Annotation of src/usr.bin/ssh/channels.c, Revision 1.140.2.3
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.
1.140.2.1 jason 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"
1.140.2.3! miod 42: RCSID("$OpenBSD: channels.c,v 1.140.2.2 2002/05/17 00:03:23 miod Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
49: #include "uidswap.h"
1.82 markus 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.82 markus 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.140.2.1 jason 57: #include "pathnames.h"
1.44 markus 58:
1.1 deraadt 59:
1.121 markus 60: /* -- channel core */
1.12 markus 61:
1.27 markus 62: /*
63: * Pointer to an array containing all allocated channels. The array is
64: * dynamically extended as needed.
65: */
1.113 markus 66: static Channel **channels = NULL;
1.1 deraadt 67:
1.27 markus 68: /*
69: * Size of the channel array. All slots of the array must always be
1.113 markus 70: * initialized (at least the type field); unused slots set to NULL
1.27 markus 71: */
1.1 deraadt 72: static int channels_alloc = 0;
73:
1.27 markus 74: /*
75: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 76: * updated in channel_new.
1.27 markus 77: */
1.84 markus 78: static int channel_max_fd = 0;
1.1 deraadt 79:
80:
1.121 markus 81: /* -- tcp forwarding */
1.1 deraadt 82:
1.27 markus 83: /*
84: * Data structure for storing which hosts are permitted for forward requests.
85: * The local sides of any remote forwards are stored in this array to prevent
86: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
87: * network (which might be behind a firewall).
88: */
1.25 markus 89: typedef struct {
1.41 markus 90: char *host_to_connect; /* Connect to 'host'. */
91: u_short port_to_connect; /* Connect to 'port'. */
92: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 93: } ForwardPermission;
94:
95: /* List of all permitted host/port pairs to connect. */
96: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 97:
1.1 deraadt 98: /* Number of permitted host/port pairs in the array. */
99: static int num_permitted_opens = 0;
1.27 markus 100: /*
101: * If this is true, all opens are permitted. This is the case on the server
102: * on which we have to trust the client anyway, and the user could do
103: * anything after logging in anyway.
104: */
1.1 deraadt 105: static int all_opens_permitted = 0;
106:
1.121 markus 107:
108: /* -- X11 forwarding */
109:
110: /* Maximum number of fake X11 displays to try. */
111: #define MAX_DISPLAYS 1000
112:
113: /* Saved X11 authentication protocol name. */
114: static char *x11_saved_proto = NULL;
115:
116: /* Saved X11 authentication data. This is the real data. */
117: static char *x11_saved_data = NULL;
118: static u_int x11_saved_data_len = 0;
119:
120: /*
121: * Fake X11 authentication data. This is what the server will be sending us;
122: * we should replace any occurrences of this by the real data.
123: */
124: static char *x11_fake_data = NULL;
125: static u_int x11_fake_data_len;
126:
127:
128: /* -- agent forwarding */
129:
130: #define NUM_SOCKS 10
131:
1.82 markus 132: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 133: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 134:
1.121 markus 135: /* helper */
1.127 itojun 136: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 137:
1.121 markus 138: /* -- channel core */
1.41 markus 139:
140: Channel *
141: channel_lookup(int id)
142: {
143: Channel *c;
1.113 markus 144:
1.140.2.1 jason 145: if (id < 0 || id >= channels_alloc) {
1.41 markus 146: log("channel_lookup: %d: bad id", id);
147: return NULL;
148: }
1.113 markus 149: c = channels[id];
150: if (c == NULL) {
1.41 markus 151: log("channel_lookup: %d: bad id: channel free", id);
152: return NULL;
153: }
154: return c;
1.55 markus 155: }
156:
1.27 markus 157: /*
1.55 markus 158: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 159: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 160: */
1.1 deraadt 161:
1.127 itojun 162: static void
1.71 markus 163: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
164: int extusage, int nonblock)
1.1 deraadt 165: {
1.25 markus 166: /* Update the maximum file descriptor value. */
1.84 markus 167: channel_max_fd = MAX(channel_max_fd, rfd);
168: channel_max_fd = MAX(channel_max_fd, wfd);
169: channel_max_fd = MAX(channel_max_fd, efd);
170:
1.27 markus 171: /* XXX set close-on-exec -markus */
1.55 markus 172:
1.52 markus 173: c->rfd = rfd;
174: c->wfd = wfd;
175: c->sock = (rfd == wfd) ? rfd : -1;
176: c->efd = efd;
177: c->extended_usage = extusage;
1.71 markus 178:
1.91 markus 179: /* XXX ugly hack: nonblock is only set by the server */
180: if (nonblock && isatty(c->rfd)) {
1.94 markus 181: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 182: c->isatty = 1;
183: if (!isatty(c->wfd)) {
1.94 markus 184: error("channel %d: wfd %d is not a tty?",
1.91 markus 185: c->self, c->wfd);
186: }
187: } else {
188: c->isatty = 0;
189: }
190:
1.71 markus 191: /* enable nonblocking mode */
192: if (nonblock) {
193: if (rfd != -1)
194: set_nonblock(rfd);
195: if (wfd != -1)
196: set_nonblock(wfd);
197: if (efd != -1)
198: set_nonblock(efd);
199: }
1.52 markus 200: }
201:
202: /*
203: * Allocate a new channel object and set its type and socket. This will cause
204: * remote_name to be freed.
205: */
206:
1.113 markus 207: Channel *
1.52 markus 208: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 209: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 210: {
211: int i, found;
212: Channel *c;
1.25 markus 213:
214: /* Do initial allocation if this is the first call. */
215: if (channels_alloc == 0) {
216: channels_alloc = 10;
1.113 markus 217: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 218: for (i = 0; i < channels_alloc; i++)
1.113 markus 219: channels[i] = NULL;
1.126 markus 220: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 221: }
222: /* Try to find a free slot where to put the new channel. */
223: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 224: if (channels[i] == NULL) {
1.25 markus 225: /* Found a free slot. */
226: found = i;
227: break;
228: }
229: if (found == -1) {
1.27 markus 230: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 231: found = channels_alloc;
232: channels_alloc += 10;
1.70 markus 233: debug2("channel: expanding %d", channels_alloc);
1.113 markus 234: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 235: for (i = found; i < channels_alloc; i++)
1.113 markus 236: channels[i] = NULL;
1.25 markus 237: }
1.113 markus 238: /* Initialize and return new channel. */
239: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 240: memset(c, 0, sizeof(Channel));
1.25 markus 241: buffer_init(&c->input);
242: buffer_init(&c->output);
1.41 markus 243: buffer_init(&c->extended);
1.140.2.1 jason 244: c->ostate = CHAN_OUTPUT_OPEN;
245: c->istate = CHAN_INPUT_OPEN;
246: c->flags = 0;
1.71 markus 247: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 248: c->self = found;
249: c->type = type;
1.41 markus 250: c->ctype = ctype;
1.51 markus 251: c->local_window = window;
252: c->local_window_max = window;
253: c->local_consumed = 0;
254: c->local_maxpacket = maxpack;
1.25 markus 255: c->remote_id = -1;
256: c->remote_name = remote_name;
1.41 markus 257: c->remote_window = 0;
258: c->remote_maxpacket = 0;
1.133 markus 259: c->force_drain = 0;
1.140.2.1 jason 260: c->single_connection = 0;
1.131 markus 261: c->detach_user = NULL;
1.140.2.1 jason 262: c->confirm = NULL;
1.65 markus 263: c->input_filter = NULL;
1.25 markus 264: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 265: return c;
1.1 deraadt 266: }
1.52 markus 267:
1.132 markus 268: static int
269: channel_find_maxfd(void)
270: {
271: int i, max = 0;
272: Channel *c;
273:
274: for (i = 0; i < channels_alloc; i++) {
275: c = channels[i];
276: if (c != NULL) {
277: max = MAX(max, c->rfd);
278: max = MAX(max, c->wfd);
279: max = MAX(max, c->efd);
280: }
281: }
282: return max;
283: }
284:
285: int
286: channel_close_fd(int *fdp)
287: {
288: int ret = 0, fd = *fdp;
289:
290: if (fd != -1) {
291: ret = close(fd);
292: *fdp = -1;
293: if (fd == channel_max_fd)
294: channel_max_fd = channel_find_maxfd();
295: }
296: return ret;
297: }
298:
1.52 markus 299: /* Close all channel fd/socket. */
300:
1.127 itojun 301: static void
1.52 markus 302: channel_close_fds(Channel *c)
303: {
1.118 markus 304: debug3("channel_close_fds: channel %d: r %d w %d e %d",
305: c->self, c->rfd, c->wfd, c->efd);
306:
1.132 markus 307: channel_close_fd(&c->sock);
308: channel_close_fd(&c->rfd);
309: channel_close_fd(&c->wfd);
310: channel_close_fd(&c->efd);
1.121 markus 311: }
312:
313: /* Free the channel and close its fd/socket. */
314:
315: void
316: channel_free(Channel *c)
317: {
318: char *s;
319: int i, n;
320:
321: for (n = 0, i = 0; i < channels_alloc; i++)
322: if (channels[i])
323: n++;
324: debug("channel_free: channel %d: %s, nchannels %d", c->self,
325: c->remote_name ? c->remote_name : "???", n);
326:
327: s = channel_open_message();
328: debug3("channel_free: status: %s", s);
329: xfree(s);
330:
331: if (c->sock != -1)
332: shutdown(c->sock, SHUT_RDWR);
333: channel_close_fds(c);
334: buffer_free(&c->input);
335: buffer_free(&c->output);
336: buffer_free(&c->extended);
337: if (c->remote_name) {
338: xfree(c->remote_name);
339: c->remote_name = NULL;
340: }
341: channels[c->self] = NULL;
342: xfree(c);
343: }
344:
345: void
1.126 markus 346: channel_free_all(void)
1.121 markus 347: {
348: int i;
349:
1.126 markus 350: for (i = 0; i < channels_alloc; i++)
351: if (channels[i] != NULL)
352: channel_free(channels[i]);
1.131 markus 353: }
354:
1.121 markus 355: /*
356: * Closes the sockets/fds of all channels. This is used to close extra file
357: * descriptors after a fork.
358: */
359:
360: void
1.140.2.1 jason 361: channel_close_all(void)
1.121 markus 362: {
363: int i;
364:
365: for (i = 0; i < channels_alloc; i++)
366: if (channels[i] != NULL)
367: channel_close_fds(channels[i]);
368: }
369:
370: /*
1.131 markus 371: * Stop listening to channels.
372: */
373:
374: void
375: channel_stop_listening(void)
376: {
377: int i;
378: Channel *c;
379:
380: for (i = 0; i < channels_alloc; i++) {
381: c = channels[i];
382: if (c != NULL) {
383: switch (c->type) {
384: case SSH_CHANNEL_AUTH_SOCKET:
385: case SSH_CHANNEL_PORT_LISTENER:
386: case SSH_CHANNEL_RPORT_LISTENER:
387: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 388: channel_close_fd(&c->sock);
1.131 markus 389: channel_free(c);
390: break;
391: }
392: }
393: }
394: }
395:
396: /*
1.121 markus 397: * Returns true if no channel has too much buffered data, and false if one or
398: * more channel is overfull.
