Annotation of src/usr.bin/ssh/channels.c, Revision 1.160
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"
1.160 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.159 2002/01/14 13:55:55 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"
49: #include "uidswap.h"
1.82 markus 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.82 markus 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.147 stevesk 57: #include "pathnames.h"
1.44 markus 58:
1.1 deraadt 59:
1.121 markus 60: /* -- channel core */
1.12 markus 61:
1.27 markus 62: /*
63: * Pointer to an array containing all allocated channels. The array is
64: * dynamically extended as needed.
65: */
1.113 markus 66: static Channel **channels = NULL;
1.1 deraadt 67:
1.27 markus 68: /*
69: * Size of the channel array. All slots of the array must always be
1.113 markus 70: * initialized (at least the type field); unused slots set to NULL
1.27 markus 71: */
1.1 deraadt 72: static int channels_alloc = 0;
73:
1.27 markus 74: /*
75: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 76: * updated in channel_new.
1.27 markus 77: */
1.84 markus 78: static int channel_max_fd = 0;
1.1 deraadt 79:
80:
1.121 markus 81: /* -- tcp forwarding */
1.1 deraadt 82:
1.27 markus 83: /*
84: * Data structure for storing which hosts are permitted for forward requests.
85: * The local sides of any remote forwards are stored in this array to prevent
86: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
87: * network (which might be behind a firewall).
88: */
1.25 markus 89: typedef struct {
1.41 markus 90: char *host_to_connect; /* Connect to 'host'. */
91: u_short port_to_connect; /* Connect to 'port'. */
92: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 93: } ForwardPermission;
94:
95: /* List of all permitted host/port pairs to connect. */
96: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 97:
1.1 deraadt 98: /* Number of permitted host/port pairs in the array. */
99: static int num_permitted_opens = 0;
1.27 markus 100: /*
101: * If this is true, all opens are permitted. This is the case on the server
102: * on which we have to trust the client anyway, and the user could do
103: * anything after logging in anyway.
104: */
1.1 deraadt 105: static int all_opens_permitted = 0;
106:
1.121 markus 107:
108: /* -- X11 forwarding */
109:
110: /* Maximum number of fake X11 displays to try. */
111: #define MAX_DISPLAYS 1000
112:
113: /* Saved X11 authentication protocol name. */
114: static char *x11_saved_proto = NULL;
115:
116: /* Saved X11 authentication data. This is the real data. */
117: static char *x11_saved_data = NULL;
118: static u_int x11_saved_data_len = 0;
119:
120: /*
121: * Fake X11 authentication data. This is what the server will be sending us;
122: * we should replace any occurrences of this by the real data.
123: */
124: static char *x11_fake_data = NULL;
125: static u_int x11_fake_data_len;
126:
127:
128: /* -- agent forwarding */
129:
130: #define NUM_SOCKS 10
131:
132: /* Name and directory of socket for authentication agent forwarding. */
133: static char *auth_sock_name = NULL;
134: static char *auth_sock_dir = NULL;
135:
1.82 markus 136: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 137: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 138:
1.121 markus 139: /* helper */
1.127 itojun 140: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 141:
1.121 markus 142: /* -- channel core */
1.41 markus 143:
144: Channel *
145: channel_lookup(int id)
146: {
147: Channel *c;
1.113 markus 148:
1.63 provos 149: if (id < 0 || id > channels_alloc) {
1.41 markus 150: log("channel_lookup: %d: bad id", id);
151: return NULL;
152: }
1.113 markus 153: c = channels[id];
154: if (c == NULL) {
1.41 markus 155: log("channel_lookup: %d: bad id: channel free", id);
156: return NULL;
157: }
158: return c;
1.55 markus 159: }
160:
1.27 markus 161: /*
1.55 markus 162: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 163: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 164: */
1.1 deraadt 165:
1.127 itojun 166: static void
1.71 markus 167: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
168: int extusage, int nonblock)
1.1 deraadt 169: {
1.25 markus 170: /* Update the maximum file descriptor value. */
1.84 markus 171: channel_max_fd = MAX(channel_max_fd, rfd);
172: channel_max_fd = MAX(channel_max_fd, wfd);
173: channel_max_fd = MAX(channel_max_fd, efd);
174:
1.27 markus 175: /* XXX set close-on-exec -markus */
1.55 markus 176:
1.52 markus 177: c->rfd = rfd;
178: c->wfd = wfd;
179: c->sock = (rfd == wfd) ? rfd : -1;
180: c->efd = efd;
181: c->extended_usage = extusage;
1.71 markus 182:
1.91 markus 183: /* XXX ugly hack: nonblock is only set by the server */
184: if (nonblock && isatty(c->rfd)) {
1.94 markus 185: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 186: c->isatty = 1;
187: if (!isatty(c->wfd)) {
1.94 markus 188: error("channel %d: wfd %d is not a tty?",
1.91 markus 189: c->self, c->wfd);
190: }
191: } else {
192: c->isatty = 0;
193: }
194:
1.71 markus 195: /* enable nonblocking mode */
196: if (nonblock) {
197: if (rfd != -1)
198: set_nonblock(rfd);
199: if (wfd != -1)
200: set_nonblock(wfd);
201: if (efd != -1)
202: set_nonblock(efd);
203: }
1.52 markus 204: }
205:
206: /*
207: * Allocate a new channel object and set its type and socket. This will cause
208: * remote_name to be freed.
209: */
210:
1.113 markus 211: Channel *
1.52 markus 212: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 213: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 214: {
215: int i, found;
216: Channel *c;
1.25 markus 217:
218: /* Do initial allocation if this is the first call. */
219: if (channels_alloc == 0) {
220: channels_alloc = 10;
1.113 markus 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.113 markus 223: channels[i] = NULL;
1.126 markus 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.113 markus 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 244: memset(c, 0, sizeof(Channel));
1.25 markus 245: buffer_init(&c->input);
246: buffer_init(&c->output);
1.41 markus 247: buffer_init(&c->extended);
1.159 markus 248: c->ostate = CHAN_OUTPUT_OPEN;
249: c->istate = CHAN_INPUT_OPEN;
250: c->flags = 0;
1.71 markus 251: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 252: c->self = found;
253: c->type = type;
1.41 markus 254: c->ctype = ctype;
1.51 markus 255: c->local_window = window;
256: c->local_window_max = window;
257: c->local_consumed = 0;
258: c->local_maxpacket = maxpack;
1.25 markus 259: c->remote_id = -1;
260: c->remote_name = remote_name;
1.41 markus 261: c->remote_window = 0;
262: c->remote_maxpacket = 0;
263: c->cb_fn = NULL;
264: c->cb_arg = NULL;
265: c->cb_event = 0;
1.133 markus 266: c->force_drain = 0;
1.149 markus 267: c->single_connection = 0;
1.131 markus 268: c->detach_user = NULL;
1.65 markus 269: c->input_filter = NULL;
1.25 markus 270: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 271: return c;
1.1 deraadt 272: }
1.52 markus 273:
1.132 markus 274: static int
275: channel_find_maxfd(void)
276: {
277: int i, max = 0;
278: Channel *c;
279:
280: for (i = 0; i < channels_alloc; i++) {
281: c = channels[i];
282: if (c != NULL) {
283: max = MAX(max, c->rfd);
284: max = MAX(max, c->wfd);
285: max = MAX(max, c->efd);
286: }
287: }
288: return max;
289: }
290:
291: int
292: channel_close_fd(int *fdp)
293: {
294: int ret = 0, fd = *fdp;
295:
296: if (fd != -1) {
297: ret = close(fd);
298: *fdp = -1;
299: if (fd == channel_max_fd)
300: channel_max_fd = channel_find_maxfd();
301: }
302: return ret;
303: }
304:
1.52 markus 305: /* Close all channel fd/socket. */
306:
1.127 itojun 307: static void
1.52 markus 308: channel_close_fds(Channel *c)
309: {
1.118 markus 310: debug3("channel_close_fds: channel %d: r %d w %d e %d",
311: c->self, c->rfd, c->wfd, c->efd);
312:
1.132 markus 313: channel_close_fd(&c->sock);
314: channel_close_fd(&c->rfd);
315: channel_close_fd(&c->wfd);
316: channel_close_fd(&c->efd);
1.121 markus 317: }
318:
319: /* Free the channel and close its fd/socket. */
320:
321: void
322: channel_free(Channel *c)
323: {
324: char *s;
325: int i, n;
326:
327: for (n = 0, i = 0; i < channels_alloc; i++)
328: if (channels[i])
329: n++;
330: debug("channel_free: channel %d: %s, nchannels %d", c->self,
331: c->remote_name ? c->remote_name : "???", n);
332:
333: s = channel_open_message();
334: debug3("channel_free: status: %s", s);
335: xfree(s);
336:
337: if (c->sock != -1)
338: shutdown(c->sock, SHUT_RDWR);
339: channel_close_fds(c);
340: buffer_free(&c->input);
341: buffer_free(&c->output);
342: buffer_free(&c->extended);
343: if (c->remote_name) {
344: xfree(c->remote_name);
345: c->remote_name = NULL;
346: }
347: channels[c->self] = NULL;
348: xfree(c);
349: }
350:
351: void
1.126 markus 352: channel_free_all(void)
1.121 markus 353: {
354: int i;
355:
1.126 markus 356: for (i = 0; i < channels_alloc; i++)
357: if (channels[i] != NULL)
358: channel_free(channels[i]);
1.131 markus 359: }
360:
1.121 markus 361: /*
362: * Closes the sockets/fds of all channels. This is used to close extra file
363: * descriptors after a fork.
364: */
365:
366: void
1.142 itojun 367: channel_close_all(void)
1.121 markus 368: {
369: int i;
370:
371: for (i = 0; i < channels_alloc; i++)
372: if (channels[i] != NULL)
373: channel_close_fds(channels[i]);
374: }
375:
376: /*
1.131 markus 377: * Stop listening to channels.
378: */
379:
380: void
381: channel_stop_listening(void)
382: {
383: int i;
384: Channel *c;
385:
386: for (i = 0; i < channels_alloc; i++) {
387: c = channels[i];
388: if (c != NULL) {
389: switch (c->type) {
390: case SSH_CHANNEL_AUTH_SOCKET:
391: case SSH_CHANNEL_PORT_LISTENER:
392: case SSH_CHANNEL_RPORT_LISTENER:
393: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 394: channel_close_fd(&c->sock);
1.131 markus 395: channel_free(c);
396: break;
397: }
398: }
399: }
400: }
401:
402: /*
1.121 markus 403: * Returns true if no channel has too much buffered data, and false if one or
404: * more channel is overfull.
405: */
406:
407: int
1.142 itojun 408: channel_not_very_much_buffered_data(void)
1.121 markus 409: {
410: u_int i;
411: Channel *c;
412:
413: for (i = 0; i < channels_alloc; i++) {
414: c = channels[i];
415: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 416: #if 0
417: if (!compat20 &&
418: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 419: debug("channel %d: big input buffer %d",
420: c->self, buffer_len(&c->input));
421: return 0;
422: }
1.136 markus 423: #endif
1.121 markus 424: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 425: debug("channel %d: big output buffer %d > %d",
426: c->self, buffer_len(&c->output),
427: packet_get_maxsize());
1.121 markus 428: return 0;
429: }
430: }
431: }
432: return 1;
433: }
434:
435: /* Returns true if any channel is still open. */
436:
437: int
1.142 itojun 438: channel_still_open(void)
1.121 markus 439: {
440: int i;
441: Channel *c;
442:
443: for (i = 0; i < channels_alloc; i++) {
444: c = channels[i];
445: if (c == NULL)
446: continue;
447: switch (c->type) {
448: case SSH_CHANNEL_X11_LISTENER:
449: case SSH_CHANNEL_PORT_LISTENER:
450: case SSH_CHANNEL_RPORT_LISTENER:
451: case SSH_CHANNEL_CLOSED:
452: case SSH_CHANNEL_AUTH_SOCKET:
453: case SSH_CHANNEL_DYNAMIC:
454: case SSH_CHANNEL_CONNECTING:
455: case SSH_CHANNEL_ZOMBIE:
456: continue;
457: case SSH_CHANNEL_LARVAL:
458: if (!compat20)
459: fatal("cannot happen: SSH_CHANNEL_LARVAL");
460: continue;
461: case SSH_CHANNEL_OPENING:
462: case SSH_CHANNEL_OPEN:
463: case SSH_CHANNEL_X11_OPEN:
464: return 1;
465: case SSH_CHANNEL_INPUT_DRAINING:
466: case SSH_CHANNEL_OUTPUT_DRAINING:
467: if (!compat13)
468: fatal("cannot happen: OUT_DRAIN");
469: return 1;
470: default:
471: fatal("channel_still_open: bad channel type %d", c->type);
472: /* NOTREACHED */
473: }
474: }
475: return 0;
476: }
477:
478: /* Returns the id of an open channel suitable for keepaliving */
479:
480: int
1.142 itojun 481: channel_find_open(void)
1.121 markus 482: {
483: int i;
484: Channel *c;
485:
486: for (i = 0; i < channels_alloc; i++) {
487: c = channels[i];
488: if (c == NULL)
489: continue;
490: switch (c->type) {
491: case SSH_CHANNEL_CLOSED:
492: case SSH_CHANNEL_DYNAMIC:
493: case SSH_CHANNEL_X11_LISTENER:
494: case SSH_CHANNEL_PORT_LISTENER:
495: case SSH_CHANNEL_RPORT_LISTENER:
496: case SSH_CHANNEL_OPENING:
497: case SSH_CHANNEL_CONNECTING:
498: case SSH_CHANNEL_ZOMBIE:
499: continue;
500: case SSH_CHANNEL_LARVAL:
501: case SSH_CHANNEL_AUTH_SOCKET:
502: case SSH_CHANNEL_OPEN:
503: case SSH_CHANNEL_X11_OPEN:
504: return i;
505: case SSH_CHANNEL_INPUT_DRAINING:
506: case SSH_CHANNEL_OUTPUT_DRAINING:
507: if (!compat13)
508: fatal("cannot happen: OUT_DRAIN");
509: return i;
510: default:
511: fatal("channel_find_open: bad channel type %d", c->type);
512: /* NOTREACHED */
513: }
514: }
515: return -1;
516: }
517:
518:
519: /*
520: * Returns a message describing the currently open forwarded connections,
521: * suitable for sending to the client. The message contains crlf pairs for
522: * newlines.
523: */
524:
525: char *
1.142 itojun 526: channel_open_message(void)
1.121 markus 527: {
528: Buffer buffer;
529: Channel *c;
530: char buf[1024], *cp;
531: int i;
532:
533: buffer_init(&buffer);
534: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
535: buffer_append(&buffer, buf, strlen(buf));
536: for (i = 0; i < channels_alloc; i++) {
537: c = channels[i];
538: if (c == NULL)
539: continue;
540: switch (c->type) {
541: case SSH_CHANNEL_X11_LISTENER:
542: case SSH_CHANNEL_PORT_LISTENER:
543: case SSH_CHANNEL_RPORT_LISTENER:
544: case SSH_CHANNEL_CLOSED:
545: case SSH_CHANNEL_AUTH_SOCKET:
546: case SSH_CHANNEL_ZOMBIE:
547: continue;
548: case SSH_CHANNEL_LARVAL:
549: case SSH_CHANNEL_OPENING:
550: case SSH_CHANNEL_CONNECTING:
551: case SSH_CHANNEL_DYNAMIC:
552: case SSH_CHANNEL_OPEN:
553: case SSH_CHANNEL_X11_OPEN:
554: case SSH_CHANNEL_INPUT_DRAINING:
555: case SSH_CHANNEL_OUTPUT_DRAINING:
556: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
557: c->self, c->remote_name,
558: c->type, c->remote_id,
559: c->istate, buffer_len(&c->input),
560: c->ostate, buffer_len(&c->output),
561: c->rfd, c->wfd);
562: buffer_append(&buffer, buf, strlen(buf));
563: continue;
564: default:
565: fatal("channel_open_message: bad channel type %d", c->type);
566: /* NOTREACHED */
567: }
568: }
569: buffer_append(&buffer, "\0", 1);
570: cp = xstrdup(buffer_ptr(&buffer));
571: buffer_free(&buffer);
572: return cp;
573: }
574:
575: void
576: channel_send_open(int id)
577: {
578: Channel *c = channel_lookup(id);
579: if (c == NULL) {
580: log("channel_send_open: %d: bad id", id);
581: return;
582: }
583: debug("send channel open %d", id);
584: packet_start(SSH2_MSG_CHANNEL_OPEN);
585: packet_put_cstring(c->ctype);
586: packet_put_int(c->self);
587: packet_put_int(c->local_window);
588: packet_put_int(c->local_maxpacket);
589: packet_send();
590: }
591:
592: void
593: channel_request(int id, char *service, int wantconfirm)
594: {
595: channel_request_start(id, service, wantconfirm);
596: packet_send();
597: debug("channel request %d: %s", id, service) ;
598: }
599: void
600: channel_request_start(int id, char *service, int wantconfirm)
601: {
602: Channel *c = channel_lookup(id);
603: if (c == NULL) {
604: log("channel_request: %d: bad id", id);
605: return;
606: }
607: packet_start(SSH2_MSG_CHANNEL_REQUEST);
608: packet_put_int(c->remote_id);
609: packet_put_cstring(service);
610: packet_put_char(wantconfirm);
611: }
612: void
613: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
614: {
615: Channel *c = channel_lookup(id);
616: if (c == NULL) {
617: log("channel_register_callback: %d: bad id", id);
618: return;
619: }
620: c->cb_event = mtype;
621: c->cb_fn = fn;
622: c->cb_arg = arg;
623: }
624: void
625: channel_register_cleanup(int id, channel_callback_fn *fn)
626: {
627: Channel *c = channel_lookup(id);
628: if (c == NULL) {
629: log("channel_register_cleanup: %d: bad id", id);
630: return;
631: }
1.131 markus 632: c->detach_user = fn;
1.121 markus 633: }
634: void
635: channel_cancel_cleanup(int id)
636: {
637: Channel *c = channel_lookup(id);
638: if (c == NULL) {
639: log("channel_cancel_cleanup: %d: bad id", id);
640: return;
1.52 markus 641: }
1.131 markus 642: c->detach_user = NULL;
1.121 markus 643: }
644: void
645: channel_register_filter(int id, channel_filter_fn *fn)
646: {
647: Channel *c = channel_lookup(id);
648: if (c == NULL) {
649: log("channel_register_filter: %d: bad id", id);
650: return;
1.52 markus 651: }
1.121 markus 652: c->input_filter = fn;
1.52 markus 653: }
654:
1.49 markus 655: void
1.121 markus 656: channel_set_fds(int id, int rfd, int wfd, int efd,
657: int extusage, int nonblock)
1.1 deraadt 658: {
1.121 markus 659: Channel *c = channel_lookup(id);
660: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
661: fatal("channel_activate for non-larval channel %d.", id);
662: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
663: c->type = SSH_CHANNEL_OPEN;
664: /* XXX window size? */
665: c->local_window = c->local_window_max = c->local_maxpacket * 2;
666: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
667: packet_put_int(c->remote_id);
668: packet_put_int(c->local_window);
669: packet_send();
1.1 deraadt 670: }
671:
1.27 markus 672: /*
1.41 markus 673: * 'channel_pre*' are called just before select() to add any bits relevant to
674: * channels in the select bitmasks.
675: */
676: /*
677: * 'channel_post*': perform any appropriate operations for channels which
678: * have events pending.
1.27 markus 679: */
1.41 markus 680: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
681: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
682: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
683:
1.127 itojun 684: static void
1.41 markus 685: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
686: {
687: FD_SET(c->sock, readset);
688: }
689:
1.127 itojun 690: static void
1.75 markus 691: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
692: {
693: debug3("channel %d: waiting for connection", c->self);
694: FD_SET(c->sock, writeset);
695: }
696:
1.127 itojun 697: static void
1.41 markus 698: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
699: {
700: if (buffer_len(&c->input) < packet_get_maxsize())
701: FD_SET(c->sock, readset);
702: if (buffer_len(&c->output) > 0)
703: FD_SET(c->sock, writeset);
704: }
1.1 deraadt 705:
1.127 itojun 706: static void
1.157 markus 707: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 708: {
1.157 markus 709: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 710:
1.44 markus 711: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 712: limit > 0 &&
713: buffer_len(&c->input) < limit)
1.44 markus 714: FD_SET(c->rfd, readset);
715: if (c->ostate == CHAN_OUTPUT_OPEN ||
716: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
717: if (buffer_len(&c->output) > 0) {
718: FD_SET(c->wfd, writeset);
719: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
720: chan_obuf_empty(c);
721: }
722: }
723: /** XXX check close conditions, too */
1.157 markus 724: if (compat20 && c->efd != -1) {
1.44 markus 725: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
726: buffer_len(&c->extended) > 0)
727: FD_SET(c->efd, writeset);
728: else if (c->extended_usage == CHAN_EXTENDED_READ &&
729: buffer_len(&c->extended) < c->remote_window)
730: FD_SET(c->efd, readset);
731: }
732: }
733:
1.127 itojun 734: static void
1.41 markus 735: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
736: {
737: if (buffer_len(&c->input) == 0) {
738: packet_start(SSH_MSG_CHANNEL_CLOSE);
739: packet_put_int(c->remote_id);
740: packet_send();
741: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 742: debug("channel %d: closing after input drain.", c->self);
1.41 markus 743: }
744: }
745:
1.127 itojun 746: static void
1.41 markus 747: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
748: {
749: if (buffer_len(&c->output) == 0)
1.113 markus 750: chan_mark_dead(c);
1.49 markus 751: else
1.41 markus 752: FD_SET(c->sock, writeset);
753: }
754:
755: /*
756: * This is a special state for X11 authentication spoofing. An opened X11
757: * connection (when authentication spoofing is being done) remains in this
758: * state until the first packet has been completely read. The authentication
759: * data in that packet is then substituted by the real data if it matches the
760: * fake data, and the channel is put into normal mode.
1.51 markus 761: * XXX All this happens at the client side.
1.121 markus 762: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 763: */
1.127 itojun 764: static int
1.121 markus 765: x11_open_helper(Buffer *b)
1.1 deraadt 766: {
1.77 markus 767: u_char *ucp;
768: u_int proto_len, data_len;
1.25 markus 769:
1.41 markus 770: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 771: if (buffer_len(b) < 12)
1.41 markus 772: return 0;
773:
774: /* Parse the lengths of variable-length fields. */
1.155 stevesk 775: ucp = buffer_ptr(b);
1.41 markus 776: if (ucp[0] == 0x42) { /* Byte order MSB first. */
777: proto_len = 256 * ucp[6] + ucp[7];
778: data_len = 256 * ucp[8] + ucp[9];
779: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
780: proto_len = ucp[6] + 256 * ucp[7];
781: data_len = ucp[8] + 256 * ucp[9];
782: } else {
783: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 784: ucp[0]);
1.41 markus 785: return -1;
786: }
787:
788: /* Check if the whole packet is in buffer. */
1.121 markus 789: if (buffer_len(b) <
1.41 markus 790: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
791: return 0;
792:
793: /* Check if authentication protocol matches. */
794: if (proto_len != strlen(x11_saved_proto) ||
795: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
796: debug("X11 connection uses different authentication protocol.");
797: return -1;
798: }
799: /* Check if authentication data matches our fake data. */
800: if (data_len != x11_fake_data_len ||
801: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
802: x11_fake_data, x11_fake_data_len) != 0) {
803: debug("X11 auth data does not match fake data.");
804: return -1;
805: }
806: /* Check fake data length */
807: if (x11_fake_data_len != x11_saved_data_len) {
808: error("X11 fake_data_len %d != saved_data_len %d",
809: x11_fake_data_len, x11_saved_data_len);
810: return -1;
811: }
812: /*
813: * Received authentication protocol and data match
814: * our fake data. Substitute the fake data with real
815: * data.
816: */
817: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
818: x11_saved_data, x11_saved_data_len);
819: return 1;
820: }
821:
1.127 itojun 822: static void
1.41 markus 823: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
824: {
1.121 markus 825: int ret = x11_open_helper(&c->output);
1.41 markus 826: if (ret == 1) {
827: /* Start normal processing for the channel. */
828: c->type = SSH_CHANNEL_OPEN;
1.47 markus 829: channel_pre_open_13(c, readset, writeset);
1.41 markus 830: } else if (ret == -1) {
831: /*
832: * We have received an X11 connection that has bad
833: * authentication information.
834: */
1.98 millert 835: log("X11 connection rejected because of wrong authentication.");
1.41 markus 836: buffer_clear(&c->input);
837: buffer_clear(&c->output);
1.132 markus 838: channel_close_fd(&c->sock);
1.41 markus 839: c->sock = -1;
840: c->type = SSH_CHANNEL_CLOSED;
841: packet_start(SSH_MSG_CHANNEL_CLOSE);
842: packet_put_int(c->remote_id);
843: packet_send();
844: }
845: }
1.25 markus 846:
1.127 itojun 847: static void
1.51 markus 848: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 849: {
1.121 markus 850: int ret = x11_open_helper(&c->output);
1.133 markus 851:
852: /* c->force_drain = 1; */
853:
1.41 markus 854: if (ret == 1) {
855: c->type = SSH_CHANNEL_OPEN;
1.157 markus 856: channel_pre_open(c, readset, writeset);
1.41 markus 857: } else if (ret == -1) {
1.156 markus 858: log("X11 connection rejected because of wrong authentication.");
1.41 markus 859: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 860: chan_read_failed(c);
861: buffer_clear(&c->input);
862: chan_ibuf_empty(c);
863: buffer_clear(&c->output);
864: /* for proto v1, the peer will send an IEOF */
865: if (compat20)
866: chan_write_failed(c);
867: else
868: c->type = SSH_CHANNEL_OPEN;
1.41 markus 869: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
870: }
871: }
1.25 markus 872:
1.104 markus 873: /* try to decode a socks4 header */
1.127 itojun 874: static int
1.104 markus 875: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 876: {
877: u_char *p, *host;
1.109 markus 878: int len, have, i, found;
1.148 deraadt 879: char username[256];
1.103 markus 880: struct {
881: u_int8_t version;
882: u_int8_t command;
883: u_int16_t dest_port;
1.104 markus 884: struct in_addr dest_addr;
1.103 markus 885: } s4_req, s4_rsp;
886:
1.104 markus 887: debug2("channel %d: decode socks4", c->self);
1.109 markus 888:
889: have = buffer_len(&c->input);
890: len = sizeof(s4_req);
891: if (have < len)
892: return 0;
893: p = buffer_ptr(&c->input);
894: for (found = 0, i = len; i < have; i++) {
895: if (p[i] == '\0') {
896: found = 1;
897: break;
898: }
899: if (i > 1024) {
900: /* the peer is probably sending garbage */
901: debug("channel %d: decode socks4: too long",
902: c->self);
903: return -1;
904: }
905: }
906: if (!found)
907: return 0;
1.103 markus 908: buffer_get(&c->input, (char *)&s4_req.version, 1);
909: buffer_get(&c->input, (char *)&s4_req.command, 1);
910: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 911: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 912: have = buffer_len(&c->input);
1.103 markus 913: p = buffer_ptr(&c->input);
914: len = strlen(p);
1.106 markus 915: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 916: if (len > have)
1.104 markus 917: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 918: c->self, len, have);
919: strlcpy(username, p, sizeof(username));
920: buffer_consume(&c->input, len);
921: buffer_consume(&c->input, 1); /* trailing '\0' */
922:
1.104 markus 923: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 924: strlcpy(c->path, host, sizeof(c->path));
925: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 926:
1.106 markus 927: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
928: c->self, host, c->host_port, s4_req.command);
1.103 markus 929:
1.104 markus 930: if (s4_req.command != 1) {
931: debug("channel %d: cannot handle: socks4 cn %d",
932: c->self, s4_req.command);
933: return -1;
1.103 markus 934: }
1.104 markus 935: s4_rsp.version = 0; /* vn: 0 for reply */
936: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 937: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 938: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 939: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 940: return 1;
941: }
942:
943: /* dynamic port forwarding */
1.127 itojun 944: static void
1.104 markus 945: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
946: {
947: u_char *p;
948: int have, ret;
1.103 markus 949:
1.104 markus 950: have = buffer_len(&c->input);
1.137 markus 951: c->delayed = 0;
1.104 markus 952: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 953: /* buffer_dump(&c->input); */
1.104 markus 954: /* check if the fixed size part of the packet is in buffer. */
955: if (have < 4) {
956: /* need more */
957: FD_SET(c->sock, readset);
958: return;
959: }
960: /* try to guess the protocol */
961: p = buffer_ptr(&c->input);
962: switch (p[0]) {
963: case 0x04:
964: ret = channel_decode_socks4(c, readset, writeset);
965: break;
966: default:
967: ret = -1;
968: break;
969: }
970: if (ret < 0) {
1.113 markus 971: chan_mark_dead(c);
1.104 markus 972: } else if (ret == 0) {
973: debug2("channel %d: pre_dynamic: need more", c->self);
974: /* need more */
975: FD_SET(c->sock, readset);
976: } else {
977: /* switch to the next state */
978: c->type = SSH_CHANNEL_OPENING;
979: port_open_helper(c, "direct-tcpip");
980: }
1.103 markus 981: }
982:
1.41 markus 983: /* This is our fake X11 server socket. */
1.127 itojun 984: static void
1.41 markus 985: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
986: {
1.113 markus 987: Channel *nc;
1.41 markus 988: struct sockaddr addr;
1.146 stevesk 989: int newsock, on = 1;
1.41 markus 990: socklen_t addrlen;
1.85 markus 991: char buf[16384], *remote_ipaddr;
1.51 markus 992: int remote_port;
1.25 markus 993:
1.41 markus 994: if (FD_ISSET(c->sock, readset)) {
995: debug("X11 connection requested.");
996: addrlen = sizeof(addr);
997: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 998: if (c->single_connection) {
999: debug("single_connection: closing X11 listener.");
1000: channel_close_fd(&c->sock);
1001: chan_mark_dead(c);
1002: }
1.41 markus 1003: if (newsock < 0) {
1004: error("accept: %.100s", strerror(errno));
1005: return;
1006: }
1.146 stevesk 1007: if (setsockopt(newsock, IPPROTO_TCP, TCP_NODELAY, &on,
1008: sizeof on) == -1)
1009: error("setsockopt TCP_NODELAY: %.100s",
1010: strerror(errno));
1.85 markus 1011: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1012: remote_port = get_peer_port(newsock);
1.41 markus 1013: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1014: remote_ipaddr, remote_port);
1.51 markus 1015:
1.113 markus 1016: nc = channel_new("accepted x11 socket",
1.51 markus 1017: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1018: c->local_window_max, c->local_maxpacket,
1.71 markus 1019: 0, xstrdup(buf), 1);
1.113 markus 1020: if (nc == NULL) {
1021: close(newsock);
1022: xfree(remote_ipaddr);
1023: return;
1024: }
1.51 markus 1025: if (compat20) {
1026: packet_start(SSH2_MSG_CHANNEL_OPEN);
1027: packet_put_cstring("x11");
1.113 markus 1028: packet_put_int(nc->self);
1.149 markus 1029: packet_put_int(nc->local_window_max);
1030: packet_put_int(nc->local_maxpacket);
1.85 markus 1031: /* originator ipaddr and port */
1032: packet_put_cstring(remote_ipaddr);
1.57 markus 1033: if (datafellows & SSH_BUG_X11FWD) {
1034: debug("ssh2 x11 bug compat mode");
1035: } else {
1036: packet_put_int(remote_port);
1037: }
1.51 markus 1038: packet_send();
1039: } else {
1040: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1041: packet_put_int(nc->self);
1.121 markus 1042: if (packet_get_protocol_flags() &
1043: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1044: packet_put_cstring(buf);
1.51 markus 1045: packet_send();
1046: }
1.85 markus 1047: xfree(remote_ipaddr);
1.41 markus 1048: }
1049: }
1.25 markus 1050:
1.127 itojun 1051: static void
1.103 markus 1052: port_open_helper(Channel *c, char *rtype)
1053: {
1054: int direct;
1055: char buf[1024];
1056: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1057: u_short remote_port = get_peer_port(c->sock);
1058:
1059: direct = (strcmp(rtype, "direct-tcpip") == 0);
1060:
1061: snprintf(buf, sizeof buf,
1062: "%s: listening port %d for %.100s port %d, "
1063: "connect from %.200s port %d",
1064: rtype, c->listening_port, c->path, c->host_port,
1065: remote_ipaddr, remote_port);
1066:
1067: xfree(c->remote_name);
1068: c->remote_name = xstrdup(buf);
1069:
1070: if (compat20) {
1071: packet_start(SSH2_MSG_CHANNEL_OPEN);
1072: packet_put_cstring(rtype);
1073: packet_put_int(c->self);
1074: packet_put_int(c->local_window_max);
1075: packet_put_int(c->local_maxpacket);
1076: if (direct) {
1077: /* target host, port */
1078: packet_put_cstring(c->path);
1079: packet_put_int(c->host_port);
1080: } else {
1081: /* listen address, port */
1082: packet_put_cstring(c->path);
1083: packet_put_int(c->listening_port);
1084: }
1085: /* originator host and port */
1086: packet_put_cstring(remote_ipaddr);
1087: packet_put_int(remote_port);
1088: packet_send();
1089: } else {
1090: packet_start(SSH_MSG_PORT_OPEN);
1091: packet_put_int(c->self);
1092: packet_put_cstring(c->path);
1093: packet_put_int(c->host_port);
1.121 markus 1094: if (packet_get_protocol_flags() &
1095: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1096: packet_put_cstring(c->remote_name);
1097: packet_send();
1098: }
1099: xfree(remote_ipaddr);
1100: }
1101:
1.41 markus 1102: /*
1103: * This socket is listening for connections to a forwarded TCP/IP port.
1104: */
1.127 itojun 1105: static void
1.41 markus 1106: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1107: {
1.103 markus 1108: Channel *nc;
1.41 markus 1109: struct sockaddr addr;
1.113 markus 1110: int newsock, nextstate;
1.41 markus 1111: socklen_t addrlen;
1.103 markus 1112: char *rtype;
1.73 markus 1113:
1.41 markus 1114: if (FD_ISSET(c->sock, readset)) {
1115: debug("Connection to port %d forwarding "
1116: "to %.100s port %d requested.",
1117: c->listening_port, c->path, c->host_port);
1.103 markus 1118:
1.137 markus 1119: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1120: nextstate = SSH_CHANNEL_OPENING;
1121: rtype = "forwarded-tcpip";
1122: } else {
1123: if (c->host_port == 0) {
1124: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1125: rtype = "dynamic-tcpip";
1.137 markus 1126: } else {
1127: nextstate = SSH_CHANNEL_OPENING;
1128: rtype = "direct-tcpip";
1129: }
1130: }
1.103 markus 1131:
1.41 markus 1132: addrlen = sizeof(addr);
1133: newsock = accept(c->sock, &addr, &addrlen);
1134: if (newsock < 0) {
1135: error("accept: %.100s", strerror(errno));
1136: return;
1137: }
1.113 markus 1138: nc = channel_new(rtype,
1.103 markus 1139: nextstate, newsock, newsock, -1,
1.41 markus 1140: c->local_window_max, c->local_maxpacket,
1.103 markus 1141: 0, xstrdup(rtype), 1);
1142: if (nc == NULL) {
1.113 markus 1143: error("channel_post_port_listener: no new channel:");
1144: close(newsock);
1.103 markus 1145: return;
1.41 markus 1146: }
1.103 markus 1147: nc->listening_port = c->listening_port;
1148: nc->host_port = c->host_port;
1149: strlcpy(nc->path, c->path, sizeof(nc->path));
1150:
1.137 markus 1151: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1152: /*
1153: * do not call the channel_post handler until
1154: * this flag has been reset by a pre-handler.
1155: * otherwise the FD_ISSET calls might overflow
1156: */
1157: nc->delayed = 1;
1158: } else {
1.103 markus 1159: port_open_helper(nc, rtype);
1.137 markus 1160: }
1.41 markus 1161: }
1162: }
1.25 markus 1163:
1.41 markus 1164: /*
1165: * This is the authentication agent socket listening for connections from
1166: * clients.
1167: */
1.127 itojun 1168: static void
1.41 markus 1169: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1170: {
1.113 markus 1171: Channel *nc;
1.121 markus 1172: char *name;
1.113 markus 1173: int newsock;
1.41 markus 1174: struct sockaddr addr;
1175: socklen_t addrlen;
1.25 markus 1176:
1.41 markus 1177: if (FD_ISSET(c->sock, readset)) {
1178: addrlen = sizeof(addr);
1179: newsock = accept(c->sock, &addr, &addrlen);
1180: if (newsock < 0) {
1181: error("accept from auth socket: %.100s", strerror(errno));
1182: return;
1183: }
1.121 markus 1184: name = xstrdup("accepted auth socket");
1.113 markus 1185: nc = channel_new("accepted auth socket",
1.73 markus 1186: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1187: c->local_window_max, c->local_maxpacket,
1.121 markus 1188: 0, name, 1);
1.113 markus 1189: if (nc == NULL) {
1190: error("channel_post_auth_listener: channel_new failed");
1.121 markus 1191: xfree(name);
1.113 markus 1192: close(newsock);
1193: }
1.73 markus 1194: if (compat20) {
1195: packet_start(SSH2_MSG_CHANNEL_OPEN);
1196: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1197: packet_put_int(nc->self);
1.73 markus 1198: packet_put_int(c->local_window_max);
1199: packet_put_int(c->local_maxpacket);
1200: } else {
1201: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1202: packet_put_int(nc->self);
1.73 markus 1203: }
1.41 markus 1204: packet_send();
1205: }
1206: }
1.25 markus 1207:
1.127 itojun 1208: static void
1.75 markus 1209: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1210: {
1.114 markus 1211: int err = 0;
1.129 stevesk 1212: socklen_t sz = sizeof(err);
1.114 markus 1213:
1.75 markus 1214: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1215: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1216: &sz) < 0) {
1217: err = errno;
1218: error("getsockopt SO_ERROR failed");
1219: }
1220: if (err == 0) {
1221: debug("channel %d: connected", c->self);
1222: c->type = SSH_CHANNEL_OPEN;
1223: if (compat20) {
1224: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1225: packet_put_int(c->remote_id);
1226: packet_put_int(c->self);
1227: packet_put_int(c->local_window);
1228: packet_put_int(c->local_maxpacket);
1229: } else {
1230: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1231: packet_put_int(c->remote_id);
1232: packet_put_int(c->self);
1233: }
1.75 markus 1234: } else {
1.114 markus 1235: debug("channel %d: not connected: %s",
1236: c->self, strerror(err));
1237: if (compat20) {
1238: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1239: packet_put_int(c->remote_id);
1240: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1241: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1242: packet_put_cstring(strerror(err));
1243: packet_put_cstring("");
1244: }
1.75 markus 1245: } else {
1.114 markus 1246: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1247: packet_put_int(c->remote_id);
1.75 markus 1248: }
1.114 markus 1249: chan_mark_dead(c);
1.75 markus 1250: }
1.114 markus 1251: packet_send();
1.75 markus 1252: }
1253: }
1254:
1.127 itojun 1255: static int
1.41 markus 1256: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1257: {
1258: char buf[16*1024];
1259: int len;
1.25 markus 1260:
1.118 markus 1261: if (c->rfd != -1 &&
1.41 markus 1262: FD_ISSET(c->rfd, readset)) {
1263: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1264: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1265: return 1;
1.41 markus 1266: if (len <= 0) {
1.51 markus 1267: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1268: c->self, c->rfd, len);
1.104 markus 1269: if (c->type != SSH_CHANNEL_OPEN) {
1270: debug("channel %d: not open", c->self);
1.113 markus 1271: chan_mark_dead(c);
1.103 markus 1272: return -1;
1.104 markus 1273: } else if (compat13) {
1.158 markus 1274: buffer_clear(&c->output);
1.41 markus 1275: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1276: debug("channel %d: input draining.", c->self);
1.25 markus 1277: } else {
1.41 markus 1278: chan_read_failed(c);
1.25 markus 1279: }
1.41 markus 1280: return -1;
1281: }
1.143 deraadt 1282: if (c->input_filter != NULL) {
1.66 markus 1283: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1284: debug("channel %d: filter stops", c->self);
1.65 markus 1285: chan_read_failed(c);
1286: }
1287: } else {
1288: buffer_append(&c->input, buf, len);
1289: }
1.41 markus 1290: }
1291: return 1;
1292: }
1.127 itojun 1293: static int
1.41 markus 1294: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1295: {
1.95 markus 1296: struct termios tio;
1.134 markus 1297: u_char *data;
1298: u_int dlen;
1.41 markus 1299: int len;
1.25 markus 1300:
1.41 markus 1301: /* Send buffered output data to the socket. */
1.118 markus 1302: if (c->wfd != -1 &&
1.41 markus 1303: FD_ISSET(c->wfd, writeset) &&
1304: buffer_len(&c->output) > 0) {
1.134 markus 1305: data = buffer_ptr(&c->output);
1306: dlen = buffer_len(&c->output);
1307: len = write(c->wfd, data, dlen);
1.53 markus 1308: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1309: return 1;
1.41 markus 1310: if (len <= 0) {
1.104 markus 1311: if (c->type != SSH_CHANNEL_OPEN) {
1312: debug("channel %d: not open", c->self);
1.113 markus 1313: chan_mark_dead(c);
1.104 markus 1314: return -1;
1315: } else if (compat13) {
1.158 markus 1316: buffer_clear(&c->output);
1.121 markus 1317: debug("channel %d: input draining.", c->self);
1.41 markus 1318: c->type = SSH_CHANNEL_INPUT_DRAINING;
1319: } else {
1320: chan_write_failed(c);
1321: }
1322: return -1;
1.91 markus 1323: }
1.134 markus 1324: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1325: if (tcgetattr(c->wfd, &tio) == 0 &&
1326: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1327: /*
1328: * Simulate echo to reduce the impact of
1.96 markus 1329: * traffic analysis. We need to match the
1.95 markus 1330: * size of a SSH2_MSG_CHANNEL_DATA message
1331: * (4 byte channel id + data)
1.91 markus 1332: */
1.95 markus 1333: packet_send_ignore(4 + len);
1.91 markus 1334: packet_send();
1335: }
1.25 markus 1336: }
1.41 markus 1337: buffer_consume(&c->output, len);
1.44 markus 1338: if (compat20 && len > 0) {
1339: c->local_consumed += len;
1340: }
1341: }
1342: return 1;
1343: }
1.127 itojun 1344: static int
1.44 markus 1345: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1346: {
1347: char buf[16*1024];
1348: int len;
1349:
1.45 markus 1350: /** XXX handle drain efd, too */
1.44 markus 1351: if (c->efd != -1) {
1352: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1353: FD_ISSET(c->efd, writeset) &&
1354: buffer_len(&c->extended) > 0) {
1355: len = write(c->efd, buffer_ptr(&c->extended),
1356: buffer_len(&c->extended));
1.70 markus 1357: debug2("channel %d: written %d to efd %d",
1.44 markus 1358: c->self, len, c->efd);
1.93 markus 1359: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1360: return 1;
1361: if (len <= 0) {
1362: debug2("channel %d: closing write-efd %d",
1363: c->self, c->efd);
1.132 markus 1364: channel_close_fd(&c->efd);
1.93 markus 1365: } else {
1.44 markus 1366: buffer_consume(&c->extended, len);
1367: c->local_consumed += len;
1368: }
1369: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1370: FD_ISSET(c->efd, readset)) {
1371: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1372: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1373: c->self, len, c->efd);
1.93 markus 1374: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1375: return 1;
1376: if (len <= 0) {
1377: debug2("channel %d: closing read-efd %d",
1.45 markus 1378: c->self, c->efd);
1.132 markus 1379: channel_close_fd(&c->efd);
1.93 markus 1380: } else {
1.44 markus 1381: buffer_append(&c->extended, buf, len);
1.93 markus 1382: }
1.44 markus 1383: }
1384: }
1385: return 1;
1386: }
1.127 itojun 1387: static int
1.93 markus 1388: channel_check_window(Channel *c)
1.44 markus 1389: {
1.104 markus 1390: if (c->type == SSH_CHANNEL_OPEN &&
1391: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1392: c->local_window < c->local_window_max/2 &&
1393: c->local_consumed > 0) {
1394: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1395: packet_put_int(c->remote_id);
1396: packet_put_int(c->local_consumed);
1397: packet_send();
1.70 markus 1398: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1399: c->self, c->local_window,
1400: c->local_consumed);
1401: c->local_window += c->local_consumed;
1402: c->local_consumed = 0;
1.1 deraadt 1403: }
1.41 markus 1404: return 1;
1.1 deraadt 1405: }
1406:
1.127 itojun 1407: static void
1.157 markus 1408: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1409: {
1.137 markus 1410: if (c->delayed)
1411: return;
1.41 markus 1412: channel_handle_rfd(c, readset, writeset);
1413: channel_handle_wfd(c, readset, writeset);
1.157 markus 1414: if (!compat20)
1.137 markus 1415: return;
1.44 markus 1416: channel_handle_efd(c, readset, writeset);
1.93 markus 1417: channel_check_window(c);
1.44 markus 1418: }
1419:
1.127 itojun 1420: static void
1.41 markus 1421: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1422: {
1.41 markus 1423: int len;
1424: /* Send buffered output data to the socket. */
1425: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1426: len = write(c->sock, buffer_ptr(&c->output),
1427: buffer_len(&c->output));
1428: if (len <= 0)
1.158 markus 1429: buffer_clear(&c->output);
1.41 markus 1430: else
1431: buffer_consume(&c->output, len);
1432: }
1433: }
1.25 markus 1434:
1.127 itojun 1435: static void
1.44 markus 1436: channel_handler_init_20(void)
1437: {
1.157 markus 1438: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1439: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1440: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1441: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1442: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1443: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1444: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1445: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1446:
1.157 markus 1447: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1448: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1449: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1450: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1451: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1452: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1453: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1454: }
1455:
1.127 itojun 1456: static void
1.41 markus 1457: channel_handler_init_13(void)
1458: {
1459: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1460: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1461: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1462: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1463: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1464: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1465: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1466: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1467: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1468:
1.157 markus 1469: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1470: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1471: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1472: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1473: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1474: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1475: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1476: }
1.25 markus 1477:
1.127 itojun 1478: static void
1.41 markus 1479: channel_handler_init_15(void)
1480: {
1.157 markus 1481: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1482: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1483: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1484: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1485: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1486: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1487: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1488:
1.41 markus 1489: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1490: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1491: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1492: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1493: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1494: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1495: }
1.27 markus 1496:
1.127 itojun 1497: static void
1.41 markus 1498: channel_handler_init(void)
1499: {
1500: int i;
1.148 deraadt 1501: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1502: channel_pre[i] = NULL;
1503: channel_post[i] = NULL;
1504: }
1.44 markus 1505: if (compat20)
1506: channel_handler_init_20();
1507: else if (compat13)
1.41 markus 1508: channel_handler_init_13();
1509: else
1510: channel_handler_init_15();
1511: }
1.25 markus 1512:
1.140 markus 1513: /* gc dead channels */
1514: static void
1515: channel_garbage_collect(Channel *c)
1516: {
1517: if (c == NULL)
1518: return;
1519: if (c->detach_user != NULL) {
1520: if (!chan_is_dead(c, 0))
1521: return;
1522: debug("channel %d: gc: notify user", c->self);
1523: c->detach_user(c->self, NULL);
1524: /* if we still have a callback */
1525: if (c->detach_user != NULL)
1526: return;
1527: debug("channel %d: gc: user detached", c->self);
1528: }
1529: if (!chan_is_dead(c, 1))
1530: return;
1531: debug("channel %d: garbage collecting", c->self);
1532: channel_free(c);
1533: }
1534:
1.127 itojun 1535: static void
1.41 markus 1536: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1537: {
1538: static int did_init = 0;
1539: int i;
1540: Channel *c;
1.25 markus 1541:
1.41 markus 1542: if (!did_init) {
1543: channel_handler_init();
1544: did_init = 1;
1545: }
1546: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1547: c = channels[i];
1548: if (c == NULL)
1.41 markus 1549: continue;
1.118 markus 1550: if (ftab[c->type] != NULL)
1551: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1552: channel_garbage_collect(c);
1.1 deraadt 1553: }
1554: }
1555:
1.121 markus 1556: /*
1557: * Allocate/update select bitmasks and add any bits relevant to channels in
1558: * select bitmasks.
1559: */
1.49 markus 1560: void
1.100 markus 1561: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1562: int *nallocp, int rekeying)
1.41 markus 1563: {
1.84 markus 1564: int n;
1565: u_int sz;
1566:
1567: n = MAX(*maxfdp, channel_max_fd);
1568:
1569: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1570: /* perhaps check sz < nalloc/2 and shrink? */
1571: if (*readsetp == NULL || sz > *nallocp) {
1572: *readsetp = xrealloc(*readsetp, sz);
1573: *writesetp = xrealloc(*writesetp, sz);
1574: *nallocp = sz;
1.84 markus 1575: }
1.132 markus 1576: *maxfdp = n;
1.84 markus 1577: memset(*readsetp, 0, sz);
1578: memset(*writesetp, 0, sz);
1579:
1.100 markus 1580: if (!rekeying)
1581: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1582: }
1583:
1.121 markus 1584: /*
1585: * After select, perform any appropriate operations for channels which have
1586: * events pending.
1587: */
1.49 markus 1588: void
1.41 markus 1589: channel_after_select(fd_set * readset, fd_set * writeset)
1590: {
1591: channel_handler(channel_post, readset, writeset);
1592: }
1593:
1.121 markus 1594:
1.84 markus 1595: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1596:
1.49 markus 1597: void
1.142 itojun 1598: channel_output_poll(void)
1.1 deraadt 1599: {
1.25 markus 1600: int len, i;
1.41 markus 1601: Channel *c;
1.1 deraadt 1602:
1.25 markus 1603: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1604: c = channels[i];
1605: if (c == NULL)
1606: continue;
1.37 markus 1607:
1.121 markus 1608: /*
1609: * We are only interested in channels that can have buffered
1610: * incoming data.
1611: */
1.37 markus 1612: if (compat13) {
1.41 markus 1613: if (c->type != SSH_CHANNEL_OPEN &&
1614: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1615: continue;
1616: } else {
1.41 markus 1617: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1618: continue;
1619: }
1.46 markus 1620: if (compat20 &&
1621: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1622: /* XXX is this true? */
1.140 markus 1623: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1624: continue;
1625: }
1.25 markus 1626:
1627: /* Get the amount of buffered data for this channel. */
1.93 markus 1628: if ((c->istate == CHAN_INPUT_OPEN ||
1629: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1630: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1631: /*
1632: * Send some data for the other side over the secure
1633: * connection.
1634: */
1.44 markus 1635: if (compat20) {
1636: if (len > c->remote_window)
1637: len = c->remote_window;
1638: if (len > c->remote_maxpacket)
1639: len = c->remote_maxpacket;
1.25 markus 1640: } else {
1.44 markus 1641: if (packet_is_interactive()) {
1642: if (len > 1024)
1643: len = 512;
1644: } else {
1645: /* Keep the packets at reasonable size. */
1646: if (len > packet_get_maxsize()/2)
1647: len = packet_get_maxsize()/2;
1648: }
1.25 markus 1649: }
1.41 markus 1650: if (len > 0) {
1.44 markus 1651: packet_start(compat20 ?
1652: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1653: packet_put_int(c->remote_id);
1654: packet_put_string(buffer_ptr(&c->input), len);
1655: packet_send();
1656: buffer_consume(&c->input, len);
1657: c->remote_window -= len;
1658: }
1659: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1660: if (compat13)
1661: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1662: /*
1663: * input-buffer is empty and read-socket shutdown:
1664: * tell peer, that we will not send more data: send IEOF
1665: */
1.41 markus 1666: chan_ibuf_empty(c);
1.25 markus 1667: }
1.44 markus 1668: /* Send extended data, i.e. stderr */
1669: if (compat20 &&
1670: c->remote_window > 0 &&
1671: (len = buffer_len(&c->extended)) > 0 &&
1672: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1673: debug2("channel %d: rwin %d elen %d euse %d",
1674: c->self, c->remote_window, buffer_len(&c->extended),
1675: c->extended_usage);
1.44 markus 1676: if (len > c->remote_window)
1677: len = c->remote_window;
1678: if (len > c->remote_maxpacket)
1679: len = c->remote_maxpacket;
1680: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1681: packet_put_int(c->remote_id);
1682: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1683: packet_put_string(buffer_ptr(&c->extended), len);
1684: packet_send();
1685: buffer_consume(&c->extended, len);
1686: c->remote_window -= len;
1.93 markus 1687: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1688: }
1.25 markus 1689: }
1.1 deraadt 1690: }
1691:
1.121 markus 1692:
1693: /* -- protocol input */
1.1 deraadt 1694:
1.49 markus 1695: void
1.154 markus 1696: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1697: {
1.37 markus 1698: int id;
1.25 markus 1699: char *data;
1.77 markus 1700: u_int data_len;
1.41 markus 1701: Channel *c;
1.25 markus 1702:
1703: /* Get the channel number and verify it. */
1.37 markus 1704: id = packet_get_int();
1.41 markus 1705: c = channel_lookup(id);
1706: if (c == NULL)
1.37 markus 1707: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1708:
1709: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1710: if (c->type != SSH_CHANNEL_OPEN &&
1711: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1712: return;
1713:
1714: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1715: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1716: return;
1717:
1718: /* Get the data. */
1719: data = packet_get_string(&data_len);
1.41 markus 1720:
1.143 deraadt 1721: if (compat20) {
1.44 markus 1722: if (data_len > c->local_maxpacket) {
1723: log("channel %d: rcvd big packet %d, maxpack %d",
1724: c->self, data_len, c->local_maxpacket);
1725: }
1726: if (data_len > c->local_window) {
1727: log("channel %d: rcvd too much data %d, win %d",
1728: c->self, data_len, c->local_window);
1729: xfree(data);
1730: return;
1731: }
1732: c->local_window -= data_len;
1733: }
1.152 markus 1734: packet_check_eom();
1.41 markus 1735: buffer_append(&c->output, data, data_len);
1.25 markus 1736: xfree(data);
1.1 deraadt 1737: }
1.121 markus 1738:
1.49 markus 1739: void
1.154 markus 1740: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1741: {
1742: int id;
1743: int tcode;
1744: char *data;
1.77 markus 1745: u_int data_len;
1.44 markus 1746: Channel *c;
1747:
1748: /* Get the channel number and verify it. */
1749: id = packet_get_int();
1750: c = channel_lookup(id);
1751:
1752: if (c == NULL)
1753: packet_disconnect("Received extended_data for bad channel %d.", id);
1754: if (c->type != SSH_CHANNEL_OPEN) {
1755: log("channel %d: ext data for non open", id);
1756: return;
1757: }
1758: tcode = packet_get_int();
1759: if (c->efd == -1 ||
1760: c->extended_usage != CHAN_EXTENDED_WRITE ||
1761: tcode != SSH2_EXTENDED_DATA_STDERR) {
1762: log("channel %d: bad ext data", c->self);
1763: return;
1764: }
1765: data = packet_get_string(&data_len);
1.152 markus 1766: packet_check_eom();
1.44 markus 1767: if (data_len > c->local_window) {
1768: log("channel %d: rcvd too much extended_data %d, win %d",
1769: c->self, data_len, c->local_window);
1770: xfree(data);
1771: return;
1772: }
1.70 markus 1773: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1774: c->local_window -= data_len;
1775: buffer_append(&c->extended, data, data_len);
1776: xfree(data);
1777: }
1778:
1.49 markus 1779: void
1.154 markus 1780: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1781: {
1782: int id;
1783: Channel *c;
1784:
1785: id = packet_get_int();
1.152 markus 1786: packet_check_eom();
1.41 markus 1787: c = channel_lookup(id);
1788: if (c == NULL)
1789: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1790: chan_rcvd_ieof(c);
1.133 markus 1791:
1792: /* XXX force input close */
1.156 markus 1793: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1794: debug("channel %d: FORCE input drain", c->self);
1795: c->istate = CHAN_INPUT_WAIT_DRAIN;
1796: }
1797:
1.41 markus 1798: }
1.1 deraadt 1799:
1.49 markus 1800: void
1.154 markus 1801: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1802: {
1.41 markus 1803: int id;
1804: Channel *c;
1.1 deraadt 1805:
1.41 markus 1806: id = packet_get_int();
1.152 markus 1807: packet_check_eom();
1.41 markus 1808: c = channel_lookup(id);
1809: if (c == NULL)
1810: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1811:
1812: /*
1813: * Send a confirmation that we have closed the channel and no more
1814: * data is coming for it.
1815: */
1.25 markus 1816: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1817: packet_put_int(c->remote_id);
1.25 markus 1818: packet_send();
1819:
1.27 markus 1820: /*
1821: * If the channel is in closed state, we have sent a close request,
1822: * and the other side will eventually respond with a confirmation.
1823: * Thus, we cannot free the channel here, because then there would be
1824: * no-one to receive the confirmation. The channel gets freed when
1825: * the confirmation arrives.
1826: */
1.41 markus 1827: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1828: /*
1829: * Not a closed channel - mark it as draining, which will
1830: * cause it to be freed later.
1831: */
1.158 markus 1832: buffer_clear(&c->input);
1.41 markus 1833: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1834: }
1.1 deraadt 1835: }
1836:
1.41 markus 1837: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1838: void
1.154 markus 1839: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1840: {
1841: int id = packet_get_int();
1842: Channel *c = channel_lookup(id);
1.151 markus 1843:
1.152 markus 1844: packet_check_eom();
1.41 markus 1845: if (c == NULL)
1846: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1847: chan_rcvd_oclose(c);
1848: }
1.1 deraadt 1849:
1.49 markus 1850: void
1.154 markus 1851: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1852: {
1.41 markus 1853: int id = packet_get_int();
1854: Channel *c = channel_lookup(id);
1.1 deraadt 1855:
1.152 markus 1856: packet_check_eom();
1.41 markus 1857: if (c == NULL)
1858: packet_disconnect("Received close confirmation for "
1859: "out-of-range channel %d.", id);
1860: if (c->type != SSH_CHANNEL_CLOSED)
1861: packet_disconnect("Received close confirmation for "
1862: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1863: channel_free(c);
1.1 deraadt 1864: }
1865:
1.49 markus 1866: void
1.154 markus 1867: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1868: {
1.41 markus 1869: int id, remote_id;
1870: Channel *c;
1.1 deraadt 1871:
1.41 markus 1872: id = packet_get_int();
1873: c = channel_lookup(id);
1.25 markus 1874:
1.41 markus 1875: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1876: packet_disconnect("Received open confirmation for "
1877: "non-opening channel %d.", id);
1878: remote_id = packet_get_int();
1.27 markus 1879: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1880: c->remote_id = remote_id;
1881: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1882:
1883: if (compat20) {
1884: c->remote_window = packet_get_int();
1885: c->remote_maxpacket = packet_get_int();
1886: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1887: debug2("callback start");
1.44 markus 1888: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1889: debug2("callback done");
1.44 markus 1890: }
1891: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1892: c->remote_window, c->remote_maxpacket);
1893: }
1.152 markus 1894: packet_check_eom();
1.1 deraadt 1895: }
1896:
1.127 itojun 1897: static char *
1.114 markus 1898: reason2txt(int reason)
1899: {
1.143 deraadt 1900: switch (reason) {
1.114 markus 1901: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1902: return "administratively prohibited";
1903: case SSH2_OPEN_CONNECT_FAILED:
1904: return "connect failed";
1905: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1906: return "unknown channel type";
1907: case SSH2_OPEN_RESOURCE_SHORTAGE:
1908: return "resource shortage";
1909: }
1.117 stevesk 1910: return "unknown reason";
1.114 markus 1911: }
1912:
1.49 markus 1913: void
1.154 markus 1914: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1915: {
1.86 markus 1916: int id, reason;
1917: char *msg = NULL, *lang = NULL;
1.41 markus 1918: Channel *c;
1919:
1920: id = packet_get_int();
1921: c = channel_lookup(id);
1.25 markus 1922:
1.41 markus 1923: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1924: packet_disconnect("Received open failure for "
1925: "non-opening channel %d.", id);
1.44 markus 1926: if (compat20) {
1.86 markus 1927: reason = packet_get_int();
1.110 markus 1928: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1929: msg = packet_get_string(NULL);
1930: lang = packet_get_string(NULL);
1931: }
1.114 markus 1932: log("channel %d: open failed: %s%s%s", id,
1933: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1934: if (msg != NULL)
1935: xfree(msg);
1936: if (lang != NULL)
1937: xfree(lang);
1.44 markus 1938: }
1.152 markus 1939: packet_check_eom();
1.25 markus 1940: /* Free the channel. This will also close the socket. */
1.113 markus 1941: channel_free(c);
1.1 deraadt 1942: }
1943:
1.44 markus 1944: void
1.154 markus 1945: channel_input_channel_request(int type, u_int32_t seq, void *ctxt)
1.44 markus 1946: {
1947: int id;
1948: Channel *c;
1949:
1950: id = packet_get_int();
1951: c = channel_lookup(id);
1952:
1953: if (c == NULL ||
1954: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1955: packet_disconnect("Received request for "
1956: "non-open channel %d.", id);
1957: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1958: debug2("callback start");
1.44 markus 1959: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1960: debug2("callback done");
1.44 markus 1961: } else {
1962: char *service = packet_get_string(NULL);
1.94 markus 1963: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1964: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1965: xfree(service);
1966: }
1967: }
1968:
1.121 markus 1969: void
1.154 markus 1970: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1971: {
1972: Channel *c;
1973: int id, adjust;
1974:
1975: if (!compat20)
1976: return;
1977:
1978: /* Get the channel number and verify it. */
1979: id = packet_get_int();
1980: c = channel_lookup(id);
1.1 deraadt 1981:
1.121 markus 1982: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1983: log("Received window adjust for "
1984: "non-open channel %d.", id);
1985: return;
1986: }
1987: adjust = packet_get_int();
1.152 markus 1988: packet_check_eom();
1.121 markus 1989: debug2("channel %d: rcvd adjust %d", id, adjust);
1990: c->remote_window += adjust;
1991: }
1.1 deraadt 1992:
1.121 markus 1993: void
1.154 markus 1994: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1995: {
1.121 markus 1996: Channel *c = NULL;
1997: u_short host_port;
1998: char *host, *originator_string;
1999: int remote_id, sock = -1;
2000:
2001: remote_id = packet_get_int();
2002: host = packet_get_string(NULL);
2003: host_port = packet_get_int();
1.25 markus 2004:
1.121 markus 2005: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2006: originator_string = packet_get_string(NULL);
2007: } else {
2008: originator_string = xstrdup("unknown (remote did not supply name)");
2009: }
1.152 markus 2010: packet_check_eom();
1.121 markus 2011: sock = channel_connect_to(host, host_port);
2012: if (sock != -1) {
2013: c = channel_new("connected socket",
2014: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2015: originator_string, 1);
2016: if (c == NULL) {
2017: error("channel_input_port_open: channel_new failed");
2018: close(sock);
2019: } else {
2020: c->remote_id = remote_id;
1.25 markus 2021: }
2022: }
1.121 markus 2023: if (c == NULL) {
2024: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2025: packet_put_int(remote_id);
2026: packet_send();
2027: }
2028: xfree(host);
1.1 deraadt 2029: }
2030:
1.121 markus 2031:
2032: /* -- tcp forwarding */
1.135 markus 2033:
2034: void
2035: channel_set_af(int af)
2036: {
2037: IPv4or6 = af;
2038: }
1.121 markus 2039:
1.160 ! markus 2040: static int
! 2041: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
! 2042: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2043: {
1.113 markus 2044: Channel *c;
1.160 ! markus 2045: int success, sock, on = 1;
1.35 markus 2046: struct addrinfo hints, *ai, *aitop;
1.160 ! markus 2047: const char *host;
1.35 markus 2048: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2049: struct linger linger;
1.25 markus 2050:
1.87 markus 2051: success = 0;
1.160 ! markus 2052: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
! 2053: listen_addr : host_to_connect;
1.87 markus 2054:
1.160 ! markus 2055: if (host == NULL) {
! 2056: error("No forward host name.");
! 2057: return success;
1.73 markus 2058: }
1.113 markus 2059: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2060: error("Forward host name too long.");
2061: return success;
2062: }
1.25 markus 2063:
1.28 markus 2064: /*
1.35 markus 2065: * getaddrinfo returns a loopback address if the hostname is
2066: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2067: */
1.35 markus 2068: memset(&hints, 0, sizeof(hints));
2069: hints.ai_family = IPv4or6;
2070: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2071: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2072: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2073: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2074: packet_disconnect("getaddrinfo: fatal error");
2075:
2076: for (ai = aitop; ai; ai = ai->ai_next) {
2077: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2078: continue;
2079: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2080: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 ! markus 2081: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2082: continue;
2083: }
2084: /* Create a port to listen for the host. */
2085: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2086: if (sock < 0) {
2087: /* this is no error since kernel may not support ipv6 */
2088: verbose("socket: %.100s", strerror(errno));
2089: continue;
2090: }
2091: /*
2092: * Set socket options. We would like the socket to disappear
2093: * as soon as it has been closed for whatever reason.
2094: */
2095: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2096: linger.l_onoff = 1;
2097: linger.l_linger = 5;
2098: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2099: debug("Local forwarding listening on %s port %s.", ntop, strport);
2100:
2101: /* Bind the socket to the address. */
2102: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2103: /* address can be in use ipv6 address is already bound */
2104: verbose("bind: %.100s", strerror(errno));
2105: close(sock);
2106: continue;
2107: }
2108: /* Start listening for connections on the socket. */
2109: if (listen(sock, 5) < 0) {
2110: error("listen: %.100s", strerror(errno));
2111: close(sock);
2112: continue;
2113: }
2114: /* Allocate a channel number for the socket. */
1.121 markus 2115: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2116: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2117: 0, xstrdup("port listener"), 1);
1.113 markus 2118: if (c == NULL) {
1.160 ! markus 2119: error("channel_setup_fwd_listener: channel_new failed");
1.113 markus 2120: close(sock);
2121: continue;
2122: }
2123: strlcpy(c->path, host, sizeof(c->path));
2124: c->host_port = port_to_connect;
2125: c->listening_port = listen_port;
1.35 markus 2126: success = 1;
2127: }
2128: if (success == 0)
1.160 ! markus 2129: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2130: listen_port);
1.35 markus 2131: freeaddrinfo(aitop);
1.87 markus 2132: return success;
1.25 markus 2133: }
1.1 deraadt 2134:
1.160 ! markus 2135: /* protocol local port fwd, used by ssh (and sshd in v1) */
! 2136: int
! 2137: channel_setup_local_fwd_listener(u_short listen_port,
! 2138: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
! 2139: {
! 2140: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
! 2141: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
! 2142: }
! 2143:
! 2144: /* protocol v2 remote port fwd, used by sshd */
! 2145: int
! 2146: channel_setup_remote_fwd_listener(const char *listen_address,
! 2147: u_short listen_port, int gateway_ports)
! 2148: {
! 2149: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
! 2150: listen_address, listen_port, NULL, 0, gateway_ports);
! 2151: }
! 2152:
1.27 markus 2153: /*
2154: * Initiate forwarding of connections to port "port" on remote host through
2155: * the secure channel to host:port from local side.
2156: */
1.1 deraadt 2157:
1.49 markus 2158: void
1.73 markus 2159: channel_request_remote_forwarding(u_short listen_port,
2160: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2161: {
1.153 markus 2162: int type, success = 0;
1.73 markus 2163:
1.25 markus 2164: /* Record locally that connection to this host/port is permitted. */
2165: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2166: fatal("channel_request_remote_forwarding: too many forwards");
2167:
2168: /* Send the forward request to the remote side. */
1.44 markus 2169: if (compat20) {
2170: const char *address_to_bind = "0.0.0.0";
2171: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2172: packet_put_cstring("tcpip-forward");
2173: packet_put_char(0); /* boolean: want reply */
2174: packet_put_cstring(address_to_bind);
2175: packet_put_int(listen_port);
1.73 markus 2176: packet_send();
2177: packet_write_wait();
2178: /* Assume that server accepts the request */
2179: success = 1;
1.44 markus 2180: } else {
2181: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2182: packet_put_int(listen_port);
2183: packet_put_cstring(host_to_connect);
1.44 markus 2184: packet_put_int(port_to_connect);
2185: packet_send();
2186: packet_write_wait();
1.73 markus 2187:
2188: /* Wait for response from the remote side. */
1.153 markus 2189: type = packet_read();
1.73 markus 2190: switch (type) {
2191: case SSH_SMSG_SUCCESS:
2192: success = 1;
2193: break;
2194: case SSH_SMSG_FAILURE:
2195: log("Warning: Server denied remote port forwarding.");
2196: break;
2197: default:
2198: /* Unknown packet */
2199: packet_disconnect("Protocol error for port forward request:"
2200: "received packet type %d.", type);
2201: }
2202: }
2203: if (success) {
2204: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2205: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2206: permitted_opens[num_permitted_opens].listen_port = listen_port;
2207: num_permitted_opens++;
1.44 markus 2208: }
1.1 deraadt 2209: }
2210:
1.27 markus 2211: /*
2212: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2213: * listening for the port, and sends back a success reply (or disconnect
2214: * message if there was an error). This never returns if there was an error.
2215: */
1.1 deraadt 2216:
1.49 markus 2217: void
1.56 markus 2218: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2219: {
1.31 markus 2220: u_short port, host_port;
1.25 markus 2221: char *hostname;
1.1 deraadt 2222:
1.25 markus 2223: /* Get arguments from the packet. */
2224: port = packet_get_int();
2225: hostname = packet_get_string(NULL);
2226: host_port = packet_get_int();
2227:
1.27 markus 2228: /*
2229: * Check that an unprivileged user is not trying to forward a
2230: * privileged port.
2231: */
1.25 markus 2232: if (port < IPPORT_RESERVED && !is_root)
2233: packet_disconnect("Requested forwarding of port %d but user is not root.",
2234: port);
1.73 markus 2235: /* Initiate forwarding */
1.160 ! markus 2236: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2237:
2238: /* Free the argument string. */
2239: xfree(hostname);
1.1 deraadt 2240: }
2241:
1.99 markus 2242: /*
2243: * Permits opening to any host/port if permitted_opens[] is empty. This is
2244: * usually called by the server, because the user could connect to any port
2245: * anyway, and the server has no way to know but to trust the client anyway.
2246: */
2247: void
1.142 itojun 2248: channel_permit_all_opens(void)
1.99 markus 2249: {
2250: if (num_permitted_opens == 0)
2251: all_opens_permitted = 1;
2252: }
2253:
1.101 markus 2254: void
1.99 markus 2255: channel_add_permitted_opens(char *host, int port)
2256: {
2257: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2258: fatal("channel_request_remote_forwarding: too many forwards");
2259: debug("allow port forwarding to host %s port %d", host, port);
2260:
2261: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2262: permitted_opens[num_permitted_opens].port_to_connect = port;
2263: num_permitted_opens++;
2264:
2265: all_opens_permitted = 0;
2266: }
2267:
1.101 markus 2268: void
1.99 markus 2269: channel_clear_permitted_opens(void)
2270: {
2271: int i;
2272:
2273: for (i = 0; i < num_permitted_opens; i++)
2274: xfree(permitted_opens[i].host_to_connect);
2275: num_permitted_opens = 0;
2276:
2277: }
2278:
2279:
2280: /* return socket to remote host, port */
1.127 itojun 2281: static int
1.99 markus 2282: connect_to(const char *host, u_short port)
1.41 markus 2283: {
2284: struct addrinfo hints, *ai, *aitop;
2285: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2286: int gaierr;
2287: int sock = -1;
2288:
2289: memset(&hints, 0, sizeof(hints));
2290: hints.ai_family = IPv4or6;
2291: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2292: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2293: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2294: error("connect_to %.100s: unknown host (%s)", host,
2295: gai_strerror(gaierr));
1.41 markus 2296: return -1;
2297: }
2298: for (ai = aitop; ai; ai = ai->ai_next) {
2299: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2300: continue;
2301: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2302: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2303: error("connect_to: getnameinfo failed");
1.41 markus 2304: continue;
2305: }
2306: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2307: if (sock < 0) {
2308: error("socket: %.100s", strerror(errno));
2309: continue;
2310: }
1.80 markus 2311: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2312: fatal("connect_to: F_SETFL: %s", strerror(errno));
2313: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2314: errno != EINPROGRESS) {
1.99 markus 2315: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2316: strerror(errno));
2317: close(sock);
1.89 stevesk 2318: continue; /* fail -- try next */
1.41 markus 2319: }
2320: break; /* success */
2321:
2322: }
2323: freeaddrinfo(aitop);
2324: if (!ai) {
1.99 markus 2325: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2326: return -1;
2327: }
2328: /* success */
2329: return sock;
2330: }
1.99 markus 2331:
1.73 markus 2332: int
1.130 stevesk 2333: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2334: {
2335: int i;
1.99 markus 2336:
1.73 markus 2337: for (i = 0; i < num_permitted_opens; i++)
2338: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2339: return connect_to(
1.73 markus 2340: permitted_opens[i].host_to_connect,
2341: permitted_opens[i].port_to_connect);
1.74 markus 2342: error("WARNING: Server requests forwarding for unknown listen_port %d",
2343: listen_port);
1.73 markus 2344: return -1;
2345: }
2346:
1.99 markus 2347: /* Check if connecting to that port is permitted and connect. */
2348: int
2349: channel_connect_to(const char *host, u_short port)
2350: {
2351: int i, permit;
2352:
2353: permit = all_opens_permitted;
2354: if (!permit) {
2355: for (i = 0; i < num_permitted_opens; i++)
2356: if (permitted_opens[i].port_to_connect == port &&
2357: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2358: permit = 1;
2359:
2360: }
2361: if (!permit) {
2362: log("Received request to connect to host %.100s port %d, "
2363: "but the request was denied.", host, port);
2364: return -1;
2365: }
2366: return connect_to(host, port);
2367: }
2368:
1.121 markus 2369: /* -- X11 forwarding */
1.1 deraadt 2370:
1.27 markus 2371: /*
2372: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2373: * Returns a suitable display number for the DISPLAY variable, or -1 if
2374: * an error occurs.
1.27 markus 2375: */
1.141 stevesk 2376: int
1.149 markus 2377: x11_create_display_inet(int x11_display_offset, int gateway_ports,
2378: int single_connection)
1.1 deraadt 2379: {
1.149 markus 2380: Channel *nc = NULL;
1.31 markus 2381: int display_number, sock;
2382: u_short port;
1.35 markus 2383: struct addrinfo hints, *ai, *aitop;
2384: char strport[NI_MAXSERV];
2385: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2386:
1.33 markus 2387: for (display_number = x11_display_offset;
1.148 deraadt 2388: display_number < MAX_DISPLAYS;
2389: display_number++) {
1.25 markus 2390: port = 6000 + display_number;
1.35 markus 2391: memset(&hints, 0, sizeof(hints));
2392: hints.ai_family = IPv4or6;
1.141 stevesk 2393: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1.35 markus 2394: hints.ai_socktype = SOCK_STREAM;
2395: snprintf(strport, sizeof strport, "%d", port);
2396: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2397: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2398: return -1;
1.25 markus 2399: }
1.35 markus 2400: for (ai = aitop; ai; ai = ai->ai_next) {
2401: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2402: continue;
2403: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2404: if (sock < 0) {
2405: error("socket: %.100s", strerror(errno));
1.141 stevesk 2406: return -1;
1.35 markus 2407: }
2408: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2409: debug("bind port %d: %.100s", port, strerror(errno));
2410: close(sock);
2411: for (n = 0; n < num_socks; n++) {
2412: close(socks[n]);
2413: }
2414: num_socks = 0;
2415: break;
2416: }
2417: socks[num_socks++] = sock;
2418: if (num_socks == NUM_SOCKS)
2419: break;
1.25 markus 2420: }
1.83 stevesk 2421: freeaddrinfo(aitop);
1.35 markus 2422: if (num_socks > 0)
2423: break;
1.25 markus 2424: }
2425: if (display_number >= MAX_DISPLAYS) {
2426: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2427: return -1;
1.25 markus 2428: }
2429: /* Start listening for connections on the socket. */
1.35 markus 2430: for (n = 0; n < num_socks; n++) {
2431: sock = socks[n];
2432: if (listen(sock, 5) < 0) {
2433: error("listen: %.100s", strerror(errno));
2434: close(sock);
1.141 stevesk 2435: return -1;
1.35 markus 2436: }
1.25 markus 2437: }
1.35 markus 2438:
2439: /* Allocate a channel for each socket. */
2440: for (n = 0; n < num_socks; n++) {
2441: sock = socks[n];
1.149 markus 2442: nc = channel_new("x11 listener",
1.51 markus 2443: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2444: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2445: 0, xstrdup("X11 inet listener"), 1);
1.149 markus 2446: if (nc != NULL)
2447: nc->single_connection = single_connection;
1.35 markus 2448: }
1.1 deraadt 2449:
1.141 stevesk 2450: /* Return the display number for the DISPLAY environment variable. */
2451: return display_number;
1.1 deraadt 2452: }
2453:
1.127 itojun 2454: static int
1.77 markus 2455: connect_local_xsocket(u_int dnr)
1.1 deraadt 2456: {
1.25 markus 2457: int sock;
2458: struct sockaddr_un addr;
2459:
1.147 stevesk 2460: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2461: if (sock < 0)
2462: error("socket: %.100s", strerror(errno));
2463: memset(&addr, 0, sizeof(addr));
2464: addr.sun_family = AF_UNIX;
2465: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2466: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2467: return sock;
2468: close(sock);
1.25 markus 2469: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2470: return -1;
1.1 deraadt 2471: }
2472:
1.51 markus 2473: int
2474: x11_connect_display(void)
1.1 deraadt 2475: {
1.146 stevesk 2476: int display_number, sock = 0, on = 1;
1.25 markus 2477: const char *display;
1.51 markus 2478: char buf[1024], *cp;
1.35 markus 2479: struct addrinfo hints, *ai, *aitop;
2480: char strport[NI_MAXSERV];
2481: int gaierr;
1.25 markus 2482:
2483: /* Try to open a socket for the local X server. */
2484: display = getenv("DISPLAY");
2485: if (!display) {
2486: error("DISPLAY not set.");
1.51 markus 2487: return -1;
1.25 markus 2488: }
1.27 markus 2489: /*
2490: * Now we decode the value of the DISPLAY variable and make a
2491: * connection to the real X server.
2492: */
2493:
2494: /*
2495: * Check if it is a unix domain socket. Unix domain displays are in
2496: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2497: */
1.25 markus 2498: if (strncmp(display, "unix:", 5) == 0 ||
2499: display[0] == ':') {
2500: /* Connect to the unix domain socket. */
2501: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2502: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2503: display);
1.51 markus 2504: return -1;
1.25 markus 2505: }
2506: /* Create a socket. */
2507: sock = connect_local_xsocket(display_number);
2508: if (sock < 0)
1.51 markus 2509: return -1;
1.25 markus 2510:
2511: /* OK, we now have a connection to the display. */
1.51 markus 2512: return sock;
1.25 markus 2513: }
1.27 markus 2514: /*
2515: * Connect to an inet socket. The DISPLAY value is supposedly
2516: * hostname:d[.s], where hostname may also be numeric IP address.
2517: */
1.145 stevesk 2518: strlcpy(buf, display, sizeof(buf));
1.25 markus 2519: cp = strchr(buf, ':');
2520: if (!cp) {
2521: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2522: return -1;
1.25 markus 2523: }
2524: *cp = 0;
1.27 markus 2525: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2526: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2527: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2528: display);
1.51 markus 2529: return -1;
1.25 markus 2530: }
1.35 markus 2531:
2532: /* Look up the host address */
2533: memset(&hints, 0, sizeof(hints));
2534: hints.ai_family = IPv4or6;
2535: hints.ai_socktype = SOCK_STREAM;
2536: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2537: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2538: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2539: return -1;
1.25 markus 2540: }
1.35 markus 2541: for (ai = aitop; ai; ai = ai->ai_next) {
2542: /* Create a socket. */
2543: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2544: if (sock < 0) {
2545: debug("socket: %.100s", strerror(errno));
1.41 markus 2546: continue;
2547: }
2548: /* Connect it to the display. */
2549: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2550: debug("connect %.100s port %d: %.100s", buf,
2551: 6000 + display_number, strerror(errno));
2552: close(sock);
2553: continue;
2554: }
2555: /* Success */
2556: break;
1.35 markus 2557: }
2558: freeaddrinfo(aitop);
2559: if (!ai) {
1.49 markus 2560: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2561: strerror(errno));
1.51 markus 2562: return -1;
1.25 markus 2563: }
1.146 stevesk 2564: if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on) == -1)
2565: error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
1.51 markus 2566: return sock;
2567: }
2568:
2569: /*
2570: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2571: * the remote channel number. We should do whatever we want, and respond
2572: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2573: */
2574:
2575: void
1.154 markus 2576: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2577: {
1.113 markus 2578: Channel *c = NULL;
2579: int remote_id, sock = 0;
1.51 markus 2580: char *remote_host;
1.25 markus 2581:
1.113 markus 2582: debug("Received X11 open request.");
1.51 markus 2583:
1.113 markus 2584: remote_id = packet_get_int();
1.121 markus 2585:
2586: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2587: remote_host = packet_get_string(NULL);
1.51 markus 2588: } else {
2589: remote_host = xstrdup("unknown (remote did not supply name)");
2590: }
1.152 markus 2591: packet_check_eom();
1.25 markus 2592:
1.51 markus 2593: /* Obtain a connection to the real X display. */
2594: sock = x11_connect_display();
1.113 markus 2595: if (sock != -1) {
2596: /* Allocate a channel for this connection. */
2597: c = channel_new("connected x11 socket",
2598: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2599: remote_host, 1);
2600: if (c == NULL) {
2601: error("x11_input_open: channel_new failed");
2602: close(sock);
2603: } else {
2604: c->remote_id = remote_id;
1.133 markus 2605: c->force_drain = 1;
1.113 markus 2606: }
2607: }
2608: if (c == NULL) {
1.51 markus 2609: /* Send refusal to the remote host. */
2610: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2611: packet_put_int(remote_id);
1.51 markus 2612: } else {
2613: /* Send a confirmation to the remote host. */
2614: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2615: packet_put_int(remote_id);
2616: packet_put_int(c->self);
1.51 markus 2617: }
1.113 markus 2618: packet_send();
1.72 markus 2619: }
2620:
2621: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2622: void
1.154 markus 2623: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2624: {
2625: int rchan = packet_get_int();
1.143 deraadt 2626: switch (type) {
1.72 markus 2627: case SSH_SMSG_AGENT_OPEN:
2628: error("Warning: ssh server tried agent forwarding.");
2629: break;
2630: case SSH_SMSG_X11_OPEN:
2631: error("Warning: ssh server tried X11 forwarding.");
2632: break;
2633: default:
1.154 markus 2634: error("deny_input_open: type %d", type);
1.72 markus 2635: break;
2636: }
2637: error("Warning: this is probably a break in attempt by a malicious server.");
2638: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2639: packet_put_int(rchan);
2640: packet_send();
1.1 deraadt 2641: }
2642:
1.27 markus 2643: /*
2644: * Requests forwarding of X11 connections, generates fake authentication
2645: * data, and enables authentication spoofing.
1.121 markus 2646: * This should be called in the client only.
1.27 markus 2647: */
1.49 markus 2648: void
1.51 markus 2649: x11_request_forwarding_with_spoofing(int client_session_id,
2650: const char *proto, const char *data)
1.1 deraadt 2651: {
1.77 markus 2652: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2653: u_int i, value, len;
1.25 markus 2654: char *new_data;
2655: int screen_number;
2656: const char *cp;
2657: u_int32_t rand = 0;
2658:
2659: cp = getenv("DISPLAY");
2660: if (cp)
2661: cp = strchr(cp, ':');
2662: if (cp)
2663: cp = strchr(cp, '.');
2664: if (cp)
2665: screen_number = atoi(cp + 1);
2666: else
2667: screen_number = 0;
2668:
2669: /* Save protocol name. */
2670: x11_saved_proto = xstrdup(proto);
2671:
1.27 markus 2672: /*
2673: * Extract real authentication data and generate fake data of the
2674: * same length.
2675: */
1.25 markus 2676: x11_saved_data = xmalloc(data_len);
2677: x11_fake_data = xmalloc(data_len);
2678: for (i = 0; i < data_len; i++) {
2679: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2680: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2681: if (i % 4 == 0)
2682: rand = arc4random();
2683: x11_saved_data[i] = value;
2684: x11_fake_data[i] = rand & 0xff;
2685: rand >>= 8;
2686: }
2687: x11_saved_data_len = data_len;
2688: x11_fake_data_len = data_len;
2689:
2690: /* Convert the fake data into hex. */
1.90 markus 2691: len = 2 * data_len + 1;
2692: new_data = xmalloc(len);
1.25 markus 2693: for (i = 0; i < data_len; i++)
1.90 markus 2694: snprintf(new_data + 2 * i, len - 2 * i,
2695: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2696:
2697: /* Send the request packet. */
1.51 markus 2698: if (compat20) {
2699: channel_request_start(client_session_id, "x11-req", 0);
2700: packet_put_char(0); /* XXX bool single connection */
2701: } else {
2702: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2703: }
2704: packet_put_cstring(proto);
2705: packet_put_cstring(new_data);
1.25 markus 2706: packet_put_int(screen_number);
2707: packet_send();
2708: packet_write_wait();
2709: xfree(new_data);
1.1 deraadt 2710: }
2711:
1.121 markus 2712:
2713: /* -- agent forwarding */
2714:
1.1 deraadt 2715: /* Sends a message to the server to request authentication fd forwarding. */
2716:
1.49 markus 2717: void
1.142 itojun 2718: auth_request_forwarding(void)
1.1 deraadt 2719: {
1.25 markus 2720: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2721: packet_send();
2722: packet_write_wait();
1.1 deraadt 2723: }
2724:
1.27 markus 2725: /*
2726: * Returns the name of the forwarded authentication socket. Returns NULL if
2727: * there is no forwarded authentication socket. The returned value points to
2728: * a static buffer.
2729: */
1.1 deraadt 2730:
1.25 markus 2731: char *
1.142 itojun 2732: auth_get_socket_name(void)
1.1 deraadt 2733: {
1.121 markus 2734: return auth_sock_name;
1.1 deraadt 2735: }
2736:
1.12 markus 2737: /* removes the agent forwarding socket */
2738:
1.49 markus 2739: void
1.123 markus 2740: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2741: {
1.123 markus 2742: struct passwd *pw = _pw;
2743:
1.122 markus 2744: if (auth_sock_name) {
1.123 markus 2745: temporarily_use_uid(pw);
1.122 markus 2746: unlink(auth_sock_name);
2747: rmdir(auth_sock_dir);
2748: auth_sock_name = NULL;
1.123 markus 2749: restore_uid();
1.122 markus 2750: }
1.12 markus 2751: }
2752:
1.27 markus 2753: /*
1.59 markus 2754: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2755: * This starts forwarding authentication requests.
2756: */
1.1 deraadt 2757:
1.59 markus 2758: int
1.25 markus 2759: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2760: {
1.113 markus 2761: Channel *nc;
2762: int sock;
1.25 markus 2763: struct sockaddr_un sunaddr;
2764:
1.121 markus 2765: if (auth_get_socket_name() != NULL) {
2766: error("authentication forwarding requested twice.");
2767: return 0;
2768: }
1.25 markus 2769:
2770: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2771: temporarily_use_uid(pw);
1.25 markus 2772:
2773: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2774: auth_sock_name = xmalloc(MAXPATHLEN);
2775: auth_sock_dir = xmalloc(MAXPATHLEN);
2776: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2777:
2778: /* Create private directory for socket */
1.121 markus 2779: if (mkdtemp(auth_sock_dir) == NULL) {
2780: packet_send_debug("Agent forwarding disabled: "
2781: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2782: restore_uid();
1.121 markus 2783: xfree(auth_sock_name);
2784: xfree(auth_sock_dir);
2785: auth_sock_name = NULL;
2786: auth_sock_dir = NULL;
1.59 markus 2787: return 0;
2788: }
1.121 markus 2789: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2790: auth_sock_dir, (int) getpid());
1.25 markus 2791:
1.122 markus 2792: /* delete agent socket on fatal() */
1.123 markus 2793: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2794:
1.25 markus 2795: /* Create the socket. */
2796: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2797: if (sock < 0)
2798: packet_disconnect("socket: %.100s", strerror(errno));
2799:
2800: /* Bind it to the name. */
2801: memset(&sunaddr, 0, sizeof(sunaddr));
2802: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2803: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2804:
2805: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2806: packet_disconnect("bind: %.100s", strerror(errno));
2807:
2808: /* Restore the privileged uid. */
2809: restore_uid();
2810:
2811: /* Start listening on the socket. */
2812: if (listen(sock, 5) < 0)
2813: packet_disconnect("listen: %.100s", strerror(errno));
2814:
2815: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2816: nc = channel_new("auth socket",
1.73 markus 2817: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2818: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2819: 0, xstrdup("auth socket"), 1);
1.113 markus 2820: if (nc == NULL) {
2821: error("auth_input_request_forwarding: channel_new failed");
1.123 markus 2822: auth_sock_cleanup_proc(pw);
1.124 markus 2823: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
1.113 markus 2824: close(sock);
2825: return 0;
2826: }
1.121 markus 2827: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2828: return 1;
1.1 deraadt 2829: }
2830:
2831: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2832:
1.49 markus 2833: void
1.154 markus 2834: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2835: {
1.113 markus 2836: Channel *c = NULL;
2837: int remote_id, sock;
1.121 markus 2838: char *name;
1.41 markus 2839:
1.25 markus 2840: /* Read the remote channel number from the message. */
1.113 markus 2841: remote_id = packet_get_int();
1.152 markus 2842: packet_check_eom();
1.25 markus 2843:
1.27 markus 2844: /*
2845: * Get a connection to the local authentication agent (this may again
2846: * get forwarded).
2847: */
1.25 markus 2848: sock = ssh_get_authentication_socket();
2849:
1.27 markus 2850: /*
2851: * If we could not connect the agent, send an error message back to
2852: * the server. This should never happen unless the agent dies,
2853: * because authentication forwarding is only enabled if we have an
2854: * agent.
2855: */
1.113 markus 2856: if (sock >= 0) {
1.121 markus 2857: name = xstrdup("authentication agent connection");
2858: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2859: -1, 0, 0, 0, name, 1);
1.113 markus 2860: if (c == NULL) {
2861: error("auth_input_open_request: channel_new failed");
1.121 markus 2862: xfree(name);
1.113 markus 2863: close(sock);
2864: } else {
2865: c->remote_id = remote_id;
1.133 markus 2866: c->force_drain = 1;
1.113 markus 2867: }
2868: }
2869: if (c == NULL) {
1.25 markus 2870: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2871: packet_put_int(remote_id);
2872: } else {
2873: /* Send a confirmation to the remote host. */
2874: debug("Forwarding authentication connection.");
2875: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2876: packet_put_int(remote_id);
2877: packet_put_int(c->self);
1.25 markus 2878: }
2879: packet_send();
1.1 deraadt 2880: }
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