Annotation of src/usr.bin/ssh/channels.c, Revision 1.311
1.311 ! djm 1: /* $OpenBSD: channels.c,v 1.310 2010/11/24 01:24:14 djm Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
1.265 deraadt 42: #include <sys/types.h>
1.234 stevesk 43: #include <sys/ioctl.h>
1.235 stevesk 44: #include <sys/un.h>
1.251 stevesk 45: #include <sys/socket.h>
1.261 stevesk 46: #include <sys/time.h>
1.275 djm 47: #include <sys/queue.h>
1.251 stevesk 48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.298 dtucker 53: #include <fcntl.h>
1.255 stevesk 54: #include <netdb.h>
1.263 stevesk 55: #include <stdio.h>
1.262 stevesk 56: #include <stdlib.h>
1.260 stevesk 57: #include <string.h>
1.233 stevesk 58: #include <termios.h>
1.256 stevesk 59: #include <unistd.h>
1.265 deraadt 60: #include <stdarg.h>
1.1 deraadt 61:
1.265 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.82 markus 64: #include "ssh1.h"
65: #include "ssh2.h"
1.1 deraadt 66: #include "packet.h"
1.82 markus 67: #include "log.h"
68: #include "misc.h"
1.265 deraadt 69: #include "buffer.h"
1.14 markus 70: #include "channels.h"
71: #include "compat.h"
1.82 markus 72: #include "canohost.h"
1.64 markus 73: #include "key.h"
74: #include "authfd.h"
1.147 stevesk 75: #include "pathnames.h"
1.1 deraadt 76:
1.121 markus 77: /* -- channel core */
1.12 markus 78:
1.27 markus 79: /*
80: * Pointer to an array containing all allocated channels. The array is
81: * dynamically extended as needed.
82: */
1.113 markus 83: static Channel **channels = NULL;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Size of the channel array. All slots of the array must always be
1.113 markus 87: * initialized (at least the type field); unused slots set to NULL
1.27 markus 88: */
1.209 avsm 89: static u_int channels_alloc = 0;
1.1 deraadt 90:
1.27 markus 91: /*
92: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 93: * updated in channel_new.
1.27 markus 94: */
1.84 markus 95: static int channel_max_fd = 0;
1.1 deraadt 96:
97:
1.121 markus 98: /* -- tcp forwarding */
1.1 deraadt 99:
1.27 markus 100: /*
101: * Data structure for storing which hosts are permitted for forward requests.
102: * The local sides of any remote forwards are stored in this array to prevent
103: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
104: * network (which might be behind a firewall).
105: */
1.25 markus 106: typedef struct {
1.41 markus 107: char *host_to_connect; /* Connect to 'host'. */
108: u_short port_to_connect; /* Connect to 'port'. */
109: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 110: } ForwardPermission;
111:
1.257 dtucker 112: /* List of all permitted host/port pairs to connect by the user. */
1.305 djm 113: static ForwardPermission *permitted_opens = NULL;
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
1.305 djm 116: static ForwardPermission *permitted_adm_opens = NULL;
1.257 dtucker 117:
118: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 119: static int num_permitted_opens = 0;
1.257 dtucker 120:
121: /* Number of permitted host/port pair in the array permitted by the admin. */
122: static int num_adm_permitted_opens = 0;
123:
1.27 markus 124: /*
125: * If this is true, all opens are permitted. This is the case on the server
126: * on which we have to trust the client anyway, and the user could do
127: * anything after logging in anyway.
128: */
1.1 deraadt 129: static int all_opens_permitted = 0;
130:
1.121 markus 131:
132: /* -- X11 forwarding */
133:
134: /* Maximum number of fake X11 displays to try. */
135: #define MAX_DISPLAYS 1000
136:
1.219 djm 137: /* Saved X11 local (client) display. */
138: static char *x11_saved_display = NULL;
139:
1.121 markus 140: /* Saved X11 authentication protocol name. */
141: static char *x11_saved_proto = NULL;
142:
143: /* Saved X11 authentication data. This is the real data. */
144: static char *x11_saved_data = NULL;
145: static u_int x11_saved_data_len = 0;
146:
147: /*
148: * Fake X11 authentication data. This is what the server will be sending us;
149: * we should replace any occurrences of this by the real data.
150: */
1.240 deraadt 151: static u_char *x11_fake_data = NULL;
1.121 markus 152: static u_int x11_fake_data_len;
153:
154:
155: /* -- agent forwarding */
156:
157: #define NUM_SOCKS 10
158:
1.82 markus 159: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 160: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 161:
1.121 markus 162: /* helper */
1.127 itojun 163: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 164:
1.276 djm 165: /* non-blocking connect helpers */
166: static int connect_next(struct channel_connect *);
167: static void channel_connect_ctx_free(struct channel_connect *);
168:
1.121 markus 169: /* -- channel core */
1.41 markus 170:
171: Channel *
1.229 markus 172: channel_by_id(int id)
1.41 markus 173: {
174: Channel *c;
1.113 markus 175:
1.209 avsm 176: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 177: logit("channel_by_id: %d: bad id", id);
1.41 markus 178: return NULL;
179: }
1.113 markus 180: c = channels[id];
181: if (c == NULL) {
1.229 markus 182: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 183: return NULL;
184: }
185: return c;
1.55 markus 186: }
187:
1.27 markus 188: /*
1.229 markus 189: * Returns the channel if it is allowed to receive protocol messages.
190: * Private channels, like listening sockets, may not receive messages.
191: */
192: Channel *
193: channel_lookup(int id)
194: {
195: Channel *c;
196:
197: if ((c = channel_by_id(id)) == NULL)
198: return (NULL);
199:
1.237 deraadt 200: switch (c->type) {
1.229 markus 201: case SSH_CHANNEL_X11_OPEN:
202: case SSH_CHANNEL_LARVAL:
203: case SSH_CHANNEL_CONNECTING:
204: case SSH_CHANNEL_DYNAMIC:
205: case SSH_CHANNEL_OPENING:
206: case SSH_CHANNEL_OPEN:
207: case SSH_CHANNEL_INPUT_DRAINING:
208: case SSH_CHANNEL_OUTPUT_DRAINING:
209: return (c);
210: }
211: logit("Non-public channel %d, type %d.", id, c->type);
212: return (NULL);
213: }
214:
215: /*
1.55 markus 216: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 217: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 218: */
1.127 itojun 219: static void
1.71 markus 220: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 221: int extusage, int nonblock, int is_tty)
1.1 deraadt 222: {
1.25 markus 223: /* Update the maximum file descriptor value. */
1.84 markus 224: channel_max_fd = MAX(channel_max_fd, rfd);
225: channel_max_fd = MAX(channel_max_fd, wfd);
226: channel_max_fd = MAX(channel_max_fd, efd);
227:
1.298 dtucker 228: if (rfd != -1)
229: fcntl(rfd, F_SETFD, FD_CLOEXEC);
230: if (wfd != -1 && wfd != rfd)
231: fcntl(wfd, F_SETFD, FD_CLOEXEC);
232: if (efd != -1 && efd != rfd && efd != wfd)
233: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 234:
1.52 markus 235: c->rfd = rfd;
236: c->wfd = wfd;
237: c->sock = (rfd == wfd) ? rfd : -1;
238: c->efd = efd;
239: c->extended_usage = extusage;
1.71 markus 240:
1.282 dtucker 241: if ((c->isatty = is_tty) != 0)
1.194 markus 242: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 243:
1.71 markus 244: /* enable nonblocking mode */
245: if (nonblock) {
246: if (rfd != -1)
247: set_nonblock(rfd);
248: if (wfd != -1)
249: set_nonblock(wfd);
250: if (efd != -1)
251: set_nonblock(efd);
252: }
1.52 markus 253: }
254:
255: /*
256: * Allocate a new channel object and set its type and socket. This will cause
257: * remote_name to be freed.
258: */
1.113 markus 259: Channel *
1.52 markus 260: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 261: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 262: {
1.209 avsm 263: int found;
264: u_int i;
1.52 markus 265: Channel *c;
1.25 markus 266:
267: /* Do initial allocation if this is the first call. */
268: if (channels_alloc == 0) {
269: channels_alloc = 10;
1.242 djm 270: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 271: for (i = 0; i < channels_alloc; i++)
1.113 markus 272: channels[i] = NULL;
1.25 markus 273: }
274: /* Try to find a free slot where to put the new channel. */
275: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 276: if (channels[i] == NULL) {
1.25 markus 277: /* Found a free slot. */
1.209 avsm 278: found = (int)i;
1.25 markus 279: break;
280: }
1.209 avsm 281: if (found < 0) {
1.27 markus 282: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 283: found = channels_alloc;
1.179 markus 284: if (channels_alloc > 10000)
285: fatal("channel_new: internal error: channels_alloc %d "
286: "too big.", channels_alloc);
1.243 djm 287: channels = xrealloc(channels, channels_alloc + 10,
288: sizeof(Channel *));
1.195 markus 289: channels_alloc += 10;
1.70 markus 290: debug2("channel: expanding %d", channels_alloc);
1.25 markus 291: for (i = found; i < channels_alloc; i++)
1.113 markus 292: channels[i] = NULL;
1.25 markus 293: }
1.113 markus 294: /* Initialize and return new channel. */
1.242 djm 295: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 296: buffer_init(&c->input);
297: buffer_init(&c->output);
1.41 markus 298: buffer_init(&c->extended);
1.293 djm 299: c->path = NULL;
1.159 markus 300: c->ostate = CHAN_OUTPUT_OPEN;
301: c->istate = CHAN_INPUT_OPEN;
302: c->flags = 0;
1.281 djm 303: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.25 markus 304: c->self = found;
305: c->type = type;
1.41 markus 306: c->ctype = ctype;
1.51 markus 307: c->local_window = window;
308: c->local_window_max = window;
309: c->local_consumed = 0;
310: c->local_maxpacket = maxpack;
1.25 markus 311: c->remote_id = -1;
1.190 markus 312: c->remote_name = xstrdup(remote_name);
1.41 markus 313: c->remote_window = 0;
314: c->remote_maxpacket = 0;
1.133 markus 315: c->force_drain = 0;
1.149 markus 316: c->single_connection = 0;
1.131 markus 317: c->detach_user = NULL;
1.225 djm 318: c->detach_close = 0;
1.275 djm 319: c->open_confirm = NULL;
320: c->open_confirm_ctx = NULL;
1.65 markus 321: c->input_filter = NULL;
1.231 reyk 322: c->output_filter = NULL;
1.280 djm 323: c->filter_ctx = NULL;
324: c->filter_cleanup = NULL;
1.302 djm 325: c->ctl_chan = -1;
326: c->mux_rcb = NULL;
327: c->mux_ctx = NULL;
1.304 djm 328: c->mux_pause = 0;
1.299 markus 329: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 330: TAILQ_INIT(&c->status_confirms);
1.25 markus 331: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 332: return c;
1.1 deraadt 333: }
1.52 markus 334:
1.132 markus 335: static int
336: channel_find_maxfd(void)
337: {
1.209 avsm 338: u_int i;
339: int max = 0;
1.132 markus 340: Channel *c;
341:
342: for (i = 0; i < channels_alloc; i++) {
343: c = channels[i];
344: if (c != NULL) {
345: max = MAX(max, c->rfd);
346: max = MAX(max, c->wfd);
347: max = MAX(max, c->efd);
348: }
349: }
350: return max;
351: }
352:
353: int
354: channel_close_fd(int *fdp)
355: {
356: int ret = 0, fd = *fdp;
357:
358: if (fd != -1) {
359: ret = close(fd);
360: *fdp = -1;
361: if (fd == channel_max_fd)
362: channel_max_fd = channel_find_maxfd();
363: }
364: return ret;
365: }
366:
1.52 markus 367: /* Close all channel fd/socket. */
1.127 itojun 368: static void
1.52 markus 369: channel_close_fds(Channel *c)
370: {
1.132 markus 371: channel_close_fd(&c->sock);
372: channel_close_fd(&c->rfd);
373: channel_close_fd(&c->wfd);
374: channel_close_fd(&c->efd);
1.121 markus 375: }
376:
377: /* Free the channel and close its fd/socket. */
378: void
379: channel_free(Channel *c)
380: {
381: char *s;
1.209 avsm 382: u_int i, n;
1.275 djm 383: struct channel_confirm *cc;
1.121 markus 384:
385: for (n = 0, i = 0; i < channels_alloc; i++)
386: if (channels[i])
387: n++;
1.209 avsm 388: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 389: c->remote_name ? c->remote_name : "???", n);
390:
391: s = channel_open_message();
1.194 markus 392: debug3("channel %d: status: %s", c->self, s);
1.121 markus 393: xfree(s);
394:
395: if (c->sock != -1)
396: shutdown(c->sock, SHUT_RDWR);
397: channel_close_fds(c);
398: buffer_free(&c->input);
399: buffer_free(&c->output);
400: buffer_free(&c->extended);
401: if (c->remote_name) {
402: xfree(c->remote_name);
403: c->remote_name = NULL;
404: }
1.293 djm 405: if (c->path) {
406: xfree(c->path);
407: c->path = NULL;
408: }
1.275 djm 409: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
410: if (cc->abandon_cb != NULL)
411: cc->abandon_cb(c, cc->ctx);
412: TAILQ_REMOVE(&c->status_confirms, cc, entry);
413: bzero(cc, sizeof(*cc));
414: xfree(cc);
415: }
1.280 djm 416: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
417: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 418: channels[c->self] = NULL;
419: xfree(c);
420: }
421:
422: void
1.126 markus 423: channel_free_all(void)
1.121 markus 424: {
1.209 avsm 425: u_int i;
1.121 markus 426:
1.126 markus 427: for (i = 0; i < channels_alloc; i++)
428: if (channels[i] != NULL)
429: channel_free(channels[i]);
1.131 markus 430: }
431:
1.121 markus 432: /*
433: * Closes the sockets/fds of all channels. This is used to close extra file
434: * descriptors after a fork.
435: */
436: void
1.142 itojun 437: channel_close_all(void)
1.121 markus 438: {
1.209 avsm 439: u_int i;
1.121 markus 440:
441: for (i = 0; i < channels_alloc; i++)
442: if (channels[i] != NULL)
443: channel_close_fds(channels[i]);
444: }
445:
446: /*
1.131 markus 447: * Stop listening to channels.
448: */
449: void
450: channel_stop_listening(void)
451: {
1.209 avsm 452: u_int i;
1.131 markus 453: Channel *c;
454:
455: for (i = 0; i < channels_alloc; i++) {
456: c = channels[i];
457: if (c != NULL) {
458: switch (c->type) {
459: case SSH_CHANNEL_AUTH_SOCKET:
460: case SSH_CHANNEL_PORT_LISTENER:
461: case SSH_CHANNEL_RPORT_LISTENER:
462: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 463: channel_close_fd(&c->sock);
1.131 markus 464: channel_free(c);
465: break;
466: }
467: }
468: }
469: }
470:
471: /*
1.121 markus 472: * Returns true if no channel has too much buffered data, and false if one or
473: * more channel is overfull.
