Annotation of src/usr.bin/ssh/channels.c, Revision 1.235
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.156 markus 16: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.235 ! stevesk 42: RCSID("$OpenBSD: channels.c,v 1.234 2006/02/10 00:27:13 stevesk Exp $");
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: */
132: static char *x11_fake_data = NULL;
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:
177: switch(c->type) {
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: break;
188: }
189: logit("Non-public channel %d, type %d.", id, c->type);
190: return (NULL);
191: }
192:
193: /*
1.55 markus 194: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 195: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 196: */
1.1 deraadt 197:
1.127 itojun 198: static void
1.71 markus 199: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
200: int extusage, int nonblock)
1.1 deraadt 201: {
1.25 markus 202: /* Update the maximum file descriptor value. */
1.84 markus 203: channel_max_fd = MAX(channel_max_fd, rfd);
204: channel_max_fd = MAX(channel_max_fd, wfd);
205: channel_max_fd = MAX(channel_max_fd, efd);
206:
1.27 markus 207: /* XXX set close-on-exec -markus */
1.55 markus 208:
1.52 markus 209: c->rfd = rfd;
210: c->wfd = wfd;
211: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 212: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 213: c->efd = efd;
214: c->extended_usage = extusage;
1.71 markus 215:
1.91 markus 216: /* XXX ugly hack: nonblock is only set by the server */
217: if (nonblock && isatty(c->rfd)) {
1.194 markus 218: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 219: c->isatty = 1;
220: if (!isatty(c->wfd)) {
1.94 markus 221: error("channel %d: wfd %d is not a tty?",
1.91 markus 222: c->self, c->wfd);
223: }
224: } else {
225: c->isatty = 0;
226: }
227:
1.71 markus 228: /* enable nonblocking mode */
229: if (nonblock) {
230: if (rfd != -1)
231: set_nonblock(rfd);
232: if (wfd != -1)
233: set_nonblock(wfd);
234: if (efd != -1)
235: set_nonblock(efd);
236: }
1.52 markus 237: }
238:
239: /*
240: * Allocate a new channel object and set its type and socket. This will cause
241: * remote_name to be freed.
242: */
243:
1.113 markus 244: Channel *
1.52 markus 245: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 246: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 247: {
1.209 avsm 248: int found;
249: u_int i;
1.52 markus 250: Channel *c;
1.25 markus 251:
252: /* Do initial allocation if this is the first call. */
253: if (channels_alloc == 0) {
254: channels_alloc = 10;
1.113 markus 255: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 256: for (i = 0; i < channels_alloc; i++)
1.113 markus 257: channels[i] = NULL;
1.25 markus 258: }
259: /* Try to find a free slot where to put the new channel. */
260: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 261: if (channels[i] == NULL) {
1.25 markus 262: /* Found a free slot. */
1.209 avsm 263: found = (int)i;
1.25 markus 264: break;
265: }
1.209 avsm 266: if (found < 0) {
1.27 markus 267: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 268: found = channels_alloc;
1.179 markus 269: if (channels_alloc > 10000)
270: fatal("channel_new: internal error: channels_alloc %d "
271: "too big.", channels_alloc);
1.195 markus 272: channels = xrealloc(channels,
273: (channels_alloc + 10) * sizeof(Channel *));
274: channels_alloc += 10;
1.70 markus 275: debug2("channel: expanding %d", channels_alloc);
1.25 markus 276: for (i = found; i < channels_alloc; i++)
1.113 markus 277: channels[i] = NULL;
1.25 markus 278: }
1.113 markus 279: /* Initialize and return new channel. */
280: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 281: memset(c, 0, sizeof(Channel));
1.25 markus 282: buffer_init(&c->input);
283: buffer_init(&c->output);
1.41 markus 284: buffer_init(&c->extended);
1.159 markus 285: c->ostate = CHAN_OUTPUT_OPEN;
286: c->istate = CHAN_INPUT_OPEN;
287: c->flags = 0;
1.71 markus 288: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 289: c->self = found;
290: c->type = type;
1.41 markus 291: c->ctype = ctype;
1.51 markus 292: c->local_window = window;
293: c->local_window_max = window;
294: c->local_consumed = 0;
295: c->local_maxpacket = maxpack;
1.25 markus 296: c->remote_id = -1;
1.190 markus 297: c->remote_name = xstrdup(remote_name);
1.41 markus 298: c->remote_window = 0;
299: c->remote_maxpacket = 0;
1.133 markus 300: c->force_drain = 0;
1.149 markus 301: c->single_connection = 0;
1.131 markus 302: c->detach_user = NULL;
1.225 djm 303: c->detach_close = 0;
1.165 markus 304: c->confirm = NULL;
1.204 djm 305: c->confirm_ctx = NULL;
1.65 markus 306: c->input_filter = NULL;
1.231 reyk 307: c->output_filter = NULL;
1.25 markus 308: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 309: return c;
1.1 deraadt 310: }
1.52 markus 311:
1.132 markus 312: static int
313: channel_find_maxfd(void)
314: {
1.209 avsm 315: u_int i;
316: int max = 0;
1.132 markus 317: Channel *c;
318:
319: for (i = 0; i < channels_alloc; i++) {
320: c = channels[i];
321: if (c != NULL) {
322: max = MAX(max, c->rfd);
323: max = MAX(max, c->wfd);
324: max = MAX(max, c->efd);
325: }
326: }
327: return max;
328: }
329:
330: int
331: channel_close_fd(int *fdp)
332: {
333: int ret = 0, fd = *fdp;
334:
335: if (fd != -1) {
336: ret = close(fd);
337: *fdp = -1;
338: if (fd == channel_max_fd)
339: channel_max_fd = channel_find_maxfd();
340: }
341: return ret;
342: }
343:
1.52 markus 344: /* Close all channel fd/socket. */
345:
1.127 itojun 346: static void
1.52 markus 347: channel_close_fds(Channel *c)
348: {
1.204 djm 349: debug3("channel %d: close_fds r %d w %d e %d c %d",
350: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 351:
1.132 markus 352: channel_close_fd(&c->sock);
1.204 djm 353: channel_close_fd(&c->ctl_fd);
1.132 markus 354: channel_close_fd(&c->rfd);
355: channel_close_fd(&c->wfd);
356: channel_close_fd(&c->efd);
1.121 markus 357: }
358:
359: /* Free the channel and close its fd/socket. */
360:
361: void
362: channel_free(Channel *c)
363: {
364: char *s;
1.209 avsm 365: u_int i, n;
1.121 markus 366:
367: for (n = 0, i = 0; i < channels_alloc; i++)
368: if (channels[i])
369: n++;
1.209 avsm 370: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 371: c->remote_name ? c->remote_name : "???", n);
372:
373: s = channel_open_message();
1.194 markus 374: debug3("channel %d: status: %s", c->self, s);
1.121 markus 375: xfree(s);
376:
377: if (c->sock != -1)
378: shutdown(c->sock, SHUT_RDWR);
1.204 djm 379: if (c->ctl_fd != -1)
380: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 381: channel_close_fds(c);
382: buffer_free(&c->input);
383: buffer_free(&c->output);
384: buffer_free(&c->extended);
385: if (c->remote_name) {
386: xfree(c->remote_name);
387: c->remote_name = NULL;
388: }
389: channels[c->self] = NULL;
390: xfree(c);
391: }
392:
393: void
1.126 markus 394: channel_free_all(void)
1.121 markus 395: {
1.209 avsm 396: u_int i;
1.121 markus 397:
1.126 markus 398: for (i = 0; i < channels_alloc; i++)
399: if (channels[i] != NULL)
400: channel_free(channels[i]);
1.131 markus 401: }
402:
1.121 markus 403: /*
404: * Closes the sockets/fds of all channels. This is used to close extra file
405: * descriptors after a fork.
406: */
407:
408: void
1.142 itojun 409: channel_close_all(void)
1.121 markus 410: {
1.209 avsm 411: u_int i;
1.121 markus 412:
413: for (i = 0; i < channels_alloc; i++)
414: if (channels[i] != NULL)
415: channel_close_fds(channels[i]);
416: }
417:
418: /*
1.131 markus 419: * Stop listening to channels.
420: */
421:
422: void
423: channel_stop_listening(void)
424: {
1.209 avsm 425: u_int i;
1.131 markus 426: Channel *c;
427:
428: for (i = 0; i < channels_alloc; i++) {
429: c = channels[i];
430: if (c != NULL) {
431: switch (c->type) {
432: case SSH_CHANNEL_AUTH_SOCKET:
433: case SSH_CHANNEL_PORT_LISTENER:
434: case SSH_CHANNEL_RPORT_LISTENER:
435: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 436: channel_close_fd(&c->sock);
1.131 markus 437: channel_free(c);
438: break;
439: }
440: }
441: }
442: }
443:
444: /*
1.121 markus 445: * Returns true if no channel has too much buffered data, and false if one or
446: * more channel is overfull.
447: */
448:
449: int
1.142 itojun 450: channel_not_very_much_buffered_data(void)
1.121 markus 451: {
452: u_int i;
453: Channel *c;
454:
455: for (i = 0; i < channels_alloc; i++) {
456: c = channels[i];
457: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 458: #if 0
459: if (!compat20 &&
460: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 461: debug2("channel %d: big input buffer %d",
1.121 markus 462: c->self, buffer_len(&c->input));
463: return 0;
464: }
1.136 markus 465: #endif
1.121 markus 466: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 467: debug2("channel %d: big output buffer %u > %u",
1.136 markus 468: c->self, buffer_len(&c->output),
469: packet_get_maxsize());
1.121 markus 470: return 0;
471: }
472: }
473: }
474: return 1;
475: }
476:
477: /* Returns true if any channel is still open. */
478:
479: int
1.142 itojun 480: channel_still_open(void)
1.121 markus 481: {
1.209 avsm 482: u_int i;
1.121 markus 483: Channel *c;
484:
485: for (i = 0; i < channels_alloc; i++) {
486: c = channels[i];
487: if (c == NULL)
488: continue;
489: switch (c->type) {
490: case SSH_CHANNEL_X11_LISTENER:
491: case SSH_CHANNEL_PORT_LISTENER:
492: case SSH_CHANNEL_RPORT_LISTENER:
493: case SSH_CHANNEL_CLOSED:
494: case SSH_CHANNEL_AUTH_SOCKET:
495: case SSH_CHANNEL_DYNAMIC:
496: case SSH_CHANNEL_CONNECTING:
497: case SSH_CHANNEL_ZOMBIE:
498: continue;
499: case SSH_CHANNEL_LARVAL:
500: if (!compat20)
501: fatal("cannot happen: SSH_CHANNEL_LARVAL");
502: continue;
503: case SSH_CHANNEL_OPENING:
504: case SSH_CHANNEL_OPEN:
505: case SSH_CHANNEL_X11_OPEN:
506: return 1;
507: case SSH_CHANNEL_INPUT_DRAINING:
508: case SSH_CHANNEL_OUTPUT_DRAINING:
509: if (!compat13)
510: fatal("cannot happen: OUT_DRAIN");
511: return 1;
512: default:
513: fatal("channel_still_open: bad channel type %d", c->type);
514: /* NOTREACHED */
515: }
516: }
517: return 0;
518: }
519:
520: /* Returns the id of an open channel suitable for keepaliving */
521:
522: int
1.142 itojun 523: channel_find_open(void)
1.121 markus 524: {
1.209 avsm 525: u_int i;
1.121 markus 526: Channel *c;
527:
528: for (i = 0; i < channels_alloc; i++) {
529: c = channels[i];
1.206 djm 530: if (c == NULL || c->remote_id < 0)
1.121 markus 531: continue;
532: switch (c->type) {
533: case SSH_CHANNEL_CLOSED:
534: case SSH_CHANNEL_DYNAMIC:
535: case SSH_CHANNEL_X11_LISTENER:
536: case SSH_CHANNEL_PORT_LISTENER:
537: case SSH_CHANNEL_RPORT_LISTENER:
538: case SSH_CHANNEL_OPENING:
539: case SSH_CHANNEL_CONNECTING:
540: case SSH_CHANNEL_ZOMBIE:
541: continue;
542: case SSH_CHANNEL_LARVAL:
543: case SSH_CHANNEL_AUTH_SOCKET:
544: case SSH_CHANNEL_OPEN:
545: case SSH_CHANNEL_X11_OPEN:
546: return i;
547: case SSH_CHANNEL_INPUT_DRAINING:
548: case SSH_CHANNEL_OUTPUT_DRAINING:
549: if (!compat13)
550: fatal("cannot happen: OUT_DRAIN");
551: return i;
552: default:
553: fatal("channel_find_open: bad channel type %d", c->type);
554: /* NOTREACHED */
555: }
556: }
557: return -1;
558: }
559:
560:
561: /*
562: * Returns a message describing the currently open forwarded connections,
563: * suitable for sending to the client. The message contains crlf pairs for
564: * newlines.
565: */
566:
567: char *
1.142 itojun 568: channel_open_message(void)
1.121 markus 569: {
570: Buffer buffer;
571: Channel *c;
572: char buf[1024], *cp;
1.209 avsm 573: u_int i;
1.121 markus 574:
575: buffer_init(&buffer);
576: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
577: buffer_append(&buffer, buf, strlen(buf));
578: for (i = 0; i < channels_alloc; i++) {
579: c = channels[i];
580: if (c == NULL)
581: continue;
582: switch (c->type) {
583: case SSH_CHANNEL_X11_LISTENER:
584: case SSH_CHANNEL_PORT_LISTENER:
585: case SSH_CHANNEL_RPORT_LISTENER:
586: case SSH_CHANNEL_CLOSED:
587: case SSH_CHANNEL_AUTH_SOCKET:
588: case SSH_CHANNEL_ZOMBIE:
589: continue;
590: case SSH_CHANNEL_LARVAL:
591: case SSH_CHANNEL_OPENING:
592: case SSH_CHANNEL_CONNECTING:
593: case SSH_CHANNEL_DYNAMIC:
594: case SSH_CHANNEL_OPEN:
595: case SSH_CHANNEL_X11_OPEN:
596: case SSH_CHANNEL_INPUT_DRAINING:
597: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 598: snprintf(buf, sizeof buf,
599: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 600: c->self, c->remote_name,
601: c->type, c->remote_id,
602: c->istate, buffer_len(&c->input),
603: c->ostate, buffer_len(&c->output),
1.204 djm 604: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 605: buffer_append(&buffer, buf, strlen(buf));
606: continue;
607: default:
608: fatal("channel_open_message: bad channel type %d", c->type);
609: /* NOTREACHED */
610: }
611: }
612: buffer_append(&buffer, "\0", 1);
613: cp = xstrdup(buffer_ptr(&buffer));
614: buffer_free(&buffer);
615: return cp;
616: }
617:
618: void
619: channel_send_open(int id)
620: {
621: Channel *c = channel_lookup(id);
1.180 deraadt 622:
1.121 markus 623: if (c == NULL) {
1.188 itojun 624: logit("channel_send_open: %d: bad id", id);
1.121 markus 625: return;
626: }
1.184 markus 627: debug2("channel %d: send open", id);
1.121 markus 628: packet_start(SSH2_MSG_CHANNEL_OPEN);
629: packet_put_cstring(c->ctype);
630: packet_put_int(c->self);
631: packet_put_int(c->local_window);
632: packet_put_int(c->local_maxpacket);
633: packet_send();
634: }
635:
636: void
1.184 markus 637: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 638: {
1.184 markus 639: Channel *c = channel_lookup(id);
1.180 deraadt 640:
1.121 markus 641: if (c == NULL) {
1.188 itojun 642: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 643: return;
644: }
1.204 djm 645: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 646: packet_start(SSH2_MSG_CHANNEL_REQUEST);
647: packet_put_int(c->remote_id);
648: packet_put_cstring(service);
649: packet_put_char(wantconfirm);
650: }
651: void
1.204 djm 652: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 653: {
654: Channel *c = channel_lookup(id);
1.180 deraadt 655:
1.121 markus 656: if (c == NULL) {
1.188 itojun 657: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 658: return;
659: }
1.165 markus 660: c->confirm = fn;
1.204 djm 661: c->confirm_ctx = ctx;
1.121 markus 662: }
663: void
1.225 djm 664: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 665: {
1.229 markus 666: Channel *c = channel_by_id(id);
1.180 deraadt 667:
1.121 markus 668: if (c == NULL) {
1.188 itojun 669: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 670: return;
671: }
1.131 markus 672: c->detach_user = fn;
1.225 djm 673: c->detach_close = do_close;
1.121 markus 674: }
675: void
676: channel_cancel_cleanup(int id)
677: {
1.229 markus 678: Channel *c = channel_by_id(id);
1.180 deraadt 679:
1.121 markus 680: if (c == NULL) {
1.188 itojun 681: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 682: return;
1.52 markus 683: }
1.131 markus 684: c->detach_user = NULL;
1.225 djm 685: c->detach_close = 0;
1.121 markus 686: }
687: void
1.231 reyk 688: channel_register_filter(int id, channel_infilter_fn *ifn,
689: channel_outfilter_fn *ofn)
1.121 markus 690: {
691: Channel *c = channel_lookup(id);
1.180 deraadt 692:
1.121 markus 693: if (c == NULL) {
1.188 itojun 694: logit("channel_register_filter: %d: bad id", id);
1.121 markus 695: return;
1.52 markus 696: }
1.231 reyk 697: c->input_filter = ifn;
698: c->output_filter = ofn;
1.52 markus 699: }
700:
1.49 markus 701: void
1.121 markus 702: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 703: int extusage, int nonblock, u_int window_max)
1.1 deraadt 704: {
1.121 markus 705: Channel *c = channel_lookup(id);
1.180 deraadt 706:
1.121 markus 707: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
708: fatal("channel_activate for non-larval channel %d.", id);
709: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
710: c->type = SSH_CHANNEL_OPEN;
1.168 markus 711: c->local_window = c->local_window_max = window_max;
1.121 markus 712: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
713: packet_put_int(c->remote_id);
714: packet_put_int(c->local_window);
715: packet_send();
1.1 deraadt 716: }
717:
1.27 markus 718: /*
1.41 markus 719: * 'channel_pre*' are called just before select() to add any bits relevant to
720: * channels in the select bitmasks.
721: */
722: /*
723: * 'channel_post*': perform any appropriate operations for channels which
724: * have events pending.
1.27 markus 725: */
1.41 markus 726: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
727: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
728: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
729:
1.127 itojun 730: static void
1.41 markus 731: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
732: {
733: FD_SET(c->sock, readset);
734: }
735:
1.127 itojun 736: static void
1.75 markus 737: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
738: {
739: debug3("channel %d: waiting for connection", c->self);
740: FD_SET(c->sock, writeset);
741: }
742:
1.127 itojun 743: static void
1.41 markus 744: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
745: {
746: if (buffer_len(&c->input) < packet_get_maxsize())
747: FD_SET(c->sock, readset);
748: if (buffer_len(&c->output) > 0)
749: FD_SET(c->sock, writeset);
750: }
1.1 deraadt 751:
1.127 itojun 752: static void
1.157 markus 753: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 754: {
1.157 markus 755: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 756:
1.214 markus 757: /* check buffer limits */
758: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
759:
1.44 markus 760: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 761: limit > 0 &&
762: buffer_len(&c->input) < limit)
1.44 markus 763: FD_SET(c->rfd, readset);
764: if (c->ostate == CHAN_OUTPUT_OPEN ||
765: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
766: if (buffer_len(&c->output) > 0) {
767: FD_SET(c->wfd, writeset);
768: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 769: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 770: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
771: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 772: else
773: chan_obuf_empty(c);
1.44 markus 774: }
775: }
776: /** XXX check close conditions, too */
1.157 markus 777: if (compat20 && c->efd != -1) {
1.44 markus 778: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
779: buffer_len(&c->extended) > 0)
780: FD_SET(c->efd, writeset);
1.172 markus 781: else if (!(c->flags & CHAN_EOF_SENT) &&
782: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 783: buffer_len(&c->extended) < c->remote_window)
784: FD_SET(c->efd, readset);
785: }
1.204 djm 786: /* XXX: What about efd? races? */
1.208 deraadt 787: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 788: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
789: FD_SET(c->ctl_fd, readset);
1.44 markus 790: }
791:
1.127 itojun 792: static void
1.41 markus 793: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
794: {
795: if (buffer_len(&c->input) == 0) {
796: packet_start(SSH_MSG_CHANNEL_CLOSE);
797: packet_put_int(c->remote_id);
798: packet_send();
799: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 800: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 801: }
802: }
803:
1.127 itojun 804: static void
1.41 markus 805: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
806: {
807: if (buffer_len(&c->output) == 0)
1.113 markus 808: chan_mark_dead(c);
1.49 markus 809: else
1.41 markus 810: FD_SET(c->sock, writeset);
811: }
812:
813: /*
814: * This is a special state for X11 authentication spoofing. An opened X11
815: * connection (when authentication spoofing is being done) remains in this
816: * state until the first packet has been completely read. The authentication
817: * data in that packet is then substituted by the real data if it matches the
818: * fake data, and the channel is put into normal mode.
1.51 markus 819: * XXX All this happens at the client side.
1.121 markus 820: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 821: */
1.127 itojun 822: static int
1.121 markus 823: x11_open_helper(Buffer *b)
1.1 deraadt 824: {
1.77 markus 825: u_char *ucp;
826: u_int proto_len, data_len;
1.25 markus 827:
1.41 markus 828: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 829: if (buffer_len(b) < 12)
1.41 markus 830: return 0;
831:
832: /* Parse the lengths of variable-length fields. */
1.155 stevesk 833: ucp = buffer_ptr(b);
1.41 markus 834: if (ucp[0] == 0x42) { /* Byte order MSB first. */
835: proto_len = 256 * ucp[6] + ucp[7];
836: data_len = 256 * ucp[8] + ucp[9];
837: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
838: proto_len = ucp[6] + 256 * ucp[7];
839: data_len = ucp[8] + 256 * ucp[9];
840: } else {
1.194 markus 841: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 842: ucp[0]);
1.41 markus 843: return -1;
844: }
845:
846: /* Check if the whole packet is in buffer. */
1.121 markus 847: if (buffer_len(b) <
1.41 markus 848: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
849: return 0;
850:
851: /* Check if authentication protocol matches. */
852: if (proto_len != strlen(x11_saved_proto) ||
853: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 854: debug2("X11 connection uses different authentication protocol.");
1.41 markus 855: return -1;
856: }
857: /* Check if authentication data matches our fake data. */
858: if (data_len != x11_fake_data_len ||
859: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
860: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 861: debug2("X11 auth data does not match fake data.");
1.41 markus 862: return -1;
863: }
864: /* Check fake data length */
865: if (x11_fake_data_len != x11_saved_data_len) {
866: error("X11 fake_data_len %d != saved_data_len %d",
867: x11_fake_data_len, x11_saved_data_len);
868: return -1;
869: }
870: /*
871: * Received authentication protocol and data match
872: * our fake data. Substitute the fake data with real
873: * data.
874: */
875: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
876: x11_saved_data, x11_saved_data_len);
877: return 1;
878: }
879:
1.127 itojun 880: static void
1.41 markus 881: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
882: {
1.121 markus 883: int ret = x11_open_helper(&c->output);
1.180 deraadt 884:
1.41 markus 885: if (ret == 1) {
886: /* Start normal processing for the channel. */
887: c->type = SSH_CHANNEL_OPEN;
1.47 markus 888: channel_pre_open_13(c, readset, writeset);
1.41 markus 889: } else if (ret == -1) {
890: /*
891: * We have received an X11 connection that has bad
892: * authentication information.
