len(&c->output) > packet_get_maxsize()) {
1177: debug("channel %d: big output buffer %d",
1178: c->self, buffer_len(&c->output));
1.25 markus 1179: return 0;
1.41 markus 1180: }
1.25 markus 1181: }
1.1 deraadt 1182: }
1.25 markus 1183: return 1;
1.1 deraadt 1184: }
1185:
1.49 markus 1186: void
1.69 markus 1187: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1188: {
1189: int id;
1190: Channel *c;
1191:
1192: packet_integrity_check(plen, 4, type);
1193:
1194: id = packet_get_int();
1195: c = channel_lookup(id);
1196: if (c == NULL)
1197: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1198: chan_rcvd_ieof(c);
1199: }
1.1 deraadt 1200:
1.49 markus 1201: void
1.69 markus 1202: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1203: {
1.41 markus 1204: int id;
1205: Channel *c;
1.1 deraadt 1206:
1.41 markus 1207: packet_integrity_check(plen, 4, type);
1208:
1209: id = packet_get_int();
1210: c = channel_lookup(id);
1211: if (c == NULL)
1212: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1213:
1214: /*
1215: * Send a confirmation that we have closed the channel and no more
1216: * data is coming for it.
1217: */
1.25 markus 1218: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1219: packet_put_int(c->remote_id);
1.25 markus 1220: packet_send();
1221:
1.27 markus 1222: /*
1223: * If the channel is in closed state, we have sent a close request,
1224: * and the other side will eventually respond with a confirmation.
1225: * Thus, we cannot free the channel here, because then there would be
1226: * no-one to receive the confirmation. The channel gets freed when
1227: * the confirmation arrives.
1228: */
1.41 markus 1229: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1230: /*
1231: * Not a closed channel - mark it as draining, which will
1232: * cause it to be freed later.
1233: */
1.41 markus 1234: buffer_consume(&c->input, buffer_len(&c->input));
1235: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1236: }
1.1 deraadt 1237: }
1238:
1.41 markus 1239: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1240: void
1.69 markus 1241: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1242: {
1243: int id = packet_get_int();
1244: Channel *c = channel_lookup(id);
1245: packet_integrity_check(plen, 4, type);
1246: if (c == NULL)
1247: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1248: chan_rcvd_oclose(c);
1249: }
1.1 deraadt 1250:
1.49 markus 1251: void
1.69 markus 1252: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1253: {
1.41 markus 1254: int id = packet_get_int();
1255: Channel *c = channel_lookup(id);
1.1 deraadt 1256:
1.48 markus 1257: packet_done();
1.41 markus 1258: if (c == NULL)
1259: packet_disconnect("Received close confirmation for "
1260: "out-of-range channel %d.", id);
1261: if (c->type != SSH_CHANNEL_CLOSED)
1262: packet_disconnect("Received close confirmation for "
1263: "non-closed channel %d (type %d).", id, c->type);
1264: channel_free(c->self);
1.1 deraadt 1265: }
1266:
1.49 markus 1267: void
1.69 markus 1268: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1269: {
1.41 markus 1270: int id, remote_id;
1271: Channel *c;
1.1 deraadt 1272:
1.44 markus 1273: if (!compat20)
1274: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1275:
1.41 markus 1276: id = packet_get_int();
1277: c = channel_lookup(id);
1.25 markus 1278:
1.41 markus 1279: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1280: packet_disconnect("Received open confirmation for "
1281: "non-opening channel %d.", id);
1282: remote_id = packet_get_int();
1.27 markus 1283: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1284: c->remote_id = remote_id;
1285: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1286:
1287: if (compat20) {
1288: c->remote_window = packet_get_int();
1289: c->remote_maxpacket = packet_get_int();
1.48 markus 1290: packet_done();
1.44 markus 1291: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1292: debug2("callback start");
1.44 markus 1293: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1294: debug2("callback done");
1.44 markus 1295: }
1296: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1297: c->remote_window, c->remote_maxpacket);
1298: }
1.1 deraadt 1299: }
1300:
1.49 markus 1301: void
1.69 markus 1302: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1303: {
1.41 markus 1304: int id;
1305: Channel *c;
1306:
1.44 markus 1307: if (!compat20)
1308: packet_integrity_check(plen, 4, type);
1.41 markus 1309:
1310: id = packet_get_int();
1311: c = channel_lookup(id);
1.25 markus 1312:
1.41 markus 1313: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1314: packet_disconnect("Received open failure for "
1315: "non-opening channel %d.", id);
1.44 markus 1316: if (compat20) {
1317: int reason = packet_get_int();
1318: char *msg = packet_get_string(NULL);
1.48 markus 1319: char *lang = packet_get_string(NULL);
1.44 markus 1320: log("channel_open_failure: %d: reason %d: %s", id, reason, msg);
1.48 markus 1321: packet_done();
1.44 markus 1322: xfree(msg);
1.48 markus 1323: xfree(lang);
1.44 markus 1324: }
1.25 markus 1325: /* Free the channel. This will also close the socket. */
1.41 markus 1326: channel_free(id);
1.1 deraadt 1327: }
1328:
1.44 markus 1329: void
1.69 markus 1330: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1331: {
1332: int id;
1333: Channel *c;
1334:
1335: id = packet_get_int();
1336: c = channel_lookup(id);
1337:
1338: if (c == NULL ||
1339: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1340: packet_disconnect("Received request for "
1341: "non-open channel %d.", id);
1342: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1343: debug2("callback start");
1.44 markus 1344: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1345: debug2("callback done");
1.44 markus 1346: } else {
1347: char *service = packet_get_string(NULL);
1348: debug("channel: %d rcvd request for %s", c->self, service);
1.70 markus 1349: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1350: xfree(service);
1351: }
1352: }
1353:
1.49 markus 1354: void
1.69 markus 1355: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1356: {
1357: Channel *c;
1358: int id, adjust;
1359:
1360: if (!compat20)
1361: return;
1362:
1363: /* Get the channel number and verify it. */
1364: id = packet_get_int();
1365: c = channel_lookup(id);
1366:
1367: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1368: log("Received window adjust for "
1369: "non-open channel %d.", id);
1370: return;
1371: }
1372: adjust = packet_get_int();
1.48 markus 1373: packet_done();
1.70 markus 1374: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1375: c->remote_window += adjust;
1376: }
1377:
1.27 markus 1378: /*
1379: * Stops listening for channels, and removes any unix domain sockets that we
1380: * might have.
