Annotation of src/usr.bin/ssh/channels.c, Revision 1.113
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"
1.113 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.112 2001/05/04 14:34:34 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: {
845: if (FD_ISSET(c->sock, writeset)) {
846: int err = 0;
847: int sz = sizeof(err);
848: c->type = SSH_CHANNEL_OPEN;
1.89 stevesk 849: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
1.75 markus 850: debug("getsockopt SO_ERROR failed");
851: } else {
852: if (err == 0) {
1.111 stevesk 853: debug("channel %d: connected", c->self);
1.75 markus 854: } else {
855: debug("channel %d: not connected: %s",
856: c->self, strerror(err));
857: chan_read_failed(c);
858: chan_write_failed(c);
859: }
860: }
861: }
862: }
863:
1.41 markus 864: int
865: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
866: {
867: char buf[16*1024];
868: int len;
1.25 markus 869:
1.41 markus 870: if (c->rfd != -1 &&
871: FD_ISSET(c->rfd, readset)) {
872: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 873: if (len < 0 && (errno == EINTR || errno == EAGAIN))
874: return 1;
1.41 markus 875: if (len <= 0) {
1.51 markus 876: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 877: c->self, c->rfd, len);
1.104 markus 878: if (c->type != SSH_CHANNEL_OPEN) {
879: debug("channel %d: not open", c->self);
1.113 ! markus 880: chan_mark_dead(c);
1.103 markus 881: return -1;
1.104 markus 882: } else if (compat13) {
1.41 markus 883: buffer_consume(&c->output, buffer_len(&c->output));
884: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.105 markus 885: debug("channel %d: status set to input draining.", c->self);
1.25 markus 886: } else {
1.41 markus 887: chan_read_failed(c);
1.25 markus 888: }
1.41 markus 889: return -1;
890: }
1.65 markus 891: if(c->input_filter != NULL) {
1.66 markus 892: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 893: debug("channel %d: filter stops", c->self);
1.65 markus 894: chan_read_failed(c);
895: }
896: } else {
897: buffer_append(&c->input, buf, len);
898: }
1.41 markus 899: }
900: return 1;
901: }
902: int
903: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
904: {
1.95 markus 905: struct termios tio;
1.41 markus 906: int len;
1.25 markus 907:
1.41 markus 908: /* Send buffered output data to the socket. */
909: if (c->wfd != -1 &&
910: FD_ISSET(c->wfd, writeset) &&
911: buffer_len(&c->output) > 0) {
912: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 913: buffer_len(&c->output));
914: if (len < 0 && (errno == EINTR || errno == EAGAIN))
915: return 1;
1.41 markus 916: if (len <= 0) {
1.104 markus 917: if (c->type != SSH_CHANNEL_OPEN) {
918: debug("channel %d: not open", c->self);
1.113 ! markus 919: chan_mark_dead(c);
1.104 markus 920: return -1;
921: } else if (compat13) {
1.41 markus 922: buffer_consume(&c->output, buffer_len(&c->output));
1.105 markus 923: debug("channel %d: status set to input draining.", c->self);
1.41 markus 924: c->type = SSH_CHANNEL_INPUT_DRAINING;
925: } else {
926: chan_write_failed(c);
927: }
928: return -1;
1.91 markus 929: }
930: if (compat20 && c->isatty) {
931: if (tcgetattr(c->wfd, &tio) == 0 &&
932: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
933: /*
934: * Simulate echo to reduce the impact of
1.96 markus 935: * traffic analysis. We need to match the
1.95 markus 936: * size of a SSH2_MSG_CHANNEL_DATA message
937: * (4 byte channel id + data)
1.91 markus 938: */
1.95 markus 939: packet_send_ignore(4 + len);
1.91 markus 940: packet_send();
941: }
1.25 markus 942: }
1.41 markus 943: buffer_consume(&c->output, len);
1.44 markus 944: if (compat20 && len > 0) {
945: c->local_consumed += len;
946: }
947: }
948: return 1;
949: }
950: int
951: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
952: {
953: char buf[16*1024];
954: int len;
955:
1.45 markus 956: /** XXX handle drain efd, too */
1.44 markus 957: if (c->efd != -1) {
958: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
959: FD_ISSET(c->efd, writeset) &&
960: buffer_len(&c->extended) > 0) {
961: len = write(c->efd, buffer_ptr(&c->extended),
962: buffer_len(&c->extended));
1.70 markus 963: debug2("channel %d: written %d to efd %d",
1.44 markus 964: c->self, len, c->efd);
1.93 markus 965: if (len < 0 && (errno == EINTR || errno == EAGAIN))
966: return 1;
967: if (len <= 0) {
968: debug2("channel %d: closing write-efd %d",
969: c->self, c->efd);
970: close(c->efd);
971: c->efd = -1;
972: } else {
1.44 markus 973: buffer_consume(&c->extended, len);
974: c->local_consumed += len;
975: }
976: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
977: FD_ISSET(c->efd, readset)) {
978: len = read(c->efd, buf, sizeof(buf));
1.70 markus 979: debug2("channel %d: read %d from efd %d",
1.44 markus 980: c->self, len, c->efd);
1.93 markus 981: if (len < 0 && (errno == EINTR || errno == EAGAIN))
982: return 1;
983: if (len <= 0) {
984: debug2("channel %d: closing read-efd %d",
1.45 markus 985: c->self, c->efd);
986: close(c->efd);
987: c->efd = -1;
1.93 markus 988: } else {
1.44 markus 989: buffer_append(&c->extended, buf, len);
1.93 markus 990: }
1.44 markus 991: }
992: }
993: return 1;
994: }
995: int
1.93 markus 996: channel_check_window(Channel *c)
1.44 markus 997: {
1.104 markus 998: if (c->type == SSH_CHANNEL_OPEN &&
999: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1000: c->local_window < c->local_window_max/2 &&
1001: c->local_consumed > 0) {
1002: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1003: packet_put_int(c->remote_id);
1004: packet_put_int(c->local_consumed);
1005: packet_send();
1.70 markus 1006: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1007: c->self, c->local_window,
1008: c->local_consumed);
1009: c->local_window += c->local_consumed;
1010: c->local_consumed = 0;
1.1 deraadt 1011: }
1.41 markus 1012: return 1;
1.1 deraadt 1013: }
1014:
1.41 markus 1015: void
1016: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1017: {
1018: channel_handle_rfd(c, readset, writeset);
1019: channel_handle_wfd(c, readset, writeset);
1020: }
1.1 deraadt 1021:
1.41 markus 1022: void
1.44 markus 1023: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1024: {
1025: channel_handle_rfd(c, readset, writeset);
1026: channel_handle_wfd(c, readset, writeset);
1027: channel_handle_efd(c, readset, writeset);
1.93 markus 1028:
1029: channel_check_window(c);
1.44 markus 1030: }
1031:
1032: void
1.41 markus 1033: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1034: {
1.41 markus 1035: int len;
1036: /* Send buffered output data to the socket. */
1037: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1038: len = write(c->sock, buffer_ptr(&c->output),
1039: buffer_len(&c->output));
1040: if (len <= 0)
1041: buffer_consume(&c->output, buffer_len(&c->output));
1042: else
1043: buffer_consume(&c->output, len);
1044: }
1045: }
1.25 markus 1046:
1.41 markus 1047: void
1.44 markus 1048: channel_handler_init_20(void)
1049: {
1050: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1051: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1052: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1053: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1054: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1055: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1056: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1057: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1058:
1059: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1060: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1061: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1062: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1063: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1064: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1065: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1066: }
1067:
1068: void
1.41 markus 1069: channel_handler_init_13(void)
1070: {
1071: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1072: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1073: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1074: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1075: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1076: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1077: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1078: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1079: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1080:
1.41 markus 1081: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1082: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1083: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1084: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1085: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1086: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1087: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1088: }
1.25 markus 1089:
1.41 markus 1090: void
1091: channel_handler_init_15(void)
1092: {
1093: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1094: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1095: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1096: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1097: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1098: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1099: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1100:
