Annotation of src/usr.bin/ssh/channels.c, Revision 1.255
1.255 ! stevesk 1: /* $OpenBSD: channels.c,v 1.254 2006/07/11 20:07:25 stevesk Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.234 stevesk 43:
44: #include <sys/ioctl.h>
1.235 stevesk 45: #include <sys/types.h>
46: #include <sys/un.h>
1.251 stevesk 47: #include <sys/socket.h>
48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.255 ! stevesk 53: #include <netdb.h>
1.233 stevesk 54: #include <termios.h>
1.1 deraadt 55:
56: #include "ssh.h"
1.82 markus 57: #include "ssh1.h"
58: #include "ssh2.h"
1.1 deraadt 59: #include "packet.h"
60: #include "xmalloc.h"
1.82 markus 61: #include "log.h"
62: #include "misc.h"
1.14 markus 63: #include "channels.h"
64: #include "compat.h"
1.82 markus 65: #include "canohost.h"
1.64 markus 66: #include "key.h"
67: #include "authfd.h"
1.147 stevesk 68: #include "pathnames.h"
1.193 markus 69: #include "bufaux.h"
1.1 deraadt 70:
1.121 markus 71: /* -- channel core */
1.12 markus 72:
1.27 markus 73: /*
74: * Pointer to an array containing all allocated channels. The array is
75: * dynamically extended as needed.
76: */
1.113 markus 77: static Channel **channels = NULL;
1.1 deraadt 78:
1.27 markus 79: /*
80: * Size of the channel array. All slots of the array must always be
1.113 markus 81: * initialized (at least the type field); unused slots set to NULL
1.27 markus 82: */
1.209 avsm 83: static u_int channels_alloc = 0;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 87: * updated in channel_new.
1.27 markus 88: */
1.84 markus 89: static int channel_max_fd = 0;
1.1 deraadt 90:
91:
1.121 markus 92: /* -- tcp forwarding */
1.1 deraadt 93:
1.27 markus 94: /*
95: * Data structure for storing which hosts are permitted for forward requests.
96: * The local sides of any remote forwards are stored in this array to prevent
97: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
98: * network (which might be behind a firewall).
99: */
1.25 markus 100: typedef struct {
1.41 markus 101: char *host_to_connect; /* Connect to 'host'. */
102: u_short port_to_connect; /* Connect to 'port'. */
103: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 104: } ForwardPermission;
105:
106: /* List of all permitted host/port pairs to connect. */
107: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 108:
1.1 deraadt 109: /* Number of permitted host/port pairs in the array. */
110: static int num_permitted_opens = 0;
1.27 markus 111: /*
112: * If this is true, all opens are permitted. This is the case on the server
113: * on which we have to trust the client anyway, and the user could do
114: * anything after logging in anyway.
115: */
1.1 deraadt 116: static int all_opens_permitted = 0;
117:
1.121 markus 118:
119: /* -- X11 forwarding */
120:
121: /* Maximum number of fake X11 displays to try. */
122: #define MAX_DISPLAYS 1000
123:
1.219 djm 124: /* Saved X11 local (client) display. */
125: static char *x11_saved_display = NULL;
126:
1.121 markus 127: /* Saved X11 authentication protocol name. */
128: static char *x11_saved_proto = NULL;
129:
130: /* Saved X11 authentication data. This is the real data. */
131: static char *x11_saved_data = NULL;
132: static u_int x11_saved_data_len = 0;
133:
134: /*
135: * Fake X11 authentication data. This is what the server will be sending us;
136: * we should replace any occurrences of this by the real data.
137: */
1.240 deraadt 138: static u_char *x11_fake_data = NULL;
1.121 markus 139: static u_int x11_fake_data_len;
140:
141:
142: /* -- agent forwarding */
143:
144: #define NUM_SOCKS 10
145:
1.82 markus 146: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 147: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 148:
1.121 markus 149: /* helper */
1.127 itojun 150: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 151:
1.121 markus 152: /* -- channel core */
1.41 markus 153:
154: Channel *
1.229 markus 155: channel_by_id(int id)
1.41 markus 156: {
157: Channel *c;
1.113 markus 158:
1.209 avsm 159: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 160: logit("channel_by_id: %d: bad id", id);
1.41 markus 161: return NULL;
162: }
1.113 markus 163: c = channels[id];
164: if (c == NULL) {
1.229 markus 165: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 166: return NULL;
167: }
168: return c;
1.55 markus 169: }
170:
1.27 markus 171: /*
1.229 markus 172: * Returns the channel if it is allowed to receive protocol messages.
173: * Private channels, like listening sockets, may not receive messages.
174: */
175: Channel *
176: channel_lookup(int id)
177: {
178: Channel *c;
179:
180: if ((c = channel_by_id(id)) == NULL)
181: return (NULL);
182:
1.237 deraadt 183: switch (c->type) {
1.229 markus 184: case SSH_CHANNEL_X11_OPEN:
185: case SSH_CHANNEL_LARVAL:
186: case SSH_CHANNEL_CONNECTING:
187: case SSH_CHANNEL_DYNAMIC:
188: case SSH_CHANNEL_OPENING:
189: case SSH_CHANNEL_OPEN:
190: case SSH_CHANNEL_INPUT_DRAINING:
191: case SSH_CHANNEL_OUTPUT_DRAINING:
192: return (c);
193: }
194: logit("Non-public channel %d, type %d.", id, c->type);
195: return (NULL);
196: }
197:
198: /*
1.55 markus 199: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 200: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 201: */
1.127 itojun 202: static void
1.71 markus 203: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
204: int extusage, int nonblock)
1.1 deraadt 205: {
1.25 markus 206: /* Update the maximum file descriptor value. */
1.84 markus 207: channel_max_fd = MAX(channel_max_fd, rfd);
208: channel_max_fd = MAX(channel_max_fd, wfd);
209: channel_max_fd = MAX(channel_max_fd, efd);
210:
1.27 markus 211: /* XXX set close-on-exec -markus */
1.55 markus 212:
1.52 markus 213: c->rfd = rfd;
214: c->wfd = wfd;
215: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 216: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 217: c->efd = efd;
218: c->extended_usage = extusage;
1.71 markus 219:
1.91 markus 220: /* XXX ugly hack: nonblock is only set by the server */
221: if (nonblock && isatty(c->rfd)) {
1.194 markus 222: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 223: c->isatty = 1;
224: if (!isatty(c->wfd)) {
1.94 markus 225: error("channel %d: wfd %d is not a tty?",
1.91 markus 226: c->self, c->wfd);
227: }
228: } else {
229: c->isatty = 0;
230: }
231:
1.71 markus 232: /* enable nonblocking mode */
233: if (nonblock) {
234: if (rfd != -1)
235: set_nonblock(rfd);
236: if (wfd != -1)
237: set_nonblock(wfd);
238: if (efd != -1)
239: set_nonblock(efd);
240: }
1.52 markus 241: }
242:
243: /*
244: * Allocate a new channel object and set its type and socket. This will cause
245: * remote_name to be freed.
246: */
1.113 markus 247: Channel *
1.52 markus 248: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 249: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 250: {
1.209 avsm 251: int found;
252: u_int i;
1.52 markus 253: Channel *c;
1.25 markus 254:
255: /* Do initial allocation if this is the first call. */
256: if (channels_alloc == 0) {
257: channels_alloc = 10;
1.242 djm 258: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 259: for (i = 0; i < channels_alloc; i++)
1.113 markus 260: channels[i] = NULL;
1.25 markus 261: }
262: /* Try to find a free slot where to put the new channel. */
263: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 264: if (channels[i] == NULL) {
1.25 markus 265: /* Found a free slot. */
1.209 avsm 266: found = (int)i;
1.25 markus 267: break;
268: }
1.209 avsm 269: if (found < 0) {
1.27 markus 270: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 271: found = channels_alloc;
1.179 markus 272: if (channels_alloc > 10000)
273: fatal("channel_new: internal error: channels_alloc %d "
274: "too big.", channels_alloc);
1.243 djm 275: channels = xrealloc(channels, channels_alloc + 10,
276: sizeof(Channel *));
1.195 markus 277: channels_alloc += 10;
1.70 markus 278: debug2("channel: expanding %d", channels_alloc);
1.25 markus 279: for (i = found; i < channels_alloc; i++)
1.113 markus 280: channels[i] = NULL;
1.25 markus 281: }
1.113 markus 282: /* Initialize and return new channel. */
1.242 djm 283: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 284: buffer_init(&c->input);
285: buffer_init(&c->output);
1.41 markus 286: buffer_init(&c->extended);
1.159 markus 287: c->ostate = CHAN_OUTPUT_OPEN;
288: c->istate = CHAN_INPUT_OPEN;
289: c->flags = 0;
1.71 markus 290: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 291: c->self = found;
292: c->type = type;
1.41 markus 293: c->ctype = ctype;
1.51 markus 294: c->local_window = window;
295: c->local_window_max = window;
296: c->local_consumed = 0;
297: c->local_maxpacket = maxpack;
1.25 markus 298: c->remote_id = -1;
1.190 markus 299: c->remote_name = xstrdup(remote_name);
1.41 markus 300: c->remote_window = 0;
301: c->remote_maxpacket = 0;
1.133 markus 302: c->force_drain = 0;
1.149 markus 303: c->single_connection = 0;
1.131 markus 304: c->detach_user = NULL;
1.225 djm 305: c->detach_close = 0;
1.165 markus 306: c->confirm = NULL;
1.204 djm 307: c->confirm_ctx = NULL;
1.65 markus 308: c->input_filter = NULL;
1.231 reyk 309: c->output_filter = NULL;
1.25 markus 310: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 311: return c;
1.1 deraadt 312: }
1.52 markus 313:
1.132 markus 314: static int
315: channel_find_maxfd(void)
316: {
1.209 avsm 317: u_int i;
318: int max = 0;
1.132 markus 319: Channel *c;
320:
321: for (i = 0; i < channels_alloc; i++) {
322: c = channels[i];
323: if (c != NULL) {
324: max = MAX(max, c->rfd);
325: max = MAX(max, c->wfd);
326: max = MAX(max, c->efd);
327: }
328: }
329: return max;
330: }
331:
332: int
333: channel_close_fd(int *fdp)
334: {
335: int ret = 0, fd = *fdp;
336:
337: if (fd != -1) {
338: ret = close(fd);
339: *fdp = -1;
340: if (fd == channel_max_fd)
341: channel_max_fd = channel_find_maxfd();
342: }
343: return ret;
344: }
345:
1.52 markus 346: /* Close all channel fd/socket. */
1.127 itojun 347: static void
1.52 markus 348: channel_close_fds(Channel *c)
349: {
1.204 djm 350: debug3("channel %d: close_fds r %d w %d e %d c %d",
351: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 352:
1.132 markus 353: channel_close_fd(&c->sock);
1.204 djm 354: channel_close_fd(&c->ctl_fd);
1.132 markus 355: channel_close_fd(&c->rfd);
356: channel_close_fd(&c->wfd);
357: channel_close_fd(&c->efd);
1.121 markus 358: }
359:
360: /* Free the channel and close its fd/socket. */
361: void
362: channel_free(Channel *c)
363: {
364: char *s;
1.209 avsm 365: u_int i, n;
1.121 markus 366:
367: for (n = 0, i = 0; i < channels_alloc; i++)
368: if (channels[i])
369: n++;
1.209 avsm 370: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 371: c->remote_name ? c->remote_name : "???", n);
372:
373: s = channel_open_message();
1.194 markus 374: debug3("channel %d: status: %s", c->self, s);
1.121 markus 375: xfree(s);
376:
377: if (c->sock != -1)
378: shutdown(c->sock, SHUT_RDWR);
1.204 djm 379: if (c->ctl_fd != -1)
380: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 381: channel_close_fds(c);
382: buffer_free(&c->input);
383: buffer_free(&c->output);
384: buffer_free(&c->extended);
385: if (c->remote_name) {
386: xfree(c->remote_name);
387: c->remote_name = NULL;
388: }
389: channels[c->self] = NULL;
390: xfree(c);
391: }
392:
393: void
1.126 markus 394: channel_free_all(void)
1.121 markus 395: {
1.209 avsm 396: u_int i;
1.121 markus 397:
1.126 markus 398: for (i = 0; i < channels_alloc; i++)
399: if (channels[i] != NULL)
400: channel_free(channels[i]);
1.131 markus 401: }
402:
1.121 markus 403: /*
404: * Closes the sockets/fds of all channels. This is used to close extra file
405: * descriptors after a fork.
406: */
407: void
1.142 itojun 408: channel_close_all(void)
1.121 markus 409: {
1.209 avsm 410: u_int i;
1.121 markus 411:
412: for (i = 0; i < channels_alloc; i++)
413: if (channels[i] != NULL)
414: channel_close_fds(channels[i]);
415: }
416:
417: /*
1.131 markus 418: * Stop listening to channels.
