Annotation of src/usr.bin/ssh/channels.c, Revision 1.94
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"
1.94 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.93 2001/02/28 08:54:55 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"
54: #include "uidswap.h"
1.82 markus 55: #include "log.h"
56: #include "misc.h"
1.14 markus 57: #include "channels.h"
58: #include "nchan.h"
59: #include "compat.h"
1.82 markus 60: #include "canohost.h"
1.64 markus 61: #include "key.h"
62: #include "authfd.h"
1.44 markus 63:
1.1 deraadt 64: /* Maximum number of fake X11 displays to try. */
65: #define MAX_DISPLAYS 1000
66:
1.12 markus 67: /* Max len of agent socket */
68: #define MAX_SOCKET_NAME 100
69:
1.27 markus 70: /*
71: * Pointer to an array containing all allocated channels. The array is
72: * dynamically extended as needed.
73: */
1.1 deraadt 74: static Channel *channels = NULL;
75:
1.27 markus 76: /*
77: * Size of the channel array. All slots of the array must always be
78: * initialized (at least the type field); unused slots are marked with type
79: * SSH_CHANNEL_FREE.
80: */
1.1 deraadt 81: static int channels_alloc = 0;
82:
1.27 markus 83: /*
84: * Maximum file descriptor value used in any of the channels. This is
85: * updated in channel_allocate.
86: */
1.84 markus 87: static int channel_max_fd = 0;
1.1 deraadt 88:
1.12 markus 89: /* Name and directory of socket for authentication agent forwarding. */
1.1 deraadt 90: static char *channel_forwarded_auth_socket_name = NULL;
1.25 markus 91: static char *channel_forwarded_auth_socket_dir = NULL;
1.1 deraadt 92:
93: /* Saved X11 authentication protocol name. */
94: char *x11_saved_proto = NULL;
95:
96: /* Saved X11 authentication data. This is the real data. */
97: char *x11_saved_data = NULL;
1.77 markus 98: u_int x11_saved_data_len = 0;
1.1 deraadt 99:
1.27 markus 100: /*
101: * Fake X11 authentication data. This is what the server will be sending us;
102: * we should replace any occurrences of this by the real data.
103: */
1.1 deraadt 104: char *x11_fake_data = NULL;
1.77 markus 105: u_int x11_fake_data_len;
1.1 deraadt 106:
1.27 markus 107: /*
108: * Data structure for storing which hosts are permitted for forward requests.
109: * The local sides of any remote forwards are stored in this array to prevent
110: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
111: * network (which might be behind a firewall).
112: */
1.25 markus 113: typedef struct {
1.41 markus 114: char *host_to_connect; /* Connect to 'host'. */
115: u_short port_to_connect; /* Connect to 'port'. */
116: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 117: } ForwardPermission;
118:
119: /* List of all permitted host/port pairs to connect. */
120: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
121: /* Number of permitted host/port pairs in the array. */
122: static int num_permitted_opens = 0;
1.27 markus 123: /*
124: * If this is true, all opens are permitted. This is the case on the server
125: * on which we have to trust the client anyway, and the user could do
126: * anything after logging in anyway.
127: */
1.1 deraadt 128: static int all_opens_permitted = 0;
129:
130: /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
131: static int have_hostname_in_open = 0;
1.82 markus 132:
133: /* AF_UNSPEC or AF_INET or AF_INET6 */
134: extern int IPv4or6;
1.1 deraadt 135:
136: /* Sets specific protocol options. */
137:
1.49 markus 138: void
1.25 markus 139: channel_set_options(int hostname_in_open)
1.1 deraadt 140: {
1.25 markus 141: have_hostname_in_open = hostname_in_open;
1.1 deraadt 142: }
143:
1.27 markus 144: /*
145: * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
146: * called by the server, because the user could connect to any port anyway,
147: * and the server has no way to know but to trust the client anyway.
148: */
1.1 deraadt 149:
1.49 markus 150: void
1.25 markus 151: channel_permit_all_opens()
1.1 deraadt 152: {
1.25 markus 153: all_opens_permitted = 1;
1.1 deraadt 154: }
155:
1.41 markus 156: /* lookup channel by id */
157:
158: Channel *
159: channel_lookup(int id)
160: {
161: Channel *c;
1.63 provos 162: if (id < 0 || id > channels_alloc) {
1.41 markus 163: log("channel_lookup: %d: bad id", id);
164: return NULL;
165: }
166: c = &channels[id];
167: if (c->type == SSH_CHANNEL_FREE) {
168: log("channel_lookup: %d: bad id: channel free", id);
169: return NULL;
170: }
171: return c;
1.55 markus 172: }
173:
1.27 markus 174: /*
1.55 markus 175: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 176: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 177: */
1.1 deraadt 178:
1.52 markus 179: void
1.71 markus 180: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
181: int extusage, int nonblock)
1.1 deraadt 182: {
1.25 markus 183: /* Update the maximum file descriptor value. */
1.84 markus 184: channel_max_fd = MAX(channel_max_fd, rfd);
185: channel_max_fd = MAX(channel_max_fd, wfd);
186: channel_max_fd = MAX(channel_max_fd, efd);
187:
1.27 markus 188: /* XXX set close-on-exec -markus */
1.55 markus 189:
1.52 markus 190: c->rfd = rfd;
191: c->wfd = wfd;
192: c->sock = (rfd == wfd) ? rfd : -1;
193: c->efd = efd;
194: c->extended_usage = extusage;
1.71 markus 195:
1.91 markus 196: /* XXX ugly hack: nonblock is only set by the server */
197: if (nonblock && isatty(c->rfd)) {
1.94 ! markus 198: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 199: c->isatty = 1;
200: if (!isatty(c->wfd)) {
1.94 ! markus 201: error("channel %d: wfd %d is not a tty?",
1.91 markus 202: c->self, c->wfd);
203: }
204: } else {
205: c->isatty = 0;
206: }
207:
1.71 markus 208: /* enable nonblocking mode */
209: if (nonblock) {
210: if (rfd != -1)
211: set_nonblock(rfd);
212: if (wfd != -1)
213: set_nonblock(wfd);
214: if (efd != -1)
215: set_nonblock(efd);
216: }
1.52 markus 217: }
218:
219: /*
220: * Allocate a new channel object and set its type and socket. This will cause
221: * remote_name to be freed.
222: */
223:
224: int
225: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 226: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 227: {
228: int i, found;
229: Channel *c;
1.25 markus 230:
231: /* Do initial allocation if this is the first call. */
232: if (channels_alloc == 0) {
1.44 markus 233: chan_init();
1.25 markus 234: channels_alloc = 10;
235: channels = xmalloc(channels_alloc * sizeof(Channel));
236: for (i = 0; i < channels_alloc; i++)
237: channels[i].type = SSH_CHANNEL_FREE;
1.27 markus 238: /*
239: * Kludge: arrange a call to channel_stop_listening if we
240: * terminate with fatal().
241: */
1.25 markus 242: fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
243: }
244: /* Try to find a free slot where to put the new channel. */
245: for (found = -1, i = 0; i < channels_alloc; i++)
246: if (channels[i].type == SSH_CHANNEL_FREE) {
247: /* Found a free slot. */
248: found = i;
249: break;
250: }
251: if (found == -1) {
1.27 markus 252: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 253: found = channels_alloc;
254: channels_alloc += 10;
1.70 markus 255: debug2("channel: expanding %d", channels_alloc);
1.25 markus 256: channels = xrealloc(channels, channels_alloc * sizeof(Channel));
257: for (i = found; i < channels_alloc; i++)
258: channels[i].type = SSH_CHANNEL_FREE;
259: }
260: /* Initialize and return new channel number. */
261: c = &channels[found];
262: buffer_init(&c->input);
263: buffer_init(&c->output);
1.41 markus 264: buffer_init(&c->extended);
1.25 markus 265: chan_init_iostates(c);
1.71 markus 266: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 267: c->self = found;
268: c->type = type;
1.41 markus 269: c->ctype = ctype;
1.51 markus 270: c->local_window = window;
271: c->local_window_max = window;
272: c->local_consumed = 0;
273: c->local_maxpacket = maxpack;
1.25 markus 274: c->remote_id = -1;
275: c->remote_name = remote_name;
1.41 markus 276: c->remote_window = 0;
277: c->remote_maxpacket = 0;
278: c->cb_fn = NULL;
279: c->cb_arg = NULL;
280: c->cb_event = 0;
281: c->dettach_user = NULL;
1.65 markus 282: c->input_filter = NULL;
1.25 markus 283: debug("channel %d: new [%s]", found, remote_name);
284: return found;
1.1 deraadt 285: }
1.52 markus 286: /* old interface XXX */
1.49 markus 287: int
1.41 markus 288: channel_allocate(int type, int sock, char *remote_name)
289: {
1.71 markus 290: return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
1.41 markus 291: }
1.1 deraadt 292:
1.52 markus 293:
294: /* Close all channel fd/socket. */
295:
296: void
297: channel_close_fds(Channel *c)
298: {
299: if (c->sock != -1) {
300: close(c->sock);
301: c->sock = -1;
302: }
303: if (c->rfd != -1) {
304: close(c->rfd);
305: c->rfd = -1;
306: }
307: if (c->wfd != -1) {
308: close(c->wfd);
309: c->wfd = -1;
310: }
311: if (c->efd != -1) {
312: close(c->efd);
313: c->efd = -1;
314: }
315: }
316:
317: /* Free the channel and close its fd/socket. */
1.1 deraadt 318:
1.49 markus 319: void
1.41 markus 320: channel_free(int id)
1.1 deraadt 321: {
1.41 markus 322: Channel *c = channel_lookup(id);
1.79 markus 323: char *s = channel_open_message();
324:
1.41 markus 325: if (c == NULL)
326: packet_disconnect("channel free: bad local channel %d", id);
1.79 markus 327: debug("channel_free: channel %d: status: %s", id, s);
328: xfree(s);
329:
1.44 markus 330: if (c->dettach_user != NULL) {
331: debug("channel_free: channel %d: dettaching channel user", id);
332: c->dettach_user(c->self, NULL);
333: }
1.54 markus 334: if (c->sock != -1)
335: shutdown(c->sock, SHUT_RDWR);
1.52 markus 336: channel_close_fds(c);
1.41 markus 337: buffer_free(&c->input);
338: buffer_free(&c->output);
339: buffer_free(&c->extended);
340: c->type = SSH_CHANNEL_FREE;
341: if (c->remote_name) {
342: xfree(c->remote_name);
343: c->remote_name = NULL;
1.25 markus 344: }
1.1 deraadt 345: }
346:
1.27 markus 347: /*
1.41 markus 348: * 'channel_pre*' are called just before select() to add any bits relevant to
349: * channels in the select bitmasks.