1.41 markus 1101: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1102: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1103: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1104: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1105: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1106: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1107: }
1.27 markus 1108:
1.41 markus 1109: void
1110: channel_handler_init(void)
1111: {
1112: int i;
1113: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1114: channel_pre[i] = NULL;
1115: channel_post[i] = NULL;
1116: }
1.44 markus 1117: if (compat20)
1118: channel_handler_init_20();
1119: else if (compat13)
1.41 markus 1120: channel_handler_init_13();
1121: else
1122: channel_handler_init_15();
1123: }
1.25 markus 1124:
1.49 markus 1125: void
1.41 markus 1126: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1127: {
1128: static int did_init = 0;
1129: int i;
1130: Channel *c;
1.25 markus 1131:
1.41 markus 1132: if (!did_init) {
1133: channel_handler_init();
1134: did_init = 1;
1135: }
1136: for (i = 0; i < channels_alloc; i++) {
1.113 ! markus 1137: c = channels[i];
! 1138: if (c == NULL)
1.41 markus 1139: continue;
1140: if (ftab[c->type] == NULL)
1.25 markus 1141: continue;
1.41 markus 1142: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1143: if (chan_is_dead(c)) {
1144: /*
1145: * we have to remove the fd's from the select mask
1146: * before the channels are free'd and the fd's are
1147: * closed
1148: */
1149: if (c->wfd != -1)
1150: FD_CLR(c->wfd, writeset);
1151: if (c->rfd != -1)
1152: FD_CLR(c->rfd, readset);
1153: if (c->efd != -1) {
1154: if (c->extended_usage == CHAN_EXTENDED_READ)
1155: FD_CLR(c->efd, readset);
1156: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1157: FD_CLR(c->efd, writeset);
1158: }
1.113 ! markus 1159: channel_free(c);
1.93 markus 1160: }
1.1 deraadt 1161: }
1162: }
1163:
1.49 markus 1164: void
1.100 markus 1165: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1166: int rekeying)
1.41 markus 1167: {
1.84 markus 1168: int n;
1169: u_int sz;
1170:
1171: n = MAX(*maxfdp, channel_max_fd);
1172:
1173: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1174: if (*readsetp == NULL || n > *maxfdp) {
1175: if (*readsetp)
1176: xfree(*readsetp);
1177: if (*writesetp)
1178: xfree(*writesetp);
1179: *readsetp = xmalloc(sz);
1180: *writesetp = xmalloc(sz);
1181: *maxfdp = n;
1182: }
1183: memset(*readsetp, 0, sz);
1184: memset(*writesetp, 0, sz);
1185:
1.100 markus 1186: if (!rekeying)
1187: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1188: }
1189:
1.49 markus 1190: void
1.41 markus 1191: channel_after_select(fd_set * readset, fd_set * writeset)
1192: {
1193: channel_handler(channel_post, readset, writeset);
1194: }
1195:
1.84 markus 1196: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1197:
1.49 markus 1198: void
1.25 markus 1199: channel_output_poll()
1.1 deraadt 1200: {
1.25 markus 1201: int len, i;
1.41 markus 1202: Channel *c;
1.1 deraadt 1203:
1.25 markus 1204: for (i = 0; i < channels_alloc; i++) {
1.113 ! markus 1205:
! 1206: c = channels[i];
! 1207: if (c == NULL)
! 1208: continue;
1.37 markus 1209:
1.27 markus 1210: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1211: if (compat13) {
1.41 markus 1212: if (c->type != SSH_CHANNEL_OPEN &&
1213: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1214: continue;
1215: } else {
1.41 markus 1216: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1217: continue;
1218: }
1.46 markus 1219: if (compat20 &&
1220: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1221: /* XXX is this true? */
1.97 markus 1222: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1223: continue;
1224: }
1.25 markus 1225:
1226: /* Get the amount of buffered data for this channel. */
1.93 markus 1227: if ((c->istate == CHAN_INPUT_OPEN ||
1228: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1229: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1230: /* Send some data for the other side over the secure connection. */
1.44 markus 1231: if (compat20) {
1232: if (len > c->remote_window)
1233: len = c->remote_window;
1234: if (len > c->remote_maxpacket)
1235: len = c->remote_maxpacket;
1.25 markus 1236: } else {
1.44 markus 1237: if (packet_is_interactive()) {
1238: if (len > 1024)
1239: len = 512;
1240: } else {
1241: /* Keep the packets at reasonable size. */
1242: if (len > packet_get_maxsize()/2)
1243: len = packet_get_maxsize()/2;
1244: }
1.25 markus 1245: }
1.41 markus 1246: if (len > 0) {
1.44 markus 1247: packet_start(compat20 ?
1248: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1249: packet_put_int(c->remote_id);
1250: packet_put_string(buffer_ptr(&c->input), len);
1251: packet_send();
1252: buffer_consume(&c->input, len);
1253: c->remote_window -= len;
1254: }
1255: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1256: if (compat13)
1257: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1258: /*
1259: * input-buffer is empty and read-socket shutdown:
1260: * tell peer, that we will not send more data: send IEOF
1261: */
1.41 markus 1262: chan_ibuf_empty(c);
1.25 markus 1263: }
1.44 markus 1264: /* Send extended data, i.e. stderr */
1265: if (compat20 &&
1266: c->remote_window > 0 &&
1267: (len = buffer_len(&c->extended)) > 0 &&
1268: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1269: debug2("channel %d: rwin %d elen %d euse %d",
1270: c->self, c->remote_window, buffer_len(&c->extended),
1271: c->extended_usage);
1.44 markus 1272: if (len > c->remote_window)
1273: len = c->remote_window;
1274: if (len > c->remote_maxpacket)
1275: len = c->remote_maxpacket;
1276: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1277: packet_put_int(c->remote_id);
1278: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1279: packet_put_string(buffer_ptr(&c->extended), len);
1280: packet_send();
1281: buffer_consume(&c->extended, len);
1282: c->remote_window -= len;
1.93 markus 1283: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1284: }
1.25 markus 1285: }
1.1 deraadt 1286: }
1287:
1.27 markus 1288: /*
1289: * This is called when a packet of type CHANNEL_DATA has just been received.
1290: * The message type has already been consumed, but channel number and data is
1291: * still there.
1292: */
1.1 deraadt 1293:
1.49 markus 1294: void
1.69 markus 1295: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1296: {
1.37 markus 1297: int id;
1.25 markus 1298: char *data;
1.77 markus 1299: u_int data_len;
1.41 markus 1300: Channel *c;
1.25 markus 1301:
1302: /* Get the channel number and verify it. */
1.37 markus 1303: id = packet_get_int();
1.41 markus 1304: c = channel_lookup(id);
1305: if (c == NULL)
1.37 markus 1306: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1307:
1308: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1309: if (c->type != SSH_CHANNEL_OPEN &&
1310: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1311: return;
1312:
1313: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1314: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1315: return;
1316:
1317: /* Get the data. */
1318: data = packet_get_string(&data_len);
1.48 markus 1319: packet_done();
1.41 markus 1320:
1.44 markus 1321: if (compat20){
1322: if (data_len > c->local_maxpacket) {
1323: log("channel %d: rcvd big packet %d, maxpack %d",
1324: c->self, data_len, c->local_maxpacket);
1325: }
1326: if (data_len > c->local_window) {
1327: log("channel %d: rcvd too much data %d, win %d",
1328: c->self, data_len, c->local_window);
1329: xfree(data);
1330: return;
1331: }
1332: c->local_window -= data_len;
1333: }else{
1334: packet_integrity_check(plen, 4 + 4 + data_len, type);
1335: }
1.41 markus 1336: buffer_append(&c->output, data, data_len);
1.25 markus 1337: xfree(data);
1.1 deraadt 1338: }
1.49 markus 1339: void
1.69 markus 1340: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1341: {
1342: int id;
1343: int tcode;
1344: char *data;
1.77 markus 1345: u_int data_len;
1.44 markus 1346: Channel *c;
1347:
1348: /* Get the channel number and verify it. */
1349: id = packet_get_int();
1350: c = channel_lookup(id);
1351:
1352: if (c == NULL)
1353: packet_disconnect("Received extended_data for bad channel %d.", id);
1354: if (c->type != SSH_CHANNEL_OPEN) {
1355: log("channel %d: ext data for non open", id);
1356: return;
1357: }
1358: tcode = packet_get_int();
1359: if (c->efd == -1 ||
1360: c->extended_usage != CHAN_EXTENDED_WRITE ||
1361: tcode != SSH2_EXTENDED_DATA_STDERR) {
1362: log("channel %d: bad ext data", c->self);
1363: return;
1364: }
1365: data = packet_get_string(&data_len);
1.48 markus 1366: packet_done();
1.44 markus 1367: if (data_len > c->local_window) {
1368: log("channel %d: rcvd too much extended_data %d, win %d",
1369: c->self, data_len, c->local_window);
1370: xfree(data);
1371: return;
1372: }
1.70 markus 1373: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1374: c->local_window -= data_len;
1375: buffer_append(&c->extended, data, data_len);
1376: xfree(data);
1377: }
1378:
1.1 deraadt 1379:
1.27 markus 1380: /*
1381: * Returns true if no channel has too much buffered data, and false if one or
1382: * more channel is overfull.
1383: */
1.1 deraadt 1384:
1.49 markus 1385: int
1.25 markus 1386: channel_not_very_much_buffered_data()
1.1 deraadt 1387: {
1.77 markus 1388: u_int i;
1.41 markus 1389: Channel *c;
1.25 markus 1390:
1391: for (i = 0; i < channels_alloc; i++) {
1.113 ! markus 1392: c = channels[i];
! 1393: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1394: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1395: debug("channel %d: big input buffer %d",
1396: c->self, buffer_len(&c->input));
1.25 markus 1397: return 0;
1.41 markus 1398: }
1399: if (buffer_len(&c->output) > packet_get_maxsize()) {
1400: debug("channel %d: big output buffer %d",
1401: c->self, buffer_len(&c->output));
1.25 markus 1402: return 0;
1.41 markus 1403: }
1.25 markus 1404: }
1.1 deraadt 1405: }
1.25 markus 1406: return 1;
1.1 deraadt 1407: }
1408:
1.49 markus 1409: void
1.69 markus 1410: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1411: {
1412: int id;
1413: Channel *c;
1414:
1415: packet_integrity_check(plen, 4, type);
1416:
1417: id = packet_get_int();
1418: c = channel_lookup(id);
1419: if (c == NULL)
1420: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1421: chan_rcvd_ieof(c);
1422: }
1.1 deraadt 1423:
1.49 markus 1424: void
1.69 markus 1425: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1426: {
1.41 markus 1427: int id;
1428: Channel *c;
1.1 deraadt 1429:
1.41 markus 1430: packet_integrity_check(plen, 4, type);
1431:
1432: id = packet_get_int();
1433: c = channel_lookup(id);
1434: if (c == NULL)
1435: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1436:
1437: /*
1438: * Send a confirmation that we have closed the channel and no more
1439: * data is coming for it.
1440: */
1.25 markus 1441: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1442: packet_put_int(c->remote_id);
1.25 markus 1443: packet_send();
1444:
1.27 markus 1445: /*
1446: * If the channel is in closed state, we have sent a close request,
1447: * and the other side will eventually respond with a confirmation.
1448: * Thus, we cannot free the channel here, because then there would be
1449: * no-one to receive the confirmation. The channel gets freed when
1450: * the confirmation arrives.
1451: */
1.41 markus 1452: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1453: /*
1454: * Not a closed channel - mark it as draining, which will
1455: * cause it to be freed later.
1456: */
1.41 markus 1457: buffer_consume(&c->input, buffer_len(&c->input));
1458: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1459: }
1.1 deraadt 1460: }
1461:
1.41 markus 1462: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1463: void
1.69 markus 1464: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1465: {
1466: int id = packet_get_int();
1467: Channel *c = channel_lookup(id);
1468: packet_integrity_check(plen, 4, type);
1469: if (c == NULL)
1470: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1471: chan_rcvd_oclose(c);
1472: }
1.1 deraadt 1473:
1.49 markus 1474: void
1.69 markus 1475: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1476: {
1.41 markus 1477: int id = packet_get_int();
1478: Channel *c = channel_lookup(id);
1.1 deraadt 1479:
1.48 markus 1480: packet_done();
1.41 markus 1481: if (c == NULL)
1482: packet_disconnect("Received close confirmation for "
1483: "out-of-range channel %d.", id);
1484: if (c->type != SSH_CHANNEL_CLOSED)
1485: packet_disconnect("Received close confirmation for "
1486: "non-closed channel %d (type %d).", id, c->type);
1.113 ! markus 1487: channel_free(c);
1.1 deraadt 1488: }
1489:
1.49 markus 1490: void
1.69 markus 1491: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1492: {
1.41 markus 1493: int id, remote_id;
1494: Channel *c;
1.1 deraadt 1495:
1.44 markus 1496: if (!compat20)
1497: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1498:
1.41 markus 1499: id = packet_get_int();
1500: c = channel_lookup(id);
1.25 markus 1501:
1.41 markus 1502: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1503: packet_disconnect("Received open confirmation for "
1504: "non-opening channel %d.", id);
1505: remote_id = packet_get_int();
1.27 markus 1506: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1507: c->remote_id = remote_id;
1508: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1509:
1510: if (compat20) {
1511: c->remote_window = packet_get_int();
1512: c->remote_maxpacket = packet_get_int();
1.48 markus 1513: packet_done();
1.44 markus 1514: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1515: debug2("callback start");
1.44 markus 1516: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1517: debug2("callback done");
1.44 markus 1518: }
1519: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1520: c->remote_window, c->remote_maxpacket);
1521: }
1.1 deraadt 1522: }
1523:
1.49 markus 1524: void
1.69 markus 1525: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1526: {
1.86 markus 1527: int id, reason;
1528: char *msg = NULL, *lang = NULL;
1.41 markus 1529: Channel *c;
1530:
1.44 markus 1531: if (!compat20)
1532: packet_integrity_check(plen, 4, type);
1.41 markus 1533:
1534: id = packet_get_int();
1535: c = channel_lookup(id);
1.25 markus 1536:
1.41 markus 1537: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1538: packet_disconnect("Received open failure for "
1539: "non-opening channel %d.", id);
1.44 markus 1540: if (compat20) {
1.86 markus 1541: reason = packet_get_int();
1.110 markus 1542: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 1543: msg = packet_get_string(NULL);
1544: lang = packet_get_string(NULL);
1545: }
1.48 markus 1546: packet_done();
1.86 markus 1547: log("channel_open_failure: %d: reason %d %s", id,
1548: reason, msg ? msg : "<no additional info>");
1549: if (msg != NULL)
1550: xfree(msg);
1551: if (lang != NULL)
1552: xfree(lang);
1.44 markus 1553: }
1.25 markus 1554: /* Free the channel. This will also close the socket. */
1.113 ! markus 1555: channel_free(c);
1.1 deraadt 1556: }
1557:
1.44 markus 1558: void
1.69 markus 1559: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1560: {
1561: int id;
1562: Channel *c;
1563:
1564: id = packet_get_int();
1565: c = channel_lookup(id);
1566:
1567: if (c == NULL ||
1568: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1569: packet_disconnect("Received request for "
1570: "non-open channel %d.", id);
1571: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1572: debug2("callback start");
1.44 markus 1573: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1574: debug2("callback done");
1.44 markus 1575: } else {
1576: char *service = packet_get_string(NULL);
1.94 markus 1577: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1578: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1579: xfree(service);
1580: }
1581: }
1582:
1.49 markus 1583: void
1.69 markus 1584: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1585: {
1586: Channel *c;
1587: int id, adjust;
1588:
1589: if (!compat20)
1590: return;
1591:
1592: /* Get the channel number and verify it. */
1593: id = packet_get_int();
1594: c = channel_lookup(id);
1595:
1596: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1597: log("Received window adjust for "
1598: "non-open channel %d.", id);
1599: return;
1600: }
1601: adjust = packet_get_int();
1.48 markus 1602: packet_done();
1.70 markus 1603: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1604: c->remote_window += adjust;
1605: }
1606:
1.27 markus 1607: /*
1608: * Stops listening for channels, and removes any unix domain sockets that we
1609: * might have.
1610: */
1.1 deraadt 1611:
1.49 markus 1612: void
1.25 markus 1613: channel_stop_listening()
1.1 deraadt 1614: {
1.25 markus 1615: int i;
1.113 ! markus 1616: Channel *c;
! 1617:
1.25 markus 1618: for (i = 0; i < channels_alloc; i++) {
1.113 ! markus 1619: c = channels[i];
! 1620: if (c != NULL) {
! 1621: switch (c->type) {
! 1622: case SSH_CHANNEL_AUTH_SOCKET:
! 1623: close(c->sock);
! 1624: unlink(c->path);
! 1625: channel_free(c);
! 1626: break;
! 1627: case SSH_CHANNEL_PORT_LISTENER:
! 1628: case SSH_CHANNEL_RPORT_LISTENER:
! 1629: case SSH_CHANNEL_X11_LISTENER:
! 1630: close(c->sock);
! 1631: channel_free(c);
! 1632: break;
! 1633: default:
! 1634: break;
! 1635: }
1.25 markus 1636: }
1.1 deraadt 1637: }
1638: }
1639:
1.27 markus 1640: /*
1.52 markus 1641: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1642: * descriptors after a fork.
1643: */
1.1 deraadt 1644:
1.49 markus 1645: void
1.25 markus 1646: channel_close_all()
1.1 deraadt 1647: {
1.25 markus 1648: int i;
1.113 ! markus 1649:
1.52 markus 1650: for (i = 0; i < channels_alloc; i++)
1.113 ! markus 1651: if (channels[i] != NULL)
! 1652: channel_close_fds(channels[i]);
1.1 deraadt 1653: }
1654:
1655: /* Returns true if any channel is still open. */
1656:
1.49 markus 1657: int
1.25 markus 1658: channel_still_open()
1.1 deraadt 1659: {
1.113 ! markus 1660: int i;
! 1661: Channel *c;
! 1662:
! 1663: for (i = 0; i < channels_alloc; i++) {
! 1664: c = channels[i];
! 1665: if (c == NULL)
! 1666: continue;
! 1667: switch (c->type) {
1.25 markus 1668: case SSH_CHANNEL_X11_LISTENER:
1669: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1670: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1671: case SSH_CHANNEL_CLOSED:
1672: case SSH_CHANNEL_AUTH_SOCKET:
1.103 markus 1673: case SSH_CHANNEL_DYNAMIC:
1.75 markus 1674: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1675: continue;
1.44 markus 1676: case SSH_CHANNEL_LARVAL:
1677: if (!compat20)
1678: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1679: continue;
1.25 markus 1680: case SSH_CHANNEL_OPENING:
1681: case SSH_CHANNEL_OPEN:
1682: case SSH_CHANNEL_X11_OPEN:
1683: return 1;
1684: case SSH_CHANNEL_INPUT_DRAINING:
1685: case SSH_CHANNEL_OUTPUT_DRAINING:
1686: if (!compat13)
1687: fatal("cannot happen: OUT_DRAIN");
1688: return 1;
1689: default:
1.113 ! markus 1690: fatal("channel_still_open: bad channel type %d", c->type);
1.25 markus 1691: /* NOTREACHED */
1692: }
1.113 ! markus 1693: }
1.25 markus 1694: return 0;
1.1 deraadt 1695: }
1.107 beck 1696:
1697: /* Returns the id of an open channel suitable for keepaliving */
1698:
1699: int
1700: channel_find_open()
1701: {
1.113 ! markus 1702: int i;
! 1703: Channel *c;
! 1704:
! 1705: for (i = 0; i < channels_alloc; i++) {
! 1706: c = channels[i];
! 1707: if (c == NULL)
! 1708: continue;
! 1709: switch (c->type) {
1.107 beck 1710: case SSH_CHANNEL_CLOSED:
1711: case SSH_CHANNEL_DYNAMIC:
1712: case SSH_CHANNEL_X11_LISTENER:
1713: case SSH_CHANNEL_PORT_LISTENER:
1714: case SSH_CHANNEL_RPORT_LISTENER:
1715: case SSH_CHANNEL_OPENING:
1.108 markus 1716: continue;
1717: case SSH_CHANNEL_LARVAL:
1718: case SSH_CHANNEL_AUTH_SOCKET:
1719: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.107 beck 1720: case SSH_CHANNEL_OPEN:
1721: case SSH_CHANNEL_X11_OPEN:
1722: return i;
1723: case SSH_CHANNEL_INPUT_DRAINING:
1724: case SSH_CHANNEL_OUTPUT_DRAINING:
1725: if (!compat13)
1726: fatal("cannot happen: OUT_DRAIN");
1727: return i;
1728: default:
1.113 ! markus 1729: fatal("channel_find_open: bad channel type %d", c->type);
1.107 beck 1730: /* NOTREACHED */
1731: }
1.113 ! markus 1732: }
1.107 beck 1733: return -1;
1734: }
1735:
1.1 deraadt 1736:
1.27 markus 1737: /*
1738: * Returns a message describing the currently open forwarded connections,
1739: * suitable for sending to the client. The message contains crlf pairs for
1740: * newlines.
1741: */
1.1 deraadt 1742:
1.25 markus 1743: char *
1744: channel_open_message()
1.1 deraadt 1745: {
1.25 markus 1746: Buffer buffer;
1.113 ! markus 1747: Channel *c;
! 1748: char buf[1024], *cp;
1.25 markus 1749: int i;
1750:
1751: buffer_init(&buffer);
1752: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1753: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1754: for (i = 0; i < channels_alloc; i++) {
1.113 ! markus 1755: c = channels[i];
! 1756: if (c == NULL)
! 1757: continue;
1.25 markus 1758: switch (c->type) {
1759: case SSH_CHANNEL_X11_LISTENER:
1760: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1761: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1762: case SSH_CHANNEL_CLOSED:
1763: case SSH_CHANNEL_AUTH_SOCKET:
1764: continue;
1.44 markus 1765: case SSH_CHANNEL_LARVAL:
1.25 markus 1766: case SSH_CHANNEL_OPENING:
1.75 markus 1767: case SSH_CHANNEL_CONNECTING:
1.103 markus 1768: case SSH_CHANNEL_DYNAMIC:
1.25 markus 1769: case SSH_CHANNEL_OPEN:
1770: case SSH_CHANNEL_X11_OPEN:
1771: case SSH_CHANNEL_INPUT_DRAINING:
1772: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1773: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1774: c->self, c->remote_name,
1775: c->type, c->remote_id,
1776: c->istate, buffer_len(&c->input),
1.41 markus 1777: c->ostate, buffer_len(&c->output),
1778: c->rfd, c->wfd);
1.25 markus 1779: buffer_append(&buffer, buf, strlen(buf));
1780: continue;
1781: default:
1.41 markus 1782: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1783: /* NOTREACHED */
1784: }
1785: }
1786: buffer_append(&buffer, "\0", 1);
1787: cp = xstrdup(buffer_ptr(&buffer));
1788: buffer_free(&buffer);
1789: return cp;
1.1 deraadt 1790: }
1791:
1.27 markus 1792: /*
1793: * Initiate forwarding of connections to local port "port" through the secure
1794: * channel to host:port from remote side.
1795: */
1.87 markus 1796: int
1.73 markus 1797: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1798: u_short port_to_connect, int gateway_ports)
1799: {
1.87 markus 1800: return channel_request_forwarding(
1.73 markus 1801: NULL, listen_port,
1802: host_to_connect, port_to_connect,
1803: gateway_ports, /*remote_fwd*/ 0);
1804: }
1.1 deraadt 1805:
1.73 markus 1806: /*
1807: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1808: * (SSH_CHANNEL_RPORT_LISTENER).
1809: */
1.87 markus 1810: int
1.73 markus 1811: channel_request_forwarding(
1812: const char *listen_address, u_short listen_port,
1813: const char *host_to_connect, u_short port_to_connect,
1814: int gateway_ports, int remote_fwd)
1.25 markus 1815: {
1.113 ! markus 1816: Channel *c;
! 1817: int success, sock, on = 1, ctype;
1.35 markus 1818: struct addrinfo hints, *ai, *aitop;
1819: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1820: const char *host;
1.28 markus 1821: struct linger linger;
1.25 markus 1822:
1.87 markus 1823: success = 0;
1824:
1.73 markus 1825: if (remote_fwd) {
1826: host = listen_address;
1.89 stevesk 1827: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1828: } else {
1829: host = host_to_connect;
1830: ctype =SSH_CHANNEL_PORT_LISTENER;
1831: }
1832:
1.113 ! markus 1833: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.87 markus 1834: error("Forward host name too long.");
1835: return success;
1836: }
1.25 markus 1837:
1.73 markus 1838: /* XXX listen_address is currently ignored */
1.28 markus 1839: /*
1.35 markus 1840: * getaddrinfo returns a loopback address if the hostname is
1841: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1842: */
1.35 markus 1843: memset(&hints, 0, sizeof(hints));
1844: hints.ai_family = IPv4or6;
1845: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1846: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1847: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1848: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1849: packet_disconnect("getaddrinfo: fatal error");
1850:
1851: for (ai = aitop; ai; ai = ai->ai_next) {
1852: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1853: continue;
1854: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1855: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1856: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1857: continue;
1858: }
1859: /* Create a port to listen for the host. */
1860: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1861: if (sock < 0) {
1862: /* this is no error since kernel may not support ipv6 */
1863: verbose("socket: %.100s", strerror(errno));
1864: continue;
1865: }
1866: /*
1867: * Set socket options. We would like the socket to disappear
1868: * as soon as it has been closed for whatever reason.
1869: */
1870: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1871: linger.l_onoff = 1;
1872: linger.l_linger = 5;
1873: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1874: debug("Local forwarding listening on %s port %s.", ntop, strport);
1875:
1876: /* Bind the socket to the address. */
1877: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1878: /* address can be in use ipv6 address is already bound */
1879: verbose("bind: %.100s", strerror(errno));
1880: close(sock);
1881: continue;
1882: }
1883: /* Start listening for connections on the socket. */
1884: if (listen(sock, 5) < 0) {
1885: error("listen: %.100s", strerror(errno));
1886: close(sock);
1887: continue;
1888: }
1889: /* Allocate a channel number for the socket. */
1.113 ! markus 1890: c = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1891: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1892: 0, xstrdup("port listener"), 1);
1.113 ! markus 1893: if (c == NULL) {
! 1894: error("channel_request_forwarding: channel_new failed");
! 1895: close(sock);
! 1896: continue;
! 1897: }
! 1898: strlcpy(c->path, host, sizeof(c->path));
! 1899: c->host_port = port_to_connect;
! 1900: c->listening_port = listen_port;
1.35 markus 1901: success = 1;
1902: }
1903: if (success == 0)
1.87 markus 1904: error("channel_request_forwarding: cannot listen to port: %d",
1905: listen_port);
1.35 markus 1906: freeaddrinfo(aitop);
1.87 markus 1907: return success;
1.25 markus 1908: }
1.1 deraadt 1909:
1.27 markus 1910: /*
1911: * Initiate forwarding of connections to port "port" on remote host through
1912: * the secure channel to host:port from local side.
1913: */
1.1 deraadt 1914:
1.49 markus 1915: void
1.73 markus 1916: channel_request_remote_forwarding(u_short listen_port,
1917: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1918: {
1.73 markus 1919: int payload_len, type, success = 0;
1920:
1.25 markus 1921: /* Record locally that connection to this host/port is permitted. */
1922: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1923: fatal("channel_request_remote_forwarding: too many forwards");
1924:
1925: /* Send the forward request to the remote side. */
1.44 markus 1926: if (compat20) {
1927: const char *address_to_bind = "0.0.0.0";
1928: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1929: packet_put_cstring("tcpip-forward");
1930: packet_put_char(0); /* boolean: want reply */
1931: packet_put_cstring(address_to_bind);
1932: packet_put_int(listen_port);
1.73 markus 1933: packet_send();
1934: packet_write_wait();
1935: /* Assume that server accepts the request */
1936: success = 1;
1.44 markus 1937: } else {
1938: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1939: packet_put_int(listen_port);
1940: packet_put_cstring(host_to_connect);
1.44 markus 1941: packet_put_int(port_to_connect);
1942: packet_send();
1943: packet_write_wait();
1.73 markus 1944:
1945: /* Wait for response from the remote side. */
1946: type = packet_read(&payload_len);
1947: switch (type) {
1948: case SSH_SMSG_SUCCESS:
1949: success = 1;
1950: break;
1951: case SSH_SMSG_FAILURE:
1952: log("Warning: Server denied remote port forwarding.");
1953: break;
1954: default:
1955: /* Unknown packet */
1956: packet_disconnect("Protocol error for port forward request:"
1957: "received packet type %d.", type);
1958: }
1959: }
1960: if (success) {
1961: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1962: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1963: permitted_opens[num_permitted_opens].listen_port = listen_port;
1964: num_permitted_opens++;
1.44 markus 1965: }
1.1 deraadt 1966: }
1967:
1.27 markus 1968: /*
1969: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1970: * listening for the port, and sends back a success reply (or disconnect
1971: * message if there was an error). This never returns if there was an error.
1972: */
1.1 deraadt 1973:
1.49 markus 1974: void
1.56 markus 1975: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1976: {
1.31 markus 1977: u_short port, host_port;
1.25 markus 1978: char *hostname;
1.1 deraadt 1979:
1.25 markus 1980: /* Get arguments from the packet. */
1981: port = packet_get_int();
1982: hostname = packet_get_string(NULL);
1983: host_port = packet_get_int();
1984:
1.27 markus 1985: /*
1986: * Check that an unprivileged user is not trying to forward a
1987: * privileged port.
1988: */
1.25 markus 1989: if (port < IPPORT_RESERVED && !is_root)
1990: packet_disconnect("Requested forwarding of port %d but user is not root.",
1991: port);
1.73 markus 1992: /* Initiate forwarding */
1.56 markus 1993: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1994:
1995: /* Free the argument string. */
1996: xfree(hostname);
1.1 deraadt 1997: }
1998:
1.99 markus 1999: /*
2000: * Permits opening to any host/port if permitted_opens[] is empty. This is
2001: * usually called by the server, because the user could connect to any port
2002: * anyway, and the server has no way to know but to trust the client anyway.
2003: */
2004: void
2005: channel_permit_all_opens()
2006: {
2007: if (num_permitted_opens == 0)
2008: all_opens_permitted = 1;
2009: }
2010:
1.101 markus 2011: void
1.99 markus 2012: channel_add_permitted_opens(char *host, int port)
2013: {
2014: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2015: fatal("channel_request_remote_forwarding: too many forwards");
2016: debug("allow port forwarding to host %s port %d", host, port);
2017:
2018: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2019: permitted_opens[num_permitted_opens].port_to_connect = port;
2020: num_permitted_opens++;
2021:
2022: all_opens_permitted = 0;
2023: }
2024:
1.101 markus 2025: void
1.99 markus 2026: channel_clear_permitted_opens(void)
2027: {
2028: int i;
2029:
2030: for (i = 0; i < num_permitted_opens; i++)
2031: xfree(permitted_opens[i].host_to_connect);
2032: num_permitted_opens = 0;
2033:
2034: }
2035:
2036:
2037: /* return socket to remote host, port */
1.41 markus 2038: int
1.99 markus 2039: connect_to(const char *host, u_short port)
1.41 markus 2040: {
2041: struct addrinfo hints, *ai, *aitop;
2042: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2043: int gaierr;
2044: int sock = -1;
2045:
2046: memset(&hints, 0, sizeof(hints));
2047: hints.ai_family = IPv4or6;
2048: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2049: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2050: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2051: error("connect_to %.100s: unknown host (%s)", host,
2052: gai_strerror(gaierr));
1.41 markus 2053: return -1;
2054: }
2055: for (ai = aitop; ai; ai = ai->ai_next) {
2056: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2057: continue;
2058: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2059: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2060: error("connect_to: getnameinfo failed");
1.41 markus 2061: continue;
2062: }
2063: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2064: if (sock < 0) {
2065: error("socket: %.100s", strerror(errno));
2066: continue;
2067: }
1.80 markus 2068: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2069: fatal("connect_to: F_SETFL: %s", strerror(errno));
2070: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2071: errno != EINPROGRESS) {
1.99 markus 2072: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2073: strerror(errno));
2074: close(sock);
1.89 stevesk 2075: continue; /* fail -- try next */
1.41 markus 2076: }
2077: break; /* success */
2078:
2079: }
2080: freeaddrinfo(aitop);
2081: if (!ai) {
1.99 markus 2082: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2083: return -1;
2084: }
2085: /* success */
2086: return sock;
2087: }
1.99 markus 2088:
1.73 markus 2089: int
2090: channel_connect_by_listen_adress(u_short listen_port)
2091: {
2092: int i;
1.99 markus 2093:
1.73 markus 2094: for (i = 0; i < num_permitted_opens; i++)
2095: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2096: return connect_to(
1.73 markus 2097: permitted_opens[i].host_to_connect,
2098: permitted_opens[i].port_to_connect);
1.74 markus 2099: error("WARNING: Server requests forwarding for unknown listen_port %d",
2100: listen_port);
1.73 markus 2101: return -1;
2102: }
2103:
1.99 markus 2104: /* Check if connecting to that port is permitted and connect. */
2105: int
2106: channel_connect_to(const char *host, u_short port)
2107: {
2108: int i, permit;
2109:
2110: permit = all_opens_permitted;
2111: if (!permit) {
2112: for (i = 0; i < num_permitted_opens; i++)
2113: if (permitted_opens[i].port_to_connect == port &&
2114: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2115: permit = 1;
2116:
2117: }
2118: if (!permit) {
2119: log("Received request to connect to host %.100s port %d, "
2120: "but the request was denied.", host, port);
2121: return -1;
2122: }
2123: return connect_to(host, port);
2124: }
2125:
1.27 markus 2126: /*
2127: * This is called after receiving PORT_OPEN message. This attempts to
2128: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2129: * or CHANNEL_OPEN_FAILURE.
