Annotation of src/usr.bin/ssh/channels.c, Revision 1.231
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: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.156 markus 16: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.231 ! reyk 42: RCSID("$OpenBSD: channels.c,v 1.230 2005/12/28 22:46:06 stevesk Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.h"
1.193 markus 57: #include "bufaux.h"
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.209 avsm 71: static u_int channels_alloc = 0;
1.1 deraadt 72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
1.219 djm 112: /* Saved X11 local (client) display. */
113: static char *x11_saved_display = NULL;
114:
1.121 markus 115: /* Saved X11 authentication protocol name. */
116: static char *x11_saved_proto = NULL;
117:
118: /* Saved X11 authentication data. This is the real data. */
119: static char *x11_saved_data = NULL;
120: static u_int x11_saved_data_len = 0;
121:
122: /*
123: * Fake X11 authentication data. This is what the server will be sending us;
124: * we should replace any occurrences of this by the real data.
125: */
126: static char *x11_fake_data = NULL;
127: static u_int x11_fake_data_len;
128:
129:
130: /* -- agent forwarding */
131:
132: #define NUM_SOCKS 10
133:
1.82 markus 134: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 135: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 136:
1.121 markus 137: /* helper */
1.127 itojun 138: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 139:
1.121 markus 140: /* -- channel core */
1.41 markus 141:
142: Channel *
1.229 markus 143: channel_by_id(int id)
1.41 markus 144: {
145: Channel *c;
1.113 markus 146:
1.209 avsm 147: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 148: logit("channel_by_id: %d: bad id", id);
1.41 markus 149: return NULL;
150: }
1.113 markus 151: c = channels[id];
152: if (c == NULL) {
1.229 markus 153: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 154: return NULL;
155: }
156: return c;
1.55 markus 157: }
158:
1.27 markus 159: /*
1.229 markus 160: * Returns the channel if it is allowed to receive protocol messages.
161: * Private channels, like listening sockets, may not receive messages.
162: */
163: Channel *
164: channel_lookup(int id)
165: {
166: Channel *c;
167:
168: if ((c = channel_by_id(id)) == NULL)
169: return (NULL);
170:
171: switch(c->type) {
172: case SSH_CHANNEL_X11_OPEN:
173: case SSH_CHANNEL_LARVAL:
174: case SSH_CHANNEL_CONNECTING:
175: case SSH_CHANNEL_DYNAMIC:
176: case SSH_CHANNEL_OPENING:
177: case SSH_CHANNEL_OPEN:
178: case SSH_CHANNEL_INPUT_DRAINING:
179: case SSH_CHANNEL_OUTPUT_DRAINING:
180: return (c);
181: break;
182: }
183: logit("Non-public channel %d, type %d.", id, c->type);
184: return (NULL);
185: }
186:
187: /*
1.55 markus 188: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 189: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 190: */
1.1 deraadt 191:
1.127 itojun 192: static void
1.71 markus 193: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
194: int extusage, int nonblock)
1.1 deraadt 195: {
1.25 markus 196: /* Update the maximum file descriptor value. */
1.84 markus 197: channel_max_fd = MAX(channel_max_fd, rfd);
198: channel_max_fd = MAX(channel_max_fd, wfd);
199: channel_max_fd = MAX(channel_max_fd, efd);
200:
1.27 markus 201: /* XXX set close-on-exec -markus */
1.55 markus 202:
1.52 markus 203: c->rfd = rfd;
204: c->wfd = wfd;
205: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 206: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 207: c->efd = efd;
208: c->extended_usage = extusage;
1.71 markus 209:
1.91 markus 210: /* XXX ugly hack: nonblock is only set by the server */
211: if (nonblock && isatty(c->rfd)) {
1.194 markus 212: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 213: c->isatty = 1;
214: if (!isatty(c->wfd)) {
1.94 markus 215: error("channel %d: wfd %d is not a tty?",
1.91 markus 216: c->self, c->wfd);
217: }
218: } else {
219: c->isatty = 0;
220: }
221:
1.71 markus 222: /* enable nonblocking mode */
223: if (nonblock) {
224: if (rfd != -1)
225: set_nonblock(rfd);
226: if (wfd != -1)
227: set_nonblock(wfd);
228: if (efd != -1)
229: set_nonblock(efd);
230: }
1.52 markus 231: }
232:
233: /*
234: * Allocate a new channel object and set its type and socket. This will cause
235: * remote_name to be freed.
236: */
237:
1.113 markus 238: Channel *
1.52 markus 239: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 240: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 241: {
1.209 avsm 242: int found;
243: u_int i;
1.52 markus 244: Channel *c;
1.25 markus 245:
246: /* Do initial allocation if this is the first call. */
247: if (channels_alloc == 0) {
248: channels_alloc = 10;
1.113 markus 249: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 250: for (i = 0; i < channels_alloc; i++)
1.113 markus 251: channels[i] = NULL;
1.25 markus 252: }
253: /* Try to find a free slot where to put the new channel. */
254: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 255: if (channels[i] == NULL) {
1.25 markus 256: /* Found a free slot. */
1.209 avsm 257: found = (int)i;
1.25 markus 258: break;
259: }
1.209 avsm 260: if (found < 0) {
1.27 markus 261: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 262: found = channels_alloc;
1.179 markus 263: if (channels_alloc > 10000)
264: fatal("channel_new: internal error: channels_alloc %d "
265: "too big.", channels_alloc);
1.195 markus 266: channels = xrealloc(channels,
267: (channels_alloc + 10) * sizeof(Channel *));
268: channels_alloc += 10;
1.70 markus 269: debug2("channel: expanding %d", channels_alloc);
1.25 markus 270: for (i = found; i < channels_alloc; i++)
1.113 markus 271: channels[i] = NULL;
1.25 markus 272: }
1.113 markus 273: /* Initialize and return new channel. */
274: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 275: memset(c, 0, sizeof(Channel));
1.25 markus 276: buffer_init(&c->input);
277: buffer_init(&c->output);
1.41 markus 278: buffer_init(&c->extended);
1.159 markus 279: c->ostate = CHAN_OUTPUT_OPEN;
280: c->istate = CHAN_INPUT_OPEN;
281: c->flags = 0;
1.71 markus 282: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 283: c->self = found;
284: c->type = type;
1.41 markus 285: c->ctype = ctype;
1.51 markus 286: c->local_window = window;
287: c->local_window_max = window;
288: c->local_consumed = 0;
289: c->local_maxpacket = maxpack;
1.25 markus 290: c->remote_id = -1;
1.190 markus 291: c->remote_name = xstrdup(remote_name);
1.41 markus 292: c->remote_window = 0;
293: c->remote_maxpacket = 0;
1.133 markus 294: c->force_drain = 0;
1.149 markus 295: c->single_connection = 0;
1.131 markus 296: c->detach_user = NULL;
1.225 djm 297: c->detach_close = 0;
1.165 markus 298: c->confirm = NULL;
1.204 djm 299: c->confirm_ctx = NULL;
1.65 markus 300: c->input_filter = NULL;
1.231 ! reyk 301: c->output_filter = NULL;
1.25 markus 302: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 303: return c;
1.1 deraadt 304: }
1.52 markus 305:
1.132 markus 306: static int
307: channel_find_maxfd(void)
308: {
1.209 avsm 309: u_int i;
310: int max = 0;
1.132 markus 311: Channel *c;
312:
313: for (i = 0; i < channels_alloc; i++) {
314: c = channels[i];
315: if (c != NULL) {
316: max = MAX(max, c->rfd);
317: max = MAX(max, c->wfd);
318: max = MAX(max, c->efd);
319: }
320: }
321: return max;
322: }
323:
324: int
325: channel_close_fd(int *fdp)
326: {
327: int ret = 0, fd = *fdp;
328:
329: if (fd != -1) {
330: ret = close(fd);
331: *fdp = -1;
332: if (fd == channel_max_fd)
333: channel_max_fd = channel_find_maxfd();
334: }
335: return ret;
336: }
337:
1.52 markus 338: /* Close all channel fd/socket. */
339:
1.127 itojun 340: static void
1.52 markus 341: channel_close_fds(Channel *c)
342: {
1.204 djm 343: debug3("channel %d: close_fds r %d w %d e %d c %d",
344: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 345:
1.132 markus 346: channel_close_fd(&c->sock);
1.204 djm 347: channel_close_fd(&c->ctl_fd);
1.132 markus 348: channel_close_fd(&c->rfd);
349: channel_close_fd(&c->wfd);
350: channel_close_fd(&c->efd);
1.121 markus 351: }
352:
353: /* Free the channel and close its fd/socket. */
354:
355: void
356: channel_free(Channel *c)
357: {
358: char *s;
1.209 avsm 359: u_int i, n;
1.121 markus 360:
361: for (n = 0, i = 0; i < channels_alloc; i++)
362: if (channels[i])
363: n++;
1.209 avsm 364: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 365: c->remote_name ? c->remote_name : "???", n);
366:
367: s = channel_open_message();
1.194 markus 368: debug3("channel %d: status: %s", c->self, s);
1.121 markus 369: xfree(s);
370:
371: if (c->sock != -1)
372: shutdown(c->sock, SHUT_RDWR);
1.204 djm 373: if (c->ctl_fd != -1)
374: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 375: channel_close_fds(c);
376: buffer_free(&c->input);
377: buffer_free(&c->output);
378: buffer_free(&c->extended);
379: if (c->remote_name) {
380: xfree(c->remote_name);
381: c->remote_name = NULL;
382: }
383: channels[c->self] = NULL;
384: xfree(c);
385: }
386:
387: void
1.126 markus 388: channel_free_all(void)
1.121 markus 389: {
1.209 avsm 390: u_int i;
1.121 markus 391:
1.126 markus 392: for (i = 0; i < channels_alloc; i++)
393: if (channels[i] != NULL)
394: channel_free(channels[i]);
1.131 markus 395: }
396:
1.121 markus 397: /*
398: * Closes the sockets/fds of all channels. This is used to close extra file
399: * descriptors after a fork.
400: */
401:
402: void
1.142 itojun 403: channel_close_all(void)
1.121 markus 404: {
1.209 avsm 405: u_int i;
1.121 markus 406:
407: for (i = 0; i < channels_alloc; i++)
408: if (channels[i] != NULL)
409: channel_close_fds(channels[i]);
410: }
411:
412: /*
1.131 markus 413: * Stop listening to channels.
414: */
415:
416: void
417: channel_stop_listening(void)
418: {
1.209 avsm 419: u_int i;
1.131 markus 420: Channel *c;
421:
422: for (i = 0; i < channels_alloc; i++) {
423: c = channels[i];
424: if (c != NULL) {
425: switch (c->type) {
426: case SSH_CHANNEL_AUTH_SOCKET:
427: case SSH_CHANNEL_PORT_LISTENER:
428: case SSH_CHANNEL_RPORT_LISTENER:
429: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 430: channel_close_fd(&c->sock);
1.131 markus 431: channel_free(c);
432: break;
433: }
434: }
435: }
436: }
437:
438: /*
1.121 markus 439: * Returns true if no channel has too much buffered data, and false if one or
440: * more channel is overfull.
