Annotation of src/usr.bin/ssh/channels.c, Revision 1.117
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.67 deraadt 17: * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
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"
1.117 ! stevesk 43: RCSID("$OpenBSD: channels.c,v 1.116 2001/05/16 22:09:20 markus Exp $");
1.82 markus 44:
45: #include <openssl/rsa.h>
46: #include <openssl/dsa.h>
1.1 deraadt 47:
48: #include "ssh.h"
1.82 markus 49: #include "ssh1.h"
50: #include "ssh2.h"
1.1 deraadt 51: #include "packet.h"
52: #include "xmalloc.h"
53: #include "buffer.h"
1.103 markus 54: #include "bufaux.h"
1.1 deraadt 55: #include "uidswap.h"
1.82 markus 56: #include "log.h"
57: #include "misc.h"
1.14 markus 58: #include "channels.h"
59: #include "nchan.h"
60: #include "compat.h"
1.82 markus 61: #include "canohost.h"
1.64 markus 62: #include "key.h"
63: #include "authfd.h"
1.44 markus 64:
1.1 deraadt 65: /* Maximum number of fake X11 displays to try. */
66: #define MAX_DISPLAYS 1000
67:
1.12 markus 68: /* Max len of agent socket */
69: #define MAX_SOCKET_NAME 100
70:
1.27 markus 71: /*
72: * Pointer to an array containing all allocated channels. The array is
73: * dynamically extended as needed.
74: */
1.113 markus 75: static Channel **channels = NULL;
1.1 deraadt 76:
1.27 markus 77: /*
78: * Size of the channel array. All slots of the array must always be
1.113 markus 79: * initialized (at least the type field); unused slots set to NULL
1.27 markus 80: */
1.1 deraadt 81: static int channels_alloc = 0;
82:
1.27 markus 83: /*
84: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 85: * updated in channel_new.
1.27 markus 86: */
1.84 markus 87: static int channel_max_fd = 0;
1.1 deraadt 88:
1.12 markus 89: /* Name and directory of socket for authentication agent forwarding. */
1.1 deraadt 90: static char *channel_forwarded_auth_socket_name = NULL;
1.25 markus 91: static char *channel_forwarded_auth_socket_dir = NULL;
1.1 deraadt 92:
93: /* Saved X11 authentication protocol name. */
94: char *x11_saved_proto = NULL;
95:
96: /* Saved X11 authentication data. This is the real data. */
97: char *x11_saved_data = NULL;
1.77 markus 98: u_int x11_saved_data_len = 0;
1.1 deraadt 99:
1.27 markus 100: /*
101: * Fake X11 authentication data. This is what the server will be sending us;
102: * we should replace any occurrences of this by the real data.
103: */
1.1 deraadt 104: char *x11_fake_data = NULL;
1.77 markus 105: u_int x11_fake_data_len;
1.1 deraadt 106:
1.27 markus 107: /*
108: * Data structure for storing which hosts are permitted for forward requests.
109: * The local sides of any remote forwards are stored in this array to prevent
110: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
111: * network (which might be behind a firewall).
112: */
1.25 markus 113: typedef struct {
1.41 markus 114: char *host_to_connect; /* Connect to 'host'. */
115: u_short port_to_connect; /* Connect to 'port'. */
116: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 117: } ForwardPermission;
118:
119: /* List of all permitted host/port pairs to connect. */
120: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
121: /* Number of permitted host/port pairs in the array. */
122: static int num_permitted_opens = 0;
1.27 markus 123: /*
124: * If this is true, all opens are permitted. This is the case on the server
125: * on which we have to trust the client anyway, and the user could do
126: * anything after logging in anyway.
127: */
1.1 deraadt 128: static int all_opens_permitted = 0;
129:
130: /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
131: static int have_hostname_in_open = 0;
1.82 markus 132:
133: /* AF_UNSPEC or AF_INET or AF_INET6 */
134: extern int IPv4or6;
1.1 deraadt 135:
1.103 markus 136: void port_open_helper(Channel *c, char *rtype);
137:
1.1 deraadt 138: /* Sets specific protocol options. */
139:
1.49 markus 140: void
1.25 markus 141: channel_set_options(int hostname_in_open)
1.1 deraadt 142: {
1.25 markus 143: have_hostname_in_open = hostname_in_open;
1.1 deraadt 144: }
145:
1.41 markus 146: /* lookup channel by id */
147:
148: Channel *
149: channel_lookup(int id)
150: {
151: Channel *c;
1.113 markus 152:
1.63 provos 153: if (id < 0 || id > channels_alloc) {
1.41 markus 154: log("channel_lookup: %d: bad id", id);
155: return NULL;
156: }
1.113 markus 157: c = channels[id];
158: if (c == NULL) {
1.41 markus 159: log("channel_lookup: %d: bad id: channel free", id);
160: return NULL;
161: }
162: return c;
1.55 markus 163: }
164:
1.27 markus 165: /*
1.55 markus 166: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 167: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 168: */
1.1 deraadt 169:
1.52 markus 170: void
1.71 markus 171: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
172: int extusage, int nonblock)
1.1 deraadt 173: {
1.25 markus 174: /* Update the maximum file descriptor value. */
1.84 markus 175: channel_max_fd = MAX(channel_max_fd, rfd);
176: channel_max_fd = MAX(channel_max_fd, wfd);
177: channel_max_fd = MAX(channel_max_fd, efd);
178:
1.27 markus 179: /* XXX set close-on-exec -markus */
1.55 markus 180:
1.52 markus 181: c->rfd = rfd;
182: c->wfd = wfd;
183: c->sock = (rfd == wfd) ? rfd : -1;
184: c->efd = efd;
185: c->extended_usage = extusage;
1.71 markus 186:
1.91 markus 187: /* XXX ugly hack: nonblock is only set by the server */
188: if (nonblock && isatty(c->rfd)) {
1.94 markus 189: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 190: c->isatty = 1;
191: if (!isatty(c->wfd)) {
1.94 markus 192: error("channel %d: wfd %d is not a tty?",
1.91 markus 193: c->self, c->wfd);
194: }
195: } else {
196: c->isatty = 0;
197: }
198:
1.71 markus 199: /* enable nonblocking mode */
200: if (nonblock) {
201: if (rfd != -1)
202: set_nonblock(rfd);
203: if (wfd != -1)
204: set_nonblock(wfd);
205: if (efd != -1)
206: set_nonblock(efd);
207: }
1.52 markus 208: }
209:
210: /*
211: * Allocate a new channel object and set its type and socket. This will cause
212: * remote_name to be freed.
213: */
214:
1.113 markus 215: Channel *
1.52 markus 216: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 217: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 218: {
219: int i, found;
220: Channel *c;
1.25 markus 221:
222: /* Do initial allocation if this is the first call. */
223: if (channels_alloc == 0) {
1.44 markus 224: chan_init();
1.25 markus 225: channels_alloc = 10;
1.113 markus 226: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 227: for (i = 0; i < channels_alloc; i++)
1.113 markus 228: channels[i] = NULL;
1.27 markus 229: /*
230: * Kludge: arrange a call to channel_stop_listening if we
231: * terminate with fatal().
232: */
1.25 markus 233: fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
234: }
235: /* Try to find a free slot where to put the new channel. */
236: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 237: if (channels[i] == NULL) {
1.25 markus 238: /* Found a free slot. */
239: found = i;
240: break;
241: }
242: if (found == -1) {
1.27 markus 243: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 244: found = channels_alloc;
245: channels_alloc += 10;
1.70 markus 246: debug2("channel: expanding %d", channels_alloc);
1.113 markus 247: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 248: for (i = found; i < channels_alloc; i++)
1.113 markus 249: channels[i] = NULL;
1.25 markus 250: }
1.113 markus 251: /* Initialize and return new channel. */
252: c = channels[found] = xmalloc(sizeof(Channel));
1.25 markus 253: buffer_init(&c->input);
254: buffer_init(&c->output);
1.41 markus 255: buffer_init(&c->extended);
1.25 markus 256: chan_init_iostates(c);
1.71 markus 257: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 258: c->self = found;
259: c->type = type;
1.41 markus 260: c->ctype = ctype;
1.51 markus 261: c->local_window = window;
262: c->local_window_max = window;
263: c->local_consumed = 0;
264: c->local_maxpacket = maxpack;
1.25 markus 265: c->remote_id = -1;
266: c->remote_name = remote_name;
1.41 markus 267: c->remote_window = 0;
268: c->remote_maxpacket = 0;
269: c->cb_fn = NULL;
270: c->cb_arg = NULL;
271: c->cb_event = 0;
272: c->dettach_user = NULL;
1.65 markus 273: c->input_filter = NULL;
1.25 markus 274: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 275: return c;
1.1 deraadt 276: }
1.52 markus 277:
278: /* Close all channel fd/socket. */
279:
280: void
281: channel_close_fds(Channel *c)
282: {
283: if (c->sock != -1) {
284: close(c->sock);
285: c->sock = -1;
286: }
287: if (c->rfd != -1) {
288: close(c->rfd);
289: c->rfd = -1;
290: }
291: if (c->wfd != -1) {
292: close(c->wfd);
293: c->wfd = -1;
294: }
295: if (c->efd != -1) {
296: close(c->efd);
297: c->efd = -1;
298: }
299: }
300:
301: /* Free the channel and close its fd/socket. */
1.1 deraadt 302:
1.49 markus 303: void
1.113 markus 304: channel_free(Channel *c)
1.1 deraadt 305: {
1.113 markus 306: char *s;
1.79 markus 307:
1.113 markus 308: s = channel_open_message();
309: debug("channel_free: channel %d: status: %s", c->self, s);
1.79 markus 310: xfree(s);
311:
1.44 markus 312: if (c->dettach_user != NULL) {
1.113 markus 313: debug("channel_free: channel %d: dettaching channel user", c->self);
1.44 markus 314: c->dettach_user(c->self, NULL);
315: }
1.54 markus 316: if (c->sock != -1)
317: shutdown(c->sock, SHUT_RDWR);
1.52 markus 318: channel_close_fds(c);
1.41 markus 319: buffer_free(&c->input);
320: buffer_free(&c->output);
321: buffer_free(&c->extended);
322: if (c->remote_name) {
323: xfree(c->remote_name);
324: c->remote_name = NULL;
1.25 markus 325: }
1.113 markus 326: channels[c->self] = NULL;
327: xfree(c);
1.1 deraadt 328: }
329:
1.27 markus 330: /*
1.41 markus 331: * 'channel_pre*' are called just before select() to add any bits relevant to
332: * channels in the select bitmasks.
333: */
334: /*
335: * 'channel_post*': perform any appropriate operations for channels which
336: * have events pending.
1.27 markus 337: */
1.41 markus 338: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
339: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
340: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
341:
342: void
343: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
344: {
345: FD_SET(c->sock, readset);
346: }
347:
348: void
1.75 markus 349: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
350: {
351: debug3("channel %d: waiting for connection", c->self);
352: FD_SET(c->sock, writeset);
353: }
354:
355: void
1.41 markus 356: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
357: {
358: if (buffer_len(&c->input) < packet_get_maxsize())
359: FD_SET(c->sock, readset);
360: if (buffer_len(&c->output) > 0)
361: FD_SET(c->sock, writeset);
362: }
1.1 deraadt 363:
1.41 markus 364: void
365: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
366: {
367: /* test whether sockets are 'alive' for read/write */
368: if (c->istate == CHAN_INPUT_OPEN)
369: if (buffer_len(&c->input) < packet_get_maxsize())
370: FD_SET(c->sock, readset);
371: if (c->ostate == CHAN_OUTPUT_OPEN ||
372: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
373: if (buffer_len(&c->output) > 0) {
374: FD_SET(c->sock, writeset);
375: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
376: chan_obuf_empty(c);
377: }
378: }
379: }
380:
381: void
1.44 markus 382: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
383: {
384: if (c->istate == CHAN_INPUT_OPEN &&
385: c->remote_window > 0 &&
386: buffer_len(&c->input) < c->remote_window)
387: FD_SET(c->rfd, readset);
388: if (c->ostate == CHAN_OUTPUT_OPEN ||
389: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
390: if (buffer_len(&c->output) > 0) {
391: FD_SET(c->wfd, writeset);
392: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
393: chan_obuf_empty(c);
394: }
395: }
396: /** XXX check close conditions, too */
397: if (c->efd != -1) {
398: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
399: buffer_len(&c->extended) > 0)
400: FD_SET(c->efd, writeset);
401: else if (c->extended_usage == CHAN_EXTENDED_READ &&
402: buffer_len(&c->extended) < c->remote_window)
403: FD_SET(c->efd, readset);
404: }
405: }
406:
407: void
1.41 markus 408: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
409: {
410: if (buffer_len(&c->input) == 0) {
411: packet_start(SSH_MSG_CHANNEL_CLOSE);
412: packet_put_int(c->remote_id);
413: packet_send();
414: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 415: debug("channel %d: closing after input drain.", c->self);
1.41 markus 416: }
417: }
418:
419: void
420: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
421: {
422: if (buffer_len(&c->output) == 0)
1.113 markus 423: chan_mark_dead(c);
1.49 markus 424: else
1.41 markus 425: FD_SET(c->sock, writeset);
426: }
427:
428: /*
429: * This is a special state for X11 authentication spoofing. An opened X11
430: * connection (when authentication spoofing is being done) remains in this
431: * state until the first packet has been completely read. The authentication
432: * data in that packet is then substituted by the real data if it matches the
433: * fake data, and the channel is put into normal mode.
1.51 markus 434: * XXX All this happens at the client side.
1.41 markus 435: */
436: int
437: x11_open_helper(Channel *c)
1.1 deraadt 438: {
1.77 markus 439: u_char *ucp;
440: u_int proto_len, data_len;
1.25 markus 441:
1.41 markus 442: /* Check if the fixed size part of the packet is in buffer. */
443: if (buffer_len(&c->output) < 12)
444: return 0;
445:
446: /* Parse the lengths of variable-length fields. */
1.77 markus 447: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 448: if (ucp[0] == 0x42) { /* Byte order MSB first. */
449: proto_len = 256 * ucp[6] + ucp[7];
450: data_len = 256 * ucp[8] + ucp[9];
451: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
452: proto_len = ucp[6] + 256 * ucp[7];
453: data_len = ucp[8] + 256 * ucp[9];
454: } else {
455: debug("Initial X11 packet contains bad byte order byte: 0x%x",
456: ucp[0]);
457: return -1;
458: }
459:
460: /* Check if the whole packet is in buffer. */
461: if (buffer_len(&c->output) <
462: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
463: return 0;
464:
465: /* Check if authentication protocol matches. */
466: if (proto_len != strlen(x11_saved_proto) ||
467: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
468: debug("X11 connection uses different authentication protocol.");
469: return -1;
470: }
471: /* Check if authentication data matches our fake data. */
472: if (data_len != x11_fake_data_len ||
473: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
474: x11_fake_data, x11_fake_data_len) != 0) {
475: debug("X11 auth data does not match fake data.");
476: return -1;
477: }
478: /* Check fake data length */
479: if (x11_fake_data_len != x11_saved_data_len) {
480: error("X11 fake_data_len %d != saved_data_len %d",
481: x11_fake_data_len, x11_saved_data_len);
482: return -1;
483: }
484: /*
485: * Received authentication protocol and data match
486: * our fake data. Substitute the fake data with real
487: * data.
488: */
489: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
490: x11_saved_data, x11_saved_data_len);
491: return 1;
492: }
493:
494: void
495: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
496: {
497: int ret = x11_open_helper(c);
498: if (ret == 1) {
499: /* Start normal processing for the channel. */
500: c->type = SSH_CHANNEL_OPEN;
1.47 markus 501: channel_pre_open_13(c, readset, writeset);
1.41 markus 502: } else if (ret == -1) {
503: /*
504: * We have received an X11 connection that has bad
505: * authentication information.
506: */
1.98 millert 507: log("X11 connection rejected because of wrong authentication.");
1.41 markus 508: buffer_clear(&c->input);
509: buffer_clear(&c->output);
510: close(c->sock);
511: c->sock = -1;
512: c->type = SSH_CHANNEL_CLOSED;
513: packet_start(SSH_MSG_CHANNEL_CLOSE);
514: packet_put_int(c->remote_id);
515: packet_send();
516: }
517: }
1.25 markus 518:
1.41 markus 519: void
1.51 markus 520: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 521: {
522: int ret = x11_open_helper(c);
523: if (ret == 1) {
524: c->type = SSH_CHANNEL_OPEN;
1.57 markus 525: if (compat20)
526: channel_pre_open_20(c, readset, writeset);
527: else
528: channel_pre_open_15(c, readset, writeset);
1.41 markus 529: } else if (ret == -1) {
530: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 531: chan_read_failed(c); /** force close? */
1.41 markus 532: chan_write_failed(c);
533: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
534: }
535: }
1.25 markus 536:
1.104 markus 537: /* try to decode a socks4 header */
538: int
539: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 540: {
541: u_char *p, *host;
1.109 markus 542: int len, have, i, found;
1.104 markus 543: char username[256];
1.103 markus 544: struct {
545: u_int8_t version;
546: u_int8_t command;
547: u_int16_t dest_port;
1.104 markus 548: struct in_addr dest_addr;
1.103 markus 549: } s4_req, s4_rsp;
550:
1.104 markus 551: debug2("channel %d: decode socks4", c->self);
1.109 markus 552:
553: have = buffer_len(&c->input);
554: len = sizeof(s4_req);
555: if (have < len)
556: return 0;
557: p = buffer_ptr(&c->input);
558: for (found = 0, i = len; i < have; i++) {
559: if (p[i] == '\0') {
560: found = 1;
561: break;
562: }
563: if (i > 1024) {
564: /* the peer is probably sending garbage */
565: debug("channel %d: decode socks4: too long",
566: c->self);
567: return -1;
568: }
569: }
570: if (!found)
571: return 0;
1.103 markus 572: buffer_get(&c->input, (char *)&s4_req.version, 1);
573: buffer_get(&c->input, (char *)&s4_req.command, 1);
574: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 575: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 576: have = buffer_len(&c->input);
1.103 markus 577: p = buffer_ptr(&c->input);
578: len = strlen(p);
1.106 markus 579: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 580: if (len > have)
1.104 markus 581: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 582: c->self, len, have);
583: strlcpy(username, p, sizeof(username));
584: buffer_consume(&c->input, len);
585: buffer_consume(&c->input, 1); /* trailing '\0' */
586:
1.104 markus 587: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 588: strlcpy(c->path, host, sizeof(c->path));
589: c->host_port = ntohs(s4_req.dest_port);
590:
1.106 markus 591: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
592: c->self, host, c->host_port, s4_req.command);
1.103 markus 593:
1.104 markus 594: if (s4_req.command != 1) {
595: debug("channel %d: cannot handle: socks4 cn %d",
596: c->self, s4_req.command);
597: return -1;
1.103 markus 598: }
1.104 markus 599: s4_rsp.version = 0; /* vn: 0 for reply */
600: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 601: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 602: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 603: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 604: return 1;
605: }
606:
607: /* dynamic port forwarding */
608: void
609: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
610: {
611: u_char *p;
612: int have, ret;
1.103 markus 613:
1.104 markus 614: have = buffer_len(&c->input);
615:
616: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 617: /* buffer_dump(&c->input); */
1.104 markus 618: /* check if the fixed size part of the packet is in buffer. */
619: if (have < 4) {
620: /* need more */
621: FD_SET(c->sock, readset);
622: return;
623: }
624: /* try to guess the protocol */
625: p = buffer_ptr(&c->input);
626: switch (p[0]) {
627: case 0x04:
628: ret = channel_decode_socks4(c, readset, writeset);
629: break;
630: default:
631: ret = -1;
632: break;
633: }
634: if (ret < 0) {
1.113 markus 635: chan_mark_dead(c);
1.104 markus 636: } else if (ret == 0) {
637: debug2("channel %d: pre_dynamic: need more", c->self);
638: /* need more */
639: FD_SET(c->sock, readset);
640: } else {
641: /* switch to the next state */
642: c->type = SSH_CHANNEL_OPENING;
643: port_open_helper(c, "direct-tcpip");
644: }
1.103 markus 645: }
646:
1.41 markus 647: /* This is our fake X11 server socket. */
648: void
649: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
650: {
1.113 markus 651: Channel *nc;
1.41 markus 652: struct sockaddr addr;
1.113 markus 653: int newsock;
1.41 markus 654: socklen_t addrlen;
1.85 markus 655: char buf[16384], *remote_ipaddr;
1.51 markus 656: int remote_port;
1.25 markus 657:
1.41 markus 658: if (FD_ISSET(c->sock, readset)) {
659: debug("X11 connection requested.");
660: addrlen = sizeof(addr);
661: newsock = accept(c->sock, &addr, &addrlen);
662: if (newsock < 0) {
663: error("accept: %.100s", strerror(errno));
664: return;
665: }
1.85 markus 666: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 667: remote_port = get_peer_port(newsock);
1.41 markus 668: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 669: remote_ipaddr, remote_port);
1.51 markus 670:
1.113 markus 671: nc = channel_new("accepted x11 socket",
1.51 markus 672: SSH_CHANNEL_OPENING, newsock, newsock, -1,
673: c->local_window_max, c->local_maxpacket,
1.71 markus 674: 0, xstrdup(buf), 1);
1.113 markus 675: if (nc == NULL) {
676: close(newsock);
677: xfree(remote_ipaddr);
678: return;
679: }
1.51 markus 680: if (compat20) {
681: packet_start(SSH2_MSG_CHANNEL_OPEN);
682: packet_put_cstring("x11");
1.113 markus 683: packet_put_int(nc->self);
1.51 markus 684: packet_put_int(c->local_window_max);
685: packet_put_int(c->local_maxpacket);
1.85 markus 686: /* originator ipaddr and port */
687: packet_put_cstring(remote_ipaddr);
1.57 markus 688: if (datafellows & SSH_BUG_X11FWD) {
689: debug("ssh2 x11 bug compat mode");
690: } else {
691: packet_put_int(remote_port);
692: }
1.51 markus 693: packet_send();
694: } else {
695: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 696: packet_put_int(nc->self);
1.51 markus 697: if (have_hostname_in_open)
698: packet_put_string(buf, strlen(buf));
699: packet_send();
700: }
1.85 markus 701: xfree(remote_ipaddr);
1.41 markus 702: }
703: }
1.25 markus 704:
1.103 markus 705: void
706: port_open_helper(Channel *c, char *rtype)
707: {
708: int direct;
709: char buf[1024];
710: char *remote_ipaddr = get_peer_ipaddr(c->sock);
711: u_short remote_port = get_peer_port(c->sock);
712:
713: direct = (strcmp(rtype, "direct-tcpip") == 0);
714:
715: snprintf(buf, sizeof buf,
716: "%s: listening port %d for %.100s port %d, "
717: "connect from %.200s port %d",
718: rtype, c->listening_port, c->path, c->host_port,
719: remote_ipaddr, remote_port);
720:
721: xfree(c->remote_name);
722: c->remote_name = xstrdup(buf);
723:
724: if (compat20) {
725: packet_start(SSH2_MSG_CHANNEL_OPEN);
726: packet_put_cstring(rtype);
727: packet_put_int(c->self);
728: packet_put_int(c->local_window_max);
729: packet_put_int(c->local_maxpacket);
730: if (direct) {
731: /* target host, port */
732: packet_put_cstring(c->path);
733: packet_put_int(c->host_port);
734: } else {
735: /* listen address, port */
736: packet_put_cstring(c->path);
737: packet_put_int(c->listening_port);
738: }
739: /* originator host and port */
740: packet_put_cstring(remote_ipaddr);
741: packet_put_int(remote_port);
742: packet_send();
743: } else {
744: packet_start(SSH_MSG_PORT_OPEN);
745: packet_put_int(c->self);
746: packet_put_cstring(c->path);
747: packet_put_int(c->host_port);
748: if (have_hostname_in_open)
749: packet_put_cstring(c->remote_name);
750: packet_send();
751: }
752: xfree(remote_ipaddr);
753: }
754:
1.41 markus 755: /*
756: * This socket is listening for connections to a forwarded TCP/IP port.
757: */
758: void
759: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
760: {
1.103 markus 761: Channel *nc;
1.41 markus 762: struct sockaddr addr;
1.113 markus 763: int newsock, nextstate;
1.41 markus 764: socklen_t addrlen;
1.103 markus 765: char *rtype;
1.73 markus 766:
1.41 markus 767: if (FD_ISSET(c->sock, readset)) {
768: debug("Connection to port %d forwarding "
769: "to %.100s port %d requested.",
770: c->listening_port, c->path, c->host_port);
1.103 markus 771:
772: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
773: "forwarded-tcpip" : "direct-tcpip";
1.115 markus 774: nextstate = (c->host_port == 0 &&
775: c->type != SSH_CHANNEL_RPORT_LISTENER) ?
776: SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
1.103 markus 777:
1.41 markus 778: addrlen = sizeof(addr);
779: newsock = accept(c->sock, &addr, &addrlen);
780: if (newsock < 0) {
781: error("accept: %.100s", strerror(errno));
782: return;
783: }
1.113 markus 784: nc = channel_new(rtype,
1.103 markus 785: nextstate, newsock, newsock, -1,
1.41 markus 786: c->local_window_max, c->local_maxpacket,
1.103 markus 787: 0, xstrdup(rtype), 1);
788: if (nc == NULL) {
1.113 markus 789: error("channel_post_port_listener: no new channel:");
790: close(newsock);
1.103 markus 791: return;
1.41 markus 792: }
1.103 markus 793: nc->listening_port = c->listening_port;
794: nc->host_port = c->host_port;
795: strlcpy(nc->path, c->path, sizeof(nc->path));
796:
797: if (nextstate != SSH_CHANNEL_DYNAMIC)
798: port_open_helper(nc, rtype);
1.41 markus 799: }
800: }
1.25 markus 801:
1.41 markus 802: /*
803: * This is the authentication agent socket listening for connections from
804: * clients.
805: */
806: void
807: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
808: {
1.113 markus 809: Channel *nc;
810: int newsock;
1.41 markus 811: struct sockaddr addr;
812: socklen_t addrlen;
1.25 markus 813:
1.41 markus 814: if (FD_ISSET(c->sock, readset)) {
815: addrlen = sizeof(addr);
816: newsock = accept(c->sock, &addr, &addrlen);
817: if (newsock < 0) {
818: error("accept from auth socket: %.100s", strerror(errno));
819: return;
820: }
1.113 markus 821: nc = channel_new("accepted auth socket",
1.73 markus 822: SSH_CHANNEL_OPENING, newsock, newsock, -1,
823: c->local_window_max, c->local_maxpacket,
824: 0, xstrdup("accepted auth socket"), 1);
1.113 markus 825: if (nc == NULL) {
826: error("channel_post_auth_listener: channel_new failed");
827: close(newsock);
828: }
1.73 markus 829: if (compat20) {
830: packet_start(SSH2_MSG_CHANNEL_OPEN);
831: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 832: packet_put_int(nc->self);
1.73 markus 833: packet_put_int(c->local_window_max);
834: packet_put_int(c->local_maxpacket);
835: } else {
836: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 837: packet_put_int(nc->self);
1.73 markus 838: }
1.41 markus 839: packet_send();
840: }
841: }
1.25 markus 842:
1.75 markus 843: void
844: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
845: {
1.114 markus 846: int err = 0;
847: int sz = sizeof(err);
848:
1.75 markus 849: if (FD_ISSET(c->sock, writeset)) {
1.114 markus 850: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
851: &sz) < 0) {
852: err = errno;
853: error("getsockopt SO_ERROR failed");
854: }
855: if (err == 0) {
856: debug("channel %d: connected", c->self);
857: c->type = SSH_CHANNEL_OPEN;
858: if (compat20) {
859: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
860: packet_put_int(c->remote_id);
861: packet_put_int(c->self);
862: packet_put_int(c->local_window);
863: packet_put_int(c->local_maxpacket);
864: } else {
865: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
866: packet_put_int(c->remote_id);
867: packet_put_int(c->self);
868: }
1.75 markus 869: } else {
1.114 markus 870: debug("channel %d: not connected: %s",
871: c->self, strerror(err));
872: if (compat20) {
873: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
874: packet_put_int(c->remote_id);
875: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
876: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
877: packet_put_cstring(strerror(err));
878: packet_put_cstring("");
879: }
1.75 markus 880: } else {
1.114 markus 881: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
882: packet_put_int(c->remote_id);
1.75 markus 883: }
1.114 markus 884: chan_mark_dead(c);
1.75 markus 885: }
1.114 markus 886: packet_send();
1.75 markus 887: }
888: }
889:
1.41 markus 890: int
891: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
892: {
893: char buf[16*1024];
894: int len;
1.25 markus 895:
1.116 markus 896: if (c->istate == CHAN_INPUT_OPEN &&
1.41 markus 897: FD_ISSET(c->rfd, readset)) {
898: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 899: if (len < 0 && (errno == EINTR || errno == EAGAIN))
900: return 1;
1.41 markus 901: if (len <= 0) {
1.51 markus 902: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 903: c->self, c->rfd, len);
1.104 markus 904: if (c->type != SSH_CHANNEL_OPEN) {
905: debug("channel %d: not open", c->self);
1.113 markus 906: chan_mark_dead(c);
1.103 markus 907: return -1;
1.104 markus 908: } else if (compat13) {
1.41 markus 909: buffer_consume(&c->output, buffer_len(&c->output));
910: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.105 markus 911: debug("channel %d: status set to input draining.", c->self);
1.25 markus 912: } else {
1.41 markus 913: chan_read_failed(c);
1.25 markus 914: }
1.41 markus 915: return -1;
916: }
1.65 markus 917: if(c->input_filter != NULL) {
1.66 markus 918: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 919: debug("channel %d: filter stops", c->self);
1.65 markus 920: chan_read_failed(c);
921: }
922: } else {
923: buffer_append(&c->input, buf, len);
924: }
1.41 markus 925: }
926: return 1;
927: }
928: int
929: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
930: {
1.95 markus 931: struct termios tio;
1.41 markus 932: int len;
1.25 markus 933:
1.41 markus 934: /* Send buffered output data to the socket. */
1.116 markus 935: if ((c->ostate == CHAN_OUTPUT_OPEN ||
936: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) &&
1.41 markus 937: FD_ISSET(c->wfd, writeset) &&
938: buffer_len(&c->output) > 0) {
939: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 940: buffer_len(&c->output));
941: if (len < 0 && (errno == EINTR || errno == EAGAIN))
942: return 1;
1.41 markus 943: if (len <= 0) {
1.104 markus 944: if (c->type != SSH_CHANNEL_OPEN) {
945: debug("channel %d: not open", c->self);
1.113 markus 946: chan_mark_dead(c);
1.104 markus 947: return -1;
948: } else if (compat13) {
1.41 markus 949: buffer_consume(&c->output, buffer_len(&c->output));
1.105 markus 950: debug("channel %d: status set to input draining.", c->self);
1.41 markus 951: c->type = SSH_CHANNEL_INPUT_DRAINING;
952: } else {
953: chan_write_failed(c);
954: }
955: return -1;
1.91 markus 956: }
957: if (compat20 && c->isatty) {
958: if (tcgetattr(c->wfd, &tio) == 0 &&
959: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
960: /*
961: * Simulate echo to reduce the impact of
1.96 markus 962: * traffic analysis. We need to match the
1.95 markus 963: * size of a SSH2_MSG_CHANNEL_DATA message
964: * (4 byte channel id + data)
1.91 markus 965: */
1.95 markus 966: packet_send_ignore(4 + len);
1.91 markus 967: packet_send();
968: }
1.25 markus 969: }
1.41 markus 970: buffer_consume(&c->output, len);
1.44 markus 971: if (compat20 && len > 0) {
972: c->local_consumed += len;
973: }
974: }
975: return 1;
976: }
977: int
978: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
979: {
980: char buf[16*1024];
981: int len;
982:
1.45 markus 983: /** XXX handle drain efd, too */
1.44 markus 984: if (c->efd != -1) {
985: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
986: FD_ISSET(c->efd, writeset) &&
987: buffer_len(&c->extended) > 0) {
988: len = write(c->efd, buffer_ptr(&c->extended),
989: buffer_len(&c->extended));
1.70 markus 990: debug2("channel %d: written %d to efd %d",
1.44 markus 991: c->self, len, c->efd);
1.93 markus 992: if (len < 0 && (errno == EINTR || errno == EAGAIN))
993: return 1;
994: if (len <= 0) {
995: debug2("channel %d: closing write-efd %d",
996: c->self, c->efd);
997: close(c->efd);
998: c->efd = -1;
999: } else {
1.44 markus 1000: buffer_consume(&c->extended, len);
1001: c->local_consumed += len;
1002: }
1003: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1004: FD_ISSET(c->efd, readset)) {
1005: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1006: debug2("channel %d: read %d from efd %d",
1.44 markus 1007: c->self, len, c->efd);
1.93 markus 1008: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1009: return 1;
1010: if (len <= 0) {
1011: debug2("channel %d: closing read-efd %d",
1.45 markus 1012: c->self, c->efd);
1013: close(c->efd);
1014: c->efd = -1;
1.93 markus 1015: } else {
1.44 markus 1016: buffer_append(&c->extended, buf, len);
1.93 markus 1017: }
1.44 markus 1018: }
1019: }
1020: return 1;
1021: }
1022: int
1.93 markus 1023: channel_check_window(Channel *c)
1.44 markus 1024: {
1.104 markus 1025: if (c->type == SSH_CHANNEL_OPEN &&
1026: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1027: c->local_window < c->local_window_max/2 &&
1028: c->local_consumed > 0) {
1029: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1030: packet_put_int(c->remote_id);
1031: packet_put_int(c->local_consumed);
1032: packet_send();
1.70 markus 1033: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1034: c->self, c->local_window,
1035: c->local_consumed);
1036: c->local_window += c->local_consumed;
1037: c->local_consumed = 0;
1.1 deraadt 1038: }
1.41 markus 1039: return 1;
1.1 deraadt 1040: }
1041:
1.41 markus 1042: void
1043: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1044: {
1045: channel_handle_rfd(c, readset, writeset);
1046: channel_handle_wfd(c, readset, writeset);
1047: }
1.1 deraadt 1048:
1.41 markus 1049: void
1.44 markus 1050: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1051: {
1052: channel_handle_rfd(c, readset, writeset);
1053: channel_handle_wfd(c, readset, writeset);
1054: channel_handle_efd(c, readset, writeset);
1.93 markus 1055:
1056: channel_check_window(c);
1.44 markus 1057: }
1058:
1059: void
1.41 markus 1060: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1061: {
1.41 markus 1062: int len;
1063: /* Send buffered output data to the socket. */
1064: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1065: len = write(c->sock, buffer_ptr(&c->output),
1066: buffer_len(&c->output));
1067: if (len <= 0)
1068: buffer_consume(&c->output, buffer_len(&c->output));
1069: else
1070: buffer_consume(&c->output, len);
1071: }
1072: }
1.25 markus 1073:
1.41 markus 1074: void
1.44 markus 1075: channel_handler_init_20(void)
1076: {
1077: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1078: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1079: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1080: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1081: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1082: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1083: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1084: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1085:
1086: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1087: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1088: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1089: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1090: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1091: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1092: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1093: }
1094:
1095: void
1.41 markus 1096: channel_handler_init_13(void)
1097: {
1098: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1099: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1100: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1101: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1102: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1103: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1104: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1105: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1106: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1107:
