Annotation of src/usr.bin/ssh/channels.c, Revision 1.244
1.244 ! djm 1: /* $OpenBSD$ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.234 stevesk 43:
44: #include <sys/ioctl.h>
1.235 stevesk 45: #include <sys/types.h>
46: #include <sys/un.h>
1.233 stevesk 47:
48: #include <termios.h>
1.1 deraadt 49:
50: #include "ssh.h"
1.82 markus 51: #include "ssh1.h"
52: #include "ssh2.h"
1.1 deraadt 53: #include "packet.h"
54: #include "xmalloc.h"
1.82 markus 55: #include "log.h"
56: #include "misc.h"
1.14 markus 57: #include "channels.h"
58: #include "compat.h"
1.82 markus 59: #include "canohost.h"
1.64 markus 60: #include "key.h"
61: #include "authfd.h"
1.147 stevesk 62: #include "pathnames.h"
1.193 markus 63: #include "bufaux.h"
1.1 deraadt 64:
1.121 markus 65: /* -- channel core */
1.12 markus 66:
1.27 markus 67: /*
68: * Pointer to an array containing all allocated channels. The array is
69: * dynamically extended as needed.
70: */
1.113 markus 71: static Channel **channels = NULL;
1.1 deraadt 72:
1.27 markus 73: /*
74: * Size of the channel array. All slots of the array must always be
1.113 markus 75: * initialized (at least the type field); unused slots set to NULL
1.27 markus 76: */
1.209 avsm 77: static u_int channels_alloc = 0;
1.1 deraadt 78:
1.27 markus 79: /*
80: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 81: * updated in channel_new.
1.27 markus 82: */
1.84 markus 83: static int channel_max_fd = 0;
1.1 deraadt 84:
85:
1.121 markus 86: /* -- tcp forwarding */
1.1 deraadt 87:
1.27 markus 88: /*
89: * Data structure for storing which hosts are permitted for forward requests.
90: * The local sides of any remote forwards are stored in this array to prevent
91: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
92: * network (which might be behind a firewall).
93: */
1.25 markus 94: typedef struct {
1.41 markus 95: char *host_to_connect; /* Connect to 'host'. */
96: u_short port_to_connect; /* Connect to 'port'. */
97: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 98: } ForwardPermission;
99:
100: /* List of all permitted host/port pairs to connect. */
101: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 102:
1.1 deraadt 103: /* Number of permitted host/port pairs in the array. */
104: static int num_permitted_opens = 0;
1.27 markus 105: /*
106: * If this is true, all opens are permitted. This is the case on the server
107: * on which we have to trust the client anyway, and the user could do
108: * anything after logging in anyway.
109: */
1.1 deraadt 110: static int all_opens_permitted = 0;
111:
1.121 markus 112:
113: /* -- X11 forwarding */
114:
115: /* Maximum number of fake X11 displays to try. */
116: #define MAX_DISPLAYS 1000
117:
1.219 djm 118: /* Saved X11 local (client) display. */
119: static char *x11_saved_display = NULL;
120:
1.121 markus 121: /* Saved X11 authentication protocol name. */
122: static char *x11_saved_proto = NULL;
123:
124: /* Saved X11 authentication data. This is the real data. */
125: static char *x11_saved_data = NULL;
126: static u_int x11_saved_data_len = 0;
127:
128: /*
129: * Fake X11 authentication data. This is what the server will be sending us;
130: * we should replace any occurrences of this by the real data.
131: */
1.240 deraadt 132: static u_char *x11_fake_data = NULL;
1.121 markus 133: static u_int x11_fake_data_len;
134:
135:
136: /* -- agent forwarding */
137:
138: #define NUM_SOCKS 10
139:
1.82 markus 140: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 141: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 142:
1.121 markus 143: /* helper */
1.127 itojun 144: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 145:
1.121 markus 146: /* -- channel core */
1.41 markus 147:
148: Channel *
1.229 markus 149: channel_by_id(int id)
1.41 markus 150: {
151: Channel *c;
1.113 markus 152:
1.209 avsm 153: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 154: logit("channel_by_id: %d: bad id", id);
1.41 markus 155: return NULL;
156: }
1.113 markus 157: c = channels[id];
158: if (c == NULL) {
1.229 markus 159: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 160: return NULL;
161: }
162: return c;
1.55 markus 163: }
164:
1.27 markus 165: /*
1.229 markus 166: * Returns the channel if it is allowed to receive protocol messages.
167: * Private channels, like listening sockets, may not receive messages.
168: */
169: Channel *
170: channel_lookup(int id)
171: {
172: Channel *c;
173:
174: if ((c = channel_by_id(id)) == NULL)
175: return (NULL);
176:
1.237 deraadt 177: switch (c->type) {
1.229 markus 178: case SSH_CHANNEL_X11_OPEN:
179: case SSH_CHANNEL_LARVAL:
180: case SSH_CHANNEL_CONNECTING:
181: case SSH_CHANNEL_DYNAMIC:
182: case SSH_CHANNEL_OPENING:
183: case SSH_CHANNEL_OPEN:
184: case SSH_CHANNEL_INPUT_DRAINING:
185: case SSH_CHANNEL_OUTPUT_DRAINING:
186: return (c);
187: }
188: logit("Non-public channel %d, type %d.", id, c->type);
189: return (NULL);
190: }
191:
192: /*
1.55 markus 193: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 194: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 195: */
1.127 itojun 196: static void
1.71 markus 197: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
198: int extusage, int nonblock)
1.1 deraadt 199: {
1.25 markus 200: /* Update the maximum file descriptor value. */
1.84 markus 201: channel_max_fd = MAX(channel_max_fd, rfd);
202: channel_max_fd = MAX(channel_max_fd, wfd);
203: channel_max_fd = MAX(channel_max_fd, efd);
204:
1.27 markus 205: /* XXX set close-on-exec -markus */
1.55 markus 206:
1.52 markus 207: c->rfd = rfd;
208: c->wfd = wfd;
209: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 210: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 211: c->efd = efd;
212: c->extended_usage = extusage;
1.71 markus 213:
1.91 markus 214: /* XXX ugly hack: nonblock is only set by the server */
215: if (nonblock && isatty(c->rfd)) {
1.194 markus 216: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 217: c->isatty = 1;
218: if (!isatty(c->wfd)) {
1.94 markus 219: error("channel %d: wfd %d is not a tty?",
1.91 markus 220: c->self, c->wfd);
221: }
222: } else {
223: c->isatty = 0;
224: }
225:
1.71 markus 226: /* enable nonblocking mode */
227: if (nonblock) {
228: if (rfd != -1)
229: set_nonblock(rfd);
230: if (wfd != -1)
231: set_nonblock(wfd);
232: if (efd != -1)
233: set_nonblock(efd);
234: }
1.52 markus 235: }
236:
237: /*
238: * Allocate a new channel object and set its type and socket. This will cause
239: * remote_name to be freed.
240: */
1.113 markus 241: Channel *
1.52 markus 242: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 243: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 244: {
1.209 avsm 245: int found;
246: u_int i;
1.52 markus 247: Channel *c;
1.25 markus 248:
249: /* Do initial allocation if this is the first call. */
250: if (channels_alloc == 0) {
251: channels_alloc = 10;
1.242 djm 252: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 253: for (i = 0; i < channels_alloc; i++)
1.113 markus 254: channels[i] = NULL;
1.25 markus 255: }
256: /* Try to find a free slot where to put the new channel. */
257: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 258: if (channels[i] == NULL) {
1.25 markus 259: /* Found a free slot. */
1.209 avsm 260: found = (int)i;
1.25 markus 261: break;
262: }
1.209 avsm 263: if (found < 0) {
1.27 markus 264: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 265: found = channels_alloc;
1.179 markus 266: if (channels_alloc > 10000)
267: fatal("channel_new: internal error: channels_alloc %d "
268: "too big.", channels_alloc);
1.243 djm 269: channels = xrealloc(channels, channels_alloc + 10,
270: sizeof(Channel *));
1.195 markus 271: channels_alloc += 10;
1.70 markus 272: debug2("channel: expanding %d", channels_alloc);
1.25 markus 273: for (i = found; i < channels_alloc; i++)
1.113 markus 274: channels[i] = NULL;
1.25 markus 275: }
1.113 markus 276: /* Initialize and return new channel. */
1.242 djm 277: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 278: buffer_init(&c->input);
279: buffer_init(&c->output);
1.41 markus 280: buffer_init(&c->extended);
1.159 markus 281: c->ostate = CHAN_OUTPUT_OPEN;
282: c->istate = CHAN_INPUT_OPEN;
283: c->flags = 0;
1.71 markus 284: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 285: c->self = found;
286: c->type = type;
1.41 markus 287: c->ctype = ctype;
1.51 markus 288: c->local_window = window;
289: c->local_window_max = window;
290: c->local_consumed = 0;
291: c->local_maxpacket = maxpack;
1.25 markus 292: c->remote_id = -1;
1.190 markus 293: c->remote_name = xstrdup(remote_name);
1.41 markus 294: c->remote_window = 0;
295: c->remote_maxpacket = 0;
1.133 markus 296: c->force_drain = 0;
1.149 markus 297: c->single_connection = 0;
1.131 markus 298: c->detach_user = NULL;
1.225 djm 299: c->detach_close = 0;
1.165 markus 300: c->confirm = NULL;
1.204 djm 301: c->confirm_ctx = NULL;
1.65 markus 302: c->input_filter = NULL;
1.231 reyk 303: c->output_filter = NULL;
1.25 markus 304: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 305: return c;
1.1 deraadt 306: }
1.52 markus 307:
1.132 markus 308: static int
309: channel_find_maxfd(void)
310: {
1.209 avsm 311: u_int i;
312: int max = 0;
1.132 markus 313: Channel *c;
314:
315: for (i = 0; i < channels_alloc; i++) {
316: c = channels[i];
317: if (c != NULL) {
318: max = MAX(max, c->rfd);
319: max = MAX(max, c->wfd);
320: max = MAX(max, c->efd);
321: }
322: }
323: return max;
324: }
325:
326: int
327: channel_close_fd(int *fdp)
328: {
329: int ret = 0, fd = *fdp;
330:
331: if (fd != -1) {
332: ret = close(fd);
333: *fdp = -1;
334: if (fd == channel_max_fd)
335: channel_max_fd = channel_find_maxfd();
336: }
337: return ret;
338: }
339:
1.52 markus 340: /* Close all channel fd/socket. */
1.127 itojun 341: static void
1.52 markus 342: channel_close_fds(Channel *c)
343: {
1.204 djm 344: debug3("channel %d: close_fds r %d w %d e %d c %d",
345: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 346:
1.132 markus 347: channel_close_fd(&c->sock);
1.204 djm 348: channel_close_fd(&c->ctl_fd);
1.132 markus 349: channel_close_fd(&c->rfd);
350: channel_close_fd(&c->wfd);
351: channel_close_fd(&c->efd);
1.121 markus 352: }
353:
354: /* Free the channel and close its fd/socket. */
355: void
356: channel_free(Channel *c)
357: {
358: char *s;
1.209 avsm 359: u_int i, n;
1.121 markus 360:
361: for (n = 0, i = 0; i < channels_alloc; i++)
362: if (channels[i])
363: n++;
1.209 avsm 364: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 365: c->remote_name ? c->remote_name : "???", n);
366:
367: s = channel_open_message();
1.194 markus 368: debug3("channel %d: status: %s", c->self, s);
1.121 markus 369: xfree(s);
370:
371: if (c->sock != -1)
372: shutdown(c->sock, SHUT_RDWR);
1.204 djm 373: if (c->ctl_fd != -1)
374: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 375: channel_close_fds(c);
376: buffer_free(&c->input);
377: buffer_free(&c->output);
378: buffer_free(&c->extended);
379: if (c->remote_name) {
380: xfree(c->remote_name);
381: c->remote_name = NULL;
382: }
383: channels[c->self] = NULL;
384: xfree(c);
385: }
386:
387: void
1.126 markus 388: channel_free_all(void)
1.121 markus 389: {
1.209 avsm 390: u_int i;
1.121 markus 391:
1.126 markus 392: for (i = 0; i < channels_alloc; i++)
393: if (channels[i] != NULL)
394: channel_free(channels[i]);
1.131 markus 395: }
396:
1.121 markus 397: /*
398: * Closes the sockets/fds of all channels. This is used to close extra file
399: * descriptors after a fork.
400: */
401: void
1.142 itojun 402: channel_close_all(void)
1.121 markus 403: {
1.209 avsm 404: u_int i;
1.121 markus 405:
406: for (i = 0; i < channels_alloc; i++)
407: if (channels[i] != NULL)
408: channel_close_fds(channels[i]);
409: }
410:
411: /*
1.131 markus 412: * Stop listening to channels.
413: */
414: void
415: channel_stop_listening(void)
416: {
1.209 avsm 417: u_int i;
1.131 markus 418: Channel *c;
419:
420: for (i = 0; i < channels_alloc; i++) {
421: c = channels[i];
422: if (c != NULL) {
423: switch (c->type) {
424: case SSH_CHANNEL_AUTH_SOCKET:
425: case SSH_CHANNEL_PORT_LISTENER:
426: case SSH_CHANNEL_RPORT_LISTENER:
427: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 428: channel_close_fd(&c->sock);
1.131 markus 429: channel_free(c);
430: break;
431: }
432: }
433: }
434: }
435:
436: /*
1.121 markus 437: * Returns true if no channel has too much buffered data, and false if one or
438: * more channel is overfull.
439: */
440: int
1.142 itojun 441: channel_not_very_much_buffered_data(void)
1.121 markus 442: {
443: u_int i;
444: Channel *c;
445:
446: for (i = 0; i < channels_alloc; i++) {
447: c = channels[i];
448: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 449: #if 0
450: if (!compat20 &&
451: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 452: debug2("channel %d: big input buffer %d",
1.121 markus 453: c->self, buffer_len(&c->input));
454: return 0;
455: }
1.136 markus 456: #endif
1.121 markus 457: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 458: debug2("channel %d: big output buffer %u > %u",
1.136 markus 459: c->self, buffer_len(&c->output),
460: packet_get_maxsize());
1.121 markus 461: return 0;
462: }
463: }
464: }
465: return 1;
466: }
467:
468: /* Returns true if any channel is still open. */
469: int
1.142 itojun 470: channel_still_open(void)
1.121 markus 471: {
1.209 avsm 472: u_int i;
1.121 markus 473: Channel *c;
474:
475: for (i = 0; i < channels_alloc; i++) {
476: c = channels[i];
477: if (c == NULL)
478: continue;
479: switch (c->type) {
480: case SSH_CHANNEL_X11_LISTENER:
481: case SSH_CHANNEL_PORT_LISTENER:
482: case SSH_CHANNEL_RPORT_LISTENER:
483: case SSH_CHANNEL_CLOSED:
484: case SSH_CHANNEL_AUTH_SOCKET:
485: case SSH_CHANNEL_DYNAMIC:
486: case SSH_CHANNEL_CONNECTING:
487: case SSH_CHANNEL_ZOMBIE:
488: continue;
489: case SSH_CHANNEL_LARVAL:
490: if (!compat20)
491: fatal("cannot happen: SSH_CHANNEL_LARVAL");
492: continue;
493: case SSH_CHANNEL_OPENING:
494: case SSH_CHANNEL_OPEN:
495: case SSH_CHANNEL_X11_OPEN:
496: return 1;
497: case SSH_CHANNEL_INPUT_DRAINING:
498: case SSH_CHANNEL_OUTPUT_DRAINING:
499: if (!compat13)
500: fatal("cannot happen: OUT_DRAIN");
501: return 1;
502: default:
503: fatal("channel_still_open: bad channel type %d", c->type);
504: /* NOTREACHED */
505: }
506: }
507: return 0;
508: }
509:
510: /* Returns the id of an open channel suitable for keepaliving */
511: int
1.142 itojun 512: channel_find_open(void)
1.121 markus 513: {
1.209 avsm 514: u_int i;
1.121 markus 515: Channel *c;
516:
517: for (i = 0; i < channels_alloc; i++) {
518: c = channels[i];
1.206 djm 519: if (c == NULL || c->remote_id < 0)
1.121 markus 520: continue;
521: switch (c->type) {
522: case SSH_CHANNEL_CLOSED:
523: case SSH_CHANNEL_DYNAMIC:
524: case SSH_CHANNEL_X11_LISTENER:
525: case SSH_CHANNEL_PORT_LISTENER:
526: case SSH_CHANNEL_RPORT_LISTENER:
527: case SSH_CHANNEL_OPENING:
528: case SSH_CHANNEL_CONNECTING:
529: case SSH_CHANNEL_ZOMBIE:
530: continue;
531: case SSH_CHANNEL_LARVAL:
532: case SSH_CHANNEL_AUTH_SOCKET:
533: case SSH_CHANNEL_OPEN:
534: case SSH_CHANNEL_X11_OPEN:
535: return i;
536: case SSH_CHANNEL_INPUT_DRAINING:
537: case SSH_CHANNEL_OUTPUT_DRAINING:
538: if (!compat13)
539: fatal("cannot happen: OUT_DRAIN");
540: return i;
541: default:
542: fatal("channel_find_open: bad channel type %d", c->type);
543: /* NOTREACHED */
544: }
545: }
546: return -1;
547: }
548:
549:
550: /*
551: * Returns a message describing the currently open forwarded connections,
552: * suitable for sending to the client. The message contains crlf pairs for
553: * newlines.
554: */
555: char *
1.142 itojun 556: channel_open_message(void)
1.121 markus 557: {
558: Buffer buffer;
559: Channel *c;
560: char buf[1024], *cp;
1.209 avsm 561: u_int i;
1.121 markus 562:
563: buffer_init(&buffer);
564: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
565: buffer_append(&buffer, buf, strlen(buf));
566: for (i = 0; i < channels_alloc; i++) {
567: c = channels[i];
568: if (c == NULL)
569: continue;
570: switch (c->type) {
571: case SSH_CHANNEL_X11_LISTENER:
572: case SSH_CHANNEL_PORT_LISTENER:
573: case SSH_CHANNEL_RPORT_LISTENER:
574: case SSH_CHANNEL_CLOSED:
575: case SSH_CHANNEL_AUTH_SOCKET:
576: case SSH_CHANNEL_ZOMBIE:
577: continue;
578: case SSH_CHANNEL_LARVAL:
579: case SSH_CHANNEL_OPENING:
580: case SSH_CHANNEL_CONNECTING:
581: case SSH_CHANNEL_DYNAMIC:
582: case SSH_CHANNEL_OPEN:
583: case SSH_CHANNEL_X11_OPEN:
584: case SSH_CHANNEL_INPUT_DRAINING:
585: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 586: snprintf(buf, sizeof buf,
587: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 588: c->self, c->remote_name,
589: c->type, c->remote_id,
590: c->istate, buffer_len(&c->input),
591: c->ostate, buffer_len(&c->output),
1.204 djm 592: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 593: buffer_append(&buffer, buf, strlen(buf));
594: continue;
595: default:
596: fatal("channel_open_message: bad channel type %d", c->type);
597: /* NOTREACHED */
598: }
599: }
600: buffer_append(&buffer, "\0", 1);
601: cp = xstrdup(buffer_ptr(&buffer));
602: buffer_free(&buffer);
603: return cp;
604: }
605:
606: void
607: channel_send_open(int id)
608: {
609: Channel *c = channel_lookup(id);
1.180 deraadt 610:
1.121 markus 611: if (c == NULL) {
1.188 itojun 612: logit("channel_send_open: %d: bad id", id);
1.121 markus 613: return;
614: }
1.184 markus 615: debug2("channel %d: send open", id);
1.121 markus 616: packet_start(SSH2_MSG_CHANNEL_OPEN);
617: packet_put_cstring(c->ctype);
618: packet_put_int(c->self);
619: packet_put_int(c->local_window);
620: packet_put_int(c->local_maxpacket);
621: packet_send();
622: }
623:
624: void
1.184 markus 625: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 626: {
1.184 markus 627: Channel *c = channel_lookup(id);
1.180 deraadt 628:
1.121 markus 629: if (c == NULL) {
1.188 itojun 630: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 631: return;
632: }
1.204 djm 633: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 634: packet_start(SSH2_MSG_CHANNEL_REQUEST);
635: packet_put_int(c->remote_id);
636: packet_put_cstring(service);
637: packet_put_char(wantconfirm);
638: }
1.241 deraadt 639:
1.121 markus 640: void
1.204 djm 641: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 642: {
643: Channel *c = channel_lookup(id);
1.180 deraadt 644:
1.121 markus 645: if (c == NULL) {
1.188 itojun 646: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 647: return;
648: }
1.165 markus 649: c->confirm = fn;
1.204 djm 650: c->confirm_ctx = ctx;
1.121 markus 651: }
1.241 deraadt 652:
1.121 markus 653: void
1.225 djm 654: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 655: {
1.229 markus 656: Channel *c = channel_by_id(id);
1.180 deraadt 657:
1.121 markus 658: if (c == NULL) {
1.188 itojun 659: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 660: return;
661: }
1.131 markus 662: c->detach_user = fn;
1.225 djm 663: c->detach_close = do_close;
1.121 markus 664: }
1.241 deraadt 665:
1.121 markus 666: void
667: channel_cancel_cleanup(int id)
668: {
1.229 markus 669: Channel *c = channel_by_id(id);
1.180 deraadt 670:
1.121 markus 671: if (c == NULL) {
1.188 itojun 672: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 673: return;
1.52 markus 674: }
1.131 markus 675: c->detach_user = NULL;
1.225 djm 676: c->detach_close = 0;
1.121 markus 677: }
1.241 deraadt 678:
1.121 markus 679: void
1.231 reyk 680: channel_register_filter(int id, channel_infilter_fn *ifn,
681: channel_outfilter_fn *ofn)
1.121 markus 682: {
683: Channel *c = channel_lookup(id);
1.180 deraadt 684:
1.121 markus 685: if (c == NULL) {
1.188 itojun 686: logit("channel_register_filter: %d: bad id", id);
1.121 markus 687: return;
1.52 markus 688: }
1.231 reyk 689: c->input_filter = ifn;
690: c->output_filter = ofn;
1.52 markus 691: }
692:
1.49 markus 693: void
1.121 markus 694: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 695: int extusage, int nonblock, u_int window_max)
1.1 deraadt 696: {
1.121 markus 697: Channel *c = channel_lookup(id);
1.180 deraadt 698:
1.121 markus 699: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
700: fatal("channel_activate for non-larval channel %d.", id);
701: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
702: c->type = SSH_CHANNEL_OPEN;
1.168 markus 703: c->local_window = c->local_window_max = window_max;
1.121 markus 704: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
705: packet_put_int(c->remote_id);
706: packet_put_int(c->local_window);
707: packet_send();
1.1 deraadt 708: }
709:
1.27 markus 710: /*
1.41 markus 711: * 'channel_pre*' are called just before select() to add any bits relevant to
712: * channels in the select bitmasks.
713: */
714: /*
715: * 'channel_post*': perform any appropriate operations for channels which
716: * have events pending.
1.27 markus 717: */
1.237 deraadt 718: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 719: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
720: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
721:
1.127 itojun 722: static void
1.237 deraadt 723: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 724: {
725: FD_SET(c->sock, readset);
726: }
727:
1.127 itojun 728: static void
1.237 deraadt 729: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 730: {
731: debug3("channel %d: waiting for connection", c->self);
732: FD_SET(c->sock, writeset);
733: }
734:
1.127 itojun 735: static void
1.237 deraadt 736: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 737: {
738: if (buffer_len(&c->input) < packet_get_maxsize())
739: FD_SET(c->sock, readset);
740: if (buffer_len(&c->output) > 0)
741: FD_SET(c->sock, writeset);
742: }
1.1 deraadt 743:
1.127 itojun 744: static void
1.237 deraadt 745: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 746: {
1.157 markus 747: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 748:
1.214 markus 749: /* check buffer limits */
750: limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
751:
1.44 markus 752: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 753: limit > 0 &&
754: buffer_len(&c->input) < limit)
1.44 markus 755: FD_SET(c->rfd, readset);
756: if (c->ostate == CHAN_OUTPUT_OPEN ||
757: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
758: if (buffer_len(&c->output) > 0) {
759: FD_SET(c->wfd, writeset);
760: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 761: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 762: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
763: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 764: else
765: chan_obuf_empty(c);
1.44 markus 766: }
767: }
768: /** XXX check close conditions, too */
1.157 markus 769: if (compat20 && c->efd != -1) {
1.44 markus 770: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
771: buffer_len(&c->extended) > 0)
772: FD_SET(c->efd, writeset);
1.172 markus 773: else if (!(c->flags & CHAN_EOF_SENT) &&
774: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 775: buffer_len(&c->extended) < c->remote_window)
776: FD_SET(c->efd, readset);
777: }
1.204 djm 778: /* XXX: What about efd? races? */
1.208 deraadt 779: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 780: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
781: FD_SET(c->ctl_fd, readset);
1.44 markus 782: }
783:
1.127 itojun 784: static void
1.237 deraadt 785: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 786: {
787: if (buffer_len(&c->input) == 0) {
788: packet_start(SSH_MSG_CHANNEL_CLOSE);
789: packet_put_int(c->remote_id);
790: packet_send();
791: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 792: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 793: }
794: }
795:
1.127 itojun 796: static void
1.237 deraadt 797: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 798: {
799: if (buffer_len(&c->output) == 0)
1.113 markus 800: chan_mark_dead(c);
1.49 markus 801: else
1.41 markus 802: FD_SET(c->sock, writeset);
803: }
804:
805: /*
806: * This is a special state for X11 authentication spoofing. An opened X11
807: * connection (when authentication spoofing is being done) remains in this
808: * state until the first packet has been completely read. The authentication
809: * data in that packet is then substituted by the real data if it matches the
810: * fake data, and the channel is put into normal mode.
1.51 markus 811: * XXX All this happens at the client side.
1.121 markus 812: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 813: */
1.127 itojun 814: static int
1.121 markus 815: x11_open_helper(Buffer *b)
1.1 deraadt 816: {
1.77 markus 817: u_char *ucp;
818: u_int proto_len, data_len;
1.25 markus 819:
1.41 markus 820: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 821: if (buffer_len(b) < 12)
1.41 markus 822: return 0;
823:
824: /* Parse the lengths of variable-length fields. */
1.155 stevesk 825: ucp = buffer_ptr(b);
1.41 markus 826: if (ucp[0] == 0x42) { /* Byte order MSB first. */
827: proto_len = 256 * ucp[6] + ucp[7];
828: data_len = 256 * ucp[8] + ucp[9];
829: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
830: proto_len = ucp[6] + 256 * ucp[7];
831: data_len = ucp[8] + 256 * ucp[9];
832: } else {
1.194 markus 833: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 834: ucp[0]);
1.41 markus 835: return -1;
836: }
837:
838: /* Check if the whole packet is in buffer. */
1.121 markus 839: if (buffer_len(b) <
1.41 markus 840: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
841: return 0;
842:
843: /* Check if authentication protocol matches. */
844: if (proto_len != strlen(x11_saved_proto) ||
845: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 846: debug2("X11 connection uses different authentication protocol.");
1.41 markus 847: return -1;
848: }
849: /* Check if authentication data matches our fake data. */
850: if (data_len != x11_fake_data_len ||
851: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
852: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 853: debug2("X11 auth data does not match fake data.");
1.41 markus 854: return -1;
855: }
856: /* Check fake data length */
857: if (x11_fake_data_len != x11_saved_data_len) {
858: error("X11 fake_data_len %d != saved_data_len %d",
859: x11_fake_data_len, x11_saved_data_len);
860: return -1;
861: }
862: /*
863: * Received authentication protocol and data match
864: * our fake data. Substitute the fake data with real
865: * data.
866: */
867: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
868: x11_saved_data, x11_saved_data_len);
869: return 1;
870: }
871:
1.127 itojun 872: static void
1.237 deraadt 873: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 874: {
1.121 markus 875: int ret = x11_open_helper(&c->output);
1.180 deraadt 876:
1.41 markus 877: if (ret == 1) {
878: /* Start normal processing for the channel. */
879: c->type = SSH_CHANNEL_OPEN;
1.47 markus 880: channel_pre_open_13(c, readset, writeset);
1.41 markus 881: } else if (ret == -1) {
882: /*
883: * We have received an X11 connection that has bad
884: * authentication information.
885: */
1.188 itojun 886: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 887: buffer_clear(&c->input);
888: buffer_clear(&c->output);
1.132 markus 889: channel_close_fd(&c->sock);
1.41 markus 890: c->sock = -1;
891: c->type = SSH_CHANNEL_CLOSED;
892: packet_start(SSH_MSG_CHANNEL_CLOSE);
893: packet_put_int(c->remote_id);
894: packet_send();
895: }
896: }
1.25 markus 897:
1.127 itojun 898: static void
1.237 deraadt 899: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 900: {
1.121 markus 901: int ret = x11_open_helper(&c->output);
1.133 markus 902:
903: /* c->force_drain = 1; */
904:
1.41 markus 905: if (ret == 1) {
906: c->type = SSH_CHANNEL_OPEN;
1.157 markus 907: channel_pre_open(c, readset, writeset);
1.41 markus 908: } else if (ret == -1) {
1.188 itojun 909: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 910: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 911: chan_read_failed(c);
912: buffer_clear(&c->input);
913: chan_ibuf_empty(c);
914: buffer_clear(&c->output);
915: /* for proto v1, the peer will send an IEOF */
916: if (compat20)
917: chan_write_failed(c);
918: else
919: c->type = SSH_CHANNEL_OPEN;
1.194 markus 920: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 921: }
922: }
1.25 markus 923:
1.104 markus 924: /* try to decode a socks4 header */
1.127 itojun 925: static int
1.237 deraadt 926: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 927: {
1.181 markus 928: char *p, *host;
1.217 djm 929: u_int len, have, i, found;
1.148 deraadt 930: char username[256];
1.103 markus 931: struct {
932: u_int8_t version;
933: u_int8_t command;
934: u_int16_t dest_port;
1.104 markus 935: struct in_addr dest_addr;
1.103 markus 936: } s4_req, s4_rsp;
937:
1.104 markus 938: debug2("channel %d: decode socks4", c->self);
1.109 markus 939:
940: have = buffer_len(&c->input);
941: len = sizeof(s4_req);
942: if (have < len)
943: return 0;
944: p = buffer_ptr(&c->input);
945: for (found = 0, i = len; i < have; i++) {
946: if (p[i] == '\0') {
947: found = 1;
948: break;
949: }
950: if (i > 1024) {
951: /* the peer is probably sending garbage */
952: debug("channel %d: decode socks4: too long",
953: c->self);
954: return -1;
955: }
956: }
957: if (!found)
958: return 0;
1.103 markus 959: buffer_get(&c->input, (char *)&s4_req.version, 1);
960: buffer_get(&c->input, (char *)&s4_req.command, 1);
961: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 962: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 963: have = buffer_len(&c->input);
1.103 markus 964: p = buffer_ptr(&c->input);
965: len = strlen(p);
1.106 markus 966: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 967: if (len > have)
1.104 markus 968: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 969: c->self, len, have);
970: strlcpy(username, p, sizeof(username));
971: buffer_consume(&c->input, len);
972: buffer_consume(&c->input, 1); /* trailing '\0' */
973:
1.104 markus 974: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 975: strlcpy(c->path, host, sizeof(c->path));
976: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 977:
1.194 markus 978: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 979: c->self, host, c->host_port, s4_req.command);
1.103 markus 980:
1.104 markus 981: if (s4_req.command != 1) {
982: debug("channel %d: cannot handle: socks4 cn %d",
983: c->self, s4_req.command);
984: return -1;
1.103 markus 985: }
1.104 markus 986: s4_rsp.version = 0; /* vn: 0 for reply */
987: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 988: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 989: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 990: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 991: return 1;
992: }
993:
1.193 markus 994: /* try to decode a socks5 header */
995: #define SSH_SOCKS5_AUTHDONE 0x1000
996: #define SSH_SOCKS5_NOAUTH 0x00
997: #define SSH_SOCKS5_IPV4 0x01
998: #define SSH_SOCKS5_DOMAIN 0x03
999: #define SSH_SOCKS5_IPV6 0x04
1000: #define SSH_SOCKS5_CONNECT 0x01
1001: #define SSH_SOCKS5_SUCCESS 0x00
1002:
1003: static int
1.237 deraadt 1004: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1005: {
1006: struct {
1007: u_int8_t version;
1008: u_int8_t command;
1009: u_int8_t reserved;
1010: u_int8_t atyp;
1011: } s5_req, s5_rsp;
1012: u_int16_t dest_port;
1013: u_char *p, dest_addr[255+1];
1.217 djm 1014: u_int have, i, found, nmethods, addrlen, af;
1.193 markus 1015:
1016: debug2("channel %d: decode socks5", c->self);
1017: p = buffer_ptr(&c->input);
1018: if (p[0] != 0x05)
1019: return -1;
1020: have = buffer_len(&c->input);
1021: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1022: /* format: ver | nmethods | methods */
1.198 djm 1023: if (have < 2)
1.193 markus 1024: return 0;
1025: nmethods = p[1];
1026: if (have < nmethods + 2)
1027: return 0;
1028: /* look for method: "NO AUTHENTICATION REQUIRED" */
1029: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1030: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1031: found = 1;
1032: break;
1033: }
1034: }
1035: if (!found) {
1036: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1037: c->self);
1038: return -1;
1039: }
1040: buffer_consume(&c->input, nmethods + 2);
1041: buffer_put_char(&c->output, 0x05); /* version */
1042: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1043: FD_SET(c->sock, writeset);
1044: c->flags |= SSH_SOCKS5_AUTHDONE;
1045: debug2("channel %d: socks5 auth done", c->self);
1046: return 0; /* need more */
1047: }
1048: debug2("channel %d: socks5 post auth", c->self);
1049: if (have < sizeof(s5_req)+1)
1050: return 0; /* need more */
1051: memcpy((char *)&s5_req, p, sizeof(s5_req));
1052: if (s5_req.version != 0x05 ||
1053: s5_req.command != SSH_SOCKS5_CONNECT ||
1054: s5_req.reserved != 0x00) {
1.194 markus 1055: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1056: return -1;
1057: }
1.213 deraadt 1058: switch (s5_req.atyp){
1.193 markus 1059: case SSH_SOCKS5_IPV4:
1060: addrlen = 4;
1061: af = AF_INET;
1062: break;
1063: case SSH_SOCKS5_DOMAIN:
1064: addrlen = p[sizeof(s5_req)];
1065: af = -1;
1066: break;
1067: case SSH_SOCKS5_IPV6:
1068: addrlen = 16;
1069: af = AF_INET6;
1070: break;
1071: default:
1.194 markus 1072: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1073: return -1;
1074: }
1075: if (have < 4 + addrlen + 2)
1076: return 0;
1077: buffer_consume(&c->input, sizeof(s5_req));
1078: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1079: buffer_consume(&c->input, 1); /* host string length */
1080: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1081: buffer_get(&c->input, (char *)&dest_port, 2);
1082: dest_addr[addrlen] = '\0';
1083: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1084: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1085: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1086: return -1;
1087: c->host_port = ntohs(dest_port);
1.198 djm 1088:
1.194 markus 1089: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1090: c->self, c->path, c->host_port, s5_req.command);
1091:
1092: s5_rsp.version = 0x05;
1093: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1094: s5_rsp.reserved = 0; /* ignored */
1095: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1096: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1097: dest_port = 0; /* ignored */
1098:
1099: buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
1100: buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
1101: buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
1102: return 1;
1103: }
1104:
1.104 markus 1105: /* dynamic port forwarding */
1.127 itojun 1106: static void
1.237 deraadt 1107: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1108: {
1109: u_char *p;
1.217 djm 1110: u_int have;
1111: int ret;
1.103 markus 1112:
1.104 markus 1113: have = buffer_len(&c->input);
1.137 markus 1114: c->delayed = 0;
1.104 markus 1115: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1116: /* buffer_dump(&c->input); */
1.104 markus 1117: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1118: if (have < 3) {
1.104 markus 1119: /* need more */
1120: FD_SET(c->sock, readset);
1121: return;
1122: }
1123: /* try to guess the protocol */
1124: p = buffer_ptr(&c->input);
1125: switch (p[0]) {
1126: case 0x04:
1127: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1128: break;
1129: case 0x05:
1130: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1131: break;
1132: default:
1133: ret = -1;
1134: break;
1135: }
1136: if (ret < 0) {
1.113 markus 1137: chan_mark_dead(c);
1.104 markus 1138: } else if (ret == 0) {
1139: debug2("channel %d: pre_dynamic: need more", c->self);
1140: /* need more */
1141: FD_SET(c->sock, readset);
1142: } else {
1143: /* switch to the next state */
1144: c->type = SSH_CHANNEL_OPENING;
1145: port_open_helper(c, "direct-tcpip");
1146: }
1.103 markus 1147: }
1148:
1.41 markus 1149: /* This is our fake X11 server socket. */
1.127 itojun 1150: static void
1.237 deraadt 1151: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1152: {
1.113 markus 1153: Channel *nc;
1.41 markus 1154: struct sockaddr addr;
1.162 stevesk 1155: int newsock;
1.41 markus 1156: socklen_t addrlen;
1.85 markus 1157: char buf[16384], *remote_ipaddr;
1.51 markus 1158: int remote_port;
1.25 markus 1159:
1.41 markus 1160: if (FD_ISSET(c->sock, readset)) {
1161: debug("X11 connection requested.");
1162: addrlen = sizeof(addr);
1163: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1164: if (c->single_connection) {
1.194 markus 1165: debug2("single_connection: closing X11 listener.");
1.149 markus 1166: channel_close_fd(&c->sock);
1167: chan_mark_dead(c);
1168: }
1.41 markus 1169: if (newsock < 0) {
1170: error("accept: %.100s", strerror(errno));
1171: return;
1172: }
1.162 stevesk 1173: set_nodelay(newsock);
1.85 markus 1174: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1175: remote_port = get_peer_port(newsock);
1.41 markus 1176: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1177: remote_ipaddr, remote_port);
1.51 markus 1178:
1.113 markus 1179: nc = channel_new("accepted x11 socket",
1.51 markus 1180: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1181: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1182: if (compat20) {
1183: packet_start(SSH2_MSG_CHANNEL_OPEN);
1184: packet_put_cstring("x11");
1.113 markus 1185: packet_put_int(nc->self);
1.149 markus 1186: packet_put_int(nc->local_window_max);
1187: packet_put_int(nc->local_maxpacket);
1.85 markus 1188: /* originator ipaddr and port */
1189: packet_put_cstring(remote_ipaddr);
1.57 markus 1190: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1191: debug2("ssh2 x11 bug compat mode");
1.57 markus 1192: } else {
1193: packet_put_int(remote_port);
1194: }
1.51 markus 1195: packet_send();
1196: } else {
1197: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1198: packet_put_int(nc->self);
1.121 markus 1199: if (packet_get_protocol_flags() &
1200: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1201: packet_put_cstring(buf);
1.51 markus 1202: packet_send();
1203: }
1.85 markus 1204: xfree(remote_ipaddr);
1.41 markus 1205: }
1206: }
1.25 markus 1207:
1.127 itojun 1208: static void
1.103 markus 1209: port_open_helper(Channel *c, char *rtype)
1210: {
1211: int direct;
1212: char buf[1024];
1213: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1214: int remote_port = get_peer_port(c->sock);
1.103 markus 1215:
1216: direct = (strcmp(rtype, "direct-tcpip") == 0);
1217:
1218: snprintf(buf, sizeof buf,
1219: "%s: listening port %d for %.100s port %d, "
1220: "connect from %.200s port %d",
1221: rtype, c->listening_port, c->path, c->host_port,
1222: remote_ipaddr, remote_port);
1223:
1224: xfree(c->remote_name);
1225: c->remote_name = xstrdup(buf);
1226:
1227: if (compat20) {
1228: packet_start(SSH2_MSG_CHANNEL_OPEN);
1229: packet_put_cstring(rtype);
1230: packet_put_int(c->self);
1231: packet_put_int(c->local_window_max);
1232: packet_put_int(c->local_maxpacket);
1233: if (direct) {
1234: /* target host, port */
1235: packet_put_cstring(c->path);
1236: packet_put_int(c->host_port);
1237: } else {
1238: /* listen address, port */
1239: packet_put_cstring(c->path);
1240: packet_put_int(c->listening_port);
1241: }
1242: /* originator host and port */
1243: packet_put_cstring(remote_ipaddr);
1.216 markus 1244: packet_put_int((u_int)remote_port);
1.103 markus 1245: packet_send();
1246: } else {
1247: packet_start(SSH_MSG_PORT_OPEN);
1248: packet_put_int(c->self);
1249: packet_put_cstring(c->path);
1250: packet_put_int(c->host_port);
1.121 markus 1251: if (packet_get_protocol_flags() &
1252: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1253: packet_put_cstring(c->remote_name);
1254: packet_send();
1255: }
1256: xfree(remote_ipaddr);
1257: }
1258:
1.226 djm 1259: static void
1260: channel_set_reuseaddr(int fd)
1261: {
1262: int on = 1;
1263:
1264: /*
1265: * Set socket options.
1266: * Allow local port reuse in TIME_WAIT.
1267: */
1268: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1269: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1270: }
1271:
1.41 markus 1272: /*
1273: * This socket is listening for connections to a forwarded TCP/IP port.
1274: */
1.127 itojun 1275: static void
1.237 deraadt 1276: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1277: {
1.103 markus 1278: Channel *nc;
1.41 markus 1279: struct sockaddr addr;
1.113 markus 1280: int newsock, nextstate;
1.41 markus 1281: socklen_t addrlen;
1.103 markus 1282: char *rtype;
1.73 markus 1283:
1.41 markus 1284: if (FD_ISSET(c->sock, readset)) {
1285: debug("Connection to port %d forwarding "
1286: "to %.100s port %d requested.",
1287: c->listening_port, c->path, c->host_port);
1.103 markus 1288:
1.137 markus 1289: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1290: nextstate = SSH_CHANNEL_OPENING;
1291: rtype = "forwarded-tcpip";
1292: } else {
1293: if (c->host_port == 0) {
1294: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1295: rtype = "dynamic-tcpip";
1.137 markus 1296: } else {
1297: nextstate = SSH_CHANNEL_OPENING;
1298: rtype = "direct-tcpip";
1299: }
1300: }
1.103 markus 1301:
1.41 markus 1302: addrlen = sizeof(addr);
1303: newsock = accept(c->sock, &addr, &addrlen);
1304: if (newsock < 0) {
1305: error("accept: %.100s", strerror(errno));
1306: return;
1307: }
1.169 stevesk 1308: set_nodelay(newsock);
1.190 markus 1309: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1310: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1311: nc->listening_port = c->listening_port;
1312: nc->host_port = c->host_port;
1313: strlcpy(nc->path, c->path, sizeof(nc->path));
1314:
1.137 markus 1315: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1316: /*
1317: * do not call the channel_post handler until
1318: * this flag has been reset by a pre-handler.
1319: * otherwise the FD_ISSET calls might overflow
1320: */
1321: nc->delayed = 1;
1322: } else {
1.103 markus 1323: port_open_helper(nc, rtype);
1.137 markus 1324: }
1.41 markus 1325: }
1326: }
1.25 markus 1327:
1.41 markus 1328: /*
1329: * This is the authentication agent socket listening for connections from
1330: * clients.
1331: */
1.127 itojun 1332: static void
1.237 deraadt 1333: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1334: {
1.113 markus 1335: Channel *nc;
1336: int newsock;
1.41 markus 1337: struct sockaddr addr;
1338: socklen_t addrlen;
1.25 markus 1339:
1.41 markus 1340: if (FD_ISSET(c->sock, readset)) {
1341: addrlen = sizeof(addr);
1342: newsock = accept(c->sock, &addr, &addrlen);
1343: if (newsock < 0) {
1344: error("accept from auth socket: %.100s", strerror(errno));
1345: return;
1346: }
1.113 markus 1347: nc = channel_new("accepted auth socket",
1.73 markus 1348: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1349: c->local_window_max, c->local_maxpacket,
1.190 markus 1350: 0, "accepted auth socket", 1);
1.73 markus 1351: if (compat20) {
1352: packet_start(SSH2_MSG_CHANNEL_OPEN);
1353: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1354: packet_put_int(nc->self);
1.73 markus 1355: packet_put_int(c->local_window_max);
1356: packet_put_int(c->local_maxpacket);
1357: } else {
1358: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1359: packet_put_int(nc->self);
1.73 markus 1360: }
1.41 markus 1361: packet_send();
1362: }
1363: }
1.25 markus 1364:
1.127 itojun 1365: static void
1.237 deraadt 1366: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1367: {
1.114 markus 1368: int err = 0;
1.129 stevesk 1369: socklen_t sz = sizeof(err);
1.114 markus 1370:
1.75 markus 1371: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1372: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1373: err = errno;
1374: error("getsockopt SO_ERROR failed");
1375: }
1376: if (err == 0) {
1377: debug("channel %d: connected", c->self);
1378: c->type = SSH_CHANNEL_OPEN;
1379: if (compat20) {
1380: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1381: packet_put_int(c->remote_id);
1382: packet_put_int(c->self);
1383: packet_put_int(c->local_window);
1384: packet_put_int(c->local_maxpacket);
1385: } else {
1386: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1387: packet_put_int(c->remote_id);
1388: packet_put_int(c->self);
1389: }
1.75 markus 1390: } else {
1.114 markus 1391: debug("channel %d: not connected: %s",
1392: c->self, strerror(err));
1393: if (compat20) {
1394: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1395: packet_put_int(c->remote_id);
1396: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1397: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1398: packet_put_cstring(strerror(err));
1399: packet_put_cstring("");
1400: }
1.75 markus 1401: } else {
1.114 markus 1402: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1403: packet_put_int(c->remote_id);
1.75 markus 1404: }
1.114 markus 1405: chan_mark_dead(c);
1.75 markus 1406: }
1.114 markus 1407: packet_send();
1.75 markus 1408: }
1409: }
1410:
1.127 itojun 1411: static int
1.237 deraadt 1412: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1413: {
1.214 markus 1414: char buf[CHAN_RBUF];
1.41 markus 1415: int len;
1.25 markus 1416:
1.118 markus 1417: if (c->rfd != -1 &&
1.41 markus 1418: FD_ISSET(c->rfd, readset)) {
1419: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1420: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1421: return 1;
1.41 markus 1422: if (len <= 0) {
1.194 markus 1423: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1424: c->self, c->rfd, len);
1.104 markus 1425: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1426: debug2("channel %d: not open", c->self);
1.113 markus 1427: chan_mark_dead(c);
1.103 markus 1428: return -1;
1.104 markus 1429: } else if (compat13) {
1.158 markus 1430: buffer_clear(&c->output);
1.41 markus 1431: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1432: debug2("channel %d: input draining.", c->self);
1.25 markus 1433: } else {
1.41 markus 1434: chan_read_failed(c);
1.25 markus 1435: }
1.41 markus 1436: return -1;
1437: }
1.143 deraadt 1438: if (c->input_filter != NULL) {
1.66 markus 1439: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1440: debug2("channel %d: filter stops", c->self);
1.65 markus 1441: chan_read_failed(c);
1442: }
1.228 reyk 1443: } else if (c->datagram) {
1444: buffer_put_string(&c->input, buf, len);
1.65 markus 1445: } else {
1446: buffer_append(&c->input, buf, len);
1447: }
1.41 markus 1448: }
1449: return 1;
1450: }
1.241 deraadt 1451:
1.127 itojun 1452: static int
1.237 deraadt 1453: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1454: {
1.95 markus 1455: struct termios tio;
1.231 reyk 1456: u_char *data = NULL, *buf;
1.134 markus 1457: u_int dlen;
1.41 markus 1458: int len;
1.25 markus 1459:
1.41 markus 1460: /* Send buffered output data to the socket. */
1.118 markus 1461: if (c->wfd != -1 &&
1.41 markus 1462: FD_ISSET(c->wfd, writeset) &&
1463: buffer_len(&c->output) > 0) {
1.231 reyk 1464: if (c->output_filter != NULL) {
1465: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1466: debug2("channel %d: filter stops", c->self);
1.232 reyk 1467: if (c->type != SSH_CHANNEL_OPEN)
1468: chan_mark_dead(c);
1469: else
1470: chan_write_failed(c);
1471: return -1;
1.231 reyk 1472: }
1473: } else if (c->datagram) {
1474: buf = data = buffer_get_string(&c->output, &dlen);
1475: } else {
1476: buf = data = buffer_ptr(&c->output);
1477: dlen = buffer_len(&c->output);
1478: }
1479:
1.228 reyk 1480: if (c->datagram) {
1481: /* ignore truncated writes, datagrams might get lost */
1482: c->local_consumed += dlen + 4;
1.231 reyk 1483: len = write(c->wfd, buf, dlen);
1.228 reyk 1484: xfree(data);
1485: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1486: return 1;
1487: if (len <= 0) {
1488: if (c->type != SSH_CHANNEL_OPEN)
1489: chan_mark_dead(c);
1490: else
1491: chan_write_failed(c);
1492: return -1;
1493: }
1494: return 1;
1495: }
1.231 reyk 1496:
1497: len = write(c->wfd, buf, dlen);
1.53 markus 1498: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1499: return 1;
1.41 markus 1500: if (len <= 0) {
1.104 markus 1501: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1502: debug2("channel %d: not open", c->self);
1.113 markus 1503: chan_mark_dead(c);
1.104 markus 1504: return -1;
1505: } else if (compat13) {
1.158 markus 1506: buffer_clear(&c->output);
1.194 markus 1507: debug2("channel %d: input draining.", c->self);
1.41 markus 1508: c->type = SSH_CHANNEL_INPUT_DRAINING;
1509: } else {
1510: chan_write_failed(c);
1511: }
1512: return -1;
1.91 markus 1513: }
1.231 reyk 1514: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1515: if (tcgetattr(c->wfd, &tio) == 0 &&
1516: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1517: /*
1518: * Simulate echo to reduce the impact of
1.96 markus 1519: * traffic analysis. We need to match the
1.95 markus 1520: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1521: * (4 byte channel id + buf)
1.91 markus 1522: */
1.95 markus 1523: packet_send_ignore(4 + len);
1.91 markus 1524: packet_send();
1525: }
1.25 markus 1526: }
1.41 markus 1527: buffer_consume(&c->output, len);
1.44 markus 1528: if (compat20 && len > 0) {
1529: c->local_consumed += len;
1530: }
1531: }
1532: return 1;
1533: }
1.241 deraadt 1534:
1.127 itojun 1535: static int
1.237 deraadt 1536: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1537: {
1.214 markus 1538: char buf[CHAN_RBUF];
1.44 markus 1539: int len;
1540:
1.45 markus 1541: /** XXX handle drain efd, too */
1.44 markus 1542: if (c->efd != -1) {
1543: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1544: FD_ISSET(c->efd, writeset) &&
1545: buffer_len(&c->extended) > 0) {
1546: len = write(c->efd, buffer_ptr(&c->extended),
1547: buffer_len(&c->extended));
1.70 markus 1548: debug2("channel %d: written %d to efd %d",
1.44 markus 1549: c->self, len, c->efd);
1.93 markus 1550: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1551: return 1;
1552: if (len <= 0) {
1553: debug2("channel %d: closing write-efd %d",
1554: c->self, c->efd);
1.132 markus 1555: channel_close_fd(&c->efd);
1.93 markus 1556: } else {
1.44 markus 1557: buffer_consume(&c->extended, len);
1558: c->local_consumed += len;
1559: }
1560: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1561: FD_ISSET(c->efd, readset)) {
1562: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1563: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1564: c->self, len, c->efd);
1.93 markus 1565: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1566: return 1;
1567: if (len <= 0) {
1568: debug2("channel %d: closing read-efd %d",
1.45 markus 1569: c->self, c->efd);
1.132 markus 1570: channel_close_fd(&c->efd);
1.93 markus 1571: } else {
1.44 markus 1572: buffer_append(&c->extended, buf, len);
1.93 markus 1573: }
1.44 markus 1574: }
1575: }
1576: return 1;
1577: }
1.241 deraadt 1578:
1.127 itojun 1579: static int
1.237 deraadt 1580: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1581: {
1582: char buf[16];
1583: int len;
1584:
1585: /* Monitor control fd to detect if the slave client exits */
1586: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1587: len = read(c->ctl_fd, buf, sizeof(buf));
1588: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1589: return 1;
1590: if (len <= 0) {
1591: debug2("channel %d: ctl read<=0", c->self);
1592: if (c->type != SSH_CHANNEL_OPEN) {
1593: debug2("channel %d: not open", c->self);
1594: chan_mark_dead(c);
1595: return -1;
1596: } else {
1597: chan_read_failed(c);
1598: chan_write_failed(c);
1599: }
1600: return -1;
1601: } else
1602: fatal("%s: unexpected data on ctl fd", __func__);
1603: }
1604: return 1;
1605: }
1.241 deraadt 1606:
1.204 djm 1607: static int
1.93 markus 1608: channel_check_window(Channel *c)
1.44 markus 1609: {
1.104 markus 1610: if (c->type == SSH_CHANNEL_OPEN &&
1611: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1612: c->local_window < c->local_window_max/2 &&
1613: c->local_consumed > 0) {
1614: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1615: packet_put_int(c->remote_id);
1616: packet_put_int(c->local_consumed);
1617: packet_send();
1.70 markus 1618: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1619: c->self, c->local_window,
1620: c->local_consumed);
1621: c->local_window += c->local_consumed;
