Annotation of src/usr.bin/ssh/channels.c, Revision 1.135
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.128 markus 16: * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.135 ! markus 42: RCSID("$OpenBSD: channels.c,v 1.134 2001/09/17 21:04:01 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"
1.44 markus 57:
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.1 deraadt 71: static int channels_alloc = 0;
72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
112: /* Saved X11 authentication protocol name. */
113: static char *x11_saved_proto = NULL;
114:
115: /* Saved X11 authentication data. This is the real data. */
116: static char *x11_saved_data = NULL;
117: static u_int x11_saved_data_len = 0;
118:
119: /*
120: * Fake X11 authentication data. This is what the server will be sending us;
121: * we should replace any occurrences of this by the real data.
122: */
123: static char *x11_fake_data = NULL;
124: static u_int x11_fake_data_len;
125:
126:
127: /* -- agent forwarding */
128:
129: #define NUM_SOCKS 10
130:
131: /* Name and directory of socket for authentication agent forwarding. */
132: static char *auth_sock_name = NULL;
133: static char *auth_sock_dir = NULL;
134:
1.82 markus 135: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 ! markus 136: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 137:
1.121 markus 138: /* helper */
1.127 itojun 139: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 140:
1.121 markus 141: /* -- channel core */
1.41 markus 142:
143: Channel *
144: channel_lookup(int id)
145: {
146: Channel *c;
1.113 markus 147:
1.63 provos 148: if (id < 0 || id > channels_alloc) {
1.41 markus 149: log("channel_lookup: %d: bad id", id);
150: return NULL;
151: }
1.113 markus 152: c = channels[id];
153: if (c == NULL) {
1.41 markus 154: log("channel_lookup: %d: bad id: channel free", id);
155: return NULL;
156: }
157: return c;
1.55 markus 158: }
159:
1.27 markus 160: /*
1.55 markus 161: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 162: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 163: */
1.1 deraadt 164:
1.127 itojun 165: static void
1.71 markus 166: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
167: int extusage, int nonblock)
1.1 deraadt 168: {
1.25 markus 169: /* Update the maximum file descriptor value. */
1.84 markus 170: channel_max_fd = MAX(channel_max_fd, rfd);
171: channel_max_fd = MAX(channel_max_fd, wfd);
172: channel_max_fd = MAX(channel_max_fd, efd);
173:
1.27 markus 174: /* XXX set close-on-exec -markus */
1.55 markus 175:
1.52 markus 176: c->rfd = rfd;
177: c->wfd = wfd;
178: c->sock = (rfd == wfd) ? rfd : -1;
179: c->efd = efd;
180: c->extended_usage = extusage;
1.71 markus 181:
1.91 markus 182: /* XXX ugly hack: nonblock is only set by the server */
183: if (nonblock && isatty(c->rfd)) {
1.94 markus 184: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 185: c->isatty = 1;
186: if (!isatty(c->wfd)) {
1.94 markus 187: error("channel %d: wfd %d is not a tty?",
1.91 markus 188: c->self, c->wfd);
189: }
190: } else {
191: c->isatty = 0;
192: }
193:
1.71 markus 194: /* enable nonblocking mode */
195: if (nonblock) {
196: if (rfd != -1)
197: set_nonblock(rfd);
198: if (wfd != -1)
199: set_nonblock(wfd);
200: if (efd != -1)
201: set_nonblock(efd);
202: }
1.52 markus 203: }
204:
205: /*
206: * Allocate a new channel object and set its type and socket. This will cause
207: * remote_name to be freed.
208: */
209:
1.113 markus 210: Channel *
1.52 markus 211: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 212: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 213: {
214: int i, found;
215: Channel *c;
1.25 markus 216:
217: /* Do initial allocation if this is the first call. */
218: if (channels_alloc == 0) {
1.44 markus 219: chan_init();
1.25 markus 220: channels_alloc = 10;
1.113 markus 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.113 markus 223: channels[i] = NULL;
1.126 markus 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.113 markus 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.113 markus 240: channels[i] = NULL;
1.25 markus 241: }
1.113 markus 242: /* Initialize and return new channel. */
243: c = channels[found] = xmalloc(sizeof(Channel));
1.25 markus 244: buffer_init(&c->input);
245: buffer_init(&c->output);
1.41 markus 246: buffer_init(&c->extended);
1.25 markus 247: chan_init_iostates(c);
1.71 markus 248: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 249: c->self = found;
250: c->type = type;
1.41 markus 251: c->ctype = ctype;
1.51 markus 252: c->local_window = window;
253: c->local_window_max = window;
254: c->local_consumed = 0;
255: c->local_maxpacket = maxpack;
1.25 markus 256: c->remote_id = -1;
257: c->remote_name = remote_name;
1.41 markus 258: c->remote_window = 0;
259: c->remote_maxpacket = 0;
260: c->cb_fn = NULL;
261: c->cb_arg = NULL;
262: c->cb_event = 0;
1.133 markus 263: c->force_drain = 0;
1.131 markus 264: c->detach_user = NULL;
1.65 markus 265: c->input_filter = NULL;
1.25 markus 266: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 267: return c;
1.1 deraadt 268: }
1.52 markus 269:
1.132 markus 270: static int
271: channel_find_maxfd(void)
272: {
273: int i, max = 0;
274: Channel *c;
275:
276: for (i = 0; i < channels_alloc; i++) {
277: c = channels[i];
278: if (c != NULL) {
279: max = MAX(max, c->rfd);
280: max = MAX(max, c->wfd);
281: max = MAX(max, c->efd);
282: }
283: }
284: return max;
285: }
286:
287: int
288: channel_close_fd(int *fdp)
289: {
290: int ret = 0, fd = *fdp;
291:
292: if (fd != -1) {
293: ret = close(fd);
294: *fdp = -1;
295: if (fd == channel_max_fd)
296: channel_max_fd = channel_find_maxfd();
297: }
298: return ret;
299: }
300:
1.52 markus 301: /* Close all channel fd/socket. */
302:
1.127 itojun 303: static void
1.52 markus 304: channel_close_fds(Channel *c)
305: {
1.118 markus 306: debug3("channel_close_fds: channel %d: r %d w %d e %d",
307: c->self, c->rfd, c->wfd, c->efd);
308:
1.132 markus 309: channel_close_fd(&c->sock);
310: channel_close_fd(&c->rfd);
311: channel_close_fd(&c->wfd);
312: channel_close_fd(&c->efd);
1.121 markus 313: }
314:
315: /* Free the channel and close its fd/socket. */
316:
317: void
318: channel_free(Channel *c)
319: {
320: char *s;
321: int i, n;
322:
323: for (n = 0, i = 0; i < channels_alloc; i++)
324: if (channels[i])
325: n++;
326: debug("channel_free: channel %d: %s, nchannels %d", c->self,
327: c->remote_name ? c->remote_name : "???", n);
328:
329: s = channel_open_message();
330: debug3("channel_free: status: %s", s);
331: xfree(s);
332:
1.131 markus 333: if (c->detach_user != NULL) {
334: debug("channel_free: channel %d: detaching channel user", c->self);
335: c->detach_user(c->self, NULL);
1.121 markus 336: }
337: if (c->sock != -1)
338: shutdown(c->sock, SHUT_RDWR);
339: channel_close_fds(c);
340: buffer_free(&c->input);
341: buffer_free(&c->output);
342: buffer_free(&c->extended);
343: if (c->remote_name) {
344: xfree(c->remote_name);
345: c->remote_name = NULL;
346: }
347: channels[c->self] = NULL;
348: xfree(c);
349: }
350:
351: void
1.126 markus 352: channel_free_all(void)
1.121 markus 353: {
354: int i;
355:
1.126 markus 356: for (i = 0; i < channels_alloc; i++)
357: if (channels[i] != NULL)
358: channel_free(channels[i]);
1.121 markus 359: }
360:
1.131 markus 361: void
362: channel_detach_all(void)
363: {
364: int i;
365: Channel *c;
366:
367: for (i = 0; i < channels_alloc; i++) {
368: c = channels[i];
369: if (c != NULL && c->detach_user != NULL) {
370: debug("channel_detach_all: channel %d", c->self);
371: c->detach_user(c->self, NULL);
372: c->detach_user = NULL;
373: }
374: }
375: }
376:
1.121 markus 377: /*
378: * Closes the sockets/fds of all channels. This is used to close extra file
379: * descriptors after a fork.
380: */
381:
382: void
383: channel_close_all()
384: {
385: int i;
386:
387: for (i = 0; i < channels_alloc; i++)
388: if (channels[i] != NULL)
389: channel_close_fds(channels[i]);
390: }
391:
392: /*
1.131 markus 393: * Stop listening to channels.
394: */
395:
396: void
397: channel_stop_listening(void)
398: {
399: int i;
400: Channel *c;
401:
402: for (i = 0; i < channels_alloc; i++) {
403: c = channels[i];
404: if (c != NULL) {
405: switch (c->type) {
406: case SSH_CHANNEL_AUTH_SOCKET:
407: case SSH_CHANNEL_PORT_LISTENER:
408: case SSH_CHANNEL_RPORT_LISTENER:
409: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 410: channel_close_fd(&c->sock);
1.131 markus 411: channel_free(c);
412: break;
413: }
414: }
415: }
416: }
417:
418: /*
1.121 markus 419: * Returns true if no channel has too much buffered data, and false if one or
420: * more channel is overfull.
421: */
422:
423: int
424: channel_not_very_much_buffered_data()
425: {
426: u_int i;
427: Channel *c;
428:
429: for (i = 0; i < channels_alloc; i++) {
430: c = channels[i];
431: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
432: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
433: debug("channel %d: big input buffer %d",
434: c->self, buffer_len(&c->input));
435: return 0;
436: }
437: if (buffer_len(&c->output) > packet_get_maxsize()) {
438: debug("channel %d: big output buffer %d",
439: c->self, buffer_len(&c->output));
440: return 0;
441: }
442: }
443: }
444: return 1;
445: }
446:
447: /* Returns true if any channel is still open. */
448:
449: int
450: channel_still_open()
451: {
452: int i;
453: Channel *c;
454:
455: for (i = 0; i < channels_alloc; i++) {
456: c = channels[i];
457: if (c == NULL)
458: continue;
459: switch (c->type) {
460: case SSH_CHANNEL_X11_LISTENER:
461: case SSH_CHANNEL_PORT_LISTENER:
462: case SSH_CHANNEL_RPORT_LISTENER:
463: case SSH_CHANNEL_CLOSED:
464: case SSH_CHANNEL_AUTH_SOCKET:
465: case SSH_CHANNEL_DYNAMIC:
466: case SSH_CHANNEL_CONNECTING:
467: case SSH_CHANNEL_ZOMBIE:
468: continue;
469: case SSH_CHANNEL_LARVAL:
470: if (!compat20)
471: fatal("cannot happen: SSH_CHANNEL_LARVAL");
472: continue;
473: case SSH_CHANNEL_OPENING:
474: case SSH_CHANNEL_OPEN:
475: case SSH_CHANNEL_X11_OPEN:
476: return 1;
477: case SSH_CHANNEL_INPUT_DRAINING:
478: case SSH_CHANNEL_OUTPUT_DRAINING:
479: if (!compat13)
480: fatal("cannot happen: OUT_DRAIN");
481: return 1;
482: default:
483: fatal("channel_still_open: bad channel type %d", c->type);
484: /* NOTREACHED */
485: }
486: }
487: return 0;
488: }
489:
490: /* Returns the id of an open channel suitable for keepaliving */
491:
492: int
493: channel_find_open()
494: {
495: int i;
496: Channel *c;
497:
498: for (i = 0; i < channels_alloc; i++) {
499: c = channels[i];
500: if (c == NULL)
501: continue;
502: switch (c->type) {
503: case SSH_CHANNEL_CLOSED:
504: case SSH_CHANNEL_DYNAMIC:
505: case SSH_CHANNEL_X11_LISTENER:
506: case SSH_CHANNEL_PORT_LISTENER:
507: case SSH_CHANNEL_RPORT_LISTENER:
508: case SSH_CHANNEL_OPENING:
509: case SSH_CHANNEL_CONNECTING:
510: case SSH_CHANNEL_ZOMBIE:
511: continue;
512: case SSH_CHANNEL_LARVAL:
513: case SSH_CHANNEL_AUTH_SOCKET:
514: case SSH_CHANNEL_OPEN:
515: case SSH_CHANNEL_X11_OPEN:
516: return i;
517: case SSH_CHANNEL_INPUT_DRAINING:
518: case SSH_CHANNEL_OUTPUT_DRAINING:
519: if (!compat13)
520: fatal("cannot happen: OUT_DRAIN");
521: return i;
522: default:
523: fatal("channel_find_open: bad channel type %d", c->type);
524: /* NOTREACHED */
525: }
526: }
527: return -1;
528: }
529:
530:
531: /*
532: * Returns a message describing the currently open forwarded connections,
533: * suitable for sending to the client. The message contains crlf pairs for
534: * newlines.
535: */
536:
537: char *
538: channel_open_message()
539: {
540: Buffer buffer;
541: Channel *c;
542: char buf[1024], *cp;
543: int i;
544:
545: buffer_init(&buffer);
546: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
547: buffer_append(&buffer, buf, strlen(buf));
548: for (i = 0; i < channels_alloc; i++) {
549: c = channels[i];
550: if (c == NULL)
551: continue;
552: switch (c->type) {
553: case SSH_CHANNEL_X11_LISTENER:
554: case SSH_CHANNEL_PORT_LISTENER:
555: case SSH_CHANNEL_RPORT_LISTENER:
556: case SSH_CHANNEL_CLOSED:
557: case SSH_CHANNEL_AUTH_SOCKET:
558: case SSH_CHANNEL_ZOMBIE:
559: continue;
560: case SSH_CHANNEL_LARVAL:
561: case SSH_CHANNEL_OPENING:
562: case SSH_CHANNEL_CONNECTING:
563: case SSH_CHANNEL_DYNAMIC:
564: case SSH_CHANNEL_OPEN:
565: case SSH_CHANNEL_X11_OPEN:
566: case SSH_CHANNEL_INPUT_DRAINING:
567: case SSH_CHANNEL_OUTPUT_DRAINING:
568: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
569: c->self, c->remote_name,
570: c->type, c->remote_id,
571: c->istate, buffer_len(&c->input),
572: c->ostate, buffer_len(&c->output),
573: c->rfd, c->wfd);
574: buffer_append(&buffer, buf, strlen(buf));
575: continue;
576: default:
577: fatal("channel_open_message: bad channel type %d", c->type);
578: /* NOTREACHED */
579: }
580: }
581: buffer_append(&buffer, "\0", 1);
582: cp = xstrdup(buffer_ptr(&buffer));
583: buffer_free(&buffer);
584: return cp;
585: }
586:
587: void
588: channel_send_open(int id)
589: {
590: Channel *c = channel_lookup(id);
591: if (c == NULL) {
592: log("channel_send_open: %d: bad id", id);
593: return;
594: }
595: debug("send channel open %d", id);
596: packet_start(SSH2_MSG_CHANNEL_OPEN);
597: packet_put_cstring(c->ctype);
598: packet_put_int(c->self);
599: packet_put_int(c->local_window);
600: packet_put_int(c->local_maxpacket);
601: packet_send();
602: }
603:
604: void
605: channel_request(int id, char *service, int wantconfirm)
606: {
607: channel_request_start(id, service, wantconfirm);
608: packet_send();
609: debug("channel request %d: %s", id, service) ;
610: }
611: void
612: channel_request_start(int id, char *service, int wantconfirm)
613: {
614: Channel *c = channel_lookup(id);
615: if (c == NULL) {
616: log("channel_request: %d: bad id", id);
617: return;
618: }
619: packet_start(SSH2_MSG_CHANNEL_REQUEST);
620: packet_put_int(c->remote_id);
621: packet_put_cstring(service);
622: packet_put_char(wantconfirm);
623: }
624: void
625: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
626: {
627: Channel *c = channel_lookup(id);
628: if (c == NULL) {
629: log("channel_register_callback: %d: bad id", id);
630: return;
631: }
632: c->cb_event = mtype;
633: c->cb_fn = fn;
634: c->cb_arg = arg;
635: }
636: void
637: channel_register_cleanup(int id, channel_callback_fn *fn)
638: {
639: Channel *c = channel_lookup(id);
640: if (c == NULL) {
641: log("channel_register_cleanup: %d: bad id", id);
642: return;
643: }
1.131 markus 644: c->detach_user = fn;
1.121 markus 645: }
646: void
647: channel_cancel_cleanup(int id)
648: {
649: Channel *c = channel_lookup(id);
650: if (c == NULL) {
651: log("channel_cancel_cleanup: %d: bad id", id);
652: return;
1.52 markus 653: }
1.131 markus 654: c->detach_user = NULL;
1.121 markus 655: }
656: void
657: channel_register_filter(int id, channel_filter_fn *fn)
658: {
659: Channel *c = channel_lookup(id);
660: if (c == NULL) {
661: log("channel_register_filter: %d: bad id", id);
662: return;
1.52 markus 663: }
1.121 markus 664: c->input_filter = fn;
1.52 markus 665: }
666:
1.49 markus 667: void
1.121 markus 668: channel_set_fds(int id, int rfd, int wfd, int efd,
669: int extusage, int nonblock)
1.1 deraadt 670: {
1.121 markus 671: Channel *c = channel_lookup(id);
672: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
673: fatal("channel_activate for non-larval channel %d.", id);
674: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
675: c->type = SSH_CHANNEL_OPEN;
676: /* XXX window size? */
677: c->local_window = c->local_window_max = c->local_maxpacket * 2;
678: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
679: packet_put_int(c->remote_id);
680: packet_put_int(c->local_window);
681: packet_send();
1.1 deraadt 682: }
683:
1.27 markus 684: /*
1.41 markus 685: * 'channel_pre*' are called just before select() to add any bits relevant to
686: * channels in the select bitmasks.
687: */
688: /*
689: * 'channel_post*': perform any appropriate operations for channels which
690: * have events pending.
1.27 markus 691: */
1.41 markus 692: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
693: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
694: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
695:
1.127 itojun 696: static void
1.41 markus 697: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
698: {
699: FD_SET(c->sock, readset);
700: }
701:
1.127 itojun 702: static void
1.75 markus 703: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
704: {
705: debug3("channel %d: waiting for connection", c->self);
706: FD_SET(c->sock, writeset);
707: }
708:
1.127 itojun 709: static void
1.41 markus 710: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
711: {
712: if (buffer_len(&c->input) < packet_get_maxsize())
713: FD_SET(c->sock, readset);
714: if (buffer_len(&c->output) > 0)
715: FD_SET(c->sock, writeset);
716: }
1.1 deraadt 717:
1.127 itojun 718: static void
1.41 markus 719: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
720: {
721: /* test whether sockets are 'alive' for read/write */
722: if (c->istate == CHAN_INPUT_OPEN)
723: if (buffer_len(&c->input) < packet_get_maxsize())
724: FD_SET(c->sock, readset);
725: if (c->ostate == CHAN_OUTPUT_OPEN ||
726: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
727: if (buffer_len(&c->output) > 0) {
728: FD_SET(c->sock, writeset);
729: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
730: chan_obuf_empty(c);
731: }
732: }
733: }
734:
1.127 itojun 735: static void
1.44 markus 736: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
737: {
738: if (c->istate == CHAN_INPUT_OPEN &&
739: c->remote_window > 0 &&
740: buffer_len(&c->input) < c->remote_window)
741: FD_SET(c->rfd, readset);
742: if (c->ostate == CHAN_OUTPUT_OPEN ||
743: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
744: if (buffer_len(&c->output) > 0) {
745: FD_SET(c->wfd, writeset);
746: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
747: chan_obuf_empty(c);
748: }
749: }
750: /** XXX check close conditions, too */
751: if (c->efd != -1) {
752: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
753: buffer_len(&c->extended) > 0)
754: FD_SET(c->efd, writeset);
755: else if (c->extended_usage == CHAN_EXTENDED_READ &&
756: buffer_len(&c->extended) < c->remote_window)
757: FD_SET(c->efd, readset);
758: }
759: }
760:
1.127 itojun 761: static void
1.41 markus 762: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
763: {
764: if (buffer_len(&c->input) == 0) {
765: packet_start(SSH_MSG_CHANNEL_CLOSE);
766: packet_put_int(c->remote_id);
767: packet_send();
768: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 769: debug("channel %d: closing after input drain.", c->self);
1.41 markus 770: }
771: }
772:
1.127 itojun 773: static void
1.41 markus 774: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
775: {
776: if (buffer_len(&c->output) == 0)
1.113 markus 777: chan_mark_dead(c);
1.49 markus 778: else
1.41 markus 779: FD_SET(c->sock, writeset);
780: }
781:
782: /*
783: * This is a special state for X11 authentication spoofing. An opened X11
784: * connection (when authentication spoofing is being done) remains in this
785: * state until the first packet has been completely read. The authentication
786: * data in that packet is then substituted by the real data if it matches the
787: * fake data, and the channel is put into normal mode.
1.51 markus 788: * XXX All this happens at the client side.
1.121 markus 789: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 790: */
1.127 itojun 791: static int
1.121 markus 792: x11_open_helper(Buffer *b)
1.1 deraadt 793: {
1.77 markus 794: u_char *ucp;
795: u_int proto_len, data_len;
1.25 markus 796:
1.41 markus 797: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 798: if (buffer_len(b) < 12)
1.41 markus 799: return 0;
800:
801: /* Parse the lengths of variable-length fields. */
1.121 markus 802: ucp = (u_char *) buffer_ptr(b);
1.41 markus 803: if (ucp[0] == 0x42) { /* Byte order MSB first. */
804: proto_len = 256 * ucp[6] + ucp[7];
805: data_len = 256 * ucp[8] + ucp[9];
806: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
807: proto_len = ucp[6] + 256 * ucp[7];
808: data_len = ucp[8] + 256 * ucp[9];
809: } else {
810: debug("Initial X11 packet contains bad byte order byte: 0x%x",
811: ucp[0]);
812: return -1;
813: }
814:
815: /* Check if the whole packet is in buffer. */
1.121 markus 816: if (buffer_len(b) <
1.41 markus 817: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
818: return 0;
819:
820: /* Check if authentication protocol matches. */
821: if (proto_len != strlen(x11_saved_proto) ||
822: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
823: debug("X11 connection uses different authentication protocol.");
824: return -1;
825: }
826: /* Check if authentication data matches our fake data. */
827: if (data_len != x11_fake_data_len ||
828: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
829: x11_fake_data, x11_fake_data_len) != 0) {
830: debug("X11 auth data does not match fake data.");
831: return -1;
832: }
833: /* Check fake data length */
834: if (x11_fake_data_len != x11_saved_data_len) {
835: error("X11 fake_data_len %d != saved_data_len %d",
836: x11_fake_data_len, x11_saved_data_len);
837: return -1;
838: }
839: /*
840: * Received authentication protocol and data match
841: * our fake data. Substitute the fake data with real
842: * data.
843: */
844: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
845: x11_saved_data, x11_saved_data_len);
846: return 1;
847: }
848:
1.127 itojun 849: static void
1.41 markus 850: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
851: {
1.121 markus 852: int ret = x11_open_helper(&c->output);
1.41 markus 853: if (ret == 1) {
854: /* Start normal processing for the channel. */
855: c->type = SSH_CHANNEL_OPEN;
1.47 markus 856: channel_pre_open_13(c, readset, writeset);
1.41 markus 857: } else if (ret == -1) {
858: /*
859: * We have received an X11 connection that has bad
860: * authentication information.
861: */
1.98 millert 862: log("X11 connection rejected because of wrong authentication.");
1.41 markus 863: buffer_clear(&c->input);
864: buffer_clear(&c->output);
1.132 markus 865: channel_close_fd(&c->sock);
1.41 markus 866: c->sock = -1;
867: c->type = SSH_CHANNEL_CLOSED;
868: packet_start(SSH_MSG_CHANNEL_CLOSE);
869: packet_put_int(c->remote_id);
870: packet_send();
871: }
872: }
1.25 markus 873:
1.127 itojun 874: static void
1.51 markus 875: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 876: {
1.121 markus 877: int ret = x11_open_helper(&c->output);
1.133 markus 878:
879: /* c->force_drain = 1; */
880:
1.41 markus 881: if (ret == 1) {
882: c->type = SSH_CHANNEL_OPEN;
1.57 markus 883: if (compat20)
884: channel_pre_open_20(c, readset, writeset);
885: else
886: channel_pre_open_15(c, readset, writeset);
1.41 markus 887: } else if (ret == -1) {
888: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 889: chan_read_failed(c); /** force close? */
1.41 markus 890: chan_write_failed(c);
891: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
892: }
893: }
1.25 markus 894:
1.104 markus 895: /* try to decode a socks4 header */
1.127 itojun 896: static int
1.104 markus 897: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 898: {
899: u_char *p, *host;
1.109 markus 900: int len, have, i, found;
1.104 markus 901: char username[256];
1.103 markus 902: struct {
903: u_int8_t version;
904: u_int8_t command;
905: u_int16_t dest_port;
1.104 markus 906: struct in_addr dest_addr;
1.103 markus 907: } s4_req, s4_rsp;
908:
1.104 markus 909: debug2("channel %d: decode socks4", c->self);
1.109 markus 910:
911: have = buffer_len(&c->input);
912: len = sizeof(s4_req);
913: if (have < len)
914: return 0;
915: p = buffer_ptr(&c->input);
916: for (found = 0, i = len; i < have; i++) {
917: if (p[i] == '\0') {
918: found = 1;
919: break;
920: }
921: if (i > 1024) {
922: /* the peer is probably sending garbage */
923: debug("channel %d: decode socks4: too long",
924: c->self);
925: return -1;
926: }
927: }
928: if (!found)
929: return 0;
1.103 markus 930: buffer_get(&c->input, (char *)&s4_req.version, 1);
931: buffer_get(&c->input, (char *)&s4_req.command, 1);
932: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 933: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 934: have = buffer_len(&c->input);
1.103 markus 935: p = buffer_ptr(&c->input);
936: len = strlen(p);
1.106 markus 937: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 938: if (len > have)
1.104 markus 939: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 940: c->self, len, have);
941: strlcpy(username, p, sizeof(username));
942: buffer_consume(&c->input, len);
943: buffer_consume(&c->input, 1); /* trailing '\0' */
944:
1.104 markus 945: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 946: strlcpy(c->path, host, sizeof(c->path));
947: c->host_port = ntohs(s4_req.dest_port);
948:
1.106 markus 949: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
950: c->self, host, c->host_port, s4_req.command);
1.103 markus 951:
1.104 markus 952: if (s4_req.command != 1) {
953: debug("channel %d: cannot handle: socks4 cn %d",
954: c->self, s4_req.command);
955: return -1;
1.103 markus 956: }
1.104 markus 957: s4_rsp.version = 0; /* vn: 0 for reply */
958: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 959: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 960: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 961: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 962: return 1;
963: }
964:
965: /* dynamic port forwarding */
1.127 itojun 966: static void
1.104 markus 967: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
968: {
969: u_char *p;
970: int have, ret;
1.103 markus 971:
1.104 markus 972: have = buffer_len(&c->input);
973:
974: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 975: /* buffer_dump(&c->input); */
1.104 markus 976: /* check if the fixed size part of the packet is in buffer. */
977: if (have < 4) {
978: /* need more */
979: FD_SET(c->sock, readset);
980: return;
981: }
982: /* try to guess the protocol */
983: p = buffer_ptr(&c->input);
984: switch (p[0]) {
985: case 0x04:
986: ret = channel_decode_socks4(c, readset, writeset);
987: break;
988: default:
989: ret = -1;
990: break;
991: }
992: if (ret < 0) {
1.113 markus 993: chan_mark_dead(c);
1.104 markus 994: } else if (ret == 0) {
995: debug2("channel %d: pre_dynamic: need more", c->self);
996: /* need more */
997: FD_SET(c->sock, readset);
998: } else {
999: /* switch to the next state */
1000: c->type = SSH_CHANNEL_OPENING;
1001: port_open_helper(c, "direct-tcpip");
1002: }
1.103 markus 1003: }
1004:
1.41 markus 1005: /* This is our fake X11 server socket. */
1.127 itojun 1006: static void
1.41 markus 1007: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1008: {
1.113 markus 1009: Channel *nc;
1.41 markus 1010: struct sockaddr addr;
1.113 markus 1011: int newsock;
1.41 markus 1012: socklen_t addrlen;
1.85 markus 1013: char buf[16384], *remote_ipaddr;
1.51 markus 1014: int remote_port;
1.25 markus 1015:
1.41 markus 1016: if (FD_ISSET(c->sock, readset)) {
1017: debug("X11 connection requested.");
1018: addrlen = sizeof(addr);
1019: newsock = accept(c->sock, &addr, &addrlen);
1020: if (newsock < 0) {
1021: error("accept: %.100s", strerror(errno));
1022: return;
1023: }
1.85 markus 1024: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1025: remote_port = get_peer_port(newsock);
1.41 markus 1026: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1027: remote_ipaddr, remote_port);
1.51 markus 1028:
1.113 markus 1029: nc = channel_new("accepted x11 socket",
1.51 markus 1030: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1031: c->local_window_max, c->local_maxpacket,
1.71 markus 1032: 0, xstrdup(buf), 1);
1.113 markus 1033: if (nc == NULL) {
1034: close(newsock);
1035: xfree(remote_ipaddr);
1036: return;
1037: }
1.51 markus 1038: if (compat20) {
1039: packet_start(SSH2_MSG_CHANNEL_OPEN);
1040: packet_put_cstring("x11");
1.113 markus 1041: packet_put_int(nc->self);
1.51 markus 1042: packet_put_int(c->local_window_max);
1043: packet_put_int(c->local_maxpacket);
1.85 markus 1044: /* originator ipaddr and port */
1045: packet_put_cstring(remote_ipaddr);
1.57 markus 1046: if (datafellows & SSH_BUG_X11FWD) {
1047: debug("ssh2 x11 bug compat mode");
1048: } else {
1049: packet_put_int(remote_port);
1050: }
1.51 markus 1051: packet_send();
1052: } else {
1053: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1054: packet_put_int(nc->self);
1.121 markus 1055: if (packet_get_protocol_flags() &
1056: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1057: packet_put_cstring(buf);
1.51 markus 1058: packet_send();
1059: }
1.85 markus 1060: xfree(remote_ipaddr);
1.41 markus 1061: }
1062: }
1.25 markus 1063:
1.127 itojun 1064: static void
1.103 markus 1065: port_open_helper(Channel *c, char *rtype)
1066: {
1067: int direct;
1068: char buf[1024];
1069: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1070: u_short remote_port = get_peer_port(c->sock);
1071:
1072: direct = (strcmp(rtype, "direct-tcpip") == 0);
1073:
1074: snprintf(buf, sizeof buf,
1075: "%s: listening port %d for %.100s port %d, "
1076: "connect from %.200s port %d",
1077: rtype, c->listening_port, c->path, c->host_port,
1078: remote_ipaddr, remote_port);
1079:
1080: xfree(c->remote_name);
1081: c->remote_name = xstrdup(buf);
1082:
1083: if (compat20) {
1084: packet_start(SSH2_MSG_CHANNEL_OPEN);
1085: packet_put_cstring(rtype);
1086: packet_put_int(c->self);
1087: packet_put_int(c->local_window_max);
1088: packet_put_int(c->local_maxpacket);
1089: if (direct) {
1090: /* target host, port */
1091: packet_put_cstring(c->path);
1092: packet_put_int(c->host_port);
1093: } else {
1094: /* listen address, port */
1095: packet_put_cstring(c->path);
1096: packet_put_int(c->listening_port);
1097: }
1098: /* originator host and port */
1099: packet_put_cstring(remote_ipaddr);
1100: packet_put_int(remote_port);
1101: packet_send();
1102: } else {
1103: packet_start(SSH_MSG_PORT_OPEN);
1104: packet_put_int(c->self);
1105: packet_put_cstring(c->path);
1106: packet_put_int(c->host_port);
1.121 markus 1107: if (packet_get_protocol_flags() &
1108: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1109: packet_put_cstring(c->remote_name);
1110: packet_send();
1111: }
1112: xfree(remote_ipaddr);
1113: }
1114:
1.41 markus 1115: /*
1116: * This socket is listening for connections to a forwarded TCP/IP port.
1117: */
1.127 itojun 1118: static void
1.41 markus 1119: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1120: {
1.103 markus 1121: Channel *nc;
1.41 markus 1122: struct sockaddr addr;
1.113 markus 1123: int newsock, nextstate;
1.41 markus 1124: socklen_t addrlen;
1.103 markus 1125: char *rtype;
1.73 markus 1126:
1.41 markus 1127: if (FD_ISSET(c->sock, readset)) {
1128: debug("Connection to port %d forwarding "
1129: "to %.100s port %d requested.",
1130: c->listening_port, c->path, c->host_port);
1.103 markus 1131:
1132: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
1133: "forwarded-tcpip" : "direct-tcpip";
1.115 markus 1134: nextstate = (c->host_port == 0 &&
1135: c->type != SSH_CHANNEL_RPORT_LISTENER) ?
1136: SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
1.103 markus 1137:
1.41 markus 1138: addrlen = sizeof(addr);
1139: newsock = accept(c->sock, &addr, &addrlen);
1140: if (newsock < 0) {
1141: error("accept: %.100s", strerror(errno));
1142: return;
1143: }
1.113 markus 1144: nc = channel_new(rtype,
1.103 markus 1145: nextstate, newsock, newsock, -1,
1.41 markus 1146: c->local_window_max, c->local_maxpacket,
1.103 markus 1147: 0, xstrdup(rtype), 1);
1148: if (nc == NULL) {
1.113 markus 1149: error("channel_post_port_listener: no new channel:");
1150: close(newsock);
1.103 markus 1151: return;
1.41 markus 1152: }
1.103 markus 1153: nc->listening_port = c->listening_port;
1154: nc->host_port = c->host_port;
1155: strlcpy(nc->path, c->path, sizeof(nc->path));
1156:
1157: if (nextstate != SSH_CHANNEL_DYNAMIC)
1158: port_open_helper(nc, rtype);
1.41 markus 1159: }
1160: }
1.25 markus 1161:
1.41 markus 1162: /*
1163: * This is the authentication agent socket listening for connections from
1164: * clients.
