Annotation of src/usr.bin/ssh/channels.c, Revision 1.103
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"
1.103 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.102 2001/04/06 21:00:10 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: */
1.1 deraadt 75: static Channel *channels = NULL;
76:
1.27 markus 77: /*
78: * Size of the channel array. All slots of the array must always be
79: * initialized (at least the type field); unused slots are marked with type
80: * SSH_CHANNEL_FREE.
81: */
1.1 deraadt 82: static int channels_alloc = 0;
83:
1.27 markus 84: /*
85: * Maximum file descriptor value used in any of the channels. This is
86: * updated in channel_allocate.
87: */
1.84 markus 88: static int channel_max_fd = 0;
1.1 deraadt 89:
1.12 markus 90: /* Name and directory of socket for authentication agent forwarding. */
1.1 deraadt 91: static char *channel_forwarded_auth_socket_name = NULL;
1.25 markus 92: static char *channel_forwarded_auth_socket_dir = NULL;
1.1 deraadt 93:
94: /* Saved X11 authentication protocol name. */
95: char *x11_saved_proto = NULL;
96:
97: /* Saved X11 authentication data. This is the real data. */
98: char *x11_saved_data = NULL;
1.77 markus 99: u_int x11_saved_data_len = 0;
1.1 deraadt 100:
1.27 markus 101: /*
102: * Fake X11 authentication data. This is what the server will be sending us;
103: * we should replace any occurrences of this by the real data.
104: */
1.1 deraadt 105: char *x11_fake_data = NULL;
1.77 markus 106: u_int x11_fake_data_len;
1.1 deraadt 107:
1.27 markus 108: /*
109: * Data structure for storing which hosts are permitted for forward requests.
110: * The local sides of any remote forwards are stored in this array to prevent
111: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
112: * network (which might be behind a firewall).
113: */
1.25 markus 114: typedef struct {
1.41 markus 115: char *host_to_connect; /* Connect to 'host'. */
116: u_short port_to_connect; /* Connect to 'port'. */
117: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 118: } ForwardPermission;
119:
120: /* List of all permitted host/port pairs to connect. */
121: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
122: /* Number of permitted host/port pairs in the array. */
123: static int num_permitted_opens = 0;
1.27 markus 124: /*
125: * If this is true, all opens are permitted. This is the case on the server
126: * on which we have to trust the client anyway, and the user could do
127: * anything after logging in anyway.
128: */
1.1 deraadt 129: static int all_opens_permitted = 0;
130:
131: /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
132: static int have_hostname_in_open = 0;
1.82 markus 133:
134: /* AF_UNSPEC or AF_INET or AF_INET6 */
135: extern int IPv4or6;
1.1 deraadt 136:
1.103 ! markus 137: void port_open_helper(Channel *c, char *rtype);
! 138:
1.1 deraadt 139: /* Sets specific protocol options. */
140:
1.49 markus 141: void
1.25 markus 142: channel_set_options(int hostname_in_open)
1.1 deraadt 143: {
1.25 markus 144: have_hostname_in_open = hostname_in_open;
1.1 deraadt 145: }
146:
1.41 markus 147: /* lookup channel by id */
148:
149: Channel *
150: channel_lookup(int id)
151: {
152: Channel *c;
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: }
157: c = &channels[id];
158: if (c->type == SSH_CHANNEL_FREE) {
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:
215: int
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;
226: channels = xmalloc(channels_alloc * sizeof(Channel));
227: for (i = 0; i < channels_alloc; i++)
228: channels[i].type = SSH_CHANNEL_FREE;
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++)
237: if (channels[i].type == SSH_CHANNEL_FREE) {
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);
1.25 markus 247: channels = xrealloc(channels, channels_alloc * sizeof(Channel));
248: for (i = found; i < channels_alloc; i++)
249: channels[i].type = SSH_CHANNEL_FREE;
250: }
251: /* Initialize and return new channel number. */
252: c = &channels[found];
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);
275: return found;
1.1 deraadt 276: }
1.52 markus 277: /* old interface XXX */
1.49 markus 278: int
1.41 markus 279: channel_allocate(int type, int sock, char *remote_name)
280: {
1.71 markus 281: return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
1.41 markus 282: }
1.1 deraadt 283:
1.52 markus 284:
285: /* Close all channel fd/socket. */
286:
287: void
288: channel_close_fds(Channel *c)
289: {
290: if (c->sock != -1) {
291: close(c->sock);
292: c->sock = -1;
293: }
294: if (c->rfd != -1) {
295: close(c->rfd);
296: c->rfd = -1;
297: }
298: if (c->wfd != -1) {
299: close(c->wfd);
300: c->wfd = -1;
301: }
302: if (c->efd != -1) {
303: close(c->efd);
304: c->efd = -1;
305: }
306: }
307:
308: /* Free the channel and close its fd/socket. */
1.1 deraadt 309:
1.49 markus 310: void
1.41 markus 311: channel_free(int id)
1.1 deraadt 312: {
1.41 markus 313: Channel *c = channel_lookup(id);
1.79 markus 314: char *s = channel_open_message();
315:
1.41 markus 316: if (c == NULL)
317: packet_disconnect("channel free: bad local channel %d", id);
1.79 markus 318: debug("channel_free: channel %d: status: %s", id, s);
319: xfree(s);
320:
1.44 markus 321: if (c->dettach_user != NULL) {
322: debug("channel_free: channel %d: dettaching channel user", id);
323: c->dettach_user(c->self, NULL);
324: }
1.54 markus 325: if (c->sock != -1)
326: shutdown(c->sock, SHUT_RDWR);
1.52 markus 327: channel_close_fds(c);
1.41 markus 328: buffer_free(&c->input);
329: buffer_free(&c->output);
330: buffer_free(&c->extended);
331: c->type = SSH_CHANNEL_FREE;
332: if (c->remote_name) {
333: xfree(c->remote_name);
334: c->remote_name = NULL;
1.25 markus 335: }
1.1 deraadt 336: }
337:
1.27 markus 338: /*
1.41 markus 339: * 'channel_pre*' are called just before select() to add any bits relevant to
340: * channels in the select bitmasks.
341: */
342: /*
343: * 'channel_post*': perform any appropriate operations for channels which
344: * have events pending.
1.27 markus 345: */
1.41 markus 346: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
347: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
348: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
349:
350: void
351: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
352: {
353: FD_SET(c->sock, readset);
354: }
355:
356: void
1.75 markus 357: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
358: {
359: debug3("channel %d: waiting for connection", c->self);
360: FD_SET(c->sock, writeset);
361: }
362:
363: void
1.41 markus 364: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
365: {
366: if (buffer_len(&c->input) < packet_get_maxsize())
367: FD_SET(c->sock, readset);
368: if (buffer_len(&c->output) > 0)
369: FD_SET(c->sock, writeset);
370: }
1.1 deraadt 371:
1.41 markus 372: void
373: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
374: {
375: /* test whether sockets are 'alive' for read/write */
376: if (c->istate == CHAN_INPUT_OPEN)
377: if (buffer_len(&c->input) < packet_get_maxsize())
378: FD_SET(c->sock, readset);
379: if (c->ostate == CHAN_OUTPUT_OPEN ||
380: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
381: if (buffer_len(&c->output) > 0) {
382: FD_SET(c->sock, writeset);
383: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
384: chan_obuf_empty(c);
385: }
386: }
387: }
388:
389: void
1.44 markus 390: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
391: {
392: if (c->istate == CHAN_INPUT_OPEN &&
393: c->remote_window > 0 &&
394: buffer_len(&c->input) < c->remote_window)
395: FD_SET(c->rfd, readset);
396: if (c->ostate == CHAN_OUTPUT_OPEN ||
397: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
398: if (buffer_len(&c->output) > 0) {
399: FD_SET(c->wfd, writeset);
400: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
401: chan_obuf_empty(c);
402: }
403: }
404: /** XXX check close conditions, too */
405: if (c->efd != -1) {
406: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
407: buffer_len(&c->extended) > 0)
408: FD_SET(c->efd, writeset);
409: else if (c->extended_usage == CHAN_EXTENDED_READ &&
410: buffer_len(&c->extended) < c->remote_window)
411: FD_SET(c->efd, readset);
412: }
413: }
414:
415: void
1.41 markus 416: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
417: {
418: if (buffer_len(&c->input) == 0) {
419: packet_start(SSH_MSG_CHANNEL_CLOSE);
420: packet_put_int(c->remote_id);
421: packet_send();
422: c->type = SSH_CHANNEL_CLOSED;
423: debug("Closing channel %d after input drain.", c->self);
424: }
425: }
426:
427: void
428: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
429: {
430: if (buffer_len(&c->output) == 0)
431: channel_free(c->self);
1.49 markus 432: else
1.41 markus 433: FD_SET(c->sock, writeset);
434: }
435:
436: /*
437: * This is a special state for X11 authentication spoofing. An opened X11
438: * connection (when authentication spoofing is being done) remains in this
439: * state until the first packet has been completely read. The authentication
440: * data in that packet is then substituted by the real data if it matches the
441: * fake data, and the channel is put into normal mode.
1.51 markus 442: * XXX All this happens at the client side.
1.41 markus 443: */
444: int
445: x11_open_helper(Channel *c)
1.1 deraadt 446: {
1.77 markus 447: u_char *ucp;
448: u_int proto_len, data_len;
1.25 markus 449:
1.41 markus 450: /* Check if the fixed size part of the packet is in buffer. */
451: if (buffer_len(&c->output) < 12)
452: return 0;
453:
454: /* Parse the lengths of variable-length fields. */
1.77 markus 455: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 456: if (ucp[0] == 0x42) { /* Byte order MSB first. */
457: proto_len = 256 * ucp[6] + ucp[7];
458: data_len = 256 * ucp[8] + ucp[9];
459: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
460: proto_len = ucp[6] + 256 * ucp[7];
461: data_len = ucp[8] + 256 * ucp[9];
462: } else {
463: debug("Initial X11 packet contains bad byte order byte: 0x%x",
464: ucp[0]);
465: return -1;
466: }
467:
468: /* Check if the whole packet is in buffer. */
469: if (buffer_len(&c->output) <
470: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
471: return 0;
472:
473: /* Check if authentication protocol matches. */
474: if (proto_len != strlen(x11_saved_proto) ||
475: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
476: debug("X11 connection uses different authentication protocol.");
477: return -1;
478: }
479: /* Check if authentication data matches our fake data. */
480: if (data_len != x11_fake_data_len ||
481: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
482: x11_fake_data, x11_fake_data_len) != 0) {
483: debug("X11 auth data does not match fake data.");
484: return -1;
485: }
486: /* Check fake data length */
487: if (x11_fake_data_len != x11_saved_data_len) {
488: error("X11 fake_data_len %d != saved_data_len %d",
489: x11_fake_data_len, x11_saved_data_len);
490: return -1;
491: }
492: /*
493: * Received authentication protocol and data match
494: * our fake data. Substitute the fake data with real
495: * data.
