Annotation of src/usr.bin/ssh/channels.c, Revision 1.250
1.250 ! djm 1: /* $OpenBSD: channels.c,v 1.249 2006/03/30 09:41:25 djm Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
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:
1.44 markus 749: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 750: limit > 0 &&
1.250 ! djm 751: buffer_len(&c->input) < limit &&
! 752: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 753: FD_SET(c->rfd, readset);
754: if (c->ostate == CHAN_OUTPUT_OPEN ||
755: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
756: if (buffer_len(&c->output) > 0) {
757: FD_SET(c->wfd, writeset);
758: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 759: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 760: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
761: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 762: else
763: chan_obuf_empty(c);
1.44 markus 764: }
765: }
766: /** XXX check close conditions, too */
1.157 markus 767: if (compat20 && c->efd != -1) {
1.44 markus 768: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
769: buffer_len(&c->extended) > 0)
770: FD_SET(c->efd, writeset);
1.172 markus 771: else if (!(c->flags & CHAN_EOF_SENT) &&
772: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 773: buffer_len(&c->extended) < c->remote_window)
774: FD_SET(c->efd, readset);
775: }
1.204 djm 776: /* XXX: What about efd? races? */
1.208 deraadt 777: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 778: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
779: FD_SET(c->ctl_fd, readset);
1.44 markus 780: }
781:
1.127 itojun 782: static void
1.237 deraadt 783: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 784: {
785: if (buffer_len(&c->input) == 0) {
786: packet_start(SSH_MSG_CHANNEL_CLOSE);
787: packet_put_int(c->remote_id);
788: packet_send();
789: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 790: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 791: }
792: }
793:
1.127 itojun 794: static void
1.237 deraadt 795: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 796: {
797: if (buffer_len(&c->output) == 0)
1.113 markus 798: chan_mark_dead(c);
1.49 markus 799: else
1.41 markus 800: FD_SET(c->sock, writeset);
801: }
802:
803: /*
804: * This is a special state for X11 authentication spoofing. An opened X11
805: * connection (when authentication spoofing is being done) remains in this
806: * state until the first packet has been completely read. The authentication
807: * data in that packet is then substituted by the real data if it matches the
808: * fake data, and the channel is put into normal mode.
1.51 markus 809: * XXX All this happens at the client side.
1.121 markus 810: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 811: */
1.127 itojun 812: static int
1.121 markus 813: x11_open_helper(Buffer *b)
1.1 deraadt 814: {
1.77 markus 815: u_char *ucp;
816: u_int proto_len, data_len;
1.25 markus 817:
1.41 markus 818: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 819: if (buffer_len(b) < 12)
1.41 markus 820: return 0;
821:
822: /* Parse the lengths of variable-length fields. */
1.155 stevesk 823: ucp = buffer_ptr(b);
1.41 markus 824: if (ucp[0] == 0x42) { /* Byte order MSB first. */
825: proto_len = 256 * ucp[6] + ucp[7];
826: data_len = 256 * ucp[8] + ucp[9];
827: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
828: proto_len = ucp[6] + 256 * ucp[7];
829: data_len = ucp[8] + 256 * ucp[9];
830: } else {
1.194 markus 831: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 832: ucp[0]);
1.41 markus 833: return -1;
834: }
835:
836: /* Check if the whole packet is in buffer. */
1.121 markus 837: if (buffer_len(b) <
1.41 markus 838: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
839: return 0;
840:
841: /* Check if authentication protocol matches. */
842: if (proto_len != strlen(x11_saved_proto) ||
843: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 844: debug2("X11 connection uses different authentication protocol.");
1.41 markus 845: return -1;
846: }
847: /* Check if authentication data matches our fake data. */
848: if (data_len != x11_fake_data_len ||
849: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
850: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 851: debug2("X11 auth data does not match fake data.");
1.41 markus 852: return -1;
853: }
854: /* Check fake data length */
855: if (x11_fake_data_len != x11_saved_data_len) {
856: error("X11 fake_data_len %d != saved_data_len %d",
857: x11_fake_data_len, x11_saved_data_len);
858: return -1;
859: }
860: /*
861: * Received authentication protocol and data match
862: * our fake data. Substitute the fake data with real
863: * data.
864: */
865: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
866: x11_saved_data, x11_saved_data_len);
867: return 1;
868: }
869:
1.127 itojun 870: static void
1.237 deraadt 871: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 872: {
1.121 markus 873: int ret = x11_open_helper(&c->output);
1.180 deraadt 874:
1.41 markus 875: if (ret == 1) {
876: /* Start normal processing for the channel. */
877: c->type = SSH_CHANNEL_OPEN;
1.47 markus 878: channel_pre_open_13(c, readset, writeset);
1.41 markus 879: } else if (ret == -1) {
880: /*
881: * We have received an X11 connection that has bad
882: * authentication information.
883: */
1.188 itojun 884: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 885: buffer_clear(&c->input);
886: buffer_clear(&c->output);
1.132 markus 887: channel_close_fd(&c->sock);
1.41 markus 888: c->sock = -1;
889: c->type = SSH_CHANNEL_CLOSED;
890: packet_start(SSH_MSG_CHANNEL_CLOSE);
891: packet_put_int(c->remote_id);
892: packet_send();
893: }
894: }
1.25 markus 895:
1.127 itojun 896: static void
1.237 deraadt 897: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 898: {
1.121 markus 899: int ret = x11_open_helper(&c->output);
1.133 markus 900:
901: /* c->force_drain = 1; */
902:
1.41 markus 903: if (ret == 1) {
904: c->type = SSH_CHANNEL_OPEN;
1.157 markus 905: channel_pre_open(c, readset, writeset);
1.41 markus 906: } else if (ret == -1) {
1.188 itojun 907: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 908: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 909: chan_read_failed(c);
910: buffer_clear(&c->input);
911: chan_ibuf_empty(c);
912: buffer_clear(&c->output);
913: /* for proto v1, the peer will send an IEOF */
914: if (compat20)
915: chan_write_failed(c);
916: else
917: c->type = SSH_CHANNEL_OPEN;
1.194 markus 918: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 919: }
920: }
1.25 markus 921:
1.104 markus 922: /* try to decode a socks4 header */
1.127 itojun 923: static int
1.237 deraadt 924: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 925: {
1.181 markus 926: char *p, *host;
1.217 djm 927: u_int len, have, i, found;
1.148 deraadt 928: char username[256];
1.103 markus 929: struct {
930: u_int8_t version;
931: u_int8_t command;
932: u_int16_t dest_port;
1.104 markus 933: struct in_addr dest_addr;
1.103 markus 934: } s4_req, s4_rsp;
935:
1.104 markus 936: debug2("channel %d: decode socks4", c->self);
1.109 markus 937:
938: have = buffer_len(&c->input);
939: len = sizeof(s4_req);
940: if (have < len)
941: return 0;
942: p = buffer_ptr(&c->input);
943: for (found = 0, i = len; i < have; i++) {
944: if (p[i] == '\0') {
945: found = 1;
946: break;
947: }
948: if (i > 1024) {
949: /* the peer is probably sending garbage */
950: debug("channel %d: decode socks4: too long",
951: c->self);
952: return -1;
953: }
954: }
955: if (!found)
956: return 0;
1.103 markus 957: buffer_get(&c->input, (char *)&s4_req.version, 1);
958: buffer_get(&c->input, (char *)&s4_req.command, 1);
959: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 960: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 961: have = buffer_len(&c->input);
1.103 markus 962: p = buffer_ptr(&c->input);
963: len = strlen(p);
1.106 markus 964: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 965: if (len > have)
1.104 markus 966: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 967: c->self, len, have);
968: strlcpy(username, p, sizeof(username));
969: buffer_consume(&c->input, len);
970: buffer_consume(&c->input, 1); /* trailing '\0' */
971:
1.104 markus 972: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 973: strlcpy(c->path, host, sizeof(c->path));
974: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 975:
1.194 markus 976: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 977: c->self, host, c->host_port, s4_req.command);
1.103 markus 978:
1.104 markus 979: if (s4_req.command != 1) {
980: debug("channel %d: cannot handle: socks4 cn %d",
981: c->self, s4_req.command);
982: return -1;
1.103 markus 983: }
1.104 markus 984: s4_rsp.version = 0; /* vn: 0 for reply */
985: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 986: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 987: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 988: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 989: return 1;
990: }
991:
1.193 markus 992: /* try to decode a socks5 header */
993: #define SSH_SOCKS5_AUTHDONE 0x1000
994: #define SSH_SOCKS5_NOAUTH 0x00
995: #define SSH_SOCKS5_IPV4 0x01
996: #define SSH_SOCKS5_DOMAIN 0x03
997: #define SSH_SOCKS5_IPV6 0x04
998: #define SSH_SOCKS5_CONNECT 0x01
999: #define SSH_SOCKS5_SUCCESS 0x00
1000:
1001: static int
1.237 deraadt 1002: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1003: {
1004: struct {
1005: u_int8_t version;
1006: u_int8_t command;
1007: u_int8_t reserved;
1008: u_int8_t atyp;
1009: } s5_req, s5_rsp;
1010: u_int16_t dest_port;
1011: u_char *p, dest_addr[255+1];
1.217 djm 1012: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 1013:
1014: debug2("channel %d: decode socks5", c->self);
1015: p = buffer_ptr(&c->input);
1016: if (p[0] != 0x05)
1017: return -1;
1018: have = buffer_len(&c->input);
1019: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1020: /* format: ver | nmethods | methods */
1.198 djm 1021: if (have < 2)
1.193 markus 1022: return 0;
1023: nmethods = p[1];
1024: if (have < nmethods + 2)
1025: return 0;
1026: /* look for method: "NO AUTHENTICATION REQUIRED" */
1027: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1028: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1029: found = 1;
1030: break;
1031: }
1032: }
1033: if (!found) {
1034: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1035: c->self);
1036: return -1;
1037: }
1038: buffer_consume(&c->input, nmethods + 2);
1039: buffer_put_char(&c->output, 0x05); /* version */
1040: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1041: FD_SET(c->sock, writeset);
1042: c->flags |= SSH_SOCKS5_AUTHDONE;
1043: debug2("channel %d: socks5 auth done", c->self);
1044: return 0; /* need more */
1045: }
1046: debug2("channel %d: socks5 post auth", c->self);
1047: if (have < sizeof(s5_req)+1)
1048: return 0; /* need more */
1.247 deraadt 1049: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1050: if (s5_req.version != 0x05 ||
1051: s5_req.command != SSH_SOCKS5_CONNECT ||
1052: s5_req.reserved != 0x00) {
1.194 markus 1053: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1054: return -1;
1055: }
1.213 deraadt 1056: switch (s5_req.atyp){
1.193 markus 1057: case SSH_SOCKS5_IPV4:
1058: addrlen = 4;
1059: af = AF_INET;
1060: break;
1061: case SSH_SOCKS5_DOMAIN:
1062: addrlen = p[sizeof(s5_req)];
1063: af = -1;
1064: break;
1065: case SSH_SOCKS5_IPV6:
1066: addrlen = 16;
1067: af = AF_INET6;
1068: break;
1069: default:
1.194 markus 1070: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1071: return -1;
1072: }
1073: if (have < 4 + addrlen + 2)
1074: return 0;
1075: buffer_consume(&c->input, sizeof(s5_req));
1076: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1077: buffer_consume(&c->input, 1); /* host string length */
1078: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1079: buffer_get(&c->input, (char *)&dest_port, 2);
1080: dest_addr[addrlen] = '\0';
1081: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1082: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1083: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1084: return -1;
1085: c->host_port = ntohs(dest_port);
1.198 djm 1086:
1.194 markus 1087: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1088: c->self, c->path, c->host_port, s5_req.command);
1089:
1090: s5_rsp.version = 0x05;
1091: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1092: s5_rsp.reserved = 0; /* ignored */
1093: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1094: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1095: dest_port = 0; /* ignored */
1096:
1.246 deraadt 1097: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1098: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1099: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1100: return 1;
1101: }
1102:
1.104 markus 1103: /* dynamic port forwarding */
1.127 itojun 1104: static void
1.237 deraadt 1105: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1106: {
1107: u_char *p;
1.217 djm 1108: u_int have;
1109: int ret;
1.103 markus 1110:
1.104 markus 1111: have = buffer_len(&c->input);
1.137 markus 1112: c->delayed = 0;
1.104 markus 1113: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1114: /* buffer_dump(&c->input); */
1.104 markus 1115: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1116: if (have < 3) {
1.104 markus 1117: /* need more */
1118: FD_SET(c->sock, readset);
1119: return;
1120: }
1121: /* try to guess the protocol */
1122: p = buffer_ptr(&c->input);
1123: switch (p[0]) {
1124: case 0x04:
1125: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1126: break;
1127: case 0x05:
1128: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1129: break;
1130: default:
1131: ret = -1;
1132: break;
1133: }
1134: if (ret < 0) {
1.113 markus 1135: chan_mark_dead(c);
1.104 markus 1136: } else if (ret == 0) {
1137: debug2("channel %d: pre_dynamic: need more", c->self);
1138: /* need more */
1139: FD_SET(c->sock, readset);
1140: } else {
1141: /* switch to the next state */
1142: c->type = SSH_CHANNEL_OPENING;
1143: port_open_helper(c, "direct-tcpip");
1144: }
1.103 markus 1145: }
1146:
1.41 markus 1147: /* This is our fake X11 server socket. */
1.127 itojun 1148: static void
1.237 deraadt 1149: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1150: {
1.113 markus 1151: Channel *nc;
1.41 markus 1152: struct sockaddr addr;
1.162 stevesk 1153: int newsock;
1.41 markus 1154: socklen_t addrlen;
1.85 markus 1155: char buf[16384], *remote_ipaddr;
1.51 markus 1156: int remote_port;
1.25 markus 1157:
1.41 markus 1158: if (FD_ISSET(c->sock, readset)) {
1159: debug("X11 connection requested.");
1160: addrlen = sizeof(addr);
1161: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1162: if (c->single_connection) {
1.194 markus 1163: debug2("single_connection: closing X11 listener.");
1.149 markus 1164: channel_close_fd(&c->sock);
1165: chan_mark_dead(c);
1166: }
1.41 markus 1167: if (newsock < 0) {
1168: error("accept: %.100s", strerror(errno));
1169: return;
1170: }
1.162 stevesk 1171: set_nodelay(newsock);
1.85 markus 1172: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1173: remote_port = get_peer_port(newsock);
1.41 markus 1174: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1175: remote_ipaddr, remote_port);
1.51 markus 1176:
1.113 markus 1177: nc = channel_new("accepted x11 socket",
1.51 markus 1178: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1179: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1180: if (compat20) {
1181: packet_start(SSH2_MSG_CHANNEL_OPEN);
1182: packet_put_cstring("x11");
1.113 markus 1183: packet_put_int(nc->self);
1.149 markus 1184: packet_put_int(nc->local_window_max);
1185: packet_put_int(nc->local_maxpacket);
1.85 markus 1186: /* originator ipaddr and port */
1187: packet_put_cstring(remote_ipaddr);
1.57 markus 1188: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1189: debug2("ssh2 x11 bug compat mode");
1.57 markus 1190: } else {
1191: packet_put_int(remote_port);
1192: }
1.51 markus 1193: packet_send();
1194: } else {
1195: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1196: packet_put_int(nc->self);
1.121 markus 1197: if (packet_get_protocol_flags() &
1198: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1199: packet_put_cstring(buf);
1.51 markus 1200: packet_send();
1201: }
1.85 markus 1202: xfree(remote_ipaddr);
1.41 markus 1203: }
1204: }
1.25 markus 1205:
1.127 itojun 1206: static void
1.103 markus 1207: port_open_helper(Channel *c, char *rtype)
1208: {
1209: int direct;
1210: char buf[1024];
1211: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1212: int remote_port = get_peer_port(c->sock);
1.103 markus 1213:
1214: direct = (strcmp(rtype, "direct-tcpip") == 0);
1215:
1216: snprintf(buf, sizeof buf,
1217: "%s: listening port %d for %.100s port %d, "
1218: "connect from %.200s port %d",
1219: rtype, c->listening_port, c->path, c->host_port,
1220: remote_ipaddr, remote_port);
1221:
1222: xfree(c->remote_name);
1223: c->remote_name = xstrdup(buf);
1224:
1225: if (compat20) {
1226: packet_start(SSH2_MSG_CHANNEL_OPEN);
1227: packet_put_cstring(rtype);
1228: packet_put_int(c->self);
1229: packet_put_int(c->local_window_max);
1230: packet_put_int(c->local_maxpacket);
1231: if (direct) {
1232: /* target host, port */
1233: packet_put_cstring(c->path);
1234: packet_put_int(c->host_port);
1235: } else {
1236: /* listen address, port */
1237: packet_put_cstring(c->path);
1238: packet_put_int(c->listening_port);
1239: }
1240: /* originator host and port */
1241: packet_put_cstring(remote_ipaddr);
1.216 markus 1242: packet_put_int((u_int)remote_port);
1.103 markus 1243: packet_send();
1244: } else {
1245: packet_start(SSH_MSG_PORT_OPEN);
1246: packet_put_int(c->self);
1247: packet_put_cstring(c->path);
1248: packet_put_int(c->host_port);
1.121 markus 1249: if (packet_get_protocol_flags() &
1250: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1251: packet_put_cstring(c->remote_name);
1252: packet_send();
1253: }
1254: xfree(remote_ipaddr);
1255: }
1256:
1.226 djm 1257: static void
1258: channel_set_reuseaddr(int fd)
1259: {
1260: int on = 1;
1261:
1262: /*
1263: * Set socket options.
1264: * Allow local port reuse in TIME_WAIT.
1265: */
1266: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1267: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1268: }
1269:
1.41 markus 1270: /*
1271: * This socket is listening for connections to a forwarded TCP/IP port.
1272: */
1.127 itojun 1273: static void
1.237 deraadt 1274: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1275: {
1.103 markus 1276: Channel *nc;
1.41 markus 1277: struct sockaddr addr;
1.113 markus 1278: int newsock, nextstate;
1.41 markus 1279: socklen_t addrlen;
1.103 markus 1280: char *rtype;
1.73 markus 1281:
1.41 markus 1282: if (FD_ISSET(c->sock, readset)) {
1283: debug("Connection to port %d forwarding "
1284: "to %.100s port %d requested.",
1285: c->listening_port, c->path, c->host_port);
1.103 markus 1286:
1.137 markus 1287: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1288: nextstate = SSH_CHANNEL_OPENING;
1289: rtype = "forwarded-tcpip";
1290: } else {
1291: if (c->host_port == 0) {
1292: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1293: rtype = "dynamic-tcpip";
1.137 markus 1294: } else {
1295: nextstate = SSH_CHANNEL_OPENING;
1296: rtype = "direct-tcpip";
1297: }
1298: }
1.103 markus 1299:
1.41 markus 1300: addrlen = sizeof(addr);
1301: newsock = accept(c->sock, &addr, &addrlen);
1302: if (newsock < 0) {
1303: error("accept: %.100s", strerror(errno));
1304: return;
1305: }
1.169 stevesk 1306: set_nodelay(newsock);
1.190 markus 1307: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1308: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1309: nc->listening_port = c->listening_port;
1310: nc->host_port = c->host_port;
1311: strlcpy(nc->path, c->path, sizeof(nc->path));
1312:
1.137 markus 1313: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1314: /*
1315: * do not call the channel_post handler until
1316: * this flag has been reset by a pre-handler.