441: */
442:
443: int
1.142 itojun 444: channel_not_very_much_buffered_data(void)
1.121 markus 445: {
446: u_int i;
447: Channel *c;
448:
449: for (i = 0; i < channels_alloc; i++) {
450: c = channels[i];
451: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 452: #if 0
453: if (!compat20 &&
454: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 455: debug2("channel %d: big input buffer %d",
1.121 markus 456: c->self, buffer_len(&c->input));
457: return 0;
458: }
1.136 markus 459: #endif
1.121 markus 460: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 461: debug2("channel %d: big output buffer %u > %u",
1.136 markus 462: c->self, buffer_len(&c->output),
463: packet_get_maxsize());
1.121 markus 464: return 0;
465: }
466: }
467: }
468: return 1;
469: }
470:
471: /* Returns true if any channel is still open. */
472:
473: int
1.142 itojun 474: channel_still_open(void)
1.121 markus 475: {
1.209 avsm 476: u_int i;
1.121 markus 477: Channel *c;
478:
479: for (i = 0; i < channels_alloc; i++) {
480: c = channels[i];
481: if (c == NULL)
482: continue;
483: switch (c->type) {
484: case SSH_CHANNEL_X11_LISTENER:
485: case SSH_CHANNEL_PORT_LISTENER:
486: case SSH_CHANNEL_RPORT_LISTENER:
487: case SSH_CHANNEL_CLOSED:
488: case SSH_CHANNEL_AUTH_SOCKET:
489: case SSH_CHANNEL_DYNAMIC:
490: case SSH_CHANNEL_CONNECTING:
491: case SSH_CHANNEL_ZOMBIE:
492: continue;
493: case SSH_CHANNEL_LARVAL:
494: if (!compat20)
495: fatal("cannot happen: SSH_CHANNEL_LARVAL");
496: continue;
497: case SSH_CHANNEL_OPENING:
498: case SSH_CHANNEL_OPEN:
499: case SSH_CHANNEL_X11_OPEN:
500: return 1;
501: case SSH_CHANNEL_INPUT_DRAINING:
502: case SSH_CHANNEL_OUTPUT_DRAINING:
503: if (!compat13)
504: fatal("cannot happen: OUT_DRAIN");
505: return 1;
506: default:
507: fatal("channel_still_open: bad channel type %d", c->type);
508: /* NOTREACHED */
509: }
510: }
511: return 0;
512: }
513:
514: /* Returns the id of an open channel suitable for keepaliving */
515:
516: int
1.142 itojun 517: channel_find_open(void)
1.121 markus 518: {
1.209 avsm 519: u_int i;
1.121 markus 520: Channel *c;
521:
522: for (i = 0; i < channels_alloc; i++) {
523: c = channels[i];
1.206 djm 524: if (c == NULL || c->remote_id < 0)
1.121 markus 525: continue;
526: switch (c->type) {
527: case SSH_CHANNEL_CLOSED:
528: case SSH_CHANNEL_DYNAMIC:
529: case SSH_CHANNEL_X11_LISTENER:
530: case SSH_CHANNEL_PORT_LISTENER:
531: case SSH_CHANNEL_RPORT_LISTENER:
532: case SSH_CHANNEL_OPENING:
533: case SSH_CHANNEL_CONNECTING:
534: case SSH_CHANNEL_ZOMBIE:
535: continue;
536: case SSH_CHANNEL_LARVAL:
537: case SSH_CHANNEL_AUTH_SOCKET:
538: case SSH_CHANNEL_OPEN:
539: case SSH_CHANNEL_X11_OPEN:
540: return i;
541: case SSH_CHANNEL_INPUT_DRAINING:
542: case SSH_CHANNEL_OUTPUT_DRAINING:
543: if (!compat13)
544: fatal("cannot happen: OUT_DRAIN");
545: return i;
546: default:
547: fatal("channel_find_open: bad channel type %d", c->type);
548: /* NOTREACHED */
549: }
550: }
551: return -1;
552: }
553:
554:
555: /*
556: * Returns a message describing the currently open forwarded connections,
557: * suitable for sending to the client. The message contains crlf pairs for
558: * newlines.
559: */
560:
561: char *
1.142 itojun 562: channel_open_message(void)
1.121 markus 563: {
564: Buffer buffer;
565: Channel *c;
566: char buf[1024], *cp;
1.209 avsm 567: u_int i;
1.121 markus 568:
569: buffer_init(&buffer);
570: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
571: buffer_append(&buffer, buf, strlen(buf));
572: for (i = 0; i < channels_alloc; i++) {
573: c = channels[i];
574: if (c == NULL)
575: continue;
576: switch (c->type) {
577: case SSH_CHANNEL_X11_LISTENER:
578: case SSH_CHANNEL_PORT_LISTENER:
579: case SSH_CHANNEL_RPORT_LISTENER:
580: case SSH_CHANNEL_CLOSED:
581: case SSH_CHANNEL_AUTH_SOCKET:
582: case SSH_CHANNEL_ZOMBIE:
583: continue;
584: case SSH_CHANNEL_LARVAL:
585: case SSH_CHANNEL_OPENING:
586: case SSH_CHANNEL_CONNECTING:
587: case SSH_CHANNEL_DYNAMIC:
588: case SSH_CHANNEL_OPEN:
589: case SSH_CHANNEL_X11_OPEN:
590: case SSH_CHANNEL_INPUT_DRAINING:
591: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 592: snprintf(buf, sizeof buf,
593: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 594: c->self, c->remote_name,
595: c->type, c->remote_id,
596: c->istate, buffer_len(&c->input),
597: c->ostate, buffer_len(&c->output),
1.204 djm 598: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 599: buffer_append(&buffer, buf, strlen(buf));
600: continue;
601: default:
602: fatal("channel_open_message: bad channel type %d", c->type);
603: /* NOTREACHED */
604: }
605: }
606: buffer_append(&buffer, "\0", 1);
607: cp = xstrdup(buffer_ptr(&buffer));
608: buffer_free(&buffer);
609: return cp;
610: }
611:
612: void
613: channel_send_open(int id)
614: {
615: Channel *c = channel_lookup(id);
1.180 deraadt 616:
1.121 markus 617: if (c == NULL) {
1.188 itojun 618: logit("channel_send_open: %d: bad id", id);
1.121 markus 619: return;
620: }
1.184 markus 621: debug2("channel %d: send open", id);
1.121 markus 622: packet_start(SSH2_MSG_CHANNEL_OPEN);
623: packet_put_cstring(c->ctype);
624: packet_put_int(c->self);
625: packet_put_int(c->local_window);
626: packet_put_int(c->local_maxpacket);
627: packet_send();
628: }
629:
630: void
1.184 markus 631: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 632: {
1.184 markus 633: Channel *c = channel_lookup(id);
1.180 deraadt 634:
1.121 markus 635: if (c == NULL) {
1.188 itojun 636: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 637: return;
638: }
1.204 djm 639: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 640: packet_start(SSH2_MSG_CHANNEL_REQUEST);
641: packet_put_int(c->remote_id);
642: packet_put_cstring(service);
643: packet_put_char(wantconfirm);
644: }
645: void
1.204 djm 646: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 647: {
648: Channel *c = channel_lookup(id);
1.180 deraadt 649:
1.121 markus 650: if (c == NULL) {
1.188 itojun 651: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 652: return;
653: }
1.165 markus 654: c->confirm = fn;
1.204 djm 655: c->confirm_ctx = ctx;
1.121 markus 656: }
657: void
1.225 djm 658: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 659: {
1.229 markus 660: Channel *c = channel_by_id(id);
1.180 deraadt 661:
1.121 markus 662: if (c == NULL) {
1.188 itojun 663: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 664: return;
665: }
1.131 markus 666: c->detach_user = fn;
1.225 djm 667: c->detach_close = do_close;
1.121 markus 668: }
669: void
670: channel_cancel_cleanup(int id)
671: {
1.229 markus 672: Channel *c = channel_by_id(id);
1.180 deraadt 673:
1.121 markus 674: if (c == NULL) {
1.188 itojun 675: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 676: return;
1.52 markus 677: }
1.131 markus 678: c->detach_user = NULL;
1.225 djm 679: c->detach_close = 0;
1.121 markus 680: }
681: void
1.231 ! reyk 682: channel_register_filter(int id, channel_infilter_fn *ifn,
! 683: channel_outfilter_fn *ofn)
1.121 markus 684: {
685: Channel *c = channel_lookup(id);
1.180 deraadt 686:
1.121 markus 687: if (c == NULL) {
1.188 itojun 688: logit("channel_register_filter: %d: bad id", id);
1.121 markus 689: return;
1.52 markus 690: }
1.231 ! reyk 691: c->input_filter = ifn;
! 692: c->output_filter = ofn;
1.52 markus 693: }
694:
1.49 markus 695: void
1.121 markus 696: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 697: int extusage, int nonblock, u_int window_max)
1.1 deraadt 698: {
1.121 markus 699: Channel *c = channel_lookup(id);
1.180 deraadt 700:
1.121 markus 701: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
702: fatal("channel_activate for non-larval channel %d.", id);
703: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
704: c->type = SSH_CHANNEL_OPEN;
1.168 markus 705: c->local_window = c->local_window_max = window_max;
1.121 markus 706: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
707: packet_put_int(c->remote_id);
708: packet_put_int(c->local_window);
709: packet_send();
1.1 deraadt 710: }
711:
1.27 markus 712: /*
1.41 markus 713: * 'channel_pre*' are called just before select() to add any bits relevant to
714: * channels in the select bitmasks.
715: */
716: /*
717: * 'channel_post*': perform any appropriate operations for channels which
718: * have events pending.
1.27 markus 719: */
1.41 markus 720: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
721: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
722: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
723:
1.127 itojun 724: static void
1.41 markus 725: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
726: {
727: FD_SET(c->sock, readset);
728: }
729:
1.127 itojun 730: static void
1.75 markus 731: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
732: {
733: debug3("channel %d: waiting for connection", c->self);
734: FD_SET(c->sock, writeset);
735: }
736:
1.127 itojun 737: static void
1.41 markus 738: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
739: {
740: if (buffer_len(&c->input) < packet_get_maxsize())
741: FD_SET(c->sock, readset);
742: if (buffer_len(&c->output) > 0)
743: FD_SET(c->sock, writeset);
744: }
1.1 deraadt 745:
1.127 itojun 746: static void
1.157 markus 747: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 748: {
1.157 markus 749: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 750:
1.214 markus 751: /* check buffer limits */
752: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
753:
1.44 markus 754: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 755: limit > 0 &&
756: buffer_len(&c->input) < limit)
1.44 markus 757: FD_SET(c->rfd, readset);
758: if (c->ostate == CHAN_OUTPUT_OPEN ||
759: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
760: if (buffer_len(&c->output) > 0) {
761: FD_SET(c->wfd, writeset);
762: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 763: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 764: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
765: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 766: else
767: chan_obuf_empty(c);
1.44 markus 768: }
769: }
770: /** XXX check close conditions, too */
1.157 markus 771: if (compat20 && c->efd != -1) {
1.44 markus 772: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
773: buffer_len(&c->extended) > 0)
774: FD_SET(c->efd, writeset);
1.172 markus 775: else if (!(c->flags & CHAN_EOF_SENT) &&
776: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 777: buffer_len(&c->extended) < c->remote_window)
778: FD_SET(c->efd, readset);
779: }
1.204 djm 780: /* XXX: What about efd? races? */
1.208 deraadt 781: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 782: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
783: FD_SET(c->ctl_fd, readset);
1.44 markus 784: }
785:
1.127 itojun 786: static void
1.41 markus 787: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
788: {
789: if (buffer_len(&c->input) == 0) {
790: packet_start(SSH_MSG_CHANNEL_CLOSE);
791: packet_put_int(c->remote_id);
792: packet_send();
793: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 794: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 795: }
796: }
797:
1.127 itojun 798: static void
1.41 markus 799: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
800: {
801: if (buffer_len(&c->output) == 0)
1.113 markus 802: chan_mark_dead(c);
1.49 markus 803: else
1.41 markus 804: FD_SET(c->sock, writeset);
805: }
806:
807: /*
808: * This is a special state for X11 authentication spoofing. An opened X11
809: * connection (when authentication spoofing is being done) remains in this
810: * state until the first packet has been completely read. The authentication
811: * data in that packet is then substituted by the real data if it matches the
812: * fake data, and the channel is put into normal mode.
1.51 markus 813: * XXX All this happens at the client side.
1.121 markus 814: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 815: */
1.127 itojun 816: static int
1.121 markus 817: x11_open_helper(Buffer *b)
1.1 deraadt 818: {
1.77 markus 819: u_char *ucp;
820: u_int proto_len, data_len;
1.25 markus 821:
1.41 markus 822: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 823: if (buffer_len(b) < 12)
1.41 markus 824: return 0;
825:
826: /* Parse the lengths of variable-length fields. */
1.155 stevesk 827: ucp = buffer_ptr(b);
1.41 markus 828: if (ucp[0] == 0x42) { /* Byte order MSB first. */
829: proto_len = 256 * ucp[6] + ucp[7];
830: data_len = 256 * ucp[8] + ucp[9];
831: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
832: proto_len = ucp[6] + 256 * ucp[7];
833: data_len = ucp[8] + 256 * ucp[9];
834: } else {
1.194 markus 835: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 836: ucp[0]);
1.41 markus 837: return -1;
838: }
839:
840: /* Check if the whole packet is in buffer. */
1.121 markus 841: if (buffer_len(b) <
1.41 markus 842: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
843: return 0;
844:
845: /* Check if authentication protocol matches. */
846: if (proto_len != strlen(x11_saved_proto) ||
847: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 848: debug2("X11 connection uses different authentication protocol.");
1.41 markus 849: return -1;
850: }
851: /* Check if authentication data matches our fake data. */
852: if (data_len != x11_fake_data_len ||
853: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
854: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 855: debug2("X11 auth data does not match fake data.");
1.41 markus 856: return -1;
857: }
858: /* Check fake data length */
859: if (x11_fake_data_len != x11_saved_data_len) {
860: error("X11 fake_data_len %d != saved_data_len %d",
861: x11_fake_data_len, x11_saved_data_len);
862: return -1;
863: }
864: /*
865: * Received authentication protocol and data match
866: * our fake data. Substitute the fake data with real
867: * data.
