Annotation of src/usr.bin/ssh/channels.c, Revision 1.249
1.249 ! djm 1: /* $OpenBSD: channels.c,v 1.248 2006/03/28 01:52:28 deraadt Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.234 stevesk 43:
44: #include <sys/ioctl.h>
1.235 stevesk 45: #include <sys/types.h>
46: #include <sys/un.h>
1.233 stevesk 47:
48: #include <termios.h>
1.1 deraadt 49:
50: #include "ssh.h"
1.82 markus 51: #include "ssh1.h"
52: #include "ssh2.h"
1.1 deraadt 53: #include "packet.h"
54: #include "xmalloc.h"
1.82 markus 55: #include "log.h"
56: #include "misc.h"
1.14 markus 57: #include "channels.h"
58: #include "compat.h"
1.82 markus 59: #include "canohost.h"
1.64 markus 60: #include "key.h"
61: #include "authfd.h"
1.147 stevesk 62: #include "pathnames.h"
1.193 markus 63: #include "bufaux.h"
1.1 deraadt 64:
1.121 markus 65: /* -- channel core */
1.12 markus 66:
1.27 markus 67: /*
68: * Pointer to an array containing all allocated channels. The array is
69: * dynamically extended as needed.
70: */
1.113 markus 71: static Channel **channels = NULL;
1.1 deraadt 72:
1.27 markus 73: /*
74: * Size of the channel array. All slots of the array must always be
1.113 markus 75: * initialized (at least the type field); unused slots set to NULL
1.27 markus 76: */
1.209 avsm 77: static u_int channels_alloc = 0;
1.1 deraadt 78:
1.27 markus 79: /*
80: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 81: * updated in channel_new.
1.27 markus 82: */
1.84 markus 83: static int channel_max_fd = 0;
1.1 deraadt 84:
85:
1.121 markus 86: /* -- tcp forwarding */
1.1 deraadt 87:
1.27 markus 88: /*
89: * Data structure for storing which hosts are permitted for forward requests.
90: * The local sides of any remote forwards are stored in this array to prevent
91: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
92: * network (which might be behind a firewall).
93: */
1.25 markus 94: typedef struct {
1.41 markus 95: char *host_to_connect; /* Connect to 'host'. */
96: u_short port_to_connect; /* Connect to 'port'. */
97: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 98: } ForwardPermission;
99:
100: /* List of all permitted host/port pairs to connect. */
101: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 102:
1.1 deraadt 103: /* Number of permitted host/port pairs in the array. */
104: static int num_permitted_opens = 0;
1.27 markus 105: /*
106: * If this is true, all opens are permitted. This is the case on the server
107: * on which we have to trust the client anyway, and the user could do
108: * anything after logging in anyway.
109: */
1.1 deraadt 110: static int all_opens_permitted = 0;
111:
1.121 markus 112:
113: /* -- X11 forwarding */
114:
115: /* Maximum number of fake X11 displays to try. */
116: #define MAX_DISPLAYS 1000
117:
1.219 djm 118: /* Saved X11 local (client) display. */
119: static char *x11_saved_display = NULL;
120:
1.121 markus 121: /* Saved X11 authentication protocol name. */
122: static char *x11_saved_proto = NULL;
123:
124: /* Saved X11 authentication data. This is the real data. */
125: static char *x11_saved_data = NULL;
126: static u_int x11_saved_data_len = 0;
127:
128: /*
129: * Fake X11 authentication data. This is what the server will be sending us;
130: * we should replace any occurrences of this by the real data.
131: */
1.240 deraadt 132: static u_char *x11_fake_data = NULL;
1.121 markus 133: static u_int x11_fake_data_len;
134:
135:
136: /* -- agent forwarding */
137:
138: #define NUM_SOCKS 10
139:
1.82 markus 140: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 141: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 142:
1.121 markus 143: /* helper */
1.127 itojun 144: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 145:
1.121 markus 146: /* -- channel core */
1.41 markus 147:
148: Channel *
1.229 markus 149: channel_by_id(int id)
1.41 markus 150: {
151: Channel *c;
1.113 markus 152:
1.209 avsm 153: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 154: logit("channel_by_id: %d: bad id", id);
1.41 markus 155: return NULL;
156: }
1.113 markus 157: c = channels[id];
158: if (c == NULL) {
1.229 markus 159: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 160: return NULL;
161: }
162: return c;
1.55 markus 163: }
164:
1.27 markus 165: /*
1.229 markus 166: * Returns the channel if it is allowed to receive protocol messages.
167: * Private channels, like listening sockets, may not receive messages.
168: */
169: Channel *
170: channel_lookup(int id)
171: {
172: Channel *c;
173:
174: if ((c = channel_by_id(id)) == NULL)
175: return (NULL);
176:
1.237 deraadt 177: switch (c->type) {
1.229 markus 178: case SSH_CHANNEL_X11_OPEN:
179: case SSH_CHANNEL_LARVAL:
180: case SSH_CHANNEL_CONNECTING:
181: case SSH_CHANNEL_DYNAMIC:
182: case SSH_CHANNEL_OPENING:
183: case SSH_CHANNEL_OPEN:
184: case SSH_CHANNEL_INPUT_DRAINING:
185: case SSH_CHANNEL_OUTPUT_DRAINING:
186: return (c);
187: }
188: logit("Non-public channel %d, type %d.", id, c->type);
189: return (NULL);
190: }
191:
192: /*
1.55 markus 193: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 194: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 195: */
1.127 itojun 196: static void
1.71 markus 197: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
198: int extusage, int nonblock)
1.1 deraadt 199: {
1.25 markus 200: /* Update the maximum file descriptor value. */
1.84 markus 201: channel_max_fd = MAX(channel_max_fd, rfd);
202: channel_max_fd = MAX(channel_max_fd, wfd);
203: channel_max_fd = MAX(channel_max_fd, efd);
204:
1.27 markus 205: /* XXX set close-on-exec -markus */
1.55 markus 206:
1.52 markus 207: c->rfd = rfd;
208: c->wfd = wfd;
209: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 210: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 211: c->efd = efd;
212: c->extended_usage = extusage;
1.71 markus 213:
1.91 markus 214: /* XXX ugly hack: nonblock is only set by the server */
215: if (nonblock && isatty(c->rfd)) {
1.194 markus 216: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 217: c->isatty = 1;
218: if (!isatty(c->wfd)) {
1.94 markus 219: error("channel %d: wfd %d is not a tty?",
1.91 markus 220: c->self, c->wfd);
221: }
222: } else {
223: c->isatty = 0;
224: }
225:
1.71 markus 226: /* enable nonblocking mode */
227: if (nonblock) {
228: if (rfd != -1)
229: set_nonblock(rfd);
230: if (wfd != -1)
231: set_nonblock(wfd);
232: if (efd != -1)
233: set_nonblock(efd);
234: }
1.52 markus 235: }
236:
237: /*
238: * Allocate a new channel object and set its type and socket. This will cause
239: * remote_name to be freed.
240: */
1.113 markus 241: Channel *
1.52 markus 242: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 243: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 244: {
1.209 avsm 245: int found;
246: u_int i;
1.52 markus 247: Channel *c;
1.25 markus 248:
249: /* Do initial allocation if this is the first call. */
250: if (channels_alloc == 0) {
251: channels_alloc = 10;
1.242 djm 252: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 253: for (i = 0; i < channels_alloc; i++)
1.113 markus 254: channels[i] = NULL;
1.25 markus 255: }
256: /* Try to find a free slot where to put the new channel. */
257: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 258: if (channels[i] == NULL) {
1.25 markus 259: /* Found a free slot. */
1.209 avsm 260: found = (int)i;
1.25 markus 261: break;
262: }
1.209 avsm 263: if (found < 0) {
1.27 markus 264: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 265: found = channels_alloc;
1.179 markus 266: if (channels_alloc > 10000)
267: fatal("channel_new: internal error: channels_alloc %d "
268: "too big.", channels_alloc);
1.243 djm 269: channels = xrealloc(channels, channels_alloc + 10,
270: sizeof(Channel *));
1.195 markus 271: channels_alloc += 10;
1.70 markus 272: debug2("channel: expanding %d", channels_alloc);
1.25 markus 273: for (i = found; i < channels_alloc; i++)
1.113 markus 274: channels[i] = NULL;
1.25 markus 275: }
1.113 markus 276: /* Initialize and return new channel. */
1.242 djm 277: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 278: buffer_init(&c->input);
279: buffer_init(&c->output);
1.41 markus 280: buffer_init(&c->extended);
1.159 markus 281: c->ostate = CHAN_OUTPUT_OPEN;
282: c->istate = CHAN_INPUT_OPEN;
283: c->flags = 0;
1.71 markus 284: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 285: c->self = found;
286: c->type = type;
1.41 markus 287: c->ctype = ctype;
1.51 markus 288: c->local_window = window;
289: c->local_window_max = window;
290: c->local_consumed = 0;
291: c->local_maxpacket = maxpack;
1.25 markus 292: c->remote_id = -1;
1.190 markus 293: c->remote_name = xstrdup(remote_name);
1.41 markus 294: c->remote_window = 0;
295: c->remote_maxpacket = 0;
1.133 markus 296: c->force_drain = 0;
1.149 markus 297: c->single_connection = 0;
1.131 markus 298: c->detach_user = NULL;
1.225 djm 299: c->detach_close = 0;
1.165 markus 300: c->confirm = NULL;
1.204 djm 301: c->confirm_ctx = NULL;
1.65 markus 302: c->input_filter = NULL;
1.231 reyk 303: c->output_filter = NULL;
1.25 markus 304: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 305: return c;
1.1 deraadt 306: }
1.52 markus 307:
1.132 markus 308: static int
309: channel_find_maxfd(void)
310: {
1.209 avsm 311: u_int i;
312: int max = 0;
1.132 markus 313: Channel *c;
314:
315: for (i = 0; i < channels_alloc; i++) {
316: c = channels[i];
317: if (c != NULL) {
318: max = MAX(max, c->rfd);
319: max = MAX(max, c->wfd);
320: max = MAX(max, c->efd);
321: }
322: }
323: return max;
324: }
325:
326: int
327: channel_close_fd(int *fdp)
328: {
329: int ret = 0, fd = *fdp;
330:
331: if (fd != -1) {
332: ret = close(fd);
333: *fdp = -1;
334: if (fd == channel_max_fd)
335: channel_max_fd = channel_find_maxfd();
336: }
337: return ret;
338: }
339:
1.52 markus 340: /* Close all channel fd/socket. */
1.127 itojun 341: static void
1.52 markus 342: channel_close_fds(Channel *c)
343: {
1.204 djm 344: debug3("channel %d: close_fds r %d w %d e %d c %d",
345: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 346:
1.132 markus 347: channel_close_fd(&c->sock);
1.204 djm 348: channel_close_fd(&c->ctl_fd);
1.132 markus 349: channel_close_fd(&c->rfd);
350: channel_close_fd(&c->wfd);
351: channel_close_fd(&c->efd);
1.121 markus 352: }
353:
354: /* Free the channel and close its fd/socket. */
355: void
356: channel_free(Channel *c)
357: {
358: char *s;
1.209 avsm 359: u_int i, n;
1.121 markus 360:
361: for (n = 0, i = 0; i < channels_alloc; i++)
362: if (channels[i])
363: n++;
1.209 avsm 364: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 365: c->remote_name ? c->remote_name : "???", n);
366:
367: s = channel_open_message();
1.194 markus 368: debug3("channel %d: status: %s", c->self, s);
1.121 markus 369: xfree(s);
370:
371: if (c->sock != -1)
372: shutdown(c->sock, SHUT_RDWR);
1.204 djm 373: if (c->ctl_fd != -1)
374: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 375: channel_close_fds(c);
376: buffer_free(&c->input);
377: buffer_free(&c->output);
378: buffer_free(&c->extended);
379: if (c->remote_name) {
380: xfree(c->remote_name);
381: c->remote_name = NULL;
382: }
383: channels[c->self] = NULL;
384: xfree(c);
385: }
386:
387: void
1.126 markus 388: channel_free_all(void)
1.121 markus 389: {
1.209 avsm 390: u_int i;
1.121 markus 391:
1.126 markus 392: for (i = 0; i < channels_alloc; i++)
393: if (channels[i] != NULL)
394: channel_free(channels[i]);
1.131 markus 395: }
396:
1.121 markus 397: /*
398: * Closes the sockets/fds of all channels. This is used to close extra file
399: * descriptors after a fork.
400: */
401: void
1.142 itojun 402: channel_close_all(void)
1.121 markus 403: {
1.209 avsm 404: u_int i;
1.121 markus 405:
406: for (i = 0; i < channels_alloc; i++)
407: if (channels[i] != NULL)
408: channel_close_fds(channels[i]);
409: }
410:
411: /*
1.131 markus 412: * Stop listening to channels.
