Annotation of src/usr.bin/ssh/channels.c, Revision 1.186
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.156 markus 16: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.186 ! djm 42: RCSID("$OpenBSD: channels.c,v 1.185 2003/01/01 18:08:52 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.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:
1.82 markus 131: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 132: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 133:
1.121 markus 134: /* helper */
1.127 itojun 135: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 136:
1.121 markus 137: /* -- channel core */
1.41 markus 138:
139: Channel *
140: channel_lookup(int id)
141: {
142: Channel *c;
1.113 markus 143:
1.171 markus 144: if (id < 0 || id >= channels_alloc) {
1.41 markus 145: log("channel_lookup: %d: bad id", id);
146: return NULL;
147: }
1.113 markus 148: c = channels[id];
149: if (c == NULL) {
1.41 markus 150: log("channel_lookup: %d: bad id: channel free", id);
151: return NULL;
152: }
153: return c;
1.55 markus 154: }
155:
1.27 markus 156: /*
1.55 markus 157: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 158: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 159: */
1.1 deraadt 160:
1.127 itojun 161: static void
1.71 markus 162: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
163: int extusage, int nonblock)
1.1 deraadt 164: {
1.25 markus 165: /* Update the maximum file descriptor value. */
1.84 markus 166: channel_max_fd = MAX(channel_max_fd, rfd);
167: channel_max_fd = MAX(channel_max_fd, wfd);
168: channel_max_fd = MAX(channel_max_fd, efd);
169:
1.27 markus 170: /* XXX set close-on-exec -markus */
1.55 markus 171:
1.52 markus 172: c->rfd = rfd;
173: c->wfd = wfd;
174: c->sock = (rfd == wfd) ? rfd : -1;
175: c->efd = efd;
176: c->extended_usage = extusage;
1.71 markus 177:
1.91 markus 178: /* XXX ugly hack: nonblock is only set by the server */
179: if (nonblock && isatty(c->rfd)) {
1.94 markus 180: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 181: c->isatty = 1;
182: if (!isatty(c->wfd)) {
1.94 markus 183: error("channel %d: wfd %d is not a tty?",
1.91 markus 184: c->self, c->wfd);
185: }
186: } else {
187: c->isatty = 0;
188: }
189:
1.71 markus 190: /* enable nonblocking mode */
191: if (nonblock) {
192: if (rfd != -1)
193: set_nonblock(rfd);
194: if (wfd != -1)
195: set_nonblock(wfd);
196: if (efd != -1)
197: set_nonblock(efd);
198: }
1.52 markus 199: }
200:
201: /*
202: * Allocate a new channel object and set its type and socket. This will cause
203: * remote_name to be freed.
204: */
205:
1.113 markus 206: Channel *
1.52 markus 207: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 208: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 209: {
210: int i, found;
211: Channel *c;
1.25 markus 212:
213: /* Do initial allocation if this is the first call. */
214: if (channels_alloc == 0) {
215: channels_alloc = 10;
1.113 markus 216: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 217: for (i = 0; i < channels_alloc; i++)
1.113 markus 218: channels[i] = NULL;
1.126 markus 219: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 220: }
221: /* Try to find a free slot where to put the new channel. */
222: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 223: if (channels[i] == NULL) {
1.25 markus 224: /* Found a free slot. */
225: found = i;
226: break;
227: }
228: if (found == -1) {
1.27 markus 229: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 230: found = channels_alloc;
231: channels_alloc += 10;
1.179 markus 232: if (channels_alloc > 10000)
233: fatal("channel_new: internal error: channels_alloc %d "
234: "too big.", channels_alloc);
1.70 markus 235: debug2("channel: expanding %d", channels_alloc);
1.113 markus 236: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 237: for (i = found; i < channels_alloc; i++)
1.113 markus 238: channels[i] = NULL;
1.25 markus 239: }
1.113 markus 240: /* Initialize and return new channel. */
241: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 242: memset(c, 0, sizeof(Channel));
1.25 markus 243: buffer_init(&c->input);
244: buffer_init(&c->output);
1.41 markus 245: buffer_init(&c->extended);
1.159 markus 246: c->ostate = CHAN_OUTPUT_OPEN;
247: c->istate = CHAN_INPUT_OPEN;
248: c->flags = 0;
1.71 markus 249: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 250: c->self = found;
251: c->type = type;
1.41 markus 252: c->ctype = ctype;
1.51 markus 253: c->local_window = window;
254: c->local_window_max = window;
255: c->local_consumed = 0;
256: c->local_maxpacket = maxpack;
1.25 markus 257: c->remote_id = -1;
258: c->remote_name = remote_name;
1.41 markus 259: c->remote_window = 0;
260: c->remote_maxpacket = 0;
1.133 markus 261: c->force_drain = 0;
1.149 markus 262: c->single_connection = 0;
1.131 markus 263: c->detach_user = NULL;
1.165 markus 264: c->confirm = 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:
333: if (c->sock != -1)
334: shutdown(c->sock, SHUT_RDWR);
335: channel_close_fds(c);
336: buffer_free(&c->input);
337: buffer_free(&c->output);
338: buffer_free(&c->extended);
339: if (c->remote_name) {
340: xfree(c->remote_name);
341: c->remote_name = NULL;
342: }
343: channels[c->self] = NULL;
344: xfree(c);
345: }
346:
347: void
1.126 markus 348: channel_free_all(void)
1.121 markus 349: {
350: int i;
351:
1.126 markus 352: for (i = 0; i < channels_alloc; i++)
353: if (channels[i] != NULL)
354: channel_free(channels[i]);
1.131 markus 355: }
356:
1.121 markus 357: /*
358: * Closes the sockets/fds of all channels. This is used to close extra file
359: * descriptors after a fork.
360: */
361:
362: void
1.142 itojun 363: channel_close_all(void)
1.121 markus 364: {
365: int i;
366:
367: for (i = 0; i < channels_alloc; i++)
368: if (channels[i] != NULL)
369: channel_close_fds(channels[i]);
370: }
371:
372: /*
1.131 markus 373: * Stop listening to channels.
374: */
375:
376: void
377: channel_stop_listening(void)
378: {
379: int i;
380: Channel *c;
381:
382: for (i = 0; i < channels_alloc; i++) {
383: c = channels[i];
384: if (c != NULL) {
385: switch (c->type) {
386: case SSH_CHANNEL_AUTH_SOCKET:
387: case SSH_CHANNEL_PORT_LISTENER:
388: case SSH_CHANNEL_RPORT_LISTENER:
389: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 390: channel_close_fd(&c->sock);
1.131 markus 391: channel_free(c);
392: break;
393: }
394: }
395: }
396: }
397:
398: /*
1.121 markus 399: * Returns true if no channel has too much buffered data, and false if one or
400: * more channel is overfull.
401: */
402:
403: int
1.142 itojun 404: channel_not_very_much_buffered_data(void)
1.121 markus 405: {
406: u_int i;
407: Channel *c;
408:
409: for (i = 0; i < channels_alloc; i++) {
410: c = channels[i];
411: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 412: #if 0
413: if (!compat20 &&
414: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 415: debug2("channel %d: big input buffer %d",
1.121 markus 416: c->self, buffer_len(&c->input));
417: return 0;
418: }
1.136 markus 419: #endif
1.121 markus 420: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.185 markus 421: debug2("channel %d: big output buffer %d > %d",
1.136 markus 422: c->self, buffer_len(&c->output),
423: packet_get_maxsize());
1.121 markus 424: return 0;
425: }
426: }
427: }
428: return 1;
429: }
430:
431: /* Returns true if any channel is still open. */
432:
433: int
1.142 itojun 434: channel_still_open(void)
1.121 markus 435: {
436: int i;
437: Channel *c;
438:
439: for (i = 0; i < channels_alloc; i++) {
440: c = channels[i];
441: if (c == NULL)
442: continue;
443: switch (c->type) {
444: case SSH_CHANNEL_X11_LISTENER:
445: case SSH_CHANNEL_PORT_LISTENER:
446: case SSH_CHANNEL_RPORT_LISTENER:
447: case SSH_CHANNEL_CLOSED:
448: case SSH_CHANNEL_AUTH_SOCKET:
449: case SSH_CHANNEL_DYNAMIC:
450: case SSH_CHANNEL_CONNECTING:
451: case SSH_CHANNEL_ZOMBIE:
452: continue;
453: case SSH_CHANNEL_LARVAL:
454: if (!compat20)
455: fatal("cannot happen: SSH_CHANNEL_LARVAL");
456: continue;
457: case SSH_CHANNEL_OPENING:
458: case SSH_CHANNEL_OPEN:
459: case SSH_CHANNEL_X11_OPEN:
460: return 1;
461: case SSH_CHANNEL_INPUT_DRAINING:
462: case SSH_CHANNEL_OUTPUT_DRAINING:
463: if (!compat13)
464: fatal("cannot happen: OUT_DRAIN");
465: return 1;
466: default:
467: fatal("channel_still_open: bad channel type %d", c->type);
468: /* NOTREACHED */
469: }
470: }
471: return 0;
472: }
473:
474: /* Returns the id of an open channel suitable for keepaliving */
475:
476: int
1.142 itojun 477: channel_find_open(void)
1.121 markus 478: {
479: int i;
480: Channel *c;
481:
482: for (i = 0; i < channels_alloc; i++) {
483: c = channels[i];
484: if (c == NULL)
485: continue;
486: switch (c->type) {
487: case SSH_CHANNEL_CLOSED:
488: case SSH_CHANNEL_DYNAMIC:
489: case SSH_CHANNEL_X11_LISTENER:
490: case SSH_CHANNEL_PORT_LISTENER:
491: case SSH_CHANNEL_RPORT_LISTENER:
492: case SSH_CHANNEL_OPENING:
493: case SSH_CHANNEL_CONNECTING:
494: case SSH_CHANNEL_ZOMBIE:
495: continue;
496: case SSH_CHANNEL_LARVAL:
497: case SSH_CHANNEL_AUTH_SOCKET:
498: case SSH_CHANNEL_OPEN:
499: case SSH_CHANNEL_X11_OPEN:
500: return i;
501: case SSH_CHANNEL_INPUT_DRAINING:
502: case SSH_CHANNEL_OUTPUT_DRAINING:
503: if (!compat13)
504: fatal("cannot happen: OUT_DRAIN");
505: return i;
506: default:
507: fatal("channel_find_open: bad channel type %d", c->type);
508: /* NOTREACHED */
509: }
510: }
511: return -1;
512: }
513:
514:
515: /*
516: * Returns a message describing the currently open forwarded connections,
517: * suitable for sending to the client. The message contains crlf pairs for
518: * newlines.
519: */
520:
521: char *
1.142 itojun 522: channel_open_message(void)
1.121 markus 523: {
524: Buffer buffer;
525: Channel *c;
526: char buf[1024], *cp;
527: int i;
528:
529: buffer_init(&buffer);
530: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
531: buffer_append(&buffer, buf, strlen(buf));
532: for (i = 0; i < channels_alloc; i++) {
533: c = channels[i];
534: if (c == NULL)
535: continue;
536: switch (c->type) {
537: case SSH_CHANNEL_X11_LISTENER:
538: case SSH_CHANNEL_PORT_LISTENER:
539: case SSH_CHANNEL_RPORT_LISTENER:
540: case SSH_CHANNEL_CLOSED:
541: case SSH_CHANNEL_AUTH_SOCKET:
542: case SSH_CHANNEL_ZOMBIE:
543: continue;
544: case SSH_CHANNEL_LARVAL:
545: case SSH_CHANNEL_OPENING:
546: case SSH_CHANNEL_CONNECTING:
547: case SSH_CHANNEL_DYNAMIC:
548: case SSH_CHANNEL_OPEN:
549: case SSH_CHANNEL_X11_OPEN:
550: case SSH_CHANNEL_INPUT_DRAINING:
551: case SSH_CHANNEL_OUTPUT_DRAINING:
552: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
553: c->self, c->remote_name,
554: c->type, c->remote_id,
555: c->istate, buffer_len(&c->input),
556: c->ostate, buffer_len(&c->output),
557: c->rfd, c->wfd);
558: buffer_append(&buffer, buf, strlen(buf));
559: continue;
560: default:
561: fatal("channel_open_message: bad channel type %d", c->type);
562: /* NOTREACHED */
563: }
564: }
565: buffer_append(&buffer, "\0", 1);
566: cp = xstrdup(buffer_ptr(&buffer));
567: buffer_free(&buffer);
568: return cp;
569: }
570:
571: void
572: channel_send_open(int id)
573: {
574: Channel *c = channel_lookup(id);
1.180 deraadt 575:
1.121 markus 576: if (c == NULL) {
577: log("channel_send_open: %d: bad id", id);
578: return;
579: }
1.184 markus 580: debug2("channel %d: send open", id);
1.121 markus 581: packet_start(SSH2_MSG_CHANNEL_OPEN);
582: packet_put_cstring(c->ctype);
583: packet_put_int(c->self);
584: packet_put_int(c->local_window);
585: packet_put_int(c->local_maxpacket);
586: packet_send();
587: }
588:
589: void
1.184 markus 590: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 591: {
1.184 markus 592: Channel *c = channel_lookup(id);
1.180 deraadt 593:
1.121 markus 594: if (c == NULL) {
1.184 markus 595: log("channel_request_start: %d: unknown channel id", id);
1.121 markus 596: return;
597: }
1.184 markus 598: debug("channel %d: request %s", id, service) ;
1.121 markus 599: packet_start(SSH2_MSG_CHANNEL_REQUEST);
600: packet_put_int(c->remote_id);
601: packet_put_cstring(service);
602: packet_put_char(wantconfirm);
603: }
604: void
1.165 markus 605: channel_register_confirm(int id, channel_callback_fn *fn)
1.121 markus 606: {
607: Channel *c = channel_lookup(id);
1.180 deraadt 608:
1.121 markus 609: if (c == NULL) {
1.165 markus 610: log("channel_register_comfirm: %d: bad id", id);
1.121 markus 611: return;
612: }
1.165 markus 613: c->confirm = fn;
1.121 markus 614: }
615: void
616: channel_register_cleanup(int id, channel_callback_fn *fn)
617: {
618: Channel *c = channel_lookup(id);
1.180 deraadt 619:
1.121 markus 620: if (c == NULL) {
621: log("channel_register_cleanup: %d: bad id", id);
622: return;
623: }
1.131 markus 624: c->detach_user = fn;
1.121 markus 625: }
626: void
627: channel_cancel_cleanup(int id)
628: {
629: Channel *c = channel_lookup(id);
1.180 deraadt 630:
1.121 markus 631: if (c == NULL) {
632: log("channel_cancel_cleanup: %d: bad id", id);
633: return;
1.52 markus 634: }
1.131 markus 635: c->detach_user = NULL;
1.121 markus 636: }
637: void
638: channel_register_filter(int id, channel_filter_fn *fn)
639: {
640: Channel *c = channel_lookup(id);
1.180 deraadt 641:
1.121 markus 642: if (c == NULL) {
643: log("channel_register_filter: %d: bad id", id);
644: return;
1.52 markus 645: }
1.121 markus 646: c->input_filter = fn;
1.52 markus 647: }
648:
1.49 markus 649: void
1.121 markus 650: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 651: int extusage, int nonblock, u_int window_max)
1.1 deraadt 652: {
1.121 markus 653: Channel *c = channel_lookup(id);
1.180 deraadt 654:
1.121 markus 655: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
656: fatal("channel_activate for non-larval channel %d.", id);
657: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
658: c->type = SSH_CHANNEL_OPEN;
1.168 markus 659: c->local_window = c->local_window_max = window_max;
1.121 markus 660: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
661: packet_put_int(c->remote_id);
662: packet_put_int(c->local_window);
663: packet_send();
1.1 deraadt 664: }
665:
1.27 markus 666: /*
1.41 markus 667: * 'channel_pre*' are called just before select() to add any bits relevant to
668: * channels in the select bitmasks.
669: */
670: /*
671: * 'channel_post*': perform any appropriate operations for channels which
672: * have events pending.
1.27 markus 673: */
1.41 markus 674: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
675: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
676: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
677:
1.127 itojun 678: static void
1.41 markus 679: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
680: {
681: FD_SET(c->sock, readset);
682: }
683:
1.127 itojun 684: static void
1.75 markus 685: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
686: {
687: debug3("channel %d: waiting for connection", c->self);
688: FD_SET(c->sock, writeset);
689: }
690:
1.127 itojun 691: static void
1.41 markus 692: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
693: {
694: if (buffer_len(&c->input) < packet_get_maxsize())
695: FD_SET(c->sock, readset);
696: if (buffer_len(&c->output) > 0)
697: FD_SET(c->sock, writeset);
698: }
1.1 deraadt 699:
1.127 itojun 700: static void
1.157 markus 701: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 702: {
1.157 markus 703: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 704:
1.44 markus 705: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 706: limit > 0 &&
707: buffer_len(&c->input) < limit)
1.44 markus 708: FD_SET(c->rfd, readset);
709: if (c->ostate == CHAN_OUTPUT_OPEN ||
710: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
711: if (buffer_len(&c->output) > 0) {
712: FD_SET(c->wfd, writeset);
713: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 714: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.174 markus 715: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
716: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 717: else
718: chan_obuf_empty(c);
1.44 markus 719: }
720: }
721: /** XXX check close conditions, too */
1.157 markus 722: if (compat20 && c->efd != -1) {
1.44 markus 723: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
724: buffer_len(&c->extended) > 0)
725: FD_SET(c->efd, writeset);
1.172 markus 726: else if (!(c->flags & CHAN_EOF_SENT) &&
727: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 728: buffer_len(&c->extended) < c->remote_window)
729: FD_SET(c->efd, readset);
730: }
731: }
732:
1.127 itojun 733: static void
1.41 markus 734: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
735: {
736: if (buffer_len(&c->input) == 0) {
737: packet_start(SSH_MSG_CHANNEL_CLOSE);
738: packet_put_int(c->remote_id);
739: packet_send();
740: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 741: debug("channel %d: closing after input drain.", c->self);
1.41 markus 742: }
743: }
744:
1.127 itojun 745: static void
1.41 markus 746: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
747: {
748: if (buffer_len(&c->output) == 0)
1.113 markus 749: chan_mark_dead(c);
1.49 markus 750: else
1.41 markus 751: FD_SET(c->sock, writeset);
752: }
753:
754: /*
755: * This is a special state for X11 authentication spoofing. An opened X11
756: * connection (when authentication spoofing is being done) remains in this
757: * state until the first packet has been completely read. The authentication
758: * data in that packet is then substituted by the real data if it matches the
759: * fake data, and the channel is put into normal mode.
1.51 markus 760: * XXX All this happens at the client side.
1.121 markus 761: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 762: */
1.127 itojun 763: static int
1.121 markus 764: x11_open_helper(Buffer *b)
1.1 deraadt 765: {
1.77 markus 766: u_char *ucp;
767: u_int proto_len, data_len;
1.25 markus 768:
1.41 markus 769: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 770: if (buffer_len(b) < 12)
1.41 markus 771: return 0;
772:
773: /* Parse the lengths of variable-length fields. */
1.155 stevesk 774: ucp = buffer_ptr(b);
1.41 markus 775: if (ucp[0] == 0x42) { /* Byte order MSB first. */
776: proto_len = 256 * ucp[6] + ucp[7];
777: data_len = 256 * ucp[8] + ucp[9];
778: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
779: proto_len = ucp[6] + 256 * ucp[7];
780: data_len = ucp[8] + 256 * ucp[9];
781: } else {
782: debug("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 783: ucp[0]);
1.41 markus 784: return -1;
785: }
786:
787: /* Check if the whole packet is in buffer. */
1.121 markus 788: if (buffer_len(b) <
1.41 markus 789: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
790: return 0;
791:
792: /* Check if authentication protocol matches. */
793: if (proto_len != strlen(x11_saved_proto) ||
794: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
795: debug("X11 connection uses different authentication protocol.");
796: return -1;
797: }
798: /* Check if authentication data matches our fake data. */
799: if (data_len != x11_fake_data_len ||
800: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
801: x11_fake_data, x11_fake_data_len) != 0) {
802: debug("X11 auth data does not match fake data.");
803: return -1;
804: }
805: /* Check fake data length */
806: if (x11_fake_data_len != x11_saved_data_len) {
807: error("X11 fake_data_len %d != saved_data_len %d",
808: x11_fake_data_len, x11_saved_data_len);
809: return -1;
810: }
811: /*
812: * Received authentication protocol and data match
813: * our fake data. Substitute the fake data with real
814: * data.
815: */
816: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
817: x11_saved_data, x11_saved_data_len);
818: return 1;
819: }
820:
1.127 itojun 821: static void
1.41 markus 822: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
823: {
1.121 markus 824: int ret = x11_open_helper(&c->output);
1.180 deraadt 825:
1.41 markus 826: if (ret == 1) {
827: /* Start normal processing for the channel. */
828: c->type = SSH_CHANNEL_OPEN;
1.47 markus 829: channel_pre_open_13(c, readset, writeset);
1.41 markus 830: } else if (ret == -1) {
831: /*
832: * We have received an X11 connection that has bad
833: * authentication information.
834: */
1.98 millert 835: log("X11 connection rejected because of wrong authentication.");
1.41 markus 836: buffer_clear(&c->input);
837: buffer_clear(&c->output);
1.132 markus 838: channel_close_fd(&c->sock);
1.41 markus 839: c->sock = -1;
840: c->type = SSH_CHANNEL_CLOSED;
841: packet_start(SSH_MSG_CHANNEL_CLOSE);
842: packet_put_int(c->remote_id);
843: packet_send();
844: }
845: }
1.25 markus 846:
1.127 itojun 847: static void
1.51 markus 848: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 849: {
1.121 markus 850: int ret = x11_open_helper(&c->output);
1.133 markus 851:
852: /* c->force_drain = 1; */
853:
1.41 markus 854: if (ret == 1) {
855: c->type = SSH_CHANNEL_OPEN;
1.157 markus 856: channel_pre_open(c, readset, writeset);
1.41 markus 857: } else if (ret == -1) {
1.156 markus 858: log("X11 connection rejected because of wrong authentication.");
1.41 markus 859: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 860: chan_read_failed(c);
861: buffer_clear(&c->input);
862: chan_ibuf_empty(c);
863: buffer_clear(&c->output);
864: /* for proto v1, the peer will send an IEOF */
865: if (compat20)
866: chan_write_failed(c);
867: else
868: c->type = SSH_CHANNEL_OPEN;
1.41 markus 869: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
870: }
871: }
1.25 markus 872:
1.104 markus 873: /* try to decode a socks4 header */
1.127 itojun 874: static int
1.104 markus 875: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 876: {
1.181 markus 877: char *p, *host;
1.109 markus 878: int len, have, i, found;
1.148 deraadt 879: char username[256];
1.103 markus 880: struct {
881: u_int8_t version;
882: u_int8_t command;
883: u_int16_t dest_port;
1.104 markus 884: struct in_addr dest_addr;
1.103 markus 885: } s4_req, s4_rsp;
886:
1.104 markus 887: debug2("channel %d: decode socks4", c->self);
1.109 markus 888:
889: have = buffer_len(&c->input);
890: len = sizeof(s4_req);
891: if (have < len)
892: return 0;
893: p = buffer_ptr(&c->input);
894: for (found = 0, i = len; i < have; i++) {
895: if (p[i] == '\0') {
896: found = 1;
897: break;
898: }
899: if (i > 1024) {
900: /* the peer is probably sending garbage */
901: debug("channel %d: decode socks4: too long",
902: c->self);
903: return -1;
904: }
905: }
906: if (!found)
907: return 0;
1.103 markus 908: buffer_get(&c->input, (char *)&s4_req.version, 1);
909: buffer_get(&c->input, (char *)&s4_req.command, 1);
910: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 911: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 912: have = buffer_len(&c->input);
1.103 markus 913: p = buffer_ptr(&c->input);
914: len = strlen(p);
1.106 markus 915: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 916: if (len > have)
1.104 markus 917: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 918: c->self, len, have);
919: strlcpy(username, p, sizeof(username));
920: buffer_consume(&c->input, len);
921: buffer_consume(&c->input, 1); /* trailing '\0' */
922:
1.104 markus 923: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 924: strlcpy(c->path, host, sizeof(c->path));
925: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 926:
1.106 markus 927: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
928: c->self, host, c->host_port, s4_req.command);
1.103 markus 929:
1.104 markus 930: if (s4_req.command != 1) {
931: debug("channel %d: cannot handle: socks4 cn %d",
932: c->self, s4_req.command);
933: return -1;
1.103 markus 934: }
1.104 markus 935: s4_rsp.version = 0; /* vn: 0 for reply */
936: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 937: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 938: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 939: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 940: return 1;
941: }
942:
943: /* dynamic port forwarding */
1.127 itojun 944: static void
1.104 markus 945: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
946: {
947: u_char *p;
948: int have, ret;
1.103 markus 949:
1.104 markus 950: have = buffer_len(&c->input);
1.137 markus 951: c->delayed = 0;
1.104 markus 952: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 953: /* buffer_dump(&c->input); */
1.104 markus 954: /* check if the fixed size part of the packet is in buffer. */
955: if (have < 4) {
956: /* need more */
957: FD_SET(c->sock, readset);
958: return;
959: }
960: /* try to guess the protocol */
961: p = buffer_ptr(&c->input);
962: switch (p[0]) {
963: case 0x04:
964: ret = channel_decode_socks4(c, readset, writeset);
965: break;
966: default:
967: ret = -1;
968: break;
969: }
970: if (ret < 0) {
1.113 markus 971: chan_mark_dead(c);
1.104 markus 972: } else if (ret == 0) {
973: debug2("channel %d: pre_dynamic: need more", c->self);
974: /* need more */
975: FD_SET(c->sock, readset);
976: } else {
977: /* switch to the next state */
978: c->type = SSH_CHANNEL_OPENING;
979: port_open_helper(c, "direct-tcpip");
980: }
1.103 markus 981: }
982:
1.41 markus 983: /* This is our fake X11 server socket. */
1.127 itojun 984: static void
1.41 markus 985: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
986: {
1.113 markus 987: Channel *nc;
1.41 markus 988: struct sockaddr addr;
1.162 stevesk 989: int newsock;
1.41 markus 990: socklen_t addrlen;
1.85 markus 991: char buf[16384], *remote_ipaddr;
1.51 markus 992: int remote_port;
1.25 markus 993:
1.41 markus 994: if (FD_ISSET(c->sock, readset)) {
995: debug("X11 connection requested.");
996: addrlen = sizeof(addr);
997: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 998: if (c->single_connection) {
999: debug("single_connection: closing X11 listener.");
1000: channel_close_fd(&c->sock);
1001: chan_mark_dead(c);
1002: }
1.41 markus 1003: if (newsock < 0) {
1004: error("accept: %.100s", strerror(errno));
1005: return;
1006: }
1.162 stevesk 1007: set_nodelay(newsock);
1.85 markus 1008: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1009: remote_port = get_peer_port(newsock);
1.41 markus 1010: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1011: remote_ipaddr, remote_port);
1.51 markus 1012:
1.113 markus 1013: nc = channel_new("accepted x11 socket",
1.51 markus 1014: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1015: c->local_window_max, c->local_maxpacket,
1.71 markus 1016: 0, xstrdup(buf), 1);
1.51 markus 1017: if (compat20) {
1018: packet_start(SSH2_MSG_CHANNEL_OPEN);
1019: packet_put_cstring("x11");
1.113 markus 1020: packet_put_int(nc->self);
1.149 markus 1021: packet_put_int(nc->local_window_max);
1022: packet_put_int(nc->local_maxpacket);
1.85 markus 1023: /* originator ipaddr and port */
1024: packet_put_cstring(remote_ipaddr);
1.57 markus 1025: if (datafellows & SSH_BUG_X11FWD) {
1026: debug("ssh2 x11 bug compat mode");
1027: } else {
1028: packet_put_int(remote_port);
1029: }
1.51 markus 1030: packet_send();
1031: } else {
1032: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1033: packet_put_int(nc->self);
1.121 markus 1034: if (packet_get_protocol_flags() &
1035: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1036: packet_put_cstring(buf);
1.51 markus 1037: packet_send();
1038: }
1.85 markus 1039: xfree(remote_ipaddr);
1.41 markus 1040: }
1041: }
1.25 markus 1042:
1.127 itojun 1043: static void
1.103 markus 1044: port_open_helper(Channel *c, char *rtype)
1045: {
1046: int direct;
1047: char buf[1024];
1048: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1049: u_short remote_port = get_peer_port(c->sock);
1050:
1051: direct = (strcmp(rtype, "direct-tcpip") == 0);
1052:
1053: snprintf(buf, sizeof buf,
1054: "%s: listening port %d for %.100s port %d, "
1055: "connect from %.200s port %d",
1056: rtype, c->listening_port, c->path, c->host_port,
1057: remote_ipaddr, remote_port);
1058:
1059: xfree(c->remote_name);
1060: c->remote_name = xstrdup(buf);
1061:
1062: if (compat20) {
1063: packet_start(SSH2_MSG_CHANNEL_OPEN);
1064: packet_put_cstring(rtype);
1065: packet_put_int(c->self);
1066: packet_put_int(c->local_window_max);
1067: packet_put_int(c->local_maxpacket);
1068: if (direct) {
1069: /* target host, port */
1070: packet_put_cstring(c->path);
1071: packet_put_int(c->host_port);
1072: } else {
1073: /* listen address, port */
1074: packet_put_cstring(c->path);
1075: packet_put_int(c->listening_port);
1076: }
1077: /* originator host and port */
1078: packet_put_cstring(remote_ipaddr);
1079: packet_put_int(remote_port);
1080: packet_send();
1081: } else {
1082: packet_start(SSH_MSG_PORT_OPEN);
1083: packet_put_int(c->self);
1084: packet_put_cstring(c->path);
1085: packet_put_int(c->host_port);
1.121 markus 1086: if (packet_get_protocol_flags() &
1087: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1088: packet_put_cstring(c->remote_name);
1089: packet_send();
1090: }
1091: xfree(remote_ipaddr);
1092: }
1093:
1.41 markus 1094: /*
1095: * This socket is listening for connections to a forwarded TCP/IP port.
1096: */
1.127 itojun 1097: static void
1.41 markus 1098: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1099: {
1.103 markus 1100: Channel *nc;
1.41 markus 1101: struct sockaddr addr;
1.113 markus 1102: int newsock, nextstate;
1.41 markus 1103: socklen_t addrlen;
1.103 markus 1104: char *rtype;
1.73 markus 1105:
1.41 markus 1106: if (FD_ISSET(c->sock, readset)) {
1107: debug("Connection to port %d forwarding "
1108: "to %.100s port %d requested.",
1109: c->listening_port, c->path, c->host_port);
1.103 markus 1110:
1.137 markus 1111: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1112: nextstate = SSH_CHANNEL_OPENING;
1113: rtype = "forwarded-tcpip";
1114: } else {
1115: if (c->host_port == 0) {
1116: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1117: rtype = "dynamic-tcpip";
1.137 markus 1118: } else {
1119: nextstate = SSH_CHANNEL_OPENING;
1120: rtype = "direct-tcpip";
1121: }
1122: }
1.103 markus 1123:
1.41 markus 1124: addrlen = sizeof(addr);
1125: newsock = accept(c->sock, &addr, &addrlen);
1126: if (newsock < 0) {
1127: error("accept: %.100s", strerror(errno));
1128: return;
1129: }
1.169 stevesk 1130: set_nodelay(newsock);
1.113 markus 1131: nc = channel_new(rtype,
1.103 markus 1132: nextstate, newsock, newsock, -1,
1.41 markus 1133: c->local_window_max, c->local_maxpacket,
1.103 markus 1134: 0, xstrdup(rtype), 1);
1135: nc->listening_port = c->listening_port;
1136: nc->host_port = c->host_port;
1137: strlcpy(nc->path, c->path, sizeof(nc->path));
1138:
1.137 markus 1139: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1140: /*
1141: * do not call the channel_post handler until
1142: * this flag has been reset by a pre-handler.
1143: * otherwise the FD_ISSET calls might overflow
1144: */
1145: nc->delayed = 1;
1146: } else {
1.103 markus 1147: port_open_helper(nc, rtype);
1.137 markus 1148: }
1.41 markus 1149: }
1150: }
1.25 markus 1151:
1.41 markus 1152: /*
1153: * This is the authentication agent socket listening for connections from
1154: * clients.
1155: */
1.127 itojun 1156: static void
1.41 markus 1157: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1158: {
1.113 markus 1159: Channel *nc;
1.121 markus 1160: char *name;
1.113 markus 1161: int newsock;
1.41 markus 1162: struct sockaddr addr;
1163: socklen_t addrlen;
1.25 markus 1164:
1.41 markus 1165: if (FD_ISSET(c->sock, readset)) {
1166: addrlen = sizeof(addr);
1167: newsock = accept(c->sock, &addr, &addrlen);
1168: if (newsock < 0) {
1169: error("accept from auth socket: %.100s", strerror(errno));
1170: return;
1171: }
1.121 markus 1172: name = xstrdup("accepted auth socket");
1.113 markus 1173: nc = channel_new("accepted auth socket",
1.73 markus 1174: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1175: c->local_window_max, c->local_maxpacket,
1.121 markus 1176: 0, name, 1);
1.73 markus 1177: if (compat20) {
1178: packet_start(SSH2_MSG_CHANNEL_OPEN);
1179: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1180: packet_put_int(nc->self);
1.73 markus 1181: packet_put_int(c->local_window_max);
1182: packet_put_int(c->local_maxpacket);
1183: } else {
1184: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1185: packet_put_int(nc->self);
1.73 markus 1186: }
1.41 markus 1187: packet_send();
1188: }
1189: }
1.25 markus 1190:
1.127 itojun 1191: static void
1.75 markus 1192: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1193: {
1.114 markus 1194: int err = 0;
1.129 stevesk 1195: socklen_t sz = sizeof(err);
1.114 markus 1196:
1.75 markus 1197: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1198: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1199: err = errno;
1200: error("getsockopt SO_ERROR failed");
1201: }
1202: if (err == 0) {
1203: debug("channel %d: connected", c->self);
1204: c->type = SSH_CHANNEL_OPEN;
1205: if (compat20) {
1206: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1207: packet_put_int(c->remote_id);
1208: packet_put_int(c->self);
1209: packet_put_int(c->local_window);
1210: packet_put_int(c->local_maxpacket);
1211: } else {
1212: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1213: packet_put_int(c->remote_id);
1214: packet_put_int(c->self);
1215: }
1.75 markus 1216: } else {
1.114 markus 1217: debug("channel %d: not connected: %s",
1218: c->self, strerror(err));
1219: if (compat20) {
1220: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1221: packet_put_int(c->remote_id);
1222: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1223: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1224: packet_put_cstring(strerror(err));
1225: packet_put_cstring("");
1226: }
1.75 markus 1227: } else {
1.114 markus 1228: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1229: packet_put_int(c->remote_id);
1.75 markus 1230: }
1.114 markus 1231: chan_mark_dead(c);
1.75 markus 1232: }
1.114 markus 1233: packet_send();
1.75 markus 1234: }
1235: }
1236:
1.127 itojun 1237: static int
1.41 markus 1238: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1239: {
1240: char buf[16*1024];
1241: int len;
1.25 markus 1242:
1.118 markus 1243: if (c->rfd != -1 &&
1.41 markus 1244: FD_ISSET(c->rfd, readset)) {
1245: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1246: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1247: return 1;
1.41 markus 1248: if (len <= 0) {
1.51 markus 1249: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1250: c->self, c->rfd, len);
1.104 markus 1251: if (c->type != SSH_CHANNEL_OPEN) {
1252: debug("channel %d: not open", c->self);
1.113 markus 1253: chan_mark_dead(c);
1.103 markus 1254: return -1;
1.104 markus 1255: } else if (compat13) {
1.158 markus 1256: buffer_clear(&c->output);
1.41 markus 1257: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.121 markus 1258: debug("channel %d: input draining.", c->self);
1.25 markus 1259: } else {
1.41 markus 1260: chan_read_failed(c);
1.25 markus 1261: }
1.41 markus 1262: return -1;
1263: }
1.143 deraadt 1264: if (c->input_filter != NULL) {
1.66 markus 1265: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 1266: debug("channel %d: filter stops", c->self);
1.65 markus 1267: chan_read_failed(c);
1268: }
1269: } else {
1270: buffer_append(&c->input, buf, len);
1271: }
1.41 markus 1272: }
1273: return 1;
1274: }
1.127 itojun 1275: static int
1.41 markus 1276: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1277: {
1.95 markus 1278: struct termios tio;
1.134 markus 1279: u_char *data;
1280: u_int dlen;
1.41 markus 1281: int len;
1.25 markus 1282:
1.41 markus 1283: /* Send buffered output data to the socket. */
1.118 markus 1284: if (c->wfd != -1 &&
1.41 markus 1285: FD_ISSET(c->wfd, writeset) &&
1286: buffer_len(&c->output) > 0) {
1.134 markus 1287: data = buffer_ptr(&c->output);
1288: dlen = buffer_len(&c->output);
1289: len = write(c->wfd, data, dlen);
1.53 markus 1290: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1291: return 1;
1.41 markus 1292: if (len <= 0) {
1.104 markus 1293: if (c->type != SSH_CHANNEL_OPEN) {
1294: debug("channel %d: not open", c->self);
1.113 markus 1295: chan_mark_dead(c);
1.104 markus 1296: return -1;
1297: } else if (compat13) {
1.158 markus 1298: buffer_clear(&c->output);
1.121 markus 1299: debug("channel %d: input draining.", c->self);
1.41 markus 1300: c->type = SSH_CHANNEL_INPUT_DRAINING;
1301: } else {
1302: chan_write_failed(c);
1303: }
1304: return -1;
1.91 markus 1305: }
1.134 markus 1306: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1307: if (tcgetattr(c->wfd, &tio) == 0 &&
1308: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1309: /*
1310: * Simulate echo to reduce the impact of
1.96 markus 1311: * traffic analysis. We need to match the
1.95 markus 1312: * size of a SSH2_MSG_CHANNEL_DATA message
1313: * (4 byte channel id + data)
1.91 markus 1314: */
1.95 markus 1315: packet_send_ignore(4 + len);
1.91 markus 1316: packet_send();
1317: }
1.25 markus 1318: }
1.41 markus 1319: buffer_consume(&c->output, len);
1.44 markus 1320: if (compat20 && len > 0) {
1321: c->local_consumed += len;
1322: }
1323: }
1324: return 1;
1325: }
1.127 itojun 1326: static int
1.44 markus 1327: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1328: {
1329: char buf[16*1024];
1330: int len;
1331:
1.45 markus 1332: /** XXX handle drain efd, too */
1.44 markus 1333: if (c->efd != -1) {
1334: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1335: FD_ISSET(c->efd, writeset) &&
1336: buffer_len(&c->extended) > 0) {
1337: len = write(c->efd, buffer_ptr(&c->extended),
1338: buffer_len(&c->extended));
1.70 markus 1339: debug2("channel %d: written %d to efd %d",
1.44 markus 1340: c->self, len, c->efd);
1.93 markus 1341: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1342: return 1;
1343: if (len <= 0) {
1344: debug2("channel %d: closing write-efd %d",
1345: c->self, c->efd);
1.132 markus 1346: channel_close_fd(&c->efd);
1.93 markus 1347: } else {
1.44 markus 1348: buffer_consume(&c->extended, len);
1349: c->local_consumed += len;
1350: }
1351: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1352: FD_ISSET(c->efd, readset)) {
1353: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1354: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1355: c->self, len, c->efd);
1.93 markus 1356: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1357: return 1;
1358: if (len <= 0) {
1359: debug2("channel %d: closing read-efd %d",
1.45 markus 1360: c->self, c->efd);
1.132 markus 1361: channel_close_fd(&c->efd);
1.93 markus 1362: } else {
1.44 markus 1363: buffer_append(&c->extended, buf, len);
1.93 markus 1364: }
1.44 markus 1365: }
1366: }
1367: return 1;
1368: }
1.127 itojun 1369: static int
1.93 markus 1370: channel_check_window(Channel *c)
1.44 markus 1371: {
1.104 markus 1372: if (c->type == SSH_CHANNEL_OPEN &&
1373: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1374: c->local_window < c->local_window_max/2 &&
1375: c->local_consumed > 0) {
1376: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1377: packet_put_int(c->remote_id);
1378: packet_put_int(c->local_consumed);
1379: packet_send();
1.70 markus 1380: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1381: c->self, c->local_window,
1382: c->local_consumed);
1383: c->local_window += c->local_consumed;
1384: c->local_consumed = 0;
1.1 deraadt 1385: }
1.41 markus 1386: return 1;
1.1 deraadt 1387: }
1388:
1.127 itojun 1389: static void
1.157 markus 1390: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1391: {
1.137 markus 1392: if (c->delayed)
1393: return;
1.41 markus 1394: channel_handle_rfd(c, readset, writeset);
1395: channel_handle_wfd(c, readset, writeset);
1.157 markus 1396: if (!compat20)
1.137 markus 1397: return;
1.44 markus 1398: channel_handle_efd(c, readset, writeset);
1.93 markus 1399: channel_check_window(c);
1.44 markus 1400: }
1401:
1.127 itojun 1402: static void
1.41 markus 1403: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1404: {
1.41 markus 1405: int len;
1.180 deraadt 1406:
1.41 markus 1407: /* Send buffered output data to the socket. */
1408: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1409: len = write(c->sock, buffer_ptr(&c->output),
1410: buffer_len(&c->output));
1411: if (len <= 0)
1.158 markus 1412: buffer_clear(&c->output);
1.41 markus 1413: else
1414: buffer_consume(&c->output, len);
1415: }
1416: }
1.25 markus 1417:
1.127 itojun 1418: static void
1.44 markus 1419: channel_handler_init_20(void)
1420: {
1.157 markus 1421: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1422: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1423: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1424: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1425: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1426: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1427: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1428: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1429:
1.157 markus 1430: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1431: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1432: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1433: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1434: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1435: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1436: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1437: }
1438:
1.127 itojun 1439: static void
1.41 markus 1440: channel_handler_init_13(void)
1441: {
1442: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1443: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1444: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1445: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1446: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1447: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1448: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1449: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1450: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1451:
1.157 markus 1452: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1453: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1454: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1455: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1456: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1457: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1458: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1459: }
1.25 markus 1460:
1.127 itojun 1461: static void
1.41 markus 1462: channel_handler_init_15(void)
1463: {
1.157 markus 1464: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1465: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1466: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1467: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1468: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1469: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1470: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1471:
1.41 markus 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;
1.157 markus 1475: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1476: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1477: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1478: }
1.27 markus 1479:
1.127 itojun 1480: static void
1.41 markus 1481: channel_handler_init(void)
1482: {
1483: int i;
1.180 deraadt 1484:
1.148 deraadt 1485: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1486: channel_pre[i] = NULL;
1487: channel_post[i] = NULL;
1488: }
1.44 markus 1489: if (compat20)
1490: channel_handler_init_20();
1491: else if (compat13)
1.41 markus 1492: channel_handler_init_13();
1493: else
1494: channel_handler_init_15();
1495: }
1.25 markus 1496:
1.140 markus 1497: /* gc dead channels */
1498: static void
1499: channel_garbage_collect(Channel *c)
1500: {
1501: if (c == NULL)
1502: return;
1503: if (c->detach_user != NULL) {
1504: if (!chan_is_dead(c, 0))
1505: return;
1506: debug("channel %d: gc: notify user", c->self);
1507: c->detach_user(c->self, NULL);
1508: /* if we still have a callback */
1509: if (c->detach_user != NULL)
1510: return;
1511: debug("channel %d: gc: user detached", c->self);
1512: }
1513: if (!chan_is_dead(c, 1))
1514: return;
1515: debug("channel %d: garbage collecting", c->self);
1516: channel_free(c);
1517: }
1518:
1.127 itojun 1519: static void
1.41 markus 1520: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1521: {
1522: static int did_init = 0;
1523: int i;
1524: Channel *c;
1.25 markus 1525:
1.41 markus 1526: if (!did_init) {
1527: channel_handler_init();
1528: did_init = 1;
1529: }
1530: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1531: c = channels[i];
1532: if (c == NULL)
1.41 markus 1533: continue;
1.118 markus 1534: if (ftab[c->type] != NULL)
1535: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1536: channel_garbage_collect(c);
1.1 deraadt 1537: }
1538: }
1539:
1.121 markus 1540: /*
1541: * Allocate/update select bitmasks and add any bits relevant to channels in
1542: * select bitmasks.
1543: */
1.49 markus 1544: void
1.100 markus 1545: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1546: int *nallocp, int rekeying)
1.41 markus 1547: {
1.84 markus 1548: int n;
1549: u_int sz;
1550:
1551: n = MAX(*maxfdp, channel_max_fd);
1552:
1553: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1554: /* perhaps check sz < nalloc/2 and shrink? */
1555: if (*readsetp == NULL || sz > *nallocp) {
1556: *readsetp = xrealloc(*readsetp, sz);
1557: *writesetp = xrealloc(*writesetp, sz);
1558: *nallocp = sz;
1.84 markus 1559: }
1.132 markus 1560: *maxfdp = n;
1.84 markus 1561: memset(*readsetp, 0, sz);
1562: memset(*writesetp, 0, sz);
1563:
1.100 markus 1564: if (!rekeying)
1565: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1566: }
1567:
1.121 markus 1568: /*
1569: * After select, perform any appropriate operations for channels which have
1570: * events pending.
1571: */
1.49 markus 1572: void
1.41 markus 1573: channel_after_select(fd_set * readset, fd_set * writeset)
1574: {
1575: channel_handler(channel_post, readset, writeset);
1576: }
1577:
1.121 markus 1578:
1.84 markus 1579: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1580:
1.49 markus 1581: void
1.142 itojun 1582: channel_output_poll(void)
1.1 deraadt 1583: {
1.41 markus 1584: Channel *c;
1.178 markus 1585: int i;
1586: u_int len;
1.1 deraadt 1587:
1.25 markus 1588: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1589: c = channels[i];
1590: if (c == NULL)
1591: continue;
1.37 markus 1592:
1.121 markus 1593: /*
1594: * We are only interested in channels that can have buffered
1595: * incoming data.
1596: */
1.37 markus 1597: if (compat13) {
1.41 markus 1598: if (c->type != SSH_CHANNEL_OPEN &&
1599: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1600: continue;
1601: } else {
1.41 markus 1602: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1603: continue;
1604: }
1.46 markus 1605: if (compat20 &&
1606: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1607: /* XXX is this true? */
1.140 markus 1608: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1609: continue;
1610: }
1.25 markus 1611:
1612: /* Get the amount of buffered data for this channel. */
1.93 markus 1613: if ((c->istate == CHAN_INPUT_OPEN ||
1614: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1615: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1616: /*
1617: * Send some data for the other side over the secure
1618: * connection.
1619: */
1.44 markus 1620: if (compat20) {
1621: if (len > c->remote_window)
1622: len = c->remote_window;
1623: if (len > c->remote_maxpacket)
1624: len = c->remote_maxpacket;
1.25 markus 1625: } else {
1.44 markus 1626: if (packet_is_interactive()) {
1627: if (len > 1024)
1628: len = 512;
1629: } else {
1630: /* Keep the packets at reasonable size. */
1631: if (len > packet_get_maxsize()/2)
1632: len = packet_get_maxsize()/2;
1633: }
1.25 markus 1634: }
1.41 markus 1635: if (len > 0) {
1.44 markus 1636: packet_start(compat20 ?
1637: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1638: packet_put_int(c->remote_id);
1639: packet_put_string(buffer_ptr(&c->input), len);
1640: packet_send();
1641: buffer_consume(&c->input, len);
1642: c->remote_window -= len;
1643: }
1644: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1645: if (compat13)
1646: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1647: /*
1648: * input-buffer is empty and read-socket shutdown:
1.172 markus 1649: * tell peer, that we will not send more data: send IEOF.
1650: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1651: */
1.172 markus 1652: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.174 markus 1653: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1654: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1655: else
1656: chan_ibuf_empty(c);
1.25 markus 1657: }
1.44 markus 1658: /* Send extended data, i.e. stderr */
1659: if (compat20 &&
1.172 markus 1660: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1661: c->remote_window > 0 &&
1662: (len = buffer_len(&c->extended)) > 0 &&
1663: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1664: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1665: c->self, c->remote_window, buffer_len(&c->extended),
1666: c->extended_usage);
1.44 markus 1667: if (len > c->remote_window)
1668: len = c->remote_window;
1669: if (len > c->remote_maxpacket)
1670: len = c->remote_maxpacket;
1671: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1672: packet_put_int(c->remote_id);
1673: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1674: packet_put_string(buffer_ptr(&c->extended), len);
1675: packet_send();
1676: buffer_consume(&c->extended, len);
1677: c->remote_window -= len;
1.93 markus 1678: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1679: }
1.25 markus 1680: }
1.1 deraadt 1681: }
1682:
1.121 markus 1683:
1684: /* -- protocol input */
1.1 deraadt 1685:
1.49 markus 1686: void
1.154 markus 1687: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1688: {
1.37 markus 1689: int id;
1.25 markus 1690: char *data;
1.77 markus 1691: u_int data_len;
1.41 markus 1692: Channel *c;
1.25 markus 1693:
1694: /* Get the channel number and verify it. */
1.37 markus 1695: id = packet_get_int();
1.41 markus 1696: c = channel_lookup(id);
1697: if (c == NULL)
1.37 markus 1698: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1699:
1700: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1701: if (c->type != SSH_CHANNEL_OPEN &&
1702: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1703: return;
1704:
1705: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1706: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1707: return;
1708:
1709: /* Get the data. */
1710: data = packet_get_string(&data_len);
1.41 markus 1711:
1.143 deraadt 1712: if (compat20) {
1.44 markus 1713: if (data_len > c->local_maxpacket) {
1714: log("channel %d: rcvd big packet %d, maxpack %d",
1715: c->self, data_len, c->local_maxpacket);
1716: }
1717: if (data_len > c->local_window) {
1718: log("channel %d: rcvd too much data %d, win %d",
1719: c->self, data_len, c->local_window);
1720: xfree(data);
1721: return;
1722: }
1723: c->local_window -= data_len;
1724: }
1.152 markus 1725: packet_check_eom();
1.41 markus 1726: buffer_append(&c->output, data, data_len);
1.25 markus 1727: xfree(data);
1.1 deraadt 1728: }
1.121 markus 1729:
1.49 markus 1730: void
1.154 markus 1731: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1732: {
1733: int id;
1734: char *data;
1.177 markus 1735: u_int data_len, tcode;
1.44 markus 1736: Channel *c;
1737:
1738: /* Get the channel number and verify it. */
1739: id = packet_get_int();
1740: c = channel_lookup(id);
1741:
1742: if (c == NULL)
1743: packet_disconnect("Received extended_data for bad channel %d.", id);
1744: if (c->type != SSH_CHANNEL_OPEN) {
1745: log("channel %d: ext data for non open", id);
1746: return;
1.172 markus 1747: }
1748: if (c->flags & CHAN_EOF_RCVD) {
1749: if (datafellows & SSH_BUG_EXTEOF)
1750: debug("channel %d: accepting ext data after eof", id);
1751: else
1752: packet_disconnect("Received extended_data after EOF "
1753: "on channel %d.", id);
1.44 markus 1754: }
1755: tcode = packet_get_int();
1756: if (c->efd == -1 ||
1757: c->extended_usage != CHAN_EXTENDED_WRITE ||
1758: tcode != SSH2_EXTENDED_DATA_STDERR) {
1759: log("channel %d: bad ext data", c->self);
1760: return;
1761: }
1762: data = packet_get_string(&data_len);
1.152 markus 1763: packet_check_eom();
1.44 markus 1764: if (data_len > c->local_window) {
1765: log("channel %d: rcvd too much extended_data %d, win %d",
1766: c->self, data_len, c->local_window);
1767: xfree(data);
1768: return;
1769: }
1.70 markus 1770: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1771: c->local_window -= data_len;
1772: buffer_append(&c->extended, data, data_len);
1773: xfree(data);
1774: }
1775:
1.49 markus 1776: void
1.154 markus 1777: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1778: {
1779: int id;
1780: Channel *c;
1781:
1782: id = packet_get_int();
1.152 markus 1783: packet_check_eom();
1.41 markus 1784: c = channel_lookup(id);
1785: if (c == NULL)
1786: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1787: chan_rcvd_ieof(c);
1.133 markus 1788:
1789: /* XXX force input close */
1.156 markus 1790: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1791: debug("channel %d: FORCE input drain", c->self);
1792: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1793: if (buffer_len(&c->input) == 0)
1794: chan_ibuf_empty(c);
1.133 markus 1795: }
1796:
1.41 markus 1797: }
1.1 deraadt 1798:
1.49 markus 1799: void
1.154 markus 1800: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1801: {
1.41 markus 1802: int id;
1803: Channel *c;
1.1 deraadt 1804:
1.41 markus 1805: id = packet_get_int();
1.152 markus 1806: packet_check_eom();
1.41 markus 1807: c = channel_lookup(id);
1808: if (c == NULL)
1809: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1810:
1811: /*
1812: * Send a confirmation that we have closed the channel and no more
1813: * data is coming for it.
1814: */
1.25 markus 1815: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1816: packet_put_int(c->remote_id);
1.25 markus 1817: packet_send();
1818:
1.27 markus 1819: /*
1820: * If the channel is in closed state, we have sent a close request,
1821: * and the other side will eventually respond with a confirmation.
1822: * Thus, we cannot free the channel here, because then there would be
1823: * no-one to receive the confirmation. The channel gets freed when
1824: * the confirmation arrives.
1825: */
1.41 markus 1826: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1827: /*
1828: * Not a closed channel - mark it as draining, which will
1829: * cause it to be freed later.
1830: */
1.158 markus 1831: buffer_clear(&c->input);
1.41 markus 1832: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1833: }
1.1 deraadt 1834: }
1835:
1.41 markus 1836: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1837: void
1.154 markus 1838: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1839: {
1840: int id = packet_get_int();
1841: Channel *c = channel_lookup(id);
1.151 markus 1842:
1.152 markus 1843: packet_check_eom();
1.41 markus 1844: if (c == NULL)
1845: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1846: chan_rcvd_oclose(c);
1847: }
1.1 deraadt 1848:
1.49 markus 1849: void
1.154 markus 1850: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1851: {
1.41 markus 1852: int id = packet_get_int();
1853: Channel *c = channel_lookup(id);
1.1 deraadt 1854:
1.152 markus 1855: packet_check_eom();
1.41 markus 1856: if (c == NULL)
1857: packet_disconnect("Received close confirmation for "
1858: "out-of-range channel %d.", id);
1859: if (c->type != SSH_CHANNEL_CLOSED)
1860: packet_disconnect("Received close confirmation for "
1861: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1862: channel_free(c);
1.1 deraadt 1863: }
1864:
1.49 markus 1865: void
1.154 markus 1866: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1867: {
1.41 markus 1868: int id, remote_id;
1869: Channel *c;
1.1 deraadt 1870:
1.41 markus 1871: id = packet_get_int();
1872: c = channel_lookup(id);
1.25 markus 1873:
1.41 markus 1874: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1875: packet_disconnect("Received open confirmation for "
1876: "non-opening channel %d.", id);
1877: remote_id = packet_get_int();
1.27 markus 1878: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1879: c->remote_id = remote_id;
1880: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1881:
1882: if (compat20) {
1883: c->remote_window = packet_get_int();
1884: c->remote_maxpacket = packet_get_int();
1.165 markus 1885: if (c->confirm) {
1.70 markus 1886: debug2("callback start");
1.165 markus 1887: c->confirm(c->self, NULL);
1.70 markus 1888: debug2("callback done");
1.44 markus 1889: }
1.178 markus 1890: debug("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 1891: c->remote_window, c->remote_maxpacket);
1892: }
1.152 markus 1893: packet_check_eom();
1.1 deraadt 1894: }
1895:
1.127 itojun 1896: static char *
1.114 markus 1897: reason2txt(int reason)
1898: {
1.143 deraadt 1899: switch (reason) {
1.114 markus 1900: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1901: return "administratively prohibited";
1902: case SSH2_OPEN_CONNECT_FAILED:
1903: return "connect failed";
1904: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1905: return "unknown channel type";
1906: case SSH2_OPEN_RESOURCE_SHORTAGE:
1907: return "resource shortage";
1908: }
1.117 stevesk 1909: return "unknown reason";
1.114 markus 1910: }
1911:
1.49 markus 1912: void
1.154 markus 1913: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1914: {
1.86 markus 1915: int id, reason;
1916: char *msg = NULL, *lang = NULL;
1.41 markus 1917: Channel *c;
1918:
1919: id = packet_get_int();
1920: c = channel_lookup(id);
1.25 markus 1921:
1.41 markus 1922: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1923: packet_disconnect("Received open failure for "
1924: "non-opening channel %d.", id);
1.44 markus 1925: if (compat20) {
1.86 markus 1926: reason = packet_get_int();
1.110 markus 1927: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1928: msg = packet_get_string(NULL);
1929: lang = packet_get_string(NULL);
1930: }
1.114 markus 1931: log("channel %d: open failed: %s%s%s", id,
1932: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1933: if (msg != NULL)
1934: xfree(msg);
1935: if (lang != NULL)
1936: xfree(lang);
1.44 markus 1937: }
1.152 markus 1938: packet_check_eom();
1.25 markus 1939: /* Free the channel. This will also close the socket. */
1.113 markus 1940: channel_free(c);
1.44 markus 1941: }
1942:
1.121 markus 1943: void
1.154 markus 1944: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 1945: {
1946: Channel *c;
1.178 markus 1947: int id;
1948: u_int adjust;
1.121 markus 1949:
1950: if (!compat20)
1951: return;
1952:
1953: /* Get the channel number and verify it. */
1954: id = packet_get_int();
1955: c = channel_lookup(id);
1.1 deraadt 1956:
1.121 markus 1957: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1958: log("Received window adjust for "
1959: "non-open channel %d.", id);
1960: return;
1961: }
1962: adjust = packet_get_int();
1.152 markus 1963: packet_check_eom();
1.178 markus 1964: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 1965: c->remote_window += adjust;
1966: }
1.1 deraadt 1967:
1.121 markus 1968: void
1.154 markus 1969: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1970: {
1.121 markus 1971: Channel *c = NULL;
1972: u_short host_port;
1973: char *host, *originator_string;
1974: int remote_id, sock = -1;
1975:
1976: remote_id = packet_get_int();
1977: host = packet_get_string(NULL);
1978: host_port = packet_get_int();
1.25 markus 1979:
1.121 markus 1980: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1981: originator_string = packet_get_string(NULL);
1982: } else {
1983: originator_string = xstrdup("unknown (remote did not supply name)");
1984: }
1.152 markus 1985: packet_check_eom();
1.121 markus 1986: sock = channel_connect_to(host, host_port);
1987: if (sock != -1) {
1988: c = channel_new("connected socket",
1989: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
1990: originator_string, 1);
1.167 markus 1991: c->remote_id = remote_id;
1.25 markus 1992: }
1.121 markus 1993: if (c == NULL) {
1994: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1995: packet_put_int(remote_id);
1996: packet_send();
1997: }
1998: xfree(host);
1.1 deraadt 1999: }
2000:
1.121 markus 2001:
2002: /* -- tcp forwarding */
1.135 markus 2003:
2004: void
2005: channel_set_af(int af)
2006: {
2007: IPv4or6 = af;
2008: }
1.121 markus 2009:
1.160 markus 2010: static int
2011: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2012: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2013: {
1.113 markus 2014: Channel *c;
1.160 markus 2015: int success, sock, on = 1;
1.35 markus 2016: struct addrinfo hints, *ai, *aitop;
1.160 markus 2017: const char *host;
1.35 markus 2018: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2019:
1.87 markus 2020: success = 0;
1.160 markus 2021: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2022: listen_addr : host_to_connect;
1.87 markus 2023:
1.160 markus 2024: if (host == NULL) {
2025: error("No forward host name.");
2026: return success;
1.73 markus 2027: }
1.113 markus 2028: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2029: error("Forward host name too long.");
2030: return success;
2031: }
1.25 markus 2032:
1.28 markus 2033: /*
1.35 markus 2034: * getaddrinfo returns a loopback address if the hostname is
2035: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2036: */
1.35 markus 2037: memset(&hints, 0, sizeof(hints));
2038: hints.ai_family = IPv4or6;
2039: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2040: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2041: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2042: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2043: packet_disconnect("getaddrinfo: fatal error");
2044:
2045: for (ai = aitop; ai; ai = ai->ai_next) {
2046: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2047: continue;
2048: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2049: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2050: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2051: continue;
2052: }
2053: /* Create a port to listen for the host. */
2054: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2055: if (sock < 0) {
2056: /* this is no error since kernel may not support ipv6 */
2057: verbose("socket: %.100s", strerror(errno));
2058: continue;
2059: }
2060: /*
1.182 stevesk 2061: * Set socket options.
2062: * Allow local port reuse in TIME_WAIT.
1.35 markus 2063: */
1.182 stevesk 2064: if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
2065: sizeof(on)) == -1)
2066: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
2067:
1.35 markus 2068: debug("Local forwarding listening on %s port %s.", ntop, strport);
2069:
2070: /* Bind the socket to the address. */
2071: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2072: /* address can be in use ipv6 address is already bound */
2073: verbose("bind: %.100s", strerror(errno));
2074: close(sock);
2075: continue;
2076: }
2077: /* Start listening for connections on the socket. */
2078: if (listen(sock, 5) < 0) {
2079: error("listen: %.100s", strerror(errno));
2080: close(sock);
2081: continue;
2082: }
2083: /* Allocate a channel number for the socket. */
1.121 markus 2084: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2085: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2086: 0, xstrdup("port listener"), 1);
1.113 markus 2087: strlcpy(c->path, host, sizeof(c->path));
2088: c->host_port = port_to_connect;
2089: c->listening_port = listen_port;
1.35 markus 2090: success = 1;
2091: }
2092: if (success == 0)
1.160 markus 2093: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2094: listen_port);
1.35 markus 2095: freeaddrinfo(aitop);
1.87 markus 2096: return success;
1.25 markus 2097: }
1.1 deraadt 2098:
1.160 markus 2099: /* protocol local port fwd, used by ssh (and sshd in v1) */
2100: int
2101: channel_setup_local_fwd_listener(u_short listen_port,
2102: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2103: {
2104: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2105: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2106: }
2107:
2108: /* protocol v2 remote port fwd, used by sshd */
2109: int
2110: channel_setup_remote_fwd_listener(const char *listen_address,
2111: u_short listen_port, int gateway_ports)
2112: {
2113: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2114: listen_address, listen_port, NULL, 0, gateway_ports);
2115: }
2116:
1.27 markus 2117: /*
2118: * Initiate forwarding of connections to port "port" on remote host through
2119: * the secure channel to host:port from local side.
2120: */
1.1 deraadt 2121:
1.49 markus 2122: void
1.73 markus 2123: channel_request_remote_forwarding(u_short listen_port,
2124: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2125: {
1.153 markus 2126: int type, success = 0;
1.73 markus 2127:
1.25 markus 2128: /* Record locally that connection to this host/port is permitted. */
2129: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2130: fatal("channel_request_remote_forwarding: too many forwards");
2131:
2132: /* Send the forward request to the remote side. */
1.44 markus 2133: if (compat20) {
2134: const char *address_to_bind = "0.0.0.0";
2135: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2136: packet_put_cstring("tcpip-forward");
1.173 markus 2137: packet_put_char(1); /* boolean: want reply */
1.44 markus 2138: packet_put_cstring(address_to_bind);
2139: packet_put_int(listen_port);
1.73 markus 2140: packet_send();
2141: packet_write_wait();
2142: /* Assume that server accepts the request */
2143: success = 1;
1.44 markus 2144: } else {
2145: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2146: packet_put_int(listen_port);
2147: packet_put_cstring(host_to_connect);
1.44 markus 2148: packet_put_int(port_to_connect);
2149: packet_send();
2150: packet_write_wait();
1.73 markus 2151:
2152: /* Wait for response from the remote side. */
1.153 markus 2153: type = packet_read();
1.73 markus 2154: switch (type) {
2155: case SSH_SMSG_SUCCESS:
2156: success = 1;
2157: break;
2158: case SSH_SMSG_FAILURE:
2159: log("Warning: Server denied remote port forwarding.");
2160: break;
2161: default:
2162: /* Unknown packet */
2163: packet_disconnect("Protocol error for port forward request:"
2164: "received packet type %d.", type);
2165: }
2166: }
2167: if (success) {
2168: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2169: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2170: permitted_opens[num_permitted_opens].listen_port = listen_port;
2171: num_permitted_opens++;
1.44 markus 2172: }
1.1 deraadt 2173: }
2174:
1.27 markus 2175: /*
2176: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2177: * listening for the port, and sends back a success reply (or disconnect
2178: * message if there was an error). This never returns if there was an error.
2179: */
1.1 deraadt 2180:
1.49 markus 2181: void
1.56 markus 2182: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2183: {
1.31 markus 2184: u_short port, host_port;
1.25 markus 2185: char *hostname;
1.1 deraadt 2186:
1.25 markus 2187: /* Get arguments from the packet. */
2188: port = packet_get_int();
2189: hostname = packet_get_string(NULL);
2190: host_port = packet_get_int();
2191:
1.27 markus 2192: /*
2193: * Check that an unprivileged user is not trying to forward a
2194: * privileged port.
2195: */
1.25 markus 2196: if (port < IPPORT_RESERVED && !is_root)
2197: packet_disconnect("Requested forwarding of port %d but user is not root.",
2198: port);
1.73 markus 2199: /* Initiate forwarding */
1.160 markus 2200: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2201:
2202: /* Free the argument string. */
2203: xfree(hostname);
1.1 deraadt 2204: }
2205:
1.99 markus 2206: /*
2207: * Permits opening to any host/port if permitted_opens[] is empty. This is
2208: * usually called by the server, because the user could connect to any port
2209: * anyway, and the server has no way to know but to trust the client anyway.
2210: */
2211: void
1.142 itojun 2212: channel_permit_all_opens(void)
1.99 markus 2213: {
2214: if (num_permitted_opens == 0)
2215: all_opens_permitted = 1;
2216: }
2217:
1.101 markus 2218: void
1.99 markus 2219: channel_add_permitted_opens(char *host, int port)
2220: {
2221: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2222: fatal("channel_request_remote_forwarding: too many forwards");
2223: debug("allow port forwarding to host %s port %d", host, port);
2224:
2225: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2226: permitted_opens[num_permitted_opens].port_to_connect = port;
2227: num_permitted_opens++;
2228:
2229: all_opens_permitted = 0;
2230: }
2231:
1.101 markus 2232: void
1.99 markus 2233: channel_clear_permitted_opens(void)
2234: {
2235: int i;
2236:
2237: for (i = 0; i < num_permitted_opens; i++)
2238: xfree(permitted_opens[i].host_to_connect);
2239: num_permitted_opens = 0;
2240:
2241: }
2242:
2243:
2244: /* return socket to remote host, port */
1.127 itojun 2245: static int
1.99 markus 2246: connect_to(const char *host, u_short port)
1.41 markus 2247: {
2248: struct addrinfo hints, *ai, *aitop;
2249: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2250: int gaierr;
2251: int sock = -1;
2252:
2253: memset(&hints, 0, sizeof(hints));
2254: hints.ai_family = IPv4or6;
2255: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2256: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2257: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2258: error("connect_to %.100s: unknown host (%s)", host,
2259: gai_strerror(gaierr));
1.41 markus 2260: return -1;
2261: }
2262: for (ai = aitop; ai; ai = ai->ai_next) {
2263: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2264: continue;
2265: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2266: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2267: error("connect_to: getnameinfo failed");
1.41 markus 2268: continue;
2269: }
2270: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2271: if (sock < 0) {
1.186 ! djm 2272: if (ai->ai_next == NULL)
! 2273: error("socket: %.100s", strerror(errno));
! 2274: else
! 2275: verbose("socket: %.100s", strerror(errno));
1.41 markus 2276: continue;
2277: }
1.80 markus 2278: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2279: fatal("connect_to: F_SETFL: %s", strerror(errno));
2280: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2281: errno != EINPROGRESS) {
1.99 markus 2282: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2283: strerror(errno));
2284: close(sock);
1.89 stevesk 2285: continue; /* fail -- try next */
1.41 markus 2286: }
2287: break; /* success */
2288:
2289: }
2290: freeaddrinfo(aitop);
2291: if (!ai) {
1.99 markus 2292: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2293: return -1;
2294: }
2295: /* success */
1.169 stevesk 2296: set_nodelay(sock);
1.41 markus 2297: return sock;
2298: }
1.99 markus 2299:
1.73 markus 2300: int
1.130 stevesk 2301: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2302: {
2303: int i;
1.99 markus 2304:
1.73 markus 2305: for (i = 0; i < num_permitted_opens; i++)
2306: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2307: return connect_to(
1.73 markus 2308: permitted_opens[i].host_to_connect,
2309: permitted_opens[i].port_to_connect);
1.74 markus 2310: error("WARNING: Server requests forwarding for unknown listen_port %d",
2311: listen_port);
1.73 markus 2312: return -1;
2313: }
2314:
1.99 markus 2315: /* Check if connecting to that port is permitted and connect. */
2316: int
2317: channel_connect_to(const char *host, u_short port)
2318: {
2319: int i, permit;
2320:
2321: permit = all_opens_permitted;
2322: if (!permit) {
2323: for (i = 0; i < num_permitted_opens; i++)
2324: if (permitted_opens[i].port_to_connect == port &&
2325: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2326: permit = 1;
2327:
2328: }
2329: if (!permit) {
2330: log("Received request to connect to host %.100s port %d, "
2331: "but the request was denied.", host, port);
2332: return -1;
2333: }
2334: return connect_to(host, port);
2335: }
2336:
1.121 markus 2337: /* -- X11 forwarding */
1.1 deraadt 2338:
1.27 markus 2339: /*
2340: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2341: * Returns 0 and a suitable display number for the DISPLAY variable
2342: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2343: */
1.141 stevesk 2344: int
1.163 stevesk 2345: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.176 deraadt 2346: int single_connection, u_int *display_numberp)
1.1 deraadt 2347: {
1.149 markus 2348: Channel *nc = NULL;
1.31 markus 2349: int display_number, sock;
2350: u_short port;
1.35 markus 2351: struct addrinfo hints, *ai, *aitop;
2352: char strport[NI_MAXSERV];
2353: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2354:
1.33 markus 2355: for (display_number = x11_display_offset;
1.148 deraadt 2356: display_number < MAX_DISPLAYS;
2357: display_number++) {
1.25 markus 2358: port = 6000 + display_number;
1.35 markus 2359: memset(&hints, 0, sizeof(hints));
2360: hints.ai_family = IPv4or6;
1.163 stevesk 2361: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2362: hints.ai_socktype = SOCK_STREAM;
2363: snprintf(strport, sizeof strport, "%d", port);
2364: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2365: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2366: return -1;
1.25 markus 2367: }
1.35 markus 2368: for (ai = aitop; ai; ai = ai->ai_next) {
2369: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2370: continue;
2371: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2372: if (sock < 0) {
2373: error("socket: %.100s", strerror(errno));
1.141 stevesk 2374: return -1;
1.35 markus 2375: }
2376: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2377: debug("bind port %d: %.100s", port, strerror(errno));
2378: close(sock);
1.183 itojun 2379:
2380: if (ai->ai_next)
2381: continue;
2382:
1.35 markus 2383: for (n = 0; n < num_socks; n++) {
2384: close(socks[n]);
2385: }
2386: num_socks = 0;
2387: break;
2388: }
2389: socks[num_socks++] = sock;
2390: if (num_socks == NUM_SOCKS)
2391: break;
1.25 markus 2392: }
1.83 stevesk 2393: freeaddrinfo(aitop);
1.35 markus 2394: if (num_socks > 0)
2395: break;
1.25 markus 2396: }
2397: if (display_number >= MAX_DISPLAYS) {
2398: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2399: return -1;
1.25 markus 2400: }
2401: /* Start listening for connections on the socket. */
1.35 markus 2402: for (n = 0; n < num_socks; n++) {
2403: sock = socks[n];
2404: if (listen(sock, 5) < 0) {
2405: error("listen: %.100s", strerror(errno));
2406: close(sock);
1.141 stevesk 2407: return -1;
1.35 markus 2408: }
1.25 markus 2409: }
1.35 markus 2410:
2411: /* Allocate a channel for each socket. */
2412: for (n = 0; n < num_socks; n++) {
2413: sock = socks[n];
1.149 markus 2414: nc = channel_new("x11 listener",
1.51 markus 2415: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2416: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2417: 0, xstrdup("X11 inet listener"), 1);
1.167 markus 2418: nc->single_connection = single_connection;
1.35 markus 2419: }
1.1 deraadt 2420:
1.141 stevesk 2421: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2422: *display_numberp = display_number;
2423: return (0);
1.1 deraadt 2424: }
2425:
1.127 itojun 2426: static int
1.77 markus 2427: connect_local_xsocket(u_int dnr)
1.1 deraadt 2428: {
1.25 markus 2429: int sock;
2430: struct sockaddr_un addr;
2431:
1.147 stevesk 2432: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2433: if (sock < 0)
2434: error("socket: %.100s", strerror(errno));
2435: memset(&addr, 0, sizeof(addr));
2436: addr.sun_family = AF_UNIX;
2437: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2438: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2439: return sock;
2440: close(sock);
1.25 markus 2441: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2442: return -1;
1.1 deraadt 2443: }
2444:
1.51 markus 2445: int
2446: x11_connect_display(void)
1.1 deraadt 2447: {
1.162 stevesk 2448: int display_number, sock = 0;
1.25 markus 2449: const char *display;
1.51 markus 2450: char buf[1024], *cp;
1.35 markus 2451: struct addrinfo hints, *ai, *aitop;
2452: char strport[NI_MAXSERV];
2453: int gaierr;
1.25 markus 2454:
2455: /* Try to open a socket for the local X server. */
2456: display = getenv("DISPLAY");
2457: if (!display) {
2458: error("DISPLAY not set.");
1.51 markus 2459: return -1;
1.25 markus 2460: }
1.27 markus 2461: /*
2462: * Now we decode the value of the DISPLAY variable and make a
2463: * connection to the real X server.
2464: */
2465:
2466: /*
2467: * Check if it is a unix domain socket. Unix domain displays are in
2468: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2469: */
1.25 markus 2470: if (strncmp(display, "unix:", 5) == 0 ||
2471: display[0] == ':') {
2472: /* Connect to the unix domain socket. */
2473: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2474: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2475: display);
1.51 markus 2476: return -1;
1.25 markus 2477: }
2478: /* Create a socket. */
2479: sock = connect_local_xsocket(display_number);
2480: if (sock < 0)
1.51 markus 2481: return -1;
1.25 markus 2482:
2483: /* OK, we now have a connection to the display. */
1.51 markus 2484: return sock;
1.25 markus 2485: }
1.27 markus 2486: /*
2487: * Connect to an inet socket. The DISPLAY value is supposedly
2488: * hostname:d[.s], where hostname may also be numeric IP address.
2489: */
1.145 stevesk 2490: strlcpy(buf, display, sizeof(buf));
1.25 markus 2491: cp = strchr(buf, ':');
2492: if (!cp) {
2493: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2494: return -1;
1.25 markus 2495: }
2496: *cp = 0;
1.27 markus 2497: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2498: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2499: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2500: display);
1.51 markus 2501: return -1;
1.25 markus 2502: }
1.35 markus 2503:
2504: /* Look up the host address */
2505: memset(&hints, 0, sizeof(hints));
2506: hints.ai_family = IPv4or6;
2507: hints.ai_socktype = SOCK_STREAM;
2508: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2509: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2510: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2511: return -1;
1.25 markus 2512: }
1.35 markus 2513: for (ai = aitop; ai; ai = ai->ai_next) {
2514: /* Create a socket. */
2515: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2516: if (sock < 0) {
2517: debug("socket: %.100s", strerror(errno));
1.41 markus 2518: continue;
2519: }
2520: /* Connect it to the display. */
2521: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2522: debug("connect %.100s port %d: %.100s", buf,
2523: 6000 + display_number, strerror(errno));
2524: close(sock);
2525: continue;
2526: }
2527: /* Success */
2528: break;
1.35 markus 2529: }
2530: freeaddrinfo(aitop);
2531: if (!ai) {
1.49 markus 2532: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2533: strerror(errno));
1.51 markus 2534: return -1;
1.25 markus 2535: }
1.162 stevesk 2536: set_nodelay(sock);
1.51 markus 2537: return sock;
2538: }
2539:
2540: /*
2541: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2542: * the remote channel number. We should do whatever we want, and respond
2543: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2544: */
2545:
2546: void
1.154 markus 2547: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2548: {
1.113 markus 2549: Channel *c = NULL;
2550: int remote_id, sock = 0;
1.51 markus 2551: char *remote_host;
1.25 markus 2552:
1.113 markus 2553: debug("Received X11 open request.");
1.51 markus 2554:
1.113 markus 2555: remote_id = packet_get_int();
1.121 markus 2556:
2557: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2558: remote_host = packet_get_string(NULL);
1.51 markus 2559: } else {
2560: remote_host = xstrdup("unknown (remote did not supply name)");
2561: }
1.152 markus 2562: packet_check_eom();
1.25 markus 2563:
1.51 markus 2564: /* Obtain a connection to the real X display. */
2565: sock = x11_connect_display();
1.113 markus 2566: if (sock != -1) {
2567: /* Allocate a channel for this connection. */
2568: c = channel_new("connected x11 socket",
2569: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2570: remote_host, 1);
1.167 markus 2571: c->remote_id = remote_id;
2572: c->force_drain = 1;
1.113 markus 2573: }
2574: if (c == NULL) {
1.51 markus 2575: /* Send refusal to the remote host. */
2576: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2577: packet_put_int(remote_id);
1.51 markus 2578: } else {
2579: /* Send a confirmation to the remote host. */
2580: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2581: packet_put_int(remote_id);
2582: packet_put_int(c->self);
1.51 markus 2583: }
1.113 markus 2584: packet_send();
1.72 markus 2585: }
2586:
2587: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2588: void
1.154 markus 2589: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2590: {
2591: int rchan = packet_get_int();
1.180 deraadt 2592:
1.143 deraadt 2593: switch (type) {
1.72 markus 2594: case SSH_SMSG_AGENT_OPEN:
2595: error("Warning: ssh server tried agent forwarding.");
2596: break;
2597: case SSH_SMSG_X11_OPEN:
2598: error("Warning: ssh server tried X11 forwarding.");
2599: break;
2600: default:
1.154 markus 2601: error("deny_input_open: type %d", type);
1.72 markus 2602: break;
2603: }
2604: error("Warning: this is probably a break in attempt by a malicious server.");
2605: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2606: packet_put_int(rchan);
2607: packet_send();
1.1 deraadt 2608: }
2609:
1.27 markus 2610: /*
2611: * Requests forwarding of X11 connections, generates fake authentication
2612: * data, and enables authentication spoofing.
1.121 markus 2613: * This should be called in the client only.
1.27 markus 2614: */
1.49 markus 2615: void
1.51 markus 2616: x11_request_forwarding_with_spoofing(int client_session_id,
2617: const char *proto, const char *data)
1.1 deraadt 2618: {
1.77 markus 2619: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2620: u_int i, value, len;
1.25 markus 2621: char *new_data;
2622: int screen_number;
2623: const char *cp;
2624: u_int32_t rand = 0;
2625:
2626: cp = getenv("DISPLAY");
2627: if (cp)
2628: cp = strchr(cp, ':');
2629: if (cp)
2630: cp = strchr(cp, '.');
2631: if (cp)
2632: screen_number = atoi(cp + 1);
2633: else
2634: screen_number = 0;
2635:
2636: /* Save protocol name. */
2637: x11_saved_proto = xstrdup(proto);
2638:
1.27 markus 2639: /*
2640: * Extract real authentication data and generate fake data of the
2641: * same length.
2642: */
1.25 markus 2643: x11_saved_data = xmalloc(data_len);
2644: x11_fake_data = xmalloc(data_len);
2645: for (i = 0; i < data_len; i++) {
2646: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2647: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2648: if (i % 4 == 0)
2649: rand = arc4random();
2650: x11_saved_data[i] = value;
2651: x11_fake_data[i] = rand & 0xff;
2652: rand >>= 8;
2653: }
2654: x11_saved_data_len = data_len;
2655: x11_fake_data_len = data_len;
2656:
2657: /* Convert the fake data into hex. */
1.90 markus 2658: len = 2 * data_len + 1;
2659: new_data = xmalloc(len);
1.25 markus 2660: for (i = 0; i < data_len; i++)
1.90 markus 2661: snprintf(new_data + 2 * i, len - 2 * i,
2662: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2663:
2664: /* Send the request packet. */
1.51 markus 2665: if (compat20) {
2666: channel_request_start(client_session_id, "x11-req", 0);
2667: packet_put_char(0); /* XXX bool single connection */
2668: } else {
2669: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2670: }
2671: packet_put_cstring(proto);
2672: packet_put_cstring(new_data);
1.25 markus 2673: packet_put_int(screen_number);
2674: packet_send();
2675: packet_write_wait();
2676: xfree(new_data);
1.1 deraadt 2677: }
2678:
1.121 markus 2679:
2680: /* -- agent forwarding */
2681:
1.1 deraadt 2682: /* Sends a message to the server to request authentication fd forwarding. */
2683:
1.49 markus 2684: void
1.142 itojun 2685: auth_request_forwarding(void)
1.1 deraadt 2686: {
1.25 markus 2687: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2688: packet_send();
2689: packet_write_wait();
1.1 deraadt 2690: }
2691:
2692: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2693:
1.49 markus 2694: void
1.154 markus 2695: auth_input_open_request(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2696: {
1.113 markus 2697: Channel *c = NULL;
2698: int remote_id, sock;
1.121 markus 2699: char *name;
1.41 markus 2700:
1.25 markus 2701: /* Read the remote channel number from the message. */
1.113 markus 2702: remote_id = packet_get_int();
1.152 markus 2703: packet_check_eom();
1.25 markus 2704:
1.27 markus 2705: /*
2706: * Get a connection to the local authentication agent (this may again
2707: * get forwarded).
2708: */
1.25 markus 2709: sock = ssh_get_authentication_socket();
2710:
1.27 markus 2711: /*
2712: * If we could not connect the agent, send an error message back to
2713: * the server. This should never happen unless the agent dies,
2714: * because authentication forwarding is only enabled if we have an
2715: * agent.
2716: */
1.113 markus 2717: if (sock >= 0) {
1.121 markus 2718: name = xstrdup("authentication agent connection");
2719: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
2720: -1, 0, 0, 0, name, 1);
1.167 markus 2721: c->remote_id = remote_id;
2722: c->force_drain = 1;
1.113 markus 2723: }
2724: if (c == NULL) {
1.25 markus 2725: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2726: packet_put_int(remote_id);
2727: } else {
2728: /* Send a confirmation to the remote host. */
2729: debug("Forwarding authentication connection.");
2730: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2731: packet_put_int(remote_id);
2732: packet_put_int(c->self);
1.25 markus 2733: }
2734: packet_send();
1.1 deraadt 2735: }
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