496: */
497: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
498: x11_saved_data, x11_saved_data_len);
499: return 1;
500: }
501:
502: void
503: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
504: {
505: int ret = x11_open_helper(c);
506: if (ret == 1) {
507: /* Start normal processing for the channel. */
508: c->type = SSH_CHANNEL_OPEN;
1.47 markus 509: channel_pre_open_13(c, readset, writeset);
1.41 markus 510: } else if (ret == -1) {
511: /*
512: * We have received an X11 connection that has bad
513: * authentication information.
514: */
1.98 millert 515: log("X11 connection rejected because of wrong authentication.");
1.41 markus 516: buffer_clear(&c->input);
517: buffer_clear(&c->output);
518: close(c->sock);
519: c->sock = -1;
520: c->type = SSH_CHANNEL_CLOSED;
521: packet_start(SSH_MSG_CHANNEL_CLOSE);
522: packet_put_int(c->remote_id);
523: packet_send();
524: }
525: }
1.25 markus 526:
1.41 markus 527: void
1.51 markus 528: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 529: {
530: int ret = x11_open_helper(c);
531: if (ret == 1) {
532: c->type = SSH_CHANNEL_OPEN;
1.57 markus 533: if (compat20)
534: channel_pre_open_20(c, readset, writeset);
535: else
536: channel_pre_open_15(c, readset, writeset);
1.41 markus 537: } else if (ret == -1) {
538: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 539: chan_read_failed(c); /** force close? */
1.41 markus 540: chan_write_failed(c);
541: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
542: }
543: }
1.25 markus 544:
1.103 ! markus 545: #define SSH_SOCKS_HEAD 1+1+2+4
! 546:
! 547: void
! 548: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
! 549: {
! 550: u_char *p, *host;
! 551: int len, i, done, have;
! 552: char username[256];
! 553: struct {
! 554: u_int8_t version;
! 555: u_int8_t command;
! 556: u_int16_t dest_port;
! 557: struct in_addr dest_ip;
! 558: } s4_req, s4_rsp;
! 559:
! 560: have = buffer_len(&c->input);
! 561:
! 562: debug("channel %d: pre_dynamic have: %d", c->self, have);
! 563: /*buffer_dump(&c->input);*/
! 564:
! 565: /* Check if the fixed size part of the packet is in buffer. */
! 566: if (have < SSH_SOCKS_HEAD + 1) {
! 567: /* need more */
! 568: FD_SET(c->sock, readset);
! 569: return;
! 570: }
! 571: /* Check for end of username */
! 572: p = buffer_ptr(&c->input);
! 573: done = 0;
! 574: for (i = SSH_SOCKS_HEAD; i < have; i++) {
! 575: if (p[i] == '\0') {
! 576: done = 1;
! 577: break;
! 578: }
! 579: }
! 580: if (!done) {
! 581: /* need more */
! 582: FD_SET(c->sock, readset);
! 583: return;
! 584: }
! 585: buffer_get(&c->input, (char *)&s4_req.version, 1);
! 586: buffer_get(&c->input, (char *)&s4_req.command, 1);
! 587: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
! 588: buffer_get(&c->input, (char *)&s4_req.dest_ip, 4);
! 589: p = buffer_ptr(&c->input);
! 590: len = strlen(p);
! 591: have = buffer_len(&c->input);
! 592: debug2("channel %d: pre_dynamic user: %s/%d", c->self, p, len);
! 593: if (len > have)
! 594: fatal("channel %d: pre_dynamic: len %d > have %d",
! 595: c->self, len, have);
! 596: strlcpy(username, p, sizeof(username));
! 597: buffer_consume(&c->input, len);
! 598: buffer_consume(&c->input, 1); /* trailing '\0' */
! 599:
! 600: host = inet_ntoa(s4_req.dest_ip);
! 601: strlcpy(c->path, host, sizeof(c->path));
! 602: c->host_port = ntohs(s4_req.dest_port);
! 603:
! 604: debug("channel %d: dynamic request received: "
! 605: "socks%x://%s@%s:%u/command?%u",
! 606: c->self, s4_req.version, username, host, c->host_port,
! 607: s4_req.command);
! 608:
! 609: if ((s4_req.version != 4) || (s4_req.command != 1)) {
! 610: debug("channel %d: cannot handle: socks VN %d CN %d",
! 611: c->self, s4_req.version, s4_req.command);
! 612: channel_free(c->self);
! 613: return;
! 614: }
! 615:
! 616: s4_rsp.version = 0; /* VN: version of reply code */
! 617: s4_rsp.command = 90; /* CD: request granted */
! 618: s4_rsp.dest_port = 0; /* ignored */
! 619: s4_rsp.dest_ip.s_addr = INADDR_ANY; /* ignored */
! 620: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
! 621:
! 622: /* switch to next state */
! 623: c->type = SSH_CHANNEL_OPENING;
! 624: port_open_helper(c, "direct-tcpip");
! 625: }
! 626:
! 627:
1.41 markus 628: /* This is our fake X11 server socket. */
629: void
630: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
631: {
632: struct sockaddr addr;
633: int newsock, newch;
634: socklen_t addrlen;
1.85 markus 635: char buf[16384], *remote_ipaddr;
1.51 markus 636: int remote_port;
1.25 markus 637:
1.41 markus 638: if (FD_ISSET(c->sock, readset)) {
639: debug("X11 connection requested.");
640: addrlen = sizeof(addr);
641: newsock = accept(c->sock, &addr, &addrlen);
642: if (newsock < 0) {
643: error("accept: %.100s", strerror(errno));
644: return;
645: }
1.85 markus 646: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 647: remote_port = get_peer_port(newsock);
1.41 markus 648: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 649: remote_ipaddr, remote_port);
1.51 markus 650:
651: newch = channel_new("x11",
652: SSH_CHANNEL_OPENING, newsock, newsock, -1,
653: c->local_window_max, c->local_maxpacket,
1.71 markus 654: 0, xstrdup(buf), 1);
1.51 markus 655: if (compat20) {
656: packet_start(SSH2_MSG_CHANNEL_OPEN);
657: packet_put_cstring("x11");
658: packet_put_int(newch);
659: packet_put_int(c->local_window_max);
660: packet_put_int(c->local_maxpacket);
1.85 markus 661: /* originator ipaddr and port */
662: packet_put_cstring(remote_ipaddr);
1.57 markus 663: if (datafellows & SSH_BUG_X11FWD) {
664: debug("ssh2 x11 bug compat mode");
665: } else {
666: packet_put_int(remote_port);
667: }
1.51 markus 668: packet_send();
669: } else {
670: packet_start(SSH_SMSG_X11_OPEN);
671: packet_put_int(newch);
672: if (have_hostname_in_open)
673: packet_put_string(buf, strlen(buf));
674: packet_send();
675: }
1.85 markus 676: xfree(remote_ipaddr);
1.41 markus 677: }
678: }
1.25 markus 679:
1.103 ! markus 680: void
! 681: port_open_helper(Channel *c, char *rtype)
! 682: {
! 683: int direct;
! 684: char buf[1024];
! 685: char *remote_ipaddr = get_peer_ipaddr(c->sock);
! 686: u_short remote_port = get_peer_port(c->sock);
! 687:
! 688: direct = (strcmp(rtype, "direct-tcpip") == 0);
! 689:
! 690: snprintf(buf, sizeof buf,
! 691: "%s: listening port %d for %.100s port %d, "
! 692: "connect from %.200s port %d",
! 693: rtype, c->listening_port, c->path, c->host_port,
! 694: remote_ipaddr, remote_port);
! 695:
! 696: xfree(c->remote_name);
! 697: c->remote_name = xstrdup(buf);
! 698:
! 699: if (compat20) {
! 700: packet_start(SSH2_MSG_CHANNEL_OPEN);
! 701: packet_put_cstring(rtype);
! 702: packet_put_int(c->self);
! 703: packet_put_int(c->local_window_max);
! 704: packet_put_int(c->local_maxpacket);
! 705: if (direct) {
! 706: /* target host, port */
! 707: packet_put_cstring(c->path);
! 708: packet_put_int(c->host_port);
! 709: } else {
! 710: /* listen address, port */
! 711: packet_put_cstring(c->path);
! 712: packet_put_int(c->listening_port);
! 713: }
! 714: /* originator host and port */
! 715: packet_put_cstring(remote_ipaddr);
! 716: packet_put_int(remote_port);
! 717: packet_send();
! 718: } else {
! 719: packet_start(SSH_MSG_PORT_OPEN);
! 720: packet_put_int(c->self);
! 721: packet_put_cstring(c->path);
! 722: packet_put_int(c->host_port);
! 723: if (have_hostname_in_open)
! 724: packet_put_cstring(c->remote_name);
! 725: packet_send();
! 726: }
! 727: xfree(remote_ipaddr);
! 728: }
! 729:
1.41 markus 730: /*
731: * This socket is listening for connections to a forwarded TCP/IP port.
732: */
733: void
734: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
735: {
1.103 ! markus 736: Channel *nc;
1.41 markus 737: struct sockaddr addr;
1.103 ! markus 738: int newsock, newch, nextstate;
1.41 markus 739: socklen_t addrlen;
1.103 ! markus 740: char *rtype;
1.73 markus 741:
1.41 markus 742: if (FD_ISSET(c->sock, readset)) {
743: debug("Connection to port %d forwarding "
744: "to %.100s port %d requested.",
745: c->listening_port, c->path, c->host_port);
1.103 ! markus 746:
! 747: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
! 748: "forwarded-tcpip" : "direct-tcpip";
! 749: nextstate = (c->host_port == 0) ? SSH_CHANNEL_DYNAMIC :
! 750: SSH_CHANNEL_OPENING;
! 751:
1.41 markus 752: addrlen = sizeof(addr);
753: newsock = accept(c->sock, &addr, &addrlen);
754: if (newsock < 0) {
755: error("accept: %.100s", strerror(errno));
756: return;
757: }
1.73 markus 758: newch = channel_new(rtype,
1.103 ! markus 759: nextstate, newsock, newsock, -1,
1.41 markus 760: c->local_window_max, c->local_maxpacket,
1.103 ! markus 761: 0, xstrdup(rtype), 1);
! 762:
! 763: nc = channel_lookup(newch);
! 764: if (nc == NULL) {
! 765: error("xxx: no new channel:");
! 766: return;
1.41 markus 767: }
1.103 ! markus 768: nc->listening_port = c->listening_port;
! 769: nc->host_port = c->host_port;
! 770: strlcpy(nc->path, c->path, sizeof(nc->path));
! 771:
! 772: if (nextstate != SSH_CHANNEL_DYNAMIC)
! 773: port_open_helper(nc, rtype);
1.41 markus 774: }
775: }
1.25 markus 776:
1.41 markus 777: /*
778: * This is the authentication agent socket listening for connections from
779: * clients.