868: */
869: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
870: x11_saved_data, x11_saved_data_len);
871: return 1;
872: }
873:
1.127 itojun 874: static void
1.41 markus 875: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
876: {
1.121 markus 877: int ret = x11_open_helper(&c->output);
1.180 deraadt 878:
1.41 markus 879: if (ret == 1) {
880: /* Start normal processing for the channel. */
881: c->type = SSH_CHANNEL_OPEN;
1.47 markus 882: channel_pre_open_13(c, readset, writeset);
1.41 markus 883: } else if (ret == -1) {
884: /*
885: * We have received an X11 connection that has bad
886: * authentication information.
887: */
1.188 itojun 888: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 889: buffer_clear(&c->input);
890: buffer_clear(&c->output);
1.132 markus 891: channel_close_fd(&c->sock);
1.41 markus 892: c->sock = -1;
893: c->type = SSH_CHANNEL_CLOSED;
894: packet_start(SSH_MSG_CHANNEL_CLOSE);
895: packet_put_int(c->remote_id);
896: packet_send();
897: }
898: }
1.25 markus 899:
1.127 itojun 900: static void
1.51 markus 901: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 902: {
1.121 markus 903: int ret = x11_open_helper(&c->output);
1.133 markus 904:
905: /* c->force_drain = 1; */
906:
1.41 markus 907: if (ret == 1) {
908: c->type = SSH_CHANNEL_OPEN;
1.157 markus 909: channel_pre_open(c, readset, writeset);
1.41 markus 910: } else if (ret == -1) {
1.188 itojun 911: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 912: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 913: chan_read_failed(c);
914: buffer_clear(&c->input);
915: chan_ibuf_empty(c);
916: buffer_clear(&c->output);
917: /* for proto v1, the peer will send an IEOF */
918: if (compat20)
919: chan_write_failed(c);
920: else
921: c->type = SSH_CHANNEL_OPEN;
1.194 markus 922: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 923: }
924: }
1.25 markus 925:
1.104 markus 926: /* try to decode a socks4 header */
1.127 itojun 927: static int
1.104 markus 928: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 929: {
1.181 markus 930: char *p, *host;
1.217 djm 931: u_int len, have, i, found;
1.148 deraadt 932: char username[256];
1.103 markus 933: struct {
934: u_int8_t version;
935: u_int8_t command;
936: u_int16_t dest_port;
1.104 markus 937: struct in_addr dest_addr;
1.103 markus 938: } s4_req, s4_rsp;
939:
1.104 markus 940: debug2("channel %d: decode socks4", c->self);
1.109 markus 941:
942: have = buffer_len(&c->input);
943: len = sizeof(s4_req);
944: if (have < len)
945: return 0;
946: p = buffer_ptr(&c->input);
947: for (found = 0, i = len; i < have; i++) {
948: if (p[i] == '\0') {
949: found = 1;
950: break;
951: }
952: if (i > 1024) {
953: /* the peer is probably sending garbage */
954: debug("channel %d: decode socks4: too long",
955: c->self);
956: return -1;
957: }
958: }
959: if (!found)
960: return 0;
1.103 markus 961: buffer_get(&c->input, (char *)&s4_req.version, 1);
962: buffer_get(&c->input, (char *)&s4_req.command, 1);
963: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 964: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 965: have = buffer_len(&c->input);
1.103 markus 966: p = buffer_ptr(&c->input);
967: len = strlen(p);
1.106 markus 968: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 969: if (len > have)
1.104 markus 970: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 971: c->self, len, have);
972: strlcpy(username, p, sizeof(username));
973: buffer_consume(&c->input, len);
974: buffer_consume(&c->input, 1); /* trailing '\0' */
975:
1.104 markus 976: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 977: strlcpy(c->path, host, sizeof(c->path));
978: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 979:
1.194 markus 980: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 981: c->self, host, c->host_port, s4_req.command);
1.103 markus 982:
1.104 markus 983: if (s4_req.command != 1) {
984: debug("channel %d: cannot handle: socks4 cn %d",
985: c->self, s4_req.command);
986: return -1;
1.103 markus 987: }
1.104 markus 988: s4_rsp.version = 0; /* vn: 0 for reply */
989: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 990: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 991: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 992: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 993: return 1;
994: }
995:
1.193 markus 996: /* try to decode a socks5 header */
997: #define SSH_SOCKS5_AUTHDONE 0x1000
998: #define SSH_SOCKS5_NOAUTH 0x00
999: #define SSH_SOCKS5_IPV4 0x01
1000: #define SSH_SOCKS5_DOMAIN 0x03
1001: #define SSH_SOCKS5_IPV6 0x04
1002: #define SSH_SOCKS5_CONNECT 0x01
1003: #define SSH_SOCKS5_SUCCESS 0x00
1004:
1005: static int
1006: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
1007: {
1008: struct {
1009: u_int8_t version;
1010: u_int8_t command;
1011: u_int8_t reserved;
1012: u_int8_t atyp;
1013: } s5_req, s5_rsp;
1014: u_int16_t dest_port;
1015: u_char *p, dest_addr[255+1];
1.217 djm 1016: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 1017:
1018: debug2("channel %d: decode socks5", c->self);
1019: p = buffer_ptr(&c->input);
1020: if (p[0] != 0x05)
1021: return -1;
1022: have = buffer_len(&c->input);
1023: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1024: /* format: ver | nmethods | methods */
1.198 djm 1025: if (have < 2)
1.193 markus 1026: return 0;
1027: nmethods = p[1];
1028: if (have < nmethods + 2)
1029: return 0;
1030: /* look for method: "NO AUTHENTICATION REQUIRED" */
1031: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1032: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1033: found = 1;
1034: break;
1035: }
1036: }
1037: if (!found) {
1038: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1039: c->self);
1040: return -1;
1041: }
1042: buffer_consume(&c->input, nmethods + 2);
1043: buffer_put_char(&c->output, 0x05); /* version */
1044: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1045: FD_SET(c->sock, writeset);
1046: c->flags |= SSH_SOCKS5_AUTHDONE;
1047: debug2("channel %d: socks5 auth done", c->self);
1048: return 0; /* need more */
1049: }
1050: debug2("channel %d: socks5 post auth", c->self);
1051: if (have < sizeof(s5_req)+1)
1052: return 0; /* need more */
1053: memcpy((char *)&s5_req, p, sizeof(s5_req));
1054: if (s5_req.version != 0x05 ||
1055: s5_req.command != SSH_SOCKS5_CONNECT ||
1056: s5_req.reserved != 0x00) {
1.194 markus 1057: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1058: return -1;
1059: }
1.213 deraadt 1060: switch (s5_req.atyp){
1.193 markus 1061: case SSH_SOCKS5_IPV4:
1062: addrlen = 4;
1063: af = AF_INET;
1064: break;
1065: case SSH_SOCKS5_DOMAIN:
1066: addrlen = p[sizeof(s5_req)];
1067: af = -1;
1068: break;
1069: case SSH_SOCKS5_IPV6:
1070: addrlen = 16;
1071: af = AF_INET6;
1072: break;
1073: default:
1.194 markus 1074: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1075: return -1;
1076: }
1077: if (have < 4 + addrlen + 2)
1078: return 0;
1079: buffer_consume(&c->input, sizeof(s5_req));
1080: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1081: buffer_consume(&c->input, 1); /* host string length */
1082: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1083: buffer_get(&c->input, (char *)&dest_port, 2);
1084: dest_addr[addrlen] = '\0';
1085: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1086: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1087: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1088: return -1;
1089: c->host_port = ntohs(dest_port);
1.198 djm 1090:
1.194 markus 1091: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1092: c->self, c->path, c->host_port, s5_req.command);
1093:
1094: s5_rsp.version = 0x05;
1095: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1096: s5_rsp.reserved = 0; /* ignored */
1097: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1098: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1099: dest_port = 0; /* ignored */
1100:
1101: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1102: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1103: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1104: return 1;
1105: }
1106:
1.104 markus 1107: /* dynamic port forwarding */
1.127 itojun 1108: static void
1.104 markus 1109: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1110: {
1111: u_char *p;
1.217 djm 1112: u_int have;
1113: int ret;
1.103 markus 1114:
1.104 markus 1115: have = buffer_len(&c->input);
1.137 markus 1116: c->delayed = 0;
1.104 markus 1117: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1118: /* buffer_dump(&c->input); */
1.104 markus 1119: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1120: if (have < 3) {
1.104 markus 1121: /* need more */
1122: FD_SET(c->sock, readset);
1123: return;
1124: }
1125: /* try to guess the protocol */
1126: p = buffer_ptr(&c->input);
1127: switch (p[0]) {
1128: case 0x04:
1129: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1130: break;
1131: case 0x05:
1132: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1133: break;
1134: default:
1135: ret = -1;
1136: break;
1137: }
1138: if (ret < 0) {
1.113 markus 1139: chan_mark_dead(c);
1.104 markus 1140: } else if (ret == 0) {
1141: debug2("channel %d: pre_dynamic: need more", c->self);
1142: /* need more */
1143: FD_SET(c->sock, readset);
1144: } else {
1145: /* switch to the next state */
1146: c->type = SSH_CHANNEL_OPENING;
1147: port_open_helper(c, "direct-tcpip");
1148: }
1.103 markus 1149: }
1150:
1.41 markus 1151: /* This is our fake X11 server socket. */
1.127 itojun 1152: static void
1.41 markus 1153: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1154: {
1.113 markus 1155: Channel *nc;
1.41 markus 1156: struct sockaddr addr;
1.162 stevesk 1157: int newsock;
1.41 markus 1158: socklen_t addrlen;
1.85 markus 1159: char buf[16384], *remote_ipaddr;
1.51 markus 1160: int remote_port;
1.25 markus 1161:
1.41 markus 1162: if (FD_ISSET(c->sock, readset)) {
1163: debug("X11 connection requested.");
1164: addrlen = sizeof(addr);
1165: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1166: if (c->single_connection) {
1.194 markus 1167: debug2("single_connection: closing X11 listener.");
1.149 markus 1168: channel_close_fd(&c->sock);
1169: chan_mark_dead(c);
1170: }
1.41 markus 1171: if (newsock < 0) {
1172: error("accept: %.100s", strerror(errno));
1173: return;
1174: }
1.162 stevesk 1175: set_nodelay(newsock);
1.85 markus 1176: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1177: remote_port = get_peer_port(newsock);
1.41 markus 1178: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1179: remote_ipaddr, remote_port);
1.51 markus 1180:
1.113 markus 1181: nc = channel_new("accepted x11 socket",
1.51 markus 1182: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1183: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1184: if (compat20) {
1185: packet_start(SSH2_MSG_CHANNEL_OPEN);
1186: packet_put_cstring("x11");
1.113 markus 1187: packet_put_int(nc->self);
1.149 markus 1188: packet_put_int(nc->local_window_max);
1189: packet_put_int(nc->local_maxpacket);
1.85 markus 1190: /* originator ipaddr and port */
1191: packet_put_cstring(remote_ipaddr);
1.57 markus 1192: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1193: debug2("ssh2 x11 bug compat mode");
1.57 markus 1194: } else {
1195: packet_put_int(remote_port);
1196: }
1.51 markus 1197: packet_send();
1198: } else {
1199: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1200: packet_put_int(nc->self);
1.121 markus 1201: if (packet_get_protocol_flags() &
1202: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1203: packet_put_cstring(buf);
1.51 markus 1204: packet_send();
1205: }
1.85 markus 1206: xfree(remote_ipaddr);
1.41 markus 1207: }
1208: }
1.25 markus 1209:
1.127 itojun 1210: static void
1.103 markus 1211: port_open_helper(Channel *c, char *rtype)
1212: {
1213: int direct;
1214: char buf[1024];
1215: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1216: int remote_port = get_peer_port(c->sock);
1.103 markus 1217:
1218: direct = (strcmp(rtype, "direct-tcpip") == 0);
1219:
1220: snprintf(buf, sizeof buf,
1221: "%s: listening port %d for %.100s port %d, "
1222: "connect from %.200s port %d",
1223: rtype, c->listening_port, c->path, c->host_port,
1224: remote_ipaddr, remote_port);
1225:
1226: xfree(c->remote_name);
1227: c->remote_name = xstrdup(buf);
1228:
1229: if (compat20) {
1230: packet_start(SSH2_MSG_CHANNEL_OPEN);
1231: packet_put_cstring(rtype);
1232: packet_put_int(c->self);
1233: packet_put_int(c->local_window_max);
1234: packet_put_int(c->local_maxpacket);
1235: if (direct) {
1236: /* target host, port */
1237: packet_put_cstring(c->path);
1238: packet_put_int(c->host_port);
1239: } else {
1240: /* listen address, port */
1241: packet_put_cstring(c->path);
1242: packet_put_int(c->listening_port);
1243: }
1244: /* originator host and port */
1245: packet_put_cstring(remote_ipaddr);
1.216 markus 1246: packet_put_int((u_int)remote_port);
1.103 markus 1247: packet_send();
1248: } else {
1249: packet_start(SSH_MSG_PORT_OPEN);
1250: packet_put_int(c->self);
1251: packet_put_cstring(c->path);
1252: packet_put_int(c->host_port);
1.121 markus 1253: if (packet_get_protocol_flags() &
1254: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1255: packet_put_cstring(c->remote_name);
1256: packet_send();
1257: }
1258: xfree(remote_ipaddr);
1259: }
1260:
1.226 djm 1261: static void
1262: channel_set_reuseaddr(int fd)
1263: {
1264: int on = 1;
1265:
1266: /*
1267: * Set socket options.
1268: * Allow local port reuse in TIME_WAIT.
1269: */
1270: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1271: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1272: }
1273:
1.41 markus 1274: /*
1275: * This socket is listening for connections to a forwarded TCP/IP port.
1276: */
1.127 itojun 1277: static void
1.41 markus 1278: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1279: {
1.103 markus 1280: Channel *nc;
1.41 markus 1281: struct sockaddr addr;
1.113 markus 1282: int newsock, nextstate;
1.41 markus 1283: socklen_t addrlen;
1.103 markus 1284: char *rtype;
1.73 markus 1285:
1.41 markus 1286: if (FD_ISSET(c->sock, readset)) {
1287: debug("Connection to port %d forwarding "
1288: "to %.100s port %d requested.",
1289: c->listening_port, c->path, c->host_port);
1.103 markus 1290:
1.137 markus 1291: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1292: nextstate = SSH_CHANNEL_OPENING;
1293: rtype = "forwarded-tcpip";
1294: } else {
1295: if (c->host_port == 0) {
1296: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1297: rtype = "dynamic-tcpip";
1.137 markus 1298: } else {
1299: nextstate = SSH_CHANNEL_OPENING;
1300: rtype = "direct-tcpip";
1301: }
1302: }
1.103 markus 1303:
1.41 markus 1304: addrlen = sizeof(addr);
1305: newsock = accept(c->sock, &addr, &addrlen);
1306: if (newsock < 0) {
1307: error("accept: %.100s", strerror(errno));
1308: return;
1309: }
1.169 stevesk 1310: set_nodelay(newsock);
1.190 markus 1311: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1312: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1313: nc->listening_port = c->listening_port;
1314: nc->host_port = c->host_port;
1315: strlcpy(nc->path, c->path, sizeof(nc->path));
1316:
1.137 markus 1317: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1318: /*
1319: * do not call the channel_post handler until
1320: * this flag has been reset by a pre-handler.
1321: * otherwise the FD_ISSET calls might overflow
1322: */
1323: nc->delayed = 1;
1324: } else {
1.103 markus 1325: port_open_helper(nc, rtype);
1.137 markus 1326: }
1.41 markus 1327: }
1328: }
1.25 markus 1329:
1.41 markus 1330: /*
1331: * This is the authentication agent socket listening for connections from
1332: * clients.
1333: */
1.127 itojun 1334: static void
1.41 markus 1335: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1336: {
1.113 markus 1337: Channel *nc;
1338: int newsock;
1.41 markus 1339: struct sockaddr addr;
1340: socklen_t addrlen;
1.25 markus 1341:
1.41 markus 1342: if (FD_ISSET(c->sock, readset)) {
1343: addrlen = sizeof(addr);
1344: newsock = accept(c->sock, &addr, &addrlen);
1345: if (newsock < 0) {
1346: error("accept from auth socket: %.100s", strerror(errno));
1347: return;
1348: }
1.113 markus 1349: nc = channel_new("accepted auth socket",
1.73 markus 1350: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1351: c->local_window_max, c->local_maxpacket,
1.190 markus 1352: 0, "accepted auth socket", 1);
1.73 markus 1353: if (compat20) {
1354: packet_start(SSH2_MSG_CHANNEL_OPEN);
1355: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1356: packet_put_int(nc->self);
1.73 markus 1357: packet_put_int(c->local_window_max);
1358: packet_put_int(c->local_maxpacket);
1359: } else {
1360: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1361: packet_put_int(nc->self);
1.73 markus 1362: }
1.41 markus 1363: packet_send();
1364: }
1365: }
1.25 markus 1366:
1.127 itojun 1367: static void
1.75 markus 1368: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1369: {
1.114 markus 1370: int err = 0;
1.129 stevesk 1371: socklen_t sz = sizeof(err);
1.114 markus 1372:
1.75 markus 1373: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1374: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1375: err = errno;
1376: error("getsockopt SO_ERROR failed");
1377: }
1378: if (err == 0) {
1379: debug("channel %d: connected", c->self);
1380: c->type = SSH_CHANNEL_OPEN;
1381: if (compat20) {
1382: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1383: packet_put_int(c->remote_id);
1384: packet_put_int(c->self);
1385: packet_put_int(c->local_window);
1386: packet_put_int(c->local_maxpacket);
1387: } else {
1388: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1389: packet_put_int(c->remote_id);
1390: packet_put_int(c->self);
1391: }
1.75 markus 1392: } else {
1.114 markus 1393: debug("channel %d: not connected: %s",
1394: c->self, strerror(err));
1395: if (compat20) {
1396: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1397: packet_put_int(c->remote_id);
1398: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1399: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1400: packet_put_cstring(strerror(err));
1401: packet_put_cstring("");
1402: }
1.75 markus 1403: } else {
1.114 markus 1404: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1405: packet_put_int(c->remote_id);
1.75 markus 1406: }
1.114 markus 1407: chan_mark_dead(c);
1.75 markus 1408: }
1.114 markus 1409: packet_send();
1.75 markus 1410: }
1411: }
1412:
1.127 itojun 1413: static int
1.41 markus 1414: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1415: {
1.214 markus 1416: char buf[CHAN_RBUF];
1.41 markus 1417: int len;
1.25 markus 1418:
1.118 markus 1419: if (c->rfd != -1 &&
1.41 markus 1420: FD_ISSET(c->rfd, readset)) {
1421: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1422: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1423: return 1;
1.41 markus 1424: if (len <= 0) {
1.194 markus 1425: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1426: c->self, c->rfd, len);
1.104 markus 1427: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1428: debug2("channel %d: not open", c->self);
1.113 markus 1429: chan_mark_dead(c);
1.103 markus 1430: return -1;
1.104 markus 1431: } else if (compat13) {
1.158 markus 1432: buffer_clear(&c->output);
1.41 markus 1433: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1434: debug2("channel %d: input draining.", c->self);
1.25 markus 1435: } else {
1.41 markus 1436: chan_read_failed(c);
1.25 markus 1437: }
1.41 markus 1438: return -1;
1439: }
1.143 deraadt 1440: if (c->input_filter != NULL) {
1.66 markus 1441: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1442: debug2("channel %d: filter stops", c->self);
1.65 markus 1443: chan_read_failed(c);
1444: }
1.228 reyk 1445: } else if (c->datagram) {
1446: buffer_put_string(&c->input, buf, len);
1.65 markus 1447: } else {
1448: buffer_append(&c->input, buf, len);
1449: }
1.41 markus 1450: }
1451: return 1;
1452: }
1.127 itojun 1453: static int
1.41 markus 1454: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1455: {
1.95 markus 1456: struct termios tio;
1.231 ! reyk 1457: u_char *data = NULL, *buf;
1.134 markus 1458: u_int dlen;
1.41 markus 1459: int len;
1.25 markus 1460:
1.41 markus 1461: /* Send buffered output data to the socket. */
1.118 markus 1462: if (c->wfd != -1 &&
1.41 markus 1463: FD_ISSET(c->wfd, writeset) &&
1464: buffer_len(&c->output) > 0) {
1.231 ! reyk 1465: if (c->output_filter != NULL) {
! 1466: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
! 1467: debug2("channel %d: filter stops", c->self);
! 1468: chan_read_failed(c);
! 1469: }
! 1470: } else if (c->datagram) {
! 1471: buf = data = buffer_get_string(&c->output, &dlen);
! 1472: } else {
! 1473: buf = data = buffer_ptr(&c->output);
! 1474: dlen = buffer_len(&c->output);
! 1475: }
! 1476:
1.228 reyk 1477: if (c->datagram) {
1478: /* ignore truncated writes, datagrams might get lost */
1479: c->local_consumed += dlen + 4;
1.231 ! reyk 1480: len = write(c->wfd, buf, dlen);
1.228 reyk 1481: xfree(data);
1482: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1483: return 1;
1484: if (len <= 0) {
1485: if (c->type != SSH_CHANNEL_OPEN)
1486: chan_mark_dead(c);
1487: else
1488: chan_write_failed(c);
1489: return -1;
1490: }
1491: return 1;
1492: }
1.231 ! reyk 1493:
! 1494: len = write(c->wfd, buf, dlen);
1.53 markus 1495: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1496: return 1;
1.41 markus 1497: if (len <= 0) {
1.104 markus 1498: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1499: debug2("channel %d: not open", c->self);
1.113 markus 1500: chan_mark_dead(c);
1.104 markus 1501: return -1;
1502: } else if (compat13) {
1.158 markus 1503: buffer_clear(&c->output);
1.194 markus 1504: debug2("channel %d: input draining.", c->self);
1.41 markus 1505: c->type = SSH_CHANNEL_INPUT_DRAINING;
1506: } else {
1507: chan_write_failed(c);
1508: }
1509: return -1;
1.91 markus 1510: }
1.231 ! reyk 1511: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1512: if (tcgetattr(c->wfd, &tio) == 0 &&
1513: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1514: /*
1515: * Simulate echo to reduce the impact of
1.96 markus 1516: * traffic analysis. We need to match the
1.95 markus 1517: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 ! reyk 1518: * (4 byte channel id + buf)
1.91 markus 1519: */
1.95 markus 1520: packet_send_ignore(4 + len);
1.91 markus 1521: packet_send();
1522: }
1.25 markus 1523: }
1.41 markus 1524: buffer_consume(&c->output, len);
1.44 markus 1525: if (compat20 && len > 0) {
1526: c->local_consumed += len;
1527: }
1528: }
1529: return 1;
1530: }
1.127 itojun 1531: static int
1.44 markus 1532: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1533: {
1.214 markus 1534: char buf[CHAN_RBUF];
1.44 markus 1535: int len;
1536:
1.45 markus 1537: /** XXX handle drain efd, too */
1.44 markus 1538: if (c->efd != -1) {
1539: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1540: FD_ISSET(c->efd, writeset) &&
1541: buffer_len(&c->extended) > 0) {
1542: len = write(c->efd, buffer_ptr(&c->extended),
1543: buffer_len(&c->extended));
1.70 markus 1544: debug2("channel %d: written %d to efd %d",
1.44 markus 1545: c->self, len, c->efd);
1.93 markus 1546: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1547: return 1;
1548: if (len <= 0) {
1549: debug2("channel %d: closing write-efd %d",
1550: c->self, c->efd);
1.132 markus 1551: channel_close_fd(&c->efd);
1.93 markus 1552: } else {
1.44 markus 1553: buffer_consume(&c->extended, len);
1554: c->local_consumed += len;
1555: }
1556: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1557: FD_ISSET(c->efd, readset)) {
1558: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1559: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1560: c->self, len, c->efd);
1.93 markus 1561: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1562: return 1;
1563: if (len <= 0) {
1564: debug2("channel %d: closing read-efd %d",
1.45 markus 1565: c->self, c->efd);
1.132 markus 1566: channel_close_fd(&c->efd);
1.93 markus 1567: } else {
1.44 markus 1568: buffer_append(&c->extended, buf, len);
1.93 markus 1569: }
1.44 markus 1570: }
1571: }
1572: return 1;
1573: }
1.127 itojun 1574: static int
1.204 djm 1575: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
1576: {
1577: char buf[16];
1578: int len;
1579:
1580: /* Monitor control fd to detect if the slave client exits */
1581: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1582: len = read(c->ctl_fd, buf, sizeof(buf));
1583: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1584: return 1;
1585: if (len <= 0) {
1586: debug2("channel %d: ctl read<=0", c->self);
1587: if (c->type != SSH_CHANNEL_OPEN) {
1588: debug2("channel %d: not open", c->self);
1589: chan_mark_dead(c);
1590: return -1;
1591: } else {
1592: chan_read_failed(c);
1593: chan_write_failed(c);
1594: }
1595: return -1;
1596: } else
1597: fatal("%s: unexpected data on ctl fd", __func__);
1598: }
1599: return 1;
1600: }
1601: static int
1.93 markus 1602: channel_check_window(Channel *c)
1.44 markus 1603: {
1.104 markus 1604: if (c->type == SSH_CHANNEL_OPEN &&
1605: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1606: c->local_window < c->local_window_max/2 &&
1607: c->local_consumed > 0) {
1608: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1609: packet_put_int(c->remote_id);
1610: packet_put_int(c->local_consumed);
1611: packet_send();
1.70 markus 1612: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1613: c->self, c->local_window,
1614: c->local_consumed);
1615: c->local_window += c->local_consumed;
1616: c->local_consumed = 0;
1.1 deraadt 1617: }
1.41 markus 1618: return 1;
1.1 deraadt 1619: }
1620:
1.127 itojun 1621: static void
1.157 markus 1622: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1623: {
1.137 markus 1624: if (c->delayed)
1625: return;
1.41 markus 1626: channel_handle_rfd(c, readset, writeset);
1627: channel_handle_wfd(c, readset, writeset);
1.157 markus 1628: if (!compat20)
1.137 markus 1629: return;
1.44 markus 1630: channel_handle_efd(c, readset, writeset);
1.204 djm 1631: channel_handle_ctl(c, readset, writeset);
1.93 markus 1632: channel_check_window(c);
1.44 markus 1633: }
1634:
1.127 itojun 1635: static void
1.41 markus 1636: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1637: {
1.41 markus 1638: int len;
1.180 deraadt 1639:
1.41 markus 1640: /* Send buffered output data to the socket. */
1641: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1642: len = write(c->sock, buffer_ptr(&c->output),
1643: buffer_len(&c->output));
1644: if (len <= 0)
1.158 markus 1645: buffer_clear(&c->output);
1.41 markus 1646: else
1647: buffer_consume(&c->output, len);
1648: }
1649: }
1.25 markus 1650:
1.127 itojun 1651: static void
1.44 markus 1652: channel_handler_init_20(void)
1653: {
1.157 markus 1654: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1655: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1656: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1657: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1658: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1659: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1660: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1661: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1662:
1.157 markus 1663: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1664: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1665: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1666: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1667: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1668: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1669: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1670: }
1671:
1.127 itojun 1672: static void
1.41 markus 1673: channel_handler_init_13(void)
1674: {
1675: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1676: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1677: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1678: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1679: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1680: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1681: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1682: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1683: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1684:
1.157 markus 1685: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1686: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1687: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1688: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1689: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1690: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1691: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1692: }
1.25 markus 1693:
1.127 itojun 1694: static void
1.41 markus 1695: channel_handler_init_15(void)
1696: {
1.157 markus 1697: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1698: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1699: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1700: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1701: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1702: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1703: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1704:
1.41 markus 1705: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1706: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1707: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1708: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1709: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1710: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1711: }
1.27 markus 1712:
1.127 itojun 1713: static void
1.41 markus 1714: channel_handler_init(void)
1715: {
1716: int i;
1.180 deraadt 1717:
1.148 deraadt 1718: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1719: channel_pre[i] = NULL;
1720: channel_post[i] = NULL;
1721: }
1.44 markus 1722: if (compat20)
1723: channel_handler_init_20();
1724: else if (compat13)
1.41 markus 1725: channel_handler_init_13();
1726: else
1727: channel_handler_init_15();
1728: }
1.25 markus 1729:
1.140 markus 1730: /* gc dead channels */
1731: static void
1732: channel_garbage_collect(Channel *c)
1733: {
1734: if (c == NULL)
1735: return;
1736: if (c->detach_user != NULL) {
1.225 djm 1737: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1738: return;
1.194 markus 1739: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1740: c->detach_user(c->self, NULL);
1741: /* if we still have a callback */
1742: if (c->detach_user != NULL)
1743: return;
1.194 markus 1744: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1745: }
1746: if (!chan_is_dead(c, 1))
1747: return;
1.194 markus 1748: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1749: channel_free(c);
1750: }
1751:
1.127 itojun 1752: static void
1.41 markus 1753: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1754: {
1755: static int did_init = 0;
1.209 avsm 1756: u_int i;
1.41 markus 1757: Channel *c;
1.25 markus 1758:
1.41 markus 1759: if (!did_init) {
1760: channel_handler_init();
1761: did_init = 1;
1762: }
1763: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1764: c = channels[i];
1765: if (c == NULL)
1.41 markus 1766: continue;
1.118 markus 1767: if (ftab[c->type] != NULL)
1768: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1769: channel_garbage_collect(c);
1.1 deraadt 1770: }
1771: }
1772:
1.121 markus 1773: /*
1774: * Allocate/update select bitmasks and add any bits relevant to channels in
1775: * select bitmasks.
1776: */
1.49 markus 1777: void
1.100 markus 1778: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1779: u_int *nallocp, int rekeying)
1.41 markus 1780: {
1.209 avsm 1781: u_int n, sz;
1.84 markus 1782:
1783: n = MAX(*maxfdp, channel_max_fd);
1784:
1785: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1786: /* perhaps check sz < nalloc/2 and shrink? */
1787: if (*readsetp == NULL || sz > *nallocp) {
1788: *readsetp = xrealloc(*readsetp, sz);
1789: *writesetp = xrealloc(*writesetp, sz);
1790: *nallocp = sz;
1.84 markus 1791: }
1.132 markus 1792: *maxfdp = n;
1.84 markus 1793: memset(*readsetp, 0, sz);
1794: memset(*writesetp, 0, sz);
1795:
1.100 markus 1796: if (!rekeying)
1797: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1798: }
1799:
1.121 markus 1800: /*
1801: * After select, perform any appropriate operations for channels which have
1802: * events pending.
1803: */
1.49 markus 1804: void
1.41 markus 1805: channel_after_select(fd_set * readset, fd_set * writeset)
1806: {
1807: channel_handler(channel_post, readset, writeset);
1808: }
1809:
1.121 markus 1810:
1.84 markus 1811: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1812:
1.49 markus 1813: void
1.142 itojun 1814: channel_output_poll(void)
1.1 deraadt 1815: {
1.41 markus 1816: Channel *c;
1.209 avsm 1817: u_int i, len;
1.1 deraadt 1818:
1.25 markus 1819: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1820: c = channels[i];
1821: if (c == NULL)
1822: continue;
1.37 markus 1823:
1.121 markus 1824: /*
1825: * We are only interested in channels that can have buffered
1826: * incoming data.
1827: */
1.37 markus 1828: if (compat13) {
1.41 markus 1829: if (c->type != SSH_CHANNEL_OPEN &&
1830: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1831: continue;
1832: } else {
1.41 markus 1833: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1834: continue;
1835: }
1.46 markus 1836: if (compat20 &&
1837: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1838: /* XXX is this true? */
1.140 markus 1839: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1840: continue;
1841: }
1.25 markus 1842:
1843: /* Get the amount of buffered data for this channel. */
1.93 markus 1844: if ((c->istate == CHAN_INPUT_OPEN ||
1845: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1846: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1847: if (c->datagram) {
1848: if (len > 0) {
1849: u_char *data;
1850: u_int dlen;
1851:
1852: data = buffer_get_string(&c->input,
1853: &dlen);
1854: packet_start(SSH2_MSG_CHANNEL_DATA);
1855: packet_put_int(c->remote_id);
1856: packet_put_string(data, dlen);
1857: packet_send();
1858: c->remote_window -= dlen + 4;
1859: xfree(data);
1860: }
1861: continue;
1862: }
1.121 markus 1863: /*
1864: * Send some data for the other side over the secure
1865: * connection.
1866: */
1.44 markus 1867: if (compat20) {
1868: if (len > c->remote_window)
1869: len = c->remote_window;
1870: if (len > c->remote_maxpacket)
1871: len = c->remote_maxpacket;
1.25 markus 1872: } else {
1.44 markus 1873: if (packet_is_interactive()) {
1874: if (len > 1024)
1875: len = 512;
1876: } else {
1877: /* Keep the packets at reasonable size. */
1878: if (len > packet_get_maxsize()/2)
1879: len = packet_get_maxsize()/2;
1880: }
1.25 markus 1881: }
1.41 markus 1882: if (len > 0) {
1.44 markus 1883: packet_start(compat20 ?
1884: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1885: packet_put_int(c->remote_id);
1886: packet_put_string(buffer_ptr(&c->input), len);
1887: packet_send();
1888: buffer_consume(&c->input, len);
1889: c->remote_window -= len;
1890: }
1891: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1892: if (compat13)
1893: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1894: /*
1895: * input-buffer is empty and read-socket shutdown:
1.172 markus 1896: * tell peer, that we will not send more data: send IEOF.
1897: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1898: */
1.172 markus 1899: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1900: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1901: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1902: else
1903: chan_ibuf_empty(c);
1.25 markus 1904: }
1.44 markus 1905: /* Send extended data, i.e. stderr */
1906: if (compat20 &&
1.172 markus 1907: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1908: c->remote_window > 0 &&
1909: (len = buffer_len(&c->extended)) > 0 &&
1910: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1911: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1912: c->self, c->remote_window, buffer_len(&c->extended),
1913: c->extended_usage);
1.44 markus 1914: if (len > c->remote_window)
1915: len = c->remote_window;
1916: if (len > c->remote_maxpacket)
1917: len = c->remote_maxpacket;
1918: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1919: packet_put_int(c->remote_id);
1920: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1921: packet_put_string(buffer_ptr(&c->extended), len);
1922: packet_send();
1923: buffer_consume(&c->extended, len);
1924: c->remote_window -= len;
1.93 markus 1925: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1926: }
1.25 markus 1927: }
1.1 deraadt 1928: }
1929:
1.121 markus 1930:
1931: /* -- protocol input */
1.1 deraadt 1932:
1.49 markus 1933: void
1.154 markus 1934: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1935: {
1.37 markus 1936: int id;
1.25 markus 1937: char *data;
1.77 markus 1938: u_int data_len;
1.41 markus 1939: Channel *c;
1.25 markus 1940:
1941: /* Get the channel number and verify it. */
1.37 markus 1942: id = packet_get_int();
1.41 markus 1943: c = channel_lookup(id);
1944: if (c == NULL)
1.37 markus 1945: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1946:
1947: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1948: if (c->type != SSH_CHANNEL_OPEN &&
1949: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1950: return;
1951:
1.25 markus 1952: /* Get the data. */
1953: data = packet_get_string(&data_len);
1.200 markus 1954:
1955: /*
1956: * Ignore data for protocol > 1.3 if output end is no longer open.
1957: * For protocol 2 the sending side is reducing its window as it sends
1958: * data, so we must 'fake' consumption of the data in order to ensure
1959: * that window updates are sent back. Otherwise the connection might
1960: * deadlock.
1961: */
1962: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1963: if (compat20) {
1964: c->local_window -= data_len;
1965: c->local_consumed += data_len;
1966: }
1967: xfree(data);
1968: return;
1969: }
1.41 markus 1970:
1.143 deraadt 1971: if (compat20) {
1.44 markus 1972: if (data_len > c->local_maxpacket) {
1.188 itojun 1973: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1974: c->self, data_len, c->local_maxpacket);
1975: }
1976: if (data_len > c->local_window) {
1.188 itojun 1977: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1978: c->self, data_len, c->local_window);
1979: xfree(data);
1980: return;
1981: }
1982: c->local_window -= data_len;
1983: }
1.152 markus 1984: packet_check_eom();
1.228 reyk 1985: if (c->datagram)
1986: buffer_put_string(&c->output, data, data_len);
1987: else
1988: buffer_append(&c->output, data, data_len);
1.25 markus 1989: xfree(data);
1.1 deraadt 1990: }
1.121 markus 1991:
1.49 markus 1992: void
1.154 markus 1993: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1994: {
1995: int id;
1996: char *data;
1.177 markus 1997: u_int data_len, tcode;
1.44 markus 1998: Channel *c;
1999:
2000: /* Get the channel number and verify it. */
2001: id = packet_get_int();
2002: c = channel_lookup(id);
2003:
2004: if (c == NULL)
2005: packet_disconnect("Received extended_data for bad channel %d.", id);
2006: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2007: logit("channel %d: ext data for non open", id);
1.44 markus 2008: return;
1.172 markus 2009: }
2010: if (c->flags & CHAN_EOF_RCVD) {
2011: if (datafellows & SSH_BUG_EXTEOF)
2012: debug("channel %d: accepting ext data after eof", id);
2013: else
2014: packet_disconnect("Received extended_data after EOF "
2015: "on channel %d.", id);
1.44 markus 2016: }
2017: tcode = packet_get_int();
2018: if (c->efd == -1 ||
2019: c->extended_usage != CHAN_EXTENDED_WRITE ||
2020: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2021: logit("channel %d: bad ext data", c->self);
1.44 markus 2022: return;
2023: }
2024: data = packet_get_string(&data_len);
1.152 markus 2025: packet_check_eom();
1.44 markus 2026: if (data_len > c->local_window) {
1.188 itojun 2027: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2028: c->self, data_len, c->local_window);
2029: xfree(data);
2030: return;
2031: }
1.70 markus 2032: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2033: c->local_window -= data_len;
2034: buffer_append(&c->extended, data, data_len);
2035: xfree(data);
2036: }
2037:
1.49 markus 2038: void
1.154 markus 2039: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2040: {
2041: int id;
2042: Channel *c;
2043:
2044: id = packet_get_int();
1.152 markus 2045: packet_check_eom();
1.41 markus 2046: c = channel_lookup(id);
2047: if (c == NULL)
2048: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2049: chan_rcvd_ieof(c);
1.133 markus 2050:
2051: /* XXX force input close */
1.156 markus 2052: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2053: debug("channel %d: FORCE input drain", c->self);
2054: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2055: if (buffer_len(&c->input) == 0)
2056: chan_ibuf_empty(c);
1.133 markus 2057: }
2058:
1.41 markus 2059: }
1.1 deraadt 2060:
1.49 markus 2061: void
1.154 markus 2062: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2063: {
1.41 markus 2064: int id;
2065: Channel *c;
1.1 deraadt 2066:
1.41 markus 2067: id = packet_get_int();
1.152 markus 2068: packet_check_eom();
1.41 markus 2069: c = channel_lookup(id);
2070: if (c == NULL)
2071: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2072:
2073: /*
2074: * Send a confirmation that we have closed the channel and no more
2075: * data is coming for it.
2076: */
1.25 markus 2077: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2078: packet_put_int(c->remote_id);
1.25 markus 2079: packet_send();
2080:
1.27 markus 2081: /*
2082: * If the channel is in closed state, we have sent a close request,
2083: * and the other side will eventually respond with a confirmation.
2084: * Thus, we cannot free the channel here, because then there would be
2085: * no-one to receive the confirmation. The channel gets freed when
2086: * the confirmation arrives.
2087: */
1.41 markus 2088: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2089: /*
2090: * Not a closed channel - mark it as draining, which will
2091: * cause it to be freed later.
2092: */
1.158 markus 2093: buffer_clear(&c->input);
1.41 markus 2094: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2095: }
1.1 deraadt 2096: }
2097:
1.41 markus 2098: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 2099: void
1.154 markus 2100: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2101: {
2102: int id = packet_get_int();
2103: Channel *c = channel_lookup(id);
1.151 markus 2104:
1.152 markus 2105: packet_check_eom();
1.41 markus 2106: if (c == NULL)
2107: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2108: chan_rcvd_oclose(c);
2109: }
1.1 deraadt 2110:
1.49 markus 2111: void
1.154 markus 2112: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2113: {
1.41 markus 2114: int id = packet_get_int();
2115: Channel *c = channel_lookup(id);
1.1 deraadt 2116:
1.152 markus 2117: packet_check_eom();
1.41 markus 2118: if (c == NULL)
2119: packet_disconnect("Received close confirmation for "
2120: "out-of-range channel %d.", id);
2121: if (c->type != SSH_CHANNEL_CLOSED)
2122: packet_disconnect("Received close confirmation for "
2123: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2124: channel_free(c);
1.1 deraadt 2125: }
2126:
1.49 markus 2127: void
1.154 markus 2128: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2129: {
1.41 markus 2130: int id, remote_id;
2131: Channel *c;
1.1 deraadt 2132:
1.41 markus 2133: id = packet_get_int();
2134: c = channel_lookup(id);
1.25 markus 2135:
1.41 markus 2136: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2137: packet_disconnect("Received open confirmation for "
2138: "non-opening channel %d.", id);
2139: remote_id = packet_get_int();
1.27 markus 2140: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2141: c->remote_id = remote_id;
2142: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2143:
2144: if (compat20) {
2145: c->remote_window = packet_get_int();
2146: c->remote_maxpacket = packet_get_int();
1.165 markus 2147: if (c->confirm) {
1.70 markus 2148: debug2("callback start");
1.204 djm 2149: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2150: debug2("callback done");
1.44 markus 2151: }
1.194 markus 2152: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2153: c->remote_window, c->remote_maxpacket);
2154: }
1.152 markus 2155: packet_check_eom();
1.1 deraadt 2156: }
2157:
1.127 itojun 2158: static char *
1.114 markus 2159: reason2txt(int reason)
2160: {
1.143 deraadt 2161: switch (reason) {
1.114 markus 2162: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2163: return "administratively prohibited";
2164: case SSH2_OPEN_CONNECT_FAILED:
2165: return "connect failed";
2166: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2167: return "unknown channel type";
2168: case SSH2_OPEN_RESOURCE_SHORTAGE:
2169: return "resource shortage";
2170: }
1.117 stevesk 2171: return "unknown reason";
1.114 markus 2172: }
2173:
1.49 markus 2174: void
1.154 markus 2175: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2176: {
1.86 markus 2177: int id, reason;
2178: char *msg = NULL, *lang = NULL;
1.41 markus 2179: Channel *c;
2180:
2181: id = packet_get_int();
2182: c = channel_lookup(id);
1.25 markus 2183:
1.41 markus 2184: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2185: packet_disconnect("Received open failure for "
2186: "non-opening channel %d.", id);
1.44 markus 2187: if (compat20) {
1.86 markus 2188: reason = packet_get_int();
1.110 markus 2189: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2190: msg = packet_get_string(NULL);
2191: lang = packet_get_string(NULL);
2192: }
1.188 itojun 2193: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2194: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2195: if (msg != NULL)
2196: xfree(msg);
2197: if (lang != NULL)
2198: xfree(lang);
1.44 markus 2199: }
1.152 markus 2200: packet_check_eom();
1.25 markus 2201: /* Free the channel. This will also close the socket. */
1.113 markus 2202: channel_free(c);
1.44 markus 2203: }
2204:
1.121 markus 2205: void
1.154 markus 2206: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2207: {
2208: Channel *c;
1.178 markus 2209: int id;
2210: u_int adjust;
1.121 markus 2211:
2212: if (!compat20)
2213: return;
2214:
2215: /* Get the channel number and verify it. */
2216: id = packet_get_int();
2217: c = channel_lookup(id);
1.1 deraadt 2218:
1.229 markus 2219: if (c == NULL) {
2220: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2221: return;
2222: }
2223: adjust = packet_get_int();
1.152 markus 2224: packet_check_eom();
1.178 markus 2225: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2226: c->remote_window += adjust;
2227: }
1.1 deraadt 2228:
1.121 markus 2229: void
1.154 markus 2230: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2231: {
1.121 markus 2232: Channel *c = NULL;
2233: u_short host_port;
2234: char *host, *originator_string;
2235: int remote_id, sock = -1;
2236:
2237: remote_id = packet_get_int();
2238: host = packet_get_string(NULL);
2239: host_port = packet_get_int();
1.25 markus 2240:
1.121 markus 2241: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2242: originator_string = packet_get_string(NULL);
2243: } else {
2244: originator_string = xstrdup("unknown (remote did not supply name)");
2245: }
1.152 markus 2246: packet_check_eom();
1.121 markus 2247: sock = channel_connect_to(host, host_port);
2248: if (sock != -1) {
2249: c = channel_new("connected socket",
2250: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2251: originator_string, 1);
1.167 markus 2252: c->remote_id = remote_id;
1.25 markus 2253: }
1.190 markus 2254: xfree(originator_string);
1.121 markus 2255: if (c == NULL) {
2256: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2257: packet_put_int(remote_id);
2258: packet_send();
2259: }
2260: xfree(host);
1.1 deraadt 2261: }
2262:
1.121 markus 2263:
2264: /* -- tcp forwarding */
1.135 markus 2265:
2266: void
2267: channel_set_af(int af)
2268: {
2269: IPv4or6 = af;
2270: }
1.121 markus 2271:
1.160 markus 2272: static int
2273: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2274: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2275: {
1.113 markus 2276: Channel *c;
1.226 djm 2277: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2278: struct addrinfo hints, *ai, *aitop;
1.212 djm 2279: const char *host, *addr;
1.35 markus 2280: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2281:
1.160 markus 2282: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2283: listen_addr : host_to_connect;
1.212 djm 2284: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2285:
1.160 markus 2286: if (host == NULL) {
2287: error("No forward host name.");
1.218 markus 2288: return 0;
1.73 markus 2289: }
1.113 markus 2290: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2291: error("Forward host name too long.");
1.218 markus 2292: return 0;
1.87 markus 2293: }
1.25 markus 2294:
1.28 markus 2295: /*
1.212 djm 2296: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2297: * specified address or wildcard. On the client, a specified bind
2298: * address will always override gateway_ports. On the server, a
2299: * gateway_ports of 1 (``yes'') will override the client's
2300: * specification and force a wildcard bind, whereas a value of 2
2301: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2302: * asked for.