2130: */
1.1 deraadt 2131:
1.49 markus 2132: void
1.69 markus 2133: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2134: {
1.113 ! markus 2135: Channel *c = NULL;
1.31 markus 2136: u_short host_port;
1.25 markus 2137: char *host, *originator_string;
1.113 ! markus 2138: int remote_id, sock = -1;
1.25 markus 2139:
1.113 ! markus 2140: remote_id = packet_get_int();
1.99 markus 2141: host = packet_get_string(NULL);
1.25 markus 2142: host_port = packet_get_int();
2143:
1.29 markus 2144: if (have_hostname_in_open) {
1.99 markus 2145: originator_string = packet_get_string(NULL);
1.29 markus 2146: } else {
1.25 markus 2147: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 2148: }
1.99 markus 2149: packet_done();
2150: sock = channel_connect_to(host, host_port);
2151: if (sock != -1) {
1.113 ! markus 2152: c = channel_new("connected socket",
! 2153: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
! 2154: originator_string, 1);
! 2155: if (c == NULL) {
! 2156: error("channel_input_port_open: channel_new failed");
! 2157: close(sock);
! 2158: } else {
! 2159: c->remote_id = remote_id;
! 2160: }
! 2161: }
! 2162: if (c == NULL) {
! 2163: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
! 2164: packet_put_int(remote_id);
! 2165: } else {
1.99 markus 2166: /*XXX delay answer? */
1.41 markus 2167: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 ! markus 2168: packet_put_int(remote_id);
! 2169: packet_put_int(c->self);
1.25 markus 2170: }
1.113 ! markus 2171: packet_send();
1.25 markus 2172: xfree(host);
1.1 deraadt 2173: }
2174:
1.27 markus 2175: /*
2176: * Creates an internet domain socket for listening for X11 connections.
2177: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2178: * occurs.
2179: */
1.1 deraadt 2180:
1.35 markus 2181: #define NUM_SOCKS 10
2182:
1.25 markus 2183: char *
1.33 markus 2184: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2185: {
1.31 markus 2186: int display_number, sock;
2187: u_short port;
1.35 markus 2188: struct addrinfo hints, *ai, *aitop;
2189: char strport[NI_MAXSERV];
2190: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2191: char display[512];
1.25 markus 2192: char hostname[MAXHOSTNAMELEN];
2193:
1.33 markus 2194: for (display_number = x11_display_offset;
1.25 markus 2195: display_number < MAX_DISPLAYS;
2196: display_number++) {
2197: port = 6000 + display_number;
1.35 markus 2198: memset(&hints, 0, sizeof(hints));
2199: hints.ai_family = IPv4or6;
1.36 markus 2200: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2201: hints.ai_socktype = SOCK_STREAM;
2202: snprintf(strport, sizeof strport, "%d", port);
2203: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2204: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2205: return NULL;
2206: }
1.35 markus 2207: for (ai = aitop; ai; ai = ai->ai_next) {
2208: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2209: continue;
2210: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2211: if (sock < 0) {
2212: error("socket: %.100s", strerror(errno));
2213: return NULL;
2214: }
2215: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2216: debug("bind port %d: %.100s", port, strerror(errno));
2217: shutdown(sock, SHUT_RDWR);
2218: close(sock);
2219: for (n = 0; n < num_socks; n++) {
2220: shutdown(socks[n], SHUT_RDWR);
2221: close(socks[n]);
2222: }
2223: num_socks = 0;
2224: break;
2225: }
2226: socks[num_socks++] = sock;
2227: if (num_socks == NUM_SOCKS)
2228: break;
1.25 markus 2229: }
1.83 stevesk 2230: freeaddrinfo(aitop);
1.35 markus 2231: if (num_socks > 0)
2232: break;
1.25 markus 2233: }
2234: if (display_number >= MAX_DISPLAYS) {
2235: error("Failed to allocate internet-domain X11 display socket.");
2236: return NULL;
2237: }
2238: /* Start listening for connections on the socket. */
1.35 markus 2239: for (n = 0; n < num_socks; n++) {
2240: sock = socks[n];
2241: if (listen(sock, 5) < 0) {
2242: error("listen: %.100s", strerror(errno));
2243: shutdown(sock, SHUT_RDWR);
2244: close(sock);
2245: return NULL;
2246: }
1.25 markus 2247: }
1.35 markus 2248:
1.25 markus 2249: /* Set up a suitable value for the DISPLAY variable. */
2250: if (gethostname(hostname, sizeof(hostname)) < 0)
2251: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2252: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2253: display_number, screen_number);
2254:
1.35 markus 2255: /* Allocate a channel for each socket. */
2256: for (n = 0; n < num_socks; n++) {
2257: sock = socks[n];
1.51 markus 2258: (void) channel_new("x11 listener",
2259: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2260: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2261: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2262: }
1.1 deraadt 2263:
1.25 markus 2264: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2265: return xstrdup(display);
1.1 deraadt 2266: }
2267:
2268: #ifndef X_UNIX_PATH
2269: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2270: #endif
2271:
2272: static
2273: int
1.77 markus 2274: connect_local_xsocket(u_int dnr)
1.1 deraadt 2275: {
1.25 markus 2276: static const char *const x_sockets[] = {
2277: X_UNIX_PATH "%u",
2278: "/var/X/.X11-unix/X" "%u",
2279: "/usr/spool/sockets/X11/" "%u",
2280: NULL
2281: };
2282: int sock;
2283: struct sockaddr_un addr;
2284: const char *const * path;
2285:
2286: for (path = x_sockets; *path; ++path) {
2287: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2288: if (sock < 0)
2289: error("socket: %.100s", strerror(errno));
2290: memset(&addr, 0, sizeof(addr));
2291: addr.sun_family = AF_UNIX;
2292: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2293: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2294: return sock;
2295: close(sock);
2296: }
2297: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2298: return -1;
1.1 deraadt 2299: }
2300:
1.51 markus 2301: int
2302: x11_connect_display(void)
1.1 deraadt 2303: {
1.51 markus 2304: int display_number, sock = 0;
1.25 markus 2305: const char *display;
1.51 markus 2306: char buf[1024], *cp;
1.35 markus 2307: struct addrinfo hints, *ai, *aitop;
2308: char strport[NI_MAXSERV];
2309: int gaierr;
1.25 markus 2310:
2311: /* Try to open a socket for the local X server. */
2312: display = getenv("DISPLAY");
2313: if (!display) {
2314: error("DISPLAY not set.");
1.51 markus 2315: return -1;
1.25 markus 2316: }
1.27 markus 2317: /*
2318: * Now we decode the value of the DISPLAY variable and make a
2319: * connection to the real X server.
2320: */
2321:
2322: /*
2323: * Check if it is a unix domain socket. Unix domain displays are in
2324: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2325: */
1.25 markus 2326: if (strncmp(display, "unix:", 5) == 0 ||
2327: display[0] == ':') {
2328: /* Connect to the unix domain socket. */
2329: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2330: error("Could not parse display number from DISPLAY: %.100s",
2331: display);
1.51 markus 2332: return -1;
1.25 markus 2333: }
2334: /* Create a socket. */
2335: sock = connect_local_xsocket(display_number);
2336: if (sock < 0)
1.51 markus 2337: return -1;
1.25 markus 2338:
2339: /* OK, we now have a connection to the display. */
1.51 markus 2340: return sock;
1.25 markus 2341: }
1.27 markus 2342: /*
2343: * Connect to an inet socket. The DISPLAY value is supposedly
2344: * hostname:d[.s], where hostname may also be numeric IP address.
2345: */
1.25 markus 2346: strncpy(buf, display, sizeof(buf));
2347: buf[sizeof(buf) - 1] = 0;
2348: cp = strchr(buf, ':');
2349: if (!cp) {
2350: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2351: return -1;
1.25 markus 2352: }
2353: *cp = 0;
1.27 markus 2354: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2355: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2356: error("Could not parse display number from DISPLAY: %.100s",
2357: display);
1.51 markus 2358: return -1;
1.25 markus 2359: }
1.35 markus 2360:
2361: /* Look up the host address */
2362: memset(&hints, 0, sizeof(hints));
2363: hints.ai_family = IPv4or6;
2364: hints.ai_socktype = SOCK_STREAM;
2365: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2366: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2367: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2368: return -1;
1.25 markus 2369: }
1.35 markus 2370: for (ai = aitop; ai; ai = ai->ai_next) {
2371: /* Create a socket. */
2372: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2373: if (sock < 0) {
2374: debug("socket: %.100s", strerror(errno));
1.41 markus 2375: continue;
2376: }
2377: /* Connect it to the display. */
2378: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2379: debug("connect %.100s port %d: %.100s", buf,
2380: 6000 + display_number, strerror(errno));
2381: close(sock);
2382: continue;
2383: }
2384: /* Success */
2385: break;
1.35 markus 2386: }
2387: freeaddrinfo(aitop);
2388: if (!ai) {
1.49 markus 2389: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2390: strerror(errno));
1.51 markus 2391: return -1;
1.25 markus 2392: }
1.51 markus 2393: return sock;
2394: }
2395:
2396: /*
2397: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2398: * the remote channel number. We should do whatever we want, and respond
2399: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2400: */
2401:
2402: void
1.69 markus 2403: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2404: {
1.113 ! markus 2405: Channel *c = NULL;
! 2406: int remote_id, sock = 0;
1.51 markus 2407: char *remote_host;
1.25 markus 2408:
1.113 ! markus 2409: debug("Received X11 open request.");
1.51 markus 2410:
1.113 ! markus 2411: remote_id = packet_get_int();
1.51 markus 2412: if (have_hostname_in_open) {
1.113 ! markus 2413: remote_host = packet_get_string(NULL);
1.51 markus 2414: } else {
2415: remote_host = xstrdup("unknown (remote did not supply name)");
2416: }
1.113 ! markus 2417: packet_done();
1.25 markus 2418:
1.51 markus 2419: /* Obtain a connection to the real X display. */
2420: sock = x11_connect_display();
1.113 ! markus 2421: if (sock != -1) {
! 2422: /* Allocate a channel for this connection. */
! 2423: c = channel_new("connected x11 socket",
! 2424: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
! 2425: remote_host, 1);
! 2426: if (c == NULL) {
! 2427: error("x11_input_open: channel_new failed");
! 2428: close(sock);
! 2429: } else {
! 2430: c->remote_id = remote_id;
! 2431: }
! 2432: }
! 2433: if (c == NULL) {
1.51 markus 2434: /* Send refusal to the remote host. */
2435: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 ! markus 2436: packet_put_int(remote_id);
1.51 markus 2437: } else {
2438: /* Send a confirmation to the remote host. */
2439: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 ! markus 2440: packet_put_int(remote_id);
! 2441: packet_put_int(c->self);
1.51 markus 2442: }
1.113 ! markus 2443: packet_send();
1.72 markus 2444: }
2445:
2446: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2447: void
2448: deny_input_open(int type, int plen, void *ctxt)
2449: {
2450: int rchan = packet_get_int();
2451: switch(type){
2452: case SSH_SMSG_AGENT_OPEN:
2453: error("Warning: ssh server tried agent forwarding.");
2454: break;
2455: case SSH_SMSG_X11_OPEN:
2456: error("Warning: ssh server tried X11 forwarding.");
2457: break;
2458: default:
2459: error("deny_input_open: type %d plen %d", type, plen);
2460: break;
2461: }
2462: error("Warning: this is probably a break in attempt by a malicious server.");
2463: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2464: packet_put_int(rchan);
2465: packet_send();
1.1 deraadt 2466: }
2467:
1.27 markus 2468: /*
2469: * Requests forwarding of X11 connections, generates fake authentication
2470: * data, and enables authentication spoofing.
2471: */
1.1 deraadt 2472:
1.49 markus 2473: void
1.51 markus 2474: x11_request_forwarding_with_spoofing(int client_session_id,
2475: const char *proto, const char *data)
1.1 deraadt 2476: {
1.77 markus 2477: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2478: u_int i, value, len;
1.25 markus 2479: char *new_data;
2480: int screen_number;
2481: const char *cp;
2482: u_int32_t rand = 0;
2483:
2484: cp = getenv("DISPLAY");
2485: if (cp)
2486: cp = strchr(cp, ':');
2487: if (cp)
2488: cp = strchr(cp, '.');
2489: if (cp)
2490: screen_number = atoi(cp + 1);
2491: else
2492: screen_number = 0;
2493:
2494: /* Save protocol name. */
2495: x11_saved_proto = xstrdup(proto);
2496:
1.27 markus 2497: /*
2498: * Extract real authentication data and generate fake data of the
2499: * same length.
2500: */
1.25 markus 2501: x11_saved_data = xmalloc(data_len);
2502: x11_fake_data = xmalloc(data_len);
2503: for (i = 0; i < data_len; i++) {
2504: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2505: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2506: if (i % 4 == 0)
2507: rand = arc4random();
2508: x11_saved_data[i] = value;
2509: x11_fake_data[i] = rand & 0xff;
2510: rand >>= 8;
2511: }
2512: x11_saved_data_len = data_len;
2513: x11_fake_data_len = data_len;
2514:
2515: /* Convert the fake data into hex. */
1.90 markus 2516: len = 2 * data_len + 1;
2517: new_data = xmalloc(len);
1.25 markus 2518: for (i = 0; i < data_len; i++)
1.90 markus 2519: snprintf(new_data + 2 * i, len - 2 * i,
2520: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2521:
2522: /* Send the request packet. */
1.51 markus 2523: if (compat20) {
2524: channel_request_start(client_session_id, "x11-req", 0);
2525: packet_put_char(0); /* XXX bool single connection */
2526: } else {
2527: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2528: }
2529: packet_put_cstring(proto);
2530: packet_put_cstring(new_data);
1.25 markus 2531: packet_put_int(screen_number);
2532: packet_send();
2533: packet_write_wait();
2534: xfree(new_data);
1.1 deraadt 2535: }
2536:
2537: /* Sends a message to the server to request authentication fd forwarding. */
2538:
1.49 markus 2539: void
1.25 markus 2540: auth_request_forwarding()
1.1 deraadt 2541: {
1.25 markus 2542: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2543: packet_send();
2544: packet_write_wait();
1.1 deraadt 2545: }
2546:
1.27 markus 2547: /*
2548: * Returns the name of the forwarded authentication socket. Returns NULL if
2549: * there is no forwarded authentication socket. The returned value points to
2550: * a static buffer.
2551: */
1.1 deraadt 2552:
1.25 markus 2553: char *
2554: auth_get_socket_name()
1.1 deraadt 2555: {
1.25 markus 2556: return channel_forwarded_auth_socket_name;
1.1 deraadt 2557: }
2558:
1.12 markus 2559: /* removes the agent forwarding socket */
2560:
1.49 markus 2561: void
1.25 markus 2562: cleanup_socket(void)
2563: {
1.78 markus 2564: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2565: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2566: }
2567:
1.27 markus 2568: /*
1.59 markus 2569: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2570: * This starts forwarding authentication requests.
2571: */
1.1 deraadt 2572:
1.59 markus 2573: int
1.25 markus 2574: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2575: {
1.113 ! markus 2576: Channel *nc;
! 2577: int sock;
1.25 markus 2578: struct sockaddr_un sunaddr;
2579:
2580: if (auth_get_socket_name() != NULL)
2581: fatal("Protocol error: authentication forwarding requested twice.");
2582:
2583: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2584: temporarily_use_uid(pw);
1.25 markus 2585:
2586: /* Allocate a buffer for the socket name, and format the name. */
2587: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2588: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2589: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2590:
2591: /* Create private directory for socket */
1.59 markus 2592: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2593: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2594: strerror(errno));
2595: restore_uid();
2596: xfree(channel_forwarded_auth_socket_name);
2597: xfree(channel_forwarded_auth_socket_dir);
2598: channel_forwarded_auth_socket_name = NULL;
2599: channel_forwarded_auth_socket_dir = NULL;
2600: return 0;
2601: }
1.25 markus 2602: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2603: channel_forwarded_auth_socket_dir, (int) getpid());
2604:
2605: if (atexit(cleanup_socket) < 0) {
2606: int saved = errno;
2607: cleanup_socket();
2608: packet_disconnect("socket: %.100s", strerror(saved));
2609: }
2610: /* Create the socket. */
2611: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2612: if (sock < 0)
2613: packet_disconnect("socket: %.100s", strerror(errno));
2614:
2615: /* Bind it to the name. */
2616: memset(&sunaddr, 0, sizeof(sunaddr));
2617: sunaddr.sun_family = AF_UNIX;
2618: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2619: sizeof(sunaddr.sun_path));
2620:
2621: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2622: packet_disconnect("bind: %.100s", strerror(errno));
2623:
2624: /* Restore the privileged uid. */
2625: restore_uid();
2626:
2627: /* Start listening on the socket. */
2628: if (listen(sock, 5) < 0)
2629: packet_disconnect("listen: %.100s", strerror(errno));
2630:
2631: /* Allocate a channel for the authentication agent socket. */
1.113 ! markus 2632: nc = channel_new("auth socket",
1.73 markus 2633: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2634: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2635: 0, xstrdup("auth socket"), 1);
1.113 ! markus 2636: if (nc == NULL) {
! 2637: error("auth_input_request_forwarding: channel_new failed");
! 2638: close(sock);
! 2639: return 0;
! 2640: }
! 2641: strlcpy(nc->path, channel_forwarded_auth_socket_name, sizeof(nc->path));
1.59 markus 2642: return 1;
1.1 deraadt 2643: }
2644:
2645: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2646:
1.49 markus 2647: void
1.69 markus 2648: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2649: {
1.113 ! markus 2650: Channel *c = NULL;
! 2651: int remote_id, sock;
1.25 markus 2652: char *dummyname;
1.41 markus 2653:
2654: packet_integrity_check(plen, 4, type);
1.25 markus 2655:
2656: /* Read the remote channel number from the message. */
1.113 ! markus 2657: remote_id = packet_get_int();
1.25 markus 2658:
1.27 markus 2659: /*
2660: * Get a connection to the local authentication agent (this may again
2661: * get forwarded).
2662: */
1.25 markus 2663: sock = ssh_get_authentication_socket();
2664:
1.27 markus 2665: /*
2666: * If we could not connect the agent, send an error message back to
2667: * the server. This should never happen unless the agent dies,
2668: * because authentication forwarding is only enabled if we have an
2669: * agent.
2670: */
1.113 ! markus 2671: if (sock >= 0) {
! 2672: dummyname = xstrdup("authentication agent connection");
! 2673: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, -1, 0, 0, 0, dummyname, 1);
! 2674: if (c == NULL) {
! 2675: error("auth_input_open_request: channel_new failed");
! 2676: close(sock);
! 2677: } else {
! 2678: c->remote_id = remote_id;
! 2679: }
! 2680: }
! 2681: if (c == NULL) {
1.25 markus 2682: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 ! markus 2683: packet_put_int(remote_id);
! 2684: } else {
! 2685: /* Send a confirmation to the remote host. */
! 2686: debug("Forwarding authentication connection.");
! 2687: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
! 2688: packet_put_int(remote_id);
! 2689: packet_put_int(c->self);
1.25 markus 2690: }
1.44 markus 2691: packet_send();
2692: }
2693:
2694: void
1.51 markus 2695: channel_start_open(int id)
1.44 markus 2696: {
2697: Channel *c = channel_lookup(id);
2698: if (c == NULL) {
2699: log("channel_open: %d: bad id", id);
2700: return;
2701: }
1.51 markus 2702: debug("send channel open %d", id);
1.44 markus 2703: packet_start(SSH2_MSG_CHANNEL_OPEN);
2704: packet_put_cstring(c->ctype);
2705: packet_put_int(c->self);
2706: packet_put_int(c->local_window);
2707: packet_put_int(c->local_maxpacket);
1.51 markus 2708: }
2709: void
2710: channel_open(int id)
2711: {
2712: /* XXX REMOVE ME */
2713: channel_start_open(id);
1.44 markus 2714: packet_send();
2715: }
2716: void
2717: channel_request(int id, char *service, int wantconfirm)
2718: {
2719: channel_request_start(id, service, wantconfirm);
2720: packet_send();
2721: debug("channel request %d: %s", id, service) ;
2722: }
2723: void
2724: channel_request_start(int id, char *service, int wantconfirm)
2725: {
2726: Channel *c = channel_lookup(id);
2727: if (c == NULL) {
2728: log("channel_request: %d: bad id", id);
2729: return;
2730: }
2731: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2732: packet_put_int(c->remote_id);
2733: packet_put_cstring(service);
2734: packet_put_char(wantconfirm);
2735: }
2736: void
2737: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2738: {
2739: Channel *c = channel_lookup(id);
2740: if (c == NULL) {
2741: log("channel_register_callback: %d: bad id", id);
2742: return;
2743: }
2744: c->cb_event = mtype;
2745: c->cb_fn = fn;
2746: c->cb_arg = arg;
2747: }
2748: void
2749: channel_register_cleanup(int id, channel_callback_fn *fn)
2750: {
2751: Channel *c = channel_lookup(id);
2752: if (c == NULL) {
2753: log("channel_register_cleanup: %d: bad id", id);
2754: return;
2755: }
2756: c->dettach_user = fn;
2757: }
2758: void
2759: channel_cancel_cleanup(int id)
2760: {
2761: Channel *c = channel_lookup(id);
2762: if (c == NULL) {
2763: log("channel_cancel_cleanup: %d: bad id", id);
2764: return;
2765: }
2766: c->dettach_user = NULL;
1.65 markus 2767: }
1.89 stevesk 2768: void
1.65 markus 2769: channel_register_filter(int id, channel_filter_fn *fn)
2770: {
2771: Channel *c = channel_lookup(id);
2772: if (c == NULL) {
2773: log("channel_register_filter: %d: bad id", id);
2774: return;
2775: }
2776: c->input_filter = fn;
1.44 markus 2777: }
2778:
2779: void
1.71 markus 2780: channel_set_fds(int id, int rfd, int wfd, int efd,
2781: int extusage, int nonblock)
1.44 markus 2782: {
2783: Channel *c = channel_lookup(id);
2784: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2785: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2786: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2787: c->type = SSH_CHANNEL_OPEN;
2788: /* XXX window size? */
1.68 markus 2789: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2790: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2791: packet_put_int(c->remote_id);
2792: packet_put_int(c->local_window);
1.25 markus 2793: packet_send();
1.1 deraadt 2794: }
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