1.41 markus 1108: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1109: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1110: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1111: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1112: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1113: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1114: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1115: }
1.25 markus 1116:
1.41 markus 1117: void
1118: channel_handler_init_15(void)
1119: {
1120: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1121: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1122: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1123: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1124: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1125: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1126: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1127:
1.41 markus 1128: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1129: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1130: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1131: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1132: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1133: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1134: }
1.27 markus 1135:
1.41 markus 1136: void
1137: channel_handler_init(void)
1138: {
1139: int i;
1140: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1141: channel_pre[i] = NULL;
1142: channel_post[i] = NULL;
1143: }
1.44 markus 1144: if (compat20)
1145: channel_handler_init_20();
1146: else if (compat13)
1.41 markus 1147: channel_handler_init_13();
1148: else
1149: channel_handler_init_15();
1150: }
1.25 markus 1151:
1.49 markus 1152: void
1.41 markus 1153: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1154: {
1155: static int did_init = 0;
1156: int i;
1157: Channel *c;
1.25 markus 1158:
1.41 markus 1159: if (!did_init) {
1160: channel_handler_init();
1161: did_init = 1;
1162: }
1163: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1164: c = channels[i];
1165: if (c == NULL)
1.41 markus 1166: continue;
1167: if (ftab[c->type] == NULL)
1.25 markus 1168: continue;
1.41 markus 1169: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1170: if (chan_is_dead(c)) {
1171: /*
1172: * we have to remove the fd's from the select mask
1173: * before the channels are free'd and the fd's are
1174: * closed
1175: */
1176: if (c->wfd != -1)
1177: FD_CLR(c->wfd, writeset);
1178: if (c->rfd != -1)
1179: FD_CLR(c->rfd, readset);
1180: if (c->efd != -1) {
1181: if (c->extended_usage == CHAN_EXTENDED_READ)
1182: FD_CLR(c->efd, readset);
1183: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1184: FD_CLR(c->efd, writeset);
1185: }
1.113 markus 1186: channel_free(c);
1.93 markus 1187: }
1.1 deraadt 1188: }
1189: }
1190:
1.49 markus 1191: void
1.100 markus 1192: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1193: int rekeying)
1.41 markus 1194: {
1.84 markus 1195: int n;
1196: u_int sz;
1197:
1198: n = MAX(*maxfdp, channel_max_fd);
1199:
1200: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1201: if (*readsetp == NULL || n > *maxfdp) {
1202: if (*readsetp)
1203: xfree(*readsetp);
1204: if (*writesetp)
1205: xfree(*writesetp);
1206: *readsetp = xmalloc(sz);
1207: *writesetp = xmalloc(sz);
1208: *maxfdp = n;
1209: }
1210: memset(*readsetp, 0, sz);
1211: memset(*writesetp, 0, sz);
1212:
1.100 markus 1213: if (!rekeying)
1214: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1215: }
1216:
1.49 markus 1217: void
1.41 markus 1218: channel_after_select(fd_set * readset, fd_set * writeset)
1219: {
1220: channel_handler(channel_post, readset, writeset);
1221: }
1222:
1.84 markus 1223: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1224:
1.49 markus 1225: void
1.25 markus 1226: channel_output_poll()
1.1 deraadt 1227: {
1.25 markus 1228: int len, i;
1.41 markus 1229: Channel *c;
1.1 deraadt 1230:
1.25 markus 1231: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1232:
1233: c = channels[i];
1234: if (c == NULL)
1235: continue;
1.37 markus 1236:
1.27 markus 1237: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1238: if (compat13) {
1.41 markus 1239: if (c->type != SSH_CHANNEL_OPEN &&
1240: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1241: continue;
1242: } else {
1.41 markus 1243: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1244: continue;
1245: }
1.46 markus 1246: if (compat20 &&
1247: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1248: /* XXX is this true? */
1.97 markus 1249: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1250: continue;
1251: }
1.25 markus 1252:
1253: /* Get the amount of buffered data for this channel. */
1.93 markus 1254: if ((c->istate == CHAN_INPUT_OPEN ||
1255: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1256: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1257: /* Send some data for the other side over the secure connection. */
1.44 markus 1258: if (compat20) {
1259: if (len > c->remote_window)
1260: len = c->remote_window;
1261: if (len > c->remote_maxpacket)
1262: len = c->remote_maxpacket;
1.25 markus 1263: } else {
1.44 markus 1264: if (packet_is_interactive()) {
1265: if (len > 1024)
1266: len = 512;
1267: } else {
1268: /* Keep the packets at reasonable size. */
1269: if (len > packet_get_maxsize()/2)
1270: len = packet_get_maxsize()/2;
1271: }
1.25 markus 1272: }
1.41 markus 1273: if (len > 0) {
1.44 markus 1274: packet_start(compat20 ?
1275: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1276: packet_put_int(c->remote_id);
1277: packet_put_string(buffer_ptr(&c->input), len);
1278: packet_send();
1279: buffer_consume(&c->input, len);
1280: c->remote_window -= len;
1281: }
1282: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1283: if (compat13)
1284: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1285: /*
1286: * input-buffer is empty and read-socket shutdown:
1287: * tell peer, that we will not send more data: send IEOF
1288: */
1.41 markus 1289: chan_ibuf_empty(c);
1.25 markus 1290: }
1.44 markus 1291: /* Send extended data, i.e. stderr */
1292: if (compat20 &&
1293: c->remote_window > 0 &&
1294: (len = buffer_len(&c->extended)) > 0 &&
1295: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1296: debug2("channel %d: rwin %d elen %d euse %d",
1297: c->self, c->remote_window, buffer_len(&c->extended),
1298: c->extended_usage);
1.44 markus 1299: if (len > c->remote_window)
1300: len = c->remote_window;
1301: if (len > c->remote_maxpacket)
1302: len = c->remote_maxpacket;
1303: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1304: packet_put_int(c->remote_id);
1305: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1306: packet_put_string(buffer_ptr(&c->extended), len);
1307: packet_send();
1308: buffer_consume(&c->extended, len);
1309: c->remote_window -= len;
1.93 markus 1310: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1311: }
1.25 markus 1312: }
1.1 deraadt 1313: }
1314:
1.27 markus 1315: /*
1316: * This is called when a packet of type CHANNEL_DATA has just been received.
1317: * The message type has already been consumed, but channel number and data is
1318: * still there.
1319: */
1.1 deraadt 1320:
1.49 markus 1321: void
1.69 markus 1322: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1323: {
1.37 markus 1324: int id;
1.25 markus 1325: char *data;
1.77 markus 1326: u_int data_len;
1.41 markus 1327: Channel *c;
1.25 markus 1328:
1329: /* Get the channel number and verify it. */
1.37 markus 1330: id = packet_get_int();
1.41 markus 1331: c = channel_lookup(id);
1332: if (c == NULL)
1.37 markus 1333: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1334:
1335: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1336: if (c->type != SSH_CHANNEL_OPEN &&
1337: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1338: return;
1339:
1340: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1341: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1342: return;
1343:
1344: /* Get the data. */
1345: data = packet_get_string(&data_len);
1.48 markus 1346: packet_done();
1.41 markus 1347:
1.44 markus 1348: if (compat20){
1349: if (data_len > c->local_maxpacket) {
1350: log("channel %d: rcvd big packet %d, maxpack %d",
1351: c->self, data_len, c->local_maxpacket);
1352: }
1353: if (data_len > c->local_window) {
1354: log("channel %d: rcvd too much data %d, win %d",
1355: c->self, data_len, c->local_window);
1356: xfree(data);
1357: return;
1358: }
1359: c->local_window -= data_len;
1360: }else{
1361: packet_integrity_check(plen, 4 + 4 + data_len, type);
1362: }
1.41 markus 1363: buffer_append(&c->output, data, data_len);
1.25 markus 1364: xfree(data);
1.1 deraadt 1365: }
1.49 markus 1366: void
1.69 markus 1367: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1368: {
1369: int id;
1370: int tcode;
1371: char *data;
1.77 markus 1372: u_int data_len;
1.44 markus 1373: Channel *c;
1374:
1375: /* Get the channel number and verify it. */
1376: id = packet_get_int();
1377: c = channel_lookup(id);
1378:
1379: if (c == NULL)
1380: packet_disconnect("Received extended_data for bad channel %d.", id);
1381: if (c->type != SSH_CHANNEL_OPEN) {
1382: log("channel %d: ext data for non open", id);
1383: return;
1384: }
1385: tcode = packet_get_int();
1386: if (c->efd == -1 ||
1387: c->extended_usage != CHAN_EXTENDED_WRITE ||
1388: tcode != SSH2_EXTENDED_DATA_STDERR) {
1389: log("channel %d: bad ext data", c->self);
1390: return;
1391: }
1392: data = packet_get_string(&data_len);
1.48 markus 1393: packet_done();
1.44 markus 1394: if (data_len > c->local_window) {
1395: log("channel %d: rcvd too much extended_data %d, win %d",
1396: c->self, data_len, c->local_window);
1397: xfree(data);
1398: return;
1399: }
1.70 markus 1400: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1401: c->local_window -= data_len;
1402: buffer_append(&c->extended, data, data_len);
1403: xfree(data);
1404: }
1405:
1.1 deraadt 1406:
1.27 markus 1407: /*
1408: * Returns true if no channel has too much buffered data, and false if one or
1409: * more channel is overfull.
1410: */
1.1 deraadt 1411:
1.49 markus 1412: int
1.25 markus 1413: channel_not_very_much_buffered_data()
1.1 deraadt 1414: {
1.77 markus 1415: u_int i;
1.41 markus 1416: Channel *c;
1.25 markus 1417:
1418: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1419: c = channels[i];
1420: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1421: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1422: debug("channel %d: big input buffer %d",
1423: c->self, buffer_len(&c->input));
1.25 markus 1424: return 0;
1.41 markus 1425: }
1426: if (buffer_len(&c->output) > packet_get_maxsize()) {
1427: debug("channel %d: big output buffer %d",
1428: c->self, buffer_len(&c->output));
1.25 markus 1429: return 0;
1.41 markus 1430: }
1.25 markus 1431: }
1.1 deraadt 1432: }
1.25 markus 1433: return 1;
1.1 deraadt 1434: }
1435:
1.49 markus 1436: void
1.69 markus 1437: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1438: {
1439: int id;
1440: Channel *c;
1441:
1442: packet_integrity_check(plen, 4, type);
1443:
1444: id = packet_get_int();
1445: c = channel_lookup(id);
1446: if (c == NULL)
1447: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1448: chan_rcvd_ieof(c);
1449: }
1.1 deraadt 1450:
1.49 markus 1451: void
1.69 markus 1452: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1453: {
1.41 markus 1454: int id;
1455: Channel *c;
1.1 deraadt 1456:
1.41 markus 1457: packet_integrity_check(plen, 4, type);
1458:
1459: id = packet_get_int();
1460: c = channel_lookup(id);
1461: if (c == NULL)
1462: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1463:
1464: /*
1465: * Send a confirmation that we have closed the channel and no more
1466: * data is coming for it.
1467: */
1.25 markus 1468: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1469: packet_put_int(c->remote_id);
1.25 markus 1470: packet_send();
1471:
1.27 markus 1472: /*
1473: * If the channel is in closed state, we have sent a close request,
1474: * and the other side will eventually respond with a confirmation.
1475: * Thus, we cannot free the channel here, because then there would be
1476: * no-one to receive the confirmation. The channel gets freed when
1477: * the confirmation arrives.
1478: */
1.41 markus 1479: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1480: /*
1481: * Not a closed channel - mark it as draining, which will
1482: * cause it to be freed later.
1483: */
1.41 markus 1484: buffer_consume(&c->input, buffer_len(&c->input));
1485: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1486: }
1.1 deraadt 1487: }
1488:
1.41 markus 1489: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1490: void
1.69 markus 1491: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1492: {
1493: int id = packet_get_int();
1494: Channel *c = channel_lookup(id);
1495: packet_integrity_check(plen, 4, type);
1496: if (c == NULL)
1497: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1498: chan_rcvd_oclose(c);
1499: }
1.1 deraadt 1500:
1.49 markus 1501: void
1.69 markus 1502: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1503: {
1.41 markus 1504: int id = packet_get_int();
1505: Channel *c = channel_lookup(id);
1.1 deraadt 1506:
1.48 markus 1507: packet_done();
1.41 markus 1508: if (c == NULL)
1509: packet_disconnect("Received close confirmation for "
1510: "out-of-range channel %d.", id);
1511: if (c->type != SSH_CHANNEL_CLOSED)
1512: packet_disconnect("Received close confirmation for "
1513: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1514: channel_free(c);
1.1 deraadt 1515: }
1516:
1.49 markus 1517: void
1.69 markus 1518: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1519: {
1.41 markus 1520: int id, remote_id;
1521: Channel *c;
1.1 deraadt 1522:
1.44 markus 1523: if (!compat20)
1524: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1525:
1.41 markus 1526: id = packet_get_int();
1527: c = channel_lookup(id);
1.25 markus 1528:
1.41 markus 1529: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1530: packet_disconnect("Received open confirmation for "
1531: "non-opening channel %d.", id);
1532: remote_id = packet_get_int();
1.27 markus 1533: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1534: c->remote_id = remote_id;
1535: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1536:
1537: if (compat20) {
1538: c->remote_window = packet_get_int();
1539: c->remote_maxpacket = packet_get_int();
1.48 markus 1540: packet_done();
1.44 markus 1541: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1542: debug2("callback start");
1.44 markus 1543: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1544: debug2("callback done");
1.44 markus 1545: }
1546: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1547: c->remote_window, c->remote_maxpacket);
1548: }
1.1 deraadt 1549: }
1550:
1.114 markus 1551: char *
1552: reason2txt(int reason)
1553: {
1554: switch(reason) {
1555: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
1556: return "administratively prohibited";
1557: case SSH2_OPEN_CONNECT_FAILED:
1558: return "connect failed";
1559: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
1560: return "unknown channel type";
1561: case SSH2_OPEN_RESOURCE_SHORTAGE:
1562: return "resource shortage";
1563: }
1.117 ! stevesk 1564: return "unknown reason";
1.114 markus 1565: }
1566:
1.49 markus 1567: void
1.69 markus 1568: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1569: {
1.86 markus 1570: int id, reason;
1571: char *msg = NULL, *lang = NULL;
1.41 markus 1572: Channel *c;
1573:
1.44 markus 1574: if (!compat20)
1575: packet_integrity_check(plen, 4, type);
1.41 markus 1576:
1577: id = packet_get_int();
1578: c = channel_lookup(id);
1.25 markus 1579:
1.41 markus 1580: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1581: packet_disconnect("Received open failure for "
1582: "non-opening channel %d.", id);
1.44 markus 1583: if (compat20) {
1.86 markus 1584: reason = packet_get_int();
1.110 markus 1585: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1586: msg = packet_get_string(NULL);
1587: lang = packet_get_string(NULL);
1588: }
1.48 markus 1589: packet_done();
1.114 markus 1590: log("channel %d: open failed: %s%s%s", id,
1591: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1592: if (msg != NULL)
1593: xfree(msg);
1594: if (lang != NULL)
1595: xfree(lang);
1.44 markus 1596: }
1.25 markus 1597: /* Free the channel. This will also close the socket. */
1.113 markus 1598: channel_free(c);
1.1 deraadt 1599: }
1600:
1.44 markus 1601: void
1.69 markus 1602: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1603: {
1604: int id;
1605: Channel *c;
1606:
1607: id = packet_get_int();
1608: c = channel_lookup(id);
1609:
1610: if (c == NULL ||
1611: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1612: packet_disconnect("Received request for "
1613: "non-open channel %d.", id);
1614: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1615: debug2("callback start");
1.44 markus 1616: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1617: debug2("callback done");
1.44 markus 1618: } else {
1619: char *service = packet_get_string(NULL);
1.94 markus 1620: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1621: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1622: xfree(service);
1623: }
1624: }
1625:
1.49 markus 1626: void
1.69 markus 1627: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1628: {
1629: Channel *c;
1630: int id, adjust;
1631:
1632: if (!compat20)
1633: return;
1634:
1635: /* Get the channel number and verify it. */
1636: id = packet_get_int();
1637: c = channel_lookup(id);
1638:
1639: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1640: log("Received window adjust for "
1641: "non-open channel %d.", id);
1642: return;
1643: }
1644: adjust = packet_get_int();
1.48 markus 1645: packet_done();
1.70 markus 1646: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1647: c->remote_window += adjust;
1648: }
1649:
1.27 markus 1650: /*
1651: * Stops listening for channels, and removes any unix domain sockets that we
1652: * might have.
1653: */
1.1 deraadt 1654:
1.49 markus 1655: void
1.25 markus 1656: channel_stop_listening()
1.1 deraadt 1657: {
1.25 markus 1658: int i;
1.113 markus 1659: Channel *c;
1660:
1.25 markus 1661: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1662: c = channels[i];
1663: if (c != NULL) {
1664: switch (c->type) {
1665: case SSH_CHANNEL_AUTH_SOCKET:
1666: close(c->sock);
1667: unlink(c->path);
1668: channel_free(c);
1669: break;
1670: case SSH_CHANNEL_PORT_LISTENER:
1671: case SSH_CHANNEL_RPORT_LISTENER:
1672: case SSH_CHANNEL_X11_LISTENER:
1673: close(c->sock);
1674: channel_free(c);
1675: break;
1676: default:
1677: break;
1678: }
1.25 markus 1679: }
1.1 deraadt 1680: }
1681: }
1682:
1.27 markus 1683: /*
1.52 markus 1684: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1685: * descriptors after a fork.
1686: */
1.1 deraadt 1687:
1.49 markus 1688: void
1.25 markus 1689: channel_close_all()
1.1 deraadt 1690: {
1.25 markus 1691: int i;
1.113 markus 1692:
1.52 markus 1693: for (i = 0; i < channels_alloc; i++)
1.113 markus 1694: if (channels[i] != NULL)
1695: channel_close_fds(channels[i]);
1.1 deraadt 1696: }
1697:
1698: /* Returns true if any channel is still open. */
1699:
1.49 markus 1700: int
1.25 markus 1701: channel_still_open()
1.1 deraadt 1702: {
1.113 markus 1703: int i;
1704: Channel *c;
1705:
1706: for (i = 0; i < channels_alloc; i++) {
1707: c = channels[i];
1708: if (c == NULL)
1709: continue;
1710: switch (c->type) {
1.25 markus 1711: case SSH_CHANNEL_X11_LISTENER:
1712: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1713: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1714: case SSH_CHANNEL_CLOSED:
1715: case SSH_CHANNEL_AUTH_SOCKET:
1.103 markus 1716: case SSH_CHANNEL_DYNAMIC:
1.114 markus 1717: case SSH_CHANNEL_CONNECTING:
1.25 markus 1718: continue;
1.44 markus 1719: case SSH_CHANNEL_LARVAL:
1720: if (!compat20)
1721: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1722: continue;
1.25 markus 1723: case SSH_CHANNEL_OPENING:
1724: case SSH_CHANNEL_OPEN:
1725: case SSH_CHANNEL_X11_OPEN:
1726: return 1;
1727: case SSH_CHANNEL_INPUT_DRAINING:
1728: case SSH_CHANNEL_OUTPUT_DRAINING:
1729: if (!compat13)
1730: fatal("cannot happen: OUT_DRAIN");
1731: return 1;
1732: default:
1.113 markus 1733: fatal("channel_still_open: bad channel type %d", c->type);
1.25 markus 1734: /* NOTREACHED */
1735: }
1.113 markus 1736: }
1.25 markus 1737: return 0;
1.1 deraadt 1738: }
1.107 beck 1739:
1740: /* Returns the id of an open channel suitable for keepaliving */
1741:
1742: int
1743: channel_find_open()
1744: {
1.113 markus 1745: int i;
1746: Channel *c;
1747:
1748: for (i = 0; i < channels_alloc; i++) {
1749: c = channels[i];
1750: if (c == NULL)
1751: continue;
1752: switch (c->type) {
1.107 beck 1753: case SSH_CHANNEL_CLOSED:
1754: case SSH_CHANNEL_DYNAMIC:
1755: case SSH_CHANNEL_X11_LISTENER:
1756: case SSH_CHANNEL_PORT_LISTENER:
1757: case SSH_CHANNEL_RPORT_LISTENER:
1758: case SSH_CHANNEL_OPENING:
1.114 markus 1759: case SSH_CHANNEL_CONNECTING:
1.108 markus 1760: continue;
1761: case SSH_CHANNEL_LARVAL:
1762: case SSH_CHANNEL_AUTH_SOCKET:
1.107 beck 1763: case SSH_CHANNEL_OPEN:
1764: case SSH_CHANNEL_X11_OPEN:
1765: return i;
1766: case SSH_CHANNEL_INPUT_DRAINING:
1767: case SSH_CHANNEL_OUTPUT_DRAINING:
1768: if (!compat13)
1769: fatal("cannot happen: OUT_DRAIN");
1770: return i;
1771: default:
1.113 markus 1772: fatal("channel_find_open: bad channel type %d", c->type);
1.107 beck 1773: /* NOTREACHED */
1774: }
1.113 markus 1775: }
1.107 beck 1776: return -1;
1777: }
1778:
1.1 deraadt 1779:
1.27 markus 1780: /*
1781: * Returns a message describing the currently open forwarded connections,
1782: * suitable for sending to the client. The message contains crlf pairs for
1783: * newlines.
1784: */
1.1 deraadt 1785:
1.25 markus 1786: char *
1787: channel_open_message()
1.1 deraadt 1788: {
1.25 markus 1789: Buffer buffer;
1.113 markus 1790: Channel *c;
1791: char buf[1024], *cp;
1.25 markus 1792: int i;
1793:
1794: buffer_init(&buffer);
1795: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1796: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1797: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1798: c = channels[i];
1799: if (c == NULL)
1800: continue;
1.25 markus 1801: switch (c->type) {
1802: case SSH_CHANNEL_X11_LISTENER:
1803: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1804: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1805: case SSH_CHANNEL_CLOSED:
1806: case SSH_CHANNEL_AUTH_SOCKET:
1807: continue;
1.44 markus 1808: case SSH_CHANNEL_LARVAL:
1.25 markus 1809: case SSH_CHANNEL_OPENING:
1.75 markus 1810: case SSH_CHANNEL_CONNECTING:
1.103 markus 1811: case SSH_CHANNEL_DYNAMIC:
1.25 markus 1812: case SSH_CHANNEL_OPEN:
1813: case SSH_CHANNEL_X11_OPEN:
1814: case SSH_CHANNEL_INPUT_DRAINING:
1815: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1816: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1817: c->self, c->remote_name,
1818: c->type, c->remote_id,
1819: c->istate, buffer_len(&c->input),
1.41 markus 1820: c->ostate, buffer_len(&c->output),
1821: c->rfd, c->wfd);
1.25 markus 1822: buffer_append(&buffer, buf, strlen(buf));
1823: continue;
1824: default:
1.41 markus 1825: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1826: /* NOTREACHED */
1827: }
1828: }
1829: buffer_append(&buffer, "\0", 1);
1830: cp = xstrdup(buffer_ptr(&buffer));
1831: buffer_free(&buffer);
1832: return cp;
1.1 deraadt 1833: }
1834:
1.27 markus 1835: /*
1836: * Initiate forwarding of connections to local port "port" through the secure
1837: * channel to host:port from remote side.
1838: */
1.87 markus 1839: int
1.73 markus 1840: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1841: u_short port_to_connect, int gateway_ports)
1842: {
1.87 markus 1843: return channel_request_forwarding(
1.73 markus 1844: NULL, listen_port,
1845: host_to_connect, port_to_connect,
1846: gateway_ports, /*remote_fwd*/ 0);
1847: }
1.1 deraadt 1848:
1.73 markus 1849: /*
1850: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1851: * (SSH_CHANNEL_RPORT_LISTENER).
1852: */
1.87 markus 1853: int
1.73 markus 1854: channel_request_forwarding(
1855: const char *listen_address, u_short listen_port,
1856: const char *host_to_connect, u_short port_to_connect,
1857: int gateway_ports, int remote_fwd)
1.25 markus 1858: {
1.113 markus 1859: Channel *c;
1860: int success, sock, on = 1, ctype;
1.35 markus 1861: struct addrinfo hints, *ai, *aitop;
1862: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1863: const char *host;
1.28 markus 1864: struct linger linger;
1.25 markus 1865:
1.87 markus 1866: success = 0;
1867:
1.73 markus 1868: if (remote_fwd) {
1869: host = listen_address;
1.89 stevesk 1870: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1871: } else {
1872: host = host_to_connect;
1873: ctype =SSH_CHANNEL_PORT_LISTENER;
1874: }
1875:
1.113 markus 1876: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 1877: error("Forward host name too long.");
1878: return success;
1879: }
1.25 markus 1880:
1.73 markus 1881: /* XXX listen_address is currently ignored */
1.28 markus 1882: /*
1.35 markus 1883: * getaddrinfo returns a loopback address if the hostname is
1884: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1885: */
1.35 markus 1886: memset(&hints, 0, sizeof(hints));
1887: hints.ai_family = IPv4or6;
1888: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1889: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1890: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1891: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1892: packet_disconnect("getaddrinfo: fatal error");
1893:
1894: for (ai = aitop; ai; ai = ai->ai_next) {
1895: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1896: continue;
1897: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1898: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1899: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1900: continue;
1901: }
1902: /* Create a port to listen for the host. */
1903: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1904: if (sock < 0) {
1905: /* this is no error since kernel may not support ipv6 */
1906: verbose("socket: %.100s", strerror(errno));
1907: continue;
1908: }
1909: /*
1910: * Set socket options. We would like the socket to disappear
1911: * as soon as it has been closed for whatever reason.
1912: */
1913: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1914: linger.l_onoff = 1;
1915: linger.l_linger = 5;
1916: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1917: debug("Local forwarding listening on %s port %s.", ntop, strport);
1918:
1919: /* Bind the socket to the address. */
1920: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1921: /* address can be in use ipv6 address is already bound */
1922: verbose("bind: %.100s", strerror(errno));
1923: close(sock);
1924: continue;
1925: }
1926: /* Start listening for connections on the socket. */
1927: if (listen(sock, 5) < 0) {
1928: error("listen: %.100s", strerror(errno));
1929: close(sock);
1930: continue;
1931: }
1932: /* Allocate a channel number for the socket. */
1.113 markus 1933: c = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1934: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1935: 0, xstrdup("port listener"), 1);
1.113 markus 1936: if (c == NULL) {
1937: error("channel_request_forwarding: channel_new failed");
1938: close(sock);
1939: continue;
1940: }
1941: strlcpy(c->path, host, sizeof(c->path));
1942: c->host_port = port_to_connect;
1943: c->listening_port = listen_port;
1.35 markus 1944: success = 1;
1945: }
1946: if (success == 0)
1.87 markus 1947: error("channel_request_forwarding: cannot listen to port: %d",
1948: listen_port);
1.35 markus 1949: freeaddrinfo(aitop);
1.87 markus 1950: return success;
1.25 markus 1951: }
1.1 deraadt 1952:
1.27 markus 1953: /*
1954: * Initiate forwarding of connections to port "port" on remote host through
1955: * the secure channel to host:port from local side.
1956: */
1.1 deraadt 1957:
1.49 markus 1958: void
1.73 markus 1959: channel_request_remote_forwarding(u_short listen_port,
1960: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1961: {
1.73 markus 1962: int payload_len, type, success = 0;
1963:
1.25 markus 1964: /* Record locally that connection to this host/port is permitted. */
1965: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1966: fatal("channel_request_remote_forwarding: too many forwards");
1967:
1968: /* Send the forward request to the remote side. */
1.44 markus 1969: if (compat20) {
1970: const char *address_to_bind = "0.0.0.0";
1971: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1972: packet_put_cstring("tcpip-forward");
1973: packet_put_char(0); /* boolean: want reply */
1974: packet_put_cstring(address_to_bind);
1975: packet_put_int(listen_port);
1.73 markus 1976: packet_send();
1977: packet_write_wait();
1978: /* Assume that server accepts the request */
1979: success = 1;
1.44 markus 1980: } else {
1981: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1982: packet_put_int(listen_port);
1983: packet_put_cstring(host_to_connect);
1.44 markus 1984: packet_put_int(port_to_connect);
1985: packet_send();
1986: packet_write_wait();
1.73 markus 1987:
1988: /* Wait for response from the remote side. */
1989: type = packet_read(&payload_len);
1990: switch (type) {
1991: case SSH_SMSG_SUCCESS:
1992: success = 1;
1993: break;
1994: case SSH_SMSG_FAILURE:
1995: log("Warning: Server denied remote port forwarding.");
1996: break;
1997: default:
1998: /* Unknown packet */
1999: packet_disconnect("Protocol error for port forward request:"
2000: "received packet type %d.", type);
2001: }
2002: }
2003: if (success) {
2004: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2005: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2006: permitted_opens[num_permitted_opens].listen_port = listen_port;
2007: num_permitted_opens++;
1.44 markus 2008: }
1.1 deraadt 2009: }
2010:
1.27 markus 2011: /*
2012: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2013: * listening for the port, and sends back a success reply (or disconnect
2014: * message if there was an error). This never returns if there was an error.
2015: */
1.1 deraadt 2016:
1.49 markus 2017: void
1.56 markus 2018: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2019: {
1.31 markus 2020: u_short port, host_port;
1.25 markus 2021: char *hostname;
1.1 deraadt 2022:
1.25 markus 2023: /* Get arguments from the packet. */
2024: port = packet_get_int();
2025: hostname = packet_get_string(NULL);
2026: host_port = packet_get_int();
2027:
1.27 markus 2028: /*
2029: * Check that an unprivileged user is not trying to forward a
2030: * privileged port.
2031: */
1.25 markus 2032: if (port < IPPORT_RESERVED && !is_root)
2033: packet_disconnect("Requested forwarding of port %d but user is not root.",
2034: port);
1.73 markus 2035: /* Initiate forwarding */
1.56 markus 2036: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2037:
2038: /* Free the argument string. */
2039: xfree(hostname);
1.1 deraadt 2040: }
2041:
1.99 markus 2042: /*
2043: * Permits opening to any host/port if permitted_opens[] is empty. This is
2044: * usually called by the server, because the user could connect to any port
2045: * anyway, and the server has no way to know but to trust the client anyway.
2046: */
2047: void
2048: channel_permit_all_opens()
2049: {
2050: if (num_permitted_opens == 0)
2051: all_opens_permitted = 1;
2052: }
2053:
1.101 markus 2054: void
1.99 markus 2055: channel_add_permitted_opens(char *host, int port)
2056: {
2057: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2058: fatal("channel_request_remote_forwarding: too many forwards");
2059: debug("allow port forwarding to host %s port %d", host, port);
2060:
2061: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2062: permitted_opens[num_permitted_opens].port_to_connect = port;
2063: num_permitted_opens++;
2064:
2065: all_opens_permitted = 0;
2066: }
2067:
1.101 markus 2068: void
1.99 markus 2069: channel_clear_permitted_opens(void)
2070: {
2071: int i;
2072:
2073: for (i = 0; i < num_permitted_opens; i++)
2074: xfree(permitted_opens[i].host_to_connect);
2075: num_permitted_opens = 0;
2076:
2077: }
2078:
2079:
2080: /* return socket to remote host, port */
1.41 markus 2081: int
1.99 markus 2082: connect_to(const char *host, u_short port)
1.41 markus 2083: {
2084: struct addrinfo hints, *ai, *aitop;
2085: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2086: int gaierr;
2087: int sock = -1;
2088:
2089: memset(&hints, 0, sizeof(hints));
2090: hints.ai_family = IPv4or6;
2091: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2092: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2093: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2094: error("connect_to %.100s: unknown host (%s)", host,
2095: gai_strerror(gaierr));
1.41 markus 2096: return -1;
2097: }
2098: for (ai = aitop; ai; ai = ai->ai_next) {
2099: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2100: continue;
2101: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2102: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2103: error("connect_to: getnameinfo failed");
1.41 markus 2104: continue;
2105: }
2106: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2107: if (sock < 0) {
2108: error("socket: %.100s", strerror(errno));
2109: continue;
2110: }
1.80 markus 2111: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2112: fatal("connect_to: F_SETFL: %s", strerror(errno));
2113: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2114: errno != EINPROGRESS) {
1.99 markus 2115: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2116: strerror(errno));
2117: close(sock);
1.89 stevesk 2118: continue; /* fail -- try next */
1.41 markus 2119: }
2120: break; /* success */
2121:
2122: }
2123: freeaddrinfo(aitop);
2124: if (!ai) {
1.99 markus 2125: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2126: return -1;
2127: }
2128: /* success */
2129: return sock;
2130: }
1.99 markus 2131:
1.73 markus 2132: int
2133: channel_connect_by_listen_adress(u_short listen_port)
2134: {
2135: int i;
1.99 markus 2136:
1.73 markus 2137: for (i = 0; i < num_permitted_opens; i++)
2138: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2139: return connect_to(
1.73 markus 2140: permitted_opens[i].host_to_connect,
2141: permitted_opens[i].port_to_connect);
1.74 markus 2142: error("WARNING: Server requests forwarding for unknown listen_port %d",
2143: listen_port);
1.73 markus 2144: return -1;
2145: }
2146:
1.99 markus 2147: /* Check if connecting to that port is permitted and connect. */
2148: int
2149: channel_connect_to(const char *host, u_short port)
2150: {
2151: int i, permit;
2152:
2153: permit = all_opens_permitted;
2154: if (!permit) {
2155: for (i = 0; i < num_permitted_opens; i++)
2156: if (permitted_opens[i].port_to_connect == port &&
2157: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2158: permit = 1;
2159:
2160: }
2161: if (!permit) {
2162: log("Received request to connect to host %.100s port %d, "
2163: "but the request was denied.", host, port);
2164: return -1;
2165: }
2166: return connect_to(host, port);
2167: }
2168:
1.27 markus 2169: /*
2170: * This is called after receiving PORT_OPEN message. This attempts to
2171: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2172: * or CHANNEL_OPEN_FAILURE.
2173: */
1.1 deraadt 2174:
1.49 markus 2175: void
1.69 markus 2176: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2177: {
1.113 markus 2178: Channel *c = NULL;
1.31 markus 2179: u_short host_port;
1.25 markus 2180: char *host, *originator_string;
1.113 markus 2181: int remote_id, sock = -1;
1.25 markus 2182:
1.113 markus 2183: remote_id = packet_get_int();
1.99 markus 2184: host = packet_get_string(NULL);
1.25 markus 2185: host_port = packet_get_int();
2186:
1.29 markus 2187: if (have_hostname_in_open) {
1.99 markus 2188: originator_string = packet_get_string(NULL);
1.29 markus 2189: } else {
1.25 markus 2190: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 2191: }
1.99 markus 2192: packet_done();
2193: sock = channel_connect_to(host, host_port);
2194: if (sock != -1) {
1.113 markus 2195: c = channel_new("connected socket",
2196: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2197: originator_string, 1);
2198: if (c == NULL) {
2199: error("channel_input_port_open: channel_new failed");
2200: close(sock);
2201: } else {
2202: c->remote_id = remote_id;
2203: }
2204: }
2205: if (c == NULL) {
2206: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2207: packet_put_int(remote_id);
1.114 markus 2208: packet_send();
1.25 markus 2209: }
2210: xfree(host);
1.1 deraadt 2211: }
2212:
1.27 markus 2213: /*
2214: * Creates an internet domain socket for listening for X11 connections.
2215: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2216: * occurs.
2217: */
1.1 deraadt 2218:
1.35 markus 2219: #define NUM_SOCKS 10
2220:
1.25 markus 2221: char *
1.33 markus 2222: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2223: {
1.31 markus 2224: int display_number, sock;
2225: u_short port;
1.35 markus 2226: struct addrinfo hints, *ai, *aitop;
2227: char strport[NI_MAXSERV];
2228: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2229: char display[512];
1.25 markus 2230: char hostname[MAXHOSTNAMELEN];
2231:
1.33 markus 2232: for (display_number = x11_display_offset;
1.25 markus 2233: display_number < MAX_DISPLAYS;
2234: display_number++) {
2235: port = 6000 + display_number;
1.35 markus 2236: memset(&hints, 0, sizeof(hints));
2237: hints.ai_family = IPv4or6;
1.36 markus 2238: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2239: hints.ai_socktype = SOCK_STREAM;
2240: snprintf(strport, sizeof strport, "%d", port);
2241: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2242: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2243: return NULL;
2244: }
1.35 markus 2245: for (ai = aitop; ai; ai = ai->ai_next) {
2246: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2247: continue;
2248: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2249: if (sock < 0) {
2250: error("socket: %.100s", strerror(errno));
2251: return NULL;
2252: }
2253: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2254: debug("bind port %d: %.100s", port, strerror(errno));
2255: shutdown(sock, SHUT_RDWR);
2256: close(sock);
2257: for (n = 0; n < num_socks; n++) {
2258: shutdown(socks[n], SHUT_RDWR);
2259: close(socks[n]);
2260: }
2261: num_socks = 0;
2262: break;
2263: }
2264: socks[num_socks++] = sock;
2265: if (num_socks == NUM_SOCKS)
2266: break;
1.25 markus 2267: }
1.83 stevesk 2268: freeaddrinfo(aitop);
1.35 markus 2269: if (num_socks > 0)
2270: break;
1.25 markus 2271: }
2272: if (display_number >= MAX_DISPLAYS) {
2273: error("Failed to allocate internet-domain X11 display socket.");
2274: return NULL;
2275: }
2276: /* Start listening for connections on the socket. */
1.35 markus 2277: for (n = 0; n < num_socks; n++) {
2278: sock = socks[n];
2279: if (listen(sock, 5) < 0) {
2280: error("listen: %.100s", strerror(errno));
2281: shutdown(sock, SHUT_RDWR);
2282: close(sock);
2283: return NULL;
2284: }
1.25 markus 2285: }
1.35 markus 2286:
1.25 markus 2287: /* Set up a suitable value for the DISPLAY variable. */
2288: if (gethostname(hostname, sizeof(hostname)) < 0)
2289: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2290: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2291: display_number, screen_number);
2292:
1.35 markus 2293: /* Allocate a channel for each socket. */
2294: for (n = 0; n < num_socks; n++) {
2295: sock = socks[n];
1.51 markus 2296: (void) channel_new("x11 listener",
2297: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2298: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2299: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2300: }
1.1 deraadt 2301:
1.25 markus 2302: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2303: return xstrdup(display);
1.1 deraadt 2304: }
2305:
2306: #ifndef X_UNIX_PATH
2307: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2308: #endif
2309:
2310: static
2311: int
1.77 markus 2312: connect_local_xsocket(u_int dnr)
1.1 deraadt 2313: {
1.25 markus 2314: static const char *const x_sockets[] = {
2315: X_UNIX_PATH "%u",
2316: "/var/X/.X11-unix/X" "%u",
2317: "/usr/spool/sockets/X11/" "%u",
2318: NULL
2319: };
2320: int sock;
2321: struct sockaddr_un addr;
2322: const char *const * path;
2323:
2324: for (path = x_sockets; *path; ++path) {
2325: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2326: if (sock < 0)
2327: error("socket: %.100s", strerror(errno));
2328: memset(&addr, 0, sizeof(addr));
2329: addr.sun_family = AF_UNIX;
2330: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2331: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2332: return sock;
2333: close(sock);
2334: }
2335: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2336: return -1;
1.1 deraadt 2337: }
2338:
1.51 markus 2339: int
2340: x11_connect_display(void)
1.1 deraadt 2341: {
1.51 markus 2342: int display_number, sock = 0;
1.25 markus 2343: const char *display;
1.51 markus 2344: char buf[1024], *cp;
1.35 markus 2345: struct addrinfo hints, *ai, *aitop;
2346: char strport[NI_MAXSERV];
2347: int gaierr;
1.25 markus 2348:
2349: /* Try to open a socket for the local X server. */
2350: display = getenv("DISPLAY");
2351: if (!display) {
2352: error("DISPLAY not set.");
1.51 markus 2353: return -1;
1.25 markus 2354: }
1.27 markus 2355: /*
2356: * Now we decode the value of the DISPLAY variable and make a
2357: * connection to the real X server.
2358: */
2359:
2360: /*
2361: * Check if it is a unix domain socket. Unix domain displays are in
2362: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2363: */
1.25 markus 2364: if (strncmp(display, "unix:", 5) == 0 ||
2365: display[0] == ':') {
2366: /* Connect to the unix domain socket. */
2367: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2368: error("Could not parse display number from DISPLAY: %.100s",
2369: display);
1.51 markus 2370: return -1;
1.25 markus 2371: }
2372: /* Create a socket. */
2373: sock = connect_local_xsocket(display_number);
2374: if (sock < 0)
1.51 markus 2375: return -1;
1.25 markus 2376:
2377: /* OK, we now have a connection to the display. */
1.51 markus 2378: return sock;
1.25 markus 2379: }
1.27 markus 2380: /*
2381: * Connect to an inet socket. The DISPLAY value is supposedly
2382: * hostname:d[.s], where hostname may also be numeric IP address.
2383: */
1.25 markus 2384: strncpy(buf, display, sizeof(buf));
2385: buf[sizeof(buf) - 1] = 0;
2386: cp = strchr(buf, ':');
2387: if (!cp) {
2388: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2389: return -1;
1.25 markus 2390: }
2391: *cp = 0;
1.27 markus 2392: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2393: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2394: error("Could not parse display number from DISPLAY: %.100s",
2395: display);
1.51 markus 2396: return -1;
1.25 markus 2397: }
1.35 markus 2398:
2399: /* Look up the host address */
2400: memset(&hints, 0, sizeof(hints));
2401: hints.ai_family = IPv4or6;
2402: hints.ai_socktype = SOCK_STREAM;
2403: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2404: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2405: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2406: return -1;
1.25 markus 2407: }
1.35 markus 2408: for (ai = aitop; ai; ai = ai->ai_next) {
2409: /* Create a socket. */
2410: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2411: if (sock < 0) {
2412: debug("socket: %.100s", strerror(errno));
1.41 markus 2413: continue;
2414: }
2415: /* Connect it to the display. */
2416: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2417: debug("connect %.100s port %d: %.100s", buf,
2418: 6000 + display_number, strerror(errno));
2419: close(sock);
2420: continue;
2421: }
2422: /* Success */
2423: break;
1.35 markus 2424: }
2425: freeaddrinfo(aitop);
2426: if (!ai) {
1.49 markus 2427: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2428: strerror(errno));
1.51 markus 2429: return -1;
1.25 markus 2430: }
1.51 markus 2431: return sock;
2432: }
2433:
2434: /*
2435: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2436: * the remote channel number. We should do whatever we want, and respond
2437: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2438: */
2439:
2440: void
1.69 markus 2441: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2442: {
1.113 markus 2443: Channel *c = NULL;
2444: int remote_id, sock = 0;
1.51 markus 2445: char *remote_host;
1.25 markus 2446:
1.113 markus 2447: debug("Received X11 open request.");
1.51 markus 2448:
1.113 markus 2449: remote_id = packet_get_int();
1.51 markus 2450: if (have_hostname_in_open) {
1.113 markus 2451: remote_host = packet_get_string(NULL);
1.51 markus 2452: } else {
2453: remote_host = xstrdup("unknown (remote did not supply name)");
2454: }
1.113 markus 2455: packet_done();
1.25 markus 2456:
1.51 markus 2457: /* Obtain a connection to the real X display. */
2458: sock = x11_connect_display();
1.113 markus 2459: if (sock != -1) {
2460: /* Allocate a channel for this connection. */
2461: c = channel_new("connected x11 socket",
2462: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2463: remote_host, 1);
2464: if (c == NULL) {
2465: error("x11_input_open: channel_new failed");
2466: close(sock);
2467: } else {
2468: c->remote_id = remote_id;
2469: }
2470: }
2471: if (c == NULL) {
1.51 markus 2472: /* Send refusal to the remote host. */
2473: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2474: packet_put_int(remote_id);
1.51 markus 2475: } else {
2476: /* Send a confirmation to the remote host. */
2477: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2478: packet_put_int(remote_id);
2479: packet_put_int(c->self);
1.51 markus 2480: }
1.113 markus 2481: packet_send();
1.72 markus 2482: }
2483:
2484: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2485: void
2486: deny_input_open(int type, int plen, void *ctxt)
2487: {
2488: int rchan = packet_get_int();
2489: switch(type){
2490: case SSH_SMSG_AGENT_OPEN:
2491: error("Warning: ssh server tried agent forwarding.");
2492: break;
2493: case SSH_SMSG_X11_OPEN:
2494: error("Warning: ssh server tried X11 forwarding.");
2495: break;
2496: default:
2497: error("deny_input_open: type %d plen %d", type, plen);
2498: break;
2499: }
2500: error("Warning: this is probably a break in attempt by a malicious server.");
2501: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2502: packet_put_int(rchan);
2503: packet_send();
1.1 deraadt 2504: }
2505:
1.27 markus 2506: /*
2507: * Requests forwarding of X11 connections, generates fake authentication
2508: * data, and enables authentication spoofing.
2509: */
1.1 deraadt 2510:
1.49 markus 2511: void
1.51 markus 2512: x11_request_forwarding_with_spoofing(int client_session_id,
2513: const char *proto, const char *data)
1.1 deraadt 2514: {
1.77 markus 2515: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2516: u_int i, value, len;
1.25 markus 2517: char *new_data;
2518: int screen_number;
2519: const char *cp;
2520: u_int32_t rand = 0;
2521:
2522: cp = getenv("DISPLAY");
2523: if (cp)
2524: cp = strchr(cp, ':');
2525: if (cp)
2526: cp = strchr(cp, '.');
2527: if (cp)
2528: screen_number = atoi(cp + 1);
2529: else
2530: screen_number = 0;
2531:
2532: /* Save protocol name. */
2533: x11_saved_proto = xstrdup(proto);
2534:
1.27 markus 2535: /*
2536: * Extract real authentication data and generate fake data of the
2537: * same length.
2538: */
1.25 markus 2539: x11_saved_data = xmalloc(data_len);
2540: x11_fake_data = xmalloc(data_len);
2541: for (i = 0; i < data_len; i++) {
2542: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2543: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2544: if (i % 4 == 0)
2545: rand = arc4random();
2546: x11_saved_data[i] = value;
2547: x11_fake_data[i] = rand & 0xff;
2548: rand >>= 8;
2549: }
2550: x11_saved_data_len = data_len;
2551: x11_fake_data_len = data_len;
2552:
2553: /* Convert the fake data into hex. */
1.90 markus 2554: len = 2 * data_len + 1;
2555: new_data = xmalloc(len);
1.25 markus 2556: for (i = 0; i < data_len; i++)
1.90 markus 2557: snprintf(new_data + 2 * i, len - 2 * i,
2558: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2559:
2560: /* Send the request packet. */
1.51 markus 2561: if (compat20) {
2562: channel_request_start(client_session_id, "x11-req", 0);
2563: packet_put_char(0); /* XXX bool single connection */
2564: } else {
2565: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2566: }
2567: packet_put_cstring(proto);
2568: packet_put_cstring(new_data);
1.25 markus 2569: packet_put_int(screen_number);
2570: packet_send();
2571: packet_write_wait();
2572: xfree(new_data);
1.1 deraadt 2573: }
2574:
2575: /* Sends a message to the server to request authentication fd forwarding. */
2576:
1.49 markus 2577: void
1.25 markus 2578: auth_request_forwarding()
1.1 deraadt 2579: {
1.25 markus 2580: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2581: packet_send();
2582: packet_write_wait();
1.1 deraadt 2583: }
2584:
1.27 markus 2585: /*
2586: * Returns the name of the forwarded authentication socket. Returns NULL if
2587: * there is no forwarded authentication socket. The returned value points to
2588: * a static buffer.
2589: */
1.1 deraadt 2590:
1.25 markus 2591: char *
2592: auth_get_socket_name()
1.1 deraadt 2593: {
1.25 markus 2594: return channel_forwarded_auth_socket_name;
1.1 deraadt 2595: }
2596:
1.12 markus 2597: /* removes the agent forwarding socket */
2598:
1.49 markus 2599: void
1.25 markus 2600: cleanup_socket(void)
2601: {
1.78 markus 2602: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2603: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2604: }
2605:
1.27 markus 2606: /*
1.59 markus 2607: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2608: * This starts forwarding authentication requests.
2609: */
1.1 deraadt 2610:
1.59 markus 2611: int
1.25 markus 2612: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2613: {
1.113 markus 2614: Channel *nc;
2615: int sock;
1.25 markus 2616: struct sockaddr_un sunaddr;
2617:
2618: if (auth_get_socket_name() != NULL)
2619: fatal("Protocol error: authentication forwarding requested twice.");
2620:
2621: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2622: temporarily_use_uid(pw);
1.25 markus 2623:
2624: /* Allocate a buffer for the socket name, and format the name. */
2625: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2626: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2627: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2628:
2629: /* Create private directory for socket */
1.59 markus 2630: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2631: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2632: strerror(errno));
2633: restore_uid();
2634: xfree(channel_forwarded_auth_socket_name);
2635: xfree(channel_forwarded_auth_socket_dir);
2636: channel_forwarded_auth_socket_name = NULL;
2637: channel_forwarded_auth_socket_dir = NULL;
2638: return 0;
2639: }
1.25 markus 2640: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2641: channel_forwarded_auth_socket_dir, (int) getpid());
2642:
2643: if (atexit(cleanup_socket) < 0) {
2644: int saved = errno;
2645: cleanup_socket();
2646: packet_disconnect("socket: %.100s", strerror(saved));
2647: }
2648: /* Create the socket. */
2649: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2650: if (sock < 0)
2651: packet_disconnect("socket: %.100s", strerror(errno));
2652:
2653: /* Bind it to the name. */
2654: memset(&sunaddr, 0, sizeof(sunaddr));
2655: sunaddr.sun_family = AF_UNIX;
2656: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2657: sizeof(sunaddr.sun_path));
2658:
2659: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2660: packet_disconnect("bind: %.100s", strerror(errno));
2661:
2662: /* Restore the privileged uid. */
2663: restore_uid();
2664:
2665: /* Start listening on the socket. */
2666: if (listen(sock, 5) < 0)
2667: packet_disconnect("listen: %.100s", strerror(errno));
2668:
2669: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2670: nc = channel_new("auth socket",
1.73 markus 2671: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2672: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2673: 0, xstrdup("auth socket"), 1);
1.113 markus 2674: if (nc == NULL) {
2675: error("auth_input_request_forwarding: channel_new failed");
2676: close(sock);
2677: return 0;
2678: }
2679: strlcpy(nc->path, channel_forwarded_auth_socket_name, sizeof(nc->path));
1.59 markus 2680: return 1;
1.1 deraadt 2681: }
2682:
2683: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2684:
1.49 markus 2685: void
1.69 markus 2686: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2687: {
1.113 markus 2688: Channel *c = NULL;
2689: int remote_id, sock;
1.25 markus 2690: char *dummyname;
1.41 markus 2691:
2692: packet_integrity_check(plen, 4, type);
1.25 markus 2693:
2694: /* Read the remote channel number from the message. */
1.113 markus 2695: remote_id = packet_get_int();
1.25 markus 2696:
1.27 markus 2697: /*
2698: * Get a connection to the local authentication agent (this may again
2699: * get forwarded).
2700: */
1.25 markus 2701: sock = ssh_get_authentication_socket();
2702:
1.27 markus 2703: /*
2704: * If we could not connect the agent, send an error message back to
2705: * the server. This should never happen unless the agent dies,
2706: * because authentication forwarding is only enabled if we have an
2707: * agent.
2708: */
1.113 markus 2709: if (sock >= 0) {
2710: dummyname = xstrdup("authentication agent connection");
2711: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1);
2712: if (c == NULL) {
2713: error("auth_input_open_request: channel_new failed");
2714: close(sock);
2715: } else {
2716: c->remote_id = remote_id;
2717: }
2718: }
2719: if (c == NULL) {
1.25 markus 2720: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2721: packet_put_int(remote_id);
2722: } else {
2723: /* Send a confirmation to the remote host. */
2724: debug("Forwarding authentication connection.");
2725: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2726: packet_put_int(remote_id);
2727: packet_put_int(c->self);
1.25 markus 2728: }
1.44 markus 2729: packet_send();
2730: }
2731:
2732: void
1.51 markus 2733: channel_start_open(int id)
1.44 markus 2734: {
2735: Channel *c = channel_lookup(id);
2736: if (c == NULL) {
2737: log("channel_open: %d: bad id", id);
2738: return;
2739: }
1.51 markus 2740: debug("send channel open %d", id);
1.44 markus 2741: packet_start(SSH2_MSG_CHANNEL_OPEN);
2742: packet_put_cstring(c->ctype);
2743: packet_put_int(c->self);
2744: packet_put_int(c->local_window);
2745: packet_put_int(c->local_maxpacket);
1.51 markus 2746: }
2747: void
2748: channel_open(int id)
2749: {
2750: /* XXX REMOVE ME */
2751: channel_start_open(id);
1.44 markus 2752: packet_send();
2753: }
2754: void
2755: channel_request(int id, char *service, int wantconfirm)
2756: {
2757: channel_request_start(id, service, wantconfirm);
2758: packet_send();
2759: debug("channel request %d: %s", id, service) ;
2760: }
2761: void
2762: channel_request_start(int id, char *service, int wantconfirm)
2763: {
2764: Channel *c = channel_lookup(id);
2765: if (c == NULL) {
2766: log("channel_request: %d: bad id", id);
2767: return;
2768: }
2769: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2770: packet_put_int(c->remote_id);
2771: packet_put_cstring(service);
2772: packet_put_char(wantconfirm);
2773: }
2774: void
2775: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2776: {
2777: Channel *c = channel_lookup(id);
2778: if (c == NULL) {
2779: log("channel_register_callback: %d: bad id", id);
2780: return;
2781: }
2782: c->cb_event = mtype;
2783: c->cb_fn = fn;
2784: c->cb_arg = arg;
2785: }
2786: void
2787: channel_register_cleanup(int id, channel_callback_fn *fn)
2788: {
2789: Channel *c = channel_lookup(id);
2790: if (c == NULL) {
2791: log("channel_register_cleanup: %d: bad id", id);
2792: return;
2793: }
2794: c->dettach_user = fn;
2795: }
2796: void
2797: channel_cancel_cleanup(int id)
2798: {
2799: Channel *c = channel_lookup(id);
2800: if (c == NULL) {
2801: log("channel_cancel_cleanup: %d: bad id", id);
2802: return;
2803: }
2804: c->dettach_user = NULL;
1.65 markus 2805: }
1.89 stevesk 2806: void
1.65 markus 2807: channel_register_filter(int id, channel_filter_fn *fn)
2808: {
2809: Channel *c = channel_lookup(id);
2810: if (c == NULL) {
2811: log("channel_register_filter: %d: bad id", id);
2812: return;
2813: }
2814: c->input_filter = fn;
1.44 markus 2815: }
2816:
2817: void
1.71 markus 2818: channel_set_fds(int id, int rfd, int wfd, int efd,
2819: int extusage, int nonblock)
1.44 markus 2820: {
2821: Channel *c = channel_lookup(id);
2822: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2823: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2824: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2825: c->type = SSH_CHANNEL_OPEN;
2826: /* XXX window size? */
1.68 markus 2827: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2828: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2829: packet_put_int(c->remote_id);
2830: packet_put_int(c->local_window);
1.25 markus 2831: packet_send();
1.1 deraadt 2832: }
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