474: */
475: int
1.142 itojun 476: channel_not_very_much_buffered_data(void)
1.121 markus 477: {
478: u_int i;
479: Channel *c;
480:
481: for (i = 0; i < channels_alloc; i++) {
482: c = channels[i];
483: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 484: #if 0
485: if (!compat20 &&
486: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 487: debug2("channel %d: big input buffer %d",
1.121 markus 488: c->self, buffer_len(&c->input));
489: return 0;
490: }
1.136 markus 491: #endif
1.121 markus 492: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 493: debug2("channel %d: big output buffer %u > %u",
1.136 markus 494: c->self, buffer_len(&c->output),
495: packet_get_maxsize());
1.121 markus 496: return 0;
497: }
498: }
499: }
500: return 1;
501: }
502:
503: /* Returns true if any channel is still open. */
504: int
1.142 itojun 505: channel_still_open(void)
1.121 markus 506: {
1.209 avsm 507: u_int i;
1.121 markus 508: Channel *c;
509:
510: for (i = 0; i < channels_alloc; i++) {
511: c = channels[i];
512: if (c == NULL)
513: continue;
514: switch (c->type) {
515: case SSH_CHANNEL_X11_LISTENER:
516: case SSH_CHANNEL_PORT_LISTENER:
517: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 518: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 519: case SSH_CHANNEL_CLOSED:
520: case SSH_CHANNEL_AUTH_SOCKET:
521: case SSH_CHANNEL_DYNAMIC:
522: case SSH_CHANNEL_CONNECTING:
523: case SSH_CHANNEL_ZOMBIE:
524: continue;
525: case SSH_CHANNEL_LARVAL:
526: if (!compat20)
527: fatal("cannot happen: SSH_CHANNEL_LARVAL");
528: continue;
529: case SSH_CHANNEL_OPENING:
530: case SSH_CHANNEL_OPEN:
531: case SSH_CHANNEL_X11_OPEN:
1.302 djm 532: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 533: return 1;
534: case SSH_CHANNEL_INPUT_DRAINING:
535: case SSH_CHANNEL_OUTPUT_DRAINING:
536: if (!compat13)
537: fatal("cannot happen: OUT_DRAIN");
538: return 1;
539: default:
540: fatal("channel_still_open: bad channel type %d", c->type);
541: /* NOTREACHED */
542: }
543: }
544: return 0;
545: }
546:
547: /* Returns the id of an open channel suitable for keepaliving */
548: int
1.142 itojun 549: channel_find_open(void)
1.121 markus 550: {
1.209 avsm 551: u_int i;
1.121 markus 552: Channel *c;
553:
554: for (i = 0; i < channels_alloc; i++) {
555: c = channels[i];
1.206 djm 556: if (c == NULL || c->remote_id < 0)
1.121 markus 557: continue;
558: switch (c->type) {
559: case SSH_CHANNEL_CLOSED:
560: case SSH_CHANNEL_DYNAMIC:
561: case SSH_CHANNEL_X11_LISTENER:
562: case SSH_CHANNEL_PORT_LISTENER:
563: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 564: case SSH_CHANNEL_MUX_LISTENER:
565: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 566: case SSH_CHANNEL_OPENING:
567: case SSH_CHANNEL_CONNECTING:
568: case SSH_CHANNEL_ZOMBIE:
569: continue;
570: case SSH_CHANNEL_LARVAL:
571: case SSH_CHANNEL_AUTH_SOCKET:
572: case SSH_CHANNEL_OPEN:
573: case SSH_CHANNEL_X11_OPEN:
574: return i;
575: case SSH_CHANNEL_INPUT_DRAINING:
576: case SSH_CHANNEL_OUTPUT_DRAINING:
577: if (!compat13)
578: fatal("cannot happen: OUT_DRAIN");
579: return i;
580: default:
581: fatal("channel_find_open: bad channel type %d", c->type);
582: /* NOTREACHED */
583: }
584: }
585: return -1;
586: }
587:
588:
589: /*
590: * Returns a message describing the currently open forwarded connections,
591: * suitable for sending to the client. The message contains crlf pairs for
592: * newlines.
593: */
594: char *
1.142 itojun 595: channel_open_message(void)
1.121 markus 596: {
597: Buffer buffer;
598: Channel *c;
599: char buf[1024], *cp;
1.209 avsm 600: u_int i;
1.121 markus 601:
602: buffer_init(&buffer);
603: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
604: buffer_append(&buffer, buf, strlen(buf));
605: for (i = 0; i < channels_alloc; i++) {
606: c = channels[i];
607: if (c == NULL)
608: continue;
609: switch (c->type) {
610: case SSH_CHANNEL_X11_LISTENER:
611: case SSH_CHANNEL_PORT_LISTENER:
612: case SSH_CHANNEL_RPORT_LISTENER:
613: case SSH_CHANNEL_CLOSED:
614: case SSH_CHANNEL_AUTH_SOCKET:
615: case SSH_CHANNEL_ZOMBIE:
1.302 djm 616: case SSH_CHANNEL_MUX_CLIENT:
617: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 618: continue;
619: case SSH_CHANNEL_LARVAL:
620: case SSH_CHANNEL_OPENING:
621: case SSH_CHANNEL_CONNECTING:
622: case SSH_CHANNEL_DYNAMIC:
623: case SSH_CHANNEL_OPEN:
624: case SSH_CHANNEL_X11_OPEN:
625: case SSH_CHANNEL_INPUT_DRAINING:
626: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 627: snprintf(buf, sizeof buf,
1.302 djm 628: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
1.121 markus 629: c->self, c->remote_name,
630: c->type, c->remote_id,
631: c->istate, buffer_len(&c->input),
632: c->ostate, buffer_len(&c->output),
1.302 djm 633: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 634: buffer_append(&buffer, buf, strlen(buf));
635: continue;
636: default:
637: fatal("channel_open_message: bad channel type %d", c->type);
638: /* NOTREACHED */
639: }
640: }
641: buffer_append(&buffer, "\0", 1);
642: cp = xstrdup(buffer_ptr(&buffer));
643: buffer_free(&buffer);
644: return cp;
645: }
646:
647: void
648: channel_send_open(int id)
649: {
650: Channel *c = channel_lookup(id);
1.180 deraadt 651:
1.121 markus 652: if (c == NULL) {
1.188 itojun 653: logit("channel_send_open: %d: bad id", id);
1.121 markus 654: return;
655: }
1.184 markus 656: debug2("channel %d: send open", id);
1.121 markus 657: packet_start(SSH2_MSG_CHANNEL_OPEN);
658: packet_put_cstring(c->ctype);
659: packet_put_int(c->self);
660: packet_put_int(c->local_window);
661: packet_put_int(c->local_maxpacket);
662: packet_send();
663: }
664:
665: void
1.184 markus 666: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 667: {
1.184 markus 668: Channel *c = channel_lookup(id);
1.180 deraadt 669:
1.121 markus 670: if (c == NULL) {
1.188 itojun 671: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 672: return;
673: }
1.204 djm 674: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 675: packet_start(SSH2_MSG_CHANNEL_REQUEST);
676: packet_put_int(c->remote_id);
677: packet_put_cstring(service);
678: packet_put_char(wantconfirm);
679: }
1.241 deraadt 680:
1.121 markus 681: void
1.275 djm 682: channel_register_status_confirm(int id, channel_confirm_cb *cb,
683: channel_confirm_abandon_cb *abandon_cb, void *ctx)
684: {
685: struct channel_confirm *cc;
686: Channel *c;
687:
688: if ((c = channel_lookup(id)) == NULL)
689: fatal("channel_register_expect: %d: bad id", id);
690:
691: cc = xmalloc(sizeof(*cc));
692: cc->cb = cb;
693: cc->abandon_cb = abandon_cb;
694: cc->ctx = ctx;
695: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
696: }
697:
698: void
1.304 djm 699: channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
1.121 markus 700: {
701: Channel *c = channel_lookup(id);
1.180 deraadt 702:
1.121 markus 703: if (c == NULL) {
1.287 stevesk 704: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 705: return;
706: }
1.275 djm 707: c->open_confirm = fn;
708: c->open_confirm_ctx = ctx;
1.121 markus 709: }
1.241 deraadt 710:
1.121 markus 711: void
1.225 djm 712: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 713: {
1.229 markus 714: Channel *c = channel_by_id(id);
1.180 deraadt 715:
1.121 markus 716: if (c == NULL) {
1.188 itojun 717: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 718: return;
719: }
1.131 markus 720: c->detach_user = fn;
1.225 djm 721: c->detach_close = do_close;
1.121 markus 722: }
1.241 deraadt 723:
1.121 markus 724: void
725: channel_cancel_cleanup(int id)
726: {
1.229 markus 727: Channel *c = channel_by_id(id);
1.180 deraadt 728:
1.121 markus 729: if (c == NULL) {
1.188 itojun 730: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 731: return;
1.52 markus 732: }
1.131 markus 733: c->detach_user = NULL;
1.225 djm 734: c->detach_close = 0;
1.121 markus 735: }
1.241 deraadt 736:
1.121 markus 737: void
1.231 reyk 738: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 739: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 740: {
741: Channel *c = channel_lookup(id);
1.180 deraadt 742:
1.121 markus 743: if (c == NULL) {
1.188 itojun 744: logit("channel_register_filter: %d: bad id", id);
1.121 markus 745: return;
1.52 markus 746: }
1.231 reyk 747: c->input_filter = ifn;
748: c->output_filter = ofn;
1.279 djm 749: c->filter_ctx = ctx;
1.280 djm 750: c->filter_cleanup = cfn;
1.52 markus 751: }
752:
1.49 markus 753: void
1.121 markus 754: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 755: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 756: {
1.121 markus 757: Channel *c = channel_lookup(id);
1.180 deraadt 758:
1.121 markus 759: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
760: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 761: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 762: c->type = SSH_CHANNEL_OPEN;
1.168 markus 763: c->local_window = c->local_window_max = window_max;
1.121 markus 764: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
765: packet_put_int(c->remote_id);
766: packet_put_int(c->local_window);
767: packet_send();
1.1 deraadt 768: }
769:
1.27 markus 770: /*
1.41 markus 771: * 'channel_pre*' are called just before select() to add any bits relevant to
772: * channels in the select bitmasks.
773: */
774: /*
775: * 'channel_post*': perform any appropriate operations for channels which
776: * have events pending.
1.27 markus 777: */
1.237 deraadt 778: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 779: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
780: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
781:
1.259 stevesk 782: /* ARGSUSED */
1.127 itojun 783: static void
1.237 deraadt 784: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 785: {
786: FD_SET(c->sock, readset);
787: }
788:
1.259 stevesk 789: /* ARGSUSED */
1.127 itojun 790: static void
1.237 deraadt 791: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 792: {
793: debug3("channel %d: waiting for connection", c->self);
794: FD_SET(c->sock, writeset);
795: }
796:
1.127 itojun 797: static void
1.237 deraadt 798: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 799: {
800: if (buffer_len(&c->input) < packet_get_maxsize())
801: FD_SET(c->sock, readset);
802: if (buffer_len(&c->output) > 0)
803: FD_SET(c->sock, writeset);
804: }
1.1 deraadt 805:
1.127 itojun 806: static void
1.237 deraadt 807: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 808: {
1.157 markus 809: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 810:
1.44 markus 811: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 812: limit > 0 &&
1.250 djm 813: buffer_len(&c->input) < limit &&
814: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 815: FD_SET(c->rfd, readset);
816: if (c->ostate == CHAN_OUTPUT_OPEN ||
817: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
818: if (buffer_len(&c->output) > 0) {
819: FD_SET(c->wfd, writeset);
820: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 821: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 822: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
823: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 824: else
825: chan_obuf_empty(c);
1.44 markus 826: }
827: }
828: /** XXX check close conditions, too */
1.277 markus 829: if (compat20 && c->efd != -1 &&
830: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 831: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
832: buffer_len(&c->extended) > 0)
833: FD_SET(c->efd, writeset);
1.306 djm 834: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
835: (c->extended_usage == CHAN_EXTENDED_READ ||
836: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 837: buffer_len(&c->extended) < c->remote_window)
838: FD_SET(c->efd, readset);
839: }
1.204 djm 840: /* XXX: What about efd? races? */
1.44 markus 841: }
842:
1.259 stevesk 843: /* ARGSUSED */
1.127 itojun 844: static void
1.237 deraadt 845: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 846: {
847: if (buffer_len(&c->input) == 0) {
848: packet_start(SSH_MSG_CHANNEL_CLOSE);
849: packet_put_int(c->remote_id);
850: packet_send();
851: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 852: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 853: }
854: }
855:
1.259 stevesk 856: /* ARGSUSED */
1.127 itojun 857: static void
1.237 deraadt 858: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 859: {
860: if (buffer_len(&c->output) == 0)
1.113 markus 861: chan_mark_dead(c);
1.49 markus 862: else
1.41 markus 863: FD_SET(c->sock, writeset);
864: }
865:
866: /*
867: * This is a special state for X11 authentication spoofing. An opened X11
868: * connection (when authentication spoofing is being done) remains in this
869: * state until the first packet has been completely read. The authentication
870: * data in that packet is then substituted by the real data if it matches the
871: * fake data, and the channel is put into normal mode.
1.51 markus 872: * XXX All this happens at the client side.
1.121 markus 873: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 874: */
1.127 itojun 875: static int
1.121 markus 876: x11_open_helper(Buffer *b)
1.1 deraadt 877: {
1.77 markus 878: u_char *ucp;
879: u_int proto_len, data_len;
1.25 markus 880:
1.41 markus 881: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 882: if (buffer_len(b) < 12)
1.41 markus 883: return 0;
884:
885: /* Parse the lengths of variable-length fields. */
1.155 stevesk 886: ucp = buffer_ptr(b);
1.41 markus 887: if (ucp[0] == 0x42) { /* Byte order MSB first. */
888: proto_len = 256 * ucp[6] + ucp[7];
889: data_len = 256 * ucp[8] + ucp[9];
890: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
891: proto_len = ucp[6] + 256 * ucp[7];
892: data_len = ucp[8] + 256 * ucp[9];
893: } else {
1.194 markus 894: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 895: ucp[0]);
1.41 markus 896: return -1;
897: }
898:
899: /* Check if the whole packet is in buffer. */
1.121 markus 900: if (buffer_len(b) <
1.41 markus 901: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
902: return 0;
903:
904: /* Check if authentication protocol matches. */
905: if (proto_len != strlen(x11_saved_proto) ||
906: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 907: debug2("X11 connection uses different authentication protocol.");
1.41 markus 908: return -1;
909: }
910: /* Check if authentication data matches our fake data. */
911: if (data_len != x11_fake_data_len ||
1.308 djm 912: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.41 markus 913: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 914: debug2("X11 auth data does not match fake data.");
1.41 markus 915: return -1;
916: }
917: /* Check fake data length */
918: if (x11_fake_data_len != x11_saved_data_len) {
919: error("X11 fake_data_len %d != saved_data_len %d",
920: x11_fake_data_len, x11_saved_data_len);
921: return -1;
922: }
923: /*
924: * Received authentication protocol and data match
925: * our fake data. Substitute the fake data with real
926: * data.
