Annotation of src/usr.bin/ssh/channels.c, Revision 1.213
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"
1.213 ! deraadt 42: RCSID("$OpenBSD: channels.c,v 1.212 2005/03/01 10:09:52 djm Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.h"
1.193 markus 57: #include "bufaux.h"
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.209 avsm 71: static u_int channels_alloc = 0;
1.1 deraadt 72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
112: /* Saved X11 authentication protocol name. */
113: static char *x11_saved_proto = NULL;
114:
115: /* Saved X11 authentication data. This is the real data. */
116: static char *x11_saved_data = NULL;
117: static u_int x11_saved_data_len = 0;
118:
119: /*
120: * Fake X11 authentication data. This is what the server will be sending us;
121: * we should replace any occurrences of this by the real data.
122: */
123: static char *x11_fake_data = NULL;
124: static u_int x11_fake_data_len;
125:
126:
127: /* -- agent forwarding */
128:
129: #define NUM_SOCKS 10
130:
1.82 markus 131: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 132: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 133:
1.121 markus 134: /* helper */
1.127 itojun 135: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 136:
1.121 markus 137: /* -- channel core */
1.41 markus 138:
139: Channel *
140: channel_lookup(int id)
141: {
142: Channel *c;
1.113 markus 143:
1.209 avsm 144: if (id < 0 || (u_int)id >= channels_alloc) {
1.188 itojun 145: logit("channel_lookup: %d: bad id", id);
1.41 markus 146: return NULL;
147: }
1.113 markus 148: c = channels[id];
149: if (c == NULL) {
1.188 itojun 150: logit("channel_lookup: %d: bad id: channel free", id);
1.41 markus 151: return NULL;
152: }
153: return c;
1.55 markus 154: }
155:
1.27 markus 156: /*
1.55 markus 157: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 158: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 159: */
1.1 deraadt 160:
1.127 itojun 161: static void
1.71 markus 162: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
163: int extusage, int nonblock)
1.1 deraadt 164: {
1.25 markus 165: /* Update the maximum file descriptor value. */
1.84 markus 166: channel_max_fd = MAX(channel_max_fd, rfd);
167: channel_max_fd = MAX(channel_max_fd, wfd);
168: channel_max_fd = MAX(channel_max_fd, efd);
169:
1.27 markus 170: /* XXX set close-on-exec -markus */
1.55 markus 171:
1.52 markus 172: c->rfd = rfd;
173: c->wfd = wfd;
174: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 175: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 176: c->efd = efd;
177: c->extended_usage = extusage;
1.71 markus 178:
1.91 markus 179: /* XXX ugly hack: nonblock is only set by the server */
180: if (nonblock && isatty(c->rfd)) {
1.194 markus 181: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 182: c->isatty = 1;
183: if (!isatty(c->wfd)) {
1.94 markus 184: error("channel %d: wfd %d is not a tty?",
1.91 markus 185: c->self, c->wfd);
186: }
187: } else {
188: c->isatty = 0;
189: }
190:
1.71 markus 191: /* enable nonblocking mode */
192: if (nonblock) {
193: if (rfd != -1)
194: set_nonblock(rfd);
195: if (wfd != -1)
196: set_nonblock(wfd);
197: if (efd != -1)
198: set_nonblock(efd);
199: }
1.52 markus 200: }
201:
202: /*
203: * Allocate a new channel object and set its type and socket. This will cause
204: * remote_name to be freed.
205: */
206:
1.113 markus 207: Channel *
1.52 markus 208: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 209: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 210: {
1.209 avsm 211: int found;
212: u_int i;
1.52 markus 213: Channel *c;
1.25 markus 214:
215: /* Do initial allocation if this is the first call. */
216: if (channels_alloc == 0) {
217: channels_alloc = 10;
1.113 markus 218: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 219: for (i = 0; i < channels_alloc; i++)
1.113 markus 220: channels[i] = NULL;
1.25 markus 221: }
222: /* Try to find a free slot where to put the new channel. */
223: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 224: if (channels[i] == NULL) {
1.25 markus 225: /* Found a free slot. */
1.209 avsm 226: found = (int)i;
1.25 markus 227: break;
228: }
1.209 avsm 229: if (found < 0) {
1.27 markus 230: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 231: found = channels_alloc;
1.179 markus 232: if (channels_alloc > 10000)
233: fatal("channel_new: internal error: channels_alloc %d "
234: "too big.", channels_alloc);
1.195 markus 235: channels = xrealloc(channels,
236: (channels_alloc + 10) * sizeof(Channel *));
237: channels_alloc += 10;
1.70 markus 238: debug2("channel: expanding %d", channels_alloc);
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 244: memset(c, 0, sizeof(Channel));
1.25 markus 245: buffer_init(&c->input);
246: buffer_init(&c->output);
1.41 markus 247: buffer_init(&c->extended);
1.159 markus 248: c->ostate = CHAN_OUTPUT_OPEN;
249: c->istate = CHAN_INPUT_OPEN;
250: c->flags = 0;
1.71 markus 251: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 252: c->self = found;
253: c->type = type;
1.41 markus 254: c->ctype = ctype;
1.51 markus 255: c->local_window = window;
256: c->local_window_max = window;
257: c->local_consumed = 0;
258: c->local_maxpacket = maxpack;
1.25 markus 259: c->remote_id = -1;
1.190 markus 260: c->remote_name = xstrdup(remote_name);
1.41 markus 261: c->remote_window = 0;
262: c->remote_maxpacket = 0;
1.133 markus 263: c->force_drain = 0;
1.149 markus 264: c->single_connection = 0;
1.131 markus 265: c->detach_user = NULL;
1.165 markus 266: c->confirm = NULL;
1.204 djm 267: c->confirm_ctx = NULL;
1.65 markus 268: c->input_filter = NULL;
1.25 markus 269: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 270: return c;
1.1 deraadt 271: }
1.52 markus 272:
1.132 markus 273: static int
274: channel_find_maxfd(void)
275: {
1.209 avsm 276: u_int i;
277: int max = 0;
1.132 markus 278: Channel *c;
279:
280: for (i = 0; i < channels_alloc; i++) {
281: c = channels[i];
282: if (c != NULL) {
283: max = MAX(max, c->rfd);
284: max = MAX(max, c->wfd);
285: max = MAX(max, c->efd);
286: }
287: }
288: return max;
289: }
290:
291: int
292: channel_close_fd(int *fdp)
293: {
294: int ret = 0, fd = *fdp;
295:
296: if (fd != -1) {
297: ret = close(fd);
298: *fdp = -1;
299: if (fd == channel_max_fd)
300: channel_max_fd = channel_find_maxfd();
301: }
302: return ret;
303: }
304:
1.52 markus 305: /* Close all channel fd/socket. */
306:
1.127 itojun 307: static void
1.52 markus 308: channel_close_fds(Channel *c)
309: {
1.204 djm 310: debug3("channel %d: close_fds r %d w %d e %d c %d",
311: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 312:
1.132 markus 313: channel_close_fd(&c->sock);
1.204 djm 314: channel_close_fd(&c->ctl_fd);
1.132 markus 315: channel_close_fd(&c->rfd);
316: channel_close_fd(&c->wfd);
317: channel_close_fd(&c->efd);
1.121 markus 318: }
319:
320: /* Free the channel and close its fd/socket. */
321:
322: void
323: channel_free(Channel *c)
324: {
325: char *s;
1.209 avsm 326: u_int i, n;
1.121 markus 327:
328: for (n = 0, i = 0; i < channels_alloc; i++)
329: if (channels[i])
330: n++;
1.209 avsm 331: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 332: c->remote_name ? c->remote_name : "???", n);
333:
334: s = channel_open_message();
1.194 markus 335: debug3("channel %d: status: %s", c->self, s);
1.121 markus 336: xfree(s);
337:
338: if (c->sock != -1)
339: shutdown(c->sock, SHUT_RDWR);
1.204 djm 340: if (c->ctl_fd != -1)
341: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 342: channel_close_fds(c);
343: buffer_free(&c->input);
344: buffer_free(&c->output);
345: buffer_free(&c->extended);
346: if (c->remote_name) {
347: xfree(c->remote_name);
348: c->remote_name = NULL;
349: }
350: channels[c->self] = NULL;
351: xfree(c);
352: }
353:
354: void
1.126 markus 355: channel_free_all(void)
1.121 markus 356: {
1.209 avsm 357: u_int i;
1.121 markus 358:
1.126 markus 359: for (i = 0; i < channels_alloc; i++)
360: if (channels[i] != NULL)
361: channel_free(channels[i]);
1.131 markus 362: }
363:
1.121 markus 364: /*
365: * Closes the sockets/fds of all channels. This is used to close extra file
366: * descriptors after a fork.
367: */
368:
369: void
1.142 itojun 370: channel_close_all(void)
1.121 markus 371: {
1.209 avsm 372: u_int i;
1.121 markus 373:
374: for (i = 0; i < channels_alloc; i++)
375: if (channels[i] != NULL)
376: channel_close_fds(channels[i]);
377: }
378:
379: /*
1.131 markus 380: * Stop listening to channels.
381: */
382:
383: void
384: channel_stop_listening(void)
385: {
1.209 avsm 386: u_int i;
1.131 markus 387: Channel *c;
388:
389: for (i = 0; i < channels_alloc; i++) {
390: c = channels[i];
391: if (c != NULL) {
392: switch (c->type) {
393: case SSH_CHANNEL_AUTH_SOCKET:
394: case SSH_CHANNEL_PORT_LISTENER:
395: case SSH_CHANNEL_RPORT_LISTENER:
396: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 397: channel_close_fd(&c->sock);
1.131 markus 398: channel_free(c);
399: break;
400: }
401: }
402: }
403: }
404:
405: /*
1.121 markus 406: * Returns true if no channel has too much buffered data, and false if one or
407: * more channel is overfull.
408: */
409:
410: int
1.142 itojun 411: channel_not_very_much_buffered_data(void)
1.121 markus 412: {
413: u_int i;
414: Channel *c;
415:
416: for (i = 0; i < channels_alloc; i++) {
417: c = channels[i];
418: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 419: #if 0
420: if (!compat20 &&
421: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 422: debug2("channel %d: big input buffer %d",
1.121 markus 423: c->self, buffer_len(&c->input));
424: return 0;
425: }
1.136 markus 426: #endif
1.121 markus 427: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 428: debug2("channel %d: big output buffer %u > %u",
1.136 markus 429: c->self, buffer_len(&c->output),
430: packet_get_maxsize());
1.121 markus 431: return 0;
432: }
433: }
434: }
435: return 1;
436: }
437:
438: /* Returns true if any channel is still open. */
439:
440: int
1.142 itojun 441: channel_still_open(void)
1.121 markus 442: {
1.209 avsm 443: u_int i;
1.121 markus 444: Channel *c;
445:
446: for (i = 0; i < channels_alloc; i++) {
447: c = channels[i];
448: if (c == NULL)
449: continue;
450: switch (c->type) {
451: case SSH_CHANNEL_X11_LISTENER:
452: case SSH_CHANNEL_PORT_LISTENER:
453: case SSH_CHANNEL_RPORT_LISTENER:
454: case SSH_CHANNEL_CLOSED:
455: case SSH_CHANNEL_AUTH_SOCKET:
456: case SSH_CHANNEL_DYNAMIC:
457: case SSH_CHANNEL_CONNECTING:
458: case SSH_CHANNEL_ZOMBIE:
459: continue;
460: case SSH_CHANNEL_LARVAL:
461: if (!compat20)
462: fatal("cannot happen: SSH_CHANNEL_LARVAL");
463: continue;
464: case SSH_CHANNEL_OPENING:
465: case SSH_CHANNEL_OPEN:
466: case SSH_CHANNEL_X11_OPEN:
467: return 1;
468: case SSH_CHANNEL_INPUT_DRAINING:
469: case SSH_CHANNEL_OUTPUT_DRAINING:
470: if (!compat13)
471: fatal("cannot happen: OUT_DRAIN");
472: return 1;
473: default:
474: fatal("channel_still_open: bad channel type %d", c->type);
475: /* NOTREACHED */
476: }
477: }
478: return 0;
479: }
480:
481: /* Returns the id of an open channel suitable for keepaliving */
482:
483: int
1.142 itojun 484: channel_find_open(void)
1.121 markus 485: {
1.209 avsm 486: u_int i;
1.121 markus 487: Channel *c;
488:
489: for (i = 0; i < channels_alloc; i++) {
490: c = channels[i];
1.206 djm 491: if (c == NULL || c->remote_id < 0)
1.121 markus 492: continue;
493: switch (c->type) {
494: case SSH_CHANNEL_CLOSED:
495: case SSH_CHANNEL_DYNAMIC:
496: case SSH_CHANNEL_X11_LISTENER:
497: case SSH_CHANNEL_PORT_LISTENER:
498: case SSH_CHANNEL_RPORT_LISTENER:
499: case SSH_CHANNEL_OPENING:
500: case SSH_CHANNEL_CONNECTING:
501: case SSH_CHANNEL_ZOMBIE:
502: continue;
503: case SSH_CHANNEL_LARVAL:
504: case SSH_CHANNEL_AUTH_SOCKET:
505: case SSH_CHANNEL_OPEN:
506: case SSH_CHANNEL_X11_OPEN:
507: return i;
508: case SSH_CHANNEL_INPUT_DRAINING:
509: case SSH_CHANNEL_OUTPUT_DRAINING:
510: if (!compat13)
511: fatal("cannot happen: OUT_DRAIN");
512: return i;
513: default:
514: fatal("channel_find_open: bad channel type %d", c->type);
515: /* NOTREACHED */
516: }
517: }
518: return -1;
519: }
520:
521:
522: /*
523: * Returns a message describing the currently open forwarded connections,
524: * suitable for sending to the client. The message contains crlf pairs for
525: * newlines.
526: */
527:
528: char *
1.142 itojun 529: channel_open_message(void)
1.121 markus 530: {
531: Buffer buffer;
532: Channel *c;
533: char buf[1024], *cp;
1.209 avsm 534: u_int i;
1.121 markus 535:
536: buffer_init(&buffer);
537: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
538: buffer_append(&buffer, buf, strlen(buf));
539: for (i = 0; i < channels_alloc; i++) {
540: c = channels[i];
541: if (c == NULL)
542: continue;
543: switch (c->type) {
544: case SSH_CHANNEL_X11_LISTENER:
545: case SSH_CHANNEL_PORT_LISTENER:
546: case SSH_CHANNEL_RPORT_LISTENER:
547: case SSH_CHANNEL_CLOSED:
548: case SSH_CHANNEL_AUTH_SOCKET:
549: case SSH_CHANNEL_ZOMBIE:
550: continue;
551: case SSH_CHANNEL_LARVAL:
552: case SSH_CHANNEL_OPENING:
553: case SSH_CHANNEL_CONNECTING:
554: case SSH_CHANNEL_DYNAMIC:
555: case SSH_CHANNEL_OPEN:
556: case SSH_CHANNEL_X11_OPEN:
557: case SSH_CHANNEL_INPUT_DRAINING:
558: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 559: snprintf(buf, sizeof buf,
560: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 561: c->self, c->remote_name,
562: c->type, c->remote_id,
563: c->istate, buffer_len(&c->input),
564: c->ostate, buffer_len(&c->output),
1.204 djm 565: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 566: buffer_append(&buffer, buf, strlen(buf));
567: continue;
568: default:
569: fatal("channel_open_message: bad channel type %d", c->type);
570: /* NOTREACHED */
571: }
572: }
573: buffer_append(&buffer, "\0", 1);
574: cp = xstrdup(buffer_ptr(&buffer));
575: buffer_free(&buffer);
576: return cp;
577: }
578:
579: void
580: channel_send_open(int id)
581: {
582: Channel *c = channel_lookup(id);
1.180 deraadt 583:
1.121 markus 584: if (c == NULL) {
1.188 itojun 585: logit("channel_send_open: %d: bad id", id);
1.121 markus 586: return;
587: }
1.184 markus 588: debug2("channel %d: send open", id);
1.121 markus 589: packet_start(SSH2_MSG_CHANNEL_OPEN);
590: packet_put_cstring(c->ctype);
591: packet_put_int(c->self);
592: packet_put_int(c->local_window);
593: packet_put_int(c->local_maxpacket);
594: packet_send();
595: }
596:
597: void
1.184 markus 598: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 599: {
1.184 markus 600: Channel *c = channel_lookup(id);
1.180 deraadt 601:
1.121 markus 602: if (c == NULL) {
1.188 itojun 603: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 604: return;
605: }
1.204 djm 606: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 607: packet_start(SSH2_MSG_CHANNEL_REQUEST);
608: packet_put_int(c->remote_id);
609: packet_put_cstring(service);
610: packet_put_char(wantconfirm);
611: }
612: void
1.204 djm 613: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 614: {
615: Channel *c = channel_lookup(id);
1.180 deraadt 616:
1.121 markus 617: if (c == NULL) {
1.188 itojun 618: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 619: return;
620: }
1.165 markus 621: c->confirm = fn;
1.204 djm 622: c->confirm_ctx = ctx;
1.121 markus 623: }
624: void
625: channel_register_cleanup(int id, channel_callback_fn *fn)
626: {
627: Channel *c = channel_lookup(id);
1.180 deraadt 628:
1.121 markus 629: if (c == NULL) {
1.188 itojun 630: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 631: return;
632: }
1.131 markus 633: c->detach_user = fn;
1.121 markus 634: }
635: void
636: channel_cancel_cleanup(int id)
637: {
638: Channel *c = channel_lookup(id);
1.180 deraadt 639:
1.121 markus 640: if (c == NULL) {
1.188 itojun 641: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 642: return;
1.52 markus 643: }
1.131 markus 644: c->detach_user = NULL;
1.121 markus 645: }
646: void
647: channel_register_filter(int id, channel_filter_fn *fn)
648: {
649: Channel *c = channel_lookup(id);
1.180 deraadt 650:
1.121 markus 651: if (c == NULL) {
1.188 itojun 652: logit("channel_register_filter: %d: bad id", id);
1.121 markus 653: return;
1.52 markus 654: }
1.121 markus 655: c->input_filter = fn;
1.52 markus 656: }
657:
1.49 markus 658: void
1.121 markus 659: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 660: int extusage, int nonblock, u_int window_max)
1.1 deraadt 661: {
1.121 markus 662: Channel *c = channel_lookup(id);
1.180 deraadt 663:
1.121 markus 664: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
665: fatal("channel_activate for non-larval channel %d.", id);
666: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
667: c->type = SSH_CHANNEL_OPEN;
1.168 markus 668: c->local_window = c->local_window_max = window_max;
1.121 markus 669: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
670: packet_put_int(c->remote_id);
671: packet_put_int(c->local_window);
672: packet_send();
1.1 deraadt 673: }
674:
1.27 markus 675: /*
1.41 markus 676: * 'channel_pre*' are called just before select() to add any bits relevant to
677: * channels in the select bitmasks.
678: */
679: /*
680: * 'channel_post*': perform any appropriate operations for channels which
681: * have events pending.
1.27 markus 682: */
1.41 markus 683: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
684: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
685: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
686:
1.127 itojun 687: static void
1.41 markus 688: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
689: {
690: FD_SET(c->sock, readset);
691: }
692:
1.127 itojun 693: static void
1.75 markus 694: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
695: {
696: debug3("channel %d: waiting for connection", c->self);
697: FD_SET(c->sock, writeset);
698: }
699:
1.127 itojun 700: static void
1.41 markus 701: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
702: {
703: if (buffer_len(&c->input) < packet_get_maxsize())
704: FD_SET(c->sock, readset);
705: if (buffer_len(&c->output) > 0)
706: FD_SET(c->sock, writeset);
707: }
1.1 deraadt 708:
1.127 itojun 709: static void
1.157 markus 710: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 711: {
1.157 markus 712: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 713:
1.44 markus 714: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 715: limit > 0 &&
716: buffer_len(&c->input) < limit)
1.44 markus 717: FD_SET(c->rfd, readset);
718: if (c->ostate == CHAN_OUTPUT_OPEN ||
719: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
720: if (buffer_len(&c->output) > 0) {
721: FD_SET(c->wfd, writeset);
722: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 723: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.174 markus 724: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
725: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 726: else
727: chan_obuf_empty(c);
1.44 markus 728: }
729: }
730: /** XXX check close conditions, too */
1.157 markus 731: if (compat20 && c->efd != -1) {
1.44 markus 732: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
733: buffer_len(&c->extended) > 0)
734: FD_SET(c->efd, writeset);
1.172 markus 735: else if (!(c->flags & CHAN_EOF_SENT) &&
736: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 737: buffer_len(&c->extended) < c->remote_window)
738: FD_SET(c->efd, readset);
739: }
1.204 djm 740: /* XXX: What about efd? races? */
1.208 deraadt 741: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 742: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
743: FD_SET(c->ctl_fd, readset);
1.44 markus 744: }
745:
1.127 itojun 746: static void
1.41 markus 747: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
748: {
749: if (buffer_len(&c->input) == 0) {
750: packet_start(SSH_MSG_CHANNEL_CLOSE);
751: packet_put_int(c->remote_id);
752: packet_send();
753: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 754: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 755: }
756: }
757:
1.127 itojun 758: static void
1.41 markus 759: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
760: {
761: if (buffer_len(&c->output) == 0)
1.113 markus 762: chan_mark_dead(c);
1.49 markus 763: else
1.41 markus 764: FD_SET(c->sock, writeset);
765: }
766:
767: /*
768: * This is a special state for X11 authentication spoofing. An opened X11
769: * connection (when authentication spoofing is being done) remains in this
770: * state until the first packet has been completely read. The authentication
771: * data in that packet is then substituted by the real data if it matches the
772: * fake data, and the channel is put into normal mode.
1.51 markus 773: * XXX All this happens at the client side.
1.121 markus 774: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 775: */
1.127 itojun 776: static int
1.121 markus 777: x11_open_helper(Buffer *b)
1.1 deraadt 778: {
1.77 markus 779: u_char *ucp;
780: u_int proto_len, data_len;
1.25 markus 781:
1.41 markus 782: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 783: if (buffer_len(b) < 12)
1.41 markus 784: return 0;
785:
786: /* Parse the lengths of variable-length fields. */
1.155 stevesk 787: ucp = buffer_ptr(b);
1.41 markus 788: if (ucp[0] == 0x42) { /* Byte order MSB first. */
789: proto_len = 256 * ucp[6] + ucp[7];
790: data_len = 256 * ucp[8] + ucp[9];
791: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
792: proto_len = ucp[6] + 256 * ucp[7];
793: data_len = ucp[8] + 256 * ucp[9];
794: } else {
1.194 markus 795: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 796: ucp[0]);
1.41 markus 797: return -1;
798: }
799:
800: /* Check if the whole packet is in buffer. */
1.121 markus 801: if (buffer_len(b) <
1.41 markus 802: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
803: return 0;
804:
805: /* Check if authentication protocol matches. */
806: if (proto_len != strlen(x11_saved_proto) ||
807: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 808: debug2("X11 connection uses different authentication protocol.");
1.41 markus 809: return -1;
810: }
811: /* Check if authentication data matches our fake data. */
812: if (data_len != x11_fake_data_len ||
813: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
814: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 815: debug2("X11 auth data does not match fake data.");
1.41 markus 816: return -1;
817: }
818: /* Check fake data length */
819: if (x11_fake_data_len != x11_saved_data_len) {
820: error("X11 fake_data_len %d != saved_data_len %d",
821: x11_fake_data_len, x11_saved_data_len);
822: return -1;
823: }
824: /*
825: * Received authentication protocol and data match
826: * our fake data. Substitute the fake data with real
827: * data.