1381: */
1.1 deraadt 1382:
1.49 markus 1383: void
1.25 markus 1384: channel_stop_listening()
1.1 deraadt 1385: {
1.25 markus 1386: int i;
1387: for (i = 0; i < channels_alloc; i++) {
1388: switch (channels[i].type) {
1389: case SSH_CHANNEL_AUTH_SOCKET:
1390: close(channels[i].sock);
1.76 markus 1391: unlink(channels[i].path);
1.25 markus 1392: channel_free(i);
1393: break;
1394: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1395: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1396: case SSH_CHANNEL_X11_LISTENER:
1397: close(channels[i].sock);
1398: channel_free(i);
1399: break;
1400: default:
1401: break;
1402: }
1.1 deraadt 1403: }
1404: }
1405:
1.27 markus 1406: /*
1.52 markus 1407: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1408: * descriptors after a fork.
1409: */
1.1 deraadt 1410:
1.49 markus 1411: void
1.25 markus 1412: channel_close_all()
1.1 deraadt 1413: {
1.25 markus 1414: int i;
1.52 markus 1415: for (i = 0; i < channels_alloc; i++)
1.25 markus 1416: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1417: channel_close_fds(&channels[i]);
1.1 deraadt 1418: }
1419:
1420: /* Returns the maximum file descriptor number used by the channels. */
1421:
1.49 markus 1422: int
1.25 markus 1423: channel_max_fd()
1.1 deraadt 1424: {
1.25 markus 1425: return channel_max_fd_value;
1.1 deraadt 1426: }
1427:
1428: /* Returns true if any channel is still open. */
1429:
1.49 markus 1430: int
1.25 markus 1431: channel_still_open()
1.1 deraadt 1432: {
1.77 markus 1433: u_int i;
1.25 markus 1434: for (i = 0; i < channels_alloc; i++)
1435: switch (channels[i].type) {
1436: case SSH_CHANNEL_FREE:
1437: case SSH_CHANNEL_X11_LISTENER:
1438: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1439: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1440: case SSH_CHANNEL_CLOSED:
1441: case SSH_CHANNEL_AUTH_SOCKET:
1.75 markus 1442: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1443: continue;
1.44 markus 1444: case SSH_CHANNEL_LARVAL:
1445: if (!compat20)
1446: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1447: continue;
1.25 markus 1448: case SSH_CHANNEL_OPENING:
1449: case SSH_CHANNEL_OPEN:
1450: case SSH_CHANNEL_X11_OPEN:
1451: return 1;
1452: case SSH_CHANNEL_INPUT_DRAINING:
1453: case SSH_CHANNEL_OUTPUT_DRAINING:
1454: if (!compat13)
1455: fatal("cannot happen: OUT_DRAIN");
1456: return 1;
1457: default:
1458: fatal("channel_still_open: bad channel type %d", channels[i].type);
1459: /* NOTREACHED */
1460: }
1461: return 0;
1.1 deraadt 1462: }
1463:
1.27 markus 1464: /*
1465: * Returns a message describing the currently open forwarded connections,
1466: * suitable for sending to the client. The message contains crlf pairs for
1467: * newlines.
1468: */
1.1 deraadt 1469:
1.25 markus 1470: char *
1471: channel_open_message()
1.1 deraadt 1472: {
1.25 markus 1473: Buffer buffer;
1474: int i;
1475: char buf[512], *cp;
1476:
1477: buffer_init(&buffer);
1478: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1479: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1480: for (i = 0; i < channels_alloc; i++) {
1481: Channel *c = &channels[i];
1482: switch (c->type) {
1483: case SSH_CHANNEL_FREE:
1484: case SSH_CHANNEL_X11_LISTENER:
1485: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1486: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1487: case SSH_CHANNEL_CLOSED:
1488: case SSH_CHANNEL_AUTH_SOCKET:
1489: continue;
1.44 markus 1490: case SSH_CHANNEL_LARVAL:
1.25 markus 1491: case SSH_CHANNEL_OPENING:
1.75 markus 1492: case SSH_CHANNEL_CONNECTING:
1.25 markus 1493: case SSH_CHANNEL_OPEN:
1494: case SSH_CHANNEL_X11_OPEN:
1495: case SSH_CHANNEL_INPUT_DRAINING:
1496: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1497: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1498: c->self, c->remote_name,
1499: c->type, c->remote_id,
1500: c->istate, buffer_len(&c->input),
1.41 markus 1501: c->ostate, buffer_len(&c->output),
1502: c->rfd, c->wfd);
1.25 markus 1503: buffer_append(&buffer, buf, strlen(buf));
1504: continue;
1505: default:
1.41 markus 1506: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1507: /* NOTREACHED */
1508: }
1509: }
1510: buffer_append(&buffer, "\0", 1);
1511: cp = xstrdup(buffer_ptr(&buffer));
1512: buffer_free(&buffer);
1513: return cp;
1.1 deraadt 1514: }
1515:
1.27 markus 1516: /*
1517: * Initiate forwarding of connections to local port "port" through the secure
1518: * channel to host:port from remote side.
