Annotation of src/usr.bin/ssh/channels.c, Revision 1.101
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"
1.101 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.100 2001/04/04 20:25:35 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:
1.41 markus 144: /* lookup channel by id */
145:
146: Channel *
147: channel_lookup(int id)
148: {
149: Channel *c;
1.63 provos 150: if (id < 0 || id > channels_alloc) {
1.41 markus 151: log("channel_lookup: %d: bad id", id);
152: return NULL;
153: }
154: c = &channels[id];
155: if (c->type == SSH_CHANNEL_FREE) {
156: log("channel_lookup: %d: bad id: channel free", id);
157: return NULL;
158: }
159: return c;
1.55 markus 160: }
161:
1.27 markus 162: /*
1.55 markus 163: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 164: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 165: */
1.1 deraadt 166:
1.52 markus 167: void
1.71 markus 168: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
169: int extusage, int nonblock)
1.1 deraadt 170: {
1.25 markus 171: /* Update the maximum file descriptor value. */
1.84 markus 172: channel_max_fd = MAX(channel_max_fd, rfd);
173: channel_max_fd = MAX(channel_max_fd, wfd);
174: channel_max_fd = MAX(channel_max_fd, efd);
175:
1.27 markus 176: /* XXX set close-on-exec -markus */
1.55 markus 177:
1.52 markus 178: c->rfd = rfd;
179: c->wfd = wfd;
180: c->sock = (rfd == wfd) ? rfd : -1;
181: c->efd = efd;
182: c->extended_usage = extusage;
1.71 markus 183:
1.91 markus 184: /* XXX ugly hack: nonblock is only set by the server */
185: if (nonblock && isatty(c->rfd)) {
1.94 markus 186: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 187: c->isatty = 1;
188: if (!isatty(c->wfd)) {
1.94 markus 189: error("channel %d: wfd %d is not a tty?",
1.91 markus 190: c->self, c->wfd);
191: }
192: } else {
193: c->isatty = 0;
194: }
195:
1.71 markus 196: /* enable nonblocking mode */
197: if (nonblock) {
198: if (rfd != -1)
199: set_nonblock(rfd);
200: if (wfd != -1)
201: set_nonblock(wfd);
202: if (efd != -1)
203: set_nonblock(efd);
204: }
1.52 markus 205: }
206:
207: /*
208: * Allocate a new channel object and set its type and socket. This will cause
209: * remote_name to be freed.
210: */
211:
212: int
213: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 214: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 215: {
216: int i, found;
217: Channel *c;
1.25 markus 218:
219: /* Do initial allocation if this is the first call. */
220: if (channels_alloc == 0) {
1.44 markus 221: chan_init();
1.25 markus 222: channels_alloc = 10;
223: channels = xmalloc(channels_alloc * sizeof(Channel));
224: for (i = 0; i < channels_alloc; i++)
225: channels[i].type = SSH_CHANNEL_FREE;
1.27 markus 226: /*
227: * Kludge: arrange a call to channel_stop_listening if we
228: * terminate with fatal().
229: */
1.25 markus 230: fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
231: }
232: /* Try to find a free slot where to put the new channel. */
233: for (found = -1, i = 0; i < channels_alloc; i++)
234: if (channels[i].type == SSH_CHANNEL_FREE) {
235: /* Found a free slot. */
236: found = i;
237: break;
238: }
239: if (found == -1) {
1.27 markus 240: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 241: found = channels_alloc;
242: channels_alloc += 10;
1.70 markus 243: debug2("channel: expanding %d", channels_alloc);
1.25 markus 244: channels = xrealloc(channels, channels_alloc * sizeof(Channel));
245: for (i = found; i < channels_alloc; i++)
246: channels[i].type = SSH_CHANNEL_FREE;
247: }
248: /* Initialize and return new channel number. */
249: c = &channels[found];
250: buffer_init(&c->input);
251: buffer_init(&c->output);
1.41 markus 252: buffer_init(&c->extended);
1.25 markus 253: chan_init_iostates(c);
1.71 markus 254: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 255: c->self = found;
256: c->type = type;
1.41 markus 257: c->ctype = ctype;
1.51 markus 258: c->local_window = window;
259: c->local_window_max = window;
260: c->local_consumed = 0;
261: c->local_maxpacket = maxpack;
1.25 markus 262: c->remote_id = -1;
263: c->remote_name = remote_name;
1.41 markus 264: c->remote_window = 0;
265: c->remote_maxpacket = 0;
266: c->cb_fn = NULL;
267: c->cb_arg = NULL;
268: c->cb_event = 0;
269: c->dettach_user = NULL;
1.65 markus 270: c->input_filter = NULL;
1.25 markus 271: debug("channel %d: new [%s]", found, remote_name);
272: return found;
1.1 deraadt 273: }
1.52 markus 274: /* old interface XXX */
1.49 markus 275: int
1.41 markus 276: channel_allocate(int type, int sock, char *remote_name)
277: {
1.71 markus 278: return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
1.41 markus 279: }
1.1 deraadt 280:
1.52 markus 281:
282: /* Close all channel fd/socket. */
283:
284: void
285: channel_close_fds(Channel *c)
286: {
287: if (c->sock != -1) {
288: close(c->sock);
289: c->sock = -1;
290: }
291: if (c->rfd != -1) {
292: close(c->rfd);
293: c->rfd = -1;
294: }
295: if (c->wfd != -1) {
296: close(c->wfd);
297: c->wfd = -1;
298: }
299: if (c->efd != -1) {
300: close(c->efd);
301: c->efd = -1;
302: }
303: }
304:
305: /* Free the channel and close its fd/socket. */
1.1 deraadt 306:
1.49 markus 307: void
1.41 markus 308: channel_free(int id)
1.1 deraadt 309: {
1.41 markus 310: Channel *c = channel_lookup(id);
1.79 markus 311: char *s = channel_open_message();
312:
1.41 markus 313: if (c == NULL)
314: packet_disconnect("channel free: bad local channel %d", id);
1.79 markus 315: debug("channel_free: channel %d: status: %s", id, s);
316: xfree(s);
317:
1.44 markus 318: if (c->dettach_user != NULL) {
319: debug("channel_free: channel %d: dettaching channel user", id);
320: c->dettach_user(c->self, NULL);
321: }
1.54 markus 322: if (c->sock != -1)
323: shutdown(c->sock, SHUT_RDWR);
1.52 markus 324: channel_close_fds(c);
1.41 markus 325: buffer_free(&c->input);
326: buffer_free(&c->output);
327: buffer_free(&c->extended);
328: c->type = SSH_CHANNEL_FREE;
329: if (c->remote_name) {
330: xfree(c->remote_name);
331: c->remote_name = NULL;
1.25 markus 332: }
1.1 deraadt 333: }
334:
1.27 markus 335: /*
1.41 markus 336: * 'channel_pre*' are called just before select() to add any bits relevant to
337: * channels in the select bitmasks.
338: */
339: /*
340: * 'channel_post*': perform any appropriate operations for channels which
341: * have events pending.
1.27 markus 342: */
1.41 markus 343: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
344: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
345: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
346:
347: void
348: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
349: {
350: FD_SET(c->sock, readset);
351: }
352:
353: void
1.75 markus 354: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
355: {
356: debug3("channel %d: waiting for connection", c->self);
357: FD_SET(c->sock, writeset);
358: }
359:
360: void
1.41 markus 361: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
362: {
363: if (buffer_len(&c->input) < packet_get_maxsize())
364: FD_SET(c->sock, readset);
365: if (buffer_len(&c->output) > 0)
366: FD_SET(c->sock, writeset);
367: }
1.1 deraadt 368:
1.41 markus 369: void
370: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
371: {
372: /* test whether sockets are 'alive' for read/write */
373: if (c->istate == CHAN_INPUT_OPEN)
374: if (buffer_len(&c->input) < packet_get_maxsize())
375: FD_SET(c->sock, readset);
376: if (c->ostate == CHAN_OUTPUT_OPEN ||
377: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
378: if (buffer_len(&c->output) > 0) {
379: FD_SET(c->sock, writeset);
380: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
381: chan_obuf_empty(c);
382: }
383: }
384: }
385:
386: void
1.44 markus 387: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
388: {
389: if (c->istate == CHAN_INPUT_OPEN &&
390: c->remote_window > 0 &&
391: buffer_len(&c->input) < c->remote_window)
392: FD_SET(c->rfd, readset);
393: if (c->ostate == CHAN_OUTPUT_OPEN ||
394: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
395: if (buffer_len(&c->output) > 0) {
396: FD_SET(c->wfd, writeset);
397: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
398: chan_obuf_empty(c);
399: }
400: }
401: /** XXX check close conditions, too */
402: if (c->efd != -1) {
403: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
404: buffer_len(&c->extended) > 0)
405: FD_SET(c->efd, writeset);
406: else if (c->extended_usage == CHAN_EXTENDED_READ &&
407: buffer_len(&c->extended) < c->remote_window)
408: FD_SET(c->efd, readset);
409: }
410: }
411:
412: void
1.41 markus 413: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
414: {
415: if (buffer_len(&c->input) == 0) {
416: packet_start(SSH_MSG_CHANNEL_CLOSE);
417: packet_put_int(c->remote_id);
418: packet_send();
419: c->type = SSH_CHANNEL_CLOSED;
420: debug("Closing channel %d after input drain.", c->self);
421: }
422: }
423:
424: void
425: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
426: {
427: if (buffer_len(&c->output) == 0)
428: channel_free(c->self);
1.49 markus 429: else
1.41 markus 430: FD_SET(c->sock, writeset);
431: }
432:
433: /*
434: * This is a special state for X11 authentication spoofing. An opened X11
435: * connection (when authentication spoofing is being done) remains in this
436: * state until the first packet has been completely read. The authentication
437: * data in that packet is then substituted by the real data if it matches the
438: * fake data, and the channel is put into normal mode.
1.51 markus 439: * XXX All this happens at the client side.
1.41 markus 440: */
441: int
442: x11_open_helper(Channel *c)
1.1 deraadt 443: {
1.77 markus 444: u_char *ucp;
445: u_int proto_len, data_len;
1.25 markus 446:
1.41 markus 447: /* Check if the fixed size part of the packet is in buffer. */
448: if (buffer_len(&c->output) < 12)
449: return 0;
450:
451: /* Parse the lengths of variable-length fields. */
1.77 markus 452: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 453: if (ucp[0] == 0x42) { /* Byte order MSB first. */
454: proto_len = 256 * ucp[6] + ucp[7];
455: data_len = 256 * ucp[8] + ucp[9];
456: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
457: proto_len = ucp[6] + 256 * ucp[7];
458: data_len = ucp[8] + 256 * ucp[9];
459: } else {
460: debug("Initial X11 packet contains bad byte order byte: 0x%x",
461: ucp[0]);
462: return -1;
463: }
464:
465: /* Check if the whole packet is in buffer. */
466: if (buffer_len(&c->output) <
467: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
468: return 0;
469:
470: /* Check if authentication protocol matches. */
471: if (proto_len != strlen(x11_saved_proto) ||
472: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
473: debug("X11 connection uses different authentication protocol.");
474: return -1;
475: }
476: /* Check if authentication data matches our fake data. */
477: if (data_len != x11_fake_data_len ||
478: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
479: x11_fake_data, x11_fake_data_len) != 0) {
480: debug("X11 auth data does not match fake data.");
481: return -1;
482: }
483: /* Check fake data length */
484: if (x11_fake_data_len != x11_saved_data_len) {
485: error("X11 fake_data_len %d != saved_data_len %d",
486: x11_fake_data_len, x11_saved_data_len);
487: return -1;
488: }
489: /*
490: * Received authentication protocol and data match
491: * our fake data. Substitute the fake data with real
492: * data.
493: */
494: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
495: x11_saved_data, x11_saved_data_len);
496: return 1;
497: }
498:
499: void
500: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
501: {
502: int ret = x11_open_helper(c);
503: if (ret == 1) {
504: /* Start normal processing for the channel. */
505: c->type = SSH_CHANNEL_OPEN;
1.47 markus 506: channel_pre_open_13(c, readset, writeset);
1.41 markus 507: } else if (ret == -1) {
508: /*
509: * We have received an X11 connection that has bad
510: * authentication information.
511: */
1.98 millert 512: log("X11 connection rejected because of wrong authentication.");
1.41 markus 513: buffer_clear(&c->input);
514: buffer_clear(&c->output);
515: close(c->sock);
516: c->sock = -1;
517: c->type = SSH_CHANNEL_CLOSED;
518: packet_start(SSH_MSG_CHANNEL_CLOSE);
519: packet_put_int(c->remote_id);
520: packet_send();
521: }
522: }
1.25 markus 523:
1.41 markus 524: void
1.51 markus 525: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 526: {
527: int ret = x11_open_helper(c);
528: if (ret == 1) {
529: c->type = SSH_CHANNEL_OPEN;
1.57 markus 530: if (compat20)
531: channel_pre_open_20(c, readset, writeset);
532: else
533: channel_pre_open_15(c, readset, writeset);
1.41 markus 534: } else if (ret == -1) {
535: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 536: chan_read_failed(c); /** force close? */
1.41 markus 537: chan_write_failed(c);
538: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
539: }
540: }
1.25 markus 541:
1.41 markus 542: /* This is our fake X11 server socket. */
543: void
544: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
545: {
546: struct sockaddr addr;
547: int newsock, newch;
548: socklen_t addrlen;
1.85 markus 549: char buf[16384], *remote_ipaddr;
1.51 markus 550: int remote_port;
1.25 markus 551:
1.41 markus 552: if (FD_ISSET(c->sock, readset)) {
553: debug("X11 connection requested.");
554: addrlen = sizeof(addr);
555: newsock = accept(c->sock, &addr, &addrlen);
556: if (newsock < 0) {
557: error("accept: %.100s", strerror(errno));
558: return;
559: }
1.85 markus 560: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 561: remote_port = get_peer_port(newsock);
1.41 markus 562: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 563: remote_ipaddr, remote_port);
1.51 markus 564:
565: newch = channel_new("x11",
566: SSH_CHANNEL_OPENING, newsock, newsock, -1,
567: c->local_window_max, c->local_maxpacket,
1.71 markus 568: 0, xstrdup(buf), 1);
1.51 markus 569: if (compat20) {
570: packet_start(SSH2_MSG_CHANNEL_OPEN);
571: packet_put_cstring("x11");
572: packet_put_int(newch);
573: packet_put_int(c->local_window_max);
574: packet_put_int(c->local_maxpacket);
1.85 markus 575: /* originator ipaddr and port */
576: packet_put_cstring(remote_ipaddr);
1.57 markus 577: if (datafellows & SSH_BUG_X11FWD) {
578: debug("ssh2 x11 bug compat mode");
579: } else {
580: packet_put_int(remote_port);
581: }
1.51 markus 582: packet_send();
583: } else {
584: packet_start(SSH_SMSG_X11_OPEN);
585: packet_put_int(newch);
586: if (have_hostname_in_open)
587: packet_put_string(buf, strlen(buf));
588: packet_send();
589: }
1.85 markus 590: xfree(remote_ipaddr);
1.41 markus 591: }
592: }
1.25 markus 593:
1.41 markus 594: /*
595: * This socket is listening for connections to a forwarded TCP/IP port.
596: */
597: void
598: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
599: {
600: struct sockaddr addr;
601: int newsock, newch;
602: socklen_t addrlen;
1.88 markus 603: char buf[1024], *remote_ipaddr, *rtype;
1.41 markus 604: int remote_port;
1.25 markus 605:
1.73 markus 606: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
607: "forwarded-tcpip" : "direct-tcpip";
608:
1.41 markus 609: if (FD_ISSET(c->sock, readset)) {
610: debug("Connection to port %d forwarding "
611: "to %.100s port %d requested.",
612: c->listening_port, c->path, c->host_port);
613: addrlen = sizeof(addr);
614: newsock = accept(c->sock, &addr, &addrlen);
615: if (newsock < 0) {
616: error("accept: %.100s", strerror(errno));
617: return;
618: }
1.88 markus 619: remote_ipaddr = get_peer_ipaddr(newsock);
1.41 markus 620: remote_port = get_peer_port(newsock);
621: snprintf(buf, sizeof buf,
622: "listen port %d for %.100s port %d, "
623: "connect from %.200s port %d",
624: c->listening_port, c->path, c->host_port,
1.88 markus 625: remote_ipaddr, remote_port);
1.73 markus 626:
627: newch = channel_new(rtype,
1.41 markus 628: SSH_CHANNEL_OPENING, newsock, newsock, -1,
629: c->local_window_max, c->local_maxpacket,
1.71 markus 630: 0, xstrdup(buf), 1);
1.44 markus 631: if (compat20) {
632: packet_start(SSH2_MSG_CHANNEL_OPEN);
1.73 markus 633: packet_put_cstring(rtype);
1.44 markus 634: packet_put_int(newch);
635: packet_put_int(c->local_window_max);
636: packet_put_int(c->local_maxpacket);
1.73 markus 637: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
638: /* listen address, port */
639: packet_put_string(c->path, strlen(c->path));
640: packet_put_int(c->listening_port);
641: } else {
642: /* target host, port */
643: packet_put_string(c->path, strlen(c->path));
644: packet_put_int(c->host_port);
645: }
1.48 markus 646: /* originator host and port */
1.88 markus 647: packet_put_cstring(remote_ipaddr);
1.44 markus 648: packet_put_int(remote_port);
649: packet_send();
650: } else {
651: packet_start(SSH_MSG_PORT_OPEN);
652: packet_put_int(newch);
653: packet_put_string(c->path, strlen(c->path));
654: packet_put_int(c->host_port);
655: if (have_hostname_in_open) {
656: packet_put_string(buf, strlen(buf));
657: }
658: packet_send();
1.41 markus 659: }
1.88 markus 660: xfree(remote_ipaddr);
1.41 markus 661: }
662: }
1.25 markus 663:
1.41 markus 664: /*
665: * This is the authentication agent socket listening for connections from
666: * clients.
667: */
668: void
669: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
670: {
671: struct sockaddr addr;
672: int newsock, newch;
673: socklen_t addrlen;
1.25 markus 674:
1.41 markus 675: if (FD_ISSET(c->sock, readset)) {
676: addrlen = sizeof(addr);
677: newsock = accept(c->sock, &addr, &addrlen);
678: if (newsock < 0) {
679: error("accept from auth socket: %.100s", strerror(errno));
680: return;
681: }
1.73 markus 682: newch = channel_new("accepted auth socket",
683: SSH_CHANNEL_OPENING, newsock, newsock, -1,
684: c->local_window_max, c->local_maxpacket,
685: 0, xstrdup("accepted auth socket"), 1);
686: if (compat20) {
687: packet_start(SSH2_MSG_CHANNEL_OPEN);
688: packet_put_cstring("auth-agent@openssh.com");
689: packet_put_int(newch);
690: packet_put_int(c->local_window_max);
691: packet_put_int(c->local_maxpacket);
692: } else {
693: packet_start(SSH_SMSG_AGENT_OPEN);
694: packet_put_int(newch);
695: }
1.41 markus 696: packet_send();
697: }
698: }
1.25 markus 699:
1.75 markus 700: void
701: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
702: {
703: if (FD_ISSET(c->sock, writeset)) {
704: int err = 0;
705: int sz = sizeof(err);
706: c->type = SSH_CHANNEL_OPEN;
1.89 stevesk 707: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
1.75 markus 708: debug("getsockopt SO_ERROR failed");
709: } else {
710: if (err == 0) {
711: debug("channel %d: connected)", c->self);
712: } else {
713: debug("channel %d: not connected: %s",
714: c->self, strerror(err));
715: chan_read_failed(c);
716: chan_write_failed(c);
717: }
718: }
719: }
720: }
721:
1.41 markus 722: int
723: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
724: {
725: char buf[16*1024];
726: int len;
1.25 markus 727:
1.41 markus 728: if (c->rfd != -1 &&
729: FD_ISSET(c->rfd, readset)) {
730: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 731: if (len < 0 && (errno == EINTR || errno == EAGAIN))
732: return 1;
1.41 markus 733: if (len <= 0) {
1.51 markus 734: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 735: c->self, c->rfd, len);
1.25 markus 736: if (compat13) {
1.41 markus 737: buffer_consume(&c->output, buffer_len(&c->output));
738: c->type = SSH_CHANNEL_INPUT_DRAINING;
739: debug("Channel %d status set to input draining.", c->self);
1.25 markus 740: } else {
1.41 markus 741: chan_read_failed(c);
1.25 markus 742: }
1.41 markus 743: return -1;
744: }
1.65 markus 745: if(c->input_filter != NULL) {
1.66 markus 746: if (c->input_filter(c, buf, len) == -1) {
1.65 markus 747: debug("filter stops channel %d", c->self);
748: chan_read_failed(c);
749: }
750: } else {
751: buffer_append(&c->input, buf, len);
752: }
1.41 markus 753: }
754: return 1;
755: }
756: int
757: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
758: {
1.95 markus 759: struct termios tio;
1.41 markus 760: int len;
1.25 markus 761:
1.41 markus 762: /* Send buffered output data to the socket. */
763: if (c->wfd != -1 &&
764: FD_ISSET(c->wfd, writeset) &&
765: buffer_len(&c->output) > 0) {
766: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 767: buffer_len(&c->output));
768: if (len < 0 && (errno == EINTR || errno == EAGAIN))
769: return 1;
1.41 markus 770: if (len <= 0) {
771: if (compat13) {
772: buffer_consume(&c->output, buffer_len(&c->output));
773: debug("Channel %d status set to input draining.", c->self);
774: c->type = SSH_CHANNEL_INPUT_DRAINING;
775: } else {
776: chan_write_failed(c);
777: }
778: return -1;
1.91 markus 779: }
780: if (compat20 && c->isatty) {
781: if (tcgetattr(c->wfd, &tio) == 0 &&
782: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
783: /*
784: * Simulate echo to reduce the impact of
1.96 markus 785: * traffic analysis. We need to match the
1.95 markus 786: * size of a SSH2_MSG_CHANNEL_DATA message
787: * (4 byte channel id + data)
1.91 markus 788: */
1.95 markus 789: packet_send_ignore(4 + len);
1.91 markus 790: packet_send();
791: }
1.25 markus 792: }
1.41 markus 793: buffer_consume(&c->output, len);
1.44 markus 794: if (compat20 && len > 0) {
795: c->local_consumed += len;
796: }
797: }
798: return 1;
799: }
800: int
801: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
802: {
803: char buf[16*1024];
804: int len;
805:
1.45 markus 806: /** XXX handle drain efd, too */
1.44 markus 807: if (c->efd != -1) {
808: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
809: FD_ISSET(c->efd, writeset) &&
810: buffer_len(&c->extended) > 0) {
811: len = write(c->efd, buffer_ptr(&c->extended),
812: buffer_len(&c->extended));
1.70 markus 813: debug2("channel %d: written %d to efd %d",
1.44 markus 814: c->self, len, c->efd);
1.93 markus 815: if (len < 0 && (errno == EINTR || errno == EAGAIN))
816: return 1;
817: if (len <= 0) {
818: debug2("channel %d: closing write-efd %d",
819: c->self, c->efd);
820: close(c->efd);
821: c->efd = -1;
822: } else {
1.44 markus 823: buffer_consume(&c->extended, len);
824: c->local_consumed += len;
825: }
826: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
827: FD_ISSET(c->efd, readset)) {
828: len = read(c->efd, buf, sizeof(buf));
1.70 markus 829: debug2("channel %d: read %d from efd %d",
1.44 markus 830: c->self, len, c->efd);
1.93 markus 831: if (len < 0 && (errno == EINTR || errno == EAGAIN))
832: return 1;
833: if (len <= 0) {
834: debug2("channel %d: closing read-efd %d",
1.45 markus 835: c->self, c->efd);
836: close(c->efd);
837: c->efd = -1;
1.93 markus 838: } else {
1.44 markus 839: buffer_append(&c->extended, buf, len);
1.93 markus 840: }
1.44 markus 841: }
842: }
843: return 1;
844: }
845: int
1.93 markus 846: channel_check_window(Channel *c)
1.44 markus 847: {
1.46 markus 848: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 849: c->local_window < c->local_window_max/2 &&
850: c->local_consumed > 0) {
851: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
852: packet_put_int(c->remote_id);
853: packet_put_int(c->local_consumed);
854: packet_send();
1.70 markus 855: debug2("channel %d: window %d sent adjust %d",
1.44 markus 856: c->self, c->local_window,
857: c->local_consumed);
858: c->local_window += c->local_consumed;
859: c->local_consumed = 0;
1.1 deraadt 860: }
1.41 markus 861: return 1;
1.1 deraadt 862: }
863:
1.41 markus 864: void
865: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
866: {
867: channel_handle_rfd(c, readset, writeset);
868: channel_handle_wfd(c, readset, writeset);
869: }
1.1 deraadt 870:
1.41 markus 871: void
1.44 markus 872: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
873: {
874: channel_handle_rfd(c, readset, writeset);
875: channel_handle_wfd(c, readset, writeset);
876: channel_handle_efd(c, readset, writeset);
1.93 markus 877:
878: channel_check_window(c);
1.44 markus 879: }
880:
881: void
1.41 markus 882: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 883: {
1.41 markus 884: int len;
885: /* Send buffered output data to the socket. */
886: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
887: len = write(c->sock, buffer_ptr(&c->output),
888: buffer_len(&c->output));
889: if (len <= 0)
890: buffer_consume(&c->output, buffer_len(&c->output));
891: else
892: buffer_consume(&c->output, len);
893: }
894: }
1.25 markus 895:
1.41 markus 896: void
1.44 markus 897: channel_handler_init_20(void)
898: {
899: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 900: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 901: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 902: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 903: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 904: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 905: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.44 markus 906:
907: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
908: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 909: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 910: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 911: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 912: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.44 markus 913: }
914:
915: void
1.41 markus 916: channel_handler_init_13(void)
917: {
918: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
919: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
920: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
921: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
922: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
923: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
924: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 925: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 926:
1.41 markus 927: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
928: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
929: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
930: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
931: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 932: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 933: }
1.25 markus 934:
1.41 markus 935: void
936: channel_handler_init_15(void)
937: {
938: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 939: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 940: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
941: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
942: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 943: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 944:
1.41 markus 945: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
946: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
947: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
948: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 949: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 950: }
1.27 markus 951:
1.41 markus 952: void
953: channel_handler_init(void)
954: {
955: int i;
956: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
957: channel_pre[i] = NULL;
958: channel_post[i] = NULL;
959: }
1.44 markus 960: if (compat20)
961: channel_handler_init_20();
962: else if (compat13)
1.41 markus 963: channel_handler_init_13();
964: else
965: channel_handler_init_15();
966: }
1.25 markus 967:
1.49 markus 968: void
1.41 markus 969: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
970: {
971: static int did_init = 0;
972: int i;
973: Channel *c;
1.25 markus 974:
1.41 markus 975: if (!did_init) {
976: channel_handler_init();
977: did_init = 1;
978: }
979: for (i = 0; i < channels_alloc; i++) {
980: c = &channels[i];
981: if (c->type == SSH_CHANNEL_FREE)
982: continue;
983: if (ftab[c->type] == NULL)
1.25 markus 984: continue;
1.41 markus 985: (*ftab[c->type])(c, readset, writeset);
1.93 markus 986: if (chan_is_dead(c)) {
987: /*
988: * we have to remove the fd's from the select mask
989: * before the channels are free'd and the fd's are
990: * closed
991: */
992: if (c->wfd != -1)
993: FD_CLR(c->wfd, writeset);
994: if (c->rfd != -1)
995: FD_CLR(c->rfd, readset);
996: if (c->efd != -1) {
997: if (c->extended_usage == CHAN_EXTENDED_READ)
998: FD_CLR(c->efd, readset);
999: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1000: FD_CLR(c->efd, writeset);
1001: }
1002: channel_free(c->self);
1003: }
1.1 deraadt 1004: }
1005: }
1006:
1.49 markus 1007: void
1.100 markus 1008: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1009: int rekeying)
1.41 markus 1010: {
1.84 markus 1011: int n;
1012: u_int sz;
1013:
1014: n = MAX(*maxfdp, channel_max_fd);
1015:
1016: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1017: if (*readsetp == NULL || n > *maxfdp) {
1018: if (*readsetp)
1019: xfree(*readsetp);
1020: if (*writesetp)
1021: xfree(*writesetp);
1022: *readsetp = xmalloc(sz);
1023: *writesetp = xmalloc(sz);
1024: *maxfdp = n;
1025: }
1026: memset(*readsetp, 0, sz);
1027: memset(*writesetp, 0, sz);
1028:
1.100 markus 1029: if (!rekeying)
1030: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1031: }
1032:
1.49 markus 1033: void
1.41 markus 1034: channel_after_select(fd_set * readset, fd_set * writeset)
1035: {
1036: channel_handler(channel_post, readset, writeset);
1037: }
1038:
1.84 markus 1039: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1040:
1.49 markus 1041: void
1.25 markus 1042: channel_output_poll()
1.1 deraadt 1043: {
1.25 markus 1044: int len, i;
1.41 markus 1045: Channel *c;
1.1 deraadt 1046:
1.25 markus 1047: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1048: c = &channels[i];
1.37 markus 1049:
1.27 markus 1050: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1051: if (compat13) {
1.41 markus 1052: if (c->type != SSH_CHANNEL_OPEN &&
1053: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1054: continue;
1055: } else {
1.41 markus 1056: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1057: continue;
1058: }
1.46 markus 1059: if (compat20 &&
1060: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1061: /* XXX is this true? */
1.97 markus 1062: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1063: continue;
1064: }
1.25 markus 1065:
1066: /* Get the amount of buffered data for this channel. */
1.93 markus 1067: if ((c->istate == CHAN_INPUT_OPEN ||
1068: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1069: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1070: /* Send some data for the other side over the secure connection. */
1.44 markus 1071: if (compat20) {
1072: if (len > c->remote_window)
1073: len = c->remote_window;
1074: if (len > c->remote_maxpacket)
1075: len = c->remote_maxpacket;
1.25 markus 1076: } else {
1.44 markus 1077: if (packet_is_interactive()) {
1078: if (len > 1024)
1079: len = 512;
1080: } else {
1081: /* Keep the packets at reasonable size. */
1082: if (len > packet_get_maxsize()/2)
1083: len = packet_get_maxsize()/2;
1084: }
1.25 markus 1085: }
1.41 markus 1086: if (len > 0) {
1.44 markus 1087: packet_start(compat20 ?
1088: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1089: packet_put_int(c->remote_id);
1090: packet_put_string(buffer_ptr(&c->input), len);
1091: packet_send();
1092: buffer_consume(&c->input, len);
1093: c->remote_window -= len;
1094: }
1095: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1096: if (compat13)
1097: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1098: /*
1099: * input-buffer is empty and read-socket shutdown:
1100: * tell peer, that we will not send more data: send IEOF
1101: */
1.41 markus 1102: chan_ibuf_empty(c);
1.25 markus 1103: }
1.44 markus 1104: /* Send extended data, i.e. stderr */
1105: if (compat20 &&
1106: c->remote_window > 0 &&
1107: (len = buffer_len(&c->extended)) > 0 &&
1108: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1109: debug2("channel %d: rwin %d elen %d euse %d",
1110: c->self, c->remote_window, buffer_len(&c->extended),
1111: c->extended_usage);
1.44 markus 1112: if (len > c->remote_window)
1113: len = c->remote_window;
1114: if (len > c->remote_maxpacket)
1115: len = c->remote_maxpacket;
1116: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1117: packet_put_int(c->remote_id);
1118: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1119: packet_put_string(buffer_ptr(&c->extended), len);
1120: packet_send();
1121: buffer_consume(&c->extended, len);
1122: c->remote_window -= len;
1.93 markus 1123: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1124: }
1.25 markus 1125: }
1.1 deraadt 1126: }
1127:
1.27 markus 1128: /*
1129: * This is called when a packet of type CHANNEL_DATA has just been received.
1130: * The message type has already been consumed, but channel number and data is
1131: * still there.
1132: */
1.1 deraadt 1133:
1.49 markus 1134: void
1.69 markus 1135: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1136: {
1.37 markus 1137: int id;
1.25 markus 1138: char *data;
1.77 markus 1139: u_int data_len;
1.41 markus 1140: Channel *c;
1.25 markus 1141:
1142: /* Get the channel number and verify it. */
1.37 markus 1143: id = packet_get_int();
1.41 markus 1144: c = channel_lookup(id);
1145: if (c == NULL)
1.37 markus 1146: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1147:
1148: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1149: if (c->type != SSH_CHANNEL_OPEN &&
1150: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1151: return;
1152:
1153: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1154: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1155: return;
1156:
1157: /* Get the data. */
1158: data = packet_get_string(&data_len);
1.48 markus 1159: packet_done();
1.41 markus 1160:
1.44 markus 1161: if (compat20){
1162: if (data_len > c->local_maxpacket) {
1163: log("channel %d: rcvd big packet %d, maxpack %d",
1164: c->self, data_len, c->local_maxpacket);
1165: }
1166: if (data_len > c->local_window) {
1167: log("channel %d: rcvd too much data %d, win %d",
1168: c->self, data_len, c->local_window);
1169: xfree(data);
1170: return;
1171: }
1172: c->local_window -= data_len;
1173: }else{
1174: packet_integrity_check(plen, 4 + 4 + data_len, type);
1175: }
1.41 markus 1176: buffer_append(&c->output, data, data_len);
1.25 markus 1177: xfree(data);
1.1 deraadt 1178: }
1.49 markus 1179: void
1.69 markus 1180: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1181: {
1182: int id;
1183: int tcode;
1184: char *data;
1.77 markus 1185: u_int data_len;
1.44 markus 1186: Channel *c;
1187:
1188: /* Get the channel number and verify it. */
1189: id = packet_get_int();
1190: c = channel_lookup(id);
1191:
1192: if (c == NULL)
1193: packet_disconnect("Received extended_data for bad channel %d.", id);
1194: if (c->type != SSH_CHANNEL_OPEN) {
1195: log("channel %d: ext data for non open", id);
1196: return;
1197: }
1198: tcode = packet_get_int();
1199: if (c->efd == -1 ||
1200: c->extended_usage != CHAN_EXTENDED_WRITE ||
1201: tcode != SSH2_EXTENDED_DATA_STDERR) {
1202: log("channel %d: bad ext data", c->self);
1203: return;
1204: }
1205: data = packet_get_string(&data_len);
1.48 markus 1206: packet_done();
1.44 markus 1207: if (data_len > c->local_window) {
1208: log("channel %d: rcvd too much extended_data %d, win %d",
1209: c->self, data_len, c->local_window);
1210: xfree(data);
1211: return;
1212: }
1.70 markus 1213: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1214: c->local_window -= data_len;
1215: buffer_append(&c->extended, data, data_len);
1216: xfree(data);
1217: }
1218:
1.1 deraadt 1219:
1.27 markus 1220: /*
1221: * Returns true if no channel has too much buffered data, and false if one or
1222: * more channel is overfull.
1223: */
1.1 deraadt 1224:
1.49 markus 1225: int
1.25 markus 1226: channel_not_very_much_buffered_data()
1.1 deraadt 1227: {
1.77 markus 1228: u_int i;
1.41 markus 1229: Channel *c;
1.25 markus 1230:
1231: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1232: c = &channels[i];
1233: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1234: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1235: debug("channel %d: big input buffer %d",
1236: c->self, buffer_len(&c->input));
1.25 markus 1237: return 0;
1.41 markus 1238: }
1239: if (buffer_len(&c->output) > packet_get_maxsize()) {
1240: debug("channel %d: big output buffer %d",
1241: c->self, buffer_len(&c->output));
1.25 markus 1242: return 0;
1.41 markus 1243: }
1.25 markus 1244: }
1.1 deraadt 1245: }
1.25 markus 1246: return 1;
1.1 deraadt 1247: }
1248:
1.49 markus 1249: void
1.69 markus 1250: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1251: {
1252: int id;
1253: Channel *c;
1254:
1255: packet_integrity_check(plen, 4, type);
1256:
1257: id = packet_get_int();
1258: c = channel_lookup(id);
1259: if (c == NULL)
1260: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1261: chan_rcvd_ieof(c);
1262: }
1.1 deraadt 1263:
1.49 markus 1264: void
1.69 markus 1265: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1266: {
1.41 markus 1267: int id;
1268: Channel *c;
1.1 deraadt 1269:
1.41 markus 1270: packet_integrity_check(plen, 4, type);
1271:
1272: id = packet_get_int();
1273: c = channel_lookup(id);
1274: if (c == NULL)
1275: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1276:
1277: /*
1278: * Send a confirmation that we have closed the channel and no more
1279: * data is coming for it.
1280: */
1.25 markus 1281: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1282: packet_put_int(c->remote_id);
1.25 markus 1283: packet_send();
1284:
1.27 markus 1285: /*
1286: * If the channel is in closed state, we have sent a close request,
1287: * and the other side will eventually respond with a confirmation.
1288: * Thus, we cannot free the channel here, because then there would be
1289: * no-one to receive the confirmation. The channel gets freed when
1290: * the confirmation arrives.
1291: */
1.41 markus 1292: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1293: /*
1294: * Not a closed channel - mark it as draining, which will
1295: * cause it to be freed later.
1296: */
1.41 markus 1297: buffer_consume(&c->input, buffer_len(&c->input));
1298: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1299: }
1.1 deraadt 1300: }
1301:
1.41 markus 1302: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1303: void
1.69 markus 1304: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1305: {
1306: int id = packet_get_int();
1307: Channel *c = channel_lookup(id);
1308: packet_integrity_check(plen, 4, type);
1309: if (c == NULL)
1310: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1311: chan_rcvd_oclose(c);
1312: }
1.1 deraadt 1313:
1.49 markus 1314: void
1.69 markus 1315: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1316: {
1.41 markus 1317: int id = packet_get_int();
1318: Channel *c = channel_lookup(id);
1.1 deraadt 1319:
1.48 markus 1320: packet_done();
1.41 markus 1321: if (c == NULL)
1322: packet_disconnect("Received close confirmation for "
1323: "out-of-range channel %d.", id);
1324: if (c->type != SSH_CHANNEL_CLOSED)
1325: packet_disconnect("Received close confirmation for "
1326: "non-closed channel %d (type %d).", id, c->type);
1327: channel_free(c->self);
1.1 deraadt 1328: }
1329:
1.49 markus 1330: void
1.69 markus 1331: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1332: {
1.41 markus 1333: int id, remote_id;
1334: Channel *c;
1.1 deraadt 1335:
1.44 markus 1336: if (!compat20)
1337: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1338:
1.41 markus 1339: id = packet_get_int();
1340: c = channel_lookup(id);
1.25 markus 1341:
1.41 markus 1342: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1343: packet_disconnect("Received open confirmation for "
1344: "non-opening channel %d.", id);
1345: remote_id = packet_get_int();
1.27 markus 1346: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1347: c->remote_id = remote_id;
1348: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1349:
1350: if (compat20) {
1351: c->remote_window = packet_get_int();
1352: c->remote_maxpacket = packet_get_int();
1.48 markus 1353: packet_done();
1.44 markus 1354: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1355: debug2("callback start");
1.44 markus 1356: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1357: debug2("callback done");
1.44 markus 1358: }
1359: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1360: c->remote_window, c->remote_maxpacket);
1361: }
1.1 deraadt 1362: }
1363:
1.49 markus 1364: void
1.69 markus 1365: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1366: {
1.86 markus 1367: int id, reason;
1368: char *msg = NULL, *lang = NULL;
1.41 markus 1369: Channel *c;
1370:
1.44 markus 1371: if (!compat20)
1372: packet_integrity_check(plen, 4, type);
1.41 markus 1373:
1374: id = packet_get_int();
1375: c = channel_lookup(id);
1.25 markus 1376:
1.41 markus 1377: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1378: packet_disconnect("Received open failure for "
1379: "non-opening channel %d.", id);
1.44 markus 1380: if (compat20) {
1.86 markus 1381: reason = packet_get_int();
1382: if (packet_remaining() > 0) {
1383: msg = packet_get_string(NULL);
1384: lang = packet_get_string(NULL);
1385: }
1.48 markus 1386: packet_done();
1.86 markus 1387: log("channel_open_failure: %d: reason %d %s", id,
1388: reason, msg ? msg : "<no additional info>");
1389: if (msg != NULL)
1390: xfree(msg);
1391: if (lang != NULL)
1392: xfree(lang);
1.44 markus 1393: }
1.25 markus 1394: /* Free the channel. This will also close the socket. */
1.41 markus 1395: channel_free(id);
1.1 deraadt 1396: }
1397:
1.44 markus 1398: void
1.69 markus 1399: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1400: {
1401: int id;
1402: Channel *c;
1403:
1404: id = packet_get_int();
1405: c = channel_lookup(id);
1406:
1407: if (c == NULL ||
1408: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1409: packet_disconnect("Received request for "
1410: "non-open channel %d.", id);
1411: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1412: debug2("callback start");
1.44 markus 1413: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1414: debug2("callback done");
1.44 markus 1415: } else {
1416: char *service = packet_get_string(NULL);
1.94 markus 1417: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1418: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1419: xfree(service);
1420: }
1421: }
1422:
1.49 markus 1423: void
1.69 markus 1424: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1425: {
1426: Channel *c;
1427: int id, adjust;
1428:
1429: if (!compat20)
1430: return;
1431:
1432: /* Get the channel number and verify it. */
1433: id = packet_get_int();
1434: c = channel_lookup(id);
1435:
1436: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1437: log("Received window adjust for "
1438: "non-open channel %d.", id);
1439: return;
1440: }
1441: adjust = packet_get_int();
1.48 markus 1442: packet_done();
1.70 markus 1443: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1444: c->remote_window += adjust;
1445: }
1446:
1.27 markus 1447: /*
1448: * Stops listening for channels, and removes any unix domain sockets that we
1449: * might have.
1450: */
1.1 deraadt 1451:
1.49 markus 1452: void
1.25 markus 1453: channel_stop_listening()
1.1 deraadt 1454: {
1.25 markus 1455: int i;
1456: for (i = 0; i < channels_alloc; i++) {
1457: switch (channels[i].type) {
1458: case SSH_CHANNEL_AUTH_SOCKET:
1459: close(channels[i].sock);
1.76 markus 1460: unlink(channels[i].path);
1.25 markus 1461: channel_free(i);
1462: break;
1463: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1464: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1465: case SSH_CHANNEL_X11_LISTENER:
1466: close(channels[i].sock);
1467: channel_free(i);
1468: break;
1469: default:
1470: break;
1471: }
1.1 deraadt 1472: }
1473: }
1474:
1.27 markus 1475: /*
1.52 markus 1476: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1477: * descriptors after a fork.
1478: */
1.1 deraadt 1479:
1.49 markus 1480: void
1.25 markus 1481: channel_close_all()
1.1 deraadt 1482: {
1.25 markus 1483: int i;
1.52 markus 1484: for (i = 0; i < channels_alloc; i++)
1.25 markus 1485: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1486: channel_close_fds(&channels[i]);
1.1 deraadt 1487: }
1488:
1489: /* Returns true if any channel is still open. */
1490:
1.49 markus 1491: int
1.25 markus 1492: channel_still_open()
1.1 deraadt 1493: {
1.77 markus 1494: u_int i;
1.25 markus 1495: for (i = 0; i < channels_alloc; i++)
1496: switch (channels[i].type) {
1497: case SSH_CHANNEL_FREE:
1498: case SSH_CHANNEL_X11_LISTENER:
1499: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1500: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1501: case SSH_CHANNEL_CLOSED:
1502: case SSH_CHANNEL_AUTH_SOCKET:
1.75 markus 1503: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1504: continue;
1.44 markus 1505: case SSH_CHANNEL_LARVAL:
1506: if (!compat20)
1507: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1508: continue;
1.25 markus 1509: case SSH_CHANNEL_OPENING:
1510: case SSH_CHANNEL_OPEN:
1511: case SSH_CHANNEL_X11_OPEN:
1512: return 1;
1513: case SSH_CHANNEL_INPUT_DRAINING:
1514: case SSH_CHANNEL_OUTPUT_DRAINING:
1515: if (!compat13)
1516: fatal("cannot happen: OUT_DRAIN");
1517: return 1;
1518: default:
1519: fatal("channel_still_open: bad channel type %d", channels[i].type);
1520: /* NOTREACHED */
1521: }
1522: return 0;
1.1 deraadt 1523: }
1524:
1.27 markus 1525: /*
1526: * Returns a message describing the currently open forwarded connections,
1527: * suitable for sending to the client. The message contains crlf pairs for
1528: * newlines.
1529: */
1.1 deraadt 1530:
1.25 markus 1531: char *
1532: channel_open_message()
1.1 deraadt 1533: {
1.25 markus 1534: Buffer buffer;
1535: int i;
1536: char buf[512], *cp;
1537:
1538: buffer_init(&buffer);
1539: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1540: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1541: for (i = 0; i < channels_alloc; i++) {
1542: Channel *c = &channels[i];
1543: switch (c->type) {
1544: case SSH_CHANNEL_FREE:
1545: case SSH_CHANNEL_X11_LISTENER:
1546: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1547: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1548: case SSH_CHANNEL_CLOSED:
1549: case SSH_CHANNEL_AUTH_SOCKET:
1550: continue;
1.44 markus 1551: case SSH_CHANNEL_LARVAL:
1.25 markus 1552: case SSH_CHANNEL_OPENING:
1.75 markus 1553: case SSH_CHANNEL_CONNECTING:
1.25 markus 1554: case SSH_CHANNEL_OPEN:
1555: case SSH_CHANNEL_X11_OPEN:
1556: case SSH_CHANNEL_INPUT_DRAINING:
1557: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1558: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1559: c->self, c->remote_name,
1560: c->type, c->remote_id,
1561: c->istate, buffer_len(&c->input),
1.41 markus 1562: c->ostate, buffer_len(&c->output),
1563: c->rfd, c->wfd);
1.25 markus 1564: buffer_append(&buffer, buf, strlen(buf));
1565: continue;
1566: default:
1.41 markus 1567: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1568: /* NOTREACHED */
1569: }
1570: }
1571: buffer_append(&buffer, "\0", 1);
1572: cp = xstrdup(buffer_ptr(&buffer));
1573: buffer_free(&buffer);
1574: return cp;
1.1 deraadt 1575: }
1576:
1.27 markus 1577: /*
1578: * Initiate forwarding of connections to local port "port" through the secure
1579: * channel to host:port from remote side.
1580: */
1.87 markus 1581: int
1.73 markus 1582: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1583: u_short port_to_connect, int gateway_ports)
1584: {
1.87 markus 1585: return channel_request_forwarding(
1.73 markus 1586: NULL, listen_port,
1587: host_to_connect, port_to_connect,
1588: gateway_ports, /*remote_fwd*/ 0);
1589: }
1.1 deraadt 1590:
1.73 markus 1591: /*
1592: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1593: * (SSH_CHANNEL_RPORT_LISTENER).
1594: */
1.87 markus 1595: int
1.73 markus 1596: channel_request_forwarding(
1597: const char *listen_address, u_short listen_port,
1598: const char *host_to_connect, u_short port_to_connect,
1599: int gateway_ports, int remote_fwd)
1.25 markus 1600: {
1.73 markus 1601: int success, ch, sock, on = 1, ctype;
1.35 markus 1602: struct addrinfo hints, *ai, *aitop;
1603: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1604: const char *host;
1.28 markus 1605: struct linger linger;
1.25 markus 1606:
1.87 markus 1607: success = 0;
1608:
1.73 markus 1609: if (remote_fwd) {
1610: host = listen_address;
1.89 stevesk 1611: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1612: } else {
1613: host = host_to_connect;
1614: ctype =SSH_CHANNEL_PORT_LISTENER;
1615: }
1616:
1.87 markus 1617: if (strlen(host) > sizeof(channels[0].path) - 1) {
1618: error("Forward host name too long.");
1619: return success;
1620: }
1.25 markus 1621:
1.73 markus 1622: /* XXX listen_address is currently ignored */
1.28 markus 1623: /*
1.35 markus 1624: * getaddrinfo returns a loopback address if the hostname is
1625: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1626: */
1.35 markus 1627: memset(&hints, 0, sizeof(hints));
1628: hints.ai_family = IPv4or6;
1629: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1630: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1631: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1632: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1633: packet_disconnect("getaddrinfo: fatal error");
1634:
1635: for (ai = aitop; ai; ai = ai->ai_next) {
1636: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1637: continue;
1638: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1639: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1640: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1641: continue;
1642: }
1643: /* Create a port to listen for the host. */
1644: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1645: if (sock < 0) {
1646: /* this is no error since kernel may not support ipv6 */
1647: verbose("socket: %.100s", strerror(errno));
1648: continue;
1649: }
1650: /*
1651: * Set socket options. We would like the socket to disappear
1652: * as soon as it has been closed for whatever reason.
1653: */
1654: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1655: linger.l_onoff = 1;
1656: linger.l_linger = 5;
1657: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1658: debug("Local forwarding listening on %s port %s.", ntop, strport);
1659:
1660: /* Bind the socket to the address. */
1661: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1662: /* address can be in use ipv6 address is already bound */
1663: verbose("bind: %.100s", strerror(errno));
1664: close(sock);
1665: continue;
1666: }
1667: /* Start listening for connections on the socket. */
1668: if (listen(sock, 5) < 0) {
1669: error("listen: %.100s", strerror(errno));
1670: close(sock);
1671: continue;
1672: }
1673: /* Allocate a channel number for the socket. */
1.73 markus 1674: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1675: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1676: 0, xstrdup("port listener"), 1);
1.35 markus 1677: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1678: channels[ch].host_port = port_to_connect;
1679: channels[ch].listening_port = listen_port;
1.35 markus 1680: success = 1;
1681: }
1682: if (success == 0)
1.87 markus 1683: error("channel_request_forwarding: cannot listen to port: %d",
1684: listen_port);
1.35 markus 1685: freeaddrinfo(aitop);
1.87 markus 1686: return success;
1.25 markus 1687: }
1.1 deraadt 1688:
1.27 markus 1689: /*
1690: * Initiate forwarding of connections to port "port" on remote host through
1691: * the secure channel to host:port from local side.
1692: */
1.1 deraadt 1693:
1.49 markus 1694: void
1.73 markus 1695: channel_request_remote_forwarding(u_short listen_port,
1696: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1697: {
1.73 markus 1698: int payload_len, type, success = 0;
1699:
1.25 markus 1700: /* Record locally that connection to this host/port is permitted. */
1701: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1702: fatal("channel_request_remote_forwarding: too many forwards");
1703:
1704: /* Send the forward request to the remote side. */
1.44 markus 1705: if (compat20) {
1706: const char *address_to_bind = "0.0.0.0";
1707: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1708: packet_put_cstring("tcpip-forward");
1709: packet_put_char(0); /* boolean: want reply */
1710: packet_put_cstring(address_to_bind);
1711: packet_put_int(listen_port);
1.73 markus 1712: packet_send();
1713: packet_write_wait();
1714: /* Assume that server accepts the request */
1715: success = 1;
1.44 markus 1716: } else {
1717: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1718: packet_put_int(listen_port);
1719: packet_put_cstring(host_to_connect);
1.44 markus 1720: packet_put_int(port_to_connect);
1721: packet_send();
1722: packet_write_wait();
1.73 markus 1723:
1724: /* Wait for response from the remote side. */
1725: type = packet_read(&payload_len);
1726: switch (type) {
1727: case SSH_SMSG_SUCCESS:
1728: success = 1;
1729: break;
1730: case SSH_SMSG_FAILURE:
1731: log("Warning: Server denied remote port forwarding.");
1732: break;
1733: default:
1734: /* Unknown packet */
1735: packet_disconnect("Protocol error for port forward request:"
1736: "received packet type %d.", type);
1737: }
1738: }
1739: if (success) {
1740: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1741: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1742: permitted_opens[num_permitted_opens].listen_port = listen_port;
1743: num_permitted_opens++;
1.44 markus 1744: }
1.1 deraadt 1745: }
1746:
1.27 markus 1747: /*
1748: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1749: * listening for the port, and sends back a success reply (or disconnect
1750: * message if there was an error). This never returns if there was an error.
1751: */
1.1 deraadt 1752:
1.49 markus 1753: void
1.56 markus 1754: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1755: {
1.31 markus 1756: u_short port, host_port;
1.25 markus 1757: char *hostname;
1.1 deraadt 1758:
1.25 markus 1759: /* Get arguments from the packet. */
1760: port = packet_get_int();
1761: hostname = packet_get_string(NULL);
1762: host_port = packet_get_int();
1763:
1.27 markus 1764: /*
1765: * Check that an unprivileged user is not trying to forward a
1766: * privileged port.
1767: */
1.25 markus 1768: if (port < IPPORT_RESERVED && !is_root)
1769: packet_disconnect("Requested forwarding of port %d but user is not root.",
1770: port);
1.73 markus 1771: /* Initiate forwarding */
1.56 markus 1772: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1773:
1774: /* Free the argument string. */
1775: xfree(hostname);
1.1 deraadt 1776: }
1777:
1.99 markus 1778: /*
1779: * Permits opening to any host/port if permitted_opens[] is empty. This is
1780: * usually called by the server, because the user could connect to any port
1781: * anyway, and the server has no way to know but to trust the client anyway.
1782: */
1783: void
1784: channel_permit_all_opens()
1785: {
1786: if (num_permitted_opens == 0)
1787: all_opens_permitted = 1;
1788: }
1789:
1.101 ! markus 1790: void
1.99 markus 1791: channel_add_permitted_opens(char *host, int port)
1792: {
1793: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1794: fatal("channel_request_remote_forwarding: too many forwards");
1795: debug("allow port forwarding to host %s port %d", host, port);
1796:
1797: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
1798: permitted_opens[num_permitted_opens].port_to_connect = port;
1799: num_permitted_opens++;
1800:
1801: all_opens_permitted = 0;
1802: }
1803:
1.101 ! markus 1804: void
1.99 markus 1805: channel_clear_permitted_opens(void)
1806: {
1807: int i;
1808:
1809: for (i = 0; i < num_permitted_opens; i++)
1810: xfree(permitted_opens[i].host_to_connect);
1811: num_permitted_opens = 0;
1812:
1813: }
1814:
1815:
1816: /* return socket to remote host, port */
1.41 markus 1817: int
1.99 markus 1818: connect_to(const char *host, u_short port)
1.41 markus 1819: {
1820: struct addrinfo hints, *ai, *aitop;
1821: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1822: int gaierr;
1823: int sock = -1;
1824:
1825: memset(&hints, 0, sizeof(hints));
1826: hints.ai_family = IPv4or6;
1827: hints.ai_socktype = SOCK_STREAM;
1.99 markus 1828: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 1829: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 1830: error("connect_to %.100s: unknown host (%s)", host,
1831: gai_strerror(gaierr));
1.41 markus 1832: return -1;
1833: }
1834: for (ai = aitop; ai; ai = ai->ai_next) {
1835: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1836: continue;
1837: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1838: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 1839: error("connect_to: getnameinfo failed");
1.41 markus 1840: continue;
1841: }
1842: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1843: if (sock < 0) {
1844: error("socket: %.100s", strerror(errno));
1845: continue;
1846: }
1.80 markus 1847: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1848: fatal("connect_to: F_SETFL: %s", strerror(errno));
1849: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1850: errno != EINPROGRESS) {
1.99 markus 1851: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 1852: strerror(errno));
1853: close(sock);
1.89 stevesk 1854: continue; /* fail -- try next */
1.41 markus 1855: }
1856: break; /* success */
1857:
1858: }
1859: freeaddrinfo(aitop);
1860: if (!ai) {
1.99 markus 1861: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 1862: return -1;
1863: }
1864: /* success */
1865: return sock;
1866: }
1.99 markus 1867:
1.73 markus 1868: int
1869: channel_connect_by_listen_adress(u_short listen_port)
1870: {
1871: int i;
1.99 markus 1872:
1.73 markus 1873: for (i = 0; i < num_permitted_opens; i++)
1874: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 1875: return connect_to(
1.73 markus 1876: permitted_opens[i].host_to_connect,
1877: permitted_opens[i].port_to_connect);
1.74 markus 1878: error("WARNING: Server requests forwarding for unknown listen_port %d",
1879: listen_port);
1.73 markus 1880: return -1;
1881: }
1882:
1.99 markus 1883: /* Check if connecting to that port is permitted and connect. */
1884: int
1885: channel_connect_to(const char *host, u_short port)
1886: {
1887: int i, permit;
1888:
1889: permit = all_opens_permitted;
1890: if (!permit) {
1891: for (i = 0; i < num_permitted_opens; i++)
1892: if (permitted_opens[i].port_to_connect == port &&
1893: strcmp(permitted_opens[i].host_to_connect, host) == 0)
1894: permit = 1;
1895:
1896: }
1897: if (!permit) {
1898: log("Received request to connect to host %.100s port %d, "
1899: "but the request was denied.", host, port);
1900: return -1;
1901: }
1902: return connect_to(host, port);
1903: }
1904:
1.27 markus 1905: /*
1906: * This is called after receiving PORT_OPEN message. This attempts to
1907: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
1908: * or CHANNEL_OPEN_FAILURE.
1909: */
1.1 deraadt 1910:
1.49 markus 1911: void
1.69 markus 1912: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1913: {
1.31 markus 1914: u_short host_port;
1.25 markus 1915: char *host, *originator_string;
1.99 markus 1916: int remote_channel, sock = -1, newch;
1.25 markus 1917:
1918: remote_channel = packet_get_int();
1.99 markus 1919: host = packet_get_string(NULL);
1.25 markus 1920: host_port = packet_get_int();
1921:
1.29 markus 1922: if (have_hostname_in_open) {
1.99 markus 1923: originator_string = packet_get_string(NULL);
1.29 markus 1924: } else {
1.25 markus 1925: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 1926: }
1.99 markus 1927: packet_done();
1928: sock = channel_connect_to(host, host_port);
1929: if (sock != -1) {
1.75 markus 1930: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
1931: sock, originator_string);
1.41 markus 1932: channels[newch].remote_id = remote_channel;
1933:
1.99 markus 1934: /*XXX delay answer? */
1.41 markus 1935: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1936: packet_put_int(remote_channel);
1937: packet_put_int(newch);
1938: packet_send();
1939: } else {
1940: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1941: packet_put_int(remote_channel);
1942: packet_send();
1.25 markus 1943: }
1944: xfree(host);
1.1 deraadt 1945: }
1946:
1.27 markus 1947: /*
1948: * Creates an internet domain socket for listening for X11 connections.
1949: * Returns a suitable value for the DISPLAY variable, or NULL if an error
1950: * occurs.
1951: */
1.1 deraadt 1952:
1.35 markus 1953: #define NUM_SOCKS 10
1954:
1.25 markus 1955: char *
1.33 markus 1956: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 1957: {
1.31 markus 1958: int display_number, sock;
1959: u_short port;
1.35 markus 1960: struct addrinfo hints, *ai, *aitop;
1961: char strport[NI_MAXSERV];
1962: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1963: char display[512];
1.25 markus 1964: char hostname[MAXHOSTNAMELEN];
1965:
1.33 markus 1966: for (display_number = x11_display_offset;
1.25 markus 1967: display_number < MAX_DISPLAYS;
1968: display_number++) {
1969: port = 6000 + display_number;
1.35 markus 1970: memset(&hints, 0, sizeof(hints));
1971: hints.ai_family = IPv4or6;
1.36 markus 1972: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 1973: hints.ai_socktype = SOCK_STREAM;
1974: snprintf(strport, sizeof strport, "%d", port);
1975: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1976: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 1977: return NULL;
1978: }
1.35 markus 1979: for (ai = aitop; ai; ai = ai->ai_next) {
1980: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1981: continue;
1982: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1983: if (sock < 0) {
1984: error("socket: %.100s", strerror(errno));
1985: return NULL;
1986: }
1987: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1988: debug("bind port %d: %.100s", port, strerror(errno));
1989: shutdown(sock, SHUT_RDWR);
1990: close(sock);
1991: for (n = 0; n < num_socks; n++) {
1992: shutdown(socks[n], SHUT_RDWR);
1993: close(socks[n]);
1994: }
1995: num_socks = 0;
1996: break;
1997: }
1998: socks[num_socks++] = sock;
1999: if (num_socks == NUM_SOCKS)
2000: break;
1.25 markus 2001: }
1.83 stevesk 2002: freeaddrinfo(aitop);
1.35 markus 2003: if (num_socks > 0)
2004: break;
1.25 markus 2005: }
2006: if (display_number >= MAX_DISPLAYS) {
2007: error("Failed to allocate internet-domain X11 display socket.");
2008: return NULL;
2009: }
2010: /* Start listening for connections on the socket. */
1.35 markus 2011: for (n = 0; n < num_socks; n++) {
2012: sock = socks[n];
2013: if (listen(sock, 5) < 0) {
2014: error("listen: %.100s", strerror(errno));
2015: shutdown(sock, SHUT_RDWR);
2016: close(sock);
2017: return NULL;
2018: }
1.25 markus 2019: }
1.35 markus 2020:
1.25 markus 2021: /* Set up a suitable value for the DISPLAY variable. */
2022: if (gethostname(hostname, sizeof(hostname)) < 0)
2023: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2024: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2025: display_number, screen_number);
2026:
1.35 markus 2027: /* Allocate a channel for each socket. */
2028: for (n = 0; n < num_socks; n++) {
2029: sock = socks[n];
1.51 markus 2030: (void) channel_new("x11 listener",
2031: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2032: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2033: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2034: }
1.1 deraadt 2035:
1.25 markus 2036: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2037: return xstrdup(display);
1.1 deraadt 2038: }
2039:
2040: #ifndef X_UNIX_PATH
2041: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2042: #endif
2043:
2044: static
2045: int
1.77 markus 2046: connect_local_xsocket(u_int dnr)
1.1 deraadt 2047: {
1.25 markus 2048: static const char *const x_sockets[] = {
2049: X_UNIX_PATH "%u",
2050: "/var/X/.X11-unix/X" "%u",
2051: "/usr/spool/sockets/X11/" "%u",
2052: NULL
2053: };
2054: int sock;
2055: struct sockaddr_un addr;
2056: const char *const * path;
2057:
2058: for (path = x_sockets; *path; ++path) {
2059: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2060: if (sock < 0)
2061: error("socket: %.100s", strerror(errno));
2062: memset(&addr, 0, sizeof(addr));
2063: addr.sun_family = AF_UNIX;
2064: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2065: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2066: return sock;
2067: close(sock);
2068: }
2069: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2070: return -1;
1.1 deraadt 2071: }
2072:
1.51 markus 2073: int
2074: x11_connect_display(void)
1.1 deraadt 2075: {
1.51 markus 2076: int display_number, sock = 0;
1.25 markus 2077: const char *display;
1.51 markus 2078: char buf[1024], *cp;
1.35 markus 2079: struct addrinfo hints, *ai, *aitop;
2080: char strport[NI_MAXSERV];
2081: int gaierr;
1.25 markus 2082:
2083: /* Try to open a socket for the local X server. */
2084: display = getenv("DISPLAY");
2085: if (!display) {
2086: error("DISPLAY not set.");
1.51 markus 2087: return -1;
1.25 markus 2088: }
1.27 markus 2089: /*
2090: * Now we decode the value of the DISPLAY variable and make a
2091: * connection to the real X server.
2092: */
2093:
2094: /*
2095: * Check if it is a unix domain socket. Unix domain displays are in
2096: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2097: */
1.25 markus 2098: if (strncmp(display, "unix:", 5) == 0 ||
2099: display[0] == ':') {
2100: /* Connect to the unix domain socket. */
2101: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2102: error("Could not parse display number from DISPLAY: %.100s",
2103: display);
1.51 markus 2104: return -1;
1.25 markus 2105: }
2106: /* Create a socket. */
2107: sock = connect_local_xsocket(display_number);
2108: if (sock < 0)
1.51 markus 2109: return -1;
1.25 markus 2110:
2111: /* OK, we now have a connection to the display. */
1.51 markus 2112: return sock;
1.25 markus 2113: }
1.27 markus 2114: /*
2115: * Connect to an inet socket. The DISPLAY value is supposedly
2116: * hostname:d[.s], where hostname may also be numeric IP address.
2117: */
1.25 markus 2118: strncpy(buf, display, sizeof(buf));
2119: buf[sizeof(buf) - 1] = 0;
2120: cp = strchr(buf, ':');
2121: if (!cp) {
2122: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2123: return -1;
1.25 markus 2124: }
2125: *cp = 0;
1.27 markus 2126: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2127: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2128: error("Could not parse display number from DISPLAY: %.100s",
2129: display);
1.51 markus 2130: return -1;
1.25 markus 2131: }
1.35 markus 2132:
2133: /* Look up the host address */
2134: memset(&hints, 0, sizeof(hints));
2135: hints.ai_family = IPv4or6;
2136: hints.ai_socktype = SOCK_STREAM;
2137: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2138: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2139: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2140: return -1;
1.25 markus 2141: }
1.35 markus 2142: for (ai = aitop; ai; ai = ai->ai_next) {
2143: /* Create a socket. */
2144: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2145: if (sock < 0) {
2146: debug("socket: %.100s", strerror(errno));
1.41 markus 2147: continue;
2148: }
2149: /* Connect it to the display. */
2150: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2151: debug("connect %.100s port %d: %.100s", buf,
2152: 6000 + display_number, strerror(errno));
2153: close(sock);
2154: continue;
2155: }
2156: /* Success */
2157: break;
1.35 markus 2158: }
2159: freeaddrinfo(aitop);
2160: if (!ai) {
1.49 markus 2161: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2162: strerror(errno));
1.51 markus 2163: return -1;
1.25 markus 2164: }
1.51 markus 2165: return sock;
2166: }
2167:
2168: /*
2169: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2170: * the remote channel number. We should do whatever we want, and respond
2171: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2172: */
2173:
2174: void
1.69 markus 2175: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2176: {
2177: int remote_channel, sock = 0, newch;
2178: char *remote_host;
1.77 markus 2179: u_int remote_len;
1.25 markus 2180:
1.51 markus 2181: /* Get remote channel number. */
2182: remote_channel = packet_get_int();
2183:
2184: /* Get remote originator name. */
2185: if (have_hostname_in_open) {
2186: remote_host = packet_get_string(&remote_len);
2187: remote_len += 4;
2188: } else {
2189: remote_host = xstrdup("unknown (remote did not supply name)");
2190: remote_len = 0;
2191: }
1.25 markus 2192:
1.51 markus 2193: debug("Received X11 open request.");
2194: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2195:
1.51 markus 2196: /* Obtain a connection to the real X display. */
2197: sock = x11_connect_display();
2198: if (sock == -1) {
2199: /* Send refusal to the remote host. */
2200: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2201: packet_put_int(remote_channel);
2202: packet_send();
2203: } else {
2204: /* Allocate a channel for this connection. */
2205: newch = channel_allocate(
2206: (x11_saved_proto == NULL) ?
2207: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2208: sock, remote_host);
2209: channels[newch].remote_id = remote_channel;
1.25 markus 2210:
1.51 markus 2211: /* Send a confirmation to the remote host. */
2212: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2213: packet_put_int(remote_channel);
2214: packet_put_int(newch);
2215: packet_send();
2216: }
1.72 markus 2217: }
2218:
2219: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2220: void
2221: deny_input_open(int type, int plen, void *ctxt)
2222: {
2223: int rchan = packet_get_int();
2224: switch(type){
2225: case SSH_SMSG_AGENT_OPEN:
2226: error("Warning: ssh server tried agent forwarding.");
2227: break;
2228: case SSH_SMSG_X11_OPEN:
2229: error("Warning: ssh server tried X11 forwarding.");
2230: break;
2231: default:
2232: error("deny_input_open: type %d plen %d", type, plen);
2233: break;
2234: }
2235: error("Warning: this is probably a break in attempt by a malicious server.");
2236: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2237: packet_put_int(rchan);
2238: packet_send();
1.1 deraadt 2239: }
2240:
1.27 markus 2241: /*
2242: * Requests forwarding of X11 connections, generates fake authentication
2243: * data, and enables authentication spoofing.
2244: */
1.1 deraadt 2245:
1.49 markus 2246: void
1.51 markus 2247: x11_request_forwarding_with_spoofing(int client_session_id,
2248: const char *proto, const char *data)
1.1 deraadt 2249: {
1.77 markus 2250: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2251: u_int i, value, len;
1.25 markus 2252: char *new_data;
2253: int screen_number;
2254: const char *cp;
2255: u_int32_t rand = 0;
2256:
2257: cp = getenv("DISPLAY");
2258: if (cp)
2259: cp = strchr(cp, ':');
2260: if (cp)
2261: cp = strchr(cp, '.');
2262: if (cp)
2263: screen_number = atoi(cp + 1);
2264: else
2265: screen_number = 0;
2266:
2267: /* Save protocol name. */
2268: x11_saved_proto = xstrdup(proto);
2269:
1.27 markus 2270: /*
2271: * Extract real authentication data and generate fake data of the
2272: * same length.
2273: */
1.25 markus 2274: x11_saved_data = xmalloc(data_len);
2275: x11_fake_data = xmalloc(data_len);
2276: for (i = 0; i < data_len; i++) {
2277: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2278: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2279: if (i % 4 == 0)
2280: rand = arc4random();
2281: x11_saved_data[i] = value;
2282: x11_fake_data[i] = rand & 0xff;
2283: rand >>= 8;
2284: }
2285: x11_saved_data_len = data_len;
2286: x11_fake_data_len = data_len;
2287:
2288: /* Convert the fake data into hex. */
1.90 markus 2289: len = 2 * data_len + 1;
2290: new_data = xmalloc(len);
1.25 markus 2291: for (i = 0; i < data_len; i++)
1.90 markus 2292: snprintf(new_data + 2 * i, len - 2 * i,
2293: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2294:
2295: /* Send the request packet. */
1.51 markus 2296: if (compat20) {
2297: channel_request_start(client_session_id, "x11-req", 0);
2298: packet_put_char(0); /* XXX bool single connection */
2299: } else {
2300: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2301: }
2302: packet_put_cstring(proto);
2303: packet_put_cstring(new_data);
1.25 markus 2304: packet_put_int(screen_number);
2305: packet_send();
2306: packet_write_wait();
2307: xfree(new_data);
1.1 deraadt 2308: }
2309:
2310: /* Sends a message to the server to request authentication fd forwarding. */
2311:
1.49 markus 2312: void
1.25 markus 2313: auth_request_forwarding()
1.1 deraadt 2314: {
1.25 markus 2315: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2316: packet_send();
2317: packet_write_wait();
1.1 deraadt 2318: }
2319:
1.27 markus 2320: /*
2321: * Returns the name of the forwarded authentication socket. Returns NULL if
2322: * there is no forwarded authentication socket. The returned value points to
2323: * a static buffer.
2324: */
1.1 deraadt 2325:
1.25 markus 2326: char *
2327: auth_get_socket_name()
1.1 deraadt 2328: {
1.25 markus 2329: return channel_forwarded_auth_socket_name;
1.1 deraadt 2330: }
2331:
1.12 markus 2332: /* removes the agent forwarding socket */
2333:
1.49 markus 2334: void
1.25 markus 2335: cleanup_socket(void)
2336: {
1.78 markus 2337: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2338: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2339: }
2340:
1.27 markus 2341: /*
1.59 markus 2342: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2343: * This starts forwarding authentication requests.
2344: */
1.1 deraadt 2345:
1.59 markus 2346: int
1.25 markus 2347: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2348: {
1.25 markus 2349: int sock, newch;
2350: struct sockaddr_un sunaddr;
2351:
2352: if (auth_get_socket_name() != NULL)
2353: fatal("Protocol error: authentication forwarding requested twice.");
2354:
2355: /* Temporarily drop privileged uid for mkdir/bind. */
2356: temporarily_use_uid(pw->pw_uid);
2357:
2358: /* Allocate a buffer for the socket name, and format the name. */
2359: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2360: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2361: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2362:
2363: /* Create private directory for socket */
1.59 markus 2364: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2365: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2366: strerror(errno));
2367: restore_uid();
2368: xfree(channel_forwarded_auth_socket_name);
2369: xfree(channel_forwarded_auth_socket_dir);
2370: channel_forwarded_auth_socket_name = NULL;
2371: channel_forwarded_auth_socket_dir = NULL;
2372: return 0;
2373: }
1.25 markus 2374: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2375: channel_forwarded_auth_socket_dir, (int) getpid());
2376:
2377: if (atexit(cleanup_socket) < 0) {
2378: int saved = errno;
2379: cleanup_socket();
2380: packet_disconnect("socket: %.100s", strerror(saved));
2381: }
2382: /* Create the socket. */
2383: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2384: if (sock < 0)
2385: packet_disconnect("socket: %.100s", strerror(errno));
2386:
2387: /* Bind it to the name. */
2388: memset(&sunaddr, 0, sizeof(sunaddr));
2389: sunaddr.sun_family = AF_UNIX;
2390: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2391: sizeof(sunaddr.sun_path));
2392:
2393: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2394: packet_disconnect("bind: %.100s", strerror(errno));
2395:
2396: /* Restore the privileged uid. */
2397: restore_uid();
2398:
2399: /* Start listening on the socket. */
2400: if (listen(sock, 5) < 0)
2401: packet_disconnect("listen: %.100s", strerror(errno));
2402:
2403: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2404: newch = channel_new("auth socket",
2405: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2406: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2407: 0, xstrdup("auth socket"), 1);
2408:
1.32 deraadt 2409: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2410: sizeof(channels[newch].path));
1.59 markus 2411: return 1;
1.1 deraadt 2412: }
2413:
2414: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2415:
1.49 markus 2416: void
1.69 markus 2417: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2418: {
1.25 markus 2419: int remch, sock, newch;
2420: char *dummyname;
1.41 markus 2421:
2422: packet_integrity_check(plen, 4, type);
1.25 markus 2423:
2424: /* Read the remote channel number from the message. */
2425: remch = packet_get_int();
2426:
1.27 markus 2427: /*
2428: * Get a connection to the local authentication agent (this may again
2429: * get forwarded).
2430: */
1.25 markus 2431: sock = ssh_get_authentication_socket();
2432:
1.27 markus 2433: /*
2434: * If we could not connect the agent, send an error message back to
2435: * the server. This should never happen unless the agent dies,
2436: * because authentication forwarding is only enabled if we have an
2437: * agent.
2438: */
1.25 markus 2439: if (sock < 0) {
2440: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2441: packet_put_int(remch);
2442: packet_send();
2443: return;
2444: }
2445: debug("Forwarding authentication connection.");
1.1 deraadt 2446:
1.27 markus 2447: /*
2448: * Dummy host name. This will be freed when the channel is freed; it
2449: * will still be valid in the packet_put_string below since the
2450: * channel cannot yet be freed at that point.
2451: */
1.25 markus 2452: dummyname = xstrdup("authentication agent connection");
2453:
2454: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2455: channels[newch].remote_id = remch;
2456:
2457: /* Send a confirmation to the remote host. */
2458: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2459: packet_put_int(remch);
2460: packet_put_int(newch);
1.44 markus 2461: packet_send();
2462: }
2463:
2464: void
1.51 markus 2465: channel_start_open(int id)
1.44 markus 2466: {
2467: Channel *c = channel_lookup(id);
2468: if (c == NULL) {
2469: log("channel_open: %d: bad id", id);
2470: return;
2471: }
1.51 markus 2472: debug("send channel open %d", id);
1.44 markus 2473: packet_start(SSH2_MSG_CHANNEL_OPEN);
2474: packet_put_cstring(c->ctype);
2475: packet_put_int(c->self);
2476: packet_put_int(c->local_window);
2477: packet_put_int(c->local_maxpacket);
1.51 markus 2478: }
2479: void
2480: channel_open(int id)
2481: {
2482: /* XXX REMOVE ME */
2483: channel_start_open(id);
1.44 markus 2484: packet_send();
2485: }
2486: void
2487: channel_request(int id, char *service, int wantconfirm)
2488: {
2489: channel_request_start(id, service, wantconfirm);
2490: packet_send();
2491: debug("channel request %d: %s", id, service) ;
2492: }
2493: void
2494: channel_request_start(int id, char *service, int wantconfirm)
2495: {
2496: Channel *c = channel_lookup(id);
2497: if (c == NULL) {
2498: log("channel_request: %d: bad id", id);
2499: return;
2500: }
2501: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2502: packet_put_int(c->remote_id);
2503: packet_put_cstring(service);
2504: packet_put_char(wantconfirm);
2505: }
2506: void
2507: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2508: {
2509: Channel *c = channel_lookup(id);
2510: if (c == NULL) {
2511: log("channel_register_callback: %d: bad id", id);
2512: return;
2513: }
2514: c->cb_event = mtype;
2515: c->cb_fn = fn;
2516: c->cb_arg = arg;
2517: }
2518: void
2519: channel_register_cleanup(int id, channel_callback_fn *fn)
2520: {
2521: Channel *c = channel_lookup(id);
2522: if (c == NULL) {
2523: log("channel_register_cleanup: %d: bad id", id);
2524: return;
2525: }
2526: c->dettach_user = fn;
2527: }
2528: void
2529: channel_cancel_cleanup(int id)
2530: {
2531: Channel *c = channel_lookup(id);
2532: if (c == NULL) {
2533: log("channel_cancel_cleanup: %d: bad id", id);
2534: return;
2535: }
2536: c->dettach_user = NULL;
1.65 markus 2537: }
1.89 stevesk 2538: void
1.65 markus 2539: channel_register_filter(int id, channel_filter_fn *fn)
2540: {
2541: Channel *c = channel_lookup(id);
2542: if (c == NULL) {
2543: log("channel_register_filter: %d: bad id", id);
2544: return;
2545: }
2546: c->input_filter = fn;
1.44 markus 2547: }
2548:
2549: void
1.71 markus 2550: channel_set_fds(int id, int rfd, int wfd, int efd,
2551: int extusage, int nonblock)
1.44 markus 2552: {
2553: Channel *c = channel_lookup(id);
2554: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2555: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2556: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2557: c->type = SSH_CHANNEL_OPEN;
2558: /* XXX window size? */
1.68 markus 2559: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2560: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2561: packet_put_int(c->remote_id);
2562: packet_put_int(c->local_window);
1.25 markus 2563: packet_send();
1.1 deraadt 2564: }
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