Annotation of src/usr.bin/ssh/channels.c, Revision 1.156
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"
1.156 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.155 2001/12/29 21:56:01 stevesk 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) {
1.44 markus 220: chan_init();
1.25 markus 221: channels_alloc = 10;
1.113 markus 222: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 223: for (i = 0; i < channels_alloc; i++)
1.113 markus 224: channels[i] = NULL;
1.126 markus 225: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 226: }
227: /* Try to find a free slot where to put the new channel. */
228: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 229: if (channels[i] == NULL) {
1.25 markus 230: /* Found a free slot. */
231: found = i;
232: break;
233: }
234: if (found == -1) {
1.27 markus 235: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 236: found = channels_alloc;
237: channels_alloc += 10;
1.70 markus 238: debug2("channel: expanding %d", channels_alloc);
1.113 markus 239: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 240: for (i = found; i < channels_alloc; i++)
1.113 markus 241: channels[i] = NULL;
1.25 markus 242: }
1.113 markus 243: /* Initialize and return new channel. */
244: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 245: memset(c, 0, sizeof(Channel));
1.25 markus 246: buffer_init(&c->input);
247: buffer_init(&c->output);
1.41 markus 248: buffer_init(&c->extended);
1.25 markus 249: chan_init_iostates(c);
1.71 markus 250: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 251: c->self = found;
252: c->type = type;
1.41 markus 253: c->ctype = ctype;
1.51 markus 254: c->local_window = window;
255: c->local_window_max = window;
256: c->local_consumed = 0;
257: c->local_maxpacket = maxpack;
1.25 markus 258: c->remote_id = -1;
259: c->remote_name = remote_name;
1.41 markus 260: c->remote_window = 0;
261: c->remote_maxpacket = 0;
262: c->cb_fn = NULL;
263: c->cb_arg = NULL;
264: c->cb_event = 0;
1.133 markus 265: c->force_drain = 0;
1.149 markus 266: c->single_connection = 0;
1.131 markus 267: c->detach_user = NULL;
1.65 markus 268: c->input_filter = NULL;
1.25 markus 269: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 270: return c;
1.1 deraadt 271: }
1.52 markus 272:
1.132 markus 273: static int
274: channel_find_maxfd(void)
275: {
276: int i, max = 0;
277: Channel *c;
278:
279: for (i = 0; i < channels_alloc; i++) {
280: c = channels[i];
281: if (c != NULL) {
282: max = MAX(max, c->rfd);
283: max = MAX(max, c->wfd);
284: max = MAX(max, c->efd);
285: }
286: }
287: return max;
288: }
289:
290: int
291: channel_close_fd(int *fdp)
292: {
293: int ret = 0, fd = *fdp;
294:
295: if (fd != -1) {
296: ret = close(fd);
297: *fdp = -1;
298: if (fd == channel_max_fd)
299: channel_max_fd = channel_find_maxfd();
300: }
301: return ret;
302: }
303:
1.52 markus 304: /* Close all channel fd/socket. */
305:
1.127 itojun 306: static void
1.52 markus 307: channel_close_fds(Channel *c)
308: {
1.118 markus 309: debug3("channel_close_fds: channel %d: r %d w %d e %d",
310: c->self, c->rfd, c->wfd, c->efd);
311:
1.132 markus 312: channel_close_fd(&c->sock);
313: channel_close_fd(&c->rfd);
314: channel_close_fd(&c->wfd);
315: channel_close_fd(&c->efd);
1.121 markus 316: }
317:
318: /* Free the channel and close its fd/socket. */
319:
320: void
321: channel_free(Channel *c)
322: {
323: char *s;
324: int i, n;
325:
326: for (n = 0, i = 0; i < channels_alloc; i++)
327: if (channels[i])
328: n++;
329: debug("channel_free: channel %d: %s, nchannels %d", c->self,
330: c->remote_name ? c->remote_name : "???", n);
331:
332: s = channel_open_message();
333: debug3("channel_free: status: %s", s);
334: xfree(s);
335:
336: if (c->sock != -1)
337: shutdown(c->sock, SHUT_RDWR);
338: channel_close_fds(c);
339: buffer_free(&c->input);
340: buffer_free(&c->output);
341: buffer_free(&c->extended);
342: if (c->remote_name) {
343: xfree(c->remote_name);
344: c->remote_name = NULL;
345: }
346: channels[c->self] = NULL;
347: xfree(c);
348: }
349:
350: void
1.126 markus 351: channel_free_all(void)
1.121 markus 352: {
353: int i;
354:
1.126 markus 355: for (i = 0; i < channels_alloc; i++)
356: if (channels[i] != NULL)
357: channel_free(channels[i]);
1.131 markus 358: }
359:
1.121 markus 360: /*
361: * Closes the sockets/fds of all channels. This is used to close extra file
362: * descriptors after a fork.
363: */
364:
365: void
1.142 itojun 366: channel_close_all(void)
1.121 markus 367: {
368: int i;
369:
370: for (i = 0; i < channels_alloc; i++)
371: if (channels[i] != NULL)
372: channel_close_fds(channels[i]);
373: }
374:
375: /*
1.131 markus 376: * Stop listening to channels.
377: */
378:
379: void
380: channel_stop_listening(void)
381: {
382: int i;
383: Channel *c;
384:
385: for (i = 0; i < channels_alloc; i++) {
386: c = channels[i];
387: if (c != NULL) {
388: switch (c->type) {
389: case SSH_CHANNEL_AUTH_SOCKET:
390: case SSH_CHANNEL_PORT_LISTENER:
391: case SSH_CHANNEL_RPORT_LISTENER:
392: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 393: channel_close_fd(&c->sock);
1.131 markus 394: channel_free(c);
395: break;
396: }
397: }
398: }
399: }
400:
401: /*
1.121 markus 402: * Returns true if no channel has too much buffered data, and false if one or
403: * more channel is overfull.
404: */
405:
406: int
1.142 itojun 407: channel_not_very_much_buffered_data(void)
1.121 markus 408: {
409: u_int i;
410: Channel *c;
411:
412: for (i = 0; i < channels_alloc; i++) {
413: c = channels[i];
414: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 415: #if 0
416: if (!compat20 &&
417: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 418: debug("channel %d: big input buffer %d",
419: c->self, buffer_len(&c->input));
420: return 0;
421: }
1.136 markus 422: #endif
1.121 markus 423: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 424: debug("channel %d: big output buffer %d > %d",
425: c->self, buffer_len(&c->output),
426: packet_get_maxsize());
1.121 markus 427: return 0;
428: }
429: }
430: }
431: return 1;
432: }
433:
434: /* Returns true if any channel is still open. */
435:
436: int
1.142 itojun 437: channel_still_open(void)
1.121 markus 438: {
439: int i;
440: Channel *c;
441:
442: for (i = 0; i < channels_alloc; i++) {
443: c = channels[i];
444: if (c == NULL)
445: continue;
446: switch (c->type) {
447: case SSH_CHANNEL_X11_LISTENER:
448: case SSH_CHANNEL_PORT_LISTENER:
449: case SSH_CHANNEL_RPORT_LISTENER:
450: case SSH_CHANNEL_CLOSED:
451: case SSH_CHANNEL_AUTH_SOCKET:
452: case SSH_CHANNEL_DYNAMIC:
453: case SSH_CHANNEL_CONNECTING:
454: case SSH_CHANNEL_ZOMBIE:
455: continue;
456: case SSH_CHANNEL_LARVAL:
457: if (!compat20)
458: fatal("cannot happen: SSH_CHANNEL_LARVAL");
459: continue;
460: case SSH_CHANNEL_OPENING:
461: case SSH_CHANNEL_OPEN:
462: case SSH_CHANNEL_X11_OPEN:
463: return 1;
464: case SSH_CHANNEL_INPUT_DRAINING:
465: case SSH_CHANNEL_OUTPUT_DRAINING:
466: if (!compat13)
467: fatal("cannot happen: OUT_DRAIN");
468: return 1;
469: default:
470: fatal("channel_still_open: bad channel type %d", c->type);
471: /* NOTREACHED */
472: }
473: }
474: return 0;
475: }
476:
477: /* Returns the id of an open channel suitable for keepaliving */
478:
479: int
1.142 itojun 480: channel_find_open(void)
1.121 markus 481: {
482: int i;
483: Channel *c;
484:
485: for (i = 0; i < channels_alloc; i++) {
486: c = channels[i];
487: if (c == NULL)
488: continue;
489: switch (c->type) {
490: case SSH_CHANNEL_CLOSED:
491: case SSH_CHANNEL_DYNAMIC:
492: case SSH_CHANNEL_X11_LISTENER:
493: case SSH_CHANNEL_PORT_LISTENER:
494: case SSH_CHANNEL_RPORT_LISTENER:
495: case SSH_CHANNEL_OPENING:
496: case SSH_CHANNEL_CONNECTING:
497: case SSH_CHANNEL_ZOMBIE:
498: continue;
499: case SSH_CHANNEL_LARVAL:
500: case SSH_CHANNEL_AUTH_SOCKET:
501: case SSH_CHANNEL_OPEN:
502: case SSH_CHANNEL_X11_OPEN:
503: return i;
504: case SSH_CHANNEL_INPUT_DRAINING:
505: case SSH_CHANNEL_OUTPUT_DRAINING:
506: if (!compat13)
507: fatal("cannot happen: OUT_DRAIN");
508: return i;
509: default:
510: fatal("channel_find_open: bad channel type %d", c->type);
511: /* NOTREACHED */
512: }
513: }
514: return -1;
515: }
516:
517:
518: /*
519: * Returns a message describing the currently open forwarded connections,
520: * suitable for sending to the client. The message contains crlf pairs for
521: * newlines.
