Annotation of src/usr.bin/ssh/channels.c, Revision 1.210.2.3
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"
1.210.2.3! brad 42: RCSID("$OpenBSD: channels.c,v 1.223 2005/07/17 07:17:54 djm 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:
1.210.2.2 brad 61: #define CHAN_RBUF 16*1024
62:
1.27 markus 63: /*
64: * Pointer to an array containing all allocated channels. The array is
65: * dynamically extended as needed.
66: */
1.113 markus 67: static Channel **channels = NULL;
1.1 deraadt 68:
1.27 markus 69: /*
70: * Size of the channel array. All slots of the array must always be
1.113 markus 71: * initialized (at least the type field); unused slots set to NULL
1.27 markus 72: */
1.209 avsm 73: static u_int channels_alloc = 0;
1.1 deraadt 74:
1.27 markus 75: /*
76: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 77: * updated in channel_new.
1.27 markus 78: */
1.84 markus 79: static int channel_max_fd = 0;
1.1 deraadt 80:
81:
1.121 markus 82: /* -- tcp forwarding */
1.1 deraadt 83:
1.27 markus 84: /*
85: * Data structure for storing which hosts are permitted for forward requests.
86: * The local sides of any remote forwards are stored in this array to prevent
87: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
88: * network (which might be behind a firewall).
89: */
1.25 markus 90: typedef struct {
1.41 markus 91: char *host_to_connect; /* Connect to 'host'. */
92: u_short port_to_connect; /* Connect to 'port'. */
93: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 94: } ForwardPermission;
95:
96: /* List of all permitted host/port pairs to connect. */
97: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 98:
1.1 deraadt 99: /* Number of permitted host/port pairs in the array. */
100: static int num_permitted_opens = 0;
1.27 markus 101: /*
102: * If this is true, all opens are permitted. This is the case on the server
103: * on which we have to trust the client anyway, and the user could do
104: * anything after logging in anyway.
105: */
1.1 deraadt 106: static int all_opens_permitted = 0;
107:
1.121 markus 108:
109: /* -- X11 forwarding */
110:
111: /* Maximum number of fake X11 displays to try. */
112: #define MAX_DISPLAYS 1000
113:
1.210.2.3! brad 114: /* Saved X11 local (client) display. */
! 115: static char *x11_saved_display = NULL;
! 116:
1.121 markus 117: /* Saved X11 authentication protocol name. */
118: static char *x11_saved_proto = NULL;
119:
120: /* Saved X11 authentication data. This is the real data. */
121: static char *x11_saved_data = NULL;
122: static u_int x11_saved_data_len = 0;
123:
124: /*
125: * Fake X11 authentication data. This is what the server will be sending us;
126: * we should replace any occurrences of this by the real data.
127: */
128: static char *x11_fake_data = NULL;
129: static u_int x11_fake_data_len;
130:
131:
132: /* -- agent forwarding */
133:
134: #define NUM_SOCKS 10
135:
1.82 markus 136: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 137: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 138:
1.121 markus 139: /* helper */
1.127 itojun 140: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 141:
1.121 markus 142: /* -- channel core */
1.41 markus 143:
144: Channel *
145: channel_lookup(int id)
146: {
147: Channel *c;
1.113 markus 148:
1.209 avsm 149: if (id < 0 || (u_int)id >= channels_alloc) {
1.188 itojun 150: logit("channel_lookup: %d: bad id", id);
1.41 markus 151: return NULL;
152: }
1.113 markus 153: c = channels[id];
154: if (c == NULL) {
1.188 itojun 155: logit("channel_lookup: %d: bad id: channel free", id);
1.41 markus 156: return NULL;
157: }
158: return c;
1.55 markus 159: }
160:
1.27 markus 161: /*
1.55 markus 162: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 163: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 164: */
1.1 deraadt 165:
1.127 itojun 166: static void
1.71 markus 167: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
168: int extusage, int nonblock)
1.1 deraadt 169: {
1.25 markus 170: /* Update the maximum file descriptor value. */
1.84 markus 171: channel_max_fd = MAX(channel_max_fd, rfd);
172: channel_max_fd = MAX(channel_max_fd, wfd);
173: channel_max_fd = MAX(channel_max_fd, efd);
174:
1.27 markus 175: /* XXX set close-on-exec -markus */
1.55 markus 176:
1.52 markus 177: c->rfd = rfd;
178: c->wfd = wfd;
179: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 180: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 181: c->efd = efd;
182: c->extended_usage = extusage;
1.71 markus 183:
1.91 markus 184: /* XXX ugly hack: nonblock is only set by the server */
185: if (nonblock && isatty(c->rfd)) {
1.194 markus 186: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 187: c->isatty = 1;
188: if (!isatty(c->wfd)) {
1.94 markus 189: error("channel %d: wfd %d is not a tty?",
1.91 markus 190: c->self, c->wfd);
191: }
192: } else {
193: c->isatty = 0;
194: }
195:
1.71 markus 196: /* enable nonblocking mode */
197: if (nonblock) {
198: if (rfd != -1)
199: set_nonblock(rfd);
200: if (wfd != -1)
201: set_nonblock(wfd);
202: if (efd != -1)
203: set_nonblock(efd);
204: }
1.52 markus 205: }
206:
207: /*
208: * Allocate a new channel object and set its type and socket. This will cause
209: * remote_name to be freed.
210: */
211:
1.113 markus 212: Channel *
1.52 markus 213: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 214: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 215: {
1.209 avsm 216: int found;
217: u_int i;
1.52 markus 218: Channel *c;
1.25 markus 219:
220: /* Do initial allocation if this is the first call. */
221: if (channels_alloc == 0) {
222: channels_alloc = 10;
1.113 markus 223: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 224: for (i = 0; i < channels_alloc; i++)
1.113 markus 225: channels[i] = NULL;
1.25 markus 226: }
227: /* Try to find a free slot where to put the new channel. */
228: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 229: if (channels[i] == NULL) {
1.25 markus 230: /* Found a free slot. */
1.209 avsm 231: found = (int)i;
1.25 markus 232: break;
233: }
1.209 avsm 234: if (found < 0) {
1.27 markus 235: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 236: found = channels_alloc;
1.179 markus 237: if (channels_alloc > 10000)
238: fatal("channel_new: internal error: channels_alloc %d "
239: "too big.", channels_alloc);
1.195 markus 240: channels = xrealloc(channels,
241: (channels_alloc + 10) * sizeof(Channel *));
242: channels_alloc += 10;
1.70 markus 243: debug2("channel: expanding %d", channels_alloc);
1.25 markus 244: for (i = found; i < channels_alloc; i++)
1.113 markus 245: channels[i] = NULL;
1.25 markus 246: }
1.113 markus 247: /* Initialize and return new channel. */
248: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 249: memset(c, 0, sizeof(Channel));
1.25 markus 250: buffer_init(&c->input);
251: buffer_init(&c->output);
1.41 markus 252: buffer_init(&c->extended);
1.159 markus 253: c->ostate = CHAN_OUTPUT_OPEN;
254: c->istate = CHAN_INPUT_OPEN;
255: c->flags = 0;
1.71 markus 256: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 257: c->self = found;
258: c->type = type;
1.41 markus 259: c->ctype = ctype;
1.51 markus 260: c->local_window = window;
261: c->local_window_max = window;
262: c->local_consumed = 0;
263: c->local_maxpacket = maxpack;
1.25 markus 264: c->remote_id = -1;
1.190 markus 265: c->remote_name = xstrdup(remote_name);
1.41 markus 266: c->remote_window = 0;
267: c->remote_maxpacket = 0;
1.133 markus 268: c->force_drain = 0;
1.149 markus 269: c->single_connection = 0;
1.131 markus 270: c->detach_user = NULL;
1.165 markus 271: c->confirm = NULL;
1.204 djm 272: c->confirm_ctx = NULL;
1.65 markus 273: c->input_filter = NULL;
1.25 markus 274: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 275: return c;
1.1 deraadt 276: }
1.52 markus 277:
1.132 markus 278: static int
279: channel_find_maxfd(void)
280: {
1.209 avsm 281: u_int i;
282: int max = 0;
1.132 markus 283: Channel *c;
284:
285: for (i = 0; i < channels_alloc; i++) {
286: c = channels[i];
287: if (c != NULL) {
288: max = MAX(max, c->rfd);
289: max = MAX(max, c->wfd);
290: max = MAX(max, c->efd);
291: }
292: }
293: return max;
294: }
295:
296: int
297: channel_close_fd(int *fdp)
298: {
299: int ret = 0, fd = *fdp;
300:
301: if (fd != -1) {
302: ret = close(fd);
303: *fdp = -1;
304: if (fd == channel_max_fd)
305: channel_max_fd = channel_find_maxfd();
306: }
307: return ret;
308: }
309:
1.52 markus 310: /* Close all channel fd/socket. */
311:
1.127 itojun 312: static void
1.52 markus 313: channel_close_fds(Channel *c)
314: {
1.204 djm 315: debug3("channel %d: close_fds r %d w %d e %d c %d",
316: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 317:
1.132 markus 318: channel_close_fd(&c->sock);
1.204 djm 319: channel_close_fd(&c->ctl_fd);
1.132 markus 320: channel_close_fd(&c->rfd);
321: channel_close_fd(&c->wfd);
322: channel_close_fd(&c->efd);
1.121 markus 323: }
324:
325: /* Free the channel and close its fd/socket. */
326:
327: void
328: channel_free(Channel *c)
329: {
330: char *s;
1.209 avsm 331: u_int i, n;
1.121 markus 332:
333: for (n = 0, i = 0; i < channels_alloc; i++)
334: if (channels[i])
335: n++;
1.209 avsm 336: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 337: c->remote_name ? c->remote_name : "???", n);
338:
339: s = channel_open_message();
1.194 markus 340: debug3("channel %d: status: %s", c->self, s);
1.121 markus 341: xfree(s);
342:
343: if (c->sock != -1)
344: shutdown(c->sock, SHUT_RDWR);
1.204 djm 345: if (c->ctl_fd != -1)
346: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 347: channel_close_fds(c);
348: buffer_free(&c->input);
349: buffer_free(&c->output);
350: buffer_free(&c->extended);
351: if (c->remote_name) {
352: xfree(c->remote_name);
353: c->remote_name = NULL;
354: }
355: channels[c->self] = NULL;
356: xfree(c);
357: }
358:
359: void
1.126 markus 360: channel_free_all(void)
1.121 markus 361: {
1.209 avsm 362: u_int i;
1.121 markus 363:
1.126 markus 364: for (i = 0; i < channels_alloc; i++)
365: if (channels[i] != NULL)
366: channel_free(channels[i]);
1.131 markus 367: }
368:
1.121 markus 369: /*
370: * Closes the sockets/fds of all channels. This is used to close extra file
371: * descriptors after a fork.
372: */
373:
374: void
1.142 itojun 375: channel_close_all(void)
1.121 markus 376: {
1.209 avsm 377: u_int i;
1.121 markus 378:
379: for (i = 0; i < channels_alloc; i++)
380: if (channels[i] != NULL)
381: channel_close_fds(channels[i]);
382: }
383:
384: /*
1.131 markus 385: * Stop listening to channels.
386: */
387:
388: void
389: channel_stop_listening(void)
390: {
1.209 avsm 391: u_int i;
1.131 markus 392: Channel *c;
393:
394: for (i = 0; i < channels_alloc; i++) {
395: c = channels[i];
396: if (c != NULL) {
397: switch (c->type) {
398: case SSH_CHANNEL_AUTH_SOCKET:
399: case SSH_CHANNEL_PORT_LISTENER:
400: case SSH_CHANNEL_RPORT_LISTENER:
401: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 402: channel_close_fd(&c->sock);
1.131 markus 403: channel_free(c);
404: break;
405: }
406: }
407: }
408: }
409:
410: /*
1.121 markus 411: * Returns true if no channel has too much buffered data, and false if one or
412: * more channel is overfull.
413: */
414:
415: int
1.142 itojun 416: channel_not_very_much_buffered_data(void)
1.121 markus 417: {
418: u_int i;
419: Channel *c;
420:
421: for (i = 0; i < channels_alloc; i++) {
422: c = channels[i];
423: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 424: #if 0
425: if (!compat20 &&
426: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 427: debug2("channel %d: big input buffer %d",
1.121 markus 428: c->self, buffer_len(&c->input));
429: return 0;
430: }
1.136 markus 431: #endif
1.121 markus 432: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 433: debug2("channel %d: big output buffer %u > %u",
1.136 markus 434: c->self, buffer_len(&c->output),
435: packet_get_maxsize());
1.121 markus 436: return 0;
437: }
438: }
439: }
440: return 1;
441: }
442:
443: /* Returns true if any channel is still open. */
444:
445: int
1.142 itojun 446: channel_still_open(void)
1.121 markus 447: {
1.209 avsm 448: u_int i;
1.121 markus 449: Channel *c;
450:
451: for (i = 0; i < channels_alloc; i++) {
452: c = channels[i];
453: if (c == NULL)
454: continue;
455: switch (c->type) {
456: case SSH_CHANNEL_X11_LISTENER:
457: case SSH_CHANNEL_PORT_LISTENER:
458: case SSH_CHANNEL_RPORT_LISTENER:
459: case SSH_CHANNEL_CLOSED:
460: case SSH_CHANNEL_AUTH_SOCKET:
461: case SSH_CHANNEL_DYNAMIC:
462: case SSH_CHANNEL_CONNECTING:
463: case SSH_CHANNEL_ZOMBIE:
464: continue;
465: case SSH_CHANNEL_LARVAL:
466: if (!compat20)
467: fatal("cannot happen: SSH_CHANNEL_LARVAL");
468: continue;
469: case SSH_CHANNEL_OPENING:
470: case SSH_CHANNEL_OPEN:
471: case SSH_CHANNEL_X11_OPEN:
472: return 1;
473: case SSH_CHANNEL_INPUT_DRAINING:
474: case SSH_CHANNEL_OUTPUT_DRAINING:
475: if (!compat13)
476: fatal("cannot happen: OUT_DRAIN");
477: return 1;
478: default:
479: fatal("channel_still_open: bad channel type %d", c->type);
480: /* NOTREACHED */
481: }
482: }
483: return 0;
484: }
485:
486: /* Returns the id of an open channel suitable for keepaliving */
487:
488: int
1.142 itojun 489: channel_find_open(void)
1.121 markus 490: {
1.209 avsm 491: u_int i;
1.121 markus 492: Channel *c;
493:
494: for (i = 0; i < channels_alloc; i++) {
495: c = channels[i];
1.206 djm 496: if (c == NULL || c->remote_id < 0)
1.121 markus 497: continue;
498: switch (c->type) {
499: case SSH_CHANNEL_CLOSED:
500: case SSH_CHANNEL_DYNAMIC:
501: case SSH_CHANNEL_X11_LISTENER:
502: case SSH_CHANNEL_PORT_LISTENER:
503: case SSH_CHANNEL_RPORT_LISTENER:
504: case SSH_CHANNEL_OPENING:
505: case SSH_CHANNEL_CONNECTING:
506: case SSH_CHANNEL_ZOMBIE:
507: continue;
508: case SSH_CHANNEL_LARVAL:
509: case SSH_CHANNEL_AUTH_SOCKET:
510: case SSH_CHANNEL_OPEN:
511: case SSH_CHANNEL_X11_OPEN:
512: return i;
513: case SSH_CHANNEL_INPUT_DRAINING:
514: case SSH_CHANNEL_OUTPUT_DRAINING:
515: if (!compat13)
516: fatal("cannot happen: OUT_DRAIN");
517: return i;
518: default:
519: fatal("channel_find_open: bad channel type %d", c->type);
520: /* NOTREACHED */
521: }
522: }
523: return -1;
524: }
525:
526:
527: /*
528: * Returns a message describing the currently open forwarded connections,
529: * suitable for sending to the client. The message contains crlf pairs for
530: * newlines.
531: */
532:
533: char *
1.142 itojun 534: channel_open_message(void)
1.121 markus 535: {
536: Buffer buffer;
537: Channel *c;
538: char buf[1024], *cp;
1.209 avsm 539: u_int i;
1.121 markus 540:
541: buffer_init(&buffer);
542: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
543: buffer_append(&buffer, buf, strlen(buf));
544: for (i = 0; i < channels_alloc; i++) {
545: c = channels[i];
546: if (c == NULL)
547: continue;
548: switch (c->type) {
549: case SSH_CHANNEL_X11_LISTENER:
550: case SSH_CHANNEL_PORT_LISTENER:
551: case SSH_CHANNEL_RPORT_LISTENER:
552: case SSH_CHANNEL_CLOSED:
553: case SSH_CHANNEL_AUTH_SOCKET:
554: case SSH_CHANNEL_ZOMBIE:
555: continue;
556: case SSH_CHANNEL_LARVAL:
557: case SSH_CHANNEL_OPENING:
558: case SSH_CHANNEL_CONNECTING:
559: case SSH_CHANNEL_DYNAMIC:
560: case SSH_CHANNEL_OPEN:
561: case SSH_CHANNEL_X11_OPEN:
562: case SSH_CHANNEL_INPUT_DRAINING:
563: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 564: snprintf(buf, sizeof buf,
565: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 566: c->self, c->remote_name,
567: c->type, c->remote_id,
568: c->istate, buffer_len(&c->input),
569: c->ostate, buffer_len(&c->output),
1.204 djm 570: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 571: buffer_append(&buffer, buf, strlen(buf));
572: continue;
573: default:
574: fatal("channel_open_message: bad channel type %d", c->type);
575: /* NOTREACHED */
576: }
577: }
578: buffer_append(&buffer, "\0", 1);
579: cp = xstrdup(buffer_ptr(&buffer));
580: buffer_free(&buffer);
581: return cp;
582: }
583:
584: void
585: channel_send_open(int id)
586: {
587: Channel *c = channel_lookup(id);
1.180 deraadt 588:
1.121 markus 589: if (c == NULL) {
1.188 itojun 590: logit("channel_send_open: %d: bad id", id);
1.121 markus 591: return;
592: }
1.184 markus 593: debug2("channel %d: send open", id);
1.121 markus 594: packet_start(SSH2_MSG_CHANNEL_OPEN);
595: packet_put_cstring(c->ctype);
596: packet_put_int(c->self);
597: packet_put_int(c->local_window);
598: packet_put_int(c->local_maxpacket);
599: packet_send();
600: }
601:
602: void
1.184 markus 603: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 604: {
1.184 markus 605: Channel *c = channel_lookup(id);
1.180 deraadt 606:
1.121 markus 607: if (c == NULL) {
1.188 itojun 608: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 609: return;
610: }
1.204 djm 611: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 612: packet_start(SSH2_MSG_CHANNEL_REQUEST);
613: packet_put_int(c->remote_id);
614: packet_put_cstring(service);
615: packet_put_char(wantconfirm);
616: }
617: void
1.204 djm 618: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 619: {
620: Channel *c = channel_lookup(id);
1.180 deraadt 621:
1.121 markus 622: if (c == NULL) {
1.188 itojun 623: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 624: return;
625: }
1.165 markus 626: c->confirm = fn;
1.204 djm 627: c->confirm_ctx = ctx;
1.121 markus 628: }
629: void
630: channel_register_cleanup(int id, channel_callback_fn *fn)
631: {
632: Channel *c = channel_lookup(id);
1.180 deraadt 633:
1.121 markus 634: if (c == NULL) {
1.188 itojun 635: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 636: return;
637: }
1.131 markus 638: c->detach_user = fn;
1.121 markus 639: }
640: void
641: channel_cancel_cleanup(int id)
642: {
643: Channel *c = channel_lookup(id);
1.180 deraadt 644:
1.121 markus 645: if (c == NULL) {
1.188 itojun 646: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 647: return;
1.52 markus 648: }
1.131 markus 649: c->detach_user = NULL;
1.121 markus 650: }
651: void
652: channel_register_filter(int id, channel_filter_fn *fn)
653: {
654: Channel *c = channel_lookup(id);
1.180 deraadt 655:
1.121 markus 656: if (c == NULL) {
1.188 itojun 657: logit("channel_register_filter: %d: bad id", id);
1.121 markus 658: return;
1.52 markus 659: }
1.121 markus 660: c->input_filter = fn;
1.52 markus 661: }
662:
1.49 markus 663: void
1.121 markus 664: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 665: int extusage, int nonblock, u_int window_max)
1.1 deraadt 666: {
1.121 markus 667: Channel *c = channel_lookup(id);
1.180 deraadt 668:
1.121 markus 669: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
670: fatal("channel_activate for non-larval channel %d.", id);
671: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
672: c->type = SSH_CHANNEL_OPEN;
1.168 markus 673: c->local_window = c->local_window_max = window_max;
1.121 markus 674: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
675: packet_put_int(c->remote_id);
676: packet_put_int(c->local_window);
677: packet_send();
1.1 deraadt 678: }
679:
1.27 markus 680: /*
1.41 markus 681: * 'channel_pre*' are called just before select() to add any bits relevant to
682: * channels in the select bitmasks.
683: */
684: /*
685: * 'channel_post*': perform any appropriate operations for channels which
686: * have events pending.
1.27 markus 687: */
1.41 markus 688: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
689: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
690: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
691:
1.127 itojun 692: static void
1.41 markus 693: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
694: {
695: FD_SET(c->sock, readset);
696: }
697:
1.127 itojun 698: static void
1.75 markus 699: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
700: {
701: debug3("channel %d: waiting for connection", c->self);
702: FD_SET(c->sock, writeset);
703: }
704:
1.127 itojun 705: static void
1.41 markus 706: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
707: {
708: if (buffer_len(&c->input) < packet_get_maxsize())
709: FD_SET(c->sock, readset);
710: if (buffer_len(&c->output) > 0)
711: FD_SET(c->sock, writeset);
712: }
1.1 deraadt 713:
1.127 itojun 714: static void
1.157 markus 715: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 716: {
1.157 markus 717: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 718:
1.210.2.2 brad 719: /* check buffer limits */
720: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
721:
1.44 markus 722: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 723: limit > 0 &&
724: buffer_len(&c->input) < limit)
1.44 markus 725: FD_SET(c->rfd, readset);
726: if (c->ostate == CHAN_OUTPUT_OPEN ||
727: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
728: if (buffer_len(&c->output) > 0) {
729: FD_SET(c->wfd, writeset);
730: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 731: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.210.2.3! brad 732: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
! 733: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 734: else
735: chan_obuf_empty(c);
1.44 markus 736: }
737: }
738: /** XXX check close conditions, too */
1.157 markus 739: if (compat20 && c->efd != -1) {
1.44 markus 740: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
741: buffer_len(&c->extended) > 0)
742: FD_SET(c->efd, writeset);
1.172 markus 743: else if (!(c->flags & CHAN_EOF_SENT) &&
744: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 745: buffer_len(&c->extended) < c->remote_window)
746: FD_SET(c->efd, readset);
747: }
1.204 djm 748: /* XXX: What about efd? races? */
1.208 deraadt 749: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 750: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
751: FD_SET(c->ctl_fd, readset);
1.44 markus 752: }
753:
1.127 itojun 754: static void
1.41 markus 755: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
756: {
757: if (buffer_len(&c->input) == 0) {
758: packet_start(SSH_MSG_CHANNEL_CLOSE);
759: packet_put_int(c->remote_id);
760: packet_send();
761: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 762: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 763: }
764: }
765:
1.127 itojun 766: static void
1.41 markus 767: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
768: {
769: if (buffer_len(&c->output) == 0)
1.113 markus 770: chan_mark_dead(c);
1.49 markus 771: else
1.41 markus 772: FD_SET(c->sock, writeset);
773: }
774:
775: /*
776: * This is a special state for X11 authentication spoofing. An opened X11
777: * connection (when authentication spoofing is being done) remains in this
778: * state until the first packet has been completely read. The authentication
779: * data in that packet is then substituted by the real data if it matches the
780: * fake data, and the channel is put into normal mode.
1.51 markus 781: * XXX All this happens at the client side.
1.121 markus 782: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 783: */
1.127 itojun 784: static int
1.121 markus 785: x11_open_helper(Buffer *b)
1.1 deraadt 786: {
1.77 markus 787: u_char *ucp;
788: u_int proto_len, data_len;
1.25 markus 789:
1.41 markus 790: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 791: if (buffer_len(b) < 12)
1.41 markus 792: return 0;
793:
794: /* Parse the lengths of variable-length fields. */
1.155 stevesk 795: ucp = buffer_ptr(b);
1.41 markus 796: if (ucp[0] == 0x42) { /* Byte order MSB first. */
797: proto_len = 256 * ucp[6] + ucp[7];
798: data_len = 256 * ucp[8] + ucp[9];
799: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
800: proto_len = ucp[6] + 256 * ucp[7];
801: data_len = ucp[8] + 256 * ucp[9];
802: } else {
1.194 markus 803: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 804: ucp[0]);
1.41 markus 805: return -1;
806: }
807:
808: /* Check if the whole packet is in buffer. */
1.121 markus 809: if (buffer_len(b) <
1.41 markus 810: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
811: return 0;
812:
813: /* Check if authentication protocol matches. */
814: if (proto_len != strlen(x11_saved_proto) ||
815: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 816: debug2("X11 connection uses different authentication protocol.");
1.41 markus 817: return -1;
818: }
819: /* Check if authentication data matches our fake data. */
820: if (data_len != x11_fake_data_len ||
821: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
822: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 823: debug2("X11 auth data does not match fake data.");
1.41 markus 824: return -1;
825: }
826: /* Check fake data length */
827: if (x11_fake_data_len != x11_saved_data_len) {
828: error("X11 fake_data_len %d != saved_data_len %d",
829: x11_fake_data_len, x11_saved_data_len);
830: return -1;
831: }
832: /*
833: * Received authentication protocol and data match
834: * our fake data. Substitute the fake data with real
835: * data.
836: */
837: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
838: x11_saved_data, x11_saved_data_len);
839: return 1;
840: }
841:
1.127 itojun 842: static void
1.41 markus 843: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
844: {
1.121 markus 845: int ret = x11_open_helper(&c->output);
1.180 deraadt 846:
1.41 markus 847: if (ret == 1) {
848: /* Start normal processing for the channel. */
849: c->type = SSH_CHANNEL_OPEN;
1.47 markus 850: channel_pre_open_13(c, readset, writeset);
1.41 markus 851: } else if (ret == -1) {
852: /*
853: * We have received an X11 connection that has bad
854: * authentication information.
855: */
1.188 itojun 856: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 857: buffer_clear(&c->input);
858: buffer_clear(&c->output);
1.132 markus 859: channel_close_fd(&c->sock);
1.41 markus 860: c->sock = -1;
861: c->type = SSH_CHANNEL_CLOSED;
862: packet_start(SSH_MSG_CHANNEL_CLOSE);
863: packet_put_int(c->remote_id);
864: packet_send();
865: }
866: }
1.25 markus 867:
1.127 itojun 868: static void
1.51 markus 869: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 870: {
1.121 markus 871: int ret = x11_open_helper(&c->output);
1.133 markus 872:
873: /* c->force_drain = 1; */
874:
1.41 markus 875: if (ret == 1) {
876: c->type = SSH_CHANNEL_OPEN;
1.157 markus 877: channel_pre_open(c, readset, writeset);
1.41 markus 878: } else if (ret == -1) {
1.188 itojun 879: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 880: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 881: chan_read_failed(c);
882: buffer_clear(&c->input);
883: chan_ibuf_empty(c);
884: buffer_clear(&c->output);
885: /* for proto v1, the peer will send an IEOF */
886: if (compat20)
887: chan_write_failed(c);
888: else
889: c->type = SSH_CHANNEL_OPEN;
1.194 markus 890: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 891: }
892: }
1.25 markus 893:
1.104 markus 894: /* try to decode a socks4 header */
1.127 itojun 895: static int
1.104 markus 896: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 897: {
1.181 markus 898: char *p, *host;
1.210.2.3! brad 899: u_int len, have, i, found;
1.148 deraadt 900: char username[256];
1.103 markus 901: struct {
902: u_int8_t version;
903: u_int8_t command;
904: u_int16_t dest_port;
1.104 markus 905: struct in_addr dest_addr;
1.103 markus 906: } s4_req, s4_rsp;
907:
1.104 markus 908: debug2("channel %d: decode socks4", c->self);
1.109 markus 909:
910: have = buffer_len(&c->input);
911: len = sizeof(s4_req);
912: if (have < len)
913: return 0;
914: p = buffer_ptr(&c->input);
915: for (found = 0, i = len; i < have; i++) {
916: if (p[i] == '\0') {
917: found = 1;
918: break;
919: }
920: if (i > 1024) {
921: /* the peer is probably sending garbage */
922: debug("channel %d: decode socks4: too long",
923: c->self);
924: return -1;
925: }
926: }
927: if (!found)
928: return 0;
1.103 markus 929: buffer_get(&c->input, (char *)&s4_req.version, 1);
930: buffer_get(&c->input, (char *)&s4_req.command, 1);
931: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 932: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 933: have = buffer_len(&c->input);
1.103 markus 934: p = buffer_ptr(&c->input);
935: len = strlen(p);
1.106 markus 936: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 937: if (len > have)
1.104 markus 938: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 939: c->self, len, have);
940: strlcpy(username, p, sizeof(username));
941: buffer_consume(&c->input, len);
942: buffer_consume(&c->input, 1); /* trailing '\0' */
943:
1.104 markus 944: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 945: strlcpy(c->path, host, sizeof(c->path));
946: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 947:
1.194 markus 948: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 949: c->self, host, c->host_port, s4_req.command);
1.103 markus 950:
1.104 markus 951: if (s4_req.command != 1) {
952: debug("channel %d: cannot handle: socks4 cn %d",
953: c->self, s4_req.command);
954: return -1;
1.103 markus 955: }
1.104 markus 956: s4_rsp.version = 0; /* vn: 0 for reply */
957: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 958: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 959: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 960: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 961: return 1;
962: }
963:
1.193 markus 964: /* try to decode a socks5 header */
965: #define SSH_SOCKS5_AUTHDONE 0x1000
966: #define SSH_SOCKS5_NOAUTH 0x00
967: #define SSH_SOCKS5_IPV4 0x01
968: #define SSH_SOCKS5_DOMAIN 0x03
969: #define SSH_SOCKS5_IPV6 0x04
970: #define SSH_SOCKS5_CONNECT 0x01
971: #define SSH_SOCKS5_SUCCESS 0x00
972:
973: static int
974: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
975: {
976: struct {
977: u_int8_t version;
978: u_int8_t command;
979: u_int8_t reserved;
980: u_int8_t atyp;
981: } s5_req, s5_rsp;
982: u_int16_t dest_port;
983: u_char *p, dest_addr[255+1];
1.210.2.3! brad 984: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 985:
986: debug2("channel %d: decode socks5", c->self);
987: p = buffer_ptr(&c->input);
988: if (p[0] != 0x05)
989: return -1;
990: have = buffer_len(&c->input);
991: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
992: /* format: ver | nmethods | methods */
1.198 djm 993: if (have < 2)
1.193 markus 994: return 0;
995: nmethods = p[1];
996: if (have < nmethods + 2)
997: return 0;
998: /* look for method: "NO AUTHENTICATION REQUIRED" */
999: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1000: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1001: found = 1;
1002: break;
1003: }
1004: }
1005: if (!found) {
1006: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1007: c->self);
1008: return -1;
1009: }
1010: buffer_consume(&c->input, nmethods + 2);
1011: buffer_put_char(&c->output, 0x05); /* version */
1012: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1013: FD_SET(c->sock, writeset);
1014: c->flags |= SSH_SOCKS5_AUTHDONE;
1015: debug2("channel %d: socks5 auth done", c->self);
1016: return 0; /* need more */
1017: }
1018: debug2("channel %d: socks5 post auth", c->self);
1019: if (have < sizeof(s5_req)+1)
1020: return 0; /* need more */
1021: memcpy((char *)&s5_req, p, sizeof(s5_req));
1022: if (s5_req.version != 0x05 ||
1023: s5_req.command != SSH_SOCKS5_CONNECT ||
1024: s5_req.reserved != 0x00) {
1.194 markus 1025: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1026: return -1;
1027: }
1.210.2.2 brad 1028: switch (s5_req.atyp){
1.193 markus 1029: case SSH_SOCKS5_IPV4:
1030: addrlen = 4;
1031: af = AF_INET;
1032: break;
1033: case SSH_SOCKS5_DOMAIN:
1034: addrlen = p[sizeof(s5_req)];
1035: af = -1;
1036: break;
1037: case SSH_SOCKS5_IPV6:
1038: addrlen = 16;
1039: af = AF_INET6;
1040: break;
1041: default:
1.194 markus 1042: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1043: return -1;
1044: }
1045: if (have < 4 + addrlen + 2)
1046: return 0;
1047: buffer_consume(&c->input, sizeof(s5_req));
1048: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1049: buffer_consume(&c->input, 1); /* host string length */
1050: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1051: buffer_get(&c->input, (char *)&dest_port, 2);
1052: dest_addr[addrlen] = '\0';
1053: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1054: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1055: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1056: return -1;
1057: c->host_port = ntohs(dest_port);
1.198 djm 1058:
1.194 markus 1059: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1060: c->self, c->path, c->host_port, s5_req.command);
1061:
1062: s5_rsp.version = 0x05;
1063: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1064: s5_rsp.reserved = 0; /* ignored */
1065: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1066: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1067: dest_port = 0; /* ignored */
1068:
1069: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1070: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1071: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1072: return 1;
1073: }
1074:
1.104 markus 1075: /* dynamic port forwarding */
1.127 itojun 1076: static void
1.104 markus 1077: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1078: {
1079: u_char *p;
1.210.2.3! brad 1080: u_int have;
! 1081: int ret;
1.103 markus 1082:
1.104 markus 1083: have = buffer_len(&c->input);
1.137 markus 1084: c->delayed = 0;
1.104 markus 1085: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1086: /* buffer_dump(&c->input); */
1.104 markus 1087: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1088: if (have < 3) {
1.104 markus 1089: /* need more */
1090: FD_SET(c->sock, readset);
1091: return;
1092: }
1093: /* try to guess the protocol */
1094: p = buffer_ptr(&c->input);
1095: switch (p[0]) {
1096: case 0x04:
1097: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1098: break;
1099: case 0x05:
1100: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1101: break;
1102: default:
1103: ret = -1;
1104: break;
1105: }
1106: if (ret < 0) {
1.113 markus 1107: chan_mark_dead(c);
1.104 markus 1108: } else if (ret == 0) {
1109: debug2("channel %d: pre_dynamic: need more", c->self);
1110: /* need more */
1111: FD_SET(c->sock, readset);
1112: } else {
1113: /* switch to the next state */
1114: c->type = SSH_CHANNEL_OPENING;
1115: port_open_helper(c, "direct-tcpip");
1116: }
1.103 markus 1117: }
1118:
1.41 markus 1119: /* This is our fake X11 server socket. */
1.127 itojun 1120: static void
1.41 markus 1121: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1122: {
1.113 markus 1123: Channel *nc;
1.41 markus 1124: struct sockaddr addr;
1.162 stevesk 1125: int newsock;
1.41 markus 1126: socklen_t addrlen;
1.85 markus 1127: char buf[16384], *remote_ipaddr;
1.51 markus 1128: int remote_port;
1.25 markus 1129:
1.41 markus 1130: if (FD_ISSET(c->sock, readset)) {
1131: debug("X11 connection requested.");
1132: addrlen = sizeof(addr);
1133: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1134: if (c->single_connection) {
1.194 markus 1135: debug2("single_connection: closing X11 listener.");
1.149 markus 1136: channel_close_fd(&c->sock);
1137: chan_mark_dead(c);
1138: }
1.41 markus 1139: if (newsock < 0) {
1140: error("accept: %.100s", strerror(errno));
1141: return;
1142: }
1.162 stevesk 1143: set_nodelay(newsock);
1.85 markus 1144: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1145: remote_port = get_peer_port(newsock);
1.41 markus 1146: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1147: remote_ipaddr, remote_port);
1.51 markus 1148:
1.113 markus 1149: nc = channel_new("accepted x11 socket",
1.51 markus 1150: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1151: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1152: if (compat20) {
1153: packet_start(SSH2_MSG_CHANNEL_OPEN);
1154: packet_put_cstring("x11");
1.113 markus 1155: packet_put_int(nc->self);
1.149 markus 1156: packet_put_int(nc->local_window_max);
1157: packet_put_int(nc->local_maxpacket);
1.85 markus 1158: /* originator ipaddr and port */
1159: packet_put_cstring(remote_ipaddr);
1.57 markus 1160: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1161: debug2("ssh2 x11 bug compat mode");
1.57 markus 1162: } else {
1163: packet_put_int(remote_port);
1164: }
1.51 markus 1165: packet_send();
1166: } else {
1167: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1168: packet_put_int(nc->self);
1.121 markus 1169: if (packet_get_protocol_flags() &
1170: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1171: packet_put_cstring(buf);
1.51 markus 1172: packet_send();
1173: }
1.85 markus 1174: xfree(remote_ipaddr);
1.41 markus 1175: }
1176: }
1.25 markus 1177:
1.127 itojun 1178: static void
1.103 markus 1179: port_open_helper(Channel *c, char *rtype)
1180: {
1181: int direct;
1182: char buf[1024];
1183: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.210.2.3! brad 1184: int remote_port = get_peer_port(c->sock);
1.103 markus 1185:
1186: direct = (strcmp(rtype, "direct-tcpip") == 0);
1187:
1188: snprintf(buf, sizeof buf,
1189: "%s: listening port %d for %.100s port %d, "
1190: "connect from %.200s port %d",
1191: rtype, c->listening_port, c->path, c->host_port,
1192: remote_ipaddr, remote_port);
1193:
1194: xfree(c->remote_name);
1195: c->remote_name = xstrdup(buf);
1196:
1197: if (compat20) {
1198: packet_start(SSH2_MSG_CHANNEL_OPEN);
1199: packet_put_cstring(rtype);
1200: packet_put_int(c->self);
1201: packet_put_int(c->local_window_max);
1202: packet_put_int(c->local_maxpacket);
1203: if (direct) {
1204: /* target host, port */
1205: packet_put_cstring(c->path);
1206: packet_put_int(c->host_port);
1207: } else {
1208: /* listen address, port */
1209: packet_put_cstring(c->path);
1210: packet_put_int(c->listening_port);
1211: }
1212: /* originator host and port */
1213: packet_put_cstring(remote_ipaddr);
1.210.2.3! brad 1214: packet_put_int((u_int)remote_port);
1.103 markus 1215: packet_send();
1216: } else {
1217: packet_start(SSH_MSG_PORT_OPEN);
1218: packet_put_int(c->self);
1219: packet_put_cstring(c->path);
1220: packet_put_int(c->host_port);
1.121 markus 1221: if (packet_get_protocol_flags() &
1222: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1223: packet_put_cstring(c->remote_name);
1224: packet_send();
1225: }
1226: xfree(remote_ipaddr);
1227: }
1228:
1.41 markus 1229: /*
1230: * This socket is listening for connections to a forwarded TCP/IP port.
1231: */
1.127 itojun 1232: static void
1.41 markus 1233: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1234: {
1.103 markus 1235: Channel *nc;
1.41 markus 1236: struct sockaddr addr;
1.113 markus 1237: int newsock, nextstate;
1.41 markus 1238: socklen_t addrlen;
1.103 markus 1239: char *rtype;
1.73 markus 1240:
1.41 markus 1241: if (FD_ISSET(c->sock, readset)) {
1242: debug("Connection to port %d forwarding "
1243: "to %.100s port %d requested.",
1244: c->listening_port, c->path, c->host_port);
1.103 markus 1245:
1.137 markus 1246: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1247: nextstate = SSH_CHANNEL_OPENING;
1248: rtype = "forwarded-tcpip";
1249: } else {
1250: if (c->host_port == 0) {
1251: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1252: rtype = "dynamic-tcpip";
1.137 markus 1253: } else {
1254: nextstate = SSH_CHANNEL_OPENING;
1255: rtype = "direct-tcpip";
1256: }
1257: }
1.103 markus 1258:
1.41 markus 1259: addrlen = sizeof(addr);
1260: newsock = accept(c->sock, &addr, &addrlen);
1261: if (newsock < 0) {
1262: error("accept: %.100s", strerror(errno));
1263: return;
1264: }
1.169 stevesk 1265: set_nodelay(newsock);
1.190 markus 1266: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1267: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1268: nc->listening_port = c->listening_port;
1269: nc->host_port = c->host_port;
1270: strlcpy(nc->path, c->path, sizeof(nc->path));
1271:
1.137 markus 1272: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1273: /*
1274: * do not call the channel_post handler until
1275: * this flag has been reset by a pre-handler.
1276: * otherwise the FD_ISSET calls might overflow
1277: */
1278: nc->delayed = 1;
1279: } else {
1.103 markus 1280: port_open_helper(nc, rtype);
1.137 markus 1281: }
1.41 markus 1282: }
1283: }
1.25 markus 1284:
1.41 markus 1285: /*
1286: * This is the authentication agent socket listening for connections from
1287: * clients.
1288: */
1.127 itojun 1289: static void
1.41 markus 1290: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1291: {
1.113 markus 1292: Channel *nc;
1293: int newsock;
1.41 markus 1294: struct sockaddr addr;
1295: socklen_t addrlen;
1.25 markus 1296:
1.41 markus 1297: if (FD_ISSET(c->sock, readset)) {
1298: addrlen = sizeof(addr);
1299: newsock = accept(c->sock, &addr, &addrlen);
1300: if (newsock < 0) {
1301: error("accept from auth socket: %.100s", strerror(errno));
1302: return;
1303: }
1.113 markus 1304: nc = channel_new("accepted auth socket",
1.73 markus 1305: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1306: c->local_window_max, c->local_maxpacket,
1.190 markus 1307: 0, "accepted auth socket", 1);
1.73 markus 1308: if (compat20) {
1309: packet_start(SSH2_MSG_CHANNEL_OPEN);
1310: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1311: packet_put_int(nc->self);
1.73 markus 1312: packet_put_int(c->local_window_max);
1313: packet_put_int(c->local_maxpacket);
1314: } else {
1315: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1316: packet_put_int(nc->self);
1.73 markus 1317: }
1.41 markus 1318: packet_send();
1319: }
1320: }
1.25 markus 1321:
1.127 itojun 1322: static void
1.75 markus 1323: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1324: {
1.114 markus 1325: int err = 0;
1.129 stevesk 1326: socklen_t sz = sizeof(err);
1.114 markus 1327:
1.75 markus 1328: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1329: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1330: err = errno;
1331: error("getsockopt SO_ERROR failed");
1332: }
1333: if (err == 0) {
1334: debug("channel %d: connected", c->self);
1335: c->type = SSH_CHANNEL_OPEN;
1336: if (compat20) {
1337: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1338: packet_put_int(c->remote_id);
1339: packet_put_int(c->self);
1340: packet_put_int(c->local_window);
1341: packet_put_int(c->local_maxpacket);
1342: } else {
1343: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1344: packet_put_int(c->remote_id);
1345: packet_put_int(c->self);
1346: }
1.75 markus 1347: } else {
1.114 markus 1348: debug("channel %d: not connected: %s",
1349: c->self, strerror(err));
1350: if (compat20) {
1351: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1352: packet_put_int(c->remote_id);
1353: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1354: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1355: packet_put_cstring(strerror(err));
1356: packet_put_cstring("");
1357: }
1.75 markus 1358: } else {
1.114 markus 1359: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1360: packet_put_int(c->remote_id);
1.75 markus 1361: }
1.114 markus 1362: chan_mark_dead(c);
1.75 markus 1363: }
1.114 markus 1364: packet_send();
1.75 markus 1365: }
1366: }
1367:
1.127 itojun 1368: static int
1.41 markus 1369: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1370: {
1.210.2.2 brad 1371: char buf[CHAN_RBUF];
1.41 markus 1372: int len;
1.25 markus 1373:
1.118 markus 1374: if (c->rfd != -1 &&
1.41 markus 1375: FD_ISSET(c->rfd, readset)) {
1376: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1377: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1378: return 1;
1.41 markus 1379: if (len <= 0) {
1.194 markus 1380: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1381: c->self, c->rfd, len);
1.104 markus 1382: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1383: debug2("channel %d: not open", c->self);
1.113 markus 1384: chan_mark_dead(c);
1.103 markus 1385: return -1;
1.104 markus 1386: } else if (compat13) {
1.158 markus 1387: buffer_clear(&c->output);
1.41 markus 1388: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1389: debug2("channel %d: input draining.", c->self);
1.25 markus 1390: } else {
1.41 markus 1391: chan_read_failed(c);
1.25 markus 1392: }
1.41 markus 1393: return -1;
1394: }
1.143 deraadt 1395: if (c->input_filter != NULL) {
1.66 markus 1396: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1397: debug2("channel %d: filter stops", c->self);
1.65 markus 1398: chan_read_failed(c);
1399: }
1400: } else {
1401: buffer_append(&c->input, buf, len);
1402: }
1.41 markus 1403: }
1404: return 1;
1405: }
1.127 itojun 1406: static int
1.41 markus 1407: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1408: {
1.95 markus 1409: struct termios tio;
1.134 markus 1410: u_char *data;
1411: u_int dlen;
1.41 markus 1412: int len;
1.25 markus 1413:
1.41 markus 1414: /* Send buffered output data to the socket. */
1.118 markus 1415: if (c->wfd != -1 &&
1.41 markus 1416: FD_ISSET(c->wfd, writeset) &&
1417: buffer_len(&c->output) > 0) {
1.134 markus 1418: data = buffer_ptr(&c->output);
1419: dlen = buffer_len(&c->output);
1420: len = write(c->wfd, data, dlen);
1.53 markus 1421: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1422: return 1;
1.41 markus 1423: if (len <= 0) {
1.104 markus 1424: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1425: debug2("channel %d: not open", c->self);
1.113 markus 1426: chan_mark_dead(c);
1.104 markus 1427: return -1;
1428: } else if (compat13) {
1.158 markus 1429: buffer_clear(&c->output);
1.194 markus 1430: debug2("channel %d: input draining.", c->self);
1.41 markus 1431: c->type = SSH_CHANNEL_INPUT_DRAINING;
1432: } else {
1433: chan_write_failed(c);
1434: }
1435: return -1;
1.91 markus 1436: }
1.134 markus 1437: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1438: if (tcgetattr(c->wfd, &tio) == 0 &&
1439: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1440: /*
1441: * Simulate echo to reduce the impact of
1.96 markus 1442: * traffic analysis. We need to match the
1.95 markus 1443: * size of a SSH2_MSG_CHANNEL_DATA message
1444: * (4 byte channel id + data)
1.91 markus 1445: */
1.95 markus 1446: packet_send_ignore(4 + len);
1.91 markus 1447: packet_send();
1448: }
1.25 markus 1449: }
1.41 markus 1450: buffer_consume(&c->output, len);
1.44 markus 1451: if (compat20 && len > 0) {
1452: c->local_consumed += len;
1453: }
1454: }
1455: return 1;
1456: }
1.127 itojun 1457: static int
1.44 markus 1458: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1459: {
1.210.2.2 brad 1460: char buf[CHAN_RBUF];
1.44 markus 1461: int len;
1462:
1.45 markus 1463: /** XXX handle drain efd, too */
1.44 markus 1464: if (c->efd != -1) {
1465: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1466: FD_ISSET(c->efd, writeset) &&
1467: buffer_len(&c->extended) > 0) {
1468: len = write(c->efd, buffer_ptr(&c->extended),
1469: buffer_len(&c->extended));
1.70 markus 1470: debug2("channel %d: written %d to efd %d",
1.44 markus 1471: c->self, len, c->efd);
1.93 markus 1472: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1473: return 1;
1474: if (len <= 0) {
1475: debug2("channel %d: closing write-efd %d",
1476: c->self, c->efd);
1.132 markus 1477: channel_close_fd(&c->efd);
1.93 markus 1478: } else {
1.44 markus 1479: buffer_consume(&c->extended, len);
1480: c->local_consumed += len;
1481: }
1482: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1483: FD_ISSET(c->efd, readset)) {
1484: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1485: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1486: c->self, len, c->efd);
1.93 markus 1487: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1488: return 1;
1489: if (len <= 0) {
1490: debug2("channel %d: closing read-efd %d",
1.45 markus 1491: c->self, c->efd);
1.132 markus 1492: channel_close_fd(&c->efd);
1.93 markus 1493: } else {
1.44 markus 1494: buffer_append(&c->extended, buf, len);
1.93 markus 1495: }
1.44 markus 1496: }
1497: }
1498: return 1;
1499: }
1.127 itojun 1500: static int
1.204 djm 1501: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
1502: {
1503: char buf[16];
1504: int len;
1505:
1506: /* Monitor control fd to detect if the slave client exits */
1507: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1508: len = read(c->ctl_fd, buf, sizeof(buf));
1509: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1510: return 1;
1511: if (len <= 0) {
1512: debug2("channel %d: ctl read<=0", c->self);
1513: if (c->type != SSH_CHANNEL_OPEN) {
1514: debug2("channel %d: not open", c->self);
1515: chan_mark_dead(c);
1516: return -1;
1517: } else {
1518: chan_read_failed(c);
1519: chan_write_failed(c);
1520: }
1521: return -1;
1522: } else
1523: fatal("%s: unexpected data on ctl fd", __func__);
1524: }
1525: return 1;
1526: }
1527: static int
1.93 markus 1528: channel_check_window(Channel *c)
1.44 markus 1529: {
1.104 markus 1530: if (c->type == SSH_CHANNEL_OPEN &&
1531: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1532: c->local_window < c->local_window_max/2 &&
1533: c->local_consumed > 0) {
1534: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1535: packet_put_int(c->remote_id);
1536: packet_put_int(c->local_consumed);
1537: packet_send();
1.70 markus 1538: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1539: c->self, c->local_window,
1540: c->local_consumed);
1541: c->local_window += c->local_consumed;
1542: c->local_consumed = 0;
1.1 deraadt 1543: }
1.41 markus 1544: return 1;
1.1 deraadt 1545: }
1546:
1.127 itojun 1547: static void
1.157 markus 1548: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1549: {
1.137 markus 1550: if (c->delayed)
1551: return;
1.41 markus 1552: channel_handle_rfd(c, readset, writeset);
1553: channel_handle_wfd(c, readset, writeset);
1.157 markus 1554: if (!compat20)
1.137 markus 1555: return;
1.44 markus 1556: channel_handle_efd(c, readset, writeset);
1.204 djm 1557: channel_handle_ctl(c, readset, writeset);
1.93 markus 1558: channel_check_window(c);
1.44 markus 1559: }
1560:
1.127 itojun 1561: static void
1.41 markus 1562: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1563: {
1.41 markus 1564: int len;
1.180 deraadt 1565:
1.41 markus 1566: /* Send buffered output data to the socket. */
1567: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1568: len = write(c->sock, buffer_ptr(&c->output),
1569: buffer_len(&c->output));
1570: if (len <= 0)
1.158 markus 1571: buffer_clear(&c->output);
1.41 markus 1572: else
1573: buffer_consume(&c->output, len);
1574: }
1575: }
1.25 markus 1576:
1.127 itojun 1577: static void
1.44 markus 1578: channel_handler_init_20(void)
1579: {
1.157 markus 1580: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1581: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1582: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1583: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1584: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1585: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1586: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1587: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1588:
1.157 markus 1589: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1590: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1591: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1592: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1593: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1594: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1595: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1596: }
1597:
1.127 itojun 1598: static void
1.41 markus 1599: channel_handler_init_13(void)
1600: {
1601: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1602: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1603: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1604: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1605: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1606: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1607: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1608: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1609: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1610:
1.157 markus 1611: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1612: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1613: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1614: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1615: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1616: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1617: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1618: }
1.25 markus 1619:
1.127 itojun 1620: static void
1.41 markus 1621: channel_handler_init_15(void)
1622: {
1.157 markus 1623: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1624: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1625: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1626: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1627: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1628: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1629: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1630:
1.41 markus 1631: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1632: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1633: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1634: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1635: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1636: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1637: }
1.27 markus 1638:
1.127 itojun 1639: static void
1.41 markus 1640: channel_handler_init(void)
1641: {
1642: int i;
1.180 deraadt 1643:
1.148 deraadt 1644: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1645: channel_pre[i] = NULL;
1646: channel_post[i] = NULL;
1647: }
1.44 markus 1648: if (compat20)
1649: channel_handler_init_20();
1650: else if (compat13)
1.41 markus 1651: channel_handler_init_13();
1652: else
1653: channel_handler_init_15();
1654: }
1.25 markus 1655:
1.140 markus 1656: /* gc dead channels */
1657: static void
1658: channel_garbage_collect(Channel *c)
1659: {
1660: if (c == NULL)
1661: return;
1662: if (c->detach_user != NULL) {
1663: if (!chan_is_dead(c, 0))
1664: return;
1.194 markus 1665: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1666: c->detach_user(c->self, NULL);
1667: /* if we still have a callback */
1668: if (c->detach_user != NULL)
1669: return;
1.194 markus 1670: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1671: }
1672: if (!chan_is_dead(c, 1))
1673: return;
1.194 markus 1674: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1675: channel_free(c);
1676: }
1677:
1.127 itojun 1678: static void
1.41 markus 1679: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1680: {
1681: static int did_init = 0;
1.209 avsm 1682: u_int i;
1.41 markus 1683: Channel *c;
1.25 markus 1684:
1.41 markus 1685: if (!did_init) {
1686: channel_handler_init();
1687: did_init = 1;
1688: }
1689: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1690: c = channels[i];
1691: if (c == NULL)
1.41 markus 1692: continue;
1.118 markus 1693: if (ftab[c->type] != NULL)
1694: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1695: channel_garbage_collect(c);
1.1 deraadt 1696: }
1697: }
1698:
1.121 markus 1699: /*
1700: * Allocate/update select bitmasks and add any bits relevant to channels in
1701: * select bitmasks.
1702: */
1.49 markus 1703: void
1.100 markus 1704: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1705: u_int *nallocp, int rekeying)
1.41 markus 1706: {
1.209 avsm 1707: u_int n, sz;
1.84 markus 1708:
1709: n = MAX(*maxfdp, channel_max_fd);
1710:
1711: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1712: /* perhaps check sz < nalloc/2 and shrink? */
1713: if (*readsetp == NULL || sz > *nallocp) {
1714: *readsetp = xrealloc(*readsetp, sz);
1715: *writesetp = xrealloc(*writesetp, sz);
1716: *nallocp = sz;
1.84 markus 1717: }
1.132 markus 1718: *maxfdp = n;
1.84 markus 1719: memset(*readsetp, 0, sz);
1720: memset(*writesetp, 0, sz);
1721:
1.100 markus 1722: if (!rekeying)
1723: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1724: }
1725:
1.121 markus 1726: /*
1727: * After select, perform any appropriate operations for channels which have
1728: * events pending.
1729: */
1.49 markus 1730: void
1.41 markus 1731: channel_after_select(fd_set * readset, fd_set * writeset)
1732: {
1733: channel_handler(channel_post, readset, writeset);
1734: }
1735:
1.121 markus 1736:
1.84 markus 1737: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1738:
1.49 markus 1739: void
1.142 itojun 1740: channel_output_poll(void)
1.1 deraadt 1741: {
1.41 markus 1742: Channel *c;
1.209 avsm 1743: u_int i, len;
1.1 deraadt 1744:
1.25 markus 1745: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1746: c = channels[i];
1747: if (c == NULL)
1748: continue;
1.37 markus 1749:
1.121 markus 1750: /*
1751: * We are only interested in channels that can have buffered
1752: * incoming data.
1753: */
1.37 markus 1754: if (compat13) {
1.41 markus 1755: if (c->type != SSH_CHANNEL_OPEN &&
1756: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1757: continue;
1758: } else {
1.41 markus 1759: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1760: continue;
1761: }
1.46 markus 1762: if (compat20 &&
1763: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1764: /* XXX is this true? */
1.140 markus 1765: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1766: continue;
1767: }
1.25 markus 1768:
1769: /* Get the amount of buffered data for this channel. */
1.93 markus 1770: if ((c->istate == CHAN_INPUT_OPEN ||
1771: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1772: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1773: /*
1774: * Send some data for the other side over the secure
1775: * connection.
1776: */
1.44 markus 1777: if (compat20) {
1778: if (len > c->remote_window)
1779: len = c->remote_window;
1780: if (len > c->remote_maxpacket)
1781: len = c->remote_maxpacket;
1.25 markus 1782: } else {
1.44 markus 1783: if (packet_is_interactive()) {
1784: if (len > 1024)
1785: len = 512;
1786: } else {
1787: /* Keep the packets at reasonable size. */
1788: if (len > packet_get_maxsize()/2)
1789: len = packet_get_maxsize()/2;
1790: }
1.25 markus 1791: }
1.41 markus 1792: if (len > 0) {
1.44 markus 1793: packet_start(compat20 ?
1794: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1795: packet_put_int(c->remote_id);
1796: packet_put_string(buffer_ptr(&c->input), len);
1797: packet_send();
1798: buffer_consume(&c->input, len);
1799: c->remote_window -= len;
1800: }
1801: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1802: if (compat13)
1803: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1804: /*
1805: * input-buffer is empty and read-socket shutdown:
1.172 markus 1806: * tell peer, that we will not send more data: send IEOF.
1807: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1808: */
1.172 markus 1809: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.210.2.3! brad 1810: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
! 1811: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1812: else
1813: chan_ibuf_empty(c);
1.25 markus 1814: }
1.44 markus 1815: /* Send extended data, i.e. stderr */
1816: if (compat20 &&
1.172 markus 1817: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1818: c->remote_window > 0 &&
1819: (len = buffer_len(&c->extended)) > 0 &&
1820: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1821: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1822: c->self, c->remote_window, buffer_len(&c->extended),
1823: c->extended_usage);
1.44 markus 1824: if (len > c->remote_window)
1825: len = c->remote_window;
1826: if (len > c->remote_maxpacket)
1827: len = c->remote_maxpacket;
1828: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1829: packet_put_int(c->remote_id);
1830: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1831: packet_put_string(buffer_ptr(&c->extended), len);
1832: packet_send();
1833: buffer_consume(&c->extended, len);
1834: c->remote_window -= len;
1.93 markus 1835: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1836: }
1.25 markus 1837: }
1.1 deraadt 1838: }
1839:
1.121 markus 1840:
1841: /* -- protocol input */
1.1 deraadt 1842:
1.49 markus 1843: void
1.154 markus 1844: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1845: {
1.37 markus 1846: int id;
1.25 markus 1847: char *data;
1.77 markus 1848: u_int data_len;
1.41 markus 1849: Channel *c;
1.25 markus 1850:
1851: /* Get the channel number and verify it. */
1.37 markus 1852: id = packet_get_int();
1.41 markus 1853: c = channel_lookup(id);
1854: if (c == NULL)
1.37 markus 1855: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1856:
1857: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1858: if (c->type != SSH_CHANNEL_OPEN &&
1859: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1860: return;
1861:
1.25 markus 1862: /* Get the data. */
1863: data = packet_get_string(&data_len);
1.200 markus 1864:
1865: /*
1866: * Ignore data for protocol > 1.3 if output end is no longer open.
1867: * For protocol 2 the sending side is reducing its window as it sends
1868: * data, so we must 'fake' consumption of the data in order to ensure
1869: * that window updates are sent back. Otherwise the connection might
1870: * deadlock.
1871: */
1872: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1873: if (compat20) {
1874: c->local_window -= data_len;
1875: c->local_consumed += data_len;
1876: }
1877: xfree(data);
1878: return;
1879: }
1.41 markus 1880:
1.143 deraadt 1881: if (compat20) {
1.44 markus 1882: if (data_len > c->local_maxpacket) {
1.188 itojun 1883: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1884: c->self, data_len, c->local_maxpacket);
1885: }
1886: if (data_len > c->local_window) {
1.188 itojun 1887: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1888: c->self, data_len, c->local_window);
1889: xfree(data);
1890: return;
1891: }
1892: c->local_window -= data_len;
1893: }
1.152 markus 1894: packet_check_eom();
1.41 markus 1895: buffer_append(&c->output, data, data_len);
1.25 markus 1896: xfree(data);
1.1 deraadt 1897: }
1.121 markus 1898:
1.49 markus 1899: void
1.154 markus 1900: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1901: {
1902: int id;
1903: char *data;
1.177 markus 1904: u_int data_len, tcode;
1.44 markus 1905: Channel *c;
1906:
1907: /* Get the channel number and verify it. */
1908: id = packet_get_int();
1909: c = channel_lookup(id);
1910:
1911: if (c == NULL)
1912: packet_disconnect("Received extended_data for bad channel %d.", id);
1913: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 1914: logit("channel %d: ext data for non open", id);
1.44 markus 1915: return;
1.172 markus 1916: }
1917: if (c->flags & CHAN_EOF_RCVD) {
1918: if (datafellows & SSH_BUG_EXTEOF)
1919: debug("channel %d: accepting ext data after eof", id);
1920: else
1921: packet_disconnect("Received extended_data after EOF "
1922: "on channel %d.", id);
1.44 markus 1923: }
1924: tcode = packet_get_int();
1925: if (c->efd == -1 ||
1926: c->extended_usage != CHAN_EXTENDED_WRITE ||
1927: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 1928: logit("channel %d: bad ext data", c->self);
1.44 markus 1929: return;
1930: }
1931: data = packet_get_string(&data_len);
1.152 markus 1932: packet_check_eom();
1.44 markus 1933: if (data_len > c->local_window) {
1.188 itojun 1934: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 1935: c->self, data_len, c->local_window);
1936: xfree(data);
1937: return;
1938: }
1.70 markus 1939: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1940: c->local_window -= data_len;
1941: buffer_append(&c->extended, data, data_len);
1942: xfree(data);
1943: }
1944:
1.49 markus 1945: void
1.154 markus 1946: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1947: {
1948: int id;
1949: Channel *c;
1950:
1951: id = packet_get_int();
1.152 markus 1952: packet_check_eom();
1.41 markus 1953: c = channel_lookup(id);
1954: if (c == NULL)
1955: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1956: chan_rcvd_ieof(c);
1.133 markus 1957:
1958: /* XXX force input close */
1.156 markus 1959: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1960: debug("channel %d: FORCE input drain", c->self);
1961: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1962: if (buffer_len(&c->input) == 0)
1963: chan_ibuf_empty(c);
1.133 markus 1964: }
1965:
1.41 markus 1966: }
1.1 deraadt 1967:
1.49 markus 1968: void
1.154 markus 1969: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1970: {
1.41 markus 1971: int id;
1972: Channel *c;
1.1 deraadt 1973:
1.41 markus 1974: id = packet_get_int();
1.152 markus 1975: packet_check_eom();
1.41 markus 1976: c = channel_lookup(id);
1977: if (c == NULL)
1978: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1979:
1980: /*
1981: * Send a confirmation that we have closed the channel and no more
1982: * data is coming for it.
1983: */
1.25 markus 1984: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1985: packet_put_int(c->remote_id);
1.25 markus 1986: packet_send();
1987:
1.27 markus 1988: /*
1989: * If the channel is in closed state, we have sent a close request,
1990: * and the other side will eventually respond with a confirmation.
1991: * Thus, we cannot free the channel here, because then there would be
1992: * no-one to receive the confirmation. The channel gets freed when
1993: * the confirmation arrives.
1994: */
1.41 markus 1995: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1996: /*
1997: * Not a closed channel - mark it as draining, which will
1998: * cause it to be freed later.
1999: */
1.158 markus 2000: buffer_clear(&c->input);
1.41 markus 2001: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2002: }
1.1 deraadt 2003: }
2004:
1.41 markus 2005: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 2006: void
1.154 markus 2007: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2008: {
2009: int id = packet_get_int();
2010: Channel *c = channel_lookup(id);
1.151 markus 2011:
1.152 markus 2012: packet_check_eom();
1.41 markus 2013: if (c == NULL)
2014: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2015: chan_rcvd_oclose(c);
2016: }
1.1 deraadt 2017:
1.49 markus 2018: void
1.154 markus 2019: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2020: {
1.41 markus 2021: int id = packet_get_int();
2022: Channel *c = channel_lookup(id);
1.1 deraadt 2023:
1.152 markus 2024: packet_check_eom();
1.41 markus 2025: if (c == NULL)
2026: packet_disconnect("Received close confirmation for "
2027: "out-of-range channel %d.", id);
2028: if (c->type != SSH_CHANNEL_CLOSED)
2029: packet_disconnect("Received close confirmation for "
2030: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2031: channel_free(c);
1.1 deraadt 2032: }
2033:
1.49 markus 2034: void
1.154 markus 2035: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2036: {
1.41 markus 2037: int id, remote_id;
2038: Channel *c;
1.1 deraadt 2039:
1.41 markus 2040: id = packet_get_int();
2041: c = channel_lookup(id);
1.25 markus 2042:
1.41 markus 2043: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2044: packet_disconnect("Received open confirmation for "
2045: "non-opening channel %d.", id);
2046: remote_id = packet_get_int();
1.27 markus 2047: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2048: c->remote_id = remote_id;
2049: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2050:
2051: if (compat20) {
2052: c->remote_window = packet_get_int();
2053: c->remote_maxpacket = packet_get_int();
1.165 markus 2054: if (c->confirm) {
1.70 markus 2055: debug2("callback start");
1.204 djm 2056: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2057: debug2("callback done");
1.44 markus 2058: }
1.194 markus 2059: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2060: c->remote_window, c->remote_maxpacket);
2061: }
1.152 markus 2062: packet_check_eom();
1.1 deraadt 2063: }
2064:
1.127 itojun 2065: static char *
1.114 markus 2066: reason2txt(int reason)
2067: {
1.143 deraadt 2068: switch (reason) {
1.114 markus 2069: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2070: return "administratively prohibited";
2071: case SSH2_OPEN_CONNECT_FAILED:
2072: return "connect failed";
2073: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2074: return "unknown channel type";
2075: case SSH2_OPEN_RESOURCE_SHORTAGE:
2076: return "resource shortage";
2077: }
1.117 stevesk 2078: return "unknown reason";
1.114 markus 2079: }
2080:
1.49 markus 2081: void
1.154 markus 2082: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2083: {
1.86 markus 2084: int id, reason;
2085: char *msg = NULL, *lang = NULL;
1.41 markus 2086: Channel *c;
2087:
2088: id = packet_get_int();
2089: c = channel_lookup(id);
1.25 markus 2090:
1.41 markus 2091: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2092: packet_disconnect("Received open failure for "
2093: "non-opening channel %d.", id);
1.44 markus 2094: if (compat20) {
1.86 markus 2095: reason = packet_get_int();
1.110 markus 2096: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2097: msg = packet_get_string(NULL);
2098: lang = packet_get_string(NULL);
2099: }
1.188 itojun 2100: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2101: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2102: if (msg != NULL)
2103: xfree(msg);
2104: if (lang != NULL)
2105: xfree(lang);
1.44 markus 2106: }
1.152 markus 2107: packet_check_eom();
1.25 markus 2108: /* Free the channel. This will also close the socket. */
1.113 markus 2109: channel_free(c);
1.44 markus 2110: }
2111:
1.121 markus 2112: void
1.154 markus 2113: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2114: {
2115: Channel *c;
1.178 markus 2116: int id;
2117: u_int adjust;
1.121 markus 2118:
2119: if (!compat20)
2120: return;
2121:
2122: /* Get the channel number and verify it. */
2123: id = packet_get_int();
2124: c = channel_lookup(id);
1.1 deraadt 2125:
1.121 markus 2126: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2127: logit("Received window adjust for "
1.121 markus 2128: "non-open channel %d.", id);
2129: return;
2130: }
2131: adjust = packet_get_int();
1.152 markus 2132: packet_check_eom();
1.178 markus 2133: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2134: c->remote_window += adjust;
2135: }
1.1 deraadt 2136:
1.121 markus 2137: void
1.154 markus 2138: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2139: {
1.121 markus 2140: Channel *c = NULL;
2141: u_short host_port;
2142: char *host, *originator_string;
2143: int remote_id, sock = -1;
2144:
2145: remote_id = packet_get_int();
2146: host = packet_get_string(NULL);
2147: host_port = packet_get_int();
1.25 markus 2148:
1.121 markus 2149: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2150: originator_string = packet_get_string(NULL);
2151: } else {
2152: originator_string = xstrdup("unknown (remote did not supply name)");
2153: }
1.152 markus 2154: packet_check_eom();
1.121 markus 2155: sock = channel_connect_to(host, host_port);
2156: if (sock != -1) {
2157: c = channel_new("connected socket",
2158: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2159: originator_string, 1);
1.167 markus 2160: c->remote_id = remote_id;
1.25 markus 2161: }
1.190 markus 2162: xfree(originator_string);
1.121 markus 2163: if (c == NULL) {
2164: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2165: packet_put_int(remote_id);
2166: packet_send();
2167: }
2168: xfree(host);
1.1 deraadt 2169: }
2170:
1.121 markus 2171:
2172: /* -- tcp forwarding */
1.135 markus 2173:
2174: void
2175: channel_set_af(int af)
2176: {
2177: IPv4or6 = af;
2178: }
1.121 markus 2179:
1.160 markus 2180: static int
2181: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2182: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2183: {
1.113 markus 2184: Channel *c;
1.210.2.1 brad 2185: int sock, r, success = 0, on = 1, wildcard = 0, is_client;
1.35 markus 2186: struct addrinfo hints, *ai, *aitop;
1.210.2.1 brad 2187: const char *host, *addr;
1.35 markus 2188: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2189:
1.160 markus 2190: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2191: listen_addr : host_to_connect;
1.210.2.1 brad 2192: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2193:
1.160 markus 2194: if (host == NULL) {
2195: error("No forward host name.");
1.210.2.3! brad 2196: return 0;
1.73 markus 2197: }
1.113 markus 2198: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2199: error("Forward host name too long.");
1.210.2.3! brad 2200: return 0;
1.87 markus 2201: }
1.25 markus 2202:
1.28 markus 2203: /*
1.210.2.1 brad 2204: * Determine whether or not a port forward listens to loopback,
1.210.2.2 brad 2205: * specified address or wildcard. On the client, a specified bind
2206: * address will always override gateway_ports. On the server, a
2207: * gateway_ports of 1 (``yes'') will override the client's
2208: * specification and force a wildcard bind, whereas a value of 2
2209: * (``clientspecified'') will bind to whatever address the client
1.210.2.1 brad 2210: * asked for.
2211: *
2212: * Special-case listen_addrs are:
2213: *
2214: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2215: * "" (empty string), "*" -> wildcard v4/v6
2216: * "localhost" -> loopback v4/v6
2217: */
2218: addr = NULL;
2219: if (listen_addr == NULL) {
2220: /* No address specified: default to gateway_ports setting */
2221: if (gateway_ports)
2222: wildcard = 1;
2223: } else if (gateway_ports || is_client) {
2224: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2225: strcmp(listen_addr, "0.0.0.0") == 0) ||
2226: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2227: (!is_client && gateway_ports == 1))
2228: wildcard = 1;
2229: else if (strcmp(listen_addr, "localhost") != 0)
2230: addr = listen_addr;
2231: }
2232:
2233: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2234: type, wildcard, (addr == NULL) ? "NULL" : addr);
2235:
2236: /*
1.35 markus 2237: * getaddrinfo returns a loopback address if the hostname is
2238: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2239: */
1.35 markus 2240: memset(&hints, 0, sizeof(hints));
2241: hints.ai_family = IPv4or6;
1.210.2.1 brad 2242: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2243: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2244: snprintf(strport, sizeof strport, "%d", listen_port);
1.210.2.1 brad 2245: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2246: if (addr == NULL) {
2247: /* This really shouldn't happen */
2248: packet_disconnect("getaddrinfo: fatal error: %s",
2249: gai_strerror(r));
2250: } else {
1.210.2.3! brad 2251: error("channel_setup_fwd_listener: "
1.210.2.1 brad 2252: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2253: }
1.210.2.3! brad 2254: return 0;
1.210.2.1 brad 2255: }
1.35 markus 2256:
2257: for (ai = aitop; ai; ai = ai->ai_next) {
2258: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2259: continue;
2260: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2261: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2262: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2263: continue;
2264: }
2265: /* Create a port to listen for the host. */
1.189 markus 2266: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2267: if (sock < 0) {
2268: /* this is no error since kernel may not support ipv6 */
2269: verbose("socket: %.100s", strerror(errno));
2270: continue;
2271: }
2272: /*
1.182 stevesk 2273: * Set socket options.
2274: * Allow local port reuse in TIME_WAIT.
1.35 markus 2275: */
1.182 stevesk 2276: if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
2277: sizeof(on)) == -1)
2278: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
2279:
1.35 markus 2280: debug("Local forwarding listening on %s port %s.", ntop, strport);
2281:
2282: /* Bind the socket to the address. */
2283: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2284: /* address can be in use ipv6 address is already bound */
2285: verbose("bind: %.100s", strerror(errno));
2286: close(sock);
2287: continue;
2288: }
2289: /* Start listening for connections on the socket. */
1.199 markus 2290: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2291: error("listen: %.100s", strerror(errno));
2292: close(sock);
2293: continue;
2294: }
2295: /* Allocate a channel number for the socket. */
1.121 markus 2296: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2297: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2298: 0, "port listener", 1);
1.113 markus 2299: strlcpy(c->path, host, sizeof(c->path));
2300: c->host_port = port_to_connect;
2301: c->listening_port = listen_port;
1.35 markus 2302: success = 1;
2303: }
2304: if (success == 0)
1.160 markus 2305: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2306: listen_port);
1.35 markus 2307: freeaddrinfo(aitop);
1.87 markus 2308: return success;
1.25 markus 2309: }
1.1 deraadt 2310:
1.202 djm 2311: int
2312: channel_cancel_rport_listener(const char *host, u_short port)
2313: {
1.209 avsm 2314: u_int i;
2315: int found = 0;
1.202 djm 2316:
1.210.2.2 brad 2317: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2318: Channel *c = channels[i];
2319:
2320: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2321: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2322: c->listening_port == port) {
1.210 djm 2323: debug2("%s: close channel %d", __func__, i);
1.202 djm 2324: channel_free(c);
2325: found = 1;
2326: }
2327: }
2328:
2329: return (found);
2330: }
2331:
1.160 markus 2332: /* protocol local port fwd, used by ssh (and sshd in v1) */
2333: int
1.210.2.1 brad 2334: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2335: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2336: {
2337: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.210.2.1 brad 2338: listen_host, listen_port, host_to_connect, port_to_connect,
2339: gateway_ports);
1.160 markus 2340: }
2341:
2342: /* protocol v2 remote port fwd, used by sshd */
2343: int
2344: channel_setup_remote_fwd_listener(const char *listen_address,
2345: u_short listen_port, int gateway_ports)
2346: {
2347: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2348: listen_address, listen_port, NULL, 0, gateway_ports);
2349: }
2350:
1.27 markus 2351: /*
2352: * Initiate forwarding of connections to port "port" on remote host through
2353: * the secure channel to host:port from local side.
2354: */
1.1 deraadt 2355:
1.49 markus 2356: void
1.210.2.1 brad 2357: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2358: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2359: {
1.153 markus 2360: int type, success = 0;
1.73 markus 2361:
1.25 markus 2362: /* Record locally that connection to this host/port is permitted. */
2363: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2364: fatal("channel_request_remote_forwarding: too many forwards");
2365:
2366: /* Send the forward request to the remote side. */
1.44 markus 2367: if (compat20) {
1.210.2.1 brad 2368: const char *address_to_bind;
2369: if (listen_host == NULL)
2370: address_to_bind = "localhost";
2371: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2372: address_to_bind = "";
2373: else
2374: address_to_bind = listen_host;
2375:
1.44 markus 2376: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2377: packet_put_cstring("tcpip-forward");
1.173 markus 2378: packet_put_char(1); /* boolean: want reply */
1.44 markus 2379: packet_put_cstring(address_to_bind);
2380: packet_put_int(listen_port);
1.73 markus 2381: packet_send();
2382: packet_write_wait();
2383: /* Assume that server accepts the request */
2384: success = 1;
1.44 markus 2385: } else {
2386: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2387: packet_put_int(listen_port);
2388: packet_put_cstring(host_to_connect);
1.44 markus 2389: packet_put_int(port_to_connect);
2390: packet_send();
2391: packet_write_wait();
1.73 markus 2392:
2393: /* Wait for response from the remote side. */
1.153 markus 2394: type = packet_read();
1.73 markus 2395: switch (type) {
2396: case SSH_SMSG_SUCCESS:
2397: success = 1;
2398: break;
2399: case SSH_SMSG_FAILURE:
1.188 itojun 2400: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2401: break;
2402: default:
2403: /* Unknown packet */
2404: packet_disconnect("Protocol error for port forward request:"
2405: "received packet type %d.", type);
2406: }
2407: }
2408: if (success) {
2409: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2410: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2411: permitted_opens[num_permitted_opens].listen_port = listen_port;
2412: num_permitted_opens++;
1.44 markus 2413: }
1.1 deraadt 2414: }
2415:
1.27 markus 2416: /*
1.208 deraadt 2417: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2418: * local side.
2419: */
2420: void
1.210.2.1 brad 2421: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2422: {
2423: int i;
2424:
2425: if (!compat20)
2426: return;
2427:
2428: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2429: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2430: permitted_opens[i].listen_port == port)
2431: break;
2432: }
2433: if (i >= num_permitted_opens) {
2434: debug("%s: requested forward not found", __func__);
2435: return;
2436: }
2437: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2438: packet_put_cstring("cancel-tcpip-forward");
2439: packet_put_char(0);
1.210.2.1 brad 2440: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2441: packet_put_int(port);
2442: packet_send();
2443:
2444: permitted_opens[i].listen_port = 0;
2445: permitted_opens[i].port_to_connect = 0;
2446: free(permitted_opens[i].host_to_connect);
2447: permitted_opens[i].host_to_connect = NULL;
2448: }
2449:
2450: /*
1.27 markus 2451: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2452: * listening for the port, and sends back a success reply (or disconnect
2453: * message if there was an error). This never returns if there was an error.
2454: */
1.1 deraadt 2455:
1.49 markus 2456: void
1.56 markus 2457: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2458: {
1.31 markus 2459: u_short port, host_port;
1.25 markus 2460: char *hostname;
1.1 deraadt 2461:
1.25 markus 2462: /* Get arguments from the packet. */
2463: port = packet_get_int();
2464: hostname = packet_get_string(NULL);
2465: host_port = packet_get_int();
2466:
1.27 markus 2467: /*
2468: * Check that an unprivileged user is not trying to forward a
2469: * privileged port.
2470: */
1.25 markus 2471: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2472: packet_disconnect(
2473: "Requested forwarding of port %d but user is not root.",
2474: port);
2475: if (host_port == 0)
2476: packet_disconnect("Dynamic forwarding denied.");
2477:
1.73 markus 2478: /* Initiate forwarding */
1.210.2.1 brad 2479: channel_setup_local_fwd_listener(NULL, port, hostname,
2480: host_port, gateway_ports);
1.25 markus 2481:
2482: /* Free the argument string. */
2483: xfree(hostname);
1.1 deraadt 2484: }
2485:
1.99 markus 2486: /*
2487: * Permits opening to any host/port if permitted_opens[] is empty. This is
2488: * usually called by the server, because the user could connect to any port
2489: * anyway, and the server has no way to know but to trust the client anyway.
2490: */
2491: void
1.142 itojun 2492: channel_permit_all_opens(void)
1.99 markus 2493: {
2494: if (num_permitted_opens == 0)
2495: all_opens_permitted = 1;
2496: }
2497:
1.101 markus 2498: void
1.99 markus 2499: channel_add_permitted_opens(char *host, int port)
2500: {
2501: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2502: fatal("channel_request_remote_forwarding: too many forwards");
2503: debug("allow port forwarding to host %s port %d", host, port);
2504:
2505: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2506: permitted_opens[num_permitted_opens].port_to_connect = port;
2507: num_permitted_opens++;
2508:
2509: all_opens_permitted = 0;
2510: }
2511:
1.101 markus 2512: void
1.99 markus 2513: channel_clear_permitted_opens(void)
2514: {
2515: int i;
2516:
2517: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2518: if (permitted_opens[i].host_to_connect != NULL)
2519: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2520: num_permitted_opens = 0;
2521:
2522: }
2523:
2524:
2525: /* return socket to remote host, port */
1.127 itojun 2526: static int
1.99 markus 2527: connect_to(const char *host, u_short port)
1.41 markus 2528: {
2529: struct addrinfo hints, *ai, *aitop;
2530: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2531: int gaierr;
2532: int sock = -1;
2533:
2534: memset(&hints, 0, sizeof(hints));
2535: hints.ai_family = IPv4or6;
2536: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2537: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2538: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2539: error("connect_to %.100s: unknown host (%s)", host,
2540: gai_strerror(gaierr));
1.41 markus 2541: return -1;
2542: }
2543: for (ai = aitop; ai; ai = ai->ai_next) {
2544: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2545: continue;
2546: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2547: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2548: error("connect_to: getnameinfo failed");
1.41 markus 2549: continue;
2550: }
1.189 markus 2551: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2552: if (sock < 0) {
1.186 djm 2553: if (ai->ai_next == NULL)
2554: error("socket: %.100s", strerror(errno));
2555: else
2556: verbose("socket: %.100s", strerror(errno));
1.41 markus 2557: continue;
2558: }
1.205 djm 2559: if (set_nonblock(sock) == -1)
2560: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2561: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2562: errno != EINPROGRESS) {
1.99 markus 2563: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2564: strerror(errno));
2565: close(sock);
1.89 stevesk 2566: continue; /* fail -- try next */
1.41 markus 2567: }
2568: break; /* success */
2569:
2570: }
2571: freeaddrinfo(aitop);
2572: if (!ai) {
1.99 markus 2573: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2574: return -1;
2575: }
2576: /* success */
1.169 stevesk 2577: set_nodelay(sock);
1.41 markus 2578: return sock;
2579: }
1.99 markus 2580:
1.73 markus 2581: int
1.130 stevesk 2582: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2583: {
2584: int i;
1.99 markus 2585:
1.73 markus 2586: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2587: if (permitted_opens[i].host_to_connect != NULL &&
2588: permitted_opens[i].listen_port == listen_port)
1.99 markus 2589: return connect_to(
1.73 markus 2590: permitted_opens[i].host_to_connect,
2591: permitted_opens[i].port_to_connect);
1.74 markus 2592: error("WARNING: Server requests forwarding for unknown listen_port %d",
2593: listen_port);
1.73 markus 2594: return -1;
2595: }
2596:
1.99 markus 2597: /* Check if connecting to that port is permitted and connect. */
2598: int
2599: channel_connect_to(const char *host, u_short port)
2600: {
2601: int i, permit;
2602:
2603: permit = all_opens_permitted;
2604: if (!permit) {
2605: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2606: if (permitted_opens[i].host_to_connect != NULL &&
2607: permitted_opens[i].port_to_connect == port &&
1.99 markus 2608: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2609: permit = 1;
2610:
2611: }
2612: if (!permit) {
1.188 itojun 2613: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2614: "but the request was denied.", host, port);
2615: return -1;
2616: }
2617: return connect_to(host, port);
1.204 djm 2618: }
2619:
2620: void
2621: channel_send_window_changes(void)
2622: {
1.209 avsm 2623: u_int i;
1.204 djm 2624: struct winsize ws;
2625:
2626: for (i = 0; i < channels_alloc; i++) {
1.210.2.2 brad 2627: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2628: channels[i]->type != SSH_CHANNEL_OPEN)
2629: continue;
2630: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2631: continue;
2632: channel_request_start(i, "window-change", 0);
2633: packet_put_int(ws.ws_col);
2634: packet_put_int(ws.ws_row);
2635: packet_put_int(ws.ws_xpixel);
2636: packet_put_int(ws.ws_ypixel);
2637: packet_send();
2638: }
1.99 markus 2639: }
2640:
1.121 markus 2641: /* -- X11 forwarding */
1.1 deraadt 2642:
1.27 markus 2643: /*
2644: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2645: * Returns 0 and a suitable display number for the DISPLAY variable
2646: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2647: */
1.141 stevesk 2648: int
1.163 stevesk 2649: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.210.2.3! brad 2650: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2651: {
1.149 markus 2652: Channel *nc = NULL;
1.31 markus 2653: int display_number, sock;
2654: u_short port;
1.35 markus 2655: struct addrinfo hints, *ai, *aitop;
2656: char strport[NI_MAXSERV];
2657: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2658:
1.33 markus 2659: for (display_number = x11_display_offset;
1.148 deraadt 2660: display_number < MAX_DISPLAYS;
2661: display_number++) {
1.25 markus 2662: port = 6000 + display_number;
1.35 markus 2663: memset(&hints, 0, sizeof(hints));
2664: hints.ai_family = IPv4or6;
1.163 stevesk 2665: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2666: hints.ai_socktype = SOCK_STREAM;
2667: snprintf(strport, sizeof strport, "%d", port);
2668: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2669: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2670: return -1;
1.25 markus 2671: }
1.35 markus 2672: for (ai = aitop; ai; ai = ai->ai_next) {
2673: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2674: continue;
1.189 markus 2675: sock = socket(ai->ai_family, ai->ai_socktype,
2676: ai->ai_protocol);
1.35 markus 2677: if (sock < 0) {
2678: error("socket: %.100s", strerror(errno));
1.203 markus 2679: freeaddrinfo(aitop);
1.141 stevesk 2680: return -1;
1.35 markus 2681: }
2682: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2683: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2684: close(sock);
1.183 itojun 2685:
2686: if (ai->ai_next)
2687: continue;
2688:
1.35 markus 2689: for (n = 0; n < num_socks; n++) {
2690: close(socks[n]);
2691: }
2692: num_socks = 0;
2693: break;
2694: }
2695: socks[num_socks++] = sock;
2696: if (num_socks == NUM_SOCKS)
2697: break;
1.25 markus 2698: }
1.83 stevesk 2699: freeaddrinfo(aitop);
1.35 markus 2700: if (num_socks > 0)
2701: break;
1.25 markus 2702: }
2703: if (display_number >= MAX_DISPLAYS) {
2704: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2705: return -1;
1.25 markus 2706: }
2707: /* Start listening for connections on the socket. */
1.35 markus 2708: for (n = 0; n < num_socks; n++) {
2709: sock = socks[n];
1.199 markus 2710: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2711: error("listen: %.100s", strerror(errno));
2712: close(sock);
1.141 stevesk 2713: return -1;
1.35 markus 2714: }
1.25 markus 2715: }
1.35 markus 2716:
2717: /* Allocate a channel for each socket. */
1.210.2.3! brad 2718: if (chanids != NULL)
! 2719: *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1));
1.35 markus 2720: for (n = 0; n < num_socks; n++) {
2721: sock = socks[n];
1.149 markus 2722: nc = channel_new("x11 listener",
1.51 markus 2723: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2724: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2725: 0, "X11 inet listener", 1);
1.167 markus 2726: nc->single_connection = single_connection;
1.210.2.3! brad 2727: if (*chanids != NULL)
! 2728: (*chanids)[n] = nc->self;
1.35 markus 2729: }
1.210.2.3! brad 2730: if (*chanids != NULL)
! 2731: (*chanids)[n] = -1;
1.1 deraadt 2732:
1.141 stevesk 2733: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2734: *display_numberp = display_number;
2735: return (0);
1.1 deraadt 2736: }
2737:
1.127 itojun 2738: static int
1.77 markus 2739: connect_local_xsocket(u_int dnr)
1.1 deraadt 2740: {
1.25 markus 2741: int sock;
2742: struct sockaddr_un addr;
2743:
1.147 stevesk 2744: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2745: if (sock < 0)
2746: error("socket: %.100s", strerror(errno));
2747: memset(&addr, 0, sizeof(addr));
2748: addr.sun_family = AF_UNIX;
2749: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2750: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2751: return sock;
2752: close(sock);
1.25 markus 2753: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2754: return -1;
1.1 deraadt 2755: }
2756:
1.51 markus 2757: int
2758: x11_connect_display(void)
1.1 deraadt 2759: {
1.162 stevesk 2760: int display_number, sock = 0;
1.25 markus 2761: const char *display;
1.51 markus 2762: char buf[1024], *cp;
1.35 markus 2763: struct addrinfo hints, *ai, *aitop;
2764: char strport[NI_MAXSERV];
2765: int gaierr;
1.25 markus 2766:
2767: /* Try to open a socket for the local X server. */
2768: display = getenv("DISPLAY");
2769: if (!display) {
2770: error("DISPLAY not set.");
1.51 markus 2771: return -1;
1.25 markus 2772: }
1.27 markus 2773: /*
2774: * Now we decode the value of the DISPLAY variable and make a
2775: * connection to the real X server.
2776: */
2777:
2778: /*
2779: * Check if it is a unix domain socket. Unix domain displays are in
2780: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2781: */
1.25 markus 2782: if (strncmp(display, "unix:", 5) == 0 ||
2783: display[0] == ':') {
2784: /* Connect to the unix domain socket. */
2785: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2786: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2787: display);
1.51 markus 2788: return -1;
1.25 markus 2789: }
2790: /* Create a socket. */
2791: sock = connect_local_xsocket(display_number);
2792: if (sock < 0)
1.51 markus 2793: return -1;
1.25 markus 2794:
2795: /* OK, we now have a connection to the display. */
1.51 markus 2796: return sock;
1.25 markus 2797: }
1.27 markus 2798: /*
2799: * Connect to an inet socket. The DISPLAY value is supposedly
2800: * hostname:d[.s], where hostname may also be numeric IP address.
2801: */
1.145 stevesk 2802: strlcpy(buf, display, sizeof(buf));
1.25 markus 2803: cp = strchr(buf, ':');
2804: if (!cp) {
2805: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2806: return -1;
1.25 markus 2807: }
2808: *cp = 0;
1.27 markus 2809: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2810: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2811: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2812: display);
1.51 markus 2813: return -1;
1.25 markus 2814: }
1.35 markus 2815:
2816: /* Look up the host address */
2817: memset(&hints, 0, sizeof(hints));
2818: hints.ai_family = IPv4or6;
2819: hints.ai_socktype = SOCK_STREAM;
2820: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2821: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2822: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2823: return -1;
1.25 markus 2824: }
1.35 markus 2825: for (ai = aitop; ai; ai = ai->ai_next) {
2826: /* Create a socket. */
1.189 markus 2827: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2828: if (sock < 0) {
1.194 markus 2829: debug2("socket: %.100s", strerror(errno));
1.41 markus 2830: continue;
2831: }
2832: /* Connect it to the display. */
2833: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2834: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2835: 6000 + display_number, strerror(errno));
2836: close(sock);
2837: continue;
2838: }
2839: /* Success */
2840: break;
1.35 markus 2841: }
2842: freeaddrinfo(aitop);
2843: if (!ai) {
1.49 markus 2844: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2845: strerror(errno));
1.51 markus 2846: return -1;
1.25 markus 2847: }
1.162 stevesk 2848: set_nodelay(sock);
1.51 markus 2849: return sock;
2850: }
2851:
2852: /*
2853: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2854: * the remote channel number. We should do whatever we want, and respond
2855: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2856: */
2857:
2858: void
1.154 markus 2859: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2860: {
1.113 markus 2861: Channel *c = NULL;
2862: int remote_id, sock = 0;
1.51 markus 2863: char *remote_host;
1.25 markus 2864:
1.113 markus 2865: debug("Received X11 open request.");
1.51 markus 2866:
1.113 markus 2867: remote_id = packet_get_int();
1.121 markus 2868:
2869: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2870: remote_host = packet_get_string(NULL);
1.51 markus 2871: } else {
2872: remote_host = xstrdup("unknown (remote did not supply name)");
2873: }
1.152 markus 2874: packet_check_eom();
1.25 markus 2875:
1.51 markus 2876: /* Obtain a connection to the real X display. */
2877: sock = x11_connect_display();
1.113 markus 2878: if (sock != -1) {
2879: /* Allocate a channel for this connection. */
2880: c = channel_new("connected x11 socket",
2881: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2882: remote_host, 1);
1.167 markus 2883: c->remote_id = remote_id;
2884: c->force_drain = 1;
1.113 markus 2885: }
1.190 markus 2886: xfree(remote_host);
1.113 markus 2887: if (c == NULL) {
1.51 markus 2888: /* Send refusal to the remote host. */
2889: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2890: packet_put_int(remote_id);
1.51 markus 2891: } else {
2892: /* Send a confirmation to the remote host. */
2893: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2894: packet_put_int(remote_id);
2895: packet_put_int(c->self);
1.51 markus 2896: }
1.113 markus 2897: packet_send();
1.72 markus 2898: }
2899:
2900: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2901: void
1.154 markus 2902: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2903: {
2904: int rchan = packet_get_int();
1.180 deraadt 2905:
1.143 deraadt 2906: switch (type) {
1.72 markus 2907: case SSH_SMSG_AGENT_OPEN:
2908: error("Warning: ssh server tried agent forwarding.");
2909: break;
2910: case SSH_SMSG_X11_OPEN:
2911: error("Warning: ssh server tried X11 forwarding.");
2912: break;
2913: default:
1.154 markus 2914: error("deny_input_open: type %d", type);
1.72 markus 2915: break;
2916: }
2917: error("Warning: this is probably a break in attempt by a malicious server.");
2918: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2919: packet_put_int(rchan);
2920: packet_send();
1.1 deraadt 2921: }
2922:
1.27 markus 2923: /*
2924: * Requests forwarding of X11 connections, generates fake authentication
2925: * data, and enables authentication spoofing.
1.121 markus 2926: * This should be called in the client only.
1.27 markus 2927: */
1.49 markus 2928: void
1.210.2.3! brad 2929: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 2930: const char *proto, const char *data)
1.1 deraadt 2931: {
1.77 markus 2932: u_int data_len = (u_int) strlen(data) / 2;
1.210.2.3! brad 2933: u_int i, value;
1.25 markus 2934: char *new_data;
2935: int screen_number;
2936: const char *cp;
1.207 avsm 2937: u_int32_t rnd = 0;
1.25 markus 2938:
1.210.2.3! brad 2939: if (x11_saved_display == NULL)
! 2940: x11_saved_display = xstrdup(disp);
! 2941: else if (strcmp(disp, x11_saved_display) != 0) {
! 2942: error("x11_request_forwarding_with_spoofing: different "
! 2943: "$DISPLAY already forwarded");
! 2944: return;
! 2945: }
! 2946:
! 2947: cp = disp;
! 2948: if (disp)
! 2949: cp = strchr(disp, ':');
1.25 markus 2950: if (cp)
2951: cp = strchr(cp, '.');
2952: if (cp)
2953: screen_number = atoi(cp + 1);
2954: else
2955: screen_number = 0;
2956:
1.210.2.3! brad 2957: if (x11_saved_proto == NULL) {
! 2958: /* Save protocol name. */
! 2959: x11_saved_proto = xstrdup(proto);
! 2960: /*
! 2961: * Extract real authentication data and generate fake data
! 2962: * of the same length.
! 2963: */
! 2964: x11_saved_data = xmalloc(data_len);
! 2965: x11_fake_data = xmalloc(data_len);
! 2966: for (i = 0; i < data_len; i++) {
! 2967: if (sscanf(data + 2 * i, "%2x", &value) != 1)
! 2968: fatal("x11_request_forwarding: bad "
! 2969: "authentication data: %.100s", data);
! 2970: if (i % 4 == 0)
! 2971: rnd = arc4random();
! 2972: x11_saved_data[i] = value;
! 2973: x11_fake_data[i] = rnd & 0xff;
! 2974: rnd >>= 8;
! 2975: }
! 2976: x11_saved_data_len = data_len;
! 2977: x11_fake_data_len = data_len;
1.25 markus 2978: }
2979:
2980: /* Convert the fake data into hex. */
1.210.2.3! brad 2981: new_data = tohex(x11_fake_data, data_len);
1.25 markus 2982:
2983: /* Send the request packet. */
1.51 markus 2984: if (compat20) {
2985: channel_request_start(client_session_id, "x11-req", 0);
2986: packet_put_char(0); /* XXX bool single connection */
2987: } else {
2988: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2989: }
2990: packet_put_cstring(proto);
2991: packet_put_cstring(new_data);
1.25 markus 2992: packet_put_int(screen_number);
2993: packet_send();
2994: packet_write_wait();
2995: xfree(new_data);
1.1 deraadt 2996: }
2997:
1.121 markus 2998:
2999: /* -- agent forwarding */
3000:
1.1 deraadt 3001: /* Sends a message to the server to request authentication fd forwarding. */
3002:
1.49 markus 3003: void
1.142 itojun 3004: auth_request_forwarding(void)
1.1 deraadt 3005: {
1.25 markus 3006: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3007: packet_send();
3008: packet_write_wait();
1.1 deraadt 3009: }
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