Annotation of src/usr.bin/ssh/channels.c, Revision 1.260
1.260 ! stevesk 1: /* $OpenBSD: channels.c,v 1.259 2006/07/21 21:13:30 stevesk Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.234 stevesk 43:
44: #include <sys/ioctl.h>
1.235 stevesk 45: #include <sys/types.h>
46: #include <sys/un.h>
1.251 stevesk 47: #include <sys/socket.h>
48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.255 stevesk 53: #include <netdb.h>
1.260 ! stevesk 54: #include <string.h>
1.233 stevesk 55: #include <termios.h>
1.256 stevesk 56: #include <unistd.h>
1.1 deraadt 57:
58: #include "ssh.h"
1.82 markus 59: #include "ssh1.h"
60: #include "ssh2.h"
1.1 deraadt 61: #include "packet.h"
62: #include "xmalloc.h"
1.82 markus 63: #include "log.h"
64: #include "misc.h"
1.14 markus 65: #include "channels.h"
66: #include "compat.h"
1.82 markus 67: #include "canohost.h"
1.64 markus 68: #include "key.h"
69: #include "authfd.h"
1.147 stevesk 70: #include "pathnames.h"
1.193 markus 71: #include "bufaux.h"
1.1 deraadt 72:
1.121 markus 73: /* -- channel core */
1.12 markus 74:
1.27 markus 75: /*
76: * Pointer to an array containing all allocated channels. The array is
77: * dynamically extended as needed.
78: */
1.113 markus 79: static Channel **channels = NULL;
1.1 deraadt 80:
1.27 markus 81: /*
82: * Size of the channel array. All slots of the array must always be
1.113 markus 83: * initialized (at least the type field); unused slots set to NULL
1.27 markus 84: */
1.209 avsm 85: static u_int channels_alloc = 0;
1.1 deraadt 86:
1.27 markus 87: /*
88: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 89: * updated in channel_new.
1.27 markus 90: */
1.84 markus 91: static int channel_max_fd = 0;
1.1 deraadt 92:
93:
1.121 markus 94: /* -- tcp forwarding */
1.1 deraadt 95:
1.27 markus 96: /*
97: * Data structure for storing which hosts are permitted for forward requests.
98: * The local sides of any remote forwards are stored in this array to prevent
99: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
100: * network (which might be behind a firewall).
101: */
1.25 markus 102: typedef struct {
1.41 markus 103: char *host_to_connect; /* Connect to 'host'. */
104: u_short port_to_connect; /* Connect to 'port'. */
105: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 106: } ForwardPermission;
107:
1.257 dtucker 108: /* List of all permitted host/port pairs to connect by the user. */
1.1 deraadt 109: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.121 markus 110:
1.257 dtucker 111: /* List of all permitted host/port pairs to connect by the admin. */
112: static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
113:
114: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 115: static int num_permitted_opens = 0;
1.257 dtucker 116:
117: /* Number of permitted host/port pair in the array permitted by the admin. */
118: static int num_adm_permitted_opens = 0;
119:
1.27 markus 120: /*
121: * If this is true, all opens are permitted. This is the case on the server
122: * on which we have to trust the client anyway, and the user could do
123: * anything after logging in anyway.
124: */
1.1 deraadt 125: static int all_opens_permitted = 0;
126:
1.121 markus 127:
128: /* -- X11 forwarding */
129:
130: /* Maximum number of fake X11 displays to try. */
131: #define MAX_DISPLAYS 1000
132:
1.219 djm 133: /* Saved X11 local (client) display. */
134: static char *x11_saved_display = NULL;
135:
1.121 markus 136: /* Saved X11 authentication protocol name. */
137: static char *x11_saved_proto = NULL;
138:
139: /* Saved X11 authentication data. This is the real data. */
140: static char *x11_saved_data = NULL;
141: static u_int x11_saved_data_len = 0;
142:
143: /*
144: * Fake X11 authentication data. This is what the server will be sending us;
145: * we should replace any occurrences of this by the real data.
146: */
1.240 deraadt 147: static u_char *x11_fake_data = NULL;
1.121 markus 148: static u_int x11_fake_data_len;
149:
150:
151: /* -- agent forwarding */
152:
153: #define NUM_SOCKS 10
154:
1.82 markus 155: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 156: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 157:
1.121 markus 158: /* helper */
1.127 itojun 159: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 160:
1.121 markus 161: /* -- channel core */
1.41 markus 162:
163: Channel *
1.229 markus 164: channel_by_id(int id)
1.41 markus 165: {
166: Channel *c;
1.113 markus 167:
1.209 avsm 168: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 169: logit("channel_by_id: %d: bad id", id);
1.41 markus 170: return NULL;
171: }
1.113 markus 172: c = channels[id];
173: if (c == NULL) {
1.229 markus 174: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 175: return NULL;
176: }
177: return c;
1.55 markus 178: }
179:
1.27 markus 180: /*
1.229 markus 181: * Returns the channel if it is allowed to receive protocol messages.
182: * Private channels, like listening sockets, may not receive messages.
183: */
184: Channel *
185: channel_lookup(int id)
186: {
187: Channel *c;
188:
189: if ((c = channel_by_id(id)) == NULL)
190: return (NULL);
191:
1.237 deraadt 192: switch (c->type) {
1.229 markus 193: case SSH_CHANNEL_X11_OPEN:
194: case SSH_CHANNEL_LARVAL:
195: case SSH_CHANNEL_CONNECTING:
196: case SSH_CHANNEL_DYNAMIC:
197: case SSH_CHANNEL_OPENING:
198: case SSH_CHANNEL_OPEN:
199: case SSH_CHANNEL_INPUT_DRAINING:
200: case SSH_CHANNEL_OUTPUT_DRAINING:
201: return (c);
202: }
203: logit("Non-public channel %d, type %d.", id, c->type);
204: return (NULL);
205: }
206:
207: /*
1.55 markus 208: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 209: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 210: */
1.127 itojun 211: static void
1.71 markus 212: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
213: int extusage, int nonblock)
1.1 deraadt 214: {
1.25 markus 215: /* Update the maximum file descriptor value. */
1.84 markus 216: channel_max_fd = MAX(channel_max_fd, rfd);
217: channel_max_fd = MAX(channel_max_fd, wfd);
218: channel_max_fd = MAX(channel_max_fd, efd);
219:
1.27 markus 220: /* XXX set close-on-exec -markus */
1.55 markus 221:
1.52 markus 222: c->rfd = rfd;
223: c->wfd = wfd;
224: c->sock = (rfd == wfd) ? rfd : -1;
1.204 djm 225: c->ctl_fd = -1; /* XXX: set elsewhere */
1.52 markus 226: c->efd = efd;
227: c->extended_usage = extusage;
1.71 markus 228:
1.91 markus 229: /* XXX ugly hack: nonblock is only set by the server */
230: if (nonblock && isatty(c->rfd)) {
1.194 markus 231: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 232: c->isatty = 1;
233: if (!isatty(c->wfd)) {
1.94 markus 234: error("channel %d: wfd %d is not a tty?",
1.91 markus 235: c->self, c->wfd);
236: }
237: } else {
238: c->isatty = 0;
239: }
240:
1.71 markus 241: /* enable nonblocking mode */
242: if (nonblock) {
243: if (rfd != -1)
244: set_nonblock(rfd);
245: if (wfd != -1)
246: set_nonblock(wfd);
247: if (efd != -1)
248: set_nonblock(efd);
249: }
1.52 markus 250: }
251:
252: /*
253: * Allocate a new channel object and set its type and socket. This will cause
254: * remote_name to be freed.
255: */
1.113 markus 256: Channel *
1.52 markus 257: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 258: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 259: {
1.209 avsm 260: int found;
261: u_int i;
1.52 markus 262: Channel *c;
1.25 markus 263:
264: /* Do initial allocation if this is the first call. */
265: if (channels_alloc == 0) {
266: channels_alloc = 10;
1.242 djm 267: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 268: for (i = 0; i < channels_alloc; i++)
1.113 markus 269: channels[i] = NULL;
1.25 markus 270: }
271: /* Try to find a free slot where to put the new channel. */
272: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 273: if (channels[i] == NULL) {
1.25 markus 274: /* Found a free slot. */
1.209 avsm 275: found = (int)i;
1.25 markus 276: break;
277: }
1.209 avsm 278: if (found < 0) {
1.27 markus 279: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 280: found = channels_alloc;
1.179 markus 281: if (channels_alloc > 10000)
282: fatal("channel_new: internal error: channels_alloc %d "
283: "too big.", channels_alloc);
1.243 djm 284: channels = xrealloc(channels, channels_alloc + 10,
285: sizeof(Channel *));
1.195 markus 286: channels_alloc += 10;
1.70 markus 287: debug2("channel: expanding %d", channels_alloc);
1.25 markus 288: for (i = found; i < channels_alloc; i++)
1.113 markus 289: channels[i] = NULL;
1.25 markus 290: }
1.113 markus 291: /* Initialize and return new channel. */
1.242 djm 292: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 293: buffer_init(&c->input);
294: buffer_init(&c->output);
1.41 markus 295: buffer_init(&c->extended);
1.159 markus 296: c->ostate = CHAN_OUTPUT_OPEN;
297: c->istate = CHAN_INPUT_OPEN;
298: c->flags = 0;
1.71 markus 299: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 300: c->self = found;
301: c->type = type;
1.41 markus 302: c->ctype = ctype;
1.51 markus 303: c->local_window = window;
304: c->local_window_max = window;
305: c->local_consumed = 0;
306: c->local_maxpacket = maxpack;
1.25 markus 307: c->remote_id = -1;
1.190 markus 308: c->remote_name = xstrdup(remote_name);
1.41 markus 309: c->remote_window = 0;
310: c->remote_maxpacket = 0;
1.133 markus 311: c->force_drain = 0;
1.149 markus 312: c->single_connection = 0;
1.131 markus 313: c->detach_user = NULL;
1.225 djm 314: c->detach_close = 0;
1.165 markus 315: c->confirm = NULL;
1.204 djm 316: c->confirm_ctx = NULL;
1.65 markus 317: c->input_filter = NULL;
1.231 reyk 318: c->output_filter = NULL;
1.25 markus 319: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 320: return c;
1.1 deraadt 321: }
1.52 markus 322:
1.132 markus 323: static int
324: channel_find_maxfd(void)
325: {
1.209 avsm 326: u_int i;
327: int max = 0;
1.132 markus 328: Channel *c;
329:
330: for (i = 0; i < channels_alloc; i++) {
331: c = channels[i];
332: if (c != NULL) {
333: max = MAX(max, c->rfd);
334: max = MAX(max, c->wfd);
335: max = MAX(max, c->efd);
336: }
337: }
338: return max;
339: }
340:
341: int
342: channel_close_fd(int *fdp)
343: {
344: int ret = 0, fd = *fdp;
345:
346: if (fd != -1) {
347: ret = close(fd);
348: *fdp = -1;
349: if (fd == channel_max_fd)
350: channel_max_fd = channel_find_maxfd();
351: }
352: return ret;
353: }
354:
1.52 markus 355: /* Close all channel fd/socket. */
1.127 itojun 356: static void
1.52 markus 357: channel_close_fds(Channel *c)
358: {
1.204 djm 359: debug3("channel %d: close_fds r %d w %d e %d c %d",
360: c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
1.118 markus 361:
1.132 markus 362: channel_close_fd(&c->sock);
1.204 djm 363: channel_close_fd(&c->ctl_fd);
1.132 markus 364: channel_close_fd(&c->rfd);
365: channel_close_fd(&c->wfd);
366: channel_close_fd(&c->efd);
1.121 markus 367: }
368:
369: /* Free the channel and close its fd/socket. */
370: void
371: channel_free(Channel *c)
372: {
373: char *s;
1.209 avsm 374: u_int i, n;
1.121 markus 375:
376: for (n = 0, i = 0; i < channels_alloc; i++)
377: if (channels[i])
378: n++;
1.209 avsm 379: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 380: c->remote_name ? c->remote_name : "???", n);
381:
382: s = channel_open_message();
1.194 markus 383: debug3("channel %d: status: %s", c->self, s);
1.121 markus 384: xfree(s);
385:
386: if (c->sock != -1)
387: shutdown(c->sock, SHUT_RDWR);
1.204 djm 388: if (c->ctl_fd != -1)
389: shutdown(c->ctl_fd, SHUT_RDWR);
1.121 markus 390: channel_close_fds(c);
391: buffer_free(&c->input);
392: buffer_free(&c->output);
393: buffer_free(&c->extended);
394: if (c->remote_name) {
395: xfree(c->remote_name);
396: c->remote_name = NULL;
397: }
398: channels[c->self] = NULL;
399: xfree(c);
400: }
401:
402: void
1.126 markus 403: channel_free_all(void)
1.121 markus 404: {
1.209 avsm 405: u_int i;
1.121 markus 406:
1.126 markus 407: for (i = 0; i < channels_alloc; i++)
408: if (channels[i] != NULL)
409: channel_free(channels[i]);
1.131 markus 410: }
411:
1.121 markus 412: /*
413: * Closes the sockets/fds of all channels. This is used to close extra file
414: * descriptors after a fork.
415: */
416: void
1.142 itojun 417: channel_close_all(void)
1.121 markus 418: {
1.209 avsm 419: u_int i;
1.121 markus 420:
421: for (i = 0; i < channels_alloc; i++)
422: if (channels[i] != NULL)
423: channel_close_fds(channels[i]);
424: }
425:
426: /*
1.131 markus 427: * Stop listening to channels.
428: */
429: void
430: channel_stop_listening(void)
431: {
1.209 avsm 432: u_int i;
1.131 markus 433: Channel *c;
434:
435: for (i = 0; i < channels_alloc; i++) {
436: c = channels[i];
437: if (c != NULL) {
438: switch (c->type) {
439: case SSH_CHANNEL_AUTH_SOCKET:
440: case SSH_CHANNEL_PORT_LISTENER:
441: case SSH_CHANNEL_RPORT_LISTENER:
442: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 443: channel_close_fd(&c->sock);
1.131 markus 444: channel_free(c);
445: break;
446: }
447: }
448: }
449: }
450:
451: /*
1.121 markus 452: * Returns true if no channel has too much buffered data, and false if one or
453: * more channel is overfull.
454: */
455: int
1.142 itojun 456: channel_not_very_much_buffered_data(void)
1.121 markus 457: {
458: u_int i;
459: Channel *c;
460:
461: for (i = 0; i < channels_alloc; i++) {
462: c = channels[i];
463: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 464: #if 0
465: if (!compat20 &&
466: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 467: debug2("channel %d: big input buffer %d",
1.121 markus 468: c->self, buffer_len(&c->input));
469: return 0;
470: }
1.136 markus 471: #endif
1.121 markus 472: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 473: debug2("channel %d: big output buffer %u > %u",
1.136 markus 474: c->self, buffer_len(&c->output),
475: packet_get_maxsize());
1.121 markus 476: return 0;
477: }
478: }
479: }
480: return 1;
481: }
482:
483: /* Returns true if any channel is still open. */
484: int
1.142 itojun 485: channel_still_open(void)
1.121 markus 486: {
1.209 avsm 487: u_int i;
1.121 markus 488: Channel *c;
489:
490: for (i = 0; i < channels_alloc; i++) {
491: c = channels[i];
492: if (c == NULL)
493: continue;
494: switch (c->type) {
495: case SSH_CHANNEL_X11_LISTENER:
496: case SSH_CHANNEL_PORT_LISTENER:
497: case SSH_CHANNEL_RPORT_LISTENER:
498: case SSH_CHANNEL_CLOSED:
499: case SSH_CHANNEL_AUTH_SOCKET:
500: case SSH_CHANNEL_DYNAMIC:
501: case SSH_CHANNEL_CONNECTING:
502: case SSH_CHANNEL_ZOMBIE:
503: continue;
504: case SSH_CHANNEL_LARVAL:
505: if (!compat20)
506: fatal("cannot happen: SSH_CHANNEL_LARVAL");
507: continue;
508: case SSH_CHANNEL_OPENING:
509: case SSH_CHANNEL_OPEN:
510: case SSH_CHANNEL_X11_OPEN:
511: return 1;
512: case SSH_CHANNEL_INPUT_DRAINING:
513: case SSH_CHANNEL_OUTPUT_DRAINING:
514: if (!compat13)
515: fatal("cannot happen: OUT_DRAIN");
516: return 1;
517: default:
518: fatal("channel_still_open: bad channel type %d", c->type);
519: /* NOTREACHED */
520: }
521: }
522: return 0;
523: }
524:
525: /* Returns the id of an open channel suitable for keepaliving */
526: int
1.142 itojun 527: channel_find_open(void)
1.121 markus 528: {
1.209 avsm 529: u_int i;
1.121 markus 530: Channel *c;
531:
532: for (i = 0; i < channels_alloc; i++) {
533: c = channels[i];
1.206 djm 534: if (c == NULL || c->remote_id < 0)
1.121 markus 535: continue;
536: switch (c->type) {
537: case SSH_CHANNEL_CLOSED:
538: case SSH_CHANNEL_DYNAMIC:
539: case SSH_CHANNEL_X11_LISTENER:
540: case SSH_CHANNEL_PORT_LISTENER:
541: case SSH_CHANNEL_RPORT_LISTENER:
542: case SSH_CHANNEL_OPENING:
543: case SSH_CHANNEL_CONNECTING:
544: case SSH_CHANNEL_ZOMBIE:
545: continue;
546: case SSH_CHANNEL_LARVAL:
547: case SSH_CHANNEL_AUTH_SOCKET:
548: case SSH_CHANNEL_OPEN:
549: case SSH_CHANNEL_X11_OPEN:
550: return i;
551: case SSH_CHANNEL_INPUT_DRAINING:
552: case SSH_CHANNEL_OUTPUT_DRAINING:
553: if (!compat13)
554: fatal("cannot happen: OUT_DRAIN");
555: return i;
556: default:
557: fatal("channel_find_open: bad channel type %d", c->type);
558: /* NOTREACHED */
559: }
560: }
561: return -1;
562: }
563:
564:
565: /*
566: * Returns a message describing the currently open forwarded connections,
567: * suitable for sending to the client. The message contains crlf pairs for
568: * newlines.
569: */
570: char *
1.142 itojun 571: channel_open_message(void)
1.121 markus 572: {
573: Buffer buffer;
574: Channel *c;
575: char buf[1024], *cp;
1.209 avsm 576: u_int i;
1.121 markus 577:
578: buffer_init(&buffer);
579: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
580: buffer_append(&buffer, buf, strlen(buf));
581: for (i = 0; i < channels_alloc; i++) {
582: c = channels[i];
583: if (c == NULL)
584: continue;
585: switch (c->type) {
586: case SSH_CHANNEL_X11_LISTENER:
587: case SSH_CHANNEL_PORT_LISTENER:
588: case SSH_CHANNEL_RPORT_LISTENER:
589: case SSH_CHANNEL_CLOSED:
590: case SSH_CHANNEL_AUTH_SOCKET:
591: case SSH_CHANNEL_ZOMBIE:
592: continue;
593: case SSH_CHANNEL_LARVAL:
594: case SSH_CHANNEL_OPENING:
595: case SSH_CHANNEL_CONNECTING:
596: case SSH_CHANNEL_DYNAMIC:
597: case SSH_CHANNEL_OPEN:
598: case SSH_CHANNEL_X11_OPEN:
599: case SSH_CHANNEL_INPUT_DRAINING:
600: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 601: snprintf(buf, sizeof buf,
602: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
1.121 markus 603: c->self, c->remote_name,
604: c->type, c->remote_id,
605: c->istate, buffer_len(&c->input),
606: c->ostate, buffer_len(&c->output),
1.204 djm 607: c->rfd, c->wfd, c->ctl_fd);
1.121 markus 608: buffer_append(&buffer, buf, strlen(buf));
609: continue;
610: default:
611: fatal("channel_open_message: bad channel type %d", c->type);
612: /* NOTREACHED */
613: }
614: }
615: buffer_append(&buffer, "\0", 1);
616: cp = xstrdup(buffer_ptr(&buffer));
617: buffer_free(&buffer);
618: return cp;
619: }
620:
621: void
622: channel_send_open(int id)
623: {
624: Channel *c = channel_lookup(id);
1.180 deraadt 625:
1.121 markus 626: if (c == NULL) {
1.188 itojun 627: logit("channel_send_open: %d: bad id", id);
1.121 markus 628: return;
629: }
1.184 markus 630: debug2("channel %d: send open", id);
1.121 markus 631: packet_start(SSH2_MSG_CHANNEL_OPEN);
632: packet_put_cstring(c->ctype);
633: packet_put_int(c->self);
634: packet_put_int(c->local_window);
635: packet_put_int(c->local_maxpacket);
636: packet_send();
637: }
638:
639: void
1.184 markus 640: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 641: {
1.184 markus 642: Channel *c = channel_lookup(id);
1.180 deraadt 643:
1.121 markus 644: if (c == NULL) {
1.188 itojun 645: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 646: return;
647: }
1.204 djm 648: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 649: packet_start(SSH2_MSG_CHANNEL_REQUEST);
650: packet_put_int(c->remote_id);
651: packet_put_cstring(service);
652: packet_put_char(wantconfirm);
653: }
1.241 deraadt 654:
1.121 markus 655: void
1.204 djm 656: channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
1.121 markus 657: {
658: Channel *c = channel_lookup(id);
1.180 deraadt 659:
1.121 markus 660: if (c == NULL) {
1.188 itojun 661: logit("channel_register_comfirm: %d: bad id", id);
1.121 markus 662: return;
663: }
1.165 markus 664: c->confirm = fn;
1.204 djm 665: c->confirm_ctx = ctx;
1.121 markus 666: }
1.241 deraadt 667:
1.121 markus 668: void
1.225 djm 669: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 670: {
1.229 markus 671: Channel *c = channel_by_id(id);
1.180 deraadt 672:
1.121 markus 673: if (c == NULL) {
1.188 itojun 674: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 675: return;
676: }
1.131 markus 677: c->detach_user = fn;
1.225 djm 678: c->detach_close = do_close;
1.121 markus 679: }
1.241 deraadt 680:
1.121 markus 681: void
682: channel_cancel_cleanup(int id)
683: {
1.229 markus 684: Channel *c = channel_by_id(id);
1.180 deraadt 685:
1.121 markus 686: if (c == NULL) {
1.188 itojun 687: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 688: return;
1.52 markus 689: }
1.131 markus 690: c->detach_user = NULL;
1.225 djm 691: c->detach_close = 0;
1.121 markus 692: }
1.241 deraadt 693:
1.121 markus 694: void
1.231 reyk 695: channel_register_filter(int id, channel_infilter_fn *ifn,
696: channel_outfilter_fn *ofn)
1.121 markus 697: {
698: Channel *c = channel_lookup(id);
1.180 deraadt 699:
1.121 markus 700: if (c == NULL) {
1.188 itojun 701: logit("channel_register_filter: %d: bad id", id);
1.121 markus 702: return;
1.52 markus 703: }
1.231 reyk 704: c->input_filter = ifn;
705: c->output_filter = ofn;
1.52 markus 706: }
707:
1.49 markus 708: void
1.121 markus 709: channel_set_fds(int id, int rfd, int wfd, int efd,
1.168 markus 710: int extusage, int nonblock, u_int window_max)
1.1 deraadt 711: {
1.121 markus 712: Channel *c = channel_lookup(id);
1.180 deraadt 713:
1.121 markus 714: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
715: fatal("channel_activate for non-larval channel %d.", id);
716: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
717: c->type = SSH_CHANNEL_OPEN;
1.168 markus 718: c->local_window = c->local_window_max = window_max;
1.121 markus 719: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
720: packet_put_int(c->remote_id);
721: packet_put_int(c->local_window);
722: packet_send();
1.1 deraadt 723: }
724:
1.27 markus 725: /*
1.41 markus 726: * 'channel_pre*' are called just before select() to add any bits relevant to
727: * channels in the select bitmasks.
728: */
729: /*
730: * 'channel_post*': perform any appropriate operations for channels which
731: * have events pending.
1.27 markus 732: */
1.237 deraadt 733: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 734: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
735: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
736:
1.259 stevesk 737: /* ARGSUSED */
1.127 itojun 738: static void
1.237 deraadt 739: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 740: {
741: FD_SET(c->sock, readset);
742: }
743:
1.259 stevesk 744: /* ARGSUSED */
1.127 itojun 745: static void
1.237 deraadt 746: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 747: {
748: debug3("channel %d: waiting for connection", c->self);
749: FD_SET(c->sock, writeset);
750: }
751:
1.127 itojun 752: static void
1.237 deraadt 753: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 754: {
755: if (buffer_len(&c->input) < packet_get_maxsize())
756: FD_SET(c->sock, readset);
757: if (buffer_len(&c->output) > 0)
758: FD_SET(c->sock, writeset);
759: }
1.1 deraadt 760:
1.127 itojun 761: static void
1.237 deraadt 762: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 763: {
1.157 markus 764: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 765:
1.44 markus 766: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 767: limit > 0 &&
1.250 djm 768: buffer_len(&c->input) < limit &&
769: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 770: FD_SET(c->rfd, readset);
771: if (c->ostate == CHAN_OUTPUT_OPEN ||
772: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
773: if (buffer_len(&c->output) > 0) {
774: FD_SET(c->wfd, writeset);
775: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 776: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 777: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
778: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 779: else
780: chan_obuf_empty(c);
1.44 markus 781: }
782: }
783: /** XXX check close conditions, too */
1.157 markus 784: if (compat20 && c->efd != -1) {
1.44 markus 785: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
786: buffer_len(&c->extended) > 0)
787: FD_SET(c->efd, writeset);
1.172 markus 788: else if (!(c->flags & CHAN_EOF_SENT) &&
789: c->extended_usage == CHAN_EXTENDED_READ &&
1.44 markus 790: buffer_len(&c->extended) < c->remote_window)
791: FD_SET(c->efd, readset);
792: }
1.204 djm 793: /* XXX: What about efd? races? */
1.208 deraadt 794: if (compat20 && c->ctl_fd != -1 &&
1.204 djm 795: c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
796: FD_SET(c->ctl_fd, readset);
1.44 markus 797: }
798:
1.259 stevesk 799: /* ARGSUSED */
1.127 itojun 800: static void
1.237 deraadt 801: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 802: {
803: if (buffer_len(&c->input) == 0) {
804: packet_start(SSH_MSG_CHANNEL_CLOSE);
805: packet_put_int(c->remote_id);
806: packet_send();
807: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 808: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 809: }
810: }
811:
1.259 stevesk 812: /* ARGSUSED */
1.127 itojun 813: static void
1.237 deraadt 814: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 815: {
816: if (buffer_len(&c->output) == 0)
1.113 markus 817: chan_mark_dead(c);
1.49 markus 818: else
1.41 markus 819: FD_SET(c->sock, writeset);
820: }
821:
822: /*
823: * This is a special state for X11 authentication spoofing. An opened X11
824: * connection (when authentication spoofing is being done) remains in this
825: * state until the first packet has been completely read. The authentication
826: * data in that packet is then substituted by the real data if it matches the
827: * fake data, and the channel is put into normal mode.
1.51 markus 828: * XXX All this happens at the client side.
1.121 markus 829: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 830: */
1.127 itojun 831: static int
1.121 markus 832: x11_open_helper(Buffer *b)
1.1 deraadt 833: {
1.77 markus 834: u_char *ucp;
835: u_int proto_len, data_len;
1.25 markus 836:
1.41 markus 837: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 838: if (buffer_len(b) < 12)
1.41 markus 839: return 0;
840:
841: /* Parse the lengths of variable-length fields. */
1.155 stevesk 842: ucp = buffer_ptr(b);
1.41 markus 843: if (ucp[0] == 0x42) { /* Byte order MSB first. */
844: proto_len = 256 * ucp[6] + ucp[7];
845: data_len = 256 * ucp[8] + ucp[9];
846: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
847: proto_len = ucp[6] + 256 * ucp[7];
848: data_len = ucp[8] + 256 * ucp[9];
849: } else {
1.194 markus 850: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 851: ucp[0]);
1.41 markus 852: return -1;
853: }
854:
855: /* Check if the whole packet is in buffer. */
1.121 markus 856: if (buffer_len(b) <
1.41 markus 857: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
858: return 0;
859:
860: /* Check if authentication protocol matches. */
861: if (proto_len != strlen(x11_saved_proto) ||
862: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 863: debug2("X11 connection uses different authentication protocol.");
1.41 markus 864: return -1;
865: }
866: /* Check if authentication data matches our fake data. */
867: if (data_len != x11_fake_data_len ||
868: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
869: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 870: debug2("X11 auth data does not match fake data.");
1.41 markus 871: return -1;
872: }
873: /* Check fake data length */
874: if (x11_fake_data_len != x11_saved_data_len) {
875: error("X11 fake_data_len %d != saved_data_len %d",
876: x11_fake_data_len, x11_saved_data_len);
877: return -1;
878: }
879: /*
880: * Received authentication protocol and data match
881: * our fake data. Substitute the fake data with real
882: * data.
883: */
884: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
885: x11_saved_data, x11_saved_data_len);
886: return 1;
887: }
888:
1.127 itojun 889: static void
1.237 deraadt 890: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 891: {
1.121 markus 892: int ret = x11_open_helper(&c->output);
1.180 deraadt 893:
1.41 markus 894: if (ret == 1) {
895: /* Start normal processing for the channel. */
896: c->type = SSH_CHANNEL_OPEN;
1.47 markus 897: channel_pre_open_13(c, readset, writeset);
1.41 markus 898: } else if (ret == -1) {
899: /*
900: * We have received an X11 connection that has bad
901: * authentication information.
902: */
1.188 itojun 903: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 904: buffer_clear(&c->input);
905: buffer_clear(&c->output);
1.132 markus 906: channel_close_fd(&c->sock);
1.41 markus 907: c->sock = -1;
908: c->type = SSH_CHANNEL_CLOSED;
909: packet_start(SSH_MSG_CHANNEL_CLOSE);
910: packet_put_int(c->remote_id);
911: packet_send();
912: }
913: }
1.25 markus 914:
1.127 itojun 915: static void
1.237 deraadt 916: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 917: {
1.121 markus 918: int ret = x11_open_helper(&c->output);
1.133 markus 919:
920: /* c->force_drain = 1; */
921:
1.41 markus 922: if (ret == 1) {
923: c->type = SSH_CHANNEL_OPEN;
1.157 markus 924: channel_pre_open(c, readset, writeset);
1.41 markus 925: } else if (ret == -1) {
1.188 itojun 926: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 927: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 928: chan_read_failed(c);
929: buffer_clear(&c->input);
930: chan_ibuf_empty(c);
931: buffer_clear(&c->output);
932: /* for proto v1, the peer will send an IEOF */
933: if (compat20)
934: chan_write_failed(c);
935: else
936: c->type = SSH_CHANNEL_OPEN;
1.194 markus 937: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 938: }
939: }
1.25 markus 940:
1.104 markus 941: /* try to decode a socks4 header */
1.259 stevesk 942: /* ARGSUSED */
1.127 itojun 943: static int
1.237 deraadt 944: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 945: {
1.181 markus 946: char *p, *host;
1.217 djm 947: u_int len, have, i, found;
1.148 deraadt 948: char username[256];
1.103 markus 949: struct {
950: u_int8_t version;
951: u_int8_t command;
952: u_int16_t dest_port;
1.104 markus 953: struct in_addr dest_addr;
1.103 markus 954: } s4_req, s4_rsp;
955:
1.104 markus 956: debug2("channel %d: decode socks4", c->self);
1.109 markus 957:
958: have = buffer_len(&c->input);
959: len = sizeof(s4_req);
960: if (have < len)
961: return 0;
962: p = buffer_ptr(&c->input);
963: for (found = 0, i = len; i < have; i++) {
964: if (p[i] == '\0') {
965: found = 1;
966: break;
967: }
968: if (i > 1024) {
969: /* the peer is probably sending garbage */
970: debug("channel %d: decode socks4: too long",
971: c->self);
972: return -1;
973: }
974: }
975: if (!found)
976: return 0;
1.103 markus 977: buffer_get(&c->input, (char *)&s4_req.version, 1);
978: buffer_get(&c->input, (char *)&s4_req.command, 1);
979: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 980: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 981: have = buffer_len(&c->input);
1.103 markus 982: p = buffer_ptr(&c->input);
983: len = strlen(p);
1.106 markus 984: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 985: if (len > have)
1.104 markus 986: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 987: c->self, len, have);
988: strlcpy(username, p, sizeof(username));
989: buffer_consume(&c->input, len);
990: buffer_consume(&c->input, 1); /* trailing '\0' */
991:
1.104 markus 992: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 993: strlcpy(c->path, host, sizeof(c->path));
994: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 995:
1.194 markus 996: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.106 markus 997: c->self, host, c->host_port, s4_req.command);
1.103 markus 998:
1.104 markus 999: if (s4_req.command != 1) {
1000: debug("channel %d: cannot handle: socks4 cn %d",
1001: c->self, s4_req.command);
1002: return -1;
1.103 markus 1003: }
1.104 markus 1004: s4_rsp.version = 0; /* vn: 0 for reply */
1005: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1006: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1007: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1008: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1009: return 1;
1010: }
1011:
1.193 markus 1012: /* try to decode a socks5 header */
1013: #define SSH_SOCKS5_AUTHDONE 0x1000
1014: #define SSH_SOCKS5_NOAUTH 0x00
1015: #define SSH_SOCKS5_IPV4 0x01
1016: #define SSH_SOCKS5_DOMAIN 0x03
1017: #define SSH_SOCKS5_IPV6 0x04
1018: #define SSH_SOCKS5_CONNECT 0x01
1019: #define SSH_SOCKS5_SUCCESS 0x00
1020:
1.259 stevesk 1021: /* ARGSUSED */
1.193 markus 1022: static int
1.237 deraadt 1023: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1024: {
1025: struct {
1026: u_int8_t version;
1027: u_int8_t command;
1028: u_int8_t reserved;
1029: u_int8_t atyp;
1030: } s5_req, s5_rsp;
1031: u_int16_t dest_port;
1032: u_char *p, dest_addr[255+1];
1.252 djm 1033: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1034:
1035: debug2("channel %d: decode socks5", c->self);
1036: p = buffer_ptr(&c->input);
1037: if (p[0] != 0x05)
1038: return -1;
1039: have = buffer_len(&c->input);
1040: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1041: /* format: ver | nmethods | methods */
1.198 djm 1042: if (have < 2)
1.193 markus 1043: return 0;
1044: nmethods = p[1];
1045: if (have < nmethods + 2)
1046: return 0;
1047: /* look for method: "NO AUTHENTICATION REQUIRED" */
1048: for (found = 0, i = 2 ; i < nmethods + 2; i++) {
1049: if (p[i] == SSH_SOCKS5_NOAUTH ) {
1050: found = 1;
1051: break;
1052: }
1053: }
1054: if (!found) {
1055: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1056: c->self);
1057: return -1;
1058: }
1059: buffer_consume(&c->input, nmethods + 2);
1060: buffer_put_char(&c->output, 0x05); /* version */
1061: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1062: FD_SET(c->sock, writeset);
1063: c->flags |= SSH_SOCKS5_AUTHDONE;
1064: debug2("channel %d: socks5 auth done", c->self);
1065: return 0; /* need more */
1066: }
1067: debug2("channel %d: socks5 post auth", c->self);
1068: if (have < sizeof(s5_req)+1)
1069: return 0; /* need more */
1.247 deraadt 1070: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1071: if (s5_req.version != 0x05 ||
1072: s5_req.command != SSH_SOCKS5_CONNECT ||
1073: s5_req.reserved != 0x00) {
1.194 markus 1074: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1075: return -1;
1076: }
1.213 deraadt 1077: switch (s5_req.atyp){
1.193 markus 1078: case SSH_SOCKS5_IPV4:
1079: addrlen = 4;
1080: af = AF_INET;
1081: break;
1082: case SSH_SOCKS5_DOMAIN:
1083: addrlen = p[sizeof(s5_req)];
1084: af = -1;
1085: break;
1086: case SSH_SOCKS5_IPV6:
1087: addrlen = 16;
1088: af = AF_INET6;
1089: break;
1090: default:
1.194 markus 1091: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1092: return -1;
1093: }
1.252 djm 1094: need = sizeof(s5_req) + addrlen + 2;
1095: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1096: need++;
1097: if (have < need)
1.193 markus 1098: return 0;
1099: buffer_consume(&c->input, sizeof(s5_req));
1100: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1101: buffer_consume(&c->input, 1); /* host string length */
1102: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1103: buffer_get(&c->input, (char *)&dest_port, 2);
1104: dest_addr[addrlen] = '\0';
1105: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1.201 deraadt 1106: strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1.193 markus 1107: else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1108: return -1;
1109: c->host_port = ntohs(dest_port);
1.198 djm 1110:
1.194 markus 1111: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1112: c->self, c->path, c->host_port, s5_req.command);
1113:
1114: s5_rsp.version = 0x05;
1115: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1116: s5_rsp.reserved = 0; /* ignored */
1117: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1118: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1119: dest_port = 0; /* ignored */
1120:
1.246 deraadt 1121: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1122: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1123: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1124: return 1;
1125: }
1126:
1.104 markus 1127: /* dynamic port forwarding */
1.127 itojun 1128: static void
1.237 deraadt 1129: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1130: {
1131: u_char *p;
1.217 djm 1132: u_int have;
1133: int ret;
1.103 markus 1134:
1.104 markus 1135: have = buffer_len(&c->input);
1.137 markus 1136: c->delayed = 0;
1.104 markus 1137: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1138: /* buffer_dump(&c->input); */
1.104 markus 1139: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1140: if (have < 3) {
1.104 markus 1141: /* need more */
1142: FD_SET(c->sock, readset);
1143: return;
1144: }
1145: /* try to guess the protocol */
1146: p = buffer_ptr(&c->input);
1147: switch (p[0]) {
1148: case 0x04:
1149: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1150: break;
1151: case 0x05:
1152: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1153: break;
1154: default:
1155: ret = -1;
1156: break;
1157: }
1158: if (ret < 0) {
1.113 markus 1159: chan_mark_dead(c);
1.104 markus 1160: } else if (ret == 0) {
1161: debug2("channel %d: pre_dynamic: need more", c->self);
1162: /* need more */
1163: FD_SET(c->sock, readset);
1164: } else {
1165: /* switch to the next state */
1166: c->type = SSH_CHANNEL_OPENING;
1167: port_open_helper(c, "direct-tcpip");
1168: }
1.103 markus 1169: }
1170:
1.41 markus 1171: /* This is our fake X11 server socket. */
1.259 stevesk 1172: /* ARGSUSED */
1.127 itojun 1173: static void
1.237 deraadt 1174: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1175: {
1.113 markus 1176: Channel *nc;
1.41 markus 1177: struct sockaddr addr;
1.162 stevesk 1178: int newsock;
1.41 markus 1179: socklen_t addrlen;
1.85 markus 1180: char buf[16384], *remote_ipaddr;
1.51 markus 1181: int remote_port;
1.25 markus 1182:
1.41 markus 1183: if (FD_ISSET(c->sock, readset)) {
1184: debug("X11 connection requested.");
1185: addrlen = sizeof(addr);
1186: newsock = accept(c->sock, &addr, &addrlen);
1.149 markus 1187: if (c->single_connection) {
1.194 markus 1188: debug2("single_connection: closing X11 listener.");
1.149 markus 1189: channel_close_fd(&c->sock);
1190: chan_mark_dead(c);
1191: }
1.41 markus 1192: if (newsock < 0) {
1193: error("accept: %.100s", strerror(errno));
1194: return;
1195: }
1.162 stevesk 1196: set_nodelay(newsock);
1.85 markus 1197: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1198: remote_port = get_peer_port(newsock);
1.41 markus 1199: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1200: remote_ipaddr, remote_port);
1.51 markus 1201:
1.113 markus 1202: nc = channel_new("accepted x11 socket",
1.51 markus 1203: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1204: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1205: if (compat20) {
1206: packet_start(SSH2_MSG_CHANNEL_OPEN);
1207: packet_put_cstring("x11");
1.113 markus 1208: packet_put_int(nc->self);
1.149 markus 1209: packet_put_int(nc->local_window_max);
1210: packet_put_int(nc->local_maxpacket);
1.85 markus 1211: /* originator ipaddr and port */
1212: packet_put_cstring(remote_ipaddr);
1.57 markus 1213: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1214: debug2("ssh2 x11 bug compat mode");
1.57 markus 1215: } else {
1216: packet_put_int(remote_port);
1217: }
1.51 markus 1218: packet_send();
1219: } else {
1220: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1221: packet_put_int(nc->self);
1.121 markus 1222: if (packet_get_protocol_flags() &
1223: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1224: packet_put_cstring(buf);
1.51 markus 1225: packet_send();
1226: }
1.85 markus 1227: xfree(remote_ipaddr);
1.41 markus 1228: }
1229: }
1.25 markus 1230:
1.127 itojun 1231: static void
1.103 markus 1232: port_open_helper(Channel *c, char *rtype)
1233: {
1234: int direct;
1235: char buf[1024];
1236: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1237: int remote_port = get_peer_port(c->sock);
1.103 markus 1238:
1239: direct = (strcmp(rtype, "direct-tcpip") == 0);
1240:
1241: snprintf(buf, sizeof buf,
1242: "%s: listening port %d for %.100s port %d, "
1243: "connect from %.200s port %d",
1244: rtype, c->listening_port, c->path, c->host_port,
1245: remote_ipaddr, remote_port);
1246:
1247: xfree(c->remote_name);
1248: c->remote_name = xstrdup(buf);
1249:
1250: if (compat20) {
1251: packet_start(SSH2_MSG_CHANNEL_OPEN);
1252: packet_put_cstring(rtype);
1253: packet_put_int(c->self);
1254: packet_put_int(c->local_window_max);
1255: packet_put_int(c->local_maxpacket);
1256: if (direct) {
1257: /* target host, port */
1258: packet_put_cstring(c->path);
1259: packet_put_int(c->host_port);
1260: } else {
1261: /* listen address, port */
1262: packet_put_cstring(c->path);
1263: packet_put_int(c->listening_port);
1264: }
1265: /* originator host and port */
1266: packet_put_cstring(remote_ipaddr);
1.216 markus 1267: packet_put_int((u_int)remote_port);
1.103 markus 1268: packet_send();
1269: } else {
1270: packet_start(SSH_MSG_PORT_OPEN);
1271: packet_put_int(c->self);
1272: packet_put_cstring(c->path);
1273: packet_put_int(c->host_port);
1.121 markus 1274: if (packet_get_protocol_flags() &
1275: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1276: packet_put_cstring(c->remote_name);
1277: packet_send();
1278: }
1279: xfree(remote_ipaddr);
1280: }
1281:
1.226 djm 1282: static void
1283: channel_set_reuseaddr(int fd)
1284: {
1285: int on = 1;
1286:
1287: /*
1288: * Set socket options.
1289: * Allow local port reuse in TIME_WAIT.
1290: */
1291: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1292: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1293: }
1294:
1.41 markus 1295: /*
1296: * This socket is listening for connections to a forwarded TCP/IP port.
1297: */
1.259 stevesk 1298: /* ARGSUSED */
1.127 itojun 1299: static void
1.237 deraadt 1300: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1301: {
1.103 markus 1302: Channel *nc;
1.41 markus 1303: struct sockaddr addr;
1.113 markus 1304: int newsock, nextstate;
1.41 markus 1305: socklen_t addrlen;
1.103 markus 1306: char *rtype;
1.73 markus 1307:
1.41 markus 1308: if (FD_ISSET(c->sock, readset)) {
1309: debug("Connection to port %d forwarding "
1310: "to %.100s port %d requested.",
1311: c->listening_port, c->path, c->host_port);
1.103 markus 1312:
1.137 markus 1313: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1314: nextstate = SSH_CHANNEL_OPENING;
1315: rtype = "forwarded-tcpip";
1316: } else {
1317: if (c->host_port == 0) {
1318: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1319: rtype = "dynamic-tcpip";
1.137 markus 1320: } else {
1321: nextstate = SSH_CHANNEL_OPENING;
1322: rtype = "direct-tcpip";
1323: }
1324: }
1.103 markus 1325:
1.41 markus 1326: addrlen = sizeof(addr);
1327: newsock = accept(c->sock, &addr, &addrlen);
1328: if (newsock < 0) {
1329: error("accept: %.100s", strerror(errno));
1330: return;
1331: }
1.169 stevesk 1332: set_nodelay(newsock);
1.190 markus 1333: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1334: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1335: nc->listening_port = c->listening_port;
1336: nc->host_port = c->host_port;
1337: strlcpy(nc->path, c->path, sizeof(nc->path));
1338:
1.137 markus 1339: if (nextstate == SSH_CHANNEL_DYNAMIC) {
1340: /*
1341: * do not call the channel_post handler until
1342: * this flag has been reset by a pre-handler.
1343: * otherwise the FD_ISSET calls might overflow
1344: */
1345: nc->delayed = 1;
1346: } else {
1.103 markus 1347: port_open_helper(nc, rtype);
1.137 markus 1348: }
1.41 markus 1349: }
1350: }
1.25 markus 1351:
1.41 markus 1352: /*
1353: * This is the authentication agent socket listening for connections from
1354: * clients.
1355: */
1.259 stevesk 1356: /* ARGSUSED */
1.127 itojun 1357: static void
1.237 deraadt 1358: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1359: {
1.113 markus 1360: Channel *nc;
1361: int newsock;
1.41 markus 1362: struct sockaddr addr;
1363: socklen_t addrlen;
1.25 markus 1364:
1.41 markus 1365: if (FD_ISSET(c->sock, readset)) {
1366: addrlen = sizeof(addr);
1367: newsock = accept(c->sock, &addr, &addrlen);
1368: if (newsock < 0) {
1369: error("accept from auth socket: %.100s", strerror(errno));
1370: return;
1371: }
1.113 markus 1372: nc = channel_new("accepted auth socket",
1.73 markus 1373: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1374: c->local_window_max, c->local_maxpacket,
1.190 markus 1375: 0, "accepted auth socket", 1);
1.73 markus 1376: if (compat20) {
1377: packet_start(SSH2_MSG_CHANNEL_OPEN);
1378: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1379: packet_put_int(nc->self);
1.73 markus 1380: packet_put_int(c->local_window_max);
1381: packet_put_int(c->local_maxpacket);
1382: } else {
1383: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1384: packet_put_int(nc->self);
1.73 markus 1385: }
1.41 markus 1386: packet_send();
1387: }
1388: }
1.25 markus 1389:
1.259 stevesk 1390: /* ARGSUSED */
1.127 itojun 1391: static void
1.237 deraadt 1392: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1393: {
1.114 markus 1394: int err = 0;
1.129 stevesk 1395: socklen_t sz = sizeof(err);
1.114 markus 1396:
1.75 markus 1397: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1398: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1399: err = errno;
1400: error("getsockopt SO_ERROR failed");
1401: }
1402: if (err == 0) {
1403: debug("channel %d: connected", c->self);
1404: c->type = SSH_CHANNEL_OPEN;
1405: if (compat20) {
1406: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1407: packet_put_int(c->remote_id);
1408: packet_put_int(c->self);
1409: packet_put_int(c->local_window);
1410: packet_put_int(c->local_maxpacket);
1411: } else {
1412: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1413: packet_put_int(c->remote_id);
1414: packet_put_int(c->self);
1415: }
1.75 markus 1416: } else {
1.114 markus 1417: debug("channel %d: not connected: %s",
1418: c->self, strerror(err));
1419: if (compat20) {
1420: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1421: packet_put_int(c->remote_id);
1422: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1423: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1424: packet_put_cstring(strerror(err));
1425: packet_put_cstring("");
1426: }
1.75 markus 1427: } else {
1.114 markus 1428: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1429: packet_put_int(c->remote_id);
1.75 markus 1430: }
1.114 markus 1431: chan_mark_dead(c);
1.75 markus 1432: }
1.114 markus 1433: packet_send();
1.75 markus 1434: }
1435: }
1436:
1.259 stevesk 1437: /* ARGSUSED */
1.127 itojun 1438: static int
1.237 deraadt 1439: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1440: {
1.214 markus 1441: char buf[CHAN_RBUF];
1.41 markus 1442: int len;
1.25 markus 1443:
1.118 markus 1444: if (c->rfd != -1 &&
1.41 markus 1445: FD_ISSET(c->rfd, readset)) {
1446: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1447: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1448: return 1;
1.41 markus 1449: if (len <= 0) {
1.194 markus 1450: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1451: c->self, c->rfd, len);
1.104 markus 1452: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1453: debug2("channel %d: not open", c->self);
1.113 markus 1454: chan_mark_dead(c);
1.103 markus 1455: return -1;
1.104 markus 1456: } else if (compat13) {
1.158 markus 1457: buffer_clear(&c->output);
1.41 markus 1458: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1459: debug2("channel %d: input draining.", c->self);
1.25 markus 1460: } else {
1.41 markus 1461: chan_read_failed(c);
1.25 markus 1462: }
1.41 markus 1463: return -1;
1464: }
1.143 deraadt 1465: if (c->input_filter != NULL) {
1.66 markus 1466: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1467: debug2("channel %d: filter stops", c->self);
1.65 markus 1468: chan_read_failed(c);
1469: }
1.228 reyk 1470: } else if (c->datagram) {
1471: buffer_put_string(&c->input, buf, len);
1.65 markus 1472: } else {
1473: buffer_append(&c->input, buf, len);
1474: }
1.41 markus 1475: }
1476: return 1;
1477: }
1.241 deraadt 1478:
1.259 stevesk 1479: /* ARGSUSED */
1.127 itojun 1480: static int
1.237 deraadt 1481: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1482: {
1.95 markus 1483: struct termios tio;
1.231 reyk 1484: u_char *data = NULL, *buf;
1.134 markus 1485: u_int dlen;
1.41 markus 1486: int len;
1.25 markus 1487:
1.41 markus 1488: /* Send buffered output data to the socket. */
1.118 markus 1489: if (c->wfd != -1 &&
1.41 markus 1490: FD_ISSET(c->wfd, writeset) &&
1491: buffer_len(&c->output) > 0) {
1.231 reyk 1492: if (c->output_filter != NULL) {
1493: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1494: debug2("channel %d: filter stops", c->self);
1.232 reyk 1495: if (c->type != SSH_CHANNEL_OPEN)
1496: chan_mark_dead(c);
1497: else
1498: chan_write_failed(c);
1499: return -1;
1.231 reyk 1500: }
1501: } else if (c->datagram) {
1502: buf = data = buffer_get_string(&c->output, &dlen);
1503: } else {
1504: buf = data = buffer_ptr(&c->output);
1505: dlen = buffer_len(&c->output);
1506: }
1507:
1.228 reyk 1508: if (c->datagram) {
1509: /* ignore truncated writes, datagrams might get lost */
1510: c->local_consumed += dlen + 4;
1.231 reyk 1511: len = write(c->wfd, buf, dlen);
1.228 reyk 1512: xfree(data);
1513: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1514: return 1;
1515: if (len <= 0) {
1516: if (c->type != SSH_CHANNEL_OPEN)
1517: chan_mark_dead(c);
1518: else
1519: chan_write_failed(c);
1520: return -1;
1521: }
1522: return 1;
1523: }
1.231 reyk 1524:
1525: len = write(c->wfd, buf, dlen);
1.53 markus 1526: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1527: return 1;
1.41 markus 1528: if (len <= 0) {
1.104 markus 1529: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1530: debug2("channel %d: not open", c->self);
1.113 markus 1531: chan_mark_dead(c);
1.104 markus 1532: return -1;
1533: } else if (compat13) {
1.158 markus 1534: buffer_clear(&c->output);
1.194 markus 1535: debug2("channel %d: input draining.", c->self);
1.41 markus 1536: c->type = SSH_CHANNEL_INPUT_DRAINING;
1537: } else {
1538: chan_write_failed(c);
1539: }
1540: return -1;
1.91 markus 1541: }
1.231 reyk 1542: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1543: if (tcgetattr(c->wfd, &tio) == 0 &&
1544: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1545: /*
1546: * Simulate echo to reduce the impact of
1.96 markus 1547: * traffic analysis. We need to match the
1.95 markus 1548: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1549: * (4 byte channel id + buf)
1.91 markus 1550: */
1.95 markus 1551: packet_send_ignore(4 + len);
1.91 markus 1552: packet_send();
1553: }
1.25 markus 1554: }
1.41 markus 1555: buffer_consume(&c->output, len);
1.44 markus 1556: if (compat20 && len > 0) {
1557: c->local_consumed += len;
1558: }
1559: }
1560: return 1;
1561: }
1.241 deraadt 1562:
1.127 itojun 1563: static int
1.237 deraadt 1564: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1565: {
1.214 markus 1566: char buf[CHAN_RBUF];
1.44 markus 1567: int len;
1568:
1.45 markus 1569: /** XXX handle drain efd, too */
1.44 markus 1570: if (c->efd != -1) {
1571: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1572: FD_ISSET(c->efd, writeset) &&
1573: buffer_len(&c->extended) > 0) {
1574: len = write(c->efd, buffer_ptr(&c->extended),
1575: buffer_len(&c->extended));
1.70 markus 1576: debug2("channel %d: written %d to efd %d",
1.44 markus 1577: c->self, len, c->efd);
1.93 markus 1578: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1579: return 1;
1580: if (len <= 0) {
1581: debug2("channel %d: closing write-efd %d",
1582: c->self, c->efd);
1.132 markus 1583: channel_close_fd(&c->efd);
1.93 markus 1584: } else {
1.44 markus 1585: buffer_consume(&c->extended, len);
1586: c->local_consumed += len;
1587: }
1588: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1589: FD_ISSET(c->efd, readset)) {
1590: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1591: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1592: c->self, len, c->efd);
1.93 markus 1593: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1594: return 1;
1595: if (len <= 0) {
1596: debug2("channel %d: closing read-efd %d",
1.45 markus 1597: c->self, c->efd);
1.132 markus 1598: channel_close_fd(&c->efd);
1.93 markus 1599: } else {
1.44 markus 1600: buffer_append(&c->extended, buf, len);
1.93 markus 1601: }
1.44 markus 1602: }
1603: }
1604: return 1;
1605: }
1.241 deraadt 1606:
1.259 stevesk 1607: /* ARGSUSED */
1.127 itojun 1608: static int
1.237 deraadt 1609: channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
1.204 djm 1610: {
1611: char buf[16];
1612: int len;
1613:
1614: /* Monitor control fd to detect if the slave client exits */
1615: if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1616: len = read(c->ctl_fd, buf, sizeof(buf));
1617: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1618: return 1;
1619: if (len <= 0) {
1620: debug2("channel %d: ctl read<=0", c->self);
1621: if (c->type != SSH_CHANNEL_OPEN) {
1622: debug2("channel %d: not open", c->self);
1623: chan_mark_dead(c);
1624: return -1;
1625: } else {
1626: chan_read_failed(c);
1627: chan_write_failed(c);
1628: }
1629: return -1;
1630: } else
1631: fatal("%s: unexpected data on ctl fd", __func__);
1632: }
1633: return 1;
1634: }
1.241 deraadt 1635:
1.204 djm 1636: static int
1.93 markus 1637: channel_check_window(Channel *c)
1.44 markus 1638: {
1.104 markus 1639: if (c->type == SSH_CHANNEL_OPEN &&
1640: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1641: c->local_window < c->local_window_max/2 &&
1642: c->local_consumed > 0) {
1643: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1644: packet_put_int(c->remote_id);
1645: packet_put_int(c->local_consumed);
1646: packet_send();
1.70 markus 1647: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1648: c->self, c->local_window,
1649: c->local_consumed);
1650: c->local_window += c->local_consumed;
1651: c->local_consumed = 0;
1.1 deraadt 1652: }
1.41 markus 1653: return 1;
1.1 deraadt 1654: }
1655:
1.127 itojun 1656: static void
1.237 deraadt 1657: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1658: {
1.137 markus 1659: if (c->delayed)
1660: return;
1.41 markus 1661: channel_handle_rfd(c, readset, writeset);
1662: channel_handle_wfd(c, readset, writeset);
1.157 markus 1663: if (!compat20)
1.137 markus 1664: return;
1.44 markus 1665: channel_handle_efd(c, readset, writeset);
1.204 djm 1666: channel_handle_ctl(c, readset, writeset);
1.93 markus 1667: channel_check_window(c);
1.44 markus 1668: }
1669:
1.259 stevesk 1670: /* ARGSUSED */
1.127 itojun 1671: static void
1.237 deraadt 1672: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1673: {
1.41 markus 1674: int len;
1.180 deraadt 1675:
1.41 markus 1676: /* Send buffered output data to the socket. */
1677: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1678: len = write(c->sock, buffer_ptr(&c->output),
1679: buffer_len(&c->output));
1680: if (len <= 0)
1.158 markus 1681: buffer_clear(&c->output);
1.41 markus 1682: else
1683: buffer_consume(&c->output, len);
1684: }
1685: }
1.25 markus 1686:
1.127 itojun 1687: static void
1.44 markus 1688: channel_handler_init_20(void)
1689: {
1.157 markus 1690: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1691: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1692: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1693: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1694: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1695: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1696: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1697: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1698:
1.157 markus 1699: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1700: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1701: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1702: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1703: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1704: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1705: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.44 markus 1706: }
1707:
1.127 itojun 1708: static void
1.41 markus 1709: channel_handler_init_13(void)
1710: {
1711: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1712: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1713: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1714: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1715: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1716: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1717: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1718: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1719: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1720:
1.157 markus 1721: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1722: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1723: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1724: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1725: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1726: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1727: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1728: }
1.25 markus 1729:
1.127 itojun 1730: static void
1.41 markus 1731: channel_handler_init_15(void)
1732: {
1.157 markus 1733: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1734: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1735: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1736: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1737: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1738: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1739: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1740:
1.41 markus 1741: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1742: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1743: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 1744: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 1745: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1746: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1747: }
1.27 markus 1748:
1.127 itojun 1749: static void
1.41 markus 1750: channel_handler_init(void)
1751: {
1752: int i;
1.180 deraadt 1753:
1.148 deraadt 1754: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 1755: channel_pre[i] = NULL;
1756: channel_post[i] = NULL;
1757: }
1.44 markus 1758: if (compat20)
1759: channel_handler_init_20();
1760: else if (compat13)
1.41 markus 1761: channel_handler_init_13();
1762: else
1763: channel_handler_init_15();
1764: }
1.25 markus 1765:
1.140 markus 1766: /* gc dead channels */
1767: static void
1768: channel_garbage_collect(Channel *c)
1769: {
1770: if (c == NULL)
1771: return;
1772: if (c->detach_user != NULL) {
1.225 djm 1773: if (!chan_is_dead(c, c->detach_close))
1.140 markus 1774: return;
1.194 markus 1775: debug2("channel %d: gc: notify user", c->self);
1.140 markus 1776: c->detach_user(c->self, NULL);
1777: /* if we still have a callback */
1778: if (c->detach_user != NULL)
1779: return;
1.194 markus 1780: debug2("channel %d: gc: user detached", c->self);
1.140 markus 1781: }
1782: if (!chan_is_dead(c, 1))
1783: return;
1.194 markus 1784: debug2("channel %d: garbage collecting", c->self);
1.140 markus 1785: channel_free(c);
1786: }
1787:
1.127 itojun 1788: static void
1.237 deraadt 1789: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 1790: {
1791: static int did_init = 0;
1.209 avsm 1792: u_int i;
1.41 markus 1793: Channel *c;
1.25 markus 1794:
1.41 markus 1795: if (!did_init) {
1796: channel_handler_init();
1797: did_init = 1;
1798: }
1799: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1800: c = channels[i];
1801: if (c == NULL)
1.41 markus 1802: continue;
1.118 markus 1803: if (ftab[c->type] != NULL)
1804: (*ftab[c->type])(c, readset, writeset);
1.140 markus 1805: channel_garbage_collect(c);
1.1 deraadt 1806: }
1807: }
1808:
1.121 markus 1809: /*
1810: * Allocate/update select bitmasks and add any bits relevant to channels in
1811: * select bitmasks.
1812: */
1.49 markus 1813: void
1.100 markus 1814: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 1815: u_int *nallocp, int rekeying)
1.41 markus 1816: {
1.243 djm 1817: u_int n, sz, nfdset;
1.84 markus 1818:
1819: n = MAX(*maxfdp, channel_max_fd);
1820:
1.243 djm 1821: nfdset = howmany(n+1, NFDBITS);
1822: /* Explicitly test here, because xrealloc isn't always called */
1823: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1824: fatal("channel_prepare_select: max_fd (%d) is too large", n);
1825: sz = nfdset * sizeof(fd_mask);
1826:
1.132 markus 1827: /* perhaps check sz < nalloc/2 and shrink? */
1828: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 1829: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1830: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 1831: *nallocp = sz;
1.84 markus 1832: }
1.132 markus 1833: *maxfdp = n;
1.84 markus 1834: memset(*readsetp, 0, sz);
1835: memset(*writesetp, 0, sz);
1836:
1.100 markus 1837: if (!rekeying)
1838: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1839: }
1840:
1.121 markus 1841: /*
1842: * After select, perform any appropriate operations for channels which have
1843: * events pending.
1844: */
1.49 markus 1845: void
1.237 deraadt 1846: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 1847: {
1848: channel_handler(channel_post, readset, writeset);
1849: }
1850:
1.121 markus 1851:
1.84 markus 1852: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 1853: void
1.142 itojun 1854: channel_output_poll(void)
1.1 deraadt 1855: {
1.41 markus 1856: Channel *c;
1.209 avsm 1857: u_int i, len;
1.1 deraadt 1858:
1.25 markus 1859: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1860: c = channels[i];
1861: if (c == NULL)
1862: continue;
1.37 markus 1863:
1.121 markus 1864: /*
1865: * We are only interested in channels that can have buffered
1866: * incoming data.
1867: */
1.37 markus 1868: if (compat13) {
1.41 markus 1869: if (c->type != SSH_CHANNEL_OPEN &&
1870: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1871: continue;
1872: } else {
1.41 markus 1873: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1874: continue;
1875: }
1.46 markus 1876: if (compat20 &&
1877: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1878: /* XXX is this true? */
1.140 markus 1879: debug3("channel %d: will not send data after close", c->self);
1.44 markus 1880: continue;
1881: }
1.25 markus 1882:
1883: /* Get the amount of buffered data for this channel. */
1.93 markus 1884: if ((c->istate == CHAN_INPUT_OPEN ||
1885: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1886: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 1887: if (c->datagram) {
1888: if (len > 0) {
1889: u_char *data;
1890: u_int dlen;
1891:
1892: data = buffer_get_string(&c->input,
1893: &dlen);
1894: packet_start(SSH2_MSG_CHANNEL_DATA);
1895: packet_put_int(c->remote_id);
1896: packet_put_string(data, dlen);
1897: packet_send();
1898: c->remote_window -= dlen + 4;
1899: xfree(data);
1900: }
1901: continue;
1902: }
1.121 markus 1903: /*
1904: * Send some data for the other side over the secure
1905: * connection.
1906: */
1.44 markus 1907: if (compat20) {
1908: if (len > c->remote_window)
1909: len = c->remote_window;
1910: if (len > c->remote_maxpacket)
1911: len = c->remote_maxpacket;
1.25 markus 1912: } else {
1.44 markus 1913: if (packet_is_interactive()) {
1914: if (len > 1024)
1915: len = 512;
1916: } else {
1917: /* Keep the packets at reasonable size. */
1918: if (len > packet_get_maxsize()/2)
1919: len = packet_get_maxsize()/2;
1920: }
1.25 markus 1921: }
1.41 markus 1922: if (len > 0) {
1.44 markus 1923: packet_start(compat20 ?
1924: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1925: packet_put_int(c->remote_id);
1926: packet_put_string(buffer_ptr(&c->input), len);
1927: packet_send();
1928: buffer_consume(&c->input, len);
1929: c->remote_window -= len;
1930: }
1931: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1932: if (compat13)
1933: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1934: /*
1935: * input-buffer is empty and read-socket shutdown:
1.172 markus 1936: * tell peer, that we will not send more data: send IEOF.
1937: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 1938: */
1.172 markus 1939: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 1940: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1941: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 1942: else
1943: chan_ibuf_empty(c);
1.25 markus 1944: }
1.44 markus 1945: /* Send extended data, i.e. stderr */
1946: if (compat20 &&
1.172 markus 1947: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 1948: c->remote_window > 0 &&
1949: (len = buffer_len(&c->extended)) > 0 &&
1950: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 1951: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 1952: c->self, c->remote_window, buffer_len(&c->extended),
1953: c->extended_usage);
1.44 markus 1954: if (len > c->remote_window)
1955: len = c->remote_window;
1956: if (len > c->remote_maxpacket)
1957: len = c->remote_maxpacket;
1958: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1959: packet_put_int(c->remote_id);
1960: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1961: packet_put_string(buffer_ptr(&c->extended), len);
1962: packet_send();
1963: buffer_consume(&c->extended, len);
1964: c->remote_window -= len;
1.93 markus 1965: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1966: }
1.25 markus 1967: }
1.1 deraadt 1968: }
1969:
1.121 markus 1970:
1971: /* -- protocol input */
1.249 djm 1972:
1973: /* ARGSUSED */
1.49 markus 1974: void
1.154 markus 1975: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 1976: {
1.37 markus 1977: int id;
1.25 markus 1978: char *data;
1.77 markus 1979: u_int data_len;
1.41 markus 1980: Channel *c;
1.25 markus 1981:
1982: /* Get the channel number and verify it. */
1.37 markus 1983: id = packet_get_int();
1.41 markus 1984: c = channel_lookup(id);
1985: if (c == NULL)
1.37 markus 1986: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1987:
1988: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1989: if (c->type != SSH_CHANNEL_OPEN &&
1990: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1991: return;
1992:
1.25 markus 1993: /* Get the data. */
1994: data = packet_get_string(&data_len);
1.200 markus 1995:
1996: /*
1997: * Ignore data for protocol > 1.3 if output end is no longer open.
1998: * For protocol 2 the sending side is reducing its window as it sends
1999: * data, so we must 'fake' consumption of the data in order to ensure
2000: * that window updates are sent back. Otherwise the connection might
2001: * deadlock.
2002: */
2003: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2004: if (compat20) {
2005: c->local_window -= data_len;
2006: c->local_consumed += data_len;
2007: }
2008: xfree(data);
2009: return;
2010: }
1.41 markus 2011:
1.143 deraadt 2012: if (compat20) {
1.44 markus 2013: if (data_len > c->local_maxpacket) {
1.188 itojun 2014: logit("channel %d: rcvd big packet %d, maxpack %d",
1.44 markus 2015: c->self, data_len, c->local_maxpacket);
2016: }
2017: if (data_len > c->local_window) {
1.188 itojun 2018: logit("channel %d: rcvd too much data %d, win %d",
1.44 markus 2019: c->self, data_len, c->local_window);
2020: xfree(data);
2021: return;
2022: }
2023: c->local_window -= data_len;
2024: }
1.152 markus 2025: packet_check_eom();
1.228 reyk 2026: if (c->datagram)
2027: buffer_put_string(&c->output, data, data_len);
2028: else
2029: buffer_append(&c->output, data, data_len);
1.25 markus 2030: xfree(data);
1.1 deraadt 2031: }
1.121 markus 2032:
1.249 djm 2033: /* ARGSUSED */
1.49 markus 2034: void
1.154 markus 2035: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2036: {
2037: int id;
2038: char *data;
1.177 markus 2039: u_int data_len, tcode;
1.44 markus 2040: Channel *c;
2041:
2042: /* Get the channel number and verify it. */
2043: id = packet_get_int();
2044: c = channel_lookup(id);
2045:
2046: if (c == NULL)
2047: packet_disconnect("Received extended_data for bad channel %d.", id);
2048: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2049: logit("channel %d: ext data for non open", id);
1.44 markus 2050: return;
1.172 markus 2051: }
2052: if (c->flags & CHAN_EOF_RCVD) {
2053: if (datafellows & SSH_BUG_EXTEOF)
2054: debug("channel %d: accepting ext data after eof", id);
2055: else
2056: packet_disconnect("Received extended_data after EOF "
2057: "on channel %d.", id);
1.44 markus 2058: }
2059: tcode = packet_get_int();
2060: if (c->efd == -1 ||
2061: c->extended_usage != CHAN_EXTENDED_WRITE ||
2062: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2063: logit("channel %d: bad ext data", c->self);
1.44 markus 2064: return;
2065: }
2066: data = packet_get_string(&data_len);
1.152 markus 2067: packet_check_eom();
1.44 markus 2068: if (data_len > c->local_window) {
1.188 itojun 2069: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2070: c->self, data_len, c->local_window);
2071: xfree(data);
2072: return;
2073: }
1.70 markus 2074: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2075: c->local_window -= data_len;
2076: buffer_append(&c->extended, data, data_len);
2077: xfree(data);
2078: }
2079:
1.249 djm 2080: /* ARGSUSED */
1.49 markus 2081: void
1.154 markus 2082: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2083: {
2084: int id;
2085: Channel *c;
2086:
2087: id = packet_get_int();
1.152 markus 2088: packet_check_eom();
1.41 markus 2089: c = channel_lookup(id);
2090: if (c == NULL)
2091: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2092: chan_rcvd_ieof(c);
1.133 markus 2093:
2094: /* XXX force input close */
1.156 markus 2095: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2096: debug("channel %d: FORCE input drain", c->self);
2097: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2098: if (buffer_len(&c->input) == 0)
2099: chan_ibuf_empty(c);
1.133 markus 2100: }
2101:
1.41 markus 2102: }
1.1 deraadt 2103:
1.249 djm 2104: /* ARGSUSED */
1.49 markus 2105: void
1.154 markus 2106: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2107: {
1.41 markus 2108: int id;
2109: Channel *c;
1.1 deraadt 2110:
1.41 markus 2111: id = packet_get_int();
1.152 markus 2112: packet_check_eom();
1.41 markus 2113: c = channel_lookup(id);
2114: if (c == NULL)
2115: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2116:
2117: /*
2118: * Send a confirmation that we have closed the channel and no more
2119: * data is coming for it.
2120: */
1.25 markus 2121: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2122: packet_put_int(c->remote_id);
1.25 markus 2123: packet_send();
2124:
1.27 markus 2125: /*
2126: * If the channel is in closed state, we have sent a close request,
2127: * and the other side will eventually respond with a confirmation.
2128: * Thus, we cannot free the channel here, because then there would be
2129: * no-one to receive the confirmation. The channel gets freed when
2130: * the confirmation arrives.
2131: */
1.41 markus 2132: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2133: /*
2134: * Not a closed channel - mark it as draining, which will
2135: * cause it to be freed later.
2136: */
1.158 markus 2137: buffer_clear(&c->input);
1.41 markus 2138: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2139: }
1.1 deraadt 2140: }
2141:
1.41 markus 2142: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2143: /* ARGSUSED */
1.49 markus 2144: void
1.154 markus 2145: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2146: {
2147: int id = packet_get_int();
2148: Channel *c = channel_lookup(id);
1.151 markus 2149:
1.152 markus 2150: packet_check_eom();
1.41 markus 2151: if (c == NULL)
2152: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2153: chan_rcvd_oclose(c);
2154: }
1.1 deraadt 2155:
1.249 djm 2156: /* ARGSUSED */
1.49 markus 2157: void
1.154 markus 2158: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2159: {
1.41 markus 2160: int id = packet_get_int();
2161: Channel *c = channel_lookup(id);
1.1 deraadt 2162:
1.152 markus 2163: packet_check_eom();
1.41 markus 2164: if (c == NULL)
2165: packet_disconnect("Received close confirmation for "
2166: "out-of-range channel %d.", id);
2167: if (c->type != SSH_CHANNEL_CLOSED)
2168: packet_disconnect("Received close confirmation for "
2169: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2170: channel_free(c);
1.1 deraadt 2171: }
2172:
1.249 djm 2173: /* ARGSUSED */
1.49 markus 2174: void
1.154 markus 2175: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2176: {
1.41 markus 2177: int id, remote_id;
2178: Channel *c;
1.1 deraadt 2179:
1.41 markus 2180: id = packet_get_int();
2181: c = channel_lookup(id);
1.25 markus 2182:
1.41 markus 2183: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2184: packet_disconnect("Received open confirmation for "
2185: "non-opening channel %d.", id);
2186: remote_id = packet_get_int();
1.27 markus 2187: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2188: c->remote_id = remote_id;
2189: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2190:
2191: if (compat20) {
2192: c->remote_window = packet_get_int();
2193: c->remote_maxpacket = packet_get_int();
1.165 markus 2194: if (c->confirm) {
1.70 markus 2195: debug2("callback start");
1.204 djm 2196: c->confirm(c->self, c->confirm_ctx);
1.70 markus 2197: debug2("callback done");
1.44 markus 2198: }
1.194 markus 2199: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2200: c->remote_window, c->remote_maxpacket);
2201: }
1.152 markus 2202: packet_check_eom();
1.1 deraadt 2203: }
2204:
1.127 itojun 2205: static char *
1.114 markus 2206: reason2txt(int reason)
2207: {
1.143 deraadt 2208: switch (reason) {
1.114 markus 2209: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2210: return "administratively prohibited";
2211: case SSH2_OPEN_CONNECT_FAILED:
2212: return "connect failed";
2213: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2214: return "unknown channel type";
2215: case SSH2_OPEN_RESOURCE_SHORTAGE:
2216: return "resource shortage";
2217: }
1.117 stevesk 2218: return "unknown reason";
1.114 markus 2219: }
2220:
1.249 djm 2221: /* ARGSUSED */
1.49 markus 2222: void
1.154 markus 2223: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2224: {
1.86 markus 2225: int id, reason;
2226: char *msg = NULL, *lang = NULL;
1.41 markus 2227: Channel *c;
2228:
2229: id = packet_get_int();
2230: c = channel_lookup(id);
1.25 markus 2231:
1.41 markus 2232: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2233: packet_disconnect("Received open failure for "
2234: "non-opening channel %d.", id);
1.44 markus 2235: if (compat20) {
1.86 markus 2236: reason = packet_get_int();
1.110 markus 2237: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2238: msg = packet_get_string(NULL);
2239: lang = packet_get_string(NULL);
2240: }
1.188 itojun 2241: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2242: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2243: if (msg != NULL)
2244: xfree(msg);
2245: if (lang != NULL)
2246: xfree(lang);
1.44 markus 2247: }
1.152 markus 2248: packet_check_eom();
1.25 markus 2249: /* Free the channel. This will also close the socket. */
1.113 markus 2250: channel_free(c);
1.44 markus 2251: }
2252:
1.249 djm 2253: /* ARGSUSED */
1.121 markus 2254: void
1.154 markus 2255: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2256: {
2257: Channel *c;
1.178 markus 2258: int id;
2259: u_int adjust;
1.121 markus 2260:
2261: if (!compat20)
2262: return;
2263:
2264: /* Get the channel number and verify it. */
2265: id = packet_get_int();
2266: c = channel_lookup(id);
1.1 deraadt 2267:
1.229 markus 2268: if (c == NULL) {
2269: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2270: return;
2271: }
2272: adjust = packet_get_int();
1.152 markus 2273: packet_check_eom();
1.178 markus 2274: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2275: c->remote_window += adjust;
2276: }
1.1 deraadt 2277:
1.249 djm 2278: /* ARGSUSED */
1.121 markus 2279: void
1.154 markus 2280: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2281: {
1.121 markus 2282: Channel *c = NULL;
2283: u_short host_port;
2284: char *host, *originator_string;
2285: int remote_id, sock = -1;
2286:
2287: remote_id = packet_get_int();
2288: host = packet_get_string(NULL);
2289: host_port = packet_get_int();
1.25 markus 2290:
1.121 markus 2291: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2292: originator_string = packet_get_string(NULL);
2293: } else {
2294: originator_string = xstrdup("unknown (remote did not supply name)");
2295: }
1.152 markus 2296: packet_check_eom();
1.121 markus 2297: sock = channel_connect_to(host, host_port);
2298: if (sock != -1) {
2299: c = channel_new("connected socket",
2300: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2301: originator_string, 1);
1.167 markus 2302: c->remote_id = remote_id;
1.25 markus 2303: }
1.190 markus 2304: xfree(originator_string);
1.121 markus 2305: if (c == NULL) {
2306: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2307: packet_put_int(remote_id);
2308: packet_send();
2309: }
2310: xfree(host);
1.1 deraadt 2311: }
2312:
1.121 markus 2313:
2314: /* -- tcp forwarding */
1.135 markus 2315:
2316: void
2317: channel_set_af(int af)
2318: {
2319: IPv4or6 = af;
2320: }
1.121 markus 2321:
1.160 markus 2322: static int
2323: channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2324: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2325: {
1.113 markus 2326: Channel *c;
1.226 djm 2327: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2328: struct addrinfo hints, *ai, *aitop;
1.212 djm 2329: const char *host, *addr;
1.35 markus 2330: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.25 markus 2331:
1.160 markus 2332: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2333: listen_addr : host_to_connect;
1.212 djm 2334: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2335:
1.160 markus 2336: if (host == NULL) {
2337: error("No forward host name.");
1.218 markus 2338: return 0;
1.73 markus 2339: }
1.113 markus 2340: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 2341: error("Forward host name too long.");
1.218 markus 2342: return 0;
1.87 markus 2343: }
1.25 markus 2344:
1.28 markus 2345: /*
1.212 djm 2346: * Determine whether or not a port forward listens to loopback,
1.213 deraadt 2347: * specified address or wildcard. On the client, a specified bind
2348: * address will always override gateway_ports. On the server, a
2349: * gateway_ports of 1 (``yes'') will override the client's
2350: * specification and force a wildcard bind, whereas a value of 2
2351: * (``clientspecified'') will bind to whatever address the client
1.212 djm 2352: * asked for.
2353: *
2354: * Special-case listen_addrs are:
2355: *
2356: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2357: * "" (empty string), "*" -> wildcard v4/v6
2358: * "localhost" -> loopback v4/v6
2359: */
2360: addr = NULL;
2361: if (listen_addr == NULL) {
2362: /* No address specified: default to gateway_ports setting */
2363: if (gateway_ports)
2364: wildcard = 1;
2365: } else if (gateway_ports || is_client) {
2366: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2367: strcmp(listen_addr, "0.0.0.0") == 0) ||
2368: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2369: (!is_client && gateway_ports == 1))
2370: wildcard = 1;
2371: else if (strcmp(listen_addr, "localhost") != 0)
2372: addr = listen_addr;
2373: }
2374:
2375: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2376: type, wildcard, (addr == NULL) ? "NULL" : addr);
2377:
2378: /*
1.35 markus 2379: * getaddrinfo returns a loopback address if the hostname is
2380: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2381: */
1.35 markus 2382: memset(&hints, 0, sizeof(hints));
2383: hints.ai_family = IPv4or6;
1.212 djm 2384: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2385: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2386: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2387: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2388: if (addr == NULL) {
2389: /* This really shouldn't happen */
2390: packet_disconnect("getaddrinfo: fatal error: %s",
2391: gai_strerror(r));
2392: } else {
1.218 markus 2393: error("channel_setup_fwd_listener: "
1.212 djm 2394: "getaddrinfo(%.64s): %s", addr, gai_strerror(r));
2395: }
1.218 markus 2396: return 0;
1.212 djm 2397: }
1.35 markus 2398:
2399: for (ai = aitop; ai; ai = ai->ai_next) {
2400: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2401: continue;
2402: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2403: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2404: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2405: continue;
2406: }
2407: /* Create a port to listen for the host. */
1.189 markus 2408: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2409: if (sock < 0) {
2410: /* this is no error since kernel may not support ipv6 */
2411: verbose("socket: %.100s", strerror(errno));
2412: continue;
2413: }
1.226 djm 2414:
2415: channel_set_reuseaddr(sock);
1.182 stevesk 2416:
1.35 markus 2417: debug("Local forwarding listening on %s port %s.", ntop, strport);
2418:
2419: /* Bind the socket to the address. */
2420: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2421: /* address can be in use ipv6 address is already bound */
2422: verbose("bind: %.100s", strerror(errno));
2423: close(sock);
2424: continue;
2425: }
2426: /* Start listening for connections on the socket. */
1.199 markus 2427: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2428: error("listen: %.100s", strerror(errno));
2429: close(sock);
2430: continue;
2431: }
2432: /* Allocate a channel number for the socket. */
1.121 markus 2433: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2434: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2435: 0, "port listener", 1);
1.113 markus 2436: strlcpy(c->path, host, sizeof(c->path));
2437: c->host_port = port_to_connect;
2438: c->listening_port = listen_port;
1.35 markus 2439: success = 1;
2440: }
2441: if (success == 0)
1.160 markus 2442: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2443: listen_port);
1.35 markus 2444: freeaddrinfo(aitop);
1.87 markus 2445: return success;
1.25 markus 2446: }
1.1 deraadt 2447:
1.202 djm 2448: int
2449: channel_cancel_rport_listener(const char *host, u_short port)
2450: {
1.209 avsm 2451: u_int i;
2452: int found = 0;
1.202 djm 2453:
1.213 deraadt 2454: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2455: Channel *c = channels[i];
2456:
2457: if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2458: strncmp(c->path, host, sizeof(c->path)) == 0 &&
1.208 deraadt 2459: c->listening_port == port) {
1.210 djm 2460: debug2("%s: close channel %d", __func__, i);
1.202 djm 2461: channel_free(c);
2462: found = 1;
2463: }
2464: }
2465:
2466: return (found);
2467: }
2468:
1.160 markus 2469: /* protocol local port fwd, used by ssh (and sshd in v1) */
2470: int
1.212 djm 2471: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2472: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2473: {
2474: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.212 djm 2475: listen_host, listen_port, host_to_connect, port_to_connect,
2476: gateway_ports);
1.160 markus 2477: }
2478:
2479: /* protocol v2 remote port fwd, used by sshd */
2480: int
2481: channel_setup_remote_fwd_listener(const char *listen_address,
2482: u_short listen_port, int gateway_ports)
2483: {
2484: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2485: listen_address, listen_port, NULL, 0, gateway_ports);
2486: }
2487:
1.27 markus 2488: /*
2489: * Initiate forwarding of connections to port "port" on remote host through
2490: * the secure channel to host:port from local side.
2491: */
1.1 deraadt 2492:
1.253 markus 2493: int
1.212 djm 2494: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2495: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2496: {
1.153 markus 2497: int type, success = 0;
1.73 markus 2498:
1.25 markus 2499: /* Record locally that connection to this host/port is permitted. */
2500: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2501: fatal("channel_request_remote_forwarding: too many forwards");
2502:
2503: /* Send the forward request to the remote side. */
1.44 markus 2504: if (compat20) {
1.212 djm 2505: const char *address_to_bind;
2506: if (listen_host == NULL)
2507: address_to_bind = "localhost";
2508: else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
2509: address_to_bind = "";
2510: else
2511: address_to_bind = listen_host;
2512:
1.44 markus 2513: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2514: packet_put_cstring("tcpip-forward");
1.173 markus 2515: packet_put_char(1); /* boolean: want reply */
1.44 markus 2516: packet_put_cstring(address_to_bind);
2517: packet_put_int(listen_port);
1.73 markus 2518: packet_send();
2519: packet_write_wait();
2520: /* Assume that server accepts the request */
2521: success = 1;
1.44 markus 2522: } else {
2523: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2524: packet_put_int(listen_port);
2525: packet_put_cstring(host_to_connect);
1.44 markus 2526: packet_put_int(port_to_connect);
2527: packet_send();
2528: packet_write_wait();
1.73 markus 2529:
2530: /* Wait for response from the remote side. */
1.153 markus 2531: type = packet_read();
1.73 markus 2532: switch (type) {
2533: case SSH_SMSG_SUCCESS:
2534: success = 1;
2535: break;
2536: case SSH_SMSG_FAILURE:
2537: break;
2538: default:
2539: /* Unknown packet */
2540: packet_disconnect("Protocol error for port forward request:"
2541: "received packet type %d.", type);
2542: }
2543: }
2544: if (success) {
2545: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2546: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2547: permitted_opens[num_permitted_opens].listen_port = listen_port;
2548: num_permitted_opens++;
1.44 markus 2549: }
1.253 markus 2550: return (success ? 0 : -1);
1.1 deraadt 2551: }
2552:
1.27 markus 2553: /*
1.208 deraadt 2554: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2555: * local side.
2556: */
2557: void
1.212 djm 2558: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2559: {
2560: int i;
2561:
2562: if (!compat20)
2563: return;
2564:
2565: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2566: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2567: permitted_opens[i].listen_port == port)
2568: break;
2569: }
2570: if (i >= num_permitted_opens) {
2571: debug("%s: requested forward not found", __func__);
2572: return;
2573: }
2574: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2575: packet_put_cstring("cancel-tcpip-forward");
2576: packet_put_char(0);
1.212 djm 2577: packet_put_cstring(host == NULL ? "" : host);
1.202 djm 2578: packet_put_int(port);
2579: packet_send();
2580:
2581: permitted_opens[i].listen_port = 0;
2582: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2583: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2584: permitted_opens[i].host_to_connect = NULL;
2585: }
2586:
2587: /*
1.27 markus 2588: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2589: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2590: * message if there was an error).
1.27 markus 2591: */
1.253 markus 2592: int
1.56 markus 2593: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2594: {
1.31 markus 2595: u_short port, host_port;
1.253 markus 2596: int success = 0;
1.25 markus 2597: char *hostname;
1.1 deraadt 2598:
1.25 markus 2599: /* Get arguments from the packet. */
2600: port = packet_get_int();
2601: hostname = packet_get_string(NULL);
2602: host_port = packet_get_int();
2603:
1.27 markus 2604: /*
2605: * Check that an unprivileged user is not trying to forward a
2606: * privileged port.
2607: */
1.25 markus 2608: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 2609: packet_disconnect(
2610: "Requested forwarding of port %d but user is not root.",
2611: port);
2612: if (host_port == 0)
2613: packet_disconnect("Dynamic forwarding denied.");
2614:
1.73 markus 2615: /* Initiate forwarding */
1.253 markus 2616: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 2617: host_port, gateway_ports);
1.25 markus 2618:
2619: /* Free the argument string. */
2620: xfree(hostname);
1.253 markus 2621:
2622: return (success ? 0 : -1);
1.1 deraadt 2623: }
2624:
1.99 markus 2625: /*
2626: * Permits opening to any host/port if permitted_opens[] is empty. This is
2627: * usually called by the server, because the user could connect to any port
2628: * anyway, and the server has no way to know but to trust the client anyway.
2629: */
2630: void
1.142 itojun 2631: channel_permit_all_opens(void)
1.99 markus 2632: {
2633: if (num_permitted_opens == 0)
2634: all_opens_permitted = 1;
2635: }
2636:
1.101 markus 2637: void
1.99 markus 2638: channel_add_permitted_opens(char *host, int port)
2639: {
2640: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1.253 markus 2641: fatal("channel_add_permitted_opens: too many forwards");
1.99 markus 2642: debug("allow port forwarding to host %s port %d", host, port);
2643:
2644: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2645: permitted_opens[num_permitted_opens].port_to_connect = port;
2646: num_permitted_opens++;
2647:
2648: all_opens_permitted = 0;
2649: }
2650:
1.258 dtucker 2651: int
1.257 dtucker 2652: channel_add_adm_permitted_opens(char *host, int port)
2653: {
2654: if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2655: fatal("channel_add_adm_permitted_opens: too many forwards");
1.258 dtucker 2656: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 2657:
2658: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2659: = xstrdup(host);
2660: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 2661: return ++num_adm_permitted_opens;
1.257 dtucker 2662: }
2663:
2664: void
1.99 markus 2665: channel_clear_permitted_opens(void)
2666: {
2667: int i;
2668:
2669: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2670: if (permitted_opens[i].host_to_connect != NULL)
2671: xfree(permitted_opens[i].host_to_connect);
1.99 markus 2672: num_permitted_opens = 0;
1.257 dtucker 2673: }
2674:
2675: void
2676: channel_clear_adm_permitted_opens(void)
2677: {
2678: int i;
1.99 markus 2679:
1.257 dtucker 2680: for (i = 0; i < num_adm_permitted_opens; i++)
2681: if (permitted_adm_opens[i].host_to_connect != NULL)
2682: xfree(permitted_adm_opens[i].host_to_connect);
2683: num_adm_permitted_opens = 0;
1.99 markus 2684: }
2685:
2686: /* return socket to remote host, port */
1.127 itojun 2687: static int
1.99 markus 2688: connect_to(const char *host, u_short port)
1.41 markus 2689: {
2690: struct addrinfo hints, *ai, *aitop;
2691: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2692: int gaierr;
2693: int sock = -1;
2694:
2695: memset(&hints, 0, sizeof(hints));
2696: hints.ai_family = IPv4or6;
2697: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2698: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2699: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2700: error("connect_to %.100s: unknown host (%s)", host,
2701: gai_strerror(gaierr));
1.41 markus 2702: return -1;
2703: }
2704: for (ai = aitop; ai; ai = ai->ai_next) {
2705: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2706: continue;
2707: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2708: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2709: error("connect_to: getnameinfo failed");
1.41 markus 2710: continue;
2711: }
1.189 markus 2712: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.41 markus 2713: if (sock < 0) {
1.186 djm 2714: if (ai->ai_next == NULL)
2715: error("socket: %.100s", strerror(errno));
2716: else
2717: verbose("socket: %.100s", strerror(errno));
1.41 markus 2718: continue;
2719: }
1.205 djm 2720: if (set_nonblock(sock) == -1)
2721: fatal("%s: set_nonblock(%d)", __func__, sock);
1.75 markus 2722: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2723: errno != EINPROGRESS) {
1.99 markus 2724: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2725: strerror(errno));
2726: close(sock);
1.89 stevesk 2727: continue; /* fail -- try next */
1.41 markus 2728: }
2729: break; /* success */
2730:
2731: }
2732: freeaddrinfo(aitop);
2733: if (!ai) {
1.99 markus 2734: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2735: return -1;
2736: }
2737: /* success */
1.169 stevesk 2738: set_nodelay(sock);
1.41 markus 2739: return sock;
2740: }
1.99 markus 2741:
1.73 markus 2742: int
1.130 stevesk 2743: channel_connect_by_listen_address(u_short listen_port)
1.73 markus 2744: {
2745: int i;
1.99 markus 2746:
1.73 markus 2747: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2748: if (permitted_opens[i].host_to_connect != NULL &&
2749: permitted_opens[i].listen_port == listen_port)
1.99 markus 2750: return connect_to(
1.73 markus 2751: permitted_opens[i].host_to_connect,
2752: permitted_opens[i].port_to_connect);
1.74 markus 2753: error("WARNING: Server requests forwarding for unknown listen_port %d",
2754: listen_port);
1.73 markus 2755: return -1;
2756: }
2757:
1.99 markus 2758: /* Check if connecting to that port is permitted and connect. */
2759: int
2760: channel_connect_to(const char *host, u_short port)
2761: {
1.257 dtucker 2762: int i, permit, permit_adm = 1;
1.99 markus 2763:
2764: permit = all_opens_permitted;
2765: if (!permit) {
2766: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 2767: if (permitted_opens[i].host_to_connect != NULL &&
2768: permitted_opens[i].port_to_connect == port &&
1.99 markus 2769: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2770: permit = 1;
1.257 dtucker 2771: }
1.99 markus 2772:
1.257 dtucker 2773: if (num_adm_permitted_opens > 0) {
2774: permit_adm = 0;
2775: for (i = 0; i < num_adm_permitted_opens; i++)
2776: if (permitted_adm_opens[i].host_to_connect != NULL &&
2777: permitted_adm_opens[i].port_to_connect == port &&
2778: strcmp(permitted_adm_opens[i].host_to_connect, host)
2779: == 0)
2780: permit_adm = 1;
1.99 markus 2781: }
1.257 dtucker 2782:
2783: if (!permit || !permit_adm) {
1.188 itojun 2784: logit("Received request to connect to host %.100s port %d, "
1.99 markus 2785: "but the request was denied.", host, port);
2786: return -1;
2787: }
2788: return connect_to(host, port);
1.204 djm 2789: }
2790:
2791: void
2792: channel_send_window_changes(void)
2793: {
1.209 avsm 2794: u_int i;
1.204 djm 2795: struct winsize ws;
2796:
2797: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 2798: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 2799: channels[i]->type != SSH_CHANNEL_OPEN)
2800: continue;
2801: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2802: continue;
2803: channel_request_start(i, "window-change", 0);
1.238 deraadt 2804: packet_put_int((u_int)ws.ws_col);
2805: packet_put_int((u_int)ws.ws_row);
2806: packet_put_int((u_int)ws.ws_xpixel);
2807: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 2808: packet_send();
2809: }
1.99 markus 2810: }
2811:
1.121 markus 2812: /* -- X11 forwarding */
1.1 deraadt 2813:
1.27 markus 2814: /*
2815: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 2816: * Returns 0 and a suitable display number for the DISPLAY variable
2817: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 2818: */
1.141 stevesk 2819: int
1.163 stevesk 2820: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 2821: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 2822: {
1.149 markus 2823: Channel *nc = NULL;
1.31 markus 2824: int display_number, sock;
2825: u_short port;
1.35 markus 2826: struct addrinfo hints, *ai, *aitop;
2827: char strport[NI_MAXSERV];
2828: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 2829:
1.224 markus 2830: if (chanids == NULL)
2831: return -1;
2832:
1.33 markus 2833: for (display_number = x11_display_offset;
1.148 deraadt 2834: display_number < MAX_DISPLAYS;
2835: display_number++) {
1.25 markus 2836: port = 6000 + display_number;
1.35 markus 2837: memset(&hints, 0, sizeof(hints));
2838: hints.ai_family = IPv4or6;
1.163 stevesk 2839: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 2840: hints.ai_socktype = SOCK_STREAM;
2841: snprintf(strport, sizeof strport, "%d", port);
2842: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2843: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.141 stevesk 2844: return -1;
1.25 markus 2845: }
1.35 markus 2846: for (ai = aitop; ai; ai = ai->ai_next) {
2847: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2848: continue;
1.189 markus 2849: sock = socket(ai->ai_family, ai->ai_socktype,
2850: ai->ai_protocol);
1.35 markus 2851: if (sock < 0) {
2852: error("socket: %.100s", strerror(errno));
1.203 markus 2853: freeaddrinfo(aitop);
1.141 stevesk 2854: return -1;
1.35 markus 2855: }
1.226 djm 2856: channel_set_reuseaddr(sock);
1.35 markus 2857: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 2858: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 2859: close(sock);
1.183 itojun 2860:
2861: if (ai->ai_next)
2862: continue;
2863:
1.35 markus 2864: for (n = 0; n < num_socks; n++) {
2865: close(socks[n]);
2866: }
2867: num_socks = 0;
2868: break;
2869: }
2870: socks[num_socks++] = sock;
2871: if (num_socks == NUM_SOCKS)
2872: break;
1.25 markus 2873: }
1.83 stevesk 2874: freeaddrinfo(aitop);
1.35 markus 2875: if (num_socks > 0)
2876: break;
1.25 markus 2877: }
2878: if (display_number >= MAX_DISPLAYS) {
2879: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 2880: return -1;
1.25 markus 2881: }
2882: /* Start listening for connections on the socket. */
1.35 markus 2883: for (n = 0; n < num_socks; n++) {
2884: sock = socks[n];
1.199 markus 2885: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2886: error("listen: %.100s", strerror(errno));
2887: close(sock);
1.141 stevesk 2888: return -1;
1.35 markus 2889: }
1.25 markus 2890: }
1.35 markus 2891:
2892: /* Allocate a channel for each socket. */
1.242 djm 2893: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 2894: for (n = 0; n < num_socks; n++) {
2895: sock = socks[n];
1.149 markus 2896: nc = channel_new("x11 listener",
1.51 markus 2897: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2898: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 2899: 0, "X11 inet listener", 1);
1.167 markus 2900: nc->single_connection = single_connection;
1.224 markus 2901: (*chanids)[n] = nc->self;
1.35 markus 2902: }
1.224 markus 2903: (*chanids)[n] = -1;
1.1 deraadt 2904:
1.141 stevesk 2905: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 2906: *display_numberp = display_number;
2907: return (0);
1.1 deraadt 2908: }
2909:
1.127 itojun 2910: static int
1.77 markus 2911: connect_local_xsocket(u_int dnr)
1.1 deraadt 2912: {
1.25 markus 2913: int sock;
2914: struct sockaddr_un addr;
2915:
1.147 stevesk 2916: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2917: if (sock < 0)
2918: error("socket: %.100s", strerror(errno));
2919: memset(&addr, 0, sizeof(addr));
2920: addr.sun_family = AF_UNIX;
2921: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 2922: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 2923: return sock;
2924: close(sock);
1.25 markus 2925: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2926: return -1;
1.1 deraadt 2927: }
2928:
1.51 markus 2929: int
2930: x11_connect_display(void)
1.1 deraadt 2931: {
1.248 deraadt 2932: u_int display_number;
1.25 markus 2933: const char *display;
1.51 markus 2934: char buf[1024], *cp;
1.35 markus 2935: struct addrinfo hints, *ai, *aitop;
2936: char strport[NI_MAXSERV];
1.248 deraadt 2937: int gaierr, sock = 0;
1.25 markus 2938:
2939: /* Try to open a socket for the local X server. */
2940: display = getenv("DISPLAY");
2941: if (!display) {
2942: error("DISPLAY not set.");
1.51 markus 2943: return -1;
1.25 markus 2944: }
1.27 markus 2945: /*
2946: * Now we decode the value of the DISPLAY variable and make a
2947: * connection to the real X server.
2948: */
2949:
2950: /*
2951: * Check if it is a unix domain socket. Unix domain displays are in
2952: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2953: */
1.25 markus 2954: if (strncmp(display, "unix:", 5) == 0 ||
2955: display[0] == ':') {
2956: /* Connect to the unix domain socket. */
1.248 deraadt 2957: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 2958: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2959: display);
1.51 markus 2960: return -1;
1.25 markus 2961: }
2962: /* Create a socket. */
2963: sock = connect_local_xsocket(display_number);
2964: if (sock < 0)
1.51 markus 2965: return -1;
1.25 markus 2966:
2967: /* OK, we now have a connection to the display. */
1.51 markus 2968: return sock;
1.25 markus 2969: }
1.27 markus 2970: /*
2971: * Connect to an inet socket. The DISPLAY value is supposedly
2972: * hostname:d[.s], where hostname may also be numeric IP address.
2973: */
1.145 stevesk 2974: strlcpy(buf, display, sizeof(buf));
1.25 markus 2975: cp = strchr(buf, ':');
2976: if (!cp) {
2977: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2978: return -1;
1.25 markus 2979: }
2980: *cp = 0;
1.27 markus 2981: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 2982: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 2983: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 2984: display);
1.51 markus 2985: return -1;
1.25 markus 2986: }
1.35 markus 2987:
2988: /* Look up the host address */
2989: memset(&hints, 0, sizeof(hints));
2990: hints.ai_family = IPv4or6;
2991: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 2992: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 2993: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2994: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2995: return -1;
1.25 markus 2996: }
1.35 markus 2997: for (ai = aitop; ai; ai = ai->ai_next) {
2998: /* Create a socket. */
1.189 markus 2999: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3000: if (sock < 0) {
1.194 markus 3001: debug2("socket: %.100s", strerror(errno));
1.41 markus 3002: continue;
3003: }
3004: /* Connect it to the display. */
3005: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3006: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3007: 6000 + display_number, strerror(errno));
3008: close(sock);
3009: continue;
3010: }
3011: /* Success */
3012: break;
1.35 markus 3013: }
3014: freeaddrinfo(aitop);
3015: if (!ai) {
1.248 deraadt 3016: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3017: strerror(errno));
1.51 markus 3018: return -1;
1.25 markus 3019: }
1.162 stevesk 3020: set_nodelay(sock);
1.51 markus 3021: return sock;
3022: }
3023:
3024: /*
3025: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3026: * the remote channel number. We should do whatever we want, and respond
3027: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3028: */
3029:
1.259 stevesk 3030: /* ARGSUSED */
1.51 markus 3031: void
1.154 markus 3032: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3033: {
1.113 markus 3034: Channel *c = NULL;
3035: int remote_id, sock = 0;
1.51 markus 3036: char *remote_host;
1.25 markus 3037:
1.113 markus 3038: debug("Received X11 open request.");
1.51 markus 3039:
1.113 markus 3040: remote_id = packet_get_int();
1.121 markus 3041:
3042: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3043: remote_host = packet_get_string(NULL);
1.51 markus 3044: } else {
3045: remote_host = xstrdup("unknown (remote did not supply name)");
3046: }
1.152 markus 3047: packet_check_eom();
1.25 markus 3048:
1.51 markus 3049: /* Obtain a connection to the real X display. */
3050: sock = x11_connect_display();
1.113 markus 3051: if (sock != -1) {
3052: /* Allocate a channel for this connection. */
3053: c = channel_new("connected x11 socket",
3054: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3055: remote_host, 1);
1.167 markus 3056: c->remote_id = remote_id;
3057: c->force_drain = 1;
1.113 markus 3058: }
1.190 markus 3059: xfree(remote_host);
1.113 markus 3060: if (c == NULL) {
1.51 markus 3061: /* Send refusal to the remote host. */
3062: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3063: packet_put_int(remote_id);
1.51 markus 3064: } else {
3065: /* Send a confirmation to the remote host. */
3066: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3067: packet_put_int(remote_id);
3068: packet_put_int(c->self);
1.51 markus 3069: }
1.113 markus 3070: packet_send();
1.72 markus 3071: }
3072:
3073: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3074: /* ARGSUSED */
1.72 markus 3075: void
1.154 markus 3076: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3077: {
3078: int rchan = packet_get_int();
1.180 deraadt 3079:
1.143 deraadt 3080: switch (type) {
1.72 markus 3081: case SSH_SMSG_AGENT_OPEN:
3082: error("Warning: ssh server tried agent forwarding.");
3083: break;
3084: case SSH_SMSG_X11_OPEN:
3085: error("Warning: ssh server tried X11 forwarding.");
3086: break;
3087: default:
1.154 markus 3088: error("deny_input_open: type %d", type);
1.72 markus 3089: break;
3090: }
1.230 stevesk 3091: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3092: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3093: packet_put_int(rchan);
3094: packet_send();
1.1 deraadt 3095: }
3096:
1.27 markus 3097: /*
3098: * Requests forwarding of X11 connections, generates fake authentication
3099: * data, and enables authentication spoofing.
1.121 markus 3100: * This should be called in the client only.
1.27 markus 3101: */
1.49 markus 3102: void
1.215 djm 3103: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.51 markus 3104: const char *proto, const char *data)
1.1 deraadt 3105: {
1.77 markus 3106: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3107: u_int i, value;
1.25 markus 3108: char *new_data;
3109: int screen_number;
3110: const char *cp;
1.207 avsm 3111: u_int32_t rnd = 0;
1.25 markus 3112:
1.220 markus 3113: if (x11_saved_display == NULL)
3114: x11_saved_display = xstrdup(disp);
3115: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3116: error("x11_request_forwarding_with_spoofing: different "
3117: "$DISPLAY already forwarded");
3118: return;
3119: }
3120:
1.215 djm 3121: cp = disp;
3122: if (disp)
3123: cp = strchr(disp, ':');
1.25 markus 3124: if (cp)
3125: cp = strchr(cp, '.');
3126: if (cp)
1.245 deraadt 3127: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3128: else
3129: screen_number = 0;
3130:
1.219 djm 3131: if (x11_saved_proto == NULL) {
3132: /* Save protocol name. */
3133: x11_saved_proto = xstrdup(proto);
3134: /*
1.221 djm 3135: * Extract real authentication data and generate fake data
1.219 djm 3136: * of the same length.
3137: */
3138: x11_saved_data = xmalloc(data_len);
3139: x11_fake_data = xmalloc(data_len);
3140: for (i = 0; i < data_len; i++) {
3141: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3142: fatal("x11_request_forwarding: bad "
3143: "authentication data: %.100s", data);
3144: if (i % 4 == 0)
3145: rnd = arc4random();
3146: x11_saved_data[i] = value;
3147: x11_fake_data[i] = rnd & 0xff;
3148: rnd >>= 8;
3149: }
3150: x11_saved_data_len = data_len;
3151: x11_fake_data_len = data_len;
1.25 markus 3152: }
3153:
3154: /* Convert the fake data into hex. */
1.219 djm 3155: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3156:
3157: /* Send the request packet. */
1.51 markus 3158: if (compat20) {
3159: channel_request_start(client_session_id, "x11-req", 0);
3160: packet_put_char(0); /* XXX bool single connection */
3161: } else {
3162: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3163: }
3164: packet_put_cstring(proto);
3165: packet_put_cstring(new_data);
1.25 markus 3166: packet_put_int(screen_number);
3167: packet_send();
3168: packet_write_wait();
3169: xfree(new_data);
1.1 deraadt 3170: }
3171:
1.121 markus 3172:
3173: /* -- agent forwarding */
3174:
1.1 deraadt 3175: /* Sends a message to the server to request authentication fd forwarding. */
3176:
1.49 markus 3177: void
1.142 itojun 3178: auth_request_forwarding(void)
1.1 deraadt 3179: {
1.25 markus 3180: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3181: packet_send();
3182: packet_write_wait();
1.1 deraadt 3183: }
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