Annotation of src/usr.bin/ssh/channels.c, Revision 1.169
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"
1.169 ! stevesk 42: RCSID("$OpenBSD: channels.c,v 1.168 2002/02/14 23:27:59 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,
1.168 markus 647: int extusage, int nonblock, u_int window_max)
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;
1.168 markus 654: c->local_window = c->local_window_max = window_max;
1.121 markus 655: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
656: packet_put_int(c->remote_id);
657: packet_put_int(c->local_window);
658: packet_send();
1.1 deraadt 659: }
660:
1.27 markus 661: /*
1.41 markus 662: * 'channel_pre*' are called just before select() to add any bits relevant to
663: * channels in the select bitmasks.
664: */
665: /*
666: * 'channel_post*': perform any appropriate operations for channels which
667: * have events pending.
1.27 markus 668: */
1.41 markus 669: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
670: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
671: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
672:
1.127 itojun 673: static void
1.41 markus 674: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
675: {
676: FD_SET(c->sock, readset);
677: }
678:
1.127 itojun 679: static void
1.75 markus 680: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
681: {
682: debug3("channel %d: waiting for connection", c->self);
683: FD_SET(c->sock, writeset);
684: }
685:
1.127 itojun 686: static void
1.41 markus 687: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
688: {
689: if (buffer_len(&c->input) < packet_get_maxsize())
690: FD_SET(c->sock, readset);
691: if (buffer_len(&c->output) > 0)
692: FD_SET(c->sock, writeset);
693: }
1.1 deraadt 694:
1.127 itojun 695: static void
1.157 markus 696: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 697: {
1.157 markus 698: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 699:
1.44 markus 700: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 701: limit > 0 &&
702: buffer_len(&c->input) < limit)
1.44 markus 703: FD_SET(c->rfd, readset);
704: if (c->ostate == CHAN_OUTPUT_OPEN ||
705: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
706: if (buffer_len(&c->output) > 0) {
707: FD_SET(c->wfd, writeset);
708: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
709: chan_obuf_empty(c);
710: }
711: }
712: /** XXX check close conditions, too */
1.157 markus 713: if (compat20 && c->efd != -1) {
1.44 markus 714: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
715: buffer_len(&c->extended) > 0)
716: FD_SET(c->efd, writeset);
717: else if (c->extended_usage == CHAN_EXTENDED_READ &&
718: buffer_len(&c->extended) < c->remote_window)
719: FD_SET(c->efd, readset);
720: }
721: }
722:
1.127 itojun 723: static void
1.41 markus 724: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
725: {
726: if (buffer_len(&c->input) == 0) {
727: packet_start(SSH_MSG_CHANNEL_CLOSE);
728: packet_put_int(c->remote_id);
729: packet_send();
730: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 731: debug("channel %d: closing after input drain.", c->self);
1.41 markus 732: }
733: }
734:
1.127 itojun 735: static void
1.41 markus 736: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
737: {
738: if (buffer_len(&c->output) == 0)
1.113 markus 739: chan_mark_dead(c);
1.49 markus 740: else
1.41 markus 741: FD_SET(c->sock, writeset);
742: }
743:
744: /*
745: * This is a special state for X11 authentication spoofing. An opened X11
746: * connection (when authentication spoofing is being done) remains in this
747: * state until the first packet has been completely read. The authentication
748: * data in that packet is then substituted by the real data if it matches the
749: * fake data, and the channel is put into normal mode.
1.51 markus 750: * XXX All this happens at the client side.
1.121 markus 751: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 752: */
1.127 itojun 753: static int
1.121 markus 754: x11_open_helper(Buffer *b)
1.1 deraadt 755: {
1.77 markus 756: u_char *ucp;
757: u_int proto_len, data_len;
1.25 markus 758:
1.41 markus 759: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 760: if (buffer_len(b) < 12)
1.41 markus 761: return 0;
762:
763: /* Parse the lengths of variable-length fields. */
1.155 stevesk 764: ucp = buffer_ptr(b);
1.41 markus 765: if (ucp[0] == 0x42) { /* Byte order MSB first. */
766: proto_len = 256 * ucp[6] + ucp[7];
767: data_len = 256 * ucp[8] + ucp[9];
768: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
769: proto_len = ucp[6] + 256 * ucp[7];
770: data_len = ucp[8] + 256 * ucp[9];
771: } else {
772: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 773: ucp[0]);
1.41 markus 774: return -1;
775: }
776:
777: /* Check if the whole packet is in buffer. */
1.121 markus 778: if (buffer_len(b) <
1.41 markus 779: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
780: return 0;
781:
782: /* Check if authentication protocol matches. */
783: if (proto_len != strlen(x11_saved_proto) ||
784: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
785: debug("X11 connection uses different authentication protocol.");
786: return -1;
787: }
788: /* Check if authentication data matches our fake data. */
789: if (data_len != x11_fake_data_len ||
790: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
791: x11_fake_data, x11_fake_data_len) != 0) {
792: debug("X11 auth data does not match fake data.");
793: return -1;
794: }
795: /* Check fake data length */
796: if (x11_fake_data_len != x11_saved_data_len) {
797: error("X11 fake_data_len %d != saved_data_len %d",
798: x11_fake_data_len, x11_saved_data_len);
799: return -1;
800: }
801: /*
802: * Received authentication protocol and data match
803: * our fake data. Substitute the fake data with real
804: * data.
805: */
806: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
807: x11_saved_data, x11_saved_data_len);
808: return 1;
809: }
810:
1.127 itojun 811: static void
1.41 markus 812: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
813: {
1.121 markus 814: int ret = x11_open_helper(&c->output);
1.41 markus 815: if (ret == 1) {
816: /* Start normal processing for the channel. */
817: c->type = SSH_CHANNEL_OPEN;
1.47 markus 818: channel_pre_open_13(c, readset, writeset);
1.41 markus 819: } else if (ret == -1) {
820: /*
821: * We have received an X11 connection that has bad
822: * authentication information.
823: */
1.98 millert 824: log("X11 connection rejected because of wrong authentication.");
1.41 markus 825: buffer_clear(&c->input);
826: buffer_clear(&c->output);
1.132 markus 827: channel_close_fd(&c->sock);
1.41 markus 828: c->sock = -1;
829: c->type = SSH_CHANNEL_CLOSED;
830: packet_start(SSH_MSG_CHANNEL_CLOSE);
831: packet_put_int(c->remote_id);
832: packet_send();
833: }
834: }
1.25 markus 835:
1.127 itojun 836: static void
1.51 markus 837: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 838: {
1.121 markus 839: int ret = x11_open_helper(&c->output);
1.133 markus 840:
841: /* c->force_drain = 1; */
842:
1.41 markus 843: if (ret == 1) {
844: c->type = SSH_CHANNEL_OPEN;
1.157 markus 845: channel_pre_open(c, readset, writeset);
1.41 markus 846: } else if (ret == -1) {
1.156 markus 847: log("X11 connection rejected because of wrong authentication.");
1.41 markus 848: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 849: chan_read_failed(c);
850: buffer_clear(&c->input);
851: chan_ibuf_empty(c);
852: buffer_clear(&c->output);
853: /* for proto v1, the peer will send an IEOF */
854: if (compat20)
855: chan_write_failed(c);
856: else
857: c->type = SSH_CHANNEL_OPEN;
1.41 markus 858: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
859: }
860: }
1.25 markus 861:
1.104 markus 862: /* try to decode a socks4 header */
1.127 itojun 863: static int
1.104 markus 864: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 865: {
866: u_char *p, *host;
1.109 markus 867: int len, have, i, found;
1.148 deraadt 868: char username[256];
1.103 markus 869: struct {
870: u_int8_t version;
871: u_int8_t command;
872: u_int16_t dest_port;
1.104 markus 873: struct in_addr dest_addr;
1.103 markus 874: } s4_req, s4_rsp;
875:
1.104 markus 876: debug2("channel %d: decode socks4", c->self);
1.109 markus 877:
878: have = buffer_len(&c->input);
879: len = sizeof(s4_req);
880: if (have < len)
881: return 0;
882: p = buffer_ptr(&c->input);
883: for (found = 0, i = len; i < have; i++) {
884: if (p[i] == '\0') {
885: found = 1;
886: break;
887: }
888: if (i > 1024) {
889: /* the peer is probably sending garbage */
890: debug("channel %d: decode socks4: too long",
891: c->self);
892: return -1;
893: }
894: }
895: if (!found)
896: return 0;
1.103 markus 897: buffer_get(&c->input, (char *)&s4_req.version, 1);
898: buffer_get(&c->input, (char *)&s4_req.command, 1);
899: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 900: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 901: have = buffer_len(&c->input);
1.103 markus 902: p = buffer_ptr(&c->input);
903: len = strlen(p);
1.106 markus 904: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 905: if (len > have)
1.104 markus 906: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 907: c->self, len, have);
908: strlcpy(username, p, sizeof(username));
909: buffer_consume(&c->input, len);
910: buffer_consume(&c->input, 1); /* trailing '\0' */
911:
1.104 markus 912: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 913: strlcpy(c->path, host, sizeof(c->path));
914: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 915:
1.106 markus 916: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
917: c->self, host, c->host_port, s4_req.command);
1.103 markus 918:
1.104 markus 919: if (s4_req.command != 1) {
920: debug("channel %d: cannot handle: socks4 cn %d",
921: c->self, s4_req.command);
922: return -1;
1.103 markus 923: }
1.104 markus 924: s4_rsp.version = 0; /* vn: 0 for reply */
925: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 926: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 927: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 928: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 929: return 1;
930: }
931:
932: /* dynamic port forwarding */
1.127 itojun 933: static void
1.104 markus 934: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
935: {
936: u_char *p;
937: int have, ret;
1.103 markus 938:
1.104 markus 939: have = buffer_len(&c->input);
1.137 markus 940: c->delayed = 0;
1.104 markus 941: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 942: /* buffer_dump(&c->input); */
1.104 markus 943: /* check if the fixed size part of the packet is in buffer. */
944: if (have < 4) {
945: /* need more */
946: FD_SET(c->sock, readset);
947: return;
948: }
949: /* try to guess the protocol */
950: p = buffer_ptr(&c->input);
951: switch (p[0]) {
952: case 0x04:
953: ret = channel_decode_socks4(c, readset, writeset);
954: break;
955: default:
956: ret = -1;
957: break;
958: }
959: if (ret < 0) {
1.113 markus 960: chan_mark_dead(c);
1.104 markus 961: } else if (ret == 0) {
962: debug2("channel %d: pre_dynamic: need more", c->self);
963: /* need more */
964: FD_SET(c->sock, readset);
965: } else {
966: /* switch to the next state */
967: c->type = SSH_CHANNEL_OPENING;
968: port_open_helper(c, "direct-tcpip");
969: }
1.103 markus 970: }
971:
1.41 markus 972: /* This is our fake X11 server socket. */
1.127 itojun 973: static void
1.41 markus 974: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
975: {
1.113 markus 976: Channel *nc;
1.41 markus 977: struct sockaddr addr;
1.162 stevesk 978: int newsock;
1.41 markus 979: socklen_t addrlen;
1.85 markus 980: char buf[16384], *remote_ipaddr;
1.51 markus 981: int remote_port;
1.25 markus 982:
1.41 markus 983: if (FD_ISSET(c->sock, readset)) {
984: debug("X11 connection requested.");
985: addrlen = sizeof(addr);
986: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 987: if (c->single_connection) {
988: debug("single_connection: closing X11 listener.");
989: channel_close_fd(&c->sock);
990: chan_mark_dead(c);
991: }
1.41 markus 992: if (newsock < 0) {
993: error("accept: %.100s", strerror(errno));
994: return;
995: }
1.162 stevesk 996: set_nodelay(newsock);
1.85 markus 997: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 998: remote_port = get_peer_port(newsock);
1.41 markus 999: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1000: remote_ipaddr, remote_port);
1.51 markus 1001:
1.113 markus 1002: nc = channel_new("accepted x11 socket",
1.51 markus 1003: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1004: c->local_window_max, c->local_maxpacket,
1.71 markus 1005: 0, xstrdup(buf), 1);
1.51 markus 1006: if (compat20) {
1007: packet_start(SSH2_MSG_CHANNEL_OPEN);
1008: packet_put_cstring("x11");
1.113 markus 1009: packet_put_int(nc->self);
1.149 markus 1010: packet_put_int(nc->local_window_max);
1011: packet_put_int(nc->local_maxpacket);
1.85 markus 1012: /* originator ipaddr and port */
1013: packet_put_cstring(remote_ipaddr);
1.57 markus 1014: if (datafellows & SSH_BUG_X11FWD) {
1015: debug("ssh2 x11 bug compat mode");
1016: } else {
1017: packet_put_int(remote_port);
1018: }
1.51 markus 1019: packet_send();
1020: } else {
1021: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1022: packet_put_int(nc->self);
1.121 markus 1023: if (packet_get_protocol_flags() &
1024: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1025: packet_put_cstring(buf);
1.51 markus 1026: packet_send();
1027: }
1.85 markus 1028: xfree(remote_ipaddr);
1.41 markus 1029: }
1030: }
1.25 markus 1031:
1.127 itojun 1032: static void
1.103 markus 1033: port_open_helper(Channel *c, char *rtype)
1034: {
1035: int direct;
1036: char buf[1024];
1037: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1038: u_short remote_port = get_peer_port(c->sock);
1039:
1040: direct = (strcmp(rtype, "direct-tcpip") == 0);
1041:
1042: snprintf(buf, sizeof buf,
1043: "%s: listening port %d for %.100s port %d, "
1044: "connect from %.200s port %d",
1045: rtype, c->listening_port, c->path, c->host_port,
1046: remote_ipaddr, remote_port);
1047:
1048: xfree(c->remote_name);
1049: c->remote_name = xstrdup(buf);
1050:
1051: if (compat20) {
1052: packet_start(SSH2_MSG_CHANNEL_OPEN);
1053: packet_put_cstring(rtype);
1054: packet_put_int(c->self);
1055: packet_put_int(c->local_window_max);
1056: packet_put_int(c->local_maxpacket);
1057: if (direct) {
1058: /* target host, port */
1059: packet_put_cstring(c->path);
1060: packet_put_int(c->host_port);
1061: } else {
1062: /* listen address, port */
1063: packet_put_cstring(c->path);
1064: packet_put_int(c->listening_port);
1065: }
1066: /* originator host and port */
1067: packet_put_cstring(remote_ipaddr);
1068: packet_put_int(remote_port);
1069: packet_send();
1070: } else {
1071: packet_start(SSH_MSG_PORT_OPEN);
1072: packet_put_int(c->self);
1073: packet_put_cstring(c->path);
1074: packet_put_int(c->host_port);
1.121 markus 1075: if (packet_get_protocol_flags() &
1076: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1077: packet_put_cstring(c->remote_name);
1078: packet_send();
1079: }
1080: xfree(remote_ipaddr);
1081: }
1082:
1.41 markus 1083: /*
1084: * This socket is listening for connections to a forwarded TCP/IP port.
1085: */
1.127 itojun 1086: static void
1.41 markus 1087: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1088: {
1.103 markus 1089: Channel *nc;
1.41 markus 1090: struct sockaddr addr;
1.113 markus 1091: int newsock, nextstate;
1.41 markus 1092: socklen_t addrlen;
1.103 markus 1093: char *rtype;
1.73 markus 1094:
1.41 markus 1095: if (FD_ISSET(c->sock, readset)) {
1096: debug("Connection to port %d forwarding "
1097: "to %.100s port %d requested.",
1098: c->listening_port, c->path, c->host_port);
1.103 markus 1099:
1.137 markus 1100: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1101: nextstate = SSH_CHANNEL_OPENING;
1102: rtype = "forwarded-tcpip";
1103: } else {
1104: if (c->host_port == 0) {
1105: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1106: rtype = "dynamic-tcpip";
1.137 markus 1107: } else {
1108: nextstate = SSH_CHANNEL_OPENING;
1109: rtype = "direct-tcpip";
1110: }
1111: }
1.103 markus 1112:
1.41 markus 1113: addrlen = sizeof(addr);
1114: newsock = accept(c->sock, &addr, &addrlen);
1115: if (newsock < 0) {
1116: error("accept: %.100s", strerror(errno));
1117: return;
1118: }
1.169 ! stevesk 1119: set_nodelay(newsock);
1.113 markus 1120: nc = channel_new(rtype,
1.103 markus 1121: nextstate, newsock, newsock, -1,
1.41 markus 1122: c->local_window_max, c->local_maxpacket,
1.103 markus 1123: 0, xstrdup(rtype), 1);
1124: nc->listening_port = c->listening_port;
1125: nc->host_port = c->host_port;
1126: strlcpy(nc->path, c->path, sizeof(nc->path));
1127:
1.137 markus 1128: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1129: /*
1130: * do not call the channel_post handler until
1131: * this flag has been reset by a pre-handler.
1132: * otherwise the FD_ISSET calls might overflow
1133: */
1134: nc->delayed = 1;
1135: } else {
1.103 markus 1136: port_open_helper(nc, rtype);
1.137 markus 1137: }
1.41 markus 1138: }
1139: }
1.25 markus 1140:
1.41 markus 1141: /*
1142: * This is the authentication agent socket listening for connections from
1143: * clients.
