Annotation of src/usr.bin/ssh/channels.c, Revision 1.166
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"
1.166 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.165 2002/02/03 17:58:21 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
49: #include "uidswap.h"
1.82 markus 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.82 markus 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.147 stevesk 57: #include "pathnames.h"
1.44 markus 58:
1.1 deraadt 59:
1.121 markus 60: /* -- channel core */
1.12 markus 61:
1.27 markus 62: /*
63: * Pointer to an array containing all allocated channels. The array is
64: * dynamically extended as needed.
65: */
1.113 markus 66: static Channel **channels = NULL;
1.1 deraadt 67:
1.27 markus 68: /*
69: * Size of the channel array. All slots of the array must always be
1.113 markus 70: * initialized (at least the type field); unused slots set to NULL
1.27 markus 71: */
1.1 deraadt 72: static int channels_alloc = 0;
73:
1.27 markus 74: /*
75: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 76: * updated in channel_new.
1.27 markus 77: */
1.84 markus 78: static int channel_max_fd = 0;
1.1 deraadt 79:
80:
1.121 markus 81: /* -- tcp forwarding */
1.1 deraadt 82:
1.27 markus 83: /*
84: * Data structure for storing which hosts are permitted for forward requests.
85: * The local sides of any remote forwards are stored in this array to prevent
86: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
87: * network (which might be behind a firewall).
88: */
1.25 markus 89: typedef struct {
1.41 markus 90: char *host_to_connect; /* Connect to 'host'. */
91: u_short port_to_connect; /* Connect to 'port'. */
92: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 93: } ForwardPermission;
94:
95: /* List of all permitted host/port pairs to connect. */
96: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 97:
1.1 deraadt 98: /* Number of permitted host/port pairs in the array. */
99: static int num_permitted_opens = 0;
1.27 markus 100: /*
101: * If this is true, all opens are permitted. This is the case on the server
102: * on which we have to trust the client anyway, and the user could do
103: * anything after logging in anyway.
104: */
1.1 deraadt 105: static int all_opens_permitted = 0;
106:
1.121 markus 107:
108: /* -- X11 forwarding */
109:
110: /* Maximum number of fake X11 displays to try. */
111: #define MAX_DISPLAYS 1000
112:
113: /* Saved X11 authentication protocol name. */
114: static char *x11_saved_proto = NULL;
115:
116: /* Saved X11 authentication data. This is the real data. */
117: static char *x11_saved_data = NULL;
118: static u_int x11_saved_data_len = 0;
119:
120: /*
121: * Fake X11 authentication data. This is what the server will be sending us;
122: * we should replace any occurrences of this by the real data.
123: */
124: static char *x11_fake_data = NULL;
125: static u_int x11_fake_data_len;
126:
127:
128: /* -- agent forwarding */
129:
130: #define NUM_SOCKS 10
131:
132: /* Name and directory of socket for authentication agent forwarding. */
133: static char *auth_sock_name = NULL;
134: static char *auth_sock_dir = NULL;
135:
1.82 markus 136: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 137: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 138:
1.121 markus 139: /* helper */
1.127 itojun 140: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 141:
1.121 markus 142: /* -- channel core */
1.41 markus 143:
144: Channel *
145: channel_lookup(int id)
146: {
147: Channel *c;
1.113 markus 148:
1.63 provos 149: if (id < 0 || id > channels_alloc) {
1.41 markus 150: log("channel_lookup: %d: bad id", id);
151: return NULL;
152: }
1.113 markus 153: c = channels[id];
154: if (c == NULL) {
1.41 markus 155: log("channel_lookup: %d: bad id: channel free", id);
156: return NULL;
157: }
158: return c;
1.55 markus 159: }
160:
1.27 markus 161: /*
1.55 markus 162: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 163: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 164: */
1.1 deraadt 165:
1.127 itojun 166: static void
1.71 markus 167: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
168: int extusage, int nonblock)
1.1 deraadt 169: {
1.25 markus 170: /* Update the maximum file descriptor value. */
1.84 markus 171: channel_max_fd = MAX(channel_max_fd, rfd);
172: channel_max_fd = MAX(channel_max_fd, wfd);
173: channel_max_fd = MAX(channel_max_fd, efd);
174:
1.27 markus 175: /* XXX set close-on-exec -markus */
1.55 markus 176:
1.52 markus 177: c->rfd = rfd;
178: c->wfd = wfd;
179: c->sock = (rfd == wfd) ? rfd : -1;
180: c->efd = efd;
181: c->extended_usage = extusage;
1.71 markus 182:
1.91 markus 183: /* XXX ugly hack: nonblock is only set by the server */
184: if (nonblock && isatty(c->rfd)) {
1.94 markus 185: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 186: c->isatty = 1;
187: if (!isatty(c->wfd)) {
1.94 markus 188: error("channel %d: wfd %d is not a tty?",
1.91 markus 189: c->self, c->wfd);
190: }
191: } else {
192: c->isatty = 0;
193: }
194:
1.71 markus 195: /* enable nonblocking mode */
196: if (nonblock) {
197: if (rfd != -1)
198: set_nonblock(rfd);
199: if (wfd != -1)
200: set_nonblock(wfd);
201: if (efd != -1)
202: set_nonblock(efd);
203: }
1.52 markus 204: }
205:
206: /*
207: * Allocate a new channel object and set its type and socket. This will cause
208: * remote_name to be freed.
209: */
210:
1.113 markus 211: Channel *
1.52 markus 212: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 213: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 214: {
215: int i, found;
216: Channel *c;
1.25 markus 217:
218: /* Do initial allocation if this is the first call. */
219: if (channels_alloc == 0) {
220: channels_alloc = 10;
1.113 markus 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.113 markus 223: channels[i] = NULL;
1.126 markus 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.113 markus 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 244: memset(c, 0, sizeof(Channel));
1.25 markus 245: buffer_init(&c->input);
246: buffer_init(&c->output);
1.41 markus 247: buffer_init(&c->extended);
1.159 markus 248: c->ostate = CHAN_OUTPUT_OPEN;
249: c->istate = CHAN_INPUT_OPEN;
250: c->flags = 0;
1.71 markus 251: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 252: c->self = found;
253: c->type = type;
1.41 markus 254: c->ctype = ctype;
1.51 markus 255: c->local_window = window;
256: c->local_window_max = window;
257: c->local_consumed = 0;
258: c->local_maxpacket = maxpack;
1.25 markus 259: c->remote_id = -1;
260: c->remote_name = remote_name;
1.41 markus 261: c->remote_window = 0;
262: c->remote_maxpacket = 0;
1.133 markus 263: c->force_drain = 0;
1.149 markus 264: c->single_connection = 0;
1.131 markus 265: c->detach_user = NULL;
1.165 markus 266: c->confirm = NULL;
1.65 markus 267: c->input_filter = NULL;
1.25 markus 268: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 269: return c;
1.1 deraadt 270: }
1.52 markus 271:
1.132 markus 272: static int
273: channel_find_maxfd(void)
274: {
275: int i, max = 0;
276: Channel *c;
277:
278: for (i = 0; i < channels_alloc; i++) {
279: c = channels[i];
280: if (c != NULL) {
281: max = MAX(max, c->rfd);
282: max = MAX(max, c->wfd);
283: max = MAX(max, c->efd);
284: }
285: }
286: return max;
287: }
288:
289: int
290: channel_close_fd(int *fdp)
291: {
292: int ret = 0, fd = *fdp;
293:
294: if (fd != -1) {
295: ret = close(fd);
296: *fdp = -1;
297: if (fd == channel_max_fd)
298: channel_max_fd = channel_find_maxfd();
299: }
300: return ret;
301: }
302:
1.52 markus 303: /* Close all channel fd/socket. */
304:
1.127 itojun 305: static void
1.52 markus 306: channel_close_fds(Channel *c)
307: {
1.118 markus 308: debug3("channel_close_fds: channel %d: r %d w %d e %d",
309: c->self, c->rfd, c->wfd, c->efd);
310:
1.132 markus 311: channel_close_fd(&c->sock);
312: channel_close_fd(&c->rfd);
313: channel_close_fd(&c->wfd);
314: channel_close_fd(&c->efd);
1.121 markus 315: }
316:
317: /* Free the channel and close its fd/socket. */
318:
319: void
320: channel_free(Channel *c)
321: {
322: char *s;
323: int i, n;
324:
325: for (n = 0, i = 0; i < channels_alloc; i++)
326: if (channels[i])
327: n++;
328: debug("channel_free: channel %d: %s, nchannels %d", c->self,
329: c->remote_name ? c->remote_name : "???", n);
330:
331: s = channel_open_message();
332: debug3("channel_free: status: %s", s);
333: xfree(s);
334:
335: if (c->sock != -1)
336: shutdown(c->sock, SHUT_RDWR);
337: channel_close_fds(c);
338: buffer_free(&c->input);
339: buffer_free(&c->output);
340: buffer_free(&c->extended);
341: if (c->remote_name) {
342: xfree(c->remote_name);
343: c->remote_name = NULL;
344: }
345: channels[c->self] = NULL;
346: xfree(c);
347: }
348:
349: void
1.126 markus 350: channel_free_all(void)
1.121 markus 351: {
352: int i;
353:
1.126 markus 354: for (i = 0; i < channels_alloc; i++)
355: if (channels[i] != NULL)
356: channel_free(channels[i]);
1.131 markus 357: }
358:
1.121 markus 359: /*
360: * Closes the sockets/fds of all channels. This is used to close extra file
361: * descriptors after a fork.
362: */
363:
364: void
1.142 itojun 365: channel_close_all(void)
1.121 markus 366: {
367: int i;
368:
369: for (i = 0; i < channels_alloc; i++)
370: if (channels[i] != NULL)
371: channel_close_fds(channels[i]);
372: }
373:
374: /*
1.131 markus 375: * Stop listening to channels.
376: */
377:
378: void
379: channel_stop_listening(void)
380: {
381: int i;
382: Channel *c;
383:
384: for (i = 0; i < channels_alloc; i++) {
385: c = channels[i];
386: if (c != NULL) {
387: switch (c->type) {
388: case SSH_CHANNEL_AUTH_SOCKET:
389: case SSH_CHANNEL_PORT_LISTENER:
390: case SSH_CHANNEL_RPORT_LISTENER:
391: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 392: channel_close_fd(&c->sock);
1.131 markus 393: channel_free(c);
394: break;
395: }
396: }
397: }
398: }
399:
400: /*
1.121 markus 401: * Returns true if no channel has too much buffered data, and false if one or
402: * more channel is overfull.
403: */
404:
405: int
1.142 itojun 406: channel_not_very_much_buffered_data(void)
1.121 markus 407: {
408: u_int i;
409: Channel *c;
410:
411: for (i = 0; i < channels_alloc; i++) {
412: c = channels[i];
413: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 414: #if 0
415: if (!compat20 &&
416: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 417: debug("channel %d: big input buffer %d",
418: c->self, buffer_len(&c->input));
419: return 0;
420: }
1.136 markus 421: #endif
1.121 markus 422: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 423: debug("channel %d: big output buffer %d > %d",
424: c->self, buffer_len(&c->output),
425: packet_get_maxsize());
1.121 markus 426: return 0;
427: }
428: }
429: }
430: return 1;
431: }
432:
433: /* Returns true if any channel is still open. */
434:
435: int
1.142 itojun 436: channel_still_open(void)
1.121 markus 437: {
438: int i;
439: Channel *c;
440:
441: for (i = 0; i < channels_alloc; i++) {
442: c = channels[i];
443: if (c == NULL)
444: continue;
445: switch (c->type) {
446: case SSH_CHANNEL_X11_LISTENER:
447: case SSH_CHANNEL_PORT_LISTENER:
448: case SSH_CHANNEL_RPORT_LISTENER:
449: case SSH_CHANNEL_CLOSED:
450: case SSH_CHANNEL_AUTH_SOCKET:
451: case SSH_CHANNEL_DYNAMIC:
452: case SSH_CHANNEL_CONNECTING:
453: case SSH_CHANNEL_ZOMBIE:
454: continue;
455: case SSH_CHANNEL_LARVAL:
456: if (!compat20)
457: fatal("cannot happen: SSH_CHANNEL_LARVAL");
458: continue;
459: case SSH_CHANNEL_OPENING:
460: case SSH_CHANNEL_OPEN:
461: case SSH_CHANNEL_X11_OPEN:
462: return 1;
463: case SSH_CHANNEL_INPUT_DRAINING:
464: case SSH_CHANNEL_OUTPUT_DRAINING:
465: if (!compat13)
466: fatal("cannot happen: OUT_DRAIN");
467: return 1;
468: default:
469: fatal("channel_still_open: bad channel type %d", c->type);
470: /* NOTREACHED */
471: }
472: }
473: return 0;
474: }
475:
476: /* Returns the id of an open channel suitable for keepaliving */
477:
478: int
1.142 itojun 479: channel_find_open(void)
1.121 markus 480: {
481: int i;
482: Channel *c;
483:
484: for (i = 0; i < channels_alloc; i++) {
485: c = channels[i];
486: if (c == NULL)
487: continue;
488: switch (c->type) {
489: case SSH_CHANNEL_CLOSED:
490: case SSH_CHANNEL_DYNAMIC:
491: case SSH_CHANNEL_X11_LISTENER:
492: case SSH_CHANNEL_PORT_LISTENER:
493: case SSH_CHANNEL_RPORT_LISTENER:
494: case SSH_CHANNEL_OPENING:
495: case SSH_CHANNEL_CONNECTING:
496: case SSH_CHANNEL_ZOMBIE:
497: continue;
498: case SSH_CHANNEL_LARVAL:
499: case SSH_CHANNEL_AUTH_SOCKET:
500: case SSH_CHANNEL_OPEN:
501: case SSH_CHANNEL_X11_OPEN:
502: return i;
503: case SSH_CHANNEL_INPUT_DRAINING:
504: case SSH_CHANNEL_OUTPUT_DRAINING:
505: if (!compat13)
506: fatal("cannot happen: OUT_DRAIN");
507: return i;
508: default:
509: fatal("channel_find_open: bad channel type %d", c->type);
510: /* NOTREACHED */
511: }
512: }
513: return -1;
514: }
515:
516:
517: /*
518: * Returns a message describing the currently open forwarded connections,
519: * suitable for sending to the client. The message contains crlf pairs for
520: * newlines.
521: */
522:
523: char *
1.142 itojun 524: channel_open_message(void)
1.121 markus 525: {
526: Buffer buffer;
527: Channel *c;
528: char buf[1024], *cp;
529: int i;
530:
531: buffer_init(&buffer);
532: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
533: buffer_append(&buffer, buf, strlen(buf));
534: for (i = 0; i < channels_alloc; i++) {
535: c = channels[i];
536: if (c == NULL)
537: continue;
538: switch (c->type) {
539: case SSH_CHANNEL_X11_LISTENER:
540: case SSH_CHANNEL_PORT_LISTENER:
541: case SSH_CHANNEL_RPORT_LISTENER:
542: case SSH_CHANNEL_CLOSED:
543: case SSH_CHANNEL_AUTH_SOCKET:
544: case SSH_CHANNEL_ZOMBIE:
545: continue;
546: case SSH_CHANNEL_LARVAL:
547: case SSH_CHANNEL_OPENING:
548: case SSH_CHANNEL_CONNECTING:
549: case SSH_CHANNEL_DYNAMIC:
550: case SSH_CHANNEL_OPEN:
551: case SSH_CHANNEL_X11_OPEN:
552: case SSH_CHANNEL_INPUT_DRAINING:
553: case SSH_CHANNEL_OUTPUT_DRAINING:
554: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
555: c->self, c->remote_name,
556: c->type, c->remote_id,
557: c->istate, buffer_len(&c->input),
558: c->ostate, buffer_len(&c->output),
559: c->rfd, c->wfd);
560: buffer_append(&buffer, buf, strlen(buf));
561: continue;
562: default:
563: fatal("channel_open_message: bad channel type %d", c->type);
564: /* NOTREACHED */
565: }
566: }
567: buffer_append(&buffer, "\0", 1);
568: cp = xstrdup(buffer_ptr(&buffer));
569: buffer_free(&buffer);
570: return cp;
571: }
572:
573: void
574: channel_send_open(int id)
575: {
576: Channel *c = channel_lookup(id);
577: if (c == NULL) {
578: log("channel_send_open: %d: bad id", id);
579: return;
580: }
581: debug("send channel open %d", id);
582: packet_start(SSH2_MSG_CHANNEL_OPEN);
583: packet_put_cstring(c->ctype);
584: packet_put_int(c->self);
585: packet_put_int(c->local_window);
586: packet_put_int(c->local_maxpacket);
587: packet_send();
588: }
589:
590: void
1.166 ! markus 591: channel_request_start(int local_id, char *service, int wantconfirm)
1.121 markus 592: {
1.166 ! markus 593: Channel *c = channel_lookup(local_id);
1.121 markus 594: if (c == NULL) {
1.166 ! markus 595: log("channel_request_start: %d: unknown channel id", local_id);
1.121 markus 596: return;
597: }
1.166 ! markus 598: debug("channel request %d: %s", local_id, service) ;
1.121 markus 599: packet_start(SSH2_MSG_CHANNEL_REQUEST);
600: packet_put_int(c->remote_id);
601: packet_put_cstring(service);
602: packet_put_char(wantconfirm);
603: }
604: void
1.165 markus 605: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 606: {
607: Channel *c = channel_lookup(id);
608: if (c == NULL) {
1.165 markus 609: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 610: return;
611: }
1.165 markus 612: c->confirm = fn;
1.121 markus 613: }
614: void
615: channel_register_cleanup(int id, channel_callback_fn *fn)
616: {
617: Channel *c = channel_lookup(id);
618: if (c == NULL) {
619: log("channel_register_cleanup: %d: bad id", id);
620: return;
621: }
1.131 markus 622: c->detach_user = fn;
1.121 markus 623: }
624: void
625: channel_cancel_cleanup(int id)
626: {
627: Channel *c = channel_lookup(id);
628: if (c == NULL) {
629: log("channel_cancel_cleanup: %d: bad id", id);
630: return;
1.52 markus 631: }
1.131 markus 632: c->detach_user = NULL;
1.121 markus 633: }
634: void
635: channel_register_filter(int id, channel_filter_fn *fn)
636: {
637: Channel *c = channel_lookup(id);
638: if (c == NULL) {
639: log("channel_register_filter: %d: bad id", id);
640: return;
1.52 markus 641: }
1.121 markus 642: c->input_filter = fn;
1.52 markus 643: }
644:
1.49 markus 645: void
1.121 markus 646: channel_set_fds(int id, int rfd, int wfd, int efd,
647: int extusage, int nonblock)
1.1 deraadt 648: {
1.121 markus 649: Channel *c = channel_lookup(id);
650: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
651: fatal("channel_activate for non-larval channel %d.", id);
652: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
653: c->type = SSH_CHANNEL_OPEN;
654: /* XXX window size? */
655: c->local_window = c->local_window_max = c->local_maxpacket * 2;
656: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
657: packet_put_int(c->remote_id);
658: packet_put_int(c->local_window);
659: packet_send();
1.1 deraadt 660: }
661:
1.27 markus 662: /*
1.41 markus 663: * 'channel_pre*' are called just before select() to add any bits relevant to
664: * channels in the select bitmasks.
665: */
666: /*
667: * 'channel_post*': perform any appropriate operations for channels which
668: * have events pending.
1.27 markus 669: */
1.41 markus 670: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
671: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
672: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
673:
1.127 itojun 674: static void
1.41 markus 675: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
676: {
677: FD_SET(c->sock, readset);
678: }
679:
1.127 itojun 680: static void
1.75 markus 681: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
682: {
683: debug3("channel %d: waiting for connection", c->self);
684: FD_SET(c->sock, writeset);
685: }
686:
1.127 itojun 687: static void
1.41 markus 688: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
689: {
690: if (buffer_len(&c->input) < packet_get_maxsize())
691: FD_SET(c->sock, readset);
692: if (buffer_len(&c->output) > 0)
693: FD_SET(c->sock, writeset);
694: }
1.1 deraadt 695:
1.127 itojun 696: static void
1.157 markus 697: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 698: {
1.157 markus 699: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 700:
1.44 markus 701: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 702: limit > 0 &&
703: buffer_len(&c->input) < limit)
1.44 markus 704: FD_SET(c->rfd, readset);
705: if (c->ostate == CHAN_OUTPUT_OPEN ||
706: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
707: if (buffer_len(&c->output) > 0) {
708: FD_SET(c->wfd, writeset);
709: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
710: chan_obuf_empty(c);
711: }
712: }
713: /** XXX check close conditions, too */
1.157 markus 714: if (compat20 && c->efd != -1) {
1.44 markus 715: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
716: buffer_len(&c->extended) > 0)
717: FD_SET(c->efd, writeset);
718: else if (c->extended_usage == CHAN_EXTENDED_READ &&
719: buffer_len(&c->extended) < c->remote_window)
720: FD_SET(c->efd, readset);
721: }
722: }
723:
1.127 itojun 724: static void
1.41 markus 725: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
726: {
727: if (buffer_len(&c->input) == 0) {
728: packet_start(SSH_MSG_CHANNEL_CLOSE);
729: packet_put_int(c->remote_id);
730: packet_send();
731: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 732: debug("channel %d: closing after input drain.", c->self);
1.41 markus 733: }
734: }
735:
1.127 itojun 736: static void
1.41 markus 737: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
738: {
739: if (buffer_len(&c->output) == 0)
1.113 markus 740: chan_mark_dead(c);
1.49 markus 741: else
1.41 markus 742: FD_SET(c->sock, writeset);
743: }
744:
745: /*
746: * This is a special state for X11 authentication spoofing. An opened X11
747: * connection (when authentication spoofing is being done) remains in this
748: * state until the first packet has been completely read. The authentication
749: * data in that packet is then substituted by the real data if it matches the
750: * fake data, and the channel is put into normal mode.
1.51 markus 751: * XXX All this happens at the client side.
1.121 markus 752: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 753: */
1.127 itojun 754: static int
1.121 markus 755: x11_open_helper(Buffer *b)
1.1 deraadt 756: {
1.77 markus 757: u_char *ucp;
758: u_int proto_len, data_len;
1.25 markus 759:
1.41 markus 760: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 761: if (buffer_len(b) < 12)
1.41 markus 762: return 0;
763:
764: /* Parse the lengths of variable-length fields. */
1.155 stevesk 765: ucp = buffer_ptr(b);
1.41 markus 766: if (ucp[0] == 0x42) { /* Byte order MSB first. */
767: proto_len = 256 * ucp[6] + ucp[7];
768: data_len = 256 * ucp[8] + ucp[9];
769: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
770: proto_len = ucp[6] + 256 * ucp[7];
771: data_len = ucp[8] + 256 * ucp[9];
772: } else {
773: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 774: ucp[0]);
1.41 markus 775: return -1;
776: }
777:
778: /* Check if the whole packet is in buffer. */
1.121 markus 779: if (buffer_len(b) <
1.41 markus 780: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
781: return 0;
782:
783: /* Check if authentication protocol matches. */
784: if (proto_len != strlen(x11_saved_proto) ||
785: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
786: debug("X11 connection uses different authentication protocol.");
787: return -1;
788: }
789: /* Check if authentication data matches our fake data. */
790: if (data_len != x11_fake_data_len ||
791: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
792: x11_fake_data, x11_fake_data_len) != 0) {
793: debug("X11 auth data does not match fake data.");
794: return -1;
795: }
796: /* Check fake data length */
797: if (x11_fake_data_len != x11_saved_data_len) {
798: error("X11 fake_data_len %d != saved_data_len %d",
799: x11_fake_data_len, x11_saved_data_len);
800: return -1;
801: }
802: /*
803: * Received authentication protocol and data match
804: * our fake data. Substitute the fake data with real
805: * data.
806: */
807: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
808: x11_saved_data, x11_saved_data_len);
809: return 1;
810: }
811:
1.127 itojun 812: static void
1.41 markus 813: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
814: {
1.121 markus 815: int ret = x11_open_helper(&c->output);
1.41 markus 816: if (ret == 1) {
817: /* Start normal processing for the channel. */
818: c->type = SSH_CHANNEL_OPEN;
1.47 markus 819: channel_pre_open_13(c, readset, writeset);
1.41 markus 820: } else if (ret == -1) {
821: /*
822: * We have received an X11 connection that has bad
823: * authentication information.
824: */
1.98 millert 825: log("X11 connection rejected because of wrong authentication.");
1.41 markus 826: buffer_clear(&c->input);
827: buffer_clear(&c->output);
1.132 markus 828: channel_close_fd(&c->sock);
1.41 markus 829: c->sock = -1;
830: c->type = SSH_CHANNEL_CLOSED;
831: packet_start(SSH_MSG_CHANNEL_CLOSE);
832: packet_put_int(c->remote_id);
833: packet_send();
834: }
835: }
1.25 markus 836:
1.127 itojun 837: static void
1.51 markus 838: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 839: {
1.121 markus 840: int ret = x11_open_helper(&c->output);
1.133 markus 841:
842: /* c->force_drain = 1; */
843:
1.41 markus 844: if (ret == 1) {
845: c->type = SSH_CHANNEL_OPEN;
1.157 markus 846: channel_pre_open(c, readset, writeset);
1.41 markus 847: } else if (ret == -1) {
1.156 markus 848: log("X11 connection rejected because of wrong authentication.");
1.41 markus 849: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 850: chan_read_failed(c);
851: buffer_clear(&c->input);
852: chan_ibuf_empty(c);
853: buffer_clear(&c->output);
854: /* for proto v1, the peer will send an IEOF */
855: if (compat20)
856: chan_write_failed(c);
857: else
858: c->type = SSH_CHANNEL_OPEN;
1.41 markus 859: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
860: }
861: }
1.25 markus 862:
1.104 markus 863: /* try to decode a socks4 header */
1.127 itojun 864: static int
1.104 markus 865: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 866: {
867: u_char *p, *host;
1.109 markus 868: int len, have, i, found;
1.148 deraadt 869: char username[256];
1.103 markus 870: struct {
871: u_int8_t version;
872: u_int8_t command;
873: u_int16_t dest_port;
1.104 markus 874: struct in_addr dest_addr;
1.103 markus 875: } s4_req, s4_rsp;
876:
1.104 markus 877: debug2("channel %d: decode socks4", c->self);
1.109 markus 878:
879: have = buffer_len(&c->input);
880: len = sizeof(s4_req);
881: if (have < len)
882: return 0;
883: p = buffer_ptr(&c->input);
884: for (found = 0, i = len; i < have; i++) {
885: if (p[i] == '\0') {
886: found = 1;
887: break;
888: }
889: if (i > 1024) {
890: /* the peer is probably sending garbage */
891: debug("channel %d: decode socks4: too long",
892: c->self);
893: return -1;
894: }
895: }
896: if (!found)
897: return 0;
1.103 markus 898: buffer_get(&c->input, (char *)&s4_req.version, 1);
899: buffer_get(&c->input, (char *)&s4_req.command, 1);
900: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 901: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 902: have = buffer_len(&c->input);
1.103 markus 903: p = buffer_ptr(&c->input);
904: len = strlen(p);
1.106 markus 905: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 906: if (len > have)
1.104 markus 907: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 908: c->self, len, have);
909: strlcpy(username, p, sizeof(username));
910: buffer_consume(&c->input, len);
911: buffer_consume(&c->input, 1); /* trailing '\0' */
912:
1.104 markus 913: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 914: strlcpy(c->path, host, sizeof(c->path));
915: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 916:
1.106 markus 917: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
918: c->self, host, c->host_port, s4_req.command);
1.103 markus 919:
1.104 markus 920: if (s4_req.command != 1) {
921: debug("channel %d: cannot handle: socks4 cn %d",
922: c->self, s4_req.command);
923: return -1;
1.103 markus 924: }
1.104 markus 925: s4_rsp.version = 0; /* vn: 0 for reply */
926: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 927: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 928: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 929: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 930: return 1;
931: }
932:
933: /* dynamic port forwarding */
1.127 itojun 934: static void
1.104 markus 935: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
936: {
937: u_char *p;
938: int have, ret;
1.103 markus 939:
1.104 markus 940: have = buffer_len(&c->input);
1.137 markus 941: c->delayed = 0;
1.104 markus 942: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 943: /* buffer_dump(&c->input); */
1.104 markus 944: /* check if the fixed size part of the packet is in buffer. */
945: if (have < 4) {
946: /* need more */
947: FD_SET(c->sock, readset);
948: return;
949: }
950: /* try to guess the protocol */
951: p = buffer_ptr(&c->input);
952: switch (p[0]) {
953: case 0x04:
954: ret = channel_decode_socks4(c, readset, writeset);
955: break;
956: default:
957: ret = -1;
958: break;
959: }
960: if (ret < 0) {
1.113 markus 961: chan_mark_dead(c);
1.104 markus 962: } else if (ret == 0) {
963: debug2("channel %d: pre_dynamic: need more", c->self);
964: /* need more */
965: FD_SET(c->sock, readset);
966: } else {
967: /* switch to the next state */
968: c->type = SSH_CHANNEL_OPENING;
969: port_open_helper(c, "direct-tcpip");
970: }
1.103 markus 971: }
972:
1.41 markus 973: /* This is our fake X11 server socket. */
1.127 itojun 974: static void
1.41 markus 975: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
976: {
1.113 markus 977: Channel *nc;
1.41 markus 978: struct sockaddr addr;
1.162 stevesk 979: int newsock;
1.41 markus 980: socklen_t addrlen;
1.85 markus 981: char buf[16384], *remote_ipaddr;
1.51 markus 982: int remote_port;
1.25 markus 983:
1.41 markus 984: if (FD_ISSET(c->sock, readset)) {
985: debug("X11 connection requested.");
986: addrlen = sizeof(addr);
987: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 988: if (c->single_connection) {
989: debug("single_connection: closing X11 listener.");
990: channel_close_fd(&c->sock);
991: chan_mark_dead(c);
992: }
1.41 markus 993: if (newsock < 0) {
994: error("accept: %.100s", strerror(errno));
995: return;
996: }
1.162 stevesk 997: set_nodelay(newsock);
1.85 markus 998: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 999: remote_port = get_peer_port(newsock);
1.41 markus 1000: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1001: remote_ipaddr, remote_port);
1.51 markus 1002:
1.113 markus 1003: nc = channel_new("accepted x11 socket",
1.51 markus 1004: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1005: c->local_window_max, c->local_maxpacket,
1.71 markus 1006: 0, xstrdup(buf), 1);
1.113 markus 1007: if (nc == NULL) {
1008: close(newsock);
1009: xfree(remote_ipaddr);
1010: return;
1011: }
1.51 markus 1012: if (compat20) {
1013: packet_start(SSH2_MSG_CHANNEL_OPEN);
1014: packet_put_cstring("x11");
1.113 markus 1015: packet_put_int(nc->self);
1.149 markus 1016: packet_put_int(nc->local_window_max);
1017: packet_put_int(nc->local_maxpacket);
1.85 markus 1018: /* originator ipaddr and port */
1019: packet_put_cstring(remote_ipaddr);
1.57 markus 1020: if (datafellows & SSH_BUG_X11FWD) {
1021: debug("ssh2 x11 bug compat mode");
1022: } else {
1023: packet_put_int(remote_port);
1024: }
1.51 markus 1025: packet_send();
1026: } else {
1027: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1028: packet_put_int(nc->self);
1.121 markus 1029: if (packet_get_protocol_flags() &
1030: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1031: packet_put_cstring(buf);
1.51 markus 1032: packet_send();
1033: }
1.85 markus 1034: xfree(remote_ipaddr);
1.41 markus 1035: }
1036: }
1.25 markus 1037:
1.127 itojun 1038: static void
1.103 markus 1039: port_open_helper(Channel *c, char *rtype)
1040: {
1041: int direct;
1042: char buf[1024];
1043: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1044: u_short remote_port = get_peer_port(c->sock);
1045:
1046: direct = (strcmp(rtype, "direct-tcpip") == 0);
1047:
1048: snprintf(buf, sizeof buf,
1049: "%s: listening port %d for %.100s port %d, "
1050: "connect from %.200s port %d",
1051: rtype, c->listening_port, c->path, c->host_port,
1052: remote_ipaddr, remote_port);
1053:
1054: xfree(c->remote_name);
1055: c->remote_name = xstrdup(buf);
1056:
1057: if (compat20) {
1058: packet_start(SSH2_MSG_CHANNEL_OPEN);
1059: packet_put_cstring(rtype);
1060: packet_put_int(c->self);
1061: packet_put_int(c->local_window_max);
1062: packet_put_int(c->local_maxpacket);
1063: if (direct) {
1064: /* target host, port */
1065: packet_put_cstring(c->path);
1066: packet_put_int(c->host_port);
1067: } else {
1068: /* listen address, port */
1069: packet_put_cstring(c->path);
1070: packet_put_int(c->listening_port);
1071: }
1072: /* originator host and port */
1073: packet_put_cstring(remote_ipaddr);
1074: packet_put_int(remote_port);
1075: packet_send();
1076: } else {
1077: packet_start(SSH_MSG_PORT_OPEN);
1078: packet_put_int(c->self);
1079: packet_put_cstring(c->path);
1080: packet_put_int(c->host_port);
1.121 markus 1081: if (packet_get_protocol_flags() &
1082: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1083: packet_put_cstring(c->remote_name);
1084: packet_send();
1085: }
1086: xfree(remote_ipaddr);
1087: }
1088:
1.41 markus 1089: /*
1090: * This socket is listening for connections to a forwarded TCP/IP port.
1091: */
1.127 itojun 1092: static void
1.41 markus 1093: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1094: {
1.103 markus 1095: Channel *nc;
1.41 markus 1096: struct sockaddr addr;
1.113 markus 1097: int newsock, nextstate;
1.41 markus 1098: socklen_t addrlen;
1.103 markus 1099: char *rtype;
1.73 markus 1100:
1.41 markus 1101: if (FD_ISSET(c->sock, readset)) {
1102: debug("Connection to port %d forwarding "
1103: "to %.100s port %d requested.",
1104: c->listening_port, c->path, c->host_port);
1.103 markus 1105:
1.137 markus 1106: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1107: nextstate = SSH_CHANNEL_OPENING;
1108: rtype = "forwarded-tcpip";
1109: } else {
1110: if (c->host_port == 0) {
1111: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1112: rtype = "dynamic-tcpip";
1.137 markus 1113: } else {
1114: nextstate = SSH_CHANNEL_OPENING;
1115: rtype = "direct-tcpip";
1116: }
1117: }
1.103 markus 1118:
1.41 markus 1119: addrlen = sizeof(addr);
1120: newsock = accept(c->sock, &addr, &addrlen);
1121: if (newsock < 0) {
1122: error("accept: %.100s", strerror(errno));
1123: return;
1124: }
1.113 markus 1125: nc = channel_new(rtype,
1.103 markus 1126: nextstate, newsock, newsock, -1,
1.41 markus 1127: c->local_window_max, c->local_maxpacket,
1.103 markus 1128: 0, xstrdup(rtype), 1);
1129: if (nc == NULL) {
1.113 markus 1130: error("channel_post_port_listener: no new channel:");
1131: close(newsock);
1.103 markus 1132: return;
1.41 markus 1133: }
1.103 markus 1134: nc->listening_port = c->listening_port;
1135: nc->host_port = c->host_port;
1136: strlcpy(nc->path, c->path, sizeof(nc->path));
1137:
1.137 markus 1138: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1139: /*
1140: * do not call the channel_post handler until
1141: * this flag has been reset by a pre-handler.
1142: * otherwise the FD_ISSET calls might overflow
1143: */
1144: nc->delayed = 1;
1145: } else {
1.103 markus 1146: port_open_helper(nc, rtype);
1.137 markus 1147: }
1.41 markus 1148: }
1149: }
1.25 markus 1150:
1.41 markus 1151: /*
1152: * This is the authentication agent socket listening for connections from
1153: * clients.
1154: */
1.127 itojun 1155: static void
1.41 markus 1156: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1157: {
1.113 markus 1158: Channel *nc;
1.121 markus 1159: char *name;
1.113 markus 1160: int newsock;
1.41 markus 1161: struct sockaddr addr;
1162: socklen_t addrlen;
1.25 markus 1163:
1.41 markus 1164: if (FD_ISSET(c->sock, readset)) {
1165: addrlen = sizeof(addr);
1166: newsock = accept(c->sock, &addr, &addrlen);
1167: if (newsock < 0) {
1168: error("accept from auth socket: %.100s", strerror(errno));
1169: return;
1170: }
1.121 markus 1171: name = xstrdup("accepted auth socket");
1.113 markus 1172: nc = channel_new("accepted auth socket",
1.73 markus 1173: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1174: c->local_window_max, c->local_maxpacket,
1.121 markus 1175: 0, name, 1);
1.113 markus 1176: if (nc == NULL) {
1177: error("channel_post_auth_listener: channel_new failed");
1.121 markus 1178: xfree(name);
1.113 markus 1179: close(newsock);
1180: }
1.73 markus 1181: if (compat20) {
1182: packet_start(SSH2_MSG_CHANNEL_OPEN);
1183: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1184: packet_put_int(nc->self);
1.73 markus 1185: packet_put_int(c->local_window_max);
1186: packet_put_int(c->local_maxpacket);
1187: } else {
1188: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1189: packet_put_int(nc->self);
1.73 markus 1190: }
1.41 markus 1191: packet_send();
1192: }
1193: }
1.25 markus 1194:
1.127 itojun 1195: static void
1.75 markus 1196: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1197: {
1.114 markus 1198: int err = 0;
1.129 stevesk 1199: socklen_t sz = sizeof(err);
1.114 markus 1200:
1.75 markus 1201: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1202: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1203: &sz) < 0) {
1204: err = errno;
1205: error("getsockopt SO_ERROR failed");
1206: }
1207: if (err == 0) {
1208: debug("channel %d: connected", c->self);
1209: c->type = SSH_CHANNEL_OPEN;
1210: if (compat20) {
1211: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1212: packet_put_int(c->remote_id);
1213: packet_put_int(c->self);
1214: packet_put_int(c->local_window);
1215: packet_put_int(c->local_maxpacket);
1216: } else {
1217: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1218: packet_put_int(c->remote_id);
1219: packet_put_int(c->self);
1220: }
1.75 markus 1221: } else {
1.114 markus 1222: debug("channel %d: not connected: %s",
1223: c->self, strerror(err));
1224: if (compat20) {
1225: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1226: packet_put_int(c->remote_id);
1227: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1228: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1229: packet_put_cstring(strerror(err));
1230: packet_put_cstring("");
1231: }
1.75 markus 1232: } else {
1.114 markus 1233: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1234: packet_put_int(c->remote_id);
1.75 markus 1235: }
1.114 markus 1236: chan_mark_dead(c);
1.75 markus 1237: }
1.114 markus 1238: packet_send();
1.75 markus 1239: }
1240: }
1241:
1.127 itojun 1242: static int
1.41 markus 1243: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1244: {
1245: char buf[16*1024];
1246: int len;
1.25 markus 1247:
1.118 markus 1248: if (c->rfd != -1 &&
1.41 markus 1249: FD_ISSET(c->rfd, readset)) {
1250: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1251: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1252: return 1;
1.41 markus 1253: if (len <= 0) {
1.51 markus 1254: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1255: c->self, c->rfd, len);
1.104 markus 1256: if (c->type != SSH_CHANNEL_OPEN) {
1257: debug("channel %d: not open", c->self);
1.113 markus 1258: chan_mark_dead(c);
1.103 markus 1259: return -1;
1.104 markus 1260: } else if (compat13) {
1.158 markus 1261: buffer_clear(&c->output);
1.41 markus 1262: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1263: debug("channel %d: input draining.", c->self);
1.25 markus 1264: } else {
1.41 markus 1265: chan_read_failed(c);
1.25 markus 1266: }
1.41 markus 1267: return -1;
1268: }
1.143 deraadt 1269: if (c->input_filter != NULL) {
1.66 markus 1270: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1271: debug("channel %d: filter stops", c->self);
1.65 markus 1272: chan_read_failed(c);
1273: }
1274: } else {
1275: buffer_append(&c->input, buf, len);
1276: }
1.41 markus 1277: }
1278: return 1;
1279: }
1.127 itojun 1280: static int
1.41 markus 1281: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1282: {
1.95 markus 1283: struct termios tio;
1.134 markus 1284: u_char *data;
1285: u_int dlen;
1.41 markus 1286: int len;
1.25 markus 1287:
1.41 markus 1288: /* Send buffered output data to the socket. */
1.118 markus 1289: if (c->wfd != -1 &&
1.41 markus 1290: FD_ISSET(c->wfd, writeset) &&
1291: buffer_len(&c->output) > 0) {
1.134 markus 1292: data = buffer_ptr(&c->output);
1293: dlen = buffer_len(&c->output);
1294: len = write(c->wfd, data, dlen);
1.53 markus 1295: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1296: return 1;
1.41 markus 1297: if (len <= 0) {
1.104 markus 1298: if (c->type != SSH_CHANNEL_OPEN) {
1299: debug("channel %d: not open", c->self);
1.113 markus 1300: chan_mark_dead(c);
1.104 markus 1301: return -1;
1302: } else if (compat13) {
1.158 markus 1303: buffer_clear(&c->output);
1.121 markus 1304: debug("channel %d: input draining.", c->self);
1.41 markus 1305: c->type = SSH_CHANNEL_INPUT_DRAINING;
1306: } else {
1307: chan_write_failed(c);
1308: }
1309: return -1;
1.91 markus 1310: }
1.134 markus 1311: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1312: if (tcgetattr(c->wfd, &tio) == 0 &&
1313: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1314: /*
1315: * Simulate echo to reduce the impact of
1.96 markus 1316: * traffic analysis. We need to match the
1.95 markus 1317: * size of a SSH2_MSG_CHANNEL_DATA message
1318: * (4 byte channel id + data)
1.91 markus 1319: */
1.95 markus 1320: packet_send_ignore(4 + len);
1.91 markus 1321: packet_send();
1322: }
1.25 markus 1323: }
1.41 markus 1324: buffer_consume(&c->output, len);
1.44 markus 1325: if (compat20 && len > 0) {
1326: c->local_consumed += len;
1327: }
1328: }
1329: return 1;
1330: }
1.127 itojun 1331: static int
1.44 markus 1332: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1333: {
1334: char buf[16*1024];
1335: int len;
1336:
1.45 markus 1337: /** XXX handle drain efd, too */
1.44 markus 1338: if (c->efd != -1) {
1339: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1340: FD_ISSET(c->efd, writeset) &&
1341: buffer_len(&c->extended) > 0) {
1342: len = write(c->efd, buffer_ptr(&c->extended),
1343: buffer_len(&c->extended));
1.70 markus 1344: debug2("channel %d: written %d to efd %d",
1.44 markus 1345: c->self, len, c->efd);
1.93 markus 1346: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1347: return 1;
1348: if (len <= 0) {
1349: debug2("channel %d: closing write-efd %d",
1350: c->self, c->efd);
1.132 markus 1351: channel_close_fd(&c->efd);
1.93 markus 1352: } else {
1.44 markus 1353: buffer_consume(&c->extended, len);
1354: c->local_consumed += len;
1355: }
1356: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1357: FD_ISSET(c->efd, readset)) {
1358: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1359: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1360: c->self, len, c->efd);
1.93 markus 1361: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1362: return 1;
1363: if (len <= 0) {
1364: debug2("channel %d: closing read-efd %d",
1.45 markus 1365: c->self, c->efd);
1.132 markus 1366: channel_close_fd(&c->efd);
1.93 markus 1367: } else {
1.44 markus 1368: buffer_append(&c->extended, buf, len);
1.93 markus 1369: }
1.44 markus 1370: }
1371: }
1372: return 1;
1373: }
1.127 itojun 1374: static int
1.93 markus 1375: channel_check_window(Channel *c)
1.44 markus 1376: {
1.104 markus 1377: if (c->type == SSH_CHANNEL_OPEN &&
1378: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1379: c->local_window < c->local_window_max/2 &&
1380: c->local_consumed > 0) {
1381: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1382: packet_put_int(c->remote_id);
1383: packet_put_int(c->local_consumed);
1384: packet_send();
1.70 markus 1385: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1386: c->self, c->local_window,
1387: c->local_consumed);
1388: c->local_window += c->local_consumed;
1389: c->local_consumed = 0;
1.1 deraadt 1390: }
1.41 markus 1391: return 1;
1.1 deraadt 1392: }
1393:
1.127 itojun 1394: static void
1.157 markus 1395: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1396: {
1.137 markus 1397: if (c->delayed)
1398: return;
1.41 markus 1399: channel_handle_rfd(c, readset, writeset);
1400: channel_handle_wfd(c, readset, writeset);
1.157 markus 1401: if (!compat20)
1.137 markus 1402: return;
1.44 markus 1403: channel_handle_efd(c, readset, writeset);
1.93 markus 1404: channel_check_window(c);
1.44 markus 1405: }
1406:
1.127 itojun 1407: static void
1.41 markus 1408: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1409: {
1.41 markus 1410: int len;
1411: /* Send buffered output data to the socket. */
1412: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1413: len = write(c->sock, buffer_ptr(&c->output),
1414: buffer_len(&c->output));
1415: if (len <= 0)
1.158 markus 1416: buffer_clear(&c->output);
1.41 markus 1417: else
1418: buffer_consume(&c->output, len);
1419: }
1420: }
1.25 markus 1421:
1.127 itojun 1422: static void
1.44 markus 1423: channel_handler_init_20(void)
1424: {
1.157 markus 1425: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1426: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1427: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1428: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1429: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1430: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1431: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1432: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1433:
1.157 markus 1434: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1435: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1436: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1437: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1438: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1439: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1440: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1441: }
1442:
1.127 itojun 1443: static void
1.41 markus 1444: channel_handler_init_13(void)
1445: {
1446: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1447: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1448: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1449: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1450: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1451: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1452: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1453: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1454: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1455:
1.157 markus 1456: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1457: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1458: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1459: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1460: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1461: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1462: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1463: }
1.25 markus 1464:
1.127 itojun 1465: static void
1.41 markus 1466: channel_handler_init_15(void)
1467: {
1.157 markus 1468: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1469: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1470: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1471: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1472: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1473: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1474: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1475:
1.41 markus 1476: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1477: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1478: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1479: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1480: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1481: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1482: }
1.27 markus 1483:
1.127 itojun 1484: static void
1.41 markus 1485: channel_handler_init(void)
1486: {
1487: int i;
1.148 deraadt 1488: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1489: channel_pre[i] = NULL;
1490: channel_post[i] = NULL;
1491: }
1.44 markus 1492: if (compat20)
1493: channel_handler_init_20();
1494: else if (compat13)
1.41 markus 1495: channel_handler_init_13();
1496: else
1497: channel_handler_init_15();
1498: }
1.25 markus 1499:
1.140 markus 1500: /* gc dead channels */
1501: static void
1502: channel_garbage_collect(Channel *c)
1503: {
1504: if (c == NULL)
1505: return;
1506: if (c->detach_user != NULL) {
1507: if (!chan_is_dead(c, 0))
1508: return;
1509: debug("channel %d: gc: notify user", c->self);
1510: c->detach_user(c->self, NULL);
1511: /* if we still have a callback */
1512: if (c->detach_user != NULL)
1513: return;
1514: debug("channel %d: gc: user detached", c->self);
1515: }
1516: if (!chan_is_dead(c, 1))
1517: return;
1518: debug("channel %d: garbage collecting", c->self);
1519: channel_free(c);
1520: }
1521:
1.127 itojun 1522: static void
1.41 markus 1523: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1524: {
1525: static int did_init = 0;
1526: int i;
1527: Channel *c;
1.25 markus 1528:
1.41 markus 1529: if (!did_init) {
1530: channel_handler_init();
1531: did_init = 1;
1532: }
1533: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1534: c = channels[i];
1535: if (c == NULL)
1.41 markus 1536: continue;
1.118 markus 1537: if (ftab[c->type] != NULL)
1538: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1539: channel_garbage_collect(c);
1.1 deraadt 1540: }
1541: }
1542:
1.121 markus 1543: /*
1544: * Allocate/update select bitmasks and add any bits relevant to channels in
1545: * select bitmasks.
1546: */
1.49 markus 1547: void
1.100 markus 1548: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1549: int *nallocp, int rekeying)
1.41 markus 1550: {
1.84 markus 1551: int n;
1552: u_int sz;
1553:
1554: n = MAX(*maxfdp, channel_max_fd);
1555:
1556: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1557: /* perhaps check sz < nalloc/2 and shrink? */
1558: if (*readsetp == NULL || sz > *nallocp) {
1559: *readsetp = xrealloc(*readsetp, sz);
1560: *writesetp = xrealloc(*writesetp, sz);
1561: *nallocp = sz;
1.84 markus 1562: }
1.132 markus 1563: *maxfdp = n;
1.84 markus 1564: memset(*readsetp, 0, sz);
1565: memset(*writesetp, 0, sz);
1566:
1.100 markus 1567: if (!rekeying)
1568: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1569: }
1570:
1.121 markus 1571: /*
1572: * After select, perform any appropriate operations for channels which have
1573: * events pending.
1574: */
1.49 markus 1575: void
1.41 markus 1576: channel_after_select(fd_set * readset, fd_set * writeset)
1577: {
1578: channel_handler(channel_post, readset, writeset);
1579: }
1580:
1.121 markus 1581:
1.84 markus 1582: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1583:
1.49 markus 1584: void
1.142 itojun 1585: channel_output_poll(void)
1.1 deraadt 1586: {
1.25 markus 1587: int len, i;
1.41 markus 1588: Channel *c;
1.1 deraadt 1589:
1.25 markus 1590: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1591: c = channels[i];
1592: if (c == NULL)
1593: continue;
1.37 markus 1594:
1.121 markus 1595: /*
1596: * We are only interested in channels that can have buffered
1597: * incoming data.
1598: */
1.37 markus 1599: if (compat13) {
1.41 markus 1600: if (c->type != SSH_CHANNEL_OPEN &&
1601: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1602: continue;
1603: } else {
1.41 markus 1604: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1605: continue;
1606: }
1.46 markus 1607: if (compat20 &&
1608: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1609: /* XXX is this true? */
1.140 markus 1610: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1611: continue;
1612: }
1.25 markus 1613:
1614: /* Get the amount of buffered data for this channel. */
1.93 markus 1615: if ((c->istate == CHAN_INPUT_OPEN ||
1616: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1617: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1618: /*
1619: * Send some data for the other side over the secure
1620: * connection.
1621: */
1.44 markus 1622: if (compat20) {
1623: if (len > c->remote_window)
1624: len = c->remote_window;
1625: if (len > c->remote_maxpacket)
1626: len = c->remote_maxpacket;
1.25 markus 1627: } else {
1.44 markus 1628: if (packet_is_interactive()) {
1629: if (len > 1024)
1630: len = 512;
1631: } else {
1632: /* Keep the packets at reasonable size. */
1633: if (len > packet_get_maxsize()/2)
1634: len = packet_get_maxsize()/2;
1635: }
1.25 markus 1636: }
1.41 markus 1637: if (len > 0) {
1.44 markus 1638: packet_start(compat20 ?
1639: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1640: packet_put_int(c->remote_id);
1641: packet_put_string(buffer_ptr(&c->input), len);
1642: packet_send();
1643: buffer_consume(&c->input, len);
1644: c->remote_window -= len;
1645: }
1646: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1647: if (compat13)
1648: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1649: /*
1650: * input-buffer is empty and read-socket shutdown:
1651: * tell peer, that we will not send more data: send IEOF
1652: */
1.41 markus 1653: chan_ibuf_empty(c);
1.25 markus 1654: }
1.44 markus 1655: /* Send extended data, i.e. stderr */
1656: if (compat20 &&
1657: c->remote_window > 0 &&
1658: (len = buffer_len(&c->extended)) > 0 &&
1659: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1660: debug2("channel %d: rwin %d elen %d euse %d",
1661: c->self, c->remote_window, buffer_len(&c->extended),
1662: c->extended_usage);
1.44 markus 1663: if (len > c->remote_window)
1664: len = c->remote_window;
1665: if (len > c->remote_maxpacket)
1666: len = c->remote_maxpacket;
1667: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1668: packet_put_int(c->remote_id);
1669: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1670: packet_put_string(buffer_ptr(&c->extended), len);
1671: packet_send();
1672: buffer_consume(&c->extended, len);
1673: c->remote_window -= len;
1.93 markus 1674: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1675: }
1.25 markus 1676: }
1.1 deraadt 1677: }
1678:
1.121 markus 1679:
1680: /* -- protocol input */
1.1 deraadt 1681:
1.49 markus 1682: void
1.154 markus 1683: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1684: {
1.37 markus 1685: int id;
1.25 markus 1686: char *data;
1.77 markus 1687: u_int data_len;
1.41 markus 1688: Channel *c;
1.25 markus 1689:
1690: /* Get the channel number and verify it. */
1.37 markus 1691: id = packet_get_int();
1.41 markus 1692: c = channel_lookup(id);
1693: if (c == NULL)
1.37 markus 1694: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1695:
1696: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1697: if (c->type != SSH_CHANNEL_OPEN &&
1698: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1699: return;
1700:
1701: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1702: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1703: return;
1704:
1705: /* Get the data. */
1706: data = packet_get_string(&data_len);
1.41 markus 1707:
1.143 deraadt 1708: if (compat20) {
1.44 markus 1709: if (data_len > c->local_maxpacket) {
1710: log("channel %d: rcvd big packet %d, maxpack %d",
1711: c->self, data_len, c->local_maxpacket);
1712: }
1713: if (data_len > c->local_window) {
1714: log("channel %d: rcvd too much data %d, win %d",
1715: c->self, data_len, c->local_window);
1716: xfree(data);
1717: return;
1718: }
1719: c->local_window -= data_len;
1720: }
1.152 markus 1721: packet_check_eom();
1.41 markus 1722: buffer_append(&c->output, data, data_len);
1.25 markus 1723: xfree(data);
1.1 deraadt 1724: }
1.121 markus 1725:
1.49 markus 1726: void
1.154 markus 1727: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1728: {
1729: int id;
1730: int tcode;
1731: char *data;
1.77 markus 1732: u_int data_len;
1.44 markus 1733: Channel *c;
1734:
1735: /* Get the channel number and verify it. */
1736: id = packet_get_int();
1737: c = channel_lookup(id);
1738:
1739: if (c == NULL)
1740: packet_disconnect("Received extended_data for bad channel %d.", id);
1741: if (c->type != SSH_CHANNEL_OPEN) {
1742: log("channel %d: ext data for non open", id);
1743: return;
1744: }
1745: tcode = packet_get_int();
1746: if (c->efd == -1 ||
1747: c->extended_usage != CHAN_EXTENDED_WRITE ||
1748: tcode != SSH2_EXTENDED_DATA_STDERR) {
1749: log("channel %d: bad ext data", c->self);
1750: return;
1751: }
1752: data = packet_get_string(&data_len);
1.152 markus 1753: packet_check_eom();
1.44 markus 1754: if (data_len > c->local_window) {
1755: log("channel %d: rcvd too much extended_data %d, win %d",
1756: c->self, data_len, c->local_window);
1757: xfree(data);
1758: return;
1759: }
1.70 markus 1760: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1761: c->local_window -= data_len;
1762: buffer_append(&c->extended, data, data_len);
1763: xfree(data);
1764: }
1765:
1.49 markus 1766: void
1.154 markus 1767: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1768: {
1769: int id;
1770: Channel *c;
1771:
1772: id = packet_get_int();
1.152 markus 1773: packet_check_eom();
1.41 markus 1774: c = channel_lookup(id);
1775: if (c == NULL)
1776: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1777: chan_rcvd_ieof(c);
1.133 markus 1778:
1779: /* XXX force input close */
1.156 markus 1780: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1781: debug("channel %d: FORCE input drain", c->self);
1782: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1783: if (buffer_len(&c->input) == 0)
1784: chan_ibuf_empty(c);
1.133 markus 1785: }
1786:
1.41 markus 1787: }
1.1 deraadt 1788:
1.49 markus 1789: void
1.154 markus 1790: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1791: {
1.41 markus 1792: int id;
1793: Channel *c;
1.1 deraadt 1794:
1.41 markus 1795: id = packet_get_int();
1.152 markus 1796: packet_check_eom();
1.41 markus 1797: c = channel_lookup(id);
1798: if (c == NULL)
1799: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1800:
1801: /*
1802: * Send a confirmation that we have closed the channel and no more
1803: * data is coming for it.
1804: */
1.25 markus 1805: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1806: packet_put_int(c->remote_id);
1.25 markus 1807: packet_send();
1808:
1.27 markus 1809: /*
1810: * If the channel is in closed state, we have sent a close request,
1811: * and the other side will eventually respond with a confirmation.
1812: * Thus, we cannot free the channel here, because then there would be
1813: * no-one to receive the confirmation. The channel gets freed when
1814: * the confirmation arrives.
1815: */
1.41 markus 1816: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1817: /*
1818: * Not a closed channel - mark it as draining, which will
1819: * cause it to be freed later.
1820: */
1.158 markus 1821: buffer_clear(&c->input);
1.41 markus 1822: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1823: }
1.1 deraadt 1824: }
1825:
1.41 markus 1826: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1827: void
1.154 markus 1828: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1829: {
1830: int id = packet_get_int();
1831: Channel *c = channel_lookup(id);
1.151 markus 1832:
1.152 markus 1833: packet_check_eom();
1.41 markus 1834: if (c == NULL)
1835: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1836: chan_rcvd_oclose(c);
1837: }
1.1 deraadt 1838:
1.49 markus 1839: void
1.154 markus 1840: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1841: {
1.41 markus 1842: int id = packet_get_int();
1843: Channel *c = channel_lookup(id);
1.1 deraadt 1844:
1.152 markus 1845: packet_check_eom();
1.41 markus 1846: if (c == NULL)
1847: packet_disconnect("Received close confirmation for "
1848: "out-of-range channel %d.", id);
1849: if (c->type != SSH_CHANNEL_CLOSED)
1850: packet_disconnect("Received close confirmation for "
1851: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1852: channel_free(c);
1.1 deraadt 1853: }
1854:
1.49 markus 1855: void
1.154 markus 1856: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1857: {
1.41 markus 1858: int id, remote_id;
1859: Channel *c;
1.1 deraadt 1860:
1.41 markus 1861: id = packet_get_int();
1862: c = channel_lookup(id);
1.25 markus 1863:
1.41 markus 1864: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1865: packet_disconnect("Received open confirmation for "
1866: "non-opening channel %d.", id);
1867: remote_id = packet_get_int();
1.27 markus 1868: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1869: c->remote_id = remote_id;
1870: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1871:
1872: if (compat20) {
1873: c->remote_window = packet_get_int();
1874: c->remote_maxpacket = packet_get_int();
1.165 markus 1875: if (c->confirm) {
1.70 markus 1876: debug2("callback start");
1.165 markus 1877: c->confirm(c->self, NULL);
1.70 markus 1878: debug2("callback done");
1.44 markus 1879: }
1880: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1881: c->remote_window, c->remote_maxpacket);
1882: }
1.152 markus 1883: packet_check_eom();
1.1 deraadt 1884: }
1885:
1.127 itojun 1886: static char *
1.114 markus 1887: reason2txt(int reason)
1888: {
1.143 deraadt 1889: switch (reason) {
1.114 markus 1890: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1891: return "administratively prohibited";
1892: case SSH2_OPEN_CONNECT_FAILED:
1893: return "connect failed";
1894: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1895: return "unknown channel type";
1896: case SSH2_OPEN_RESOURCE_SHORTAGE:
1897: return "resource shortage";
1898: }
1.117 stevesk 1899: return "unknown reason";
1.114 markus 1900: }
1901:
1.49 markus 1902: void
1.154 markus 1903: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1904: {
1.86 markus 1905: int id, reason;
1906: char *msg = NULL, *lang = NULL;
1.41 markus 1907: Channel *c;
1908:
1909: id = packet_get_int();
1910: c = channel_lookup(id);
1.25 markus 1911:
1.41 markus 1912: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1913: packet_disconnect("Received open failure for "
1914: "non-opening channel %d.", id);
1.44 markus 1915: if (compat20) {
1.86 markus 1916: reason = packet_get_int();
1.110 markus 1917: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1918: msg = packet_get_string(NULL);
1919: lang = packet_get_string(NULL);
1920: }
1.114 markus 1921: log("channel %d: open failed: %s%s%s", id,
1922: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1923: if (msg != NULL)
1924: xfree(msg);
1925: if (lang != NULL)
1926: xfree(lang);
1.44 markus 1927: }
1.152 markus 1928: packet_check_eom();
1.25 markus 1929: /* Free the channel. This will also close the socket. */
1.113 markus 1930: channel_free(c);
1.44 markus 1931: }
1932:
1.121 markus 1933: void
1.154 markus 1934: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1935: {
1936: Channel *c;
1937: int id, adjust;
1938:
1939: if (!compat20)
1940: return;
1941:
1942: /* Get the channel number and verify it. */
1943: id = packet_get_int();
1944: c = channel_lookup(id);
1.1 deraadt 1945:
1.121 markus 1946: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1947: log("Received window adjust for "
1948: "non-open channel %d.", id);
1949: return;
1950: }
1951: adjust = packet_get_int();
1.152 markus 1952: packet_check_eom();
1.121 markus 1953: debug2("channel %d: rcvd adjust %d", id, adjust);
1954: c->remote_window += adjust;
1955: }
1.1 deraadt 1956:
1.121 markus 1957: void
1.154 markus 1958: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1959: {
1.121 markus 1960: Channel *c = NULL;
1961: u_short host_port;
1962: char *host, *originator_string;
1963: int remote_id, sock = -1;
1964:
1965: remote_id = packet_get_int();
1966: host = packet_get_string(NULL);
1967: host_port = packet_get_int();
1.25 markus 1968:
1.121 markus 1969: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1970: originator_string = packet_get_string(NULL);
1971: } else {
1972: originator_string = xstrdup("unknown (remote did not supply name)");
1973: }
1.152 markus 1974: packet_check_eom();
1.121 markus 1975: sock = channel_connect_to(host, host_port);
1976: if (sock != -1) {
1977: c = channel_new("connected socket",
1978: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1979: originator_string, 1);
1980: if (c == NULL) {
1981: error("channel_input_port_open: channel_new failed");
1982: close(sock);
1983: } else {
1984: c->remote_id = remote_id;
1.25 markus 1985: }
1986: }
1.121 markus 1987: if (c == NULL) {
1988: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1989: packet_put_int(remote_id);
1990: packet_send();
1991: }
1992: xfree(host);
1.1 deraadt 1993: }
1994:
1.121 markus 1995:
1996: /* -- tcp forwarding */
1.135 markus 1997:
1998: void
1999: channel_set_af(int af)
2000: {
2001: IPv4or6 = af;
2002: }
1.121 markus 2003:
1.160 markus 2004: static int
2005: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2006: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2007: {
1.113 markus 2008: Channel *c;
1.160 markus 2009: int success, sock, on = 1;
1.35 markus 2010: struct addrinfo hints, *ai, *aitop;
1.160 markus 2011: const char *host;
1.35 markus 2012: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2013: struct linger linger;
1.25 markus 2014:
1.87 markus 2015: success = 0;
1.160 markus 2016: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2017: listen_addr : host_to_connect;
1.87 markus 2018:
1.160 markus 2019: if (host == NULL) {
2020: error("No forward host name.");
2021: return success;
1.73 markus 2022: }
1.113 markus 2023: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2024: error("Forward host name too long.");
2025: return success;
2026: }
1.25 markus 2027:
1.28 markus 2028: /*
1.35 markus 2029: * getaddrinfo returns a loopback address if the hostname is
2030: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2031: */
1.35 markus 2032: memset(&hints, 0, sizeof(hints));
2033: hints.ai_family = IPv4or6;
2034: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2035: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2036: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2037: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2038: packet_disconnect("getaddrinfo: fatal error");
2039:
2040: for (ai = aitop; ai; ai = ai->ai_next) {
2041: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2042: continue;
2043: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2044: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2045: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2046: continue;
2047: }
2048: /* Create a port to listen for the host. */
2049: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2050: if (sock < 0) {
2051: /* this is no error since kernel may not support ipv6 */
2052: verbose("socket: %.100s", strerror(errno));
2053: continue;
2054: }
2055: /*
2056: * Set socket options. We would like the socket to disappear
2057: * as soon as it has been closed for whatever reason.
2058: */
2059: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2060: linger.l_onoff = 1;
2061: linger.l_linger = 5;
2062: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2063: debug("Local forwarding listening on %s port %s.", ntop, strport);
2064:
2065: /* Bind the socket to the address. */
2066: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2067: /* address can be in use ipv6 address is already bound */
2068: verbose("bind: %.100s", strerror(errno));
2069: close(sock);
2070: continue;
2071: }
2072: /* Start listening for connections on the socket. */
2073: if (listen(sock, 5) < 0) {
2074: error("listen: %.100s", strerror(errno));
2075: close(sock);
2076: continue;
2077: }
2078: /* Allocate a channel number for the socket. */
1.121 markus 2079: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2080: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2081: 0, xstrdup("port listener"), 1);
1.113 markus 2082: if (c == NULL) {
1.160 markus 2083: error("channel_setup_fwd_listener: channel_new failed");
1.113 markus 2084: close(sock);
2085: continue;
2086: }
2087: strlcpy(c->path, host, sizeof(c->path));
2088: c->host_port = port_to_connect;
2089: c->listening_port = listen_port;
1.35 markus 2090: success = 1;
2091: }
2092: if (success == 0)
1.160 markus 2093: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2094: listen_port);
1.35 markus 2095: freeaddrinfo(aitop);
1.87 markus 2096: return success;
1.25 markus 2097: }
1.1 deraadt 2098:
1.160 markus 2099: /* protocol local port fwd, used by ssh (and sshd in v1) */
2100: int
2101: channel_setup_local_fwd_listener(u_short listen_port,
2102: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2103: {
2104: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2105: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2106: }
2107:
2108: /* protocol v2 remote port fwd, used by sshd */
2109: int
2110: channel_setup_remote_fwd_listener(const char *listen_address,
2111: u_short listen_port, int gateway_ports)
2112: {
2113: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2114: listen_address, listen_port, NULL, 0, gateway_ports);
2115: }
2116:
1.27 markus 2117: /*
2118: * Initiate forwarding of connections to port "port" on remote host through
2119: * the secure channel to host:port from local side.
2120: */
1.1 deraadt 2121:
1.49 markus 2122: void
1.73 markus 2123: channel_request_remote_forwarding(u_short listen_port,
2124: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2125: {
1.153 markus 2126: int type, success = 0;
1.73 markus 2127:
1.25 markus 2128: /* Record locally that connection to this host/port is permitted. */
2129: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2130: fatal("channel_request_remote_forwarding: too many forwards");
2131:
2132: /* Send the forward request to the remote side. */
1.44 markus 2133: if (compat20) {
2134: const char *address_to_bind = "0.0.0.0";
2135: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2136: packet_put_cstring("tcpip-forward");
2137: packet_put_char(0); /* boolean: want reply */
2138: packet_put_cstring(address_to_bind);
2139: packet_put_int(listen_port);
1.73 markus 2140: packet_send();
2141: packet_write_wait();
2142: /* Assume that server accepts the request */
2143: success = 1;
1.44 markus 2144: } else {
2145: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2146: packet_put_int(listen_port);
2147: packet_put_cstring(host_to_connect);
1.44 markus 2148: packet_put_int(port_to_connect);
2149: packet_send();
2150: packet_write_wait();
1.73 markus 2151:
2152: /* Wait for response from the remote side. */
1.153 markus 2153: type = packet_read();
1.73 markus 2154: switch (type) {
2155: case SSH_SMSG_SUCCESS:
2156: success = 1;
2157: break;
2158: case SSH_SMSG_FAILURE:
2159: log("Warning: Server denied remote port forwarding.");
2160: break;
2161: default:
2162: /* Unknown packet */
2163: packet_disconnect("Protocol error for port forward request:"
2164: "received packet type %d.", type);
2165: }
2166: }
2167: if (success) {
2168: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2169: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2170: permitted_opens[num_permitted_opens].listen_port = listen_port;
2171: num_permitted_opens++;
1.44 markus 2172: }
1.1 deraadt 2173: }
2174:
1.27 markus 2175: /*
2176: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2177: * listening for the port, and sends back a success reply (or disconnect
2178: * message if there was an error). This never returns if there was an error.
2179: */
1.1 deraadt 2180:
1.49 markus 2181: void
1.56 markus 2182: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2183: {
1.31 markus 2184: u_short port, host_port;
1.25 markus 2185: char *hostname;
1.1 deraadt 2186:
1.25 markus 2187: /* Get arguments from the packet. */
2188: port = packet_get_int();
2189: hostname = packet_get_string(NULL);
2190: host_port = packet_get_int();
2191:
1.27 markus 2192: /*
2193: * Check that an unprivileged user is not trying to forward a
2194: * privileged port.
2195: */
1.25 markus 2196: if (port < IPPORT_RESERVED && !is_root)
2197: packet_disconnect("Requested forwarding of port %d but user is not root.",
2198: port);
1.73 markus 2199: /* Initiate forwarding */
1.160 markus 2200: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2201:
2202: /* Free the argument string. */
2203: xfree(hostname);
1.1 deraadt 2204: }
2205:
1.99 markus 2206: /*
2207: * Permits opening to any host/port if permitted_opens[] is empty. This is
2208: * usually called by the server, because the user could connect to any port
2209: * anyway, and the server has no way to know but to trust the client anyway.
2210: */
2211: void
1.142 itojun 2212: channel_permit_all_opens(void)
1.99 markus 2213: {
2214: if (num_permitted_opens == 0)
2215: all_opens_permitted = 1;
2216: }
2217:
1.101 markus 2218: void
1.99 markus 2219: channel_add_permitted_opens(char *host, int port)
2220: {
2221: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2222: fatal("channel_request_remote_forwarding: too many forwards");
2223: debug("allow port forwarding to host %s port %d", host, port);
2224:
2225: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2226: permitted_opens[num_permitted_opens].port_to_connect = port;
2227: num_permitted_opens++;
2228:
2229: all_opens_permitted = 0;
2230: }
2231:
1.101 markus 2232: void
1.99 markus 2233: channel_clear_permitted_opens(void)
2234: {
2235: int i;
2236:
2237: for (i = 0; i < num_permitted_opens; i++)
2238: xfree(permitted_opens[i].host_to_connect);
2239: num_permitted_opens = 0;
2240:
2241: }
2242:
2243:
2244: /* return socket to remote host, port */
1.127 itojun 2245: static int
1.99 markus 2246: connect_to(const char *host, u_short port)
1.41 markus 2247: {
2248: struct addrinfo hints, *ai, *aitop;
2249: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2250: int gaierr;
2251: int sock = -1;
2252:
2253: memset(&hints, 0, sizeof(hints));
2254: hints.ai_family = IPv4or6;
2255: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2256: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2257: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2258: error("connect_to %.100s: unknown host (%s)", host,
2259: gai_strerror(gaierr));
1.41 markus 2260: return -1;
2261: }
2262: for (ai = aitop; ai; ai = ai->ai_next) {
2263: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2264: continue;
2265: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2266: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2267: error("connect_to: getnameinfo failed");
1.41 markus 2268: continue;
2269: }
2270: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2271: if (sock < 0) {
2272: error("socket: %.100s", strerror(errno));
2273: continue;
2274: }
1.80 markus 2275: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2276: fatal("connect_to: F_SETFL: %s", strerror(errno));
2277: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2278: errno != EINPROGRESS) {
1.99 markus 2279: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2280: strerror(errno));
2281: close(sock);
1.89 stevesk 2282: continue; /* fail -- try next */
1.41 markus 2283: }
2284: break; /* success */
2285:
2286: }
2287: freeaddrinfo(aitop);
2288: if (!ai) {
1.99 markus 2289: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2290: return -1;
2291: }
2292: /* success */
2293: return sock;
2294: }
1.99 markus 2295:
1.73 markus 2296: int
1.130 stevesk 2297: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2298: {
2299: int i;
1.99 markus 2300:
1.73 markus 2301: for (i = 0; i < num_permitted_opens; i++)
2302: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2303: return connect_to(
1.73 markus 2304: permitted_opens[i].host_to_connect,
2305: permitted_opens[i].port_to_connect);
1.74 markus 2306: error("WARNING: Server requests forwarding for unknown listen_port %d",
2307: listen_port);
1.73 markus 2308: return -1;
2309: }
2310:
1.99 markus 2311: /* Check if connecting to that port is permitted and connect. */
2312: int
2313: channel_connect_to(const char *host, u_short port)
2314: {
2315: int i, permit;
2316:
2317: permit = all_opens_permitted;
2318: if (!permit) {
2319: for (i = 0; i < num_permitted_opens; i++)
2320: if (permitted_opens[i].port_to_connect == port &&
2321: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2322: permit = 1;
2323:
2324: }
2325: if (!permit) {
2326: log("Received request to connect to host %.100s port %d, "
2327: "but the request was denied.", host, port);
2328: return -1;
2329: }
2330: return connect_to(host, port);
2331: }
2332:
1.121 markus 2333: /* -- X11 forwarding */
1.1 deraadt 2334:
1.27 markus 2335: /*
2336: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2337: * Returns a suitable display number for the DISPLAY variable, or -1 if
2338: * an error occurs.
1.27 markus 2339: */
1.141 stevesk 2340: int
1.163 stevesk 2341: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.149 markus 2342: int single_connection)
1.1 deraadt 2343: {
1.149 markus 2344: Channel *nc = NULL;
1.31 markus 2345: int display_number, sock;
2346: u_short port;
1.35 markus 2347: struct addrinfo hints, *ai, *aitop;
2348: char strport[NI_MAXSERV];
2349: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2350:
1.33 markus 2351: for (display_number = x11_display_offset;
1.148 deraadt 2352: display_number < MAX_DISPLAYS;
2353: display_number++) {
1.25 markus 2354: port = 6000 + display_number;
1.35 markus 2355: memset(&hints, 0, sizeof(hints));
2356: hints.ai_family = IPv4or6;
1.163 stevesk 2357: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2358: hints.ai_socktype = SOCK_STREAM;
2359: snprintf(strport, sizeof strport, "%d", port);
2360: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2361: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2362: return -1;
1.25 markus 2363: }
1.35 markus 2364: for (ai = aitop; ai; ai = ai->ai_next) {
2365: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2366: continue;
2367: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2368: if (sock < 0) {
2369: error("socket: %.100s", strerror(errno));
1.141 stevesk 2370: return -1;
1.35 markus 2371: }
2372: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2373: debug("bind port %d: %.100s", port, strerror(errno));
2374: close(sock);
2375: for (n = 0; n < num_socks; n++) {
2376: close(socks[n]);
2377: }
2378: num_socks = 0;
2379: break;
2380: }
2381: socks[num_socks++] = sock;
2382: if (num_socks == NUM_SOCKS)
2383: break;
1.25 markus 2384: }
1.83 stevesk 2385: freeaddrinfo(aitop);
1.35 markus 2386: if (num_socks > 0)
2387: break;
1.25 markus 2388: }
2389: if (display_number >= MAX_DISPLAYS) {
2390: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2391: return -1;
1.25 markus 2392: }
2393: /* Start listening for connections on the socket. */
1.35 markus 2394: for (n = 0; n < num_socks; n++) {
2395: sock = socks[n];
2396: if (listen(sock, 5) < 0) {
2397: error("listen: %.100s", strerror(errno));
2398: close(sock);
1.141 stevesk 2399: return -1;
1.35 markus 2400: }
1.25 markus 2401: }
1.35 markus 2402:
2403: /* Allocate a channel for each socket. */
2404: for (n = 0; n < num_socks; n++) {
2405: sock = socks[n];
1.149 markus 2406: nc = channel_new("x11 listener",
1.51 markus 2407: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2408: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2409: 0, xstrdup("X11 inet listener"), 1);
1.149 markus 2410: if (nc != NULL)
2411: nc->single_connection = single_connection;
1.35 markus 2412: }
1.1 deraadt 2413:
1.141 stevesk 2414: /* Return the display number for the DISPLAY environment variable. */
2415: return display_number;
1.1 deraadt 2416: }
2417:
1.127 itojun 2418: static int
1.77 markus 2419: connect_local_xsocket(u_int dnr)
1.1 deraadt 2420: {
1.25 markus 2421: int sock;
2422: struct sockaddr_un addr;
2423:
1.147 stevesk 2424: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2425: if (sock < 0)
2426: error("socket: %.100s", strerror(errno));
2427: memset(&addr, 0, sizeof(addr));
2428: addr.sun_family = AF_UNIX;
2429: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2430: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2431: return sock;
2432: close(sock);
1.25 markus 2433: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2434: return -1;
1.1 deraadt 2435: }
2436:
1.51 markus 2437: int
2438: x11_connect_display(void)
1.1 deraadt 2439: {
1.162 stevesk 2440: int display_number, sock = 0;
1.25 markus 2441: const char *display;
1.51 markus 2442: char buf[1024], *cp;
1.35 markus 2443: struct addrinfo hints, *ai, *aitop;
2444: char strport[NI_MAXSERV];
2445: int gaierr;
1.25 markus 2446:
2447: /* Try to open a socket for the local X server. */
2448: display = getenv("DISPLAY");
2449: if (!display) {
2450: error("DISPLAY not set.");
1.51 markus 2451: return -1;
1.25 markus 2452: }
1.27 markus 2453: /*
2454: * Now we decode the value of the DISPLAY variable and make a
2455: * connection to the real X server.
2456: */
2457:
2458: /*
2459: * Check if it is a unix domain socket. Unix domain displays are in
2460: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2461: */
1.25 markus 2462: if (strncmp(display, "unix:", 5) == 0 ||
2463: display[0] == ':') {
2464: /* Connect to the unix domain socket. */
2465: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2466: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2467: display);
1.51 markus 2468: return -1;
1.25 markus 2469: }
2470: /* Create a socket. */
2471: sock = connect_local_xsocket(display_number);
2472: if (sock < 0)
1.51 markus 2473: return -1;
1.25 markus 2474:
2475: /* OK, we now have a connection to the display. */
1.51 markus 2476: return sock;
1.25 markus 2477: }
1.27 markus 2478: /*
2479: * Connect to an inet socket. The DISPLAY value is supposedly
2480: * hostname:d[.s], where hostname may also be numeric IP address.
2481: */
1.145 stevesk 2482: strlcpy(buf, display, sizeof(buf));
1.25 markus 2483: cp = strchr(buf, ':');
2484: if (!cp) {
2485: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2486: return -1;
1.25 markus 2487: }
2488: *cp = 0;
1.27 markus 2489: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2490: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2491: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2492: display);
1.51 markus 2493: return -1;
1.25 markus 2494: }
1.35 markus 2495:
2496: /* Look up the host address */
2497: memset(&hints, 0, sizeof(hints));
2498: hints.ai_family = IPv4or6;
2499: hints.ai_socktype = SOCK_STREAM;
2500: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2501: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2502: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2503: return -1;
1.25 markus 2504: }
1.35 markus 2505: for (ai = aitop; ai; ai = ai->ai_next) {
2506: /* Create a socket. */
2507: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2508: if (sock < 0) {
2509: debug("socket: %.100s", strerror(errno));
1.41 markus 2510: continue;
2511: }
2512: /* Connect it to the display. */
2513: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2514: debug("connect %.100s port %d: %.100s", buf,
2515: 6000 + display_number, strerror(errno));
2516: close(sock);
2517: continue;
2518: }
2519: /* Success */
2520: break;
1.35 markus 2521: }
2522: freeaddrinfo(aitop);
2523: if (!ai) {
1.49 markus 2524: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2525: strerror(errno));
1.51 markus 2526: return -1;
1.25 markus 2527: }
1.162 stevesk 2528: set_nodelay(sock);
1.51 markus 2529: return sock;
2530: }
2531:
2532: /*
2533: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2534: * the remote channel number. We should do whatever we want, and respond
2535: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2536: */
2537:
2538: void
1.154 markus 2539: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2540: {
1.113 markus 2541: Channel *c = NULL;
2542: int remote_id, sock = 0;
1.51 markus 2543: char *remote_host;
1.25 markus 2544:
1.113 markus 2545: debug("Received X11 open request.");
1.51 markus 2546:
1.113 markus 2547: remote_id = packet_get_int();
1.121 markus 2548:
2549: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2550: remote_host = packet_get_string(NULL);
1.51 markus 2551: } else {
2552: remote_host = xstrdup("unknown (remote did not supply name)");
2553: }
1.152 markus 2554: packet_check_eom();
1.25 markus 2555:
1.51 markus 2556: /* Obtain a connection to the real X display. */
2557: sock = x11_connect_display();
1.113 markus 2558: if (sock != -1) {
2559: /* Allocate a channel for this connection. */
2560: c = channel_new("connected x11 socket",
2561: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2562: remote_host, 1);
2563: if (c == NULL) {
2564: error("x11_input_open: channel_new failed");
2565: close(sock);
2566: } else {
2567: c->remote_id = remote_id;
1.133 markus 2568: c->force_drain = 1;
1.113 markus 2569: }
2570: }
2571: if (c == NULL) {
1.51 markus 2572: /* Send refusal to the remote host. */
2573: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2574: packet_put_int(remote_id);
1.51 markus 2575: } else {
2576: /* Send a confirmation to the remote host. */
2577: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2578: packet_put_int(remote_id);
2579: packet_put_int(c->self);
1.51 markus 2580: }
1.113 markus 2581: packet_send();
1.72 markus 2582: }
2583:
2584: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2585: void
1.154 markus 2586: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2587: {
2588: int rchan = packet_get_int();
1.143 deraadt 2589: switch (type) {
1.72 markus 2590: case SSH_SMSG_AGENT_OPEN:
2591: error("Warning: ssh server tried agent forwarding.");
2592: break;
2593: case SSH_SMSG_X11_OPEN:
2594: error("Warning: ssh server tried X11 forwarding.");
2595: break;
2596: default:
1.154 markus 2597: error("deny_input_open: type %d", type);
1.72 markus 2598: break;
2599: }
2600: error("Warning: this is probably a break in attempt by a malicious server.");
2601: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2602: packet_put_int(rchan);
2603: packet_send();
1.1 deraadt 2604: }
2605:
1.27 markus 2606: /*
2607: * Requests forwarding of X11 connections, generates fake authentication
2608: * data, and enables authentication spoofing.
1.121 markus 2609: * This should be called in the client only.
1.27 markus 2610: */
1.49 markus 2611: void
1.51 markus 2612: x11_request_forwarding_with_spoofing(int client_session_id,
2613: const char *proto, const char *data)
1.1 deraadt 2614: {
1.77 markus 2615: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2616: u_int i, value, len;
1.25 markus 2617: char *new_data;
2618: int screen_number;
2619: const char *cp;
2620: u_int32_t rand = 0;
2621:
2622: cp = getenv("DISPLAY");
2623: if (cp)
2624: cp = strchr(cp, ':');
2625: if (cp)
2626: cp = strchr(cp, '.');
2627: if (cp)
2628: screen_number = atoi(cp + 1);
2629: else
2630: screen_number = 0;
2631:
2632: /* Save protocol name. */
2633: x11_saved_proto = xstrdup(proto);
2634:
1.27 markus 2635: /*
2636: * Extract real authentication data and generate fake data of the
2637: * same length.
2638: */
1.25 markus 2639: x11_saved_data = xmalloc(data_len);
2640: x11_fake_data = xmalloc(data_len);
2641: for (i = 0; i < data_len; i++) {
2642: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2643: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2644: if (i % 4 == 0)
2645: rand = arc4random();
2646: x11_saved_data[i] = value;
2647: x11_fake_data[i] = rand & 0xff;
2648: rand >>= 8;
2649: }
2650: x11_saved_data_len = data_len;
2651: x11_fake_data_len = data_len;
2652:
2653: /* Convert the fake data into hex. */
1.90 markus 2654: len = 2 * data_len + 1;
2655: new_data = xmalloc(len);
1.25 markus 2656: for (i = 0; i < data_len; i++)
1.90 markus 2657: snprintf(new_data + 2 * i, len - 2 * i,
2658: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2659:
2660: /* Send the request packet. */
1.51 markus 2661: if (compat20) {
2662: channel_request_start(client_session_id, "x11-req", 0);
2663: packet_put_char(0); /* XXX bool single connection */
2664: } else {
2665: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2666: }
2667: packet_put_cstring(proto);
2668: packet_put_cstring(new_data);
1.25 markus 2669: packet_put_int(screen_number);
2670: packet_send();
2671: packet_write_wait();
2672: xfree(new_data);
1.1 deraadt 2673: }
2674:
1.121 markus 2675:
2676: /* -- agent forwarding */
2677:
1.1 deraadt 2678: /* Sends a message to the server to request authentication fd forwarding. */
2679:
1.49 markus 2680: void
1.142 itojun 2681: auth_request_forwarding(void)
1.1 deraadt 2682: {
1.25 markus 2683: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2684: packet_send();
2685: packet_write_wait();
1.1 deraadt 2686: }
2687:
1.27 markus 2688: /*
2689: * Returns the name of the forwarded authentication socket. Returns NULL if
2690: * there is no forwarded authentication socket. The returned value points to
2691: * a static buffer.
2692: */
1.1 deraadt 2693:
1.25 markus 2694: char *
1.142 itojun 2695: auth_get_socket_name(void)
1.1 deraadt 2696: {
1.121 markus 2697: return auth_sock_name;
1.1 deraadt 2698: }
2699:
1.12 markus 2700: /* removes the agent forwarding socket */
2701:
1.49 markus 2702: void
1.123 markus 2703: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2704: {
1.123 markus 2705: struct passwd *pw = _pw;
2706:
1.122 markus 2707: if (auth_sock_name) {
1.123 markus 2708: temporarily_use_uid(pw);
1.122 markus 2709: unlink(auth_sock_name);
2710: rmdir(auth_sock_dir);
2711: auth_sock_name = NULL;
1.123 markus 2712: restore_uid();
1.122 markus 2713: }
1.12 markus 2714: }
2715:
1.27 markus 2716: /*
1.59 markus 2717: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2718: * This starts forwarding authentication requests.
2719: */
1.1 deraadt 2720:
1.59 markus 2721: int
1.25 markus 2722: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2723: {
1.113 markus 2724: Channel *nc;
2725: int sock;
1.25 markus 2726: struct sockaddr_un sunaddr;
2727:
1.121 markus 2728: if (auth_get_socket_name() != NULL) {
2729: error("authentication forwarding requested twice.");
2730: return 0;
2731: }
1.25 markus 2732:
2733: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2734: temporarily_use_uid(pw);
1.25 markus 2735:
2736: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2737: auth_sock_name = xmalloc(MAXPATHLEN);
2738: auth_sock_dir = xmalloc(MAXPATHLEN);
2739: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2740:
2741: /* Create private directory for socket */
1.121 markus 2742: if (mkdtemp(auth_sock_dir) == NULL) {
2743: packet_send_debug("Agent forwarding disabled: "
2744: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2745: restore_uid();
1.121 markus 2746: xfree(auth_sock_name);
2747: xfree(auth_sock_dir);
2748: auth_sock_name = NULL;
2749: auth_sock_dir = NULL;
1.59 markus 2750: return 0;
2751: }
1.121 markus 2752: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2753: auth_sock_dir, (int) getpid());
1.25 markus 2754:
1.122 markus 2755: /* delete agent socket on fatal() */
1.123 markus 2756: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2757:
1.25 markus 2758: /* Create the socket. */
2759: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2760: if (sock < 0)
2761: packet_disconnect("socket: %.100s", strerror(errno));
2762:
2763: /* Bind it to the name. */
2764: memset(&sunaddr, 0, sizeof(sunaddr));
2765: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2766: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2767:
2768: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2769: packet_disconnect("bind: %.100s", strerror(errno));
2770:
2771: /* Restore the privileged uid. */
2772: restore_uid();
2773:
2774: /* Start listening on the socket. */
2775: if (listen(sock, 5) < 0)
2776: packet_disconnect("listen: %.100s", strerror(errno));
2777:
2778: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2779: nc = channel_new("auth socket",
1.73 markus 2780: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2781: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2782: 0, xstrdup("auth socket"), 1);
1.113 markus 2783: if (nc == NULL) {
2784: error("auth_input_request_forwarding: channel_new failed");
1.123 markus 2785: auth_sock_cleanup_proc(pw);
1.124 markus 2786: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
1.113 markus 2787: close(sock);
2788: return 0;
2789: }
1.121 markus 2790: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2791: return 1;
1.1 deraadt 2792: }
2793:
2794: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2795:
1.49 markus 2796: void
1.154 markus 2797: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2798: {
1.113 markus 2799: Channel *c = NULL;
2800: int remote_id, sock;
1.121 markus 2801: char *name;
1.41 markus 2802:
1.25 markus 2803: /* Read the remote channel number from the message. */
1.113 markus 2804: remote_id = packet_get_int();
1.152 markus 2805: packet_check_eom();
1.25 markus 2806:
1.27 markus 2807: /*
2808: * Get a connection to the local authentication agent (this may again
2809: * get forwarded).
2810: */
1.25 markus 2811: sock = ssh_get_authentication_socket();
2812:
1.27 markus 2813: /*
2814: * If we could not connect the agent, send an error message back to
2815: * the server. This should never happen unless the agent dies,
2816: * because authentication forwarding is only enabled if we have an
2817: * agent.
2818: */
1.113 markus 2819: if (sock >= 0) {
1.121 markus 2820: name = xstrdup("authentication agent connection");
2821: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2822: -1, 0, 0, 0, name, 1);
1.113 markus 2823: if (c == NULL) {
2824: error("auth_input_open_request: channel_new failed");
1.121 markus 2825: xfree(name);
1.113 markus 2826: close(sock);
2827: } else {
2828: c->remote_id = remote_id;
1.133 markus 2829: c->force_drain = 1;
1.113 markus 2830: }
2831: }
2832: if (c == NULL) {
1.25 markus 2833: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2834: packet_put_int(remote_id);
2835: } else {
2836: /* Send a confirmation to the remote host. */
2837: debug("Forwarding authentication connection.");
2838: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2839: packet_put_int(remote_id);
2840: packet_put_int(c->self);
1.25 markus 2841: }
2842: packet_send();
1.1 deraadt 2843: }