Annotation of src/usr.bin/ssh/channels.c, Revision 1.91
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"
1.91 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.90 2001/02/08 21:58:28 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)) {
! 198: debug("channel: %d: rfd %d isatty", c->self, c->rfd);
! 199: c->isatty = 1;
! 200: if (!isatty(c->wfd)) {
! 201: error("channel: %d: wfd %d is not a tty?",
! 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: debug("channel: %d simulate echo (%d)", c->self, len);
! 804: }
1.25 markus 805: }
1.41 markus 806: buffer_consume(&c->output, len);
1.44 markus 807: if (compat20 && len > 0) {
808: c->local_consumed += len;
809: }
810: }
811: return 1;
812: }
813: int
814: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
815: {
816: char buf[16*1024];
817: int len;
818:
1.45 markus 819: /** XXX handle drain efd, too */
1.44 markus 820: if (c->efd != -1) {
821: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
822: FD_ISSET(c->efd, writeset) &&
823: buffer_len(&c->extended) > 0) {
824: len = write(c->efd, buffer_ptr(&c->extended),
825: buffer_len(&c->extended));
1.70 markus 826: debug2("channel %d: written %d to efd %d",
1.44 markus 827: c->self, len, c->efd);
828: if (len > 0) {
829: buffer_consume(&c->extended, len);
830: c->local_consumed += len;
831: }
832: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
833: FD_ISSET(c->efd, readset)) {
834: len = read(c->efd, buf, sizeof(buf));
1.70 markus 835: debug2("channel %d: read %d from efd %d",
1.44 markus 836: c->self, len, c->efd);
1.45 markus 837: if (len == 0) {
838: debug("channel %d: closing efd %d",
839: c->self, c->efd);
840: close(c->efd);
841: c->efd = -1;
842: } else if (len > 0)
1.44 markus 843: buffer_append(&c->extended, buf, len);
844: }
845: }
846: return 1;
847: }
848: int
849: channel_check_window(Channel *c, fd_set * readset, fd_set * writeset)
850: {
1.46 markus 851: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 852: c->local_window < c->local_window_max/2 &&
853: c->local_consumed > 0) {
854: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
855: packet_put_int(c->remote_id);
856: packet_put_int(c->local_consumed);
857: packet_send();
1.70 markus 858: debug2("channel %d: window %d sent adjust %d",
1.44 markus 859: c->self, c->local_window,
860: c->local_consumed);
861: c->local_window += c->local_consumed;
862: c->local_consumed = 0;
1.1 deraadt 863: }
1.41 markus 864: return 1;
1.1 deraadt 865: }
866:
1.41 markus 867: void
868: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
869: {
870: channel_handle_rfd(c, readset, writeset);
871: channel_handle_wfd(c, readset, writeset);
872: }
1.1 deraadt 873:
1.41 markus 874: void
1.44 markus 875: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
876: {
877: channel_handle_rfd(c, readset, writeset);
878: channel_handle_wfd(c, readset, writeset);
879: channel_handle_efd(c, readset, writeset);
880: channel_check_window(c, readset, writeset);
881: }
882:
883: void
1.41 markus 884: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 885: {
1.41 markus 886: int len;
887: /* Send buffered output data to the socket. */
888: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
889: len = write(c->sock, buffer_ptr(&c->output),
890: buffer_len(&c->output));
891: if (len <= 0)
892: buffer_consume(&c->output, buffer_len(&c->output));
893: else
894: buffer_consume(&c->output, len);
895: }
896: }
1.25 markus 897:
1.41 markus 898: void
1.44 markus 899: channel_handler_init_20(void)
900: {
901: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 902: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 903: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 904: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 905: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 906: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 907: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.44 markus 908:
909: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
910: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 911: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 912: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 913: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 914: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.44 markus 915: }
916:
917: void
1.41 markus 918: channel_handler_init_13(void)
919: {
920: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
921: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
922: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
923: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
924: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
925: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
926: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 927: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 928:
1.41 markus 929: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
930: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
931: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
932: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
933: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 934: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 935: }
1.25 markus 936:
1.41 markus 937: void
938: channel_handler_init_15(void)
939: {
940: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 941: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 942: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
943: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
944: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 945: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 946:
1.41 markus 947: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
948: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
949: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
950: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 951: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 952: }
1.27 markus 953:
1.41 markus 954: void
955: channel_handler_init(void)
956: {
957: int i;
958: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
959: channel_pre[i] = NULL;
960: channel_post[i] = NULL;
961: }
1.44 markus 962: if (compat20)
963: channel_handler_init_20();
964: else if (compat13)
1.41 markus 965: channel_handler_init_13();
966: else
967: channel_handler_init_15();
968: }
1.25 markus 969:
1.49 markus 970: void
1.41 markus 971: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
972: {
973: static int did_init = 0;
974: int i;
975: Channel *c;
1.25 markus 976:
1.41 markus 977: if (!did_init) {
978: channel_handler_init();
979: did_init = 1;
980: }
981: for (i = 0; i < channels_alloc; i++) {
982: c = &channels[i];
983: if (c->type == SSH_CHANNEL_FREE)
984: continue;
985: if (ftab[c->type] == NULL)
1.25 markus 986: continue;
1.41 markus 987: (*ftab[c->type])(c, readset, writeset);
1.44 markus 988: chan_delete_if_full_closed(c);
1.1 deraadt 989: }
990: }
991:
1.49 markus 992: void
1.84 markus 993: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp)
1.41 markus 994: {
1.84 markus 995: int n;
996: u_int sz;
997:
998: n = MAX(*maxfdp, channel_max_fd);
999:
1000: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1001: if (*readsetp == NULL || n > *maxfdp) {
1002: if (*readsetp)
1003: xfree(*readsetp);
1004: if (*writesetp)
1005: xfree(*writesetp);
1006: *readsetp = xmalloc(sz);
1007: *writesetp = xmalloc(sz);
1008: *maxfdp = n;
1009: }
1010: memset(*readsetp, 0, sz);
1011: memset(*writesetp, 0, sz);
1012:
1013: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1014: }
1015:
1.49 markus 1016: void
1.41 markus 1017: channel_after_select(fd_set * readset, fd_set * writeset)
1018: {
1019: channel_handler(channel_post, readset, writeset);
1020: }
1021:
1.84 markus 1022: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1023:
1.49 markus 1024: void
1.25 markus 1025: channel_output_poll()
1.1 deraadt 1026: {
1.25 markus 1027: int len, i;
1.41 markus 1028: Channel *c;
1.1 deraadt 1029:
1.25 markus 1030: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1031: c = &channels[i];
1.37 markus 1032:
1.27 markus 1033: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1034: if (compat13) {
1.41 markus 1035: if (c->type != SSH_CHANNEL_OPEN &&
1036: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1037: continue;
1038: } else {
1.41 markus 1039: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1040: continue;
1.41 markus 1041: if (c->istate != CHAN_INPUT_OPEN &&
1042: c->istate != CHAN_INPUT_WAIT_DRAIN)
1.37 markus 1043: continue;
1044: }
1.46 markus 1045: if (compat20 &&
1046: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.44 markus 1047: debug("channel: %d: no data after CLOSE", c->self);
1048: continue;
1049: }
1.25 markus 1050:
1051: /* Get the amount of buffered data for this channel. */
1.41 markus 1052: len = buffer_len(&c->input);
1.25 markus 1053: if (len > 0) {
1.27 markus 1054: /* Send some data for the other side over the secure connection. */
1.44 markus 1055: if (compat20) {
1056: if (len > c->remote_window)
1057: len = c->remote_window;
1058: if (len > c->remote_maxpacket)
1059: len = c->remote_maxpacket;
1.25 markus 1060: } else {
1.44 markus 1061: if (packet_is_interactive()) {
1062: if (len > 1024)
1063: len = 512;
1064: } else {
1065: /* Keep the packets at reasonable size. */
1066: if (len > packet_get_maxsize()/2)
1067: len = packet_get_maxsize()/2;
1068: }
1.25 markus 1069: }
1.41 markus 1070: if (len > 0) {
1.44 markus 1071: packet_start(compat20 ?