1144: */
1.127 itojun 1145: static void
1.41 markus 1146: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1147: {
1.113 markus 1148: Channel *nc;
1.121 markus 1149: char *name;
1.113 markus 1150: int newsock;
1.41 markus 1151: struct sockaddr addr;
1152: socklen_t addrlen;
1.25 markus 1153:
1.41 markus 1154: if (FD_ISSET(c->sock, readset)) {
1155: addrlen = sizeof(addr);
1156: newsock = accept(c->sock, &addr, &addrlen);
1157: if (newsock < 0) {
1158: error("accept from auth socket: %.100s", strerror(errno));
1159: return;
1160: }
1.121 markus 1161: name = xstrdup("accepted auth socket");
1.113 markus 1162: nc = channel_new("accepted auth socket",
1.73 markus 1163: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1164: c->local_window_max, c->local_maxpacket,
1.121 markus 1165: 0, name, 1);
1.73 markus 1166: if (compat20) {
1167: packet_start(SSH2_MSG_CHANNEL_OPEN);
1168: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1169: packet_put_int(nc->self);
1.73 markus 1170: packet_put_int(c->local_window_max);
1171: packet_put_int(c->local_maxpacket);
1172: } else {
1173: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1174: packet_put_int(nc->self);
1.73 markus 1175: }
1.41 markus 1176: packet_send();
1177: }
1178: }
1.25 markus 1179:
1.127 itojun 1180: static void
1.75 markus 1181: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1182: {
1.114 markus 1183: int err = 0;
1.129 stevesk 1184: socklen_t sz = sizeof(err);
1.114 markus 1185:
1.75 markus 1186: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1187: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1188: &sz) < 0) {
1189: err = errno;
1190: error("getsockopt SO_ERROR failed");
1191: }
1192: if (err == 0) {
1193: debug("channel %d: connected", c->self);
1194: c->type = SSH_CHANNEL_OPEN;
1195: if (compat20) {
1196: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1197: packet_put_int(c->remote_id);
1198: packet_put_int(c->self);
1199: packet_put_int(c->local_window);
1200: packet_put_int(c->local_maxpacket);
1201: } else {
1202: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1203: packet_put_int(c->remote_id);
1204: packet_put_int(c->self);
1205: }
1.75 markus 1206: } else {
1.114 markus 1207: debug("channel %d: not connected: %s",
1208: c->self, strerror(err));
1209: if (compat20) {
1210: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1211: packet_put_int(c->remote_id);
1212: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1213: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1214: packet_put_cstring(strerror(err));
1215: packet_put_cstring("");
1216: }
1.75 markus 1217: } else {
1.114 markus 1218: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1219: packet_put_int(c->remote_id);
1.75 markus 1220: }
1.114 markus 1221: chan_mark_dead(c);
1.75 markus 1222: }
1.114 markus 1223: packet_send();
1.75 markus 1224: }
1225: }
1226:
1.127 itojun 1227: static int
1.41 markus 1228: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1229: {
1230: char buf[16*1024];
1231: int len;
1.25 markus 1232:
1.118 markus 1233: if (c->rfd != -1 &&
1.41 markus 1234: FD_ISSET(c->rfd, readset)) {
1235: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1236: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1237: return 1;
1.41 markus 1238: if (len <= 0) {
1.51 markus 1239: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1240: c->self, c->rfd, len);
1.104 markus 1241: if (c->type != SSH_CHANNEL_OPEN) {
1242: debug("channel %d: not open", c->self);
1.113 markus 1243: chan_mark_dead(c);
1.103 markus 1244: return -1;
1.104 markus 1245: } else if (compat13) {
1.158 markus 1246: buffer_clear(&c->output);
1.41 markus 1247: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1248: debug("channel %d: input draining.", c->self);
1.25 markus 1249: } else {
1.41 markus 1250: chan_read_failed(c);
1.25 markus 1251: }
1.41 markus 1252: return -1;
1253: }
1.143 deraadt 1254: if (c->input_filter != NULL) {
1.66 markus 1255: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1256: debug("channel %d: filter stops", c->self);
1.65 markus 1257: chan_read_failed(c);
1258: }
1259: } else {
1260: buffer_append(&c->input, buf, len);
1261: }
1.41 markus 1262: }
1263: return 1;
1264: }
1.127 itojun 1265: static int
1.41 markus 1266: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1267: {
1.95 markus 1268: struct termios tio;
1.134 markus 1269: u_char *data;
1270: u_int dlen;
1.41 markus 1271: int len;
1.25 markus 1272:
1.41 markus 1273: /* Send buffered output data to the socket. */
1.118 markus 1274: if (c->wfd != -1 &&
1.41 markus 1275: FD_ISSET(c->wfd, writeset) &&
1276: buffer_len(&c->output) > 0) {
1.134 markus 1277: data = buffer_ptr(&c->output);
1278: dlen = buffer_len(&c->output);
1279: len = write(c->wfd, data, dlen);
1.53 markus 1280: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1281: return 1;
1.41 markus 1282: if (len <= 0) {
1.104 markus 1283: if (c->type != SSH_CHANNEL_OPEN) {
1284: debug("channel %d: not open", c->self);
1.113 markus 1285: chan_mark_dead(c);
1.104 markus 1286: return -1;
1287: } else if (compat13) {
1.158 markus 1288: buffer_clear(&c->output);
1.121 markus 1289: debug("channel %d: input draining.", c->self);
1.41 markus 1290: c->type = SSH_CHANNEL_INPUT_DRAINING;
1291: } else {
1292: chan_write_failed(c);
1293: }
1294: return -1;
1.91 markus 1295: }
1.134 markus 1296: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1297: if (tcgetattr(c->wfd, &tio) == 0 &&
1298: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1299: /*
1300: * Simulate echo to reduce the impact of
1.96 markus 1301: * traffic analysis. We need to match the
1.95 markus 1302: * size of a SSH2_MSG_CHANNEL_DATA message
1303: * (4 byte channel id + data)
1.91 markus 1304: */
1.95 markus 1305: packet_send_ignore(4 + len);
1.91 markus 1306: packet_send();
1307: }
1.25 markus 1308: }
1.41 markus 1309: buffer_consume(&c->output, len);
1.44 markus 1310: if (compat20 && len > 0) {
1311: c->local_consumed += len;
1312: }
1313: }
1314: return 1;
1315: }
1.127 itojun 1316: static int
1.44 markus 1317: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1318: {
1319: char buf[16*1024];
1320: int len;
1321:
1.45 markus 1322: /** XXX handle drain efd, too */
1.44 markus 1323: if (c->efd != -1) {
1324: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1325: FD_ISSET(c->efd, writeset) &&
1326: buffer_len(&c->extended) > 0) {
1327: len = write(c->efd, buffer_ptr(&c->extended),
1328: buffer_len(&c->extended));
1.70 markus 1329: debug2("channel %d: written %d to efd %d",
1.44 markus 1330: c->self, len, c->efd);
1.93 markus 1331: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1332: return 1;
1333: if (len <= 0) {
1334: debug2("channel %d: closing write-efd %d",
1335: c->self, c->efd);
1.132 markus 1336: channel_close_fd(&c->efd);
1.93 markus 1337: } else {
1.44 markus 1338: buffer_consume(&c->extended, len);
1339: c->local_consumed += len;
1340: }
1341: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1342: FD_ISSET(c->efd, readset)) {
1343: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1344: debug2("channel %d: read %d from efd %d",
1.148 deraadt 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 read-efd %d",
1.45 markus 1350: c->self, c->efd);
1.132 markus 1351: channel_close_fd(&c->efd);
1.93 markus 1352: } else {
1.44 markus 1353: buffer_append(&c->extended, buf, len);
1.93 markus 1354: }
1.44 markus 1355: }
1356: }
1357: return 1;
1358: }
1.127 itojun 1359: static int
1.93 markus 1360: channel_check_window(Channel *c)
1.44 markus 1361: {
1.104 markus 1362: if (c->type == SSH_CHANNEL_OPEN &&
1363: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1364: c->local_window < c->local_window_max/2 &&
1365: c->local_consumed > 0) {
1366: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1367: packet_put_int(c->remote_id);
1368: packet_put_int(c->local_consumed);
1369: packet_send();
1.70 markus 1370: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1371: c->self, c->local_window,
1372: c->local_consumed);
1373: c->local_window += c->local_consumed;
1374: c->local_consumed = 0;
1.1 deraadt 1375: }
1.41 markus 1376: return 1;
1.1 deraadt 1377: }
1378:
1.127 itojun 1379: static void
1.157 markus 1380: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1381: {
1.137 markus 1382: if (c->delayed)
1383: return;
1.41 markus 1384: channel_handle_rfd(c, readset, writeset);
1385: channel_handle_wfd(c, readset, writeset);
1.157 markus 1386: if (!compat20)
1.137 markus 1387: return;
1.44 markus 1388: channel_handle_efd(c, readset, writeset);
1.93 markus 1389: channel_check_window(c);
1.44 markus 1390: }
1391:
1.127 itojun 1392: static void
1.41 markus 1393: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1394: {
1.41 markus 1395: int len;
1396: /* Send buffered output data to the socket. */
1397: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1398: len = write(c->sock, buffer_ptr(&c->output),
1399: buffer_len(&c->output));
1400: if (len <= 0)
1.158 markus 1401: buffer_clear(&c->output);
1.41 markus 1402: else
1403: buffer_consume(&c->output, len);
1404: }
1405: }
1.25 markus 1406:
1.127 itojun 1407: static void
1.44 markus 1408: channel_handler_init_20(void)
1409: {
1.157 markus 1410: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1411: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1412: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1413: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1414: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1415: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1416: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1417: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1418:
1.157 markus 1419: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1420: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1421: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1422: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1423: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1424: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1425: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1426: }
1427:
1.127 itojun 1428: static void
1.41 markus 1429: channel_handler_init_13(void)
1430: {
1431: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1432: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1433: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1434: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1435: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1436: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1437: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1438: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1439: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1440:
1.157 markus 1441: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1442: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1443: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1444: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1445: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1446: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1447: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1448: }
1.25 markus 1449:
1.127 itojun 1450: static void
1.41 markus 1451: channel_handler_init_15(void)
1452: {
1.157 markus 1453: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1454: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1455: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1456: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1457: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1458: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1459: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1460:
1.41 markus 1461: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1462: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1463: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1464: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1465: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1466: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1467: }
1.27 markus 1468:
1.127 itojun 1469: static void
1.41 markus 1470: channel_handler_init(void)
1471: {
1472: int i;
1.148 deraadt 1473: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1474: channel_pre[i] = NULL;
1475: channel_post[i] = NULL;
1476: }
1.44 markus 1477: if (compat20)
1478: channel_handler_init_20();
1479: else if (compat13)
1.41 markus 1480: channel_handler_init_13();
1481: else
1482: channel_handler_init_15();
1483: }
1.25 markus 1484:
1.140 markus 1485: /* gc dead channels */
1486: static void
1487: channel_garbage_collect(Channel *c)
1488: {
1489: if (c == NULL)
1490: return;
1491: if (c->detach_user != NULL) {
1492: if (!chan_is_dead(c, 0))
1493: return;
1494: debug("channel %d: gc: notify user", c->self);
1495: c->detach_user(c->self, NULL);
1496: /* if we still have a callback */
1497: if (c->detach_user != NULL)
1498: return;
1499: debug("channel %d: gc: user detached", c->self);
1500: }
1501: if (!chan_is_dead(c, 1))
1502: return;
1503: debug("channel %d: garbage collecting", c->self);
1504: channel_free(c);
1505: }
1506:
1.127 itojun 1507: static void
1.41 markus 1508: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1509: {
1510: static int did_init = 0;
1511: int i;
1512: Channel *c;
1.25 markus 1513:
1.41 markus 1514: if (!did_init) {
1515: channel_handler_init();
1516: did_init = 1;
1517: }
1518: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1519: c = channels[i];
1520: if (c == NULL)
1.41 markus 1521: continue;
1.118 markus 1522: if (ftab[c->type] != NULL)
1523: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1524: channel_garbage_collect(c);
1.1 deraadt 1525: }
1526: }
1527:
1.121 markus 1528: /*
1529: * Allocate/update select bitmasks and add any bits relevant to channels in
1530: * select bitmasks.
1531: */
1.49 markus 1532: void
1.100 markus 1533: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1534: int *nallocp, int rekeying)
1.41 markus 1535: {
1.84 markus 1536: int n;
1537: u_int sz;
1538:
1539: n = MAX(*maxfdp, channel_max_fd);
1540:
1541: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1542: /* perhaps check sz < nalloc/2 and shrink? */
1543: if (*readsetp == NULL || sz > *nallocp) {
1544: *readsetp = xrealloc(*readsetp, sz);
1545: *writesetp = xrealloc(*writesetp, sz);
1546: *nallocp = sz;
1.84 markus 1547: }
1.132 markus 1548: *maxfdp = n;
1.84 markus 1549: memset(*readsetp, 0, sz);
1550: memset(*writesetp, 0, sz);
1551:
1.100 markus 1552: if (!rekeying)
1553: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1554: }
1555:
1.121 markus 1556: /*
1557: * After select, perform any appropriate operations for channels which have
1558: * events pending.
1559: */
1.49 markus 1560: void
1.41 markus 1561: channel_after_select(fd_set * readset, fd_set * writeset)
1562: {
1563: channel_handler(channel_post, readset, writeset);
1564: }
1565:
1.121 markus 1566:
1.84 markus 1567: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1568:
1.49 markus 1569: void
1.142 itojun 1570: channel_output_poll(void)
1.1 deraadt 1571: {
1.25 markus 1572: int len, i;
1.41 markus 1573: Channel *c;
1.1 deraadt 1574:
1.25 markus 1575: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1576: c = channels[i];
1577: if (c == NULL)
1578: continue;
1.37 markus 1579:
1.121 markus 1580: /*
1581: * We are only interested in channels that can have buffered
1582: * incoming data.
1583: */
1.37 markus 1584: if (compat13) {
1.41 markus 1585: if (c->type != SSH_CHANNEL_OPEN &&
1586: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1587: continue;
1588: } else {
1.41 markus 1589: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1590: continue;
1591: }
1.46 markus 1592: if (compat20 &&
1593: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1594: /* XXX is this true? */
1.140 markus 1595: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1596: continue;
1597: }
1.25 markus 1598:
1599: /* Get the amount of buffered data for this channel. */
1.93 markus 1600: if ((c->istate == CHAN_INPUT_OPEN ||
1601: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1602: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1603: /*
1604: * Send some data for the other side over the secure
1605: * connection.
1606: */
1.44 markus 1607: if (compat20) {
1608: if (len > c->remote_window)
1609: len = c->remote_window;
1610: if (len > c->remote_maxpacket)
1611: len = c->remote_maxpacket;
1.25 markus 1612: } else {
1.44 markus 1613: if (packet_is_interactive()) {
1614: if (len > 1024)
1615: len = 512;
1616: } else {
1617: /* Keep the packets at reasonable size. */
1618: if (len > packet_get_maxsize()/2)
1619: len = packet_get_maxsize()/2;
1620: }
1.25 markus 1621: }
1.41 markus 1622: if (len > 0) {
1.44 markus 1623: packet_start(compat20 ?
1624: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1625: packet_put_int(c->remote_id);
1626: packet_put_string(buffer_ptr(&c->input), len);
1627: packet_send();
1628: buffer_consume(&c->input, len);
1629: c->remote_window -= len;
1630: }
1631: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1632: if (compat13)
1633: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1634: /*
1635: * input-buffer is empty and read-socket shutdown:
1636: * tell peer, that we will not send more data: send IEOF
1637: */
1.41 markus 1638: chan_ibuf_empty(c);
1.25 markus 1639: }
1.44 markus 1640: /* Send extended data, i.e. stderr */
1641: if (compat20 &&
1642: c->remote_window > 0 &&
1643: (len = buffer_len(&c->extended)) > 0 &&
1644: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1645: debug2("channel %d: rwin %d elen %d euse %d",
1646: c->self, c->remote_window, buffer_len(&c->extended),
1647: c->extended_usage);
1.44 markus 1648: if (len > c->remote_window)
1649: len = c->remote_window;
1650: if (len > c->remote_maxpacket)
1651: len = c->remote_maxpacket;
1652: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1653: packet_put_int(c->remote_id);
1654: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1655: packet_put_string(buffer_ptr(&c->extended), len);
1656: packet_send();
1657: buffer_consume(&c->extended, len);
1658: c->remote_window -= len;
1.93 markus 1659: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1660: }
1.25 markus 1661: }
1.1 deraadt 1662: }
1663:
1.121 markus 1664:
1665: /* -- protocol input */
1.1 deraadt 1666:
1.49 markus 1667: void
1.154 markus 1668: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1669: {
1.37 markus 1670: int id;
1.25 markus 1671: char *data;
1.77 markus 1672: u_int data_len;
1.41 markus 1673: Channel *c;
1.25 markus 1674:
1675: /* Get the channel number and verify it. */
1.37 markus 1676: id = packet_get_int();
1.41 markus 1677: c = channel_lookup(id);
1678: if (c == NULL)
1.37 markus 1679: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1680:
1681: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1682: if (c->type != SSH_CHANNEL_OPEN &&
1683: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1684: return;
1685:
1686: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1687: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1688: return;
1689:
1690: /* Get the data. */
1691: data = packet_get_string(&data_len);
1.41 markus 1692:
1.143 deraadt 1693: if (compat20) {
1.44 markus 1694: if (data_len > c->local_maxpacket) {
1695: log("channel %d: rcvd big packet %d, maxpack %d",
1696: c->self, data_len, c->local_maxpacket);
1697: }
1698: if (data_len > c->local_window) {
1699: log("channel %d: rcvd too much data %d, win %d",
1700: c->self, data_len, c->local_window);
1701: xfree(data);
1702: return;
1703: }
1704: c->local_window -= data_len;
1705: }
1.152 markus 1706: packet_check_eom();
1.41 markus 1707: buffer_append(&c->output, data, data_len);
1.25 markus 1708: xfree(data);
1.1 deraadt 1709: }
1.121 markus 1710:
1.49 markus 1711: void
1.154 markus 1712: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1713: {
1714: int id;
1715: int tcode;
1716: char *data;
1.77 markus 1717: u_int data_len;
1.44 markus 1718: Channel *c;
1719:
1720: /* Get the channel number and verify it. */
1721: id = packet_get_int();
1722: c = channel_lookup(id);
1723:
1724: if (c == NULL)
1725: packet_disconnect("Received extended_data for bad channel %d.", id);
1726: if (c->type != SSH_CHANNEL_OPEN) {
1727: log("channel %d: ext data for non open", id);
1728: return;
1729: }
1730: tcode = packet_get_int();
1731: if (c->efd == -1 ||
1732: c->extended_usage != CHAN_EXTENDED_WRITE ||
1733: tcode != SSH2_EXTENDED_DATA_STDERR) {
1734: log("channel %d: bad ext data", c->self);
1735: return;
1736: }
1737: data = packet_get_string(&data_len);
1.152 markus 1738: packet_check_eom();
1.44 markus 1739: if (data_len > c->local_window) {
1740: log("channel %d: rcvd too much extended_data %d, win %d",
1741: c->self, data_len, c->local_window);
1742: xfree(data);
1743: return;
1744: }
1.70 markus 1745: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1746: c->local_window -= data_len;
1747: buffer_append(&c->extended, data, data_len);
1748: xfree(data);
1749: }
1750:
1.49 markus 1751: void
1.154 markus 1752: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1753: {
1754: int id;
1755: Channel *c;
1756:
1757: id = packet_get_int();
1.152 markus 1758: packet_check_eom();
1.41 markus 1759: c = channel_lookup(id);
1760: if (c == NULL)
1761: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1762: chan_rcvd_ieof(c);
1.133 markus 1763:
1764: /* XXX force input close */
1.156 markus 1765: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1766: debug("channel %d: FORCE input drain", c->self);
1767: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1768: if (buffer_len(&c->input) == 0)
1769: chan_ibuf_empty(c);
1.133 markus 1770: }
1771:
1.41 markus 1772: }
1.1 deraadt 1773:
1.49 markus 1774: void
1.154 markus 1775: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1776: {
1.41 markus 1777: int id;
1778: Channel *c;
1.1 deraadt 1779:
1.41 markus 1780: id = packet_get_int();
1.152 markus 1781: packet_check_eom();
1.41 markus 1782: c = channel_lookup(id);
1783: if (c == NULL)
1784: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1785:
1786: /*
1787: * Send a confirmation that we have closed the channel and no more
1788: * data is coming for it.
1789: */
1.25 markus 1790: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1791: packet_put_int(c->remote_id);
1.25 markus 1792: packet_send();
1793:
1.27 markus 1794: /*
1795: * If the channel is in closed state, we have sent a close request,
1796: * and the other side will eventually respond with a confirmation.
1797: * Thus, we cannot free the channel here, because then there would be
1798: * no-one to receive the confirmation. The channel gets freed when
1799: * the confirmation arrives.
1800: */
1.41 markus 1801: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1802: /*
1803: * Not a closed channel - mark it as draining, which will
1804: * cause it to be freed later.
1805: */
1.158 markus 1806: buffer_clear(&c->input);
1.41 markus 1807: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1808: }
1.1 deraadt 1809: }
1810:
1.41 markus 1811: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1812: void
1.154 markus 1813: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1814: {
1815: int id = packet_get_int();
1816: Channel *c = channel_lookup(id);
1.151 markus 1817:
1.152 markus 1818: packet_check_eom();
1.41 markus 1819: if (c == NULL)
1820: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1821: chan_rcvd_oclose(c);
1822: }
1.1 deraadt 1823:
1.49 markus 1824: void
1.154 markus 1825: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1826: {
1.41 markus 1827: int id = packet_get_int();
1828: Channel *c = channel_lookup(id);
1.1 deraadt 1829:
1.152 markus 1830: packet_check_eom();
1.41 markus 1831: if (c == NULL)
1832: packet_disconnect("Received close confirmation for "
1833: "out-of-range channel %d.", id);
1834: if (c->type != SSH_CHANNEL_CLOSED)
1835: packet_disconnect("Received close confirmation for "
1836: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1837: channel_free(c);
1.1 deraadt 1838: }
1839:
1.49 markus 1840: void
1.154 markus 1841: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1842: {
1.41 markus 1843: int id, remote_id;
1844: Channel *c;
1.1 deraadt 1845:
1.41 markus 1846: id = packet_get_int();
1847: c = channel_lookup(id);
1.25 markus 1848:
1.41 markus 1849: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1850: packet_disconnect("Received open confirmation for "
1851: "non-opening channel %d.", id);
1852: remote_id = packet_get_int();
1.27 markus 1853: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1854: c->remote_id = remote_id;
1855: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1856:
1857: if (compat20) {
1858: c->remote_window = packet_get_int();
1859: c->remote_maxpacket = packet_get_int();
1.165 markus 1860: if (c->confirm) {
1.70 markus 1861: debug2("callback start");
1.165 markus 1862: c->confirm(c->self, NULL);
1.70 markus 1863: debug2("callback done");
1.44 markus 1864: }
1865: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1866: c->remote_window, c->remote_maxpacket);
1867: }
1.152 markus 1868: packet_check_eom();
1.1 deraadt 1869: }
1870:
1.127 itojun 1871: static char *
1.114 markus 1872: reason2txt(int reason)
1873: {
1.143 deraadt 1874: switch (reason) {
1.114 markus 1875: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1876: return "administratively prohibited";
1877: case SSH2_OPEN_CONNECT_FAILED:
1878: return "connect failed";
1879: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1880: return "unknown channel type";
1881: case SSH2_OPEN_RESOURCE_SHORTAGE:
1882: return "resource shortage";
1883: }
1.117 stevesk 1884: return "unknown reason";
1.114 markus 1885: }
1886:
1.49 markus 1887: void
1.154 markus 1888: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1889: {
1.86 markus 1890: int id, reason;
1891: char *msg = NULL, *lang = NULL;
1.41 markus 1892: Channel *c;
1893:
1894: id = packet_get_int();
1895: c = channel_lookup(id);
1.25 markus 1896:
1.41 markus 1897: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1898: packet_disconnect("Received open failure for "
1899: "non-opening channel %d.", id);
1.44 markus 1900: if (compat20) {
1.86 markus 1901: reason = packet_get_int();
1.110 markus 1902: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1903: msg = packet_get_string(NULL);
1904: lang = packet_get_string(NULL);
1905: }
1.114 markus 1906: log("channel %d: open failed: %s%s%s", id,
1907: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1908: if (msg != NULL)
1909: xfree(msg);
1910: if (lang != NULL)
1911: xfree(lang);
1.44 markus 1912: }
1.152 markus 1913: packet_check_eom();
1.25 markus 1914: /* Free the channel. This will also close the socket. */
1.113 markus 1915: channel_free(c);
1.44 markus 1916: }
1917:
1.121 markus 1918: void
1.154 markus 1919: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1920: {
1921: Channel *c;
1922: int id, adjust;
1923:
1924: if (!compat20)
1925: return;
1926:
1927: /* Get the channel number and verify it. */
1928: id = packet_get_int();
1929: c = channel_lookup(id);
1.1 deraadt 1930:
1.121 markus 1931: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1932: log("Received window adjust for "
1933: "non-open channel %d.", id);
1934: return;
1935: }
1936: adjust = packet_get_int();
1.152 markus 1937: packet_check_eom();
1.121 markus 1938: debug2("channel %d: rcvd adjust %d", id, adjust);
1939: c->remote_window += adjust;
1940: }
1.1 deraadt 1941:
1.121 markus 1942: void
1.154 markus 1943: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1944: {
1.121 markus 1945: Channel *c = NULL;
1946: u_short host_port;
1947: char *host, *originator_string;
1948: int remote_id, sock = -1;
1949:
1950: remote_id = packet_get_int();
1951: host = packet_get_string(NULL);
1952: host_port = packet_get_int();
1.25 markus 1953:
1.121 markus 1954: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1955: originator_string = packet_get_string(NULL);
1956: } else {
1957: originator_string = xstrdup("unknown (remote did not supply name)");
1958: }
1.152 markus 1959: packet_check_eom();
1.121 markus 1960: sock = channel_connect_to(host, host_port);
1961: if (sock != -1) {
1962: c = channel_new("connected socket",
1963: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1964: originator_string, 1);
1.167 markus 1965: c->remote_id = remote_id;
1.25 markus 1966: }
1.121 markus 1967: if (c == NULL) {
1968: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1969: packet_put_int(remote_id);
1970: packet_send();
1971: }
1972: xfree(host);
1.1 deraadt 1973: }
1974:
1.121 markus 1975:
1976: /* -- tcp forwarding */
1.135 markus 1977:
1978: void
1979: channel_set_af(int af)
1980: {
1981: IPv4or6 = af;
1982: }
1.121 markus 1983:
1.160 markus 1984: static int
1985: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
1986: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 1987: {
1.113 markus 1988: Channel *c;
1.160 markus 1989: int success, sock, on = 1;
1.35 markus 1990: struct addrinfo hints, *ai, *aitop;
1.160 markus 1991: const char *host;
1.35 markus 1992: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 1993: struct linger linger;
1.25 markus 1994:
1.87 markus 1995: success = 0;
1.160 markus 1996: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
1997: listen_addr : host_to_connect;
1.87 markus 1998:
1.160 markus 1999: if (host == NULL) {
2000: error("No forward host name.");
2001: return success;
1.73 markus 2002: }
1.113 markus 2003: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2004: error("Forward host name too long.");
2005: return success;
2006: }
1.25 markus 2007:
1.28 markus 2008: /*
1.35 markus 2009: * getaddrinfo returns a loopback address if the hostname is
2010: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2011: */
1.35 markus 2012: memset(&hints, 0, sizeof(hints));
2013: hints.ai_family = IPv4or6;
2014: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2015: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2016: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2017: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2018: packet_disconnect("getaddrinfo: fatal error");
2019:
2020: for (ai = aitop; ai; ai = ai->ai_next) {
2021: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2022: continue;
2023: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2024: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2025: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2026: continue;
2027: }
2028: /* Create a port to listen for the host. */
2029: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2030: if (sock < 0) {
2031: /* this is no error since kernel may not support ipv6 */
2032: verbose("socket: %.100s", strerror(errno));
2033: continue;
2034: }
2035: /*
2036: * Set socket options. We would like the socket to disappear
2037: * as soon as it has been closed for whatever reason.
