Annotation of src/usr.bin/ssh/channels.c, Revision 1.114
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"
1.114 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.113 2001/05/04 23:47:33 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";
774: nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :
775: SSH_CHANNEL_OPENING;
776:
1.41 markus 777: addrlen = sizeof(addr);
778: newsock = accept(c->sock, &addr, &addrlen);
779: if (newsock < 0) {
780: error("accept: %.100s", strerror(errno));
781: return;
782: }
1.113 markus 783: nc = channel_new(rtype,
1.103 markus 784: nextstate, newsock, newsock, -1,
1.41 markus 785: c->local_window_max, c->local_maxpacket,
1.103 markus 786: 0, xstrdup(rtype), 1);
787: if (nc == NULL) {
1.113 markus 788: error("channel_post_port_listener: no new channel:");
789: close(newsock);
1.103 markus 790: return;
1.41 markus 791: }
1.103 markus 792: nc->listening_port = c->listening_port;
793: nc->host_port = c->host_port;
794: strlcpy(nc->path, c->path, sizeof(nc->path));
795:
796: if (nextstate != SSH_CHANNEL_DYNAMIC)
797: port_open_helper(nc, rtype);
1.41 markus 798: }
799: }
1.25 markus 800:
1.41 markus 801: /*
802: * This is the authentication agent socket listening for connections from
803: * clients.
804: */
805: void
806: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
807: {
1.113 markus 808: Channel *nc;
809: int newsock;
1.41 markus 810: struct sockaddr addr;
811: socklen_t addrlen;
1.25 markus 812:
1.41 markus 813: if (FD_ISSET(c->sock, readset)) {
814: addrlen = sizeof(addr);
815: newsock = accept(c->sock, &addr, &addrlen);
816: if (newsock < 0) {
817: error("accept from auth socket: %.100s", strerror(errno));
818: return;
819: }
1.113 markus 820: nc = channel_new("accepted auth socket",
1.73 markus 821: SSH_CHANNEL_OPENING, newsock, newsock, -1,
822: c->local_window_max, c->local_maxpacket,
823: 0, xstrdup("accepted auth socket"), 1);
1.113 markus 824: if (nc == NULL) {
825: error("channel_post_auth_listener: channel_new failed");
826: close(newsock);
827: }
1.73 markus 828: if (compat20) {
829: packet_start(SSH2_MSG_CHANNEL_OPEN);
830: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 831: packet_put_int(nc->self);
1.73 markus 832: packet_put_int(c->local_window_max);
833: packet_put_int(c->local_maxpacket);
834: } else {
835: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 836: packet_put_int(nc->self);
1.73 markus 837: }
1.41 markus 838: packet_send();
839: }
840: }
1.25 markus 841:
1.75 markus 842: void
843: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
844: {
1.114 ! markus 845: int err = 0;
! 846: int sz = sizeof(err);
! 847:
1.75 markus 848: if (FD_ISSET(c->sock, writeset)) {
1.114 ! markus 849: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
! 850: &sz) < 0) {
! 851: err = errno;
! 852: error("getsockopt SO_ERROR failed");
! 853: }
! 854: if (err == 0) {
! 855: debug("channel %d: connected", c->self);
! 856: c->type = SSH_CHANNEL_OPEN;
! 857: if (compat20) {
! 858: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
! 859: packet_put_int(c->remote_id);
! 860: packet_put_int(c->self);
! 861: packet_put_int(c->local_window);
! 862: packet_put_int(c->local_maxpacket);
! 863: } else {
! 864: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
! 865: packet_put_int(c->remote_id);
! 866: packet_put_int(c->self);
! 867: }
1.75 markus 868: } else {
1.114 ! markus 869: debug("channel %d: not connected: %s",
! 870: c->self, strerror(err));
! 871: if (compat20) {
! 872: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
! 873: packet_put_int(c->remote_id);
! 874: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
! 875: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
! 876: packet_put_cstring(strerror(err));
! 877: packet_put_cstring("");
! 878: }
1.75 markus 879: } else {
1.114 ! markus 880: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
! 881: packet_put_int(c->remote_id);
1.75 markus 882: }
1.114 ! markus 883: chan_mark_dead(c);
1.75 markus 884: }
1.114 ! markus 885: packet_send();
1.75 markus 886: }
887: }
888:
1.41 markus 889: int
890: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
891: {
892: char buf[16*1024];
893: int len;
1.25 markus 894:
1.41 markus 895: if (c->rfd != -1 &&
896: FD_ISSET(c->rfd, readset)) {
897: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 898: if (len < 0 && (errno == EINTR || errno == EAGAIN))
899: return 1;
1.41 markus 900: if (len <= 0) {
1.51 markus 901: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 902: c->self, c->rfd, len);
1.104 markus 903: if (c->type != SSH_CHANNEL_OPEN) {
904: debug("channel %d: not open", c->self);
1.113 markus 905: chan_mark_dead(c);
1.103 markus 906: return -1;
1.104 markus 907: } else if (compat13) {
1.41 markus 908: buffer_consume(&c->output, buffer_len(&c->output));
909: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.105 markus 910: debug("channel %d: status set to input draining.", c->self);
1.25 markus 911: } else {
1.41 markus 912: chan_read_failed(c);
1.25 markus 913: }
1.41 markus 914: return -1;
915: }
1.65 markus 916: if(c->input_filter != NULL) {
1.66 markus 917: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 918: debug("channel %d: filter stops", c->self);
1.65 markus 919: chan_read_failed(c);
920: }
921: } else {
922: buffer_append(&c->input, buf, len);
923: }
1.41 markus 924: }
925: return 1;
926: }
927: int
928: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
929: {
1.95 markus 930: struct termios tio;
1.41 markus 931: int len;
1.25 markus 932:
1.41 markus 933: /* Send buffered output data to the socket. */
934: if (c->wfd != -1 &&
935: FD_ISSET(c->wfd, writeset) &&
936: buffer_len(&c->output) > 0) {
937: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 938: buffer_len(&c->output));
939: if (len < 0 && (errno == EINTR || errno == EAGAIN))
940: return 1;
1.41 markus 941: if (len <= 0) {
1.104 markus 942: if (c->type != SSH_CHANNEL_OPEN) {
943: debug("channel %d: not open", c->self);
1.113 markus 944: chan_mark_dead(c);
1.104 markus 945: return -1;
946: } else if (compat13) {
1.41 markus 947: buffer_consume(&c->output, buffer_len(&c->output));
1.105 markus 948: debug("channel %d: status set to input draining.", c->self);
1.41 markus 949: c->type = SSH_CHANNEL_INPUT_DRAINING;
950: } else {
951: chan_write_failed(c);
952: }
953: return -1;
1.91 markus 954: }
955: if (compat20 && c->isatty) {
956: if (tcgetattr(c->wfd, &tio) == 0 &&
957: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
958: /*
959: * Simulate echo to reduce the impact of
1.96 markus 960: * traffic analysis. We need to match the
1.95 markus 961: * size of a SSH2_MSG_CHANNEL_DATA message
962: * (4 byte channel id + data)
1.91 markus 963: */
1.95 markus 964: packet_send_ignore(4 + len);
1.91 markus 965: packet_send();
966: }
1.25 markus 967: }
1.41 markus 968: buffer_consume(&c->output, len);
1.44 markus 969: if (compat20 && len > 0) {
970: c->local_consumed += len;
971: }
972: }
973: return 1;
974: }
975: int
976: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
977: {
978: char buf[16*1024];
979: int len;
980:
1.45 markus 981: /** XXX handle drain efd, too */
1.44 markus 982: if (c->efd != -1) {
983: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
984: FD_ISSET(c->efd, writeset) &&
985: buffer_len(&c->extended) > 0) {
986: len = write(c->efd, buffer_ptr(&c->extended),
987: buffer_len(&c->extended));
1.70 markus 988: debug2("channel %d: written %d to efd %d",
1.44 markus 989: c->self, len, c->efd);
1.93 markus 990: if (len < 0 && (errno == EINTR || errno == EAGAIN))
991: return 1;
992: if (len <= 0) {
993: debug2("channel %d: closing write-efd %d",
994: c->self, c->efd);
995: close(c->efd);
996: c->efd = -1;
997: } else {
1.44 markus 998: buffer_consume(&c->extended, len);
999: c->local_consumed += len;
1000: }
1001: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1002: FD_ISSET(c->efd, readset)) {
1003: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1004: debug2("channel %d: read %d from efd %d",
1.44 markus 1005: c->self, len, c->efd);
1.93 markus 1006: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1007: return 1;
1008: if (len <= 0) {
1009: debug2("channel %d: closing read-efd %d",
1.45 markus 1010: c->self, c->efd);
1011: close(c->efd);
1012: c->efd = -1;
1.93 markus 1013: } else {
1.44 markus 1014: buffer_append(&c->extended, buf, len);
1.93 markus 1015: }
1.44 markus 1016: }
1017: }
1018: return 1;
1019: }
1020: int
1.93 markus 1021: channel_check_window(Channel *c)
1.44 markus 1022: {
1.104 markus 1023: if (c->type == SSH_CHANNEL_OPEN &&
1024: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1025: c->local_window < c->local_window_max/2 &&
1026: c->local_consumed > 0) {
1027: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1028: packet_put_int(c->remote_id);
1029: packet_put_int(c->local_consumed);
1030: packet_send();
1.70 markus 1031: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1032: c->self, c->local_window,
1033: c->local_consumed);
1034: c->local_window += c->local_consumed;
1035: c->local_consumed = 0;
1.1 deraadt 1036: }
1.41 markus 1037: return 1;
1.1 deraadt 1038: }
1039:
1.41 markus 1040: void
1041: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1042: {
1043: channel_handle_rfd(c, readset, writeset);
1044: channel_handle_wfd(c, readset, writeset);
1045: }
1.1 deraadt 1046:
1.41 markus 1047: void
1.44 markus 1048: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1049: {
1050: channel_handle_rfd(c, readset, writeset);
1051: channel_handle_wfd(c, readset, writeset);
1052: channel_handle_efd(c, readset, writeset);
1.93 markus 1053:
1054: channel_check_window(c);
1.44 markus 1055: }
1056:
1057: void
1.41 markus 1058: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1059: {
1.41 markus 1060: int len;
1061: /* Send buffered output data to the socket. */
1062: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1063: len = write(c->sock, buffer_ptr(&c->output),
1064: buffer_len(&c->output));
1065: if (len <= 0)
1066: buffer_consume(&c->output, buffer_len(&c->output));
1067: else
1068: buffer_consume(&c->output, len);
1069: }
1070: }
1.25 markus 1071:
1.41 markus 1072: void
1.44 markus 1073: channel_handler_init_20(void)
1074: {
1075: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1076: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1077: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1078: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1079: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1080: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1081: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1082: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1083:
1084: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1085: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1086: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1087: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1088: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1089: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1090: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1091: }
1092:
1093: void
1.41 markus 1094: channel_handler_init_13(void)
1095: {
1096: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1097: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1098: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1099: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1100: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1101: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1102: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1103: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1104: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1105:
1.41 markus 1106: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1107: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1108: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1109: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1110: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1111: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1112: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1113: }
1.25 markus 1114:
1.41 markus 1115: void
1116: channel_handler_init_15(void)
1117: {
1118: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1119: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1120: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1121: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1122: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1123: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1124: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1125:
1.41 markus 1126: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1127: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1128: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1129: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1130: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1131: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1132: }
1.27 markus 1133:
1.41 markus 1134: void
1135: channel_handler_init(void)
1136: {
1137: int i;
1138: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1139: channel_pre[i] = NULL;
1140: channel_post[i] = NULL;
1141: }
1.44 markus 1142: if (compat20)
1143: channel_handler_init_20();
1144: else if (compat13)
1.41 markus 1145: channel_handler_init_13();
1146: else
1147: channel_handler_init_15();
1148: }
1.25 markus 1149:
1.49 markus 1150: void
1.41 markus 1151: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1152: {
1153: static int did_init = 0;
1154: int i;
1155: Channel *c;
1.25 markus 1156:
1.41 markus 1157: if (!did_init) {
1158: channel_handler_init();
1159: did_init = 1;
1160: }
1161: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1162: c = channels[i];
1163: if (c == NULL)
1.41 markus 1164: continue;
1165: if (ftab[c->type] == NULL)
1.25 markus 1166: continue;
1.41 markus 1167: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1168: if (chan_is_dead(c)) {
1169: /*
1170: * we have to remove the fd's from the select mask
1171: * before the channels are free'd and the fd's are
1172: * closed
1173: */
1174: if (c->wfd != -1)
1175: FD_CLR(c->wfd, writeset);
1176: if (c->rfd != -1)
1177: FD_CLR(c->rfd, readset);
1178: if (c->efd != -1) {
1179: if (c->extended_usage == CHAN_EXTENDED_READ)
1180: FD_CLR(c->efd, readset);
1181: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1182: FD_CLR(c->efd, writeset);
1183: }
1.113 markus 1184: channel_free(c);
1.93 markus 1185: }
1.1 deraadt 1186: }
1187: }
1188:
1.49 markus 1189: void
1.100 markus 1190: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1191: int rekeying)
1.41 markus 1192: {
1.84 markus 1193: int n;
1194: u_int sz;
1195:
1196: n = MAX(*maxfdp, channel_max_fd);
1197:
1198: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1199: if (*readsetp == NULL || n > *maxfdp) {
1200: if (*readsetp)
1201: xfree(*readsetp);
1202: if (*writesetp)
1203: xfree(*writesetp);
1204: *readsetp = xmalloc(sz);
1205: *writesetp = xmalloc(sz);
1206: *maxfdp = n;
1207: }
1208: memset(*readsetp, 0, sz);
1209: memset(*writesetp, 0, sz);
1210:
1.100 markus 1211: if (!rekeying)
1212: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1213: }
1214:
1.49 markus 1215: void
1.41 markus 1216: channel_after_select(fd_set * readset, fd_set * writeset)
1217: {
1218: channel_handler(channel_post, readset, writeset);
1219: }
1220:
1.84 markus 1221: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1222:
1.49 markus 1223: void
1.25 markus 1224: channel_output_poll()
1.1 deraadt 1225: {
1.25 markus 1226: int len, i;
1.41 markus 1227: Channel *c;
1.1 deraadt 1228:
1.25 markus 1229: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1230:
1231: c = channels[i];
1232: if (c == NULL)
1233: continue;
1.37 markus 1234:
1.27 markus 1235: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1236: if (compat13) {
1.41 markus 1237: if (c->type != SSH_CHANNEL_OPEN &&
1238: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1239: continue;
1240: } else {
1.41 markus 1241: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1242: continue;
1243: }
1.46 markus 1244: if (compat20 &&
1245: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1246: /* XXX is this true? */
1.97 markus 1247: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1248: continue;
1249: }
1.25 markus 1250:
1251: /* Get the amount of buffered data for this channel. */
1.93 markus 1252: if ((c->istate == CHAN_INPUT_OPEN ||
1253: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1254: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1255: /* Send some data for the other side over the secure connection. */
1.44 markus 1256: if (compat20) {
1257: if (len > c->remote_window)
1258: len = c->remote_window;
1259: if (len > c->remote_maxpacket)
1260: len = c->remote_maxpacket;
1.25 markus 1261: } else {
1.44 markus 1262: if (packet_is_interactive()) {
1263: if (len > 1024)
1264: len = 512;
1265: } else {
1266: /* Keep the packets at reasonable size. */
1267: if (len > packet_get_maxsize()/2)
1268: len = packet_get_maxsize()/2;
1269: }
1.25 markus 1270: }
1.41 markus 1271: if (len > 0) {
1.44 markus 1272: packet_start(compat20 ?
1273: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1274: packet_put_int(c->remote_id);
1275: packet_put_string(buffer_ptr(&c->input), len);
1276: packet_send();
1277: buffer_consume(&c->input, len);
1278: c->remote_window -= len;
1279: }
1280: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1281: if (compat13)
1282: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1283: /*
1284: * input-buffer is empty and read-socket shutdown:
1285: * tell peer, that we will not send more data: send IEOF
1286: */
1.41 markus 1287: chan_ibuf_empty(c);
1.25 markus 1288: }
1.44 markus 1289: /* Send extended data, i.e. stderr */
1290: if (compat20 &&
1291: c->remote_window > 0 &&
1292: (len = buffer_len(&c->extended)) > 0 &&
1293: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1294: debug2("channel %d: rwin %d elen %d euse %d",
1295: c->self, c->remote_window, buffer_len(&c->extended),
1296: c->extended_usage);
1.44 markus 1297: if (len > c->remote_window)
1298: len = c->remote_window;
1299: if (len > c->remote_maxpacket)
1300: len = c->remote_maxpacket;
1301: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1302: packet_put_int(c->remote_id);
1303: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1304: packet_put_string(buffer_ptr(&c->extended), len);
1305: packet_send();
1306: buffer_consume(&c->extended, len);
1307: c->remote_window -= len;
1.93 markus 1308: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1309: }
1.25 markus 1310: }
1.1 deraadt 1311: }
1312:
1.27 markus 1313: /*
1314: * This is called when a packet of type CHANNEL_DATA has just been received.
1315: * The message type has already been consumed, but channel number and data is
1316: * still there.
1317: */
1.1 deraadt 1318:
1.49 markus 1319: void
1.69 markus 1320: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1321: {
1.37 markus 1322: int id;
1.25 markus 1323: char *data;
1.77 markus 1324: u_int data_len;
1.41 markus 1325: Channel *c;
1.25 markus 1326:
1327: /* Get the channel number and verify it. */
1.37 markus 1328: id = packet_get_int();
1.41 markus 1329: c = channel_lookup(id);
1330: if (c == NULL)
1.37 markus 1331: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1332:
1333: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1334: if (c->type != SSH_CHANNEL_OPEN &&
1335: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1336: return;
1337:
1338: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1339: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1340: return;
1341:
1342: /* Get the data. */
1343: data = packet_get_string(&data_len);
1.48 markus 1344: packet_done();
1.41 markus 1345:
1.44 markus 1346: if (compat20){
1347: if (data_len > c->local_maxpacket) {
1348: log("channel %d: rcvd big packet %d, maxpack %d",
1349: c->self, data_len, c->local_maxpacket);
1350: }
1351: if (data_len > c->local_window) {
1352: log("channel %d: rcvd too much data %d, win %d",
1353: c->self, data_len, c->local_window);
1354: xfree(data);
1355: return;
1356: }
1357: c->local_window -= data_len;
1358: }else{
1359: packet_integrity_check(plen, 4 + 4 + data_len, type);
1360: }
1.41 markus 1361: buffer_append(&c->output, data, data_len);
1.25 markus 1362: xfree(data);
1.1 deraadt 1363: }
1.49 markus 1364: void
1.69 markus 1365: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1366: {
1367: int id;
1368: int tcode;
1369: char *data;
1.77 markus 1370: u_int data_len;
1.44 markus 1371: Channel *c;
1372:
1373: /* Get the channel number and verify it. */
1374: id = packet_get_int();
1375: c = channel_lookup(id);
1376:
1377: if (c == NULL)
1378: packet_disconnect("Received extended_data for bad channel %d.", id);
1379: if (c->type != SSH_CHANNEL_OPEN) {
1380: log("channel %d: ext data for non open", id);
1381: return;
1382: }
1383: tcode = packet_get_int();
1384: if (c->efd == -1 ||
1385: c->extended_usage != CHAN_EXTENDED_WRITE ||
1386: tcode != SSH2_EXTENDED_DATA_STDERR) {
1387: log("channel %d: bad ext data", c->self);
1388: return;
1389: }
1390: data = packet_get_string(&data_len);
1.48 markus 1391: packet_done();
1.44 markus 1392: if (data_len > c->local_window) {
1393: log("channel %d: rcvd too much extended_data %d, win %d",
1394: c->self, data_len, c->local_window);
1395: xfree(data);
1396: return;
1397: }
1.70 markus 1398: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1399: c->local_window -= data_len;
1400: buffer_append(&c->extended, data, data_len);
1401: xfree(data);
1402: }
1403:
1.1 deraadt 1404:
1.27 markus 1405: /*
1406: * Returns true if no channel has too much buffered data, and false if one or
1407: * more channel is overfull.
1408: */
1.1 deraadt 1409:
1.49 markus 1410: int
1.25 markus 1411: channel_not_very_much_buffered_data()
1.1 deraadt 1412: {
1.77 markus 1413: u_int i;
1.41 markus 1414: Channel *c;
1.25 markus 1415:
1416: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1417: c = channels[i];
1418: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1419: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1420: debug("channel %d: big input buffer %d",
1421: c->self, buffer_len(&c->input));
1.25 markus 1422: return 0;
1.41 markus 1423: }
1424: if (buffer_len(&c->output) > packet_get_maxsize()) {
1425: debug("channel %d: big output buffer %d",
1426: c->self, buffer_len(&c->output));
1.25 markus 1427: return 0;
1.41 markus 1428: }
1.25 markus 1429: }
1.1 deraadt 1430: }
1.25 markus 1431: return 1;
1.1 deraadt 1432: }
1433:
1.49 markus 1434: void
1.69 markus 1435: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1436: {
1437: int id;
1438: Channel *c;
1439:
1440: packet_integrity_check(plen, 4, type);
1441:
1442: id = packet_get_int();
1443: c = channel_lookup(id);
1444: if (c == NULL)
1445: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1446: chan_rcvd_ieof(c);
1447: }
1.1 deraadt 1448:
1.49 markus 1449: void
1.69 markus 1450: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1451: {
1.41 markus 1452: int id;
1453: Channel *c;
1.1 deraadt 1454:
1.41 markus 1455: packet_integrity_check(plen, 4, type);
1456:
1457: id = packet_get_int();
1458: c = channel_lookup(id);
1459: if (c == NULL)
1460: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1461:
1462: /*
1463: * Send a confirmation that we have closed the channel and no more
1464: * data is coming for it.
1465: */
1.25 markus 1466: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1467: packet_put_int(c->remote_id);
1.25 markus 1468: packet_send();
1469:
1.27 markus 1470: /*
1471: * If the channel is in closed state, we have sent a close request,
1472: * and the other side will eventually respond with a confirmation.
1473: * Thus, we cannot free the channel here, because then there would be
1474: * no-one to receive the confirmation. The channel gets freed when
1475: * the confirmation arrives.
1476: */
1.41 markus 1477: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1478: /*
1479: * Not a closed channel - mark it as draining, which will
1480: * cause it to be freed later.
1481: */
1.41 markus 1482: buffer_consume(&c->input, buffer_len(&c->input));
1483: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1484: }
1.1 deraadt 1485: }
1486:
1.41 markus 1487: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1488: void
1.69 markus 1489: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1490: {
1491: int id = packet_get_int();
1492: Channel *c = channel_lookup(id);
1493: packet_integrity_check(plen, 4, type);
1494: if (c == NULL)
1495: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1496: chan_rcvd_oclose(c);
1497: }
1.1 deraadt 1498:
1.49 markus 1499: void
1.69 markus 1500: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1501: {
1.41 markus 1502: int id = packet_get_int();
1503: Channel *c = channel_lookup(id);
1.1 deraadt 1504:
1.48 markus 1505: packet_done();
1.41 markus 1506: if (c == NULL)
1507: packet_disconnect("Received close confirmation for "
1508: "out-of-range channel %d.", id);
1509: if (c->type != SSH_CHANNEL_CLOSED)
1510: packet_disconnect("Received close confirmation for "
1511: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 1512: channel_free(c);
1.1 deraadt 1513: }
1514:
1.49 markus 1515: void
1.69 markus 1516: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1517: {
1.41 markus 1518: int id, remote_id;
1519: Channel *c;
1.1 deraadt 1520:
1.44 markus 1521: if (!compat20)
1522: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1523:
1.41 markus 1524: id = packet_get_int();
1525: c = channel_lookup(id);
1.25 markus 1526:
1.41 markus 1527: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1528: packet_disconnect("Received open confirmation for "
1529: "non-opening channel %d.", id);
1530: remote_id = packet_get_int();
1.27 markus 1531: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1532: c->remote_id = remote_id;
1533: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1534:
1535: if (compat20) {
1536: c->remote_window = packet_get_int();
1537: c->remote_maxpacket = packet_get_int();
1.48 markus 1538: packet_done();
1.44 markus 1539: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1540: debug2("callback start");
1.44 markus 1541: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1542: debug2("callback done");
1.44 markus 1543: }
1544: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1545: c->remote_window, c->remote_maxpacket);
1546: }
1.1 deraadt 1547: }
1548:
1.114 ! markus 1549: char *
! 1550: reason2txt(int reason)
! 1551: {
! 1552: switch(reason) {
! 1553: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
! 1554: return "administratively prohibited";
! 1555: case SSH2_OPEN_CONNECT_FAILED:
! 1556: return "connect failed";
! 1557: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
! 1558: return "unknown channel type";
! 1559: case SSH2_OPEN_RESOURCE_SHORTAGE:
! 1560: return "resource shortage";
! 1561: }
! 1562: return "unkown reason";
! 1563: }
! 1564:
1.49 markus 1565: void
1.69 markus 1566: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1567: {
1.86 markus 1568: int id, reason;
1569: char *msg = NULL, *lang = NULL;
1.41 markus 1570: Channel *c;
1571:
1.44 markus 1572: if (!compat20)
1573: packet_integrity_check(plen, 4, type);
1.41 markus 1574:
1575: id = packet_get_int();
1576: c = channel_lookup(id);
1.25 markus 1577:
1.41 markus 1578: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1579: packet_disconnect("Received open failure for "
1580: "non-opening channel %d.", id);
1.44 markus 1581: if (compat20) {
1.86 markus 1582: reason = packet_get_int();
1.110 markus 1583: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1584: msg = packet_get_string(NULL);
1585: lang = packet_get_string(NULL);
1586: }
1.48 markus 1587: packet_done();
1.114 ! markus 1588: log("channel %d: open failed: %s%s%s", id,
! 1589: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 1590: if (msg != NULL)
1591: xfree(msg);
1592: if (lang != NULL)
1593: xfree(lang);
1.44 markus 1594: }
1.25 markus 1595: /* Free the channel. This will also close the socket. */
1.113 markus 1596: channel_free(c);
1.1 deraadt 1597: }
1598:
1.44 markus 1599: void
1.69 markus 1600: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1601: {
1602: int id;
1603: Channel *c;
1604:
1605: id = packet_get_int();
1606: c = channel_lookup(id);
1607:
1608: if (c == NULL ||
1609: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1610: packet_disconnect("Received request for "
1611: "non-open channel %d.", id);
1612: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1613: debug2("callback start");
1.44 markus 1614: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1615: debug2("callback done");
1.44 markus 1616: } else {
1617: char *service = packet_get_string(NULL);
1.94 markus 1618: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1619: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1620: xfree(service);
1621: }
1622: }
1623:
1.49 markus 1624: void
1.69 markus 1625: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1626: {
1627: Channel *c;
1628: int id, adjust;
1629:
1630: if (!compat20)
1631: return;
1632:
1633: /* Get the channel number and verify it. */
1634: id = packet_get_int();
1635: c = channel_lookup(id);
1636:
1637: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1638: log("Received window adjust for "
1639: "non-open channel %d.", id);
1640: return;
1641: }
1642: adjust = packet_get_int();
1.48 markus 1643: packet_done();
1.70 markus 1644: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1645: c->remote_window += adjust;
1646: }
1647:
1.27 markus 1648: /*
1649: * Stops listening for channels, and removes any unix domain sockets that we
1650: * might have.
1651: */
1.1 deraadt 1652:
1.49 markus 1653: void
1.25 markus 1654: channel_stop_listening()
1.1 deraadt 1655: {
1.25 markus 1656: int i;
1.113 markus 1657: Channel *c;
1658:
1.25 markus 1659: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1660: c = channels[i];
1661: if (c != NULL) {
1662: switch (c->type) {
1663: case SSH_CHANNEL_AUTH_SOCKET:
1664: close(c->sock);
1665: unlink(c->path);
1666: channel_free(c);
1667: break;
1668: case SSH_CHANNEL_PORT_LISTENER:
1669: case SSH_CHANNEL_RPORT_LISTENER:
1670: case SSH_CHANNEL_X11_LISTENER:
1671: close(c->sock);
1672: channel_free(c);
1673: break;
1674: default:
1675: break;
1676: }
1.25 markus 1677: }
1.1 deraadt 1678: }
1679: }
1680:
1.27 markus 1681: /*
1.52 markus 1682: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1683: * descriptors after a fork.
1684: */
1.1 deraadt 1685:
1.49 markus 1686: void
1.25 markus 1687: channel_close_all()
1.1 deraadt 1688: {
1.25 markus 1689: int i;
1.113 markus 1690:
1.52 markus 1691: for (i = 0; i < channels_alloc; i++)
1.113 markus 1692: if (channels[i] != NULL)
1693: channel_close_fds(channels[i]);
1.1 deraadt 1694: }
1695:
1696: /* Returns true if any channel is still open. */
1697:
1.49 markus 1698: int
1.25 markus 1699: channel_still_open()
1.1 deraadt 1700: {
1.113 markus 1701: int i;
1702: Channel *c;
1703:
1704: for (i = 0; i < channels_alloc; i++) {
1705: c = channels[i];
1706: if (c == NULL)
1707: continue;
1708: switch (c->type) {
1.25 markus 1709: case SSH_CHANNEL_X11_LISTENER:
1710: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1711: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1712: case SSH_CHANNEL_CLOSED:
1713: case SSH_CHANNEL_AUTH_SOCKET:
1.103 markus 1714: case SSH_CHANNEL_DYNAMIC:
1.114 ! markus 1715: case SSH_CHANNEL_CONNECTING:
1.25 markus 1716: continue;
1.44 markus 1717: case SSH_CHANNEL_LARVAL:
1718: if (!compat20)
1719: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1720: continue;
1.25 markus 1721: case SSH_CHANNEL_OPENING:
1722: case SSH_CHANNEL_OPEN:
1723: case SSH_CHANNEL_X11_OPEN:
1724: return 1;
1725: case SSH_CHANNEL_INPUT_DRAINING:
1726: case SSH_CHANNEL_OUTPUT_DRAINING:
1727: if (!compat13)
1728: fatal("cannot happen: OUT_DRAIN");
1729: return 1;
1730: default:
1.113 markus 1731: fatal("channel_still_open: bad channel type %d", c->type);
1.25 markus 1732: /* NOTREACHED */
1733: }
1.113 markus 1734: }
1.25 markus 1735: return 0;
1.1 deraadt 1736: }
1.107 beck 1737:
1738: /* Returns the id of an open channel suitable for keepaliving */
1739:
1740: int
1741: channel_find_open()
1742: {
1.113 markus 1743: int i;
1744: Channel *c;
1745:
1746: for (i = 0; i < channels_alloc; i++) {
1747: c = channels[i];
1748: if (c == NULL)
1749: continue;
1750: switch (c->type) {
1.107 beck 1751: case SSH_CHANNEL_CLOSED:
1752: case SSH_CHANNEL_DYNAMIC:
1753: case SSH_CHANNEL_X11_LISTENER:
1754: case SSH_CHANNEL_PORT_LISTENER:
1755: case SSH_CHANNEL_RPORT_LISTENER:
1756: case SSH_CHANNEL_OPENING:
1.114 ! markus 1757: case SSH_CHANNEL_CONNECTING:
1.108 markus 1758: continue;
1759: case SSH_CHANNEL_LARVAL:
1760: case SSH_CHANNEL_AUTH_SOCKET:
1.107 beck 1761: case SSH_CHANNEL_OPEN:
1762: case SSH_CHANNEL_X11_OPEN:
1763: return i;
1764: case SSH_CHANNEL_INPUT_DRAINING:
1765: case SSH_CHANNEL_OUTPUT_DRAINING:
1766: if (!compat13)
1767: fatal("cannot happen: OUT_DRAIN");
1768: return i;
1769: default:
1.113 markus 1770: fatal("channel_find_open: bad channel type %d", c->type);
1.107 beck 1771: /* NOTREACHED */
1772: }
1.113 markus 1773: }
1.107 beck 1774: return -1;
1775: }
1776:
1.1 deraadt 1777:
1.27 markus 1778: /*
1779: * Returns a message describing the currently open forwarded connections,
1780: * suitable for sending to the client. The message contains crlf pairs for
1781: * newlines.
1782: */
1.1 deraadt 1783:
1.25 markus 1784: char *
1785: channel_open_message()
1.1 deraadt 1786: {
1.25 markus 1787: Buffer buffer;
1.113 markus 1788: Channel *c;
1789: char buf[1024], *cp;
1.25 markus 1790: int i;
1791:
1792: buffer_init(&buffer);
1793: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1794: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1795: for (i = 0; i < channels_alloc; i++) {
1.113 markus 1796: c = channels[i];
1797: if (c == NULL)
1798: continue;
1.25 markus 1799: switch (c->type) {
1800: case SSH_CHANNEL_X11_LISTENER:
1801: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1802: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1803: case SSH_CHANNEL_CLOSED:
1804: case SSH_CHANNEL_AUTH_SOCKET:
1805: continue;
1.44 markus 1806: case SSH_CHANNEL_LARVAL:
1.25 markus 1807: case SSH_CHANNEL_OPENING:
1.75 markus 1808: case SSH_CHANNEL_CONNECTING:
1.103 markus 1809: case SSH_CHANNEL_DYNAMIC:
1.25 markus 1810: case SSH_CHANNEL_OPEN:
1811: case SSH_CHANNEL_X11_OPEN:
1812: case SSH_CHANNEL_INPUT_DRAINING:
1813: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1814: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1815: c->self, c->remote_name,
1816: c->type, c->remote_id,
1817: c->istate, buffer_len(&c->input),
1.41 markus 1818: c->ostate, buffer_len(&c->output),
1819: c->rfd, c->wfd);
1.25 markus 1820: buffer_append(&buffer, buf, strlen(buf));
1821: continue;
1822: default:
1.41 markus 1823: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1824: /* NOTREACHED */
1825: }
1826: }
1827: buffer_append(&buffer, "\0", 1);
1828: cp = xstrdup(buffer_ptr(&buffer));
1829: buffer_free(&buffer);
1830: return cp;
1.1 deraadt 1831: }
1832:
1.27 markus 1833: /*
1834: * Initiate forwarding of connections to local port "port" through the secure
1835: * channel to host:port from remote side.
1836: */
1.87 markus 1837: int
1.73 markus 1838: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1839: u_short port_to_connect, int gateway_ports)
1840: {
1.87 markus 1841: return channel_request_forwarding(
1.73 markus 1842: NULL, listen_port,
1843: host_to_connect, port_to_connect,
1844: gateway_ports, /*remote_fwd*/ 0);
1845: }
1.1 deraadt 1846:
1.73 markus 1847: /*
1848: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1849: * (SSH_CHANNEL_RPORT_LISTENER).
1850: */
1.87 markus 1851: int
1.73 markus 1852: channel_request_forwarding(
1853: const char *listen_address, u_short listen_port,
1854: const char *host_to_connect, u_short port_to_connect,
1855: int gateway_ports, int remote_fwd)
1.25 markus 1856: {
1.113 markus 1857: Channel *c;
1858: int success, sock, on = 1, ctype;
1.35 markus 1859: struct addrinfo hints, *ai, *aitop;
1860: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1861: const char *host;
1.28 markus 1862: struct linger linger;
1.25 markus 1863:
1.87 markus 1864: success = 0;
1865:
1.73 markus 1866: if (remote_fwd) {
1867: host = listen_address;
1.89 stevesk 1868: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1869: } else {
1870: host = host_to_connect;
1871: ctype =SSH_CHANNEL_PORT_LISTENER;
1872: }
1873:
1.113 markus 1874: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 1875: error("Forward host name too long.");
1876: return success;
1877: }
1.25 markus 1878:
1.73 markus 1879: /* XXX listen_address is currently ignored */
1.28 markus 1880: /*
1.35 markus 1881: * getaddrinfo returns a loopback address if the hostname is
1882: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1883: */
1.35 markus 1884: memset(&hints, 0, sizeof(hints));
1885: hints.ai_family = IPv4or6;
1886: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1887: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1888: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1889: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1890: packet_disconnect("getaddrinfo: fatal error");
1891:
1892: for (ai = aitop; ai; ai = ai->ai_next) {
1893: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1894: continue;
1895: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1896: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1897: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1898: continue;
1899: }
1900: /* Create a port to listen for the host. */
1901: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1902: if (sock < 0) {
1903: /* this is no error since kernel may not support ipv6 */
1904: verbose("socket: %.100s", strerror(errno));
1905: continue;
1906: }
1907: /*
1908: * Set socket options. We would like the socket to disappear
1909: * as soon as it has been closed for whatever reason.
1910: */
1911: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1912: linger.l_onoff = 1;
1913: linger.l_linger = 5;
1914: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1915: debug("Local forwarding listening on %s port %s.", ntop, strport);
1916:
1917: /* Bind the socket to the address. */
1918: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1919: /* address can be in use ipv6 address is already bound */
1920: verbose("bind: %.100s", strerror(errno));
1921: close(sock);
1922: continue;
1923: }
1924: /* Start listening for connections on the socket. */
1925: if (listen(sock, 5) < 0) {
1926: error("listen: %.100s", strerror(errno));
1927: close(sock);
1928: continue;
1929: }
1930: /* Allocate a channel number for the socket. */
1.113 markus 1931: c = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1932: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1933: 0, xstrdup("port listener"), 1);
1.113 markus 1934: if (c == NULL) {
1935: error("channel_request_forwarding: channel_new failed");
1936: close(sock);
1937: continue;
1938: }
1939: strlcpy(c->path, host, sizeof(c->path));
1940: c->host_port = port_to_connect;
1941: c->listening_port = listen_port;
1.35 markus 1942: success = 1;
1943: }
1944: if (success == 0)
1.87 markus 1945: error("channel_request_forwarding: cannot listen to port: %d",
1946: listen_port);
1.35 markus 1947: freeaddrinfo(aitop);
1.87 markus 1948: return success;
1.25 markus 1949: }
1.1 deraadt 1950:
1.27 markus 1951: /*
1952: * Initiate forwarding of connections to port "port" on remote host through
1953: * the secure channel to host:port from local side.
1954: */
1.1 deraadt 1955:
1.49 markus 1956: void
1.73 markus 1957: channel_request_remote_forwarding(u_short listen_port,
1958: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1959: {
1.73 markus 1960: int payload_len, type, success = 0;
1961:
1.25 markus 1962: /* Record locally that connection to this host/port is permitted. */
1963: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1964: fatal("channel_request_remote_forwarding: too many forwards");
1965:
1966: /* Send the forward request to the remote side. */
1.44 markus 1967: if (compat20) {
1968: const char *address_to_bind = "0.0.0.0";
1969: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1970: packet_put_cstring("tcpip-forward");
1971: packet_put_char(0); /* boolean: want reply */
1972: packet_put_cstring(address_to_bind);
1973: packet_put_int(listen_port);
1.73 markus 1974: packet_send();
1975: packet_write_wait();
1976: /* Assume that server accepts the request */
1977: success = 1;
1.44 markus 1978: } else {
1979: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1980: packet_put_int(listen_port);
1981: packet_put_cstring(host_to_connect);
1.44 markus 1982: packet_put_int(port_to_connect);
1983: packet_send();
1984: packet_write_wait();
1.73 markus 1985:
1986: /* Wait for response from the remote side. */
1987: type = packet_read(&payload_len);
1988: switch (type) {
1989: case SSH_SMSG_SUCCESS:
1990: success = 1;
1991: break;
1992: case SSH_SMSG_FAILURE:
1993: log("Warning: Server denied remote port forwarding.");
1994: break;
1995: default:
1996: /* Unknown packet */
1997: packet_disconnect("Protocol error for port forward request:"
1998: "received packet type %d.", type);
1999: }
2000: }
2001: if (success) {
2002: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2003: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2004: permitted_opens[num_permitted_opens].listen_port = listen_port;
2005: num_permitted_opens++;
1.44 markus 2006: }
1.1 deraadt 2007: }
2008:
1.27 markus 2009: /*
2010: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2011: * listening for the port, and sends back a success reply (or disconnect
2012: * message if there was an error). This never returns if there was an error.
2013: */
1.1 deraadt 2014:
1.49 markus 2015: void
1.56 markus 2016: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2017: {
1.31 markus 2018: u_short port, host_port;
1.25 markus 2019: char *hostname;
1.1 deraadt 2020:
1.25 markus 2021: /* Get arguments from the packet. */
2022: port = packet_get_int();
2023: hostname = packet_get_string(NULL);
2024: host_port = packet_get_int();
2025:
1.27 markus 2026: /*
2027: * Check that an unprivileged user is not trying to forward a
2028: * privileged port.
2029: */
1.25 markus 2030: if (port < IPPORT_RESERVED && !is_root)
2031: packet_disconnect("Requested forwarding of port %d but user is not root.",
2032: port);
1.73 markus 2033: /* Initiate forwarding */
1.56 markus 2034: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2035:
2036: /* Free the argument string. */
2037: xfree(hostname);
1.1 deraadt 2038: }
2039:
1.99 markus 2040: /*
2041: * Permits opening to any host/port if permitted_opens[] is empty. This is
2042: * usually called by the server, because the user could connect to any port
2043: * anyway, and the server has no way to know but to trust the client anyway.
2044: */
2045: void
2046: channel_permit_all_opens()
2047: {
2048: if (num_permitted_opens == 0)
2049: all_opens_permitted = 1;
2050: }
2051:
1.101 markus 2052: void
1.99 markus 2053: channel_add_permitted_opens(char *host, int port)
2054: {
2055: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2056: fatal("channel_request_remote_forwarding: too many forwards");
2057: debug("allow port forwarding to host %s port %d", host, port);
2058:
2059: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2060: permitted_opens[num_permitted_opens].port_to_connect = port;
2061: num_permitted_opens++;
2062:
2063: all_opens_permitted = 0;
2064: }
2065:
1.101 markus 2066: void
1.99 markus 2067: channel_clear_permitted_opens(void)
2068: {
2069: int i;
2070:
2071: for (i = 0; i < num_permitted_opens; i++)
2072: xfree(permitted_opens[i].host_to_connect);
2073: num_permitted_opens = 0;
2074:
2075: }
2076:
2077:
2078: /* return socket to remote host, port */
1.41 markus 2079: int
1.99 markus 2080: connect_to(const char *host, u_short port)
1.41 markus 2081: {
2082: struct addrinfo hints, *ai, *aitop;
2083: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2084: int gaierr;
2085: int sock = -1;
2086:
2087: memset(&hints, 0, sizeof(hints));
2088: hints.ai_family = IPv4or6;
2089: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2090: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2091: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2092: error("connect_to %.100s: unknown host (%s)", host,
2093: gai_strerror(gaierr));
1.41 markus 2094: return -1;
2095: }
2096: for (ai = aitop; ai; ai = ai->ai_next) {
2097: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2098: continue;
2099: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2100: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2101: error("connect_to: getnameinfo failed");
1.41 markus 2102: continue;
2103: }
2104: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2105: if (sock < 0) {
2106: error("socket: %.100s", strerror(errno));
2107: continue;
2108: }
1.80 markus 2109: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2110: fatal("connect_to: F_SETFL: %s", strerror(errno));
2111: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2112: errno != EINPROGRESS) {
1.99 markus 2113: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2114: strerror(errno));
2115: close(sock);
1.89 stevesk 2116: continue; /* fail -- try next */
1.41 markus 2117: }
2118: break; /* success */
2119:
2120: }
2121: freeaddrinfo(aitop);
2122: if (!ai) {
1.99 markus 2123: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2124: return -1;
2125: }
2126: /* success */
2127: return sock;
2128: }
1.99 markus 2129:
1.73 markus 2130: int
2131: channel_connect_by_listen_adress(u_short listen_port)
2132: {
2133: int i;
1.99 markus 2134:
1.73 markus 2135: for (i = 0; i < num_permitted_opens; i++)
2136: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2137: return connect_to(
1.73 markus 2138: permitted_opens[i].host_to_connect,
2139: permitted_opens[i].port_to_connect);
1.74 markus 2140: error("WARNING: Server requests forwarding for unknown listen_port %d",
2141: listen_port);
1.73 markus 2142: return -1;
2143: }
2144:
1.99 markus 2145: /* Check if connecting to that port is permitted and connect. */
2146: int
2147: channel_connect_to(const char *host, u_short port)
2148: {
2149: int i, permit;
2150:
2151: permit = all_opens_permitted;
2152: if (!permit) {
2153: for (i = 0; i < num_permitted_opens; i++)
2154: if (permitted_opens[i].port_to_connect == port &&
2155: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2156: permit = 1;
2157:
2158: }
2159: if (!permit) {
2160: log("Received request to connect to host %.100s port %d, "
2161: "but the request was denied.", host, port);
2162: return -1;
2163: }
2164: return connect_to(host, port);
2165: }
2166:
1.27 markus 2167: /*
2168: * This is called after receiving PORT_OPEN message. This attempts to
2169: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2170: * or CHANNEL_OPEN_FAILURE.
2171: */
1.1 deraadt 2172:
1.49 markus 2173: void
1.69 markus 2174: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2175: {
1.113 markus 2176: Channel *c = NULL;
1.31 markus 2177: u_short host_port;
1.25 markus 2178: char *host, *originator_string;
1.113 markus 2179: int remote_id, sock = -1;
1.25 markus 2180:
1.113 markus 2181: remote_id = packet_get_int();
1.99 markus 2182: host = packet_get_string(NULL);
1.25 markus 2183: host_port = packet_get_int();
2184:
1.29 markus 2185: if (have_hostname_in_open) {
1.99 markus 2186: originator_string = packet_get_string(NULL);
1.29 markus 2187: } else {
1.25 markus 2188: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 2189: }
1.99 markus 2190: packet_done();
2191: sock = channel_connect_to(host, host_port);
2192: if (sock != -1) {
1.113 markus 2193: c = channel_new("connected socket",
2194: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2195: originator_string, 1);
2196: if (c == NULL) {
2197: error("channel_input_port_open: channel_new failed");
2198: close(sock);
2199: } else {
2200: c->remote_id = remote_id;
2201: }
2202: }
2203: if (c == NULL) {
2204: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2205: packet_put_int(remote_id);
1.114 ! markus 2206: packet_send();
1.25 markus 2207: }
2208: xfree(host);
1.1 deraadt 2209: }
2210:
1.27 markus 2211: /*
2212: * Creates an internet domain socket for listening for X11 connections.
2213: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2214: * occurs.
2215: */
1.1 deraadt 2216:
1.35 markus 2217: #define NUM_SOCKS 10
2218:
1.25 markus 2219: char *
1.33 markus 2220: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2221: {
1.31 markus 2222: int display_number, sock;
2223: u_short port;
1.35 markus 2224: struct addrinfo hints, *ai, *aitop;
2225: char strport[NI_MAXSERV];
2226: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2227: char display[512];
1.25 markus 2228: char hostname[MAXHOSTNAMELEN];
2229:
1.33 markus 2230: for (display_number = x11_display_offset;
1.25 markus 2231: display_number < MAX_DISPLAYS;
2232: display_number++) {
2233: port = 6000 + display_number;
1.35 markus 2234: memset(&hints, 0, sizeof(hints));
2235: hints.ai_family = IPv4or6;
1.36 markus 2236: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2237: hints.ai_socktype = SOCK_STREAM;
2238: snprintf(strport, sizeof strport, "%d", port);
2239: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2240: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2241: return NULL;
2242: }
1.35 markus 2243: for (ai = aitop; ai; ai = ai->ai_next) {
2244: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2245: continue;
2246: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2247: if (sock < 0) {
2248: error("socket: %.100s", strerror(errno));
2249: return NULL;
2250: }
2251: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2252: debug("bind port %d: %.100s", port, strerror(errno));
2253: shutdown(sock, SHUT_RDWR);
2254: close(sock);
2255: for (n = 0; n < num_socks; n++) {
2256: shutdown(socks[n], SHUT_RDWR);
2257: close(socks[n]);
2258: }
2259: num_socks = 0;
2260: break;
2261: }
2262: socks[num_socks++] = sock;
2263: if (num_socks == NUM_SOCKS)
2264: break;
1.25 markus 2265: }
1.83 stevesk 2266: freeaddrinfo(aitop);
1.35 markus 2267: if (num_socks > 0)
2268: break;
1.25 markus 2269: }
2270: if (display_number >= MAX_DISPLAYS) {
2271: error("Failed to allocate internet-domain X11 display socket.");
2272: return NULL;
2273: }
2274: /* Start listening for connections on the socket. */
1.35 markus 2275: for (n = 0; n < num_socks; n++) {
2276: sock = socks[n];
2277: if (listen(sock, 5) < 0) {
2278: error("listen: %.100s", strerror(errno));
2279: shutdown(sock, SHUT_RDWR);
2280: close(sock);
2281: return NULL;
2282: }
1.25 markus 2283: }
1.35 markus 2284:
1.25 markus 2285: /* Set up a suitable value for the DISPLAY variable. */
2286: if (gethostname(hostname, sizeof(hostname)) < 0)
2287: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2288: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2289: display_number, screen_number);
2290:
1.35 markus 2291: /* Allocate a channel for each socket. */
2292: for (n = 0; n < num_socks; n++) {
2293: sock = socks[n];
1.51 markus 2294: (void) channel_new("x11 listener",
2295: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2296: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2297: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2298: }
1.1 deraadt 2299:
1.25 markus 2300: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2301: return xstrdup(display);
1.1 deraadt 2302: }
2303:
2304: #ifndef X_UNIX_PATH
2305: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2306: #endif
2307:
2308: static
2309: int
1.77 markus 2310: connect_local_xsocket(u_int dnr)
1.1 deraadt 2311: {
1.25 markus 2312: static const char *const x_sockets[] = {
2313: X_UNIX_PATH "%u",
2314: "/var/X/.X11-unix/X" "%u",
2315: "/usr/spool/sockets/X11/" "%u",
2316: NULL
2317: };
2318: int sock;
2319: struct sockaddr_un addr;
2320: const char *const * path;
2321:
2322: for (path = x_sockets; *path; ++path) {
2323: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2324: if (sock < 0)
2325: error("socket: %.100s", strerror(errno));
2326: memset(&addr, 0, sizeof(addr));
2327: addr.sun_family = AF_UNIX;
2328: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2329: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2330: return sock;
2331: close(sock);
2332: }
2333: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2334: return -1;
1.1 deraadt 2335: }
2336:
1.51 markus 2337: int
2338: x11_connect_display(void)
1.1 deraadt 2339: {
1.51 markus 2340: int display_number, sock = 0;
1.25 markus 2341: const char *display;
1.51 markus 2342: char buf[1024], *cp;
1.35 markus 2343: struct addrinfo hints, *ai, *aitop;
2344: char strport[NI_MAXSERV];
2345: int gaierr;
1.25 markus 2346:
2347: /* Try to open a socket for the local X server. */
2348: display = getenv("DISPLAY");
2349: if (!display) {
2350: error("DISPLAY not set.");
1.51 markus 2351: return -1;
1.25 markus 2352: }
1.27 markus 2353: /*
2354: * Now we decode the value of the DISPLAY variable and make a
2355: * connection to the real X server.
2356: */
2357:
2358: /*
2359: * Check if it is a unix domain socket. Unix domain displays are in
2360: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2361: */
1.25 markus 2362: if (strncmp(display, "unix:", 5) == 0 ||
2363: display[0] == ':') {
2364: /* Connect to the unix domain socket. */
2365: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2366: error("Could not parse display number from DISPLAY: %.100s",
2367: display);
1.51 markus 2368: return -1;
1.25 markus 2369: }
2370: /* Create a socket. */
2371: sock = connect_local_xsocket(display_number);
2372: if (sock < 0)
1.51 markus 2373: return -1;
1.25 markus 2374:
2375: /* OK, we now have a connection to the display. */
1.51 markus 2376: return sock;
1.25 markus 2377: }
1.27 markus 2378: /*
2379: * Connect to an inet socket. The DISPLAY value is supposedly
2380: * hostname:d[.s], where hostname may also be numeric IP address.
2381: */
1.25 markus 2382: strncpy(buf, display, sizeof(buf));
2383: buf[sizeof(buf) - 1] = 0;
2384: cp = strchr(buf, ':');
2385: if (!cp) {
2386: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2387: return -1;
1.25 markus 2388: }
2389: *cp = 0;
1.27 markus 2390: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2391: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2392: error("Could not parse display number from DISPLAY: %.100s",
2393: display);
1.51 markus 2394: return -1;
1.25 markus 2395: }
1.35 markus 2396:
2397: /* Look up the host address */
2398: memset(&hints, 0, sizeof(hints));
2399: hints.ai_family = IPv4or6;
2400: hints.ai_socktype = SOCK_STREAM;
2401: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2402: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2403: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2404: return -1;
1.25 markus 2405: }
1.35 markus 2406: for (ai = aitop; ai; ai = ai->ai_next) {
2407: /* Create a socket. */
2408: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2409: if (sock < 0) {
2410: debug("socket: %.100s", strerror(errno));
1.41 markus 2411: continue;
2412: }
2413: /* Connect it to the display. */
2414: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2415: debug("connect %.100s port %d: %.100s", buf,
2416: 6000 + display_number, strerror(errno));
2417: close(sock);
2418: continue;
2419: }
2420: /* Success */
2421: break;
1.35 markus 2422: }
2423: freeaddrinfo(aitop);
2424: if (!ai) {
1.49 markus 2425: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2426: strerror(errno));
1.51 markus 2427: return -1;
1.25 markus 2428: }
1.51 markus 2429: return sock;
2430: }
2431:
2432: /*
2433: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2434: * the remote channel number. We should do whatever we want, and respond
2435: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2436: */
2437:
2438: void
1.69 markus 2439: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2440: {
1.113 markus 2441: Channel *c = NULL;
2442: int remote_id, sock = 0;
1.51 markus 2443: char *remote_host;
1.25 markus 2444:
1.113 markus 2445: debug("Received X11 open request.");
1.51 markus 2446:
1.113 markus 2447: remote_id = packet_get_int();
1.51 markus 2448: if (have_hostname_in_open) {
1.113 markus 2449: remote_host = packet_get_string(NULL);
1.51 markus 2450: } else {
2451: remote_host = xstrdup("unknown (remote did not supply name)");
2452: }
1.113 markus 2453: packet_done();
1.25 markus 2454:
1.51 markus 2455: /* Obtain a connection to the real X display. */
2456: sock = x11_connect_display();
1.113 markus 2457: if (sock != -1) {
2458: /* Allocate a channel for this connection. */
2459: c = channel_new("connected x11 socket",
2460: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
2461: remote_host, 1);
2462: if (c == NULL) {
2463: error("x11_input_open: channel_new failed");
2464: close(sock);
2465: } else {
2466: c->remote_id = remote_id;
2467: }
2468: }
2469: if (c == NULL) {
1.51 markus 2470: /* Send refusal to the remote host. */
2471: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2472: packet_put_int(remote_id);
1.51 markus 2473: } else {
2474: /* Send a confirmation to the remote host. */
2475: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 2476: packet_put_int(remote_id);
2477: packet_put_int(c->self);
1.51 markus 2478: }
1.113 markus 2479: packet_send();
1.72 markus 2480: }
2481:
2482: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2483: void
2484: deny_input_open(int type, int plen, void *ctxt)
2485: {
2486: int rchan = packet_get_int();
2487: switch(type){
2488: case SSH_SMSG_AGENT_OPEN:
2489: error("Warning: ssh server tried agent forwarding.");
2490: break;
2491: case SSH_SMSG_X11_OPEN:
2492: error("Warning: ssh server tried X11 forwarding.");
2493: break;
2494: default:
2495: error("deny_input_open: type %d plen %d", type, plen);
2496: break;
2497: }
2498: error("Warning: this is probably a break in attempt by a malicious server.");
2499: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2500: packet_put_int(rchan);
2501: packet_send();
1.1 deraadt 2502: }
2503:
1.27 markus 2504: /*
2505: * Requests forwarding of X11 connections, generates fake authentication
2506: * data, and enables authentication spoofing.
2507: */
1.1 deraadt 2508:
1.49 markus 2509: void
1.51 markus 2510: x11_request_forwarding_with_spoofing(int client_session_id,
2511: const char *proto, const char *data)
1.1 deraadt 2512: {
1.77 markus 2513: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2514: u_int i, value, len;
1.25 markus 2515: char *new_data;
2516: int screen_number;
2517: const char *cp;
2518: u_int32_t rand = 0;
2519:
2520: cp = getenv("DISPLAY");
2521: if (cp)
2522: cp = strchr(cp, ':');
2523: if (cp)
2524: cp = strchr(cp, '.');
2525: if (cp)
2526: screen_number = atoi(cp + 1);
2527: else
2528: screen_number = 0;
2529:
2530: /* Save protocol name. */
2531: x11_saved_proto = xstrdup(proto);
2532:
1.27 markus 2533: /*
2534: * Extract real authentication data and generate fake data of the
2535: * same length.
2536: */
1.25 markus 2537: x11_saved_data = xmalloc(data_len);
2538: x11_fake_data = xmalloc(data_len);
2539: for (i = 0; i < data_len; i++) {
2540: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2541: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2542: if (i % 4 == 0)
2543: rand = arc4random();
2544: x11_saved_data[i] = value;
2545: x11_fake_data[i] = rand & 0xff;
2546: rand >>= 8;
2547: }
2548: x11_saved_data_len = data_len;
2549: x11_fake_data_len = data_len;
2550:
2551: /* Convert the fake data into hex. */
1.90 markus 2552: len = 2 * data_len + 1;
2553: new_data = xmalloc(len);
1.25 markus 2554: for (i = 0; i < data_len; i++)
1.90 markus 2555: snprintf(new_data + 2 * i, len - 2 * i,
2556: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2557:
2558: /* Send the request packet. */
1.51 markus 2559: if (compat20) {
2560: channel_request_start(client_session_id, "x11-req", 0);
2561: packet_put_char(0); /* XXX bool single connection */
2562: } else {
2563: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2564: }
2565: packet_put_cstring(proto);
2566: packet_put_cstring(new_data);
1.25 markus 2567: packet_put_int(screen_number);
2568: packet_send();
2569: packet_write_wait();
2570: xfree(new_data);
1.1 deraadt 2571: }
2572:
2573: /* Sends a message to the server to request authentication fd forwarding. */
2574:
1.49 markus 2575: void
1.25 markus 2576: auth_request_forwarding()
1.1 deraadt 2577: {
1.25 markus 2578: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2579: packet_send();
2580: packet_write_wait();
1.1 deraadt 2581: }
2582:
1.27 markus 2583: /*
2584: * Returns the name of the forwarded authentication socket. Returns NULL if
2585: * there is no forwarded authentication socket. The returned value points to
2586: * a static buffer.
