Annotation of src/usr.bin/ssh/channels.c, Revision 1.88
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"
1.88 ! markus 43: RCSID("$OpenBSD: channels.c,v 1.87 2001/01/31 20:37:22 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:
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: */
512: log("X11 connection rejected because of wrong authentication.\r\n");
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;
707: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
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: {
759: int len;
1.25 markus 760:
1.41 markus 761: /* Send buffered output data to the socket. */
762: if (c->wfd != -1 &&
763: FD_ISSET(c->wfd, writeset) &&
764: buffer_len(&c->output) > 0) {
765: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 766: buffer_len(&c->output));
767: if (len < 0 && (errno == EINTR || errno == EAGAIN))
768: return 1;
1.41 markus 769: if (len <= 0) {
770: if (compat13) {
771: buffer_consume(&c->output, buffer_len(&c->output));
772: debug("Channel %d status set to input draining.", c->self);
773: c->type = SSH_CHANNEL_INPUT_DRAINING;
774: } else {
775: chan_write_failed(c);
776: }
777: return -1;
1.25 markus 778: }
1.41 markus 779: buffer_consume(&c->output, len);
1.44 markus 780: if (compat20 && len > 0) {
781: c->local_consumed += len;
782: }
783: }
784: return 1;
785: }
786: int
787: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
788: {
789: char buf[16*1024];
790: int len;
791:
1.45 markus 792: /** XXX handle drain efd, too */
1.44 markus 793: if (c->efd != -1) {
794: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
795: FD_ISSET(c->efd, writeset) &&
796: buffer_len(&c->extended) > 0) {
797: len = write(c->efd, buffer_ptr(&c->extended),
798: buffer_len(&c->extended));
1.70 markus 799: debug2("channel %d: written %d to efd %d",
1.44 markus 800: c->self, len, c->efd);
801: if (len > 0) {
802: buffer_consume(&c->extended, len);
803: c->local_consumed += len;
804: }
805: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
806: FD_ISSET(c->efd, readset)) {
807: len = read(c->efd, buf, sizeof(buf));
1.70 markus 808: debug2("channel %d: read %d from efd %d",
1.44 markus 809: c->self, len, c->efd);
1.45 markus 810: if (len == 0) {
811: debug("channel %d: closing efd %d",
812: c->self, c->efd);
813: close(c->efd);
814: c->efd = -1;
815: } else if (len > 0)
1.44 markus 816: buffer_append(&c->extended, buf, len);
817: }
818: }
819: return 1;
820: }
821: int
822: channel_check_window(Channel *c, fd_set * readset, fd_set * writeset)
823: {
1.46 markus 824: if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 825: c->local_window < c->local_window_max/2 &&
826: c->local_consumed > 0) {
827: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
828: packet_put_int(c->remote_id);
829: packet_put_int(c->local_consumed);
830: packet_send();
1.70 markus 831: debug2("channel %d: window %d sent adjust %d",
1.44 markus 832: c->self, c->local_window,
833: c->local_consumed);
834: c->local_window += c->local_consumed;
835: c->local_consumed = 0;
1.1 deraadt 836: }
1.41 markus 837: return 1;
1.1 deraadt 838: }
839:
1.41 markus 840: void
841: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
842: {
843: channel_handle_rfd(c, readset, writeset);
844: channel_handle_wfd(c, readset, writeset);
845: }
1.1 deraadt 846:
1.41 markus 847: void
1.44 markus 848: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
849: {
850: channel_handle_rfd(c, readset, writeset);
851: channel_handle_wfd(c, readset, writeset);
852: channel_handle_efd(c, readset, writeset);
853: channel_check_window(c, readset, writeset);
854: }
855:
856: void
1.41 markus 857: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 858: {
1.41 markus 859: int len;
860: /* Send buffered output data to the socket. */
861: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
862: len = write(c->sock, buffer_ptr(&c->output),
863: buffer_len(&c->output));
864: if (len <= 0)
865: buffer_consume(&c->output, buffer_len(&c->output));
866: else
867: buffer_consume(&c->output, len);
868: }
869: }
1.25 markus 870:
1.41 markus 871: void
1.44 markus 872: channel_handler_init_20(void)
873: {
874: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 875: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 876: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 877: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 878: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 879: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 880: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.44 markus 881:
882: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
883: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 884: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 885: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 886: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 887: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.44 markus 888: }
889:
890: void
1.41 markus 891: channel_handler_init_13(void)
892: {
893: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
894: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
895: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
896: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
897: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
898: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
899: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 900: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 901:
1.41 markus 902: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
903: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
904: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
905: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
906: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 907: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 908: }
1.25 markus 909:
1.41 markus 910: void
911: channel_handler_init_15(void)
912: {
913: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 914: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 915: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
916: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
917: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 918: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.25 markus 919:
1.41 markus 920: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
921: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
922: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
923: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 924: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.41 markus 925: }
1.27 markus 926:
1.41 markus 927: void
928: channel_handler_init(void)
929: {
930: int i;
931: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
932: channel_pre[i] = NULL;
933: channel_post[i] = NULL;
934: }
1.44 markus 935: if (compat20)
936: channel_handler_init_20();
937: else if (compat13)
1.41 markus 938: channel_handler_init_13();
939: else
940: channel_handler_init_15();
941: }
1.25 markus 942:
1.49 markus 943: void
1.41 markus 944: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
945: {
946: static int did_init = 0;
947: int i;
948: Channel *c;
1.25 markus 949:
1.41 markus 950: if (!did_init) {
951: channel_handler_init();
952: did_init = 1;
953: }
954: for (i = 0; i < channels_alloc; i++) {
955: c = &channels[i];
956: if (c->type == SSH_CHANNEL_FREE)
957: continue;
958: if (ftab[c->type] == NULL)
1.25 markus 959: continue;
1.41 markus 960: (*ftab[c->type])(c, readset, writeset);
1.44 markus 961: chan_delete_if_full_closed(c);
1.1 deraadt 962: }
963: }
964:
1.49 markus 965: void
1.84 markus 966: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp)
1.41 markus 967: {
1.84 markus 968: int n;
969: u_int sz;
970:
971: n = MAX(*maxfdp, channel_max_fd);
972:
973: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
974: if (*readsetp == NULL || n > *maxfdp) {
975: if (*readsetp)
976: xfree(*readsetp);
977: if (*writesetp)
978: xfree(*writesetp);
979: *readsetp = xmalloc(sz);
980: *writesetp = xmalloc(sz);
981: *maxfdp = n;
982: }
983: memset(*readsetp, 0, sz);
984: memset(*writesetp, 0, sz);
985:
986: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 987: }
988:
1.49 markus 989: void
1.41 markus 990: channel_after_select(fd_set * readset, fd_set * writeset)
991: {
992: channel_handler(channel_post, readset, writeset);
993: }
994:
1.84 markus 995: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 996:
1.49 markus 997: void
1.25 markus 998: channel_output_poll()
1.1 deraadt 999: {
1.25 markus 1000: int len, i;
1.41 markus 1001: Channel *c;
1.1 deraadt 1002:
1.25 markus 1003: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1004: c = &channels[i];
1.37 markus 1005:
1.27 markus 1006: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1007: if (compat13) {
1.41 markus 1008: if (c->type != SSH_CHANNEL_OPEN &&
1009: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1010: continue;
1011: } else {
1.41 markus 1012: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1013: continue;
1.41 markus 1014: if (c->istate != CHAN_INPUT_OPEN &&
1015: c->istate != CHAN_INPUT_WAIT_DRAIN)
1.37 markus 1016: continue;
1017: }
1.46 markus 1018: if (compat20 &&
1019: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.44 markus 1020: debug("channel: %d: no data after CLOSE", c->self);
1021: continue;
1022: }
1.25 markus 1023:
1024: /* Get the amount of buffered data for this channel. */
1.41 markus 1025: len = buffer_len(&c->input);
1.25 markus 1026: if (len > 0) {
1.27 markus 1027: /* Send some data for the other side over the secure connection. */
1.44 markus 1028: if (compat20) {
1029: if (len > c->remote_window)
1030: len = c->remote_window;
1031: if (len > c->remote_maxpacket)
1032: len = c->remote_maxpacket;
1.25 markus 1033: } else {
1.44 markus 1034: if (packet_is_interactive()) {
1035: if (len > 1024)
1036: len = 512;
1037: } else {
1038: /* Keep the packets at reasonable size. */
1039: if (len > packet_get_maxsize()/2)
1040: len = packet_get_maxsize()/2;
1041: }
1.25 markus 1042: }
1.41 markus 1043: if (len > 0) {
1.44 markus 1044: packet_start(compat20 ?