1519: */
1.73 markus 1520: void
1521: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1522: u_short port_to_connect, int gateway_ports)
1523: {
1524: channel_request_forwarding(
1525: NULL, listen_port,
1526: host_to_connect, port_to_connect,
1527: gateway_ports, /*remote_fwd*/ 0);
1528: }
1.1 deraadt 1529:
1.73 markus 1530: /*
1531: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1532: * (SSH_CHANNEL_RPORT_LISTENER).
1533: */
1.49 markus 1534: void
1.73 markus 1535: channel_request_forwarding(
1536: const char *listen_address, u_short listen_port,
1537: const char *host_to_connect, u_short port_to_connect,
1538: int gateway_ports, int remote_fwd)
1.25 markus 1539: {
1.73 markus 1540: int success, ch, sock, on = 1, ctype;
1.35 markus 1541: struct addrinfo hints, *ai, *aitop;
1542: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1543: const char *host;
1.28 markus 1544: struct linger linger;
1.25 markus 1545:
1.73 markus 1546: if (remote_fwd) {
1547: host = listen_address;
1548: ctype = SSH_CHANNEL_RPORT_LISTENER;
1549: } else {
1550: host = host_to_connect;
1551: ctype =SSH_CHANNEL_PORT_LISTENER;
1552: }
1553:
1.25 markus 1554: if (strlen(host) > sizeof(channels[0].path) - 1)
1555: packet_disconnect("Forward host name too long.");
1556:
1.73 markus 1557: /* XXX listen_address is currently ignored */
1.28 markus 1558: /*
1.35 markus 1559: * getaddrinfo returns a loopback address if the hostname is
1560: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1561: */
1.35 markus 1562: memset(&hints, 0, sizeof(hints));
1563: hints.ai_family = IPv4or6;
1564: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1565: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1566: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1567: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1568: packet_disconnect("getaddrinfo: fatal error");
1569:
1570: success = 0;
1571: for (ai = aitop; ai; ai = ai->ai_next) {
1572: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1573: continue;
1574: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1575: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1576: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1577: continue;
1578: }
1579: /* Create a port to listen for the host. */
1580: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1581: if (sock < 0) {
1582: /* this is no error since kernel may not support ipv6 */
1583: verbose("socket: %.100s", strerror(errno));
1584: continue;
1585: }
1586: /*
1587: * Set socket options. We would like the socket to disappear
1588: * as soon as it has been closed for whatever reason.
1589: */
1590: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1591: linger.l_onoff = 1;
1592: linger.l_linger = 5;
1593: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1594: debug("Local forwarding listening on %s port %s.", ntop, strport);
1595:
1596: /* Bind the socket to the address. */
1597: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1598: /* address can be in use ipv6 address is already bound */
1599: verbose("bind: %.100s", strerror(errno));
1600: close(sock);
1601: continue;
1602: }
1603: /* Start listening for connections on the socket. */
1604: if (listen(sock, 5) < 0) {
1605: error("listen: %.100s", strerror(errno));
1606: close(sock);
1607: continue;
1608: }
1609: /* Allocate a channel number for the socket. */
1.73 markus 1610: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1611: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1612: 0, xstrdup("port listener"), 1);
1.35 markus 1613: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1614: channels[ch].host_port = port_to_connect;
1615: channels[ch].listening_port = listen_port;
1.35 markus 1616: success = 1;
1617: }
1618: if (success == 0)
1.73 markus 1619: packet_disconnect("cannot listen port: %d", listen_port); /*XXX ?disconnect? */
1.35 markus 1620: freeaddrinfo(aitop);
1.25 markus 1621: }
1.1 deraadt 1622:
1.27 markus 1623: /*
1624: * Initiate forwarding of connections to port "port" on remote host through
1625: * the secure channel to host:port from local side.
1626: */
1.1 deraadt 1627:
1.49 markus 1628: void
1.73 markus 1629: channel_request_remote_forwarding(u_short listen_port,
1630: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1631: {
1.73 markus 1632: int payload_len, type, success = 0;
1633:
1.25 markus 1634: /* Record locally that connection to this host/port is permitted. */
1635: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1636: fatal("channel_request_remote_forwarding: too many forwards");
1637:
1638: /* Send the forward request to the remote side. */
1.44 markus 1639: if (compat20) {
1640: const char *address_to_bind = "0.0.0.0";
1641: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1642: packet_put_cstring("tcpip-forward");
1643: packet_put_char(0); /* boolean: want reply */
1644: packet_put_cstring(address_to_bind);
1645: packet_put_int(listen_port);
1.73 markus 1646: packet_send();
1647: packet_write_wait();
1648: /* Assume that server accepts the request */
1649: success = 1;
1.44 markus 1650: } else {
1651: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1652: packet_put_int(listen_port);
1653: packet_put_cstring(host_to_connect);
1.44 markus 1654: packet_put_int(port_to_connect);
1655: packet_send();
1656: packet_write_wait();
1.73 markus 1657:
1658: /* Wait for response from the remote side. */
1659: type = packet_read(&payload_len);
1660: switch (type) {
1661: case SSH_SMSG_SUCCESS:
1662: success = 1;
1663: break;
1664: case SSH_SMSG_FAILURE:
1665: log("Warning: Server denied remote port forwarding.");
1666: break;
1667: default:
1668: /* Unknown packet */
1669: packet_disconnect("Protocol error for port forward request:"
1670: "received packet type %d.", type);
1671: }
1672: }
1673: if (success) {
1674: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1675: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1676: permitted_opens[num_permitted_opens].listen_port = listen_port;
1677: num_permitted_opens++;
1.44 markus 1678: }
1.1 deraadt 1679: }
1680:
1.27 markus 1681: /*
1682: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1683: * listening for the port, and sends back a success reply (or disconnect
1684: * message if there was an error). This never returns if there was an error.