780: */
781: void
782: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
783: {
784: struct sockaddr addr;
785: int newsock, newch;
786: socklen_t addrlen;
1.25 markus 787:
1.41 markus 788: if (FD_ISSET(c->sock, readset)) {
789: addrlen = sizeof(addr);
790: newsock = accept(c->sock, &addr, &addrlen);
791: if (newsock < 0) {
792: error("accept from auth socket: %.100s", strerror(errno));
793: return;
794: }
1.73 markus 795: newch = channel_new("accepted auth socket",
796: SSH_CHANNEL_OPENING, newsock, newsock, -1,
797: c->local_window_max, c->local_maxpacket,
798: 0, xstrdup("accepted auth socket"), 1);
799: if (compat20) {
800: packet_start(SSH2_MSG_CHANNEL_OPEN);
801: packet_put_cstring("auth-agent@openssh.com");
802: packet_put_int(newch);
803: packet_put_int(c->local_window_max);
804: packet_put_int(c->local_maxpacket);
805: } else {
806: packet_start(SSH_SMSG_AGENT_OPEN);
807: packet_put_int(newch);
808: }
1.41 markus 809: packet_send();
810: }
811: }
1.25 markus 812:
1.75 markus 813: void
814: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
815: {
816: if (FD_ISSET(c->sock, writeset)) {
817: int err = 0;
818: int sz = sizeof(err);
819: c->type = SSH_CHANNEL_OPEN;
1.89 stevesk 820: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
1.75 markus 821: debug("getsockopt SO_ERROR failed");
822: } else {
823: if (err == 0) {
824: debug("channel %d: connected)", c->self);
825: } else {
826: debug("channel %d: not connected: %s",
827: c->self, strerror(err));
828: chan_read_failed(c);
829: chan_write_failed(c);
830: }
831: }
832: }
833: }
834:
1.41 markus 835: int
836: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
837: {
838: char buf[16*1024];
839: int len;
1.25 markus 840:
1.41 markus 841: if (c->rfd != -1 &&
842: FD_ISSET(c->rfd, readset)) {
843: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 844: if (len < 0 && (errno == EINTR || errno == EAGAIN))
845: return 1;
1.41 markus 846: if (len <= 0) {
1.51 markus 847: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 848: c->self, c->rfd, len);
1.103 ! markus 849: if (c->type == SSH_CHANNEL_DYNAMIC) {
! 850: /*
! 851: * we are not yet connected to a remote peer,
! 852: * so the connection-close protocol won't work
! 853: */
! 854: debug("channel %d: dynamic: closed", c->self);
! 855: channel_free(c->self);
! 856: return -1;
! 857: }
1.25 markus 858: if (compat13) {
1.41 markus 859: buffer_consume(&c->output, buffer_len(&c->output));
860: c->type = SSH_CHANNEL_INPUT_DRAINING;
861: debug("Channel %d status set to input draining.", c->self);
1.25 markus 862: } else {
1.41 markus 863: chan_read_failed(c);
1.25 markus 864: }
1.41 markus 865: return -1;
866: }
1.65 markus 867: if(c->input_filter != NULL) {
1.66 markus 868: if (c->input_filter(c, buf, len) == -1) {
1.65 markus 869: debug("filter stops channel %d", c->self);
870: chan_read_failed(c);
871: }
872: } else {
873: buffer_append(&c->input, buf, len);
874: }
1.41 markus 875: }
876: return 1;
877: }
878: int
879: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
880: {
1.95 markus 881: struct termios tio;
1.41 markus 882: int len;
1.25 markus 883:
1.41 markus 884: /* Send buffered output data to the socket. */
885: if (c->wfd != -1 &&
886: FD_ISSET(c->wfd, writeset) &&
887: buffer_len(&c->output) > 0) {
888: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 889: buffer_len(&c->output));
890: if (len < 0 && (errno == EINTR || errno == EAGAIN))
891: return 1;
1.41 markus 892: if (len <= 0) {
893: if (compat13) {
894: buffer_consume(&c->output, buffer_len(&c->output));
895: debug("Channel %d status set to input draining.", c->self);
896: c->type = SSH_CHANNEL_INPUT_DRAINING;
897: } else {
898: chan_write_failed(c);
899: }
900: return -1;
1.91 markus 901: }
902: if (compat20 && c->isatty) {
903: if (tcgetattr(c->wfd, &tio) == 0 &&
904: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
905: /*
906: * Simulate echo to reduce the impact of
1.96 markus 907: * traffic analysis. We need to match the
1.95 markus 908: * size of a SSH2_MSG_CHANNEL_DATA message
909: * (4 byte channel id + data)
1.91 markus 910: */
1.95 markus 911: packet_send_ignore(4 + len);
1.91 markus 912: packet_send();
913: }
1.25 markus 914: }
1.41 markus 915: buffer_consume(&c->output, len);
1.44 markus 916: if (compat20 && len > 0) {
917: c->local_consumed += len;
918: }
919: }
920: return 1;
921: }
922: int
923: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
924: {
925: char buf[16*1024];
926: int len;
927:
1.45 markus 928: /** XXX handle drain efd, too */
1.44 markus 929: if (c->efd != -1) {
930: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
931: FD_ISSET(c->efd, writeset) &&
932: buffer_len(&c->extended) > 0) {
933: len = write(c->efd, buffer_ptr(&c->extended),
934: buffer_len(&c->extended));
1.70 markus 935: debug2("channel %d: written %d to efd %d",
1.44 markus 936: c->self, len, c->efd);
1.93 markus 937: if (len < 0 && (errno == EINTR || errno == EAGAIN))
938: return 1;
939: if (len <= 0) {
940: debug2("channel %d: closing write-efd %d",
941: c->self, c->efd);
942: close(c->efd);
943: c->efd = -1;
944: } else {
1.44 markus 945: buffer_consume(&c->extended, len);
946: c->local_consumed += len;
947: }
948: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
949: FD_ISSET(c->efd, readset)) {
950: len = read(c->efd, buf, sizeof(buf));
1.70 markus 951: debug2("channel %d: read %d from efd %d",
1.44 markus 952: c->self, len, c->efd);
1.93 markus 953: if (len < 0 && (errno == EINTR || errno == EAGAIN))
954: return 1;
955: if (len <= 0) {
956: debug2("channel %d: closing read-efd %d",
1.45 markus 957: c->self, c->efd);
958: close(c->efd);
959: c->efd = -1;
1.93 markus 960: } else {
1.44 markus 961: buffer_append(&c->extended, buf, len);
1.93 markus 962: }
1.44 markus 963: }
964: }
965: return 1;
966: }
967: int
1.93 markus 968: channel_check_window(Channel *c)
1.44 markus 969: {
1.46 markus 970: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 971: c->local_window < c->local_window_max/2 &&
972: c->local_consumed > 0) {
973: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
974: packet_put_int(c->remote_id);
975: packet_put_int(c->local_consumed);
976: packet_send();
1.70 markus 977: debug2("channel %d: window %d sent adjust %d",
1.44 markus 978: c->self, c->local_window,
979: c->local_consumed);
980: c->local_window += c->local_consumed;
981: c->local_consumed = 0;
1.1 deraadt 982: }
1.41 markus 983: return 1;
1.1 deraadt 984: }
985:
1.41 markus 986: void
987: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
988: {
989: channel_handle_rfd(c, readset, writeset);
990: channel_handle_wfd(c, readset, writeset);
991: }
1.1 deraadt 992:
1.41 markus 993: void
1.44 markus 994: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
995: {
996: channel_handle_rfd(c, readset, writeset);
997: channel_handle_wfd(c, readset, writeset);
998: channel_handle_efd(c, readset, writeset);
1.93 markus 999:
1000: channel_check_window(c);
1.44 markus 1001: }
1002:
1003: void
1.41 markus 1004: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1005: {
1.41 markus 1006: int len;
1007: /* Send buffered output data to the socket. */
1008: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1009: len = write(c->sock, buffer_ptr(&c->output),
1010: buffer_len(&c->output));
1011: if (len <= 0)
1012: buffer_consume(&c->output, buffer_len(&c->output));
1013: else
1014: buffer_consume(&c->output, len);
1015: }
1016: }
1.25 markus 1017:
1.41 markus 1018: void
1.103 ! markus 1019: channel_post_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
! 1020: {
! 1021: channel_handle_rfd(c, readset, writeset);
! 1022: }
! 1023:
! 1024: void
1.44 markus 1025: channel_handler_init_20(void)
1026: {
1027: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1028: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1029: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1030: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1031: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1032: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1033: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 ! markus 1034: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1035:
1036: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1037: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1038: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1039: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1040: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1041: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.103 ! markus 1042: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_dynamic;
1.44 markus 1043: }
1044:
1045: void
1.41 markus 1046: channel_handler_init_13(void)
1047: {
1048: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1049: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1050: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1051: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1052: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1053: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1054: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1055: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 ! markus 1056: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1057:
1.41 markus 1058: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1059: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1060: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1061: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1062: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1063: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.103 ! markus 1064: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_dynamic;
1.41 markus 1065: }
1.25 markus 1066:
1.41 markus 1067: void
1068: channel_handler_init_15(void)
1069: {
1070: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1071: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1072: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1073: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1074: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1075: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 ! markus 1076: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1077:
1.41 markus 1078: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1079: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1080: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1081: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1082: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.103 ! markus 1083: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_dynamic;
1.41 markus 1084: }
1.27 markus 1085:
1.41 markus 1086: void
1087: channel_handler_init(void)
1088: {
1089: int i;
1090: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1091: channel_pre[i] = NULL;
1092: channel_post[i] = NULL;
1093: }
1.44 markus 1094: if (compat20)
1095: channel_handler_init_20();
1096: else if (compat13)
1.41 markus 1097: channel_handler_init_13();
1098: else
1099: channel_handler_init_15();
1100: }
1.25 markus 1101:
1.49 markus 1102: void
1.41 markus 1103: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1104: {
1105: static int did_init = 0;
1106: int i;
1107: Channel *c;
1.25 markus 1108:
1.41 markus 1109: if (!did_init) {
1110: channel_handler_init();
1111: did_init = 1;
1112: }
1113: for (i = 0; i < channels_alloc; i++) {
1114: c = &channels[i];
1115: if (c->type == SSH_CHANNEL_FREE)
1116: continue;
1117: if (ftab[c->type] == NULL)
1.25 markus 1118: continue;
1.41 markus 1119: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1120: if (chan_is_dead(c)) {
1121: /*
1122: * we have to remove the fd's from the select mask
1123: * before the channels are free'd and the fd's are
1124: * closed
1125: */
1126: if (c->wfd != -1)
1127: FD_CLR(c->wfd, writeset);
1128: if (c->rfd != -1)
1129: FD_CLR(c->rfd, readset);
1130: if (c->efd != -1) {
1131: if (c->extended_usage == CHAN_EXTENDED_READ)
1132: FD_CLR(c->efd, readset);
1133: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1134: FD_CLR(c->efd, writeset);
1135: }
1136: channel_free(c->self);
1137: }
1.1 deraadt 1138: }
1139: }
1140:
1.49 markus 1141: void
1.100 markus 1142: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1143: int rekeying)
1.41 markus 1144: {
1.84 markus 1145: int n;
1146: u_int sz;
1147:
1148: n = MAX(*maxfdp, channel_max_fd);
1149:
1150: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1151: if (*readsetp == NULL || n > *maxfdp) {
1152: if (*readsetp)
1153: xfree(*readsetp);
1154: if (*writesetp)
1155: xfree(*writesetp);
1156: *readsetp = xmalloc(sz);
1157: *writesetp = xmalloc(sz);
1158: *maxfdp = n;
1159: }
1160: memset(*readsetp, 0, sz);
1161: memset(*writesetp, 0, sz);
1162:
1.100 markus 1163: if (!rekeying)
1164: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1165: }
1166:
1.49 markus 1167: void
1.41 markus 1168: channel_after_select(fd_set * readset, fd_set * writeset)
1169: {
1170: channel_handler(channel_post, readset, writeset);
1171: }
1172:
1.84 markus 1173: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1174:
1.49 markus 1175: void
1.25 markus 1176: channel_output_poll()
1.1 deraadt 1177: {
1.25 markus 1178: int len, i;
1.41 markus 1179: Channel *c;
1.1 deraadt 1180:
1.25 markus 1181: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1182: c = &channels[i];
1.37 markus 1183:
1.27 markus 1184: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1185: if (compat13) {
1.41 markus 1186: if (c->type != SSH_CHANNEL_OPEN &&
1187: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1188: continue;
1189: } else {
1.41 markus 1190: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1191: continue;
1192: }
1.46 markus 1193: if (compat20 &&
1194: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1195: /* XXX is this true? */
1.97 markus 1196: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1197: continue;
1198: }
1.25 markus 1199:
1200: /* Get the amount of buffered data for this channel. */
1.93 markus 1201: if ((c->istate == CHAN_INPUT_OPEN ||
1202: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1203: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1204: /* Send some data for the other side over the secure connection. */
1.44 markus 1205: if (compat20) {
1206: if (len > c->remote_window)
1207: len = c->remote_window;
1208: if (len > c->remote_maxpacket)
1209: len = c->remote_maxpacket;
1.25 markus 1210: } else {
1.44 markus 1211: if (packet_is_interactive()) {
1212: if (len > 1024)
1213: len = 512;
1214: } else {
1215: /* Keep the packets at reasonable size. */
1216: if (len > packet_get_maxsize()/2)
1217: len = packet_get_maxsize()/2;
1218: }
1.25 markus 1219: }
1.41 markus 1220: if (len > 0) {
1.44 markus 1221: packet_start(compat20 ?
1222: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1223: packet_put_int(c->remote_id);
1224: packet_put_string(buffer_ptr(&c->input), len);
1225: packet_send();
1226: buffer_consume(&c->input, len);
1227: c->remote_window -= len;
1228: }
1229: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1230: if (compat13)
1231: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1232: /*
1233: * input-buffer is empty and read-socket shutdown:
1234: * tell peer, that we will not send more data: send IEOF
1235: */
1.41 markus 1236: chan_ibuf_empty(c);
1.25 markus 1237: }
1.44 markus 1238: /* Send extended data, i.e. stderr */
1239: if (compat20 &&
1240: c->remote_window > 0 &&
1241: (len = buffer_len(&c->extended)) > 0 &&
1242: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1243: debug2("channel %d: rwin %d elen %d euse %d",
1244: c->self, c->remote_window, buffer_len(&c->extended),
1245: c->extended_usage);
1.44 markus 1246: if (len > c->remote_window)
1247: len = c->remote_window;
1248: if (len > c->remote_maxpacket)
1249: len = c->remote_maxpacket;
1250: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1251: packet_put_int(c->remote_id);
1252: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1253: packet_put_string(buffer_ptr(&c->extended), len);
1254: packet_send();
1255: buffer_consume(&c->extended, len);
1256: c->remote_window -= len;
1.93 markus 1257: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1258: }
1.25 markus 1259: }
1.1 deraadt 1260: }
1261:
1.27 markus 1262: /*
1263: * This is called when a packet of type CHANNEL_DATA has just been received.
1264: * The message type has already been consumed, but channel number and data is
1265: * still there.
1266: */
1.1 deraadt 1267:
1.49 markus 1268: void
1.69 markus 1269: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1270: {
1.37 markus 1271: int id;
1.25 markus 1272: char *data;
1.77 markus 1273: u_int data_len;
1.41 markus 1274: Channel *c;
1.25 markus 1275:
1276: /* Get the channel number and verify it. */
1.37 markus 1277: id = packet_get_int();
1.41 markus 1278: c = channel_lookup(id);
1279: if (c == NULL)
1.37 markus 1280: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1281:
1282: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1283: if (c->type != SSH_CHANNEL_OPEN &&
1284: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1285: return;
1286:
1287: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1288: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1289: return;
1290:
1291: /* Get the data. */
1292: data = packet_get_string(&data_len);
1.48 markus 1293: packet_done();
1.41 markus 1294:
1.44 markus 1295: if (compat20){
1296: if (data_len > c->local_maxpacket) {
1297: log("channel %d: rcvd big packet %d, maxpack %d",
1298: c->self, data_len, c->local_maxpacket);
1299: }
1300: if (data_len > c->local_window) {
1301: log("channel %d: rcvd too much data %d, win %d",
1302: c->self, data_len, c->local_window);
1303: xfree(data);
1304: return;
1305: }
1306: c->local_window -= data_len;
1307: }else{
1308: packet_integrity_check(plen, 4 + 4 + data_len, type);
1309: }
1.41 markus 1310: buffer_append(&c->output, data, data_len);
1.25 markus 1311: xfree(data);
1.1 deraadt 1312: }
1.49 markus 1313: void
1.69 markus 1314: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1315: {
1316: int id;
1317: int tcode;
1318: char *data;
1.77 markus 1319: u_int data_len;
1.44 markus 1320: Channel *c;
1321:
1322: /* Get the channel number and verify it. */
1323: id = packet_get_int();
1324: c = channel_lookup(id);
1325:
1326: if (c == NULL)
1327: packet_disconnect("Received extended_data for bad channel %d.", id);
1328: if (c->type != SSH_CHANNEL_OPEN) {
1329: log("channel %d: ext data for non open", id);
1330: return;
1331: }
1332: tcode = packet_get_int();
1333: if (c->efd == -1 ||
1334: c->extended_usage != CHAN_EXTENDED_WRITE ||
1335: tcode != SSH2_EXTENDED_DATA_STDERR) {
1336: log("channel %d: bad ext data", c->self);
1337: return;
1338: }
1339: data = packet_get_string(&data_len);
1.48 markus 1340: packet_done();
1.44 markus 1341: if (data_len > c->local_window) {
1342: log("channel %d: rcvd too much extended_data %d, win %d",
1343: c->self, data_len, c->local_window);
1344: xfree(data);
1345: return;
1346: }
1.70 markus 1347: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1348: c->local_window -= data_len;
1349: buffer_append(&c->extended, data, data_len);
1350: xfree(data);
1351: }
1352:
1.1 deraadt 1353:
1.27 markus 1354: /*
1355: * Returns true if no channel has too much buffered data, and false if one or
1356: * more channel is overfull.
1357: */
1.1 deraadt 1358:
1.49 markus 1359: int
1.25 markus 1360: channel_not_very_much_buffered_data()
1.1 deraadt 1361: {
1.77 markus 1362: u_int i;
1.41 markus 1363: Channel *c;
1.25 markus 1364:
1365: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1366: c = &channels[i];
1367: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1368: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1369: debug("channel %d: big input buffer %d",
1370: c->self, buffer_len(&c->input));
1.25 markus 1371: return 0;
1.41 markus 1372: }
1373: if (buffer_len(&c->output) > packet_get_maxsize()) {
1374: debug("channel %d: big output buffer %d",
1375: c->self, buffer_len(&c->output));
1.25 markus 1376: return 0;
1.41 markus 1377: }
1.25 markus 1378: }
1.1 deraadt 1379: }
1.25 markus 1380: return 1;
1.1 deraadt 1381: }
1382:
1.49 markus 1383: void
1.69 markus 1384: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1385: {
1386: int id;
1387: Channel *c;
1388:
1389: packet_integrity_check(plen, 4, type);
1390:
1391: id = packet_get_int();
1392: c = channel_lookup(id);
1393: if (c == NULL)
1394: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1395: chan_rcvd_ieof(c);
1396: }
1.1 deraadt 1397:
1.49 markus 1398: void
1.69 markus 1399: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1400: {
1.41 markus 1401: int id;
1402: Channel *c;
1.1 deraadt 1403:
1.41 markus 1404: packet_integrity_check(plen, 4, type);
1405:
1406: id = packet_get_int();
1407: c = channel_lookup(id);
1408: if (c == NULL)
1409: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1410:
1411: /*
1412: * Send a confirmation that we have closed the channel and no more
1413: * data is coming for it.
1414: */
1.25 markus 1415: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1416: packet_put_int(c->remote_id);
1.25 markus 1417: packet_send();
1418:
1.27 markus 1419: /*
1420: * If the channel is in closed state, we have sent a close request,
1421: * and the other side will eventually respond with a confirmation.
1422: * Thus, we cannot free the channel here, because then there would be
1423: * no-one to receive the confirmation. The channel gets freed when
1424: * the confirmation arrives.
1425: */
1.41 markus 1426: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1427: /*
1428: * Not a closed channel - mark it as draining, which will
1429: * cause it to be freed later.
1430: */
1.41 markus 1431: buffer_consume(&c->input, buffer_len(&c->input));
1432: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1433: }
1.1 deraadt 1434: }
1435:
1.41 markus 1436: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1437: void
1.69 markus 1438: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1439: {
1440: int id = packet_get_int();
1441: Channel *c = channel_lookup(id);
1442: packet_integrity_check(plen, 4, type);
1443: if (c == NULL)
1444: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1445: chan_rcvd_oclose(c);
1446: }
1.1 deraadt 1447:
1.49 markus 1448: void
1.69 markus 1449: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1450: {
1.41 markus 1451: int id = packet_get_int();
1452: Channel *c = channel_lookup(id);
1.1 deraadt 1453:
1.48 markus 1454: packet_done();
1.41 markus 1455: if (c == NULL)
1456: packet_disconnect("Received close confirmation for "
1457: "out-of-range channel %d.", id);
1458: if (c->type != SSH_CHANNEL_CLOSED)
1459: packet_disconnect("Received close confirmation for "
1460: "non-closed channel %d (type %d).", id, c->type);
1461: channel_free(c->self);
1.1 deraadt 1462: }
1463:
1.49 markus 1464: void
1.69 markus 1465: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1466: {
1.41 markus 1467: int id, remote_id;
1468: Channel *c;
1.1 deraadt 1469:
1.44 markus 1470: if (!compat20)
1471: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1472:
1.41 markus 1473: id = packet_get_int();
1474: c = channel_lookup(id);
1.25 markus 1475:
1.41 markus 1476: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1477: packet_disconnect("Received open confirmation for "
1478: "non-opening channel %d.", id);
1479: remote_id = packet_get_int();
1.27 markus 1480: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1481: c->remote_id = remote_id;
1482: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1483:
1484: if (compat20) {
1485: c->remote_window = packet_get_int();
1486: c->remote_maxpacket = packet_get_int();
1.48 markus 1487: packet_done();
1.44 markus 1488: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1489: debug2("callback start");
1.44 markus 1490: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1491: debug2("callback done");
1.44 markus 1492: }
1493: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1494: c->remote_window, c->remote_maxpacket);
1495: }
1.1 deraadt 1496: }
1497:
1.49 markus 1498: void
1.69 markus 1499: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1500: {
1.86 markus 1501: int id, reason;
1502: char *msg = NULL, *lang = NULL;
1.41 markus 1503: Channel *c;
1504:
1.44 markus 1505: if (!compat20)
1506: packet_integrity_check(plen, 4, type);
1.41 markus 1507:
1508: id = packet_get_int();
1509: c = channel_lookup(id);
1.25 markus 1510:
1.41 markus 1511: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1512: packet_disconnect("Received open failure for "
1513: "non-opening channel %d.", id);
1.44 markus 1514: if (compat20) {
1.86 markus 1515: reason = packet_get_int();
1516: if (packet_remaining() > 0) {
1517: msg = packet_get_string(NULL);
1518: lang = packet_get_string(NULL);
1519: }
1.48 markus 1520: packet_done();
1.86 markus 1521: log("channel_open_failure: %d: reason %d %s", id,
1522: reason, msg ? msg : "<no additional info>");
1523: if (msg != NULL)
1524: xfree(msg);
1525: if (lang != NULL)
1526: xfree(lang);
1.44 markus 1527: }
1.25 markus 1528: /* Free the channel. This will also close the socket. */
1.41 markus 1529: channel_free(id);
1.1 deraadt 1530: }
1531:
1.44 markus 1532: void
1.69 markus 1533: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1534: {
1535: int id;
1536: Channel *c;
1537:
1538: id = packet_get_int();
1539: c = channel_lookup(id);
1540:
1541: if (c == NULL ||
1542: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1543: packet_disconnect("Received request for "
1544: "non-open channel %d.", id);
1545: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1546: debug2("callback start");
1.44 markus 1547: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1548: debug2("callback done");
1.44 markus 1549: } else {
1550: char *service = packet_get_string(NULL);
1.94 markus 1551: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1552: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1553: xfree(service);
1554: }
1555: }
1556:
1.49 markus 1557: void
1.69 markus 1558: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1559: {
1560: Channel *c;
1561: int id, adjust;
1562:
1563: if (!compat20)
1564: return;
1565:
1566: /* Get the channel number and verify it. */
1567: id = packet_get_int();
1568: c = channel_lookup(id);
1569:
1570: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1571: log("Received window adjust for "
1572: "non-open channel %d.", id);
1573: return;
1574: }
1575: adjust = packet_get_int();
1.48 markus 1576: packet_done();
1.70 markus 1577: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1578: c->remote_window += adjust;
1579: }
1580:
1.27 markus 1581: /*
1582: * Stops listening for channels, and removes any unix domain sockets that we
1583: * might have.
1584: */
1.1 deraadt 1585:
1.49 markus 1586: void
1.25 markus 1587: channel_stop_listening()
1.1 deraadt 1588: {
1.25 markus 1589: int i;
1590: for (i = 0; i < channels_alloc; i++) {
1591: switch (channels[i].type) {
1592: case SSH_CHANNEL_AUTH_SOCKET:
1593: close(channels[i].sock);
1.76 markus 1594: unlink(channels[i].path);
1.25 markus 1595: channel_free(i);
1596: break;
1597: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1598: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1599: case SSH_CHANNEL_X11_LISTENER:
1600: close(channels[i].sock);
1601: channel_free(i);
1602: break;
1603: default:
1604: break;
1605: }
1.1 deraadt 1606: }
1607: }
1608:
1.27 markus 1609: /*
1.52 markus 1610: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1611: * descriptors after a fork.
1612: */
1.1 deraadt 1613:
1.49 markus 1614: void
1.25 markus 1615: channel_close_all()
1.1 deraadt 1616: {
1.25 markus 1617: int i;
1.52 markus 1618: for (i = 0; i < channels_alloc; i++)
1.25 markus 1619: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1620: channel_close_fds(&channels[i]);
1.1 deraadt 1621: }
1622:
1623: /* Returns true if any channel is still open. */
1624:
1.49 markus 1625: int
1.25 markus 1626: channel_still_open()
1.1 deraadt 1627: {
1.77 markus 1628: u_int i;
1.25 markus 1629: for (i = 0; i < channels_alloc; i++)
1630: switch (channels[i].type) {
1631: case SSH_CHANNEL_FREE:
1632: case SSH_CHANNEL_X11_LISTENER:
1633: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1634: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1635: case SSH_CHANNEL_CLOSED:
1636: case SSH_CHANNEL_AUTH_SOCKET:
1.103 ! markus 1637: case SSH_CHANNEL_DYNAMIC:
1.75 markus 1638: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1639: continue;
1.44 markus 1640: case SSH_CHANNEL_LARVAL:
1641: if (!compat20)
1642: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1643: continue;
1.25 markus 1644: case SSH_CHANNEL_OPENING:
1645: case SSH_CHANNEL_OPEN:
1646: case SSH_CHANNEL_X11_OPEN:
1647: return 1;
1648: case SSH_CHANNEL_INPUT_DRAINING:
1649: case SSH_CHANNEL_OUTPUT_DRAINING:
1650: if (!compat13)
1651: fatal("cannot happen: OUT_DRAIN");
1652: return 1;
1653: default:
1654: fatal("channel_still_open: bad channel type %d", channels[i].type);
1655: /* NOTREACHED */
1656: }
1657: return 0;
1.1 deraadt 1658: }
1659:
1.27 markus 1660: /*
1661: * Returns a message describing the currently open forwarded connections,
1662: * suitable for sending to the client. The message contains crlf pairs for
1663: * newlines.
1664: */
1.1 deraadt 1665:
1.25 markus 1666: char *
1667: channel_open_message()
1.1 deraadt 1668: {
1.25 markus 1669: Buffer buffer;
1670: int i;
1671: char buf[512], *cp;
1672:
1673: buffer_init(&buffer);
1674: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1675: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1676: for (i = 0; i < channels_alloc; i++) {
1677: Channel *c = &channels[i];
1678: switch (c->type) {
1679: case SSH_CHANNEL_FREE:
1680: case SSH_CHANNEL_X11_LISTENER:
1681: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1682: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1683: case SSH_CHANNEL_CLOSED:
1684: case SSH_CHANNEL_AUTH_SOCKET:
1685: continue;
1.44 markus 1686: case SSH_CHANNEL_LARVAL:
1.25 markus 1687: case SSH_CHANNEL_OPENING:
1.75 markus 1688: case SSH_CHANNEL_CONNECTING:
1.103 ! markus 1689: case SSH_CHANNEL_DYNAMIC:
1.25 markus 1690: case SSH_CHANNEL_OPEN:
1691: case SSH_CHANNEL_X11_OPEN:
1692: case SSH_CHANNEL_INPUT_DRAINING:
1693: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1694: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1695: c->self, c->remote_name,
1696: c->type, c->remote_id,
1697: c->istate, buffer_len(&c->input),
1.41 markus 1698: c->ostate, buffer_len(&c->output),
1699: c->rfd, c->wfd);
1.25 markus 1700: buffer_append(&buffer, buf, strlen(buf));
1701: continue;
1702: default:
1.41 markus 1703: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1704: /* NOTREACHED */
1705: }
1706: }
1707: buffer_append(&buffer, "\0", 1);
1708: cp = xstrdup(buffer_ptr(&buffer));
1709: buffer_free(&buffer);
1710: return cp;
1.1 deraadt 1711: }
1712:
1.27 markus 1713: /*
1714: * Initiate forwarding of connections to local port "port" through the secure
1715: * channel to host:port from remote side.
1716: */
1.87 markus 1717: int
1.73 markus 1718: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1719: u_short port_to_connect, int gateway_ports)
1720: {
1.87 markus 1721: return channel_request_forwarding(
1.73 markus 1722: NULL, listen_port,
1723: host_to_connect, port_to_connect,
1724: gateway_ports, /*remote_fwd*/ 0);
1725: }
1.1 deraadt 1726:
1.73 markus 1727: /*
1728: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1729: * (SSH_CHANNEL_RPORT_LISTENER).
1730: */
1.87 markus 1731: int
1.73 markus 1732: channel_request_forwarding(
1733: const char *listen_address, u_short listen_port,
1734: const char *host_to_connect, u_short port_to_connect,
1735: int gateway_ports, int remote_fwd)
1.25 markus 1736: {
1.73 markus 1737: int success, ch, sock, on = 1, ctype;
1.35 markus 1738: struct addrinfo hints, *ai, *aitop;
1739: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1740: const char *host;
1.28 markus 1741: struct linger linger;
1.25 markus 1742:
1.87 markus 1743: success = 0;
1744:
1.73 markus 1745: if (remote_fwd) {
1746: host = listen_address;
1.89 stevesk 1747: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1748: } else {
1749: host = host_to_connect;
1750: ctype =SSH_CHANNEL_PORT_LISTENER;
1751: }
1752:
1.87 markus 1753: if (strlen(host) > sizeof(channels[0].path) - 1) {
1754: error("Forward host name too long.");
1755: return success;
1756: }
1.25 markus 1757:
1.73 markus 1758: /* XXX listen_address is currently ignored */
1.28 markus 1759: /*
1.35 markus 1760: * getaddrinfo returns a loopback address if the hostname is
1761: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1762: */
1.35 markus 1763: memset(&hints, 0, sizeof(hints));
1764: hints.ai_family = IPv4or6;
1765: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1766: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1767: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1768: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1769: packet_disconnect("getaddrinfo: fatal error");
1770:
1771: for (ai = aitop; ai; ai = ai->ai_next) {
1772: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1773: continue;
1774: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1775: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1776: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1777: continue;
1778: }
1779: /* Create a port to listen for the host. */
1780: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1781: if (sock < 0) {
1782: /* this is no error since kernel may not support ipv6 */
1783: verbose("socket: %.100s", strerror(errno));
1784: continue;
1785: }
1786: /*
1787: * Set socket options. We would like the socket to disappear
1788: * as soon as it has been closed for whatever reason.
1789: */
1790: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1791: linger.l_onoff = 1;
1792: linger.l_linger = 5;
1793: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1794: debug("Local forwarding listening on %s port %s.", ntop, strport);
1795:
1796: /* Bind the socket to the address. */
1797: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1798: /* address can be in use ipv6 address is already bound */
1799: verbose("bind: %.100s", strerror(errno));
1800: close(sock);
1801: continue;
1802: }
1803: /* Start listening for connections on the socket. */
1804: if (listen(sock, 5) < 0) {
1805: error("listen: %.100s", strerror(errno));
1806: close(sock);
1807: continue;
1808: }
1809: /* Allocate a channel number for the socket. */
1.73 markus 1810: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1811: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1812: 0, xstrdup("port listener"), 1);
1.35 markus 1813: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1814: channels[ch].host_port = port_to_connect;
1815: channels[ch].listening_port = listen_port;
1.35 markus 1816: success = 1;
1817: }
1818: if (success == 0)
1.87 markus 1819: error("channel_request_forwarding: cannot listen to port: %d",
1820: listen_port);
1.35 markus 1821: freeaddrinfo(aitop);
1.87 markus 1822: return success;
1.25 markus 1823: }
1.1 deraadt 1824:
1.27 markus 1825: /*
1826: * Initiate forwarding of connections to port "port" on remote host through
1827: * the secure channel to host:port from local side.
1828: */
1.1 deraadt 1829:
1.49 markus 1830: void
1.73 markus 1831: channel_request_remote_forwarding(u_short listen_port,
1832: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1833: {
1.73 markus 1834: int payload_len, type, success = 0;
1835:
1.25 markus 1836: /* Record locally that connection to this host/port is permitted. */
1837: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1838: fatal("channel_request_remote_forwarding: too many forwards");
1839:
1840: /* Send the forward request to the remote side. */
1.44 markus 1841: if (compat20) {
1842: const char *address_to_bind = "0.0.0.0";
1843: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1844: packet_put_cstring("tcpip-forward");
1845: packet_put_char(0); /* boolean: want reply */
1846: packet_put_cstring(address_to_bind);
1847: packet_put_int(listen_port);
1.73 markus 1848: packet_send();
1849: packet_write_wait();
1850: /* Assume that server accepts the request */
1851: success = 1;
1.44 markus 1852: } else {
1853: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1854: packet_put_int(listen_port);
1855: packet_put_cstring(host_to_connect);
1.44 markus 1856: packet_put_int(port_to_connect);
1857: packet_send();
1858: packet_write_wait();
1.73 markus 1859:
1860: /* Wait for response from the remote side. */
1861: type = packet_read(&payload_len);
1862: switch (type) {
1863: case SSH_SMSG_SUCCESS:
1864: success = 1;
1865: break;
1866: case SSH_SMSG_FAILURE:
1867: log("Warning: Server denied remote port forwarding.");
1868: break;
1869: default:
1870: /* Unknown packet */
1871: packet_disconnect("Protocol error for port forward request:"
1872: "received packet type %d.", type);
1873: }
1874: }
1875: if (success) {
1876: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1877: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1878: permitted_opens[num_permitted_opens].listen_port = listen_port;
1879: num_permitted_opens++;
1.44 markus 1880: }
1.1 deraadt 1881: }
1882:
1.27 markus 1883: /*
1884: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1885: * listening for the port, and sends back a success reply (or disconnect
1886: * message if there was an error). This never returns if there was an error.
1887: */
1.1 deraadt 1888:
1.49 markus 1889: void
1.56 markus 1890: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1891: {
1.31 markus 1892: u_short port, host_port;
1.25 markus 1893: char *hostname;
1.1 deraadt 1894:
1.25 markus 1895: /* Get arguments from the packet. */
1896: port = packet_get_int();
1897: hostname = packet_get_string(NULL);
1898: host_port = packet_get_int();
1899:
1.27 markus 1900: /*
1901: * Check that an unprivileged user is not trying to forward a
1902: * privileged port.
1903: */
1.25 markus 1904: if (port < IPPORT_RESERVED && !is_root)
1905: packet_disconnect("Requested forwarding of port %d but user is not root.",
1906: port);
1.73 markus 1907: /* Initiate forwarding */
1.56 markus 1908: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1909:
1910: /* Free the argument string. */
1911: xfree(hostname);
1.1 deraadt 1912: }
1913:
1.99 markus 1914: /*
1915: * Permits opening to any host/port if permitted_opens[] is empty. This is
1916: * usually called by the server, because the user could connect to any port
1917: * anyway, and the server has no way to know but to trust the client anyway.
1918: */
1919: void
1920: channel_permit_all_opens()
1921: {
1922: if (num_permitted_opens == 0)
1923: all_opens_permitted = 1;
1924: }
1925:
1.101 markus 1926: void
1.99 markus 1927: channel_add_permitted_opens(char *host, int port)
1928: {
1929: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1930: fatal("channel_request_remote_forwarding: too many forwards");
1931: debug("allow port forwarding to host %s port %d", host, port);
1932:
1933: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
1934: permitted_opens[num_permitted_opens].port_to_connect = port;
1935: num_permitted_opens++;
1936:
1937: all_opens_permitted = 0;
1938: }
1939:
1.101 markus 1940: void
1.99 markus 1941: channel_clear_permitted_opens(void)
1942: {
1943: int i;
1944:
1945: for (i = 0; i < num_permitted_opens; i++)
1946: xfree(permitted_opens[i].host_to_connect);
1947: num_permitted_opens = 0;
1948:
1949: }
1950:
1951:
1952: /* return socket to remote host, port */
1.41 markus 1953: int
1.99 markus 1954: connect_to(const char *host, u_short port)
1.41 markus 1955: {
1956: struct addrinfo hints, *ai, *aitop;
1957: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1958: int gaierr;
1959: int sock = -1;
1960:
1961: memset(&hints, 0, sizeof(hints));
1962: hints.ai_family = IPv4or6;
1963: hints.ai_socktype = SOCK_STREAM;
1.99 markus 1964: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 1965: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 1966: error("connect_to %.100s: unknown host (%s)", host,
1967: gai_strerror(gaierr));
1.41 markus 1968: return -1;
1969: }
1970: for (ai = aitop; ai; ai = ai->ai_next) {
1971: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1972: continue;
1973: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1974: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 1975: error("connect_to: getnameinfo failed");
1.41 markus 1976: continue;
1977: }
1978: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1979: if (sock < 0) {
1980: error("socket: %.100s", strerror(errno));
1981: continue;
1982: }
1.80 markus 1983: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1984: fatal("connect_to: F_SETFL: %s", strerror(errno));
1985: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1986: errno != EINPROGRESS) {
1.99 markus 1987: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 1988: strerror(errno));
1989: close(sock);
1.89 stevesk 1990: continue; /* fail -- try next */
1.41 markus 1991: }
1992: break; /* success */
1993:
1994: }
1995: freeaddrinfo(aitop);
1996: if (!ai) {
1.99 markus 1997: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 1998: return -1;
1999: }
2000: /* success */
2001: return sock;
2002: }
1.99 markus 2003:
1.73 markus 2004: int
2005: channel_connect_by_listen_adress(u_short listen_port)
2006: {
2007: int i;
1.99 markus 2008:
1.73 markus 2009: for (i = 0; i < num_permitted_opens; i++)
2010: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2011: return connect_to(
1.73 markus 2012: permitted_opens[i].host_to_connect,
2013: permitted_opens[i].port_to_connect);
1.74 markus 2014: error("WARNING: Server requests forwarding for unknown listen_port %d",
2015: listen_port);
1.73 markus 2016: return -1;
2017: }
2018:
1.99 markus 2019: /* Check if connecting to that port is permitted and connect. */
2020: int
2021: channel_connect_to(const char *host, u_short port)
2022: {
2023: int i, permit;
2024:
2025: permit = all_opens_permitted;
2026: if (!permit) {
2027: for (i = 0; i < num_permitted_opens; i++)
2028: if (permitted_opens[i].port_to_connect == port &&
2029: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2030: permit = 1;
2031:
2032: }
2033: if (!permit) {
2034: log("Received request to connect to host %.100s port %d, "
2035: "but the request was denied.", host, port);
2036: return -1;
2037: }
2038: return connect_to(host, port);
2039: }
2040:
1.27 markus 2041: /*
2042: * This is called after receiving PORT_OPEN message. This attempts to
2043: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2044: * or CHANNEL_OPEN_FAILURE.
2045: */
1.1 deraadt 2046:
1.49 markus 2047: void
1.69 markus 2048: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2049: {
1.31 markus 2050: u_short host_port;
1.25 markus 2051: char *host, *originator_string;
1.99 markus 2052: int remote_channel, sock = -1, newch;
1.25 markus 2053:
2054: remote_channel = packet_get_int();
1.99 markus 2055: host = packet_get_string(NULL);
1.25 markus 2056: host_port = packet_get_int();
2057:
1.29 markus 2058: if (have_hostname_in_open) {
1.99 markus 2059: originator_string = packet_get_string(NULL);
1.29 markus 2060: } else {
1.25 markus 2061: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 2062: }
1.99 markus 2063: packet_done();
2064: sock = channel_connect_to(host, host_port);
2065: if (sock != -1) {
1.75 markus 2066: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
2067: sock, originator_string);
1.41 markus 2068: channels[newch].remote_id = remote_channel;
2069:
1.99 markus 2070: /*XXX delay answer? */
1.41 markus 2071: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2072: packet_put_int(remote_channel);
2073: packet_put_int(newch);
2074: packet_send();
2075: } else {
2076: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2077: packet_put_int(remote_channel);
2078: packet_send();
1.25 markus 2079: }
2080: xfree(host);
1.1 deraadt 2081: }
2082:
1.27 markus 2083: /*
2084: * Creates an internet domain socket for listening for X11 connections.
2085: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2086: * occurs.
2087: */
1.1 deraadt 2088:
1.35 markus 2089: #define NUM_SOCKS 10
2090:
1.25 markus 2091: char *
1.33 markus 2092: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2093: {
1.31 markus 2094: int display_number, sock;
2095: u_short port;
1.35 markus 2096: struct addrinfo hints, *ai, *aitop;
2097: char strport[NI_MAXSERV];
2098: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2099: char display[512];
1.25 markus 2100: char hostname[MAXHOSTNAMELEN];
2101:
1.33 markus 2102: for (display_number = x11_display_offset;
1.25 markus 2103: display_number < MAX_DISPLAYS;
2104: display_number++) {
2105: port = 6000 + display_number;
1.35 markus 2106: memset(&hints, 0, sizeof(hints));
2107: hints.ai_family = IPv4or6;
1.36 markus 2108: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2109: hints.ai_socktype = SOCK_STREAM;
2110: snprintf(strport, sizeof strport, "%d", port);
2111: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2112: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2113: return NULL;
2114: }
1.35 markus 2115: for (ai = aitop; ai; ai = ai->ai_next) {
2116: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2117: continue;
2118: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2119: if (sock < 0) {
2120: error("socket: %.100s", strerror(errno));
2121: return NULL;
2122: }
2123: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2124: debug("bind port %d: %.100s", port, strerror(errno));
2125: shutdown(sock, SHUT_RDWR);
2126: close(sock);
2127: for (n = 0; n < num_socks; n++) {
2128: shutdown(socks[n], SHUT_RDWR);
2129: close(socks[n]);
2130: }
2131: num_socks = 0;
2132: break;
2133: }
2134: socks[num_socks++] = sock;
2135: if (num_socks == NUM_SOCKS)
2136: break;
1.25 markus 2137: }
1.83 stevesk 2138: freeaddrinfo(aitop);
1.35 markus 2139: if (num_socks > 0)
2140: break;
1.25 markus 2141: }
2142: if (display_number >= MAX_DISPLAYS) {
2143: error("Failed to allocate internet-domain X11 display socket.");
2144: return NULL;
2145: }
2146: /* Start listening for connections on the socket. */
1.35 markus 2147: for (n = 0; n < num_socks; n++) {
2148: sock = socks[n];
2149: if (listen(sock, 5) < 0) {
2150: error("listen: %.100s", strerror(errno));
2151: shutdown(sock, SHUT_RDWR);
2152: close(sock);
2153: return NULL;
2154: }
1.25 markus 2155: }
1.35 markus 2156:
1.25 markus 2157: /* Set up a suitable value for the DISPLAY variable. */
2158: if (gethostname(hostname, sizeof(hostname)) < 0)
2159: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2160: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2161: display_number, screen_number);
2162:
1.35 markus 2163: /* Allocate a channel for each socket. */
2164: for (n = 0; n < num_socks; n++) {
2165: sock = socks[n];
1.51 markus 2166: (void) channel_new("x11 listener",
2167: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2168: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2169: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2170: }
1.1 deraadt 2171:
1.25 markus 2172: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2173: return xstrdup(display);
1.1 deraadt 2174: }
2175:
2176: #ifndef X_UNIX_PATH
2177: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2178: #endif
2179:
2180: static
2181: int
1.77 markus 2182: connect_local_xsocket(u_int dnr)
1.1 deraadt 2183: {
1.25 markus 2184: static const char *const x_sockets[] = {
2185: X_UNIX_PATH "%u",
2186: "/var/X/.X11-unix/X" "%u",
2187: "/usr/spool/sockets/X11/" "%u",
2188: NULL
2189: };
2190: int sock;
2191: struct sockaddr_un addr;
2192: const char *const * path;
2193:
2194: for (path = x_sockets; *path; ++path) {
2195: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2196: if (sock < 0)
2197: error("socket: %.100s", strerror(errno));
2198: memset(&addr, 0, sizeof(addr));
2199: addr.sun_family = AF_UNIX;
2200: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2201: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2202: return sock;
2203: close(sock);
2204: }
2205: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2206: return -1;
1.1 deraadt 2207: }
2208:
1.51 markus 2209: int
2210: x11_connect_display(void)
1.1 deraadt 2211: {
1.51 markus 2212: int display_number, sock = 0;
1.25 markus 2213: const char *display;
1.51 markus 2214: char buf[1024], *cp;
1.35 markus 2215: struct addrinfo hints, *ai, *aitop;
2216: char strport[NI_MAXSERV];
2217: int gaierr;
1.25 markus 2218:
2219: /* Try to open a socket for the local X server. */
2220: display = getenv("DISPLAY");
2221: if (!display) {
2222: error("DISPLAY not set.");
1.51 markus 2223: return -1;
1.25 markus 2224: }
1.27 markus 2225: /*
2226: * Now we decode the value of the DISPLAY variable and make a
2227: * connection to the real X server.
2228: */
2229:
2230: /*
2231: * Check if it is a unix domain socket. Unix domain displays are in
2232: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2233: */
1.25 markus 2234: if (strncmp(display, "unix:", 5) == 0 ||
2235: display[0] == ':') {
2236: /* Connect to the unix domain socket. */
2237: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2238: error("Could not parse display number from DISPLAY: %.100s",
2239: display);
1.51 markus 2240: return -1;
1.25 markus 2241: }
2242: /* Create a socket. */
2243: sock = connect_local_xsocket(display_number);
2244: if (sock < 0)
1.51 markus 2245: return -1;
1.25 markus 2246:
2247: /* OK, we now have a connection to the display. */
1.51 markus 2248: return sock;
1.25 markus 2249: }
1.27 markus 2250: /*
2251: * Connect to an inet socket. The DISPLAY value is supposedly
2252: * hostname:d[.s], where hostname may also be numeric IP address.
2253: */
1.25 markus 2254: strncpy(buf, display, sizeof(buf));
2255: buf[sizeof(buf) - 1] = 0;
2256: cp = strchr(buf, ':');
2257: if (!cp) {
2258: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2259: return -1;
1.25 markus 2260: }
2261: *cp = 0;
1.27 markus 2262: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2263: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2264: error("Could not parse display number from DISPLAY: %.100s",
2265: display);
1.51 markus 2266: return -1;
1.25 markus 2267: }
1.35 markus 2268:
2269: /* Look up the host address */
2270: memset(&hints, 0, sizeof(hints));
2271: hints.ai_family = IPv4or6;
2272: hints.ai_socktype = SOCK_STREAM;
2273: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2274: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2275: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2276: return -1;
1.25 markus 2277: }
1.35 markus 2278: for (ai = aitop; ai; ai = ai->ai_next) {
2279: /* Create a socket. */
2280: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2281: if (sock < 0) {
2282: debug("socket: %.100s", strerror(errno));
1.41 markus 2283: continue;
2284: }
2285: /* Connect it to the display. */
2286: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2287: debug("connect %.100s port %d: %.100s", buf,
2288: 6000 + display_number, strerror(errno));
2289: close(sock);
2290: continue;
2291: }
2292: /* Success */
2293: break;
1.35 markus 2294: }
2295: freeaddrinfo(aitop);
2296: if (!ai) {
1.49 markus 2297: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2298: strerror(errno));
1.51 markus 2299: return -1;
1.25 markus 2300: }
1.51 markus 2301: return sock;
2302: }
2303:
2304: /*
2305: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2306: * the remote channel number. We should do whatever we want, and respond
2307: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2308: */
2309:
2310: void
1.69 markus 2311: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2312: {
2313: int remote_channel, sock = 0, newch;
2314: char *remote_host;
1.77 markus 2315: u_int remote_len;
1.25 markus 2316:
1.51 markus 2317: /* Get remote channel number. */
2318: remote_channel = packet_get_int();
2319:
2320: /* Get remote originator name. */
2321: if (have_hostname_in_open) {
2322: remote_host = packet_get_string(&remote_len);
2323: remote_len += 4;
2324: } else {
2325: remote_host = xstrdup("unknown (remote did not supply name)");
2326: remote_len = 0;
2327: }
1.25 markus 2328:
1.51 markus 2329: debug("Received X11 open request.");
2330: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2331:
1.51 markus 2332: /* Obtain a connection to the real X display. */
2333: sock = x11_connect_display();
2334: if (sock == -1) {
2335: /* Send refusal to the remote host. */
2336: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2337: packet_put_int(remote_channel);
2338: packet_send();
2339: } else {
2340: /* Allocate a channel for this connection. */
2341: newch = channel_allocate(
2342: (x11_saved_proto == NULL) ?
2343: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2344: sock, remote_host);
2345: channels[newch].remote_id = remote_channel;
1.25 markus 2346:
1.51 markus 2347: /* Send a confirmation to the remote host. */
2348: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2349: packet_put_int(remote_channel);
2350: packet_put_int(newch);
2351: packet_send();
2352: }
1.72 markus 2353: }
2354:
2355: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2356: void
2357: deny_input_open(int type, int plen, void *ctxt)
2358: {
2359: int rchan = packet_get_int();
2360: switch(type){
2361: case SSH_SMSG_AGENT_OPEN:
2362: error("Warning: ssh server tried agent forwarding.");
2363: break;
2364: case SSH_SMSG_X11_OPEN:
2365: error("Warning: ssh server tried X11 forwarding.");
2366: break;
2367: default:
2368: error("deny_input_open: type %d plen %d", type, plen);
2369: break;
2370: }
2371: error("Warning: this is probably a break in attempt by a malicious server.");
2372: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2373: packet_put_int(rchan);
2374: packet_send();
1.1 deraadt 2375: }
2376:
1.27 markus 2377: /*
2378: * Requests forwarding of X11 connections, generates fake authentication
2379: * data, and enables authentication spoofing.
2380: */
1.1 deraadt 2381:
1.49 markus 2382: void
1.51 markus 2383: x11_request_forwarding_with_spoofing(int client_session_id,
2384: const char *proto, const char *data)
1.1 deraadt 2385: {
1.77 markus 2386: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2387: u_int i, value, len;
1.25 markus 2388: char *new_data;
2389: int screen_number;
2390: const char *cp;
2391: u_int32_t rand = 0;
2392:
2393: cp = getenv("DISPLAY");
2394: if (cp)
2395: cp = strchr(cp, ':');
2396: if (cp)
2397: cp = strchr(cp, '.');
2398: if (cp)
2399: screen_number = atoi(cp + 1);
2400: else
2401: screen_number = 0;
2402:
2403: /* Save protocol name. */
2404: x11_saved_proto = xstrdup(proto);
2405:
1.27 markus 2406: /*
2407: * Extract real authentication data and generate fake data of the
2408: * same length.
2409: */
1.25 markus 2410: x11_saved_data = xmalloc(data_len);
2411: x11_fake_data = xmalloc(data_len);
2412: for (i = 0; i < data_len; i++) {
2413: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2414: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2415: if (i % 4 == 0)
2416: rand = arc4random();
2417: x11_saved_data[i] = value;
2418: x11_fake_data[i] = rand & 0xff;
2419: rand >>= 8;
2420: }
2421: x11_saved_data_len = data_len;
2422: x11_fake_data_len = data_len;
2423:
2424: /* Convert the fake data into hex. */
1.90 markus 2425: len = 2 * data_len + 1;
2426: new_data = xmalloc(len);
1.25 markus 2427: for (i = 0; i < data_len; i++)
1.90 markus 2428: snprintf(new_data + 2 * i, len - 2 * i,
2429: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2430:
2431: /* Send the request packet. */
1.51 markus 2432: if (compat20) {
2433: channel_request_start(client_session_id, "x11-req", 0);
2434: packet_put_char(0); /* XXX bool single connection */
2435: } else {
2436: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2437: }
2438: packet_put_cstring(proto);
2439: packet_put_cstring(new_data);
1.25 markus 2440: packet_put_int(screen_number);
2441: packet_send();
2442: packet_write_wait();
2443: xfree(new_data);
1.1 deraadt 2444: }
2445:
2446: /* Sends a message to the server to request authentication fd forwarding. */
2447:
1.49 markus 2448: void
1.25 markus 2449: auth_request_forwarding()
1.1 deraadt 2450: {
1.25 markus 2451: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2452: packet_send();
2453: packet_write_wait();
1.1 deraadt 2454: }
2455:
1.27 markus 2456: /*
2457: * Returns the name of the forwarded authentication socket. Returns NULL if
2458: * there is no forwarded authentication socket. The returned value points to
2459: * a static buffer.
2460: */
1.1 deraadt 2461:
1.25 markus 2462: char *
2463: auth_get_socket_name()
1.1 deraadt 2464: {
1.25 markus 2465: return channel_forwarded_auth_socket_name;
1.1 deraadt 2466: }
2467:
1.12 markus 2468: /* removes the agent forwarding socket */
2469:
1.49 markus 2470: void
1.25 markus 2471: cleanup_socket(void)
2472: {
1.78 markus 2473: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2474: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2475: }
2476:
1.27 markus 2477: /*
1.59 markus 2478: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2479: * This starts forwarding authentication requests.
2480: */
1.1 deraadt 2481:
1.59 markus 2482: int
1.25 markus 2483: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2484: {
1.25 markus 2485: int sock, newch;
2486: struct sockaddr_un sunaddr;
2487:
2488: if (auth_get_socket_name() != NULL)
2489: fatal("Protocol error: authentication forwarding requested twice.");
2490:
2491: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2492: temporarily_use_uid(pw);
1.25 markus 2493:
2494: /* Allocate a buffer for the socket name, and format the name. */
2495: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2496: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2497: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2498:
2499: /* Create private directory for socket */
1.59 markus 2500: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2501: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2502: strerror(errno));
2503: restore_uid();
2504: xfree(channel_forwarded_auth_socket_name);
2505: xfree(channel_forwarded_auth_socket_dir);
2506: channel_forwarded_auth_socket_name = NULL;
2507: channel_forwarded_auth_socket_dir = NULL;
2508: return 0;
2509: }
1.25 markus 2510: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2511: channel_forwarded_auth_socket_dir, (int) getpid());
2512:
2513: if (atexit(cleanup_socket) < 0) {
2514: int saved = errno;
2515: cleanup_socket();
2516: packet_disconnect("socket: %.100s", strerror(saved));
2517: }
2518: /* Create the socket. */
2519: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2520: if (sock < 0)
2521: packet_disconnect("socket: %.100s", strerror(errno));
2522:
2523: /* Bind it to the name. */
2524: memset(&sunaddr, 0, sizeof(sunaddr));
2525: sunaddr.sun_family = AF_UNIX;
2526: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2527: sizeof(sunaddr.sun_path));
2528:
2529: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2530: packet_disconnect("bind: %.100s", strerror(errno));
2531:
2532: /* Restore the privileged uid. */
2533: restore_uid();
2534:
2535: /* Start listening on the socket. */
2536: if (listen(sock, 5) < 0)
2537: packet_disconnect("listen: %.100s", strerror(errno));
2538:
2539: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2540: newch = channel_new("auth socket",
2541: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2542: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2543: 0, xstrdup("auth socket"), 1);
2544:
1.32 deraadt 2545: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2546: sizeof(channels[newch].path));
1.59 markus 2547: return 1;
1.1 deraadt 2548: }
2549:
2550: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2551:
1.49 markus 2552: void
1.69 markus 2553: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2554: {
1.25 markus 2555: int remch, sock, newch;
2556: char *dummyname;
1.41 markus 2557:
2558: packet_integrity_check(plen, 4, type);
1.25 markus 2559:
2560: /* Read the remote channel number from the message. */
2561: remch = packet_get_int();
2562:
1.27 markus 2563: /*
2564: * Get a connection to the local authentication agent (this may again
2565: * get forwarded).
2566: */
1.25 markus 2567: sock = ssh_get_authentication_socket();
2568:
1.27 markus 2569: /*
2570: * If we could not connect the agent, send an error message back to
2571: * the server. This should never happen unless the agent dies,
2572: * because authentication forwarding is only enabled if we have an
2573: * agent.
2574: */
1.25 markus 2575: if (sock < 0) {
2576: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2577: packet_put_int(remch);
2578: packet_send();
2579: return;
2580: }
2581: debug("Forwarding authentication connection.");
1.1 deraadt 2582:
1.27 markus 2583: /*
2584: * Dummy host name. This will be freed when the channel is freed; it
2585: * will still be valid in the packet_put_string below since the
2586: * channel cannot yet be freed at that point.
2587: */
1.25 markus 2588: dummyname = xstrdup("authentication agent connection");
2589:
2590: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2591: channels[newch].remote_id = remch;
2592:
2593: /* Send a confirmation to the remote host. */
2594: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2595: packet_put_int(remch);
2596: packet_put_int(newch);
1.44 markus 2597: packet_send();
2598: }
2599:
2600: void
1.51 markus 2601: channel_start_open(int id)
1.44 markus 2602: {
2603: Channel *c = channel_lookup(id);
2604: if (c == NULL) {
2605: log("channel_open: %d: bad id", id);
2606: return;
2607: }
1.51 markus 2608: debug("send channel open %d", id);
1.44 markus 2609: packet_start(SSH2_MSG_CHANNEL_OPEN);
2610: packet_put_cstring(c->ctype);
2611: packet_put_int(c->self);
2612: packet_put_int(c->local_window);
2613: packet_put_int(c->local_maxpacket);
1.51 markus 2614: }
2615: void
2616: channel_open(int id)
2617: {
2618: /* XXX REMOVE ME */
2619: channel_start_open(id);
1.44 markus 2620: packet_send();
2621: }
2622: void
2623: channel_request(int id, char *service, int wantconfirm)
2624: {
2625: channel_request_start(id, service, wantconfirm);
2626: packet_send();
2627: debug("channel request %d: %s", id, service) ;
2628: }
2629: void
2630: channel_request_start(int id, char *service, int wantconfirm)
2631: {
2632: Channel *c = channel_lookup(id);
2633: if (c == NULL) {
2634: log("channel_request: %d: bad id", id);
2635: return;
2636: }
2637: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2638: packet_put_int(c->remote_id);
2639: packet_put_cstring(service);
2640: packet_put_char(wantconfirm);
2641: }
2642: void
2643: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2644: {
2645: Channel *c = channel_lookup(id);
2646: if (c == NULL) {
2647: log("channel_register_callback: %d: bad id", id);
2648: return;
2649: }
2650: c->cb_event = mtype;
2651: c->cb_fn = fn;
2652: c->cb_arg = arg;
2653: }
2654: void
2655: channel_register_cleanup(int id, channel_callback_fn *fn)
2656: {
2657: Channel *c = channel_lookup(id);
2658: if (c == NULL) {
2659: log("channel_register_cleanup: %d: bad id", id);
2660: return;
2661: }
2662: c->dettach_user = fn;
2663: }
2664: void
2665: channel_cancel_cleanup(int id)
2666: {
2667: Channel *c = channel_lookup(id);
2668: if (c == NULL) {
2669: log("channel_cancel_cleanup: %d: bad id", id);
2670: return;
2671: }
2672: c->dettach_user = NULL;
1.65 markus 2673: }
1.89 stevesk 2674: void
1.65 markus 2675: channel_register_filter(int id, channel_filter_fn *fn)
2676: {
2677: Channel *c = channel_lookup(id);
2678: if (c == NULL) {
2679: log("channel_register_filter: %d: bad id", id);
2680: return;
2681: }
2682: c->input_filter = fn;
1.44 markus 2683: }
2684:
2685: void
1.71 markus 2686: channel_set_fds(int id, int rfd, int wfd, int efd,
2687: int extusage, int nonblock)
1.44 markus 2688: {
2689: Channel *c = channel_lookup(id);
2690: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2691: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2692: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2693: c->type = SSH_CHANNEL_OPEN;
2694: /* XXX window size? */
1.68 markus 2695: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2696: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2697: packet_put_int(c->remote_id);
2698: packet_put_int(c->local_window);
1.25 markus 2699: packet_send();
1.1 deraadt 2700: }
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