1045: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1046: packet_put_int(c->remote_id);
1047: packet_put_string(buffer_ptr(&c->input), len);
1048: packet_send();
1049: buffer_consume(&c->input, len);
1050: c->remote_window -= len;
1051: }
1052: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1053: if (compat13)
1054: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1055: /*
1056: * input-buffer is empty and read-socket shutdown:
1057: * tell peer, that we will not send more data: send IEOF
1058: */
1.41 markus 1059: chan_ibuf_empty(c);
1.25 markus 1060: }
1.44 markus 1061: /* Send extended data, i.e. stderr */
1062: if (compat20 &&
1063: c->remote_window > 0 &&
1064: (len = buffer_len(&c->extended)) > 0 &&
1065: c->extended_usage == CHAN_EXTENDED_READ) {
1066: if (len > c->remote_window)
1067: len = c->remote_window;
1068: if (len > c->remote_maxpacket)
1069: len = c->remote_maxpacket;
1070: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1071: packet_put_int(c->remote_id);
1072: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1073: packet_put_string(buffer_ptr(&c->extended), len);
1074: packet_send();
1075: buffer_consume(&c->extended, len);
1076: c->remote_window -= len;
1077: }
1.25 markus 1078: }
1.1 deraadt 1079: }
1080:
1.27 markus 1081: /*
1082: * This is called when a packet of type CHANNEL_DATA has just been received.
1083: * The message type has already been consumed, but channel number and data is
1084: * still there.
1085: */
1.1 deraadt 1086:
1.49 markus 1087: void
1.69 markus 1088: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1089: {
1.37 markus 1090: int id;
1.25 markus 1091: char *data;
1.77 markus 1092: u_int data_len;
1.41 markus 1093: Channel *c;
1.25 markus 1094:
1095: /* Get the channel number and verify it. */
1.37 markus 1096: id = packet_get_int();
1.41 markus 1097: c = channel_lookup(id);
1098: if (c == NULL)
1.37 markus 1099: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1100:
1101: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1102: if (c->type != SSH_CHANNEL_OPEN &&
1103: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1104: return;
1105:
1106: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1107: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1108: return;
1109:
1110: /* Get the data. */
1111: data = packet_get_string(&data_len);
1.48 markus 1112: packet_done();
1.41 markus 1113:
1.44 markus 1114: if (compat20){
1115: if (data_len > c->local_maxpacket) {
1116: log("channel %d: rcvd big packet %d, maxpack %d",
1117: c->self, data_len, c->local_maxpacket);
1118: }
1119: if (data_len > c->local_window) {
1120: log("channel %d: rcvd too much data %d, win %d",
1121: c->self, data_len, c->local_window);
1122: xfree(data);
1123: return;
1124: }
1125: c->local_window -= data_len;
1126: }else{
1127: packet_integrity_check(plen, 4 + 4 + data_len, type);
1128: }
1.41 markus 1129: buffer_append(&c->output, data, data_len);
1.25 markus 1130: xfree(data);
1.1 deraadt 1131: }
1.49 markus 1132: void
1.69 markus 1133: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1134: {
1135: int id;
1136: int tcode;
1137: char *data;
1.77 markus 1138: u_int data_len;
1.44 markus 1139: Channel *c;
1140:
1141: /* Get the channel number and verify it. */
1142: id = packet_get_int();
1143: c = channel_lookup(id);
1144:
1145: if (c == NULL)
1146: packet_disconnect("Received extended_data for bad channel %d.", id);
1147: if (c->type != SSH_CHANNEL_OPEN) {
1148: log("channel %d: ext data for non open", id);
1149: return;
1150: }
1151: tcode = packet_get_int();
1152: if (c->efd == -1 ||
1153: c->extended_usage != CHAN_EXTENDED_WRITE ||
1154: tcode != SSH2_EXTENDED_DATA_STDERR) {
1155: log("channel %d: bad ext data", c->self);
1156: return;
1157: }
1158: data = packet_get_string(&data_len);
1.48 markus 1159: packet_done();
1.44 markus 1160: if (data_len > c->local_window) {
1161: log("channel %d: rcvd too much extended_data %d, win %d",
1162: c->self, data_len, c->local_window);
1163: xfree(data);
1164: return;
1165: }
1.70 markus 1166: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1167: c->local_window -= data_len;
1168: buffer_append(&c->extended, data, data_len);
1169: xfree(data);
1170: }
1171:
1.1 deraadt 1172:
1.27 markus 1173: /*
1174: * Returns true if no channel has too much buffered data, and false if one or
1175: * more channel is overfull.
1176: */
1.1 deraadt 1177:
1.49 markus 1178: int
1.25 markus 1179: channel_not_very_much_buffered_data()
1.1 deraadt 1180: {
1.77 markus 1181: u_int i;
1.41 markus 1182: Channel *c;
1.25 markus 1183:
1184: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1185: c = &channels[i];
1186: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1187: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1188: debug("channel %d: big input buffer %d",
1189: c->self, buffer_len(&c->input));
1.25 markus 1190: return 0;
1.41 markus 1191: }
1192: if (buffer_len(&c->output) > packet_get_maxsize()) {
1193: debug("channel %d: big output buffer %d",
1194: c->self, buffer_len(&c->output));
1.25 markus 1195: return 0;
1.41 markus 1196: }
1.25 markus 1197: }
1.1 deraadt 1198: }
1.25 markus 1199: return 1;
1.1 deraadt 1200: }
1201:
1.49 markus 1202: void
1.69 markus 1203: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1204: {
1205: int id;
1206: Channel *c;
1207:
1208: packet_integrity_check(plen, 4, type);
1209:
1210: id = packet_get_int();
1211: c = channel_lookup(id);
1212: if (c == NULL)
1213: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1214: chan_rcvd_ieof(c);
1215: }
1.1 deraadt 1216:
1.49 markus 1217: void
1.69 markus 1218: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1219: {
1.41 markus 1220: int id;
1221: Channel *c;
1.1 deraadt 1222:
1.41 markus 1223: packet_integrity_check(plen, 4, type);
1224:
1225: id = packet_get_int();
1226: c = channel_lookup(id);
1227: if (c == NULL)
1228: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1229:
1230: /*
1231: * Send a confirmation that we have closed the channel and no more
1232: * data is coming for it.
