Annotation of src/usr.bin/ssh/channels.c, Revision 1.172.2.3
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"
1.172.2.3! jason 42: RCSID("$OpenBSD: channels.c,v 1.179 2002/06/26 08:55:02 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.h"
1.44 markus 57:
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.1 deraadt 71: static int channels_alloc = 0;
72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
112: /* Saved X11 authentication protocol name. */
113: static char *x11_saved_proto = NULL;
114:
115: /* Saved X11 authentication data. This is the real data. */
116: static char *x11_saved_data = NULL;
117: static u_int x11_saved_data_len = 0;
118:
119: /*
120: * Fake X11 authentication data. This is what the server will be sending us;
121: * we should replace any occurrences of this by the real data.
122: */
123: static char *x11_fake_data = NULL;
124: static u_int x11_fake_data_len;
125:
126:
127: /* -- agent forwarding */
128:
129: #define NUM_SOCKS 10
130:
1.82 markus 131: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 132: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 133:
1.121 markus 134: /* helper */
1.127 itojun 135: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 136:
1.121 markus 137: /* -- channel core */
1.41 markus 138:
139: Channel *
140: channel_lookup(int id)
141: {
142: Channel *c;
1.113 markus 143:
1.171 markus 144: if (id < 0 || id >= channels_alloc) {
1.41 markus 145: log("channel_lookup: %d: bad id", id);
146: return NULL;
147: }
1.113 markus 148: c = channels[id];
149: if (c == NULL) {
1.41 markus 150: log("channel_lookup: %d: bad id: channel free", id);
151: return NULL;
152: }
153: return c;
1.55 markus 154: }
155:
1.27 markus 156: /*
1.55 markus 157: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 158: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 159: */
1.1 deraadt 160:
1.127 itojun 161: static void
1.71 markus 162: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
163: int extusage, int nonblock)
1.1 deraadt 164: {
1.25 markus 165: /* Update the maximum file descriptor value. */
1.84 markus 166: channel_max_fd = MAX(channel_max_fd, rfd);
167: channel_max_fd = MAX(channel_max_fd, wfd);
168: channel_max_fd = MAX(channel_max_fd, efd);
169:
1.27 markus 170: /* XXX set close-on-exec -markus */
1.55 markus 171:
1.52 markus 172: c->rfd = rfd;
173: c->wfd = wfd;
174: c->sock = (rfd == wfd) ? rfd : -1;
175: c->efd = efd;
176: c->extended_usage = extusage;
1.71 markus 177:
1.91 markus 178: /* XXX ugly hack: nonblock is only set by the server */
179: if (nonblock && isatty(c->rfd)) {
1.94 markus 180: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 181: c->isatty = 1;
182: if (!isatty(c->wfd)) {
1.94 markus 183: error("channel %d: wfd %d is not a tty?",
1.91 markus 184: c->self, c->wfd);
185: }
186: } else {
187: c->isatty = 0;
188: }
189:
1.71 markus 190: /* enable nonblocking mode */
191: if (nonblock) {
192: if (rfd != -1)
193: set_nonblock(rfd);
194: if (wfd != -1)
195: set_nonblock(wfd);
196: if (efd != -1)
197: set_nonblock(efd);
198: }
1.52 markus 199: }
200:
201: /*
202: * Allocate a new channel object and set its type and socket. This will cause
203: * remote_name to be freed.
204: */
205:
1.113 markus 206: Channel *
1.52 markus 207: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.172.2.3! jason 208: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 209: {
210: int i, found;
211: Channel *c;
1.25 markus 212:
213: /* Do initial allocation if this is the first call. */
214: if (channels_alloc == 0) {
215: channels_alloc = 10;
1.113 markus 216: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 217: for (i = 0; i < channels_alloc; i++)
1.113 markus 218: channels[i] = NULL;
1.126 markus 219: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 220: }
221: /* Try to find a free slot where to put the new channel. */
222: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 223: if (channels[i] == NULL) {
1.25 markus 224: /* Found a free slot. */
225: found = i;
226: break;
227: }
228: if (found == -1) {
1.27 markus 229: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 230: found = channels_alloc;
231: channels_alloc += 10;
1.172.2.3! jason 232: if (channels_alloc > 10000)
! 233: fatal("channel_new: internal error: channels_alloc %d "
! 234: "too big.", channels_alloc);
1.70 markus 235: debug2("channel: expanding %d", channels_alloc);
1.113 markus 236: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 237: for (i = found; i < channels_alloc; i++)
1.113 markus 238: channels[i] = NULL;
1.25 markus 239: }
1.113 markus 240: /* Initialize and return new channel. */
241: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 242: memset(c, 0, sizeof(Channel));
1.25 markus 243: buffer_init(&c->input);
244: buffer_init(&c->output);
1.41 markus 245: buffer_init(&c->extended);
1.159 markus 246: c->ostate = CHAN_OUTPUT_OPEN;
247: c->istate = CHAN_INPUT_OPEN;
248: c->flags = 0;
1.71 markus 249: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 250: c->self = found;
251: c->type = type;
1.41 markus 252: c->ctype = ctype;
1.51 markus 253: c->local_window = window;
254: c->local_window_max = window;
255: c->local_consumed = 0;
256: c->local_maxpacket = maxpack;
1.25 markus 257: c->remote_id = -1;
258: c->remote_name = remote_name;
1.41 markus 259: c->remote_window = 0;
260: c->remote_maxpacket = 0;
1.133 markus 261: c->force_drain = 0;
1.149 markus 262: c->single_connection = 0;
1.131 markus 263: c->detach_user = NULL;
1.165 markus 264: c->confirm = NULL;
1.65 markus 265: c->input_filter = NULL;
1.25 markus 266: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 267: return c;
1.1 deraadt 268: }
1.52 markus 269:
1.132 markus 270: static int
271: channel_find_maxfd(void)
272: {
273: int i, max = 0;
274: Channel *c;
275:
276: for (i = 0; i < channels_alloc; i++) {
277: c = channels[i];
278: if (c != NULL) {
279: max = MAX(max, c->rfd);
280: max = MAX(max, c->wfd);
281: max = MAX(max, c->efd);
282: }
283: }
284: return max;
285: }
286:
287: int
288: channel_close_fd(int *fdp)
289: {
290: int ret = 0, fd = *fdp;
291:
292: if (fd != -1) {
293: ret = close(fd);
294: *fdp = -1;
295: if (fd == channel_max_fd)
296: channel_max_fd = channel_find_maxfd();
297: }
298: return ret;
299: }
300:
1.52 markus 301: /* Close all channel fd/socket. */
302:
1.127 itojun 303: static void
1.52 markus 304: channel_close_fds(Channel *c)
305: {
1.118 markus 306: debug3("channel_close_fds: channel %d: r %d w %d e %d",
307: c->self, c->rfd, c->wfd, c->efd);
308:
1.132 markus 309: channel_close_fd(&c->sock);
310: channel_close_fd(&c->rfd);
311: channel_close_fd(&c->wfd);
312: channel_close_fd(&c->efd);
1.121 markus 313: }
314:
315: /* Free the channel and close its fd/socket. */
316:
317: void
318: channel_free(Channel *c)
319: {
320: char *s;
321: int i, n;
322:
323: for (n = 0, i = 0; i < channels_alloc; i++)
324: if (channels[i])
325: n++;
326: debug("channel_free: channel %d: %s, nchannels %d", c->self,
327: c->remote_name ? c->remote_name : "???", n);
328:
329: s = channel_open_message();
330: debug3("channel_free: status: %s", s);
331: xfree(s);
332:
333: if (c->sock != -1)
334: shutdown(c->sock, SHUT_RDWR);
335: channel_close_fds(c);
336: buffer_free(&c->input);
337: buffer_free(&c->output);
338: buffer_free(&c->extended);
339: if (c->remote_name) {
340: xfree(c->remote_name);
341: c->remote_name = NULL;
342: }
343: channels[c->self] = NULL;
344: xfree(c);
345: }
346:
347: void
1.126 markus 348: channel_free_all(void)
1.121 markus 349: {
350: int i;
351:
1.126 markus 352: for (i = 0; i < channels_alloc; i++)
353: if (channels[i] != NULL)
354: channel_free(channels[i]);
1.131 markus 355: }
356:
1.121 markus 357: /*
358: * Closes the sockets/fds of all channels. This is used to close extra file
359: * descriptors after a fork.
360: */
361:
362: void
1.142 itojun 363: channel_close_all(void)
1.121 markus 364: {
365: int i;
366:
367: for (i = 0; i < channels_alloc; i++)
368: if (channels[i] != NULL)
369: channel_close_fds(channels[i]);
370: }
371:
372: /*
1.131 markus 373: * Stop listening to channels.
374: */
375:
376: void
377: channel_stop_listening(void)
378: {
379: int i;
380: Channel *c;
381:
382: for (i = 0; i < channels_alloc; i++) {
383: c = channels[i];
384: if (c != NULL) {
385: switch (c->type) {
386: case SSH_CHANNEL_AUTH_SOCKET:
387: case SSH_CHANNEL_PORT_LISTENER:
388: case SSH_CHANNEL_RPORT_LISTENER:
389: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 390: channel_close_fd(&c->sock);
1.131 markus 391: channel_free(c);
392: break;
393: }
394: }
395: }
396: }
397:
398: /*
1.121 markus 399: * Returns true if no channel has too much buffered data, and false if one or
400: * more channel is overfull.
401: */
402:
403: int
1.142 itojun 404: channel_not_very_much_buffered_data(void)
1.121 markus 405: {
406: u_int i;
407: Channel *c;
408:
409: for (i = 0; i < channels_alloc; i++) {
410: c = channels[i];
411: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 412: #if 0
413: if (!compat20 &&
414: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 415: debug("channel %d: big input buffer %d",
416: c->self, buffer_len(&c->input));
417: return 0;
418: }
1.136 markus 419: #endif
1.121 markus 420: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 421: debug("channel %d: big output buffer %d > %d",
422: c->self, buffer_len(&c->output),
423: packet_get_maxsize());
1.121 markus 424: return 0;
425: }
426: }
427: }
428: return 1;
429: }
430:
431: /* Returns true if any channel is still open. */
432:
433: int
1.142 itojun 434: channel_still_open(void)
1.121 markus 435: {
436: int i;
437: Channel *c;
438:
439: for (i = 0; i < channels_alloc; i++) {
440: c = channels[i];
441: if (c == NULL)
442: continue;
443: switch (c->type) {
444: case SSH_CHANNEL_X11_LISTENER:
445: case SSH_CHANNEL_PORT_LISTENER:
446: case SSH_CHANNEL_RPORT_LISTENER:
447: case SSH_CHANNEL_CLOSED:
448: case SSH_CHANNEL_AUTH_SOCKET:
449: case SSH_CHANNEL_DYNAMIC:
450: case SSH_CHANNEL_CONNECTING:
451: case SSH_CHANNEL_ZOMBIE:
452: continue;
453: case SSH_CHANNEL_LARVAL:
454: if (!compat20)
455: fatal("cannot happen: SSH_CHANNEL_LARVAL");
456: continue;
457: case SSH_CHANNEL_OPENING:
458: case SSH_CHANNEL_OPEN:
459: case SSH_CHANNEL_X11_OPEN:
460: return 1;
461: case SSH_CHANNEL_INPUT_DRAINING:
462: case SSH_CHANNEL_OUTPUT_DRAINING:
463: if (!compat13)
464: fatal("cannot happen: OUT_DRAIN");
465: return 1;
466: default:
467: fatal("channel_still_open: bad channel type %d", c->type);
468: /* NOTREACHED */
469: }
470: }
471: return 0;
472: }
473:
474: /* Returns the id of an open channel suitable for keepaliving */
475:
476: int
1.142 itojun 477: channel_find_open(void)
1.121 markus 478: {
479: int i;
480: Channel *c;
481:
482: for (i = 0; i < channels_alloc; i++) {
483: c = channels[i];
484: if (c == NULL)
485: continue;
486: switch (c->type) {
487: case SSH_CHANNEL_CLOSED:
488: case SSH_CHANNEL_DYNAMIC:
489: case SSH_CHANNEL_X11_LISTENER:
490: case SSH_CHANNEL_PORT_LISTENER:
491: case SSH_CHANNEL_RPORT_LISTENER:
492: case SSH_CHANNEL_OPENING:
493: case SSH_CHANNEL_CONNECTING:
494: case SSH_CHANNEL_ZOMBIE:
495: continue;
496: case SSH_CHANNEL_LARVAL:
497: case SSH_CHANNEL_AUTH_SOCKET:
498: case SSH_CHANNEL_OPEN:
499: case SSH_CHANNEL_X11_OPEN:
500: return i;
501: case SSH_CHANNEL_INPUT_DRAINING:
502: case SSH_CHANNEL_OUTPUT_DRAINING:
503: if (!compat13)
504: fatal("cannot happen: OUT_DRAIN");
505: return i;
506: default:
507: fatal("channel_find_open: bad channel type %d", c->type);
508: /* NOTREACHED */
509: }
510: }
511: return -1;
512: }
513:
514:
515: /*
516: * Returns a message describing the currently open forwarded connections,
517: * suitable for sending to the client. The message contains crlf pairs for
518: * newlines.
519: */
520:
521: char *
1.142 itojun 522: channel_open_message(void)
1.121 markus 523: {
524: Buffer buffer;
525: Channel *c;
526: char buf[1024], *cp;
527: int i;
528:
529: buffer_init(&buffer);
530: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
531: buffer_append(&buffer, buf, strlen(buf));
532: for (i = 0; i < channels_alloc; i++) {
533: c = channels[i];
534: if (c == NULL)
535: continue;
536: switch (c->type) {
537: case SSH_CHANNEL_X11_LISTENER:
538: case SSH_CHANNEL_PORT_LISTENER:
539: case SSH_CHANNEL_RPORT_LISTENER:
540: case SSH_CHANNEL_CLOSED:
541: case SSH_CHANNEL_AUTH_SOCKET:
542: case SSH_CHANNEL_ZOMBIE:
543: continue;
544: case SSH_CHANNEL_LARVAL:
545: case SSH_CHANNEL_OPENING:
546: case SSH_CHANNEL_CONNECTING:
547: case SSH_CHANNEL_DYNAMIC:
548: case SSH_CHANNEL_OPEN:
549: case SSH_CHANNEL_X11_OPEN:
550: case SSH_CHANNEL_INPUT_DRAINING:
551: case SSH_CHANNEL_OUTPUT_DRAINING:
552: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
553: c->self, c->remote_name,
554: c->type, c->remote_id,
555: c->istate, buffer_len(&c->input),
556: c->ostate, buffer_len(&c->output),
557: c->rfd, c->wfd);
558: buffer_append(&buffer, buf, strlen(buf));
559: continue;
560: default:
561: fatal("channel_open_message: bad channel type %d", c->type);
562: /* NOTREACHED */
563: }
564: }
565: buffer_append(&buffer, "\0", 1);
566: cp = xstrdup(buffer_ptr(&buffer));
567: buffer_free(&buffer);
568: return cp;
569: }
570:
571: void
572: channel_send_open(int id)
573: {
574: Channel *c = channel_lookup(id);
575: if (c == NULL) {
576: log("channel_send_open: %d: bad id", id);
577: return;
578: }
579: debug("send channel open %d", id);
580: packet_start(SSH2_MSG_CHANNEL_OPEN);
581: packet_put_cstring(c->ctype);
582: packet_put_int(c->self);
583: packet_put_int(c->local_window);
584: packet_put_int(c->local_maxpacket);
585: packet_send();
586: }
587:
588: void
1.166 markus 589: channel_request_start(int local_id, char *service, int wantconfirm)
1.121 markus 590: {
1.166 markus 591: Channel *c = channel_lookup(local_id);
1.121 markus 592: if (c == NULL) {
1.166 markus 593: log("channel_request_start: %d: unknown channel id", local_id);
1.121 markus 594: return;
595: }
1.166 markus 596: debug("channel request %d: %s", local_id, service) ;
1.121 markus 597: packet_start(SSH2_MSG_CHANNEL_REQUEST);
598: packet_put_int(c->remote_id);
599: packet_put_cstring(service);
600: packet_put_char(wantconfirm);
601: }
602: void
1.165 markus 603: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 604: {
605: Channel *c = channel_lookup(id);
606: if (c == NULL) {
1.165 markus 607: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 608: return;
609: }
1.165 markus 610: c->confirm = fn;
1.121 markus 611: }
612: void
613: channel_register_cleanup(int id, channel_callback_fn *fn)
614: {
615: Channel *c = channel_lookup(id);
616: if (c == NULL) {
617: log("channel_register_cleanup: %d: bad id", id);
618: return;
619: }
1.131 markus 620: c->detach_user = fn;
1.121 markus 621: }
622: void
623: channel_cancel_cleanup(int id)
624: {
625: Channel *c = channel_lookup(id);
626: if (c == NULL) {
627: log("channel_cancel_cleanup: %d: bad id", id);
628: return;
1.52 markus 629: }
1.131 markus 630: c->detach_user = NULL;
1.121 markus 631: }
632: void
633: channel_register_filter(int id, channel_filter_fn *fn)
634: {
635: Channel *c = channel_lookup(id);
636: if (c == NULL) {
637: log("channel_register_filter: %d: bad id", id);
638: return;
1.52 markus 639: }
1.121 markus 640: c->input_filter = fn;
1.52 markus 641: }
642:
1.49 markus 643: void
1.121 markus 644: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 645: int extusage, int nonblock, u_int window_max)
1.1 deraadt 646: {
1.121 markus 647: Channel *c = channel_lookup(id);
648: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
649: fatal("channel_activate for non-larval channel %d.", id);
650: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
651: c->type = SSH_CHANNEL_OPEN;
1.168 markus 652: c->local_window = c->local_window_max = window_max;
1.121 markus 653: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
654: packet_put_int(c->remote_id);
655: packet_put_int(c->local_window);
656: packet_send();
1.1 deraadt 657: }
658:
1.27 markus 659: /*
1.41 markus 660: * 'channel_pre*' are called just before select() to add any bits relevant to
661: * channels in the select bitmasks.
662: */
663: /*
664: * 'channel_post*': perform any appropriate operations for channels which
665: * have events pending.
1.27 markus 666: */
1.41 markus 667: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
668: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
669: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
670:
1.127 itojun 671: static void
1.41 markus 672: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
673: {
674: FD_SET(c->sock, readset);
675: }
676:
1.127 itojun 677: static void
1.75 markus 678: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
679: {
680: debug3("channel %d: waiting for connection", c->self);
681: FD_SET(c->sock, writeset);
682: }
683:
1.127 itojun 684: static void
1.41 markus 685: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
686: {
687: if (buffer_len(&c->input) < packet_get_maxsize())
688: FD_SET(c->sock, readset);
689: if (buffer_len(&c->output) > 0)
690: FD_SET(c->sock, writeset);
691: }
1.1 deraadt 692:
1.127 itojun 693: static void
1.157 markus 694: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 695: {
1.157 markus 696: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 697:
1.44 markus 698: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 699: limit > 0 &&
700: buffer_len(&c->input) < limit)
1.44 markus 701: FD_SET(c->rfd, readset);
702: if (c->ostate == CHAN_OUTPUT_OPEN ||
703: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
704: if (buffer_len(&c->output) > 0) {
705: FD_SET(c->wfd, writeset);
706: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 707: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.172.2.3! jason 708: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
! 709: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 710: else
711: chan_obuf_empty(c);
1.44 markus 712: }
713: }
714: /** XXX check close conditions, too */
1.157 markus 715: if (compat20 && c->efd != -1) {
1.44 markus 716: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
717: buffer_len(&c->extended) > 0)
718: FD_SET(c->efd, writeset);
1.172 markus 719: else if (!(c->flags & CHAN_EOF_SENT) &&
720: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 721: buffer_len(&c->extended) < c->remote_window)
722: FD_SET(c->efd, readset);
723: }
724: }
725:
1.127 itojun 726: static void
1.41 markus 727: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
728: {
729: if (buffer_len(&c->input) == 0) {
730: packet_start(SSH_MSG_CHANNEL_CLOSE);
731: packet_put_int(c->remote_id);
732: packet_send();
733: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 734: debug("channel %d: closing after input drain.", c->self);
1.41 markus 735: }
736: }
737:
1.127 itojun 738: static void
1.41 markus 739: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
740: {
741: if (buffer_len(&c->output) == 0)
1.113 markus 742: chan_mark_dead(c);
1.49 markus 743: else
1.41 markus 744: FD_SET(c->sock, writeset);
745: }
746:
747: /*
748: * This is a special state for X11 authentication spoofing. An opened X11
749: * connection (when authentication spoofing is being done) remains in this
750: * state until the first packet has been completely read. The authentication
751: * data in that packet is then substituted by the real data if it matches the
752: * fake data, and the channel is put into normal mode.
1.51 markus 753: * XXX All this happens at the client side.
1.121 markus 754: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 755: */
1.127 itojun 756: static int
1.121 markus 757: x11_open_helper(Buffer *b)
1.1 deraadt 758: {
1.77 markus 759: u_char *ucp;
760: u_int proto_len, data_len;
1.25 markus 761:
1.41 markus 762: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 763: if (buffer_len(b) < 12)
1.41 markus 764: return 0;
765:
766: /* Parse the lengths of variable-length fields. */
1.155 stevesk 767: ucp = buffer_ptr(b);
1.41 markus 768: if (ucp[0] == 0x42) { /* Byte order MSB first. */
769: proto_len = 256 * ucp[6] + ucp[7];
770: data_len = 256 * ucp[8] + ucp[9];
771: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
772: proto_len = ucp[6] + 256 * ucp[7];
773: data_len = ucp[8] + 256 * ucp[9];
774: } else {
775: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 776: ucp[0]);
1.41 markus 777: return -1;
778: }
779:
780: /* Check if the whole packet is in buffer. */
1.121 markus 781: if (buffer_len(b) <
1.41 markus 782: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
783: return 0;
784:
785: /* Check if authentication protocol matches. */
786: if (proto_len != strlen(x11_saved_proto) ||
787: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
788: debug("X11 connection uses different authentication protocol.");
789: return -1;
790: }
791: /* Check if authentication data matches our fake data. */
792: if (data_len != x11_fake_data_len ||
793: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
794: x11_fake_data, x11_fake_data_len) != 0) {
795: debug("X11 auth data does not match fake data.");
796: return -1;
797: }
798: /* Check fake data length */
799: if (x11_fake_data_len != x11_saved_data_len) {
800: error("X11 fake_data_len %d != saved_data_len %d",
801: x11_fake_data_len, x11_saved_data_len);
802: return -1;
803: }
804: /*
805: * Received authentication protocol and data match
806: * our fake data. Substitute the fake data with real
807: * data.
808: */
809: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
810: x11_saved_data, x11_saved_data_len);
811: return 1;
812: }
813:
1.127 itojun 814: static void
1.41 markus 815: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
816: {
1.121 markus 817: int ret = x11_open_helper(&c->output);
1.41 markus 818: if (ret == 1) {
819: /* Start normal processing for the channel. */
820: c->type = SSH_CHANNEL_OPEN;
1.47 markus 821: channel_pre_open_13(c, readset, writeset);
1.41 markus 822: } else if (ret == -1) {
823: /*
824: * We have received an X11 connection that has bad
825: * authentication information.
826: */
1.98 millert 827: log("X11 connection rejected because of wrong authentication.");
1.41 markus 828: buffer_clear(&c->input);
829: buffer_clear(&c->output);
1.132 markus 830: channel_close_fd(&c->sock);
1.41 markus 831: c->sock = -1;
832: c->type = SSH_CHANNEL_CLOSED;
833: packet_start(SSH_MSG_CHANNEL_CLOSE);
834: packet_put_int(c->remote_id);
835: packet_send();
836: }
837: }
1.25 markus 838:
1.127 itojun 839: static void
1.51 markus 840: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 841: {
1.121 markus 842: int ret = x11_open_helper(&c->output);
1.133 markus 843:
844: /* c->force_drain = 1; */
845:
1.41 markus 846: if (ret == 1) {
847: c->type = SSH_CHANNEL_OPEN;
1.157 markus 848: channel_pre_open(c, readset, writeset);
1.41 markus 849: } else if (ret == -1) {
1.156 markus 850: log("X11 connection rejected because of wrong authentication.");
1.41 markus 851: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 852: chan_read_failed(c);
853: buffer_clear(&c->input);
854: chan_ibuf_empty(c);
855: buffer_clear(&c->output);
856: /* for proto v1, the peer will send an IEOF */
857: if (compat20)
858: chan_write_failed(c);
859: else
860: c->type = SSH_CHANNEL_OPEN;
1.41 markus 861: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
862: }
863: }
1.25 markus 864:
1.104 markus 865: /* try to decode a socks4 header */
1.127 itojun 866: static int
1.104 markus 867: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 868: {
869: u_char *p, *host;
1.109 markus 870: int len, have, i, found;
1.148 deraadt 871: char username[256];
1.103 markus 872: struct {
873: u_int8_t version;
874: u_int8_t command;
875: u_int16_t dest_port;
1.104 markus 876: struct in_addr dest_addr;
1.103 markus 877: } s4_req, s4_rsp;
878:
1.104 markus 879: debug2("channel %d: decode socks4", c->self);
1.109 markus 880:
881: have = buffer_len(&c->input);
882: len = sizeof(s4_req);
883: if (have < len)
884: return 0;
885: p = buffer_ptr(&c->input);
886: for (found = 0, i = len; i < have; i++) {
887: if (p[i] == '\0') {
888: found = 1;
889: break;
890: }
891: if (i > 1024) {
892: /* the peer is probably sending garbage */
893: debug("channel %d: decode socks4: too long",
894: c->self);
895: return -1;
896: }
897: }
898: if (!found)
899: return 0;
1.103 markus 900: buffer_get(&c->input, (char *)&s4_req.version, 1);
901: buffer_get(&c->input, (char *)&s4_req.command, 1);
902: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 903: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 904: have = buffer_len(&c->input);
1.103 markus 905: p = buffer_ptr(&c->input);
906: len = strlen(p);
1.106 markus 907: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 908: if (len > have)
1.104 markus 909: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 910: c->self, len, have);
911: strlcpy(username, p, sizeof(username));
912: buffer_consume(&c->input, len);
913: buffer_consume(&c->input, 1); /* trailing '\0' */
914:
1.104 markus 915: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 916: strlcpy(c->path, host, sizeof(c->path));
917: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 918:
1.106 markus 919: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
920: c->self, host, c->host_port, s4_req.command);
1.103 markus 921:
1.104 markus 922: if (s4_req.command != 1) {
923: debug("channel %d: cannot handle: socks4 cn %d",
924: c->self, s4_req.command);
925: return -1;
1.103 markus 926: }
1.104 markus 927: s4_rsp.version = 0; /* vn: 0 for reply */
928: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 929: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 930: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 931: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 932: return 1;
933: }
934:
935: /* dynamic port forwarding */
1.127 itojun 936: static void
1.104 markus 937: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
938: {
939: u_char *p;
940: int have, ret;
1.103 markus 941:
1.104 markus 942: have = buffer_len(&c->input);
1.137 markus 943: c->delayed = 0;
1.104 markus 944: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 945: /* buffer_dump(&c->input); */
1.104 markus 946: /* check if the fixed size part of the packet is in buffer. */
947: if (have < 4) {
948: /* need more */
949: FD_SET(c->sock, readset);
950: return;
951: }
952: /* try to guess the protocol */
953: p = buffer_ptr(&c->input);
954: switch (p[0]) {
955: case 0x04:
956: ret = channel_decode_socks4(c, readset, writeset);
957: break;
958: default:
959: ret = -1;
960: break;
961: }
962: if (ret < 0) {
1.113 markus 963: chan_mark_dead(c);
1.104 markus 964: } else if (ret == 0) {
965: debug2("channel %d: pre_dynamic: need more", c->self);
966: /* need more */
967: FD_SET(c->sock, readset);
968: } else {
969: /* switch to the next state */
970: c->type = SSH_CHANNEL_OPENING;
971: port_open_helper(c, "direct-tcpip");
972: }
1.103 markus 973: }
974:
1.41 markus 975: /* This is our fake X11 server socket. */
1.127 itojun 976: static void
1.41 markus 977: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
978: {
1.113 markus 979: Channel *nc;
1.41 markus 980: struct sockaddr addr;
1.162 stevesk 981: int newsock;
1.41 markus 982: socklen_t addrlen;
1.85 markus 983: char buf[16384], *remote_ipaddr;
1.51 markus 984: int remote_port;
1.25 markus 985:
1.41 markus 986: if (FD_ISSET(c->sock, readset)) {
987: debug("X11 connection requested.");
988: addrlen = sizeof(addr);
989: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 990: if (c->single_connection) {
991: debug("single_connection: closing X11 listener.");
992: channel_close_fd(&c->sock);
993: chan_mark_dead(c);
994: }
1.41 markus 995: if (newsock < 0) {
996: error("accept: %.100s", strerror(errno));
997: return;
998: }
1.162 stevesk 999: set_nodelay(newsock);
1.85 markus 1000: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1001: remote_port = get_peer_port(newsock);
1.41 markus 1002: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1003: remote_ipaddr, remote_port);
1.51 markus 1004:
1.113 markus 1005: nc = channel_new("accepted x11 socket",
1.51 markus 1006: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1007: c->local_window_max, c->local_maxpacket,
1.71 markus 1008: 0, xstrdup(buf), 1);
1.51 markus 1009: if (compat20) {
1010: packet_start(SSH2_MSG_CHANNEL_OPEN);
1011: packet_put_cstring("x11");
1.113 markus 1012: packet_put_int(nc->self);
1.149 markus 1013: packet_put_int(nc->local_window_max);
1014: packet_put_int(nc->local_maxpacket);
1.85 markus 1015: /* originator ipaddr and port */
1016: packet_put_cstring(remote_ipaddr);
1.57 markus 1017: if (datafellows & SSH_BUG_X11FWD) {
1018: debug("ssh2 x11 bug compat mode");
1019: } else {
1020: packet_put_int(remote_port);
1021: }
1.51 markus 1022: packet_send();
1023: } else {
1024: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1025: packet_put_int(nc->self);
1.121 markus 1026: if (packet_get_protocol_flags() &
1027: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1028: packet_put_cstring(buf);
1.51 markus 1029: packet_send();
1030: }
1.85 markus 1031: xfree(remote_ipaddr);
1.41 markus 1032: }
1033: }
1.25 markus 1034:
1.127 itojun 1035: static void
1.103 markus 1036: port_open_helper(Channel *c, char *rtype)
1037: {
1038: int direct;
1039: char buf[1024];
1040: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1041: u_short remote_port = get_peer_port(c->sock);
1042:
1043: direct = (strcmp(rtype, "direct-tcpip") == 0);
1044:
1045: snprintf(buf, sizeof buf,
1046: "%s: listening port %d for %.100s port %d, "
1047: "connect from %.200s port %d",
1048: rtype, c->listening_port, c->path, c->host_port,
1049: remote_ipaddr, remote_port);
1050:
1051: xfree(c->remote_name);
1052: c->remote_name = xstrdup(buf);
1053:
1054: if (compat20) {
1055: packet_start(SSH2_MSG_CHANNEL_OPEN);
1056: packet_put_cstring(rtype);
1057: packet_put_int(c->self);
1058: packet_put_int(c->local_window_max);
1059: packet_put_int(c->local_maxpacket);
1060: if (direct) {
1061: /* target host, port */
1062: packet_put_cstring(c->path);
1063: packet_put_int(c->host_port);
1064: } else {
1065: /* listen address, port */
1066: packet_put_cstring(c->path);
1067: packet_put_int(c->listening_port);
1068: }
1069: /* originator host and port */
1070: packet_put_cstring(remote_ipaddr);
1071: packet_put_int(remote_port);
1072: packet_send();
1073: } else {
1074: packet_start(SSH_MSG_PORT_OPEN);
1075: packet_put_int(c->self);
1076: packet_put_cstring(c->path);
1077: packet_put_int(c->host_port);
1.121 markus 1078: if (packet_get_protocol_flags() &
1079: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1080: packet_put_cstring(c->remote_name);
1081: packet_send();
1082: }
1083: xfree(remote_ipaddr);
1084: }
1085:
1.41 markus 1086: /*
1087: * This socket is listening for connections to a forwarded TCP/IP port.