927: */
928: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
929: x11_saved_data, x11_saved_data_len);
930: return 1;
931: }
932:
1.127 itojun 933: static void
1.237 deraadt 934: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 935: {
1.121 markus 936: int ret = x11_open_helper(&c->output);
1.180 deraadt 937:
1.41 markus 938: if (ret == 1) {
939: /* Start normal processing for the channel. */
940: c->type = SSH_CHANNEL_OPEN;
1.47 markus 941: channel_pre_open_13(c, readset, writeset);
1.41 markus 942: } else if (ret == -1) {
943: /*
944: * We have received an X11 connection that has bad
945: * authentication information.
946: */
1.188 itojun 947: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 948: buffer_clear(&c->input);
949: buffer_clear(&c->output);
1.132 markus 950: channel_close_fd(&c->sock);
1.41 markus 951: c->sock = -1;
952: c->type = SSH_CHANNEL_CLOSED;
953: packet_start(SSH_MSG_CHANNEL_CLOSE);
954: packet_put_int(c->remote_id);
955: packet_send();
956: }
957: }
1.25 markus 958:
1.127 itojun 959: static void
1.237 deraadt 960: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 961: {
1.121 markus 962: int ret = x11_open_helper(&c->output);
1.133 markus 963:
964: /* c->force_drain = 1; */
965:
1.41 markus 966: if (ret == 1) {
967: c->type = SSH_CHANNEL_OPEN;
1.157 markus 968: channel_pre_open(c, readset, writeset);
1.41 markus 969: } else if (ret == -1) {
1.188 itojun 970: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 971: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 972: chan_read_failed(c);
973: buffer_clear(&c->input);
974: chan_ibuf_empty(c);
975: buffer_clear(&c->output);
976: /* for proto v1, the peer will send an IEOF */
977: if (compat20)
978: chan_write_failed(c);
979: else
980: c->type = SSH_CHANNEL_OPEN;
1.194 markus 981: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 982: }
983: }
1.25 markus 984:
1.302 djm 985: static void
986: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
987: {
1.304 djm 988: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 989: buffer_check_alloc(&c->input, CHAN_RBUF))
990: FD_SET(c->rfd, readset);
991: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
992: /* clear buffer immediately (discard any partial packet) */
993: buffer_clear(&c->input);
994: chan_ibuf_empty(c);
995: /* Start output drain. XXX just kill chan? */
996: chan_rcvd_oclose(c);
997: }
998: if (c->ostate == CHAN_OUTPUT_OPEN ||
999: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1000: if (buffer_len(&c->output) > 0)
1001: FD_SET(c->wfd, writeset);
1002: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1003: chan_obuf_empty(c);
1004: }
1005: }
1006:
1.104 markus 1007: /* try to decode a socks4 header */
1.259 stevesk 1008: /* ARGSUSED */
1.127 itojun 1009: static int
1.237 deraadt 1010: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1011: {
1.181 markus 1012: char *p, *host;
1.292 djm 1013: u_int len, have, i, found, need;
1.148 deraadt 1014: char username[256];
1.103 markus 1015: struct {
1016: u_int8_t version;
1017: u_int8_t command;
1018: u_int16_t dest_port;
1.104 markus 1019: struct in_addr dest_addr;
1.103 markus 1020: } s4_req, s4_rsp;
1021:
1.104 markus 1022: debug2("channel %d: decode socks4", c->self);
1.109 markus 1023:
1024: have = buffer_len(&c->input);
1025: len = sizeof(s4_req);
1026: if (have < len)
1027: return 0;
1028: p = buffer_ptr(&c->input);
1.292 djm 1029:
1030: need = 1;
1031: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1032: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1033: debug2("channel %d: socks4a request", c->self);
1034: /* ... and needs an extra string (the hostname) */
1035: need = 2;
1036: }
1037: /* Check for terminating NUL on the string(s) */
1.109 markus 1038: for (found = 0, i = len; i < have; i++) {
1039: if (p[i] == '\0') {
1.292 djm 1040: found++;
1041: if (found == need)
1042: break;
1.109 markus 1043: }
1044: if (i > 1024) {
1045: /* the peer is probably sending garbage */
1046: debug("channel %d: decode socks4: too long",
1047: c->self);
1048: return -1;
1049: }
1050: }
1.292 djm 1051: if (found < need)
1.109 markus 1052: return 0;
1.103 markus 1053: buffer_get(&c->input, (char *)&s4_req.version, 1);
1054: buffer_get(&c->input, (char *)&s4_req.command, 1);
1055: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1056: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1057: have = buffer_len(&c->input);
1.103 markus 1058: p = buffer_ptr(&c->input);
1059: len = strlen(p);
1.106 markus 1060: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1061: len++; /* trailing '\0' */
1.103 markus 1062: if (len > have)
1.104 markus 1063: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1064: c->self, len, have);
1065: strlcpy(username, p, sizeof(username));
1066: buffer_consume(&c->input, len);
1067:
1.293 djm 1068: if (c->path != NULL) {
1069: xfree(c->path);
1070: c->path = NULL;
1071: }
1.292 djm 1072: if (need == 1) { /* SOCKS4: one string */
1073: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1074: c->path = xstrdup(host);
1.292 djm 1075: } else { /* SOCKS4A: two strings */
1076: have = buffer_len(&c->input);
1077: p = buffer_ptr(&c->input);
1078: len = strlen(p);
1079: debug2("channel %d: decode socks4a: host %s/%d",
1080: c->self, p, len);
1081: len++; /* trailing '\0' */
1082: if (len > have)
1083: fatal("channel %d: decode socks4a: len %d > have %d",
1084: c->self, len, have);
1.293 djm 1085: if (len > NI_MAXHOST) {
1.292 djm 1086: error("channel %d: hostname \"%.100s\" too long",
1087: c->self, p);
1088: return -1;
1089: }
1.293 djm 1090: c->path = xstrdup(p);
1.292 djm 1091: buffer_consume(&c->input, len);
1092: }
1.103 markus 1093: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1094:
1.194 markus 1095: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1096: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1097:
1.104 markus 1098: if (s4_req.command != 1) {
1.292 djm 1099: debug("channel %d: cannot handle: %s cn %d",
1100: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1101: return -1;
1.103 markus 1102: }
1.104 markus 1103: s4_rsp.version = 0; /* vn: 0 for reply */
1104: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1105: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1106: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1107: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1108: return 1;
1109: }
1110:
1.193 markus 1111: /* try to decode a socks5 header */
1112: #define SSH_SOCKS5_AUTHDONE 0x1000
1113: #define SSH_SOCKS5_NOAUTH 0x00
1114: #define SSH_SOCKS5_IPV4 0x01
1115: #define SSH_SOCKS5_DOMAIN 0x03
1116: #define SSH_SOCKS5_IPV6 0x04
1117: #define SSH_SOCKS5_CONNECT 0x01
1118: #define SSH_SOCKS5_SUCCESS 0x00
1119:
1.259 stevesk 1120: /* ARGSUSED */
1.193 markus 1121: static int
1.237 deraadt 1122: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1123: {
1124: struct {
1125: u_int8_t version;
1126: u_int8_t command;
1127: u_int8_t reserved;
1128: u_int8_t atyp;
1129: } s5_req, s5_rsp;
1130: u_int16_t dest_port;
1.293 djm 1131: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1132: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1133:
1134: debug2("channel %d: decode socks5", c->self);
1135: p = buffer_ptr(&c->input);
1136: if (p[0] != 0x05)
1137: return -1;
1138: have = buffer_len(&c->input);
1139: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1140: /* format: ver | nmethods | methods */
1.198 djm 1141: if (have < 2)
1.193 markus 1142: return 0;
1143: nmethods = p[1];
1144: if (have < nmethods + 2)
1145: return 0;
1146: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1147: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1148: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1149: found = 1;
1150: break;
1151: }
1152: }
1153: if (!found) {
1154: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1155: c->self);
1156: return -1;
1157: }
1158: buffer_consume(&c->input, nmethods + 2);
1159: buffer_put_char(&c->output, 0x05); /* version */
1160: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1161: FD_SET(c->sock, writeset);
1162: c->flags |= SSH_SOCKS5_AUTHDONE;
1163: debug2("channel %d: socks5 auth done", c->self);
1164: return 0; /* need more */
1165: }
1166: debug2("channel %d: socks5 post auth", c->self);
1167: if (have < sizeof(s5_req)+1)
1168: return 0; /* need more */
1.247 deraadt 1169: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1170: if (s5_req.version != 0x05 ||
1171: s5_req.command != SSH_SOCKS5_CONNECT ||
1172: s5_req.reserved != 0x00) {
1.194 markus 1173: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1174: return -1;
1175: }
1.213 deraadt 1176: switch (s5_req.atyp){
1.193 markus 1177: case SSH_SOCKS5_IPV4:
1178: addrlen = 4;
1179: af = AF_INET;
1180: break;
1181: case SSH_SOCKS5_DOMAIN:
1182: addrlen = p[sizeof(s5_req)];
1183: af = -1;
1184: break;
1185: case SSH_SOCKS5_IPV6:
1186: addrlen = 16;
1187: af = AF_INET6;
1188: break;
1189: default:
1.194 markus 1190: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1191: return -1;
1192: }
1.252 djm 1193: need = sizeof(s5_req) + addrlen + 2;
1194: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1195: need++;
1196: if (have < need)
1.193 markus 1197: return 0;
1198: buffer_consume(&c->input, sizeof(s5_req));
1199: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1200: buffer_consume(&c->input, 1); /* host string length */
1201: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1202: buffer_get(&c->input, (char *)&dest_port, 2);
1203: dest_addr[addrlen] = '\0';
1.293 djm 1204: if (c->path != NULL) {
1205: xfree(c->path);
1206: c->path = NULL;
1207: }
1208: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1209: if (addrlen >= NI_MAXHOST) {
1.293 djm 1210: error("channel %d: dynamic request: socks5 hostname "
1211: "\"%.100s\" too long", c->self, dest_addr);
1212: return -1;
1213: }
1214: c->path = xstrdup(dest_addr);
1215: } else {
1216: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1217: return -1;
1218: c->path = xstrdup(ntop);
1219: }
1.193 markus 1220: c->host_port = ntohs(dest_port);
1.198 djm 1221:
1.194 markus 1222: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1223: c->self, c->path, c->host_port, s5_req.command);
1224:
1225: s5_rsp.version = 0x05;
1226: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1227: s5_rsp.reserved = 0; /* ignored */
1228: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1229: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1230: dest_port = 0; /* ignored */
1231:
1.246 deraadt 1232: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1233: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1234: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1235: return 1;
1.301 dtucker 1236: }
1237:
1238: Channel *
1.302 djm 1239: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1240: int in, int out)
1.301 dtucker 1241: {
1242: Channel *c;
1243:
1244: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1245: port_to_connect);
1246:
1247: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1248: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1249: 0, "stdio-forward", /*nonblock*/0);
1250:
1251: c->path = xstrdup(host_to_connect);
1252: c->host_port = port_to_connect;
1253: c->listening_port = 0;
1254: c->force_drain = 1;
1255:
1256: channel_register_fds(c, in, out, -1, 0, 1, 0);
1257: port_open_helper(c, "direct-tcpip");
1258:
1259: return c;
1.193 markus 1260: }
1261:
1.104 markus 1262: /* dynamic port forwarding */
1.127 itojun 1263: static void
1.237 deraadt 1264: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1265: {
1266: u_char *p;
1.217 djm 1267: u_int have;
1268: int ret;
1.103 markus 1269:
1.104 markus 1270: have = buffer_len(&c->input);
1271: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1272: /* buffer_dump(&c->input); */
1.104 markus 1273: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1274: if (have < 3) {
1.104 markus 1275: /* need more */
1276: FD_SET(c->sock, readset);
1277: return;
1278: }
1279: /* try to guess the protocol */
1280: p = buffer_ptr(&c->input);
1281: switch (p[0]) {
1282: case 0x04:
1283: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1284: break;
1285: case 0x05:
1286: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1287: break;
1288: default:
1289: ret = -1;
1290: break;
1291: }
1292: if (ret < 0) {
1.113 markus 1293: chan_mark_dead(c);
1.104 markus 1294: } else if (ret == 0) {
1295: debug2("channel %d: pre_dynamic: need more", c->self);
1296: /* need more */
1297: FD_SET(c->sock, readset);
1298: } else {
1299: /* switch to the next state */
1300: c->type = SSH_CHANNEL_OPENING;
1301: port_open_helper(c, "direct-tcpip");
1302: }
1.103 markus 1303: }
1304:
1.41 markus 1305: /* This is our fake X11 server socket. */
1.259 stevesk 1306: /* ARGSUSED */
1.127 itojun 1307: static void
1.237 deraadt 1308: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1309: {
1.113 markus 1310: Channel *nc;
1.285 djm 1311: struct sockaddr_storage addr;
1.162 stevesk 1312: int newsock;
1.41 markus 1313: socklen_t addrlen;
1.85 markus 1314: char buf[16384], *remote_ipaddr;
1.51 markus 1315: int remote_port;
1.25 markus 1316:
1.41 markus 1317: if (FD_ISSET(c->sock, readset)) {
1318: debug("X11 connection requested.");
1319: addrlen = sizeof(addr);
1.285 djm 1320: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1321: if (c->single_connection) {
1.194 markus 1322: debug2("single_connection: closing X11 listener.");
1.149 markus 1323: channel_close_fd(&c->sock);
1324: chan_mark_dead(c);
1325: }
1.41 markus 1326: if (newsock < 0) {
1327: error("accept: %.100s", strerror(errno));
1328: return;
1329: }
1.162 stevesk 1330: set_nodelay(newsock);
1.85 markus 1331: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1332: remote_port = get_peer_port(newsock);
1.41 markus 1333: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1334: remote_ipaddr, remote_port);
1.51 markus 1335:
1.113 markus 1336: nc = channel_new("accepted x11 socket",
1.51 markus 1337: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1338: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1339: if (compat20) {
1340: packet_start(SSH2_MSG_CHANNEL_OPEN);
1341: packet_put_cstring("x11");
1.113 markus 1342: packet_put_int(nc->self);
1.149 markus 1343: packet_put_int(nc->local_window_max);
1344: packet_put_int(nc->local_maxpacket);
1.85 markus 1345: /* originator ipaddr and port */
1346: packet_put_cstring(remote_ipaddr);
1.57 markus 1347: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1348: debug2("ssh2 x11 bug compat mode");
1.57 markus 1349: } else {
1350: packet_put_int(remote_port);
1351: }
1.51 markus 1352: packet_send();
1353: } else {
1354: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1355: packet_put_int(nc->self);
1.121 markus 1356: if (packet_get_protocol_flags() &
1357: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1358: packet_put_cstring(buf);
1.51 markus 1359: packet_send();
1360: }
1.85 markus 1361: xfree(remote_ipaddr);
1.41 markus 1362: }
1363: }
1.25 markus 1364:
1.127 itojun 1365: static void
1.103 markus 1366: port_open_helper(Channel *c, char *rtype)
1367: {
1368: int direct;
1369: char buf[1024];
1370: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1371: int remote_port = get_peer_port(c->sock);
1.303 djm 1372:
1373: if (remote_port == -1) {
1374: /* Fake addr/port to appease peers that validate it (Tectia) */
1375: xfree(remote_ipaddr);
1376: remote_ipaddr = xstrdup("127.0.0.1");
1377: remote_port = 65535;
1378: }
1.103 markus 1379:
1380: direct = (strcmp(rtype, "direct-tcpip") == 0);
1381:
1382: snprintf(buf, sizeof buf,
1383: "%s: listening port %d for %.100s port %d, "
1384: "connect from %.200s port %d",
1385: rtype, c->listening_port, c->path, c->host_port,
1386: remote_ipaddr, remote_port);
1387:
1388: xfree(c->remote_name);
1389: c->remote_name = xstrdup(buf);
1390:
1391: if (compat20) {
1392: packet_start(SSH2_MSG_CHANNEL_OPEN);
1393: packet_put_cstring(rtype);
1394: packet_put_int(c->self);
1395: packet_put_int(c->local_window_max);
1396: packet_put_int(c->local_maxpacket);
1397: if (direct) {
1398: /* target host, port */
1399: packet_put_cstring(c->path);
1400: packet_put_int(c->host_port);
1401: } else {
1402: /* listen address, port */
1403: packet_put_cstring(c->path);
1404: packet_put_int(c->listening_port);
1405: }
1406: /* originator host and port */
1407: packet_put_cstring(remote_ipaddr);
1.216 markus 1408: packet_put_int((u_int)remote_port);
1.103 markus 1409: packet_send();
1410: } else {
1411: packet_start(SSH_MSG_PORT_OPEN);
1412: packet_put_int(c->self);
1413: packet_put_cstring(c->path);
1414: packet_put_int(c->host_port);
1.121 markus 1415: if (packet_get_protocol_flags() &
1416: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1417: packet_put_cstring(c->remote_name);
1418: packet_send();
1419: }
1420: xfree(remote_ipaddr);
1421: }
1422:
1.226 djm 1423: static void
1424: channel_set_reuseaddr(int fd)
1425: {
1426: int on = 1;
1427:
1428: /*
1429: * Set socket options.
1430: * Allow local port reuse in TIME_WAIT.
1431: */
1432: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1433: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1434: }
1435:
1.41 markus 1436: /*
1437: * This socket is listening for connections to a forwarded TCP/IP port.
1438: */
1.259 stevesk 1439: /* ARGSUSED */
1.127 itojun 1440: static void
1.237 deraadt 1441: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1442: {
1.103 markus 1443: Channel *nc;
1.285 djm 1444: struct sockaddr_storage addr;
1.113 markus 1445: int newsock, nextstate;
1.41 markus 1446: socklen_t addrlen;
1.103 markus 1447: char *rtype;
1.73 markus 1448:
1.41 markus 1449: if (FD_ISSET(c->sock, readset)) {
1450: debug("Connection to port %d forwarding "
1451: "to %.100s port %d requested.",
1452: c->listening_port, c->path, c->host_port);
1.103 markus 1453:
1.137 markus 1454: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1455: nextstate = SSH_CHANNEL_OPENING;
1456: rtype = "forwarded-tcpip";
1457: } else {
1458: if (c->host_port == 0) {
1459: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1460: rtype = "dynamic-tcpip";
1.137 markus 1461: } else {
1462: nextstate = SSH_CHANNEL_OPENING;
1463: rtype = "direct-tcpip";
1464: }
1465: }
1.103 markus 1466:
1.41 markus 1467: addrlen = sizeof(addr);
1.285 djm 1468: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1469: if (newsock < 0) {
1470: error("accept: %.100s", strerror(errno));
1471: return;
1472: }
1.169 stevesk 1473: set_nodelay(newsock);
1.190 markus 1474: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1475: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1476: nc->listening_port = c->listening_port;
1477: nc->host_port = c->host_port;
1.293 djm 1478: if (c->path != NULL)
1479: nc->path = xstrdup(c->path);
1.103 markus 1480:
1.299 markus 1481: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1482: port_open_helper(nc, rtype);
1.41 markus 1483: }
1484: }
1.25 markus 1485:
1.41 markus 1486: /*
1487: * This is the authentication agent socket listening for connections from
1488: * clients.
1489: */
1.259 stevesk 1490: /* ARGSUSED */
1.127 itojun 1491: static void
1.237 deraadt 1492: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1493: {
1.113 markus 1494: Channel *nc;
1495: int newsock;
1.285 djm 1496: struct sockaddr_storage addr;
1.41 markus 1497: socklen_t addrlen;
1.25 markus 1498:
1.41 markus 1499: if (FD_ISSET(c->sock, readset)) {
1500: addrlen = sizeof(addr);
1.285 djm 1501: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1502: if (newsock < 0) {
1503: error("accept from auth socket: %.100s", strerror(errno));
1504: return;
1505: }
1.113 markus 1506: nc = channel_new("accepted auth socket",
1.73 markus 1507: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1508: c->local_window_max, c->local_maxpacket,
1.190 markus 1509: 0, "accepted auth socket", 1);
1.73 markus 1510: if (compat20) {
1511: packet_start(SSH2_MSG_CHANNEL_OPEN);
1512: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1513: packet_put_int(nc->self);
1.73 markus 1514: packet_put_int(c->local_window_max);
1515: packet_put_int(c->local_maxpacket);
1516: } else {
1517: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1518: packet_put_int(nc->self);
1.73 markus 1519: }
1.41 markus 1520: packet_send();
1521: }
1522: }
1.25 markus 1523:
1.259 stevesk 1524: /* ARGSUSED */
1.127 itojun 1525: static void
1.237 deraadt 1526: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1527: {
1.276 djm 1528: int err = 0, sock;
1.129 stevesk 1529: socklen_t sz = sizeof(err);
1.114 markus 1530:
1.75 markus 1531: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1532: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1533: err = errno;
1534: error("getsockopt SO_ERROR failed");
1535: }
1536: if (err == 0) {
1.276 djm 1537: debug("channel %d: connected to %s port %d",
1538: c->self, c->connect_ctx.host, c->connect_ctx.port);
1539: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1540: c->type = SSH_CHANNEL_OPEN;
1541: if (compat20) {
1542: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1543: packet_put_int(c->remote_id);
1544: packet_put_int(c->self);
1545: packet_put_int(c->local_window);
1546: packet_put_int(c->local_maxpacket);
1547: } else {
1548: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1549: packet_put_int(c->remote_id);
1550: packet_put_int(c->self);
1551: }
1.75 markus 1552: } else {
1.276 djm 1553: debug("channel %d: connection failed: %s",
1.114 markus 1554: c->self, strerror(err));
1.276 djm 1555: /* Try next address, if any */
1556: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1557: close(c->sock);
1558: c->sock = c->rfd = c->wfd = sock;
1559: channel_max_fd = channel_find_maxfd();
1560: return;
1561: }
1562: /* Exhausted all addresses */
1563: error("connect_to %.100s port %d: failed.",
1564: c->connect_ctx.host, c->connect_ctx.port);
1565: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1566: if (compat20) {
1567: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1568: packet_put_int(c->remote_id);
1569: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1570: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1571: packet_put_cstring(strerror(err));
1572: packet_put_cstring("");
1573: }
1.75 markus 1574: } else {
1.114 markus 1575: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1576: packet_put_int(c->remote_id);
1.75 markus 1577: }
1.114 markus 1578: chan_mark_dead(c);
1.75 markus 1579: }
1.114 markus 1580: packet_send();
1.75 markus 1581: }
1582: }
1583:
1.259 stevesk 1584: /* ARGSUSED */
1.127 itojun 1585: static int
1.237 deraadt 1586: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1587: {
1.214 markus 1588: char buf[CHAN_RBUF];
1.41 markus 1589: int len;
1.25 markus 1590:
1.118 markus 1591: if (c->rfd != -1 &&
1.41 markus 1592: FD_ISSET(c->rfd, readset)) {
1593: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1594: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1595: return 1;
1.41 markus 1596: if (len <= 0) {
1.194 markus 1597: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1598: c->self, c->rfd, len);
1.104 markus 1599: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1600: debug2("channel %d: not open", c->self);
1.113 markus 1601: chan_mark_dead(c);
1.103 markus 1602: return -1;
1.104 markus 1603: } else if (compat13) {
1.158 markus 1604: buffer_clear(&c->output);
1.41 markus 1605: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1606: debug2("channel %d: input draining.", c->self);
1.25 markus 1607: } else {
1.41 markus 1608: chan_read_failed(c);
1.25 markus 1609: }
1.41 markus 1610: return -1;
1611: }
1.143 deraadt 1612: if (c->input_filter != NULL) {
1.66 markus 1613: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1614: debug2("channel %d: filter stops", c->self);
1.65 markus 1615: chan_read_failed(c);
1616: }
1.228 reyk 1617: } else if (c->datagram) {
1618: buffer_put_string(&c->input, buf, len);
1.65 markus 1619: } else {
1620: buffer_append(&c->input, buf, len);
1621: }
1.41 markus 1622: }
1623: return 1;
1624: }
1.241 deraadt 1625:
1.259 stevesk 1626: /* ARGSUSED */
1.127 itojun 1627: static int
1.237 deraadt 1628: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1629: {
1.95 markus 1630: struct termios tio;
1.231 reyk 1631: u_char *data = NULL, *buf;
1.309 djm 1632: u_int dlen, olen = 0;
1.41 markus 1633: int len;
1.25 markus 1634:
1.41 markus 1635: /* Send buffered output data to the socket. */
1.118 markus 1636: if (c->wfd != -1 &&
1.41 markus 1637: FD_ISSET(c->wfd, writeset) &&
1638: buffer_len(&c->output) > 0) {
1.309 djm 1639: olen = buffer_len(&c->output);
1.231 reyk 1640: if (c->output_filter != NULL) {
1641: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1642: debug2("channel %d: filter stops", c->self);
1.232 reyk 1643: if (c->type != SSH_CHANNEL_OPEN)
1644: chan_mark_dead(c);
1645: else
1646: chan_write_failed(c);
1647: return -1;
1.231 reyk 1648: }
1649: } else if (c->datagram) {
1650: buf = data = buffer_get_string(&c->output, &dlen);
1651: } else {
1652: buf = data = buffer_ptr(&c->output);
1653: dlen = buffer_len(&c->output);
1654: }
1655:
1.228 reyk 1656: if (c->datagram) {
1657: /* ignore truncated writes, datagrams might get lost */
1.231 reyk 1658: len = write(c->wfd, buf, dlen);
1.228 reyk 1659: xfree(data);
1660: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1661: return 1;
1662: if (len <= 0) {
1663: if (c->type != SSH_CHANNEL_OPEN)
1664: chan_mark_dead(c);
1665: else
1666: chan_write_failed(c);
1667: return -1;
1668: }
1.309 djm 1669: goto out;
1.228 reyk 1670: }
1.231 reyk 1671:
1672: len = write(c->wfd, buf, dlen);
1.53 markus 1673: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1674: return 1;
1.41 markus 1675: if (len <= 0) {
1.104 markus 1676: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1677: debug2("channel %d: not open", c->self);
1.113 markus 1678: chan_mark_dead(c);
1.104 markus 1679: return -1;
1680: } else if (compat13) {
1.158 markus 1681: buffer_clear(&c->output);
1.194 markus 1682: debug2("channel %d: input draining.", c->self);
1.41 markus 1683: c->type = SSH_CHANNEL_INPUT_DRAINING;
1684: } else {
1685: chan_write_failed(c);
1686: }
1687: return -1;
1.91 markus 1688: }
1.231 reyk 1689: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1690: if (tcgetattr(c->wfd, &tio) == 0 &&
1691: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1692: /*
1693: * Simulate echo to reduce the impact of
1.96 markus 1694: * traffic analysis. We need to match the
1.95 markus 1695: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1696: * (4 byte channel id + buf)
1.91 markus 1697: */
1.95 markus 1698: packet_send_ignore(4 + len);
1.91 markus 1699: packet_send();
1700: }
1.25 markus 1701: }
1.41 markus 1702: buffer_consume(&c->output, len);
1.44 markus 1703: }
1.309 djm 1704: out:
1705: if (compat20 && olen > 0)
1706: c->local_consumed += olen - buffer_len(&c->output);
1.44 markus 1707: return 1;
1708: }
1.241 deraadt 1709:
1.127 itojun 1710: static int
1.237 deraadt 1711: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1712: {
1.214 markus 1713: char buf[CHAN_RBUF];
1.44 markus 1714: int len;
1715:
1.45 markus 1716: /** XXX handle drain efd, too */
1.44 markus 1717: if (c->efd != -1) {
1718: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1719: FD_ISSET(c->efd, writeset) &&
1720: buffer_len(&c->extended) > 0) {
1721: len = write(c->efd, buffer_ptr(&c->extended),
1722: buffer_len(&c->extended));
1.70 markus 1723: debug2("channel %d: written %d to efd %d",
1.44 markus 1724: c->self, len, c->efd);
1.93 markus 1725: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1726: return 1;
1727: if (len <= 0) {
1728: debug2("channel %d: closing write-efd %d",
1729: c->self, c->efd);
1.132 markus 1730: channel_close_fd(&c->efd);
1.93 markus 1731: } else {
1.44 markus 1732: buffer_consume(&c->extended, len);
1733: c->local_consumed += len;
1734: }
1.306 djm 1735: } else if (c->efd != -1 &&
1736: (c->extended_usage == CHAN_EXTENDED_READ ||
1737: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 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 {
1.306 djm 1749: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1750: debug3("channel %d: discard efd",
1751: c->self);
1752: } else
1753: buffer_append(&c->extended, buf, len);
1.93 markus 1754: }
1.44 markus 1755: }
1756: }
1757: return 1;
1758: }
1.241 deraadt 1759:
1.259 stevesk 1760: /* ARGSUSED */
1.127 itojun 1761: static int
1.93 markus 1762: channel_check_window(Channel *c)
1.44 markus 1763: {
1.104 markus 1764: if (c->type == SSH_CHANNEL_OPEN &&
1765: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1766: ((c->local_window_max - c->local_window >
1.269 markus 1767: c->local_maxpacket*3) ||
1768: c->local_window < c->local_window_max/2) &&
1.44 markus 1769: c->local_consumed > 0) {
1770: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1771: packet_put_int(c->remote_id);
1772: packet_put_int(c->local_consumed);
1773: packet_send();
1.70 markus 1774: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1775: c->self, c->local_window,
1776: c->local_consumed);
1777: c->local_window += c->local_consumed;
1778: c->local_consumed = 0;
1.1 deraadt 1779: }
1.41 markus 1780: return 1;
1.1 deraadt 1781: }
1782:
1.127 itojun 1783: static void
1.237 deraadt 1784: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1785: {
1786: channel_handle_rfd(c, readset, writeset);
1787: channel_handle_wfd(c, readset, writeset);
1.157 markus 1788: if (!compat20)
1.137 markus 1789: return;
1.44 markus 1790: channel_handle_efd(c, readset, writeset);
1.93 markus 1791: channel_check_window(c);
1.44 markus 1792: }
1793:
1.302 djm 1794: static u_int
1795: read_mux(Channel *c, u_int need)
1796: {
1797: char buf[CHAN_RBUF];
1798: int len;
1799: u_int rlen;
1800:
1801: if (buffer_len(&c->input) < need) {
1802: rlen = need - buffer_len(&c->input);
1803: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1804: if (len <= 0) {
1805: if (errno != EINTR && errno != EAGAIN) {
1806: debug2("channel %d: ctl read<=0 rfd %d len %d",
1807: c->self, c->rfd, len);
1808: chan_read_failed(c);
1809: return 0;
1810: }
1811: } else
1812: buffer_append(&c->input, buf, len);
1813: }
1814: return buffer_len(&c->input);
1815: }
1816:
1817: static void
1818: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1819: {
1820: u_int need;
1821: ssize_t len;
1822:
1823: if (!compat20)
1824: fatal("%s: entered with !compat20", __func__);
1825:
1.304 djm 1826: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1827: (c->istate == CHAN_INPUT_OPEN ||
1828: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1829: /*
1830: * Don't not read past the precise end of packets to
1831: * avoid disrupting fd passing.
1832: */
1833: if (read_mux(c, 4) < 4) /* read header */
1834: return;
1835: need = get_u32(buffer_ptr(&c->input));
1836: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1837: if (need > CHANNEL_MUX_MAX_PACKET) {
1838: debug2("channel %d: packet too big %u > %u",
1839: c->self, CHANNEL_MUX_MAX_PACKET, need);
1840: chan_rcvd_oclose(c);
1841: return;
1842: }
1843: if (read_mux(c, need + 4) < need + 4) /* read body */
1844: return;
1845: if (c->mux_rcb(c) != 0) {
1846: debug("channel %d: mux_rcb failed", c->self);
1847: chan_mark_dead(c);
1848: return;
1849: }
1850: }
1851:
1852: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1853: buffer_len(&c->output) > 0) {
1854: len = write(c->wfd, buffer_ptr(&c->output),
1855: buffer_len(&c->output));
1856: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1857: return;
1858: if (len <= 0) {
1859: chan_mark_dead(c);
1860: return;
1861: }
1862: buffer_consume(&c->output, len);
1863: }
1864: }
1865:
1866: static void
1867: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1868: {
1869: Channel *nc;
1870: struct sockaddr_storage addr;
1871: socklen_t addrlen;
1872: int newsock;
1873: uid_t euid;
1874: gid_t egid;
1875:
1876: if (!FD_ISSET(c->sock, readset))
1877: return;
1878:
1879: debug("multiplexing control connection");
1880:
1881: /*
1882: * Accept connection on control socket
1883: */
1884: memset(&addr, 0, sizeof(addr));
1885: addrlen = sizeof(addr);
1886: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1887: &addrlen)) == -1) {
1888: error("%s accept: %s", __func__, strerror(errno));
1889: return;
1890: }
1891:
1892: if (getpeereid(newsock, &euid, &egid) < 0) {
1893: error("%s getpeereid failed: %s", __func__,
1894: strerror(errno));
1895: close(newsock);
1896: return;
1897: }
1898: if ((euid != 0) && (getuid() != euid)) {
1899: error("multiplex uid mismatch: peer euid %u != uid %u",
1900: (u_int)euid, (u_int)getuid());
1901: close(newsock);
1902: return;
1903: }
1904: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1905: newsock, newsock, -1, c->local_window_max,
1906: c->local_maxpacket, 0, "mux-control", 1);
1907: nc->mux_rcb = c->mux_rcb;
1908: debug3("%s: new mux channel %d fd %d", __func__,
1909: nc->self, nc->sock);
1910: /* establish state */
1911: nc->mux_rcb(nc);
1912: /* mux state transitions must not elicit protocol messages */
1913: nc->flags |= CHAN_LOCAL;
1914: }
1915:
1.259 stevesk 1916: /* ARGSUSED */
1.127 itojun 1917: static void
1.237 deraadt 1918: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1919: {
1.41 markus 1920: int len;
1.180 deraadt 1921:
1.41 markus 1922: /* Send buffered output data to the socket. */
1923: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1924: len = write(c->sock, buffer_ptr(&c->output),
1925: buffer_len(&c->output));
1926: if (len <= 0)
1.158 markus 1927: buffer_clear(&c->output);
1.41 markus 1928: else
1929: buffer_consume(&c->output, len);
1930: }
1931: }
1.25 markus 1932:
1.127 itojun 1933: static void
1.44 markus 1934: channel_handler_init_20(void)
1935: {
1.157 markus 1936: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1937: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1938: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1939: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1940: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1941: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1942: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1943: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 1944: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1945: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1946:
1.157 markus 1947: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1948: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1949: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1950: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1951: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1952: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1953: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 1954: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1955: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1956: }
1957:
1.127 itojun 1958: static void
1.41 markus 1959: channel_handler_init_13(void)
1960: {
1961: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1962: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1963: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1964: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1965: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1966: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1967: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1968: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1969: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1970:
1.157 markus 1971: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1972: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1973: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1974: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1975: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1976: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1977: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1978: }
1.25 markus 1979:
1.127 itojun 1980: static void
1.41 markus 1981: channel_handler_init_15(void)
1982: {
1.157 markus 1983: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1984: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1985: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1986: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1987: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1988: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1989: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1990:
1.41 markus 1991: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1992: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1993: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1994: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1995: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1996: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1997: }
1.27 markus 1998:
1.127 itojun 1999: static void
1.41 markus 2000: channel_handler_init(void)
2001: {
2002: int i;
1.180 deraadt 2003:
1.148 deraadt 2004: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2005: channel_pre[i] = NULL;
2006: channel_post[i] = NULL;
2007: }
1.44 markus 2008: if (compat20)
2009: channel_handler_init_20();
2010: else if (compat13)
1.41 markus 2011: channel_handler_init_13();
2012: else
2013: channel_handler_init_15();
2014: }
1.25 markus 2015:
1.140 markus 2016: /* gc dead channels */
2017: static void
2018: channel_garbage_collect(Channel *c)
2019: {
2020: if (c == NULL)
2021: return;
2022: if (c->detach_user != NULL) {
1.225 djm 2023: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2024: return;
1.194 markus 2025: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2026: c->detach_user(c->self, NULL);
2027: /* if we still have a callback */
2028: if (c->detach_user != NULL)
2029: return;
1.194 markus 2030: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2031: }
2032: if (!chan_is_dead(c, 1))
2033: return;
1.194 markus 2034: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2035: channel_free(c);
2036: }
2037:
1.127 itojun 2038: static void
1.237 deraadt 2039: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 2040: {
2041: static int did_init = 0;
1.299 markus 2042: u_int i, oalloc;
1.41 markus 2043: Channel *c;
1.25 markus 2044:
1.41 markus 2045: if (!did_init) {
2046: channel_handler_init();
2047: did_init = 1;
2048: }
1.299 markus 2049: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2050: c = channels[i];
2051: if (c == NULL)
1.41 markus 2052: continue;
1.299 markus 2053: if (c->delayed) {
2054: if (ftab == channel_pre)
2055: c->delayed = 0;
2056: else
2057: continue;
2058: }
1.118 markus 2059: if (ftab[c->type] != NULL)
2060: (*ftab[c->type])(c, readset, writeset);
1.140 markus 2061: channel_garbage_collect(c);
1.1 deraadt 2062: }
2063: }
2064:
1.121 markus 2065: /*
2066: * Allocate/update select bitmasks and add any bits relevant to channels in
2067: * select bitmasks.
2068: */
1.49 markus 2069: void
1.100 markus 2070: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 2071: u_int *nallocp, int rekeying)
1.41 markus 2072: {
1.243 djm 2073: u_int n, sz, nfdset;
1.84 markus 2074:
2075: n = MAX(*maxfdp, channel_max_fd);
2076:
1.243 djm 2077: nfdset = howmany(n+1, NFDBITS);
2078: /* Explicitly test here, because xrealloc isn't always called */
2079: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2080: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2081: sz = nfdset * sizeof(fd_mask);
2082:
1.132 markus 2083: /* perhaps check sz < nalloc/2 and shrink? */
2084: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2085: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2086: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2087: *nallocp = sz;
1.84 markus 2088: }
1.132 markus 2089: *maxfdp = n;
1.84 markus 2090: memset(*readsetp, 0, sz);
2091: memset(*writesetp, 0, sz);
2092:
1.100 markus 2093: if (!rekeying)
2094: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 2095: }
2096:
1.121 markus 2097: /*
2098: * After select, perform any appropriate operations for channels which have
2099: * events pending.
2100: */
1.49 markus 2101: void
1.237 deraadt 2102: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2103: {
2104: channel_handler(channel_post, readset, writeset);
2105: }
2106:
1.121 markus 2107:
1.84 markus 2108: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2109: void
1.142 itojun 2110: channel_output_poll(void)
1.1 deraadt 2111: {
1.41 markus 2112: Channel *c;
1.209 avsm 2113: u_int i, len;
1.1 deraadt 2114:
1.25 markus 2115: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2116: c = channels[i];
2117: if (c == NULL)
2118: continue;
1.37 markus 2119:
1.121 markus 2120: /*
2121: * We are only interested in channels that can have buffered
2122: * incoming data.
2123: */
1.37 markus 2124: if (compat13) {
1.41 markus 2125: if (c->type != SSH_CHANNEL_OPEN &&
2126: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2127: continue;
2128: } else {
1.41 markus 2129: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2130: continue;
2131: }
1.46 markus 2132: if (compat20 &&
2133: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2134: /* XXX is this true? */
1.140 markus 2135: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2136: continue;
2137: }
1.25 markus 2138:
2139: /* Get the amount of buffered data for this channel. */
1.93 markus 2140: if ((c->istate == CHAN_INPUT_OPEN ||
2141: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2142: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2143: if (c->datagram) {
2144: if (len > 0) {
2145: u_char *data;
2146: u_int dlen;
2147:
2148: data = buffer_get_string(&c->input,
2149: &dlen);
1.309 djm 2150: if (dlen > c->remote_window ||
2151: dlen > c->remote_maxpacket) {
2152: debug("channel %d: datagram "
2153: "too big for channel",
2154: c->self);
2155: xfree(data);
2156: continue;
2157: }
1.228 reyk 2158: packet_start(SSH2_MSG_CHANNEL_DATA);
2159: packet_put_int(c->remote_id);
2160: packet_put_string(data, dlen);
2161: packet_send();
2162: c->remote_window -= dlen + 4;
2163: xfree(data);
2164: }
2165: continue;
2166: }
1.121 markus 2167: /*
2168: * Send some data for the other side over the secure
2169: * connection.
2170: */
1.44 markus 2171: if (compat20) {
2172: if (len > c->remote_window)
2173: len = c->remote_window;
2174: if (len > c->remote_maxpacket)
2175: len = c->remote_maxpacket;
1.25 markus 2176: } else {
1.44 markus 2177: if (packet_is_interactive()) {
2178: if (len > 1024)
2179: len = 512;
2180: } else {
2181: /* Keep the packets at reasonable size. */
2182: if (len > packet_get_maxsize()/2)
2183: len = packet_get_maxsize()/2;
2184: }
1.25 markus 2185: }
1.41 markus 2186: if (len > 0) {
1.44 markus 2187: packet_start(compat20 ?
2188: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2189: packet_put_int(c->remote_id);
2190: packet_put_string(buffer_ptr(&c->input), len);
2191: packet_send();
2192: buffer_consume(&c->input, len);
2193: c->remote_window -= len;
2194: }
2195: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2196: if (compat13)
2197: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2198: /*
2199: * input-buffer is empty and read-socket shutdown:
1.172 markus 2200: * tell peer, that we will not send more data: send IEOF.
2201: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2202: */
1.172 markus 2203: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2204: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2205: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2206: else
2207: chan_ibuf_empty(c);
1.25 markus 2208: }
1.44 markus 2209: /* Send extended data, i.e. stderr */
2210: if (compat20 &&
1.172 markus 2211: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2212: c->remote_window > 0 &&
2213: (len = buffer_len(&c->extended)) > 0 &&
2214: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2215: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2216: c->self, c->remote_window, buffer_len(&c->extended),
2217: c->extended_usage);
1.44 markus 2218: if (len > c->remote_window)
2219: len = c->remote_window;
2220: if (len > c->remote_maxpacket)
2221: len = c->remote_maxpacket;
2222: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2223: packet_put_int(c->remote_id);
2224: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2225: packet_put_string(buffer_ptr(&c->extended), len);
2226: packet_send();
2227: buffer_consume(&c->extended, len);
2228: c->remote_window -= len;
1.93 markus 2229: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2230: }
1.25 markus 2231: }
1.1 deraadt 2232: }
2233:
1.121 markus 2234:
2235: /* -- protocol input */
1.249 djm 2236:
2237: /* ARGSUSED */
1.49 markus 2238: void
1.154 markus 2239: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2240: {
1.37 markus 2241: int id;
1.25 markus 2242: char *data;
1.309 djm 2243: u_int data_len, win_len;
1.41 markus 2244: Channel *c;
1.25 markus 2245:
2246: /* Get the channel number and verify it. */
1.37 markus 2247: id = packet_get_int();
1.41 markus 2248: c = channel_lookup(id);
2249: if (c == NULL)
1.37 markus 2250: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2251:
2252: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2253: if (c->type != SSH_CHANNEL_OPEN &&
2254: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2255: return;
2256:
1.25 markus 2257: /* Get the data. */
1.274 markus 2258: data = packet_get_string_ptr(&data_len);
1.309 djm 2259: win_len = data_len;
2260: if (c->datagram)
2261: win_len += 4; /* string length header */
1.200 markus 2262:
2263: /*
2264: * Ignore data for protocol > 1.3 if output end is no longer open.
2265: * For protocol 2 the sending side is reducing its window as it sends
2266: * data, so we must 'fake' consumption of the data in order to ensure
2267: * that window updates are sent back. Otherwise the connection might
2268: * deadlock.
2269: */
2270: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2271: if (compat20) {
1.309 djm 2272: c->local_window -= win_len;
2273: c->local_consumed += win_len;
1.200 markus 2274: }
2275: return;
2276: }
1.41 markus 2277:
1.143 deraadt 2278: if (compat20) {
1.309 djm 2279: if (win_len > c->local_maxpacket) {
1.188 itojun 2280: logit("channel %d: rcvd big packet %d, maxpack %d",
1.309 djm 2281: c->self, win_len, c->local_maxpacket);
1.44 markus 2282: }
1.309 djm 2283: if (win_len > c->local_window) {
1.188 itojun 2284: logit("channel %d: rcvd too much data %d, win %d",
1.309 djm 2285: c->self, win_len, c->local_window);
1.44 markus 2286: return;
2287: }
1.309 djm 2288: c->local_window -= win_len;
1.44 markus 2289: }
1.228 reyk 2290: if (c->datagram)
2291: buffer_put_string(&c->output, data, data_len);
2292: else
2293: buffer_append(&c->output, data, data_len);
1.274 markus 2294: packet_check_eom();
1.1 deraadt 2295: }
1.121 markus 2296:
1.249 djm 2297: /* ARGSUSED */
1.49 markus 2298: void
1.154 markus 2299: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2300: {
2301: int id;
2302: char *data;
1.177 markus 2303: u_int data_len, tcode;
1.44 markus 2304: Channel *c;
2305:
2306: /* Get the channel number and verify it. */
2307: id = packet_get_int();
2308: c = channel_lookup(id);
2309:
2310: if (c == NULL)
2311: packet_disconnect("Received extended_data for bad channel %d.", id);
2312: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2313: logit("channel %d: ext data for non open", id);
1.44 markus 2314: return;
1.172 markus 2315: }
2316: if (c->flags & CHAN_EOF_RCVD) {
2317: if (datafellows & SSH_BUG_EXTEOF)
2318: debug("channel %d: accepting ext data after eof", id);
2319: else
2320: packet_disconnect("Received extended_data after EOF "
2321: "on channel %d.", id);
1.44 markus 2322: }
2323: tcode = packet_get_int();
2324: if (c->efd == -1 ||
2325: c->extended_usage != CHAN_EXTENDED_WRITE ||
2326: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2327: logit("channel %d: bad ext data", c->self);
1.44 markus 2328: return;
2329: }
2330: data = packet_get_string(&data_len);
1.152 markus 2331: packet_check_eom();
1.44 markus 2332: if (data_len > c->local_window) {
1.188 itojun 2333: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2334: c->self, data_len, c->local_window);
2335: xfree(data);
2336: return;
2337: }
1.70 markus 2338: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2339: c->local_window -= data_len;
2340: buffer_append(&c->extended, data, data_len);
2341: xfree(data);
2342: }
2343:
1.249 djm 2344: /* ARGSUSED */
1.49 markus 2345: void
1.154 markus 2346: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2347: {
2348: int id;
2349: Channel *c;
2350:
2351: id = packet_get_int();
1.152 markus 2352: packet_check_eom();
1.41 markus 2353: c = channel_lookup(id);
2354: if (c == NULL)
2355: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2356: chan_rcvd_ieof(c);
1.133 markus 2357:
2358: /* XXX force input close */
1.156 markus 2359: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2360: debug("channel %d: FORCE input drain", c->self);
2361: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2362: if (buffer_len(&c->input) == 0)
2363: chan_ibuf_empty(c);
1.133 markus 2364: }
2365:
1.41 markus 2366: }
1.1 deraadt 2367:
1.249 djm 2368: /* ARGSUSED */
1.49 markus 2369: void
1.154 markus 2370: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2371: {
1.41 markus 2372: int id;
2373: Channel *c;
1.1 deraadt 2374:
1.41 markus 2375: id = packet_get_int();
1.152 markus 2376: packet_check_eom();
1.41 markus 2377: c = channel_lookup(id);
2378: if (c == NULL)
2379: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2380:
2381: /*
2382: * Send a confirmation that we have closed the channel and no more
2383: * data is coming for it.
2384: */
1.25 markus 2385: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2386: packet_put_int(c->remote_id);
1.25 markus 2387: packet_send();
2388:
1.27 markus 2389: /*
2390: * If the channel is in closed state, we have sent a close request,
2391: * and the other side will eventually respond with a confirmation.
2392: * Thus, we cannot free the channel here, because then there would be
2393: * no-one to receive the confirmation. The channel gets freed when
2394: * the confirmation arrives.
2395: */
1.41 markus 2396: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2397: /*
2398: * Not a closed channel - mark it as draining, which will
2399: * cause it to be freed later.
2400: */
1.158 markus 2401: buffer_clear(&c->input);
1.41 markus 2402: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2403: }
1.1 deraadt 2404: }
2405:
1.41 markus 2406: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2407: /* ARGSUSED */
1.49 markus 2408: void
1.154 markus 2409: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2410: {
2411: int id = packet_get_int();
2412: Channel *c = channel_lookup(id);
1.151 markus 2413:
1.152 markus 2414: packet_check_eom();
1.41 markus 2415: if (c == NULL)
2416: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2417: chan_rcvd_oclose(c);
2418: }
1.1 deraadt 2419:
1.249 djm 2420: /* ARGSUSED */
1.49 markus 2421: void
1.154 markus 2422: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2423: {
1.41 markus 2424: int id = packet_get_int();
2425: Channel *c = channel_lookup(id);
1.1 deraadt 2426:
1.152 markus 2427: packet_check_eom();
1.41 markus 2428: if (c == NULL)
2429: packet_disconnect("Received close confirmation for "
2430: "out-of-range channel %d.", id);
2431: if (c->type != SSH_CHANNEL_CLOSED)
2432: packet_disconnect("Received close confirmation for "
2433: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2434: channel_free(c);
1.1 deraadt 2435: }
2436:
1.249 djm 2437: /* ARGSUSED */
1.49 markus 2438: void
1.154 markus 2439: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2440: {
1.41 markus 2441: int id, remote_id;
2442: Channel *c;
1.1 deraadt 2443:
1.41 markus 2444: id = packet_get_int();
2445: c = channel_lookup(id);
1.25 markus 2446:
1.41 markus 2447: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2448: packet_disconnect("Received open confirmation for "
2449: "non-opening channel %d.", id);
2450: remote_id = packet_get_int();
1.27 markus 2451: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2452: c->remote_id = remote_id;
2453: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2454:
2455: if (compat20) {
2456: c->remote_window = packet_get_int();
2457: c->remote_maxpacket = packet_get_int();
1.275 djm 2458: if (c->open_confirm) {
1.70 markus 2459: debug2("callback start");
1.304 djm 2460: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2461: debug2("callback done");
1.44 markus 2462: }
1.194 markus 2463: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2464: c->remote_window, c->remote_maxpacket);
2465: }
1.152 markus 2466: packet_check_eom();
1.1 deraadt 2467: }
2468:
1.127 itojun 2469: static char *
1.114 markus 2470: reason2txt(int reason)
2471: {
1.143 deraadt 2472: switch (reason) {
1.114 markus 2473: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2474: return "administratively prohibited";
2475: case SSH2_OPEN_CONNECT_FAILED:
2476: return "connect failed";
2477: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2478: return "unknown channel type";
2479: case SSH2_OPEN_RESOURCE_SHORTAGE:
2480: return "resource shortage";
2481: }
1.117 stevesk 2482: return "unknown reason";
1.114 markus 2483: }
2484:
1.249 djm 2485: /* ARGSUSED */
1.49 markus 2486: void
1.154 markus 2487: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2488: {
1.86 markus 2489: int id, reason;
2490: char *msg = NULL, *lang = NULL;
1.41 markus 2491: Channel *c;
2492:
2493: id = packet_get_int();
2494: c = channel_lookup(id);
1.25 markus 2495:
1.41 markus 2496: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2497: packet_disconnect("Received open failure for "
2498: "non-opening channel %d.", id);
1.44 markus 2499: if (compat20) {
1.86 markus 2500: reason = packet_get_int();
1.110 markus 2501: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2502: msg = packet_get_string(NULL);
2503: lang = packet_get_string(NULL);
2504: }
1.188 itojun 2505: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2506: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2507: if (msg != NULL)
2508: xfree(msg);
2509: if (lang != NULL)
2510: xfree(lang);
1.304 djm 2511: if (c->open_confirm) {
2512: debug2("callback start");
2513: c->open_confirm(c->self, 0, c->open_confirm_ctx);
2514: debug2("callback done");
2515: }
1.44 markus 2516: }
1.152 markus 2517: packet_check_eom();
1.291 djm 2518: /* Schedule the channel for cleanup/deletion. */
2519: chan_mark_dead(c);
1.44 markus 2520: }
2521:
1.249 djm 2522: /* ARGSUSED */
1.121 markus 2523: void
1.154 markus 2524: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2525: {
2526: Channel *c;
1.178 markus 2527: int id;
2528: u_int adjust;
1.121 markus 2529:
2530: if (!compat20)
2531: return;
2532:
2533: /* Get the channel number and verify it. */
2534: id = packet_get_int();
2535: c = channel_lookup(id);
1.1 deraadt 2536:
1.229 markus 2537: if (c == NULL) {
2538: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2539: return;
2540: }
2541: adjust = packet_get_int();
1.152 markus 2542: packet_check_eom();
1.178 markus 2543: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2544: c->remote_window += adjust;
2545: }
1.1 deraadt 2546:
1.249 djm 2547: /* ARGSUSED */
1.121 markus 2548: void
1.154 markus 2549: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2550: {
1.121 markus 2551: Channel *c = NULL;
2552: u_short host_port;
2553: char *host, *originator_string;
1.276 djm 2554: int remote_id;
1.121 markus 2555:
2556: remote_id = packet_get_int();
2557: host = packet_get_string(NULL);
2558: host_port = packet_get_int();
1.25 markus 2559:
1.121 markus 2560: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2561: originator_string = packet_get_string(NULL);
2562: } else {
2563: originator_string = xstrdup("unknown (remote did not supply name)");
2564: }
1.152 markus 2565: packet_check_eom();
1.276 djm 2566: c = channel_connect_to(host, host_port,
2567: "connected socket", originator_string);
1.190 markus 2568: xfree(originator_string);
1.276 djm 2569: xfree(host);
1.121 markus 2570: if (c == NULL) {
2571: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2572: packet_put_int(remote_id);
2573: packet_send();
1.276 djm 2574: } else
2575: c->remote_id = remote_id;
1.1 deraadt 2576: }
2577:
1.275 djm 2578: /* ARGSUSED */
2579: void
2580: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2581: {
2582: Channel *c;
2583: struct channel_confirm *cc;
1.289 markus 2584: int id;
1.275 djm 2585:
2586: /* Reset keepalive timeout */
1.296 andreas 2587: packet_set_alive_timeouts(0);
1.275 djm 2588:
1.289 markus 2589: id = packet_get_int();
1.275 djm 2590: packet_check_eom();
2591:
1.289 markus 2592: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2593:
1.289 markus 2594: if ((c = channel_lookup(id)) == NULL) {
2595: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2596: return;
2597: }
2598: ;
2599: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2600: return;
2601: cc->cb(type, c, cc->ctx);
2602: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2603: bzero(cc, sizeof(*cc));
2604: xfree(cc);
2605: }
1.121 markus 2606:
2607: /* -- tcp forwarding */
1.135 markus 2608:
2609: void
2610: channel_set_af(int af)
2611: {
2612: IPv4or6 = af;
2613: }
1.121 markus 2614:
1.160 markus 2615: static int
1.295 djm 2616: channel_setup_fwd_listener(int type, const char *listen_addr,
2617: u_short listen_port, int *allocated_listen_port,
1.160 markus 2618: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2619: {
1.113 markus 2620: Channel *c;
1.226 djm 2621: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2622: struct addrinfo hints, *ai, *aitop;
1.212 djm 2623: const char *host, *addr;
1.35 markus 2624: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2625: in_port_t *lport_p;
1.25 markus 2626:
1.160 markus 2627: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2628: listen_addr : host_to_connect;
1.212 djm 2629: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2630:
1.160 markus 2631: if (host == NULL) {
2632: error("No forward host name.");
1.218 markus 2633: return 0;
1.73 markus 2634: }
1.294 djm 2635: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2636: error("Forward host name too long.");
1.218 markus 2637: return 0;
1.87 markus 2638: }
1.25 markus 2639:
1.28 markus 2640: /*
1.212 djm 2641: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2642: * specified address or wildcard. On the client, a specified bind
2643: * address will always override gateway_ports. On the server, a
2644: * gateway_ports of 1 (``yes'') will override the client's
2645: * specification and force a wildcard bind, whereas a value of 2
2646: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2647: * asked for.
2648: *
2649: * Special-case listen_addrs are:
2650: *
2651: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2652: * "" (empty string), "*" -> wildcard v4/v6
2653: * "localhost" -> loopback v4/v6
2654: */
2655: addr = NULL;
2656: if (listen_addr == NULL) {
2657: /* No address specified: default to gateway_ports setting */
2658: if (gateway_ports)
2659: wildcard = 1;
2660: } else if (gateway_ports || is_client) {
2661: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
1.272 djm 2662: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
1.212 djm 2663: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2664: (!is_client && gateway_ports == 1))
2665: wildcard = 1;
2666: else if (strcmp(listen_addr, "localhost") != 0)
2667: addr = listen_addr;
2668: }
2669:
2670: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2671: type, wildcard, (addr == NULL) ? "NULL" : addr);
2672:
2673: /*
1.35 markus 2674: * getaddrinfo returns a loopback address if the hostname is
2675: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2676: */
1.35 markus 2677: memset(&hints, 0, sizeof(hints));
2678: hints.ai_family = IPv4or6;
1.212 djm 2679: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2680: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2681: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2682: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2683: if (addr == NULL) {
2684: /* This really shouldn't happen */
2685: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2686: ssh_gai_strerror(r));
1.212 djm 2687: } else {
1.218 markus 2688: error("channel_setup_fwd_listener: "
1.271 dtucker 2689: "getaddrinfo(%.64s): %s", addr,
2690: ssh_gai_strerror(r));
1.212 djm 2691: }
1.218 markus 2692: return 0;
1.212 djm 2693: }
1.295 djm 2694: if (allocated_listen_port != NULL)
2695: *allocated_listen_port = 0;
1.35 markus 2696: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2697: switch (ai->ai_family) {
2698: case AF_INET:
2699: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2700: sin_port;
2701: break;
2702: case AF_INET6:
2703: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2704: sin6_port;
2705: break;
2706: default:
1.35 markus 2707: continue;
1.295 djm 2708: }
2709: /*
2710: * If allocating a port for -R forwards, then use the
2711: * same port for all address families.
2712: */
2713: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2714: allocated_listen_port != NULL && *allocated_listen_port > 0)
2715: *lport_p = htons(*allocated_listen_port);
2716:
1.35 markus 2717: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2718: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2719: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2720: continue;
2721: }
2722: /* Create a port to listen for the host. */
1.300 dtucker 2723: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2724: if (sock < 0) {
2725: /* this is no error since kernel may not support ipv6 */
2726: verbose("socket: %.100s", strerror(errno));
2727: continue;
2728: }
1.226 djm 2729:
2730: channel_set_reuseaddr(sock);
1.182 stevesk 2731:
1.295 djm 2732: debug("Local forwarding listening on %s port %s.",
2733: ntop, strport);
1.35 markus 2734:
2735: /* Bind the socket to the address. */
2736: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2737: /* address can be in use ipv6 address is already bound */
2738: verbose("bind: %.100s", strerror(errno));
2739: close(sock);
2740: continue;
2741: }
2742: /* Start listening for connections on the socket. */
1.199 markus 2743: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2744: error("listen: %.100s", strerror(errno));
2745: close(sock);
2746: continue;
2747: }
1.295 djm 2748:
2749: /*
2750: * listen_port == 0 requests a dynamically allocated port -
2751: * record what we got.
2752: */
2753: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2754: allocated_listen_port != NULL &&
2755: *allocated_listen_port == 0) {
2756: *allocated_listen_port = get_sock_port(sock, 1);
2757: debug("Allocated listen port %d",
2758: *allocated_listen_port);
2759: }
2760:
1.35 markus 2761: /* Allocate a channel number for the socket. */
1.121 markus 2762: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2763: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2764: 0, "port listener", 1);
1.293 djm 2765: c->path = xstrdup(host);
1.113 markus 2766: c->host_port = port_to_connect;
2767: c->listening_port = listen_port;
1.35 markus 2768: success = 1;
2769: }
2770: if (success == 0)
1.160 markus 2771: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2772: listen_port);
1.35 markus 2773: freeaddrinfo(aitop);
1.87 markus 2774: return success;
1.25 markus 2775: }
1.1 deraadt 2776:
1.202 djm 2777: int
2778: channel_cancel_rport_listener(const char *host, u_short port)
2779: {
1.209 avsm 2780: u_int i;
2781: int found = 0;
1.202 djm 2782:
1.213 deraadt 2783: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2784: Channel *c = channels[i];
2785:
2786: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
1.293 djm 2787: strcmp(c->path, host) == 0 && c->listening_port == port) {
1.210 djm 2788: debug2("%s: close channel %d", __func__, i);
1.202 djm 2789: channel_free(c);
2790: found = 1;
2791: }
2792: }
2793:
2794: return (found);
2795: }
2796:
1.160 markus 2797: /* protocol local port fwd, used by ssh (and sshd in v1) */
2798: int
1.212 djm 2799: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2800: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2801: {
2802: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2803: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2804: gateway_ports);
1.160 markus 2805: }
2806:
2807: /* protocol v2 remote port fwd, used by sshd */
2808: int
2809: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2810: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2811: {
2812: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2813: listen_address, listen_port, allocated_listen_port,
2814: NULL, 0, gateway_ports);
1.160 markus 2815: }
2816:
1.27 markus 2817: /*
2818: * Initiate forwarding of connections to port "port" on remote host through
2819: * the secure channel to host:port from local side.
2820: */
1.1 deraadt 2821:
1.253 markus 2822: int
1.212 djm 2823: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2824: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2825: {
1.153 markus 2826: int type, success = 0;
1.73 markus 2827:
1.25 markus 2828: /* Send the forward request to the remote side. */
1.44 markus 2829: if (compat20) {
1.212 djm 2830: const char *address_to_bind;
1.267 djm 2831: if (listen_host == NULL) {
2832: if (datafellows & SSH_BUG_RFWD_ADDR)
2833: address_to_bind = "127.0.0.1";
2834: else
2835: address_to_bind = "localhost";
2836: } else if (*listen_host == '\0' ||
2837: strcmp(listen_host, "*") == 0) {
2838: if (datafellows & SSH_BUG_RFWD_ADDR)
2839: address_to_bind = "0.0.0.0";
2840: else
2841: address_to_bind = "";
2842: } else
1.212 djm 2843: address_to_bind = listen_host;
2844:
1.44 markus 2845: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2846: packet_put_cstring("tcpip-forward");
1.173 markus 2847: packet_put_char(1); /* boolean: want reply */
1.44 markus 2848: packet_put_cstring(address_to_bind);
2849: packet_put_int(listen_port);
1.73 markus 2850: packet_send();
2851: packet_write_wait();
2852: /* Assume that server accepts the request */
2853: success = 1;
1.44 markus 2854: } else {
2855: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2856: packet_put_int(listen_port);
2857: packet_put_cstring(host_to_connect);
1.44 markus 2858: packet_put_int(port_to_connect);
2859: packet_send();
2860: packet_write_wait();
1.73 markus 2861:
2862: /* Wait for response from the remote side. */
1.153 markus 2863: type = packet_read();
1.73 markus 2864: switch (type) {
2865: case SSH_SMSG_SUCCESS:
2866: success = 1;
2867: break;
2868: case SSH_SMSG_FAILURE:
2869: break;
2870: default:
2871: /* Unknown packet */
2872: packet_disconnect("Protocol error for port forward request:"
2873: "received packet type %d.", type);
2874: }
2875: }
2876: if (success) {
1.305 djm 2877: /* Record that connection to this host/port is permitted. */
2878: permitted_opens = xrealloc(permitted_opens,
2879: num_permitted_opens + 1, sizeof(*permitted_opens));
1.73 markus 2880: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2881: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2882: permitted_opens[num_permitted_opens].listen_port = listen_port;
2883: num_permitted_opens++;
1.44 markus 2884: }
1.253 markus 2885: return (success ? 0 : -1);
1.1 deraadt 2886: }
2887:
1.27 markus 2888: /*
1.208 deraadt 2889: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2890: * local side.
2891: */
2892: void
1.212 djm 2893: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2894: {
2895: int i;
2896:
2897: if (!compat20)
2898: return;
2899:
2900: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2901: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2902: permitted_opens[i].listen_port == port)
2903: break;
2904: }
2905: if (i >= num_permitted_opens) {
2906: debug("%s: requested forward not found", __func__);
2907: return;
2908: }
2909: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2910: packet_put_cstring("cancel-tcpip-forward");
2911: packet_put_char(0);
1.212 djm 2912: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2913: packet_put_int(port);
2914: packet_send();
2915:
2916: permitted_opens[i].listen_port = 0;
2917: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2918: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2919: permitted_opens[i].host_to_connect = NULL;
2920: }
2921:
2922: /*
1.27 markus 2923: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2924: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2925: * message if there was an error).
1.27 markus 2926: */
1.253 markus 2927: int
1.56 markus 2928: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2929: {
1.31 markus 2930: u_short port, host_port;
1.253 markus 2931: int success = 0;
1.25 markus 2932: char *hostname;
1.1 deraadt 2933:
1.25 markus 2934: /* Get arguments from the packet. */
2935: port = packet_get_int();
2936: hostname = packet_get_string(NULL);
2937: host_port = packet_get_int();
2938:
1.27 markus 2939: /*
2940: * Check that an unprivileged user is not trying to forward a
2941: * privileged port.
2942: */
1.25 markus 2943: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2944: packet_disconnect(
2945: "Requested forwarding of port %d but user is not root.",
2946: port);
2947: if (host_port == 0)
2948: packet_disconnect("Dynamic forwarding denied.");
2949:
1.73 markus 2950: /* Initiate forwarding */
1.253 markus 2951: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2952: host_port, gateway_ports);
1.25 markus 2953:
2954: /* Free the argument string. */
2955: xfree(hostname);
1.253 markus 2956:
2957: return (success ? 0 : -1);
1.1 deraadt 2958: }
2959:
1.99 markus 2960: /*
2961: * Permits opening to any host/port if permitted_opens[] is empty. This is
2962: * usually called by the server, because the user could connect to any port
2963: * anyway, and the server has no way to know but to trust the client anyway.
2964: */
2965: void
1.142 itojun 2966: channel_permit_all_opens(void)
1.99 markus 2967: {
2968: if (num_permitted_opens == 0)
2969: all_opens_permitted = 1;
2970: }
2971:
1.101 markus 2972: void
1.99 markus 2973: channel_add_permitted_opens(char *host, int port)
2974: {
2975: debug("allow port forwarding to host %s port %d", host, port);
2976:
1.305 djm 2977: permitted_opens = xrealloc(permitted_opens,
2978: num_permitted_opens + 1, sizeof(*permitted_opens));
1.99 markus 2979: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2980: permitted_opens[num_permitted_opens].port_to_connect = port;
2981: num_permitted_opens++;
2982:
2983: all_opens_permitted = 0;
2984: }
2985:
1.258 dtucker 2986: int
1.257 dtucker 2987: channel_add_adm_permitted_opens(char *host, int port)
2988: {
1.258 dtucker 2989: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 2990:
1.305 djm 2991: permitted_adm_opens = xrealloc(permitted_adm_opens,
2992: num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
1.257 dtucker 2993: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2994: = xstrdup(host);
2995: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 2996: return ++num_adm_permitted_opens;
1.257 dtucker 2997: }
2998:
2999: void
1.99 markus 3000: channel_clear_permitted_opens(void)
3001: {
3002: int i;
3003:
3004: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3005: if (permitted_opens[i].host_to_connect != NULL)
3006: xfree(permitted_opens[i].host_to_connect);
1.305 djm 3007: if (num_permitted_opens > 0) {
3008: xfree(permitted_opens);
3009: permitted_opens = NULL;
3010: }
1.99 markus 3011: num_permitted_opens = 0;
1.257 dtucker 3012: }
3013:
3014: void
3015: channel_clear_adm_permitted_opens(void)
3016: {
3017: int i;
1.99 markus 3018:
1.257 dtucker 3019: for (i = 0; i < num_adm_permitted_opens; i++)
3020: if (permitted_adm_opens[i].host_to_connect != NULL)
3021: xfree(permitted_adm_opens[i].host_to_connect);
1.305 djm 3022: if (num_adm_permitted_opens > 0) {
3023: xfree(permitted_adm_opens);
3024: permitted_adm_opens = NULL;
3025: }
1.257 dtucker 3026: num_adm_permitted_opens = 0;
1.278 dtucker 3027: }
3028:
3029: void
3030: channel_print_adm_permitted_opens(void)
3031: {
1.286 djm 3032: int i;
1.278 dtucker 3033:
1.290 stevesk 3034: printf("permitopen");
1.288 stevesk 3035: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3036: printf(" any\n");
1.288 stevesk 3037: return;
3038: }
1.278 dtucker 3039: for (i = 0; i < num_adm_permitted_opens; i++)
3040: if (permitted_adm_opens[i].host_to_connect != NULL)
3041: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3042: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3043: printf("\n");
1.99 markus 3044: }
3045:
1.276 djm 3046: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3047: static int
1.276 djm 3048: connect_next(struct channel_connect *cctx)
1.41 markus 3049: {
1.276 djm 3050: int sock, saved_errno;
1.41 markus 3051: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3052:
1.276 djm 3053: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3054: if (cctx->ai->ai_family != AF_INET &&
3055: cctx->ai->ai_family != AF_INET6)
1.41 markus 3056: continue;
1.276 djm 3057: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3058: ntop, sizeof(ntop), strport, sizeof(strport),
3059: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3060: error("connect_next: getnameinfo failed");
1.41 markus 3061: continue;
3062: }
1.300 dtucker 3063: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3064: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3065: if (cctx->ai->ai_next == NULL)
1.186 djm 3066: error("socket: %.100s", strerror(errno));
3067: else
3068: verbose("socket: %.100s", strerror(errno));
1.41 markus 3069: continue;
3070: }
1.205 djm 3071: if (set_nonblock(sock) == -1)
3072: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3073: if (connect(sock, cctx->ai->ai_addr,
3074: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3075: debug("connect_next: host %.100s ([%.100s]:%s): "
3076: "%.100s", cctx->host, ntop, strport,
1.41 markus 3077: strerror(errno));
1.276 djm 3078: saved_errno = errno;
1.41 markus 3079: close(sock);
1.276 djm 3080: errno = saved_errno;
1.89 stevesk 3081: continue; /* fail -- try next */
1.41 markus 3082: }
1.276 djm 3083: debug("connect_next: host %.100s ([%.100s]:%s) "
3084: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3085: cctx->ai = cctx->ai->ai_next;
3086: set_nodelay(sock);
3087: return sock;
3088: }
3089: return -1;
3090: }
1.41 markus 3091:
1.276 djm 3092: static void
3093: channel_connect_ctx_free(struct channel_connect *cctx)
3094: {
3095: xfree(cctx->host);
3096: if (cctx->aitop)
3097: freeaddrinfo(cctx->aitop);
3098: bzero(cctx, sizeof(*cctx));
3099: cctx->host = NULL;
3100: cctx->ai = cctx->aitop = NULL;
3101: }
3102:
3103: /* Return CONNECTING channel to remote host, port */
3104: static Channel *
3105: connect_to(const char *host, u_short port, char *ctype, char *rname)
3106: {
3107: struct addrinfo hints;
3108: int gaierr;
3109: int sock = -1;
3110: char strport[NI_MAXSERV];
3111: struct channel_connect cctx;
3112: Channel *c;
3113:
1.284 djm 3114: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3115: memset(&hints, 0, sizeof(hints));
3116: hints.ai_family = IPv4or6;
3117: hints.ai_socktype = SOCK_STREAM;
3118: snprintf(strport, sizeof strport, "%d", port);
3119: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3120: error("connect_to %.100s: unknown host (%s)", host,
3121: ssh_gai_strerror(gaierr));
3122: return NULL;
1.41 markus 3123: }
1.276 djm 3124:
3125: cctx.host = xstrdup(host);
3126: cctx.port = port;
3127: cctx.ai = cctx.aitop;
3128:
3129: if ((sock = connect_next(&cctx)) == -1) {
3130: error("connect to %.100s port %d failed: %s",
3131: host, port, strerror(errno));
3132: channel_connect_ctx_free(&cctx);
3133: return NULL;
1.41 markus 3134: }
1.276 djm 3135: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3136: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3137: c->connect_ctx = cctx;
3138: return c;
1.41 markus 3139: }
1.99 markus 3140:
1.276 djm 3141: Channel *
3142: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3143: {
3144: int i;
1.99 markus 3145:
1.276 djm 3146: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3147: if (permitted_opens[i].host_to_connect != NULL &&
1.276 djm 3148: permitted_opens[i].listen_port == listen_port) {
1.99 markus 3149: return connect_to(
1.73 markus 3150: permitted_opens[i].host_to_connect,
1.276 djm 3151: permitted_opens[i].port_to_connect, ctype, rname);
3152: }
3153: }
1.74 markus 3154: error("WARNING: Server requests forwarding for unknown listen_port %d",
3155: listen_port);
1.276 djm 3156: return NULL;
1.73 markus 3157: }
3158:
1.99 markus 3159: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3160: Channel *
3161: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3162: {
1.257 dtucker 3163: int i, permit, permit_adm = 1;
1.99 markus 3164:
3165: permit = all_opens_permitted;
3166: if (!permit) {
3167: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3168: if (permitted_opens[i].host_to_connect != NULL &&
3169: permitted_opens[i].port_to_connect == port &&
1.99 markus 3170: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3171: permit = 1;
1.257 dtucker 3172: }
1.99 markus 3173:
1.257 dtucker 3174: if (num_adm_permitted_opens > 0) {
3175: permit_adm = 0;
3176: for (i = 0; i < num_adm_permitted_opens; i++)
3177: if (permitted_adm_opens[i].host_to_connect != NULL &&
3178: permitted_adm_opens[i].port_to_connect == port &&
3179: strcmp(permitted_adm_opens[i].host_to_connect, host)
3180: == 0)
3181: permit_adm = 1;
1.99 markus 3182: }
1.257 dtucker 3183:
3184: if (!permit || !permit_adm) {
1.188 itojun 3185: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3186: "but the request was denied.", host, port);
1.276 djm 3187: return NULL;
1.99 markus 3188: }
1.276 djm 3189: return connect_to(host, port, ctype, rname);
1.204 djm 3190: }
3191:
3192: void
3193: channel_send_window_changes(void)
3194: {
1.209 avsm 3195: u_int i;
1.204 djm 3196: struct winsize ws;
3197:
3198: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3199: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3200: channels[i]->type != SSH_CHANNEL_OPEN)
3201: continue;
3202: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3203: continue;
3204: channel_request_start(i, "window-change", 0);
1.238 deraadt 3205: packet_put_int((u_int)ws.ws_col);
3206: packet_put_int((u_int)ws.ws_row);
3207: packet_put_int((u_int)ws.ws_xpixel);
3208: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3209: packet_send();
3210: }
1.99 markus 3211: }
3212:
1.121 markus 3213: /* -- X11 forwarding */
1.1 deraadt 3214:
1.27 markus 3215: /*
3216: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3217: * Returns 0 and a suitable display number for the DISPLAY variable
3218: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3219: */
1.141 stevesk 3220: int
1.163 stevesk 3221: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3222: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3223: {
1.149 markus 3224: Channel *nc = NULL;
1.31 markus 3225: int display_number, sock;
3226: u_short port;
1.35 markus 3227: struct addrinfo hints, *ai, *aitop;
3228: char strport[NI_MAXSERV];
3229: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3230:
1.224 markus 3231: if (chanids == NULL)
3232: return -1;
3233:
1.33 markus 3234: for (display_number = x11_display_offset;
1.148 deraadt 3235: display_number < MAX_DISPLAYS;
3236: display_number++) {
1.25 markus 3237: port = 6000 + display_number;
1.35 markus 3238: memset(&hints, 0, sizeof(hints));
3239: hints.ai_family = IPv4or6;
1.163 stevesk 3240: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3241: hints.ai_socktype = SOCK_STREAM;
3242: snprintf(strport, sizeof strport, "%d", port);
3243: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3244: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3245: return -1;
1.25 markus 3246: }
1.35 markus 3247: for (ai = aitop; ai; ai = ai->ai_next) {
3248: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3249: continue;
1.300 dtucker 3250: sock = socket(ai->ai_family, ai->ai_socktype,
3251: ai->ai_protocol);
1.35 markus 3252: if (sock < 0) {
3253: error("socket: %.100s", strerror(errno));
1.203 markus 3254: freeaddrinfo(aitop);
1.141 stevesk 3255: return -1;
1.35 markus 3256: }
1.226 djm 3257: channel_set_reuseaddr(sock);
1.35 markus 3258: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3259: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3260: close(sock);
1.183 itojun 3261:
1.35 markus 3262: for (n = 0; n < num_socks; n++) {
3263: close(socks[n]);
3264: }
3265: num_socks = 0;
3266: break;
3267: }
3268: socks[num_socks++] = sock;
3269: if (num_socks == NUM_SOCKS)
3270: break;
1.25 markus 3271: }
1.83 stevesk 3272: freeaddrinfo(aitop);
1.35 markus 3273: if (num_socks > 0)
3274: break;
1.25 markus 3275: }
3276: if (display_number >= MAX_DISPLAYS) {
3277: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3278: return -1;
1.25 markus 3279: }
3280: /* Start listening for connections on the socket. */
1.35 markus 3281: for (n = 0; n < num_socks; n++) {
3282: sock = socks[n];
1.199 markus 3283: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3284: error("listen: %.100s", strerror(errno));
3285: close(sock);
1.141 stevesk 3286: return -1;
1.35 markus 3287: }
1.25 markus 3288: }
1.35 markus 3289:
3290: /* Allocate a channel for each socket. */
1.242 djm 3291: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3292: for (n = 0; n < num_socks; n++) {
3293: sock = socks[n];
1.149 markus 3294: nc = channel_new("x11 listener",
1.51 markus 3295: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3296: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3297: 0, "X11 inet listener", 1);
1.167 markus 3298: nc->single_connection = single_connection;
1.224 markus 3299: (*chanids)[n] = nc->self;
1.35 markus 3300: }
1.224 markus 3301: (*chanids)[n] = -1;
1.1 deraadt 3302:
1.141 stevesk 3303: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3304: *display_numberp = display_number;
3305: return (0);
1.1 deraadt 3306: }
3307:
1.127 itojun 3308: static int
1.77 markus 3309: connect_local_xsocket(u_int dnr)
1.1 deraadt 3310: {
1.25 markus 3311: int sock;
3312: struct sockaddr_un addr;
3313:
1.147 stevesk 3314: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3315: if (sock < 0)
3316: error("socket: %.100s", strerror(errno));
3317: memset(&addr, 0, sizeof(addr));
3318: addr.sun_family = AF_UNIX;
3319: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3320: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3321: return sock;
3322: close(sock);
1.25 markus 3323: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3324: return -1;
1.1 deraadt 3325: }
3326:
1.51 markus 3327: int
3328: x11_connect_display(void)
1.1 deraadt 3329: {
1.248 deraadt 3330: u_int display_number;
1.25 markus 3331: const char *display;
1.51 markus 3332: char buf[1024], *cp;
1.35 markus 3333: struct addrinfo hints, *ai, *aitop;
3334: char strport[NI_MAXSERV];
1.248 deraadt 3335: int gaierr, sock = 0;
1.25 markus 3336:
3337: /* Try to open a socket for the local X server. */
3338: display = getenv("DISPLAY");
3339: if (!display) {
3340: error("DISPLAY not set.");
1.51 markus 3341: return -1;
1.25 markus 3342: }
1.27 markus 3343: /*
3344: * Now we decode the value of the DISPLAY variable and make a
3345: * connection to the real X server.
3346: */
3347:
3348: /*
3349: * Check if it is a unix domain socket. Unix domain displays are in
3350: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3351: */
1.25 markus 3352: if (strncmp(display, "unix:", 5) == 0 ||
3353: display[0] == ':') {
3354: /* Connect to the unix domain socket. */
1.248 deraadt 3355: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3356: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3357: display);
1.51 markus 3358: return -1;
1.25 markus 3359: }
3360: /* Create a socket. */
3361: sock = connect_local_xsocket(display_number);
3362: if (sock < 0)
1.51 markus 3363: return -1;
1.25 markus 3364:
3365: /* OK, we now have a connection to the display. */
1.51 markus 3366: return sock;
1.25 markus 3367: }
1.27 markus 3368: /*
3369: * Connect to an inet socket. The DISPLAY value is supposedly
3370: * hostname:d[.s], where hostname may also be numeric IP address.
3371: */
1.145 stevesk 3372: strlcpy(buf, display, sizeof(buf));
1.25 markus 3373: cp = strchr(buf, ':');
3374: if (!cp) {
3375: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3376: return -1;
1.25 markus 3377: }
3378: *cp = 0;
1.27 markus 3379: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3380: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 3381: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3382: display);
1.51 markus 3383: return -1;
1.25 markus 3384: }
1.35 markus 3385:
3386: /* Look up the host address */
3387: memset(&hints, 0, sizeof(hints));
3388: hints.ai_family = IPv4or6;
3389: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3390: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3391: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3392: error("%.100s: unknown host. (%s)", buf,
3393: ssh_gai_strerror(gaierr));
1.51 markus 3394: return -1;
1.25 markus 3395: }
1.35 markus 3396: for (ai = aitop; ai; ai = ai->ai_next) {
3397: /* Create a socket. */
1.300 dtucker 3398: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3399: if (sock < 0) {
1.194 markus 3400: debug2("socket: %.100s", strerror(errno));
1.41 markus 3401: continue;
3402: }
3403: /* Connect it to the display. */
3404: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3405: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3406: 6000 + display_number, strerror(errno));
3407: close(sock);
3408: continue;
3409: }
3410: /* Success */
3411: break;
1.35 markus 3412: }
3413: freeaddrinfo(aitop);
3414: if (!ai) {
1.248 deraadt 3415: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3416: strerror(errno));
1.51 markus 3417: return -1;
1.25 markus 3418: }
1.162 stevesk 3419: set_nodelay(sock);
1.51 markus 3420: return sock;
3421: }
3422:
3423: /*
3424: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3425: * the remote channel number. We should do whatever we want, and respond
3426: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3427: */
3428:
1.259 stevesk 3429: /* ARGSUSED */
1.51 markus 3430: void
1.154 markus 3431: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3432: {
1.113 markus 3433: Channel *c = NULL;
3434: int remote_id, sock = 0;
1.51 markus 3435: char *remote_host;
1.25 markus 3436:
1.113 markus 3437: debug("Received X11 open request.");
1.51 markus 3438:
1.113 markus 3439: remote_id = packet_get_int();
1.121 markus 3440:
3441: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3442: remote_host = packet_get_string(NULL);
1.51 markus 3443: } else {
3444: remote_host = xstrdup("unknown (remote did not supply name)");
3445: }
1.152 markus 3446: packet_check_eom();
1.25 markus 3447:
1.51 markus 3448: /* Obtain a connection to the real X display. */
3449: sock = x11_connect_display();
1.113 markus 3450: if (sock != -1) {
3451: /* Allocate a channel for this connection. */
3452: c = channel_new("connected x11 socket",
3453: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3454: remote_host, 1);
1.167 markus 3455: c->remote_id = remote_id;
3456: c->force_drain = 1;
1.113 markus 3457: }
1.190 markus 3458: xfree(remote_host);
1.113 markus 3459: if (c == NULL) {
1.51 markus 3460: /* Send refusal to the remote host. */
3461: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3462: packet_put_int(remote_id);
1.51 markus 3463: } else {
3464: /* Send a confirmation to the remote host. */
3465: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3466: packet_put_int(remote_id);
3467: packet_put_int(c->self);
1.51 markus 3468: }
1.113 markus 3469: packet_send();
1.72 markus 3470: }
3471:
3472: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3473: /* ARGSUSED */
1.72 markus 3474: void
1.154 markus 3475: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3476: {
3477: int rchan = packet_get_int();
1.180 deraadt 3478:
1.143 deraadt 3479: switch (type) {
1.72 markus 3480: case SSH_SMSG_AGENT_OPEN:
3481: error("Warning: ssh server tried agent forwarding.");
3482: break;
3483: case SSH_SMSG_X11_OPEN:
3484: error("Warning: ssh server tried X11 forwarding.");
3485: break;
3486: default:
1.154 markus 3487: error("deny_input_open: type %d", type);
1.72 markus 3488: break;
3489: }
1.230 stevesk 3490: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3491: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3492: packet_put_int(rchan);
3493: packet_send();
1.1 deraadt 3494: }
3495:
1.27 markus 3496: /*
3497: * Requests forwarding of X11 connections, generates fake authentication
3498: * data, and enables authentication spoofing.
1.121 markus 3499: * This should be called in the client only.
1.27 markus 3500: */
1.49 markus 3501: void
1.215 djm 3502: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.311 ! djm 3503: const char *proto, const char *data, int want_reply)
1.1 deraadt 3504: {
1.77 markus 3505: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3506: u_int i, value;
1.25 markus 3507: char *new_data;
3508: int screen_number;
3509: const char *cp;
1.207 avsm 3510: u_int32_t rnd = 0;
1.25 markus 3511:
1.220 markus 3512: if (x11_saved_display == NULL)
3513: x11_saved_display = xstrdup(disp);
3514: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3515: error("x11_request_forwarding_with_spoofing: different "
3516: "$DISPLAY already forwarded");
3517: return;
3518: }
3519:
1.266 djm 3520: cp = strchr(disp, ':');
1.25 markus 3521: if (cp)
3522: cp = strchr(cp, '.');
3523: if (cp)
1.245 deraadt 3524: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3525: else
3526: screen_number = 0;
3527:
1.219 djm 3528: if (x11_saved_proto == NULL) {
3529: /* Save protocol name. */
3530: x11_saved_proto = xstrdup(proto);
3531: /*
1.221 djm 3532: * Extract real authentication data and generate fake data
1.219 djm 3533: * of the same length.
3534: */
3535: x11_saved_data = xmalloc(data_len);
3536: x11_fake_data = xmalloc(data_len);
3537: for (i = 0; i < data_len; i++) {
3538: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3539: fatal("x11_request_forwarding: bad "
3540: "authentication data: %.100s", data);
3541: if (i % 4 == 0)
3542: rnd = arc4random();
3543: x11_saved_data[i] = value;
3544: x11_fake_data[i] = rnd & 0xff;
3545: rnd >>= 8;
3546: }
3547: x11_saved_data_len = data_len;
3548: x11_fake_data_len = data_len;
1.25 markus 3549: }
3550:
3551: /* Convert the fake data into hex. */
1.219 djm 3552: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3553:
3554: /* Send the request packet. */
1.51 markus 3555: if (compat20) {
1.311 ! djm 3556: channel_request_start(client_session_id, "x11-req", want_reply);
1.51 markus 3557: packet_put_char(0); /* XXX bool single connection */
3558: } else {
3559: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3560: }
3561: packet_put_cstring(proto);
3562: packet_put_cstring(new_data);
1.25 markus 3563: packet_put_int(screen_number);
3564: packet_send();
3565: packet_write_wait();
3566: xfree(new_data);
1.1 deraadt 3567: }
3568:
1.121 markus 3569:
3570: /* -- agent forwarding */
3571:
1.1 deraadt 3572: /* Sends a message to the server to request authentication fd forwarding. */
3573:
1.49 markus 3574: void
1.142 itojun 3575: auth_request_forwarding(void)
1.1 deraadt 3576: {
1.25 markus 3577: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3578: packet_send();
3579: packet_write_wait();
1.1 deraadt 3580: }
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