Annotation of src/usr.bin/ssh/channels.c, Revision 1.304
1.304 ! djm 1: /* $OpenBSD: channels.c,v 1.303 2010/01/30 21:12:08 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. */
1.1 deraadt 113: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
116: static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
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);
1.172 markus 837: else if (!(c->flags & CHAN_EOF_SENT) &&
838: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 839: buffer_len(&c->extended) < c->remote_window)
840: FD_SET(c->efd, readset);
841: }
1.204 djm 842: /* XXX: What about efd? races? */
1.44 markus 843: }
844:
1.259 stevesk 845: /* ARGSUSED */
1.127 itojun 846: static void
1.237 deraadt 847: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 848: {
849: if (buffer_len(&c->input) == 0) {
850: packet_start(SSH_MSG_CHANNEL_CLOSE);
851: packet_put_int(c->remote_id);
852: packet_send();
853: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 854: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 855: }
856: }
857:
1.259 stevesk 858: /* ARGSUSED */
1.127 itojun 859: static void
1.237 deraadt 860: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 861: {
862: if (buffer_len(&c->output) == 0)
1.113 markus 863: chan_mark_dead(c);
1.49 markus 864: else
1.41 markus 865: FD_SET(c->sock, writeset);
866: }
867:
868: /*
869: * This is a special state for X11 authentication spoofing. An opened X11
870: * connection (when authentication spoofing is being done) remains in this
871: * state until the first packet has been completely read. The authentication
872: * data in that packet is then substituted by the real data if it matches the
873: * fake data, and the channel is put into normal mode.
1.51 markus 874: * XXX All this happens at the client side.
1.121 markus 875: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 876: */
1.127 itojun 877: static int
1.121 markus 878: x11_open_helper(Buffer *b)
1.1 deraadt 879: {
1.77 markus 880: u_char *ucp;
881: u_int proto_len, data_len;
1.25 markus 882:
1.41 markus 883: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 884: if (buffer_len(b) < 12)
1.41 markus 885: return 0;
886:
887: /* Parse the lengths of variable-length fields. */
1.155 stevesk 888: ucp = buffer_ptr(b);
1.41 markus 889: if (ucp[0] == 0x42) { /* Byte order MSB first. */
890: proto_len = 256 * ucp[6] + ucp[7];
891: data_len = 256 * ucp[8] + ucp[9];
892: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
893: proto_len = ucp[6] + 256 * ucp[7];
894: data_len = ucp[8] + 256 * ucp[9];
895: } else {
1.194 markus 896: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 897: ucp[0]);
1.41 markus 898: return -1;
899: }
900:
901: /* Check if the whole packet is in buffer. */
1.121 markus 902: if (buffer_len(b) <
1.41 markus 903: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
904: return 0;
905:
906: /* Check if authentication protocol matches. */
907: if (proto_len != strlen(x11_saved_proto) ||
908: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 909: debug2("X11 connection uses different authentication protocol.");
1.41 markus 910: return -1;
911: }
912: /* Check if authentication data matches our fake data. */
913: if (data_len != x11_fake_data_len ||
914: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
915: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 916: debug2("X11 auth data does not match fake data.");
1.41 markus 917: return -1;
918: }
919: /* Check fake data length */
920: if (x11_fake_data_len != x11_saved_data_len) {
921: error("X11 fake_data_len %d != saved_data_len %d",
922: x11_fake_data_len, x11_saved_data_len);
923: return -1;
924: }
925: /*
926: * Received authentication protocol and data match
927: * our fake data. Substitute the fake data with real
928: * data.
929: */
930: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
931: x11_saved_data, x11_saved_data_len);
932: return 1;
933: }
934:
1.127 itojun 935: static void
1.237 deraadt 936: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 937: {
1.121 markus 938: int ret = x11_open_helper(&c->output);
1.180 deraadt 939:
1.41 markus 940: if (ret == 1) {
941: /* Start normal processing for the channel. */
942: c->type = SSH_CHANNEL_OPEN;
1.47 markus 943: channel_pre_open_13(c, readset, writeset);
1.41 markus 944: } else if (ret == -1) {
945: /*
946: * We have received an X11 connection that has bad
947: * authentication information.
948: */
1.188 itojun 949: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 950: buffer_clear(&c->input);
951: buffer_clear(&c->output);
1.132 markus 952: channel_close_fd(&c->sock);
1.41 markus 953: c->sock = -1;
954: c->type = SSH_CHANNEL_CLOSED;
955: packet_start(SSH_MSG_CHANNEL_CLOSE);
956: packet_put_int(c->remote_id);
957: packet_send();
958: }
959: }
1.25 markus 960:
1.127 itojun 961: static void
1.237 deraadt 962: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 963: {
1.121 markus 964: int ret = x11_open_helper(&c->output);
1.133 markus 965:
966: /* c->force_drain = 1; */
967:
1.41 markus 968: if (ret == 1) {
969: c->type = SSH_CHANNEL_OPEN;
1.157 markus 970: channel_pre_open(c, readset, writeset);
1.41 markus 971: } else if (ret == -1) {
1.188 itojun 972: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 973: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 974: chan_read_failed(c);
975: buffer_clear(&c->input);
976: chan_ibuf_empty(c);
977: buffer_clear(&c->output);
978: /* for proto v1, the peer will send an IEOF */
979: if (compat20)
980: chan_write_failed(c);
981: else
982: c->type = SSH_CHANNEL_OPEN;
1.194 markus 983: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 984: }
985: }
1.25 markus 986:
1.302 djm 987: static void
988: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
989: {
1.304 ! djm 990: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 991: buffer_check_alloc(&c->input, CHAN_RBUF))
992: FD_SET(c->rfd, readset);
993: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
994: /* clear buffer immediately (discard any partial packet) */
995: buffer_clear(&c->input);
996: chan_ibuf_empty(c);
997: /* Start output drain. XXX just kill chan? */
998: chan_rcvd_oclose(c);
999: }
1000: if (c->ostate == CHAN_OUTPUT_OPEN ||
1001: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1002: if (buffer_len(&c->output) > 0)
1003: FD_SET(c->wfd, writeset);
1004: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1005: chan_obuf_empty(c);
1006: }
1007: }
1008:
1.104 markus 1009: /* try to decode a socks4 header */
1.259 stevesk 1010: /* ARGSUSED */
1.127 itojun 1011: static int
1.237 deraadt 1012: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1013: {
1.181 markus 1014: char *p, *host;
1.292 djm 1015: u_int len, have, i, found, need;
1.148 deraadt 1016: char username[256];
1.103 markus 1017: struct {
1018: u_int8_t version;
1019: u_int8_t command;
1020: u_int16_t dest_port;
1.104 markus 1021: struct in_addr dest_addr;
1.103 markus 1022: } s4_req, s4_rsp;
1023:
1.104 markus 1024: debug2("channel %d: decode socks4", c->self);
1.109 markus 1025:
1026: have = buffer_len(&c->input);
1027: len = sizeof(s4_req);
1028: if (have < len)
1029: return 0;
1030: p = buffer_ptr(&c->input);
1.292 djm 1031:
1032: need = 1;
1033: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1034: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1035: debug2("channel %d: socks4a request", c->self);
1036: /* ... and needs an extra string (the hostname) */
1037: need = 2;
1038: }
1039: /* Check for terminating NUL on the string(s) */
1.109 markus 1040: for (found = 0, i = len; i < have; i++) {
1041: if (p[i] == '\0') {
1.292 djm 1042: found++;
1043: if (found == need)
1044: break;
1.109 markus 1045: }
1046: if (i > 1024) {
1047: /* the peer is probably sending garbage */
1048: debug("channel %d: decode socks4: too long",
1049: c->self);
1050: return -1;
1051: }
1052: }
1.292 djm 1053: if (found < need)
1.109 markus 1054: return 0;
1.103 markus 1055: buffer_get(&c->input, (char *)&s4_req.version, 1);
1056: buffer_get(&c->input, (char *)&s4_req.command, 1);
1057: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1058: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1059: have = buffer_len(&c->input);
1.103 markus 1060: p = buffer_ptr(&c->input);
1061: len = strlen(p);
1.106 markus 1062: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1063: len++; /* trailing '\0' */
1.103 markus 1064: if (len > have)
1.104 markus 1065: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1066: c->self, len, have);
1067: strlcpy(username, p, sizeof(username));
1068: buffer_consume(&c->input, len);
1069:
1.293 djm 1070: if (c->path != NULL) {
1071: xfree(c->path);
1072: c->path = NULL;
1073: }
1.292 djm 1074: if (need == 1) { /* SOCKS4: one string */
1075: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1076: c->path = xstrdup(host);
1.292 djm 1077: } else { /* SOCKS4A: two strings */
1078: have = buffer_len(&c->input);
1079: p = buffer_ptr(&c->input);
1080: len = strlen(p);
1081: debug2("channel %d: decode socks4a: host %s/%d",
1082: c->self, p, len);
1083: len++; /* trailing '\0' */
1084: if (len > have)
1085: fatal("channel %d: decode socks4a: len %d > have %d",
1086: c->self, len, have);
1.293 djm 1087: if (len > NI_MAXHOST) {
1.292 djm 1088: error("channel %d: hostname \"%.100s\" too long",
1089: c->self, p);
1090: return -1;
1091: }
1.293 djm 1092: c->path = xstrdup(p);
1.292 djm 1093: buffer_consume(&c->input, len);
1094: }
1.103 markus 1095: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1096:
1.194 markus 1097: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1098: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1099:
1.104 markus 1100: if (s4_req.command != 1) {
1.292 djm 1101: debug("channel %d: cannot handle: %s cn %d",
1102: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1103: return -1;
1.103 markus 1104: }
1.104 markus 1105: s4_rsp.version = 0; /* vn: 0 for reply */
1106: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1107: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1108: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1109: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1110: return 1;
1111: }
1112:
1.193 markus 1113: /* try to decode a socks5 header */
1114: #define SSH_SOCKS5_AUTHDONE 0x1000
1115: #define SSH_SOCKS5_NOAUTH 0x00
1116: #define SSH_SOCKS5_IPV4 0x01
1117: #define SSH_SOCKS5_DOMAIN 0x03
1118: #define SSH_SOCKS5_IPV6 0x04
1119: #define SSH_SOCKS5_CONNECT 0x01
1120: #define SSH_SOCKS5_SUCCESS 0x00
1121:
1.259 stevesk 1122: /* ARGSUSED */
1.193 markus 1123: static int
1.237 deraadt 1124: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1125: {
1126: struct {
1127: u_int8_t version;
1128: u_int8_t command;
1129: u_int8_t reserved;
1130: u_int8_t atyp;
1131: } s5_req, s5_rsp;
1132: u_int16_t dest_port;
1.293 djm 1133: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1134: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1135:
1136: debug2("channel %d: decode socks5", c->self);
1137: p = buffer_ptr(&c->input);
1138: if (p[0] != 0x05)
1139: return -1;
1140: have = buffer_len(&c->input);
1141: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1142: /* format: ver | nmethods | methods */
1.198 djm 1143: if (have < 2)
1.193 markus 1144: return 0;
1145: nmethods = p[1];
1146: if (have < nmethods + 2)
1147: return 0;
1148: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1149: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1150: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1151: found = 1;
1152: break;
1153: }
1154: }
1155: if (!found) {
1156: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1157: c->self);
1158: return -1;
1159: }
1160: buffer_consume(&c->input, nmethods + 2);
1161: buffer_put_char(&c->output, 0x05); /* version */
1162: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1163: FD_SET(c->sock, writeset);
1164: c->flags |= SSH_SOCKS5_AUTHDONE;
1165: debug2("channel %d: socks5 auth done", c->self);
1166: return 0; /* need more */
1167: }
1168: debug2("channel %d: socks5 post auth", c->self);
1169: if (have < sizeof(s5_req)+1)
1170: return 0; /* need more */
1.247 deraadt 1171: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1172: if (s5_req.version != 0x05 ||
1173: s5_req.command != SSH_SOCKS5_CONNECT ||
1174: s5_req.reserved != 0x00) {
1.194 markus 1175: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1176: return -1;
1177: }
1.213 deraadt 1178: switch (s5_req.atyp){
1.193 markus 1179: case SSH_SOCKS5_IPV4:
1180: addrlen = 4;
1181: af = AF_INET;
1182: break;
1183: case SSH_SOCKS5_DOMAIN:
1184: addrlen = p[sizeof(s5_req)];
1185: af = -1;
1186: break;
1187: case SSH_SOCKS5_IPV6:
1188: addrlen = 16;
1189: af = AF_INET6;
1190: break;
1191: default:
1.194 markus 1192: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1193: return -1;
1194: }
1.252 djm 1195: need = sizeof(s5_req) + addrlen + 2;
1196: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1197: need++;
1198: if (have < need)
1.193 markus 1199: return 0;
1200: buffer_consume(&c->input, sizeof(s5_req));
1201: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1202: buffer_consume(&c->input, 1); /* host string length */
1203: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1204: buffer_get(&c->input, (char *)&dest_port, 2);
1205: dest_addr[addrlen] = '\0';
1.293 djm 1206: if (c->path != NULL) {
1207: xfree(c->path);
1208: c->path = NULL;
1209: }
1210: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1211: if (addrlen >= NI_MAXHOST) {
1.293 djm 1212: error("channel %d: dynamic request: socks5 hostname "
1213: "\"%.100s\" too long", c->self, dest_addr);
1214: return -1;
1215: }
1216: c->path = xstrdup(dest_addr);
1217: } else {
1218: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1219: return -1;
1220: c->path = xstrdup(ntop);
1221: }
1.193 markus 1222: c->host_port = ntohs(dest_port);
1.198 djm 1223:
1.194 markus 1224: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1225: c->self, c->path, c->host_port, s5_req.command);
1226:
1227: s5_rsp.version = 0x05;
1228: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1229: s5_rsp.reserved = 0; /* ignored */
1230: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1231: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1232: dest_port = 0; /* ignored */
1233:
1.246 deraadt 1234: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1235: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1236: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1237: return 1;
1.301 dtucker 1238: }
1239:
1240: Channel *
1.302 djm 1241: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1242: int in, int out)
1.301 dtucker 1243: {
1244: Channel *c;
1245:
1246: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1247: port_to_connect);
1248:
1249: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1250: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1251: 0, "stdio-forward", /*nonblock*/0);
1252:
1253: c->path = xstrdup(host_to_connect);
1254: c->host_port = port_to_connect;
1255: c->listening_port = 0;
1256: c->force_drain = 1;
1257:
1258: channel_register_fds(c, in, out, -1, 0, 1, 0);
1259: port_open_helper(c, "direct-tcpip");
1260:
1261: return c;
1.193 markus 1262: }
1263:
1.104 markus 1264: /* dynamic port forwarding */
1.127 itojun 1265: static void
1.237 deraadt 1266: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1267: {
1268: u_char *p;
1.217 djm 1269: u_int have;
1270: int ret;
1.103 markus 1271:
1.104 markus 1272: have = buffer_len(&c->input);
1273: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1274: /* buffer_dump(&c->input); */
1.104 markus 1275: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1276: if (have < 3) {
1.104 markus 1277: /* need more */
1278: FD_SET(c->sock, readset);
1279: return;
1280: }
1281: /* try to guess the protocol */
1282: p = buffer_ptr(&c->input);
1283: switch (p[0]) {
1284: case 0x04:
1285: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1286: break;
1287: case 0x05:
1288: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1289: break;
1290: default:
1291: ret = -1;
1292: break;
1293: }
1294: if (ret < 0) {
1.113 markus 1295: chan_mark_dead(c);
1.104 markus 1296: } else if (ret == 0) {
1297: debug2("channel %d: pre_dynamic: need more", c->self);
1298: /* need more */
1299: FD_SET(c->sock, readset);
1300: } else {
1301: /* switch to the next state */
1302: c->type = SSH_CHANNEL_OPENING;
1303: port_open_helper(c, "direct-tcpip");
1304: }
1.103 markus 1305: }
1306:
1.41 markus 1307: /* This is our fake X11 server socket. */
1.259 stevesk 1308: /* ARGSUSED */
1.127 itojun 1309: static void
1.237 deraadt 1310: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1311: {
1.113 markus 1312: Channel *nc;
1.285 djm 1313: struct sockaddr_storage addr;
1.162 stevesk 1314: int newsock;
1.41 markus 1315: socklen_t addrlen;
1.85 markus 1316: char buf[16384], *remote_ipaddr;
1.51 markus 1317: int remote_port;
1.25 markus 1318:
1.41 markus 1319: if (FD_ISSET(c->sock, readset)) {
1320: debug("X11 connection requested.");
1321: addrlen = sizeof(addr);
1.285 djm 1322: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1323: if (c->single_connection) {
1.194 markus 1324: debug2("single_connection: closing X11 listener.");
1.149 markus 1325: channel_close_fd(&c->sock);
1326: chan_mark_dead(c);
1327: }
1.41 markus 1328: if (newsock < 0) {
1329: error("accept: %.100s", strerror(errno));
1330: return;
1331: }
1.162 stevesk 1332: set_nodelay(newsock);
1.85 markus 1333: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1334: remote_port = get_peer_port(newsock);
1.41 markus 1335: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1336: remote_ipaddr, remote_port);
1.51 markus 1337:
1.113 markus 1338: nc = channel_new("accepted x11 socket",
1.51 markus 1339: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1340: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1341: if (compat20) {
1342: packet_start(SSH2_MSG_CHANNEL_OPEN);
1343: packet_put_cstring("x11");
1.113 markus 1344: packet_put_int(nc->self);
1.149 markus 1345: packet_put_int(nc->local_window_max);
1346: packet_put_int(nc->local_maxpacket);
1.85 markus 1347: /* originator ipaddr and port */
1348: packet_put_cstring(remote_ipaddr);
1.57 markus 1349: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1350: debug2("ssh2 x11 bug compat mode");
1.57 markus 1351: } else {
1352: packet_put_int(remote_port);
1353: }
1.51 markus 1354: packet_send();
1355: } else {
1356: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1357: packet_put_int(nc->self);
1.121 markus 1358: if (packet_get_protocol_flags() &
1359: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1360: packet_put_cstring(buf);
1.51 markus 1361: packet_send();
1362: }
1.85 markus 1363: xfree(remote_ipaddr);
1.41 markus 1364: }
1365: }
1.25 markus 1366:
1.127 itojun 1367: static void
1.103 markus 1368: port_open_helper(Channel *c, char *rtype)
1369: {
1370: int direct;
1371: char buf[1024];
1372: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1373: int remote_port = get_peer_port(c->sock);
1.303 djm 1374:
1375: if (remote_port == -1) {
1376: /* Fake addr/port to appease peers that validate it (Tectia) */
1377: xfree(remote_ipaddr);
1378: remote_ipaddr = xstrdup("127.0.0.1");
1379: remote_port = 65535;
1380: }
1.103 markus 1381:
1382: direct = (strcmp(rtype, "direct-tcpip") == 0);
1383:
1384: snprintf(buf, sizeof buf,
1385: "%s: listening port %d for %.100s port %d, "
1386: "connect from %.200s port %d",
1387: rtype, c->listening_port, c->path, c->host_port,
1388: remote_ipaddr, remote_port);
1389:
1390: xfree(c->remote_name);
1391: c->remote_name = xstrdup(buf);
1392:
1393: if (compat20) {
1394: packet_start(SSH2_MSG_CHANNEL_OPEN);
1395: packet_put_cstring(rtype);
1396: packet_put_int(c->self);
1397: packet_put_int(c->local_window_max);
1398: packet_put_int(c->local_maxpacket);
1399: if (direct) {
1400: /* target host, port */
1401: packet_put_cstring(c->path);
1402: packet_put_int(c->host_port);
1403: } else {
1404: /* listen address, port */
1405: packet_put_cstring(c->path);
1406: packet_put_int(c->listening_port);
1407: }
1408: /* originator host and port */
1409: packet_put_cstring(remote_ipaddr);
1.216 markus 1410: packet_put_int((u_int)remote_port);
1.103 markus 1411: packet_send();
1412: } else {
1413: packet_start(SSH_MSG_PORT_OPEN);
1414: packet_put_int(c->self);
1415: packet_put_cstring(c->path);
1416: packet_put_int(c->host_port);
1.121 markus 1417: if (packet_get_protocol_flags() &
1418: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1419: packet_put_cstring(c->remote_name);
1420: packet_send();
1421: }
1422: xfree(remote_ipaddr);
1423: }
1424:
1.226 djm 1425: static void
1426: channel_set_reuseaddr(int fd)
1427: {
1428: int on = 1;
1429:
1430: /*
1431: * Set socket options.
1432: * Allow local port reuse in TIME_WAIT.
1433: */
1434: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1435: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1436: }
1437:
1.41 markus 1438: /*
1439: * This socket is listening for connections to a forwarded TCP/IP port.
1440: */
1.259 stevesk 1441: /* ARGSUSED */
1.127 itojun 1442: static void
1.237 deraadt 1443: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1444: {
1.103 markus 1445: Channel *nc;
1.285 djm 1446: struct sockaddr_storage addr;
1.113 markus 1447: int newsock, nextstate;
1.41 markus 1448: socklen_t addrlen;
1.103 markus 1449: char *rtype;
1.73 markus 1450:
1.41 markus 1451: if (FD_ISSET(c->sock, readset)) {
1452: debug("Connection to port %d forwarding "
1453: "to %.100s port %d requested.",
1454: c->listening_port, c->path, c->host_port);
1.103 markus 1455:
1.137 markus 1456: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1457: nextstate = SSH_CHANNEL_OPENING;
1458: rtype = "forwarded-tcpip";
1459: } else {
1460: if (c->host_port == 0) {
1461: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1462: rtype = "dynamic-tcpip";
1.137 markus 1463: } else {
1464: nextstate = SSH_CHANNEL_OPENING;
1465: rtype = "direct-tcpip";
1466: }
1467: }
1.103 markus 1468:
1.41 markus 1469: addrlen = sizeof(addr);
1.285 djm 1470: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1471: if (newsock < 0) {
1472: error("accept: %.100s", strerror(errno));
1473: return;
1474: }
1.169 stevesk 1475: set_nodelay(newsock);
1.190 markus 1476: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1477: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1478: nc->listening_port = c->listening_port;
1479: nc->host_port = c->host_port;
1.293 djm 1480: if (c->path != NULL)
1481: nc->path = xstrdup(c->path);
1.103 markus 1482:
1.299 markus 1483: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1484: port_open_helper(nc, rtype);
1.41 markus 1485: }
1486: }
1.25 markus 1487:
1.41 markus 1488: /*
1489: * This is the authentication agent socket listening for connections from
1490: * clients.
1491: */
1.259 stevesk 1492: /* ARGSUSED */
1.127 itojun 1493: static void
1.237 deraadt 1494: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1495: {
1.113 markus 1496: Channel *nc;
1497: int newsock;
1.285 djm 1498: struct sockaddr_storage addr;
1.41 markus 1499: socklen_t addrlen;
1.25 markus 1500:
1.41 markus 1501: if (FD_ISSET(c->sock, readset)) {
1502: addrlen = sizeof(addr);
1.285 djm 1503: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1504: if (newsock < 0) {
1505: error("accept from auth socket: %.100s", strerror(errno));
1506: return;
1507: }
1.113 markus 1508: nc = channel_new("accepted auth socket",
1.73 markus 1509: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1510: c->local_window_max, c->local_maxpacket,
1.190 markus 1511: 0, "accepted auth socket", 1);
1.73 markus 1512: if (compat20) {
1513: packet_start(SSH2_MSG_CHANNEL_OPEN);
1514: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1515: packet_put_int(nc->self);
1.73 markus 1516: packet_put_int(c->local_window_max);
1517: packet_put_int(c->local_maxpacket);
1518: } else {
1519: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1520: packet_put_int(nc->self);
1.73 markus 1521: }
1.41 markus 1522: packet_send();
1523: }
1524: }
1.25 markus 1525:
1.259 stevesk 1526: /* ARGSUSED */
1.127 itojun 1527: static void
1.237 deraadt 1528: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1529: {
1.276 djm 1530: int err = 0, sock;
1.129 stevesk 1531: socklen_t sz = sizeof(err);
1.114 markus 1532:
1.75 markus 1533: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1534: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1535: err = errno;
1536: error("getsockopt SO_ERROR failed");
1537: }
1538: if (err == 0) {
1.276 djm 1539: debug("channel %d: connected to %s port %d",
1540: c->self, c->connect_ctx.host, c->connect_ctx.port);
1541: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1542: c->type = SSH_CHANNEL_OPEN;
1543: if (compat20) {
1544: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1545: packet_put_int(c->remote_id);
1546: packet_put_int(c->self);
1547: packet_put_int(c->local_window);
1548: packet_put_int(c->local_maxpacket);
1549: } else {
1550: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1551: packet_put_int(c->remote_id);
1552: packet_put_int(c->self);
1553: }
1.75 markus 1554: } else {
1.276 djm 1555: debug("channel %d: connection failed: %s",
1.114 markus 1556: c->self, strerror(err));
1.276 djm 1557: /* Try next address, if any */
1558: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1559: close(c->sock);
1560: c->sock = c->rfd = c->wfd = sock;
1561: channel_max_fd = channel_find_maxfd();
1562: return;
1563: }
1564: /* Exhausted all addresses */
1565: error("connect_to %.100s port %d: failed.",
1566: c->connect_ctx.host, c->connect_ctx.port);
1567: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1568: if (compat20) {
1569: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1570: packet_put_int(c->remote_id);
1571: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1572: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1573: packet_put_cstring(strerror(err));
1574: packet_put_cstring("");
1575: }
1.75 markus 1576: } else {
1.114 markus 1577: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1578: packet_put_int(c->remote_id);
1.75 markus 1579: }
1.114 markus 1580: chan_mark_dead(c);
1.75 markus 1581: }
1.114 markus 1582: packet_send();
1.75 markus 1583: }
1584: }
1585:
1.259 stevesk 1586: /* ARGSUSED */
1.127 itojun 1587: static int
1.237 deraadt 1588: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1589: {
1.214 markus 1590: char buf[CHAN_RBUF];
1.41 markus 1591: int len;
1.25 markus 1592:
1.118 markus 1593: if (c->rfd != -1 &&
1.41 markus 1594: FD_ISSET(c->rfd, readset)) {
1595: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1596: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1597: return 1;
1.41 markus 1598: if (len <= 0) {
1.194 markus 1599: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1600: c->self, c->rfd, len);
1.104 markus 1601: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1602: debug2("channel %d: not open", c->self);
1.113 markus 1603: chan_mark_dead(c);
1.103 markus 1604: return -1;
1.104 markus 1605: } else if (compat13) {
1.158 markus 1606: buffer_clear(&c->output);
1.41 markus 1607: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1608: debug2("channel %d: input draining.", c->self);
1.25 markus 1609: } else {
1.41 markus 1610: chan_read_failed(c);
1.25 markus 1611: }
1.41 markus 1612: return -1;
1613: }
1.143 deraadt 1614: if (c->input_filter != NULL) {
1.66 markus 1615: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1616: debug2("channel %d: filter stops", c->self);
1.65 markus 1617: chan_read_failed(c);
1618: }
1.228 reyk 1619: } else if (c->datagram) {
1620: buffer_put_string(&c->input, buf, len);
1.65 markus 1621: } else {
1622: buffer_append(&c->input, buf, len);
1623: }
1.41 markus 1624: }
1625: return 1;
1626: }
1.241 deraadt 1627:
1.259 stevesk 1628: /* ARGSUSED */
1.127 itojun 1629: static int
1.237 deraadt 1630: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1631: {
1.95 markus 1632: struct termios tio;
1.231 reyk 1633: u_char *data = NULL, *buf;
1.134 markus 1634: u_int dlen;
1.41 markus 1635: int len;
1.25 markus 1636:
1.41 markus 1637: /* Send buffered output data to the socket. */
1.118 markus 1638: if (c->wfd != -1 &&
1.41 markus 1639: FD_ISSET(c->wfd, writeset) &&
1640: buffer_len(&c->output) > 0) {
1.231 reyk 1641: if (c->output_filter != NULL) {
1642: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1643: debug2("channel %d: filter stops", c->self);
1.232 reyk 1644: if (c->type != SSH_CHANNEL_OPEN)
1645: chan_mark_dead(c);
1646: else
1647: chan_write_failed(c);
1648: return -1;
1.231 reyk 1649: }
1650: } else if (c->datagram) {
1651: buf = data = buffer_get_string(&c->output, &dlen);
1652: } else {
1653: buf = data = buffer_ptr(&c->output);
1654: dlen = buffer_len(&c->output);
1655: }
1656:
1.228 reyk 1657: if (c->datagram) {
1658: /* ignore truncated writes, datagrams might get lost */
1659: c->local_consumed += dlen + 4;
1.231 reyk 1660: len = write(c->wfd, buf, dlen);
1.228 reyk 1661: xfree(data);
1662: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1663: return 1;
1664: if (len <= 0) {
1665: if (c->type != SSH_CHANNEL_OPEN)
1666: chan_mark_dead(c);
1667: else
1668: chan_write_failed(c);
1669: return -1;
1670: }
1671: return 1;
1672: }
1.231 reyk 1673:
1674: len = write(c->wfd, buf, dlen);
1.53 markus 1675: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1676: return 1;
1.41 markus 1677: if (len <= 0) {
1.104 markus 1678: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1679: debug2("channel %d: not open", c->self);
1.113 markus 1680: chan_mark_dead(c);
1.104 markus 1681: return -1;
1682: } else if (compat13) {
1.158 markus 1683: buffer_clear(&c->output);
1.194 markus 1684: debug2("channel %d: input draining.", c->self);
1.41 markus 1685: c->type = SSH_CHANNEL_INPUT_DRAINING;
1686: } else {
1687: chan_write_failed(c);
1688: }
1689: return -1;
1.91 markus 1690: }
1.231 reyk 1691: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1692: if (tcgetattr(c->wfd, &tio) == 0 &&
1693: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1694: /*
1695: * Simulate echo to reduce the impact of
1.96 markus 1696: * traffic analysis. We need to match the
1.95 markus 1697: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1698: * (4 byte channel id + buf)
1.91 markus 1699: */
1.95 markus 1700: packet_send_ignore(4 + len);
1.91 markus 1701: packet_send();
1702: }
1.25 markus 1703: }
1.41 markus 1704: buffer_consume(&c->output, len);
1.44 markus 1705: if (compat20 && len > 0) {
1706: c->local_consumed += len;
1707: }
1708: }
1709: return 1;
1710: }
1.241 deraadt 1711:
1.127 itojun 1712: static int
1.237 deraadt 1713: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1714: {
1.214 markus 1715: char buf[CHAN_RBUF];
1.44 markus 1716: int len;
1717:
1.45 markus 1718: /** XXX handle drain efd, too */
1.44 markus 1719: if (c->efd != -1) {
1720: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1721: FD_ISSET(c->efd, writeset) &&
1722: buffer_len(&c->extended) > 0) {
1723: len = write(c->efd, buffer_ptr(&c->extended),
1724: buffer_len(&c->extended));
1.70 markus 1725: debug2("channel %d: written %d to efd %d",
1.44 markus 1726: c->self, len, c->efd);
1.93 markus 1727: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1728: return 1;
1729: if (len <= 0) {
1730: debug2("channel %d: closing write-efd %d",
1731: c->self, c->efd);
1.132 markus 1732: channel_close_fd(&c->efd);
1.93 markus 1733: } else {
1.44 markus 1734: buffer_consume(&c->extended, len);
1735: c->local_consumed += len;
1736: }
1737: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1738: FD_ISSET(c->efd, readset)) {
1739: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1740: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1741: c->self, len, c->efd);
1.93 markus 1742: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1743: return 1;
1744: if (len <= 0) {
1745: debug2("channel %d: closing read-efd %d",
1.45 markus 1746: c->self, c->efd);
1.132 markus 1747: channel_close_fd(&c->efd);
1.93 markus 1748: } else {
1.44 markus 1749: buffer_append(&c->extended, buf, len);
1.93 markus 1750: }
1.44 markus 1751: }
1752: }
1753: return 1;
1754: }
1.241 deraadt 1755:
1.259 stevesk 1756: /* ARGSUSED */
1.127 itojun 1757: static int
1.93 markus 1758: channel_check_window(Channel *c)
1.44 markus 1759: {
1.104 markus 1760: if (c->type == SSH_CHANNEL_OPEN &&
1761: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1762: ((c->local_window_max - c->local_window >
1.269 markus 1763: c->local_maxpacket*3) ||
1764: c->local_window < c->local_window_max/2) &&
1.44 markus 1765: c->local_consumed > 0) {
1766: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1767: packet_put_int(c->remote_id);
1768: packet_put_int(c->local_consumed);
1769: packet_send();
1.70 markus 1770: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1771: c->self, c->local_window,
1772: c->local_consumed);
1773: c->local_window += c->local_consumed;
1774: c->local_consumed = 0;
1.1 deraadt 1775: }
1.41 markus 1776: return 1;
1.1 deraadt 1777: }
1778:
1.127 itojun 1779: static void
1.237 deraadt 1780: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1781: {
1782: channel_handle_rfd(c, readset, writeset);
1783: channel_handle_wfd(c, readset, writeset);
1.157 markus 1784: if (!compat20)
1.137 markus 1785: return;
1.44 markus 1786: channel_handle_efd(c, readset, writeset);
1.93 markus 1787: channel_check_window(c);
1.44 markus 1788: }
1789:
1.302 djm 1790: static u_int
1791: read_mux(Channel *c, u_int need)
1792: {
1793: char buf[CHAN_RBUF];
1794: int len;
1795: u_int rlen;
1796:
1797: if (buffer_len(&c->input) < need) {
1798: rlen = need - buffer_len(&c->input);
1799: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1800: if (len <= 0) {
1801: if (errno != EINTR && errno != EAGAIN) {
1802: debug2("channel %d: ctl read<=0 rfd %d len %d",
1803: c->self, c->rfd, len);
1804: chan_read_failed(c);
1805: return 0;
1806: }
1807: } else
1808: buffer_append(&c->input, buf, len);
1809: }
1810: return buffer_len(&c->input);
1811: }
1812:
1813: static void
1814: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1815: {
1816: u_int need;
1817: ssize_t len;
1818:
1819: if (!compat20)
1820: fatal("%s: entered with !compat20", __func__);
1821:
1.304 ! djm 1822: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1823: (c->istate == CHAN_INPUT_OPEN ||
1824: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1825: /*
1826: * Don't not read past the precise end of packets to
1827: * avoid disrupting fd passing.
1828: */
1829: if (read_mux(c, 4) < 4) /* read header */
1830: return;
1831: need = get_u32(buffer_ptr(&c->input));
1832: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1833: if (need > CHANNEL_MUX_MAX_PACKET) {
1834: debug2("channel %d: packet too big %u > %u",
1835: c->self, CHANNEL_MUX_MAX_PACKET, need);
1836: chan_rcvd_oclose(c);
1837: return;
1838: }
1839: if (read_mux(c, need + 4) < need + 4) /* read body */
1840: return;
1841: if (c->mux_rcb(c) != 0) {
1842: debug("channel %d: mux_rcb failed", c->self);
1843: chan_mark_dead(c);
1844: return;
1845: }
1846: }
1847:
1848: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1849: buffer_len(&c->output) > 0) {
1850: len = write(c->wfd, buffer_ptr(&c->output),
1851: buffer_len(&c->output));
1852: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1853: return;
1854: if (len <= 0) {
1855: chan_mark_dead(c);
1856: return;
1857: }
1858: buffer_consume(&c->output, len);
1859: }
1860: }
1861:
1862: static void
1863: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1864: {
1865: Channel *nc;
1866: struct sockaddr_storage addr;
1867: socklen_t addrlen;
1868: int newsock;
1869: uid_t euid;
1870: gid_t egid;
1871:
1872: if (!FD_ISSET(c->sock, readset))
1873: return;
1874:
1875: debug("multiplexing control connection");
1876:
1877: /*
1878: * Accept connection on control socket
1879: */
1880: memset(&addr, 0, sizeof(addr));
1881: addrlen = sizeof(addr);
1882: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1883: &addrlen)) == -1) {
1884: error("%s accept: %s", __func__, strerror(errno));
1885: return;
1886: }
1887:
1888: if (getpeereid(newsock, &euid, &egid) < 0) {
1889: error("%s getpeereid failed: %s", __func__,
1890: strerror(errno));
1891: close(newsock);
1892: return;
1893: }
1894: if ((euid != 0) && (getuid() != euid)) {
1895: error("multiplex uid mismatch: peer euid %u != uid %u",
1896: (u_int)euid, (u_int)getuid());
1897: close(newsock);
1898: return;
1899: }
1900: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1901: newsock, newsock, -1, c->local_window_max,
1902: c->local_maxpacket, 0, "mux-control", 1);
1903: nc->mux_rcb = c->mux_rcb;
1904: debug3("%s: new mux channel %d fd %d", __func__,
1905: nc->self, nc->sock);
1906: /* establish state */
1907: nc->mux_rcb(nc);
1908: /* mux state transitions must not elicit protocol messages */
1909: nc->flags |= CHAN_LOCAL;
1910: }
1911:
1.259 stevesk 1912: /* ARGSUSED */
1.127 itojun 1913: static void
1.237 deraadt 1914: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1915: {
1.41 markus 1916: int len;
1.180 deraadt 1917:
1.41 markus 1918: /* Send buffered output data to the socket. */
1919: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1920: len = write(c->sock, buffer_ptr(&c->output),
1921: buffer_len(&c->output));
1922: if (len <= 0)
1.158 markus 1923: buffer_clear(&c->output);
1.41 markus 1924: else
1925: buffer_consume(&c->output, len);
1926: }
1927: }
1.25 markus 1928:
1.127 itojun 1929: static void
1.44 markus 1930: channel_handler_init_20(void)
1931: {
1.157 markus 1932: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1933: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1934: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1935: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1936: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1937: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1938: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1939: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 1940: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1941: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1942:
1.157 markus 1943: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1944: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1945: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1946: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1947: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1948: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1949: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 1950: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1951: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1952: }
1953:
1.127 itojun 1954: static void
1.41 markus 1955: channel_handler_init_13(void)
1956: {
1957: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1958: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1959: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1960: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1961: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1962: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1963: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1964: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1965: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1966:
1.157 markus 1967: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1968: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1969: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1970: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1971: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1972: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1973: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1974: }
1.25 markus 1975:
1.127 itojun 1976: static void
1.41 markus 1977: channel_handler_init_15(void)
1978: {
1.157 markus 1979: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1980: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1981: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1982: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1983: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1984: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1985: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1986:
1.41 markus 1987: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1988: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1989: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1990: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1991: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1992: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1993: }
1.27 markus 1994:
1.127 itojun 1995: static void
1.41 markus 1996: channel_handler_init(void)
1997: {
1998: int i;
1.180 deraadt 1999:
1.148 deraadt 2000: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2001: channel_pre[i] = NULL;
2002: channel_post[i] = NULL;
2003: }
1.44 markus 2004: if (compat20)
2005: channel_handler_init_20();
2006: else if (compat13)
1.41 markus 2007: channel_handler_init_13();
2008: else
2009: channel_handler_init_15();
2010: }
1.25 markus 2011:
1.140 markus 2012: /* gc dead channels */
2013: static void
2014: channel_garbage_collect(Channel *c)
2015: {
2016: if (c == NULL)
2017: return;
2018: if (c->detach_user != NULL) {
1.225 djm 2019: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2020: return;
1.194 markus 2021: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2022: c->detach_user(c->self, NULL);
2023: /* if we still have a callback */
2024: if (c->detach_user != NULL)
2025: return;
1.194 markus 2026: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2027: }
2028: if (!chan_is_dead(c, 1))
2029: return;
1.194 markus 2030: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2031: channel_free(c);
2032: }
2033:
1.127 itojun 2034: static void
1.237 deraadt 2035: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 2036: {
2037: static int did_init = 0;
1.299 markus 2038: u_int i, oalloc;
1.41 markus 2039: Channel *c;
1.25 markus 2040:
1.41 markus 2041: if (!did_init) {
2042: channel_handler_init();
2043: did_init = 1;
2044: }
1.299 markus 2045: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2046: c = channels[i];
2047: if (c == NULL)
1.41 markus 2048: continue;
1.299 markus 2049: if (c->delayed) {
2050: if (ftab == channel_pre)
2051: c->delayed = 0;
2052: else
2053: continue;
2054: }
1.118 markus 2055: if (ftab[c->type] != NULL)
2056: (*ftab[c->type])(c, readset, writeset);
1.140 markus 2057: channel_garbage_collect(c);
1.1 deraadt 2058: }
2059: }
2060:
1.121 markus 2061: /*
2062: * Allocate/update select bitmasks and add any bits relevant to channels in
2063: * select bitmasks.
2064: */
1.49 markus 2065: void
1.100 markus 2066: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 2067: u_int *nallocp, int rekeying)
1.41 markus 2068: {
1.243 djm 2069: u_int n, sz, nfdset;
1.84 markus 2070:
2071: n = MAX(*maxfdp, channel_max_fd);
2072:
1.243 djm 2073: nfdset = howmany(n+1, NFDBITS);
2074: /* Explicitly test here, because xrealloc isn't always called */
2075: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2076: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2077: sz = nfdset * sizeof(fd_mask);
2078:
1.132 markus 2079: /* perhaps check sz < nalloc/2 and shrink? */
2080: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2081: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2082: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2083: *nallocp = sz;
1.84 markus 2084: }
1.132 markus 2085: *maxfdp = n;
1.84 markus 2086: memset(*readsetp, 0, sz);
2087: memset(*writesetp, 0, sz);
2088:
1.100 markus 2089: if (!rekeying)
2090: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 2091: }
2092:
1.121 markus 2093: /*
2094: * After select, perform any appropriate operations for channels which have
2095: * events pending.
2096: */
1.49 markus 2097: void
1.237 deraadt 2098: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2099: {
2100: channel_handler(channel_post, readset, writeset);
2101: }
2102:
1.121 markus 2103:
1.84 markus 2104: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2105: void
1.142 itojun 2106: channel_output_poll(void)
1.1 deraadt 2107: {
1.41 markus 2108: Channel *c;
1.209 avsm 2109: u_int i, len;
1.1 deraadt 2110:
1.25 markus 2111: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2112: c = channels[i];
2113: if (c == NULL)
2114: continue;
1.37 markus 2115:
1.121 markus 2116: /*
2117: * We are only interested in channels that can have buffered
2118: * incoming data.
2119: */
1.37 markus 2120: if (compat13) {
1.41 markus 2121: if (c->type != SSH_CHANNEL_OPEN &&
2122: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2123: continue;
2124: } else {
1.41 markus 2125: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2126: continue;
2127: }
1.46 markus 2128: if (compat20 &&
2129: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2130: /* XXX is this true? */
1.140 markus 2131: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2132: continue;
2133: }
1.25 markus 2134:
2135: /* Get the amount of buffered data for this channel. */
1.93 markus 2136: if ((c->istate == CHAN_INPUT_OPEN ||
2137: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2138: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2139: if (c->datagram) {
2140: if (len > 0) {
2141: u_char *data;
2142: u_int dlen;
2143:
2144: data = buffer_get_string(&c->input,
2145: &dlen);
2146: packet_start(SSH2_MSG_CHANNEL_DATA);
2147: packet_put_int(c->remote_id);
2148: packet_put_string(data, dlen);
2149: packet_send();
2150: c->remote_window -= dlen + 4;
2151: xfree(data);
2152: }
2153: continue;
2154: }
1.121 markus 2155: /*
2156: * Send some data for the other side over the secure
2157: * connection.
2158: */
1.44 markus 2159: if (compat20) {
2160: if (len > c->remote_window)
2161: len = c->remote_window;
2162: if (len > c->remote_maxpacket)
2163: len = c->remote_maxpacket;
1.25 markus 2164: } else {
1.44 markus 2165: if (packet_is_interactive()) {
2166: if (len > 1024)
2167: len = 512;
2168: } else {
2169: /* Keep the packets at reasonable size. */
2170: if (len > packet_get_maxsize()/2)
2171: len = packet_get_maxsize()/2;
2172: }
1.25 markus 2173: }
1.41 markus 2174: if (len > 0) {
1.44 markus 2175: packet_start(compat20 ?
2176: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2177: packet_put_int(c->remote_id);
2178: packet_put_string(buffer_ptr(&c->input), len);
2179: packet_send();
2180: buffer_consume(&c->input, len);
2181: c->remote_window -= len;
2182: }
2183: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2184: if (compat13)
2185: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2186: /*
2187: * input-buffer is empty and read-socket shutdown:
1.172 markus 2188: * tell peer, that we will not send more data: send IEOF.
2189: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2190: */
1.172 markus 2191: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2192: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2193: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2194: else
2195: chan_ibuf_empty(c);
1.25 markus 2196: }
1.44 markus 2197: /* Send extended data, i.e. stderr */
2198: if (compat20 &&
1.172 markus 2199: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2200: c->remote_window > 0 &&
2201: (len = buffer_len(&c->extended)) > 0 &&
2202: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2203: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2204: c->self, c->remote_window, buffer_len(&c->extended),
2205: c->extended_usage);
1.44 markus 2206: if (len > c->remote_window)
2207: len = c->remote_window;
2208: if (len > c->remote_maxpacket)
2209: len = c->remote_maxpacket;
2210: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2211: packet_put_int(c->remote_id);
2212: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2213: packet_put_string(buffer_ptr(&c->extended), len);
2214: packet_send();
2215: buffer_consume(&c->extended, len);
2216: c->remote_window -= len;
1.93 markus 2217: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2218: }
1.25 markus 2219: }
1.1 deraadt 2220: }
2221:
1.121 markus 2222:
2223: /* -- protocol input */
1.249 djm 2224:
2225: /* ARGSUSED */
1.49 markus 2226: void
1.154 markus 2227: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2228: {
1.37 markus 2229: int id;
1.25 markus 2230: char *data;
1.77 markus 2231: u_int data_len;
1.41 markus 2232: Channel *c;
1.25 markus 2233:
2234: /* Get the channel number and verify it. */
1.37 markus 2235: id = packet_get_int();
1.41 markus 2236: c = channel_lookup(id);
2237: if (c == NULL)
1.37 markus 2238: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2239:
2240: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2241: if (c->type != SSH_CHANNEL_OPEN &&
2242: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2243: return;
2244:
1.25 markus 2245: /* Get the data. */
1.274 markus 2246: data = packet_get_string_ptr(&data_len);
1.200 markus 2247:
2248: /*
2249: * Ignore data for protocol > 1.3 if output end is no longer open.
2250: * For protocol 2 the sending side is reducing its window as it sends
2251: * data, so we must 'fake' consumption of the data in order to ensure
2252: * that window updates are sent back. Otherwise the connection might
2253: * deadlock.
2254: */
2255: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2256: if (compat20) {
2257: c->local_window -= data_len;
2258: c->local_consumed += data_len;
2259: }
2260: return;
2261: }
1.41 markus 2262:
1.143 deraadt 2263: if (compat20) {
1.44 markus 2264: if (data_len > c->local_maxpacket) {
1.188 itojun 2265: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 2266: c->self, data_len, c->local_maxpacket);
2267: }
2268: if (data_len > c->local_window) {
1.188 itojun 2269: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 2270: c->self, data_len, c->local_window);
2271: return;
2272: }
2273: c->local_window -= data_len;
2274: }
1.228 reyk 2275: if (c->datagram)
2276: buffer_put_string(&c->output, data, data_len);
2277: else
2278: buffer_append(&c->output, data, data_len);
1.274 markus 2279: packet_check_eom();
1.1 deraadt 2280: }
1.121 markus 2281:
1.249 djm 2282: /* ARGSUSED */
1.49 markus 2283: void
1.154 markus 2284: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2285: {
2286: int id;
2287: char *data;
1.177 markus 2288: u_int data_len, tcode;
1.44 markus 2289: Channel *c;
2290:
2291: /* Get the channel number and verify it. */
2292: id = packet_get_int();
2293: c = channel_lookup(id);
2294:
2295: if (c == NULL)
2296: packet_disconnect("Received extended_data for bad channel %d.", id);
2297: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2298: logit("channel %d: ext data for non open", id);
1.44 markus 2299: return;
1.172 markus 2300: }
2301: if (c->flags & CHAN_EOF_RCVD) {
2302: if (datafellows & SSH_BUG_EXTEOF)
2303: debug("channel %d: accepting ext data after eof", id);
2304: else
2305: packet_disconnect("Received extended_data after EOF "
2306: "on channel %d.", id);
1.44 markus 2307: }
2308: tcode = packet_get_int();
2309: if (c->efd == -1 ||
2310: c->extended_usage != CHAN_EXTENDED_WRITE ||
2311: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2312: logit("channel %d: bad ext data", c->self);
1.44 markus 2313: return;
2314: }
2315: data = packet_get_string(&data_len);
1.152 markus 2316: packet_check_eom();
1.44 markus 2317: if (data_len > c->local_window) {
1.188 itojun 2318: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2319: c->self, data_len, c->local_window);
2320: xfree(data);
2321: return;
2322: }
1.70 markus 2323: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2324: c->local_window -= data_len;
2325: buffer_append(&c->extended, data, data_len);
2326: xfree(data);
2327: }
2328:
1.249 djm 2329: /* ARGSUSED */
1.49 markus 2330: void
1.154 markus 2331: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2332: {
2333: int id;
2334: Channel *c;
2335:
2336: id = packet_get_int();
1.152 markus 2337: packet_check_eom();
1.41 markus 2338: c = channel_lookup(id);
2339: if (c == NULL)
2340: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2341: chan_rcvd_ieof(c);
1.133 markus 2342:
2343: /* XXX force input close */
1.156 markus 2344: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2345: debug("channel %d: FORCE input drain", c->self);
2346: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2347: if (buffer_len(&c->input) == 0)
2348: chan_ibuf_empty(c);
1.133 markus 2349: }
2350:
1.41 markus 2351: }
1.1 deraadt 2352:
1.249 djm 2353: /* ARGSUSED */
1.49 markus 2354: void
1.154 markus 2355: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2356: {
1.41 markus 2357: int id;
2358: Channel *c;
1.1 deraadt 2359:
1.41 markus 2360: id = packet_get_int();
1.152 markus 2361: packet_check_eom();
1.41 markus 2362: c = channel_lookup(id);
2363: if (c == NULL)
2364: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2365:
2366: /*
2367: * Send a confirmation that we have closed the channel and no more
2368: * data is coming for it.
2369: */
1.25 markus 2370: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2371: packet_put_int(c->remote_id);
1.25 markus 2372: packet_send();
2373:
1.27 markus 2374: /*
2375: * If the channel is in closed state, we have sent a close request,
2376: * and the other side will eventually respond with a confirmation.
2377: * Thus, we cannot free the channel here, because then there would be
2378: * no-one to receive the confirmation. The channel gets freed when
2379: * the confirmation arrives.
2380: */
1.41 markus 2381: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2382: /*
2383: * Not a closed channel - mark it as draining, which will
2384: * cause it to be freed later.
2385: */
1.158 markus 2386: buffer_clear(&c->input);
1.41 markus 2387: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2388: }
1.1 deraadt 2389: }
2390:
1.41 markus 2391: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2392: /* ARGSUSED */
1.49 markus 2393: void
1.154 markus 2394: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2395: {
2396: int id = packet_get_int();
2397: Channel *c = channel_lookup(id);
1.151 markus 2398:
1.152 markus 2399: packet_check_eom();
1.41 markus 2400: if (c == NULL)
2401: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2402: chan_rcvd_oclose(c);
2403: }
1.1 deraadt 2404:
1.249 djm 2405: /* ARGSUSED */
1.49 markus 2406: void
1.154 markus 2407: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2408: {
1.41 markus 2409: int id = packet_get_int();
2410: Channel *c = channel_lookup(id);
1.1 deraadt 2411:
1.152 markus 2412: packet_check_eom();
1.41 markus 2413: if (c == NULL)
2414: packet_disconnect("Received close confirmation for "
2415: "out-of-range channel %d.", id);
2416: if (c->type != SSH_CHANNEL_CLOSED)
2417: packet_disconnect("Received close confirmation for "
2418: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2419: channel_free(c);
1.1 deraadt 2420: }
2421:
1.249 djm 2422: /* ARGSUSED */
1.49 markus 2423: void
1.154 markus 2424: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2425: {
1.41 markus 2426: int id, remote_id;
2427: Channel *c;
1.1 deraadt 2428:
1.41 markus 2429: id = packet_get_int();
2430: c = channel_lookup(id);
1.25 markus 2431:
1.41 markus 2432: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2433: packet_disconnect("Received open confirmation for "
2434: "non-opening channel %d.", id);
2435: remote_id = packet_get_int();
1.27 markus 2436: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2437: c->remote_id = remote_id;
2438: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2439:
2440: if (compat20) {
2441: c->remote_window = packet_get_int();
2442: c->remote_maxpacket = packet_get_int();
1.275 djm 2443: if (c->open_confirm) {
1.70 markus 2444: debug2("callback start");
1.304 ! djm 2445: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2446: debug2("callback done");
1.44 markus 2447: }
1.194 markus 2448: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2449: c->remote_window, c->remote_maxpacket);
2450: }
1.152 markus 2451: packet_check_eom();
1.1 deraadt 2452: }
2453:
1.127 itojun 2454: static char *
1.114 markus 2455: reason2txt(int reason)
2456: {
1.143 deraadt 2457: switch (reason) {
1.114 markus 2458: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2459: return "administratively prohibited";
2460: case SSH2_OPEN_CONNECT_FAILED:
2461: return "connect failed";
2462: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2463: return "unknown channel type";
2464: case SSH2_OPEN_RESOURCE_SHORTAGE:
2465: return "resource shortage";
2466: }
1.117 stevesk 2467: return "unknown reason";
1.114 markus 2468: }
2469:
1.249 djm 2470: /* ARGSUSED */
1.49 markus 2471: void
1.154 markus 2472: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2473: {
1.86 markus 2474: int id, reason;
2475: char *msg = NULL, *lang = NULL;
1.41 markus 2476: Channel *c;
2477:
2478: id = packet_get_int();
2479: c = channel_lookup(id);
1.25 markus 2480:
1.41 markus 2481: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2482: packet_disconnect("Received open failure for "
2483: "non-opening channel %d.", id);
1.44 markus 2484: if (compat20) {
1.86 markus 2485: reason = packet_get_int();
1.110 markus 2486: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2487: msg = packet_get_string(NULL);
2488: lang = packet_get_string(NULL);
2489: }
1.188 itojun 2490: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2491: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2492: if (msg != NULL)
2493: xfree(msg);
2494: if (lang != NULL)
2495: xfree(lang);
1.304 ! djm 2496: if (c->open_confirm) {
! 2497: debug2("callback start");
! 2498: c->open_confirm(c->self, 0, c->open_confirm_ctx);
! 2499: debug2("callback done");
! 2500: }
1.44 markus 2501: }
1.152 markus 2502: packet_check_eom();
1.291 djm 2503: /* Schedule the channel for cleanup/deletion. */
2504: chan_mark_dead(c);
1.44 markus 2505: }
2506:
1.249 djm 2507: /* ARGSUSED */
1.121 markus 2508: void
1.154 markus 2509: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2510: {
2511: Channel *c;
1.178 markus 2512: int id;
2513: u_int adjust;
1.121 markus 2514:
2515: if (!compat20)
2516: return;
2517:
2518: /* Get the channel number and verify it. */
2519: id = packet_get_int();
2520: c = channel_lookup(id);
1.1 deraadt 2521:
1.229 markus 2522: if (c == NULL) {
2523: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2524: return;
2525: }
2526: adjust = packet_get_int();
1.152 markus 2527: packet_check_eom();
1.178 markus 2528: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2529: c->remote_window += adjust;
2530: }
1.1 deraadt 2531:
1.249 djm 2532: /* ARGSUSED */
1.121 markus 2533: void
1.154 markus 2534: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2535: {
1.121 markus 2536: Channel *c = NULL;
2537: u_short host_port;
2538: char *host, *originator_string;
1.276 djm 2539: int remote_id;
1.121 markus 2540:
2541: remote_id = packet_get_int();
2542: host = packet_get_string(NULL);
2543: host_port = packet_get_int();
1.25 markus 2544:
1.121 markus 2545: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2546: originator_string = packet_get_string(NULL);
2547: } else {
2548: originator_string = xstrdup("unknown (remote did not supply name)");
2549: }
1.152 markus 2550: packet_check_eom();
1.276 djm 2551: c = channel_connect_to(host, host_port,
2552: "connected socket", originator_string);
1.190 markus 2553: xfree(originator_string);
1.276 djm 2554: xfree(host);
1.121 markus 2555: if (c == NULL) {
2556: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2557: packet_put_int(remote_id);
2558: packet_send();
1.276 djm 2559: } else
2560: c->remote_id = remote_id;
1.1 deraadt 2561: }
2562:
1.275 djm 2563: /* ARGSUSED */
2564: void
2565: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2566: {
2567: Channel *c;
2568: struct channel_confirm *cc;
1.289 markus 2569: int id;
1.275 djm 2570:
2571: /* Reset keepalive timeout */
1.296 andreas 2572: packet_set_alive_timeouts(0);
1.275 djm 2573:
1.289 markus 2574: id = packet_get_int();
1.275 djm 2575: packet_check_eom();
2576:
1.289 markus 2577: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2578:
1.289 markus 2579: if ((c = channel_lookup(id)) == NULL) {
2580: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2581: return;
2582: }
2583: ;
2584: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2585: return;
2586: cc->cb(type, c, cc->ctx);
2587: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2588: bzero(cc, sizeof(*cc));
2589: xfree(cc);
2590: }
1.121 markus 2591:
2592: /* -- tcp forwarding */
1.135 markus 2593:
2594: void
2595: channel_set_af(int af)
2596: {
2597: IPv4or6 = af;
2598: }
1.121 markus 2599:
1.160 markus 2600: static int
1.295 djm 2601: channel_setup_fwd_listener(int type, const char *listen_addr,
2602: u_short listen_port, int *allocated_listen_port,
1.160 markus 2603: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2604: {
1.113 markus 2605: Channel *c;
1.226 djm 2606: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2607: struct addrinfo hints, *ai, *aitop;
1.212 djm 2608: const char *host, *addr;
1.35 markus 2609: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2610: in_port_t *lport_p;
1.25 markus 2611:
1.160 markus 2612: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2613: listen_addr : host_to_connect;
1.212 djm 2614: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2615:
1.160 markus 2616: if (host == NULL) {
2617: error("No forward host name.");
1.218 markus 2618: return 0;
1.73 markus 2619: }
1.294 djm 2620: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2621: error("Forward host name too long.");
1.218 markus 2622: return 0;
1.87 markus 2623: }
1.25 markus 2624:
1.28 markus 2625: /*
1.212 djm 2626: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2627: * specified address or wildcard. On the client, a specified bind
2628: * address will always override gateway_ports. On the server, a
2629: * gateway_ports of 1 (``yes'') will override the client's
2630: * specification and force a wildcard bind, whereas a value of 2
2631: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2632: * asked for.
2633: *
2634: * Special-case listen_addrs are:
2635: *
2636: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2637: * "" (empty string), "*" -> wildcard v4/v6
2638: * "localhost" -> loopback v4/v6
2639: */
2640: addr = NULL;
2641: if (listen_addr == NULL) {
2642: /* No address specified: default to gateway_ports setting */
2643: if (gateway_ports)
2644: wildcard = 1;
2645: } else if (gateway_ports || is_client) {
2646: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
1.272 djm 2647: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
1.212 djm 2648: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2649: (!is_client && gateway_ports == 1))
2650: wildcard = 1;
2651: else if (strcmp(listen_addr, "localhost") != 0)
2652: addr = listen_addr;
2653: }
2654:
2655: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2656: type, wildcard, (addr == NULL) ? "NULL" : addr);
2657:
2658: /*
1.35 markus 2659: * getaddrinfo returns a loopback address if the hostname is
2660: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2661: */
1.35 markus 2662: memset(&hints, 0, sizeof(hints));
2663: hints.ai_family = IPv4or6;
1.212 djm 2664: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2665: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2666: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2667: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2668: if (addr == NULL) {
2669: /* This really shouldn't happen */
2670: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2671: ssh_gai_strerror(r));
1.212 djm 2672: } else {
1.218 markus 2673: error("channel_setup_fwd_listener: "
1.271 dtucker 2674: "getaddrinfo(%.64s): %s", addr,
2675: ssh_gai_strerror(r));
1.212 djm 2676: }
1.218 markus 2677: return 0;
1.212 djm 2678: }
1.295 djm 2679: if (allocated_listen_port != NULL)
2680: *allocated_listen_port = 0;
1.35 markus 2681: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2682: switch (ai->ai_family) {
2683: case AF_INET:
2684: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2685: sin_port;
2686: break;
2687: case AF_INET6:
2688: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2689: sin6_port;
2690: break;
2691: default:
1.35 markus 2692: continue;
1.295 djm 2693: }
2694: /*
2695: * If allocating a port for -R forwards, then use the
2696: * same port for all address families.
2697: */
2698: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2699: allocated_listen_port != NULL && *allocated_listen_port > 0)
2700: *lport_p = htons(*allocated_listen_port);
2701:
1.35 markus 2702: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2703: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2704: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2705: continue;
2706: }
2707: /* Create a port to listen for the host. */
1.300 dtucker 2708: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2709: if (sock < 0) {
2710: /* this is no error since kernel may not support ipv6 */
2711: verbose("socket: %.100s", strerror(errno));
2712: continue;
2713: }
1.226 djm 2714:
2715: channel_set_reuseaddr(sock);
1.182 stevesk 2716:
1.295 djm 2717: debug("Local forwarding listening on %s port %s.",
2718: ntop, strport);
1.35 markus 2719:
2720: /* Bind the socket to the address. */
2721: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2722: /* address can be in use ipv6 address is already bound */
2723: verbose("bind: %.100s", strerror(errno));
2724: close(sock);
2725: continue;
2726: }
2727: /* Start listening for connections on the socket. */
1.199 markus 2728: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2729: error("listen: %.100s", strerror(errno));
2730: close(sock);
2731: continue;
2732: }
1.295 djm 2733:
2734: /*
2735: * listen_port == 0 requests a dynamically allocated port -
2736: * record what we got.
2737: */
2738: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2739: allocated_listen_port != NULL &&
2740: *allocated_listen_port == 0) {
2741: *allocated_listen_port = get_sock_port(sock, 1);
2742: debug("Allocated listen port %d",
2743: *allocated_listen_port);
2744: }
2745:
1.35 markus 2746: /* Allocate a channel number for the socket. */
1.121 markus 2747: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2748: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2749: 0, "port listener", 1);
1.293 djm 2750: c->path = xstrdup(host);
1.113 markus 2751: c->host_port = port_to_connect;
2752: c->listening_port = listen_port;
1.35 markus 2753: success = 1;
2754: }
2755: if (success == 0)
1.160 markus 2756: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2757: listen_port);
1.35 markus 2758: freeaddrinfo(aitop);
1.87 markus 2759: return success;
1.25 markus 2760: }
1.1 deraadt 2761:
1.202 djm 2762: int
2763: channel_cancel_rport_listener(const char *host, u_short port)
2764: {
1.209 avsm 2765: u_int i;
2766: int found = 0;
1.202 djm 2767:
1.213 deraadt 2768: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2769: Channel *c = channels[i];
2770:
2771: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
1.293 djm 2772: strcmp(c->path, host) == 0 && c->listening_port == port) {
1.210 djm 2773: debug2("%s: close channel %d", __func__, i);
1.202 djm 2774: channel_free(c);
2775: found = 1;
2776: }
2777: }
2778:
2779: return (found);
2780: }
2781:
1.160 markus 2782: /* protocol local port fwd, used by ssh (and sshd in v1) */
2783: int
1.212 djm 2784: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2785: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2786: {
2787: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2788: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2789: gateway_ports);
1.160 markus 2790: }
2791:
2792: /* protocol v2 remote port fwd, used by sshd */
2793: int
2794: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2795: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2796: {
2797: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2798: listen_address, listen_port, allocated_listen_port,
2799: NULL, 0, gateway_ports);
1.160 markus 2800: }
2801:
1.27 markus 2802: /*
2803: * Initiate forwarding of connections to port "port" on remote host through
2804: * the secure channel to host:port from local side.
2805: */
1.1 deraadt 2806:
1.253 markus 2807: int
1.212 djm 2808: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2809: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2810: {
1.153 markus 2811: int type, success = 0;
1.73 markus 2812:
1.25 markus 2813: /* Record locally that connection to this host/port is permitted. */
2814: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2815: fatal("channel_request_remote_forwarding: too many forwards");
2816:
2817: /* Send the forward request to the remote side. */
1.44 markus 2818: if (compat20) {
1.212 djm 2819: const char *address_to_bind;
1.267 djm 2820: if (listen_host == NULL) {
2821: if (datafellows & SSH_BUG_RFWD_ADDR)
2822: address_to_bind = "127.0.0.1";
2823: else
2824: address_to_bind = "localhost";
2825: } else if (*listen_host == '\0' ||
2826: strcmp(listen_host, "*") == 0) {
2827: if (datafellows & SSH_BUG_RFWD_ADDR)
2828: address_to_bind = "0.0.0.0";
2829: else
2830: address_to_bind = "";
2831: } else
1.212 djm 2832: address_to_bind = listen_host;
2833:
1.44 markus 2834: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2835: packet_put_cstring("tcpip-forward");
1.173 markus 2836: packet_put_char(1); /* boolean: want reply */
1.44 markus 2837: packet_put_cstring(address_to_bind);
2838: packet_put_int(listen_port);
1.73 markus 2839: packet_send();
2840: packet_write_wait();
2841: /* Assume that server accepts the request */
2842: success = 1;
1.44 markus 2843: } else {
2844: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2845: packet_put_int(listen_port);
2846: packet_put_cstring(host_to_connect);
1.44 markus 2847: packet_put_int(port_to_connect);
2848: packet_send();
2849: packet_write_wait();
1.73 markus 2850:
2851: /* Wait for response from the remote side. */
1.153 markus 2852: type = packet_read();
1.73 markus 2853: switch (type) {
2854: case SSH_SMSG_SUCCESS:
2855: success = 1;
2856: break;
2857: case SSH_SMSG_FAILURE:
2858: break;
2859: default:
2860: /* Unknown packet */
2861: packet_disconnect("Protocol error for port forward request:"
2862: "received packet type %d.", type);
2863: }
2864: }
2865: if (success) {
2866: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2867: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2868: permitted_opens[num_permitted_opens].listen_port = listen_port;
2869: num_permitted_opens++;
1.44 markus 2870: }
1.253 markus 2871: return (success ? 0 : -1);
1.1 deraadt 2872: }
2873:
1.27 markus 2874: /*
1.208 deraadt 2875: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2876: * local side.
2877: */
2878: void
1.212 djm 2879: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2880: {
2881: int i;
2882:
2883: if (!compat20)
2884: return;
2885:
2886: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2887: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2888: permitted_opens[i].listen_port == port)
2889: break;
2890: }
2891: if (i >= num_permitted_opens) {
2892: debug("%s: requested forward not found", __func__);
2893: return;
2894: }
2895: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2896: packet_put_cstring("cancel-tcpip-forward");
2897: packet_put_char(0);
1.212 djm 2898: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2899: packet_put_int(port);
2900: packet_send();
2901:
2902: permitted_opens[i].listen_port = 0;
2903: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2904: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2905: permitted_opens[i].host_to_connect = NULL;
2906: }
2907:
2908: /*
1.27 markus 2909: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2910: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2911: * message if there was an error).
1.27 markus 2912: */
1.253 markus 2913: int
1.56 markus 2914: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2915: {
1.31 markus 2916: u_short port, host_port;
1.253 markus 2917: int success = 0;
1.25 markus 2918: char *hostname;
1.1 deraadt 2919:
1.25 markus 2920: /* Get arguments from the packet. */
2921: port = packet_get_int();
2922: hostname = packet_get_string(NULL);
2923: host_port = packet_get_int();
2924:
1.27 markus 2925: /*
2926: * Check that an unprivileged user is not trying to forward a
2927: * privileged port.
2928: */
1.25 markus 2929: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2930: packet_disconnect(
2931: "Requested forwarding of port %d but user is not root.",
2932: port);
2933: if (host_port == 0)
2934: packet_disconnect("Dynamic forwarding denied.");
2935:
1.73 markus 2936: /* Initiate forwarding */
1.253 markus 2937: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2938: host_port, gateway_ports);
1.25 markus 2939:
2940: /* Free the argument string. */
2941: xfree(hostname);
1.253 markus 2942:
2943: return (success ? 0 : -1);
1.1 deraadt 2944: }
2945:
1.99 markus 2946: /*
2947: * Permits opening to any host/port if permitted_opens[] is empty. This is
2948: * usually called by the server, because the user could connect to any port
2949: * anyway, and the server has no way to know but to trust the client anyway.
2950: */
2951: void
1.142 itojun 2952: channel_permit_all_opens(void)
1.99 markus 2953: {
2954: if (num_permitted_opens == 0)
2955: all_opens_permitted = 1;
2956: }
2957:
1.101 markus 2958: void
1.99 markus 2959: channel_add_permitted_opens(char *host, int port)
2960: {
2961: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1.253 markus 2962: fatal("channel_add_permitted_opens: too many forwards");
1.99 markus 2963: debug("allow port forwarding to host %s port %d", host, port);
2964:
2965: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2966: permitted_opens[num_permitted_opens].port_to_connect = port;
2967: num_permitted_opens++;
2968:
2969: all_opens_permitted = 0;
2970: }
2971:
1.258 dtucker 2972: int
1.257 dtucker 2973: channel_add_adm_permitted_opens(char *host, int port)
2974: {
2975: if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2976: fatal("channel_add_adm_permitted_opens: too many forwards");
1.258 dtucker 2977: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 2978:
2979: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2980: = xstrdup(host);
2981: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 2982: return ++num_adm_permitted_opens;
1.257 dtucker 2983: }
2984:
2985: void
1.99 markus 2986: channel_clear_permitted_opens(void)
2987: {
2988: int i;
2989:
2990: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2991: if (permitted_opens[i].host_to_connect != NULL)
2992: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2993: num_permitted_opens = 0;
1.257 dtucker 2994: }
2995:
2996: void
2997: channel_clear_adm_permitted_opens(void)
2998: {
2999: int i;
1.99 markus 3000:
1.257 dtucker 3001: for (i = 0; i < num_adm_permitted_opens; i++)
3002: if (permitted_adm_opens[i].host_to_connect != NULL)
3003: xfree(permitted_adm_opens[i].host_to_connect);
3004: num_adm_permitted_opens = 0;
1.278 dtucker 3005: }
3006:
3007: void
3008: channel_print_adm_permitted_opens(void)
3009: {
1.286 djm 3010: int i;
1.278 dtucker 3011:
1.290 stevesk 3012: printf("permitopen");
1.288 stevesk 3013: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3014: printf(" any\n");
1.288 stevesk 3015: return;
3016: }
1.278 dtucker 3017: for (i = 0; i < num_adm_permitted_opens; i++)
3018: if (permitted_adm_opens[i].host_to_connect != NULL)
3019: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3020: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3021: printf("\n");
1.99 markus 3022: }
3023:
1.276 djm 3024: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3025: static int
1.276 djm 3026: connect_next(struct channel_connect *cctx)
1.41 markus 3027: {
1.276 djm 3028: int sock, saved_errno;
1.41 markus 3029: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3030:
1.276 djm 3031: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3032: if (cctx->ai->ai_family != AF_INET &&
3033: cctx->ai->ai_family != AF_INET6)
1.41 markus 3034: continue;
1.276 djm 3035: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3036: ntop, sizeof(ntop), strport, sizeof(strport),
3037: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3038: error("connect_next: getnameinfo failed");
1.41 markus 3039: continue;
3040: }
1.300 dtucker 3041: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3042: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3043: if (cctx->ai->ai_next == NULL)
1.186 djm 3044: error("socket: %.100s", strerror(errno));
3045: else
3046: verbose("socket: %.100s", strerror(errno));
1.41 markus 3047: continue;
3048: }
1.205 djm 3049: if (set_nonblock(sock) == -1)
3050: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3051: if (connect(sock, cctx->ai->ai_addr,
3052: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3053: debug("connect_next: host %.100s ([%.100s]:%s): "
3054: "%.100s", cctx->host, ntop, strport,
1.41 markus 3055: strerror(errno));
1.276 djm 3056: saved_errno = errno;
1.41 markus 3057: close(sock);
1.276 djm 3058: errno = saved_errno;
1.89 stevesk 3059: continue; /* fail -- try next */
1.41 markus 3060: }
1.276 djm 3061: debug("connect_next: host %.100s ([%.100s]:%s) "
3062: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3063: cctx->ai = cctx->ai->ai_next;
3064: set_nodelay(sock);
3065: return sock;
3066: }
3067: return -1;
3068: }
1.41 markus 3069:
1.276 djm 3070: static void
3071: channel_connect_ctx_free(struct channel_connect *cctx)
3072: {
3073: xfree(cctx->host);
3074: if (cctx->aitop)
3075: freeaddrinfo(cctx->aitop);
3076: bzero(cctx, sizeof(*cctx));
3077: cctx->host = NULL;
3078: cctx->ai = cctx->aitop = NULL;
3079: }
3080:
3081: /* Return CONNECTING channel to remote host, port */
3082: static Channel *
3083: connect_to(const char *host, u_short port, char *ctype, char *rname)
3084: {
3085: struct addrinfo hints;
3086: int gaierr;
3087: int sock = -1;
3088: char strport[NI_MAXSERV];
3089: struct channel_connect cctx;
3090: Channel *c;
3091:
1.284 djm 3092: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3093: memset(&hints, 0, sizeof(hints));
3094: hints.ai_family = IPv4or6;
3095: hints.ai_socktype = SOCK_STREAM;
3096: snprintf(strport, sizeof strport, "%d", port);
3097: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3098: error("connect_to %.100s: unknown host (%s)", host,
3099: ssh_gai_strerror(gaierr));
3100: return NULL;
1.41 markus 3101: }
1.276 djm 3102:
3103: cctx.host = xstrdup(host);
3104: cctx.port = port;
3105: cctx.ai = cctx.aitop;
3106:
3107: if ((sock = connect_next(&cctx)) == -1) {
3108: error("connect to %.100s port %d failed: %s",
3109: host, port, strerror(errno));
3110: channel_connect_ctx_free(&cctx);
3111: return NULL;
1.41 markus 3112: }
1.276 djm 3113: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3114: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3115: c->connect_ctx = cctx;
3116: return c;
1.41 markus 3117: }
1.99 markus 3118:
1.276 djm 3119: Channel *
3120: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3121: {
3122: int i;
1.99 markus 3123:
1.276 djm 3124: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3125: if (permitted_opens[i].host_to_connect != NULL &&
1.276 djm 3126: permitted_opens[i].listen_port == listen_port) {
1.99 markus 3127: return connect_to(
1.73 markus 3128: permitted_opens[i].host_to_connect,
1.276 djm 3129: permitted_opens[i].port_to_connect, ctype, rname);
3130: }
3131: }
1.74 markus 3132: error("WARNING: Server requests forwarding for unknown listen_port %d",
3133: listen_port);
1.276 djm 3134: return NULL;
1.73 markus 3135: }
3136:
1.99 markus 3137: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3138: Channel *
3139: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3140: {
1.257 dtucker 3141: int i, permit, permit_adm = 1;
1.99 markus 3142:
3143: permit = all_opens_permitted;
3144: if (!permit) {
3145: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3146: if (permitted_opens[i].host_to_connect != NULL &&
3147: permitted_opens[i].port_to_connect == port &&
1.99 markus 3148: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3149: permit = 1;
1.257 dtucker 3150: }
1.99 markus 3151:
1.257 dtucker 3152: if (num_adm_permitted_opens > 0) {
3153: permit_adm = 0;
3154: for (i = 0; i < num_adm_permitted_opens; i++)
3155: if (permitted_adm_opens[i].host_to_connect != NULL &&
3156: permitted_adm_opens[i].port_to_connect == port &&
3157: strcmp(permitted_adm_opens[i].host_to_connect, host)
3158: == 0)
3159: permit_adm = 1;
1.99 markus 3160: }
1.257 dtucker 3161:
3162: if (!permit || !permit_adm) {
1.188 itojun 3163: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3164: "but the request was denied.", host, port);
1.276 djm 3165: return NULL;
1.99 markus 3166: }
1.276 djm 3167: return connect_to(host, port, ctype, rname);
1.204 djm 3168: }
3169:
3170: void
3171: channel_send_window_changes(void)
3172: {
1.209 avsm 3173: u_int i;
1.204 djm 3174: struct winsize ws;
3175:
3176: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3177: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3178: channels[i]->type != SSH_CHANNEL_OPEN)
3179: continue;
3180: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3181: continue;
3182: channel_request_start(i, "window-change", 0);
1.238 deraadt 3183: packet_put_int((u_int)ws.ws_col);
3184: packet_put_int((u_int)ws.ws_row);
3185: packet_put_int((u_int)ws.ws_xpixel);
3186: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3187: packet_send();
3188: }
1.99 markus 3189: }
3190:
1.121 markus 3191: /* -- X11 forwarding */
1.1 deraadt 3192:
1.27 markus 3193: /*
3194: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3195: * Returns 0 and a suitable display number for the DISPLAY variable
3196: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3197: */
1.141 stevesk 3198: int
1.163 stevesk 3199: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3200: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3201: {
1.149 markus 3202: Channel *nc = NULL;
1.31 markus 3203: int display_number, sock;
3204: u_short port;
1.35 markus 3205: struct addrinfo hints, *ai, *aitop;
3206: char strport[NI_MAXSERV];
3207: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3208:
1.224 markus 3209: if (chanids == NULL)
3210: return -1;
3211:
1.33 markus 3212: for (display_number = x11_display_offset;
1.148 deraadt 3213: display_number < MAX_DISPLAYS;
3214: display_number++) {
1.25 markus 3215: port = 6000 + display_number;
1.35 markus 3216: memset(&hints, 0, sizeof(hints));
3217: hints.ai_family = IPv4or6;
1.163 stevesk 3218: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3219: hints.ai_socktype = SOCK_STREAM;
3220: snprintf(strport, sizeof strport, "%d", port);
3221: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3222: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3223: return -1;
1.25 markus 3224: }
1.35 markus 3225: for (ai = aitop; ai; ai = ai->ai_next) {
3226: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3227: continue;
1.300 dtucker 3228: sock = socket(ai->ai_family, ai->ai_socktype,
3229: ai->ai_protocol);
1.35 markus 3230: if (sock < 0) {
3231: error("socket: %.100s", strerror(errno));
1.203 markus 3232: freeaddrinfo(aitop);
1.141 stevesk 3233: return -1;
1.35 markus 3234: }
1.226 djm 3235: channel_set_reuseaddr(sock);
1.35 markus 3236: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3237: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3238: close(sock);
1.183 itojun 3239:
1.35 markus 3240: for (n = 0; n < num_socks; n++) {
3241: close(socks[n]);
3242: }
3243: num_socks = 0;
3244: break;
3245: }
3246: socks[num_socks++] = sock;
3247: if (num_socks == NUM_SOCKS)
3248: break;
1.25 markus 3249: }
1.83 stevesk 3250: freeaddrinfo(aitop);
1.35 markus 3251: if (num_socks > 0)
3252: break;
1.25 markus 3253: }
3254: if (display_number >= MAX_DISPLAYS) {
3255: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3256: return -1;
1.25 markus 3257: }
3258: /* Start listening for connections on the socket. */
1.35 markus 3259: for (n = 0; n < num_socks; n++) {
3260: sock = socks[n];
1.199 markus 3261: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3262: error("listen: %.100s", strerror(errno));
3263: close(sock);
1.141 stevesk 3264: return -1;
1.35 markus 3265: }
1.25 markus 3266: }
1.35 markus 3267:
3268: /* Allocate a channel for each socket. */
1.242 djm 3269: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3270: for (n = 0; n < num_socks; n++) {
3271: sock = socks[n];
1.149 markus 3272: nc = channel_new("x11 listener",
1.51 markus 3273: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3274: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3275: 0, "X11 inet listener", 1);
1.167 markus 3276: nc->single_connection = single_connection;
1.224 markus 3277: (*chanids)[n] = nc->self;
1.35 markus 3278: }
1.224 markus 3279: (*chanids)[n] = -1;
1.1 deraadt 3280:
1.141 stevesk 3281: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3282: *display_numberp = display_number;
3283: return (0);
1.1 deraadt 3284: }
3285:
1.127 itojun 3286: static int
1.77 markus 3287: connect_local_xsocket(u_int dnr)
1.1 deraadt 3288: {
1.25 markus 3289: int sock;
3290: struct sockaddr_un addr;
3291:
1.147 stevesk 3292: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3293: if (sock < 0)
3294: error("socket: %.100s", strerror(errno));
3295: memset(&addr, 0, sizeof(addr));
3296: addr.sun_family = AF_UNIX;
3297: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3298: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3299: return sock;
3300: close(sock);
1.25 markus 3301: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3302: return -1;
1.1 deraadt 3303: }
3304:
1.51 markus 3305: int
3306: x11_connect_display(void)
1.1 deraadt 3307: {
1.248 deraadt 3308: u_int display_number;
1.25 markus 3309: const char *display;
1.51 markus 3310: char buf[1024], *cp;
1.35 markus 3311: struct addrinfo hints, *ai, *aitop;
3312: char strport[NI_MAXSERV];
1.248 deraadt 3313: int gaierr, sock = 0;
1.25 markus 3314:
3315: /* Try to open a socket for the local X server. */
3316: display = getenv("DISPLAY");
3317: if (!display) {
3318: error("DISPLAY not set.");
1.51 markus 3319: return -1;
1.25 markus 3320: }
1.27 markus 3321: /*
3322: * Now we decode the value of the DISPLAY variable and make a
3323: * connection to the real X server.
3324: */
3325:
3326: /*
3327: * Check if it is a unix domain socket. Unix domain displays are in
3328: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3329: */
1.25 markus 3330: if (strncmp(display, "unix:", 5) == 0 ||
3331: display[0] == ':') {
3332: /* Connect to the unix domain socket. */
1.248 deraadt 3333: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3334: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3335: display);
1.51 markus 3336: return -1;
1.25 markus 3337: }
3338: /* Create a socket. */
3339: sock = connect_local_xsocket(display_number);
3340: if (sock < 0)
1.51 markus 3341: return -1;
1.25 markus 3342:
3343: /* OK, we now have a connection to the display. */
1.51 markus 3344: return sock;
1.25 markus 3345: }
1.27 markus 3346: /*
3347: * Connect to an inet socket. The DISPLAY value is supposedly
3348: * hostname:d[.s], where hostname may also be numeric IP address.
3349: */
1.145 stevesk 3350: strlcpy(buf, display, sizeof(buf));
1.25 markus 3351: cp = strchr(buf, ':');
3352: if (!cp) {
3353: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3354: return -1;
1.25 markus 3355: }
3356: *cp = 0;
1.27 markus 3357: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3358: if (sscanf(cp + 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: }
1.35 markus 3363:
3364: /* Look up the host address */
3365: memset(&hints, 0, sizeof(hints));
3366: hints.ai_family = IPv4or6;
3367: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3368: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3369: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3370: error("%.100s: unknown host. (%s)", buf,
3371: ssh_gai_strerror(gaierr));
1.51 markus 3372: return -1;
1.25 markus 3373: }
1.35 markus 3374: for (ai = aitop; ai; ai = ai->ai_next) {
3375: /* Create a socket. */
1.300 dtucker 3376: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3377: if (sock < 0) {
1.194 markus 3378: debug2("socket: %.100s", strerror(errno));
1.41 markus 3379: continue;
3380: }
3381: /* Connect it to the display. */
3382: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3383: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3384: 6000 + display_number, strerror(errno));
3385: close(sock);
3386: continue;
3387: }
3388: /* Success */
3389: break;
1.35 markus 3390: }
3391: freeaddrinfo(aitop);
3392: if (!ai) {
1.248 deraadt 3393: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3394: strerror(errno));
1.51 markus 3395: return -1;
1.25 markus 3396: }
1.162 stevesk 3397: set_nodelay(sock);
1.51 markus 3398: return sock;
3399: }
3400:
3401: /*
3402: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3403: * the remote channel number. We should do whatever we want, and respond
3404: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3405: */
3406:
1.259 stevesk 3407: /* ARGSUSED */
1.51 markus 3408: void
1.154 markus 3409: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3410: {
1.113 markus 3411: Channel *c = NULL;
3412: int remote_id, sock = 0;
1.51 markus 3413: char *remote_host;
1.25 markus 3414:
1.113 markus 3415: debug("Received X11 open request.");
1.51 markus 3416:
1.113 markus 3417: remote_id = packet_get_int();
1.121 markus 3418:
3419: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3420: remote_host = packet_get_string(NULL);
1.51 markus 3421: } else {
3422: remote_host = xstrdup("unknown (remote did not supply name)");
3423: }
1.152 markus 3424: packet_check_eom();
1.25 markus 3425:
1.51 markus 3426: /* Obtain a connection to the real X display. */
3427: sock = x11_connect_display();
1.113 markus 3428: if (sock != -1) {
3429: /* Allocate a channel for this connection. */
3430: c = channel_new("connected x11 socket",
3431: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3432: remote_host, 1);
1.167 markus 3433: c->remote_id = remote_id;
3434: c->force_drain = 1;
1.113 markus 3435: }
1.190 markus 3436: xfree(remote_host);
1.113 markus 3437: if (c == NULL) {
1.51 markus 3438: /* Send refusal to the remote host. */
3439: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3440: packet_put_int(remote_id);
1.51 markus 3441: } else {
3442: /* Send a confirmation to the remote host. */
3443: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3444: packet_put_int(remote_id);
3445: packet_put_int(c->self);
1.51 markus 3446: }
1.113 markus 3447: packet_send();
1.72 markus 3448: }
3449:
3450: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3451: /* ARGSUSED */
1.72 markus 3452: void
1.154 markus 3453: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3454: {
3455: int rchan = packet_get_int();
1.180 deraadt 3456:
1.143 deraadt 3457: switch (type) {
1.72 markus 3458: case SSH_SMSG_AGENT_OPEN:
3459: error("Warning: ssh server tried agent forwarding.");
3460: break;
3461: case SSH_SMSG_X11_OPEN:
3462: error("Warning: ssh server tried X11 forwarding.");
3463: break;
3464: default:
1.154 markus 3465: error("deny_input_open: type %d", type);
1.72 markus 3466: break;
3467: }
1.230 stevesk 3468: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3469: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3470: packet_put_int(rchan);
3471: packet_send();
1.1 deraadt 3472: }
3473:
1.27 markus 3474: /*
3475: * Requests forwarding of X11 connections, generates fake authentication
3476: * data, and enables authentication spoofing.
1.121 markus 3477: * This should be called in the client only.
1.27 markus 3478: */
1.49 markus 3479: void
1.215 djm 3480: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3481: const char *proto, const char *data)
1.1 deraadt 3482: {
1.77 markus 3483: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3484: u_int i, value;
1.25 markus 3485: char *new_data;
3486: int screen_number;
3487: const char *cp;
1.207 avsm 3488: u_int32_t rnd = 0;
1.25 markus 3489:
1.220 markus 3490: if (x11_saved_display == NULL)
3491: x11_saved_display = xstrdup(disp);
3492: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3493: error("x11_request_forwarding_with_spoofing: different "
3494: "$DISPLAY already forwarded");
3495: return;
3496: }
3497:
1.266 djm 3498: cp = strchr(disp, ':');
1.25 markus 3499: if (cp)
3500: cp = strchr(cp, '.');
3501: if (cp)
1.245 deraadt 3502: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3503: else
3504: screen_number = 0;
3505:
1.219 djm 3506: if (x11_saved_proto == NULL) {
3507: /* Save protocol name. */
3508: x11_saved_proto = xstrdup(proto);
3509: /*
1.221 djm 3510: * Extract real authentication data and generate fake data
1.219 djm 3511: * of the same length.
3512: */
3513: x11_saved_data = xmalloc(data_len);
3514: x11_fake_data = xmalloc(data_len);
3515: for (i = 0; i < data_len; i++) {
3516: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3517: fatal("x11_request_forwarding: bad "
3518: "authentication data: %.100s", data);
3519: if (i % 4 == 0)
3520: rnd = arc4random();
3521: x11_saved_data[i] = value;
3522: x11_fake_data[i] = rnd & 0xff;
3523: rnd >>= 8;
3524: }
3525: x11_saved_data_len = data_len;
3526: x11_fake_data_len = data_len;
1.25 markus 3527: }
3528:
3529: /* Convert the fake data into hex. */
1.219 djm 3530: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3531:
3532: /* Send the request packet. */
1.51 markus 3533: if (compat20) {
3534: channel_request_start(client_session_id, "x11-req", 0);
3535: packet_put_char(0); /* XXX bool single connection */
3536: } else {
3537: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3538: }
3539: packet_put_cstring(proto);
3540: packet_put_cstring(new_data);
1.25 markus 3541: packet_put_int(screen_number);
3542: packet_send();
3543: packet_write_wait();
3544: xfree(new_data);
1.1 deraadt 3545: }
3546:
1.121 markus 3547:
3548: /* -- agent forwarding */
3549:
1.1 deraadt 3550: /* Sends a message to the server to request authentication fd forwarding. */
3551:
1.49 markus 3552: void
1.142 itojun 3553: auth_request_forwarding(void)
1.1 deraadt 3554: {
1.25 markus 3555: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3556: packet_send();
3557: packet_write_wait();
1.1 deraadt 3558: }
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