1088: */
1.127 itojun 1089: static void
1.41 markus 1090: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1091: {
1.103 markus 1092: Channel *nc;
1.41 markus 1093: struct sockaddr addr;
1.113 markus 1094: int newsock, nextstate;
1.41 markus 1095: socklen_t addrlen;
1.103 markus 1096: char *rtype;
1.73 markus 1097:
1.41 markus 1098: if (FD_ISSET(c->sock, readset)) {
1099: debug("Connection to port %d forwarding "
1100: "to %.100s port %d requested.",
1101: c->listening_port, c->path, c->host_port);
1.103 markus 1102:
1.137 markus 1103: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1104: nextstate = SSH_CHANNEL_OPENING;
1105: rtype = "forwarded-tcpip";
1106: } else {
1107: if (c->host_port == 0) {
1108: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1109: rtype = "dynamic-tcpip";
1.137 markus 1110: } else {
1111: nextstate = SSH_CHANNEL_OPENING;
1112: rtype = "direct-tcpip";
1113: }
1114: }
1.103 markus 1115:
1.41 markus 1116: addrlen = sizeof(addr);
1117: newsock = accept(c->sock, &addr, &addrlen);
1118: if (newsock < 0) {
1119: error("accept: %.100s", strerror(errno));
1120: return;
1121: }
1.169 stevesk 1122: set_nodelay(newsock);
1.113 markus 1123: nc = channel_new(rtype,
1.103 markus 1124: nextstate, newsock, newsock, -1,
1.41 markus 1125: c->local_window_max, c->local_maxpacket,
1.103 markus 1126: 0, xstrdup(rtype), 1);
1127: nc->listening_port = c->listening_port;
1128: nc->host_port = c->host_port;
1129: strlcpy(nc->path, c->path, sizeof(nc->path));
1130:
1.137 markus 1131: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1132: /*
1133: * do not call the channel_post handler until
1134: * this flag has been reset by a pre-handler.
1135: * otherwise the FD_ISSET calls might overflow
1136: */
1137: nc->delayed = 1;
1138: } else {
1.103 markus 1139: port_open_helper(nc, rtype);
1.137 markus 1140: }
1.41 markus 1141: }
1142: }
1.25 markus 1143:
1.41 markus 1144: /*
1145: * This is the authentication agent socket listening for connections from
1146: * clients.
1147: */
1.127 itojun 1148: static void
1.41 markus 1149: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1150: {
1.113 markus 1151: Channel *nc;
1.121 markus 1152: char *name;
1.113 markus 1153: int newsock;
1.41 markus 1154: struct sockaddr addr;
1155: socklen_t addrlen;
1.25 markus 1156:
1.41 markus 1157: if (FD_ISSET(c->sock, readset)) {
1158: addrlen = sizeof(addr);
1159: newsock = accept(c->sock, &addr, &addrlen);
1160: if (newsock < 0) {
1161: error("accept from auth socket: %.100s", strerror(errno));
1162: return;
1163: }
1.121 markus 1164: name = xstrdup("accepted auth socket");
1.113 markus 1165: nc = channel_new("accepted auth socket",
1.73 markus 1166: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1167: c->local_window_max, c->local_maxpacket,
1.121 markus 1168: 0, name, 1);
1.73 markus 1169: if (compat20) {
1170: packet_start(SSH2_MSG_CHANNEL_OPEN);
1171: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1172: packet_put_int(nc->self);
1.73 markus 1173: packet_put_int(c->local_window_max);
1174: packet_put_int(c->local_maxpacket);
1175: } else {
1176: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1177: packet_put_int(nc->self);
1.73 markus 1178: }
1.41 markus 1179: packet_send();
1180: }
1181: }
1.25 markus 1182:
1.127 itojun 1183: static void
1.75 markus 1184: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1185: {
1.114 markus 1186: int err = 0;
1.129 stevesk 1187: socklen_t sz = sizeof(err);
1.114 markus 1188:
1.75 markus 1189: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1190: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1191: err = errno;
1192: error("getsockopt SO_ERROR failed");
1193: }
1194: if (err == 0) {
1195: debug("channel %d: connected", c->self);
1196: c->type = SSH_CHANNEL_OPEN;
1197: if (compat20) {
1198: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1199: packet_put_int(c->remote_id);
1200: packet_put_int(c->self);
1201: packet_put_int(c->local_window);
1202: packet_put_int(c->local_maxpacket);
1203: } else {
1204: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1205: packet_put_int(c->remote_id);
1206: packet_put_int(c->self);
1207: }
1.75 markus 1208: } else {
1.114 markus 1209: debug("channel %d: not connected: %s",
1210: c->self, strerror(err));
1211: if (compat20) {
1212: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1213: packet_put_int(c->remote_id);
1214: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1215: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1216: packet_put_cstring(strerror(err));
1217: packet_put_cstring("");
1218: }
1.75 markus 1219: } else {
1.114 markus 1220: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1221: packet_put_int(c->remote_id);
1.75 markus 1222: }
1.114 markus 1223: chan_mark_dead(c);
1.75 markus 1224: }
1.114 markus 1225: packet_send();
1.75 markus 1226: }
1227: }
1228:
1.127 itojun 1229: static int
1.41 markus 1230: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1231: {
1232: char buf[16*1024];
1233: int len;
1.25 markus 1234:
1.118 markus 1235: if (c->rfd != -1 &&
1.41 markus 1236: FD_ISSET(c->rfd, readset)) {
1237: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1238: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1239: return 1;
1.41 markus 1240: if (len <= 0) {
1.51 markus 1241: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1242: c->self, c->rfd, len);
1.104 markus 1243: if (c->type != SSH_CHANNEL_OPEN) {
1244: debug("channel %d: not open", c->self);
1.113 markus 1245: chan_mark_dead(c);
1.103 markus 1246: return -1;
1.104 markus 1247: } else if (compat13) {
1.158 markus 1248: buffer_clear(&c->output);
1.41 markus 1249: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1250: debug("channel %d: input draining.", c->self);
1.25 markus 1251: } else {
1.41 markus 1252: chan_read_failed(c);
1.25 markus 1253: }
1.41 markus 1254: return -1;
1255: }
1.143 deraadt 1256: if (c->input_filter != NULL) {
1.66 markus 1257: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1258: debug("channel %d: filter stops", c->self);
1.65 markus 1259: chan_read_failed(c);
1260: }
1261: } else {
1262: buffer_append(&c->input, buf, len);
1263: }
1.41 markus 1264: }
1265: return 1;
1266: }
1.127 itojun 1267: static int
1.41 markus 1268: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1269: {
1.95 markus 1270: struct termios tio;
1.134 markus 1271: u_char *data;
1272: u_int dlen;
1.41 markus 1273: int len;
1.25 markus 1274:
1.41 markus 1275: /* Send buffered output data to the socket. */
1.118 markus 1276: if (c->wfd != -1 &&
1.41 markus 1277: FD_ISSET(c->wfd, writeset) &&
1278: buffer_len(&c->output) > 0) {
1.134 markus 1279: data = buffer_ptr(&c->output);
1280: dlen = buffer_len(&c->output);
1281: len = write(c->wfd, data, dlen);
1.53 markus 1282: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1283: return 1;
1.41 markus 1284: if (len <= 0) {
1.104 markus 1285: if (c->type != SSH_CHANNEL_OPEN) {
1286: debug("channel %d: not open", c->self);
1.113 markus 1287: chan_mark_dead(c);
1.104 markus 1288: return -1;
1289: } else if (compat13) {
1.158 markus 1290: buffer_clear(&c->output);
1.121 markus 1291: debug("channel %d: input draining.", c->self);
1.41 markus 1292: c->type = SSH_CHANNEL_INPUT_DRAINING;
1293: } else {
1294: chan_write_failed(c);
1295: }
1296: return -1;
1.91 markus 1297: }
1.134 markus 1298: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1299: if (tcgetattr(c->wfd, &tio) == 0 &&
1300: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1301: /*
1302: * Simulate echo to reduce the impact of
1.96 markus 1303: * traffic analysis. We need to match the
1.95 markus 1304: * size of a SSH2_MSG_CHANNEL_DATA message
1305: * (4 byte channel id + data)
1.91 markus 1306: */
1.95 markus 1307: packet_send_ignore(4 + len);
1.91 markus 1308: packet_send();
1309: }
1.25 markus 1310: }
1.41 markus 1311: buffer_consume(&c->output, len);
1.44 markus 1312: if (compat20 && len > 0) {
1313: c->local_consumed += len;
1314: }
1315: }
1316: return 1;
1317: }
1.127 itojun 1318: static int
1.44 markus 1319: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1320: {
1321: char buf[16*1024];
1322: int len;
1323:
1.45 markus 1324: /** XXX handle drain efd, too */
1.44 markus 1325: if (c->efd != -1) {
1326: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1327: FD_ISSET(c->efd, writeset) &&
1328: buffer_len(&c->extended) > 0) {
1329: len = write(c->efd, buffer_ptr(&c->extended),
1330: buffer_len(&c->extended));
1.70 markus 1331: debug2("channel %d: written %d to efd %d",
1.44 markus 1332: c->self, len, c->efd);
1.93 markus 1333: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1334: return 1;
1335: if (len <= 0) {
1336: debug2("channel %d: closing write-efd %d",
1337: c->self, c->efd);
1.132 markus 1338: channel_close_fd(&c->efd);
1.93 markus 1339: } else {
1.44 markus 1340: buffer_consume(&c->extended, len);
1341: c->local_consumed += len;
1342: }
1343: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1344: FD_ISSET(c->efd, readset)) {
1345: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1346: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1347: c->self, len, c->efd);
1.93 markus 1348: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1349: return 1;
1350: if (len <= 0) {
1351: debug2("channel %d: closing read-efd %d",
1.45 markus 1352: c->self, c->efd);
1.132 markus 1353: channel_close_fd(&c->efd);
1.93 markus 1354: } else {
1.44 markus 1355: buffer_append(&c->extended, buf, len);
1.93 markus 1356: }
1.44 markus 1357: }
1358: }
1359: return 1;
1360: }
1.127 itojun 1361: static int
1.93 markus 1362: channel_check_window(Channel *c)
1.44 markus 1363: {
1.104 markus 1364: if (c->type == SSH_CHANNEL_OPEN &&
1365: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1366: c->local_window < c->local_window_max/2 &&
1367: c->local_consumed > 0) {
1368: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1369: packet_put_int(c->remote_id);
1370: packet_put_int(c->local_consumed);
1371: packet_send();
1.70 markus 1372: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1373: c->self, c->local_window,
1374: c->local_consumed);
1375: c->local_window += c->local_consumed;
1376: c->local_consumed = 0;
1.1 deraadt 1377: }
1.41 markus 1378: return 1;
1.1 deraadt 1379: }
1380:
1.127 itojun 1381: static void
1.157 markus 1382: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1383: {
1.137 markus 1384: if (c->delayed)
1385: return;
1.41 markus 1386: channel_handle_rfd(c, readset, writeset);
1387: channel_handle_wfd(c, readset, writeset);
1.157 markus 1388: if (!compat20)
1.137 markus 1389: return;
1.44 markus 1390: channel_handle_efd(c, readset, writeset);
1.93 markus 1391: channel_check_window(c);
1.44 markus 1392: }
1393:
1.127 itojun 1394: static void
1.41 markus 1395: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1396: {
1.41 markus 1397: int len;
1398: /* Send buffered output data to the socket. */
1399: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1400: len = write(c->sock, buffer_ptr(&c->output),
1401: buffer_len(&c->output));
1402: if (len <= 0)
1.158 markus 1403: buffer_clear(&c->output);
1.41 markus 1404: else
1405: buffer_consume(&c->output, len);
1406: }
1407: }
1.25 markus 1408:
1.127 itojun 1409: static void
1.44 markus 1410: channel_handler_init_20(void)
1411: {
1.157 markus 1412: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1413: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1414: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1415: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1416: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1417: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1418: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1419: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1420:
1.157 markus 1421: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1422: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1423: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1424: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1425: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1426: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1427: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1428: }
1429:
1.127 itojun 1430: static void
1.41 markus 1431: channel_handler_init_13(void)
1432: {
1433: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1434: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1435: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1436: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1437: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1438: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1439: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1440: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1441: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1442:
1.157 markus 1443: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1444: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1445: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1446: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1447: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1448: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1449: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1450: }
1.25 markus 1451:
1.127 itojun 1452: static void
1.41 markus 1453: channel_handler_init_15(void)
1454: {
1.157 markus 1455: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1456: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1457: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1458: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1459: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1460: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1461: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1462:
1.41 markus 1463: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1464: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1465: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1466: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1467: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1468: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1469: }
1.27 markus 1470:
1.127 itojun 1471: static void
1.41 markus 1472: channel_handler_init(void)
1473: {
1474: int i;
1.148 deraadt 1475: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1476: channel_pre[i] = NULL;
1477: channel_post[i] = NULL;
1478: }
1.44 markus 1479: if (compat20)
1480: channel_handler_init_20();
1481: else if (compat13)
1.41 markus 1482: channel_handler_init_13();
1483: else
1484: channel_handler_init_15();
1485: }
1.25 markus 1486:
1.140 markus 1487: /* gc dead channels */
1488: static void
1489: channel_garbage_collect(Channel *c)
1490: {
1491: if (c == NULL)
1492: return;
1493: if (c->detach_user != NULL) {
1494: if (!chan_is_dead(c, 0))
1495: return;
1496: debug("channel %d: gc: notify user", c->self);
1497: c->detach_user(c->self, NULL);
1498: /* if we still have a callback */
1499: if (c->detach_user != NULL)
1500: return;
1501: debug("channel %d: gc: user detached", c->self);
1502: }
1503: if (!chan_is_dead(c, 1))
1504: return;
1505: debug("channel %d: garbage collecting", c->self);
1506: channel_free(c);
1507: }
1508:
1.127 itojun 1509: static void
1.41 markus 1510: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1511: {
1512: static int did_init = 0;
1513: int i;
1514: Channel *c;
1.25 markus 1515:
1.41 markus 1516: if (!did_init) {
1517: channel_handler_init();
1518: did_init = 1;
1519: }
1520: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1521: c = channels[i];
1522: if (c == NULL)
1.41 markus 1523: continue;
1.118 markus 1524: if (ftab[c->type] != NULL)
1525: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1526: channel_garbage_collect(c);
1.1 deraadt 1527: }
1528: }
1529:
1.121 markus 1530: /*
1531: * Allocate/update select bitmasks and add any bits relevant to channels in
1532: * select bitmasks.
1533: */
1.49 markus 1534: void
1.100 markus 1535: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1536: int *nallocp, int rekeying)
1.41 markus 1537: {
1.84 markus 1538: int n;
1539: u_int sz;
1540:
1541: n = MAX(*maxfdp, channel_max_fd);
1542:
1543: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1544: /* perhaps check sz < nalloc/2 and shrink? */
1545: if (*readsetp == NULL || sz > *nallocp) {
1546: *readsetp = xrealloc(*readsetp, sz);
1547: *writesetp = xrealloc(*writesetp, sz);
1548: *nallocp = sz;
1.84 markus 1549: }
1.132 markus 1550: *maxfdp = n;
1.84 markus 1551: memset(*readsetp, 0, sz);
1552: memset(*writesetp, 0, sz);
1553:
1.100 markus 1554: if (!rekeying)
1555: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1556: }
1557:
1.121 markus 1558: /*
1559: * After select, perform any appropriate operations for channels which have
1560: * events pending.
1561: */
1.49 markus 1562: void
1.41 markus 1563: channel_after_select(fd_set * readset, fd_set * writeset)
1564: {
1565: channel_handler(channel_post, readset, writeset);
1566: }
1567:
1.121 markus 1568:
1.84 markus 1569: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1570:
1.49 markus 1571: void
1.142 itojun 1572: channel_output_poll(void)
1.1 deraadt 1573: {
1.41 markus 1574: Channel *c;
1.172.2.3! jason 1575: int i;
! 1576: u_int len;
1.1 deraadt 1577:
1.25 markus 1578: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1579: c = channels[i];
1580: if (c == NULL)
1581: continue;
1.37 markus 1582:
1.121 markus 1583: /*
1584: * We are only interested in channels that can have buffered
1585: * incoming data.
1586: */
1.37 markus 1587: if (compat13) {
1.41 markus 1588: if (c->type != SSH_CHANNEL_OPEN &&
1589: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1590: continue;
1591: } else {
1.41 markus 1592: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1593: continue;
1594: }
1.46 markus 1595: if (compat20 &&
1596: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1597: /* XXX is this true? */
1.140 markus 1598: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1599: continue;
1600: }
1.25 markus 1601:
1602: /* Get the amount of buffered data for this channel. */
1.93 markus 1603: if ((c->istate == CHAN_INPUT_OPEN ||
1604: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1605: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1606: /*
1607: * Send some data for the other side over the secure
1608: * connection.
1609: */
1.44 markus 1610: if (compat20) {
1611: if (len > c->remote_window)
1612: len = c->remote_window;
1613: if (len > c->remote_maxpacket)
1614: len = c->remote_maxpacket;
1.25 markus 1615: } else {
1.44 markus 1616: if (packet_is_interactive()) {
1617: if (len > 1024)
1618: len = 512;
1619: } else {
1620: /* Keep the packets at reasonable size. */
1621: if (len > packet_get_maxsize()/2)
1622: len = packet_get_maxsize()/2;
1623: }
1.25 markus 1624: }
1.41 markus 1625: if (len > 0) {
1.44 markus 1626: packet_start(compat20 ?
1627: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1628: packet_put_int(c->remote_id);
1629: packet_put_string(buffer_ptr(&c->input), len);
1630: packet_send();
1631: buffer_consume(&c->input, len);
1632: c->remote_window -= len;
1633: }
1634: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1635: if (compat13)
1636: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1637: /*
1638: * input-buffer is empty and read-socket shutdown:
1.172 markus 1639: * tell peer, that we will not send more data: send IEOF.
1640: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1641: */
1.172 markus 1642: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.172.2.3! jason 1643: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
! 1644: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1645: else
1646: chan_ibuf_empty(c);
1.25 markus 1647: }
1.44 markus 1648: /* Send extended data, i.e. stderr */
1649: if (compat20 &&
1.172 markus 1650: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1651: c->remote_window > 0 &&
1652: (len = buffer_len(&c->extended)) > 0 &&
1653: c->extended_usage == CHAN_EXTENDED_READ) {
1.172.2.3! jason 1654: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1655: c->self, c->remote_window, buffer_len(&c->extended),
1656: c->extended_usage);
1.44 markus 1657: if (len > c->remote_window)
1658: len = c->remote_window;
1659: if (len > c->remote_maxpacket)
1660: len = c->remote_maxpacket;
1661: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1662: packet_put_int(c->remote_id);
1663: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1664: packet_put_string(buffer_ptr(&c->extended), len);
1665: packet_send();
1666: buffer_consume(&c->extended, len);
1667: c->remote_window -= len;
1.93 markus 1668: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1669: }
1.25 markus 1670: }
1.1 deraadt 1671: }
1672:
1.121 markus 1673:
1674: /* -- protocol input */
1.1 deraadt 1675:
1.49 markus 1676: void
1.154 markus 1677: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1678: {
1.37 markus 1679: int id;
1.25 markus 1680: char *data;
1.77 markus 1681: u_int data_len;
1.41 markus 1682: Channel *c;
1.25 markus 1683:
1684: /* Get the channel number and verify it. */
1.37 markus 1685: id = packet_get_int();
1.41 markus 1686: c = channel_lookup(id);
1687: if (c == NULL)
1.37 markus 1688: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1689:
1690: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1691: if (c->type != SSH_CHANNEL_OPEN &&
1692: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1693: return;
1694:
1695: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1696: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1697: return;
1698:
1699: /* Get the data. */
1700: data = packet_get_string(&data_len);
1.41 markus 1701:
1.143 deraadt 1702: if (compat20) {
1.44 markus 1703: if (data_len > c->local_maxpacket) {
1704: log("channel %d: rcvd big packet %d, maxpack %d",
1705: c->self, data_len, c->local_maxpacket);
1706: }
1707: if (data_len > c->local_window) {
1708: log("channel %d: rcvd too much data %d, win %d",
1709: c->self, data_len, c->local_window);
1710: xfree(data);
1711: return;
1712: }
1713: c->local_window -= data_len;
1714: }
1.152 markus 1715: packet_check_eom();
1.41 markus 1716: buffer_append(&c->output, data, data_len);
1.25 markus 1717: xfree(data);
1.1 deraadt 1718: }
1.121 markus 1719:
1.49 markus 1720: void
1.154 markus 1721: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1722: {
1723: int id;
1724: char *data;
1.172.2.3! jason 1725: u_int data_len, tcode;
1.44 markus 1726: Channel *c;
1727:
1728: /* Get the channel number and verify it. */
1729: id = packet_get_int();
1730: c = channel_lookup(id);
1731:
1732: if (c == NULL)
1733: packet_disconnect("Received extended_data for bad channel %d.", id);
1734: if (c->type != SSH_CHANNEL_OPEN) {
1735: log("channel %d: ext data for non open", id);
1736: return;
1.172 markus 1737: }
1738: if (c->flags & CHAN_EOF_RCVD) {
1739: if (datafellows & SSH_BUG_EXTEOF)
1740: debug("channel %d: accepting ext data after eof", id);
1741: else
1742: packet_disconnect("Received extended_data after EOF "
1743: "on channel %d.", id);
1.44 markus 1744: }
1745: tcode = packet_get_int();
1746: if (c->efd == -1 ||
1747: c->extended_usage != CHAN_EXTENDED_WRITE ||
1748: tcode != SSH2_EXTENDED_DATA_STDERR) {
1749: log("channel %d: bad ext data", c->self);
1750: return;
1751: }
1752: data = packet_get_string(&data_len);
1.152 markus 1753: packet_check_eom();
1.44 markus 1754: if (data_len > c->local_window) {
1755: log("channel %d: rcvd too much extended_data %d, win %d",
1756: c->self, data_len, c->local_window);
1757: xfree(data);
1758: return;
1759: }
1.70 markus 1760: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1761: c->local_window -= data_len;
1762: buffer_append(&c->extended, data, data_len);
1763: xfree(data);
1764: }
1765:
1.49 markus 1766: void
1.154 markus 1767: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1768: {
1769: int id;
1770: Channel *c;
1771:
1772: id = packet_get_int();
1.152 markus 1773: packet_check_eom();
1.41 markus 1774: c = channel_lookup(id);
1775: if (c == NULL)
1776: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1777: chan_rcvd_ieof(c);
1.133 markus 1778:
1779: /* XXX force input close */
1.156 markus 1780: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1781: debug("channel %d: FORCE input drain", c->self);
1782: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1783: if (buffer_len(&c->input) == 0)
1784: chan_ibuf_empty(c);
1.133 markus 1785: }
1786:
1.41 markus 1787: }
1.1 deraadt 1788:
1.49 markus 1789: void
1.154 markus 1790: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1791: {
1.41 markus 1792: int id;
1793: Channel *c;
1.1 deraadt 1794:
1.41 markus 1795: id = packet_get_int();
1.152 markus 1796: packet_check_eom();
1.41 markus 1797: c = channel_lookup(id);
1798: if (c == NULL)
1799: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1800:
1801: /*
1802: * Send a confirmation that we have closed the channel and no more
1803: * data is coming for it.
1804: */
1.25 markus 1805: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1806: packet_put_int(c->remote_id);
1.25 markus 1807: packet_send();
1808:
1.27 markus 1809: /*
1810: * If the channel is in closed state, we have sent a close request,
1811: * and the other side will eventually respond with a confirmation.
1812: * Thus, we cannot free the channel here, because then there would be
1813: * no-one to receive the confirmation. The channel gets freed when
1814: * the confirmation arrives.
1815: */
1.41 markus 1816: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1817: /*
1818: * Not a closed channel - mark it as draining, which will
1819: * cause it to be freed later.
1820: */
1.158 markus 1821: buffer_clear(&c->input);
1.41 markus 1822: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1823: }
1.1 deraadt 1824: }
1825:
1.41 markus 1826: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1827: void
1.154 markus 1828: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1829: {
1830: int id = packet_get_int();
1831: Channel *c = channel_lookup(id);
1.151 markus 1832:
1.152 markus 1833: packet_check_eom();
1.41 markus 1834: if (c == NULL)
1835: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1836: chan_rcvd_oclose(c);
1837: }
1.1 deraadt 1838:
1.49 markus 1839: void
1.154 markus 1840: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1841: {
1.41 markus 1842: int id = packet_get_int();
1843: Channel *c = channel_lookup(id);
1.1 deraadt 1844:
1.152 markus 1845: packet_check_eom();
1.41 markus 1846: if (c == NULL)
1847: packet_disconnect("Received close confirmation for "
1848: "out-of-range channel %d.", id);
1849: if (c->type != SSH_CHANNEL_CLOSED)
1850: packet_disconnect("Received close confirmation for "
1851: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1852: channel_free(c);
1.1 deraadt 1853: }
1854:
1.49 markus 1855: void
1.154 markus 1856: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1857: {
1.41 markus 1858: int id, remote_id;
1859: Channel *c;
1.1 deraadt 1860:
1.41 markus 1861: id = packet_get_int();
1862: c = channel_lookup(id);
1.25 markus 1863:
1.41 markus 1864: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1865: packet_disconnect("Received open confirmation for "
1866: "non-opening channel %d.", id);
1867: remote_id = packet_get_int();
1.27 markus 1868: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1869: c->remote_id = remote_id;
1870: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1871:
1872: if (compat20) {
1873: c->remote_window = packet_get_int();
1874: c->remote_maxpacket = packet_get_int();
1.165 markus 1875: if (c->confirm) {
1.70 markus 1876: debug2("callback start");
1.165 markus 1877: c->confirm(c->self, NULL);
1.70 markus 1878: debug2("callback done");
1.44 markus 1879: }
1.172.2.3! jason 1880: debug("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 1881: c->remote_window, c->remote_maxpacket);
1882: }
1.152 markus 1883: packet_check_eom();
1.1 deraadt 1884: }
1885:
1.127 itojun 1886: static char *
1.114 markus 1887: reason2txt(int reason)
1888: {
1.143 deraadt 1889: switch (reason) {
1.114 markus 1890: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1891: return "administratively prohibited";
1892: case SSH2_OPEN_CONNECT_FAILED:
1893: return "connect failed";
1894: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1895: return "unknown channel type";
1896: case SSH2_OPEN_RESOURCE_SHORTAGE:
1897: return "resource shortage";
1898: }
1.117 stevesk 1899: return "unknown reason";
1.114 markus 1900: }
1901:
1.49 markus 1902: void
1.154 markus 1903: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1904: {
1.86 markus 1905: int id, reason;
1906: char *msg = NULL, *lang = NULL;
1.41 markus 1907: Channel *c;
1908:
1909: id = packet_get_int();
1910: c = channel_lookup(id);
1.25 markus 1911:
1.41 markus 1912: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1913: packet_disconnect("Received open failure for "
1914: "non-opening channel %d.", id);
1.44 markus 1915: if (compat20) {
1.86 markus 1916: reason = packet_get_int();
1.110 markus 1917: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1918: msg = packet_get_string(NULL);
1919: lang = packet_get_string(NULL);
1920: }
1.114 markus 1921: log("channel %d: open failed: %s%s%s", id,
1922: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1923: if (msg != NULL)
1924: xfree(msg);
1925: if (lang != NULL)
1926: xfree(lang);
1.44 markus 1927: }
1.152 markus 1928: packet_check_eom();
1.25 markus 1929: /* Free the channel. This will also close the socket. */
1.113 markus 1930: channel_free(c);
1.44 markus 1931: }
1932:
1.121 markus 1933: void
1.154 markus 1934: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1935: {
1936: Channel *c;
1.172.2.3! jason 1937: int id;
! 1938: u_int adjust;
1.121 markus 1939:
1940: if (!compat20)
1941: return;
1942:
1943: /* Get the channel number and verify it. */
1944: id = packet_get_int();
1945: c = channel_lookup(id);
1.1 deraadt 1946:
1.121 markus 1947: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1948: log("Received window adjust for "
1949: "non-open channel %d.", id);
1950: return;
1951: }
1952: adjust = packet_get_int();
1.152 markus 1953: packet_check_eom();
1.172.2.3! jason 1954: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 1955: c->remote_window += adjust;
1956: }
1.1 deraadt 1957:
1.121 markus 1958: void
1.154 markus 1959: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1960: {
1.121 markus 1961: Channel *c = NULL;
1962: u_short host_port;
1963: char *host, *originator_string;
1964: int remote_id, sock = -1;
1965:
1966: remote_id = packet_get_int();
1967: host = packet_get_string(NULL);
1968: host_port = packet_get_int();
1.25 markus 1969:
1.121 markus 1970: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1971: originator_string = packet_get_string(NULL);
1972: } else {
1973: originator_string = xstrdup("unknown (remote did not supply name)");
1974: }
1.152 markus 1975: packet_check_eom();
1.121 markus 1976: sock = channel_connect_to(host, host_port);
1977: if (sock != -1) {
1978: c = channel_new("connected socket",
1979: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1980: originator_string, 1);
1.167 markus 1981: c->remote_id = remote_id;
1.25 markus 1982: }
1.121 markus 1983: if (c == NULL) {
1984: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1985: packet_put_int(remote_id);
1986: packet_send();
1987: }
1988: xfree(host);
1.1 deraadt 1989: }
1990:
1.121 markus 1991:
1992: /* -- tcp forwarding */
1.135 markus 1993:
1994: void
1995: channel_set_af(int af)
1996: {
1997: IPv4or6 = af;
1998: }
1.121 markus 1999:
1.160 markus 2000: static int
2001: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2002: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2003: {
1.113 markus 2004: Channel *c;
1.160 markus 2005: int success, sock, on = 1;
1.35 markus 2006: struct addrinfo hints, *ai, *aitop;
1.160 markus 2007: const char *host;
1.35 markus 2008: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2009: struct linger linger;
1.25 markus 2010:
1.87 markus 2011: success = 0;
1.160 markus 2012: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2013: listen_addr : host_to_connect;
1.87 markus 2014:
1.160 markus 2015: if (host == NULL) {
2016: error("No forward host name.");
2017: return success;
1.73 markus 2018: }
1.113 markus 2019: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2020: error("Forward host name too long.");
2021: return success;
2022: }
1.25 markus 2023:
1.28 markus 2024: /*
1.35 markus 2025: * getaddrinfo returns a loopback address if the hostname is
2026: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2027: */
1.35 markus 2028: memset(&hints, 0, sizeof(hints));
2029: hints.ai_family = IPv4or6;
2030: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2031: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2032: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2033: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2034: packet_disconnect("getaddrinfo: fatal error");
2035:
2036: for (ai = aitop; ai; ai = ai->ai_next) {
2037: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2038: continue;
2039: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2040: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2041: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2042: continue;
2043: }
2044: /* Create a port to listen for the host. */
2045: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2046: if (sock < 0) {
2047: /* this is no error since kernel may not support ipv6 */
2048: verbose("socket: %.100s", strerror(errno));
2049: continue;
2050: }
2051: /*
2052: * Set socket options. We would like the socket to disappear
2053: * as soon as it has been closed for whatever reason.
