Annotation of src/usr.bin/ssh/channels.c, Revision 1.204
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"
1.204 ! djm 42: RCSID("$OpenBSD: channels.c,v 1.203 2004/05/26 23:02:39 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.82 markus 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
1.82 markus 49: #include "log.h"
50: #include "misc.h"
1.14 markus 51: #include "channels.h"
52: #include "compat.h"
1.82 markus 53: #include "canohost.h"
1.64 markus 54: #include "key.h"
55: #include "authfd.h"
1.147 stevesk 56: #include "pathnames.h"
1.193 markus 57: #include "bufaux.h"
1.1 deraadt 58:
1.121 markus 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.113 markus 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.113 markus 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.1 deraadt 71: static int channels_alloc = 0;
72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 75: * updated in channel_new.
1.27 markus 76: */
1.84 markus 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.121 markus 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
1.121 markus 106:
107: /* -- X11 forwarding */
108:
109: /* Maximum number of fake X11 displays to try. */
110: #define MAX_DISPLAYS 1000
111:
112: /* Saved X11 authentication protocol name. */
113: static char *x11_saved_proto = NULL;
114:
115: /* Saved X11 authentication data. This is the real data. */
116: static char *x11_saved_data = NULL;
117: static u_int x11_saved_data_len = 0;
118:
119: /*
120: * Fake X11 authentication data. This is what the server will be sending us;
121: * we should replace any occurrences of this by the real data.
122: */
123: static char *x11_fake_data = NULL;
124: static u_int x11_fake_data_len;
125:
126:
127: /* -- agent forwarding */
128:
129: #define NUM_SOCKS 10
130:
1.82 markus 131: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 132: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 133:
1.121 markus 134: /* helper */
1.127 itojun 135: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 136:
1.121 markus 137: /* -- channel core */
1.41 markus 138:
139: Channel *
140: channel_lookup(int id)
141: {
142: Channel *c;
1.113 markus 143:
1.171 markus 144: if (id < 0 || id >= channels_alloc) {
1.188 itojun 145: logit("channel_lookup: %d: bad id", id);
1.41 markus 146: return NULL;
147: }
1.113 markus 148: c = channels[id];
149: if (c == NULL) {
1.188 itojun 150: logit("channel_lookup: %d: bad id: channel free", id);
1.41 markus 151: return NULL;
152: }
153: return c;
1.55 markus 154: }
155:
1.27 markus 156: /*
1.55 markus 157: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 158: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 159: */
1.1 deraadt 160:
1.127 itojun 161: static void
1.71 markus 162: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
163: int extusage, int nonblock)
1.1 deraadt 164: {
1.25 markus 165: /* Update the maximum file descriptor value. */
1.84 markus 166: channel_max_fd = MAX(channel_max_fd, rfd);
167: channel_max_fd = MAX(channel_max_fd, wfd);
168: channel_max_fd = MAX(channel_max_fd, efd);
169:
1.27 markus 170: /* XXX set close-on-exec -markus */
1.55 markus 171:
1.52 markus 172: c->rfd = rfd;
173: c->wfd = wfd;
174: c->sock = (rfd == wfd) ? rfd : -1;
1.204 ! djm 175: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 176: c->efd = efd;
177: c->extended_usage = extusage;
1.71 markus 178:
1.91 markus 179: /* XXX ugly hack: nonblock is only set by the server */
180: if (nonblock && isatty(c->rfd)) {
1.194 markus 181: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 182: c->isatty = 1;
183: if (!isatty(c->wfd)) {
1.94 markus 184: error("channel %d: wfd %d is not a tty?",
1.91 markus 185: c->self, c->wfd);
186: }
187: } else {
188: c->isatty = 0;
189: }
190:
1.71 markus 191: /* enable nonblocking mode */
192: if (nonblock) {
193: if (rfd != -1)
194: set_nonblock(rfd);
195: if (wfd != -1)
196: set_nonblock(wfd);
197: if (efd != -1)
198: set_nonblock(efd);
199: }
1.52 markus 200: }
201:
202: /*
203: * Allocate a new channel object and set its type and socket. This will cause
204: * remote_name to be freed.
205: */
206:
1.113 markus 207: Channel *
1.52 markus 208: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 209: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 210: {
211: int i, found;
212: Channel *c;
1.25 markus 213:
214: /* Do initial allocation if this is the first call. */
215: if (channels_alloc == 0) {
216: channels_alloc = 10;
1.113 markus 217: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 218: for (i = 0; i < channels_alloc; i++)
1.113 markus 219: channels[i] = NULL;
1.25 markus 220: }
221: /* Try to find a free slot where to put the new channel. */
222: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 223: if (channels[i] == NULL) {
1.25 markus 224: /* Found a free slot. */
225: found = i;
226: break;
227: }
228: if (found == -1) {
1.27 markus 229: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 230: found = channels_alloc;
1.179 markus 231: if (channels_alloc > 10000)
232: fatal("channel_new: internal error: channels_alloc %d "
233: "too big.", channels_alloc);
1.195 markus 234: channels = xrealloc(channels,
235: (channels_alloc + 10) * sizeof(Channel *));
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.25 markus 238: for (i = found; i < channels_alloc; i++)
1.113 markus 239: channels[i] = NULL;
1.25 markus 240: }
1.113 markus 241: /* Initialize and return new channel. */
242: c = channels[found] = xmalloc(sizeof(Channel));
1.137 markus 243: memset(c, 0, sizeof(Channel));
1.25 markus 244: buffer_init(&c->input);
245: buffer_init(&c->output);
1.41 markus 246: buffer_init(&c->extended);
1.159 markus 247: c->ostate = CHAN_OUTPUT_OPEN;
248: c->istate = CHAN_INPUT_OPEN;
249: c->flags = 0;
1.71 markus 250: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 251: c->self = found;
252: c->type = type;
1.41 markus 253: c->ctype = ctype;
1.51 markus 254: c->local_window = window;
255: c->local_window_max = window;
256: c->local_consumed = 0;
257: c->local_maxpacket = maxpack;
1.25 markus 258: c->remote_id = -1;
1.190 markus 259: c->remote_name = xstrdup(remote_name);
1.41 markus 260: c->remote_window = 0;
261: c->remote_maxpacket = 0;
1.133 markus 262: c->force_drain = 0;
1.149 markus 263: c->single_connection = 0;
1.131 markus 264: c->detach_user = NULL;
1.165 markus 265: c->confirm = NULL;
1.204 ! djm 266: c->confirm_ctx = NULL;
1.65 markus 267: c->input_filter = NULL;
1.25 markus 268: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 269: return c;
1.1 deraadt 270: }
1.52 markus 271:
1.132 markus 272: static int
273: channel_find_maxfd(void)
274: {
275: int i, max = 0;
276: Channel *c;
277:
278: for (i = 0; i < channels_alloc; i++) {
279: c = channels[i];
280: if (c != NULL) {
281: max = MAX(max, c->rfd);
282: max = MAX(max, c->wfd);
283: max = MAX(max, c->efd);
284: }
285: }
286: return max;
287: }
288:
289: int
290: channel_close_fd(int *fdp)
291: {
292: int ret = 0, fd = *fdp;
293:
294: if (fd != -1) {
295: ret = close(fd);
296: *fdp = -1;
297: if (fd == channel_max_fd)
298: channel_max_fd = channel_find_maxfd();
299: }
300: return ret;
301: }
302:
1.52 markus 303: /* Close all channel fd/socket. */
304:
1.127 itojun 305: static void
1.52 markus 306: channel_close_fds(Channel *c)
307: {
1.204 ! djm 308: debug3("channel %d: close_fds r %d w %d e %d c %d",
! 309: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 310:
1.132 markus 311: channel_close_fd(&c->sock);
1.204 ! djm 312: channel_close_fd(&c->ctl_fd);
1.132 markus 313: channel_close_fd(&c->rfd);
314: channel_close_fd(&c->wfd);
315: channel_close_fd(&c->efd);
1.121 markus 316: }
317:
318: /* Free the channel and close its fd/socket. */
319:
320: void
321: channel_free(Channel *c)
322: {
323: char *s;
324: int i, n;
325:
326: for (n = 0, i = 0; i < channels_alloc; i++)
327: if (channels[i])
328: n++;
1.194 markus 329: debug("channel %d: free: %s, nchannels %d", c->self,
1.121 markus 330: c->remote_name ? c->remote_name : "???", n);
331:
332: s = channel_open_message();
1.194 markus 333: debug3("channel %d: status: %s", c->self, s);
1.121 markus 334: xfree(s);
335:
336: if (c->sock != -1)
337: shutdown(c->sock, SHUT_RDWR);
1.204 ! djm 338: if (c->ctl_fd != -1)
! 339: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 340: channel_close_fds(c);
341: buffer_free(&c->input);
342: buffer_free(&c->output);
343: buffer_free(&c->extended);
344: if (c->remote_name) {
345: xfree(c->remote_name);
346: c->remote_name = NULL;
347: }
348: channels[c->self] = NULL;
349: xfree(c);
350: }
351:
352: void
1.126 markus 353: channel_free_all(void)
1.121 markus 354: {
355: int i;
356:
1.126 markus 357: for (i = 0; i < channels_alloc; i++)
358: if (channels[i] != NULL)
359: channel_free(channels[i]);
1.131 markus 360: }
361:
1.121 markus 362: /*
363: * Closes the sockets/fds of all channels. This is used to close extra file
364: * descriptors after a fork.
365: */
366:
367: void
1.142 itojun 368: channel_close_all(void)
1.121 markus 369: {
370: int i;
371:
372: for (i = 0; i < channels_alloc; i++)
373: if (channels[i] != NULL)
374: channel_close_fds(channels[i]);
375: }
376:
377: /*
1.131 markus 378: * Stop listening to channels.
379: */
380:
381: void
382: channel_stop_listening(void)
383: {
384: int i;
385: Channel *c;
386:
387: for (i = 0; i < channels_alloc; i++) {
388: c = channels[i];
389: if (c != NULL) {
390: switch (c->type) {
391: case SSH_CHANNEL_AUTH_SOCKET:
392: case SSH_CHANNEL_PORT_LISTENER:
393: case SSH_CHANNEL_RPORT_LISTENER:
394: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 395: channel_close_fd(&c->sock);
1.131 markus 396: channel_free(c);
397: break;
398: }
399: }
400: }
401: }
402:
403: /*
1.121 markus 404: * Returns true if no channel has too much buffered data, and false if one or
405: * more channel is overfull.
406: */
407:
408: int
1.142 itojun 409: channel_not_very_much_buffered_data(void)
1.121 markus 410: {
411: u_int i;
412: Channel *c;
413:
414: for (i = 0; i < channels_alloc; i++) {
415: c = channels[i];
416: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 417: #if 0
418: if (!compat20 &&
419: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 420: debug2("channel %d: big input buffer %d",
1.121 markus 421: c->self, buffer_len(&c->input));
422: return 0;
423: }
1.136 markus 424: #endif
1.121 markus 425: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 426: debug2("channel %d: big output buffer %u > %u",
1.136 markus 427: c->self, buffer_len(&c->output),
428: packet_get_maxsize());
1.121 markus 429: return 0;
430: }
431: }
432: }
433: return 1;
434: }
435:
436: /* Returns true if any channel is still open. */
437:
438: int
1.142 itojun 439: channel_still_open(void)
1.121 markus 440: {
441: int i;
442: Channel *c;
443:
444: for (i = 0; i < channels_alloc; i++) {
445: c = channels[i];
446: if (c == NULL)
447: continue;
448: switch (c->type) {
449: case SSH_CHANNEL_X11_LISTENER:
450: case SSH_CHANNEL_PORT_LISTENER:
451: case SSH_CHANNEL_RPORT_LISTENER:
452: case SSH_CHANNEL_CLOSED:
453: case SSH_CHANNEL_AUTH_SOCKET:
454: case SSH_CHANNEL_DYNAMIC:
455: case SSH_CHANNEL_CONNECTING:
456: case SSH_CHANNEL_ZOMBIE:
457: continue;
458: case SSH_CHANNEL_LARVAL:
459: if (!compat20)
460: fatal("cannot happen: SSH_CHANNEL_LARVAL");
461: continue;
462: case SSH_CHANNEL_OPENING:
463: case SSH_CHANNEL_OPEN:
464: case SSH_CHANNEL_X11_OPEN:
465: return 1;
466: case SSH_CHANNEL_INPUT_DRAINING:
467: case SSH_CHANNEL_OUTPUT_DRAINING:
468: if (!compat13)
469: fatal("cannot happen: OUT_DRAIN");
470: return 1;
471: default:
472: fatal("channel_still_open: bad channel type %d", c->type);
473: /* NOTREACHED */
474: }
475: }
476: return 0;
477: }
478:
479: /* Returns the id of an open channel suitable for keepaliving */
480:
481: int
1.142 itojun 482: channel_find_open(void)
1.121 markus 483: {
484: int i;
485: Channel *c;
486:
487: for (i = 0; i < channels_alloc; i++) {
488: c = channels[i];
489: if (c == NULL)
490: continue;
491: switch (c->type) {
492: case SSH_CHANNEL_CLOSED:
493: case SSH_CHANNEL_DYNAMIC:
494: case SSH_CHANNEL_X11_LISTENER:
495: case SSH_CHANNEL_PORT_LISTENER:
496: case SSH_CHANNEL_RPORT_LISTENER:
497: case SSH_CHANNEL_OPENING:
498: case SSH_CHANNEL_CONNECTING:
499: case SSH_CHANNEL_ZOMBIE:
500: continue;
501: case SSH_CHANNEL_LARVAL:
502: case SSH_CHANNEL_AUTH_SOCKET:
503: case SSH_CHANNEL_OPEN:
504: case SSH_CHANNEL_X11_OPEN:
505: return i;
506: case SSH_CHANNEL_INPUT_DRAINING:
507: case SSH_CHANNEL_OUTPUT_DRAINING:
508: if (!compat13)
509: fatal("cannot happen: OUT_DRAIN");
510: return i;
511: default:
512: fatal("channel_find_open: bad channel type %d", c->type);
513: /* NOTREACHED */
514: }
515: }
516: return -1;
517: }
518:
519:
520: /*
521: * Returns a message describing the currently open forwarded connections,
522: * suitable for sending to the client. The message contains crlf pairs for
523: * newlines.
524: */
525:
526: char *
1.142 itojun 527: channel_open_message(void)
1.121 markus 528: {
529: Buffer buffer;
530: Channel *c;
531: char buf[1024], *cp;
532: int i;
533:
534: buffer_init(&buffer);
535: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
536: buffer_append(&buffer, buf, strlen(buf));
537: for (i = 0; i < channels_alloc; i++) {
538: c = channels[i];
539: if (c == NULL)
540: continue;
541: switch (c->type) {
542: case SSH_CHANNEL_X11_LISTENER:
543: case SSH_CHANNEL_PORT_LISTENER:
544: case SSH_CHANNEL_RPORT_LISTENER:
545: case SSH_CHANNEL_CLOSED:
546: case SSH_CHANNEL_AUTH_SOCKET:
547: case SSH_CHANNEL_ZOMBIE:
548: continue;
549: case SSH_CHANNEL_LARVAL:
550: case SSH_CHANNEL_OPENING:
551: case SSH_CHANNEL_CONNECTING:
552: case SSH_CHANNEL_DYNAMIC:
553: case SSH_CHANNEL_OPEN:
554: case SSH_CHANNEL_X11_OPEN:
555: case SSH_CHANNEL_INPUT_DRAINING:
556: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 ! djm 557: snprintf(buf, sizeof buf,
! 558: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 559: c->self, c->remote_name,
560: c->type, c->remote_id,
561: c->istate, buffer_len(&c->input),
562: c->ostate, buffer_len(&c->output),
1.204 ! djm 563: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 564: buffer_append(&buffer, buf, strlen(buf));
565: continue;
566: default:
567: fatal("channel_open_message: bad channel type %d", c->type);
568: /* NOTREACHED */
569: }
570: }
571: buffer_append(&buffer, "\0", 1);
572: cp = xstrdup(buffer_ptr(&buffer));
573: buffer_free(&buffer);
574: return cp;
575: }
576:
577: void
578: channel_send_open(int id)
579: {
580: Channel *c = channel_lookup(id);
1.180 deraadt 581:
1.121 markus 582: if (c == NULL) {
1.188 itojun 583: logit("channel_send_open: %d: bad id", id);
1.121 markus 584: return;
585: }
1.184 markus 586: debug2("channel %d: send open", id);
1.121 markus 587: packet_start(SSH2_MSG_CHANNEL_OPEN);
588: packet_put_cstring(c->ctype);
589: packet_put_int(c->self);
590: packet_put_int(c->local_window);
591: packet_put_int(c->local_maxpacket);
592: packet_send();
593: }
594:
595: void
1.184 markus 596: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 597: {
1.184 markus 598: Channel *c = channel_lookup(id);
1.180 deraadt 599:
1.121 markus 600: if (c == NULL) {
1.188 itojun 601: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 602: return;
603: }
1.204 ! djm 604: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 605: packet_start(SSH2_MSG_CHANNEL_REQUEST);
606: packet_put_int(c->remote_id);
607: packet_put_cstring(service);
608: packet_put_char(wantconfirm);
609: }
610: void
1.204 ! djm 611: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 612: {
613: Channel *c = channel_lookup(id);
1.180 deraadt 614:
1.121 markus 615: if (c == NULL) {
1.188 itojun 616: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 617: return;
618: }
1.165 markus 619: c->confirm = fn;
1.204 ! djm 620: c->confirm_ctx = ctx;
1.121 markus 621: }
622: void
623: channel_register_cleanup(int id, channel_callback_fn *fn)
624: {
625: Channel *c = channel_lookup(id);
1.180 deraadt 626:
1.121 markus 627: if (c == NULL) {
1.188 itojun 628: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 629: return;
630: }
1.131 markus 631: c->detach_user = fn;
1.121 markus 632: }
633: void
634: channel_cancel_cleanup(int id)
635: {
636: Channel *c = channel_lookup(id);
1.180 deraadt 637:
1.121 markus 638: if (c == NULL) {
1.188 itojun 639: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 640: return;
1.52 markus 641: }
1.131 markus 642: c->detach_user = NULL;
1.121 markus 643: }
644: void
645: channel_register_filter(int id, channel_filter_fn *fn)
646: {
647: Channel *c = channel_lookup(id);
1.180 deraadt 648:
1.121 markus 649: if (c == NULL) {
1.188 itojun 650: logit("channel_register_filter: %d: bad id", id);
1.121 markus 651: return;
1.52 markus 652: }
1.121 markus 653: c->input_filter = fn;
1.52 markus 654: }
655:
1.49 markus 656: void
1.121 markus 657: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 658: int extusage, int nonblock, u_int window_max)
1.1 deraadt 659: {
1.121 markus 660: Channel *c = channel_lookup(id);
1.180 deraadt 661:
1.121 markus 662: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
663: fatal("channel_activate for non-larval channel %d.", id);
664: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
665: c->type = SSH_CHANNEL_OPEN;
1.168 markus 666: c->local_window = c->local_window_max = window_max;
1.121 markus 667: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
668: packet_put_int(c->remote_id);
669: packet_put_int(c->local_window);
670: packet_send();
1.1 deraadt 671: }
672:
1.27 markus 673: /*
1.41 markus 674: * 'channel_pre*' are called just before select() to add any bits relevant to
675: * channels in the select bitmasks.
676: */
677: /*
678: * 'channel_post*': perform any appropriate operations for channels which
679: * have events pending.
1.27 markus 680: */
1.41 markus 681: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
682: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
683: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
684:
1.127 itojun 685: static void
1.41 markus 686: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
687: {
688: FD_SET(c->sock, readset);
689: }
690:
1.127 itojun 691: static void
1.75 markus 692: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
693: {
694: debug3("channel %d: waiting for connection", c->self);
695: FD_SET(c->sock, writeset);
696: }
697:
1.127 itojun 698: static void
1.41 markus 699: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
700: {
701: if (buffer_len(&c->input) < packet_get_maxsize())
702: FD_SET(c->sock, readset);
703: if (buffer_len(&c->output) > 0)
704: FD_SET(c->sock, writeset);
705: }
1.1 deraadt 706:
1.127 itojun 707: static void
1.157 markus 708: channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 709: {
1.157 markus 710: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 711:
1.44 markus 712: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 713: limit > 0 &&
714: buffer_len(&c->input) < limit)
1.44 markus 715: FD_SET(c->rfd, readset);
716: if (c->ostate == CHAN_OUTPUT_OPEN ||
717: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
718: if (buffer_len(&c->output) > 0) {
719: FD_SET(c->wfd, writeset);
720: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 721: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.174 markus 722: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
723: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 724: else
725: chan_obuf_empty(c);
1.44 markus 726: }
727: }
728: /** XXX check close conditions, too */
1.157 markus 729: if (compat20 && c->efd != -1) {
1.44 markus 730: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
731: buffer_len(&c->extended) > 0)
732: FD_SET(c->efd, writeset);
1.172 markus 733: else if (!(c->flags & CHAN_EOF_SENT) &&
734: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 735: buffer_len(&c->extended) < c->remote_window)
736: FD_SET(c->efd, readset);
737: }
1.204 ! djm 738: /* XXX: What about efd? races? */
! 739: if (compat20 && c->ctl_fd != -1 &&
! 740: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
! 741: FD_SET(c->ctl_fd, readset);
1.44 markus 742: }
743:
1.127 itojun 744: static void
1.41 markus 745: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
746: {
747: if (buffer_len(&c->input) == 0) {
748: packet_start(SSH_MSG_CHANNEL_CLOSE);
749: packet_put_int(c->remote_id);
750: packet_send();
751: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 752: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 753: }
754: }
755:
1.127 itojun 756: static void
1.41 markus 757: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
758: {
759: if (buffer_len(&c->output) == 0)
1.113 markus 760: chan_mark_dead(c);
1.49 markus 761: else
1.41 markus 762: FD_SET(c->sock, writeset);
763: }
764:
765: /*
766: * This is a special state for X11 authentication spoofing. An opened X11
767: * connection (when authentication spoofing is being done) remains in this
768: * state until the first packet has been completely read. The authentication
769: * data in that packet is then substituted by the real data if it matches the
770: * fake data, and the channel is put into normal mode.
1.51 markus 771: * XXX All this happens at the client side.
1.121 markus 772: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 773: */
1.127 itojun 774: static int
1.121 markus 775: x11_open_helper(Buffer *b)
1.1 deraadt 776: {
1.77 markus 777: u_char *ucp;
778: u_int proto_len, data_len;
1.25 markus 779:
1.41 markus 780: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 781: if (buffer_len(b) < 12)
1.41 markus 782: return 0;
783:
784: /* Parse the lengths of variable-length fields. */
1.155 stevesk 785: ucp = buffer_ptr(b);
1.41 markus 786: if (ucp[0] == 0x42) { /* Byte order MSB first. */
787: proto_len = 256 * ucp[6] + ucp[7];
788: data_len = 256 * ucp[8] + ucp[9];
789: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
790: proto_len = ucp[6] + 256 * ucp[7];
791: data_len = ucp[8] + 256 * ucp[9];
792: } else {
1.194 markus 793: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 794: ucp[0]);
1.41 markus 795: return -1;
796: }
797:
798: /* Check if the whole packet is in buffer. */
1.121 markus 799: if (buffer_len(b) <
1.41 markus 800: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
801: return 0;
802:
803: /* Check if authentication protocol matches. */
804: if (proto_len != strlen(x11_saved_proto) ||
805: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 806: debug2("X11 connection uses different authentication protocol.");
1.41 markus 807: return -1;
808: }
809: /* Check if authentication data matches our fake data. */
810: if (data_len != x11_fake_data_len ||
811: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
812: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 813: debug2("X11 auth data does not match fake data.");
1.41 markus 814: return -1;
815: }
816: /* Check fake data length */
817: if (x11_fake_data_len != x11_saved_data_len) {
818: error("X11 fake_data_len %d != saved_data_len %d",
819: x11_fake_data_len, x11_saved_data_len);
820: return -1;
821: }
822: /*
823: * Received authentication protocol and data match
824: * our fake data. Substitute the fake data with real
825: * data.
826: */
827: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
828: x11_saved_data, x11_saved_data_len);
829: return 1;
830: }
831:
1.127 itojun 832: static void
1.41 markus 833: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
834: {
1.121 markus 835: int ret = x11_open_helper(&c->output);
1.180 deraadt 836:
1.41 markus 837: if (ret == 1) {
838: /* Start normal processing for the channel. */
839: c->type = SSH_CHANNEL_OPEN;
1.47 markus 840: channel_pre_open_13(c, readset, writeset);
1.41 markus 841: } else if (ret == -1) {
842: /*
843: * We have received an X11 connection that has bad
844: * authentication information.
845: */
1.188 itojun 846: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 847: buffer_clear(&c->input);
848: buffer_clear(&c->output);
1.132 markus 849: channel_close_fd(&c->sock);
1.41 markus 850: c->sock = -1;
851: c->type = SSH_CHANNEL_CLOSED;
852: packet_start(SSH_MSG_CHANNEL_CLOSE);
853: packet_put_int(c->remote_id);
854: packet_send();
855: }
856: }
1.25 markus 857:
1.127 itojun 858: static void
1.51 markus 859: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 860: {
1.121 markus 861: int ret = x11_open_helper(&c->output);
1.133 markus 862:
863: /* c->force_drain = 1; */
864:
1.41 markus 865: if (ret == 1) {
866: c->type = SSH_CHANNEL_OPEN;
1.157 markus 867: channel_pre_open(c, readset, writeset);
1.41 markus 868: } else if (ret == -1) {
1.188 itojun 869: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 870: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 871: chan_read_failed(c);
872: buffer_clear(&c->input);
873: chan_ibuf_empty(c);
874: buffer_clear(&c->output);
875: /* for proto v1, the peer will send an IEOF */
876: if (compat20)
877: chan_write_failed(c);
878: else
879: c->type = SSH_CHANNEL_OPEN;
1.194 markus 880: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 881: }
882: }
1.25 markus 883:
1.104 markus 884: /* try to decode a socks4 header */
1.127 itojun 885: static int
1.104 markus 886: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 887: {
1.181 markus 888: char *p, *host;
1.109 markus 889: int len, have, i, found;
1.148 deraadt 890: char username[256];
1.103 markus 891: struct {
892: u_int8_t version;
893: u_int8_t command;
894: u_int16_t dest_port;
1.104 markus 895: struct in_addr dest_addr;
1.103 markus 896: } s4_req, s4_rsp;
897:
1.104 markus 898: debug2("channel %d: decode socks4", c->self);
1.109 markus 899:
900: have = buffer_len(&c->input);
901: len = sizeof(s4_req);
902: if (have < len)
903: return 0;
904: p = buffer_ptr(&c->input);
905: for (found = 0, i = len; i < have; i++) {
906: if (p[i] == '\0') {
907: found = 1;
908: break;
909: }
910: if (i > 1024) {
911: /* the peer is probably sending garbage */
912: debug("channel %d: decode socks4: too long",
913: c->self);
914: return -1;
915: }
916: }
917: if (!found)
918: return 0;
1.103 markus 919: buffer_get(&c->input, (char *)&s4_req.version, 1);
920: buffer_get(&c->input, (char *)&s4_req.command, 1);
921: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 922: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 923: have = buffer_len(&c->input);
1.103 markus 924: p = buffer_ptr(&c->input);
925: len = strlen(p);
1.106 markus 926: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 927: if (len > have)
1.104 markus 928: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 929: c->self, len, have);
930: strlcpy(username, p, sizeof(username));
931: buffer_consume(&c->input, len);
932: buffer_consume(&c->input, 1); /* trailing '\0' */
933:
1.104 markus 934: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 935: strlcpy(c->path, host, sizeof(c->path));
936: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 937:
1.194 markus 938: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 939: c->self, host, c->host_port, s4_req.command);
1.103 markus 940:
1.104 markus 941: if (s4_req.command != 1) {
942: debug("channel %d: cannot handle: socks4 cn %d",
943: c->self, s4_req.command);
944: return -1;
1.103 markus 945: }
1.104 markus 946: s4_rsp.version = 0; /* vn: 0 for reply */
947: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 948: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 949: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 950: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 951: return 1;
952: }
953:
1.193 markus 954: /* try to decode a socks5 header */
955: #define SSH_SOCKS5_AUTHDONE 0x1000
956: #define SSH_SOCKS5_NOAUTH 0x00
957: #define SSH_SOCKS5_IPV4 0x01
958: #define SSH_SOCKS5_DOMAIN 0x03
959: #define SSH_SOCKS5_IPV6 0x04
960: #define SSH_SOCKS5_CONNECT 0x01
961: #define SSH_SOCKS5_SUCCESS 0x00
962:
963: static int
964: channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
965: {
966: struct {
967: u_int8_t version;
968: u_int8_t command;
969: u_int8_t reserved;
970: u_int8_t atyp;
971: } s5_req, s5_rsp;
972: u_int16_t dest_port;
973: u_char *p, dest_addr[255+1];
974: int i, have, found, nmethods, addrlen, af;
975:
976: debug2("channel %d: decode socks5", c->self);
977: p = buffer_ptr(&c->input);
978: if (p[0] != 0x05)
979: return -1;
980: have = buffer_len(&c->input);
981: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
982: /* format: ver | nmethods | methods */
1.198 djm 983: if (have < 2)
1.193 markus 984: return 0;
985: nmethods = p[1];
986: if (have < nmethods + 2)
987: return 0;
988: /* look for method: "NO AUTHENTICATION REQUIRED" */
989: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
990: if (p[i] == SSH_SOCKS5_NOAUTH ) {
991: found = 1;
992: break;
993: }
994: }
995: if (!found) {
996: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
997: c->self);
998: return -1;
999: }
1000: buffer_consume(&c->input, nmethods + 2);
1001: buffer_put_char(&c->output, 0x05); /* version */
1002: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1003: FD_SET(c->sock, writeset);
1004: c->flags |= SSH_SOCKS5_AUTHDONE;
1005: debug2("channel %d: socks5 auth done", c->self);
1006: return 0; /* need more */
1007: }
1008: debug2("channel %d: socks5 post auth", c->self);
1009: if (have < sizeof(s5_req)+1)
1010: return 0; /* need more */
1011: memcpy((char *)&s5_req, p, sizeof(s5_req));
1012: if (s5_req.version != 0x05 ||
1013: s5_req.command != SSH_SOCKS5_CONNECT ||
1014: s5_req.reserved != 0x00) {
1.194 markus 1015: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1016: return -1;
1017: }
1018: switch(s5_req.atyp){
1019: case SSH_SOCKS5_IPV4:
1020: addrlen = 4;
1021: af = AF_INET;
1022: break;
1023: case SSH_SOCKS5_DOMAIN:
1024: addrlen = p[sizeof(s5_req)];
1025: af = -1;
1026: break;
1027: case SSH_SOCKS5_IPV6:
1028: addrlen = 16;
1029: af = AF_INET6;
1030: break;
1031: default:
1.194 markus 1032: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1033: return -1;
1034: }
1035: if (have < 4 + addrlen + 2)
1036: return 0;
1037: buffer_consume(&c->input, sizeof(s5_req));
1038: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1039: buffer_consume(&c->input, 1); /* host string length */
1040: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1041: buffer_get(&c->input, (char *)&dest_port, 2);
1042: dest_addr[addrlen] = '\0';
1043: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1044: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1045: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1046: return -1;
1047: c->host_port = ntohs(dest_port);
1.198 djm 1048:
1.194 markus 1049: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1050: c->self, c->path, c->host_port, s5_req.command);
1051:
1052: s5_rsp.version = 0x05;
1053: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1054: s5_rsp.reserved = 0; /* ignored */
1055: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1056: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1057: dest_port = 0; /* ignored */
1058:
1059: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1060: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1061: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1062: return 1;
1063: }
1064:
1.104 markus 1065: /* dynamic port forwarding */
1.127 itojun 1066: static void
1.104 markus 1067: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
1068: {
1069: u_char *p;
1070: int have, ret;
1.103 markus 1071:
1.104 markus 1072: have = buffer_len(&c->input);
1.137 markus 1073: c->delayed = 0;
1.104 markus 1074: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1075: /* buffer_dump(&c->input); */
1.104 markus 1076: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1077: if (have < 3) {
1.104 markus 1078: /* need more */
1079: FD_SET(c->sock, readset);
1080: return;
1081: }
1082: /* try to guess the protocol */
1083: p = buffer_ptr(&c->input);
1084: switch (p[0]) {
1085: case 0x04:
1086: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1087: break;
1088: case 0x05:
1089: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1090: break;
1091: default:
1092: ret = -1;
1093: break;
1094: }
1095: if (ret < 0) {
1.113 markus 1096: chan_mark_dead(c);
1.104 markus 1097: } else if (ret == 0) {
1098: debug2("channel %d: pre_dynamic: need more", c->self);
1099: /* need more */
1100: FD_SET(c->sock, readset);
1101: } else {
1102: /* switch to the next state */
1103: c->type = SSH_CHANNEL_OPENING;
1104: port_open_helper(c, "direct-tcpip");
1105: }
1.103 markus 1106: }
1107:
1.41 markus 1108: /* This is our fake X11 server socket. */
1.127 itojun 1109: static void
1.41 markus 1110: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1111: {
1.113 markus 1112: Channel *nc;
1.41 markus 1113: struct sockaddr addr;
1.162 stevesk 1114: int newsock;
1.41 markus 1115: socklen_t addrlen;
1.85 markus 1116: char buf[16384], *remote_ipaddr;
1.51 markus 1117: int remote_port;
1.25 markus 1118:
1.41 markus 1119: if (FD_ISSET(c->sock, readset)) {
1120: debug("X11 connection requested.");
1121: addrlen = sizeof(addr);
1122: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1123: if (c->single_connection) {
1.194 markus 1124: debug2("single_connection: closing X11 listener.");
1.149 markus 1125: channel_close_fd(&c->sock);
1126: chan_mark_dead(c);
1127: }
1.41 markus 1128: if (newsock < 0) {
1129: error("accept: %.100s", strerror(errno));
1130: return;
1131: }
1.162 stevesk 1132: set_nodelay(newsock);
1.85 markus 1133: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1134: remote_port = get_peer_port(newsock);
1.41 markus 1135: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1136: remote_ipaddr, remote_port);
1.51 markus 1137:
1.113 markus 1138: nc = channel_new("accepted x11 socket",
1.51 markus 1139: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1140: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1141: if (compat20) {
1142: packet_start(SSH2_MSG_CHANNEL_OPEN);
1143: packet_put_cstring("x11");
1.113 markus 1144: packet_put_int(nc->self);
1.149 markus 1145: packet_put_int(nc->local_window_max);
1146: packet_put_int(nc->local_maxpacket);
1.85 markus 1147: /* originator ipaddr and port */
1148: packet_put_cstring(remote_ipaddr);
1.57 markus 1149: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1150: debug2("ssh2 x11 bug compat mode");
1.57 markus 1151: } else {
1152: packet_put_int(remote_port);
1153: }
1.51 markus 1154: packet_send();
1155: } else {
1156: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1157: packet_put_int(nc->self);
1.121 markus 1158: if (packet_get_protocol_flags() &
1159: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1160: packet_put_cstring(buf);
1.51 markus 1161: packet_send();
1162: }
1.85 markus 1163: xfree(remote_ipaddr);
1.41 markus 1164: }
1165: }
1.25 markus 1166:
1.127 itojun 1167: static void
1.103 markus 1168: port_open_helper(Channel *c, char *rtype)
1169: {
1170: int direct;
1171: char buf[1024];
1172: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1173: u_short remote_port = get_peer_port(c->sock);
1174:
1175: direct = (strcmp(rtype, "direct-tcpip") == 0);
1176:
1177: snprintf(buf, sizeof buf,
1178: "%s: listening port %d for %.100s port %d, "
1179: "connect from %.200s port %d",
1180: rtype, c->listening_port, c->path, c->host_port,
1181: remote_ipaddr, remote_port);
1182:
1183: xfree(c->remote_name);
1184: c->remote_name = xstrdup(buf);
1185:
1186: if (compat20) {
1187: packet_start(SSH2_MSG_CHANNEL_OPEN);
1188: packet_put_cstring(rtype);
1189: packet_put_int(c->self);
1190: packet_put_int(c->local_window_max);
1191: packet_put_int(c->local_maxpacket);
1192: if (direct) {
1193: /* target host, port */
1194: packet_put_cstring(c->path);
1195: packet_put_int(c->host_port);
1196: } else {
1197: /* listen address, port */
1198: packet_put_cstring(c->path);
1199: packet_put_int(c->listening_port);
1200: }
1201: /* originator host and port */
1202: packet_put_cstring(remote_ipaddr);
1203: packet_put_int(remote_port);
1204: packet_send();
1205: } else {
1206: packet_start(SSH_MSG_PORT_OPEN);
1207: packet_put_int(c->self);
1208: packet_put_cstring(c->path);
1209: packet_put_int(c->host_port);
1.121 markus 1210: if (packet_get_protocol_flags() &
1211: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1212: packet_put_cstring(c->remote_name);
1213: packet_send();
1214: }
1215: xfree(remote_ipaddr);
1216: }
1217:
1.41 markus 1218: /*
1219: * This socket is listening for connections to a forwarded TCP/IP port.
1220: */
1.127 itojun 1221: static void
1.41 markus 1222: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1223: {
1.103 markus 1224: Channel *nc;
1.41 markus 1225: struct sockaddr addr;
1.113 markus 1226: int newsock, nextstate;
1.41 markus 1227: socklen_t addrlen;
1.103 markus 1228: char *rtype;
1.73 markus 1229:
1.41 markus 1230: if (FD_ISSET(c->sock, readset)) {
1231: debug("Connection to port %d forwarding "
1232: "to %.100s port %d requested.",
1233: c->listening_port, c->path, c->host_port);
1.103 markus 1234:
1.137 markus 1235: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1236: nextstate = SSH_CHANNEL_OPENING;
1237: rtype = "forwarded-tcpip";
1238: } else {
1239: if (c->host_port == 0) {
1240: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1241: rtype = "dynamic-tcpip";
1.137 markus 1242: } else {
1243: nextstate = SSH_CHANNEL_OPENING;
1244: rtype = "direct-tcpip";
1245: }
1246: }
1.103 markus 1247:
1.41 markus 1248: addrlen = sizeof(addr);
1249: newsock = accept(c->sock, &addr, &addrlen);
1250: if (newsock < 0) {
1251: error("accept: %.100s", strerror(errno));
1252: return;
1253: }
1.169 stevesk 1254: set_nodelay(newsock);
1.190 markus 1255: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1256: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1257: nc->listening_port = c->listening_port;
1258: nc->host_port = c->host_port;
1259: strlcpy(nc->path, c->path, sizeof(nc->path));
1260:
1.137 markus 1261: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1262: /*
1263: * do not call the channel_post handler until
1264: * this flag has been reset by a pre-handler.
1265: * otherwise the FD_ISSET calls might overflow
1266: */
1267: nc->delayed = 1;
1268: } else {
1.103 markus 1269: port_open_helper(nc, rtype);
1.137 markus 1270: }
1.41 markus 1271: }
1272: }
1.25 markus 1273:
1.41 markus 1274: /*
1275: * This is the authentication agent socket listening for connections from
1276: * clients.
1277: */
1.127 itojun 1278: static void
1.41 markus 1279: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1280: {
1.113 markus 1281: Channel *nc;
1282: int newsock;
1.41 markus 1283: struct sockaddr addr;
1284: socklen_t addrlen;
1.25 markus 1285:
1.41 markus 1286: if (FD_ISSET(c->sock, readset)) {
1287: addrlen = sizeof(addr);
1288: newsock = accept(c->sock, &addr, &addrlen);
1289: if (newsock < 0) {
1290: error("accept from auth socket: %.100s", strerror(errno));
1291: return;
1292: }
1.113 markus 1293: nc = channel_new("accepted auth socket",
1.73 markus 1294: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1295: c->local_window_max, c->local_maxpacket,
1.190 markus 1296: 0, "accepted auth socket", 1);
1.73 markus 1297: if (compat20) {
1298: packet_start(SSH2_MSG_CHANNEL_OPEN);
1299: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1300: packet_put_int(nc->self);
1.73 markus 1301: packet_put_int(c->local_window_max);
1302: packet_put_int(c->local_maxpacket);
1303: } else {
1304: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1305: packet_put_int(nc->self);
1.73 markus 1306: }
1.41 markus 1307: packet_send();
1308: }
1309: }
1.25 markus 1310:
1.127 itojun 1311: static void
1.75 markus 1312: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1313: {
1.114 markus 1314: int err = 0;
1.129 stevesk 1315: socklen_t sz = sizeof(err);
1.114 markus 1316:
1.75 markus 1317: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1318: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1319: err = errno;
1320: error("getsockopt SO_ERROR failed");
1321: }
1322: if (err == 0) {
1323: debug("channel %d: connected", c->self);
1324: c->type = SSH_CHANNEL_OPEN;
1325: if (compat20) {
1326: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1327: packet_put_int(c->remote_id);
1328: packet_put_int(c->self);
1329: packet_put_int(c->local_window);
1330: packet_put_int(c->local_maxpacket);
1331: } else {
1332: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1333: packet_put_int(c->remote_id);
1334: packet_put_int(c->self);
1335: }
1.75 markus 1336: } else {
1.114 markus 1337: debug("channel %d: not connected: %s",
1338: c->self, strerror(err));
1339: if (compat20) {
1340: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1341: packet_put_int(c->remote_id);
1342: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1343: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1344: packet_put_cstring(strerror(err));
1345: packet_put_cstring("");
1346: }
1.75 markus 1347: } else {
1.114 markus 1348: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1349: packet_put_int(c->remote_id);
1.75 markus 1350: }
1.114 markus 1351: chan_mark_dead(c);
1.75 markus 1352: }
1.114 markus 1353: packet_send();
1.75 markus 1354: }
1355: }
1356:
1.127 itojun 1357: static int
1.41 markus 1358: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1359: {
1360: char buf[16*1024];
1361: int len;
1.25 markus 1362:
1.118 markus 1363: if (c->rfd != -1 &&
1.41 markus 1364: FD_ISSET(c->rfd, readset)) {
1365: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1366: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1367: return 1;
1.41 markus 1368: if (len <= 0) {
1.194 markus 1369: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1370: c->self, c->rfd, len);
1.104 markus 1371: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1372: debug2("channel %d: not open", c->self);
1.113 markus 1373: chan_mark_dead(c);
1.103 markus 1374: return -1;
1.104 markus 1375: } else if (compat13) {
1.158 markus 1376: buffer_clear(&c->output);
1.41 markus 1377: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1378: debug2("channel %d: input draining.", c->self);
1.25 markus 1379: } else {
1.41 markus 1380: chan_read_failed(c);
1.25 markus 1381: }
1.41 markus 1382: return -1;
1383: }
1.143 deraadt 1384: if (c->input_filter != NULL) {
1.66 markus 1385: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1386: debug2("channel %d: filter stops", c->self);
1.65 markus 1387: chan_read_failed(c);
1388: }
1389: } else {
1390: buffer_append(&c->input, buf, len);
1391: }
1.41 markus 1392: }
1393: return 1;
1394: }
1.127 itojun 1395: static int
1.41 markus 1396: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1397: {
1.95 markus 1398: struct termios tio;
1.134 markus 1399: u_char *data;
1400: u_int dlen;
1.41 markus 1401: int len;
1.25 markus 1402:
1.41 markus 1403: /* Send buffered output data to the socket. */
1.118 markus 1404: if (c->wfd != -1 &&
1.41 markus 1405: FD_ISSET(c->wfd, writeset) &&
1406: buffer_len(&c->output) > 0) {
1.134 markus 1407: data = buffer_ptr(&c->output);
1408: dlen = buffer_len(&c->output);
1409: len = write(c->wfd, data, dlen);
1.53 markus 1410: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1411: return 1;
1.41 markus 1412: if (len <= 0) {
1.104 markus 1413: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1414: debug2("channel %d: not open", c->self);
1.113 markus 1415: chan_mark_dead(c);
1.104 markus 1416: return -1;
1417: } else if (compat13) {
1.158 markus 1418: buffer_clear(&c->output);
1.194 markus 1419: debug2("channel %d: input draining.", c->self);
1.41 markus 1420: c->type = SSH_CHANNEL_INPUT_DRAINING;
1421: } else {
1422: chan_write_failed(c);
1423: }
1424: return -1;
1.91 markus 1425: }
1.134 markus 1426: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.91 markus 1427: if (tcgetattr(c->wfd, &tio) == 0 &&
1428: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1429: /*
1430: * Simulate echo to reduce the impact of
1.96 markus 1431: * traffic analysis. We need to match the
1.95 markus 1432: * size of a SSH2_MSG_CHANNEL_DATA message
1433: * (4 byte channel id + data)
1.91 markus 1434: */
1.95 markus 1435: packet_send_ignore(4 + len);
1.91 markus 1436: packet_send();
1437: }
1.25 markus 1438: }
1.41 markus 1439: buffer_consume(&c->output, len);
1.44 markus 1440: if (compat20 && len > 0) {
1441: c->local_consumed += len;
1442: }
1443: }
1444: return 1;
1445: }
1.127 itojun 1446: static int
1.44 markus 1447: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1448: {
1449: char buf[16*1024];
1450: int len;
1451:
1.45 markus 1452: /** XXX handle drain efd, too */
1.44 markus 1453: if (c->efd != -1) {
1454: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1455: FD_ISSET(c->efd, writeset) &&
1456: buffer_len(&c->extended) > 0) {
1457: len = write(c->efd, buffer_ptr(&c->extended),
1458: buffer_len(&c->extended));
1.70 markus 1459: debug2("channel %d: written %d to efd %d",
1.44 markus 1460: c->self, len, c->efd);
1.93 markus 1461: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1462: return 1;
1463: if (len <= 0) {
1464: debug2("channel %d: closing write-efd %d",
1465: c->self, c->efd);
1.132 markus 1466: channel_close_fd(&c->efd);
1.93 markus 1467: } else {
1.44 markus 1468: buffer_consume(&c->extended, len);
1469: c->local_consumed += len;
1470: }
1471: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1472: FD_ISSET(c->efd, readset)) {
1473: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1474: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1475: c->self, len, c->efd);
1.93 markus 1476: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1477: return 1;
1478: if (len <= 0) {
1479: debug2("channel %d: closing read-efd %d",
1.45 markus 1480: c->self, c->efd);
1.132 markus 1481: channel_close_fd(&c->efd);
1.93 markus 1482: } else {
1.44 markus 1483: buffer_append(&c->extended, buf, len);
1.93 markus 1484: }
1.44 markus 1485: }
1486: }
1487: return 1;
1488: }
1.127 itojun 1489: static int
1.204 ! djm 1490: channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
! 1491: {
! 1492: char buf[16];
! 1493: int len;
! 1494:
! 1495: /* Monitor control fd to detect if the slave client exits */
! 1496: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
! 1497: len = read(c->ctl_fd, buf, sizeof(buf));
! 1498: if (len < 0 && (errno == EINTR || errno == EAGAIN))
! 1499: return 1;
! 1500: if (len <= 0) {
! 1501: debug2("channel %d: ctl read<=0", c->self);
! 1502: if (c->type != SSH_CHANNEL_OPEN) {
! 1503: debug2("channel %d: not open", c->self);
! 1504: chan_mark_dead(c);
! 1505: return -1;
! 1506: } else {
! 1507: chan_read_failed(c);
! 1508: chan_write_failed(c);
! 1509: }
! 1510: return -1;
! 1511: } else
! 1512: fatal("%s: unexpected data on ctl fd", __func__);
! 1513: }
! 1514: return 1;
! 1515: }
! 1516: static int
1.93 markus 1517: channel_check_window(Channel *c)
1.44 markus 1518: {
1.104 markus 1519: if (c->type == SSH_CHANNEL_OPEN &&
1520: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1521: c->local_window < c->local_window_max/2 &&
1522: c->local_consumed > 0) {
1523: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1524: packet_put_int(c->remote_id);
1525: packet_put_int(c->local_consumed);
1526: packet_send();
1.70 markus 1527: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1528: c->self, c->local_window,
1529: c->local_consumed);
1530: c->local_window += c->local_consumed;
1531: c->local_consumed = 0;
1.1 deraadt 1532: }
1.41 markus 1533: return 1;
1.1 deraadt 1534: }
1535:
1.127 itojun 1536: static void
1.157 markus 1537: channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 1538: {
1.137 markus 1539: if (c->delayed)
1540: return;
1.41 markus 1541: channel_handle_rfd(c, readset, writeset);
1542: channel_handle_wfd(c, readset, writeset);
1.157 markus 1543: if (!compat20)
1.137 markus 1544: return;
1.44 markus 1545: channel_handle_efd(c, readset, writeset);
1.204 ! djm 1546: channel_handle_ctl(c, readset, writeset);
1.93 markus 1547: channel_check_window(c);
1.44 markus 1548: }
1549:
1.127 itojun 1550: static void
1.41 markus 1551: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1552: {
1.41 markus 1553: int len;
1.180 deraadt 1554:
1.41 markus 1555: /* Send buffered output data to the socket. */
1556: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1557: len = write(c->sock, buffer_ptr(&c->output),
1558: buffer_len(&c->output));
1559: if (len <= 0)
1.158 markus 1560: buffer_clear(&c->output);
1.41 markus 1561: else
1562: buffer_consume(&c->output, len);
1563: }
1564: }
1.25 markus 1565:
1.127 itojun 1566: static void
1.44 markus 1567: channel_handler_init_20(void)
1568: {
1.157 markus 1569: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1570: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1571: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1572: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1573: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1574: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1575: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1576: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1577:
1.157 markus 1578: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1579: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1580: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1581: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1582: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1583: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1584: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1585: }
1586:
1.127 itojun 1587: static void
1.41 markus 1588: channel_handler_init_13(void)
1589: {
1590: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1591: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1592: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1593: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1594: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1595: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1596: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1597: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1598: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1599:
1.157 markus 1600: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1601: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1602: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1603: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1604: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1605: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1606: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1607: }
1.25 markus 1608:
1.127 itojun 1609: static void
1.41 markus 1610: channel_handler_init_15(void)
1611: {
1.157 markus 1612: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1613: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1614: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1615: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1616: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1617: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1618: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1619:
1.41 markus 1620: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1621: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1622: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1623: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1624: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1625: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1626: }
1.27 markus 1627:
1.127 itojun 1628: static void
1.41 markus 1629: channel_handler_init(void)
1630: {
1631: int i;
1.180 deraadt 1632:
1.148 deraadt 1633: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1634: channel_pre[i] = NULL;
1635: channel_post[i] = NULL;
1636: }
1.44 markus 1637: if (compat20)
1638: channel_handler_init_20();
1639: else if (compat13)
1.41 markus 1640: channel_handler_init_13();
1641: else
1642: channel_handler_init_15();
1643: }
1.25 markus 1644:
1.140 markus 1645: /* gc dead channels */
1646: static void
1647: channel_garbage_collect(Channel *c)
1648: {
1649: if (c == NULL)
1650: return;
1651: if (c->detach_user != NULL) {
1652: if (!chan_is_dead(c, 0))
1653: return;
1.194 markus 1654: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1655: c->detach_user(c->self, NULL);
1656: /* if we still have a callback */
1657: if (c->detach_user != NULL)
1658: return;
1.194 markus 1659: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1660: }
1661: if (!chan_is_dead(c, 1))
1662: return;
1.194 markus 1663: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1664: channel_free(c);
1665: }
1666:
1.127 itojun 1667: static void
1.41 markus 1668: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1669: {
1670: static int did_init = 0;
1671: int i;
1672: Channel *c;
1.25 markus 1673:
1.41 markus 1674: if (!did_init) {
1675: channel_handler_init();
1676: did_init = 1;
1677: }
1678: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1679: c = channels[i];
1680: if (c == NULL)
1.41 markus 1681: continue;
1.118 markus 1682: if (ftab[c->type] != NULL)
1683: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1684: channel_garbage_collect(c);
1.1 deraadt 1685: }
1686: }
1687:
1.121 markus 1688: /*
1689: * Allocate/update select bitmasks and add any bits relevant to channels in
1690: * select bitmasks.
1691: */
1.49 markus 1692: void
1.100 markus 1693: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.132 markus 1694: int *nallocp, int rekeying)
1.41 markus 1695: {
1.84 markus 1696: int n;
1697: u_int sz;
1698:
1699: n = MAX(*maxfdp, channel_max_fd);
1700:
1701: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.132 markus 1702: /* perhaps check sz < nalloc/2 and shrink? */
1703: if (*readsetp == NULL || sz > *nallocp) {
1704: *readsetp = xrealloc(*readsetp, sz);
1705: *writesetp = xrealloc(*writesetp, sz);
1706: *nallocp = sz;
1.84 markus 1707: }
1.132 markus 1708: *maxfdp = n;
1.84 markus 1709: memset(*readsetp, 0, sz);
1710: memset(*writesetp, 0, sz);
1711:
1.100 markus 1712: if (!rekeying)
1713: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1714: }
1715:
1.121 markus 1716: /*
1717: * After select, perform any appropriate operations for channels which have
1718: * events pending.
1719: */
1.49 markus 1720: void
1.41 markus 1721: channel_after_select(fd_set * readset, fd_set * writeset)
1722: {
1723: channel_handler(channel_post, readset, writeset);
1724: }
1725:
1.121 markus 1726:
1.84 markus 1727: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1728:
1.49 markus 1729: void
1.142 itojun 1730: channel_output_poll(void)
1.1 deraadt 1731: {
1.41 markus 1732: Channel *c;
1.178 markus 1733: int i;
1734: u_int len;
1.1 deraadt 1735:
1.25 markus 1736: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1737: c = channels[i];
1738: if (c == NULL)
1739: continue;
1.37 markus 1740:
1.121 markus 1741: /*
1742: * We are only interested in channels that can have buffered
1743: * incoming data.
1744: */
1.37 markus 1745: if (compat13) {
1.41 markus 1746: if (c->type != SSH_CHANNEL_OPEN &&
1747: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1748: continue;
1749: } else {
1.41 markus 1750: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1751: continue;
1752: }
1.46 markus 1753: if (compat20 &&
1754: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1755: /* XXX is this true? */
1.140 markus 1756: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1757: continue;
1758: }
1.25 markus 1759:
1760: /* Get the amount of buffered data for this channel. */
1.93 markus 1761: if ((c->istate == CHAN_INPUT_OPEN ||
1762: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1763: (len = buffer_len(&c->input)) > 0) {
1.121 markus 1764: /*
1765: * Send some data for the other side over the secure
1766: * connection.
1767: */
1.44 markus 1768: if (compat20) {
1769: if (len > c->remote_window)
1770: len = c->remote_window;
1771: if (len > c->remote_maxpacket)
1772: len = c->remote_maxpacket;
1.25 markus 1773: } else {
1.44 markus 1774: if (packet_is_interactive()) {
1775: if (len > 1024)
1776: len = 512;
1777: } else {
1778: /* Keep the packets at reasonable size. */
1779: if (len > packet_get_maxsize()/2)
1780: len = packet_get_maxsize()/2;
1781: }
1.25 markus 1782: }
1.41 markus 1783: if (len > 0) {
1.44 markus 1784: packet_start(compat20 ?
1785: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1786: packet_put_int(c->remote_id);
1787: packet_put_string(buffer_ptr(&c->input), len);
1788: packet_send();
1789: buffer_consume(&c->input, len);
1790: c->remote_window -= len;
1791: }
1792: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1793: if (compat13)
1794: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1795: /*
1796: * input-buffer is empty and read-socket shutdown:
1.172 markus 1797: * tell peer, that we will not send more data: send IEOF.
1798: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1799: */
1.172 markus 1800: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.174 markus 1801: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1802: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1803: else
1804: chan_ibuf_empty(c);
1.25 markus 1805: }
1.44 markus 1806: /* Send extended data, i.e. stderr */
1807: if (compat20 &&
1.172 markus 1808: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1809: c->remote_window > 0 &&
1810: (len = buffer_len(&c->extended)) > 0 &&
1811: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1812: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1813: c->self, c->remote_window, buffer_len(&c->extended),
1814: c->extended_usage);
1.44 markus 1815: if (len > c->remote_window)
1816: len = c->remote_window;
1817: if (len > c->remote_maxpacket)
1818: len = c->remote_maxpacket;
1819: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1820: packet_put_int(c->remote_id);
1821: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1822: packet_put_string(buffer_ptr(&c->extended), len);
1823: packet_send();
1824: buffer_consume(&c->extended, len);
1825: c->remote_window -= len;
1.93 markus 1826: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1827: }
1.25 markus 1828: }
1.1 deraadt 1829: }
1830:
1.121 markus 1831:
1832: /* -- protocol input */
1.1 deraadt 1833:
1.49 markus 1834: void
1.154 markus 1835: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1836: {
1.37 markus 1837: int id;
1.25 markus 1838: char *data;
1.77 markus 1839: u_int data_len;
1.41 markus 1840: Channel *c;
1.25 markus 1841:
1842: /* Get the channel number and verify it. */
1.37 markus 1843: id = packet_get_int();
1.41 markus 1844: c = channel_lookup(id);
1845: if (c == NULL)
1.37 markus 1846: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1847:
1848: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1849: if (c->type != SSH_CHANNEL_OPEN &&
1850: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1851: return;
1852:
1.25 markus 1853: /* Get the data. */
1854: data = packet_get_string(&data_len);
1.200 markus 1855:
1856: /*
1857: * Ignore data for protocol > 1.3 if output end is no longer open.
1858: * For protocol 2 the sending side is reducing its window as it sends
1859: * data, so we must 'fake' consumption of the data in order to ensure
1860: * that window updates are sent back. Otherwise the connection might
1861: * deadlock.
1862: */
1863: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1864: if (compat20) {
1865: c->local_window -= data_len;
1866: c->local_consumed += data_len;
1867: }
1868: xfree(data);
1869: return;
1870: }
1.41 markus 1871:
1.143 deraadt 1872: if (compat20) {
1.44 markus 1873: if (data_len > c->local_maxpacket) {
1.188 itojun 1874: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1875: c->self, data_len, c->local_maxpacket);
1876: }
1877: if (data_len > c->local_window) {
1.188 itojun 1878: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1879: c->self, data_len, c->local_window);
1880: xfree(data);
1881: return;
1882: }
1883: c->local_window -= data_len;
1884: }
1.152 markus 1885: packet_check_eom();
1.41 markus 1886: buffer_append(&c->output, data, data_len);
1.25 markus 1887: xfree(data);
1.1 deraadt 1888: }
1.121 markus 1889:
1.49 markus 1890: void
1.154 markus 1891: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 1892: {
1893: int id;
1894: char *data;
1.177 markus 1895: u_int data_len, tcode;
1.44 markus 1896: Channel *c;
1897:
1898: /* Get the channel number and verify it. */
1899: id = packet_get_int();
1900: c = channel_lookup(id);
1901:
1902: if (c == NULL)
1903: packet_disconnect("Received extended_data for bad channel %d.", id);
1904: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 1905: logit("channel %d: ext data for non open", id);
1.44 markus 1906: return;
1.172 markus 1907: }
1908: if (c->flags & CHAN_EOF_RCVD) {
1909: if (datafellows & SSH_BUG_EXTEOF)
1910: debug("channel %d: accepting ext data after eof", id);
1911: else
1912: packet_disconnect("Received extended_data after EOF "
1913: "on channel %d.", id);
1.44 markus 1914: }
1915: tcode = packet_get_int();
1916: if (c->efd == -1 ||
1917: c->extended_usage != CHAN_EXTENDED_WRITE ||
1918: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 1919: logit("channel %d: bad ext data", c->self);
1.44 markus 1920: return;
1921: }
1922: data = packet_get_string(&data_len);
1.152 markus 1923: packet_check_eom();
1.44 markus 1924: if (data_len > c->local_window) {
1.188 itojun 1925: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 1926: c->self, data_len, c->local_window);
1927: xfree(data);
1928: return;
1929: }
1.70 markus 1930: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1931: c->local_window -= data_len;
1932: buffer_append(&c->extended, data, data_len);
1933: xfree(data);
1934: }
1935:
1.49 markus 1936: void
1.154 markus 1937: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 1938: {
1939: int id;
1940: Channel *c;
1941:
1942: id = packet_get_int();
1.152 markus 1943: packet_check_eom();
1.41 markus 1944: c = channel_lookup(id);
1945: if (c == NULL)
1946: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1947: chan_rcvd_ieof(c);
1.133 markus 1948:
1949: /* XXX force input close */
1.156 markus 1950: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 1951: debug("channel %d: FORCE input drain", c->self);
1952: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 1953: if (buffer_len(&c->input) == 0)
1954: chan_ibuf_empty(c);
1.133 markus 1955: }
1956:
1.41 markus 1957: }
1.1 deraadt 1958:
1.49 markus 1959: void
1.154 markus 1960: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1961: {
1.41 markus 1962: int id;
1963: Channel *c;
1.1 deraadt 1964:
1.41 markus 1965: id = packet_get_int();
1.152 markus 1966: packet_check_eom();
1.41 markus 1967: c = channel_lookup(id);
1968: if (c == NULL)
1969: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1970:
1971: /*
1972: * Send a confirmation that we have closed the channel and no more
1973: * data is coming for it.
1974: */
1.25 markus 1975: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1976: packet_put_int(c->remote_id);
1.25 markus 1977: packet_send();
1978:
1.27 markus 1979: /*
1980: * If the channel is in closed state, we have sent a close request,
1981: * and the other side will eventually respond with a confirmation.
1982: * Thus, we cannot free the channel here, because then there would be
1983: * no-one to receive the confirmation. The channel gets freed when
1984: * the confirmation arrives.
1985: */
1.41 markus 1986: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1987: /*
1988: * Not a closed channel - mark it as draining, which will
1989: * cause it to be freed later.
1990: */
1.158 markus 1991: buffer_clear(&c->input);
1.41 markus 1992: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1993: }
1.1 deraadt 1994: }
1995:
1.41 markus 1996: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1997: void
1.154 markus 1998: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 1999: {
2000: int id = packet_get_int();
2001: Channel *c = channel_lookup(id);
1.151 markus 2002:
1.152 markus 2003: packet_check_eom();
1.41 markus 2004: if (c == NULL)
2005: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2006: chan_rcvd_oclose(c);
2007: }
1.1 deraadt 2008:
1.49 markus 2009: void
1.154 markus 2010: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2011: {
1.41 markus 2012: int id = packet_get_int();
2013: Channel *c = channel_lookup(id);
1.1 deraadt 2014:
1.152 markus 2015: packet_check_eom();
1.41 markus 2016: if (c == NULL)
2017: packet_disconnect("Received close confirmation for "
2018: "out-of-range channel %d.", id);
2019: if (c->type != SSH_CHANNEL_CLOSED)
2020: packet_disconnect("Received close confirmation for "
2021: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2022: channel_free(c);
1.1 deraadt 2023: }
2024:
1.49 markus 2025: void
1.154 markus 2026: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2027: {
1.41 markus 2028: int id, remote_id;
2029: Channel *c;
1.1 deraadt 2030:
1.41 markus 2031: id = packet_get_int();
2032: c = channel_lookup(id);
1.25 markus 2033:
1.41 markus 2034: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2035: packet_disconnect("Received open confirmation for "
2036: "non-opening channel %d.", id);
2037: remote_id = packet_get_int();
1.27 markus 2038: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2039: c->remote_id = remote_id;
2040: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2041:
2042: if (compat20) {
2043: c->remote_window = packet_get_int();
2044: c->remote_maxpacket = packet_get_int();
1.165 markus 2045: if (c->confirm) {
1.70 markus 2046: debug2("callback start");
1.204 ! djm 2047: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2048: debug2("callback done");
1.44 markus 2049: }
1.194 markus 2050: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2051: c->remote_window, c->remote_maxpacket);
2052: }
1.152 markus 2053: packet_check_eom();
1.1 deraadt 2054: }
2055:
1.127 itojun 2056: static char *
1.114 markus 2057: reason2txt(int reason)
2058: {
1.143 deraadt 2059: switch (reason) {
1.114 markus 2060: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2061: return "administratively prohibited";
2062: case SSH2_OPEN_CONNECT_FAILED:
2063: return "connect failed";
2064: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2065: return "unknown channel type";
2066: case SSH2_OPEN_RESOURCE_SHORTAGE:
2067: return "resource shortage";
2068: }
1.117 stevesk 2069: return "unknown reason";
1.114 markus 2070: }
2071:
1.49 markus 2072: void
1.154 markus 2073: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2074: {
1.86 markus 2075: int id, reason;
2076: char *msg = NULL, *lang = NULL;
1.41 markus 2077: Channel *c;
2078:
2079: id = packet_get_int();
2080: c = channel_lookup(id);
1.25 markus 2081:
1.41 markus 2082: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2083: packet_disconnect("Received open failure for "
2084: "non-opening channel %d.", id);
1.44 markus 2085: if (compat20) {
1.86 markus 2086: reason = packet_get_int();
1.110 markus 2087: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2088: msg = packet_get_string(NULL);
2089: lang = packet_get_string(NULL);
2090: }
1.188 itojun 2091: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2092: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2093: if (msg != NULL)
2094: xfree(msg);
2095: if (lang != NULL)
2096: xfree(lang);
1.44 markus 2097: }
1.152 markus 2098: packet_check_eom();
1.25 markus 2099: /* Free the channel. This will also close the socket. */
1.113 markus 2100: channel_free(c);
1.44 markus 2101: }
2102:
1.121 markus 2103: void
1.154 markus 2104: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2105: {
2106: Channel *c;
1.178 markus 2107: int id;
2108: u_int adjust;
1.121 markus 2109:
2110: if (!compat20)
2111: return;
2112:
2113: /* Get the channel number and verify it. */
2114: id = packet_get_int();
2115: c = channel_lookup(id);
1.1 deraadt 2116:
1.121 markus 2117: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2118: logit("Received window adjust for "
1.121 markus 2119: "non-open channel %d.", id);
2120: return;
2121: }
2122: adjust = packet_get_int();
1.152 markus 2123: packet_check_eom();
1.178 markus 2124: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2125: c->remote_window += adjust;
2126: }
1.1 deraadt 2127:
1.121 markus 2128: void
1.154 markus 2129: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2130: {
1.121 markus 2131: Channel *c = NULL;
2132: u_short host_port;
2133: char *host, *originator_string;
2134: int remote_id, sock = -1;
2135:
2136: remote_id = packet_get_int();
2137: host = packet_get_string(NULL);
2138: host_port = packet_get_int();
1.25 markus 2139:
1.121 markus 2140: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2141: originator_string = packet_get_string(NULL);
2142: } else {
2143: originator_string = xstrdup("unknown (remote did not supply name)");
2144: }
1.152 markus 2145: packet_check_eom();
1.121 markus 2146: sock = channel_connect_to(host, host_port);
2147: if (sock != -1) {
2148: c = channel_new("connected socket",
2149: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2150: originator_string, 1);
1.167 markus 2151: c->remote_id = remote_id;
1.25 markus 2152: }
1.190 markus 2153: xfree(originator_string);
1.121 markus 2154: if (c == NULL) {
2155: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2156: packet_put_int(remote_id);
2157: packet_send();
2158: }
2159: xfree(host);
1.1 deraadt 2160: }
2161:
1.121 markus 2162:
2163: /* -- tcp forwarding */
1.135 markus 2164:
2165: void
2166: channel_set_af(int af)
2167: {
2168: IPv4or6 = af;
2169: }
1.121 markus 2170:
1.160 markus 2171: static int
2172: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2173: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2174: {
1.113 markus 2175: Channel *c;
1.160 markus 2176: int success, sock, on = 1;
1.35 markus 2177: struct addrinfo hints, *ai, *aitop;
1.160 markus 2178: const char *host;
1.35 markus 2179: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2180:
1.87 markus 2181: success = 0;
1.160 markus 2182: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2183: listen_addr : host_to_connect;
1.87 markus 2184:
1.160 markus 2185: if (host == NULL) {
2186: error("No forward host name.");
2187: return success;
1.73 markus 2188: }
1.113 markus 2189: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2190: error("Forward host name too long.");
2191: return success;
2192: }
1.25 markus 2193:
1.28 markus 2194: /*
1.35 markus 2195: * getaddrinfo returns a loopback address if the hostname is
2196: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2197: */
1.35 markus 2198: memset(&hints, 0, sizeof(hints));
2199: hints.ai_family = IPv4or6;
2200: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2201: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2202: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2203: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2204: packet_disconnect("getaddrinfo: fatal error");
2205:
2206: for (ai = aitop; ai; ai = ai->ai_next) {
2207: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2208: continue;
2209: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2210: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2211: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2212: continue;
2213: }
2214: /* Create a port to listen for the host. */
1.189 markus 2215: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2216: if (sock < 0) {
2217: /* this is no error since kernel may not support ipv6 */
2218: verbose("socket: %.100s", strerror(errno));
2219: continue;
2220: }
2221: /*
1.182 stevesk 2222: * Set socket options.
2223: * Allow local port reuse in TIME_WAIT.
1.35 markus 2224: */
1.182 stevesk 2225: if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on,
2226: sizeof(on)) == -1)
2227: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
2228:
1.35 markus 2229: debug("Local forwarding listening on %s port %s.", ntop, strport);
2230:
2231: /* Bind the socket to the address. */
2232: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2233: /* address can be in use ipv6 address is already bound */
2234: verbose("bind: %.100s", strerror(errno));
2235: close(sock);
2236: continue;
2237: }
2238: /* Start listening for connections on the socket. */
1.199 markus 2239: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2240: error("listen: %.100s", strerror(errno));
2241: close(sock);
2242: continue;
2243: }
2244: /* Allocate a channel number for the socket. */
1.121 markus 2245: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2246: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2247: 0, "port listener", 1);
1.113 markus 2248: strlcpy(c->path, host, sizeof(c->path));
2249: c->host_port = port_to_connect;
2250: c->listening_port = listen_port;
1.35 markus 2251: success = 1;
2252: }
2253: if (success == 0)
1.160 markus 2254: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2255: listen_port);
1.35 markus 2256: freeaddrinfo(aitop);
1.87 markus 2257: return success;
1.25 markus 2258: }
1.1 deraadt 2259:
1.202 djm 2260: int
2261: channel_cancel_rport_listener(const char *host, u_short port)
2262: {
2263: int i, found = 0;
2264:
2265: for(i = 0; i < channels_alloc; i++) {
2266: Channel *c = channels[i];
2267:
2268: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2269: strncmp(c->path, host, sizeof(c->path)) == 0 &&
2270: c->listening_port == port) {
2271: debug2("%s: close clannel %d", __func__, i);
2272: channel_free(c);
2273: found = 1;
2274: }
2275: }
2276:
2277: return (found);
2278: }
2279:
1.160 markus 2280: /* protocol local port fwd, used by ssh (and sshd in v1) */
2281: int
2282: channel_setup_local_fwd_listener(u_short listen_port,
2283: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2284: {
2285: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2286: NULL, listen_port, host_to_connect, port_to_connect, gateway_ports);
2287: }
2288:
2289: /* protocol v2 remote port fwd, used by sshd */
2290: int
2291: channel_setup_remote_fwd_listener(const char *listen_address,
2292: u_short listen_port, int gateway_ports)
2293: {
2294: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2295: listen_address, listen_port, NULL, 0, gateway_ports);
2296: }
2297:
1.27 markus 2298: /*
2299: * Initiate forwarding of connections to port "port" on remote host through
2300: * the secure channel to host:port from local side.
2301: */
1.1 deraadt 2302:
1.49 markus 2303: void
1.73 markus 2304: channel_request_remote_forwarding(u_short listen_port,
2305: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2306: {
1.153 markus 2307: int type, success = 0;
1.73 markus 2308:
1.25 markus 2309: /* Record locally that connection to this host/port is permitted. */
2310: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2311: fatal("channel_request_remote_forwarding: too many forwards");
2312:
2313: /* Send the forward request to the remote side. */
1.44 markus 2314: if (compat20) {
2315: const char *address_to_bind = "0.0.0.0";
2316: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2317: packet_put_cstring("tcpip-forward");
1.173 markus 2318: packet_put_char(1); /* boolean: want reply */
1.44 markus 2319: packet_put_cstring(address_to_bind);
2320: packet_put_int(listen_port);
1.73 markus 2321: packet_send();
2322: packet_write_wait();
2323: /* Assume that server accepts the request */
2324: success = 1;
1.44 markus 2325: } else {
2326: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2327: packet_put_int(listen_port);
2328: packet_put_cstring(host_to_connect);
1.44 markus 2329: packet_put_int(port_to_connect);
2330: packet_send();
2331: packet_write_wait();
1.73 markus 2332:
2333: /* Wait for response from the remote side. */
1.153 markus 2334: type = packet_read();
1.73 markus 2335: switch (type) {
2336: case SSH_SMSG_SUCCESS:
2337: success = 1;
2338: break;
2339: case SSH_SMSG_FAILURE:
1.188 itojun 2340: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2341: break;
2342: default:
2343: /* Unknown packet */
2344: packet_disconnect("Protocol error for port forward request:"
2345: "received packet type %d.", type);
2346: }
2347: }
2348: if (success) {
2349: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2350: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2351: permitted_opens[num_permitted_opens].listen_port = listen_port;
2352: num_permitted_opens++;
1.44 markus 2353: }
1.1 deraadt 2354: }
2355:
1.27 markus 2356: /*
1.202 djm 2357: * Request cancellation of remote forwarding of connection host:port from
2358: * local side.
2359: */
2360:
2361: void
2362: channel_request_rforward_cancel(u_short port)
2363: {
2364: int i;
2365: const char *address_to_bind = "0.0.0.0";
2366:
2367: if (!compat20)
2368: return;
2369:
2370: for (i = 0; i < num_permitted_opens; i++) {
2371: if (permitted_opens[i].host_to_connect != NULL &&
2372: permitted_opens[i].listen_port == port)
2373: break;
2374: }
2375: if (i >= num_permitted_opens) {
2376: debug("%s: requested forward not found", __func__);
2377: return;
2378: }
2379: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2380: packet_put_cstring("cancel-tcpip-forward");
2381: packet_put_char(0);
2382: packet_put_cstring(address_to_bind);
2383: packet_put_int(port);
2384: packet_send();
2385:
2386: permitted_opens[i].listen_port = 0;
2387: permitted_opens[i].port_to_connect = 0;
2388: free(permitted_opens[i].host_to_connect);
2389: permitted_opens[i].host_to_connect = NULL;
2390: }
2391:
2392: /*
1.27 markus 2393: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2394: * listening for the port, and sends back a success reply (or disconnect
2395: * message if there was an error). This never returns if there was an error.
2396: */
1.1 deraadt 2397:
1.49 markus 2398: void
1.56 markus 2399: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2400: {
1.31 markus 2401: u_short port, host_port;
1.25 markus 2402: char *hostname;
1.1 deraadt 2403:
1.25 markus 2404: /* Get arguments from the packet. */
2405: port = packet_get_int();
2406: hostname = packet_get_string(NULL);
2407: host_port = packet_get_int();
2408:
1.27 markus 2409: /*
2410: * Check that an unprivileged user is not trying to forward a
2411: * privileged port.
2412: */
1.25 markus 2413: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2414: packet_disconnect(
2415: "Requested forwarding of port %d but user is not root.",
2416: port);
2417: if (host_port == 0)
2418: packet_disconnect("Dynamic forwarding denied.");
2419:
1.73 markus 2420: /* Initiate forwarding */
1.160 markus 2421: channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
1.25 markus 2422:
2423: /* Free the argument string. */
2424: xfree(hostname);
1.1 deraadt 2425: }
2426:
1.99 markus 2427: /*
2428: * Permits opening to any host/port if permitted_opens[] is empty. This is
2429: * usually called by the server, because the user could connect to any port
2430: * anyway, and the server has no way to know but to trust the client anyway.
2431: */
2432: void
1.142 itojun 2433: channel_permit_all_opens(void)
1.99 markus 2434: {
2435: if (num_permitted_opens == 0)
2436: all_opens_permitted = 1;
2437: }
2438:
1.101 markus 2439: void
1.99 markus 2440: channel_add_permitted_opens(char *host, int port)
2441: {
2442: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2443: fatal("channel_request_remote_forwarding: too many forwards");
2444: debug("allow port forwarding to host %s port %d", host, port);
2445:
2446: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2447: permitted_opens[num_permitted_opens].port_to_connect = port;
2448: num_permitted_opens++;
2449:
2450: all_opens_permitted = 0;
2451: }
2452:
1.101 markus 2453: void
1.99 markus 2454: channel_clear_permitted_opens(void)
2455: {
2456: int i;
2457:
2458: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2459: if (permitted_opens[i].host_to_connect != NULL)
2460: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2461: num_permitted_opens = 0;
2462:
2463: }
2464:
2465:
2466: /* return socket to remote host, port */
1.127 itojun 2467: static int
1.99 markus 2468: connect_to(const char *host, u_short port)
1.41 markus 2469: {
2470: struct addrinfo hints, *ai, *aitop;
2471: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2472: int gaierr;
2473: int sock = -1;
2474:
2475: memset(&hints, 0, sizeof(hints));
2476: hints.ai_family = IPv4or6;
2477: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2478: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2479: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2480: error("connect_to %.100s: unknown host (%s)", host,
2481: gai_strerror(gaierr));
1.41 markus 2482: return -1;
2483: }
2484: for (ai = aitop; ai; ai = ai->ai_next) {
2485: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2486: continue;
2487: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2488: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2489: error("connect_to: getnameinfo failed");
1.41 markus 2490: continue;
2491: }
1.189 markus 2492: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2493: if (sock < 0) {
1.186 djm 2494: if (ai->ai_next == NULL)
2495: error("socket: %.100s", strerror(errno));
2496: else
2497: verbose("socket: %.100s", strerror(errno));
1.41 markus 2498: continue;
2499: }
1.80 markus 2500: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2501: fatal("connect_to: F_SETFL: %s", strerror(errno));
2502: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2503: errno != EINPROGRESS) {
1.99 markus 2504: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2505: strerror(errno));
2506: close(sock);
1.89 stevesk 2507: continue; /* fail -- try next */
1.41 markus 2508: }
2509: break; /* success */
2510:
2511: }
2512: freeaddrinfo(aitop);
2513: if (!ai) {
1.99 markus 2514: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2515: return -1;
2516: }
2517: /* success */
1.169 stevesk 2518: set_nodelay(sock);
1.41 markus 2519: return sock;
2520: }
1.99 markus 2521:
1.73 markus 2522: int
1.130 stevesk 2523: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2524: {
2525: int i;
1.99 markus 2526:
1.73 markus 2527: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2528: if (permitted_opens[i].host_to_connect != NULL &&
2529: permitted_opens[i].listen_port == listen_port)
1.99 markus 2530: return connect_to(
1.73 markus 2531: permitted_opens[i].host_to_connect,
2532: permitted_opens[i].port_to_connect);
1.74 markus 2533: error("WARNING: Server requests forwarding for unknown listen_port %d",
2534: listen_port);
1.73 markus 2535: return -1;
2536: }
2537:
1.99 markus 2538: /* Check if connecting to that port is permitted and connect. */
2539: int
2540: channel_connect_to(const char *host, u_short port)
2541: {
2542: int i, permit;
2543:
2544: permit = all_opens_permitted;
2545: if (!permit) {
2546: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2547: if (permitted_opens[i].host_to_connect != NULL &&
2548: permitted_opens[i].port_to_connect == port &&
1.99 markus 2549: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2550: permit = 1;
2551:
2552: }
2553: if (!permit) {
1.188 itojun 2554: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2555: "but the request was denied.", host, port);
2556: return -1;
2557: }
2558: return connect_to(host, port);
1.204 ! djm 2559: }
! 2560:
! 2561: void
! 2562: channel_send_window_changes(void)
! 2563: {
! 2564: int i;
! 2565: struct winsize ws;
! 2566:
! 2567: for (i = 0; i < channels_alloc; i++) {
! 2568: if (channels[i] == NULL ||
! 2569: channels[i]->type != SSH_CHANNEL_OPEN)
! 2570: continue;
! 2571: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
! 2572: continue;
! 2573: channel_request_start(i, "window-change", 0);
! 2574: packet_put_int(ws.ws_col);
! 2575: packet_put_int(ws.ws_row);
! 2576: packet_put_int(ws.ws_xpixel);
! 2577: packet_put_int(ws.ws_ypixel);
! 2578: packet_send();
! 2579: }
1.99 markus 2580: }
2581:
1.121 markus 2582: /* -- X11 forwarding */
1.1 deraadt 2583:
1.27 markus 2584: /*
2585: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2586: * Returns 0 and a suitable display number for the DISPLAY variable
2587: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2588: */
1.141 stevesk 2589: int
1.163 stevesk 2590: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.176 deraadt 2591: int single_connection, u_int *display_numberp)
1.1 deraadt 2592: {
1.149 markus 2593: Channel *nc = NULL;
1.31 markus 2594: int display_number, sock;
2595: u_short port;
1.35 markus 2596: struct addrinfo hints, *ai, *aitop;
2597: char strport[NI_MAXSERV];
2598: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2599:
1.33 markus 2600: for (display_number = x11_display_offset;
1.148 deraadt 2601: display_number < MAX_DISPLAYS;
2602: display_number++) {
1.25 markus 2603: port = 6000 + display_number;
1.35 markus 2604: memset(&hints, 0, sizeof(hints));
2605: hints.ai_family = IPv4or6;
1.163 stevesk 2606: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2607: hints.ai_socktype = SOCK_STREAM;
2608: snprintf(strport, sizeof strport, "%d", port);
2609: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2610: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2611: return -1;
1.25 markus 2612: }
1.35 markus 2613: for (ai = aitop; ai; ai = ai->ai_next) {
2614: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2615: continue;
1.189 markus 2616: sock = socket(ai->ai_family, ai->ai_socktype,
2617: ai->ai_protocol);
1.35 markus 2618: if (sock < 0) {
2619: error("socket: %.100s", strerror(errno));
1.203 markus 2620: freeaddrinfo(aitop);
1.141 stevesk 2621: return -1;
1.35 markus 2622: }
2623: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2624: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2625: close(sock);
1.183 itojun 2626:
2627: if (ai->ai_next)
2628: continue;
2629:
1.35 markus 2630: for (n = 0; n < num_socks; n++) {
2631: close(socks[n]);
2632: }
2633: num_socks = 0;
2634: break;
2635: }
2636: socks[num_socks++] = sock;
2637: if (num_socks == NUM_SOCKS)
2638: break;
1.25 markus 2639: }
1.83 stevesk 2640: freeaddrinfo(aitop);
1.35 markus 2641: if (num_socks > 0)
2642: break;
1.25 markus 2643: }
2644: if (display_number >= MAX_DISPLAYS) {
2645: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2646: return -1;
1.25 markus 2647: }
2648: /* Start listening for connections on the socket. */
1.35 markus 2649: for (n = 0; n < num_socks; n++) {
2650: sock = socks[n];
1.199 markus 2651: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2652: error("listen: %.100s", strerror(errno));
2653: close(sock);
1.141 stevesk 2654: return -1;
1.35 markus 2655: }
1.25 markus 2656: }
1.35 markus 2657:
2658: /* Allocate a channel for each socket. */
2659: for (n = 0; n < num_socks; n++) {
2660: sock = socks[n];
1.149 markus 2661: nc = channel_new("x11 listener",
1.51 markus 2662: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2663: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2664: 0, "X11 inet listener", 1);
1.167 markus 2665: nc->single_connection = single_connection;
1.35 markus 2666: }
1.1 deraadt 2667:
1.141 stevesk 2668: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2669: *display_numberp = display_number;
2670: return (0);
1.1 deraadt 2671: }
2672:
1.127 itojun 2673: static int
1.77 markus 2674: connect_local_xsocket(u_int dnr)
1.1 deraadt 2675: {
1.25 markus 2676: int sock;
2677: struct sockaddr_un addr;
2678:
1.147 stevesk 2679: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2680: if (sock < 0)
2681: error("socket: %.100s", strerror(errno));
2682: memset(&addr, 0, sizeof(addr));
2683: addr.sun_family = AF_UNIX;
2684: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
2685: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2686: return sock;
2687: close(sock);
1.25 markus 2688: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2689: return -1;
1.1 deraadt 2690: }
2691:
1.51 markus 2692: int
2693: x11_connect_display(void)
1.1 deraadt 2694: {
1.162 stevesk 2695: int display_number, sock = 0;
1.25 markus 2696: const char *display;
1.51 markus 2697: char buf[1024], *cp;
1.35 markus 2698: struct addrinfo hints, *ai, *aitop;
2699: char strport[NI_MAXSERV];
2700: int gaierr;
1.25 markus 2701:
2702: /* Try to open a socket for the local X server. */
2703: display = getenv("DISPLAY");
2704: if (!display) {
2705: error("DISPLAY not set.");
1.51 markus 2706: return -1;
1.25 markus 2707: }
1.27 markus 2708: /*
2709: * Now we decode the value of the DISPLAY variable and make a
2710: * connection to the real X server.
2711: */
2712:
2713: /*
2714: * Check if it is a unix domain socket. Unix domain displays are in
2715: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2716: */
1.25 markus 2717: if (strncmp(display, "unix:", 5) == 0 ||
2718: display[0] == ':') {
2719: /* Connect to the unix domain socket. */
2720: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2721: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2722: display);
1.51 markus 2723: return -1;
1.25 markus 2724: }
2725: /* Create a socket. */
2726: sock = connect_local_xsocket(display_number);
2727: if (sock < 0)
1.51 markus 2728: return -1;
1.25 markus 2729:
2730: /* OK, we now have a connection to the display. */
1.51 markus 2731: return sock;
1.25 markus 2732: }
1.27 markus 2733: /*
2734: * Connect to an inet socket. The DISPLAY value is supposedly
2735: * hostname:d[.s], where hostname may also be numeric IP address.
2736: */
1.145 stevesk 2737: strlcpy(buf, display, sizeof(buf));
1.25 markus 2738: cp = strchr(buf, ':');
2739: if (!cp) {
2740: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2741: return -1;
1.25 markus 2742: }
2743: *cp = 0;
1.27 markus 2744: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2745: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2746: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2747: display);
1.51 markus 2748: return -1;
1.25 markus 2749: }
1.35 markus 2750:
2751: /* Look up the host address */
2752: memset(&hints, 0, sizeof(hints));
2753: hints.ai_family = IPv4or6;
2754: hints.ai_socktype = SOCK_STREAM;
2755: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2756: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2757: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2758: return -1;
1.25 markus 2759: }
1.35 markus 2760: for (ai = aitop; ai; ai = ai->ai_next) {
2761: /* Create a socket. */
1.189 markus 2762: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2763: if (sock < 0) {
1.194 markus 2764: debug2("socket: %.100s", strerror(errno));
1.41 markus 2765: continue;
2766: }
2767: /* Connect it to the display. */
2768: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2769: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2770: 6000 + display_number, strerror(errno));
2771: close(sock);
2772: continue;
2773: }
2774: /* Success */
2775: break;
1.35 markus 2776: }
2777: freeaddrinfo(aitop);
2778: if (!ai) {
1.49 markus 2779: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2780: strerror(errno));
1.51 markus 2781: return -1;
1.25 markus 2782: }
1.162 stevesk 2783: set_nodelay(sock);
1.51 markus 2784: return sock;
2785: }
2786:
2787: /*
2788: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2789: * the remote channel number. We should do whatever we want, and respond
2790: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2791: */
2792:
2793: void
1.154 markus 2794: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2795: {
1.113 markus 2796: Channel *c = NULL;
2797: int remote_id, sock = 0;
1.51 markus 2798: char *remote_host;
1.25 markus 2799:
1.113 markus 2800: debug("Received X11 open request.");
1.51 markus 2801:
1.113 markus 2802: remote_id = packet_get_int();
1.121 markus 2803:
2804: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2805: remote_host = packet_get_string(NULL);
1.51 markus 2806: } else {
2807: remote_host = xstrdup("unknown (remote did not supply name)");
2808: }
1.152 markus 2809: packet_check_eom();
1.25 markus 2810:
1.51 markus 2811: /* Obtain a connection to the real X display. */
2812: sock = x11_connect_display();
1.113 markus 2813: if (sock != -1) {
2814: /* Allocate a channel for this connection. */
2815: c = channel_new("connected x11 socket",
2816: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2817: remote_host, 1);
1.167 markus 2818: c->remote_id = remote_id;
2819: c->force_drain = 1;
1.113 markus 2820: }
1.190 markus 2821: xfree(remote_host);
1.113 markus 2822: if (c == NULL) {
1.51 markus 2823: /* Send refusal to the remote host. */
2824: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2825: packet_put_int(remote_id);
1.51 markus 2826: } else {
2827: /* Send a confirmation to the remote host. */
2828: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2829: packet_put_int(remote_id);
2830: packet_put_int(c->self);
1.51 markus 2831: }
1.113 markus 2832: packet_send();
1.72 markus 2833: }
2834:
2835: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2836: void
1.154 markus 2837: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2838: {
2839: int rchan = packet_get_int();
1.180 deraadt 2840:
1.143 deraadt 2841: switch (type) {
1.72 markus 2842: case SSH_SMSG_AGENT_OPEN:
2843: error("Warning: ssh server tried agent forwarding.");
2844: break;
2845: case SSH_SMSG_X11_OPEN:
2846: error("Warning: ssh server tried X11 forwarding.");
2847: break;
2848: default:
1.154 markus 2849: error("deny_input_open: type %d", type);
1.72 markus 2850: break;
2851: }
2852: error("Warning: this is probably a break in attempt by a malicious server.");
2853: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2854: packet_put_int(rchan);
2855: packet_send();
1.1 deraadt 2856: }
2857:
1.27 markus 2858: /*
2859: * Requests forwarding of X11 connections, generates fake authentication
2860: * data, and enables authentication spoofing.
1.121 markus 2861: * This should be called in the client only.
1.27 markus 2862: */
1.49 markus 2863: void
1.51 markus 2864: x11_request_forwarding_with_spoofing(int client_session_id,
2865: const char *proto, const char *data)
1.1 deraadt 2866: {
1.77 markus 2867: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2868: u_int i, value, len;
1.25 markus 2869: char *new_data;
2870: int screen_number;
2871: const char *cp;
2872: u_int32_t rand = 0;
2873:
2874: cp = getenv("DISPLAY");
2875: if (cp)
2876: cp = strchr(cp, ':');
2877: if (cp)
2878: cp = strchr(cp, '.');
2879: if (cp)
2880: screen_number = atoi(cp + 1);
2881: else
2882: screen_number = 0;
2883:
2884: /* Save protocol name. */
2885: x11_saved_proto = xstrdup(proto);
2886:
1.27 markus 2887: /*
2888: * Extract real authentication data and generate fake data of the
2889: * same length.
2890: */
1.25 markus 2891: x11_saved_data = xmalloc(data_len);
2892: x11_fake_data = xmalloc(data_len);
2893: for (i = 0; i < data_len; i++) {
2894: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2895: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2896: if (i % 4 == 0)
2897: rand = arc4random();
2898: x11_saved_data[i] = value;
2899: x11_fake_data[i] = rand & 0xff;
2900: rand >>= 8;
2901: }
2902: x11_saved_data_len = data_len;
2903: x11_fake_data_len = data_len;
2904:
2905: /* Convert the fake data into hex. */
1.90 markus 2906: len = 2 * data_len + 1;
2907: new_data = xmalloc(len);
1.25 markus 2908: for (i = 0; i < data_len; i++)
1.90 markus 2909: snprintf(new_data + 2 * i, len - 2 * i,
2910: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2911:
2912: /* Send the request packet. */
1.51 markus 2913: if (compat20) {
2914: channel_request_start(client_session_id, "x11-req", 0);
2915: packet_put_char(0); /* XXX bool single connection */
2916: } else {
2917: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2918: }
2919: packet_put_cstring(proto);
2920: packet_put_cstring(new_data);
1.25 markus 2921: packet_put_int(screen_number);
2922: packet_send();
2923: packet_write_wait();
2924: xfree(new_data);
1.1 deraadt 2925: }
2926:
1.121 markus 2927:
2928: /* -- agent forwarding */
2929:
1.1 deraadt 2930: /* Sends a message to the server to request authentication fd forwarding. */
2931:
1.49 markus 2932: void
1.142 itojun 2933: auth_request_forwarding(void)
1.1 deraadt 2934: {
1.25 markus 2935: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2936: packet_send();
2937: packet_write_wait();
1.1 deraadt 2938: }
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