1072: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1073: packet_put_int(c->remote_id);
1074: packet_put_string(buffer_ptr(&c->input), len);
1075: packet_send();
1076: buffer_consume(&c->input, len);
1077: c->remote_window -= len;
1078: }
1079: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1080: if (compat13)
1081: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1082: /*
1083: * input-buffer is empty and read-socket shutdown:
1084: * tell peer, that we will not send more data: send IEOF
1085: */
1.41 markus 1086: chan_ibuf_empty(c);
1.25 markus 1087: }
1.44 markus 1088: /* Send extended data, i.e. stderr */
1089: if (compat20 &&
1090: c->remote_window > 0 &&
1091: (len = buffer_len(&c->extended)) > 0 &&
1092: c->extended_usage == CHAN_EXTENDED_READ) {
1093: if (len > c->remote_window)
1094: len = c->remote_window;
1095: if (len > c->remote_maxpacket)
1096: len = c->remote_maxpacket;
1097: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1098: packet_put_int(c->remote_id);
1099: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1100: packet_put_string(buffer_ptr(&c->extended), len);
1101: packet_send();
1102: buffer_consume(&c->extended, len);
1103: c->remote_window -= len;
1104: }
1.25 markus 1105: }
1.1 deraadt 1106: }
1107:
1.27 markus 1108: /*
1109: * This is called when a packet of type CHANNEL_DATA has just been received.
1110: * The message type has already been consumed, but channel number and data is
1111: * still there.
1112: */
1.1 deraadt 1113:
1.49 markus 1114: void
1.69 markus 1115: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1116: {
1.37 markus 1117: int id;
1.25 markus 1118: char *data;
1.77 markus 1119: u_int data_len;
1.41 markus 1120: Channel *c;
1.25 markus 1121:
1122: /* Get the channel number and verify it. */
1.37 markus 1123: id = packet_get_int();
1.41 markus 1124: c = channel_lookup(id);
1125: if (c == NULL)
1.37 markus 1126: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1127:
1128: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1129: if (c->type != SSH_CHANNEL_OPEN &&
1130: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1131: return;
1132:
1133: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1134: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1135: return;
1136:
1137: /* Get the data. */
1138: data = packet_get_string(&data_len);
1.48 markus 1139: packet_done();
1.41 markus 1140:
1.44 markus 1141: if (compat20){
1142: if (data_len > c->local_maxpacket) {
1143: log("channel %d: rcvd big packet %d, maxpack %d",
1144: c->self, data_len, c->local_maxpacket);
1145: }
1146: if (data_len > c->local_window) {
1147: log("channel %d: rcvd too much data %d, win %d",
1148: c->self, data_len, c->local_window);
1149: xfree(data);
1150: return;
1151: }
1152: c->local_window -= data_len;
1153: }else{
1154: packet_integrity_check(plen, 4 + 4 + data_len, type);
1155: }
1.41 markus 1156: buffer_append(&c->output, data, data_len);
1.25 markus 1157: xfree(data);
1.1 deraadt 1158: }
1.49 markus 1159: void
1.69 markus 1160: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1161: {
1162: int id;
1163: int tcode;
1164: char *data;
1.77 markus 1165: u_int data_len;
1.44 markus 1166: Channel *c;
1167:
1168: /* Get the channel number and verify it. */
1169: id = packet_get_int();
1170: c = channel_lookup(id);
1171:
1172: if (c == NULL)
1173: packet_disconnect("Received extended_data for bad channel %d.", id);
1174: if (c->type != SSH_CHANNEL_OPEN) {
1175: log("channel %d: ext data for non open", id);
1176: return;
1177: }
1178: tcode = packet_get_int();
1179: if (c->efd == -1 ||
1180: c->extended_usage != CHAN_EXTENDED_WRITE ||
1181: tcode != SSH2_EXTENDED_DATA_STDERR) {
1182: log("channel %d: bad ext data", c->self);
1183: return;
1184: }
1185: data = packet_get_string(&data_len);
1.48 markus 1186: packet_done();
1.44 markus 1187: if (data_len > c->local_window) {
1188: log("channel %d: rcvd too much extended_data %d, win %d",
1189: c->self, data_len, c->local_window);
1190: xfree(data);
1191: return;
1192: }
1.70 markus 1193: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1194: c->local_window -= data_len;
1195: buffer_append(&c->extended, data, data_len);
1196: xfree(data);
1197: }
1198:
1.1 deraadt 1199:
1.27 markus 1200: /*
1201: * Returns true if no channel has too much buffered data, and false if one or
1202: * more channel is overfull.
1203: */
1.1 deraadt 1204:
1.49 markus 1205: int
1.25 markus 1206: channel_not_very_much_buffered_data()
1.1 deraadt 1207: {
1.77 markus 1208: u_int i;
1.41 markus 1209: Channel *c;
1.25 markus 1210:
1211: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1212: c = &channels[i];
1213: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1214: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1215: debug("channel %d: big input buffer %d",
1216: c->self, buffer_len(&c->input));
1.25 markus 1217: return 0;
1.41 markus 1218: }
1219: if (buffer_len(&c->output) > packet_get_maxsize()) {
1220: debug("channel %d: big output buffer %d",
1221: c->self, buffer_len(&c->output));
1.25 markus 1222: return 0;
1.41 markus 1223: }
1.25 markus 1224: }
1.1 deraadt 1225: }
1.25 markus 1226: return 1;
1.1 deraadt 1227: }
1228:
1.49 markus 1229: void
1.69 markus 1230: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1231: {
1232: int id;
1233: Channel *c;
1234:
1235: packet_integrity_check(plen, 4, type);
1236:
1237: id = packet_get_int();
1238: c = channel_lookup(id);
1239: if (c == NULL)
1240: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1241: chan_rcvd_ieof(c);
1242: }
1.1 deraadt 1243:
1.49 markus 1244: void
1.69 markus 1245: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1246: {
1.41 markus 1247: int id;
1248: Channel *c;
1.1 deraadt 1249:
1.41 markus 1250: packet_integrity_check(plen, 4, type);
1251:
1252: id = packet_get_int();
1253: c = channel_lookup(id);
1254: if (c == NULL)
1255: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1256:
1257: /*
1258: * Send a confirmation that we have closed the channel and no more
1259: * data is coming for it.
1260: */
1.25 markus 1261: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1262: packet_put_int(c->remote_id);
1.25 markus 1263: packet_send();
1264:
1.27 markus 1265: /*
1266: * If the channel is in closed state, we have sent a close request,
1267: * and the other side will eventually respond with a confirmation.
1268: * Thus, we cannot free the channel here, because then there would be
1269: * no-one to receive the confirmation. The channel gets freed when
1270: * the confirmation arrives.
1271: */
1.41 markus 1272: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1273: /*
1274: * Not a closed channel - mark it as draining, which will
1275: * cause it to be freed later.
1276: */
1.41 markus 1277: buffer_consume(&c->input, buffer_len(&c->input));
1278: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1279: }
1.1 deraadt 1280: }
1281:
1.41 markus 1282: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1283: void
1.69 markus 1284: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1285: {
1286: int id = packet_get_int();
1287: Channel *c = channel_lookup(id);
1288: packet_integrity_check(plen, 4, type);
1289: if (c == NULL)
1290: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1291: chan_rcvd_oclose(c);
1292: }
1.1 deraadt 1293:
1.49 markus 1294: void
1.69 markus 1295: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1296: {
1.41 markus 1297: int id = packet_get_int();
1298: Channel *c = channel_lookup(id);
1.1 deraadt 1299:
1.48 markus 1300: packet_done();
1.41 markus 1301: if (c == NULL)
1302: packet_disconnect("Received close confirmation for "
1303: "out-of-range channel %d.", id);
1304: if (c->type != SSH_CHANNEL_CLOSED)
1305: packet_disconnect("Received close confirmation for "
1306: "non-closed channel %d (type %d).", id, c->type);
1307: channel_free(c->self);
1.1 deraadt 1308: }
1309:
1.49 markus 1310: void
1.69 markus 1311: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1312: {
1.41 markus 1313: int id, remote_id;
1314: Channel *c;
1.1 deraadt 1315:
1.44 markus 1316: if (!compat20)
1317: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1318:
1.41 markus 1319: id = packet_get_int();
1320: c = channel_lookup(id);
1.25 markus 1321:
1.41 markus 1322: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1323: packet_disconnect("Received open confirmation for "
1324: "non-opening channel %d.", id);
1325: remote_id = packet_get_int();
1.27 markus 1326: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1327: c->remote_id = remote_id;
1328: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1329:
1330: if (compat20) {
1331: c->remote_window = packet_get_int();
1332: c->remote_maxpacket = packet_get_int();
1.48 markus 1333: packet_done();
1.44 markus 1334: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1335: debug2("callback start");
1.44 markus 1336: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1337: debug2("callback done");
1.44 markus 1338: }
1339: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1340: c->remote_window, c->remote_maxpacket);
1341: }
1.1 deraadt 1342: }
1343:
1.49 markus 1344: void
1.69 markus 1345: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1346: {
1.86 markus 1347: int id, reason;
1348: char *msg = NULL, *lang = NULL;
1.41 markus 1349: Channel *c;
1350:
1.44 markus 1351: if (!compat20)
1352: packet_integrity_check(plen, 4, type);
1.41 markus 1353:
1354: id = packet_get_int();
1355: c = channel_lookup(id);
1.25 markus 1356:
1.41 markus 1357: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1358: packet_disconnect("Received open failure for "
1359: "non-opening channel %d.", id);
1.44 markus 1360: if (compat20) {
1.86 markus 1361: reason = packet_get_int();
1362: if (packet_remaining() > 0) {
1363: msg = packet_get_string(NULL);
1364: lang = packet_get_string(NULL);
1365: }
1.48 markus 1366: packet_done();
1.86 markus 1367: log("channel_open_failure: %d: reason %d %s", id,
1368: reason, msg ? msg : "<no additional info>");
1369: if (msg != NULL)
1370: xfree(msg);
1371: if (lang != NULL)
1372: xfree(lang);
1.44 markus 1373: }
1.25 markus 1374: /* Free the channel. This will also close the socket. */
1.41 markus 1375: channel_free(id);
1.1 deraadt 1376: }
1377:
1.44 markus 1378: void
1.69 markus 1379: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1380: {
1381: int id;
1382: Channel *c;
1383:
1384: id = packet_get_int();
1385: c = channel_lookup(id);
1386:
1387: if (c == NULL ||
1388: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1389: packet_disconnect("Received request for "
1390: "non-open channel %d.", id);
1391: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1392: debug2("callback start");
1.44 markus 1393: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1394: debug2("callback done");
1.44 markus 1395: } else {
1396: char *service = packet_get_string(NULL);
1397: debug("channel: %d rcvd request for %s", c->self, service);
1.70 markus 1398: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1399: xfree(service);
1400: }
1401: }
1402:
1.49 markus 1403: void
1.69 markus 1404: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1405: {
1406: Channel *c;
1407: int id, adjust;
1408:
1409: if (!compat20)
1410: return;
1411:
1412: /* Get the channel number and verify it. */
1413: id = packet_get_int();
1414: c = channel_lookup(id);
1415:
1416: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1417: log("Received window adjust for "
1418: "non-open channel %d.", id);
1419: return;
1420: }
1421: adjust = packet_get_int();
1.48 markus 1422: packet_done();
1.70 markus 1423: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1424: c->remote_window += adjust;
1425: }
1426:
1.27 markus 1427: /*
1428: * Stops listening for channels, and removes any unix domain sockets that we
1429: * might have.
1430: */
1.1 deraadt 1431:
1.49 markus 1432: void
1.25 markus 1433: channel_stop_listening()
1.1 deraadt 1434: {
1.25 markus 1435: int i;
1436: for (i = 0; i < channels_alloc; i++) {
1437: switch (channels[i].type) {
1438: case SSH_CHANNEL_AUTH_SOCKET:
1439: close(channels[i].sock);
1.76 markus 1440: unlink(channels[i].path);
1.25 markus 1441: channel_free(i);
1442: break;
1443: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1444: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1445: case SSH_CHANNEL_X11_LISTENER:
1446: close(channels[i].sock);
1447: channel_free(i);
1448: break;
1449: default:
1450: break;
1451: }
1.1 deraadt 1452: }
1453: }
1454:
1.27 markus 1455: /*
1.52 markus 1456: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1457: * descriptors after a fork.
1458: */
1.1 deraadt 1459:
1.49 markus 1460: void
1.25 markus 1461: channel_close_all()
1.1 deraadt 1462: {
1.25 markus 1463: int i;
1.52 markus 1464: for (i = 0; i < channels_alloc; i++)
1.25 markus 1465: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1466: channel_close_fds(&channels[i]);
1.1 deraadt 1467: }
1468:
1469: /* Returns true if any channel is still open. */
1470:
1.49 markus 1471: int
1.25 markus 1472: channel_still_open()
1.1 deraadt 1473: {
1.77 markus 1474: u_int i;
1.25 markus 1475: for (i = 0; i < channels_alloc; i++)
1476: switch (channels[i].type) {
1477: case SSH_CHANNEL_FREE:
1478: case SSH_CHANNEL_X11_LISTENER:
1479: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1480: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1481: case SSH_CHANNEL_CLOSED:
1482: case SSH_CHANNEL_AUTH_SOCKET:
1.75 markus 1483: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1484: continue;
1.44 markus 1485: case SSH_CHANNEL_LARVAL:
1486: if (!compat20)
1487: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1488: continue;
1.25 markus 1489: case SSH_CHANNEL_OPENING:
1490: case SSH_CHANNEL_OPEN:
1491: case SSH_CHANNEL_X11_OPEN:
1492: return 1;
1493: case SSH_CHANNEL_INPUT_DRAINING:
1494: case SSH_CHANNEL_OUTPUT_DRAINING:
1495: if (!compat13)
1496: fatal("cannot happen: OUT_DRAIN");
1497: return 1;
1498: default:
1499: fatal("channel_still_open: bad channel type %d", channels[i].type);
1500: /* NOTREACHED */
1501: }
1502: return 0;
1.1 deraadt 1503: }
1504:
1.27 markus 1505: /*
1506: * Returns a message describing the currently open forwarded connections,
1507: * suitable for sending to the client. The message contains crlf pairs for
1508: * newlines.
1509: */
1.1 deraadt 1510:
1.25 markus 1511: char *
1512: channel_open_message()
1.1 deraadt 1513: {
1.25 markus 1514: Buffer buffer;
1515: int i;
1516: char buf[512], *cp;
1517:
1518: buffer_init(&buffer);
1519: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1520: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1521: for (i = 0; i < channels_alloc; i++) {
1522: Channel *c = &channels[i];
1523: switch (c->type) {
1524: case SSH_CHANNEL_FREE:
1525: case SSH_CHANNEL_X11_LISTENER:
1526: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1527: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1528: case SSH_CHANNEL_CLOSED:
1529: case SSH_CHANNEL_AUTH_SOCKET:
1530: continue;
1.44 markus 1531: case SSH_CHANNEL_LARVAL:
1.25 markus 1532: case SSH_CHANNEL_OPENING:
1.75 markus 1533: case SSH_CHANNEL_CONNECTING:
1.25 markus 1534: case SSH_CHANNEL_OPEN:
1535: case SSH_CHANNEL_X11_OPEN:
1536: case SSH_CHANNEL_INPUT_DRAINING:
1537: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1538: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1539: c->self, c->remote_name,
1540: c->type, c->remote_id,
1541: c->istate, buffer_len(&c->input),
1.41 markus 1542: c->ostate, buffer_len(&c->output),
1543: c->rfd, c->wfd);
1.25 markus 1544: buffer_append(&buffer, buf, strlen(buf));
1545: continue;
1546: default:
1.41 markus 1547: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1548: /* NOTREACHED */
1549: }
1550: }
1551: buffer_append(&buffer, "\0", 1);
1552: cp = xstrdup(buffer_ptr(&buffer));
1553: buffer_free(&buffer);
1554: return cp;
1.1 deraadt 1555: }
1556:
1.27 markus 1557: /*
1558: * Initiate forwarding of connections to local port "port" through the secure
1559: * channel to host:port from remote side.
1560: */
1.87 markus 1561: int
1.73 markus 1562: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1563: u_short port_to_connect, int gateway_ports)
1564: {
1.87 markus 1565: return channel_request_forwarding(
1.73 markus 1566: NULL, listen_port,
1567: host_to_connect, port_to_connect,
1568: gateway_ports, /*remote_fwd*/ 0);
1569: }
1.1 deraadt 1570:
1.73 markus 1571: /*
1572: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1573: * (SSH_CHANNEL_RPORT_LISTENER).
1574: */
1.87 markus 1575: int
1.73 markus 1576: channel_request_forwarding(
1577: const char *listen_address, u_short listen_port,
1578: const char *host_to_connect, u_short port_to_connect,
1579: int gateway_ports, int remote_fwd)
1.25 markus 1580: {
1.73 markus 1581: int success, ch, sock, on = 1, ctype;
1.35 markus 1582: struct addrinfo hints, *ai, *aitop;
1583: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1584: const char *host;
1.28 markus 1585: struct linger linger;
1.25 markus 1586:
1.87 markus 1587: success = 0;
1588:
1.73 markus 1589: if (remote_fwd) {
1590: host = listen_address;
1.89 stevesk 1591: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1592: } else {
1593: host = host_to_connect;
1594: ctype =SSH_CHANNEL_PORT_LISTENER;
1595: }
1596:
1.87 markus 1597: if (strlen(host) > sizeof(channels[0].path) - 1) {
1598: error("Forward host name too long.");
1599: return success;
1600: }
1.25 markus 1601:
1.73 markus 1602: /* XXX listen_address is currently ignored */
1.28 markus 1603: /*
1.35 markus 1604: * getaddrinfo returns a loopback address if the hostname is
1605: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1606: */
1.35 markus 1607: memset(&hints, 0, sizeof(hints));
1608: hints.ai_family = IPv4or6;
1609: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1610: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1611: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1612: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1613: packet_disconnect("getaddrinfo: fatal error");
1614:
1615: for (ai = aitop; ai; ai = ai->ai_next) {
1616: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1617: continue;
1618: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1619: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1620: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1621: continue;
1622: }
1623: /* Create a port to listen for the host. */
1624: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1625: if (sock < 0) {
1626: /* this is no error since kernel may not support ipv6 */
1627: verbose("socket: %.100s", strerror(errno));
1628: continue;
1629: }
1630: /*
1631: * Set socket options. We would like the socket to disappear
1632: * as soon as it has been closed for whatever reason.
1633: */
1634: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1635: linger.l_onoff = 1;
1636: linger.l_linger = 5;
1637: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1638: debug("Local forwarding listening on %s port %s.", ntop, strport);
1639:
1640: /* Bind the socket to the address. */
1641: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1642: /* address can be in use ipv6 address is already bound */
1643: verbose("bind: %.100s", strerror(errno));
1644: close(sock);
1645: continue;
1646: }
1647: /* Start listening for connections on the socket. */
1648: if (listen(sock, 5) < 0) {
1649: error("listen: %.100s", strerror(errno));
1650: close(sock);
1651: continue;
1652: }
1653: /* Allocate a channel number for the socket. */
1.73 markus 1654: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1655: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1656: 0, xstrdup("port listener"), 1);
1.35 markus 1657: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1658: channels[ch].host_port = port_to_connect;
1659: channels[ch].listening_port = listen_port;
1.35 markus 1660: success = 1;
1661: }
1662: if (success == 0)
1.87 markus 1663: error("channel_request_forwarding: cannot listen to port: %d",
1664: listen_port);
1.35 markus 1665: freeaddrinfo(aitop);
1.87 markus 1666: return success;
1.25 markus 1667: }
1.1 deraadt 1668:
1.27 markus 1669: /*
1670: * Initiate forwarding of connections to port "port" on remote host through
1671: * the secure channel to host:port from local side.
1672: */
1.1 deraadt 1673:
1.49 markus 1674: void
1.73 markus 1675: channel_request_remote_forwarding(u_short listen_port,
1676: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1677: {
1.73 markus 1678: int payload_len, type, success = 0;
1679:
1.25 markus 1680: /* Record locally that connection to this host/port is permitted. */
1681: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1682: fatal("channel_request_remote_forwarding: too many forwards");
1683:
1684: /* Send the forward request to the remote side. */
1.44 markus 1685: if (compat20) {
1686: const char *address_to_bind = "0.0.0.0";
1687: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1688: packet_put_cstring("tcpip-forward");
1689: packet_put_char(0); /* boolean: want reply */
1690: packet_put_cstring(address_to_bind);
1691: packet_put_int(listen_port);
1.73 markus 1692: packet_send();
1693: packet_write_wait();
1694: /* Assume that server accepts the request */
1695: success = 1;
1.44 markus 1696: } else {
1697: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1698: packet_put_int(listen_port);
1699: packet_put_cstring(host_to_connect);
1.44 markus 1700: packet_put_int(port_to_connect);
1701: packet_send();
1702: packet_write_wait();
1.73 markus 1703:
1704: /* Wait for response from the remote side. */
1705: type = packet_read(&payload_len);
1706: switch (type) {
1707: case SSH_SMSG_SUCCESS:
1708: success = 1;
1709: break;
1710: case SSH_SMSG_FAILURE:
1711: log("Warning: Server denied remote port forwarding.");
1712: break;
1713: default:
1714: /* Unknown packet */
1715: packet_disconnect("Protocol error for port forward request:"
1716: "received packet type %d.", type);
1717: }
1718: }
1719: if (success) {
1720: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1721: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1722: permitted_opens[num_permitted_opens].listen_port = listen_port;
1723: num_permitted_opens++;
1.44 markus 1724: }
1.1 deraadt 1725: }
1726:
1.27 markus 1727: /*
1728: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1729: * listening for the port, and sends back a success reply (or disconnect
1730: * message if there was an error). This never returns if there was an error.
1731: */
1.1 deraadt 1732:
1.49 markus 1733: void
1.56 markus 1734: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1735: {
1.31 markus 1736: u_short port, host_port;
1.25 markus 1737: char *hostname;
1.1 deraadt 1738:
1.25 markus 1739: /* Get arguments from the packet. */
1740: port = packet_get_int();
1741: hostname = packet_get_string(NULL);
1742: host_port = packet_get_int();
1743:
1.27 markus 1744: /*
1745: * Check that an unprivileged user is not trying to forward a
1746: * privileged port.
1747: */
1.25 markus 1748: if (port < IPPORT_RESERVED && !is_root)
1749: packet_disconnect("Requested forwarding of port %d but user is not root.",
1750: port);
1.73 markus 1751: /* Initiate forwarding */
1.56 markus 1752: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1753:
1754: /* Free the argument string. */
1755: xfree(hostname);
1.1 deraadt 1756: }
1757:
1.41 markus 1758: /* XXX move to aux.c */
1759: int
1760: channel_connect_to(const char *host, u_short host_port)
1761: {
1762: struct addrinfo hints, *ai, *aitop;
1763: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1764: int gaierr;
1765: int sock = -1;
1766:
1767: memset(&hints, 0, sizeof(hints));
1768: hints.ai_family = IPv4or6;
1769: hints.ai_socktype = SOCK_STREAM;
1770: snprintf(strport, sizeof strport, "%d", host_port);
1771: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1772: error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
1773: return -1;
1774: }
1775: for (ai = aitop; ai; ai = ai->ai_next) {
1776: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1777: continue;
1778: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1779: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1780: error("channel_connect_to: getnameinfo failed");
1781: continue;
1782: }
1783: /* Create the socket. */
1784: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1785: if (sock < 0) {
1786: error("socket: %.100s", strerror(errno));
1787: continue;
1788: }
1.80 markus 1789: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1790: fatal("connect_to: F_SETFL: %s", strerror(errno));
1.41 markus 1791: /* Connect to the host/port. */
1.75 markus 1792: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1793: errno != EINPROGRESS) {
1.41 markus 1794: error("connect %.100s port %s: %.100s", ntop, strport,
1795: strerror(errno));
1796: close(sock);
1.89 stevesk 1797: continue; /* fail -- try next */
1.41 markus 1798: }
1799: break; /* success */
1800:
1801: }
1802: freeaddrinfo(aitop);
1803: if (!ai) {
1.89 stevesk 1804: error("connect %.100s port %d: failed.", host, host_port);
1.41 markus 1805: return -1;
1806: }
1807: /* success */
1808: return sock;
1809: }
1.73 markus 1810: int
1811: channel_connect_by_listen_adress(u_short listen_port)
1812: {
1813: int i;
1814: for (i = 0; i < num_permitted_opens; i++)
1815: if (permitted_opens[i].listen_port == listen_port)
1816: return channel_connect_to(
1817: permitted_opens[i].host_to_connect,
1818: permitted_opens[i].port_to_connect);
1.74 markus 1819: error("WARNING: Server requests forwarding for unknown listen_port %d",
1820: listen_port);
1.73 markus 1821: return -1;
1822: }
1823:
1.27 markus 1824: /*
1825: * This is called after receiving PORT_OPEN message. This attempts to
1826: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
1827: * or CHANNEL_OPEN_FAILURE.
1828: */
1.1 deraadt 1829:
1.49 markus 1830: void
1.69 markus 1831: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1832: {
1.31 markus 1833: u_short host_port;
1.25 markus 1834: char *host, *originator_string;
1.41 markus 1835: int remote_channel, sock = -1, newch, i, denied;
1.77 markus 1836: u_int host_len, originator_len;
1.25 markus 1837:
1838: /* Get remote channel number. */
1839: remote_channel = packet_get_int();
1840:
1841: /* Get host name to connect to. */
1842: host = packet_get_string(&host_len);
1843:
1844: /* Get port to connect to. */
1845: host_port = packet_get_int();
1846:
1847: /* Get remote originator name. */
1.29 markus 1848: if (have_hostname_in_open) {
1.25 markus 1849: originator_string = packet_get_string(&originator_len);
1.29 markus 1850: originator_len += 4; /* size of packet_int */
1851: } else {
1.25 markus 1852: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 1853: originator_len = 0; /* no originator supplied */
1854: }
1.25 markus 1855:
1.41 markus 1856: packet_integrity_check(plen,
1857: 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
1.25 markus 1858:
1859: /* Check if opening that port is permitted. */
1.41 markus 1860: denied = 0;
1.25 markus 1861: if (!all_opens_permitted) {
1862: /* Go trough all permitted ports. */
1863: for (i = 0; i < num_permitted_opens; i++)
1.41 markus 1864: if (permitted_opens[i].port_to_connect == host_port &&
1865: strcmp(permitted_opens[i].host_to_connect, host) == 0)
1.25 markus 1866: break;
1867:
1868: /* Check if we found the requested port among those permitted. */
1869: if (i >= num_permitted_opens) {
1870: /* The port is not permitted. */
1871: log("Received request to connect to %.100s:%d, but the request was denied.",
1872: host, host_port);
1.41 markus 1873: denied = 1;
1.25 markus 1874: }
1875: }
1.41 markus 1876: sock = denied ? -1 : channel_connect_to(host, host_port);
1877: if (sock > 0) {
1878: /* Allocate a channel for this connection. */
1.75 markus 1879: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
1880: sock, originator_string);
1881: /*XXX delay answer? */
1.41 markus 1882: channels[newch].remote_id = remote_channel;
1883:
1884: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1885: packet_put_int(remote_channel);
1886: packet_put_int(newch);
1887: packet_send();
1888: } else {
1889: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1890: packet_put_int(remote_channel);
1891: packet_send();
1.25 markus 1892: }
1893: xfree(host);
1.1 deraadt 1894: }
1895:
1.27 markus 1896: /*
1897: * Creates an internet domain socket for listening for X11 connections.
1898: * Returns a suitable value for the DISPLAY variable, or NULL if an error
1899: * occurs.
1900: */
1.1 deraadt 1901:
1.35 markus 1902: #define NUM_SOCKS 10
1903:
1.25 markus 1904: char *
1.33 markus 1905: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 1906: {
1.31 markus 1907: int display_number, sock;
1908: u_short port;
1.35 markus 1909: struct addrinfo hints, *ai, *aitop;
1910: char strport[NI_MAXSERV];
1911: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1912: char display[512];
1.25 markus 1913: char hostname[MAXHOSTNAMELEN];
1914:
1.33 markus 1915: for (display_number = x11_display_offset;
1.25 markus 1916: display_number < MAX_DISPLAYS;
1917: display_number++) {
1918: port = 6000 + display_number;
1.35 markus 1919: memset(&hints, 0, sizeof(hints));
1920: hints.ai_family = IPv4or6;
1.36 markus 1921: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 1922: hints.ai_socktype = SOCK_STREAM;
1923: snprintf(strport, sizeof strport, "%d", port);
1924: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1925: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 1926: return NULL;
1927: }
1.35 markus 1928: for (ai = aitop; ai; ai = ai->ai_next) {
1929: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1930: continue;
1931: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1932: if (sock < 0) {
1933: error("socket: %.100s", strerror(errno));
1934: return NULL;
1935: }
1936: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1937: debug("bind port %d: %.100s", port, strerror(errno));
1938: shutdown(sock, SHUT_RDWR);
1939: close(sock);
1940: for (n = 0; n < num_socks; n++) {
1941: shutdown(socks[n], SHUT_RDWR);
1942: close(socks[n]);
1943: }
1944: num_socks = 0;
1945: break;
1946: }
1947: socks[num_socks++] = sock;
1948: if (num_socks == NUM_SOCKS)
1949: break;
1.25 markus 1950: }
1.83 stevesk 1951: freeaddrinfo(aitop);
1.35 markus 1952: if (num_socks > 0)
1953: break;
1.25 markus 1954: }
1955: if (display_number >= MAX_DISPLAYS) {
1956: error("Failed to allocate internet-domain X11 display socket.");
1957: return NULL;
1958: }
1959: /* Start listening for connections on the socket. */
1.35 markus 1960: for (n = 0; n < num_socks; n++) {
1961: sock = socks[n];
1962: if (listen(sock, 5) < 0) {
1963: error("listen: %.100s", strerror(errno));
1964: shutdown(sock, SHUT_RDWR);
1965: close(sock);
1966: return NULL;
1967: }
1.25 markus 1968: }
1.35 markus 1969:
1.25 markus 1970: /* Set up a suitable value for the DISPLAY variable. */
1971: if (gethostname(hostname, sizeof(hostname)) < 0)
1972: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 1973: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 1974: display_number, screen_number);
1975:
1.35 markus 1976: /* Allocate a channel for each socket. */
1977: for (n = 0; n < num_socks; n++) {
1978: sock = socks[n];
1.51 markus 1979: (void) channel_new("x11 listener",
1980: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
1981: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 1982: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 1983: }
1.1 deraadt 1984:
1.25 markus 1985: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 1986: return xstrdup(display);
1.1 deraadt 1987: }
1988:
1989: #ifndef X_UNIX_PATH
1990: #define X_UNIX_PATH "/tmp/.X11-unix/X"
1991: #endif
1992:
1993: static
1994: int
1.77 markus 1995: connect_local_xsocket(u_int dnr)
1.1 deraadt 1996: {
1.25 markus 1997: static const char *const x_sockets[] = {
1998: X_UNIX_PATH "%u",
1999: "/var/X/.X11-unix/X" "%u",
2000: "/usr/spool/sockets/X11/" "%u",
2001: NULL
2002: };
2003: int sock;
2004: struct sockaddr_un addr;
2005: const char *const * path;
2006:
2007: for (path = x_sockets; *path; ++path) {
2008: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2009: if (sock < 0)
2010: error("socket: %.100s", strerror(errno));
2011: memset(&addr, 0, sizeof(addr));
2012: addr.sun_family = AF_UNIX;
2013: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2014: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2015: return sock;
2016: close(sock);
2017: }
2018: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2019: return -1;
1.1 deraadt 2020: }
2021:
1.51 markus 2022: int
2023: x11_connect_display(void)
1.1 deraadt 2024: {
1.51 markus 2025: int display_number, sock = 0;
1.25 markus 2026: const char *display;
1.51 markus 2027: char buf[1024], *cp;
1.35 markus 2028: struct addrinfo hints, *ai, *aitop;
2029: char strport[NI_MAXSERV];
2030: int gaierr;
1.25 markus 2031:
2032: /* Try to open a socket for the local X server. */
2033: display = getenv("DISPLAY");
2034: if (!display) {
2035: error("DISPLAY not set.");
1.51 markus 2036: return -1;
1.25 markus 2037: }
1.27 markus 2038: /*
2039: * Now we decode the value of the DISPLAY variable and make a
2040: * connection to the real X server.
2041: */
2042:
2043: /*
2044: * Check if it is a unix domain socket. Unix domain displays are in
2045: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2046: */
1.25 markus 2047: if (strncmp(display, "unix:", 5) == 0 ||
2048: display[0] == ':') {
2049: /* Connect to the unix domain socket. */
2050: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2051: error("Could not parse display number from DISPLAY: %.100s",
2052: display);
1.51 markus 2053: return -1;
1.25 markus 2054: }
2055: /* Create a socket. */
2056: sock = connect_local_xsocket(display_number);
2057: if (sock < 0)
1.51 markus 2058: return -1;
1.25 markus 2059:
2060: /* OK, we now have a connection to the display. */
1.51 markus 2061: return sock;
1.25 markus 2062: }
1.27 markus 2063: /*
2064: * Connect to an inet socket. The DISPLAY value is supposedly
2065: * hostname:d[.s], where hostname may also be numeric IP address.
2066: */
1.25 markus 2067: strncpy(buf, display, sizeof(buf));
2068: buf[sizeof(buf) - 1] = 0;
2069: cp = strchr(buf, ':');
2070: if (!cp) {
2071: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2072: return -1;
1.25 markus 2073: }
2074: *cp = 0;
1.27 markus 2075: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2076: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2077: error("Could not parse display number from DISPLAY: %.100s",
2078: display);
1.51 markus 2079: return -1;
1.25 markus 2080: }
1.35 markus 2081:
2082: /* Look up the host address */
2083: memset(&hints, 0, sizeof(hints));
2084: hints.ai_family = IPv4or6;
2085: hints.ai_socktype = SOCK_STREAM;
2086: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2087: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2088: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2089: return -1;
1.25 markus 2090: }
1.35 markus 2091: for (ai = aitop; ai; ai = ai->ai_next) {
2092: /* Create a socket. */
2093: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2094: if (sock < 0) {
2095: debug("socket: %.100s", strerror(errno));
1.41 markus 2096: continue;
2097: }
2098: /* Connect it to the display. */
2099: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2100: debug("connect %.100s port %d: %.100s", buf,
2101: 6000 + display_number, strerror(errno));
2102: close(sock);
2103: continue;
2104: }
2105: /* Success */
2106: break;
1.35 markus 2107: }
2108: freeaddrinfo(aitop);
2109: if (!ai) {
1.49 markus 2110: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2111: strerror(errno));
1.51 markus 2112: return -1;
1.25 markus 2113: }
1.51 markus 2114: return sock;
2115: }
2116:
2117: /*
2118: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2119: * the remote channel number. We should do whatever we want, and respond
2120: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2121: */
2122:
2123: void
1.69 markus 2124: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2125: {
2126: int remote_channel, sock = 0, newch;
2127: char *remote_host;
1.77 markus 2128: u_int remote_len;
1.25 markus 2129:
1.51 markus 2130: /* Get remote channel number. */
2131: remote_channel = packet_get_int();
2132:
2133: /* Get remote originator name. */
2134: if (have_hostname_in_open) {
2135: remote_host = packet_get_string(&remote_len);
2136: remote_len += 4;
2137: } else {
2138: remote_host = xstrdup("unknown (remote did not supply name)");
2139: remote_len = 0;
2140: }
1.25 markus 2141:
1.51 markus 2142: debug("Received X11 open request.");
2143: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2144:
1.51 markus 2145: /* Obtain a connection to the real X display. */
2146: sock = x11_connect_display();
2147: if (sock == -1) {
2148: /* Send refusal to the remote host. */
2149: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2150: packet_put_int(remote_channel);
2151: packet_send();
2152: } else {
2153: /* Allocate a channel for this connection. */
2154: newch = channel_allocate(
2155: (x11_saved_proto == NULL) ?
2156: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2157: sock, remote_host);
2158: channels[newch].remote_id = remote_channel;
1.25 markus 2159:
1.51 markus 2160: /* Send a confirmation to the remote host. */
2161: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2162: packet_put_int(remote_channel);
2163: packet_put_int(newch);
2164: packet_send();
2165: }
1.72 markus 2166: }
2167:
2168: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2169: void
2170: deny_input_open(int type, int plen, void *ctxt)
2171: {
2172: int rchan = packet_get_int();
2173: switch(type){
2174: case SSH_SMSG_AGENT_OPEN:
2175: error("Warning: ssh server tried agent forwarding.");
2176: break;
2177: case SSH_SMSG_X11_OPEN:
2178: error("Warning: ssh server tried X11 forwarding.");
2179: break;
2180: default:
2181: error("deny_input_open: type %d plen %d", type, plen);
2182: break;
2183: }
2184: error("Warning: this is probably a break in attempt by a malicious server.");
2185: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2186: packet_put_int(rchan);
2187: packet_send();
1.1 deraadt 2188: }
2189:
1.27 markus 2190: /*
2191: * Requests forwarding of X11 connections, generates fake authentication
2192: * data, and enables authentication spoofing.
2193: */
1.1 deraadt 2194:
1.49 markus 2195: void
1.51 markus 2196: x11_request_forwarding_with_spoofing(int client_session_id,
2197: const char *proto, const char *data)
1.1 deraadt 2198: {
1.77 markus 2199: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2200: u_int i, value, len;
1.25 markus 2201: char *new_data;
2202: int screen_number;
2203: const char *cp;
2204: u_int32_t rand = 0;
2205:
2206: cp = getenv("DISPLAY");
2207: if (cp)
2208: cp = strchr(cp, ':');
2209: if (cp)
2210: cp = strchr(cp, '.');
2211: if (cp)
2212: screen_number = atoi(cp + 1);
2213: else
2214: screen_number = 0;
2215:
2216: /* Save protocol name. */
2217: x11_saved_proto = xstrdup(proto);
2218:
1.27 markus 2219: /*
2220: * Extract real authentication data and generate fake data of the
2221: * same length.
2222: */
1.25 markus 2223: x11_saved_data = xmalloc(data_len);
2224: x11_fake_data = xmalloc(data_len);
2225: for (i = 0; i < data_len; i++) {
2226: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2227: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2228: if (i % 4 == 0)
2229: rand = arc4random();
2230: x11_saved_data[i] = value;
2231: x11_fake_data[i] = rand & 0xff;
2232: rand >>= 8;
2233: }
2234: x11_saved_data_len = data_len;
2235: x11_fake_data_len = data_len;
2236:
2237: /* Convert the fake data into hex. */
1.90 markus 2238: len = 2 * data_len + 1;
2239: new_data = xmalloc(len);
1.25 markus 2240: for (i = 0; i < data_len; i++)
1.90 markus 2241: snprintf(new_data + 2 * i, len - 2 * i,
2242: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2243:
2244: /* Send the request packet. */
1.51 markus 2245: if (compat20) {
2246: channel_request_start(client_session_id, "x11-req", 0);
2247: packet_put_char(0); /* XXX bool single connection */
2248: } else {
2249: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2250: }
2251: packet_put_cstring(proto);
2252: packet_put_cstring(new_data);
1.25 markus 2253: packet_put_int(screen_number);
2254: packet_send();
2255: packet_write_wait();
2256: xfree(new_data);
1.1 deraadt 2257: }
2258:
2259: /* Sends a message to the server to request authentication fd forwarding. */
2260:
1.49 markus 2261: void
1.25 markus 2262: auth_request_forwarding()
1.1 deraadt 2263: {
1.25 markus 2264: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2265: packet_send();
2266: packet_write_wait();
1.1 deraadt 2267: }
2268:
1.27 markus 2269: /*
2270: * Returns the name of the forwarded authentication socket. Returns NULL if
2271: * there is no forwarded authentication socket. The returned value points to
2272: * a static buffer.
2273: */
1.1 deraadt 2274:
1.25 markus 2275: char *
2276: auth_get_socket_name()
1.1 deraadt 2277: {
1.25 markus 2278: return channel_forwarded_auth_socket_name;
1.1 deraadt 2279: }
2280:
1.12 markus 2281: /* removes the agent forwarding socket */
2282:
1.49 markus 2283: void
1.25 markus 2284: cleanup_socket(void)
2285: {
1.78 markus 2286: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2287: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2288: }
2289:
1.27 markus 2290: /*
1.59 markus 2291: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2292: * This starts forwarding authentication requests.
2293: */
1.1 deraadt 2294:
1.59 markus 2295: int
1.25 markus 2296: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2297: {
1.25 markus 2298: int sock, newch;
2299: struct sockaddr_un sunaddr;
2300:
2301: if (auth_get_socket_name() != NULL)
2302: fatal("Protocol error: authentication forwarding requested twice.");
2303:
2304: /* Temporarily drop privileged uid for mkdir/bind. */
2305: temporarily_use_uid(pw->pw_uid);
2306:
2307: /* Allocate a buffer for the socket name, and format the name. */
2308: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2309: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2310: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2311:
2312: /* Create private directory for socket */
1.59 markus 2313: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2314: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2315: strerror(errno));
2316: restore_uid();
2317: xfree(channel_forwarded_auth_socket_name);
2318: xfree(channel_forwarded_auth_socket_dir);
2319: channel_forwarded_auth_socket_name = NULL;
2320: channel_forwarded_auth_socket_dir = NULL;
2321: return 0;
2322: }
1.25 markus 2323: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2324: channel_forwarded_auth_socket_dir, (int) getpid());
2325:
2326: if (atexit(cleanup_socket) < 0) {
2327: int saved = errno;
2328: cleanup_socket();
2329: packet_disconnect("socket: %.100s", strerror(saved));
2330: }
2331: /* Create the socket. */
2332: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2333: if (sock < 0)
2334: packet_disconnect("socket: %.100s", strerror(errno));
2335:
2336: /* Bind it to the name. */
2337: memset(&sunaddr, 0, sizeof(sunaddr));
2338: sunaddr.sun_family = AF_UNIX;
2339: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2340: sizeof(sunaddr.sun_path));
2341:
2342: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2343: packet_disconnect("bind: %.100s", strerror(errno));
2344:
2345: /* Restore the privileged uid. */
2346: restore_uid();
2347:
2348: /* Start listening on the socket. */
2349: if (listen(sock, 5) < 0)
2350: packet_disconnect("listen: %.100s", strerror(errno));
2351:
2352: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2353: newch = channel_new("auth socket",
2354: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2355: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2356: 0, xstrdup("auth socket"), 1);
2357:
1.32 deraadt 2358: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2359: sizeof(channels[newch].path));
1.59 markus 2360: return 1;
1.1 deraadt 2361: }
2362:
2363: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2364:
1.49 markus 2365: void
1.69 markus 2366: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2367: {
1.25 markus 2368: int remch, sock, newch;
2369: char *dummyname;
1.41 markus 2370:
2371: packet_integrity_check(plen, 4, type);
1.25 markus 2372:
2373: /* Read the remote channel number from the message. */
2374: remch = packet_get_int();
2375:
1.27 markus 2376: /*
2377: * Get a connection to the local authentication agent (this may again
2378: * get forwarded).
2379: */
1.25 markus 2380: sock = ssh_get_authentication_socket();
2381:
1.27 markus 2382: /*
2383: * If we could not connect the agent, send an error message back to
2384: * the server. This should never happen unless the agent dies,
2385: * because authentication forwarding is only enabled if we have an
2386: * agent.
2387: */
1.25 markus 2388: if (sock < 0) {
2389: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2390: packet_put_int(remch);
2391: packet_send();
2392: return;
2393: }
2394: debug("Forwarding authentication connection.");
1.1 deraadt 2395:
1.27 markus 2396: /*
2397: * Dummy host name. This will be freed when the channel is freed; it
2398: * will still be valid in the packet_put_string below since the
2399: * channel cannot yet be freed at that point.
2400: */
1.25 markus 2401: dummyname = xstrdup("authentication agent connection");
2402:
2403: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2404: channels[newch].remote_id = remch;
2405:
2406: /* Send a confirmation to the remote host. */
2407: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2408: packet_put_int(remch);
2409: packet_put_int(newch);
1.44 markus 2410: packet_send();
2411: }
2412:
2413: void
1.51 markus 2414: channel_start_open(int id)
1.44 markus 2415: {
2416: Channel *c = channel_lookup(id);
2417: if (c == NULL) {
2418: log("channel_open: %d: bad id", id);
2419: return;
2420: }
1.51 markus 2421: debug("send channel open %d", id);
1.44 markus 2422: packet_start(SSH2_MSG_CHANNEL_OPEN);
2423: packet_put_cstring(c->ctype);
2424: packet_put_int(c->self);
2425: packet_put_int(c->local_window);
2426: packet_put_int(c->local_maxpacket);
1.51 markus 2427: }
2428: void
2429: channel_open(int id)
2430: {
2431: /* XXX REMOVE ME */
2432: channel_start_open(id);
1.44 markus 2433: packet_send();
2434: }
2435: void
2436: channel_request(int id, char *service, int wantconfirm)
2437: {
2438: channel_request_start(id, service, wantconfirm);
2439: packet_send();
2440: debug("channel request %d: %s", id, service) ;
2441: }
2442: void
2443: channel_request_start(int id, char *service, int wantconfirm)
2444: {
2445: Channel *c = channel_lookup(id);
2446: if (c == NULL) {
2447: log("channel_request: %d: bad id", id);
2448: return;
2449: }
2450: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2451: packet_put_int(c->remote_id);
2452: packet_put_cstring(service);
2453: packet_put_char(wantconfirm);
2454: }
2455: void
2456: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2457: {
2458: Channel *c = channel_lookup(id);
2459: if (c == NULL) {
2460: log("channel_register_callback: %d: bad id", id);
2461: return;
2462: }
2463: c->cb_event = mtype;
2464: c->cb_fn = fn;
2465: c->cb_arg = arg;
2466: }
2467: void
2468: channel_register_cleanup(int id, channel_callback_fn *fn)
2469: {
2470: Channel *c = channel_lookup(id);
2471: if (c == NULL) {
2472: log("channel_register_cleanup: %d: bad id", id);
2473: return;
2474: }
2475: c->dettach_user = fn;
2476: }
2477: void
2478: channel_cancel_cleanup(int id)
2479: {
2480: Channel *c = channel_lookup(id);
2481: if (c == NULL) {
2482: log("channel_cancel_cleanup: %d: bad id", id);
2483: return;
2484: }
2485: c->dettach_user = NULL;
1.65 markus 2486: }
1.89 stevesk 2487: void
1.65 markus 2488: channel_register_filter(int id, channel_filter_fn *fn)
2489: {
2490: Channel *c = channel_lookup(id);
2491: if (c == NULL) {
2492: log("channel_register_filter: %d: bad id", id);
2493: return;
2494: }
2495: c->input_filter = fn;
1.44 markus 2496: }
2497:
2498: void
1.71 markus 2499: channel_set_fds(int id, int rfd, int wfd, int efd,
2500: int extusage, int nonblock)
1.44 markus 2501: {
2502: Channel *c = channel_lookup(id);
2503: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2504: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2505: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2506: c->type = SSH_CHANNEL_OPEN;
2507: /* XXX window size? */
1.68 markus 2508: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2509: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2510: packet_put_int(c->remote_id);
2511: packet_put_int(c->local_window);
1.25 markus 2512: packet_send();
1.1 deraadt 2513: }
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