2054: */
1.170 stevesk 2055: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
1.35 markus 2056: linger.l_onoff = 1;
2057: linger.l_linger = 5;
1.170 stevesk 2058: setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
1.35 markus 2059: debug("Local forwarding listening on %s port %s.", ntop, strport);
2060:
2061: /* Bind the socket to the address. */
2062: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2063: /* address can be in use ipv6 address is already bound */
2064: verbose("bind: %.100s", strerror(errno));
2065: close(sock);
2066: continue;
2067: }
2068: /* Start listening for connections on the socket. */
2069: if (listen(sock, 5) < 0) {
2070: error("listen: %.100s", strerror(errno));
2071: close(sock);
2072: continue;
2073: }
2074: /* Allocate a channel number for the socket. */
1.121 markus 2075: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2076: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2077: 0, xstrdup("port listener"), 1);
1.113 markus 2078: strlcpy(c->path, host, sizeof(c->path));
2079: c->host_port = port_to_connect;
2080: c->listening_port = listen_port;
1.35 markus 2081: success = 1;
2082: }
2083: if (success == 0)
1.160 markus 2084: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2085: listen_port);
1.35 markus 2086: freeaddrinfo(aitop);
1.87 markus 2087: return success;
1.25 markus 2088: }
1.1 deraadt 2089:
1.160 markus 2090: /* protocol local port fwd, used by ssh (and sshd in v1) */
2091: int
2092: channel_setup_local_fwd_listener(u_short listen_port,
2093: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2094: {
2095: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2096: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2097: }
2098:
2099: /* protocol v2 remote port fwd, used by sshd */
2100: int
2101: channel_setup_remote_fwd_listener(const char *listen_address,
2102: u_short listen_port, int gateway_ports)
2103: {
2104: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2105: listen_address, listen_port, NULL, 0, gateway_ports);
2106: }
2107:
1.27 markus 2108: /*
2109: * Initiate forwarding of connections to port "port" on remote host through
2110: * the secure channel to host:port from local side.
2111: */
1.1 deraadt 2112:
1.49 markus 2113: void
1.73 markus 2114: channel_request_remote_forwarding(u_short listen_port,
2115: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2116: {
1.153 markus 2117: int type, success = 0;
1.73 markus 2118:
1.25 markus 2119: /* Record locally that connection to this host/port is permitted. */
2120: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2121: fatal("channel_request_remote_forwarding: too many forwards");
2122:
2123: /* Send the forward request to the remote side. */
1.44 markus 2124: if (compat20) {
2125: const char *address_to_bind = "0.0.0.0";
2126: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2127: packet_put_cstring("tcpip-forward");
1.172.2.1 jason 2128: packet_put_char(1); /* boolean: want reply */
1.44 markus 2129: packet_put_cstring(address_to_bind);
2130: packet_put_int(listen_port);
1.73 markus 2131: packet_send();
2132: packet_write_wait();
2133: /* Assume that server accepts the request */
2134: success = 1;
1.44 markus 2135: } else {
2136: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2137: packet_put_int(listen_port);
2138: packet_put_cstring(host_to_connect);
1.44 markus 2139: packet_put_int(port_to_connect);
2140: packet_send();
2141: packet_write_wait();
1.73 markus 2142:
2143: /* Wait for response from the remote side. */
1.153 markus 2144: type = packet_read();
1.73 markus 2145: switch (type) {
2146: case SSH_SMSG_SUCCESS:
2147: success = 1;
2148: break;
2149: case SSH_SMSG_FAILURE:
2150: log("Warning: Server denied remote port forwarding.");
2151: break;
2152: default:
2153: /* Unknown packet */
2154: packet_disconnect("Protocol error for port forward request:"
2155: "received packet type %d.", type);
2156: }
2157: }
2158: if (success) {
2159: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2160: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2161: permitted_opens[num_permitted_opens].listen_port = listen_port;
2162: num_permitted_opens++;
1.44 markus 2163: }
1.1 deraadt 2164: }
2165:
1.27 markus 2166: /*
2167: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2168: * listening for the port, and sends back a success reply (or disconnect
2169: * message if there was an error). This never returns if there was an error.
2170: */
1.1 deraadt 2171:
1.49 markus 2172: void
1.56 markus 2173: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2174: {
1.31 markus 2175: u_short port, host_port;
1.25 markus 2176: char *hostname;
1.1 deraadt 2177:
1.25 markus 2178: /* Get arguments from the packet. */
2179: port = packet_get_int();
2180: hostname = packet_get_string(NULL);
2181: host_port = packet_get_int();
2182:
1.27 markus 2183: /*
2184: * Check that an unprivileged user is not trying to forward a
2185: * privileged port.
2186: */
1.25 markus 2187: if (port < IPPORT_RESERVED && !is_root)
2188: packet_disconnect("Requested forwarding of port %d but user is not root.",
2189: port);
1.73 markus 2190: /* Initiate forwarding */
1.160 markus 2191: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2192:
2193: /* Free the argument string. */
2194: xfree(hostname);
1.1 deraadt 2195: }
2196:
1.99 markus 2197: /*
2198: * Permits opening to any host/port if permitted_opens[] is empty. This is
2199: * usually called by the server, because the user could connect to any port
2200: * anyway, and the server has no way to know but to trust the client anyway.
2201: */
2202: void
1.142 itojun 2203: channel_permit_all_opens(void)
1.99 markus 2204: {
2205: if (num_permitted_opens == 0)
2206: all_opens_permitted = 1;
2207: }
2208:
1.101 markus 2209: void
1.99 markus 2210: channel_add_permitted_opens(char *host, int port)
2211: {
2212: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2213: fatal("channel_request_remote_forwarding: too many forwards");
2214: debug("allow port forwarding to host %s port %d", host, port);
2215:
2216: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2217: permitted_opens[num_permitted_opens].port_to_connect = port;
2218: num_permitted_opens++;
2219:
2220: all_opens_permitted = 0;
2221: }
2222:
1.101 markus 2223: void
1.99 markus 2224: channel_clear_permitted_opens(void)
2225: {
2226: int i;
2227:
2228: for (i = 0; i < num_permitted_opens; i++)
2229: xfree(permitted_opens[i].host_to_connect);
2230: num_permitted_opens = 0;
2231:
2232: }
2233:
2234:
2235: /* return socket to remote host, port */
1.127 itojun 2236: static int
1.99 markus 2237: connect_to(const char *host, u_short port)
1.41 markus 2238: {
2239: struct addrinfo hints, *ai, *aitop;
2240: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2241: int gaierr;
2242: int sock = -1;
2243:
2244: memset(&hints, 0, sizeof(hints));
2245: hints.ai_family = IPv4or6;
2246: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2247: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2248: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2249: error("connect_to %.100s: unknown host (%s)", host,
2250: gai_strerror(gaierr));
1.41 markus 2251: return -1;
2252: }
2253: for (ai = aitop; ai; ai = ai->ai_next) {
2254: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2255: continue;
2256: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2257: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2258: error("connect_to: getnameinfo failed");
1.41 markus 2259: continue;
2260: }
2261: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2262: if (sock < 0) {
2263: error("socket: %.100s", strerror(errno));
2264: continue;
2265: }
1.80 markus 2266: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2267: fatal("connect_to: F_SETFL: %s", strerror(errno));
2268: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2269: errno != EINPROGRESS) {
1.99 markus 2270: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2271: strerror(errno));
2272: close(sock);
1.89 stevesk 2273: continue; /* fail -- try next */
1.41 markus 2274: }
2275: break; /* success */
2276:
2277: }
2278: freeaddrinfo(aitop);
2279: if (!ai) {
1.99 markus 2280: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2281: return -1;
2282: }
2283: /* success */
1.169 stevesk 2284: set_nodelay(sock);
1.41 markus 2285: return sock;
2286: }
1.99 markus 2287:
1.73 markus 2288: int
1.130 stevesk 2289: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2290: {
2291: int i;
1.99 markus 2292:
1.73 markus 2293: for (i = 0; i < num_permitted_opens; i++)
2294: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2295: return connect_to(
1.73 markus 2296: permitted_opens[i].host_to_connect,
2297: permitted_opens[i].port_to_connect);
1.74 markus 2298: error("WARNING: Server requests forwarding for unknown listen_port %d",
2299: listen_port);
1.73 markus 2300: return -1;
2301: }
2302:
1.99 markus 2303: /* Check if connecting to that port is permitted and connect. */
2304: int
2305: channel_connect_to(const char *host, u_short port)
2306: {
2307: int i, permit;
2308:
2309: permit = all_opens_permitted;
2310: if (!permit) {
2311: for (i = 0; i < num_permitted_opens; i++)
2312: if (permitted_opens[i].port_to_connect == port &&
2313: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2314: permit = 1;
2315:
2316: }
2317: if (!permit) {
2318: log("Received request to connect to host %.100s port %d, "
2319: "but the request was denied.", host, port);
2320: return -1;
2321: }
2322: return connect_to(host, port);
2323: }
2324:
1.121 markus 2325: /* -- X11 forwarding */
1.1 deraadt 2326:
1.27 markus 2327: /*
2328: * Creates an internet domain socket for listening for X11 connections.
1.172.2.3! jason 2329: * Returns 0 and a suitable display number for the DISPLAY variable
! 2330: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2331: */
1.141 stevesk 2332: int
1.163 stevesk 2333: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.172.2.3! jason 2334: int single_connection, u_int *display_numberp)
1.1 deraadt 2335: {
1.149 markus 2336: Channel *nc = NULL;
1.31 markus 2337: int display_number, sock;
2338: u_short port;
1.35 markus 2339: struct addrinfo hints, *ai, *aitop;
2340: char strport[NI_MAXSERV];
2341: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2342:
1.33 markus 2343: for (display_number = x11_display_offset;
1.148 deraadt 2344: display_number < MAX_DISPLAYS;
2345: display_number++) {
1.25 markus 2346: port = 6000 + display_number;
1.35 markus 2347: memset(&hints, 0, sizeof(hints));
2348: hints.ai_family = IPv4or6;
1.163 stevesk 2349: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2350: hints.ai_socktype = SOCK_STREAM;
2351: snprintf(strport, sizeof strport, "%d", port);
2352: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2353: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2354: return -1;
1.25 markus 2355: }
1.35 markus 2356: for (ai = aitop; ai; ai = ai->ai_next) {
2357: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2358: continue;
2359: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2360: if (sock < 0) {
2361: error("socket: %.100s", strerror(errno));
1.141 stevesk 2362: return -1;
1.35 markus 2363: }
2364: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2365: debug("bind port %d: %.100s", port, strerror(errno));
2366: close(sock);
2367: for (n = 0; n < num_socks; n++) {
2368: close(socks[n]);
2369: }
2370: num_socks = 0;
2371: break;
2372: }
2373: socks[num_socks++] = sock;
2374: if (num_socks == NUM_SOCKS)
2375: break;
1.25 markus 2376: }
1.83 stevesk 2377: freeaddrinfo(aitop);
1.35 markus 2378: if (num_socks > 0)
2379: break;
1.25 markus 2380: }
2381: if (display_number >= MAX_DISPLAYS) {
2382: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2383: return -1;
1.25 markus 2384: }
2385: /* Start listening for connections on the socket. */
1.35 markus 2386: for (n = 0; n < num_socks; n++) {
2387: sock = socks[n];
2388: if (listen(sock, 5) < 0) {
2389: error("listen: %.100s", strerror(errno));
2390: close(sock);
1.141 stevesk 2391: return -1;
1.35 markus 2392: }
1.25 markus 2393: }
1.35 markus 2394:
2395: /* Allocate a channel for each socket. */
2396: for (n = 0; n < num_socks; n++) {
2397: sock = socks[n];
1.149 markus 2398: nc = channel_new("x11 listener",
1.51 markus 2399: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2400: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2401: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2402: nc->single_connection = single_connection;
1.35 markus 2403: }
1.1 deraadt 2404:
1.141 stevesk 2405: /* Return the display number for the DISPLAY environment variable. */
1.172.2.3! jason 2406: *display_numberp = display_number;
! 2407: return (0);
1.1 deraadt 2408: }
2409:
1.127 itojun 2410: static int
1.77 markus 2411: connect_local_xsocket(u_int dnr)
1.1 deraadt 2412: {
1.25 markus 2413: int sock;
2414: struct sockaddr_un addr;
2415:
1.147 stevesk 2416: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2417: if (sock < 0)
2418: error("socket: %.100s", strerror(errno));
2419: memset(&addr, 0, sizeof(addr));
2420: addr.sun_family = AF_UNIX;
2421: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2422: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2423: return sock;
2424: close(sock);
1.25 markus 2425: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2426: return -1;
1.1 deraadt 2427: }
2428:
1.51 markus 2429: int
2430: x11_connect_display(void)
1.1 deraadt 2431: {
1.162 stevesk 2432: int display_number, sock = 0;
1.25 markus 2433: const char *display;
1.51 markus 2434: char buf[1024], *cp;
1.35 markus 2435: struct addrinfo hints, *ai, *aitop;
2436: char strport[NI_MAXSERV];
2437: int gaierr;
1.25 markus 2438:
2439: /* Try to open a socket for the local X server. */
2440: display = getenv("DISPLAY");
2441: if (!display) {
2442: error("DISPLAY not set.");
1.51 markus 2443: return -1;
1.25 markus 2444: }
1.27 markus 2445: /*
2446: * Now we decode the value of the DISPLAY variable and make a
2447: * connection to the real X server.
2448: */
2449:
2450: /*
2451: * Check if it is a unix domain socket. Unix domain displays are in
2452: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2453: */
1.25 markus 2454: if (strncmp(display, "unix:", 5) == 0 ||
2455: display[0] == ':') {
2456: /* Connect to the unix domain socket. */
2457: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2458: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2459: display);
1.51 markus 2460: return -1;
1.25 markus 2461: }
2462: /* Create a socket. */
2463: sock = connect_local_xsocket(display_number);
2464: if (sock < 0)
1.51 markus 2465: return -1;
1.25 markus 2466:
2467: /* OK, we now have a connection to the display. */
1.51 markus 2468: return sock;
1.25 markus 2469: }
1.27 markus 2470: /*
2471: * Connect to an inet socket. The DISPLAY value is supposedly
2472: * hostname:d[.s], where hostname may also be numeric IP address.
2473: */
1.145 stevesk 2474: strlcpy(buf, display, sizeof(buf));
1.25 markus 2475: cp = strchr(buf, ':');
2476: if (!cp) {
2477: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2478: return -1;
1.25 markus 2479: }
2480: *cp = 0;
1.27 markus 2481: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2482: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2483: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2484: display);
1.51 markus 2485: return -1;
1.25 markus 2486: }
1.35 markus 2487:
2488: /* Look up the host address */
2489: memset(&hints, 0, sizeof(hints));
2490: hints.ai_family = IPv4or6;
2491: hints.ai_socktype = SOCK_STREAM;
2492: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2493: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2494: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2495: return -1;
1.25 markus 2496: }
1.35 markus 2497: for (ai = aitop; ai; ai = ai->ai_next) {
2498: /* Create a socket. */
2499: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2500: if (sock < 0) {
2501: debug("socket: %.100s", strerror(errno));
1.41 markus 2502: continue;
2503: }
2504: /* Connect it to the display. */
2505: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2506: debug("connect %.100s port %d: %.100s", buf,
2507: 6000 + display_number, strerror(errno));
2508: close(sock);
2509: continue;
2510: }
2511: /* Success */
2512: break;
1.35 markus 2513: }
2514: freeaddrinfo(aitop);
2515: if (!ai) {
1.49 markus 2516: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2517: strerror(errno));
1.51 markus 2518: return -1;
1.25 markus 2519: }
1.162 stevesk 2520: set_nodelay(sock);
1.51 markus 2521: return sock;
2522: }
2523:
2524: /*
2525: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2526: * the remote channel number. We should do whatever we want, and respond
2527: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2528: */
2529:
2530: void
1.154 markus 2531: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2532: {
1.113 markus 2533: Channel *c = NULL;
2534: int remote_id, sock = 0;
1.51 markus 2535: char *remote_host;
1.25 markus 2536:
1.113 markus 2537: debug("Received X11 open request.");
1.51 markus 2538:
1.113 markus 2539: remote_id = packet_get_int();
1.121 markus 2540:
2541: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2542: remote_host = packet_get_string(NULL);
1.51 markus 2543: } else {
2544: remote_host = xstrdup("unknown (remote did not supply name)");
2545: }
1.152 markus 2546: packet_check_eom();
1.25 markus 2547:
1.51 markus 2548: /* Obtain a connection to the real X display. */
2549: sock = x11_connect_display();
1.113 markus 2550: if (sock != -1) {
2551: /* Allocate a channel for this connection. */
2552: c = channel_new("connected x11 socket",
2553: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2554: remote_host, 1);
1.167 markus 2555: c->remote_id = remote_id;
2556: c->force_drain = 1;
1.113 markus 2557: }
2558: if (c == NULL) {
1.51 markus 2559: /* Send refusal to the remote host. */
2560: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2561: packet_put_int(remote_id);
1.51 markus 2562: } else {
2563: /* Send a confirmation to the remote host. */
2564: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2565: packet_put_int(remote_id);
2566: packet_put_int(c->self);
1.51 markus 2567: }
1.113 markus 2568: packet_send();
1.72 markus 2569: }
2570:
2571: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2572: void
1.154 markus 2573: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2574: {
2575: int rchan = packet_get_int();
1.143 deraadt 2576: switch (type) {
1.72 markus 2577: case SSH_SMSG_AGENT_OPEN:
2578: error("Warning: ssh server tried agent forwarding.");
2579: break;
2580: case SSH_SMSG_X11_OPEN:
2581: error("Warning: ssh server tried X11 forwarding.");
2582: break;
2583: default:
1.154 markus 2584: error("deny_input_open: type %d", type);
1.72 markus 2585: break;
2586: }
2587: error("Warning: this is probably a break in attempt by a malicious server.");
2588: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2589: packet_put_int(rchan);
2590: packet_send();
1.1 deraadt 2591: }
2592:
1.27 markus 2593: /*
2594: * Requests forwarding of X11 connections, generates fake authentication
2595: * data, and enables authentication spoofing.
1.121 markus 2596: * This should be called in the client only.
1.27 markus 2597: */
1.49 markus 2598: void
1.51 markus 2599: x11_request_forwarding_with_spoofing(int client_session_id,
2600: const char *proto, const char *data)
1.1 deraadt 2601: {
1.77 markus 2602: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2603: u_int i, value, len;
1.25 markus 2604: char *new_data;
2605: int screen_number;
2606: const char *cp;
2607: u_int32_t rand = 0;
2608:
2609: cp = getenv("DISPLAY");
2610: if (cp)
2611: cp = strchr(cp, ':');
2612: if (cp)
2613: cp = strchr(cp, '.');
2614: if (cp)
2615: screen_number = atoi(cp + 1);
2616: else
2617: screen_number = 0;
2618:
2619: /* Save protocol name. */
2620: x11_saved_proto = xstrdup(proto);
2621:
1.27 markus 2622: /*
2623: * Extract real authentication data and generate fake data of the
2624: * same length.
2625: */
1.25 markus 2626: x11_saved_data = xmalloc(data_len);
2627: x11_fake_data = xmalloc(data_len);
2628: for (i = 0; i < data_len; i++) {
2629: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2630: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2631: if (i % 4 == 0)
2632: rand = arc4random();
2633: x11_saved_data[i] = value;
2634: x11_fake_data[i] = rand & 0xff;
2635: rand >>= 8;
2636: }
2637: x11_saved_data_len = data_len;
2638: x11_fake_data_len = data_len;
2639:
2640: /* Convert the fake data into hex. */
1.90 markus 2641: len = 2 * data_len + 1;
2642: new_data = xmalloc(len);
1.25 markus 2643: for (i = 0; i < data_len; i++)
1.90 markus 2644: snprintf(new_data + 2 * i, len - 2 * i,
2645: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2646:
2647: /* Send the request packet. */
1.51 markus 2648: if (compat20) {
2649: channel_request_start(client_session_id, "x11-req", 0);
2650: packet_put_char(0); /* XXX bool single connection */
2651: } else {
2652: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2653: }
2654: packet_put_cstring(proto);
2655: packet_put_cstring(new_data);
1.25 markus 2656: packet_put_int(screen_number);
2657: packet_send();
2658: packet_write_wait();
2659: xfree(new_data);
1.1 deraadt 2660: }
2661:
1.121 markus 2662:
2663: /* -- agent forwarding */
2664:
1.1 deraadt 2665: /* Sends a message to the server to request authentication fd forwarding. */
2666:
1.49 markus 2667: void
1.142 itojun 2668: auth_request_forwarding(void)
1.1 deraadt 2669: {
1.25 markus 2670: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2671: packet_send();
2672: packet_write_wait();
1.1 deraadt 2673: }
2674:
2675: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2676:
1.49 markus 2677: void
1.154 markus 2678: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2679: {
1.113 markus 2680: Channel *c = NULL;
2681: int remote_id, sock;
1.121 markus 2682: char *name;
1.41 markus 2683:
1.25 markus 2684: /* Read the remote channel number from the message. */
1.113 markus 2685: remote_id = packet_get_int();
1.152 markus 2686: packet_check_eom();
1.25 markus 2687:
1.27 markus 2688: /*
2689: * Get a connection to the local authentication agent (this may again
2690: * get forwarded).
2691: */
1.25 markus 2692: sock = ssh_get_authentication_socket();
2693:
1.27 markus 2694: /*
2695: * If we could not connect the agent, send an error message back to
2696: * the server. This should never happen unless the agent dies,
2697: * because authentication forwarding is only enabled if we have an
2698: * agent.
2699: */
1.113 markus 2700: if (sock >= 0) {
1.121 markus 2701: name = xstrdup("authentication agent connection");
2702: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2703: -1, 0, 0, 0, name, 1);
1.167 markus 2704: c->remote_id = remote_id;
2705: c->force_drain = 1;
1.113 markus 2706: }
2707: if (c == NULL) {
1.25 markus 2708: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2709: packet_put_int(remote_id);
2710: } else {
2711: /* Send a confirmation to the remote host. */
2712: debug("Forwarding authentication connection.");
2713: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2714: packet_put_int(remote_id);
2715: packet_put_int(c->self);
1.25 markus 2716: }
2717: packet_send();
1.1 deraadt 2718: }
![[BACK]](/icons/back.gif){kind=icon}
Return to channels.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh