Annotation of src/usr.bin/ssh/channels.c, Revision 1.176
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"
1.176 ! deraadt 42: RCSID("$OpenBSD: channels.c,v 1.175 2002/06/10 22:28:41 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.h"
1.44 markus 57:
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: */
1.1 deraadt 71: static int channels_alloc = 0;
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:
1.171 markus 144: if (id < 0 || id >= channels_alloc) {
1.41 markus 145: log("channel_lookup: %d: bad id", id);
146: return NULL;
147: }
1.113 markus 148: c = channels[id];
149: if (c == NULL) {
1.41 markus 150: log("channel_lookup: %d: bad id: channel free", id);
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;
175: c->efd = efd;
176: c->extended_usage = extusage;
1.71 markus 177:
1.91 markus 178: /* XXX ugly hack: nonblock is only set by the server */
179: if (nonblock && isatty(c->rfd)) {
1.94 markus 180: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 181: c->isatty = 1;
182: if (!isatty(c->wfd)) {
1.94 markus 183: error("channel %d: wfd %d is not a tty?",
1.91 markus 184: c->self, c->wfd);
185: }
186: } else {
187: c->isatty = 0;
188: }
189:
1.71 markus 190: /* enable nonblocking mode */
191: if (nonblock) {
192: if (rfd != -1)
193: set_nonblock(rfd);
194: if (wfd != -1)
195: set_nonblock(wfd);
196: if (efd != -1)
197: set_nonblock(efd);
198: }
1.52 markus 199: }
200:
201: /*
202: * Allocate a new channel object and set its type and socket. This will cause
203: * remote_name to be freed.
204: */
205:
1.113 markus 206: Channel *
1.52 markus 207: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 208: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 209: {
210: int i, found;
211: Channel *c;
1.25 markus 212:
213: /* Do initial allocation if this is the first call. */
214: if (channels_alloc == 0) {
215: channels_alloc = 10;
1.113 markus 216: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 217: for (i = 0; i < channels_alloc; i++)
1.113 markus 218: channels[i] = NULL;
1.126 markus 219: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 220: }
221: /* Try to find a free slot where to put the new channel. */
222: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 223: if (channels[i] == NULL) {
1.25 markus 224: /* Found a free slot. */
225: found = i;
226: break;
227: }
228: if (found == -1) {
1.27 markus 229: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 230: found = channels_alloc;
231: channels_alloc += 10;
1.70 markus 232: debug2("channel: expanding %d", channels_alloc);
1.113 markus 233: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 234: for (i = found; i < channels_alloc; i++)
1.113 markus 235: channels[i] = NULL;
1.25 markus 236: }
1.113 markus 237: /* Initialize and return new channel. */
238: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 239: memset(c, 0, sizeof(Channel));
1.25 markus 240: buffer_init(&c->input);
241: buffer_init(&c->output);
1.41 markus 242: buffer_init(&c->extended);
1.159 markus 243: c->ostate = CHAN_OUTPUT_OPEN;
244: c->istate = CHAN_INPUT_OPEN;
245: c->flags = 0;
1.71 markus 246: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 247: c->self = found;
248: c->type = type;
1.41 markus 249: c->ctype = ctype;
1.51 markus 250: c->local_window = window;
251: c->local_window_max = window;
252: c->local_consumed = 0;
253: c->local_maxpacket = maxpack;
1.25 markus 254: c->remote_id = -1;
255: c->remote_name = remote_name;
1.41 markus 256: c->remote_window = 0;
257: c->remote_maxpacket = 0;
1.133 markus 258: c->force_drain = 0;
1.149 markus 259: c->single_connection = 0;
1.131 markus 260: c->detach_user = NULL;
1.165 markus 261: c->confirm = NULL;
1.65 markus 262: c->input_filter = NULL;
1.25 markus 263: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 264: return c;
1.1 deraadt 265: }
1.52 markus 266:
1.132 markus 267: static int
268: channel_find_maxfd(void)
269: {
270: int i, max = 0;
271: Channel *c;
272:
273: for (i = 0; i < channels_alloc; i++) {
274: c = channels[i];
275: if (c != NULL) {
276: max = MAX(max, c->rfd);
277: max = MAX(max, c->wfd);
278: max = MAX(max, c->efd);
279: }
280: }
281: return max;
282: }
283:
284: int
285: channel_close_fd(int *fdp)
286: {
287: int ret = 0, fd = *fdp;
288:
289: if (fd != -1) {
290: ret = close(fd);
291: *fdp = -1;
292: if (fd == channel_max_fd)
293: channel_max_fd = channel_find_maxfd();
294: }
295: return ret;
296: }
297:
1.52 markus 298: /* Close all channel fd/socket. */
299:
1.127 itojun 300: static void
1.52 markus 301: channel_close_fds(Channel *c)
302: {
1.118 markus 303: debug3("channel_close_fds: channel %d: r %d w %d e %d",
304: c->self, c->rfd, c->wfd, c->efd);
305:
1.132 markus 306: channel_close_fd(&c->sock);
307: channel_close_fd(&c->rfd);
308: channel_close_fd(&c->wfd);
309: channel_close_fd(&c->efd);
1.121 markus 310: }
311:
312: /* Free the channel and close its fd/socket. */
313:
314: void
315: channel_free(Channel *c)
316: {
317: char *s;
318: int i, n;
319:
320: for (n = 0, i = 0; i < channels_alloc; i++)
321: if (channels[i])
322: n++;
323: debug("channel_free: channel %d: %s, nchannels %d", c->self,
324: c->remote_name ? c->remote_name : "???", n);
325:
326: s = channel_open_message();
327: debug3("channel_free: status: %s", s);
328: xfree(s);
329:
330: if (c->sock != -1)
331: shutdown(c->sock, SHUT_RDWR);
332: channel_close_fds(c);
333: buffer_free(&c->input);
334: buffer_free(&c->output);
335: buffer_free(&c->extended);
336: if (c->remote_name) {
337: xfree(c->remote_name);
338: c->remote_name = NULL;
339: }
340: channels[c->self] = NULL;
341: xfree(c);
342: }
343:
344: void
1.126 markus 345: channel_free_all(void)
1.121 markus 346: {
347: int i;
348:
1.126 markus 349: for (i = 0; i < channels_alloc; i++)
350: if (channels[i] != NULL)
351: channel_free(channels[i]);
1.131 markus 352: }
353:
1.121 markus 354: /*
355: * Closes the sockets/fds of all channels. This is used to close extra file
356: * descriptors after a fork.
357: */
358:
359: void
1.142 itojun 360: channel_close_all(void)
1.121 markus 361: {
362: int i;
363:
364: for (i = 0; i < channels_alloc; i++)
365: if (channels[i] != NULL)
366: channel_close_fds(channels[i]);
367: }
368:
369: /*
1.131 markus 370: * Stop listening to channels.
371: */
372:
373: void
374: channel_stop_listening(void)
375: {
376: int i;
377: Channel *c;
378:
379: for (i = 0; i < channels_alloc; i++) {
380: c = channels[i];
381: if (c != NULL) {
382: switch (c->type) {
383: case SSH_CHANNEL_AUTH_SOCKET:
384: case SSH_CHANNEL_PORT_LISTENER:
385: case SSH_CHANNEL_RPORT_LISTENER:
386: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 387: channel_close_fd(&c->sock);
1.131 markus 388: channel_free(c);
389: break;
390: }
391: }
392: }
393: }
394:
395: /*
1.121 markus 396: * Returns true if no channel has too much buffered data, and false if one or
397: * more channel is overfull.
398: */
399:
400: int
1.142 itojun 401: channel_not_very_much_buffered_data(void)
1.121 markus 402: {
403: u_int i;
404: Channel *c;
405:
406: for (i = 0; i < channels_alloc; i++) {
407: c = channels[i];
408: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 409: #if 0
410: if (!compat20 &&
411: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 412: debug("channel %d: big input buffer %d",
413: c->self, buffer_len(&c->input));
414: return 0;
415: }
1.136 markus 416: #endif
1.121 markus 417: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 418: debug("channel %d: big output buffer %d > %d",
419: c->self, buffer_len(&c->output),
420: packet_get_maxsize());
1.121 markus 421: return 0;
422: }
423: }
424: }
425: return 1;
426: }
427:
428: /* Returns true if any channel is still open. */
429:
430: int
1.142 itojun 431: channel_still_open(void)
1.121 markus 432: {
433: int i;
434: Channel *c;
435:
436: for (i = 0; i < channels_alloc; i++) {
437: c = channels[i];
438: if (c == NULL)
439: continue;
440: switch (c->type) {
441: case SSH_CHANNEL_X11_LISTENER:
442: case SSH_CHANNEL_PORT_LISTENER:
443: case SSH_CHANNEL_RPORT_LISTENER:
444: case SSH_CHANNEL_CLOSED:
445: case SSH_CHANNEL_AUTH_SOCKET:
446: case SSH_CHANNEL_DYNAMIC:
447: case SSH_CHANNEL_CONNECTING:
448: case SSH_CHANNEL_ZOMBIE:
449: continue;
450: case SSH_CHANNEL_LARVAL:
451: if (!compat20)
452: fatal("cannot happen: SSH_CHANNEL_LARVAL");
453: continue;
454: case SSH_CHANNEL_OPENING:
455: case SSH_CHANNEL_OPEN:
456: case SSH_CHANNEL_X11_OPEN:
457: return 1;
458: case SSH_CHANNEL_INPUT_DRAINING:
459: case SSH_CHANNEL_OUTPUT_DRAINING:
460: if (!compat13)
461: fatal("cannot happen: OUT_DRAIN");
462: return 1;
463: default:
464: fatal("channel_still_open: bad channel type %d", c->type);
465: /* NOTREACHED */
466: }
467: }
468: return 0;
469: }
470:
471: /* Returns the id of an open channel suitable for keepaliving */
472:
473: int
1.142 itojun 474: channel_find_open(void)
1.121 markus 475: {
476: int i;
477: Channel *c;
478:
479: for (i = 0; i < channels_alloc; i++) {
480: c = channels[i];
481: if (c == NULL)
482: continue;
483: switch (c->type) {
484: case SSH_CHANNEL_CLOSED:
485: case SSH_CHANNEL_DYNAMIC:
486: case SSH_CHANNEL_X11_LISTENER:
487: case SSH_CHANNEL_PORT_LISTENER:
488: case SSH_CHANNEL_RPORT_LISTENER:
489: case SSH_CHANNEL_OPENING:
490: case SSH_CHANNEL_CONNECTING:
491: case SSH_CHANNEL_ZOMBIE:
492: continue;
493: case SSH_CHANNEL_LARVAL:
494: case SSH_CHANNEL_AUTH_SOCKET:
495: case SSH_CHANNEL_OPEN:
496: case SSH_CHANNEL_X11_OPEN:
497: return i;
498: case SSH_CHANNEL_INPUT_DRAINING:
499: case SSH_CHANNEL_OUTPUT_DRAINING:
500: if (!compat13)
501: fatal("cannot happen: OUT_DRAIN");
502: return i;
503: default:
504: fatal("channel_find_open: bad channel type %d", c->type);
505: /* NOTREACHED */
506: }
507: }
508: return -1;
509: }
510:
511:
512: /*
513: * Returns a message describing the currently open forwarded connections,
514: * suitable for sending to the client. The message contains crlf pairs for
515: * newlines.