1165: */
1.127 itojun 1166: static void
1.41 markus 1167: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1168: {
1.113 markus 1169: Channel *nc;
1.121 markus 1170: char *name;
1.113 markus 1171: int newsock;
1.41 markus 1172: struct sockaddr addr;
1173: socklen_t addrlen;
1.25 markus 1174:
1.41 markus 1175: if (FD_ISSET(c->sock, readset)) {
1176: addrlen = sizeof(addr);
1177: newsock = accept(c->sock, &addr, &addrlen);
1178: if (newsock < 0) {
1179: error("accept from auth socket: %.100s", strerror(errno));
1180: return;
1181: }
1.121 markus 1182: name = xstrdup("accepted auth socket");
1.113 markus 1183: nc = channel_new("accepted auth socket",
1.73 markus 1184: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1185: c->local_window_max, c->local_maxpacket,
1.121 markus 1186: 0, name, 1);
1.113 markus 1187: if (nc == NULL) {
1188: error("channel_post_auth_listener: channel_new failed");
1.121 markus 1189: xfree(name);
1.113 markus 1190: close(newsock);
1191: }
1.73 markus 1192: if (compat20) {
1193: packet_start(SSH2_MSG_CHANNEL_OPEN);
1194: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1195: packet_put_int(nc->self);
1.73 markus 1196: packet_put_int(c->local_window_max);
1197: packet_put_int(c->local_maxpacket);
1198: } else {
1199: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1200: packet_put_int(nc->self);
1.73 markus 1201: }
1.41 markus 1202: packet_send();
1203: }
1204: }
1.25 markus 1205:
1.127 itojun 1206: static void
1.75 markus 1207: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1208: {
1.114 markus 1209: int err = 0;
1.129 stevesk 1210: socklen_t sz = sizeof(err);
1.114 markus 1211:
1.75 markus 1212: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 1213: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
1214: &sz) < 0) {
1215: err = errno;
1216: error("getsockopt SO_ERROR failed");
1217: }
1218: if (err == 0) {
1219: debug("channel %d: connected", c->self);
1220: c->type = SSH_CHANNEL_OPEN;
1221: if (compat20) {
1222: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1223: packet_put_int(c->remote_id);
1224: packet_put_int(c->self);
1225: packet_put_int(c->local_window);
1226: packet_put_int(c->local_maxpacket);
1227: } else {
1228: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1229: packet_put_int(c->remote_id);
1230: packet_put_int(c->self);
1231: }
1.75 markus 1232: } else {
1.114 markus 1233: debug("channel %d: not connected: %s",
1234: c->self, strerror(err));
1235: if (compat20) {
1236: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1237: packet_put_int(c->remote_id);
1238: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1239: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1240: packet_put_cstring(strerror(err));
1241: packet_put_cstring("");
1242: }
1.75 markus 1243: } else {
1.114 markus 1244: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1245: packet_put_int(c->remote_id);
1.75 markus 1246: }
1.114 markus 1247: chan_mark_dead(c);
1.75 markus 1248: }
1.114 markus 1249: packet_send();
1.75 markus 1250: }
1251: }
1252:
1.127 itojun 1253: static int
1.41 markus 1254: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1255: {
1256: char buf[16*1024];
1257: int len;
1.25 markus 1258:
1.118 markus 1259: if (c->rfd != -1 &&
1.41 markus 1260: FD_ISSET(c->rfd, readset)) {
1261: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1262: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1263: return 1;
1.41 markus 1264: if (len <= 0) {
1.51 markus 1265: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1266: c->self, c->rfd, len);
1.104 markus 1267: if (c->type != SSH_CHANNEL_OPEN) {
1268: debug("channel %d: not open", c->self);
1.113 markus 1269: chan_mark_dead(c);
1.103 markus 1270: return -1;
1.104 markus 1271: } else if (compat13) {
1.41 markus 1272: buffer_consume(&c->output, buffer_len(&c->output));
1273: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1274: debug("channel %d: input draining.", c->self);
1.25 markus 1275: } else {
1.41 markus 1276: chan_read_failed(c);
1.25 markus 1277: }
1.41 markus 1278: return -1;
1279: }
1.65 markus 1280: if(c->input_filter != NULL) {
1.66 markus 1281: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1282: debug("channel %d: filter stops", c->self);
1.65 markus 1283: chan_read_failed(c);
1284: }
1285: } else {
1286: buffer_append(&c->input, buf, len);
1287: }
1.41 markus 1288: }
1289: return 1;
1290: }
1.127 itojun 1291: static int
1.41 markus 1292: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1293: {
1.95 markus 1294: struct termios tio;
1.134 markus 1295: u_char *data;
1296: u_int dlen;
1.41 markus 1297: int len;
1.25 markus 1298:
1.41 markus 1299: /* Send buffered output data to the socket. */
1.118 markus 1300: if (c->wfd != -1 &&
1.41 markus 1301: FD_ISSET(c->wfd, writeset) &&
1302: buffer_len(&c->output) > 0) {
1.134 markus 1303: data = buffer_ptr(&c->output);
1304: dlen = buffer_len(&c->output);
1305: len = write(c->wfd, data, dlen);
1.53 markus 1306: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1307: return 1;
1.41 markus 1308: if (len <= 0) {
1.104 markus 1309: if (c->type != SSH_CHANNEL_OPEN) {
1310: debug("channel %d: not open", c->self);
1.113 markus 1311: chan_mark_dead(c);
1.104 markus 1312: return -1;
1313: } else if (compat13) {
1.41 markus 1314: buffer_consume(&c->output, buffer_len(&c->output));
1.121 markus 1315: debug("channel %d: input draining.", c->self);
1.41 markus 1316: c->type = SSH_CHANNEL_INPUT_DRAINING;
1317: } else {
1318: chan_write_failed(c);
1319: }
1320: return -1;
1.91 markus 1321: }
1.134 markus 1322: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1323: if (tcgetattr(c->wfd, &tio) == 0 &&
1324: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1325: /*
1326: * Simulate echo to reduce the impact of
1.96 markus 1327: * traffic analysis. We need to match the
1.95 markus 1328: * size of a SSH2_MSG_CHANNEL_DATA message
1329: * (4 byte channel id + data)
1.91 markus 1330: */
1.95 markus 1331: packet_send_ignore(4 + len);
1.91 markus 1332: packet_send();
1333: }
1.25 markus 1334: }
1.41 markus 1335: buffer_consume(&c->output, len);
1.44 markus 1336: if (compat20 && len > 0) {
1337: c->local_consumed += len;
1338: }
1339: }
1340: return 1;
1341: }
1.127 itojun 1342: static int
1.44 markus 1343: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1344: {
1345: char buf[16*1024];
1346: int len;
1347:
1.45 markus 1348: /** XXX handle drain efd, too */
1.44 markus 1349: if (c->efd != -1) {
1350: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1351: FD_ISSET(c->efd, writeset) &&
1352: buffer_len(&c->extended) > 0) {
1353: len = write(c->efd, buffer_ptr(&c->extended),
1354: buffer_len(&c->extended));
1.70 markus 1355: debug2("channel %d: written %d to efd %d",
1.44 markus 1356: c->self, len, c->efd);
1.93 markus 1357: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1358: return 1;
1359: if (len <= 0) {
1360: debug2("channel %d: closing write-efd %d",
1361: c->self, c->efd);
1.132 markus 1362: channel_close_fd(&c->efd);
1.93 markus 1363: } else {
1.44 markus 1364: buffer_consume(&c->extended, len);
1365: c->local_consumed += len;
1366: }
1367: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1368: FD_ISSET(c->efd, readset)) {
1369: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1370: debug2("channel %d: read %d from efd %d",
1.44 markus 1371: c->self, len, c->efd);
1.93 markus 1372: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1373: return 1;
1374: if (len <= 0) {
1375: debug2("channel %d: closing read-efd %d",
1.45 markus 1376: c->self, c->efd);
1.132 markus 1377: channel_close_fd(&c->efd);
1.93 markus 1378: } else {
1.44 markus 1379: buffer_append(&c->extended, buf, len);
1.93 markus 1380: }
1.44 markus 1381: }
1382: }
1383: return 1;
1384: }
1.127 itojun 1385: static int
1.93 markus 1386: channel_check_window(Channel *c)
1.44 markus 1387: {
1.104 markus 1388: if (c->type == SSH_CHANNEL_OPEN &&
1389: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1390: c->local_window < c->local_window_max/2 &&
1391: c->local_consumed > 0) {
1392: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1393: packet_put_int(c->remote_id);
1394: packet_put_int(c->local_consumed);
1395: packet_send();
1.70 markus 1396: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1397: c->self, c->local_window,
1398: c->local_consumed);
1399: c->local_window += c->local_consumed;
1400: c->local_consumed = 0;
1.1 deraadt 1401: }
1.41 markus 1402: return 1;
1.1 deraadt 1403: }
1404:
1.127 itojun 1405: static void
1.41 markus 1406: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1407: {
1408: channel_handle_rfd(c, readset, writeset);
1409: channel_handle_wfd(c, readset, writeset);
1410: }
1.1 deraadt 1411:
1.127 itojun 1412: static void
1.44 markus 1413: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1414: {
1415: channel_handle_rfd(c, readset, writeset);
1416: channel_handle_wfd(c, readset, writeset);
1417: channel_handle_efd(c, readset, writeset);
1.93 markus 1418:
1419: channel_check_window(c);
1.44 markus 1420: }
1421:
1.127 itojun 1422: static void
1.41 markus 1423: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1424: {
1.41 markus 1425: int len;
1426: /* Send buffered output data to the socket. */
1427: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1428: len = write(c->sock, buffer_ptr(&c->output),
1429: buffer_len(&c->output));
1430: if (len <= 0)
1431: buffer_consume(&c->output, buffer_len(&c->output));
1432: else
1433: buffer_consume(&c->output, len);
1434: }
1435: }
1.25 markus 1436:
1.127 itojun 1437: static void
1.44 markus 1438: channel_handler_init_20(void)
1439: {
1440: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1441: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1442: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1443: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1444: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1445: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1446: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1447: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1448:
1449: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1450: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1451: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1452: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1453: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1454: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1455: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1456: }
1457:
1.127 itojun 1458: static void
1.41 markus 1459: channel_handler_init_13(void)
1460: {
1461: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1462: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1463: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1464: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1465: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1466: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1467: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1468: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1469: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1470:
1.41 markus 1471: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1472: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1473: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1474: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1475: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1476: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1477: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1478: }
1.25 markus 1479:
1.127 itojun 1480: static void
1.41 markus 1481: channel_handler_init_15(void)
1482: {
1483: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1484: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1485: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1486: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1487: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1488: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1489: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1490:
1.41 markus 1491: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1492: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1493: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1494: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1495: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1496: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1497: }
1.27 markus 1498:
1.127 itojun 1499: static void
1.41 markus 1500: channel_handler_init(void)
1501: {
1502: int i;
1503: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1504: channel_pre[i] = NULL;
1505: channel_post[i] = NULL;
1506: }
1.44 markus 1507: if (compat20)
1508: channel_handler_init_20();
1509: else if (compat13)
1.41 markus 1510: channel_handler_init_13();
1511: else
1512: channel_handler_init_15();
1513: }
1.25 markus 1514:
1.127 itojun 1515: static void
1.41 markus 1516: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1517: {
1518: static int did_init = 0;
1519: int i;
1520: Channel *c;
1.25 markus 1521:
1.41 markus 1522: if (!did_init) {
1523: channel_handler_init();
1524: did_init = 1;
1525: }
1526: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1527: c = channels[i];
1528: if (c == NULL)
1.41 markus 1529: continue;
1.118 markus 1530: if (ftab[c->type] != NULL)
1531: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1532: if (chan_is_dead(c)) {
1533: /*
1534: * we have to remove the fd's from the select mask
1535: * before the channels are free'd and the fd's are
1536: * closed
1537: */
1538: if (c->wfd != -1)
1539: FD_CLR(c->wfd, writeset);
1540: if (c->rfd != -1)
1541: FD_CLR(c->rfd, readset);
1542: if (c->efd != -1) {
1543: if (c->extended_usage == CHAN_EXTENDED_READ)
1544: FD_CLR(c->efd, readset);
1545: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1546: FD_CLR(c->efd, writeset);
1547: }
1.113 markus 1548: channel_free(c);
1.93 markus 1549: }
1.1 deraadt 1550: }
1551: }
1552:
1.121 markus 1553: /*
1554: * Allocate/update select bitmasks and add any bits relevant to channels in
1555: * select bitmasks.
1556: */
1.49 markus 1557: void
1.100 markus 1558: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1559: int *nallocp, int rekeying)
1.41 markus 1560: {
1.84 markus 1561: int n;
1562: u_int sz;
1563:
1564: n = MAX(*maxfdp, channel_max_fd);
1565:
1566: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1567: /* perhaps check sz < nalloc/2 and shrink? */
1568: if (*readsetp == NULL || sz > *nallocp) {
1569: *readsetp = xrealloc(*readsetp, sz);
1570: *writesetp = xrealloc(*writesetp, sz);
1571: *nallocp = sz;
1.84 markus 1572: }
1.132 markus 1573: *maxfdp = n;
1.84 markus 1574: memset(*readsetp, 0, sz);
1575: memset(*writesetp, 0, sz);
1576:
1.100 markus 1577: if (!rekeying)
1578: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1579: }
1580:
1.121 markus 1581: /*
1582: * After select, perform any appropriate operations for channels which have
1583: * events pending.
1584: */
1.49 markus 1585: void
1.41 markus 1586: channel_after_select(fd_set * readset, fd_set * writeset)
1587: {
1588: channel_handler(channel_post, readset, writeset);
1589: }
1590:
1.121 markus 1591:
1.84 markus 1592: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1593:
1.49 markus 1594: void
1.25 markus 1595: channel_output_poll()
1.1 deraadt 1596: {
1.25 markus 1597: int len, i;
1.41 markus 1598: Channel *c;
1.1 deraadt 1599:
1.25 markus 1600: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1601: c = channels[i];
1602: if (c == NULL)
1603: continue;
1.37 markus 1604:
1.121 markus 1605: /*
1606: * We are only interested in channels that can have buffered
1607: * incoming data.
1608: */
1.37 markus 1609: if (compat13) {
1.41 markus 1610: if (c->type != SSH_CHANNEL_OPEN &&
1611: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1612: continue;
1613: } else {
1.41 markus 1614: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1615: continue;
1616: }
1.46 markus 1617: if (compat20 &&
1618: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1619: /* XXX is this true? */
1.97 markus 1620: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1621: continue;
1622: }
1.25 markus 1623:
1624: /* Get the amount of buffered data for this channel. */
1.93 markus 1625: if ((c->istate == CHAN_INPUT_OPEN ||
1626: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1627: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1628: /*
1629: * Send some data for the other side over the secure
1630: * connection.
1631: */
1.44 markus 1632: if (compat20) {
1633: if (len > c->remote_window)
1634: len = c->remote_window;
1635: if (len > c->remote_maxpacket)
1636: len = c->remote_maxpacket;
1.25 markus 1637: } else {
1.44 markus 1638: if (packet_is_interactive()) {
1639: if (len > 1024)
1640: len = 512;
1641: } else {
1642: /* Keep the packets at reasonable size. */
1643: if (len > packet_get_maxsize()/2)
1644: len = packet_get_maxsize()/2;
1645: }
1.25 markus 1646: }
1.41 markus 1647: if (len > 0) {
1.44 markus 1648: packet_start(compat20 ?
1649: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1650: packet_put_int(c->remote_id);
1651: packet_put_string(buffer_ptr(&c->input), len);
1652: packet_send();
1653: buffer_consume(&c->input, len);
1654: c->remote_window -= len;
1655: }
1656: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1657: if (compat13)
1658: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1659: /*
1660: * input-buffer is empty and read-socket shutdown:
1661: * tell peer, that we will not send more data: send IEOF
1662: */
1.41 markus 1663: chan_ibuf_empty(c);
1.25 markus 1664: }
1.44 markus 1665: /* Send extended data, i.e. stderr */
1666: if (compat20 &&
1667: c->remote_window > 0 &&
1668: (len = buffer_len(&c->extended)) > 0 &&
1669: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1670: debug2("channel %d: rwin %d elen %d euse %d",
1671: c->self, c->remote_window, buffer_len(&c->extended),
1672: c->extended_usage);
1.44 markus 1673: if (len > c->remote_window)
1674: len = c->remote_window;
1675: if (len > c->remote_maxpacket)
1676: len = c->remote_maxpacket;
1677: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1678: packet_put_int(c->remote_id);
1679: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1680: packet_put_string(buffer_ptr(&c->extended), len);
1681: packet_send();
1682: buffer_consume(&c->extended, len);
1683: c->remote_window -= len;
1.93 markus 1684: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1685: }
1.25 markus 1686: }
1.1 deraadt 1687: }
1688:
1.121 markus 1689:
1690: /* -- protocol input */
1.1 deraadt 1691:
1.49 markus 1692: void
1.69 markus 1693: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1694: {
1.37 markus 1695: int id;
1.25 markus 1696: char *data;
1.77 markus 1697: u_int data_len;
1.41 markus 1698: Channel *c;
1.25 markus 1699:
1700: /* Get the channel number and verify it. */
1.37 markus 1701: id = packet_get_int();
1.41 markus 1702: c = channel_lookup(id);
1703: if (c == NULL)
1.37 markus 1704: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1705:
1706: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1707: if (c->type != SSH_CHANNEL_OPEN &&
1708: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1709: return;
1710:
1711: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1712: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1713: return;
1714:
1715: /* Get the data. */
1716: data = packet_get_string(&data_len);
1.48 markus 1717: packet_done();
1.41 markus 1718:
1.44 markus 1719: if (compat20){
1720: if (data_len > c->local_maxpacket) {
1721: log("channel %d: rcvd big packet %d, maxpack %d",
1722: c->self, data_len, c->local_maxpacket);
1723: }
1724: if (data_len > c->local_window) {
1725: log("channel %d: rcvd too much data %d, win %d",
1726: c->self, data_len, c->local_window);
1727: xfree(data);
1728: return;
1729: }
1730: c->local_window -= data_len;
1731: }else{
1732: packet_integrity_check(plen, 4 + 4 + data_len, type);
1733: }
1.41 markus 1734: buffer_append(&c->output, data, data_len);
1.25 markus 1735: xfree(data);
1.1 deraadt 1736: }
1.121 markus 1737:
1.49 markus 1738: void
1.69 markus 1739: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1740: {
1741: int id;
1742: int tcode;
1743: char *data;
1.77 markus 1744: u_int data_len;
1.44 markus 1745: Channel *c;
1746:
1747: /* Get the channel number and verify it. */
1748: id = packet_get_int();
1749: c = channel_lookup(id);
1750:
1751: if (c == NULL)
1752: packet_disconnect("Received extended_data for bad channel %d.", id);
1753: if (c->type != SSH_CHANNEL_OPEN) {
1754: log("channel %d: ext data for non open", id);
1755: return;
1756: }
1757: tcode = packet_get_int();
1758: if (c->efd == -1 ||
1759: c->extended_usage != CHAN_EXTENDED_WRITE ||
1760: tcode != SSH2_EXTENDED_DATA_STDERR) {
1761: log("channel %d: bad ext data", c->self);
1762: return;
1763: }
1764: data = packet_get_string(&data_len);
1.48 markus 1765: packet_done();
1.44 markus 1766: if (data_len > c->local_window) {
1767: log("channel %d: rcvd too much extended_data %d, win %d",
1768: c->self, data_len, c->local_window);
1769: xfree(data);
1770: return;
1771: }
1.70 markus 1772: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1773: c->local_window -= data_len;
1774: buffer_append(&c->extended, data, data_len);
1775: xfree(data);
1776: }
1777:
1.49 markus 1778: void
1.69 markus 1779: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1780: {
1781: int id;
1782: Channel *c;
1783:
1784: packet_integrity_check(plen, 4, type);
1785:
1786: id = packet_get_int();
1787: c = channel_lookup(id);
1788: if (c == NULL)
1789: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1790: chan_rcvd_ieof(c);
1.133 markus 1791:
1792: /* XXX force input close */
1793: if (c->force_drain) {
1794: debug("channel %d: FORCE input drain", c->self);
1795: c->istate = CHAN_INPUT_WAIT_DRAIN;
1796: }
1797:
1.41 markus 1798: }
1.1 deraadt 1799:
1.49 markus 1800: void
1.69 markus 1801: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1802: {
1.41 markus 1803: int id;
1804: Channel *c;
1.1 deraadt 1805:
1.41 markus 1806: packet_integrity_check(plen, 4, type);
1807:
1808: id = packet_get_int();
1809: c = channel_lookup(id);
1810: if (c == NULL)
1811: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1812:
1813: /*
1814: * Send a confirmation that we have closed the channel and no more
1815: * data is coming for it.
1816: */
1.25 markus 1817: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1818: packet_put_int(c->remote_id);
1.25 markus 1819: packet_send();
1820:
1.27 markus 1821: /*
1822: * If the channel is in closed state, we have sent a close request,
1823: * and the other side will eventually respond with a confirmation.
1824: * Thus, we cannot free the channel here, because then there would be
1825: * no-one to receive the confirmation. The channel gets freed when
1826: * the confirmation arrives.
1827: */
1.41 markus 1828: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1829: /*
1830: * Not a closed channel - mark it as draining, which will
1831: * cause it to be freed later.
1832: */
1.41 markus 1833: buffer_consume(&c->input, buffer_len(&c->input));
1834: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1835: }
1.1 deraadt 1836: }
1837:
1.41 markus 1838: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1839: void
1.69 markus 1840: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1841: {
1842: int id = packet_get_int();
1843: Channel *c = channel_lookup(id);
1844: packet_integrity_check(plen, 4, type);
1845: if (c == NULL)
1846: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1847: chan_rcvd_oclose(c);
1848: }
1.1 deraadt 1849:
1.49 markus 1850: void
1.69 markus 1851: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1852: {
1.41 markus 1853: int id = packet_get_int();
1854: Channel *c = channel_lookup(id);
1.1 deraadt 1855:
1.48 markus 1856: packet_done();
1.41 markus 1857: if (c == NULL)
1858: packet_disconnect("Received close confirmation for "
1859: "out-of-range channel %d.", id);
1860: if (c->type != SSH_CHANNEL_CLOSED)
1861: packet_disconnect("Received close confirmation for "
1862: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1863: channel_free(c);
1.1 deraadt 1864: }
1865:
1.49 markus 1866: void
1.69 markus 1867: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1868: {
1.41 markus 1869: int id, remote_id;
1870: Channel *c;
1.1 deraadt 1871:
1.44 markus 1872: if (!compat20)
1873: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1874:
1.41 markus 1875: id = packet_get_int();
1876: c = channel_lookup(id);
1.25 markus 1877:
1.41 markus 1878: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1879: packet_disconnect("Received open confirmation for "
1880: "non-opening channel %d.", id);
1881: remote_id = packet_get_int();
1.27 markus 1882: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1883: c->remote_id = remote_id;
1884: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1885:
1886: if (compat20) {
1887: c->remote_window = packet_get_int();
1888: c->remote_maxpacket = packet_get_int();
1.48 markus 1889: packet_done();
1.44 markus 1890: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1891: debug2("callback start");
1.44 markus 1892: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1893: debug2("callback done");
1.44 markus 1894: }
1895: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1896: c->remote_window, c->remote_maxpacket);
1897: }
1.1 deraadt 1898: }
1899:
1.127 itojun 1900: static char *
1.114 markus 1901: reason2txt(int reason)
1902: {
1903: switch(reason) {
1904: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1905: return "administratively prohibited";
1906: case SSH2_OPEN_CONNECT_FAILED:
1907: return "connect failed";
1908: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1909: return "unknown channel type";
1910: case SSH2_OPEN_RESOURCE_SHORTAGE:
1911: return "resource shortage";
1912: }
1.117 stevesk 1913: return "unknown reason";
1.114 markus 1914: }
1915:
1.49 markus 1916: void
1.69 markus 1917: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1918: {
1.86 markus 1919: int id, reason;
1920: char *msg = NULL, *lang = NULL;
1.41 markus 1921: Channel *c;
1922:
1.44 markus 1923: if (!compat20)
1924: packet_integrity_check(plen, 4, type);
1.41 markus 1925:
1926: id = packet_get_int();
1927: c = channel_lookup(id);
1.25 markus 1928:
1.41 markus 1929: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1930: packet_disconnect("Received open failure for "
1931: "non-opening channel %d.", id);
1.44 markus 1932: if (compat20) {
1.86 markus 1933: reason = packet_get_int();
1.110 markus 1934: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1935: msg = packet_get_string(NULL);
1936: lang = packet_get_string(NULL);
1937: }
1.48 markus 1938: packet_done();
1.114 markus 1939: log("channel %d: open failed: %s%s%s", id,
1940: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1941: if (msg != NULL)
1942: xfree(msg);
1943: if (lang != NULL)
1944: xfree(lang);
1.44 markus 1945: }
1.25 markus 1946: /* Free the channel. This will also close the socket. */
1.113 markus 1947: channel_free(c);
1.1 deraadt 1948: }
1949:
1.44 markus 1950: void
1.69 markus 1951: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1952: {
1953: int id;
1954: Channel *c;
1955:
1956: id = packet_get_int();
1957: c = channel_lookup(id);
1958:
1959: if (c == NULL ||
1960: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1961: packet_disconnect("Received request for "
1962: "non-open channel %d.", id);
1963: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1964: debug2("callback start");
1.44 markus 1965: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1966: debug2("callback done");
1.44 markus 1967: } else {
1968: char *service = packet_get_string(NULL);
1.94 markus 1969: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1970: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1971: xfree(service);
1972: }
1973: }
1974:
1.121 markus 1975: void
1976: channel_input_window_adjust(int type, int plen, void *ctxt)
1977: {
1978: Channel *c;
1979: int id, adjust;
1980:
1981: if (!compat20)
1982: return;
1983:
1984: /* Get the channel number and verify it. */
1985: id = packet_get_int();
1986: c = channel_lookup(id);
1.1 deraadt 1987:
1.121 markus 1988: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1989: log("Received window adjust for "
1990: "non-open channel %d.", id);
1991: return;
1992: }
1993: adjust = packet_get_int();
1994: packet_done();
1995: debug2("channel %d: rcvd adjust %d", id, adjust);
1996: c->remote_window += adjust;
1997: }
1.1 deraadt 1998:
1.121 markus 1999: void
2000: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2001: {
1.121 markus 2002: Channel *c = NULL;
2003: u_short host_port;
2004: char *host, *originator_string;
2005: int remote_id, sock = -1;
2006:
2007: remote_id = packet_get_int();
2008: host = packet_get_string(NULL);
2009: host_port = packet_get_int();
1.25 markus 2010:
1.121 markus 2011: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2012: originator_string = packet_get_string(NULL);
2013: } else {
2014: originator_string = xstrdup("unknown (remote did not supply name)");
2015: }
2016: packet_done();
2017: sock = channel_connect_to(host, host_port);
2018: if (sock != -1) {
2019: c = channel_new("connected socket",
2020: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2021: originator_string, 1);
2022: if (c == NULL) {
2023: error("channel_input_port_open: channel_new failed");
2024: close(sock);
2025: } else {
2026: c->remote_id = remote_id;
1.25 markus 2027: }
2028: }
1.121 markus 2029: if (c == NULL) {
2030: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2031: packet_put_int(remote_id);
2032: packet_send();
2033: }
2034: xfree(host);
1.1 deraadt 2035: }
2036:
1.121 markus 2037:
2038: /* -- tcp forwarding */
1.135 ! markus 2039:
! 2040: void
! 2041: channel_set_af(int af)
! 2042: {
! 2043: IPv4or6 = af;
! 2044: }
1.121 markus 2045:
1.27 markus 2046: /*
2047: * Initiate forwarding of connections to local port "port" through the secure
2048: * channel to host:port from remote side.
2049: */
1.87 markus 2050: int
1.73 markus 2051: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
2052: u_short port_to_connect, int gateway_ports)
2053: {
1.87 markus 2054: return channel_request_forwarding(
1.73 markus 2055: NULL, listen_port,
2056: host_to_connect, port_to_connect,
2057: gateway_ports, /*remote_fwd*/ 0);
2058: }
1.1 deraadt 2059:
1.73 markus 2060: /*
2061: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
2062: * (SSH_CHANNEL_RPORT_LISTENER).
2063: */
1.87 markus 2064: int
1.73 markus 2065: channel_request_forwarding(
2066: const char *listen_address, u_short listen_port,
2067: const char *host_to_connect, u_short port_to_connect,
2068: int gateway_ports, int remote_fwd)
1.25 markus 2069: {
1.113 markus 2070: Channel *c;
1.121 markus 2071: int success, sock, on = 1, type;
1.35 markus 2072: struct addrinfo hints, *ai, *aitop;
2073: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 2074: const char *host;
1.28 markus 2075: struct linger linger;
1.25 markus 2076:
1.87 markus 2077: success = 0;
2078:
1.73 markus 2079: if (remote_fwd) {
2080: host = listen_address;
1.121 markus 2081: type = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 2082: } else {
2083: host = host_to_connect;
1.121 markus 2084: type = SSH_CHANNEL_PORT_LISTENER;
1.73 markus 2085: }
2086:
1.113 markus 2087: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2088: error("Forward host name too long.");
2089: return success;
2090: }
1.25 markus 2091:
1.73 markus 2092: /* XXX listen_address is currently ignored */
1.28 markus 2093: /*
1.35 markus 2094: * getaddrinfo returns a loopback address if the hostname is
2095: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2096: */
1.35 markus 2097: memset(&hints, 0, sizeof(hints));
2098: hints.ai_family = IPv4or6;
2099: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2100: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2101: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2102: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2103: packet_disconnect("getaddrinfo: fatal error");
2104:
2105: for (ai = aitop; ai; ai = ai->ai_next) {
2106: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2107: continue;
2108: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2109: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 2110: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 2111: continue;
2112: }
2113: /* Create a port to listen for the host. */
2114: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2115: if (sock < 0) {
2116: /* this is no error since kernel may not support ipv6 */
2117: verbose("socket: %.100s", strerror(errno));
2118: continue;
2119: }
2120: /*
2121: * Set socket options. We would like the socket to disappear
2122: * as soon as it has been closed for whatever reason.
2123: */
2124: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2125: linger.l_onoff = 1;
2126: linger.l_linger = 5;
2127: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2128: debug("Local forwarding listening on %s port %s.", ntop, strport);
2129:
2130: /* Bind the socket to the address. */
2131: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2132: /* address can be in use ipv6 address is already bound */
2133: verbose("bind: %.100s", strerror(errno));
2134: close(sock);
2135: continue;
2136: }
2137: /* Start listening for connections on the socket. */
2138: if (listen(sock, 5) < 0) {
2139: error("listen: %.100s", strerror(errno));
2140: close(sock);
2141: continue;
2142: }
2143: /* Allocate a channel number for the socket. */
1.121 markus 2144: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2145: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2146: 0, xstrdup("port listener"), 1);
1.113 markus 2147: if (c == NULL) {
2148: error("channel_request_forwarding: channel_new failed");
2149: close(sock);
2150: continue;
2151: }
2152: strlcpy(c->path, host, sizeof(c->path));
2153: c->host_port = port_to_connect;
2154: c->listening_port = listen_port;
1.35 markus 2155: success = 1;
2156: }
2157: if (success == 0)
1.87 markus 2158: error("channel_request_forwarding: cannot listen to port: %d",
2159: listen_port);
1.35 markus 2160: freeaddrinfo(aitop);
1.87 markus 2161: return success;
1.25 markus 2162: }
1.1 deraadt 2163:
1.27 markus 2164: /*
2165: * Initiate forwarding of connections to port "port" on remote host through
2166: * the secure channel to host:port from local side.
2167: */
1.1 deraadt 2168:
1.49 markus 2169: void
1.73 markus 2170: channel_request_remote_forwarding(u_short listen_port,
2171: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2172: {
1.73 markus 2173: int payload_len, type, success = 0;
2174:
1.25 markus 2175: /* Record locally that connection to this host/port is permitted. */
2176: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2177: fatal("channel_request_remote_forwarding: too many forwards");
2178:
2179: /* Send the forward request to the remote side. */
1.44 markus 2180: if (compat20) {
2181: const char *address_to_bind = "0.0.0.0";
2182: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2183: packet_put_cstring("tcpip-forward");
2184: packet_put_char(0); /* boolean: want reply */
2185: packet_put_cstring(address_to_bind);
2186: packet_put_int(listen_port);
1.73 markus 2187: packet_send();
2188: packet_write_wait();
2189: /* Assume that server accepts the request */
2190: success = 1;
1.44 markus 2191: } else {
2192: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2193: packet_put_int(listen_port);
2194: packet_put_cstring(host_to_connect);
1.44 markus 2195: packet_put_int(port_to_connect);
2196: packet_send();
2197: packet_write_wait();
1.73 markus 2198:
2199: /* Wait for response from the remote side. */
2200: type = packet_read(&payload_len);
2201: switch (type) {
2202: case SSH_SMSG_SUCCESS:
2203: success = 1;
2204: break;
2205: case SSH_SMSG_FAILURE:
2206: log("Warning: Server denied remote port forwarding.");
2207: break;
2208: default:
2209: /* Unknown packet */
2210: packet_disconnect("Protocol error for port forward request:"
2211: "received packet type %d.", type);
2212: }
2213: }
2214: if (success) {
2215: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2216: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2217: permitted_opens[num_permitted_opens].listen_port = listen_port;
2218: num_permitted_opens++;
1.44 markus 2219: }
1.1 deraadt 2220: }
2221:
1.27 markus 2222: /*
2223: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2224: * listening for the port, and sends back a success reply (or disconnect
2225: * message if there was an error). This never returns if there was an error.
2226: */
1.1 deraadt 2227:
1.49 markus 2228: void
1.56 markus 2229: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2230: {
1.31 markus 2231: u_short port, host_port;
1.25 markus 2232: char *hostname;
1.1 deraadt 2233:
1.25 markus 2234: /* Get arguments from the packet. */
2235: port = packet_get_int();
2236: hostname = packet_get_string(NULL);
2237: host_port = packet_get_int();
2238:
1.27 markus 2239: /*
2240: * Check that an unprivileged user is not trying to forward a
2241: * privileged port.
2242: */
1.25 markus 2243: if (port < IPPORT_RESERVED && !is_root)
2244: packet_disconnect("Requested forwarding of port %d but user is not root.",
2245: port);
1.73 markus 2246: /* Initiate forwarding */
1.56 markus 2247: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2248:
2249: /* Free the argument string. */
2250: xfree(hostname);
1.1 deraadt 2251: }
2252:
1.99 markus 2253: /*
2254: * Permits opening to any host/port if permitted_opens[] is empty. This is
2255: * usually called by the server, because the user could connect to any port
2256: * anyway, and the server has no way to know but to trust the client anyway.
2257: */
2258: void
2259: channel_permit_all_opens()
2260: {
2261: if (num_permitted_opens == 0)
2262: all_opens_permitted = 1;
2263: }
2264:
1.101 markus 2265: void
1.99 markus 2266: channel_add_permitted_opens(char *host, int port)
2267: {
2268: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2269: fatal("channel_request_remote_forwarding: too many forwards");
2270: debug("allow port forwarding to host %s port %d", host, port);
2271:
2272: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2273: permitted_opens[num_permitted_opens].port_to_connect = port;
2274: num_permitted_opens++;
2275:
2276: all_opens_permitted = 0;
2277: }
2278:
1.101 markus 2279: void
1.99 markus 2280: channel_clear_permitted_opens(void)
2281: {
2282: int i;
2283:
2284: for (i = 0; i < num_permitted_opens; i++)
2285: xfree(permitted_opens[i].host_to_connect);
2286: num_permitted_opens = 0;
2287:
2288: }
2289:
2290:
2291: /* return socket to remote host, port */
1.127 itojun 2292: static int
1.99 markus 2293: connect_to(const char *host, u_short port)
1.41 markus 2294: {
2295: struct addrinfo hints, *ai, *aitop;
2296: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2297: int gaierr;
2298: int sock = -1;
2299:
2300: memset(&hints, 0, sizeof(hints));
2301: hints.ai_family = IPv4or6;
2302: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2303: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2304: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2305: error("connect_to %.100s: unknown host (%s)", host,
2306: gai_strerror(gaierr));
1.41 markus 2307: return -1;
2308: }
2309: for (ai = aitop; ai; ai = ai->ai_next) {
2310: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2311: continue;
2312: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2313: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2314: error("connect_to: getnameinfo failed");
1.41 markus 2315: continue;
2316: }
2317: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2318: if (sock < 0) {
2319: error("socket: %.100s", strerror(errno));
2320: continue;
2321: }
1.80 markus 2322: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2323: fatal("connect_to: F_SETFL: %s", strerror(errno));
2324: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2325: errno != EINPROGRESS) {
1.99 markus 2326: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2327: strerror(errno));
2328: close(sock);
1.89 stevesk 2329: continue; /* fail -- try next */
1.41 markus 2330: }
2331: break; /* success */
2332:
2333: }
2334: freeaddrinfo(aitop);
2335: if (!ai) {
1.99 markus 2336: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2337: return -1;
2338: }
2339: /* success */
2340: return sock;
2341: }
1.99 markus 2342:
1.73 markus 2343: int
1.130 stevesk 2344: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2345: {
2346: int i;
1.99 markus 2347:
1.73 markus 2348: for (i = 0; i < num_permitted_opens; i++)
2349: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2350: return connect_to(
1.73 markus 2351: permitted_opens[i].host_to_connect,
2352: permitted_opens[i].port_to_connect);
1.74 markus 2353: error("WARNING: Server requests forwarding for unknown listen_port %d",
2354: listen_port);
1.73 markus 2355: return -1;
2356: }
2357:
1.99 markus 2358: /* Check if connecting to that port is permitted and connect. */
2359: int
2360: channel_connect_to(const char *host, u_short port)
2361: {
2362: int i, permit;
2363:
2364: permit = all_opens_permitted;
2365: if (!permit) {
2366: for (i = 0; i < num_permitted_opens; i++)
2367: if (permitted_opens[i].port_to_connect == port &&
2368: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2369: permit = 1;
2370:
2371: }
2372: if (!permit) {
2373: log("Received request to connect to host %.100s port %d, "
2374: "but the request was denied.", host, port);
2375: return -1;
2376: }
2377: return connect_to(host, port);
2378: }
2379:
1.121 markus 2380: /* -- X11 forwarding */
1.1 deraadt 2381:
1.27 markus 2382: /*
2383: * Creates an internet domain socket for listening for X11 connections.
2384: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2385: * occurs.
2386: */
1.25 markus 2387: char *
1.33 markus 2388: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2389: {
1.31 markus 2390: int display_number, sock;
2391: u_short port;
1.35 markus 2392: struct addrinfo hints, *ai, *aitop;
2393: char strport[NI_MAXSERV];
2394: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2395: char display[512];
1.25 markus 2396: char hostname[MAXHOSTNAMELEN];
2397:
1.33 markus 2398: for (display_number = x11_display_offset;
1.25 markus 2399: display_number < MAX_DISPLAYS;
2400: display_number++) {
2401: port = 6000 + display_number;
1.35 markus 2402: memset(&hints, 0, sizeof(hints));
2403: hints.ai_family = IPv4or6;
1.36 markus 2404: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2405: hints.ai_socktype = SOCK_STREAM;
2406: snprintf(strport, sizeof strport, "%d", port);
2407: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2408: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2409: return NULL;
2410: }
1.35 markus 2411: for (ai = aitop; ai; ai = ai->ai_next) {
2412: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2413: continue;
2414: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2415: if (sock < 0) {
2416: error("socket: %.100s", strerror(errno));
2417: return NULL;
2418: }
2419: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2420: debug("bind port %d: %.100s", port, strerror(errno));
2421: shutdown(sock, SHUT_RDWR);
2422: close(sock);
2423: for (n = 0; n < num_socks; n++) {
2424: shutdown(socks[n], SHUT_RDWR);
2425: close(socks[n]);
2426: }
2427: num_socks = 0;
2428: break;
2429: }
2430: socks[num_socks++] = sock;
2431: if (num_socks == NUM_SOCKS)
2432: break;
1.25 markus 2433: }
1.83 stevesk 2434: freeaddrinfo(aitop);
1.35 markus 2435: if (num_socks > 0)
2436: break;
1.25 markus 2437: }
2438: if (display_number >= MAX_DISPLAYS) {
2439: error("Failed to allocate internet-domain X11 display socket.");
2440: return NULL;
2441: }
2442: /* Start listening for connections on the socket. */
1.35 markus 2443: for (n = 0; n < num_socks; n++) {
2444: sock = socks[n];
2445: if (listen(sock, 5) < 0) {
2446: error("listen: %.100s", strerror(errno));
2447: shutdown(sock, SHUT_RDWR);
2448: close(sock);
2449: return NULL;
2450: }
1.25 markus 2451: }
1.35 markus 2452:
1.25 markus 2453: /* Set up a suitable value for the DISPLAY variable. */
2454: if (gethostname(hostname, sizeof(hostname)) < 0)
2455: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2456: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2457: display_number, screen_number);
2458:
1.35 markus 2459: /* Allocate a channel for each socket. */
2460: for (n = 0; n < num_socks; n++) {
2461: sock = socks[n];
1.51 markus 2462: (void) channel_new("x11 listener",
2463: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2464: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2465: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2466: }
1.1 deraadt 2467:
1.25 markus 2468: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2469: return xstrdup(display);
1.1 deraadt 2470: }
2471:
2472: #ifndef X_UNIX_PATH
2473: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2474: #endif
2475:
1.127 itojun 2476: static int
1.77 markus 2477: connect_local_xsocket(u_int dnr)
1.1 deraadt 2478: {
1.25 markus 2479: static const char *const x_sockets[] = {
2480: X_UNIX_PATH "%u",
2481: "/var/X/.X11-unix/X" "%u",
2482: "/usr/spool/sockets/X11/" "%u",
2483: NULL
2484: };
2485: int sock;
2486: struct sockaddr_un addr;
2487: const char *const * path;
2488:
2489: for (path = x_sockets; *path; ++path) {
2490: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2491: if (sock < 0)
2492: error("socket: %.100s", strerror(errno));
2493: memset(&addr, 0, sizeof(addr));
2494: addr.sun_family = AF_UNIX;
2495: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2496: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2497: return sock;
2498: close(sock);
2499: }
2500: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2501: return -1;
1.1 deraadt 2502: }
2503:
1.51 markus 2504: int
2505: x11_connect_display(void)
1.1 deraadt 2506: {
1.51 markus 2507: int display_number, sock = 0;
1.25 markus 2508: const char *display;
1.51 markus 2509: char buf[1024], *cp;
1.35 markus 2510: struct addrinfo hints, *ai, *aitop;
2511: char strport[NI_MAXSERV];
2512: int gaierr;
1.25 markus 2513:
2514: /* Try to open a socket for the local X server. */
2515: display = getenv("DISPLAY");
2516: if (!display) {
2517: error("DISPLAY not set.");
1.51 markus 2518: return -1;
1.25 markus 2519: }
1.27 markus 2520: /*
2521: * Now we decode the value of the DISPLAY variable and make a
2522: * connection to the real X server.
2523: */
2524:
2525: /*
2526: * Check if it is a unix domain socket. Unix domain displays are in
2527: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2528: */
1.25 markus 2529: if (strncmp(display, "unix:", 5) == 0 ||
2530: display[0] == ':') {
2531: /* Connect to the unix domain socket. */
2532: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2533: error("Could not parse display number from DISPLAY: %.100s",
2534: display);
1.51 markus 2535: return -1;
1.25 markus 2536: }
2537: /* Create a socket. */
2538: sock = connect_local_xsocket(display_number);
2539: if (sock < 0)
1.51 markus 2540: return -1;
1.25 markus 2541:
2542: /* OK, we now have a connection to the display. */
1.51 markus 2543: return sock;
1.25 markus 2544: }
1.27 markus 2545: /*
2546: * Connect to an inet socket. The DISPLAY value is supposedly
2547: * hostname:d[.s], where hostname may also be numeric IP address.
2548: */
1.25 markus 2549: strncpy(buf, display, sizeof(buf));
2550: buf[sizeof(buf) - 1] = 0;
2551: cp = strchr(buf, ':');
2552: if (!cp) {
2553: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2554: return -1;
1.25 markus 2555: }
2556: *cp = 0;
1.27 markus 2557: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2558: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2559: error("Could not parse display number from DISPLAY: %.100s",
2560: display);
1.51 markus 2561: return -1;
1.25 markus 2562: }
1.35 markus 2563:
2564: /* Look up the host address */
2565: memset(&hints, 0, sizeof(hints));
2566: hints.ai_family = IPv4or6;
2567: hints.ai_socktype = SOCK_STREAM;
2568: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2569: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2570: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2571: return -1;
1.25 markus 2572: }
1.35 markus 2573: for (ai = aitop; ai; ai = ai->ai_next) {
2574: /* Create a socket. */
2575: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2576: if (sock < 0) {
2577: debug("socket: %.100s", strerror(errno));
1.41 markus 2578: continue;
2579: }
2580: /* Connect it to the display. */
2581: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2582: debug("connect %.100s port %d: %.100s", buf,
2583: 6000 + display_number, strerror(errno));
2584: close(sock);
2585: continue;
2586: }
2587: /* Success */
2588: break;
1.35 markus 2589: }
2590: freeaddrinfo(aitop);
2591: if (!ai) {
1.49 markus 2592: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2593: strerror(errno));
1.51 markus 2594: return -1;
1.25 markus 2595: }
1.51 markus 2596: return sock;
2597: }
2598:
2599: /*
2600: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2601: * the remote channel number. We should do whatever we want, and respond
2602: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2603: */
2604:
2605: void
1.69 markus 2606: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2607: {
1.113 markus 2608: Channel *c = NULL;
2609: int remote_id, sock = 0;
1.51 markus 2610: char *remote_host;
1.25 markus 2611:
1.113 markus 2612: debug("Received X11 open request.");
1.51 markus 2613:
1.113 markus 2614: remote_id = packet_get_int();
1.121 markus 2615:
2616: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2617: remote_host = packet_get_string(NULL);
1.51 markus 2618: } else {
2619: remote_host = xstrdup("unknown (remote did not supply name)");
2620: }
1.113 markus 2621: packet_done();
1.25 markus 2622:
1.51 markus 2623: /* Obtain a connection to the real X display. */
2624: sock = x11_connect_display();
1.113 markus 2625: if (sock != -1) {
2626: /* Allocate a channel for this connection. */
2627: c = channel_new("connected x11 socket",
2628: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2629: remote_host, 1);
2630: if (c == NULL) {
2631: error("x11_input_open: channel_new failed");
2632: close(sock);
2633: } else {
2634: c->remote_id = remote_id;
1.133 markus 2635: c->force_drain = 1;
1.113 markus 2636: }
2637: }
2638: if (c == NULL) {
1.51 markus 2639: /* Send refusal to the remote host. */
2640: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2641: packet_put_int(remote_id);
1.51 markus 2642: } else {
2643: /* Send a confirmation to the remote host. */
2644: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2645: packet_put_int(remote_id);
2646: packet_put_int(c->self);
1.51 markus 2647: }
1.113 markus 2648: packet_send();
1.72 markus 2649: }
2650:
2651: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2652: void
2653: deny_input_open(int type, int plen, void *ctxt)
2654: {
2655: int rchan = packet_get_int();
2656: switch(type){
2657: case SSH_SMSG_AGENT_OPEN:
2658: error("Warning: ssh server tried agent forwarding.");
2659: break;
2660: case SSH_SMSG_X11_OPEN:
2661: error("Warning: ssh server tried X11 forwarding.");
2662: break;
2663: default:
2664: error("deny_input_open: type %d plen %d", type, plen);
2665: break;
2666: }
2667: error("Warning: this is probably a break in attempt by a malicious server.");
2668: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2669: packet_put_int(rchan);
2670: packet_send();
1.1 deraadt 2671: }
2672:
1.27 markus 2673: /*
2674: * Requests forwarding of X11 connections, generates fake authentication
2675: * data, and enables authentication spoofing.
1.121 markus 2676: * This should be called in the client only.
1.27 markus 2677: */
1.49 markus 2678: void
1.51 markus 2679: x11_request_forwarding_with_spoofing(int client_session_id,
2680: const char *proto, const char *data)
1.1 deraadt 2681: {
1.77 markus 2682: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2683: u_int i, value, len;
1.25 markus 2684: char *new_data;
2685: int screen_number;
2686: const char *cp;
2687: u_int32_t rand = 0;
2688:
2689: cp = getenv("DISPLAY");
2690: if (cp)
2691: cp = strchr(cp, ':');
2692: if (cp)
2693: cp = strchr(cp, '.');
2694: if (cp)
2695: screen_number = atoi(cp + 1);
2696: else
2697: screen_number = 0;
2698:
2699: /* Save protocol name. */
2700: x11_saved_proto = xstrdup(proto);
2701:
1.27 markus 2702: /*
2703: * Extract real authentication data and generate fake data of the
2704: * same length.
2705: */
1.25 markus 2706: x11_saved_data = xmalloc(data_len);
2707: x11_fake_data = xmalloc(data_len);
2708: for (i = 0; i < data_len; i++) {
2709: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2710: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2711: if (i % 4 == 0)
2712: rand = arc4random();
2713: x11_saved_data[i] = value;
2714: x11_fake_data[i] = rand & 0xff;
2715: rand >>= 8;
2716: }
2717: x11_saved_data_len = data_len;
2718: x11_fake_data_len = data_len;
2719:
2720: /* Convert the fake data into hex. */
1.90 markus 2721: len = 2 * data_len + 1;
2722: new_data = xmalloc(len);
1.25 markus 2723: for (i = 0; i < data_len; i++)
1.90 markus 2724: snprintf(new_data + 2 * i, len - 2 * i,
2725: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2726:
2727: /* Send the request packet. */
1.51 markus 2728: if (compat20) {
2729: channel_request_start(client_session_id, "x11-req", 0);
2730: packet_put_char(0); /* XXX bool single connection */
2731: } else {
2732: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2733: }
2734: packet_put_cstring(proto);
2735: packet_put_cstring(new_data);
1.25 markus 2736: packet_put_int(screen_number);
2737: packet_send();
2738: packet_write_wait();
2739: xfree(new_data);
1.1 deraadt 2740: }
2741:
1.121 markus 2742:
2743: /* -- agent forwarding */
2744:
1.1 deraadt 2745: /* Sends a message to the server to request authentication fd forwarding. */
2746:
1.49 markus 2747: void
1.25 markus 2748: auth_request_forwarding()
1.1 deraadt 2749: {
1.25 markus 2750: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2751: packet_send();
2752: packet_write_wait();
1.1 deraadt 2753: }
2754:
1.27 markus 2755: /*
2756: * Returns the name of the forwarded authentication socket. Returns NULL if
2757: * there is no forwarded authentication socket. The returned value points to
2758: * a static buffer.
2759: */
1.1 deraadt 2760:
1.25 markus 2761: char *
2762: auth_get_socket_name()
1.1 deraadt 2763: {
1.121 markus 2764: return auth_sock_name;
1.1 deraadt 2765: }
2766:
1.12 markus 2767: /* removes the agent forwarding socket */
2768:
1.49 markus 2769: void
1.123 markus 2770: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2771: {
1.123 markus 2772: struct passwd *pw = _pw;
2773:
1.122 markus 2774: if (auth_sock_name) {
1.123 markus 2775: temporarily_use_uid(pw);
1.122 markus 2776: unlink(auth_sock_name);
2777: rmdir(auth_sock_dir);
2778: auth_sock_name = NULL;
1.123 markus 2779: restore_uid();
1.122 markus 2780: }
1.12 markus 2781: }
2782:
1.27 markus 2783: /*
1.59 markus 2784: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2785: * This starts forwarding authentication requests.
2786: */
1.1 deraadt 2787:
1.59 markus 2788: int
1.25 markus 2789: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2790: {
1.113 markus 2791: Channel *nc;
2792: int sock;
1.25 markus 2793: struct sockaddr_un sunaddr;
2794:
1.121 markus 2795: if (auth_get_socket_name() != NULL) {
2796: error("authentication forwarding requested twice.");
2797: return 0;
2798: }
1.25 markus 2799:
2800: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2801: temporarily_use_uid(pw);
1.25 markus 2802:
2803: /* Allocate a buffer for the socket name, and format the name. */
1.121 markus 2804: auth_sock_name = xmalloc(MAXPATHLEN);
2805: auth_sock_dir = xmalloc(MAXPATHLEN);
2806: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2807:
2808: /* Create private directory for socket */
1.121 markus 2809: if (mkdtemp(auth_sock_dir) == NULL) {
2810: packet_send_debug("Agent forwarding disabled: "
2811: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2812: restore_uid();
1.121 markus 2813: xfree(auth_sock_name);
2814: xfree(auth_sock_dir);
2815: auth_sock_name = NULL;
2816: auth_sock_dir = NULL;
1.59 markus 2817: return 0;
2818: }
1.121 markus 2819: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
2820: auth_sock_dir, (int) getpid());
1.25 markus 2821:
1.122 markus 2822: /* delete agent socket on fatal() */
1.123 markus 2823: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
1.122 markus 2824:
1.25 markus 2825: /* Create the socket. */
2826: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2827: if (sock < 0)
2828: packet_disconnect("socket: %.100s", strerror(errno));
2829:
2830: /* Bind it to the name. */
2831: memset(&sunaddr, 0, sizeof(sunaddr));
2832: sunaddr.sun_family = AF_UNIX;
1.121 markus 2833: strncpy(sunaddr.sun_path, auth_sock_name,
1.25 markus 2834: sizeof(sunaddr.sun_path));
2835:
2836: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2837: packet_disconnect("bind: %.100s", strerror(errno));
2838:
2839: /* Restore the privileged uid. */
2840: restore_uid();
2841:
2842: /* Start listening on the socket. */
2843: if (listen(sock, 5) < 0)
2844: packet_disconnect("listen: %.100s", strerror(errno));
2845:
2846: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2847: nc = channel_new("auth socket",
1.73 markus 2848: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2849: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2850: 0, xstrdup("auth socket"), 1);
1.113 markus 2851: if (nc == NULL) {
2852: error("auth_input_request_forwarding: channel_new failed");
1.123 markus 2853: auth_sock_cleanup_proc(pw);
1.124 markus 2854: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
1.113 markus 2855: close(sock);
2856: return 0;
2857: }
1.121 markus 2858: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2859: return 1;
1.1 deraadt 2860: }
2861:
2862: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2863:
1.49 markus 2864: void
1.69 markus 2865: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2866: {
1.113 markus 2867: Channel *c = NULL;
2868: int remote_id, sock;
1.121 markus 2869: char *name;
1.41 markus 2870:
2871: packet_integrity_check(plen, 4, type);
1.25 markus 2872:
2873: /* Read the remote channel number from the message. */
1.113 markus 2874: remote_id = packet_get_int();
1.25 markus 2875:
1.27 markus 2876: /*
2877: * Get a connection to the local authentication agent (this may again
2878: * get forwarded).
2879: */
1.25 markus 2880: sock = ssh_get_authentication_socket();
2881:
1.27 markus 2882: /*
2883: * If we could not connect the agent, send an error message back to
2884: * the server. This should never happen unless the agent dies,
2885: * because authentication forwarding is only enabled if we have an
2886: * agent.
2887: */
1.113 markus 2888: if (sock >= 0) {
1.121 markus 2889: name = xstrdup("authentication agent connection");
2890: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2891: -1, 0, 0, 0, name, 1);
1.113 markus 2892: if (c == NULL) {
2893: error("auth_input_open_request: channel_new failed");
1.121 markus 2894: xfree(name);
1.113 markus 2895: close(sock);
2896: } else {
2897: c->remote_id = remote_id;
1.133 markus 2898: c->force_drain = 1;
1.113 markus 2899: }
2900: }
2901: if (c == NULL) {
1.25 markus 2902: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2903: packet_put_int(remote_id);
2904: } else {
2905: /* Send a confirmation to the remote host. */
2906: debug("Forwarding authentication connection.");
2907: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2908: packet_put_int(remote_id);
2909: packet_put_int(c->self);
1.25 markus 2910: }
2911: packet_send();
1.1 deraadt 2912: }