350: */
351: /*
352: * 'channel_post*': perform any appropriate operations for channels which
353: * have events pending.
1.27 markus 354: */
1.41 markus 355: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
356: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
357: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
358:
359: void
360: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
361: {
362: FD_SET(c->sock, readset);
363: }
364:
365: void
1.75 markus 366: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
367: {
368: debug3("channel %d: waiting for connection", c->self);
369: FD_SET(c->sock, writeset);
370: }
371:
372: void
1.41 markus 373: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
374: {
375: if (buffer_len(&c->input) < packet_get_maxsize())
376: FD_SET(c->sock, readset);
377: if (buffer_len(&c->output) > 0)
378: FD_SET(c->sock, writeset);
379: }
1.1 deraadt 380:
1.41 markus 381: void
382: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
383: {
384: /* test whether sockets are 'alive' for read/write */
385: if (c->istate == CHAN_INPUT_OPEN)
386: if (buffer_len(&c->input) < packet_get_maxsize())
387: FD_SET(c->sock, readset);
388: if (c->ostate == CHAN_OUTPUT_OPEN ||
389: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
390: if (buffer_len(&c->output) > 0) {
391: FD_SET(c->sock, writeset);
392: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
393: chan_obuf_empty(c);
394: }
395: }
396: }
397:
398: void
1.44 markus 399: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
400: {
401: if (c->istate == CHAN_INPUT_OPEN &&
402: c->remote_window > 0 &&
403: buffer_len(&c->input) < c->remote_window)
404: FD_SET(c->rfd, readset);
405: if (c->ostate == CHAN_OUTPUT_OPEN ||
406: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
407: if (buffer_len(&c->output) > 0) {
408: FD_SET(c->wfd, writeset);
409: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
410: chan_obuf_empty(c);
411: }
412: }
413: /** XXX check close conditions, too */
414: if (c->efd != -1) {
415: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
416: buffer_len(&c->extended) > 0)
417: FD_SET(c->efd, writeset);
418: else if (c->extended_usage == CHAN_EXTENDED_READ &&
419: buffer_len(&c->extended) < c->remote_window)
420: FD_SET(c->efd, readset);
421: }
422: }
423:
424: void
1.41 markus 425: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
426: {
427: if (buffer_len(&c->input) == 0) {
428: packet_start(SSH_MSG_CHANNEL_CLOSE);
429: packet_put_int(c->remote_id);
430: packet_send();
431: c->type = SSH_CHANNEL_CLOSED;
432: debug("Closing channel %d after input drain.", c->self);
433: }
434: }
435:
436: void
437: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
438: {
439: if (buffer_len(&c->output) == 0)
440: channel_free(c->self);
1.49 markus 441: else
1.41 markus 442: FD_SET(c->sock, writeset);
443: }
444:
445: /*
446: * This is a special state for X11 authentication spoofing. An opened X11
447: * connection (when authentication spoofing is being done) remains in this
448: * state until the first packet has been completely read. The authentication
449: * data in that packet is then substituted by the real data if it matches the
450: * fake data, and the channel is put into normal mode.
1.51 markus 451: * XXX All this happens at the client side.
1.41 markus 452: */
453: int
454: x11_open_helper(Channel *c)
1.1 deraadt 455: {
1.77 markus 456: u_char *ucp;
457: u_int proto_len, data_len;
1.25 markus 458:
1.41 markus 459: /* Check if the fixed size part of the packet is in buffer. */
460: if (buffer_len(&c->output) < 12)
461: return 0;
462:
463: /* Parse the lengths of variable-length fields. */
1.77 markus 464: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 465: if (ucp[0] == 0x42) { /* Byte order MSB first. */
466: proto_len = 256 * ucp[6] + ucp[7];
467: data_len = 256 * ucp[8] + ucp[9];
468: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
469: proto_len = ucp[6] + 256 * ucp[7];
470: data_len = ucp[8] + 256 * ucp[9];
471: } else {
472: debug("Initial X11 packet contains bad byte order byte: 0x%x",
473: ucp[0]);
474: return -1;
475: }
476:
477: /* Check if the whole packet is in buffer. */
478: if (buffer_len(&c->output) <
479: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
480: return 0;
481:
482: /* Check if authentication protocol matches. */
483: if (proto_len != strlen(x11_saved_proto) ||
484: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
485: debug("X11 connection uses different authentication protocol.");
486: return -1;
487: }
488: /* Check if authentication data matches our fake data. */
489: if (data_len != x11_fake_data_len ||
490: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
491: x11_fake_data, x11_fake_data_len) != 0) {
492: debug("X11 auth data does not match fake data.");
493: return -1;
494: }
495: /* Check fake data length */
496: if (x11_fake_data_len != x11_saved_data_len) {
497: error("X11 fake_data_len %d != saved_data_len %d",
498: x11_fake_data_len, x11_saved_data_len);
499: return -1;
500: }
501: /*
502: * Received authentication protocol and data match
503: * our fake data. Substitute the fake data with real
504: * data.
505: */
506: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
507: x11_saved_data, x11_saved_data_len);
508: return 1;
509: }
510:
511: void
512: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
513: {
514: int ret = x11_open_helper(c);
515: if (ret == 1) {
516: /* Start normal processing for the channel. */
517: c->type = SSH_CHANNEL_OPEN;
1.47 markus 518: channel_pre_open_13(c, readset, writeset);
1.41 markus 519: } else if (ret == -1) {
520: /*
521: * We have received an X11 connection that has bad
522: * authentication information.
523: */
524: log("X11 connection rejected because of wrong authentication.\r\n");
525: buffer_clear(&c->input);
526: buffer_clear(&c->output);
527: close(c->sock);
528: c->sock = -1;
529: c->type = SSH_CHANNEL_CLOSED;
530: packet_start(SSH_MSG_CHANNEL_CLOSE);
531: packet_put_int(c->remote_id);
532: packet_send();
533: }
534: }
1.25 markus 535:
1.41 markus 536: void
1.51 markus 537: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 538: {
539: int ret = x11_open_helper(c);
540: if (ret == 1) {
541: c->type = SSH_CHANNEL_OPEN;
1.57 markus 542: if (compat20)
543: channel_pre_open_20(c, readset, writeset);
544: else
545: channel_pre_open_15(c, readset, writeset);
1.41 markus 546: } else if (ret == -1) {
547: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 548: chan_read_failed(c); /** force close? */
1.41 markus 549: chan_write_failed(c);
550: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
551: }
552: }
1.25 markus 553:
1.41 markus 554: /* This is our fake X11 server socket. */
555: void
556: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
557: {
558: struct sockaddr addr;
559: int newsock, newch;
560: socklen_t addrlen;
1.85 markus 561: char buf[16384], *remote_ipaddr;
1.51 markus 562: int remote_port;
1.25 markus 563:
1.41 markus 564: if (FD_ISSET(c->sock, readset)) {
565: debug("X11 connection requested.");
566: addrlen = sizeof(addr);
567: newsock = accept(c->sock, &addr, &addrlen);
568: if (newsock < 0) {
569: error("accept: %.100s", strerror(errno));
570: return;
571: }
1.85 markus 572: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 573: remote_port = get_peer_port(newsock);
1.41 markus 574: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 575: remote_ipaddr, remote_port);
1.51 markus 576:
577: newch = channel_new("x11",
578: SSH_CHANNEL_OPENING, newsock, newsock, -1,
579: c->local_window_max, c->local_maxpacket,
1.71 markus 580: 0, xstrdup(buf), 1);
1.51 markus 581: if (compat20) {
582: packet_start(SSH2_MSG_CHANNEL_OPEN);
583: packet_put_cstring("x11");
584: packet_put_int(newch);
585: packet_put_int(c->local_window_max);
586: packet_put_int(c->local_maxpacket);
1.85 markus 587: /* originator ipaddr and port */
588: packet_put_cstring(remote_ipaddr);
1.57 markus 589: if (datafellows & SSH_BUG_X11FWD) {
590: debug("ssh2 x11 bug compat mode");
591: } else {
592: packet_put_int(remote_port);
593: }
1.51 markus 594: packet_send();
595: } else {
596: packet_start(SSH_SMSG_X11_OPEN);
597: packet_put_int(newch);
598: if (have_hostname_in_open)
599: packet_put_string(buf, strlen(buf));
600: packet_send();
601: }
1.85 markus 602: xfree(remote_ipaddr);
1.41 markus 603: }
604: }
1.25 markus 605:
1.41 markus 606: /*
607: * This socket is listening for connections to a forwarded TCP/IP port.
608: */
609: void
610: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
611: {
612: struct sockaddr addr;
613: int newsock, newch;
614: socklen_t addrlen;
1.88 markus 615: char buf[1024], *remote_ipaddr, *rtype;
1.41 markus 616: int remote_port;
1.25 markus 617:
1.73 markus 618: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
619: "forwarded-tcpip" : "direct-tcpip";
620:
1.41 markus 621: if (FD_ISSET(c->sock, readset)) {
622: debug("Connection to port %d forwarding "
623: "to %.100s port %d requested.",
624: c->listening_port, c->path, c->host_port);
625: addrlen = sizeof(addr);
626: newsock = accept(c->sock, &addr, &addrlen);
627: if (newsock < 0) {
628: error("accept: %.100s", strerror(errno));
629: return;
630: }
1.88 markus 631: remote_ipaddr = get_peer_ipaddr(newsock);
1.41 markus 632: remote_port = get_peer_port(newsock);
633: snprintf(buf, sizeof buf,
634: "listen port %d for %.100s port %d, "
635: "connect from %.200s port %d",
636: c->listening_port, c->path, c->host_port,
1.88 markus 637: remote_ipaddr, remote_port);
1.73 markus 638:
639: newch = channel_new(rtype,
1.41 markus 640: SSH_CHANNEL_OPENING, newsock, newsock, -1,
641: c->local_window_max, c->local_maxpacket,
1.71 markus 642: 0, xstrdup(buf), 1);
1.44 markus 643: if (compat20) {
644: packet_start(SSH2_MSG_CHANNEL_OPEN);
1.73 markus 645: packet_put_cstring(rtype);
1.44 markus 646: packet_put_int(newch);
647: packet_put_int(c->local_window_max);
648: packet_put_int(c->local_maxpacket);
1.73 markus 649: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
650: /* listen address, port */
651: packet_put_string(c->path, strlen(c->path));
652: packet_put_int(c->listening_port);
653: } else {
654: /* target host, port */
655: packet_put_string(c->path, strlen(c->path));
656: packet_put_int(c->host_port);
657: }
1.48 markus 658: /* originator host and port */
1.88 markus 659: packet_put_cstring(remote_ipaddr);
1.44 markus 660: packet_put_int(remote_port);
661: packet_send();
662: } else {
663: packet_start(SSH_MSG_PORT_OPEN);
664: packet_put_int(newch);
665: packet_put_string(c->path, strlen(c->path));
666: packet_put_int(c->host_port);
667: if (have_hostname_in_open) {
668: packet_put_string(buf, strlen(buf));
669: }
670: packet_send();
1.41 markus 671: }
1.88 markus 672: xfree(remote_ipaddr);
1.41 markus 673: }
674: }
1.25 markus 675:
1.41 markus 676: /*
677: * This is the authentication agent socket listening for connections from
678: * clients.
679: */
680: void
681: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
682: {
683: struct sockaddr addr;
684: int newsock, newch;
685: socklen_t addrlen;
1.25 markus 686:
1.41 markus 687: if (FD_ISSET(c->sock, readset)) {
688: addrlen = sizeof(addr);
689: newsock = accept(c->sock, &addr, &addrlen);
690: if (newsock < 0) {
691: error("accept from auth socket: %.100s", strerror(errno));
692: return;
693: }
1.73 markus 694: newch = channel_new("accepted auth socket",
695: SSH_CHANNEL_OPENING, newsock, newsock, -1,
696: c->local_window_max, c->local_maxpacket,
697: 0, xstrdup("accepted auth socket"), 1);
698: if (compat20) {
699: packet_start(SSH2_MSG_CHANNEL_OPEN);
700: packet_put_cstring("auth-agent@openssh.com");
701: packet_put_int(newch);
702: packet_put_int(c->local_window_max);
703: packet_put_int(c->local_maxpacket);
704: } else {
705: packet_start(SSH_SMSG_AGENT_OPEN);
706: packet_put_int(newch);
707: }
1.41 markus 708: packet_send();
709: }
710: }
1.25 markus 711:
1.75 markus 712: void
713: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
714: {
715: if (FD_ISSET(c->sock, writeset)) {
716: int err = 0;
717: int sz = sizeof(err);
718: c->type = SSH_CHANNEL_OPEN;
1.89 stevesk 719: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
1.75 markus 720: debug("getsockopt SO_ERROR failed");
721: } else {
722: if (err == 0) {
723: debug("channel %d: connected)", c->self);
724: } else {
725: debug("channel %d: not connected: %s",
726: c->self, strerror(err));
727: chan_read_failed(c);
728: chan_write_failed(c);
729: }
730: }
731: }
732: }
733:
1.41 markus 734: int
735: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
736: {
737: char buf[16*1024];
738: int len;
1.25 markus 739:
1.41 markus 740: if (c->rfd != -1 &&
741: FD_ISSET(c->rfd, readset)) {
742: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 743: if (len < 0 && (errno == EINTR || errno == EAGAIN))
744: return 1;
1.41 markus 745: if (len <= 0) {
1.51 markus 746: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 747: c->self, c->rfd, len);
1.25 markus 748: if (compat13) {
1.41 markus 749: buffer_consume(&c->output, buffer_len(&c->output));
750: c->type = SSH_CHANNEL_INPUT_DRAINING;
751: debug("Channel %d status set to input draining.", c->self);
1.25 markus 752: } else {
1.41 markus 753: chan_read_failed(c);
1.25 markus 754: }
1.41 markus 755: return -1;
756: }
1.65 markus 757: if(c->input_filter != NULL) {
1.66 markus 758: if (c->input_filter(c, buf, len) == -1) {
1.65 markus 759: debug("filter stops channel %d", c->self);
760: chan_read_failed(c);
761: }
762: } else {
763: buffer_append(&c->input, buf, len);
764: }
1.41 markus 765: }
766: return 1;
767: }
768: int
769: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
770: {
771: int len;
1.25 markus 772:
1.41 markus 773: /* Send buffered output data to the socket. */
774: if (c->wfd != -1 &&
775: FD_ISSET(c->wfd, writeset) &&
776: buffer_len(&c->output) > 0) {
777: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 778: buffer_len(&c->output));
779: if (len < 0 && (errno == EINTR || errno == EAGAIN))
780: return 1;
1.41 markus 781: if (len <= 0) {
782: if (compat13) {
783: buffer_consume(&c->output, buffer_len(&c->output));
784: debug("Channel %d status set to input draining.", c->self);
785: c->type = SSH_CHANNEL_INPUT_DRAINING;
786: } else {
787: chan_write_failed(c);
788: }
789: return -1;
1.91 markus 790: }
791: if (compat20 && c->isatty) {
792: struct termios tio;
793: if (tcgetattr(c->wfd, &tio) == 0 &&
794: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
795: /*
796: * Simulate echo to reduce the impact of
797: * traffic analysis.
798: */
799: packet_start(SSH2_MSG_IGNORE);
800: memset(buffer_ptr(&c->output), 0, len);
801: packet_put_string(buffer_ptr(&c->output), len);
802: packet_send();
803: }
1.25 markus 804: }
1.41 markus 805: buffer_consume(&c->output, len);
1.44 markus 806: if (compat20 && len > 0) {
807: c->local_consumed += len;
808: }
809: }
810: return 1;
811: }
812: int
813: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
814: {
815: char buf[16*1024];
816: int len;
817:
1.45 markus 818: /** XXX handle drain efd, too */
1.44 markus 819: if (c->efd != -1) {
820: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
821: FD_ISSET(c->efd, writeset) &&
822: buffer_len(&c->extended) > 0) {
823: len = write(c->efd, buffer_ptr(&c->extended),
824: buffer_len(&c->extended));
1.70 markus 825: debug2("channel %d: written %d to efd %d",
1.44 markus 826: c->self, len, c->efd);
1.93 markus 827: if (len < 0 && (errno == EINTR || errno == EAGAIN))
828: return 1;
829: if (len <= 0) {
830: debug2("channel %d: closing write-efd %d",
831: c->self, c->efd);
832: close(c->efd);
833: c->efd = -1;
834: } else {
1.44 markus 835: buffer_consume(&c->extended, len);
836: c->local_consumed += len;
837: }
838: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
839: FD_ISSET(c->efd, readset)) {
840: len = read(c->efd, buf, sizeof(buf));
1.70 markus 841: debug2("channel %d: read %d from efd %d",
1.44 markus 842: c->self, len, c->efd);
1.93 markus 843: if (len < 0 && (errno == EINTR || errno == EAGAIN))
844: return 1;
845: if (len <= 0) {
846: debug2("channel %d: closing read-efd %d",
1.45 markus 847: c->self, c->efd);
848: close(c->efd);
849: c->efd = -1;
1.93 markus 850: } else {
1.44 markus 851: buffer_append(&c->extended, buf, len);
1.93 markus 852: }
1.44 markus 853: }
854: }
855: return 1;
856: }
857: int
1.93 markus 858: channel_check_window(Channel *c)
1.44 markus 859: {
1.46 markus 860: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 861: c->local_window < c->local_window_max/2 &&
862: c->local_consumed > 0) {
863: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
864: packet_put_int(c->remote_id);
865: packet_put_int(c->local_consumed);
866: packet_send();
1.70 markus 867: debug2("channel %d: window %d sent adjust %d",
1.44 markus 868: c->self, c->local_window,
869: c->local_consumed);
870: c->local_window += c->local_consumed;
871: c->local_consumed = 0;
1.1 deraadt 872: }
1.41 markus 873: return 1;
1.1 deraadt 874: }
875:
1.41 markus 876: void
877: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
878: {
879: channel_handle_rfd(c, readset, writeset);
880: channel_handle_wfd(c, readset, writeset);
881: }
1.1 deraadt 882:
1.41 markus 883: void
1.44 markus 884: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
885: {
886: channel_handle_rfd(c, readset, writeset);
887: channel_handle_wfd(c, readset, writeset);
888: channel_handle_efd(c, readset, writeset);
1.93 markus 889:
890: channel_check_window(c);
1.44 markus 891: }
892:
893: void
1.41 markus 894: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 895: {
1.41 markus 896: int len;
897: /* Send buffered output data to the socket. */
898: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
899: len = write(c->sock, buffer_ptr(&c->output),
900: buffer_len(&c->output));
901: if (len <= 0)
902: buffer_consume(&c->output, buffer_len(&c->output));
903: else
904: buffer_consume(&c->output, len);
905: }
906: }
1.25 markus 907:
1.41 markus 908: void
1.44 markus 909: channel_handler_init_20(void)
910: {
911: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 912: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 913: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 914: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 915: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 916: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 917: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.44 markus 918:
919: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
920: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 921: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 922: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 923: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 924: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.44 markus 925: }
926:
927: void
1.41 markus 928: channel_handler_init_13(void)
929: {
930: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
931: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
932: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
933: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
934: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
935: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
936: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 937: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 938:
1.41 markus 939: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
940: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
941: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
942: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
943: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 944: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 945: }
1.25 markus 946:
1.41 markus 947: void
948: channel_handler_init_15(void)
949: {
950: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 951: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 952: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
953: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
954: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 955: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 956:
1.41 markus 957: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
958: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
959: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
960: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 961: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 962: }
1.27 markus 963:
1.41 markus 964: void
965: channel_handler_init(void)
966: {
967: int i;
968: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
969: channel_pre[i] = NULL;
970: channel_post[i] = NULL;
971: }
1.44 markus 972: if (compat20)
973: channel_handler_init_20();
974: else if (compat13)
1.41 markus 975: channel_handler_init_13();
976: else
977: channel_handler_init_15();
978: }
1.25 markus 979:
1.49 markus 980: void
1.41 markus 981: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
982: {
983: static int did_init = 0;
984: int i;
985: Channel *c;
1.25 markus 986:
1.41 markus 987: if (!did_init) {
988: channel_handler_init();
989: did_init = 1;
990: }
991: for (i = 0; i < channels_alloc; i++) {
992: c = &channels[i];
993: if (c->type == SSH_CHANNEL_FREE)
994: continue;
995: if (ftab[c->type] == NULL)
1.25 markus 996: continue;
1.41 markus 997: (*ftab[c->type])(c, readset, writeset);
1.93 markus 998: if (chan_is_dead(c)) {
999: /*
1000: * we have to remove the fd's from the select mask
1001: * before the channels are free'd and the fd's are
1002: * closed
1003: */
1004: if (c->wfd != -1)
1005: FD_CLR(c->wfd, writeset);
1006: if (c->rfd != -1)
1007: FD_CLR(c->rfd, readset);
1008: if (c->efd != -1) {
1009: if (c->extended_usage == CHAN_EXTENDED_READ)
1010: FD_CLR(c->efd, readset);
1011: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1012: FD_CLR(c->efd, writeset);
1013: }
1014: channel_free(c->self);
1015: }
1.1 deraadt 1016: }
1017: }
1018:
1.49 markus 1019: void
1.84 markus 1020: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp)
1.41 markus 1021: {
1.84 markus 1022: int n;
1023: u_int sz;
1024:
1025: n = MAX(*maxfdp, channel_max_fd);
1026:
1027: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1028: if (*readsetp == NULL || n > *maxfdp) {
1029: if (*readsetp)
1030: xfree(*readsetp);
1031: if (*writesetp)
1032: xfree(*writesetp);
1033: *readsetp = xmalloc(sz);
1034: *writesetp = xmalloc(sz);
1035: *maxfdp = n;
1036: }
1037: memset(*readsetp, 0, sz);
1038: memset(*writesetp, 0, sz);
1039:
1040: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1041: }
1042:
1.49 markus 1043: void
1.41 markus 1044: channel_after_select(fd_set * readset, fd_set * writeset)
1045: {
1046: channel_handler(channel_post, readset, writeset);
1047: }
1048:
1.84 markus 1049: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1050:
1.49 markus 1051: void
1.25 markus 1052: channel_output_poll()
1.1 deraadt 1053: {
1.25 markus 1054: int len, i;
1.41 markus 1055: Channel *c;
1.1 deraadt 1056:
1.25 markus 1057: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1058: c = &channels[i];
1.37 markus 1059:
1.27 markus 1060: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1061: if (compat13) {
1.41 markus 1062: if (c->type != SSH_CHANNEL_OPEN &&
1063: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1064: continue;
1065: } else {
1.41 markus 1066: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1067: continue;
1068: }
1.46 markus 1069: if (compat20 &&
1070: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1071: /* XXX is this true? */
1.94 ! markus 1072: debug("channel %d: no data after CLOSE", c->self);
1.44 markus 1073: continue;
1074: }
1.25 markus 1075:
1076: /* Get the amount of buffered data for this channel. */
1.93 markus 1077: if ((c->istate == CHAN_INPUT_OPEN ||
1078: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1079: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1080: /* Send some data for the other side over the secure connection. */
1.44 markus 1081: if (compat20) {
1082: if (len > c->remote_window)
1083: len = c->remote_window;
1084: if (len > c->remote_maxpacket)
1085: len = c->remote_maxpacket;
1.25 markus 1086: } else {
1.44 markus 1087: if (packet_is_interactive()) {
1088: if (len > 1024)
1089: len = 512;
1090: } else {
1091: /* Keep the packets at reasonable size. */
1092: if (len > packet_get_maxsize()/2)
1093: len = packet_get_maxsize()/2;
1094: }
1.25 markus 1095: }
1.41 markus 1096: if (len > 0) {
1.44 markus 1097: packet_start(compat20 ?
1098: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1099: packet_put_int(c->remote_id);
1100: packet_put_string(buffer_ptr(&c->input), len);
1101: packet_send();
1102: buffer_consume(&c->input, len);
1103: c->remote_window -= len;
1104: }
1105: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1106: if (compat13)
1107: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1108: /*
1109: * input-buffer is empty and read-socket shutdown:
1110: * tell peer, that we will not send more data: send IEOF
1111: */
1.41 markus 1112: chan_ibuf_empty(c);
1.25 markus 1113: }
1.44 markus 1114: /* Send extended data, i.e. stderr */
1115: if (compat20 &&
1116: c->remote_window > 0 &&
1117: (len = buffer_len(&c->extended)) > 0 &&
1118: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1119: debug2("channel %d: rwin %d elen %d euse %d",
1120: c->self, c->remote_window, buffer_len(&c->extended),
1121: c->extended_usage);
1.44 markus 1122: if (len > c->remote_window)
1123: len = c->remote_window;
1124: if (len > c->remote_maxpacket)
1125: len = c->remote_maxpacket;
1126: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1127: packet_put_int(c->remote_id);
1128: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1129: packet_put_string(buffer_ptr(&c->extended), len);
1130: packet_send();
1131: buffer_consume(&c->extended, len);
1132: c->remote_window -= len;
1.93 markus 1133: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1134: }
1.25 markus 1135: }
1.1 deraadt 1136: }
1137:
1.27 markus 1138: /*
1139: * This is called when a packet of type CHANNEL_DATA has just been received.
1140: * The message type has already been consumed, but channel number and data is
1141: * still there.
1142: */
1.1 deraadt 1143:
1.49 markus 1144: void
1.69 markus 1145: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1146: {
1.37 markus 1147: int id;
1.25 markus 1148: char *data;
1.77 markus 1149: u_int data_len;
1.41 markus 1150: Channel *c;
1.25 markus 1151:
1152: /* Get the channel number and verify it. */
1.37 markus 1153: id = packet_get_int();
1.41 markus 1154: c = channel_lookup(id);
1155: if (c == NULL)
1.37 markus 1156: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1157:
1158: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1159: if (c->type != SSH_CHANNEL_OPEN &&
1160: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1161: return;
1162:
1163: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1164: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1165: return;
1166:
1167: /* Get the data. */
1168: data = packet_get_string(&data_len);
1.48 markus 1169: packet_done();
1.41 markus 1170:
1.44 markus 1171: if (compat20){
1172: if (data_len > c->local_maxpacket) {
1173: log("channel %d: rcvd big packet %d, maxpack %d",
1174: c->self, data_len, c->local_maxpacket);
1175: }
1176: if (data_len > c->local_window) {
1177: log("channel %d: rcvd too much data %d, win %d",
1178: c->self, data_len, c->local_window);
1179: xfree(data);
1180: return;
1181: }
1182: c->local_window -= data_len;
1183: }else{
1184: packet_integrity_check(plen, 4 + 4 + data_len, type);
1185: }
1.41 markus 1186: buffer_append(&c->output, data, data_len);
1.25 markus 1187: xfree(data);
1.1 deraadt 1188: }
1.49 markus 1189: void
1.69 markus 1190: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1191: {
1192: int id;
1193: int tcode;
1194: char *data;
1.77 markus 1195: u_int data_len;
1.44 markus 1196: Channel *c;
1197:
1198: /* Get the channel number and verify it. */
1199: id = packet_get_int();
1200: c = channel_lookup(id);
1201:
1202: if (c == NULL)
1203: packet_disconnect("Received extended_data for bad channel %d.", id);
1204: if (c->type != SSH_CHANNEL_OPEN) {
1205: log("channel %d: ext data for non open", id);
1206: return;
1207: }
1208: tcode = packet_get_int();
1209: if (c->efd == -1 ||
1210: c->extended_usage != CHAN_EXTENDED_WRITE ||
1211: tcode != SSH2_EXTENDED_DATA_STDERR) {
1212: log("channel %d: bad ext data", c->self);
1213: return;
1214: }
1215: data = packet_get_string(&data_len);
1.48 markus 1216: packet_done();
1.44 markus 1217: if (data_len > c->local_window) {
1218: log("channel %d: rcvd too much extended_data %d, win %d",
1219: c->self, data_len, c->local_window);
1220: xfree(data);
1221: return;
1222: }
1.70 markus 1223: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1224: c->local_window -= data_len;
1225: buffer_append(&c->extended, data, data_len);
1226: xfree(data);
1227: }
1228:
1.1 deraadt 1229:
1.27 markus 1230: /*
1231: * Returns true if no channel has too much buffered data, and false if one or
1232: * more channel is overfull.
1233: */
1.1 deraadt 1234:
1.49 markus 1235: int
1.25 markus 1236: channel_not_very_much_buffered_data()
1.1 deraadt 1237: {
1.77 markus 1238: u_int i;
1.41 markus 1239: Channel *c;
1.25 markus 1240:
1241: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1242: c = &channels[i];
1243: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1244: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1245: debug("channel %d: big input buffer %d",
1246: c->self, buffer_len(&c->input));
1.25 markus 1247: return 0;
1.41 markus 1248: }
1249: if (buffer_len(&c->output) > packet_get_maxsize()) {
1250: debug("channel %d: big output buffer %d",
1251: c->self, buffer_len(&c->output));
1.25 markus 1252: return 0;
1.41 markus 1253: }
1.25 markus 1254: }
1.1 deraadt 1255: }
1.25 markus 1256: return 1;
1.1 deraadt 1257: }
1258:
1.49 markus 1259: void
1.69 markus 1260: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1261: {
1262: int id;
1263: Channel *c;
1264:
1265: packet_integrity_check(plen, 4, type);
1266:
1267: id = packet_get_int();
1268: c = channel_lookup(id);
1269: if (c == NULL)
1270: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1271: chan_rcvd_ieof(c);
1272: }
1.1 deraadt 1273:
1.49 markus 1274: void
1.69 markus 1275: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1276: {
1.41 markus 1277: int id;
1278: Channel *c;
1.1 deraadt 1279:
1.41 markus 1280: packet_integrity_check(plen, 4, type);
1281:
1282: id = packet_get_int();
1283: c = channel_lookup(id);
1284: if (c == NULL)
1285: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1286:
1287: /*
1288: * Send a confirmation that we have closed the channel and no more
1289: * data is coming for it.
1290: */
1.25 markus 1291: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1292: packet_put_int(c->remote_id);
1.25 markus 1293: packet_send();
1294:
1.27 markus 1295: /*
1296: * If the channel is in closed state, we have sent a close request,
1297: * and the other side will eventually respond with a confirmation.
1298: * Thus, we cannot free the channel here, because then there would be
1299: * no-one to receive the confirmation. The channel gets freed when
1300: * the confirmation arrives.
1301: */
1.41 markus 1302: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1303: /*
1304: * Not a closed channel - mark it as draining, which will
1305: * cause it to be freed later.
1306: */
1.41 markus 1307: buffer_consume(&c->input, buffer_len(&c->input));
1308: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1309: }
1.1 deraadt 1310: }
1311:
1.41 markus 1312: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1313: void
1.69 markus 1314: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1315: {
1316: int id = packet_get_int();
1317: Channel *c = channel_lookup(id);
1318: packet_integrity_check(plen, 4, type);
1319: if (c == NULL)
1320: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1321: chan_rcvd_oclose(c);
1322: }
1.1 deraadt 1323:
1.49 markus 1324: void
1.69 markus 1325: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1326: {
1.41 markus 1327: int id = packet_get_int();
1328: Channel *c = channel_lookup(id);
1.1 deraadt 1329:
1.48 markus 1330: packet_done();
1.41 markus 1331: if (c == NULL)
1332: packet_disconnect("Received close confirmation for "
1333: "out-of-range channel %d.", id);
1334: if (c->type != SSH_CHANNEL_CLOSED)
1335: packet_disconnect("Received close confirmation for "
1336: "non-closed channel %d (type %d).", id, c->type);
1337: channel_free(c->self);
1.1 deraadt 1338: }
1339:
1.49 markus 1340: void
1.69 markus 1341: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1342: {
1.41 markus 1343: int id, remote_id;
1344: Channel *c;
1.1 deraadt 1345:
1.44 markus 1346: if (!compat20)
1347: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1348:
1.41 markus 1349: id = packet_get_int();
1350: c = channel_lookup(id);
1.25 markus 1351:
1.41 markus 1352: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1353: packet_disconnect("Received open confirmation for "
1354: "non-opening channel %d.", id);
1355: remote_id = packet_get_int();
1.27 markus 1356: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1357: c->remote_id = remote_id;
1358: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1359:
1360: if (compat20) {
1361: c->remote_window = packet_get_int();
1362: c->remote_maxpacket = packet_get_int();
1.48 markus 1363: packet_done();
1.44 markus 1364: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1365: debug2("callback start");
1.44 markus 1366: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1367: debug2("callback done");
1.44 markus 1368: }
1369: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1370: c->remote_window, c->remote_maxpacket);
1371: }
1.1 deraadt 1372: }
1373:
1.49 markus 1374: void
1.69 markus 1375: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1376: {
1.86 markus 1377: int id, reason;
1378: char *msg = NULL, *lang = NULL;
1.41 markus 1379: Channel *c;
1380:
1.44 markus 1381: if (!compat20)
1382: packet_integrity_check(plen, 4, type);
1.41 markus 1383:
1384: id = packet_get_int();
1385: c = channel_lookup(id);
1.25 markus 1386:
1.41 markus 1387: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1388: packet_disconnect("Received open failure for "
1389: "non-opening channel %d.", id);
1.44 markus 1390: if (compat20) {
1.86 markus 1391: reason = packet_get_int();
1392: if (packet_remaining() > 0) {
1393: msg = packet_get_string(NULL);
1394: lang = packet_get_string(NULL);
1395: }
1.48 markus 1396: packet_done();
1.86 markus 1397: log("channel_open_failure: %d: reason %d %s", id,
1398: reason, msg ? msg : "<no additional info>");
1399: if (msg != NULL)
1400: xfree(msg);
1401: if (lang != NULL)
1402: xfree(lang);
1.44 markus 1403: }
1.25 markus 1404: /* Free the channel. This will also close the socket. */
1.41 markus 1405: channel_free(id);
1.1 deraadt 1406: }
1407:
1.44 markus 1408: void
1.69 markus 1409: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1410: {
1411: int id;
1412: Channel *c;
1413:
1414: id = packet_get_int();
1415: c = channel_lookup(id);
1416:
1417: if (c == NULL ||
1418: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1419: packet_disconnect("Received request for "
1420: "non-open channel %d.", id);
1421: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1422: debug2("callback start");
1.44 markus 1423: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1424: debug2("callback done");
1.44 markus 1425: } else {
1426: char *service = packet_get_string(NULL);
1.94 ! markus 1427: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1428: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1429: xfree(service);
1430: }
1431: }
1432:
1.49 markus 1433: void
1.69 markus 1434: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1435: {
1436: Channel *c;
1437: int id, adjust;
1438:
1439: if (!compat20)
1440: return;
1441:
1442: /* Get the channel number and verify it. */
1443: id = packet_get_int();
1444: c = channel_lookup(id);
1445:
1446: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1447: log("Received window adjust for "
1448: "non-open channel %d.", id);
1449: return;
1450: }
1451: adjust = packet_get_int();
1.48 markus 1452: packet_done();
1.70 markus 1453: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1454: c->remote_window += adjust;
1455: }
1456:
1.27 markus 1457: /*
1458: * Stops listening for channels, and removes any unix domain sockets that we
1459: * might have.
1460: */
1.1 deraadt 1461:
1.49 markus 1462: void
1.25 markus 1463: channel_stop_listening()
1.1 deraadt 1464: {
1.25 markus 1465: int i;
1466: for (i = 0; i < channels_alloc; i++) {
1467: switch (channels[i].type) {
1468: case SSH_CHANNEL_AUTH_SOCKET:
1469: close(channels[i].sock);
1.76 markus 1470: unlink(channels[i].path);
1.25 markus 1471: channel_free(i);
1472: break;
1473: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1474: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1475: case SSH_CHANNEL_X11_LISTENER:
1476: close(channels[i].sock);
1477: channel_free(i);
1478: break;
1479: default:
1480: break;
1481: }
1.1 deraadt 1482: }
1483: }
1484:
1.27 markus 1485: /*
1.52 markus 1486: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1487: * descriptors after a fork.
1488: */
1.1 deraadt 1489:
1.49 markus 1490: void
1.25 markus 1491: channel_close_all()
1.1 deraadt 1492: {
1.25 markus 1493: int i;
1.52 markus 1494: for (i = 0; i < channels_alloc; i++)
1.25 markus 1495: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1496: channel_close_fds(&channels[i]);
1.1 deraadt 1497: }
1498:
1499: /* Returns true if any channel is still open. */
1500:
1.49 markus 1501: int
1.25 markus 1502: channel_still_open()
1.1 deraadt 1503: {
1.77 markus 1504: u_int i;
1.25 markus 1505: for (i = 0; i < channels_alloc; i++)
1506: switch (channels[i].type) {
1507: case SSH_CHANNEL_FREE:
1508: case SSH_CHANNEL_X11_LISTENER:
1509: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1510: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1511: case SSH_CHANNEL_CLOSED:
1512: case SSH_CHANNEL_AUTH_SOCKET:
1.75 markus 1513: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1514: continue;
1.44 markus 1515: case SSH_CHANNEL_LARVAL:
1516: if (!compat20)
1517: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1518: continue;
1.25 markus 1519: case SSH_CHANNEL_OPENING:
1520: case SSH_CHANNEL_OPEN:
1521: case SSH_CHANNEL_X11_OPEN:
1522: return 1;
1523: case SSH_CHANNEL_INPUT_DRAINING:
1524: case SSH_CHANNEL_OUTPUT_DRAINING:
1525: if (!compat13)
1526: fatal("cannot happen: OUT_DRAIN");
1527: return 1;
1528: default:
1529: fatal("channel_still_open: bad channel type %d", channels[i].type);
1530: /* NOTREACHED */
1531: }
1532: return 0;
1.1 deraadt 1533: }
1534:
1.27 markus 1535: /*
1536: * Returns a message describing the currently open forwarded connections,
1537: * suitable for sending to the client. The message contains crlf pairs for
1538: * newlines.
1539: */
1.1 deraadt 1540:
1.25 markus 1541: char *
1542: channel_open_message()
1.1 deraadt 1543: {
1.25 markus 1544: Buffer buffer;
1545: int i;
1546: char buf[512], *cp;
1547:
1548: buffer_init(&buffer);
1549: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1550: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1551: for (i = 0; i < channels_alloc; i++) {
1552: Channel *c = &channels[i];
1553: switch (c->type) {
1554: case SSH_CHANNEL_FREE:
1555: case SSH_CHANNEL_X11_LISTENER:
1556: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1557: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1558: case SSH_CHANNEL_CLOSED:
1559: case SSH_CHANNEL_AUTH_SOCKET:
1560: continue;
1.44 markus 1561: case SSH_CHANNEL_LARVAL:
1.25 markus 1562: case SSH_CHANNEL_OPENING:
1.75 markus 1563: case SSH_CHANNEL_CONNECTING:
1.25 markus 1564: case SSH_CHANNEL_OPEN:
1565: case SSH_CHANNEL_X11_OPEN:
1566: case SSH_CHANNEL_INPUT_DRAINING:
1567: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1568: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1569: c->self, c->remote_name,
1570: c->type, c->remote_id,
1571: c->istate, buffer_len(&c->input),
1.41 markus 1572: c->ostate, buffer_len(&c->output),
1573: c->rfd, c->wfd);
1.25 markus 1574: buffer_append(&buffer, buf, strlen(buf));
1575: continue;
1576: default:
1.41 markus 1577: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1578: /* NOTREACHED */
1579: }
1580: }
1581: buffer_append(&buffer, "\0", 1);
1582: cp = xstrdup(buffer_ptr(&buffer));
1583: buffer_free(&buffer);
1584: return cp;
1.1 deraadt 1585: }
1586:
1.27 markus 1587: /*
1588: * Initiate forwarding of connections to local port "port" through the secure
1589: * channel to host:port from remote side.
1590: */
1.87 markus 1591: int
1.73 markus 1592: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1593: u_short port_to_connect, int gateway_ports)
1594: {
1.87 markus 1595: return channel_request_forwarding(
1.73 markus 1596: NULL, listen_port,
1597: host_to_connect, port_to_connect,
1598: gateway_ports, /*remote_fwd*/ 0);
1599: }
1.1 deraadt 1600:
1.73 markus 1601: /*
1602: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1603: * (SSH_CHANNEL_RPORT_LISTENER).
1604: */
1.87 markus 1605: int
1.73 markus 1606: channel_request_forwarding(
1607: const char *listen_address, u_short listen_port,
1608: const char *host_to_connect, u_short port_to_connect,
1609: int gateway_ports, int remote_fwd)
1.25 markus 1610: {
1.73 markus 1611: int success, ch, sock, on = 1, ctype;
1.35 markus 1612: struct addrinfo hints, *ai, *aitop;
1613: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1614: const char *host;
1.28 markus 1615: struct linger linger;
1.25 markus 1616:
1.87 markus 1617: success = 0;
1618:
1.73 markus 1619: if (remote_fwd) {
1620: host = listen_address;
1.89 stevesk 1621: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1622: } else {
1623: host = host_to_connect;
1624: ctype =SSH_CHANNEL_PORT_LISTENER;
1625: }
1626:
1.87 markus 1627: if (strlen(host) > sizeof(channels[0].path) - 1) {
1628: error("Forward host name too long.");
1629: return success;
1630: }
1.25 markus 1631:
1.73 markus 1632: /* XXX listen_address is currently ignored */
1.28 markus 1633: /*
1.35 markus 1634: * getaddrinfo returns a loopback address if the hostname is
1635: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1636: */
1.35 markus 1637: memset(&hints, 0, sizeof(hints));
1638: hints.ai_family = IPv4or6;
1639: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1640: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1641: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1642: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1643: packet_disconnect("getaddrinfo: fatal error");
1644:
1645: for (ai = aitop; ai; ai = ai->ai_next) {
1646: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1647: continue;
1648: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1649: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1650: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1651: continue;
1652: }
1653: /* Create a port to listen for the host. */
1654: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1655: if (sock < 0) {
1656: /* this is no error since kernel may not support ipv6 */
1657: verbose("socket: %.100s", strerror(errno));
1658: continue;
1659: }
1660: /*
1661: * Set socket options. We would like the socket to disappear
1662: * as soon as it has been closed for whatever reason.
1663: */
1664: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1665: linger.l_onoff = 1;
1666: linger.l_linger = 5;
1667: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1668: debug("Local forwarding listening on %s port %s.", ntop, strport);
1669:
1670: /* Bind the socket to the address. */
1671: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1672: /* address can be in use ipv6 address is already bound */
1673: verbose("bind: %.100s", strerror(errno));
1674: close(sock);
1675: continue;
1676: }
1677: /* Start listening for connections on the socket. */
1678: if (listen(sock, 5) < 0) {
1679: error("listen: %.100s", strerror(errno));
1680: close(sock);
1681: continue;
1682: }
1683: /* Allocate a channel number for the socket. */
1.73 markus 1684: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1685: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1686: 0, xstrdup("port listener"), 1);
1.35 markus 1687: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1688: channels[ch].host_port = port_to_connect;
1689: channels[ch].listening_port = listen_port;
1.35 markus 1690: success = 1;
1691: }
1692: if (success == 0)
1.87 markus 1693: error("channel_request_forwarding: cannot listen to port: %d",
1694: listen_port);
1.35 markus 1695: freeaddrinfo(aitop);
1.87 markus 1696: return success;
1.25 markus 1697: }
1.1 deraadt 1698:
1.27 markus 1699: /*
1700: * Initiate forwarding of connections to port "port" on remote host through
1701: * the secure channel to host:port from local side.
1702: */
1.1 deraadt 1703:
1.49 markus 1704: void
1.73 markus 1705: channel_request_remote_forwarding(u_short listen_port,
1706: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1707: {
1.73 markus 1708: int payload_len, type, success = 0;
1709:
1.25 markus 1710: /* Record locally that connection to this host/port is permitted. */
1711: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1712: fatal("channel_request_remote_forwarding: too many forwards");
1713:
1714: /* Send the forward request to the remote side. */
1.44 markus 1715: if (compat20) {
1716: const char *address_to_bind = "0.0.0.0";
1717: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1718: packet_put_cstring("tcpip-forward");
1719: packet_put_char(0); /* boolean: want reply */
1720: packet_put_cstring(address_to_bind);
1721: packet_put_int(listen_port);
1.73 markus 1722: packet_send();
1723: packet_write_wait();
1724: /* Assume that server accepts the request */
1725: success = 1;
1.44 markus 1726: } else {
1727: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1728: packet_put_int(listen_port);
1729: packet_put_cstring(host_to_connect);
1.44 markus 1730: packet_put_int(port_to_connect);
1731: packet_send();
1732: packet_write_wait();
1.73 markus 1733:
1734: /* Wait for response from the remote side. */
1735: type = packet_read(&payload_len);
1736: switch (type) {
1737: case SSH_SMSG_SUCCESS:
1738: success = 1;
1739: break;
1740: case SSH_SMSG_FAILURE:
1741: log("Warning: Server denied remote port forwarding.");
1742: break;
1743: default:
1744: /* Unknown packet */
1745: packet_disconnect("Protocol error for port forward request:"
1746: "received packet type %d.", type);
1747: }
1748: }
1749: if (success) {
1750: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1751: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1752: permitted_opens[num_permitted_opens].listen_port = listen_port;
1753: num_permitted_opens++;
1.44 markus 1754: }
1.1 deraadt 1755: }
1756:
1.27 markus 1757: /*
1758: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1759: * listening for the port, and sends back a success reply (or disconnect
1760: * message if there was an error). This never returns if there was an error.
1761: */
1.1 deraadt 1762:
1.49 markus 1763: void
1.56 markus 1764: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1765: {
1.31 markus 1766: u_short port, host_port;
1.25 markus 1767: char *hostname;
1.1 deraadt 1768:
1.25 markus 1769: /* Get arguments from the packet. */
1770: port = packet_get_int();
1771: hostname = packet_get_string(NULL);
1772: host_port = packet_get_int();
1773:
1.27 markus 1774: /*
1775: * Check that an unprivileged user is not trying to forward a
1776: * privileged port.
1777: */
1.25 markus 1778: if (port < IPPORT_RESERVED && !is_root)
1779: packet_disconnect("Requested forwarding of port %d but user is not root.",
1780: port);
1.73 markus 1781: /* Initiate forwarding */
1.56 markus 1782: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1783:
1784: /* Free the argument string. */
1785: xfree(hostname);
1.1 deraadt 1786: }
1787:
1.41 markus 1788: /* XXX move to aux.c */
1789: int
1790: channel_connect_to(const char *host, u_short host_port)
1791: {
1792: struct addrinfo hints, *ai, *aitop;
1793: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1794: int gaierr;
1795: int sock = -1;
1796:
1797: memset(&hints, 0, sizeof(hints));
1798: hints.ai_family = IPv4or6;
1799: hints.ai_socktype = SOCK_STREAM;
1800: snprintf(strport, sizeof strport, "%d", host_port);
1801: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1802: error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
1803: return -1;
1804: }
1805: for (ai = aitop; ai; ai = ai->ai_next) {
1806: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1807: continue;
1808: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1809: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1810: error("channel_connect_to: getnameinfo failed");
1811: continue;
1812: }
1813: /* Create the socket. */
1814: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1815: if (sock < 0) {
1816: error("socket: %.100s", strerror(errno));
1817: continue;
1818: }
1.80 markus 1819: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1820: fatal("connect_to: F_SETFL: %s", strerror(errno));
1.41 markus 1821: /* Connect to the host/port. */
1.75 markus 1822: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1823: errno != EINPROGRESS) {
1.41 markus 1824: error("connect %.100s port %s: %.100s", ntop, strport,
1825: strerror(errno));
1826: close(sock);
1.89 stevesk 1827: continue; /* fail -- try next */
1.41 markus 1828: }
1829: break; /* success */
1830:
1831: }
1832: freeaddrinfo(aitop);
1833: if (!ai) {
1.89 stevesk 1834: error("connect %.100s port %d: failed.", host, host_port);
1.41 markus 1835: return -1;
1836: }
1837: /* success */
1838: return sock;
1839: }
1.73 markus 1840: int
1841: channel_connect_by_listen_adress(u_short listen_port)
1842: {
1843: int i;
1844: for (i = 0; i < num_permitted_opens; i++)
1845: if (permitted_opens[i].listen_port == listen_port)
1846: return channel_connect_to(
1847: permitted_opens[i].host_to_connect,
1848: permitted_opens[i].port_to_connect);
1.74 markus 1849: error("WARNING: Server requests forwarding for unknown listen_port %d",
1850: listen_port);
1.73 markus 1851: return -1;
1852: }
1853:
1.27 markus 1854: /*
1855: * This is called after receiving PORT_OPEN message. This attempts to
1856: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
1857: * or CHANNEL_OPEN_FAILURE.
1858: */
1.1 deraadt 1859:
1.49 markus 1860: void
1.69 markus 1861: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1862: {
1.31 markus 1863: u_short host_port;
1.25 markus 1864: char *host, *originator_string;
1.41 markus 1865: int remote_channel, sock = -1, newch, i, denied;
1.77 markus 1866: u_int host_len, originator_len;
1.25 markus 1867:
1868: /* Get remote channel number. */
1869: remote_channel = packet_get_int();
1870:
1871: /* Get host name to connect to. */
1872: host = packet_get_string(&host_len);
1873:
1874: /* Get port to connect to. */
1875: host_port = packet_get_int();
1876:
1877: /* Get remote originator name. */
1.29 markus 1878: if (have_hostname_in_open) {
1.25 markus 1879: originator_string = packet_get_string(&originator_len);
1.29 markus 1880: originator_len += 4; /* size of packet_int */
1881: } else {
1.25 markus 1882: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 1883: originator_len = 0; /* no originator supplied */
1884: }
1.25 markus 1885:
1.41 markus 1886: packet_integrity_check(plen,
1887: 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
1.25 markus 1888:
1889: /* Check if opening that port is permitted. */
1.41 markus 1890: denied = 0;
1.25 markus 1891: if (!all_opens_permitted) {
1892: /* Go trough all permitted ports. */
1893: for (i = 0; i < num_permitted_opens; i++)
1.41 markus 1894: if (permitted_opens[i].port_to_connect == host_port &&
1895: strcmp(permitted_opens[i].host_to_connect, host) == 0)
1.25 markus 1896: break;
1897:
1898: /* Check if we found the requested port among those permitted. */
1899: if (i >= num_permitted_opens) {
1900: /* The port is not permitted. */
1901: log("Received request to connect to %.100s:%d, but the request was denied.",
1902: host, host_port);
1.41 markus 1903: denied = 1;
1.25 markus 1904: }
1905: }
1.41 markus 1906: sock = denied ? -1 : channel_connect_to(host, host_port);
1907: if (sock > 0) {
1908: /* Allocate a channel for this connection. */
1.75 markus 1909: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
1910: sock, originator_string);
1911: /*XXX delay answer? */
1.41 markus 1912: channels[newch].remote_id = remote_channel;
1913:
1914: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1915: packet_put_int(remote_channel);
1916: packet_put_int(newch);
1917: packet_send();
1918: } else {
1919: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1920: packet_put_int(remote_channel);
1921: packet_send();
1.25 markus 1922: }
1923: xfree(host);
1.1 deraadt 1924: }
1925:
1.27 markus 1926: /*
1927: * Creates an internet domain socket for listening for X11 connections.
1928: * Returns a suitable value for the DISPLAY variable, or NULL if an error
1929: * occurs.
1930: */
1.1 deraadt 1931:
1.35 markus 1932: #define NUM_SOCKS 10
1933:
1.25 markus 1934: char *
1.33 markus 1935: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 1936: {
1.31 markus 1937: int display_number, sock;
1938: u_short port;
1.35 markus 1939: struct addrinfo hints, *ai, *aitop;
1940: char strport[NI_MAXSERV];
1941: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1942: char display[512];
1.25 markus 1943: char hostname[MAXHOSTNAMELEN];
1944:
1.33 markus 1945: for (display_number = x11_display_offset;
1.25 markus 1946: display_number < MAX_DISPLAYS;
1947: display_number++) {
1948: port = 6000 + display_number;
1.35 markus 1949: memset(&hints, 0, sizeof(hints));
1950: hints.ai_family = IPv4or6;
1.36 markus 1951: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 1952: hints.ai_socktype = SOCK_STREAM;
1953: snprintf(strport, sizeof strport, "%d", port);
1954: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1955: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 1956: return NULL;
1957: }
1.35 markus 1958: for (ai = aitop; ai; ai = ai->ai_next) {
1959: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1960: continue;
1961: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1962: if (sock < 0) {
1963: error("socket: %.100s", strerror(errno));
1964: return NULL;
1965: }
1966: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1967: debug("bind port %d: %.100s", port, strerror(errno));
1968: shutdown(sock, SHUT_RDWR);
1969: close(sock);
1970: for (n = 0; n < num_socks; n++) {
1971: shutdown(socks[n], SHUT_RDWR);
1972: close(socks[n]);
1973: }
1974: num_socks = 0;
1975: break;
1976: }
1977: socks[num_socks++] = sock;
1978: if (num_socks == NUM_SOCKS)
1979: break;
1.25 markus 1980: }
1.83 stevesk 1981: freeaddrinfo(aitop);
1.35 markus 1982: if (num_socks > 0)
1983: break;
1.25 markus 1984: }
1985: if (display_number >= MAX_DISPLAYS) {
1986: error("Failed to allocate internet-domain X11 display socket.");
1987: return NULL;
1988: }
1989: /* Start listening for connections on the socket. */
1.35 markus 1990: for (n = 0; n < num_socks; n++) {
1991: sock = socks[n];
1992: if (listen(sock, 5) < 0) {
1993: error("listen: %.100s", strerror(errno));
1994: shutdown(sock, SHUT_RDWR);
1995: close(sock);
1996: return NULL;
1997: }
1.25 markus 1998: }
1.35 markus 1999:
1.25 markus 2000: /* Set up a suitable value for the DISPLAY variable. */
2001: if (gethostname(hostname, sizeof(hostname)) < 0)
2002: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2003: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2004: display_number, screen_number);
2005:
1.35 markus 2006: /* Allocate a channel for each socket. */
2007: for (n = 0; n < num_socks; n++) {
2008: sock = socks[n];
1.51 markus 2009: (void) channel_new("x11 listener",
2010: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2011: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2012: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2013: }
1.1 deraadt 2014:
1.25 markus 2015: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2016: return xstrdup(display);
1.1 deraadt 2017: }
2018:
2019: #ifndef X_UNIX_PATH
2020: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2021: #endif
2022:
2023: static
2024: int
1.77 markus 2025: connect_local_xsocket(u_int dnr)
1.1 deraadt 2026: {
1.25 markus 2027: static const char *const x_sockets[] = {
2028: X_UNIX_PATH "%u",
2029: "/var/X/.X11-unix/X" "%u",
2030: "/usr/spool/sockets/X11/" "%u",
2031: NULL
2032: };
2033: int sock;
2034: struct sockaddr_un addr;
2035: const char *const * path;
2036:
2037: for (path = x_sockets; *path; ++path) {
2038: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2039: if (sock < 0)
2040: error("socket: %.100s", strerror(errno));
2041: memset(&addr, 0, sizeof(addr));
2042: addr.sun_family = AF_UNIX;
2043: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2044: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2045: return sock;
2046: close(sock);
2047: }
2048: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2049: return -1;
1.1 deraadt 2050: }
2051:
1.51 markus 2052: int
2053: x11_connect_display(void)
1.1 deraadt 2054: {
1.51 markus 2055: int display_number, sock = 0;
1.25 markus 2056: const char *display;
1.51 markus 2057: char buf[1024], *cp;
1.35 markus 2058: struct addrinfo hints, *ai, *aitop;
2059: char strport[NI_MAXSERV];
2060: int gaierr;
1.25 markus 2061:
2062: /* Try to open a socket for the local X server. */
2063: display = getenv("DISPLAY");
2064: if (!display) {
2065: error("DISPLAY not set.");
1.51 markus 2066: return -1;
1.25 markus 2067: }
1.27 markus 2068: /*
2069: * Now we decode the value of the DISPLAY variable and make a
2070: * connection to the real X server.
2071: */
2072:
2073: /*
2074: * Check if it is a unix domain socket. Unix domain displays are in
2075: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2076: */
1.25 markus 2077: if (strncmp(display, "unix:", 5) == 0 ||
2078: display[0] == ':') {
2079: /* Connect to the unix domain socket. */
2080: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2081: error("Could not parse display number from DISPLAY: %.100s",
2082: display);
1.51 markus 2083: return -1;
1.25 markus 2084: }
2085: /* Create a socket. */
2086: sock = connect_local_xsocket(display_number);
2087: if (sock < 0)
1.51 markus 2088: return -1;
1.25 markus 2089:
2090: /* OK, we now have a connection to the display. */
1.51 markus 2091: return sock;
1.25 markus 2092: }
1.27 markus 2093: /*
2094: * Connect to an inet socket. The DISPLAY value is supposedly
2095: * hostname:d[.s], where hostname may also be numeric IP address.
2096: */
1.25 markus 2097: strncpy(buf, display, sizeof(buf));
2098: buf[sizeof(buf) - 1] = 0;
2099: cp = strchr(buf, ':');
2100: if (!cp) {
2101: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2102: return -1;
1.25 markus 2103: }
2104: *cp = 0;
1.27 markus 2105: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2106: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2107: error("Could not parse display number from DISPLAY: %.100s",
2108: display);
1.51 markus 2109: return -1;
1.25 markus 2110: }
1.35 markus 2111:
2112: /* Look up the host address */
2113: memset(&hints, 0, sizeof(hints));
2114: hints.ai_family = IPv4or6;
2115: hints.ai_socktype = SOCK_STREAM;
2116: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2117: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2118: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2119: return -1;
1.25 markus 2120: }
1.35 markus 2121: for (ai = aitop; ai; ai = ai->ai_next) {
2122: /* Create a socket. */
2123: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2124: if (sock < 0) {
2125: debug("socket: %.100s", strerror(errno));
1.41 markus 2126: continue;
2127: }
2128: /* Connect it to the display. */
2129: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2130: debug("connect %.100s port %d: %.100s", buf,
2131: 6000 + display_number, strerror(errno));
2132: close(sock);
2133: continue;
2134: }
2135: /* Success */
2136: break;
1.35 markus 2137: }
2138: freeaddrinfo(aitop);
2139: if (!ai) {
1.49 markus 2140: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2141: strerror(errno));
1.51 markus 2142: return -1;
1.25 markus 2143: }
1.51 markus 2144: return sock;
2145: }
2146:
2147: /*
2148: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2149: * the remote channel number. We should do whatever we want, and respond
2150: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2151: */
2152:
2153: void
1.69 markus 2154: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2155: {
2156: int remote_channel, sock = 0, newch;
2157: char *remote_host;
1.77 markus 2158: u_int remote_len;
1.25 markus 2159:
1.51 markus 2160: /* Get remote channel number. */
2161: remote_channel = packet_get_int();
2162:
2163: /* Get remote originator name. */
2164: if (have_hostname_in_open) {
2165: remote_host = packet_get_string(&remote_len);
2166: remote_len += 4;
2167: } else {
2168: remote_host = xstrdup("unknown (remote did not supply name)");
2169: remote_len = 0;
2170: }
1.25 markus 2171:
1.51 markus 2172: debug("Received X11 open request.");
2173: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2174:
1.51 markus 2175: /* Obtain a connection to the real X display. */
2176: sock = x11_connect_display();
2177: if (sock == -1) {
2178: /* Send refusal to the remote host. */
2179: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2180: packet_put_int(remote_channel);
2181: packet_send();
2182: } else {
2183: /* Allocate a channel for this connection. */
2184: newch = channel_allocate(
2185: (x11_saved_proto == NULL) ?
2186: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2187: sock, remote_host);
2188: channels[newch].remote_id = remote_channel;
1.25 markus 2189:
1.51 markus 2190: /* Send a confirmation to the remote host. */
2191: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2192: packet_put_int(remote_channel);
2193: packet_put_int(newch);
2194: packet_send();
2195: }
1.72 markus 2196: }
2197:
2198: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2199: void
2200: deny_input_open(int type, int plen, void *ctxt)
2201: {
2202: int rchan = packet_get_int();
2203: switch(type){
2204: case SSH_SMSG_AGENT_OPEN:
2205: error("Warning: ssh server tried agent forwarding.");
2206: break;
2207: case SSH_SMSG_X11_OPEN:
2208: error("Warning: ssh server tried X11 forwarding.");
2209: break;
2210: default:
2211: error("deny_input_open: type %d plen %d", type, plen);
2212: break;
2213: }
2214: error("Warning: this is probably a break in attempt by a malicious server.");
2215: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2216: packet_put_int(rchan);
2217: packet_send();
1.1 deraadt 2218: }
2219:
1.27 markus 2220: /*
2221: * Requests forwarding of X11 connections, generates fake authentication
2222: * data, and enables authentication spoofing.
2223: */
1.1 deraadt 2224:
1.49 markus 2225: void
1.51 markus 2226: x11_request_forwarding_with_spoofing(int client_session_id,
2227: const char *proto, const char *data)
1.1 deraadt 2228: {
1.77 markus 2229: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2230: u_int i, value, len;
1.25 markus 2231: char *new_data;
2232: int screen_number;
2233: const char *cp;
2234: u_int32_t rand = 0;
2235:
2236: cp = getenv("DISPLAY");
2237: if (cp)
2238: cp = strchr(cp, ':');
2239: if (cp)
2240: cp = strchr(cp, '.');
2241: if (cp)
2242: screen_number = atoi(cp + 1);
2243: else
2244: screen_number = 0;
2245:
2246: /* Save protocol name. */
2247: x11_saved_proto = xstrdup(proto);
2248:
1.27 markus 2249: /*
2250: * Extract real authentication data and generate fake data of the
2251: * same length.
2252: */
1.25 markus 2253: x11_saved_data = xmalloc(data_len);
2254: x11_fake_data = xmalloc(data_len);
2255: for (i = 0; i < data_len; i++) {
2256: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2257: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2258: if (i % 4 == 0)
2259: rand = arc4random();
2260: x11_saved_data[i] = value;
2261: x11_fake_data[i] = rand & 0xff;
2262: rand >>= 8;
2263: }
2264: x11_saved_data_len = data_len;
2265: x11_fake_data_len = data_len;
2266:
2267: /* Convert the fake data into hex. */
1.90 markus 2268: len = 2 * data_len + 1;
2269: new_data = xmalloc(len);
1.25 markus 2270: for (i = 0; i < data_len; i++)
1.90 markus 2271: snprintf(new_data + 2 * i, len - 2 * i,
2272: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2273:
2274: /* Send the request packet. */
1.51 markus 2275: if (compat20) {
2276: channel_request_start(client_session_id, "x11-req", 0);
2277: packet_put_char(0); /* XXX bool single connection */
2278: } else {
2279: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2280: }
2281: packet_put_cstring(proto);
2282: packet_put_cstring(new_data);
1.25 markus 2283: packet_put_int(screen_number);
2284: packet_send();
2285: packet_write_wait();
2286: xfree(new_data);
1.1 deraadt 2287: }
2288:
2289: /* Sends a message to the server to request authentication fd forwarding. */
2290:
1.49 markus 2291: void
1.25 markus 2292: auth_request_forwarding()
1.1 deraadt 2293: {
1.25 markus 2294: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2295: packet_send();
2296: packet_write_wait();
1.1 deraadt 2297: }
2298:
1.27 markus 2299: /*
2300: * Returns the name of the forwarded authentication socket. Returns NULL if
2301: * there is no forwarded authentication socket. The returned value points to
2302: * a static buffer.
2303: */
1.1 deraadt 2304:
1.25 markus 2305: char *
2306: auth_get_socket_name()
1.1 deraadt 2307: {
1.25 markus 2308: return channel_forwarded_auth_socket_name;
1.1 deraadt 2309: }
2310:
1.12 markus 2311: /* removes the agent forwarding socket */
2312:
1.49 markus 2313: void
1.25 markus 2314: cleanup_socket(void)
2315: {
1.78 markus 2316: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2317: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2318: }
2319:
1.27 markus 2320: /*
1.59 markus 2321: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2322: * This starts forwarding authentication requests.
2323: */
1.1 deraadt 2324:
1.59 markus 2325: int
1.25 markus 2326: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2327: {
1.25 markus 2328: int sock, newch;
2329: struct sockaddr_un sunaddr;
2330:
2331: if (auth_get_socket_name() != NULL)
2332: fatal("Protocol error: authentication forwarding requested twice.");
2333:
2334: /* Temporarily drop privileged uid for mkdir/bind. */
2335: temporarily_use_uid(pw->pw_uid);
2336:
2337: /* Allocate a buffer for the socket name, and format the name. */
2338: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2339: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2340: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2341:
2342: /* Create private directory for socket */
1.59 markus 2343: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2344: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2345: strerror(errno));
2346: restore_uid();
2347: xfree(channel_forwarded_auth_socket_name);
2348: xfree(channel_forwarded_auth_socket_dir);
2349: channel_forwarded_auth_socket_name = NULL;
2350: channel_forwarded_auth_socket_dir = NULL;
2351: return 0;
2352: }
1.25 markus 2353: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2354: channel_forwarded_auth_socket_dir, (int) getpid());
2355:
2356: if (atexit(cleanup_socket) < 0) {
2357: int saved = errno;
2358: cleanup_socket();
2359: packet_disconnect("socket: %.100s", strerror(saved));
2360: }
2361: /* Create the socket. */
2362: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2363: if (sock < 0)
2364: packet_disconnect("socket: %.100s", strerror(errno));
2365:
2366: /* Bind it to the name. */
2367: memset(&sunaddr, 0, sizeof(sunaddr));
2368: sunaddr.sun_family = AF_UNIX;
2369: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2370: sizeof(sunaddr.sun_path));
2371:
2372: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2373: packet_disconnect("bind: %.100s", strerror(errno));
2374:
2375: /* Restore the privileged uid. */
2376: restore_uid();
2377:
2378: /* Start listening on the socket. */
2379: if (listen(sock, 5) < 0)
2380: packet_disconnect("listen: %.100s", strerror(errno));
2381:
2382: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2383: newch = channel_new("auth socket",
2384: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2385: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2386: 0, xstrdup("auth socket"), 1);
2387:
1.32 deraadt 2388: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2389: sizeof(channels[newch].path));
1.59 markus 2390: return 1;
1.1 deraadt 2391: }
2392:
2393: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2394:
1.49 markus 2395: void
1.69 markus 2396: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2397: {
1.25 markus 2398: int remch, sock, newch;
2399: char *dummyname;
1.41 markus 2400:
2401: packet_integrity_check(plen, 4, type);
1.25 markus 2402:
2403: /* Read the remote channel number from the message. */
2404: remch = packet_get_int();
2405:
1.27 markus 2406: /*
2407: * Get a connection to the local authentication agent (this may again
2408: * get forwarded).
2409: */
1.25 markus 2410: sock = ssh_get_authentication_socket();
2411:
1.27 markus 2412: /*
2413: * If we could not connect the agent, send an error message back to
2414: * the server. This should never happen unless the agent dies,
2415: * because authentication forwarding is only enabled if we have an
2416: * agent.
2417: */
1.25 markus 2418: if (sock < 0) {
2419: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2420: packet_put_int(remch);
2421: packet_send();
2422: return;
2423: }
2424: debug("Forwarding authentication connection.");
1.1 deraadt 2425:
1.27 markus 2426: /*
2427: * Dummy host name. This will be freed when the channel is freed; it
2428: * will still be valid in the packet_put_string below since the
2429: * channel cannot yet be freed at that point.
2430: */
1.25 markus 2431: dummyname = xstrdup("authentication agent connection");
2432:
2433: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2434: channels[newch].remote_id = remch;
2435:
2436: /* Send a confirmation to the remote host. */
2437: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2438: packet_put_int(remch);
2439: packet_put_int(newch);
1.44 markus 2440: packet_send();
2441: }
2442:
2443: void
1.51 markus 2444: channel_start_open(int id)
1.44 markus 2445: {
2446: Channel *c = channel_lookup(id);
2447: if (c == NULL) {
2448: log("channel_open: %d: bad id", id);
2449: return;
2450: }
1.51 markus 2451: debug("send channel open %d", id);
1.44 markus 2452: packet_start(SSH2_MSG_CHANNEL_OPEN);
2453: packet_put_cstring(c->ctype);
2454: packet_put_int(c->self);
2455: packet_put_int(c->local_window);
2456: packet_put_int(c->local_maxpacket);
1.51 markus 2457: }
2458: void
2459: channel_open(int id)
2460: {
2461: /* XXX REMOVE ME */
2462: channel_start_open(id);
1.44 markus 2463: packet_send();
2464: }
2465: void
2466: channel_request(int id, char *service, int wantconfirm)
2467: {
2468: channel_request_start(id, service, wantconfirm);
2469: packet_send();
2470: debug("channel request %d: %s", id, service) ;
2471: }
2472: void
2473: channel_request_start(int id, char *service, int wantconfirm)
2474: {
2475: Channel *c = channel_lookup(id);
2476: if (c == NULL) {
2477: log("channel_request: %d: bad id", id);
2478: return;
2479: }
2480: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2481: packet_put_int(c->remote_id);
2482: packet_put_cstring(service);
2483: packet_put_char(wantconfirm);
2484: }
2485: void
2486: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2487: {
2488: Channel *c = channel_lookup(id);
2489: if (c == NULL) {
2490: log("channel_register_callback: %d: bad id", id);
2491: return;
2492: }
2493: c->cb_event = mtype;
2494: c->cb_fn = fn;
2495: c->cb_arg = arg;
2496: }
2497: void
2498: channel_register_cleanup(int id, channel_callback_fn *fn)
2499: {
2500: Channel *c = channel_lookup(id);
2501: if (c == NULL) {
2502: log("channel_register_cleanup: %d: bad id", id);
2503: return;
2504: }
2505: c->dettach_user = fn;
2506: }
2507: void
2508: channel_cancel_cleanup(int id)
2509: {
2510: Channel *c = channel_lookup(id);
2511: if (c == NULL) {
2512: log("channel_cancel_cleanup: %d: bad id", id);
2513: return;
2514: }
2515: c->dettach_user = NULL;
1.65 markus 2516: }
1.89 stevesk 2517: void
1.65 markus 2518: channel_register_filter(int id, channel_filter_fn *fn)
2519: {
2520: Channel *c = channel_lookup(id);
2521: if (c == NULL) {
2522: log("channel_register_filter: %d: bad id", id);
2523: return;
2524: }
2525: c->input_filter = fn;
1.44 markus 2526: }
2527:
2528: void
1.71 markus 2529: channel_set_fds(int id, int rfd, int wfd, int efd,
2530: int extusage, int nonblock)
1.44 markus 2531: {
2532: Channel *c = channel_lookup(id);
2533: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2534: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2535: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2536: c->type = SSH_CHANNEL_OPEN;
2537: /* XXX window size? */
1.68 markus 2538: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2539: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2540: packet_put_int(c->remote_id);
2541: packet_put_int(c->local_window);
1.25 markus 2542: packet_send();
1.1 deraadt 2543: }
![[BACK]](/icons/back.gif){kind=icon}
Return to channels.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh