Annotation of src/usr.bin/ssh/channels.c, Revision 1.131
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.
1.128 markus 16: * Copyright (c) 1999, 2000, 2001 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"
1.131 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.130 2001/06/30 18:08:39 stevesk Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
49: #include "uidswap.h"
1.82 markus 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.82 markus 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.44 markus 57:
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.1 deraadt 71: static int channels_alloc = 0;
72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
112: /* Saved X11 authentication protocol name. */
113: static char *x11_saved_proto = NULL;
114:
115: /* Saved X11 authentication data. This is the real data. */
116: static char *x11_saved_data = NULL;
117: static u_int x11_saved_data_len = 0;
118:
119: /*
120: * Fake X11 authentication data. This is what the server will be sending us;
121: * we should replace any occurrences of this by the real data.
122: */
123: static char *x11_fake_data = NULL;
124: static u_int x11_fake_data_len;
125:
126:
127: /* -- agent forwarding */
128:
129: #define NUM_SOCKS 10
130:
131: /* Name and directory of socket for authentication agent forwarding. */
132: static char *auth_sock_name = NULL;
133: static char *auth_sock_dir = NULL;
134:
1.82 markus 135: /* AF_UNSPEC or AF_INET or AF_INET6 */
136: extern int IPv4or6;
1.1 deraadt 137:
1.121 markus 138: /* helper */
1.127 itojun 139: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 140:
1.121 markus 141: /* -- channel core */
1.41 markus 142:
143: Channel *
144: channel_lookup(int id)
145: {
146: Channel *c;
1.113 markus 147:
1.63 provos 148: if (id < 0 || id > channels_alloc) {
1.41 markus 149: log("channel_lookup: %d: bad id", id);
150: return NULL;
151: }
1.113 markus 152: c = channels[id];
153: if (c == NULL) {
1.41 markus 154: log("channel_lookup: %d: bad id: channel free", id);
155: return NULL;
156: }
157: return c;
1.55 markus 158: }
159:
1.27 markus 160: /*
1.55 markus 161: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 162: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 163: */
1.1 deraadt 164:
1.127 itojun 165: static void
1.71 markus 166: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
167: int extusage, int nonblock)
1.1 deraadt 168: {
1.25 markus 169: /* Update the maximum file descriptor value. */
1.84 markus 170: channel_max_fd = MAX(channel_max_fd, rfd);
171: channel_max_fd = MAX(channel_max_fd, wfd);
172: channel_max_fd = MAX(channel_max_fd, efd);
173:
1.27 markus 174: /* XXX set close-on-exec -markus */
1.55 markus 175:
1.52 markus 176: c->rfd = rfd;
177: c->wfd = wfd;
178: c->sock = (rfd == wfd) ? rfd : -1;
179: c->efd = efd;
180: c->extended_usage = extusage;
1.71 markus 181:
1.91 markus 182: /* XXX ugly hack: nonblock is only set by the server */
183: if (nonblock && isatty(c->rfd)) {
1.94 markus 184: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 185: c->isatty = 1;
186: if (!isatty(c->wfd)) {
1.94 markus 187: error("channel %d: wfd %d is not a tty?",
1.91 markus 188: c->self, c->wfd);
189: }
190: } else {
191: c->isatty = 0;
192: }
193:
1.71 markus 194: /* enable nonblocking mode */
195: if (nonblock) {
196: if (rfd != -1)
197: set_nonblock(rfd);
198: if (wfd != -1)
199: set_nonblock(wfd);
200: if (efd != -1)
201: set_nonblock(efd);
202: }
1.52 markus 203: }
204:
205: /*
206: * Allocate a new channel object and set its type and socket. This will cause
207: * remote_name to be freed.
208: */
209:
1.113 markus 210: Channel *
1.52 markus 211: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 212: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 213: {
214: int i, found;
215: Channel *c;
1.25 markus 216:
217: /* Do initial allocation if this is the first call. */
218: if (channels_alloc == 0) {
1.44 markus 219: chan_init();
1.25 markus 220: channels_alloc = 10;
1.113 markus 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.113 markus 223: channels[i] = NULL;
1.126 markus 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.113 markus 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.25 markus 244: buffer_init(&c->input);
245: buffer_init(&c->output);
1.41 markus 246: buffer_init(&c->extended);
1.25 markus 247: chan_init_iostates(c);
1.71 markus 248: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 249: c->self = found;
250: c->type = type;
1.41 markus 251: c->ctype = ctype;
1.51 markus 252: c->local_window = window;
253: c->local_window_max = window;
254: c->local_consumed = 0;
255: c->local_maxpacket = maxpack;
1.25 markus 256: c->remote_id = -1;
257: c->remote_name = remote_name;
1.41 markus 258: c->remote_window = 0;
259: c->remote_maxpacket = 0;
260: c->cb_fn = NULL;
261: c->cb_arg = NULL;
262: c->cb_event = 0;
1.131 ! markus 263: c->detach_user = NULL;
1.65 markus 264: c->input_filter = NULL;
1.25 markus 265: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 266: return c;
1.1 deraadt 267: }
1.52 markus 268:
269: /* Close all channel fd/socket. */
270:
1.127 itojun 271: static void
1.52 markus 272: channel_close_fds(Channel *c)
273: {
1.118 markus 274: debug3("channel_close_fds: channel %d: r %d w %d e %d",
275: c->self, c->rfd, c->wfd, c->efd);
276:
1.52 markus 277: if (c->sock != -1) {
278: close(c->sock);
279: c->sock = -1;
280: }
281: if (c->rfd != -1) {
282: close(c->rfd);
1.121 markus 283: c->rfd = -1;
284: }
285: if (c->wfd != -1) {
286: close(c->wfd);
287: c->wfd = -1;
288: }
289: if (c->efd != -1) {
290: close(c->efd);
291: c->efd = -1;
292: }
293: }
294:
295: /* Free the channel and close its fd/socket. */
296:
297: void
298: channel_free(Channel *c)
299: {
300: char *s;
301: int i, n;
302:
303: for (n = 0, i = 0; i < channels_alloc; i++)
304: if (channels[i])
305: n++;
306: debug("channel_free: channel %d: %s, nchannels %d", c->self,
307: c->remote_name ? c->remote_name : "???", n);
308:
309: s = channel_open_message();
310: debug3("channel_free: status: %s", s);
311: xfree(s);
312:
1.131 ! markus 313: if (c->detach_user != NULL) {
! 314: debug("channel_free: channel %d: detaching channel user", c->self);
! 315: c->detach_user(c->self, NULL);
1.121 markus 316: }
317: if (c->sock != -1)
318: shutdown(c->sock, SHUT_RDWR);
319: channel_close_fds(c);
320: buffer_free(&c->input);
321: buffer_free(&c->output);
322: buffer_free(&c->extended);
323: if (c->remote_name) {
324: xfree(c->remote_name);
325: c->remote_name = NULL;
326: }
327: channels[c->self] = NULL;
328: xfree(c);
329: }
330:
331: void
1.126 markus 332: channel_free_all(void)
1.121 markus 333: {
334: int i;
335:
1.126 markus 336: for (i = 0; i < channels_alloc; i++)
337: if (channels[i] != NULL)
338: channel_free(channels[i]);
1.121 markus 339: }
340:
1.131 ! markus 341: void
! 342: channel_detach_all(void)
! 343: {
! 344: int i;
! 345: Channel *c;
! 346:
! 347: for (i = 0; i < channels_alloc; i++) {
! 348: c = channels[i];
! 349: if (c != NULL && c->detach_user != NULL) {
! 350: debug("channel_detach_all: channel %d", c->self);
! 351: c->detach_user(c->self, NULL);
! 352: c->detach_user = NULL;
! 353: }
! 354: }
! 355: }
! 356:
1.121 markus 357: /*
358: * Closes the sockets/fds of all channels. This is used to close extra file
359: * descriptors after a fork.
360: */
361:
362: void
363: channel_close_all()
364: {
365: int i;
366:
367: for (i = 0; i < channels_alloc; i++)
368: if (channels[i] != NULL)
369: channel_close_fds(channels[i]);
370: }
371:
372: /*
1.131 ! markus 373: * Stop listening to channels.
! 374: */
! 375:
! 376: void
! 377: channel_stop_listening(void)
! 378: {
! 379: int i;
! 380: Channel *c;
! 381:
! 382: for (i = 0; i < channels_alloc; i++) {
! 383: c = channels[i];
! 384: if (c != NULL) {
! 385: switch (c->type) {
! 386: case SSH_CHANNEL_AUTH_SOCKET:
! 387: case SSH_CHANNEL_PORT_LISTENER:
! 388: case SSH_CHANNEL_RPORT_LISTENER:
! 389: case SSH_CHANNEL_X11_LISTENER:
! 390: close(c->sock);
! 391: channel_free(c);
! 392: break;
! 393: }
! 394: }
! 395: }
! 396: }
! 397:
! 398: /*
1.121 markus 399: * Returns true if no channel has too much buffered data, and false if one or
400: * more channel is overfull.
401: */
402:
403: int
404: channel_not_very_much_buffered_data()
405: {
406: u_int i;
407: Channel *c;
408:
409: for (i = 0; i < channels_alloc; i++) {
410: c = channels[i];
411: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
412: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
413: debug("channel %d: big input buffer %d",
414: c->self, buffer_len(&c->input));
415: return 0;
416: }
417: if (buffer_len(&c->output) > packet_get_maxsize()) {
418: debug("channel %d: big output buffer %d",
419: c->self, buffer_len(&c->output));
420: return 0;
421: }
422: }
423: }
424: return 1;
425: }
426:
427: /* Returns true if any channel is still open. */
428:
429: int
430: channel_still_open()
431: {
432: int i;
433: Channel *c;
434:
435: for (i = 0; i < channels_alloc; i++) {
436: c = channels[i];
437: if (c == NULL)
438: continue;
439: switch (c->type) {
440: case SSH_CHANNEL_X11_LISTENER:
441: case SSH_CHANNEL_PORT_LISTENER:
442: case SSH_CHANNEL_RPORT_LISTENER:
443: case SSH_CHANNEL_CLOSED:
444: case SSH_CHANNEL_AUTH_SOCKET:
445: case SSH_CHANNEL_DYNAMIC:
446: case SSH_CHANNEL_CONNECTING:
447: case SSH_CHANNEL_ZOMBIE:
448: continue;
449: case SSH_CHANNEL_LARVAL:
450: if (!compat20)
451: fatal("cannot happen: SSH_CHANNEL_LARVAL");
452: continue;
453: case SSH_CHANNEL_OPENING:
454: case SSH_CHANNEL_OPEN:
455: case SSH_CHANNEL_X11_OPEN:
456: return 1;
457: case SSH_CHANNEL_INPUT_DRAINING:
458: case SSH_CHANNEL_OUTPUT_DRAINING:
459: if (!compat13)
460: fatal("cannot happen: OUT_DRAIN");
461: return 1;
462: default:
463: fatal("channel_still_open: bad channel type %d", c->type);
464: /* NOTREACHED */
465: }
466: }
467: return 0;
468: }
469:
470: /* Returns the id of an open channel suitable for keepaliving */
471:
472: int
473: channel_find_open()
474: {
475: int i;
476: Channel *c;
477:
478: for (i = 0; i < channels_alloc; i++) {
479: c = channels[i];
480: if (c == NULL)
481: continue;
482: switch (c->type) {
483: case SSH_CHANNEL_CLOSED:
484: case SSH_CHANNEL_DYNAMIC:
485: case SSH_CHANNEL_X11_LISTENER:
486: case SSH_CHANNEL_PORT_LISTENER:
487: case SSH_CHANNEL_RPORT_LISTENER:
488: case SSH_CHANNEL_OPENING:
489: case SSH_CHANNEL_CONNECTING:
490: case SSH_CHANNEL_ZOMBIE:
491: continue;
492: case SSH_CHANNEL_LARVAL:
493: case SSH_CHANNEL_AUTH_SOCKET:
494: case SSH_CHANNEL_OPEN:
495: case SSH_CHANNEL_X11_OPEN:
496: return i;
497: case SSH_CHANNEL_INPUT_DRAINING:
498: case SSH_CHANNEL_OUTPUT_DRAINING:
499: if (!compat13)
500: fatal("cannot happen: OUT_DRAIN");
501: return i;
502: default:
503: fatal("channel_find_open: bad channel type %d", c->type);
504: /* NOTREACHED */
505: }
506: }
507: return -1;
508: }
509:
510:
511: /*
512: * Returns a message describing the currently open forwarded connections,
513: * suitable for sending to the client. The message contains crlf pairs for
514: * newlines.