419: */
420: void
421: channel_stop_listening(void)
422: {
1.209 avsm 423: u_int i;
1.131 markus 424: Channel *c;
425:
426: for (i = 0; i < channels_alloc; i++) {
427: c = channels[i];
428: if (c != NULL) {
429: switch (c->type) {
430: case SSH_CHANNEL_AUTH_SOCKET:
431: case SSH_CHANNEL_PORT_LISTENER:
432: case SSH_CHANNEL_RPORT_LISTENER:
433: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 434: channel_close_fd(&c->sock);
1.131 markus 435: channel_free(c);
436: break;
437: }
438: }
439: }
440: }
441:
442: /*
1.121 markus 443: * Returns true if no channel has too much buffered data, and false if one or
444: * more channel is overfull.
445: */
446: int
1.142 itojun 447: channel_not_very_much_buffered_data(void)
1.121 markus 448: {
449: u_int i;
450: Channel *c;
451:
452: for (i = 0; i < channels_alloc; i++) {
453: c = channels[i];
454: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 455: #if 0
456: if (!compat20 &&
457: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 458: debug2("channel %d: big input buffer %d",
1.121 markus 459: c->self, buffer_len(&c->input));
460: return 0;
461: }
1.136 markus 462: #endif
1.121 markus 463: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 464: debug2("channel %d: big output buffer %u > %u",
1.136 markus 465: c->self, buffer_len(&c->output),
466: packet_get_maxsize());
1.121 markus 467: return 0;
468: }
469: }
470: }
471: return 1;
472: }
473:
474: /* Returns true if any channel is still open. */
475: int
1.142 itojun 476: channel_still_open(void)
1.121 markus 477: {
1.209 avsm 478: u_int i;
1.121 markus 479: Channel *c;
480:
481: for (i = 0; i < channels_alloc; i++) {
482: c = channels[i];
483: if (c == NULL)
484: continue;
485: switch (c->type) {
486: case SSH_CHANNEL_X11_LISTENER:
487: case SSH_CHANNEL_PORT_LISTENER:
488: case SSH_CHANNEL_RPORT_LISTENER:
489: case SSH_CHANNEL_CLOSED:
490: case SSH_CHANNEL_AUTH_SOCKET:
491: case SSH_CHANNEL_DYNAMIC:
492: case SSH_CHANNEL_CONNECTING:
493: case SSH_CHANNEL_ZOMBIE:
494: continue;
495: case SSH_CHANNEL_LARVAL:
496: if (!compat20)
497: fatal("cannot happen: SSH_CHANNEL_LARVAL");
498: continue;
499: case SSH_CHANNEL_OPENING:
500: case SSH_CHANNEL_OPEN:
501: case SSH_CHANNEL_X11_OPEN:
502: return 1;
503: case SSH_CHANNEL_INPUT_DRAINING:
504: case SSH_CHANNEL_OUTPUT_DRAINING:
505: if (!compat13)
506: fatal("cannot happen: OUT_DRAIN");
507: return 1;
508: default:
509: fatal("channel_still_open: bad channel type %d", c->type);
510: /* NOTREACHED */
511: }
512: }
513: return 0;
514: }
515:
516: /* Returns the id of an open channel suitable for keepaliving */
517: int
1.142 itojun 518: channel_find_open(void)
1.121 markus 519: {
1.209 avsm 520: u_int i;
1.121 markus 521: Channel *c;
522:
523: for (i = 0; i < channels_alloc; i++) {
524: c = channels[i];
1.206 djm 525: if (c == NULL || c->remote_id < 0)
1.121 markus 526: continue;
527: switch (c->type) {
528: case SSH_CHANNEL_CLOSED:
529: case SSH_CHANNEL_DYNAMIC:
530: case SSH_CHANNEL_X11_LISTENER:
531: case SSH_CHANNEL_PORT_LISTENER:
532: case SSH_CHANNEL_RPORT_LISTENER:
533: case SSH_CHANNEL_OPENING:
534: case SSH_CHANNEL_CONNECTING:
535: case SSH_CHANNEL_ZOMBIE:
536: continue;
537: case SSH_CHANNEL_LARVAL:
538: case SSH_CHANNEL_AUTH_SOCKET:
539: case SSH_CHANNEL_OPEN:
540: case SSH_CHANNEL_X11_OPEN:
541: return i;
542: case SSH_CHANNEL_INPUT_DRAINING:
543: case SSH_CHANNEL_OUTPUT_DRAINING:
544: if (!compat13)
545: fatal("cannot happen: OUT_DRAIN");
546: return i;
547: default:
548: fatal("channel_find_open: bad channel type %d", c->type);
549: /* NOTREACHED */
550: }
551: }
552: return -1;
553: }
554:
555:
556: /*
557: * Returns a message describing the currently open forwarded connections,
558: * suitable for sending to the client. The message contains crlf pairs for
559: * newlines.
560: */
561: char *
1.142 itojun 562: channel_open_message(void)
1.121 markus 563: {
564: Buffer buffer;
565: Channel *c;
566: char buf[1024], *cp;
1.209 avsm 567: u_int i;
1.121 markus 568:
569: buffer_init(&buffer);
570: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
571: buffer_append(&buffer, buf, strlen(buf));
572: for (i = 0; i < channels_alloc; i++) {
573: c = channels[i];
574: if (c == NULL)
575: continue;
576: switch (c->type) {
577: case SSH_CHANNEL_X11_LISTENER:
578: case SSH_CHANNEL_PORT_LISTENER:
579: case SSH_CHANNEL_RPORT_LISTENER:
580: case SSH_CHANNEL_CLOSED:
581: case SSH_CHANNEL_AUTH_SOCKET:
582: case SSH_CHANNEL_ZOMBIE:
583: continue;
584: case SSH_CHANNEL_LARVAL:
585: case SSH_CHANNEL_OPENING:
586: case SSH_CHANNEL_CONNECTING:
587: case SSH_CHANNEL_DYNAMIC:
588: case SSH_CHANNEL_OPEN:
589: case SSH_CHANNEL_X11_OPEN:
590: case SSH_CHANNEL_INPUT_DRAINING:
591: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 592: snprintf(buf, sizeof buf,
593: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 594: c->self, c->remote_name,
595: c->type, c->remote_id,
596: c->istate, buffer_len(&c->input),
597: c->ostate, buffer_len(&c->output),
1.204 djm 598: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 599: buffer_append(&buffer, buf, strlen(buf));
600: continue;
601: default:
602: fatal("channel_open_message: bad channel type %d", c->type);
603: /* NOTREACHED */
604: }
605: }
606: buffer_append(&buffer, "\0", 1);
607: cp = xstrdup(buffer_ptr(&buffer));
608: buffer_free(&buffer);
609: return cp;
610: }
611:
612: void
613: channel_send_open(int id)
614: {
615: Channel *c = channel_lookup(id);
1.180 deraadt 616:
1.121 markus 617: if (c == NULL) {
1.188 itojun 618: logit("channel_send_open: %d: bad id", id);
1.121 markus 619: return;
620: }
1.184 markus 621: debug2("channel %d: send open", id);
1.121 markus 622: packet_start(SSH2_MSG_CHANNEL_OPEN);
623: packet_put_cstring(c->ctype);
624: packet_put_int(c->self);
625: packet_put_int(c->local_window);
626: packet_put_int(c->local_maxpacket);
627: packet_send();
628: }
629:
630: void
1.184 markus 631: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 632: {
1.184 markus 633: Channel *c = channel_lookup(id);
1.180 deraadt 634:
1.121 markus 635: if (c == NULL) {
1.188 itojun 636: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 637: return;
638: }
1.204 djm 639: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 640: packet_start(SSH2_MSG_CHANNEL_REQUEST);
641: packet_put_int(c->remote_id);
642: packet_put_cstring(service);
643: packet_put_char(wantconfirm);
644: }
1.241 deraadt 645:
1.121 markus 646: void
1.204 djm 647: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 648: {
649: Channel *c = channel_lookup(id);
1.180 deraadt 650:
1.121 markus 651: if (c == NULL) {
1.188 itojun 652: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 653: return;
654: }
1.165 markus 655: c->confirm = fn;
1.204 djm 656: c->confirm_ctx = ctx;
1.121 markus 657: }
1.241 deraadt 658:
1.121 markus 659: void
1.225 djm 660: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 661: {
1.229 markus 662: Channel *c = channel_by_id(id);
1.180 deraadt 663:
1.121 markus 664: if (c == NULL) {
1.188 itojun 665: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 666: return;
667: }
1.131 markus 668: c->detach_user = fn;
1.225 djm 669: c->detach_close = do_close;
1.121 markus 670: }
1.241 deraadt 671:
1.121 markus 672: void
673: channel_cancel_cleanup(int id)
674: {
1.229 markus 675: Channel *c = channel_by_id(id);
1.180 deraadt 676:
1.121 markus 677: if (c == NULL) {
1.188 itojun 678: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 679: return;
1.52 markus 680: }
1.131 markus 681: c->detach_user = NULL;
1.225 djm 682: c->detach_close = 0;
1.121 markus 683: }
1.241 deraadt 684:
1.121 markus 685: void
1.231 reyk 686: channel_register_filter(int id, channel_infilter_fn *ifn,
687: channel_outfilter_fn *ofn)
1.121 markus 688: {
689: Channel *c = channel_lookup(id);
1.180 deraadt 690:
1.121 markus 691: if (c == NULL) {
1.188 itojun 692: logit("channel_register_filter: %d: bad id", id);
1.121 markus 693: return;
1.52 markus 694: }
1.231 reyk 695: c->input_filter = ifn;
696: c->output_filter = ofn;
1.52 markus 697: }
698:
1.49 markus 699: void
1.121 markus 700: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 701: int extusage, int nonblock, u_int window_max)
1.1 deraadt 702: {
1.121 markus 703: Channel *c = channel_lookup(id);
1.180 deraadt 704:
1.121 markus 705: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
706: fatal("channel_activate for non-larval channel %d.", id);
707: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
708: c->type = SSH_CHANNEL_OPEN;
1.168 markus 709: c->local_window = c->local_window_max = window_max;
1.121 markus 710: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
711: packet_put_int(c->remote_id);
712: packet_put_int(c->local_window);
713: packet_send();
1.1 deraadt 714: }
715:
1.27 markus 716: /*
1.41 markus 717: * 'channel_pre*' are called just before select() to add any bits relevant to
718: * channels in the select bitmasks.
719: */
720: /*
721: * 'channel_post*': perform any appropriate operations for channels which
722: * have events pending.
1.27 markus 723: */
1.237 deraadt 724: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 725: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
726: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
727:
1.127 itojun 728: static void
1.237 deraadt 729: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 730: {
731: FD_SET(c->sock, readset);
732: }
733:
1.127 itojun 734: static void
1.237 deraadt 735: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 736: {
737: debug3("channel %d: waiting for connection", c->self);
738: FD_SET(c->sock, writeset);
739: }
740:
1.127 itojun 741: static void
1.237 deraadt 742: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 743: {
744: if (buffer_len(&c->input) < packet_get_maxsize())
745: FD_SET(c->sock, readset);
746: if (buffer_len(&c->output) > 0)
747: FD_SET(c->sock, writeset);
748: }
1.1 deraadt 749:
1.127 itojun 750: static void
1.237 deraadt 751: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 752: {
1.157 markus 753: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 754:
1.44 markus 755: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 756: limit > 0 &&
1.250 djm 757: buffer_len(&c->input) < limit &&
758: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 759: FD_SET(c->rfd, readset);
760: if (c->ostate == CHAN_OUTPUT_OPEN ||
761: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
762: if (buffer_len(&c->output) > 0) {
763: FD_SET(c->wfd, writeset);
764: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 765: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 766: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
767: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 768: else
769: chan_obuf_empty(c);
1.44 markus 770: }
771: }
772: /** XXX check close conditions, too */
1.157 markus 773: if (compat20 && c->efd != -1) {
1.44 markus 774: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
775: buffer_len(&c->extended) > 0)
776: FD_SET(c->efd, writeset);
1.172 markus 777: else if (!(c->flags & CHAN_EOF_SENT) &&
778: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 779: buffer_len(&c->extended) < c->remote_window)
780: FD_SET(c->efd, readset);
781: }
1.204 djm 782: /* XXX: What about efd? races? */
1.208 deraadt 783: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 784: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
785: FD_SET(c->ctl_fd, readset);
1.44 markus 786: }
787:
1.127 itojun 788: static void
1.237 deraadt 789: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 790: {
791: if (buffer_len(&c->input) == 0) {
792: packet_start(SSH_MSG_CHANNEL_CLOSE);
793: packet_put_int(c->remote_id);
794: packet_send();
795: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 796: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 797: }
798: }
799:
1.127 itojun 800: static void
1.237 deraadt 801: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 802: {
803: if (buffer_len(&c->output) == 0)
1.113 markus 804: chan_mark_dead(c);
1.49 markus 805: else
1.41 markus 806: FD_SET(c->sock, writeset);
807: }
808:
809: /*
810: * This is a special state for X11 authentication spoofing. An opened X11
811: * connection (when authentication spoofing is being done) remains in this
812: * state until the first packet has been completely read. The authentication
813: * data in that packet is then substituted by the real data if it matches the
814: * fake data, and the channel is put into normal mode.
1.51 markus 815: * XXX All this happens at the client side.
1.121 markus 816: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 817: */
1.127 itojun 818: static int
1.121 markus 819: x11_open_helper(Buffer *b)
1.1 deraadt 820: {
1.77 markus 821: u_char *ucp;
822: u_int proto_len, data_len;
1.25 markus 823:
1.41 markus 824: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 825: if (buffer_len(b) < 12)
1.41 markus 826: return 0;
827:
828: /* Parse the lengths of variable-length fields. */
1.155 stevesk 829: ucp = buffer_ptr(b);
1.41 markus 830: if (ucp[0] == 0x42) { /* Byte order MSB first. */
831: proto_len = 256 * ucp[6] + ucp[7];
832: data_len = 256 * ucp[8] + ucp[9];
833: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
834: proto_len = ucp[6] + 256 * ucp[7];
835: data_len = ucp[8] + 256 * ucp[9];
836: } else {
1.194 markus 837: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 838: ucp[0]);
1.41 markus 839: return -1;
840: }
841:
842: /* Check if the whole packet is in buffer. */
1.121 markus 843: if (buffer_len(b) <
1.41 markus 844: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
845: return 0;
846:
847: /* Check if authentication protocol matches. */
848: if (proto_len != strlen(x11_saved_proto) ||
849: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 850: debug2("X11 connection uses different authentication protocol.");
1.41 markus 851: return -1;
852: }
853: /* Check if authentication data matches our fake data. */
854: if (data_len != x11_fake_data_len ||
855: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
856: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 857: debug2("X11 auth data does not match fake data.");
1.41 markus 858: return -1;
859: }
860: /* Check fake data length */
861: if (x11_fake_data_len != x11_saved_data_len) {
862: error("X11 fake_data_len %d != saved_data_len %d",
863: x11_fake_data_len, x11_saved_data_len);
864: return -1;
865: }
866: /*
867: * Received authentication protocol and data match
868: * our fake data. Substitute the fake data with real
869: * data.
870: */
871: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
872: x11_saved_data, x11_saved_data_len);
873: return 1;
874: }
875:
1.127 itojun 876: static void
1.237 deraadt 877: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 878: {
1.121 markus 879: int ret = x11_open_helper(&c->output);
1.180 deraadt 880:
1.41 markus 881: if (ret == 1) {
882: /* Start normal processing for the channel. */
883: c->type = SSH_CHANNEL_OPEN;
1.47 markus 884: channel_pre_open_13(c, readset, writeset);
1.41 markus 885: } else if (ret == -1) {
886: /*
887: * We have received an X11 connection that has bad
888: * authentication information.
889: */
1.188 itojun 890: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 891: buffer_clear(&c->input);
892: buffer_clear(&c->output);
1.132 markus 893: channel_close_fd(&c->sock);
1.41 markus 894: c->sock = -1;
895: c->type = SSH_CHANNEL_CLOSED;
896: packet_start(SSH_MSG_CHANNEL_CLOSE);
897: packet_put_int(c->remote_id);
898: packet_send();
899: }
900: }
1.25 markus 901:
1.127 itojun 902: static void
1.237 deraadt 903: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 904: {
1.121 markus 905: int ret = x11_open_helper(&c->output);
1.133 markus 906:
907: /* c->force_drain = 1; */
908:
1.41 markus 909: if (ret == 1) {
910: c->type = SSH_CHANNEL_OPEN;
1.157 markus 911: channel_pre_open(c, readset, writeset);
1.41 markus 912: } else if (ret == -1) {
1.188 itojun 913: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 914: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 915: chan_read_failed(c);
916: buffer_clear(&c->input);
917: chan_ibuf_empty(c);
918: buffer_clear(&c->output);
919: /* for proto v1, the peer will send an IEOF */
920: if (compat20)
921: chan_write_failed(c);
922: else
923: c->type = SSH_CHANNEL_OPEN;
1.194 markus 924: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 925: }
926: }
1.25 markus 927:
1.104 markus 928: /* try to decode a socks4 header */
1.127 itojun 929: static int
1.237 deraadt 930: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 931: {
1.181 markus 932: char *p, *host;
1.217 djm 933: u_int len, have, i, found;
1.148 deraadt 934: char username[256];
1.103 markus 935: struct {
936: u_int8_t version;
937: u_int8_t command;
938: u_int16_t dest_port;
1.104 markus 939: struct in_addr dest_addr;
1.103 markus 940: } s4_req, s4_rsp;
941:
1.104 markus 942: debug2("channel %d: decode socks4", c->self);
1.109 markus 943:
944: have = buffer_len(&c->input);
945: len = sizeof(s4_req);
946: if (have < len)
947: return 0;
948: p = buffer_ptr(&c->input);
949: for (found = 0, i = len; i < have; i++) {
950: if (p[i] == '\0') {
951: found = 1;
952: break;
953: }
954: if (i > 1024) {
955: /* the peer is probably sending garbage */
956: debug("channel %d: decode socks4: too long",
957: c->self);
958: return -1;
959: }
960: }
961: if (!found)
962: return 0;
1.103 markus 963: buffer_get(&c->input, (char *)&s4_req.version, 1);
964: buffer_get(&c->input, (char *)&s4_req.command, 1);
965: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 966: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 967: have = buffer_len(&c->input);
1.103 markus 968: p = buffer_ptr(&c->input);
969: len = strlen(p);
1.106 markus 970: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 971: if (len > have)
1.104 markus 972: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 973: c->self, len, have);
974: strlcpy(username, p, sizeof(username));
975: buffer_consume(&c->input, len);
976: buffer_consume(&c->input, 1); /* trailing '\0' */
977:
1.104 markus 978: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 979: strlcpy(c->path, host, sizeof(c->path));
980: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 981:
1.194 markus 982: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 983: c->self, host, c->host_port, s4_req.command);
1.103 markus 984:
1.104 markus 985: if (s4_req.command != 1) {
986: debug("channel %d: cannot handle: socks4 cn %d",
987: c->self, s4_req.command);
988: return -1;
1.103 markus 989: }
1.104 markus 990: s4_rsp.version = 0; /* vn: 0 for reply */
991: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 992: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 993: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 994: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 995: return 1;
996: }
997:
1.193 markus 998: /* try to decode a socks5 header */
999: #define SSH_SOCKS5_AUTHDONE 0x1000
1000: #define SSH_SOCKS5_NOAUTH 0x00
1001: #define SSH_SOCKS5_IPV4 0x01
1002: #define SSH_SOCKS5_DOMAIN 0x03
1003: #define SSH_SOCKS5_IPV6 0x04
1004: #define SSH_SOCKS5_CONNECT 0x01
1005: #define SSH_SOCKS5_SUCCESS 0x00
1006:
1007: static int
1.237 deraadt 1008: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1009: {
1010: struct {
1011: u_int8_t version;
1012: u_int8_t command;
1013: u_int8_t reserved;
1014: u_int8_t atyp;
1015: } s5_req, s5_rsp;
1016: u_int16_t dest_port;
1017: u_char *p, dest_addr[255+1];
1.252 djm 1018: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1019:
1020: debug2("channel %d: decode socks5", c->self);
1021: p = buffer_ptr(&c->input);
1022: if (p[0] != 0x05)
1023: return -1;
1024: have = buffer_len(&c->input);
1025: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1026: /* format: ver | nmethods | methods */
1.198 djm 1027: if (have < 2)
1.193 markus 1028: return 0;
1029: nmethods = p[1];
1030: if (have < nmethods + 2)
1031: return 0;
1032: /* look for method: "NO AUTHENTICATION REQUIRED" */
1033: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1034: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1035: found = 1;
1036: break;
1037: }
1038: }
1039: if (!found) {
1040: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1041: c->self);
1042: return -1;
1043: }
1044: buffer_consume(&c->input, nmethods + 2);
1045: buffer_put_char(&c->output, 0x05); /* version */
1046: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1047: FD_SET(c->sock, writeset);
1048: c->flags |= SSH_SOCKS5_AUTHDONE;
1049: debug2("channel %d: socks5 auth done", c->self);
1050: return 0; /* need more */
1051: }
1052: debug2("channel %d: socks5 post auth", c->self);
1053: if (have < sizeof(s5_req)+1)
1054: return 0; /* need more */
1.247 deraadt 1055: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1056: if (s5_req.version != 0x05 ||
1057: s5_req.command != SSH_SOCKS5_CONNECT ||
1058: s5_req.reserved != 0x00) {
1.194 markus 1059: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1060: return -1;
1061: }
1.213 deraadt 1062: switch (s5_req.atyp){
1.193 markus 1063: case SSH_SOCKS5_IPV4:
1064: addrlen = 4;
1065: af = AF_INET;
1066: break;
1067: case SSH_SOCKS5_DOMAIN:
1068: addrlen = p[sizeof(s5_req)];
1069: af = -1;
1070: break;
1071: case SSH_SOCKS5_IPV6:
1072: addrlen = 16;
1073: af = AF_INET6;
1074: break;
1075: default:
1.194 markus 1076: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1077: return -1;
1078: }
1.252 djm 1079: need = sizeof(s5_req) + addrlen + 2;
1080: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1081: need++;
1082: if (have < need)
1.193 markus 1083: return 0;
1084: buffer_consume(&c->input, sizeof(s5_req));
1085: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1086: buffer_consume(&c->input, 1); /* host string length */
1087: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1088: buffer_get(&c->input, (char *)&dest_port, 2);
1089: dest_addr[addrlen] = '\0';
1090: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1091: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1092: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1093: return -1;
1094: c->host_port = ntohs(dest_port);
1.198 djm 1095:
1.194 markus 1096: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1097: c->self, c->path, c->host_port, s5_req.command);
1098:
1099: s5_rsp.version = 0x05;
1100: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1101: s5_rsp.reserved = 0; /* ignored */
1102: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1103: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1104: dest_port = 0; /* ignored */
1105:
1.246 deraadt 1106: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1107: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1108: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1109: return 1;
1110: }
1111:
1.104 markus 1112: /* dynamic port forwarding */
1.127 itojun 1113: static void
1.237 deraadt 1114: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1115: {
1116: u_char *p;
1.217 djm 1117: u_int have;
1118: int ret;
1.103 markus 1119:
1.104 markus 1120: have = buffer_len(&c->input);
1.137 markus 1121: c->delayed = 0;
1.104 markus 1122: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1123: /* buffer_dump(&c->input); */
1.104 markus 1124: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1125: if (have < 3) {
1.104 markus 1126: /* need more */
1127: FD_SET(c->sock, readset);
1128: return;
1129: }
1130: /* try to guess the protocol */
1131: p = buffer_ptr(&c->input);
1132: switch (p[0]) {
1133: case 0x04:
1134: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1135: break;
1136: case 0x05:
1137: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1138: break;
1139: default:
1140: ret = -1;
1141: break;
1142: }
1143: if (ret < 0) {
1.113 markus 1144: chan_mark_dead(c);
1.104 markus 1145: } else if (ret == 0) {
1146: debug2("channel %d: pre_dynamic: need more", c->self);
1147: /* need more */
1148: FD_SET(c->sock, readset);
1149: } else {
1150: /* switch to the next state */
1151: c->type = SSH_CHANNEL_OPENING;
1152: port_open_helper(c, "direct-tcpip");
1153: }
1.103 markus 1154: }
1155:
1.41 markus 1156: /* This is our fake X11 server socket. */
1.127 itojun 1157: static void
1.237 deraadt 1158: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1159: {
1.113 markus 1160: Channel *nc;
1.41 markus 1161: struct sockaddr addr;
1.162 stevesk 1162: int newsock;
1.41 markus 1163: socklen_t addrlen;
1.85 markus 1164: char buf[16384], *remote_ipaddr;
1.51 markus 1165: int remote_port;
1.25 markus 1166:
1.41 markus 1167: if (FD_ISSET(c->sock, readset)) {
1168: debug("X11 connection requested.");
1169: addrlen = sizeof(addr);
1170: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1171: if (c->single_connection) {
1.194 markus 1172: debug2("single_connection: closing X11 listener.");
1.149 markus 1173: channel_close_fd(&c->sock);
1174: chan_mark_dead(c);
1175: }
1.41 markus 1176: if (newsock < 0) {
1177: error("accept: %.100s", strerror(errno));
1178: return;
1179: }
1.162 stevesk 1180: set_nodelay(newsock);
1.85 markus 1181: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1182: remote_port = get_peer_port(newsock);
1.41 markus 1183: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1184: remote_ipaddr, remote_port);
1.51 markus 1185:
1.113 markus 1186: nc = channel_new("accepted x11 socket",
1.51 markus 1187: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1188: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1189: if (compat20) {
1190: packet_start(SSH2_MSG_CHANNEL_OPEN);
1191: packet_put_cstring("x11");
1.113 markus 1192: packet_put_int(nc->self);
1.149 markus 1193: packet_put_int(nc->local_window_max);
1194: packet_put_int(nc->local_maxpacket);
1.85 markus 1195: /* originator ipaddr and port */
1196: packet_put_cstring(remote_ipaddr);
1.57 markus 1197: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1198: debug2("ssh2 x11 bug compat mode");
1.57 markus 1199: } else {
1200: packet_put_int(remote_port);
1201: }
1.51 markus 1202: packet_send();
1203: } else {
1204: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1205: packet_put_int(nc->self);
1.121 markus 1206: if (packet_get_protocol_flags() &
1207: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1208: packet_put_cstring(buf);
1.51 markus 1209: packet_send();
1210: }
1.85 markus 1211: xfree(remote_ipaddr);
1.41 markus 1212: }
1213: }
1.25 markus 1214:
1.127 itojun 1215: static void
1.103 markus 1216: port_open_helper(Channel *c, char *rtype)
1217: {
1218: int direct;
1219: char buf[1024];
1220: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1221: int remote_port = get_peer_port(c->sock);
1.103 markus 1222:
1223: direct = (strcmp(rtype, "direct-tcpip") == 0);
1224:
1225: snprintf(buf, sizeof buf,
1226: "%s: listening port %d for %.100s port %d, "
1227: "connect from %.200s port %d",
1228: rtype, c->listening_port, c->path, c->host_port,
1229: remote_ipaddr, remote_port);
1230:
1231: xfree(c->remote_name);
1232: c->remote_name = xstrdup(buf);
1233:
1234: if (compat20) {
1235: packet_start(SSH2_MSG_CHANNEL_OPEN);
1236: packet_put_cstring(rtype);
1237: packet_put_int(c->self);
1238: packet_put_int(c->local_window_max);
1239: packet_put_int(c->local_maxpacket);
1240: if (direct) {
1241: /* target host, port */
1242: packet_put_cstring(c->path);
1243: packet_put_int(c->host_port);
1244: } else {
1245: /* listen address, port */
1246: packet_put_cstring(c->path);
1247: packet_put_int(c->listening_port);
1248: }
1249: /* originator host and port */
1250: packet_put_cstring(remote_ipaddr);
1.216 markus 1251: packet_put_int((u_int)remote_port);
1.103 markus 1252: packet_send();
1253: } else {
1254: packet_start(SSH_MSG_PORT_OPEN);
1255: packet_put_int(c->self);
1256: packet_put_cstring(c->path);
1257: packet_put_int(c->host_port);
1.121 markus 1258: if (packet_get_protocol_flags() &
1259: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1260: packet_put_cstring(c->remote_name);
1261: packet_send();
1262: }
1263: xfree(remote_ipaddr);
1264: }
1265:
1.226 djm 1266: static void
1267: channel_set_reuseaddr(int fd)
1268: {
1269: int on = 1;
1270:
1271: /*
1272: * Set socket options.
1273: * Allow local port reuse in TIME_WAIT.
1274: */
1275: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1276: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1277: }
1278:
1.41 markus 1279: /*
1280: * This socket is listening for connections to a forwarded TCP/IP port.
1281: */
1.127 itojun 1282: static void
1.237 deraadt 1283: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1284: {
1.103 markus 1285: Channel *nc;
1.41 markus 1286: struct sockaddr addr;
1.113 markus 1287: int newsock, nextstate;
1.41 markus 1288: socklen_t addrlen;
1.103 markus 1289: char *rtype;
1.73 markus 1290:
1.41 markus 1291: if (FD_ISSET(c->sock, readset)) {
1292: debug("Connection to port %d forwarding "
1293: "to %.100s port %d requested.",
1294: c->listening_port, c->path, c->host_port);
1.103 markus 1295:
1.137 markus 1296: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1297: nextstate = SSH_CHANNEL_OPENING;
1298: rtype = "forwarded-tcpip";
1299: } else {
1300: if (c->host_port == 0) {
1301: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1302: rtype = "dynamic-tcpip";
1.137 markus 1303: } else {
1304: nextstate = SSH_CHANNEL_OPENING;
1305: rtype = "direct-tcpip";
1306: }
1307: }
1.103 markus 1308:
1.41 markus 1309: addrlen = sizeof(addr);
1310: newsock = accept(c->sock, &addr, &addrlen);
1311: if (newsock < 0) {
1312: error("accept: %.100s", strerror(errno));
1313: return;
1314: }
1.169 stevesk 1315: set_nodelay(newsock);
1.190 markus 1316: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1317: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1318: nc->listening_port = c->listening_port;
1319: nc->host_port = c->host_port;
1320: strlcpy(nc->path, c->path, sizeof(nc->path));
1321:
1.137 markus 1322: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1323: /*
1324: * do not call the channel_post handler until
1325: * this flag has been reset by a pre-handler.
1326: * otherwise the FD_ISSET calls might overflow
1327: */
1328: nc->delayed = 1;
1329: } else {
1.103 markus 1330: port_open_helper(nc, rtype);
1.137 markus 1331: }
1.41 markus 1332: }
1333: }
1.25 markus 1334:
1.41 markus 1335: /*
1336: * This is the authentication agent socket listening for connections from
1337: * clients.
1338: */
1.127 itojun 1339: static void
1.237 deraadt 1340: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1341: {
1.113 markus 1342: Channel *nc;
1343: int newsock;
1.41 markus 1344: struct sockaddr addr;
1345: socklen_t addrlen;
1.25 markus 1346:
1.41 markus 1347: if (FD_ISSET(c->sock, readset)) {
1348: addrlen = sizeof(addr);
1349: newsock = accept(c->sock, &addr, &addrlen);
1350: if (newsock < 0) {
1351: error("accept from auth socket: %.100s", strerror(errno));
1352: return;
1353: }
1.113 markus 1354: nc = channel_new("accepted auth socket",
1.73 markus 1355: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1356: c->local_window_max, c->local_maxpacket,
1.190 markus 1357: 0, "accepted auth socket", 1);
1.73 markus 1358: if (compat20) {
1359: packet_start(SSH2_MSG_CHANNEL_OPEN);
1360: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1361: packet_put_int(nc->self);
1.73 markus 1362: packet_put_int(c->local_window_max);
1363: packet_put_int(c->local_maxpacket);
1364: } else {
1365: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1366: packet_put_int(nc->self);
1.73 markus 1367: }
1.41 markus 1368: packet_send();
1369: }
1370: }
1.25 markus 1371:
1.127 itojun 1372: static void
1.237 deraadt 1373: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1374: {
1.114 markus 1375: int err = 0;
1.129 stevesk 1376: socklen_t sz = sizeof(err);
1.114 markus 1377:
1.75 markus 1378: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1379: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1380: err = errno;
1381: error("getsockopt SO_ERROR failed");
1382: }
1383: if (err == 0) {
1384: debug("channel %d: connected", c->self);
1385: c->type = SSH_CHANNEL_OPEN;
1386: if (compat20) {
1387: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1388: packet_put_int(c->remote_id);
1389: packet_put_int(c->self);
1390: packet_put_int(c->local_window);
1391: packet_put_int(c->local_maxpacket);
1392: } else {
1393: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1394: packet_put_int(c->remote_id);
1395: packet_put_int(c->self);
1396: }
1.75 markus 1397: } else {
1.114 markus 1398: debug("channel %d: not connected: %s",
1399: c->self, strerror(err));
1400: if (compat20) {
1401: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1402: packet_put_int(c->remote_id);
1403: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1404: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1405: packet_put_cstring(strerror(err));
1406: packet_put_cstring("");
1407: }
1.75 markus 1408: } else {
1.114 markus 1409: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1410: packet_put_int(c->remote_id);
1.75 markus 1411: }
1.114 markus 1412: chan_mark_dead(c);
1.75 markus 1413: }
1.114 markus 1414: packet_send();
1.75 markus 1415: }
1416: }
1417:
1.127 itojun 1418: static int
1.237 deraadt 1419: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1420: {
1.214 markus 1421: char buf[CHAN_RBUF];
1.41 markus 1422: int len;
1.25 markus 1423:
1.118 markus 1424: if (c->rfd != -1 &&
1.41 markus 1425: FD_ISSET(c->rfd, readset)) {
1426: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1427: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1428: return 1;
1.41 markus 1429: if (len <= 0) {
1.194 markus 1430: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1431: c->self, c->rfd, len);
1.104 markus 1432: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1433: debug2("channel %d: not open", c->self);
1.113 markus 1434: chan_mark_dead(c);
1.103 markus 1435: return -1;
1.104 markus 1436: } else if (compat13) {
1.158 markus 1437: buffer_clear(&c->output);
1.41 markus 1438: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1439: debug2("channel %d: input draining.", c->self);
1.25 markus 1440: } else {
1.41 markus 1441: chan_read_failed(c);
1.25 markus 1442: }
1.41 markus 1443: return -1;
1444: }
1.143 deraadt 1445: if (c->input_filter != NULL) {
1.66 markus 1446: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1447: debug2("channel %d: filter stops", c->self);
1.65 markus 1448: chan_read_failed(c);
1449: }
1.228 reyk 1450: } else if (c->datagram) {
1451: buffer_put_string(&c->input, buf, len);
1.65 markus 1452: } else {
1453: buffer_append(&c->input, buf, len);
1454: }
1.41 markus 1455: }
1456: return 1;
1457: }
1.241 deraadt 1458:
1.127 itojun 1459: static int
1.237 deraadt 1460: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1461: {
1.95 markus 1462: struct termios tio;
1.231 reyk 1463: u_char *data = NULL, *buf;
1.134 markus 1464: u_int dlen;
1.41 markus 1465: int len;
1.25 markus 1466:
1.41 markus 1467: /* Send buffered output data to the socket. */
1.118 markus 1468: if (c->wfd != -1 &&
1.41 markus 1469: FD_ISSET(c->wfd, writeset) &&
1470: buffer_len(&c->output) > 0) {
1.231 reyk 1471: if (c->output_filter != NULL) {
1472: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1473: debug2("channel %d: filter stops", c->self);
1.232 reyk 1474: if (c->type != SSH_CHANNEL_OPEN)
1475: chan_mark_dead(c);
1476: else
1477: chan_write_failed(c);
1478: return -1;
1.231 reyk 1479: }
1480: } else if (c->datagram) {
1481: buf = data = buffer_get_string(&c->output, &dlen);
1482: } else {
1483: buf = data = buffer_ptr(&c->output);
1484: dlen = buffer_len(&c->output);
1485: }
1486:
1.228 reyk 1487: if (c->datagram) {
1488: /* ignore truncated writes, datagrams might get lost */
1489: c->local_consumed += dlen + 4;
1.231 reyk 1490: len = write(c->wfd, buf, dlen);
1.228 reyk 1491: xfree(data);
1492: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1493: return 1;
1494: if (len <= 0) {
1495: if (c->type != SSH_CHANNEL_OPEN)
1496: chan_mark_dead(c);
1497: else
1498: chan_write_failed(c);
1499: return -1;
1500: }
1501: return 1;
1502: }
1.231 reyk 1503:
1504: len = write(c->wfd, buf, dlen);
1.53 markus 1505: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1506: return 1;
1.41 markus 1507: if (len <= 0) {
1.104 markus 1508: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1509: debug2("channel %d: not open", c->self);
1.113 markus 1510: chan_mark_dead(c);
1.104 markus 1511: return -1;
1512: } else if (compat13) {
1.158 markus 1513: buffer_clear(&c->output);
1.194 markus 1514: debug2("channel %d: input draining.", c->self);
1.41 markus 1515: c->type = SSH_CHANNEL_INPUT_DRAINING;
1516: } else {
1517: chan_write_failed(c);
1518: }
1519: return -1;
1.91 markus 1520: }
1.231 reyk 1521: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1522: if (tcgetattr(c->wfd, &tio) == 0 &&
1523: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1524: /*
1525: * Simulate echo to reduce the impact of
1.96 markus 1526: * traffic analysis. We need to match the
1.95 markus 1527: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1528: * (4 byte channel id + buf)
1.91 markus 1529: */
1.95 markus 1530: packet_send_ignore(4 + len);
1.91 markus 1531: packet_send();
1532: }
1.25 markus 1533: }
1.41 markus 1534: buffer_consume(&c->output, len);
1.44 markus 1535: if (compat20 && len > 0) {
1536: c->local_consumed += len;
1537: }
1538: }
1539: return 1;
1540: }
1.241 deraadt 1541:
1.127 itojun 1542: static int
1.237 deraadt 1543: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1544: {
1.214 markus 1545: char buf[CHAN_RBUF];
1.44 markus 1546: int len;
1547:
1.45 markus 1548: /** XXX handle drain efd, too */
1.44 markus 1549: if (c->efd != -1) {
1550: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1551: FD_ISSET(c->efd, writeset) &&
1552: buffer_len(&c->extended) > 0) {
1553: len = write(c->efd, buffer_ptr(&c->extended),
1554: buffer_len(&c->extended));
1.70 markus 1555: debug2("channel %d: written %d to efd %d",
1.44 markus 1556: c->self, len, c->efd);
1.93 markus 1557: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1558: return 1;
1559: if (len <= 0) {
1560: debug2("channel %d: closing write-efd %d",
1561: c->self, c->efd);
1.132 markus 1562: channel_close_fd(&c->efd);
1.93 markus 1563: } else {
1.44 markus 1564: buffer_consume(&c->extended, len);
1565: c->local_consumed += len;
1566: }
1567: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1568: FD_ISSET(c->efd, readset)) {
1569: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1570: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1571: c->self, len, c->efd);
1.93 markus 1572: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1573: return 1;
1574: if (len <= 0) {
1575: debug2("channel %d: closing read-efd %d",
1.45 markus 1576: c->self, c->efd);
1.132 markus 1577: channel_close_fd(&c->efd);
1.93 markus 1578: } else {
1.44 markus 1579: buffer_append(&c->extended, buf, len);
1.93 markus 1580: }
1.44 markus 1581: }
1582: }
1583: return 1;
1584: }
1.241 deraadt 1585:
1.127 itojun 1586: static int
1.237 deraadt 1587: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1588: {
1589: char buf[16];
1590: int len;
1591:
1592: /* Monitor control fd to detect if the slave client exits */
1593: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1594: len = read(c->ctl_fd, buf, sizeof(buf));
1595: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1596: return 1;
1597: if (len <= 0) {
1598: debug2("channel %d: ctl read<=0", c->self);
1599: if (c->type != SSH_CHANNEL_OPEN) {
1600: debug2("channel %d: not open", c->self);
1601: chan_mark_dead(c);
1602: return -1;
1603: } else {
1604: chan_read_failed(c);
1605: chan_write_failed(c);
1606: }
1607: return -1;
1608: } else
1609: fatal("%s: unexpected data on ctl fd", __func__);
1610: }
1611: return 1;
1612: }
1.241 deraadt 1613:
1.204 djm 1614: static int
1.93 markus 1615: channel_check_window(Channel *c)
1.44 markus 1616: {
1.104 markus 1617: if (c->type == SSH_CHANNEL_OPEN &&
1618: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1619: c->local_window < c->local_window_max/2 &&
1620: c->local_consumed > 0) {
1621: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1622: packet_put_int(c->remote_id);
1623: packet_put_int(c->local_consumed);
1624: packet_send();
1.70 markus 1625: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1626: c->self, c->local_window,
1627: c->local_consumed);
1628: c->local_window += c->local_consumed;
1629: c->local_consumed = 0;
1.1 deraadt 1630: }
1.41 markus 1631: return 1;
1.1 deraadt 1632: }
1633:
1.127 itojun 1634: static void
1.237 deraadt 1635: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1636: {
1.137 markus 1637: if (c->delayed)
1638: return;
1.41 markus 1639: channel_handle_rfd(c, readset, writeset);
1640: channel_handle_wfd(c, readset, writeset);
1.157 markus 1641: if (!compat20)
1.137 markus 1642: return;
1.44 markus 1643: channel_handle_efd(c, readset, writeset);
1.204 djm 1644: channel_handle_ctl(c, readset, writeset);
1.93 markus 1645: channel_check_window(c);
1.44 markus 1646: }
1647:
1.127 itojun 1648: static void
1.237 deraadt 1649: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1650: {
1.41 markus 1651: int len;
1.180 deraadt 1652:
1.41 markus 1653: /* Send buffered output data to the socket. */
1654: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1655: len = write(c->sock, buffer_ptr(&c->output),
1656: buffer_len(&c->output));
1657: if (len <= 0)
1.158 markus 1658: buffer_clear(&c->output);
1.41 markus 1659: else
1660: buffer_consume(&c->output, len);
1661: }
1662: }
1.25 markus 1663:
1.127 itojun 1664: static void
1.44 markus 1665: channel_handler_init_20(void)
1666: {
1.157 markus 1667: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1668: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1669: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1670: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1671: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1672: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1673: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1674: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1675:
1.157 markus 1676: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1677: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1678: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1679: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1680: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1681: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1682: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1683: }
1684:
1.127 itojun 1685: static void
1.41 markus 1686: channel_handler_init_13(void)
1687: {
1688: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1689: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1690: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1691: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1692: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1693: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1694: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1695: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1696: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1697:
1.157 markus 1698: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1699: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1700: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1701: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1702: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1703: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1704: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1705: }
1.25 markus 1706:
1.127 itojun 1707: static void
1.41 markus 1708: channel_handler_init_15(void)
1709: {
1.157 markus 1710: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1711: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1712: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1713: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1714: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1715: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1716: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1717:
1.41 markus 1718: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1719: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1720: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1721: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1722: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1723: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1724: }
1.27 markus 1725:
1.127 itojun 1726: static void
1.41 markus 1727: channel_handler_init(void)
1728: {
1729: int i;
1.180 deraadt 1730:
1.148 deraadt 1731: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1732: channel_pre[i] = NULL;
1733: channel_post[i] = NULL;
1734: }
1.44 markus 1735: if (compat20)
1736: channel_handler_init_20();
1737: else if (compat13)
1.41 markus 1738: channel_handler_init_13();
1739: else
1740: channel_handler_init_15();
1741: }
1.25 markus 1742:
1.140 markus 1743: /* gc dead channels */
1744: static void
1745: channel_garbage_collect(Channel *c)
1746: {
1747: if (c == NULL)
1748: return;
1749: if (c->detach_user != NULL) {
1.225 djm 1750: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1751: return;
1.194 markus 1752: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1753: c->detach_user(c->self, NULL);
1754: /* if we still have a callback */
1755: if (c->detach_user != NULL)
1756: return;
1.194 markus 1757: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1758: }
1759: if (!chan_is_dead(c, 1))
1760: return;
1.194 markus 1761: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1762: channel_free(c);
1763: }
1764:
1.127 itojun 1765: static void
1.237 deraadt 1766: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1767: {
1768: static int did_init = 0;
1.209 avsm 1769: u_int i;
1.41 markus 1770: Channel *c;
1.25 markus 1771:
1.41 markus 1772: if (!did_init) {
1773: channel_handler_init();
1774: did_init = 1;
1775: }
1776: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1777: c = channels[i];
1778: if (c == NULL)
1.41 markus 1779: continue;
1.118 markus 1780: if (ftab[c->type] != NULL)
1781: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1782: channel_garbage_collect(c);
1.1 deraadt 1783: }
1784: }
1785:
1.121 markus 1786: /*
1787: * Allocate/update select bitmasks and add any bits relevant to channels in
1788: * select bitmasks.
1789: */
1.49 markus 1790: void
1.100 markus 1791: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1792: u_int *nallocp, int rekeying)
1.41 markus 1793: {
1.243 djm 1794: u_int n, sz, nfdset;
1.84 markus 1795:
1796: n = MAX(*maxfdp, channel_max_fd);
1797:
1.243 djm 1798: nfdset = howmany(n+1, NFDBITS);
1799: /* Explicitly test here, because xrealloc isn't always called */
1800: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1801: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1802: sz = nfdset * sizeof(fd_mask);
1803:
1.132 markus 1804: /* perhaps check sz < nalloc/2 and shrink? */
1805: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1806: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1807: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1808: *nallocp = sz;
1.84 markus 1809: }
1.132 markus 1810: *maxfdp = n;
1.84 markus 1811: memset(*readsetp, 0, sz);
1812: memset(*writesetp, 0, sz);
1813:
1.100 markus 1814: if (!rekeying)
1815: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1816: }
1817:
1.121 markus 1818: /*
1819: * After select, perform any appropriate operations for channels which have
1820: * events pending.
1821: */
1.49 markus 1822: void
1.237 deraadt 1823: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1824: {
1825: channel_handler(channel_post, readset, writeset);
1826: }
1827:
1.121 markus 1828:
1.84 markus 1829: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1830: void
1.142 itojun 1831: channel_output_poll(void)
1.1 deraadt 1832: {
1.41 markus 1833: Channel *c;
1.209 avsm 1834: u_int i, len;
1.1 deraadt 1835:
1.25 markus 1836: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1837: c = channels[i];
1838: if (c == NULL)
1839: continue;
1.37 markus 1840:
1.121 markus 1841: /*
1842: * We are only interested in channels that can have buffered
1843: * incoming data.
1844: */
1.37 markus 1845: if (compat13) {
1.41 markus 1846: if (c->type != SSH_CHANNEL_OPEN &&
1847: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1848: continue;
1849: } else {
1.41 markus 1850: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1851: continue;
1852: }
1.46 markus 1853: if (compat20 &&
1854: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1855: /* XXX is this true? */
1.140 markus 1856: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1857: continue;
1858: }
1.25 markus 1859:
1860: /* Get the amount of buffered data for this channel. */
1.93 markus 1861: if ((c->istate == CHAN_INPUT_OPEN ||
1862: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1863: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1864: if (c->datagram) {
1865: if (len > 0) {
1866: u_char *data;
1867: u_int dlen;
1868:
1869: data = buffer_get_string(&c->input,
1870: &dlen);
1871: packet_start(SSH2_MSG_CHANNEL_DATA);
1872: packet_put_int(c->remote_id);
1873: packet_put_string(data, dlen);
1874: packet_send();
1875: c->remote_window -= dlen + 4;
1876: xfree(data);
1877: }
1878: continue;
1879: }
1.121 markus 1880: /*
1881: * Send some data for the other side over the secure
1882: * connection.
1883: */
1.44 markus 1884: if (compat20) {
1885: if (len > c->remote_window)
1886: len = c->remote_window;
1887: if (len > c->remote_maxpacket)
1888: len = c->remote_maxpacket;
1.25 markus 1889: } else {
1.44 markus 1890: if (packet_is_interactive()) {
1891: if (len > 1024)
1892: len = 512;
1893: } else {
1894: /* Keep the packets at reasonable size. */
1895: if (len > packet_get_maxsize()/2)
1896: len = packet_get_maxsize()/2;
1897: }
1.25 markus 1898: }
1.41 markus 1899: if (len > 0) {
1.44 markus 1900: packet_start(compat20 ?
1901: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1902: packet_put_int(c->remote_id);
1903: packet_put_string(buffer_ptr(&c->input), len);
1904: packet_send();
1905: buffer_consume(&c->input, len);
1906: c->remote_window -= len;
1907: }
1908: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1909: if (compat13)
1910: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1911: /*
1912: * input-buffer is empty and read-socket shutdown:
1.172 markus 1913: * tell peer, that we will not send more data: send IEOF.
1914: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1915: */
1.172 markus 1916: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1917: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1918: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1919: else
1920: chan_ibuf_empty(c);
1.25 markus 1921: }
1.44 markus 1922: /* Send extended data, i.e. stderr */
1923: if (compat20 &&
1.172 markus 1924: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1925: c->remote_window > 0 &&
1926: (len = buffer_len(&c->extended)) > 0 &&
1927: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1928: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1929: c->self, c->remote_window, buffer_len(&c->extended),
1930: c->extended_usage);
1.44 markus 1931: if (len > c->remote_window)
1932: len = c->remote_window;
1933: if (len > c->remote_maxpacket)
1934: len = c->remote_maxpacket;
1935: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1936: packet_put_int(c->remote_id);
1937: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1938: packet_put_string(buffer_ptr(&c->extended), len);
1939: packet_send();
1940: buffer_consume(&c->extended, len);
1941: c->remote_window -= len;
1.93 markus 1942: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1943: }
1.25 markus 1944: }
1.1 deraadt 1945: }
1946:
1.121 markus 1947:
1948: /* -- protocol input */
1.249 djm 1949:
1950: /* ARGSUSED */
1.49 markus 1951: void
1.154 markus 1952: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1953: {
1.37 markus 1954: int id;
1.25 markus 1955: char *data;
1.77 markus 1956: u_int data_len;
1.41 markus 1957: Channel *c;
1.25 markus 1958:
1959: /* Get the channel number and verify it. */
1.37 markus 1960: id = packet_get_int();
1.41 markus 1961: c = channel_lookup(id);
1962: if (c == NULL)
1.37 markus 1963: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1964:
1965: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1966: if (c->type != SSH_CHANNEL_OPEN &&
1967: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1968: return;
1969:
1.25 markus 1970: /* Get the data. */
1971: data = packet_get_string(&data_len);
1.200 markus 1972:
1973: /*
1974: * Ignore data for protocol > 1.3 if output end is no longer open.
1975: * For protocol 2 the sending side is reducing its window as it sends
1976: * data, so we must 'fake' consumption of the data in order to ensure
1977: * that window updates are sent back. Otherwise the connection might
1978: * deadlock.
1979: */
1980: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1981: if (compat20) {
1982: c->local_window -= data_len;
1983: c->local_consumed += data_len;
1984: }
1985: xfree(data);
1986: return;
1987: }
1.41 markus 1988:
1.143 deraadt 1989: if (compat20) {
1.44 markus 1990: if (data_len > c->local_maxpacket) {
1.188 itojun 1991: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1992: c->self, data_len, c->local_maxpacket);
1993: }
1994: if (data_len > c->local_window) {
1.188 itojun 1995: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1996: c->self, data_len, c->local_window);
1997: xfree(data);
1998: return;
1999: }
2000: c->local_window -= data_len;
2001: }
1.152 markus 2002: packet_check_eom();
1.228 reyk 2003: if (c->datagram)
2004: buffer_put_string(&c->output, data, data_len);
2005: else
2006: buffer_append(&c->output, data, data_len);
1.25 markus 2007: xfree(data);
1.1 deraadt 2008: }
1.121 markus 2009:
1.249 djm 2010: /* ARGSUSED */
1.49 markus 2011: void
1.154 markus 2012: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2013: {
2014: int id;
2015: char *data;
1.177 markus 2016: u_int data_len, tcode;
1.44 markus 2017: Channel *c;
2018:
2019: /* Get the channel number and verify it. */
2020: id = packet_get_int();
2021: c = channel_lookup(id);
2022:
2023: if (c == NULL)
2024: packet_disconnect("Received extended_data for bad channel %d.", id);
2025: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2026: logit("channel %d: ext data for non open", id);
1.44 markus 2027: return;
1.172 markus 2028: }
2029: if (c->flags & CHAN_EOF_RCVD) {
2030: if (datafellows & SSH_BUG_EXTEOF)
2031: debug("channel %d: accepting ext data after eof", id);
2032: else
2033: packet_disconnect("Received extended_data after EOF "
2034: "on channel %d.", id);
1.44 markus 2035: }
2036: tcode = packet_get_int();
2037: if (c->efd == -1 ||
2038: c->extended_usage != CHAN_EXTENDED_WRITE ||
2039: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2040: logit("channel %d: bad ext data", c->self);
1.44 markus 2041: return;
2042: }
2043: data = packet_get_string(&data_len);
1.152 markus 2044: packet_check_eom();
1.44 markus 2045: if (data_len > c->local_window) {
1.188 itojun 2046: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2047: c->self, data_len, c->local_window);
2048: xfree(data);
2049: return;
2050: }
1.70 markus 2051: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2052: c->local_window -= data_len;
2053: buffer_append(&c->extended, data, data_len);
2054: xfree(data);
2055: }
2056:
1.249 djm 2057: /* ARGSUSED */
1.49 markus 2058: void
1.154 markus 2059: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2060: {
2061: int id;
2062: Channel *c;
2063:
2064: id = packet_get_int();
1.152 markus 2065: packet_check_eom();
1.41 markus 2066: c = channel_lookup(id);
2067: if (c == NULL)
2068: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2069: chan_rcvd_ieof(c);
1.133 markus 2070:
2071: /* XXX force input close */
1.156 markus 2072: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2073: debug("channel %d: FORCE input drain", c->self);
2074: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2075: if (buffer_len(&c->input) == 0)
2076: chan_ibuf_empty(c);
1.133 markus 2077: }
2078:
1.41 markus 2079: }
1.1 deraadt 2080:
1.249 djm 2081: /* ARGSUSED */
1.49 markus 2082: void
1.154 markus 2083: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2084: {
1.41 markus 2085: int id;
2086: Channel *c;
1.1 deraadt 2087:
1.41 markus 2088: id = packet_get_int();
1.152 markus 2089: packet_check_eom();
1.41 markus 2090: c = channel_lookup(id);
2091: if (c == NULL)
2092: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2093:
2094: /*
2095: * Send a confirmation that we have closed the channel and no more
2096: * data is coming for it.
2097: */
1.25 markus 2098: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2099: packet_put_int(c->remote_id);
1.25 markus 2100: packet_send();
2101:
1.27 markus 2102: /*
2103: * If the channel is in closed state, we have sent a close request,
2104: * and the other side will eventually respond with a confirmation.
2105: * Thus, we cannot free the channel here, because then there would be
2106: * no-one to receive the confirmation. The channel gets freed when
2107: * the confirmation arrives.
2108: */
1.41 markus 2109: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2110: /*
2111: * Not a closed channel - mark it as draining, which will
2112: * cause it to be freed later.
2113: */
1.158 markus 2114: buffer_clear(&c->input);
1.41 markus 2115: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2116: }
1.1 deraadt 2117: }
2118:
1.41 markus 2119: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2120: /* ARGSUSED */
1.49 markus 2121: void
1.154 markus 2122: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2123: {
2124: int id = packet_get_int();
2125: Channel *c = channel_lookup(id);
1.151 markus 2126:
1.152 markus 2127: packet_check_eom();
1.41 markus 2128: if (c == NULL)
2129: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2130: chan_rcvd_oclose(c);
2131: }
1.1 deraadt 2132:
1.249 djm 2133: /* ARGSUSED */
1.49 markus 2134: void
1.154 markus 2135: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2136: {
1.41 markus 2137: int id = packet_get_int();
2138: Channel *c = channel_lookup(id);
1.1 deraadt 2139:
1.152 markus 2140: packet_check_eom();
1.41 markus 2141: if (c == NULL)
2142: packet_disconnect("Received close confirmation for "
2143: "out-of-range channel %d.", id);
2144: if (c->type != SSH_CHANNEL_CLOSED)
2145: packet_disconnect("Received close confirmation for "
2146: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2147: channel_free(c);
1.1 deraadt 2148: }
2149:
1.249 djm 2150: /* ARGSUSED */
1.49 markus 2151: void
1.154 markus 2152: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2153: {
1.41 markus 2154: int id, remote_id;
2155: Channel *c;
1.1 deraadt 2156:
1.41 markus 2157: id = packet_get_int();
2158: c = channel_lookup(id);
1.25 markus 2159:
1.41 markus 2160: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2161: packet_disconnect("Received open confirmation for "
2162: "non-opening channel %d.", id);
2163: remote_id = packet_get_int();
1.27 markus 2164: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2165: c->remote_id = remote_id;
2166: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2167:
2168: if (compat20) {
2169: c->remote_window = packet_get_int();
2170: c->remote_maxpacket = packet_get_int();
1.165 markus 2171: if (c->confirm) {
1.70 markus 2172: debug2("callback start");
1.204 djm 2173: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2174: debug2("callback done");
1.44 markus 2175: }
1.194 markus 2176: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2177: c->remote_window, c->remote_maxpacket);
2178: }
1.152 markus 2179: packet_check_eom();
1.1 deraadt 2180: }
2181:
1.127 itojun 2182: static char *
1.114 markus 2183: reason2txt(int reason)
2184: {
1.143 deraadt 2185: switch (reason) {
1.114 markus 2186: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2187: return "administratively prohibited";
2188: case SSH2_OPEN_CONNECT_FAILED:
2189: return "connect failed";
2190: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2191: return "unknown channel type";
2192: case SSH2_OPEN_RESOURCE_SHORTAGE:
2193: return "resource shortage";
2194: }
1.117 stevesk 2195: return "unknown reason";
1.114 markus 2196: }
2197:
1.249 djm 2198: /* ARGSUSED */
1.49 markus 2199: void
1.154 markus 2200: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2201: {
1.86 markus 2202: int id, reason;
2203: char *msg = NULL, *lang = NULL;
1.41 markus 2204: Channel *c;
2205:
2206: id = packet_get_int();
2207: c = channel_lookup(id);
1.25 markus 2208:
1.41 markus 2209: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2210: packet_disconnect("Received open failure for "
2211: "non-opening channel %d.", id);
1.44 markus 2212: if (compat20) {
1.86 markus 2213: reason = packet_get_int();
1.110 markus 2214: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2215: msg = packet_get_string(NULL);
2216: lang = packet_get_string(NULL);
2217: }
1.188 itojun 2218: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2219: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2220: if (msg != NULL)
2221: xfree(msg);
2222: if (lang != NULL)
2223: xfree(lang);
1.44 markus 2224: }
1.152 markus 2225: packet_check_eom();
1.25 markus 2226: /* Free the channel. This will also close the socket. */
1.113 markus 2227: channel_free(c);
1.44 markus 2228: }
2229:
1.249 djm 2230: /* ARGSUSED */
1.121 markus 2231: void
1.154 markus 2232: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2233: {
2234: Channel *c;
1.178 markus 2235: int id;
2236: u_int adjust;
1.121 markus 2237:
2238: if (!compat20)
2239: return;
2240:
2241: /* Get the channel number and verify it. */
2242: id = packet_get_int();
2243: c = channel_lookup(id);
1.1 deraadt 2244:
1.229 markus 2245: if (c == NULL) {
2246: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2247: return;
2248: }
2249: adjust = packet_get_int();
1.152 markus 2250: packet_check_eom();
1.178 markus 2251: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2252: c->remote_window += adjust;
2253: }
1.1 deraadt 2254:
1.249 djm 2255: /* ARGSUSED */
1.121 markus 2256: void
1.154 markus 2257: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2258: {
1.121 markus 2259: Channel *c = NULL;
2260: u_short host_port;
2261: char *host, *originator_string;
2262: int remote_id, sock = -1;
2263:
2264: remote_id = packet_get_int();
2265: host = packet_get_string(NULL);
2266: host_port = packet_get_int();
1.25 markus 2267:
1.121 markus 2268: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2269: originator_string = packet_get_string(NULL);
2270: } else {
2271: originator_string = xstrdup("unknown (remote did not supply name)");
2272: }
1.152 markus 2273: packet_check_eom();
1.121 markus 2274: sock = channel_connect_to(host, host_port);
2275: if (sock != -1) {
2276: c = channel_new("connected socket",
2277: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2278: originator_string, 1);
1.167 markus 2279: c->remote_id = remote_id;
1.25 markus 2280: }
1.190 markus 2281: xfree(originator_string);
1.121 markus 2282: if (c == NULL) {
2283: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2284: packet_put_int(remote_id);
2285: packet_send();
2286: }
2287: xfree(host);
1.1 deraadt 2288: }
2289:
1.121 markus 2290:
2291: /* -- tcp forwarding */
1.135 markus 2292:
2293: void
2294: channel_set_af(int af)
2295: {
2296: IPv4or6 = af;
2297: }
1.121 markus 2298:
1.160 markus 2299: static int
2300: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2301: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2302: {
1.113 markus 2303: Channel *c;
1.226 djm 2304: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2305: struct addrinfo hints, *ai, *aitop;
1.212 djm 2306: const char *host, *addr;
1.35 markus 2307: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2308:
1.160 markus 2309: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2310: listen_addr : host_to_connect;
1.212 djm 2311: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2312:
1.160 markus 2313: if (host == NULL) {
2314: error("No forward host name.");
1.218 markus 2315: return 0;
1.73 markus 2316: }
1.113 markus 2317: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2318: error("Forward host name too long.");
1.218 markus 2319: return 0;
1.87 markus 2320: }
1.25 markus 2321:
1.28 markus 2322: /*
1.212 djm 2323: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2324: * specified address or wildcard. On the client, a specified bind
2325: * address will always override gateway_ports. On the server, a
2326: * gateway_ports of 1 (``yes'') will override the client's
2327: * specification and force a wildcard bind, whereas a value of 2
2328: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2329: * asked for.
2330: *
2331: * Special-case listen_addrs are:
2332: *
2333: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2334: * "" (empty string), "*" -> wildcard v4/v6
2335: * "localhost" -> loopback v4/v6
2336: */
2337: addr = NULL;
2338: if (listen_addr == NULL) {
2339: /* No address specified: default to gateway_ports setting */
2340: if (gateway_ports)
2341: wildcard = 1;
2342: } else if (gateway_ports || is_client) {
2343: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2344: strcmp(listen_addr, "0.0.0.0") == 0) ||
2345: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2346: (!is_client && gateway_ports == 1))
2347: wildcard = 1;
2348: else if (strcmp(listen_addr, "localhost") != 0)
2349: addr = listen_addr;
2350: }
2351:
2352: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2353: type, wildcard, (addr == NULL) ? "NULL" : addr);
2354:
2355: /*
1.35 markus 2356: * getaddrinfo returns a loopback address if the hostname is
2357: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2358: */
1.35 markus 2359: memset(&hints, 0, sizeof(hints));
2360: hints.ai_family = IPv4or6;
1.212 djm 2361: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2362: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2363: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2364: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2365: if (addr == NULL) {
2366: /* This really shouldn't happen */
2367: packet_disconnect("getaddrinfo: fatal error: %s",
2368: gai_strerror(r));
2369: } else {
1.218 markus 2370: error("channel_setup_fwd_listener: "
1.212 djm 2371: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2372: }
1.218 markus 2373: return 0;
1.212 djm 2374: }
1.35 markus 2375:
2376: for (ai = aitop; ai; ai = ai->ai_next) {
2377: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2378: continue;
2379: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2380: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2381: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2382: continue;
2383: }
2384: /* Create a port to listen for the host. */
1.189 markus 2385: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2386: if (sock < 0) {
2387: /* this is no error since kernel may not support ipv6 */
2388: verbose("socket: %.100s", strerror(errno));
2389: continue;
2390: }
1.226 djm 2391:
2392: channel_set_reuseaddr(sock);
1.182 stevesk 2393:
1.35 markus 2394: debug("Local forwarding listening on %s port %s.", ntop, strport);
2395:
2396: /* Bind the socket to the address. */
2397: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2398: /* address can be in use ipv6 address is already bound */
2399: verbose("bind: %.100s", strerror(errno));
2400: close(sock);
2401: continue;
2402: }
2403: /* Start listening for connections on the socket. */
1.199 markus 2404: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2405: error("listen: %.100s", strerror(errno));
2406: close(sock);
2407: continue;
2408: }
2409: /* Allocate a channel number for the socket. */
1.121 markus 2410: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2411: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2412: 0, "port listener", 1);
1.113 markus 2413: strlcpy(c->path, host, sizeof(c->path));
2414: c->host_port = port_to_connect;
2415: c->listening_port = listen_port;
1.35 markus 2416: success = 1;
2417: }
2418: if (success == 0)
1.160 markus 2419: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2420: listen_port);
1.35 markus 2421: freeaddrinfo(aitop);
1.87 markus 2422: return success;
1.25 markus 2423: }
1.1 deraadt 2424:
1.202 djm 2425: int
2426: channel_cancel_rport_listener(const char *host, u_short port)
2427: {
1.209 avsm 2428: u_int i;
2429: int found = 0;
1.202 djm 2430:
1.213 deraadt 2431: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2432: Channel *c = channels[i];
2433:
2434: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2435: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2436: c->listening_port == port) {
1.210 djm 2437: debug2("%s: close channel %d", __func__, i);
1.202 djm 2438: channel_free(c);
2439: found = 1;
2440: }
2441: }
2442:
2443: return (found);
2444: }
2445:
1.160 markus 2446: /* protocol local port fwd, used by ssh (and sshd in v1) */
2447: int
1.212 djm 2448: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2449: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2450: {
2451: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2452: listen_host, listen_port, host_to_connect, port_to_connect,
2453: gateway_ports);
1.160 markus 2454: }
2455:
2456: /* protocol v2 remote port fwd, used by sshd */
2457: int
2458: channel_setup_remote_fwd_listener(const char *listen_address,
2459: u_short listen_port, int gateway_ports)
2460: {
2461: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2462: listen_address, listen_port, NULL, 0, gateway_ports);
2463: }
2464:
1.27 markus 2465: /*
2466: * Initiate forwarding of connections to port "port" on remote host through
2467: * the secure channel to host:port from local side.
2468: */
1.1 deraadt 2469:
1.253 markus 2470: int
1.212 djm 2471: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2472: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2473: {
1.153 markus 2474: int type, success = 0;
1.73 markus 2475:
1.25 markus 2476: /* Record locally that connection to this host/port is permitted. */
2477: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2478: fatal("channel_request_remote_forwarding: too many forwards");
2479:
2480: /* Send the forward request to the remote side. */
1.44 markus 2481: if (compat20) {
1.212 djm 2482: const char *address_to_bind;
2483: if (listen_host == NULL)
2484: address_to_bind = "localhost";
2485: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2486: address_to_bind = "";
2487: else
2488: address_to_bind = listen_host;
2489:
1.44 markus 2490: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2491: packet_put_cstring("tcpip-forward");
1.173 markus 2492: packet_put_char(1); /* boolean: want reply */
1.44 markus 2493: packet_put_cstring(address_to_bind);
2494: packet_put_int(listen_port);
1.73 markus 2495: packet_send();
2496: packet_write_wait();
2497: /* Assume that server accepts the request */
2498: success = 1;
1.44 markus 2499: } else {
2500: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2501: packet_put_int(listen_port);
2502: packet_put_cstring(host_to_connect);
1.44 markus 2503: packet_put_int(port_to_connect);
2504: packet_send();
2505: packet_write_wait();
1.73 markus 2506:
2507: /* Wait for response from the remote side. */
1.153 markus 2508: type = packet_read();
1.73 markus 2509: switch (type) {
2510: case SSH_SMSG_SUCCESS:
2511: success = 1;
2512: break;
2513: case SSH_SMSG_FAILURE:
2514: break;
2515: default:
2516: /* Unknown packet */
2517: packet_disconnect("Protocol error for port forward request:"
2518: "received packet type %d.", type);
2519: }
2520: }
2521: if (success) {
2522: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2523: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2524: permitted_opens[num_permitted_opens].listen_port = listen_port;
2525: num_permitted_opens++;
1.44 markus 2526: }
1.253 markus 2527: return (success ? 0 : -1);
1.1 deraadt 2528: }
2529:
1.27 markus 2530: /*
1.208 deraadt 2531: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2532: * local side.
2533: */
2534: void
1.212 djm 2535: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2536: {
2537: int i;
2538:
2539: if (!compat20)
2540: return;
2541:
2542: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2543: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2544: permitted_opens[i].listen_port == port)
2545: break;
2546: }
2547: if (i >= num_permitted_opens) {
2548: debug("%s: requested forward not found", __func__);
2549: return;
2550: }
2551: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2552: packet_put_cstring("cancel-tcpip-forward");
2553: packet_put_char(0);
1.212 djm 2554: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2555: packet_put_int(port);
2556: packet_send();
2557:
2558: permitted_opens[i].listen_port = 0;
2559: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2560: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2561: permitted_opens[i].host_to_connect = NULL;
2562: }
2563:
2564: /*
1.27 markus 2565: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2566: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2567: * message if there was an error).
1.27 markus 2568: */
1.253 markus 2569: int
1.56 markus 2570: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2571: {
1.31 markus 2572: u_short port, host_port;
1.253 markus 2573: int success = 0;
1.25 markus 2574: char *hostname;
1.1 deraadt 2575:
1.25 markus 2576: /* Get arguments from the packet. */
2577: port = packet_get_int();
2578: hostname = packet_get_string(NULL);
2579: host_port = packet_get_int();
2580:
1.27 markus 2581: /*
2582: * Check that an unprivileged user is not trying to forward a
2583: * privileged port.
2584: */
1.25 markus 2585: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2586: packet_disconnect(
2587: "Requested forwarding of port %d but user is not root.",
2588: port);
2589: if (host_port == 0)
2590: packet_disconnect("Dynamic forwarding denied.");
2591:
1.73 markus 2592: /* Initiate forwarding */
1.253 markus 2593: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2594: host_port, gateway_ports);
1.25 markus 2595:
2596: /* Free the argument string. */
2597: xfree(hostname);
1.253 markus 2598:
2599: return (success ? 0 : -1);
1.1 deraadt 2600: }
2601:
1.99 markus 2602: /*
2603: * Permits opening to any host/port if permitted_opens[] is empty. This is
2604: * usually called by the server, because the user could connect to any port
2605: * anyway, and the server has no way to know but to trust the client anyway.
2606: */
2607: void
1.142 itojun 2608: channel_permit_all_opens(void)
1.99 markus 2609: {
2610: if (num_permitted_opens == 0)
2611: all_opens_permitted = 1;
2612: }
2613:
1.101 markus 2614: void
1.99 markus 2615: channel_add_permitted_opens(char *host, int port)
2616: {
2617: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1.253 markus 2618: fatal("channel_add_permitted_opens: too many forwards");
1.99 markus 2619: debug("allow port forwarding to host %s port %d", host, port);
2620:
2621: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2622: permitted_opens[num_permitted_opens].port_to_connect = port;
2623: num_permitted_opens++;
2624:
2625: all_opens_permitted = 0;
2626: }
2627:
1.101 markus 2628: void
1.99 markus 2629: channel_clear_permitted_opens(void)
2630: {
2631: int i;
2632:
2633: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2634: if (permitted_opens[i].host_to_connect != NULL)
2635: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2636: num_permitted_opens = 0;
2637:
2638: }
2639:
2640: /* return socket to remote host, port */
1.127 itojun 2641: static int
1.99 markus 2642: connect_to(const char *host, u_short port)
1.41 markus 2643: {
2644: struct addrinfo hints, *ai, *aitop;
2645: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2646: int gaierr;
2647: int sock = -1;
2648:
2649: memset(&hints, 0, sizeof(hints));
2650: hints.ai_family = IPv4or6;
2651: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2652: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2653: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2654: error("connect_to %.100s: unknown host (%s)", host,
2655: gai_strerror(gaierr));
1.41 markus 2656: return -1;
2657: }
2658: for (ai = aitop; ai; ai = ai->ai_next) {
2659: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2660: continue;
2661: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2662: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2663: error("connect_to: getnameinfo failed");
1.41 markus 2664: continue;
2665: }
1.189 markus 2666: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2667: if (sock < 0) {
1.186 djm 2668: if (ai->ai_next == NULL)
2669: error("socket: %.100s", strerror(errno));
2670: else
2671: verbose("socket: %.100s", strerror(errno));
1.41 markus 2672: continue;
2673: }
1.205 djm 2674: if (set_nonblock(sock) == -1)
2675: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2676: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2677: errno != EINPROGRESS) {
1.99 markus 2678: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2679: strerror(errno));
2680: close(sock);
1.89 stevesk 2681: continue; /* fail -- try next */
1.41 markus 2682: }
2683: break; /* success */
2684:
2685: }
2686: freeaddrinfo(aitop);
2687: if (!ai) {
1.99 markus 2688: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2689: return -1;
2690: }
2691: /* success */
1.169 stevesk 2692: set_nodelay(sock);
1.41 markus 2693: return sock;
2694: }
1.99 markus 2695:
1.73 markus 2696: int
1.130 stevesk 2697: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2698: {
2699: int i;
1.99 markus 2700:
1.73 markus 2701: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2702: if (permitted_opens[i].host_to_connect != NULL &&
2703: permitted_opens[i].listen_port == listen_port)
1.99 markus 2704: return connect_to(
1.73 markus 2705: permitted_opens[i].host_to_connect,
2706: permitted_opens[i].port_to_connect);
1.74 markus 2707: error("WARNING: Server requests forwarding for unknown listen_port %d",
2708: listen_port);
1.73 markus 2709: return -1;
2710: }
2711:
1.99 markus 2712: /* Check if connecting to that port is permitted and connect. */
2713: int
2714: channel_connect_to(const char *host, u_short port)
2715: {
2716: int i, permit;
2717:
2718: permit = all_opens_permitted;
2719: if (!permit) {
2720: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2721: if (permitted_opens[i].host_to_connect != NULL &&
2722: permitted_opens[i].port_to_connect == port &&
1.99 markus 2723: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2724: permit = 1;
2725:
2726: }
2727: if (!permit) {
1.188 itojun 2728: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2729: "but the request was denied.", host, port);
2730: return -1;
2731: }
2732: return connect_to(host, port);
1.204 djm 2733: }
2734:
2735: void
2736: channel_send_window_changes(void)
2737: {
1.209 avsm 2738: u_int i;
1.204 djm 2739: struct winsize ws;
2740:
2741: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2742: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2743: channels[i]->type != SSH_CHANNEL_OPEN)
2744: continue;
2745: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2746: continue;
2747: channel_request_start(i, "window-change", 0);
1.238 deraadt 2748: packet_put_int((u_int)ws.ws_col);
2749: packet_put_int((u_int)ws.ws_row);
2750: packet_put_int((u_int)ws.ws_xpixel);
2751: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2752: packet_send();
2753: }
1.99 markus 2754: }
2755:
1.121 markus 2756: /* -- X11 forwarding */
1.1 deraadt 2757:
1.27 markus 2758: /*
2759: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2760: * Returns 0 and a suitable display number for the DISPLAY variable
2761: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2762: */
1.141 stevesk 2763: int
1.163 stevesk 2764: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2765: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2766: {
1.149 markus 2767: Channel *nc = NULL;
1.31 markus 2768: int display_number, sock;
2769: u_short port;
1.35 markus 2770: struct addrinfo hints, *ai, *aitop;
2771: char strport[NI_MAXSERV];
2772: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2773:
1.224 markus 2774: if (chanids == NULL)
2775: return -1;
2776:
1.33 markus 2777: for (display_number = x11_display_offset;
1.148 deraadt 2778: display_number < MAX_DISPLAYS;
2779: display_number++) {
1.25 markus 2780: port = 6000 + display_number;
1.35 markus 2781: memset(&hints, 0, sizeof(hints));
2782: hints.ai_family = IPv4or6;
1.163 stevesk 2783: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2784: hints.ai_socktype = SOCK_STREAM;
2785: snprintf(strport, sizeof strport, "%d", port);
2786: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2787: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2788: return -1;
1.25 markus 2789: }
1.35 markus 2790: for (ai = aitop; ai; ai = ai->ai_next) {
2791: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2792: continue;
1.189 markus 2793: sock = socket(ai->ai_family, ai->ai_socktype,
2794: ai->ai_protocol);
1.35 markus 2795: if (sock < 0) {
2796: error("socket: %.100s", strerror(errno));
1.203 markus 2797: freeaddrinfo(aitop);
1.141 stevesk 2798: return -1;
1.35 markus 2799: }
1.226 djm 2800: channel_set_reuseaddr(sock);
1.35 markus 2801: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2802: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2803: close(sock);
1.183 itojun 2804:
2805: if (ai->ai_next)
2806: continue;
2807:
1.35 markus 2808: for (n = 0; n < num_socks; n++) {
2809: close(socks[n]);
2810: }
2811: num_socks = 0;
2812: break;
2813: }
2814: socks[num_socks++] = sock;
2815: if (num_socks == NUM_SOCKS)
2816: break;
1.25 markus 2817: }
1.83 stevesk 2818: freeaddrinfo(aitop);
1.35 markus 2819: if (num_socks > 0)
2820: break;
1.25 markus 2821: }
2822: if (display_number >= MAX_DISPLAYS) {
2823: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2824: return -1;
1.25 markus 2825: }
2826: /* Start listening for connections on the socket. */
1.35 markus 2827: for (n = 0; n < num_socks; n++) {
2828: sock = socks[n];
1.199 markus 2829: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2830: error("listen: %.100s", strerror(errno));
2831: close(sock);
1.141 stevesk 2832: return -1;
1.35 markus 2833: }
1.25 markus 2834: }
1.35 markus 2835:
2836: /* Allocate a channel for each socket. */
1.242 djm 2837: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2838: for (n = 0; n < num_socks; n++) {
2839: sock = socks[n];
1.149 markus 2840: nc = channel_new("x11 listener",
1.51 markus 2841: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2842: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2843: 0, "X11 inet listener", 1);
1.167 markus 2844: nc->single_connection = single_connection;
1.224 markus 2845: (*chanids)[n] = nc->self;
1.35 markus 2846: }
1.224 markus 2847: (*chanids)[n] = -1;
1.1 deraadt 2848:
1.141 stevesk 2849: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2850: *display_numberp = display_number;
2851: return (0);
1.1 deraadt 2852: }
2853:
1.127 itojun 2854: static int
1.77 markus 2855: connect_local_xsocket(u_int dnr)
1.1 deraadt 2856: {
1.25 markus 2857: int sock;
2858: struct sockaddr_un addr;
2859:
1.147 stevesk 2860: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2861: if (sock < 0)
2862: error("socket: %.100s", strerror(errno));
2863: memset(&addr, 0, sizeof(addr));
2864: addr.sun_family = AF_UNIX;
2865: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2866: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2867: return sock;
2868: close(sock);
1.25 markus 2869: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2870: return -1;
1.1 deraadt 2871: }
2872:
1.51 markus 2873: int
2874: x11_connect_display(void)
1.1 deraadt 2875: {
1.248 deraadt 2876: u_int display_number;
1.25 markus 2877: const char *display;
1.51 markus 2878: char buf[1024], *cp;
1.35 markus 2879: struct addrinfo hints, *ai, *aitop;
2880: char strport[NI_MAXSERV];
1.248 deraadt 2881: int gaierr, sock = 0;
1.25 markus 2882:
2883: /* Try to open a socket for the local X server. */
2884: display = getenv("DISPLAY");
2885: if (!display) {
2886: error("DISPLAY not set.");
1.51 markus 2887: return -1;
1.25 markus 2888: }
1.27 markus 2889: /*
2890: * Now we decode the value of the DISPLAY variable and make a
2891: * connection to the real X server.
2892: */
2893:
2894: /*
2895: * Check if it is a unix domain socket. Unix domain displays are in
2896: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2897: */
1.25 markus 2898: if (strncmp(display, "unix:", 5) == 0 ||
2899: display[0] == ':') {
2900: /* Connect to the unix domain socket. */
1.248 deraadt 2901: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 2902: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2903: display);
1.51 markus 2904: return -1;
1.25 markus 2905: }
2906: /* Create a socket. */
2907: sock = connect_local_xsocket(display_number);
2908: if (sock < 0)
1.51 markus 2909: return -1;
1.25 markus 2910:
2911: /* OK, we now have a connection to the display. */
1.51 markus 2912: return sock;
1.25 markus 2913: }
1.27 markus 2914: /*
2915: * Connect to an inet socket. The DISPLAY value is supposedly
2916: * hostname:d[.s], where hostname may also be numeric IP address.
2917: */
1.145 stevesk 2918: strlcpy(buf, display, sizeof(buf));
1.25 markus 2919: cp = strchr(buf, ':');
2920: if (!cp) {
2921: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2922: return -1;
1.25 markus 2923: }
2924: *cp = 0;
1.27 markus 2925: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 2926: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 2927: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2928: display);
1.51 markus 2929: return -1;
1.25 markus 2930: }
1.35 markus 2931:
2932: /* Look up the host address */
2933: memset(&hints, 0, sizeof(hints));
2934: hints.ai_family = IPv4or6;
2935: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 2936: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 2937: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2938: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2939: return -1;
1.25 markus 2940: }
1.35 markus 2941: for (ai = aitop; ai; ai = ai->ai_next) {
2942: /* Create a socket. */
1.189 markus 2943: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2944: if (sock < 0) {
1.194 markus 2945: debug2("socket: %.100s", strerror(errno));
1.41 markus 2946: continue;
2947: }
2948: /* Connect it to the display. */
2949: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 2950: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 2951: 6000 + display_number, strerror(errno));
2952: close(sock);
2953: continue;
2954: }
2955: /* Success */
2956: break;
1.35 markus 2957: }
2958: freeaddrinfo(aitop);
2959: if (!ai) {
1.248 deraadt 2960: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 2961: strerror(errno));
1.51 markus 2962: return -1;
1.25 markus 2963: }
1.162 stevesk 2964: set_nodelay(sock);
1.51 markus 2965: return sock;
2966: }
2967:
2968: /*
2969: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2970: * the remote channel number. We should do whatever we want, and respond
2971: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2972: */
2973:
2974: void
1.154 markus 2975: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2976: {
1.113 markus 2977: Channel *c = NULL;
2978: int remote_id, sock = 0;
1.51 markus 2979: char *remote_host;
1.25 markus 2980:
1.113 markus 2981: debug("Received X11 open request.");
1.51 markus 2982:
1.113 markus 2983: remote_id = packet_get_int();
1.121 markus 2984:
2985: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2986: remote_host = packet_get_string(NULL);
1.51 markus 2987: } else {
2988: remote_host = xstrdup("unknown (remote did not supply name)");
2989: }
1.152 markus 2990: packet_check_eom();
1.25 markus 2991:
1.51 markus 2992: /* Obtain a connection to the real X display. */
2993: sock = x11_connect_display();
1.113 markus 2994: if (sock != -1) {
2995: /* Allocate a channel for this connection. */
2996: c = channel_new("connected x11 socket",
2997: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2998: remote_host, 1);
1.167 markus 2999: c->remote_id = remote_id;
3000: c->force_drain = 1;
1.113 markus 3001: }
1.190 markus 3002: xfree(remote_host);
1.113 markus 3003: if (c == NULL) {
1.51 markus 3004: /* Send refusal to the remote host. */
3005: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3006: packet_put_int(remote_id);
1.51 markus 3007: } else {
3008: /* Send a confirmation to the remote host. */
3009: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3010: packet_put_int(remote_id);
3011: packet_put_int(c->self);
1.51 markus 3012: }
1.113 markus 3013: packet_send();
1.72 markus 3014: }
3015:
3016: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3017: void
1.154 markus 3018: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3019: {
3020: int rchan = packet_get_int();
1.180 deraadt 3021:
1.143 deraadt 3022: switch (type) {
1.72 markus 3023: case SSH_SMSG_AGENT_OPEN:
3024: error("Warning: ssh server tried agent forwarding.");
3025: break;
3026: case SSH_SMSG_X11_OPEN:
3027: error("Warning: ssh server tried X11 forwarding.");
3028: break;
3029: default:
1.154 markus 3030: error("deny_input_open: type %d", type);
1.72 markus 3031: break;
3032: }
1.230 stevesk 3033: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3034: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3035: packet_put_int(rchan);
3036: packet_send();
1.1 deraadt 3037: }
3038:
1.27 markus 3039: /*
3040: * Requests forwarding of X11 connections, generates fake authentication
3041: * data, and enables authentication spoofing.
1.121 markus 3042: * This should be called in the client only.
1.27 markus 3043: */
1.49 markus 3044: void
1.215 djm 3045: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3046: const char *proto, const char *data)
1.1 deraadt 3047: {
1.77 markus 3048: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3049: u_int i, value;
1.25 markus 3050: char *new_data;
3051: int screen_number;
3052: const char *cp;
1.207 avsm 3053: u_int32_t rnd = 0;
1.25 markus 3054:
1.220 markus 3055: if (x11_saved_display == NULL)
3056: x11_saved_display = xstrdup(disp);
3057: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3058: error("x11_request_forwarding_with_spoofing: different "
3059: "$DISPLAY already forwarded");
3060: return;
3061: }
3062:
1.215 djm 3063: cp = disp;
3064: if (disp)
3065: cp = strchr(disp, ':');
1.25 markus 3066: if (cp)
3067: cp = strchr(cp, '.');
3068: if (cp)
1.245 deraadt 3069: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3070: else
3071: screen_number = 0;
3072:
1.219 djm 3073: if (x11_saved_proto == NULL) {
3074: /* Save protocol name. */
3075: x11_saved_proto = xstrdup(proto);
3076: /*
1.221 djm 3077: * Extract real authentication data and generate fake data
1.219 djm 3078: * of the same length.
3079: */
3080: x11_saved_data = xmalloc(data_len);
3081: x11_fake_data = xmalloc(data_len);
3082: for (i = 0; i < data_len; i++) {
3083: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3084: fatal("x11_request_forwarding: bad "
3085: "authentication data: %.100s", data);
3086: if (i % 4 == 0)
3087: rnd = arc4random();
3088: x11_saved_data[i] = value;
3089: x11_fake_data[i] = rnd & 0xff;
3090: rnd >>= 8;
3091: }
3092: x11_saved_data_len = data_len;
3093: x11_fake_data_len = data_len;
1.25 markus 3094: }
3095:
3096: /* Convert the fake data into hex. */
1.219 djm 3097: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3098:
3099: /* Send the request packet. */
1.51 markus 3100: if (compat20) {
3101: channel_request_start(client_session_id, "x11-req", 0);
3102: packet_put_char(0); /* XXX bool single connection */
3103: } else {
3104: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3105: }
3106: packet_put_cstring(proto);
3107: packet_put_cstring(new_data);
1.25 markus 3108: packet_put_int(screen_number);
3109: packet_send();
3110: packet_write_wait();
3111: xfree(new_data);
1.1 deraadt 3112: }
3113:
1.121 markus 3114:
3115: /* -- agent forwarding */
3116:
1.1 deraadt 3117: /* Sends a message to the server to request authentication fd forwarding. */
3118:
1.49 markus 3119: void
1.142 itojun 3120: auth_request_forwarding(void)
1.1 deraadt 3121: {
1.25 markus 3122: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3123: packet_send();
3124: packet_write_wait();
1.1 deraadt 3125: }
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