1685: */
1.1 deraadt 1686:
1.49 markus 1687: void
1.56 markus 1688: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1689: {
1.31 markus 1690: u_short port, host_port;
1.25 markus 1691: char *hostname;
1.1 deraadt 1692:
1.25 markus 1693: /* Get arguments from the packet. */
1694: port = packet_get_int();
1695: hostname = packet_get_string(NULL);
1696: host_port = packet_get_int();
1697:
1.27 markus 1698: /*
1699: * Check that an unprivileged user is not trying to forward a
1700: * privileged port.
1701: */
1.25 markus 1702: if (port < IPPORT_RESERVED && !is_root)
1703: packet_disconnect("Requested forwarding of port %d but user is not root.",
1704: port);
1.73 markus 1705: /* Initiate forwarding */
1.56 markus 1706: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1707:
1708: /* Free the argument string. */
1709: xfree(hostname);
1.1 deraadt 1710: }
1711:
1.41 markus 1712: /* XXX move to aux.c */
1713: int
1714: channel_connect_to(const char *host, u_short host_port)
1715: {
1716: struct addrinfo hints, *ai, *aitop;
1717: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1718: int gaierr;
1719: int sock = -1;
1720:
1721: memset(&hints, 0, sizeof(hints));
1722: hints.ai_family = IPv4or6;
1723: hints.ai_socktype = SOCK_STREAM;
1724: snprintf(strport, sizeof strport, "%d", host_port);
1725: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1726: error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
1727: return -1;
1728: }
1729: for (ai = aitop; ai; ai = ai->ai_next) {
1730: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1731: continue;
1732: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1733: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1734: error("channel_connect_to: getnameinfo failed");
1735: continue;
1736: }
1737: /* Create the socket. */
1738: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1739: if (sock < 0) {
1740: error("socket: %.100s", strerror(errno));
1741: continue;
1742: }
1.80 markus 1743: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1744: fatal("connect_to: F_SETFL: %s", strerror(errno));
1.41 markus 1745: /* Connect to the host/port. */
1.75 markus 1746: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1747: errno != EINPROGRESS) {
1.41 markus 1748: error("connect %.100s port %s: %.100s", ntop, strport,
1749: strerror(errno));
1750: close(sock);
1751: continue; /* fail -- try next */
1752: }
1753: break; /* success */
1754:
1755: }
1756: freeaddrinfo(aitop);
1757: if (!ai) {
1758: error("connect %.100s port %d: failed.", host, host_port);
1759: return -1;
1760: }
1761: /* success */
1762: return sock;
1763: }
1.73 markus 1764: int
1765: channel_connect_by_listen_adress(u_short listen_port)
1766: {
1767: int i;
1768: for (i = 0; i < num_permitted_opens; i++)
1769: if (permitted_opens[i].listen_port == listen_port)
1770: return channel_connect_to(
1771: permitted_opens[i].host_to_connect,
1772: permitted_opens[i].port_to_connect);
1.74 markus 1773: error("WARNING: Server requests forwarding for unknown listen_port %d",
1774: listen_port);
1.73 markus 1775: return -1;
1776: }
1777:
1.27 markus 1778: /*
1779: * This is called after receiving PORT_OPEN message. This attempts to
1780: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
1781: * or CHANNEL_OPEN_FAILURE.
1782: */
1.1 deraadt 1783:
1.49 markus 1784: void
1.69 markus 1785: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1786: {
1.31 markus 1787: u_short host_port;
1.25 markus 1788: char *host, *originator_string;
1.41 markus 1789: int remote_channel, sock = -1, newch, i, denied;
1.77 markus 1790: u_int host_len, originator_len;
1.25 markus 1791:
1792: /* Get remote channel number. */
1793: remote_channel = packet_get_int();
1794:
1795: /* Get host name to connect to. */
1796: host = packet_get_string(&host_len);
1797:
1798: /* Get port to connect to. */
1799: host_port = packet_get_int();
1800:
1801: /* Get remote originator name. */
1.29 markus 1802: if (have_hostname_in_open) {
1.25 markus 1803: originator_string = packet_get_string(&originator_len);
1.29 markus 1804: originator_len += 4; /* size of packet_int */
1805: } else {
1.25 markus 1806: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 1807: originator_len = 0; /* no originator supplied */
1808: }
1.25 markus 1809:
1.41 markus 1810: packet_integrity_check(plen,
1811: 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
1.25 markus 1812:
1813: /* Check if opening that port is permitted. */
1.41 markus 1814: denied = 0;
1.25 markus 1815: if (!all_opens_permitted) {
1816: /* Go trough all permitted ports. */
1817: for (i = 0; i < num_permitted_opens; i++)
1.41 markus 1818: if (permitted_opens[i].port_to_connect == host_port &&
1819: strcmp(permitted_opens[i].host_to_connect, host) == 0)
1.25 markus 1820: break;
1821:
1822: /* Check if we found the requested port among those permitted. */
1823: if (i >= num_permitted_opens) {
1824: /* The port is not permitted. */
1825: log("Received request to connect to %.100s:%d, but the request was denied.",
1826: host, host_port);
1.41 markus 1827: denied = 1;
1.25 markus 1828: }
1829: }
1.41 markus 1830: sock = denied ? -1 : channel_connect_to(host, host_port);
1831: if (sock > 0) {
1832: /* Allocate a channel for this connection. */
1.75 markus 1833: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
1834: sock, originator_string);
1835: /*XXX delay answer? */
1.41 markus 1836: channels[newch].remote_id = remote_channel;
1837:
1838: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1839: packet_put_int(remote_channel);
1840: packet_put_int(newch);
1841: packet_send();
1842: } else {
1843: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1844: packet_put_int(remote_channel);
1845: packet_send();
1.25 markus 1846: }
1847: xfree(host);
1.1 deraadt 1848: }
1849:
1.27 markus 1850: /*
1851: * Creates an internet domain socket for listening for X11 connections.
1852: * Returns a suitable value for the DISPLAY variable, or NULL if an error
1853: * occurs.
1854: */
1.1 deraadt 1855:
1.35 markus 1856: #define NUM_SOCKS 10
1857:
1.25 markus 1858: char *
1.33 markus 1859: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 1860: {
1.31 markus 1861: int display_number, sock;
1862: u_short port;
1.35 markus 1863: struct addrinfo hints, *ai, *aitop;
1864: char strport[NI_MAXSERV];
1865: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1866: char display[512];
1.25 markus 1867: char hostname[MAXHOSTNAMELEN];
1868:
1.33 markus 1869: for (display_number = x11_display_offset;
1.25 markus 1870: display_number < MAX_DISPLAYS;
1871: display_number++) {
1872: port = 6000 + display_number;
1.35 markus 1873: memset(&hints, 0, sizeof(hints));
1874: hints.ai_family = IPv4or6;
1.36 markus 1875: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 1876: hints.ai_socktype = SOCK_STREAM;
1877: snprintf(strport, sizeof strport, "%d", port);
1878: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1879: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 1880: return NULL;
1881: }
1.35 markus 1882: for (ai = aitop; ai; ai = ai->ai_next) {
1883: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1884: continue;
1885: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1886: if (sock < 0) {
1887: error("socket: %.100s", strerror(errno));
1888: return NULL;
1889: }
1890: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1891: debug("bind port %d: %.100s", port, strerror(errno));
1892: shutdown(sock, SHUT_RDWR);
1893: close(sock);
1894: for (n = 0; n < num_socks; n++) {
1895: shutdown(socks[n], SHUT_RDWR);
1896: close(socks[n]);
1897: }
1898: num_socks = 0;
1899: break;
1900: }
1901: socks[num_socks++] = sock;
1902: if (num_socks == NUM_SOCKS)
1903: break;
1.25 markus 1904: }
1.35 markus 1905: if (num_socks > 0)
1906: break;
1.25 markus 1907: }
1908: if (display_number >= MAX_DISPLAYS) {
1909: error("Failed to allocate internet-domain X11 display socket.");
1910: return NULL;
1911: }
1912: /* Start listening for connections on the socket. */
1.35 markus 1913: for (n = 0; n < num_socks; n++) {
1914: sock = socks[n];
1915: if (listen(sock, 5) < 0) {
1916: error("listen: %.100s", strerror(errno));
1917: shutdown(sock, SHUT_RDWR);
1918: close(sock);
1919: return NULL;
1920: }
1.25 markus 1921: }
1.35 markus 1922:
1.25 markus 1923: /* Set up a suitable value for the DISPLAY variable. */
1924: if (gethostname(hostname, sizeof(hostname)) < 0)
1925: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 1926: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 1927: display_number, screen_number);
1928:
1.35 markus 1929: /* Allocate a channel for each socket. */
1930: for (n = 0; n < num_socks; n++) {
1931: sock = socks[n];
1.51 markus 1932: (void) channel_new("x11 listener",
1933: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
1934: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 1935: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 1936: }
1.1 deraadt 1937:
1.25 markus 1938: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 1939: return xstrdup(display);
1.1 deraadt 1940: }
1941:
1942: #ifndef X_UNIX_PATH
1943: #define X_UNIX_PATH "/tmp/.X11-unix/X"
1944: #endif
1945:
1946: static
1947: int
1.77 markus 1948: connect_local_xsocket(u_int dnr)
1.1 deraadt 1949: {
1.25 markus 1950: static const char *const x_sockets[] = {
1951: X_UNIX_PATH "%u",
1952: "/var/X/.X11-unix/X" "%u",
1953: "/usr/spool/sockets/X11/" "%u",
1954: NULL
1955: };
1956: int sock;
1957: struct sockaddr_un addr;
1958: const char *const * path;
1959:
1960: for (path = x_sockets; *path; ++path) {
1961: sock = socket(AF_UNIX, SOCK_STREAM, 0);
1962: if (sock < 0)
1963: error("socket: %.100s", strerror(errno));
1964: memset(&addr, 0, sizeof(addr));
1965: addr.sun_family = AF_UNIX;
1966: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
1967: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
1968: return sock;
1969: close(sock);
1970: }
1971: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
1972: return -1;
1.1 deraadt 1973: }
1974:
1.51 markus 1975: int
1976: x11_connect_display(void)
1.1 deraadt 1977: {
1.51 markus 1978: int display_number, sock = 0;
1.25 markus 1979: const char *display;
1.51 markus 1980: char buf[1024], *cp;
1.35 markus 1981: struct addrinfo hints, *ai, *aitop;
1982: char strport[NI_MAXSERV];
1983: int gaierr;
1.25 markus 1984:
1985: /* Try to open a socket for the local X server. */
1986: display = getenv("DISPLAY");
1987: if (!display) {
1988: error("DISPLAY not set.");
1.51 markus 1989: return -1;
1.25 markus 1990: }
1.27 markus 1991: /*
1992: * Now we decode the value of the DISPLAY variable and make a
1993: * connection to the real X server.
1994: */
1995:
1996: /*
1997: * Check if it is a unix domain socket. Unix domain displays are in
1998: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
1999: */
1.25 markus 2000: if (strncmp(display, "unix:", 5) == 0 ||
2001: display[0] == ':') {
2002: /* Connect to the unix domain socket. */
2003: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2004: error("Could not parse display number from DISPLAY: %.100s",
2005: display);
1.51 markus 2006: return -1;
1.25 markus 2007: }
2008: /* Create a socket. */
2009: sock = connect_local_xsocket(display_number);
2010: if (sock < 0)
1.51 markus 2011: return -1;
1.25 markus 2012:
2013: /* OK, we now have a connection to the display. */
1.51 markus 2014: return sock;
1.25 markus 2015: }
1.27 markus 2016: /*
2017: * Connect to an inet socket. The DISPLAY value is supposedly
2018: * hostname:d[.s], where hostname may also be numeric IP address.
2019: */
1.25 markus 2020: strncpy(buf, display, sizeof(buf));
2021: buf[sizeof(buf) - 1] = 0;
2022: cp = strchr(buf, ':');
2023: if (!cp) {
2024: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2025: return -1;
1.25 markus 2026: }
2027: *cp = 0;
1.27 markus 2028: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2029: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2030: error("Could not parse display number from DISPLAY: %.100s",
2031: display);
1.51 markus 2032: return -1;
1.25 markus 2033: }
1.35 markus 2034:
2035: /* Look up the host address */
2036: memset(&hints, 0, sizeof(hints));
2037: hints.ai_family = IPv4or6;
2038: hints.ai_socktype = SOCK_STREAM;
2039: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2040: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2041: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2042: return -1;
1.25 markus 2043: }
1.35 markus 2044: for (ai = aitop; ai; ai = ai->ai_next) {
2045: /* Create a socket. */
2046: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2047: if (sock < 0) {
2048: debug("socket: %.100s", strerror(errno));
1.41 markus 2049: continue;
2050: }
2051: /* Connect it to the display. */
2052: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2053: debug("connect %.100s port %d: %.100s", buf,
2054: 6000 + display_number, strerror(errno));
2055: close(sock);
2056: continue;
2057: }
2058: /* Success */
2059: break;
1.35 markus 2060: }
2061: freeaddrinfo(aitop);
2062: if (!ai) {
1.49 markus 2063: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2064: strerror(errno));
1.51 markus 2065: return -1;
1.25 markus 2066: }
1.51 markus 2067: return sock;
2068: }
2069:
2070: /*
2071: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2072: * the remote channel number. We should do whatever we want, and respond
2073: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2074: */
2075:
2076: void
1.69 markus 2077: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2078: {
2079: int remote_channel, sock = 0, newch;
2080: char *remote_host;
1.77 markus 2081: u_int remote_len;
1.25 markus 2082:
1.51 markus 2083: /* Get remote channel number. */
2084: remote_channel = packet_get_int();
2085:
2086: /* Get remote originator name. */
2087: if (have_hostname_in_open) {
2088: remote_host = packet_get_string(&remote_len);
2089: remote_len += 4;
2090: } else {
2091: remote_host = xstrdup("unknown (remote did not supply name)");
2092: remote_len = 0;
2093: }
1.25 markus 2094:
1.51 markus 2095: debug("Received X11 open request.");
2096: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2097:
1.51 markus 2098: /* Obtain a connection to the real X display. */
2099: sock = x11_connect_display();
2100: if (sock == -1) {
2101: /* Send refusal to the remote host. */
2102: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2103: packet_put_int(remote_channel);
2104: packet_send();
2105: } else {
2106: /* Allocate a channel for this connection. */
2107: newch = channel_allocate(
2108: (x11_saved_proto == NULL) ?
2109: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2110: sock, remote_host);
2111: channels[newch].remote_id = remote_channel;
1.25 markus 2112:
1.51 markus 2113: /* Send a confirmation to the remote host. */
2114: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2115: packet_put_int(remote_channel);
2116: packet_put_int(newch);
2117: packet_send();
2118: }
1.72 markus 2119: }
2120:
2121: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2122: void
2123: deny_input_open(int type, int plen, void *ctxt)
2124: {
2125: int rchan = packet_get_int();
2126: switch(type){
2127: case SSH_SMSG_AGENT_OPEN:
2128: error("Warning: ssh server tried agent forwarding.");
2129: break;
2130: case SSH_SMSG_X11_OPEN:
2131: error("Warning: ssh server tried X11 forwarding.");
2132: break;
2133: default:
2134: error("deny_input_open: type %d plen %d", type, plen);
2135: break;
2136: }
2137: error("Warning: this is probably a break in attempt by a malicious server.");
2138: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2139: packet_put_int(rchan);
2140: packet_send();
1.1 deraadt 2141: }
2142:
1.27 markus 2143: /*
2144: * Requests forwarding of X11 connections, generates fake authentication
2145: * data, and enables authentication spoofing.
2146: */
1.1 deraadt 2147:
1.49 markus 2148: void
1.51 markus 2149: x11_request_forwarding_with_spoofing(int client_session_id,
2150: const char *proto, const char *data)
1.1 deraadt 2151: {
1.77 markus 2152: u_int data_len = (u_int) strlen(data) / 2;
2153: u_int i, value;
1.25 markus 2154: char *new_data;
2155: int screen_number;
2156: const char *cp;
2157: u_int32_t rand = 0;
2158:
2159: cp = getenv("DISPLAY");
2160: if (cp)
2161: cp = strchr(cp, ':');
2162: if (cp)
2163: cp = strchr(cp, '.');
2164: if (cp)
2165: screen_number = atoi(cp + 1);
2166: else
2167: screen_number = 0;
2168:
2169: /* Save protocol name. */
2170: x11_saved_proto = xstrdup(proto);
2171:
1.27 markus 2172: /*
2173: * Extract real authentication data and generate fake data of the
2174: * same length.
2175: */
1.25 markus 2176: x11_saved_data = xmalloc(data_len);
2177: x11_fake_data = xmalloc(data_len);
2178: for (i = 0; i < data_len; i++) {
2179: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2180: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2181: if (i % 4 == 0)
2182: rand = arc4random();
2183: x11_saved_data[i] = value;
2184: x11_fake_data[i] = rand & 0xff;
2185: rand >>= 8;
2186: }
2187: x11_saved_data_len = data_len;
2188: x11_fake_data_len = data_len;
2189:
2190: /* Convert the fake data into hex. */
2191: new_data = xmalloc(2 * data_len + 1);
2192: for (i = 0; i < data_len; i++)
1.77 markus 2193: sprintf(new_data + 2 * i, "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2194:
2195: /* Send the request packet. */
1.51 markus 2196: if (compat20) {
2197: channel_request_start(client_session_id, "x11-req", 0);
2198: packet_put_char(0); /* XXX bool single connection */
2199: } else {
2200: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2201: }
2202: packet_put_cstring(proto);
2203: packet_put_cstring(new_data);
1.25 markus 2204: packet_put_int(screen_number);
2205: packet_send();
2206: packet_write_wait();
2207: xfree(new_data);
1.1 deraadt 2208: }
2209:
2210: /* Sends a message to the server to request authentication fd forwarding. */
2211:
1.49 markus 2212: void
1.25 markus 2213: auth_request_forwarding()
1.1 deraadt 2214: {
1.25 markus 2215: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2216: packet_send();
2217: packet_write_wait();
1.1 deraadt 2218: }
2219:
1.27 markus 2220: /*
2221: * Returns the name of the forwarded authentication socket. Returns NULL if
2222: * there is no forwarded authentication socket. The returned value points to
2223: * a static buffer.
2224: */
1.1 deraadt 2225:
1.25 markus 2226: char *
2227: auth_get_socket_name()
1.1 deraadt 2228: {
1.25 markus 2229: return channel_forwarded_auth_socket_name;
1.1 deraadt 2230: }
2231:
1.12 markus 2232: /* removes the agent forwarding socket */
2233:
1.49 markus 2234: void
1.25 markus 2235: cleanup_socket(void)
2236: {
1.78 markus 2237: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2238: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2239: }
2240:
1.27 markus 2241: /*
1.59 markus 2242: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2243: * This starts forwarding authentication requests.
2244: */
1.1 deraadt 2245:
1.59 markus 2246: int
1.25 markus 2247: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2248: {
1.25 markus 2249: int sock, newch;
2250: struct sockaddr_un sunaddr;
2251:
2252: if (auth_get_socket_name() != NULL)
2253: fatal("Protocol error: authentication forwarding requested twice.");
2254:
2255: /* Temporarily drop privileged uid for mkdir/bind. */
2256: temporarily_use_uid(pw->pw_uid);
2257:
2258: /* Allocate a buffer for the socket name, and format the name. */
2259: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2260: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2261: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2262:
2263: /* Create private directory for socket */
1.59 markus 2264: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2265: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2266: strerror(errno));
2267: restore_uid();
2268: xfree(channel_forwarded_auth_socket_name);
2269: xfree(channel_forwarded_auth_socket_dir);
2270: channel_forwarded_auth_socket_name = NULL;
2271: channel_forwarded_auth_socket_dir = NULL;
2272: return 0;
2273: }
1.25 markus 2274: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2275: channel_forwarded_auth_socket_dir, (int) getpid());
2276:
2277: if (atexit(cleanup_socket) < 0) {
2278: int saved = errno;
2279: cleanup_socket();
2280: packet_disconnect("socket: %.100s", strerror(saved));
2281: }
2282: /* Create the socket. */
2283: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2284: if (sock < 0)
2285: packet_disconnect("socket: %.100s", strerror(errno));
2286:
2287: /* Bind it to the name. */
2288: memset(&sunaddr, 0, sizeof(sunaddr));
2289: sunaddr.sun_family = AF_UNIX;
2290: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2291: sizeof(sunaddr.sun_path));
2292:
2293: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2294: packet_disconnect("bind: %.100s", strerror(errno));
2295:
2296: /* Restore the privileged uid. */
2297: restore_uid();
2298:
2299: /* Start listening on the socket. */
2300: if (listen(sock, 5) < 0)
2301: packet_disconnect("listen: %.100s", strerror(errno));
2302:
2303: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2304: newch = channel_new("auth socket",
2305: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2306: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2307: 0, xstrdup("auth socket"), 1);
2308:
1.32 deraadt 2309: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2310: sizeof(channels[newch].path));
1.59 markus 2311: return 1;
1.1 deraadt 2312: }
2313:
2314: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2315:
1.49 markus 2316: void
1.69 markus 2317: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2318: {
1.25 markus 2319: int remch, sock, newch;
2320: char *dummyname;
1.41 markus 2321:
2322: packet_integrity_check(plen, 4, type);
1.25 markus 2323:
2324: /* Read the remote channel number from the message. */
2325: remch = packet_get_int();
2326:
1.27 markus 2327: /*
2328: * Get a connection to the local authentication agent (this may again
2329: * get forwarded).