515: */
516:
517: char *
518: channel_open_message()
519: {
520: Buffer buffer;
521: Channel *c;
522: char buf[1024], *cp;
523: int i;
524:
525: buffer_init(&buffer);
526: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
527: buffer_append(&buffer, buf, strlen(buf));
528: for (i = 0; i < channels_alloc; i++) {
529: c = channels[i];
530: if (c == NULL)
531: continue;
532: switch (c->type) {
533: case SSH_CHANNEL_X11_LISTENER:
534: case SSH_CHANNEL_PORT_LISTENER:
535: case SSH_CHANNEL_RPORT_LISTENER:
536: case SSH_CHANNEL_CLOSED:
537: case SSH_CHANNEL_AUTH_SOCKET:
538: case SSH_CHANNEL_ZOMBIE:
539: continue;
540: case SSH_CHANNEL_LARVAL:
541: case SSH_CHANNEL_OPENING:
542: case SSH_CHANNEL_CONNECTING:
543: case SSH_CHANNEL_DYNAMIC:
544: case SSH_CHANNEL_OPEN:
545: case SSH_CHANNEL_X11_OPEN:
546: case SSH_CHANNEL_INPUT_DRAINING:
547: case SSH_CHANNEL_OUTPUT_DRAINING:
548: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
549: c->self, c->remote_name,
550: c->type, c->remote_id,
551: c->istate, buffer_len(&c->input),
552: c->ostate, buffer_len(&c->output),
553: c->rfd, c->wfd);
554: buffer_append(&buffer, buf, strlen(buf));
555: continue;
556: default:
557: fatal("channel_open_message: bad channel type %d", c->type);
558: /* NOTREACHED */
559: }
560: }
561: buffer_append(&buffer, "\0", 1);
562: cp = xstrdup(buffer_ptr(&buffer));
563: buffer_free(&buffer);
564: return cp;
565: }
566:
567: void
568: channel_send_open(int id)
569: {
570: Channel *c = channel_lookup(id);
571: if (c == NULL) {
572: log("channel_send_open: %d: bad id", id);
573: return;
574: }
575: debug("send channel open %d", id);
576: packet_start(SSH2_MSG_CHANNEL_OPEN);
577: packet_put_cstring(c->ctype);
578: packet_put_int(c->self);
579: packet_put_int(c->local_window);
580: packet_put_int(c->local_maxpacket);
581: packet_send();
582: }
583:
584: void
585: channel_request(int id, char *service, int wantconfirm)
586: {
587: channel_request_start(id, service, wantconfirm);
588: packet_send();
589: debug("channel request %d: %s", id, service) ;
590: }
591: void
592: channel_request_start(int id, char *service, int wantconfirm)
593: {
594: Channel *c = channel_lookup(id);
595: if (c == NULL) {
596: log("channel_request: %d: bad id", id);
597: return;
598: }
599: packet_start(SSH2_MSG_CHANNEL_REQUEST);
600: packet_put_int(c->remote_id);
601: packet_put_cstring(service);
602: packet_put_char(wantconfirm);
603: }
604: void
605: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
606: {
607: Channel *c = channel_lookup(id);
608: if (c == NULL) {
609: log("channel_register_callback: %d: bad id", id);
610: return;
611: }
612: c->cb_event = mtype;
613: c->cb_fn = fn;
614: c->cb_arg = arg;
615: }
616: void
617: channel_register_cleanup(int id, channel_callback_fn *fn)
618: {
619: Channel *c = channel_lookup(id);
620: if (c == NULL) {
621: log("channel_register_cleanup: %d: bad id", id);
622: return;
623: }
1.131 ! markus 624: c->detach_user = fn;
1.121 markus 625: }
626: void
627: channel_cancel_cleanup(int id)
628: {
629: Channel *c = channel_lookup(id);
630: if (c == NULL) {
631: log("channel_cancel_cleanup: %d: bad id", id);
632: return;
1.52 markus 633: }
1.131 ! markus 634: c->detach_user = NULL;
1.121 markus 635: }
636: void
637: channel_register_filter(int id, channel_filter_fn *fn)
638: {
639: Channel *c = channel_lookup(id);
640: if (c == NULL) {
641: log("channel_register_filter: %d: bad id", id);
642: return;
1.52 markus 643: }
1.121 markus 644: c->input_filter = fn;
1.52 markus 645: }
646:
1.49 markus 647: void
1.121 markus 648: channel_set_fds(int id, int rfd, int wfd, int efd,
649: int extusage, int nonblock)
1.1 deraadt 650: {
1.121 markus 651: Channel *c = channel_lookup(id);
652: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
653: fatal("channel_activate for non-larval channel %d.", id);
654: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
655: c->type = SSH_CHANNEL_OPEN;
656: /* XXX window size? */
657: c->local_window = c->local_window_max = c->local_maxpacket * 2;
658: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
659: packet_put_int(c->remote_id);
660: packet_put_int(c->local_window);
661: packet_send();
1.1 deraadt 662: }
663:
1.27 markus 664: /*
1.41 markus 665: * 'channel_pre*' are called just before select() to add any bits relevant to
666: * channels in the select bitmasks.
667: */
668: /*
669: * 'channel_post*': perform any appropriate operations for channels which
670: * have events pending.
1.27 markus 671: */
1.41 markus 672: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
673: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
674: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
675:
1.127 itojun 676: static void
1.41 markus 677: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
678: {
679: FD_SET(c->sock, readset);
680: }
681:
1.127 itojun 682: static void
1.75 markus 683: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
684: {
685: debug3("channel %d: waiting for connection", c->self);
686: FD_SET(c->sock, writeset);
687: }
688:
1.127 itojun 689: static void
1.41 markus 690: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
691: {
692: if (buffer_len(&c->input) < packet_get_maxsize())
693: FD_SET(c->sock, readset);
694: if (buffer_len(&c->output) > 0)
695: FD_SET(c->sock, writeset);
696: }
1.1 deraadt 697:
1.127 itojun 698: static void
1.41 markus 699: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
700: {
701: /* test whether sockets are 'alive' for read/write */
702: if (c->istate == CHAN_INPUT_OPEN)
703: if (buffer_len(&c->input) < packet_get_maxsize())
704: FD_SET(c->sock, readset);
705: if (c->ostate == CHAN_OUTPUT_OPEN ||
706: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
707: if (buffer_len(&c->output) > 0) {
708: FD_SET(c->sock, writeset);
709: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
710: chan_obuf_empty(c);
711: }
712: }
713: }
714:
1.127 itojun 715: static void
1.44 markus 716: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
717: {
718: if (c->istate == CHAN_INPUT_OPEN &&
719: c->remote_window > 0 &&
720: buffer_len(&c->input) < c->remote_window)
721: FD_SET(c->rfd, readset);
722: if (c->ostate == CHAN_OUTPUT_OPEN ||
723: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
724: if (buffer_len(&c->output) > 0) {
725: FD_SET(c->wfd, writeset);
726: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
727: chan_obuf_empty(c);
728: }
729: }
730: /** XXX check close conditions, too */
731: if (c->efd != -1) {
732: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
733: buffer_len(&c->extended) > 0)
734: FD_SET(c->efd, writeset);
735: else if (c->extended_usage == CHAN_EXTENDED_READ &&
736: buffer_len(&c->extended) < c->remote_window)
737: FD_SET(c->efd, readset);
738: }
739: }
740:
1.127 itojun 741: static void
1.41 markus 742: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
743: {
744: if (buffer_len(&c->input) == 0) {
745: packet_start(SSH_MSG_CHANNEL_CLOSE);
746: packet_put_int(c->remote_id);
747: packet_send();
748: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 749: debug("channel %d: closing after input drain.", c->self);
1.41 markus 750: }
751: }
752:
1.127 itojun 753: static void
1.41 markus 754: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
755: {
756: if (buffer_len(&c->output) == 0)
1.113 markus 757: chan_mark_dead(c);
1.49 markus 758: else
1.41 markus 759: FD_SET(c->sock, writeset);
760: }
761:
762: /*
763: * This is a special state for X11 authentication spoofing. An opened X11
764: * connection (when authentication spoofing is being done) remains in this
765: * state until the first packet has been completely read. The authentication
766: * data in that packet is then substituted by the real data if it matches the
767: * fake data, and the channel is put into normal mode.
1.51 markus 768: * XXX All this happens at the client side.
1.121 markus 769: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 770: */
1.127 itojun 771: static int
1.121 markus 772: x11_open_helper(Buffer *b)
1.1 deraadt 773: {
1.77 markus 774: u_char *ucp;
775: u_int proto_len, data_len;
1.25 markus 776:
1.41 markus 777: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 778: if (buffer_len(b) < 12)
1.41 markus 779: return 0;
780:
781: /* Parse the lengths of variable-length fields. */
1.121 markus 782: ucp = (u_char *) buffer_ptr(b);
1.41 markus 783: if (ucp[0] == 0x42) { /* Byte order MSB first. */
784: proto_len = 256 * ucp[6] + ucp[7];
785: data_len = 256 * ucp[8] + ucp[9];
786: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
787: proto_len = ucp[6] + 256 * ucp[7];
788: data_len = ucp[8] + 256 * ucp[9];
789: } else {
790: debug("Initial X11 packet contains bad byte order byte: 0x%x",
791: ucp[0]);
792: return -1;
793: }
794:
795: /* Check if the whole packet is in buffer. */
1.121 markus 796: if (buffer_len(b) <
1.41 markus 797: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
798: return 0;
799:
800: /* Check if authentication protocol matches. */
801: if (proto_len != strlen(x11_saved_proto) ||
802: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
803: debug("X11 connection uses different authentication protocol.");
804: return -1;
805: }
806: /* Check if authentication data matches our fake data. */
807: if (data_len != x11_fake_data_len ||
808: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
809: x11_fake_data, x11_fake_data_len) != 0) {
810: debug("X11 auth data does not match fake data.");
811: return -1;
812: }
813: /* Check fake data length */
814: if (x11_fake_data_len != x11_saved_data_len) {
815: error("X11 fake_data_len %d != saved_data_len %d",
816: x11_fake_data_len, x11_saved_data_len);
817: return -1;
818: }
819: /*
820: * Received authentication protocol and data match
821: * our fake data. Substitute the fake data with real
822: * data.
823: */
824: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
825: x11_saved_data, x11_saved_data_len);
826: return 1;
827: }
828:
1.127 itojun 829: static void
1.41 markus 830: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
831: {
1.121 markus 832: int ret = x11_open_helper(&c->output);
1.41 markus 833: if (ret == 1) {
834: /* Start normal processing for the channel. */
835: c->type = SSH_CHANNEL_OPEN;
1.47 markus 836: channel_pre_open_13(c, readset, writeset);
1.41 markus 837: } else if (ret == -1) {
838: /*
839: * We have received an X11 connection that has bad
840: * authentication information.
841: */
1.98 millert 842: log("X11 connection rejected because of wrong authentication.");
1.41 markus 843: buffer_clear(&c->input);
844: buffer_clear(&c->output);
845: close(c->sock);
846: c->sock = -1;
847: c->type = SSH_CHANNEL_CLOSED;
848: packet_start(SSH_MSG_CHANNEL_CLOSE);
849: packet_put_int(c->remote_id);
850: packet_send();
851: }
852: }
1.25 markus 853:
1.127 itojun 854: static void
1.51 markus 855: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 856: {
1.121 markus 857: int ret = x11_open_helper(&c->output);
1.41 markus 858: if (ret == 1) {
859: c->type = SSH_CHANNEL_OPEN;
1.57 markus 860: if (compat20)
861: channel_pre_open_20(c, readset, writeset);
862: else
863: channel_pre_open_15(c, readset, writeset);
1.41 markus 864: } else if (ret == -1) {
865: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 866: chan_read_failed(c); /** force close? */
1.41 markus 867: chan_write_failed(c);
868: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
869: }
870: }
1.25 markus 871:
1.104 markus 872: /* try to decode a socks4 header */
1.127 itojun 873: static int
1.104 markus 874: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 875: {
876: u_char *p, *host;
1.109 markus 877: int len, have, i, found;
1.104 markus 878: char username[256];
1.103 markus 879: struct {
880: u_int8_t version;
881: u_int8_t command;
882: u_int16_t dest_port;
1.104 markus 883: struct in_addr dest_addr;
1.103 markus 884: } s4_req, s4_rsp;
885:
1.104 markus 886: debug2("channel %d: decode socks4", c->self);
1.109 markus 887:
888: have = buffer_len(&c->input);
889: len = sizeof(s4_req);
890: if (have < len)
891: return 0;
892: p = buffer_ptr(&c->input);
893: for (found = 0, i = len; i < have; i++) {
894: if (p[i] == '\0') {
895: found = 1;
896: break;
897: }
898: if (i > 1024) {
899: /* the peer is probably sending garbage */
900: debug("channel %d: decode socks4: too long",
901: c->self);
902: return -1;
903: }
904: }
905: if (!found)
906: return 0;
1.103 markus 907: buffer_get(&c->input, (char *)&s4_req.version, 1);
908: buffer_get(&c->input, (char *)&s4_req.command, 1);
909: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 910: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 911: have = buffer_len(&c->input);
1.103 markus 912: p = buffer_ptr(&c->input);
913: len = strlen(p);
1.106 markus 914: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 915: if (len > have)
1.104 markus 916: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 917: c->self, len, have);
918: strlcpy(username, p, sizeof(username));
919: buffer_consume(&c->input, len);
920: buffer_consume(&c->input, 1); /* trailing '\0' */
921:
1.104 markus 922: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 923: strlcpy(c->path, host, sizeof(c->path));
924: c->host_port = ntohs(s4_req.dest_port);
925:
1.106 markus 926: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
927: c->self, host, c->host_port, s4_req.command);
1.103 markus 928:
1.104 markus 929: if (s4_req.command != 1) {
930: debug("channel %d: cannot handle: socks4 cn %d",
931: c->self, s4_req.command);
932: return -1;
1.103 markus 933: }
1.104 markus 934: s4_rsp.version = 0; /* vn: 0 for reply */
935: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 936: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 937: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 938: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 939: return 1;
940: }
941:
942: /* dynamic port forwarding */
1.127 itojun 943: static void
1.104 markus 944: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
945: {
946: u_char *p;
947: int have, ret;
1.103 markus 948:
1.104 markus 949: have = buffer_len(&c->input);
950:
951: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 952: /* buffer_dump(&c->input); */
1.104 markus 953: /* check if the fixed size part of the packet is in buffer. */
954: if (have < 4) {
955: /* need more */
956: FD_SET(c->sock, readset);
957: return;
958: }
959: /* try to guess the protocol */
960: p = buffer_ptr(&c->input);
961: switch (p[0]) {
962: case 0x04:
963: ret = channel_decode_socks4(c, readset, writeset);
964: break;
965: default:
966: ret = -1;
967: break;
968: }
969: if (ret < 0) {
1.113 markus 970: chan_mark_dead(c);
1.104 markus 971: } else if (ret == 0) {
972: debug2("channel %d: pre_dynamic: need more", c->self);
973: /* need more */
974: FD_SET(c->sock, readset);
975: } else {
976: /* switch to the next state */
977: c->type = SSH_CHANNEL_OPENING;
978: port_open_helper(c, "direct-tcpip");
979: }
1.103 markus 980: }
981:
1.41 markus 982: /* This is our fake X11 server socket. */
1.127 itojun 983: static void
1.41 markus 984: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
985: {
1.113 markus 986: Channel *nc;
1.41 markus 987: struct sockaddr addr;
1.113 markus 988: int newsock;
1.41 markus 989: socklen_t addrlen;
1.85 markus 990: char buf[16384], *remote_ipaddr;
1.51 markus 991: int remote_port;
1.25 markus 992:
1.41 markus 993: if (FD_ISSET(c->sock, readset)) {
994: debug("X11 connection requested.");
995: addrlen = sizeof(addr);
996: newsock = accept(c->sock, &addr, &addrlen);
997: if (newsock < 0) {
998: error("accept: %.100s", strerror(errno));
999: return;
1000: }
1.85 markus 1001: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1002: remote_port = get_peer_port(newsock);
1.41 markus 1003: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1004: remote_ipaddr, remote_port);
1.51 markus 1005:
1.113 markus 1006: nc = channel_new("accepted x11 socket",
1.51 markus 1007: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1008: c->local_window_max, c->local_maxpacket,
1.71 markus 1009: 0, xstrdup(buf), 1);
1.113 markus 1010: if (nc == NULL) {
1011: close(newsock);
1012: xfree(remote_ipaddr);
1013: return;
1014: }
1.51 markus 1015: if (compat20) {
1016: packet_start(SSH2_MSG_CHANNEL_OPEN);
1017: packet_put_cstring("x11");
1.113 markus 1018: packet_put_int(nc->self);
1.51 markus 1019: packet_put_int(c->local_window_max);
1020: packet_put_int(c->local_maxpacket);
1.85 markus 1021: /* originator ipaddr and port */
1022: packet_put_cstring(remote_ipaddr);
1.57 markus 1023: if (datafellows & SSH_BUG_X11FWD) {
1024: debug("ssh2 x11 bug compat mode");
1025: } else {
1026: packet_put_int(remote_port);
1027: }
1.51 markus 1028: packet_send();
1029: } else {
1030: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1031: packet_put_int(nc->self);
1.121 markus 1032: if (packet_get_protocol_flags() &
1033: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1034: packet_put_cstring(buf);
1.51 markus 1035: packet_send();
1036: }
1.85 markus 1037: xfree(remote_ipaddr);
1.41 markus 1038: }
1039: }
1.25 markus 1040:
1.127 itojun 1041: static void
1.103 markus 1042: port_open_helper(Channel *c, char *rtype)
1043: {
1044: int direct;
1045: char buf[1024];
1046: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1047: u_short remote_port = get_peer_port(c->sock);
1048:
1049: direct = (strcmp(rtype, "direct-tcpip") == 0);
1050:
1051: snprintf(buf, sizeof buf,
1052: "%s: listening port %d for %.100s port %d, "
1053: "connect from %.200s port %d",
1054: rtype, c->listening_port, c->path, c->host_port,
1055: remote_ipaddr, remote_port);
1056:
1057: xfree(c->remote_name);
1058: c->remote_name = xstrdup(buf);
1059:
1060: if (compat20) {
1061: packet_start(SSH2_MSG_CHANNEL_OPEN);
1062: packet_put_cstring(rtype);
1063: packet_put_int(c->self);
1064: packet_put_int(c->local_window_max);
1065: packet_put_int(c->local_maxpacket);
1066: if (direct) {
1067: /* target host, port */
1068: packet_put_cstring(c->path);
1069: packet_put_int(c->host_port);
1070: } else {
1071: /* listen address, port */
1072: packet_put_cstring(c->path);
1073: packet_put_int(c->listening_port);
1074: }
1075: /* originator host and port */
1076: packet_put_cstring(remote_ipaddr);
1077: packet_put_int(remote_port);
1078: packet_send();
1079: } else {
1080: packet_start(SSH_MSG_PORT_OPEN);
1081: packet_put_int(c->self);
1082: packet_put_cstring(c->path);
1083: packet_put_int(c->host_port);
1.121 markus 1084: if (packet_get_protocol_flags() &
1085: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1086: packet_put_cstring(c->remote_name);
1087: packet_send();
1088: }
1089: xfree(remote_ipaddr);
1090: }
1091:
1.41 markus 1092: /*
1093: * This socket is listening for connections to a forwarded TCP/IP port.
1094: */
1.127 itojun 1095: static void
1.41 markus 1096: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1097: {
1.103 markus 1098: Channel *nc;
1.41 markus 1099: struct sockaddr addr;
1.113 markus 1100: int newsock, nextstate;
1.41 markus 1101: socklen_t addrlen;
1.103 markus 1102: char *rtype;
1.73 markus 1103:
1.41 markus 1104: if (FD_ISSET(c->sock, readset)) {
1105: debug("Connection to port %d forwarding "
1106: "to %.100s port %d requested.",
1107: c->listening_port, c->path, c->host_port);
1.103 markus 1108:
1109: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
1110: "forwarded-tcpip" : "direct-tcpip";
1.115 markus 1111: nextstate = (c->host_port == 0 &&
1112: c->type != SSH_CHANNEL_RPORT_LISTENER) ?