893: */
1.188 itojun 894: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 895: buffer_clear(&c->input);
896: buffer_clear(&c->output);
1.132 markus 897: channel_close_fd(&c->sock);
1.41 markus 898: c->sock = -1;
899: c->type = SSH_CHANNEL_CLOSED;
900: packet_start(SSH_MSG_CHANNEL_CLOSE);
901: packet_put_int(c->remote_id);
902: packet_send();
903: }
904: }
1.25 markus 905:
1.127 itojun 906: static void
1.51 markus 907: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 908: {
1.121 markus 909: int ret = x11_open_helper(&c->output);
1.133 markus 910:
911: /* c->force_drain = 1; */
912:
1.41 markus 913: if (ret == 1) {
914: c->type = SSH_CHANNEL_OPEN;
1.157 markus 915: channel_pre_open(c, readset, writeset);
1.41 markus 916: } else if (ret == -1) {
1.188 itojun 917: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 918: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 919: chan_read_failed(c);
920: buffer_clear(&c->input);
921: chan_ibuf_empty(c);
922: buffer_clear(&c->output);
923: /* for proto v1, the peer will send an IEOF */
924: if (compat20)
925: chan_write_failed(c);
926: else
927: c->type = SSH_CHANNEL_OPEN;
1.194 markus 928: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 929: }
930: }
1.25 markus 931:
1.104 markus 932: /* try to decode a socks4 header */
1.127 itojun 933: static int
1.104 markus 934: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 935: {
1.181 markus 936: char *p, *host;
1.217 djm 937: u_int len, have, i, found;
1.148 deraadt 938: char username[256];
1.103 markus 939: struct {
940: u_int8_t version;
941: u_int8_t command;
942: u_int16_t dest_port;
1.104 markus 943: struct in_addr dest_addr;
1.103 markus 944: } s4_req, s4_rsp;
945:
1.104 markus 946: debug2("channel %d: decode socks4", c->self);
1.109 markus 947:
948: have = buffer_len(&c->input);
949: len = sizeof(s4_req);
950: if (have < len)
951: return 0;
952: p = buffer_ptr(&c->input);
953: for (found = 0, i = len; i < have; i++) {
954: if (p[i] == '\0') {
955: found = 1;
956: break;
957: }
958: if (i > 1024) {
959: /* the peer is probably sending garbage */
960: debug("channel %d: decode socks4: too long",
961: c->self);
962: return -1;
963: }
964: }
965: if (!found)
966: return 0;
1.103 markus 967: buffer_get(&c->input, (char *)&s4_req.version, 1);
968: buffer_get(&c->input, (char *)&s4_req.command, 1);
969: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 970: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 971: have = buffer_len(&c->input);
1.103 markus 972: p = buffer_ptr(&c->input);
973: len = strlen(p);
1.106 markus 974: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 975: if (len > have)
1.104 markus 976: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 977: c->self, len, have);
978: strlcpy(username, p, sizeof(username));
979: buffer_consume(&c->input, len);
980: buffer_consume(&c->input, 1); /* trailing '\0' */
981:
1.104 markus 982: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 983: strlcpy(c->path, host, sizeof(c->path));
984: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 985:
1.194 markus 986: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 987: c->self, host, c->host_port, s4_req.command);
1.103 markus 988:
1.104 markus 989: if (s4_req.command != 1) {
990: debug("channel %d: cannot handle: socks4 cn %d",
991: c->self, s4_req.command);
992: return -1;
1.103 markus 993: }
1.104 markus 994: s4_rsp.version = 0; /* vn: 0 for reply */
995: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 996: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 997: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 998: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 999: return 1;
1000: }
1001:
1.193 markus 1002: /* try to decode a socks5 header */
1003: #define SSH_SOCKS5_AUTHDONE 0x1000
1004: #define SSH_SOCKS5_NOAUTH 0x00
1005: #define SSH_SOCKS5_IPV4 0x01
1006: #define SSH_SOCKS5_DOMAIN 0x03
1007: #define SSH_SOCKS5_IPV6 0x04
1008: #define SSH_SOCKS5_CONNECT 0x01
1009: #define SSH_SOCKS5_SUCCESS 0x00
1010:
1011: static int
1012: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
1013: {
1014: struct {
1015: u_int8_t version;
1016: u_int8_t command;
1017: u_int8_t reserved;
1018: u_int8_t atyp;
1019: } s5_req, s5_rsp;
1020: u_int16_t dest_port;
1021: u_char *p, dest_addr[255+1];
1.217 djm 1022: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 1023:
1024: debug2("channel %d: decode socks5", c->self);
1025: p = buffer_ptr(&c->input);
1026: if (p[0] != 0x05)
1027: return -1;
1028: have = buffer_len(&c->input);
1029: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1030: /* format: ver | nmethods | methods */
1.198 djm 1031: if (have < 2)
1.193 markus 1032: return 0;
1033: nmethods = p[1];
1034: if (have < nmethods + 2)
1035: return 0;
1036: /* look for method: "NO AUTHENTICATION REQUIRED" */
1037: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1038: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1039: found = 1;
1040: break;
1041: }
1042: }
1043: if (!found) {
1044: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1045: c->self);
1046: return -1;
1047: }
1048: buffer_consume(&c->input, nmethods + 2);
1049: buffer_put_char(&c->output, 0x05); /* version */
1050: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1051: FD_SET(c->sock, writeset);
1052: c->flags |= SSH_SOCKS5_AUTHDONE;
1053: debug2("channel %d: socks5 auth done", c->self);
1054: return 0; /* need more */
1055: }
1056: debug2("channel %d: socks5 post auth", c->self);
1057: if (have < sizeof(s5_req)+1)
1058: return 0; /* need more */
1059: memcpy((char *)&s5_req, p, sizeof(s5_req));
1060: if (s5_req.version != 0x05 ||
1061: s5_req.command != SSH_SOCKS5_CONNECT ||
1062: s5_req.reserved != 0x00) {
1.194 markus 1063: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1064: return -1;
1065: }
1.213 deraadt 1066: switch (s5_req.atyp){
1.193 markus 1067: case SSH_SOCKS5_IPV4:
1068: addrlen = 4;
1069: af = AF_INET;
1070: break;
1071: case SSH_SOCKS5_DOMAIN:
1072: addrlen = p[sizeof(s5_req)];
1073: af = -1;
1074: break;
1075: case SSH_SOCKS5_IPV6:
1076: addrlen = 16;
1077: af = AF_INET6;
1078: break;
1079: default:
1.194 markus 1080: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1081: return -1;
1082: }
1083: if (have < 4 + addrlen + 2)
1084: return 0;
1085: buffer_consume(&c->input, sizeof(s5_req));
1086: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1087: buffer_consume(&c->input, 1); /* host string length */
1088: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1089: buffer_get(&c->input, (char *)&dest_port, 2);
1090: dest_addr[addrlen] = '\0';
1091: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1092: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1093: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1094: return -1;
1095: c->host_port = ntohs(dest_port);
1.198 djm 1096:
1.194 markus 1097: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1098: c->self, c->path, c->host_port, s5_req.command);
1099:
1100: s5_rsp.version = 0x05;
1101: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1102: s5_rsp.reserved = 0; /* ignored */
1103: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1104: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1105: dest_port = 0; /* ignored */
1106:
1107: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1108: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1109: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1110: return 1;
1111: }
1112:
1.104 markus 1113: /* dynamic port forwarding */
1.127 itojun 1114: static void
1.104 markus 1115: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1116: {
1117: u_char *p;
1.217 djm 1118: u_int have;
1119: int ret;
1.103 markus 1120:
1.104 markus 1121: have = buffer_len(&c->input);
1.137 markus 1122: c->delayed = 0;
1.104 markus 1123: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1124: /* buffer_dump(&c->input); */
1.104 markus 1125: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1126: if (have < 3) {
1.104 markus 1127: /* need more */
1128: FD_SET(c->sock, readset);
1129: return;
1130: }
1131: /* try to guess the protocol */
1132: p = buffer_ptr(&c->input);
1133: switch (p[0]) {
1134: case 0x04:
1135: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1136: break;
1137: case 0x05:
1138: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1139: break;
1140: default:
1141: ret = -1;
1142: break;
1143: }
1144: if (ret < 0) {
1.113 markus 1145: chan_mark_dead(c);
1.104 markus 1146: } else if (ret == 0) {
1147: debug2("channel %d: pre_dynamic: need more", c->self);
1148: /* need more */
1149: FD_SET(c->sock, readset);
1150: } else {
1151: /* switch to the next state */
1152: c->type = SSH_CHANNEL_OPENING;
1153: port_open_helper(c, "direct-tcpip");
1154: }
1.103 markus 1155: }
1156:
1.41 markus 1157: /* This is our fake X11 server socket. */
1.127 itojun 1158: static void
1.41 markus 1159: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1160: {
1.113 markus 1161: Channel *nc;
1.41 markus 1162: struct sockaddr addr;
1.162 stevesk 1163: int newsock;
1.41 markus 1164: socklen_t addrlen;
1.85 markus 1165: char buf[16384], *remote_ipaddr;
1.51 markus 1166: int remote_port;
1.25 markus 1167:
1.41 markus 1168: if (FD_ISSET(c->sock, readset)) {
1169: debug("X11 connection requested.");
1170: addrlen = sizeof(addr);
1171: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1172: if (c->single_connection) {
1.194 markus 1173: debug2("single_connection: closing X11 listener.");
1.149 markus 1174: channel_close_fd(&c->sock);
1175: chan_mark_dead(c);
1176: }
1.41 markus 1177: if (newsock < 0) {
1178: error("accept: %.100s", strerror(errno));
1179: return;
1180: }
1.162 stevesk 1181: set_nodelay(newsock);
1.85 markus 1182: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1183: remote_port = get_peer_port(newsock);
1.41 markus 1184: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1185: remote_ipaddr, remote_port);
1.51 markus 1186:
1.113 markus 1187: nc = channel_new("accepted x11 socket",
1.51 markus 1188: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1189: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1190: if (compat20) {
1191: packet_start(SSH2_MSG_CHANNEL_OPEN);
1192: packet_put_cstring("x11");
1.113 markus 1193: packet_put_int(nc->self);
1.149 markus 1194: packet_put_int(nc->local_window_max);
1195: packet_put_int(nc->local_maxpacket);
1.85 markus 1196: /* originator ipaddr and port */
1197: packet_put_cstring(remote_ipaddr);
1.57 markus 1198: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1199: debug2("ssh2 x11 bug compat mode");
1.57 markus 1200: } else {
1201: packet_put_int(remote_port);
1202: }
1.51 markus 1203: packet_send();
1204: } else {
1205: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1206: packet_put_int(nc->self);
1.121 markus 1207: if (packet_get_protocol_flags() &
1208: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1209: packet_put_cstring(buf);
1.51 markus 1210: packet_send();
1211: }
1.85 markus 1212: xfree(remote_ipaddr);
1.41 markus 1213: }
1214: }
1.25 markus 1215:
1.127 itojun 1216: static void
1.103 markus 1217: port_open_helper(Channel *c, char *rtype)
1218: {
1219: int direct;
1220: char buf[1024];
1221: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1222: int remote_port = get_peer_port(c->sock);
1.103 markus 1223:
1224: direct = (strcmp(rtype, "direct-tcpip") == 0);
1225:
1226: snprintf(buf, sizeof buf,
1227: "%s: listening port %d for %.100s port %d, "
1228: "connect from %.200s port %d",
1229: rtype, c->listening_port, c->path, c->host_port,
1230: remote_ipaddr, remote_port);
1231:
1232: xfree(c->remote_name);
1233: c->remote_name = xstrdup(buf);
1234:
1235: if (compat20) {
1236: packet_start(SSH2_MSG_CHANNEL_OPEN);
1237: packet_put_cstring(rtype);
1238: packet_put_int(c->self);
1239: packet_put_int(c->local_window_max);
1240: packet_put_int(c->local_maxpacket);
1241: if (direct) {
1242: /* target host, port */
1243: packet_put_cstring(c->path);
1244: packet_put_int(c->host_port);
1245: } else {
1246: /* listen address, port */
1247: packet_put_cstring(c->path);
1248: packet_put_int(c->listening_port);
1249: }
1250: /* originator host and port */
1251: packet_put_cstring(remote_ipaddr);
1.216 markus 1252: packet_put_int((u_int)remote_port);
1.103 markus 1253: packet_send();
1254: } else {
1255: packet_start(SSH_MSG_PORT_OPEN);
1256: packet_put_int(c->self);
1257: packet_put_cstring(c->path);
1258: packet_put_int(c->host_port);
1.121 markus 1259: if (packet_get_protocol_flags() &
1260: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1261: packet_put_cstring(c->remote_name);
1262: packet_send();
1263: }
1264: xfree(remote_ipaddr);
1265: }
1266:
1.226 djm 1267: static void
1268: channel_set_reuseaddr(int fd)
1269: {
1270: int on = 1;
1271:
1272: /*
1273: * Set socket options.
1274: * Allow local port reuse in TIME_WAIT.
1275: */
1276: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1277: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1278: }
1279:
1.41 markus 1280: /*
1281: * This socket is listening for connections to a forwarded TCP/IP port.
1282: */
1.127 itojun 1283: static void
1.41 markus 1284: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1285: {
1.103 markus 1286: Channel *nc;
1.41 markus 1287: struct sockaddr addr;
1.113 markus 1288: int newsock, nextstate;
1.41 markus 1289: socklen_t addrlen;
1.103 markus 1290: char *rtype;
1.73 markus 1291:
1.41 markus 1292: if (FD_ISSET(c->sock, readset)) {
1293: debug("Connection to port %d forwarding "
1294: "to %.100s port %d requested.",
1295: c->listening_port, c->path, c->host_port);
1.103 markus 1296:
1.137 markus 1297: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1298: nextstate = SSH_CHANNEL_OPENING;
1299: rtype = "forwarded-tcpip";
1300: } else {
1301: if (c->host_port == 0) {
1302: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1303: rtype = "dynamic-tcpip";
1.137 markus 1304: } else {
1305: nextstate = SSH_CHANNEL_OPENING;
1306: rtype = "direct-tcpip";
1307: }
1308: }
1.103 markus 1309:
1.41 markus 1310: addrlen = sizeof(addr);
1311: newsock = accept(c->sock, &addr, &addrlen);
1312: if (newsock < 0) {
1313: error("accept: %.100s", strerror(errno));
1314: return;
1315: }
1.169 stevesk 1316: set_nodelay(newsock);
1.190 markus 1317: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1318: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1319: nc->listening_port = c->listening_port;
1320: nc->host_port = c->host_port;
1321: strlcpy(nc->path, c->path, sizeof(nc->path));
1322:
1.137 markus 1323: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1324: /*
1325: * do not call the channel_post handler until
1326: * this flag has been reset by a pre-handler.
1327: * otherwise the FD_ISSET calls might overflow
1328: */
1329: nc->delayed = 1;
1330: } else {
1.103 markus 1331: port_open_helper(nc, rtype);
1.137 markus 1332: }
1.41 markus 1333: }
1334: }
1.25 markus 1335:
1.41 markus 1336: /*
1337: * This is the authentication agent socket listening for connections from
1338: * clients.
1339: */
1.127 itojun 1340: static void
1.41 markus 1341: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1342: {
1.113 markus 1343: Channel *nc;
1344: int newsock;
1.41 markus 1345: struct sockaddr addr;
1346: socklen_t addrlen;
1.25 markus 1347:
1.41 markus 1348: if (FD_ISSET(c->sock, readset)) {
1349: addrlen = sizeof(addr);
1350: newsock = accept(c->sock, &addr, &addrlen);
1351: if (newsock < 0) {
1352: error("accept from auth socket: %.100s", strerror(errno));
1353: return;
1354: }
1.113 markus 1355: nc = channel_new("accepted auth socket",
1.73 markus 1356: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1357: c->local_window_max, c->local_maxpacket,
1.190 markus 1358: 0, "accepted auth socket", 1);
1.73 markus 1359: if (compat20) {
1360: packet_start(SSH2_MSG_CHANNEL_OPEN);
1361: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1362: packet_put_int(nc->self);
1.73 markus 1363: packet_put_int(c->local_window_max);
1364: packet_put_int(c->local_maxpacket);
1365: } else {
1366: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1367: packet_put_int(nc->self);
1.73 markus 1368: }
1.41 markus 1369: packet_send();
1370: }
1371: }
1.25 markus 1372:
1.127 itojun 1373: static void
1.75 markus 1374: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1375: {
1.114 markus 1376: int err = 0;
1.129 stevesk 1377: socklen_t sz = sizeof(err);
1.114 markus 1378:
1.75 markus 1379: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1380: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1381: err = errno;
1382: error("getsockopt SO_ERROR failed");
1383: }
1384: if (err == 0) {
1385: debug("channel %d: connected", c->self);
1386: c->type = SSH_CHANNEL_OPEN;
1387: if (compat20) {
1388: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1389: packet_put_int(c->remote_id);
1390: packet_put_int(c->self);
1391: packet_put_int(c->local_window);
1392: packet_put_int(c->local_maxpacket);
1393: } else {
1394: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1395: packet_put_int(c->remote_id);
1396: packet_put_int(c->self);
1397: }
1.75 markus 1398: } else {
1.114 markus 1399: debug("channel %d: not connected: %s",
1400: c->self, strerror(err));
1401: if (compat20) {
1402: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1403: packet_put_int(c->remote_id);
1404: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1405: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1406: packet_put_cstring(strerror(err));
1407: packet_put_cstring("");
1408: }
1.75 markus 1409: } else {
1.114 markus 1410: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1411: packet_put_int(c->remote_id);
1.75 markus 1412: }
1.114 markus 1413: chan_mark_dead(c);
1.75 markus 1414: }
1.114 markus 1415: packet_send();
1.75 markus 1416: }
1417: }
1418:
1.127 itojun 1419: static int
1.41 markus 1420: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1421: {
1.214 markus 1422: char buf[CHAN_RBUF];
1.41 markus 1423: int len;
1.25 markus 1424:
1.118 markus 1425: if (c->rfd != -1 &&
1.41 markus 1426: FD_ISSET(c->rfd, readset)) {
1427: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1428: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1429: return 1;
1.41 markus 1430: if (len <= 0) {
1.194 markus 1431: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1432: c->self, c->rfd, len);
1.104 markus 1433: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1434: debug2("channel %d: not open", c->self);
1.113 markus 1435: chan_mark_dead(c);
1.103 markus 1436: return -1;
1.104 markus 1437: } else if (compat13) {
1.158 markus 1438: buffer_clear(&c->output);
1.41 markus 1439: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1440: debug2("channel %d: input draining.", c->self);
1.25 markus 1441: } else {
1.41 markus 1442: chan_read_failed(c);
1.25 markus 1443: }
1.41 markus 1444: return -1;
1445: }
1.143 deraadt 1446: if (c->input_filter != NULL) {
1.66 markus 1447: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1448: debug2("channel %d: filter stops", c->self);
1.65 markus 1449: chan_read_failed(c);
1450: }
1.228 reyk 1451: } else if (c->datagram) {
1452: buffer_put_string(&c->input, buf, len);
1.65 markus 1453: } else {
1454: buffer_append(&c->input, buf, len);
1455: }
1.41 markus 1456: }
1457: return 1;
1458: }
1.127 itojun 1459: static int
1.41 markus 1460: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1461: {
1.95 markus 1462: struct termios tio;
1.231 reyk 1463: u_char *data = NULL, *buf;
1.134 markus 1464: u_int dlen;
1.41 markus 1465: int len;
1.25 markus 1466:
1.41 markus 1467: /* Send buffered output data to the socket. */
1.118 markus 1468: if (c->wfd != -1 &&
1.41 markus 1469: FD_ISSET(c->wfd, writeset) &&
1470: buffer_len(&c->output) > 0) {
1.231 reyk 1471: if (c->output_filter != NULL) {
1472: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1473: debug2("channel %d: filter stops", c->self);
1.232 reyk 1474: if (c->type != SSH_CHANNEL_OPEN)
1475: chan_mark_dead(c);
1476: else
1477: chan_write_failed(c);
1478: return -1;
1.231 reyk 1479: }
1480: } else if (c->datagram) {
1481: buf = data = buffer_get_string(&c->output, &dlen);
1482: } else {
1483: buf = data = buffer_ptr(&c->output);
1484: dlen = buffer_len(&c->output);
1485: }
1486:
1.228 reyk 1487: if (c->datagram) {
1488: /* ignore truncated writes, datagrams might get lost */
1489: c->local_consumed += dlen + 4;
1.231 reyk 1490: len = write(c->wfd, buf, dlen);
1.228 reyk 1491: xfree(data);
1492: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1493: return 1;
1494: if (len <= 0) {
1495: if (c->type != SSH_CHANNEL_OPEN)
1496: chan_mark_dead(c);
1497: else
1498: chan_write_failed(c);
1499: return -1;
1500: }
1501: return 1;
1502: }
1.231 reyk 1503:
1504: len = write(c->wfd, buf, dlen);
1.53 markus 1505: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1506: return 1;
1.41 markus 1507: if (len <= 0) {
1.104 markus 1508: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1509: debug2("channel %d: not open", c->self);
1.113 markus 1510: chan_mark_dead(c);
1.104 markus 1511: return -1;
1512: } else if (compat13) {
1.158 markus 1513: buffer_clear(&c->output);
1.194 markus 1514: debug2("channel %d: input draining.", c->self);
1.41 markus 1515: c->type = SSH_CHANNEL_INPUT_DRAINING;
1516: } else {
1517: chan_write_failed(c);
1518: }
1519: return -1;
1.91 markus 1520: }
1.231 reyk 1521: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1522: if (tcgetattr(c->wfd, &tio) == 0 &&
1523: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1524: /*
1525: * Simulate echo to reduce the impact of
1.96 markus 1526: * traffic analysis. We need to match the
1.95 markus 1527: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1528: * (4 byte channel id + buf)
1.91 markus 1529: */
1.95 markus 1530: packet_send_ignore(4 + len);
1.91 markus 1531: packet_send();
1532: }
1.25 markus 1533: }
1.41 markus 1534: buffer_consume(&c->output, len);
1.44 markus 1535: if (compat20 && len > 0) {
1536: c->local_consumed += len;
1537: }
1538: }
1539: return 1;
1540: }
1.127 itojun 1541: static int
1.44 markus 1542: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1543: {
1.214 markus 1544: char buf[CHAN_RBUF];
1.44 markus 1545: int len;
1546:
1.45 markus 1547: /** XXX handle drain efd, too */
1.44 markus 1548: if (c->efd != -1) {
1549: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1550: FD_ISSET(c->efd, writeset) &&
1551: buffer_len(&c->extended) > 0) {
1552: len = write(c->efd, buffer_ptr(&c->extended),
1553: buffer_len(&c->extended));
1.70 markus 1554: debug2("channel %d: written %d to efd %d",
1.44 markus 1555: c->self, len, c->efd);
1.93 markus 1556: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1557: return 1;
1558: if (len <= 0) {
1559: debug2("channel %d: closing write-efd %d",
1560: c->self, c->efd);
1.132 markus 1561: channel_close_fd(&c->efd);
1.93 markus 1562: } else {
1.44 markus 1563: buffer_consume(&c->extended, len);
1564: c->local_consumed += len;
1565: }
1566: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1567: FD_ISSET(c->efd, readset)) {
1568: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1569: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1570: c->self, len, c->efd);
1.93 markus 1571: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1572: return 1;
1573: if (len <= 0) {
1574: debug2("channel %d: closing read-efd %d",
1.45 markus 1575: c->self, c->efd);
1.132 markus 1576: channel_close_fd(&c->efd);
1.93 markus 1577: } else {
1.44 markus 1578: buffer_append(&c->extended, buf, len);
1.93 markus 1579: }
1.44 markus 1580: }
1581: }
1582: return 1;
1583: }
1.127 itojun 1584: static int
1.204 djm 1585: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
1586: {
1587: char buf[16];
1588: int len;
1589:
1590: /* Monitor control fd to detect if the slave client exits */
1591: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1592: len = read(c->ctl_fd, buf, sizeof(buf));
1593: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1594: return 1;
1595: if (len <= 0) {
1596: debug2("channel %d: ctl read<=0", c->self);
1597: if (c->type != SSH_CHANNEL_OPEN) {
1598: debug2("channel %d: not open", c->self);
1599: chan_mark_dead(c);
1600: return -1;
1601: } else {
1602: chan_read_failed(c);
1603: chan_write_failed(c);
1604: }
1605: return -1;
1606: } else
1607: fatal("%s: unexpected data on ctl fd", __func__);
1608: }
1609: return 1;
1610: }
1611: static int
1.93 markus 1612: channel_check_window(Channel *c)
1.44 markus 1613: {
1.104 markus 1614: if (c->type == SSH_CHANNEL_OPEN &&
1615: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1616: c->local_window < c->local_window_max/2 &&
1617: c->local_consumed > 0) {
1618: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1619: packet_put_int(c->remote_id);
1620: packet_put_int(c->local_consumed);
1621: packet_send();
1.70 markus 1622: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1623: c->self, c->local_window,
1624: c->local_consumed);
1625: c->local_window += c->local_consumed;
1626: c->local_consumed = 0;
1.1 deraadt 1627: }
1.41 markus 1628: return 1;
1.1 deraadt 1629: }
1630:
1.127 itojun 1631: static void
1.157 markus 1632: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1633: {
1.137 markus 1634: if (c->delayed)
1635: return;
1.41 markus 1636: channel_handle_rfd(c, readset, writeset);
1637: channel_handle_wfd(c, readset, writeset);
1.157 markus 1638: if (!compat20)
1.137 markus 1639: return;
1.44 markus 1640: channel_handle_efd(c, readset, writeset);
1.204 djm 1641: channel_handle_ctl(c, readset, writeset);
1.93 markus 1642: channel_check_window(c);
1.44 markus 1643: }
1644:
1.127 itojun 1645: static void
1.41 markus 1646: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1647: {
1.41 markus 1648: int len;
1.180 deraadt 1649:
1.41 markus 1650: /* Send buffered output data to the socket. */
1651: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1652: len = write(c->sock, buffer_ptr(&c->output),
1653: buffer_len(&c->output));
1654: if (len <= 0)
1.158 markus 1655: buffer_clear(&c->output);
1.41 markus 1656: else
1657: buffer_consume(&c->output, len);
1658: }
1659: }
1.25 markus 1660:
1.127 itojun 1661: static void
1.44 markus 1662: channel_handler_init_20(void)
1663: {
1.157 markus 1664: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1665: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1666: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1667: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1668: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1669: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1670: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1671: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1672:
1.157 markus 1673: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1674: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1675: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1676: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1677: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1678: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1679: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1680: }
1681:
1.127 itojun 1682: static void
1.41 markus 1683: channel_handler_init_13(void)
1684: {
1685: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1686: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1687: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1688: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1689: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1690: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1691: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1692: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1693: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1694:
1.157 markus 1695: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1696: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1697: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1698: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1699: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1700: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1701: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1702: }
1.25 markus 1703:
1.127 itojun 1704: static void
1.41 markus 1705: channel_handler_init_15(void)
1706: {
1.157 markus 1707: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1708: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1709: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1710: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1711: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1712: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1713: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1714:
1.41 markus 1715: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1716: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1717: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1718: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1719: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1720: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1721: }
1.27 markus 1722:
1.127 itojun 1723: static void
1.41 markus 1724: channel_handler_init(void)
1725: {
1726: int i;
1.180 deraadt 1727:
1.148 deraadt 1728: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1729: channel_pre[i] = NULL;
1730: channel_post[i] = NULL;
1731: }
1.44 markus 1732: if (compat20)
1733: channel_handler_init_20();
1734: else if (compat13)
1.41 markus 1735: channel_handler_init_13();
1736: else
1737: channel_handler_init_15();
1738: }
1.25 markus 1739:
1.140 markus 1740: /* gc dead channels */
1741: static void
1742: channel_garbage_collect(Channel *c)
1743: {
1744: if (c == NULL)
1745: return;
1746: if (c->detach_user != NULL) {
1.225 djm 1747: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1748: return;
1.194 markus 1749: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1750: c->detach_user(c->self, NULL);
1751: /* if we still have a callback */
1752: if (c->detach_user != NULL)
1753: return;
1.194 markus 1754: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1755: }
1756: if (!chan_is_dead(c, 1))
1757: return;
1.194 markus 1758: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1759: channel_free(c);
1760: }
1761:
1.127 itojun 1762: static void
1.41 markus 1763: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1764: {
1765: static int did_init = 0;
1.209 avsm 1766: u_int i;
1.41 markus 1767: Channel *c;
1.25 markus 1768:
1.41 markus 1769: if (!did_init) {
1770: channel_handler_init();
1771: did_init = 1;
1772: }
1773: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1774: c = channels[i];
1775: if (c == NULL)
1.41 markus 1776: continue;
1.118 markus 1777: if (ftab[c->type] != NULL)
1778: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1779: channel_garbage_collect(c);
1.1 deraadt 1780: }
1781: }
1782:
1.121 markus 1783: /*
1784: * Allocate/update select bitmasks and add any bits relevant to channels in
1785: * select bitmasks.
1786: */
1.49 markus 1787: void
1.100 markus 1788: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1789: u_int *nallocp, int rekeying)
1.41 markus 1790: {
1.209 avsm 1791: u_int n, sz;
1.84 markus 1792:
1793: n = MAX(*maxfdp, channel_max_fd);
1794:
1795: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1796: /* perhaps check sz < nalloc/2 and shrink? */
1797: if (*readsetp == NULL || sz > *nallocp) {
1798: *readsetp = xrealloc(*readsetp, sz);
1799: *writesetp = xrealloc(*writesetp, sz);
1800: *nallocp = sz;
1.84 markus 1801: }
1.132 markus 1802: *maxfdp = n;
1.84 markus 1803: memset(*readsetp, 0, sz);
1804: memset(*writesetp, 0, sz);
1805:
1.100 markus 1806: if (!rekeying)
1807: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1808: }
1809:
1.121 markus 1810: /*
1811: * After select, perform any appropriate operations for channels which have
1812: * events pending.
1813: */
1.49 markus 1814: void
1.41 markus 1815: channel_after_select(fd_set * readset, fd_set * writeset)
1816: {
1817: channel_handler(channel_post, readset, writeset);
1818: }
1819:
1.121 markus 1820:
1.84 markus 1821: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1822:
1.49 markus 1823: void
1.142 itojun 1824: channel_output_poll(void)
1.1 deraadt 1825: {
1.41 markus 1826: Channel *c;
1.209 avsm 1827: u_int i, len;
1.1 deraadt 1828:
1.25 markus 1829: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1830: c = channels[i];
1831: if (c == NULL)
1832: continue;
1.37 markus 1833:
1.121 markus 1834: /*
1835: * We are only interested in channels that can have buffered
1836: * incoming data.
1837: */
1.37 markus 1838: if (compat13) {
1.41 markus 1839: if (c->type != SSH_CHANNEL_OPEN &&
1840: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1841: continue;
1842: } else {
1.41 markus 1843: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1844: continue;
1845: }
1.46 markus 1846: if (compat20 &&
1847: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1848: /* XXX is this true? */
1.140 markus 1849: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1850: continue;
1851: }
1.25 markus 1852:
1853: /* Get the amount of buffered data for this channel. */
1.93 markus 1854: if ((c->istate == CHAN_INPUT_OPEN ||
1855: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1856: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1857: if (c->datagram) {
1858: if (len > 0) {
1859: u_char *data;
1860: u_int dlen;
1861:
1862: data = buffer_get_string(&c->input,
1863: &dlen);
1864: packet_start(SSH2_MSG_CHANNEL_DATA);
1865: packet_put_int(c->remote_id);
1866: packet_put_string(data, dlen);
1867: packet_send();
1868: c->remote_window -= dlen + 4;
1869: xfree(data);
1870: }
1871: continue;
1872: }
1.121 markus 1873: /*
1874: * Send some data for the other side over the secure
1875: * connection.
1876: */
1.44 markus 1877: if (compat20) {
1878: if (len > c->remote_window)
1879: len = c->remote_window;
1880: if (len > c->remote_maxpacket)
1881: len = c->remote_maxpacket;
1.25 markus 1882: } else {
1.44 markus 1883: if (packet_is_interactive()) {
1884: if (len > 1024)
1885: len = 512;
1886: } else {
1887: /* Keep the packets at reasonable size. */
1888: if (len > packet_get_maxsize()/2)
1889: len = packet_get_maxsize()/2;
1890: }
1.25 markus 1891: }
1.41 markus 1892: if (len > 0) {
1.44 markus 1893: packet_start(compat20 ?
1894: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1895: packet_put_int(c->remote_id);
1896: packet_put_string(buffer_ptr(&c->input), len);
1897: packet_send();
1898: buffer_consume(&c->input, len);
1899: c->remote_window -= len;
1900: }
1901: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1902: if (compat13)
1903: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1904: /*
1905: * input-buffer is empty and read-socket shutdown:
1.172 markus 1906: * tell peer, that we will not send more data: send IEOF.
1907: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1908: */
1.172 markus 1909: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1910: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1911: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1912: else
1913: chan_ibuf_empty(c);
1.25 markus 1914: }
1.44 markus 1915: /* Send extended data, i.e. stderr */
1916: if (compat20 &&
1.172 markus 1917: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1918: c->remote_window > 0 &&
1919: (len = buffer_len(&c->extended)) > 0 &&
1920: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1921: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1922: c->self, c->remote_window, buffer_len(&c->extended),
1923: c->extended_usage);
1.44 markus 1924: if (len > c->remote_window)
1925: len = c->remote_window;
1926: if (len > c->remote_maxpacket)
1927: len = c->remote_maxpacket;
1928: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1929: packet_put_int(c->remote_id);
1930: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1931: packet_put_string(buffer_ptr(&c->extended), len);
1932: packet_send();
1933: buffer_consume(&c->extended, len);
1934: c->remote_window -= len;
1.93 markus 1935: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1936: }
1.25 markus 1937: }
1.1 deraadt 1938: }
1939:
1.121 markus 1940:
1941: /* -- protocol input */
1.1 deraadt 1942:
1.49 markus 1943: void
1.154 markus 1944: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1945: {
1.37 markus 1946: int id;
1.25 markus 1947: char *data;
1.77 markus 1948: u_int data_len;
1.41 markus 1949: Channel *c;
1.25 markus 1950:
1951: /* Get the channel number and verify it. */
1.37 markus 1952: id = packet_get_int();
1.41 markus 1953: c = channel_lookup(id);
1954: if (c == NULL)
1.37 markus 1955: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1956:
1957: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1958: if (c->type != SSH_CHANNEL_OPEN &&
1959: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1960: return;
1961:
1.25 markus 1962: /* Get the data. */
1963: data = packet_get_string(&data_len);
1.200 markus 1964:
1965: /*
1966: * Ignore data for protocol > 1.3 if output end is no longer open.
1967: * For protocol 2 the sending side is reducing its window as it sends
1968: * data, so we must 'fake' consumption of the data in order to ensure
1969: * that window updates are sent back. Otherwise the connection might
1970: * deadlock.
1971: */
1972: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1973: if (compat20) {
1974: c->local_window -= data_len;
1975: c->local_consumed += data_len;
1976: }
1977: xfree(data);
1978: return;
1979: }
1.41 markus 1980:
1.143 deraadt 1981: if (compat20) {
1.44 markus 1982: if (data_len > c->local_maxpacket) {
1.188 itojun 1983: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1984: c->self, data_len, c->local_maxpacket);
1985: }
1986: if (data_len > c->local_window) {
1.188 itojun 1987: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1988: c->self, data_len, c->local_window);
1989: xfree(data);
1990: return;
1991: }
1992: c->local_window -= data_len;
1993: }
1.152 markus 1994: packet_check_eom();
1.228 reyk 1995: if (c->datagram)
1996: buffer_put_string(&c->output, data, data_len);
1997: else
1998: buffer_append(&c->output, data, data_len);
1.25 markus 1999: xfree(data);
1.1 deraadt 2000: }
1.121 markus 2001:
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:
1.49 markus 2048: void
1.154 markus 2049: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2050: {
2051: int id;
2052: Channel *c;
2053:
2054: id = packet_get_int();
1.152 markus 2055: packet_check_eom();
1.41 markus 2056: c = channel_lookup(id);
2057: if (c == NULL)
2058: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2059: chan_rcvd_ieof(c);
1.133 markus 2060:
2061: /* XXX force input close */
1.156 markus 2062: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2063: debug("channel %d: FORCE input drain", c->self);
2064: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2065: if (buffer_len(&c->input) == 0)
2066: chan_ibuf_empty(c);
1.133 markus 2067: }
2068:
1.41 markus 2069: }
1.1 deraadt 2070:
1.49 markus 2071: void
1.154 markus 2072: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2073: {
1.41 markus 2074: int id;
2075: Channel *c;
1.1 deraadt 2076:
1.41 markus 2077: id = packet_get_int();
1.152 markus 2078: packet_check_eom();
1.41 markus 2079: c = channel_lookup(id);
2080: if (c == NULL)
2081: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2082:
2083: /*
2084: * Send a confirmation that we have closed the channel and no more
2085: * data is coming for it.
2086: */
1.25 markus 2087: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2088: packet_put_int(c->remote_id);
1.25 markus 2089: packet_send();
2090:
1.27 markus 2091: /*
2092: * If the channel is in closed state, we have sent a close request,
2093: * and the other side will eventually respond with a confirmation.
2094: * Thus, we cannot free the channel here, because then there would be
2095: * no-one to receive the confirmation. The channel gets freed when
2096: * the confirmation arrives.
2097: */
1.41 markus 2098: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2099: /*
2100: * Not a closed channel - mark it as draining, which will
2101: * cause it to be freed later.
2102: */
1.158 markus 2103: buffer_clear(&c->input);
1.41 markus 2104: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2105: }
1.1 deraadt 2106: }
2107:
1.41 markus 2108: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 2109: void
1.154 markus 2110: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2111: {
2112: int id = packet_get_int();
2113: Channel *c = channel_lookup(id);
1.151 markus 2114:
1.152 markus 2115: packet_check_eom();
1.41 markus 2116: if (c == NULL)
2117: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2118: chan_rcvd_oclose(c);
2119: }
1.1 deraadt 2120:
1.49 markus 2121: void
1.154 markus 2122: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2123: {
1.41 markus 2124: int id = packet_get_int();
2125: Channel *c = channel_lookup(id);
1.1 deraadt 2126:
1.152 markus 2127: packet_check_eom();
1.41 markus 2128: if (c == NULL)
2129: packet_disconnect("Received close confirmation for "
2130: "out-of-range channel %d.", id);
2131: if (c->type != SSH_CHANNEL_CLOSED)
2132: packet_disconnect("Received close confirmation for "
2133: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2134: channel_free(c);
1.1 deraadt 2135: }
2136:
1.49 markus 2137: void
1.154 markus 2138: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2139: {
1.41 markus 2140: int id, remote_id;
2141: Channel *c;
1.1 deraadt 2142:
1.41 markus 2143: id = packet_get_int();
2144: c = channel_lookup(id);
1.25 markus 2145:
1.41 markus 2146: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2147: packet_disconnect("Received open confirmation for "
2148: "non-opening channel %d.", id);
2149: remote_id = packet_get_int();
1.27 markus 2150: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2151: c->remote_id = remote_id;
2152: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2153:
2154: if (compat20) {
2155: c->remote_window = packet_get_int();
2156: c->remote_maxpacket = packet_get_int();
1.165 markus 2157: if (c->confirm) {
1.70 markus 2158: debug2("callback start");
1.204 djm 2159: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2160: debug2("callback done");
1.44 markus 2161: }
1.194 markus 2162: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2163: c->remote_window, c->remote_maxpacket);
2164: }
1.152 markus 2165: packet_check_eom();
1.1 deraadt 2166: }
2167:
1.127 itojun 2168: static char *
1.114 markus 2169: reason2txt(int reason)
2170: {
1.143 deraadt 2171: switch (reason) {
1.114 markus 2172: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2173: return "administratively prohibited";
2174: case SSH2_OPEN_CONNECT_FAILED:
2175: return "connect failed";
2176: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2177: return "unknown channel type";
2178: case SSH2_OPEN_RESOURCE_SHORTAGE:
2179: return "resource shortage";
2180: }
1.117 stevesk 2181: return "unknown reason";
1.114 markus 2182: }
2183:
1.49 markus 2184: void
1.154 markus 2185: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2186: {
1.86 markus 2187: int id, reason;
2188: char *msg = NULL, *lang = NULL;
1.41 markus 2189: Channel *c;
2190:
2191: id = packet_get_int();
2192: c = channel_lookup(id);
1.25 markus 2193:
1.41 markus 2194: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2195: packet_disconnect("Received open failure for "
2196: "non-opening channel %d.", id);
1.44 markus 2197: if (compat20) {
1.86 markus 2198: reason = packet_get_int();
1.110 markus 2199: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2200: msg = packet_get_string(NULL);
2201: lang = packet_get_string(NULL);
2202: }
1.188 itojun 2203: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2204: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2205: if (msg != NULL)
2206: xfree(msg);
2207: if (lang != NULL)
2208: xfree(lang);
1.44 markus 2209: }
1.152 markus 2210: packet_check_eom();
1.25 markus 2211: /* Free the channel. This will also close the socket. */
1.113 markus 2212: channel_free(c);
1.44 markus 2213: }
2214:
1.121 markus 2215: void
1.154 markus 2216: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2217: {
2218: Channel *c;
1.178 markus 2219: int id;
2220: u_int adjust;
1.121 markus 2221:
2222: if (!compat20)
2223: return;
2224:
2225: /* Get the channel number and verify it. */
2226: id = packet_get_int();
2227: c = channel_lookup(id);
1.1 deraadt 2228:
1.229 markus 2229: if (c == NULL) {
2230: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2231: return;
2232: }
2233: adjust = packet_get_int();
1.152 markus 2234: packet_check_eom();
1.178 markus 2235: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2236: c->remote_window += adjust;
2237: }
1.1 deraadt 2238:
1.121 markus 2239: void
1.154 markus 2240: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2241: {
1.121 markus 2242: Channel *c = NULL;
2243: u_short host_port;
2244: char *host, *originator_string;
2245: int remote_id, sock = -1;
2246:
2247: remote_id = packet_get_int();
2248: host = packet_get_string(NULL);
2249: host_port = packet_get_int();
1.25 markus 2250:
1.121 markus 2251: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2252: originator_string = packet_get_string(NULL);
2253: } else {
2254: originator_string = xstrdup("unknown (remote did not supply name)");
2255: }
1.152 markus 2256: packet_check_eom();
1.121 markus 2257: sock = channel_connect_to(host, host_port);
2258: if (sock != -1) {
2259: c = channel_new("connected socket",
2260: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2261: originator_string, 1);
1.167 markus 2262: c->remote_id = remote_id;
1.25 markus 2263: }
1.190 markus 2264: xfree(originator_string);
1.121 markus 2265: if (c == NULL) {
2266: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2267: packet_put_int(remote_id);
2268: packet_send();
2269: }
2270: xfree(host);
1.1 deraadt 2271: }
2272:
1.121 markus 2273:
2274: /* -- tcp forwarding */
1.135 markus 2275:
2276: void
2277: channel_set_af(int af)
2278: {
2279: IPv4or6 = af;
2280: }
1.121 markus 2281:
1.160 markus 2282: static int
2283: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2284: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2285: {
1.113 markus 2286: Channel *c;
1.226 djm 2287: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2288: struct addrinfo hints, *ai, *aitop;
1.212 djm 2289: const char *host, *addr;
1.35 markus 2290: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2291:
1.160 markus 2292: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2293: listen_addr : host_to_connect;
1.212 djm 2294: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2295:
1.160 markus 2296: if (host == NULL) {
2297: error("No forward host name.");
1.218 markus 2298: return 0;
1.73 markus 2299: }
1.113 markus 2300: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2301: error("Forward host name too long.");
1.218 markus 2302: return 0;
1.87 markus 2303: }
1.25 markus 2304:
1.28 markus 2305: /*
1.212 djm 2306: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2307: * specified address or wildcard. On the client, a specified bind
2308: * address will always override gateway_ports. On the server, a
2309: * gateway_ports of 1 (``yes'') will override the client's
2310: * specification and force a wildcard bind, whereas a value of 2
2311: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2312: * asked for.
2313: *
2314: * Special-case listen_addrs are:
2315: *
2316: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2317: * "" (empty string), "*" -> wildcard v4/v6
2318: * "localhost" -> loopback v4/v6
2319: */
2320: addr = NULL;
2321: if (listen_addr == NULL) {
2322: /* No address specified: default to gateway_ports setting */
2323: if (gateway_ports)
2324: wildcard = 1;
2325: } else if (gateway_ports || is_client) {
2326: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2327: strcmp(listen_addr, "0.0.0.0") == 0) ||
2328: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2329: (!is_client && gateway_ports == 1))
2330: wildcard = 1;
2331: else if (strcmp(listen_addr, "localhost") != 0)
2332: addr = listen_addr;
2333: }
2334:
2335: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2336: type, wildcard, (addr == NULL) ? "NULL" : addr);
2337:
2338: /*
1.35 markus 2339: * getaddrinfo returns a loopback address if the hostname is
2340: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2341: */
1.35 markus 2342: memset(&hints, 0, sizeof(hints));
2343: hints.ai_family = IPv4or6;
1.212 djm 2344: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2345: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2346: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2347: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2348: if (addr == NULL) {
2349: /* This really shouldn't happen */
2350: packet_disconnect("getaddrinfo: fatal error: %s",
2351: gai_strerror(r));
2352: } else {
1.218 markus 2353: error("channel_setup_fwd_listener: "
1.212 djm 2354: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2355: }
1.218 markus 2356: return 0;
1.212 djm 2357: }
1.35 markus 2358:
2359: for (ai = aitop; ai; ai = ai->ai_next) {
2360: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2361: continue;
2362: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2363: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2364: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2365: continue;
2366: }
2367: /* Create a port to listen for the host. */
1.189 markus 2368: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2369: if (sock < 0) {
2370: /* this is no error since kernel may not support ipv6 */
2371: verbose("socket: %.100s", strerror(errno));
2372: continue;
2373: }
1.226 djm 2374:
2375: channel_set_reuseaddr(sock);
1.182 stevesk 2376:
1.35 markus 2377: debug("Local forwarding listening on %s port %s.", ntop, strport);
2378:
2379: /* Bind the socket to the address. */
2380: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2381: /* address can be in use ipv6 address is already bound */
2382: verbose("bind: %.100s", strerror(errno));
2383: close(sock);
2384: continue;
2385: }
2386: /* Start listening for connections on the socket. */
1.199 markus 2387: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2388: error("listen: %.100s", strerror(errno));
2389: close(sock);
2390: continue;
2391: }
2392: /* Allocate a channel number for the socket. */
1.121 markus 2393: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2394: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2395: 0, "port listener", 1);
1.113 markus 2396: strlcpy(c->path, host, sizeof(c->path));
2397: c->host_port = port_to_connect;
2398: c->listening_port = listen_port;
1.35 markus 2399: success = 1;
2400: }
2401: if (success == 0)
1.160 markus 2402: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2403: listen_port);
1.35 markus 2404: freeaddrinfo(aitop);
1.87 markus 2405: return success;
1.25 markus 2406: }
1.1 deraadt 2407:
1.202 djm 2408: int
2409: channel_cancel_rport_listener(const char *host, u_short port)
2410: {
1.209 avsm 2411: u_int i;
2412: int found = 0;
1.202 djm 2413:
1.213 deraadt 2414: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2415: Channel *c = channels[i];
2416:
2417: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2418: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2419: c->listening_port == port) {
1.210 djm 2420: debug2("%s: close channel %d", __func__, i);
1.202 djm 2421: channel_free(c);
2422: found = 1;
2423: }
2424: }
2425:
2426: return (found);
2427: }
2428:
1.160 markus 2429: /* protocol local port fwd, used by ssh (and sshd in v1) */
2430: int
1.212 djm 2431: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2432: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2433: {
2434: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2435: listen_host, listen_port, host_to_connect, port_to_connect,
2436: gateway_ports);
1.160 markus 2437: }
2438:
2439: /* protocol v2 remote port fwd, used by sshd */
2440: int
2441: channel_setup_remote_fwd_listener(const char *listen_address,
2442: u_short listen_port, int gateway_ports)
2443: {
2444: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2445: listen_address, listen_port, NULL, 0, gateway_ports);
2446: }
2447:
1.27 markus 2448: /*
2449: * Initiate forwarding of connections to port "port" on remote host through
2450: * the secure channel to host:port from local side.
2451: */
1.1 deraadt 2452:
1.49 markus 2453: void
1.212 djm 2454: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2455: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2456: {
1.153 markus 2457: int type, success = 0;
1.73 markus 2458:
1.25 markus 2459: /* Record locally that connection to this host/port is permitted. */
2460: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2461: fatal("channel_request_remote_forwarding: too many forwards");
2462:
2463: /* Send the forward request to the remote side. */
1.44 markus 2464: if (compat20) {
1.212 djm 2465: const char *address_to_bind;
2466: if (listen_host == NULL)
2467: address_to_bind = "localhost";
2468: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2469: address_to_bind = "";
2470: else
2471: address_to_bind = listen_host;
2472:
1.44 markus 2473: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2474: packet_put_cstring("tcpip-forward");
1.173 markus 2475: packet_put_char(1); /* boolean: want reply */
1.44 markus 2476: packet_put_cstring(address_to_bind);
2477: packet_put_int(listen_port);
1.73 markus 2478: packet_send();
2479: packet_write_wait();
2480: /* Assume that server accepts the request */
2481: success = 1;
1.44 markus 2482: } else {
2483: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2484: packet_put_int(listen_port);
2485: packet_put_cstring(host_to_connect);
1.44 markus 2486: packet_put_int(port_to_connect);
2487: packet_send();
2488: packet_write_wait();
1.73 markus 2489:
2490: /* Wait for response from the remote side. */
1.153 markus 2491: type = packet_read();
1.73 markus 2492: switch (type) {
2493: case SSH_SMSG_SUCCESS:
2494: success = 1;
2495: break;
2496: case SSH_SMSG_FAILURE:
1.188 itojun 2497: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2498: break;
2499: default:
2500: /* Unknown packet */
2501: packet_disconnect("Protocol error for port forward request:"
2502: "received packet type %d.", type);
2503: }
2504: }
2505: if (success) {
2506: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2507: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2508: permitted_opens[num_permitted_opens].listen_port = listen_port;
2509: num_permitted_opens++;
1.44 markus 2510: }
1.1 deraadt 2511: }
2512:
1.27 markus 2513: /*
1.208 deraadt 2514: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2515: * local side.
2516: */
2517: void
1.212 djm 2518: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2519: {
2520: int i;
2521:
2522: if (!compat20)
2523: return;
2524:
2525: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2526: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2527: permitted_opens[i].listen_port == port)
2528: break;
2529: }
2530: if (i >= num_permitted_opens) {
2531: debug("%s: requested forward not found", __func__);
2532: return;
2533: }
2534: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2535: packet_put_cstring("cancel-tcpip-forward");
2536: packet_put_char(0);
1.212 djm 2537: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2538: packet_put_int(port);
2539: packet_send();
2540:
2541: permitted_opens[i].listen_port = 0;
2542: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2543: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2544: permitted_opens[i].host_to_connect = NULL;
2545: }
2546:
2547: /*
1.27 markus 2548: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2549: * listening for the port, and sends back a success reply (or disconnect
2550: * message if there was an error). This never returns if there was an error.
2551: */
1.1 deraadt 2552:
1.49 markus 2553: void
1.56 markus 2554: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2555: {
1.31 markus 2556: u_short port, host_port;
1.25 markus 2557: char *hostname;
1.1 deraadt 2558:
1.25 markus 2559: /* Get arguments from the packet. */
2560: port = packet_get_int();
2561: hostname = packet_get_string(NULL);
2562: host_port = packet_get_int();
2563:
1.27 markus 2564: /*
2565: * Check that an unprivileged user is not trying to forward a
2566: * privileged port.
2567: */
1.25 markus 2568: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2569: packet_disconnect(
2570: "Requested forwarding of port %d but user is not root.",
2571: port);
2572: if (host_port == 0)
2573: packet_disconnect("Dynamic forwarding denied.");
2574:
1.73 markus 2575: /* Initiate forwarding */
1.212 djm 2576: channel_setup_local_fwd_listener(NULL, port, hostname,
2577: host_port, gateway_ports);
1.25 markus 2578:
2579: /* Free the argument string. */
2580: xfree(hostname);
1.1 deraadt 2581: }
2582:
1.99 markus 2583: /*
2584: * Permits opening to any host/port if permitted_opens[] is empty. This is
2585: * usually called by the server, because the user could connect to any port
2586: * anyway, and the server has no way to know but to trust the client anyway.
2587: */
2588: void
1.142 itojun 2589: channel_permit_all_opens(void)
1.99 markus 2590: {
2591: if (num_permitted_opens == 0)
2592: all_opens_permitted = 1;
2593: }
2594:
1.101 markus 2595: void
1.99 markus 2596: channel_add_permitted_opens(char *host, int port)
2597: {
2598: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2599: fatal("channel_request_remote_forwarding: too many forwards");
2600: debug("allow port forwarding to host %s port %d", host, port);
2601:
2602: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2603: permitted_opens[num_permitted_opens].port_to_connect = port;
2604: num_permitted_opens++;
2605:
2606: all_opens_permitted = 0;
2607: }
2608:
1.101 markus 2609: void
1.99 markus 2610: channel_clear_permitted_opens(void)
2611: {
2612: int i;
2613:
2614: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2615: if (permitted_opens[i].host_to_connect != NULL)
2616: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2617: num_permitted_opens = 0;
2618:
2619: }
2620:
2621:
2622: /* return socket to remote host, port */
1.127 itojun 2623: static int
1.99 markus 2624: connect_to(const char *host, u_short port)
1.41 markus 2625: {
2626: struct addrinfo hints, *ai, *aitop;
2627: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2628: int gaierr;
2629: int sock = -1;
2630:
2631: memset(&hints, 0, sizeof(hints));
2632: hints.ai_family = IPv4or6;
2633: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2634: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2635: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2636: error("connect_to %.100s: unknown host (%s)", host,
2637: gai_strerror(gaierr));
1.41 markus 2638: return -1;
2639: }
2640: for (ai = aitop; ai; ai = ai->ai_next) {
2641: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2642: continue;
2643: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2644: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2645: error("connect_to: getnameinfo failed");
1.41 markus 2646: continue;
2647: }
1.189 markus 2648: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2649: if (sock < 0) {
1.186 djm 2650: if (ai->ai_next == NULL)
2651: error("socket: %.100s", strerror(errno));
2652: else
2653: verbose("socket: %.100s", strerror(errno));
1.41 markus 2654: continue;
2655: }
1.205 djm 2656: if (set_nonblock(sock) == -1)
2657: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2658: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2659: errno != EINPROGRESS) {
1.99 markus 2660: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2661: strerror(errno));
2662: close(sock);
1.89 stevesk 2663: continue; /* fail -- try next */
1.41 markus 2664: }
2665: break; /* success */
2666:
2667: }
2668: freeaddrinfo(aitop);
2669: if (!ai) {
1.99 markus 2670: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2671: return -1;
2672: }
2673: /* success */
1.169 stevesk 2674: set_nodelay(sock);
1.41 markus 2675: return sock;
2676: }
1.99 markus 2677:
1.73 markus 2678: int
1.130 stevesk 2679: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2680: {
2681: int i;
1.99 markus 2682:
1.73 markus 2683: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2684: if (permitted_opens[i].host_to_connect != NULL &&
2685: permitted_opens[i].listen_port == listen_port)
1.99 markus 2686: return connect_to(
1.73 markus 2687: permitted_opens[i].host_to_connect,
2688: permitted_opens[i].port_to_connect);
1.74 markus 2689: error("WARNING: Server requests forwarding for unknown listen_port %d",
2690: listen_port);
1.73 markus 2691: return -1;
2692: }
2693:
1.99 markus 2694: /* Check if connecting to that port is permitted and connect. */
2695: int
2696: channel_connect_to(const char *host, u_short port)
2697: {
2698: int i, permit;
2699:
2700: permit = all_opens_permitted;
2701: if (!permit) {
2702: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2703: if (permitted_opens[i].host_to_connect != NULL &&
2704: permitted_opens[i].port_to_connect == port &&
1.99 markus 2705: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2706: permit = 1;
2707:
2708: }
2709: if (!permit) {
1.188 itojun 2710: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2711: "but the request was denied.", host, port);
2712: return -1;
2713: }
2714: return connect_to(host, port);
1.204 djm 2715: }
2716:
2717: void
2718: channel_send_window_changes(void)
2719: {
1.209 avsm 2720: u_int i;
1.204 djm 2721: struct winsize ws;
2722:
2723: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2724: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2725: channels[i]->type != SSH_CHANNEL_OPEN)
2726: continue;
2727: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2728: continue;
2729: channel_request_start(i, "window-change", 0);
2730: packet_put_int(ws.ws_col);
2731: packet_put_int(ws.ws_row);
2732: packet_put_int(ws.ws_xpixel);
2733: packet_put_int(ws.ws_ypixel);
2734: packet_send();
2735: }
1.99 markus 2736: }
2737:
1.121 markus 2738: /* -- X11 forwarding */
1.1 deraadt 2739:
1.27 markus 2740: /*
2741: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2742: * Returns 0 and a suitable display number for the DISPLAY variable
2743: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2744: */
1.141 stevesk 2745: int
1.163 stevesk 2746: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2747: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2748: {
1.149 markus 2749: Channel *nc = NULL;
1.31 markus 2750: int display_number, sock;
2751: u_short port;
1.35 markus 2752: struct addrinfo hints, *ai, *aitop;
2753: char strport[NI_MAXSERV];
2754: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2755:
1.224 markus 2756: if (chanids == NULL)
2757: return -1;
2758:
1.33 markus 2759: for (display_number = x11_display_offset;
1.148 deraadt 2760: display_number < MAX_DISPLAYS;
2761: display_number++) {
1.25 markus 2762: port = 6000 + display_number;
1.35 markus 2763: memset(&hints, 0, sizeof(hints));
2764: hints.ai_family = IPv4or6;
1.163 stevesk 2765: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2766: hints.ai_socktype = SOCK_STREAM;
2767: snprintf(strport, sizeof strport, "%d", port);
2768: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2769: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2770: return -1;
1.25 markus 2771: }
1.35 markus 2772: for (ai = aitop; ai; ai = ai->ai_next) {
2773: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2774: continue;
1.189 markus 2775: sock = socket(ai->ai_family, ai->ai_socktype,
2776: ai->ai_protocol);
1.35 markus 2777: if (sock < 0) {
2778: error("socket: %.100s", strerror(errno));
1.203 markus 2779: freeaddrinfo(aitop);
1.141 stevesk 2780: return -1;
1.35 markus 2781: }
1.226 djm 2782: channel_set_reuseaddr(sock);
1.35 markus 2783: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2784: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2785: close(sock);
1.183 itojun 2786:
2787: if (ai->ai_next)
2788: continue;
2789:
1.35 markus 2790: for (n = 0; n < num_socks; n++) {
2791: close(socks[n]);
2792: }
2793: num_socks = 0;
2794: break;
2795: }
2796: socks[num_socks++] = sock;
2797: if (num_socks == NUM_SOCKS)
2798: break;
1.25 markus 2799: }
1.83 stevesk 2800: freeaddrinfo(aitop);
1.35 markus 2801: if (num_socks > 0)
2802: break;
1.25 markus 2803: }
2804: if (display_number >= MAX_DISPLAYS) {
2805: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2806: return -1;
1.25 markus 2807: }
2808: /* Start listening for connections on the socket. */
1.35 markus 2809: for (n = 0; n < num_socks; n++) {
2810: sock = socks[n];
1.199 markus 2811: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2812: error("listen: %.100s", strerror(errno));
2813: close(sock);
1.141 stevesk 2814: return -1;
1.35 markus 2815: }
1.25 markus 2816: }
1.35 markus 2817:
2818: /* Allocate a channel for each socket. */
1.224 markus 2819: *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1));
1.35 markus 2820: for (n = 0; n < num_socks; n++) {
2821: sock = socks[n];
1.149 markus 2822: nc = channel_new("x11 listener",
1.51 markus 2823: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2824: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2825: 0, "X11 inet listener", 1);
1.167 markus 2826: nc->single_connection = single_connection;
1.224 markus 2827: (*chanids)[n] = nc->self;
1.35 markus 2828: }
1.224 markus 2829: (*chanids)[n] = -1;
1.1 deraadt 2830:
1.141 stevesk 2831: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2832: *display_numberp = display_number;
2833: return (0);
1.1 deraadt 2834: }
2835:
1.127 itojun 2836: static int
1.77 markus 2837: connect_local_xsocket(u_int dnr)
1.1 deraadt 2838: {
1.25 markus 2839: int sock;
2840: struct sockaddr_un addr;
2841:
1.147 stevesk 2842: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2843: if (sock < 0)
2844: error("socket: %.100s", strerror(errno));
2845: memset(&addr, 0, sizeof(addr));
2846: addr.sun_family = AF_UNIX;
2847: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2848: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2849: return sock;
2850: close(sock);
1.25 markus 2851: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2852: return -1;
1.1 deraadt 2853: }
2854:
1.51 markus 2855: int
2856: x11_connect_display(void)
1.1 deraadt 2857: {
1.162 stevesk 2858: int display_number, sock = 0;
1.25 markus 2859: const char *display;
1.51 markus 2860: char buf[1024], *cp;
1.35 markus 2861: struct addrinfo hints, *ai, *aitop;
2862: char strport[NI_MAXSERV];
2863: int gaierr;
1.25 markus 2864:
2865: /* Try to open a socket for the local X server. */
2866: display = getenv("DISPLAY");
2867: if (!display) {
2868: error("DISPLAY not set.");
1.51 markus 2869: return -1;
1.25 markus 2870: }
1.27 markus 2871: /*
2872: * Now we decode the value of the DISPLAY variable and make a
2873: * connection to the real X server.
2874: */
2875:
2876: /*
2877: * Check if it is a unix domain socket. Unix domain displays are in
2878: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2879: */
1.25 markus 2880: if (strncmp(display, "unix:", 5) == 0 ||
2881: display[0] == ':') {
2882: /* Connect to the unix domain socket. */
2883: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2884: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2885: display);
1.51 markus 2886: return -1;
1.25 markus 2887: }
2888: /* Create a socket. */
2889: sock = connect_local_xsocket(display_number);
2890: if (sock < 0)
1.51 markus 2891: return -1;
1.25 markus 2892:
2893: /* OK, we now have a connection to the display. */
1.51 markus 2894: return sock;
1.25 markus 2895: }
1.27 markus 2896: /*
2897: * Connect to an inet socket. The DISPLAY value is supposedly
2898: * hostname:d[.s], where hostname may also be numeric IP address.
2899: */
1.145 stevesk 2900: strlcpy(buf, display, sizeof(buf));
1.25 markus 2901: cp = strchr(buf, ':');
2902: if (!cp) {
2903: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2904: return -1;
1.25 markus 2905: }
2906: *cp = 0;
1.27 markus 2907: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2908: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2909: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2910: display);
1.51 markus 2911: return -1;
1.25 markus 2912: }
1.35 markus 2913:
2914: /* Look up the host address */
2915: memset(&hints, 0, sizeof(hints));
2916: hints.ai_family = IPv4or6;
2917: hints.ai_socktype = SOCK_STREAM;
2918: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2919: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2920: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2921: return -1;
1.25 markus 2922: }
1.35 markus 2923: for (ai = aitop; ai; ai = ai->ai_next) {
2924: /* Create a socket. */
1.189 markus 2925: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2926: if (sock < 0) {
1.194 markus 2927: debug2("socket: %.100s", strerror(errno));
1.41 markus 2928: continue;
2929: }
2930: /* Connect it to the display. */
2931: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2932: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2933: 6000 + display_number, strerror(errno));
2934: close(sock);
2935: continue;
2936: }
2937: /* Success */
2938: break;
1.35 markus 2939: }
2940: freeaddrinfo(aitop);
2941: if (!ai) {
1.49 markus 2942: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2943: strerror(errno));
1.51 markus 2944: return -1;
1.25 markus 2945: }
1.162 stevesk 2946: set_nodelay(sock);
1.51 markus 2947: return sock;
2948: }
2949:
2950: /*
2951: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2952: * the remote channel number. We should do whatever we want, and respond
2953: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2954: */
2955:
2956: void
1.154 markus 2957: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2958: {
1.113 markus 2959: Channel *c = NULL;
2960: int remote_id, sock = 0;
1.51 markus 2961: char *remote_host;
1.25 markus 2962:
1.113 markus 2963: debug("Received X11 open request.");
1.51 markus 2964:
1.113 markus 2965: remote_id = packet_get_int();
1.121 markus 2966:
2967: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2968: remote_host = packet_get_string(NULL);
1.51 markus 2969: } else {
2970: remote_host = xstrdup("unknown (remote did not supply name)");
2971: }
1.152 markus 2972: packet_check_eom();
1.25 markus 2973:
1.51 markus 2974: /* Obtain a connection to the real X display. */
2975: sock = x11_connect_display();
1.113 markus 2976: if (sock != -1) {
2977: /* Allocate a channel for this connection. */
2978: c = channel_new("connected x11 socket",
2979: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2980: remote_host, 1);
1.167 markus 2981: c->remote_id = remote_id;
2982: c->force_drain = 1;
1.113 markus 2983: }
1.190 markus 2984: xfree(remote_host);
1.113 markus 2985: if (c == NULL) {
1.51 markus 2986: /* Send refusal to the remote host. */
2987: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2988: packet_put_int(remote_id);
1.51 markus 2989: } else {
2990: /* Send a confirmation to the remote host. */
2991: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2992: packet_put_int(remote_id);
2993: packet_put_int(c->self);
1.51 markus 2994: }
1.113 markus 2995: packet_send();
1.72 markus 2996: }
2997:
2998: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2999: void
1.154 markus 3000: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3001: {
3002: int rchan = packet_get_int();
1.180 deraadt 3003:
1.143 deraadt 3004: switch (type) {
1.72 markus 3005: case SSH_SMSG_AGENT_OPEN:
3006: error("Warning: ssh server tried agent forwarding.");
3007: break;
3008: case SSH_SMSG_X11_OPEN:
3009: error("Warning: ssh server tried X11 forwarding.");
3010: break;
3011: default:
1.154 markus 3012: error("deny_input_open: type %d", type);
1.72 markus 3013: break;
3014: }
1.230 stevesk 3015: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3016: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3017: packet_put_int(rchan);
3018: packet_send();
1.1 deraadt 3019: }
3020:
1.27 markus 3021: /*
3022: * Requests forwarding of X11 connections, generates fake authentication
3023: * data, and enables authentication spoofing.
1.121 markus 3024: * This should be called in the client only.
1.27 markus 3025: */
1.49 markus 3026: void
1.215 djm 3027: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3028: const char *proto, const char *data)
1.1 deraadt 3029: {
1.77 markus 3030: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3031: u_int i, value;
1.25 markus 3032: char *new_data;
3033: int screen_number;
3034: const char *cp;
1.207 avsm 3035: u_int32_t rnd = 0;
1.25 markus 3036:
1.220 markus 3037: if (x11_saved_display == NULL)
3038: x11_saved_display = xstrdup(disp);
3039: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3040: error("x11_request_forwarding_with_spoofing: different "
3041: "$DISPLAY already forwarded");
3042: return;
3043: }
3044:
1.215 djm 3045: cp = disp;
3046: if (disp)
3047: cp = strchr(disp, ':');
1.25 markus 3048: if (cp)
3049: cp = strchr(cp, '.');
3050: if (cp)
3051: screen_number = atoi(cp + 1);
3052: else
3053: screen_number = 0;
3054:
1.219 djm 3055: if (x11_saved_proto == NULL) {
3056: /* Save protocol name. */
3057: x11_saved_proto = xstrdup(proto);
3058: /*
1.221 djm 3059: * Extract real authentication data and generate fake data
1.219 djm 3060: * of the same length.
3061: */
3062: x11_saved_data = xmalloc(data_len);
3063: x11_fake_data = xmalloc(data_len);
3064: for (i = 0; i < data_len; i++) {
3065: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3066: fatal("x11_request_forwarding: bad "
3067: "authentication data: %.100s", data);
3068: if (i % 4 == 0)
3069: rnd = arc4random();
3070: x11_saved_data[i] = value;
3071: x11_fake_data[i] = rnd & 0xff;
3072: rnd >>= 8;
3073: }
3074: x11_saved_data_len = data_len;
3075: x11_fake_data_len = data_len;
1.25 markus 3076: }
3077:
3078: /* Convert the fake data into hex. */
1.219 djm 3079: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3080:
3081: /* Send the request packet. */
1.51 markus 3082: if (compat20) {
3083: channel_request_start(client_session_id, "x11-req", 0);
3084: packet_put_char(0); /* XXX bool single connection */
3085: } else {
3086: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3087: }
3088: packet_put_cstring(proto);
3089: packet_put_cstring(new_data);
1.25 markus 3090: packet_put_int(screen_number);
3091: packet_send();
3092: packet_write_wait();
3093: xfree(new_data);
1.1 deraadt 3094: }
3095:
1.121 markus 3096:
3097: /* -- agent forwarding */
3098:
1.1 deraadt 3099: /* Sends a message to the server to request authentication fd forwarding. */
3100:
1.49 markus 3101: void
1.142 itojun 3102: auth_request_forwarding(void)
1.1 deraadt 3103: {
1.25 markus 3104: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3105: packet_send();
3106: packet_write_wait();
1.1 deraadt 3107: }
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