2587: */
1.1 deraadt 2588:
1.25 markus 2589: char *
2590: auth_get_socket_name()
1.1 deraadt 2591: {
1.25 markus 2592: return channel_forwarded_auth_socket_name;
1.1 deraadt 2593: }
2594:
1.12 markus 2595: /* removes the agent forwarding socket */
2596:
1.49 markus 2597: void
1.25 markus 2598: cleanup_socket(void)
2599: {
1.78 markus 2600: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2601: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2602: }
2603:
1.27 markus 2604: /*
1.59 markus 2605: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2606: * This starts forwarding authentication requests.
2607: */
1.1 deraadt 2608:
1.59 markus 2609: int
1.25 markus 2610: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2611: {
1.113 markus 2612: Channel *nc;
2613: int sock;
1.25 markus 2614: struct sockaddr_un sunaddr;
2615:
2616: if (auth_get_socket_name() != NULL)
2617: fatal("Protocol error: authentication forwarding requested twice.");
2618:
2619: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2620: temporarily_use_uid(pw);
1.25 markus 2621:
2622: /* Allocate a buffer for the socket name, and format the name. */
2623: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2624: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2625: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2626:
2627: /* Create private directory for socket */
1.59 markus 2628: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2629: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2630: strerror(errno));
2631: restore_uid();
2632: xfree(channel_forwarded_auth_socket_name);
2633: xfree(channel_forwarded_auth_socket_dir);
2634: channel_forwarded_auth_socket_name = NULL;
2635: channel_forwarded_auth_socket_dir = NULL;
2636: return 0;
2637: }
1.25 markus 2638: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2639: channel_forwarded_auth_socket_dir, (int) getpid());
2640:
2641: if (atexit(cleanup_socket) < 0) {
2642: int saved = errno;
2643: cleanup_socket();
2644: packet_disconnect("socket: %.100s", strerror(saved));
2645: }
2646: /* Create the socket. */
2647: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2648: if (sock < 0)
2649: packet_disconnect("socket: %.100s", strerror(errno));
2650:
2651: /* Bind it to the name. */
2652: memset(&sunaddr, 0, sizeof(sunaddr));
2653: sunaddr.sun_family = AF_UNIX;
2654: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2655: sizeof(sunaddr.sun_path));
2656:
2657: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2658: packet_disconnect("bind: %.100s", strerror(errno));
2659:
2660: /* Restore the privileged uid. */
2661: restore_uid();
2662:
2663: /* Start listening on the socket. */
2664: if (listen(sock, 5) < 0)
2665: packet_disconnect("listen: %.100s", strerror(errno));
2666:
2667: /* Allocate a channel for the authentication agent socket. */
1.113 markus 2668: nc = channel_new("auth socket",
1.73 markus 2669: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2670: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2671: 0, xstrdup("auth socket"), 1);
1.113 markus 2672: if (nc == NULL) {
2673: error("auth_input_request_forwarding: channel_new failed");
2674: close(sock);
2675: return 0;
2676: }
2677: strlcpy(nc->path, channel_forwarded_auth_socket_name, sizeof(nc->path));
1.59 markus 2678: return 1;
1.1 deraadt 2679: }
2680:
2681: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2682:
1.49 markus 2683: void
1.69 markus 2684: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2685: {
1.113 markus 2686: Channel *c = NULL;
2687: int remote_id, sock;
1.25 markus 2688: char *dummyname;
1.41 markus 2689:
2690: packet_integrity_check(plen, 4, type);
1.25 markus 2691:
2692: /* Read the remote channel number from the message. */
1.113 markus 2693: remote_id = packet_get_int();
1.25 markus 2694:
1.27 markus 2695: /*
2696: * Get a connection to the local authentication agent (this may again
2697: * get forwarded).
2698: */
1.25 markus 2699: sock = ssh_get_authentication_socket();
2700:
1.27 markus 2701: /*
2702: * If we could not connect the agent, send an error message back to
2703: * the server. This should never happen unless the agent dies,
2704: * because authentication forwarding is only enabled if we have an
2705: * agent.
2706: */
1.113 markus 2707: if (sock >= 0) {
2708: dummyname = xstrdup("authentication agent connection");
2709: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1);
2710: if (c == NULL) {
2711: error("auth_input_open_request: channel_new failed");
2712: close(sock);
2713: } else {
2714: c->remote_id = remote_id;
2715: }
2716: }
2717: if (c == NULL) {
1.25 markus 2718: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 2719: packet_put_int(remote_id);
2720: } else {
2721: /* Send a confirmation to the remote host. */
2722: debug("Forwarding authentication connection.");
2723: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2724: packet_put_int(remote_id);
2725: packet_put_int(c->self);
1.25 markus 2726: }
1.44 markus 2727: packet_send();
2728: }
2729:
2730: void
1.51 markus 2731: channel_start_open(int id)
1.44 markus 2732: {
2733: Channel *c = channel_lookup(id);
2734: if (c == NULL) {
2735: log("channel_open: %d: bad id", id);
2736: return;
2737: }
1.51 markus 2738: debug("send channel open %d", id);
1.44 markus 2739: packet_start(SSH2_MSG_CHANNEL_OPEN);
2740: packet_put_cstring(c->ctype);
2741: packet_put_int(c->self);
2742: packet_put_int(c->local_window);
2743: packet_put_int(c->local_maxpacket);
1.51 markus 2744: }
2745: void
2746: channel_open(int id)
2747: {
2748: /* XXX REMOVE ME */
2749: channel_start_open(id);
1.44 markus 2750: packet_send();
2751: }
2752: void
2753: channel_request(int id, char *service, int wantconfirm)
2754: {
2755: channel_request_start(id, service, wantconfirm);
2756: packet_send();
2757: debug("channel request %d: %s", id, service) ;
2758: }
2759: void
2760: channel_request_start(int id, char *service, int wantconfirm)
2761: {
2762: Channel *c = channel_lookup(id);
2763: if (c == NULL) {
2764: log("channel_request: %d: bad id", id);
2765: return;
2766: }
2767: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2768: packet_put_int(c->remote_id);
2769: packet_put_cstring(service);
2770: packet_put_char(wantconfirm);
2771: }
2772: void
2773: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2774: {
2775: Channel *c = channel_lookup(id);
2776: if (c == NULL) {
2777: log("channel_register_callback: %d: bad id", id);
2778: return;
2779: }
2780: c->cb_event = mtype;
2781: c->cb_fn = fn;
2782: c->cb_arg = arg;
2783: }
2784: void
2785: channel_register_cleanup(int id, channel_callback_fn *fn)
2786: {
2787: Channel *c = channel_lookup(id);
2788: if (c == NULL) {
2789: log("channel_register_cleanup: %d: bad id", id);
2790: return;
2791: }
2792: c->dettach_user = fn;
2793: }
2794: void
2795: channel_cancel_cleanup(int id)
2796: {
2797: Channel *c = channel_lookup(id);
2798: if (c == NULL) {
2799: log("channel_cancel_cleanup: %d: bad id", id);
2800: return;
2801: }
2802: c->dettach_user = NULL;
1.65 markus 2803: }
1.89 stevesk 2804: void
1.65 markus 2805: channel_register_filter(int id, channel_filter_fn *fn)
2806: {
2807: Channel *c = channel_lookup(id);
2808: if (c == NULL) {
2809: log("channel_register_filter: %d: bad id", id);
2810: return;
2811: }
2812: c->input_filter = fn;
1.44 markus 2813: }
2814:
2815: void
1.71 markus 2816: channel_set_fds(int id, int rfd, int wfd, int efd,
2817: int extusage, int nonblock)
1.44 markus 2818: {
2819: Channel *c = channel_lookup(id);
2820: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2821: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2822: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2823: c->type = SSH_CHANNEL_OPEN;
2824: /* XXX window size? */
1.68 markus 2825: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2826: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2827: packet_put_int(c->remote_id);
2828: packet_put_int(c->local_window);
1.25 markus 2829: packet_send();
1.1 deraadt 2830: }
![[BACK]](/icons/back.gif){kind=icon}
Return to channels.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh