Annotation of src/usr.bin/ssh/channels.c, Revision 1.309
1.309 ! djm 1: /* $OpenBSD: channels.c,v 1.308 2010/07/13 23:13:16 djm 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:
1.265 deraadt 42: #include <sys/types.h>
1.234 stevesk 43: #include <sys/ioctl.h>
1.235 stevesk 44: #include <sys/un.h>
1.251 stevesk 45: #include <sys/socket.h>
1.261 stevesk 46: #include <sys/time.h>
1.275 djm 47: #include <sys/queue.h>
1.251 stevesk 48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.298 dtucker 53: #include <fcntl.h>
1.255 stevesk 54: #include <netdb.h>
1.263 stevesk 55: #include <stdio.h>
1.262 stevesk 56: #include <stdlib.h>
1.260 stevesk 57: #include <string.h>
1.233 stevesk 58: #include <termios.h>
1.256 stevesk 59: #include <unistd.h>
1.265 deraadt 60: #include <stdarg.h>
1.1 deraadt 61:
1.265 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.82 markus 64: #include "ssh1.h"
65: #include "ssh2.h"
1.1 deraadt 66: #include "packet.h"
1.82 markus 67: #include "log.h"
68: #include "misc.h"
1.265 deraadt 69: #include "buffer.h"
1.14 markus 70: #include "channels.h"
71: #include "compat.h"
1.82 markus 72: #include "canohost.h"
1.64 markus 73: #include "key.h"
74: #include "authfd.h"
1.147 stevesk 75: #include "pathnames.h"
1.1 deraadt 76:
1.121 markus 77: /* -- channel core */
1.12 markus 78:
1.27 markus 79: /*
80: * Pointer to an array containing all allocated channels. The array is
81: * dynamically extended as needed.
82: */
1.113 markus 83: static Channel **channels = NULL;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Size of the channel array. All slots of the array must always be
1.113 markus 87: * initialized (at least the type field); unused slots set to NULL
1.27 markus 88: */
1.209 avsm 89: static u_int channels_alloc = 0;
1.1 deraadt 90:
1.27 markus 91: /*
92: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 93: * updated in channel_new.
1.27 markus 94: */
1.84 markus 95: static int channel_max_fd = 0;
1.1 deraadt 96:
97:
1.121 markus 98: /* -- tcp forwarding */
1.1 deraadt 99:
1.27 markus 100: /*
101: * Data structure for storing which hosts are permitted for forward requests.
102: * The local sides of any remote forwards are stored in this array to prevent
103: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
104: * network (which might be behind a firewall).
105: */
1.25 markus 106: typedef struct {
1.41 markus 107: char *host_to_connect; /* Connect to 'host'. */
108: u_short port_to_connect; /* Connect to 'port'. */
109: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 110: } ForwardPermission;
111:
1.257 dtucker 112: /* List of all permitted host/port pairs to connect by the user. */
1.305 djm 113: static ForwardPermission *permitted_opens = NULL;
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
1.305 djm 116: static ForwardPermission *permitted_adm_opens = NULL;
1.257 dtucker 117:
118: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 119: static int num_permitted_opens = 0;
1.257 dtucker 120:
121: /* Number of permitted host/port pair in the array permitted by the admin. */
122: static int num_adm_permitted_opens = 0;
123:
1.27 markus 124: /*
125: * If this is true, all opens are permitted. This is the case on the server
126: * on which we have to trust the client anyway, and the user could do
127: * anything after logging in anyway.
128: */
1.1 deraadt 129: static int all_opens_permitted = 0;
130:
1.121 markus 131:
132: /* -- X11 forwarding */
133:
134: /* Maximum number of fake X11 displays to try. */
135: #define MAX_DISPLAYS 1000
136:
1.219 djm 137: /* Saved X11 local (client) display. */
138: static char *x11_saved_display = NULL;
139:
1.121 markus 140: /* Saved X11 authentication protocol name. */
141: static char *x11_saved_proto = NULL;
142:
143: /* Saved X11 authentication data. This is the real data. */
144: static char *x11_saved_data = NULL;
145: static u_int x11_saved_data_len = 0;
146:
147: /*
148: * Fake X11 authentication data. This is what the server will be sending us;
149: * we should replace any occurrences of this by the real data.
150: */
1.240 deraadt 151: static u_char *x11_fake_data = NULL;
1.121 markus 152: static u_int x11_fake_data_len;
153:
154:
155: /* -- agent forwarding */
156:
157: #define NUM_SOCKS 10
158:
1.82 markus 159: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 160: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 161:
1.121 markus 162: /* helper */
1.127 itojun 163: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 164:
1.276 djm 165: /* non-blocking connect helpers */
166: static int connect_next(struct channel_connect *);
167: static void channel_connect_ctx_free(struct channel_connect *);
168:
1.121 markus 169: /* -- channel core */
1.41 markus 170:
171: Channel *
1.229 markus 172: channel_by_id(int id)
1.41 markus 173: {
174: Channel *c;
1.113 markus 175:
1.209 avsm 176: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 177: logit("channel_by_id: %d: bad id", id);
1.41 markus 178: return NULL;
179: }
1.113 markus 180: c = channels[id];
181: if (c == NULL) {
1.229 markus 182: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 183: return NULL;
184: }
185: return c;
1.55 markus 186: }
187:
1.27 markus 188: /*
1.229 markus 189: * Returns the channel if it is allowed to receive protocol messages.
190: * Private channels, like listening sockets, may not receive messages.
191: */
192: Channel *
193: channel_lookup(int id)
194: {
195: Channel *c;
196:
197: if ((c = channel_by_id(id)) == NULL)
198: return (NULL);
199:
1.237 deraadt 200: switch (c->type) {
1.229 markus 201: case SSH_CHANNEL_X11_OPEN:
202: case SSH_CHANNEL_LARVAL:
203: case SSH_CHANNEL_CONNECTING:
204: case SSH_CHANNEL_DYNAMIC:
205: case SSH_CHANNEL_OPENING:
206: case SSH_CHANNEL_OPEN:
207: case SSH_CHANNEL_INPUT_DRAINING:
208: case SSH_CHANNEL_OUTPUT_DRAINING:
209: return (c);
210: }
211: logit("Non-public channel %d, type %d.", id, c->type);
212: return (NULL);
213: }
214:
215: /*
1.55 markus 216: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 217: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 218: */
1.127 itojun 219: static void
1.71 markus 220: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 221: int extusage, int nonblock, int is_tty)
1.1 deraadt 222: {
1.25 markus 223: /* Update the maximum file descriptor value. */
1.84 markus 224: channel_max_fd = MAX(channel_max_fd, rfd);
225: channel_max_fd = MAX(channel_max_fd, wfd);
226: channel_max_fd = MAX(channel_max_fd, efd);
227:
1.298 dtucker 228: if (rfd != -1)
229: fcntl(rfd, F_SETFD, FD_CLOEXEC);
230: if (wfd != -1 && wfd != rfd)
231: fcntl(wfd, F_SETFD, FD_CLOEXEC);
232: if (efd != -1 && efd != rfd && efd != wfd)
233: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 234:
1.52 markus 235: c->rfd = rfd;
236: c->wfd = wfd;
237: c->sock = (rfd == wfd) ? rfd : -1;
238: c->efd = efd;
239: c->extended_usage = extusage;
1.71 markus 240:
1.282 dtucker 241: if ((c->isatty = is_tty) != 0)
1.194 markus 242: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 243:
1.71 markus 244: /* enable nonblocking mode */
245: if (nonblock) {
246: if (rfd != -1)
247: set_nonblock(rfd);
248: if (wfd != -1)
249: set_nonblock(wfd);
250: if (efd != -1)
251: set_nonblock(efd);
252: }
1.52 markus 253: }
254:
255: /*
256: * Allocate a new channel object and set its type and socket. This will cause
257: * remote_name to be freed.
258: */
1.113 markus 259: Channel *
1.52 markus 260: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 261: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 262: {
1.209 avsm 263: int found;
264: u_int i;
1.52 markus 265: Channel *c;
1.25 markus 266:
267: /* Do initial allocation if this is the first call. */
268: if (channels_alloc == 0) {
269: channels_alloc = 10;
1.242 djm 270: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 271: for (i = 0; i < channels_alloc; i++)
1.113 markus 272: channels[i] = NULL;
1.25 markus 273: }
274: /* Try to find a free slot where to put the new channel. */
275: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 276: if (channels[i] == NULL) {
1.25 markus 277: /* Found a free slot. */
1.209 avsm 278: found = (int)i;
1.25 markus 279: break;
280: }
1.209 avsm 281: if (found < 0) {
1.27 markus 282: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 283: found = channels_alloc;
1.179 markus 284: if (channels_alloc > 10000)
285: fatal("channel_new: internal error: channels_alloc %d "
286: "too big.", channels_alloc);
1.243 djm 287: channels = xrealloc(channels, channels_alloc + 10,
288: sizeof(Channel *));
1.195 markus 289: channels_alloc += 10;
1.70 markus 290: debug2("channel: expanding %d", channels_alloc);
1.25 markus 291: for (i = found; i < channels_alloc; i++)
1.113 markus 292: channels[i] = NULL;
1.25 markus 293: }
1.113 markus 294: /* Initialize and return new channel. */
1.242 djm 295: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 296: buffer_init(&c->input);
297: buffer_init(&c->output);
1.41 markus 298: buffer_init(&c->extended);
1.293 djm 299: c->path = NULL;
1.159 markus 300: c->ostate = CHAN_OUTPUT_OPEN;
301: c->istate = CHAN_INPUT_OPEN;
302: c->flags = 0;
1.281 djm 303: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.25 markus 304: c->self = found;
305: c->type = type;
1.41 markus 306: c->ctype = ctype;
1.51 markus 307: c->local_window = window;
308: c->local_window_max = window;
309: c->local_consumed = 0;
310: c->local_maxpacket = maxpack;
1.25 markus 311: c->remote_id = -1;
1.190 markus 312: c->remote_name = xstrdup(remote_name);
1.41 markus 313: c->remote_window = 0;
314: c->remote_maxpacket = 0;
1.133 markus 315: c->force_drain = 0;
1.149 markus 316: c->single_connection = 0;
1.131 markus 317: c->detach_user = NULL;
1.225 djm 318: c->detach_close = 0;
1.275 djm 319: c->open_confirm = NULL;
320: c->open_confirm_ctx = NULL;
1.65 markus 321: c->input_filter = NULL;
1.231 reyk 322: c->output_filter = NULL;
1.280 djm 323: c->filter_ctx = NULL;
324: c->filter_cleanup = NULL;
1.302 djm 325: c->ctl_chan = -1;
326: c->mux_rcb = NULL;
327: c->mux_ctx = NULL;
1.304 djm 328: c->mux_pause = 0;
1.299 markus 329: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 330: TAILQ_INIT(&c->status_confirms);
1.25 markus 331: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 332: return c;
1.1 deraadt 333: }
1.52 markus 334:
1.132 markus 335: static int
336: channel_find_maxfd(void)
337: {
1.209 avsm 338: u_int i;
339: int max = 0;
1.132 markus 340: Channel *c;
341:
342: for (i = 0; i < channels_alloc; i++) {
343: c = channels[i];
344: if (c != NULL) {
345: max = MAX(max, c->rfd);
346: max = MAX(max, c->wfd);
347: max = MAX(max, c->efd);
348: }
349: }
350: return max;
351: }
352:
353: int
354: channel_close_fd(int *fdp)
355: {
356: int ret = 0, fd = *fdp;
357:
358: if (fd != -1) {
359: ret = close(fd);
360: *fdp = -1;
361: if (fd == channel_max_fd)
362: channel_max_fd = channel_find_maxfd();
363: }
364: return ret;
365: }
366:
1.52 markus 367: /* Close all channel fd/socket. */
1.127 itojun 368: static void
1.52 markus 369: channel_close_fds(Channel *c)
370: {
1.302 djm 371: debug3("channel %d: close_fds r %d w %d e %d",
372: c->self, c->rfd, c->wfd, c->efd);
1.118 markus 373:
1.132 markus 374: channel_close_fd(&c->sock);
375: channel_close_fd(&c->rfd);
376: channel_close_fd(&c->wfd);
377: channel_close_fd(&c->efd);
1.121 markus 378: }
379:
380: /* Free the channel and close its fd/socket. */
381: void
382: channel_free(Channel *c)
383: {
384: char *s;
1.209 avsm 385: u_int i, n;
1.275 djm 386: struct channel_confirm *cc;
1.121 markus 387:
388: for (n = 0, i = 0; i < channels_alloc; i++)
389: if (channels[i])
390: n++;
1.209 avsm 391: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 392: c->remote_name ? c->remote_name : "???", n);
393:
394: s = channel_open_message();
1.194 markus 395: debug3("channel %d: status: %s", c->self, s);
1.121 markus 396: xfree(s);
397:
398: if (c->sock != -1)
399: shutdown(c->sock, SHUT_RDWR);
400: channel_close_fds(c);
401: buffer_free(&c->input);
402: buffer_free(&c->output);
403: buffer_free(&c->extended);
404: if (c->remote_name) {
405: xfree(c->remote_name);
406: c->remote_name = NULL;
407: }
1.293 djm 408: if (c->path) {
409: xfree(c->path);
410: c->path = NULL;
411: }
1.275 djm 412: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
413: if (cc->abandon_cb != NULL)
414: cc->abandon_cb(c, cc->ctx);
415: TAILQ_REMOVE(&c->status_confirms, cc, entry);
416: bzero(cc, sizeof(*cc));
417: xfree(cc);
418: }
1.280 djm 419: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
420: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 421: channels[c->self] = NULL;
422: xfree(c);
423: }
424:
425: void
1.126 markus 426: channel_free_all(void)
1.121 markus 427: {
1.209 avsm 428: u_int i;
1.121 markus 429:
1.126 markus 430: for (i = 0; i < channels_alloc; i++)
431: if (channels[i] != NULL)
432: channel_free(channels[i]);
1.131 markus 433: }
434:
1.121 markus 435: /*
436: * Closes the sockets/fds of all channels. This is used to close extra file
437: * descriptors after a fork.
438: */
439: void
1.142 itojun 440: channel_close_all(void)
1.121 markus 441: {
1.209 avsm 442: u_int i;
1.121 markus 443:
444: for (i = 0; i < channels_alloc; i++)
445: if (channels[i] != NULL)
446: channel_close_fds(channels[i]);
447: }
448:
449: /*
1.131 markus 450: * Stop listening to channels.
451: */
452: void
453: channel_stop_listening(void)
454: {
1.209 avsm 455: u_int i;
1.131 markus 456: Channel *c;
457:
458: for (i = 0; i < channels_alloc; i++) {
459: c = channels[i];
460: if (c != NULL) {
461: switch (c->type) {
462: case SSH_CHANNEL_AUTH_SOCKET:
463: case SSH_CHANNEL_PORT_LISTENER:
464: case SSH_CHANNEL_RPORT_LISTENER:
465: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 466: channel_close_fd(&c->sock);
1.131 markus 467: channel_free(c);
468: break;
469: }
470: }
471: }
472: }
473:
474: /*
1.121 markus 475: * Returns true if no channel has too much buffered data, and false if one or
476: * more channel is overfull.
477: */
478: int
1.142 itojun 479: channel_not_very_much_buffered_data(void)
1.121 markus 480: {
481: u_int i;
482: Channel *c;
483:
484: for (i = 0; i < channels_alloc; i++) {
485: c = channels[i];
486: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 487: #if 0
488: if (!compat20 &&
489: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 490: debug2("channel %d: big input buffer %d",
1.121 markus 491: c->self, buffer_len(&c->input));
492: return 0;
493: }
1.136 markus 494: #endif
1.121 markus 495: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 496: debug2("channel %d: big output buffer %u > %u",
1.136 markus 497: c->self, buffer_len(&c->output),
498: packet_get_maxsize());
1.121 markus 499: return 0;
500: }
501: }
502: }
503: return 1;
504: }
505:
506: /* Returns true if any channel is still open. */
507: int
1.142 itojun 508: channel_still_open(void)
1.121 markus 509: {
1.209 avsm 510: u_int i;
1.121 markus 511: Channel *c;
512:
513: for (i = 0; i < channels_alloc; i++) {
514: c = channels[i];
515: if (c == NULL)
516: continue;
517: switch (c->type) {
518: case SSH_CHANNEL_X11_LISTENER:
519: case SSH_CHANNEL_PORT_LISTENER:
520: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 521: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 522: case SSH_CHANNEL_CLOSED:
523: case SSH_CHANNEL_AUTH_SOCKET:
524: case SSH_CHANNEL_DYNAMIC:
525: case SSH_CHANNEL_CONNECTING:
526: case SSH_CHANNEL_ZOMBIE:
527: continue;
528: case SSH_CHANNEL_LARVAL:
529: if (!compat20)
530: fatal("cannot happen: SSH_CHANNEL_LARVAL");
531: continue;
532: case SSH_CHANNEL_OPENING:
533: case SSH_CHANNEL_OPEN:
534: case SSH_CHANNEL_X11_OPEN:
1.302 djm 535: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 536: return 1;
537: case SSH_CHANNEL_INPUT_DRAINING:
538: case SSH_CHANNEL_OUTPUT_DRAINING:
539: if (!compat13)
540: fatal("cannot happen: OUT_DRAIN");
541: return 1;
542: default:
543: fatal("channel_still_open: bad channel type %d", c->type);
544: /* NOTREACHED */
545: }
546: }
547: return 0;
548: }
549:
550: /* Returns the id of an open channel suitable for keepaliving */
551: int
1.142 itojun 552: channel_find_open(void)
1.121 markus 553: {
1.209 avsm 554: u_int i;
1.121 markus 555: Channel *c;
556:
557: for (i = 0; i < channels_alloc; i++) {
558: c = channels[i];
1.206 djm 559: if (c == NULL || c->remote_id < 0)
1.121 markus 560: continue;
561: switch (c->type) {
562: case SSH_CHANNEL_CLOSED:
563: case SSH_CHANNEL_DYNAMIC:
564: case SSH_CHANNEL_X11_LISTENER:
565: case SSH_CHANNEL_PORT_LISTENER:
566: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 567: case SSH_CHANNEL_MUX_LISTENER:
568: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 569: case SSH_CHANNEL_OPENING:
570: case SSH_CHANNEL_CONNECTING:
571: case SSH_CHANNEL_ZOMBIE:
572: continue;
573: case SSH_CHANNEL_LARVAL:
574: case SSH_CHANNEL_AUTH_SOCKET:
575: case SSH_CHANNEL_OPEN:
576: case SSH_CHANNEL_X11_OPEN:
577: return i;
578: case SSH_CHANNEL_INPUT_DRAINING:
579: case SSH_CHANNEL_OUTPUT_DRAINING:
580: if (!compat13)
581: fatal("cannot happen: OUT_DRAIN");
582: return i;
583: default:
584: fatal("channel_find_open: bad channel type %d", c->type);
585: /* NOTREACHED */
586: }
587: }
588: return -1;
589: }
590:
591:
592: /*
593: * Returns a message describing the currently open forwarded connections,
594: * suitable for sending to the client. The message contains crlf pairs for
595: * newlines.
596: */
597: char *
1.142 itojun 598: channel_open_message(void)
1.121 markus 599: {
600: Buffer buffer;
601: Channel *c;
602: char buf[1024], *cp;
1.209 avsm 603: u_int i;
1.121 markus 604:
605: buffer_init(&buffer);
606: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
607: buffer_append(&buffer, buf, strlen(buf));
608: for (i = 0; i < channels_alloc; i++) {
609: c = channels[i];
610: if (c == NULL)
611: continue;
612: switch (c->type) {
613: case SSH_CHANNEL_X11_LISTENER:
614: case SSH_CHANNEL_PORT_LISTENER:
615: case SSH_CHANNEL_RPORT_LISTENER:
616: case SSH_CHANNEL_CLOSED:
617: case SSH_CHANNEL_AUTH_SOCKET:
618: case SSH_CHANNEL_ZOMBIE:
1.302 djm 619: case SSH_CHANNEL_MUX_CLIENT:
620: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 621: continue;
622: case SSH_CHANNEL_LARVAL:
623: case SSH_CHANNEL_OPENING:
624: case SSH_CHANNEL_CONNECTING:
625: case SSH_CHANNEL_DYNAMIC:
626: case SSH_CHANNEL_OPEN:
627: case SSH_CHANNEL_X11_OPEN:
628: case SSH_CHANNEL_INPUT_DRAINING:
629: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 630: snprintf(buf, sizeof buf,
1.302 djm 631: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
1.121 markus 632: c->self, c->remote_name,
633: c->type, c->remote_id,
634: c->istate, buffer_len(&c->input),
635: c->ostate, buffer_len(&c->output),
1.302 djm 636: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 637: buffer_append(&buffer, buf, strlen(buf));
638: continue;
639: default:
640: fatal("channel_open_message: bad channel type %d", c->type);
641: /* NOTREACHED */
642: }
643: }
644: buffer_append(&buffer, "\0", 1);
645: cp = xstrdup(buffer_ptr(&buffer));
646: buffer_free(&buffer);
647: return cp;
648: }
649:
650: void
651: channel_send_open(int id)
652: {
653: Channel *c = channel_lookup(id);
1.180 deraadt 654:
1.121 markus 655: if (c == NULL) {
1.188 itojun 656: logit("channel_send_open: %d: bad id", id);
1.121 markus 657: return;
658: }
1.184 markus 659: debug2("channel %d: send open", id);
1.121 markus 660: packet_start(SSH2_MSG_CHANNEL_OPEN);
661: packet_put_cstring(c->ctype);
662: packet_put_int(c->self);
663: packet_put_int(c->local_window);
664: packet_put_int(c->local_maxpacket);
665: packet_send();
666: }
667:
668: void
1.184 markus 669: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 670: {
1.184 markus 671: Channel *c = channel_lookup(id);
1.180 deraadt 672:
1.121 markus 673: if (c == NULL) {
1.188 itojun 674: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 675: return;
676: }
1.204 djm 677: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 678: packet_start(SSH2_MSG_CHANNEL_REQUEST);
679: packet_put_int(c->remote_id);
680: packet_put_cstring(service);
681: packet_put_char(wantconfirm);
682: }
1.241 deraadt 683:
1.121 markus 684: void
1.275 djm 685: channel_register_status_confirm(int id, channel_confirm_cb *cb,
686: channel_confirm_abandon_cb *abandon_cb, void *ctx)
687: {
688: struct channel_confirm *cc;
689: Channel *c;
690:
691: if ((c = channel_lookup(id)) == NULL)
692: fatal("channel_register_expect: %d: bad id", id);
693:
694: cc = xmalloc(sizeof(*cc));
695: cc->cb = cb;
696: cc->abandon_cb = abandon_cb;
697: cc->ctx = ctx;
698: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
699: }
700:
701: void
1.304 djm 702: channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
1.121 markus 703: {
704: Channel *c = channel_lookup(id);
1.180 deraadt 705:
1.121 markus 706: if (c == NULL) {
1.287 stevesk 707: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 708: return;
709: }
1.275 djm 710: c->open_confirm = fn;
711: c->open_confirm_ctx = ctx;
1.121 markus 712: }
1.241 deraadt 713:
1.121 markus 714: void
1.225 djm 715: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 716: {
1.229 markus 717: Channel *c = channel_by_id(id);
1.180 deraadt 718:
1.121 markus 719: if (c == NULL) {
1.188 itojun 720: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 721: return;
722: }
1.131 markus 723: c->detach_user = fn;
1.225 djm 724: c->detach_close = do_close;
1.121 markus 725: }
1.241 deraadt 726:
1.121 markus 727: void
728: channel_cancel_cleanup(int id)
729: {
1.229 markus 730: Channel *c = channel_by_id(id);
1.180 deraadt 731:
1.121 markus 732: if (c == NULL) {
1.188 itojun 733: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 734: return;
1.52 markus 735: }
1.131 markus 736: c->detach_user = NULL;
1.225 djm 737: c->detach_close = 0;
1.121 markus 738: }
1.241 deraadt 739:
1.121 markus 740: void
1.231 reyk 741: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 742: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 743: {
744: Channel *c = channel_lookup(id);
1.180 deraadt 745:
1.121 markus 746: if (c == NULL) {
1.188 itojun 747: logit("channel_register_filter: %d: bad id", id);
1.121 markus 748: return;
1.52 markus 749: }
1.231 reyk 750: c->input_filter = ifn;
751: c->output_filter = ofn;
1.279 djm 752: c->filter_ctx = ctx;
1.280 djm 753: c->filter_cleanup = cfn;
1.52 markus 754: }
755:
1.49 markus 756: void
1.121 markus 757: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 758: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 759: {
1.121 markus 760: Channel *c = channel_lookup(id);
1.180 deraadt 761:
1.121 markus 762: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
763: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 764: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 765: c->type = SSH_CHANNEL_OPEN;
1.168 markus 766: c->local_window = c->local_window_max = window_max;
1.121 markus 767: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
768: packet_put_int(c->remote_id);
769: packet_put_int(c->local_window);
770: packet_send();
1.1 deraadt 771: }
772:
1.27 markus 773: /*
1.41 markus 774: * 'channel_pre*' are called just before select() to add any bits relevant to
775: * channels in the select bitmasks.
776: */
777: /*
778: * 'channel_post*': perform any appropriate operations for channels which
779: * have events pending.
1.27 markus 780: */
1.237 deraadt 781: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 782: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
783: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
784:
1.259 stevesk 785: /* ARGSUSED */
1.127 itojun 786: static void
1.237 deraadt 787: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 788: {
789: FD_SET(c->sock, readset);
790: }
791:
1.259 stevesk 792: /* ARGSUSED */
1.127 itojun 793: static void
1.237 deraadt 794: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 795: {
796: debug3("channel %d: waiting for connection", c->self);
797: FD_SET(c->sock, writeset);
798: }
799:
1.127 itojun 800: static void
1.237 deraadt 801: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 802: {
803: if (buffer_len(&c->input) < packet_get_maxsize())
804: FD_SET(c->sock, readset);
805: if (buffer_len(&c->output) > 0)
806: FD_SET(c->sock, writeset);
807: }
1.1 deraadt 808:
1.127 itojun 809: static void
1.237 deraadt 810: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 811: {
1.157 markus 812: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 813:
1.44 markus 814: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 815: limit > 0 &&
1.250 djm 816: buffer_len(&c->input) < limit &&
817: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 818: FD_SET(c->rfd, readset);
819: if (c->ostate == CHAN_OUTPUT_OPEN ||
820: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
821: if (buffer_len(&c->output) > 0) {
822: FD_SET(c->wfd, writeset);
823: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 824: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 825: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
826: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 827: else
828: chan_obuf_empty(c);
1.44 markus 829: }
830: }
831: /** XXX check close conditions, too */
1.277 markus 832: if (compat20 && c->efd != -1 &&
833: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 834: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
835: buffer_len(&c->extended) > 0)
836: FD_SET(c->efd, writeset);
1.306 djm 837: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
838: (c->extended_usage == CHAN_EXTENDED_READ ||
839: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 840: buffer_len(&c->extended) < c->remote_window)
841: FD_SET(c->efd, readset);
842: }
1.204 djm 843: /* XXX: What about efd? races? */
1.44 markus 844: }
845:
1.259 stevesk 846: /* ARGSUSED */
1.127 itojun 847: static void
1.237 deraadt 848: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 849: {
850: if (buffer_len(&c->input) == 0) {
851: packet_start(SSH_MSG_CHANNEL_CLOSE);
852: packet_put_int(c->remote_id);
853: packet_send();
854: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 855: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 856: }
857: }
858:
1.259 stevesk 859: /* ARGSUSED */
1.127 itojun 860: static void
1.237 deraadt 861: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 862: {
863: if (buffer_len(&c->output) == 0)
1.113 markus 864: chan_mark_dead(c);
1.49 markus 865: else
1.41 markus 866: FD_SET(c->sock, writeset);
867: }
868:
869: /*
870: * This is a special state for X11 authentication spoofing. An opened X11
871: * connection (when authentication spoofing is being done) remains in this
872: * state until the first packet has been completely read. The authentication
873: * data in that packet is then substituted by the real data if it matches the
874: * fake data, and the channel is put into normal mode.
1.51 markus 875: * XXX All this happens at the client side.
1.121 markus 876: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 877: */
1.127 itojun 878: static int
1.121 markus 879: x11_open_helper(Buffer *b)
1.1 deraadt 880: {
1.77 markus 881: u_char *ucp;
882: u_int proto_len, data_len;
1.25 markus 883:
1.41 markus 884: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 885: if (buffer_len(b) < 12)
1.41 markus 886: return 0;
887:
888: /* Parse the lengths of variable-length fields. */
1.155 stevesk 889: ucp = buffer_ptr(b);
1.41 markus 890: if (ucp[0] == 0x42) { /* Byte order MSB first. */
891: proto_len = 256 * ucp[6] + ucp[7];
892: data_len = 256 * ucp[8] + ucp[9];
893: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
894: proto_len = ucp[6] + 256 * ucp[7];
895: data_len = ucp[8] + 256 * ucp[9];
896: } else {
1.194 markus 897: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 898: ucp[0]);
1.41 markus 899: return -1;
900: }
901:
902: /* Check if the whole packet is in buffer. */
1.121 markus 903: if (buffer_len(b) <
1.41 markus 904: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
905: return 0;
906:
907: /* Check if authentication protocol matches. */
908: if (proto_len != strlen(x11_saved_proto) ||
909: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 910: debug2("X11 connection uses different authentication protocol.");
1.41 markus 911: return -1;
912: }
913: /* Check if authentication data matches our fake data. */
914: if (data_len != x11_fake_data_len ||
1.308 djm 915: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.41 markus 916: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 917: debug2("X11 auth data does not match fake data.");
1.41 markus 918: return -1;
919: }
920: /* Check fake data length */
921: if (x11_fake_data_len != x11_saved_data_len) {
922: error("X11 fake_data_len %d != saved_data_len %d",
923: x11_fake_data_len, x11_saved_data_len);
924: return -1;
925: }
926: /*
927: * Received authentication protocol and data match
928: * our fake data. Substitute the fake data with real
929: * data.
930: */
931: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
932: x11_saved_data, x11_saved_data_len);
933: return 1;
934: }
935:
1.127 itojun 936: static void
1.237 deraadt 937: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 938: {
1.121 markus 939: int ret = x11_open_helper(&c->output);
1.180 deraadt 940:
1.41 markus 941: if (ret == 1) {
942: /* Start normal processing for the channel. */
943: c->type = SSH_CHANNEL_OPEN;
1.47 markus 944: channel_pre_open_13(c, readset, writeset);
1.41 markus 945: } else if (ret == -1) {
946: /*
947: * We have received an X11 connection that has bad
948: * authentication information.
949: */
1.188 itojun 950: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 951: buffer_clear(&c->input);
952: buffer_clear(&c->output);
1.132 markus 953: channel_close_fd(&c->sock);
1.41 markus 954: c->sock = -1;
955: c->type = SSH_CHANNEL_CLOSED;
956: packet_start(SSH_MSG_CHANNEL_CLOSE);
957: packet_put_int(c->remote_id);
958: packet_send();
959: }
960: }
1.25 markus 961:
1.127 itojun 962: static void
1.237 deraadt 963: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 964: {
1.121 markus 965: int ret = x11_open_helper(&c->output);
1.133 markus 966:
967: /* c->force_drain = 1; */
968:
1.41 markus 969: if (ret == 1) {
970: c->type = SSH_CHANNEL_OPEN;
1.157 markus 971: channel_pre_open(c, readset, writeset);
1.41 markus 972: } else if (ret == -1) {
1.188 itojun 973: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 974: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 975: chan_read_failed(c);
976: buffer_clear(&c->input);
977: chan_ibuf_empty(c);
978: buffer_clear(&c->output);
979: /* for proto v1, the peer will send an IEOF */
980: if (compat20)
981: chan_write_failed(c);
982: else
983: c->type = SSH_CHANNEL_OPEN;
1.194 markus 984: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 985: }
986: }
1.25 markus 987:
1.302 djm 988: static void
989: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
990: {
1.304 djm 991: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 992: buffer_check_alloc(&c->input, CHAN_RBUF))
993: FD_SET(c->rfd, readset);
994: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
995: /* clear buffer immediately (discard any partial packet) */
996: buffer_clear(&c->input);
997: chan_ibuf_empty(c);
998: /* Start output drain. XXX just kill chan? */
999: chan_rcvd_oclose(c);
1000: }
1001: if (c->ostate == CHAN_OUTPUT_OPEN ||
1002: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1003: if (buffer_len(&c->output) > 0)
1004: FD_SET(c->wfd, writeset);
1005: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1006: chan_obuf_empty(c);
1007: }
1008: }
1009:
1.104 markus 1010: /* try to decode a socks4 header */
1.259 stevesk 1011: /* ARGSUSED */
1.127 itojun 1012: static int
1.237 deraadt 1013: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1014: {
1.181 markus 1015: char *p, *host;
1.292 djm 1016: u_int len, have, i, found, need;
1.148 deraadt 1017: char username[256];
1.103 markus 1018: struct {
1019: u_int8_t version;
1020: u_int8_t command;
1021: u_int16_t dest_port;
1.104 markus 1022: struct in_addr dest_addr;
1.103 markus 1023: } s4_req, s4_rsp;
1024:
1.104 markus 1025: debug2("channel %d: decode socks4", c->self);
1.109 markus 1026:
1027: have = buffer_len(&c->input);
1028: len = sizeof(s4_req);
1029: if (have < len)
1030: return 0;
1031: p = buffer_ptr(&c->input);
1.292 djm 1032:
1033: need = 1;
1034: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1035: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1036: debug2("channel %d: socks4a request", c->self);
1037: /* ... and needs an extra string (the hostname) */
1038: need = 2;
1039: }
1040: /* Check for terminating NUL on the string(s) */
1.109 markus 1041: for (found = 0, i = len; i < have; i++) {
1042: if (p[i] == '\0') {
1.292 djm 1043: found++;
1044: if (found == need)
1045: break;
1.109 markus 1046: }
1047: if (i > 1024) {
1048: /* the peer is probably sending garbage */
1049: debug("channel %d: decode socks4: too long",
1050: c->self);
1051: return -1;
1052: }
1053: }
1.292 djm 1054: if (found < need)
1.109 markus 1055: return 0;
1.103 markus 1056: buffer_get(&c->input, (char *)&s4_req.version, 1);
1057: buffer_get(&c->input, (char *)&s4_req.command, 1);
1058: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1059: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1060: have = buffer_len(&c->input);
1.103 markus 1061: p = buffer_ptr(&c->input);
1062: len = strlen(p);
1.106 markus 1063: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1064: len++; /* trailing '\0' */
1.103 markus 1065: if (len > have)
1.104 markus 1066: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1067: c->self, len, have);
1068: strlcpy(username, p, sizeof(username));
1069: buffer_consume(&c->input, len);
1070:
1.293 djm 1071: if (c->path != NULL) {
1072: xfree(c->path);
1073: c->path = NULL;
1074: }
1.292 djm 1075: if (need == 1) { /* SOCKS4: one string */
1076: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1077: c->path = xstrdup(host);
1.292 djm 1078: } else { /* SOCKS4A: two strings */
1079: have = buffer_len(&c->input);
1080: p = buffer_ptr(&c->input);
1081: len = strlen(p);
1082: debug2("channel %d: decode socks4a: host %s/%d",
1083: c->self, p, len);
1084: len++; /* trailing '\0' */
1085: if (len > have)
1086: fatal("channel %d: decode socks4a: len %d > have %d",
1087: c->self, len, have);
1.293 djm 1088: if (len > NI_MAXHOST) {
1.292 djm 1089: error("channel %d: hostname \"%.100s\" too long",
1090: c->self, p);
1091: return -1;
1092: }
1.293 djm 1093: c->path = xstrdup(p);
1.292 djm 1094: buffer_consume(&c->input, len);
1095: }
1.103 markus 1096: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1097:
1.194 markus 1098: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1099: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1100:
1.104 markus 1101: if (s4_req.command != 1) {
1.292 djm 1102: debug("channel %d: cannot handle: %s cn %d",
1103: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1104: return -1;
1.103 markus 1105: }
1.104 markus 1106: s4_rsp.version = 0; /* vn: 0 for reply */
1107: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1108: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1109: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1110: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1111: return 1;
1112: }
1113:
1.193 markus 1114: /* try to decode a socks5 header */
1115: #define SSH_SOCKS5_AUTHDONE 0x1000
1116: #define SSH_SOCKS5_NOAUTH 0x00
1117: #define SSH_SOCKS5_IPV4 0x01
1118: #define SSH_SOCKS5_DOMAIN 0x03
1119: #define SSH_SOCKS5_IPV6 0x04
1120: #define SSH_SOCKS5_CONNECT 0x01
1121: #define SSH_SOCKS5_SUCCESS 0x00
1122:
1.259 stevesk 1123: /* ARGSUSED */
1.193 markus 1124: static int
1.237 deraadt 1125: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1126: {
1127: struct {
1128: u_int8_t version;
1129: u_int8_t command;
1130: u_int8_t reserved;
1131: u_int8_t atyp;
1132: } s5_req, s5_rsp;
1133: u_int16_t dest_port;
1.293 djm 1134: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1135: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1136:
1137: debug2("channel %d: decode socks5", c->self);
1138: p = buffer_ptr(&c->input);
1139: if (p[0] != 0x05)
1140: return -1;
1141: have = buffer_len(&c->input);
1142: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1143: /* format: ver | nmethods | methods */
1.198 djm 1144: if (have < 2)
1.193 markus 1145: return 0;
1146: nmethods = p[1];
1147: if (have < nmethods + 2)
1148: return 0;
1149: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1150: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1151: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1152: found = 1;
1153: break;
1154: }
1155: }
1156: if (!found) {
1157: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1158: c->self);
1159: return -1;
1160: }
1161: buffer_consume(&c->input, nmethods + 2);
1162: buffer_put_char(&c->output, 0x05); /* version */
1163: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1164: FD_SET(c->sock, writeset);
1165: c->flags |= SSH_SOCKS5_AUTHDONE;
1166: debug2("channel %d: socks5 auth done", c->self);
1167: return 0; /* need more */
1168: }
1169: debug2("channel %d: socks5 post auth", c->self);
1170: if (have < sizeof(s5_req)+1)
1171: return 0; /* need more */
1.247 deraadt 1172: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1173: if (s5_req.version != 0x05 ||
1174: s5_req.command != SSH_SOCKS5_CONNECT ||
1175: s5_req.reserved != 0x00) {
1.194 markus 1176: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1177: return -1;
1178: }
1.213 deraadt 1179: switch (s5_req.atyp){
1.193 markus 1180: case SSH_SOCKS5_IPV4:
1181: addrlen = 4;
1182: af = AF_INET;
1183: break;
1184: case SSH_SOCKS5_DOMAIN:
1185: addrlen = p[sizeof(s5_req)];
1186: af = -1;
1187: break;
1188: case SSH_SOCKS5_IPV6:
1189: addrlen = 16;
1190: af = AF_INET6;
1191: break;
1192: default:
1.194 markus 1193: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1194: return -1;
1195: }
1.252 djm 1196: need = sizeof(s5_req) + addrlen + 2;
1197: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1198: need++;
1199: if (have < need)
1.193 markus 1200: return 0;
1201: buffer_consume(&c->input, sizeof(s5_req));
1202: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1203: buffer_consume(&c->input, 1); /* host string length */
1204: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1205: buffer_get(&c->input, (char *)&dest_port, 2);
1206: dest_addr[addrlen] = '\0';
1.293 djm 1207: if (c->path != NULL) {
1208: xfree(c->path);
1209: c->path = NULL;
1210: }
1211: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1212: if (addrlen >= NI_MAXHOST) {
1.293 djm 1213: error("channel %d: dynamic request: socks5 hostname "
1214: "\"%.100s\" too long", c->self, dest_addr);
1215: return -1;
1216: }
1217: c->path = xstrdup(dest_addr);
1218: } else {
1219: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1220: return -1;
1221: c->path = xstrdup(ntop);
1222: }
1.193 markus 1223: c->host_port = ntohs(dest_port);
1.198 djm 1224:
1.194 markus 1225: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1226: c->self, c->path, c->host_port, s5_req.command);
1227:
1228: s5_rsp.version = 0x05;
1229: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1230: s5_rsp.reserved = 0; /* ignored */
1231: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1232: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1233: dest_port = 0; /* ignored */
1234:
1.246 deraadt 1235: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1236: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1237: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1238: return 1;
1.301 dtucker 1239: }
1240:
1241: Channel *
1.302 djm 1242: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1243: int in, int out)
1.301 dtucker 1244: {
1245: Channel *c;
1246:
1247: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1248: port_to_connect);
1249:
1250: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1251: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1252: 0, "stdio-forward", /*nonblock*/0);
1253:
1254: c->path = xstrdup(host_to_connect);
1255: c->host_port = port_to_connect;
1256: c->listening_port = 0;
1257: c->force_drain = 1;
1258:
1259: channel_register_fds(c, in, out, -1, 0, 1, 0);
1260: port_open_helper(c, "direct-tcpip");
1261:
1262: return c;
1.193 markus 1263: }
1264:
1.104 markus 1265: /* dynamic port forwarding */
1.127 itojun 1266: static void
1.237 deraadt 1267: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1268: {
1269: u_char *p;
1.217 djm 1270: u_int have;
1271: int ret;
1.103 markus 1272:
1.104 markus 1273: have = buffer_len(&c->input);
1274: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1275: /* buffer_dump(&c->input); */
1.104 markus 1276: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1277: if (have < 3) {
1.104 markus 1278: /* need more */
1279: FD_SET(c->sock, readset);
1280: return;
1281: }
1282: /* try to guess the protocol */
1283: p = buffer_ptr(&c->input);
1284: switch (p[0]) {
1285: case 0x04:
1286: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1287: break;
1288: case 0x05:
1289: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1290: break;
1291: default:
1292: ret = -1;
1293: break;
1294: }
1295: if (ret < 0) {
1.113 markus 1296: chan_mark_dead(c);
1.104 markus 1297: } else if (ret == 0) {
1298: debug2("channel %d: pre_dynamic: need more", c->self);
1299: /* need more */
1300: FD_SET(c->sock, readset);
1301: } else {
1302: /* switch to the next state */
1303: c->type = SSH_CHANNEL_OPENING;
1304: port_open_helper(c, "direct-tcpip");
1305: }
1.103 markus 1306: }
1307:
1.41 markus 1308: /* This is our fake X11 server socket. */
1.259 stevesk 1309: /* ARGSUSED */
1.127 itojun 1310: static void
1.237 deraadt 1311: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1312: {
1.113 markus 1313: Channel *nc;
1.285 djm 1314: struct sockaddr_storage addr;
1.162 stevesk 1315: int newsock;
1.41 markus 1316: socklen_t addrlen;
1.85 markus 1317: char buf[16384], *remote_ipaddr;
1.51 markus 1318: int remote_port;
1.25 markus 1319:
1.41 markus 1320: if (FD_ISSET(c->sock, readset)) {
1321: debug("X11 connection requested.");
1322: addrlen = sizeof(addr);
1.285 djm 1323: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1324: if (c->single_connection) {
1.194 markus 1325: debug2("single_connection: closing X11 listener.");
1.149 markus 1326: channel_close_fd(&c->sock);
1327: chan_mark_dead(c);
1328: }
1.41 markus 1329: if (newsock < 0) {
1330: error("accept: %.100s", strerror(errno));
1331: return;
1332: }
1.162 stevesk 1333: set_nodelay(newsock);
1.85 markus 1334: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1335: remote_port = get_peer_port(newsock);
1.41 markus 1336: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1337: remote_ipaddr, remote_port);
1.51 markus 1338:
1.113 markus 1339: nc = channel_new("accepted x11 socket",
1.51 markus 1340: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1341: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1342: if (compat20) {
1343: packet_start(SSH2_MSG_CHANNEL_OPEN);
1344: packet_put_cstring("x11");
1.113 markus 1345: packet_put_int(nc->self);
1.149 markus 1346: packet_put_int(nc->local_window_max);
1347: packet_put_int(nc->local_maxpacket);
1.85 markus 1348: /* originator ipaddr and port */
1349: packet_put_cstring(remote_ipaddr);
1.57 markus 1350: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1351: debug2("ssh2 x11 bug compat mode");
1.57 markus 1352: } else {
1353: packet_put_int(remote_port);
1354: }
1.51 markus 1355: packet_send();
1356: } else {
1357: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1358: packet_put_int(nc->self);
1.121 markus 1359: if (packet_get_protocol_flags() &
1360: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1361: packet_put_cstring(buf);
1.51 markus 1362: packet_send();
1363: }
1.85 markus 1364: xfree(remote_ipaddr);
1.41 markus 1365: }
1366: }
1.25 markus 1367:
1.127 itojun 1368: static void
1.103 markus 1369: port_open_helper(Channel *c, char *rtype)
1370: {
1371: int direct;
1372: char buf[1024];
1373: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1374: int remote_port = get_peer_port(c->sock);
1.303 djm 1375:
1376: if (remote_port == -1) {
1377: /* Fake addr/port to appease peers that validate it (Tectia) */
1378: xfree(remote_ipaddr);
1379: remote_ipaddr = xstrdup("127.0.0.1");
1380: remote_port = 65535;
1381: }
1.103 markus 1382:
1383: direct = (strcmp(rtype, "direct-tcpip") == 0);
1384:
1385: snprintf(buf, sizeof buf,
1386: "%s: listening port %d for %.100s port %d, "
1387: "connect from %.200s port %d",
1388: rtype, c->listening_port, c->path, c->host_port,
1389: remote_ipaddr, remote_port);
1390:
1391: xfree(c->remote_name);
1392: c->remote_name = xstrdup(buf);
1393:
1394: if (compat20) {
1395: packet_start(SSH2_MSG_CHANNEL_OPEN);
1396: packet_put_cstring(rtype);
1397: packet_put_int(c->self);
1398: packet_put_int(c->local_window_max);
1399: packet_put_int(c->local_maxpacket);
1400: if (direct) {
1401: /* target host, port */
1402: packet_put_cstring(c->path);
1403: packet_put_int(c->host_port);
1404: } else {
1405: /* listen address, port */
1406: packet_put_cstring(c->path);
1407: packet_put_int(c->listening_port);
1408: }
1409: /* originator host and port */
1410: packet_put_cstring(remote_ipaddr);
1.216 markus 1411: packet_put_int((u_int)remote_port);
1.103 markus 1412: packet_send();
1413: } else {
1414: packet_start(SSH_MSG_PORT_OPEN);
1415: packet_put_int(c->self);
1416: packet_put_cstring(c->path);
1417: packet_put_int(c->host_port);
1.121 markus 1418: if (packet_get_protocol_flags() &
1419: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1420: packet_put_cstring(c->remote_name);
1421: packet_send();
1422: }
1423: xfree(remote_ipaddr);
1424: }
1425:
1.226 djm 1426: static void
1427: channel_set_reuseaddr(int fd)
1428: {
1429: int on = 1;
1430:
1431: /*
1432: * Set socket options.
1433: * Allow local port reuse in TIME_WAIT.
1434: */
1435: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1436: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1437: }
1438:
1.41 markus 1439: /*
1440: * This socket is listening for connections to a forwarded TCP/IP port.
1441: */
1.259 stevesk 1442: /* ARGSUSED */
1.127 itojun 1443: static void
1.237 deraadt 1444: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1445: {
1.103 markus 1446: Channel *nc;
1.285 djm 1447: struct sockaddr_storage addr;
1.113 markus 1448: int newsock, nextstate;
1.41 markus 1449: socklen_t addrlen;
1.103 markus 1450: char *rtype;
1.73 markus 1451:
1.41 markus 1452: if (FD_ISSET(c->sock, readset)) {
1453: debug("Connection to port %d forwarding "
1454: "to %.100s port %d requested.",
1455: c->listening_port, c->path, c->host_port);
1.103 markus 1456:
1.137 markus 1457: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1458: nextstate = SSH_CHANNEL_OPENING;
1459: rtype = "forwarded-tcpip";
1460: } else {
1461: if (c->host_port == 0) {
1462: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1463: rtype = "dynamic-tcpip";
1.137 markus 1464: } else {
1465: nextstate = SSH_CHANNEL_OPENING;
1466: rtype = "direct-tcpip";
1467: }
1468: }
1.103 markus 1469:
1.41 markus 1470: addrlen = sizeof(addr);
1.285 djm 1471: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1472: if (newsock < 0) {
1473: error("accept: %.100s", strerror(errno));
1474: return;
1475: }
1.169 stevesk 1476: set_nodelay(newsock);
1.190 markus 1477: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1478: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1479: nc->listening_port = c->listening_port;
1480: nc->host_port = c->host_port;
1.293 djm 1481: if (c->path != NULL)
1482: nc->path = xstrdup(c->path);
1.103 markus 1483:
1.299 markus 1484: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1485: port_open_helper(nc, rtype);
1.41 markus 1486: }
1487: }
1.25 markus 1488:
1.41 markus 1489: /*
1490: * This is the authentication agent socket listening for connections from
1491: * clients.
1492: */
1.259 stevesk 1493: /* ARGSUSED */
1.127 itojun 1494: static void
1.237 deraadt 1495: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1496: {
1.113 markus 1497: Channel *nc;
1498: int newsock;
1.285 djm 1499: struct sockaddr_storage addr;
1.41 markus 1500: socklen_t addrlen;
1.25 markus 1501:
1.41 markus 1502: if (FD_ISSET(c->sock, readset)) {
1503: addrlen = sizeof(addr);
1.285 djm 1504: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1505: if (newsock < 0) {
1506: error("accept from auth socket: %.100s", strerror(errno));
1507: return;
1508: }
1.113 markus 1509: nc = channel_new("accepted auth socket",
1.73 markus 1510: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1511: c->local_window_max, c->local_maxpacket,
1.190 markus 1512: 0, "accepted auth socket", 1);
1.73 markus 1513: if (compat20) {
1514: packet_start(SSH2_MSG_CHANNEL_OPEN);
1515: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1516: packet_put_int(nc->self);
1.73 markus 1517: packet_put_int(c->local_window_max);
1518: packet_put_int(c->local_maxpacket);
1519: } else {
1520: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1521: packet_put_int(nc->self);
1.73 markus 1522: }
1.41 markus 1523: packet_send();
1524: }
1525: }
1.25 markus 1526:
1.259 stevesk 1527: /* ARGSUSED */
1.127 itojun 1528: static void
1.237 deraadt 1529: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1530: {
1.276 djm 1531: int err = 0, sock;
1.129 stevesk 1532: socklen_t sz = sizeof(err);
1.114 markus 1533:
1.75 markus 1534: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1535: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1536: err = errno;
1537: error("getsockopt SO_ERROR failed");
1538: }
1539: if (err == 0) {
1.276 djm 1540: debug("channel %d: connected to %s port %d",
1541: c->self, c->connect_ctx.host, c->connect_ctx.port);
1542: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1543: c->type = SSH_CHANNEL_OPEN;
1544: if (compat20) {
1545: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1546: packet_put_int(c->remote_id);
1547: packet_put_int(c->self);
1548: packet_put_int(c->local_window);
1549: packet_put_int(c->local_maxpacket);
1550: } else {
1551: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1552: packet_put_int(c->remote_id);
1553: packet_put_int(c->self);
1554: }
1.75 markus 1555: } else {
1.276 djm 1556: debug("channel %d: connection failed: %s",
1.114 markus 1557: c->self, strerror(err));
1.276 djm 1558: /* Try next address, if any */
1559: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1560: close(c->sock);
1561: c->sock = c->rfd = c->wfd = sock;
1562: channel_max_fd = channel_find_maxfd();
1563: return;
1564: }
1565: /* Exhausted all addresses */
1566: error("connect_to %.100s port %d: failed.",
1567: c->connect_ctx.host, c->connect_ctx.port);
1568: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1569: if (compat20) {
1570: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1571: packet_put_int(c->remote_id);
1572: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1573: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1574: packet_put_cstring(strerror(err));
1575: packet_put_cstring("");
1576: }
1.75 markus 1577: } else {
1.114 markus 1578: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1579: packet_put_int(c->remote_id);
1.75 markus 1580: }
1.114 markus 1581: chan_mark_dead(c);
1.75 markus 1582: }
1.114 markus 1583: packet_send();
1.75 markus 1584: }
1585: }
1586:
1.259 stevesk 1587: /* ARGSUSED */
1.127 itojun 1588: static int
1.237 deraadt 1589: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1590: {
1.214 markus 1591: char buf[CHAN_RBUF];
1.41 markus 1592: int len;
1.25 markus 1593:
1.118 markus 1594: if (c->rfd != -1 &&
1.41 markus 1595: FD_ISSET(c->rfd, readset)) {
1596: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1597: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1598: return 1;
1.41 markus 1599: if (len <= 0) {
1.194 markus 1600: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1601: c->self, c->rfd, len);
1.104 markus 1602: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1603: debug2("channel %d: not open", c->self);
1.113 markus 1604: chan_mark_dead(c);
1.103 markus 1605: return -1;
1.104 markus 1606: } else if (compat13) {
1.158 markus 1607: buffer_clear(&c->output);
1.41 markus 1608: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1609: debug2("channel %d: input draining.", c->self);
1.25 markus 1610: } else {
1.41 markus 1611: chan_read_failed(c);
1.25 markus 1612: }
1.41 markus 1613: return -1;
1614: }
1.143 deraadt 1615: if (c->input_filter != NULL) {
1.66 markus 1616: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1617: debug2("channel %d: filter stops", c->self);
1.65 markus 1618: chan_read_failed(c);
1619: }
1.228 reyk 1620: } else if (c->datagram) {
1621: buffer_put_string(&c->input, buf, len);
1.65 markus 1622: } else {
1623: buffer_append(&c->input, buf, len);
1624: }
1.41 markus 1625: }
1626: return 1;
1627: }
1.241 deraadt 1628:
1.259 stevesk 1629: /* ARGSUSED */
1.127 itojun 1630: static int
1.237 deraadt 1631: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1632: {
1.95 markus 1633: struct termios tio;
1.231 reyk 1634: u_char *data = NULL, *buf;
1.309 ! djm 1635: u_int dlen, olen = 0;
1.41 markus 1636: int len;
1.25 markus 1637:
1.41 markus 1638: /* Send buffered output data to the socket. */
1.118 markus 1639: if (c->wfd != -1 &&
1.41 markus 1640: FD_ISSET(c->wfd, writeset) &&
1641: buffer_len(&c->output) > 0) {
1.309 ! djm 1642: olen = buffer_len(&c->output);
1.231 reyk 1643: if (c->output_filter != NULL) {
1644: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1645: debug2("channel %d: filter stops", c->self);
1.232 reyk 1646: if (c->type != SSH_CHANNEL_OPEN)
1647: chan_mark_dead(c);
1648: else
1649: chan_write_failed(c);
1650: return -1;
1.231 reyk 1651: }
1652: } else if (c->datagram) {
1653: buf = data = buffer_get_string(&c->output, &dlen);
1654: } else {
1655: buf = data = buffer_ptr(&c->output);
1656: dlen = buffer_len(&c->output);
1657: }
1658:
1.228 reyk 1659: if (c->datagram) {
1660: /* ignore truncated writes, datagrams might get lost */
1.231 reyk 1661: len = write(c->wfd, buf, dlen);
1.228 reyk 1662: xfree(data);
1663: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1664: return 1;
1665: if (len <= 0) {
1666: if (c->type != SSH_CHANNEL_OPEN)
1667: chan_mark_dead(c);
1668: else
1669: chan_write_failed(c);
1670: return -1;
1671: }
1.309 ! djm 1672: goto out;
1.228 reyk 1673: }
1.231 reyk 1674:
1675: len = write(c->wfd, buf, dlen);
1.53 markus 1676: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1677: return 1;
1.41 markus 1678: if (len <= 0) {
1.104 markus 1679: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1680: debug2("channel %d: not open", c->self);
1.113 markus 1681: chan_mark_dead(c);
1.104 markus 1682: return -1;
1683: } else if (compat13) {
1.158 markus 1684: buffer_clear(&c->output);
1.194 markus 1685: debug2("channel %d: input draining.", c->self);
1.41 markus 1686: c->type = SSH_CHANNEL_INPUT_DRAINING;
1687: } else {
1688: chan_write_failed(c);
1689: }
1690: return -1;
1.91 markus 1691: }
1.231 reyk 1692: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1693: if (tcgetattr(c->wfd, &tio) == 0 &&
1694: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1695: /*
1696: * Simulate echo to reduce the impact of
1.96 markus 1697: * traffic analysis. We need to match the
1.95 markus 1698: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1699: * (4 byte channel id + buf)
1.91 markus 1700: */
1.95 markus 1701: packet_send_ignore(4 + len);
1.91 markus 1702: packet_send();
1703: }
1.25 markus 1704: }
1.41 markus 1705: buffer_consume(&c->output, len);
1.44 markus 1706: }
1.309 ! djm 1707: out:
! 1708: if (compat20 && olen > 0)
! 1709: c->local_consumed += olen - buffer_len(&c->output);
1.44 markus 1710: return 1;
1711: }
1.241 deraadt 1712:
1.127 itojun 1713: static int
1.237 deraadt 1714: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1715: {
1.214 markus 1716: char buf[CHAN_RBUF];
1.44 markus 1717: int len;
1718:
1.45 markus 1719: /** XXX handle drain efd, too */
1.44 markus 1720: if (c->efd != -1) {
1721: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1722: FD_ISSET(c->efd, writeset) &&
1723: buffer_len(&c->extended) > 0) {
1724: len = write(c->efd, buffer_ptr(&c->extended),
1725: buffer_len(&c->extended));
1.70 markus 1726: debug2("channel %d: written %d to efd %d",
1.44 markus 1727: c->self, len, c->efd);
1.93 markus 1728: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1729: return 1;
1730: if (len <= 0) {
1731: debug2("channel %d: closing write-efd %d",
1732: c->self, c->efd);
1.132 markus 1733: channel_close_fd(&c->efd);
1.93 markus 1734: } else {
1.44 markus 1735: buffer_consume(&c->extended, len);
1736: c->local_consumed += len;
1737: }
1.306 djm 1738: } else if (c->efd != -1 &&
1739: (c->extended_usage == CHAN_EXTENDED_READ ||
1740: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 1741: FD_ISSET(c->efd, readset)) {
1742: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1743: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1744: c->self, len, c->efd);
1.93 markus 1745: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1746: return 1;
1747: if (len <= 0) {
1748: debug2("channel %d: closing read-efd %d",
1.45 markus 1749: c->self, c->efd);
1.132 markus 1750: channel_close_fd(&c->efd);
1.93 markus 1751: } else {
1.306 djm 1752: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1753: debug3("channel %d: discard efd",
1754: c->self);
1755: } else
1756: buffer_append(&c->extended, buf, len);
1.93 markus 1757: }
1.44 markus 1758: }
1759: }
1760: return 1;
1761: }
1.241 deraadt 1762:
1.259 stevesk 1763: /* ARGSUSED */
1.127 itojun 1764: static int
1.93 markus 1765: channel_check_window(Channel *c)
1.44 markus 1766: {
1.104 markus 1767: if (c->type == SSH_CHANNEL_OPEN &&
1768: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1769: ((c->local_window_max - c->local_window >
1.269 markus 1770: c->local_maxpacket*3) ||
1771: c->local_window < c->local_window_max/2) &&
1.44 markus 1772: c->local_consumed > 0) {
1773: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1774: packet_put_int(c->remote_id);
1775: packet_put_int(c->local_consumed);
1776: packet_send();
1.70 markus 1777: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1778: c->self, c->local_window,
1779: c->local_consumed);
1780: c->local_window += c->local_consumed;
1781: c->local_consumed = 0;
1.1 deraadt 1782: }
1.41 markus 1783: return 1;
1.1 deraadt 1784: }
1785:
1.127 itojun 1786: static void
1.237 deraadt 1787: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1788: {
1789: channel_handle_rfd(c, readset, writeset);
1790: channel_handle_wfd(c, readset, writeset);
1.157 markus 1791: if (!compat20)
1.137 markus 1792: return;
1.44 markus 1793: channel_handle_efd(c, readset, writeset);
1.93 markus 1794: channel_check_window(c);
1.44 markus 1795: }
1796:
1.302 djm 1797: static u_int
1798: read_mux(Channel *c, u_int need)
1799: {
1800: char buf[CHAN_RBUF];
1801: int len;
1802: u_int rlen;
1803:
1804: if (buffer_len(&c->input) < need) {
1805: rlen = need - buffer_len(&c->input);
1806: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1807: if (len <= 0) {
1808: if (errno != EINTR && errno != EAGAIN) {
1809: debug2("channel %d: ctl read<=0 rfd %d len %d",
1810: c->self, c->rfd, len);
1811: chan_read_failed(c);
1812: return 0;
1813: }
1814: } else
1815: buffer_append(&c->input, buf, len);
1816: }
1817: return buffer_len(&c->input);
1818: }
1819:
1820: static void
1821: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1822: {
1823: u_int need;
1824: ssize_t len;
1825:
1826: if (!compat20)
1827: fatal("%s: entered with !compat20", __func__);
1828:
1.304 djm 1829: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1830: (c->istate == CHAN_INPUT_OPEN ||
1831: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1832: /*
1833: * Don't not read past the precise end of packets to
1834: * avoid disrupting fd passing.
1835: */
1836: if (read_mux(c, 4) < 4) /* read header */
1837: return;
1838: need = get_u32(buffer_ptr(&c->input));
1839: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1840: if (need > CHANNEL_MUX_MAX_PACKET) {
1841: debug2("channel %d: packet too big %u > %u",
1842: c->self, CHANNEL_MUX_MAX_PACKET, need);
1843: chan_rcvd_oclose(c);
1844: return;
1845: }
1846: if (read_mux(c, need + 4) < need + 4) /* read body */
1847: return;
1848: if (c->mux_rcb(c) != 0) {
1849: debug("channel %d: mux_rcb failed", c->self);
1850: chan_mark_dead(c);
1851: return;
1852: }
1853: }
1854:
1855: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1856: buffer_len(&c->output) > 0) {
1857: len = write(c->wfd, buffer_ptr(&c->output),
1858: buffer_len(&c->output));
1859: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1860: return;
1861: if (len <= 0) {
1862: chan_mark_dead(c);
1863: return;
1864: }
1865: buffer_consume(&c->output, len);
1866: }
1867: }
1868:
1869: static void
1870: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1871: {
1872: Channel *nc;
1873: struct sockaddr_storage addr;
1874: socklen_t addrlen;
1875: int newsock;
1876: uid_t euid;
1877: gid_t egid;
1878:
1879: if (!FD_ISSET(c->sock, readset))
1880: return;
1881:
1882: debug("multiplexing control connection");
1883:
1884: /*
1885: * Accept connection on control socket
1886: */
1887: memset(&addr, 0, sizeof(addr));
1888: addrlen = sizeof(addr);
1889: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1890: &addrlen)) == -1) {
1891: error("%s accept: %s", __func__, strerror(errno));
1892: return;
1893: }
1894:
1895: if (getpeereid(newsock, &euid, &egid) < 0) {
1896: error("%s getpeereid failed: %s", __func__,
1897: strerror(errno));
1898: close(newsock);
1899: return;
1900: }
1901: if ((euid != 0) && (getuid() != euid)) {
1902: error("multiplex uid mismatch: peer euid %u != uid %u",
1903: (u_int)euid, (u_int)getuid());
1904: close(newsock);
1905: return;
1906: }
1907: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1908: newsock, newsock, -1, c->local_window_max,
1909: c->local_maxpacket, 0, "mux-control", 1);
1910: nc->mux_rcb = c->mux_rcb;
1911: debug3("%s: new mux channel %d fd %d", __func__,
1912: nc->self, nc->sock);
1913: /* establish state */
1914: nc->mux_rcb(nc);
1915: /* mux state transitions must not elicit protocol messages */
1916: nc->flags |= CHAN_LOCAL;
1917: }
1918:
1.259 stevesk 1919: /* ARGSUSED */
1.127 itojun 1920: static void
1.237 deraadt 1921: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1922: {
1.41 markus 1923: int len;
1.180 deraadt 1924:
1.41 markus 1925: /* Send buffered output data to the socket. */
1926: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1927: len = write(c->sock, buffer_ptr(&c->output),
1928: buffer_len(&c->output));
1929: if (len <= 0)
1.158 markus 1930: buffer_clear(&c->output);
1.41 markus 1931: else
1932: buffer_consume(&c->output, len);
1933: }
1934: }
1.25 markus 1935:
1.127 itojun 1936: static void
1.44 markus 1937: channel_handler_init_20(void)
1938: {
1.157 markus 1939: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1940: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1941: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1942: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1943: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1944: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1945: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1946: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 1947: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1948: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1949:
1.157 markus 1950: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1951: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1952: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1953: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1954: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1955: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1956: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 1957: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1958: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1959: }
1960:
1.127 itojun 1961: static void
1.41 markus 1962: channel_handler_init_13(void)
1963: {
1964: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1965: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1966: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1967: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1968: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1969: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1970: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1971: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1972: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1973:
1.157 markus 1974: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1975: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1976: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1977: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1978: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1979: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1980: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1981: }
1.25 markus 1982:
1.127 itojun 1983: static void
1.41 markus 1984: channel_handler_init_15(void)
1985: {
1.157 markus 1986: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1987: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1988: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1989: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1990: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1991: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1992: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1993:
1.41 markus 1994: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1995: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1996: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1997: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1998: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1999: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 2000: }
1.27 markus 2001:
1.127 itojun 2002: static void
1.41 markus 2003: channel_handler_init(void)
2004: {
2005: int i;
1.180 deraadt 2006:
1.148 deraadt 2007: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2008: channel_pre[i] = NULL;
2009: channel_post[i] = NULL;
2010: }
1.44 markus 2011: if (compat20)
2012: channel_handler_init_20();
2013: else if (compat13)
1.41 markus 2014: channel_handler_init_13();
2015: else
2016: channel_handler_init_15();
2017: }
1.25 markus 2018:
1.140 markus 2019: /* gc dead channels */
2020: static void
2021: channel_garbage_collect(Channel *c)
2022: {
2023: if (c == NULL)
2024: return;
2025: if (c->detach_user != NULL) {
1.225 djm 2026: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2027: return;
1.194 markus 2028: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2029: c->detach_user(c->self, NULL);
2030: /* if we still have a callback */
2031: if (c->detach_user != NULL)
2032: return;
1.194 markus 2033: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2034: }
2035: if (!chan_is_dead(c, 1))
2036: return;
1.194 markus 2037: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2038: channel_free(c);
2039: }
2040:
1.127 itojun 2041: static void
1.237 deraadt 2042: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 2043: {
2044: static int did_init = 0;
1.299 markus 2045: u_int i, oalloc;
1.41 markus 2046: Channel *c;
1.25 markus 2047:
1.41 markus 2048: if (!did_init) {
2049: channel_handler_init();
2050: did_init = 1;
2051: }
1.299 markus 2052: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2053: c = channels[i];
2054: if (c == NULL)
1.41 markus 2055: continue;
1.299 markus 2056: if (c->delayed) {
2057: if (ftab == channel_pre)
2058: c->delayed = 0;
2059: else
2060: continue;
2061: }
1.118 markus 2062: if (ftab[c->type] != NULL)
2063: (*ftab[c->type])(c, readset, writeset);
1.140 markus 2064: channel_garbage_collect(c);
1.1 deraadt 2065: }
2066: }
2067:
1.121 markus 2068: /*
2069: * Allocate/update select bitmasks and add any bits relevant to channels in
2070: * select bitmasks.
2071: */
1.49 markus 2072: void
1.100 markus 2073: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 2074: u_int *nallocp, int rekeying)
1.41 markus 2075: {
1.243 djm 2076: u_int n, sz, nfdset;
1.84 markus 2077:
2078: n = MAX(*maxfdp, channel_max_fd);
2079:
1.243 djm 2080: nfdset = howmany(n+1, NFDBITS);
2081: /* Explicitly test here, because xrealloc isn't always called */
2082: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2083: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2084: sz = nfdset * sizeof(fd_mask);
2085:
1.132 markus 2086: /* perhaps check sz < nalloc/2 and shrink? */
2087: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2088: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2089: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2090: *nallocp = sz;
1.84 markus 2091: }
1.132 markus 2092: *maxfdp = n;
1.84 markus 2093: memset(*readsetp, 0, sz);
2094: memset(*writesetp, 0, sz);
2095:
1.100 markus 2096: if (!rekeying)
2097: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 2098: }
2099:
1.121 markus 2100: /*
2101: * After select, perform any appropriate operations for channels which have
2102: * events pending.
2103: */
1.49 markus 2104: void
1.237 deraadt 2105: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2106: {
2107: channel_handler(channel_post, readset, writeset);
2108: }
2109:
1.121 markus 2110:
1.84 markus 2111: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2112: void
1.142 itojun 2113: channel_output_poll(void)
1.1 deraadt 2114: {
1.41 markus 2115: Channel *c;
1.209 avsm 2116: u_int i, len;
1.1 deraadt 2117:
1.25 markus 2118: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2119: c = channels[i];
2120: if (c == NULL)
2121: continue;
1.37 markus 2122:
1.121 markus 2123: /*
2124: * We are only interested in channels that can have buffered
2125: * incoming data.
2126: */
1.37 markus 2127: if (compat13) {
1.41 markus 2128: if (c->type != SSH_CHANNEL_OPEN &&
2129: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2130: continue;
2131: } else {
1.41 markus 2132: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2133: continue;
2134: }
1.46 markus 2135: if (compat20 &&
2136: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2137: /* XXX is this true? */
1.140 markus 2138: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2139: continue;
2140: }
1.25 markus 2141:
2142: /* Get the amount of buffered data for this channel. */
1.93 markus 2143: if ((c->istate == CHAN_INPUT_OPEN ||
2144: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2145: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2146: if (c->datagram) {
2147: if (len > 0) {
2148: u_char *data;
2149: u_int dlen;
2150:
2151: data = buffer_get_string(&c->input,
2152: &dlen);
1.309 ! djm 2153: if (dlen > c->remote_window ||
! 2154: dlen > c->remote_maxpacket) {
! 2155: debug("channel %d: datagram "
! 2156: "too big for channel",
! 2157: c->self);
! 2158: xfree(data);
! 2159: continue;
! 2160: }
1.228 reyk 2161: packet_start(SSH2_MSG_CHANNEL_DATA);
2162: packet_put_int(c->remote_id);
2163: packet_put_string(data, dlen);
2164: packet_send();
2165: c->remote_window -= dlen + 4;
2166: xfree(data);
2167: }
2168: continue;
2169: }
1.121 markus 2170: /*
2171: * Send some data for the other side over the secure
2172: * connection.
2173: */
1.44 markus 2174: if (compat20) {
2175: if (len > c->remote_window)
2176: len = c->remote_window;
2177: if (len > c->remote_maxpacket)
2178: len = c->remote_maxpacket;
1.25 markus 2179: } else {
1.44 markus 2180: if (packet_is_interactive()) {
2181: if (len > 1024)
2182: len = 512;
2183: } else {
2184: /* Keep the packets at reasonable size. */
2185: if (len > packet_get_maxsize()/2)
2186: len = packet_get_maxsize()/2;
2187: }
1.25 markus 2188: }
1.41 markus 2189: if (len > 0) {
1.44 markus 2190: packet_start(compat20 ?
2191: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2192: packet_put_int(c->remote_id);
2193: packet_put_string(buffer_ptr(&c->input), len);
2194: packet_send();
2195: buffer_consume(&c->input, len);
2196: c->remote_window -= len;
2197: }
2198: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2199: if (compat13)
2200: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2201: /*
2202: * input-buffer is empty and read-socket shutdown:
1.172 markus 2203: * tell peer, that we will not send more data: send IEOF.
2204: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2205: */
1.172 markus 2206: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2207: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2208: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2209: else
2210: chan_ibuf_empty(c);
1.25 markus 2211: }
1.44 markus 2212: /* Send extended data, i.e. stderr */
2213: if (compat20 &&
1.172 markus 2214: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2215: c->remote_window > 0 &&
2216: (len = buffer_len(&c->extended)) > 0 &&
2217: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2218: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2219: c->self, c->remote_window, buffer_len(&c->extended),
2220: c->extended_usage);
1.44 markus 2221: if (len > c->remote_window)
2222: len = c->remote_window;
2223: if (len > c->remote_maxpacket)
2224: len = c->remote_maxpacket;
2225: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2226: packet_put_int(c->remote_id);
2227: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2228: packet_put_string(buffer_ptr(&c->extended), len);
2229: packet_send();
2230: buffer_consume(&c->extended, len);
2231: c->remote_window -= len;
1.93 markus 2232: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2233: }
1.25 markus 2234: }
1.1 deraadt 2235: }
2236:
1.121 markus 2237:
2238: /* -- protocol input */
1.249 djm 2239:
2240: /* ARGSUSED */
1.49 markus 2241: void
1.154 markus 2242: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2243: {
1.37 markus 2244: int id;
1.25 markus 2245: char *data;
1.309 ! djm 2246: u_int data_len, win_len;
1.41 markus 2247: Channel *c;
1.25 markus 2248:
2249: /* Get the channel number and verify it. */
1.37 markus 2250: id = packet_get_int();
1.41 markus 2251: c = channel_lookup(id);
2252: if (c == NULL)
1.37 markus 2253: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2254:
2255: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2256: if (c->type != SSH_CHANNEL_OPEN &&
2257: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2258: return;
2259:
1.25 markus 2260: /* Get the data. */
1.274 markus 2261: data = packet_get_string_ptr(&data_len);
1.309 ! djm 2262: win_len = data_len;
! 2263: if (c->datagram)
! 2264: win_len += 4; /* string length header */
1.200 markus 2265:
2266: /*
2267: * Ignore data for protocol > 1.3 if output end is no longer open.
2268: * For protocol 2 the sending side is reducing its window as it sends
2269: * data, so we must 'fake' consumption of the data in order to ensure
2270: * that window updates are sent back. Otherwise the connection might
2271: * deadlock.
2272: */
2273: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2274: if (compat20) {
1.309 ! djm 2275: c->local_window -= win_len;
! 2276: c->local_consumed += win_len;
1.200 markus 2277: }
2278: return;
2279: }
1.41 markus 2280:
1.143 deraadt 2281: if (compat20) {
1.309 ! djm 2282: if (win_len > c->local_maxpacket) {
1.188 itojun 2283: logit("channel %d: rcvd big packet %d, maxpack %d",
1.309 ! djm 2284: c->self, win_len, c->local_maxpacket);
1.44 markus 2285: }
1.309 ! djm 2286: if (win_len > c->local_window) {
1.188 itojun 2287: logit("channel %d: rcvd too much data %d, win %d",
1.309 ! djm 2288: c->self, win_len, c->local_window);
1.44 markus 2289: return;
2290: }
1.309 ! djm 2291: c->local_window -= win_len;
1.44 markus 2292: }
1.228 reyk 2293: if (c->datagram)
2294: buffer_put_string(&c->output, data, data_len);
2295: else
2296: buffer_append(&c->output, data, data_len);
1.274 markus 2297: packet_check_eom();
1.1 deraadt 2298: }
1.121 markus 2299:
1.249 djm 2300: /* ARGSUSED */
1.49 markus 2301: void
1.154 markus 2302: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2303: {
2304: int id;
2305: char *data;
1.177 markus 2306: u_int data_len, tcode;
1.44 markus 2307: Channel *c;
2308:
2309: /* Get the channel number and verify it. */
2310: id = packet_get_int();
2311: c = channel_lookup(id);
2312:
2313: if (c == NULL)
2314: packet_disconnect("Received extended_data for bad channel %d.", id);
2315: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2316: logit("channel %d: ext data for non open", id);
1.44 markus 2317: return;
1.172 markus 2318: }
2319: if (c->flags & CHAN_EOF_RCVD) {
2320: if (datafellows & SSH_BUG_EXTEOF)
2321: debug("channel %d: accepting ext data after eof", id);
2322: else
2323: packet_disconnect("Received extended_data after EOF "
2324: "on channel %d.", id);
1.44 markus 2325: }
2326: tcode = packet_get_int();
2327: if (c->efd == -1 ||
2328: c->extended_usage != CHAN_EXTENDED_WRITE ||
2329: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2330: logit("channel %d: bad ext data", c->self);
1.44 markus 2331: return;
2332: }
2333: data = packet_get_string(&data_len);
1.152 markus 2334: packet_check_eom();
1.44 markus 2335: if (data_len > c->local_window) {
1.188 itojun 2336: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2337: c->self, data_len, c->local_window);
2338: xfree(data);
2339: return;
2340: }
1.70 markus 2341: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2342: c->local_window -= data_len;
2343: buffer_append(&c->extended, data, data_len);
2344: xfree(data);
2345: }
2346:
1.249 djm 2347: /* ARGSUSED */
1.49 markus 2348: void
1.154 markus 2349: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2350: {
2351: int id;
2352: Channel *c;
2353:
2354: id = packet_get_int();
1.152 markus 2355: packet_check_eom();
1.41 markus 2356: c = channel_lookup(id);
2357: if (c == NULL)
2358: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2359: chan_rcvd_ieof(c);
1.133 markus 2360:
2361: /* XXX force input close */
1.156 markus 2362: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2363: debug("channel %d: FORCE input drain", c->self);
2364: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2365: if (buffer_len(&c->input) == 0)
2366: chan_ibuf_empty(c);
1.133 markus 2367: }
2368:
1.41 markus 2369: }
1.1 deraadt 2370:
1.249 djm 2371: /* ARGSUSED */
1.49 markus 2372: void
1.154 markus 2373: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2374: {
1.41 markus 2375: int id;
2376: Channel *c;
1.1 deraadt 2377:
1.41 markus 2378: id = packet_get_int();
1.152 markus 2379: packet_check_eom();
1.41 markus 2380: c = channel_lookup(id);
2381: if (c == NULL)
2382: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2383:
2384: /*
2385: * Send a confirmation that we have closed the channel and no more
2386: * data is coming for it.
2387: */
1.25 markus 2388: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2389: packet_put_int(c->remote_id);
1.25 markus 2390: packet_send();
2391:
1.27 markus 2392: /*
2393: * If the channel is in closed state, we have sent a close request,
2394: * and the other side will eventually respond with a confirmation.
2395: * Thus, we cannot free the channel here, because then there would be
2396: * no-one to receive the confirmation. The channel gets freed when
2397: * the confirmation arrives.
2398: */
1.41 markus 2399: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2400: /*
2401: * Not a closed channel - mark it as draining, which will
2402: * cause it to be freed later.
2403: */
1.158 markus 2404: buffer_clear(&c->input);
1.41 markus 2405: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2406: }
1.1 deraadt 2407: }
2408:
1.41 markus 2409: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2410: /* ARGSUSED */
1.49 markus 2411: void
1.154 markus 2412: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2413: {
2414: int id = packet_get_int();
2415: Channel *c = channel_lookup(id);
1.151 markus 2416:
1.152 markus 2417: packet_check_eom();
1.41 markus 2418: if (c == NULL)
2419: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2420: chan_rcvd_oclose(c);
2421: }
1.1 deraadt 2422:
1.249 djm 2423: /* ARGSUSED */
1.49 markus 2424: void
1.154 markus 2425: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2426: {
1.41 markus 2427: int id = packet_get_int();
2428: Channel *c = channel_lookup(id);
1.1 deraadt 2429:
1.152 markus 2430: packet_check_eom();
1.41 markus 2431: if (c == NULL)
2432: packet_disconnect("Received close confirmation for "
2433: "out-of-range channel %d.", id);
2434: if (c->type != SSH_CHANNEL_CLOSED)
2435: packet_disconnect("Received close confirmation for "
2436: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2437: channel_free(c);
1.1 deraadt 2438: }
2439:
1.249 djm 2440: /* ARGSUSED */
1.49 markus 2441: void
1.154 markus 2442: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2443: {
1.41 markus 2444: int id, remote_id;
2445: Channel *c;
1.1 deraadt 2446:
1.41 markus 2447: id = packet_get_int();
2448: c = channel_lookup(id);
1.25 markus 2449:
1.41 markus 2450: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2451: packet_disconnect("Received open confirmation for "
2452: "non-opening channel %d.", id);
2453: remote_id = packet_get_int();
1.27 markus 2454: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2455: c->remote_id = remote_id;
2456: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2457:
2458: if (compat20) {
2459: c->remote_window = packet_get_int();
2460: c->remote_maxpacket = packet_get_int();
1.275 djm 2461: if (c->open_confirm) {
1.70 markus 2462: debug2("callback start");
1.304 djm 2463: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2464: debug2("callback done");
1.44 markus 2465: }
1.194 markus 2466: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2467: c->remote_window, c->remote_maxpacket);
2468: }
1.152 markus 2469: packet_check_eom();
1.1 deraadt 2470: }
2471:
1.127 itojun 2472: static char *
1.114 markus 2473: reason2txt(int reason)
2474: {
1.143 deraadt 2475: switch (reason) {
1.114 markus 2476: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2477: return "administratively prohibited";
2478: case SSH2_OPEN_CONNECT_FAILED:
2479: return "connect failed";
2480: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2481: return "unknown channel type";
2482: case SSH2_OPEN_RESOURCE_SHORTAGE:
2483: return "resource shortage";
2484: }
1.117 stevesk 2485: return "unknown reason";
1.114 markus 2486: }
2487:
1.249 djm 2488: /* ARGSUSED */
1.49 markus 2489: void
1.154 markus 2490: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2491: {
1.86 markus 2492: int id, reason;
2493: char *msg = NULL, *lang = NULL;
1.41 markus 2494: Channel *c;
2495:
2496: id = packet_get_int();
2497: c = channel_lookup(id);
1.25 markus 2498:
1.41 markus 2499: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2500: packet_disconnect("Received open failure for "
2501: "non-opening channel %d.", id);
1.44 markus 2502: if (compat20) {
1.86 markus 2503: reason = packet_get_int();
1.110 markus 2504: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2505: msg = packet_get_string(NULL);
2506: lang = packet_get_string(NULL);
2507: }
1.188 itojun 2508: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2509: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2510: if (msg != NULL)
2511: xfree(msg);
2512: if (lang != NULL)
2513: xfree(lang);
1.304 djm 2514: if (c->open_confirm) {
2515: debug2("callback start");
2516: c->open_confirm(c->self, 0, c->open_confirm_ctx);
2517: debug2("callback done");
2518: }
1.44 markus 2519: }
1.152 markus 2520: packet_check_eom();
1.291 djm 2521: /* Schedule the channel for cleanup/deletion. */
2522: chan_mark_dead(c);
1.44 markus 2523: }
2524:
1.249 djm 2525: /* ARGSUSED */
1.121 markus 2526: void
1.154 markus 2527: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2528: {
2529: Channel *c;
1.178 markus 2530: int id;
2531: u_int adjust;
1.121 markus 2532:
2533: if (!compat20)
2534: return;
2535:
2536: /* Get the channel number and verify it. */
2537: id = packet_get_int();
2538: c = channel_lookup(id);
1.1 deraadt 2539:
1.229 markus 2540: if (c == NULL) {
2541: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2542: return;
2543: }
2544: adjust = packet_get_int();
1.152 markus 2545: packet_check_eom();
1.178 markus 2546: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2547: c->remote_window += adjust;
2548: }
1.1 deraadt 2549:
1.249 djm 2550: /* ARGSUSED */
1.121 markus 2551: void
1.154 markus 2552: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2553: {
1.121 markus 2554: Channel *c = NULL;
2555: u_short host_port;
2556: char *host, *originator_string;
1.276 djm 2557: int remote_id;
1.121 markus 2558:
2559: remote_id = packet_get_int();
2560: host = packet_get_string(NULL);
2561: host_port = packet_get_int();
1.25 markus 2562:
1.121 markus 2563: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2564: originator_string = packet_get_string(NULL);
2565: } else {
2566: originator_string = xstrdup("unknown (remote did not supply name)");
2567: }
1.152 markus 2568: packet_check_eom();
1.276 djm 2569: c = channel_connect_to(host, host_port,
2570: "connected socket", originator_string);
1.190 markus 2571: xfree(originator_string);
1.276 djm 2572: xfree(host);
1.121 markus 2573: if (c == NULL) {
2574: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2575: packet_put_int(remote_id);
2576: packet_send();
1.276 djm 2577: } else
2578: c->remote_id = remote_id;
1.1 deraadt 2579: }
2580:
1.275 djm 2581: /* ARGSUSED */
2582: void
2583: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2584: {
2585: Channel *c;
2586: struct channel_confirm *cc;
1.289 markus 2587: int id;
1.275 djm 2588:
2589: /* Reset keepalive timeout */
1.296 andreas 2590: packet_set_alive_timeouts(0);
1.275 djm 2591:
1.289 markus 2592: id = packet_get_int();
1.275 djm 2593: packet_check_eom();
2594:
1.289 markus 2595: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2596:
1.289 markus 2597: if ((c = channel_lookup(id)) == NULL) {
2598: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2599: return;
2600: }
2601: ;
2602: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2603: return;
2604: cc->cb(type, c, cc->ctx);
2605: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2606: bzero(cc, sizeof(*cc));
2607: xfree(cc);
2608: }
1.121 markus 2609:
2610: /* -- tcp forwarding */
1.135 markus 2611:
2612: void
2613: channel_set_af(int af)
2614: {
2615: IPv4or6 = af;
2616: }
1.121 markus 2617:
1.160 markus 2618: static int
1.295 djm 2619: channel_setup_fwd_listener(int type, const char *listen_addr,
2620: u_short listen_port, int *allocated_listen_port,
1.160 markus 2621: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2622: {
1.113 markus 2623: Channel *c;
1.226 djm 2624: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2625: struct addrinfo hints, *ai, *aitop;
1.212 djm 2626: const char *host, *addr;
1.35 markus 2627: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2628: in_port_t *lport_p;
1.25 markus 2629:
1.160 markus 2630: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2631: listen_addr : host_to_connect;
1.212 djm 2632: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2633:
1.160 markus 2634: if (host == NULL) {
2635: error("No forward host name.");
1.218 markus 2636: return 0;
1.73 markus 2637: }
1.294 djm 2638: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2639: error("Forward host name too long.");
1.218 markus 2640: return 0;
1.87 markus 2641: }
1.25 markus 2642:
1.28 markus 2643: /*
1.212 djm 2644: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2645: * specified address or wildcard. On the client, a specified bind
2646: * address will always override gateway_ports. On the server, a
2647: * gateway_ports of 1 (``yes'') will override the client's
2648: * specification and force a wildcard bind, whereas a value of 2
2649: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2650: * asked for.
2651: *
2652: * Special-case listen_addrs are:
2653: *
2654: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2655: * "" (empty string), "*" -> wildcard v4/v6
2656: * "localhost" -> loopback v4/v6
2657: */
2658: addr = NULL;
2659: if (listen_addr == NULL) {
2660: /* No address specified: default to gateway_ports setting */
2661: if (gateway_ports)
2662: wildcard = 1;
2663: } else if (gateway_ports || is_client) {
2664: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
1.272 djm 2665: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
1.212 djm 2666: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2667: (!is_client && gateway_ports == 1))
2668: wildcard = 1;
2669: else if (strcmp(listen_addr, "localhost") != 0)
2670: addr = listen_addr;
2671: }
2672:
2673: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2674: type, wildcard, (addr == NULL) ? "NULL" : addr);
2675:
2676: /*
1.35 markus 2677: * getaddrinfo returns a loopback address if the hostname is
2678: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2679: */
1.35 markus 2680: memset(&hints, 0, sizeof(hints));
2681: hints.ai_family = IPv4or6;
1.212 djm 2682: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2683: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2684: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2685: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2686: if (addr == NULL) {
2687: /* This really shouldn't happen */
2688: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2689: ssh_gai_strerror(r));
1.212 djm 2690: } else {
1.218 markus 2691: error("channel_setup_fwd_listener: "
1.271 dtucker 2692: "getaddrinfo(%.64s): %s", addr,
2693: ssh_gai_strerror(r));
1.212 djm 2694: }
1.218 markus 2695: return 0;
1.212 djm 2696: }
1.295 djm 2697: if (allocated_listen_port != NULL)
2698: *allocated_listen_port = 0;
1.35 markus 2699: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2700: switch (ai->ai_family) {
2701: case AF_INET:
2702: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2703: sin_port;
2704: break;
2705: case AF_INET6:
2706: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2707: sin6_port;
2708: break;
2709: default:
1.35 markus 2710: continue;
1.295 djm 2711: }
2712: /*
2713: * If allocating a port for -R forwards, then use the
2714: * same port for all address families.
2715: */
2716: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2717: allocated_listen_port != NULL && *allocated_listen_port > 0)
2718: *lport_p = htons(*allocated_listen_port);
2719:
1.35 markus 2720: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2721: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2722: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2723: continue;
2724: }
2725: /* Create a port to listen for the host. */
1.300 dtucker 2726: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2727: if (sock < 0) {
2728: /* this is no error since kernel may not support ipv6 */
2729: verbose("socket: %.100s", strerror(errno));
2730: continue;
2731: }
1.226 djm 2732:
2733: channel_set_reuseaddr(sock);
1.182 stevesk 2734:
1.295 djm 2735: debug("Local forwarding listening on %s port %s.",
2736: ntop, strport);
1.35 markus 2737:
2738: /* Bind the socket to the address. */
2739: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2740: /* address can be in use ipv6 address is already bound */
2741: verbose("bind: %.100s", strerror(errno));
2742: close(sock);
2743: continue;
2744: }
2745: /* Start listening for connections on the socket. */
1.199 markus 2746: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2747: error("listen: %.100s", strerror(errno));
2748: close(sock);
2749: continue;
2750: }
1.295 djm 2751:
2752: /*
2753: * listen_port == 0 requests a dynamically allocated port -
2754: * record what we got.
2755: */
2756: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2757: allocated_listen_port != NULL &&
2758: *allocated_listen_port == 0) {
2759: *allocated_listen_port = get_sock_port(sock, 1);
2760: debug("Allocated listen port %d",
2761: *allocated_listen_port);
2762: }
2763:
1.35 markus 2764: /* Allocate a channel number for the socket. */
1.121 markus 2765: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2766: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2767: 0, "port listener", 1);
1.293 djm 2768: c->path = xstrdup(host);
1.113 markus 2769: c->host_port = port_to_connect;
2770: c->listening_port = listen_port;
1.35 markus 2771: success = 1;
2772: }
2773: if (success == 0)
1.160 markus 2774: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2775: listen_port);
1.35 markus 2776: freeaddrinfo(aitop);
1.87 markus 2777: return success;
1.25 markus 2778: }
1.1 deraadt 2779:
1.202 djm 2780: int
2781: channel_cancel_rport_listener(const char *host, u_short port)
2782: {
1.209 avsm 2783: u_int i;
2784: int found = 0;
1.202 djm 2785:
1.213 deraadt 2786: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2787: Channel *c = channels[i];
2788:
2789: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
1.293 djm 2790: strcmp(c->path, host) == 0 && c->listening_port == port) {
1.210 djm 2791: debug2("%s: close channel %d", __func__, i);
1.202 djm 2792: channel_free(c);
2793: found = 1;
2794: }
2795: }
2796:
2797: return (found);
2798: }
2799:
1.160 markus 2800: /* protocol local port fwd, used by ssh (and sshd in v1) */
2801: int
1.212 djm 2802: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2803: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2804: {
2805: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2806: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2807: gateway_ports);
1.160 markus 2808: }
2809:
2810: /* protocol v2 remote port fwd, used by sshd */
2811: int
2812: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2813: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2814: {
2815: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2816: listen_address, listen_port, allocated_listen_port,
2817: NULL, 0, gateway_ports);
1.160 markus 2818: }
2819:
1.27 markus 2820: /*
2821: * Initiate forwarding of connections to port "port" on remote host through
2822: * the secure channel to host:port from local side.
2823: */
1.1 deraadt 2824:
1.253 markus 2825: int
1.212 djm 2826: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2827: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2828: {
1.153 markus 2829: int type, success = 0;
1.73 markus 2830:
1.25 markus 2831: /* Send the forward request to the remote side. */
1.44 markus 2832: if (compat20) {
1.212 djm 2833: const char *address_to_bind;
1.267 djm 2834: if (listen_host == NULL) {
2835: if (datafellows & SSH_BUG_RFWD_ADDR)
2836: address_to_bind = "127.0.0.1";
2837: else
2838: address_to_bind = "localhost";
2839: } else if (*listen_host == '\0' ||
2840: strcmp(listen_host, "*") == 0) {
2841: if (datafellows & SSH_BUG_RFWD_ADDR)
2842: address_to_bind = "0.0.0.0";
2843: else
2844: address_to_bind = "";
2845: } else
1.212 djm 2846: address_to_bind = listen_host;
2847:
1.44 markus 2848: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2849: packet_put_cstring("tcpip-forward");
1.173 markus 2850: packet_put_char(1); /* boolean: want reply */
1.44 markus 2851: packet_put_cstring(address_to_bind);
2852: packet_put_int(listen_port);
1.73 markus 2853: packet_send();
2854: packet_write_wait();
2855: /* Assume that server accepts the request */
2856: success = 1;
1.44 markus 2857: } else {
2858: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2859: packet_put_int(listen_port);
2860: packet_put_cstring(host_to_connect);
1.44 markus 2861: packet_put_int(port_to_connect);
2862: packet_send();
2863: packet_write_wait();
1.73 markus 2864:
2865: /* Wait for response from the remote side. */
1.153 markus 2866: type = packet_read();
1.73 markus 2867: switch (type) {
2868: case SSH_SMSG_SUCCESS:
2869: success = 1;
2870: break;
2871: case SSH_SMSG_FAILURE:
2872: break;
2873: default:
2874: /* Unknown packet */
2875: packet_disconnect("Protocol error for port forward request:"
2876: "received packet type %d.", type);
2877: }
2878: }
2879: if (success) {
1.305 djm 2880: /* Record that connection to this host/port is permitted. */
2881: permitted_opens = xrealloc(permitted_opens,
2882: num_permitted_opens + 1, sizeof(*permitted_opens));
1.73 markus 2883: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2884: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2885: permitted_opens[num_permitted_opens].listen_port = listen_port;
2886: num_permitted_opens++;
1.44 markus 2887: }
1.253 markus 2888: return (success ? 0 : -1);
1.1 deraadt 2889: }
2890:
1.27 markus 2891: /*
1.208 deraadt 2892: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2893: * local side.
2894: */
2895: void
1.212 djm 2896: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2897: {
2898: int i;
2899:
2900: if (!compat20)
2901: return;
2902:
2903: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2904: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2905: permitted_opens[i].listen_port == port)
2906: break;
2907: }
2908: if (i >= num_permitted_opens) {
2909: debug("%s: requested forward not found", __func__);
2910: return;
2911: }
2912: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2913: packet_put_cstring("cancel-tcpip-forward");
2914: packet_put_char(0);
1.212 djm 2915: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2916: packet_put_int(port);
2917: packet_send();
2918:
2919: permitted_opens[i].listen_port = 0;
2920: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2921: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2922: permitted_opens[i].host_to_connect = NULL;
2923: }
2924:
2925: /*
1.27 markus 2926: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2927: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2928: * message if there was an error).
1.27 markus 2929: */
1.253 markus 2930: int
1.56 markus 2931: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2932: {
1.31 markus 2933: u_short port, host_port;
1.253 markus 2934: int success = 0;
1.25 markus 2935: char *hostname;
1.1 deraadt 2936:
1.25 markus 2937: /* Get arguments from the packet. */
2938: port = packet_get_int();
2939: hostname = packet_get_string(NULL);
2940: host_port = packet_get_int();
2941:
1.27 markus 2942: /*
2943: * Check that an unprivileged user is not trying to forward a
2944: * privileged port.
2945: */
1.25 markus 2946: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2947: packet_disconnect(
2948: "Requested forwarding of port %d but user is not root.",
2949: port);
2950: if (host_port == 0)
2951: packet_disconnect("Dynamic forwarding denied.");
2952:
1.73 markus 2953: /* Initiate forwarding */
1.253 markus 2954: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2955: host_port, gateway_ports);
1.25 markus 2956:
2957: /* Free the argument string. */
2958: xfree(hostname);
1.253 markus 2959:
2960: return (success ? 0 : -1);
1.1 deraadt 2961: }
2962:
1.99 markus 2963: /*
2964: * Permits opening to any host/port if permitted_opens[] is empty. This is
2965: * usually called by the server, because the user could connect to any port
2966: * anyway, and the server has no way to know but to trust the client anyway.
2967: */
2968: void
1.142 itojun 2969: channel_permit_all_opens(void)
1.99 markus 2970: {
2971: if (num_permitted_opens == 0)
2972: all_opens_permitted = 1;
2973: }
2974:
1.101 markus 2975: void
1.99 markus 2976: channel_add_permitted_opens(char *host, int port)
2977: {
2978: debug("allow port forwarding to host %s port %d", host, port);
2979:
1.305 djm 2980: permitted_opens = xrealloc(permitted_opens,
2981: num_permitted_opens + 1, sizeof(*permitted_opens));
1.99 markus 2982: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2983: permitted_opens[num_permitted_opens].port_to_connect = port;
2984: num_permitted_opens++;
2985:
2986: all_opens_permitted = 0;
2987: }
2988:
1.258 dtucker 2989: int
1.257 dtucker 2990: channel_add_adm_permitted_opens(char *host, int port)
2991: {
1.258 dtucker 2992: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 2993:
1.305 djm 2994: permitted_adm_opens = xrealloc(permitted_adm_opens,
2995: num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
1.257 dtucker 2996: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2997: = xstrdup(host);
2998: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 2999: return ++num_adm_permitted_opens;
1.257 dtucker 3000: }
3001:
3002: void
1.99 markus 3003: channel_clear_permitted_opens(void)
3004: {
3005: int i;
3006:
3007: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3008: if (permitted_opens[i].host_to_connect != NULL)
3009: xfree(permitted_opens[i].host_to_connect);
1.305 djm 3010: if (num_permitted_opens > 0) {
3011: xfree(permitted_opens);
3012: permitted_opens = NULL;
3013: }
1.99 markus 3014: num_permitted_opens = 0;
1.257 dtucker 3015: }
3016:
3017: void
3018: channel_clear_adm_permitted_opens(void)
3019: {
3020: int i;
1.99 markus 3021:
1.257 dtucker 3022: for (i = 0; i < num_adm_permitted_opens; i++)
3023: if (permitted_adm_opens[i].host_to_connect != NULL)
3024: xfree(permitted_adm_opens[i].host_to_connect);
1.305 djm 3025: if (num_adm_permitted_opens > 0) {
3026: xfree(permitted_adm_opens);
3027: permitted_adm_opens = NULL;
3028: }
1.257 dtucker 3029: num_adm_permitted_opens = 0;
1.278 dtucker 3030: }
3031:
3032: void
3033: channel_print_adm_permitted_opens(void)
3034: {
1.286 djm 3035: int i;
1.278 dtucker 3036:
1.290 stevesk 3037: printf("permitopen");
1.288 stevesk 3038: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3039: printf(" any\n");
1.288 stevesk 3040: return;
3041: }
1.278 dtucker 3042: for (i = 0; i < num_adm_permitted_opens; i++)
3043: if (permitted_adm_opens[i].host_to_connect != NULL)
3044: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3045: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3046: printf("\n");
1.99 markus 3047: }
3048:
1.276 djm 3049: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3050: static int
1.276 djm 3051: connect_next(struct channel_connect *cctx)
1.41 markus 3052: {
1.276 djm 3053: int sock, saved_errno;
1.41 markus 3054: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3055:
1.276 djm 3056: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3057: if (cctx->ai->ai_family != AF_INET &&
3058: cctx->ai->ai_family != AF_INET6)
1.41 markus 3059: continue;
1.276 djm 3060: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3061: ntop, sizeof(ntop), strport, sizeof(strport),
3062: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3063: error("connect_next: getnameinfo failed");
1.41 markus 3064: continue;
3065: }
1.300 dtucker 3066: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3067: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3068: if (cctx->ai->ai_next == NULL)
1.186 djm 3069: error("socket: %.100s", strerror(errno));
3070: else
3071: verbose("socket: %.100s", strerror(errno));
1.41 markus 3072: continue;
3073: }
1.205 djm 3074: if (set_nonblock(sock) == -1)
3075: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3076: if (connect(sock, cctx->ai->ai_addr,
3077: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3078: debug("connect_next: host %.100s ([%.100s]:%s): "
3079: "%.100s", cctx->host, ntop, strport,
1.41 markus 3080: strerror(errno));
1.276 djm 3081: saved_errno = errno;
1.41 markus 3082: close(sock);
1.276 djm 3083: errno = saved_errno;
1.89 stevesk 3084: continue; /* fail -- try next */
1.41 markus 3085: }
1.276 djm 3086: debug("connect_next: host %.100s ([%.100s]:%s) "
3087: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3088: cctx->ai = cctx->ai->ai_next;
3089: set_nodelay(sock);
3090: return sock;
3091: }
3092: return -1;
3093: }
1.41 markus 3094:
1.276 djm 3095: static void
3096: channel_connect_ctx_free(struct channel_connect *cctx)
3097: {
3098: xfree(cctx->host);
3099: if (cctx->aitop)
3100: freeaddrinfo(cctx->aitop);
3101: bzero(cctx, sizeof(*cctx));
3102: cctx->host = NULL;
3103: cctx->ai = cctx->aitop = NULL;
3104: }
3105:
3106: /* Return CONNECTING channel to remote host, port */
3107: static Channel *
3108: connect_to(const char *host, u_short port, char *ctype, char *rname)
3109: {
3110: struct addrinfo hints;
3111: int gaierr;
3112: int sock = -1;
3113: char strport[NI_MAXSERV];
3114: struct channel_connect cctx;
3115: Channel *c;
3116:
1.284 djm 3117: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3118: memset(&hints, 0, sizeof(hints));
3119: hints.ai_family = IPv4or6;
3120: hints.ai_socktype = SOCK_STREAM;
3121: snprintf(strport, sizeof strport, "%d", port);
3122: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3123: error("connect_to %.100s: unknown host (%s)", host,
3124: ssh_gai_strerror(gaierr));
3125: return NULL;
1.41 markus 3126: }
1.276 djm 3127:
3128: cctx.host = xstrdup(host);
3129: cctx.port = port;
3130: cctx.ai = cctx.aitop;
3131:
3132: if ((sock = connect_next(&cctx)) == -1) {
3133: error("connect to %.100s port %d failed: %s",
3134: host, port, strerror(errno));
3135: channel_connect_ctx_free(&cctx);
3136: return NULL;
1.41 markus 3137: }
1.276 djm 3138: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3139: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3140: c->connect_ctx = cctx;
3141: return c;
1.41 markus 3142: }
1.99 markus 3143:
1.276 djm 3144: Channel *
3145: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3146: {
3147: int i;
1.99 markus 3148:
1.276 djm 3149: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3150: if (permitted_opens[i].host_to_connect != NULL &&
1.276 djm 3151: permitted_opens[i].listen_port == listen_port) {
1.99 markus 3152: return connect_to(
1.73 markus 3153: permitted_opens[i].host_to_connect,
1.276 djm 3154: permitted_opens[i].port_to_connect, ctype, rname);
3155: }
3156: }
1.74 markus 3157: error("WARNING: Server requests forwarding for unknown listen_port %d",
3158: listen_port);
1.276 djm 3159: return NULL;
1.73 markus 3160: }
3161:
1.99 markus 3162: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3163: Channel *
3164: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3165: {
1.257 dtucker 3166: int i, permit, permit_adm = 1;
1.99 markus 3167:
3168: permit = all_opens_permitted;
3169: if (!permit) {
3170: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3171: if (permitted_opens[i].host_to_connect != NULL &&
3172: permitted_opens[i].port_to_connect == port &&
1.99 markus 3173: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3174: permit = 1;
1.257 dtucker 3175: }
1.99 markus 3176:
1.257 dtucker 3177: if (num_adm_permitted_opens > 0) {
3178: permit_adm = 0;
3179: for (i = 0; i < num_adm_permitted_opens; i++)
3180: if (permitted_adm_opens[i].host_to_connect != NULL &&
3181: permitted_adm_opens[i].port_to_connect == port &&
3182: strcmp(permitted_adm_opens[i].host_to_connect, host)
3183: == 0)
3184: permit_adm = 1;
1.99 markus 3185: }
1.257 dtucker 3186:
3187: if (!permit || !permit_adm) {
1.188 itojun 3188: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3189: "but the request was denied.", host, port);
1.276 djm 3190: return NULL;
1.99 markus 3191: }
1.276 djm 3192: return connect_to(host, port, ctype, rname);
1.204 djm 3193: }
3194:
3195: void
3196: channel_send_window_changes(void)
3197: {
1.209 avsm 3198: u_int i;
1.204 djm 3199: struct winsize ws;
3200:
3201: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3202: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3203: channels[i]->type != SSH_CHANNEL_OPEN)
3204: continue;
3205: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3206: continue;
3207: channel_request_start(i, "window-change", 0);
1.238 deraadt 3208: packet_put_int((u_int)ws.ws_col);
3209: packet_put_int((u_int)ws.ws_row);
3210: packet_put_int((u_int)ws.ws_xpixel);
3211: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3212: packet_send();
3213: }
1.99 markus 3214: }
3215:
1.121 markus 3216: /* -- X11 forwarding */
1.1 deraadt 3217:
1.27 markus 3218: /*
3219: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3220: * Returns 0 and a suitable display number for the DISPLAY variable
3221: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3222: */
1.141 stevesk 3223: int
1.163 stevesk 3224: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3225: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3226: {
1.149 markus 3227: Channel *nc = NULL;
1.31 markus 3228: int display_number, sock;
3229: u_short port;
1.35 markus 3230: struct addrinfo hints, *ai, *aitop;
3231: char strport[NI_MAXSERV];
3232: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3233:
1.224 markus 3234: if (chanids == NULL)
3235: return -1;
3236:
1.33 markus 3237: for (display_number = x11_display_offset;
1.148 deraadt 3238: display_number < MAX_DISPLAYS;
3239: display_number++) {
1.25 markus 3240: port = 6000 + display_number;
1.35 markus 3241: memset(&hints, 0, sizeof(hints));
3242: hints.ai_family = IPv4or6;
1.163 stevesk 3243: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3244: hints.ai_socktype = SOCK_STREAM;
3245: snprintf(strport, sizeof strport, "%d", port);
3246: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3247: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3248: return -1;
1.25 markus 3249: }
1.35 markus 3250: for (ai = aitop; ai; ai = ai->ai_next) {
3251: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3252: continue;
1.300 dtucker 3253: sock = socket(ai->ai_family, ai->ai_socktype,
3254: ai->ai_protocol);
1.35 markus 3255: if (sock < 0) {
3256: error("socket: %.100s", strerror(errno));
1.203 markus 3257: freeaddrinfo(aitop);
1.141 stevesk 3258: return -1;
1.35 markus 3259: }
1.226 djm 3260: channel_set_reuseaddr(sock);
1.35 markus 3261: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3262: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3263: close(sock);
1.183 itojun 3264:
1.35 markus 3265: for (n = 0; n < num_socks; n++) {
3266: close(socks[n]);
3267: }
3268: num_socks = 0;
3269: break;
3270: }
3271: socks[num_socks++] = sock;
3272: if (num_socks == NUM_SOCKS)
3273: break;
1.25 markus 3274: }
1.83 stevesk 3275: freeaddrinfo(aitop);
1.35 markus 3276: if (num_socks > 0)
3277: break;
1.25 markus 3278: }
3279: if (display_number >= MAX_DISPLAYS) {
3280: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3281: return -1;
1.25 markus 3282: }
3283: /* Start listening for connections on the socket. */
1.35 markus 3284: for (n = 0; n < num_socks; n++) {
3285: sock = socks[n];
1.199 markus 3286: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3287: error("listen: %.100s", strerror(errno));
3288: close(sock);
1.141 stevesk 3289: return -1;
1.35 markus 3290: }
1.25 markus 3291: }
1.35 markus 3292:
3293: /* Allocate a channel for each socket. */
1.242 djm 3294: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3295: for (n = 0; n < num_socks; n++) {
3296: sock = socks[n];
1.149 markus 3297: nc = channel_new("x11 listener",
1.51 markus 3298: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3299: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3300: 0, "X11 inet listener", 1);
1.167 markus 3301: nc->single_connection = single_connection;
1.224 markus 3302: (*chanids)[n] = nc->self;
1.35 markus 3303: }
1.224 markus 3304: (*chanids)[n] = -1;
1.1 deraadt 3305:
1.141 stevesk 3306: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3307: *display_numberp = display_number;
3308: return (0);
1.1 deraadt 3309: }
3310:
1.127 itojun 3311: static int
1.77 markus 3312: connect_local_xsocket(u_int dnr)
1.1 deraadt 3313: {
1.25 markus 3314: int sock;
3315: struct sockaddr_un addr;
3316:
1.147 stevesk 3317: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3318: if (sock < 0)
3319: error("socket: %.100s", strerror(errno));
3320: memset(&addr, 0, sizeof(addr));
3321: addr.sun_family = AF_UNIX;
3322: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3323: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3324: return sock;
3325: close(sock);
1.25 markus 3326: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3327: return -1;
1.1 deraadt 3328: }
3329:
1.51 markus 3330: int
3331: x11_connect_display(void)
1.1 deraadt 3332: {
1.248 deraadt 3333: u_int display_number;
1.25 markus 3334: const char *display;
1.51 markus 3335: char buf[1024], *cp;
1.35 markus 3336: struct addrinfo hints, *ai, *aitop;
3337: char strport[NI_MAXSERV];
1.248 deraadt 3338: int gaierr, sock = 0;
1.25 markus 3339:
3340: /* Try to open a socket for the local X server. */
3341: display = getenv("DISPLAY");
3342: if (!display) {
3343: error("DISPLAY not set.");
1.51 markus 3344: return -1;
1.25 markus 3345: }
1.27 markus 3346: /*
3347: * Now we decode the value of the DISPLAY variable and make a
3348: * connection to the real X server.
3349: */
3350:
3351: /*
3352: * Check if it is a unix domain socket. Unix domain displays are in
3353: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3354: */
1.25 markus 3355: if (strncmp(display, "unix:", 5) == 0 ||
3356: display[0] == ':') {
3357: /* Connect to the unix domain socket. */
1.248 deraadt 3358: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3359: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3360: display);
1.51 markus 3361: return -1;
1.25 markus 3362: }
3363: /* Create a socket. */
3364: sock = connect_local_xsocket(display_number);
3365: if (sock < 0)
1.51 markus 3366: return -1;
1.25 markus 3367:
3368: /* OK, we now have a connection to the display. */
1.51 markus 3369: return sock;
1.25 markus 3370: }
1.27 markus 3371: /*
3372: * Connect to an inet socket. The DISPLAY value is supposedly
3373: * hostname:d[.s], where hostname may also be numeric IP address.
3374: */
1.145 stevesk 3375: strlcpy(buf, display, sizeof(buf));
1.25 markus 3376: cp = strchr(buf, ':');
3377: if (!cp) {
3378: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3379: return -1;
1.25 markus 3380: }
3381: *cp = 0;
1.27 markus 3382: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3383: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 3384: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3385: display);
1.51 markus 3386: return -1;
1.25 markus 3387: }
1.35 markus 3388:
3389: /* Look up the host address */
3390: memset(&hints, 0, sizeof(hints));
3391: hints.ai_family = IPv4or6;
3392: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3393: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3394: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3395: error("%.100s: unknown host. (%s)", buf,
3396: ssh_gai_strerror(gaierr));
1.51 markus 3397: return -1;
1.25 markus 3398: }
1.35 markus 3399: for (ai = aitop; ai; ai = ai->ai_next) {
3400: /* Create a socket. */
1.300 dtucker 3401: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3402: if (sock < 0) {
1.194 markus 3403: debug2("socket: %.100s", strerror(errno));
1.41 markus 3404: continue;
3405: }
3406: /* Connect it to the display. */
3407: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3408: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3409: 6000 + display_number, strerror(errno));
3410: close(sock);
3411: continue;
3412: }
3413: /* Success */
3414: break;
1.35 markus 3415: }
3416: freeaddrinfo(aitop);
3417: if (!ai) {
1.248 deraadt 3418: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3419: strerror(errno));
1.51 markus 3420: return -1;
1.25 markus 3421: }
1.162 stevesk 3422: set_nodelay(sock);
1.51 markus 3423: return sock;
3424: }
3425:
3426: /*
3427: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3428: * the remote channel number. We should do whatever we want, and respond
3429: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3430: */
3431:
1.259 stevesk 3432: /* ARGSUSED */
1.51 markus 3433: void
1.154 markus 3434: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3435: {
1.113 markus 3436: Channel *c = NULL;
3437: int remote_id, sock = 0;
1.51 markus 3438: char *remote_host;
1.25 markus 3439:
1.113 markus 3440: debug("Received X11 open request.");
1.51 markus 3441:
1.113 markus 3442: remote_id = packet_get_int();
1.121 markus 3443:
3444: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3445: remote_host = packet_get_string(NULL);
1.51 markus 3446: } else {
3447: remote_host = xstrdup("unknown (remote did not supply name)");
3448: }
1.152 markus 3449: packet_check_eom();
1.25 markus 3450:
1.51 markus 3451: /* Obtain a connection to the real X display. */
3452: sock = x11_connect_display();
1.113 markus 3453: if (sock != -1) {
3454: /* Allocate a channel for this connection. */
3455: c = channel_new("connected x11 socket",
3456: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3457: remote_host, 1);
1.167 markus 3458: c->remote_id = remote_id;
3459: c->force_drain = 1;
1.113 markus 3460: }
1.190 markus 3461: xfree(remote_host);
1.113 markus 3462: if (c == NULL) {
1.51 markus 3463: /* Send refusal to the remote host. */
3464: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3465: packet_put_int(remote_id);
1.51 markus 3466: } else {
3467: /* Send a confirmation to the remote host. */
3468: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3469: packet_put_int(remote_id);
3470: packet_put_int(c->self);
1.51 markus 3471: }
1.113 markus 3472: packet_send();
1.72 markus 3473: }
3474:
3475: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3476: /* ARGSUSED */
1.72 markus 3477: void
1.154 markus 3478: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3479: {
3480: int rchan = packet_get_int();
1.180 deraadt 3481:
1.143 deraadt 3482: switch (type) {
1.72 markus 3483: case SSH_SMSG_AGENT_OPEN:
3484: error("Warning: ssh server tried agent forwarding.");
3485: break;
3486: case SSH_SMSG_X11_OPEN:
3487: error("Warning: ssh server tried X11 forwarding.");
3488: break;
3489: default:
1.154 markus 3490: error("deny_input_open: type %d", type);
1.72 markus 3491: break;
3492: }
1.230 stevesk 3493: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3494: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3495: packet_put_int(rchan);
3496: packet_send();
1.1 deraadt 3497: }
3498:
1.27 markus 3499: /*
3500: * Requests forwarding of X11 connections, generates fake authentication
3501: * data, and enables authentication spoofing.
1.121 markus 3502: * This should be called in the client only.
1.27 markus 3503: */
1.49 markus 3504: void
1.215 djm 3505: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3506: const char *proto, const char *data)
1.1 deraadt 3507: {
1.77 markus 3508: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3509: u_int i, value;
1.25 markus 3510: char *new_data;
3511: int screen_number;
3512: const char *cp;
1.207 avsm 3513: u_int32_t rnd = 0;
1.25 markus 3514:
1.220 markus 3515: if (x11_saved_display == NULL)
3516: x11_saved_display = xstrdup(disp);
3517: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3518: error("x11_request_forwarding_with_spoofing: different "
3519: "$DISPLAY already forwarded");
3520: return;
3521: }
3522:
1.266 djm 3523: cp = strchr(disp, ':');
1.25 markus 3524: if (cp)
3525: cp = strchr(cp, '.');
3526: if (cp)
1.245 deraadt 3527: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3528: else
3529: screen_number = 0;
3530:
1.219 djm 3531: if (x11_saved_proto == NULL) {
3532: /* Save protocol name. */
3533: x11_saved_proto = xstrdup(proto);
3534: /*
1.221 djm 3535: * Extract real authentication data and generate fake data
1.219 djm 3536: * of the same length.
3537: */
3538: x11_saved_data = xmalloc(data_len);
3539: x11_fake_data = xmalloc(data_len);
3540: for (i = 0; i < data_len; i++) {
3541: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3542: fatal("x11_request_forwarding: bad "
3543: "authentication data: %.100s", data);
3544: if (i % 4 == 0)
3545: rnd = arc4random();
3546: x11_saved_data[i] = value;
3547: x11_fake_data[i] = rnd & 0xff;
3548: rnd >>= 8;
3549: }
3550: x11_saved_data_len = data_len;
3551: x11_fake_data_len = data_len;
1.25 markus 3552: }
3553:
3554: /* Convert the fake data into hex. */
1.219 djm 3555: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3556:
3557: /* Send the request packet. */
1.51 markus 3558: if (compat20) {
3559: channel_request_start(client_session_id, "x11-req", 0);
3560: packet_put_char(0); /* XXX bool single connection */
3561: } else {
3562: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3563: }
3564: packet_put_cstring(proto);
3565: packet_put_cstring(new_data);
1.25 markus 3566: packet_put_int(screen_number);
3567: packet_send();
3568: packet_write_wait();
3569: xfree(new_data);
1.1 deraadt 3570: }
3571:
1.121 markus 3572:
3573: /* -- agent forwarding */
3574:
1.1 deraadt 3575: /* Sends a message to the server to request authentication fd forwarding. */
3576:
1.49 markus 3577: void
1.142 itojun 3578: auth_request_forwarding(void)
1.1 deraadt 3579: {
1.25 markus 3580: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3581: packet_send();
3582: packet_write_wait();
1.1 deraadt 3583: }
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