399: */
400:
401: int
1.140.2.1 jason 402: channel_not_very_much_buffered_data(void)
1.121 markus 403: {
404: u_int i;
405: Channel *c;
406:
407: for (i = 0; i < channels_alloc; i++) {
408: c = channels[i];
409: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 410: #if 0
411: if (!compat20 &&
412: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 413: debug("channel %d: big input buffer %d",
414: c->self, buffer_len(&c->input));
415: return 0;
416: }
1.136 markus 417: #endif
1.121 markus 418: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 419: debug("channel %d: big output buffer %d > %d",
420: c->self, buffer_len(&c->output),
421: packet_get_maxsize());
1.121 markus 422: return 0;
423: }
424: }
425: }
426: return 1;
427: }
428:
429: /* Returns true if any channel is still open. */
430:
431: int
1.140.2.1 jason 432: channel_still_open(void)
1.121 markus 433: {
434: int i;
435: Channel *c;
436:
437: for (i = 0; i < channels_alloc; i++) {
438: c = channels[i];
439: if (c == NULL)
440: continue;
441: switch (c->type) {
442: case SSH_CHANNEL_X11_LISTENER:
443: case SSH_CHANNEL_PORT_LISTENER:
444: case SSH_CHANNEL_RPORT_LISTENER:
445: case SSH_CHANNEL_CLOSED:
446: case SSH_CHANNEL_AUTH_SOCKET:
447: case SSH_CHANNEL_DYNAMIC:
448: case SSH_CHANNEL_CONNECTING:
449: case SSH_CHANNEL_ZOMBIE:
450: continue;
451: case SSH_CHANNEL_LARVAL:
452: if (!compat20)
453: fatal("cannot happen: SSH_CHANNEL_LARVAL");
454: continue;
455: case SSH_CHANNEL_OPENING:
456: case SSH_CHANNEL_OPEN:
457: case SSH_CHANNEL_X11_OPEN:
458: return 1;
459: case SSH_CHANNEL_INPUT_DRAINING:
460: case SSH_CHANNEL_OUTPUT_DRAINING:
461: if (!compat13)
462: fatal("cannot happen: OUT_DRAIN");
463: return 1;
464: default:
465: fatal("channel_still_open: bad channel type %d", c->type);
466: /* NOTREACHED */
467: }
468: }
469: return 0;
470: }
471:
472: /* Returns the id of an open channel suitable for keepaliving */
473:
474: int
1.140.2.1 jason 475: channel_find_open(void)
1.121 markus 476: {
477: int i;
478: Channel *c;
479:
480: for (i = 0; i < channels_alloc; i++) {
481: c = channels[i];
482: if (c == NULL)
483: continue;
484: switch (c->type) {
485: case SSH_CHANNEL_CLOSED:
486: case SSH_CHANNEL_DYNAMIC:
487: case SSH_CHANNEL_X11_LISTENER:
488: case SSH_CHANNEL_PORT_LISTENER:
489: case SSH_CHANNEL_RPORT_LISTENER:
490: case SSH_CHANNEL_OPENING:
491: case SSH_CHANNEL_CONNECTING:
492: case SSH_CHANNEL_ZOMBIE:
493: continue;
494: case SSH_CHANNEL_LARVAL:
495: case SSH_CHANNEL_AUTH_SOCKET:
496: case SSH_CHANNEL_OPEN:
497: case SSH_CHANNEL_X11_OPEN:
498: return i;
499: case SSH_CHANNEL_INPUT_DRAINING:
500: case SSH_CHANNEL_OUTPUT_DRAINING:
501: if (!compat13)
502: fatal("cannot happen: OUT_DRAIN");
503: return i;
504: default:
505: fatal("channel_find_open: bad channel type %d", c->type);
506: /* NOTREACHED */
507: }
508: }
509: return -1;
510: }
511:
512:
513: /*
514: * Returns a message describing the currently open forwarded connections,
515: * suitable for sending to the client. The message contains crlf pairs for
516: * newlines.
517: */
518:
519: char *
1.140.2.1 jason 520: channel_open_message(void)
1.121 markus 521: {
522: Buffer buffer;
523: Channel *c;
524: char buf[1024], *cp;
525: int i;
526:
527: buffer_init(&buffer);
528: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
529: buffer_append(&buffer, buf, strlen(buf));
530: for (i = 0; i < channels_alloc; i++) {
531: c = channels[i];
532: if (c == NULL)
533: continue;
534: switch (c->type) {
535: case SSH_CHANNEL_X11_LISTENER:
536: case SSH_CHANNEL_PORT_LISTENER:
537: case SSH_CHANNEL_RPORT_LISTENER:
538: case SSH_CHANNEL_CLOSED:
539: case SSH_CHANNEL_AUTH_SOCKET:
540: case SSH_CHANNEL_ZOMBIE:
541: continue;
542: case SSH_CHANNEL_LARVAL:
543: case SSH_CHANNEL_OPENING:
544: case SSH_CHANNEL_CONNECTING:
545: case SSH_CHANNEL_DYNAMIC:
546: case SSH_CHANNEL_OPEN:
547: case SSH_CHANNEL_X11_OPEN:
548: case SSH_CHANNEL_INPUT_DRAINING:
549: case SSH_CHANNEL_OUTPUT_DRAINING:
550: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
551: c->self, c->remote_name,
552: c->type, c->remote_id,
553: c->istate, buffer_len(&c->input),
554: c->ostate, buffer_len(&c->output),
555: c->rfd, c->wfd);
556: buffer_append(&buffer, buf, strlen(buf));
557: continue;
558: default:
559: fatal("channel_open_message: bad channel type %d", c->type);
560: /* NOTREACHED */
561: }
562: }
563: buffer_append(&buffer, "\0", 1);
564: cp = xstrdup(buffer_ptr(&buffer));
565: buffer_free(&buffer);
566: return cp;
567: }
568:
569: void
570: channel_send_open(int id)
571: {
572: Channel *c = channel_lookup(id);
573: if (c == NULL) {
574: log("channel_send_open: %d: bad id", id);
575: return;
576: }
577: debug("send channel open %d", id);
578: packet_start(SSH2_MSG_CHANNEL_OPEN);
579: packet_put_cstring(c->ctype);
580: packet_put_int(c->self);
581: packet_put_int(c->local_window);
582: packet_put_int(c->local_maxpacket);
583: packet_send();
584: }
585:
586: void
1.140.2.1 jason 587: channel_request_start(int local_id, char *service, int wantconfirm)
1.121 markus 588: {
1.140.2.1 jason 589: Channel *c = channel_lookup(local_id);
1.121 markus 590: if (c == NULL) {
1.140.2.1 jason 591: log("channel_request_start: %d: unknown channel id", local_id);
1.121 markus 592: return;
593: }
1.140.2.1 jason 594: debug("channel request %d: %s", local_id, service) ;
1.121 markus 595: packet_start(SSH2_MSG_CHANNEL_REQUEST);
596: packet_put_int(c->remote_id);
597: packet_put_cstring(service);
598: packet_put_char(wantconfirm);
599: }
600: void
1.140.2.1 jason 601: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 602: {
603: Channel *c = channel_lookup(id);
604: if (c == NULL) {
1.140.2.1 jason 605: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 606: return;
607: }
1.140.2.1 jason 608: c->confirm = fn;
1.121 markus 609: }
610: void
611: channel_register_cleanup(int id, channel_callback_fn *fn)
612: {
613: Channel *c = channel_lookup(id);
614: if (c == NULL) {
615: log("channel_register_cleanup: %d: bad id", id);
616: return;
617: }
1.131 markus 618: c->detach_user = fn;
1.121 markus 619: }
620: void
621: channel_cancel_cleanup(int id)
622: {
623: Channel *c = channel_lookup(id);
624: if (c == NULL) {
625: log("channel_cancel_cleanup: %d: bad id", id);
626: return;
1.52 markus 627: }
1.131 markus 628: c->detach_user = NULL;
1.121 markus 629: }
630: void
631: channel_register_filter(int id, channel_filter_fn *fn)
632: {
633: Channel *c = channel_lookup(id);
634: if (c == NULL) {
635: log("channel_register_filter: %d: bad id", id);
636: return;
1.52 markus 637: }
1.121 markus 638: c->input_filter = fn;
1.52 markus 639: }
640:
1.49 markus 641: void
1.121 markus 642: channel_set_fds(int id, int rfd, int wfd, int efd,
1.140.2.1 jason 643: int extusage, int nonblock, u_int window_max)
1.1 deraadt 644: {
1.121 markus 645: Channel *c = channel_lookup(id);
646: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
647: fatal("channel_activate for non-larval channel %d.", id);
648: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
649: c->type = SSH_CHANNEL_OPEN;
1.140.2.1 jason 650: c->local_window = c->local_window_max = window_max;
1.121 markus 651: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
652: packet_put_int(c->remote_id);
653: packet_put_int(c->local_window);
654: packet_send();
1.1 deraadt 655: }
656:
1.27 markus 657: /*
1.41 markus 658: * 'channel_pre*' are called just before select() to add any bits relevant to
659: * channels in the select bitmasks.
660: */
661: /*
662: * 'channel_post*': perform any appropriate operations for channels which
663: * have events pending.
1.27 markus 664: */
1.41 markus 665: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
666: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
667: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
668:
1.127 itojun 669: static void
1.41 markus 670: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
671: {
672: FD_SET(c->sock, readset);
673: }
674:
1.127 itojun 675: static void
1.75 markus 676: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
677: {
678: debug3("channel %d: waiting for connection", c->self);
679: FD_SET(c->sock, writeset);
680: }
681:
1.127 itojun 682: static void
1.41 markus 683: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
684: {
685: if (buffer_len(&c->input) < packet_get_maxsize())
686: FD_SET(c->sock, readset);
687: if (buffer_len(&c->output) > 0)
688: FD_SET(c->sock, writeset);
689: }
1.1 deraadt 690:
1.127 itojun 691: static void
1.140.2.1 jason 692: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 693: {
1.140.2.1 jason 694: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 695:
1.44 markus 696: if (c->istate == CHAN_INPUT_OPEN &&
1.140.2.1 jason 697: limit > 0 &&
698: buffer_len(&c->input) < limit)
1.44 markus 699: FD_SET(c->rfd, readset);
700: if (c->ostate == CHAN_OUTPUT_OPEN ||
701: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
702: if (buffer_len(&c->output) > 0) {
703: FD_SET(c->wfd, writeset);
704: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.140.2.2 miod 705: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.140.2.3! miod 706: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
! 707: c->self, c->efd, buffer_len(&c->extended));
1.140.2.2 miod 708: else
709: chan_obuf_empty(c);
1.44 markus 710: }
711: }
712: /** XXX check close conditions, too */
1.140.2.1 jason 713: if (compat20 && c->efd != -1) {
1.44 markus 714: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
715: buffer_len(&c->extended) > 0)
716: FD_SET(c->efd, writeset);
1.140.2.2 miod 717: else if (!(c->flags & CHAN_EOF_SENT) &&
718: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 719: buffer_len(&c->extended) < c->remote_window)
720: FD_SET(c->efd, readset);
721: }
722: }
723:
1.127 itojun 724: static void
1.41 markus 725: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
726: {
727: if (buffer_len(&c->input) == 0) {
728: packet_start(SSH_MSG_CHANNEL_CLOSE);
729: packet_put_int(c->remote_id);
730: packet_send();
731: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 732: debug("channel %d: closing after input drain.", c->self);
1.41 markus 733: }
734: }
735:
1.127 itojun 736: static void
1.41 markus 737: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
738: {
739: if (buffer_len(&c->output) == 0)
1.113 markus 740: chan_mark_dead(c);
1.49 markus 741: else
1.41 markus 742: FD_SET(c->sock, writeset);
743: }
744:
745: /*
746: * This is a special state for X11 authentication spoofing. An opened X11
747: * connection (when authentication spoofing is being done) remains in this
748: * state until the first packet has been completely read. The authentication
749: * data in that packet is then substituted by the real data if it matches the
750: * fake data, and the channel is put into normal mode.