522: */
523:
524: char *
1.142 itojun 525: channel_open_message(void)
1.121 markus 526: {
527: Buffer buffer;
528: Channel *c;
529: char buf[1024], *cp;
530: int i;
531:
532: buffer_init(&buffer);
533: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
534: buffer_append(&buffer, buf, strlen(buf));
535: for (i = 0; i < channels_alloc; i++) {
536: c = channels[i];
537: if (c == NULL)
538: continue;
539: switch (c->type) {
540: case SSH_CHANNEL_X11_LISTENER:
541: case SSH_CHANNEL_PORT_LISTENER:
542: case SSH_CHANNEL_RPORT_LISTENER:
543: case SSH_CHANNEL_CLOSED:
544: case SSH_CHANNEL_AUTH_SOCKET:
545: case SSH_CHANNEL_ZOMBIE:
546: continue;
547: case SSH_CHANNEL_LARVAL:
548: case SSH_CHANNEL_OPENING:
549: case SSH_CHANNEL_CONNECTING:
550: case SSH_CHANNEL_DYNAMIC:
551: case SSH_CHANNEL_OPEN:
552: case SSH_CHANNEL_X11_OPEN:
553: case SSH_CHANNEL_INPUT_DRAINING:
554: case SSH_CHANNEL_OUTPUT_DRAINING:
555: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
556: c->self, c->remote_name,
557: c->type, c->remote_id,
558: c->istate, buffer_len(&c->input),
559: c->ostate, buffer_len(&c->output),
560: c->rfd, c->wfd);
561: buffer_append(&buffer, buf, strlen(buf));
562: continue;
563: default:
564: fatal("channel_open_message: bad channel type %d", c->type);
565: /* NOTREACHED */
566: }
567: }
568: buffer_append(&buffer, "\0", 1);
569: cp = xstrdup(buffer_ptr(&buffer));
570: buffer_free(&buffer);
571: return cp;
572: }
573:
574: void
575: channel_send_open(int id)
576: {
577: Channel *c = channel_lookup(id);
578: if (c == NULL) {
579: log("channel_send_open: %d: bad id", id);
580: return;
581: }
582: debug("send channel open %d", id);
583: packet_start(SSH2_MSG_CHANNEL_OPEN);
584: packet_put_cstring(c->ctype);
585: packet_put_int(c->self);
586: packet_put_int(c->local_window);
587: packet_put_int(c->local_maxpacket);
588: packet_send();
589: }
590:
591: void
592: channel_request(int id, char *service, int wantconfirm)
593: {
594: channel_request_start(id, service, wantconfirm);
595: packet_send();
596: debug("channel request %d: %s", id, service) ;
597: }
598: void
599: channel_request_start(int id, char *service, int wantconfirm)
600: {
601: Channel *c = channel_lookup(id);
602: if (c == NULL) {
603: log("channel_request: %d: bad id", id);
604: return;
605: }
606: packet_start(SSH2_MSG_CHANNEL_REQUEST);
607: packet_put_int(c->remote_id);
608: packet_put_cstring(service);
609: packet_put_char(wantconfirm);
610: }
611: void
612: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
613: {
614: Channel *c = channel_lookup(id);
615: if (c == NULL) {
616: log("channel_register_callback: %d: bad id", id);
617: return;
618: }
619: c->cb_event = mtype;
620: c->cb_fn = fn;
621: c->cb_arg = arg;
622: }
623: void
624: channel_register_cleanup(int id, channel_callback_fn *fn)
625: {
626: Channel *c = channel_lookup(id);
627: if (c == NULL) {
628: log("channel_register_cleanup: %d: bad id", id);
629: return;
630: }
1.131 markus 631: c->detach_user = fn;
1.121 markus 632: }
633: void
634: channel_cancel_cleanup(int id)
635: {
636: Channel *c = channel_lookup(id);
637: if (c == NULL) {
638: log("channel_cancel_cleanup: %d: bad id", id);
639: return;
1.52 markus 640: }
1.131 markus 641: c->detach_user = NULL;
1.121 markus 642: }
643: void
644: channel_register_filter(int id, channel_filter_fn *fn)
645: {
646: Channel *c = channel_lookup(id);
647: if (c == NULL) {
648: log("channel_register_filter: %d: bad id", id);
649: return;
1.52 markus 650: }
1.121 markus 651: c->input_filter = fn;
1.52 markus 652: }
653:
1.49 markus 654: void
1.121 markus 655: channel_set_fds(int id, int rfd, int wfd, int efd,
656: int extusage, int nonblock)
1.1 deraadt 657: {
1.121 markus 658: Channel *c = channel_lookup(id);
659: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
660: fatal("channel_activate for non-larval channel %d.", id);
661: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
662: c->type = SSH_CHANNEL_OPEN;
663: /* XXX window size? */
664: c->local_window = c->local_window_max = c->local_maxpacket * 2;
665: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
666: packet_put_int(c->remote_id);
667: packet_put_int(c->local_window);
668: packet_send();
1.1 deraadt 669: }
670:
1.27 markus 671: /*
1.41 markus 672: * 'channel_pre*' are called just before select() to add any bits relevant to
673: * channels in the select bitmasks.
674: */
675: /*
676: * 'channel_post*': perform any appropriate operations for channels which
677: * have events pending.
1.27 markus 678: */
1.41 markus 679: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
680: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
681: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
682:
1.127 itojun 683: static void
1.41 markus 684: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
685: {
686: FD_SET(c->sock, readset);
687: }
688:
1.127 itojun 689: static void
1.75 markus 690: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
691: {
692: debug3("channel %d: waiting for connection", c->self);
693: FD_SET(c->sock, writeset);
694: }
695:
1.127 itojun 696: static void
1.41 markus 697: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
698: {
699: if (buffer_len(&c->input) < packet_get_maxsize())
700: FD_SET(c->sock, readset);
701: if (buffer_len(&c->output) > 0)
702: FD_SET(c->sock, writeset);
703: }
1.1 deraadt 704:
1.127 itojun 705: static void
1.41 markus 706: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
707: {
708: /* test whether sockets are 'alive' for read/write */
709: if (c->istate == CHAN_INPUT_OPEN)
710: if (buffer_len(&c->input) < packet_get_maxsize())
711: FD_SET(c->sock, readset);
712: if (c->ostate == CHAN_OUTPUT_OPEN ||
713: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
714: if (buffer_len(&c->output) > 0) {
715: FD_SET(c->sock, writeset);
716: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
717: chan_obuf_empty(c);
718: }
719: }
720: }
721:
1.127 itojun 722: static void
1.44 markus 723: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
724: {
725: if (c->istate == CHAN_INPUT_OPEN &&
726: c->remote_window > 0 &&
727: buffer_len(&c->input) < c->remote_window)
728: FD_SET(c->rfd, readset);
729: if (c->ostate == CHAN_OUTPUT_OPEN ||
730: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
731: if (buffer_len(&c->output) > 0) {
732: FD_SET(c->wfd, writeset);
733: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
734: chan_obuf_empty(c);
735: }
736: }
737: /** XXX check close conditions, too */
738: if (c->efd != -1) {
739: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
740: buffer_len(&c->extended) > 0)
741: FD_SET(c->efd, writeset);
742: else if (c->extended_usage == CHAN_EXTENDED_READ &&
743: buffer_len(&c->extended) < c->remote_window)
744: FD_SET(c->efd, readset);
745: }
746: }
747:
1.127 itojun 748: static void
1.41 markus 749: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
750: {
751: if (buffer_len(&c->input) == 0) {
752: packet_start(SSH_MSG_CHANNEL_CLOSE);
753: packet_put_int(c->remote_id);
754: packet_send();
755: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 756: debug("channel %d: closing after input drain.", c->self);
1.41 markus 757: }
758: }
759:
1.127 itojun 760: static void
1.41 markus 761: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
762: {
763: if (buffer_len(&c->output) == 0)
1.113 markus 764: chan_mark_dead(c);
1.49 markus 765: else
1.41 markus 766: FD_SET(c->sock, writeset);
767: }
768:
769: /*
770: * This is a special state for X11 authentication spoofing. An opened X11
771: * connection (when authentication spoofing is being done) remains in this
772: * state until the first packet has been completely read. The authentication
773: * data in that packet is then substituted by the real data if it matches the
774: * fake data, and the channel is put into normal mode.
1.51 markus 775: * XXX All this happens at the client side.
1.121 markus 776: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 777: */
1.127 itojun 778: static int
1.121 markus 779: x11_open_helper(Buffer *b)
1.1 deraadt 780: {
1.77 markus 781: u_char *ucp;
782: u_int proto_len, data_len;
1.25 markus 783:
1.41 markus 784: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 785: if (buffer_len(b) < 12)
1.41 markus 786: return 0;
787:
788: /* Parse the lengths of variable-length fields. */
1.155 stevesk 789: ucp = buffer_ptr(b);
1.41 markus 790: if (ucp[0] == 0x42) { /* Byte order MSB first. */
791: proto_len = 256 * ucp[6] + ucp[7];
792: data_len = 256 * ucp[8] + ucp[9];
793: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
794: proto_len = ucp[6] + 256 * ucp[7];
795: data_len = ucp[8] + 256 * ucp[9];
796: } else {
797: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 798: ucp[0]);
1.41 markus 799: return -1;
800: }
801:
802: /* Check if the whole packet is in buffer. */
1.121 markus 803: if (buffer_len(b) <
1.41 markus 804: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
805: return 0;
806:
807: /* Check if authentication protocol matches. */
808: if (proto_len != strlen(x11_saved_proto) ||
809: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
810: debug("X11 connection uses different authentication protocol.");
811: return -1;
812: }
813: /* Check if authentication data matches our fake data. */
814: if (data_len != x11_fake_data_len ||
815: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
816: x11_fake_data, x11_fake_data_len) != 0) {
817: debug("X11 auth data does not match fake data.");
818: return -1;
819: }
820: /* Check fake data length */
821: if (x11_fake_data_len != x11_saved_data_len) {
822: error("X11 fake_data_len %d != saved_data_len %d",
823: x11_fake_data_len, x11_saved_data_len);
824: return -1;
825: }
826: /*
827: * Received authentication protocol and data match
828: * our fake data. Substitute the fake data with real
829: * data.
830: */
831: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
832: x11_saved_data, x11_saved_data_len);
833: return 1;
834: }
835:
1.127 itojun 836: static void
1.41 markus 837: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
838: {
1.121 markus 839: int ret = x11_open_helper(&c->output);
1.41 markus 840: if (ret == 1) {
841: /* Start normal processing for the channel. */
842: c->type = SSH_CHANNEL_OPEN;
1.47 markus 843: channel_pre_open_13(c, readset, writeset);
1.41 markus 844: } else if (ret == -1) {
845: /*
846: * We have received an X11 connection that has bad
847: * authentication information.