413: */
414: void
415: channel_stop_listening(void)
416: {
1.209 avsm 417: u_int i;
1.131 markus 418: Channel *c;
419:
420: for (i = 0; i < channels_alloc; i++) {
421: c = channels[i];
422: if (c != NULL) {
423: switch (c->type) {
424: case SSH_CHANNEL_AUTH_SOCKET:
425: case SSH_CHANNEL_PORT_LISTENER:
426: case SSH_CHANNEL_RPORT_LISTENER:
427: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 428: channel_close_fd(&c->sock);
1.131 markus 429: channel_free(c);
430: break;
431: }
432: }
433: }
434: }
435:
436: /*
1.121 markus 437: * Returns true if no channel has too much buffered data, and false if one or
438: * more channel is overfull.
439: */
440: int
1.142 itojun 441: channel_not_very_much_buffered_data(void)
1.121 markus 442: {
443: u_int i;
444: Channel *c;
445:
446: for (i = 0; i < channels_alloc; i++) {
447: c = channels[i];
448: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 449: #if 0
450: if (!compat20 &&
451: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 452: debug2("channel %d: big input buffer %d",
1.121 markus 453: c->self, buffer_len(&c->input));
454: return 0;
455: }
1.136 markus 456: #endif
1.121 markus 457: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 458: debug2("channel %d: big output buffer %u > %u",
1.136 markus 459: c->self, buffer_len(&c->output),
460: packet_get_maxsize());
1.121 markus 461: return 0;
462: }
463: }
464: }
465: return 1;
466: }
467:
468: /* Returns true if any channel is still open. */
469: int
1.142 itojun 470: channel_still_open(void)
1.121 markus 471: {
1.209 avsm 472: u_int i;
1.121 markus 473: Channel *c;
474:
475: for (i = 0; i < channels_alloc; i++) {
476: c = channels[i];
477: if (c == NULL)
478: continue;
479: switch (c->type) {
480: case SSH_CHANNEL_X11_LISTENER:
481: case SSH_CHANNEL_PORT_LISTENER:
482: case SSH_CHANNEL_RPORT_LISTENER:
483: case SSH_CHANNEL_CLOSED:
484: case SSH_CHANNEL_AUTH_SOCKET:
485: case SSH_CHANNEL_DYNAMIC:
486: case SSH_CHANNEL_CONNECTING:
487: case SSH_CHANNEL_ZOMBIE:
488: continue;
489: case SSH_CHANNEL_LARVAL:
490: if (!compat20)
491: fatal("cannot happen: SSH_CHANNEL_LARVAL");
492: continue;
493: case SSH_CHANNEL_OPENING:
494: case SSH_CHANNEL_OPEN:
495: case SSH_CHANNEL_X11_OPEN:
496: return 1;
497: case SSH_CHANNEL_INPUT_DRAINING:
498: case SSH_CHANNEL_OUTPUT_DRAINING:
499: if (!compat13)
500: fatal("cannot happen: OUT_DRAIN");
501: return 1;
502: default:
503: fatal("channel_still_open: bad channel type %d", c->type);
504: /* NOTREACHED */
505: }
506: }
507: return 0;
508: }
509:
510: /* Returns the id of an open channel suitable for keepaliving */
511: int
1.142 itojun 512: channel_find_open(void)
1.121 markus 513: {
1.209 avsm 514: u_int i;
1.121 markus 515: Channel *c;
516:
517: for (i = 0; i < channels_alloc; i++) {
518: c = channels[i];
1.206 djm 519: if (c == NULL || c->remote_id < 0)
1.121 markus 520: continue;
521: switch (c->type) {
522: case SSH_CHANNEL_CLOSED:
523: case SSH_CHANNEL_DYNAMIC:
524: case SSH_CHANNEL_X11_LISTENER:
525: case SSH_CHANNEL_PORT_LISTENER:
526: case SSH_CHANNEL_RPORT_LISTENER:
527: case SSH_CHANNEL_OPENING:
528: case SSH_CHANNEL_CONNECTING:
529: case SSH_CHANNEL_ZOMBIE:
530: continue;
531: case SSH_CHANNEL_LARVAL:
532: case SSH_CHANNEL_AUTH_SOCKET:
533: case SSH_CHANNEL_OPEN:
534: case SSH_CHANNEL_X11_OPEN:
535: return i;
536: case SSH_CHANNEL_INPUT_DRAINING:
537: case SSH_CHANNEL_OUTPUT_DRAINING:
538: if (!compat13)
539: fatal("cannot happen: OUT_DRAIN");
540: return i;
541: default:
542: fatal("channel_find_open: bad channel type %d", c->type);
543: /* NOTREACHED */
544: }
545: }
546: return -1;
547: }
548:
549:
550: /*
551: * Returns a message describing the currently open forwarded connections,
552: * suitable for sending to the client. The message contains crlf pairs for
553: * newlines.
554: */
555: char *
1.142 itojun 556: channel_open_message(void)
1.121 markus 557: {
558: Buffer buffer;
559: Channel *c;
560: char buf[1024], *cp;
1.209 avsm 561: u_int i;
1.121 markus 562:
563: buffer_init(&buffer);
564: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
565: buffer_append(&buffer, buf, strlen(buf));
566: for (i = 0; i < channels_alloc; i++) {
567: c = channels[i];
568: if (c == NULL)
569: continue;
570: switch (c->type) {
571: case SSH_CHANNEL_X11_LISTENER:
572: case SSH_CHANNEL_PORT_LISTENER:
573: case SSH_CHANNEL_RPORT_LISTENER:
574: case SSH_CHANNEL_CLOSED:
575: case SSH_CHANNEL_AUTH_SOCKET:
576: case SSH_CHANNEL_ZOMBIE:
577: continue;
578: case SSH_CHANNEL_LARVAL:
579: case SSH_CHANNEL_OPENING:
580: case SSH_CHANNEL_CONNECTING:
581: case SSH_CHANNEL_DYNAMIC:
582: case SSH_CHANNEL_OPEN:
583: case SSH_CHANNEL_X11_OPEN:
584: case SSH_CHANNEL_INPUT_DRAINING:
585: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 586: snprintf(buf, sizeof buf,
587: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 588: c->self, c->remote_name,
589: c->type, c->remote_id,
590: c->istate, buffer_len(&c->input),
591: c->ostate, buffer_len(&c->output),
1.204 djm 592: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 593: buffer_append(&buffer, buf, strlen(buf));
594: continue;
595: default:
596: fatal("channel_open_message: bad channel type %d", c->type);
597: /* NOTREACHED */
598: }
599: }
600: buffer_append(&buffer, "\0", 1);
601: cp = xstrdup(buffer_ptr(&buffer));
602: buffer_free(&buffer);
603: return cp;
604: }
605:
606: void
607: channel_send_open(int id)
608: {
609: Channel *c = channel_lookup(id);
1.180 deraadt 610:
1.121 markus 611: if (c == NULL) {
1.188 itojun 612: logit("channel_send_open: %d: bad id", id);
1.121 markus 613: return;
614: }
1.184 markus 615: debug2("channel %d: send open", id);
1.121 markus 616: packet_start(SSH2_MSG_CHANNEL_OPEN);
617: packet_put_cstring(c->ctype);
618: packet_put_int(c->self);
619: packet_put_int(c->local_window);
620: packet_put_int(c->local_maxpacket);
621: packet_send();
622: }
623:
624: void
1.184 markus 625: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 626: {
1.184 markus 627: Channel *c = channel_lookup(id);
1.180 deraadt 628:
1.121 markus 629: if (c == NULL) {
1.188 itojun 630: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 631: return;
632: }
1.204 djm 633: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 634: packet_start(SSH2_MSG_CHANNEL_REQUEST);
635: packet_put_int(c->remote_id);
636: packet_put_cstring(service);
637: packet_put_char(wantconfirm);
638: }
1.241 deraadt 639:
1.121 markus 640: void
1.204 djm 641: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 642: {
643: Channel *c = channel_lookup(id);
1.180 deraadt 644:
1.121 markus 645: if (c == NULL) {
1.188 itojun 646: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 647: return;
648: }
1.165 markus 649: c->confirm = fn;
1.204 djm 650: c->confirm_ctx = ctx;
1.121 markus 651: }
1.241 deraadt 652:
1.121 markus 653: void
1.225 djm 654: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 655: {
1.229 markus 656: Channel *c = channel_by_id(id);
1.180 deraadt 657:
1.121 markus 658: if (c == NULL) {
1.188 itojun 659: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 660: return;
661: }
1.131 markus 662: c->detach_user = fn;
1.225 djm 663: c->detach_close = do_close;
1.121 markus 664: }
1.241 deraadt 665:
1.121 markus 666: void
667: channel_cancel_cleanup(int id)
668: {
1.229 markus 669: Channel *c = channel_by_id(id);
1.180 deraadt 670:
1.121 markus 671: if (c == NULL) {
1.188 itojun 672: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 673: return;
1.52 markus 674: }
1.131 markus 675: c->detach_user = NULL;
1.225 djm 676: c->detach_close = 0;
1.121 markus 677: }
1.241 deraadt 678:
1.121 markus 679: void
1.231 reyk 680: channel_register_filter(int id, channel_infilter_fn *ifn,
681: channel_outfilter_fn *ofn)
1.121 markus 682: {
683: Channel *c = channel_lookup(id);
1.180 deraadt 684:
1.121 markus 685: if (c == NULL) {
1.188 itojun 686: logit("channel_register_filter: %d: bad id", id);
1.121 markus 687: return;
1.52 markus 688: }
1.231 reyk 689: c->input_filter = ifn;
690: c->output_filter = ofn;
1.52 markus 691: }
692:
1.49 markus 693: void
1.121 markus 694: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 695: int extusage, int nonblock, u_int window_max)
1.1 deraadt 696: {
1.121 markus 697: Channel *c = channel_lookup(id);
1.180 deraadt 698:
1.121 markus 699: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
700: fatal("channel_activate for non-larval channel %d.", id);
701: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
702: c->type = SSH_CHANNEL_OPEN;
1.168 markus 703: c->local_window = c->local_window_max = window_max;
1.121 markus 704: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
705: packet_put_int(c->remote_id);
706: packet_put_int(c->local_window);
707: packet_send();
1.1 deraadt 708: }
709:
1.27 markus 710: /*
1.41 markus 711: * 'channel_pre*' are called just before select() to add any bits relevant to
712: * channels in the select bitmasks.
713: */
714: /*
715: * 'channel_post*': perform any appropriate operations for channels which
716: * have events pending.
1.27 markus 717: */
1.237 deraadt 718: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 719: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
720: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
721:
1.127 itojun 722: static void
1.237 deraadt 723: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 724: {
725: FD_SET(c->sock, readset);
726: }
727:
1.127 itojun 728: static void
1.237 deraadt 729: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 730: {
731: debug3("channel %d: waiting for connection", c->self);
732: FD_SET(c->sock, writeset);
733: }
734:
1.127 itojun 735: static void
1.237 deraadt 736: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 737: {
738: if (buffer_len(&c->input) < packet_get_maxsize())
739: FD_SET(c->sock, readset);
740: if (buffer_len(&c->output) > 0)
741: FD_SET(c->sock, writeset);
742: }
1.1 deraadt 743:
1.127 itojun 744: static void
1.237 deraadt 745: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 746: {
1.157 markus 747: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 748:
1.214 markus 749: /* check buffer limits */
750: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
751:
1.44 markus 752: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 753: limit > 0 &&
754: buffer_len(&c->input) < limit)
1.44 markus 755: FD_SET(c->rfd, readset);
756: if (c->ostate == CHAN_OUTPUT_OPEN ||
757: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
758: if (buffer_len(&c->output) > 0) {
759: FD_SET(c->wfd, writeset);
760: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 761: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 762: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
763: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 764: else
765: chan_obuf_empty(c);
1.44 markus 766: }
767: }
768: /** XXX check close conditions, too */
1.157 markus 769: if (compat20 && c->efd != -1) {
1.44 markus 770: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
771: buffer_len(&c->extended) > 0)
772: FD_SET(c->efd, writeset);
1.172 markus 773: else if (!(c->flags & CHAN_EOF_SENT) &&
774: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 775: buffer_len(&c->extended) < c->remote_window)
776: FD_SET(c->efd, readset);
777: }
1.204 djm 778: /* XXX: What about efd? races? */
1.208 deraadt 779: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 780: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
781: FD_SET(c->ctl_fd, readset);
1.44 markus 782: }
783:
1.127 itojun 784: static void
1.237 deraadt 785: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 786: {
787: if (buffer_len(&c->input) == 0) {
788: packet_start(SSH_MSG_CHANNEL_CLOSE);
789: packet_put_int(c->remote_id);
790: packet_send();
791: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 792: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 793: }
794: }
795:
1.127 itojun 796: static void
1.237 deraadt 797: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 798: {
799: if (buffer_len(&c->output) == 0)
1.113 markus 800: chan_mark_dead(c);
1.49 markus 801: else
1.41 markus 802: FD_SET(c->sock, writeset);
803: }
804:
805: /*
806: * This is a special state for X11 authentication spoofing. An opened X11
807: * connection (when authentication spoofing is being done) remains in this
808: * state until the first packet has been completely read. The authentication
809: * data in that packet is then substituted by the real data if it matches the
810: * fake data, and the channel is put into normal mode.
1.51 markus 811: * XXX All this happens at the client side.
1.121 markus 812: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 813: */
1.127 itojun 814: static int
1.121 markus 815: x11_open_helper(Buffer *b)
1.1 deraadt 816: {
1.77 markus 817: u_char *ucp;
818: u_int proto_len, data_len;
1.25 markus 819:
1.41 markus 820: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 821: if (buffer_len(b) < 12)
1.41 markus 822: return 0;
823:
824: /* Parse the lengths of variable-length fields. */
1.155 stevesk 825: ucp = buffer_ptr(b);
1.41 markus 826: if (ucp[0] == 0x42) { /* Byte order MSB first. */
827: proto_len = 256 * ucp[6] + ucp[7];
828: data_len = 256 * ucp[8] + ucp[9];
829: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
830: proto_len = ucp[6] + 256 * ucp[7];
831: data_len = ucp[8] + 256 * ucp[9];
832: } else {
1.194 markus 833: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 834: ucp[0]);
1.41 markus 835: return -1;
836: }
837:
838: /* Check if the whole packet is in buffer. */
1.121 markus 839: if (buffer_len(b) <
1.41 markus 840: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
841: return 0;
842:
843: /* Check if authentication protocol matches. */
844: if (proto_len != strlen(x11_saved_proto) ||
845: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 846: debug2("X11 connection uses different authentication protocol.");
1.41 markus 847: return -1;
848: }
849: /* Check if authentication data matches our fake data. */
850: if (data_len != x11_fake_data_len ||
851: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
852: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 853: debug2("X11 auth data does not match fake data.");
1.41 markus 854: return -1;
855: }
856: /* Check fake data length */
857: if (x11_fake_data_len != x11_saved_data_len) {
858: error("X11 fake_data_len %d != saved_data_len %d",
859: x11_fake_data_len, x11_saved_data_len);
860: return -1;
861: }
862: /*
863: * Received authentication protocol and data match
864: * our fake data. Substitute the fake data with real
865: * data.
866: */
867: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
868: x11_saved_data, x11_saved_data_len);
869: return 1;
870: }
871:
1.127 itojun 872: static void
1.237 deraadt 873: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 874: {
1.121 markus 875: int ret = x11_open_helper(&c->output);
1.180 deraadt 876:
1.41 markus 877: if (ret == 1) {
878: /* Start normal processing for the channel. */
879: c->type = SSH_CHANNEL_OPEN;
1.47 markus 880: channel_pre_open_13(c, readset, writeset);
1.41 markus 881: } else if (ret == -1) {
882: /*
883: * We have received an X11 connection that has bad
884: * authentication information.
885: */
1.188 itojun 886: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 887: buffer_clear(&c->input);
888: buffer_clear(&c->output);
1.132 markus 889: channel_close_fd(&c->sock);
1.41 markus 890: c->sock = -1;
891: c->type = SSH_CHANNEL_CLOSED;
892: packet_start(SSH_MSG_CHANNEL_CLOSE);
893: packet_put_int(c->remote_id);
894: packet_send();
895: }
896: }
1.25 markus 897:
1.127 itojun 898: static void
1.237 deraadt 899: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 900: {
1.121 markus 901: int ret = x11_open_helper(&c->output);
1.133 markus 902:
903: /* c->force_drain = 1; */
904:
1.41 markus 905: if (ret == 1) {
906: c->type = SSH_CHANNEL_OPEN;
1.157 markus 907: channel_pre_open(c, readset, writeset);
1.41 markus 908: } else if (ret == -1) {
1.188 itojun 909: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 910: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 911: chan_read_failed(c);
912: buffer_clear(&c->input);
913: chan_ibuf_empty(c);
914: buffer_clear(&c->output);
915: /* for proto v1, the peer will send an IEOF */
916: if (compat20)
917: chan_write_failed(c);
918: else
919: c->type = SSH_CHANNEL_OPEN;
1.194 markus 920: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 921: }
922: }
1.25 markus 923:
1.104 markus 924: /* try to decode a socks4 header */
1.127 itojun 925: static int
1.237 deraadt 926: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 927: {
1.181 markus 928: char *p, *host;
1.217 djm 929: u_int len, have, i, found;
1.148 deraadt 930: char username[256];
1.103 markus 931: struct {
932: u_int8_t version;
933: u_int8_t command;
934: u_int16_t dest_port;
1.104 markus 935: struct in_addr dest_addr;
1.103 markus 936: } s4_req, s4_rsp;
937:
1.104 markus 938: debug2("channel %d: decode socks4", c->self);
1.109 markus 939:
940: have = buffer_len(&c->input);
941: len = sizeof(s4_req);
942: if (have < len)
943: return 0;
944: p = buffer_ptr(&c->input);
945: for (found = 0, i = len; i < have; i++) {
946: if (p[i] == '\0') {
947: found = 1;
948: break;
949: }
950: if (i > 1024) {
951: /* the peer is probably sending garbage */
952: debug("channel %d: decode socks4: too long",
953: c->self);
954: return -1;
955: }
956: }
957: if (!found)
958: return 0;
1.103 markus 959: buffer_get(&c->input, (char *)&s4_req.version, 1);
960: buffer_get(&c->input, (char *)&s4_req.command, 1);
961: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 962: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 963: have = buffer_len(&c->input);
1.103 markus 964: p = buffer_ptr(&c->input);
965: len = strlen(p);
1.106 markus 966: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 967: if (len > have)
1.104 markus 968: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 969: c->self, len, have);
970: strlcpy(username, p, sizeof(username));
971: buffer_consume(&c->input, len);
972: buffer_consume(&c->input, 1); /* trailing '\0' */
973:
1.104 markus 974: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 975: strlcpy(c->path, host, sizeof(c->path));
976: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 977:
1.194 markus 978: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 979: c->self, host, c->host_port, s4_req.command);
1.103 markus 980:
1.104 markus 981: if (s4_req.command != 1) {
982: debug("channel %d: cannot handle: socks4 cn %d",
983: c->self, s4_req.command);
984: return -1;
1.103 markus 985: }
1.104 markus 986: s4_rsp.version = 0; /* vn: 0 for reply */
987: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 988: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 989: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 990: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 991: return 1;
992: }
993:
1.193 markus 994: /* try to decode a socks5 header */
995: #define SSH_SOCKS5_AUTHDONE 0x1000
996: #define SSH_SOCKS5_NOAUTH 0x00
997: #define SSH_SOCKS5_IPV4 0x01
998: #define SSH_SOCKS5_DOMAIN 0x03
999: #define SSH_SOCKS5_IPV6 0x04
1000: #define SSH_SOCKS5_CONNECT 0x01
1001: #define SSH_SOCKS5_SUCCESS 0x00
1002:
1003: static int
1.237 deraadt 1004: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1005: {
1006: struct {
1007: u_int8_t version;
1008: u_int8_t command;
1009: u_int8_t reserved;
1010: u_int8_t atyp;
1011: } s5_req, s5_rsp;
1012: u_int16_t dest_port;
1013: u_char *p, dest_addr[255+1];
1.217 djm 1014: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 1015:
1016: debug2("channel %d: decode socks5", c->self);
1017: p = buffer_ptr(&c->input);
1018: if (p[0] != 0x05)
1019: return -1;
1020: have = buffer_len(&c->input);
1021: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1022: /* format: ver | nmethods | methods */
1.198 djm 1023: if (have < 2)
1.193 markus 1024: return 0;
1025: nmethods = p[1];
1026: if (have < nmethods + 2)
1027: return 0;
1028: /* look for method: "NO AUTHENTICATION REQUIRED" */
1029: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1030: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1031: found = 1;
1032: break;
1033: }
1034: }
1035: if (!found) {
1036: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1037: c->self);
1038: return -1;
1039: }
1040: buffer_consume(&c->input, nmethods + 2);
1041: buffer_put_char(&c->output, 0x05); /* version */
1042: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1043: FD_SET(c->sock, writeset);
1044: c->flags |= SSH_SOCKS5_AUTHDONE;
1045: debug2("channel %d: socks5 auth done", c->self);
1046: return 0; /* need more */
1047: }
1048: debug2("channel %d: socks5 post auth", c->self);
1049: if (have < sizeof(s5_req)+1)
1050: return 0; /* need more */
1.247 deraadt 1051: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1052: if (s5_req.version != 0x05 ||
1053: s5_req.command != SSH_SOCKS5_CONNECT ||
1054: s5_req.reserved != 0x00) {
1.194 markus 1055: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1056: return -1;
1057: }
1.213 deraadt 1058: switch (s5_req.atyp){
1.193 markus 1059: case SSH_SOCKS5_IPV4:
1060: addrlen = 4;
1061: af = AF_INET;
1062: break;
1063: case SSH_SOCKS5_DOMAIN:
1064: addrlen = p[sizeof(s5_req)];
1065: af = -1;
1066: break;
1067: case SSH_SOCKS5_IPV6:
1068: addrlen = 16;
1069: af = AF_INET6;
1070: break;
1071: default:
1.194 markus 1072: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1073: return -1;
1074: }
1075: if (have < 4 + addrlen + 2)
1076: return 0;
1077: buffer_consume(&c->input, sizeof(s5_req));
1078: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1079: buffer_consume(&c->input, 1); /* host string length */
1080: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1081: buffer_get(&c->input, (char *)&dest_port, 2);
1082: dest_addr[addrlen] = '\0';
1083: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1084: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1085: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1086: return -1;
1087: c->host_port = ntohs(dest_port);
1.198 djm 1088:
1.194 markus 1089: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1090: c->self, c->path, c->host_port, s5_req.command);
1091:
1092: s5_rsp.version = 0x05;
1093: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1094: s5_rsp.reserved = 0; /* ignored */
1095: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1096: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1097: dest_port = 0; /* ignored */
1098:
1.246 deraadt 1099: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1100: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1101: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1102: return 1;
1103: }
1104:
1.104 markus 1105: /* dynamic port forwarding */
1.127 itojun 1106: static void
1.237 deraadt 1107: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1108: {
1109: u_char *p;
1.217 djm 1110: u_int have;
1111: int ret;
1.103 markus 1112:
1.104 markus 1113: have = buffer_len(&c->input);
1.137 markus 1114: c->delayed = 0;
1.104 markus 1115: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1116: /* buffer_dump(&c->input); */
1.104 markus 1117: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1118: if (have < 3) {
1.104 markus 1119: /* need more */
1120: FD_SET(c->sock, readset);
1121: return;
1122: }
1123: /* try to guess the protocol */
1124: p = buffer_ptr(&c->input);
1125: switch (p[0]) {
1126: case 0x04:
1127: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1128: break;
1129: case 0x05:
1130: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1131: break;
1132: default:
1133: ret = -1;
1134: break;
1135: }
1136: if (ret < 0) {
1.113 markus 1137: chan_mark_dead(c);
1.104 markus 1138: } else if (ret == 0) {
1139: debug2("channel %d: pre_dynamic: need more", c->self);
1140: /* need more */
1141: FD_SET(c->sock, readset);
1142: } else {
1143: /* switch to the next state */
1144: c->type = SSH_CHANNEL_OPENING;
1145: port_open_helper(c, "direct-tcpip");
1146: }
1.103 markus 1147: }
1148:
1.41 markus 1149: /* This is our fake X11 server socket. */
1.127 itojun 1150: static void
1.237 deraadt 1151: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1152: {
1.113 markus 1153: Channel *nc;
1.41 markus 1154: struct sockaddr addr;
1.162 stevesk 1155: int newsock;
1.41 markus 1156: socklen_t addrlen;
1.85 markus 1157: char buf[16384], *remote_ipaddr;
1.51 markus 1158: int remote_port;
1.25 markus 1159:
1.41 markus 1160: if (FD_ISSET(c->sock, readset)) {
1161: debug("X11 connection requested.");
1162: addrlen = sizeof(addr);
1163: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1164: if (c->single_connection) {
1.194 markus 1165: debug2("single_connection: closing X11 listener.");
1.149 markus 1166: channel_close_fd(&c->sock);
1167: chan_mark_dead(c);
1168: }
1.41 markus 1169: if (newsock < 0) {
1170: error("accept: %.100s", strerror(errno));
1171: return;
1172: }
1.162 stevesk 1173: set_nodelay(newsock);
1.85 markus 1174: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1175: remote_port = get_peer_port(newsock);
1.41 markus 1176: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1177: remote_ipaddr, remote_port);
1.51 markus 1178:
1.113 markus 1179: nc = channel_new("accepted x11 socket",
1.51 markus 1180: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1181: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1182: if (compat20) {
1183: packet_start(SSH2_MSG_CHANNEL_OPEN);
1184: packet_put_cstring("x11");
1.113 markus 1185: packet_put_int(nc->self);
1.149 markus 1186: packet_put_int(nc->local_window_max);
1187: packet_put_int(nc->local_maxpacket);
1.85 markus 1188: /* originator ipaddr and port */
1189: packet_put_cstring(remote_ipaddr);
1.57 markus 1190: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1191: debug2("ssh2 x11 bug compat mode");
1.57 markus 1192: } else {
1193: packet_put_int(remote_port);
1194: }
1.51 markus 1195: packet_send();
1196: } else {
1197: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1198: packet_put_int(nc->self);
1.121 markus 1199: if (packet_get_protocol_flags() &
1200: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1201: packet_put_cstring(buf);
1.51 markus 1202: packet_send();
1203: }
1.85 markus 1204: xfree(remote_ipaddr);
1.41 markus 1205: }
1206: }
1.25 markus 1207:
1.127 itojun 1208: static void
1.103 markus 1209: port_open_helper(Channel *c, char *rtype)
1210: {
1211: int direct;
1212: char buf[1024];
1213: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1214: int remote_port = get_peer_port(c->sock);
1.103 markus 1215:
1216: direct = (strcmp(rtype, "direct-tcpip") == 0);
1217:
1218: snprintf(buf, sizeof buf,
1219: "%s: listening port %d for %.100s port %d, "
1220: "connect from %.200s port %d",
1221: rtype, c->listening_port, c->path, c->host_port,
1222: remote_ipaddr, remote_port);
1223:
1224: xfree(c->remote_name);
1225: c->remote_name = xstrdup(buf);
1226:
1227: if (compat20) {
1228: packet_start(SSH2_MSG_CHANNEL_OPEN);
1229: packet_put_cstring(rtype);
1230: packet_put_int(c->self);
1231: packet_put_int(c->local_window_max);
1232: packet_put_int(c->local_maxpacket);
1233: if (direct) {
1234: /* target host, port */
1235: packet_put_cstring(c->path);
1236: packet_put_int(c->host_port);
1237: } else {
1238: /* listen address, port */
1239: packet_put_cstring(c->path);
1240: packet_put_int(c->listening_port);
1241: }
1242: /* originator host and port */
1243: packet_put_cstring(remote_ipaddr);
1.216 markus 1244: packet_put_int((u_int)remote_port);
1.103 markus 1245: packet_send();
1246: } else {
1247: packet_start(SSH_MSG_PORT_OPEN);
1248: packet_put_int(c->self);
1249: packet_put_cstring(c->path);
1250: packet_put_int(c->host_port);
1.121 markus 1251: if (packet_get_protocol_flags() &
1252: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1253: packet_put_cstring(c->remote_name);
1254: packet_send();
1255: }
1256: xfree(remote_ipaddr);
1257: }
1258:
1.226 djm 1259: static void
1260: channel_set_reuseaddr(int fd)
1261: {
1262: int on = 1;
1263:
1264: /*
1265: * Set socket options.
1266: * Allow local port reuse in TIME_WAIT.
1267: */
1268: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1269: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1270: }
1271:
1.41 markus 1272: /*
1273: * This socket is listening for connections to a forwarded TCP/IP port.
1274: */
1.127 itojun 1275: static void
1.237 deraadt 1276: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1277: {
1.103 markus 1278: Channel *nc;
1.41 markus 1279: struct sockaddr addr;
1.113 markus 1280: int newsock, nextstate;
1.41 markus 1281: socklen_t addrlen;
1.103 markus 1282: char *rtype;
1.73 markus 1283:
1.41 markus 1284: if (FD_ISSET(c->sock, readset)) {
1285: debug("Connection to port %d forwarding "
1286: "to %.100s port %d requested.",
1287: c->listening_port, c->path, c->host_port);
1.103 markus 1288:
1.137 markus 1289: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1290: nextstate = SSH_CHANNEL_OPENING;
1291: rtype = "forwarded-tcpip";
1292: } else {
1293: if (c->host_port == 0) {
1294: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1295: rtype = "dynamic-tcpip";
1.137 markus 1296: } else {
1297: nextstate = SSH_CHANNEL_OPENING;
1298: rtype = "direct-tcpip";
1299: }
1300: }
1.103 markus 1301:
1.41 markus 1302: addrlen = sizeof(addr);
1303: newsock = accept(c->sock, &addr, &addrlen);
1304: if (newsock < 0) {
1305: error("accept: %.100s", strerror(errno));
1306: return;
1307: }
1.169 stevesk 1308: set_nodelay(newsock);
1.190 markus 1309: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1310: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1311: nc->listening_port = c->listening_port;
1312: nc->host_port = c->host_port;
1313: strlcpy(nc->path, c->path, sizeof(nc->path));
1314:
1.137 markus 1315: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1316: /*
1317: * do not call the channel_post handler until
1318: * this flag has been reset by a pre-handler.
1319: * otherwise the FD_ISSET calls might overflow
1320: */
1321: nc->delayed = 1;
1322: } else {
1.103 markus 1323: port_open_helper(nc, rtype);
1.137 markus 1324: }
1.41 markus 1325: }
1326: }
1.25 markus 1327:
1.41 markus 1328: /*
1329: * This is the authentication agent socket listening for connections from
1330: * clients.
1331: */
1.127 itojun 1332: static void
1.237 deraadt 1333: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1334: {
1.113 markus 1335: Channel *nc;
1336: int newsock;
1.41 markus 1337: struct sockaddr addr;
1338: socklen_t addrlen;
1.25 markus 1339:
1.41 markus 1340: if (FD_ISSET(c->sock, readset)) {
1341: addrlen = sizeof(addr);
1342: newsock = accept(c->sock, &addr, &addrlen);
1343: if (newsock < 0) {
1344: error("accept from auth socket: %.100s", strerror(errno));
1345: return;
1346: }
1.113 markus 1347: nc = channel_new("accepted auth socket",
1.73 markus 1348: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1349: c->local_window_max, c->local_maxpacket,
1.190 markus 1350: 0, "accepted auth socket", 1);
1.73 markus 1351: if (compat20) {
1352: packet_start(SSH2_MSG_CHANNEL_OPEN);
1353: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1354: packet_put_int(nc->self);
1.73 markus 1355: packet_put_int(c->local_window_max);
1356: packet_put_int(c->local_maxpacket);
1357: } else {
1358: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1359: packet_put_int(nc->self);
1.73 markus 1360: }
1.41 markus 1361: packet_send();
1362: }
1363: }
1.25 markus 1364:
1.127 itojun 1365: static void
1.237 deraadt 1366: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1367: {
1.114 markus 1368: int err = 0;
1.129 stevesk 1369: socklen_t sz = sizeof(err);
1.114 markus 1370:
1.75 markus 1371: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1372: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1373: err = errno;
1374: error("getsockopt SO_ERROR failed");
1375: }
1376: if (err == 0) {
1377: debug("channel %d: connected", c->self);
1378: c->type = SSH_CHANNEL_OPEN;
1379: if (compat20) {
1380: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1381: packet_put_int(c->remote_id);
1382: packet_put_int(c->self);
1383: packet_put_int(c->local_window);
1384: packet_put_int(c->local_maxpacket);
1385: } else {
1386: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1387: packet_put_int(c->remote_id);
1388: packet_put_int(c->self);
1389: }
1.75 markus 1390: } else {
1.114 markus 1391: debug("channel %d: not connected: %s",
1392: c->self, strerror(err));
1393: if (compat20) {
1394: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1395: packet_put_int(c->remote_id);
1396: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1397: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1398: packet_put_cstring(strerror(err));
1399: packet_put_cstring("");
1400: }
1.75 markus 1401: } else {
1.114 markus 1402: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1403: packet_put_int(c->remote_id);
1.75 markus 1404: }
1.114 markus 1405: chan_mark_dead(c);
1.75 markus 1406: }
1.114 markus 1407: packet_send();
1.75 markus 1408: }
1409: }
1410:
1.127 itojun 1411: static int
1.237 deraadt 1412: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1413: {
1.214 markus 1414: char buf[CHAN_RBUF];
1.41 markus 1415: int len;
1.25 markus 1416:
1.118 markus 1417: if (c->rfd != -1 &&
1.41 markus 1418: FD_ISSET(c->rfd, readset)) {
1419: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1420: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1421: return 1;
1.41 markus 1422: if (len <= 0) {
1.194 markus 1423: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1424: c->self, c->rfd, len);
1.104 markus 1425: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1426: debug2("channel %d: not open", c->self);
1.113 markus 1427: chan_mark_dead(c);
1.103 markus 1428: return -1;
1.104 markus 1429: } else if (compat13) {
1.158 markus 1430: buffer_clear(&c->output);
1.41 markus 1431: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1432: debug2("channel %d: input draining.", c->self);
1.25 markus 1433: } else {
1.41 markus 1434: chan_read_failed(c);
1.25 markus 1435: }
1.41 markus 1436: return -1;
1437: }
1.143 deraadt 1438: if (c->input_filter != NULL) {
1.66 markus 1439: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1440: debug2("channel %d: filter stops", c->self);
1.65 markus 1441: chan_read_failed(c);
1442: }
1.228 reyk 1443: } else if (c->datagram) {
1444: buffer_put_string(&c->input, buf, len);
1.65 markus 1445: } else {
1446: buffer_append(&c->input, buf, len);
1447: }
1.41 markus 1448: }
1449: return 1;
1450: }
1.241 deraadt 1451:
1.127 itojun 1452: static int
1.237 deraadt 1453: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1454: {
1.95 markus 1455: struct termios tio;
1.231 reyk 1456: u_char *data = NULL, *buf;
1.134 markus 1457: u_int dlen;
1.41 markus 1458: int len;
1.25 markus 1459:
1.41 markus 1460: /* Send buffered output data to the socket. */
1.118 markus 1461: if (c->wfd != -1 &&
1.41 markus 1462: FD_ISSET(c->wfd, writeset) &&
1463: buffer_len(&c->output) > 0) {
1.231 reyk 1464: if (c->output_filter != NULL) {
1465: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1466: debug2("channel %d: filter stops", c->self);
1.232 reyk 1467: if (c->type != SSH_CHANNEL_OPEN)
1468: chan_mark_dead(c);
1469: else
1470: chan_write_failed(c);
1471: return -1;
1.231 reyk 1472: }
1473: } else if (c->datagram) {
1474: buf = data = buffer_get_string(&c->output, &dlen);
1475: } else {
1476: buf = data = buffer_ptr(&c->output);
1477: dlen = buffer_len(&c->output);
1478: }
1479:
1.228 reyk 1480: if (c->datagram) {
1481: /* ignore truncated writes, datagrams might get lost */
1482: c->local_consumed += dlen + 4;
1.231 reyk 1483: len = write(c->wfd, buf, dlen);
1.228 reyk 1484: xfree(data);
1485: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1486: return 1;
1487: if (len <= 0) {
1488: if (c->type != SSH_CHANNEL_OPEN)
1489: chan_mark_dead(c);
1490: else
1491: chan_write_failed(c);
1492: return -1;
1493: }
1494: return 1;
1495: }
1.231 reyk 1496:
1497: len = write(c->wfd, buf, dlen);
1.53 markus 1498: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1499: return 1;
1.41 markus 1500: if (len <= 0) {
1.104 markus 1501: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1502: debug2("channel %d: not open", c->self);
1.113 markus 1503: chan_mark_dead(c);
1.104 markus 1504: return -1;
1505: } else if (compat13) {
1.158 markus 1506: buffer_clear(&c->output);
1.194 markus 1507: debug2("channel %d: input draining.", c->self);
1.41 markus 1508: c->type = SSH_CHANNEL_INPUT_DRAINING;
1509: } else {
1510: chan_write_failed(c);
1511: }
1512: return -1;
1.91 markus 1513: }
1.231 reyk 1514: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1515: if (tcgetattr(c->wfd, &tio) == 0 &&
1516: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1517: /*
1518: * Simulate echo to reduce the impact of
1.96 markus 1519: * traffic analysis. We need to match the
1.95 markus 1520: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1521: * (4 byte channel id + buf)
1.91 markus 1522: */
1.95 markus 1523: packet_send_ignore(4 + len);
1.91 markus 1524: packet_send();
1525: }
1.25 markus 1526: }
1.41 markus 1527: buffer_consume(&c->output, len);
1.44 markus 1528: if (compat20 && len > 0) {
1529: c->local_consumed += len;
1530: }
1531: }
1532: return 1;
1533: }
1.241 deraadt 1534:
1.127 itojun 1535: static int
1.237 deraadt 1536: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1537: {
1.214 markus 1538: char buf[CHAN_RBUF];
1.44 markus 1539: int len;
1540:
1.45 markus 1541: /** XXX handle drain efd, too */
1.44 markus 1542: if (c->efd != -1) {
1543: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1544: FD_ISSET(c->efd, writeset) &&
1545: buffer_len(&c->extended) > 0) {
1546: len = write(c->efd, buffer_ptr(&c->extended),
1547: buffer_len(&c->extended));
1.70 markus 1548: debug2("channel %d: written %d to efd %d",
1.44 markus 1549: c->self, len, c->efd);
1.93 markus 1550: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1551: return 1;
1552: if (len <= 0) {
1553: debug2("channel %d: closing write-efd %d",
1554: c->self, c->efd);
1.132 markus 1555: channel_close_fd(&c->efd);
1.93 markus 1556: } else {
1.44 markus 1557: buffer_consume(&c->extended, len);
1558: c->local_consumed += len;
1559: }
1560: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1561: FD_ISSET(c->efd, readset)) {
1562: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1563: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1564: c->self, len, c->efd);
1.93 markus 1565: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1566: return 1;
1567: if (len <= 0) {
1568: debug2("channel %d: closing read-efd %d",
1.45 markus 1569: c->self, c->efd);
1.132 markus 1570: channel_close_fd(&c->efd);
1.93 markus 1571: } else {
1.44 markus 1572: buffer_append(&c->extended, buf, len);
1.93 markus 1573: }
1.44 markus 1574: }
1575: }
1576: return 1;
1577: }
1.241 deraadt 1578:
1.127 itojun 1579: static int
1.237 deraadt 1580: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1581: {
1582: char buf[16];
1583: int len;
1584:
1585: /* Monitor control fd to detect if the slave client exits */
1586: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1587: len = read(c->ctl_fd, buf, sizeof(buf));
1588: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1589: return 1;
1590: if (len <= 0) {
1591: debug2("channel %d: ctl read<=0", c->self);
1592: if (c->type != SSH_CHANNEL_OPEN) {
1593: debug2("channel %d: not open", c->self);
1594: chan_mark_dead(c);
1595: return -1;
1596: } else {
1597: chan_read_failed(c);
1598: chan_write_failed(c);
1599: }
1600: return -1;
1601: } else
1602: fatal("%s: unexpected data on ctl fd", __func__);
1603: }
1604: return 1;
1605: }
1.241 deraadt 1606:
1.204 djm 1607: static int
1.93 markus 1608: channel_check_window(Channel *c)
1.44 markus 1609: {
1.104 markus 1610: if (c->type == SSH_CHANNEL_OPEN &&
1611: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1612: c->local_window < c->local_window_max/2 &&
1613: c->local_consumed > 0) {
1614: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1615: packet_put_int(c->remote_id);
1616: packet_put_int(c->local_consumed);
1617: packet_send();
1.70 markus 1618: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1619: c->self, c->local_window,
1620: c->local_consumed);
1621: c->local_window += c->local_consumed;
