Annotation of src/usr.bin/ssh/channels.c, Revision 1.256
1.256 ! stevesk 1: /* $OpenBSD: channels.c,v 1.255 2006/07/12 22:28:51 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>
1.256 ! stevesk 55: #include <unistd.h>
1.1 deraadt 56:
57: #include "ssh.h"
1.82 markus 58: #include "ssh1.h"
59: #include "ssh2.h"
1.1 deraadt 60: #include "packet.h"
61: #include "xmalloc.h"
1.82 markus 62: #include "log.h"
63: #include "misc.h"
1.14 markus 64: #include "channels.h"
65: #include "compat.h"
1.82 markus 66: #include "canohost.h"
1.64 markus 67: #include "key.h"
68: #include "authfd.h"
1.147 stevesk 69: #include "pathnames.h"
1.193 markus 70: #include "bufaux.h"
1.1 deraadt 71:
1.121 markus 72: /* -- channel core */
1.12 markus 73:
1.27 markus 74: /*
75: * Pointer to an array containing all allocated channels. The array is
76: * dynamically extended as needed.
77: */
1.113 markus 78: static Channel **channels = NULL;
1.1 deraadt 79:
1.27 markus 80: /*
81: * Size of the channel array. All slots of the array must always be
1.113 markus 82: * initialized (at least the type field); unused slots set to NULL
1.27 markus 83: */
1.209 avsm 84: static u_int channels_alloc = 0;
1.1 deraadt 85:
1.27 markus 86: /*
87: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 88: * updated in channel_new.
1.27 markus 89: */
1.84 markus 90: static int channel_max_fd = 0;
1.1 deraadt 91:
92:
1.121 markus 93: /* -- tcp forwarding */
1.1 deraadt 94:
1.27 markus 95: /*
96: * Data structure for storing which hosts are permitted for forward requests.
97: * The local sides of any remote forwards are stored in this array to prevent
98: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
99: * network (which might be behind a firewall).
100: */
1.25 markus 101: typedef struct {
1.41 markus 102: char *host_to_connect; /* Connect to 'host'. */
103: u_short port_to_connect; /* Connect to 'port'. */
104: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 105: } ForwardPermission;
106:
107: /* List of all permitted host/port pairs to connect. */
108: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 109:
1.1 deraadt 110: /* Number of permitted host/port pairs in the array. */
111: static int num_permitted_opens = 0;
1.27 markus 112: /*
113: * If this is true, all opens are permitted. This is the case on the server
114: * on which we have to trust the client anyway, and the user could do
115: * anything after logging in anyway.
116: */
1.1 deraadt 117: static int all_opens_permitted = 0;
118:
1.121 markus 119:
120: /* -- X11 forwarding */
121:
122: /* Maximum number of fake X11 displays to try. */
123: #define MAX_DISPLAYS 1000
124:
1.219 djm 125: /* Saved X11 local (client) display. */
126: static char *x11_saved_display = NULL;
127:
1.121 markus 128: /* Saved X11 authentication protocol name. */
129: static char *x11_saved_proto = NULL;
130:
131: /* Saved X11 authentication data. This is the real data. */
132: static char *x11_saved_data = NULL;
133: static u_int x11_saved_data_len = 0;
134:
135: /*
136: * Fake X11 authentication data. This is what the server will be sending us;
137: * we should replace any occurrences of this by the real data.
138: */
1.240 deraadt 139: static u_char *x11_fake_data = NULL;
1.121 markus 140: static u_int x11_fake_data_len;
141:
142:
143: /* -- agent forwarding */
144:
145: #define NUM_SOCKS 10
146:
1.82 markus 147: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 148: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 149:
1.121 markus 150: /* helper */
1.127 itojun 151: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 152:
1.121 markus 153: /* -- channel core */
1.41 markus 154:
155: Channel *
1.229 markus 156: channel_by_id(int id)
1.41 markus 157: {
158: Channel *c;
1.113 markus 159:
1.209 avsm 160: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 161: logit("channel_by_id: %d: bad id", id);
1.41 markus 162: return NULL;
163: }
1.113 markus 164: c = channels[id];
165: if (c == NULL) {
1.229 markus 166: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 167: return NULL;
168: }
169: return c;
1.55 markus 170: }
171:
1.27 markus 172: /*
1.229 markus 173: * Returns the channel if it is allowed to receive protocol messages.
174: * Private channels, like listening sockets, may not receive messages.
175: */
176: Channel *
177: channel_lookup(int id)
178: {
179: Channel *c;
180:
181: if ((c = channel_by_id(id)) == NULL)
182: return (NULL);
183:
1.237 deraadt 184: switch (c->type) {
1.229 markus 185: case SSH_CHANNEL_X11_OPEN:
186: case SSH_CHANNEL_LARVAL:
187: case SSH_CHANNEL_CONNECTING:
188: case SSH_CHANNEL_DYNAMIC:
189: case SSH_CHANNEL_OPENING:
190: case SSH_CHANNEL_OPEN:
191: case SSH_CHANNEL_INPUT_DRAINING:
192: case SSH_CHANNEL_OUTPUT_DRAINING:
193: return (c);
194: }
195: logit("Non-public channel %d, type %d.", id, c->type);
196: return (NULL);
197: }
198:
199: /*
1.55 markus 200: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 201: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 202: */
1.127 itojun 203: static void
1.71 markus 204: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
205: int extusage, int nonblock)
1.1 deraadt 206: {
1.25 markus 207: /* Update the maximum file descriptor value. */
1.84 markus 208: channel_max_fd = MAX(channel_max_fd, rfd);
209: channel_max_fd = MAX(channel_max_fd, wfd);
210: channel_max_fd = MAX(channel_max_fd, efd);
211:
1.27 markus 212: /* XXX set close-on-exec -markus */
1.55 markus 213:
1.52 markus 214: c->rfd = rfd;
215: c->wfd = wfd;
216: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 217: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 218: c->efd = efd;
219: c->extended_usage = extusage;
1.71 markus 220:
1.91 markus 221: /* XXX ugly hack: nonblock is only set by the server */
222: if (nonblock && isatty(c->rfd)) {
1.194 markus 223: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 224: c->isatty = 1;
225: if (!isatty(c->wfd)) {
1.94 markus 226: error("channel %d: wfd %d is not a tty?",
1.91 markus 227: c->self, c->wfd);
228: }
229: } else {
230: c->isatty = 0;
231: }
232:
1.71 markus 233: /* enable nonblocking mode */
234: if (nonblock) {
235: if (rfd != -1)
236: set_nonblock(rfd);
237: if (wfd != -1)
238: set_nonblock(wfd);
239: if (efd != -1)
240: set_nonblock(efd);
241: }
1.52 markus 242: }
243:
244: /*
245: * Allocate a new channel object and set its type and socket. This will cause
246: * remote_name to be freed.
247: */
1.113 markus 248: Channel *
1.52 markus 249: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 250: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 251: {
1.209 avsm 252: int found;
253: u_int i;
1.52 markus 254: Channel *c;
1.25 markus 255:
256: /* Do initial allocation if this is the first call. */
257: if (channels_alloc == 0) {
258: channels_alloc = 10;
1.242 djm 259: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 260: for (i = 0; i < channels_alloc; i++)
1.113 markus 261: channels[i] = NULL;
1.25 markus 262: }
263: /* Try to find a free slot where to put the new channel. */
264: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 265: if (channels[i] == NULL) {
1.25 markus 266: /* Found a free slot. */
1.209 avsm 267: found = (int)i;
1.25 markus 268: break;
269: }
1.209 avsm 270: if (found < 0) {
1.27 markus 271: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 272: found = channels_alloc;
1.179 markus 273: if (channels_alloc > 10000)
274: fatal("channel_new: internal error: channels_alloc %d "
275: "too big.", channels_alloc);
1.243 djm 276: channels = xrealloc(channels, channels_alloc + 10,
277: sizeof(Channel *));
1.195 markus 278: channels_alloc += 10;
1.70 markus 279: debug2("channel: expanding %d", channels_alloc);
1.25 markus 280: for (i = found; i < channels_alloc; i++)
1.113 markus 281: channels[i] = NULL;
1.25 markus 282: }
1.113 markus 283: /* Initialize and return new channel. */
1.242 djm 284: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 285: buffer_init(&c->input);
286: buffer_init(&c->output);
1.41 markus 287: buffer_init(&c->extended);
1.159 markus 288: c->ostate = CHAN_OUTPUT_OPEN;
289: c->istate = CHAN_INPUT_OPEN;
290: c->flags = 0;
1.71 markus 291: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 292: c->self = found;
293: c->type = type;
1.41 markus 294: c->ctype = ctype;
1.51 markus 295: c->local_window = window;
296: c->local_window_max = window;
297: c->local_consumed = 0;
298: c->local_maxpacket = maxpack;
1.25 markus 299: c->remote_id = -1;
1.190 markus 300: c->remote_name = xstrdup(remote_name);
1.41 markus 301: c->remote_window = 0;
302: c->remote_maxpacket = 0;
1.133 markus 303: c->force_drain = 0;
1.149 markus 304: c->single_connection = 0;
1.131 markus 305: c->detach_user = NULL;
1.225 djm 306: c->detach_close = 0;
1.165 markus 307: c->confirm = NULL;
1.204 djm 308: c->confirm_ctx = NULL;
1.65 markus 309: c->input_filter = NULL;
1.231 reyk 310: c->output_filter = NULL;
1.25 markus 311: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 312: return c;
1.1 deraadt 313: }
1.52 markus 314:
1.132 markus 315: static int
316: channel_find_maxfd(void)
317: {
1.209 avsm 318: u_int i;
319: int max = 0;
1.132 markus 320: Channel *c;
321:
322: for (i = 0; i < channels_alloc; i++) {
323: c = channels[i];
324: if (c != NULL) {
325: max = MAX(max, c->rfd);
326: max = MAX(max, c->wfd);
327: max = MAX(max, c->efd);
328: }
329: }
330: return max;
331: }
332:
333: int
334: channel_close_fd(int *fdp)
335: {
336: int ret = 0, fd = *fdp;
337:
338: if (fd != -1) {
339: ret = close(fd);
340: *fdp = -1;
341: if (fd == channel_max_fd)
342: channel_max_fd = channel_find_maxfd();
343: }
344: return ret;
345: }
346:
1.52 markus 347: /* Close all channel fd/socket. */
1.127 itojun 348: static void
1.52 markus 349: channel_close_fds(Channel *c)
350: {
1.204 djm 351: debug3("channel %d: close_fds r %d w %d e %d c %d",
352: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 353:
1.132 markus 354: channel_close_fd(&c->sock);
1.204 djm 355: channel_close_fd(&c->ctl_fd);
1.132 markus 356: channel_close_fd(&c->rfd);
357: channel_close_fd(&c->wfd);
358: channel_close_fd(&c->efd);
1.121 markus 359: }
360:
361: /* Free the channel and close its fd/socket. */
362: void
363: channel_free(Channel *c)
364: {
365: char *s;
1.209 avsm 366: u_int i, n;
1.121 markus 367:
368: for (n = 0, i = 0; i < channels_alloc; i++)
369: if (channels[i])
370: n++;
1.209 avsm 371: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 372: c->remote_name ? c->remote_name : "???", n);
373:
374: s = channel_open_message();
1.194 markus 375: debug3("channel %d: status: %s", c->self, s);
1.121 markus 376: xfree(s);
377:
378: if (c->sock != -1)
379: shutdown(c->sock, SHUT_RDWR);
1.204 djm 380: if (c->ctl_fd != -1)
381: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 382: channel_close_fds(c);
383: buffer_free(&c->input);
384: buffer_free(&c->output);
385: buffer_free(&c->extended);
386: if (c->remote_name) {
387: xfree(c->remote_name);
388: c->remote_name = NULL;
389: }
390: channels[c->self] = NULL;
391: xfree(c);
392: }
393:
394: void
1.126 markus 395: channel_free_all(void)
1.121 markus 396: {
1.209 avsm 397: u_int i;
1.121 markus 398:
1.126 markus 399: for (i = 0; i < channels_alloc; i++)
400: if (channels[i] != NULL)
401: channel_free(channels[i]);
1.131 markus 402: }
403:
1.121 markus 404: /*
405: * Closes the sockets/fds of all channels. This is used to close extra file
406: * descriptors after a fork.
407: */
408: void
1.142 itojun 409: channel_close_all(void)
1.121 markus 410: {
1.209 avsm 411: u_int i;
1.121 markus 412:
413: for (i = 0; i < channels_alloc; i++)
414: if (channels[i] != NULL)
415: channel_close_fds(channels[i]);
416: }
417:
418: /*
1.131 markus 419: * Stop listening to channels.
420: */
421: void
422: channel_stop_listening(void)
423: {
1.209 avsm 424: u_int i;
1.131 markus 425: Channel *c;
426:
427: for (i = 0; i < channels_alloc; i++) {
428: c = channels[i];
429: if (c != NULL) {
430: switch (c->type) {
431: case SSH_CHANNEL_AUTH_SOCKET:
432: case SSH_CHANNEL_PORT_LISTENER:
433: case SSH_CHANNEL_RPORT_LISTENER:
434: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 435: channel_close_fd(&c->sock);
1.131 markus 436: channel_free(c);
437: break;
438: }
439: }
440: }
441: }
442:
443: /*
1.121 markus 444: * Returns true if no channel has too much buffered data, and false if one or
445: * more channel is overfull.
446: */
447: int
1.142 itojun 448: channel_not_very_much_buffered_data(void)
1.121 markus 449: {
450: u_int i;
451: Channel *c;
452:
453: for (i = 0; i < channels_alloc; i++) {
454: c = channels[i];
455: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 456: #if 0
457: if (!compat20 &&
458: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 459: debug2("channel %d: big input buffer %d",
1.121 markus 460: c->self, buffer_len(&c->input));
461: return 0;
462: }
1.136 markus 463: #endif
1.121 markus 464: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 465: debug2("channel %d: big output buffer %u > %u",
1.136 markus 466: c->self, buffer_len(&c->output),
467: packet_get_maxsize());
1.121 markus 468: return 0;
469: }
470: }
471: }
472: return 1;
473: }
474:
475: /* Returns true if any channel is still open. */
476: int
1.142 itojun 477: channel_still_open(void)
1.121 markus 478: {
1.209 avsm 479: u_int i;
1.121 markus 480: Channel *c;
481:
482: for (i = 0; i < channels_alloc; i++) {
483: c = channels[i];
484: if (c == NULL)
485: continue;
486: switch (c->type) {
487: case SSH_CHANNEL_X11_LISTENER:
488: case SSH_CHANNEL_PORT_LISTENER:
489: case SSH_CHANNEL_RPORT_LISTENER:
490: case SSH_CHANNEL_CLOSED:
491: case SSH_CHANNEL_AUTH_SOCKET:
492: case SSH_CHANNEL_DYNAMIC:
493: case SSH_CHANNEL_CONNECTING:
494: case SSH_CHANNEL_ZOMBIE:
495: continue;
496: case SSH_CHANNEL_LARVAL:
497: if (!compat20)
498: fatal("cannot happen: SSH_CHANNEL_LARVAL");
499: continue;
500: case SSH_CHANNEL_OPENING:
501: case SSH_CHANNEL_OPEN:
502: case SSH_CHANNEL_X11_OPEN:
503: return 1;
504: case SSH_CHANNEL_INPUT_DRAINING:
505: case SSH_CHANNEL_OUTPUT_DRAINING:
506: if (!compat13)
507: fatal("cannot happen: OUT_DRAIN");
508: return 1;
509: default:
510: fatal("channel_still_open: bad channel type %d", c->type);
511: /* NOTREACHED */
512: }
513: }
514: return 0;
515: }
516:
517: /* Returns the id of an open channel suitable for keepaliving */
518: int
1.142 itojun 519: channel_find_open(void)
1.121 markus 520: {
1.209 avsm 521: u_int i;
1.121 markus 522: Channel *c;
523:
524: for (i = 0; i < channels_alloc; i++) {
525: c = channels[i];
1.206 djm 526: if (c == NULL || c->remote_id < 0)
1.121 markus 527: continue;
528: switch (c->type) {
529: case SSH_CHANNEL_CLOSED:
530: case SSH_CHANNEL_DYNAMIC:
531: case SSH_CHANNEL_X11_LISTENER:
532: case SSH_CHANNEL_PORT_LISTENER:
533: case SSH_CHANNEL_RPORT_LISTENER:
534: case SSH_CHANNEL_OPENING:
535: case SSH_CHANNEL_CONNECTING:
536: case SSH_CHANNEL_ZOMBIE:
537: continue;
538: case SSH_CHANNEL_LARVAL:
539: case SSH_CHANNEL_AUTH_SOCKET:
540: case SSH_CHANNEL_OPEN:
541: case SSH_CHANNEL_X11_OPEN:
542: return i;
543: case SSH_CHANNEL_INPUT_DRAINING:
544: case SSH_CHANNEL_OUTPUT_DRAINING:
545: if (!compat13)
546: fatal("cannot happen: OUT_DRAIN");
547: return i;
548: default:
549: fatal("channel_find_open: bad channel type %d", c->type);
550: /* NOTREACHED */
551: }
552: }
553: return -1;
554: }
555:
556:
557: /*
558: * Returns a message describing the currently open forwarded connections,
559: * suitable for sending to the client. The message contains crlf pairs for
560: * newlines.
561: */
562: char *
1.142 itojun 563: channel_open_message(void)
1.121 markus 564: {
565: Buffer buffer;
566: Channel *c;
567: char buf[1024], *cp;
1.209 avsm 568: u_int i;
1.121 markus 569:
570: buffer_init(&buffer);
571: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
572: buffer_append(&buffer, buf, strlen(buf));
573: for (i = 0; i < channels_alloc; i++) {
574: c = channels[i];
575: if (c == NULL)
576: continue;
577: switch (c->type) {
578: case SSH_CHANNEL_X11_LISTENER:
579: case SSH_CHANNEL_PORT_LISTENER:
580: case SSH_CHANNEL_RPORT_LISTENER:
581: case SSH_CHANNEL_CLOSED:
582: case SSH_CHANNEL_AUTH_SOCKET:
583: case SSH_CHANNEL_ZOMBIE:
584: continue;
585: case SSH_CHANNEL_LARVAL:
586: case SSH_CHANNEL_OPENING:
587: case SSH_CHANNEL_CONNECTING:
588: case SSH_CHANNEL_DYNAMIC:
589: case SSH_CHANNEL_OPEN:
590: case SSH_CHANNEL_X11_OPEN:
591: case SSH_CHANNEL_INPUT_DRAINING:
592: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 593: snprintf(buf, sizeof buf,
594: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 595: c->self, c->remote_name,
596: c->type, c->remote_id,
597: c->istate, buffer_len(&c->input),
598: c->ostate, buffer_len(&c->output),
1.204 djm 599: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 600: buffer_append(&buffer, buf, strlen(buf));
601: continue;
602: default:
603: fatal("channel_open_message: bad channel type %d", c->type);
604: /* NOTREACHED */
605: }
606: }
607: buffer_append(&buffer, "\0", 1);
608: cp = xstrdup(buffer_ptr(&buffer));
609: buffer_free(&buffer);
610: return cp;
611: }
612:
613: void
614: channel_send_open(int id)
615: {
616: Channel *c = channel_lookup(id);
1.180 deraadt 617:
1.121 markus 618: if (c == NULL) {
1.188 itojun 619: logit("channel_send_open: %d: bad id", id);
1.121 markus 620: return;
621: }
1.184 markus 622: debug2("channel %d: send open", id);
1.121 markus 623: packet_start(SSH2_MSG_CHANNEL_OPEN);
624: packet_put_cstring(c->ctype);
625: packet_put_int(c->self);
626: packet_put_int(c->local_window);
627: packet_put_int(c->local_maxpacket);
628: packet_send();
629: }
630:
631: void
1.184 markus 632: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 633: {
1.184 markus 634: Channel *c = channel_lookup(id);
1.180 deraadt 635:
1.121 markus 636: if (c == NULL) {
1.188 itojun 637: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 638: return;
639: }
1.204 djm 640: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 641: packet_start(SSH2_MSG_CHANNEL_REQUEST);
642: packet_put_int(c->remote_id);
643: packet_put_cstring(service);
644: packet_put_char(wantconfirm);
645: }
1.241 deraadt 646:
1.121 markus 647: void
1.204 djm 648: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 649: {
650: Channel *c = channel_lookup(id);
1.180 deraadt 651:
1.121 markus 652: if (c == NULL) {
1.188 itojun 653: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 654: return;
655: }
1.165 markus 656: c->confirm = fn;
1.204 djm 657: c->confirm_ctx = ctx;
1.121 markus 658: }
1.241 deraadt 659:
1.121 markus 660: void
1.225 djm 661: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 662: {
1.229 markus 663: Channel *c = channel_by_id(id);
1.180 deraadt 664:
1.121 markus 665: if (c == NULL) {
1.188 itojun 666: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 667: return;
668: }
1.131 markus 669: c->detach_user = fn;
1.225 djm 670: c->detach_close = do_close;
1.121 markus 671: }
1.241 deraadt 672:
1.121 markus 673: void
674: channel_cancel_cleanup(int id)
675: {
1.229 markus 676: Channel *c = channel_by_id(id);
1.180 deraadt 677:
1.121 markus 678: if (c == NULL) {
1.188 itojun 679: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 680: return;
1.52 markus 681: }
1.131 markus 682: c->detach_user = NULL;
1.225 djm 683: c->detach_close = 0;
1.121 markus 684: }
1.241 deraadt 685:
1.121 markus 686: void
1.231 reyk 687: channel_register_filter(int id, channel_infilter_fn *ifn,
688: channel_outfilter_fn *ofn)
1.121 markus 689: {
690: Channel *c = channel_lookup(id);
1.180 deraadt 691:
1.121 markus 692: if (c == NULL) {
1.188 itojun 693: logit("channel_register_filter: %d: bad id", id);
1.121 markus 694: return;
1.52 markus 695: }
1.231 reyk 696: c->input_filter = ifn;
697: c->output_filter = ofn;
1.52 markus 698: }
699:
1.49 markus 700: void
1.121 markus 701: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 702: int extusage, int nonblock, u_int window_max)
1.1 deraadt 703: {
1.121 markus 704: Channel *c = channel_lookup(id);
1.180 deraadt 705:
1.121 markus 706: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
707: fatal("channel_activate for non-larval channel %d.", id);
708: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
709: c->type = SSH_CHANNEL_OPEN;
1.168 markus 710: c->local_window = c->local_window_max = window_max;
1.121 markus 711: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
712: packet_put_int(c->remote_id);
713: packet_put_int(c->local_window);
714: packet_send();
1.1 deraadt 715: }
716:
1.27 markus 717: /*
1.41 markus 718: * 'channel_pre*' are called just before select() to add any bits relevant to
719: * channels in the select bitmasks.
720: */
721: /*
722: * 'channel_post*': perform any appropriate operations for channels which
723: * have events pending.
1.27 markus 724: */
1.237 deraadt 725: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 726: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
727: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
728:
1.127 itojun 729: static void
1.237 deraadt 730: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 731: {
732: FD_SET(c->sock, readset);
733: }
734:
1.127 itojun 735: static void
1.237 deraadt 736: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 737: {
738: debug3("channel %d: waiting for connection", c->self);
739: FD_SET(c->sock, writeset);
740: }
741:
1.127 itojun 742: static void
1.237 deraadt 743: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 744: {
745: if (buffer_len(&c->input) < packet_get_maxsize())
746: FD_SET(c->sock, readset);
747: if (buffer_len(&c->output) > 0)
748: FD_SET(c->sock, writeset);
749: }
1.1 deraadt 750:
1.127 itojun 751: static void
1.237 deraadt 752: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 753: {
1.157 markus 754: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 755:
1.44 markus 756: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 757: limit > 0 &&
1.250 djm 758: buffer_len(&c->input) < limit &&
759: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 760: FD_SET(c->rfd, readset);
761: if (c->ostate == CHAN_OUTPUT_OPEN ||
762: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
763: if (buffer_len(&c->output) > 0) {
764: FD_SET(c->wfd, writeset);
765: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 766: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 767: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
768: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 769: else
770: chan_obuf_empty(c);
1.44 markus 771: }
772: }
773: /** XXX check close conditions, too */
1.157 markus 774: if (compat20 && c->efd != -1) {
1.44 markus 775: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
776: buffer_len(&c->extended) > 0)
777: FD_SET(c->efd, writeset);
1.172 markus 778: else if (!(c->flags & CHAN_EOF_SENT) &&
779: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 780: buffer_len(&c->extended) < c->remote_window)
781: FD_SET(c->efd, readset);
782: }
1.204 djm 783: /* XXX: What about efd? races? */
1.208 deraadt 784: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 785: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
786: FD_SET(c->ctl_fd, readset);
1.44 markus 787: }
788:
1.127 itojun 789: static void
1.237 deraadt 790: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 791: {
792: if (buffer_len(&c->input) == 0) {
793: packet_start(SSH_MSG_CHANNEL_CLOSE);
794: packet_put_int(c->remote_id);
795: packet_send();
796: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 797: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 798: }
799: }
800:
1.127 itojun 801: static void
1.237 deraadt 802: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 803: {
804: if (buffer_len(&c->output) == 0)
1.113 markus 805: chan_mark_dead(c);
1.49 markus 806: else
1.41 markus 807: FD_SET(c->sock, writeset);
808: }
809:
810: /*
811: * This is a special state for X11 authentication spoofing. An opened X11
812: * connection (when authentication spoofing is being done) remains in this
813: * state until the first packet has been completely read. The authentication
814: * data in that packet is then substituted by the real data if it matches the
815: * fake data, and the channel is put into normal mode.
1.51 markus 816: * XXX All this happens at the client side.
1.121 markus 817: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 818: */
1.127 itojun 819: static int
1.121 markus 820: x11_open_helper(Buffer *b)
1.1 deraadt 821: {
1.77 markus 822: u_char *ucp;
823: u_int proto_len, data_len;
1.25 markus 824:
1.41 markus 825: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 826: if (buffer_len(b) < 12)
1.41 markus 827: return 0;
828:
829: /* Parse the lengths of variable-length fields. */
1.155 stevesk 830: ucp = buffer_ptr(b);
1.41 markus 831: if (ucp[0] == 0x42) { /* Byte order MSB first. */
832: proto_len = 256 * ucp[6] + ucp[7];
833: data_len = 256 * ucp[8] + ucp[9];
834: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
835: proto_len = ucp[6] + 256 * ucp[7];
836: data_len = ucp[8] + 256 * ucp[9];
837: } else {
1.194 markus 838: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 839: ucp[0]);
1.41 markus 840: return -1;
841: }
842:
843: /* Check if the whole packet is in buffer. */
1.121 markus 844: if (buffer_len(b) <
1.41 markus 845: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
846: return 0;
847:
848: /* Check if authentication protocol matches. */
849: if (proto_len != strlen(x11_saved_proto) ||
850: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 851: debug2("X11 connection uses different authentication protocol.");
1.41 markus 852: return -1;
853: }
854: /* Check if authentication data matches our fake data. */
855: if (data_len != x11_fake_data_len ||
856: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
857: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 858: debug2("X11 auth data does not match fake data.");
1.41 markus 859: return -1;
860: }
861: /* Check fake data length */
862: if (x11_fake_data_len != x11_saved_data_len) {
863: error("X11 fake_data_len %d != saved_data_len %d",
864: x11_fake_data_len, x11_saved_data_len);
865: return -1;
866: }
867: /*
868: * Received authentication protocol and data match
869: * our fake data. Substitute the fake data with real
870: * data.
871: */
872: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
873: x11_saved_data, x11_saved_data_len);
874: return 1;
875: }
876:
1.127 itojun 877: static void
1.237 deraadt 878: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 879: {
1.121 markus 880: int ret = x11_open_helper(&c->output);
1.180 deraadt 881:
1.41 markus 882: if (ret == 1) {
883: /* Start normal processing for the channel. */
884: c->type = SSH_CHANNEL_OPEN;
1.47 markus 885: channel_pre_open_13(c, readset, writeset);
1.41 markus 886: } else if (ret == -1) {
887: /*
888: * We have received an X11 connection that has bad
889: * authentication information.
890: */
1.188 itojun 891: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 892: buffer_clear(&c->input);
893: buffer_clear(&c->output);
1.132 markus 894: channel_close_fd(&c->sock);
1.41 markus 895: c->sock = -1;
896: c->type = SSH_CHANNEL_CLOSED;
897: packet_start(SSH_MSG_CHANNEL_CLOSE);
898: packet_put_int(c->remote_id);
899: packet_send();
900: }
901: }
1.25 markus 902:
1.127 itojun 903: static void
1.237 deraadt 904: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 905: {
1.121 markus 906: int ret = x11_open_helper(&c->output);
1.133 markus 907:
908: /* c->force_drain = 1; */
909:
1.41 markus 910: if (ret == 1) {
911: c->type = SSH_CHANNEL_OPEN;
1.157 markus 912: channel_pre_open(c, readset, writeset);
1.41 markus 913: } else if (ret == -1) {
1.188 itojun 914: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 915: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 916: chan_read_failed(c);
917: buffer_clear(&c->input);
918: chan_ibuf_empty(c);
919: buffer_clear(&c->output);
920: /* for proto v1, the peer will send an IEOF */
921: if (compat20)
922: chan_write_failed(c);
923: else
924: c->type = SSH_CHANNEL_OPEN;
1.194 markus 925: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 926: }
927: }
1.25 markus 928:
1.104 markus 929: /* try to decode a socks4 header */
1.127 itojun 930: static int
1.237 deraadt 931: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 932: {
1.181 markus 933: char *p, *host;
1.217 djm 934: u_int len, have, i, found;
1.148 deraadt 935: char username[256];
1.103 markus 936: struct {
937: u_int8_t version;
938: u_int8_t command;
939: u_int16_t dest_port;
1.104 markus 940: struct in_addr dest_addr;
1.103 markus 941: } s4_req, s4_rsp;
942:
1.104 markus 943: debug2("channel %d: decode socks4", c->self);
1.109 markus 944:
945: have = buffer_len(&c->input);
946: len = sizeof(s4_req);
947: if (have < len)
948: return 0;
949: p = buffer_ptr(&c->input);
950: for (found = 0, i = len; i < have; i++) {
951: if (p[i] == '\0') {
952: found = 1;
953: break;
954: }
955: if (i > 1024) {
956: /* the peer is probably sending garbage */
957: debug("channel %d: decode socks4: too long",
958: c->self);
959: return -1;
960: }
961: }
962: if (!found)
963: return 0;
1.103 markus 964: buffer_get(&c->input, (char *)&s4_req.version, 1);
965: buffer_get(&c->input, (char *)&s4_req.command, 1);
966: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 967: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 968: have = buffer_len(&c->input);
1.103 markus 969: p = buffer_ptr(&c->input);
970: len = strlen(p);
1.106 markus 971: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 972: if (len > have)
1.104 markus 973: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 974: c->self, len, have);
975: strlcpy(username, p, sizeof(username));
976: buffer_consume(&c->input, len);
977: buffer_consume(&c->input, 1); /* trailing '\0' */
978:
1.104 markus 979: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 980: strlcpy(c->path, host, sizeof(c->path));
981: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 982:
1.194 markus 983: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 984: c->self, host, c->host_port, s4_req.command);
1.103 markus 985:
1.104 markus 986: if (s4_req.command != 1) {
987: debug("channel %d: cannot handle: socks4 cn %d",
988: c->self, s4_req.command);
989: return -1;
1.103 markus 990: }
1.104 markus 991: s4_rsp.version = 0; /* vn: 0 for reply */
992: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 993: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 994: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 995: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 996: return 1;
997: }
998:
1.193 markus 999: /* try to decode a socks5 header */
1000: #define SSH_SOCKS5_AUTHDONE 0x1000
1001: #define SSH_SOCKS5_NOAUTH 0x00
1002: #define SSH_SOCKS5_IPV4 0x01
1003: #define SSH_SOCKS5_DOMAIN 0x03
1004: #define SSH_SOCKS5_IPV6 0x04
1005: #define SSH_SOCKS5_CONNECT 0x01
1006: #define SSH_SOCKS5_SUCCESS 0x00
1007:
1008: static int
1.237 deraadt 1009: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1010: {
1011: struct {
1012: u_int8_t version;
1013: u_int8_t command;
1014: u_int8_t reserved;
1015: u_int8_t atyp;
1016: } s5_req, s5_rsp;
1017: u_int16_t dest_port;
1018: u_char *p, dest_addr[255+1];
1.252 djm 1019: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1020:
1021: debug2("channel %d: decode socks5", c->self);
1022: p = buffer_ptr(&c->input);
1023: if (p[0] != 0x05)
1024: return -1;
1025: have = buffer_len(&c->input);
1026: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1027: /* format: ver | nmethods | methods */
1.198 djm 1028: if (have < 2)
1.193 markus 1029: return 0;
1030: nmethods = p[1];
1031: if (have < nmethods + 2)
1032: return 0;
1033: /* look for method: "NO AUTHENTICATION REQUIRED" */
1034: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1035: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1036: found = 1;
1037: break;
1038: }
1039: }
1040: if (!found) {
1041: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1042: c->self);
1043: return -1;
1044: }
1045: buffer_consume(&c->input, nmethods + 2);
1046: buffer_put_char(&c->output, 0x05); /* version */
1047: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1048: FD_SET(c->sock, writeset);
1049: c->flags |= SSH_SOCKS5_AUTHDONE;
1050: debug2("channel %d: socks5 auth done", c->self);
1051: return 0; /* need more */
1052: }
1053: debug2("channel %d: socks5 post auth", c->self);
1054: if (have < sizeof(s5_req)+1)
1055: return 0; /* need more */
1.247 deraadt 1056: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1057: if (s5_req.version != 0x05 ||
1058: s5_req.command != SSH_SOCKS5_CONNECT ||
1059: s5_req.reserved != 0x00) {
1.194 markus 1060: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1061: return -1;
1062: }
1.213 deraadt 1063: switch (s5_req.atyp){
1.193 markus 1064: case SSH_SOCKS5_IPV4:
1065: addrlen = 4;
1066: af = AF_INET;
1067: break;
1068: case SSH_SOCKS5_DOMAIN:
1069: addrlen = p[sizeof(s5_req)];
1070: af = -1;
1071: break;
1072: case SSH_SOCKS5_IPV6:
1073: addrlen = 16;
1074: af = AF_INET6;
1075: break;
1076: default:
1.194 markus 1077: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1078: return -1;
1079: }
1.252 djm 1080: need = sizeof(s5_req) + addrlen + 2;
1081: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1082: need++;
1083: if (have < need)
1.193 markus 1084: return 0;
1085: buffer_consume(&c->input, sizeof(s5_req));
1086: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1087: buffer_consume(&c->input, 1); /* host string length */
1088: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1089: buffer_get(&c->input, (char *)&dest_port, 2);
1090: dest_addr[addrlen] = '\0';
1091: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1092: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1093: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1094: return -1;
1095: c->host_port = ntohs(dest_port);
1.198 djm 1096:
1.194 markus 1097: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1098: c->self, c->path, c->host_port, s5_req.command);
1099:
1100: s5_rsp.version = 0x05;
1101: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1102: s5_rsp.reserved = 0; /* ignored */
1103: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1104: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1105: dest_port = 0; /* ignored */
1106:
1.246 deraadt 1107: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1108: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1109: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1110: return 1;
1111: }
1112:
1.104 markus 1113: /* dynamic port forwarding */
1.127 itojun 1114: static void
1.237 deraadt 1115: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1116: {
1117: u_char *p;
1.217 djm 1118: u_int have;
1119: int ret;
1.103 markus 1120:
1.104 markus 1121: have = buffer_len(&c->input);
1.137 markus 1122: c->delayed = 0;
1.104 markus 1123: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1124: /* buffer_dump(&c->input); */
1.104 markus 1125: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1126: if (have < 3) {
1.104 markus 1127: /* need more */
1128: FD_SET(c->sock, readset);
1129: return;
1130: }
1131: /* try to guess the protocol */
1132: p = buffer_ptr(&c->input);
1133: switch (p[0]) {
1134: case 0x04:
1135: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1136: break;
1137: case 0x05:
1138: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1139: break;
1140: default:
1141: ret = -1;
1142: break;
1143: }
1144: if (ret < 0) {
1.113 markus 1145: chan_mark_dead(c);
1.104 markus 1146: } else if (ret == 0) {
1147: debug2("channel %d: pre_dynamic: need more", c->self);
1148: /* need more */
1149: FD_SET(c->sock, readset);
1150: } else {
1151: /* switch to the next state */
1152: c->type = SSH_CHANNEL_OPENING;
1153: port_open_helper(c, "direct-tcpip");
1154: }
1.103 markus 1155: }
1156:
1.41 markus 1157: /* This is our fake X11 server socket. */
1.127 itojun 1158: static void
1.237 deraadt 1159: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1160: {
1.113 markus 1161: Channel *nc;
1.41 markus 1162: struct sockaddr addr;
1.162 stevesk 1163: int newsock;
1.41 markus 1164: socklen_t addrlen;
1.85 markus 1165: char buf[16384], *remote_ipaddr;
1.51 markus 1166: int remote_port;
1.25 markus 1167:
1.41 markus 1168: if (FD_ISSET(c->sock, readset)) {
1169: debug("X11 connection requested.");
1170: addrlen = sizeof(addr);
1171: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1172: if (c->single_connection) {
1.194 markus 1173: debug2("single_connection: closing X11 listener.");
1.149 markus 1174: channel_close_fd(&c->sock);
1175: chan_mark_dead(c);
1176: }
1.41 markus 1177: if (newsock < 0) {
1178: error("accept: %.100s", strerror(errno));
1179: return;
1180: }
1.162 stevesk 1181: set_nodelay(newsock);
1.85 markus 1182: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1183: remote_port = get_peer_port(newsock);
1.41 markus 1184: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1185: remote_ipaddr, remote_port);
1.51 markus 1186:
1.113 markus 1187: nc = channel_new("accepted x11 socket",
1.51 markus 1188: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1189: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1190: if (compat20) {
1191: packet_start(SSH2_MSG_CHANNEL_OPEN);
1192: packet_put_cstring("x11");
1.113 markus 1193: packet_put_int(nc->self);
1.149 markus 1194: packet_put_int(nc->local_window_max);
1195: packet_put_int(nc->local_maxpacket);
1.85 markus 1196: /* originator ipaddr and port */
1197: packet_put_cstring(remote_ipaddr);
1.57 markus 1198: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1199: debug2("ssh2 x11 bug compat mode");
1.57 markus 1200: } else {
1201: packet_put_int(remote_port);
1202: }
1.51 markus 1203: packet_send();
1204: } else {
1205: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1206: packet_put_int(nc->self);
1.121 markus 1207: if (packet_get_protocol_flags() &
1208: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1209: packet_put_cstring(buf);
1.51 markus 1210: packet_send();
1211: }
1.85 markus 1212: xfree(remote_ipaddr);
1.41 markus 1213: }
1214: }
1.25 markus 1215:
1.127 itojun 1216: static void
1.103 markus 1217: port_open_helper(Channel *c, char *rtype)
1218: {
1219: int direct;
1220: char buf[1024];
1221: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1222: int remote_port = get_peer_port(c->sock);
1.103 markus 1223:
1224: direct = (strcmp(rtype, "direct-tcpip") == 0);
1225:
1226: snprintf(buf, sizeof buf,
1227: "%s: listening port %d for %.100s port %d, "
1228: "connect from %.200s port %d",
1229: rtype, c->listening_port, c->path, c->host_port,
1230: remote_ipaddr, remote_port);
1231:
1232: xfree(c->remote_name);
1233: c->remote_name = xstrdup(buf);
1234:
1235: if (compat20) {
1236: packet_start(SSH2_MSG_CHANNEL_OPEN);
1237: packet_put_cstring(rtype);
1238: packet_put_int(c->self);
1239: packet_put_int(c->local_window_max);
1240: packet_put_int(c->local_maxpacket);
1241: if (direct) {
1242: /* target host, port */
1243: packet_put_cstring(c->path);
1244: packet_put_int(c->host_port);
1245: } else {
1246: /* listen address, port */
1247: packet_put_cstring(c->path);
1248: packet_put_int(c->listening_port);
1249: }
1250: /* originator host and port */
1251: packet_put_cstring(remote_ipaddr);
1.216 markus 1252: packet_put_int((u_int)remote_port);
1.103 markus 1253: packet_send();
1254: } else {
1255: packet_start(SSH_MSG_PORT_OPEN);
1256: packet_put_int(c->self);
1257: packet_put_cstring(c->path);
1258: packet_put_int(c->host_port);
1.121 markus 1259: if (packet_get_protocol_flags() &
1260: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1261: packet_put_cstring(c->remote_name);
1262: packet_send();
1263: }
1264: xfree(remote_ipaddr);
1265: }
1266:
1.226 djm 1267: static void
1268: channel_set_reuseaddr(int fd)
1269: {
1270: int on = 1;
1271:
1272: /*
1273: * Set socket options.