848: */
1.98 millert 849: log("X11 connection rejected because of wrong authentication.");
1.41 markus 850: buffer_clear(&c->input);
851: buffer_clear(&c->output);
1.132 markus 852: channel_close_fd(&c->sock);
1.41 markus 853: c->sock = -1;
854: c->type = SSH_CHANNEL_CLOSED;
855: packet_start(SSH_MSG_CHANNEL_CLOSE);
856: packet_put_int(c->remote_id);
857: packet_send();
858: }
859: }
1.25 markus 860:
1.127 itojun 861: static void
1.51 markus 862: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 863: {
1.121 markus 864: int ret = x11_open_helper(&c->output);
1.133 markus 865:
866: /* c->force_drain = 1; */
867:
1.41 markus 868: if (ret == 1) {
869: c->type = SSH_CHANNEL_OPEN;
1.57 markus 870: if (compat20)
871: channel_pre_open_20(c, readset, writeset);
872: else
873: channel_pre_open_15(c, readset, writeset);
1.41 markus 874: } else if (ret == -1) {
1.156 ! markus 875: log("X11 connection rejected because of wrong authentication.");
1.41 markus 876: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 ! markus 877: chan_read_failed(c);
! 878: buffer_clear(&c->input);
! 879: chan_ibuf_empty(c);
! 880: buffer_clear(&c->output);
! 881: /* for proto v1, the peer will send an IEOF */
! 882: if (compat20)
! 883: chan_write_failed(c);
! 884: else
! 885: c->type = SSH_CHANNEL_OPEN;
1.41 markus 886: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
887: }
888: }
1.25 markus 889:
1.104 markus 890: /* try to decode a socks4 header */
1.127 itojun 891: static int
1.104 markus 892: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 893: {
894: u_char *p, *host;
1.109 markus 895: int len, have, i, found;
1.148 deraadt 896: char username[256];
1.103 markus 897: struct {
898: u_int8_t version;
899: u_int8_t command;
900: u_int16_t dest_port;
1.104 markus 901: struct in_addr dest_addr;
1.103 markus 902: } s4_req, s4_rsp;
903:
1.104 markus 904: debug2("channel %d: decode socks4", c->self);
1.109 markus 905:
906: have = buffer_len(&c->input);
907: len = sizeof(s4_req);
908: if (have < len)
909: return 0;
910: p = buffer_ptr(&c->input);
911: for (found = 0, i = len; i < have; i++) {
912: if (p[i] == '\0') {
913: found = 1;
914: break;
915: }
916: if (i > 1024) {
917: /* the peer is probably sending garbage */
918: debug("channel %d: decode socks4: too long",
919: c->self);
920: return -1;
921: }
922: }
923: if (!found)
924: return 0;
1.103 markus 925: buffer_get(&c->input, (char *)&s4_req.version, 1);
926: buffer_get(&c->input, (char *)&s4_req.command, 1);
927: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 928: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 929: have = buffer_len(&c->input);
1.103 markus 930: p = buffer_ptr(&c->input);
931: len = strlen(p);
1.106 markus 932: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 933: if (len > have)
1.104 markus 934: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 935: c->self, len, have);
936: strlcpy(username, p, sizeof(username));
937: buffer_consume(&c->input, len);
938: buffer_consume(&c->input, 1); /* trailing '\0' */
939:
1.104 markus 940: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 941: strlcpy(c->path, host, sizeof(c->path));
942: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 943:
1.106 markus 944: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
945: c->self, host, c->host_port, s4_req.command);
1.103 markus 946:
1.104 markus 947: if (s4_req.command != 1) {
948: debug("channel %d: cannot handle: socks4 cn %d",
949: c->self, s4_req.command);
950: return -1;
1.103 markus 951: }
1.104 markus 952: s4_rsp.version = 0; /* vn: 0 for reply */
953: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 954: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 955: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 956: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 957: return 1;
958: }
959:
960: /* dynamic port forwarding */
1.127 itojun 961: static void
1.104 markus 962: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
963: {
964: u_char *p;
965: int have, ret;
1.103 markus 966:
1.104 markus 967: have = buffer_len(&c->input);
1.137 markus 968: c->delayed = 0;
1.104 markus 969: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 970: /* buffer_dump(&c->input); */
1.104 markus 971: /* check if the fixed size part of the packet is in buffer. */
972: if (have < 4) {
973: /* need more */
974: FD_SET(c->sock, readset);
975: return;
976: }
977: /* try to guess the protocol */
978: p = buffer_ptr(&c->input);
979: switch (p[0]) {
980: case 0x04:
981: ret = channel_decode_socks4(c, readset, writeset);
982: break;
983: default:
984: ret = -1;
985: break;
986: }
987: if (ret < 0) {
1.113 markus 988: chan_mark_dead(c);
1.104 markus 989: } else if (ret == 0) {
990: debug2("channel %d: pre_dynamic: need more", c->self);
991: /* need more */
992: FD_SET(c->sock, readset);
993: } else {
994: /* switch to the next state */
995: c->type = SSH_CHANNEL_OPENING;
996: port_open_helper(c, "direct-tcpip");
997: }
1.103 markus 998: }
999:
1.41 markus 1000: /* This is our fake X11 server socket. */
1.127 itojun 1001: static void
1.41 markus 1002: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1003: {
1.113 markus 1004: Channel *nc;
1.41 markus 1005: struct sockaddr addr;
1.146 stevesk 1006: int newsock, on = 1;
1.41 markus 1007: socklen_t addrlen;
1.85 markus 1008: char buf[16384], *remote_ipaddr;
1.51 markus 1009: int remote_port;
1.25 markus 1010:
1.41 markus 1011: if (FD_ISSET(c->sock, readset)) {
1012: debug("X11 connection requested.");
1013: addrlen = sizeof(addr);
1014: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1015: if (c->single_connection) {
1016: debug("single_connection: closing X11 listener.");
1017: channel_close_fd(&c->sock);
1018: chan_mark_dead(c);
1019: }
1.41 markus 1020: if (newsock < 0) {
1021: error("accept: %.100s", strerror(errno));
1022: return;
1023: }
1.146 stevesk 1024: if (setsockopt(newsock, IPPROTO_TCP, TCP_NODELAY, &on,
1025: sizeof on) == -1)
1026: error("setsockopt TCP_NODELAY: %.100s",
1027: strerror(errno));
1.85 markus 1028: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1029: remote_port = get_peer_port(newsock);
1.41 markus 1030: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1031: remote_ipaddr, remote_port);
1.51 markus 1032:
1.113 markus 1033: nc = channel_new("accepted x11 socket",
1.51 markus 1034: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1035: c->local_window_max, c->local_maxpacket,
1.71 markus 1036: 0, xstrdup(buf), 1);
1.113 markus 1037: if (nc == NULL) {
1038: close(newsock);
1039: xfree(remote_ipaddr);
1040: return;
1041: }
1.51 markus 1042: if (compat20) {
1043: packet_start(SSH2_MSG_CHANNEL_OPEN);
1044: packet_put_cstring("x11");
1.113 markus 1045: packet_put_int(nc->self);
1.149 markus 1046: packet_put_int(nc->local_window_max);
1047: packet_put_int(nc->local_maxpacket);
1.85 markus 1048: /* originator ipaddr and port */
1049: packet_put_cstring(remote_ipaddr);
1.57 markus 1050: if (datafellows & SSH_BUG_X11FWD) {
1051: debug("ssh2 x11 bug compat mode");
1052: } else {
1053: packet_put_int(remote_port);
1054: }
1.51 markus 1055: packet_send();
1056: } else {
1057: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1058: packet_put_int(nc->self);
1.121 markus 1059: if (packet_get_protocol_flags() &
1060: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1061: packet_put_cstring(buf);
1.51 markus 1062: packet_send();
1063: }
1.85 markus 1064: xfree(remote_ipaddr);
1.41 markus 1065: }
1066: }
1.25 markus 1067:
1.127 itojun 1068: static void
1.103 markus 1069: port_open_helper(Channel *c, char *rtype)
1070: {
1071: int direct;
1072: char buf[1024];
1073: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1074: u_short remote_port = get_peer_port(c->sock);
1075:
1076: direct = (strcmp(rtype, "direct-tcpip") == 0);
1077:
1078: snprintf(buf, sizeof buf,
1079: "%s: listening port %d for %.100s port %d, "
1080: "connect from %.200s port %d",
1081: rtype, c->listening_port, c->path, c->host_port,
1082: remote_ipaddr, remote_port);
1083:
1084: xfree(c->remote_name);
1085: c->remote_name = xstrdup(buf);
1086:
1087: if (compat20) {
1088: packet_start(SSH2_MSG_CHANNEL_OPEN);
1089: packet_put_cstring(rtype);
1090: packet_put_int(c->self);
1091: packet_put_int(c->local_window_max);
1092: packet_put_int(c->local_maxpacket);
1093: if (direct) {
1094: /* target host, port */
1095: packet_put_cstring(c->path);
1096: packet_put_int(c->host_port);
1097: } else {
1098: /* listen address, port */
1099: packet_put_cstring(c->path);
1100: packet_put_int(c->listening_port);
1101: }
1102: /* originator host and port */
1103: packet_put_cstring(remote_ipaddr);
1104: packet_put_int(remote_port);
1105: packet_send();
1106: } else {
1107: packet_start(SSH_MSG_PORT_OPEN);
1108: packet_put_int(c->self);
1109: packet_put_cstring(c->path);
1110: packet_put_int(c->host_port);
1.121 markus 1111: if (packet_get_protocol_flags() &
1112: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1113: packet_put_cstring(c->remote_name);
1114: packet_send();
1115: }
1116: xfree(remote_ipaddr);
1117: }
1118:
1.41 markus 1119: /*
1120: * This socket is listening for connections to a forwarded TCP/IP port.
1121: */
1.127 itojun 1122: static void
1.41 markus 1123: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1124: {
1.103 markus 1125: Channel *nc;
1.41 markus 1126: struct sockaddr addr;
1.113 markus 1127: int newsock, nextstate;
1.41 markus 1128: socklen_t addrlen;
1.103 markus 1129: char *rtype;
1.73 markus 1130:
1.41 markus 1131: if (FD_ISSET(c->sock, readset)) {
1132: debug("Connection to port %d forwarding "
1133: "to %.100s port %d requested.",
1134: c->listening_port, c->path, c->host_port);
1.103 markus 1135:
1.137 markus 1136: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1137: nextstate = SSH_CHANNEL_OPENING;
1138: rtype = "forwarded-tcpip";
1139: } else {
1140: if (c->host_port == 0) {
1141: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1142: rtype = "dynamic-tcpip";
1.137 markus 1143: } else {
1144: nextstate = SSH_CHANNEL_OPENING;
1145: rtype = "direct-tcpip";
1146: }
1147: }
1.103 markus 1148:
1.41 markus 1149: addrlen = sizeof(addr);
1150: newsock = accept(c->sock, &addr, &addrlen);
1151: if (newsock < 0) {
1152: error("accept: %.100s", strerror(errno));
1153: return;
1154: }
1.113 markus 1155: nc = channel_new(rtype,
1.103 markus 1156: nextstate, newsock, newsock, -1,
1.41 markus 1157: c->local_window_max, c->local_maxpacket,
1.103 markus 1158: 0, xstrdup(rtype), 1);
1159: if (nc == NULL) {
1.113 markus 1160: error("channel_post_port_listener: no new channel:");
1161: close(newsock);
1.103 markus 1162: return;
1.41 markus 1163: }
1.103 markus 1164: nc->listening_port = c->listening_port;
1165: nc->host_port = c->host_port;
1166: strlcpy(nc->path, c->path, sizeof(nc->path));
1167:
1.137 markus 1168: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1169: /*
1170: * do not call the channel_post handler until
1171: * this flag has been reset by a pre-handler.
1172: * otherwise the FD_ISSET calls might overflow
1173: */
1174: nc->delayed = 1;
1175: } else {
1.103 markus 1176: port_open_helper(nc, rtype);
1.137 markus 1177: }
1.41 markus 1178: }
1179: }
1.25 markus 1180:
1.41 markus 1181: /*
1182: * This is the authentication agent socket listening for connections from
1183: * clients.