1.51 markus 751: * XXX All this happens at the client side.
1.121 markus 752: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 753: */
1.127 itojun 754: static int
1.121 markus 755: x11_open_helper(Buffer *b)
1.1 deraadt 756: {
1.77 markus 757: u_char *ucp;
758: u_int proto_len, data_len;
1.25 markus 759:
1.41 markus 760: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 761: if (buffer_len(b) < 12)
1.41 markus 762: return 0;
763:
764: /* Parse the lengths of variable-length fields. */
1.140.2.1 jason 765: ucp = buffer_ptr(b);
1.41 markus 766: if (ucp[0] == 0x42) { /* Byte order MSB first. */
767: proto_len = 256 * ucp[6] + ucp[7];
768: data_len = 256 * ucp[8] + ucp[9];
769: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
770: proto_len = ucp[6] + 256 * ucp[7];
771: data_len = ucp[8] + 256 * ucp[9];
772: } else {
773: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.140.2.1 jason 774: ucp[0]);
1.41 markus 775: return -1;
776: }
777:
778: /* Check if the whole packet is in buffer. */
1.121 markus 779: if (buffer_len(b) <
1.41 markus 780: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
781: return 0;
782:
783: /* Check if authentication protocol matches. */
784: if (proto_len != strlen(x11_saved_proto) ||
785: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
786: debug("X11 connection uses different authentication protocol.");
787: return -1;
788: }
789: /* Check if authentication data matches our fake data. */
790: if (data_len != x11_fake_data_len ||
791: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
792: x11_fake_data, x11_fake_data_len) != 0) {
793: debug("X11 auth data does not match fake data.");
794: return -1;
795: }
796: /* Check fake data length */
797: if (x11_fake_data_len != x11_saved_data_len) {
798: error("X11 fake_data_len %d != saved_data_len %d",
799: x11_fake_data_len, x11_saved_data_len);
800: return -1;
801: }
802: /*
803: * Received authentication protocol and data match
804: * our fake data. Substitute the fake data with real
805: * data.
806: */
807: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
808: x11_saved_data, x11_saved_data_len);
809: return 1;
810: }
811:
1.127 itojun 812: static void
1.41 markus 813: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
814: {
1.121 markus 815: int ret = x11_open_helper(&c->output);
1.41 markus 816: if (ret == 1) {
817: /* Start normal processing for the channel. */
818: c->type = SSH_CHANNEL_OPEN;
1.47 markus 819: channel_pre_open_13(c, readset, writeset);
1.41 markus 820: } else if (ret == -1) {
821: /*
822: * We have received an X11 connection that has bad
823: * authentication information.
824: */
1.98 millert 825: log("X11 connection rejected because of wrong authentication.");
1.41 markus 826: buffer_clear(&c->input);
827: buffer_clear(&c->output);
1.132 markus 828: channel_close_fd(&c->sock);
1.41 markus 829: c->sock = -1;
830: c->type = SSH_CHANNEL_CLOSED;
831: packet_start(SSH_MSG_CHANNEL_CLOSE);
832: packet_put_int(c->remote_id);
833: packet_send();
834: }
835: }
1.25 markus 836:
1.127 itojun 837: static void
1.51 markus 838: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 839: {
1.121 markus 840: int ret = x11_open_helper(&c->output);
1.133 markus 841:
842: /* c->force_drain = 1; */
843:
1.41 markus 844: if (ret == 1) {
845: c->type = SSH_CHANNEL_OPEN;
1.140.2.1 jason 846: channel_pre_open(c, readset, writeset);
1.41 markus 847: } else if (ret == -1) {
1.140.2.1 jason 848: log("X11 connection rejected because of wrong authentication.");
1.41 markus 849: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.140.2.1 jason 850: chan_read_failed(c);
851: buffer_clear(&c->input);
852: chan_ibuf_empty(c);
853: buffer_clear(&c->output);
854: /* for proto v1, the peer will send an IEOF */
855: if (compat20)
856: chan_write_failed(c);
857: else
858: c->type = SSH_CHANNEL_OPEN;
1.41 markus 859: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
860: }
861: }
1.25 markus 862:
1.104 markus 863: /* try to decode a socks4 header */
1.127 itojun 864: static int
1.104 markus 865: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 866: {
867: u_char *p, *host;
1.109 markus 868: int len, have, i, found;
1.140.2.1 jason 869: char username[256];
1.103 markus 870: struct {
871: u_int8_t version;
872: u_int8_t command;
873: u_int16_t dest_port;
1.104 markus 874: struct in_addr dest_addr;
1.103 markus 875: } s4_req, s4_rsp;
876:
1.104 markus 877: debug2("channel %d: decode socks4", c->self);
1.109 markus 878:
879: have = buffer_len(&c->input);
880: len = sizeof(s4_req);
881: if (have < len)
882: return 0;
883: p = buffer_ptr(&c->input);
884: for (found = 0, i = len; i < have; i++) {
885: if (p[i] == '\0') {
886: found = 1;
887: break;
888: }
889: if (i > 1024) {
890: /* the peer is probably sending garbage */
891: debug("channel %d: decode socks4: too long",
892: c->self);
893: return -1;
894: }
895: }
896: if (!found)
897: return 0;
1.103 markus 898: buffer_get(&c->input, (char *)&s4_req.version, 1);
899: buffer_get(&c->input, (char *)&s4_req.command, 1);
900: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 901: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 902: have = buffer_len(&c->input);
1.103 markus 903: p = buffer_ptr(&c->input);
904: len = strlen(p);
1.106 markus 905: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 906: if (len > have)
1.104 markus 907: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 908: c->self, len, have);
909: strlcpy(username, p, sizeof(username));
910: buffer_consume(&c->input, len);
911: buffer_consume(&c->input, 1); /* trailing '\0' */
912:
1.104 markus 913: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 914: strlcpy(c->path, host, sizeof(c->path));
915: c->host_port = ntohs(s4_req.dest_port);
1.140.2.1 jason 916:
1.106 markus 917: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
918: c->self, host, c->host_port, s4_req.command);
1.103 markus 919:
1.104 markus 920: if (s4_req.command != 1) {
921: debug("channel %d: cannot handle: socks4 cn %d",
922: c->self, s4_req.command);
923: return -1;
1.103 markus 924: }
1.104 markus 925: s4_rsp.version = 0; /* vn: 0 for reply */
926: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 927: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 928: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 929: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 930: return 1;
931: }
932:
933: /* dynamic port forwarding */
1.127 itojun 934: static void
1.104 markus 935: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
936: {
937: u_char *p;
938: int have, ret;
1.103 markus 939:
1.104 markus 940: have = buffer_len(&c->input);
1.137 markus 941: c->delayed = 0;
1.104 markus 942: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 943: /* buffer_dump(&c->input); */
1.104 markus 944: /* check if the fixed size part of the packet is in buffer. */
945: if (have < 4) {
946: /* need more */
947: FD_SET(c->sock, readset);
948: return;
949: }
950: /* try to guess the protocol */
951: p = buffer_ptr(&c->input);
952: switch (p[0]) {
953: case 0x04:
954: ret = channel_decode_socks4(c, readset, writeset);
955: break;
956: default:
957: ret = -1;
958: break;
959: }
960: if (ret < 0) {
1.113 markus 961: chan_mark_dead(c);
1.104 markus 962: } else if (ret == 0) {
963: debug2("channel %d: pre_dynamic: need more", c->self);
964: /* need more */
965: FD_SET(c->sock, readset);
966: } else {
967: /* switch to the next state */
968: c->type = SSH_CHANNEL_OPENING;
969: port_open_helper(c, "direct-tcpip");
970: }
1.103 markus 971: }
972:
1.41 markus 973: /* This is our fake X11 server socket. */
1.127 itojun 974: static void
1.41 markus 975: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
976: {
1.113 markus 977: Channel *nc;
1.41 markus 978: struct sockaddr addr;
1.113 markus 979: int newsock;
1.41 markus 980: socklen_t addrlen;
1.85 markus 981: char buf[16384], *remote_ipaddr;
1.51 markus 982: int remote_port;
1.25 markus 983:
1.41 markus 984: if (FD_ISSET(c->sock, readset)) {
985: debug("X11 connection requested.");
986: addrlen = sizeof(addr);
987: newsock = accept(c->sock, &addr, &addrlen);
1.140.2.1 jason 988: if (c->single_connection) {
989: debug("single_connection: closing X11 listener.");
990: channel_close_fd(&c->sock);
991: chan_mark_dead(c);
992: }
1.41 markus 993: if (newsock < 0) {
994: error("accept: %.100s", strerror(errno));
995: return;
996: }
1.140.2.1 jason 997: set_nodelay(newsock);
1.85 markus 998: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 999: remote_port = get_peer_port(newsock);
1.41 markus 1000: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1001: remote_ipaddr, remote_port);
1.51 markus 1002:
1.113 markus 1003: nc = channel_new("accepted x11 socket",
1.51 markus 1004: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1005: c->local_window_max, c->local_maxpacket,
1.71 markus 1006: 0, xstrdup(buf), 1);
1.51 markus 1007: if (compat20) {
1008: packet_start(SSH2_MSG_CHANNEL_OPEN);
1009: packet_put_cstring("x11");
1.113 markus 1010: packet_put_int(nc->self);
1.140.2.1 jason 1011: packet_put_int(nc->local_window_max);
1012: packet_put_int(nc->local_maxpacket);
1.85 markus 1013: /* originator ipaddr and port */
1014: packet_put_cstring(remote_ipaddr);
1.57 markus 1015: if (datafellows & SSH_BUG_X11FWD) {
1016: debug("ssh2 x11 bug compat mode");
1017: } else {
1018: packet_put_int(remote_port);
1019: }
1.51 markus 1020: packet_send();
1021: } else {
1022: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1023: packet_put_int(nc->self);
1.121 markus 1024: if (packet_get_protocol_flags() &
1025: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1026: packet_put_cstring(buf);
1.51 markus 1027: packet_send();
1028: }
1.85 markus 1029: xfree(remote_ipaddr);
1.41 markus 1030: }
1031: }
1.25 markus 1032:
1.127 itojun 1033: static void
1.103 markus 1034: port_open_helper(Channel *c, char *rtype)
1035: {
1036: int direct;
1037: char buf[1024];
1038: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1039: u_short remote_port = get_peer_port(c->sock);
1040:
1041: direct = (strcmp(rtype, "direct-tcpip") == 0);
1042:
1043: snprintf(buf, sizeof buf,
1044: "%s: listening port %d for %.100s port %d, "
1045: "connect from %.200s port %d",
1046: rtype, c->listening_port, c->path, c->host_port,
1047: remote_ipaddr, remote_port);
1048:
1049: xfree(c->remote_name);
1050: c->remote_name = xstrdup(buf);
1051:
1052: if (compat20) {
1053: packet_start(SSH2_MSG_CHANNEL_OPEN);
1054: packet_put_cstring(rtype);
1055: packet_put_int(c->self);
1056: packet_put_int(c->local_window_max);
1057: packet_put_int(c->local_maxpacket);
1058: if (direct) {
1059: /* target host, port */
1060: packet_put_cstring(c->path);
1061: packet_put_int(c->host_port);
1062: } else {
1063: /* listen address, port */
1064: packet_put_cstring(c->path);
1065: packet_put_int(c->listening_port);
1066: }
1067: /* originator host and port */
1068: packet_put_cstring(remote_ipaddr);
1069: packet_put_int(remote_port);
1070: packet_send();
1071: } else {
1072: packet_start(SSH_MSG_PORT_OPEN);
1073: packet_put_int(c->self);
1074: packet_put_cstring(c->path);
1075: packet_put_int(c->host_port);
1.121 markus 1076: if (packet_get_protocol_flags() &
1077: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1078: packet_put_cstring(c->remote_name);
1079: packet_send();
1080: }
1081: xfree(remote_ipaddr);
1082: }
1083:
1.41 markus 1084: /*
1085: * This socket is listening for connections to a forwarded TCP/IP port.
1086: */
1.127 itojun 1087: static void
1.41 markus 1088: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1089: {
1.103 markus 1090: Channel *nc;
1.41 markus 1091: struct sockaddr addr;
1.113 markus 1092: int newsock, nextstate;
1.41 markus 1093: socklen_t addrlen;
1.103 markus 1094: char *rtype;
1.73 markus 1095:
1.41 markus 1096: if (FD_ISSET(c->sock, readset)) {
1097: debug("Connection to port %d forwarding "
1098: "to %.100s port %d requested.",
1099: c->listening_port, c->path, c->host_port);
1.103 markus 1100:
1.137 markus 1101: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1102: nextstate = SSH_CHANNEL_OPENING;
1103: rtype = "forwarded-tcpip";
1104: } else {
1105: if (c->host_port == 0) {
1106: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1107: rtype = "dynamic-tcpip";
1.137 markus 1108: } else {
1109: nextstate = SSH_CHANNEL_OPENING;
1110: rtype = "direct-tcpip";
1111: }
1112: }
1.103 markus 1113:
1.41 markus 1114: addrlen = sizeof(addr);
1115: newsock = accept(c->sock, &addr, &addrlen);
1116: if (newsock < 0) {
1117: error("accept: %.100s", strerror(errno));
1118: return;
1119: }
1.140.2.1 jason 1120: set_nodelay(newsock);
1.113 markus 1121: nc = channel_new(rtype,
1.103 markus 1122: nextstate, newsock, newsock, -1,
1.41 markus 1123: c->local_window_max, c->local_maxpacket,
1.103 markus 1124: 0, xstrdup(rtype), 1);
1125: nc->listening_port = c->listening_port;
1126: nc->host_port = c->host_port;
1127: strlcpy(nc->path, c->path, sizeof(nc->path));
1128:
1.137 markus 1129: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1130: /*
1131: * do not call the channel_post handler until
1132: * this flag has been reset by a pre-handler.
1133: * otherwise the FD_ISSET calls might overflow
1134: */
1135: nc->delayed = 1;
1136: } else {
1.103 markus 1137: port_open_helper(nc, rtype);
1.137 markus 1138: }
1.41 markus 1139: }
1140: }
1.25 markus 1141:
1.41 markus 1142: /*
1143: * This is the authentication agent socket listening for connections from
1144: * clients.
1145: */
1.127 itojun 1146: static void
1.41 markus 1147: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1148: {
1.113 markus 1149: Channel *nc;
1.121 markus 1150: char *name;
1.113 markus 1151: int newsock;
1.41 markus 1152: struct sockaddr addr;
1153: socklen_t addrlen;
1.25 markus 1154:
1.41 markus 1155: if (FD_ISSET(c->sock, readset)) {
1156: addrlen = sizeof(addr);
1157: newsock = accept(c->sock, &addr, &addrlen);
1158: if (newsock < 0) {
1159: error("accept from auth socket: %.100s", strerror(errno));
1160: return;
1161: }
1.121 markus 1162: name = xstrdup("accepted auth socket");
1.113 markus 1163: nc = channel_new("accepted auth socket",
1.73 markus 1164: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1165: c->local_window_max, c->local_maxpacket,
1.121 markus 1166: 0, name, 1);
1.73 markus 1167: if (compat20) {
1168: packet_start(SSH2_MSG_CHANNEL_OPEN);
1169: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1170: packet_put_int(nc->self);
1.73 markus 1171: packet_put_int(c->local_window_max);
1172: packet_put_int(c->local_maxpacket);
1173: } else {
1174: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1175: packet_put_int(nc->self);
1.73 markus 1176: }
1.41 markus 1177: packet_send();
1178: }
1179: }
1.25 markus 1180:
1.127 itojun 1181: static void
1.75 markus 1182: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1183: {
1.114 markus 1184: int err = 0;
1.129 stevesk 1185: socklen_t sz = sizeof(err);
1.114 markus 1186:
1.75 markus 1187: if (FD_ISSET(c->sock, writeset)) {
1.140.2.1 jason 1188: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1189: err = errno;
1190: error("getsockopt SO_ERROR failed");
1191: }
1192: if (err == 0) {
1193: debug("channel %d: connected", c->self);
1194: c->type = SSH_CHANNEL_OPEN;
1195: if (compat20) {
1196: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1197: packet_put_int(c->remote_id);
1198: packet_put_int(c->self);
1199: packet_put_int(c->local_window);
1200: packet_put_int(c->local_maxpacket);
1201: } else {
1202: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1203: packet_put_int(c->remote_id);
1204: packet_put_int(c->self);
1205: }
1.75 markus 1206: } else {
1.114 markus 1207: debug("channel %d: not connected: %s",
1208: c->self, strerror(err));
1209: if (compat20) {
1210: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1211: packet_put_int(c->remote_id);
1212: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1213: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1214: packet_put_cstring(strerror(err));
1215: packet_put_cstring("");
1216: }
1.75 markus 1217: } else {
1.114 markus 1218: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1219: packet_put_int(c->remote_id);
1.75 markus 1220: }
1.114 markus 1221: chan_mark_dead(c);
1.75 markus 1222: }
1.114 markus 1223: packet_send();
1.75 markus 1224: }
1225: }
1226:
1.127 itojun 1227: static int
1.41 markus 1228: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1229: {
1230: char buf[16*1024];
1231: int len;
1.25 markus 1232:
1.118 markus 1233: if (c->rfd != -1 &&
1.41 markus 1234: FD_ISSET(c->rfd, readset)) {
1235: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1236: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1237: return 1;
1.41 markus 1238: if (len <= 0) {
1.51 markus 1239: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1240: c->self, c->rfd, len);
1.104 markus 1241: if (c->type != SSH_CHANNEL_OPEN) {
1242: debug("channel %d: not open", c->self);
1.113 markus 1243: chan_mark_dead(c);
1.103 markus 1244: return -1;
1.104 markus 1245: } else if (compat13) {
1.140.2.1 jason 1246: buffer_clear(&c->output);
1.41 markus 1247: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1248: debug("channel %d: input draining.", c->self);
1.25 markus 1249: } else {
1.41 markus 1250: chan_read_failed(c);
1.25 markus 1251: }
1.41 markus 1252: return -1;
1253: }
1.140.2.1 jason 1254: if (c->input_filter != NULL) {
1.66 markus 1255: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1256: debug("channel %d: filter stops", c->self);
1.65 markus 1257: chan_read_failed(c);
1258: }
1259: } else {
1260: buffer_append(&c->input, buf, len);
1261: }
1.41 markus 1262: }
1263: return 1;
1264: }
1.127 itojun 1265: static int
1.41 markus 1266: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1267: {
1.95 markus 1268: struct termios tio;
1.134 markus 1269: u_char *data;
1270: u_int dlen;
1.41 markus 1271: int len;
1.25 markus 1272:
1.41 markus 1273: /* Send buffered output data to the socket. */
1.118 markus 1274: if (c->wfd != -1 &&
1.41 markus 1275: FD_ISSET(c->wfd, writeset) &&
1276: buffer_len(&c->output) > 0) {
1.134 markus 1277: data = buffer_ptr(&c->output);
1278: dlen = buffer_len(&c->output);
1279: len = write(c->wfd, data, dlen);
1.53 markus 1280: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1281: return 1;
1.41 markus 1282: if (len <= 0) {
1.104 markus 1283: if (c->type != SSH_CHANNEL_OPEN) {
1284: debug("channel %d: not open", c->self);
1.113 markus 1285: chan_mark_dead(c);
1.104 markus 1286: return -1;
1287: } else if (compat13) {
1.140.2.1 jason 1288: buffer_clear(&c->output);
1.121 markus 1289: debug("channel %d: input draining.", c->self);
1.41 markus 1290: c->type = SSH_CHANNEL_INPUT_DRAINING;
1291: } else {
1292: chan_write_failed(c);
1293: }
1294: return -1;
1.91 markus 1295: }
1.134 markus 1296: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1297: if (tcgetattr(c->wfd, &tio) == 0 &&
1298: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1299: /*
1300: * Simulate echo to reduce the impact of
1.96 markus 1301: * traffic analysis. We need to match the
1.95 markus 1302: * size of a SSH2_MSG_CHANNEL_DATA message
1303: * (4 byte channel id + data)
1.91 markus 1304: */
1.95 markus 1305: packet_send_ignore(4 + len);
1.91 markus 1306: packet_send();
1307: }
1.25 markus 1308: }
1.41 markus 1309: buffer_consume(&c->output, len);
1.44 markus 1310: if (compat20 && len > 0) {
1311: c->local_consumed += len;
1312: }
1313: }
1314: return 1;
1315: }
1.127 itojun 1316: static int
1.44 markus 1317: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1318: {
1319: char buf[16*1024];
1320: int len;
1321:
1.45 markus 1322: /** XXX handle drain efd, too */
1.44 markus 1323: if (c->efd != -1) {
1324: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1325: FD_ISSET(c->efd, writeset) &&
1326: buffer_len(&c->extended) > 0) {
1327: len = write(c->efd, buffer_ptr(&c->extended),
1328: buffer_len(&c->extended));
1.70 markus 1329: debug2("channel %d: written %d to efd %d",
1.44 markus 1330: c->self, len, c->efd);
1.93 markus 1331: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1332: return 1;
1333: if (len <= 0) {
1334: debug2("channel %d: closing write-efd %d",
1335: c->self, c->efd);
1.132 markus 1336: channel_close_fd(&c->efd);
1.93 markus 1337: } else {
1.44 markus 1338: buffer_consume(&c->extended, len);
1339: c->local_consumed += len;
1340: }
1341: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1342: FD_ISSET(c->efd, readset)) {
1343: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1344: debug2("channel %d: read %d from efd %d",
1.140.2.1 jason 1345: c->self, len, c->efd);
1.93 markus 1346: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1347: return 1;
1348: if (len <= 0) {
1349: debug2("channel %d: closing read-efd %d",
1.45 markus 1350: c->self, c->efd);
1.132 markus 1351: channel_close_fd(&c->efd);
1.93 markus 1352: } else {
1.44 markus 1353: buffer_append(&c->extended, buf, len);
1.93 markus 1354: }
1.44 markus 1355: }
1356: }
1357: return 1;
1358: }
1.127 itojun 1359: static int
1.93 markus 1360: channel_check_window(Channel *c)
1.44 markus 1361: {
1.104 markus 1362: if (c->type == SSH_CHANNEL_OPEN &&
1363: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1364: c->local_window < c->local_window_max/2 &&
1365: c->local_consumed > 0) {
1366: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1367: packet_put_int(c->remote_id);
1368: packet_put_int(c->local_consumed);
1369: packet_send();
1.70 markus 1370: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1371: c->self, c->local_window,
1372: c->local_consumed);
1373: c->local_window += c->local_consumed;
1374: c->local_consumed = 0;
1.1 deraadt 1375: }
1.41 markus 1376: return 1;
1.1 deraadt 1377: }
1378:
1.127 itojun 1379: static void
1.140.2.1 jason 1380: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1381: {
1.137 markus 1382: if (c->delayed)
1383: return;
1.41 markus 1384: channel_handle_rfd(c, readset, writeset);
1385: channel_handle_wfd(c, readset, writeset);
1.140.2.1 jason 1386: if (!compat20)
1.137 markus 1387: return;
1.44 markus 1388: channel_handle_efd(c, readset, writeset);
1.93 markus 1389: channel_check_window(c);
1.44 markus 1390: }
1391:
1.127 itojun 1392: static void
1.41 markus 1393: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1394: {
1.41 markus 1395: int len;
1396: /* Send buffered output data to the socket. */
1397: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1398: len = write(c->sock, buffer_ptr(&c->output),
1399: buffer_len(&c->output));
1400: if (len <= 0)
1.140.2.1 jason 1401: buffer_clear(&c->output);
1.41 markus 1402: else
1403: buffer_consume(&c->output, len);
1404: }
1405: }
1.25 markus 1406:
1.127 itojun 1407: static void
1.44 markus 1408: channel_handler_init_20(void)
1409: {
1.140.2.1 jason 1410: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1411: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1412: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1413: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1414: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1415: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1416: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1417: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1418:
1.140.2.1 jason 1419: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1420: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1421: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1422: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1423: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1424: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.140.2.1 jason 1425: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1426: }
1427:
1.127 itojun 1428: static void
1.41 markus 1429: channel_handler_init_13(void)
1430: {
1431: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1432: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1433: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1434: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1435: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1436: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1437: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1438: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1439: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1440:
1.140.2.1 jason 1441: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1442: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1443: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1444: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1445: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1446: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.140.2.1 jason 1447: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1448: }
1.25 markus 1449:
1.127 itojun 1450: static void
1.41 markus 1451: channel_handler_init_15(void)
1452: {
1.140.2.1 jason 1453: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1454: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1455: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1456: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1457: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1458: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1459: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1460:
1.41 markus 1461: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1462: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1463: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.140.2.1 jason 1464: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1465: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.140.2.1 jason 1466: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1467: }
1.27 markus 1468:
1.127 itojun 1469: static void
1.41 markus 1470: channel_handler_init(void)
1471: {
1472: int i;
1.140.2.1 jason 1473: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1474: channel_pre[i] = NULL;
1475: channel_post[i] = NULL;
1476: }
1.44 markus 1477: if (compat20)
1478: channel_handler_init_20();
1479: else if (compat13)
1.41 markus 1480: channel_handler_init_13();
1481: else
1482: channel_handler_init_15();
1483: }
1.25 markus 1484:
1.140 markus 1485: /* gc dead channels */
1486: static void
1487: channel_garbage_collect(Channel *c)
1488: {
1489: if (c == NULL)
1490: return;
1491: if (c->detach_user != NULL) {
1492: if (!chan_is_dead(c, 0))
1493: return;
1494: debug("channel %d: gc: notify user", c->self);
1495: c->detach_user(c->self, NULL);
1496: /* if we still have a callback */
1497: if (c->detach_user != NULL)
1498: return;
1499: debug("channel %d: gc: user detached", c->self);
1500: }
1501: if (!chan_is_dead(c, 1))
1502: return;
1503: debug("channel %d: garbage collecting", c->self);
1504: channel_free(c);
1505: }
1506:
1.127 itojun 1507: static void
1.41 markus 1508: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1509: {
1510: static int did_init = 0;
1511: int i;
1512: Channel *c;
1.25 markus 1513:
1.41 markus 1514: if (!did_init) {
1515: channel_handler_init();
1516: did_init = 1;
1517: }
1518: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1519: c = channels[i];
1520: if (c == NULL)
1.41 markus 1521: continue;
1.118 markus 1522: if (ftab[c->type] != NULL)
1523: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1524: channel_garbage_collect(c);
1.1 deraadt 1525: }
1526: }
1527:
1.121 markus 1528: /*
1529: * Allocate/update select bitmasks and add any bits relevant to channels in
1530: * select bitmasks.
1531: */
1.49 markus 1532: void
1.100 markus 1533: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1534: int *nallocp, int rekeying)
1.41 markus 1535: {
1.84 markus 1536: int n;
1537: u_int sz;
1538:
1539: n = MAX(*maxfdp, channel_max_fd);
1540:
1541: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1542: /* perhaps check sz < nalloc/2 and shrink? */
1543: if (*readsetp == NULL || sz > *nallocp) {
1544: *readsetp = xrealloc(*readsetp, sz);
1545: *writesetp = xrealloc(*writesetp, sz);
1546: *nallocp = sz;
1.84 markus 1547: }
1.132 markus 1548: *maxfdp = n;
1.84 markus 1549: memset(*readsetp, 0, sz);
1550: memset(*writesetp, 0, sz);
1551:
1.100 markus 1552: if (!rekeying)
1553: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1554: }
1555:
1.121 markus 1556: /*
1557: * After select, perform any appropriate operations for channels which have
1558: * events pending.
1559: */
1.49 markus 1560: void
1.41 markus 1561: channel_after_select(fd_set * readset, fd_set * writeset)
1562: {
1563: channel_handler(channel_post, readset, writeset);
1564: }
1565:
1.121 markus 1566:
1.84 markus 1567: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1568:
1.49 markus 1569: void
1.140.2.1 jason 1570: channel_output_poll(void)
1.1 deraadt 1571: {
1.25 markus 1572: int len, i;
1.41 markus 1573: Channel *c;
1.1 deraadt 1574:
1.25 markus 1575: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1576: c = channels[i];
1577: if (c == NULL)
1578: continue;
1.37 markus 1579:
1.121 markus 1580: /*
1581: * We are only interested in channels that can have buffered
1582: * incoming data.
1583: */
1.37 markus 1584: if (compat13) {
1.41 markus 1585: if (c->type != SSH_CHANNEL_OPEN &&
1586: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1587: continue;
1588: } else {
1.41 markus 1589: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1590: continue;
1591: }
1.46 markus 1592: if (compat20 &&
1593: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1594: /* XXX is this true? */
1.140 markus 1595: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1596: continue;
1597: }
1.25 markus 1598:
1599: /* Get the amount of buffered data for this channel. */
1.93 markus 1600: if ((c->istate == CHAN_INPUT_OPEN ||
1601: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1602: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1603: /*
1604: * Send some data for the other side over the secure
1605: * connection.
1606: */
1.44 markus 1607: if (compat20) {
1608: if (len > c->remote_window)
1609: len = c->remote_window;
1610: if (len > c->remote_maxpacket)
1611: len = c->remote_maxpacket;
1.25 markus 1612: } else {
1.44 markus 1613: if (packet_is_interactive()) {
1614: if (len > 1024)
1615: len = 512;
1616: } else {
1617: /* Keep the packets at reasonable size. */
1618: if (len > packet_get_maxsize()/2)
1619: len = packet_get_maxsize()/2;
1620: }
1.25 markus 1621: }
1.41 markus 1622: if (len > 0) {
1.44 markus 1623: packet_start(compat20 ?
1624: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1625: packet_put_int(c->remote_id);
1626: packet_put_string(buffer_ptr(&c->input), len);
1627: packet_send();
1628: buffer_consume(&c->input, len);
1629: c->remote_window -= len;
1630: }
1631: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1632: if (compat13)
1633: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1634: /*
1635: * input-buffer is empty and read-socket shutdown:
1.140.2.2 miod 1636: * tell peer, that we will not send more data: send IEOF.
1637: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1638: */
1.140.2.2 miod 1639: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.140.2.3! miod 1640: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
! 1641: c->self, c->efd, buffer_len(&c->extended));
1.140.2.2 miod 1642: else
1643: chan_ibuf_empty(c);
1.25 markus 1644: }
1.44 markus 1645: /* Send extended data, i.e. stderr */
1646: if (compat20 &&
1.140.2.2 miod 1647: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1648: c->remote_window > 0 &&
1649: (len = buffer_len(&c->extended)) > 0 &&
1650: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1651: debug2("channel %d: rwin %d elen %d euse %d",
1652: c->self, c->remote_window, buffer_len(&c->extended),
1653: c->extended_usage);
1.44 markus 1654: if (len > c->remote_window)
1655: len = c->remote_window;
1656: if (len > c->remote_maxpacket)
1657: len = c->remote_maxpacket;
1658: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1659: packet_put_int(c->remote_id);
1660: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1661: packet_put_string(buffer_ptr(&c->extended), len);
1662: packet_send();
1663: buffer_consume(&c->extended, len);
1664: c->remote_window -= len;
1.93 markus 1665: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1666: }
1.25 markus 1667: }
1.1 deraadt 1668: }
1669:
1.121 markus 1670:
1671: /* -- protocol input */
1.1 deraadt 1672:
1.49 markus 1673: void
1.140.2.1 jason 1674: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1675: {
1.37 markus 1676: int id;
1.25 markus 1677: char *data;
1.77 markus 1678: u_int data_len;
1.41 markus 1679: Channel *c;
1.25 markus 1680:
1681: /* Get the channel number and verify it. */
1.37 markus 1682: id = packet_get_int();
1.41 markus 1683: c = channel_lookup(id);
1684: if (c == NULL)
1.37 markus 1685: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1686:
1687: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1688: if (c->type != SSH_CHANNEL_OPEN &&
1689: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1690: return;
1691:
1692: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1693: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1694: return;
1695:
1696: /* Get the data. */
1697: data = packet_get_string(&data_len);
1.41 markus 1698:
1.140.2.1 jason 1699: if (compat20) {
1.44 markus 1700: if (data_len > c->local_maxpacket) {
1701: log("channel %d: rcvd big packet %d, maxpack %d",
1702: c->self, data_len, c->local_maxpacket);
1703: }
1704: if (data_len > c->local_window) {
1705: log("channel %d: rcvd too much data %d, win %d",
1706: c->self, data_len, c->local_window);
1707: xfree(data);
1708: return;
1709: }
1710: c->local_window -= data_len;
1711: }
1.140.2.1 jason 1712: packet_check_eom();
1.41 markus 1713: buffer_append(&c->output, data, data_len);
1.25 markus 1714: xfree(data);
1.1 deraadt 1715: }
1.121 markus 1716:
1.49 markus 1717: void
1.140.2.1 jason 1718: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1719: {
1720: int id;
1721: int tcode;
1722: char *data;
1.77 markus 1723: u_int data_len;
1.44 markus 1724: Channel *c;
1725:
1726: /* Get the channel number and verify it. */
1727: id = packet_get_int();
1728: c = channel_lookup(id);
1729:
1730: if (c == NULL)
1731: packet_disconnect("Received extended_data for bad channel %d.", id);
1732: if (c->type != SSH_CHANNEL_OPEN) {
1733: log("channel %d: ext data for non open", id);
1734: return;
1735: }
1.140.2.2 miod 1736: if (c->flags & CHAN_EOF_RCVD) {
1737: if (datafellows & SSH_BUG_EXTEOF)
1738: debug("channel %d: accepting ext data after eof", id);
1739: else
1740: packet_disconnect("Received extended_data after EOF "
1741: "on channel %d.", id);
1742: }
1.44 markus 1743: tcode = packet_get_int();
1744: if (c->efd == -1 ||
1745: c->extended_usage != CHAN_EXTENDED_WRITE ||
1746: tcode != SSH2_EXTENDED_DATA_STDERR) {
1747: log("channel %d: bad ext data", c->self);
1748: return;
1749: }
1750: data = packet_get_string(&data_len);
1.140.2.1 jason 1751: packet_check_eom();
1.44 markus 1752: if (data_len > c->local_window) {
1753: log("channel %d: rcvd too much extended_data %d, win %d",
1754: c->self, data_len, c->local_window);
1755: xfree(data);
1756: return;
1757: }
1.70 markus 1758: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1759: c->local_window -= data_len;
1760: buffer_append(&c->extended, data, data_len);
1761: xfree(data);
1762: }
1763:
1.49 markus 1764: void
1.140.2.1 jason 1765: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1766: {
1767: int id;
1768: Channel *c;
1769:
1770: id = packet_get_int();
1.140.2.1 jason 1771: packet_check_eom();
1.41 markus 1772: c = channel_lookup(id);
1773: if (c == NULL)
1774: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1775: chan_rcvd_ieof(c);
1.133 markus 1776:
1777: /* XXX force input close */
1.140.2.1 jason 1778: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1779: debug("channel %d: FORCE input drain", c->self);
1780: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.140.2.1 jason 1781: if (buffer_len(&c->input) == 0)
1782: chan_ibuf_empty(c);
1.133 markus 1783: }
1784:
1.41 markus 1785: }
1.1 deraadt 1786:
1.49 markus 1787: void
1.140.2.1 jason 1788: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1789: {
1.41 markus 1790: int id;
1791: Channel *c;
1.1 deraadt 1792:
1.41 markus 1793: id = packet_get_int();
1.140.2.1 jason 1794: packet_check_eom();
1.41 markus 1795: c = channel_lookup(id);
1796: if (c == NULL)
1797: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1798:
1799: /*
1800: * Send a confirmation that we have closed the channel and no more
1801: * data is coming for it.
1802: */
1.25 markus 1803: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1804: packet_put_int(c->remote_id);
1.25 markus 1805: packet_send();
1806:
1.27 markus 1807: /*
1808: * If the channel is in closed state, we have sent a close request,
1809: * and the other side will eventually respond with a confirmation.
1810: * Thus, we cannot free the channel here, because then there would be
1811: * no-one to receive the confirmation. The channel gets freed when
1812: * the confirmation arrives.
1813: */
1.41 markus 1814: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1815: /*
1816: * Not a closed channel - mark it as draining, which will
1817: * cause it to be freed later.
1818: */
1.140.2.1 jason 1819: buffer_clear(&c->input);
1.41 markus 1820: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1821: }
1.1 deraadt 1822: }
1823:
1.41 markus 1824: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1825: void
1.140.2.1 jason 1826: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1827: {
1828: int id = packet_get_int();
1829: Channel *c = channel_lookup(id);
1.140.2.1 jason 1830:
1831: packet_check_eom();
1.41 markus 1832: if (c == NULL)
1833: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1834: chan_rcvd_oclose(c);
1835: }
1.1 deraadt 1836:
1.49 markus 1837: void
1.140.2.1 jason 1838: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1839: {
1.41 markus 1840: int id = packet_get_int();
1841: Channel *c = channel_lookup(id);
1.1 deraadt 1842:
1.140.2.1 jason 1843: packet_check_eom();
1.41 markus 1844: if (c == NULL)
1845: packet_disconnect("Received close confirmation for "
1846: "out-of-range channel %d.", id);
1847: if (c->type != SSH_CHANNEL_CLOSED)
1848: packet_disconnect("Received close confirmation for "
1849: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1850: channel_free(c);
1.1 deraadt 1851: }
1852:
1.49 markus 1853: void
1.140.2.1 jason 1854: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1855: {
1.41 markus 1856: int id, remote_id;
1857: Channel *c;
1.1 deraadt 1858:
1.41 markus 1859: id = packet_get_int();
1860: c = channel_lookup(id);
1.25 markus 1861:
1.41 markus 1862: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1863: packet_disconnect("Received open confirmation for "
1864: "non-opening channel %d.", id);
1865: remote_id = packet_get_int();
1.27 markus 1866: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1867: c->remote_id = remote_id;
1868: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1869:
1870: if (compat20) {
1871: c->remote_window = packet_get_int();
1872: c->remote_maxpacket = packet_get_int();
1.140.2.1 jason 1873: if (c->confirm) {
1.70 markus 1874: debug2("callback start");
1.140.2.1 jason 1875: c->confirm(c->self, NULL);
1.70 markus 1876: debug2("callback done");
1.44 markus 1877: }
1878: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1879: c->remote_window, c->remote_maxpacket);
1880: }
1.140.2.1 jason 1881: packet_check_eom();
1.1 deraadt 1882: }
1883:
1.127 itojun 1884: static char *
1.114 markus 1885: reason2txt(int reason)
1886: {
1.140.2.1 jason 1887: switch (reason) {
1.114 markus 1888: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1889: return "administratively prohibited";
1890: case SSH2_OPEN_CONNECT_FAILED:
1891: return "connect failed";
1892: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1893: return "unknown channel type";
1894: case SSH2_OPEN_RESOURCE_SHORTAGE:
1895: return "resource shortage";
1896: }
1.117 stevesk 1897: return "unknown reason";
1.114 markus 1898: }
1899:
1.49 markus 1900: void
1.140.2.1 jason 1901: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1902: {
1.86 markus 1903: int id, reason;
1904: char *msg = NULL, *lang = NULL;
1.41 markus 1905: Channel *c;
1906:
1907: id = packet_get_int();
1908: c = channel_lookup(id);
1.25 markus 1909:
1.41 markus 1910: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1911: packet_disconnect("Received open failure for "
1912: "non-opening channel %d.", id);
1.44 markus 1913: if (compat20) {
1.86 markus 1914: reason = packet_get_int();
1.110 markus 1915: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1916: msg = packet_get_string(NULL);
1917: lang = packet_get_string(NULL);
1918: }
1.114 markus 1919: log("channel %d: open failed: %s%s%s", id,
1920: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1921: if (msg != NULL)
1922: xfree(msg);
1923: if (lang != NULL)
1924: xfree(lang);
1.44 markus 1925: }
1.140.2.1 jason 1926: packet_check_eom();
1.25 markus 1927: /* Free the channel. This will also close the socket. */
1.113 markus 1928: channel_free(c);
1.1 deraadt 1929: }
1930:
1.44 markus 1931: void
1.140.2.1 jason 1932: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1933: {
1934: Channel *c;
1935: int id, adjust;
1936:
1937: if (!compat20)
1938: return;
1939:
1940: /* Get the channel number and verify it. */
1941: id = packet_get_int();
1942: c = channel_lookup(id);
1.1 deraadt 1943:
1.121 markus 1944: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1945: log("Received window adjust for "
1946: "non-open channel %d.", id);
1947: return;
1948: }
1949: adjust = packet_get_int();
1.140.2.1 jason 1950: packet_check_eom();
1.121 markus 1951: debug2("channel %d: rcvd adjust %d", id, adjust);
1952: c->remote_window += adjust;
1953: }
1.1 deraadt 1954:
1.121 markus 1955: void
1.140.2.1 jason 1956: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1957: {
1.121 markus 1958: Channel *c = NULL;
1959: u_short host_port;
1960: char *host, *originator_string;
1961: int remote_id, sock = -1;
1962:
1963: remote_id = packet_get_int();
1964: host = packet_get_string(NULL);
1965: host_port = packet_get_int();
1.25 markus 1966:
1.121 markus 1967: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1968: originator_string = packet_get_string(NULL);
1969: } else {
1970: originator_string = xstrdup("unknown (remote did not supply name)");
1971: }
1.140.2.1 jason 1972: packet_check_eom();
1.121 markus 1973: sock = channel_connect_to(host, host_port);
1974: if (sock != -1) {
1975: c = channel_new("connected socket",
1976: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1977: originator_string, 1);
1.140.2.1 jason 1978: c->remote_id = remote_id;
1.25 markus 1979: }
1.121 markus 1980: if (c == NULL) {
1981: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1982: packet_put_int(remote_id);
1983: packet_send();
1984: }
1985: xfree(host);
1.1 deraadt 1986: }
1987:
1.121 markus 1988:
1989: /* -- tcp forwarding */
1.135 markus 1990:
1991: void
1992: channel_set_af(int af)
1993: {
1994: IPv4or6 = af;
1995: }
1.121 markus 1996:
1.140.2.1 jason 1997: static int
1998: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
1999: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2000: {
1.113 markus 2001: Channel *c;
1.140.2.1 jason 2002: int success, sock, on = 1;
1.35 markus 2003: struct addrinfo hints, *ai, *aitop;
1.73 markus 2004: const char *host;
1.140.2.1 jason 2005: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2006: struct linger linger;
1.25 markus 2007:
1.87 markus 2008: success = 0;
1.140.2.1 jason 2009: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2010: listen_addr : host_to_connect;
1.87 markus 2011:
1.140.2.1 jason 2012: if (host == NULL) {
2013: error("No forward host name.");
2014: return success;
1.73 markus 2015: }
1.113 markus 2016: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2017: error("Forward host name too long.");
2018: return success;
2019: }
1.25 markus 2020:
1.28 markus 2021: /*
1.35 markus 2022: * getaddrinfo returns a loopback address if the hostname is
2023: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2024: */
1.35 markus 2025: memset(&hints, 0, sizeof(hints));
2026: hints.ai_family = IPv4or6;
2027: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2028: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2029: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2030: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2031: packet_disconnect("getaddrinfo: fatal error");
2032:
2033: for (ai = aitop; ai; ai = ai->ai_next) {
2034: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2035: continue;
2036: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2037: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.140.2.1 jason 2038: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2039: continue;
2040: }
2041: /* Create a port to listen for the host. */
2042: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2043: if (sock < 0) {
2044: /* this is no error since kernel may not support ipv6 */
2045: verbose("socket: %.100s", strerror(errno));
2046: continue;
2047: }
2048: /*
2049: * Set socket options. We would like the socket to disappear
2050: * as soon as it has been closed for whatever reason.
2051: */
1.140.2.1 jason 2052: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
1.35 markus 2053: linger.l_onoff = 1;
2054: linger.l_linger = 5;
1.140.2.1 jason 2055: setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
1.35 markus 2056: debug("Local forwarding listening on %s port %s.", ntop, strport);
2057:
2058: /* Bind the socket to the address. */
2059: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2060: /* address can be in use ipv6 address is already bound */
2061: verbose("bind: %.100s", strerror(errno));
2062: close(sock);
2063: continue;
2064: }
2065: /* Start listening for connections on the socket. */
2066: if (listen(sock, 5) < 0) {
2067: error("listen: %.100s", strerror(errno));
2068: close(sock);
2069: continue;
2070: }
2071: /* Allocate a channel number for the socket. */
1.121 markus 2072: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2073: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2074: 0, xstrdup("port listener"), 1);
1.113 markus 2075: strlcpy(c->path, host, sizeof(c->path));
2076: c->host_port = port_to_connect;
2077: c->listening_port = listen_port;
1.35 markus 2078: success = 1;
2079: }
2080: if (success == 0)
1.140.2.1 jason 2081: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2082: listen_port);
1.35 markus 2083: freeaddrinfo(aitop);
1.87 markus 2084: return success;
1.25 markus 2085: }
1.1 deraadt 2086:
1.140.2.1 jason 2087: /* protocol local port fwd, used by ssh (and sshd in v1) */
2088: int
2089: channel_setup_local_fwd_listener(u_short listen_port,
2090: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2091: {
2092: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2093: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2094: }
2095:
2096: /* protocol v2 remote port fwd, used by sshd */
2097: int
2098: channel_setup_remote_fwd_listener(const char *listen_address,
2099: u_short listen_port, int gateway_ports)
2100: {
2101: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2102: listen_address, listen_port, NULL, 0, gateway_ports);
2103: }
2104:
1.27 markus 2105: /*
2106: * Initiate forwarding of connections to port "port" on remote host through
2107: * the secure channel to host:port from local side.
2108: */
1.1 deraadt 2109:
1.49 markus 2110: void
1.73 markus 2111: channel_request_remote_forwarding(u_short listen_port,
2112: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2113: {
1.140.2.1 jason 2114: int type, success = 0;
1.73 markus 2115:
1.25 markus 2116: /* Record locally that connection to this host/port is permitted. */
2117: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2118: fatal("channel_request_remote_forwarding: too many forwards");
2119:
2120: /* Send the forward request to the remote side. */
1.44 markus 2121: if (compat20) {
2122: const char *address_to_bind = "0.0.0.0";
2123: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2124: packet_put_cstring("tcpip-forward");
1.140.2.2 miod 2125: packet_put_char(1); /* boolean: want reply */
1.44 markus 2126: packet_put_cstring(address_to_bind);
2127: packet_put_int(listen_port);
1.73 markus 2128: packet_send();
2129: packet_write_wait();
2130: /* Assume that server accepts the request */
2131: success = 1;
1.44 markus 2132: } else {
2133: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2134: packet_put_int(listen_port);
2135: packet_put_cstring(host_to_connect);
1.44 markus 2136: packet_put_int(port_to_connect);
2137: packet_send();
2138: packet_write_wait();
1.73 markus 2139:
2140: /* Wait for response from the remote side. */
1.140.2.1 jason 2141: type = packet_read();
1.73 markus 2142: switch (type) {
2143: case SSH_SMSG_SUCCESS:
2144: success = 1;
2145: break;
2146: case SSH_SMSG_FAILURE:
2147: log("Warning: Server denied remote port forwarding.");
2148: break;
2149: default:
2150: /* Unknown packet */
2151: packet_disconnect("Protocol error for port forward request:"
2152: "received packet type %d.", type);
2153: }
2154: }
2155: if (success) {
2156: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2157: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2158: permitted_opens[num_permitted_opens].listen_port = listen_port;
2159: num_permitted_opens++;
1.44 markus 2160: }
1.1 deraadt 2161: }
2162:
1.27 markus 2163: /*
2164: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2165: * listening for the port, and sends back a success reply (or disconnect
2166: * message if there was an error). This never returns if there was an error.
2167: */
1.1 deraadt 2168:
1.49 markus 2169: void
1.56 markus 2170: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2171: {
1.31 markus 2172: u_short port, host_port;
1.25 markus 2173: char *hostname;
1.1 deraadt 2174:
1.25 markus 2175: /* Get arguments from the packet. */
2176: port = packet_get_int();
2177: hostname = packet_get_string(NULL);
2178: host_port = packet_get_int();
2179:
1.27 markus 2180: /*
2181: * Check that an unprivileged user is not trying to forward a
2182: * privileged port.
2183: */
1.25 markus 2184: if (port < IPPORT_RESERVED && !is_root)
2185: packet_disconnect("Requested forwarding of port %d but user is not root.",
2186: port);
1.73 markus 2187: /* Initiate forwarding */
1.140.2.1 jason 2188: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2189:
2190: /* Free the argument string. */
2191: xfree(hostname);
1.1 deraadt 2192: }
2193:
1.99 markus 2194: /*
2195: * Permits opening to any host/port if permitted_opens[] is empty. This is
2196: * usually called by the server, because the user could connect to any port
2197: * anyway, and the server has no way to know but to trust the client anyway.
2198: */
2199: void
1.140.2.1 jason 2200: channel_permit_all_opens(void)
1.99 markus 2201: {
2202: if (num_permitted_opens == 0)
2203: all_opens_permitted = 1;
2204: }
2205:
1.101 markus 2206: void
1.99 markus 2207: channel_add_permitted_opens(char *host, int port)
2208: {
2209: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2210: fatal("channel_request_remote_forwarding: too many forwards");
2211: debug("allow port forwarding to host %s port %d", host, port);
2212:
2213: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2214: permitted_opens[num_permitted_opens].port_to_connect = port;
2215: num_permitted_opens++;
2216:
2217: all_opens_permitted = 0;
2218: }
2219:
1.101 markus 2220: void
1.99 markus 2221: channel_clear_permitted_opens(void)
2222: {
2223: int i;
2224:
2225: for (i = 0; i < num_permitted_opens; i++)
2226: xfree(permitted_opens[i].host_to_connect);
2227: num_permitted_opens = 0;
2228:
2229: }
2230:
2231:
2232: /* return socket to remote host, port */
1.127 itojun 2233: static int
1.99 markus 2234: connect_to(const char *host, u_short port)
1.41 markus 2235: {
2236: struct addrinfo hints, *ai, *aitop;
2237: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2238: int gaierr;
2239: int sock = -1;
2240:
2241: memset(&hints, 0, sizeof(hints));
2242: hints.ai_family = IPv4or6;
2243: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2244: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2245: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2246: error("connect_to %.100s: unknown host (%s)", host,
2247: gai_strerror(gaierr));
1.41 markus 2248: return -1;
2249: }
2250: for (ai = aitop; ai; ai = ai->ai_next) {
2251: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2252: continue;
2253: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2254: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2255: error("connect_to: getnameinfo failed");
1.41 markus 2256: continue;
2257: }
2258: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2259: if (sock < 0) {
2260: error("socket: %.100s", strerror(errno));
2261: continue;
2262: }
1.80 markus 2263: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2264: fatal("connect_to: F_SETFL: %s", strerror(errno));
2265: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2266: errno != EINPROGRESS) {
1.99 markus 2267: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2268: strerror(errno));
2269: close(sock);
1.89 stevesk 2270: continue; /* fail -- try next */
1.41 markus 2271: }
2272: break; /* success */
2273:
2274: }
2275: freeaddrinfo(aitop);
2276: if (!ai) {
1.99 markus 2277: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2278: return -1;
2279: }
2280: /* success */
1.140.2.1 jason 2281: set_nodelay(sock);
1.41 markus 2282: return sock;
2283: }
1.99 markus 2284:
1.73 markus 2285: int
1.130 stevesk 2286: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2287: {
2288: int i;
1.99 markus 2289:
1.73 markus 2290: for (i = 0; i < num_permitted_opens; i++)
2291: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2292: return connect_to(
1.73 markus 2293: permitted_opens[i].host_to_connect,
2294: permitted_opens[i].port_to_connect);
1.74 markus 2295: error("WARNING: Server requests forwarding for unknown listen_port %d",
2296: listen_port);
1.73 markus 2297: return -1;
2298: }
2299:
1.99 markus 2300: /* Check if connecting to that port is permitted and connect. */
2301: int
2302: channel_connect_to(const char *host, u_short port)
2303: {
2304: int i, permit;
2305:
2306: permit = all_opens_permitted;
2307: if (!permit) {
2308: for (i = 0; i < num_permitted_opens; i++)
2309: if (permitted_opens[i].port_to_connect == port &&
2310: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2311: permit = 1;
2312:
2313: }
2314: if (!permit) {
2315: log("Received request to connect to host %.100s port %d, "
2316: "but the request was denied.", host, port);
2317: return -1;
2318: }
2319: return connect_to(host, port);
2320: }
2321:
1.121 markus 2322: /* -- X11 forwarding */
1.1 deraadt 2323:
1.27 markus 2324: /*
2325: * Creates an internet domain socket for listening for X11 connections.
1.140.2.1 jason 2326: * Returns a suitable display number for the DISPLAY variable, or -1 if
2327: * an error occurs.
1.27 markus 2328: */
1.140.2.1 jason 2329: int
2330: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
2331: int single_connection)
1.1 deraadt 2332: {
1.140.2.1 jason 2333: Channel *nc = NULL;
1.31 markus 2334: int display_number, sock;
2335: u_short port;
1.35 markus 2336: struct addrinfo hints, *ai, *aitop;
2337: char strport[NI_MAXSERV];
2338: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2339:
1.33 markus 2340: for (display_number = x11_display_offset;
1.140.2.1 jason 2341: display_number < MAX_DISPLAYS;
2342: display_number++) {
1.25 markus 2343: port = 6000 + display_number;
1.35 markus 2344: memset(&hints, 0, sizeof(hints));
2345: hints.ai_family = IPv4or6;
1.140.2.1 jason 2346: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2347: hints.ai_socktype = SOCK_STREAM;
2348: snprintf(strport, sizeof strport, "%d", port);
2349: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2350: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.140.2.1 jason 2351: return -1;
1.25 markus 2352: }
1.35 markus 2353: for (ai = aitop; ai; ai = ai->ai_next) {
2354: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2355: continue;
2356: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2357: if (sock < 0) {
2358: error("socket: %.100s", strerror(errno));
1.140.2.1 jason 2359: return -1;
1.35 markus 2360: }
2361: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2362: debug("bind port %d: %.100s", port, strerror(errno));
2363: close(sock);
2364: for (n = 0; n < num_socks; n++) {
2365: close(socks[n]);
2366: }
2367: num_socks = 0;
2368: break;
2369: }
2370: socks[num_socks++] = sock;
2371: if (num_socks == NUM_SOCKS)
2372: break;
1.25 markus 2373: }
1.83 stevesk 2374: freeaddrinfo(aitop);
1.35 markus 2375: if (num_socks > 0)
2376: break;
1.25 markus 2377: }
2378: if (display_number >= MAX_DISPLAYS) {
2379: error("Failed to allocate internet-domain X11 display socket.");
1.140.2.1 jason 2380: return -1;
1.25 markus 2381: }
2382: /* Start listening for connections on the socket. */
1.35 markus 2383: for (n = 0; n < num_socks; n++) {
2384: sock = socks[n];
2385: if (listen(sock, 5) < 0) {
2386: error("listen: %.100s", strerror(errno));
2387: close(sock);
1.140.2.1 jason 2388: return -1;
1.35 markus 2389: }
1.25 markus 2390: }
1.35 markus 2391:
2392: /* Allocate a channel for each socket. */
2393: for (n = 0; n < num_socks; n++) {
2394: sock = socks[n];
1.140.2.1 jason 2395: nc = channel_new("x11 listener",
1.51 markus 2396: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2397: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2398: 0, xstrdup("X11 inet listener"), 1);
1.140.2.1 jason 2399: nc->single_connection = single_connection;
1.35 markus 2400: }
1.1 deraadt 2401:
1.140.2.1 jason 2402: /* Return the display number for the DISPLAY environment variable. */
2403: return display_number;
1.1 deraadt 2404: }
2405:
1.127 itojun 2406: static int
1.77 markus 2407: connect_local_xsocket(u_int dnr)
1.1 deraadt 2408: {
1.25 markus 2409: int sock;
2410: struct sockaddr_un addr;
2411:
1.140.2.1 jason 2412: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2413: if (sock < 0)
2414: error("socket: %.100s", strerror(errno));
2415: memset(&addr, 0, sizeof(addr));
2416: addr.sun_family = AF_UNIX;
2417: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2418: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2419: return sock;
2420: close(sock);
1.25 markus 2421: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2422: return -1;
1.1 deraadt 2423: }
2424:
1.51 markus 2425: int
2426: x11_connect_display(void)
1.1 deraadt 2427: {
1.51 markus 2428: int display_number, sock = 0;
1.25 markus 2429: const char *display;
1.51 markus 2430: char buf[1024], *cp;
1.35 markus 2431: struct addrinfo hints, *ai, *aitop;
2432: char strport[NI_MAXSERV];
2433: int gaierr;
1.25 markus 2434:
2435: /* Try to open a socket for the local X server. */
2436: display = getenv("DISPLAY");
2437: if (!display) {
2438: error("DISPLAY not set.");
1.51 markus 2439: return -1;
1.25 markus 2440: }
1.27 markus 2441: /*
2442: * Now we decode the value of the DISPLAY variable and make a
2443: * connection to the real X server.
2444: */
2445:
2446: /*
2447: * Check if it is a unix domain socket. Unix domain displays are in
2448: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2449: */
1.25 markus 2450: if (strncmp(display, "unix:", 5) == 0 ||
2451: display[0] == ':') {
2452: /* Connect to the unix domain socket. */
2453: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2454: error("Could not parse display number from DISPLAY: %.100s",
1.140.2.1 jason 2455: display);
1.51 markus 2456: return -1;
1.25 markus 2457: }
2458: /* Create a socket. */
2459: sock = connect_local_xsocket(display_number);
2460: if (sock < 0)
1.51 markus 2461: return -1;
1.25 markus 2462:
2463: /* OK, we now have a connection to the display. */
1.51 markus 2464: return sock;
1.25 markus 2465: }
1.27 markus 2466: /*
2467: * Connect to an inet socket. The DISPLAY value is supposedly
2468: * hostname:d[.s], where hostname may also be numeric IP address.
2469: */
1.140.2.1 jason 2470: strlcpy(buf, display, sizeof(buf));
1.25 markus 2471: cp = strchr(buf, ':');
2472: if (!cp) {
2473: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2474: return -1;
1.25 markus 2475: }
2476: *cp = 0;
1.27 markus 2477: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2478: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2479: error("Could not parse display number from DISPLAY: %.100s",
1.140.2.1 jason 2480: display);
1.51 markus 2481: return -1;
1.25 markus 2482: }
1.35 markus 2483:
2484: /* Look up the host address */
2485: memset(&hints, 0, sizeof(hints));
2486: hints.ai_family = IPv4or6;
2487: hints.ai_socktype = SOCK_STREAM;
2488: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2489: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2490: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2491: return -1;
1.25 markus 2492: }
1.35 markus 2493: for (ai = aitop; ai; ai = ai->ai_next) {
2494: /* Create a socket. */
2495: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2496: if (sock < 0) {
2497: debug("socket: %.100s", strerror(errno));
1.41 markus 2498: continue;
2499: }
2500: /* Connect it to the display. */
2501: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2502: debug("connect %.100s port %d: %.100s", buf,
2503: 6000 + display_number, strerror(errno));
2504: close(sock);
2505: continue;
2506: }
2507: /* Success */
2508: break;
1.35 markus 2509: }
2510: freeaddrinfo(aitop);
2511: if (!ai) {
1.49 markus 2512: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2513: strerror(errno));
1.51 markus 2514: return -1;
1.25 markus 2515: }
1.140.2.1 jason 2516: set_nodelay(sock);
1.51 markus 2517: return sock;
2518: }
2519:
2520: /*
2521: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2522: * the remote channel number. We should do whatever we want, and respond
2523: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2524: */
2525:
2526: void
1.140.2.1 jason 2527: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2528: {
1.113 markus 2529: Channel *c = NULL;
2530: int remote_id, sock = 0;
1.51 markus 2531: char *remote_host;
1.25 markus 2532:
1.113 markus 2533: debug("Received X11 open request.");
1.51 markus 2534:
1.113 markus 2535: remote_id = packet_get_int();
1.121 markus 2536:
2537: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2538: remote_host = packet_get_string(NULL);
1.51 markus 2539: } else {
2540: remote_host = xstrdup("unknown (remote did not supply name)");
2541: }
1.140.2.1 jason 2542: packet_check_eom();
1.25 markus 2543:
1.51 markus 2544: /* Obtain a connection to the real X display. */
2545: sock = x11_connect_display();
1.113 markus 2546: if (sock != -1) {
2547: /* Allocate a channel for this connection. */
2548: c = channel_new("connected x11 socket",
2549: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2550: remote_host, 1);
1.140.2.1 jason 2551: c->remote_id = remote_id;
2552: c->force_drain = 1;
1.113 markus 2553: }
2554: if (c == NULL) {
1.51 markus 2555: /* Send refusal to the remote host. */
2556: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2557: packet_put_int(remote_id);
1.51 markus 2558: } else {
2559: /* Send a confirmation to the remote host. */
2560: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2561: packet_put_int(remote_id);
2562: packet_put_int(c->self);
1.51 markus 2563: }
1.113 markus 2564: packet_send();
1.72 markus 2565: }
2566:
2567: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2568: void
1.140.2.1 jason 2569: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2570: {
2571: int rchan = packet_get_int();
1.140.2.1 jason 2572: switch (type) {
1.72 markus 2573: case SSH_SMSG_AGENT_OPEN:
2574: error("Warning: ssh server tried agent forwarding.");
2575: break;
2576: case SSH_SMSG_X11_OPEN:
2577: error("Warning: ssh server tried X11 forwarding.");
2578: break;
2579: default:
1.140.2.1 jason 2580: error("deny_input_open: type %d", type);
1.72 markus 2581: break;
2582: }
2583: error("Warning: this is probably a break in attempt by a malicious server.");
2584: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2585: packet_put_int(rchan);
2586: packet_send();
1.1 deraadt 2587: }
2588:
1.27 markus 2589: /*
2590: * Requests forwarding of X11 connections, generates fake authentication
2591: * data, and enables authentication spoofing.
1.121 markus 2592: * This should be called in the client only.
1.27 markus 2593: */
1.49 markus 2594: void
1.51 markus 2595: x11_request_forwarding_with_spoofing(int client_session_id,
2596: const char *proto, const char *data)
1.1 deraadt 2597: {
1.77 markus 2598: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2599: u_int i, value, len;
1.25 markus 2600: char *new_data;
2601: int screen_number;
2602: const char *cp;
2603: u_int32_t rand = 0;
2604:
2605: cp = getenv("DISPLAY");
2606: if (cp)
2607: cp = strchr(cp, ':');
2608: if (cp)
2609: cp = strchr(cp, '.');
2610: if (cp)
2611: screen_number = atoi(cp + 1);
2612: else
2613: screen_number = 0;
2614:
2615: /* Save protocol name. */
2616: x11_saved_proto = xstrdup(proto);
2617:
1.27 markus 2618: /*
2619: * Extract real authentication data and generate fake data of the
2620: * same length.
2621: */
1.25 markus 2622: x11_saved_data = xmalloc(data_len);
2623: x11_fake_data = xmalloc(data_len);
2624: for (i = 0; i < data_len; i++) {
2625: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2626: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2627: if (i % 4 == 0)
2628: rand = arc4random();
2629: x11_saved_data[i] = value;
2630: x11_fake_data[i] = rand & 0xff;
2631: rand >>= 8;
2632: }
2633: x11_saved_data_len = data_len;
2634: x11_fake_data_len = data_len;
2635:
2636: /* Convert the fake data into hex. */
1.90 markus 2637: len = 2 * data_len + 1;
2638: new_data = xmalloc(len);
1.25 markus 2639: for (i = 0; i < data_len; i++)
1.90 markus 2640: snprintf(new_data + 2 * i, len - 2 * i,
2641: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2642:
2643: /* Send the request packet. */
1.51 markus 2644: if (compat20) {
2645: channel_request_start(client_session_id, "x11-req", 0);
2646: packet_put_char(0); /* XXX bool single connection */
2647: } else {
2648: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2649: }
2650: packet_put_cstring(proto);
2651: packet_put_cstring(new_data);
1.25 markus 2652: packet_put_int(screen_number);
2653: packet_send();
2654: packet_write_wait();
2655: xfree(new_data);
1.1 deraadt 2656: }
2657:
1.121 markus 2658:
2659: /* -- agent forwarding */
2660:
1.1 deraadt 2661: /* Sends a message to the server to request authentication fd forwarding. */
2662:
1.49 markus 2663: void
1.140.2.1 jason 2664: auth_request_forwarding(void)
1.1 deraadt 2665: {
1.25 markus 2666: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2667: packet_send();
2668: packet_write_wait();
1.1 deraadt 2669: }
2670:
2671: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2672:
1.49 markus 2673: void
1.140.2.1 jason 2674: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2675: {
1.113 markus 2676: Channel *c = NULL;
2677: int remote_id, sock;
1.121 markus 2678: char *name;
1.41 markus 2679:
1.25 markus 2680: /* Read the remote channel number from the message. */
1.113 markus 2681: remote_id = packet_get_int();
1.140.2.1 jason 2682: packet_check_eom();
1.25 markus 2683:
1.27 markus 2684: /*
2685: * Get a connection to the local authentication agent (this may again
2686: * get forwarded).
2687: */
1.25 markus 2688: sock = ssh_get_authentication_socket();
2689:
1.27 markus 2690: /*
2691: * If we could not connect the agent, send an error message back to
2692: * the server. This should never happen unless the agent dies,
2693: * because authentication forwarding is only enabled if we have an
2694: * agent.
2695: */
1.113 markus 2696: if (sock >= 0) {
1.121 markus 2697: name = xstrdup("authentication agent connection");
2698: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2699: -1, 0, 0, 0, name, 1);
1.140.2.1 jason 2700: c->remote_id = remote_id;
2701: c->force_drain = 1;
1.113 markus 2702: }
2703: if (c == NULL) {
1.25 markus 2704: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2705: packet_put_int(remote_id);
2706: } else {
2707: /* Send a confirmation to the remote host. */
2708: debug("Forwarding authentication connection.");
2709: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2710: packet_put_int(remote_id);
2711: packet_put_int(c->self);
1.25 markus 2712: }
2713: packet_send();
1.1 deraadt 2714: }
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