1274: * Allow local port reuse in TIME_WAIT.
1275: */
1276: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1277: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1278: }
1279:
1.41 markus 1280: /*
1281: * This socket is listening for connections to a forwarded TCP/IP port.
1282: */
1.127 itojun 1283: static void
1.237 deraadt 1284: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1285: {
1.103 markus 1286: Channel *nc;
1.41 markus 1287: struct sockaddr addr;
1.113 markus 1288: int newsock, nextstate;
1.41 markus 1289: socklen_t addrlen;
1.103 markus 1290: char *rtype;
1.73 markus 1291:
1.41 markus 1292: if (FD_ISSET(c->sock, readset)) {
1293: debug("Connection to port %d forwarding "
1294: "to %.100s port %d requested.",
1295: c->listening_port, c->path, c->host_port);
1.103 markus 1296:
1.137 markus 1297: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1298: nextstate = SSH_CHANNEL_OPENING;
1299: rtype = "forwarded-tcpip";
1300: } else {
1301: if (c->host_port == 0) {
1302: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1303: rtype = "dynamic-tcpip";
1.137 markus 1304: } else {
1305: nextstate = SSH_CHANNEL_OPENING;
1306: rtype = "direct-tcpip";
1307: }
1308: }
1.103 markus 1309:
1.41 markus 1310: addrlen = sizeof(addr);
1311: newsock = accept(c->sock, &addr, &addrlen);
1312: if (newsock < 0) {
1313: error("accept: %.100s", strerror(errno));
1314: return;
1315: }
1.169 stevesk 1316: set_nodelay(newsock);
1.190 markus 1317: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1318: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1319: nc->listening_port = c->listening_port;
1320: nc->host_port = c->host_port;
1321: strlcpy(nc->path, c->path, sizeof(nc->path));
1322:
1.137 markus 1323: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1324: /*
1325: * do not call the channel_post handler until
1326: * this flag has been reset by a pre-handler.
1327: * otherwise the FD_ISSET calls might overflow
1328: */
1329: nc->delayed = 1;
1330: } else {
1.103 markus 1331: port_open_helper(nc, rtype);
1.137 markus 1332: }
1.41 markus 1333: }
1334: }
1.25 markus 1335:
1.41 markus 1336: /*
1337: * This is the authentication agent socket listening for connections from
1338: * clients.
1339: */
1.127 itojun 1340: static void
1.237 deraadt 1341: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1342: {
1.113 markus 1343: Channel *nc;
1344: int newsock;
1.41 markus 1345: struct sockaddr addr;
1346: socklen_t addrlen;
1.25 markus 1347:
1.41 markus 1348: if (FD_ISSET(c->sock, readset)) {
1349: addrlen = sizeof(addr);
1350: newsock = accept(c->sock, &addr, &addrlen);
1351: if (newsock < 0) {
1352: error("accept from auth socket: %.100s", strerror(errno));
1353: return;
1354: }
1.113 markus 1355: nc = channel_new("accepted auth socket",
1.73 markus 1356: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1357: c->local_window_max, c->local_maxpacket,
1.190 markus 1358: 0, "accepted auth socket", 1);
1.73 markus 1359: if (compat20) {
1360: packet_start(SSH2_MSG_CHANNEL_OPEN);
1361: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1362: packet_put_int(nc->self);
1.73 markus 1363: packet_put_int(c->local_window_max);
1364: packet_put_int(c->local_maxpacket);
1365: } else {
1366: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1367: packet_put_int(nc->self);
1.73 markus 1368: }
1.41 markus 1369: packet_send();
1370: }
1371: }
1.25 markus 1372:
1.127 itojun 1373: static void
1.237 deraadt 1374: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1375: {
1.114 markus 1376: int err = 0;
1.129 stevesk 1377: socklen_t sz = sizeof(err);
1.114 markus 1378:
1.75 markus 1379: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1380: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1381: err = errno;
1382: error("getsockopt SO_ERROR failed");
1383: }
1384: if (err == 0) {
1385: debug("channel %d: connected", c->self);
1386: c->type = SSH_CHANNEL_OPEN;
1387: if (compat20) {
1388: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1389: packet_put_int(c->remote_id);
1390: packet_put_int(c->self);
1391: packet_put_int(c->local_window);
1392: packet_put_int(c->local_maxpacket);
1393: } else {
1394: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1395: packet_put_int(c->remote_id);
1396: packet_put_int(c->self);
1397: }
1.75 markus 1398: } else {
1.114 markus 1399: debug("channel %d: not connected: %s",
1400: c->self, strerror(err));
1401: if (compat20) {
1402: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1403: packet_put_int(c->remote_id);
1404: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1405: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1406: packet_put_cstring(strerror(err));
1407: packet_put_cstring("");
1408: }
1.75 markus 1409: } else {
1.114 markus 1410: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1411: packet_put_int(c->remote_id);
1.75 markus 1412: }
1.114 markus 1413: chan_mark_dead(c);
1.75 markus 1414: }
1.114 markus 1415: packet_send();
1.75 markus 1416: }
1417: }
1418:
1.127 itojun 1419: static int
1.237 deraadt 1420: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1421: {
1.214 markus 1422: char buf[CHAN_RBUF];
1.41 markus 1423: int len;
1.25 markus 1424:
1.118 markus 1425: if (c->rfd != -1 &&
1.41 markus 1426: FD_ISSET(c->rfd, readset)) {
1427: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1428: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1429: return 1;
1.41 markus 1430: if (len <= 0) {
1.194 markus 1431: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1432: c->self, c->rfd, len);
1.104 markus 1433: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1434: debug2("channel %d: not open", c->self);
1.113 markus 1435: chan_mark_dead(c);
1.103 markus 1436: return -1;
1.104 markus 1437: } else if (compat13) {
1.158 markus 1438: buffer_clear(&c->output);
1.41 markus 1439: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1440: debug2("channel %d: input draining.", c->self);
1.25 markus 1441: } else {
1.41 markus 1442: chan_read_failed(c);
1.25 markus 1443: }
1.41 markus 1444: return -1;
1445: }
1.143 deraadt 1446: if (c->input_filter != NULL) {
1.66 markus 1447: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1448: debug2("channel %d: filter stops", c->self);
1.65 markus 1449: chan_read_failed(c);
1450: }
1.228 reyk 1451: } else if (c->datagram) {
1452: buffer_put_string(&c->input, buf, len);
1.65 markus 1453: } else {
1454: buffer_append(&c->input, buf, len);
1455: }
1.41 markus 1456: }
1457: return 1;
1458: }
1.241 deraadt 1459:
1.127 itojun 1460: static int
1.237 deraadt 1461: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1462: {
1.95 markus 1463: struct termios tio;
1.231 reyk 1464: u_char *data = NULL, *buf;
1.134 markus 1465: u_int dlen;
1.41 markus 1466: int len;
1.25 markus 1467:
1.41 markus 1468: /* Send buffered output data to the socket. */
1.118 markus 1469: if (c->wfd != -1 &&
1.41 markus 1470: FD_ISSET(c->wfd, writeset) &&
1471: buffer_len(&c->output) > 0) {
1.231 reyk 1472: if (c->output_filter != NULL) {
1473: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1474: debug2("channel %d: filter stops", c->self);
1.232 reyk 1475: if (c->type != SSH_CHANNEL_OPEN)
1476: chan_mark_dead(c);
1477: else
1478: chan_write_failed(c);
1479: return -1;
1.231 reyk 1480: }
1481: } else if (c->datagram) {
1482: buf = data = buffer_get_string(&c->output, &dlen);
1483: } else {
1484: buf = data = buffer_ptr(&c->output);
1485: dlen = buffer_len(&c->output);
1486: }
1487:
1.228 reyk 1488: if (c->datagram) {
1489: /* ignore truncated writes, datagrams might get lost */
1490: c->local_consumed += dlen + 4;
1.231 reyk 1491: len = write(c->wfd, buf, dlen);
1.228 reyk 1492: xfree(data);
1493: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1494: return 1;
1495: if (len <= 0) {
1496: if (c->type != SSH_CHANNEL_OPEN)
1497: chan_mark_dead(c);
1498: else
1499: chan_write_failed(c);
1500: return -1;
1501: }
1502: return 1;
1503: }
1.231 reyk 1504:
1505: len = write(c->wfd, buf, dlen);
1.53 markus 1506: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1507: return 1;
1.41 markus 1508: if (len <= 0) {
1.104 markus 1509: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1510: debug2("channel %d: not open", c->self);
1.113 markus 1511: chan_mark_dead(c);
1.104 markus 1512: return -1;
1513: } else if (compat13) {
1.158 markus 1514: buffer_clear(&c->output);
1.194 markus 1515: debug2("channel %d: input draining.", c->self);
1.41 markus 1516: c->type = SSH_CHANNEL_INPUT_DRAINING;
1517: } else {
1518: chan_write_failed(c);
1519: }
1520: return -1;
1.91 markus 1521: }
1.231 reyk 1522: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1523: if (tcgetattr(c->wfd, &tio) == 0 &&
1524: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1525: /*
1526: * Simulate echo to reduce the impact of
1.96 markus 1527: * traffic analysis. We need to match the
1.95 markus 1528: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1529: * (4 byte channel id + buf)
1.91 markus 1530: */
1.95 markus 1531: packet_send_ignore(4 + len);
1.91 markus 1532: packet_send();
1533: }
1.25 markus 1534: }
1.41 markus 1535: buffer_consume(&c->output, len);
1.44 markus 1536: if (compat20 && len > 0) {
1537: c->local_consumed += len;
1538: }
1539: }
1540: return 1;
1541: }
1.241 deraadt 1542:
1.127 itojun 1543: static int
1.237 deraadt 1544: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1545: {
1.214 markus 1546: char buf[CHAN_RBUF];
1.44 markus 1547: int len;
1548:
1.45 markus 1549: /** XXX handle drain efd, too */
1.44 markus 1550: if (c->efd != -1) {
1551: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1552: FD_ISSET(c->efd, writeset) &&
1553: buffer_len(&c->extended) > 0) {
1554: len = write(c->efd, buffer_ptr(&c->extended),
1555: buffer_len(&c->extended));
1.70 markus 1556: debug2("channel %d: written %d to efd %d",
1.44 markus 1557: c->self, len, c->efd);
1.93 markus 1558: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1559: return 1;
1560: if (len <= 0) {
1561: debug2("channel %d: closing write-efd %d",
1562: c->self, c->efd);
1.132 markus 1563: channel_close_fd(&c->efd);
1.93 markus 1564: } else {
1.44 markus 1565: buffer_consume(&c->extended, len);
1566: c->local_consumed += len;
1567: }
1568: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1569: FD_ISSET(c->efd, readset)) {
1570: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1571: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1572: c->self, len, c->efd);
1.93 markus 1573: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1574: return 1;
1575: if (len <= 0) {
1576: debug2("channel %d: closing read-efd %d",
1.45 markus 1577: c->self, c->efd);
1.132 markus 1578: channel_close_fd(&c->efd);
1.93 markus 1579: } else {
1.44 markus 1580: buffer_append(&c->extended, buf, len);
1.93 markus 1581: }
1.44 markus 1582: }
1583: }
1584: return 1;
1585: }
1.241 deraadt 1586:
1.127 itojun 1587: static int
1.237 deraadt 1588: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1589: {
1590: char buf[16];
1591: int len;
1592:
1593: /* Monitor control fd to detect if the slave client exits */
1594: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1595: len = read(c->ctl_fd, buf, sizeof(buf));
1596: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1597: return 1;
1598: if (len <= 0) {
1599: debug2("channel %d: ctl read<=0", c->self);
1600: if (c->type != SSH_CHANNEL_OPEN) {
1601: debug2("channel %d: not open", c->self);
1602: chan_mark_dead(c);
1603: return -1;
1604: } else {
1605: chan_read_failed(c);
1606: chan_write_failed(c);
1607: }
1608: return -1;
1609: } else
1610: fatal("%s: unexpected data on ctl fd", __func__);
1611: }
1612: return 1;
1613: }
1.241 deraadt 1614:
1.204 djm 1615: static int
1.93 markus 1616: channel_check_window(Channel *c)
1.44 markus 1617: {
1.104 markus 1618: if (c->type == SSH_CHANNEL_OPEN &&
1619: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1620: c->local_window < c->local_window_max/2 &&
1621: c->local_consumed > 0) {
1622: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1623: packet_put_int(c->remote_id);
1624: packet_put_int(c->local_consumed);
1625: packet_send();
1.70 markus 1626: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1627: c->self, c->local_window,
1628: c->local_consumed);
1629: c->local_window += c->local_consumed;
1630: c->local_consumed = 0;
1.1 deraadt 1631: }
1.41 markus 1632: return 1;
1.1 deraadt 1633: }
1634:
1.127 itojun 1635: static void
1.237 deraadt 1636: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1637: {
1.137 markus 1638: if (c->delayed)
1639: return;
1.41 markus 1640: channel_handle_rfd(c, readset, writeset);
1641: channel_handle_wfd(c, readset, writeset);
1.157 markus 1642: if (!compat20)
1.137 markus 1643: return;
1.44 markus 1644: channel_handle_efd(c, readset, writeset);
1.204 djm 1645: channel_handle_ctl(c, readset, writeset);
1.93 markus 1646: channel_check_window(c);
1.44 markus 1647: }
1648:
1.127 itojun 1649: static void
1.237 deraadt 1650: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1651: {
1.41 markus 1652: int len;
1.180 deraadt 1653:
1.41 markus 1654: /* Send buffered output data to the socket. */
1655: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1656: len = write(c->sock, buffer_ptr(&c->output),
1657: buffer_len(&c->output));
1658: if (len <= 0)
1.158 markus 1659: buffer_clear(&c->output);
1.41 markus 1660: else
1661: buffer_consume(&c->output, len);
1662: }
1663: }
1.25 markus 1664:
1.127 itojun 1665: static void
1.44 markus 1666: channel_handler_init_20(void)
1667: {
1.157 markus 1668: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1669: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1670: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1671: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1672: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1673: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1674: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1675: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1676:
1.157 markus 1677: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1678: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1679: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1680: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1681: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1682: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1683: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1684: }
1685:
1.127 itojun 1686: static void
1.41 markus 1687: channel_handler_init_13(void)
1688: {
1689: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1690: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1691: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1692: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1693: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1694: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1695: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1696: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1697: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1698:
1.157 markus 1699: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1700: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1701: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1702: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1703: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1704: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1705: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1706: }
1.25 markus 1707:
1.127 itojun 1708: static void
1.41 markus 1709: channel_handler_init_15(void)
1710: {
1.157 markus 1711: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1712: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1713: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1714: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1715: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1716: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1717: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1718:
1.41 markus 1719: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1720: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1721: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1722: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1723: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1724: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1725: }
1.27 markus 1726:
1.127 itojun 1727: static void
1.41 markus 1728: channel_handler_init(void)
1729: {
1730: int i;
1.180 deraadt 1731:
1.148 deraadt 1732: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1733: channel_pre[i] = NULL;
1734: channel_post[i] = NULL;
1735: }
1.44 markus 1736: if (compat20)
1737: channel_handler_init_20();
1738: else if (compat13)
1.41 markus 1739: channel_handler_init_13();
1740: else
1741: channel_handler_init_15();
1742: }
1.25 markus 1743:
1.140 markus 1744: /* gc dead channels */
1745: static void
1746: channel_garbage_collect(Channel *c)
1747: {
1748: if (c == NULL)
1749: return;
1750: if (c->detach_user != NULL) {
1.225 djm 1751: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1752: return;
1.194 markus 1753: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1754: c->detach_user(c->self, NULL);
1755: /* if we still have a callback */
1756: if (c->detach_user != NULL)
1757: return;
1.194 markus 1758: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1759: }
1760: if (!chan_is_dead(c, 1))
1761: return;
1.194 markus 1762: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1763: channel_free(c);
1764: }
1765:
1.127 itojun 1766: static void
1.237 deraadt 1767: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1768: {
1769: static int did_init = 0;
1.209 avsm 1770: u_int i;
1.41 markus 1771: Channel *c;
1.25 markus 1772:
1.41 markus 1773: if (!did_init) {
1774: channel_handler_init();
1775: did_init = 1;
1776: }
1777: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1778: c = channels[i];
1779: if (c == NULL)
1.41 markus 1780: continue;
1.118 markus 1781: if (ftab[c->type] != NULL)
1782: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1783: channel_garbage_collect(c);
1.1 deraadt 1784: }
1785: }
1786:
1.121 markus 1787: /*
1788: * Allocate/update select bitmasks and add any bits relevant to channels in
1789: * select bitmasks.
1790: */
1.49 markus 1791: void
1.100 markus 1792: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1793: u_int *nallocp, int rekeying)
1.41 markus 1794: {
1.243 djm 1795: u_int n, sz, nfdset;
1.84 markus 1796:
1797: n = MAX(*maxfdp, channel_max_fd);
1798:
1.243 djm 1799: nfdset = howmany(n+1, NFDBITS);
1800: /* Explicitly test here, because xrealloc isn't always called */
1801: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1802: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1803: sz = nfdset * sizeof(fd_mask);
1804:
1.132 markus 1805: /* perhaps check sz < nalloc/2 and shrink? */
1806: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1807: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1808: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1809: *nallocp = sz;
1.84 markus 1810: }
1.132 markus 1811: *maxfdp = n;
1.84 markus 1812: memset(*readsetp, 0, sz);
1813: memset(*writesetp, 0, sz);
1814:
1.100 markus 1815: if (!rekeying)
1816: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1817: }
1818:
1.121 markus 1819: /*
1820: * After select, perform any appropriate operations for channels which have
1821: * events pending.
1822: */
1.49 markus 1823: void
1.237 deraadt 1824: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1825: {
1826: channel_handler(channel_post, readset, writeset);
1827: }
1828:
1.121 markus 1829:
1.84 markus 1830: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1831: void
1.142 itojun 1832: channel_output_poll(void)
1.1 deraadt 1833: {
1.41 markus 1834: Channel *c;
1.209 avsm 1835: u_int i, len;
1.1 deraadt 1836:
1.25 markus 1837: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1838: c = channels[i];
1839: if (c == NULL)
1840: continue;
1.37 markus 1841:
1.121 markus 1842: /*
1843: * We are only interested in channels that can have buffered
1844: * incoming data.
1845: */
1.37 markus 1846: if (compat13) {
1.41 markus 1847: if (c->type != SSH_CHANNEL_OPEN &&
1848: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1849: continue;
1850: } else {
1.41 markus 1851: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1852: continue;
1853: }
1.46 markus 1854: if (compat20 &&
1855: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1856: /* XXX is this true? */
1.140 markus 1857: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1858: continue;
1859: }
1.25 markus 1860:
1861: /* Get the amount of buffered data for this channel. */
1.93 markus 1862: if ((c->istate == CHAN_INPUT_OPEN ||
1863: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1864: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1865: if (c->datagram) {
1866: if (len > 0) {
1867: u_char *data;
1868: u_int dlen;
1869:
1870: data = buffer_get_string(&c->input,
1871: &dlen);
1872: packet_start(SSH2_MSG_CHANNEL_DATA);
1873: packet_put_int(c->remote_id);
1874: packet_put_string(data, dlen);
1875: packet_send();
1876: c->remote_window -= dlen + 4;
1877: xfree(data);
1878: }
1879: continue;
1880: }
1.121 markus 1881: /*
1882: * Send some data for the other side over the secure
1883: * connection.
1884: */
1.44 markus 1885: if (compat20) {
1886: if (len > c->remote_window)
1887: len = c->remote_window;
1888: if (len > c->remote_maxpacket)
1889: len = c->remote_maxpacket;
1.25 markus 1890: } else {
1.44 markus 1891: if (packet_is_interactive()) {
1892: if (len > 1024)
1893: len = 512;
1894: } else {
1895: /* Keep the packets at reasonable size. */
1896: if (len > packet_get_maxsize()/2)
1897: len = packet_get_maxsize()/2;
1898: }
1.25 markus 1899: }
1.41 markus 1900: if (len > 0) {
1.44 markus 1901: packet_start(compat20 ?
1902: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1903: packet_put_int(c->remote_id);
1904: packet_put_string(buffer_ptr(&c->input), len);
1905: packet_send();
1906: buffer_consume(&c->input, len);
1907: c->remote_window -= len;
1908: }
1909: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1910: if (compat13)
1911: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1912: /*
1913: * input-buffer is empty and read-socket shutdown:
1.172 markus 1914: * tell peer, that we will not send more data: send IEOF.
1915: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1916: */
1.172 markus 1917: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1918: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1919: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1920: else
1921: chan_ibuf_empty(c);
1.25 markus 1922: }
1.44 markus 1923: /* Send extended data, i.e. stderr */
1924: if (compat20 &&
1.172 markus 1925: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1926: c->remote_window > 0 &&
1927: (len = buffer_len(&c->extended)) > 0 &&
1928: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1929: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1930: c->self, c->remote_window, buffer_len(&c->extended),
1931: c->extended_usage);
1.44 markus 1932: if (len > c->remote_window)
1933: len = c->remote_window;
1934: if (len > c->remote_maxpacket)
1935: len = c->remote_maxpacket;
1936: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1937: packet_put_int(c->remote_id);
1938: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1939: packet_put_string(buffer_ptr(&c->extended), len);
1940: packet_send();
1941: buffer_consume(&c->extended, len);
1942: c->remote_window -= len;
1.93 markus 1943: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1944: }
1.25 markus 1945: }
1.1 deraadt 1946: }
1947:
1.121 markus 1948:
1949: /* -- protocol input */
1.249 djm 1950:
1951: /* ARGSUSED */
1.49 markus 1952: void
1.154 markus 1953: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1954: {
1.37 markus 1955: int id;
1.25 markus 1956: char *data;
1.77 markus 1957: u_int data_len;
1.41 markus 1958: Channel *c;
1.25 markus 1959:
1960: /* Get the channel number and verify it. */
1.37 markus 1961: id = packet_get_int();
1.41 markus 1962: c = channel_lookup(id);
1963: if (c == NULL)
1.37 markus 1964: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1965:
1966: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1967: if (c->type != SSH_CHANNEL_OPEN &&
1968: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1969: return;
1970:
1.25 markus 1971: /* Get the data. */
1972: data = packet_get_string(&data_len);
1.200 markus 1973:
1974: /*
1975: * Ignore data for protocol > 1.3 if output end is no longer open.
1976: * For protocol 2 the sending side is reducing its window as it sends
1977: * data, so we must 'fake' consumption of the data in order to ensure
1978: * that window updates are sent back. Otherwise the connection might
1979: * deadlock.
1980: */
1981: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1982: if (compat20) {
1983: c->local_window -= data_len;
1984: c->local_consumed += data_len;
1985: }
1986: xfree(data);
1987: return;
1988: }
1.41 markus 1989:
1.143 deraadt 1990: if (compat20) {
1.44 markus 1991: if (data_len > c->local_maxpacket) {
1.188 itojun 1992: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1993: c->self, data_len, c->local_maxpacket);
1994: }
1995: if (data_len > c->local_window) {
1.188 itojun 1996: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1997: c->self, data_len, c->local_window);
1998: xfree(data);
1999: return;
2000: }
2001: c->local_window -= data_len;
2002: }
1.152 markus 2003: packet_check_eom();
1.228 reyk 2004: if (c->datagram)
2005: buffer_put_string(&c->output, data, data_len);
2006: else
2007: buffer_append(&c->output, data, data_len);
1.25 markus 2008: xfree(data);
1.1 deraadt 2009: }
1.121 markus 2010:
1.249 djm 2011: /* ARGSUSED */
1.49 markus 2012: void
1.154 markus 2013: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2014: {
2015: int id;
2016: char *data;
1.177 markus 2017: u_int data_len, tcode;
1.44 markus 2018: Channel *c;
2019:
2020: /* Get the channel number and verify it. */
2021: id = packet_get_int();
2022: c = channel_lookup(id);
2023:
2024: if (c == NULL)
2025: packet_disconnect("Received extended_data for bad channel %d.", id);
2026: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2027: logit("channel %d: ext data for non open", id);
1.44 markus 2028: return;
1.172 markus 2029: }
2030: if (c->flags & CHAN_EOF_RCVD) {
2031: if (datafellows & SSH_BUG_EXTEOF)
2032: debug("channel %d: accepting ext data after eof", id);
2033: else
2034: packet_disconnect("Received extended_data after EOF "
2035: "on channel %d.", id);
1.44 markus 2036: }
2037: tcode = packet_get_int();
2038: if (c->efd == -1 ||
2039: c->extended_usage != CHAN_EXTENDED_WRITE ||
2040: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2041: logit("channel %d: bad ext data", c->self);
1.44 markus 2042: return;
2043: }
2044: data = packet_get_string(&data_len);
1.152 markus 2045: packet_check_eom();
1.44 markus 2046: if (data_len > c->local_window) {
1.188 itojun 2047: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2048: c->self, data_len, c->local_window);
2049: xfree(data);
2050: return;
2051: }
1.70 markus 2052: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2053: c->local_window -= data_len;
2054: buffer_append(&c->extended, data, data_len);
2055: xfree(data);
2056: }
2057:
1.249 djm 2058: /* ARGSUSED */
1.49 markus 2059: void
1.154 markus 2060: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2061: {
2062: int id;
2063: Channel *c;
2064:
2065: id = packet_get_int();
1.152 markus 2066: packet_check_eom();
1.41 markus 2067: c = channel_lookup(id);
2068: if (c == NULL)
2069: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2070: chan_rcvd_ieof(c);
1.133 markus 2071:
2072: /* XXX force input close */
1.156 markus 2073: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2074: debug("channel %d: FORCE input drain", c->self);
2075: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2076: if (buffer_len(&c->input) == 0)
2077: chan_ibuf_empty(c);
1.133 markus 2078: }
2079:
1.41 markus 2080: }
1.1 deraadt 2081:
1.249 djm 2082: /* ARGSUSED */
1.49 markus 2083: void
1.154 markus 2084: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2085: {
1.41 markus 2086: int id;
2087: Channel *c;
1.1 deraadt 2088:
1.41 markus 2089: id = packet_get_int();
1.152 markus 2090: packet_check_eom();
1.41 markus 2091: c = channel_lookup(id);
2092: if (c == NULL)
2093: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2094:
2095: /*
2096: * Send a confirmation that we have closed the channel and no more
2097: * data is coming for it.
2098: */
1.25 markus 2099: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2100: packet_put_int(c->remote_id);
1.25 markus 2101: packet_send();
2102:
1.27 markus 2103: /*
2104: * If the channel is in closed state, we have sent a close request,
2105: * and the other side will eventually respond with a confirmation.
2106: * Thus, we cannot free the channel here, because then there would be
2107: * no-one to receive the confirmation. The channel gets freed when
2108: * the confirmation arrives.
2109: */
1.41 markus 2110: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2111: /*
2112: * Not a closed channel - mark it as draining, which will
2113: * cause it to be freed later.
2114: */
1.158 markus 2115: buffer_clear(&c->input);
1.41 markus 2116: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2117: }
1.1 deraadt 2118: }
2119:
1.41 markus 2120: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2121: /* ARGSUSED */
1.49 markus 2122: void
1.154 markus 2123: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2124: {
2125: int id = packet_get_int();
2126: Channel *c = channel_lookup(id);
1.151 markus 2127:
1.152 markus 2128: packet_check_eom();
1.41 markus 2129: if (c == NULL)
2130: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2131: chan_rcvd_oclose(c);
2132: }
1.1 deraadt 2133:
1.249 djm 2134: /* ARGSUSED */
1.49 markus 2135: void
1.154 markus 2136: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2137: {
1.41 markus 2138: int id = packet_get_int();
2139: Channel *c = channel_lookup(id);
1.1 deraadt 2140:
1.152 markus 2141: packet_check_eom();
1.41 markus 2142: if (c == NULL)
2143: packet_disconnect("Received close confirmation for "
2144: "out-of-range channel %d.", id);
2145: if (c->type != SSH_CHANNEL_CLOSED)
2146: packet_disconnect("Received close confirmation for "
2147: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2148: channel_free(c);
1.1 deraadt 2149: }
2150:
1.249 djm 2151: /* ARGSUSED */
1.49 markus 2152: void
1.154 markus 2153: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2154: {
1.41 markus 2155: int id, remote_id;
2156: Channel *c;
1.1 deraadt 2157:
1.41 markus 2158: id = packet_get_int();
2159: c = channel_lookup(id);
1.25 markus 2160:
1.41 markus 2161: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2162: packet_disconnect("Received open confirmation for "
2163: "non-opening channel %d.", id);
2164: remote_id = packet_get_int();
1.27 markus 2165: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2166: c->remote_id = remote_id;
2167: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2168:
2169: if (compat20) {
2170: c->remote_window = packet_get_int();
2171: c->remote_maxpacket = packet_get_int();
1.165 markus 2172: if (c->confirm) {
1.70 markus 2173: debug2("callback start");
1.204 djm 2174: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2175: debug2("callback done");
1.44 markus 2176: }
1.194 markus 2177: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2178: c->remote_window, c->remote_maxpacket);
2179: }
1.152 markus 2180: packet_check_eom();
1.1 deraadt 2181: }
2182:
1.127 itojun 2183: static char *
1.114 markus 2184: reason2txt(int reason)
2185: {
1.143 deraadt 2186: switch (reason) {
1.114 markus 2187: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2188: return "administratively prohibited";
2189: case SSH2_OPEN_CONNECT_FAILED:
2190: return "connect failed";
2191: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2192: return "unknown channel type";
2193: case SSH2_OPEN_RESOURCE_SHORTAGE:
2194: return "resource shortage";
2195: }
1.117 stevesk 2196: return "unknown reason";
1.114 markus 2197: }
2198:
1.249 djm 2199: /* ARGSUSED */
1.49 markus 2200: void
1.154 markus 2201: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2202: {
1.86 markus 2203: int id, reason;
2204: char *msg = NULL, *lang = NULL;
1.41 markus 2205: Channel *c;
2206:
2207: id = packet_get_int();
2208: c = channel_lookup(id);
1.25 markus 2209:
1.41 markus 2210: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2211: packet_disconnect("Received open failure for "
2212: "non-opening channel %d.", id);
1.44 markus 2213: if (compat20) {
1.86 markus 2214: reason = packet_get_int();
1.110 markus 2215: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2216: msg = packet_get_string(NULL);
2217: lang = packet_get_string(NULL);
2218: }
1.188 itojun 2219: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2220: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2221: if (msg != NULL)
2222: xfree(msg);
2223: if (lang != NULL)
2224: xfree(lang);
1.44 markus 2225: }
1.152 markus 2226: packet_check_eom();
1.25 markus 2227: /* Free the channel. This will also close the socket. */
1.113 markus 2228: channel_free(c);
1.44 markus 2229: }
2230:
1.249 djm 2231: /* ARGSUSED */
1.121 markus 2232: void
1.154 markus 2233: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2234: {
2235: Channel *c;
1.178 markus 2236: int id;
2237: u_int adjust;
1.121 markus 2238:
2239: if (!compat20)
2240: return;
2241:
2242: /* Get the channel number and verify it. */
2243: id = packet_get_int();
2244: c = channel_lookup(id);
1.1 deraadt 2245:
1.229 markus 2246: if (c == NULL) {
2247: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2248: return;
2249: }
2250: adjust = packet_get_int();
1.152 markus 2251: packet_check_eom();
1.178 markus 2252: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2253: c->remote_window += adjust;
2254: }
1.1 deraadt 2255:
1.249 djm 2256: /* ARGSUSED */
1.121 markus 2257: void
1.154 markus 2258: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2259: {
1.121 markus 2260: Channel *c = NULL;
2261: u_short host_port;
2262: char *host, *originator_string;
2263: int remote_id, sock = -1;
2264:
2265: remote_id = packet_get_int();
2266: host = packet_get_string(NULL);
2267: host_port = packet_get_int();
1.25 markus 2268:
1.121 markus 2269: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2270: originator_string = packet_get_string(NULL);
2271: } else {
2272: originator_string = xstrdup("unknown (remote did not supply name)");
2273: }
1.152 markus 2274: packet_check_eom();
1.121 markus 2275: sock = channel_connect_to(host, host_port);
2276: if (sock != -1) {
2277: c = channel_new("connected socket",
2278: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2279: originator_string, 1);
1.167 markus 2280: c->remote_id = remote_id;
1.25 markus 2281: }
1.190 markus 2282: xfree(originator_string);
1.121 markus 2283: if (c == NULL) {
2284: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2285: packet_put_int(remote_id);
2286: packet_send();
2287: }
2288: xfree(host);
1.1 deraadt 2289: }
2290:
1.121 markus 2291:
2292: /* -- tcp forwarding */
1.135 markus 2293:
2294: void
2295: channel_set_af(int af)
2296: {
2297: IPv4or6 = af;
2298: }
1.121 markus 2299:
1.160 markus 2300: static int
2301: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2302: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2303: {
1.113 markus 2304: Channel *c;
1.226 djm 2305: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2306: struct addrinfo hints, *ai, *aitop;
1.212 djm 2307: const char *host, *addr;
1.35 markus 2308: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2309:
1.160 markus 2310: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2311: listen_addr : host_to_connect;
1.212 djm 2312: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2313:
1.160 markus 2314: if (host == NULL) {
2315: error("No forward host name.");
1.218 markus 2316: return 0;
1.73 markus 2317: }
1.113 markus 2318: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2319: error("Forward host name too long.");
1.218 markus 2320: return 0;
1.87 markus 2321: }
1.25 markus 2322:
1.28 markus 2323: /*
1.212 djm 2324: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2325: * specified address or wildcard. On the client, a specified bind
2326: * address will always override gateway_ports. On the server, a
2327: * gateway_ports of 1 (``yes'') will override the client's
2328: * specification and force a wildcard bind, whereas a value of 2
2329: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2330: * asked for.
2331: *
2332: * Special-case listen_addrs are:
2333: *
2334: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2335: * "" (empty string), "*" -> wildcard v4/v6
2336: * "localhost" -> loopback v4/v6
2337: */
2338: addr = NULL;
2339: if (listen_addr == NULL) {
2340: /* No address specified: default to gateway_ports setting */
2341: if (gateway_ports)
2342: wildcard = 1;
2343: } else if (gateway_ports || is_client) {
2344: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2345: strcmp(listen_addr, "0.0.0.0") == 0) ||
2346: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2347: (!is_client && gateway_ports == 1))
2348: wildcard = 1;
2349: else if (strcmp(listen_addr, "localhost") != 0)
2350: addr = listen_addr;
2351: }
2352:
2353: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2354: type, wildcard, (addr == NULL) ? "NULL" : addr);
2355:
2356: /*
1.35 markus 2357: * getaddrinfo returns a loopback address if the hostname is
2358: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2359: */
1.35 markus 2360: memset(&hints, 0, sizeof(hints));
2361: hints.ai_family = IPv4or6;
1.212 djm 2362: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2363: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2364: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2365: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2366: if (addr == NULL) {
2367: /* This really shouldn't happen */
2368: packet_disconnect("getaddrinfo: fatal error: %s",
2369: gai_strerror(r));
2370: } else {
1.218 markus 2371: error("channel_setup_fwd_listener: "
1.212 djm 2372: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2373: }
1.218 markus 2374: return 0;
1.212 djm 2375: }
1.35 markus 2376:
2377: for (ai = aitop; ai; ai = ai->ai_next) {
2378: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2379: continue;
2380: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2381: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2382: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2383: continue;
2384: }
2385: /* Create a port to listen for the host. */
1.189 markus 2386: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2387: if (sock < 0) {
2388: /* this is no error since kernel may not support ipv6 */
2389: verbose("socket: %.100s", strerror(errno));
2390: continue;
2391: }
1.226 djm 2392:
2393: channel_set_reuseaddr(sock);
1.182 stevesk 2394:
1.35 markus 2395: debug("Local forwarding listening on %s port %s.", ntop, strport);
2396:
2397: /* Bind the socket to the address. */
2398: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2399: /* address can be in use ipv6 address is already bound */
2400: verbose("bind: %.100s", strerror(errno));
2401: close(sock);
2402: continue;
2403: }
2404: /* Start listening for connections on the socket. */
1.199 markus 2405: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2406: error("listen: %.100s", strerror(errno));
2407: close(sock);
2408: continue;
2409: }
2410: /* Allocate a channel number for the socket. */
1.121 markus 2411: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2412: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2413: 0, "port listener", 1);
1.113 markus 2414: strlcpy(c->path, host, sizeof(c->path));
2415: c->host_port = port_to_connect;
2416: c->listening_port = listen_port;
1.35 markus 2417: success = 1;
2418: }
2419: if (success == 0)
1.160 markus 2420: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2421: listen_port);
1.35 markus 2422: freeaddrinfo(aitop);
1.87 markus 2423: return success;
1.25 markus 2424: }
1.1 deraadt 2425:
1.202 djm 2426: int
2427: channel_cancel_rport_listener(const char *host, u_short port)
2428: {
1.209 avsm 2429: u_int i;
2430: int found = 0;
1.202 djm 2431:
1.213 deraadt 2432: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2433: Channel *c = channels[i];
2434:
2435: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2436: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2437: c->listening_port == port) {
1.210 djm 2438: debug2("%s: close channel %d", __func__, i);
1.202 djm 2439: channel_free(c);
2440: found = 1;
2441: }
2442: }
2443:
2444: return (found);
2445: }
2446:
1.160 markus 2447: /* protocol local port fwd, used by ssh (and sshd in v1) */
2448: int
1.212 djm 2449: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2450: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2451: {
2452: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2453: listen_host, listen_port, host_to_connect, port_to_connect,
2454: gateway_ports);
1.160 markus 2455: }
2456:
2457: /* protocol v2 remote port fwd, used by sshd */
2458: int
2459: channel_setup_remote_fwd_listener(const char *listen_address,
2460: u_short listen_port, int gateway_ports)
2461: {
2462: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2463: listen_address, listen_port, NULL, 0, gateway_ports);
2464: }
2465:
1.27 markus 2466: /*
2467: * Initiate forwarding of connections to port "port" on remote host through
2468: * the secure channel to host:port from local side.
2469: */
1.1 deraadt 2470:
1.253 markus 2471: int
1.212 djm 2472: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2473: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2474: {
1.153 markus 2475: int type, success = 0;
1.73 markus 2476:
1.25 markus 2477: /* Record locally that connection to this host/port is permitted. */
2478: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2479: fatal("channel_request_remote_forwarding: too many forwards");
2480:
2481: /* Send the forward request to the remote side. */
1.44 markus 2482: if (compat20) {
1.212 djm 2483: const char *address_to_bind;
2484: if (listen_host == NULL)
2485: address_to_bind = "localhost";
2486: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2487: address_to_bind = "";
2488: else
2489: address_to_bind = listen_host;
2490:
1.44 markus 2491: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2492: packet_put_cstring("tcpip-forward");
1.173 markus 2493: packet_put_char(1); /* boolean: want reply */
1.44 markus 2494: packet_put_cstring(address_to_bind);
2495: packet_put_int(listen_port);
1.73 markus 2496: packet_send();
2497: packet_write_wait();
2498: /* Assume that server accepts the request */
2499: success = 1;
1.44 markus 2500: } else {
2501: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2502: packet_put_int(listen_port);
2503: packet_put_cstring(host_to_connect);
1.44 markus 2504: packet_put_int(port_to_connect);
2505: packet_send();
2506: packet_write_wait();
1.73 markus 2507:
2508: /* Wait for response from the remote side. */
1.153 markus 2509: type = packet_read();
1.73 markus 2510: switch (type) {
2511: case SSH_SMSG_SUCCESS:
2512: success = 1;
2513: break;
2514: case SSH_SMSG_FAILURE:
2515: break;
2516: default:
2517: /* Unknown packet */
2518: packet_disconnect("Protocol error for port forward request:"
2519: "received packet type %d.", type);
2520: }
2521: }
2522: if (success) {
2523: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2524: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2525: permitted_opens[num_permitted_opens].listen_port = listen_port;
2526: num_permitted_opens++;
1.44 markus 2527: }
1.253 markus 2528: return (success ? 0 : -1);
1.1 deraadt 2529: }
2530:
1.27 markus 2531: /*
1.208 deraadt 2532: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2533: * local side.
2534: */
2535: void
1.212 djm 2536: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2537: {
2538: int i;
2539:
2540: if (!compat20)
2541: return;
2542:
2543: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2544: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2545: permitted_opens[i].listen_port == port)
2546: break;
2547: }
2548: if (i >= num_permitted_opens) {
2549: debug("%s: requested forward not found", __func__);
2550: return;
2551: }
2552: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2553: packet_put_cstring("cancel-tcpip-forward");
2554: packet_put_char(0);
1.212 djm 2555: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2556: packet_put_int(port);
2557: packet_send();
2558:
2559: permitted_opens[i].listen_port = 0;
2560: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2561: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2562: permitted_opens[i].host_to_connect = NULL;
2563: }
2564:
2565: /*
1.27 markus 2566: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2567: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2568: * message if there was an error).
1.27 markus 2569: */
1.253 markus 2570: int
1.56 markus 2571: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2572: {
1.31 markus 2573: u_short port, host_port;
1.253 markus 2574: int success = 0;
1.25 markus 2575: char *hostname;
1.1 deraadt 2576:
1.25 markus 2577: /* Get arguments from the packet. */
2578: port = packet_get_int();
2579: hostname = packet_get_string(NULL);
2580: host_port = packet_get_int();
2581:
1.27 markus 2582: /*
2583: * Check that an unprivileged user is not trying to forward a
2584: * privileged port.
2585: */
1.25 markus 2586: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2587: packet_disconnect(
2588: "Requested forwarding of port %d but user is not root.",
2589: port);
2590: if (host_port == 0)
2591: packet_disconnect("Dynamic forwarding denied.");
2592:
1.73 markus 2593: /* Initiate forwarding */
1.253 markus 2594: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2595: host_port, gateway_ports);
1.25 markus 2596:
2597: /* Free the argument string. */
2598: xfree(hostname);
1.253 markus 2599:
2600: return (success ? 0 : -1);
1.1 deraadt 2601: }
2602:
1.99 markus 2603: /*
2604: * Permits opening to any host/port if permitted_opens[] is empty. This is
2605: * usually called by the server, because the user could connect to any port
2606: * anyway, and the server has no way to know but to trust the client anyway.
2607: */
2608: void
1.142 itojun 2609: channel_permit_all_opens(void)
1.99 markus 2610: {
2611: if (num_permitted_opens == 0)
2612: all_opens_permitted = 1;
2613: }
2614:
1.101 markus 2615: void
1.99 markus 2616: channel_add_permitted_opens(char *host, int port)
2617: {
2618: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1.253 markus 2619: fatal("channel_add_permitted_opens: too many forwards");
1.99 markus 2620: debug("allow port forwarding to host %s port %d", host, port);
2621:
2622: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2623: permitted_opens[num_permitted_opens].port_to_connect = port;
2624: num_permitted_opens++;
2625:
2626: all_opens_permitted = 0;
2627: }
2628:
1.101 markus 2629: void
1.99 markus 2630: channel_clear_permitted_opens(void)
2631: {
2632: int i;
2633:
2634: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2635: if (permitted_opens[i].host_to_connect != NULL)
2636: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2637: num_permitted_opens = 0;
2638:
2639: }
2640:
2641: /* return socket to remote host, port */
1.127 itojun 2642: static int
1.99 markus 2643: connect_to(const char *host, u_short port)
1.41 markus 2644: {
2645: struct addrinfo hints, *ai, *aitop;
2646: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2647: int gaierr;
2648: int sock = -1;
2649:
2650: memset(&hints, 0, sizeof(hints));
2651: hints.ai_family = IPv4or6;
2652: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2653: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2654: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2655: error("connect_to %.100s: unknown host (%s)", host,
2656: gai_strerror(gaierr));
1.41 markus 2657: return -1;
2658: }
2659: for (ai = aitop; ai; ai = ai->ai_next) {
2660: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2661: continue;
2662: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2663: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2664: error("connect_to: getnameinfo failed");
1.41 markus 2665: continue;
2666: }
1.189 markus 2667: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2668: if (sock < 0) {
1.186 djm 2669: if (ai->ai_next == NULL)
2670: error("socket: %.100s", strerror(errno));
2671: else
2672: verbose("socket: %.100s", strerror(errno));
1.41 markus 2673: continue;
2674: }
1.205 djm 2675: if (set_nonblock(sock) == -1)
2676: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2677: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2678: errno != EINPROGRESS) {
1.99 markus 2679: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2680: strerror(errno));
2681: close(sock);
1.89 stevesk 2682: continue; /* fail -- try next */
1.41 markus 2683: }
2684: break; /* success */
2685:
2686: }
2687: freeaddrinfo(aitop);
2688: if (!ai) {
1.99 markus 2689: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2690: return -1;
2691: }
2692: /* success */
1.169 stevesk 2693: set_nodelay(sock);
1.41 markus 2694: return sock;
2695: }
1.99 markus 2696:
1.73 markus 2697: int
1.130 stevesk 2698: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2699: {
2700: int i;
1.99 markus 2701:
1.73 markus 2702: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2703: if (permitted_opens[i].host_to_connect != NULL &&
2704: permitted_opens[i].listen_port == listen_port)
1.99 markus 2705: return connect_to(
1.73 markus 2706: permitted_opens[i].host_to_connect,
2707: permitted_opens[i].port_to_connect);
1.74 markus 2708: error("WARNING: Server requests forwarding for unknown listen_port %d",
2709: listen_port);
1.73 markus 2710: return -1;
2711: }
2712:
1.99 markus 2713: /* Check if connecting to that port is permitted and connect. */
2714: int
2715: channel_connect_to(const char *host, u_short port)
2716: {
2717: int i, permit;
2718:
2719: permit = all_opens_permitted;
2720: if (!permit) {
2721: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2722: if (permitted_opens[i].host_to_connect != NULL &&
2723: permitted_opens[i].port_to_connect == port &&
1.99 markus 2724: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2725: permit = 1;
2726:
2727: }
2728: if (!permit) {
1.188 itojun 2729: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2730: "but the request was denied.", host, port);
2731: return -1;
2732: }
2733: return connect_to(host, port);
1.204 djm 2734: }
2735:
2736: void
2737: channel_send_window_changes(void)
2738: {
1.209 avsm 2739: u_int i;
1.204 djm 2740: struct winsize ws;
2741:
2742: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2743: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2744: channels[i]->type != SSH_CHANNEL_OPEN)
2745: continue;
2746: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2747: continue;
2748: channel_request_start(i, "window-change", 0);
1.238 deraadt 2749: packet_put_int((u_int)ws.ws_col);
2750: packet_put_int((u_int)ws.ws_row);
2751: packet_put_int((u_int)ws.ws_xpixel);
2752: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2753: packet_send();
2754: }
1.99 markus 2755: }
2756:
1.121 markus 2757: /* -- X11 forwarding */
1.1 deraadt 2758:
1.27 markus 2759: /*
2760: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2761: * Returns 0 and a suitable display number for the DISPLAY variable
2762: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2763: */
1.141 stevesk 2764: int
1.163 stevesk 2765: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2766: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2767: {
1.149 markus 2768: Channel *nc = NULL;
1.31 markus 2769: int display_number, sock;
2770: u_short port;
1.35 markus 2771: struct addrinfo hints, *ai, *aitop;
2772: char strport[NI_MAXSERV];
2773: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2774:
1.224 markus 2775: if (chanids == NULL)
2776: return -1;
2777:
1.33 markus 2778: for (display_number = x11_display_offset;
1.148 deraadt 2779: display_number < MAX_DISPLAYS;
2780: display_number++) {
1.25 markus 2781: port = 6000 + display_number;
1.35 markus 2782: memset(&hints, 0, sizeof(hints));
2783: hints.ai_family = IPv4or6;
1.163 stevesk 2784: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2785: hints.ai_socktype = SOCK_STREAM;
2786: snprintf(strport, sizeof strport, "%d", port);
2787: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2788: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2789: return -1;
1.25 markus 2790: }
1.35 markus 2791: for (ai = aitop; ai; ai = ai->ai_next) {
2792: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2793: continue;
1.189 markus 2794: sock = socket(ai->ai_family, ai->ai_socktype,
2795: ai->ai_protocol);
1.35 markus 2796: if (sock < 0) {
2797: error("socket: %.100s", strerror(errno));
1.203 markus 2798: freeaddrinfo(aitop);
1.141 stevesk 2799: return -1;
1.35 markus 2800: }
1.226 djm 2801: channel_set_reuseaddr(sock);
1.35 markus 2802: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2803: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2804: close(sock);
1.183 itojun 2805:
2806: if (ai->ai_next)
2807: continue;
2808:
1.35 markus 2809: for (n = 0; n < num_socks; n++) {
2810: close(socks[n]);
2811: }
2812: num_socks = 0;
2813: break;
2814: }
2815: socks[num_socks++] = sock;
2816: if (num_socks == NUM_SOCKS)
2817: break;
1.25 markus 2818: }
1.83 stevesk 2819: freeaddrinfo(aitop);
1.35 markus 2820: if (num_socks > 0)
2821: break;
1.25 markus 2822: }
2823: if (display_number >= MAX_DISPLAYS) {
2824: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2825: return -1;
1.25 markus 2826: }
2827: /* Start listening for connections on the socket. */
1.35 markus 2828: for (n = 0; n < num_socks; n++) {
2829: sock = socks[n];
1.199 markus 2830: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2831: error("listen: %.100s", strerror(errno));
2832: close(sock);
1.141 stevesk 2833: return -1;
1.35 markus 2834: }
1.25 markus 2835: }
1.35 markus 2836:
2837: /* Allocate a channel for each socket. */
1.242 djm 2838: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2839: for (n = 0; n < num_socks; n++) {
2840: sock = socks[n];
1.149 markus 2841: nc = channel_new("x11 listener",
1.51 markus 2842: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2843: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2844: 0, "X11 inet listener", 1);
1.167 markus 2845: nc->single_connection = single_connection;
1.224 markus 2846: (*chanids)[n] = nc->self;
1.35 markus 2847: }
1.224 markus 2848: (*chanids)[n] = -1;
1.1 deraadt 2849:
1.141 stevesk 2850: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2851: *display_numberp = display_number;
2852: return (0);
1.1 deraadt 2853: }
2854:
1.127 itojun 2855: static int
1.77 markus 2856: connect_local_xsocket(u_int dnr)
1.1 deraadt 2857: {
1.25 markus 2858: int sock;
2859: struct sockaddr_un addr;
2860:
1.147 stevesk 2861: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2862: if (sock < 0)
2863: error("socket: %.100s", strerror(errno));
2864: memset(&addr, 0, sizeof(addr));
2865: addr.sun_family = AF_UNIX;
2866: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2867: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2868: return sock;
2869: close(sock);
1.25 markus 2870: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2871: return -1;
1.1 deraadt 2872: }
2873:
1.51 markus 2874: int
2875: x11_connect_display(void)
1.1 deraadt 2876: {
1.248 deraadt 2877: u_int display_number;
1.25 markus 2878: const char *display;
1.51 markus 2879: char buf[1024], *cp;
1.35 markus 2880: struct addrinfo hints, *ai, *aitop;
2881: char strport[NI_MAXSERV];
1.248 deraadt 2882: int gaierr, sock = 0;
1.25 markus 2883:
2884: /* Try to open a socket for the local X server. */
2885: display = getenv("DISPLAY");
2886: if (!display) {
2887: error("DISPLAY not set.");
1.51 markus 2888: return -1;
1.25 markus 2889: }
1.27 markus 2890: /*
2891: * Now we decode the value of the DISPLAY variable and make a
2892: * connection to the real X server.
2893: */
2894:
2895: /*
2896: * Check if it is a unix domain socket. Unix domain displays are in
2897: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2898: */
1.25 markus 2899: if (strncmp(display, "unix:", 5) == 0 ||
2900: display[0] == ':') {
2901: /* Connect to the unix domain socket. */
1.248 deraadt 2902: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 2903: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2904: display);
1.51 markus 2905: return -1;
1.25 markus 2906: }
2907: /* Create a socket. */
2908: sock = connect_local_xsocket(display_number);
2909: if (sock < 0)
1.51 markus 2910: return -1;
1.25 markus 2911:
2912: /* OK, we now have a connection to the display. */
1.51 markus 2913: return sock;
1.25 markus 2914: }
1.27 markus 2915: /*
2916: * Connect to an inet socket. The DISPLAY value is supposedly
2917: * hostname:d[.s], where hostname may also be numeric IP address.
2918: */
1.145 stevesk 2919: strlcpy(buf, display, sizeof(buf));
1.25 markus 2920: cp = strchr(buf, ':');
2921: if (!cp) {
2922: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2923: return -1;
1.25 markus 2924: }
2925: *cp = 0;
1.27 markus 2926: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 2927: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 2928: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2929: display);
1.51 markus 2930: return -1;
1.25 markus 2931: }
1.35 markus 2932:
2933: /* Look up the host address */
2934: memset(&hints, 0, sizeof(hints));
2935: hints.ai_family = IPv4or6;
2936: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 2937: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 2938: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2939: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2940: return -1;
1.25 markus 2941: }
1.35 markus 2942: for (ai = aitop; ai; ai = ai->ai_next) {
2943: /* Create a socket. */
1.189 markus 2944: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2945: if (sock < 0) {
1.194 markus 2946: debug2("socket: %.100s", strerror(errno));
1.41 markus 2947: continue;
2948: }
2949: /* Connect it to the display. */
2950: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 2951: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 2952: 6000 + display_number, strerror(errno));
2953: close(sock);
2954: continue;
2955: }
2956: /* Success */
2957: break;
1.35 markus 2958: }
2959: freeaddrinfo(aitop);
2960: if (!ai) {
1.248 deraadt 2961: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 2962: strerror(errno));
1.51 markus 2963: return -1;
1.25 markus 2964: }
1.162 stevesk 2965: set_nodelay(sock);
1.51 markus 2966: return sock;
2967: }
2968:
2969: /*
2970: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2971: * the remote channel number. We should do whatever we want, and respond
2972: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2973: */
2974:
2975: void
1.154 markus 2976: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2977: {
1.113 markus 2978: Channel *c = NULL;
2979: int remote_id, sock = 0;
1.51 markus 2980: char *remote_host;
1.25 markus 2981:
1.113 markus 2982: debug("Received X11 open request.");
1.51 markus 2983:
1.113 markus 2984: remote_id = packet_get_int();
1.121 markus 2985:
2986: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2987: remote_host = packet_get_string(NULL);
1.51 markus 2988: } else {
2989: remote_host = xstrdup("unknown (remote did not supply name)");
2990: }
1.152 markus 2991: packet_check_eom();
1.25 markus 2992:
1.51 markus 2993: /* Obtain a connection to the real X display. */
2994: sock = x11_connect_display();
1.113 markus 2995: if (sock != -1) {
2996: /* Allocate a channel for this connection. */
2997: c = channel_new("connected x11 socket",
2998: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2999: remote_host, 1);
1.167 markus 3000: c->remote_id = remote_id;
3001: c->force_drain = 1;
1.113 markus 3002: }
1.190 markus 3003: xfree(remote_host);
1.113 markus 3004: if (c == NULL) {
1.51 markus 3005: /* Send refusal to the remote host. */
3006: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3007: packet_put_int(remote_id);
1.51 markus 3008: } else {
3009: /* Send a confirmation to the remote host. */
3010: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3011: packet_put_int(remote_id);
3012: packet_put_int(c->self);
1.51 markus 3013: }
1.113 markus 3014: packet_send();
1.72 markus 3015: }
3016:
3017: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3018: void
1.154 markus 3019: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3020: {
3021: int rchan = packet_get_int();
1.180 deraadt 3022:
1.143 deraadt 3023: switch (type) {
1.72 markus 3024: case SSH_SMSG_AGENT_OPEN:
3025: error("Warning: ssh server tried agent forwarding.");
3026: break;
3027: case SSH_SMSG_X11_OPEN:
3028: error("Warning: ssh server tried X11 forwarding.");
3029: break;
3030: default:
1.154 markus 3031: error("deny_input_open: type %d", type);
1.72 markus 3032: break;
3033: }
1.230 stevesk 3034: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3035: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3036: packet_put_int(rchan);
3037: packet_send();
1.1 deraadt 3038: }
3039:
1.27 markus 3040: /*
3041: * Requests forwarding of X11 connections, generates fake authentication
3042: * data, and enables authentication spoofing.
1.121 markus 3043: * This should be called in the client only.
1.27 markus 3044: */
1.49 markus 3045: void
1.215 djm 3046: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3047: const char *proto, const char *data)
1.1 deraadt 3048: {
1.77 markus 3049: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3050: u_int i, value;
1.25 markus 3051: char *new_data;
3052: int screen_number;
3053: const char *cp;
1.207 avsm 3054: u_int32_t rnd = 0;
1.25 markus 3055:
1.220 markus 3056: if (x11_saved_display == NULL)
3057: x11_saved_display = xstrdup(disp);
3058: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3059: error("x11_request_forwarding_with_spoofing: different "
3060: "$DISPLAY already forwarded");
3061: return;
3062: }
3063:
1.215 djm 3064: cp = disp;
3065: if (disp)
3066: cp = strchr(disp, ':');
1.25 markus 3067: if (cp)
3068: cp = strchr(cp, '.');
3069: if (cp)
1.245 deraadt 3070: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3071: else
3072: screen_number = 0;
3073:
1.219 djm 3074: if (x11_saved_proto == NULL) {
3075: /* Save protocol name. */
3076: x11_saved_proto = xstrdup(proto);
3077: /*
1.221 djm 3078: * Extract real authentication data and generate fake data
1.219 djm 3079: * of the same length.
3080: */
3081: x11_saved_data = xmalloc(data_len);
3082: x11_fake_data = xmalloc(data_len);
3083: for (i = 0; i < data_len; i++) {
3084: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3085: fatal("x11_request_forwarding: bad "
3086: "authentication data: %.100s", data);
3087: if (i % 4 == 0)
3088: rnd = arc4random();
3089: x11_saved_data[i] = value;
3090: x11_fake_data[i] = rnd & 0xff;
3091: rnd >>= 8;
3092: }
3093: x11_saved_data_len = data_len;
3094: x11_fake_data_len = data_len;
1.25 markus 3095: }
3096:
3097: /* Convert the fake data into hex. */
1.219 djm 3098: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3099:
3100: /* Send the request packet. */
1.51 markus 3101: if (compat20) {
3102: channel_request_start(client_session_id, "x11-req", 0);
3103: packet_put_char(0); /* XXX bool single connection */
3104: } else {
3105: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3106: }
3107: packet_put_cstring(proto);
3108: packet_put_cstring(new_data);
1.25 markus 3109: packet_put_int(screen_number);
3110: packet_send();
3111: packet_write_wait();
3112: xfree(new_data);
1.1 deraadt 3113: }
3114:
1.121 markus 3115:
3116: /* -- agent forwarding */
3117:
1.1 deraadt 3118: /* Sends a message to the server to request authentication fd forwarding. */
3119:
1.49 markus 3120: void
1.142 itojun 3121: auth_request_forwarding(void)
1.1 deraadt 3122: {
1.25 markus 3123: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3124: packet_send();
3125: packet_write_wait();
1.1 deraadt 3126: }
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