Annotation of src/usr.bin/ssh/channels.c, Revision 1.302
1.302 ! djm 1: /* $OpenBSD: channels.c,v 1.301 2010/01/11 01:39:46 dtucker Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
1.265 deraadt 42: #include <sys/types.h>
1.234 stevesk 43: #include <sys/ioctl.h>
1.235 stevesk 44: #include <sys/un.h>
1.251 stevesk 45: #include <sys/socket.h>
1.261 stevesk 46: #include <sys/time.h>
1.275 djm 47: #include <sys/queue.h>
1.251 stevesk 48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.298 dtucker 53: #include <fcntl.h>
1.255 stevesk 54: #include <netdb.h>
1.263 stevesk 55: #include <stdio.h>
1.262 stevesk 56: #include <stdlib.h>
1.260 stevesk 57: #include <string.h>
1.233 stevesk 58: #include <termios.h>
1.256 stevesk 59: #include <unistd.h>
1.265 deraadt 60: #include <stdarg.h>
1.1 deraadt 61:
1.265 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.82 markus 64: #include "ssh1.h"
65: #include "ssh2.h"
1.1 deraadt 66: #include "packet.h"
1.82 markus 67: #include "log.h"
68: #include "misc.h"
1.265 deraadt 69: #include "buffer.h"
1.14 markus 70: #include "channels.h"
71: #include "compat.h"
1.82 markus 72: #include "canohost.h"
1.64 markus 73: #include "key.h"
74: #include "authfd.h"
1.147 stevesk 75: #include "pathnames.h"
1.1 deraadt 76:
1.121 markus 77: /* -- channel core */
1.12 markus 78:
1.27 markus 79: /*
80: * Pointer to an array containing all allocated channels. The array is
81: * dynamically extended as needed.
82: */
1.113 markus 83: static Channel **channels = NULL;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Size of the channel array. All slots of the array must always be
1.113 markus 87: * initialized (at least the type field); unused slots set to NULL
1.27 markus 88: */
1.209 avsm 89: static u_int channels_alloc = 0;
1.1 deraadt 90:
1.27 markus 91: /*
92: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 93: * updated in channel_new.
1.27 markus 94: */
1.84 markus 95: static int channel_max_fd = 0;
1.1 deraadt 96:
97:
1.121 markus 98: /* -- tcp forwarding */
1.1 deraadt 99:
1.27 markus 100: /*
101: * Data structure for storing which hosts are permitted for forward requests.
102: * The local sides of any remote forwards are stored in this array to prevent
103: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
104: * network (which might be behind a firewall).
105: */
1.25 markus 106: typedef struct {
1.41 markus 107: char *host_to_connect; /* Connect to 'host'. */
108: u_short port_to_connect; /* Connect to 'port'. */
109: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 110: } ForwardPermission;
111:
1.257 dtucker 112: /* List of all permitted host/port pairs to connect by the user. */
1.1 deraadt 113: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
116: static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
117:
118: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 119: static int num_permitted_opens = 0;
1.257 dtucker 120:
121: /* Number of permitted host/port pair in the array permitted by the admin. */
122: static int num_adm_permitted_opens = 0;
123:
1.27 markus 124: /*
125: * If this is true, all opens are permitted. This is the case on the server
126: * on which we have to trust the client anyway, and the user could do
127: * anything after logging in anyway.
128: */
1.1 deraadt 129: static int all_opens_permitted = 0;
130:
1.121 markus 131:
132: /* -- X11 forwarding */
133:
134: /* Maximum number of fake X11 displays to try. */
135: #define MAX_DISPLAYS 1000
136:
1.219 djm 137: /* Saved X11 local (client) display. */
138: static char *x11_saved_display = NULL;
139:
1.121 markus 140: /* Saved X11 authentication protocol name. */
141: static char *x11_saved_proto = NULL;
142:
143: /* Saved X11 authentication data. This is the real data. */
144: static char *x11_saved_data = NULL;
145: static u_int x11_saved_data_len = 0;
146:
147: /*
148: * Fake X11 authentication data. This is what the server will be sending us;
149: * we should replace any occurrences of this by the real data.
150: */
1.240 deraadt 151: static u_char *x11_fake_data = NULL;
1.121 markus 152: static u_int x11_fake_data_len;
153:
154:
155: /* -- agent forwarding */
156:
157: #define NUM_SOCKS 10
158:
1.82 markus 159: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 160: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 161:
1.121 markus 162: /* helper */
1.127 itojun 163: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 164:
1.276 djm 165: /* non-blocking connect helpers */
166: static int connect_next(struct channel_connect *);
167: static void channel_connect_ctx_free(struct channel_connect *);
168:
1.121 markus 169: /* -- channel core */
1.41 markus 170:
171: Channel *
1.229 markus 172: channel_by_id(int id)
1.41 markus 173: {
174: Channel *c;
1.113 markus 175:
1.209 avsm 176: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 177: logit("channel_by_id: %d: bad id", id);
1.41 markus 178: return NULL;
179: }
1.113 markus 180: c = channels[id];
181: if (c == NULL) {
1.229 markus 182: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 183: return NULL;
184: }
185: return c;
1.55 markus 186: }
187:
1.27 markus 188: /*
1.229 markus 189: * Returns the channel if it is allowed to receive protocol messages.
190: * Private channels, like listening sockets, may not receive messages.
191: */
192: Channel *
193: channel_lookup(int id)
194: {
195: Channel *c;
196:
197: if ((c = channel_by_id(id)) == NULL)
198: return (NULL);
199:
1.237 deraadt 200: switch (c->type) {
1.229 markus 201: case SSH_CHANNEL_X11_OPEN:
202: case SSH_CHANNEL_LARVAL:
203: case SSH_CHANNEL_CONNECTING:
204: case SSH_CHANNEL_DYNAMIC:
205: case SSH_CHANNEL_OPENING:
206: case SSH_CHANNEL_OPEN:
207: case SSH_CHANNEL_INPUT_DRAINING:
208: case SSH_CHANNEL_OUTPUT_DRAINING:
209: return (c);
210: }
211: logit("Non-public channel %d, type %d.", id, c->type);
212: return (NULL);
213: }
214:
215: /*
1.55 markus 216: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 217: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 218: */
1.127 itojun 219: static void
1.71 markus 220: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 221: int extusage, int nonblock, int is_tty)
1.1 deraadt 222: {
1.25 markus 223: /* Update the maximum file descriptor value. */
1.84 markus 224: channel_max_fd = MAX(channel_max_fd, rfd);
225: channel_max_fd = MAX(channel_max_fd, wfd);
226: channel_max_fd = MAX(channel_max_fd, efd);
227:
1.298 dtucker 228: if (rfd != -1)
229: fcntl(rfd, F_SETFD, FD_CLOEXEC);
230: if (wfd != -1 && wfd != rfd)
231: fcntl(wfd, F_SETFD, FD_CLOEXEC);
232: if (efd != -1 && efd != rfd && efd != wfd)
233: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 234:
1.52 markus 235: c->rfd = rfd;
236: c->wfd = wfd;
237: c->sock = (rfd == wfd) ? rfd : -1;
238: c->efd = efd;
239: c->extended_usage = extusage;
1.71 markus 240:
1.282 dtucker 241: if ((c->isatty = is_tty) != 0)
1.194 markus 242: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 243:
1.71 markus 244: /* enable nonblocking mode */
245: if (nonblock) {
246: if (rfd != -1)
247: set_nonblock(rfd);
248: if (wfd != -1)
249: set_nonblock(wfd);
250: if (efd != -1)
251: set_nonblock(efd);
252: }
1.52 markus 253: }
254:
255: /*
256: * Allocate a new channel object and set its type and socket. This will cause
257: * remote_name to be freed.
258: */
1.113 markus 259: Channel *
1.52 markus 260: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 261: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 262: {
1.209 avsm 263: int found;
264: u_int i;
1.52 markus 265: Channel *c;
1.25 markus 266:
267: /* Do initial allocation if this is the first call. */
268: if (channels_alloc == 0) {
269: channels_alloc = 10;
1.242 djm 270: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 271: for (i = 0; i < channels_alloc; i++)
1.113 markus 272: channels[i] = NULL;
1.25 markus 273: }
274: /* Try to find a free slot where to put the new channel. */
275: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 276: if (channels[i] == NULL) {
1.25 markus 277: /* Found a free slot. */
1.209 avsm 278: found = (int)i;
1.25 markus 279: break;
280: }
1.209 avsm 281: if (found < 0) {
1.27 markus 282: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 283: found = channels_alloc;
1.179 markus 284: if (channels_alloc > 10000)
285: fatal("channel_new: internal error: channels_alloc %d "
286: "too big.", channels_alloc);
1.243 djm 287: channels = xrealloc(channels, channels_alloc + 10,
288: sizeof(Channel *));
1.195 markus 289: channels_alloc += 10;
1.70 markus 290: debug2("channel: expanding %d", channels_alloc);
1.25 markus 291: for (i = found; i < channels_alloc; i++)
1.113 markus 292: channels[i] = NULL;
1.25 markus 293: }
1.113 markus 294: /* Initialize and return new channel. */
1.242 djm 295: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 296: buffer_init(&c->input);
297: buffer_init(&c->output);
1.41 markus 298: buffer_init(&c->extended);
1.293 djm 299: c->path = NULL;
1.159 markus 300: c->ostate = CHAN_OUTPUT_OPEN;
301: c->istate = CHAN_INPUT_OPEN;
302: c->flags = 0;
1.281 djm 303: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.25 markus 304: c->self = found;
305: c->type = type;
1.41 markus 306: c->ctype = ctype;
1.51 markus 307: c->local_window = window;
308: c->local_window_max = window;
309: c->local_consumed = 0;
310: c->local_maxpacket = maxpack;
1.25 markus 311: c->remote_id = -1;
1.190 markus 312: c->remote_name = xstrdup(remote_name);
1.41 markus 313: c->remote_window = 0;
314: c->remote_maxpacket = 0;
1.133 markus 315: c->force_drain = 0;
1.149 markus 316: c->single_connection = 0;
1.131 markus 317: c->detach_user = NULL;
1.225 djm 318: c->detach_close = 0;
1.275 djm 319: c->open_confirm = NULL;
320: c->open_confirm_ctx = NULL;
1.65 markus 321: c->input_filter = NULL;
1.231 reyk 322: c->output_filter = NULL;
1.280 djm 323: c->filter_ctx = NULL;
324: c->filter_cleanup = NULL;
1.302 ! djm 325: c->ctl_chan = -1;
! 326: c->mux_rcb = NULL;
! 327: c->mux_ctx = NULL;
1.299 markus 328: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 329: TAILQ_INIT(&c->status_confirms);
1.25 markus 330: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 331: return c;
1.1 deraadt 332: }
1.52 markus 333:
1.132 markus 334: static int
335: channel_find_maxfd(void)
336: {
1.209 avsm 337: u_int i;
338: int max = 0;
1.132 markus 339: Channel *c;
340:
341: for (i = 0; i < channels_alloc; i++) {
342: c = channels[i];
343: if (c != NULL) {
344: max = MAX(max, c->rfd);
345: max = MAX(max, c->wfd);
346: max = MAX(max, c->efd);
347: }
348: }
349: return max;
350: }
351:
352: int
353: channel_close_fd(int *fdp)
354: {
355: int ret = 0, fd = *fdp;
356:
357: if (fd != -1) {
358: ret = close(fd);
359: *fdp = -1;
360: if (fd == channel_max_fd)
361: channel_max_fd = channel_find_maxfd();
362: }
363: return ret;
364: }
365:
1.52 markus 366: /* Close all channel fd/socket. */
1.127 itojun 367: static void
1.52 markus 368: channel_close_fds(Channel *c)
369: {
1.302 ! djm 370: debug3("channel %d: close_fds r %d w %d e %d",
! 371: c->self, c->rfd, c->wfd, c->efd);
1.118 markus 372:
1.132 markus 373: channel_close_fd(&c->sock);
374: channel_close_fd(&c->rfd);
375: channel_close_fd(&c->wfd);
376: channel_close_fd(&c->efd);
1.121 markus 377: }
378:
379: /* Free the channel and close its fd/socket. */
380: void
381: channel_free(Channel *c)
382: {
383: char *s;
1.209 avsm 384: u_int i, n;
1.275 djm 385: struct channel_confirm *cc;
1.121 markus 386:
387: for (n = 0, i = 0; i < channels_alloc; i++)
388: if (channels[i])
389: n++;
1.209 avsm 390: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 391: c->remote_name ? c->remote_name : "???", n);
392:
393: s = channel_open_message();
1.194 markus 394: debug3("channel %d: status: %s", c->self, s);
1.121 markus 395: xfree(s);
396:
397: if (c->sock != -1)
398: shutdown(c->sock, SHUT_RDWR);
399: channel_close_fds(c);
400: buffer_free(&c->input);
401: buffer_free(&c->output);
402: buffer_free(&c->extended);
403: if (c->remote_name) {
404: xfree(c->remote_name);
405: c->remote_name = NULL;
406: }
1.293 djm 407: if (c->path) {
408: xfree(c->path);
409: c->path = NULL;
410: }
1.275 djm 411: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
412: if (cc->abandon_cb != NULL)
413: cc->abandon_cb(c, cc->ctx);
414: TAILQ_REMOVE(&c->status_confirms, cc, entry);
415: bzero(cc, sizeof(*cc));
416: xfree(cc);
417: }
1.280 djm 418: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
419: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 420: channels[c->self] = NULL;
421: xfree(c);
422: }
423:
424: void
1.126 markus 425: channel_free_all(void)
1.121 markus 426: {
1.209 avsm 427: u_int i;
1.121 markus 428:
1.126 markus 429: for (i = 0; i < channels_alloc; i++)
430: if (channels[i] != NULL)
431: channel_free(channels[i]);
1.131 markus 432: }
433:
1.121 markus 434: /*
435: * Closes the sockets/fds of all channels. This is used to close extra file
436: * descriptors after a fork.
437: */
438: void
1.142 itojun 439: channel_close_all(void)
1.121 markus 440: {
1.209 avsm 441: u_int i;
1.121 markus 442:
443: for (i = 0; i < channels_alloc; i++)
444: if (channels[i] != NULL)
445: channel_close_fds(channels[i]);
446: }
447:
448: /*
1.131 markus 449: * Stop listening to channels.
450: */
451: void
452: channel_stop_listening(void)
453: {
1.209 avsm 454: u_int i;
1.131 markus 455: Channel *c;
456:
457: for (i = 0; i < channels_alloc; i++) {
458: c = channels[i];
459: if (c != NULL) {
460: switch (c->type) {
461: case SSH_CHANNEL_AUTH_SOCKET:
462: case SSH_CHANNEL_PORT_LISTENER:
463: case SSH_CHANNEL_RPORT_LISTENER:
464: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 465: channel_close_fd(&c->sock);
1.131 markus 466: channel_free(c);
467: break;
468: }
469: }
470: }
471: }
472:
473: /*
1.121 markus 474: * Returns true if no channel has too much buffered data, and false if one or
475: * more channel is overfull.
476: */
477: int
1.142 itojun 478: channel_not_very_much_buffered_data(void)
1.121 markus 479: {
480: u_int i;
481: Channel *c;
482:
483: for (i = 0; i < channels_alloc; i++) {
484: c = channels[i];
485: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 486: #if 0
487: if (!compat20 &&
488: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 489: debug2("channel %d: big input buffer %d",
1.121 markus 490: c->self, buffer_len(&c->input));
491: return 0;
492: }
1.136 markus 493: #endif
1.121 markus 494: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 495: debug2("channel %d: big output buffer %u > %u",
1.136 markus 496: c->self, buffer_len(&c->output),
497: packet_get_maxsize());
1.121 markus 498: return 0;
499: }
500: }
501: }
502: return 1;
503: }
504:
505: /* Returns true if any channel is still open. */
506: int
1.142 itojun 507: channel_still_open(void)
1.121 markus 508: {
1.209 avsm 509: u_int i;
1.121 markus 510: Channel *c;
511:
512: for (i = 0; i < channels_alloc; i++) {
513: c = channels[i];
514: if (c == NULL)
515: continue;
516: switch (c->type) {
517: case SSH_CHANNEL_X11_LISTENER:
518: case SSH_CHANNEL_PORT_LISTENER:
519: case SSH_CHANNEL_RPORT_LISTENER:
1.302 ! djm 520: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 521: case SSH_CHANNEL_CLOSED:
522: case SSH_CHANNEL_AUTH_SOCKET:
523: case SSH_CHANNEL_DYNAMIC:
524: case SSH_CHANNEL_CONNECTING:
525: case SSH_CHANNEL_ZOMBIE:
526: continue;
527: case SSH_CHANNEL_LARVAL:
528: if (!compat20)
529: fatal("cannot happen: SSH_CHANNEL_LARVAL");
530: continue;
531: case SSH_CHANNEL_OPENING:
532: case SSH_CHANNEL_OPEN:
533: case SSH_CHANNEL_X11_OPEN:
1.302 ! djm 534: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 535: return 1;
536: case SSH_CHANNEL_INPUT_DRAINING:
537: case SSH_CHANNEL_OUTPUT_DRAINING:
538: if (!compat13)
539: fatal("cannot happen: OUT_DRAIN");
540: return 1;
541: default:
542: fatal("channel_still_open: bad channel type %d", c->type);
543: /* NOTREACHED */
544: }
545: }
546: return 0;
547: }
548:
549: /* Returns the id of an open channel suitable for keepaliving */
550: int
1.142 itojun 551: channel_find_open(void)
1.121 markus 552: {
1.209 avsm 553: u_int i;
1.121 markus 554: Channel *c;
555:
556: for (i = 0; i < channels_alloc; i++) {
557: c = channels[i];
1.206 djm 558: if (c == NULL || c->remote_id < 0)
1.121 markus 559: continue;
560: switch (c->type) {
561: case SSH_CHANNEL_CLOSED:
562: case SSH_CHANNEL_DYNAMIC:
563: case SSH_CHANNEL_X11_LISTENER:
564: case SSH_CHANNEL_PORT_LISTENER:
565: case SSH_CHANNEL_RPORT_LISTENER:
1.302 ! djm 566: case SSH_CHANNEL_MUX_LISTENER:
! 567: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 568: case SSH_CHANNEL_OPENING:
569: case SSH_CHANNEL_CONNECTING:
570: case SSH_CHANNEL_ZOMBIE:
571: continue;
572: case SSH_CHANNEL_LARVAL:
573: case SSH_CHANNEL_AUTH_SOCKET:
574: case SSH_CHANNEL_OPEN:
575: case SSH_CHANNEL_X11_OPEN:
576: return i;
577: case SSH_CHANNEL_INPUT_DRAINING:
578: case SSH_CHANNEL_OUTPUT_DRAINING:
579: if (!compat13)
580: fatal("cannot happen: OUT_DRAIN");
581: return i;
582: default:
583: fatal("channel_find_open: bad channel type %d", c->type);
584: /* NOTREACHED */
585: }
586: }
587: return -1;
588: }
589:
590:
591: /*
592: * Returns a message describing the currently open forwarded connections,
593: * suitable for sending to the client. The message contains crlf pairs for
594: * newlines.
595: */
596: char *
1.142 itojun 597: channel_open_message(void)
1.121 markus 598: {
599: Buffer buffer;
600: Channel *c;
601: char buf[1024], *cp;
1.209 avsm 602: u_int i;
1.121 markus 603:
604: buffer_init(&buffer);
605: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
606: buffer_append(&buffer, buf, strlen(buf));
607: for (i = 0; i < channels_alloc; i++) {
608: c = channels[i];
609: if (c == NULL)
610: continue;
611: switch (c->type) {
612: case SSH_CHANNEL_X11_LISTENER:
613: case SSH_CHANNEL_PORT_LISTENER:
614: case SSH_CHANNEL_RPORT_LISTENER:
615: case SSH_CHANNEL_CLOSED:
616: case SSH_CHANNEL_AUTH_SOCKET:
617: case SSH_CHANNEL_ZOMBIE:
1.302 ! djm 618: case SSH_CHANNEL_MUX_CLIENT:
! 619: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 620: continue;
621: case SSH_CHANNEL_LARVAL:
622: case SSH_CHANNEL_OPENING:
623: case SSH_CHANNEL_CONNECTING:
624: case SSH_CHANNEL_DYNAMIC:
625: case SSH_CHANNEL_OPEN:
626: case SSH_CHANNEL_X11_OPEN:
627: case SSH_CHANNEL_INPUT_DRAINING:
628: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 629: snprintf(buf, sizeof buf,
1.302 ! djm 630: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
1.121 markus 631: c->self, c->remote_name,
632: c->type, c->remote_id,
633: c->istate, buffer_len(&c->input),
634: c->ostate, buffer_len(&c->output),
1.302 ! djm 635: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 636: buffer_append(&buffer, buf, strlen(buf));
637: continue;
638: default:
639: fatal("channel_open_message: bad channel type %d", c->type);
640: /* NOTREACHED */
641: }
642: }
643: buffer_append(&buffer, "\0", 1);
644: cp = xstrdup(buffer_ptr(&buffer));
645: buffer_free(&buffer);
646: return cp;
647: }
648:
649: void
650: channel_send_open(int id)
651: {
652: Channel *c = channel_lookup(id);
1.180 deraadt 653:
1.121 markus 654: if (c == NULL) {
1.188 itojun 655: logit("channel_send_open: %d: bad id", id);
1.121 markus 656: return;
657: }
1.184 markus 658: debug2("channel %d: send open", id);
1.121 markus 659: packet_start(SSH2_MSG_CHANNEL_OPEN);
660: packet_put_cstring(c->ctype);
661: packet_put_int(c->self);
662: packet_put_int(c->local_window);
663: packet_put_int(c->local_maxpacket);
664: packet_send();
665: }
666:
667: void
1.184 markus 668: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 669: {
1.184 markus 670: Channel *c = channel_lookup(id);
1.180 deraadt 671:
1.121 markus 672: if (c == NULL) {
1.188 itojun 673: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 674: return;
675: }
1.204 djm 676: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 677: packet_start(SSH2_MSG_CHANNEL_REQUEST);
678: packet_put_int(c->remote_id);
679: packet_put_cstring(service);
680: packet_put_char(wantconfirm);
681: }
1.241 deraadt 682:
1.121 markus 683: void
1.275 djm 684: channel_register_status_confirm(int id, channel_confirm_cb *cb,
685: channel_confirm_abandon_cb *abandon_cb, void *ctx)
686: {
687: struct channel_confirm *cc;
688: Channel *c;
689:
690: if ((c = channel_lookup(id)) == NULL)
691: fatal("channel_register_expect: %d: bad id", id);
692:
693: cc = xmalloc(sizeof(*cc));
694: cc->cb = cb;
695: cc->abandon_cb = abandon_cb;
696: cc->ctx = ctx;
697: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
698: }
699:
700: void
701: channel_register_open_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 702: {
703: Channel *c = channel_lookup(id);
1.180 deraadt 704:
1.121 markus 705: if (c == NULL) {
1.287 stevesk 706: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 707: return;
708: }
1.275 djm 709: c->open_confirm = fn;
710: c->open_confirm_ctx = ctx;
1.121 markus 711: }
1.241 deraadt 712:
1.121 markus 713: void
1.225 djm 714: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 715: {
1.229 markus 716: Channel *c = channel_by_id(id);
1.180 deraadt 717:
1.121 markus 718: if (c == NULL) {
1.188 itojun 719: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 720: return;
721: }
1.131 markus 722: c->detach_user = fn;
1.225 djm 723: c->detach_close = do_close;
1.121 markus 724: }
1.241 deraadt 725:
1.121 markus 726: void
727: channel_cancel_cleanup(int id)
728: {
1.229 markus 729: Channel *c = channel_by_id(id);
1.180 deraadt 730:
1.121 markus 731: if (c == NULL) {
1.188 itojun 732: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 733: return;
1.52 markus 734: }
1.131 markus 735: c->detach_user = NULL;
1.225 djm 736: c->detach_close = 0;
1.121 markus 737: }
1.241 deraadt 738:
1.121 markus 739: void
1.231 reyk 740: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 741: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 742: {
743: Channel *c = channel_lookup(id);
1.180 deraadt 744:
1.121 markus 745: if (c == NULL) {
1.188 itojun 746: logit("channel_register_filter: %d: bad id", id);
1.121 markus 747: return;
1.52 markus 748: }
1.231 reyk 749: c->input_filter = ifn;
750: c->output_filter = ofn;
1.279 djm 751: c->filter_ctx = ctx;
1.280 djm 752: c->filter_cleanup = cfn;
1.52 markus 753: }
754:
1.49 markus 755: void
1.121 markus 756: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 757: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 758: {
1.121 markus 759: Channel *c = channel_lookup(id);
1.180 deraadt 760:
1.121 markus 761: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
762: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 763: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 764: c->type = SSH_CHANNEL_OPEN;
1.168 markus 765: c->local_window = c->local_window_max = window_max;
1.121 markus 766: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
767: packet_put_int(c->remote_id);
768: packet_put_int(c->local_window);
769: packet_send();
1.1 deraadt 770: }
771:
1.27 markus 772: /*
1.41 markus 773: * 'channel_pre*' are called just before select() to add any bits relevant to
774: * channels in the select bitmasks.
775: */
776: /*
777: * 'channel_post*': perform any appropriate operations for channels which
778: * have events pending.
1.27 markus 779: */
1.237 deraadt 780: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 781: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
782: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
783:
1.259 stevesk 784: /* ARGSUSED */
1.127 itojun 785: static void
1.237 deraadt 786: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 787: {
788: FD_SET(c->sock, readset);
789: }
790:
1.259 stevesk 791: /* ARGSUSED */
1.127 itojun 792: static void
1.237 deraadt 793: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 794: {
795: debug3("channel %d: waiting for connection", c->self);
796: FD_SET(c->sock, writeset);
797: }
798:
1.127 itojun 799: static void
1.237 deraadt 800: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 801: {
802: if (buffer_len(&c->input) < packet_get_maxsize())
803: FD_SET(c->sock, readset);
804: if (buffer_len(&c->output) > 0)
805: FD_SET(c->sock, writeset);
806: }
1.1 deraadt 807:
1.127 itojun 808: static void
1.237 deraadt 809: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 810: {
1.157 markus 811: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 812:
1.44 markus 813: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 814: limit > 0 &&
1.250 djm 815: buffer_len(&c->input) < limit &&
816: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 817: FD_SET(c->rfd, readset);
818: if (c->ostate == CHAN_OUTPUT_OPEN ||
819: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
820: if (buffer_len(&c->output) > 0) {
821: FD_SET(c->wfd, writeset);
822: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 823: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 824: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
825: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 826: else
827: chan_obuf_empty(c);
1.44 markus 828: }
829: }
830: /** XXX check close conditions, too */
1.277 markus 831: if (compat20 && c->efd != -1 &&
832: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 833: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
834: buffer_len(&c->extended) > 0)
835: FD_SET(c->efd, writeset);
1.172 markus 836: else if (!(c->flags & CHAN_EOF_SENT) &&
837: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 838: buffer_len(&c->extended) < c->remote_window)
839: FD_SET(c->efd, readset);
840: }
1.204 djm 841: /* XXX: What about efd? races? */
1.44 markus 842: }
843:
1.259 stevesk 844: /* ARGSUSED */
1.127 itojun 845: static void
1.237 deraadt 846: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 847: {
848: if (buffer_len(&c->input) == 0) {
849: packet_start(SSH_MSG_CHANNEL_CLOSE);
850: packet_put_int(c->remote_id);
851: packet_send();
852: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 853: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 854: }
855: }
856:
1.259 stevesk 857: /* ARGSUSED */
1.127 itojun 858: static void
1.237 deraadt 859: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 860: {
861: if (buffer_len(&c->output) == 0)
1.113 markus 862: chan_mark_dead(c);
1.49 markus 863: else
1.41 markus 864: FD_SET(c->sock, writeset);
865: }
866:
867: /*
868: * This is a special state for X11 authentication spoofing. An opened X11
869: * connection (when authentication spoofing is being done) remains in this
870: * state until the first packet has been completely read. The authentication
871: * data in that packet is then substituted by the real data if it matches the
872: * fake data, and the channel is put into normal mode.
1.51 markus 873: * XXX All this happens at the client side.
1.121 markus 874: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 875: */
1.127 itojun 876: static int
1.121 markus 877: x11_open_helper(Buffer *b)
1.1 deraadt 878: {
1.77 markus 879: u_char *ucp;
880: u_int proto_len, data_len;
1.25 markus 881:
1.41 markus 882: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 883: if (buffer_len(b) < 12)
1.41 markus 884: return 0;
885:
886: /* Parse the lengths of variable-length fields. */
1.155 stevesk 887: ucp = buffer_ptr(b);
1.41 markus 888: if (ucp[0] == 0x42) { /* Byte order MSB first. */
889: proto_len = 256 * ucp[6] + ucp[7];
890: data_len = 256 * ucp[8] + ucp[9];
891: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
892: proto_len = ucp[6] + 256 * ucp[7];
893: data_len = ucp[8] + 256 * ucp[9];
894: } else {
1.194 markus 895: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 896: ucp[0]);
1.41 markus 897: return -1;
898: }
899:
900: /* Check if the whole packet is in buffer. */
1.121 markus 901: if (buffer_len(b) <
1.41 markus 902: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
903: return 0;
904:
905: /* Check if authentication protocol matches. */
906: if (proto_len != strlen(x11_saved_proto) ||
907: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 908: debug2("X11 connection uses different authentication protocol.");
1.41 markus 909: return -1;
910: }
911: /* Check if authentication data matches our fake data. */
912: if (data_len != x11_fake_data_len ||
913: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
914: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 915: debug2("X11 auth data does not match fake data.");
1.41 markus 916: return -1;
917: }
918: /* Check fake data length */
919: if (x11_fake_data_len != x11_saved_data_len) {
920: error("X11 fake_data_len %d != saved_data_len %d",
921: x11_fake_data_len, x11_saved_data_len);
922: return -1;
923: }
924: /*
925: * Received authentication protocol and data match
926: * our fake data. Substitute the fake data with real
927: * data.
928: */
929: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
930: x11_saved_data, x11_saved_data_len);
931: return 1;
932: }
933:
1.127 itojun 934: static void
1.237 deraadt 935: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 936: {
1.121 markus 937: int ret = x11_open_helper(&c->output);
1.180 deraadt 938:
1.41 markus 939: if (ret == 1) {
940: /* Start normal processing for the channel. */
941: c->type = SSH_CHANNEL_OPEN;
1.47 markus 942: channel_pre_open_13(c, readset, writeset);
1.41 markus 943: } else if (ret == -1) {
944: /*
945: * We have received an X11 connection that has bad
946: * authentication information.
947: */
1.188 itojun 948: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 949: buffer_clear(&c->input);
950: buffer_clear(&c->output);
1.132 markus 951: channel_close_fd(&c->sock);
1.41 markus 952: c->sock = -1;
953: c->type = SSH_CHANNEL_CLOSED;
954: packet_start(SSH_MSG_CHANNEL_CLOSE);
955: packet_put_int(c->remote_id);
956: packet_send();
957: }
958: }
1.25 markus 959:
1.127 itojun 960: static void
1.237 deraadt 961: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 962: {
1.121 markus 963: int ret = x11_open_helper(&c->output);
1.133 markus 964:
965: /* c->force_drain = 1; */
966:
1.41 markus 967: if (ret == 1) {
968: c->type = SSH_CHANNEL_OPEN;
1.157 markus 969: channel_pre_open(c, readset, writeset);
1.41 markus 970: } else if (ret == -1) {
1.188 itojun 971: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 972: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 973: chan_read_failed(c);
974: buffer_clear(&c->input);
975: chan_ibuf_empty(c);
976: buffer_clear(&c->output);
977: /* for proto v1, the peer will send an IEOF */
978: if (compat20)
979: chan_write_failed(c);
980: else
981: c->type = SSH_CHANNEL_OPEN;
1.194 markus 982: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 983: }
984: }
1.25 markus 985:
1.302 ! djm 986: static void
! 987: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
! 988: {
! 989: if (c->istate == CHAN_INPUT_OPEN &&
! 990: buffer_check_alloc(&c->input, CHAN_RBUF))
! 991: FD_SET(c->rfd, readset);
! 992: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
! 993: /* clear buffer immediately (discard any partial packet) */
! 994: buffer_clear(&c->input);
! 995: chan_ibuf_empty(c);
! 996: /* Start output drain. XXX just kill chan? */
! 997: chan_rcvd_oclose(c);
! 998: }
! 999: if (c->ostate == CHAN_OUTPUT_OPEN ||
! 1000: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
! 1001: if (buffer_len(&c->output) > 0)
! 1002: FD_SET(c->wfd, writeset);
! 1003: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
! 1004: chan_obuf_empty(c);
! 1005: }
! 1006: }
! 1007:
1.104 markus 1008: /* try to decode a socks4 header */
1.259 stevesk 1009: /* ARGSUSED */
1.127 itojun 1010: static int
1.237 deraadt 1011: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1012: {
1.181 markus 1013: char *p, *host;
1.292 djm 1014: u_int len, have, i, found, need;
1.148 deraadt 1015: char username[256];
1.103 markus 1016: struct {
1017: u_int8_t version;
1018: u_int8_t command;
1019: u_int16_t dest_port;
1.104 markus 1020: struct in_addr dest_addr;
1.103 markus 1021: } s4_req, s4_rsp;
1022:
1.104 markus 1023: debug2("channel %d: decode socks4", c->self);
1.109 markus 1024:
1025: have = buffer_len(&c->input);
1026: len = sizeof(s4_req);
1027: if (have < len)
1028: return 0;
1029: p = buffer_ptr(&c->input);
1.292 djm 1030:
1031: need = 1;
1032: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1033: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1034: debug2("channel %d: socks4a request", c->self);
1035: /* ... and needs an extra string (the hostname) */
1036: need = 2;
1037: }
1038: /* Check for terminating NUL on the string(s) */
1.109 markus 1039: for (found = 0, i = len; i < have; i++) {
1040: if (p[i] == '\0') {
1.292 djm 1041: found++;
1042: if (found == need)
1043: break;
1.109 markus 1044: }
1045: if (i > 1024) {
1046: /* the peer is probably sending garbage */
1047: debug("channel %d: decode socks4: too long",
1048: c->self);
1049: return -1;
1050: }
1051: }
1.292 djm 1052: if (found < need)
1.109 markus 1053: return 0;
1.103 markus 1054: buffer_get(&c->input, (char *)&s4_req.version, 1);
1055: buffer_get(&c->input, (char *)&s4_req.command, 1);
1056: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1057: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1058: have = buffer_len(&c->input);
1.103 markus 1059: p = buffer_ptr(&c->input);
1060: len = strlen(p);
1.106 markus 1061: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1062: len++; /* trailing '\0' */
1.103 markus 1063: if (len > have)
1.104 markus 1064: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1065: c->self, len, have);
1066: strlcpy(username, p, sizeof(username));
1067: buffer_consume(&c->input, len);
1068:
1.293 djm 1069: if (c->path != NULL) {
1070: xfree(c->path);
1071: c->path = NULL;
1072: }
1.292 djm 1073: if (need == 1) { /* SOCKS4: one string */
1074: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1075: c->path = xstrdup(host);
1.292 djm 1076: } else { /* SOCKS4A: two strings */
1077: have = buffer_len(&c->input);
1078: p = buffer_ptr(&c->input);
1079: len = strlen(p);
1080: debug2("channel %d: decode socks4a: host %s/%d",
1081: c->self, p, len);
1082: len++; /* trailing '\0' */
1083: if (len > have)
1084: fatal("channel %d: decode socks4a: len %d > have %d",
1085: c->self, len, have);
1.293 djm 1086: if (len > NI_MAXHOST) {
1.292 djm 1087: error("channel %d: hostname \"%.100s\" too long",
1088: c->self, p);
1089: return -1;
1090: }
1.293 djm 1091: c->path = xstrdup(p);
1.292 djm 1092: buffer_consume(&c->input, len);
1093: }
1.103 markus 1094: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1095:
1.194 markus 1096: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1097: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1098:
1.104 markus 1099: if (s4_req.command != 1) {
1.292 djm 1100: debug("channel %d: cannot handle: %s cn %d",
1101: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1102: return -1;
1.103 markus 1103: }
1.104 markus 1104: s4_rsp.version = 0; /* vn: 0 for reply */
1105: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1106: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1107: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1108: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1109: return 1;
1110: }
1111:
1.193 markus 1112: /* try to decode a socks5 header */
1113: #define SSH_SOCKS5_AUTHDONE 0x1000
1114: #define SSH_SOCKS5_NOAUTH 0x00
1115: #define SSH_SOCKS5_IPV4 0x01
1116: #define SSH_SOCKS5_DOMAIN 0x03
1117: #define SSH_SOCKS5_IPV6 0x04
1118: #define SSH_SOCKS5_CONNECT 0x01
1119: #define SSH_SOCKS5_SUCCESS 0x00
1120:
1.259 stevesk 1121: /* ARGSUSED */
1.193 markus 1122: static int
1.237 deraadt 1123: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1124: {
1125: struct {
1126: u_int8_t version;
1127: u_int8_t command;
1128: u_int8_t reserved;
1129: u_int8_t atyp;
1130: } s5_req, s5_rsp;
1131: u_int16_t dest_port;
1.293 djm 1132: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1133: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1134:
1135: debug2("channel %d: decode socks5", c->self);
1136: p = buffer_ptr(&c->input);
1137: if (p[0] != 0x05)
1138: return -1;
1139: have = buffer_len(&c->input);
1140: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1141: /* format: ver | nmethods | methods */
1.198 djm 1142: if (have < 2)
1.193 markus 1143: return 0;
1144: nmethods = p[1];
1145: if (have < nmethods + 2)
1146: return 0;
1147: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1148: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1149: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1150: found = 1;
1151: break;
1152: }
1153: }
1154: if (!found) {
1155: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1156: c->self);
1157: return -1;
1158: }
1159: buffer_consume(&c->input, nmethods + 2);
1160: buffer_put_char(&c->output, 0x05); /* version */
1161: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1162: FD_SET(c->sock, writeset);
1163: c->flags |= SSH_SOCKS5_AUTHDONE;
1164: debug2("channel %d: socks5 auth done", c->self);
1165: return 0; /* need more */
1166: }
1167: debug2("channel %d: socks5 post auth", c->self);
1168: if (have < sizeof(s5_req)+1)
1169: return 0; /* need more */
1.247 deraadt 1170: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1171: if (s5_req.version != 0x05 ||
1172: s5_req.command != SSH_SOCKS5_CONNECT ||
1173: s5_req.reserved != 0x00) {
1.194 markus 1174: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1175: return -1;
1176: }
1.213 deraadt 1177: switch (s5_req.atyp){
1.193 markus 1178: case SSH_SOCKS5_IPV4:
1179: addrlen = 4;
1180: af = AF_INET;
1181: break;
1182: case SSH_SOCKS5_DOMAIN:
1183: addrlen = p[sizeof(s5_req)];
1184: af = -1;
1185: break;
1186: case SSH_SOCKS5_IPV6:
1187: addrlen = 16;
1188: af = AF_INET6;
1189: break;
1190: default:
1.194 markus 1191: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1192: return -1;
1193: }
1.252 djm 1194: need = sizeof(s5_req) + addrlen + 2;
1195: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1196: need++;
1197: if (have < need)
1.193 markus 1198: return 0;
1199: buffer_consume(&c->input, sizeof(s5_req));
1200: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1201: buffer_consume(&c->input, 1); /* host string length */
1202: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1203: buffer_get(&c->input, (char *)&dest_port, 2);
1204: dest_addr[addrlen] = '\0';
1.293 djm 1205: if (c->path != NULL) {
1206: xfree(c->path);
1207: c->path = NULL;
1208: }
1209: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1210: if (addrlen >= NI_MAXHOST) {
1.293 djm 1211: error("channel %d: dynamic request: socks5 hostname "
1212: "\"%.100s\" too long", c->self, dest_addr);
1213: return -1;
1214: }
1215: c->path = xstrdup(dest_addr);
1216: } else {
1217: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1218: return -1;
1219: c->path = xstrdup(ntop);
1220: }
1.193 markus 1221: c->host_port = ntohs(dest_port);
1.198 djm 1222:
1.194 markus 1223: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1224: c->self, c->path, c->host_port, s5_req.command);
1225:
1226: s5_rsp.version = 0x05;
1227: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1228: s5_rsp.reserved = 0; /* ignored */
1229: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1230: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1231: dest_port = 0; /* ignored */
1232:
1.246 deraadt 1233: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1234: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1235: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1236: return 1;
1.301 dtucker 1237: }
1238:
1239: Channel *
1.302 ! djm 1240: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
! 1241: int in, int out)
1.301 dtucker 1242: {
1243: Channel *c;
1244:
1245: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1246: port_to_connect);
1247:
1248: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1249: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1250: 0, "stdio-forward", /*nonblock*/0);
1251:
1252: c->path = xstrdup(host_to_connect);
1253: c->host_port = port_to_connect;
1254: c->listening_port = 0;
1255: c->force_drain = 1;
1256:
1257: channel_register_fds(c, in, out, -1, 0, 1, 0);
1258: port_open_helper(c, "direct-tcpip");
1259:
1260: return c;
1.193 markus 1261: }
1262:
1.104 markus 1263: /* dynamic port forwarding */
1.127 itojun 1264: static void
1.237 deraadt 1265: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1266: {
1267: u_char *p;
1.217 djm 1268: u_int have;
1269: int ret;
1.103 markus 1270:
1.104 markus 1271: have = buffer_len(&c->input);
1272: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1273: /* buffer_dump(&c->input); */
1.104 markus 1274: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1275: if (have < 3) {
1.104 markus 1276: /* need more */
1277: FD_SET(c->sock, readset);
1278: return;
1279: }
1280: /* try to guess the protocol */
1281: p = buffer_ptr(&c->input);
1282: switch (p[0]) {
1283: case 0x04:
1284: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1285: break;
1286: case 0x05:
1287: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1288: break;
1289: default:
1290: ret = -1;
1291: break;
1292: }
1293: if (ret < 0) {
1.113 markus 1294: chan_mark_dead(c);
1.104 markus 1295: } else if (ret == 0) {
1296: debug2("channel %d: pre_dynamic: need more", c->self);
1297: /* need more */
1298: FD_SET(c->sock, readset);
1299: } else {
1300: /* switch to the next state */
1301: c->type = SSH_CHANNEL_OPENING;
1302: port_open_helper(c, "direct-tcpip");
1303: }
1.103 markus 1304: }
1305:
1.41 markus 1306: /* This is our fake X11 server socket. */
1.259 stevesk 1307: /* ARGSUSED */
1.127 itojun 1308: static void
1.237 deraadt 1309: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1310: {
1.113 markus 1311: Channel *nc;
1.285 djm 1312: struct sockaddr_storage addr;
1.162 stevesk 1313: int newsock;
1.41 markus 1314: socklen_t addrlen;
1.85 markus 1315: char buf[16384], *remote_ipaddr;
1.51 markus 1316: int remote_port;
1.25 markus 1317:
1.41 markus 1318: if (FD_ISSET(c->sock, readset)) {
1319: debug("X11 connection requested.");
1320: addrlen = sizeof(addr);
1.285 djm 1321: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1322: if (c->single_connection) {
1.194 markus 1323: debug2("single_connection: closing X11 listener.");
1.149 markus 1324: channel_close_fd(&c->sock);
1325: chan_mark_dead(c);
1326: }
1.41 markus 1327: if (newsock < 0) {
1328: error("accept: %.100s", strerror(errno));
1329: return;
1330: }
1.162 stevesk 1331: set_nodelay(newsock);
1.85 markus 1332: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1333: remote_port = get_peer_port(newsock);
1.41 markus 1334: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1335: remote_ipaddr, remote_port);
1.51 markus 1336:
1.113 markus 1337: nc = channel_new("accepted x11 socket",
1.51 markus 1338: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1339: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1340: if (compat20) {
1341: packet_start(SSH2_MSG_CHANNEL_OPEN);
1342: packet_put_cstring("x11");
1.113 markus 1343: packet_put_int(nc->self);
1.149 markus 1344: packet_put_int(nc->local_window_max);
1345: packet_put_int(nc->local_maxpacket);
1.85 markus 1346: /* originator ipaddr and port */
1347: packet_put_cstring(remote_ipaddr);
1.57 markus 1348: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1349: debug2("ssh2 x11 bug compat mode");
1.57 markus 1350: } else {
1351: packet_put_int(remote_port);
1352: }
1.51 markus 1353: packet_send();
1354: } else {
1355: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1356: packet_put_int(nc->self);
1.121 markus 1357: if (packet_get_protocol_flags() &
1358: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1359: packet_put_cstring(buf);
1.51 markus 1360: packet_send();
1361: }
1.85 markus 1362: xfree(remote_ipaddr);
1.41 markus 1363: }
1364: }
1.25 markus 1365:
1.127 itojun 1366: static void
1.103 markus 1367: port_open_helper(Channel *c, char *rtype)
1368: {
1369: int direct;
1370: char buf[1024];
1371: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1372: int remote_port = get_peer_port(c->sock);
1.103 markus 1373:
1374: direct = (strcmp(rtype, "direct-tcpip") == 0);
1375:
1376: snprintf(buf, sizeof buf,
1377: "%s: listening port %d for %.100s port %d, "
1378: "connect from %.200s port %d",
1379: rtype, c->listening_port, c->path, c->host_port,
1380: remote_ipaddr, remote_port);
1381:
1382: xfree(c->remote_name);
1383: c->remote_name = xstrdup(buf);
1384:
1385: if (compat20) {
1386: packet_start(SSH2_MSG_CHANNEL_OPEN);
1387: packet_put_cstring(rtype);
1388: packet_put_int(c->self);
1389: packet_put_int(c->local_window_max);
1390: packet_put_int(c->local_maxpacket);
1391: if (direct) {
1392: /* target host, port */
1393: packet_put_cstring(c->path);
1394: packet_put_int(c->host_port);
1395: } else {
1396: /* listen address, port */
1397: packet_put_cstring(c->path);
1398: packet_put_int(c->listening_port);
1399: }
1400: /* originator host and port */
1401: packet_put_cstring(remote_ipaddr);
1.216 markus 1402: packet_put_int((u_int)remote_port);
1.103 markus 1403: packet_send();
1404: } else {
1405: packet_start(SSH_MSG_PORT_OPEN);
1406: packet_put_int(c->self);
1407: packet_put_cstring(c->path);
1408: packet_put_int(c->host_port);
1.121 markus 1409: if (packet_get_protocol_flags() &
1410: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1411: packet_put_cstring(c->remote_name);
1412: packet_send();
1413: }
1414: xfree(remote_ipaddr);
1415: }
1416:
1.226 djm 1417: static void
1418: channel_set_reuseaddr(int fd)
1419: {
1420: int on = 1;
1421:
1422: /*
1423: * Set socket options.
1424: * Allow local port reuse in TIME_WAIT.
1425: */
1426: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1427: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1428: }
1429:
1.41 markus 1430: /*
1431: * This socket is listening for connections to a forwarded TCP/IP port.
1432: */
1.259 stevesk 1433: /* ARGSUSED */
1.127 itojun 1434: static void
1.237 deraadt 1435: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1436: {
1.103 markus 1437: Channel *nc;
1.285 djm 1438: struct sockaddr_storage addr;
1.113 markus 1439: int newsock, nextstate;
1.41 markus 1440: socklen_t addrlen;
1.103 markus 1441: char *rtype;
1.73 markus 1442:
1.41 markus 1443: if (FD_ISSET(c->sock, readset)) {
1444: debug("Connection to port %d forwarding "
1445: "to %.100s port %d requested.",
1446: c->listening_port, c->path, c->host_port);
1.103 markus 1447:
1.137 markus 1448: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1449: nextstate = SSH_CHANNEL_OPENING;
1450: rtype = "forwarded-tcpip";
1451: } else {
1452: if (c->host_port == 0) {
1453: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1454: rtype = "dynamic-tcpip";
1.137 markus 1455: } else {
1456: nextstate = SSH_CHANNEL_OPENING;
1457: rtype = "direct-tcpip";
1458: }
1459: }
1.103 markus 1460:
1.41 markus 1461: addrlen = sizeof(addr);
1.285 djm 1462: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1463: if (newsock < 0) {
1464: error("accept: %.100s", strerror(errno));
1465: return;
1466: }
1.169 stevesk 1467: set_nodelay(newsock);
1.190 markus 1468: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1469: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1470: nc->listening_port = c->listening_port;
1471: nc->host_port = c->host_port;
1.293 djm 1472: if (c->path != NULL)
1473: nc->path = xstrdup(c->path);
1.103 markus 1474:
1.299 markus 1475: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1476: port_open_helper(nc, rtype);
1.41 markus 1477: }
1478: }
1.25 markus 1479:
1.41 markus 1480: /*
1481: * This is the authentication agent socket listening for connections from
1482: * clients.
1483: */
1.259 stevesk 1484: /* ARGSUSED */
1.127 itojun 1485: static void
1.237 deraadt 1486: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1487: {
1.113 markus 1488: Channel *nc;
1489: int newsock;
1.285 djm 1490: struct sockaddr_storage addr;
1.41 markus 1491: socklen_t addrlen;
1.25 markus 1492:
1.41 markus 1493: if (FD_ISSET(c->sock, readset)) {
1494: addrlen = sizeof(addr);
1.285 djm 1495: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1496: if (newsock < 0) {
1497: error("accept from auth socket: %.100s", strerror(errno));
1498: return;
1499: }
1.113 markus 1500: nc = channel_new("accepted auth socket",
1.73 markus 1501: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1502: c->local_window_max, c->local_maxpacket,
1.190 markus 1503: 0, "accepted auth socket", 1);
1.73 markus 1504: if (compat20) {
1505: packet_start(SSH2_MSG_CHANNEL_OPEN);
1506: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1507: packet_put_int(nc->self);
1.73 markus 1508: packet_put_int(c->local_window_max);
1509: packet_put_int(c->local_maxpacket);
1510: } else {
1511: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1512: packet_put_int(nc->self);
1.73 markus 1513: }
1.41 markus 1514: packet_send();
1515: }
1516: }
1.25 markus 1517:
1.259 stevesk 1518: /* ARGSUSED */
1.127 itojun 1519: static void
1.237 deraadt 1520: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1521: {
1.276 djm 1522: int err = 0, sock;
1.129 stevesk 1523: socklen_t sz = sizeof(err);
1.114 markus 1524:
1.75 markus 1525: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1526: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1527: err = errno;
1528: error("getsockopt SO_ERROR failed");
1529: }
1530: if (err == 0) {
1.276 djm 1531: debug("channel %d: connected to %s port %d",
1532: c->self, c->connect_ctx.host, c->connect_ctx.port);
1533: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1534: c->type = SSH_CHANNEL_OPEN;
1535: if (compat20) {
1536: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1537: packet_put_int(c->remote_id);
1538: packet_put_int(c->self);
1539: packet_put_int(c->local_window);
1540: packet_put_int(c->local_maxpacket);
1541: } else {
1542: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1543: packet_put_int(c->remote_id);
1544: packet_put_int(c->self);
1545: }
1.75 markus 1546: } else {
1.276 djm 1547: debug("channel %d: connection failed: %s",
1.114 markus 1548: c->self, strerror(err));
1.276 djm 1549: /* Try next address, if any */
1550: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1551: close(c->sock);
1552: c->sock = c->rfd = c->wfd = sock;
1553: channel_max_fd = channel_find_maxfd();
1554: return;
1555: }
1556: /* Exhausted all addresses */
1557: error("connect_to %.100s port %d: failed.",
1558: c->connect_ctx.host, c->connect_ctx.port);
1559: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1560: if (compat20) {
1561: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1562: packet_put_int(c->remote_id);
1563: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1564: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1565: packet_put_cstring(strerror(err));
1566: packet_put_cstring("");
1567: }
1.75 markus 1568: } else {
1.114 markus 1569: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1570: packet_put_int(c->remote_id);
1.75 markus 1571: }
1.114 markus 1572: chan_mark_dead(c);
1.75 markus 1573: }
1.114 markus 1574: packet_send();
1.75 markus 1575: }
1576: }
1577:
1.259 stevesk 1578: /* ARGSUSED */
1.127 itojun 1579: static int
1.237 deraadt 1580: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1581: {
1.214 markus 1582: char buf[CHAN_RBUF];
1.41 markus 1583: int len;
1.25 markus 1584:
1.118 markus 1585: if (c->rfd != -1 &&
1.41 markus 1586: FD_ISSET(c->rfd, readset)) {
1587: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1588: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1589: return 1;
1.41 markus 1590: if (len <= 0) {
1.194 markus 1591: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1592: c->self, c->rfd, len);
1.104 markus 1593: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1594: debug2("channel %d: not open", c->self);
1.113 markus 1595: chan_mark_dead(c);
1.103 markus 1596: return -1;
1.104 markus 1597: } else if (compat13) {
1.158 markus 1598: buffer_clear(&c->output);
1.41 markus 1599: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1600: debug2("channel %d: input draining.", c->self);
1.25 markus 1601: } else {
1.41 markus 1602: chan_read_failed(c);
1.25 markus 1603: }
1.41 markus 1604: return -1;
1605: }
1.143 deraadt 1606: if (c->input_filter != NULL) {
1.66 markus 1607: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1608: debug2("channel %d: filter stops", c->self);
1.65 markus 1609: chan_read_failed(c);
1610: }
1.228 reyk 1611: } else if (c->datagram) {
1612: buffer_put_string(&c->input, buf, len);
1.65 markus 1613: } else {
1614: buffer_append(&c->input, buf, len);
1615: }
1.41 markus 1616: }
1617: return 1;
1618: }
1.241 deraadt 1619:
1.259 stevesk 1620: /* ARGSUSED */
1.127 itojun 1621: static int
1.237 deraadt 1622: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1623: {
1.95 markus 1624: struct termios tio;
1.231 reyk 1625: u_char *data = NULL, *buf;
1.134 markus 1626: u_int dlen;
1.41 markus 1627: int len;
1.25 markus 1628:
1.41 markus 1629: /* Send buffered output data to the socket. */
1.118 markus 1630: if (c->wfd != -1 &&
1.41 markus 1631: FD_ISSET(c->wfd, writeset) &&
1632: buffer_len(&c->output) > 0) {
1.231 reyk 1633: if (c->output_filter != NULL) {
1634: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1635: debug2("channel %d: filter stops", c->self);
1.232 reyk 1636: if (c->type != SSH_CHANNEL_OPEN)
1637: chan_mark_dead(c);
1638: else
1639: chan_write_failed(c);
1640: return -1;
1.231 reyk 1641: }
1642: } else if (c->datagram) {
1643: buf = data = buffer_get_string(&c->output, &dlen);
1644: } else {
1645: buf = data = buffer_ptr(&c->output);
1646: dlen = buffer_len(&c->output);
1647: }
1648:
1.228 reyk 1649: if (c->datagram) {
1650: /* ignore truncated writes, datagrams might get lost */
1651: c->local_consumed += dlen + 4;
1.231 reyk 1652: len = write(c->wfd, buf, dlen);
1.228 reyk 1653: xfree(data);
1654: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1655: return 1;
1656: if (len <= 0) {
1657: if (c->type != SSH_CHANNEL_OPEN)
1658: chan_mark_dead(c);
1659: else
1660: chan_write_failed(c);
1661: return -1;
1662: }
1663: return 1;
1664: }
1.231 reyk 1665:
1666: len = write(c->wfd, buf, dlen);
1.53 markus 1667: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1668: return 1;
1.41 markus 1669: if (len <= 0) {
1.104 markus 1670: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1671: debug2("channel %d: not open", c->self);
1.113 markus 1672: chan_mark_dead(c);
1.104 markus 1673: return -1;
1674: } else if (compat13) {
1.158 markus 1675: buffer_clear(&c->output);
1.194 markus 1676: debug2("channel %d: input draining.", c->self);
1.41 markus 1677: c->type = SSH_CHANNEL_INPUT_DRAINING;
1678: } else {
1679: chan_write_failed(c);
1680: }
1681: return -1;
1.91 markus 1682: }
1.231 reyk 1683: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1684: if (tcgetattr(c->wfd, &tio) == 0 &&
1685: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1686: /*
1687: * Simulate echo to reduce the impact of
1.96 markus 1688: * traffic analysis. We need to match the
1.95 markus 1689: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1690: * (4 byte channel id + buf)
1.91 markus 1691: */
1.95 markus 1692: packet_send_ignore(4 + len);
1.91 markus 1693: packet_send();
1694: }
1.25 markus 1695: }
1.41 markus 1696: buffer_consume(&c->output, len);
1.44 markus 1697: if (compat20 && len > 0) {
1698: c->local_consumed += len;
1699: }
1700: }
1701: return 1;
1702: }
1.241 deraadt 1703:
1.127 itojun 1704: static int
1.237 deraadt 1705: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1706: {
1.214 markus 1707: char buf[CHAN_RBUF];
1.44 markus 1708: int len;
1709:
1.45 markus 1710: /** XXX handle drain efd, too */
1.44 markus 1711: if (c->efd != -1) {
1712: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1713: FD_ISSET(c->efd, writeset) &&
1714: buffer_len(&c->extended) > 0) {
1715: len = write(c->efd, buffer_ptr(&c->extended),
1716: buffer_len(&c->extended));
1.70 markus 1717: debug2("channel %d: written %d to efd %d",
1.44 markus 1718: c->self, len, c->efd);
1.93 markus 1719: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1720: return 1;
1721: if (len <= 0) {
1722: debug2("channel %d: closing write-efd %d",
1723: c->self, c->efd);
1.132 markus 1724: channel_close_fd(&c->efd);
1.93 markus 1725: } else {
1.44 markus 1726: buffer_consume(&c->extended, len);
1727: c->local_consumed += len;
1728: }
1729: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1730: FD_ISSET(c->efd, readset)) {
1731: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1732: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1733: c->self, len, c->efd);
1.93 markus 1734: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1735: return 1;
1736: if (len <= 0) {
1737: debug2("channel %d: closing read-efd %d",
1.45 markus 1738: c->self, c->efd);
1.132 markus 1739: channel_close_fd(&c->efd);
1.93 markus 1740: } else {
1.44 markus 1741: buffer_append(&c->extended, buf, len);
1.93 markus 1742: }
1.44 markus 1743: }
1744: }
1745: return 1;
1746: }
1.241 deraadt 1747:
1.259 stevesk 1748: /* ARGSUSED */
1.127 itojun 1749: static int
1.93 markus 1750: channel_check_window(Channel *c)
1.44 markus 1751: {
1.104 markus 1752: if (c->type == SSH_CHANNEL_OPEN &&
1753: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1754: ((c->local_window_max - c->local_window >
1.269 markus 1755: c->local_maxpacket*3) ||
1756: c->local_window < c->local_window_max/2) &&
1.44 markus 1757: c->local_consumed > 0) {
1758: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1759: packet_put_int(c->remote_id);
1760: packet_put_int(c->local_consumed);
1761: packet_send();
1.70 markus 1762: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1763: c->self, c->local_window,
1764: c->local_consumed);
1765: c->local_window += c->local_consumed;
1766: c->local_consumed = 0;
1.1 deraadt 1767: }
1.41 markus 1768: return 1;
1.1 deraadt 1769: }
1770:
1.127 itojun 1771: static void
1.237 deraadt 1772: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1773: {
1774: channel_handle_rfd(c, readset, writeset);
1775: channel_handle_wfd(c, readset, writeset);
1.157 markus 1776: if (!compat20)
1.137 markus 1777: return;
1.44 markus 1778: channel_handle_efd(c, readset, writeset);
1.93 markus 1779: channel_check_window(c);
1.44 markus 1780: }
1781:
1.302 ! djm 1782: static u_int
! 1783: read_mux(Channel *c, u_int need)
! 1784: {
! 1785: char buf[CHAN_RBUF];
! 1786: int len;
! 1787: u_int rlen;
! 1788:
! 1789: if (buffer_len(&c->input) < need) {
! 1790: rlen = need - buffer_len(&c->input);
! 1791: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
! 1792: if (len <= 0) {
! 1793: if (errno != EINTR && errno != EAGAIN) {
! 1794: debug2("channel %d: ctl read<=0 rfd %d len %d",
! 1795: c->self, c->rfd, len);
! 1796: chan_read_failed(c);
! 1797: return 0;
! 1798: }
! 1799: } else
! 1800: buffer_append(&c->input, buf, len);
! 1801: }
! 1802: return buffer_len(&c->input);
! 1803: }
! 1804:
! 1805: static void
! 1806: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
! 1807: {
! 1808: u_int need;
! 1809: ssize_t len;
! 1810:
! 1811: if (!compat20)
! 1812: fatal("%s: entered with !compat20", __func__);
! 1813:
! 1814: if (c->rfd != -1 && FD_ISSET(c->rfd, readset) &&
! 1815: (c->istate == CHAN_INPUT_OPEN ||
! 1816: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
! 1817: /*
! 1818: * Don't not read past the precise end of packets to
! 1819: * avoid disrupting fd passing.
! 1820: */
! 1821: if (read_mux(c, 4) < 4) /* read header */
! 1822: return;
! 1823: need = get_u32(buffer_ptr(&c->input));
! 1824: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
! 1825: if (need > CHANNEL_MUX_MAX_PACKET) {
! 1826: debug2("channel %d: packet too big %u > %u",
! 1827: c->self, CHANNEL_MUX_MAX_PACKET, need);
! 1828: chan_rcvd_oclose(c);
! 1829: return;
! 1830: }
! 1831: if (read_mux(c, need + 4) < need + 4) /* read body */
! 1832: return;
! 1833: if (c->mux_rcb(c) != 0) {
! 1834: debug("channel %d: mux_rcb failed", c->self);
! 1835: chan_mark_dead(c);
! 1836: return;
! 1837: }
! 1838: }
! 1839:
! 1840: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
! 1841: buffer_len(&c->output) > 0) {
! 1842: len = write(c->wfd, buffer_ptr(&c->output),
! 1843: buffer_len(&c->output));
! 1844: if (len < 0 && (errno == EINTR || errno == EAGAIN))
! 1845: return;
! 1846: if (len <= 0) {
! 1847: chan_mark_dead(c);
! 1848: return;
! 1849: }
! 1850: buffer_consume(&c->output, len);
! 1851: }
! 1852: }
! 1853:
! 1854: static void
! 1855: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
! 1856: {
! 1857: Channel *nc;
! 1858: struct sockaddr_storage addr;
! 1859: socklen_t addrlen;
! 1860: int newsock;
! 1861: uid_t euid;
! 1862: gid_t egid;
! 1863:
! 1864: if (!FD_ISSET(c->sock, readset))
! 1865: return;
! 1866:
! 1867: debug("multiplexing control connection");
! 1868:
! 1869: /*
! 1870: * Accept connection on control socket
! 1871: */
! 1872: memset(&addr, 0, sizeof(addr));
! 1873: addrlen = sizeof(addr);
! 1874: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
! 1875: &addrlen)) == -1) {
! 1876: error("%s accept: %s", __func__, strerror(errno));
! 1877: return;
! 1878: }
! 1879:
! 1880: if (getpeereid(newsock, &euid, &egid) < 0) {
! 1881: error("%s getpeereid failed: %s", __func__,
! 1882: strerror(errno));
! 1883: close(newsock);
! 1884: return;
! 1885: }
! 1886: if ((euid != 0) && (getuid() != euid)) {
! 1887: error("multiplex uid mismatch: peer euid %u != uid %u",
! 1888: (u_int)euid, (u_int)getuid());
! 1889: close(newsock);
! 1890: return;
! 1891: }
! 1892: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
! 1893: newsock, newsock, -1, c->local_window_max,
! 1894: c->local_maxpacket, 0, "mux-control", 1);
! 1895: nc->mux_rcb = c->mux_rcb;
! 1896: debug3("%s: new mux channel %d fd %d", __func__,
! 1897: nc->self, nc->sock);
! 1898: /* establish state */
! 1899: nc->mux_rcb(nc);
! 1900: /* mux state transitions must not elicit protocol messages */
! 1901: nc->flags |= CHAN_LOCAL;
! 1902: }
! 1903:
1.259 stevesk 1904: /* ARGSUSED */
1.127 itojun 1905: static void
1.237 deraadt 1906: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1907: {
1.41 markus 1908: int len;
1.180 deraadt 1909:
1.41 markus 1910: /* Send buffered output data to the socket. */
1911: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1912: len = write(c->sock, buffer_ptr(&c->output),
1913: buffer_len(&c->output));
1914: if (len <= 0)
1.158 markus 1915: buffer_clear(&c->output);
1.41 markus 1916: else
1917: buffer_consume(&c->output, len);
1918: }
1919: }
1.25 markus 1920:
1.127 itojun 1921: static void
1.44 markus 1922: channel_handler_init_20(void)
1923: {
1.157 markus 1924: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1925: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1926: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1927: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1928: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1929: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1930: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1931: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 ! djm 1932: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
! 1933: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1934:
1.157 markus 1935: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1936: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1937: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1938: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1939: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1940: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1941: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 ! djm 1942: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
! 1943: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1944: }
1945:
1.127 itojun 1946: static void
1.41 markus 1947: channel_handler_init_13(void)
1948: {
1949: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1950: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1951: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1952: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1953: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1954: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1955: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1956: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1957: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1958:
1.157 markus 1959: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1960: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1961: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1962: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1963: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1964: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1965: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1966: }
1.25 markus 1967:
1.127 itojun 1968: static void
1.41 markus 1969: channel_handler_init_15(void)
1970: {
1.157 markus 1971: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1972: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1973: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1974: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1975: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1976: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1977: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1978:
1.41 markus 1979: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1980: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1981: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1982: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1983: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1984: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1985: }
1.27 markus 1986:
1.127 itojun 1987: static void
1.41 markus 1988: channel_handler_init(void)
1989: {
1990: int i;
1.180 deraadt 1991:
1.148 deraadt 1992: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1993: channel_pre[i] = NULL;
1994: channel_post[i] = NULL;
1995: }
1.44 markus 1996: if (compat20)
1997: channel_handler_init_20();
1998: else if (compat13)
1.41 markus 1999: channel_handler_init_13();
2000: else
2001: channel_handler_init_15();
2002: }
1.25 markus 2003:
1.140 markus 2004: /* gc dead channels */
2005: static void
2006: channel_garbage_collect(Channel *c)
2007: {
2008: if (c == NULL)
2009: return;
2010: if (c->detach_user != NULL) {
1.225 djm 2011: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2012: return;
1.194 markus 2013: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2014: c->detach_user(c->self, NULL);
2015: /* if we still have a callback */
2016: if (c->detach_user != NULL)
2017: return;
1.194 markus 2018: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2019: }
2020: if (!chan_is_dead(c, 1))
2021: return;
1.194 markus 2022: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2023: channel_free(c);
2024: }
2025:
1.127 itojun 2026: static void
1.237 deraadt 2027: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 2028: {
2029: static int did_init = 0;
1.299 markus 2030: u_int i, oalloc;
1.41 markus 2031: Channel *c;
1.25 markus 2032:
1.41 markus 2033: if (!did_init) {
2034: channel_handler_init();
2035: did_init = 1;
2036: }
1.299 markus 2037: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2038: c = channels[i];
2039: if (c == NULL)
1.41 markus 2040: continue;
1.299 markus 2041: if (c->delayed) {
2042: if (ftab == channel_pre)
2043: c->delayed = 0;
2044: else
2045: continue;
2046: }
1.118 markus 2047: if (ftab[c->type] != NULL)
2048: (*ftab[c->type])(c, readset, writeset);
1.140 markus 2049: channel_garbage_collect(c);
1.1 deraadt 2050: }
2051: }
2052:
1.121 markus 2053: /*
2054: * Allocate/update select bitmasks and add any bits relevant to channels in
2055: * select bitmasks.
2056: */
1.49 markus 2057: void
1.100 markus 2058: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 2059: u_int *nallocp, int rekeying)
1.41 markus 2060: {
1.243 djm 2061: u_int n, sz, nfdset;
1.84 markus 2062:
2063: n = MAX(*maxfdp, channel_max_fd);
2064:
1.243 djm 2065: nfdset = howmany(n+1, NFDBITS);
2066: /* Explicitly test here, because xrealloc isn't always called */
2067: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2068: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2069: sz = nfdset * sizeof(fd_mask);
2070:
1.132 markus 2071: /* perhaps check sz < nalloc/2 and shrink? */
2072: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2073: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2074: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2075: *nallocp = sz;
1.84 markus 2076: }
1.132 markus 2077: *maxfdp = n;
1.84 markus 2078: memset(*readsetp, 0, sz);
2079: memset(*writesetp, 0, sz);
2080:
1.100 markus 2081: if (!rekeying)
2082: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 2083: }
2084:
1.121 markus 2085: /*
2086: * After select, perform any appropriate operations for channels which have
2087: * events pending.
2088: */
1.49 markus 2089: void
1.237 deraadt 2090: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2091: {
2092: channel_handler(channel_post, readset, writeset);
2093: }
2094:
1.121 markus 2095:
1.84 markus 2096: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2097: void
1.142 itojun 2098: channel_output_poll(void)
1.1 deraadt 2099: {
1.41 markus 2100: Channel *c;
1.209 avsm 2101: u_int i, len;
1.1 deraadt 2102:
1.25 markus 2103: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2104: c = channels[i];
2105: if (c == NULL)
2106: continue;
1.37 markus 2107:
1.121 markus 2108: /*
2109: * We are only interested in channels that can have buffered
2110: * incoming data.
2111: */
1.37 markus 2112: if (compat13) {
1.41 markus 2113: if (c->type != SSH_CHANNEL_OPEN &&
2114: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2115: continue;
2116: } else {
1.41 markus 2117: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2118: continue;
2119: }
1.46 markus 2120: if (compat20 &&
2121: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2122: /* XXX is this true? */
1.140 markus 2123: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2124: continue;
2125: }
1.25 markus 2126:
2127: /* Get the amount of buffered data for this channel. */
1.93 markus 2128: if ((c->istate == CHAN_INPUT_OPEN ||
2129: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2130: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2131: if (c->datagram) {
2132: if (len > 0) {
2133: u_char *data;
2134: u_int dlen;
2135:
2136: data = buffer_get_string(&c->input,
2137: &dlen);
2138: packet_start(SSH2_MSG_CHANNEL_DATA);
2139: packet_put_int(c->remote_id);
2140: packet_put_string(data, dlen);
2141: packet_send();
2142: c->remote_window -= dlen + 4;
2143: xfree(data);
2144: }
2145: continue;
2146: }
1.121 markus 2147: /*
2148: * Send some data for the other side over the secure
2149: * connection.
2150: */
1.44 markus 2151: if (compat20) {
2152: if (len > c->remote_window)
2153: len = c->remote_window;
2154: if (len > c->remote_maxpacket)
2155: len = c->remote_maxpacket;
1.25 markus 2156: } else {
1.44 markus 2157: if (packet_is_interactive()) {
2158: if (len > 1024)
2159: len = 512;
2160: } else {
2161: /* Keep the packets at reasonable size. */
2162: if (len > packet_get_maxsize()/2)
2163: len = packet_get_maxsize()/2;
2164: }
1.25 markus 2165: }
1.41 markus 2166: if (len > 0) {
1.44 markus 2167: packet_start(compat20 ?
2168: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2169: packet_put_int(c->remote_id);
2170: packet_put_string(buffer_ptr(&c->input), len);
2171: packet_send();
2172: buffer_consume(&c->input, len);
2173: c->remote_window -= len;
2174: }
2175: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2176: if (compat13)
2177: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2178: /*
2179: * input-buffer is empty and read-socket shutdown:
1.172 markus 2180: * tell peer, that we will not send more data: send IEOF.
2181: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2182: */
1.172 markus 2183: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2184: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2185: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2186: else
2187: chan_ibuf_empty(c);
1.25 markus 2188: }
1.44 markus 2189: /* Send extended data, i.e. stderr */
2190: if (compat20 &&
1.172 markus 2191: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2192: c->remote_window > 0 &&
2193: (len = buffer_len(&c->extended)) > 0 &&
2194: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2195: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2196: c->self, c->remote_window, buffer_len(&c->extended),
2197: c->extended_usage);
1.44 markus 2198: if (len > c->remote_window)
2199: len = c->remote_window;
2200: if (len > c->remote_maxpacket)
2201: len = c->remote_maxpacket;
2202: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2203: packet_put_int(c->remote_id);
2204: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2205: packet_put_string(buffer_ptr(&c->extended), len);
2206: packet_send();
2207: buffer_consume(&c->extended, len);
2208: c->remote_window -= len;
1.93 markus 2209: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2210: }
1.25 markus 2211: }
1.1 deraadt 2212: }
2213:
1.121 markus 2214:
2215: /* -- protocol input */
1.249 djm 2216:
2217: /* ARGSUSED */
1.49 markus 2218: void
1.154 markus 2219: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2220: {
1.37 markus 2221: int id;
1.25 markus 2222: char *data;
1.77 markus 2223: u_int data_len;
1.41 markus 2224: Channel *c;
1.25 markus 2225:
2226: /* Get the channel number and verify it. */
1.37 markus 2227: id = packet_get_int();
1.41 markus 2228: c = channel_lookup(id);
2229: if (c == NULL)
1.37 markus 2230: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2231:
2232: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2233: if (c->type != SSH_CHANNEL_OPEN &&
2234: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2235: return;
2236:
1.25 markus 2237: /* Get the data. */
1.274 markus 2238: data = packet_get_string_ptr(&data_len);
1.200 markus 2239:
2240: /*
2241: * Ignore data for protocol > 1.3 if output end is no longer open.
2242: * For protocol 2 the sending side is reducing its window as it sends
2243: * data, so we must 'fake' consumption of the data in order to ensure
2244: * that window updates are sent back. Otherwise the connection might
2245: * deadlock.
2246: */
2247: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2248: if (compat20) {
2249: c->local_window -= data_len;
2250: c->local_consumed += data_len;
2251: }
2252: return;
2253: }
1.41 markus 2254:
1.143 deraadt 2255: if (compat20) {
1.44 markus 2256: if (data_len > c->local_maxpacket) {
1.188 itojun 2257: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 2258: c->self, data_len, c->local_maxpacket);
2259: }
2260: if (data_len > c->local_window) {
1.188 itojun 2261: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 2262: c->self, data_len, c->local_window);
2263: return;
2264: }
2265: c->local_window -= data_len;
2266: }
1.228 reyk 2267: if (c->datagram)
2268: buffer_put_string(&c->output, data, data_len);
2269: else
2270: buffer_append(&c->output, data, data_len);
1.274 markus 2271: packet_check_eom();
1.1 deraadt 2272: }
1.121 markus 2273:
1.249 djm 2274: /* ARGSUSED */
1.49 markus 2275: void
1.154 markus 2276: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2277: {
2278: int id;
2279: char *data;
1.177 markus 2280: u_int data_len, tcode;
1.44 markus 2281: Channel *c;
2282:
2283: /* Get the channel number and verify it. */
2284: id = packet_get_int();
2285: c = channel_lookup(id);
2286:
2287: if (c == NULL)
2288: packet_disconnect("Received extended_data for bad channel %d.", id);
2289: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2290: logit("channel %d: ext data for non open", id);
1.44 markus 2291: return;
1.172 markus 2292: }
2293: if (c->flags & CHAN_EOF_RCVD) {
2294: if (datafellows & SSH_BUG_EXTEOF)
2295: debug("channel %d: accepting ext data after eof", id);
2296: else
2297: packet_disconnect("Received extended_data after EOF "
2298: "on channel %d.", id);
1.44 markus 2299: }
2300: tcode = packet_get_int();
2301: if (c->efd == -1 ||
2302: c->extended_usage != CHAN_EXTENDED_WRITE ||
2303: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2304: logit("channel %d: bad ext data", c->self);
1.44 markus 2305: return;
2306: }
2307: data = packet_get_string(&data_len);
1.152 markus 2308: packet_check_eom();
1.44 markus 2309: if (data_len > c->local_window) {
1.188 itojun 2310: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2311: c->self, data_len, c->local_window);
2312: xfree(data);
2313: return;
2314: }
1.70 markus 2315: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2316: c->local_window -= data_len;
2317: buffer_append(&c->extended, data, data_len);
2318: xfree(data);
2319: }
2320:
1.249 djm 2321: /* ARGSUSED */
1.49 markus 2322: void
1.154 markus 2323: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2324: {
2325: int id;
2326: Channel *c;
2327:
2328: id = packet_get_int();
1.152 markus 2329: packet_check_eom();
1.41 markus 2330: c = channel_lookup(id);
2331: if (c == NULL)
2332: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2333: chan_rcvd_ieof(c);
1.133 markus 2334:
2335: /* XXX force input close */
1.156 markus 2336: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2337: debug("channel %d: FORCE input drain", c->self);
2338: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2339: if (buffer_len(&c->input) == 0)
2340: chan_ibuf_empty(c);
1.133 markus 2341: }
2342:
1.41 markus 2343: }
1.1 deraadt 2344:
1.249 djm 2345: /* ARGSUSED */
1.49 markus 2346: void
1.154 markus 2347: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2348: {
1.41 markus 2349: int id;
2350: Channel *c;
1.1 deraadt 2351:
1.41 markus 2352: id = packet_get_int();
1.152 markus 2353: packet_check_eom();
1.41 markus 2354: c = channel_lookup(id);
2355: if (c == NULL)
2356: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2357:
2358: /*
2359: * Send a confirmation that we have closed the channel and no more
2360: * data is coming for it.
2361: */
1.25 markus 2362: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2363: packet_put_int(c->remote_id);
1.25 markus 2364: packet_send();
2365:
1.27 markus 2366: /*
2367: * If the channel is in closed state, we have sent a close request,
2368: * and the other side will eventually respond with a confirmation.
2369: * Thus, we cannot free the channel here, because then there would be
2370: * no-one to receive the confirmation. The channel gets freed when
2371: * the confirmation arrives.
2372: */
1.41 markus 2373: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2374: /*
2375: * Not a closed channel - mark it as draining, which will
2376: * cause it to be freed later.
2377: */
1.158 markus 2378: buffer_clear(&c->input);
1.41 markus 2379: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2380: }
1.1 deraadt 2381: }
2382:
1.41 markus 2383: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2384: /* ARGSUSED */
1.49 markus 2385: void
1.154 markus 2386: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2387: {
2388: int id = packet_get_int();
2389: Channel *c = channel_lookup(id);
1.151 markus 2390:
1.152 markus 2391: packet_check_eom();
1.41 markus 2392: if (c == NULL)
2393: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2394: chan_rcvd_oclose(c);
2395: }
1.1 deraadt 2396:
1.249 djm 2397: /* ARGSUSED */
1.49 markus 2398: void
1.154 markus 2399: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2400: {
1.41 markus 2401: int id = packet_get_int();
2402: Channel *c = channel_lookup(id);
1.1 deraadt 2403:
1.152 markus 2404: packet_check_eom();
1.41 markus 2405: if (c == NULL)
2406: packet_disconnect("Received close confirmation for "
2407: "out-of-range channel %d.", id);
2408: if (c->type != SSH_CHANNEL_CLOSED)
2409: packet_disconnect("Received close confirmation for "
2410: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2411: channel_free(c);
1.1 deraadt 2412: }
2413:
1.249 djm 2414: /* ARGSUSED */
1.49 markus 2415: void
1.154 markus 2416: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2417: {
1.41 markus 2418: int id, remote_id;
2419: Channel *c;
1.1 deraadt 2420:
1.41 markus 2421: id = packet_get_int();
2422: c = channel_lookup(id);
1.25 markus 2423:
1.41 markus 2424: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2425: packet_disconnect("Received open confirmation for "
2426: "non-opening channel %d.", id);
2427: remote_id = packet_get_int();
1.27 markus 2428: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2429: c->remote_id = remote_id;
2430: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2431:
2432: if (compat20) {
2433: c->remote_window = packet_get_int();
2434: c->remote_maxpacket = packet_get_int();
1.275 djm 2435: if (c->open_confirm) {
1.70 markus 2436: debug2("callback start");
1.275 djm 2437: c->open_confirm(c->self, c->open_confirm_ctx);
1.70 markus 2438: debug2("callback done");
1.44 markus 2439: }
1.194 markus 2440: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2441: c->remote_window, c->remote_maxpacket);
2442: }
1.152 markus 2443: packet_check_eom();
1.1 deraadt 2444: }
2445:
1.127 itojun 2446: static char *
1.114 markus 2447: reason2txt(int reason)
2448: {
1.143 deraadt 2449: switch (reason) {
1.114 markus 2450: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2451: return "administratively prohibited";
2452: case SSH2_OPEN_CONNECT_FAILED:
2453: return "connect failed";
2454: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2455: return "unknown channel type";
2456: case SSH2_OPEN_RESOURCE_SHORTAGE:
2457: return "resource shortage";
2458: }
1.117 stevesk 2459: return "unknown reason";
1.114 markus 2460: }
2461:
1.249 djm 2462: /* ARGSUSED */
1.49 markus 2463: void
1.154 markus 2464: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2465: {
1.86 markus 2466: int id, reason;
2467: char *msg = NULL, *lang = NULL;
1.41 markus 2468: Channel *c;
2469:
2470: id = packet_get_int();
2471: c = channel_lookup(id);
1.25 markus 2472:
1.41 markus 2473: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2474: packet_disconnect("Received open failure for "
2475: "non-opening channel %d.", id);
1.44 markus 2476: if (compat20) {
1.86 markus 2477: reason = packet_get_int();
1.110 markus 2478: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2479: msg = packet_get_string(NULL);
2480: lang = packet_get_string(NULL);
2481: }
1.188 itojun 2482: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2483: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2484: if (msg != NULL)
2485: xfree(msg);
2486: if (lang != NULL)
2487: xfree(lang);
1.44 markus 2488: }
1.152 markus 2489: packet_check_eom();
1.291 djm 2490: /* Schedule the channel for cleanup/deletion. */
2491: chan_mark_dead(c);
1.44 markus 2492: }
2493:
1.249 djm 2494: /* ARGSUSED */
1.121 markus 2495: void
1.154 markus 2496: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2497: {
2498: Channel *c;
1.178 markus 2499: int id;
2500: u_int adjust;
1.121 markus 2501:
2502: if (!compat20)
2503: return;
2504:
2505: /* Get the channel number and verify it. */
2506: id = packet_get_int();
2507: c = channel_lookup(id);
1.1 deraadt 2508:
1.229 markus 2509: if (c == NULL) {
2510: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2511: return;
2512: }
2513: adjust = packet_get_int();
1.152 markus 2514: packet_check_eom();
1.178 markus 2515: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2516: c->remote_window += adjust;
2517: }
1.1 deraadt 2518:
1.249 djm 2519: /* ARGSUSED */
1.121 markus 2520: void
1.154 markus 2521: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2522: {
1.121 markus 2523: Channel *c = NULL;
2524: u_short host_port;
2525: char *host, *originator_string;
1.276 djm 2526: int remote_id;
1.121 markus 2527:
2528: remote_id = packet_get_int();
2529: host = packet_get_string(NULL);
2530: host_port = packet_get_int();
1.25 markus 2531:
1.121 markus 2532: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2533: originator_string = packet_get_string(NULL);
2534: } else {
2535: originator_string = xstrdup("unknown (remote did not supply name)");
2536: }
1.152 markus 2537: packet_check_eom();
1.276 djm 2538: c = channel_connect_to(host, host_port,
2539: "connected socket", originator_string);
1.190 markus 2540: xfree(originator_string);
1.276 djm 2541: xfree(host);
1.121 markus 2542: if (c == NULL) {
2543: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2544: packet_put_int(remote_id);
2545: packet_send();
1.276 djm 2546: } else
2547: c->remote_id = remote_id;
1.1 deraadt 2548: }
2549:
1.275 djm 2550: /* ARGSUSED */
2551: void
2552: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2553: {
2554: Channel *c;
2555: struct channel_confirm *cc;
1.289 markus 2556: int id;
1.275 djm 2557:
2558: /* Reset keepalive timeout */
1.296 andreas 2559: packet_set_alive_timeouts(0);
1.275 djm 2560:
1.289 markus 2561: id = packet_get_int();
1.275 djm 2562: packet_check_eom();
2563:
1.289 markus 2564: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2565:
1.289 markus 2566: if ((c = channel_lookup(id)) == NULL) {
2567: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2568: return;
2569: }
2570: ;
2571: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2572: return;
2573: cc->cb(type, c, cc->ctx);
2574: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2575: bzero(cc, sizeof(*cc));
2576: xfree(cc);
2577: }
1.121 markus 2578:
2579: /* -- tcp forwarding */
1.135 markus 2580:
2581: void
2582: channel_set_af(int af)
2583: {
2584: IPv4or6 = af;
2585: }
1.121 markus 2586:
1.160 markus 2587: static int
1.295 djm 2588: channel_setup_fwd_listener(int type, const char *listen_addr,
2589: u_short listen_port, int *allocated_listen_port,
1.160 markus 2590: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2591: {
1.113 markus 2592: Channel *c;
1.226 djm 2593: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2594: struct addrinfo hints, *ai, *aitop;
1.212 djm 2595: const char *host, *addr;
1.35 markus 2596: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2597: in_port_t *lport_p;
1.25 markus 2598:
1.160 markus 2599: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2600: listen_addr : host_to_connect;
1.212 djm 2601: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2602:
1.160 markus 2603: if (host == NULL) {
2604: error("No forward host name.");
1.218 markus 2605: return 0;
1.73 markus 2606: }
1.294 djm 2607: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2608: error("Forward host name too long.");
1.218 markus 2609: return 0;
1.87 markus 2610: }
1.25 markus 2611:
1.28 markus 2612: /*
1.212 djm 2613: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2614: * specified address or wildcard. On the client, a specified bind
2615: * address will always override gateway_ports. On the server, a
2616: * gateway_ports of 1 (``yes'') will override the client's
2617: * specification and force a wildcard bind, whereas a value of 2
2618: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2619: * asked for.
2620: *
2621: * Special-case listen_addrs are:
2622: *
2623: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2624: * "" (empty string), "*" -> wildcard v4/v6
2625: * "localhost" -> loopback v4/v6
2626: */
2627: addr = NULL;
2628: if (listen_addr == NULL) {
2629: /* No address specified: default to gateway_ports setting */
2630: if (gateway_ports)
2631: wildcard = 1;
2632: } else if (gateway_ports || is_client) {
2633: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
1.272 djm 2634: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
1.212 djm 2635: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2636: (!is_client && gateway_ports == 1))
2637: wildcard = 1;
2638: else if (strcmp(listen_addr, "localhost") != 0)
2639: addr = listen_addr;
2640: }
2641:
2642: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2643: type, wildcard, (addr == NULL) ? "NULL" : addr);
2644:
2645: /*
1.35 markus 2646: * getaddrinfo returns a loopback address if the hostname is
2647: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2648: */
1.35 markus 2649: memset(&hints, 0, sizeof(hints));
2650: hints.ai_family = IPv4or6;
1.212 djm 2651: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2652: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2653: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2654: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2655: if (addr == NULL) {
2656: /* This really shouldn't happen */
2657: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2658: ssh_gai_strerror(r));
1.212 djm 2659: } else {
1.218 markus 2660: error("channel_setup_fwd_listener: "
1.271 dtucker 2661: "getaddrinfo(%.64s): %s", addr,
2662: ssh_gai_strerror(r));
1.212 djm 2663: }
1.218 markus 2664: return 0;
1.212 djm 2665: }
1.295 djm 2666: if (allocated_listen_port != NULL)
2667: *allocated_listen_port = 0;
1.35 markus 2668: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2669: switch (ai->ai_family) {
2670: case AF_INET:
2671: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2672: sin_port;
2673: break;
2674: case AF_INET6:
2675: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2676: sin6_port;
2677: break;
2678: default:
1.35 markus 2679: continue;
1.295 djm 2680: }
2681: /*
2682: * If allocating a port for -R forwards, then use the
2683: * same port for all address families.
2684: */
2685: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2686: allocated_listen_port != NULL && *allocated_listen_port > 0)
2687: *lport_p = htons(*allocated_listen_port);
2688:
1.35 markus 2689: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2690: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2691: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2692: continue;
2693: }
2694: /* Create a port to listen for the host. */
1.300 dtucker 2695: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2696: if (sock < 0) {
2697: /* this is no error since kernel may not support ipv6 */
2698: verbose("socket: %.100s", strerror(errno));
2699: continue;
2700: }
1.226 djm 2701:
2702: channel_set_reuseaddr(sock);
1.182 stevesk 2703:
1.295 djm 2704: debug("Local forwarding listening on %s port %s.",
2705: ntop, strport);
1.35 markus 2706:
2707: /* Bind the socket to the address. */
2708: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2709: /* address can be in use ipv6 address is already bound */
2710: verbose("bind: %.100s", strerror(errno));
2711: close(sock);
2712: continue;
2713: }
2714: /* Start listening for connections on the socket. */
1.199 markus 2715: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2716: error("listen: %.100s", strerror(errno));
2717: close(sock);
2718: continue;
2719: }
1.295 djm 2720:
2721: /*
2722: * listen_port == 0 requests a dynamically allocated port -
2723: * record what we got.
2724: */
2725: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2726: allocated_listen_port != NULL &&
2727: *allocated_listen_port == 0) {
2728: *allocated_listen_port = get_sock_port(sock, 1);
2729: debug("Allocated listen port %d",
2730: *allocated_listen_port);
2731: }
2732:
1.35 markus 2733: /* Allocate a channel number for the socket. */
1.121 markus 2734: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2735: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2736: 0, "port listener", 1);
1.293 djm 2737: c->path = xstrdup(host);
1.113 markus 2738: c->host_port = port_to_connect;
2739: c->listening_port = listen_port;
1.35 markus 2740: success = 1;
2741: }
2742: if (success == 0)
1.160 markus 2743: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2744: listen_port);
1.35 markus 2745: freeaddrinfo(aitop);
1.87 markus 2746: return success;
1.25 markus 2747: }
1.1 deraadt 2748:
1.202 djm 2749: int
2750: channel_cancel_rport_listener(const char *host, u_short port)
2751: {
1.209 avsm 2752: u_int i;
2753: int found = 0;
1.202 djm 2754:
1.213 deraadt 2755: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2756: Channel *c = channels[i];
2757:
2758: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
1.293 djm 2759: strcmp(c->path, host) == 0 && c->listening_port == port) {
1.210 djm 2760: debug2("%s: close channel %d", __func__, i);
1.202 djm 2761: channel_free(c);
2762: found = 1;
2763: }
2764: }
2765:
2766: return (found);
2767: }
2768:
1.160 markus 2769: /* protocol local port fwd, used by ssh (and sshd in v1) */
2770: int
1.212 djm 2771: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2772: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2773: {
2774: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2775: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2776: gateway_ports);
1.160 markus 2777: }
2778:
2779: /* protocol v2 remote port fwd, used by sshd */
2780: int
2781: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2782: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2783: {
2784: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2785: listen_address, listen_port, allocated_listen_port,
2786: NULL, 0, gateway_ports);
1.160 markus 2787: }
2788:
1.27 markus 2789: /*
2790: * Initiate forwarding of connections to port "port" on remote host through
2791: * the secure channel to host:port from local side.
2792: */
1.1 deraadt 2793:
1.253 markus 2794: int
1.212 djm 2795: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2796: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2797: {
1.153 markus 2798: int type, success = 0;
1.73 markus 2799:
1.25 markus 2800: /* Record locally that connection to this host/port is permitted. */
2801: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2802: fatal("channel_request_remote_forwarding: too many forwards");
2803:
2804: /* Send the forward request to the remote side. */
1.44 markus 2805: if (compat20) {
1.212 djm 2806: const char *address_to_bind;
1.267 djm 2807: if (listen_host == NULL) {
2808: if (datafellows & SSH_BUG_RFWD_ADDR)
2809: address_to_bind = "127.0.0.1";
2810: else
2811: address_to_bind = "localhost";
2812: } else if (*listen_host == '\0' ||
2813: strcmp(listen_host, "*") == 0) {
2814: if (datafellows & SSH_BUG_RFWD_ADDR)
2815: address_to_bind = "0.0.0.0";
2816: else
2817: address_to_bind = "";
2818: } else
1.212 djm 2819: address_to_bind = listen_host;
2820:
1.44 markus 2821: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2822: packet_put_cstring("tcpip-forward");
1.173 markus 2823: packet_put_char(1); /* boolean: want reply */
1.44 markus 2824: packet_put_cstring(address_to_bind);
2825: packet_put_int(listen_port);
1.73 markus 2826: packet_send();
2827: packet_write_wait();
2828: /* Assume that server accepts the request */
2829: success = 1;
1.44 markus 2830: } else {
2831: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2832: packet_put_int(listen_port);
2833: packet_put_cstring(host_to_connect);
1.44 markus 2834: packet_put_int(port_to_connect);
2835: packet_send();
2836: packet_write_wait();
1.73 markus 2837:
2838: /* Wait for response from the remote side. */
1.153 markus 2839: type = packet_read();
1.73 markus 2840: switch (type) {
2841: case SSH_SMSG_SUCCESS:
2842: success = 1;
2843: break;
2844: case SSH_SMSG_FAILURE:
2845: break;
2846: default:
2847: /* Unknown packet */
2848: packet_disconnect("Protocol error for port forward request:"
2849: "received packet type %d.", type);
2850: }
2851: }
2852: if (success) {
2853: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2854: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2855: permitted_opens[num_permitted_opens].listen_port = listen_port;
2856: num_permitted_opens++;
1.44 markus 2857: }
1.253 markus 2858: return (success ? 0 : -1);
1.1 deraadt 2859: }
2860:
1.27 markus 2861: /*
1.208 deraadt 2862: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2863: * local side.
2864: */
2865: void
1.212 djm 2866: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2867: {
2868: int i;
2869:
2870: if (!compat20)
2871: return;
2872:
2873: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2874: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2875: permitted_opens[i].listen_port == port)
2876: break;
2877: }
2878: if (i >= num_permitted_opens) {
2879: debug("%s: requested forward not found", __func__);
2880: return;
2881: }
2882: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2883: packet_put_cstring("cancel-tcpip-forward");
2884: packet_put_char(0);
1.212 djm 2885: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2886: packet_put_int(port);
2887: packet_send();
2888:
2889: permitted_opens[i].listen_port = 0;
2890: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2891: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2892: permitted_opens[i].host_to_connect = NULL;
2893: }
2894:
2895: /*
1.27 markus 2896: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2897: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2898: * message if there was an error).
1.27 markus 2899: */
1.253 markus 2900: int
1.56 markus 2901: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2902: {
1.31 markus 2903: u_short port, host_port;
1.253 markus 2904: int success = 0;
1.25 markus 2905: char *hostname;
1.1 deraadt 2906:
1.25 markus 2907: /* Get arguments from the packet. */
2908: port = packet_get_int();
2909: hostname = packet_get_string(NULL);
2910: host_port = packet_get_int();
2911:
1.27 markus 2912: /*
2913: * Check that an unprivileged user is not trying to forward a
2914: * privileged port.
2915: */
1.25 markus 2916: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2917: packet_disconnect(
2918: "Requested forwarding of port %d but user is not root.",
2919: port);
2920: if (host_port == 0)
2921: packet_disconnect("Dynamic forwarding denied.");
2922:
1.73 markus 2923: /* Initiate forwarding */
1.253 markus 2924: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2925: host_port, gateway_ports);
1.25 markus 2926:
2927: /* Free the argument string. */
2928: xfree(hostname);
1.253 markus 2929:
2930: return (success ? 0 : -1);
1.1 deraadt 2931: }
2932:
1.99 markus 2933: /*
2934: * Permits opening to any host/port if permitted_opens[] is empty. This is
2935: * usually called by the server, because the user could connect to any port
2936: * anyway, and the server has no way to know but to trust the client anyway.
2937: */
2938: void
1.142 itojun 2939: channel_permit_all_opens(void)
1.99 markus 2940: {
2941: if (num_permitted_opens == 0)
2942: all_opens_permitted = 1;
2943: }
2944:
1.101 markus 2945: void
1.99 markus 2946: channel_add_permitted_opens(char *host, int port)
2947: {
2948: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1.253 markus 2949: fatal("channel_add_permitted_opens: too many forwards");
1.99 markus 2950: debug("allow port forwarding to host %s port %d", host, port);
2951:
2952: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2953: permitted_opens[num_permitted_opens].port_to_connect = port;
2954: num_permitted_opens++;
2955:
2956: all_opens_permitted = 0;
2957: }
2958:
1.258 dtucker 2959: int
1.257 dtucker 2960: channel_add_adm_permitted_opens(char *host, int port)
2961: {
2962: if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2963: fatal("channel_add_adm_permitted_opens: too many forwards");
1.258 dtucker 2964: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 2965:
2966: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2967: = xstrdup(host);
2968: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 2969: return ++num_adm_permitted_opens;
1.257 dtucker 2970: }
2971:
2972: void
1.99 markus 2973: channel_clear_permitted_opens(void)
2974: {
2975: int i;
2976:
2977: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2978: if (permitted_opens[i].host_to_connect != NULL)
2979: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2980: num_permitted_opens = 0;
1.257 dtucker 2981: }
2982:
2983: void
2984: channel_clear_adm_permitted_opens(void)
2985: {
2986: int i;
1.99 markus 2987:
1.257 dtucker 2988: for (i = 0; i < num_adm_permitted_opens; i++)
2989: if (permitted_adm_opens[i].host_to_connect != NULL)
2990: xfree(permitted_adm_opens[i].host_to_connect);
2991: num_adm_permitted_opens = 0;
1.278 dtucker 2992: }
2993:
2994: void
2995: channel_print_adm_permitted_opens(void)
2996: {
1.286 djm 2997: int i;
1.278 dtucker 2998:
1.290 stevesk 2999: printf("permitopen");
1.288 stevesk 3000: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3001: printf(" any\n");
1.288 stevesk 3002: return;
3003: }
1.278 dtucker 3004: for (i = 0; i < num_adm_permitted_opens; i++)
3005: if (permitted_adm_opens[i].host_to_connect != NULL)
3006: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3007: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3008: printf("\n");
1.99 markus 3009: }
3010:
1.276 djm 3011: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3012: static int
1.276 djm 3013: connect_next(struct channel_connect *cctx)
1.41 markus 3014: {
1.276 djm 3015: int sock, saved_errno;
1.41 markus 3016: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3017:
1.276 djm 3018: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3019: if (cctx->ai->ai_family != AF_INET &&
3020: cctx->ai->ai_family != AF_INET6)
1.41 markus 3021: continue;
1.276 djm 3022: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3023: ntop, sizeof(ntop), strport, sizeof(strport),
3024: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3025: error("connect_next: getnameinfo failed");
1.41 markus 3026: continue;
3027: }
1.300 dtucker 3028: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3029: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3030: if (cctx->ai->ai_next == NULL)
1.186 djm 3031: error("socket: %.100s", strerror(errno));
3032: else
3033: verbose("socket: %.100s", strerror(errno));
1.41 markus 3034: continue;
3035: }
1.205 djm 3036: if (set_nonblock(sock) == -1)
3037: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3038: if (connect(sock, cctx->ai->ai_addr,
3039: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3040: debug("connect_next: host %.100s ([%.100s]:%s): "
3041: "%.100s", cctx->host, ntop, strport,
1.41 markus 3042: strerror(errno));
1.276 djm 3043: saved_errno = errno;
1.41 markus 3044: close(sock);
1.276 djm 3045: errno = saved_errno;
1.89 stevesk 3046: continue; /* fail -- try next */
1.41 markus 3047: }
1.276 djm 3048: debug("connect_next: host %.100s ([%.100s]:%s) "
3049: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3050: cctx->ai = cctx->ai->ai_next;
3051: set_nodelay(sock);
3052: return sock;
3053: }
3054: return -1;
3055: }
1.41 markus 3056:
1.276 djm 3057: static void
3058: channel_connect_ctx_free(struct channel_connect *cctx)
3059: {
3060: xfree(cctx->host);
3061: if (cctx->aitop)
3062: freeaddrinfo(cctx->aitop);
3063: bzero(cctx, sizeof(*cctx));
3064: cctx->host = NULL;
3065: cctx->ai = cctx->aitop = NULL;
3066: }
3067:
3068: /* Return CONNECTING channel to remote host, port */
3069: static Channel *
3070: connect_to(const char *host, u_short port, char *ctype, char *rname)
3071: {
3072: struct addrinfo hints;
3073: int gaierr;
3074: int sock = -1;
3075: char strport[NI_MAXSERV];
3076: struct channel_connect cctx;
3077: Channel *c;
3078:
1.284 djm 3079: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3080: memset(&hints, 0, sizeof(hints));
3081: hints.ai_family = IPv4or6;
3082: hints.ai_socktype = SOCK_STREAM;
3083: snprintf(strport, sizeof strport, "%d", port);
3084: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3085: error("connect_to %.100s: unknown host (%s)", host,
3086: ssh_gai_strerror(gaierr));
3087: return NULL;
1.41 markus 3088: }
1.276 djm 3089:
3090: cctx.host = xstrdup(host);
3091: cctx.port = port;
3092: cctx.ai = cctx.aitop;
3093:
3094: if ((sock = connect_next(&cctx)) == -1) {
3095: error("connect to %.100s port %d failed: %s",
3096: host, port, strerror(errno));
3097: channel_connect_ctx_free(&cctx);
3098: return NULL;
1.41 markus 3099: }
1.276 djm 3100: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3101: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3102: c->connect_ctx = cctx;
3103: return c;
1.41 markus 3104: }
1.99 markus 3105:
1.276 djm 3106: Channel *
3107: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3108: {
3109: int i;
1.99 markus 3110:
1.276 djm 3111: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3112: if (permitted_opens[i].host_to_connect != NULL &&
1.276 djm 3113: permitted_opens[i].listen_port == listen_port) {
1.99 markus 3114: return connect_to(
1.73 markus 3115: permitted_opens[i].host_to_connect,
1.276 djm 3116: permitted_opens[i].port_to_connect, ctype, rname);
3117: }
3118: }
1.74 markus 3119: error("WARNING: Server requests forwarding for unknown listen_port %d",
3120: listen_port);
1.276 djm 3121: return NULL;
1.73 markus 3122: }
3123:
1.99 markus 3124: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3125: Channel *
3126: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3127: {
1.257 dtucker 3128: int i, permit, permit_adm = 1;
1.99 markus 3129:
3130: permit = all_opens_permitted;
3131: if (!permit) {
3132: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3133: if (permitted_opens[i].host_to_connect != NULL &&
3134: permitted_opens[i].port_to_connect == port &&
1.99 markus 3135: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3136: permit = 1;
1.257 dtucker 3137: }
1.99 markus 3138:
1.257 dtucker 3139: if (num_adm_permitted_opens > 0) {
3140: permit_adm = 0;
3141: for (i = 0; i < num_adm_permitted_opens; i++)
3142: if (permitted_adm_opens[i].host_to_connect != NULL &&
3143: permitted_adm_opens[i].port_to_connect == port &&
3144: strcmp(permitted_adm_opens[i].host_to_connect, host)
3145: == 0)
3146: permit_adm = 1;
1.99 markus 3147: }
1.257 dtucker 3148:
3149: if (!permit || !permit_adm) {
1.188 itojun 3150: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3151: "but the request was denied.", host, port);
1.276 djm 3152: return NULL;
1.99 markus 3153: }
1.276 djm 3154: return connect_to(host, port, ctype, rname);
1.204 djm 3155: }
3156:
3157: void
3158: channel_send_window_changes(void)
3159: {
1.209 avsm 3160: u_int i;
1.204 djm 3161: struct winsize ws;
3162:
3163: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3164: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3165: channels[i]->type != SSH_CHANNEL_OPEN)
3166: continue;
3167: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3168: continue;
3169: channel_request_start(i, "window-change", 0);
1.238 deraadt 3170: packet_put_int((u_int)ws.ws_col);
3171: packet_put_int((u_int)ws.ws_row);
3172: packet_put_int((u_int)ws.ws_xpixel);
3173: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3174: packet_send();
3175: }
1.99 markus 3176: }
3177:
1.121 markus 3178: /* -- X11 forwarding */
1.1 deraadt 3179:
1.27 markus 3180: /*
3181: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3182: * Returns 0 and a suitable display number for the DISPLAY variable
3183: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3184: */
1.141 stevesk 3185: int
1.163 stevesk 3186: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3187: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3188: {
1.149 markus 3189: Channel *nc = NULL;
1.31 markus 3190: int display_number, sock;
3191: u_short port;
1.35 markus 3192: struct addrinfo hints, *ai, *aitop;
3193: char strport[NI_MAXSERV];
3194: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3195:
1.224 markus 3196: if (chanids == NULL)
3197: return -1;
3198:
1.33 markus 3199: for (display_number = x11_display_offset;
1.148 deraadt 3200: display_number < MAX_DISPLAYS;
3201: display_number++) {
1.25 markus 3202: port = 6000 + display_number;
1.35 markus 3203: memset(&hints, 0, sizeof(hints));
3204: hints.ai_family = IPv4or6;
1.163 stevesk 3205: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3206: hints.ai_socktype = SOCK_STREAM;
3207: snprintf(strport, sizeof strport, "%d", port);
3208: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3209: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3210: return -1;
1.25 markus 3211: }
1.35 markus 3212: for (ai = aitop; ai; ai = ai->ai_next) {
3213: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3214: continue;
1.300 dtucker 3215: sock = socket(ai->ai_family, ai->ai_socktype,
3216: ai->ai_protocol);
1.35 markus 3217: if (sock < 0) {
3218: error("socket: %.100s", strerror(errno));
1.203 markus 3219: freeaddrinfo(aitop);
1.141 stevesk 3220: return -1;
1.35 markus 3221: }
1.226 djm 3222: channel_set_reuseaddr(sock);
1.35 markus 3223: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3224: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3225: close(sock);
1.183 itojun 3226:
1.35 markus 3227: for (n = 0; n < num_socks; n++) {
3228: close(socks[n]);
3229: }
3230: num_socks = 0;
3231: break;
3232: }
3233: socks[num_socks++] = sock;
3234: if (num_socks == NUM_SOCKS)
3235: break;
1.25 markus 3236: }
1.83 stevesk 3237: freeaddrinfo(aitop);
1.35 markus 3238: if (num_socks > 0)
3239: break;
1.25 markus 3240: }
3241: if (display_number >= MAX_DISPLAYS) {
3242: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3243: return -1;
1.25 markus 3244: }
3245: /* Start listening for connections on the socket. */
1.35 markus 3246: for (n = 0; n < num_socks; n++) {
3247: sock = socks[n];
1.199 markus 3248: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3249: error("listen: %.100s", strerror(errno));
3250: close(sock);
1.141 stevesk 3251: return -1;
1.35 markus 3252: }
1.25 markus 3253: }
1.35 markus 3254:
3255: /* Allocate a channel for each socket. */
1.242 djm 3256: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3257: for (n = 0; n < num_socks; n++) {
3258: sock = socks[n];
1.149 markus 3259: nc = channel_new("x11 listener",
1.51 markus 3260: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3261: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3262: 0, "X11 inet listener", 1);
1.167 markus 3263: nc->single_connection = single_connection;
1.224 markus 3264: (*chanids)[n] = nc->self;
1.35 markus 3265: }
1.224 markus 3266: (*chanids)[n] = -1;
1.1 deraadt 3267:
1.141 stevesk 3268: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3269: *display_numberp = display_number;
3270: return (0);
1.1 deraadt 3271: }
3272:
1.127 itojun 3273: static int
1.77 markus 3274: connect_local_xsocket(u_int dnr)
1.1 deraadt 3275: {
1.25 markus 3276: int sock;
3277: struct sockaddr_un addr;
3278:
1.147 stevesk 3279: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3280: if (sock < 0)
3281: error("socket: %.100s", strerror(errno));
3282: memset(&addr, 0, sizeof(addr));
3283: addr.sun_family = AF_UNIX;
3284: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3285: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3286: return sock;
3287: close(sock);
1.25 markus 3288: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3289: return -1;
1.1 deraadt 3290: }
3291:
1.51 markus 3292: int
3293: x11_connect_display(void)
1.1 deraadt 3294: {
1.248 deraadt 3295: u_int display_number;
1.25 markus 3296: const char *display;
1.51 markus 3297: char buf[1024], *cp;
1.35 markus 3298: struct addrinfo hints, *ai, *aitop;
3299: char strport[NI_MAXSERV];
1.248 deraadt 3300: int gaierr, sock = 0;
1.25 markus 3301:
3302: /* Try to open a socket for the local X server. */
3303: display = getenv("DISPLAY");
3304: if (!display) {
3305: error("DISPLAY not set.");
1.51 markus 3306: return -1;
1.25 markus 3307: }
1.27 markus 3308: /*
3309: * Now we decode the value of the DISPLAY variable and make a
3310: * connection to the real X server.
3311: */
3312:
3313: /*
3314: * Check if it is a unix domain socket. Unix domain displays are in
3315: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3316: */
1.25 markus 3317: if (strncmp(display, "unix:", 5) == 0 ||
3318: display[0] == ':') {
3319: /* Connect to the unix domain socket. */
1.248 deraadt 3320: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3321: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3322: display);
1.51 markus 3323: return -1;
1.25 markus 3324: }
3325: /* Create a socket. */
3326: sock = connect_local_xsocket(display_number);
3327: if (sock < 0)
1.51 markus 3328: return -1;
1.25 markus 3329:
3330: /* OK, we now have a connection to the display. */
1.51 markus 3331: return sock;
1.25 markus 3332: }
1.27 markus 3333: /*
3334: * Connect to an inet socket. The DISPLAY value is supposedly
3335: * hostname:d[.s], where hostname may also be numeric IP address.
3336: */
1.145 stevesk 3337: strlcpy(buf, display, sizeof(buf));
1.25 markus 3338: cp = strchr(buf, ':');
3339: if (!cp) {
3340: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3341: return -1;
1.25 markus 3342: }
3343: *cp = 0;
1.27 markus 3344: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3345: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 3346: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3347: display);
1.51 markus 3348: return -1;
1.25 markus 3349: }
1.35 markus 3350:
3351: /* Look up the host address */
3352: memset(&hints, 0, sizeof(hints));
3353: hints.ai_family = IPv4or6;
3354: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3355: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3356: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3357: error("%.100s: unknown host. (%s)", buf,
3358: ssh_gai_strerror(gaierr));
1.51 markus 3359: return -1;
1.25 markus 3360: }
1.35 markus 3361: for (ai = aitop; ai; ai = ai->ai_next) {
3362: /* Create a socket. */
1.300 dtucker 3363: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3364: if (sock < 0) {
1.194 markus 3365: debug2("socket: %.100s", strerror(errno));
1.41 markus 3366: continue;
3367: }
3368: /* Connect it to the display. */
3369: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3370: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3371: 6000 + display_number, strerror(errno));
3372: close(sock);
3373: continue;
3374: }
3375: /* Success */
3376: break;
1.35 markus 3377: }
3378: freeaddrinfo(aitop);
3379: if (!ai) {
1.248 deraadt 3380: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3381: strerror(errno));
1.51 markus 3382: return -1;
1.25 markus 3383: }
1.162 stevesk 3384: set_nodelay(sock);
1.51 markus 3385: return sock;
3386: }
3387:
3388: /*
3389: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3390: * the remote channel number. We should do whatever we want, and respond
3391: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3392: */
3393:
1.259 stevesk 3394: /* ARGSUSED */
1.51 markus 3395: void
1.154 markus 3396: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3397: {
1.113 markus 3398: Channel *c = NULL;
3399: int remote_id, sock = 0;
1.51 markus 3400: char *remote_host;
1.25 markus 3401:
1.113 markus 3402: debug("Received X11 open request.");
1.51 markus 3403:
1.113 markus 3404: remote_id = packet_get_int();
1.121 markus 3405:
3406: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3407: remote_host = packet_get_string(NULL);
1.51 markus 3408: } else {
3409: remote_host = xstrdup("unknown (remote did not supply name)");
3410: }
1.152 markus 3411: packet_check_eom();
1.25 markus 3412:
1.51 markus 3413: /* Obtain a connection to the real X display. */
3414: sock = x11_connect_display();
1.113 markus 3415: if (sock != -1) {
3416: /* Allocate a channel for this connection. */
3417: c = channel_new("connected x11 socket",
3418: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3419: remote_host, 1);
1.167 markus 3420: c->remote_id = remote_id;
3421: c->force_drain = 1;
1.113 markus 3422: }
1.190 markus 3423: xfree(remote_host);
1.113 markus 3424: if (c == NULL) {
1.51 markus 3425: /* Send refusal to the remote host. */
3426: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3427: packet_put_int(remote_id);
1.51 markus 3428: } else {
3429: /* Send a confirmation to the remote host. */
3430: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3431: packet_put_int(remote_id);
3432: packet_put_int(c->self);
1.51 markus 3433: }
1.113 markus 3434: packet_send();
1.72 markus 3435: }
3436:
3437: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3438: /* ARGSUSED */
1.72 markus 3439: void
1.154 markus 3440: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3441: {
3442: int rchan = packet_get_int();
1.180 deraadt 3443:
1.143 deraadt 3444: switch (type) {
1.72 markus 3445: case SSH_SMSG_AGENT_OPEN:
3446: error("Warning: ssh server tried agent forwarding.");
3447: break;
3448: case SSH_SMSG_X11_OPEN:
3449: error("Warning: ssh server tried X11 forwarding.");
3450: break;
3451: default:
1.154 markus 3452: error("deny_input_open: type %d", type);
1.72 markus 3453: break;
3454: }
1.230 stevesk 3455: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3456: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3457: packet_put_int(rchan);
3458: packet_send();
1.1 deraadt 3459: }
3460:
1.27 markus 3461: /*
3462: * Requests forwarding of X11 connections, generates fake authentication
3463: * data, and enables authentication spoofing.
1.121 markus 3464: * This should be called in the client only.
1.27 markus 3465: */
1.49 markus 3466: void
1.215 djm 3467: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3468: const char *proto, const char *data)
1.1 deraadt 3469: {
1.77 markus 3470: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3471: u_int i, value;
1.25 markus 3472: char *new_data;
3473: int screen_number;
3474: const char *cp;
1.207 avsm 3475: u_int32_t rnd = 0;
1.25 markus 3476:
1.220 markus 3477: if (x11_saved_display == NULL)
3478: x11_saved_display = xstrdup(disp);
3479: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3480: error("x11_request_forwarding_with_spoofing: different "
3481: "$DISPLAY already forwarded");
3482: return;
3483: }
3484:
1.266 djm 3485: cp = strchr(disp, ':');
1.25 markus 3486: if (cp)
3487: cp = strchr(cp, '.');
3488: if (cp)
1.245 deraadt 3489: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3490: else
3491: screen_number = 0;
3492:
1.219 djm 3493: if (x11_saved_proto == NULL) {
3494: /* Save protocol name. */
3495: x11_saved_proto = xstrdup(proto);
3496: /*
1.221 djm 3497: * Extract real authentication data and generate fake data
1.219 djm 3498: * of the same length.
3499: */
3500: x11_saved_data = xmalloc(data_len);
3501: x11_fake_data = xmalloc(data_len);
3502: for (i = 0; i < data_len; i++) {
3503: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3504: fatal("x11_request_forwarding: bad "
3505: "authentication data: %.100s", data);
3506: if (i % 4 == 0)
3507: rnd = arc4random();
3508: x11_saved_data[i] = value;
3509: x11_fake_data[i] = rnd & 0xff;
3510: rnd >>= 8;
3511: }
3512: x11_saved_data_len = data_len;
3513: x11_fake_data_len = data_len;
1.25 markus 3514: }
3515:
3516: /* Convert the fake data into hex. */
1.219 djm 3517: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3518:
3519: /* Send the request packet. */
1.51 markus 3520: if (compat20) {
3521: channel_request_start(client_session_id, "x11-req", 0);
3522: packet_put_char(0); /* XXX bool single connection */
3523: } else {
3524: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3525: }
3526: packet_put_cstring(proto);
3527: packet_put_cstring(new_data);
1.25 markus 3528: packet_put_int(screen_number);
3529: packet_send();
3530: packet_write_wait();
3531: xfree(new_data);
1.1 deraadt 3532: }
3533:
1.121 markus 3534:
3535: /* -- agent forwarding */
3536:
1.1 deraadt 3537: /* Sends a message to the server to request authentication fd forwarding. */
3538:
1.49 markus 3539: void
1.142 itojun 3540: auth_request_forwarding(void)
1.1 deraadt 3541: {
1.25 markus 3542: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3543: packet_send();
3544: packet_write_wait();
1.1 deraadt 3545: }
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