1184: */
1.127 itojun 1185: static void
1.41 markus 1186: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1187: {
1.113 markus 1188: Channel *nc;
1.121 markus 1189: char *name;
1.113 markus 1190: int newsock;
1.41 markus 1191: struct sockaddr addr;
1192: socklen_t addrlen;
1.25 markus 1193:
1.41 markus 1194: if (FD_ISSET(c->sock, readset)) {
1195: addrlen = sizeof(addr);
1196: newsock = accept(c->sock, &addr, &addrlen);
1197: if (newsock < 0) {
1198: error("accept from auth socket: %.100s", strerror(errno));
1199: return;
1200: }
1.121 markus 1201: name = xstrdup("accepted auth socket");
1.113 markus 1202: nc = channel_new("accepted auth socket",
1.73 markus 1203: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1204: c->local_window_max, c->local_maxpacket,
1.121 markus 1205: 0, name, 1);
1.113 markus 1206: if (nc == NULL) {
1207: error("channel_post_auth_listener: channel_new failed");
1.121 markus 1208: xfree(name);
1.113 markus 1209: close(newsock);
1210: }
1.73 markus 1211: if (compat20) {
1212: packet_start(SSH2_MSG_CHANNEL_OPEN);
1213: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1214: packet_put_int(nc->self);
1.73 markus 1215: packet_put_int(c->local_window_max);
1216: packet_put_int(c->local_maxpacket);
1217: } else {
1218: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1219: packet_put_int(nc->self);
1.73 markus 1220: }
1.41 markus 1221: packet_send();
1222: }
1223: }
1.25 markus 1224:
1.127 itojun 1225: static void
1.75 markus 1226: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1227: {
1.114 markus 1228: int err = 0;
1.129 stevesk 1229: socklen_t sz = sizeof(err);
1.114 markus 1230:
1.75 markus 1231: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1232: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1233: &sz) < 0) {
1234: err = errno;
1235: error("getsockopt SO_ERROR failed");
1236: }
1237: if (err == 0) {
1238: debug("channel %d: connected", c->self);
1239: c->type = SSH_CHANNEL_OPEN;
1240: if (compat20) {
1241: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1242: packet_put_int(c->remote_id);
1243: packet_put_int(c->self);
1244: packet_put_int(c->local_window);
1245: packet_put_int(c->local_maxpacket);
1246: } else {
1247: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1248: packet_put_int(c->remote_id);
1249: packet_put_int(c->self);
1250: }
1.75 markus 1251: } else {
1.114 markus 1252: debug("channel %d: not connected: %s",
1253: c->self, strerror(err));
1254: if (compat20) {
1255: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1256: packet_put_int(c->remote_id);
1257: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1258: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1259: packet_put_cstring(strerror(err));
1260: packet_put_cstring("");
1261: }
1.75 markus 1262: } else {
1.114 markus 1263: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1264: packet_put_int(c->remote_id);
1.75 markus 1265: }
1.114 markus 1266: chan_mark_dead(c);
1.75 markus 1267: }
1.114 markus 1268: packet_send();
1.75 markus 1269: }
1270: }
1271:
1.127 itojun 1272: static int
1.41 markus 1273: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1274: {
1275: char buf[16*1024];
1276: int len;
1.25 markus 1277:
1.118 markus 1278: if (c->rfd != -1 &&
1.41 markus 1279: FD_ISSET(c->rfd, readset)) {
1280: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1281: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1282: return 1;
1.41 markus 1283: if (len <= 0) {
1.51 markus 1284: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1285: c->self, c->rfd, len);
1.104 markus 1286: if (c->type != SSH_CHANNEL_OPEN) {
1287: debug("channel %d: not open", c->self);
1.113 markus 1288: chan_mark_dead(c);
1.103 markus 1289: return -1;
1.104 markus 1290: } else if (compat13) {
1.41 markus 1291: buffer_consume(&c->output, buffer_len(&c->output));
1292: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1293: debug("channel %d: input draining.", c->self);
1.25 markus 1294: } else {
1.41 markus 1295: chan_read_failed(c);
1.25 markus 1296: }
1.41 markus 1297: return -1;
1298: }
1.143 deraadt 1299: if (c->input_filter != NULL) {
1.66 markus 1300: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1301: debug("channel %d: filter stops", c->self);
1.65 markus 1302: chan_read_failed(c);
1303: }
1304: } else {
1305: buffer_append(&c->input, buf, len);
1306: }
1.41 markus 1307: }
1308: return 1;
1309: }
1.127 itojun 1310: static int
1.41 markus 1311: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1312: {
1.95 markus 1313: struct termios tio;
1.134 markus 1314: u_char *data;
1315: u_int dlen;
1.41 markus 1316: int len;
1.25 markus 1317:
1.41 markus 1318: /* Send buffered output data to the socket. */
1.118 markus 1319: if (c->wfd != -1 &&
1.41 markus 1320: FD_ISSET(c->wfd, writeset) &&
1321: buffer_len(&c->output) > 0) {
1.134 markus 1322: data = buffer_ptr(&c->output);
1323: dlen = buffer_len(&c->output);
1324: len = write(c->wfd, data, dlen);
1.53 markus 1325: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1326: return 1;
1.41 markus 1327: if (len <= 0) {
1.104 markus 1328: if (c->type != SSH_CHANNEL_OPEN) {
1329: debug("channel %d: not open", c->self);
1.113 markus 1330: chan_mark_dead(c);
1.104 markus 1331: return -1;
1332: } else if (compat13) {
1.41 markus 1333: buffer_consume(&c->output, buffer_len(&c->output));
1.121 markus 1334: debug("channel %d: input draining.", c->self);
1.41 markus 1335: c->type = SSH_CHANNEL_INPUT_DRAINING;
1336: } else {
1337: chan_write_failed(c);
1338: }
1339: return -1;
1.91 markus 1340: }
1.134 markus 1341: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1342: if (tcgetattr(c->wfd, &tio) == 0 &&
1343: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1344: /*
1345: * Simulate echo to reduce the impact of
1.96 markus 1346: * traffic analysis. We need to match the
1.95 markus 1347: * size of a SSH2_MSG_CHANNEL_DATA message
1348: * (4 byte channel id + data)
1.91 markus 1349: */
1.95 markus 1350: packet_send_ignore(4 + len);
1.91 markus 1351: packet_send();
1352: }
1.25 markus 1353: }
1.41 markus 1354: buffer_consume(&c->output, len);
1.44 markus 1355: if (compat20 && len > 0) {
1356: c->local_consumed += len;
1357: }
1358: }
1359: return 1;
1360: }
1.127 itojun 1361: static int
1.44 markus 1362: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1363: {
1364: char buf[16*1024];
1365: int len;
1366:
1.45 markus 1367: /** XXX handle drain efd, too */
1.44 markus 1368: if (c->efd != -1) {
1369: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1370: FD_ISSET(c->efd, writeset) &&
1371: buffer_len(&c->extended) > 0) {
1372: len = write(c->efd, buffer_ptr(&c->extended),
1373: buffer_len(&c->extended));
1.70 markus 1374: debug2("channel %d: written %d to efd %d",
1.44 markus 1375: c->self, len, c->efd);
1.93 markus 1376: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1377: return 1;
1378: if (len <= 0) {
1379: debug2("channel %d: closing write-efd %d",
1380: c->self, c->efd);
1.132 markus 1381: channel_close_fd(&c->efd);
1.93 markus 1382: } else {
1.44 markus 1383: buffer_consume(&c->extended, len);
1384: c->local_consumed += len;
1385: }
1386: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1387: FD_ISSET(c->efd, readset)) {
1388: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1389: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1390: c->self, len, c->efd);
1.93 markus 1391: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1392: return 1;
1393: if (len <= 0) {
1394: debug2("channel %d: closing read-efd %d",
1.45 markus 1395: c->self, c->efd);
1.132 markus 1396: channel_close_fd(&c->efd);
1.93 markus 1397: } else {
1.44 markus 1398: buffer_append(&c->extended, buf, len);
1.93 markus 1399: }
1.44 markus 1400: }
1401: }
1402: return 1;
1403: }
1.127 itojun 1404: static int
1.93 markus 1405: channel_check_window(Channel *c)
1.44 markus 1406: {
1.104 markus 1407: if (c->type == SSH_CHANNEL_OPEN &&
1408: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1409: c->local_window < c->local_window_max/2 &&
1410: c->local_consumed > 0) {
1411: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1412: packet_put_int(c->remote_id);
1413: packet_put_int(c->local_consumed);
1414: packet_send();
1.70 markus 1415: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1416: c->self, c->local_window,
1417: c->local_consumed);
1418: c->local_window += c->local_consumed;
1419: c->local_consumed = 0;
1.1 deraadt 1420: }
1.41 markus 1421: return 1;
1.1 deraadt 1422: }
1423:
1.127 itojun 1424: static void
1.41 markus 1425: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1426: {
1.137 markus 1427: if (c->delayed)
1428: return;
1.41 markus 1429: channel_handle_rfd(c, readset, writeset);
1430: channel_handle_wfd(c, readset, writeset);
1431: }
1.1 deraadt 1432:
1.127 itojun 1433: static void
1.44 markus 1434: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1435: {
1.137 markus 1436: if (c->delayed)
1437: return;
1.44 markus 1438: channel_handle_rfd(c, readset, writeset);
1439: channel_handle_wfd(c, readset, writeset);
1440: channel_handle_efd(c, readset, writeset);
1.93 markus 1441:
1442: channel_check_window(c);
1.44 markus 1443: }
1444:
1.127 itojun 1445: static void
1.41 markus 1446: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1447: {
1.41 markus 1448: int len;
1449: /* Send buffered output data to the socket. */
1450: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1451: len = write(c->sock, buffer_ptr(&c->output),
1452: buffer_len(&c->output));
1453: if (len <= 0)
1454: buffer_consume(&c->output, buffer_len(&c->output));
1455: else
1456: buffer_consume(&c->output, len);
1457: }
1458: }
1.25 markus 1459:
1.127 itojun 1460: static void
1.44 markus 1461: channel_handler_init_20(void)
1462: {
1463: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1464: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1465: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1466: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1467: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1468: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1469: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1470: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1471:
1472: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1473: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1474: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1475: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1476: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1477: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1478: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1479: }
1480:
1.127 itojun 1481: static void
1.41 markus 1482: channel_handler_init_13(void)
1483: {
1484: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1485: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1486: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1487: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1488: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1489: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1490: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1491: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1492: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1493:
1.41 markus 1494: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1495: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1496: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1497: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1498: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1499: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1500: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1501: }
1.25 markus 1502:
1.127 itojun 1503: static void
1.41 markus 1504: channel_handler_init_15(void)
1505: {
1506: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1507: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1508: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1509: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1510: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1511: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1512: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1513:
1.41 markus 1514: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1515: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1516: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1517: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1518: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1519: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1520: }
1.27 markus 1521:
1.127 itojun 1522: static void
1.41 markus 1523: channel_handler_init(void)
1524: {
1525: int i;
1.148 deraadt 1526: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1527: channel_pre[i] = NULL;
1528: channel_post[i] = NULL;
1529: }
1.44 markus 1530: if (compat20)
1531: channel_handler_init_20();
1532: else if (compat13)
1.41 markus 1533: channel_handler_init_13();
1534: else
1535: channel_handler_init_15();
1536: }
1.25 markus 1537:
1.140 markus 1538: /* gc dead channels */
1539: static void
1540: channel_garbage_collect(Channel *c)
1541: {
1542: if (c == NULL)
1543: return;
1544: if (c->detach_user != NULL) {
1545: if (!chan_is_dead(c, 0))
1546: return;
1547: debug("channel %d: gc: notify user", c->self);
1548: c->detach_user(c->self, NULL);
1549: /* if we still have a callback */
1550: if (c->detach_user != NULL)
1551: return;
1552: debug("channel %d: gc: user detached", c->self);
1553: }
1554: if (!chan_is_dead(c, 1))
1555: return;
1556: debug("channel %d: garbage collecting", c->self);
1557: channel_free(c);
1558: }
1559:
1.127 itojun 1560: static void
1.41 markus 1561: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1562: {
1563: static int did_init = 0;
1564: int i;
1565: Channel *c;
1.25 markus 1566:
1.41 markus 1567: if (!did_init) {
1568: channel_handler_init();
1569: did_init = 1;
1570: }
1571: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1572: c = channels[i];
1573: if (c == NULL)
1.41 markus 1574: continue;
1.118 markus 1575: if (ftab[c->type] != NULL)
1576: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1577: channel_garbage_collect(c);
1.1 deraadt 1578: }
1579: }
1580:
1.121 markus 1581: /*
1582: * Allocate/update select bitmasks and add any bits relevant to channels in
1583: * select bitmasks.
1584: */
1.49 markus 1585: void
1.100 markus 1586: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1587: int *nallocp, int rekeying)
1.41 markus 1588: {
1.84 markus 1589: int n;
1590: u_int sz;
1591:
1592: n = MAX(*maxfdp, channel_max_fd);
1593:
1594: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1595: /* perhaps check sz < nalloc/2 and shrink? */
1596: if (*readsetp == NULL || sz > *nallocp) {
1597: *readsetp = xrealloc(*readsetp, sz);
1598: *writesetp = xrealloc(*writesetp, sz);
1599: *nallocp = sz;
1.84 markus 1600: }
1.132 markus 1601: *maxfdp = n;
1.84 markus 1602: memset(*readsetp, 0, sz);
1603: memset(*writesetp, 0, sz);
1604:
1.100 markus 1605: if (!rekeying)
1606: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1607: }
1608:
1.121 markus 1609: /*
1610: * After select, perform any appropriate operations for channels which have
1611: * events pending.
1612: */
1.49 markus 1613: void
1.41 markus 1614: channel_after_select(fd_set * readset, fd_set * writeset)
1615: {
1616: channel_handler(channel_post, readset, writeset);
1617: }
1618:
1.121 markus 1619:
1.84 markus 1620: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1621:
1.49 markus 1622: void
1.142 itojun 1623: channel_output_poll(void)
1.1 deraadt 1624: {
1.25 markus 1625: int len, i;
1.41 markus 1626: Channel *c;
1.1 deraadt 1627:
1.25 markus 1628: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1629: c = channels[i];
1630: if (c == NULL)
1631: continue;
1.37 markus 1632:
1.121 markus 1633: /*
1634: * We are only interested in channels that can have buffered
1635: * incoming data.
1636: */
1.37 markus 1637: if (compat13) {
1.41 markus 1638: if (c->type != SSH_CHANNEL_OPEN &&
1639: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1640: continue;
1641: } else {
1.41 markus 1642: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1643: continue;
1644: }
1.46 markus 1645: if (compat20 &&
1646: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1647: /* XXX is this true? */
1.140 markus 1648: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1649: continue;
1650: }
1.25 markus 1651:
1652: /* Get the amount of buffered data for this channel. */
1.93 markus 1653: if ((c->istate == CHAN_INPUT_OPEN ||
1654: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1655: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1656: /*
1657: * Send some data for the other side over the secure
1658: * connection.
1659: */
1.44 markus 1660: if (compat20) {
1661: if (len > c->remote_window)
1662: len = c->remote_window;
1663: if (len > c->remote_maxpacket)
1664: len = c->remote_maxpacket;
1.25 markus 1665: } else {
1.44 markus 1666: if (packet_is_interactive()) {
1667: if (len > 1024)
1668: len = 512;
1669: } else {
1670: /* Keep the packets at reasonable size. */
1671: if (len > packet_get_maxsize()/2)
1672: len = packet_get_maxsize()/2;
1673: }
1.25 markus 1674: }
1.41 markus 1675: if (len > 0) {
1.44 markus 1676: packet_start(compat20 ?
1677: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1678: packet_put_int(c->remote_id);
1679: packet_put_string(buffer_ptr(&c->input), len);
1680: packet_send();
1681: buffer_consume(&c->input, len);
1682: c->remote_window -= len;
1683: }
1684: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1685: if (compat13)
1686: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1687: /*
1688: * input-buffer is empty and read-socket shutdown:
1689: * tell peer, that we will not send more data: send IEOF
1690: */
1.41 markus 1691: chan_ibuf_empty(c);
1.25 markus 1692: }
1.44 markus 1693: /* Send extended data, i.e. stderr */
1694: if (compat20 &&
1695: c->remote_window > 0 &&
1696: (len = buffer_len(&c->extended)) > 0 &&
1697: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1698: debug2("channel %d: rwin %d elen %d euse %d",
1699: c->self, c->remote_window, buffer_len(&c->extended),
1700: c->extended_usage);
1.44 markus 1701: if (len > c->remote_window)
1702: len = c->remote_window;
1703: if (len > c->remote_maxpacket)
1704: len = c->remote_maxpacket;
1705: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1706: packet_put_int(c->remote_id);
1707: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1708: packet_put_string(buffer_ptr(&c->extended), len);
1709: packet_send();
1710: buffer_consume(&c->extended, len);
1711: c->remote_window -= len;
1.93 markus 1712: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1713: }
1.25 markus 1714: }
1.1 deraadt 1715: }
1716:
1.121 markus 1717:
1718: /* -- protocol input */
1.1 deraadt 1719:
1.49 markus 1720: void
1.154 markus 1721: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1722: {
1.37 markus 1723: int id;
1.25 markus 1724: char *data;
1.77 markus 1725: u_int data_len;
1.41 markus 1726: Channel *c;
1.25 markus 1727:
1728: /* Get the channel number and verify it. */
1.37 markus 1729: id = packet_get_int();
1.41 markus 1730: c = channel_lookup(id);
1731: if (c == NULL)
1.37 markus 1732: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1733:
1734: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1735: if (c->type != SSH_CHANNEL_OPEN &&
1736: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1737: return;
1738:
1739: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1740: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1741: return;
1742:
1743: /* Get the data. */
1744: data = packet_get_string(&data_len);
1.41 markus 1745:
1.143 deraadt 1746: if (compat20) {
1.44 markus 1747: if (data_len > c->local_maxpacket) {
1748: log("channel %d: rcvd big packet %d, maxpack %d",
1749: c->self, data_len, c->local_maxpacket);
1750: }
1751: if (data_len > c->local_window) {
1752: log("channel %d: rcvd too much data %d, win %d",
1753: c->self, data_len, c->local_window);
1754: xfree(data);
1755: return;
1756: }
1757: c->local_window -= data_len;
1758: }
1.152 markus 1759: packet_check_eom();
1.41 markus 1760: buffer_append(&c->output, data, data_len);
1.25 markus 1761: xfree(data);
1.1 deraadt 1762: }
1.121 markus 1763:
1.49 markus 1764: void
1.154 markus 1765: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1766: {
1767: int id;
1768: int tcode;
1769: char *data;
1.77 markus 1770: u_int data_len;
1.44 markus 1771: Channel *c;
1772:
1773: /* Get the channel number and verify it. */
1774: id = packet_get_int();
1775: c = channel_lookup(id);
1776:
1777: if (c == NULL)
1778: packet_disconnect("Received extended_data for bad channel %d.", id);
1779: if (c->type != SSH_CHANNEL_OPEN) {
1780: log("channel %d: ext data for non open", id);
1781: return;
1782: }
1783: tcode = packet_get_int();
1784: if (c->efd == -1 ||
1785: c->extended_usage != CHAN_EXTENDED_WRITE ||
1786: tcode != SSH2_EXTENDED_DATA_STDERR) {
1787: log("channel %d: bad ext data", c->self);
1788: return;
1789: }
1790: data = packet_get_string(&data_len);
1.152 markus 1791: packet_check_eom();
1.44 markus 1792: if (data_len > c->local_window) {
1793: log("channel %d: rcvd too much extended_data %d, win %d",
1794: c->self, data_len, c->local_window);
1795: xfree(data);
1796: return;
1797: }
1.70 markus 1798: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1799: c->local_window -= data_len;
1800: buffer_append(&c->extended, data, data_len);
1801: xfree(data);
1802: }
1803:
1.49 markus 1804: void
1.154 markus 1805: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1806: {
1807: int id;
1808: Channel *c;
1809:
1810: id = packet_get_int();
1.152 markus 1811: packet_check_eom();
1.41 markus 1812: c = channel_lookup(id);
1813: if (c == NULL)
1814: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1815: chan_rcvd_ieof(c);
1.133 markus 1816:
1817: /* XXX force input close */
1.156 ! markus 1818: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1819: debug("channel %d: FORCE input drain", c->self);
1820: c->istate = CHAN_INPUT_WAIT_DRAIN;
1821: }
1822:
1.41 markus 1823: }
1.1 deraadt 1824:
1.49 markus 1825: void
1.154 markus 1826: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1827: {
1.41 markus 1828: int id;
1829: Channel *c;
1.1 deraadt 1830:
1.41 markus 1831: id = packet_get_int();
1.152 markus 1832: packet_check_eom();
1.41 markus 1833: c = channel_lookup(id);
1834: if (c == NULL)
1835: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1836:
1837: /*
1838: * Send a confirmation that we have closed the channel and no more
1839: * data is coming for it.
1840: */
1.25 markus 1841: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1842: packet_put_int(c->remote_id);
1.25 markus 1843: packet_send();
1844:
1.27 markus 1845: /*
1846: * If the channel is in closed state, we have sent a close request,
1847: * and the other side will eventually respond with a confirmation.
1848: * Thus, we cannot free the channel here, because then there would be
1849: * no-one to receive the confirmation. The channel gets freed when
1850: * the confirmation arrives.
1851: */
1.41 markus 1852: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1853: /*
1854: * Not a closed channel - mark it as draining, which will
1855: * cause it to be freed later.
