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