2038: */
2039: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2040: linger.l_onoff = 1;
2041: linger.l_linger = 5;
2042: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2043: debug("Local forwarding listening on %s port %s.", ntop, strport);
2044:
2045: /* Bind the socket to the address. */
2046: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2047: /* address can be in use ipv6 address is already bound */
2048: verbose("bind: %.100s", strerror(errno));
2049: close(sock);
2050: continue;
2051: }
2052: /* Start listening for connections on the socket. */
2053: if (listen(sock, 5) < 0) {
2054: error("listen: %.100s", strerror(errno));
2055: close(sock);
2056: continue;
2057: }
2058: /* Allocate a channel number for the socket. */
1.121 markus 2059: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2060: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2061: 0, xstrdup("port listener"), 1);
1.113 markus 2062: strlcpy(c->path, host, sizeof(c->path));
2063: c->host_port = port_to_connect;
2064: c->listening_port = listen_port;
1.35 markus 2065: success = 1;
2066: }
2067: if (success == 0)
1.160 markus 2068: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2069: listen_port);
1.35 markus 2070: freeaddrinfo(aitop);
1.87 markus 2071: return success;
1.25 markus 2072: }
1.1 deraadt 2073:
1.160 markus 2074: /* protocol local port fwd, used by ssh (and sshd in v1) */
2075: int
2076: channel_setup_local_fwd_listener(u_short listen_port,
2077: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2078: {
2079: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2080: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2081: }
2082:
2083: /* protocol v2 remote port fwd, used by sshd */
2084: int
2085: channel_setup_remote_fwd_listener(const char *listen_address,
2086: u_short listen_port, int gateway_ports)
2087: {
2088: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2089: listen_address, listen_port, NULL, 0, gateway_ports);
2090: }
2091:
1.27 markus 2092: /*
2093: * Initiate forwarding of connections to port "port" on remote host through
2094: * the secure channel to host:port from local side.
2095: */
1.1 deraadt 2096:
1.49 markus 2097: void
1.73 markus 2098: channel_request_remote_forwarding(u_short listen_port,
2099: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2100: {
1.153 markus 2101: int type, success = 0;
1.73 markus 2102:
1.25 markus 2103: /* Record locally that connection to this host/port is permitted. */
2104: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2105: fatal("channel_request_remote_forwarding: too many forwards");
2106:
2107: /* Send the forward request to the remote side. */
1.44 markus 2108: if (compat20) {
2109: const char *address_to_bind = "0.0.0.0";
2110: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2111: packet_put_cstring("tcpip-forward");
2112: packet_put_char(0); /* boolean: want reply */
2113: packet_put_cstring(address_to_bind);
2114: packet_put_int(listen_port);
1.73 markus 2115: packet_send();
2116: packet_write_wait();
2117: /* Assume that server accepts the request */
2118: success = 1;
1.44 markus 2119: } else {
2120: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2121: packet_put_int(listen_port);
2122: packet_put_cstring(host_to_connect);
1.44 markus 2123: packet_put_int(port_to_connect);
2124: packet_send();
2125: packet_write_wait();
1.73 markus 2126:
2127: /* Wait for response from the remote side. */
1.153 markus 2128: type = packet_read();
1.73 markus 2129: switch (type) {
2130: case SSH_SMSG_SUCCESS:
2131: success = 1;
2132: break;
2133: case SSH_SMSG_FAILURE:
2134: log("Warning: Server denied remote port forwarding.");
2135: break;
2136: default:
2137: /* Unknown packet */
2138: packet_disconnect("Protocol error for port forward request:"
2139: "received packet type %d.", type);
2140: }
2141: }
2142: if (success) {
2143: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2144: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2145: permitted_opens[num_permitted_opens].listen_port = listen_port;
2146: num_permitted_opens++;
1.44 markus 2147: }
1.1 deraadt 2148: }
2149:
1.27 markus 2150: /*
2151: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2152: * listening for the port, and sends back a success reply (or disconnect
2153: * message if there was an error). This never returns if there was an error.
2154: */
1.1 deraadt 2155:
1.49 markus 2156: void
1.56 markus 2157: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2158: {
1.31 markus 2159: u_short port, host_port;
1.25 markus 2160: char *hostname;
1.1 deraadt 2161:
1.25 markus 2162: /* Get arguments from the packet. */
2163: port = packet_get_int();
2164: hostname = packet_get_string(NULL);
2165: host_port = packet_get_int();
2166:
1.27 markus 2167: /*
2168: * Check that an unprivileged user is not trying to forward a
2169: * privileged port.
2170: */
1.25 markus 2171: if (port < IPPORT_RESERVED && !is_root)
2172: packet_disconnect("Requested forwarding of port %d but user is not root.",
2173: port);
1.73 markus 2174: /* Initiate forwarding */
1.160 markus 2175: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2176:
2177: /* Free the argument string. */
2178: xfree(hostname);
1.1 deraadt 2179: }
2180:
1.99 markus 2181: /*
2182: * Permits opening to any host/port if permitted_opens[] is empty. This is
2183: * usually called by the server, because the user could connect to any port
2184: * anyway, and the server has no way to know but to trust the client anyway.
2185: */
2186: void
1.142 itojun 2187: channel_permit_all_opens(void)
1.99 markus 2188: {
2189: if (num_permitted_opens == 0)
2190: all_opens_permitted = 1;
2191: }
2192:
1.101 markus 2193: void
1.99 markus 2194: channel_add_permitted_opens(char *host, int port)
2195: {
2196: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2197: fatal("channel_request_remote_forwarding: too many forwards");
2198: debug("allow port forwarding to host %s port %d", host, port);
2199:
2200: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2201: permitted_opens[num_permitted_opens].port_to_connect = port;
2202: num_permitted_opens++;
2203:
2204: all_opens_permitted = 0;
2205: }
2206:
1.101 markus 2207: void
1.99 markus 2208: channel_clear_permitted_opens(void)
2209: {
2210: int i;
2211:
2212: for (i = 0; i < num_permitted_opens; i++)
2213: xfree(permitted_opens[i].host_to_connect);
2214: num_permitted_opens = 0;
2215:
2216: }
2217:
2218:
2219: /* return socket to remote host, port */
1.127 itojun 2220: static int
1.99 markus 2221: connect_to(const char *host, u_short port)
1.41 markus 2222: {
2223: struct addrinfo hints, *ai, *aitop;
2224: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2225: int gaierr;
2226: int sock = -1;
2227:
2228: memset(&hints, 0, sizeof(hints));
2229: hints.ai_family = IPv4or6;
2230: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2231: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2232: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2233: error("connect_to %.100s: unknown host (%s)", host,
2234: gai_strerror(gaierr));
1.41 markus 2235: return -1;
2236: }
2237: for (ai = aitop; ai; ai = ai->ai_next) {
2238: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2239: continue;
2240: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2241: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2242: error("connect_to: getnameinfo failed");
1.41 markus 2243: continue;
2244: }
2245: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2246: if (sock < 0) {
2247: error("socket: %.100s", strerror(errno));
2248: continue;
2249: }
1.80 markus 2250: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2251: fatal("connect_to: F_SETFL: %s", strerror(errno));
2252: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2253: errno != EINPROGRESS) {
1.99 markus 2254: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2255: strerror(errno));
2256: close(sock);
1.89 stevesk 2257: continue; /* fail -- try next */
1.41 markus 2258: }
2259: break; /* success */
2260:
2261: }
2262: freeaddrinfo(aitop);
2263: if (!ai) {
1.99 markus 2264: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2265: return -1;
2266: }
2267: /* success */
1.169 ! stevesk 2268: set_nodelay(sock);
1.41 markus 2269: return sock;
2270: }
1.99 markus 2271:
1.73 markus 2272: int
1.130 stevesk 2273: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2274: {
2275: int i;
1.99 markus 2276:
1.73 markus 2277: for (i = 0; i < num_permitted_opens; i++)
2278: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2279: return connect_to(
1.73 markus 2280: permitted_opens[i].host_to_connect,
2281: permitted_opens[i].port_to_connect);
1.74 markus 2282: error("WARNING: Server requests forwarding for unknown listen_port %d",
2283: listen_port);
1.73 markus 2284: return -1;
2285: }
2286:
1.99 markus 2287: /* Check if connecting to that port is permitted and connect. */
2288: int
2289: channel_connect_to(const char *host, u_short port)
2290: {
2291: int i, permit;
2292:
2293: permit = all_opens_permitted;
2294: if (!permit) {
2295: for (i = 0; i < num_permitted_opens; i++)
2296: if (permitted_opens[i].port_to_connect == port &&
2297: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2298: permit = 1;
2299:
2300: }
2301: if (!permit) {
2302: log("Received request to connect to host %.100s port %d, "
2303: "but the request was denied.", host, port);
2304: return -1;
2305: }
2306: return connect_to(host, port);
2307: }
2308:
1.121 markus 2309: /* -- X11 forwarding */
1.1 deraadt 2310:
1.27 markus 2311: /*
2312: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2313: * Returns a suitable display number for the DISPLAY variable, or -1 if
2314: * an error occurs.
1.27 markus 2315: */
1.141 stevesk 2316: int
1.163 stevesk 2317: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.149 markus 2318: int single_connection)
1.1 deraadt 2319: {
1.149 markus 2320: Channel *nc = NULL;
1.31 markus 2321: int display_number, sock;
2322: u_short port;
1.35 markus 2323: struct addrinfo hints, *ai, *aitop;
2324: char strport[NI_MAXSERV];
2325: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2326:
1.33 markus 2327: for (display_number = x11_display_offset;
1.148 deraadt 2328: display_number < MAX_DISPLAYS;
2329: display_number++) {
1.25 markus 2330: port = 6000 + display_number;
1.35 markus 2331: memset(&hints, 0, sizeof(hints));
2332: hints.ai_family = IPv4or6;
1.163 stevesk 2333: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2334: hints.ai_socktype = SOCK_STREAM;
2335: snprintf(strport, sizeof strport, "%d", port);
2336: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2337: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2338: return -1;
1.25 markus 2339: }
1.35 markus 2340: for (ai = aitop; ai; ai = ai->ai_next) {
2341: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2342: continue;
2343: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2344: if (sock < 0) {
2345: error("socket: %.100s", strerror(errno));
1.141 stevesk 2346: return -1;
1.35 markus 2347: }
2348: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2349: debug("bind port %d: %.100s", port, strerror(errno));
2350: close(sock);
2351: for (n = 0; n < num_socks; n++) {
2352: close(socks[n]);
2353: }
2354: num_socks = 0;
2355: break;
2356: }
2357: socks[num_socks++] = sock;
2358: if (num_socks == NUM_SOCKS)
2359: break;
1.25 markus 2360: }
1.83 stevesk 2361: freeaddrinfo(aitop);
1.35 markus 2362: if (num_socks > 0)
2363: break;
1.25 markus 2364: }
2365: if (display_number >= MAX_DISPLAYS) {
2366: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2367: return -1;
1.25 markus 2368: }
2369: /* Start listening for connections on the socket. */
1.35 markus 2370: for (n = 0; n < num_socks; n++) {
2371: sock = socks[n];
2372: if (listen(sock, 5) < 0) {
2373: error("listen: %.100s", strerror(errno));
2374: close(sock);
1.141 stevesk 2375: return -1;
1.35 markus 2376: }
1.25 markus 2377: }
1.35 markus 2378:
2379: /* Allocate a channel for each socket. */
2380: for (n = 0; n < num_socks; n++) {
2381: sock = socks[n];
1.149 markus 2382: nc = channel_new("x11 listener",
1.51 markus 2383: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2384: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2385: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2386: nc->single_connection = single_connection;
1.35 markus 2387: }
1.1 deraadt 2388:
1.141 stevesk 2389: /* Return the display number for the DISPLAY environment variable. */
2390: return display_number;
1.1 deraadt 2391: }
2392:
1.127 itojun 2393: static int
1.77 markus 2394: connect_local_xsocket(u_int dnr)
1.1 deraadt 2395: {
1.25 markus 2396: int sock;
2397: struct sockaddr_un addr;
2398:
1.147 stevesk 2399: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2400: if (sock < 0)
2401: error("socket: %.100s", strerror(errno));
2402: memset(&addr, 0, sizeof(addr));
2403: addr.sun_family = AF_UNIX;
2404: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2405: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2406: return sock;
2407: close(sock);
1.25 markus 2408: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2409: return -1;
1.1 deraadt 2410: }
2411:
1.51 markus 2412: int
2413: x11_connect_display(void)
1.1 deraadt 2414: {
1.162 stevesk 2415: int display_number, sock = 0;
1.25 markus 2416: const char *display;
1.51 markus 2417: char buf[1024], *cp;
1.35 markus 2418: struct addrinfo hints, *ai, *aitop;
2419: char strport[NI_MAXSERV];
2420: int gaierr;
1.25 markus 2421:
2422: /* Try to open a socket for the local X server. */
2423: display = getenv("DISPLAY");
2424: if (!display) {
2425: error("DISPLAY not set.");
1.51 markus 2426: return -1;
1.25 markus 2427: }
1.27 markus 2428: /*
2429: * Now we decode the value of the DISPLAY variable and make a
2430: * connection to the real X server.
2431: */
2432:
2433: /*
2434: * Check if it is a unix domain socket. Unix domain displays are in
2435: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2436: */
1.25 markus 2437: if (strncmp(display, "unix:", 5) == 0 ||
2438: display[0] == ':') {
2439: /* Connect to the unix domain socket. */
2440: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2441: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2442: display);
1.51 markus 2443: return -1;
1.25 markus 2444: }
2445: /* Create a socket. */
2446: sock = connect_local_xsocket(display_number);
2447: if (sock < 0)
1.51 markus 2448: return -1;
1.25 markus 2449:
2450: /* OK, we now have a connection to the display. */
1.51 markus 2451: return sock;
1.25 markus 2452: }
1.27 markus 2453: /*
2454: * Connect to an inet socket. The DISPLAY value is supposedly
2455: * hostname:d[.s], where hostname may also be numeric IP address.
2456: */
1.145 stevesk 2457: strlcpy(buf, display, sizeof(buf));
1.25 markus 2458: cp = strchr(buf, ':');
2459: if (!cp) {
2460: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2461: return -1;
1.25 markus 2462: }
2463: *cp = 0;
1.27 markus 2464: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2465: if (sscanf(cp + 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: }
1.35 markus 2470:
2471: /* Look up the host address */
2472: memset(&hints, 0, sizeof(hints));
2473: hints.ai_family = IPv4or6;
2474: hints.ai_socktype = SOCK_STREAM;
2475: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2476: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2477: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2478: return -1;
1.25 markus 2479: }
1.35 markus 2480: for (ai = aitop; ai; ai = ai->ai_next) {
2481: /* Create a socket. */
2482: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2483: if (sock < 0) {
2484: debug("socket: %.100s", strerror(errno));
1.41 markus 2485: continue;
2486: }
2487: /* Connect it to the display. */
2488: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2489: debug("connect %.100s port %d: %.100s", buf,
2490: 6000 + display_number, strerror(errno));
2491: close(sock);
2492: continue;
2493: }
2494: /* Success */
2495: break;
1.35 markus 2496: }
2497: freeaddrinfo(aitop);
2498: if (!ai) {
1.49 markus 2499: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2500: strerror(errno));
1.51 markus 2501: return -1;
1.25 markus 2502: }
1.162 stevesk 2503: set_nodelay(sock);
1.51 markus 2504: return sock;
2505: }
2506:
2507: /*
2508: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2509: * the remote channel number. We should do whatever we want, and respond
2510: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2511: */
2512:
2513: void
1.154 markus 2514: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2515: {
1.113 markus 2516: Channel *c = NULL;
2517: int remote_id, sock = 0;
1.51 markus 2518: char *remote_host;
1.25 markus 2519:
1.113 markus 2520: debug("Received X11 open request.");
1.51 markus 2521:
1.113 markus 2522: remote_id = packet_get_int();
1.121 markus 2523:
2524: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2525: remote_host = packet_get_string(NULL);
1.51 markus 2526: } else {
2527: remote_host = xstrdup("unknown (remote did not supply name)");
2528: }
1.152 markus 2529: packet_check_eom();
1.25 markus 2530:
1.51 markus 2531: /* Obtain a connection to the real X display. */
2532: sock = x11_connect_display();
1.113 markus 2533: if (sock != -1) {
2534: /* Allocate a channel for this connection. */
2535: c = channel_new("connected x11 socket",
2536: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2537: remote_host, 1);
1.167 markus 2538: c->remote_id = remote_id;
2539: c->force_drain = 1;
1.113 markus 2540: }
2541: if (c == NULL) {
1.51 markus 2542: /* Send refusal to the remote host. */
2543: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2544: packet_put_int(remote_id);
1.51 markus 2545: } else {
2546: /* Send a confirmation to the remote host. */
2547: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2548: packet_put_int(remote_id);
2549: packet_put_int(c->self);
1.51 markus 2550: }
1.113 markus 2551: packet_send();
1.72 markus 2552: }
2553:
2554: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2555: void
1.154 markus 2556: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2557: {
2558: int rchan = packet_get_int();
1.143 deraadt 2559: switch (type) {
1.72 markus 2560: case SSH_SMSG_AGENT_OPEN:
2561: error("Warning: ssh server tried agent forwarding.");
2562: break;
2563: case SSH_SMSG_X11_OPEN:
2564: error("Warning: ssh server tried X11 forwarding.");
2565: break;
2566: default:
1.154 markus 2567: error("deny_input_open: type %d", type);
1.72 markus 2568: break;
2569: }
2570: error("Warning: this is probably a break in attempt by a malicious server.");
2571: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2572: packet_put_int(rchan);
2573: packet_send();
1.1 deraadt 2574: }
2575:
1.27 markus 2576: /*
2577: * Requests forwarding of X11 connections, generates fake authentication
2578: * data, and enables authentication spoofing.
1.121 markus 2579: * This should be called in the client only.
1.27 markus 2580: */
1.49 markus 2581: void
1.51 markus 2582: x11_request_forwarding_with_spoofing(int client_session_id,
2583: const char *proto, const char *data)
1.1 deraadt 2584: {
1.77 markus 2585: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2586: u_int i, value, len;
1.25 markus 2587: char *new_data;
2588: int screen_number;
2589: const char *cp;
2590: u_int32_t rand = 0;
2591:
2592: cp = getenv("DISPLAY");
2593: if (cp)
2594: cp = strchr(cp, ':');
2595: if (cp)
2596: cp = strchr(cp, '.');
2597: if (cp)
2598: screen_number = atoi(cp + 1);
2599: else
2600: screen_number = 0;
2601:
2602: /* Save protocol name. */
2603: x11_saved_proto = xstrdup(proto);
2604:
1.27 markus 2605: /*
2606: * Extract real authentication data and generate fake data of the
2607: * same length.
2608: */
1.25 markus 2609: x11_saved_data = xmalloc(data_len);
2610: x11_fake_data = xmalloc(data_len);
2611: for (i = 0; i < data_len; i++) {
2612: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2613: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2614: if (i % 4 == 0)
2615: rand = arc4random();
2616: x11_saved_data[i] = value;
2617: x11_fake_data[i] = rand & 0xff;
2618: rand >>= 8;
2619: }
2620: x11_saved_data_len = data_len;
2621: x11_fake_data_len = data_len;
2622:
2623: /* Convert the fake data into hex. */
1.90 markus 2624: len = 2 * data_len + 1;
2625: new_data = xmalloc(len);
1.25 markus 2626: for (i = 0; i < data_len; i++)
1.90 markus 2627: snprintf(new_data + 2 * i, len - 2 * i,
2628: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2629:
2630: /* Send the request packet. */
1.51 markus 2631: if (compat20) {
2632: channel_request_start(client_session_id, "x11-req", 0);
2633: packet_put_char(0); /* XXX bool single connection */
2634: } else {
2635: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2636: }
2637: packet_put_cstring(proto);
2638: packet_put_cstring(new_data);
1.25 markus 2639: packet_put_int(screen_number);
2640: packet_send();
2641: packet_write_wait();
2642: xfree(new_data);
1.1 deraadt 2643: }
2644:
1.121 markus 2645:
2646: /* -- agent forwarding */
2647:
1.1 deraadt 2648: /* Sends a message to the server to request authentication fd forwarding. */
2649:
1.49 markus 2650: void
1.142 itojun 2651: auth_request_forwarding(void)
1.1 deraadt 2652: {
1.25 markus 2653: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2654: packet_send();
2655: packet_write_wait();
1.1 deraadt 2656: }
2657:
1.27 markus 2658: /*
2659: * Returns the name of the forwarded authentication socket. Returns NULL if
2660: * there is no forwarded authentication socket. The returned value points to
2661: * a static buffer.
2662: */
1.1 deraadt 2663:
1.25 markus 2664: char *
1.142 itojun 2665: auth_get_socket_name(void)
1.1 deraadt 2666: {
1.121 markus 2667: return auth_sock_name;
1.1 deraadt 2668: }
2669:
1.12 markus 2670: /* removes the agent forwarding socket */
2671:
1.49 markus 2672: void
1.123 markus 2673: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2674: {
1.123 markus 2675: struct passwd *pw = _pw;
2676:
1.122 markus 2677: if (auth_sock_name) {
1.123 markus 2678: temporarily_use_uid(pw);
1.122 markus 2679: unlink(auth_sock_name);
2680: rmdir(auth_sock_dir);
2681: auth_sock_name = NULL;
1.123 markus 2682: restore_uid();
1.122 markus 2683: }
1.12 markus 2684: }
2685:
1.27 markus 2686: /*
1.59 markus 2687: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2688: * This starts forwarding authentication requests.
2689: */
1.1 deraadt 2690:
1.59 markus 2691: int
1.25 markus 2692: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2693: {
1.113 markus 2694: Channel *nc;
2695: int sock;
1.25 markus 2696: struct sockaddr_un sunaddr;
2697:
1.121 markus 2698: if (auth_get_socket_name() != NULL) {
2699: error("authentication forwarding requested twice.");
2700: return 0;
2701: }
1.25 markus 2702:
2703: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2704: temporarily_use_uid(pw);
1.25 markus 2705:
2706: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2707: auth_sock_name = xmalloc(MAXPATHLEN);
2708: auth_sock_dir = xmalloc(MAXPATHLEN);
2709: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2710:
2711: /* Create private directory for socket */
1.121 markus 2712: if (mkdtemp(auth_sock_dir) == NULL) {
2713: packet_send_debug("Agent forwarding disabled: "
2714: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2715: restore_uid();
1.121 markus 2716: xfree(auth_sock_name);
2717: xfree(auth_sock_dir);
2718: auth_sock_name = NULL;
2719: auth_sock_dir = NULL;
1.59 markus 2720: return 0;
2721: }
1.121 markus 2722: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2723: auth_sock_dir, (int) getpid());
1.25 markus 2724:
1.122 markus 2725: /* delete agent socket on fatal() */
1.123 markus 2726: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2727:
1.25 markus 2728: /* Create the socket. */
2729: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2730: if (sock < 0)
2731: packet_disconnect("socket: %.100s", strerror(errno));
2732:
2733: /* Bind it to the name. */
2734: memset(&sunaddr, 0, sizeof(sunaddr));
2735: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2736: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2737:
2738: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2739: packet_disconnect("bind: %.100s", strerror(errno));
2740:
2741: /* Restore the privileged uid. */
2742: restore_uid();
2743:
2744: /* Start listening on the socket. */
2745: if (listen(sock, 5) < 0)
2746: packet_disconnect("listen: %.100s", strerror(errno));
2747:
2748: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2749: nc = channel_new("auth socket",
1.73 markus 2750: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2751: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2752: 0, xstrdup("auth socket"), 1);
1.121 markus 2753: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2754: return 1;
1.1 deraadt 2755: }
2756:
2757: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2758:
1.49 markus 2759: void
1.154 markus 2760: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2761: {
1.113 markus 2762: Channel *c = NULL;
2763: int remote_id, sock;
1.121 markus 2764: char *name;
1.41 markus 2765:
1.25 markus 2766: /* Read the remote channel number from the message. */
1.113 markus 2767: remote_id = packet_get_int();
1.152 markus 2768: packet_check_eom();
1.25 markus 2769:
1.27 markus 2770: /*
2771: * Get a connection to the local authentication agent (this may again
2772: * get forwarded).
2773: */
1.25 markus 2774: sock = ssh_get_authentication_socket();
2775:
1.27 markus 2776: /*
2777: * If we could not connect the agent, send an error message back to
2778: * the server. This should never happen unless the agent dies,
2779: * because authentication forwarding is only enabled if we have an
2780: * agent.
2781: */
1.113 markus 2782: if (sock >= 0) {
1.121 markus 2783: name = xstrdup("authentication agent connection");
2784: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2785: -1, 0, 0, 0, name, 1);
1.167 markus 2786: c->remote_id = remote_id;
2787: c->force_drain = 1;
1.113 markus 2788: }
2789: if (c == NULL) {
1.25 markus 2790: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2791: packet_put_int(remote_id);
2792: } else {
2793: /* Send a confirmation to the remote host. */
2794: debug("Forwarding authentication connection.");
2795: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2796: packet_put_int(remote_id);
2797: packet_put_int(c->self);
1.25 markus 2798: }
2799: packet_send();
1.1 deraadt 2800: }