Annotation of src/usr.bin/ssh/channels.c, Revision 1.168
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.156 markus 16: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.168 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.167 2002/02/06 14:55:15 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
49: #include "uidswap.h"
1.82 markus 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.82 markus 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.147 stevesk 57: #include "pathnames.h"
1.44 markus 58:
1.1 deraadt 59:
1.121 markus 60: /* -- channel core */
1.12 markus 61:
1.27 markus 62: /*
63: * Pointer to an array containing all allocated channels. The array is
64: * dynamically extended as needed.
65: */
1.113 markus 66: static Channel **channels = NULL;
1.1 deraadt 67:
1.27 markus 68: /*
69: * Size of the channel array. All slots of the array must always be
1.113 markus 70: * initialized (at least the type field); unused slots set to NULL
1.27 markus 71: */
1.1 deraadt 72: static int channels_alloc = 0;
73:
1.27 markus 74: /*
75: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 76: * updated in channel_new.
1.27 markus 77: */
1.84 markus 78: static int channel_max_fd = 0;
1.1 deraadt 79:
80:
1.121 markus 81: /* -- tcp forwarding */
1.1 deraadt 82:
1.27 markus 83: /*
84: * Data structure for storing which hosts are permitted for forward requests.
85: * The local sides of any remote forwards are stored in this array to prevent
86: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
87: * network (which might be behind a firewall).
88: */
1.25 markus 89: typedef struct {
1.41 markus 90: char *host_to_connect; /* Connect to 'host'. */
91: u_short port_to_connect; /* Connect to 'port'. */
92: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 93: } ForwardPermission;
94:
95: /* List of all permitted host/port pairs to connect. */
96: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 97:
1.1 deraadt 98: /* Number of permitted host/port pairs in the array. */
99: static int num_permitted_opens = 0;
1.27 markus 100: /*
101: * If this is true, all opens are permitted. This is the case on the server
102: * on which we have to trust the client anyway, and the user could do
103: * anything after logging in anyway.
104: */
1.1 deraadt 105: static int all_opens_permitted = 0;
106:
1.121 markus 107:
108: /* -- X11 forwarding */
109:
110: /* Maximum number of fake X11 displays to try. */
111: #define MAX_DISPLAYS 1000
112:
113: /* Saved X11 authentication protocol name. */
114: static char *x11_saved_proto = NULL;
115:
116: /* Saved X11 authentication data. This is the real data. */
117: static char *x11_saved_data = NULL;
118: static u_int x11_saved_data_len = 0;
119:
120: /*
121: * Fake X11 authentication data. This is what the server will be sending us;
122: * we should replace any occurrences of this by the real data.
123: */
124: static char *x11_fake_data = NULL;
125: static u_int x11_fake_data_len;
126:
127:
128: /* -- agent forwarding */
129:
130: #define NUM_SOCKS 10
131:
132: /* Name and directory of socket for authentication agent forwarding. */
133: static char *auth_sock_name = NULL;
134: static char *auth_sock_dir = NULL;
135:
1.82 markus 136: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 137: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 138:
1.121 markus 139: /* helper */
1.127 itojun 140: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 141:
1.121 markus 142: /* -- channel core */
1.41 markus 143:
144: Channel *
145: channel_lookup(int id)
146: {
147: Channel *c;
1.113 markus 148:
1.63 provos 149: if (id < 0 || id > channels_alloc) {
1.41 markus 150: log("channel_lookup: %d: bad id", id);
151: return NULL;
152: }
1.113 markus 153: c = channels[id];
154: if (c == NULL) {
1.41 markus 155: log("channel_lookup: %d: bad id: channel free", id);
156: return NULL;
157: }
158: return c;
1.55 markus 159: }
160:
1.27 markus 161: /*
1.55 markus 162: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 163: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 164: */
1.1 deraadt 165:
1.127 itojun 166: static void
1.71 markus 167: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
168: int extusage, int nonblock)
1.1 deraadt 169: {
1.25 markus 170: /* Update the maximum file descriptor value. */
1.84 markus 171: channel_max_fd = MAX(channel_max_fd, rfd);
172: channel_max_fd = MAX(channel_max_fd, wfd);
173: channel_max_fd = MAX(channel_max_fd, efd);
174:
1.27 markus 175: /* XXX set close-on-exec -markus */
1.55 markus 176:
1.52 markus 177: c->rfd = rfd;
178: c->wfd = wfd;
179: c->sock = (rfd == wfd) ? rfd : -1;
180: c->efd = efd;
181: c->extended_usage = extusage;
1.71 markus 182:
1.91 markus 183: /* XXX ugly hack: nonblock is only set by the server */
184: if (nonblock && isatty(c->rfd)) {
1.94 markus 185: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 186: c->isatty = 1;
187: if (!isatty(c->wfd)) {
1.94 markus 188: error("channel %d: wfd %d is not a tty?",
1.91 markus 189: c->self, c->wfd);
190: }
191: } else {
192: c->isatty = 0;
193: }
194:
1.71 markus 195: /* enable nonblocking mode */
196: if (nonblock) {
197: if (rfd != -1)
198: set_nonblock(rfd);
199: if (wfd != -1)
200: set_nonblock(wfd);
201: if (efd != -1)
202: set_nonblock(efd);
203: }
1.52 markus 204: }
205:
206: /*
207: * Allocate a new channel object and set its type and socket. This will cause
208: * remote_name to be freed.
209: */
210:
1.113 markus 211: Channel *
1.52 markus 212: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 213: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 214: {
215: int i, found;
216: Channel *c;
1.25 markus 217:
218: /* Do initial allocation if this is the first call. */
219: if (channels_alloc == 0) {
220: channels_alloc = 10;
1.113 markus 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.113 markus 223: channels[i] = NULL;
1.126 markus 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.113 markus 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 244: memset(c, 0, sizeof(Channel));
1.25 markus 245: buffer_init(&c->input);
246: buffer_init(&c->output);
1.41 markus 247: buffer_init(&c->extended);
1.159 markus 248: c->ostate = CHAN_OUTPUT_OPEN;
249: c->istate = CHAN_INPUT_OPEN;
250: c->flags = 0;
1.71 markus 251: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 252: c->self = found;
253: c->type = type;
1.41 markus 254: c->ctype = ctype;
1.51 markus 255: c->local_window = window;
256: c->local_window_max = window;
257: c->local_consumed = 0;
258: c->local_maxpacket = maxpack;
1.25 markus 259: c->remote_id = -1;
260: c->remote_name = remote_name;
1.41 markus 261: c->remote_window = 0;
262: c->remote_maxpacket = 0;
1.133 markus 263: c->force_drain = 0;
1.149 markus 264: c->single_connection = 0;
1.131 markus 265: c->detach_user = NULL;
1.165 markus 266: c->confirm = NULL;
1.65 markus 267: c->input_filter = NULL;
1.25 markus 268: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 269: return c;
1.1 deraadt 270: }
1.52 markus 271:
1.132 markus 272: static int
273: channel_find_maxfd(void)
274: {
275: int i, max = 0;
276: Channel *c;
277:
278: for (i = 0; i < channels_alloc; i++) {
279: c = channels[i];
280: if (c != NULL) {
281: max = MAX(max, c->rfd);
282: max = MAX(max, c->wfd);
283: max = MAX(max, c->efd);
284: }
285: }
286: return max;
287: }
288:
289: int
290: channel_close_fd(int *fdp)
291: {
292: int ret = 0, fd = *fdp;
293:
294: if (fd != -1) {
295: ret = close(fd);
296: *fdp = -1;
297: if (fd == channel_max_fd)
298: channel_max_fd = channel_find_maxfd();
299: }
300: return ret;
301: }
302:
1.52 markus 303: /* Close all channel fd/socket. */
304:
1.127 itojun 305: static void
1.52 markus 306: channel_close_fds(Channel *c)
307: {
1.118 markus 308: debug3("channel_close_fds: channel %d: r %d w %d e %d",
309: c->self, c->rfd, c->wfd, c->efd);
310:
1.132 markus 311: channel_close_fd(&c->sock);
312: channel_close_fd(&c->rfd);
313: channel_close_fd(&c->wfd);
314: channel_close_fd(&c->efd);
1.121 markus 315: }
316:
317: /* Free the channel and close its fd/socket. */
318:
319: void
320: channel_free(Channel *c)
321: {
322: char *s;
323: int i, n;
324:
325: for (n = 0, i = 0; i < channels_alloc; i++)
326: if (channels[i])
327: n++;
328: debug("channel_free: channel %d: %s, nchannels %d", c->self,
329: c->remote_name ? c->remote_name : "???", n);
330:
331: s = channel_open_message();
332: debug3("channel_free: status: %s", s);
333: xfree(s);
334:
335: if (c->sock != -1)
336: shutdown(c->sock, SHUT_RDWR);
337: channel_close_fds(c);
338: buffer_free(&c->input);
339: buffer_free(&c->output);
340: buffer_free(&c->extended);
341: if (c->remote_name) {
342: xfree(c->remote_name);
343: c->remote_name = NULL;
344: }
345: channels[c->self] = NULL;
346: xfree(c);
347: }
348:
349: void
1.126 markus 350: channel_free_all(void)
1.121 markus 351: {
352: int i;
353:
1.126 markus 354: for (i = 0; i < channels_alloc; i++)
355: if (channels[i] != NULL)
356: channel_free(channels[i]);
1.131 markus 357: }
358:
1.121 markus 359: /*
360: * Closes the sockets/fds of all channels. This is used to close extra file
361: * descriptors after a fork.
362: */
363:
364: void
1.142 itojun 365: channel_close_all(void)
1.121 markus 366: {
367: int i;
368:
369: for (i = 0; i < channels_alloc; i++)
370: if (channels[i] != NULL)
371: channel_close_fds(channels[i]);
372: }
373:
374: /*
1.131 markus 375: * Stop listening to channels.
376: */
377:
378: void
379: channel_stop_listening(void)
380: {
381: int i;
382: Channel *c;
383:
384: for (i = 0; i < channels_alloc; i++) {
385: c = channels[i];
386: if (c != NULL) {
387: switch (c->type) {
388: case SSH_CHANNEL_AUTH_SOCKET:
389: case SSH_CHANNEL_PORT_LISTENER:
390: case SSH_CHANNEL_RPORT_LISTENER:
391: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 392: channel_close_fd(&c->sock);
1.131 markus 393: channel_free(c);
394: break;
395: }
396: }
397: }
398: }
399:
400: /*
1.121 markus 401: * Returns true if no channel has too much buffered data, and false if one or
402: * more channel is overfull.
403: */
404:
405: int
1.142 itojun 406: channel_not_very_much_buffered_data(void)
1.121 markus 407: {
408: u_int i;
409: Channel *c;
410:
411: for (i = 0; i < channels_alloc; i++) {
412: c = channels[i];
413: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 414: #if 0
415: if (!compat20 &&
416: buffer_len(&c->input) > packet_get_maxsize()) {
1.121 markus 417: debug("channel %d: big input buffer %d",
418: c->self, buffer_len(&c->input));
419: return 0;
420: }
1.136 markus 421: #endif
1.121 markus 422: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.136 markus 423: debug("channel %d: big output buffer %d > %d",
424: c->self, buffer_len(&c->output),
425: packet_get_maxsize());
1.121 markus 426: return 0;
427: }
428: }
429: }
430: return 1;
431: }
432:
433: /* Returns true if any channel is still open. */
434:
435: int
1.142 itojun 436: channel_still_open(void)
1.121 markus 437: {
438: int i;
439: Channel *c;
440:
441: for (i = 0; i < channels_alloc; i++) {
442: c = channels[i];
443: if (c == NULL)
444: continue;
445: switch (c->type) {
446: case SSH_CHANNEL_X11_LISTENER:
447: case SSH_CHANNEL_PORT_LISTENER:
448: case SSH_CHANNEL_RPORT_LISTENER:
449: case SSH_CHANNEL_CLOSED:
450: case SSH_CHANNEL_AUTH_SOCKET:
451: case SSH_CHANNEL_DYNAMIC:
452: case SSH_CHANNEL_CONNECTING:
453: case SSH_CHANNEL_ZOMBIE:
454: continue;
455: case SSH_CHANNEL_LARVAL:
456: if (!compat20)
457: fatal("cannot happen: SSH_CHANNEL_LARVAL");
458: continue;
459: case SSH_CHANNEL_OPENING:
460: case SSH_CHANNEL_OPEN:
461: case SSH_CHANNEL_X11_OPEN:
462: return 1;
463: case SSH_CHANNEL_INPUT_DRAINING:
464: case SSH_CHANNEL_OUTPUT_DRAINING:
465: if (!compat13)
466: fatal("cannot happen: OUT_DRAIN");
467: return 1;
468: default:
469: fatal("channel_still_open: bad channel type %d", c->type);
470: /* NOTREACHED */
471: }
472: }
473: return 0;
474: }
475:
476: /* Returns the id of an open channel suitable for keepaliving */
477:
478: int
1.142 itojun 479: channel_find_open(void)
1.121 markus 480: {
481: int i;
482: Channel *c;
483:
484: for (i = 0; i < channels_alloc; i++) {
485: c = channels[i];
486: if (c == NULL)
487: continue;
488: switch (c->type) {
489: case SSH_CHANNEL_CLOSED:
490: case SSH_CHANNEL_DYNAMIC:
491: case SSH_CHANNEL_X11_LISTENER:
492: case SSH_CHANNEL_PORT_LISTENER:
493: case SSH_CHANNEL_RPORT_LISTENER:
494: case SSH_CHANNEL_OPENING:
495: case SSH_CHANNEL_CONNECTING:
496: case SSH_CHANNEL_ZOMBIE:
497: continue;
498: case SSH_CHANNEL_LARVAL:
499: case SSH_CHANNEL_AUTH_SOCKET:
500: case SSH_CHANNEL_OPEN:
501: case SSH_CHANNEL_X11_OPEN:
502: return i;
503: case SSH_CHANNEL_INPUT_DRAINING:
504: case SSH_CHANNEL_OUTPUT_DRAINING:
505: if (!compat13)
506: fatal("cannot happen: OUT_DRAIN");
507: return i;
508: default:
509: fatal("channel_find_open: bad channel type %d", c->type);
510: /* NOTREACHED */
511: }
512: }
513: return -1;
514: }
515:
516:
517: /*
518: * Returns a message describing the currently open forwarded connections,
519: * suitable for sending to the client. The message contains crlf pairs for
520: * newlines.
521: */
522:
523: char *
1.142 itojun 524: channel_open_message(void)
1.121 markus 525: {
526: Buffer buffer;
527: Channel *c;
528: char buf[1024], *cp;
529: int i;
530:
531: buffer_init(&buffer);
532: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
533: buffer_append(&buffer, buf, strlen(buf));
534: for (i = 0; i < channels_alloc; i++) {
535: c = channels[i];
536: if (c == NULL)
537: continue;
538: switch (c->type) {
539: case SSH_CHANNEL_X11_LISTENER:
540: case SSH_CHANNEL_PORT_LISTENER:
541: case SSH_CHANNEL_RPORT_LISTENER:
542: case SSH_CHANNEL_CLOSED:
543: case SSH_CHANNEL_AUTH_SOCKET:
544: case SSH_CHANNEL_ZOMBIE:
545: continue;
546: case SSH_CHANNEL_LARVAL:
547: case SSH_CHANNEL_OPENING:
548: case SSH_CHANNEL_CONNECTING:
549: case SSH_CHANNEL_DYNAMIC:
550: case SSH_CHANNEL_OPEN:
551: case SSH_CHANNEL_X11_OPEN:
552: case SSH_CHANNEL_INPUT_DRAINING:
553: case SSH_CHANNEL_OUTPUT_DRAINING:
554: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
555: c->self, c->remote_name,
556: c->type, c->remote_id,
557: c->istate, buffer_len(&c->input),
558: c->ostate, buffer_len(&c->output),
559: c->rfd, c->wfd);
560: buffer_append(&buffer, buf, strlen(buf));
561: continue;
562: default:
563: fatal("channel_open_message: bad channel type %d", c->type);
564: /* NOTREACHED */
565: }
566: }
567: buffer_append(&buffer, "\0", 1);
568: cp = xstrdup(buffer_ptr(&buffer));
569: buffer_free(&buffer);
570: return cp;
571: }
572:
573: void
574: channel_send_open(int id)
575: {
576: Channel *c = channel_lookup(id);
577: if (c == NULL) {
578: log("channel_send_open: %d: bad id", id);
579: return;
580: }
581: debug("send channel open %d", id);
582: packet_start(SSH2_MSG_CHANNEL_OPEN);
583: packet_put_cstring(c->ctype);
584: packet_put_int(c->self);
585: packet_put_int(c->local_window);
586: packet_put_int(c->local_maxpacket);
587: packet_send();
588: }
589:
590: void
1.166 markus 591: channel_request_start(int local_id, char *service, int wantconfirm)
1.121 markus 592: {
1.166 markus 593: Channel *c = channel_lookup(local_id);
1.121 markus 594: if (c == NULL) {
1.166 markus 595: log("channel_request_start: %d: unknown channel id", local_id);
1.121 markus 596: return;
597: }
1.166 markus 598: debug("channel request %d: %s", local_id, service) ;
1.121 markus 599: packet_start(SSH2_MSG_CHANNEL_REQUEST);
600: packet_put_int(c->remote_id);
601: packet_put_cstring(service);
602: packet_put_char(wantconfirm);
603: }
604: void
1.165 markus 605: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 606: {
607: Channel *c = channel_lookup(id);
608: if (c == NULL) {
1.165 markus 609: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 610: return;
611: }
1.165 markus 612: c->confirm = fn;
1.121 markus 613: }
614: void
615: channel_register_cleanup(int id, channel_callback_fn *fn)
616: {
617: Channel *c = channel_lookup(id);
618: if (c == NULL) {
619: log("channel_register_cleanup: %d: bad id", id);
620: return;
621: }
1.131 markus 622: c->detach_user = fn;
1.121 markus 623: }
624: void
625: channel_cancel_cleanup(int id)
626: {
627: Channel *c = channel_lookup(id);
628: if (c == NULL) {
629: log("channel_cancel_cleanup: %d: bad id", id);
630: return;
1.52 markus 631: }
1.131 markus 632: c->detach_user = NULL;
1.121 markus 633: }
634: void
635: channel_register_filter(int id, channel_filter_fn *fn)
636: {
637: Channel *c = channel_lookup(id);
638: if (c == NULL) {
639: log("channel_register_filter: %d: bad id", id);
640: return;
1.52 markus 641: }
1.121 markus 642: c->input_filter = fn;
1.52 markus 643: }
644:
1.49 markus 645: void
1.121 markus 646: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 ! markus 647: int extusage, int nonblock, u_int window_max)
1.1 deraadt 648: {
1.121 markus 649: Channel *c = channel_lookup(id);
650: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
651: fatal("channel_activate for non-larval channel %d.", id);
652: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
653: c->type = SSH_CHANNEL_OPEN;
1.168 ! markus 654: c->local_window = c->local_window_max = window_max;
1.121 markus 655: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
656: packet_put_int(c->remote_id);
657: packet_put_int(c->local_window);
658: packet_send();
1.1 deraadt 659: }
660:
1.27 markus 661: /*
1.41 markus 662: * 'channel_pre*' are called just before select() to add any bits relevant to
663: * channels in the select bitmasks.
664: */
665: /*
666: * 'channel_post*': perform any appropriate operations for channels which
667: * have events pending.
1.27 markus 668: */
1.41 markus 669: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
670: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
671: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
672:
1.127 itojun 673: static void
1.41 markus 674: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
675: {
676: FD_SET(c->sock, readset);
677: }
678:
1.127 itojun 679: static void
1.75 markus 680: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
681: {
682: debug3("channel %d: waiting for connection", c->self);
683: FD_SET(c->sock, writeset);
684: }
685:
1.127 itojun 686: static void
1.41 markus 687: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
688: {
689: if (buffer_len(&c->input) < packet_get_maxsize())
690: FD_SET(c->sock, readset);
691: if (buffer_len(&c->output) > 0)
692: FD_SET(c->sock, writeset);
693: }
1.1 deraadt 694:
1.127 itojun 695: static void
1.157 markus 696: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 697: {
1.157 markus 698: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 699:
1.44 markus 700: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 701: limit > 0 &&
702: buffer_len(&c->input) < limit)
1.44 markus 703: FD_SET(c->rfd, readset);
704: if (c->ostate == CHAN_OUTPUT_OPEN ||
705: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
706: if (buffer_len(&c->output) > 0) {
707: FD_SET(c->wfd, writeset);
708: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
709: chan_obuf_empty(c);
710: }
711: }
712: /** XXX check close conditions, too */
1.157 markus 713: if (compat20 && c->efd != -1) {
1.44 markus 714: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
715: buffer_len(&c->extended) > 0)
716: FD_SET(c->efd, writeset);
717: else if (c->extended_usage == CHAN_EXTENDED_READ &&
718: buffer_len(&c->extended) < c->remote_window)
719: FD_SET(c->efd, readset);
720: }
721: }
722:
1.127 itojun 723: static void
1.41 markus 724: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
725: {
726: if (buffer_len(&c->input) == 0) {
727: packet_start(SSH_MSG_CHANNEL_CLOSE);
728: packet_put_int(c->remote_id);
729: packet_send();
730: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 731: debug("channel %d: closing after input drain.", c->self);
1.41 markus 732: }
733: }
734:
1.127 itojun 735: static void
1.41 markus 736: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
737: {
738: if (buffer_len(&c->output) == 0)
1.113 markus 739: chan_mark_dead(c);
1.49 markus 740: else
1.41 markus 741: FD_SET(c->sock, writeset);
742: }
743:
744: /*
745: * This is a special state for X11 authentication spoofing. An opened X11
746: * connection (when authentication spoofing is being done) remains in this
747: * state until the first packet has been completely read. The authentication
748: * data in that packet is then substituted by the real data if it matches the
749: * fake data, and the channel is put into normal mode.
1.51 markus 750: * XXX All this happens at the client side.
1.121 markus 751: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 752: */
1.127 itojun 753: static int
1.121 markus 754: x11_open_helper(Buffer *b)
1.1 deraadt 755: {
1.77 markus 756: u_char *ucp;
757: u_int proto_len, data_len;
1.25 markus 758:
1.41 markus 759: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 760: if (buffer_len(b) < 12)
1.41 markus 761: return 0;
762:
763: /* Parse the lengths of variable-length fields. */
1.155 stevesk 764: ucp = buffer_ptr(b);
1.41 markus 765: if (ucp[0] == 0x42) { /* Byte order MSB first. */
766: proto_len = 256 * ucp[6] + ucp[7];
767: data_len = 256 * ucp[8] + ucp[9];
768: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
769: proto_len = ucp[6] + 256 * ucp[7];
770: data_len = ucp[8] + 256 * ucp[9];
771: } else {
772: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 773: ucp[0]);
1.41 markus 774: return -1;
775: }
776:
777: /* Check if the whole packet is in buffer. */
1.121 markus 778: if (buffer_len(b) <
1.41 markus 779: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
780: return 0;
781:
782: /* Check if authentication protocol matches. */
783: if (proto_len != strlen(x11_saved_proto) ||
784: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
785: debug("X11 connection uses different authentication protocol.");
786: return -1;
787: }
788: /* Check if authentication data matches our fake data. */
789: if (data_len != x11_fake_data_len ||
790: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
791: x11_fake_data, x11_fake_data_len) != 0) {
792: debug("X11 auth data does not match fake data.");
793: return -1;
794: }
795: /* Check fake data length */
796: if (x11_fake_data_len != x11_saved_data_len) {
797: error("X11 fake_data_len %d != saved_data_len %d",
798: x11_fake_data_len, x11_saved_data_len);
799: return -1;
800: }
801: /*
802: * Received authentication protocol and data match
803: * our fake data. Substitute the fake data with real
804: * data.
805: */
806: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
807: x11_saved_data, x11_saved_data_len);
808: return 1;
809: }
810:
1.127 itojun 811: static void
1.41 markus 812: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
813: {
1.121 markus 814: int ret = x11_open_helper(&c->output);
1.41 markus 815: if (ret == 1) {
816: /* Start normal processing for the channel. */
817: c->type = SSH_CHANNEL_OPEN;
1.47 markus 818: channel_pre_open_13(c, readset, writeset);
1.41 markus 819: } else if (ret == -1) {
820: /*
821: * We have received an X11 connection that has bad
822: * authentication information.
823: */
1.98 millert 824: log("X11 connection rejected because of wrong authentication.");
1.41 markus 825: buffer_clear(&c->input);
826: buffer_clear(&c->output);
1.132 markus 827: channel_close_fd(&c->sock);
1.41 markus 828: c->sock = -1;
829: c->type = SSH_CHANNEL_CLOSED;
830: packet_start(SSH_MSG_CHANNEL_CLOSE);
831: packet_put_int(c->remote_id);
832: packet_send();
833: }
834: }
1.25 markus 835:
1.127 itojun 836: static void
1.51 markus 837: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 838: {
1.121 markus 839: int ret = x11_open_helper(&c->output);
1.133 markus 840:
841: /* c->force_drain = 1; */
842:
1.41 markus 843: if (ret == 1) {
844: c->type = SSH_CHANNEL_OPEN;
1.157 markus 845: channel_pre_open(c, readset, writeset);
1.41 markus 846: } else if (ret == -1) {
1.156 markus 847: log("X11 connection rejected because of wrong authentication.");
1.41 markus 848: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 849: chan_read_failed(c);
850: buffer_clear(&c->input);
851: chan_ibuf_empty(c);
852: buffer_clear(&c->output);
853: /* for proto v1, the peer will send an IEOF */
854: if (compat20)
855: chan_write_failed(c);
856: else
857: c->type = SSH_CHANNEL_OPEN;
1.41 markus 858: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
859: }
860: }
1.25 markus 861:
1.104 markus 862: /* try to decode a socks4 header */
1.127 itojun 863: static int
1.104 markus 864: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 865: {
866: u_char *p, *host;
1.109 markus 867: int len, have, i, found;
1.148 deraadt 868: char username[256];
1.103 markus 869: struct {
870: u_int8_t version;
871: u_int8_t command;
872: u_int16_t dest_port;
1.104 markus 873: struct in_addr dest_addr;
1.103 markus 874: } s4_req, s4_rsp;
875:
1.104 markus 876: debug2("channel %d: decode socks4", c->self);
1.109 markus 877:
878: have = buffer_len(&c->input);
879: len = sizeof(s4_req);
880: if (have < len)
881: return 0;
882: p = buffer_ptr(&c->input);
883: for (found = 0, i = len; i < have; i++) {
884: if (p[i] == '\0') {
885: found = 1;
886: break;
887: }
888: if (i > 1024) {
889: /* the peer is probably sending garbage */
890: debug("channel %d: decode socks4: too long",
891: c->self);
892: return -1;
893: }
894: }
895: if (!found)
896: return 0;
1.103 markus 897: buffer_get(&c->input, (char *)&s4_req.version, 1);
898: buffer_get(&c->input, (char *)&s4_req.command, 1);
899: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 900: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 901: have = buffer_len(&c->input);
1.103 markus 902: p = buffer_ptr(&c->input);
903: len = strlen(p);
1.106 markus 904: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 905: if (len > have)
1.104 markus 906: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 907: c->self, len, have);
908: strlcpy(username, p, sizeof(username));
909: buffer_consume(&c->input, len);
910: buffer_consume(&c->input, 1); /* trailing '\0' */
911:
1.104 markus 912: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 913: strlcpy(c->path, host, sizeof(c->path));
914: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 915:
1.106 markus 916: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
917: c->self, host, c->host_port, s4_req.command);
1.103 markus 918:
1.104 markus 919: if (s4_req.command != 1) {
920: debug("channel %d: cannot handle: socks4 cn %d",
921: c->self, s4_req.command);
922: return -1;
1.103 markus 923: }
1.104 markus 924: s4_rsp.version = 0; /* vn: 0 for reply */
925: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 926: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 927: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 928: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 929: return 1;
930: }
931:
932: /* dynamic port forwarding */
1.127 itojun 933: static void
1.104 markus 934: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
935: {
936: u_char *p;
937: int have, ret;
1.103 markus 938:
1.104 markus 939: have = buffer_len(&c->input);
1.137 markus 940: c->delayed = 0;
1.104 markus 941: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 942: /* buffer_dump(&c->input); */
1.104 markus 943: /* check if the fixed size part of the packet is in buffer. */
944: if (have < 4) {
945: /* need more */
946: FD_SET(c->sock, readset);
947: return;
948: }
949: /* try to guess the protocol */
950: p = buffer_ptr(&c->input);
951: switch (p[0]) {
952: case 0x04:
953: ret = channel_decode_socks4(c, readset, writeset);
954: break;
955: default:
956: ret = -1;
957: break;
958: }
959: if (ret < 0) {
1.113 markus 960: chan_mark_dead(c);
1.104 markus 961: } else if (ret == 0) {
962: debug2("channel %d: pre_dynamic: need more", c->self);
963: /* need more */
964: FD_SET(c->sock, readset);
965: } else {
966: /* switch to the next state */
967: c->type = SSH_CHANNEL_OPENING;
968: port_open_helper(c, "direct-tcpip");
969: }
1.103 markus 970: }
971:
1.41 markus 972: /* This is our fake X11 server socket. */
1.127 itojun 973: static void
1.41 markus 974: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
975: {
1.113 markus 976: Channel *nc;
1.41 markus 977: struct sockaddr addr;
1.162 stevesk 978: int newsock;
1.41 markus 979: socklen_t addrlen;
1.85 markus 980: char buf[16384], *remote_ipaddr;
1.51 markus 981: int remote_port;
1.25 markus 982:
1.41 markus 983: if (FD_ISSET(c->sock, readset)) {
984: debug("X11 connection requested.");
985: addrlen = sizeof(addr);
986: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 987: if (c->single_connection) {
988: debug("single_connection: closing X11 listener.");
989: channel_close_fd(&c->sock);
990: chan_mark_dead(c);
991: }
1.41 markus 992: if (newsock < 0) {
993: error("accept: %.100s", strerror(errno));
994: return;
995: }
1.162 stevesk 996: set_nodelay(newsock);
1.85 markus 997: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 998: remote_port = get_peer_port(newsock);
1.41 markus 999: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1000: remote_ipaddr, remote_port);
1.51 markus 1001:
1.113 markus 1002: nc = channel_new("accepted x11 socket",
1.51 markus 1003: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1004: c->local_window_max, c->local_maxpacket,
1.71 markus 1005: 0, xstrdup(buf), 1);
1.51 markus 1006: if (compat20) {
1007: packet_start(SSH2_MSG_CHANNEL_OPEN);
1008: packet_put_cstring("x11");
1.113 markus 1009: packet_put_int(nc->self);
1.149 markus 1010: packet_put_int(nc->local_window_max);
1011: packet_put_int(nc->local_maxpacket);
1.85 markus 1012: /* originator ipaddr and port */
1013: packet_put_cstring(remote_ipaddr);
1.57 markus 1014: if (datafellows & SSH_BUG_X11FWD) {
1015: debug("ssh2 x11 bug compat mode");
1016: } else {
1017: packet_put_int(remote_port);
1018: }
1.51 markus 1019: packet_send();
1020: } else {
1021: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1022: packet_put_int(nc->self);
1.121 markus 1023: if (packet_get_protocol_flags() &
1024: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1025: packet_put_cstring(buf);
1.51 markus 1026: packet_send();
1027: }
1.85 markus 1028: xfree(remote_ipaddr);
1.41 markus 1029: }
1030: }
1.25 markus 1031:
1.127 itojun 1032: static void
1.103 markus 1033: port_open_helper(Channel *c, char *rtype)
1034: {
1035: int direct;
1036: char buf[1024];
1037: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1038: u_short remote_port = get_peer_port(c->sock);
1039:
1040: direct = (strcmp(rtype, "direct-tcpip") == 0);
1041:
1042: snprintf(buf, sizeof buf,
1043: "%s: listening port %d for %.100s port %d, "
1044: "connect from %.200s port %d",
1045: rtype, c->listening_port, c->path, c->host_port,
1046: remote_ipaddr, remote_port);
1047:
1048: xfree(c->remote_name);
1049: c->remote_name = xstrdup(buf);
1050:
1051: if (compat20) {
1052: packet_start(SSH2_MSG_CHANNEL_OPEN);
1053: packet_put_cstring(rtype);
1054: packet_put_int(c->self);
1055: packet_put_int(c->local_window_max);
1056: packet_put_int(c->local_maxpacket);
1057: if (direct) {
1058: /* target host, port */
1059: packet_put_cstring(c->path);
1060: packet_put_int(c->host_port);
1061: } else {
1062: /* listen address, port */
1063: packet_put_cstring(c->path);
1064: packet_put_int(c->listening_port);
1065: }
1066: /* originator host and port */
1067: packet_put_cstring(remote_ipaddr);
1068: packet_put_int(remote_port);
1069: packet_send();
1070: } else {
1071: packet_start(SSH_MSG_PORT_OPEN);
1072: packet_put_int(c->self);
1073: packet_put_cstring(c->path);
1074: packet_put_int(c->host_port);
1.121 markus 1075: if (packet_get_protocol_flags() &
1076: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1077: packet_put_cstring(c->remote_name);
1078: packet_send();
1079: }
1080: xfree(remote_ipaddr);
1081: }
1082:
1.41 markus 1083: /*
1084: * This socket is listening for connections to a forwarded TCP/IP port.
1085: */
1.127 itojun 1086: static void
1.41 markus 1087: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1088: {
1.103 markus 1089: Channel *nc;
1.41 markus 1090: struct sockaddr addr;
1.113 markus 1091: int newsock, nextstate;
1.41 markus 1092: socklen_t addrlen;
1.103 markus 1093: char *rtype;
1.73 markus 1094:
1.41 markus 1095: if (FD_ISSET(c->sock, readset)) {
1096: debug("Connection to port %d forwarding "
1097: "to %.100s port %d requested.",
1098: c->listening_port, c->path, c->host_port);
1.103 markus 1099:
1.137 markus 1100: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1101: nextstate = SSH_CHANNEL_OPENING;
1102: rtype = "forwarded-tcpip";
1103: } else {
1104: if (c->host_port == 0) {
1105: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1106: rtype = "dynamic-tcpip";
1.137 markus 1107: } else {
1108: nextstate = SSH_CHANNEL_OPENING;
1109: rtype = "direct-tcpip";
1110: }
1111: }
1.103 markus 1112:
1.41 markus 1113: addrlen = sizeof(addr);
1114: newsock = accept(c->sock, &addr, &addrlen);
1115: if (newsock < 0) {
1116: error("accept: %.100s", strerror(errno));
1117: return;
1118: }
1.113 markus 1119: nc = channel_new(rtype,
1.103 markus 1120: nextstate, newsock, newsock, -1,
1.41 markus 1121: c->local_window_max, c->local_maxpacket,
1.103 markus 1122: 0, xstrdup(rtype), 1);
1123: nc->listening_port = c->listening_port;
1124: nc->host_port = c->host_port;
1125: strlcpy(nc->path, c->path, sizeof(nc->path));
1126:
1.137 markus 1127: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1128: /*
1129: * do not call the channel_post handler until
1130: * this flag has been reset by a pre-handler.
1131: * otherwise the FD_ISSET calls might overflow
1132: */
1133: nc->delayed = 1;
1134: } else {
1.103 markus 1135: port_open_helper(nc, rtype);
1.137 markus 1136: }
1.41 markus 1137: }
1138: }
1.25 markus 1139:
1.41 markus 1140: /*
1141: * This is the authentication agent socket listening for connections from
1142: * clients.
1143: */
1.127 itojun 1144: static void
1.41 markus 1145: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1146: {
1.113 markus 1147: Channel *nc;
1.121 markus 1148: char *name;
1.113 markus 1149: int newsock;
1.41 markus 1150: struct sockaddr addr;
1151: socklen_t addrlen;
1.25 markus 1152:
1.41 markus 1153: if (FD_ISSET(c->sock, readset)) {
1154: addrlen = sizeof(addr);
1155: newsock = accept(c->sock, &addr, &addrlen);
1156: if (newsock < 0) {
1157: error("accept from auth socket: %.100s", strerror(errno));
1158: return;
1159: }
1.121 markus 1160: name = xstrdup("accepted auth socket");
1.113 markus 1161: nc = channel_new("accepted auth socket",
1.73 markus 1162: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1163: c->local_window_max, c->local_maxpacket,
1.121 markus 1164: 0, name, 1);
1.73 markus 1165: if (compat20) {
1166: packet_start(SSH2_MSG_CHANNEL_OPEN);
1167: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1168: packet_put_int(nc->self);
1.73 markus 1169: packet_put_int(c->local_window_max);
1170: packet_put_int(c->local_maxpacket);
1171: } else {
1172: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1173: packet_put_int(nc->self);
1.73 markus 1174: }
1.41 markus 1175: packet_send();
1176: }
1177: }
1.25 markus 1178:
1.127 itojun 1179: static void
1.75 markus 1180: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1181: {
1.114 markus 1182: int err = 0;
1.129 stevesk 1183: socklen_t sz = sizeof(err);
1.114 markus 1184:
1.75 markus 1185: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1186: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1187: &sz) < 0) {
1188: err = errno;
1189: error("getsockopt SO_ERROR failed");
1190: }
1191: if (err == 0) {
1192: debug("channel %d: connected", c->self);
1193: c->type = SSH_CHANNEL_OPEN;
1194: if (compat20) {
1195: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1196: packet_put_int(c->remote_id);
1197: packet_put_int(c->self);
1198: packet_put_int(c->local_window);
1199: packet_put_int(c->local_maxpacket);
1200: } else {
1201: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1202: packet_put_int(c->remote_id);
1203: packet_put_int(c->self);
1204: }
1.75 markus 1205: } else {
1.114 markus 1206: debug("channel %d: not connected: %s",
1207: c->self, strerror(err));
1208: if (compat20) {
1209: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1210: packet_put_int(c->remote_id);
1211: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1212: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1213: packet_put_cstring(strerror(err));
1214: packet_put_cstring("");
1215: }
1.75 markus 1216: } else {
1.114 markus 1217: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1218: packet_put_int(c->remote_id);
1.75 markus 1219: }
1.114 markus 1220: chan_mark_dead(c);
1.75 markus 1221: }
1.114 markus 1222: packet_send();
1.75 markus 1223: }
1224: }
1225:
1.127 itojun 1226: static int
1.41 markus 1227: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1228: {
1229: char buf[16*1024];
1230: int len;
1.25 markus 1231:
1.118 markus 1232: if (c->rfd != -1 &&
1.41 markus 1233: FD_ISSET(c->rfd, readset)) {
1234: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1235: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1236: return 1;
1.41 markus 1237: if (len <= 0) {
1.51 markus 1238: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1239: c->self, c->rfd, len);
1.104 markus 1240: if (c->type != SSH_CHANNEL_OPEN) {
1241: debug("channel %d: not open", c->self);
1.113 markus 1242: chan_mark_dead(c);
1.103 markus 1243: return -1;
1.104 markus 1244: } else if (compat13) {
1.158 markus 1245: buffer_clear(&c->output);
1.41 markus 1246: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1247: debug("channel %d: input draining.", c->self);
1.25 markus 1248: } else {
1.41 markus 1249: chan_read_failed(c);
1.25 markus 1250: }
1.41 markus 1251: return -1;
1252: }
1.143 deraadt 1253: if (c->input_filter != NULL) {
1.66 markus 1254: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1255: debug("channel %d: filter stops", c->self);
1.65 markus 1256: chan_read_failed(c);
1257: }
1258: } else {
1259: buffer_append(&c->input, buf, len);
1260: }
1.41 markus 1261: }
1262: return 1;
1263: }
1.127 itojun 1264: static int
1.41 markus 1265: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1266: {
1.95 markus 1267: struct termios tio;
1.134 markus 1268: u_char *data;
1269: u_int dlen;
1.41 markus 1270: int len;
1.25 markus 1271:
1.41 markus 1272: /* Send buffered output data to the socket. */
1.118 markus 1273: if (c->wfd != -1 &&
1.41 markus 1274: FD_ISSET(c->wfd, writeset) &&
1275: buffer_len(&c->output) > 0) {
1.134 markus 1276: data = buffer_ptr(&c->output);
1277: dlen = buffer_len(&c->output);
1278: len = write(c->wfd, data, dlen);
1.53 markus 1279: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1280: return 1;
1.41 markus 1281: if (len <= 0) {
1.104 markus 1282: if (c->type != SSH_CHANNEL_OPEN) {
1283: debug("channel %d: not open", c->self);
1.113 markus 1284: chan_mark_dead(c);
1.104 markus 1285: return -1;
1286: } else if (compat13) {
1.158 markus 1287: buffer_clear(&c->output);
1.121 markus 1288: debug("channel %d: input draining.", c->self);
1.41 markus 1289: c->type = SSH_CHANNEL_INPUT_DRAINING;
1290: } else {
1291: chan_write_failed(c);
1292: }
1293: return -1;
1.91 markus 1294: }
1.134 markus 1295: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1296: if (tcgetattr(c->wfd, &tio) == 0 &&
1297: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1298: /*
1299: * Simulate echo to reduce the impact of
1.96 markus 1300: * traffic analysis. We need to match the
1.95 markus 1301: * size of a SSH2_MSG_CHANNEL_DATA message
1302: * (4 byte channel id + data)
1.91 markus 1303: */
1.95 markus 1304: packet_send_ignore(4 + len);
1.91 markus 1305: packet_send();
1306: }
1.25 markus 1307: }
1.41 markus 1308: buffer_consume(&c->output, len);
1.44 markus 1309: if (compat20 && len > 0) {
1310: c->local_consumed += len;
1311: }
1312: }
1313: return 1;
1314: }
1.127 itojun 1315: static int
1.44 markus 1316: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1317: {
1318: char buf[16*1024];
1319: int len;
1320:
1.45 markus 1321: /** XXX handle drain efd, too */
1.44 markus 1322: if (c->efd != -1) {
1323: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1324: FD_ISSET(c->efd, writeset) &&
1325: buffer_len(&c->extended) > 0) {
1326: len = write(c->efd, buffer_ptr(&c->extended),
1327: buffer_len(&c->extended));
1.70 markus 1328: debug2("channel %d: written %d to efd %d",
1.44 markus 1329: c->self, len, c->efd);
1.93 markus 1330: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1331: return 1;
1332: if (len <= 0) {
1333: debug2("channel %d: closing write-efd %d",
1334: c->self, c->efd);
1.132 markus 1335: channel_close_fd(&c->efd);
1.93 markus 1336: } else {
1.44 markus 1337: buffer_consume(&c->extended, len);
1338: c->local_consumed += len;
1339: }
1340: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1341: FD_ISSET(c->efd, readset)) {
1342: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1343: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1344: c->self, len, c->efd);
1.93 markus 1345: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1346: return 1;
1347: if (len <= 0) {
1348: debug2("channel %d: closing read-efd %d",
1.45 markus 1349: c->self, c->efd);
1.132 markus 1350: channel_close_fd(&c->efd);
1.93 markus 1351: } else {
1.44 markus 1352: buffer_append(&c->extended, buf, len);
1.93 markus 1353: }
1.44 markus 1354: }
1355: }
1356: return 1;
1357: }
1.127 itojun 1358: static int
1.93 markus 1359: channel_check_window(Channel *c)
1.44 markus 1360: {
1.104 markus 1361: if (c->type == SSH_CHANNEL_OPEN &&
1362: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1363: c->local_window < c->local_window_max/2 &&
1364: c->local_consumed > 0) {
1365: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1366: packet_put_int(c->remote_id);
1367: packet_put_int(c->local_consumed);
1368: packet_send();
1.70 markus 1369: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1370: c->self, c->local_window,
1371: c->local_consumed);
1372: c->local_window += c->local_consumed;
1373: c->local_consumed = 0;
1.1 deraadt 1374: }
1.41 markus 1375: return 1;
1.1 deraadt 1376: }
1377:
1.127 itojun 1378: static void
1.157 markus 1379: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1380: {
1.137 markus 1381: if (c->delayed)
1382: return;
1.41 markus 1383: channel_handle_rfd(c, readset, writeset);
1384: channel_handle_wfd(c, readset, writeset);
1.157 markus 1385: if (!compat20)
1.137 markus 1386: return;
1.44 markus 1387: channel_handle_efd(c, readset, writeset);
1.93 markus 1388: channel_check_window(c);
1.44 markus 1389: }
1390:
1.127 itojun 1391: static void
1.41 markus 1392: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1393: {
1.41 markus 1394: int len;
1395: /* Send buffered output data to the socket. */
1396: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1397: len = write(c->sock, buffer_ptr(&c->output),
1398: buffer_len(&c->output));
1399: if (len <= 0)
1.158 markus 1400: buffer_clear(&c->output);
1.41 markus 1401: else
1402: buffer_consume(&c->output, len);
1403: }
1404: }
1.25 markus 1405:
1.127 itojun 1406: static void
1.44 markus 1407: channel_handler_init_20(void)
1408: {
1.157 markus 1409: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1410: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1411: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1412: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1413: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1414: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1415: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1416: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1417:
1.157 markus 1418: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1419: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1420: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1421: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1422: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1423: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1424: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1425: }
1426:
1.127 itojun 1427: static void
1.41 markus 1428: channel_handler_init_13(void)
1429: {
1430: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1431: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1432: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1433: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1434: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1435: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1436: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1437: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1438: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1439:
1.157 markus 1440: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1441: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1442: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1443: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1444: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1445: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1446: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1447: }
1.25 markus 1448:
1.127 itojun 1449: static void
1.41 markus 1450: channel_handler_init_15(void)
1451: {
1.157 markus 1452: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1453: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1454: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1455: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1456: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1457: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1458: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1459:
1.41 markus 1460: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1461: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1462: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1463: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1464: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1465: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1466: }
1.27 markus 1467:
1.127 itojun 1468: static void
1.41 markus 1469: channel_handler_init(void)
1470: {
1471: int i;
1.148 deraadt 1472: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1473: channel_pre[i] = NULL;
1474: channel_post[i] = NULL;
1475: }
1.44 markus 1476: if (compat20)
1477: channel_handler_init_20();
1478: else if (compat13)
1.41 markus 1479: channel_handler_init_13();
1480: else
1481: channel_handler_init_15();
1482: }
1.25 markus 1483:
1.140 markus 1484: /* gc dead channels */
1485: static void
1486: channel_garbage_collect(Channel *c)
1487: {
1488: if (c == NULL)
1489: return;
1490: if (c->detach_user != NULL) {
1491: if (!chan_is_dead(c, 0))
1492: return;
1493: debug("channel %d: gc: notify user", c->self);
1494: c->detach_user(c->self, NULL);
1495: /* if we still have a callback */
1496: if (c->detach_user != NULL)
1497: return;
1498: debug("channel %d: gc: user detached", c->self);
1499: }
1500: if (!chan_is_dead(c, 1))
1501: return;
1502: debug("channel %d: garbage collecting", c->self);
1503: channel_free(c);
1504: }
1505:
1.127 itojun 1506: static void
1.41 markus 1507: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1508: {
1509: static int did_init = 0;
1510: int i;
1511: Channel *c;
1.25 markus 1512:
1.41 markus 1513: if (!did_init) {
1514: channel_handler_init();
1515: did_init = 1;
1516: }
1517: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1518: c = channels[i];
1519: if (c == NULL)
1.41 markus 1520: continue;
1.118 markus 1521: if (ftab[c->type] != NULL)
1522: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1523: channel_garbage_collect(c);
1.1 deraadt 1524: }
1525: }
1526:
1.121 markus 1527: /*
1528: * Allocate/update select bitmasks and add any bits relevant to channels in
1529: * select bitmasks.
1530: */
1.49 markus 1531: void
1.100 markus 1532: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1533: int *nallocp, int rekeying)
1.41 markus 1534: {
1.84 markus 1535: int n;
1536: u_int sz;
1537:
1538: n = MAX(*maxfdp, channel_max_fd);
1539:
1540: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1541: /* perhaps check sz < nalloc/2 and shrink? */
1542: if (*readsetp == NULL || sz > *nallocp) {
1543: *readsetp = xrealloc(*readsetp, sz);
1544: *writesetp = xrealloc(*writesetp, sz);
1545: *nallocp = sz;
1.84 markus 1546: }
1.132 markus 1547: *maxfdp = n;
1.84 markus 1548: memset(*readsetp, 0, sz);
1549: memset(*writesetp, 0, sz);
1550:
1.100 markus 1551: if (!rekeying)
1552: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1553: }
1554:
1.121 markus 1555: /*
1556: * After select, perform any appropriate operations for channels which have
1557: * events pending.
1558: */
1.49 markus 1559: void
1.41 markus 1560: channel_after_select(fd_set * readset, fd_set * writeset)
1561: {
1562: channel_handler(channel_post, readset, writeset);
1563: }
1564:
1.121 markus 1565:
1.84 markus 1566: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1567:
1.49 markus 1568: void
1.142 itojun 1569: channel_output_poll(void)
1.1 deraadt 1570: {
1.25 markus 1571: int len, i;
1.41 markus 1572: Channel *c;
1.1 deraadt 1573:
1.25 markus 1574: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1575: c = channels[i];
1576: if (c == NULL)
1577: continue;
1.37 markus 1578:
1.121 markus 1579: /*
1580: * We are only interested in channels that can have buffered
1581: * incoming data.
1582: */
1.37 markus 1583: if (compat13) {
1.41 markus 1584: if (c->type != SSH_CHANNEL_OPEN &&
1585: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1586: continue;
1587: } else {
1.41 markus 1588: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1589: continue;
1590: }
1.46 markus 1591: if (compat20 &&
1592: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1593: /* XXX is this true? */
1.140 markus 1594: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1595: continue;
1596: }
1.25 markus 1597:
1598: /* Get the amount of buffered data for this channel. */
1.93 markus 1599: if ((c->istate == CHAN_INPUT_OPEN ||
1600: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1601: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1602: /*
1603: * Send some data for the other side over the secure
1604: * connection.
1605: */
1.44 markus 1606: if (compat20) {
1607: if (len > c->remote_window)
1608: len = c->remote_window;
1609: if (len > c->remote_maxpacket)
1610: len = c->remote_maxpacket;
1.25 markus 1611: } else {
1.44 markus 1612: if (packet_is_interactive()) {
1613: if (len > 1024)
1614: len = 512;
1615: } else {
1616: /* Keep the packets at reasonable size. */
1617: if (len > packet_get_maxsize()/2)
1618: len = packet_get_maxsize()/2;
1619: }
1.25 markus 1620: }
1.41 markus 1621: if (len > 0) {
1.44 markus 1622: packet_start(compat20 ?
1623: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1624: packet_put_int(c->remote_id);
1625: packet_put_string(buffer_ptr(&c->input), len);
1626: packet_send();
1627: buffer_consume(&c->input, len);
1628: c->remote_window -= len;
1629: }
1630: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1631: if (compat13)
1632: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1633: /*
1634: * input-buffer is empty and read-socket shutdown:
1635: * tell peer, that we will not send more data: send IEOF
1636: */
1.41 markus 1637: chan_ibuf_empty(c);
1.25 markus 1638: }
1.44 markus 1639: /* Send extended data, i.e. stderr */
1640: if (compat20 &&
1641: c->remote_window > 0 &&
1642: (len = buffer_len(&c->extended)) > 0 &&
1643: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1644: debug2("channel %d: rwin %d elen %d euse %d",
1645: c->self, c->remote_window, buffer_len(&c->extended),
1646: c->extended_usage);
1.44 markus 1647: if (len > c->remote_window)
1648: len = c->remote_window;
1649: if (len > c->remote_maxpacket)
1650: len = c->remote_maxpacket;
1651: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1652: packet_put_int(c->remote_id);
1653: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1654: packet_put_string(buffer_ptr(&c->extended), len);
1655: packet_send();
1656: buffer_consume(&c->extended, len);
1657: c->remote_window -= len;
1.93 markus 1658: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1659: }
1.25 markus 1660: }
1.1 deraadt 1661: }
1662:
1.121 markus 1663:
1664: /* -- protocol input */
1.1 deraadt 1665:
1.49 markus 1666: void
1.154 markus 1667: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1668: {
1.37 markus 1669: int id;
1.25 markus 1670: char *data;
1.77 markus 1671: u_int data_len;
1.41 markus 1672: Channel *c;
1.25 markus 1673:
1674: /* Get the channel number and verify it. */
1.37 markus 1675: id = packet_get_int();
1.41 markus 1676: c = channel_lookup(id);
1677: if (c == NULL)
1.37 markus 1678: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1679:
1680: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1681: if (c->type != SSH_CHANNEL_OPEN &&
1682: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1683: return;
1684:
1685: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1686: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1687: return;
1688:
1689: /* Get the data. */
1690: data = packet_get_string(&data_len);
1.41 markus 1691:
1.143 deraadt 1692: if (compat20) {
1.44 markus 1693: if (data_len > c->local_maxpacket) {
1694: log("channel %d: rcvd big packet %d, maxpack %d",
1695: c->self, data_len, c->local_maxpacket);
1696: }
1697: if (data_len > c->local_window) {
1698: log("channel %d: rcvd too much data %d, win %d",
1699: c->self, data_len, c->local_window);
1700: xfree(data);
1701: return;
1702: }
1703: c->local_window -= data_len;
1704: }
1.152 markus 1705: packet_check_eom();
1.41 markus 1706: buffer_append(&c->output, data, data_len);
1.25 markus 1707: xfree(data);
1.1 deraadt 1708: }
1.121 markus 1709:
1.49 markus 1710: void
1.154 markus 1711: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1712: {
1713: int id;
1714: int tcode;
1715: char *data;
1.77 markus 1716: u_int data_len;
1.44 markus 1717: Channel *c;
1718:
1719: /* Get the channel number and verify it. */
1720: id = packet_get_int();
1721: c = channel_lookup(id);
1722:
1723: if (c == NULL)
1724: packet_disconnect("Received extended_data for bad channel %d.", id);
1725: if (c->type != SSH_CHANNEL_OPEN) {
1726: log("channel %d: ext data for non open", id);
1727: return;
1728: }
1729: tcode = packet_get_int();
1730: if (c->efd == -1 ||
1731: c->extended_usage != CHAN_EXTENDED_WRITE ||
1732: tcode != SSH2_EXTENDED_DATA_STDERR) {
1733: log("channel %d: bad ext data", c->self);
1734: return;
1735: }
1736: data = packet_get_string(&data_len);
1.152 markus 1737: packet_check_eom();
1.44 markus 1738: if (data_len > c->local_window) {
1739: log("channel %d: rcvd too much extended_data %d, win %d",
1740: c->self, data_len, c->local_window);
1741: xfree(data);
1742: return;
1743: }
1.70 markus 1744: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1745: c->local_window -= data_len;
1746: buffer_append(&c->extended, data, data_len);
1747: xfree(data);
1748: }
1749:
1.49 markus 1750: void
1.154 markus 1751: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1752: {
1753: int id;
1754: Channel *c;
1755:
1756: id = packet_get_int();
1.152 markus 1757: packet_check_eom();
1.41 markus 1758: c = channel_lookup(id);
1759: if (c == NULL)
1760: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1761: chan_rcvd_ieof(c);
1.133 markus 1762:
1763: /* XXX force input close */
1.156 markus 1764: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1765: debug("channel %d: FORCE input drain", c->self);
1766: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1767: if (buffer_len(&c->input) == 0)
1768: chan_ibuf_empty(c);
1.133 markus 1769: }
1770:
1.41 markus 1771: }
1.1 deraadt 1772:
1.49 markus 1773: void
1.154 markus 1774: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1775: {
1.41 markus 1776: int id;
1777: Channel *c;
1.1 deraadt 1778:
1.41 markus 1779: id = packet_get_int();
1.152 markus 1780: packet_check_eom();
1.41 markus 1781: c = channel_lookup(id);
1782: if (c == NULL)
1783: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1784:
1785: /*
1786: * Send a confirmation that we have closed the channel and no more
1787: * data is coming for it.
1788: */
1.25 markus 1789: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1790: packet_put_int(c->remote_id);
1.25 markus 1791: packet_send();
1792:
1.27 markus 1793: /*
1794: * If the channel is in closed state, we have sent a close request,
1795: * and the other side will eventually respond with a confirmation.
1796: * Thus, we cannot free the channel here, because then there would be
1797: * no-one to receive the confirmation. The channel gets freed when
1798: * the confirmation arrives.
1799: */
1.41 markus 1800: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1801: /*
1802: * Not a closed channel - mark it as draining, which will
1803: * cause it to be freed later.
1804: */
1.158 markus 1805: buffer_clear(&c->input);
1.41 markus 1806: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1807: }
1.1 deraadt 1808: }
1809:
1.41 markus 1810: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1811: void
1.154 markus 1812: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1813: {
1814: int id = packet_get_int();
1815: Channel *c = channel_lookup(id);
1.151 markus 1816:
1.152 markus 1817: packet_check_eom();
1.41 markus 1818: if (c == NULL)
1819: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1820: chan_rcvd_oclose(c);
1821: }
1.1 deraadt 1822:
1.49 markus 1823: void
1.154 markus 1824: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1825: {
1.41 markus 1826: int id = packet_get_int();
1827: Channel *c = channel_lookup(id);
1.1 deraadt 1828:
1.152 markus 1829: packet_check_eom();
1.41 markus 1830: if (c == NULL)
1831: packet_disconnect("Received close confirmation for "
1832: "out-of-range channel %d.", id);
1833: if (c->type != SSH_CHANNEL_CLOSED)
1834: packet_disconnect("Received close confirmation for "
1835: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1836: channel_free(c);
1.1 deraadt 1837: }
1838:
1.49 markus 1839: void
1.154 markus 1840: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1841: {
1.41 markus 1842: int id, remote_id;
1843: Channel *c;
1.1 deraadt 1844:
1.41 markus 1845: id = packet_get_int();
1846: c = channel_lookup(id);
1.25 markus 1847:
1.41 markus 1848: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1849: packet_disconnect("Received open confirmation for "
1850: "non-opening channel %d.", id);
1851: remote_id = packet_get_int();
1.27 markus 1852: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1853: c->remote_id = remote_id;
1854: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1855:
1856: if (compat20) {
1857: c->remote_window = packet_get_int();
1858: c->remote_maxpacket = packet_get_int();
1.165 markus 1859: if (c->confirm) {
1.70 markus 1860: debug2("callback start");
1.165 markus 1861: c->confirm(c->self, NULL);
1.70 markus 1862: debug2("callback done");
1.44 markus 1863: }
1864: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1865: c->remote_window, c->remote_maxpacket);
1866: }
1.152 markus 1867: packet_check_eom();
1.1 deraadt 1868: }
1869:
1.127 itojun 1870: static char *
1.114 markus 1871: reason2txt(int reason)
1872: {
1.143 deraadt 1873: switch (reason) {
1.114 markus 1874: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1875: return "administratively prohibited";
1876: case SSH2_OPEN_CONNECT_FAILED:
1877: return "connect failed";
1878: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1879: return "unknown channel type";
1880: case SSH2_OPEN_RESOURCE_SHORTAGE:
1881: return "resource shortage";
1882: }
1.117 stevesk 1883: return "unknown reason";
1.114 markus 1884: }
1885:
1.49 markus 1886: void
1.154 markus 1887: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1888: {
1.86 markus 1889: int id, reason;
1890: char *msg = NULL, *lang = NULL;
1.41 markus 1891: Channel *c;
1892:
1893: id = packet_get_int();
1894: c = channel_lookup(id);
1.25 markus 1895:
1.41 markus 1896: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1897: packet_disconnect("Received open failure for "
1898: "non-opening channel %d.", id);
1.44 markus 1899: if (compat20) {
1.86 markus 1900: reason = packet_get_int();
1.110 markus 1901: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1902: msg = packet_get_string(NULL);
1903: lang = packet_get_string(NULL);
1904: }
1.114 markus 1905: log("channel %d: open failed: %s%s%s", id,
1906: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1907: if (msg != NULL)
1908: xfree(msg);
1909: if (lang != NULL)
1910: xfree(lang);
1.44 markus 1911: }
1.152 markus 1912: packet_check_eom();
1.25 markus 1913: /* Free the channel. This will also close the socket. */
1.113 markus 1914: channel_free(c);
1.44 markus 1915: }
1916:
1.121 markus 1917: void
1.154 markus 1918: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1919: {
1920: Channel *c;
1921: int id, adjust;
1922:
1923: if (!compat20)
1924: return;
1925:
1926: /* Get the channel number and verify it. */
1927: id = packet_get_int();
1928: c = channel_lookup(id);
1.1 deraadt 1929:
1.121 markus 1930: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1931: log("Received window adjust for "
1932: "non-open channel %d.", id);
1933: return;
1934: }
1935: adjust = packet_get_int();
1.152 markus 1936: packet_check_eom();
1.121 markus 1937: debug2("channel %d: rcvd adjust %d", id, adjust);
1938: c->remote_window += adjust;
1939: }
1.1 deraadt 1940:
1.121 markus 1941: void
1.154 markus 1942: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1943: {
1.121 markus 1944: Channel *c = NULL;
1945: u_short host_port;
1946: char *host, *originator_string;
1947: int remote_id, sock = -1;
1948:
1949: remote_id = packet_get_int();
1950: host = packet_get_string(NULL);
1951: host_port = packet_get_int();
1.25 markus 1952:
1.121 markus 1953: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1954: originator_string = packet_get_string(NULL);
1955: } else {
1956: originator_string = xstrdup("unknown (remote did not supply name)");
1957: }
1.152 markus 1958: packet_check_eom();
1.121 markus 1959: sock = channel_connect_to(host, host_port);
1960: if (sock != -1) {
1961: c = channel_new("connected socket",
1962: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1963: originator_string, 1);
1.167 markus 1964: c->remote_id = remote_id;
1.25 markus 1965: }
1.121 markus 1966: if (c == NULL) {
1967: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1968: packet_put_int(remote_id);
1969: packet_send();
1970: }
1971: xfree(host);
1.1 deraadt 1972: }
1973:
1.121 markus 1974:
1975: /* -- tcp forwarding */
1.135 markus 1976:
1977: void
1978: channel_set_af(int af)
1979: {
1980: IPv4or6 = af;
1981: }
1.121 markus 1982:
1.160 markus 1983: static int
1984: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
1985: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 1986: {
1.113 markus 1987: Channel *c;
1.160 markus 1988: int success, sock, on = 1;
1.35 markus 1989: struct addrinfo hints, *ai, *aitop;
1.160 markus 1990: const char *host;
1.35 markus 1991: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 1992: struct linger linger;
1.25 markus 1993:
1.87 markus 1994: success = 0;
1.160 markus 1995: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
1996: listen_addr : host_to_connect;
1.87 markus 1997:
1.160 markus 1998: if (host == NULL) {
1999: error("No forward host name.");
2000: return success;
1.73 markus 2001: }
1.113 markus 2002: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2003: error("Forward host name too long.");
2004: return success;
2005: }
1.25 markus 2006:
1.28 markus 2007: /*
1.35 markus 2008: * getaddrinfo returns a loopback address if the hostname is
2009: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2010: */
1.35 markus 2011: memset(&hints, 0, sizeof(hints));
2012: hints.ai_family = IPv4or6;
2013: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2014: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2015: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2016: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2017: packet_disconnect("getaddrinfo: fatal error");
2018:
2019: for (ai = aitop; ai; ai = ai->ai_next) {
2020: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2021: continue;
2022: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2023: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2024: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2025: continue;
2026: }
2027: /* Create a port to listen for the host. */
2028: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2029: if (sock < 0) {
2030: /* this is no error since kernel may not support ipv6 */
2031: verbose("socket: %.100s", strerror(errno));
2032: continue;
2033: }
2034: /*
2035: * Set socket options. We would like the socket to disappear
2036: * as soon as it has been closed for whatever reason.
2037: */
2038: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2039: linger.l_onoff = 1;
2040: linger.l_linger = 5;
2041: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2042: debug("Local forwarding listening on %s port %s.", ntop, strport);
2043:
2044: /* Bind the socket to the address. */
2045: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2046: /* address can be in use ipv6 address is already bound */
2047: verbose("bind: %.100s", strerror(errno));
2048: close(sock);
2049: continue;
2050: }
2051: /* Start listening for connections on the socket. */
2052: if (listen(sock, 5) < 0) {
2053: error("listen: %.100s", strerror(errno));
2054: close(sock);
2055: continue;
2056: }
2057: /* Allocate a channel number for the socket. */
1.121 markus 2058: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2059: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2060: 0, xstrdup("port listener"), 1);
1.113 markus 2061: strlcpy(c->path, host, sizeof(c->path));
2062: c->host_port = port_to_connect;
2063: c->listening_port = listen_port;
1.35 markus 2064: success = 1;
2065: }
2066: if (success == 0)
1.160 markus 2067: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2068: listen_port);
1.35 markus 2069: freeaddrinfo(aitop);
1.87 markus 2070: return success;
1.25 markus 2071: }
1.1 deraadt 2072:
1.160 markus 2073: /* protocol local port fwd, used by ssh (and sshd in v1) */
2074: int
2075: channel_setup_local_fwd_listener(u_short listen_port,
2076: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2077: {
2078: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2079: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2080: }
2081:
2082: /* protocol v2 remote port fwd, used by sshd */
2083: int
2084: channel_setup_remote_fwd_listener(const char *listen_address,
2085: u_short listen_port, int gateway_ports)
2086: {
2087: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2088: listen_address, listen_port, NULL, 0, gateway_ports);
2089: }
2090:
1.27 markus 2091: /*
2092: * Initiate forwarding of connections to port "port" on remote host through
2093: * the secure channel to host:port from local side.
2094: */
1.1 deraadt 2095:
1.49 markus 2096: void
1.73 markus 2097: channel_request_remote_forwarding(u_short listen_port,
2098: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2099: {
1.153 markus 2100: int type, success = 0;
1.73 markus 2101:
1.25 markus 2102: /* Record locally that connection to this host/port is permitted. */
2103: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2104: fatal("channel_request_remote_forwarding: too many forwards");
2105:
2106: /* Send the forward request to the remote side. */
1.44 markus 2107: if (compat20) {
2108: const char *address_to_bind = "0.0.0.0";
2109: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2110: packet_put_cstring("tcpip-forward");
2111: packet_put_char(0); /* boolean: want reply */
2112: packet_put_cstring(address_to_bind);
2113: packet_put_int(listen_port);
1.73 markus 2114: packet_send();
2115: packet_write_wait();
2116: /* Assume that server accepts the request */
2117: success = 1;
1.44 markus 2118: } else {
2119: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2120: packet_put_int(listen_port);
2121: packet_put_cstring(host_to_connect);
1.44 markus 2122: packet_put_int(port_to_connect);
2123: packet_send();
2124: packet_write_wait();
1.73 markus 2125:
2126: /* Wait for response from the remote side. */
1.153 markus 2127: type = packet_read();
1.73 markus 2128: switch (type) {
2129: case SSH_SMSG_SUCCESS:
2130: success = 1;
2131: break;
2132: case SSH_SMSG_FAILURE:
2133: log("Warning: Server denied remote port forwarding.");
2134: break;
2135: default:
2136: /* Unknown packet */
2137: packet_disconnect("Protocol error for port forward request:"
2138: "received packet type %d.", type);
2139: }
2140: }
2141: if (success) {
2142: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2143: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2144: permitted_opens[num_permitted_opens].listen_port = listen_port;
2145: num_permitted_opens++;
1.44 markus 2146: }
1.1 deraadt 2147: }
2148:
1.27 markus 2149: /*
2150: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2151: * listening for the port, and sends back a success reply (or disconnect
2152: * message if there was an error). This never returns if there was an error.
2153: */
1.1 deraadt 2154:
1.49 markus 2155: void
1.56 markus 2156: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2157: {
1.31 markus 2158: u_short port, host_port;
1.25 markus 2159: char *hostname;
1.1 deraadt 2160:
1.25 markus 2161: /* Get arguments from the packet. */
2162: port = packet_get_int();
2163: hostname = packet_get_string(NULL);
2164: host_port = packet_get_int();
2165:
1.27 markus 2166: /*
2167: * Check that an unprivileged user is not trying to forward a
2168: * privileged port.
2169: */
1.25 markus 2170: if (port < IPPORT_RESERVED && !is_root)
2171: packet_disconnect("Requested forwarding of port %d but user is not root.",
2172: port);
1.73 markus 2173: /* Initiate forwarding */
1.160 markus 2174: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2175:
2176: /* Free the argument string. */
2177: xfree(hostname);
1.1 deraadt 2178: }
2179:
1.99 markus 2180: /*
2181: * Permits opening to any host/port if permitted_opens[] is empty. This is
2182: * usually called by the server, because the user could connect to any port
2183: * anyway, and the server has no way to know but to trust the client anyway.
2184: */
2185: void
1.142 itojun 2186: channel_permit_all_opens(void)
1.99 markus 2187: {
2188: if (num_permitted_opens == 0)
2189: all_opens_permitted = 1;
2190: }
2191:
1.101 markus 2192: void
1.99 markus 2193: channel_add_permitted_opens(char *host, int port)
2194: {
2195: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2196: fatal("channel_request_remote_forwarding: too many forwards");
2197: debug("allow port forwarding to host %s port %d", host, port);
2198:
2199: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2200: permitted_opens[num_permitted_opens].port_to_connect = port;
2201: num_permitted_opens++;
2202:
2203: all_opens_permitted = 0;
2204: }
2205:
1.101 markus 2206: void
1.99 markus 2207: channel_clear_permitted_opens(void)
2208: {
2209: int i;
2210:
2211: for (i = 0; i < num_permitted_opens; i++)
2212: xfree(permitted_opens[i].host_to_connect);
2213: num_permitted_opens = 0;
2214:
2215: }
2216:
2217:
2218: /* return socket to remote host, port */
1.127 itojun 2219: static int
1.99 markus 2220: connect_to(const char *host, u_short port)
1.41 markus 2221: {
2222: struct addrinfo hints, *ai, *aitop;
2223: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2224: int gaierr;
2225: int sock = -1;
2226:
2227: memset(&hints, 0, sizeof(hints));
2228: hints.ai_family = IPv4or6;
2229: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2230: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2231: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2232: error("connect_to %.100s: unknown host (%s)", host,
2233: gai_strerror(gaierr));
1.41 markus 2234: return -1;
2235: }
2236: for (ai = aitop; ai; ai = ai->ai_next) {
2237: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2238: continue;
2239: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2240: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2241: error("connect_to: getnameinfo failed");
1.41 markus 2242: continue;
2243: }
2244: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2245: if (sock < 0) {
2246: error("socket: %.100s", strerror(errno));
2247: continue;
2248: }
1.80 markus 2249: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2250: fatal("connect_to: F_SETFL: %s", strerror(errno));
2251: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2252: errno != EINPROGRESS) {
1.99 markus 2253: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2254: strerror(errno));
2255: close(sock);
1.89 stevesk 2256: continue; /* fail -- try next */
1.41 markus 2257: }
2258: break; /* success */
2259:
2260: }
2261: freeaddrinfo(aitop);
2262: if (!ai) {
1.99 markus 2263: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2264: return -1;
2265: }
2266: /* success */
2267: return sock;
2268: }
1.99 markus 2269:
1.73 markus 2270: int
1.130 stevesk 2271: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2272: {
2273: int i;
1.99 markus 2274:
1.73 markus 2275: for (i = 0; i < num_permitted_opens; i++)
2276: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2277: return connect_to(
1.73 markus 2278: permitted_opens[i].host_to_connect,
2279: permitted_opens[i].port_to_connect);
1.74 markus 2280: error("WARNING: Server requests forwarding for unknown listen_port %d",
2281: listen_port);
1.73 markus 2282: return -1;
2283: }
2284:
1.99 markus 2285: /* Check if connecting to that port is permitted and connect. */
2286: int
2287: channel_connect_to(const char *host, u_short port)
2288: {
2289: int i, permit;
2290:
2291: permit = all_opens_permitted;
2292: if (!permit) {
2293: for (i = 0; i < num_permitted_opens; i++)
2294: if (permitted_opens[i].port_to_connect == port &&
2295: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2296: permit = 1;
2297:
2298: }
2299: if (!permit) {
2300: log("Received request to connect to host %.100s port %d, "
2301: "but the request was denied.", host, port);
2302: return -1;
2303: }
2304: return connect_to(host, port);
2305: }
2306:
1.121 markus 2307: /* -- X11 forwarding */
1.1 deraadt 2308:
1.27 markus 2309: /*
2310: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2311: * Returns a suitable display number for the DISPLAY variable, or -1 if
2312: * an error occurs.
1.27 markus 2313: */
1.141 stevesk 2314: int
1.163 stevesk 2315: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.149 markus 2316: int single_connection)
1.1 deraadt 2317: {
1.149 markus 2318: Channel *nc = NULL;
1.31 markus 2319: int display_number, sock;
2320: u_short port;
1.35 markus 2321: struct addrinfo hints, *ai, *aitop;
2322: char strport[NI_MAXSERV];
2323: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2324:
1.33 markus 2325: for (display_number = x11_display_offset;
1.148 deraadt 2326: display_number < MAX_DISPLAYS;
2327: display_number++) {
1.25 markus 2328: port = 6000 + display_number;
1.35 markus 2329: memset(&hints, 0, sizeof(hints));
2330: hints.ai_family = IPv4or6;
1.163 stevesk 2331: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2332: hints.ai_socktype = SOCK_STREAM;
2333: snprintf(strport, sizeof strport, "%d", port);
2334: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2335: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2336: return -1;
1.25 markus 2337: }
1.35 markus 2338: for (ai = aitop; ai; ai = ai->ai_next) {
2339: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2340: continue;
2341: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2342: if (sock < 0) {
2343: error("socket: %.100s", strerror(errno));
1.141 stevesk 2344: return -1;
1.35 markus 2345: }
2346: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2347: debug("bind port %d: %.100s", port, strerror(errno));
2348: close(sock);
2349: for (n = 0; n < num_socks; n++) {
2350: close(socks[n]);
2351: }
2352: num_socks = 0;
2353: break;
2354: }
2355: socks[num_socks++] = sock;
2356: if (num_socks == NUM_SOCKS)
2357: break;
1.25 markus 2358: }
1.83 stevesk 2359: freeaddrinfo(aitop);
1.35 markus 2360: if (num_socks > 0)
2361: break;
1.25 markus 2362: }
2363: if (display_number >= MAX_DISPLAYS) {
2364: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2365: return -1;
1.25 markus 2366: }
2367: /* Start listening for connections on the socket. */
1.35 markus 2368: for (n = 0; n < num_socks; n++) {
2369: sock = socks[n];
2370: if (listen(sock, 5) < 0) {
2371: error("listen: %.100s", strerror(errno));
2372: close(sock);
1.141 stevesk 2373: return -1;
1.35 markus 2374: }
1.25 markus 2375: }
1.35 markus 2376:
2377: /* Allocate a channel for each socket. */
2378: for (n = 0; n < num_socks; n++) {
2379: sock = socks[n];
1.149 markus 2380: nc = channel_new("x11 listener",
1.51 markus 2381: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2382: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2383: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2384: nc->single_connection = single_connection;
1.35 markus 2385: }
1.1 deraadt 2386:
1.141 stevesk 2387: /* Return the display number for the DISPLAY environment variable. */
2388: return display_number;
1.1 deraadt 2389: }
2390:
1.127 itojun 2391: static int
1.77 markus 2392: connect_local_xsocket(u_int dnr)
1.1 deraadt 2393: {
1.25 markus 2394: int sock;
2395: struct sockaddr_un addr;
2396:
1.147 stevesk 2397: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2398: if (sock < 0)
2399: error("socket: %.100s", strerror(errno));
2400: memset(&addr, 0, sizeof(addr));
2401: addr.sun_family = AF_UNIX;
2402: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2403: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2404: return sock;
2405: close(sock);
1.25 markus 2406: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2407: return -1;
1.1 deraadt 2408: }
2409:
1.51 markus 2410: int
2411: x11_connect_display(void)
1.1 deraadt 2412: {
1.162 stevesk 2413: int display_number, sock = 0;
1.25 markus 2414: const char *display;
1.51 markus 2415: char buf[1024], *cp;
1.35 markus 2416: struct addrinfo hints, *ai, *aitop;
2417: char strport[NI_MAXSERV];
2418: int gaierr;
1.25 markus 2419:
2420: /* Try to open a socket for the local X server. */
2421: display = getenv("DISPLAY");
2422: if (!display) {
2423: error("DISPLAY not set.");
1.51 markus 2424: return -1;
1.25 markus 2425: }
1.27 markus 2426: /*
2427: * Now we decode the value of the DISPLAY variable and make a
2428: * connection to the real X server.
2429: */
2430:
2431: /*
2432: * Check if it is a unix domain socket. Unix domain displays are in
2433: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2434: */
1.25 markus 2435: if (strncmp(display, "unix:", 5) == 0 ||
2436: display[0] == ':') {
2437: /* Connect to the unix domain socket. */
2438: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2439: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2440: display);
1.51 markus 2441: return -1;
1.25 markus 2442: }
2443: /* Create a socket. */
2444: sock = connect_local_xsocket(display_number);
2445: if (sock < 0)
1.51 markus 2446: return -1;
1.25 markus 2447:
2448: /* OK, we now have a connection to the display. */
1.51 markus 2449: return sock;
1.25 markus 2450: }
1.27 markus 2451: /*
2452: * Connect to an inet socket. The DISPLAY value is supposedly
2453: * hostname:d[.s], where hostname may also be numeric IP address.
2454: */
1.145 stevesk 2455: strlcpy(buf, display, sizeof(buf));
1.25 markus 2456: cp = strchr(buf, ':');
2457: if (!cp) {
2458: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2459: return -1;
1.25 markus 2460: }
2461: *cp = 0;
1.27 markus 2462: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2463: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2464: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2465: display);
1.51 markus 2466: return -1;
1.25 markus 2467: }
1.35 markus 2468:
2469: /* Look up the host address */
2470: memset(&hints, 0, sizeof(hints));
2471: hints.ai_family = IPv4or6;
2472: hints.ai_socktype = SOCK_STREAM;
2473: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2474: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2475: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2476: return -1;
1.25 markus 2477: }
1.35 markus 2478: for (ai = aitop; ai; ai = ai->ai_next) {
2479: /* Create a socket. */
2480: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2481: if (sock < 0) {
2482: debug("socket: %.100s", strerror(errno));
1.41 markus 2483: continue;
2484: }
2485: /* Connect it to the display. */
2486: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2487: debug("connect %.100s port %d: %.100s", buf,
2488: 6000 + display_number, strerror(errno));
2489: close(sock);
2490: continue;
2491: }
2492: /* Success */
2493: break;
1.35 markus 2494: }
2495: freeaddrinfo(aitop);
2496: if (!ai) {
1.49 markus 2497: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2498: strerror(errno));
1.51 markus 2499: return -1;
1.25 markus 2500: }
1.162 stevesk 2501: set_nodelay(sock);
1.51 markus 2502: return sock;
2503: }
2504:
2505: /*
2506: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2507: * the remote channel number. We should do whatever we want, and respond
2508: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2509: */
2510:
2511: void
1.154 markus 2512: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2513: {
1.113 markus 2514: Channel *c = NULL;
2515: int remote_id, sock = 0;
1.51 markus 2516: char *remote_host;
1.25 markus 2517:
1.113 markus 2518: debug("Received X11 open request.");
1.51 markus 2519:
1.113 markus 2520: remote_id = packet_get_int();
1.121 markus 2521:
2522: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2523: remote_host = packet_get_string(NULL);
1.51 markus 2524: } else {
2525: remote_host = xstrdup("unknown (remote did not supply name)");
2526: }
1.152 markus 2527: packet_check_eom();
1.25 markus 2528:
1.51 markus 2529: /* Obtain a connection to the real X display. */
2530: sock = x11_connect_display();
1.113 markus 2531: if (sock != -1) {
2532: /* Allocate a channel for this connection. */
2533: c = channel_new("connected x11 socket",
2534: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2535: remote_host, 1);
1.167 markus 2536: c->remote_id = remote_id;
2537: c->force_drain = 1;
1.113 markus 2538: }
2539: if (c == NULL) {
1.51 markus 2540: /* Send refusal to the remote host. */
2541: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2542: packet_put_int(remote_id);
1.51 markus 2543: } else {
2544: /* Send a confirmation to the remote host. */
2545: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2546: packet_put_int(remote_id);
2547: packet_put_int(c->self);
1.51 markus 2548: }
1.113 markus 2549: packet_send();
1.72 markus 2550: }
2551:
2552: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2553: void
1.154 markus 2554: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2555: {
2556: int rchan = packet_get_int();
1.143 deraadt 2557: switch (type) {
1.72 markus 2558: case SSH_SMSG_AGENT_OPEN:
2559: error("Warning: ssh server tried agent forwarding.");
2560: break;
2561: case SSH_SMSG_X11_OPEN:
2562: error("Warning: ssh server tried X11 forwarding.");
2563: break;
2564: default:
1.154 markus 2565: error("deny_input_open: type %d", type);
1.72 markus 2566: break;
2567: }
2568: error("Warning: this is probably a break in attempt by a malicious server.");
2569: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2570: packet_put_int(rchan);
2571: packet_send();
1.1 deraadt 2572: }
2573:
1.27 markus 2574: /*
2575: * Requests forwarding of X11 connections, generates fake authentication
2576: * data, and enables authentication spoofing.
1.121 markus 2577: * This should be called in the client only.
1.27 markus 2578: */
1.49 markus 2579: void
1.51 markus 2580: x11_request_forwarding_with_spoofing(int client_session_id,
2581: const char *proto, const char *data)
1.1 deraadt 2582: {
1.77 markus 2583: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2584: u_int i, value, len;
1.25 markus 2585: char *new_data;
2586: int screen_number;
2587: const char *cp;
2588: u_int32_t rand = 0;
2589:
2590: cp = getenv("DISPLAY");
2591: if (cp)
2592: cp = strchr(cp, ':');
2593: if (cp)
2594: cp = strchr(cp, '.');
2595: if (cp)
2596: screen_number = atoi(cp + 1);
2597: else
2598: screen_number = 0;
2599:
2600: /* Save protocol name. */
2601: x11_saved_proto = xstrdup(proto);
2602:
1.27 markus 2603: /*
2604: * Extract real authentication data and generate fake data of the
2605: * same length.
2606: */
1.25 markus 2607: x11_saved_data = xmalloc(data_len);
2608: x11_fake_data = xmalloc(data_len);
2609: for (i = 0; i < data_len; i++) {
2610: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2611: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2612: if (i % 4 == 0)
2613: rand = arc4random();
2614: x11_saved_data[i] = value;
2615: x11_fake_data[i] = rand & 0xff;
2616: rand >>= 8;
2617: }
2618: x11_saved_data_len = data_len;
2619: x11_fake_data_len = data_len;
2620:
2621: /* Convert the fake data into hex. */
1.90 markus 2622: len = 2 * data_len + 1;
2623: new_data = xmalloc(len);
1.25 markus 2624: for (i = 0; i < data_len; i++)
1.90 markus 2625: snprintf(new_data + 2 * i, len - 2 * i,
2626: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2627:
2628: /* Send the request packet. */
1.51 markus 2629: if (compat20) {
2630: channel_request_start(client_session_id, "x11-req", 0);
2631: packet_put_char(0); /* XXX bool single connection */
2632: } else {
2633: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2634: }
2635: packet_put_cstring(proto);
2636: packet_put_cstring(new_data);
1.25 markus 2637: packet_put_int(screen_number);
2638: packet_send();
2639: packet_write_wait();
2640: xfree(new_data);
1.1 deraadt 2641: }
2642:
1.121 markus 2643:
2644: /* -- agent forwarding */
2645:
1.1 deraadt 2646: /* Sends a message to the server to request authentication fd forwarding. */
2647:
1.49 markus 2648: void
1.142 itojun 2649: auth_request_forwarding(void)
1.1 deraadt 2650: {
1.25 markus 2651: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2652: packet_send();
2653: packet_write_wait();
1.1 deraadt 2654: }
2655:
1.27 markus 2656: /*
2657: * Returns the name of the forwarded authentication socket. Returns NULL if
2658: * there is no forwarded authentication socket. The returned value points to
2659: * a static buffer.
2660: */
1.1 deraadt 2661:
1.25 markus 2662: char *
1.142 itojun 2663: auth_get_socket_name(void)
1.1 deraadt 2664: {
1.121 markus 2665: return auth_sock_name;
1.1 deraadt 2666: }
2667:
1.12 markus 2668: /* removes the agent forwarding socket */
2669:
1.49 markus 2670: void
1.123 markus 2671: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2672: {
1.123 markus 2673: struct passwd *pw = _pw;
2674:
1.122 markus 2675: if (auth_sock_name) {
1.123 markus 2676: temporarily_use_uid(pw);
1.122 markus 2677: unlink(auth_sock_name);
2678: rmdir(auth_sock_dir);
2679: auth_sock_name = NULL;
1.123 markus 2680: restore_uid();
1.122 markus 2681: }
1.12 markus 2682: }
2683:
1.27 markus 2684: /*
1.59 markus 2685: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2686: * This starts forwarding authentication requests.
2687: */
1.1 deraadt 2688:
1.59 markus 2689: int
1.25 markus 2690: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2691: {
1.113 markus 2692: Channel *nc;
2693: int sock;
1.25 markus 2694: struct sockaddr_un sunaddr;
2695:
1.121 markus 2696: if (auth_get_socket_name() != NULL) {
2697: error("authentication forwarding requested twice.");
2698: return 0;
2699: }
1.25 markus 2700:
2701: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2702: temporarily_use_uid(pw);
1.25 markus 2703:
2704: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2705: auth_sock_name = xmalloc(MAXPATHLEN);
2706: auth_sock_dir = xmalloc(MAXPATHLEN);
2707: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2708:
2709: /* Create private directory for socket */
1.121 markus 2710: if (mkdtemp(auth_sock_dir) == NULL) {
2711: packet_send_debug("Agent forwarding disabled: "
2712: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2713: restore_uid();
1.121 markus 2714: xfree(auth_sock_name);
2715: xfree(auth_sock_dir);
2716: auth_sock_name = NULL;
2717: auth_sock_dir = NULL;
1.59 markus 2718: return 0;
2719: }
1.121 markus 2720: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2721: auth_sock_dir, (int) getpid());
1.25 markus 2722:
1.122 markus 2723: /* delete agent socket on fatal() */
1.123 markus 2724: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2725:
1.25 markus 2726: /* Create the socket. */
2727: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2728: if (sock < 0)
2729: packet_disconnect("socket: %.100s", strerror(errno));
2730:
2731: /* Bind it to the name. */
2732: memset(&sunaddr, 0, sizeof(sunaddr));
2733: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2734: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2735:
2736: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2737: packet_disconnect("bind: %.100s", strerror(errno));
2738:
2739: /* Restore the privileged uid. */
2740: restore_uid();
2741:
2742: /* Start listening on the socket. */
2743: if (listen(sock, 5) < 0)
2744: packet_disconnect("listen: %.100s", strerror(errno));
2745:
2746: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2747: nc = channel_new("auth socket",
1.73 markus 2748: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2749: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2750: 0, xstrdup("auth socket"), 1);
1.121 markus 2751: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2752: return 1;
1.1 deraadt 2753: }
2754:
2755: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2756:
1.49 markus 2757: void
1.154 markus 2758: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2759: {
1.113 markus 2760: Channel *c = NULL;
2761: int remote_id, sock;
1.121 markus 2762: char *name;
1.41 markus 2763:
1.25 markus 2764: /* Read the remote channel number from the message. */
1.113 markus 2765: remote_id = packet_get_int();
1.152 markus 2766: packet_check_eom();
1.25 markus 2767:
1.27 markus 2768: /*
2769: * Get a connection to the local authentication agent (this may again
2770: * get forwarded).
2771: */
1.25 markus 2772: sock = ssh_get_authentication_socket();
2773:
1.27 markus 2774: /*
2775: * If we could not connect the agent, send an error message back to
2776: * the server. This should never happen unless the agent dies,
2777: * because authentication forwarding is only enabled if we have an
2778: * agent.
2779: */
1.113 markus 2780: if (sock >= 0) {
1.121 markus 2781: name = xstrdup("authentication agent connection");
2782: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2783: -1, 0, 0, 0, name, 1);
1.167 markus 2784: c->remote_id = remote_id;
2785: c->force_drain = 1;
1.113 markus 2786: }
2787: if (c == NULL) {
1.25 markus 2788: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2789: packet_put_int(remote_id);
2790: } else {
2791: /* Send a confirmation to the remote host. */
2792: debug("Forwarding authentication connection.");
2793: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2794: packet_put_int(remote_id);
2795: packet_put_int(c->self);
1.25 markus 2796: }
2797: packet_send();
1.1 deraadt 2798: }