828: */
829: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
830: x11_saved_data, x11_saved_data_len);
831: return 1;
832: }
833:
1.127 itojun 834: static void
1.41 markus 835: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
836: {
1.121 markus 837: int ret = x11_open_helper(&c->output);
1.180 deraadt 838:
1.41 markus 839: if (ret == 1) {
840: /* Start normal processing for the channel. */
841: c->type = SSH_CHANNEL_OPEN;
1.47 markus 842: channel_pre_open_13(c, readset, writeset);
1.41 markus 843: } else if (ret == -1) {
844: /*
845: * We have received an X11 connection that has bad
846: * authentication information.
847: */
1.188 itojun 848: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 849: buffer_clear(&c->input);
850: buffer_clear(&c->output);
1.132 markus 851: channel_close_fd(&c->sock);
1.41 markus 852: c->sock = -1;
853: c->type = SSH_CHANNEL_CLOSED;
854: packet_start(SSH_MSG_CHANNEL_CLOSE);
855: packet_put_int(c->remote_id);
856: packet_send();
857: }
858: }
1.25 markus 859:
1.127 itojun 860: static void
1.51 markus 861: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 862: {
1.121 markus 863: int ret = x11_open_helper(&c->output);
1.133 markus 864:
865: /* c->force_drain = 1; */
866:
1.41 markus 867: if (ret == 1) {
868: c->type = SSH_CHANNEL_OPEN;
1.157 markus 869: channel_pre_open(c, readset, writeset);
1.41 markus 870: } else if (ret == -1) {
1.188 itojun 871: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 872: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 873: chan_read_failed(c);
874: buffer_clear(&c->input);
875: chan_ibuf_empty(c);
876: buffer_clear(&c->output);
877: /* for proto v1, the peer will send an IEOF */
878: if (compat20)
879: chan_write_failed(c);
880: else
881: c->type = SSH_CHANNEL_OPEN;
1.194 markus 882: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 883: }
884: }
1.25 markus 885:
1.104 markus 886: /* try to decode a socks4 header */
1.127 itojun 887: static int
1.104 markus 888: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 889: {
1.181 markus 890: char *p, *host;
1.109 markus 891: int len, have, i, found;
1.148 deraadt 892: char username[256];
1.103 markus 893: struct {
894: u_int8_t version;
895: u_int8_t command;
896: u_int16_t dest_port;
1.104 markus 897: struct in_addr dest_addr;
1.103 markus 898: } s4_req, s4_rsp;
899:
1.104 markus 900: debug2("channel %d: decode socks4", c->self);
1.109 markus 901:
902: have = buffer_len(&c->input);
903: len = sizeof(s4_req);
904: if (have < len)
905: return 0;
906: p = buffer_ptr(&c->input);
907: for (found = 0, i = len; i < have; i++) {
908: if (p[i] == '\0') {
909: found = 1;
910: break;
911: }
912: if (i > 1024) {
913: /* the peer is probably sending garbage */
914: debug("channel %d: decode socks4: too long",
915: c->self);
916: return -1;
917: }
918: }
919: if (!found)
920: return 0;
1.103 markus 921: buffer_get(&c->input, (char *)&s4_req.version, 1);
922: buffer_get(&c->input, (char *)&s4_req.command, 1);
923: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 924: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 925: have = buffer_len(&c->input);
1.103 markus 926: p = buffer_ptr(&c->input);
927: len = strlen(p);
1.106 markus 928: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 929: if (len > have)
1.104 markus 930: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 931: c->self, len, have);
932: strlcpy(username, p, sizeof(username));
933: buffer_consume(&c->input, len);
934: buffer_consume(&c->input, 1); /* trailing '\0' */
935:
1.104 markus 936: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 937: strlcpy(c->path, host, sizeof(c->path));
938: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 939:
1.194 markus 940: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 941: c->self, host, c->host_port, s4_req.command);
1.103 markus 942:
1.104 markus 943: if (s4_req.command != 1) {
944: debug("channel %d: cannot handle: socks4 cn %d",
945: c->self, s4_req.command);
946: return -1;
1.103 markus 947: }
1.104 markus 948: s4_rsp.version = 0; /* vn: 0 for reply */
949: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 950: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 951: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 952: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 953: return 1;
954: }
955:
1.193 markus 956: /* try to decode a socks5 header */
957: #define SSH_SOCKS5_AUTHDONE 0x1000
958: #define SSH_SOCKS5_NOAUTH 0x00
959: #define SSH_SOCKS5_IPV4 0x01
960: #define SSH_SOCKS5_DOMAIN 0x03
961: #define SSH_SOCKS5_IPV6 0x04
962: #define SSH_SOCKS5_CONNECT 0x01
963: #define SSH_SOCKS5_SUCCESS 0x00
964:
965: static int
966: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
967: {
968: struct {
969: u_int8_t version;
970: u_int8_t command;
971: u_int8_t reserved;
972: u_int8_t atyp;
973: } s5_req, s5_rsp;
974: u_int16_t dest_port;
975: u_char *p, dest_addr[255+1];
976: int i, have, found, nmethods, addrlen, af;
977:
978: debug2("channel %d: decode socks5", c->self);
979: p = buffer_ptr(&c->input);
980: if (p[0] != 0x05)
981: return -1;
982: have = buffer_len(&c->input);
983: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
984: /* format: ver | nmethods | methods */
1.198 djm 985: if (have < 2)
1.193 markus 986: return 0;
987: nmethods = p[1];
988: if (have < nmethods + 2)
989: return 0;
990: /* look for method: "NO AUTHENTICATION REQUIRED" */
991: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
992: if (p[i] == SSH_SOCKS5_NOAUTH ) {
993: found = 1;
994: break;
995: }
996: }
997: if (!found) {
998: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
999: c->self);
1000: return -1;
1001: }
1002: buffer_consume(&c->input, nmethods + 2);
1003: buffer_put_char(&c->output, 0x05); /* version */
1004: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1005: FD_SET(c->sock, writeset);
1006: c->flags |= SSH_SOCKS5_AUTHDONE;
1007: debug2("channel %d: socks5 auth done", c->self);
1008: return 0; /* need more */
1009: }
1010: debug2("channel %d: socks5 post auth", c->self);
1011: if (have < sizeof(s5_req)+1)
1012: return 0; /* need more */
1013: memcpy((char *)&s5_req, p, sizeof(s5_req));
1014: if (s5_req.version != 0x05 ||
1015: s5_req.command != SSH_SOCKS5_CONNECT ||
1016: s5_req.reserved != 0x00) {
1.194 markus 1017: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1018: return -1;
1019: }
1.213 ! deraadt 1020: switch (s5_req.atyp){
1.193 markus 1021: case SSH_SOCKS5_IPV4:
1022: addrlen = 4;
1023: af = AF_INET;
1024: break;
1025: case SSH_SOCKS5_DOMAIN:
1026: addrlen = p[sizeof(s5_req)];
1027: af = -1;
1028: break;
1029: case SSH_SOCKS5_IPV6:
1030: addrlen = 16;
1031: af = AF_INET6;
1032: break;
1033: default:
1.194 markus 1034: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1035: return -1;
1036: }
1037: if (have < 4 + addrlen + 2)
1038: return 0;
1039: buffer_consume(&c->input, sizeof(s5_req));
1040: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1041: buffer_consume(&c->input, 1); /* host string length */
1042: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1043: buffer_get(&c->input, (char *)&dest_port, 2);
1044: dest_addr[addrlen] = '\0';
1045: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1046: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1047: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1048: return -1;
1049: c->host_port = ntohs(dest_port);
1.198 djm 1050:
1.194 markus 1051: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1052: c->self, c->path, c->host_port, s5_req.command);
1053:
1054: s5_rsp.version = 0x05;
1055: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1056: s5_rsp.reserved = 0; /* ignored */
1057: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1058: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1059: dest_port = 0; /* ignored */
1060:
1061: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1062: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1063: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1064: return 1;
1065: }
1066:
1.104 markus 1067: /* dynamic port forwarding */
1.127 itojun 1068: static void
1.104 markus 1069: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1070: {
1071: u_char *p;
1072: int have, ret;
1.103 markus 1073:
1.104 markus 1074: have = buffer_len(&c->input);
1.137 markus 1075: c->delayed = 0;
1.104 markus 1076: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1077: /* buffer_dump(&c->input); */
1.104 markus 1078: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1079: if (have < 3) {
1.104 markus 1080: /* need more */
1081: FD_SET(c->sock, readset);
1082: return;
1083: }
1084: /* try to guess the protocol */
1085: p = buffer_ptr(&c->input);
1086: switch (p[0]) {
1087: case 0x04:
1088: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1089: break;
1090: case 0x05:
1091: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1092: break;
1093: default:
1094: ret = -1;
1095: break;
1096: }
1097: if (ret < 0) {
1.113 markus 1098: chan_mark_dead(c);
1.104 markus 1099: } else if (ret == 0) {
1100: debug2("channel %d: pre_dynamic: need more", c->self);
1101: /* need more */
1102: FD_SET(c->sock, readset);
1103: } else {
1104: /* switch to the next state */
1105: c->type = SSH_CHANNEL_OPENING;
1106: port_open_helper(c, "direct-tcpip");
1107: }
1.103 markus 1108: }
1109:
1.41 markus 1110: /* This is our fake X11 server socket. */
1.127 itojun 1111: static void
1.41 markus 1112: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1113: {
1.113 markus 1114: Channel *nc;
1.41 markus 1115: struct sockaddr addr;
1.162 stevesk 1116: int newsock;
1.41 markus 1117: socklen_t addrlen;
1.85 markus 1118: char buf[16384], *remote_ipaddr;
1.51 markus 1119: int remote_port;
1.25 markus 1120:
1.41 markus 1121: if (FD_ISSET(c->sock, readset)) {
1122: debug("X11 connection requested.");
1123: addrlen = sizeof(addr);
1124: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1125: if (c->single_connection) {
1.194 markus 1126: debug2("single_connection: closing X11 listener.");
1.149 markus 1127: channel_close_fd(&c->sock);
1128: chan_mark_dead(c);
1129: }
1.41 markus 1130: if (newsock < 0) {
1131: error("accept: %.100s", strerror(errno));
1132: return;
1133: }
1.162 stevesk 1134: set_nodelay(newsock);
1.85 markus 1135: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1136: remote_port = get_peer_port(newsock);
1.41 markus 1137: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1138: remote_ipaddr, remote_port);
1.51 markus 1139:
1.113 markus 1140: nc = channel_new("accepted x11 socket",
1.51 markus 1141: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1142: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1143: if (compat20) {
1144: packet_start(SSH2_MSG_CHANNEL_OPEN);
1145: packet_put_cstring("x11");
1.113 markus 1146: packet_put_int(nc->self);
1.149 markus 1147: packet_put_int(nc->local_window_max);
1148: packet_put_int(nc->local_maxpacket);
1.85 markus 1149: /* originator ipaddr and port */
1150: packet_put_cstring(remote_ipaddr);
1.57 markus 1151: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1152: debug2("ssh2 x11 bug compat mode");
1.57 markus 1153: } else {
1154: packet_put_int(remote_port);
1155: }
1.51 markus 1156: packet_send();
1157: } else {
1158: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1159: packet_put_int(nc->self);
1.121 markus 1160: if (packet_get_protocol_flags() &
1161: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1162: packet_put_cstring(buf);
1.51 markus 1163: packet_send();
1164: }
1.85 markus 1165: xfree(remote_ipaddr);
1.41 markus 1166: }
1167: }
1.25 markus 1168:
1.127 itojun 1169: static void
1.103 markus 1170: port_open_helper(Channel *c, char *rtype)
1171: {
1172: int direct;
1173: char buf[1024];
1174: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1175: u_short remote_port = get_peer_port(c->sock);
1176:
1177: direct = (strcmp(rtype, "direct-tcpip") == 0);
1178:
1179: snprintf(buf, sizeof buf,
1180: "%s: listening port %d for %.100s port %d, "
1181: "connect from %.200s port %d",
1182: rtype, c->listening_port, c->path, c->host_port,
1183: remote_ipaddr, remote_port);
1184:
1185: xfree(c->remote_name);
1186: c->remote_name = xstrdup(buf);
1187:
1188: if (compat20) {
1189: packet_start(SSH2_MSG_CHANNEL_OPEN);
1190: packet_put_cstring(rtype);
1191: packet_put_int(c->self);
1192: packet_put_int(c->local_window_max);
1193: packet_put_int(c->local_maxpacket);
1194: if (direct) {
1195: /* target host, port */
1196: packet_put_cstring(c->path);
1197: packet_put_int(c->host_port);
1198: } else {
1199: /* listen address, port */
1200: packet_put_cstring(c->path);
1201: packet_put_int(c->listening_port);
1202: }
1203: /* originator host and port */
1204: packet_put_cstring(remote_ipaddr);
1205: packet_put_int(remote_port);
1206: packet_send();
1207: } else {
1208: packet_start(SSH_MSG_PORT_OPEN);
1209: packet_put_int(c->self);
1210: packet_put_cstring(c->path);
1211: packet_put_int(c->host_port);
1.121 markus 1212: if (packet_get_protocol_flags() &
1213: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1214: packet_put_cstring(c->remote_name);
1215: packet_send();
1216: }
1217: xfree(remote_ipaddr);
1218: }
1219:
1.41 markus 1220: /*
1221: * This socket is listening for connections to a forwarded TCP/IP port.
1222: */
1.127 itojun 1223: static void
1.41 markus 1224: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1225: {
1.103 markus 1226: Channel *nc;
1.41 markus 1227: struct sockaddr addr;
1.113 markus 1228: int newsock, nextstate;
1.41 markus 1229: socklen_t addrlen;
1.103 markus 1230: char *rtype;
1.73 markus 1231:
1.41 markus 1232: if (FD_ISSET(c->sock, readset)) {
1233: debug("Connection to port %d forwarding "
1234: "to %.100s port %d requested.",
1235: c->listening_port, c->path, c->host_port);
1.103 markus 1236:
1.137 markus 1237: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1238: nextstate = SSH_CHANNEL_OPENING;
1239: rtype = "forwarded-tcpip";
1240: } else {
1241: if (c->host_port == 0) {
1242: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1243: rtype = "dynamic-tcpip";
1.137 markus 1244: } else {
1245: nextstate = SSH_CHANNEL_OPENING;
1246: rtype = "direct-tcpip";
1247: }
1248: }
1.103 markus 1249:
1.41 markus 1250: addrlen = sizeof(addr);
1251: newsock = accept(c->sock, &addr, &addrlen);
1252: if (newsock < 0) {
1253: error("accept: %.100s", strerror(errno));
1254: return;
1255: }
1.169 stevesk 1256: set_nodelay(newsock);
1.190 markus 1257: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1258: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1259: nc->listening_port = c->listening_port;
1260: nc->host_port = c->host_port;
1261: strlcpy(nc->path, c->path, sizeof(nc->path));
1262:
1.137 markus 1263: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1264: /*
1265: * do not call the channel_post handler until
1266: * this flag has been reset by a pre-handler.
1267: * otherwise the FD_ISSET calls might overflow
1268: */
1269: nc->delayed = 1;
1270: } else {
1.103 markus 1271: port_open_helper(nc, rtype);
1.137 markus 1272: }
1.41 markus 1273: }
1274: }
1.25 markus 1275:
1.41 markus 1276: /*
1277: * This is the authentication agent socket listening for connections from
1278: * clients.
1279: */
1.127 itojun 1280: static void
1.41 markus 1281: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1282: {
1.113 markus 1283: Channel *nc;
1284: int newsock;
1.41 markus 1285: struct sockaddr addr;
1286: socklen_t addrlen;
1.25 markus 1287:
1.41 markus 1288: if (FD_ISSET(c->sock, readset)) {
1289: addrlen = sizeof(addr);
1290: newsock = accept(c->sock, &addr, &addrlen);
1291: if (newsock < 0) {
1292: error("accept from auth socket: %.100s", strerror(errno));
1293: return;
1294: }
1.113 markus 1295: nc = channel_new("accepted auth socket",
1.73 markus 1296: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1297: c->local_window_max, c->local_maxpacket,
1.190 markus 1298: 0, "accepted auth socket", 1);
1.73 markus 1299: if (compat20) {
1300: packet_start(SSH2_MSG_CHANNEL_OPEN);
1301: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1302: packet_put_int(nc->self);
1.73 markus 1303: packet_put_int(c->local_window_max);
1304: packet_put_int(c->local_maxpacket);
1305: } else {
1306: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1307: packet_put_int(nc->self);
1.73 markus 1308: }
1.41 markus 1309: packet_send();
1310: }
1311: }
1.25 markus 1312:
1.127 itojun 1313: static void
1.75 markus 1314: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1315: {
1.114 markus 1316: int err = 0;
1.129 stevesk 1317: socklen_t sz = sizeof(err);
1.114 markus 1318:
1.75 markus 1319: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1320: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1321: err = errno;
1322: error("getsockopt SO_ERROR failed");
1323: }
1324: if (err == 0) {
1325: debug("channel %d: connected", c->self);
1326: c->type = SSH_CHANNEL_OPEN;
1327: if (compat20) {
1328: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1329: packet_put_int(c->remote_id);
1330: packet_put_int(c->self);
1331: packet_put_int(c->local_window);
1332: packet_put_int(c->local_maxpacket);
1333: } else {
1334: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1335: packet_put_int(c->remote_id);
1336: packet_put_int(c->self);
1337: }
1.75 markus 1338: } else {
1.114 markus 1339: debug("channel %d: not connected: %s",
1340: c->self, strerror(err));
1341: if (compat20) {
1342: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1343: packet_put_int(c->remote_id);
1344: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1345: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1346: packet_put_cstring(strerror(err));
1347: packet_put_cstring("");
1348: }
1.75 markus 1349: } else {
1.114 markus 1350: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1351: packet_put_int(c->remote_id);
1.75 markus 1352: }
1.114 markus 1353: chan_mark_dead(c);
1.75 markus 1354: }
1.114 markus 1355: packet_send();
1.75 markus 1356: }
1357: }
1358:
1.127 itojun 1359: static int
1.41 markus 1360: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1361: {
1362: char buf[16*1024];
1363: int len;
1.25 markus 1364:
1.118 markus 1365: if (c->rfd != -1 &&
1.41 markus 1366: FD_ISSET(c->rfd, readset)) {
1367: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1368: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1369: return 1;
1.41 markus 1370: if (len <= 0) {
1.194 markus 1371: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1372: c->self, c->rfd, len);
1.104 markus 1373: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1374: debug2("channel %d: not open", c->self);
1.113 markus 1375: chan_mark_dead(c);
1.103 markus 1376: return -1;
1.104 markus 1377: } else if (compat13) {
1.158 markus 1378: buffer_clear(&c->output);
1.41 markus 1379: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1380: debug2("channel %d: input draining.", c->self);
1.25 markus 1381: } else {
1.41 markus 1382: chan_read_failed(c);
1.25 markus 1383: }
1.41 markus 1384: return -1;
1385: }
1.143 deraadt 1386: if (c->input_filter != NULL) {
1.66 markus 1387: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1388: debug2("channel %d: filter stops", c->self);
1.65 markus 1389: chan_read_failed(c);
1390: }
1391: } else {
1392: buffer_append(&c->input, buf, len);
1393: }
1.41 markus 1394: }
1395: return 1;
1396: }
1.127 itojun 1397: static int
1.41 markus 1398: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1399: {
1.95 markus 1400: struct termios tio;
1.134 markus 1401: u_char *data;
1402: u_int dlen;
1.41 markus 1403: int len;
1.25 markus 1404:
1.41 markus 1405: /* Send buffered output data to the socket. */
1.118 markus 1406: if (c->wfd != -1 &&
1.41 markus 1407: FD_ISSET(c->wfd, writeset) &&
1408: buffer_len(&c->output) > 0) {
1.134 markus 1409: data = buffer_ptr(&c->output);
1410: dlen = buffer_len(&c->output);
1411: len = write(c->wfd, data, dlen);
1.53 markus 1412: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1413: return 1;
1.41 markus 1414: if (len <= 0) {
1.104 markus 1415: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1416: debug2("channel %d: not open", c->self);
1.113 markus 1417: chan_mark_dead(c);
1.104 markus 1418: return -1;
1419: } else if (compat13) {
1.158 markus 1420: buffer_clear(&c->output);
1.194 markus 1421: debug2("channel %d: input draining.", c->self);
1.41 markus 1422: c->type = SSH_CHANNEL_INPUT_DRAINING;
1423: } else {
1424: chan_write_failed(c);
1425: }
1426: return -1;
1.91 markus 1427: }
1.134 markus 1428: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1429: if (tcgetattr(c->wfd, &tio) == 0 &&
1430: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1431: /*
1432: * Simulate echo to reduce the impact of
1.96 markus 1433: * traffic analysis. We need to match the
1.95 markus 1434: * size of a SSH2_MSG_CHANNEL_DATA message
1435: * (4 byte channel id + data)
1.91 markus 1436: */
1.95 markus 1437: packet_send_ignore(4 + len);
1.91 markus 1438: packet_send();
1439: }
1.25 markus 1440: }
1.41 markus 1441: buffer_consume(&c->output, len);
1.44 markus 1442: if (compat20 && len > 0) {
1443: c->local_consumed += len;
1444: }
1445: }
1446: return 1;
1447: }
1.127 itojun 1448: static int
1.44 markus 1449: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1450: {
1451: char buf[16*1024];
1452: int len;
1453:
1.45 markus 1454: /** XXX handle drain efd, too */
1.44 markus 1455: if (c->efd != -1) {
1456: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1457: FD_ISSET(c->efd, writeset) &&
1458: buffer_len(&c->extended) > 0) {
1459: len = write(c->efd, buffer_ptr(&c->extended),
1460: buffer_len(&c->extended));
1.70 markus 1461: debug2("channel %d: written %d to efd %d",
1.44 markus 1462: c->self, len, c->efd);
1.93 markus 1463: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1464: return 1;
1465: if (len <= 0) {
1466: debug2("channel %d: closing write-efd %d",
1467: c->self, c->efd);
1.132 markus 1468: channel_close_fd(&c->efd);
1.93 markus 1469: } else {
1.44 markus 1470: buffer_consume(&c->extended, len);
1471: c->local_consumed += len;
1472: }
1473: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1474: FD_ISSET(c->efd, readset)) {
1475: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1476: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1477: c->self, len, c->efd);
1.93 markus 1478: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1479: return 1;
1480: if (len <= 0) {
1481: debug2("channel %d: closing read-efd %d",
1.45 markus 1482: c->self, c->efd);
1.132 markus 1483: channel_close_fd(&c->efd);
1.93 markus 1484: } else {
1.44 markus 1485: buffer_append(&c->extended, buf, len);
1.93 markus 1486: }
1.44 markus 1487: }
1488: }
1489: return 1;
1490: }
1.127 itojun 1491: static int
1.204 djm 1492: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
1493: {
1494: char buf[16];
1495: int len;
1496:
1497: /* Monitor control fd to detect if the slave client exits */
1498: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1499: len = read(c->ctl_fd, buf, sizeof(buf));
1500: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1501: return 1;
1502: if (len <= 0) {
1503: debug2("channel %d: ctl read<=0", c->self);
1504: if (c->type != SSH_CHANNEL_OPEN) {
1505: debug2("channel %d: not open", c->self);
1506: chan_mark_dead(c);
1507: return -1;
1508: } else {
1509: chan_read_failed(c);
1510: chan_write_failed(c);
1511: }
1512: return -1;
1513: } else
1514: fatal("%s: unexpected data on ctl fd", __func__);
1515: }
1516: return 1;
1517: }
1518: static int
1.93 markus 1519: channel_check_window(Channel *c)
1.44 markus 1520: {
1.104 markus 1521: if (c->type == SSH_CHANNEL_OPEN &&
1522: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1523: c->local_window < c->local_window_max/2 &&
1524: c->local_consumed > 0) {
1525: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1526: packet_put_int(c->remote_id);
1527: packet_put_int(c->local_consumed);
1528: packet_send();
1.70 markus 1529: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1530: c->self, c->local_window,
1531: c->local_consumed);
1532: c->local_window += c->local_consumed;
1533: c->local_consumed = 0;
1.1 deraadt 1534: }
1.41 markus 1535: return 1;
1.1 deraadt 1536: }
1537:
1.127 itojun 1538: static void
1.157 markus 1539: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1540: {
1.137 markus 1541: if (c->delayed)
1542: return;
1.41 markus 1543: channel_handle_rfd(c, readset, writeset);
1544: channel_handle_wfd(c, readset, writeset);
1.157 markus 1545: if (!compat20)
1.137 markus 1546: return;
1.44 markus 1547: channel_handle_efd(c, readset, writeset);
1.204 djm 1548: channel_handle_ctl(c, readset, writeset);
1.93 markus 1549: channel_check_window(c);
1.44 markus 1550: }
1551:
1.127 itojun 1552: static void
1.41 markus 1553: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1554: {
1.41 markus 1555: int len;
1.180 deraadt 1556:
1.41 markus 1557: /* Send buffered output data to the socket. */
1558: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1559: len = write(c->sock, buffer_ptr(&c->output),
1560: buffer_len(&c->output));
1561: if (len <= 0)
1.158 markus 1562: buffer_clear(&c->output);
1.41 markus 1563: else
1564: buffer_consume(&c->output, len);
1565: }
1566: }
1.25 markus 1567:
1.127 itojun 1568: static void
1.44 markus 1569: channel_handler_init_20(void)
1570: {
1.157 markus 1571: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1572: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1573: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1574: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1575: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1576: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1577: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1578: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1579:
1.157 markus 1580: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1581: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1582: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1583: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1584: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1585: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1586: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1587: }
1588:
1.127 itojun 1589: static void
1.41 markus 1590: channel_handler_init_13(void)
1591: {
1592: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1593: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1594: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1595: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1596: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1597: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1598: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1599: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1600: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1601:
1.157 markus 1602: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1603: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1604: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1605: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1606: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1607: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1608: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1609: }
1.25 markus 1610:
1.127 itojun 1611: static void
1.41 markus 1612: channel_handler_init_15(void)
1613: {
1.157 markus 1614: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1615: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1616: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1617: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1618: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1619: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1620: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1621:
1.41 markus 1622: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1623: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1624: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1625: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1626: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1627: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1628: }
1.27 markus 1629:
1.127 itojun 1630: static void
1.41 markus 1631: channel_handler_init(void)
1632: {
1633: int i;
1.180 deraadt 1634:
1.148 deraadt 1635: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1636: channel_pre[i] = NULL;
1637: channel_post[i] = NULL;
1638: }
1.44 markus 1639: if (compat20)
1640: channel_handler_init_20();
1641: else if (compat13)
1.41 markus 1642: channel_handler_init_13();
1643: else
1644: channel_handler_init_15();
1645: }
1.25 markus 1646:
1.140 markus 1647: /* gc dead channels */
1648: static void
1649: channel_garbage_collect(Channel *c)
1650: {
1651: if (c == NULL)
1652: return;
1653: if (c->detach_user != NULL) {
1654: if (!chan_is_dead(c, 0))
1655: return;
1.194 markus 1656: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1657: c->detach_user(c->self, NULL);
1658: /* if we still have a callback */
1659: if (c->detach_user != NULL)
1660: return;
1.194 markus 1661: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1662: }
1663: if (!chan_is_dead(c, 1))
1664: return;
1.194 markus 1665: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1666: channel_free(c);
1667: }
1668:
1.127 itojun 1669: static void
1.41 markus 1670: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1671: {
1672: static int did_init = 0;
1.209 avsm 1673: u_int i;
1.41 markus 1674: Channel *c;
1.25 markus 1675:
1.41 markus 1676: if (!did_init) {
1677: channel_handler_init();
1678: did_init = 1;
1679: }
1680: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1681: c = channels[i];
1682: if (c == NULL)
1.41 markus 1683: continue;
1.118 markus 1684: if (ftab[c->type] != NULL)
1685: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1686: channel_garbage_collect(c);
1.1 deraadt 1687: }
1688: }
1689:
1.121 markus 1690: /*
1691: * Allocate/update select bitmasks and add any bits relevant to channels in
1692: * select bitmasks.
1693: */
1.49 markus 1694: void
1.100 markus 1695: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1696: u_int *nallocp, int rekeying)
1.41 markus 1697: {
1.209 avsm 1698: u_int n, sz;
1.84 markus 1699:
1700: n = MAX(*maxfdp, channel_max_fd);
1701:
1702: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1703: /* perhaps check sz < nalloc/2 and shrink? */
1704: if (*readsetp == NULL || sz > *nallocp) {
1705: *readsetp = xrealloc(*readsetp, sz);
1706: *writesetp = xrealloc(*writesetp, sz);
1707: *nallocp = sz;
1.84 markus 1708: }
1.132 markus 1709: *maxfdp = n;
1.84 markus 1710: memset(*readsetp, 0, sz);
1711: memset(*writesetp, 0, sz);
1712:
1.100 markus 1713: if (!rekeying)
1714: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1715: }
1716:
1.121 markus 1717: /*
1718: * After select, perform any appropriate operations for channels which have
1719: * events pending.
1720: */
1.49 markus 1721: void
1.41 markus 1722: channel_after_select(fd_set * readset, fd_set * writeset)
1723: {
1724: channel_handler(channel_post, readset, writeset);
1725: }
1726:
1.121 markus 1727:
1.84 markus 1728: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1729:
1.49 markus 1730: void
1.142 itojun 1731: channel_output_poll(void)
1.1 deraadt 1732: {
1.41 markus 1733: Channel *c;
1.209 avsm 1734: u_int i, len;
1.1 deraadt 1735:
1.25 markus 1736: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1737: c = channels[i];
1738: if (c == NULL)
1739: continue;
1.37 markus 1740:
1.121 markus 1741: /*
1742: * We are only interested in channels that can have buffered
1743: * incoming data.
1744: */
1.37 markus 1745: if (compat13) {
1.41 markus 1746: if (c->type != SSH_CHANNEL_OPEN &&
1747: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1748: continue;
1749: } else {
1.41 markus 1750: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1751: continue;
1752: }
1.46 markus 1753: if (compat20 &&
1754: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1755: /* XXX is this true? */
1.140 markus 1756: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1757: continue;
1758: }
1.25 markus 1759:
1760: /* Get the amount of buffered data for this channel. */
1.93 markus 1761: if ((c->istate == CHAN_INPUT_OPEN ||
1762: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1763: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1764: /*
1765: * Send some data for the other side over the secure
1766: * connection.
1767: */
1.44 markus 1768: if (compat20) {
1769: if (len > c->remote_window)
1770: len = c->remote_window;
1771: if (len > c->remote_maxpacket)
1772: len = c->remote_maxpacket;
1.25 markus 1773: } else {
1.44 markus 1774: if (packet_is_interactive()) {
1775: if (len > 1024)
1776: len = 512;
1777: } else {
1778: /* Keep the packets at reasonable size. */
1779: if (len > packet_get_maxsize()/2)
1780: len = packet_get_maxsize()/2;
1781: }
1.25 markus 1782: }
1.41 markus 1783: if (len > 0) {
1.44 markus 1784: packet_start(compat20 ?
1785: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1786: packet_put_int(c->remote_id);
1787: packet_put_string(buffer_ptr(&c->input), len);
1788: packet_send();
1789: buffer_consume(&c->input, len);
1790: c->remote_window -= len;
1791: }
1792: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1793: if (compat13)
1794: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1795: /*
1796: * input-buffer is empty and read-socket shutdown:
1.172 markus 1797: * tell peer, that we will not send more data: send IEOF.
1798: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1799: */
1.172 markus 1800: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.174 markus 1801: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1802: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1803: else
1804: chan_ibuf_empty(c);
1.25 markus 1805: }
1.44 markus 1806: /* Send extended data, i.e. stderr */
1807: if (compat20 &&
1.172 markus 1808: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1809: c->remote_window > 0 &&
1810: (len = buffer_len(&c->extended)) > 0 &&
1811: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1812: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1813: c->self, c->remote_window, buffer_len(&c->extended),
1814: c->extended_usage);
1.44 markus 1815: if (len > c->remote_window)
1816: len = c->remote_window;
1817: if (len > c->remote_maxpacket)
1818: len = c->remote_maxpacket;
1819: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1820: packet_put_int(c->remote_id);
1821: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1822: packet_put_string(buffer_ptr(&c->extended), len);
1823: packet_send();
1824: buffer_consume(&c->extended, len);
1825: c->remote_window -= len;
1.93 markus 1826: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1827: }
1.25 markus 1828: }
1.1 deraadt 1829: }
1830:
1.121 markus 1831:
1832: /* -- protocol input */
1.1 deraadt 1833:
1.49 markus 1834: void
1.154 markus 1835: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1836: {
1.37 markus 1837: int id;
1.25 markus 1838: char *data;
1.77 markus 1839: u_int data_len;
1.41 markus 1840: Channel *c;
1.25 markus 1841:
1842: /* Get the channel number and verify it. */
1.37 markus 1843: id = packet_get_int();
1.41 markus 1844: c = channel_lookup(id);
1845: if (c == NULL)
1.37 markus 1846: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1847:
1848: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1849: if (c->type != SSH_CHANNEL_OPEN &&
1850: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1851: return;
1852:
1.25 markus 1853: /* Get the data. */
1854: data = packet_get_string(&data_len);
1.200 markus 1855:
1856: /*
1857: * Ignore data for protocol > 1.3 if output end is no longer open.
1858: * For protocol 2 the sending side is reducing its window as it sends
1859: * data, so we must 'fake' consumption of the data in order to ensure
1860: * that window updates are sent back. Otherwise the connection might
1861: * deadlock.
1862: */
1863: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1864: if (compat20) {
1865: c->local_window -= data_len;
1866: c->local_consumed += data_len;
1867: }
1868: xfree(data);
1869: return;
1870: }
1.41 markus 1871:
1.143 deraadt 1872: if (compat20) {
1.44 markus 1873: if (data_len > c->local_maxpacket) {
1.188 itojun 1874: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1875: c->self, data_len, c->local_maxpacket);
1876: }
1877: if (data_len > c->local_window) {
1.188 itojun 1878: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1879: c->self, data_len, c->local_window);
1880: xfree(data);
1881: return;
1882: }
1883: c->local_window -= data_len;
1884: }
1.152 markus 1885: packet_check_eom();
1.41 markus 1886: buffer_append(&c->output, data, data_len);
1.25 markus 1887: xfree(data);
1.1 deraadt 1888: }
1.121 markus 1889:
1.49 markus 1890: void
1.154 markus 1891: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1892: {
1893: int id;
1894: char *data;
1.177 markus 1895: u_int data_len, tcode;
1.44 markus 1896: Channel *c;
1897:
1898: /* Get the channel number and verify it. */
1899: id = packet_get_int();
1900: c = channel_lookup(id);
1901:
1902: if (c == NULL)
1903: packet_disconnect("Received extended_data for bad channel %d.", id);
1904: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 1905: logit("channel %d: ext data for non open", id);
1.44 markus 1906: return;
1.172 markus 1907: }
1908: if (c->flags & CHAN_EOF_RCVD) {
1909: if (datafellows & SSH_BUG_EXTEOF)
1910: debug("channel %d: accepting ext data after eof", id);
1911: else
1912: packet_disconnect("Received extended_data after EOF "
1913: "on channel %d.", id);
1.44 markus 1914: }
1915: tcode = packet_get_int();
1916: if (c->efd == -1 ||
1917: c->extended_usage != CHAN_EXTENDED_WRITE ||
1918: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 1919: logit("channel %d: bad ext data", c->self);
1.44 markus 1920: return;
1921: }
1922: data = packet_get_string(&data_len);
1.152 markus 1923: packet_check_eom();
1.44 markus 1924: if (data_len > c->local_window) {
1.188 itojun 1925: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 1926: c->self, data_len, c->local_window);
1927: xfree(data);
1928: return;
1929: }
1.70 markus 1930: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1931: c->local_window -= data_len;
1932: buffer_append(&c->extended, data, data_len);
1933: xfree(data);
1934: }
1935:
1.49 markus 1936: void
1.154 markus 1937: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1938: {
1939: int id;
1940: Channel *c;
1941:
1942: id = packet_get_int();
1.152 markus 1943: packet_check_eom();
1.41 markus 1944: c = channel_lookup(id);
1945: if (c == NULL)
1946: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1947: chan_rcvd_ieof(c);
1.133 markus 1948:
1949: /* XXX force input close */
1.156 markus 1950: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1951: debug("channel %d: FORCE input drain", c->self);
1952: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1953: if (buffer_len(&c->input) == 0)
1954: chan_ibuf_empty(c);
1.133 markus 1955: }
1956:
1.41 markus 1957: }
1.1 deraadt 1958:
1.49 markus 1959: void
1.154 markus 1960: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1961: {
1.41 markus 1962: int id;
1963: Channel *c;
1.1 deraadt 1964:
1.41 markus 1965: id = packet_get_int();
1.152 markus 1966: packet_check_eom();
1.41 markus 1967: c = channel_lookup(id);
1968: if (c == NULL)
1969: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1970:
1971: /*
1972: * Send a confirmation that we have closed the channel and no more
1973: * data is coming for it.
1974: */
1.25 markus 1975: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1976: packet_put_int(c->remote_id);
1.25 markus 1977: packet_send();
1978:
1.27 markus 1979: /*
1980: * If the channel is in closed state, we have sent a close request,
1981: * and the other side will eventually respond with a confirmation.
1982: * Thus, we cannot free the channel here, because then there would be
1983: * no-one to receive the confirmation. The channel gets freed when
1984: * the confirmation arrives.
1985: */
1.41 markus 1986: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1987: /*
1988: * Not a closed channel - mark it as draining, which will
1989: * cause it to be freed later.
1990: */
1.158 markus 1991: buffer_clear(&c->input);
1.41 markus 1992: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1993: }
1.1 deraadt 1994: }
1995:
1.41 markus 1996: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1997: void
1.154 markus 1998: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1999: {
2000: int id = packet_get_int();
2001: Channel *c = channel_lookup(id);
1.151 markus 2002:
1.152 markus 2003: packet_check_eom();
1.41 markus 2004: if (c == NULL)
2005: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2006: chan_rcvd_oclose(c);
2007: }
1.1 deraadt 2008:
1.49 markus 2009: void
1.154 markus 2010: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2011: {
1.41 markus 2012: int id = packet_get_int();
2013: Channel *c = channel_lookup(id);
1.1 deraadt 2014:
1.152 markus 2015: packet_check_eom();
1.41 markus 2016: if (c == NULL)
2017: packet_disconnect("Received close confirmation for "
2018: "out-of-range channel %d.", id);
2019: if (c->type != SSH_CHANNEL_CLOSED)
2020: packet_disconnect("Received close confirmation for "
2021: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2022: channel_free(c);
1.1 deraadt 2023: }
2024:
1.49 markus 2025: void
1.154 markus 2026: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2027: {
1.41 markus 2028: int id, remote_id;
2029: Channel *c;
1.1 deraadt 2030:
1.41 markus 2031: id = packet_get_int();
2032: c = channel_lookup(id);
1.25 markus 2033:
1.41 markus 2034: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2035: packet_disconnect("Received open confirmation for "
2036: "non-opening channel %d.", id);
2037: remote_id = packet_get_int();
1.27 markus 2038: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2039: c->remote_id = remote_id;
2040: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2041:
2042: if (compat20) {
2043: c->remote_window = packet_get_int();
2044: c->remote_maxpacket = packet_get_int();
1.165 markus 2045: if (c->confirm) {
1.70 markus 2046: debug2("callback start");
1.204 djm 2047: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2048: debug2("callback done");
1.44 markus 2049: }
1.194 markus 2050: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2051: c->remote_window, c->remote_maxpacket);
2052: }
1.152 markus 2053: packet_check_eom();
1.1 deraadt 2054: }
2055:
1.127 itojun 2056: static char *
1.114 markus 2057: reason2txt(int reason)
2058: {
1.143 deraadt 2059: switch (reason) {
1.114 markus 2060: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2061: return "administratively prohibited";
2062: case SSH2_OPEN_CONNECT_FAILED:
2063: return "connect failed";
2064: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2065: return "unknown channel type";
2066: case SSH2_OPEN_RESOURCE_SHORTAGE:
2067: return "resource shortage";
2068: }
1.117 stevesk 2069: return "unknown reason";
1.114 markus 2070: }
2071:
1.49 markus 2072: void
1.154 markus 2073: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2074: {
1.86 markus 2075: int id, reason;
2076: char *msg = NULL, *lang = NULL;
1.41 markus 2077: Channel *c;
2078:
2079: id = packet_get_int();
2080: c = channel_lookup(id);
1.25 markus 2081:
1.41 markus 2082: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2083: packet_disconnect("Received open failure for "
2084: "non-opening channel %d.", id);
1.44 markus 2085: if (compat20) {
1.86 markus 2086: reason = packet_get_int();
1.110 markus 2087: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2088: msg = packet_get_string(NULL);
2089: lang = packet_get_string(NULL);
2090: }
1.188 itojun 2091: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2092: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2093: if (msg != NULL)
2094: xfree(msg);
2095: if (lang != NULL)
2096: xfree(lang);
1.44 markus 2097: }
1.152 markus 2098: packet_check_eom();
1.25 markus 2099: /* Free the channel. This will also close the socket. */
1.113 markus 2100: channel_free(c);
1.44 markus 2101: }
2102:
1.121 markus 2103: void
1.154 markus 2104: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2105: {
2106: Channel *c;
1.178 markus 2107: int id;
2108: u_int adjust;
1.121 markus 2109:
2110: if (!compat20)
2111: return;
2112:
2113: /* Get the channel number and verify it. */
2114: id = packet_get_int();
2115: c = channel_lookup(id);
1.1 deraadt 2116:
1.121 markus 2117: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2118: logit("Received window adjust for "
1.121 markus 2119: "non-open channel %d.", id);
2120: return;
2121: }
2122: adjust = packet_get_int();
1.152 markus 2123: packet_check_eom();
1.178 markus 2124: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2125: c->remote_window += adjust;
2126: }
1.1 deraadt 2127:
1.121 markus 2128: void
1.154 markus 2129: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2130: {
1.121 markus 2131: Channel *c = NULL;
2132: u_short host_port;
2133: char *host, *originator_string;
2134: int remote_id, sock = -1;
2135:
2136: remote_id = packet_get_int();
2137: host = packet_get_string(NULL);
2138: host_port = packet_get_int();
1.25 markus 2139:
1.121 markus 2140: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2141: originator_string = packet_get_string(NULL);
2142: } else {
2143: originator_string = xstrdup("unknown (remote did not supply name)");
2144: }
1.152 markus 2145: packet_check_eom();
1.121 markus 2146: sock = channel_connect_to(host, host_port);
2147: if (sock != -1) {
2148: c = channel_new("connected socket",
2149: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2150: originator_string, 1);
1.167 markus 2151: c->remote_id = remote_id;
1.25 markus 2152: }
1.190 markus 2153: xfree(originator_string);
1.121 markus 2154: if (c == NULL) {
2155: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2156: packet_put_int(remote_id);
2157: packet_send();
2158: }
2159: xfree(host);
1.1 deraadt 2160: }
2161:
1.121 markus 2162:
2163: /* -- tcp forwarding */
1.135 markus 2164:
2165: void
2166: channel_set_af(int af)
2167: {
2168: IPv4or6 = af;
2169: }
1.121 markus 2170:
1.160 markus 2171: static int
2172: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2173: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2174: {
1.113 markus 2175: Channel *c;
1.212 djm 2176: int sock, r, success = 0, on = 1, wildcard = 0, is_client;
1.35 markus 2177: struct addrinfo hints, *ai, *aitop;
1.212 djm 2178: const char *host, *addr;
1.35 markus 2179: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2180:
1.160 markus 2181: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2182: listen_addr : host_to_connect;
1.212 djm 2183: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2184:
1.160 markus 2185: if (host == NULL) {
2186: error("No forward host name.");
2187: return success;
1.73 markus 2188: }
1.113 markus 2189: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2190: error("Forward host name too long.");
2191: return success;
2192: }
1.25 markus 2193:
1.28 markus 2194: /*
1.212 djm 2195: * Determine whether or not a port forward listens to loopback,
1.213 ! deraadt 2196: * specified address or wildcard. On the client, a specified bind
! 2197: * address will always override gateway_ports. On the server, a
! 2198: * gateway_ports of 1 (``yes'') will override the client's
! 2199: * specification and force a wildcard bind, whereas a value of 2
! 2200: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2201: * asked for.
2202: *
2203: * Special-case listen_addrs are:
2204: *
2205: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2206: * "" (empty string), "*" -> wildcard v4/v6
2207: * "localhost" -> loopback v4/v6
2208: */
2209: addr = NULL;
2210: if (listen_addr == NULL) {
2211: /* No address specified: default to gateway_ports setting */
2212: if (gateway_ports)
2213: wildcard = 1;
2214: } else if (gateway_ports || is_client) {
2215: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2216: strcmp(listen_addr, "0.0.0.0") == 0) ||
2217: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2218: (!is_client && gateway_ports == 1))
2219: wildcard = 1;
2220: else if (strcmp(listen_addr, "localhost") != 0)
2221: addr = listen_addr;
2222: }
2223:
2224: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2225: type, wildcard, (addr == NULL) ? "NULL" : addr);
2226:
2227: /*
1.35 markus 2228: * getaddrinfo returns a loopback address if the hostname is
2229: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2230: */
1.35 markus 2231: memset(&hints, 0, sizeof(hints));
2232: hints.ai_family = IPv4or6;
1.212 djm 2233: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2234: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2235: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2236: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2237: if (addr == NULL) {
2238: /* This really shouldn't happen */
2239: packet_disconnect("getaddrinfo: fatal error: %s",
2240: gai_strerror(r));
2241: } else {
2242: verbose("channel_setup_fwd_listener: "
2243: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2244: packet_send_debug("channel_setup_fwd_listener: "
2245: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2246: }
2247: aitop = NULL;
2248: }
1.35 markus 2249:
2250: for (ai = aitop; ai; ai = ai->ai_next) {
2251: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2252: continue;
2253: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2254: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2255: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2256: continue;
2257: }
2258: /* Create a port to listen for the host. */
1.189 markus 2259: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2260: if (sock < 0) {
2261: /* this is no error since kernel may not support ipv6 */
2262: verbose("socket: %.100s", strerror(errno));
2263: continue;
2264: }
2265: /*
1.182 stevesk 2266: * Set socket options.
2267: * Allow local port reuse in TIME_WAIT.
1.35 markus 2268: */
1.182 stevesk 2269: if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
2270: sizeof(on)) == -1)
2271: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
2272:
1.35 markus 2273: debug("Local forwarding listening on %s port %s.", ntop, strport);
2274:
2275: /* Bind the socket to the address. */
2276: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2277: /* address can be in use ipv6 address is already bound */
2278: verbose("bind: %.100s", strerror(errno));
2279: close(sock);
2280: continue;
2281: }
2282: /* Start listening for connections on the socket. */
1.199 markus 2283: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2284: error("listen: %.100s", strerror(errno));
2285: close(sock);
2286: continue;
2287: }
2288: /* Allocate a channel number for the socket. */
1.121 markus 2289: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2290: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2291: 0, "port listener", 1);
1.113 markus 2292: strlcpy(c->path, host, sizeof(c->path));
2293: c->host_port = port_to_connect;
2294: c->listening_port = listen_port;
1.35 markus 2295: success = 1;
2296: }
2297: if (success == 0)
1.160 markus 2298: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2299: listen_port);
1.35 markus 2300: freeaddrinfo(aitop);
1.87 markus 2301: return success;
1.25 markus 2302: }
1.1 deraadt 2303:
1.202 djm 2304: int
2305: channel_cancel_rport_listener(const char *host, u_short port)
2306: {
1.209 avsm 2307: u_int i;
2308: int found = 0;
1.202 djm 2309:
1.213 ! deraadt 2310: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2311: Channel *c = channels[i];
2312:
2313: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2314: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2315: c->listening_port == port) {
1.210 djm 2316: debug2("%s: close channel %d", __func__, i);
1.202 djm 2317: channel_free(c);
2318: found = 1;
2319: }
2320: }
2321:
2322: return (found);
2323: }
2324:
1.160 markus 2325: /* protocol local port fwd, used by ssh (and sshd in v1) */
2326: int
1.212 djm 2327: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2328: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2329: {
2330: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2331: listen_host, listen_port, host_to_connect, port_to_connect,
2332: gateway_ports);
1.160 markus 2333: }
2334:
2335: /* protocol v2 remote port fwd, used by sshd */
2336: int
2337: channel_setup_remote_fwd_listener(const char *listen_address,
2338: u_short listen_port, int gateway_ports)
2339: {
2340: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2341: listen_address, listen_port, NULL, 0, gateway_ports);
2342: }
2343:
1.27 markus 2344: /*
2345: * Initiate forwarding of connections to port "port" on remote host through
2346: * the secure channel to host:port from local side.
2347: */
1.1 deraadt 2348:
1.49 markus 2349: void
1.212 djm 2350: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2351: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2352: {
1.153 markus 2353: int type, success = 0;
1.73 markus 2354:
1.25 markus 2355: /* Record locally that connection to this host/port is permitted. */
2356: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2357: fatal("channel_request_remote_forwarding: too many forwards");
2358:
2359: /* Send the forward request to the remote side. */
1.44 markus 2360: if (compat20) {
1.212 djm 2361: const char *address_to_bind;
2362: if (listen_host == NULL)
2363: address_to_bind = "localhost";
2364: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2365: address_to_bind = "";
2366: else
2367: address_to_bind = listen_host;
2368:
1.44 markus 2369: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2370: packet_put_cstring("tcpip-forward");
1.173 markus 2371: packet_put_char(1); /* boolean: want reply */
1.44 markus 2372: packet_put_cstring(address_to_bind);
2373: packet_put_int(listen_port);
1.73 markus 2374: packet_send();
2375: packet_write_wait();
2376: /* Assume that server accepts the request */
2377: success = 1;
1.44 markus 2378: } else {
2379: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2380: packet_put_int(listen_port);
2381: packet_put_cstring(host_to_connect);
1.44 markus 2382: packet_put_int(port_to_connect);
2383: packet_send();
2384: packet_write_wait();
1.73 markus 2385:
2386: /* Wait for response from the remote side. */
1.153 markus 2387: type = packet_read();
1.73 markus 2388: switch (type) {
2389: case SSH_SMSG_SUCCESS:
2390: success = 1;
2391: break;
2392: case SSH_SMSG_FAILURE:
1.188 itojun 2393: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2394: break;
2395: default:
2396: /* Unknown packet */
2397: packet_disconnect("Protocol error for port forward request:"
2398: "received packet type %d.", type);
2399: }
2400: }
2401: if (success) {
2402: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2403: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2404: permitted_opens[num_permitted_opens].listen_port = listen_port;
2405: num_permitted_opens++;
1.44 markus 2406: }
1.1 deraadt 2407: }
2408:
1.27 markus 2409: /*
1.208 deraadt 2410: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2411: * local side.
2412: */
2413: void
1.212 djm 2414: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2415: {
2416: int i;
2417:
2418: if (!compat20)
2419: return;
2420:
2421: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2422: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2423: permitted_opens[i].listen_port == port)
2424: break;
2425: }
2426: if (i >= num_permitted_opens) {
2427: debug("%s: requested forward not found", __func__);
2428: return;
2429: }
2430: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2431: packet_put_cstring("cancel-tcpip-forward");
2432: packet_put_char(0);
1.212 djm 2433: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2434: packet_put_int(port);
2435: packet_send();
2436:
2437: permitted_opens[i].listen_port = 0;
2438: permitted_opens[i].port_to_connect = 0;
2439: free(permitted_opens[i].host_to_connect);
2440: permitted_opens[i].host_to_connect = NULL;
2441: }
2442:
2443: /*
1.27 markus 2444: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2445: * listening for the port, and sends back a success reply (or disconnect
2446: * message if there was an error). This never returns if there was an error.
2447: */
1.1 deraadt 2448:
1.49 markus 2449: void
1.56 markus 2450: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2451: {
1.31 markus 2452: u_short port, host_port;
1.25 markus 2453: char *hostname;
1.1 deraadt 2454:
1.25 markus 2455: /* Get arguments from the packet. */
2456: port = packet_get_int();
2457: hostname = packet_get_string(NULL);
2458: host_port = packet_get_int();
2459:
1.27 markus 2460: /*
2461: * Check that an unprivileged user is not trying to forward a
2462: * privileged port.
2463: */
1.25 markus 2464: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2465: packet_disconnect(
2466: "Requested forwarding of port %d but user is not root.",
2467: port);
2468: if (host_port == 0)
2469: packet_disconnect("Dynamic forwarding denied.");
2470:
1.73 markus 2471: /* Initiate forwarding */
1.212 djm 2472: channel_setup_local_fwd_listener(NULL, port, hostname,
2473: host_port, gateway_ports);
1.25 markus 2474:
2475: /* Free the argument string. */
2476: xfree(hostname);
1.1 deraadt 2477: }
2478:
1.99 markus 2479: /*
2480: * Permits opening to any host/port if permitted_opens[] is empty. This is
2481: * usually called by the server, because the user could connect to any port
2482: * anyway, and the server has no way to know but to trust the client anyway.
2483: */
2484: void
1.142 itojun 2485: channel_permit_all_opens(void)
1.99 markus 2486: {
2487: if (num_permitted_opens == 0)
2488: all_opens_permitted = 1;
2489: }
2490:
1.101 markus 2491: void
1.99 markus 2492: channel_add_permitted_opens(char *host, int port)
2493: {
2494: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2495: fatal("channel_request_remote_forwarding: too many forwards");
2496: debug("allow port forwarding to host %s port %d", host, port);
2497:
2498: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2499: permitted_opens[num_permitted_opens].port_to_connect = port;
2500: num_permitted_opens++;
2501:
2502: all_opens_permitted = 0;
2503: }
2504:
1.101 markus 2505: void
1.99 markus 2506: channel_clear_permitted_opens(void)
2507: {
2508: int i;
2509:
2510: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2511: if (permitted_opens[i].host_to_connect != NULL)
2512: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2513: num_permitted_opens = 0;
2514:
2515: }
2516:
2517:
2518: /* return socket to remote host, port */
1.127 itojun 2519: static int
1.99 markus 2520: connect_to(const char *host, u_short port)
1.41 markus 2521: {
2522: struct addrinfo hints, *ai, *aitop;
2523: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2524: int gaierr;
2525: int sock = -1;
2526:
2527: memset(&hints, 0, sizeof(hints));
2528: hints.ai_family = IPv4or6;
2529: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2530: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2531: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2532: error("connect_to %.100s: unknown host (%s)", host,
2533: gai_strerror(gaierr));
1.41 markus 2534: return -1;
2535: }
2536: for (ai = aitop; ai; ai = ai->ai_next) {
2537: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2538: continue;
2539: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2540: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2541: error("connect_to: getnameinfo failed");
1.41 markus 2542: continue;
2543: }
1.189 markus 2544: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2545: if (sock < 0) {
1.186 djm 2546: if (ai->ai_next == NULL)
2547: error("socket: %.100s", strerror(errno));
2548: else
2549: verbose("socket: %.100s", strerror(errno));
1.41 markus 2550: continue;
2551: }
1.205 djm 2552: if (set_nonblock(sock) == -1)
2553: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2554: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2555: errno != EINPROGRESS) {
1.99 markus 2556: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2557: strerror(errno));
2558: close(sock);
1.89 stevesk 2559: continue; /* fail -- try next */
1.41 markus 2560: }
2561: break; /* success */
2562:
2563: }
2564: freeaddrinfo(aitop);
2565: if (!ai) {
1.99 markus 2566: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2567: return -1;
2568: }
2569: /* success */
1.169 stevesk 2570: set_nodelay(sock);
1.41 markus 2571: return sock;
2572: }
1.99 markus 2573:
1.73 markus 2574: int
1.130 stevesk 2575: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2576: {
2577: int i;
1.99 markus 2578:
1.73 markus 2579: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2580: if (permitted_opens[i].host_to_connect != NULL &&
2581: permitted_opens[i].listen_port == listen_port)
1.99 markus 2582: return connect_to(
1.73 markus 2583: permitted_opens[i].host_to_connect,
2584: permitted_opens[i].port_to_connect);
1.74 markus 2585: error("WARNING: Server requests forwarding for unknown listen_port %d",
2586: listen_port);
1.73 markus 2587: return -1;
2588: }
2589:
1.99 markus 2590: /* Check if connecting to that port is permitted and connect. */
2591: int
2592: channel_connect_to(const char *host, u_short port)
2593: {
2594: int i, permit;
2595:
2596: permit = all_opens_permitted;
2597: if (!permit) {
2598: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2599: if (permitted_opens[i].host_to_connect != NULL &&
2600: permitted_opens[i].port_to_connect == port &&
1.99 markus 2601: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2602: permit = 1;
2603:
2604: }
2605: if (!permit) {
1.188 itojun 2606: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2607: "but the request was denied.", host, port);
2608: return -1;
2609: }
2610: return connect_to(host, port);
1.204 djm 2611: }
2612:
2613: void
2614: channel_send_window_changes(void)
2615: {
1.209 avsm 2616: u_int i;
1.204 djm 2617: struct winsize ws;
2618:
2619: for (i = 0; i < channels_alloc; i++) {
1.213 ! deraadt 2620: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2621: channels[i]->type != SSH_CHANNEL_OPEN)
2622: continue;
2623: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2624: continue;
2625: channel_request_start(i, "window-change", 0);
2626: packet_put_int(ws.ws_col);
2627: packet_put_int(ws.ws_row);
2628: packet_put_int(ws.ws_xpixel);
2629: packet_put_int(ws.ws_ypixel);
2630: packet_send();
2631: }
1.99 markus 2632: }
2633:
1.121 markus 2634: /* -- X11 forwarding */
1.1 deraadt 2635:
1.27 markus 2636: /*
2637: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2638: * Returns 0 and a suitable display number for the DISPLAY variable
2639: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2640: */
1.141 stevesk 2641: int
1.163 stevesk 2642: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.176 deraadt 2643: int single_connection, u_int *display_numberp)
1.1 deraadt 2644: {
1.149 markus 2645: Channel *nc = NULL;
1.31 markus 2646: int display_number, sock;
2647: u_short port;
1.35 markus 2648: struct addrinfo hints, *ai, *aitop;
2649: char strport[NI_MAXSERV];
2650: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2651:
1.33 markus 2652: for (display_number = x11_display_offset;
1.148 deraadt 2653: display_number < MAX_DISPLAYS;
2654: display_number++) {
1.25 markus 2655: port = 6000 + display_number;
1.35 markus 2656: memset(&hints, 0, sizeof(hints));
2657: hints.ai_family = IPv4or6;
1.163 stevesk 2658: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2659: hints.ai_socktype = SOCK_STREAM;
2660: snprintf(strport, sizeof strport, "%d", port);
2661: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2662: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2663: return -1;
1.25 markus 2664: }
1.35 markus 2665: for (ai = aitop; ai; ai = ai->ai_next) {
2666: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2667: continue;
1.189 markus 2668: sock = socket(ai->ai_family, ai->ai_socktype,
2669: ai->ai_protocol);
1.35 markus 2670: if (sock < 0) {
2671: error("socket: %.100s", strerror(errno));
1.203 markus 2672: freeaddrinfo(aitop);
1.141 stevesk 2673: return -1;
1.35 markus 2674: }
2675: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2676: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2677: close(sock);
1.183 itojun 2678:
2679: if (ai->ai_next)
2680: continue;
2681:
1.35 markus 2682: for (n = 0; n < num_socks; n++) {
2683: close(socks[n]);
2684: }
2685: num_socks = 0;
2686: break;
2687: }
2688: socks[num_socks++] = sock;
2689: if (num_socks == NUM_SOCKS)
2690: break;
1.25 markus 2691: }
1.83 stevesk 2692: freeaddrinfo(aitop);
1.35 markus 2693: if (num_socks > 0)
2694: break;
1.25 markus 2695: }
2696: if (display_number >= MAX_DISPLAYS) {
2697: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2698: return -1;
1.25 markus 2699: }
2700: /* Start listening for connections on the socket. */
1.35 markus 2701: for (n = 0; n < num_socks; n++) {
2702: sock = socks[n];
1.199 markus 2703: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2704: error("listen: %.100s", strerror(errno));
2705: close(sock);
1.141 stevesk 2706: return -1;
1.35 markus 2707: }
1.25 markus 2708: }
1.35 markus 2709:
2710: /* Allocate a channel for each socket. */
2711: for (n = 0; n < num_socks; n++) {
2712: sock = socks[n];
1.149 markus 2713: nc = channel_new("x11 listener",
1.51 markus 2714: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2715: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2716: 0, "X11 inet listener", 1);
1.167 markus 2717: nc->single_connection = single_connection;
1.35 markus 2718: }
1.1 deraadt 2719:
1.141 stevesk 2720: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2721: *display_numberp = display_number;
2722: return (0);
1.1 deraadt 2723: }
2724:
1.127 itojun 2725: static int
1.77 markus 2726: connect_local_xsocket(u_int dnr)
1.1 deraadt 2727: {
1.25 markus 2728: int sock;
2729: struct sockaddr_un addr;
2730:
1.147 stevesk 2731: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2732: if (sock < 0)
2733: error("socket: %.100s", strerror(errno));
2734: memset(&addr, 0, sizeof(addr));
2735: addr.sun_family = AF_UNIX;
2736: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2737: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2738: return sock;
2739: close(sock);
1.25 markus 2740: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2741: return -1;
1.1 deraadt 2742: }
2743:
1.51 markus 2744: int
2745: x11_connect_display(void)
1.1 deraadt 2746: {
1.162 stevesk 2747: int display_number, sock = 0;
1.25 markus 2748: const char *display;
1.51 markus 2749: char buf[1024], *cp;
1.35 markus 2750: struct addrinfo hints, *ai, *aitop;
2751: char strport[NI_MAXSERV];
2752: int gaierr;
1.25 markus 2753:
2754: /* Try to open a socket for the local X server. */
2755: display = getenv("DISPLAY");
2756: if (!display) {
2757: error("DISPLAY not set.");
1.51 markus 2758: return -1;
1.25 markus 2759: }
1.27 markus 2760: /*
2761: * Now we decode the value of the DISPLAY variable and make a
2762: * connection to the real X server.
2763: */
2764:
2765: /*
2766: * Check if it is a unix domain socket. Unix domain displays are in
2767: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2768: */
1.25 markus 2769: if (strncmp(display, "unix:", 5) == 0 ||
2770: display[0] == ':') {
2771: /* Connect to the unix domain socket. */
2772: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2773: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2774: display);
1.51 markus 2775: return -1;
1.25 markus 2776: }
2777: /* Create a socket. */
2778: sock = connect_local_xsocket(display_number);
2779: if (sock < 0)
1.51 markus 2780: return -1;
1.25 markus 2781:
2782: /* OK, we now have a connection to the display. */
1.51 markus 2783: return sock;
1.25 markus 2784: }
1.27 markus 2785: /*
2786: * Connect to an inet socket. The DISPLAY value is supposedly
2787: * hostname:d[.s], where hostname may also be numeric IP address.
2788: */
1.145 stevesk 2789: strlcpy(buf, display, sizeof(buf));
1.25 markus 2790: cp = strchr(buf, ':');
2791: if (!cp) {
2792: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2793: return -1;
1.25 markus 2794: }
2795: *cp = 0;
1.27 markus 2796: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2797: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2798: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2799: display);
1.51 markus 2800: return -1;
1.25 markus 2801: }
1.35 markus 2802:
2803: /* Look up the host address */
2804: memset(&hints, 0, sizeof(hints));
2805: hints.ai_family = IPv4or6;
2806: hints.ai_socktype = SOCK_STREAM;
2807: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2808: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2809: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2810: return -1;
1.25 markus 2811: }
1.35 markus 2812: for (ai = aitop; ai; ai = ai->ai_next) {
2813: /* Create a socket. */
1.189 markus 2814: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2815: if (sock < 0) {
1.194 markus 2816: debug2("socket: %.100s", strerror(errno));
1.41 markus 2817: continue;
2818: }
2819: /* Connect it to the display. */
2820: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2821: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2822: 6000 + display_number, strerror(errno));
2823: close(sock);
2824: continue;
2825: }
2826: /* Success */
2827: break;
1.35 markus 2828: }
2829: freeaddrinfo(aitop);
2830: if (!ai) {
1.49 markus 2831: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2832: strerror(errno));
1.51 markus 2833: return -1;
1.25 markus 2834: }
1.162 stevesk 2835: set_nodelay(sock);
1.51 markus 2836: return sock;
2837: }
2838:
2839: /*
2840: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2841: * the remote channel number. We should do whatever we want, and respond
2842: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2843: */
2844:
2845: void
1.154 markus 2846: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2847: {
1.113 markus 2848: Channel *c = NULL;
2849: int remote_id, sock = 0;
1.51 markus 2850: char *remote_host;
1.25 markus 2851:
1.113 markus 2852: debug("Received X11 open request.");
1.51 markus 2853:
1.113 markus 2854: remote_id = packet_get_int();
1.121 markus 2855:
2856: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2857: remote_host = packet_get_string(NULL);
1.51 markus 2858: } else {
2859: remote_host = xstrdup("unknown (remote did not supply name)");
2860: }
1.152 markus 2861: packet_check_eom();
1.25 markus 2862:
1.51 markus 2863: /* Obtain a connection to the real X display. */
2864: sock = x11_connect_display();
1.113 markus 2865: if (sock != -1) {
2866: /* Allocate a channel for this connection. */
2867: c = channel_new("connected x11 socket",
2868: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2869: remote_host, 1);
1.167 markus 2870: c->remote_id = remote_id;
2871: c->force_drain = 1;
1.113 markus 2872: }
1.190 markus 2873: xfree(remote_host);
1.113 markus 2874: if (c == NULL) {
1.51 markus 2875: /* Send refusal to the remote host. */
2876: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2877: packet_put_int(remote_id);
1.51 markus 2878: } else {
2879: /* Send a confirmation to the remote host. */
2880: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2881: packet_put_int(remote_id);
2882: packet_put_int(c->self);
1.51 markus 2883: }
1.113 markus 2884: packet_send();
1.72 markus 2885: }
2886:
2887: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2888: void
1.154 markus 2889: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2890: {
2891: int rchan = packet_get_int();
1.180 deraadt 2892:
1.143 deraadt 2893: switch (type) {
1.72 markus 2894: case SSH_SMSG_AGENT_OPEN:
2895: error("Warning: ssh server tried agent forwarding.");
2896: break;
2897: case SSH_SMSG_X11_OPEN:
2898: error("Warning: ssh server tried X11 forwarding.");
2899: break;
2900: default:
1.154 markus 2901: error("deny_input_open: type %d", type);
1.72 markus 2902: break;
2903: }
2904: error("Warning: this is probably a break in attempt by a malicious server.");
2905: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2906: packet_put_int(rchan);
2907: packet_send();
1.1 deraadt 2908: }
2909:
1.27 markus 2910: /*
2911: * Requests forwarding of X11 connections, generates fake authentication
2912: * data, and enables authentication spoofing.
1.121 markus 2913: * This should be called in the client only.
1.27 markus 2914: */
1.49 markus 2915: void
1.51 markus 2916: x11_request_forwarding_with_spoofing(int client_session_id,
2917: const char *proto, const char *data)
1.1 deraadt 2918: {
1.77 markus 2919: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2920: u_int i, value, len;
1.25 markus 2921: char *new_data;
2922: int screen_number;
2923: const char *cp;
1.207 avsm 2924: u_int32_t rnd = 0;
1.25 markus 2925:
2926: cp = getenv("DISPLAY");
2927: if (cp)
2928: cp = strchr(cp, ':');
2929: if (cp)
2930: cp = strchr(cp, '.');
2931: if (cp)
2932: screen_number = atoi(cp + 1);
2933: else
2934: screen_number = 0;
2935:
2936: /* Save protocol name. */
2937: x11_saved_proto = xstrdup(proto);
2938:
1.27 markus 2939: /*
2940: * Extract real authentication data and generate fake data of the
2941: * same length.
2942: */
1.25 markus 2943: x11_saved_data = xmalloc(data_len);
2944: x11_fake_data = xmalloc(data_len);
2945: for (i = 0; i < data_len; i++) {
2946: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2947: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2948: if (i % 4 == 0)
1.207 avsm 2949: rnd = arc4random();
1.25 markus 2950: x11_saved_data[i] = value;
1.207 avsm 2951: x11_fake_data[i] = rnd & 0xff;
2952: rnd >>= 8;
1.25 markus 2953: }
2954: x11_saved_data_len = data_len;
2955: x11_fake_data_len = data_len;
2956:
2957: /* Convert the fake data into hex. */
1.90 markus 2958: len = 2 * data_len + 1;
2959: new_data = xmalloc(len);
1.25 markus 2960: for (i = 0; i < data_len; i++)
1.90 markus 2961: snprintf(new_data + 2 * i, len - 2 * i,
2962: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2963:
2964: /* Send the request packet. */
1.51 markus 2965: if (compat20) {
2966: channel_request_start(client_session_id, "x11-req", 0);
2967: packet_put_char(0); /* XXX bool single connection */
2968: } else {
2969: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2970: }
2971: packet_put_cstring(proto);
2972: packet_put_cstring(new_data);
1.25 markus 2973: packet_put_int(screen_number);
2974: packet_send();
2975: packet_write_wait();
2976: xfree(new_data);
1.1 deraadt 2977: }
2978:
1.121 markus 2979:
2980: /* -- agent forwarding */
2981:
1.1 deraadt 2982: /* Sends a message to the server to request authentication fd forwarding. */
2983:
1.49 markus 2984: void
1.142 itojun 2985: auth_request_forwarding(void)
1.1 deraadt 2986: {
1.25 markus 2987: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2988: packet_send();
2989: packet_write_wait();
1.1 deraadt 2990: }
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