1233: */
1.25 markus 1234: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1235: packet_put_int(c->remote_id);
1.25 markus 1236: packet_send();
1237:
1.27 markus 1238: /*
1239: * If the channel is in closed state, we have sent a close request,
1240: * and the other side will eventually respond with a confirmation.
1241: * Thus, we cannot free the channel here, because then there would be
1242: * no-one to receive the confirmation. The channel gets freed when
1243: * the confirmation arrives.
1244: */
1.41 markus 1245: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1246: /*
1247: * Not a closed channel - mark it as draining, which will
1248: * cause it to be freed later.
1249: */
1.41 markus 1250: buffer_consume(&c->input, buffer_len(&c->input));
1251: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1252: }
1.1 deraadt 1253: }
1254:
1.41 markus 1255: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1256: void
1.69 markus 1257: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1258: {
1259: int id = packet_get_int();
1260: Channel *c = channel_lookup(id);
1261: packet_integrity_check(plen, 4, type);
1262: if (c == NULL)
1263: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1264: chan_rcvd_oclose(c);
1265: }
1.1 deraadt 1266:
1.49 markus 1267: void
1.69 markus 1268: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1269: {
1.41 markus 1270: int id = packet_get_int();
1271: Channel *c = channel_lookup(id);
1.1 deraadt 1272:
1.48 markus 1273: packet_done();
1.41 markus 1274: if (c == NULL)
1275: packet_disconnect("Received close confirmation for "
1276: "out-of-range channel %d.", id);
1277: if (c->type != SSH_CHANNEL_CLOSED)
1278: packet_disconnect("Received close confirmation for "
1279: "non-closed channel %d (type %d).", id, c->type);
1280: channel_free(c->self);
1.1 deraadt 1281: }
1282:
1.49 markus 1283: void
1.69 markus 1284: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1285: {
1.41 markus 1286: int id, remote_id;
1287: Channel *c;
1.1 deraadt 1288:
1.44 markus 1289: if (!compat20)
1290: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1291:
1.41 markus 1292: id = packet_get_int();
1293: c = channel_lookup(id);
1.25 markus 1294:
1.41 markus 1295: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1296: packet_disconnect("Received open confirmation for "
1297: "non-opening channel %d.", id);
1298: remote_id = packet_get_int();
1.27 markus 1299: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1300: c->remote_id = remote_id;
1301: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1302:
1303: if (compat20) {
1304: c->remote_window = packet_get_int();
1305: c->remote_maxpacket = packet_get_int();
1.48 markus 1306: packet_done();
1.44 markus 1307: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1308: debug2("callback start");
1.44 markus 1309: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1310: debug2("callback done");
1.44 markus 1311: }
1312: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1313: c->remote_window, c->remote_maxpacket);
1314: }
1.1 deraadt 1315: }
1316:
1.49 markus 1317: void
1.69 markus 1318: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1319: {
1.86 markus 1320: int id, reason;
1321: char *msg = NULL, *lang = NULL;
1.41 markus 1322: Channel *c;
1323:
1.44 markus 1324: if (!compat20)
1325: packet_integrity_check(plen, 4, type);
1.41 markus 1326:
1327: id = packet_get_int();
1328: c = channel_lookup(id);
1.25 markus 1329:
1.41 markus 1330: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1331: packet_disconnect("Received open failure for "
1332: "non-opening channel %d.", id);
1.44 markus 1333: if (compat20) {
1.86 markus 1334: reason = packet_get_int();
1335: if (packet_remaining() > 0) {
1336: msg = packet_get_string(NULL);
1337: lang = packet_get_string(NULL);
1338: }
1.48 markus 1339: packet_done();
1.86 markus 1340: log("channel_open_failure: %d: reason %d %s", id,
1341: reason, msg ? msg : "<no additional info>");
1342: if (msg != NULL)
1343: xfree(msg);
1344: if (lang != NULL)
1345: xfree(lang);
1.44 markus 1346: }
1.25 markus 1347: /* Free the channel. This will also close the socket. */
1.41 markus 1348: channel_free(id);
1.1 deraadt 1349: }
1350:
1.44 markus 1351: void
1.69 markus 1352: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1353: {
1354: int id;
1355: Channel *c;
1356:
1357: id = packet_get_int();
1358: c = channel_lookup(id);
1359:
1360: if (c == NULL ||
1361: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1362: packet_disconnect("Received request for "
1363: "non-open channel %d.", id);
1364: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1365: debug2("callback start");
1.44 markus 1366: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1367: debug2("callback done");
1.44 markus 1368: } else {
1369: char *service = packet_get_string(NULL);
1370: debug("channel: %d rcvd request for %s", c->self, service);
1.70 markus 1371: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1372: xfree(service);
1373: }
1374: }
1375:
1.49 markus 1376: void
1.69 markus 1377: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1378: {
1379: Channel *c;
1380: int id, adjust;
1381:
1382: if (!compat20)
1383: return;
1384:
1385: /* Get the channel number and verify it. */
1386: id = packet_get_int();
1387: c = channel_lookup(id);
1388:
1389: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1390: log("Received window adjust for "
1391: "non-open channel %d.", id);
1392: return;
1393: }
1394: adjust = packet_get_int();
1.48 markus 1395: packet_done();
1.70 markus 1396: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1397: c->remote_window += adjust;
1398: }
1399:
1.27 markus 1400: /*
1401: * Stops listening for channels, and removes any unix domain sockets that we
1402: * might have.
1403: */
1.1 deraadt 1404:
1.49 markus 1405: void
1.25 markus 1406: channel_stop_listening()
1.1 deraadt 1407: {
1.25 markus 1408: int i;
1409: for (i = 0; i < channels_alloc; i++) {
1410: switch (channels[i].type) {
1411: case SSH_CHANNEL_AUTH_SOCKET:
1412: close(channels[i].sock);
1.76 markus 1413: unlink(channels[i].path);
1.25 markus 1414: channel_free(i);
1415: break;
1416: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1417: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1418: case SSH_CHANNEL_X11_LISTENER:
1419: close(channels[i].sock);
1420: channel_free(i);
1421: break;
1422: default:
1423: break;
1424: }
1.1 deraadt 1425: }
1426: }
1427:
1.27 markus 1428: /*
1.52 markus 1429: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1430: * descriptors after a fork.
1431: */
1.1 deraadt 1432:
1.49 markus 1433: void
1.25 markus 1434: channel_close_all()
1.1 deraadt 1435: {
1.25 markus 1436: int i;
1.52 markus 1437: for (i = 0; i < channels_alloc; i++)
1.25 markus 1438: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1439: channel_close_fds(&channels[i]);
1.1 deraadt 1440: }
1441:
1442: /* Returns true if any channel is still open. */
1443:
1.49 markus 1444: int
1.25 markus 1445: channel_still_open()
1.1 deraadt 1446: {
1.77 markus 1447: u_int i;
1.25 markus 1448: for (i = 0; i < channels_alloc; i++)
1449: switch (channels[i].type) {
1450: case SSH_CHANNEL_FREE:
1451: case SSH_CHANNEL_X11_LISTENER:
1452: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1453: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1454: case SSH_CHANNEL_CLOSED:
1455: case SSH_CHANNEL_AUTH_SOCKET:
1.75 markus 1456: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1457: continue;
1.44 markus 1458: case SSH_CHANNEL_LARVAL:
1459: if (!compat20)
1460: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1461: continue;
1.25 markus 1462: case SSH_CHANNEL_OPENING:
1463: case SSH_CHANNEL_OPEN:
1464: case SSH_CHANNEL_X11_OPEN:
1465: return 1;
1466: case SSH_CHANNEL_INPUT_DRAINING:
1467: case SSH_CHANNEL_OUTPUT_DRAINING:
1468: if (!compat13)
1469: fatal("cannot happen: OUT_DRAIN");
1470: return 1;
1471: default:
1472: fatal("channel_still_open: bad channel type %d", channels[i].type);
1473: /* NOTREACHED */
1474: }
1475: return 0;
1.1 deraadt 1476: }
1477:
1.27 markus 1478: /*
1479: * Returns a message describing the currently open forwarded connections,
1480: * suitable for sending to the client. The message contains crlf pairs for
1481: * newlines.
1482: */
1.1 deraadt 1483:
1.25 markus 1484: char *
1485: channel_open_message()
1.1 deraadt 1486: {
1.25 markus 1487: Buffer buffer;
1488: int i;
1489: char buf[512], *cp;
1490:
1491: buffer_init(&buffer);
1492: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1493: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1494: for (i = 0; i < channels_alloc; i++) {
1495: Channel *c = &channels[i];
1496: switch (c->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:
1503: continue;
1.44 markus 1504: case SSH_CHANNEL_LARVAL:
1.25 markus 1505: case SSH_CHANNEL_OPENING:
1.75 markus 1506: case SSH_CHANNEL_CONNECTING:
1.25 markus 1507: case SSH_CHANNEL_OPEN:
1508: case SSH_CHANNEL_X11_OPEN:
1509: case SSH_CHANNEL_INPUT_DRAINING:
1510: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1511: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1512: c->self, c->remote_name,
1513: c->type, c->remote_id,
1514: c->istate, buffer_len(&c->input),
1.41 markus 1515: c->ostate, buffer_len(&c->output),
1516: c->rfd, c->wfd);
1.25 markus 1517: buffer_append(&buffer, buf, strlen(buf));
1518: continue;
1519: default:
1.41 markus 1520: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1521: /* NOTREACHED */
1522: }
1523: }
1524: buffer_append(&buffer, "\0", 1);
1525: cp = xstrdup(buffer_ptr(&buffer));
1526: buffer_free(&buffer);
1527: return cp;
1.1 deraadt 1528: }
1529:
1.27 markus 1530: /*
1531: * Initiate forwarding of connections to local port "port" through the secure
1532: * channel to host:port from remote side.
1533: */
1.87 markus 1534: int
1.73 markus 1535: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1536: u_short port_to_connect, int gateway_ports)
1537: {
1.87 markus 1538: return channel_request_forwarding(
1.73 markus 1539: NULL, listen_port,
1540: host_to_connect, port_to_connect,
1541: gateway_ports, /*remote_fwd*/ 0);
1542: }
1.1 deraadt 1543:
1.73 markus 1544: /*
1545: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1546: * (SSH_CHANNEL_RPORT_LISTENER).
1547: */
1.87 markus 1548: int
1.73 markus 1549: channel_request_forwarding(
1550: const char *listen_address, u_short listen_port,
1551: const char *host_to_connect, u_short port_to_connect,
1552: int gateway_ports, int remote_fwd)
1.25 markus 1553: {
1.73 markus 1554: int success, ch, sock, on = 1, ctype;
1.35 markus 1555: struct addrinfo hints, *ai, *aitop;
1556: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1557: const char *host;
1.28 markus 1558: struct linger linger;
1.25 markus 1559:
1.87 markus 1560: success = 0;
1561:
1.73 markus 1562: if (remote_fwd) {
1563: host = listen_address;
1564: ctype = SSH_CHANNEL_RPORT_LISTENER;
1565: } else {
1566: host = host_to_connect;
1567: ctype =SSH_CHANNEL_PORT_LISTENER;
1568: }
1569:
1.87 markus 1570: if (strlen(host) > sizeof(channels[0].path) - 1) {
1571: error("Forward host name too long.");
1572: return success;
1573: }
1.25 markus 1574:
1.73 markus 1575: /* XXX listen_address is currently ignored */
1.28 markus 1576: /*
1.35 markus 1577: * getaddrinfo returns a loopback address if the hostname is
1578: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1579: */
1.35 markus 1580: memset(&hints, 0, sizeof(hints));
1581: hints.ai_family = IPv4or6;
1582: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1583: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1584: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1585: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1586: packet_disconnect("getaddrinfo: fatal error");
1587:
1588: for (ai = aitop; ai; ai = ai->ai_next) {
1589: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1590: continue;
1591: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1592: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1593: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1594: continue;
1595: }
1596: /* Create a port to listen for the host. */
1597: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1598: if (sock < 0) {
1599: /* this is no error since kernel may not support ipv6 */
1600: verbose("socket: %.100s", strerror(errno));
1601: continue;
1602: }
1603: /*
1604: * Set socket options. We would like the socket to disappear
1605: * as soon as it has been closed for whatever reason.
1606: */
1607: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1608: linger.l_onoff = 1;
1609: linger.l_linger = 5;
1610: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1611: debug("Local forwarding listening on %s port %s.", ntop, strport);
1612:
1613: /* Bind the socket to the address. */
1614: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1615: /* address can be in use ipv6 address is already bound */
1616: verbose("bind: %.100s", strerror(errno));
1617: close(sock);
1618: continue;
1619: }
1620: /* Start listening for connections on the socket. */
1621: if (listen(sock, 5) < 0) {
1622: error("listen: %.100s", strerror(errno));
1623: close(sock);
1624: continue;
1625: }
1626: /* Allocate a channel number for the socket. */
1.73 markus 1627: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1628: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1629: 0, xstrdup("port listener"), 1);
1.35 markus 1630: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1631: channels[ch].host_port = port_to_connect;
1632: channels[ch].listening_port = listen_port;
1.35 markus 1633: success = 1;
1634: }
1635: if (success == 0)
1.87 markus 1636: error("channel_request_forwarding: cannot listen to port: %d",
1637: listen_port);
1.35 markus 1638: freeaddrinfo(aitop);
1.87 markus 1639: return success;
1.25 markus 1640: }
1.1 deraadt 1641:
1.27 markus 1642: /*
1643: * Initiate forwarding of connections to port "port" on remote host through
1644: * the secure channel to host:port from local side.
1645: */
1.1 deraadt 1646:
1.49 markus 1647: void
1.73 markus 1648: channel_request_remote_forwarding(u_short listen_port,
1649: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1650: {
1.73 markus 1651: int payload_len, type, success = 0;
1652:
1.25 markus 1653: /* Record locally that connection to this host/port is permitted. */
1654: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1655: fatal("channel_request_remote_forwarding: too many forwards");
1656:
1657: /* Send the forward request to the remote side. */
1.44 markus 1658: if (compat20) {
1659: const char *address_to_bind = "0.0.0.0";
1660: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1661: packet_put_cstring("tcpip-forward");
1662: packet_put_char(0); /* boolean: want reply */
1663: packet_put_cstring(address_to_bind);
1664: packet_put_int(listen_port);
1.73 markus 1665: packet_send();
1666: packet_write_wait();
1667: /* Assume that server accepts the request */
1668: success = 1;
1.44 markus 1669: } else {
1670: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1671: packet_put_int(listen_port);
1672: packet_put_cstring(host_to_connect);
1.44 markus 1673: packet_put_int(port_to_connect);
1674: packet_send();
1675: packet_write_wait();
1.73 markus 1676:
1677: /* Wait for response from the remote side. */
1678: type = packet_read(&payload_len);
1679: switch (type) {
1680: case SSH_SMSG_SUCCESS:
1681: success = 1;
1682: break;
1683: case SSH_SMSG_FAILURE:
1684: log("Warning: Server denied remote port forwarding.");
1685: break;
1686: default:
1687: /* Unknown packet */
1688: packet_disconnect("Protocol error for port forward request:"
1689: "received packet type %d.", type);
1690: }
1691: }
1692: if (success) {
1693: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1694: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1695: permitted_opens[num_permitted_opens].listen_port = listen_port;
1696: num_permitted_opens++;
1.44 markus 1697: }
1.1 deraadt 1698: }
1699:
1.27 markus 1700: /*
1701: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1702: * listening for the port, and sends back a success reply (or disconnect
1703: * message if there was an error). This never returns if there was an error.
1704: */
1.1 deraadt 1705:
1.49 markus 1706: void
1.56 markus 1707: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1708: {
1.31 markus 1709: u_short port, host_port;
1.25 markus 1710: char *hostname;
1.1 deraadt 1711:
1.25 markus 1712: /* Get arguments from the packet. */
1713: port = packet_get_int();
1714: hostname = packet_get_string(NULL);
1715: host_port = packet_get_int();
1716:
1.27 markus 1717: /*
1718: * Check that an unprivileged user is not trying to forward a
1719: * privileged port.
1720: */
1.25 markus 1721: if (port < IPPORT_RESERVED && !is_root)
1722: packet_disconnect("Requested forwarding of port %d but user is not root.",
1723: port);
1.73 markus 1724: /* Initiate forwarding */
1.56 markus 1725: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1726:
1727: /* Free the argument string. */
1728: xfree(hostname);
1.1 deraadt 1729: }
1730:
1.41 markus 1731: /* XXX move to aux.c */
1732: int
1733: channel_connect_to(const char *host, u_short host_port)
1734: {
1735: struct addrinfo hints, *ai, *aitop;
1736: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1737: int gaierr;
1738: int sock = -1;
1739:
1740: memset(&hints, 0, sizeof(hints));
1741: hints.ai_family = IPv4or6;
1742: hints.ai_socktype = SOCK_STREAM;
1743: snprintf(strport, sizeof strport, "%d", host_port);
1744: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1745: error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
1746: return -1;
1747: }
1748: for (ai = aitop; ai; ai = ai->ai_next) {
1749: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1750: continue;
1751: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1752: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1753: error("channel_connect_to: getnameinfo failed");
1754: continue;
1755: }
1756: /* Create the socket. */
1757: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1758: if (sock < 0) {
1759: error("socket: %.100s", strerror(errno));
1760: continue;
1761: }
1.80 markus 1762: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 1763: fatal("connect_to: F_SETFL: %s", strerror(errno));
1.41 markus 1764: /* Connect to the host/port. */
1.75 markus 1765: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
1766: errno != EINPROGRESS) {
1.41 markus 1767: error("connect %.100s port %s: %.100s", ntop, strport,
1768: strerror(errno));
1769: close(sock);
1770: continue; /* fail -- try next */
1771: }
1772: break; /* success */
1773:
1774: }
1775: freeaddrinfo(aitop);
1776: if (!ai) {
1777: error("connect %.100s port %d: failed.", host, host_port);
1778: return -1;
1779: }
1780: /* success */
1781: return sock;
1782: }
1.73 markus 1783: int
1784: channel_connect_by_listen_adress(u_short listen_port)
1785: {
1786: int i;
1787: for (i = 0; i < num_permitted_opens; i++)
1788: if (permitted_opens[i].listen_port == listen_port)
1789: return channel_connect_to(
1790: permitted_opens[i].host_to_connect,
1791: permitted_opens[i].port_to_connect);
1.74 markus 1792: error("WARNING: Server requests forwarding for unknown listen_port %d",
1793: listen_port);
1.73 markus 1794: return -1;
1795: }
1796:
1.27 markus 1797: /*
1798: * This is called after receiving PORT_OPEN message. This attempts to
1799: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
1800: * or CHANNEL_OPEN_FAILURE.
1801: */
1.1 deraadt 1802:
1.49 markus 1803: void
1.69 markus 1804: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 1805: {
1.31 markus 1806: u_short host_port;
1.25 markus 1807: char *host, *originator_string;
1.41 markus 1808: int remote_channel, sock = -1, newch, i, denied;
1.77 markus 1809: u_int host_len, originator_len;
1.25 markus 1810:
1811: /* Get remote channel number. */
1812: remote_channel = packet_get_int();
1813:
1814: /* Get host name to connect to. */
1815: host = packet_get_string(&host_len);
1816:
1817: /* Get port to connect to. */
1818: host_port = packet_get_int();
1819:
1820: /* Get remote originator name. */
1.29 markus 1821: if (have_hostname_in_open) {
1.25 markus 1822: originator_string = packet_get_string(&originator_len);
1.29 markus 1823: originator_len += 4; /* size of packet_int */
1824: } else {
1.25 markus 1825: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 1826: originator_len = 0; /* no originator supplied */
1827: }
1.25 markus 1828:
1.41 markus 1829: packet_integrity_check(plen,
1830: 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
1.25 markus 1831:
1832: /* Check if opening that port is permitted. */
1.41 markus 1833: denied = 0;
1.25 markus 1834: if (!all_opens_permitted) {
1835: /* Go trough all permitted ports. */
1836: for (i = 0; i < num_permitted_opens; i++)
1.41 markus 1837: if (permitted_opens[i].port_to_connect == host_port &&
1838: strcmp(permitted_opens[i].host_to_connect, host) == 0)
1.25 markus 1839: break;
1840:
1841: /* Check if we found the requested port among those permitted. */
1842: if (i >= num_permitted_opens) {
1843: /* The port is not permitted. */
1844: log("Received request to connect to %.100s:%d, but the request was denied.",
1845: host, host_port);
1.41 markus 1846: denied = 1;
1.25 markus 1847: }
1848: }
1.41 markus 1849: sock = denied ? -1 : channel_connect_to(host, host_port);
1850: if (sock > 0) {
1851: /* Allocate a channel for this connection. */
1.75 markus 1852: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
1853: sock, originator_string);
1854: /*XXX delay answer? */
1.41 markus 1855: channels[newch].remote_id = remote_channel;
1856:
1857: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1858: packet_put_int(remote_channel);
1859: packet_put_int(newch);
1860: packet_send();
1861: } else {
1862: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1863: packet_put_int(remote_channel);
1864: packet_send();
1.25 markus 1865: }
1866: xfree(host);
1.1 deraadt 1867: }
1868:
1.27 markus 1869: /*
1870: * Creates an internet domain socket for listening for X11 connections.
1871: * Returns a suitable value for the DISPLAY variable, or NULL if an error
1872: * occurs.
1873: */
1.1 deraadt 1874:
1.35 markus 1875: #define NUM_SOCKS 10
1876:
1.25 markus 1877: char *
1.33 markus 1878: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 1879: {
1.31 markus 1880: int display_number, sock;
1881: u_short port;
1.35 markus 1882: struct addrinfo hints, *ai, *aitop;
1883: char strport[NI_MAXSERV];
1884: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1885: char display[512];
1.25 markus 1886: char hostname[MAXHOSTNAMELEN];
1887:
1.33 markus 1888: for (display_number = x11_display_offset;
1.25 markus 1889: display_number < MAX_DISPLAYS;
1890: display_number++) {
1891: port = 6000 + display_number;
1.35 markus 1892: memset(&hints, 0, sizeof(hints));
1893: hints.ai_family = IPv4or6;
1.36 markus 1894: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 1895: hints.ai_socktype = SOCK_STREAM;
1896: snprintf(strport, sizeof strport, "%d", port);
1897: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1898: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 1899: return NULL;
1900: }
1.35 markus 1901: for (ai = aitop; ai; ai = ai->ai_next) {
1902: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1903: continue;
1904: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1905: if (sock < 0) {
1906: error("socket: %.100s", strerror(errno));
1907: return NULL;
1908: }
1909: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1910: debug("bind port %d: %.100s", port, strerror(errno));
1911: shutdown(sock, SHUT_RDWR);
1912: close(sock);
1913: for (n = 0; n < num_socks; n++) {
1914: shutdown(socks[n], SHUT_RDWR);
1915: close(socks[n]);
1916: }
1917: num_socks = 0;
1918: break;
1919: }
1920: socks[num_socks++] = sock;
1921: if (num_socks == NUM_SOCKS)
1922: break;
1.25 markus 1923: }
1.83 stevesk 1924: freeaddrinfo(aitop);
1.35 markus 1925: if (num_socks > 0)
1926: break;
1.25 markus 1927: }
1928: if (display_number >= MAX_DISPLAYS) {
1929: error("Failed to allocate internet-domain X11 display socket.");
1930: return NULL;
1931: }
1932: /* Start listening for connections on the socket. */
1.35 markus 1933: for (n = 0; n < num_socks; n++) {
1934: sock = socks[n];
1935: if (listen(sock, 5) < 0) {
1936: error("listen: %.100s", strerror(errno));
1937: shutdown(sock, SHUT_RDWR);
1938: close(sock);
1939: return NULL;
1940: }
1.25 markus 1941: }
1.35 markus 1942:
1.25 markus 1943: /* Set up a suitable value for the DISPLAY variable. */
1944: if (gethostname(hostname, sizeof(hostname)) < 0)
1945: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 1946: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 1947: display_number, screen_number);
1948:
1.35 markus 1949: /* Allocate a channel for each socket. */
1950: for (n = 0; n < num_socks; n++) {
1951: sock = socks[n];
1.51 markus 1952: (void) channel_new("x11 listener",
1953: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
1954: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 1955: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 1956: }
1.1 deraadt 1957:
1.25 markus 1958: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 1959: return xstrdup(display);
1.1 deraadt 1960: }
1961:
1962: #ifndef X_UNIX_PATH
1963: #define X_UNIX_PATH "/tmp/.X11-unix/X"
1964: #endif
1965:
1966: static
1967: int
1.77 markus 1968: connect_local_xsocket(u_int dnr)
1.1 deraadt 1969: {
1.25 markus 1970: static const char *const x_sockets[] = {
1971: X_UNIX_PATH "%u",
1972: "/var/X/.X11-unix/X" "%u",
1973: "/usr/spool/sockets/X11/" "%u",
1974: NULL
1975: };
1976: int sock;
1977: struct sockaddr_un addr;
1978: const char *const * path;
1979:
1980: for (path = x_sockets; *path; ++path) {
1981: sock = socket(AF_UNIX, SOCK_STREAM, 0);
1982: if (sock < 0)
1983: error("socket: %.100s", strerror(errno));
1984: memset(&addr, 0, sizeof(addr));
1985: addr.sun_family = AF_UNIX;
1986: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
1987: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
1988: return sock;
1989: close(sock);
1990: }
1991: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
1992: return -1;
1.1 deraadt 1993: }
1994:
1.51 markus 1995: int
1996: x11_connect_display(void)
1.1 deraadt 1997: {
1.51 markus 1998: int display_number, sock = 0;
1.25 markus 1999: const char *display;
1.51 markus 2000: char buf[1024], *cp;
1.35 markus 2001: struct addrinfo hints, *ai, *aitop;
2002: char strport[NI_MAXSERV];
2003: int gaierr;
1.25 markus 2004:
2005: /* Try to open a socket for the local X server. */
2006: display = getenv("DISPLAY");
2007: if (!display) {
2008: error("DISPLAY not set.");
1.51 markus 2009: return -1;
1.25 markus 2010: }
1.27 markus 2011: /*
2012: * Now we decode the value of the DISPLAY variable and make a
2013: * connection to the real X server.
2014: */
2015:
2016: /*
2017: * Check if it is a unix domain socket. Unix domain displays are in
2018: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2019: */
1.25 markus 2020: if (strncmp(display, "unix:", 5) == 0 ||
2021: display[0] == ':') {
2022: /* Connect to the unix domain socket. */
2023: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2024: error("Could not parse display number from DISPLAY: %.100s",
2025: display);
1.51 markus 2026: return -1;
1.25 markus 2027: }
2028: /* Create a socket. */
2029: sock = connect_local_xsocket(display_number);
2030: if (sock < 0)
1.51 markus 2031: return -1;
1.25 markus 2032:
2033: /* OK, we now have a connection to the display. */
1.51 markus 2034: return sock;
1.25 markus 2035: }
1.27 markus 2036: /*
2037: * Connect to an inet socket. The DISPLAY value is supposedly
2038: * hostname:d[.s], where hostname may also be numeric IP address.
2039: */
1.25 markus 2040: strncpy(buf, display, sizeof(buf));
2041: buf[sizeof(buf) - 1] = 0;
2042: cp = strchr(buf, ':');
2043: if (!cp) {
2044: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2045: return -1;
1.25 markus 2046: }
2047: *cp = 0;
1.27 markus 2048: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2049: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2050: error("Could not parse display number from DISPLAY: %.100s",
2051: display);
1.51 markus 2052: return -1;
1.25 markus 2053: }
1.35 markus 2054:
2055: /* Look up the host address */
2056: memset(&hints, 0, sizeof(hints));
2057: hints.ai_family = IPv4or6;
2058: hints.ai_socktype = SOCK_STREAM;
2059: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2060: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2061: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2062: return -1;
1.25 markus 2063: }
1.35 markus 2064: for (ai = aitop; ai; ai = ai->ai_next) {
2065: /* Create a socket. */
2066: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2067: if (sock < 0) {
2068: debug("socket: %.100s", strerror(errno));
1.41 markus 2069: continue;
2070: }
2071: /* Connect it to the display. */
2072: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2073: debug("connect %.100s port %d: %.100s", buf,
2074: 6000 + display_number, strerror(errno));
2075: close(sock);
2076: continue;
2077: }
2078: /* Success */
2079: break;
1.35 markus 2080: }
2081: freeaddrinfo(aitop);
2082: if (!ai) {
1.49 markus 2083: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2084: strerror(errno));
1.51 markus 2085: return -1;
1.25 markus 2086: }
1.51 markus 2087: return sock;
2088: }
2089:
2090: /*
2091: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2092: * the remote channel number. We should do whatever we want, and respond
2093: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2094: */
2095:
2096: void
1.69 markus 2097: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2098: {
2099: int remote_channel, sock = 0, newch;
2100: char *remote_host;
1.77 markus 2101: u_int remote_len;
1.25 markus 2102:
1.51 markus 2103: /* Get remote channel number. */
2104: remote_channel = packet_get_int();
2105:
2106: /* Get remote originator name. */
2107: if (have_hostname_in_open) {
2108: remote_host = packet_get_string(&remote_len);
2109: remote_len += 4;
2110: } else {
2111: remote_host = xstrdup("unknown (remote did not supply name)");
2112: remote_len = 0;
2113: }
1.25 markus 2114:
1.51 markus 2115: debug("Received X11 open request.");
2116: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2117:
1.51 markus 2118: /* Obtain a connection to the real X display. */
2119: sock = x11_connect_display();
2120: if (sock == -1) {
2121: /* Send refusal to the remote host. */
2122: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2123: packet_put_int(remote_channel);
2124: packet_send();
2125: } else {
2126: /* Allocate a channel for this connection. */
2127: newch = channel_allocate(
2128: (x11_saved_proto == NULL) ?
2129: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2130: sock, remote_host);
2131: channels[newch].remote_id = remote_channel;
1.25 markus 2132:
1.51 markus 2133: /* Send a confirmation to the remote host. */
2134: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2135: packet_put_int(remote_channel);
2136: packet_put_int(newch);
2137: packet_send();
2138: }
1.72 markus 2139: }
2140:
2141: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2142: void
2143: deny_input_open(int type, int plen, void *ctxt)
2144: {
2145: int rchan = packet_get_int();
2146: switch(type){
2147: case SSH_SMSG_AGENT_OPEN:
2148: error("Warning: ssh server tried agent forwarding.");
2149: break;
2150: case SSH_SMSG_X11_OPEN:
2151: error("Warning: ssh server tried X11 forwarding.");
2152: break;
2153: default:
2154: error("deny_input_open: type %d plen %d", type, plen);
2155: break;
2156: }
2157: error("Warning: this is probably a break in attempt by a malicious server.");
2158: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2159: packet_put_int(rchan);
2160: packet_send();
1.1 deraadt 2161: }
2162:
1.27 markus 2163: /*
2164: * Requests forwarding of X11 connections, generates fake authentication
2165: * data, and enables authentication spoofing.
2166: */
1.1 deraadt 2167:
1.49 markus 2168: void
1.51 markus 2169: x11_request_forwarding_with_spoofing(int client_session_id,
2170: const char *proto, const char *data)
1.1 deraadt 2171: {
1.77 markus 2172: u_int data_len = (u_int) strlen(data) / 2;
2173: u_int i, value;
1.25 markus 2174: char *new_data;
2175: int screen_number;
2176: const char *cp;
2177: u_int32_t rand = 0;
2178:
2179: cp = getenv("DISPLAY");
2180: if (cp)
2181: cp = strchr(cp, ':');
2182: if (cp)
2183: cp = strchr(cp, '.');
2184: if (cp)
2185: screen_number = atoi(cp + 1);
2186: else
2187: screen_number = 0;
2188:
2189: /* Save protocol name. */
2190: x11_saved_proto = xstrdup(proto);
2191:
1.27 markus 2192: /*
2193: * Extract real authentication data and generate fake data of the
2194: * same length.
2195: */
1.25 markus 2196: x11_saved_data = xmalloc(data_len);
2197: x11_fake_data = xmalloc(data_len);
2198: for (i = 0; i < data_len; i++) {
2199: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2200: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2201: if (i % 4 == 0)
2202: rand = arc4random();
2203: x11_saved_data[i] = value;
2204: x11_fake_data[i] = rand & 0xff;
2205: rand >>= 8;
2206: }
2207: x11_saved_data_len = data_len;
2208: x11_fake_data_len = data_len;
2209:
2210: /* Convert the fake data into hex. */
2211: new_data = xmalloc(2 * data_len + 1);
2212: for (i = 0; i < data_len; i++)
1.77 markus 2213: sprintf(new_data + 2 * i, "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2214:
2215: /* Send the request packet. */
1.51 markus 2216: if (compat20) {
2217: channel_request_start(client_session_id, "x11-req", 0);
2218: packet_put_char(0); /* XXX bool single connection */
2219: } else {
2220: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2221: }
2222: packet_put_cstring(proto);
2223: packet_put_cstring(new_data);
1.25 markus 2224: packet_put_int(screen_number);
2225: packet_send();
2226: packet_write_wait();
2227: xfree(new_data);
1.1 deraadt 2228: }
2229:
2230: /* Sends a message to the server to request authentication fd forwarding. */
2231:
1.49 markus 2232: void
1.25 markus 2233: auth_request_forwarding()
1.1 deraadt 2234: {
1.25 markus 2235: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2236: packet_send();
2237: packet_write_wait();
1.1 deraadt 2238: }
2239:
1.27 markus 2240: /*
2241: * Returns the name of the forwarded authentication socket. Returns NULL if
2242: * there is no forwarded authentication socket. The returned value points to
2243: * a static buffer.
2244: */
1.1 deraadt 2245:
1.25 markus 2246: char *
2247: auth_get_socket_name()
1.1 deraadt 2248: {
1.25 markus 2249: return channel_forwarded_auth_socket_name;
1.1 deraadt 2250: }
2251:
1.12 markus 2252: /* removes the agent forwarding socket */
2253:
1.49 markus 2254: void
1.25 markus 2255: cleanup_socket(void)
2256: {
1.78 markus 2257: unlink(channel_forwarded_auth_socket_name);
1.25 markus 2258: rmdir(channel_forwarded_auth_socket_dir);
1.12 markus 2259: }
2260:
1.27 markus 2261: /*
1.59 markus 2262: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2263: * This starts forwarding authentication requests.
2264: */
1.1 deraadt 2265:
1.59 markus 2266: int
1.25 markus 2267: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2268: {
1.25 markus 2269: int sock, newch;
2270: struct sockaddr_un sunaddr;
2271:
2272: if (auth_get_socket_name() != NULL)
2273: fatal("Protocol error: authentication forwarding requested twice.");
2274:
2275: /* Temporarily drop privileged uid for mkdir/bind. */
2276: temporarily_use_uid(pw->pw_uid);
2277:
2278: /* Allocate a buffer for the socket name, and format the name. */
2279: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2280: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2281: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2282:
2283: /* Create private directory for socket */
1.59 markus 2284: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2285: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2286: strerror(errno));
2287: restore_uid();
2288: xfree(channel_forwarded_auth_socket_name);
2289: xfree(channel_forwarded_auth_socket_dir);
2290: channel_forwarded_auth_socket_name = NULL;
2291: channel_forwarded_auth_socket_dir = NULL;
2292: return 0;
2293: }
1.25 markus 2294: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2295: channel_forwarded_auth_socket_dir, (int) getpid());
2296:
2297: if (atexit(cleanup_socket) < 0) {
2298: int saved = errno;
2299: cleanup_socket();
2300: packet_disconnect("socket: %.100s", strerror(saved));
2301: }
2302: /* Create the socket. */
2303: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2304: if (sock < 0)
2305: packet_disconnect("socket: %.100s", strerror(errno));
2306:
2307: /* Bind it to the name. */
2308: memset(&sunaddr, 0, sizeof(sunaddr));
2309: sunaddr.sun_family = AF_UNIX;
2310: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2311: sizeof(sunaddr.sun_path));
2312:
2313: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2314: packet_disconnect("bind: %.100s", strerror(errno));
2315:
2316: /* Restore the privileged uid. */
2317: restore_uid();
2318:
2319: /* Start listening on the socket. */
2320: if (listen(sock, 5) < 0)
2321: packet_disconnect("listen: %.100s", strerror(errno));
2322:
2323: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2324: newch = channel_new("auth socket",
2325: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2326: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2327: 0, xstrdup("auth socket"), 1);
2328:
1.32 deraadt 2329: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2330: sizeof(channels[newch].path));
1.59 markus 2331: return 1;
1.1 deraadt 2332: }
2333:
2334: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2335:
1.49 markus 2336: void
1.69 markus 2337: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2338: {
1.25 markus 2339: int remch, sock, newch;
2340: char *dummyname;
1.41 markus 2341:
2342: packet_integrity_check(plen, 4, type);
1.25 markus 2343:
2344: /* Read the remote channel number from the message. */
2345: remch = packet_get_int();
2346:
1.27 markus 2347: /*
2348: * Get a connection to the local authentication agent (this may again
2349: * get forwarded).
2350: */
1.25 markus 2351: sock = ssh_get_authentication_socket();
2352:
1.27 markus 2353: /*
2354: * If we could not connect the agent, send an error message back to
2355: * the server. This should never happen unless the agent dies,
2356: * because authentication forwarding is only enabled if we have an
2357: * agent.
2358: */
1.25 markus 2359: if (sock < 0) {
2360: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2361: packet_put_int(remch);
2362: packet_send();
2363: return;
2364: }
2365: debug("Forwarding authentication connection.");
1.1 deraadt 2366:
1.27 markus 2367: /*
2368: * Dummy host name. This will be freed when the channel is freed; it
2369: * will still be valid in the packet_put_string below since the
2370: * channel cannot yet be freed at that point.
2371: */
1.25 markus 2372: dummyname = xstrdup("authentication agent connection");
2373:
2374: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2375: channels[newch].remote_id = remch;
2376:
2377: /* Send a confirmation to the remote host. */
2378: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2379: packet_put_int(remch);
2380: packet_put_int(newch);
1.44 markus 2381: packet_send();
2382: }
2383:
2384: void
1.51 markus 2385: channel_start_open(int id)
1.44 markus 2386: {
2387: Channel *c = channel_lookup(id);
2388: if (c == NULL) {
2389: log("channel_open: %d: bad id", id);
2390: return;
2391: }
1.51 markus 2392: debug("send channel open %d", id);
1.44 markus 2393: packet_start(SSH2_MSG_CHANNEL_OPEN);
2394: packet_put_cstring(c->ctype);
2395: packet_put_int(c->self);
2396: packet_put_int(c->local_window);
2397: packet_put_int(c->local_maxpacket);
1.51 markus 2398: }
2399: void
2400: channel_open(int id)
2401: {
2402: /* XXX REMOVE ME */
2403: channel_start_open(id);
1.44 markus 2404: packet_send();
2405: }
2406: void
2407: channel_request(int id, char *service, int wantconfirm)
2408: {
2409: channel_request_start(id, service, wantconfirm);
2410: packet_send();
2411: debug("channel request %d: %s", id, service) ;
2412: }
2413: void
2414: channel_request_start(int id, char *service, int wantconfirm)
2415: {
2416: Channel *c = channel_lookup(id);
2417: if (c == NULL) {
2418: log("channel_request: %d: bad id", id);
2419: return;
2420: }
2421: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2422: packet_put_int(c->remote_id);
2423: packet_put_cstring(service);
2424: packet_put_char(wantconfirm);
2425: }
2426: void
2427: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2428: {
2429: Channel *c = channel_lookup(id);
2430: if (c == NULL) {
2431: log("channel_register_callback: %d: bad id", id);
2432: return;
2433: }
2434: c->cb_event = mtype;
2435: c->cb_fn = fn;
2436: c->cb_arg = arg;
2437: }
2438: void
2439: channel_register_cleanup(int id, channel_callback_fn *fn)
2440: {
2441: Channel *c = channel_lookup(id);
2442: if (c == NULL) {
2443: log("channel_register_cleanup: %d: bad id", id);
2444: return;
2445: }
2446: c->dettach_user = fn;
2447: }
2448: void
2449: channel_cancel_cleanup(int id)
2450: {
2451: Channel *c = channel_lookup(id);
2452: if (c == NULL) {
2453: log("channel_cancel_cleanup: %d: bad id", id);
2454: return;
2455: }
2456: c->dettach_user = NULL;
1.65 markus 2457: }
2458: void
2459: channel_register_filter(int id, channel_filter_fn *fn)
2460: {
2461: Channel *c = channel_lookup(id);
2462: if (c == NULL) {
2463: log("channel_register_filter: %d: bad id", id);
2464: return;
2465: }
2466: c->input_filter = fn;
1.44 markus 2467: }
2468:
2469: void
1.71 markus 2470: channel_set_fds(int id, int rfd, int wfd, int efd,
2471: int extusage, int nonblock)
1.44 markus 2472: {
2473: Channel *c = channel_lookup(id);
2474: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2475: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2476: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2477: c->type = SSH_CHANNEL_OPEN;
2478: /* XXX window size? */
1.68 markus 2479: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2480: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2481: packet_put_int(c->remote_id);
2482: packet_put_int(c->local_window);
1.25 markus 2483: packet_send();
1.1 deraadt 2484: }
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