1622: c->local_consumed = 0;
1.1 deraadt 1623: }
1.41 markus 1624: return 1;
1.1 deraadt 1625: }
1626:
1.127 itojun 1627: static void
1.237 deraadt 1628: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1629: {
1.137 markus 1630: if (c->delayed)
1631: return;
1.41 markus 1632: channel_handle_rfd(c, readset, writeset);
1633: channel_handle_wfd(c, readset, writeset);
1.157 markus 1634: if (!compat20)
1.137 markus 1635: return;
1.44 markus 1636: channel_handle_efd(c, readset, writeset);
1.204 djm 1637: channel_handle_ctl(c, readset, writeset);
1.93 markus 1638: channel_check_window(c);
1.44 markus 1639: }
1640:
1.127 itojun 1641: static void
1.237 deraadt 1642: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1643: {
1.41 markus 1644: int len;
1.180 deraadt 1645:
1.41 markus 1646: /* Send buffered output data to the socket. */
1647: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1648: len = write(c->sock, buffer_ptr(&c->output),
1649: buffer_len(&c->output));
1650: if (len <= 0)
1.158 markus 1651: buffer_clear(&c->output);
1.41 markus 1652: else
1653: buffer_consume(&c->output, len);
1654: }
1655: }
1.25 markus 1656:
1.127 itojun 1657: static void
1.44 markus 1658: channel_handler_init_20(void)
1659: {
1.157 markus 1660: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1661: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1662: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1663: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1664: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1665: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1666: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1667: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1668:
1.157 markus 1669: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1670: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1671: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1672: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1673: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1674: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1675: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1676: }
1677:
1.127 itojun 1678: static void
1.41 markus 1679: channel_handler_init_13(void)
1680: {
1681: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1682: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1683: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1684: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1685: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1686: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1687: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1688: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1689: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1690:
1.157 markus 1691: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1692: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1693: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1694: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1695: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1696: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1697: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1698: }
1.25 markus 1699:
1.127 itojun 1700: static void
1.41 markus 1701: channel_handler_init_15(void)
1702: {
1.157 markus 1703: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1704: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1705: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1706: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1707: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1708: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1709: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1710:
1.41 markus 1711: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1712: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1713: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1714: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1715: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1716: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1717: }
1.27 markus 1718:
1.127 itojun 1719: static void
1.41 markus 1720: channel_handler_init(void)
1721: {
1722: int i;
1.180 deraadt 1723:
1.148 deraadt 1724: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1725: channel_pre[i] = NULL;
1726: channel_post[i] = NULL;
1727: }
1.44 markus 1728: if (compat20)
1729: channel_handler_init_20();
1730: else if (compat13)
1.41 markus 1731: channel_handler_init_13();
1732: else
1733: channel_handler_init_15();
1734: }
1.25 markus 1735:
1.140 markus 1736: /* gc dead channels */
1737: static void
1738: channel_garbage_collect(Channel *c)
1739: {
1740: if (c == NULL)
1741: return;
1742: if (c->detach_user != NULL) {
1.225 djm 1743: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1744: return;
1.194 markus 1745: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1746: c->detach_user(c->self, NULL);
1747: /* if we still have a callback */
1748: if (c->detach_user != NULL)
1749: return;
1.194 markus 1750: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1751: }
1752: if (!chan_is_dead(c, 1))
1753: return;
1.194 markus 1754: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1755: channel_free(c);
1756: }
1757:
1.127 itojun 1758: static void
1.237 deraadt 1759: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1760: {
1761: static int did_init = 0;
1.209 avsm 1762: u_int i;
1.41 markus 1763: Channel *c;
1.25 markus 1764:
1.41 markus 1765: if (!did_init) {
1766: channel_handler_init();
1767: did_init = 1;
1768: }
1769: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1770: c = channels[i];
1771: if (c == NULL)
1.41 markus 1772: continue;
1.118 markus 1773: if (ftab[c->type] != NULL)
1774: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1775: channel_garbage_collect(c);
1.1 deraadt 1776: }
1777: }
1778:
1.121 markus 1779: /*
1780: * Allocate/update select bitmasks and add any bits relevant to channels in
1781: * select bitmasks.
1782: */
1.49 markus 1783: void
1.100 markus 1784: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1785: u_int *nallocp, int rekeying)
1.41 markus 1786: {
1.243 djm 1787: u_int n, sz, nfdset;
1.84 markus 1788:
1789: n = MAX(*maxfdp, channel_max_fd);
1790:
1.243 djm 1791: nfdset = howmany(n+1, NFDBITS);
1792: /* Explicitly test here, because xrealloc isn't always called */
1793: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1794: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1795: sz = nfdset * sizeof(fd_mask);
1796:
1.132 markus 1797: /* perhaps check sz < nalloc/2 and shrink? */
1798: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1799: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1800: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1801: *nallocp = sz;
1.84 markus 1802: }
1.132 markus 1803: *maxfdp = n;
1.84 markus 1804: memset(*readsetp, 0, sz);
1805: memset(*writesetp, 0, sz);
1806:
1.100 markus 1807: if (!rekeying)
1808: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1809: }
1810:
1.121 markus 1811: /*
1812: * After select, perform any appropriate operations for channels which have
1813: * events pending.
1814: */
1.49 markus 1815: void
1.237 deraadt 1816: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1817: {
1818: channel_handler(channel_post, readset, writeset);
1819: }
1820:
1.121 markus 1821:
1.84 markus 1822: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1823: void
1.142 itojun 1824: channel_output_poll(void)
1.1 deraadt 1825: {
1.41 markus 1826: Channel *c;
1.209 avsm 1827: u_int i, len;
1.1 deraadt 1828:
1.25 markus 1829: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1830: c = channels[i];
1831: if (c == NULL)
1832: continue;
1.37 markus 1833:
1.121 markus 1834: /*
1835: * We are only interested in channels that can have buffered
1836: * incoming data.
1837: */
1.37 markus 1838: if (compat13) {
1.41 markus 1839: if (c->type != SSH_CHANNEL_OPEN &&
1840: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1841: continue;
1842: } else {
1.41 markus 1843: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1844: continue;
1845: }
1.46 markus 1846: if (compat20 &&
1847: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1848: /* XXX is this true? */
1.140 markus 1849: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1850: continue;
1851: }
1.25 markus 1852:
1853: /* Get the amount of buffered data for this channel. */
1.93 markus 1854: if ((c->istate == CHAN_INPUT_OPEN ||
1855: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1856: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1857: if (c->datagram) {
1858: if (len > 0) {
1859: u_char *data;
1860: u_int dlen;
1861:
1862: data = buffer_get_string(&c->input,
1863: &dlen);
1864: packet_start(SSH2_MSG_CHANNEL_DATA);
1865: packet_put_int(c->remote_id);
1866: packet_put_string(data, dlen);
1867: packet_send();
1868: c->remote_window -= dlen + 4;
1869: xfree(data);
1870: }
1871: continue;
1872: }
1.121 markus 1873: /*
1874: * Send some data for the other side over the secure
1875: * connection.
1876: */
1.44 markus 1877: if (compat20) {
1878: if (len > c->remote_window)
1879: len = c->remote_window;
1880: if (len > c->remote_maxpacket)
1881: len = c->remote_maxpacket;
1.25 markus 1882: } else {
1.44 markus 1883: if (packet_is_interactive()) {
1884: if (len > 1024)
1885: len = 512;
1886: } else {
1887: /* Keep the packets at reasonable size. */
1888: if (len > packet_get_maxsize()/2)
1889: len = packet_get_maxsize()/2;
1890: }
1.25 markus 1891: }
1.41 markus 1892: if (len > 0) {
1.44 markus 1893: packet_start(compat20 ?
1894: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1895: packet_put_int(c->remote_id);
1896: packet_put_string(buffer_ptr(&c->input), len);
1897: packet_send();
1898: buffer_consume(&c->input, len);
1899: c->remote_window -= len;
1900: }
1901: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1902: if (compat13)
1903: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1904: /*
1905: * input-buffer is empty and read-socket shutdown:
1.172 markus 1906: * tell peer, that we will not send more data: send IEOF.
1907: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1908: */
1.172 markus 1909: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1910: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1911: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1912: else
1913: chan_ibuf_empty(c);
1.25 markus 1914: }
1.44 markus 1915: /* Send extended data, i.e. stderr */
1916: if (compat20 &&
1.172 markus 1917: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1918: c->remote_window > 0 &&
1919: (len = buffer_len(&c->extended)) > 0 &&
1920: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1921: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1922: c->self, c->remote_window, buffer_len(&c->extended),
1923: c->extended_usage);
1.44 markus 1924: if (len > c->remote_window)
1925: len = c->remote_window;
1926: if (len > c->remote_maxpacket)
1927: len = c->remote_maxpacket;
1928: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1929: packet_put_int(c->remote_id);
1930: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1931: packet_put_string(buffer_ptr(&c->extended), len);
1932: packet_send();
1933: buffer_consume(&c->extended, len);
1934: c->remote_window -= len;
1.93 markus 1935: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1936: }
1.25 markus 1937: }
1.1 deraadt 1938: }
1939:
1.121 markus 1940:
1941: /* -- protocol input */
1.49 markus 1942: void
1.154 markus 1943: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1944: {
1.37 markus 1945: int id;
1.25 markus 1946: char *data;
1.77 markus 1947: u_int data_len;
1.41 markus 1948: Channel *c;
1.25 markus 1949:
1950: /* Get the channel number and verify it. */
1.37 markus 1951: id = packet_get_int();
1.41 markus 1952: c = channel_lookup(id);
1953: if (c == NULL)
1.37 markus 1954: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1955:
1956: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1957: if (c->type != SSH_CHANNEL_OPEN &&
1958: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1959: return;
1960:
1.25 markus 1961: /* Get the data. */
1962: data = packet_get_string(&data_len);
1.200 markus 1963:
1964: /*
1965: * Ignore data for protocol > 1.3 if output end is no longer open.
1966: * For protocol 2 the sending side is reducing its window as it sends
1967: * data, so we must 'fake' consumption of the data in order to ensure
1968: * that window updates are sent back. Otherwise the connection might
1969: * deadlock.
1970: */
1971: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
1972: if (compat20) {
1973: c->local_window -= data_len;
1974: c->local_consumed += data_len;
1975: }
1976: xfree(data);
1977: return;
1978: }
1.41 markus 1979:
1.143 deraadt 1980: if (compat20) {
1.44 markus 1981: if (data_len > c->local_maxpacket) {
1.188 itojun 1982: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 1983: c->self, data_len, c->local_maxpacket);
1984: }
1985: if (data_len > c->local_window) {
1.188 itojun 1986: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 1987: c->self, data_len, c->local_window);
1988: xfree(data);
1989: return;
1990: }
1991: c->local_window -= data_len;
1992: }
1.152 markus 1993: packet_check_eom();
1.228 reyk 1994: if (c->datagram)
1995: buffer_put_string(&c->output, data, data_len);
1996: else
1997: buffer_append(&c->output, data, data_len);
1.25 markus 1998: xfree(data);
1.1 deraadt 1999: }
1.121 markus 2000:
1.49 markus 2001: void
1.154 markus 2002: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2003: {
2004: int id;
2005: char *data;
1.177 markus 2006: u_int data_len, tcode;
1.44 markus 2007: Channel *c;
2008:
2009: /* Get the channel number and verify it. */
2010: id = packet_get_int();
2011: c = channel_lookup(id);
2012:
2013: if (c == NULL)
2014: packet_disconnect("Received extended_data for bad channel %d.", id);
2015: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2016: logit("channel %d: ext data for non open", id);
1.44 markus 2017: return;
1.172 markus 2018: }
2019: if (c->flags & CHAN_EOF_RCVD) {
2020: if (datafellows & SSH_BUG_EXTEOF)
2021: debug("channel %d: accepting ext data after eof", id);
2022: else
2023: packet_disconnect("Received extended_data after EOF "
2024: "on channel %d.", id);
1.44 markus 2025: }
2026: tcode = packet_get_int();
2027: if (c->efd == -1 ||
2028: c->extended_usage != CHAN_EXTENDED_WRITE ||
2029: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2030: logit("channel %d: bad ext data", c->self);
1.44 markus 2031: return;
2032: }
2033: data = packet_get_string(&data_len);
1.152 markus 2034: packet_check_eom();
1.44 markus 2035: if (data_len > c->local_window) {
1.188 itojun 2036: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2037: c->self, data_len, c->local_window);
2038: xfree(data);
2039: return;
2040: }
1.70 markus 2041: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2042: c->local_window -= data_len;
2043: buffer_append(&c->extended, data, data_len);
2044: xfree(data);
2045: }
2046:
1.49 markus 2047: void
1.154 markus 2048: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2049: {
2050: int id;
2051: Channel *c;
2052:
2053: id = packet_get_int();
1.152 markus 2054: packet_check_eom();
1.41 markus 2055: c = channel_lookup(id);
2056: if (c == NULL)
2057: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2058: chan_rcvd_ieof(c);
1.133 markus 2059:
2060: /* XXX force input close */
1.156 markus 2061: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2062: debug("channel %d: FORCE input drain", c->self);
2063: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2064: if (buffer_len(&c->input) == 0)
2065: chan_ibuf_empty(c);
1.133 markus 2066: }
2067:
1.41 markus 2068: }
1.1 deraadt 2069:
1.49 markus 2070: void
1.154 markus 2071: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2072: {
1.41 markus 2073: int id;
2074: Channel *c;
1.1 deraadt 2075:
1.41 markus 2076: id = packet_get_int();
1.152 markus 2077: packet_check_eom();
1.41 markus 2078: c = channel_lookup(id);
2079: if (c == NULL)
2080: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2081:
2082: /*
2083: * Send a confirmation that we have closed the channel and no more
2084: * data is coming for it.
2085: */
1.25 markus 2086: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2087: packet_put_int(c->remote_id);
1.25 markus 2088: packet_send();
2089:
1.27 markus 2090: /*
2091: * If the channel is in closed state, we have sent a close request,
2092: * and the other side will eventually respond with a confirmation.
2093: * Thus, we cannot free the channel here, because then there would be
2094: * no-one to receive the confirmation. The channel gets freed when
2095: * the confirmation arrives.
2096: */
1.41 markus 2097: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2098: /*
2099: * Not a closed channel - mark it as draining, which will
2100: * cause it to be freed later.
2101: */
1.158 markus 2102: buffer_clear(&c->input);
1.41 markus 2103: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2104: }
1.1 deraadt 2105: }
2106:
1.41 markus 2107: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 2108: void
1.154 markus 2109: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2110: {
2111: int id = packet_get_int();
2112: Channel *c = channel_lookup(id);
1.151 markus 2113:
1.152 markus 2114: packet_check_eom();
1.41 markus 2115: if (c == NULL)
2116: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2117: chan_rcvd_oclose(c);
2118: }
1.1 deraadt 2119:
1.49 markus 2120: void
1.154 markus 2121: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2122: {
1.41 markus 2123: int id = packet_get_int();
2124: Channel *c = channel_lookup(id);
1.1 deraadt 2125:
1.152 markus 2126: packet_check_eom();
1.41 markus 2127: if (c == NULL)
2128: packet_disconnect("Received close confirmation for "
2129: "out-of-range channel %d.", id);
2130: if (c->type != SSH_CHANNEL_CLOSED)
2131: packet_disconnect("Received close confirmation for "
2132: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2133: channel_free(c);
1.1 deraadt 2134: }
2135:
1.49 markus 2136: void
1.154 markus 2137: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2138: {
1.41 markus 2139: int id, remote_id;
2140: Channel *c;
1.1 deraadt 2141:
1.41 markus 2142: id = packet_get_int();
2143: c = channel_lookup(id);
1.25 markus 2144:
1.41 markus 2145: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2146: packet_disconnect("Received open confirmation for "
2147: "non-opening channel %d.", id);
2148: remote_id = packet_get_int();
1.27 markus 2149: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2150: c->remote_id = remote_id;
2151: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2152:
2153: if (compat20) {
2154: c->remote_window = packet_get_int();
2155: c->remote_maxpacket = packet_get_int();
1.165 markus 2156: if (c->confirm) {
1.70 markus 2157: debug2("callback start");
1.204 djm 2158: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2159: debug2("callback done");
1.44 markus 2160: }
1.194 markus 2161: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2162: c->remote_window, c->remote_maxpacket);
2163: }
1.152 markus 2164: packet_check_eom();
1.1 deraadt 2165: }
2166:
1.127 itojun 2167: static char *
1.114 markus 2168: reason2txt(int reason)
2169: {
1.143 deraadt 2170: switch (reason) {
1.114 markus 2171: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2172: return "administratively prohibited";
2173: case SSH2_OPEN_CONNECT_FAILED:
2174: return "connect failed";
2175: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2176: return "unknown channel type";
2177: case SSH2_OPEN_RESOURCE_SHORTAGE:
2178: return "resource shortage";
2179: }
1.117 stevesk 2180: return "unknown reason";
1.114 markus 2181: }
2182:
1.49 markus 2183: void
1.154 markus 2184: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2185: {
1.86 markus 2186: int id, reason;
2187: char *msg = NULL, *lang = NULL;
1.41 markus 2188: Channel *c;
2189:
2190: id = packet_get_int();
2191: c = channel_lookup(id);
1.25 markus 2192:
1.41 markus 2193: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2194: packet_disconnect("Received open failure for "
2195: "non-opening channel %d.", id);
1.44 markus 2196: if (compat20) {
1.86 markus 2197: reason = packet_get_int();
1.110 markus 2198: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2199: msg = packet_get_string(NULL);
2200: lang = packet_get_string(NULL);
2201: }
1.188 itojun 2202: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2203: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2204: if (msg != NULL)
2205: xfree(msg);
2206: if (lang != NULL)
2207: xfree(lang);
1.44 markus 2208: }
1.152 markus 2209: packet_check_eom();
1.25 markus 2210: /* Free the channel. This will also close the socket. */
1.113 markus 2211: channel_free(c);
1.44 markus 2212: }
2213:
1.121 markus 2214: void
1.154 markus 2215: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2216: {
2217: Channel *c;
1.178 markus 2218: int id;
2219: u_int adjust;
1.121 markus 2220:
2221: if (!compat20)
2222: return;
2223:
2224: /* Get the channel number and verify it. */
2225: id = packet_get_int();
2226: c = channel_lookup(id);
1.1 deraadt 2227:
1.229 markus 2228: if (c == NULL) {
2229: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2230: return;
2231: }
2232: adjust = packet_get_int();
1.152 markus 2233: packet_check_eom();
1.178 markus 2234: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2235: c->remote_window += adjust;
2236: }
1.1 deraadt 2237:
1.121 markus 2238: void
1.154 markus 2239: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2240: {
1.121 markus 2241: Channel *c = NULL;
2242: u_short host_port;
2243: char *host, *originator_string;
2244: int remote_id, sock = -1;
2245:
2246: remote_id = packet_get_int();
2247: host = packet_get_string(NULL);
2248: host_port = packet_get_int();
1.25 markus 2249:
1.121 markus 2250: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2251: originator_string = packet_get_string(NULL);
2252: } else {
2253: originator_string = xstrdup("unknown (remote did not supply name)");
2254: }
1.152 markus 2255: packet_check_eom();
1.121 markus 2256: sock = channel_connect_to(host, host_port);
2257: if (sock != -1) {
2258: c = channel_new("connected socket",
2259: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2260: originator_string, 1);
1.167 markus 2261: c->remote_id = remote_id;
1.25 markus 2262: }
1.190 markus 2263: xfree(originator_string);
1.121 markus 2264: if (c == NULL) {
2265: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2266: packet_put_int(remote_id);
2267: packet_send();
2268: }
2269: xfree(host);
1.1 deraadt 2270: }
2271:
1.121 markus 2272:
2273: /* -- tcp forwarding */
1.135 markus 2274:
2275: void
2276: channel_set_af(int af)
2277: {
2278: IPv4or6 = af;
2279: }
1.121 markus 2280:
1.160 markus 2281: static int
2282: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2283: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2284: {
1.113 markus 2285: Channel *c;
1.226 djm 2286: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2287: struct addrinfo hints, *ai, *aitop;
1.212 djm 2288: const char *host, *addr;
1.35 markus 2289: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2290:
1.160 markus 2291: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2292: listen_addr : host_to_connect;
1.212 djm 2293: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2294:
1.160 markus 2295: if (host == NULL) {
2296: error("No forward host name.");
1.218 markus 2297: return 0;
1.73 markus 2298: }
1.113 markus 2299: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2300: error("Forward host name too long.");
1.218 markus 2301: return 0;
1.87 markus 2302: }
1.25 markus 2303:
1.28 markus 2304: /*
1.212 djm 2305: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2306: * specified address or wildcard. On the client, a specified bind
2307: * address will always override gateway_ports. On the server, a
2308: * gateway_ports of 1 (``yes'') will override the client's
2309: * specification and force a wildcard bind, whereas a value of 2
2310: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2311: * asked for.
2312: *
2313: * Special-case listen_addrs are:
2314: *
2315: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2316: * "" (empty string), "*" -> wildcard v4/v6
2317: * "localhost" -> loopback v4/v6
2318: */
2319: addr = NULL;
2320: if (listen_addr == NULL) {
2321: /* No address specified: default to gateway_ports setting */
2322: if (gateway_ports)
2323: wildcard = 1;
2324: } else if (gateway_ports || is_client) {
2325: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2326: strcmp(listen_addr, "0.0.0.0") == 0) ||
2327: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2328: (!is_client && gateway_ports == 1))
2329: wildcard = 1;
2330: else if (strcmp(listen_addr, "localhost") != 0)
2331: addr = listen_addr;
2332: }
2333:
2334: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2335: type, wildcard, (addr == NULL) ? "NULL" : addr);
2336:
2337: /*
1.35 markus 2338: * getaddrinfo returns a loopback address if the hostname is
2339: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2340: */
1.35 markus 2341: memset(&hints, 0, sizeof(hints));
2342: hints.ai_family = IPv4or6;
1.212 djm 2343: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2344: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2345: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2346: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2347: if (addr == NULL) {
2348: /* This really shouldn't happen */
2349: packet_disconnect("getaddrinfo: fatal error: %s",
2350: gai_strerror(r));
2351: } else {
1.218 markus 2352: error("channel_setup_fwd_listener: "
1.212 djm 2353: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2354: }
1.218 markus 2355: return 0;
1.212 djm 2356: }
1.35 markus 2357:
2358: for (ai = aitop; ai; ai = ai->ai_next) {
2359: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2360: continue;
2361: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2362: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2363: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2364: continue;
2365: }
2366: /* Create a port to listen for the host. */
1.189 markus 2367: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2368: if (sock < 0) {
2369: /* this is no error since kernel may not support ipv6 */
2370: verbose("socket: %.100s", strerror(errno));
2371: continue;
2372: }
1.226 djm 2373:
2374: channel_set_reuseaddr(sock);
1.182 stevesk 2375:
1.35 markus 2376: debug("Local forwarding listening on %s port %s.", ntop, strport);
2377:
2378: /* Bind the socket to the address. */
2379: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2380: /* address can be in use ipv6 address is already bound */
2381: verbose("bind: %.100s", strerror(errno));
2382: close(sock);
2383: continue;
2384: }
2385: /* Start listening for connections on the socket. */
1.199 markus 2386: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2387: error("listen: %.100s", strerror(errno));
2388: close(sock);
2389: continue;
2390: }
2391: /* Allocate a channel number for the socket. */
1.121 markus 2392: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2393: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2394: 0, "port listener", 1);
1.113 markus 2395: strlcpy(c->path, host, sizeof(c->path));
2396: c->host_port = port_to_connect;
2397: c->listening_port = listen_port;
1.35 markus 2398: success = 1;
2399: }
2400: if (success == 0)
1.160 markus 2401: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2402: listen_port);
1.35 markus 2403: freeaddrinfo(aitop);
1.87 markus 2404: return success;
1.25 markus 2405: }
1.1 deraadt 2406:
1.202 djm 2407: int
2408: channel_cancel_rport_listener(const char *host, u_short port)
2409: {
1.209 avsm 2410: u_int i;
2411: int found = 0;
1.202 djm 2412:
1.213 deraadt 2413: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2414: Channel *c = channels[i];
2415:
2416: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2417: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2418: c->listening_port == port) {
1.210 djm 2419: debug2("%s: close channel %d", __func__, i);
1.202 djm 2420: channel_free(c);
2421: found = 1;
2422: }
2423: }
2424:
2425: return (found);
2426: }
2427:
1.160 markus 2428: /* protocol local port fwd, used by ssh (and sshd in v1) */
2429: int
1.212 djm 2430: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2431: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2432: {
2433: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2434: listen_host, listen_port, host_to_connect, port_to_connect,
2435: gateway_ports);
1.160 markus 2436: }
2437:
2438: /* protocol v2 remote port fwd, used by sshd */
2439: int
2440: channel_setup_remote_fwd_listener(const char *listen_address,
2441: u_short listen_port, int gateway_ports)
2442: {
2443: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2444: listen_address, listen_port, NULL, 0, gateway_ports);
2445: }
2446:
1.27 markus 2447: /*
2448: * Initiate forwarding of connections to port "port" on remote host through
2449: * the secure channel to host:port from local side.
2450: */
1.1 deraadt 2451:
1.49 markus 2452: void
1.212 djm 2453: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2454: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2455: {
1.153 markus 2456: int type, success = 0;
1.73 markus 2457:
1.25 markus 2458: /* Record locally that connection to this host/port is permitted. */
2459: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2460: fatal("channel_request_remote_forwarding: too many forwards");
2461:
2462: /* Send the forward request to the remote side. */
1.44 markus 2463: if (compat20) {
1.212 djm 2464: const char *address_to_bind;
2465: if (listen_host == NULL)
2466: address_to_bind = "localhost";
2467: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2468: address_to_bind = "";
2469: else
2470: address_to_bind = listen_host;
2471:
1.44 markus 2472: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2473: packet_put_cstring("tcpip-forward");
1.173 markus 2474: packet_put_char(1); /* boolean: want reply */
1.44 markus 2475: packet_put_cstring(address_to_bind);
2476: packet_put_int(listen_port);
1.73 markus 2477: packet_send();
2478: packet_write_wait();
2479: /* Assume that server accepts the request */
2480: success = 1;
1.44 markus 2481: } else {
2482: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2483: packet_put_int(listen_port);
2484: packet_put_cstring(host_to_connect);
1.44 markus 2485: packet_put_int(port_to_connect);
2486: packet_send();
2487: packet_write_wait();
1.73 markus 2488:
2489: /* Wait for response from the remote side. */
1.153 markus 2490: type = packet_read();
1.73 markus 2491: switch (type) {
2492: case SSH_SMSG_SUCCESS:
2493: success = 1;
2494: break;
2495: case SSH_SMSG_FAILURE:
1.188 itojun 2496: logit("Warning: Server denied remote port forwarding.");
1.73 markus 2497: break;
2498: default:
2499: /* Unknown packet */
2500: packet_disconnect("Protocol error for port forward request:"
2501: "received packet type %d.", type);
2502: }
2503: }
2504: if (success) {
2505: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2506: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2507: permitted_opens[num_permitted_opens].listen_port = listen_port;
2508: num_permitted_opens++;
1.44 markus 2509: }
1.1 deraadt 2510: }
2511:
1.27 markus 2512: /*
1.208 deraadt 2513: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2514: * local side.
2515: */
2516: void
1.212 djm 2517: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2518: {
2519: int i;
2520:
2521: if (!compat20)
2522: return;
2523:
2524: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2525: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2526: permitted_opens[i].listen_port == port)
2527: break;
2528: }
2529: if (i >= num_permitted_opens) {
2530: debug("%s: requested forward not found", __func__);
2531: return;
2532: }
2533: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2534: packet_put_cstring("cancel-tcpip-forward");
2535: packet_put_char(0);
1.212 djm 2536: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2537: packet_put_int(port);
2538: packet_send();
2539:
2540: permitted_opens[i].listen_port = 0;
2541: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2542: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2543: permitted_opens[i].host_to_connect = NULL;
2544: }
2545:
2546: /*
1.27 markus 2547: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2548: * listening for the port, and sends back a success reply (or disconnect
2549: * message if there was an error). This never returns if there was an error.
2550: */
1.49 markus 2551: void
1.56 markus 2552: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2553: {
1.31 markus 2554: u_short port, host_port;
1.25 markus 2555: char *hostname;
1.1 deraadt 2556:
1.25 markus 2557: /* Get arguments from the packet. */
2558: port = packet_get_int();
2559: hostname = packet_get_string(NULL);
2560: host_port = packet_get_int();
2561:
1.27 markus 2562: /*
2563: * Check that an unprivileged user is not trying to forward a
2564: * privileged port.
2565: */
1.25 markus 2566: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2567: packet_disconnect(
2568: "Requested forwarding of port %d but user is not root.",
2569: port);
2570: if (host_port == 0)
2571: packet_disconnect("Dynamic forwarding denied.");
2572:
1.73 markus 2573: /* Initiate forwarding */
1.212 djm 2574: channel_setup_local_fwd_listener(NULL, port, hostname,
2575: host_port, gateway_ports);
1.25 markus 2576:
2577: /* Free the argument string. */
2578: xfree(hostname);
1.1 deraadt 2579: }
2580:
1.99 markus 2581: /*
2582: * Permits opening to any host/port if permitted_opens[] is empty. This is
2583: * usually called by the server, because the user could connect to any port
2584: * anyway, and the server has no way to know but to trust the client anyway.
2585: */
2586: void
1.142 itojun 2587: channel_permit_all_opens(void)
1.99 markus 2588: {
2589: if (num_permitted_opens == 0)
2590: all_opens_permitted = 1;
2591: }
2592:
1.101 markus 2593: void
1.99 markus 2594: channel_add_permitted_opens(char *host, int port)
2595: {
2596: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2597: fatal("channel_request_remote_forwarding: too many forwards");
2598: debug("allow port forwarding to host %s port %d", host, port);
2599:
2600: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2601: permitted_opens[num_permitted_opens].port_to_connect = port;
2602: num_permitted_opens++;
2603:
2604: all_opens_permitted = 0;
2605: }
2606:
1.101 markus 2607: void
1.99 markus 2608: channel_clear_permitted_opens(void)
2609: {
2610: int i;
2611:
2612: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2613: if (permitted_opens[i].host_to_connect != NULL)
2614: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2615: num_permitted_opens = 0;
2616:
2617: }
2618:
2619: /* return socket to remote host, port */
1.127 itojun 2620: static int
1.99 markus 2621: connect_to(const char *host, u_short port)
1.41 markus 2622: {
2623: struct addrinfo hints, *ai, *aitop;
2624: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2625: int gaierr;
2626: int sock = -1;
2627:
2628: memset(&hints, 0, sizeof(hints));
2629: hints.ai_family = IPv4or6;
2630: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2631: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2632: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2633: error("connect_to %.100s: unknown host (%s)", host,
2634: gai_strerror(gaierr));
1.41 markus 2635: return -1;
2636: }
2637: for (ai = aitop; ai; ai = ai->ai_next) {
2638: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2639: continue;
2640: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2641: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2642: error("connect_to: getnameinfo failed");
1.41 markus 2643: continue;
2644: }
1.189 markus 2645: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2646: if (sock < 0) {
1.186 djm 2647: if (ai->ai_next == NULL)
2648: error("socket: %.100s", strerror(errno));
2649: else
2650: verbose("socket: %.100s", strerror(errno));
1.41 markus 2651: continue;
2652: }
1.205 djm 2653: if (set_nonblock(sock) == -1)
2654: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2655: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2656: errno != EINPROGRESS) {
1.99 markus 2657: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2658: strerror(errno));
2659: close(sock);
1.89 stevesk 2660: continue; /* fail -- try next */
1.41 markus 2661: }
2662: break; /* success */
2663:
2664: }
2665: freeaddrinfo(aitop);
2666: if (!ai) {
1.99 markus 2667: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2668: return -1;
2669: }
2670: /* success */
1.169 stevesk 2671: set_nodelay(sock);
1.41 markus 2672: return sock;
2673: }
1.99 markus 2674:
1.73 markus 2675: int
1.130 stevesk 2676: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2677: {
2678: int i;
1.99 markus 2679:
1.73 markus 2680: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2681: if (permitted_opens[i].host_to_connect != NULL &&
2682: permitted_opens[i].listen_port == listen_port)
1.99 markus 2683: return connect_to(
1.73 markus 2684: permitted_opens[i].host_to_connect,
2685: permitted_opens[i].port_to_connect);
1.74 markus 2686: error("WARNING: Server requests forwarding for unknown listen_port %d",
2687: listen_port);
1.73 markus 2688: return -1;
2689: }
2690:
1.99 markus 2691: /* Check if connecting to that port is permitted and connect. */
2692: int
2693: channel_connect_to(const char *host, u_short port)
2694: {
2695: int i, permit;
2696:
2697: permit = all_opens_permitted;
2698: if (!permit) {
2699: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2700: if (permitted_opens[i].host_to_connect != NULL &&
2701: permitted_opens[i].port_to_connect == port &&
1.99 markus 2702: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2703: permit = 1;
2704:
2705: }
2706: if (!permit) {
1.188 itojun 2707: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2708: "but the request was denied.", host, port);
2709: return -1;
2710: }
2711: return connect_to(host, port);
1.204 djm 2712: }
2713:
2714: void
2715: channel_send_window_changes(void)
2716: {
1.209 avsm 2717: u_int i;
1.204 djm 2718: struct winsize ws;
2719:
2720: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2721: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2722: channels[i]->type != SSH_CHANNEL_OPEN)
2723: continue;
2724: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2725: continue;
2726: channel_request_start(i, "window-change", 0);
1.238 deraadt 2727: packet_put_int((u_int)ws.ws_col);
2728: packet_put_int((u_int)ws.ws_row);
2729: packet_put_int((u_int)ws.ws_xpixel);
2730: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2731: packet_send();
2732: }
1.99 markus 2733: }
2734:
1.121 markus 2735: /* -- X11 forwarding */
1.1 deraadt 2736:
1.27 markus 2737: /*
2738: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2739: * Returns 0 and a suitable display number for the DISPLAY variable
2740: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2741: */
1.141 stevesk 2742: int
1.163 stevesk 2743: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2744: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2745: {
1.149 markus 2746: Channel *nc = NULL;
1.31 markus 2747: int display_number, sock;
2748: u_short port;
1.35 markus 2749: struct addrinfo hints, *ai, *aitop;
2750: char strport[NI_MAXSERV];
2751: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2752:
1.224 markus 2753: if (chanids == NULL)
2754: return -1;
2755:
1.33 markus 2756: for (display_number = x11_display_offset;
1.148 deraadt 2757: display_number < MAX_DISPLAYS;
2758: display_number++) {
1.25 markus 2759: port = 6000 + display_number;
1.35 markus 2760: memset(&hints, 0, sizeof(hints));
2761: hints.ai_family = IPv4or6;
1.163 stevesk 2762: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2763: hints.ai_socktype = SOCK_STREAM;
2764: snprintf(strport, sizeof strport, "%d", port);
2765: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2766: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2767: return -1;
1.25 markus 2768: }
1.35 markus 2769: for (ai = aitop; ai; ai = ai->ai_next) {
2770: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2771: continue;
1.189 markus 2772: sock = socket(ai->ai_family, ai->ai_socktype,
2773: ai->ai_protocol);
1.35 markus 2774: if (sock < 0) {
2775: error("socket: %.100s", strerror(errno));
1.203 markus 2776: freeaddrinfo(aitop);
1.141 stevesk 2777: return -1;
1.35 markus 2778: }
1.226 djm 2779: channel_set_reuseaddr(sock);
1.35 markus 2780: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2781: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2782: close(sock);
1.183 itojun 2783:
2784: if (ai->ai_next)
2785: continue;
2786:
1.35 markus 2787: for (n = 0; n < num_socks; n++) {
2788: close(socks[n]);
2789: }
2790: num_socks = 0;
2791: break;
2792: }
2793: socks[num_socks++] = sock;
2794: if (num_socks == NUM_SOCKS)
2795: break;
1.25 markus 2796: }
1.83 stevesk 2797: freeaddrinfo(aitop);
1.35 markus 2798: if (num_socks > 0)
2799: break;
1.25 markus 2800: }
2801: if (display_number >= MAX_DISPLAYS) {
2802: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2803: return -1;
1.25 markus 2804: }
2805: /* Start listening for connections on the socket. */
1.35 markus 2806: for (n = 0; n < num_socks; n++) {
2807: sock = socks[n];
1.199 markus 2808: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2809: error("listen: %.100s", strerror(errno));
2810: close(sock);
1.141 stevesk 2811: return -1;
1.35 markus 2812: }
1.25 markus 2813: }
1.35 markus 2814:
2815: /* Allocate a channel for each socket. */
1.242 djm 2816: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2817: for (n = 0; n < num_socks; n++) {
2818: sock = socks[n];
1.149 markus 2819: nc = channel_new("x11 listener",
1.51 markus 2820: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2821: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2822: 0, "X11 inet listener", 1);
1.167 markus 2823: nc->single_connection = single_connection;
1.224 markus 2824: (*chanids)[n] = nc->self;
1.35 markus 2825: }
1.224 markus 2826: (*chanids)[n] = -1;
1.1 deraadt 2827:
1.141 stevesk 2828: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2829: *display_numberp = display_number;
2830: return (0);
1.1 deraadt 2831: }
2832:
1.127 itojun 2833: static int
1.77 markus 2834: connect_local_xsocket(u_int dnr)
1.1 deraadt 2835: {
1.25 markus 2836: int sock;
2837: struct sockaddr_un addr;
2838:
1.147 stevesk 2839: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2840: if (sock < 0)
2841: error("socket: %.100s", strerror(errno));
2842: memset(&addr, 0, sizeof(addr));
2843: addr.sun_family = AF_UNIX;
2844: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2845: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2846: return sock;
2847: close(sock);
1.25 markus 2848: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2849: return -1;
1.1 deraadt 2850: }
2851:
1.51 markus 2852: int
2853: x11_connect_display(void)
1.1 deraadt 2854: {
1.162 stevesk 2855: int display_number, sock = 0;
1.25 markus 2856: const char *display;
1.51 markus 2857: char buf[1024], *cp;
1.35 markus 2858: struct addrinfo hints, *ai, *aitop;
2859: char strport[NI_MAXSERV];
2860: int gaierr;
1.25 markus 2861:
2862: /* Try to open a socket for the local X server. */
2863: display = getenv("DISPLAY");
2864: if (!display) {
2865: error("DISPLAY not set.");
1.51 markus 2866: return -1;
1.25 markus 2867: }
1.27 markus 2868: /*
2869: * Now we decode the value of the DISPLAY variable and make a
2870: * connection to the real X server.
2871: */
2872:
2873: /*
2874: * Check if it is a unix domain socket. Unix domain displays are in
2875: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2876: */
1.25 markus 2877: if (strncmp(display, "unix:", 5) == 0 ||
2878: display[0] == ':') {
2879: /* Connect to the unix domain socket. */
2880: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2881: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2882: display);
1.51 markus 2883: return -1;
1.25 markus 2884: }
2885: /* Create a socket. */
2886: sock = connect_local_xsocket(display_number);
2887: if (sock < 0)
1.51 markus 2888: return -1;
1.25 markus 2889:
2890: /* OK, we now have a connection to the display. */
1.51 markus 2891: return sock;
1.25 markus 2892: }
1.27 markus 2893: /*
2894: * Connect to an inet socket. The DISPLAY value is supposedly
2895: * hostname:d[.s], where hostname may also be numeric IP address.
2896: */
1.145 stevesk 2897: strlcpy(buf, display, sizeof(buf));
1.25 markus 2898: cp = strchr(buf, ':');
2899: if (!cp) {
2900: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2901: return -1;
1.25 markus 2902: }
2903: *cp = 0;
1.27 markus 2904: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2905: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2906: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2907: display);
1.51 markus 2908: return -1;
1.25 markus 2909: }
1.35 markus 2910:
2911: /* Look up the host address */
2912: memset(&hints, 0, sizeof(hints));
2913: hints.ai_family = IPv4or6;
2914: hints.ai_socktype = SOCK_STREAM;
2915: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2916: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2917: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2918: return -1;
1.25 markus 2919: }
1.35 markus 2920: for (ai = aitop; ai; ai = ai->ai_next) {
2921: /* Create a socket. */
1.189 markus 2922: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2923: if (sock < 0) {
1.194 markus 2924: debug2("socket: %.100s", strerror(errno));
1.41 markus 2925: continue;
2926: }
2927: /* Connect it to the display. */
2928: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2929: debug2("connect %.100s port %d: %.100s", buf,
1.41 markus 2930: 6000 + display_number, strerror(errno));
2931: close(sock);
2932: continue;
2933: }
2934: /* Success */
2935: break;
1.35 markus 2936: }
2937: freeaddrinfo(aitop);
2938: if (!ai) {
1.49 markus 2939: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2940: strerror(errno));
1.51 markus 2941: return -1;
1.25 markus 2942: }
1.162 stevesk 2943: set_nodelay(sock);
1.51 markus 2944: return sock;
2945: }
2946:
2947: /*
2948: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2949: * the remote channel number. We should do whatever we want, and respond
2950: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2951: */
2952:
2953: void
1.154 markus 2954: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 2955: {
1.113 markus 2956: Channel *c = NULL;
2957: int remote_id, sock = 0;
1.51 markus 2958: char *remote_host;
1.25 markus 2959:
1.113 markus 2960: debug("Received X11 open request.");
1.51 markus 2961:
1.113 markus 2962: remote_id = packet_get_int();
1.121 markus 2963:
2964: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 2965: remote_host = packet_get_string(NULL);
1.51 markus 2966: } else {
2967: remote_host = xstrdup("unknown (remote did not supply name)");
2968: }
1.152 markus 2969: packet_check_eom();
1.25 markus 2970:
1.51 markus 2971: /* Obtain a connection to the real X display. */
2972: sock = x11_connect_display();
1.113 markus 2973: if (sock != -1) {
2974: /* Allocate a channel for this connection. */
2975: c = channel_new("connected x11 socket",
2976: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2977: remote_host, 1);
1.167 markus 2978: c->remote_id = remote_id;
2979: c->force_drain = 1;
1.113 markus 2980: }
1.190 markus 2981: xfree(remote_host);
1.113 markus 2982: if (c == NULL) {
1.51 markus 2983: /* Send refusal to the remote host. */
2984: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2985: packet_put_int(remote_id);
1.51 markus 2986: } else {
2987: /* Send a confirmation to the remote host. */
2988: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2989: packet_put_int(remote_id);
2990: packet_put_int(c->self);
1.51 markus 2991: }
1.113 markus 2992: packet_send();
1.72 markus 2993: }
2994:
2995: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2996: void
1.154 markus 2997: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 2998: {
2999: int rchan = packet_get_int();
1.180 deraadt 3000:
1.143 deraadt 3001: switch (type) {
1.72 markus 3002: case SSH_SMSG_AGENT_OPEN:
3003: error("Warning: ssh server tried agent forwarding.");
3004: break;
3005: case SSH_SMSG_X11_OPEN:
3006: error("Warning: ssh server tried X11 forwarding.");
3007: break;
3008: default:
1.154 markus 3009: error("deny_input_open: type %d", type);
1.72 markus 3010: break;
3011: }
1.230 stevesk 3012: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3013: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3014: packet_put_int(rchan);
3015: packet_send();
1.1 deraadt 3016: }
3017:
1.27 markus 3018: /*
3019: * Requests forwarding of X11 connections, generates fake authentication
3020: * data, and enables authentication spoofing.
1.121 markus 3021: * This should be called in the client only.
1.27 markus 3022: */
1.49 markus 3023: void
1.215 djm 3024: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3025: const char *proto, const char *data)
1.1 deraadt 3026: {
1.77 markus 3027: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3028: u_int i, value;
1.25 markus 3029: char *new_data;
3030: int screen_number;
3031: const char *cp;
1.207 avsm 3032: u_int32_t rnd = 0;
1.25 markus 3033:
1.220 markus 3034: if (x11_saved_display == NULL)
3035: x11_saved_display = xstrdup(disp);
3036: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3037: error("x11_request_forwarding_with_spoofing: different "
3038: "$DISPLAY already forwarded");
3039: return;
3040: }
3041:
1.215 djm 3042: cp = disp;
3043: if (disp)
3044: cp = strchr(disp, ':');
1.25 markus 3045: if (cp)
3046: cp = strchr(cp, '.');
3047: if (cp)
3048: screen_number = atoi(cp + 1);
3049: else
3050: screen_number = 0;
3051:
1.219 djm 3052: if (x11_saved_proto == NULL) {
3053: /* Save protocol name. */
3054: x11_saved_proto = xstrdup(proto);
3055: /*
1.221 djm 3056: * Extract real authentication data and generate fake data
1.219 djm 3057: * of the same length.
3058: */
3059: x11_saved_data = xmalloc(data_len);
3060: x11_fake_data = xmalloc(data_len);
3061: for (i = 0; i < data_len; i++) {
3062: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3063: fatal("x11_request_forwarding: bad "
3064: "authentication data: %.100s", data);
3065: if (i % 4 == 0)
3066: rnd = arc4random();
3067: x11_saved_data[i] = value;
3068: x11_fake_data[i] = rnd & 0xff;
3069: rnd >>= 8;
3070: }
3071: x11_saved_data_len = data_len;
3072: x11_fake_data_len = data_len;
1.25 markus 3073: }
3074:
3075: /* Convert the fake data into hex. */
1.219 djm 3076: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3077:
3078: /* Send the request packet. */
1.51 markus 3079: if (compat20) {
3080: channel_request_start(client_session_id, "x11-req", 0);
3081: packet_put_char(0); /* XXX bool single connection */
3082: } else {
3083: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3084: }
3085: packet_put_cstring(proto);
3086: packet_put_cstring(new_data);
1.25 markus 3087: packet_put_int(screen_number);
3088: packet_send();
3089: packet_write_wait();
3090: xfree(new_data);
1.1 deraadt 3091: }
3092:
1.121 markus 3093:
3094: /* -- agent forwarding */
3095:
1.1 deraadt 3096: /* Sends a message to the server to request authentication fd forwarding. */
3097:
1.49 markus 3098: void
1.142 itojun 3099: auth_request_forwarding(void)
1.1 deraadt 3100: {
1.25 markus 3101: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3102: packet_send();
3103: packet_write_wait();
1.1 deraadt 3104: }
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