1317: * otherwise the FD_ISSET calls might overflow
1318: */
1319: nc->delayed = 1;
1320: } else {
1.103 markus 1321: port_open_helper(nc, rtype);
1.137 markus 1322: }
1.41 markus 1323: }
1324: }
1.25 markus 1325:
1.41 markus 1326: /*
1327: * This is the authentication agent socket listening for connections from
1328: * clients.
1329: */
1.127 itojun 1330: static void
1.237 deraadt 1331: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1332: {
1.113 markus 1333: Channel *nc;
1334: int newsock;
1.41 markus 1335: struct sockaddr addr;
1336: socklen_t addrlen;
1.25 markus 1337:
1.41 markus 1338: if (FD_ISSET(c->sock, readset)) {
1339: addrlen = sizeof(addr);
1340: newsock = accept(c->sock, &addr, &addrlen);
1341: if (newsock < 0) {
1342: error("accept from auth socket: %.100s", strerror(errno));
1343: return;
1344: }
1.113 markus 1345: nc = channel_new("accepted auth socket",
1.73 markus 1346: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1347: c->local_window_max, c->local_maxpacket,
1.190 markus 1348: 0, "accepted auth socket", 1);
1.73 markus 1349: if (compat20) {
1350: packet_start(SSH2_MSG_CHANNEL_OPEN);
1351: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1352: packet_put_int(nc->self);
1.73 markus 1353: packet_put_int(c->local_window_max);
1354: packet_put_int(c->local_maxpacket);
1355: } else {
1356: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1357: packet_put_int(nc->self);
1.73 markus 1358: }
1.41 markus 1359: packet_send();
1360: }
1361: }
1.25 markus 1362:
1.127 itojun 1363: static void
1.237 deraadt 1364: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1365: {
1.114 markus 1366: int err = 0;
1.129 stevesk 1367: socklen_t sz = sizeof(err);
1.114 markus 1368:
1.75 markus 1369: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1370: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1371: err = errno;
1372: error("getsockopt SO_ERROR failed");
1373: }
1374: if (err == 0) {
1375: debug("channel %d: connected", c->self);
1376: c->type = SSH_CHANNEL_OPEN;
1377: if (compat20) {
1378: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1379: packet_put_int(c->remote_id);
1380: packet_put_int(c->self);
1381: packet_put_int(c->local_window);
1382: packet_put_int(c->local_maxpacket);
1383: } else {
1384: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1385: packet_put_int(c->remote_id);
1386: packet_put_int(c->self);
1387: }
1.75 markus 1388: } else {
1.114 markus 1389: debug("channel %d: not connected: %s",
1390: c->self, strerror(err));
1391: if (compat20) {
1392: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1393: packet_put_int(c->remote_id);
1394: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1395: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1396: packet_put_cstring(strerror(err));
1397: packet_put_cstring("");
1398: }
1.75 markus 1399: } else {
1.114 markus 1400: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1401: packet_put_int(c->remote_id);
1.75 markus 1402: }
1.114 markus 1403: chan_mark_dead(c);
1.75 markus 1404: }
1.114 markus 1405: packet_send();
1.75 markus 1406: }
1407: }
1408:
1.127 itojun 1409: static int
1.237 deraadt 1410: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1411: {
1.214 markus 1412: char buf[CHAN_RBUF];
1.41 markus 1413: int len;
1.25 markus 1414:
1.118 markus 1415: if (c->rfd != -1 &&
1.41 markus 1416: FD_ISSET(c->rfd, readset)) {
1417: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1418: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1419: return 1;
1.41 markus 1420: if (len <= 0) {
1.194 markus 1421: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1422: c->self, c->rfd, len);
1.104 markus 1423: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1424: debug2("channel %d: not open", c->self);
1.113 markus 1425: chan_mark_dead(c);
1.103 markus 1426: return -1;
1.104 markus 1427: } else if (compat13) {
1.158 markus 1428: buffer_clear(&c->output);
1.41 markus 1429: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1430: debug2("channel %d: input draining.", c->self);
1.25 markus 1431: } else {
1.41 markus 1432: chan_read_failed(c);
1.25 markus 1433: }
1.41 markus 1434: return -1;
1435: }
1.143 deraadt 1436: if (c->input_filter != NULL) {
1.66 markus 1437: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1438: debug2("channel %d: filter stops", c->self);
1.65 markus 1439: chan_read_failed(c);
1440: }
1.228 reyk 1441: } else if (c->datagram) {
1442: buffer_put_string(&c->input, buf, len);
1.65 markus 1443: } else {
1444: buffer_append(&c->input, buf, len);
1445: }
1.41 markus 1446: }
1447: return 1;
1448: }
1.241 deraadt 1449:
1.127 itojun 1450: static int
1.237 deraadt 1451: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1452: {
1.95 markus 1453: struct termios tio;
1.231 reyk 1454: u_char *data = NULL, *buf;
1.134 markus 1455: u_int dlen;
1.41 markus 1456: int len;
1.25 markus 1457:
1.41 markus 1458: /* Send buffered output data to the socket. */
1.118 markus 1459: if (c->wfd != -1 &&
1.41 markus 1460: FD_ISSET(c->wfd, writeset) &&
1461: buffer_len(&c->output) > 0) {
1.231 reyk 1462: if (c->output_filter != NULL) {
1463: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1464: debug2("channel %d: filter stops", c->self);
1.232 reyk 1465: if (c->type != SSH_CHANNEL_OPEN)
1466: chan_mark_dead(c);
1467: else
1468: chan_write_failed(c);
1469: return -1;
1.231 reyk 1470: }
1471: } else if (c->datagram) {
1472: buf = data = buffer_get_string(&c->output, &dlen);
1473: } else {
1474: buf = data = buffer_ptr(&c->output);
1475: dlen = buffer_len(&c->output);
1476: }
1477:
1.228 reyk 1478: if (c->datagram) {
1479: /* ignore truncated writes, datagrams might get lost */
1480: c->local_consumed += dlen + 4;
1.231 reyk 1481: len = write(c->wfd, buf, dlen);
1.228 reyk 1482: xfree(data);
1483: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1484: return 1;
1485: if (len <= 0) {
1486: if (c->type != SSH_CHANNEL_OPEN)
1487: chan_mark_dead(c);
1488: else
1489: chan_write_failed(c);
1490: return -1;
1491: }
1492: return 1;
1493: }
1.231 reyk 1494:
1495: len = write(c->wfd, buf, dlen);
1.53 markus 1496: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1497: return 1;
1.41 markus 1498: if (len <= 0) {
1.104 markus 1499: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1500: debug2("channel %d: not open", c->self);
1.113 markus 1501: chan_mark_dead(c);
1.104 markus 1502: return -1;
1503: } else if (compat13) {
1.158 markus 1504: buffer_clear(&c->output);
1.194 markus 1505: debug2("channel %d: input draining.", c->self);
1.41 markus 1506: c->type = SSH_CHANNEL_INPUT_DRAINING;
1507: } else {
1508: chan_write_failed(c);
1509: }
1510: return -1;
1.91 markus 1511: }
1.231 reyk 1512: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1513: if (tcgetattr(c->wfd, &tio) == 0 &&
1514: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1515: /*
1516: * Simulate echo to reduce the impact of
1.96 markus 1517: * traffic analysis. We need to match the
1.95 markus 1518: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1519: * (4 byte channel id + buf)
1.91 markus 1520: */
1.95 markus 1521: packet_send_ignore(4 + len);
1.91 markus 1522: packet_send();
1523: }
1.25 markus 1524: }
1.41 markus 1525: buffer_consume(&c->output, len);
1.44 markus 1526: if (compat20 && len > 0) {
1527: c->local_consumed += len;
1528: }
1529: }
1530: return 1;
1531: }
1.241 deraadt 1532:
1.127 itojun 1533: static int
1.237 deraadt 1534: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1535: {
1.214 markus 1536: char buf[CHAN_RBUF];
1.44 markus 1537: int len;
1538:
1.45 markus 1539: /** XXX handle drain efd, too */
1.44 markus 1540: if (c->efd != -1) {
1541: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1542: FD_ISSET(c->efd, writeset) &&
1543: buffer_len(&c->extended) > 0) {
1544: len = write(c->efd, buffer_ptr(&c->extended),
1545: buffer_len(&c->extended));
1.70 markus 1546: debug2("channel %d: written %d to efd %d",
1.44 markus 1547: c->self, len, c->efd);
1.93 markus 1548: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1549: return 1;
1550: if (len <= 0) {
1551: debug2("channel %d: closing write-efd %d",
1552: c->self, c->efd);
1.132 markus 1553: channel_close_fd(&c->efd);
1.93 markus 1554: } else {
1.44 markus 1555: buffer_consume(&c->extended, len);
1556: c->local_consumed += len;
1557: }
1558: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1559: FD_ISSET(c->efd, readset)) {
1560: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1561: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1562: c->self, len, c->efd);
1.93 markus 1563: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1564: return 1;
1565: if (len <= 0) {
1566: debug2("channel %d: closing read-efd %d",
1.45 markus 1567: c->self, c->efd);
1.132 markus 1568: channel_close_fd(&c->efd);
1.93 markus 1569: } else {
1.44 markus 1570: buffer_append(&c->extended, buf, len);
1.93 markus 1571: }
1.44 markus 1572: }
1573: }
1574: return 1;
1575: }
1.241 deraadt 1576:
1.127 itojun 1577: static int
1.237 deraadt 1578: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1579: {
1580: char buf[16];
1581: int len;
1582:
1583: /* Monitor control fd to detect if the slave client exits */
1584: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1585: len = read(c->ctl_fd, buf, sizeof(buf));
1586: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1587: return 1;
1588: if (len <= 0) {
1589: debug2("channel %d: ctl read<=0", c->self);
1590: if (c->type != SSH_CHANNEL_OPEN) {
1591: debug2("channel %d: not open", c->self);
1592: chan_mark_dead(c);
1593: return -1;
1594: } else {
1595: chan_read_failed(c);
1596: chan_write_failed(c);
1597: }
1598: return -1;
1599: } else
1600: fatal("%s: unexpected data on ctl fd", __func__);
1601: }
1602: return 1;
1603: }
1.241 deraadt 1604:
1.204 djm 1605: static int
1.93 markus 1606: channel_check_window(Channel *c)
1.44 markus 1607: {
1.104 markus 1608: if (c->type == SSH_CHANNEL_OPEN &&
1609: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1610: c->local_window < c->local_window_max/2 &&
1611: c->local_consumed > 0) {
1612: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1613: packet_put_int(c->remote_id);
1614: packet_put_int(c->local_consumed);
1615: packet_send();
1.70 markus 1616: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1617: c->self, c->local_window,
1618: c->local_consumed);
1619: c->local_window += c->local_consumed;
1620: c->local_consumed = 0;
1.1 deraadt 1621: }
1.41 markus 1622: return 1;
1.1 deraadt 1623: }
1624:
1.127 itojun 1625: static void
1.237 deraadt 1626: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1627: {
1.137 markus 1628: if (c->delayed)
1629: return;
1.41 markus 1630: channel_handle_rfd(c, readset, writeset);
1631: channel_handle_wfd(c, readset, writeset);
1.157 markus 1632: if (!compat20)
1.137 markus 1633: return;
1.44 markus 1634: channel_handle_efd(c, readset, writeset);
1.204 djm 1635: channel_handle_ctl(c, readset, writeset);
1.93 markus 1636: channel_check_window(c);
1.44 markus 1637: }
1638:
1.127 itojun 1639: static void
1.237 deraadt 1640: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1641: {
1.41 markus 1642: int len;
1.180 deraadt 1643:
1.41 markus 1644: /* Send buffered output data to the socket. */
1645: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1646: len = write(c->sock, buffer_ptr(&c->output),
1647: buffer_len(&c->output));
1648: if (len <= 0)
1.158 markus 1649: buffer_clear(&c->output);
1.41 markus 1650: else
1651: buffer_consume(&c->output, len);
1652: }
1653: }
1.25 markus 1654:
1.127 itojun 1655: static void
1.44 markus 1656: channel_handler_init_20(void)
1657: {
1.157 markus 1658: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1659: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1660: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1661: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1662: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1663: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1664: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1665: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1666:
1.157 markus 1667: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1668: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1669: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1670: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1671: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1672: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1673: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1674: }
1675:
1.127 itojun 1676: static void
1.41 markus 1677: channel_handler_init_13(void)
1678: {
1679: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1680: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1681: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1682: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1683: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1684: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1685: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1686: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1687: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1688:
1.157 markus 1689: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1690: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1691: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1692: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1693: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1694: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1695: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1696: }
1.25 markus 1697:
1.127 itojun 1698: static void
1.41 markus 1699: channel_handler_init_15(void)
1700: {
1.157 markus 1701: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1702: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1703: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1704: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1705: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1706: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1707: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1708:
1.41 markus 1709: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1710: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1711: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1712: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1713: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1714: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1715: }
1.27 markus 1716:
1.127 itojun 1717: static void
1.41 markus 1718: channel_handler_init(void)
1719: {
1720: int i;
1.180 deraadt 1721:
1.148 deraadt 1722: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1723: channel_pre[i] = NULL;
1724: channel_post[i] = NULL;
1725: }
1.44 markus 1726: if (compat20)
1727: channel_handler_init_20();
1728: else if (compat13)
1.41 markus 1729: channel_handler_init_13();
1730: else
1731: channel_handler_init_15();
1732: }
1.25 markus 1733:
1.140 markus 1734: /* gc dead channels */
1735: static void
1736: channel_garbage_collect(Channel *c)
1737: {
1738: if (c == NULL)
1739: return;
1740: if (c->detach_user != NULL) {
1.225 djm 1741: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1742: return;
1.194 markus 1743: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1744: c->detach_user(c->self, NULL);
1745: /* if we still have a callback */
1746: if (c->detach_user != NULL)
1747: return;
1.194 markus 1748: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1749: }
1750: if (!chan_is_dead(c, 1))
1751: return;
1.194 markus 1752: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1753: channel_free(c);
1754: }
1755:
1.127 itojun 1756: static void
1.237 deraadt 1757: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1758: {
1759: static int did_init = 0;
1.209 avsm 1760: u_int i;
1.41 markus 1761: Channel *c;
1.25 markus 1762:
1.41 markus 1763: if (!did_init) {
1764: channel_handler_init();
1765: did_init = 1;
1766: }
1767: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1768: c = channels[i];
1769: if (c == NULL)
1.41 markus 1770: continue;
1.118 markus 1771: if (ftab[c->type] != NULL)
1772: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1773: channel_garbage_collect(c);
1.1 deraadt 1774: }
1775: }
1776:
1.121 markus 1777: /*
1778: * Allocate/update select bitmasks and add any bits relevant to channels in
1779: * select bitmasks.
1780: */
1.49 markus 1781: void
1.100 markus 1782: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1783: u_int *nallocp, int rekeying)
1.41 markus 1784: {
1.243 djm 1785: u_int n, sz, nfdset;
1.84 markus 1786:
1787: n = MAX(*maxfdp, channel_max_fd);
1788:
1.243 djm 1789: nfdset = howmany(n+1, NFDBITS);
1790: /* Explicitly test here, because xrealloc isn't always called */
1791: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1792: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1793: sz = nfdset * sizeof(fd_mask);
1794:
1.132 markus 1795: /* perhaps check sz < nalloc/2 and shrink? */
1796: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1797: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1798: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1799: *nallocp = sz;
1.84 markus 1800: }
1.132 markus 1801: *maxfdp = n;
1.84 markus 1802: memset(*readsetp, 0, sz);
1803: memset(*writesetp, 0, sz);
1804:
1.100 markus 1805: if (!rekeying)
1806: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1807: }
1808:
1.121 markus 1809: /*
1810: * After select, perform any appropriate operations for channels which have
1811: * events pending.
1812: */
1.49 markus 1813: void
1.237 deraadt 1814: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1815: {
1816: channel_handler(channel_post, readset, writeset);
1817: }
1818:
1.121 markus 1819:
1.84 markus 1820: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1821: void
1.142 itojun 1822: channel_output_poll(void)
1.1 deraadt 1823: {
1.41 markus 1824: Channel *c;
1.209 avsm 1825: u_int i, len;
1.1 deraadt 1826:
1.25 markus 1827: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1828: c = channels[i];
1829: if (c == NULL)
1830: continue;
1.37 markus 1831:
1.121 markus 1832: /*
1833: * We are only interested in channels that can have buffered
1834: * incoming data.
1835: */
1.37 markus 1836: if (compat13) {
1.41 markus 1837: if (c->type != SSH_CHANNEL_OPEN &&
1838: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1839: continue;
1840: } else {
1.41 markus 1841: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1842: continue;
1843: }
1.46 markus 1844: if (compat20 &&
1845: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1846: /* XXX is this true? */
1.140 markus 1847: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1848: continue;
1849: }
1.25 markus 1850:
1851: /* Get the amount of buffered data for this channel. */
1.93 markus 1852: if ((c->istate == CHAN_INPUT_OPEN ||
1853: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1854: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1855: if (c->datagram) {
1856: if (len > 0) {
1857: u_char *data;
1858: u_int dlen;
1859:
1860: data = buffer_get_string(&c->input,
1861: &dlen);
1862: packet_start(SSH2_MSG_CHANNEL_DATA);
1863: packet_put_int(c->remote_id);
1864: packet_put_string(data, dlen);
1865: packet_send();
1866: c->remote_window -= dlen + 4;
1867: xfree(data);
1868: }
1869: continue;
1870: }
1.121 markus 1871: /*
1872: * Send some data for the other side over the secure
1873: * connection.
1874: */
1.44 markus 1875: if (compat20) {
1876: if (len > c->remote_window)
1877: len = c->remote_window;
1878: if (len > c->remote_maxpacket)
1879: len = c->remote_maxpacket;
1.25 markus 1880: } else {
1.44 markus 1881: if (packet_is_interactive()) {
1882: if (len > 1024)
1883: len = 512;
1884: } else {
1885: /* Keep the packets at reasonable size. */
1886: if (len > packet_get_maxsize()/2)
1887: len = packet_get_maxsize()/2;
1888: }
1.25 markus 1889: }
1.41 markus 1890: if (len > 0) {
1.44 markus 1891: packet_start(compat20 ?
1892: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1893: packet_put_int(c->remote_id);
1894: packet_put_string(buffer_ptr(&c->input), len);
1895: packet_send();
1896: buffer_consume(&c->input, len);
1897: c->remote_window -= len;
1898: }
1899: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1900: if (compat13)
1901: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1902: /*
1903: * input-buffer is empty and read-socket shutdown:
1.172 markus 1904: * tell peer, that we will not send more data: send IEOF.
1905: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1906: */
1.172 markus 1907: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1908: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1909: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1910: else
1911: chan_ibuf_empty(c);
1.25 markus 1912: }
1.44 markus 1913: /* Send extended data, i.e. stderr */
1914: if (compat20 &&
1.172 markus 1915: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1916: c->remote_window > 0 &&
1917: (len = buffer_len(&c->extended)) > 0 &&
1918: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1919: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1920: c->self, c->remote_window, buffer_len(&c->extended),
1921: c->extended_usage);
1.44 markus 1922: if (len > c->remote_window)
1923: len = c->remote_window;
1924: if (len > c->remote_maxpacket)
1925: len = c->remote_maxpacket;
1926: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1927: packet_put_int(c->remote_id);
1928: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1929: packet_put_string(buffer_ptr(&c->extended), len);
1930: packet_send();
1931: buffer_consume(&c->extended, len);
1932: c->remote_window -= len;
1.93 markus 1933: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1934: }
1.25 markus 1935: }
1.1 deraadt 1936: }
1937:
1.121 markus 1938:
1939: /* -- protocol input */
1.249 djm 1940:
1941: /* ARGSUSED */
1.49 markus 1942: void
1.154 markus 1943: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1944: {
1.37 markus 1945: int id;
1.25 markus 1946: char *data;
1.77 markus 1947: u_int data_len;
1.41 markus 1948: Channel *c;
1.25 markus 1949:
1950: /* Get the channel number and verify it. */
1.37 markus 1951: id = packet_get_int();
1.41 markus 1952: c = channel_lookup(id);
1953: if (c == NULL)
1.37 markus 1954: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1955:
1956: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1957: if (c->type != SSH_CHANNEL_OPEN &&
1958: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1959: return;
1960:
1.25 markus 1961: /* Get the data. */
1962: data = packet_get_string(&data_len);
1.200 markus 1963:
1964: /*
1965: * Ignore data for protocol > 1.3 if output end is no longer open.
1966: * For protocol 2 the sending side is reducing its window as it sends
1967: * data, so we must 'fake' consumption of the data in order to ensure
1968: * that window updates are sent back. Otherwise the connection might
1969: * deadlock.
1970: */
1971: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1972: if (compat20) {
1973: c->local_window -= data_len;
1974: c->local_consumed += data_len;
1975: }
1976: xfree(data);
1977: return;
1978: }
1.41 markus 1979:
1.143 deraadt 1980: if (compat20) {
1.44 markus 1981: if (data_len > c->local_maxpacket) {
1.188 itojun 1982: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1983: c->self, data_len, c->local_maxpacket);
1984: }
1985: if (data_len > c->local_window) {
1.188 itojun 1986: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1987: c->self, data_len, c->local_window);
1988: xfree(data);
1989: return;
1990: }
1991: c->local_window -= data_len;
1992: }
1.152 markus 1993: packet_check_eom();
1.228 reyk 1994: if (c->datagram)
1995: buffer_put_string(&c->output, data, data_len);
1996: else
1997: buffer_append(&c->output, data, data_len);
1.25 markus 1998: xfree(data);
1.1 deraadt 1999: }
1.121 markus 2000:
1.249 djm 2001: /* ARGSUSED */
1.49 markus 2002: void
1.154 markus 2003: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2004: {
2005: int id;
2006: char *data;
1.177 markus 2007: u_int data_len, tcode;
1.44 markus 2008: Channel *c;
2009:
2010: /* Get the channel number and verify it. */
2011: id = packet_get_int();
2012: c = channel_lookup(id);
2013:
2014: if (c == NULL)
2015: packet_disconnect("Received extended_data for bad channel %d.", id);
2016: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2017: logit("channel %d: ext data for non open", id);
1.44 markus 2018: return;
1.172 markus 2019: }
2020: if (c->flags & CHAN_EOF_RCVD) {
2021: if (datafellows & SSH_BUG_EXTEOF)
2022: debug("channel %d: accepting ext data after eof", id);
2023: else
2024: packet_disconnect("Received extended_data after EOF "
2025: "on channel %d.", id);
1.44 markus 2026: }
2027: tcode = packet_get_int();
2028: if (c->efd == -1 ||
2029: c->extended_usage != CHAN_EXTENDED_WRITE ||
2030: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2031: logit("channel %d: bad ext data", c->self);
1.44 markus 2032: return;
2033: }
2034: data = packet_get_string(&data_len);
1.152 markus 2035: packet_check_eom();
1.44 markus 2036: if (data_len > c->local_window) {
1.188 itojun 2037: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2038: c->self, data_len, c->local_window);
2039: xfree(data);
2040: return;
2041: }
1.70 markus 2042: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2043: c->local_window -= data_len;
2044: buffer_append(&c->extended, data, data_len);
2045: xfree(data);
2046: }
2047:
1.249 djm 2048: /* ARGSUSED */
1.49 markus 2049: void
1.154 markus 2050: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2051: {
2052: int id;
2053: Channel *c;
2054:
2055: id = packet_get_int();
1.152 markus 2056: packet_check_eom();
1.41 markus 2057: c = channel_lookup(id);
2058: if (c == NULL)
2059: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2060: chan_rcvd_ieof(c);
1.133 markus 2061:
2062: /* XXX force input close */
1.156 markus 2063: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2064: debug("channel %d: FORCE input drain", c->self);
2065: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2066: if (buffer_len(&c->input) == 0)
2067: chan_ibuf_empty(c);
1.133 markus 2068: }
2069:
1.41 markus 2070: }
1.1 deraadt 2071:
1.249 djm 2072: /* ARGSUSED */
1.49 markus 2073: void
1.154 markus 2074: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2075: {
1.41 markus 2076: int id;
2077: Channel *c;
1.1 deraadt 2078:
1.41 markus 2079: id = packet_get_int();
1.152 markus 2080: packet_check_eom();
1.41 markus 2081: c = channel_lookup(id);
2082: if (c == NULL)
2083: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2084:
2085: /*
2086: * Send a confirmation that we have closed the channel and no more
2087: * data is coming for it.
2088: */
1.25 markus 2089: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2090: packet_put_int(c->remote_id);
1.25 markus 2091: packet_send();
2092:
1.27 markus 2093: /*
2094: * If the channel is in closed state, we have sent a close request,
2095: * and the other side will eventually respond with a confirmation.
2096: * Thus, we cannot free the channel here, because then there would be
2097: * no-one to receive the confirmation. The channel gets freed when
2098: * the confirmation arrives.
2099: */
1.41 markus 2100: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2101: /*
2102: * Not a closed channel - mark it as draining, which will
2103: * cause it to be freed later.
2104: */
1.158 markus 2105: buffer_clear(&c->input);
1.41 markus 2106: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2107: }
1.1 deraadt 2108: }
2109:
1.41 markus 2110: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2111: /* ARGSUSED */
1.49 markus 2112: void
1.154 markus 2113: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2114: {
2115: int id = packet_get_int();
2116: Channel *c = channel_lookup(id);
1.151 markus 2117:
1.152 markus 2118: packet_check_eom();
1.41 markus 2119: if (c == NULL)
2120: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2121: chan_rcvd_oclose(c);
2122: }
1.1 deraadt 2123:
1.249 djm 2124: /* ARGSUSED */
1.49 markus 2125: void
1.154 markus 2126: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2127: {
1.41 markus 2128: int id = packet_get_int();
2129: Channel *c = channel_lookup(id);
1.1 deraadt 2130:
1.152 markus 2131: packet_check_eom();
1.41 markus 2132: if (c == NULL)
2133: packet_disconnect("Received close confirmation for "
2134: "out-of-range channel %d.", id);
2135: if (c->type != SSH_CHANNEL_CLOSED)
2136: packet_disconnect("Received close confirmation for "
2137: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2138: channel_free(c);
1.1 deraadt 2139: }
2140:
1.249 djm 2141: /* ARGSUSED */
1.49 markus 2142: void
1.154 markus 2143: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2144: {
1.41 markus 2145: int id, remote_id;
2146: Channel *c;
1.1 deraadt 2147:
1.41 markus 2148: id = packet_get_int();
2149: c = channel_lookup(id);
1.25 markus 2150:
1.41 markus 2151: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2152: packet_disconnect("Received open confirmation for "
2153: "non-opening channel %d.", id);
2154: remote_id = packet_get_int();
1.27 markus 2155: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2156: c->remote_id = remote_id;
2157: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2158:
2159: if (compat20) {
2160: c->remote_window = packet_get_int();
2161: c->remote_maxpacket = packet_get_int();
1.165 markus 2162: if (c->confirm) {
1.70 markus 2163: debug2("callback start");
1.204 djm 2164: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2165: debug2("callback done");
1.44 markus 2166: }
1.194 markus 2167: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2168: c->remote_window, c->remote_maxpacket);
2169: }
1.152 markus 2170: packet_check_eom();
1.1 deraadt 2171: }
2172:
1.127 itojun 2173: static char *
1.114 markus 2174: reason2txt(int reason)
2175: {
1.143 deraadt 2176: switch (reason) {
1.114 markus 2177: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2178: return "administratively prohibited";
2179: case SSH2_OPEN_CONNECT_FAILED:
2180: return "connect failed";
2181: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2182: return "unknown channel type";
2183: case SSH2_OPEN_RESOURCE_SHORTAGE:
2184: return "resource shortage";
2185: }
1.117 stevesk 2186: return "unknown reason";
1.114 markus 2187: }
2188:
1.249 djm 2189: /* ARGSUSED */
1.49 markus 2190: void
1.154 markus 2191: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2192: {
1.86 markus 2193: int id, reason;
2194: char *msg = NULL, *lang = NULL;
1.41 markus 2195: Channel *c;
2196:
2197: id = packet_get_int();
2198: c = channel_lookup(id);
1.25 markus 2199:
1.41 markus 2200: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2201: packet_disconnect("Received open failure for "
2202: "non-opening channel %d.", id);
1.44 markus 2203: if (compat20) {
1.86 markus 2204: reason = packet_get_int();
1.110 markus 2205: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2206: msg = packet_get_string(NULL);
2207: lang = packet_get_string(NULL);
2208: }
1.188 itojun 2209: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2210: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2211: if (msg != NULL)
2212: xfree(msg);
2213: if (lang != NULL)
2214: xfree(lang);
1.44 markus 2215: }
1.152 markus 2216: packet_check_eom();
1.25 markus 2217: /* Free the channel. This will also close the socket. */
1.113 markus 2218: channel_free(c);
1.44 markus 2219: }
2220:
1.249 djm 2221: /* ARGSUSED */
1.121 markus 2222: void
1.154 markus 2223: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2224: {
2225: Channel *c;
1.178 markus 2226: int id;
2227: u_int adjust;
1.121 markus 2228:
2229: if (!compat20)
2230: return;
2231:
2232: /* Get the channel number and verify it. */
2233: id = packet_get_int();
2234: c = channel_lookup(id);
1.1 deraadt 2235:
1.229 markus 2236: if (c == NULL) {
2237: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2238: return;
2239: }
2240: adjust = packet_get_int();
1.152 markus 2241: packet_check_eom();
1.178 markus 2242: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2243: c->remote_window += adjust;
2244: }
1.1 deraadt 2245:
1.249 djm 2246: /* ARGSUSED */
1.121 markus 2247: void
1.154 markus 2248: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2249: {
1.121 markus 2250: Channel *c = NULL;
2251: u_short host_port;
2252: char *host, *originator_string;
2253: int remote_id, sock = -1;
2254:
2255: remote_id = packet_get_int();
2256: host = packet_get_string(NULL);
2257: host_port = packet_get_int();
1.25 markus 2258:
1.121 markus 2259: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2260: originator_string = packet_get_string(NULL);
2261: } else {
2262: originator_string = xstrdup("unknown (remote did not supply name)");
2263: }
1.152 markus 2264: packet_check_eom();
1.121 markus 2265: sock = channel_connect_to(host, host_port);
2266: if (sock != -1) {
2267: c = channel_new("connected socket",
2268: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2269: originator_string, 1);
1.167 markus 2270: c->remote_id = remote_id;
1.25 markus 2271: }
1.190 markus 2272: xfree(originator_string);
1.121 markus 2273: if (c == NULL) {
2274: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2275: packet_put_int(remote_id);
2276: packet_send();
2277: }
2278: xfree(host);
1.1 deraadt 2279: }
2280:
1.121 markus 2281:
2282: /* -- tcp forwarding */
1.135 markus 2283:
2284: void
2285: channel_set_af(int af)
2286: {
2287: IPv4or6 = af;
2288: }
1.121 markus 2289:
1.160 markus 2290: static int
2291: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2292: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2293: {
1.113 markus 2294: Channel *c;
1.226 djm 2295: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2296: struct addrinfo hints, *ai, *aitop;
1.212 djm 2297: const char *host, *addr;
1.35 markus 2298: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2299:
1.160 markus 2300: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2301: listen_addr : host_to_connect;
1.212 djm 2302: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2303:
1.160 markus 2304: if (host == NULL) {
2305: error("No forward host name.");
1.218 markus 2306: return 0;
1.73 markus 2307: }
1.113 markus 2308: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2309: error("Forward host name too long.");
1.218 markus 2310: return 0;
1.87 markus 2311: }
1.25 markus 2312:
1.28 markus 2313: /*
1.212 djm 2314: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2315: * specified address or wildcard. On the client, a specified bind
2316: * address will always override gateway_ports. On the server, a
2317: * gateway_ports of 1 (``yes'') will override the client's
2318: * specification and force a wildcard bind, whereas a value of 2
2319: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2320: * asked for.
2321: *
2322: * Special-case listen_addrs are:
2323: *
2324: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2325: * "" (empty string), "*" -> wildcard v4/v6
2326: * "localhost" -> loopback v4/v6
2327: */
2328: addr = NULL;
2329: if (listen_addr == NULL) {
2330: /* No address specified: default to gateway_ports setting */
2331: if (gateway_ports)
2332: wildcard = 1;
2333: } else if (gateway_ports || is_client) {
2334: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2335: strcmp(listen_addr, "0.0.0.0") == 0) ||
2336: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2337: (!is_client && gateway_ports == 1))
2338: wildcard = 1;
2339: else if (strcmp(listen_addr, "localhost") != 0)
2340: addr = listen_addr;
2341: }
2342:
2343: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2344: type, wildcard, (addr == NULL) ? "NULL" : addr);
2345:
2346: /*
1.35 markus 2347: * getaddrinfo returns a loopback address if the hostname is
2348: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2349: */
1.35 markus 2350: memset(&hints, 0, sizeof(hints));
2351: hints.ai_family = IPv4or6;
1.212 djm 2352: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2353: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2354: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2355: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2356: if (addr == NULL) {
2357: /* This really shouldn't happen */
2358: packet_disconnect("getaddrinfo: fatal error: %s",
2359: gai_strerror(r));
2360: } else {
1.218 markus 2361: error("channel_setup_fwd_listener: "
1.212 djm 2362: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2363: }
1.218 markus 2364: return 0;
1.212 djm 2365: }
1.35 markus 2366:
2367: for (ai = aitop; ai; ai = ai->ai_next) {
2368: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2369: continue;
2370: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2371: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2372: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2373: continue;
2374: }
2375: /* Create a port to listen for the host. */
1.189 markus 2376: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2377: if (sock < 0) {
2378: /* this is no error since kernel may not support ipv6 */
2379: verbose("socket: %.100s", strerror(errno));
2380: continue;
2381: }
1.226 djm 2382:
2383: channel_set_reuseaddr(sock);
1.182 stevesk 2384:
1.35 markus 2385: debug("Local forwarding listening on %s port %s.", ntop, strport);
2386:
2387: /* Bind the socket to the address. */
2388: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2389: /* address can be in use ipv6 address is already bound */
2390: verbose("bind: %.100s", strerror(errno));
2391: close(sock);
2392: continue;
2393: }
2394: /* Start listening for connections on the socket. */
1.199 markus 2395: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2396: error("listen: %.100s", strerror(errno));
2397: close(sock);
2398: continue;
2399: }
2400: /* Allocate a channel number for the socket. */
1.121 markus 2401: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2402: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2403: 0, "port listener", 1);
1.113 markus 2404: strlcpy(c->path, host, sizeof(c->path));
2405: c->host_port = port_to_connect;
2406: c->listening_port = listen_port;
1.35 markus 2407: success = 1;
2408: }
2409: if (success == 0)
1.160 markus 2410: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2411: listen_port);
1.35 markus 2412: freeaddrinfo(aitop);
1.87 markus 2413: return success;
1.25 markus 2414: }
1.1 deraadt 2415:
1.202 djm 2416: int
2417: channel_cancel_rport_listener(const char *host, u_short port)
2418: {
1.209 avsm 2419: u_int i;
2420: int found = 0;
1.202 djm 2421:
1.213 deraadt 2422: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2423: Channel *c = channels[i];
2424:
2425: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2426: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2427: c->listening_port == port) {
1.210 djm 2428: debug2("%s: close channel %d", __func__, i);
1.202 djm 2429: channel_free(c);
2430: found = 1;
2431: }
2432: }
2433:
2434: return (found);
2435: }
2436:
1.160 markus 2437: /* protocol local port fwd, used by ssh (and sshd in v1) */
2438: int
1.212 djm 2439: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2440: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2441: {
2442: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2443: listen_host, listen_port, host_to_connect, port_to_connect,
2444: gateway_ports);
1.160 markus 2445: }
2446:
2447: /* protocol v2 remote port fwd, used by sshd */
2448: int
2449: channel_setup_remote_fwd_listener(const char *listen_address,
2450: u_short listen_port, int gateway_ports)
2451: {
2452: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2453: listen_address, listen_port, NULL, 0, gateway_ports);
2454: }
2455:
1.27 markus 2456: /*
2457: * Initiate forwarding of connections to port "port" on remote host through
2458: * the secure channel to host:port from local side.
2459: */
1.1 deraadt 2460:
1.49 markus 2461: void
1.212 djm 2462: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2463: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2464: {
1.153 markus 2465: int type, success = 0;
1.73 markus 2466:
1.25 markus 2467: /* Record locally that connection to this host/port is permitted. */
2468: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2469: fatal("channel_request_remote_forwarding: too many forwards");
2470:
2471: /* Send the forward request to the remote side. */
1.44 markus 2472: if (compat20) {
1.212 djm 2473: const char *address_to_bind;
2474: if (listen_host == NULL)
2475: address_to_bind = "localhost";
2476: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2477: address_to_bind = "";
2478: else
2479: address_to_bind = listen_host;
2480:
1.44 markus 2481: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2482: packet_put_cstring("tcpip-forward");
1.173 markus 2483: packet_put_char(1); /* boolean: want reply */
1.44 markus 2484: packet_put_cstring(address_to_bind);
2485: packet_put_int(listen_port);
1.73 markus 2486: packet_send();
2487: packet_write_wait();
2488: /* Assume that server accepts the request */
2489: success = 1;
1.44 markus 2490: } else {
2491: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2492: packet_put_int(listen_port);
2493: packet_put_cstring(host_to_connect);
1.44 markus 2494: packet_put_int(port_to_connect);
2495: packet_send();
2496: packet_write_wait();
1.73 markus 2497:
2498: /* Wait for response from the remote side. */
1.153 markus 2499: type = packet_read();
1.73 markus 2500: switch (type) {
2501: case SSH_SMSG_SUCCESS:
2502: success = 1;
2503: break;
2504: case SSH_SMSG_FAILURE:
1.188 itojun 2505: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2506: break;
2507: default:
2508: /* Unknown packet */
2509: packet_disconnect("Protocol error for port forward request:"
2510: "received packet type %d.", type);
2511: }
2512: }
2513: if (success) {
2514: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2515: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2516: permitted_opens[num_permitted_opens].listen_port = listen_port;
2517: num_permitted_opens++;
1.44 markus 2518: }
1.1 deraadt 2519: }
2520:
1.27 markus 2521: /*
1.208 deraadt 2522: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2523: * local side.
2524: */
2525: void
1.212 djm 2526: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2527: {
2528: int i;
2529:
2530: if (!compat20)
2531: return;
2532:
2533: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2534: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2535: permitted_opens[i].listen_port == port)
2536: break;
2537: }
2538: if (i >= num_permitted_opens) {
2539: debug("%s: requested forward not found", __func__);
2540: return;
2541: }
2542: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2543: packet_put_cstring("cancel-tcpip-forward");
2544: packet_put_char(0);
1.212 djm 2545: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2546: packet_put_int(port);
2547: packet_send();
2548:
2549: permitted_opens[i].listen_port = 0;
2550: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2551: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2552: permitted_opens[i].host_to_connect = NULL;
2553: }
2554:
2555: /*
1.27 markus 2556: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2557: * listening for the port, and sends back a success reply (or disconnect
2558: * message if there was an error). This never returns if there was an error.
2559: */
1.49 markus 2560: void
1.56 markus 2561: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2562: {
1.31 markus 2563: u_short port, host_port;
1.25 markus 2564: char *hostname;
1.1 deraadt 2565:
1.25 markus 2566: /* Get arguments from the packet. */
2567: port = packet_get_int();
2568: hostname = packet_get_string(NULL);
2569: host_port = packet_get_int();
2570:
1.27 markus 2571: /*
2572: * Check that an unprivileged user is not trying to forward a
2573: * privileged port.
2574: */
1.25 markus 2575: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2576: packet_disconnect(
2577: "Requested forwarding of port %d but user is not root.",
2578: port);
2579: if (host_port == 0)
2580: packet_disconnect("Dynamic forwarding denied.");
2581:
1.73 markus 2582: /* Initiate forwarding */
1.212 djm 2583: channel_setup_local_fwd_listener(NULL, port, hostname,
2584: host_port, gateway_ports);
1.25 markus 2585:
2586: /* Free the argument string. */
2587: xfree(hostname);
1.1 deraadt 2588: }
2589:
1.99 markus 2590: /*
2591: * Permits opening to any host/port if permitted_opens[] is empty. This is
2592: * usually called by the server, because the user could connect to any port
2593: * anyway, and the server has no way to know but to trust the client anyway.
2594: */
2595: void
1.142 itojun 2596: channel_permit_all_opens(void)
1.99 markus 2597: {
2598: if (num_permitted_opens == 0)
2599: all_opens_permitted = 1;
2600: }
2601:
1.101 markus 2602: void
1.99 markus 2603: channel_add_permitted_opens(char *host, int port)
2604: {
2605: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2606: fatal("channel_request_remote_forwarding: too many forwards");
2607: debug("allow port forwarding to host %s port %d", host, port);
2608:
2609: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2610: permitted_opens[num_permitted_opens].port_to_connect = port;
2611: num_permitted_opens++;
2612:
2613: all_opens_permitted = 0;
2614: }
2615:
1.101 markus 2616: void
1.99 markus 2617: channel_clear_permitted_opens(void)
2618: {
2619: int i;
2620:
2621: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2622: if (permitted_opens[i].host_to_connect != NULL)
2623: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2624: num_permitted_opens = 0;
2625:
2626: }
2627:
2628: /* return socket to remote host, port */
1.127 itojun 2629: static int
1.99 markus 2630: connect_to(const char *host, u_short port)
1.41 markus 2631: {
2632: struct addrinfo hints, *ai, *aitop;
2633: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2634: int gaierr;
2635: int sock = -1;
2636:
2637: memset(&hints, 0, sizeof(hints));
2638: hints.ai_family = IPv4or6;
2639: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2640: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2641: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2642: error("connect_to %.100s: unknown host (%s)", host,
2643: gai_strerror(gaierr));
1.41 markus 2644: return -1;
2645: }
2646: for (ai = aitop; ai; ai = ai->ai_next) {
2647: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2648: continue;
2649: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2650: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2651: error("connect_to: getnameinfo failed");
1.41 markus 2652: continue;
2653: }
1.189 markus 2654: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2655: if (sock < 0) {
1.186 djm 2656: if (ai->ai_next == NULL)
2657: error("socket: %.100s", strerror(errno));
2658: else
2659: verbose("socket: %.100s", strerror(errno));
1.41 markus 2660: continue;
2661: }
1.205 djm 2662: if (set_nonblock(sock) == -1)
2663: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2664: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2665: errno != EINPROGRESS) {
1.99 markus 2666: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2667: strerror(errno));
2668: close(sock);
1.89 stevesk 2669: continue; /* fail -- try next */
1.41 markus 2670: }
2671: break; /* success */
2672:
2673: }
2674: freeaddrinfo(aitop);
2675: if (!ai) {
1.99 markus 2676: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2677: return -1;
2678: }
2679: /* success */
1.169 stevesk 2680: set_nodelay(sock);
1.41 markus 2681: return sock;
2682: }
1.99 markus 2683:
1.73 markus 2684: int
1.130 stevesk 2685: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2686: {
2687: int i;
1.99 markus 2688:
1.73 markus 2689: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2690: if (permitted_opens[i].host_to_connect != NULL &&
2691: permitted_opens[i].listen_port == listen_port)
1.99 markus 2692: return connect_to(
1.73 markus 2693: permitted_opens[i].host_to_connect,
2694: permitted_opens[i].port_to_connect);
1.74 markus 2695: error("WARNING: Server requests forwarding for unknown listen_port %d",
2696: listen_port);
1.73 markus 2697: return -1;
2698: }
2699:
1.99 markus 2700: /* Check if connecting to that port is permitted and connect. */
2701: int
2702: channel_connect_to(const char *host, u_short port)
2703: {
2704: int i, permit;
2705:
2706: permit = all_opens_permitted;
2707: if (!permit) {
2708: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2709: if (permitted_opens[i].host_to_connect != NULL &&
2710: permitted_opens[i].port_to_connect == port &&
1.99 markus 2711: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2712: permit = 1;
2713:
2714: }
2715: if (!permit) {
1.188 itojun 2716: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2717: "but the request was denied.", host, port);
2718: return -1;
2719: }
2720: return connect_to(host, port);
1.204 djm 2721: }
2722:
2723: void
2724: channel_send_window_changes(void)
2725: {
1.209 avsm 2726: u_int i;
1.204 djm 2727: struct winsize ws;
2728:
2729: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2730: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2731: channels[i]->type != SSH_CHANNEL_OPEN)
2732: continue;
2733: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2734: continue;
2735: channel_request_start(i, "window-change", 0);
1.238 deraadt 2736: packet_put_int((u_int)ws.ws_col);
2737: packet_put_int((u_int)ws.ws_row);
2738: packet_put_int((u_int)ws.ws_xpixel);
2739: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2740: packet_send();
2741: }
1.99 markus 2742: }
2743:
1.121 markus 2744: /* -- X11 forwarding */
1.1 deraadt 2745:
1.27 markus 2746: /*
2747: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2748: * Returns 0 and a suitable display number for the DISPLAY variable
2749: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2750: */
1.141 stevesk 2751: int
1.163 stevesk 2752: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2753: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2754: {
1.149 markus 2755: Channel *nc = NULL;
1.31 markus 2756: int display_number, sock;
2757: u_short port;
1.35 markus 2758: struct addrinfo hints, *ai, *aitop;
2759: char strport[NI_MAXSERV];
2760: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2761:
1.224 markus 2762: if (chanids == NULL)
2763: return -1;
2764:
1.33 markus 2765: for (display_number = x11_display_offset;
1.148 deraadt 2766: display_number < MAX_DISPLAYS;
2767: display_number++) {
1.25 markus 2768: port = 6000 + display_number;
1.35 markus 2769: memset(&hints, 0, sizeof(hints));
2770: hints.ai_family = IPv4or6;
1.163 stevesk 2771: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2772: hints.ai_socktype = SOCK_STREAM;
2773: snprintf(strport, sizeof strport, "%d", port);
2774: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2775: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2776: return -1;
1.25 markus 2777: }
1.35 markus 2778: for (ai = aitop; ai; ai = ai->ai_next) {
2779: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2780: continue;
1.189 markus 2781: sock = socket(ai->ai_family, ai->ai_socktype,
2782: ai->ai_protocol);
1.35 markus 2783: if (sock < 0) {
2784: error("socket: %.100s", strerror(errno));
1.203 markus 2785: freeaddrinfo(aitop);
1.141 stevesk 2786: return -1;
1.35 markus 2787: }
1.226 djm 2788: channel_set_reuseaddr(sock);
1.35 markus 2789: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2790: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2791: close(sock);
1.183 itojun 2792:
2793: if (ai->ai_next)
2794: continue;
2795:
1.35 markus 2796: for (n = 0; n < num_socks; n++) {
2797: close(socks[n]);
2798: }
2799: num_socks = 0;
2800: break;
2801: }
2802: socks[num_socks++] = sock;
2803: if (num_socks == NUM_SOCKS)
2804: break;
1.25 markus 2805: }
1.83 stevesk 2806: freeaddrinfo(aitop);
1.35 markus 2807: if (num_socks > 0)
2808: break;
1.25 markus 2809: }
2810: if (display_number >= MAX_DISPLAYS) {
2811: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2812: return -1;
1.25 markus 2813: }
2814: /* Start listening for connections on the socket. */
1.35 markus 2815: for (n = 0; n < num_socks; n++) {
2816: sock = socks[n];
1.199 markus 2817: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2818: error("listen: %.100s", strerror(errno));
2819: close(sock);
1.141 stevesk 2820: return -1;
1.35 markus 2821: }
1.25 markus 2822: }
1.35 markus 2823:
2824: /* Allocate a channel for each socket. */
1.242 djm 2825: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2826: for (n = 0; n < num_socks; n++) {
2827: sock = socks[n];
1.149 markus 2828: nc = channel_new("x11 listener",
1.51 markus 2829: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2830: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2831: 0, "X11 inet listener", 1);
1.167 markus 2832: nc->single_connection = single_connection;
1.224 markus 2833: (*chanids)[n] = nc->self;
1.35 markus 2834: }
1.224 markus 2835: (*chanids)[n] = -1;
1.1 deraadt 2836:
1.141 stevesk 2837: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2838: *display_numberp = display_number;
2839: return (0);
1.1 deraadt 2840: }
2841:
1.127 itojun 2842: static int
1.77 markus 2843: connect_local_xsocket(u_int dnr)
1.1 deraadt 2844: {
1.25 markus 2845: int sock;
2846: struct sockaddr_un addr;
2847:
1.147 stevesk 2848: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2849: if (sock < 0)
2850: error("socket: %.100s", strerror(errno));
2851: memset(&addr, 0, sizeof(addr));
2852: addr.sun_family = AF_UNIX;
2853: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2854: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2855: return sock;
2856: close(sock);
1.25 markus 2857: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2858: return -1;
1.1 deraadt 2859: }
2860:
1.51 markus 2861: int
2862: x11_connect_display(void)
1.1 deraadt 2863: {
1.248 deraadt 2864: u_int display_number;
1.25 markus 2865: const char *display;
1.51 markus 2866: char buf[1024], *cp;
1.35 markus 2867: struct addrinfo hints, *ai, *aitop;
2868: char strport[NI_MAXSERV];
1.248 deraadt 2869: int gaierr, sock = 0;
1.25 markus 2870:
2871: /* Try to open a socket for the local X server. */
2872: display = getenv("DISPLAY");
2873: if (!display) {
2874: error("DISPLAY not set.");
1.51 markus 2875: return -1;
1.25 markus 2876: }
1.27 markus 2877: /*
2878: * Now we decode the value of the DISPLAY variable and make a
2879: * connection to the real X server.
2880: */
2881:
2882: /*
2883: * Check if it is a unix domain socket. Unix domain displays are in
2884: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2885: */
1.25 markus 2886: if (strncmp(display, "unix:", 5) == 0 ||
2887: display[0] == ':') {
2888: /* Connect to the unix domain socket. */
1.248 deraadt 2889: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 2890: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2891: display);
1.51 markus 2892: return -1;
1.25 markus 2893: }
2894: /* Create a socket. */
2895: sock = connect_local_xsocket(display_number);
2896: if (sock < 0)
1.51 markus 2897: return -1;
1.25 markus 2898:
2899: /* OK, we now have a connection to the display. */
1.51 markus 2900: return sock;
1.25 markus 2901: }
1.27 markus 2902: /*
2903: * Connect to an inet socket. The DISPLAY value is supposedly
2904: * hostname:d[.s], where hostname may also be numeric IP address.
2905: */
1.145 stevesk 2906: strlcpy(buf, display, sizeof(buf));
1.25 markus 2907: cp = strchr(buf, ':');
2908: if (!cp) {
2909: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2910: return -1;
1.25 markus 2911: }
2912: *cp = 0;
1.27 markus 2913: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 2914: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 2915: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2916: display);
1.51 markus 2917: return -1;
1.25 markus 2918: }
1.35 markus 2919:
2920: /* Look up the host address */
2921: memset(&hints, 0, sizeof(hints));
2922: hints.ai_family = IPv4or6;
2923: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 2924: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 2925: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2926: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2927: return -1;
1.25 markus 2928: }
1.35 markus 2929: for (ai = aitop; ai; ai = ai->ai_next) {
2930: /* Create a socket. */
1.189 markus 2931: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2932: if (sock < 0) {
1.194 markus 2933: debug2("socket: %.100s", strerror(errno));
1.41 markus 2934: continue;
2935: }
2936: /* Connect it to the display. */
2937: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 2938: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 2939: 6000 + display_number, strerror(errno));
2940: close(sock);
2941: continue;
2942: }
2943: /* Success */
2944: break;
1.35 markus 2945: }
2946: freeaddrinfo(aitop);
2947: if (!ai) {
1.248 deraadt 2948: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 2949: strerror(errno));
1.51 markus 2950: return -1;
1.25 markus 2951: }
1.162 stevesk 2952: set_nodelay(sock);
1.51 markus 2953: return sock;
2954: }
2955:
2956: /*
2957: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2958: * the remote channel number. We should do whatever we want, and respond
2959: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2960: */
2961:
2962: void
1.154 markus 2963: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2964: {
1.113 markus 2965: Channel *c = NULL;
2966: int remote_id, sock = 0;
1.51 markus 2967: char *remote_host;
1.25 markus 2968:
1.113 markus 2969: debug("Received X11 open request.");
1.51 markus 2970:
1.113 markus 2971: remote_id = packet_get_int();
1.121 markus 2972:
2973: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2974: remote_host = packet_get_string(NULL);
1.51 markus 2975: } else {
2976: remote_host = xstrdup("unknown (remote did not supply name)");
2977: }
1.152 markus 2978: packet_check_eom();
1.25 markus 2979:
1.51 markus 2980: /* Obtain a connection to the real X display. */
2981: sock = x11_connect_display();
1.113 markus 2982: if (sock != -1) {
2983: /* Allocate a channel for this connection. */
2984: c = channel_new("connected x11 socket",
2985: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2986: remote_host, 1);
1.167 markus 2987: c->remote_id = remote_id;
2988: c->force_drain = 1;
1.113 markus 2989: }
1.190 markus 2990: xfree(remote_host);
1.113 markus 2991: if (c == NULL) {
1.51 markus 2992: /* Send refusal to the remote host. */
2993: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2994: packet_put_int(remote_id);
1.51 markus 2995: } else {
2996: /* Send a confirmation to the remote host. */
2997: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2998: packet_put_int(remote_id);
2999: packet_put_int(c->self);
1.51 markus 3000: }
1.113 markus 3001: packet_send();
1.72 markus 3002: }
3003:
3004: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3005: void
1.154 markus 3006: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3007: {
3008: int rchan = packet_get_int();
1.180 deraadt 3009:
1.143 deraadt 3010: switch (type) {
1.72 markus 3011: case SSH_SMSG_AGENT_OPEN:
3012: error("Warning: ssh server tried agent forwarding.");
3013: break;
3014: case SSH_SMSG_X11_OPEN:
3015: error("Warning: ssh server tried X11 forwarding.");
3016: break;
3017: default:
1.154 markus 3018: error("deny_input_open: type %d", type);
1.72 markus 3019: break;
3020: }
1.230 stevesk 3021: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3022: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3023: packet_put_int(rchan);
3024: packet_send();
1.1 deraadt 3025: }
3026:
1.27 markus 3027: /*
3028: * Requests forwarding of X11 connections, generates fake authentication
3029: * data, and enables authentication spoofing.
1.121 markus 3030: * This should be called in the client only.
1.27 markus 3031: */
1.49 markus 3032: void
1.215 djm 3033: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3034: const char *proto, const char *data)
1.1 deraadt 3035: {
1.77 markus 3036: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3037: u_int i, value;
1.25 markus 3038: char *new_data;
3039: int screen_number;
3040: const char *cp;
1.207 avsm 3041: u_int32_t rnd = 0;
1.25 markus 3042:
1.220 markus 3043: if (x11_saved_display == NULL)
3044: x11_saved_display = xstrdup(disp);
3045: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3046: error("x11_request_forwarding_with_spoofing: different "
3047: "$DISPLAY already forwarded");
3048: return;
3049: }
3050:
1.215 djm 3051: cp = disp;
3052: if (disp)
3053: cp = strchr(disp, ':');
1.25 markus 3054: if (cp)
3055: cp = strchr(cp, '.');
3056: if (cp)
1.245 deraadt 3057: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3058: else
3059: screen_number = 0;
3060:
1.219 djm 3061: if (x11_saved_proto == NULL) {
3062: /* Save protocol name. */
3063: x11_saved_proto = xstrdup(proto);
3064: /*
1.221 djm 3065: * Extract real authentication data and generate fake data
1.219 djm 3066: * of the same length.
3067: */
3068: x11_saved_data = xmalloc(data_len);
3069: x11_fake_data = xmalloc(data_len);
3070: for (i = 0; i < data_len; i++) {
3071: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3072: fatal("x11_request_forwarding: bad "
3073: "authentication data: %.100s", data);
3074: if (i % 4 == 0)
3075: rnd = arc4random();
3076: x11_saved_data[i] = value;
3077: x11_fake_data[i] = rnd & 0xff;
3078: rnd >>= 8;
3079: }
3080: x11_saved_data_len = data_len;
3081: x11_fake_data_len = data_len;
1.25 markus 3082: }
3083:
3084: /* Convert the fake data into hex. */
1.219 djm 3085: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3086:
3087: /* Send the request packet. */
1.51 markus 3088: if (compat20) {
3089: channel_request_start(client_session_id, "x11-req", 0);
3090: packet_put_char(0); /* XXX bool single connection */
3091: } else {
3092: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3093: }
3094: packet_put_cstring(proto);
3095: packet_put_cstring(new_data);
1.25 markus 3096: packet_put_int(screen_number);
3097: packet_send();
3098: packet_write_wait();
3099: xfree(new_data);
1.1 deraadt 3100: }
3101:
1.121 markus 3102:
3103: /* -- agent forwarding */
3104:
1.1 deraadt 3105: /* Sends a message to the server to request authentication fd forwarding. */
3106:
1.49 markus 3107: void
1.142 itojun 3108: auth_request_forwarding(void)
1.1 deraadt 3109: {
1.25 markus 3110: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3111: packet_send();
3112: packet_write_wait();
1.1 deraadt 3113: }