1113: SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
1.103 markus 1114:
1.41 markus 1115: addrlen = sizeof(addr);
1116: newsock = accept(c->sock, &addr, &addrlen);
1117: if (newsock < 0) {
1118: error("accept: %.100s", strerror(errno));
1119: return;
1120: }
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: if (nc == NULL) {
1.113 markus 1126: error("channel_post_port_listener: no new channel:");
1127: close(newsock);
1.103 markus 1128: return;
1.41 markus 1129: }
1.103 markus 1130: nc->listening_port = c->listening_port;
1131: nc->host_port = c->host_port;
1132: strlcpy(nc->path, c->path, sizeof(nc->path));
1133:
1134: if (nextstate != SSH_CHANNEL_DYNAMIC)
1135: port_open_helper(nc, rtype);
1.41 markus 1136: }
1137: }
1.25 markus 1138:
1.41 markus 1139: /*
1140: * This is the authentication agent socket listening for connections from
1141: * clients.
1142: */
1.127 itojun 1143: static void
1.41 markus 1144: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1145: {
1.113 markus 1146: Channel *nc;
1.121 markus 1147: char *name;
1.113 markus 1148: int newsock;
1.41 markus 1149: struct sockaddr addr;
1150: socklen_t addrlen;
1.25 markus 1151:
1.41 markus 1152: if (FD_ISSET(c->sock, readset)) {
1153: addrlen = sizeof(addr);
1154: newsock = accept(c->sock, &addr, &addrlen);
1155: if (newsock < 0) {
1156: error("accept from auth socket: %.100s", strerror(errno));
1157: return;
1158: }
1.121 markus 1159: name = xstrdup("accepted auth socket");
1.113 markus 1160: nc = channel_new("accepted auth socket",
1.73 markus 1161: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1162: c->local_window_max, c->local_maxpacket,
1.121 markus 1163: 0, name, 1);
1.113 markus 1164: if (nc == NULL) {
1165: error("channel_post_auth_listener: channel_new failed");
1.121 markus 1166: xfree(name);
1.113 markus 1167: close(newsock);
1168: }
1.73 markus 1169: if (compat20) {
1170: packet_start(SSH2_MSG_CHANNEL_OPEN);
1171: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1172: packet_put_int(nc->self);
1.73 markus 1173: packet_put_int(c->local_window_max);
1174: packet_put_int(c->local_maxpacket);
1175: } else {
1176: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1177: packet_put_int(nc->self);
1.73 markus 1178: }
1.41 markus 1179: packet_send();
1180: }
1181: }
1.25 markus 1182:
1.127 itojun 1183: static void
1.75 markus 1184: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1185: {
1.114 markus 1186: int err = 0;
1.129 stevesk 1187: socklen_t sz = sizeof(err);
1.114 markus 1188:
1.75 markus 1189: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1190: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1191: &sz) < 0) {
1192: err = errno;
1193: error("getsockopt SO_ERROR failed");
1194: }
1195: if (err == 0) {
1196: debug("channel %d: connected", c->self);
1197: c->type = SSH_CHANNEL_OPEN;
1198: if (compat20) {
1199: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1200: packet_put_int(c->remote_id);
1201: packet_put_int(c->self);
1202: packet_put_int(c->local_window);
1203: packet_put_int(c->local_maxpacket);
1204: } else {
1205: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1206: packet_put_int(c->remote_id);
1207: packet_put_int(c->self);
1208: }
1.75 markus 1209: } else {
1.114 markus 1210: debug("channel %d: not connected: %s",
1211: c->self, strerror(err));
1212: if (compat20) {
1213: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1214: packet_put_int(c->remote_id);
1215: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1216: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1217: packet_put_cstring(strerror(err));
1218: packet_put_cstring("");
1219: }
1.75 markus 1220: } else {
1.114 markus 1221: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1222: packet_put_int(c->remote_id);
1.75 markus 1223: }
1.114 markus 1224: chan_mark_dead(c);
1.75 markus 1225: }
1.114 markus 1226: packet_send();
1.75 markus 1227: }
1228: }
1229:
1.127 itojun 1230: static int
1.41 markus 1231: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1232: {
1233: char buf[16*1024];
1234: int len;
1.25 markus 1235:
1.118 markus 1236: if (c->rfd != -1 &&
1.41 markus 1237: FD_ISSET(c->rfd, readset)) {
1238: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1239: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1240: return 1;
1.41 markus 1241: if (len <= 0) {
1.51 markus 1242: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1243: c->self, c->rfd, len);
1.104 markus 1244: if (c->type != SSH_CHANNEL_OPEN) {
1245: debug("channel %d: not open", c->self);
1.113 markus 1246: chan_mark_dead(c);
1.103 markus 1247: return -1;
1.104 markus 1248: } else if (compat13) {
1.41 markus 1249: buffer_consume(&c->output, buffer_len(&c->output));
1250: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1251: debug("channel %d: input draining.", c->self);
1.25 markus 1252: } else {
1.41 markus 1253: chan_read_failed(c);
1.25 markus 1254: }
1.41 markus 1255: return -1;
1256: }
1.65 markus 1257: if(c->input_filter != NULL) {
1.66 markus 1258: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1259: debug("channel %d: filter stops", c->self);
1.65 markus 1260: chan_read_failed(c);
1261: }
1262: } else {
1263: buffer_append(&c->input, buf, len);
1264: }
1.41 markus 1265: }
1266: return 1;
1267: }
1.127 itojun 1268: static int
1.41 markus 1269: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1270: {
1.95 markus 1271: struct termios tio;
1.41 markus 1272: int len;
1.25 markus 1273:
1.41 markus 1274: /* Send buffered output data to the socket. */
1.118 markus 1275: if (c->wfd != -1 &&
1.41 markus 1276: FD_ISSET(c->wfd, writeset) &&
1277: buffer_len(&c->output) > 0) {
1278: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 1279: buffer_len(&c->output));
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) {
1.41 markus 1288: buffer_consume(&c->output, buffer_len(&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: }
1296: if (compat20 && c->isatty) {
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);
1336: close(c->efd);
1337: c->efd = -1;
1338: } else {
1.44 markus 1339: buffer_consume(&c->extended, len);
1340: c->local_consumed += len;
1341: }
1342: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1343: FD_ISSET(c->efd, readset)) {
1344: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1345: debug2("channel %d: read %d from efd %d",
1.44 markus 1346: c->self, len, c->efd);
1.93 markus 1347: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1348: return 1;
1349: if (len <= 0) {
1350: debug2("channel %d: closing read-efd %d",
1.45 markus 1351: c->self, c->efd);
1352: close(c->efd);
1353: c->efd = -1;
1.93 markus 1354: } else {
1.44 markus 1355: buffer_append(&c->extended, buf, len);
1.93 markus 1356: }
1.44 markus 1357: }
1358: }
1359: return 1;
1360: }
1.127 itojun 1361: static int
1.93 markus 1362: channel_check_window(Channel *c)
1.44 markus 1363: {
1.104 markus 1364: if (c->type == SSH_CHANNEL_OPEN &&
1365: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1366: c->local_window < c->local_window_max/2 &&
1367: c->local_consumed > 0) {
1368: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1369: packet_put_int(c->remote_id);
1370: packet_put_int(c->local_consumed);
1371: packet_send();
1.70 markus 1372: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1373: c->self, c->local_window,
1374: c->local_consumed);
1375: c->local_window += c->local_consumed;
1376: c->local_consumed = 0;
1.1 deraadt 1377: }
1.41 markus 1378: return 1;
1.1 deraadt 1379: }
1380:
1.127 itojun 1381: static void
1.41 markus 1382: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1383: {
1384: channel_handle_rfd(c, readset, writeset);
1385: channel_handle_wfd(c, readset, writeset);
1386: }
1.1 deraadt 1387:
1.127 itojun 1388: static void
1.44 markus 1389: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1390: {
1391: channel_handle_rfd(c, readset, writeset);
1392: channel_handle_wfd(c, readset, writeset);
1393: channel_handle_efd(c, readset, writeset);
1.93 markus 1394:
1395: channel_check_window(c);
1.44 markus 1396: }
1397:
1.127 itojun 1398: static void
1.41 markus 1399: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1400: {
1.41 markus 1401: int len;
1402: /* Send buffered output data to the socket. */
1403: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1404: len = write(c->sock, buffer_ptr(&c->output),
1405: buffer_len(&c->output));
1406: if (len <= 0)
1407: buffer_consume(&c->output, buffer_len(&c->output));
1408: else
1409: buffer_consume(&c->output, len);
1410: }
1411: }
1.25 markus 1412:
1.127 itojun 1413: static void
1.44 markus 1414: channel_handler_init_20(void)
1415: {
1416: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1417: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1418: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1419: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1420: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1421: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1422: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1423: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1424:
1425: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1426: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1427: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1428: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1429: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1430: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1431: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1432: }
1433:
1.127 itojun 1434: static void
1.41 markus 1435: channel_handler_init_13(void)
1436: {
1437: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1438: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1439: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1440: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1441: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1442: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1443: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1444: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1445: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1446:
1.41 markus 1447: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1448: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1449: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1450: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1451: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1452: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1453: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1454: }
1.25 markus 1455:
1.127 itojun 1456: static void
1.41 markus 1457: channel_handler_init_15(void)
1458: {
1459: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1460: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1461: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1462: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1463: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1464: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1465: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1466:
1.41 markus 1467: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1468: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1469: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1470: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1471: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1472: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1473: }
1.27 markus 1474:
1.127 itojun 1475: static void
1.41 markus 1476: channel_handler_init(void)
1477: {
1478: int i;
1479: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1480: channel_pre[i] = NULL;
1481: channel_post[i] = NULL;
1482: }
1.44 markus 1483: if (compat20)
1484: channel_handler_init_20();
1485: else if (compat13)
1.41 markus 1486: channel_handler_init_13();
1487: else
1488: channel_handler_init_15();
1489: }
1.25 markus 1490:
1.127 itojun 1491: static void
1.41 markus 1492: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1493: {
1494: static int did_init = 0;
1495: int i;
1496: Channel *c;
1.25 markus 1497:
1.41 markus 1498: if (!did_init) {
1499: channel_handler_init();
1500: did_init = 1;
1501: }
1502: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1503: c = channels[i];
1504: if (c == NULL)
1.41 markus 1505: continue;
1.118 markus 1506: if (ftab[c->type] != NULL)
1507: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1508: if (chan_is_dead(c)) {
1509: /*
1510: * we have to remove the fd's from the select mask
1511: * before the channels are free'd and the fd's are
1512: * closed
1513: */
1514: if (c->wfd != -1)
1515: FD_CLR(c->wfd, writeset);
1516: if (c->rfd != -1)
1517: FD_CLR(c->rfd, readset);
1518: if (c->efd != -1) {
1519: if (c->extended_usage == CHAN_EXTENDED_READ)
1520: FD_CLR(c->efd, readset);
1521: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1522: FD_CLR(c->efd, writeset);
1523: }
1.113 markus 1524: channel_free(c);
1.93 markus 1525: }
1.1 deraadt 1526: }
1527: }
1528:
1.121 markus 1529: /*
1530: * Allocate/update select bitmasks and add any bits relevant to channels in
1531: * select bitmasks.
1532: */
1.49 markus 1533: void
1.100 markus 1534: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1535: int rekeying)
1.41 markus 1536: {
1.84 markus 1537: int n;
1538: u_int sz;
1539:
1540: n = MAX(*maxfdp, channel_max_fd);
1541:
1542: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1543: if (*readsetp == NULL || n > *maxfdp) {
1544: if (*readsetp)
1545: xfree(*readsetp);
1546: if (*writesetp)
1547: xfree(*writesetp);
1548: *readsetp = xmalloc(sz);
1549: *writesetp = xmalloc(sz);
1550: *maxfdp = n;
1551: }
1552: memset(*readsetp, 0, sz);
1553: memset(*writesetp, 0, sz);
1554:
1.100 markus 1555: if (!rekeying)
1556: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1557: }
1558:
1.121 markus 1559: /*
1560: * After select, perform any appropriate operations for channels which have
1561: * events pending.
1562: */
1.49 markus 1563: void
1.41 markus 1564: channel_after_select(fd_set * readset, fd_set * writeset)
1565: {
1566: channel_handler(channel_post, readset, writeset);
1567: }
1568:
1.121 markus 1569:
1.84 markus 1570: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1571:
1.49 markus 1572: void
1.25 markus 1573: channel_output_poll()
1.1 deraadt 1574: {
1.25 markus 1575: int len, i;
1.41 markus 1576: Channel *c;
1.1 deraadt 1577:
1.25 markus 1578: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1579: c = channels[i];
1580: if (c == NULL)
1581: continue;
1.37 markus 1582:
1.121 markus 1583: /*
1584: * We are only interested in channels that can have buffered
1585: * incoming data.
1586: */
1.37 markus 1587: if (compat13) {
1.41 markus 1588: if (c->type != SSH_CHANNEL_OPEN &&
1589: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1590: continue;
1591: } else {
1.41 markus 1592: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1593: continue;
1594: }
1.46 markus 1595: if (compat20 &&
1596: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1597: /* XXX is this true? */
1.97 markus 1598: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1599: continue;
1600: }
1.25 markus 1601:
1602: /* Get the amount of buffered data for this channel. */
1.93 markus 1603: if ((c->istate == CHAN_INPUT_OPEN ||
1604: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1605: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1606: /*
1607: * Send some data for the other side over the secure
1608: * connection.
1609: */
1.44 markus 1610: if (compat20) {
1611: if (len > c->remote_window)
1612: len = c->remote_window;
1613: if (len > c->remote_maxpacket)
1614: len = c->remote_maxpacket;
1.25 markus 1615: } else {
1.44 markus 1616: if (packet_is_interactive()) {
1617: if (len > 1024)
1618: len = 512;
1619: } else {
1620: /* Keep the packets at reasonable size. */
1621: if (len > packet_get_maxsize()/2)
1622: len = packet_get_maxsize()/2;
1623: }
1.25 markus 1624: }
1.41 markus 1625: if (len > 0) {
1.44 markus 1626: packet_start(compat20 ?
1627: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1628: packet_put_int(c->remote_id);
1629: packet_put_string(buffer_ptr(&c->input), len);
1630: packet_send();
1631: buffer_consume(&c->input, len);
1632: c->remote_window -= len;
1633: }
1634: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1635: if (compat13)
1636: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1637: /*
1638: * input-buffer is empty and read-socket shutdown:
1639: * tell peer, that we will not send more data: send IEOF
1640: */
1.41 markus 1641: chan_ibuf_empty(c);
1.25 markus 1642: }
1.44 markus 1643: /* Send extended data, i.e. stderr */
1644: if (compat20 &&
1645: c->remote_window > 0 &&
1646: (len = buffer_len(&c->extended)) > 0 &&
1647: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1648: debug2("channel %d: rwin %d elen %d euse %d",
1649: c->self, c->remote_window, buffer_len(&c->extended),
1650: c->extended_usage);
1.44 markus 1651: if (len > c->remote_window)
1652: len = c->remote_window;
1653: if (len > c->remote_maxpacket)
1654: len = c->remote_maxpacket;
1655: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1656: packet_put_int(c->remote_id);
1657: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1658: packet_put_string(buffer_ptr(&c->extended), len);
1659: packet_send();
1660: buffer_consume(&c->extended, len);
1661: c->remote_window -= len;
1.93 markus 1662: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1663: }
1.25 markus 1664: }
1.1 deraadt 1665: }
1666:
1.121 markus 1667:
1668: /* -- protocol input */
1.1 deraadt 1669:
1.49 markus 1670: void
1.69 markus 1671: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1672: {
1.37 markus 1673: int id;
1.25 markus 1674: char *data;
1.77 markus 1675: u_int data_len;
1.41 markus 1676: Channel *c;
1.25 markus 1677:
1678: /* Get the channel number and verify it. */
1.37 markus 1679: id = packet_get_int();
1.41 markus 1680: c = channel_lookup(id);
1681: if (c == NULL)
1.37 markus 1682: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1683:
1684: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1685: if (c->type != SSH_CHANNEL_OPEN &&
1686: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1687: return;
1688:
1689: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1690: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1691: return;
1692:
1693: /* Get the data. */
1694: data = packet_get_string(&data_len);
1.48 markus 1695: packet_done();
1.41 markus 1696:
1.44 markus 1697: if (compat20){
1698: if (data_len > c->local_maxpacket) {
1699: log("channel %d: rcvd big packet %d, maxpack %d",
1700: c->self, data_len, c->local_maxpacket);
1701: }
1702: if (data_len > c->local_window) {
1703: log("channel %d: rcvd too much data %d, win %d",
1704: c->self, data_len, c->local_window);
1705: xfree(data);
1706: return;
1707: }
1708: c->local_window -= data_len;
1709: }else{
1710: packet_integrity_check(plen, 4 + 4 + data_len, type);
1711: }
1.41 markus 1712: buffer_append(&c->output, data, data_len);
1.25 markus 1713: xfree(data);
1.1 deraadt 1714: }
1.121 markus 1715:
1.49 markus 1716: void
1.69 markus 1717: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1718: {
1719: int id;
1720: int tcode;
1721: char *data;
1.77 markus 1722: u_int data_len;
1.44 markus 1723: Channel *c;
1724:
1725: /* Get the channel number and verify it. */
1726: id = packet_get_int();
1727: c = channel_lookup(id);
1728:
1729: if (c == NULL)
1730: packet_disconnect("Received extended_data for bad channel %d.", id);
1731: if (c->type != SSH_CHANNEL_OPEN) {
1732: log("channel %d: ext data for non open", id);
1733: return;
1734: }
1735: tcode = packet_get_int();
1736: if (c->efd == -1 ||
1737: c->extended_usage != CHAN_EXTENDED_WRITE ||
1738: tcode != SSH2_EXTENDED_DATA_STDERR) {
1739: log("channel %d: bad ext data", c->self);
1740: return;
1741: }
1742: data = packet_get_string(&data_len);
1.48 markus 1743: packet_done();
1.44 markus 1744: if (data_len > c->local_window) {
1745: log("channel %d: rcvd too much extended_data %d, win %d",
1746: c->self, data_len, c->local_window);
1747: xfree(data);
1748: return;
1749: }
1.70 markus 1750: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1751: c->local_window -= data_len;
1752: buffer_append(&c->extended, data, data_len);
1753: xfree(data);
1754: }
1755:
1.49 markus 1756: void
1.69 markus 1757: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1758: {
1759: int id;
1760: Channel *c;
1761:
1762: packet_integrity_check(plen, 4, type);
1763:
1764: id = packet_get_int();
1765: c = channel_lookup(id);
1766: if (c == NULL)
1767: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1768: chan_rcvd_ieof(c);
1769: }
1.1 deraadt 1770:
1.49 markus 1771: void
1.69 markus 1772: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1773: {
1.41 markus 1774: int id;
1775: Channel *c;
1.1 deraadt 1776:
1.41 markus 1777: packet_integrity_check(plen, 4, type);
1778:
1779: id = packet_get_int();
1780: c = channel_lookup(id);
1781: if (c == NULL)
1782: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1783:
1784: /*
1785: * Send a confirmation that we have closed the channel and no more
1786: * data is coming for it.
1787: */
1.25 markus 1788: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1789: packet_put_int(c->remote_id);
1.25 markus 1790: packet_send();
1791:
1.27 markus 1792: /*
1793: * If the channel is in closed state, we have sent a close request,
1794: * and the other side will eventually respond with a confirmation.
1795: * Thus, we cannot free the channel here, because then there would be
1796: * no-one to receive the confirmation. The channel gets freed when
1797: * the confirmation arrives.
1798: */
1.41 markus 1799: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1800: /*
1801: * Not a closed channel - mark it as draining, which will
1802: * cause it to be freed later.
1803: */
1.41 markus 1804: buffer_consume(&c->input, buffer_len(&c->input));
1805: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1806: }
1.1 deraadt 1807: }
1808:
1.41 markus 1809: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1810: void
1.69 markus 1811: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1812: {
1813: int id = packet_get_int();
1814: Channel *c = channel_lookup(id);
1815: packet_integrity_check(plen, 4, type);
1816: if (c == NULL)
1817: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1818: chan_rcvd_oclose(c);
1819: }
1.1 deraadt 1820:
1.49 markus 1821: void
1.69 markus 1822: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1823: {
1.41 markus 1824: int id = packet_get_int();
1825: Channel *c = channel_lookup(id);
1.1 deraadt 1826:
1.48 markus 1827: packet_done();
1.41 markus 1828: if (c == NULL)
1829: packet_disconnect("Received close confirmation for "
1830: "out-of-range channel %d.", id);
1831: if (c->type != SSH_CHANNEL_CLOSED)
1832: packet_disconnect("Received close confirmation for "
1833: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1834: channel_free(c);
1.1 deraadt 1835: }
1836:
1.49 markus 1837: void
1.69 markus 1838: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1839: {
1.41 markus 1840: int id, remote_id;
1841: Channel *c;
1.1 deraadt 1842:
1.44 markus 1843: if (!compat20)
1844: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1845:
1.41 markus 1846: id = packet_get_int();
1847: c = channel_lookup(id);
1.25 markus 1848:
1.41 markus 1849: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1850: packet_disconnect("Received open confirmation for "
1851: "non-opening channel %d.", id);
1852: remote_id = packet_get_int();
1.27 markus 1853: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1854: c->remote_id = remote_id;
1855: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1856:
1857: if (compat20) {
1858: c->remote_window = packet_get_int();
1859: c->remote_maxpacket = packet_get_int();
1.48 markus 1860: packet_done();
1.44 markus 1861: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1862: debug2("callback start");
1.44 markus 1863: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1864: debug2("callback done");
1.44 markus 1865: }
1866: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1867: c->remote_window, c->remote_maxpacket);
1868: }
1.1 deraadt 1869: }
1870:
1.127 itojun 1871: static char *
1.114 markus 1872: reason2txt(int reason)
1873: {
1874: switch(reason) {
1875: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1876: return "administratively prohibited";
1877: case SSH2_OPEN_CONNECT_FAILED:
1878: return "connect failed";
1879: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1880: return "unknown channel type";
1881: case SSH2_OPEN_RESOURCE_SHORTAGE:
1882: return "resource shortage";
1883: }
1.117 stevesk 1884: return "unknown reason";
1.114 markus 1885: }
1886:
1.49 markus 1887: void
1.69 markus 1888: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1889: {
1.86 markus 1890: int id, reason;
1891: char *msg = NULL, *lang = NULL;
1.41 markus 1892: Channel *c;
1893:
1.44 markus 1894: if (!compat20)
1895: packet_integrity_check(plen, 4, type);
1.41 markus 1896:
1897: id = packet_get_int();
1898: c = channel_lookup(id);
1.25 markus 1899:
1.41 markus 1900: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1901: packet_disconnect("Received open failure for "
1902: "non-opening channel %d.", id);
1.44 markus 1903: if (compat20) {
1.86 markus 1904: reason = packet_get_int();
1.110 markus 1905: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1906: msg = packet_get_string(NULL);
1907: lang = packet_get_string(NULL);
1908: }
1.48 markus 1909: packet_done();
1.114 markus 1910: log("channel %d: open failed: %s%s%s", id,
1911: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1912: if (msg != NULL)
1913: xfree(msg);
1914: if (lang != NULL)
1915: xfree(lang);
1.44 markus 1916: }
1.25 markus 1917: /* Free the channel. This will also close the socket. */
1.113 markus 1918: channel_free(c);
1.1 deraadt 1919: }
1920:
1.44 markus 1921: void
1.69 markus 1922: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1923: {
1924: int id;
1925: Channel *c;
1926:
1927: id = packet_get_int();
1928: c = channel_lookup(id);
1929:
1930: if (c == NULL ||
1931: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1932: packet_disconnect("Received request for "
1933: "non-open channel %d.", id);
1934: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1935: debug2("callback start");
1.44 markus 1936: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1937: debug2("callback done");
1.44 markus 1938: } else {
1939: char *service = packet_get_string(NULL);
1.94 markus 1940: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1941: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1942: xfree(service);
1943: }
1944: }
1945:
1.121 markus 1946: void
1947: channel_input_window_adjust(int type, int plen, void *ctxt)
1948: {
1949: Channel *c;
1950: int id, adjust;
1951:
1952: if (!compat20)
1953: return;
1954:
1955: /* Get the channel number and verify it. */
1956: id = packet_get_int();
1957: c = channel_lookup(id);
1.1 deraadt 1958:
1.121 markus 1959: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1960: log("Received window adjust for "
1961: "non-open channel %d.", id);
1962: return;
1963: }
1964: adjust = packet_get_int();
1965: packet_done();
1966: debug2("channel %d: rcvd adjust %d", id, adjust);
1967: c->remote_window += adjust;
1968: }
1.1 deraadt 1969:
1.121 markus 1970: void
1971: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1972: {
1.121 markus 1973: Channel *c = NULL;
1974: u_short host_port;
1975: char *host, *originator_string;
1976: int remote_id, sock = -1;
1977:
1978: remote_id = packet_get_int();
1979: host = packet_get_string(NULL);
1980: host_port = packet_get_int();
1.25 markus 1981:
1.121 markus 1982: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1983: originator_string = packet_get_string(NULL);
1984: } else {
1985: originator_string = xstrdup("unknown (remote did not supply name)");
1986: }
1987: packet_done();
1988: sock = channel_connect_to(host, host_port);
1989: if (sock != -1) {
1990: c = channel_new("connected socket",
1991: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1992: originator_string, 1);
1993: if (c == NULL) {
1994: error("channel_input_port_open: channel_new failed");
1995: close(sock);
1996: } else {
1997: c->remote_id = remote_id;
1.25 markus 1998: }
1999: }
1.121 markus 2000: if (c == NULL) {
2001: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2002: packet_put_int(remote_id);
2003: packet_send();
2004: }
2005: xfree(host);
1.1 deraadt 2006: }
2007:
1.121 markus 2008:
2009: /* -- tcp forwarding */
2010:
1.27 markus 2011: /*
2012: * Initiate forwarding of connections to local port "port" through the secure
2013: * channel to host:port from remote side.
2014: */
1.87 markus 2015: int
1.73 markus 2016: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
2017: u_short port_to_connect, int gateway_ports)
2018: {
1.87 markus 2019: return channel_request_forwarding(
1.73 markus 2020: NULL, listen_port,
2021: host_to_connect, port_to_connect,
2022: gateway_ports, /*remote_fwd*/ 0);
2023: }
1.1 deraadt 2024:
1.73 markus 2025: /*
2026: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
2027: * (SSH_CHANNEL_RPORT_LISTENER).
2028: */
1.87 markus 2029: int
1.73 markus 2030: channel_request_forwarding(
2031: const char *listen_address, u_short listen_port,
2032: const char *host_to_connect, u_short port_to_connect,
2033: int gateway_ports, int remote_fwd)
1.25 markus 2034: {
1.113 markus 2035: Channel *c;
1.121 markus 2036: int success, sock, on = 1, type;
1.35 markus 2037: struct addrinfo hints, *ai, *aitop;
2038: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 2039: const char *host;
1.28 markus 2040: struct linger linger;
1.25 markus 2041:
1.87 markus 2042: success = 0;
2043:
1.73 markus 2044: if (remote_fwd) {
2045: host = listen_address;
1.121 markus 2046: type = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 2047: } else {
2048: host = host_to_connect;
1.121 markus 2049: type = SSH_CHANNEL_PORT_LISTENER;
1.73 markus 2050: }
2051:
1.113 markus 2052: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2053: error("Forward host name too long.");
2054: return success;
2055: }
1.25 markus 2056:
1.73 markus 2057: /* XXX listen_address is currently ignored */
1.28 markus 2058: /*
1.35 markus 2059: * getaddrinfo returns a loopback address if the hostname is
2060: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2061: */
1.35 markus 2062: memset(&hints, 0, sizeof(hints));
2063: hints.ai_family = IPv4or6;
2064: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2065: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2066: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2067: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2068: packet_disconnect("getaddrinfo: fatal error");
2069:
2070: for (ai = aitop; ai; ai = ai->ai_next) {
2071: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2072: continue;
2073: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2074: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 2075: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 2076: continue;
2077: }
2078: /* Create a port to listen for the host. */
2079: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2080: if (sock < 0) {
2081: /* this is no error since kernel may not support ipv6 */
2082: verbose("socket: %.100s", strerror(errno));
2083: continue;
2084: }
2085: /*
2086: * Set socket options. We would like the socket to disappear
2087: * as soon as it has been closed for whatever reason.
2088: */
2089: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2090: linger.l_onoff = 1;
2091: linger.l_linger = 5;
2092: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2093: debug("Local forwarding listening on %s port %s.", ntop, strport);
2094:
2095: /* Bind the socket to the address. */
2096: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2097: /* address can be in use ipv6 address is already bound */
2098: verbose("bind: %.100s", strerror(errno));
2099: close(sock);
2100: continue;
2101: }
2102: /* Start listening for connections on the socket. */
2103: if (listen(sock, 5) < 0) {
2104: error("listen: %.100s", strerror(errno));
2105: close(sock);
2106: continue;
2107: }
2108: /* Allocate a channel number for the socket. */
1.121 markus 2109: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2110: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2111: 0, xstrdup("port listener"), 1);
1.113 markus 2112: if (c == NULL) {
2113: error("channel_request_forwarding: channel_new failed");
2114: close(sock);
2115: continue;
2116: }
2117: strlcpy(c->path, host, sizeof(c->path));
2118: c->host_port = port_to_connect;
2119: c->listening_port = listen_port;
1.35 markus 2120: success = 1;
2121: }
2122: if (success == 0)
1.87 markus 2123: error("channel_request_forwarding: cannot listen to port: %d",
2124: listen_port);
1.35 markus 2125: freeaddrinfo(aitop);
1.87 markus 2126: return success;
1.25 markus 2127: }
1.1 deraadt 2128:
1.27 markus 2129: /*
2130: * Initiate forwarding of connections to port "port" on remote host through
2131: * the secure channel to host:port from local side.
2132: */
1.1 deraadt 2133:
1.49 markus 2134: void
1.73 markus 2135: channel_request_remote_forwarding(u_short listen_port,
2136: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2137: {
1.73 markus 2138: int payload_len, type, success = 0;
2139:
1.25 markus 2140: /* Record locally that connection to this host/port is permitted. */
2141: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2142: fatal("channel_request_remote_forwarding: too many forwards");
2143:
2144: /* Send the forward request to the remote side. */
1.44 markus 2145: if (compat20) {
2146: const char *address_to_bind = "0.0.0.0";
2147: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2148: packet_put_cstring("tcpip-forward");
2149: packet_put_char(0); /* boolean: want reply */
2150: packet_put_cstring(address_to_bind);
2151: packet_put_int(listen_port);
1.73 markus 2152: packet_send();
2153: packet_write_wait();
2154: /* Assume that server accepts the request */
2155: success = 1;
1.44 markus 2156: } else {
2157: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2158: packet_put_int(listen_port);
2159: packet_put_cstring(host_to_connect);
1.44 markus 2160: packet_put_int(port_to_connect);
2161: packet_send();
2162: packet_write_wait();
1.73 markus 2163:
2164: /* Wait for response from the remote side. */
2165: type = packet_read(&payload_len);
2166: switch (type) {
2167: case SSH_SMSG_SUCCESS:
2168: success = 1;
2169: break;
2170: case SSH_SMSG_FAILURE:
2171: log("Warning: Server denied remote port forwarding.");
2172: break;
2173: default:
2174: /* Unknown packet */
2175: packet_disconnect("Protocol error for port forward request:"
2176: "received packet type %d.", type);
2177: }
2178: }
2179: if (success) {
2180: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2181: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2182: permitted_opens[num_permitted_opens].listen_port = listen_port;
2183: num_permitted_opens++;
1.44 markus 2184: }
1.1 deraadt 2185: }
2186:
1.27 markus 2187: /*
2188: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2189: * listening for the port, and sends back a success reply (or disconnect
2190: * message if there was an error). This never returns if there was an error.
2191: */
1.1 deraadt 2192:
1.49 markus 2193: void
1.56 markus 2194: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2195: {
1.31 markus 2196: u_short port, host_port;
1.25 markus 2197: char *hostname;
1.1 deraadt 2198:
1.25 markus 2199: /* Get arguments from the packet. */
2200: port = packet_get_int();
2201: hostname = packet_get_string(NULL);
2202: host_port = packet_get_int();
2203:
1.27 markus 2204: /*
2205: * Check that an unprivileged user is not trying to forward a
2206: * privileged port.
2207: */
1.25 markus 2208: if (port < IPPORT_RESERVED && !is_root)
2209: packet_disconnect("Requested forwarding of port %d but user is not root.",
2210: port);
1.73 markus 2211: /* Initiate forwarding */
1.56 markus 2212: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2213:
2214: /* Free the argument string. */
2215: xfree(hostname);
1.1 deraadt 2216: }
2217:
1.99 markus 2218: /*
2219: * Permits opening to any host/port if permitted_opens[] is empty. This is
2220: * usually called by the server, because the user could connect to any port
2221: * anyway, and the server has no way to know but to trust the client anyway.
2222: */
2223: void
2224: channel_permit_all_opens()
2225: {
2226: if (num_permitted_opens == 0)
2227: all_opens_permitted = 1;
2228: }
2229:
1.101 markus 2230: void
1.99 markus 2231: channel_add_permitted_opens(char *host, int port)
2232: {
2233: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2234: fatal("channel_request_remote_forwarding: too many forwards");
2235: debug("allow port forwarding to host %s port %d", host, port);
2236:
2237: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2238: permitted_opens[num_permitted_opens].port_to_connect = port;
2239: num_permitted_opens++;
2240:
2241: all_opens_permitted = 0;
2242: }
2243:
1.101 markus 2244: void
1.99 markus 2245: channel_clear_permitted_opens(void)
2246: {
2247: int i;
2248:
2249: for (i = 0; i < num_permitted_opens; i++)
2250: xfree(permitted_opens[i].host_to_connect);
2251: num_permitted_opens = 0;
2252:
2253: }
2254:
2255:
2256: /* return socket to remote host, port */
1.127 itojun 2257: static int
1.99 markus 2258: connect_to(const char *host, u_short port)
1.41 markus 2259: {
2260: struct addrinfo hints, *ai, *aitop;
2261: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2262: int gaierr;
2263: int sock = -1;
2264:
2265: memset(&hints, 0, sizeof(hints));
2266: hints.ai_family = IPv4or6;
2267: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2268: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2269: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2270: error("connect_to %.100s: unknown host (%s)", host,
2271: gai_strerror(gaierr));
1.41 markus 2272: return -1;
2273: }
2274: for (ai = aitop; ai; ai = ai->ai_next) {
2275: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2276: continue;
2277: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2278: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2279: error("connect_to: getnameinfo failed");
1.41 markus 2280: continue;
2281: }
2282: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2283: if (sock < 0) {
2284: error("socket: %.100s", strerror(errno));
2285: continue;
2286: }
1.80 markus 2287: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2288: fatal("connect_to: F_SETFL: %s", strerror(errno));
2289: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2290: errno != EINPROGRESS) {
1.99 markus 2291: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2292: strerror(errno));
2293: close(sock);
1.89 stevesk 2294: continue; /* fail -- try next */
1.41 markus 2295: }
2296: break; /* success */
2297:
2298: }
2299: freeaddrinfo(aitop);
2300: if (!ai) {
1.99 markus 2301: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2302: return -1;
2303: }
2304: /* success */
2305: return sock;
2306: }
1.99 markus 2307:
1.73 markus 2308: int
1.130 stevesk 2309: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2310: {
2311: int i;
1.99 markus 2312:
1.73 markus 2313: for (i = 0; i < num_permitted_opens; i++)
2314: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2315: return connect_to(
1.73 markus 2316: permitted_opens[i].host_to_connect,
2317: permitted_opens[i].port_to_connect);
1.74 markus 2318: error("WARNING: Server requests forwarding for unknown listen_port %d",
2319: listen_port);
1.73 markus 2320: return -1;
2321: }
2322:
1.99 markus 2323: /* Check if connecting to that port is permitted and connect. */
2324: int
2325: channel_connect_to(const char *host, u_short port)
2326: {
2327: int i, permit;
2328:
2329: permit = all_opens_permitted;
2330: if (!permit) {
2331: for (i = 0; i < num_permitted_opens; i++)
2332: if (permitted_opens[i].port_to_connect == port &&
2333: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2334: permit = 1;
2335:
2336: }
2337: if (!permit) {
2338: log("Received request to connect to host %.100s port %d, "
2339: "but the request was denied.", host, port);
2340: return -1;
2341: }
2342: return connect_to(host, port);
2343: }
2344:
1.121 markus 2345: /* -- X11 forwarding */
1.1 deraadt 2346:
1.27 markus 2347: /*
2348: * Creates an internet domain socket for listening for X11 connections.
2349: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2350: * occurs.
2351: */
1.25 markus 2352: char *
1.33 markus 2353: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2354: {
1.31 markus 2355: int display_number, sock;
2356: u_short port;
1.35 markus 2357: struct addrinfo hints, *ai, *aitop;
2358: char strport[NI_MAXSERV];
2359: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2360: char display[512];
1.25 markus 2361: char hostname[MAXHOSTNAMELEN];
2362:
1.33 markus 2363: for (display_number = x11_display_offset;
1.25 markus 2364: display_number < MAX_DISPLAYS;
2365: display_number++) {
2366: port = 6000 + display_number;
1.35 markus 2367: memset(&hints, 0, sizeof(hints));
2368: hints.ai_family = IPv4or6;
1.36 markus 2369: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2370: hints.ai_socktype = SOCK_STREAM;
2371: snprintf(strport, sizeof strport, "%d", port);
2372: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2373: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2374: return NULL;
2375: }
1.35 markus 2376: for (ai = aitop; ai; ai = ai->ai_next) {
2377: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2378: continue;
2379: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2380: if (sock < 0) {
2381: error("socket: %.100s", strerror(errno));
2382: return NULL;
2383: }
2384: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2385: debug("bind port %d: %.100s", port, strerror(errno));
2386: shutdown(sock, SHUT_RDWR);
2387: close(sock);
2388: for (n = 0; n < num_socks; n++) {
2389: shutdown(socks[n], SHUT_RDWR);
2390: close(socks[n]);
2391: }
2392: num_socks = 0;
2393: break;
2394: }
2395: socks[num_socks++] = sock;
2396: if (num_socks == NUM_SOCKS)
2397: break;
1.25 markus 2398: }
1.83 stevesk 2399: freeaddrinfo(aitop);
1.35 markus 2400: if (num_socks > 0)
2401: break;
1.25 markus 2402: }
2403: if (display_number >= MAX_DISPLAYS) {
2404: error("Failed to allocate internet-domain X11 display socket.");
2405: return NULL;
2406: }
2407: /* Start listening for connections on the socket. */
1.35 markus 2408: for (n = 0; n < num_socks; n++) {
2409: sock = socks[n];
2410: if (listen(sock, 5) < 0) {
2411: error("listen: %.100s", strerror(errno));
2412: shutdown(sock, SHUT_RDWR);
2413: close(sock);
2414: return NULL;
2415: }
1.25 markus 2416: }
1.35 markus 2417:
1.25 markus 2418: /* Set up a suitable value for the DISPLAY variable. */
2419: if (gethostname(hostname, sizeof(hostname)) < 0)
2420: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2421: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2422: display_number, screen_number);
2423:
1.35 markus 2424: /* Allocate a channel for each socket. */
2425: for (n = 0; n < num_socks; n++) {
2426: sock = socks[n];
1.51 markus 2427: (void) channel_new("x11 listener",
2428: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2429: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2430: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2431: }
1.1 deraadt 2432:
1.25 markus 2433: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2434: return xstrdup(display);
1.1 deraadt 2435: }
2436:
2437: #ifndef X_UNIX_PATH
2438: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2439: #endif
2440:
1.127 itojun 2441: static int
1.77 markus 2442: connect_local_xsocket(u_int dnr)
1.1 deraadt 2443: {
1.25 markus 2444: static const char *const x_sockets[] = {
2445: X_UNIX_PATH "%u",
2446: "/var/X/.X11-unix/X" "%u",
2447: "/usr/spool/sockets/X11/" "%u",
2448: NULL
2449: };
2450: int sock;
2451: struct sockaddr_un addr;
2452: const char *const * path;
2453:
2454: for (path = x_sockets; *path; ++path) {
2455: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2456: if (sock < 0)
2457: error("socket: %.100s", strerror(errno));
2458: memset(&addr, 0, sizeof(addr));
2459: addr.sun_family = AF_UNIX;
2460: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2461: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2462: return sock;
2463: close(sock);
2464: }
2465: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2466: return -1;
1.1 deraadt 2467: }
2468:
1.51 markus 2469: int
2470: x11_connect_display(void)
1.1 deraadt 2471: {
1.51 markus 2472: int display_number, sock = 0;
1.25 markus 2473: const char *display;
1.51 markus 2474: char buf[1024], *cp;
1.35 markus 2475: struct addrinfo hints, *ai, *aitop;
2476: char strport[NI_MAXSERV];
2477: int gaierr;
1.25 markus 2478:
2479: /* Try to open a socket for the local X server. */
2480: display = getenv("DISPLAY");
2481: if (!display) {
2482: error("DISPLAY not set.");
1.51 markus 2483: return -1;
1.25 markus 2484: }
1.27 markus 2485: /*
2486: * Now we decode the value of the DISPLAY variable and make a
2487: * connection to the real X server.
2488: */
2489:
2490: /*
2491: * Check if it is a unix domain socket. Unix domain displays are in
2492: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2493: */
1.25 markus 2494: if (strncmp(display, "unix:", 5) == 0 ||
2495: display[0] == ':') {
2496: /* Connect to the unix domain socket. */
2497: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2498: error("Could not parse display number from DISPLAY: %.100s",
2499: display);
1.51 markus 2500: return -1;
1.25 markus 2501: }
2502: /* Create a socket. */
2503: sock = connect_local_xsocket(display_number);
2504: if (sock < 0)
1.51 markus 2505: return -1;
1.25 markus 2506:
2507: /* OK, we now have a connection to the display. */
1.51 markus 2508: return sock;
1.25 markus 2509: }
1.27 markus 2510: /*
2511: * Connect to an inet socket. The DISPLAY value is supposedly
2512: * hostname:d[.s], where hostname may also be numeric IP address.
2513: */
1.25 markus 2514: strncpy(buf, display, sizeof(buf));
2515: buf[sizeof(buf) - 1] = 0;
2516: cp = strchr(buf, ':');
2517: if (!cp) {
2518: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2519: return -1;
1.25 markus 2520: }
2521: *cp = 0;
1.27 markus 2522: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2523: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2524: error("Could not parse display number from DISPLAY: %.100s",
2525: display);
1.51 markus 2526: return -1;
1.25 markus 2527: }
1.35 markus 2528:
2529: /* Look up the host address */
2530: memset(&hints, 0, sizeof(hints));
2531: hints.ai_family = IPv4or6;
2532: hints.ai_socktype = SOCK_STREAM;
2533: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2534: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2535: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2536: return -1;
1.25 markus 2537: }
1.35 markus 2538: for (ai = aitop; ai; ai = ai->ai_next) {
2539: /* Create a socket. */
2540: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2541: if (sock < 0) {
2542: debug("socket: %.100s", strerror(errno));
1.41 markus 2543: continue;
2544: }
2545: /* Connect it to the display. */
2546: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2547: debug("connect %.100s port %d: %.100s", buf,
2548: 6000 + display_number, strerror(errno));
2549: close(sock);
2550: continue;
2551: }
2552: /* Success */
2553: break;
1.35 markus 2554: }
2555: freeaddrinfo(aitop);
2556: if (!ai) {
1.49 markus 2557: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2558: strerror(errno));
1.51 markus 2559: return -1;
1.25 markus 2560: }
1.51 markus 2561: return sock;
2562: }
2563:
2564: /*
2565: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2566: * the remote channel number. We should do whatever we want, and respond
2567: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2568: */
2569:
2570: void
1.69 markus 2571: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2572: {
1.113 markus 2573: Channel *c = NULL;
2574: int remote_id, sock = 0;
1.51 markus 2575: char *remote_host;
1.25 markus 2576:
1.113 markus 2577: debug("Received X11 open request.");
1.51 markus 2578:
1.113 markus 2579: remote_id = packet_get_int();
1.121 markus 2580:
2581: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2582: remote_host = packet_get_string(NULL);
1.51 markus 2583: } else {
2584: remote_host = xstrdup("unknown (remote did not supply name)");
2585: }
1.113 markus 2586: packet_done();
1.25 markus 2587:
1.51 markus 2588: /* Obtain a connection to the real X display. */
2589: sock = x11_connect_display();
1.113 markus 2590: if (sock != -1) {
2591: /* Allocate a channel for this connection. */
2592: c = channel_new("connected x11 socket",
2593: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2594: remote_host, 1);
2595: if (c == NULL) {
2596: error("x11_input_open: channel_new failed");
2597: close(sock);
2598: } else {
2599: c->remote_id = remote_id;
2600: }
2601: }
2602: if (c == NULL) {
1.51 markus 2603: /* Send refusal to the remote host. */
2604: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2605: packet_put_int(remote_id);
1.51 markus 2606: } else {
2607: /* Send a confirmation to the remote host. */
2608: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2609: packet_put_int(remote_id);
2610: packet_put_int(c->self);
1.51 markus 2611: }
1.113 markus 2612: packet_send();
1.72 markus 2613: }
2614:
2615: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2616: void
2617: deny_input_open(int type, int plen, void *ctxt)
2618: {
2619: int rchan = packet_get_int();
2620: switch(type){
2621: case SSH_SMSG_AGENT_OPEN:
2622: error("Warning: ssh server tried agent forwarding.");
2623: break;
2624: case SSH_SMSG_X11_OPEN:
2625: error("Warning: ssh server tried X11 forwarding.");
2626: break;
2627: default:
2628: error("deny_input_open: type %d plen %d", type, plen);
2629: break;
2630: }
2631: error("Warning: this is probably a break in attempt by a malicious server.");
2632: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2633: packet_put_int(rchan);
2634: packet_send();
1.1 deraadt 2635: }
2636:
1.27 markus 2637: /*
2638: * Requests forwarding of X11 connections, generates fake authentication
2639: * data, and enables authentication spoofing.
1.121 markus 2640: * This should be called in the client only.
1.27 markus 2641: */
1.49 markus 2642: void
1.51 markus 2643: x11_request_forwarding_with_spoofing(int client_session_id,
2644: const char *proto, const char *data)
1.1 deraadt 2645: {
1.77 markus 2646: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2647: u_int i, value, len;
1.25 markus 2648: char *new_data;
2649: int screen_number;
2650: const char *cp;
2651: u_int32_t rand = 0;
2652:
2653: cp = getenv("DISPLAY");
2654: if (cp)
2655: cp = strchr(cp, ':');
2656: if (cp)
2657: cp = strchr(cp, '.');
2658: if (cp)
2659: screen_number = atoi(cp + 1);
2660: else
2661: screen_number = 0;
2662:
2663: /* Save protocol name. */
2664: x11_saved_proto = xstrdup(proto);
2665:
1.27 markus 2666: /*
2667: * Extract real authentication data and generate fake data of the
2668: * same length.
2669: */
1.25 markus 2670: x11_saved_data = xmalloc(data_len);
2671: x11_fake_data = xmalloc(data_len);
2672: for (i = 0; i < data_len; i++) {
2673: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2674: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2675: if (i % 4 == 0)
2676: rand = arc4random();
2677: x11_saved_data[i] = value;
2678: x11_fake_data[i] = rand & 0xff;
2679: rand >>= 8;
2680: }
2681: x11_saved_data_len = data_len;
2682: x11_fake_data_len = data_len;
2683:
2684: /* Convert the fake data into hex. */
1.90 markus 2685: len = 2 * data_len + 1;
2686: new_data = xmalloc(len);
1.25 markus 2687: for (i = 0; i < data_len; i++)
1.90 markus 2688: snprintf(new_data + 2 * i, len - 2 * i,
2689: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2690:
2691: /* Send the request packet. */
1.51 markus 2692: if (compat20) {
2693: channel_request_start(client_session_id, "x11-req", 0);
2694: packet_put_char(0); /* XXX bool single connection */
2695: } else {
2696: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2697: }
2698: packet_put_cstring(proto);
2699: packet_put_cstring(new_data);
1.25 markus 2700: packet_put_int(screen_number);
2701: packet_send();
2702: packet_write_wait();
2703: xfree(new_data);
1.1 deraadt 2704: }
2705:
1.121 markus 2706:
2707: /* -- agent forwarding */
2708:
1.1 deraadt 2709: /* Sends a message to the server to request authentication fd forwarding. */
2710:
1.49 markus 2711: void
1.25 markus 2712: auth_request_forwarding()
1.1 deraadt 2713: {
1.25 markus 2714: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2715: packet_send();
2716: packet_write_wait();
1.1 deraadt 2717: }
2718:
1.27 markus 2719: /*
2720: * Returns the name of the forwarded authentication socket. Returns NULL if
2721: * there is no forwarded authentication socket. The returned value points to
2722: * a static buffer.
2723: */
1.1 deraadt 2724:
1.25 markus 2725: char *
2726: auth_get_socket_name()
1.1 deraadt 2727: {
1.121 markus 2728: return auth_sock_name;
1.1 deraadt 2729: }
2730:
1.12 markus 2731: /* removes the agent forwarding socket */
2732:
1.49 markus 2733: void
1.123 markus 2734: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2735: {
1.123 markus 2736: struct passwd *pw = _pw;
2737:
1.122 markus 2738: if (auth_sock_name) {
1.123 markus 2739: temporarily_use_uid(pw);
1.122 markus 2740: unlink(auth_sock_name);
2741: rmdir(auth_sock_dir);
2742: auth_sock_name = NULL;
1.123 markus 2743: restore_uid();
1.122 markus 2744: }
1.12 markus 2745: }
2746:
1.27 markus 2747: /*
1.59 markus 2748: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2749: * This starts forwarding authentication requests.
2750: */
1.1 deraadt 2751:
1.59 markus 2752: int
1.25 markus 2753: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2754: {
1.113 markus 2755: Channel *nc;
2756: int sock;
1.25 markus 2757: struct sockaddr_un sunaddr;
2758:
1.121 markus 2759: if (auth_get_socket_name() != NULL) {
2760: error("authentication forwarding requested twice.");
2761: return 0;
2762: }
1.25 markus 2763:
2764: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2765: temporarily_use_uid(pw);
1.25 markus 2766:
2767: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2768: auth_sock_name = xmalloc(MAXPATHLEN);
2769: auth_sock_dir = xmalloc(MAXPATHLEN);
2770: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2771:
2772: /* Create private directory for socket */
1.121 markus 2773: if (mkdtemp(auth_sock_dir) == NULL) {
2774: packet_send_debug("Agent forwarding disabled: "
2775: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2776: restore_uid();
1.121 markus 2777: xfree(auth_sock_name);
2778: xfree(auth_sock_dir);
2779: auth_sock_name = NULL;
2780: auth_sock_dir = NULL;
1.59 markus 2781: return 0;
2782: }
1.121 markus 2783: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2784: auth_sock_dir, (int) getpid());
1.25 markus 2785:
1.122 markus 2786: /* delete agent socket on fatal() */
1.123 markus 2787: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2788:
1.25 markus 2789: /* Create the socket. */
2790: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2791: if (sock < 0)
2792: packet_disconnect("socket: %.100s", strerror(errno));
2793:
2794: /* Bind it to the name. */
2795: memset(&sunaddr, 0, sizeof(sunaddr));
2796: sunaddr.sun_family = AF_UNIX;
1.121 markus 2797: strncpy(sunaddr.sun_path, auth_sock_name,
1.25 markus 2798: sizeof(sunaddr.sun_path));
2799:
2800: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2801: packet_disconnect("bind: %.100s", strerror(errno));
2802:
2803: /* Restore the privileged uid. */
2804: restore_uid();
2805:
2806: /* Start listening on the socket. */
2807: if (listen(sock, 5) < 0)
2808: packet_disconnect("listen: %.100s", strerror(errno));
2809:
2810: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2811: nc = channel_new("auth socket",
1.73 markus 2812: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2813: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2814: 0, xstrdup("auth socket"), 1);
1.113 markus 2815: if (nc == NULL) {
2816: error("auth_input_request_forwarding: channel_new failed");
1.123 markus 2817: auth_sock_cleanup_proc(pw);
1.124 markus 2818: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
1.113 markus 2819: close(sock);
2820: return 0;
2821: }
1.121 markus 2822: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2823: return 1;
1.1 deraadt 2824: }
2825:
2826: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2827:
1.49 markus 2828: void
1.69 markus 2829: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2830: {
1.113 markus 2831: Channel *c = NULL;
2832: int remote_id, sock;
1.121 markus 2833: char *name;
1.41 markus 2834:
2835: packet_integrity_check(plen, 4, type);
1.25 markus 2836:
2837: /* Read the remote channel number from the message. */
1.113 markus 2838: remote_id = packet_get_int();
1.25 markus 2839:
1.27 markus 2840: /*
2841: * Get a connection to the local authentication agent (this may again
2842: * get forwarded).
2843: */
1.25 markus 2844: sock = ssh_get_authentication_socket();
2845:
1.27 markus 2846: /*
2847: * If we could not connect the agent, send an error message back to
2848: * the server. This should never happen unless the agent dies,
2849: * because authentication forwarding is only enabled if we have an
2850: * agent.
2851: */
1.113 markus 2852: if (sock >= 0) {
1.121 markus 2853: name = xstrdup("authentication agent connection");
2854: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2855: -1, 0, 0, 0, name, 1);
1.113 markus 2856: if (c == NULL) {
2857: error("auth_input_open_request: channel_new failed");
1.121 markus 2858: xfree(name);
1.113 markus 2859: close(sock);
2860: } else {
2861: c->remote_id = remote_id;
2862: }
2863: }
2864: if (c == NULL) {
1.25 markus 2865: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2866: packet_put_int(remote_id);
2867: } else {
2868: /* Send a confirmation to the remote host. */
2869: debug("Forwarding authentication connection.");
2870: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2871: packet_put_int(remote_id);
2872: packet_put_int(c->self);
1.25 markus 2873: }
2874: packet_send();
1.1 deraadt 2875: }
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