1856: */
1.41 markus 1857: buffer_consume(&c->input, buffer_len(&c->input));
1858: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1859: }
1.1 deraadt 1860: }
1861:
1.41 markus 1862: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1863: void
1.154 markus 1864: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1865: {
1866: int id = packet_get_int();
1867: Channel *c = channel_lookup(id);
1.151 markus 1868:
1.152 markus 1869: packet_check_eom();
1.41 markus 1870: if (c == NULL)
1871: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1872: chan_rcvd_oclose(c);
1873: }
1.1 deraadt 1874:
1.49 markus 1875: void
1.154 markus 1876: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1877: {
1.41 markus 1878: int id = packet_get_int();
1879: Channel *c = channel_lookup(id);
1.1 deraadt 1880:
1.152 markus 1881: packet_check_eom();
1.41 markus 1882: if (c == NULL)
1883: packet_disconnect("Received close confirmation for "
1884: "out-of-range channel %d.", id);
1885: if (c->type != SSH_CHANNEL_CLOSED)
1886: packet_disconnect("Received close confirmation for "
1887: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1888: channel_free(c);
1.1 deraadt 1889: }
1890:
1.49 markus 1891: void
1.154 markus 1892: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1893: {
1.41 markus 1894: int id, remote_id;
1895: Channel *c;
1.1 deraadt 1896:
1.41 markus 1897: id = packet_get_int();
1898: c = channel_lookup(id);
1.25 markus 1899:
1.41 markus 1900: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1901: packet_disconnect("Received open confirmation for "
1902: "non-opening channel %d.", id);
1903: remote_id = packet_get_int();
1.27 markus 1904: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1905: c->remote_id = remote_id;
1906: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1907:
1908: if (compat20) {
1909: c->remote_window = packet_get_int();
1910: c->remote_maxpacket = packet_get_int();
1911: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1912: debug2("callback start");
1.44 markus 1913: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1914: debug2("callback done");
1.44 markus 1915: }
1916: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1917: c->remote_window, c->remote_maxpacket);
1918: }
1.152 markus 1919: packet_check_eom();
1.1 deraadt 1920: }
1921:
1.127 itojun 1922: static char *
1.114 markus 1923: reason2txt(int reason)
1924: {
1.143 deraadt 1925: switch (reason) {
1.114 markus 1926: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1927: return "administratively prohibited";
1928: case SSH2_OPEN_CONNECT_FAILED:
1929: return "connect failed";
1930: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1931: return "unknown channel type";
1932: case SSH2_OPEN_RESOURCE_SHORTAGE:
1933: return "resource shortage";
1934: }
1.117 stevesk 1935: return "unknown reason";
1.114 markus 1936: }
1937:
1.49 markus 1938: void
1.154 markus 1939: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1940: {
1.86 markus 1941: int id, reason;
1942: char *msg = NULL, *lang = NULL;
1.41 markus 1943: Channel *c;
1944:
1945: id = packet_get_int();
1946: c = channel_lookup(id);
1.25 markus 1947:
1.41 markus 1948: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1949: packet_disconnect("Received open failure for "
1950: "non-opening channel %d.", id);
1.44 markus 1951: if (compat20) {
1.86 markus 1952: reason = packet_get_int();
1.110 markus 1953: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1954: msg = packet_get_string(NULL);
1955: lang = packet_get_string(NULL);
1956: }
1.114 markus 1957: log("channel %d: open failed: %s%s%s", id,
1958: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1959: if (msg != NULL)
1960: xfree(msg);
1961: if (lang != NULL)
1962: xfree(lang);
1.44 markus 1963: }
1.152 markus 1964: packet_check_eom();
1.25 markus 1965: /* Free the channel. This will also close the socket. */
1.113 markus 1966: channel_free(c);
1.1 deraadt 1967: }
1968:
1.44 markus 1969: void
1.154 markus 1970: channel_input_channel_request(int type, u_int32_t seq, void *ctxt)
1.44 markus 1971: {
1972: int id;
1973: Channel *c;
1974:
1975: id = packet_get_int();
1976: c = channel_lookup(id);
1977:
1978: if (c == NULL ||
1979: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1980: packet_disconnect("Received request for "
1981: "non-open channel %d.", id);
1982: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1983: debug2("callback start");
1.44 markus 1984: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1985: debug2("callback done");
1.44 markus 1986: } else {
1987: char *service = packet_get_string(NULL);
1.94 markus 1988: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1989: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1990: xfree(service);
1991: }
1992: }
1993:
1.121 markus 1994: void
1.154 markus 1995: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1996: {
1997: Channel *c;
1998: int id, adjust;
1999:
2000: if (!compat20)
2001: return;
2002:
2003: /* Get the channel number and verify it. */
2004: id = packet_get_int();
2005: c = channel_lookup(id);
1.1 deraadt 2006:
1.121 markus 2007: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
2008: log("Received window adjust for "
2009: "non-open channel %d.", id);
2010: return;
2011: }
2012: adjust = packet_get_int();
1.152 markus 2013: packet_check_eom();
1.121 markus 2014: debug2("channel %d: rcvd adjust %d", id, adjust);
2015: c->remote_window += adjust;
2016: }
1.1 deraadt 2017:
1.121 markus 2018: void
1.154 markus 2019: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2020: {
1.121 markus 2021: Channel *c = NULL;
2022: u_short host_port;
2023: char *host, *originator_string;
2024: int remote_id, sock = -1;
2025:
2026: remote_id = packet_get_int();
2027: host = packet_get_string(NULL);
2028: host_port = packet_get_int();
1.25 markus 2029:
1.121 markus 2030: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2031: originator_string = packet_get_string(NULL);
2032: } else {
2033: originator_string = xstrdup("unknown (remote did not supply name)");
2034: }
1.152 markus 2035: packet_check_eom();
1.121 markus 2036: sock = channel_connect_to(host, host_port);
2037: if (sock != -1) {
2038: c = channel_new("connected socket",
2039: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2040: originator_string, 1);
2041: if (c == NULL) {
2042: error("channel_input_port_open: channel_new failed");
2043: close(sock);
2044: } else {
2045: c->remote_id = remote_id;
1.25 markus 2046: }
2047: }
1.121 markus 2048: if (c == NULL) {
2049: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2050: packet_put_int(remote_id);
2051: packet_send();
2052: }
2053: xfree(host);
1.1 deraadt 2054: }
2055:
1.121 markus 2056:
2057: /* -- tcp forwarding */
1.135 markus 2058:
2059: void
2060: channel_set_af(int af)
2061: {
2062: IPv4or6 = af;
2063: }
1.121 markus 2064:
1.27 markus 2065: /*
2066: * Initiate forwarding of connections to local port "port" through the secure
2067: * channel to host:port from remote side.
2068: */
1.87 markus 2069: int
1.73 markus 2070: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
2071: u_short port_to_connect, int gateway_ports)
2072: {
1.87 markus 2073: return channel_request_forwarding(
1.73 markus 2074: NULL, listen_port,
2075: host_to_connect, port_to_connect,
2076: gateway_ports, /*remote_fwd*/ 0);
2077: }
1.1 deraadt 2078:
1.73 markus 2079: /*
2080: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
2081: * (SSH_CHANNEL_RPORT_LISTENER).
2082: */
1.87 markus 2083: int
1.73 markus 2084: channel_request_forwarding(
2085: const char *listen_address, u_short listen_port,
2086: const char *host_to_connect, u_short port_to_connect,
2087: int gateway_ports, int remote_fwd)
1.25 markus 2088: {
1.113 markus 2089: Channel *c;
1.121 markus 2090: int success, sock, on = 1, type;
1.35 markus 2091: struct addrinfo hints, *ai, *aitop;
2092: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 2093: const char *host;
1.28 markus 2094: struct linger linger;
1.25 markus 2095:
1.87 markus 2096: success = 0;
2097:
1.73 markus 2098: if (remote_fwd) {
2099: host = listen_address;
1.121 markus 2100: type = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 2101: } else {
2102: host = host_to_connect;
1.121 markus 2103: type = SSH_CHANNEL_PORT_LISTENER;
1.73 markus 2104: }
2105:
1.113 markus 2106: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2107: error("Forward host name too long.");
2108: return success;
2109: }
1.25 markus 2110:
1.73 markus 2111: /* XXX listen_address is currently ignored */
1.28 markus 2112: /*
1.35 markus 2113: * getaddrinfo returns a loopback address if the hostname is
2114: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2115: */
1.35 markus 2116: memset(&hints, 0, sizeof(hints));
2117: hints.ai_family = IPv4or6;
2118: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2119: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2120: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2121: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2122: packet_disconnect("getaddrinfo: fatal error");
2123:
2124: for (ai = aitop; ai; ai = ai->ai_next) {
2125: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2126: continue;
2127: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2128: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 2129: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 2130: continue;
2131: }
2132: /* Create a port to listen for the host. */
2133: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2134: if (sock < 0) {
2135: /* this is no error since kernel may not support ipv6 */
2136: verbose("socket: %.100s", strerror(errno));
2137: continue;
2138: }
2139: /*
2140: * Set socket options. We would like the socket to disappear
2141: * as soon as it has been closed for whatever reason.
2142: */
2143: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2144: linger.l_onoff = 1;
2145: linger.l_linger = 5;
2146: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2147: debug("Local forwarding listening on %s port %s.", ntop, strport);
2148:
2149: /* Bind the socket to the address. */
2150: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2151: /* address can be in use ipv6 address is already bound */
2152: verbose("bind: %.100s", strerror(errno));
2153: close(sock);
2154: continue;
2155: }
2156: /* Start listening for connections on the socket. */
2157: if (listen(sock, 5) < 0) {
2158: error("listen: %.100s", strerror(errno));
2159: close(sock);
2160: continue;
2161: }
2162: /* Allocate a channel number for the socket. */
1.121 markus 2163: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2164: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2165: 0, xstrdup("port listener"), 1);
1.113 markus 2166: if (c == NULL) {
2167: error("channel_request_forwarding: channel_new failed");
2168: close(sock);
2169: continue;
2170: }
2171: strlcpy(c->path, host, sizeof(c->path));
2172: c->host_port = port_to_connect;
2173: c->listening_port = listen_port;
1.35 markus 2174: success = 1;
2175: }
2176: if (success == 0)
1.87 markus 2177: error("channel_request_forwarding: cannot listen to port: %d",
2178: listen_port);
1.35 markus 2179: freeaddrinfo(aitop);
1.87 markus 2180: return success;
1.25 markus 2181: }
1.1 deraadt 2182:
1.27 markus 2183: /*
2184: * Initiate forwarding of connections to port "port" on remote host through
2185: * the secure channel to host:port from local side.
2186: */
1.1 deraadt 2187:
1.49 markus 2188: void
1.73 markus 2189: channel_request_remote_forwarding(u_short listen_port,
2190: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2191: {
1.153 markus 2192: int type, success = 0;
1.73 markus 2193:
1.25 markus 2194: /* Record locally that connection to this host/port is permitted. */
2195: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2196: fatal("channel_request_remote_forwarding: too many forwards");
2197:
2198: /* Send the forward request to the remote side. */
1.44 markus 2199: if (compat20) {
2200: const char *address_to_bind = "0.0.0.0";
2201: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2202: packet_put_cstring("tcpip-forward");
2203: packet_put_char(0); /* boolean: want reply */
2204: packet_put_cstring(address_to_bind);
2205: packet_put_int(listen_port);
1.73 markus 2206: packet_send();
2207: packet_write_wait();
2208: /* Assume that server accepts the request */
2209: success = 1;
1.44 markus 2210: } else {
2211: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2212: packet_put_int(listen_port);
2213: packet_put_cstring(host_to_connect);
1.44 markus 2214: packet_put_int(port_to_connect);
2215: packet_send();
2216: packet_write_wait();
1.73 markus 2217:
2218: /* Wait for response from the remote side. */
1.153 markus 2219: type = packet_read();
1.73 markus 2220: switch (type) {
2221: case SSH_SMSG_SUCCESS:
2222: success = 1;
2223: break;
2224: case SSH_SMSG_FAILURE:
2225: log("Warning: Server denied remote port forwarding.");
2226: break;
2227: default:
2228: /* Unknown packet */
2229: packet_disconnect("Protocol error for port forward request:"
2230: "received packet type %d.", type);
2231: }
2232: }
2233: if (success) {
2234: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2235: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2236: permitted_opens[num_permitted_opens].listen_port = listen_port;
2237: num_permitted_opens++;
1.44 markus 2238: }
1.1 deraadt 2239: }
2240:
1.27 markus 2241: /*
2242: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2243: * listening for the port, and sends back a success reply (or disconnect
2244: * message if there was an error). This never returns if there was an error.
2245: */
1.1 deraadt 2246:
1.49 markus 2247: void
1.56 markus 2248: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2249: {
1.31 markus 2250: u_short port, host_port;
1.25 markus 2251: char *hostname;
1.1 deraadt 2252:
1.25 markus 2253: /* Get arguments from the packet. */
2254: port = packet_get_int();
2255: hostname = packet_get_string(NULL);
2256: host_port = packet_get_int();
2257:
1.27 markus 2258: /*
2259: * Check that an unprivileged user is not trying to forward a
2260: * privileged port.
2261: */
1.25 markus 2262: if (port < IPPORT_RESERVED && !is_root)
2263: packet_disconnect("Requested forwarding of port %d but user is not root.",
2264: port);
1.73 markus 2265: /* Initiate forwarding */
1.56 markus 2266: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2267:
2268: /* Free the argument string. */
2269: xfree(hostname);
1.1 deraadt 2270: }
2271:
1.99 markus 2272: /*
2273: * Permits opening to any host/port if permitted_opens[] is empty. This is
2274: * usually called by the server, because the user could connect to any port
2275: * anyway, and the server has no way to know but to trust the client anyway.
2276: */
2277: void
1.142 itojun 2278: channel_permit_all_opens(void)
1.99 markus 2279: {
2280: if (num_permitted_opens == 0)
2281: all_opens_permitted = 1;
2282: }
2283:
1.101 markus 2284: void
1.99 markus 2285: channel_add_permitted_opens(char *host, int port)
2286: {
2287: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2288: fatal("channel_request_remote_forwarding: too many forwards");
2289: debug("allow port forwarding to host %s port %d", host, port);
2290:
2291: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2292: permitted_opens[num_permitted_opens].port_to_connect = port;
2293: num_permitted_opens++;
2294:
2295: all_opens_permitted = 0;
2296: }
2297:
1.101 markus 2298: void
1.99 markus 2299: channel_clear_permitted_opens(void)
2300: {
2301: int i;
2302:
2303: for (i = 0; i < num_permitted_opens; i++)
2304: xfree(permitted_opens[i].host_to_connect);
2305: num_permitted_opens = 0;
2306:
2307: }
2308:
2309:
2310: /* return socket to remote host, port */
1.127 itojun 2311: static int
1.99 markus 2312: connect_to(const char *host, u_short port)
1.41 markus 2313: {
2314: struct addrinfo hints, *ai, *aitop;
2315: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2316: int gaierr;
2317: int sock = -1;
2318:
2319: memset(&hints, 0, sizeof(hints));
2320: hints.ai_family = IPv4or6;
2321: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2322: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2323: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2324: error("connect_to %.100s: unknown host (%s)", host,
2325: gai_strerror(gaierr));
1.41 markus 2326: return -1;
2327: }
2328: for (ai = aitop; ai; ai = ai->ai_next) {
2329: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2330: continue;
2331: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2332: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2333: error("connect_to: getnameinfo failed");
1.41 markus 2334: continue;
2335: }
2336: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2337: if (sock < 0) {
2338: error("socket: %.100s", strerror(errno));
2339: continue;
2340: }
1.80 markus 2341: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2342: fatal("connect_to: F_SETFL: %s", strerror(errno));
2343: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2344: errno != EINPROGRESS) {
1.99 markus 2345: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2346: strerror(errno));
2347: close(sock);
1.89 stevesk 2348: continue; /* fail -- try next */
1.41 markus 2349: }
2350: break; /* success */
2351:
2352: }
2353: freeaddrinfo(aitop);
2354: if (!ai) {
1.99 markus 2355: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2356: return -1;
2357: }
2358: /* success */
2359: return sock;
2360: }
1.99 markus 2361:
1.73 markus 2362: int
1.130 stevesk 2363: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2364: {
2365: int i;
1.99 markus 2366:
1.73 markus 2367: for (i = 0; i < num_permitted_opens; i++)
2368: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2369: return connect_to(
1.73 markus 2370: permitted_opens[i].host_to_connect,
2371: permitted_opens[i].port_to_connect);
1.74 markus 2372: error("WARNING: Server requests forwarding for unknown listen_port %d",
2373: listen_port);
1.73 markus 2374: return -1;
2375: }
2376:
1.99 markus 2377: /* Check if connecting to that port is permitted and connect. */
2378: int
2379: channel_connect_to(const char *host, u_short port)
2380: {
2381: int i, permit;
2382:
2383: permit = all_opens_permitted;
2384: if (!permit) {
2385: for (i = 0; i < num_permitted_opens; i++)
2386: if (permitted_opens[i].port_to_connect == port &&
2387: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2388: permit = 1;
2389:
2390: }
2391: if (!permit) {
2392: log("Received request to connect to host %.100s port %d, "
2393: "but the request was denied.", host, port);
2394: return -1;
2395: }
2396: return connect_to(host, port);
2397: }
2398:
1.121 markus 2399: /* -- X11 forwarding */
1.1 deraadt 2400:
1.27 markus 2401: /*
2402: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2403: * Returns a suitable display number for the DISPLAY variable, or -1 if
2404: * an error occurs.
1.27 markus 2405: */
1.141 stevesk 2406: int
1.149 markus 2407: x11_create_display_inet(int x11_display_offset, int gateway_ports,
2408: int single_connection)
1.1 deraadt 2409: {
1.149 markus 2410: Channel *nc = NULL;
1.31 markus 2411: int display_number, sock;
2412: u_short port;
1.35 markus 2413: struct addrinfo hints, *ai, *aitop;
2414: char strport[NI_MAXSERV];
2415: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2416:
1.33 markus 2417: for (display_number = x11_display_offset;
1.148 deraadt 2418: display_number < MAX_DISPLAYS;
2419: display_number++) {
1.25 markus 2420: port = 6000 + display_number;
1.35 markus 2421: memset(&hints, 0, sizeof(hints));
2422: hints.ai_family = IPv4or6;
1.141 stevesk 2423: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1.35 markus 2424: hints.ai_socktype = SOCK_STREAM;
2425: snprintf(strport, sizeof strport, "%d", port);
2426: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2427: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2428: return -1;
1.25 markus 2429: }
1.35 markus 2430: for (ai = aitop; ai; ai = ai->ai_next) {
2431: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2432: continue;
2433: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2434: if (sock < 0) {
2435: error("socket: %.100s", strerror(errno));
1.141 stevesk 2436: return -1;
1.35 markus 2437: }
2438: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2439: debug("bind port %d: %.100s", port, strerror(errno));
2440: close(sock);
2441: for (n = 0; n < num_socks; n++) {
2442: close(socks[n]);
2443: }
2444: num_socks = 0;
2445: break;
2446: }
2447: socks[num_socks++] = sock;
2448: if (num_socks == NUM_SOCKS)
2449: break;
1.25 markus 2450: }
1.83 stevesk 2451: freeaddrinfo(aitop);
1.35 markus 2452: if (num_socks > 0)
2453: break;
1.25 markus 2454: }
2455: if (display_number >= MAX_DISPLAYS) {
2456: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2457: return -1;
1.25 markus 2458: }
2459: /* Start listening for connections on the socket. */
1.35 markus 2460: for (n = 0; n < num_socks; n++) {
2461: sock = socks[n];
2462: if (listen(sock, 5) < 0) {
2463: error("listen: %.100s", strerror(errno));
2464: close(sock);
1.141 stevesk 2465: return -1;
1.35 markus 2466: }
1.25 markus 2467: }
1.35 markus 2468:
2469: /* Allocate a channel for each socket. */
2470: for (n = 0; n < num_socks; n++) {
2471: sock = socks[n];
1.149 markus 2472: nc = channel_new("x11 listener",
1.51 markus 2473: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2474: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2475: 0, xstrdup("X11 inet listener"), 1);
1.149 markus 2476: if (nc != NULL)
2477: nc->single_connection = single_connection;
1.35 markus 2478: }
1.1 deraadt 2479:
1.141 stevesk 2480: /* Return the display number for the DISPLAY environment variable. */
2481: return display_number;
1.1 deraadt 2482: }
2483:
1.127 itojun 2484: static int
1.77 markus 2485: connect_local_xsocket(u_int dnr)
1.1 deraadt 2486: {
1.25 markus 2487: int sock;
2488: struct sockaddr_un addr;
2489:
1.147 stevesk 2490: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2491: if (sock < 0)
2492: error("socket: %.100s", strerror(errno));
2493: memset(&addr, 0, sizeof(addr));
2494: addr.sun_family = AF_UNIX;
2495: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2496: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2497: return sock;
2498: close(sock);
1.25 markus 2499: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2500: return -1;
1.1 deraadt 2501: }
2502:
1.51 markus 2503: int
2504: x11_connect_display(void)
1.1 deraadt 2505: {
1.146 stevesk 2506: int display_number, sock = 0, on = 1;
1.25 markus 2507: const char *display;
1.51 markus 2508: char buf[1024], *cp;
1.35 markus 2509: struct addrinfo hints, *ai, *aitop;
2510: char strport[NI_MAXSERV];
2511: int gaierr;
1.25 markus 2512:
2513: /* Try to open a socket for the local X server. */
2514: display = getenv("DISPLAY");
2515: if (!display) {
2516: error("DISPLAY not set.");
1.51 markus 2517: return -1;
1.25 markus 2518: }
1.27 markus 2519: /*
2520: * Now we decode the value of the DISPLAY variable and make a
2521: * connection to the real X server.
2522: */
2523:
2524: /*
2525: * Check if it is a unix domain socket. Unix domain displays are in
2526: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2527: */
1.25 markus 2528: if (strncmp(display, "unix:", 5) == 0 ||
2529: display[0] == ':') {
2530: /* Connect to the unix domain socket. */
2531: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2532: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2533: display);
1.51 markus 2534: return -1;
1.25 markus 2535: }
2536: /* Create a socket. */
2537: sock = connect_local_xsocket(display_number);
2538: if (sock < 0)
1.51 markus 2539: return -1;
1.25 markus 2540:
2541: /* OK, we now have a connection to the display. */
1.51 markus 2542: return sock;
1.25 markus 2543: }
1.27 markus 2544: /*
2545: * Connect to an inet socket. The DISPLAY value is supposedly
2546: * hostname:d[.s], where hostname may also be numeric IP address.
2547: */
1.145 stevesk 2548: strlcpy(buf, display, sizeof(buf));
1.25 markus 2549: cp = strchr(buf, ':');
2550: if (!cp) {
2551: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2552: return -1;
1.25 markus 2553: }
2554: *cp = 0;
1.27 markus 2555: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2556: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2557: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2558: display);
1.51 markus 2559: return -1;
1.25 markus 2560: }
1.35 markus 2561:
2562: /* Look up the host address */
2563: memset(&hints, 0, sizeof(hints));
2564: hints.ai_family = IPv4or6;
2565: hints.ai_socktype = SOCK_STREAM;
2566: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2567: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2568: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2569: return -1;
1.25 markus 2570: }
1.35 markus 2571: for (ai = aitop; ai; ai = ai->ai_next) {
2572: /* Create a socket. */
2573: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2574: if (sock < 0) {
2575: debug("socket: %.100s", strerror(errno));
1.41 markus 2576: continue;
2577: }
2578: /* Connect it to the display. */
2579: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2580: debug("connect %.100s port %d: %.100s", buf,
2581: 6000 + display_number, strerror(errno));
2582: close(sock);
2583: continue;
2584: }
2585: /* Success */
2586: break;
1.35 markus 2587: }
2588: freeaddrinfo(aitop);
2589: if (!ai) {
1.49 markus 2590: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2591: strerror(errno));
1.51 markus 2592: return -1;
1.25 markus 2593: }
1.146 stevesk 2594: if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on) == -1)
2595: error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
1.51 markus 2596: return sock;
2597: }
2598:
2599: /*
2600: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2601: * the remote channel number. We should do whatever we want, and respond
2602: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2603: */
2604:
2605: void
1.154 markus 2606: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2607: {
1.113 markus 2608: Channel *c = NULL;
2609: int remote_id, sock = 0;
1.51 markus 2610: char *remote_host;
1.25 markus 2611:
1.113 markus 2612: debug("Received X11 open request.");
1.51 markus 2613:
1.113 markus 2614: remote_id = packet_get_int();
1.121 markus 2615:
2616: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2617: remote_host = packet_get_string(NULL);
1.51 markus 2618: } else {
2619: remote_host = xstrdup("unknown (remote did not supply name)");
2620: }
1.152 markus 2621: packet_check_eom();
1.25 markus 2622:
1.51 markus 2623: /* Obtain a connection to the real X display. */
2624: sock = x11_connect_display();
1.113 markus 2625: if (sock != -1) {
2626: /* Allocate a channel for this connection. */
2627: c = channel_new("connected x11 socket",
2628: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2629: remote_host, 1);
2630: if (c == NULL) {
2631: error("x11_input_open: channel_new failed");
2632: close(sock);
2633: } else {
2634: c->remote_id = remote_id;
1.133 markus 2635: c->force_drain = 1;
1.113 markus 2636: }
2637: }
2638: if (c == NULL) {
1.51 markus 2639: /* Send refusal to the remote host. */
2640: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2641: packet_put_int(remote_id);
1.51 markus 2642: } else {
2643: /* Send a confirmation to the remote host. */
2644: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2645: packet_put_int(remote_id);
2646: packet_put_int(c->self);
1.51 markus 2647: }
1.113 markus 2648: packet_send();
1.72 markus 2649: }
2650:
2651: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2652: void
1.154 markus 2653: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2654: {
2655: int rchan = packet_get_int();
1.143 deraadt 2656: switch (type) {
1.72 markus 2657: case SSH_SMSG_AGENT_OPEN:
2658: error("Warning: ssh server tried agent forwarding.");
2659: break;
2660: case SSH_SMSG_X11_OPEN:
2661: error("Warning: ssh server tried X11 forwarding.");
2662: break;
2663: default:
1.154 markus 2664: error("deny_input_open: type %d", type);
1.72 markus 2665: break;
2666: }
2667: error("Warning: this is probably a break in attempt by a malicious server.");
2668: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2669: packet_put_int(rchan);
2670: packet_send();
1.1 deraadt 2671: }
2672:
1.27 markus 2673: /*
2674: * Requests forwarding of X11 connections, generates fake authentication
2675: * data, and enables authentication spoofing.
1.121 markus 2676: * This should be called in the client only.
1.27 markus 2677: */
1.49 markus 2678: void
1.51 markus 2679: x11_request_forwarding_with_spoofing(int client_session_id,
2680: const char *proto, const char *data)
1.1 deraadt 2681: {
1.77 markus 2682: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2683: u_int i, value, len;
1.25 markus 2684: char *new_data;
2685: int screen_number;
2686: const char *cp;
2687: u_int32_t rand = 0;
2688:
2689: cp = getenv("DISPLAY");
2690: if (cp)
2691: cp = strchr(cp, ':');
2692: if (cp)
2693: cp = strchr(cp, '.');
2694: if (cp)
2695: screen_number = atoi(cp + 1);
2696: else
2697: screen_number = 0;
2698:
2699: /* Save protocol name. */
2700: x11_saved_proto = xstrdup(proto);
2701:
1.27 markus 2702: /*
2703: * Extract real authentication data and generate fake data of the
2704: * same length.
2705: */
1.25 markus 2706: x11_saved_data = xmalloc(data_len);
2707: x11_fake_data = xmalloc(data_len);
2708: for (i = 0; i < data_len; i++) {
2709: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2710: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2711: if (i % 4 == 0)
2712: rand = arc4random();
2713: x11_saved_data[i] = value;
2714: x11_fake_data[i] = rand & 0xff;
2715: rand >>= 8;
2716: }
2717: x11_saved_data_len = data_len;
2718: x11_fake_data_len = data_len;
2719:
2720: /* Convert the fake data into hex. */
1.90 markus 2721: len = 2 * data_len + 1;
2722: new_data = xmalloc(len);
1.25 markus 2723: for (i = 0; i < data_len; i++)
1.90 markus 2724: snprintf(new_data + 2 * i, len - 2 * i,
2725: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2726:
2727: /* Send the request packet. */
1.51 markus 2728: if (compat20) {
2729: channel_request_start(client_session_id, "x11-req", 0);
2730: packet_put_char(0); /* XXX bool single connection */
2731: } else {
2732: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2733: }
2734: packet_put_cstring(proto);
2735: packet_put_cstring(new_data);
1.25 markus 2736: packet_put_int(screen_number);
2737: packet_send();
2738: packet_write_wait();
2739: xfree(new_data);
1.1 deraadt 2740: }
2741:
1.121 markus 2742:
2743: /* -- agent forwarding */
2744:
1.1 deraadt 2745: /* Sends a message to the server to request authentication fd forwarding. */
2746:
1.49 markus 2747: void
1.142 itojun 2748: auth_request_forwarding(void)
1.1 deraadt 2749: {
1.25 markus 2750: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2751: packet_send();
2752: packet_write_wait();
1.1 deraadt 2753: }
2754:
1.27 markus 2755: /*
2756: * Returns the name of the forwarded authentication socket. Returns NULL if
2757: * there is no forwarded authentication socket. The returned value points to
2758: * a static buffer.
2759: */
1.1 deraadt 2760:
1.25 markus 2761: char *
1.142 itojun 2762: auth_get_socket_name(void)
1.1 deraadt 2763: {
1.121 markus 2764: return auth_sock_name;
1.1 deraadt 2765: }
2766:
1.12 markus 2767: /* removes the agent forwarding socket */
2768:
1.49 markus 2769: void
1.123 markus 2770: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2771: {
1.123 markus 2772: struct passwd *pw = _pw;
2773:
1.122 markus 2774: if (auth_sock_name) {
1.123 markus 2775: temporarily_use_uid(pw);
1.122 markus 2776: unlink(auth_sock_name);
2777: rmdir(auth_sock_dir);
2778: auth_sock_name = NULL;
1.123 markus 2779: restore_uid();
1.122 markus 2780: }
1.12 markus 2781: }
2782:
1.27 markus 2783: /*
1.59 markus 2784: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2785: * This starts forwarding authentication requests.
2786: */
1.1 deraadt 2787:
1.59 markus 2788: int
1.25 markus 2789: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2790: {
1.113 markus 2791: Channel *nc;
2792: int sock;
1.25 markus 2793: struct sockaddr_un sunaddr;
2794:
1.121 markus 2795: if (auth_get_socket_name() != NULL) {
2796: error("authentication forwarding requested twice.");
2797: return 0;
2798: }
1.25 markus 2799:
2800: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2801: temporarily_use_uid(pw);
1.25 markus 2802:
2803: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2804: auth_sock_name = xmalloc(MAXPATHLEN);
2805: auth_sock_dir = xmalloc(MAXPATHLEN);
2806: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2807:
2808: /* Create private directory for socket */
1.121 markus 2809: if (mkdtemp(auth_sock_dir) == NULL) {
2810: packet_send_debug("Agent forwarding disabled: "
2811: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2812: restore_uid();
1.121 markus 2813: xfree(auth_sock_name);
2814: xfree(auth_sock_dir);
2815: auth_sock_name = NULL;
2816: auth_sock_dir = NULL;
1.59 markus 2817: return 0;
2818: }
1.121 markus 2819: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2820: auth_sock_dir, (int) getpid());
1.25 markus 2821:
1.122 markus 2822: /* delete agent socket on fatal() */
1.123 markus 2823: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2824:
1.25 markus 2825: /* Create the socket. */
2826: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2827: if (sock < 0)
2828: packet_disconnect("socket: %.100s", strerror(errno));
2829:
2830: /* Bind it to the name. */
2831: memset(&sunaddr, 0, sizeof(sunaddr));
2832: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2833: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2834:
2835: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2836: packet_disconnect("bind: %.100s", strerror(errno));
2837:
2838: /* Restore the privileged uid. */
2839: restore_uid();
2840:
2841: /* Start listening on the socket. */
2842: if (listen(sock, 5) < 0)
2843: packet_disconnect("listen: %.100s", strerror(errno));
2844:
2845: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2846: nc = channel_new("auth socket",
1.73 markus 2847: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2848: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2849: 0, xstrdup("auth socket"), 1);
1.113 markus 2850: if (nc == NULL) {
2851: error("auth_input_request_forwarding: channel_new failed");
1.123 markus 2852: auth_sock_cleanup_proc(pw);
1.124 markus 2853: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
1.113 markus 2854: close(sock);
2855: return 0;
2856: }
1.121 markus 2857: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2858: return 1;
1.1 deraadt 2859: }
2860:
2861: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2862:
1.49 markus 2863: void
1.154 markus 2864: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2865: {
1.113 markus 2866: Channel *c = NULL;
2867: int remote_id, sock;
1.121 markus 2868: char *name;
1.41 markus 2869:
1.25 markus 2870: /* Read the remote channel number from the message. */
1.113 markus 2871: remote_id = packet_get_int();
1.152 markus 2872: packet_check_eom();
1.25 markus 2873:
1.27 markus 2874: /*
2875: * Get a connection to the local authentication agent (this may again
2876: * get forwarded).
2877: */
1.25 markus 2878: sock = ssh_get_authentication_socket();
2879:
1.27 markus 2880: /*
2881: * If we could not connect the agent, send an error message back to
2882: * the server. This should never happen unless the agent dies,
2883: * because authentication forwarding is only enabled if we have an
2884: * agent.
2885: */
1.113 markus 2886: if (sock >= 0) {
1.121 markus 2887: name = xstrdup("authentication agent connection");
2888: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2889: -1, 0, 0, 0, name, 1);
1.113 markus 2890: if (c == NULL) {
2891: error("auth_input_open_request: channel_new failed");
1.121 markus 2892: xfree(name);
1.113 markus 2893: close(sock);
2894: } else {
2895: c->remote_id = remote_id;
1.133 markus 2896: c->force_drain = 1;
1.113 markus 2897: }
2898: }
2899: if (c == NULL) {
1.25 markus 2900: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2901: packet_put_int(remote_id);
2902: } else {
2903: /* Send a confirmation to the remote host. */
2904: debug("Forwarding authentication connection.");
2905: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2906: packet_put_int(remote_id);
2907: packet_put_int(c->self);
1.25 markus 2908: }
2909: packet_send();
1.1 deraadt 2910: }
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