2330: */
1.25 markus 2331: sock = ssh_get_authentication_socket();
2332:
1.27 markus 2333: /*
2334: * If we could not connect the agent, send an error message back to
2335: * the server. This should never happen unless the agent dies,
2336: * because authentication forwarding is only enabled if we have an
2337: * agent.
2338: */
1.25 markus 2339: if (sock < 0) {
2340: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2341: packet_put_int(remch);
2342: packet_send();
2343: return;
2344: }
2345: debug("Forwarding authentication connection.");
1.1 deraadt 2346:
1.27 markus 2347: /*
2348: * Dummy host name. This will be freed when the channel is freed; it
2349: * will still be valid in the packet_put_string below since the
2350: * channel cannot yet be freed at that point.
2351: */
1.25 markus 2352: dummyname = xstrdup("authentication agent connection");
2353:
2354: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2355: channels[newch].remote_id = remch;
2356:
2357: /* Send a confirmation to the remote host. */
2358: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2359: packet_put_int(remch);
2360: packet_put_int(newch);
1.44 markus 2361: packet_send();
2362: }
2363:
2364: void
1.51 markus 2365: channel_start_open(int id)
1.44 markus 2366: {
2367: Channel *c = channel_lookup(id);
2368: if (c == NULL) {
2369: log("channel_open: %d: bad id", id);
2370: return;
2371: }
1.51 markus 2372: debug("send channel open %d", id);
1.44 markus 2373: packet_start(SSH2_MSG_CHANNEL_OPEN);
2374: packet_put_cstring(c->ctype);
2375: packet_put_int(c->self);
2376: packet_put_int(c->local_window);
2377: packet_put_int(c->local_maxpacket);
1.51 markus 2378: }
2379: void
2380: channel_open(int id)
2381: {
2382: /* XXX REMOVE ME */
2383: channel_start_open(id);
1.44 markus 2384: packet_send();
2385: }
2386: void
2387: channel_request(int id, char *service, int wantconfirm)
2388: {
2389: channel_request_start(id, service, wantconfirm);
2390: packet_send();
2391: debug("channel request %d: %s", id, service) ;
2392: }
2393: void
2394: channel_request_start(int id, char *service, int wantconfirm)
2395: {
2396: Channel *c = channel_lookup(id);
2397: if (c == NULL) {
2398: log("channel_request: %d: bad id", id);
2399: return;
2400: }
2401: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2402: packet_put_int(c->remote_id);
2403: packet_put_cstring(service);
2404: packet_put_char(wantconfirm);
2405: }
2406: void
2407: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2408: {
2409: Channel *c = channel_lookup(id);
2410: if (c == NULL) {
2411: log("channel_register_callback: %d: bad id", id);
2412: return;
2413: }
2414: c->cb_event = mtype;
2415: c->cb_fn = fn;
2416: c->cb_arg = arg;
2417: }
2418: void
2419: channel_register_cleanup(int id, channel_callback_fn *fn)
2420: {
2421: Channel *c = channel_lookup(id);
2422: if (c == NULL) {
2423: log("channel_register_cleanup: %d: bad id", id);
2424: return;
2425: }
2426: c->dettach_user = fn;
2427: }
2428: void
2429: channel_cancel_cleanup(int id)
2430: {
2431: Channel *c = channel_lookup(id);
2432: if (c == NULL) {
2433: log("channel_cancel_cleanup: %d: bad id", id);
2434: return;
2435: }
2436: c->dettach_user = NULL;
1.65 markus 2437: }
2438: void
2439: channel_register_filter(int id, channel_filter_fn *fn)
2440: {
2441: Channel *c = channel_lookup(id);
2442: if (c == NULL) {
2443: log("channel_register_filter: %d: bad id", id);
2444: return;
2445: }
2446: c->input_filter = fn;
1.44 markus 2447: }
2448:
2449: void
1.71 markus 2450: channel_set_fds(int id, int rfd, int wfd, int efd,
2451: int extusage, int nonblock)
1.44 markus 2452: {
2453: Channel *c = channel_lookup(id);
2454: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2455: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2456: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2457: c->type = SSH_CHANNEL_OPEN;
2458: /* XXX window size? */
1.68 markus 2459: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2460: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2461: packet_put_int(c->remote_id);
2462: packet_put_int(c->local_window);
1.25 markus 2463: packet_send();
1.1 deraadt 2464: }
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