2303: *
2304: * Special-case listen_addrs are:
2305: *
2306: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2307: * "" (empty string), "*" -> wildcard v4/v6
2308: * "localhost" -> loopback v4/v6
2309: */
2310: addr = NULL;
2311: if (listen_addr == NULL) {
2312: /* No address specified: default to gateway_ports setting */
2313: if (gateway_ports)
2314: wildcard = 1;
2315: } else if (gateway_ports || is_client) {
2316: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2317: strcmp(listen_addr, "0.0.0.0") == 0) ||
2318: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2319: (!is_client && gateway_ports == 1))
2320: wildcard = 1;
2321: else if (strcmp(listen_addr, "localhost") != 0)
2322: addr = listen_addr;
2323: }
2324:
2325: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2326: type, wildcard, (addr == NULL) ? "NULL" : addr);
2327:
2328: /*
1.35 markus 2329: * getaddrinfo returns a loopback address if the hostname is
2330: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2331: */
1.35 markus 2332: memset(&hints, 0, sizeof(hints));
2333: hints.ai_family = IPv4or6;
1.212 djm 2334: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2335: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2336: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2337: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2338: if (addr == NULL) {
2339: /* This really shouldn't happen */
2340: packet_disconnect("getaddrinfo: fatal error: %s",
2341: gai_strerror(r));
2342: } else {
1.218 markus 2343: error("channel_setup_fwd_listener: "
1.212 djm 2344: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2345: }
1.218 markus 2346: return 0;
1.212 djm 2347: }
1.35 markus 2348:
2349: for (ai = aitop; ai; ai = ai->ai_next) {
2350: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2351: continue;
2352: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2353: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2354: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2355: continue;
2356: }
2357: /* Create a port to listen for the host. */
1.189 markus 2358: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2359: if (sock < 0) {
2360: /* this is no error since kernel may not support ipv6 */
2361: verbose("socket: %.100s", strerror(errno));
2362: continue;
2363: }
1.226 djm 2364:
2365: channel_set_reuseaddr(sock);
1.182 stevesk 2366:
1.35 markus 2367: debug("Local forwarding listening on %s port %s.", ntop, strport);
2368:
2369: /* Bind the socket to the address. */
2370: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2371: /* address can be in use ipv6 address is already bound */
2372: verbose("bind: %.100s", strerror(errno));
2373: close(sock);
2374: continue;
2375: }
2376: /* Start listening for connections on the socket. */
1.199 markus 2377: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2378: error("listen: %.100s", strerror(errno));
2379: close(sock);
2380: continue;
2381: }
2382: /* Allocate a channel number for the socket. */
1.121 markus 2383: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2384: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2385: 0, "port listener", 1);
1.113 markus 2386: strlcpy(c->path, host, sizeof(c->path));
2387: c->host_port = port_to_connect;
2388: c->listening_port = listen_port;
1.35 markus 2389: success = 1;
2390: }
2391: if (success == 0)
1.160 markus 2392: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2393: listen_port);
1.35 markus 2394: freeaddrinfo(aitop);
1.87 markus 2395: return success;
1.25 markus 2396: }
1.1 deraadt 2397:
1.202 djm 2398: int
2399: channel_cancel_rport_listener(const char *host, u_short port)
2400: {
1.209 avsm 2401: u_int i;
2402: int found = 0;
1.202 djm 2403:
1.213 deraadt 2404: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2405: Channel *c = channels[i];
2406:
2407: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2408: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2409: c->listening_port == port) {
1.210 djm 2410: debug2("%s: close channel %d", __func__, i);
1.202 djm 2411: channel_free(c);
2412: found = 1;
2413: }
2414: }
2415:
2416: return (found);
2417: }
2418:
1.160 markus 2419: /* protocol local port fwd, used by ssh (and sshd in v1) */
2420: int
1.212 djm 2421: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2422: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2423: {
2424: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2425: listen_host, listen_port, host_to_connect, port_to_connect,
2426: gateway_ports);
1.160 markus 2427: }
2428:
2429: /* protocol v2 remote port fwd, used by sshd */
2430: int
2431: channel_setup_remote_fwd_listener(const char *listen_address,
2432: u_short listen_port, int gateway_ports)
2433: {
2434: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2435: listen_address, listen_port, NULL, 0, gateway_ports);
2436: }
2437:
1.27 markus 2438: /*
2439: * Initiate forwarding of connections to port "port" on remote host through
2440: * the secure channel to host:port from local side.
2441: */
1.1 deraadt 2442:
1.49 markus 2443: void
1.212 djm 2444: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2445: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2446: {
1.153 markus 2447: int type, success = 0;
1.73 markus 2448:
1.25 markus 2449: /* Record locally that connection to this host/port is permitted. */
2450: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2451: fatal("channel_request_remote_forwarding: too many forwards");
2452:
2453: /* Send the forward request to the remote side. */
1.44 markus 2454: if (compat20) {
1.212 djm 2455: const char *address_to_bind;
2456: if (listen_host == NULL)
2457: address_to_bind = "localhost";
2458: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2459: address_to_bind = "";
2460: else
2461: address_to_bind = listen_host;
2462:
1.44 markus 2463: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2464: packet_put_cstring("tcpip-forward");
1.173 markus 2465: packet_put_char(1); /* boolean: want reply */
1.44 markus 2466: packet_put_cstring(address_to_bind);
2467: packet_put_int(listen_port);
1.73 markus 2468: packet_send();
2469: packet_write_wait();
2470: /* Assume that server accepts the request */
2471: success = 1;
1.44 markus 2472: } else {
2473: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2474: packet_put_int(listen_port);
2475: packet_put_cstring(host_to_connect);
1.44 markus 2476: packet_put_int(port_to_connect);
2477: packet_send();
2478: packet_write_wait();
1.73 markus 2479:
2480: /* Wait for response from the remote side. */
1.153 markus 2481: type = packet_read();
1.73 markus 2482: switch (type) {
2483: case SSH_SMSG_SUCCESS:
2484: success = 1;
2485: break;
2486: case SSH_SMSG_FAILURE:
1.188 itojun 2487: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2488: break;
2489: default:
2490: /* Unknown packet */
2491: packet_disconnect("Protocol error for port forward request:"
2492: "received packet type %d.", type);
2493: }
2494: }
2495: if (success) {
2496: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2497: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2498: permitted_opens[num_permitted_opens].listen_port = listen_port;
2499: num_permitted_opens++;
1.44 markus 2500: }
1.1 deraadt 2501: }
2502:
1.27 markus 2503: /*
1.208 deraadt 2504: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2505: * local side.
2506: */
2507: void
1.212 djm 2508: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2509: {
2510: int i;
2511:
2512: if (!compat20)
2513: return;
2514:
2515: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2516: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2517: permitted_opens[i].listen_port == port)
2518: break;
2519: }
2520: if (i >= num_permitted_opens) {
2521: debug("%s: requested forward not found", __func__);
2522: return;
2523: }
2524: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2525: packet_put_cstring("cancel-tcpip-forward");
2526: packet_put_char(0);
1.212 djm 2527: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2528: packet_put_int(port);
2529: packet_send();
2530:
2531: permitted_opens[i].listen_port = 0;
2532: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2533: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2534: permitted_opens[i].host_to_connect = NULL;
2535: }
2536:
2537: /*
1.27 markus 2538: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2539: * listening for the port, and sends back a success reply (or disconnect
2540: * message if there was an error). This never returns if there was an error.
2541: */
1.1 deraadt 2542:
1.49 markus 2543: void
1.56 markus 2544: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2545: {
1.31 markus 2546: u_short port, host_port;
1.25 markus 2547: char *hostname;
1.1 deraadt 2548:
1.25 markus 2549: /* Get arguments from the packet. */
2550: port = packet_get_int();
2551: hostname = packet_get_string(NULL);
2552: host_port = packet_get_int();
2553:
1.27 markus 2554: /*
2555: * Check that an unprivileged user is not trying to forward a
2556: * privileged port.
2557: */
1.25 markus 2558: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2559: packet_disconnect(
2560: "Requested forwarding of port %d but user is not root.",
2561: port);
2562: if (host_port == 0)
2563: packet_disconnect("Dynamic forwarding denied.");
2564:
1.73 markus 2565: /* Initiate forwarding */
1.212 djm 2566: channel_setup_local_fwd_listener(NULL, port, hostname,
2567: host_port, gateway_ports);
1.25 markus 2568:
2569: /* Free the argument string. */
2570: xfree(hostname);
1.1 deraadt 2571: }
2572:
1.99 markus 2573: /*
2574: * Permits opening to any host/port if permitted_opens[] is empty. This is
2575: * usually called by the server, because the user could connect to any port
2576: * anyway, and the server has no way to know but to trust the client anyway.
2577: */
2578: void
1.142 itojun 2579: channel_permit_all_opens(void)
1.99 markus 2580: {
2581: if (num_permitted_opens == 0)
2582: all_opens_permitted = 1;
2583: }
2584:
1.101 markus 2585: void
1.99 markus 2586: channel_add_permitted_opens(char *host, int port)
2587: {
2588: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2589: fatal("channel_request_remote_forwarding: too many forwards");
2590: debug("allow port forwarding to host %s port %d", host, port);
2591:
2592: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2593: permitted_opens[num_permitted_opens].port_to_connect = port;
2594: num_permitted_opens++;
2595:
2596: all_opens_permitted = 0;
2597: }
2598:
1.101 markus 2599: void
1.99 markus 2600: channel_clear_permitted_opens(void)
2601: {
2602: int i;
2603:
2604: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2605: if (permitted_opens[i].host_to_connect != NULL)
2606: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2607: num_permitted_opens = 0;
2608:
2609: }
2610:
2611:
2612: /* return socket to remote host, port */
1.127 itojun 2613: static int
1.99 markus 2614: connect_to(const char *host, u_short port)
1.41 markus 2615: {
2616: struct addrinfo hints, *ai, *aitop;
2617: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2618: int gaierr;
2619: int sock = -1;
2620:
2621: memset(&hints, 0, sizeof(hints));
2622: hints.ai_family = IPv4or6;
2623: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2624: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2625: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2626: error("connect_to %.100s: unknown host (%s)", host,
2627: gai_strerror(gaierr));
1.41 markus 2628: return -1;
2629: }
2630: for (ai = aitop; ai; ai = ai->ai_next) {
2631: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2632: continue;
2633: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2634: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2635: error("connect_to: getnameinfo failed");
1.41 markus 2636: continue;
2637: }
1.189 markus 2638: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2639: if (sock < 0) {
1.186 djm 2640: if (ai->ai_next == NULL)
2641: error("socket: %.100s", strerror(errno));
2642: else
2643: verbose("socket: %.100s", strerror(errno));
1.41 markus 2644: continue;
2645: }
1.205 djm 2646: if (set_nonblock(sock) == -1)
2647: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2648: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2649: errno != EINPROGRESS) {
1.99 markus 2650: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2651: strerror(errno));
2652: close(sock);
1.89 stevesk 2653: continue; /* fail -- try next */
1.41 markus 2654: }
2655: break; /* success */
2656:
2657: }
2658: freeaddrinfo(aitop);
2659: if (!ai) {
1.99 markus 2660: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2661: return -1;
2662: }
2663: /* success */
1.169 stevesk 2664: set_nodelay(sock);
1.41 markus 2665: return sock;
2666: }
1.99 markus 2667:
1.73 markus 2668: int
1.130 stevesk 2669: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2670: {
2671: int i;
1.99 markus 2672:
1.73 markus 2673: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2674: if (permitted_opens[i].host_to_connect != NULL &&
2675: permitted_opens[i].listen_port == listen_port)
1.99 markus 2676: return connect_to(
1.73 markus 2677: permitted_opens[i].host_to_connect,
2678: permitted_opens[i].port_to_connect);
1.74 markus 2679: error("WARNING: Server requests forwarding for unknown listen_port %d",
2680: listen_port);
1.73 markus 2681: return -1;
2682: }
2683:
1.99 markus 2684: /* Check if connecting to that port is permitted and connect. */
2685: int
2686: channel_connect_to(const char *host, u_short port)
2687: {
2688: int i, permit;
2689:
2690: permit = all_opens_permitted;
2691: if (!permit) {
2692: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2693: if (permitted_opens[i].host_to_connect != NULL &&
2694: permitted_opens[i].port_to_connect == port &&
1.99 markus 2695: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2696: permit = 1;
2697:
2698: }
2699: if (!permit) {
1.188 itojun 2700: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2701: "but the request was denied.", host, port);
2702: return -1;
2703: }
2704: return connect_to(host, port);
1.204 djm 2705: }
2706:
2707: void
2708: channel_send_window_changes(void)
2709: {
1.209 avsm 2710: u_int i;
1.204 djm 2711: struct winsize ws;
2712:
2713: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2714: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2715: channels[i]->type != SSH_CHANNEL_OPEN)
2716: continue;
2717: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2718: continue;
2719: channel_request_start(i, "window-change", 0);
2720: packet_put_int(ws.ws_col);
2721: packet_put_int(ws.ws_row);
2722: packet_put_int(ws.ws_xpixel);
2723: packet_put_int(ws.ws_ypixel);
2724: packet_send();
2725: }
1.99 markus 2726: }
2727:
1.121 markus 2728: /* -- X11 forwarding */
1.1 deraadt 2729:
1.27 markus 2730: /*
2731: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2732: * Returns 0 and a suitable display number for the DISPLAY variable
2733: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2734: */
1.141 stevesk 2735: int
1.163 stevesk 2736: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2737: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2738: {
1.149 markus 2739: Channel *nc = NULL;
1.31 markus 2740: int display_number, sock;
2741: u_short port;
1.35 markus 2742: struct addrinfo hints, *ai, *aitop;
2743: char strport[NI_MAXSERV];
2744: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2745:
1.224 markus 2746: if (chanids == NULL)
2747: return -1;
2748:
1.33 markus 2749: for (display_number = x11_display_offset;
1.148 deraadt 2750: display_number < MAX_DISPLAYS;
2751: display_number++) {
1.25 markus 2752: port = 6000 + display_number;
1.35 markus 2753: memset(&hints, 0, sizeof(hints));
2754: hints.ai_family = IPv4or6;
1.163 stevesk 2755: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2756: hints.ai_socktype = SOCK_STREAM;
2757: snprintf(strport, sizeof strport, "%d", port);
2758: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2759: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2760: return -1;
1.25 markus 2761: }
1.35 markus 2762: for (ai = aitop; ai; ai = ai->ai_next) {
2763: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2764: continue;
1.189 markus 2765: sock = socket(ai->ai_family, ai->ai_socktype,
2766: ai->ai_protocol);
1.35 markus 2767: if (sock < 0) {
2768: error("socket: %.100s", strerror(errno));
1.203 markus 2769: freeaddrinfo(aitop);
1.141 stevesk 2770: return -1;
1.35 markus 2771: }
1.226 djm 2772: channel_set_reuseaddr(sock);
1.35 markus 2773: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2774: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2775: close(sock);
1.183 itojun 2776:
2777: if (ai->ai_next)
2778: continue;
2779:
1.35 markus 2780: for (n = 0; n < num_socks; n++) {
2781: close(socks[n]);
2782: }
2783: num_socks = 0;
2784: break;
2785: }
2786: socks[num_socks++] = sock;
2787: if (num_socks == NUM_SOCKS)
2788: break;
1.25 markus 2789: }
1.83 stevesk 2790: freeaddrinfo(aitop);
1.35 markus 2791: if (num_socks > 0)
2792: break;
1.25 markus 2793: }
2794: if (display_number >= MAX_DISPLAYS) {
2795: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2796: return -1;
1.25 markus 2797: }
2798: /* Start listening for connections on the socket. */
1.35 markus 2799: for (n = 0; n < num_socks; n++) {
2800: sock = socks[n];
1.199 markus 2801: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2802: error("listen: %.100s", strerror(errno));
2803: close(sock);
1.141 stevesk 2804: return -1;
1.35 markus 2805: }
1.25 markus 2806: }
1.35 markus 2807:
2808: /* Allocate a channel for each socket. */
1.224 markus 2809: *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1));
1.35 markus 2810: for (n = 0; n < num_socks; n++) {
2811: sock = socks[n];
1.149 markus 2812: nc = channel_new("x11 listener",
1.51 markus 2813: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2814: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2815: 0, "X11 inet listener", 1);
1.167 markus 2816: nc->single_connection = single_connection;
1.224 markus 2817: (*chanids)[n] = nc->self;
1.35 markus 2818: }
1.224 markus 2819: (*chanids)[n] = -1;
1.1 deraadt 2820:
1.141 stevesk 2821: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2822: *display_numberp = display_number;
2823: return (0);
1.1 deraadt 2824: }
2825:
1.127 itojun 2826: static int
1.77 markus 2827: connect_local_xsocket(u_int dnr)
1.1 deraadt 2828: {
1.25 markus 2829: int sock;
2830: struct sockaddr_un addr;
2831:
1.147 stevesk 2832: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2833: if (sock < 0)
2834: error("socket: %.100s", strerror(errno));
2835: memset(&addr, 0, sizeof(addr));
2836: addr.sun_family = AF_UNIX;
2837: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2838: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2839: return sock;
2840: close(sock);
1.25 markus 2841: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2842: return -1;
1.1 deraadt 2843: }
2844:
1.51 markus 2845: int
2846: x11_connect_display(void)
1.1 deraadt 2847: {
1.162 stevesk 2848: int display_number, sock = 0;
1.25 markus 2849: const char *display;
1.51 markus 2850: char buf[1024], *cp;
1.35 markus 2851: struct addrinfo hints, *ai, *aitop;
2852: char strport[NI_MAXSERV];
2853: int gaierr;
1.25 markus 2854:
2855: /* Try to open a socket for the local X server. */
2856: display = getenv("DISPLAY");
2857: if (!display) {
2858: error("DISPLAY not set.");
1.51 markus 2859: return -1;
1.25 markus 2860: }
1.27 markus 2861: /*
2862: * Now we decode the value of the DISPLAY variable and make a
2863: * connection to the real X server.
2864: */
2865:
2866: /*
2867: * Check if it is a unix domain socket. Unix domain displays are in
2868: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2869: */
1.25 markus 2870: if (strncmp(display, "unix:", 5) == 0 ||
2871: display[0] == ':') {
2872: /* Connect to the unix domain socket. */
2873: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2874: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2875: display);
1.51 markus 2876: return -1;
1.25 markus 2877: }
2878: /* Create a socket. */
2879: sock = connect_local_xsocket(display_number);
2880: if (sock < 0)
1.51 markus 2881: return -1;
1.25 markus 2882:
2883: /* OK, we now have a connection to the display. */
1.51 markus 2884: return sock;
1.25 markus 2885: }
1.27 markus 2886: /*
2887: * Connect to an inet socket. The DISPLAY value is supposedly
2888: * hostname:d[.s], where hostname may also be numeric IP address.
2889: */
1.145 stevesk 2890: strlcpy(buf, display, sizeof(buf));
1.25 markus 2891: cp = strchr(buf, ':');
2892: if (!cp) {
2893: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2894: return -1;
1.25 markus 2895: }
2896: *cp = 0;
1.27 markus 2897: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2898: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2899: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2900: display);
1.51 markus 2901: return -1;
1.25 markus 2902: }
1.35 markus 2903:
2904: /* Look up the host address */
2905: memset(&hints, 0, sizeof(hints));
2906: hints.ai_family = IPv4or6;
2907: hints.ai_socktype = SOCK_STREAM;
2908: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2909: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2910: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2911: return -1;
1.25 markus 2912: }
1.35 markus 2913: for (ai = aitop; ai; ai = ai->ai_next) {
2914: /* Create a socket. */
1.189 markus 2915: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2916: if (sock < 0) {
1.194 markus 2917: debug2("socket: %.100s", strerror(errno));
1.41 markus 2918: continue;
2919: }
2920: /* Connect it to the display. */
2921: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2922: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2923: 6000 + display_number, strerror(errno));
2924: close(sock);
2925: continue;
2926: }
2927: /* Success */
2928: break;
1.35 markus 2929: }
2930: freeaddrinfo(aitop);
2931: if (!ai) {
1.49 markus 2932: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2933: strerror(errno));
1.51 markus 2934: return -1;
1.25 markus 2935: }
1.162 stevesk 2936: set_nodelay(sock);
1.51 markus 2937: return sock;
2938: }
2939:
2940: /*
2941: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2942: * the remote channel number. We should do whatever we want, and respond
2943: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2944: */
2945:
2946: void
1.154 markus 2947: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2948: {
1.113 markus 2949: Channel *c = NULL;
2950: int remote_id, sock = 0;
1.51 markus 2951: char *remote_host;
1.25 markus 2952:
1.113 markus 2953: debug("Received X11 open request.");
1.51 markus 2954:
1.113 markus 2955: remote_id = packet_get_int();
1.121 markus 2956:
2957: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2958: remote_host = packet_get_string(NULL);
1.51 markus 2959: } else {
2960: remote_host = xstrdup("unknown (remote did not supply name)");
2961: }
1.152 markus 2962: packet_check_eom();
1.25 markus 2963:
1.51 markus 2964: /* Obtain a connection to the real X display. */
2965: sock = x11_connect_display();
1.113 markus 2966: if (sock != -1) {
2967: /* Allocate a channel for this connection. */
2968: c = channel_new("connected x11 socket",
2969: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2970: remote_host, 1);
1.167 markus 2971: c->remote_id = remote_id;
2972: c->force_drain = 1;
1.113 markus 2973: }
1.190 markus 2974: xfree(remote_host);
1.113 markus 2975: if (c == NULL) {
1.51 markus 2976: /* Send refusal to the remote host. */
2977: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2978: packet_put_int(remote_id);
1.51 markus 2979: } else {
2980: /* Send a confirmation to the remote host. */
2981: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2982: packet_put_int(remote_id);
2983: packet_put_int(c->self);
1.51 markus 2984: }
1.113 markus 2985: packet_send();
1.72 markus 2986: }
2987:
2988: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2989: void
1.154 markus 2990: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2991: {
2992: int rchan = packet_get_int();
1.180 deraadt 2993:
1.143 deraadt 2994: switch (type) {
1.72 markus 2995: case SSH_SMSG_AGENT_OPEN:
2996: error("Warning: ssh server tried agent forwarding.");
2997: break;
2998: case SSH_SMSG_X11_OPEN:
2999: error("Warning: ssh server tried X11 forwarding.");
3000: break;
3001: default:
1.154 markus 3002: error("deny_input_open: type %d", type);
1.72 markus 3003: break;
3004: }
1.230 stevesk 3005: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3006: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3007: packet_put_int(rchan);
3008: packet_send();
1.1 deraadt 3009: }
3010:
1.27 markus 3011: /*
3012: * Requests forwarding of X11 connections, generates fake authentication
3013: * data, and enables authentication spoofing.
1.121 markus 3014: * This should be called in the client only.
1.27 markus 3015: */
1.49 markus 3016: void
1.215 djm 3017: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3018: const char *proto, const char *data)
1.1 deraadt 3019: {
1.77 markus 3020: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3021: u_int i, value;
1.25 markus 3022: char *new_data;
3023: int screen_number;
3024: const char *cp;
1.207 avsm 3025: u_int32_t rnd = 0;
1.25 markus 3026:
1.220 markus 3027: if (x11_saved_display == NULL)
3028: x11_saved_display = xstrdup(disp);
3029: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3030: error("x11_request_forwarding_with_spoofing: different "
3031: "$DISPLAY already forwarded");
3032: return;
3033: }
3034:
1.215 djm 3035: cp = disp;
3036: if (disp)
3037: cp = strchr(disp, ':');
1.25 markus 3038: if (cp)
3039: cp = strchr(cp, '.');
3040: if (cp)
3041: screen_number = atoi(cp + 1);
3042: else
3043: screen_number = 0;
3044:
1.219 djm 3045: if (x11_saved_proto == NULL) {
3046: /* Save protocol name. */
3047: x11_saved_proto = xstrdup(proto);
3048: /*
1.221 djm 3049: * Extract real authentication data and generate fake data
1.219 djm 3050: * of the same length.
3051: */
3052: x11_saved_data = xmalloc(data_len);
3053: x11_fake_data = xmalloc(data_len);
3054: for (i = 0; i < data_len; i++) {
3055: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3056: fatal("x11_request_forwarding: bad "
3057: "authentication data: %.100s", data);
3058: if (i % 4 == 0)
3059: rnd = arc4random();
3060: x11_saved_data[i] = value;
3061: x11_fake_data[i] = rnd & 0xff;
3062: rnd >>= 8;
3063: }
3064: x11_saved_data_len = data_len;
3065: x11_fake_data_len = data_len;
1.25 markus 3066: }
3067:
3068: /* Convert the fake data into hex. */
1.219 djm 3069: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3070:
3071: /* Send the request packet. */
1.51 markus 3072: if (compat20) {
3073: channel_request_start(client_session_id, "x11-req", 0);
3074: packet_put_char(0); /* XXX bool single connection */
3075: } else {
3076: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3077: }
3078: packet_put_cstring(proto);
3079: packet_put_cstring(new_data);
1.25 markus 3080: packet_put_int(screen_number);
3081: packet_send();
3082: packet_write_wait();
3083: xfree(new_data);
1.1 deraadt 3084: }
3085:
1.121 markus 3086:
3087: /* -- agent forwarding */
3088:
1.1 deraadt 3089: /* Sends a message to the server to request authentication fd forwarding. */
3090:
1.49 markus 3091: void
1.142 itojun 3092: auth_request_forwarding(void)
1.1 deraadt 3093: {
1.25 markus 3094: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3095: packet_send();
3096: packet_write_wait();
1.1 deraadt 3097: }
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