1622: c->local_consumed = 0;
1.1 deraadt 1623: }
1.41 markus 1624: return 1;
1.1 deraadt 1625: }
1626:
1.127 itojun 1627: static void
1.237 deraadt 1628: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1629: {
1.137 markus 1630: if (c->delayed)
1631: return;
1.41 markus 1632: channel_handle_rfd(c, readset, writeset);
1633: channel_handle_wfd(c, readset, writeset);
1.157 markus 1634: if (!compat20)
1.137 markus 1635: return;
1.44 markus 1636: channel_handle_efd(c, readset, writeset);
1.204 djm 1637: channel_handle_ctl(c, readset, writeset);
1.93 markus 1638: channel_check_window(c);
1.44 markus 1639: }
1640:
1.127 itojun 1641: static void
1.237 deraadt 1642: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1643: {
1.41 markus 1644: int len;
1.180 deraadt 1645:
1.41 markus 1646: /* Send buffered output data to the socket. */
1647: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1648: len = write(c->sock, buffer_ptr(&c->output),
1649: buffer_len(&c->output));
1650: if (len <= 0)
1.158 markus 1651: buffer_clear(&c->output);
1.41 markus 1652: else
1653: buffer_consume(&c->output, len);
1654: }
1655: }
1.25 markus 1656:
1.127 itojun 1657: static void
1.44 markus 1658: channel_handler_init_20(void)
1659: {
1.157 markus 1660: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1661: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1662: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1663: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1664: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1665: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1666: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1667: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1668:
1.157 markus 1669: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1670: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1671: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1672: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1673: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1674: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1675: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1676: }
1677:
1.127 itojun 1678: static void
1.41 markus 1679: channel_handler_init_13(void)
1680: {
1681: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1682: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1683: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1684: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1685: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1686: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1687: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1688: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1689: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1690:
1.157 markus 1691: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1692: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1693: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1694: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1695: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1696: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1697: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1698: }
1.25 markus 1699:
1.127 itojun 1700: static void
1.41 markus 1701: channel_handler_init_15(void)
1702: {
1.157 markus 1703: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1704: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1705: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1706: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1707: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1708: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1709: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1710:
1.41 markus 1711: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1712: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1713: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1714: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1715: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1716: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1717: }
1.27 markus 1718:
1.127 itojun 1719: static void
1.41 markus 1720: channel_handler_init(void)
1721: {
1722: int i;
1.180 deraadt 1723:
1.148 deraadt 1724: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1725: channel_pre[i] = NULL;
1726: channel_post[i] = NULL;
1727: }
1.44 markus 1728: if (compat20)
1729: channel_handler_init_20();
1730: else if (compat13)
1.41 markus 1731: channel_handler_init_13();
1732: else
1733: channel_handler_init_15();
1734: }
1.25 markus 1735:
1.140 markus 1736: /* gc dead channels */
1737: static void
1738: channel_garbage_collect(Channel *c)
1739: {
1740: if (c == NULL)
1741: return;
1742: if (c->detach_user != NULL) {
1.225 djm 1743: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1744: return;
1.194 markus 1745: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1746: c->detach_user(c->self, NULL);
1747: /* if we still have a callback */
1748: if (c->detach_user != NULL)
1749: return;
1.194 markus 1750: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1751: }
1752: if (!chan_is_dead(c, 1))
1753: return;
1.194 markus 1754: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1755: channel_free(c);
1756: }
1757:
1.127 itojun 1758: static void
1.237 deraadt 1759: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1760: {
1761: static int did_init = 0;
1.209 avsm 1762: u_int i;
1.41 markus 1763: Channel *c;
1.25 markus 1764:
1.41 markus 1765: if (!did_init) {
1766: channel_handler_init();
1767: did_init = 1;
1768: }
1769: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1770: c = channels[i];
1771: if (c == NULL)
1.41 markus 1772: continue;
1.118 markus 1773: if (ftab[c->type] != NULL)
1774: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1775: channel_garbage_collect(c);
1.1 deraadt 1776: }
1777: }
1778:
1.121 markus 1779: /*
1780: * Allocate/update select bitmasks and add any bits relevant to channels in
1781: * select bitmasks.
1782: */
1.49 markus 1783: void
1.100 markus 1784: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1785: u_int *nallocp, int rekeying)
1.41 markus 1786: {
1.243 djm 1787: u_int n, sz, nfdset;
1.84 markus 1788:
1789: n = MAX(*maxfdp, channel_max_fd);
1790:
1.243 djm 1791: nfdset = howmany(n+1, NFDBITS);
1792: /* Explicitly test here, because xrealloc isn't always called */
1793: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1794: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1795: sz = nfdset * sizeof(fd_mask);
1796:
1.132 markus 1797: /* perhaps check sz < nalloc/2 and shrink? */
1798: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1799: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1800: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1801: *nallocp = sz;
1.84 markus 1802: }
1.132 markus 1803: *maxfdp = n;
1.84 markus 1804: memset(*readsetp, 0, sz);
1805: memset(*writesetp, 0, sz);
1806:
1.100 markus 1807: if (!rekeying)
1808: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1809: }
1810:
1.121 markus 1811: /*
1812: * After select, perform any appropriate operations for channels which have
1813: * events pending.
1814: */
1.49 markus 1815: void
1.237 deraadt 1816: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1817: {
1818: channel_handler(channel_post, readset, writeset);
1819: }
1820:
1.121 markus 1821:
1.84 markus 1822: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1823: void
1.142 itojun 1824: channel_output_poll(void)
1.1 deraadt 1825: {
1.41 markus 1826: Channel *c;
1.209 avsm 1827: u_int i, len;
1.1 deraadt 1828:
1.25 markus 1829: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1830: c = channels[i];
1831: if (c == NULL)
1832: continue;
1.37 markus 1833:
1.121 markus 1834: /*
1835: * We are only interested in channels that can have buffered
1836: * incoming data.
1837: */
1.37 markus 1838: if (compat13) {
1.41 markus 1839: if (c->type != SSH_CHANNEL_OPEN &&
1840: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1841: continue;
1842: } else {
1.41 markus 1843: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1844: continue;
1845: }
1.46 markus 1846: if (compat20 &&
1847: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1848: /* XXX is this true? */
1.140 markus 1849: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1850: continue;
1851: }
1.25 markus 1852:
1853: /* Get the amount of buffered data for this channel. */
1.93 markus 1854: if ((c->istate == CHAN_INPUT_OPEN ||
1855: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1856: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1857: if (c->datagram) {
1858: if (len > 0) {
1859: u_char *data;
1860: u_int dlen;
1861:
1862: data = buffer_get_string(&c->input,
1863: &dlen);
1864: packet_start(SSH2_MSG_CHANNEL_DATA);
1865: packet_put_int(c->remote_id);
1866: packet_put_string(data, dlen);
1867: packet_send();
1868: c->remote_window -= dlen + 4;
1869: xfree(data);
1870: }
1871: continue;
1872: }
1.121 markus 1873: /*
1874: * Send some data for the other side over the secure
1875: * connection.
1876: */
1.44 markus 1877: if (compat20) {
1878: if (len > c->remote_window)
1879: len = c->remote_window;
1880: if (len > c->remote_maxpacket)
1881: len = c->remote_maxpacket;
1.25 markus 1882: } else {
1.44 markus 1883: if (packet_is_interactive()) {
1884: if (len > 1024)
1885: len = 512;
1886: } else {
1887: /* Keep the packets at reasonable size. */
1888: if (len > packet_get_maxsize()/2)
1889: len = packet_get_maxsize()/2;
1890: }
1.25 markus 1891: }
1.41 markus 1892: if (len > 0) {
1.44 markus 1893: packet_start(compat20 ?
1894: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1895: packet_put_int(c->remote_id);
1896: packet_put_string(buffer_ptr(&c->input), len);
1897: packet_send();
1898: buffer_consume(&c->input, len);
1899: c->remote_window -= len;
1900: }
1901: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1902: if (compat13)
1903: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1904: /*
1905: * input-buffer is empty and read-socket shutdown:
1.172 markus 1906: * tell peer, that we will not send more data: send IEOF.
1907: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1908: */
1.172 markus 1909: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1910: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1911: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1912: else
1913: chan_ibuf_empty(c);
1.25 markus 1914: }
1.44 markus 1915: /* Send extended data, i.e. stderr */
1916: if (compat20 &&
1.172 markus 1917: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1918: c->remote_window > 0 &&
1919: (len = buffer_len(&c->extended)) > 0 &&
1920: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1921: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1922: c->self, c->remote_window, buffer_len(&c->extended),
1923: c->extended_usage);
1.44 markus 1924: if (len > c->remote_window)
1925: len = c->remote_window;
1926: if (len > c->remote_maxpacket)
1927: len = c->remote_maxpacket;
1928: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1929: packet_put_int(c->remote_id);
1930: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1931: packet_put_string(buffer_ptr(&c->extended), len);
1932: packet_send();
1933: buffer_consume(&c->extended, len);
1934: c->remote_window -= len;
1.93 markus 1935: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1936: }
1.25 markus 1937: }
1.1 deraadt 1938: }
1939:
1.121 markus 1940:
1941: /* -- protocol input */
1.249 ! djm 1942:
! 1943: /* ARGSUSED */
1.49 markus 1944: void
1.154 markus 1945: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1946: {
1.37 markus 1947: int id;
1.25 markus 1948: char *data;
1.77 markus 1949: u_int data_len;
1.41 markus 1950: Channel *c;
1.25 markus 1951:
1952: /* Get the channel number and verify it. */
1.37 markus 1953: id = packet_get_int();
1.41 markus 1954: c = channel_lookup(id);
1955: if (c == NULL)
1.37 markus 1956: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1957:
1958: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1959: if (c->type != SSH_CHANNEL_OPEN &&
1960: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1961: return;
1962:
1.25 markus 1963: /* Get the data. */
1964: data = packet_get_string(&data_len);
1.200 markus 1965:
1966: /*
1967: * Ignore data for protocol > 1.3 if output end is no longer open.