516: */
517:
518: char *
1.142 itojun 519: channel_open_message(void)
1.121 markus 520: {
521: Buffer buffer;
522: Channel *c;
523: char buf[1024], *cp;
524: int i;
525:
526: buffer_init(&buffer);
527: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
528: buffer_append(&buffer, buf, strlen(buf));
529: for (i = 0; i < channels_alloc; i++) {
530: c = channels[i];
531: if (c == NULL)
532: continue;
533: switch (c->type) {
534: case SSH_CHANNEL_X11_LISTENER:
535: case SSH_CHANNEL_PORT_LISTENER:
536: case SSH_CHANNEL_RPORT_LISTENER:
537: case SSH_CHANNEL_CLOSED:
538: case SSH_CHANNEL_AUTH_SOCKET:
539: case SSH_CHANNEL_ZOMBIE:
540: continue;
541: case SSH_CHANNEL_LARVAL:
542: case SSH_CHANNEL_OPENING:
543: case SSH_CHANNEL_CONNECTING:
544: case SSH_CHANNEL_DYNAMIC:
545: case SSH_CHANNEL_OPEN:
546: case SSH_CHANNEL_X11_OPEN:
547: case SSH_CHANNEL_INPUT_DRAINING:
548: case SSH_CHANNEL_OUTPUT_DRAINING:
549: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
550: c->self, c->remote_name,
551: c->type, c->remote_id,
552: c->istate, buffer_len(&c->input),
553: c->ostate, buffer_len(&c->output),
554: c->rfd, c->wfd);
555: buffer_append(&buffer, buf, strlen(buf));
556: continue;
557: default:
558: fatal("channel_open_message: bad channel type %d", c->type);
559: /* NOTREACHED */
560: }
561: }
562: buffer_append(&buffer, "\0", 1);
563: cp = xstrdup(buffer_ptr(&buffer));
564: buffer_free(&buffer);
565: return cp;
566: }
567:
568: void
569: channel_send_open(int id)
570: {
571: Channel *c = channel_lookup(id);
572: if (c == NULL) {
573: log("channel_send_open: %d: bad id", id);
574: return;
575: }
576: debug("send channel open %d", id);
577: packet_start(SSH2_MSG_CHANNEL_OPEN);
578: packet_put_cstring(c->ctype);
579: packet_put_int(c->self);
580: packet_put_int(c->local_window);
581: packet_put_int(c->local_maxpacket);
582: packet_send();
583: }
584:
585: void
1.166 markus 586: channel_request_start(int local_id, char *service, int wantconfirm)
1.121 markus 587: {
1.166 markus 588: Channel *c = channel_lookup(local_id);
1.121 markus 589: if (c == NULL) {
1.166 markus 590: log("channel_request_start: %d: unknown channel id", local_id);
1.121 markus 591: return;
592: }
1.166 markus 593: debug("channel request %d: %s", local_id, service) ;
1.121 markus 594: packet_start(SSH2_MSG_CHANNEL_REQUEST);
595: packet_put_int(c->remote_id);
596: packet_put_cstring(service);
597: packet_put_char(wantconfirm);
598: }
599: void
1.165 markus 600: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 601: {
602: Channel *c = channel_lookup(id);
603: if (c == NULL) {
1.165 markus 604: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 605: return;
606: }
1.165 markus 607: c->confirm = fn;
1.121 markus 608: }
609: void
610: channel_register_cleanup(int id, channel_callback_fn *fn)
611: {
612: Channel *c = channel_lookup(id);
613: if (c == NULL) {
614: log("channel_register_cleanup: %d: bad id", id);
615: return;
616: }
1.131 markus 617: c->detach_user = fn;
1.121 markus 618: }
619: void
620: channel_cancel_cleanup(int id)
621: {
622: Channel *c = channel_lookup(id);
623: if (c == NULL) {
624: log("channel_cancel_cleanup: %d: bad id", id);
625: return;
1.52 markus 626: }
1.131 markus 627: c->detach_user = NULL;
1.121 markus 628: }
629: void
630: channel_register_filter(int id, channel_filter_fn *fn)
631: {
632: Channel *c = channel_lookup(id);
633: if (c == NULL) {
634: log("channel_register_filter: %d: bad id", id);
635: return;
1.52 markus 636: }
1.121 markus 637: c->input_filter = fn;
1.52 markus 638: }
639:
1.49 markus 640: void
1.121 markus 641: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 642: int extusage, int nonblock, u_int window_max)
1.1 deraadt 643: {
1.121 markus 644: Channel *c = channel_lookup(id);
645: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
646: fatal("channel_activate for non-larval channel %d.", id);
647: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
648: c->type = SSH_CHANNEL_OPEN;
1.168 markus 649: c->local_window = c->local_window_max = window_max;
1.121 markus 650: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
651: packet_put_int(c->remote_id);
652: packet_put_int(c->local_window);
653: packet_send();
1.1 deraadt 654: }
655:
1.27 markus 656: /*
1.41 markus 657: * 'channel_pre*' are called just before select() to add any bits relevant to
658: * channels in the select bitmasks.
659: */
660: /*
661: * 'channel_post*': perform any appropriate operations for channels which
662: * have events pending.
1.27 markus 663: */
1.41 markus 664: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
665: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
666: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
667:
1.127 itojun 668: static void
1.41 markus 669: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
670: {
671: FD_SET(c->sock, readset);
672: }
673:
1.127 itojun 674: static void
1.75 markus 675: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
676: {
677: debug3("channel %d: waiting for connection", c->self);
678: FD_SET(c->sock, writeset);
679: }
680:
1.127 itojun 681: static void
1.41 markus 682: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
683: {
684: if (buffer_len(&c->input) < packet_get_maxsize())
685: FD_SET(c->sock, readset);
686: if (buffer_len(&c->output) > 0)
687: FD_SET(c->sock, writeset);
688: }
1.1 deraadt 689:
1.127 itojun 690: static void
1.157 markus 691: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 692: {
1.157 markus 693: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 694:
1.44 markus 695: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 696: limit > 0 &&
697: buffer_len(&c->input) < limit)
1.44 markus 698: FD_SET(c->rfd, readset);
699: if (c->ostate == CHAN_OUTPUT_OPEN ||
700: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
701: if (buffer_len(&c->output) > 0) {
702: FD_SET(c->wfd, writeset);
703: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 704: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.174 markus 705: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
706: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 707: else
708: chan_obuf_empty(c);
1.44 markus 709: }
710: }
711: /** XXX check close conditions, too */
1.157 markus 712: if (compat20 && c->efd != -1) {
1.44 markus 713: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
714: buffer_len(&c->extended) > 0)
715: FD_SET(c->efd, writeset);
1.172 markus 716: else if (!(c->flags & CHAN_EOF_SENT) &&
717: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 718: buffer_len(&c->extended) < c->remote_window)
719: FD_SET(c->efd, readset);
720: }
721: }
722:
1.127 itojun 723: static void
1.41 markus 724: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
725: {
726: if (buffer_len(&c->input) == 0) {
727: packet_start(SSH_MSG_CHANNEL_CLOSE);
728: packet_put_int(c->remote_id);
729: packet_send();
730: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 731: debug("channel %d: closing after input drain.", c->self);
1.41 markus 732: }
733: }
734:
1.127 itojun 735: static void
1.41 markus 736: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
737: {
738: if (buffer_len(&c->output) == 0)
1.113 markus 739: chan_mark_dead(c);
1.49 markus 740: else
1.41 markus 741: FD_SET(c->sock, writeset);
742: }
743:
744: /*
745: * This is a special state for X11 authentication spoofing. An opened X11
746: * connection (when authentication spoofing is being done) remains in this
747: * state until the first packet has been completely read. The authentication
748: * data in that packet is then substituted by the real data if it matches the
749: * fake data, and the channel is put into normal mode.
1.51 markus 750: * XXX All this happens at the client side.
1.121 markus 751: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 752: */
1.127 itojun 753: static int
1.121 markus 754: x11_open_helper(Buffer *b)
1.1 deraadt 755: {
1.77 markus 756: u_char *ucp;
757: u_int proto_len, data_len;
1.25 markus 758:
1.41 markus 759: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 760: if (buffer_len(b) < 12)
1.41 markus 761: return 0;
762:
763: /* Parse the lengths of variable-length fields. */
1.155 stevesk 764: ucp = buffer_ptr(b);
1.41 markus 765: if (ucp[0] == 0x42) { /* Byte order MSB first. */
766: proto_len = 256 * ucp[6] + ucp[7];
767: data_len = 256 * ucp[8] + ucp[9];
768: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
769: proto_len = ucp[6] + 256 * ucp[7];
770: data_len = ucp[8] + 256 * ucp[9];
771: } else {
772: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 773: ucp[0]);
1.41 markus 774: return -1;
775: }
776:
777: /* Check if the whole packet is in buffer. */
1.121 markus 778: if (buffer_len(b) <
1.41 markus 779: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
780: return 0;
781:
782: /* Check if authentication protocol matches. */
783: if (proto_len != strlen(x11_saved_proto) ||
784: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
785: debug("X11 connection uses different authentication protocol.");
786: return -1;
787: }
788: /* Check if authentication data matches our fake data. */
789: if (data_len != x11_fake_data_len ||
790: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
791: x11_fake_data, x11_fake_data_len) != 0) {
792: debug("X11 auth data does not match fake data.");
793: return -1;
794: }
795: /* Check fake data length */
796: if (x11_fake_data_len != x11_saved_data_len) {
797: error("X11 fake_data_len %d != saved_data_len %d",
798: x11_fake_data_len, x11_saved_data_len);
799: return -1;
800: }
801: /*
802: * Received authentication protocol and data match
803: * our fake data. Substitute the fake data with real
804: * data.
