Annotation of src/usr.bin/ssh/channels.c, Revision 1.210.2.2
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"
1.210.2.2! brad 42: RCSID("$OpenBSD: channels.c,v 1.214 2005/03/14 11:46:56 markus 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:
114: /* Saved X11 authentication protocol name. */
115: static char *x11_saved_proto = NULL;
116:
117: /* Saved X11 authentication data. This is the real data. */
118: static char *x11_saved_data = NULL;
119: static u_int x11_saved_data_len = 0;
120:
121: /*
122: * Fake X11 authentication data. This is what the server will be sending us;
123: * we should replace any occurrences of this by the real data.
124: */
125: static char *x11_fake_data = NULL;
126: static u_int x11_fake_data_len;
127:
128:
129: /* -- agent forwarding */
130:
131: #define NUM_SOCKS 10
132:
1.82 markus 133: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 134: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 135:
1.121 markus 136: /* helper */
1.127 itojun 137: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 138:
1.121 markus 139: /* -- channel core */
1.41 markus 140:
141: Channel *
142: channel_lookup(int id)
143: {
144: Channel *c;
1.113 markus 145:
1.209 avsm 146: if (id < 0 || (u_int)id >= channels_alloc) {
1.188 itojun 147: logit("channel_lookup: %d: bad id", id);
1.41 markus 148: return NULL;
149: }
1.113 markus 150: c = channels[id];
151: if (c == NULL) {
1.188 itojun 152: logit("channel_lookup: %d: bad id: channel free", id);
1.41 markus 153: return NULL;
154: }
155: return c;
1.55 markus 156: }
157:
1.27 markus 158: /*
1.55 markus 159: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 160: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 161: */
1.1 deraadt 162:
1.127 itojun 163: static void
1.71 markus 164: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
165: int extusage, int nonblock)
1.1 deraadt 166: {
1.25 markus 167: /* Update the maximum file descriptor value. */
1.84 markus 168: channel_max_fd = MAX(channel_max_fd, rfd);
169: channel_max_fd = MAX(channel_max_fd, wfd);
170: channel_max_fd = MAX(channel_max_fd, efd);
171:
1.27 markus 172: /* XXX set close-on-exec -markus */
1.55 markus 173:
1.52 markus 174: c->rfd = rfd;
175: c->wfd = wfd;
176: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 177: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 178: c->efd = efd;
179: c->extended_usage = extusage;
1.71 markus 180:
1.91 markus 181: /* XXX ugly hack: nonblock is only set by the server */
182: if (nonblock && isatty(c->rfd)) {
1.194 markus 183: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 184: c->isatty = 1;
185: if (!isatty(c->wfd)) {
1.94 markus 186: error("channel %d: wfd %d is not a tty?",
1.91 markus 187: c->self, c->wfd);
188: }
189: } else {
190: c->isatty = 0;
191: }
192:
1.71 markus 193: /* enable nonblocking mode */
194: if (nonblock) {
195: if (rfd != -1)
196: set_nonblock(rfd);
197: if (wfd != -1)
198: set_nonblock(wfd);
199: if (efd != -1)
200: set_nonblock(efd);
201: }
1.52 markus 202: }
203:
204: /*
205: * Allocate a new channel object and set its type and socket. This will cause
206: * remote_name to be freed.
207: */
208:
1.113 markus 209: Channel *
1.52 markus 210: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 211: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 212: {
1.209 avsm 213: int found;
214: u_int i;
1.52 markus 215: Channel *c;
1.25 markus 216:
217: /* Do initial allocation if this is the first call. */
218: if (channels_alloc == 0) {
219: channels_alloc = 10;
1.113 markus 220: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 221: for (i = 0; i < channels_alloc; i++)
1.113 markus 222: channels[i] = NULL;
1.25 markus 223: }
224: /* Try to find a free slot where to put the new channel. */
225: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 226: if (channels[i] == NULL) {
1.25 markus 227: /* Found a free slot. */
1.209 avsm 228: found = (int)i;
1.25 markus 229: break;
230: }
1.209 avsm 231: if (found < 0) {
1.27 markus 232: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 233: found = channels_alloc;
1.179 markus 234: if (channels_alloc > 10000)
235: fatal("channel_new: internal error: channels_alloc %d "
236: "too big.", channels_alloc);
1.195 markus 237: channels = xrealloc(channels,
238: (channels_alloc + 10) * sizeof(Channel *));
239: channels_alloc += 10;
1.70 markus 240: debug2("channel: expanding %d", channels_alloc);
1.25 markus 241: for (i = found; i < channels_alloc; i++)
1.113 markus 242: channels[i] = NULL;
1.25 markus 243: }
1.113 markus 244: /* Initialize and return new channel. */
245: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 246: memset(c, 0, sizeof(Channel));
1.25 markus 247: buffer_init(&c->input);
248: buffer_init(&c->output);
1.41 markus 249: buffer_init(&c->extended);
1.159 markus 250: c->ostate = CHAN_OUTPUT_OPEN;
251: c->istate = CHAN_INPUT_OPEN;
252: c->flags = 0;
1.71 markus 253: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 254: c->self = found;
255: c->type = type;
1.41 markus 256: c->ctype = ctype;
1.51 markus 257: c->local_window = window;
258: c->local_window_max = window;
259: c->local_consumed = 0;
260: c->local_maxpacket = maxpack;
1.25 markus 261: c->remote_id = -1;
1.190 markus 262: c->remote_name = xstrdup(remote_name);
1.41 markus 263: c->remote_window = 0;
264: c->remote_maxpacket = 0;
1.133 markus 265: c->force_drain = 0;
1.149 markus 266: c->single_connection = 0;
1.131 markus 267: c->detach_user = NULL;
1.165 markus 268: c->confirm = NULL;
1.204 djm 269: c->confirm_ctx = NULL;
1.65 markus 270: c->input_filter = NULL;
1.25 markus 271: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 272: return c;
1.1 deraadt 273: }
1.52 markus 274:
1.132 markus 275: static int
276: channel_find_maxfd(void)
277: {
1.209 avsm 278: u_int i;
279: int max = 0;
1.132 markus 280: Channel *c;
281:
282: for (i = 0; i < channels_alloc; i++) {
283: c = channels[i];
284: if (c != NULL) {
285: max = MAX(max, c->rfd);
286: max = MAX(max, c->wfd);
287: max = MAX(max, c->efd);
288: }
289: }
290: return max;
291: }
292:
293: int
294: channel_close_fd(int *fdp)
295: {
296: int ret = 0, fd = *fdp;
297:
298: if (fd != -1) {
299: ret = close(fd);
300: *fdp = -1;
301: if (fd == channel_max_fd)
302: channel_max_fd = channel_find_maxfd();
303: }
304: return ret;
305: }
306:
1.52 markus 307: /* Close all channel fd/socket. */
308:
1.127 itojun 309: static void
1.52 markus 310: channel_close_fds(Channel *c)
311: {
1.204 djm 312: debug3("channel %d: close_fds r %d w %d e %d c %d",
313: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 314:
1.132 markus 315: channel_close_fd(&c->sock);
1.204 djm 316: channel_close_fd(&c->ctl_fd);
1.132 markus 317: channel_close_fd(&c->rfd);
318: channel_close_fd(&c->wfd);
319: channel_close_fd(&c->efd);
1.121 markus 320: }
321:
322: /* Free the channel and close its fd/socket. */
323:
324: void
325: channel_free(Channel *c)
326: {
327: char *s;
1.209 avsm 328: u_int i, n;
1.121 markus 329:
330: for (n = 0, i = 0; i < channels_alloc; i++)
331: if (channels[i])
332: n++;
1.209 avsm 333: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 334: c->remote_name ? c->remote_name : "???", n);
335:
336: s = channel_open_message();
1.194 markus 337: debug3("channel %d: status: %s", c->self, s);
1.121 markus 338: xfree(s);
339:
340: if (c->sock != -1)
341: shutdown(c->sock, SHUT_RDWR);
1.204 djm 342: if (c->ctl_fd != -1)
343: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 344: channel_close_fds(c);
345: buffer_free(&c->input);
346: buffer_free(&c->output);
347: buffer_free(&c->extended);
348: if (c->remote_name) {
349: xfree(c->remote_name);
350: c->remote_name = NULL;
351: }
352: channels[c->self] = NULL;
353: xfree(c);
354: }
355:
356: void
1.126 markus 357: channel_free_all(void)
1.121 markus 358: {
1.209 avsm 359: u_int i;
1.121 markus 360:
1.126 markus 361: for (i = 0; i < channels_alloc; i++)
362: if (channels[i] != NULL)
363: channel_free(channels[i]);
1.131 markus 364: }
365:
1.121 markus 366: /*
367: * Closes the sockets/fds of all channels. This is used to close extra file
368: * descriptors after a fork.
369: */
370:
371: void
1.142 itojun 372: channel_close_all(void)
1.121 markus 373: {
1.209 avsm 374: u_int i;
1.121 markus 375:
376: for (i = 0; i < channels_alloc; i++)
377: if (channels[i] != NULL)
378: channel_close_fds(channels[i]);
379: }
380:
381: /*
1.131 markus 382: * Stop listening to channels.
383: */
384:
385: void
386: channel_stop_listening(void)
387: {
1.209 avsm 388: u_int i;
1.131 markus 389: Channel *c;
390:
391: for (i = 0; i < channels_alloc; i++) {
392: c = channels[i];
393: if (c != NULL) {
394: switch (c->type) {
395: case SSH_CHANNEL_AUTH_SOCKET:
396: case SSH_CHANNEL_PORT_LISTENER:
397: case SSH_CHANNEL_RPORT_LISTENER:
398: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 399: channel_close_fd(&c->sock);
1.131 markus 400: channel_free(c);
401: break;
402: }
403: }
404: }
405: }
406:
407: /*
1.121 markus 408: * Returns true if no channel has too much buffered data, and false if one or
409: * more channel is overfull.
410: */
411:
412: int
1.142 itojun 413: channel_not_very_much_buffered_data(void)
1.121 markus 414: {
415: u_int i;
416: Channel *c;
417:
418: for (i = 0; i < channels_alloc; i++) {
419: c = channels[i];
420: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 421: #if 0
422: if (!compat20 &&
423: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 424: debug2("channel %d: big input buffer %d",
1.121 markus 425: c->self, buffer_len(&c->input));
426: return 0;
427: }
1.136 markus 428: #endif
1.121 markus 429: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 430: debug2("channel %d: big output buffer %u > %u",
1.136 markus 431: c->self, buffer_len(&c->output),
432: packet_get_maxsize());
1.121 markus 433: return 0;
434: }
435: }
436: }
437: return 1;
438: }
439:
440: /* Returns true if any channel is still open. */
441:
442: int
1.142 itojun 443: channel_still_open(void)
1.121 markus 444: {
1.209 avsm 445: u_int i;
1.121 markus 446: Channel *c;
447:
448: for (i = 0; i < channels_alloc; i++) {
449: c = channels[i];
450: if (c == NULL)
451: continue;
452: switch (c->type) {
453: case SSH_CHANNEL_X11_LISTENER:
454: case SSH_CHANNEL_PORT_LISTENER:
455: case SSH_CHANNEL_RPORT_LISTENER:
456: case SSH_CHANNEL_CLOSED:
457: case SSH_CHANNEL_AUTH_SOCKET:
458: case SSH_CHANNEL_DYNAMIC:
459: case SSH_CHANNEL_CONNECTING:
460: case SSH_CHANNEL_ZOMBIE:
461: continue;
462: case SSH_CHANNEL_LARVAL:
463: if (!compat20)
464: fatal("cannot happen: SSH_CHANNEL_LARVAL");
465: continue;
466: case SSH_CHANNEL_OPENING:
467: case SSH_CHANNEL_OPEN:
468: case SSH_CHANNEL_X11_OPEN:
469: return 1;
470: case SSH_CHANNEL_INPUT_DRAINING:
471: case SSH_CHANNEL_OUTPUT_DRAINING:
472: if (!compat13)
473: fatal("cannot happen: OUT_DRAIN");
474: return 1;
475: default:
476: fatal("channel_still_open: bad channel type %d", c->type);
477: /* NOTREACHED */
478: }
479: }
480: return 0;
481: }
482:
483: /* Returns the id of an open channel suitable for keepaliving */
484:
485: int
1.142 itojun 486: channel_find_open(void)
1.121 markus 487: {
1.209 avsm 488: u_int i;
1.121 markus 489: Channel *c;
490:
491: for (i = 0; i < channels_alloc; i++) {
492: c = channels[i];
1.206 djm 493: if (c == NULL || c->remote_id < 0)
1.121 markus 494: continue;
495: switch (c->type) {
496: case SSH_CHANNEL_CLOSED:
497: case SSH_CHANNEL_DYNAMIC:
498: case SSH_CHANNEL_X11_LISTENER:
499: case SSH_CHANNEL_PORT_LISTENER:
500: case SSH_CHANNEL_RPORT_LISTENER:
501: case SSH_CHANNEL_OPENING:
502: case SSH_CHANNEL_CONNECTING:
503: case SSH_CHANNEL_ZOMBIE:
504: continue;
505: case SSH_CHANNEL_LARVAL:
506: case SSH_CHANNEL_AUTH_SOCKET:
507: case SSH_CHANNEL_OPEN:
508: case SSH_CHANNEL_X11_OPEN:
509: return i;
510: case SSH_CHANNEL_INPUT_DRAINING:
511: case SSH_CHANNEL_OUTPUT_DRAINING:
512: if (!compat13)
513: fatal("cannot happen: OUT_DRAIN");
514: return i;
515: default:
516: fatal("channel_find_open: bad channel type %d", c->type);
517: /* NOTREACHED */
518: }
519: }
520: return -1;
521: }
522:
523:
524: /*
525: * Returns a message describing the currently open forwarded connections,
526: * suitable for sending to the client. The message contains crlf pairs for
527: * newlines.
528: */
529:
530: char *
1.142 itojun 531: channel_open_message(void)
1.121 markus 532: {
533: Buffer buffer;
534: Channel *c;
535: char buf[1024], *cp;
1.209 avsm 536: u_int i;
1.121 markus 537:
538: buffer_init(&buffer);
539: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
540: buffer_append(&buffer, buf, strlen(buf));
541: for (i = 0; i < channels_alloc; i++) {
542: c = channels[i];
543: if (c == NULL)
544: continue;
545: switch (c->type) {
546: case SSH_CHANNEL_X11_LISTENER:
547: case SSH_CHANNEL_PORT_LISTENER:
548: case SSH_CHANNEL_RPORT_LISTENER:
549: case SSH_CHANNEL_CLOSED:
550: case SSH_CHANNEL_AUTH_SOCKET:
551: case SSH_CHANNEL_ZOMBIE:
552: continue;
553: case SSH_CHANNEL_LARVAL:
554: case SSH_CHANNEL_OPENING:
555: case SSH_CHANNEL_CONNECTING:
556: case SSH_CHANNEL_DYNAMIC:
557: case SSH_CHANNEL_OPEN:
558: case SSH_CHANNEL_X11_OPEN:
559: case SSH_CHANNEL_INPUT_DRAINING:
560: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 561: snprintf(buf, sizeof buf,
562: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 563: c->self, c->remote_name,
564: c->type, c->remote_id,
565: c->istate, buffer_len(&c->input),
566: c->ostate, buffer_len(&c->output),
1.204 djm 567: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 568: buffer_append(&buffer, buf, strlen(buf));
569: continue;
570: default:
571: fatal("channel_open_message: bad channel type %d", c->type);
572: /* NOTREACHED */
573: }
574: }
575: buffer_append(&buffer, "\0", 1);
576: cp = xstrdup(buffer_ptr(&buffer));
577: buffer_free(&buffer);
578: return cp;
579: }
580:
581: void
582: channel_send_open(int id)
583: {
584: Channel *c = channel_lookup(id);
1.180 deraadt 585:
1.121 markus 586: if (c == NULL) {
1.188 itojun 587: logit("channel_send_open: %d: bad id", id);
1.121 markus 588: return;
589: }
1.184 markus 590: debug2("channel %d: send open", id);
1.121 markus 591: packet_start(SSH2_MSG_CHANNEL_OPEN);
592: packet_put_cstring(c->ctype);
593: packet_put_int(c->self);
594: packet_put_int(c->local_window);
595: packet_put_int(c->local_maxpacket);
596: packet_send();
597: }
598:
599: void
1.184 markus 600: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 601: {
1.184 markus 602: Channel *c = channel_lookup(id);
1.180 deraadt 603:
1.121 markus 604: if (c == NULL) {
1.188 itojun 605: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 606: return;
607: }
1.204 djm 608: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 609: packet_start(SSH2_MSG_CHANNEL_REQUEST);
610: packet_put_int(c->remote_id);
611: packet_put_cstring(service);
612: packet_put_char(wantconfirm);
613: }
614: void
1.204 djm 615: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 616: {
617: Channel *c = channel_lookup(id);
1.180 deraadt 618:
1.121 markus 619: if (c == NULL) {
1.188 itojun 620: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 621: return;
622: }
1.165 markus 623: c->confirm = fn;
1.204 djm 624: c->confirm_ctx = ctx;
1.121 markus 625: }
626: void
627: channel_register_cleanup(int id, channel_callback_fn *fn)
628: {
629: Channel *c = channel_lookup(id);
1.180 deraadt 630:
1.121 markus 631: if (c == NULL) {
1.188 itojun 632: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 633: return;
634: }
1.131 markus 635: c->detach_user = fn;
1.121 markus 636: }
637: void
638: channel_cancel_cleanup(int id)
639: {
640: Channel *c = channel_lookup(id);
1.180 deraadt 641:
1.121 markus 642: if (c == NULL) {
1.188 itojun 643: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 644: return;
1.52 markus 645: }
1.131 markus 646: c->detach_user = NULL;
1.121 markus 647: }
648: void
649: channel_register_filter(int id, channel_filter_fn *fn)
650: {
651: Channel *c = channel_lookup(id);
1.180 deraadt 652:
1.121 markus 653: if (c == NULL) {
1.188 itojun 654: logit("channel_register_filter: %d: bad id", id);
1.121 markus 655: return;
1.52 markus 656: }
1.121 markus 657: c->input_filter = fn;
1.52 markus 658: }
659:
1.49 markus 660: void
1.121 markus 661: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 662: int extusage, int nonblock, u_int window_max)
1.1 deraadt 663: {
1.121 markus 664: Channel *c = channel_lookup(id);
1.180 deraadt 665:
1.121 markus 666: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
667: fatal("channel_activate for non-larval channel %d.", id);
668: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
669: c->type = SSH_CHANNEL_OPEN;
1.168 markus 670: c->local_window = c->local_window_max = window_max;
1.121 markus 671: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
672: packet_put_int(c->remote_id);
673: packet_put_int(c->local_window);
674: packet_send();
1.1 deraadt 675: }
676:
1.27 markus 677: /*
1.41 markus 678: * 'channel_pre*' are called just before select() to add any bits relevant to
679: * channels in the select bitmasks.
680: */
681: /*
682: * 'channel_post*': perform any appropriate operations for channels which
683: * have events pending.
1.27 markus 684: */
1.41 markus 685: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
686: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
687: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
688:
1.127 itojun 689: static void
1.41 markus 690: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
691: {
692: FD_SET(c->sock, readset);
693: }
694:
1.127 itojun 695: static void
1.75 markus 696: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
697: {
698: debug3("channel %d: waiting for connection", c->self);
699: FD_SET(c->sock, writeset);
700: }
701:
1.127 itojun 702: static void
1.41 markus 703: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
704: {
705: if (buffer_len(&c->input) < packet_get_maxsize())
706: FD_SET(c->sock, readset);
707: if (buffer_len(&c->output) > 0)
708: FD_SET(c->sock, writeset);
709: }
1.1 deraadt 710:
1.127 itojun 711: static void
1.157 markus 712: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 713: {
1.157 markus 714: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 715:
1.210.2.2! brad 716: /* check buffer limits */
! 717: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
! 718:
1.44 markus 719: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 720: limit > 0 &&
721: buffer_len(&c->input) < limit)
1.44 markus 722: FD_SET(c->rfd, readset);
723: if (c->ostate == CHAN_OUTPUT_OPEN ||
724: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
725: if (buffer_len(&c->output) > 0) {
726: FD_SET(c->wfd, writeset);
727: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 728: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.174 markus 729: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
730: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 731: else
732: chan_obuf_empty(c);
1.44 markus 733: }
734: }
735: /** XXX check close conditions, too */
1.157 markus 736: if (compat20 && c->efd != -1) {
1.44 markus 737: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
738: buffer_len(&c->extended) > 0)
739: FD_SET(c->efd, writeset);
1.172 markus 740: else if (!(c->flags & CHAN_EOF_SENT) &&
741: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 742: buffer_len(&c->extended) < c->remote_window)
743: FD_SET(c->efd, readset);
744: }
1.204 djm 745: /* XXX: What about efd? races? */
1.208 deraadt 746: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 747: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
748: FD_SET(c->ctl_fd, readset);
1.44 markus 749: }
750:
1.127 itojun 751: static void
1.41 markus 752: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
753: {
754: if (buffer_len(&c->input) == 0) {
755: packet_start(SSH_MSG_CHANNEL_CLOSE);
756: packet_put_int(c->remote_id);
757: packet_send();
758: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 759: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 760: }
761: }
762:
1.127 itojun 763: static void
1.41 markus 764: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
765: {
766: if (buffer_len(&c->output) == 0)
1.113 markus 767: chan_mark_dead(c);
1.49 markus 768: else
1.41 markus 769: FD_SET(c->sock, writeset);
770: }
771:
772: /*
773: * This is a special state for X11 authentication spoofing. An opened X11
774: * connection (when authentication spoofing is being done) remains in this
775: * state until the first packet has been completely read. The authentication
776: * data in that packet is then substituted by the real data if it matches the
777: * fake data, and the channel is put into normal mode.
1.51 markus 778: * XXX All this happens at the client side.
1.121 markus 779: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 780: */
1.127 itojun 781: static int
1.121 markus 782: x11_open_helper(Buffer *b)
1.1 deraadt 783: {
1.77 markus 784: u_char *ucp;
785: u_int proto_len, data_len;
1.25 markus 786:
1.41 markus 787: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 788: if (buffer_len(b) < 12)
1.41 markus 789: return 0;
790:
791: /* Parse the lengths of variable-length fields. */
1.155 stevesk 792: ucp = buffer_ptr(b);
1.41 markus 793: if (ucp[0] == 0x42) { /* Byte order MSB first. */
794: proto_len = 256 * ucp[6] + ucp[7];
795: data_len = 256 * ucp[8] + ucp[9];
796: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
797: proto_len = ucp[6] + 256 * ucp[7];
798: data_len = ucp[8] + 256 * ucp[9];
799: } else {
1.194 markus 800: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 801: ucp[0]);
1.41 markus 802: return -1;
803: }
804:
805: /* Check if the whole packet is in buffer. */
1.121 markus 806: if (buffer_len(b) <
1.41 markus 807: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
808: return 0;
809:
810: /* Check if authentication protocol matches. */
811: if (proto_len != strlen(x11_saved_proto) ||
812: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 813: debug2("X11 connection uses different authentication protocol.");
1.41 markus 814: return -1;
815: }
816: /* Check if authentication data matches our fake data. */
817: if (data_len != x11_fake_data_len ||
818: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
819: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 820: debug2("X11 auth data does not match fake data.");
1.41 markus 821: return -1;
822: }
823: /* Check fake data length */
824: if (x11_fake_data_len != x11_saved_data_len) {
825: error("X11 fake_data_len %d != saved_data_len %d",
826: x11_fake_data_len, x11_saved_data_len);
827: return -1;
828: }
829: /*
830: * Received authentication protocol and data match
831: * our fake data. Substitute the fake data with real
832: * data.
833: */
834: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
835: x11_saved_data, x11_saved_data_len);
836: return 1;
837: }
838:
1.127 itojun 839: static void
1.41 markus 840: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
841: {
1.121 markus 842: int ret = x11_open_helper(&c->output);
1.180 deraadt 843:
1.41 markus 844: if (ret == 1) {
845: /* Start normal processing for the channel. */
846: c->type = SSH_CHANNEL_OPEN;
1.47 markus 847: channel_pre_open_13(c, readset, writeset);
1.41 markus 848: } else if (ret == -1) {
849: /*
850: * We have received an X11 connection that has bad
851: * authentication information.
852: */
1.188 itojun 853: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 854: buffer_clear(&c->input);
855: buffer_clear(&c->output);
1.132 markus 856: channel_close_fd(&c->sock);
1.41 markus 857: c->sock = -1;
858: c->type = SSH_CHANNEL_CLOSED;
859: packet_start(SSH_MSG_CHANNEL_CLOSE);
860: packet_put_int(c->remote_id);
861: packet_send();
862: }
863: }
1.25 markus 864:
1.127 itojun 865: static void
1.51 markus 866: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 867: {
1.121 markus 868: int ret = x11_open_helper(&c->output);
1.133 markus 869:
870: /* c->force_drain = 1; */
871:
1.41 markus 872: if (ret == 1) {
873: c->type = SSH_CHANNEL_OPEN;
1.157 markus 874: channel_pre_open(c, readset, writeset);
1.41 markus 875: } else if (ret == -1) {
1.188 itojun 876: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 877: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 878: chan_read_failed(c);
879: buffer_clear(&c->input);
880: chan_ibuf_empty(c);
881: buffer_clear(&c->output);
882: /* for proto v1, the peer will send an IEOF */
883: if (compat20)
884: chan_write_failed(c);
885: else
886: c->type = SSH_CHANNEL_OPEN;
1.194 markus 887: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 888: }
889: }
1.25 markus 890:
1.104 markus 891: /* try to decode a socks4 header */
1.127 itojun 892: static int
1.104 markus 893: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 894: {
1.181 markus 895: char *p, *host;
1.109 markus 896: int len, have, i, found;
1.148 deraadt 897: char username[256];
1.103 markus 898: struct {
899: u_int8_t version;
900: u_int8_t command;
901: u_int16_t dest_port;
1.104 markus 902: struct in_addr dest_addr;
1.103 markus 903: } s4_req, s4_rsp;
904:
1.104 markus 905: debug2("channel %d: decode socks4", c->self);
1.109 markus 906:
907: have = buffer_len(&c->input);
908: len = sizeof(s4_req);
909: if (have < len)
910: return 0;
911: p = buffer_ptr(&c->input);
912: for (found = 0, i = len; i < have; i++) {
913: if (p[i] == '\0') {
914: found = 1;
915: break;
916: }
917: if (i > 1024) {
918: /* the peer is probably sending garbage */
919: debug("channel %d: decode socks4: too long",
920: c->self);
921: return -1;
922: }
923: }
924: if (!found)
925: return 0;
1.103 markus 926: buffer_get(&c->input, (char *)&s4_req.version, 1);
927: buffer_get(&c->input, (char *)&s4_req.command, 1);
928: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 929: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 930: have = buffer_len(&c->input);
1.103 markus 931: p = buffer_ptr(&c->input);
932: len = strlen(p);
1.106 markus 933: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 934: if (len > have)
1.104 markus 935: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 936: c->self, len, have);
937: strlcpy(username, p, sizeof(username));
938: buffer_consume(&c->input, len);
939: buffer_consume(&c->input, 1); /* trailing '\0' */
940:
1.104 markus 941: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 942: strlcpy(c->path, host, sizeof(c->path));
943: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 944:
1.194 markus 945: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 946: c->self, host, c->host_port, s4_req.command);
1.103 markus 947:
1.104 markus 948: if (s4_req.command != 1) {
949: debug("channel %d: cannot handle: socks4 cn %d",
950: c->self, s4_req.command);
951: return -1;
1.103 markus 952: }
1.104 markus 953: s4_rsp.version = 0; /* vn: 0 for reply */
954: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 955: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 956: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 957: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 958: return 1;
959: }
960:
1.193 markus 961: /* try to decode a socks5 header */
962: #define SSH_SOCKS5_AUTHDONE 0x1000
963: #define SSH_SOCKS5_NOAUTH 0x00
964: #define SSH_SOCKS5_IPV4 0x01
965: #define SSH_SOCKS5_DOMAIN 0x03
966: #define SSH_SOCKS5_IPV6 0x04
967: #define SSH_SOCKS5_CONNECT 0x01
968: #define SSH_SOCKS5_SUCCESS 0x00
969:
970: static int
971: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
972: {
973: struct {
974: u_int8_t version;
975: u_int8_t command;
976: u_int8_t reserved;
977: u_int8_t atyp;
978: } s5_req, s5_rsp;
979: u_int16_t dest_port;
980: u_char *p, dest_addr[255+1];
981: int i, have, found, nmethods, addrlen, af;
982:
983: debug2("channel %d: decode socks5", c->self);
984: p = buffer_ptr(&c->input);
985: if (p[0] != 0x05)
986: return -1;
987: have = buffer_len(&c->input);
988: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
989: /* format: ver | nmethods | methods */
1.198 djm 990: if (have < 2)
1.193 markus 991: return 0;
992: nmethods = p[1];
993: if (have < nmethods + 2)
994: return 0;
995: /* look for method: "NO AUTHENTICATION REQUIRED" */
996: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
997: if (p[i] == SSH_SOCKS5_NOAUTH ) {
998: found = 1;
999: break;
1000: }
1001: }
1002: if (!found) {
1003: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1004: c->self);
1005: return -1;
1006: }
1007: buffer_consume(&c->input, nmethods + 2);
1008: buffer_put_char(&c->output, 0x05); /* version */
1009: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1010: FD_SET(c->sock, writeset);
1011: c->flags |= SSH_SOCKS5_AUTHDONE;
1012: debug2("channel %d: socks5 auth done", c->self);
1013: return 0; /* need more */
1014: }
1015: debug2("channel %d: socks5 post auth", c->self);
1016: if (have < sizeof(s5_req)+1)
1017: return 0; /* need more */
1018: memcpy((char *)&s5_req, p, sizeof(s5_req));
1019: if (s5_req.version != 0x05 ||
1020: s5_req.command != SSH_SOCKS5_CONNECT ||
1021: s5_req.reserved != 0x00) {
1.194 markus 1022: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1023: return -1;
1024: }
1.210.2.2! brad 1025: switch (s5_req.atyp){
1.193 markus 1026: case SSH_SOCKS5_IPV4:
1027: addrlen = 4;
1028: af = AF_INET;
1029: break;
1030: case SSH_SOCKS5_DOMAIN:
1031: addrlen = p[sizeof(s5_req)];
1032: af = -1;
1033: break;
1034: case SSH_SOCKS5_IPV6:
1035: addrlen = 16;
1036: af = AF_INET6;
1037: break;
1038: default:
1.194 markus 1039: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1040: return -1;
1041: }
1042: if (have < 4 + addrlen + 2)
1043: return 0;
1044: buffer_consume(&c->input, sizeof(s5_req));
1045: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1046: buffer_consume(&c->input, 1); /* host string length */
1047: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1048: buffer_get(&c->input, (char *)&dest_port, 2);
1049: dest_addr[addrlen] = '\0';
1050: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1051: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1052: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1053: return -1;
1054: c->host_port = ntohs(dest_port);
1.198 djm 1055:
1.194 markus 1056: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1057: c->self, c->path, c->host_port, s5_req.command);
1058:
1059: s5_rsp.version = 0x05;
1060: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1061: s5_rsp.reserved = 0; /* ignored */
1062: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1063: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1064: dest_port = 0; /* ignored */
1065:
1066: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1067: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1068: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1069: return 1;
1070: }
1071:
1.104 markus 1072: /* dynamic port forwarding */
1.127 itojun 1073: static void
1.104 markus 1074: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1075: {
1076: u_char *p;
1077: int have, ret;
1.103 markus 1078:
1.104 markus 1079: have = buffer_len(&c->input);
1.137 markus 1080: c->delayed = 0;
1.104 markus 1081: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1082: /* buffer_dump(&c->input); */
1.104 markus 1083: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1084: if (have < 3) {
1.104 markus 1085: /* need more */
1086: FD_SET(c->sock, readset);
1087: return;
1088: }
1089: /* try to guess the protocol */
1090: p = buffer_ptr(&c->input);
1091: switch (p[0]) {
1092: case 0x04:
1093: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1094: break;
1095: case 0x05:
1096: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1097: break;
1098: default:
1099: ret = -1;
1100: break;
1101: }
1102: if (ret < 0) {
1.113 markus 1103: chan_mark_dead(c);
1.104 markus 1104: } else if (ret == 0) {
1105: debug2("channel %d: pre_dynamic: need more", c->self);
1106: /* need more */
1107: FD_SET(c->sock, readset);
1108: } else {
1109: /* switch to the next state */
1110: c->type = SSH_CHANNEL_OPENING;
1111: port_open_helper(c, "direct-tcpip");
1112: }
1.103 markus 1113: }
1114:
1.41 markus 1115: /* This is our fake X11 server socket. */
1.127 itojun 1116: static void
1.41 markus 1117: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1118: {
1.113 markus 1119: Channel *nc;
1.41 markus 1120: struct sockaddr addr;
1.162 stevesk 1121: int newsock;
1.41 markus 1122: socklen_t addrlen;
1.85 markus 1123: char buf[16384], *remote_ipaddr;
1.51 markus 1124: int remote_port;
1.25 markus 1125:
1.41 markus 1126: if (FD_ISSET(c->sock, readset)) {
1127: debug("X11 connection requested.");
1128: addrlen = sizeof(addr);
1129: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1130: if (c->single_connection) {
1.194 markus 1131: debug2("single_connection: closing X11 listener.");
1.149 markus 1132: channel_close_fd(&c->sock);
1133: chan_mark_dead(c);
1134: }
1.41 markus 1135: if (newsock < 0) {
1136: error("accept: %.100s", strerror(errno));
1137: return;
1138: }
1.162 stevesk 1139: set_nodelay(newsock);
1.85 markus 1140: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1141: remote_port = get_peer_port(newsock);
1.41 markus 1142: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1143: remote_ipaddr, remote_port);
1.51 markus 1144:
1.113 markus 1145: nc = channel_new("accepted x11 socket",
1.51 markus 1146: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1147: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1148: if (compat20) {
1149: packet_start(SSH2_MSG_CHANNEL_OPEN);
1150: packet_put_cstring("x11");
1.113 markus 1151: packet_put_int(nc->self);
1.149 markus 1152: packet_put_int(nc->local_window_max);
1153: packet_put_int(nc->local_maxpacket);
1.85 markus 1154: /* originator ipaddr and port */
1155: packet_put_cstring(remote_ipaddr);
1.57 markus 1156: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1157: debug2("ssh2 x11 bug compat mode");
1.57 markus 1158: } else {
1159: packet_put_int(remote_port);
1160: }
1.51 markus 1161: packet_send();
1162: } else {
1163: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1164: packet_put_int(nc->self);
1.121 markus 1165: if (packet_get_protocol_flags() &
1166: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1167: packet_put_cstring(buf);
1.51 markus 1168: packet_send();
1169: }
1.85 markus 1170: xfree(remote_ipaddr);
1.41 markus 1171: }
1172: }
1.25 markus 1173:
1.127 itojun 1174: static void
1.103 markus 1175: port_open_helper(Channel *c, char *rtype)
1176: {
1177: int direct;
1178: char buf[1024];
1179: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1180: u_short remote_port = get_peer_port(c->sock);
1181:
1182: direct = (strcmp(rtype, "direct-tcpip") == 0);
1183:
1184: snprintf(buf, sizeof buf,
1185: "%s: listening port %d for %.100s port %d, "
1186: "connect from %.200s port %d",
1187: rtype, c->listening_port, c->path, c->host_port,
1188: remote_ipaddr, remote_port);
1189:
1190: xfree(c->remote_name);
1191: c->remote_name = xstrdup(buf);
1192:
1193: if (compat20) {
1194: packet_start(SSH2_MSG_CHANNEL_OPEN);
1195: packet_put_cstring(rtype);
1196: packet_put_int(c->self);
1197: packet_put_int(c->local_window_max);
1198: packet_put_int(c->local_maxpacket);
1199: if (direct) {
1200: /* target host, port */
1201: packet_put_cstring(c->path);
1202: packet_put_int(c->host_port);
1203: } else {
1204: /* listen address, port */
1205: packet_put_cstring(c->path);
1206: packet_put_int(c->listening_port);
1207: }
1208: /* originator host and port */
1209: packet_put_cstring(remote_ipaddr);
1210: packet_put_int(remote_port);
1211: packet_send();
1212: } else {
1213: packet_start(SSH_MSG_PORT_OPEN);
1214: packet_put_int(c->self);
1215: packet_put_cstring(c->path);
1216: packet_put_int(c->host_port);
1.121 markus 1217: if (packet_get_protocol_flags() &
1218: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1219: packet_put_cstring(c->remote_name);
1220: packet_send();
1221: }
1222: xfree(remote_ipaddr);
1223: }
1224:
1.41 markus 1225: /*
1226: * This socket is listening for connections to a forwarded TCP/IP port.
1227: */
1.127 itojun 1228: static void
1.41 markus 1229: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1230: {
1.103 markus 1231: Channel *nc;
1.41 markus 1232: struct sockaddr addr;
1.113 markus 1233: int newsock, nextstate;
1.41 markus 1234: socklen_t addrlen;
1.103 markus 1235: char *rtype;
1.73 markus 1236:
1.41 markus 1237: if (FD_ISSET(c->sock, readset)) {
1238: debug("Connection to port %d forwarding "
1239: "to %.100s port %d requested.",
1240: c->listening_port, c->path, c->host_port);
1.103 markus 1241:
1.137 markus 1242: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1243: nextstate = SSH_CHANNEL_OPENING;
1244: rtype = "forwarded-tcpip";
1245: } else {
1246: if (c->host_port == 0) {
1247: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1248: rtype = "dynamic-tcpip";
1.137 markus 1249: } else {
1250: nextstate = SSH_CHANNEL_OPENING;
1251: rtype = "direct-tcpip";
1252: }
1253: }
1.103 markus 1254:
1.41 markus 1255: addrlen = sizeof(addr);
1256: newsock = accept(c->sock, &addr, &addrlen);
1257: if (newsock < 0) {
1258: error("accept: %.100s", strerror(errno));
1259: return;
1260: }
1.169 stevesk 1261: set_nodelay(newsock);
1.190 markus 1262: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1263: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1264: nc->listening_port = c->listening_port;
1265: nc->host_port = c->host_port;
1266: strlcpy(nc->path, c->path, sizeof(nc->path));
1267:
1.137 markus 1268: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1269: /*
1270: * do not call the channel_post handler until
1271: * this flag has been reset by a pre-handler.
1272: * otherwise the FD_ISSET calls might overflow
1273: */
1274: nc->delayed = 1;
1275: } else {
1.103 markus 1276: port_open_helper(nc, rtype);
1.137 markus 1277: }
1.41 markus 1278: }
1279: }
1.25 markus 1280:
1.41 markus 1281: /*
1282: * This is the authentication agent socket listening for connections from
1283: * clients.
1284: */
1.127 itojun 1285: static void
1.41 markus 1286: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1287: {
1.113 markus 1288: Channel *nc;
1289: int newsock;
1.41 markus 1290: struct sockaddr addr;
1291: socklen_t addrlen;
1.25 markus 1292:
1.41 markus 1293: if (FD_ISSET(c->sock, readset)) {
1294: addrlen = sizeof(addr);
1295: newsock = accept(c->sock, &addr, &addrlen);
1296: if (newsock < 0) {
1297: error("accept from auth socket: %.100s", strerror(errno));
1298: return;
1299: }
1.113 markus 1300: nc = channel_new("accepted auth socket",
1.73 markus 1301: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1302: c->local_window_max, c->local_maxpacket,
1.190 markus 1303: 0, "accepted auth socket", 1);
1.73 markus 1304: if (compat20) {
1305: packet_start(SSH2_MSG_CHANNEL_OPEN);
1306: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1307: packet_put_int(nc->self);
1.73 markus 1308: packet_put_int(c->local_window_max);
1309: packet_put_int(c->local_maxpacket);
1310: } else {
1311: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1312: packet_put_int(nc->self);
1.73 markus 1313: }
1.41 markus 1314: packet_send();
1315: }
1316: }
1.25 markus 1317:
1.127 itojun 1318: static void
1.75 markus 1319: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1320: {
1.114 markus 1321: int err = 0;
1.129 stevesk 1322: socklen_t sz = sizeof(err);
1.114 markus 1323:
1.75 markus 1324: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1325: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1326: err = errno;
1327: error("getsockopt SO_ERROR failed");
1328: }
1329: if (err == 0) {
1330: debug("channel %d: connected", c->self);
1331: c->type = SSH_CHANNEL_OPEN;
1332: if (compat20) {
1333: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1334: packet_put_int(c->remote_id);
1335: packet_put_int(c->self);
1336: packet_put_int(c->local_window);
1337: packet_put_int(c->local_maxpacket);
1338: } else {
1339: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1340: packet_put_int(c->remote_id);
1341: packet_put_int(c->self);
1342: }
1.75 markus 1343: } else {
1.114 markus 1344: debug("channel %d: not connected: %s",
1345: c->self, strerror(err));
1346: if (compat20) {
1347: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1348: packet_put_int(c->remote_id);
1349: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1350: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1351: packet_put_cstring(strerror(err));
1352: packet_put_cstring("");
1353: }
1.75 markus 1354: } else {
1.114 markus 1355: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1356: packet_put_int(c->remote_id);
1.75 markus 1357: }
1.114 markus 1358: chan_mark_dead(c);
1.75 markus 1359: }
1.114 markus 1360: packet_send();
1.75 markus 1361: }
1362: }
1363:
1.127 itojun 1364: static int
1.41 markus 1365: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1366: {
1.210.2.2! brad 1367: char buf[CHAN_RBUF];
1.41 markus 1368: int len;
1.25 markus 1369:
1.118 markus 1370: if (c->rfd != -1 &&
1.41 markus 1371: FD_ISSET(c->rfd, readset)) {
1372: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1373: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1374: return 1;
1.41 markus 1375: if (len <= 0) {
1.194 markus 1376: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1377: c->self, c->rfd, len);
1.104 markus 1378: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1379: debug2("channel %d: not open", c->self);
1.113 markus 1380: chan_mark_dead(c);
1.103 markus 1381: return -1;
1.104 markus 1382: } else if (compat13) {
1.158 markus 1383: buffer_clear(&c->output);
1.41 markus 1384: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1385: debug2("channel %d: input draining.", c->self);
1.25 markus 1386: } else {
1.41 markus 1387: chan_read_failed(c);
1.25 markus 1388: }
1.41 markus 1389: return -1;
1390: }
1.143 deraadt 1391: if (c->input_filter != NULL) {
1.66 markus 1392: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1393: debug2("channel %d: filter stops", c->self);
1.65 markus 1394: chan_read_failed(c);
1395: }
1396: } else {
1397: buffer_append(&c->input, buf, len);
1398: }
1.41 markus 1399: }
1400: return 1;
1401: }
1.127 itojun 1402: static int
1.41 markus 1403: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1404: {
1.95 markus 1405: struct termios tio;
1.134 markus 1406: u_char *data;
1407: u_int dlen;
1.41 markus 1408: int len;
1.25 markus 1409:
1.41 markus 1410: /* Send buffered output data to the socket. */
1.118 markus 1411: if (c->wfd != -1 &&
1.41 markus 1412: FD_ISSET(c->wfd, writeset) &&
1413: buffer_len(&c->output) > 0) {
1.134 markus 1414: data = buffer_ptr(&c->output);
1415: dlen = buffer_len(&c->output);
1416: len = write(c->wfd, data, dlen);
1.53 markus 1417: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1418: return 1;
1.41 markus 1419: if (len <= 0) {
1.104 markus 1420: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1421: debug2("channel %d: not open", c->self);
1.113 markus 1422: chan_mark_dead(c);
1.104 markus 1423: return -1;
1424: } else if (compat13) {
1.158 markus 1425: buffer_clear(&c->output);
1.194 markus 1426: debug2("channel %d: input draining.", c->self);
1.41 markus 1427: c->type = SSH_CHANNEL_INPUT_DRAINING;
1428: } else {
1429: chan_write_failed(c);
1430: }
1431: return -1;
1.91 markus 1432: }
1.134 markus 1433: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1434: if (tcgetattr(c->wfd, &tio) == 0 &&
1435: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1436: /*
1437: * Simulate echo to reduce the impact of
1.96 markus 1438: * traffic analysis. We need to match the
1.95 markus 1439: * size of a SSH2_MSG_CHANNEL_DATA message
1440: * (4 byte channel id + data)
1.91 markus 1441: */
1.95 markus 1442: packet_send_ignore(4 + len);
1.91 markus 1443: packet_send();
1444: }
1.25 markus 1445: }
1.41 markus 1446: buffer_consume(&c->output, len);
1.44 markus 1447: if (compat20 && len > 0) {
1448: c->local_consumed += len;
1449: }
1450: }
1451: return 1;
1452: }
1.127 itojun 1453: static int
1.44 markus 1454: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1455: {
1.210.2.2! brad 1456: char buf[CHAN_RBUF];
1.44 markus 1457: int len;
1458:
1.45 markus 1459: /** XXX handle drain efd, too */
1.44 markus 1460: if (c->efd != -1) {
1461: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1462: FD_ISSET(c->efd, writeset) &&
1463: buffer_len(&c->extended) > 0) {
1464: len = write(c->efd, buffer_ptr(&c->extended),
1465: buffer_len(&c->extended));
1.70 markus 1466: debug2("channel %d: written %d to efd %d",
1.44 markus 1467: c->self, len, c->efd);
1.93 markus 1468: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1469: return 1;
1470: if (len <= 0) {
1471: debug2("channel %d: closing write-efd %d",
1472: c->self, c->efd);
1.132 markus 1473: channel_close_fd(&c->efd);
1.93 markus 1474: } else {
1.44 markus 1475: buffer_consume(&c->extended, len);
1476: c->local_consumed += len;
1477: }
1478: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1479: FD_ISSET(c->efd, readset)) {
1480: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1481: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1482: c->self, len, c->efd);
1.93 markus 1483: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1484: return 1;
1485: if (len <= 0) {
1486: debug2("channel %d: closing read-efd %d",
1.45 markus 1487: c->self, c->efd);
1.132 markus 1488: channel_close_fd(&c->efd);
1.93 markus 1489: } else {
1.44 markus 1490: buffer_append(&c->extended, buf, len);
1.93 markus 1491: }
1.44 markus 1492: }
1493: }
1494: return 1;
1495: }
1.127 itojun 1496: static int
1.204 djm 1497: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
1498: {
1499: char buf[16];
1500: int len;
1501:
1502: /* Monitor control fd to detect if the slave client exits */
1503: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1504: len = read(c->ctl_fd, buf, sizeof(buf));
1505: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1506: return 1;
1507: if (len <= 0) {
1508: debug2("channel %d: ctl read<=0", c->self);
1509: if (c->type != SSH_CHANNEL_OPEN) {
1510: debug2("channel %d: not open", c->self);
1511: chan_mark_dead(c);
1512: return -1;
1513: } else {
1514: chan_read_failed(c);
1515: chan_write_failed(c);
1516: }
1517: return -1;
1518: } else
1519: fatal("%s: unexpected data on ctl fd", __func__);
1520: }
1521: return 1;
1522: }
1523: static int
1.93 markus 1524: channel_check_window(Channel *c)
1.44 markus 1525: {
1.104 markus 1526: if (c->type == SSH_CHANNEL_OPEN &&
1527: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1528: c->local_window < c->local_window_max/2 &&
1529: c->local_consumed > 0) {
1530: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1531: packet_put_int(c->remote_id);
1532: packet_put_int(c->local_consumed);
1533: packet_send();
1.70 markus 1534: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1535: c->self, c->local_window,
1536: c->local_consumed);
1537: c->local_window += c->local_consumed;
1538: c->local_consumed = 0;
1.1 deraadt 1539: }
1.41 markus 1540: return 1;
1.1 deraadt 1541: }
1542:
1.127 itojun 1543: static void
1.157 markus 1544: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1545: {
1.137 markus 1546: if (c->delayed)
1547: return;
1.41 markus 1548: channel_handle_rfd(c, readset, writeset);
1549: channel_handle_wfd(c, readset, writeset);
1.157 markus 1550: if (!compat20)
1.137 markus 1551: return;
1.44 markus 1552: channel_handle_efd(c, readset, writeset);
1.204 djm 1553: channel_handle_ctl(c, readset, writeset);
1.93 markus 1554: channel_check_window(c);
1.44 markus 1555: }
1556:
1.127 itojun 1557: static void
1.41 markus 1558: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1559: {
1.41 markus 1560: int len;
1.180 deraadt 1561:
1.41 markus 1562: /* Send buffered output data to the socket. */
1563: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1564: len = write(c->sock, buffer_ptr(&c->output),
1565: buffer_len(&c->output));
1566: if (len <= 0)
1.158 markus 1567: buffer_clear(&c->output);
1.41 markus 1568: else
1569: buffer_consume(&c->output, len);
1570: }
1571: }
1.25 markus 1572:
1.127 itojun 1573: static void
1.44 markus 1574: channel_handler_init_20(void)
1575: {
1.157 markus 1576: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1577: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1578: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1579: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1580: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1581: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1582: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1583: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1584:
1.157 markus 1585: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1586: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1587: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1588: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1589: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1590: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1591: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1592: }
1593:
1.127 itojun 1594: static void
1.41 markus 1595: channel_handler_init_13(void)
1596: {
1597: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1598: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1599: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1600: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1601: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1602: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1603: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1604: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1605: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1606:
1.157 markus 1607: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1608: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1609: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1610: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1611: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1612: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1613: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1614: }
1.25 markus 1615:
1.127 itojun 1616: static void
1.41 markus 1617: channel_handler_init_15(void)
1618: {
1.157 markus 1619: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1620: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1621: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1622: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1623: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1624: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1625: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1626:
1.41 markus 1627: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1628: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1629: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1630: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1631: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1632: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1633: }
1.27 markus 1634:
1.127 itojun 1635: static void
1.41 markus 1636: channel_handler_init(void)
1637: {
1638: int i;
1.180 deraadt 1639:
1.148 deraadt 1640: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1641: channel_pre[i] = NULL;
1642: channel_post[i] = NULL;
1643: }
1.44 markus 1644: if (compat20)
1645: channel_handler_init_20();
1646: else if (compat13)
1.41 markus 1647: channel_handler_init_13();
1648: else
1649: channel_handler_init_15();
1650: }
1.25 markus 1651:
1.140 markus 1652: /* gc dead channels */
1653: static void
1654: channel_garbage_collect(Channel *c)
1655: {
1656: if (c == NULL)
1657: return;
1658: if (c->detach_user != NULL) {
1659: if (!chan_is_dead(c, 0))
1660: return;
1.194 markus 1661: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1662: c->detach_user(c->self, NULL);
1663: /* if we still have a callback */
1664: if (c->detach_user != NULL)
1665: return;
1.194 markus 1666: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1667: }
1668: if (!chan_is_dead(c, 1))
1669: return;
1.194 markus 1670: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1671: channel_free(c);
1672: }
1673:
1.127 itojun 1674: static void
1.41 markus 1675: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1676: {
1677: static int did_init = 0;
1.209 avsm 1678: u_int i;
1.41 markus 1679: Channel *c;
1.25 markus 1680:
1.41 markus 1681: if (!did_init) {
1682: channel_handler_init();
1683: did_init = 1;
1684: }
1685: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1686: c = channels[i];
1687: if (c == NULL)
1.41 markus 1688: continue;
1.118 markus 1689: if (ftab[c->type] != NULL)
1690: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1691: channel_garbage_collect(c);
1.1 deraadt 1692: }
1693: }
1694:
1.121 markus 1695: /*
1696: * Allocate/update select bitmasks and add any bits relevant to channels in
1697: * select bitmasks.
1698: */
1.49 markus 1699: void
1.100 markus 1700: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1701: u_int *nallocp, int rekeying)
1.41 markus 1702: {
1.209 avsm 1703: u_int n, sz;
1.84 markus 1704:
1705: n = MAX(*maxfdp, channel_max_fd);
1706:
1707: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1708: /* perhaps check sz < nalloc/2 and shrink? */
1709: if (*readsetp == NULL || sz > *nallocp) {
1710: *readsetp = xrealloc(*readsetp, sz);
1711: *writesetp = xrealloc(*writesetp, sz);
1712: *nallocp = sz;
1.84 markus 1713: }
1.132 markus 1714: *maxfdp = n;
1.84 markus 1715: memset(*readsetp, 0, sz);
1716: memset(*writesetp, 0, sz);
1717:
1.100 markus 1718: if (!rekeying)
1719: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1720: }
1721:
1.121 markus 1722: /*
1723: * After select, perform any appropriate operations for channels which have
1724: * events pending.
1725: */
1.49 markus 1726: void
1.41 markus 1727: channel_after_select(fd_set * readset, fd_set * writeset)
1728: {
1729: channel_handler(channel_post, readset, writeset);
1730: }
1731:
1.121 markus 1732:
1.84 markus 1733: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1734:
1.49 markus 1735: void
1.142 itojun 1736: channel_output_poll(void)
1.1 deraadt 1737: {
1.41 markus 1738: Channel *c;
1.209 avsm 1739: u_int i, len;
1.1 deraadt 1740:
1.25 markus 1741: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1742: c = channels[i];
1743: if (c == NULL)
1744: continue;
1.37 markus 1745:
1.121 markus 1746: /*
1747: * We are only interested in channels that can have buffered
1748: * incoming data.
1749: */
1.37 markus 1750: if (compat13) {
1.41 markus 1751: if (c->type != SSH_CHANNEL_OPEN &&
1752: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1753: continue;
1754: } else {
1.41 markus 1755: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1756: continue;
1757: }
1.46 markus 1758: if (compat20 &&
1759: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1760: /* XXX is this true? */
1.140 markus 1761: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1762: continue;
1763: }
1.25 markus 1764:
1765: /* Get the amount of buffered data for this channel. */
1.93 markus 1766: if ((c->istate == CHAN_INPUT_OPEN ||
1767: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1768: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1769: /*
1770: * Send some data for the other side over the secure
1771: * connection.
1772: */
1.44 markus 1773: if (compat20) {
1774: if (len > c->remote_window)
1775: len = c->remote_window;
1776: if (len > c->remote_maxpacket)
1777: len = c->remote_maxpacket;
1.25 markus 1778: } else {
1.44 markus 1779: if (packet_is_interactive()) {
1780: if (len > 1024)
1781: len = 512;
1782: } else {
1783: /* Keep the packets at reasonable size. */
1784: if (len > packet_get_maxsize()/2)
1785: len = packet_get_maxsize()/2;
1786: }
1.25 markus 1787: }
1.41 markus 1788: if (len > 0) {
1.44 markus 1789: packet_start(compat20 ?
1790: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1791: packet_put_int(c->remote_id);
1792: packet_put_string(buffer_ptr(&c->input), len);
1793: packet_send();
1794: buffer_consume(&c->input, len);
1795: c->remote_window -= len;
1796: }
1797: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1798: if (compat13)
1799: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1800: /*
1801: * input-buffer is empty and read-socket shutdown:
1.172 markus 1802: * tell peer, that we will not send more data: send IEOF.
1803: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1804: */
1.172 markus 1805: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.174 markus 1806: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1807: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1808: else
1809: chan_ibuf_empty(c);
1.25 markus 1810: }
1.44 markus 1811: /* Send extended data, i.e. stderr */
1812: if (compat20 &&
1.172 markus 1813: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1814: c->remote_window > 0 &&
1815: (len = buffer_len(&c->extended)) > 0 &&
1816: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1817: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1818: c->self, c->remote_window, buffer_len(&c->extended),
1819: c->extended_usage);
1.44 markus 1820: if (len > c->remote_window)
1821: len = c->remote_window;
1822: if (len > c->remote_maxpacket)
1823: len = c->remote_maxpacket;
1824: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1825: packet_put_int(c->remote_id);
1826: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1827: packet_put_string(buffer_ptr(&c->extended), len);
1828: packet_send();
1829: buffer_consume(&c->extended, len);
1830: c->remote_window -= len;
1.93 markus 1831: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1832: }
1.25 markus 1833: }
1.1 deraadt 1834: }
1835:
1.121 markus 1836:
1837: /* -- protocol input */
1.1 deraadt 1838:
1.49 markus 1839: void
1.154 markus 1840: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1841: {
1.37 markus 1842: int id;
1.25 markus 1843: char *data;
1.77 markus 1844: u_int data_len;
1.41 markus 1845: Channel *c;
1.25 markus 1846:
1847: /* Get the channel number and verify it. */
1.37 markus 1848: id = packet_get_int();
1.41 markus 1849: c = channel_lookup(id);
1850: if (c == NULL)
1.37 markus 1851: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1852:
1853: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1854: if (c->type != SSH_CHANNEL_OPEN &&
1855: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1856: return;
1857:
1.25 markus 1858: /* Get the data. */
1859: data = packet_get_string(&data_len);
1.200 markus 1860:
1861: /*
1862: * Ignore data for protocol > 1.3 if output end is no longer open.
1863: * For protocol 2 the sending side is reducing its window as it sends
1864: * data, so we must 'fake' consumption of the data in order to ensure
1865: * that window updates are sent back. Otherwise the connection might
1866: * deadlock.
1867: */
1868: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1869: if (compat20) {
1870: c->local_window -= data_len;
1871: c->local_consumed += data_len;
1872: }
1873: xfree(data);
1874: return;
1875: }
1.41 markus 1876:
1.143 deraadt 1877: if (compat20) {
1.44 markus 1878: if (data_len > c->local_maxpacket) {
1.188 itojun 1879: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1880: c->self, data_len, c->local_maxpacket);
1881: }
1882: if (data_len > c->local_window) {
1.188 itojun 1883: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1884: c->self, data_len, c->local_window);
1885: xfree(data);
1886: return;
1887: }
1888: c->local_window -= data_len;
1889: }
1.152 markus 1890: packet_check_eom();
1.41 markus 1891: buffer_append(&c->output, data, data_len);
1.25 markus 1892: xfree(data);
1.1 deraadt 1893: }
1.121 markus 1894:
1.49 markus 1895: void
1.154 markus 1896: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1897: {
1898: int id;
1899: char *data;
1.177 markus 1900: u_int data_len, tcode;
1.44 markus 1901: Channel *c;
1902:
1903: /* Get the channel number and verify it. */
1904: id = packet_get_int();
1905: c = channel_lookup(id);
1906:
1907: if (c == NULL)
1908: packet_disconnect("Received extended_data for bad channel %d.", id);
1909: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 1910: logit("channel %d: ext data for non open", id);
1.44 markus 1911: return;
1.172 markus 1912: }
1913: if (c->flags & CHAN_EOF_RCVD) {
1914: if (datafellows & SSH_BUG_EXTEOF)
1915: debug("channel %d: accepting ext data after eof", id);
1916: else
1917: packet_disconnect("Received extended_data after EOF "
1918: "on channel %d.", id);
1.44 markus 1919: }
1920: tcode = packet_get_int();
1921: if (c->efd == -1 ||
1922: c->extended_usage != CHAN_EXTENDED_WRITE ||
1923: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 1924: logit("channel %d: bad ext data", c->self);
1.44 markus 1925: return;
1926: }
1927: data = packet_get_string(&data_len);
1.152 markus 1928: packet_check_eom();
1.44 markus 1929: if (data_len > c->local_window) {
1.188 itojun 1930: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 1931: c->self, data_len, c->local_window);
1932: xfree(data);
1933: return;
1934: }
1.70 markus 1935: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1936: c->local_window -= data_len;
1937: buffer_append(&c->extended, data, data_len);
1938: xfree(data);
1939: }
1940:
1.49 markus 1941: void
1.154 markus 1942: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1943: {
1944: int id;
1945: Channel *c;
1946:
1947: id = packet_get_int();
1.152 markus 1948: packet_check_eom();
1.41 markus 1949: c = channel_lookup(id);
1950: if (c == NULL)
1951: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1952: chan_rcvd_ieof(c);
1.133 markus 1953:
1954: /* XXX force input close */
1.156 markus 1955: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1956: debug("channel %d: FORCE input drain", c->self);
1957: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1958: if (buffer_len(&c->input) == 0)
1959: chan_ibuf_empty(c);
1.133 markus 1960: }
1961:
1.41 markus 1962: }
1.1 deraadt 1963:
1.49 markus 1964: void
1.154 markus 1965: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1966: {
1.41 markus 1967: int id;
1968: Channel *c;
1.1 deraadt 1969:
1.41 markus 1970: id = packet_get_int();
1.152 markus 1971: packet_check_eom();
1.41 markus 1972: c = channel_lookup(id);
1973: if (c == NULL)
1974: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1975:
1976: /*
1977: * Send a confirmation that we have closed the channel and no more
1978: * data is coming for it.
1979: */
1.25 markus 1980: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1981: packet_put_int(c->remote_id);
1.25 markus 1982: packet_send();
1983:
1.27 markus 1984: /*
1985: * If the channel is in closed state, we have sent a close request,
1986: * and the other side will eventually respond with a confirmation.
1987: * Thus, we cannot free the channel here, because then there would be
1988: * no-one to receive the confirmation. The channel gets freed when
1989: * the confirmation arrives.
1990: */
1.41 markus 1991: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1992: /*
1993: * Not a closed channel - mark it as draining, which will
1994: * cause it to be freed later.
1995: */
1.158 markus 1996: buffer_clear(&c->input);
1.41 markus 1997: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1998: }
1.1 deraadt 1999: }
2000:
1.41 markus 2001: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 2002: void
1.154 markus 2003: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2004: {
2005: int id = packet_get_int();
2006: Channel *c = channel_lookup(id);
1.151 markus 2007:
1.152 markus 2008: packet_check_eom();
1.41 markus 2009: if (c == NULL)
2010: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2011: chan_rcvd_oclose(c);
2012: }
1.1 deraadt 2013:
1.49 markus 2014: void
1.154 markus 2015: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2016: {
1.41 markus 2017: int id = packet_get_int();
2018: Channel *c = channel_lookup(id);
1.1 deraadt 2019:
1.152 markus 2020: packet_check_eom();
1.41 markus 2021: if (c == NULL)
2022: packet_disconnect("Received close confirmation for "
2023: "out-of-range channel %d.", id);
2024: if (c->type != SSH_CHANNEL_CLOSED)
2025: packet_disconnect("Received close confirmation for "
2026: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2027: channel_free(c);
1.1 deraadt 2028: }
2029:
1.49 markus 2030: void
1.154 markus 2031: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2032: {
1.41 markus 2033: int id, remote_id;
2034: Channel *c;
1.1 deraadt 2035:
1.41 markus 2036: id = packet_get_int();
2037: c = channel_lookup(id);
1.25 markus 2038:
1.41 markus 2039: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2040: packet_disconnect("Received open confirmation for "
2041: "non-opening channel %d.", id);
2042: remote_id = packet_get_int();
1.27 markus 2043: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2044: c->remote_id = remote_id;
2045: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2046:
2047: if (compat20) {
2048: c->remote_window = packet_get_int();
2049: c->remote_maxpacket = packet_get_int();
1.165 markus 2050: if (c->confirm) {
1.70 markus 2051: debug2("callback start");
1.204 djm 2052: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2053: debug2("callback done");
1.44 markus 2054: }
1.194 markus 2055: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2056: c->remote_window, c->remote_maxpacket);
2057: }
1.152 markus 2058: packet_check_eom();
1.1 deraadt 2059: }
2060:
1.127 itojun 2061: static char *
1.114 markus 2062: reason2txt(int reason)
2063: {
1.143 deraadt 2064: switch (reason) {
1.114 markus 2065: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2066: return "administratively prohibited";
2067: case SSH2_OPEN_CONNECT_FAILED:
2068: return "connect failed";
2069: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2070: return "unknown channel type";
2071: case SSH2_OPEN_RESOURCE_SHORTAGE:
2072: return "resource shortage";
2073: }
1.117 stevesk 2074: return "unknown reason";
1.114 markus 2075: }
2076:
1.49 markus 2077: void
1.154 markus 2078: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2079: {
1.86 markus 2080: int id, reason;
2081: char *msg = NULL, *lang = NULL;
1.41 markus 2082: Channel *c;
2083:
2084: id = packet_get_int();
2085: c = channel_lookup(id);
1.25 markus 2086:
1.41 markus 2087: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2088: packet_disconnect("Received open failure for "
2089: "non-opening channel %d.", id);
1.44 markus 2090: if (compat20) {
1.86 markus 2091: reason = packet_get_int();
1.110 markus 2092: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2093: msg = packet_get_string(NULL);
2094: lang = packet_get_string(NULL);
2095: }
1.188 itojun 2096: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2097: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2098: if (msg != NULL)
2099: xfree(msg);
2100: if (lang != NULL)
2101: xfree(lang);
1.44 markus 2102: }
1.152 markus 2103: packet_check_eom();
1.25 markus 2104: /* Free the channel. This will also close the socket. */
1.113 markus 2105: channel_free(c);
1.44 markus 2106: }
2107:
1.121 markus 2108: void
1.154 markus 2109: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2110: {
2111: Channel *c;
1.178 markus 2112: int id;
2113: u_int adjust;
1.121 markus 2114:
2115: if (!compat20)
2116: return;
2117:
2118: /* Get the channel number and verify it. */
2119: id = packet_get_int();
2120: c = channel_lookup(id);
1.1 deraadt 2121:
1.121 markus 2122: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2123: logit("Received window adjust for "
1.121 markus 2124: "non-open channel %d.", id);
2125: return;
2126: }
2127: adjust = packet_get_int();
1.152 markus 2128: packet_check_eom();
1.178 markus 2129: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2130: c->remote_window += adjust;
2131: }
1.1 deraadt 2132:
1.121 markus 2133: void
1.154 markus 2134: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2135: {
1.121 markus 2136: Channel *c = NULL;
2137: u_short host_port;
2138: char *host, *originator_string;
2139: int remote_id, sock = -1;
2140:
2141: remote_id = packet_get_int();
2142: host = packet_get_string(NULL);
2143: host_port = packet_get_int();
1.25 markus 2144:
1.121 markus 2145: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2146: originator_string = packet_get_string(NULL);
2147: } else {
2148: originator_string = xstrdup("unknown (remote did not supply name)");
2149: }
1.152 markus 2150: packet_check_eom();
1.121 markus 2151: sock = channel_connect_to(host, host_port);
2152: if (sock != -1) {
2153: c = channel_new("connected socket",
2154: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2155: originator_string, 1);
1.167 markus 2156: c->remote_id = remote_id;
1.25 markus 2157: }
1.190 markus 2158: xfree(originator_string);
1.121 markus 2159: if (c == NULL) {
2160: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2161: packet_put_int(remote_id);
2162: packet_send();
2163: }
2164: xfree(host);
1.1 deraadt 2165: }
2166:
1.121 markus 2167:
2168: /* -- tcp forwarding */
1.135 markus 2169:
2170: void
2171: channel_set_af(int af)
2172: {
2173: IPv4or6 = af;
2174: }
1.121 markus 2175:
1.160 markus 2176: static int
2177: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2178: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2179: {
1.113 markus 2180: Channel *c;
1.210.2.1 brad 2181: int sock, r, success = 0, on = 1, wildcard = 0, is_client;
1.35 markus 2182: struct addrinfo hints, *ai, *aitop;
1.210.2.1 brad 2183: const char *host, *addr;
1.35 markus 2184: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2185:
1.160 markus 2186: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2187: listen_addr : host_to_connect;
1.210.2.1 brad 2188: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2189:
1.160 markus 2190: if (host == NULL) {
2191: error("No forward host name.");
2192: return success;
1.73 markus 2193: }
1.113 markus 2194: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2195: error("Forward host name too long.");
2196: return success;
2197: }
1.25 markus 2198:
1.28 markus 2199: /*
1.210.2.1 brad 2200: * Determine whether or not a port forward listens to loopback,
1.210.2.2! brad 2201: * specified address or wildcard. On the client, a specified bind
! 2202: * address will always override gateway_ports. On the server, a
! 2203: * gateway_ports of 1 (``yes'') will override the client's
! 2204: * specification and force a wildcard bind, whereas a value of 2
! 2205: * (``clientspecified'') will bind to whatever address the client
1.210.2.1 brad 2206: * asked for.
2207: *
2208: * Special-case listen_addrs are:
2209: *
2210: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2211: * "" (empty string), "*" -> wildcard v4/v6
2212: * "localhost" -> loopback v4/v6
2213: */
2214: addr = NULL;
2215: if (listen_addr == NULL) {
2216: /* No address specified: default to gateway_ports setting */
2217: if (gateway_ports)
2218: wildcard = 1;
2219: } else if (gateway_ports || is_client) {
2220: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2221: strcmp(listen_addr, "0.0.0.0") == 0) ||
2222: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2223: (!is_client && gateway_ports == 1))
2224: wildcard = 1;
2225: else if (strcmp(listen_addr, "localhost") != 0)
2226: addr = listen_addr;
2227: }
2228:
2229: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2230: type, wildcard, (addr == NULL) ? "NULL" : addr);
2231:
2232: /*
1.35 markus 2233: * getaddrinfo returns a loopback address if the hostname is
2234: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2235: */
1.35 markus 2236: memset(&hints, 0, sizeof(hints));
2237: hints.ai_family = IPv4or6;
1.210.2.1 brad 2238: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2239: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2240: snprintf(strport, sizeof strport, "%d", listen_port);
1.210.2.1 brad 2241: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2242: if (addr == NULL) {
2243: /* This really shouldn't happen */
2244: packet_disconnect("getaddrinfo: fatal error: %s",
2245: gai_strerror(r));
2246: } else {
2247: verbose("channel_setup_fwd_listener: "
2248: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2249: packet_send_debug("channel_setup_fwd_listener: "
2250: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2251: }
2252: aitop = NULL;
2253: }
1.35 markus 2254:
2255: for (ai = aitop; ai; ai = ai->ai_next) {
2256: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2257: continue;
2258: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2259: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2260: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2261: continue;
2262: }
2263: /* Create a port to listen for the host. */
1.189 markus 2264: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2265: if (sock < 0) {
2266: /* this is no error since kernel may not support ipv6 */
2267: verbose("socket: %.100s", strerror(errno));
2268: continue;
2269: }
2270: /*
1.182 stevesk 2271: * Set socket options.
2272: * Allow local port reuse in TIME_WAIT.
1.35 markus 2273: */
1.182 stevesk 2274: if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
2275: sizeof(on)) == -1)
2276: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
2277:
1.35 markus 2278: debug("Local forwarding listening on %s port %s.", ntop, strport);
2279:
2280: /* Bind the socket to the address. */
2281: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2282: /* address can be in use ipv6 address is already bound */
2283: verbose("bind: %.100s", strerror(errno));
2284: close(sock);
2285: continue;
2286: }
2287: /* Start listening for connections on the socket. */
1.199 markus 2288: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2289: error("listen: %.100s", strerror(errno));
2290: close(sock);
2291: continue;
2292: }
2293: /* Allocate a channel number for the socket. */
1.121 markus 2294: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2295: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2296: 0, "port listener", 1);
1.113 markus 2297: strlcpy(c->path, host, sizeof(c->path));
2298: c->host_port = port_to_connect;
2299: c->listening_port = listen_port;
1.35 markus 2300: success = 1;
2301: }
2302: if (success == 0)
1.160 markus 2303: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2304: listen_port);
1.35 markus 2305: freeaddrinfo(aitop);
1.87 markus 2306: return success;
1.25 markus 2307: }
1.1 deraadt 2308:
1.202 djm 2309: int
2310: channel_cancel_rport_listener(const char *host, u_short port)
2311: {
1.209 avsm 2312: u_int i;
2313: int found = 0;
1.202 djm 2314:
1.210.2.2! brad 2315: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2316: Channel *c = channels[i];
2317:
2318: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2319: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2320: c->listening_port == port) {
1.210 djm 2321: debug2("%s: close channel %d", __func__, i);
1.202 djm 2322: channel_free(c);
2323: found = 1;
2324: }
2325: }
2326:
2327: return (found);
2328: }
2329:
1.160 markus 2330: /* protocol local port fwd, used by ssh (and sshd in v1) */
2331: int
1.210.2.1 brad 2332: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2333: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2334: {
2335: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.210.2.1 brad 2336: listen_host, listen_port, host_to_connect, port_to_connect,
2337: gateway_ports);
1.160 markus 2338: }
2339:
2340: /* protocol v2 remote port fwd, used by sshd */
2341: int
2342: channel_setup_remote_fwd_listener(const char *listen_address,
2343: u_short listen_port, int gateway_ports)
2344: {
2345: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2346: listen_address, listen_port, NULL, 0, gateway_ports);
2347: }
2348:
1.27 markus 2349: /*
2350: * Initiate forwarding of connections to port "port" on remote host through
2351: * the secure channel to host:port from local side.
2352: */
1.1 deraadt 2353:
1.49 markus 2354: void
1.210.2.1 brad 2355: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2356: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2357: {
1.153 markus 2358: int type, success = 0;
1.73 markus 2359:
1.25 markus 2360: /* Record locally that connection to this host/port is permitted. */
2361: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2362: fatal("channel_request_remote_forwarding: too many forwards");
2363:
2364: /* Send the forward request to the remote side. */
1.44 markus 2365: if (compat20) {
1.210.2.1 brad 2366: const char *address_to_bind;
2367: if (listen_host == NULL)
2368: address_to_bind = "localhost";
2369: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2370: address_to_bind = "";
2371: else
2372: address_to_bind = listen_host;
2373:
1.44 markus 2374: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2375: packet_put_cstring("tcpip-forward");
1.173 markus 2376: packet_put_char(1); /* boolean: want reply */
1.44 markus 2377: packet_put_cstring(address_to_bind);
2378: packet_put_int(listen_port);
1.73 markus 2379: packet_send();
2380: packet_write_wait();
2381: /* Assume that server accepts the request */
2382: success = 1;
1.44 markus 2383: } else {
2384: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2385: packet_put_int(listen_port);
2386: packet_put_cstring(host_to_connect);
1.44 markus 2387: packet_put_int(port_to_connect);
2388: packet_send();
2389: packet_write_wait();
1.73 markus 2390:
2391: /* Wait for response from the remote side. */
1.153 markus 2392: type = packet_read();
1.73 markus 2393: switch (type) {
2394: case SSH_SMSG_SUCCESS:
2395: success = 1;
2396: break;
2397: case SSH_SMSG_FAILURE:
1.188 itojun 2398: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2399: break;
2400: default:
2401: /* Unknown packet */
2402: packet_disconnect("Protocol error for port forward request:"
2403: "received packet type %d.", type);
2404: }
2405: }
2406: if (success) {
2407: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2408: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2409: permitted_opens[num_permitted_opens].listen_port = listen_port;
2410: num_permitted_opens++;
1.44 markus 2411: }
1.1 deraadt 2412: }
2413:
1.27 markus 2414: /*
1.208 deraadt 2415: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2416: * local side.
2417: */
2418: void
1.210.2.1 brad 2419: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2420: {
2421: int i;
2422:
2423: if (!compat20)
2424: return;
2425:
2426: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2427: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2428: permitted_opens[i].listen_port == port)
2429: break;
2430: }
2431: if (i >= num_permitted_opens) {
2432: debug("%s: requested forward not found", __func__);
2433: return;
2434: }
2435: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2436: packet_put_cstring("cancel-tcpip-forward");
2437: packet_put_char(0);
1.210.2.1 brad 2438: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2439: packet_put_int(port);
2440: packet_send();
2441:
2442: permitted_opens[i].listen_port = 0;
2443: permitted_opens[i].port_to_connect = 0;
2444: free(permitted_opens[i].host_to_connect);
2445: permitted_opens[i].host_to_connect = NULL;
2446: }
2447:
2448: /*
1.27 markus 2449: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2450: * listening for the port, and sends back a success reply (or disconnect
2451: * message if there was an error). This never returns if there was an error.
2452: */
1.1 deraadt 2453:
1.49 markus 2454: void
1.56 markus 2455: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2456: {
1.31 markus 2457: u_short port, host_port;
1.25 markus 2458: char *hostname;
1.1 deraadt 2459:
1.25 markus 2460: /* Get arguments from the packet. */
2461: port = packet_get_int();
2462: hostname = packet_get_string(NULL);
2463: host_port = packet_get_int();
2464:
1.27 markus 2465: /*
2466: * Check that an unprivileged user is not trying to forward a
2467: * privileged port.
2468: */
1.25 markus 2469: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2470: packet_disconnect(
2471: "Requested forwarding of port %d but user is not root.",
2472: port);
2473: if (host_port == 0)
2474: packet_disconnect("Dynamic forwarding denied.");
2475:
1.73 markus 2476: /* Initiate forwarding */
1.210.2.1 brad 2477: channel_setup_local_fwd_listener(NULL, port, hostname,
2478: host_port, gateway_ports);
1.25 markus 2479:
2480: /* Free the argument string. */
2481: xfree(hostname);
1.1 deraadt 2482: }
2483:
1.99 markus 2484: /*
2485: * Permits opening to any host/port if permitted_opens[] is empty. This is
2486: * usually called by the server, because the user could connect to any port
2487: * anyway, and the server has no way to know but to trust the client anyway.
2488: */
2489: void
1.142 itojun 2490: channel_permit_all_opens(void)
1.99 markus 2491: {
2492: if (num_permitted_opens == 0)
2493: all_opens_permitted = 1;
2494: }
2495:
1.101 markus 2496: void
1.99 markus 2497: channel_add_permitted_opens(char *host, int port)
2498: {
2499: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2500: fatal("channel_request_remote_forwarding: too many forwards");
2501: debug("allow port forwarding to host %s port %d", host, port);
2502:
2503: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2504: permitted_opens[num_permitted_opens].port_to_connect = port;
2505: num_permitted_opens++;
2506:
2507: all_opens_permitted = 0;
2508: }
2509:
1.101 markus 2510: void
1.99 markus 2511: channel_clear_permitted_opens(void)
2512: {
2513: int i;
2514:
2515: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2516: if (permitted_opens[i].host_to_connect != NULL)
2517: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2518: num_permitted_opens = 0;
2519:
2520: }
2521:
2522:
2523: /* return socket to remote host, port */
1.127 itojun 2524: static int
1.99 markus 2525: connect_to(const char *host, u_short port)
1.41 markus 2526: {
2527: struct addrinfo hints, *ai, *aitop;
2528: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2529: int gaierr;
2530: int sock = -1;
2531:
2532: memset(&hints, 0, sizeof(hints));
2533: hints.ai_family = IPv4or6;
2534: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2535: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2536: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2537: error("connect_to %.100s: unknown host (%s)", host,
2538: gai_strerror(gaierr));
1.41 markus 2539: return -1;
2540: }
2541: for (ai = aitop; ai; ai = ai->ai_next) {
2542: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2543: continue;
2544: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2545: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2546: error("connect_to: getnameinfo failed");
1.41 markus 2547: continue;
2548: }
1.189 markus 2549: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2550: if (sock < 0) {
1.186 djm 2551: if (ai->ai_next == NULL)
2552: error("socket: %.100s", strerror(errno));
2553: else
2554: verbose("socket: %.100s", strerror(errno));
1.41 markus 2555: continue;
2556: }
1.205 djm 2557: if (set_nonblock(sock) == -1)
2558: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2559: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2560: errno != EINPROGRESS) {
1.99 markus 2561: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2562: strerror(errno));
2563: close(sock);
1.89 stevesk 2564: continue; /* fail -- try next */
1.41 markus 2565: }
2566: break; /* success */
2567:
2568: }
2569: freeaddrinfo(aitop);
2570: if (!ai) {
1.99 markus 2571: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2572: return -1;
2573: }
2574: /* success */
1.169 stevesk 2575: set_nodelay(sock);
1.41 markus 2576: return sock;
2577: }
1.99 markus 2578:
1.73 markus 2579: int
1.130 stevesk 2580: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2581: {
2582: int i;
1.99 markus 2583:
1.73 markus 2584: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2585: if (permitted_opens[i].host_to_connect != NULL &&
2586: permitted_opens[i].listen_port == listen_port)
1.99 markus 2587: return connect_to(
1.73 markus 2588: permitted_opens[i].host_to_connect,
2589: permitted_opens[i].port_to_connect);
1.74 markus 2590: error("WARNING: Server requests forwarding for unknown listen_port %d",
2591: listen_port);
1.73 markus 2592: return -1;
2593: }
2594:
1.99 markus 2595: /* Check if connecting to that port is permitted and connect. */
2596: int
2597: channel_connect_to(const char *host, u_short port)
2598: {
2599: int i, permit;
2600:
2601: permit = all_opens_permitted;
2602: if (!permit) {
2603: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2604: if (permitted_opens[i].host_to_connect != NULL &&
2605: permitted_opens[i].port_to_connect == port &&
1.99 markus 2606: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2607: permit = 1;
2608:
2609: }
2610: if (!permit) {
1.188 itojun 2611: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2612: "but the request was denied.", host, port);
2613: return -1;
2614: }
2615: return connect_to(host, port);
1.204 djm 2616: }
2617:
2618: void
2619: channel_send_window_changes(void)
2620: {
1.209 avsm 2621: u_int i;
1.204 djm 2622: struct winsize ws;
2623:
2624: for (i = 0; i < channels_alloc; i++) {
1.210.2.2! brad 2625: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2626: channels[i]->type != SSH_CHANNEL_OPEN)
2627: continue;
2628: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2629: continue;
2630: channel_request_start(i, "window-change", 0);
2631: packet_put_int(ws.ws_col);
2632: packet_put_int(ws.ws_row);
2633: packet_put_int(ws.ws_xpixel);
2634: packet_put_int(ws.ws_ypixel);
2635: packet_send();
2636: }
1.99 markus 2637: }
2638:
1.121 markus 2639: /* -- X11 forwarding */
1.1 deraadt 2640:
1.27 markus 2641: /*
2642: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2643: * Returns 0 and a suitable display number for the DISPLAY variable
2644: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2645: */
1.141 stevesk 2646: int
1.163 stevesk 2647: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.176 deraadt 2648: int single_connection, u_int *display_numberp)
1.1 deraadt 2649: {
1.149 markus 2650: Channel *nc = NULL;
1.31 markus 2651: int display_number, sock;
2652: u_short port;
1.35 markus 2653: struct addrinfo hints, *ai, *aitop;
2654: char strport[NI_MAXSERV];
2655: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2656:
1.33 markus 2657: for (display_number = x11_display_offset;
1.148 deraadt 2658: display_number < MAX_DISPLAYS;
2659: display_number++) {
1.25 markus 2660: port = 6000 + display_number;
1.35 markus 2661: memset(&hints, 0, sizeof(hints));
2662: hints.ai_family = IPv4or6;
1.163 stevesk 2663: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2664: hints.ai_socktype = SOCK_STREAM;
2665: snprintf(strport, sizeof strport, "%d", port);
2666: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2667: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2668: return -1;
1.25 markus 2669: }
1.35 markus 2670: for (ai = aitop; ai; ai = ai->ai_next) {
2671: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2672: continue;
1.189 markus 2673: sock = socket(ai->ai_family, ai->ai_socktype,
2674: ai->ai_protocol);
1.35 markus 2675: if (sock < 0) {
2676: error("socket: %.100s", strerror(errno));
1.203 markus 2677: freeaddrinfo(aitop);
1.141 stevesk 2678: return -1;
1.35 markus 2679: }
2680: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2681: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2682: close(sock);
1.183 itojun 2683:
2684: if (ai->ai_next)
2685: continue;
2686:
1.35 markus 2687: for (n = 0; n < num_socks; n++) {
2688: close(socks[n]);
2689: }
2690: num_socks = 0;
2691: break;
2692: }
2693: socks[num_socks++] = sock;
2694: if (num_socks == NUM_SOCKS)
2695: break;
1.25 markus 2696: }
1.83 stevesk 2697: freeaddrinfo(aitop);
1.35 markus 2698: if (num_socks > 0)
2699: break;
1.25 markus 2700: }
2701: if (display_number >= MAX_DISPLAYS) {
2702: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2703: return -1;
1.25 markus 2704: }
2705: /* Start listening for connections on the socket. */
1.35 markus 2706: for (n = 0; n < num_socks; n++) {
2707: sock = socks[n];
1.199 markus 2708: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2709: error("listen: %.100s", strerror(errno));
2710: close(sock);
1.141 stevesk 2711: return -1;
1.35 markus 2712: }
1.25 markus 2713: }
1.35 markus 2714:
2715: /* Allocate a channel for each socket. */
2716: for (n = 0; n < num_socks; n++) {
2717: sock = socks[n];
1.149 markus 2718: nc = channel_new("x11 listener",
1.51 markus 2719: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2720: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2721: 0, "X11 inet listener", 1);
1.167 markus 2722: nc->single_connection = single_connection;
1.35 markus 2723: }
1.1 deraadt 2724:
1.141 stevesk 2725: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2726: *display_numberp = display_number;
2727: return (0);
1.1 deraadt 2728: }
2729:
1.127 itojun 2730: static int
1.77 markus 2731: connect_local_xsocket(u_int dnr)
1.1 deraadt 2732: {
1.25 markus 2733: int sock;
2734: struct sockaddr_un addr;
2735:
1.147 stevesk 2736: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2737: if (sock < 0)
2738: error("socket: %.100s", strerror(errno));
2739: memset(&addr, 0, sizeof(addr));
2740: addr.sun_family = AF_UNIX;
2741: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2742: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2743: return sock;
2744: close(sock);
1.25 markus 2745: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2746: return -1;
1.1 deraadt 2747: }
2748:
1.51 markus 2749: int
2750: x11_connect_display(void)
1.1 deraadt 2751: {
1.162 stevesk 2752: int display_number, sock = 0;
1.25 markus 2753: const char *display;
1.51 markus 2754: char buf[1024], *cp;
1.35 markus 2755: struct addrinfo hints, *ai, *aitop;
2756: char strport[NI_MAXSERV];
2757: int gaierr;
1.25 markus 2758:
2759: /* Try to open a socket for the local X server. */
2760: display = getenv("DISPLAY");
2761: if (!display) {
2762: error("DISPLAY not set.");
1.51 markus 2763: return -1;
1.25 markus 2764: }
1.27 markus 2765: /*
2766: * Now we decode the value of the DISPLAY variable and make a
2767: * connection to the real X server.
2768: */
2769:
2770: /*
2771: * Check if it is a unix domain socket. Unix domain displays are in
2772: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2773: */
1.25 markus 2774: if (strncmp(display, "unix:", 5) == 0 ||
2775: display[0] == ':') {
2776: /* Connect to the unix domain socket. */
2777: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2778: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2779: display);
1.51 markus 2780: return -1;
1.25 markus 2781: }
2782: /* Create a socket. */
2783: sock = connect_local_xsocket(display_number);
2784: if (sock < 0)
1.51 markus 2785: return -1;
1.25 markus 2786:
2787: /* OK, we now have a connection to the display. */
1.51 markus 2788: return sock;
1.25 markus 2789: }
1.27 markus 2790: /*
2791: * Connect to an inet socket. The DISPLAY value is supposedly
2792: * hostname:d[.s], where hostname may also be numeric IP address.
2793: */
1.145 stevesk 2794: strlcpy(buf, display, sizeof(buf));
1.25 markus 2795: cp = strchr(buf, ':');
2796: if (!cp) {
2797: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2798: return -1;
1.25 markus 2799: }
2800: *cp = 0;
1.27 markus 2801: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2802: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2803: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2804: display);
1.51 markus 2805: return -1;
1.25 markus 2806: }
1.35 markus 2807:
2808: /* Look up the host address */
2809: memset(&hints, 0, sizeof(hints));
2810: hints.ai_family = IPv4or6;
2811: hints.ai_socktype = SOCK_STREAM;
2812: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2813: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2814: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2815: return -1;
1.25 markus 2816: }
1.35 markus 2817: for (ai = aitop; ai; ai = ai->ai_next) {
2818: /* Create a socket. */
1.189 markus 2819: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2820: if (sock < 0) {
1.194 markus 2821: debug2("socket: %.100s", strerror(errno));
1.41 markus 2822: continue;
2823: }
2824: /* Connect it to the display. */
2825: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2826: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2827: 6000 + display_number, strerror(errno));
2828: close(sock);
2829: continue;
2830: }
2831: /* Success */
2832: break;
1.35 markus 2833: }
2834: freeaddrinfo(aitop);
2835: if (!ai) {
1.49 markus 2836: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2837: strerror(errno));
1.51 markus 2838: return -1;
1.25 markus 2839: }
1.162 stevesk 2840: set_nodelay(sock);
1.51 markus 2841: return sock;
2842: }
2843:
2844: /*
2845: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2846: * the remote channel number. We should do whatever we want, and respond
2847: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2848: */
2849:
2850: void
1.154 markus 2851: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2852: {
1.113 markus 2853: Channel *c = NULL;
2854: int remote_id, sock = 0;
1.51 markus 2855: char *remote_host;
1.25 markus 2856:
1.113 markus 2857: debug("Received X11 open request.");
1.51 markus 2858:
1.113 markus 2859: remote_id = packet_get_int();
1.121 markus 2860:
2861: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2862: remote_host = packet_get_string(NULL);
1.51 markus 2863: } else {
2864: remote_host = xstrdup("unknown (remote did not supply name)");
2865: }
1.152 markus 2866: packet_check_eom();
1.25 markus 2867:
1.51 markus 2868: /* Obtain a connection to the real X display. */
2869: sock = x11_connect_display();
1.113 markus 2870: if (sock != -1) {
2871: /* Allocate a channel for this connection. */
2872: c = channel_new("connected x11 socket",
2873: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2874: remote_host, 1);
1.167 markus 2875: c->remote_id = remote_id;
2876: c->force_drain = 1;
1.113 markus 2877: }
1.190 markus 2878: xfree(remote_host);
1.113 markus 2879: if (c == NULL) {
1.51 markus 2880: /* Send refusal to the remote host. */
2881: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2882: packet_put_int(remote_id);
1.51 markus 2883: } else {
2884: /* Send a confirmation to the remote host. */
2885: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2886: packet_put_int(remote_id);
2887: packet_put_int(c->self);
1.51 markus 2888: }
1.113 markus 2889: packet_send();
1.72 markus 2890: }
2891:
2892: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2893: void
1.154 markus 2894: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2895: {
2896: int rchan = packet_get_int();
1.180 deraadt 2897:
1.143 deraadt 2898: switch (type) {
1.72 markus 2899: case SSH_SMSG_AGENT_OPEN:
2900: error("Warning: ssh server tried agent forwarding.");
2901: break;
2902: case SSH_SMSG_X11_OPEN:
2903: error("Warning: ssh server tried X11 forwarding.");
2904: break;
2905: default:
1.154 markus 2906: error("deny_input_open: type %d", type);
1.72 markus 2907: break;
2908: }
2909: error("Warning: this is probably a break in attempt by a malicious server.");
2910: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2911: packet_put_int(rchan);
2912: packet_send();
1.1 deraadt 2913: }
2914:
1.27 markus 2915: /*
2916: * Requests forwarding of X11 connections, generates fake authentication
2917: * data, and enables authentication spoofing.
1.121 markus 2918: * This should be called in the client only.
1.27 markus 2919: */
1.49 markus 2920: void
1.51 markus 2921: x11_request_forwarding_with_spoofing(int client_session_id,
2922: const char *proto, const char *data)
1.1 deraadt 2923: {
1.77 markus 2924: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2925: u_int i, value, len;
1.25 markus 2926: char *new_data;
2927: int screen_number;
2928: const char *cp;
1.207 avsm 2929: u_int32_t rnd = 0;
1.25 markus 2930:
2931: cp = getenv("DISPLAY");
2932: if (cp)
2933: cp = strchr(cp, ':');
2934: if (cp)
2935: cp = strchr(cp, '.');
2936: if (cp)
2937: screen_number = atoi(cp + 1);
2938: else
2939: screen_number = 0;
2940:
2941: /* Save protocol name. */
2942: x11_saved_proto = xstrdup(proto);
2943:
1.27 markus 2944: /*
2945: * Extract real authentication data and generate fake data of the
2946: * same length.
2947: */
1.25 markus 2948: x11_saved_data = xmalloc(data_len);
2949: x11_fake_data = xmalloc(data_len);
2950: for (i = 0; i < data_len; i++) {
2951: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2952: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2953: if (i % 4 == 0)
1.207 avsm 2954: rnd = arc4random();
1.25 markus 2955: x11_saved_data[i] = value;
1.207 avsm 2956: x11_fake_data[i] = rnd & 0xff;
2957: rnd >>= 8;
1.25 markus 2958: }
2959: x11_saved_data_len = data_len;
2960: x11_fake_data_len = data_len;
2961:
2962: /* Convert the fake data into hex. */
1.90 markus 2963: len = 2 * data_len + 1;
2964: new_data = xmalloc(len);
1.25 markus 2965: for (i = 0; i < data_len; i++)
1.90 markus 2966: snprintf(new_data + 2 * i, len - 2 * i,
2967: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2968:
2969: /* Send the request packet. */
1.51 markus 2970: if (compat20) {
2971: channel_request_start(client_session_id, "x11-req", 0);
2972: packet_put_char(0); /* XXX bool single connection */
2973: } else {
2974: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2975: }
2976: packet_put_cstring(proto);
2977: packet_put_cstring(new_data);
1.25 markus 2978: packet_put_int(screen_number);
2979: packet_send();
2980: packet_write_wait();
2981: xfree(new_data);
1.1 deraadt 2982: }
2983:
1.121 markus 2984:
2985: /* -- agent forwarding */
2986:
1.1 deraadt 2987: /* Sends a message to the server to request authentication fd forwarding. */
2988:
1.49 markus 2989: void
1.142 itojun 2990: auth_request_forwarding(void)
1.1 deraadt 2991: {
1.25 markus 2992: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2993: packet_send();
2994: packet_write_wait();
1.1 deraadt 2995: }
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