1968: * For protocol 2 the sending side is reducing its window as it sends
1969: * data, so we must 'fake' consumption of the data in order to ensure
1970: * that window updates are sent back. Otherwise the connection might
1971: * deadlock.
1972: */
1973: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1974: if (compat20) {
1975: c->local_window -= data_len;
1976: c->local_consumed += data_len;
1977: }
1978: xfree(data);
1979: return;
1980: }
1.41 markus 1981:
1.143 deraadt 1982: if (compat20) {
1.44 markus 1983: if (data_len > c->local_maxpacket) {
1.188 itojun 1984: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1985: c->self, data_len, c->local_maxpacket);
1986: }
1987: if (data_len > c->local_window) {
1.188 itojun 1988: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1989: c->self, data_len, c->local_window);
1990: xfree(data);
1991: return;
1992: }
1993: c->local_window -= data_len;
1994: }
1.152 markus 1995: packet_check_eom();
1.228 reyk 1996: if (c->datagram)
1997: buffer_put_string(&c->output, data, data_len);
1998: else
1999: buffer_append(&c->output, data, data_len);
1.25 markus 2000: xfree(data);
1.1 deraadt 2001: }
1.121 markus 2002:
1.249 ! djm 2003: /* ARGSUSED */
1.49 markus 2004: void
1.154 markus 2005: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2006: {
2007: int id;
2008: char *data;
1.177 markus 2009: u_int data_len, tcode;
1.44 markus 2010: Channel *c;
2011:
2012: /* Get the channel number and verify it. */
2013: id = packet_get_int();
2014: c = channel_lookup(id);
2015:
2016: if (c == NULL)
2017: packet_disconnect("Received extended_data for bad channel %d.", id);
2018: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2019: logit("channel %d: ext data for non open", id);
1.44 markus 2020: return;
1.172 markus 2021: }
2022: if (c->flags & CHAN_EOF_RCVD) {
2023: if (datafellows & SSH_BUG_EXTEOF)
2024: debug("channel %d: accepting ext data after eof", id);
2025: else
2026: packet_disconnect("Received extended_data after EOF "
2027: "on channel %d.", id);
1.44 markus 2028: }
2029: tcode = packet_get_int();
2030: if (c->efd == -1 ||
2031: c->extended_usage != CHAN_EXTENDED_WRITE ||
2032: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2033: logit("channel %d: bad ext data", c->self);
1.44 markus 2034: return;
2035: }
2036: data = packet_get_string(&data_len);
1.152 markus 2037: packet_check_eom();
1.44 markus 2038: if (data_len > c->local_window) {
1.188 itojun 2039: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2040: c->self, data_len, c->local_window);
2041: xfree(data);
2042: return;
2043: }
1.70 markus 2044: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2045: c->local_window -= data_len;
2046: buffer_append(&c->extended, data, data_len);
2047: xfree(data);
2048: }
2049:
1.249 ! djm 2050: /* ARGSUSED */
1.49 markus 2051: void
1.154 markus 2052: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2053: {
2054: int id;
2055: Channel *c;
2056:
2057: id = packet_get_int();
1.152 markus 2058: packet_check_eom();
1.41 markus 2059: c = channel_lookup(id);
2060: if (c == NULL)
2061: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2062: chan_rcvd_ieof(c);
1.133 markus 2063:
2064: /* XXX force input close */
1.156 markus 2065: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2066: debug("channel %d: FORCE input drain", c->self);
2067: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2068: if (buffer_len(&c->input) == 0)
2069: chan_ibuf_empty(c);
1.133 markus 2070: }
2071:
1.41 markus 2072: }
1.1 deraadt 2073:
1.249 ! djm 2074: /* ARGSUSED */
1.49 markus 2075: void
1.154 markus 2076: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2077: {
1.41 markus 2078: int id;
2079: Channel *c;
1.1 deraadt 2080:
1.41 markus 2081: id = packet_get_int();
1.152 markus 2082: packet_check_eom();
1.41 markus 2083: c = channel_lookup(id);
2084: if (c == NULL)
2085: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2086:
2087: /*
2088: * Send a confirmation that we have closed the channel and no more
2089: * data is coming for it.
2090: */
1.25 markus 2091: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2092: packet_put_int(c->remote_id);
1.25 markus 2093: packet_send();
2094:
1.27 markus 2095: /*
2096: * If the channel is in closed state, we have sent a close request,
2097: * and the other side will eventually respond with a confirmation.
2098: * Thus, we cannot free the channel here, because then there would be
2099: * no-one to receive the confirmation. The channel gets freed when
2100: * the confirmation arrives.
2101: */
1.41 markus 2102: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2103: /*
2104: * Not a closed channel - mark it as draining, which will
2105: * cause it to be freed later.
2106: */
1.158 markus 2107: buffer_clear(&c->input);
1.41 markus 2108: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2109: }
1.1 deraadt 2110: }
2111:
1.41 markus 2112: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 ! djm 2113: /* ARGSUSED */
1.49 markus 2114: void
1.154 markus 2115: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2116: {
2117: int id = packet_get_int();
2118: Channel *c = channel_lookup(id);
1.151 markus 2119:
1.152 markus 2120: packet_check_eom();
1.41 markus 2121: if (c == NULL)
2122: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2123: chan_rcvd_oclose(c);
2124: }
1.1 deraadt 2125:
1.249 ! djm 2126: /* ARGSUSED */
1.49 markus 2127: void
1.154 markus 2128: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2129: {
1.41 markus 2130: int id = packet_get_int();
2131: Channel *c = channel_lookup(id);
1.1 deraadt 2132:
1.152 markus 2133: packet_check_eom();
1.41 markus 2134: if (c == NULL)
2135: packet_disconnect("Received close confirmation for "
2136: "out-of-range channel %d.", id);
2137: if (c->type != SSH_CHANNEL_CLOSED)
2138: packet_disconnect("Received close confirmation for "
2139: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2140: channel_free(c);
1.1 deraadt 2141: }
2142:
1.249 ! djm 2143: /* ARGSUSED */
1.49 markus 2144: void
1.154 markus 2145: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2146: {
1.41 markus 2147: int id, remote_id;
2148: Channel *c;
1.1 deraadt 2149:
1.41 markus 2150: id = packet_get_int();
2151: c = channel_lookup(id);
1.25 markus 2152:
1.41 markus 2153: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2154: packet_disconnect("Received open confirmation for "
2155: "non-opening channel %d.", id);
2156: remote_id = packet_get_int();
1.27 markus 2157: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2158: c->remote_id = remote_id;
2159: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2160:
2161: if (compat20) {
2162: c->remote_window = packet_get_int();
2163: c->remote_maxpacket = packet_get_int();
1.165 markus 2164: if (c->confirm) {
1.70 markus 2165: debug2("callback start");
1.204 djm 2166: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2167: debug2("callback done");
1.44 markus 2168: }
1.194 markus 2169: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2170: c->remote_window, c->remote_maxpacket);
2171: }
1.152 markus 2172: packet_check_eom();
1.1 deraadt 2173: }
2174:
1.127 itojun 2175: static char *
1.114 markus 2176: reason2txt(int reason)
2177: {
1.143 deraadt 2178: switch (reason) {
1.114 markus 2179: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2180: return "administratively prohibited";
2181: case SSH2_OPEN_CONNECT_FAILED:
2182: return "connect failed";
2183: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2184: return "unknown channel type";
2185: case SSH2_OPEN_RESOURCE_SHORTAGE:
2186: return "resource shortage";
2187: }
1.117 stevesk 2188: return "unknown reason";
1.114 markus 2189: }
2190:
1.249 ! djm 2191: /* ARGSUSED */
1.49 markus 2192: void
1.154 markus 2193: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2194: {
1.86 markus 2195: int id, reason;
2196: char *msg = NULL, *lang = NULL;
1.41 markus 2197: Channel *c;
2198:
2199: id = packet_get_int();
2200: c = channel_lookup(id);
1.25 markus 2201:
1.41 markus 2202: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2203: packet_disconnect("Received open failure for "
2204: "non-opening channel %d.", id);
1.44 markus 2205: if (compat20) {
1.86 markus 2206: reason = packet_get_int();
1.110 markus 2207: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2208: msg = packet_get_string(NULL);
2209: lang = packet_get_string(NULL);
2210: }
1.188 itojun 2211: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2212: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2213: if (msg != NULL)
2214: xfree(msg);
2215: if (lang != NULL)
2216: xfree(lang);
1.44 markus 2217: }
1.152 markus 2218: packet_check_eom();
1.25 markus 2219: /* Free the channel. This will also close the socket. */
1.113 markus 2220: channel_free(c);
1.44 markus 2221: }
2222:
1.249 ! djm 2223: /* ARGSUSED */
1.121 markus 2224: void
1.154 markus 2225: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2226: {
2227: Channel *c;
1.178 markus 2228: int id;
2229: u_int adjust;
1.121 markus 2230:
2231: if (!compat20)
2232: return;
2233:
2234: /* Get the channel number and verify it. */
2235: id = packet_get_int();
2236: c = channel_lookup(id);
1.1 deraadt 2237:
1.229 markus 2238: if (c == NULL) {
2239: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2240: return;
2241: }
2242: adjust = packet_get_int();
1.152 markus 2243: packet_check_eom();
1.178 markus 2244: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2245: c->remote_window += adjust;
2246: }
1.1 deraadt 2247:
1.249 ! djm 2248: /* ARGSUSED */
1.121 markus 2249: void
1.154 markus 2250: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2251: {
1.121 markus 2252: Channel *c = NULL;
2253: u_short host_port;
2254: char *host, *originator_string;
2255: int remote_id, sock = -1;
2256:
2257: remote_id = packet_get_int();
2258: host = packet_get_string(NULL);
2259: host_port = packet_get_int();
1.25 markus 2260:
1.121 markus 2261: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2262: originator_string = packet_get_string(NULL);
2263: } else {
2264: originator_string = xstrdup("unknown (remote did not supply name)");
2265: }
1.152 markus 2266: packet_check_eom();
1.121 markus 2267: sock = channel_connect_to(host, host_port);
2268: if (sock != -1) {
2269: c = channel_new("connected socket",
2270: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2271: originator_string, 1);
1.167 markus 2272: c->remote_id = remote_id;
1.25 markus 2273: }
1.190 markus 2274: xfree(originator_string);
1.121 markus 2275: if (c == NULL) {
2276: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2277: packet_put_int(remote_id);
2278: packet_send();
2279: }
2280: xfree(host);
1.1 deraadt 2281: }
2282:
1.121 markus 2283:
2284: /* -- tcp forwarding */
1.135 markus 2285:
2286: void
2287: channel_set_af(int af)
2288: {
2289: IPv4or6 = af;
2290: }
1.121 markus 2291:
1.160 markus 2292: static int
2293: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2294: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2295: {
1.113 markus 2296: Channel *c;
1.226 djm 2297: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2298: struct addrinfo hints, *ai, *aitop;
1.212 djm 2299: const char *host, *addr;
1.35 markus 2300: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2301:
1.160 markus 2302: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2303: listen_addr : host_to_connect;
1.212 djm 2304: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2305:
1.160 markus 2306: if (host == NULL) {
2307: error("No forward host name.");
1.218 markus 2308: return 0;
1.73 markus 2309: }
1.113 markus 2310: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2311: error("Forward host name too long.");
1.218 markus 2312: return 0;
1.87 markus 2313: }
1.25 markus 2314:
1.28 markus 2315: /*
1.212 djm 2316: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2317: * specified address or wildcard. On the client, a specified bind
2318: * address will always override gateway_ports. On the server, a
2319: * gateway_ports of 1 (``yes'') will override the client's
2320: * specification and force a wildcard bind, whereas a value of 2
2321: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2322: * asked for.
2323: *
2324: * Special-case listen_addrs are:
2325: *
2326: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2327: * "" (empty string), "*" -> wildcard v4/v6
2328: * "localhost" -> loopback v4/v6
2329: */
2330: addr = NULL;
2331: if (listen_addr == NULL) {
2332: /* No address specified: default to gateway_ports setting */
2333: if (gateway_ports)
2334: wildcard = 1;
2335: } else if (gateway_ports || is_client) {
2336: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2337: strcmp(listen_addr, "0.0.0.0") == 0) ||
2338: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2339: (!is_client && gateway_ports == 1))
2340: wildcard = 1;
2341: else if (strcmp(listen_addr, "localhost") != 0)
2342: addr = listen_addr;
2343: }
2344:
2345: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2346: type, wildcard, (addr == NULL) ? "NULL" : addr);
2347:
2348: /*
1.35 markus 2349: * getaddrinfo returns a loopback address if the hostname is
2350: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2351: */
1.35 markus 2352: memset(&hints, 0, sizeof(hints));
2353: hints.ai_family = IPv4or6;
1.212 djm 2354: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2355: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2356: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2357: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2358: if (addr == NULL) {
2359: /* This really shouldn't happen */
2360: packet_disconnect("getaddrinfo: fatal error: %s",
2361: gai_strerror(r));
2362: } else {
1.218 markus 2363: error("channel_setup_fwd_listener: "
1.212 djm 2364: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2365: }
1.218 markus 2366: return 0;
1.212 djm 2367: }
1.35 markus 2368:
2369: for (ai = aitop; ai; ai = ai->ai_next) {
2370: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2371: continue;
2372: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2373: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2374: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2375: continue;
2376: }
2377: /* Create a port to listen for the host. */
1.189 markus 2378: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2379: if (sock < 0) {
2380: /* this is no error since kernel may not support ipv6 */
2381: verbose("socket: %.100s", strerror(errno));
2382: continue;
2383: }
1.226 djm 2384:
2385: channel_set_reuseaddr(sock);
1.182 stevesk 2386:
1.35 markus 2387: debug("Local forwarding listening on %s port %s.", ntop, strport);
2388:
2389: /* Bind the socket to the address. */
2390: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2391: /* address can be in use ipv6 address is already bound */
2392: verbose("bind: %.100s", strerror(errno));
2393: close(sock);
2394: continue;
2395: }
2396: /* Start listening for connections on the socket. */
1.199 markus 2397: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2398: error("listen: %.100s", strerror(errno));
2399: close(sock);
2400: continue;
2401: }
2402: /* Allocate a channel number for the socket. */
1.121 markus 2403: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2404: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2405: 0, "port listener", 1);
1.113 markus 2406: strlcpy(c->path, host, sizeof(c->path));
2407: c->host_port = port_to_connect;
2408: c->listening_port = listen_port;
1.35 markus 2409: success = 1;
2410: }
2411: if (success == 0)
1.160 markus 2412: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2413: listen_port);
1.35 markus 2414: freeaddrinfo(aitop);
1.87 markus 2415: return success;
1.25 markus 2416: }
1.1 deraadt 2417:
1.202 djm 2418: int
2419: channel_cancel_rport_listener(const char *host, u_short port)
2420: {
1.209 avsm 2421: u_int i;
2422: int found = 0;
1.202 djm 2423:
1.213 deraadt 2424: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2425: Channel *c = channels[i];
2426:
2427: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2428: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2429: c->listening_port == port) {
1.210 djm 2430: debug2("%s: close channel %d", __func__, i);
1.202 djm 2431: channel_free(c);
2432: found = 1;
2433: }
2434: }
2435:
2436: return (found);
2437: }
2438:
1.160 markus 2439: /* protocol local port fwd, used by ssh (and sshd in v1) */
2440: int
1.212 djm 2441: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2442: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2443: {
2444: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2445: listen_host, listen_port, host_to_connect, port_to_connect,
2446: gateway_ports);
1.160 markus 2447: }
2448:
2449: /* protocol v2 remote port fwd, used by sshd */
2450: int
2451: channel_setup_remote_fwd_listener(const char *listen_address,
2452: u_short listen_port, int gateway_ports)
2453: {
2454: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2455: listen_address, listen_port, NULL, 0, gateway_ports);
2456: }
2457:
1.27 markus 2458: /*
2459: * Initiate forwarding of connections to port "port" on remote host through
2460: * the secure channel to host:port from local side.
2461: */
1.1 deraadt 2462:
1.49 markus 2463: void
1.212 djm 2464: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2465: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2466: {
1.153 markus 2467: int type, success = 0;
1.73 markus 2468:
1.25 markus 2469: /* Record locally that connection to this host/port is permitted. */
2470: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2471: fatal("channel_request_remote_forwarding: too many forwards");
2472:
2473: /* Send the forward request to the remote side. */
1.44 markus 2474: if (compat20) {
1.212 djm 2475: const char *address_to_bind;
2476: if (listen_host == NULL)
2477: address_to_bind = "localhost";
2478: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2479: address_to_bind = "";
2480: else
2481: address_to_bind = listen_host;
2482:
1.44 markus 2483: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2484: packet_put_cstring("tcpip-forward");
1.173 markus 2485: packet_put_char(1); /* boolean: want reply */
1.44 markus 2486: packet_put_cstring(address_to_bind);
2487: packet_put_int(listen_port);
1.73 markus 2488: packet_send();
2489: packet_write_wait();
2490: /* Assume that server accepts the request */
2491: success = 1;
1.44 markus 2492: } else {
2493: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2494: packet_put_int(listen_port);
2495: packet_put_cstring(host_to_connect);
1.44 markus 2496: packet_put_int(port_to_connect);
2497: packet_send();
2498: packet_write_wait();
1.73 markus 2499:
2500: /* Wait for response from the remote side. */
1.153 markus 2501: type = packet_read();
1.73 markus 2502: switch (type) {
2503: case SSH_SMSG_SUCCESS:
2504: success = 1;
2505: break;
2506: case SSH_SMSG_FAILURE:
1.188 itojun 2507: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2508: break;
2509: default:
2510: /* Unknown packet */
2511: packet_disconnect("Protocol error for port forward request:"
2512: "received packet type %d.", type);
2513: }
2514: }
2515: if (success) {
2516: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2517: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2518: permitted_opens[num_permitted_opens].listen_port = listen_port;
2519: num_permitted_opens++;
1.44 markus 2520: }
1.1 deraadt 2521: }
2522:
1.27 markus 2523: /*
1.208 deraadt 2524: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2525: * local side.
2526: */
2527: void
1.212 djm 2528: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2529: {
2530: int i;
2531:
2532: if (!compat20)
2533: return;
2534:
2535: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2536: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2537: permitted_opens[i].listen_port == port)
2538: break;
2539: }
2540: if (i >= num_permitted_opens) {
2541: debug("%s: requested forward not found", __func__);
2542: return;
2543: }
2544: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2545: packet_put_cstring("cancel-tcpip-forward");
2546: packet_put_char(0);
1.212 djm 2547: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2548: packet_put_int(port);
2549: packet_send();
2550:
2551: permitted_opens[i].listen_port = 0;
2552: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2553: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2554: permitted_opens[i].host_to_connect = NULL;
2555: }
2556:
2557: /*
1.27 markus 2558: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2559: * listening for the port, and sends back a success reply (or disconnect
2560: * message if there was an error). This never returns if there was an error.
2561: */
1.49 markus 2562: void
1.56 markus 2563: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2564: {
1.31 markus 2565: u_short port, host_port;
1.25 markus 2566: char *hostname;
1.1 deraadt 2567:
1.25 markus 2568: /* Get arguments from the packet. */
2569: port = packet_get_int();
2570: hostname = packet_get_string(NULL);
2571: host_port = packet_get_int();
2572:
1.27 markus 2573: /*
2574: * Check that an unprivileged user is not trying to forward a
2575: * privileged port.
2576: */
1.25 markus 2577: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2578: packet_disconnect(
2579: "Requested forwarding of port %d but user is not root.",
2580: port);
2581: if (host_port == 0)
2582: packet_disconnect("Dynamic forwarding denied.");
2583:
1.73 markus 2584: /* Initiate forwarding */
1.212 djm 2585: channel_setup_local_fwd_listener(NULL, port, hostname,
2586: host_port, gateway_ports);
1.25 markus 2587:
2588: /* Free the argument string. */
2589: xfree(hostname);
1.1 deraadt 2590: }
2591:
1.99 markus 2592: /*
2593: * Permits opening to any host/port if permitted_opens[] is empty. This is
2594: * usually called by the server, because the user could connect to any port
2595: * anyway, and the server has no way to know but to trust the client anyway.
2596: */
2597: void
1.142 itojun 2598: channel_permit_all_opens(void)
1.99 markus 2599: {
2600: if (num_permitted_opens == 0)
2601: all_opens_permitted = 1;
2602: }
2603:
1.101 markus 2604: void
1.99 markus 2605: channel_add_permitted_opens(char *host, int port)
2606: {
2607: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2608: fatal("channel_request_remote_forwarding: too many forwards");
2609: debug("allow port forwarding to host %s port %d", host, port);
2610:
2611: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2612: permitted_opens[num_permitted_opens].port_to_connect = port;
2613: num_permitted_opens++;
2614:
2615: all_opens_permitted = 0;
2616: }
2617:
1.101 markus 2618: void
1.99 markus 2619: channel_clear_permitted_opens(void)
2620: {
2621: int i;
2622:
2623: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2624: if (permitted_opens[i].host_to_connect != NULL)
2625: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2626: num_permitted_opens = 0;
2627:
2628: }
2629:
2630: /* return socket to remote host, port */
1.127 itojun 2631: static int
1.99 markus 2632: connect_to(const char *host, u_short port)
1.41 markus 2633: {
2634: struct addrinfo hints, *ai, *aitop;
2635: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2636: int gaierr;
2637: int sock = -1;
2638:
2639: memset(&hints, 0, sizeof(hints));
2640: hints.ai_family = IPv4or6;
2641: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2642: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2643: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2644: error("connect_to %.100s: unknown host (%s)", host,
2645: gai_strerror(gaierr));
1.41 markus 2646: return -1;
2647: }
2648: for (ai = aitop; ai; ai = ai->ai_next) {
2649: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2650: continue;
2651: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2652: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2653: error("connect_to: getnameinfo failed");
1.41 markus 2654: continue;
2655: }
1.189 markus 2656: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2657: if (sock < 0) {
1.186 djm 2658: if (ai->ai_next == NULL)
2659: error("socket: %.100s", strerror(errno));
2660: else
2661: verbose("socket: %.100s", strerror(errno));
1.41 markus 2662: continue;
2663: }
1.205 djm 2664: if (set_nonblock(sock) == -1)
2665: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2666: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2667: errno != EINPROGRESS) {
1.99 markus 2668: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2669: strerror(errno));
2670: close(sock);
1.89 stevesk 2671: continue; /* fail -- try next */
1.41 markus 2672: }
2673: break; /* success */
2674:
2675: }
2676: freeaddrinfo(aitop);
2677: if (!ai) {
1.99 markus 2678: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2679: return -1;
2680: }
2681: /* success */
1.169 stevesk 2682: set_nodelay(sock);
1.41 markus 2683: return sock;
2684: }
1.99 markus 2685:
1.73 markus 2686: int
1.130 stevesk 2687: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2688: {
2689: int i;
1.99 markus 2690:
1.73 markus 2691: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2692: if (permitted_opens[i].host_to_connect != NULL &&
2693: permitted_opens[i].listen_port == listen_port)
1.99 markus 2694: return connect_to(
1.73 markus 2695: permitted_opens[i].host_to_connect,
2696: permitted_opens[i].port_to_connect);
1.74 markus 2697: error("WARNING: Server requests forwarding for unknown listen_port %d",
2698: listen_port);
1.73 markus 2699: return -1;
2700: }
2701:
1.99 markus 2702: /* Check if connecting to that port is permitted and connect. */
2703: int
2704: channel_connect_to(const char *host, u_short port)
2705: {
2706: int i, permit;
2707:
2708: permit = all_opens_permitted;
2709: if (!permit) {
2710: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2711: if (permitted_opens[i].host_to_connect != NULL &&
2712: permitted_opens[i].port_to_connect == port &&
1.99 markus 2713: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2714: permit = 1;
2715:
2716: }
2717: if (!permit) {
1.188 itojun 2718: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2719: "but the request was denied.", host, port);
2720: return -1;
2721: }
2722: return connect_to(host, port);
1.204 djm 2723: }
2724:
2725: void
2726: channel_send_window_changes(void)
2727: {
1.209 avsm 2728: u_int i;
1.204 djm 2729: struct winsize ws;
2730:
2731: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2732: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2733: channels[i]->type != SSH_CHANNEL_OPEN)
2734: continue;
2735: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2736: continue;
2737: channel_request_start(i, "window-change", 0);
1.238 deraadt 2738: packet_put_int((u_int)ws.ws_col);
2739: packet_put_int((u_int)ws.ws_row);
2740: packet_put_int((u_int)ws.ws_xpixel);
2741: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2742: packet_send();
2743: }
1.99 markus 2744: }
2745:
1.121 markus 2746: /* -- X11 forwarding */
1.1 deraadt 2747:
1.27 markus 2748: /*
2749: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2750: * Returns 0 and a suitable display number for the DISPLAY variable
2751: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2752: */
1.141 stevesk 2753: int
1.163 stevesk 2754: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2755: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2756: {
1.149 markus 2757: Channel *nc = NULL;
1.31 markus 2758: int display_number, sock;
2759: u_short port;
1.35 markus 2760: struct addrinfo hints, *ai, *aitop;
2761: char strport[NI_MAXSERV];
2762: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2763:
1.224 markus 2764: if (chanids == NULL)
2765: return -1;
2766:
1.33 markus 2767: for (display_number = x11_display_offset;
1.148 deraadt 2768: display_number < MAX_DISPLAYS;
2769: display_number++) {
1.25 markus 2770: port = 6000 + display_number;
1.35 markus 2771: memset(&hints, 0, sizeof(hints));
2772: hints.ai_family = IPv4or6;
1.163 stevesk 2773: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2774: hints.ai_socktype = SOCK_STREAM;
2775: snprintf(strport, sizeof strport, "%d", port);
2776: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2777: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2778: return -1;
1.25 markus 2779: }
1.35 markus 2780: for (ai = aitop; ai; ai = ai->ai_next) {
2781: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2782: continue;
1.189 markus 2783: sock = socket(ai->ai_family, ai->ai_socktype,
2784: ai->ai_protocol);
1.35 markus 2785: if (sock < 0) {
2786: error("socket: %.100s", strerror(errno));
1.203 markus 2787: freeaddrinfo(aitop);
1.141 stevesk 2788: return -1;
1.35 markus 2789: }
1.226 djm 2790: channel_set_reuseaddr(sock);
1.35 markus 2791: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2792: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2793: close(sock);
1.183 itojun 2794:
2795: if (ai->ai_next)
2796: continue;
2797:
1.35 markus 2798: for (n = 0; n < num_socks; n++) {
2799: close(socks[n]);
2800: }
2801: num_socks = 0;
2802: break;
2803: }
2804: socks[num_socks++] = sock;
2805: if (num_socks == NUM_SOCKS)
2806: break;
1.25 markus 2807: }
1.83 stevesk 2808: freeaddrinfo(aitop);
1.35 markus 2809: if (num_socks > 0)
2810: break;
1.25 markus 2811: }
2812: if (display_number >= MAX_DISPLAYS) {
2813: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2814: return -1;
1.25 markus 2815: }
2816: /* Start listening for connections on the socket. */
1.35 markus 2817: for (n = 0; n < num_socks; n++) {
2818: sock = socks[n];
1.199 markus 2819: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2820: error("listen: %.100s", strerror(errno));
2821: close(sock);
1.141 stevesk 2822: return -1;
1.35 markus 2823: }
1.25 markus 2824: }
1.35 markus 2825:
2826: /* Allocate a channel for each socket. */
1.242 djm 2827: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2828: for (n = 0; n < num_socks; n++) {
2829: sock = socks[n];
1.149 markus 2830: nc = channel_new("x11 listener",
1.51 markus 2831: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2832: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2833: 0, "X11 inet listener", 1);
1.167 markus 2834: nc->single_connection = single_connection;
1.224 markus 2835: (*chanids)[n] = nc->self;
1.35 markus 2836: }
1.224 markus 2837: (*chanids)[n] = -1;
1.1 deraadt 2838:
1.141 stevesk 2839: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2840: *display_numberp = display_number;
2841: return (0);
1.1 deraadt 2842: }
2843:
1.127 itojun 2844: static int
1.77 markus 2845: connect_local_xsocket(u_int dnr)
1.1 deraadt 2846: {
1.25 markus 2847: int sock;
2848: struct sockaddr_un addr;
2849:
1.147 stevesk 2850: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2851: if (sock < 0)
2852: error("socket: %.100s", strerror(errno));
2853: memset(&addr, 0, sizeof(addr));
2854: addr.sun_family = AF_UNIX;
2855: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2856: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2857: return sock;
2858: close(sock);
1.25 markus 2859: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2860: return -1;
1.1 deraadt 2861: }
2862:
1.51 markus 2863: int
2864: x11_connect_display(void)
1.1 deraadt 2865: {
1.248 deraadt 2866: u_int display_number;
1.25 markus 2867: const char *display;
1.51 markus 2868: char buf[1024], *cp;
1.35 markus 2869: struct addrinfo hints, *ai, *aitop;
2870: char strport[NI_MAXSERV];
1.248 deraadt 2871: int gaierr, sock = 0;
1.25 markus 2872:
2873: /* Try to open a socket for the local X server. */
2874: display = getenv("DISPLAY");
2875: if (!display) {
2876: error("DISPLAY not set.");
1.51 markus 2877: return -1;
1.25 markus 2878: }
1.27 markus 2879: /*
2880: * Now we decode the value of the DISPLAY variable and make a
2881: * connection to the real X server.
2882: */
2883:
2884: /*
2885: * Check if it is a unix domain socket. Unix domain displays are in
2886: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2887: */
1.25 markus 2888: if (strncmp(display, "unix:", 5) == 0 ||
2889: display[0] == ':') {
2890: /* Connect to the unix domain socket. */
1.248 deraadt 2891: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 2892: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2893: display);
1.51 markus 2894: return -1;
1.25 markus 2895: }
2896: /* Create a socket. */
2897: sock = connect_local_xsocket(display_number);
2898: if (sock < 0)
1.51 markus 2899: return -1;
1.25 markus 2900:
2901: /* OK, we now have a connection to the display. */
1.51 markus 2902: return sock;
1.25 markus 2903: }
1.27 markus 2904: /*
2905: * Connect to an inet socket. The DISPLAY value is supposedly
2906: * hostname:d[.s], where hostname may also be numeric IP address.
2907: */
1.145 stevesk 2908: strlcpy(buf, display, sizeof(buf));
1.25 markus 2909: cp = strchr(buf, ':');
2910: if (!cp) {
2911: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2912: return -1;
1.25 markus 2913: }
2914: *cp = 0;
1.27 markus 2915: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 2916: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 2917: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2918: display);
1.51 markus 2919: return -1;
1.25 markus 2920: }
1.35 markus 2921:
2922: /* Look up the host address */
2923: memset(&hints, 0, sizeof(hints));
2924: hints.ai_family = IPv4or6;
2925: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 2926: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 2927: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2928: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2929: return -1;
1.25 markus 2930: }
1.35 markus 2931: for (ai = aitop; ai; ai = ai->ai_next) {
2932: /* Create a socket. */
1.189 markus 2933: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2934: if (sock < 0) {
1.194 markus 2935: debug2("socket: %.100s", strerror(errno));
1.41 markus 2936: continue;
2937: }
2938: /* Connect it to the display. */
2939: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 2940: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 2941: 6000 + display_number, strerror(errno));
2942: close(sock);
2943: continue;
2944: }
2945: /* Success */
2946: break;
1.35 markus 2947: }
2948: freeaddrinfo(aitop);
2949: if (!ai) {
1.248 deraadt 2950: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 2951: strerror(errno));
1.51 markus 2952: return -1;
1.25 markus 2953: }
1.162 stevesk 2954: set_nodelay(sock);
1.51 markus 2955: return sock;
2956: }
2957:
2958: /*
2959: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2960: * the remote channel number. We should do whatever we want, and respond
2961: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2962: */
2963:
2964: void
1.154 markus 2965: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2966: {
1.113 markus 2967: Channel *c = NULL;
2968: int remote_id, sock = 0;
1.51 markus 2969: char *remote_host;
1.25 markus 2970:
1.113 markus 2971: debug("Received X11 open request.");
1.51 markus 2972:
1.113 markus 2973: remote_id = packet_get_int();
1.121 markus 2974:
2975: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2976: remote_host = packet_get_string(NULL);
1.51 markus 2977: } else {
2978: remote_host = xstrdup("unknown (remote did not supply name)");
2979: }
1.152 markus 2980: packet_check_eom();
1.25 markus 2981:
1.51 markus 2982: /* Obtain a connection to the real X display. */
2983: sock = x11_connect_display();
1.113 markus 2984: if (sock != -1) {
2985: /* Allocate a channel for this connection. */
2986: c = channel_new("connected x11 socket",
2987: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2988: remote_host, 1);
1.167 markus 2989: c->remote_id = remote_id;
2990: c->force_drain = 1;
1.113 markus 2991: }
1.190 markus 2992: xfree(remote_host);
1.113 markus 2993: if (c == NULL) {
1.51 markus 2994: /* Send refusal to the remote host. */
2995: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2996: packet_put_int(remote_id);
1.51 markus 2997: } else {
2998: /* Send a confirmation to the remote host. */
2999: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3000: packet_put_int(remote_id);
3001: packet_put_int(c->self);
1.51 markus 3002: }
1.113 markus 3003: packet_send();
1.72 markus 3004: }
3005:
3006: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3007: void
1.154 markus 3008: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3009: {
3010: int rchan = packet_get_int();
1.180 deraadt 3011:
1.143 deraadt 3012: switch (type) {
1.72 markus 3013: case SSH_SMSG_AGENT_OPEN:
3014: error("Warning: ssh server tried agent forwarding.");
3015: break;
3016: case SSH_SMSG_X11_OPEN:
3017: error("Warning: ssh server tried X11 forwarding.");
3018: break;
3019: default:
1.154 markus 3020: error("deny_input_open: type %d", type);
1.72 markus 3021: break;
3022: }
1.230 stevesk 3023: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3024: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3025: packet_put_int(rchan);
3026: packet_send();
1.1 deraadt 3027: }
3028:
1.27 markus 3029: /*
3030: * Requests forwarding of X11 connections, generates fake authentication
3031: * data, and enables authentication spoofing.
1.121 markus 3032: * This should be called in the client only.
1.27 markus 3033: */
1.49 markus 3034: void
1.215 djm 3035: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3036: const char *proto, const char *data)
1.1 deraadt 3037: {
1.77 markus 3038: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3039: u_int i, value;
1.25 markus 3040: char *new_data;
3041: int screen_number;
3042: const char *cp;
1.207 avsm 3043: u_int32_t rnd = 0;
1.25 markus 3044:
1.220 markus 3045: if (x11_saved_display == NULL)
3046: x11_saved_display = xstrdup(disp);
3047: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3048: error("x11_request_forwarding_with_spoofing: different "
3049: "$DISPLAY already forwarded");
3050: return;
3051: }
3052:
1.215 djm 3053: cp = disp;
3054: if (disp)
3055: cp = strchr(disp, ':');
1.25 markus 3056: if (cp)
3057: cp = strchr(cp, '.');
3058: if (cp)
1.245 deraadt 3059: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3060: else
3061: screen_number = 0;
3062:
1.219 djm 3063: if (x11_saved_proto == NULL) {
3064: /* Save protocol name. */
3065: x11_saved_proto = xstrdup(proto);
3066: /*
1.221 djm 3067: * Extract real authentication data and generate fake data
1.219 djm 3068: * of the same length.
3069: */
3070: x11_saved_data = xmalloc(data_len);
3071: x11_fake_data = xmalloc(data_len);
3072: for (i = 0; i < data_len; i++) {
3073: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3074: fatal("x11_request_forwarding: bad "
3075: "authentication data: %.100s", data);
3076: if (i % 4 == 0)
3077: rnd = arc4random();
3078: x11_saved_data[i] = value;
3079: x11_fake_data[i] = rnd & 0xff;
3080: rnd >>= 8;
3081: }
3082: x11_saved_data_len = data_len;
3083: x11_fake_data_len = data_len;
1.25 markus 3084: }
3085:
3086: /* Convert the fake data into hex. */
1.219 djm 3087: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3088:
3089: /* Send the request packet. */
1.51 markus 3090: if (compat20) {
3091: channel_request_start(client_session_id, "x11-req", 0);
3092: packet_put_char(0); /* XXX bool single connection */
3093: } else {
3094: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3095: }
3096: packet_put_cstring(proto);
3097: packet_put_cstring(new_data);
1.25 markus 3098: packet_put_int(screen_number);
3099: packet_send();
3100: packet_write_wait();
3101: xfree(new_data);
1.1 deraadt 3102: }
3103:
1.121 markus 3104:
3105: /* -- agent forwarding */
3106:
1.1 deraadt 3107: /* Sends a message to the server to request authentication fd forwarding. */
3108:
1.49 markus 3109: void
1.142 itojun 3110: auth_request_forwarding(void)
1.1 deraadt 3111: {
1.25 markus 3112: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3113: packet_send();
3114: packet_write_wait();
1.1 deraadt 3115: }