805: */
806: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
807: x11_saved_data, x11_saved_data_len);
808: return 1;
809: }
810:
1.127 itojun 811: static void
1.41 markus 812: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
813: {
1.121 markus 814: int ret = x11_open_helper(&c->output);
1.41 markus 815: if (ret == 1) {
816: /* Start normal processing for the channel. */
817: c->type = SSH_CHANNEL_OPEN;
1.47 markus 818: channel_pre_open_13(c, readset, writeset);
1.41 markus 819: } else if (ret == -1) {
820: /*
821: * We have received an X11 connection that has bad
822: * authentication information.
823: */
1.98 millert 824: log("X11 connection rejected because of wrong authentication.");
1.41 markus 825: buffer_clear(&c->input);
826: buffer_clear(&c->output);
1.132 markus 827: channel_close_fd(&c->sock);
1.41 markus 828: c->sock = -1;
829: c->type = SSH_CHANNEL_CLOSED;
830: packet_start(SSH_MSG_CHANNEL_CLOSE);
831: packet_put_int(c->remote_id);
832: packet_send();
833: }
834: }
1.25 markus 835:
1.127 itojun 836: static void
1.51 markus 837: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 838: {
1.121 markus 839: int ret = x11_open_helper(&c->output);
1.133 markus 840:
841: /* c->force_drain = 1; */
842:
1.41 markus 843: if (ret == 1) {
844: c->type = SSH_CHANNEL_OPEN;
1.157 markus 845: channel_pre_open(c, readset, writeset);
1.41 markus 846: } else if (ret == -1) {
1.156 markus 847: log("X11 connection rejected because of wrong authentication.");
1.41 markus 848: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 849: chan_read_failed(c);
850: buffer_clear(&c->input);
851: chan_ibuf_empty(c);
852: buffer_clear(&c->output);
853: /* for proto v1, the peer will send an IEOF */
854: if (compat20)
855: chan_write_failed(c);
856: else
857: c->type = SSH_CHANNEL_OPEN;
1.41 markus 858: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
859: }
860: }
1.25 markus 861:
1.104 markus 862: /* try to decode a socks4 header */
1.127 itojun 863: static int
1.104 markus 864: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 865: {
866: u_char *p, *host;
1.109 markus 867: int len, have, i, found;
1.148 deraadt 868: char username[256];
1.103 markus 869: struct {
870: u_int8_t version;
871: u_int8_t command;
872: u_int16_t dest_port;
1.104 markus 873: struct in_addr dest_addr;
1.103 markus 874: } s4_req, s4_rsp;
875:
1.104 markus 876: debug2("channel %d: decode socks4", c->self);
1.109 markus 877:
878: have = buffer_len(&c->input);
879: len = sizeof(s4_req);
880: if (have < len)
881: return 0;
882: p = buffer_ptr(&c->input);
883: for (found = 0, i = len; i < have; i++) {
884: if (p[i] == '\0') {
885: found = 1;
886: break;
887: }
888: if (i > 1024) {
889: /* the peer is probably sending garbage */
890: debug("channel %d: decode socks4: too long",
891: c->self);
892: return -1;
893: }
894: }
895: if (!found)
896: return 0;
1.103 markus 897: buffer_get(&c->input, (char *)&s4_req.version, 1);
898: buffer_get(&c->input, (char *)&s4_req.command, 1);
899: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 900: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 901: have = buffer_len(&c->input);
1.103 markus 902: p = buffer_ptr(&c->input);
903: len = strlen(p);
1.106 markus 904: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 905: if (len > have)
1.104 markus 906: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 907: c->self, len, have);
908: strlcpy(username, p, sizeof(username));
909: buffer_consume(&c->input, len);
910: buffer_consume(&c->input, 1); /* trailing '\0' */
911:
1.104 markus 912: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 913: strlcpy(c->path, host, sizeof(c->path));
914: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 915:
1.106 markus 916: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
917: c->self, host, c->host_port, s4_req.command);
1.103 markus 918:
1.104 markus 919: if (s4_req.command != 1) {
920: debug("channel %d: cannot handle: socks4 cn %d",
921: c->self, s4_req.command);
922: return -1;
1.103 markus 923: }
1.104 markus 924: s4_rsp.version = 0; /* vn: 0 for reply */
925: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 926: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 927: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 928: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 929: return 1;
930: }
931:
932: /* dynamic port forwarding */
1.127 itojun 933: static void
1.104 markus 934: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
935: {
936: u_char *p;
937: int have, ret;
1.103 markus 938:
1.104 markus 939: have = buffer_len(&c->input);
1.137 markus 940: c->delayed = 0;
1.104 markus 941: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 942: /* buffer_dump(&c->input); */
1.104 markus 943: /* check if the fixed size part of the packet is in buffer. */
944: if (have < 4) {
945: /* need more */
946: FD_SET(c->sock, readset);
947: return;
948: }
949: /* try to guess the protocol */
950: p = buffer_ptr(&c->input);
951: switch (p[0]) {
952: case 0x04:
953: ret = channel_decode_socks4(c, readset, writeset);
954: break;
955: default:
956: ret = -1;
957: break;
958: }
959: if (ret < 0) {
1.113 markus 960: chan_mark_dead(c);
1.104 markus 961: } else if (ret == 0) {
962: debug2("channel %d: pre_dynamic: need more", c->self);
963: /* need more */
964: FD_SET(c->sock, readset);
965: } else {
966: /* switch to the next state */
967: c->type = SSH_CHANNEL_OPENING;
968: port_open_helper(c, "direct-tcpip");
969: }
1.103 markus 970: }
971:
1.41 markus 972: /* This is our fake X11 server socket. */
1.127 itojun 973: static void
1.41 markus 974: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
975: {
1.113 markus 976: Channel *nc;
1.41 markus 977: struct sockaddr addr;
1.162 stevesk 978: int newsock;
1.41 markus 979: socklen_t addrlen;
1.85 markus 980: char buf[16384], *remote_ipaddr;
1.51 markus 981: int remote_port;
1.25 markus 982:
1.41 markus 983: if (FD_ISSET(c->sock, readset)) {
984: debug("X11 connection requested.");
985: addrlen = sizeof(addr);
986: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 987: if (c->single_connection) {
988: debug("single_connection: closing X11 listener.");
989: channel_close_fd(&c->sock);
990: chan_mark_dead(c);
991: }
1.41 markus 992: if (newsock < 0) {
993: error("accept: %.100s", strerror(errno));
994: return;
995: }
1.162 stevesk 996: set_nodelay(newsock);
1.85 markus 997: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 998: remote_port = get_peer_port(newsock);
1.41 markus 999: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1000: remote_ipaddr, remote_port);
1.51 markus 1001:
1.113 markus 1002: nc = channel_new("accepted x11 socket",
1.51 markus 1003: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1004: c->local_window_max, c->local_maxpacket,
1.71 markus 1005: 0, xstrdup(buf), 1);
1.51 markus 1006: if (compat20) {
1007: packet_start(SSH2_MSG_CHANNEL_OPEN);
1008: packet_put_cstring("x11");
1.113 markus 1009: packet_put_int(nc->self);
1.149 markus 1010: packet_put_int(nc->local_window_max);
1011: packet_put_int(nc->local_maxpacket);
1.85 markus 1012: /* originator ipaddr and port */
1013: packet_put_cstring(remote_ipaddr);
1.57 markus 1014: if (datafellows & SSH_BUG_X11FWD) {
1015: debug("ssh2 x11 bug compat mode");
1016: } else {
1017: packet_put_int(remote_port);
1018: }
1.51 markus 1019: packet_send();
1020: } else {
1021: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1022: packet_put_int(nc->self);
1.121 markus 1023: if (packet_get_protocol_flags() &
1024: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1025: packet_put_cstring(buf);
1.51 markus 1026: packet_send();
1027: }
1.85 markus 1028: xfree(remote_ipaddr);
1.41 markus 1029: }
1030: }
1.25 markus 1031:
1.127 itojun 1032: static void
1.103 markus 1033: port_open_helper(Channel *c, char *rtype)
1034: {
1035: int direct;
1036: char buf[1024];
1037: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1038: u_short remote_port = get_peer_port(c->sock);
1039:
1040: direct = (strcmp(rtype, "direct-tcpip") == 0);
1041:
1042: snprintf(buf, sizeof buf,
1043: "%s: listening port %d for %.100s port %d, "
1044: "connect from %.200s port %d",
1045: rtype, c->listening_port, c->path, c->host_port,
1046: remote_ipaddr, remote_port);
1047:
1048: xfree(c->remote_name);
1049: c->remote_name = xstrdup(buf);
1050:
1051: if (compat20) {
1052: packet_start(SSH2_MSG_CHANNEL_OPEN);
1053: packet_put_cstring(rtype);
1054: packet_put_int(c->self);
1055: packet_put_int(c->local_window_max);
1056: packet_put_int(c->local_maxpacket);
1057: if (direct) {
1058: /* target host, port */
1059: packet_put_cstring(c->path);
1060: packet_put_int(c->host_port);
1061: } else {
1062: /* listen address, port */
1063: packet_put_cstring(c->path);
1064: packet_put_int(c->listening_port);
1065: }
1066: /* originator host and port */
1067: packet_put_cstring(remote_ipaddr);
1068: packet_put_int(remote_port);
1069: packet_send();
1070: } else {
1071: packet_start(SSH_MSG_PORT_OPEN);
1072: packet_put_int(c->self);
1073: packet_put_cstring(c->path);
1074: packet_put_int(c->host_port);
1.121 markus 1075: if (packet_get_protocol_flags() &
1076: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1077: packet_put_cstring(c->remote_name);
1078: packet_send();
1079: }
1080: xfree(remote_ipaddr);
1081: }
1082:
1.41 markus 1083: /*
1084: * This socket is listening for connections to a forwarded TCP/IP port.
1085: */
1.127 itojun 1086: static void
1.41 markus 1087: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1088: {
1.103 markus 1089: Channel *nc;
1.41 markus 1090: struct sockaddr addr;
1.113 markus 1091: int newsock, nextstate;
1.41 markus 1092: socklen_t addrlen;
1.103 markus 1093: char *rtype;
1.73 markus 1094:
1.41 markus 1095: if (FD_ISSET(c->sock, readset)) {
1096: debug("Connection to port %d forwarding "
1097: "to %.100s port %d requested.",
1098: c->listening_port, c->path, c->host_port);
1.103 markus 1099:
1.137 markus 1100: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1101: nextstate = SSH_CHANNEL_OPENING;
1102: rtype = "forwarded-tcpip";
1103: } else {
1104: if (c->host_port == 0) {
1105: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1106: rtype = "dynamic-tcpip";
1.137 markus 1107: } else {
1108: nextstate = SSH_CHANNEL_OPENING;
1109: rtype = "direct-tcpip";
1110: }
1111: }
1.103 markus 1112:
1.41 markus 1113: addrlen = sizeof(addr);
1114: newsock = accept(c->sock, &addr, &addrlen);
1115: if (newsock < 0) {
1116: error("accept: %.100s", strerror(errno));
1117: return;
1118: }
1.169 stevesk 1119: set_nodelay(newsock);
1.113 markus 1120: nc = channel_new(rtype,
1.103 markus 1121: nextstate, newsock, newsock, -1,
1.41 markus 1122: c->local_window_max, c->local_maxpacket,
1.103 markus 1123: 0, xstrdup(rtype), 1);
1124: nc->listening_port = c->listening_port;
1125: nc->host_port = c->host_port;
1126: strlcpy(nc->path, c->path, sizeof(nc->path));
1127:
1.137 markus 1128: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1129: /*
1130: * do not call the channel_post handler until
1131: * this flag has been reset by a pre-handler.
1132: * otherwise the FD_ISSET calls might overflow
1133: */
1134: nc->delayed = 1;
1135: } else {
1.103 markus 1136: port_open_helper(nc, rtype);
1.137 markus 1137: }
1.41 markus 1138: }
1139: }
1.25 markus 1140:
1.41 markus 1141: /*
1142: * This is the authentication agent socket listening for connections from
1143: * clients.
1144: */
1.127 itojun 1145: static void
1.41 markus 1146: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1147: {
1.113 markus 1148: Channel *nc;
1.121 markus 1149: char *name;
1.113 markus 1150: int newsock;
1.41 markus 1151: struct sockaddr addr;
1152: socklen_t addrlen;
1.25 markus 1153:
1.41 markus 1154: if (FD_ISSET(c->sock, readset)) {
1155: addrlen = sizeof(addr);
1156: newsock = accept(c->sock, &addr, &addrlen);
1157: if (newsock < 0) {
1158: error("accept from auth socket: %.100s", strerror(errno));
1159: return;
1160: }
1.121 markus 1161: name = xstrdup("accepted auth socket");
1.113 markus 1162: nc = channel_new("accepted auth socket",
1.73 markus 1163: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1164: c->local_window_max, c->local_maxpacket,
1.121 markus 1165: 0, name, 1);
1.73 markus 1166: if (compat20) {
1167: packet_start(SSH2_MSG_CHANNEL_OPEN);
1168: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1169: packet_put_int(nc->self);
1.73 markus 1170: packet_put_int(c->local_window_max);
1171: packet_put_int(c->local_maxpacket);
1172: } else {
1173: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1174: packet_put_int(nc->self);
1.73 markus 1175: }
1.41 markus 1176: packet_send();
1177: }
1178: }
1.25 markus 1179:
1.127 itojun 1180: static void
1.75 markus 1181: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1182: {
1.114 markus 1183: int err = 0;
1.129 stevesk 1184: socklen_t sz = sizeof(err);
1.114 markus 1185:
1.75 markus 1186: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1187: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1188: err = errno;
1189: error("getsockopt SO_ERROR failed");
1190: }
1191: if (err == 0) {
1192: debug("channel %d: connected", c->self);
1193: c->type = SSH_CHANNEL_OPEN;
1194: if (compat20) {
1195: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1196: packet_put_int(c->remote_id);
1197: packet_put_int(c->self);
1198: packet_put_int(c->local_window);
1199: packet_put_int(c->local_maxpacket);
1200: } else {
1201: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1202: packet_put_int(c->remote_id);
1203: packet_put_int(c->self);
1204: }
1.75 markus 1205: } else {
1.114 markus 1206: debug("channel %d: not connected: %s",
1207: c->self, strerror(err));
1208: if (compat20) {
1209: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1210: packet_put_int(c->remote_id);
1211: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1212: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1213: packet_put_cstring(strerror(err));
1214: packet_put_cstring("");
1215: }
1.75 markus 1216: } else {
1.114 markus 1217: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1218: packet_put_int(c->remote_id);
1.75 markus 1219: }
1.114 markus 1220: chan_mark_dead(c);
1.75 markus 1221: }
1.114 markus 1222: packet_send();
1.75 markus 1223: }
1224: }
1225:
1.127 itojun 1226: static int
1.41 markus 1227: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1228: {
1229: char buf[16*1024];
1230: int len;
1.25 markus 1231:
1.118 markus 1232: if (c->rfd != -1 &&
1.41 markus 1233: FD_ISSET(c->rfd, readset)) {
1234: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1235: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1236: return 1;
1.41 markus 1237: if (len <= 0) {
1.51 markus 1238: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1239: c->self, c->rfd, len);
1.104 markus 1240: if (c->type != SSH_CHANNEL_OPEN) {
1241: debug("channel %d: not open", c->self);
1.113 markus 1242: chan_mark_dead(c);
1.103 markus 1243: return -1;
1.104 markus 1244: } else if (compat13) {
1.158 markus 1245: buffer_clear(&c->output);
1.41 markus 1246: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1247: debug("channel %d: input draining.", c->self);
1.25 markus 1248: } else {
1.41 markus 1249: chan_read_failed(c);
1.25 markus 1250: }
1.41 markus 1251: return -1;
1252: }
1.143 deraadt 1253: if (c->input_filter != NULL) {
1.66 markus 1254: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1255: debug("channel %d: filter stops", c->self);
1.65 markus 1256: chan_read_failed(c);
1257: }
1258: } else {
1259: buffer_append(&c->input, buf, len);
1260: }
1.41 markus 1261: }
1262: return 1;
1263: }
1.127 itojun 1264: static int
1.41 markus 1265: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1266: {
1.95 markus 1267: struct termios tio;
1.134 markus 1268: u_char *data;
1269: u_int dlen;
1.41 markus 1270: int len;
1.25 markus 1271:
1.41 markus 1272: /* Send buffered output data to the socket. */
1.118 markus 1273: if (c->wfd != -1 &&
1.41 markus 1274: FD_ISSET(c->wfd, writeset) &&
1275: buffer_len(&c->output) > 0) {
1.134 markus 1276: data = buffer_ptr(&c->output);
1277: dlen = buffer_len(&c->output);
1278: len = write(c->wfd, data, dlen);
1.53 markus 1279: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1280: return 1;
1.41 markus 1281: if (len <= 0) {
1.104 markus 1282: if (c->type != SSH_CHANNEL_OPEN) {
1283: debug("channel %d: not open", c->self);
1.113 markus 1284: chan_mark_dead(c);
1.104 markus 1285: return -1;
1286: } else if (compat13) {
1.158 markus 1287: buffer_clear(&c->output);
1.121 markus 1288: debug("channel %d: input draining.", c->self);
1.41 markus 1289: c->type = SSH_CHANNEL_INPUT_DRAINING;
1290: } else {
1291: chan_write_failed(c);
1292: }
1293: return -1;
1.91 markus 1294: }
1.134 markus 1295: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1296: if (tcgetattr(c->wfd, &tio) == 0 &&
1297: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1298: /*
1299: * Simulate echo to reduce the impact of
1.96 markus 1300: * traffic analysis. We need to match the
1.95 markus 1301: * size of a SSH2_MSG_CHANNEL_DATA message
1302: * (4 byte channel id + data)
1.91 markus 1303: */
1.95 markus 1304: packet_send_ignore(4 + len);
1.91 markus 1305: packet_send();
1306: }
1.25 markus 1307: }
1.41 markus 1308: buffer_consume(&c->output, len);
1.44 markus 1309: if (compat20 && len > 0) {
1310: c->local_consumed += len;
1311: }
1312: }
1313: return 1;
1314: }
1.127 itojun 1315: static int
1.44 markus 1316: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1317: {
1318: char buf[16*1024];
1319: int len;
1320:
1.45 markus 1321: /** XXX handle drain efd, too */
1.44 markus 1322: if (c->efd != -1) {
1323: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1324: FD_ISSET(c->efd, writeset) &&
1325: buffer_len(&c->extended) > 0) {
1326: len = write(c->efd, buffer_ptr(&c->extended),
1327: buffer_len(&c->extended));
1.70 markus 1328: debug2("channel %d: written %d to efd %d",
1.44 markus 1329: c->self, len, c->efd);
1.93 markus 1330: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1331: return 1;
1332: if (len <= 0) {
1333: debug2("channel %d: closing write-efd %d",
1334: c->self, c->efd);
1.132 markus 1335: channel_close_fd(&c->efd);
1.93 markus 1336: } else {
1.44 markus 1337: buffer_consume(&c->extended, len);
1338: c->local_consumed += len;
1339: }
1340: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1341: FD_ISSET(c->efd, readset)) {
1342: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1343: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1344: c->self, len, c->efd);
1.93 markus 1345: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1346: return 1;
1347: if (len <= 0) {
1348: debug2("channel %d: closing read-efd %d",
1.45 markus 1349: c->self, c->efd);
1.132 markus 1350: channel_close_fd(&c->efd);
1.93 markus 1351: } else {
1.44 markus 1352: buffer_append(&c->extended, buf, len);
1.93 markus 1353: }
1.44 markus 1354: }
1355: }
1356: return 1;
1357: }
1.127 itojun 1358: static int
1.93 markus 1359: channel_check_window(Channel *c)
1.44 markus 1360: {
1.104 markus 1361: if (c->type == SSH_CHANNEL_OPEN &&
1362: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1363: c->local_window < c->local_window_max/2 &&
1364: c->local_consumed > 0) {
1365: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1366: packet_put_int(c->remote_id);
1367: packet_put_int(c->local_consumed);
1368: packet_send();
1.70 markus 1369: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1370: c->self, c->local_window,
1371: c->local_consumed);
1372: c->local_window += c->local_consumed;
1373: c->local_consumed = 0;
1.1 deraadt 1374: }
1.41 markus 1375: return 1;
1.1 deraadt 1376: }
1377:
1.127 itojun 1378: static void
1.157 markus 1379: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1380: {
1.137 markus 1381: if (c->delayed)
1382: return;
1.41 markus 1383: channel_handle_rfd(c, readset, writeset);
1384: channel_handle_wfd(c, readset, writeset);
1.157 markus 1385: if (!compat20)
1.137 markus 1386: return;
1.44 markus 1387: channel_handle_efd(c, readset, writeset);
1.93 markus 1388: channel_check_window(c);
1.44 markus 1389: }
1390:
1.127 itojun 1391: static void
1.41 markus 1392: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1393: {
1.41 markus 1394: int len;
1395: /* Send buffered output data to the socket. */
1396: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1397: len = write(c->sock, buffer_ptr(&c->output),
1398: buffer_len(&c->output));
1399: if (len <= 0)
1.158 markus 1400: buffer_clear(&c->output);
1.41 markus 1401: else
1402: buffer_consume(&c->output, len);
1403: }
1404: }
1.25 markus 1405:
1.127 itojun 1406: static void
1.44 markus 1407: channel_handler_init_20(void)
1408: {
1.157 markus 1409: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1410: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1411: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1412: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1413: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1414: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1415: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1416: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1417:
1.157 markus 1418: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1419: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1420: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1421: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1422: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1423: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1424: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1425: }
1426:
1.127 itojun 1427: static void
1.41 markus 1428: channel_handler_init_13(void)
1429: {
1430: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1431: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1432: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1433: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1434: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1435: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1436: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1437: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1438: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1439:
1.157 markus 1440: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1441: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1442: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1443: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1444: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1445: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1446: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1447: }
1.25 markus 1448:
1.127 itojun 1449: static void
1.41 markus 1450: channel_handler_init_15(void)
1451: {
1.157 markus 1452: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1453: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1454: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1455: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1456: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1457: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1458: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1459:
1.41 markus 1460: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1461: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1462: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1463: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1464: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1465: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1466: }
1.27 markus 1467:
1.127 itojun 1468: static void
1.41 markus 1469: channel_handler_init(void)
1470: {
1471: int i;
1.148 deraadt 1472: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1473: channel_pre[i] = NULL;
1474: channel_post[i] = NULL;
1475: }
1.44 markus 1476: if (compat20)
1477: channel_handler_init_20();
1478: else if (compat13)
1.41 markus 1479: channel_handler_init_13();
1480: else
1481: channel_handler_init_15();
1482: }
1.25 markus 1483:
1.140 markus 1484: /* gc dead channels */
1485: static void
1486: channel_garbage_collect(Channel *c)
1487: {
1488: if (c == NULL)
1489: return;
1490: if (c->detach_user != NULL) {
1491: if (!chan_is_dead(c, 0))
1492: return;
1493: debug("channel %d: gc: notify user", c->self);
1494: c->detach_user(c->self, NULL);
1495: /* if we still have a callback */
1496: if (c->detach_user != NULL)
1497: return;
1498: debug("channel %d: gc: user detached", c->self);
1499: }
1500: if (!chan_is_dead(c, 1))
1501: return;
1502: debug("channel %d: garbage collecting", c->self);
1503: channel_free(c);
1504: }
1505:
1.127 itojun 1506: static void
1.41 markus 1507: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1508: {
1509: static int did_init = 0;
1510: int i;
1511: Channel *c;
1.25 markus 1512:
1.41 markus 1513: if (!did_init) {
1514: channel_handler_init();
1515: did_init = 1;
1516: }
1517: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1518: c = channels[i];
1519: if (c == NULL)
1.41 markus 1520: continue;
1.118 markus 1521: if (ftab[c->type] != NULL)
1522: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1523: channel_garbage_collect(c);
1.1 deraadt 1524: }
1525: }
1526:
1.121 markus 1527: /*
1528: * Allocate/update select bitmasks and add any bits relevant to channels in
1529: * select bitmasks.
1530: */
1.49 markus 1531: void
1.100 markus 1532: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1533: int *nallocp, int rekeying)
1.41 markus 1534: {
1.84 markus 1535: int n;
1536: u_int sz;
1537:
1538: n = MAX(*maxfdp, channel_max_fd);
1539:
1540: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1541: /* perhaps check sz < nalloc/2 and shrink? */
1542: if (*readsetp == NULL || sz > *nallocp) {
1543: *readsetp = xrealloc(*readsetp, sz);
1544: *writesetp = xrealloc(*writesetp, sz);
1545: *nallocp = sz;
1.84 markus 1546: }
1.132 markus 1547: *maxfdp = n;
1.84 markus 1548: memset(*readsetp, 0, sz);
1549: memset(*writesetp, 0, sz);
1550:
1.100 markus 1551: if (!rekeying)
1552: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1553: }
1554:
1.121 markus 1555: /*
1556: * After select, perform any appropriate operations for channels which have
1557: * events pending.
1558: */
1.49 markus 1559: void
1.41 markus 1560: channel_after_select(fd_set * readset, fd_set * writeset)
1561: {
1562: channel_handler(channel_post, readset, writeset);
1563: }
1564:
1.121 markus 1565:
1.84 markus 1566: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1567:
1.49 markus 1568: void
1.142 itojun 1569: channel_output_poll(void)
1.1 deraadt 1570: {
1.25 markus 1571: int len, i;
1.41 markus 1572: Channel *c;
1.1 deraadt 1573:
1.25 markus 1574: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1575: c = channels[i];
1576: if (c == NULL)
1577: continue;
1.37 markus 1578:
1.121 markus 1579: /*
1580: * We are only interested in channels that can have buffered
1581: * incoming data.
1582: */
1.37 markus 1583: if (compat13) {
1.41 markus 1584: if (c->type != SSH_CHANNEL_OPEN &&
1585: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1586: continue;
1587: } else {
1.41 markus 1588: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1589: continue;
1590: }
1.46 markus 1591: if (compat20 &&
1592: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1593: /* XXX is this true? */
1.140 markus 1594: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1595: continue;
1596: }
1.25 markus 1597:
1598: /* Get the amount of buffered data for this channel. */
1.93 markus 1599: if ((c->istate == CHAN_INPUT_OPEN ||
1600: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1601: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1602: /*
1603: * Send some data for the other side over the secure
1604: * connection.
1605: */
1.44 markus 1606: if (compat20) {
1607: if (len > c->remote_window)
1608: len = c->remote_window;
1609: if (len > c->remote_maxpacket)
1610: len = c->remote_maxpacket;
1.25 markus 1611: } else {
1.44 markus 1612: if (packet_is_interactive()) {
1613: if (len > 1024)
1614: len = 512;
1615: } else {
1616: /* Keep the packets at reasonable size. */
1617: if (len > packet_get_maxsize()/2)
1618: len = packet_get_maxsize()/2;
1619: }
1.25 markus 1620: }
1.41 markus 1621: if (len > 0) {
1.44 markus 1622: packet_start(compat20 ?
1623: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1624: packet_put_int(c->remote_id);
1625: packet_put_string(buffer_ptr(&c->input), len);
1626: packet_send();
1627: buffer_consume(&c->input, len);
1628: c->remote_window -= len;
1629: }
1630: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1631: if (compat13)
1632: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1633: /*
1634: * input-buffer is empty and read-socket shutdown:
1.172 markus 1635: * tell peer, that we will not send more data: send IEOF.
1636: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1637: */
1.172 markus 1638: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.174 markus 1639: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1640: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1641: else
1642: chan_ibuf_empty(c);
1.25 markus 1643: }
1.44 markus 1644: /* Send extended data, i.e. stderr */
1645: if (compat20 &&
1.172 markus 1646: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1647: c->remote_window > 0 &&
1648: (len = buffer_len(&c->extended)) > 0 &&
1649: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1650: debug2("channel %d: rwin %d elen %d euse %d",
1651: c->self, c->remote_window, buffer_len(&c->extended),
1652: c->extended_usage);
1.44 markus 1653: if (len > c->remote_window)
1654: len = c->remote_window;
1655: if (len > c->remote_maxpacket)
1656: len = c->remote_maxpacket;
1657: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1658: packet_put_int(c->remote_id);
1659: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1660: packet_put_string(buffer_ptr(&c->extended), len);
1661: packet_send();
1662: buffer_consume(&c->extended, len);
1663: c->remote_window -= len;
1.93 markus 1664: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1665: }
1.25 markus 1666: }
1.1 deraadt 1667: }
1668:
1.121 markus 1669:
1670: /* -- protocol input */
1.1 deraadt 1671:
1.49 markus 1672: void
1.154 markus 1673: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1674: {
1.37 markus 1675: int id;
1.25 markus 1676: char *data;
1.77 markus 1677: u_int data_len;
1.41 markus 1678: Channel *c;
1.25 markus 1679:
1680: /* Get the channel number and verify it. */
1.37 markus 1681: id = packet_get_int();
1.41 markus 1682: c = channel_lookup(id);
1683: if (c == NULL)
1.37 markus 1684: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1685:
1686: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1687: if (c->type != SSH_CHANNEL_OPEN &&
1688: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1689: return;
1690:
1691: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1692: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1693: return;
1694:
1695: /* Get the data. */
1696: data = packet_get_string(&data_len);
1.41 markus 1697:
1.143 deraadt 1698: if (compat20) {
1.44 markus 1699: if (data_len > c->local_maxpacket) {
1700: log("channel %d: rcvd big packet %d, maxpack %d",
1701: c->self, data_len, c->local_maxpacket);
1702: }
1703: if (data_len > c->local_window) {
1704: log("channel %d: rcvd too much data %d, win %d",
1705: c->self, data_len, c->local_window);
1706: xfree(data);
1707: return;
1708: }
1709: c->local_window -= data_len;
1710: }
1.152 markus 1711: packet_check_eom();
1.41 markus 1712: buffer_append(&c->output, data, data_len);
1.25 markus 1713: xfree(data);
1.1 deraadt 1714: }
1.121 markus 1715:
1.49 markus 1716: void
1.154 markus 1717: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1718: {
1719: int id;
1720: int tcode;
1721: char *data;
1.77 markus 1722: u_int data_len;
1.44 markus 1723: Channel *c;
1724:
1725: /* Get the channel number and verify it. */
1726: id = packet_get_int();
1727: c = channel_lookup(id);
1728:
1729: if (c == NULL)
1730: packet_disconnect("Received extended_data for bad channel %d.", id);
1731: if (c->type != SSH_CHANNEL_OPEN) {
1732: log("channel %d: ext data for non open", id);
1733: return;
1.172 markus 1734: }
1735: if (c->flags & CHAN_EOF_RCVD) {
1736: if (datafellows & SSH_BUG_EXTEOF)
1737: debug("channel %d: accepting ext data after eof", id);
1738: else
1739: packet_disconnect("Received extended_data after EOF "
1740: "on channel %d.", id);
1.44 markus 1741: }
1742: tcode = packet_get_int();
1743: if (c->efd == -1 ||
1744: c->extended_usage != CHAN_EXTENDED_WRITE ||
1745: tcode != SSH2_EXTENDED_DATA_STDERR) {
1746: log("channel %d: bad ext data", c->self);
1747: return;
1748: }
1749: data = packet_get_string(&data_len);
1.152 markus 1750: packet_check_eom();
1.44 markus 1751: if (data_len > c->local_window) {
1752: log("channel %d: rcvd too much extended_data %d, win %d",
1753: c->self, data_len, c->local_window);
1754: xfree(data);
1755: return;
1756: }
1.70 markus 1757: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1758: c->local_window -= data_len;
1759: buffer_append(&c->extended, data, data_len);
1760: xfree(data);
1761: }
1762:
1.49 markus 1763: void
1.154 markus 1764: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1765: {
1766: int id;
1767: Channel *c;
1768:
1769: id = packet_get_int();
1.152 markus 1770: packet_check_eom();
1.41 markus 1771: c = channel_lookup(id);
1772: if (c == NULL)
1773: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1774: chan_rcvd_ieof(c);
1.133 markus 1775:
1776: /* XXX force input close */
1.156 markus 1777: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1778: debug("channel %d: FORCE input drain", c->self);
1779: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1780: if (buffer_len(&c->input) == 0)
1781: chan_ibuf_empty(c);
1.133 markus 1782: }
1783:
1.41 markus 1784: }
1.1 deraadt 1785:
1.49 markus 1786: void
1.154 markus 1787: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1788: {
1.41 markus 1789: int id;
1790: Channel *c;
1.1 deraadt 1791:
1.41 markus 1792: id = packet_get_int();
1.152 markus 1793: packet_check_eom();
1.41 markus 1794: c = channel_lookup(id);
1795: if (c == NULL)
1796: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1797:
1798: /*
1799: * Send a confirmation that we have closed the channel and no more
1800: * data is coming for it.
1801: */
1.25 markus 1802: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1803: packet_put_int(c->remote_id);
1.25 markus 1804: packet_send();
1805:
1.27 markus 1806: /*
1807: * If the channel is in closed state, we have sent a close request,
1808: * and the other side will eventually respond with a confirmation.
1809: * Thus, we cannot free the channel here, because then there would be
1810: * no-one to receive the confirmation. The channel gets freed when
1811: * the confirmation arrives.
1812: */
1.41 markus 1813: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1814: /*
1815: * Not a closed channel - mark it as draining, which will
1816: * cause it to be freed later.
1817: */
1.158 markus 1818: buffer_clear(&c->input);
1.41 markus 1819: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1820: }
1.1 deraadt 1821: }
1822:
1.41 markus 1823: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1824: void
1.154 markus 1825: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1826: {
1827: int id = packet_get_int();
1828: Channel *c = channel_lookup(id);
1.151 markus 1829:
1.152 markus 1830: packet_check_eom();
1.41 markus 1831: if (c == NULL)
1832: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1833: chan_rcvd_oclose(c);
1834: }
1.1 deraadt 1835:
1.49 markus 1836: void
1.154 markus 1837: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1838: {
1.41 markus 1839: int id = packet_get_int();
1840: Channel *c = channel_lookup(id);
1.1 deraadt 1841:
1.152 markus 1842: packet_check_eom();
1.41 markus 1843: if (c == NULL)
1844: packet_disconnect("Received close confirmation for "
1845: "out-of-range channel %d.", id);
1846: if (c->type != SSH_CHANNEL_CLOSED)
1847: packet_disconnect("Received close confirmation for "
1848: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1849: channel_free(c);
1.1 deraadt 1850: }
1851:
1.49 markus 1852: void
1.154 markus 1853: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1854: {
1.41 markus 1855: int id, remote_id;
1856: Channel *c;
1.1 deraadt 1857:
1.41 markus 1858: id = packet_get_int();
1859: c = channel_lookup(id);
1.25 markus 1860:
1.41 markus 1861: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1862: packet_disconnect("Received open confirmation for "
1863: "non-opening channel %d.", id);
1864: remote_id = packet_get_int();
1.27 markus 1865: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1866: c->remote_id = remote_id;
1867: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1868:
1869: if (compat20) {
1870: c->remote_window = packet_get_int();
1871: c->remote_maxpacket = packet_get_int();
1.165 markus 1872: if (c->confirm) {
1.70 markus 1873: debug2("callback start");
1.165 markus 1874: c->confirm(c->self, NULL);
1.70 markus 1875: debug2("callback done");
1.44 markus 1876: }
1877: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1878: c->remote_window, c->remote_maxpacket);
1879: }
1.152 markus 1880: packet_check_eom();
1.1 deraadt 1881: }
1882:
1.127 itojun 1883: static char *
1.114 markus 1884: reason2txt(int reason)
1885: {
1.143 deraadt 1886: switch (reason) {
1.114 markus 1887: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1888: return "administratively prohibited";
1889: case SSH2_OPEN_CONNECT_FAILED:
1890: return "connect failed";
1891: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1892: return "unknown channel type";
1893: case SSH2_OPEN_RESOURCE_SHORTAGE:
1894: return "resource shortage";
1895: }
1.117 stevesk 1896: return "unknown reason";
1.114 markus 1897: }
1898:
1.49 markus 1899: void
1.154 markus 1900: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1901: {
1.86 markus 1902: int id, reason;
1903: char *msg = NULL, *lang = NULL;
1.41 markus 1904: Channel *c;
1905:
1906: id = packet_get_int();
1907: c = channel_lookup(id);
1.25 markus 1908:
1.41 markus 1909: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1910: packet_disconnect("Received open failure for "
1911: "non-opening channel %d.", id);
1.44 markus 1912: if (compat20) {
1.86 markus 1913: reason = packet_get_int();
1.110 markus 1914: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1915: msg = packet_get_string(NULL);
1916: lang = packet_get_string(NULL);
1917: }
1.114 markus 1918: log("channel %d: open failed: %s%s%s", id,
1919: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1920: if (msg != NULL)
1921: xfree(msg);
1922: if (lang != NULL)
1923: xfree(lang);
1.44 markus 1924: }
1.152 markus 1925: packet_check_eom();
1.25 markus 1926: /* Free the channel. This will also close the socket. */
1.113 markus 1927: channel_free(c);
1.44 markus 1928: }
1929:
1.121 markus 1930: void
1.154 markus 1931: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1932: {
1933: Channel *c;
1934: int id, adjust;
1935:
1936: if (!compat20)
1937: return;
1938:
1939: /* Get the channel number and verify it. */
1940: id = packet_get_int();
1941: c = channel_lookup(id);
1.1 deraadt 1942:
1.121 markus 1943: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1944: log("Received window adjust for "
1945: "non-open channel %d.", id);
1946: return;
1947: }
1948: adjust = packet_get_int();
1.152 markus 1949: packet_check_eom();
1.121 markus 1950: debug2("channel %d: rcvd adjust %d", id, adjust);
1951: c->remote_window += adjust;
1952: }
1.1 deraadt 1953:
1.121 markus 1954: void
1.154 markus 1955: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1956: {
1.121 markus 1957: Channel *c = NULL;
1958: u_short host_port;
1959: char *host, *originator_string;
1960: int remote_id, sock = -1;
1961:
1962: remote_id = packet_get_int();
1963: host = packet_get_string(NULL);
1964: host_port = packet_get_int();
1.25 markus 1965:
1.121 markus 1966: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1967: originator_string = packet_get_string(NULL);
1968: } else {
1969: originator_string = xstrdup("unknown (remote did not supply name)");
1970: }
1.152 markus 1971: packet_check_eom();
1.121 markus 1972: sock = channel_connect_to(host, host_port);
1973: if (sock != -1) {
1974: c = channel_new("connected socket",
1975: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1976: originator_string, 1);
1.167 markus 1977: c->remote_id = remote_id;
1.25 markus 1978: }
1.121 markus 1979: if (c == NULL) {
1980: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1981: packet_put_int(remote_id);
1982: packet_send();
1983: }
1984: xfree(host);
1.1 deraadt 1985: }
1986:
1.121 markus 1987:
1988: /* -- tcp forwarding */
1.135 markus 1989:
1990: void
1991: channel_set_af(int af)
1992: {
1993: IPv4or6 = af;
1994: }
1.121 markus 1995:
1.160 markus 1996: static int
1997: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
1998: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 1999: {
1.113 markus 2000: Channel *c;
1.160 markus 2001: int success, sock, on = 1;
1.35 markus 2002: struct addrinfo hints, *ai, *aitop;
1.160 markus 2003: const char *host;
1.35 markus 2004: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2005: struct linger linger;
1.25 markus 2006:
1.87 markus 2007: success = 0;
1.160 markus 2008: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2009: listen_addr : host_to_connect;
1.87 markus 2010:
1.160 markus 2011: if (host == NULL) {
2012: error("No forward host name.");
2013: return success;
1.73 markus 2014: }
1.113 markus 2015: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2016: error("Forward host name too long.");
2017: return success;
2018: }
1.25 markus 2019:
1.28 markus 2020: /*
1.35 markus 2021: * getaddrinfo returns a loopback address if the hostname is
2022: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2023: */
1.35 markus 2024: memset(&hints, 0, sizeof(hints));
2025: hints.ai_family = IPv4or6;
2026: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2027: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2028: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2029: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2030: packet_disconnect("getaddrinfo: fatal error");
2031:
2032: for (ai = aitop; ai; ai = ai->ai_next) {
2033: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2034: continue;
2035: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2036: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2037: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2038: continue;
2039: }
2040: /* Create a port to listen for the host. */
2041: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2042: if (sock < 0) {
2043: /* this is no error since kernel may not support ipv6 */
2044: verbose("socket: %.100s", strerror(errno));
2045: continue;
2046: }
2047: /*
2048: * Set socket options. We would like the socket to disappear
2049: * as soon as it has been closed for whatever reason.
2050: */
1.170 stevesk 2051: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
1.35 markus 2052: linger.l_onoff = 1;
2053: linger.l_linger = 5;
1.170 stevesk 2054: setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
1.35 markus 2055: debug("Local forwarding listening on %s port %s.", ntop, strport);
2056:
2057: /* Bind the socket to the address. */
2058: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2059: /* address can be in use ipv6 address is already bound */
2060: verbose("bind: %.100s", strerror(errno));
2061: close(sock);
2062: continue;
2063: }
2064: /* Start listening for connections on the socket. */
2065: if (listen(sock, 5) < 0) {
2066: error("listen: %.100s", strerror(errno));
2067: close(sock);
2068: continue;
2069: }
2070: /* Allocate a channel number for the socket. */
1.121 markus 2071: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2072: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2073: 0, xstrdup("port listener"), 1);
1.113 markus 2074: strlcpy(c->path, host, sizeof(c->path));
2075: c->host_port = port_to_connect;
2076: c->listening_port = listen_port;
1.35 markus 2077: success = 1;
2078: }
2079: if (success == 0)
1.160 markus 2080: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2081: listen_port);
1.35 markus 2082: freeaddrinfo(aitop);
1.87 markus 2083: return success;
1.25 markus 2084: }
1.1 deraadt 2085:
1.160 markus 2086: /* protocol local port fwd, used by ssh (and sshd in v1) */
2087: int
2088: channel_setup_local_fwd_listener(u_short listen_port,
2089: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2090: {
2091: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2092: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2093: }
2094:
2095: /* protocol v2 remote port fwd, used by sshd */
2096: int
2097: channel_setup_remote_fwd_listener(const char *listen_address,
2098: u_short listen_port, int gateway_ports)
2099: {
2100: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2101: listen_address, listen_port, NULL, 0, gateway_ports);
2102: }
2103:
1.27 markus 2104: /*
2105: * Initiate forwarding of connections to port "port" on remote host through
2106: * the secure channel to host:port from local side.
2107: */
1.1 deraadt 2108:
1.49 markus 2109: void
1.73 markus 2110: channel_request_remote_forwarding(u_short listen_port,
2111: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2112: {
1.153 markus 2113: int type, success = 0;
1.73 markus 2114:
1.25 markus 2115: /* Record locally that connection to this host/port is permitted. */
2116: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2117: fatal("channel_request_remote_forwarding: too many forwards");
2118:
2119: /* Send the forward request to the remote side. */
1.44 markus 2120: if (compat20) {
2121: const char *address_to_bind = "0.0.0.0";
2122: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2123: packet_put_cstring("tcpip-forward");
1.173 markus 2124: packet_put_char(1); /* boolean: want reply */
1.44 markus 2125: packet_put_cstring(address_to_bind);
2126: packet_put_int(listen_port);
1.73 markus 2127: packet_send();
2128: packet_write_wait();
2129: /* Assume that server accepts the request */
2130: success = 1;
1.44 markus 2131: } else {
2132: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2133: packet_put_int(listen_port);
2134: packet_put_cstring(host_to_connect);
1.44 markus 2135: packet_put_int(port_to_connect);
2136: packet_send();
2137: packet_write_wait();
1.73 markus 2138:
2139: /* Wait for response from the remote side. */
1.153 markus 2140: type = packet_read();
1.73 markus 2141: switch (type) {
2142: case SSH_SMSG_SUCCESS:
2143: success = 1;
2144: break;
2145: case SSH_SMSG_FAILURE:
2146: log("Warning: Server denied remote port forwarding.");
2147: break;
2148: default:
2149: /* Unknown packet */
2150: packet_disconnect("Protocol error for port forward request:"
2151: "received packet type %d.", type);
2152: }
2153: }
2154: if (success) {
2155: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2156: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2157: permitted_opens[num_permitted_opens].listen_port = listen_port;
2158: num_permitted_opens++;
1.44 markus 2159: }
1.1 deraadt 2160: }
2161:
1.27 markus 2162: /*
2163: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2164: * listening for the port, and sends back a success reply (or disconnect
2165: * message if there was an error). This never returns if there was an error.
2166: */
1.1 deraadt 2167:
1.49 markus 2168: void
1.56 markus 2169: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2170: {
1.31 markus 2171: u_short port, host_port;
1.25 markus 2172: char *hostname;
1.1 deraadt 2173:
1.25 markus 2174: /* Get arguments from the packet. */
2175: port = packet_get_int();
2176: hostname = packet_get_string(NULL);
2177: host_port = packet_get_int();
2178:
1.27 markus 2179: /*
2180: * Check that an unprivileged user is not trying to forward a
2181: * privileged port.
2182: */
1.25 markus 2183: if (port < IPPORT_RESERVED && !is_root)
2184: packet_disconnect("Requested forwarding of port %d but user is not root.",
2185: port);
1.73 markus 2186: /* Initiate forwarding */
1.160 markus 2187: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2188:
2189: /* Free the argument string. */
2190: xfree(hostname);
1.1 deraadt 2191: }
2192:
1.99 markus 2193: /*
2194: * Permits opening to any host/port if permitted_opens[] is empty. This is
2195: * usually called by the server, because the user could connect to any port
2196: * anyway, and the server has no way to know but to trust the client anyway.
2197: */
2198: void
1.142 itojun 2199: channel_permit_all_opens(void)
1.99 markus 2200: {
2201: if (num_permitted_opens == 0)
2202: all_opens_permitted = 1;
2203: }
2204:
1.101 markus 2205: void
1.99 markus 2206: channel_add_permitted_opens(char *host, int port)
2207: {
2208: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2209: fatal("channel_request_remote_forwarding: too many forwards");
2210: debug("allow port forwarding to host %s port %d", host, port);
2211:
2212: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2213: permitted_opens[num_permitted_opens].port_to_connect = port;
2214: num_permitted_opens++;
2215:
2216: all_opens_permitted = 0;
2217: }
2218:
1.101 markus 2219: void
1.99 markus 2220: channel_clear_permitted_opens(void)
2221: {
2222: int i;
2223:
2224: for (i = 0; i < num_permitted_opens; i++)
2225: xfree(permitted_opens[i].host_to_connect);
2226: num_permitted_opens = 0;
2227:
2228: }
2229:
2230:
2231: /* return socket to remote host, port */
1.127 itojun 2232: static int
1.99 markus 2233: connect_to(const char *host, u_short port)
1.41 markus 2234: {
2235: struct addrinfo hints, *ai, *aitop;
2236: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2237: int gaierr;
2238: int sock = -1;
2239:
2240: memset(&hints, 0, sizeof(hints));
2241: hints.ai_family = IPv4or6;
2242: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2243: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2244: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2245: error("connect_to %.100s: unknown host (%s)", host,
2246: gai_strerror(gaierr));
1.41 markus 2247: return -1;
2248: }
2249: for (ai = aitop; ai; ai = ai->ai_next) {
2250: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2251: continue;
2252: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2253: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2254: error("connect_to: getnameinfo failed");
1.41 markus 2255: continue;
2256: }
2257: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2258: if (sock < 0) {
2259: error("socket: %.100s", strerror(errno));
2260: continue;
2261: }
1.80 markus 2262: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2263: fatal("connect_to: F_SETFL: %s", strerror(errno));
2264: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2265: errno != EINPROGRESS) {
1.99 markus 2266: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2267: strerror(errno));
2268: close(sock);
1.89 stevesk 2269: continue; /* fail -- try next */
1.41 markus 2270: }
2271: break; /* success */
2272:
2273: }
2274: freeaddrinfo(aitop);
2275: if (!ai) {
1.99 markus 2276: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2277: return -1;
2278: }
2279: /* success */
1.169 stevesk 2280: set_nodelay(sock);
1.41 markus 2281: return sock;
2282: }
1.99 markus 2283:
1.73 markus 2284: int
1.130 stevesk 2285: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2286: {
2287: int i;
1.99 markus 2288:
1.73 markus 2289: for (i = 0; i < num_permitted_opens; i++)
2290: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2291: return connect_to(
1.73 markus 2292: permitted_opens[i].host_to_connect,
2293: permitted_opens[i].port_to_connect);
1.74 markus 2294: error("WARNING: Server requests forwarding for unknown listen_port %d",
2295: listen_port);
1.73 markus 2296: return -1;
2297: }
2298:
1.99 markus 2299: /* Check if connecting to that port is permitted and connect. */
2300: int
2301: channel_connect_to(const char *host, u_short port)
2302: {
2303: int i, permit;
2304:
2305: permit = all_opens_permitted;
2306: if (!permit) {
2307: for (i = 0; i < num_permitted_opens; i++)
2308: if (permitted_opens[i].port_to_connect == port &&
2309: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2310: permit = 1;
2311:
2312: }
2313: if (!permit) {
2314: log("Received request to connect to host %.100s port %d, "
2315: "but the request was denied.", host, port);
2316: return -1;
2317: }
2318: return connect_to(host, port);
2319: }
2320:
1.121 markus 2321: /* -- X11 forwarding */
1.1 deraadt 2322:
1.27 markus 2323: /*
2324: * Creates an internet domain socket for listening for X11 connections.
1.176 ! deraadt 2325: * Returns 0 and a suitable display number for the DISPLAY variable
! 2326: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2327: */
1.141 stevesk 2328: int
1.163 stevesk 2329: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.176 ! deraadt 2330: int single_connection, u_int *display_numberp)
1.1 deraadt 2331: {
1.149 markus 2332: Channel *nc = NULL;
1.31 markus 2333: int display_number, sock;
2334: u_short port;
1.35 markus 2335: struct addrinfo hints, *ai, *aitop;
2336: char strport[NI_MAXSERV];
2337: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2338:
1.33 markus 2339: for (display_number = x11_display_offset;
1.148 deraadt 2340: display_number < MAX_DISPLAYS;
2341: display_number++) {
1.25 markus 2342: port = 6000 + display_number;
1.35 markus 2343: memset(&hints, 0, sizeof(hints));
2344: hints.ai_family = IPv4or6;
1.163 stevesk 2345: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2346: hints.ai_socktype = SOCK_STREAM;
2347: snprintf(strport, sizeof strport, "%d", port);
2348: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2349: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2350: return -1;
1.25 markus 2351: }
1.35 markus 2352: for (ai = aitop; ai; ai = ai->ai_next) {
2353: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2354: continue;
2355: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2356: if (sock < 0) {
2357: error("socket: %.100s", strerror(errno));
1.141 stevesk 2358: return -1;
1.35 markus 2359: }
2360: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2361: debug("bind port %d: %.100s", port, strerror(errno));
2362: close(sock);
2363: for (n = 0; n < num_socks; n++) {
2364: close(socks[n]);
2365: }
2366: num_socks = 0;
2367: break;
2368: }
2369: socks[num_socks++] = sock;
2370: if (num_socks == NUM_SOCKS)
2371: break;
1.25 markus 2372: }
1.83 stevesk 2373: freeaddrinfo(aitop);
1.35 markus 2374: if (num_socks > 0)
2375: break;
1.25 markus 2376: }
2377: if (display_number >= MAX_DISPLAYS) {
2378: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2379: return -1;
1.25 markus 2380: }
2381: /* Start listening for connections on the socket. */
1.35 markus 2382: for (n = 0; n < num_socks; n++) {
2383: sock = socks[n];
2384: if (listen(sock, 5) < 0) {
2385: error("listen: %.100s", strerror(errno));
2386: close(sock);
1.141 stevesk 2387: return -1;
1.35 markus 2388: }
1.25 markus 2389: }
1.35 markus 2390:
2391: /* Allocate a channel for each socket. */
2392: for (n = 0; n < num_socks; n++) {
2393: sock = socks[n];
1.149 markus 2394: nc = channel_new("x11 listener",
1.51 markus 2395: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2396: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2397: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2398: nc->single_connection = single_connection;
1.35 markus 2399: }
1.1 deraadt 2400:
1.141 stevesk 2401: /* Return the display number for the DISPLAY environment variable. */
1.176 ! deraadt 2402: *display_numberp = display_number;
! 2403: return (0);
1.1 deraadt 2404: }
2405:
1.127 itojun 2406: static int
1.77 markus 2407: connect_local_xsocket(u_int dnr)
1.1 deraadt 2408: {
1.25 markus 2409: int sock;
2410: struct sockaddr_un addr;
2411:
1.147 stevesk 2412: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2413: if (sock < 0)
2414: error("socket: %.100s", strerror(errno));
2415: memset(&addr, 0, sizeof(addr));
2416: addr.sun_family = AF_UNIX;
2417: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2418: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2419: return sock;
2420: close(sock);
1.25 markus 2421: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2422: return -1;
1.1 deraadt 2423: }
2424:
1.51 markus 2425: int
2426: x11_connect_display(void)
1.1 deraadt 2427: {
1.162 stevesk 2428: int display_number, sock = 0;
1.25 markus 2429: const char *display;
1.51 markus 2430: char buf[1024], *cp;
1.35 markus 2431: struct addrinfo hints, *ai, *aitop;
2432: char strport[NI_MAXSERV];
2433: int gaierr;
1.25 markus 2434:
2435: /* Try to open a socket for the local X server. */
2436: display = getenv("DISPLAY");
2437: if (!display) {
2438: error("DISPLAY not set.");
1.51 markus 2439: return -1;
1.25 markus 2440: }
1.27 markus 2441: /*
2442: * Now we decode the value of the DISPLAY variable and make a
2443: * connection to the real X server.
2444: */
2445:
2446: /*
2447: * Check if it is a unix domain socket. Unix domain displays are in
2448: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2449: */
1.25 markus 2450: if (strncmp(display, "unix:", 5) == 0 ||
2451: display[0] == ':') {
2452: /* Connect to the unix domain socket. */
2453: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2454: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2455: display);
1.51 markus 2456: return -1;
1.25 markus 2457: }
2458: /* Create a socket. */
2459: sock = connect_local_xsocket(display_number);
2460: if (sock < 0)
1.51 markus 2461: return -1;
1.25 markus 2462:
2463: /* OK, we now have a connection to the display. */
1.51 markus 2464: return sock;
1.25 markus 2465: }
1.27 markus 2466: /*
2467: * Connect to an inet socket. The DISPLAY value is supposedly
2468: * hostname:d[.s], where hostname may also be numeric IP address.
2469: */
1.145 stevesk 2470: strlcpy(buf, display, sizeof(buf));
1.25 markus 2471: cp = strchr(buf, ':');
2472: if (!cp) {
2473: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2474: return -1;
1.25 markus 2475: }
2476: *cp = 0;
1.27 markus 2477: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2478: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2479: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2480: display);
1.51 markus 2481: return -1;
1.25 markus 2482: }
1.35 markus 2483:
2484: /* Look up the host address */
2485: memset(&hints, 0, sizeof(hints));
2486: hints.ai_family = IPv4or6;
2487: hints.ai_socktype = SOCK_STREAM;
2488: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2489: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2490: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2491: return -1;
1.25 markus 2492: }
1.35 markus 2493: for (ai = aitop; ai; ai = ai->ai_next) {
2494: /* Create a socket. */
2495: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2496: if (sock < 0) {
2497: debug("socket: %.100s", strerror(errno));
1.41 markus 2498: continue;
2499: }
2500: /* Connect it to the display. */
2501: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2502: debug("connect %.100s port %d: %.100s", buf,
2503: 6000 + display_number, strerror(errno));
2504: close(sock);
2505: continue;
2506: }
2507: /* Success */
2508: break;
1.35 markus 2509: }
2510: freeaddrinfo(aitop);
2511: if (!ai) {
1.49 markus 2512: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2513: strerror(errno));
1.51 markus 2514: return -1;
1.25 markus 2515: }
1.162 stevesk 2516: set_nodelay(sock);
1.51 markus 2517: return sock;
2518: }
2519:
2520: /*
2521: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2522: * the remote channel number. We should do whatever we want, and respond
2523: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2524: */
2525:
2526: void
1.154 markus 2527: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2528: {
1.113 markus 2529: Channel *c = NULL;
2530: int remote_id, sock = 0;
1.51 markus 2531: char *remote_host;
1.25 markus 2532:
1.113 markus 2533: debug("Received X11 open request.");
1.51 markus 2534:
1.113 markus 2535: remote_id = packet_get_int();
1.121 markus 2536:
2537: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2538: remote_host = packet_get_string(NULL);
1.51 markus 2539: } else {
2540: remote_host = xstrdup("unknown (remote did not supply name)");
2541: }
1.152 markus 2542: packet_check_eom();
1.25 markus 2543:
1.51 markus 2544: /* Obtain a connection to the real X display. */
2545: sock = x11_connect_display();
1.113 markus 2546: if (sock != -1) {
2547: /* Allocate a channel for this connection. */
2548: c = channel_new("connected x11 socket",
2549: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2550: remote_host, 1);
1.167 markus 2551: c->remote_id = remote_id;
2552: c->force_drain = 1;
1.113 markus 2553: }
2554: if (c == NULL) {
1.51 markus 2555: /* Send refusal to the remote host. */
2556: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2557: packet_put_int(remote_id);
1.51 markus 2558: } else {
2559: /* Send a confirmation to the remote host. */
2560: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2561: packet_put_int(remote_id);
2562: packet_put_int(c->self);
1.51 markus 2563: }
1.113 markus 2564: packet_send();
1.72 markus 2565: }
2566:
2567: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2568: void
1.154 markus 2569: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2570: {
2571: int rchan = packet_get_int();
1.143 deraadt 2572: switch (type) {
1.72 markus 2573: case SSH_SMSG_AGENT_OPEN:
2574: error("Warning: ssh server tried agent forwarding.");
2575: break;
2576: case SSH_SMSG_X11_OPEN:
2577: error("Warning: ssh server tried X11 forwarding.");
2578: break;
2579: default:
1.154 markus 2580: error("deny_input_open: type %d", type);
1.72 markus 2581: break;
2582: }
2583: error("Warning: this is probably a break in attempt by a malicious server.");
2584: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2585: packet_put_int(rchan);
2586: packet_send();
1.1 deraadt 2587: }
2588:
1.27 markus 2589: /*
2590: * Requests forwarding of X11 connections, generates fake authentication
2591: * data, and enables authentication spoofing.
1.121 markus 2592: * This should be called in the client only.
1.27 markus 2593: */
1.49 markus 2594: void
1.51 markus 2595: x11_request_forwarding_with_spoofing(int client_session_id,
2596: const char *proto, const char *data)
1.1 deraadt 2597: {
1.77 markus 2598: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2599: u_int i, value, len;
1.25 markus 2600: char *new_data;
2601: int screen_number;
2602: const char *cp;
2603: u_int32_t rand = 0;
2604:
2605: cp = getenv("DISPLAY");
2606: if (cp)
2607: cp = strchr(cp, ':');
2608: if (cp)
2609: cp = strchr(cp, '.');
2610: if (cp)
2611: screen_number = atoi(cp + 1);
2612: else
2613: screen_number = 0;
2614:
2615: /* Save protocol name. */
2616: x11_saved_proto = xstrdup(proto);
2617:
1.27 markus 2618: /*
2619: * Extract real authentication data and generate fake data of the
2620: * same length.
2621: */
1.25 markus 2622: x11_saved_data = xmalloc(data_len);
2623: x11_fake_data = xmalloc(data_len);
2624: for (i = 0; i < data_len; i++) {
2625: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2626: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2627: if (i % 4 == 0)
2628: rand = arc4random();
2629: x11_saved_data[i] = value;
2630: x11_fake_data[i] = rand & 0xff;
2631: rand >>= 8;
2632: }
2633: x11_saved_data_len = data_len;
2634: x11_fake_data_len = data_len;
2635:
2636: /* Convert the fake data into hex. */
1.90 markus 2637: len = 2 * data_len + 1;
2638: new_data = xmalloc(len);
1.25 markus 2639: for (i = 0; i < data_len; i++)
1.90 markus 2640: snprintf(new_data + 2 * i, len - 2 * i,
2641: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2642:
2643: /* Send the request packet. */
1.51 markus 2644: if (compat20) {
2645: channel_request_start(client_session_id, "x11-req", 0);
2646: packet_put_char(0); /* XXX bool single connection */
2647: } else {
2648: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2649: }
2650: packet_put_cstring(proto);
2651: packet_put_cstring(new_data);
1.25 markus 2652: packet_put_int(screen_number);
2653: packet_send();
2654: packet_write_wait();
2655: xfree(new_data);
1.1 deraadt 2656: }
2657:
1.121 markus 2658:
2659: /* -- agent forwarding */
2660:
1.1 deraadt 2661: /* Sends a message to the server to request authentication fd forwarding. */
2662:
1.49 markus 2663: void
1.142 itojun 2664: auth_request_forwarding(void)
1.1 deraadt 2665: {
1.25 markus 2666: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2667: packet_send();
2668: packet_write_wait();
1.1 deraadt 2669: }
2670:
2671: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2672:
1.49 markus 2673: void
1.154 markus 2674: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2675: {
1.113 markus 2676: Channel *c = NULL;
2677: int remote_id, sock;
1.121 markus 2678: char *name;
1.41 markus 2679:
1.25 markus 2680: /* Read the remote channel number from the message. */
1.113 markus 2681: remote_id = packet_get_int();
1.152 markus 2682: packet_check_eom();
1.25 markus 2683:
1.27 markus 2684: /*
2685: * Get a connection to the local authentication agent (this may again
2686: * get forwarded).
2687: */
1.25 markus 2688: sock = ssh_get_authentication_socket();
2689:
1.27 markus 2690: /*
2691: * If we could not connect the agent, send an error message back to
2692: * the server. This should never happen unless the agent dies,
2693: * because authentication forwarding is only enabled if we have an
2694: * agent.
2695: */
1.113 markus 2696: if (sock >= 0) {
1.121 markus 2697: name = xstrdup("authentication agent connection");
2698: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2699: -1, 0, 0, 0, name, 1);
1.167 markus 2700: c->remote_id = remote_id;
2701: c->force_drain = 1;
1.113 markus 2702: }
2703: if (c == NULL) {
1.25 markus 2704: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2705: packet_put_int(remote_id);
2706: } else {
2707: /* Send a confirmation to the remote host. */
2708: debug("Forwarding authentication connection.");
2709: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2710: packet_put_int(remote_id);
2711: packet_put_int(c->self);
1.25 markus 2712: }
2713: packet_send();
1.1 deraadt 2714: }
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