Annotation of src/usr.bin/ssh/channels.c, Revision 1.172.2.1
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.156 markus 16: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.172.2.1! jason 42: RCSID("$OpenBSD: channels.c,v 1.173 2002/04/22 21:04:52 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:
1.171 markus 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) {
1.172 markus 709: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
710: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
711: c->self, c->efd, buffer_len(&c->extended));
712: else
713: chan_obuf_empty(c);
1.44 markus 714: }
715: }
716: /** XXX check close conditions, too */
1.157 markus 717: if (compat20 && c->efd != -1) {
1.44 markus 718: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
719: buffer_len(&c->extended) > 0)
720: FD_SET(c->efd, writeset);
1.172 markus 721: else if (!(c->flags & CHAN_EOF_SENT) &&
722: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 723: buffer_len(&c->extended) < c->remote_window)
724: FD_SET(c->efd, readset);
725: }
726: }
727:
1.127 itojun 728: static void
1.41 markus 729: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
730: {
731: if (buffer_len(&c->input) == 0) {
732: packet_start(SSH_MSG_CHANNEL_CLOSE);
733: packet_put_int(c->remote_id);
734: packet_send();
735: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 736: debug("channel %d: closing after input drain.", c->self);
1.41 markus 737: }
738: }
739:
1.127 itojun 740: static void
1.41 markus 741: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
742: {
743: if (buffer_len(&c->output) == 0)
1.113 markus 744: chan_mark_dead(c);
1.49 markus 745: else
1.41 markus 746: FD_SET(c->sock, writeset);
747: }
748:
749: /*
750: * This is a special state for X11 authentication spoofing. An opened X11
751: * connection (when authentication spoofing is being done) remains in this
752: * state until the first packet has been completely read. The authentication
753: * data in that packet is then substituted by the real data if it matches the
754: * fake data, and the channel is put into normal mode.
1.51 markus 755: * XXX All this happens at the client side.
1.121 markus 756: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 757: */
1.127 itojun 758: static int
1.121 markus 759: x11_open_helper(Buffer *b)
1.1 deraadt 760: {
1.77 markus 761: u_char *ucp;
762: u_int proto_len, data_len;
1.25 markus 763:
1.41 markus 764: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 765: if (buffer_len(b) < 12)
1.41 markus 766: return 0;
767:
768: /* Parse the lengths of variable-length fields. */
1.155 stevesk 769: ucp = buffer_ptr(b);
1.41 markus 770: if (ucp[0] == 0x42) { /* Byte order MSB first. */
771: proto_len = 256 * ucp[6] + ucp[7];
772: data_len = 256 * ucp[8] + ucp[9];
773: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
774: proto_len = ucp[6] + 256 * ucp[7];
775: data_len = ucp[8] + 256 * ucp[9];
776: } else {
777: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 778: ucp[0]);
1.41 markus 779: return -1;
780: }
781:
782: /* Check if the whole packet is in buffer. */
1.121 markus 783: if (buffer_len(b) <
1.41 markus 784: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
785: return 0;
786:
787: /* Check if authentication protocol matches. */
788: if (proto_len != strlen(x11_saved_proto) ||
789: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
790: debug("X11 connection uses different authentication protocol.");
791: return -1;
792: }
793: /* Check if authentication data matches our fake data. */
794: if (data_len != x11_fake_data_len ||
795: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
796: x11_fake_data, x11_fake_data_len) != 0) {
797: debug("X11 auth data does not match fake data.");
798: return -1;
799: }
800: /* Check fake data length */
801: if (x11_fake_data_len != x11_saved_data_len) {
802: error("X11 fake_data_len %d != saved_data_len %d",
803: x11_fake_data_len, x11_saved_data_len);
804: return -1;
805: }
806: /*
807: * Received authentication protocol and data match
808: * our fake data. Substitute the fake data with real
809: * data.
810: */
811: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
812: x11_saved_data, x11_saved_data_len);
813: return 1;
814: }
815:
1.127 itojun 816: static void
1.41 markus 817: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
818: {
1.121 markus 819: int ret = x11_open_helper(&c->output);
1.41 markus 820: if (ret == 1) {
821: /* Start normal processing for the channel. */
822: c->type = SSH_CHANNEL_OPEN;
1.47 markus 823: channel_pre_open_13(c, readset, writeset);
1.41 markus 824: } else if (ret == -1) {
825: /*
826: * We have received an X11 connection that has bad
827: * authentication information.
828: */
1.98 millert 829: log("X11 connection rejected because of wrong authentication.");
1.41 markus 830: buffer_clear(&c->input);
831: buffer_clear(&c->output);
1.132 markus 832: channel_close_fd(&c->sock);
1.41 markus 833: c->sock = -1;
834: c->type = SSH_CHANNEL_CLOSED;
835: packet_start(SSH_MSG_CHANNEL_CLOSE);
836: packet_put_int(c->remote_id);
837: packet_send();
838: }
839: }
1.25 markus 840:
1.127 itojun 841: static void
1.51 markus 842: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 843: {
1.121 markus 844: int ret = x11_open_helper(&c->output);
1.133 markus 845:
846: /* c->force_drain = 1; */
847:
1.41 markus 848: if (ret == 1) {
849: c->type = SSH_CHANNEL_OPEN;
1.157 markus 850: channel_pre_open(c, readset, writeset);
1.41 markus 851: } else if (ret == -1) {
1.156 markus 852: log("X11 connection rejected because of wrong authentication.");
1.41 markus 853: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 854: chan_read_failed(c);
855: buffer_clear(&c->input);
856: chan_ibuf_empty(c);
857: buffer_clear(&c->output);
858: /* for proto v1, the peer will send an IEOF */
859: if (compat20)
860: chan_write_failed(c);
861: else
862: c->type = SSH_CHANNEL_OPEN;
1.41 markus 863: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
864: }
865: }
1.25 markus 866:
1.104 markus 867: /* try to decode a socks4 header */
1.127 itojun 868: static int
1.104 markus 869: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 870: {
871: u_char *p, *host;
1.109 markus 872: int len, have, i, found;
1.148 deraadt 873: char username[256];
1.103 markus 874: struct {
875: u_int8_t version;
876: u_int8_t command;
877: u_int16_t dest_port;
1.104 markus 878: struct in_addr dest_addr;
1.103 markus 879: } s4_req, s4_rsp;
880:
1.104 markus 881: debug2("channel %d: decode socks4", c->self);
1.109 markus 882:
883: have = buffer_len(&c->input);
884: len = sizeof(s4_req);
885: if (have < len)
886: return 0;
887: p = buffer_ptr(&c->input);
888: for (found = 0, i = len; i < have; i++) {
889: if (p[i] == '\0') {
890: found = 1;
891: break;
892: }
893: if (i > 1024) {
894: /* the peer is probably sending garbage */
895: debug("channel %d: decode socks4: too long",
896: c->self);
897: return -1;
898: }
899: }
900: if (!found)
901: return 0;
1.103 markus 902: buffer_get(&c->input, (char *)&s4_req.version, 1);
903: buffer_get(&c->input, (char *)&s4_req.command, 1);
904: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 905: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 906: have = buffer_len(&c->input);
1.103 markus 907: p = buffer_ptr(&c->input);
908: len = strlen(p);
1.106 markus 909: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 910: if (len > have)
1.104 markus 911: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 912: c->self, len, have);
913: strlcpy(username, p, sizeof(username));
914: buffer_consume(&c->input, len);
915: buffer_consume(&c->input, 1); /* trailing '\0' */
916:
1.104 markus 917: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 918: strlcpy(c->path, host, sizeof(c->path));
919: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 920:
1.106 markus 921: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
922: c->self, host, c->host_port, s4_req.command);
1.103 markus 923:
1.104 markus 924: if (s4_req.command != 1) {
925: debug("channel %d: cannot handle: socks4 cn %d",
926: c->self, s4_req.command);
927: return -1;
1.103 markus 928: }
1.104 markus 929: s4_rsp.version = 0; /* vn: 0 for reply */
930: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 931: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 932: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 933: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 934: return 1;
935: }
936:
937: /* dynamic port forwarding */
1.127 itojun 938: static void
1.104 markus 939: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
940: {
941: u_char *p;
942: int have, ret;
1.103 markus 943:
1.104 markus 944: have = buffer_len(&c->input);
1.137 markus 945: c->delayed = 0;
1.104 markus 946: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 947: /* buffer_dump(&c->input); */
1.104 markus 948: /* check if the fixed size part of the packet is in buffer. */
949: if (have < 4) {
950: /* need more */
951: FD_SET(c->sock, readset);
952: return;
953: }
954: /* try to guess the protocol */
955: p = buffer_ptr(&c->input);
956: switch (p[0]) {
957: case 0x04:
958: ret = channel_decode_socks4(c, readset, writeset);
959: break;
960: default:
961: ret = -1;
962: break;
963: }
964: if (ret < 0) {
1.113 markus 965: chan_mark_dead(c);
1.104 markus 966: } else if (ret == 0) {
967: debug2("channel %d: pre_dynamic: need more", c->self);
968: /* need more */
969: FD_SET(c->sock, readset);
970: } else {
971: /* switch to the next state */
972: c->type = SSH_CHANNEL_OPENING;
973: port_open_helper(c, "direct-tcpip");
974: }
1.103 markus 975: }
976:
1.41 markus 977: /* This is our fake X11 server socket. */
1.127 itojun 978: static void
1.41 markus 979: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
980: {
1.113 markus 981: Channel *nc;
1.41 markus 982: struct sockaddr addr;
1.162 stevesk 983: int newsock;
1.41 markus 984: socklen_t addrlen;
1.85 markus 985: char buf[16384], *remote_ipaddr;
1.51 markus 986: int remote_port;
1.25 markus 987:
1.41 markus 988: if (FD_ISSET(c->sock, readset)) {
989: debug("X11 connection requested.");
990: addrlen = sizeof(addr);
991: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 992: if (c->single_connection) {
993: debug("single_connection: closing X11 listener.");
994: channel_close_fd(&c->sock);
995: chan_mark_dead(c);
996: }
1.41 markus 997: if (newsock < 0) {
998: error("accept: %.100s", strerror(errno));
999: return;
1000: }
1.162 stevesk 1001: set_nodelay(newsock);
1.85 markus 1002: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1003: remote_port = get_peer_port(newsock);
1.41 markus 1004: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1005: remote_ipaddr, remote_port);
1.51 markus 1006:
1.113 markus 1007: nc = channel_new("accepted x11 socket",
1.51 markus 1008: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1009: c->local_window_max, c->local_maxpacket,
1.71 markus 1010: 0, xstrdup(buf), 1);
1.51 markus 1011: if (compat20) {
1012: packet_start(SSH2_MSG_CHANNEL_OPEN);
1013: packet_put_cstring("x11");
1.113 markus 1014: packet_put_int(nc->self);
1.149 markus 1015: packet_put_int(nc->local_window_max);
1016: packet_put_int(nc->local_maxpacket);
1.85 markus 1017: /* originator ipaddr and port */
1018: packet_put_cstring(remote_ipaddr);
1.57 markus 1019: if (datafellows & SSH_BUG_X11FWD) {
1020: debug("ssh2 x11 bug compat mode");
1021: } else {
1022: packet_put_int(remote_port);
1023: }
1.51 markus 1024: packet_send();
1025: } else {
1026: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1027: packet_put_int(nc->self);
1.121 markus 1028: if (packet_get_protocol_flags() &
1029: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1030: packet_put_cstring(buf);
1.51 markus 1031: packet_send();
1032: }
1.85 markus 1033: xfree(remote_ipaddr);
1.41 markus 1034: }
1035: }
1.25 markus 1036:
1.127 itojun 1037: static void
1.103 markus 1038: port_open_helper(Channel *c, char *rtype)
1039: {
1040: int direct;
1041: char buf[1024];
1042: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1043: u_short remote_port = get_peer_port(c->sock);
1044:
1045: direct = (strcmp(rtype, "direct-tcpip") == 0);
1046:
1047: snprintf(buf, sizeof buf,
1048: "%s: listening port %d for %.100s port %d, "
1049: "connect from %.200s port %d",
1050: rtype, c->listening_port, c->path, c->host_port,
1051: remote_ipaddr, remote_port);
1052:
1053: xfree(c->remote_name);
1054: c->remote_name = xstrdup(buf);
1055:
1056: if (compat20) {
1057: packet_start(SSH2_MSG_CHANNEL_OPEN);
1058: packet_put_cstring(rtype);
1059: packet_put_int(c->self);
1060: packet_put_int(c->local_window_max);
1061: packet_put_int(c->local_maxpacket);
1062: if (direct) {
1063: /* target host, port */
1064: packet_put_cstring(c->path);
1065: packet_put_int(c->host_port);
1066: } else {
1067: /* listen address, port */
1068: packet_put_cstring(c->path);
1069: packet_put_int(c->listening_port);
1070: }
1071: /* originator host and port */
1072: packet_put_cstring(remote_ipaddr);
1073: packet_put_int(remote_port);
1074: packet_send();
1075: } else {
1076: packet_start(SSH_MSG_PORT_OPEN);
1077: packet_put_int(c->self);
1078: packet_put_cstring(c->path);
1079: packet_put_int(c->host_port);
1.121 markus 1080: if (packet_get_protocol_flags() &
1081: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1082: packet_put_cstring(c->remote_name);
1083: packet_send();
1084: }
1085: xfree(remote_ipaddr);
1086: }
1087:
1.41 markus 1088: /*
1089: * This socket is listening for connections to a forwarded TCP/IP port.
1090: */
1.127 itojun 1091: static void
1.41 markus 1092: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1093: {
1.103 markus 1094: Channel *nc;
1.41 markus 1095: struct sockaddr addr;
1.113 markus 1096: int newsock, nextstate;
1.41 markus 1097: socklen_t addrlen;
1.103 markus 1098: char *rtype;
1.73 markus 1099:
1.41 markus 1100: if (FD_ISSET(c->sock, readset)) {
1101: debug("Connection to port %d forwarding "
1102: "to %.100s port %d requested.",
1103: c->listening_port, c->path, c->host_port);
1.103 markus 1104:
1.137 markus 1105: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1106: nextstate = SSH_CHANNEL_OPENING;
1107: rtype = "forwarded-tcpip";
1108: } else {
1109: if (c->host_port == 0) {
1110: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1111: rtype = "dynamic-tcpip";
1.137 markus 1112: } else {
1113: nextstate = SSH_CHANNEL_OPENING;
1114: rtype = "direct-tcpip";
1115: }
1116: }
1.103 markus 1117:
1.41 markus 1118: addrlen = sizeof(addr);
1119: newsock = accept(c->sock, &addr, &addrlen);
1120: if (newsock < 0) {
1121: error("accept: %.100s", strerror(errno));
1122: return;
1123: }
1.169 stevesk 1124: set_nodelay(newsock);
1.113 markus 1125: nc = channel_new(rtype,
1.103 markus 1126: nextstate, newsock, newsock, -1,
1.41 markus 1127: c->local_window_max, c->local_maxpacket,
1.103 markus 1128: 0, xstrdup(rtype), 1);
1129: nc->listening_port = c->listening_port;
1130: nc->host_port = c->host_port;
1131: strlcpy(nc->path, c->path, sizeof(nc->path));
1132:
1.137 markus 1133: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1134: /*
1135: * do not call the channel_post handler until
1136: * this flag has been reset by a pre-handler.
1137: * otherwise the FD_ISSET calls might overflow
1138: */
1139: nc->delayed = 1;
1140: } else {
1.103 markus 1141: port_open_helper(nc, rtype);
1.137 markus 1142: }
1.41 markus 1143: }
1144: }
1.25 markus 1145:
1.41 markus 1146: /*
1147: * This is the authentication agent socket listening for connections from
1148: * clients.
1149: */
1.127 itojun 1150: static void
1.41 markus 1151: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1152: {
1.113 markus 1153: Channel *nc;
1.121 markus 1154: char *name;
1.113 markus 1155: int newsock;
1.41 markus 1156: struct sockaddr addr;
1157: socklen_t addrlen;
1.25 markus 1158:
1.41 markus 1159: if (FD_ISSET(c->sock, readset)) {
1160: addrlen = sizeof(addr);
1161: newsock = accept(c->sock, &addr, &addrlen);
1162: if (newsock < 0) {
1163: error("accept from auth socket: %.100s", strerror(errno));
1164: return;
1165: }
1.121 markus 1166: name = xstrdup("accepted auth socket");
1.113 markus 1167: nc = channel_new("accepted auth socket",
1.73 markus 1168: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1169: c->local_window_max, c->local_maxpacket,
1.121 markus 1170: 0, name, 1);
1.73 markus 1171: if (compat20) {
1172: packet_start(SSH2_MSG_CHANNEL_OPEN);
1173: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1174: packet_put_int(nc->self);
1.73 markus 1175: packet_put_int(c->local_window_max);
1176: packet_put_int(c->local_maxpacket);
1177: } else {
1178: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1179: packet_put_int(nc->self);
1.73 markus 1180: }
1.41 markus 1181: packet_send();
1182: }
1183: }
1.25 markus 1184:
1.127 itojun 1185: static void
1.75 markus 1186: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1187: {
1.114 markus 1188: int err = 0;
1.129 stevesk 1189: socklen_t sz = sizeof(err);
1.114 markus 1190:
1.75 markus 1191: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1192: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1193: err = errno;
1194: error("getsockopt SO_ERROR failed");
1195: }
1196: if (err == 0) {
1197: debug("channel %d: connected", c->self);
1198: c->type = SSH_CHANNEL_OPEN;
1199: if (compat20) {
1200: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1201: packet_put_int(c->remote_id);
1202: packet_put_int(c->self);
1203: packet_put_int(c->local_window);
1204: packet_put_int(c->local_maxpacket);
1205: } else {
1206: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1207: packet_put_int(c->remote_id);
1208: packet_put_int(c->self);
1209: }
1.75 markus 1210: } else {
1.114 markus 1211: debug("channel %d: not connected: %s",
1212: c->self, strerror(err));
1213: if (compat20) {
1214: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1215: packet_put_int(c->remote_id);
1216: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1217: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1218: packet_put_cstring(strerror(err));
1219: packet_put_cstring("");
1220: }
1.75 markus 1221: } else {
1.114 markus 1222: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1223: packet_put_int(c->remote_id);
1.75 markus 1224: }
1.114 markus 1225: chan_mark_dead(c);
1.75 markus 1226: }
1.114 markus 1227: packet_send();
1.75 markus 1228: }
1229: }
1230:
1.127 itojun 1231: static int
1.41 markus 1232: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1233: {
1234: char buf[16*1024];
1235: int len;
1.25 markus 1236:
1.118 markus 1237: if (c->rfd != -1 &&
1.41 markus 1238: FD_ISSET(c->rfd, readset)) {
1239: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1240: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1241: return 1;
1.41 markus 1242: if (len <= 0) {
1.51 markus 1243: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1244: c->self, c->rfd, len);
1.104 markus 1245: if (c->type != SSH_CHANNEL_OPEN) {
1246: debug("channel %d: not open", c->self);
1.113 markus 1247: chan_mark_dead(c);
1.103 markus 1248: return -1;
1.104 markus 1249: } else if (compat13) {
1.158 markus 1250: buffer_clear(&c->output);
1.41 markus 1251: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1252: debug("channel %d: input draining.", c->self);
1.25 markus 1253: } else {
1.41 markus 1254: chan_read_failed(c);
1.25 markus 1255: }
1.41 markus 1256: return -1;
1257: }
1.143 deraadt 1258: if (c->input_filter != NULL) {
1.66 markus 1259: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1260: debug("channel %d: filter stops", c->self);
1.65 markus 1261: chan_read_failed(c);
1262: }
1263: } else {
1264: buffer_append(&c->input, buf, len);
1265: }
1.41 markus 1266: }
1267: return 1;
1268: }
1.127 itojun 1269: static int
1.41 markus 1270: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1271: {
1.95 markus 1272: struct termios tio;
1.134 markus 1273: u_char *data;
1274: u_int dlen;
1.41 markus 1275: int len;
1.25 markus 1276:
1.41 markus 1277: /* Send buffered output data to the socket. */
1.118 markus 1278: if (c->wfd != -1 &&
1.41 markus 1279: FD_ISSET(c->wfd, writeset) &&
1280: buffer_len(&c->output) > 0) {
1.134 markus 1281: data = buffer_ptr(&c->output);
1282: dlen = buffer_len(&c->output);
1283: len = write(c->wfd, data, dlen);
1.53 markus 1284: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1285: return 1;
1.41 markus 1286: if (len <= 0) {
1.104 markus 1287: if (c->type != SSH_CHANNEL_OPEN) {
1288: debug("channel %d: not open", c->self);
1.113 markus 1289: chan_mark_dead(c);
1.104 markus 1290: return -1;
1291: } else if (compat13) {
1.158 markus 1292: buffer_clear(&c->output);
1.121 markus 1293: debug("channel %d: input draining.", c->self);
1.41 markus 1294: c->type = SSH_CHANNEL_INPUT_DRAINING;
1295: } else {
1296: chan_write_failed(c);
1297: }
1298: return -1;
1.91 markus 1299: }
1.134 markus 1300: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1301: if (tcgetattr(c->wfd, &tio) == 0 &&
1302: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1303: /*
1304: * Simulate echo to reduce the impact of
1.96 markus 1305: * traffic analysis. We need to match the
1.95 markus 1306: * size of a SSH2_MSG_CHANNEL_DATA message
1307: * (4 byte channel id + data)
1.91 markus 1308: */
1.95 markus 1309: packet_send_ignore(4 + len);
1.91 markus 1310: packet_send();
1311: }
1.25 markus 1312: }
1.41 markus 1313: buffer_consume(&c->output, len);
1.44 markus 1314: if (compat20 && len > 0) {
1315: c->local_consumed += len;
1316: }
1317: }
1318: return 1;
1319: }
1.127 itojun 1320: static int
1.44 markus 1321: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1322: {
1323: char buf[16*1024];
1324: int len;
1325:
1.45 markus 1326: /** XXX handle drain efd, too */
1.44 markus 1327: if (c->efd != -1) {
1328: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1329: FD_ISSET(c->efd, writeset) &&
1330: buffer_len(&c->extended) > 0) {
1331: len = write(c->efd, buffer_ptr(&c->extended),
1332: buffer_len(&c->extended));
1.70 markus 1333: debug2("channel %d: written %d to efd %d",
1.44 markus 1334: c->self, len, c->efd);
1.93 markus 1335: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1336: return 1;
1337: if (len <= 0) {
1338: debug2("channel %d: closing write-efd %d",
1339: c->self, c->efd);
1.132 markus 1340: channel_close_fd(&c->efd);
1.93 markus 1341: } else {
1.44 markus 1342: buffer_consume(&c->extended, len);
1343: c->local_consumed += len;
1344: }
1345: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1346: FD_ISSET(c->efd, readset)) {
1347: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1348: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1349: c->self, len, c->efd);
1.93 markus 1350: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1351: return 1;
1352: if (len <= 0) {
1353: debug2("channel %d: closing read-efd %d",
1.45 markus 1354: c->self, c->efd);
1.132 markus 1355: channel_close_fd(&c->efd);
1.93 markus 1356: } else {
1.44 markus 1357: buffer_append(&c->extended, buf, len);
1.93 markus 1358: }
1.44 markus 1359: }
1360: }
1361: return 1;
1362: }
1.127 itojun 1363: static int
1.93 markus 1364: channel_check_window(Channel *c)
1.44 markus 1365: {
1.104 markus 1366: if (c->type == SSH_CHANNEL_OPEN &&
1367: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1368: c->local_window < c->local_window_max/2 &&
1369: c->local_consumed > 0) {
1370: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1371: packet_put_int(c->remote_id);
1372: packet_put_int(c->local_consumed);
1373: packet_send();
1.70 markus 1374: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1375: c->self, c->local_window,
1376: c->local_consumed);
1377: c->local_window += c->local_consumed;
1378: c->local_consumed = 0;
1.1 deraadt 1379: }
1.41 markus 1380: return 1;
1.1 deraadt 1381: }
1382:
1.127 itojun 1383: static void
1.157 markus 1384: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1385: {
1.137 markus 1386: if (c->delayed)
1387: return;
1.41 markus 1388: channel_handle_rfd(c, readset, writeset);
1389: channel_handle_wfd(c, readset, writeset);
1.157 markus 1390: if (!compat20)
1.137 markus 1391: return;
1.44 markus 1392: channel_handle_efd(c, readset, writeset);
1.93 markus 1393: channel_check_window(c);
1.44 markus 1394: }
1395:
1.127 itojun 1396: static void
1.41 markus 1397: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1398: {
1.41 markus 1399: int len;
1400: /* Send buffered output data to the socket. */
1401: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1402: len = write(c->sock, buffer_ptr(&c->output),
1403: buffer_len(&c->output));
1404: if (len <= 0)
1.158 markus 1405: buffer_clear(&c->output);
1.41 markus 1406: else
1407: buffer_consume(&c->output, len);
1408: }
1409: }
1.25 markus 1410:
1.127 itojun 1411: static void
1.44 markus 1412: channel_handler_init_20(void)
1413: {
1.157 markus 1414: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1415: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1416: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1417: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1418: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1419: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1420: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1421: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1422:
1.157 markus 1423: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1424: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1425: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1426: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1427: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1428: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1429: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1430: }
1431:
1.127 itojun 1432: static void
1.41 markus 1433: channel_handler_init_13(void)
1434: {
1435: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1436: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1437: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1438: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1439: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1440: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1441: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1442: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1443: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1444:
1.157 markus 1445: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1446: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1447: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1448: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1449: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1450: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1451: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1452: }
1.25 markus 1453:
1.127 itojun 1454: static void
1.41 markus 1455: channel_handler_init_15(void)
1456: {
1.157 markus 1457: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1458: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1459: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1460: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1461: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1462: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1463: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1464:
1.41 markus 1465: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1466: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1467: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1468: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1469: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1470: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1471: }
1.27 markus 1472:
1.127 itojun 1473: static void
1.41 markus 1474: channel_handler_init(void)
1475: {
1476: int i;
1.148 deraadt 1477: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1478: channel_pre[i] = NULL;
1479: channel_post[i] = NULL;
1480: }
1.44 markus 1481: if (compat20)
1482: channel_handler_init_20();
1483: else if (compat13)
1.41 markus 1484: channel_handler_init_13();
1485: else
1486: channel_handler_init_15();
1487: }
1.25 markus 1488:
1.140 markus 1489: /* gc dead channels */
1490: static void
1491: channel_garbage_collect(Channel *c)
1492: {
1493: if (c == NULL)
1494: return;
1495: if (c->detach_user != NULL) {
1496: if (!chan_is_dead(c, 0))
1497: return;
1498: debug("channel %d: gc: notify user", c->self);
1499: c->detach_user(c->self, NULL);
1500: /* if we still have a callback */
1501: if (c->detach_user != NULL)
1502: return;
1503: debug("channel %d: gc: user detached", c->self);
1504: }
1505: if (!chan_is_dead(c, 1))
1506: return;
1507: debug("channel %d: garbage collecting", c->self);
1508: channel_free(c);
1509: }
1510:
1.127 itojun 1511: static void
1.41 markus 1512: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1513: {
1514: static int did_init = 0;
1515: int i;
1516: Channel *c;
1.25 markus 1517:
1.41 markus 1518: if (!did_init) {
1519: channel_handler_init();
1520: did_init = 1;
1521: }
1522: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1523: c = channels[i];
1524: if (c == NULL)
1.41 markus 1525: continue;
1.118 markus 1526: if (ftab[c->type] != NULL)
1527: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1528: channel_garbage_collect(c);
1.1 deraadt 1529: }
1530: }
1531:
1.121 markus 1532: /*
1533: * Allocate/update select bitmasks and add any bits relevant to channels in
1534: * select bitmasks.
1535: */
1.49 markus 1536: void
1.100 markus 1537: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1538: int *nallocp, int rekeying)
1.41 markus 1539: {
1.84 markus 1540: int n;
1541: u_int sz;
1542:
1543: n = MAX(*maxfdp, channel_max_fd);
1544:
1545: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1546: /* perhaps check sz < nalloc/2 and shrink? */
1547: if (*readsetp == NULL || sz > *nallocp) {
1548: *readsetp = xrealloc(*readsetp, sz);
1549: *writesetp = xrealloc(*writesetp, sz);
1550: *nallocp = sz;
1.84 markus 1551: }
1.132 markus 1552: *maxfdp = n;
1.84 markus 1553: memset(*readsetp, 0, sz);
1554: memset(*writesetp, 0, sz);
1555:
1.100 markus 1556: if (!rekeying)
1557: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1558: }
1559:
1.121 markus 1560: /*
1561: * After select, perform any appropriate operations for channels which have
1562: * events pending.
1563: */
1.49 markus 1564: void
1.41 markus 1565: channel_after_select(fd_set * readset, fd_set * writeset)
1566: {
1567: channel_handler(channel_post, readset, writeset);
1568: }
1569:
1.121 markus 1570:
1.84 markus 1571: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1572:
1.49 markus 1573: void
1.142 itojun 1574: channel_output_poll(void)
1.1 deraadt 1575: {
1.25 markus 1576: int len, i;
1.41 markus 1577: Channel *c;
1.1 deraadt 1578:
1.25 markus 1579: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1580: c = channels[i];
1581: if (c == NULL)
1582: continue;
1.37 markus 1583:
1.121 markus 1584: /*
1585: * We are only interested in channels that can have buffered
1586: * incoming data.
1587: */
1.37 markus 1588: if (compat13) {
1.41 markus 1589: if (c->type != SSH_CHANNEL_OPEN &&
1590: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1591: continue;
1592: } else {
1.41 markus 1593: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1594: continue;
1595: }
1.46 markus 1596: if (compat20 &&
1597: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1598: /* XXX is this true? */
1.140 markus 1599: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1600: continue;
1601: }
1.25 markus 1602:
1603: /* Get the amount of buffered data for this channel. */
1.93 markus 1604: if ((c->istate == CHAN_INPUT_OPEN ||
1605: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1606: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1607: /*
1608: * Send some data for the other side over the secure
1609: * connection.
1610: */
1.44 markus 1611: if (compat20) {
1612: if (len > c->remote_window)
1613: len = c->remote_window;
1614: if (len > c->remote_maxpacket)
1615: len = c->remote_maxpacket;
1.25 markus 1616: } else {
1.44 markus 1617: if (packet_is_interactive()) {
1618: if (len > 1024)
1619: len = 512;
1620: } else {
1621: /* Keep the packets at reasonable size. */
1622: if (len > packet_get_maxsize()/2)
1623: len = packet_get_maxsize()/2;
1624: }
1.25 markus 1625: }
1.41 markus 1626: if (len > 0) {
1.44 markus 1627: packet_start(compat20 ?
1628: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1629: packet_put_int(c->remote_id);
1630: packet_put_string(buffer_ptr(&c->input), len);
1631: packet_send();
1632: buffer_consume(&c->input, len);
1633: c->remote_window -= len;
1634: }
1635: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1636: if (compat13)
1637: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1638: /*
1639: * input-buffer is empty and read-socket shutdown:
1.172 markus 1640: * tell peer, that we will not send more data: send IEOF.
1641: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1642: */
1.172 markus 1643: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1644: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1645: c->self, c->efd, buffer_len(&c->extended));
1646: else
1647: chan_ibuf_empty(c);
1.25 markus 1648: }
1.44 markus 1649: /* Send extended data, i.e. stderr */
1650: if (compat20 &&
1.172 markus 1651: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1652: c->remote_window > 0 &&
1653: (len = buffer_len(&c->extended)) > 0 &&
1654: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1655: debug2("channel %d: rwin %d elen %d euse %d",
1656: c->self, c->remote_window, buffer_len(&c->extended),
1657: c->extended_usage);
1.44 markus 1658: if (len > c->remote_window)
1659: len = c->remote_window;
1660: if (len > c->remote_maxpacket)
1661: len = c->remote_maxpacket;
1662: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1663: packet_put_int(c->remote_id);
1664: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1665: packet_put_string(buffer_ptr(&c->extended), len);
1666: packet_send();
1667: buffer_consume(&c->extended, len);
1668: c->remote_window -= len;
1.93 markus 1669: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1670: }
1.25 markus 1671: }
1.1 deraadt 1672: }
1673:
1.121 markus 1674:
1675: /* -- protocol input */
1.1 deraadt 1676:
1.49 markus 1677: void
1.154 markus 1678: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1679: {
1.37 markus 1680: int id;
1.25 markus 1681: char *data;
1.77 markus 1682: u_int data_len;
1.41 markus 1683: Channel *c;
1.25 markus 1684:
1685: /* Get the channel number and verify it. */
1.37 markus 1686: id = packet_get_int();
1.41 markus 1687: c = channel_lookup(id);
1688: if (c == NULL)
1.37 markus 1689: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1690:
1691: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1692: if (c->type != SSH_CHANNEL_OPEN &&
1693: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1694: return;
1695:
1696: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1697: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1698: return;
1699:
1700: /* Get the data. */
1701: data = packet_get_string(&data_len);
1.41 markus 1702:
1.143 deraadt 1703: if (compat20) {
1.44 markus 1704: if (data_len > c->local_maxpacket) {
1705: log("channel %d: rcvd big packet %d, maxpack %d",
1706: c->self, data_len, c->local_maxpacket);
1707: }
1708: if (data_len > c->local_window) {
1709: log("channel %d: rcvd too much data %d, win %d",
1710: c->self, data_len, c->local_window);
1711: xfree(data);
1712: return;
1713: }
1714: c->local_window -= data_len;
1715: }
1.152 markus 1716: packet_check_eom();
1.41 markus 1717: buffer_append(&c->output, data, data_len);
1.25 markus 1718: xfree(data);
1.1 deraadt 1719: }
1.121 markus 1720:
1.49 markus 1721: void
1.154 markus 1722: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1723: {
1724: int id;
1725: int tcode;
1726: char *data;
1.77 markus 1727: u_int data_len;
1.44 markus 1728: Channel *c;
1729:
1730: /* Get the channel number and verify it. */
1731: id = packet_get_int();
1732: c = channel_lookup(id);
1733:
1734: if (c == NULL)
1735: packet_disconnect("Received extended_data for bad channel %d.", id);
1736: if (c->type != SSH_CHANNEL_OPEN) {
1737: log("channel %d: ext data for non open", id);
1738: return;
1.172 markus 1739: }
1740: if (c->flags & CHAN_EOF_RCVD) {
1741: if (datafellows & SSH_BUG_EXTEOF)
1742: debug("channel %d: accepting ext data after eof", id);
1743: else
1744: packet_disconnect("Received extended_data after EOF "
1745: "on channel %d.", id);
1.44 markus 1746: }
1747: tcode = packet_get_int();
1748: if (c->efd == -1 ||
1749: c->extended_usage != CHAN_EXTENDED_WRITE ||
1750: tcode != SSH2_EXTENDED_DATA_STDERR) {
1751: log("channel %d: bad ext data", c->self);
1752: return;
1753: }
1754: data = packet_get_string(&data_len);
1.152 markus 1755: packet_check_eom();
1.44 markus 1756: if (data_len > c->local_window) {
1757: log("channel %d: rcvd too much extended_data %d, win %d",
1758: c->self, data_len, c->local_window);
1759: xfree(data);
1760: return;
1761: }
1.70 markus 1762: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1763: c->local_window -= data_len;
1764: buffer_append(&c->extended, data, data_len);
1765: xfree(data);
1766: }
1767:
1.49 markus 1768: void
1.154 markus 1769: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1770: {
1771: int id;
1772: Channel *c;
1773:
1774: id = packet_get_int();
1.152 markus 1775: packet_check_eom();
1.41 markus 1776: c = channel_lookup(id);
1777: if (c == NULL)
1778: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1779: chan_rcvd_ieof(c);
1.133 markus 1780:
1781: /* XXX force input close */
1.156 markus 1782: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1783: debug("channel %d: FORCE input drain", c->self);
1784: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1785: if (buffer_len(&c->input) == 0)
1786: chan_ibuf_empty(c);
1.133 markus 1787: }
1788:
1.41 markus 1789: }
1.1 deraadt 1790:
1.49 markus 1791: void
1.154 markus 1792: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1793: {
1.41 markus 1794: int id;
1795: Channel *c;
1.1 deraadt 1796:
1.41 markus 1797: id = packet_get_int();
1.152 markus 1798: packet_check_eom();
1.41 markus 1799: c = channel_lookup(id);
1800: if (c == NULL)
1801: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1802:
1803: /*
1804: * Send a confirmation that we have closed the channel and no more
1805: * data is coming for it.
1806: */
1.25 markus 1807: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1808: packet_put_int(c->remote_id);
1.25 markus 1809: packet_send();
1810:
1.27 markus 1811: /*
1812: * If the channel is in closed state, we have sent a close request,
1813: * and the other side will eventually respond with a confirmation.
1814: * Thus, we cannot free the channel here, because then there would be
1815: * no-one to receive the confirmation. The channel gets freed when
1816: * the confirmation arrives.
1817: */
1.41 markus 1818: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1819: /*
1820: * Not a closed channel - mark it as draining, which will
1821: * cause it to be freed later.
1822: */
1.158 markus 1823: buffer_clear(&c->input);
1.41 markus 1824: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1825: }
1.1 deraadt 1826: }
1827:
1.41 markus 1828: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1829: void
1.154 markus 1830: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1831: {
1832: int id = packet_get_int();
1833: Channel *c = channel_lookup(id);
1.151 markus 1834:
1.152 markus 1835: packet_check_eom();
1.41 markus 1836: if (c == NULL)
1837: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1838: chan_rcvd_oclose(c);
1839: }
1.1 deraadt 1840:
1.49 markus 1841: void
1.154 markus 1842: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1843: {
1.41 markus 1844: int id = packet_get_int();
1845: Channel *c = channel_lookup(id);
1.1 deraadt 1846:
1.152 markus 1847: packet_check_eom();
1.41 markus 1848: if (c == NULL)
1849: packet_disconnect("Received close confirmation for "
1850: "out-of-range channel %d.", id);
1851: if (c->type != SSH_CHANNEL_CLOSED)
1852: packet_disconnect("Received close confirmation for "
1853: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1854: channel_free(c);
1.1 deraadt 1855: }
1856:
1.49 markus 1857: void
1.154 markus 1858: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1859: {
1.41 markus 1860: int id, remote_id;
1861: Channel *c;
1.1 deraadt 1862:
1.41 markus 1863: id = packet_get_int();
1864: c = channel_lookup(id);
1.25 markus 1865:
1.41 markus 1866: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1867: packet_disconnect("Received open confirmation for "
1868: "non-opening channel %d.", id);
1869: remote_id = packet_get_int();
1.27 markus 1870: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1871: c->remote_id = remote_id;
1872: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1873:
1874: if (compat20) {
1875: c->remote_window = packet_get_int();
1876: c->remote_maxpacket = packet_get_int();
1.165 markus 1877: if (c->confirm) {
1.70 markus 1878: debug2("callback start");
1.165 markus 1879: c->confirm(c->self, NULL);
1.70 markus 1880: debug2("callback done");
1.44 markus 1881: }
1882: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1883: c->remote_window, c->remote_maxpacket);
1884: }
1.152 markus 1885: packet_check_eom();
1.1 deraadt 1886: }
1887:
1.127 itojun 1888: static char *
1.114 markus 1889: reason2txt(int reason)
1890: {
1.143 deraadt 1891: switch (reason) {
1.114 markus 1892: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1893: return "administratively prohibited";
1894: case SSH2_OPEN_CONNECT_FAILED:
1895: return "connect failed";
1896: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1897: return "unknown channel type";
1898: case SSH2_OPEN_RESOURCE_SHORTAGE:
1899: return "resource shortage";
1900: }
1.117 stevesk 1901: return "unknown reason";
1.114 markus 1902: }
1903:
1.49 markus 1904: void
1.154 markus 1905: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1906: {
1.86 markus 1907: int id, reason;
1908: char *msg = NULL, *lang = NULL;
1.41 markus 1909: Channel *c;
1910:
1911: id = packet_get_int();
1912: c = channel_lookup(id);
1.25 markus 1913:
1.41 markus 1914: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1915: packet_disconnect("Received open failure for "
1916: "non-opening channel %d.", id);
1.44 markus 1917: if (compat20) {
1.86 markus 1918: reason = packet_get_int();
1.110 markus 1919: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1920: msg = packet_get_string(NULL);
1921: lang = packet_get_string(NULL);
1922: }
1.114 markus 1923: log("channel %d: open failed: %s%s%s", id,
1924: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1925: if (msg != NULL)
1926: xfree(msg);
1927: if (lang != NULL)
1928: xfree(lang);
1.44 markus 1929: }
1.152 markus 1930: packet_check_eom();
1.25 markus 1931: /* Free the channel. This will also close the socket. */
1.113 markus 1932: channel_free(c);
1.44 markus 1933: }
1934:
1.121 markus 1935: void
1.154 markus 1936: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1937: {
1938: Channel *c;
1939: int id, adjust;
1940:
1941: if (!compat20)
1942: return;
1943:
1944: /* Get the channel number and verify it. */
1945: id = packet_get_int();
1946: c = channel_lookup(id);
1.1 deraadt 1947:
1.121 markus 1948: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1949: log("Received window adjust for "
1950: "non-open channel %d.", id);
1951: return;
1952: }
1953: adjust = packet_get_int();
1.152 markus 1954: packet_check_eom();
1.121 markus 1955: debug2("channel %d: rcvd adjust %d", id, adjust);
1956: c->remote_window += adjust;
1957: }
1.1 deraadt 1958:
1.121 markus 1959: void
1.154 markus 1960: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1961: {
1.121 markus 1962: Channel *c = NULL;
1963: u_short host_port;
1964: char *host, *originator_string;
1965: int remote_id, sock = -1;
1966:
1967: remote_id = packet_get_int();
1968: host = packet_get_string(NULL);
1969: host_port = packet_get_int();
1.25 markus 1970:
1.121 markus 1971: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1972: originator_string = packet_get_string(NULL);
1973: } else {
1974: originator_string = xstrdup("unknown (remote did not supply name)");
1975: }
1.152 markus 1976: packet_check_eom();
1.121 markus 1977: sock = channel_connect_to(host, host_port);
1978: if (sock != -1) {
1979: c = channel_new("connected socket",
1980: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1981: originator_string, 1);
1.167 markus 1982: c->remote_id = remote_id;
1.25 markus 1983: }
1.121 markus 1984: if (c == NULL) {
1985: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1986: packet_put_int(remote_id);
1987: packet_send();
1988: }
1989: xfree(host);
1.1 deraadt 1990: }
1991:
1.121 markus 1992:
1993: /* -- tcp forwarding */
1.135 markus 1994:
1995: void
1996: channel_set_af(int af)
1997: {
1998: IPv4or6 = af;
1999: }
1.121 markus 2000:
1.160 markus 2001: static int
2002: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2003: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2004: {
1.113 markus 2005: Channel *c;
1.160 markus 2006: int success, sock, on = 1;
1.35 markus 2007: struct addrinfo hints, *ai, *aitop;
1.160 markus 2008: const char *host;
1.35 markus 2009: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.28 markus 2010: struct linger linger;
1.25 markus 2011:
1.87 markus 2012: success = 0;
1.160 markus 2013: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2014: listen_addr : host_to_connect;
1.87 markus 2015:
1.160 markus 2016: if (host == NULL) {
2017: error("No forward host name.");
2018: return success;
1.73 markus 2019: }
1.113 markus 2020: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2021: error("Forward host name too long.");
2022: return success;
2023: }
1.25 markus 2024:
1.28 markus 2025: /*
1.35 markus 2026: * getaddrinfo returns a loopback address if the hostname is
2027: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2028: */
1.35 markus 2029: memset(&hints, 0, sizeof(hints));
2030: hints.ai_family = IPv4or6;
2031: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2032: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2033: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2034: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2035: packet_disconnect("getaddrinfo: fatal error");
2036:
2037: for (ai = aitop; ai; ai = ai->ai_next) {
2038: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2039: continue;
2040: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2041: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2042: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2043: continue;
2044: }
2045: /* Create a port to listen for the host. */
2046: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2047: if (sock < 0) {
2048: /* this is no error since kernel may not support ipv6 */
2049: verbose("socket: %.100s", strerror(errno));
2050: continue;
2051: }
2052: /*
2053: * Set socket options. We would like the socket to disappear
2054: * as soon as it has been closed for whatever reason.
2055: */
1.170 stevesk 2056: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
1.35 markus 2057: linger.l_onoff = 1;
2058: linger.l_linger = 5;
1.170 stevesk 2059: setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
1.35 markus 2060: debug("Local forwarding listening on %s port %s.", ntop, strport);
2061:
2062: /* Bind the socket to the address. */
2063: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2064: /* address can be in use ipv6 address is already bound */
2065: verbose("bind: %.100s", strerror(errno));
2066: close(sock);
2067: continue;
2068: }
2069: /* Start listening for connections on the socket. */
2070: if (listen(sock, 5) < 0) {
2071: error("listen: %.100s", strerror(errno));
2072: close(sock);
2073: continue;
2074: }
2075: /* Allocate a channel number for the socket. */
1.121 markus 2076: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2077: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2078: 0, xstrdup("port listener"), 1);
1.113 markus 2079: strlcpy(c->path, host, sizeof(c->path));
2080: c->host_port = port_to_connect;
2081: c->listening_port = listen_port;
1.35 markus 2082: success = 1;
2083: }
2084: if (success == 0)
1.160 markus 2085: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2086: listen_port);
1.35 markus 2087: freeaddrinfo(aitop);
1.87 markus 2088: return success;
1.25 markus 2089: }
1.1 deraadt 2090:
1.160 markus 2091: /* protocol local port fwd, used by ssh (and sshd in v1) */
2092: int
2093: channel_setup_local_fwd_listener(u_short listen_port,
2094: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2095: {
2096: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2097: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2098: }
2099:
2100: /* protocol v2 remote port fwd, used by sshd */
2101: int
2102: channel_setup_remote_fwd_listener(const char *listen_address,
2103: u_short listen_port, int gateway_ports)
2104: {
2105: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2106: listen_address, listen_port, NULL, 0, gateway_ports);
2107: }
2108:
1.27 markus 2109: /*
2110: * Initiate forwarding of connections to port "port" on remote host through
2111: * the secure channel to host:port from local side.
2112: */
1.1 deraadt 2113:
1.49 markus 2114: void
1.73 markus 2115: channel_request_remote_forwarding(u_short listen_port,
2116: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2117: {
1.153 markus 2118: int type, success = 0;
1.73 markus 2119:
1.25 markus 2120: /* Record locally that connection to this host/port is permitted. */
2121: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2122: fatal("channel_request_remote_forwarding: too many forwards");
2123:
2124: /* Send the forward request to the remote side. */
1.44 markus 2125: if (compat20) {
2126: const char *address_to_bind = "0.0.0.0";
2127: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2128: packet_put_cstring("tcpip-forward");
1.172.2.1! jason 2129: packet_put_char(1); /* boolean: want reply */
1.44 markus 2130: packet_put_cstring(address_to_bind);
2131: packet_put_int(listen_port);
1.73 markus 2132: packet_send();
2133: packet_write_wait();
2134: /* Assume that server accepts the request */
2135: success = 1;
1.44 markus 2136: } else {
2137: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2138: packet_put_int(listen_port);
2139: packet_put_cstring(host_to_connect);
1.44 markus 2140: packet_put_int(port_to_connect);
2141: packet_send();
2142: packet_write_wait();
1.73 markus 2143:
2144: /* Wait for response from the remote side. */
1.153 markus 2145: type = packet_read();
1.73 markus 2146: switch (type) {
2147: case SSH_SMSG_SUCCESS:
2148: success = 1;
2149: break;
2150: case SSH_SMSG_FAILURE:
2151: log("Warning: Server denied remote port forwarding.");
2152: break;
2153: default:
2154: /* Unknown packet */
2155: packet_disconnect("Protocol error for port forward request:"
2156: "received packet type %d.", type);
2157: }
2158: }
2159: if (success) {
2160: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2161: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2162: permitted_opens[num_permitted_opens].listen_port = listen_port;
2163: num_permitted_opens++;
1.44 markus 2164: }
1.1 deraadt 2165: }
2166:
1.27 markus 2167: /*
2168: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2169: * listening for the port, and sends back a success reply (or disconnect
2170: * message if there was an error). This never returns if there was an error.
2171: */
1.1 deraadt 2172:
1.49 markus 2173: void
1.56 markus 2174: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2175: {
1.31 markus 2176: u_short port, host_port;
1.25 markus 2177: char *hostname;
1.1 deraadt 2178:
1.25 markus 2179: /* Get arguments from the packet. */
2180: port = packet_get_int();
2181: hostname = packet_get_string(NULL);
2182: host_port = packet_get_int();
2183:
1.27 markus 2184: /*
2185: * Check that an unprivileged user is not trying to forward a
2186: * privileged port.
2187: */
1.25 markus 2188: if (port < IPPORT_RESERVED && !is_root)
2189: packet_disconnect("Requested forwarding of port %d but user is not root.",
2190: port);
1.73 markus 2191: /* Initiate forwarding */
1.160 markus 2192: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2193:
2194: /* Free the argument string. */
2195: xfree(hostname);
1.1 deraadt 2196: }
2197:
1.99 markus 2198: /*
2199: * Permits opening to any host/port if permitted_opens[] is empty. This is
2200: * usually called by the server, because the user could connect to any port
2201: * anyway, and the server has no way to know but to trust the client anyway.
2202: */
2203: void
1.142 itojun 2204: channel_permit_all_opens(void)
1.99 markus 2205: {
2206: if (num_permitted_opens == 0)
2207: all_opens_permitted = 1;
2208: }
2209:
1.101 markus 2210: void
1.99 markus 2211: channel_add_permitted_opens(char *host, int port)
2212: {
2213: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2214: fatal("channel_request_remote_forwarding: too many forwards");
2215: debug("allow port forwarding to host %s port %d", host, port);
2216:
2217: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2218: permitted_opens[num_permitted_opens].port_to_connect = port;
2219: num_permitted_opens++;
2220:
2221: all_opens_permitted = 0;
2222: }
2223:
1.101 markus 2224: void
1.99 markus 2225: channel_clear_permitted_opens(void)
2226: {
2227: int i;
2228:
2229: for (i = 0; i < num_permitted_opens; i++)
2230: xfree(permitted_opens[i].host_to_connect);
2231: num_permitted_opens = 0;
2232:
2233: }
2234:
2235:
2236: /* return socket to remote host, port */
1.127 itojun 2237: static int
1.99 markus 2238: connect_to(const char *host, u_short port)
1.41 markus 2239: {
2240: struct addrinfo hints, *ai, *aitop;
2241: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2242: int gaierr;
2243: int sock = -1;
2244:
2245: memset(&hints, 0, sizeof(hints));
2246: hints.ai_family = IPv4or6;
2247: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2248: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2249: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2250: error("connect_to %.100s: unknown host (%s)", host,
2251: gai_strerror(gaierr));
1.41 markus 2252: return -1;
2253: }
2254: for (ai = aitop; ai; ai = ai->ai_next) {
2255: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2256: continue;
2257: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2258: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2259: error("connect_to: getnameinfo failed");
1.41 markus 2260: continue;
2261: }
2262: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2263: if (sock < 0) {
2264: error("socket: %.100s", strerror(errno));
2265: continue;
2266: }
1.80 markus 2267: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2268: fatal("connect_to: F_SETFL: %s", strerror(errno));
2269: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2270: errno != EINPROGRESS) {
1.99 markus 2271: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2272: strerror(errno));
2273: close(sock);
1.89 stevesk 2274: continue; /* fail -- try next */
1.41 markus 2275: }
2276: break; /* success */
2277:
2278: }
2279: freeaddrinfo(aitop);
2280: if (!ai) {
1.99 markus 2281: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2282: return -1;
2283: }
2284: /* success */
1.169 stevesk 2285: set_nodelay(sock);
1.41 markus 2286: return sock;
2287: }
1.99 markus 2288:
1.73 markus 2289: int
1.130 stevesk 2290: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2291: {
2292: int i;
1.99 markus 2293:
1.73 markus 2294: for (i = 0; i < num_permitted_opens; i++)
2295: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2296: return connect_to(
1.73 markus 2297: permitted_opens[i].host_to_connect,
2298: permitted_opens[i].port_to_connect);
1.74 markus 2299: error("WARNING: Server requests forwarding for unknown listen_port %d",
2300: listen_port);
1.73 markus 2301: return -1;
2302: }
2303:
1.99 markus 2304: /* Check if connecting to that port is permitted and connect. */
2305: int
2306: channel_connect_to(const char *host, u_short port)
2307: {
2308: int i, permit;
2309:
2310: permit = all_opens_permitted;
2311: if (!permit) {
2312: for (i = 0; i < num_permitted_opens; i++)
2313: if (permitted_opens[i].port_to_connect == port &&
2314: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2315: permit = 1;
2316:
2317: }
2318: if (!permit) {
2319: log("Received request to connect to host %.100s port %d, "
2320: "but the request was denied.", host, port);
2321: return -1;
2322: }
2323: return connect_to(host, port);
2324: }
2325:
1.121 markus 2326: /* -- X11 forwarding */
1.1 deraadt 2327:
1.27 markus 2328: /*
2329: * Creates an internet domain socket for listening for X11 connections.
1.141 stevesk 2330: * Returns a suitable display number for the DISPLAY variable, or -1 if
2331: * an error occurs.
1.27 markus 2332: */
1.141 stevesk 2333: int
1.163 stevesk 2334: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.149 markus 2335: int single_connection)
1.1 deraadt 2336: {
1.149 markus 2337: Channel *nc = NULL;
1.31 markus 2338: int display_number, sock;
2339: u_short port;
1.35 markus 2340: struct addrinfo hints, *ai, *aitop;
2341: char strport[NI_MAXSERV];
2342: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2343:
1.33 markus 2344: for (display_number = x11_display_offset;
1.148 deraadt 2345: display_number < MAX_DISPLAYS;
2346: display_number++) {
1.25 markus 2347: port = 6000 + display_number;
1.35 markus 2348: memset(&hints, 0, sizeof(hints));
2349: hints.ai_family = IPv4or6;
1.163 stevesk 2350: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2351: hints.ai_socktype = SOCK_STREAM;
2352: snprintf(strport, sizeof strport, "%d", port);
2353: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2354: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2355: return -1;
1.25 markus 2356: }
1.35 markus 2357: for (ai = aitop; ai; ai = ai->ai_next) {
2358: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2359: continue;
2360: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2361: if (sock < 0) {
2362: error("socket: %.100s", strerror(errno));
1.141 stevesk 2363: return -1;
1.35 markus 2364: }
2365: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2366: debug("bind port %d: %.100s", port, strerror(errno));
2367: close(sock);
2368: for (n = 0; n < num_socks; n++) {
2369: close(socks[n]);
2370: }
2371: num_socks = 0;
2372: break;
2373: }
2374: socks[num_socks++] = sock;
2375: if (num_socks == NUM_SOCKS)
2376: break;
1.25 markus 2377: }
1.83 stevesk 2378: freeaddrinfo(aitop);
1.35 markus 2379: if (num_socks > 0)
2380: break;
1.25 markus 2381: }
2382: if (display_number >= MAX_DISPLAYS) {
2383: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2384: return -1;
1.25 markus 2385: }
2386: /* Start listening for connections on the socket. */
1.35 markus 2387: for (n = 0; n < num_socks; n++) {
2388: sock = socks[n];
2389: if (listen(sock, 5) < 0) {
2390: error("listen: %.100s", strerror(errno));
2391: close(sock);
1.141 stevesk 2392: return -1;
1.35 markus 2393: }
1.25 markus 2394: }
1.35 markus 2395:
2396: /* Allocate a channel for each socket. */
2397: for (n = 0; n < num_socks; n++) {
2398: sock = socks[n];
1.149 markus 2399: nc = channel_new("x11 listener",
1.51 markus 2400: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2401: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2402: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2403: nc->single_connection = single_connection;
1.35 markus 2404: }
1.1 deraadt 2405:
1.141 stevesk 2406: /* Return the display number for the DISPLAY environment variable. */
2407: return display_number;
1.1 deraadt 2408: }
2409:
1.127 itojun 2410: static int
1.77 markus 2411: connect_local_xsocket(u_int dnr)
1.1 deraadt 2412: {
1.25 markus 2413: int sock;
2414: struct sockaddr_un addr;
2415:
1.147 stevesk 2416: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2417: if (sock < 0)
2418: error("socket: %.100s", strerror(errno));
2419: memset(&addr, 0, sizeof(addr));
2420: addr.sun_family = AF_UNIX;
2421: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2422: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2423: return sock;
2424: close(sock);
1.25 markus 2425: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2426: return -1;
1.1 deraadt 2427: }
2428:
1.51 markus 2429: int
2430: x11_connect_display(void)
1.1 deraadt 2431: {
1.162 stevesk 2432: int display_number, sock = 0;
1.25 markus 2433: const char *display;
1.51 markus 2434: char buf[1024], *cp;
1.35 markus 2435: struct addrinfo hints, *ai, *aitop;
2436: char strport[NI_MAXSERV];
2437: int gaierr;
1.25 markus 2438:
2439: /* Try to open a socket for the local X server. */
2440: display = getenv("DISPLAY");
2441: if (!display) {
2442: error("DISPLAY not set.");
1.51 markus 2443: return -1;
1.25 markus 2444: }
1.27 markus 2445: /*
2446: * Now we decode the value of the DISPLAY variable and make a
2447: * connection to the real X server.
2448: */
2449:
2450: /*
2451: * Check if it is a unix domain socket. Unix domain displays are in
2452: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2453: */
1.25 markus 2454: if (strncmp(display, "unix:", 5) == 0 ||
2455: display[0] == ':') {
2456: /* Connect to the unix domain socket. */
2457: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2458: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2459: display);
1.51 markus 2460: return -1;
1.25 markus 2461: }
2462: /* Create a socket. */
2463: sock = connect_local_xsocket(display_number);
2464: if (sock < 0)
1.51 markus 2465: return -1;
1.25 markus 2466:
2467: /* OK, we now have a connection to the display. */
1.51 markus 2468: return sock;
1.25 markus 2469: }
1.27 markus 2470: /*
2471: * Connect to an inet socket. The DISPLAY value is supposedly
2472: * hostname:d[.s], where hostname may also be numeric IP address.
2473: */
1.145 stevesk 2474: strlcpy(buf, display, sizeof(buf));
1.25 markus 2475: cp = strchr(buf, ':');
2476: if (!cp) {
2477: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2478: return -1;
1.25 markus 2479: }
2480: *cp = 0;
1.27 markus 2481: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2482: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2483: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2484: display);
1.51 markus 2485: return -1;
1.25 markus 2486: }
1.35 markus 2487:
2488: /* Look up the host address */
2489: memset(&hints, 0, sizeof(hints));
2490: hints.ai_family = IPv4or6;
2491: hints.ai_socktype = SOCK_STREAM;
2492: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2493: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2494: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2495: return -1;
1.25 markus 2496: }
1.35 markus 2497: for (ai = aitop; ai; ai = ai->ai_next) {
2498: /* Create a socket. */
2499: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2500: if (sock < 0) {
2501: debug("socket: %.100s", strerror(errno));
1.41 markus 2502: continue;
2503: }
2504: /* Connect it to the display. */
2505: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2506: debug("connect %.100s port %d: %.100s", buf,
2507: 6000 + display_number, strerror(errno));
2508: close(sock);
2509: continue;
2510: }
2511: /* Success */
2512: break;
1.35 markus 2513: }
2514: freeaddrinfo(aitop);
2515: if (!ai) {
1.49 markus 2516: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2517: strerror(errno));
1.51 markus 2518: return -1;
1.25 markus 2519: }
1.162 stevesk 2520: set_nodelay(sock);
1.51 markus 2521: return sock;
2522: }
2523:
2524: /*
2525: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2526: * the remote channel number. We should do whatever we want, and respond
2527: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2528: */
2529:
2530: void
1.154 markus 2531: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2532: {
1.113 markus 2533: Channel *c = NULL;
2534: int remote_id, sock = 0;
1.51 markus 2535: char *remote_host;
1.25 markus 2536:
1.113 markus 2537: debug("Received X11 open request.");
1.51 markus 2538:
1.113 markus 2539: remote_id = packet_get_int();
1.121 markus 2540:
2541: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2542: remote_host = packet_get_string(NULL);
1.51 markus 2543: } else {
2544: remote_host = xstrdup("unknown (remote did not supply name)");
2545: }
1.152 markus 2546: packet_check_eom();
1.25 markus 2547:
1.51 markus 2548: /* Obtain a connection to the real X display. */
2549: sock = x11_connect_display();
1.113 markus 2550: if (sock != -1) {
2551: /* Allocate a channel for this connection. */
2552: c = channel_new("connected x11 socket",
2553: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2554: remote_host, 1);
1.167 markus 2555: c->remote_id = remote_id;
2556: c->force_drain = 1;
1.113 markus 2557: }
2558: if (c == NULL) {
1.51 markus 2559: /* Send refusal to the remote host. */
2560: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2561: packet_put_int(remote_id);
1.51 markus 2562: } else {
2563: /* Send a confirmation to the remote host. */
2564: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2565: packet_put_int(remote_id);
2566: packet_put_int(c->self);
1.51 markus 2567: }
1.113 markus 2568: packet_send();
1.72 markus 2569: }
2570:
2571: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2572: void
1.154 markus 2573: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2574: {
2575: int rchan = packet_get_int();
1.143 deraadt 2576: switch (type) {
1.72 markus 2577: case SSH_SMSG_AGENT_OPEN:
2578: error("Warning: ssh server tried agent forwarding.");
2579: break;
2580: case SSH_SMSG_X11_OPEN:
2581: error("Warning: ssh server tried X11 forwarding.");
2582: break;
2583: default:
1.154 markus 2584: error("deny_input_open: type %d", type);
1.72 markus 2585: break;
2586: }
2587: error("Warning: this is probably a break in attempt by a malicious server.");
2588: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2589: packet_put_int(rchan);
2590: packet_send();
1.1 deraadt 2591: }
2592:
1.27 markus 2593: /*
2594: * Requests forwarding of X11 connections, generates fake authentication
2595: * data, and enables authentication spoofing.
1.121 markus 2596: * This should be called in the client only.
1.27 markus 2597: */
1.49 markus 2598: void
1.51 markus 2599: x11_request_forwarding_with_spoofing(int client_session_id,
2600: const char *proto, const char *data)
1.1 deraadt 2601: {
1.77 markus 2602: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2603: u_int i, value, len;
1.25 markus 2604: char *new_data;
2605: int screen_number;
2606: const char *cp;
2607: u_int32_t rand = 0;
2608:
2609: cp = getenv("DISPLAY");
2610: if (cp)
2611: cp = strchr(cp, ':');
2612: if (cp)
2613: cp = strchr(cp, '.');
2614: if (cp)
2615: screen_number = atoi(cp + 1);
2616: else
2617: screen_number = 0;
2618:
2619: /* Save protocol name. */
2620: x11_saved_proto = xstrdup(proto);
2621:
1.27 markus 2622: /*
2623: * Extract real authentication data and generate fake data of the
2624: * same length.
2625: */
1.25 markus 2626: x11_saved_data = xmalloc(data_len);
2627: x11_fake_data = xmalloc(data_len);
2628: for (i = 0; i < data_len; i++) {
2629: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2630: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2631: if (i % 4 == 0)
2632: rand = arc4random();
2633: x11_saved_data[i] = value;
2634: x11_fake_data[i] = rand & 0xff;
2635: rand >>= 8;
2636: }
2637: x11_saved_data_len = data_len;
2638: x11_fake_data_len = data_len;
2639:
2640: /* Convert the fake data into hex. */
1.90 markus 2641: len = 2 * data_len + 1;
2642: new_data = xmalloc(len);
1.25 markus 2643: for (i = 0; i < data_len; i++)
1.90 markus 2644: snprintf(new_data + 2 * i, len - 2 * i,
2645: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2646:
2647: /* Send the request packet. */
1.51 markus 2648: if (compat20) {
2649: channel_request_start(client_session_id, "x11-req", 0);
2650: packet_put_char(0); /* XXX bool single connection */
2651: } else {
2652: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2653: }
2654: packet_put_cstring(proto);
2655: packet_put_cstring(new_data);
1.25 markus 2656: packet_put_int(screen_number);
2657: packet_send();
2658: packet_write_wait();
2659: xfree(new_data);
1.1 deraadt 2660: }
2661:
1.121 markus 2662:
2663: /* -- agent forwarding */
2664:
1.1 deraadt 2665: /* Sends a message to the server to request authentication fd forwarding. */
2666:
1.49 markus 2667: void
1.142 itojun 2668: auth_request_forwarding(void)
1.1 deraadt 2669: {
1.25 markus 2670: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2671: packet_send();
2672: packet_write_wait();
1.1 deraadt 2673: }
2674:
1.27 markus 2675: /*
2676: * Returns the name of the forwarded authentication socket. Returns NULL if
2677: * there is no forwarded authentication socket. The returned value points to
2678: * a static buffer.
2679: */
1.1 deraadt 2680:
1.25 markus 2681: char *
1.142 itojun 2682: auth_get_socket_name(void)
1.1 deraadt 2683: {
1.121 markus 2684: return auth_sock_name;
1.1 deraadt 2685: }
2686:
1.12 markus 2687: /* removes the agent forwarding socket */
2688:
1.49 markus 2689: void
1.123 markus 2690: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2691: {
1.123 markus 2692: struct passwd *pw = _pw;
2693:
1.122 markus 2694: if (auth_sock_name) {
1.123 markus 2695: temporarily_use_uid(pw);
1.122 markus 2696: unlink(auth_sock_name);
2697: rmdir(auth_sock_dir);
2698: auth_sock_name = NULL;
1.123 markus 2699: restore_uid();
1.122 markus 2700: }
1.12 markus 2701: }
2702:
1.27 markus 2703: /*
1.59 markus 2704: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2705: * This starts forwarding authentication requests.
2706: */
1.1 deraadt 2707:
1.59 markus 2708: int
1.25 markus 2709: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2710: {
1.113 markus 2711: Channel *nc;
2712: int sock;
1.25 markus 2713: struct sockaddr_un sunaddr;
2714:
1.121 markus 2715: if (auth_get_socket_name() != NULL) {
2716: error("authentication forwarding requested twice.");
2717: return 0;
2718: }
1.25 markus 2719:
2720: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2721: temporarily_use_uid(pw);
1.25 markus 2722:
2723: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2724: auth_sock_name = xmalloc(MAXPATHLEN);
2725: auth_sock_dir = xmalloc(MAXPATHLEN);
2726: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2727:
2728: /* Create private directory for socket */
1.121 markus 2729: if (mkdtemp(auth_sock_dir) == NULL) {
2730: packet_send_debug("Agent forwarding disabled: "
2731: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2732: restore_uid();
1.121 markus 2733: xfree(auth_sock_name);
2734: xfree(auth_sock_dir);
2735: auth_sock_name = NULL;
2736: auth_sock_dir = NULL;
1.59 markus 2737: return 0;
2738: }
1.121 markus 2739: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2740: auth_sock_dir, (int) getpid());
1.25 markus 2741:
1.122 markus 2742: /* delete agent socket on fatal() */
1.123 markus 2743: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2744:
1.25 markus 2745: /* Create the socket. */
2746: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2747: if (sock < 0)
2748: packet_disconnect("socket: %.100s", strerror(errno));
2749:
2750: /* Bind it to the name. */
2751: memset(&sunaddr, 0, sizeof(sunaddr));
2752: sunaddr.sun_family = AF_UNIX;
1.145 stevesk 2753: strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
1.25 markus 2754:
2755: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2756: packet_disconnect("bind: %.100s", strerror(errno));
2757:
2758: /* Restore the privileged uid. */
2759: restore_uid();
2760:
2761: /* Start listening on the socket. */
2762: if (listen(sock, 5) < 0)
2763: packet_disconnect("listen: %.100s", strerror(errno));
2764:
2765: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2766: nc = channel_new("auth socket",
1.73 markus 2767: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2768: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2769: 0, xstrdup("auth socket"), 1);
1.121 markus 2770: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2771: return 1;
1.1 deraadt 2772: }
2773:
2774: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2775:
1.49 markus 2776: void
1.154 markus 2777: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2778: {
1.113 markus 2779: Channel *c = NULL;
2780: int remote_id, sock;
1.121 markus 2781: char *name;
1.41 markus 2782:
1.25 markus 2783: /* Read the remote channel number from the message. */
1.113 markus 2784: remote_id = packet_get_int();
1.152 markus 2785: packet_check_eom();
1.25 markus 2786:
1.27 markus 2787: /*
2788: * Get a connection to the local authentication agent (this may again
2789: * get forwarded).
2790: */
1.25 markus 2791: sock = ssh_get_authentication_socket();
2792:
1.27 markus 2793: /*
2794: * If we could not connect the agent, send an error message back to
2795: * the server. This should never happen unless the agent dies,
2796: * because authentication forwarding is only enabled if we have an
2797: * agent.
2798: */
1.113 markus 2799: if (sock >= 0) {
1.121 markus 2800: name = xstrdup("authentication agent connection");
2801: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2802: -1, 0, 0, 0, name, 1);
1.167 markus 2803: c->remote_id = remote_id;
2804: c->force_drain = 1;
1.113 markus 2805: }
2806: if (c == NULL) {
1.25 markus 2807: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2808: packet_put_int(remote_id);
2809: } else {
2810: /* Send a confirmation to the remote host. */
2811: debug("Forwarding authentication connection.");
2812: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2813: packet_put_int(remote_id);
2814: packet_put_int(c->self);
1.25 markus 2815: }
2816: packet_send();
1.1 deraadt 2817: }
![[BACK]](/icons/back.gif){kind=icon}
Return to channels.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh