Annotation of src/usr.bin/ssh/channels.c, Revision 1.321
1.321 ! djm 1: /* $OpenBSD: channels.c,v 1.320 2013/04/06 16:07:00 markus Exp $ */
1.1 deraadt 2: /*
1.26 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * This file contains functions for generic socket connection forwarding.
7: * There is also code for initiating connection forwarding for X11 connections,
8: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 9: *
1.67 deraadt 10: * As far as I am concerned, the code I have written for this software
11: * can be used freely for any purpose. Any derived versions of this
12: * software must be clearly marked as such, and if the derived work is
13: * incompatible with the protocol description in the RFC file, it must be
14: * called by a name other than "ssh" or "Secure Shell".
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.156 markus 17: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.67 deraadt 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:
1.265 deraadt 42: #include <sys/types.h>
1.234 stevesk 43: #include <sys/ioctl.h>
1.235 stevesk 44: #include <sys/un.h>
1.251 stevesk 45: #include <sys/socket.h>
1.261 stevesk 46: #include <sys/time.h>
1.275 djm 47: #include <sys/queue.h>
1.251 stevesk 48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.298 dtucker 53: #include <fcntl.h>
1.255 stevesk 54: #include <netdb.h>
1.263 stevesk 55: #include <stdio.h>
1.262 stevesk 56: #include <stdlib.h>
1.260 stevesk 57: #include <string.h>
1.233 stevesk 58: #include <termios.h>
1.256 stevesk 59: #include <unistd.h>
1.265 deraadt 60: #include <stdarg.h>
1.1 deraadt 61:
1.265 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.82 markus 64: #include "ssh1.h"
65: #include "ssh2.h"
1.1 deraadt 66: #include "packet.h"
1.82 markus 67: #include "log.h"
68: #include "misc.h"
1.265 deraadt 69: #include "buffer.h"
1.14 markus 70: #include "channels.h"
71: #include "compat.h"
1.82 markus 72: #include "canohost.h"
1.64 markus 73: #include "key.h"
74: #include "authfd.h"
1.147 stevesk 75: #include "pathnames.h"
1.1 deraadt 76:
1.121 markus 77: /* -- channel core */
1.12 markus 78:
1.27 markus 79: /*
80: * Pointer to an array containing all allocated channels. The array is
81: * dynamically extended as needed.
82: */
1.113 markus 83: static Channel **channels = NULL;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Size of the channel array. All slots of the array must always be
1.113 markus 87: * initialized (at least the type field); unused slots set to NULL
1.27 markus 88: */
1.209 avsm 89: static u_int channels_alloc = 0;
1.1 deraadt 90:
1.27 markus 91: /*
92: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 93: * updated in channel_new.
1.27 markus 94: */
1.84 markus 95: static int channel_max_fd = 0;
1.1 deraadt 96:
97:
1.121 markus 98: /* -- tcp forwarding */
1.1 deraadt 99:
1.27 markus 100: /*
101: * Data structure for storing which hosts are permitted for forward requests.
102: * The local sides of any remote forwards are stored in this array to prevent
103: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
104: * network (which might be behind a firewall).
105: */
1.25 markus 106: typedef struct {
1.41 markus 107: char *host_to_connect; /* Connect to 'host'. */
108: u_short port_to_connect; /* Connect to 'port'. */
109: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 110: } ForwardPermission;
111:
1.257 dtucker 112: /* List of all permitted host/port pairs to connect by the user. */
1.305 djm 113: static ForwardPermission *permitted_opens = NULL;
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
1.305 djm 116: static ForwardPermission *permitted_adm_opens = NULL;
1.257 dtucker 117:
118: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 119: static int num_permitted_opens = 0;
1.257 dtucker 120:
121: /* Number of permitted host/port pair in the array permitted by the admin. */
122: static int num_adm_permitted_opens = 0;
123:
1.314 dtucker 124: /* special-case port number meaning allow any port */
125: #define FWD_PERMIT_ANY_PORT 0
126:
1.27 markus 127: /*
128: * If this is true, all opens are permitted. This is the case on the server
129: * on which we have to trust the client anyway, and the user could do
130: * anything after logging in anyway.
131: */
1.1 deraadt 132: static int all_opens_permitted = 0;
133:
1.121 markus 134:
135: /* -- X11 forwarding */
136:
137: /* Maximum number of fake X11 displays to try. */
138: #define MAX_DISPLAYS 1000
139:
1.219 djm 140: /* Saved X11 local (client) display. */
141: static char *x11_saved_display = NULL;
142:
1.121 markus 143: /* Saved X11 authentication protocol name. */
144: static char *x11_saved_proto = NULL;
145:
146: /* Saved X11 authentication data. This is the real data. */
147: static char *x11_saved_data = NULL;
148: static u_int x11_saved_data_len = 0;
149:
150: /*
151: * Fake X11 authentication data. This is what the server will be sending us;
152: * we should replace any occurrences of this by the real data.
153: */
1.240 deraadt 154: static u_char *x11_fake_data = NULL;
1.121 markus 155: static u_int x11_fake_data_len;
156:
157:
158: /* -- agent forwarding */
159:
160: #define NUM_SOCKS 10
161:
1.82 markus 162: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 163: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 164:
1.121 markus 165: /* helper */
1.127 itojun 166: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 167:
1.276 djm 168: /* non-blocking connect helpers */
169: static int connect_next(struct channel_connect *);
170: static void channel_connect_ctx_free(struct channel_connect *);
171:
1.121 markus 172: /* -- channel core */
1.41 markus 173:
174: Channel *
1.229 markus 175: channel_by_id(int id)
1.41 markus 176: {
177: Channel *c;
1.113 markus 178:
1.209 avsm 179: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 180: logit("channel_by_id: %d: bad id", id);
1.41 markus 181: return NULL;
182: }
1.113 markus 183: c = channels[id];
184: if (c == NULL) {
1.229 markus 185: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 186: return NULL;
187: }
188: return c;
1.55 markus 189: }
190:
1.27 markus 191: /*
1.229 markus 192: * Returns the channel if it is allowed to receive protocol messages.
193: * Private channels, like listening sockets, may not receive messages.
194: */
195: Channel *
196: channel_lookup(int id)
197: {
198: Channel *c;
199:
200: if ((c = channel_by_id(id)) == NULL)
201: return (NULL);
202:
1.237 deraadt 203: switch (c->type) {
1.229 markus 204: case SSH_CHANNEL_X11_OPEN:
205: case SSH_CHANNEL_LARVAL:
206: case SSH_CHANNEL_CONNECTING:
207: case SSH_CHANNEL_DYNAMIC:
208: case SSH_CHANNEL_OPENING:
209: case SSH_CHANNEL_OPEN:
210: case SSH_CHANNEL_INPUT_DRAINING:
211: case SSH_CHANNEL_OUTPUT_DRAINING:
212: return (c);
213: }
214: logit("Non-public channel %d, type %d.", id, c->type);
215: return (NULL);
216: }
217:
218: /*
1.55 markus 219: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 220: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 221: */
1.127 itojun 222: static void
1.71 markus 223: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 224: int extusage, int nonblock, int is_tty)
1.1 deraadt 225: {
1.25 markus 226: /* Update the maximum file descriptor value. */
1.84 markus 227: channel_max_fd = MAX(channel_max_fd, rfd);
228: channel_max_fd = MAX(channel_max_fd, wfd);
229: channel_max_fd = MAX(channel_max_fd, efd);
230:
1.298 dtucker 231: if (rfd != -1)
232: fcntl(rfd, F_SETFD, FD_CLOEXEC);
233: if (wfd != -1 && wfd != rfd)
234: fcntl(wfd, F_SETFD, FD_CLOEXEC);
235: if (efd != -1 && efd != rfd && efd != wfd)
236: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 237:
1.52 markus 238: c->rfd = rfd;
239: c->wfd = wfd;
240: c->sock = (rfd == wfd) ? rfd : -1;
241: c->efd = efd;
242: c->extended_usage = extusage;
1.71 markus 243:
1.282 dtucker 244: if ((c->isatty = is_tty) != 0)
1.194 markus 245: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 246:
1.71 markus 247: /* enable nonblocking mode */
248: if (nonblock) {
249: if (rfd != -1)
250: set_nonblock(rfd);
251: if (wfd != -1)
252: set_nonblock(wfd);
253: if (efd != -1)
254: set_nonblock(efd);
255: }
1.52 markus 256: }
257:
258: /*
259: * Allocate a new channel object and set its type and socket. This will cause
260: * remote_name to be freed.
261: */
1.113 markus 262: Channel *
1.52 markus 263: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 264: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 265: {
1.209 avsm 266: int found;
267: u_int i;
1.52 markus 268: Channel *c;
1.25 markus 269:
270: /* Do initial allocation if this is the first call. */
271: if (channels_alloc == 0) {
272: channels_alloc = 10;
1.242 djm 273: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 274: for (i = 0; i < channels_alloc; i++)
1.113 markus 275: channels[i] = NULL;
1.25 markus 276: }
277: /* Try to find a free slot where to put the new channel. */
278: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 279: if (channels[i] == NULL) {
1.25 markus 280: /* Found a free slot. */
1.209 avsm 281: found = (int)i;
1.25 markus 282: break;
283: }
1.209 avsm 284: if (found < 0) {
1.27 markus 285: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 286: found = channels_alloc;
1.179 markus 287: if (channels_alloc > 10000)
288: fatal("channel_new: internal error: channels_alloc %d "
289: "too big.", channels_alloc);
1.243 djm 290: channels = xrealloc(channels, channels_alloc + 10,
291: sizeof(Channel *));
1.195 markus 292: channels_alloc += 10;
1.70 markus 293: debug2("channel: expanding %d", channels_alloc);
1.25 markus 294: for (i = found; i < channels_alloc; i++)
1.113 markus 295: channels[i] = NULL;
1.25 markus 296: }
1.113 markus 297: /* Initialize and return new channel. */
1.242 djm 298: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 299: buffer_init(&c->input);
300: buffer_init(&c->output);
1.41 markus 301: buffer_init(&c->extended);
1.293 djm 302: c->path = NULL;
1.312 djm 303: c->listening_addr = NULL;
304: c->listening_port = 0;
1.159 markus 305: c->ostate = CHAN_OUTPUT_OPEN;
306: c->istate = CHAN_INPUT_OPEN;
307: c->flags = 0;
1.281 djm 308: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.317 djm 309: c->notbefore = 0;
1.25 markus 310: c->self = found;
311: c->type = type;
1.41 markus 312: c->ctype = ctype;
1.51 markus 313: c->local_window = window;
314: c->local_window_max = window;
315: c->local_consumed = 0;
316: c->local_maxpacket = maxpack;
1.25 markus 317: c->remote_id = -1;
1.190 markus 318: c->remote_name = xstrdup(remote_name);
1.41 markus 319: c->remote_window = 0;
320: c->remote_maxpacket = 0;
1.133 markus 321: c->force_drain = 0;
1.149 markus 322: c->single_connection = 0;
1.131 markus 323: c->detach_user = NULL;
1.225 djm 324: c->detach_close = 0;
1.275 djm 325: c->open_confirm = NULL;
326: c->open_confirm_ctx = NULL;
1.65 markus 327: c->input_filter = NULL;
1.231 reyk 328: c->output_filter = NULL;
1.280 djm 329: c->filter_ctx = NULL;
330: c->filter_cleanup = NULL;
1.302 djm 331: c->ctl_chan = -1;
332: c->mux_rcb = NULL;
333: c->mux_ctx = NULL;
1.304 djm 334: c->mux_pause = 0;
1.299 markus 335: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 336: TAILQ_INIT(&c->status_confirms);
1.25 markus 337: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 338: return c;
1.1 deraadt 339: }
1.52 markus 340:
1.132 markus 341: static int
342: channel_find_maxfd(void)
343: {
1.209 avsm 344: u_int i;
345: int max = 0;
1.132 markus 346: Channel *c;
347:
348: for (i = 0; i < channels_alloc; i++) {
349: c = channels[i];
350: if (c != NULL) {
351: max = MAX(max, c->rfd);
352: max = MAX(max, c->wfd);
353: max = MAX(max, c->efd);
354: }
355: }
356: return max;
357: }
358:
359: int
360: channel_close_fd(int *fdp)
361: {
362: int ret = 0, fd = *fdp;
363:
364: if (fd != -1) {
365: ret = close(fd);
366: *fdp = -1;
367: if (fd == channel_max_fd)
368: channel_max_fd = channel_find_maxfd();
369: }
370: return ret;
371: }
372:
1.52 markus 373: /* Close all channel fd/socket. */
1.127 itojun 374: static void
1.52 markus 375: channel_close_fds(Channel *c)
376: {
1.132 markus 377: channel_close_fd(&c->sock);
378: channel_close_fd(&c->rfd);
379: channel_close_fd(&c->wfd);
380: channel_close_fd(&c->efd);
1.121 markus 381: }
382:
383: /* Free the channel and close its fd/socket. */
384: void
385: channel_free(Channel *c)
386: {
387: char *s;
1.209 avsm 388: u_int i, n;
1.275 djm 389: struct channel_confirm *cc;
1.121 markus 390:
391: for (n = 0, i = 0; i < channels_alloc; i++)
392: if (channels[i])
393: n++;
1.209 avsm 394: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 395: c->remote_name ? c->remote_name : "???", n);
396:
397: s = channel_open_message();
1.194 markus 398: debug3("channel %d: status: %s", c->self, s);
1.321 ! djm 399: free(s);
1.121 markus 400:
401: if (c->sock != -1)
402: shutdown(c->sock, SHUT_RDWR);
403: channel_close_fds(c);
404: buffer_free(&c->input);
405: buffer_free(&c->output);
406: buffer_free(&c->extended);
1.321 ! djm 407: free(c->remote_name);
! 408: c->remote_name = NULL;
! 409: free(c->path);
! 410: c->path = NULL;
! 411: free(c->listening_addr);
! 412: c->listening_addr = NULL;
1.275 djm 413: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
414: if (cc->abandon_cb != NULL)
415: cc->abandon_cb(c, cc->ctx);
416: TAILQ_REMOVE(&c->status_confirms, cc, entry);
417: bzero(cc, sizeof(*cc));
1.321 ! djm 418: free(cc);
1.275 djm 419: }
1.280 djm 420: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
421: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 422: channels[c->self] = NULL;
1.321 ! djm 423: free(c);
1.121 markus 424: }
425:
426: void
1.126 markus 427: channel_free_all(void)
1.121 markus 428: {
1.209 avsm 429: u_int i;
1.121 markus 430:
1.126 markus 431: for (i = 0; i < channels_alloc; i++)
432: if (channels[i] != NULL)
433: channel_free(channels[i]);
1.131 markus 434: }
435:
1.121 markus 436: /*
437: * Closes the sockets/fds of all channels. This is used to close extra file
438: * descriptors after a fork.
439: */
440: void
1.142 itojun 441: channel_close_all(void)
1.121 markus 442: {
1.209 avsm 443: u_int i;
1.121 markus 444:
445: for (i = 0; i < channels_alloc; i++)
446: if (channels[i] != NULL)
447: channel_close_fds(channels[i]);
448: }
449:
450: /*
1.131 markus 451: * Stop listening to channels.
452: */
453: void
454: channel_stop_listening(void)
455: {
1.209 avsm 456: u_int i;
1.131 markus 457: Channel *c;
458:
459: for (i = 0; i < channels_alloc; i++) {
460: c = channels[i];
461: if (c != NULL) {
462: switch (c->type) {
463: case SSH_CHANNEL_AUTH_SOCKET:
464: case SSH_CHANNEL_PORT_LISTENER:
465: case SSH_CHANNEL_RPORT_LISTENER:
466: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 467: channel_close_fd(&c->sock);
1.131 markus 468: channel_free(c);
469: break;
470: }
471: }
472: }
473: }
474:
475: /*
1.121 markus 476: * Returns true if no channel has too much buffered data, and false if one or
477: * more channel is overfull.
478: */
479: int
1.142 itojun 480: channel_not_very_much_buffered_data(void)
1.121 markus 481: {
482: u_int i;
483: Channel *c;
484:
485: for (i = 0; i < channels_alloc; i++) {
486: c = channels[i];
487: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 488: #if 0
489: if (!compat20 &&
490: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 491: debug2("channel %d: big input buffer %d",
1.121 markus 492: c->self, buffer_len(&c->input));
493: return 0;
494: }
1.136 markus 495: #endif
1.121 markus 496: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 497: debug2("channel %d: big output buffer %u > %u",
1.136 markus 498: c->self, buffer_len(&c->output),
499: packet_get_maxsize());
1.121 markus 500: return 0;
501: }
502: }
503: }
504: return 1;
505: }
506:
507: /* Returns true if any channel is still open. */
508: int
1.142 itojun 509: channel_still_open(void)
1.121 markus 510: {
1.209 avsm 511: u_int i;
1.121 markus 512: Channel *c;
513:
514: for (i = 0; i < channels_alloc; i++) {
515: c = channels[i];
516: if (c == NULL)
517: continue;
518: switch (c->type) {
519: case SSH_CHANNEL_X11_LISTENER:
520: case SSH_CHANNEL_PORT_LISTENER:
521: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 522: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 523: case SSH_CHANNEL_CLOSED:
524: case SSH_CHANNEL_AUTH_SOCKET:
525: case SSH_CHANNEL_DYNAMIC:
526: case SSH_CHANNEL_CONNECTING:
527: case SSH_CHANNEL_ZOMBIE:
528: continue;
529: case SSH_CHANNEL_LARVAL:
530: if (!compat20)
531: fatal("cannot happen: SSH_CHANNEL_LARVAL");
532: continue;
533: case SSH_CHANNEL_OPENING:
534: case SSH_CHANNEL_OPEN:
535: case SSH_CHANNEL_X11_OPEN:
1.302 djm 536: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 537: return 1;
538: case SSH_CHANNEL_INPUT_DRAINING:
539: case SSH_CHANNEL_OUTPUT_DRAINING:
540: if (!compat13)
541: fatal("cannot happen: OUT_DRAIN");
542: return 1;
543: default:
544: fatal("channel_still_open: bad channel type %d", c->type);
545: /* NOTREACHED */
546: }
547: }
548: return 0;
549: }
550:
551: /* Returns the id of an open channel suitable for keepaliving */
552: int
1.142 itojun 553: channel_find_open(void)
1.121 markus 554: {
1.209 avsm 555: u_int i;
1.121 markus 556: Channel *c;
557:
558: for (i = 0; i < channels_alloc; i++) {
559: c = channels[i];
1.206 djm 560: if (c == NULL || c->remote_id < 0)
1.121 markus 561: continue;
562: switch (c->type) {
563: case SSH_CHANNEL_CLOSED:
564: case SSH_CHANNEL_DYNAMIC:
565: case SSH_CHANNEL_X11_LISTENER:
566: case SSH_CHANNEL_PORT_LISTENER:
567: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 568: case SSH_CHANNEL_MUX_LISTENER:
569: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 570: case SSH_CHANNEL_OPENING:
571: case SSH_CHANNEL_CONNECTING:
572: case SSH_CHANNEL_ZOMBIE:
573: continue;
574: case SSH_CHANNEL_LARVAL:
575: case SSH_CHANNEL_AUTH_SOCKET:
576: case SSH_CHANNEL_OPEN:
577: case SSH_CHANNEL_X11_OPEN:
578: return i;
579: case SSH_CHANNEL_INPUT_DRAINING:
580: case SSH_CHANNEL_OUTPUT_DRAINING:
581: if (!compat13)
582: fatal("cannot happen: OUT_DRAIN");
583: return i;
584: default:
585: fatal("channel_find_open: bad channel type %d", c->type);
586: /* NOTREACHED */
587: }
588: }
589: return -1;
590: }
591:
592:
593: /*
594: * Returns a message describing the currently open forwarded connections,
595: * suitable for sending to the client. The message contains crlf pairs for
596: * newlines.
597: */
598: char *
1.142 itojun 599: channel_open_message(void)
1.121 markus 600: {
601: Buffer buffer;
602: Channel *c;
603: char buf[1024], *cp;
1.209 avsm 604: u_int i;
1.121 markus 605:
606: buffer_init(&buffer);
607: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
608: buffer_append(&buffer, buf, strlen(buf));
609: for (i = 0; i < channels_alloc; i++) {
610: c = channels[i];
611: if (c == NULL)
612: continue;
613: switch (c->type) {
614: case SSH_CHANNEL_X11_LISTENER:
615: case SSH_CHANNEL_PORT_LISTENER:
616: case SSH_CHANNEL_RPORT_LISTENER:
617: case SSH_CHANNEL_CLOSED:
618: case SSH_CHANNEL_AUTH_SOCKET:
619: case SSH_CHANNEL_ZOMBIE:
1.302 djm 620: case SSH_CHANNEL_MUX_CLIENT:
621: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 622: continue;
623: case SSH_CHANNEL_LARVAL:
624: case SSH_CHANNEL_OPENING:
625: case SSH_CHANNEL_CONNECTING:
626: case SSH_CHANNEL_DYNAMIC:
627: case SSH_CHANNEL_OPEN:
628: case SSH_CHANNEL_X11_OPEN:
629: case SSH_CHANNEL_INPUT_DRAINING:
630: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 631: snprintf(buf, sizeof buf,
1.302 djm 632: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
1.121 markus 633: c->self, c->remote_name,
634: c->type, c->remote_id,
635: c->istate, buffer_len(&c->input),
636: c->ostate, buffer_len(&c->output),
1.302 djm 637: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 638: buffer_append(&buffer, buf, strlen(buf));
639: continue;
640: default:
641: fatal("channel_open_message: bad channel type %d", c->type);
642: /* NOTREACHED */
643: }
644: }
645: buffer_append(&buffer, "\0", 1);
646: cp = xstrdup(buffer_ptr(&buffer));
647: buffer_free(&buffer);
648: return cp;
649: }
650:
651: void
652: channel_send_open(int id)
653: {
654: Channel *c = channel_lookup(id);
1.180 deraadt 655:
1.121 markus 656: if (c == NULL) {
1.188 itojun 657: logit("channel_send_open: %d: bad id", id);
1.121 markus 658: return;
659: }
1.184 markus 660: debug2("channel %d: send open", id);
1.121 markus 661: packet_start(SSH2_MSG_CHANNEL_OPEN);
662: packet_put_cstring(c->ctype);
663: packet_put_int(c->self);
664: packet_put_int(c->local_window);
665: packet_put_int(c->local_maxpacket);
666: packet_send();
667: }
668:
669: void
1.184 markus 670: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 671: {
1.184 markus 672: Channel *c = channel_lookup(id);
1.180 deraadt 673:
1.121 markus 674: if (c == NULL) {
1.188 itojun 675: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 676: return;
677: }
1.204 djm 678: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 679: packet_start(SSH2_MSG_CHANNEL_REQUEST);
680: packet_put_int(c->remote_id);
681: packet_put_cstring(service);
682: packet_put_char(wantconfirm);
683: }
1.241 deraadt 684:
1.121 markus 685: void
1.275 djm 686: channel_register_status_confirm(int id, channel_confirm_cb *cb,
687: channel_confirm_abandon_cb *abandon_cb, void *ctx)
688: {
689: struct channel_confirm *cc;
690: Channel *c;
691:
692: if ((c = channel_lookup(id)) == NULL)
693: fatal("channel_register_expect: %d: bad id", id);
694:
695: cc = xmalloc(sizeof(*cc));
696: cc->cb = cb;
697: cc->abandon_cb = abandon_cb;
698: cc->ctx = ctx;
699: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
700: }
701:
702: void
1.304 djm 703: channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
1.121 markus 704: {
705: Channel *c = channel_lookup(id);
1.180 deraadt 706:
1.121 markus 707: if (c == NULL) {
1.287 stevesk 708: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 709: return;
710: }
1.275 djm 711: c->open_confirm = fn;
712: c->open_confirm_ctx = ctx;
1.121 markus 713: }
1.241 deraadt 714:
1.121 markus 715: void
1.225 djm 716: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 717: {
1.229 markus 718: Channel *c = channel_by_id(id);
1.180 deraadt 719:
1.121 markus 720: if (c == NULL) {
1.188 itojun 721: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 722: return;
723: }
1.131 markus 724: c->detach_user = fn;
1.225 djm 725: c->detach_close = do_close;
1.121 markus 726: }
1.241 deraadt 727:
1.121 markus 728: void
729: channel_cancel_cleanup(int id)
730: {
1.229 markus 731: Channel *c = channel_by_id(id);
1.180 deraadt 732:
1.121 markus 733: if (c == NULL) {
1.188 itojun 734: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 735: return;
1.52 markus 736: }
1.131 markus 737: c->detach_user = NULL;
1.225 djm 738: c->detach_close = 0;
1.121 markus 739: }
1.241 deraadt 740:
1.121 markus 741: void
1.231 reyk 742: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 743: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 744: {
745: Channel *c = channel_lookup(id);
1.180 deraadt 746:
1.121 markus 747: if (c == NULL) {
1.188 itojun 748: logit("channel_register_filter: %d: bad id", id);
1.121 markus 749: return;
1.52 markus 750: }
1.231 reyk 751: c->input_filter = ifn;
752: c->output_filter = ofn;
1.279 djm 753: c->filter_ctx = ctx;
1.280 djm 754: c->filter_cleanup = cfn;
1.52 markus 755: }
756:
1.49 markus 757: void
1.121 markus 758: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 759: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 760: {
1.121 markus 761: Channel *c = channel_lookup(id);
1.180 deraadt 762:
1.121 markus 763: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
764: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 765: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 766: c->type = SSH_CHANNEL_OPEN;
1.168 markus 767: c->local_window = c->local_window_max = window_max;
1.121 markus 768: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
769: packet_put_int(c->remote_id);
770: packet_put_int(c->local_window);
771: packet_send();
1.1 deraadt 772: }
773:
1.27 markus 774: /*
1.41 markus 775: * 'channel_pre*' are called just before select() to add any bits relevant to
776: * channels in the select bitmasks.
777: */
778: /*
779: * 'channel_post*': perform any appropriate operations for channels which
780: * have events pending.
1.27 markus 781: */
1.237 deraadt 782: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 783: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
784: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
785:
1.259 stevesk 786: /* ARGSUSED */
1.127 itojun 787: static void
1.237 deraadt 788: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 789: {
790: FD_SET(c->sock, readset);
791: }
792:
1.259 stevesk 793: /* ARGSUSED */
1.127 itojun 794: static void
1.237 deraadt 795: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 796: {
797: debug3("channel %d: waiting for connection", c->self);
798: FD_SET(c->sock, writeset);
799: }
800:
1.127 itojun 801: static void
1.237 deraadt 802: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 803: {
804: if (buffer_len(&c->input) < packet_get_maxsize())
805: FD_SET(c->sock, readset);
806: if (buffer_len(&c->output) > 0)
807: FD_SET(c->sock, writeset);
808: }
1.1 deraadt 809:
1.127 itojun 810: static void
1.237 deraadt 811: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 812: {
1.157 markus 813: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 814:
1.44 markus 815: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 816: limit > 0 &&
1.250 djm 817: buffer_len(&c->input) < limit &&
818: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 819: FD_SET(c->rfd, readset);
820: if (c->ostate == CHAN_OUTPUT_OPEN ||
821: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
822: if (buffer_len(&c->output) > 0) {
823: FD_SET(c->wfd, writeset);
824: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 825: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 826: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
827: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 828: else
829: chan_obuf_empty(c);
1.44 markus 830: }
831: }
832: /** XXX check close conditions, too */
1.277 markus 833: if (compat20 && c->efd != -1 &&
834: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 835: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
836: buffer_len(&c->extended) > 0)
837: FD_SET(c->efd, writeset);
1.306 djm 838: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
839: (c->extended_usage == CHAN_EXTENDED_READ ||
840: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 841: buffer_len(&c->extended) < c->remote_window)
842: FD_SET(c->efd, readset);
843: }
1.204 djm 844: /* XXX: What about efd? races? */
1.44 markus 845: }
846:
1.259 stevesk 847: /* ARGSUSED */
1.127 itojun 848: static void
1.237 deraadt 849: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 850: {
851: if (buffer_len(&c->input) == 0) {
852: packet_start(SSH_MSG_CHANNEL_CLOSE);
853: packet_put_int(c->remote_id);
854: packet_send();
855: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 856: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 857: }
858: }
859:
1.259 stevesk 860: /* ARGSUSED */
1.127 itojun 861: static void
1.237 deraadt 862: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 863: {
864: if (buffer_len(&c->output) == 0)
1.113 markus 865: chan_mark_dead(c);
1.49 markus 866: else
1.41 markus 867: FD_SET(c->sock, writeset);
868: }
869:
870: /*
871: * This is a special state for X11 authentication spoofing. An opened X11
872: * connection (when authentication spoofing is being done) remains in this
873: * state until the first packet has been completely read. The authentication
874: * data in that packet is then substituted by the real data if it matches the
875: * fake data, and the channel is put into normal mode.
1.51 markus 876: * XXX All this happens at the client side.
1.121 markus 877: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 878: */
1.127 itojun 879: static int
1.121 markus 880: x11_open_helper(Buffer *b)
1.1 deraadt 881: {
1.77 markus 882: u_char *ucp;
883: u_int proto_len, data_len;
1.25 markus 884:
1.41 markus 885: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 886: if (buffer_len(b) < 12)
1.41 markus 887: return 0;
888:
889: /* Parse the lengths of variable-length fields. */
1.155 stevesk 890: ucp = buffer_ptr(b);
1.41 markus 891: if (ucp[0] == 0x42) { /* Byte order MSB first. */
892: proto_len = 256 * ucp[6] + ucp[7];
893: data_len = 256 * ucp[8] + ucp[9];
894: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
895: proto_len = ucp[6] + 256 * ucp[7];
896: data_len = ucp[8] + 256 * ucp[9];
897: } else {
1.194 markus 898: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 899: ucp[0]);
1.41 markus 900: return -1;
901: }
902:
903: /* Check if the whole packet is in buffer. */
1.121 markus 904: if (buffer_len(b) <
1.41 markus 905: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
906: return 0;
907:
908: /* Check if authentication protocol matches. */
909: if (proto_len != strlen(x11_saved_proto) ||
910: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 911: debug2("X11 connection uses different authentication protocol.");
1.41 markus 912: return -1;
913: }
914: /* Check if authentication data matches our fake data. */
915: if (data_len != x11_fake_data_len ||
1.308 djm 916: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.41 markus 917: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 918: debug2("X11 auth data does not match fake data.");
1.41 markus 919: return -1;
920: }
921: /* Check fake data length */
922: if (x11_fake_data_len != x11_saved_data_len) {
923: error("X11 fake_data_len %d != saved_data_len %d",
924: x11_fake_data_len, x11_saved_data_len);
925: return -1;
926: }
927: /*
928: * Received authentication protocol and data match
929: * our fake data. Substitute the fake data with real
930: * data.
931: */
932: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
933: x11_saved_data, x11_saved_data_len);
934: return 1;
935: }
936:
1.127 itojun 937: static void
1.237 deraadt 938: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 939: {
1.121 markus 940: int ret = x11_open_helper(&c->output);
1.180 deraadt 941:
1.41 markus 942: if (ret == 1) {
943: /* Start normal processing for the channel. */
944: c->type = SSH_CHANNEL_OPEN;
1.47 markus 945: channel_pre_open_13(c, readset, writeset);
1.41 markus 946: } else if (ret == -1) {
947: /*
948: * We have received an X11 connection that has bad
949: * authentication information.
950: */
1.188 itojun 951: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 952: buffer_clear(&c->input);
953: buffer_clear(&c->output);
1.132 markus 954: channel_close_fd(&c->sock);
1.41 markus 955: c->sock = -1;
956: c->type = SSH_CHANNEL_CLOSED;
957: packet_start(SSH_MSG_CHANNEL_CLOSE);
958: packet_put_int(c->remote_id);
959: packet_send();
960: }
961: }
1.25 markus 962:
1.127 itojun 963: static void
1.237 deraadt 964: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 965: {
1.121 markus 966: int ret = x11_open_helper(&c->output);
1.133 markus 967:
968: /* c->force_drain = 1; */
969:
1.41 markus 970: if (ret == 1) {
971: c->type = SSH_CHANNEL_OPEN;
1.157 markus 972: channel_pre_open(c, readset, writeset);
1.41 markus 973: } else if (ret == -1) {
1.188 itojun 974: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 975: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 976: chan_read_failed(c);
977: buffer_clear(&c->input);
978: chan_ibuf_empty(c);
979: buffer_clear(&c->output);
980: /* for proto v1, the peer will send an IEOF */
981: if (compat20)
982: chan_write_failed(c);
983: else
984: c->type = SSH_CHANNEL_OPEN;
1.194 markus 985: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 986: }
987: }
1.25 markus 988:
1.302 djm 989: static void
990: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
991: {
1.304 djm 992: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 993: buffer_check_alloc(&c->input, CHAN_RBUF))
994: FD_SET(c->rfd, readset);
995: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
996: /* clear buffer immediately (discard any partial packet) */
997: buffer_clear(&c->input);
998: chan_ibuf_empty(c);
999: /* Start output drain. XXX just kill chan? */
1000: chan_rcvd_oclose(c);
1001: }
1002: if (c->ostate == CHAN_OUTPUT_OPEN ||
1003: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1004: if (buffer_len(&c->output) > 0)
1005: FD_SET(c->wfd, writeset);
1006: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1007: chan_obuf_empty(c);
1008: }
1009: }
1010:
1.104 markus 1011: /* try to decode a socks4 header */
1.259 stevesk 1012: /* ARGSUSED */
1.127 itojun 1013: static int
1.237 deraadt 1014: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1015: {
1.181 markus 1016: char *p, *host;
1.292 djm 1017: u_int len, have, i, found, need;
1.148 deraadt 1018: char username[256];
1.103 markus 1019: struct {
1020: u_int8_t version;
1021: u_int8_t command;
1022: u_int16_t dest_port;
1.104 markus 1023: struct in_addr dest_addr;
1.103 markus 1024: } s4_req, s4_rsp;
1025:
1.104 markus 1026: debug2("channel %d: decode socks4", c->self);
1.109 markus 1027:
1028: have = buffer_len(&c->input);
1029: len = sizeof(s4_req);
1030: if (have < len)
1031: return 0;
1032: p = buffer_ptr(&c->input);
1.292 djm 1033:
1034: need = 1;
1035: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1036: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1037: debug2("channel %d: socks4a request", c->self);
1038: /* ... and needs an extra string (the hostname) */
1039: need = 2;
1040: }
1041: /* Check for terminating NUL on the string(s) */
1.109 markus 1042: for (found = 0, i = len; i < have; i++) {
1043: if (p[i] == '\0') {
1.292 djm 1044: found++;
1045: if (found == need)
1046: break;
1.109 markus 1047: }
1048: if (i > 1024) {
1049: /* the peer is probably sending garbage */
1050: debug("channel %d: decode socks4: too long",
1051: c->self);
1052: return -1;
1053: }
1054: }
1.292 djm 1055: if (found < need)
1.109 markus 1056: return 0;
1.103 markus 1057: buffer_get(&c->input, (char *)&s4_req.version, 1);
1058: buffer_get(&c->input, (char *)&s4_req.command, 1);
1059: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1060: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1061: have = buffer_len(&c->input);
1.103 markus 1062: p = buffer_ptr(&c->input);
1063: len = strlen(p);
1.106 markus 1064: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1065: len++; /* trailing '\0' */
1.103 markus 1066: if (len > have)
1.104 markus 1067: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1068: c->self, len, have);
1069: strlcpy(username, p, sizeof(username));
1070: buffer_consume(&c->input, len);
1071:
1.321 ! djm 1072: free(c->path);
! 1073: c->path = NULL;
1.292 djm 1074: if (need == 1) { /* SOCKS4: one string */
1075: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1076: c->path = xstrdup(host);
1.292 djm 1077: } else { /* SOCKS4A: two strings */
1078: have = buffer_len(&c->input);
1079: p = buffer_ptr(&c->input);
1080: len = strlen(p);
1081: debug2("channel %d: decode socks4a: host %s/%d",
1082: c->self, p, len);
1083: len++; /* trailing '\0' */
1084: if (len > have)
1085: fatal("channel %d: decode socks4a: len %d > have %d",
1086: c->self, len, have);
1.293 djm 1087: if (len > NI_MAXHOST) {
1.292 djm 1088: error("channel %d: hostname \"%.100s\" too long",
1089: c->self, p);
1090: return -1;
1091: }
1.293 djm 1092: c->path = xstrdup(p);
1.292 djm 1093: buffer_consume(&c->input, len);
1094: }
1.103 markus 1095: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1096:
1.194 markus 1097: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1098: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1099:
1.104 markus 1100: if (s4_req.command != 1) {
1.292 djm 1101: debug("channel %d: cannot handle: %s cn %d",
1102: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1103: return -1;
1.103 markus 1104: }
1.104 markus 1105: s4_rsp.version = 0; /* vn: 0 for reply */
1106: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1107: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1108: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1109: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1110: return 1;
1111: }
1112:
1.193 markus 1113: /* try to decode a socks5 header */
1114: #define SSH_SOCKS5_AUTHDONE 0x1000
1115: #define SSH_SOCKS5_NOAUTH 0x00
1116: #define SSH_SOCKS5_IPV4 0x01
1117: #define SSH_SOCKS5_DOMAIN 0x03
1118: #define SSH_SOCKS5_IPV6 0x04
1119: #define SSH_SOCKS5_CONNECT 0x01
1120: #define SSH_SOCKS5_SUCCESS 0x00
1121:
1.259 stevesk 1122: /* ARGSUSED */
1.193 markus 1123: static int
1.237 deraadt 1124: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1125: {
1126: struct {
1127: u_int8_t version;
1128: u_int8_t command;
1129: u_int8_t reserved;
1130: u_int8_t atyp;
1131: } s5_req, s5_rsp;
1132: u_int16_t dest_port;
1.293 djm 1133: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1134: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1135:
1136: debug2("channel %d: decode socks5", c->self);
1137: p = buffer_ptr(&c->input);
1138: if (p[0] != 0x05)
1139: return -1;
1140: have = buffer_len(&c->input);
1141: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1142: /* format: ver | nmethods | methods */
1.198 djm 1143: if (have < 2)
1.193 markus 1144: return 0;
1145: nmethods = p[1];
1146: if (have < nmethods + 2)
1147: return 0;
1148: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1149: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1150: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1151: found = 1;
1152: break;
1153: }
1154: }
1155: if (!found) {
1156: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1157: c->self);
1158: return -1;
1159: }
1160: buffer_consume(&c->input, nmethods + 2);
1161: buffer_put_char(&c->output, 0x05); /* version */
1162: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1163: FD_SET(c->sock, writeset);
1164: c->flags |= SSH_SOCKS5_AUTHDONE;
1165: debug2("channel %d: socks5 auth done", c->self);
1166: return 0; /* need more */
1167: }
1168: debug2("channel %d: socks5 post auth", c->self);
1169: if (have < sizeof(s5_req)+1)
1170: return 0; /* need more */
1.247 deraadt 1171: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1172: if (s5_req.version != 0x05 ||
1173: s5_req.command != SSH_SOCKS5_CONNECT ||
1174: s5_req.reserved != 0x00) {
1.194 markus 1175: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1176: return -1;
1177: }
1.213 deraadt 1178: switch (s5_req.atyp){
1.193 markus 1179: case SSH_SOCKS5_IPV4:
1180: addrlen = 4;
1181: af = AF_INET;
1182: break;
1183: case SSH_SOCKS5_DOMAIN:
1184: addrlen = p[sizeof(s5_req)];
1185: af = -1;
1186: break;
1187: case SSH_SOCKS5_IPV6:
1188: addrlen = 16;
1189: af = AF_INET6;
1190: break;
1191: default:
1.194 markus 1192: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1193: return -1;
1194: }
1.252 djm 1195: need = sizeof(s5_req) + addrlen + 2;
1196: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1197: need++;
1198: if (have < need)
1.193 markus 1199: return 0;
1200: buffer_consume(&c->input, sizeof(s5_req));
1201: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1202: buffer_consume(&c->input, 1); /* host string length */
1203: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1204: buffer_get(&c->input, (char *)&dest_port, 2);
1205: dest_addr[addrlen] = '\0';
1.321 ! djm 1206: free(c->path);
! 1207: c->path = NULL;
1.293 djm 1208: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1209: if (addrlen >= NI_MAXHOST) {
1.293 djm 1210: error("channel %d: dynamic request: socks5 hostname "
1211: "\"%.100s\" too long", c->self, dest_addr);
1212: return -1;
1213: }
1214: c->path = xstrdup(dest_addr);
1215: } else {
1216: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1217: return -1;
1218: c->path = xstrdup(ntop);
1219: }
1.193 markus 1220: c->host_port = ntohs(dest_port);
1.198 djm 1221:
1.194 markus 1222: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1223: c->self, c->path, c->host_port, s5_req.command);
1224:
1225: s5_rsp.version = 0x05;
1226: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1227: s5_rsp.reserved = 0; /* ignored */
1228: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1229: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1230: dest_port = 0; /* ignored */
1231:
1.246 deraadt 1232: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1233: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1234: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1235: return 1;
1.301 dtucker 1236: }
1237:
1238: Channel *
1.302 djm 1239: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1240: int in, int out)
1.301 dtucker 1241: {
1242: Channel *c;
1243:
1244: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1245: port_to_connect);
1246:
1247: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1248: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1249: 0, "stdio-forward", /*nonblock*/0);
1250:
1251: c->path = xstrdup(host_to_connect);
1252: c->host_port = port_to_connect;
1253: c->listening_port = 0;
1254: c->force_drain = 1;
1255:
1256: channel_register_fds(c, in, out, -1, 0, 1, 0);
1257: port_open_helper(c, "direct-tcpip");
1258:
1259: return c;
1.193 markus 1260: }
1261:
1.104 markus 1262: /* dynamic port forwarding */
1.127 itojun 1263: static void
1.237 deraadt 1264: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1265: {
1266: u_char *p;
1.217 djm 1267: u_int have;
1268: int ret;
1.103 markus 1269:
1.104 markus 1270: have = buffer_len(&c->input);
1271: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1272: /* buffer_dump(&c->input); */
1.104 markus 1273: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1274: if (have < 3) {
1.104 markus 1275: /* need more */
1276: FD_SET(c->sock, readset);
1277: return;
1278: }
1279: /* try to guess the protocol */
1280: p = buffer_ptr(&c->input);
1281: switch (p[0]) {
1282: case 0x04:
1283: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1284: break;
1285: case 0x05:
1286: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1287: break;
1288: default:
1289: ret = -1;
1290: break;
1291: }
1292: if (ret < 0) {
1.113 markus 1293: chan_mark_dead(c);
1.104 markus 1294: } else if (ret == 0) {
1295: debug2("channel %d: pre_dynamic: need more", c->self);
1296: /* need more */
1297: FD_SET(c->sock, readset);
1298: } else {
1299: /* switch to the next state */
1300: c->type = SSH_CHANNEL_OPENING;
1301: port_open_helper(c, "direct-tcpip");
1302: }
1.103 markus 1303: }
1304:
1.41 markus 1305: /* This is our fake X11 server socket. */
1.259 stevesk 1306: /* ARGSUSED */
1.127 itojun 1307: static void
1.237 deraadt 1308: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1309: {
1.113 markus 1310: Channel *nc;
1.285 djm 1311: struct sockaddr_storage addr;
1.320 markus 1312: int newsock, oerrno;
1.41 markus 1313: socklen_t addrlen;
1.85 markus 1314: char buf[16384], *remote_ipaddr;
1.51 markus 1315: int remote_port;
1.25 markus 1316:
1.41 markus 1317: if (FD_ISSET(c->sock, readset)) {
1318: debug("X11 connection requested.");
1319: addrlen = sizeof(addr);
1.285 djm 1320: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1321: if (c->single_connection) {
1.320 markus 1322: oerrno = errno;
1.194 markus 1323: debug2("single_connection: closing X11 listener.");
1.149 markus 1324: channel_close_fd(&c->sock);
1325: chan_mark_dead(c);
1.320 markus 1326: errno = oerrno;
1.149 markus 1327: }
1.41 markus 1328: if (newsock < 0) {
1.320 markus 1329: if (errno != EINTR && errno != EWOULDBLOCK &&
1330: errno != ECONNABORTED)
1331: error("accept: %.100s", strerror(errno));
1.317 djm 1332: if (errno == EMFILE || errno == ENFILE)
1333: c->notbefore = time(NULL) + 1;
1.41 markus 1334: return;
1335: }
1.162 stevesk 1336: set_nodelay(newsock);
1.85 markus 1337: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1338: remote_port = get_peer_port(newsock);
1.41 markus 1339: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1340: remote_ipaddr, remote_port);
1.51 markus 1341:
1.113 markus 1342: nc = channel_new("accepted x11 socket",
1.51 markus 1343: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1344: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1345: if (compat20) {
1346: packet_start(SSH2_MSG_CHANNEL_OPEN);
1347: packet_put_cstring("x11");
1.113 markus 1348: packet_put_int(nc->self);
1.149 markus 1349: packet_put_int(nc->local_window_max);
1350: packet_put_int(nc->local_maxpacket);
1.85 markus 1351: /* originator ipaddr and port */
1352: packet_put_cstring(remote_ipaddr);
1.57 markus 1353: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1354: debug2("ssh2 x11 bug compat mode");
1.57 markus 1355: } else {
1356: packet_put_int(remote_port);
1357: }
1.51 markus 1358: packet_send();
1359: } else {
1360: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1361: packet_put_int(nc->self);
1.121 markus 1362: if (packet_get_protocol_flags() &
1363: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1364: packet_put_cstring(buf);
1.51 markus 1365: packet_send();
1366: }
1.321 ! djm 1367: free(remote_ipaddr);
1.41 markus 1368: }
1369: }
1.25 markus 1370:
1.127 itojun 1371: static void
1.103 markus 1372: port_open_helper(Channel *c, char *rtype)
1373: {
1374: int direct;
1375: char buf[1024];
1376: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1377: int remote_port = get_peer_port(c->sock);
1.303 djm 1378:
1379: if (remote_port == -1) {
1380: /* Fake addr/port to appease peers that validate it (Tectia) */
1.321 ! djm 1381: free(remote_ipaddr);
1.303 djm 1382: remote_ipaddr = xstrdup("127.0.0.1");
1383: remote_port = 65535;
1384: }
1.103 markus 1385:
1386: direct = (strcmp(rtype, "direct-tcpip") == 0);
1387:
1388: snprintf(buf, sizeof buf,
1389: "%s: listening port %d for %.100s port %d, "
1390: "connect from %.200s port %d",
1391: rtype, c->listening_port, c->path, c->host_port,
1392: remote_ipaddr, remote_port);
1393:
1.321 ! djm 1394: free(c->remote_name);
1.103 markus 1395: c->remote_name = xstrdup(buf);
1396:
1397: if (compat20) {
1398: packet_start(SSH2_MSG_CHANNEL_OPEN);
1399: packet_put_cstring(rtype);
1400: packet_put_int(c->self);
1401: packet_put_int(c->local_window_max);
1402: packet_put_int(c->local_maxpacket);
1403: if (direct) {
1404: /* target host, port */
1405: packet_put_cstring(c->path);
1406: packet_put_int(c->host_port);
1407: } else {
1408: /* listen address, port */
1409: packet_put_cstring(c->path);
1410: packet_put_int(c->listening_port);
1411: }
1412: /* originator host and port */
1413: packet_put_cstring(remote_ipaddr);
1.216 markus 1414: packet_put_int((u_int)remote_port);
1.103 markus 1415: packet_send();
1416: } else {
1417: packet_start(SSH_MSG_PORT_OPEN);
1418: packet_put_int(c->self);
1419: packet_put_cstring(c->path);
1420: packet_put_int(c->host_port);
1.121 markus 1421: if (packet_get_protocol_flags() &
1422: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1423: packet_put_cstring(c->remote_name);
1424: packet_send();
1425: }
1.321 ! djm 1426: free(remote_ipaddr);
1.103 markus 1427: }
1428:
1.226 djm 1429: static void
1430: channel_set_reuseaddr(int fd)
1431: {
1432: int on = 1;
1433:
1434: /*
1435: * Set socket options.
1436: * Allow local port reuse in TIME_WAIT.
1437: */
1438: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1439: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1440: }
1441:
1.41 markus 1442: /*
1443: * This socket is listening for connections to a forwarded TCP/IP port.
1444: */
1.259 stevesk 1445: /* ARGSUSED */
1.127 itojun 1446: static void
1.237 deraadt 1447: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1448: {
1.103 markus 1449: Channel *nc;
1.285 djm 1450: struct sockaddr_storage addr;
1.113 markus 1451: int newsock, nextstate;
1.41 markus 1452: socklen_t addrlen;
1.103 markus 1453: char *rtype;
1.73 markus 1454:
1.41 markus 1455: if (FD_ISSET(c->sock, readset)) {
1456: debug("Connection to port %d forwarding "
1457: "to %.100s port %d requested.",
1458: c->listening_port, c->path, c->host_port);
1.103 markus 1459:
1.137 markus 1460: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1461: nextstate = SSH_CHANNEL_OPENING;
1462: rtype = "forwarded-tcpip";
1463: } else {
1464: if (c->host_port == 0) {
1465: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1466: rtype = "dynamic-tcpip";
1.137 markus 1467: } else {
1468: nextstate = SSH_CHANNEL_OPENING;
1469: rtype = "direct-tcpip";
1470: }
1471: }
1.103 markus 1472:
1.41 markus 1473: addrlen = sizeof(addr);
1.285 djm 1474: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1475: if (newsock < 0) {
1.320 markus 1476: if (errno != EINTR && errno != EWOULDBLOCK &&
1477: errno != ECONNABORTED)
1478: error("accept: %.100s", strerror(errno));
1.317 djm 1479: if (errno == EMFILE || errno == ENFILE)
1480: c->notbefore = time(NULL) + 1;
1.41 markus 1481: return;
1482: }
1.169 stevesk 1483: set_nodelay(newsock);
1.190 markus 1484: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1485: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1486: nc->listening_port = c->listening_port;
1487: nc->host_port = c->host_port;
1.293 djm 1488: if (c->path != NULL)
1489: nc->path = xstrdup(c->path);
1.103 markus 1490:
1.299 markus 1491: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1492: port_open_helper(nc, rtype);
1.41 markus 1493: }
1494: }
1.25 markus 1495:
1.41 markus 1496: /*
1497: * This is the authentication agent socket listening for connections from
1498: * clients.
1499: */
1.259 stevesk 1500: /* ARGSUSED */
1.127 itojun 1501: static void
1.237 deraadt 1502: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1503: {
1.113 markus 1504: Channel *nc;
1505: int newsock;
1.285 djm 1506: struct sockaddr_storage addr;
1.41 markus 1507: socklen_t addrlen;
1.25 markus 1508:
1.41 markus 1509: if (FD_ISSET(c->sock, readset)) {
1510: addrlen = sizeof(addr);
1.285 djm 1511: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1512: if (newsock < 0) {
1.317 djm 1513: error("accept from auth socket: %.100s",
1514: strerror(errno));
1515: if (errno == EMFILE || errno == ENFILE)
1516: c->notbefore = time(NULL) + 1;
1.41 markus 1517: return;
1518: }
1.113 markus 1519: nc = channel_new("accepted auth socket",
1.73 markus 1520: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1521: c->local_window_max, c->local_maxpacket,
1.190 markus 1522: 0, "accepted auth socket", 1);
1.73 markus 1523: if (compat20) {
1524: packet_start(SSH2_MSG_CHANNEL_OPEN);
1525: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1526: packet_put_int(nc->self);
1.73 markus 1527: packet_put_int(c->local_window_max);
1528: packet_put_int(c->local_maxpacket);
1529: } else {
1530: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1531: packet_put_int(nc->self);
1.73 markus 1532: }
1.41 markus 1533: packet_send();
1534: }
1535: }
1.25 markus 1536:
1.259 stevesk 1537: /* ARGSUSED */
1.127 itojun 1538: static void
1.237 deraadt 1539: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1540: {
1.276 djm 1541: int err = 0, sock;
1.129 stevesk 1542: socklen_t sz = sizeof(err);
1.114 markus 1543:
1.75 markus 1544: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1545: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1546: err = errno;
1547: error("getsockopt SO_ERROR failed");
1548: }
1549: if (err == 0) {
1.276 djm 1550: debug("channel %d: connected to %s port %d",
1551: c->self, c->connect_ctx.host, c->connect_ctx.port);
1552: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1553: c->type = SSH_CHANNEL_OPEN;
1554: if (compat20) {
1555: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1556: packet_put_int(c->remote_id);
1557: packet_put_int(c->self);
1558: packet_put_int(c->local_window);
1559: packet_put_int(c->local_maxpacket);
1560: } else {
1561: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1562: packet_put_int(c->remote_id);
1563: packet_put_int(c->self);
1564: }
1.75 markus 1565: } else {
1.276 djm 1566: debug("channel %d: connection failed: %s",
1.114 markus 1567: c->self, strerror(err));
1.276 djm 1568: /* Try next address, if any */
1569: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1570: close(c->sock);
1571: c->sock = c->rfd = c->wfd = sock;
1572: channel_max_fd = channel_find_maxfd();
1573: return;
1574: }
1575: /* Exhausted all addresses */
1576: error("connect_to %.100s port %d: failed.",
1577: c->connect_ctx.host, c->connect_ctx.port);
1578: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1579: if (compat20) {
1580: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1581: packet_put_int(c->remote_id);
1582: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1583: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1584: packet_put_cstring(strerror(err));
1585: packet_put_cstring("");
1586: }
1.75 markus 1587: } else {
1.114 markus 1588: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1589: packet_put_int(c->remote_id);
1.75 markus 1590: }
1.114 markus 1591: chan_mark_dead(c);
1.75 markus 1592: }
1.114 markus 1593: packet_send();
1.75 markus 1594: }
1595: }
1596:
1.259 stevesk 1597: /* ARGSUSED */
1.127 itojun 1598: static int
1.237 deraadt 1599: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1600: {
1.214 markus 1601: char buf[CHAN_RBUF];
1.41 markus 1602: int len;
1.25 markus 1603:
1.118 markus 1604: if (c->rfd != -1 &&
1.41 markus 1605: FD_ISSET(c->rfd, readset)) {
1606: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1607: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1608: return 1;
1.41 markus 1609: if (len <= 0) {
1.194 markus 1610: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1611: c->self, c->rfd, len);
1.104 markus 1612: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1613: debug2("channel %d: not open", c->self);
1.113 markus 1614: chan_mark_dead(c);
1.103 markus 1615: return -1;
1.104 markus 1616: } else if (compat13) {
1.158 markus 1617: buffer_clear(&c->output);
1.41 markus 1618: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1619: debug2("channel %d: input draining.", c->self);
1.25 markus 1620: } else {
1.41 markus 1621: chan_read_failed(c);
1.25 markus 1622: }
1.41 markus 1623: return -1;
1624: }
1.143 deraadt 1625: if (c->input_filter != NULL) {
1.66 markus 1626: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1627: debug2("channel %d: filter stops", c->self);
1.65 markus 1628: chan_read_failed(c);
1629: }
1.228 reyk 1630: } else if (c->datagram) {
1631: buffer_put_string(&c->input, buf, len);
1.65 markus 1632: } else {
1633: buffer_append(&c->input, buf, len);
1634: }
1.41 markus 1635: }
1636: return 1;
1637: }
1.241 deraadt 1638:
1.259 stevesk 1639: /* ARGSUSED */
1.127 itojun 1640: static int
1.237 deraadt 1641: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1642: {
1.95 markus 1643: struct termios tio;
1.231 reyk 1644: u_char *data = NULL, *buf;
1.309 djm 1645: u_int dlen, olen = 0;
1.41 markus 1646: int len;
1.25 markus 1647:
1.41 markus 1648: /* Send buffered output data to the socket. */
1.118 markus 1649: if (c->wfd != -1 &&
1.41 markus 1650: FD_ISSET(c->wfd, writeset) &&
1651: buffer_len(&c->output) > 0) {
1.309 djm 1652: olen = buffer_len(&c->output);
1.231 reyk 1653: if (c->output_filter != NULL) {
1654: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1655: debug2("channel %d: filter stops", c->self);
1.232 reyk 1656: if (c->type != SSH_CHANNEL_OPEN)
1657: chan_mark_dead(c);
1658: else
1659: chan_write_failed(c);
1660: return -1;
1.231 reyk 1661: }
1662: } else if (c->datagram) {
1663: buf = data = buffer_get_string(&c->output, &dlen);
1664: } else {
1665: buf = data = buffer_ptr(&c->output);
1666: dlen = buffer_len(&c->output);
1667: }
1668:
1.228 reyk 1669: if (c->datagram) {
1670: /* ignore truncated writes, datagrams might get lost */
1.231 reyk 1671: len = write(c->wfd, buf, dlen);
1.321 ! djm 1672: free(data);
1.228 reyk 1673: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1674: return 1;
1675: if (len <= 0) {
1676: if (c->type != SSH_CHANNEL_OPEN)
1677: chan_mark_dead(c);
1678: else
1679: chan_write_failed(c);
1680: return -1;
1681: }
1.309 djm 1682: goto out;
1.228 reyk 1683: }
1.231 reyk 1684:
1685: len = write(c->wfd, buf, dlen);
1.53 markus 1686: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1687: return 1;
1.41 markus 1688: if (len <= 0) {
1.104 markus 1689: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1690: debug2("channel %d: not open", c->self);
1.113 markus 1691: chan_mark_dead(c);
1.104 markus 1692: return -1;
1693: } else if (compat13) {
1.158 markus 1694: buffer_clear(&c->output);
1.194 markus 1695: debug2("channel %d: input draining.", c->self);
1.41 markus 1696: c->type = SSH_CHANNEL_INPUT_DRAINING;
1697: } else {
1698: chan_write_failed(c);
1699: }
1700: return -1;
1.91 markus 1701: }
1.231 reyk 1702: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1703: if (tcgetattr(c->wfd, &tio) == 0 &&
1704: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1705: /*
1706: * Simulate echo to reduce the impact of
1.96 markus 1707: * traffic analysis. We need to match the
1.95 markus 1708: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1709: * (4 byte channel id + buf)
1.91 markus 1710: */
1.95 markus 1711: packet_send_ignore(4 + len);
1.91 markus 1712: packet_send();
1713: }
1.25 markus 1714: }
1.41 markus 1715: buffer_consume(&c->output, len);
1.44 markus 1716: }
1.309 djm 1717: out:
1718: if (compat20 && olen > 0)
1719: c->local_consumed += olen - buffer_len(&c->output);
1.44 markus 1720: return 1;
1721: }
1.241 deraadt 1722:
1.127 itojun 1723: static int
1.237 deraadt 1724: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1725: {
1.214 markus 1726: char buf[CHAN_RBUF];
1.44 markus 1727: int len;
1728:
1.45 markus 1729: /** XXX handle drain efd, too */
1.44 markus 1730: if (c->efd != -1) {
1731: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1732: FD_ISSET(c->efd, writeset) &&
1733: buffer_len(&c->extended) > 0) {
1734: len = write(c->efd, buffer_ptr(&c->extended),
1735: buffer_len(&c->extended));
1.70 markus 1736: debug2("channel %d: written %d to efd %d",
1.44 markus 1737: c->self, len, c->efd);
1.93 markus 1738: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1739: return 1;
1740: if (len <= 0) {
1741: debug2("channel %d: closing write-efd %d",
1742: c->self, c->efd);
1.132 markus 1743: channel_close_fd(&c->efd);
1.93 markus 1744: } else {
1.44 markus 1745: buffer_consume(&c->extended, len);
1746: c->local_consumed += len;
1747: }
1.306 djm 1748: } else if (c->efd != -1 &&
1749: (c->extended_usage == CHAN_EXTENDED_READ ||
1750: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 1751: FD_ISSET(c->efd, readset)) {
1752: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1753: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1754: c->self, len, c->efd);
1.93 markus 1755: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1756: return 1;
1757: if (len <= 0) {
1758: debug2("channel %d: closing read-efd %d",
1.45 markus 1759: c->self, c->efd);
1.132 markus 1760: channel_close_fd(&c->efd);
1.93 markus 1761: } else {
1.306 djm 1762: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1763: debug3("channel %d: discard efd",
1764: c->self);
1765: } else
1766: buffer_append(&c->extended, buf, len);
1.93 markus 1767: }
1.44 markus 1768: }
1769: }
1770: return 1;
1771: }
1.241 deraadt 1772:
1.259 stevesk 1773: /* ARGSUSED */
1.127 itojun 1774: static int
1.93 markus 1775: channel_check_window(Channel *c)
1.44 markus 1776: {
1.104 markus 1777: if (c->type == SSH_CHANNEL_OPEN &&
1778: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1779: ((c->local_window_max - c->local_window >
1.269 markus 1780: c->local_maxpacket*3) ||
1781: c->local_window < c->local_window_max/2) &&
1.44 markus 1782: c->local_consumed > 0) {
1783: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1784: packet_put_int(c->remote_id);
1785: packet_put_int(c->local_consumed);
1786: packet_send();
1.70 markus 1787: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1788: c->self, c->local_window,
1789: c->local_consumed);
1790: c->local_window += c->local_consumed;
1791: c->local_consumed = 0;
1.1 deraadt 1792: }
1.41 markus 1793: return 1;
1.1 deraadt 1794: }
1795:
1.127 itojun 1796: static void
1.237 deraadt 1797: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1798: {
1799: channel_handle_rfd(c, readset, writeset);
1800: channel_handle_wfd(c, readset, writeset);
1.157 markus 1801: if (!compat20)
1.137 markus 1802: return;
1.44 markus 1803: channel_handle_efd(c, readset, writeset);
1.93 markus 1804: channel_check_window(c);
1.44 markus 1805: }
1806:
1.302 djm 1807: static u_int
1808: read_mux(Channel *c, u_int need)
1809: {
1810: char buf[CHAN_RBUF];
1811: int len;
1812: u_int rlen;
1813:
1814: if (buffer_len(&c->input) < need) {
1815: rlen = need - buffer_len(&c->input);
1816: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1817: if (len <= 0) {
1818: if (errno != EINTR && errno != EAGAIN) {
1819: debug2("channel %d: ctl read<=0 rfd %d len %d",
1820: c->self, c->rfd, len);
1821: chan_read_failed(c);
1822: return 0;
1823: }
1824: } else
1825: buffer_append(&c->input, buf, len);
1826: }
1827: return buffer_len(&c->input);
1828: }
1829:
1830: static void
1831: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1832: {
1833: u_int need;
1834: ssize_t len;
1835:
1836: if (!compat20)
1837: fatal("%s: entered with !compat20", __func__);
1838:
1.304 djm 1839: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1840: (c->istate == CHAN_INPUT_OPEN ||
1841: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1842: /*
1843: * Don't not read past the precise end of packets to
1844: * avoid disrupting fd passing.
1845: */
1846: if (read_mux(c, 4) < 4) /* read header */
1847: return;
1848: need = get_u32(buffer_ptr(&c->input));
1849: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1850: if (need > CHANNEL_MUX_MAX_PACKET) {
1851: debug2("channel %d: packet too big %u > %u",
1852: c->self, CHANNEL_MUX_MAX_PACKET, need);
1853: chan_rcvd_oclose(c);
1854: return;
1855: }
1856: if (read_mux(c, need + 4) < need + 4) /* read body */
1857: return;
1858: if (c->mux_rcb(c) != 0) {
1859: debug("channel %d: mux_rcb failed", c->self);
1860: chan_mark_dead(c);
1861: return;
1862: }
1863: }
1864:
1865: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1866: buffer_len(&c->output) > 0) {
1867: len = write(c->wfd, buffer_ptr(&c->output),
1868: buffer_len(&c->output));
1869: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1870: return;
1871: if (len <= 0) {
1872: chan_mark_dead(c);
1873: return;
1874: }
1875: buffer_consume(&c->output, len);
1876: }
1877: }
1878:
1879: static void
1880: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1881: {
1882: Channel *nc;
1883: struct sockaddr_storage addr;
1884: socklen_t addrlen;
1885: int newsock;
1886: uid_t euid;
1887: gid_t egid;
1888:
1889: if (!FD_ISSET(c->sock, readset))
1890: return;
1891:
1892: debug("multiplexing control connection");
1893:
1894: /*
1895: * Accept connection on control socket
1896: */
1897: memset(&addr, 0, sizeof(addr));
1898: addrlen = sizeof(addr);
1899: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1900: &addrlen)) == -1) {
1901: error("%s accept: %s", __func__, strerror(errno));
1.317 djm 1902: if (errno == EMFILE || errno == ENFILE)
1903: c->notbefore = time(NULL) + 1;
1.302 djm 1904: return;
1905: }
1906:
1907: if (getpeereid(newsock, &euid, &egid) < 0) {
1908: error("%s getpeereid failed: %s", __func__,
1909: strerror(errno));
1910: close(newsock);
1911: return;
1912: }
1913: if ((euid != 0) && (getuid() != euid)) {
1914: error("multiplex uid mismatch: peer euid %u != uid %u",
1915: (u_int)euid, (u_int)getuid());
1916: close(newsock);
1917: return;
1918: }
1919: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1920: newsock, newsock, -1, c->local_window_max,
1921: c->local_maxpacket, 0, "mux-control", 1);
1922: nc->mux_rcb = c->mux_rcb;
1923: debug3("%s: new mux channel %d fd %d", __func__,
1924: nc->self, nc->sock);
1925: /* establish state */
1926: nc->mux_rcb(nc);
1927: /* mux state transitions must not elicit protocol messages */
1928: nc->flags |= CHAN_LOCAL;
1929: }
1930:
1.259 stevesk 1931: /* ARGSUSED */
1.127 itojun 1932: static void
1.237 deraadt 1933: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1934: {
1.41 markus 1935: int len;
1.180 deraadt 1936:
1.41 markus 1937: /* Send buffered output data to the socket. */
1938: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1939: len = write(c->sock, buffer_ptr(&c->output),
1940: buffer_len(&c->output));
1941: if (len <= 0)
1.158 markus 1942: buffer_clear(&c->output);
1.41 markus 1943: else
1944: buffer_consume(&c->output, len);
1945: }
1946: }
1.25 markus 1947:
1.127 itojun 1948: static void
1.44 markus 1949: channel_handler_init_20(void)
1950: {
1.157 markus 1951: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1952: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1953: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1954: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1955: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1956: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1957: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1958: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 1959: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1960: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1961:
1.157 markus 1962: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1963: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1964: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1965: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1966: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1967: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1968: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 1969: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1970: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1971: }
1972:
1.127 itojun 1973: static void
1.41 markus 1974: channel_handler_init_13(void)
1975: {
1976: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1977: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1978: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1979: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1980: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1981: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1982: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1983: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1984: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1985:
1.157 markus 1986: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1987: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1988: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1989: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1990: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1991: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1992: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1993: }
1.25 markus 1994:
1.127 itojun 1995: static void
1.41 markus 1996: channel_handler_init_15(void)
1997: {
1.157 markus 1998: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1999: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 2000: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2001: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2002: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 2003: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 2004: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 2005:
1.41 markus 2006: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2007: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2008: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 2009: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 2010: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 2011: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 2012: }
1.27 markus 2013:
1.127 itojun 2014: static void
1.41 markus 2015: channel_handler_init(void)
2016: {
2017: int i;
1.180 deraadt 2018:
1.148 deraadt 2019: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2020: channel_pre[i] = NULL;
2021: channel_post[i] = NULL;
2022: }
1.44 markus 2023: if (compat20)
2024: channel_handler_init_20();
2025: else if (compat13)
1.41 markus 2026: channel_handler_init_13();
2027: else
2028: channel_handler_init_15();
2029: }
1.25 markus 2030:
1.140 markus 2031: /* gc dead channels */
2032: static void
2033: channel_garbage_collect(Channel *c)
2034: {
2035: if (c == NULL)
2036: return;
2037: if (c->detach_user != NULL) {
1.225 djm 2038: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2039: return;
1.194 markus 2040: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2041: c->detach_user(c->self, NULL);
2042: /* if we still have a callback */
2043: if (c->detach_user != NULL)
2044: return;
1.194 markus 2045: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2046: }
2047: if (!chan_is_dead(c, 1))
2048: return;
1.194 markus 2049: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2050: channel_free(c);
2051: }
2052:
1.127 itojun 2053: static void
1.317 djm 2054: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2055: time_t *unpause_secs)
1.41 markus 2056: {
2057: static int did_init = 0;
1.299 markus 2058: u_int i, oalloc;
1.41 markus 2059: Channel *c;
1.317 djm 2060: time_t now;
1.25 markus 2061:
1.41 markus 2062: if (!did_init) {
2063: channel_handler_init();
2064: did_init = 1;
2065: }
1.317 djm 2066: now = time(NULL);
2067: if (unpause_secs != NULL)
2068: *unpause_secs = 0;
1.299 markus 2069: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2070: c = channels[i];
2071: if (c == NULL)
1.41 markus 2072: continue;
1.299 markus 2073: if (c->delayed) {
2074: if (ftab == channel_pre)
2075: c->delayed = 0;
2076: else
2077: continue;
2078: }
1.317 djm 2079: if (ftab[c->type] != NULL) {
2080: /*
2081: * Run handlers that are not paused.
2082: */
2083: if (c->notbefore <= now)
2084: (*ftab[c->type])(c, readset, writeset);
2085: else if (unpause_secs != NULL) {
2086: /*
2087: * Collect the time that the earliest
2088: * channel comes off pause.
2089: */
2090: debug3("%s: chan %d: skip for %d more seconds",
2091: __func__, c->self,
2092: (int)(c->notbefore - now));
2093: if (*unpause_secs == 0 ||
2094: (c->notbefore - now) < *unpause_secs)
2095: *unpause_secs = c->notbefore - now;
2096: }
2097: }
1.140 markus 2098: channel_garbage_collect(c);
1.1 deraadt 2099: }
1.317 djm 2100: if (unpause_secs != NULL && *unpause_secs != 0)
2101: debug3("%s: first channel unpauses in %d seconds",
2102: __func__, (int)*unpause_secs);
1.1 deraadt 2103: }
2104:
1.121 markus 2105: /*
2106: * Allocate/update select bitmasks and add any bits relevant to channels in
2107: * select bitmasks.
2108: */
1.49 markus 2109: void
1.100 markus 2110: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.318 djm 2111: u_int *nallocp, time_t *minwait_secs, int rekeying)
1.41 markus 2112: {
1.243 djm 2113: u_int n, sz, nfdset;
1.84 markus 2114:
2115: n = MAX(*maxfdp, channel_max_fd);
2116:
1.243 djm 2117: nfdset = howmany(n+1, NFDBITS);
2118: /* Explicitly test here, because xrealloc isn't always called */
2119: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2120: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2121: sz = nfdset * sizeof(fd_mask);
2122:
1.132 markus 2123: /* perhaps check sz < nalloc/2 and shrink? */
2124: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2125: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2126: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2127: *nallocp = sz;
1.84 markus 2128: }
1.132 markus 2129: *maxfdp = n;
1.84 markus 2130: memset(*readsetp, 0, sz);
2131: memset(*writesetp, 0, sz);
2132:
1.100 markus 2133: if (!rekeying)
1.317 djm 2134: channel_handler(channel_pre, *readsetp, *writesetp,
2135: minwait_secs);
1.41 markus 2136: }
2137:
1.121 markus 2138: /*
2139: * After select, perform any appropriate operations for channels which have
2140: * events pending.
2141: */
1.49 markus 2142: void
1.237 deraadt 2143: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2144: {
1.317 djm 2145: channel_handler(channel_post, readset, writeset, NULL);
1.41 markus 2146: }
2147:
1.121 markus 2148:
1.84 markus 2149: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2150: void
1.142 itojun 2151: channel_output_poll(void)
1.1 deraadt 2152: {
1.41 markus 2153: Channel *c;
1.209 avsm 2154: u_int i, len;
1.1 deraadt 2155:
1.25 markus 2156: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2157: c = channels[i];
2158: if (c == NULL)
2159: continue;
1.37 markus 2160:
1.121 markus 2161: /*
2162: * We are only interested in channels that can have buffered
2163: * incoming data.
2164: */
1.37 markus 2165: if (compat13) {
1.41 markus 2166: if (c->type != SSH_CHANNEL_OPEN &&
2167: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2168: continue;
2169: } else {
1.41 markus 2170: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2171: continue;
2172: }
1.46 markus 2173: if (compat20 &&
2174: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2175: /* XXX is this true? */
1.140 markus 2176: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2177: continue;
2178: }
1.25 markus 2179:
2180: /* Get the amount of buffered data for this channel. */
1.93 markus 2181: if ((c->istate == CHAN_INPUT_OPEN ||
2182: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2183: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2184: if (c->datagram) {
2185: if (len > 0) {
2186: u_char *data;
2187: u_int dlen;
2188:
2189: data = buffer_get_string(&c->input,
2190: &dlen);
1.309 djm 2191: if (dlen > c->remote_window ||
2192: dlen > c->remote_maxpacket) {
2193: debug("channel %d: datagram "
2194: "too big for channel",
2195: c->self);
1.321 ! djm 2196: free(data);
1.309 djm 2197: continue;
2198: }
1.228 reyk 2199: packet_start(SSH2_MSG_CHANNEL_DATA);
2200: packet_put_int(c->remote_id);
2201: packet_put_string(data, dlen);
2202: packet_send();
2203: c->remote_window -= dlen + 4;
1.321 ! djm 2204: free(data);
1.228 reyk 2205: }
2206: continue;
2207: }
1.121 markus 2208: /*
2209: * Send some data for the other side over the secure
2210: * connection.
2211: */
1.44 markus 2212: if (compat20) {
2213: if (len > c->remote_window)
2214: len = c->remote_window;
2215: if (len > c->remote_maxpacket)
2216: len = c->remote_maxpacket;
1.25 markus 2217: } else {
1.44 markus 2218: if (packet_is_interactive()) {
2219: if (len > 1024)
2220: len = 512;
2221: } else {
2222: /* Keep the packets at reasonable size. */
2223: if (len > packet_get_maxsize()/2)
2224: len = packet_get_maxsize()/2;
2225: }
1.25 markus 2226: }
1.41 markus 2227: if (len > 0) {
1.44 markus 2228: packet_start(compat20 ?
2229: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2230: packet_put_int(c->remote_id);
2231: packet_put_string(buffer_ptr(&c->input), len);
2232: packet_send();
2233: buffer_consume(&c->input, len);
2234: c->remote_window -= len;
2235: }
2236: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2237: if (compat13)
2238: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2239: /*
2240: * input-buffer is empty and read-socket shutdown:
1.172 markus 2241: * tell peer, that we will not send more data: send IEOF.
2242: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2243: */
1.172 markus 2244: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2245: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2246: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2247: else
2248: chan_ibuf_empty(c);
1.25 markus 2249: }
1.44 markus 2250: /* Send extended data, i.e. stderr */
2251: if (compat20 &&
1.172 markus 2252: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2253: c->remote_window > 0 &&
2254: (len = buffer_len(&c->extended)) > 0 &&
2255: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2256: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2257: c->self, c->remote_window, buffer_len(&c->extended),
2258: c->extended_usage);
1.44 markus 2259: if (len > c->remote_window)
2260: len = c->remote_window;
2261: if (len > c->remote_maxpacket)
2262: len = c->remote_maxpacket;
2263: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2264: packet_put_int(c->remote_id);
2265: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2266: packet_put_string(buffer_ptr(&c->extended), len);
2267: packet_send();
2268: buffer_consume(&c->extended, len);
2269: c->remote_window -= len;
1.93 markus 2270: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2271: }
1.25 markus 2272: }
1.1 deraadt 2273: }
2274:
1.121 markus 2275:
2276: /* -- protocol input */
1.249 djm 2277:
2278: /* ARGSUSED */
1.49 markus 2279: void
1.154 markus 2280: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2281: {
1.37 markus 2282: int id;
1.25 markus 2283: char *data;
1.309 djm 2284: u_int data_len, win_len;
1.41 markus 2285: Channel *c;
1.25 markus 2286:
2287: /* Get the channel number and verify it. */
1.37 markus 2288: id = packet_get_int();
1.41 markus 2289: c = channel_lookup(id);
2290: if (c == NULL)
1.37 markus 2291: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2292:
2293: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2294: if (c->type != SSH_CHANNEL_OPEN &&
2295: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2296: return;
2297:
1.25 markus 2298: /* Get the data. */
1.274 markus 2299: data = packet_get_string_ptr(&data_len);
1.309 djm 2300: win_len = data_len;
2301: if (c->datagram)
2302: win_len += 4; /* string length header */
1.200 markus 2303:
2304: /*
2305: * Ignore data for protocol > 1.3 if output end is no longer open.
2306: * For protocol 2 the sending side is reducing its window as it sends
2307: * data, so we must 'fake' consumption of the data in order to ensure
2308: * that window updates are sent back. Otherwise the connection might
2309: * deadlock.
2310: */
2311: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2312: if (compat20) {
1.309 djm 2313: c->local_window -= win_len;
2314: c->local_consumed += win_len;
1.200 markus 2315: }
2316: return;
2317: }
1.41 markus 2318:
1.143 deraadt 2319: if (compat20) {
1.309 djm 2320: if (win_len > c->local_maxpacket) {
1.188 itojun 2321: logit("channel %d: rcvd big packet %d, maxpack %d",
1.309 djm 2322: c->self, win_len, c->local_maxpacket);
1.44 markus 2323: }
1.309 djm 2324: if (win_len > c->local_window) {
1.188 itojun 2325: logit("channel %d: rcvd too much data %d, win %d",
1.309 djm 2326: c->self, win_len, c->local_window);
1.44 markus 2327: return;
2328: }
1.309 djm 2329: c->local_window -= win_len;
1.44 markus 2330: }
1.228 reyk 2331: if (c->datagram)
2332: buffer_put_string(&c->output, data, data_len);
2333: else
2334: buffer_append(&c->output, data, data_len);
1.274 markus 2335: packet_check_eom();
1.1 deraadt 2336: }
1.121 markus 2337:
1.249 djm 2338: /* ARGSUSED */
1.49 markus 2339: void
1.154 markus 2340: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2341: {
2342: int id;
2343: char *data;
1.177 markus 2344: u_int data_len, tcode;
1.44 markus 2345: Channel *c;
2346:
2347: /* Get the channel number and verify it. */
2348: id = packet_get_int();
2349: c = channel_lookup(id);
2350:
2351: if (c == NULL)
2352: packet_disconnect("Received extended_data for bad channel %d.", id);
2353: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2354: logit("channel %d: ext data for non open", id);
1.44 markus 2355: return;
1.172 markus 2356: }
2357: if (c->flags & CHAN_EOF_RCVD) {
2358: if (datafellows & SSH_BUG_EXTEOF)
2359: debug("channel %d: accepting ext data after eof", id);
2360: else
2361: packet_disconnect("Received extended_data after EOF "
2362: "on channel %d.", id);
1.44 markus 2363: }
2364: tcode = packet_get_int();
2365: if (c->efd == -1 ||
2366: c->extended_usage != CHAN_EXTENDED_WRITE ||
2367: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2368: logit("channel %d: bad ext data", c->self);
1.44 markus 2369: return;
2370: }
2371: data = packet_get_string(&data_len);
1.152 markus 2372: packet_check_eom();
1.44 markus 2373: if (data_len > c->local_window) {
1.188 itojun 2374: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2375: c->self, data_len, c->local_window);
1.321 ! djm 2376: free(data);
1.44 markus 2377: return;
2378: }
1.70 markus 2379: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2380: c->local_window -= data_len;
2381: buffer_append(&c->extended, data, data_len);
1.321 ! djm 2382: free(data);
1.44 markus 2383: }
2384:
1.249 djm 2385: /* ARGSUSED */
1.49 markus 2386: void
1.154 markus 2387: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2388: {
2389: int id;
2390: Channel *c;
2391:
2392: id = packet_get_int();
1.152 markus 2393: packet_check_eom();
1.41 markus 2394: c = channel_lookup(id);
2395: if (c == NULL)
2396: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2397: chan_rcvd_ieof(c);
1.133 markus 2398:
2399: /* XXX force input close */
1.156 markus 2400: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2401: debug("channel %d: FORCE input drain", c->self);
2402: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2403: if (buffer_len(&c->input) == 0)
2404: chan_ibuf_empty(c);
1.133 markus 2405: }
2406:
1.41 markus 2407: }
1.1 deraadt 2408:
1.249 djm 2409: /* ARGSUSED */
1.49 markus 2410: void
1.154 markus 2411: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2412: {
1.41 markus 2413: int id;
2414: Channel *c;
1.1 deraadt 2415:
1.41 markus 2416: id = packet_get_int();
1.152 markus 2417: packet_check_eom();
1.41 markus 2418: c = channel_lookup(id);
2419: if (c == NULL)
2420: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2421:
2422: /*
2423: * Send a confirmation that we have closed the channel and no more
2424: * data is coming for it.
2425: */
1.25 markus 2426: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2427: packet_put_int(c->remote_id);
1.25 markus 2428: packet_send();
2429:
1.27 markus 2430: /*
2431: * If the channel is in closed state, we have sent a close request,
2432: * and the other side will eventually respond with a confirmation.
2433: * Thus, we cannot free the channel here, because then there would be
2434: * no-one to receive the confirmation. The channel gets freed when
2435: * the confirmation arrives.
2436: */
1.41 markus 2437: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2438: /*
2439: * Not a closed channel - mark it as draining, which will
2440: * cause it to be freed later.
2441: */
1.158 markus 2442: buffer_clear(&c->input);
1.41 markus 2443: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2444: }
1.1 deraadt 2445: }
2446:
1.41 markus 2447: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2448: /* ARGSUSED */
1.49 markus 2449: void
1.154 markus 2450: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2451: {
2452: int id = packet_get_int();
2453: Channel *c = channel_lookup(id);
1.151 markus 2454:
1.152 markus 2455: packet_check_eom();
1.41 markus 2456: if (c == NULL)
2457: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2458: chan_rcvd_oclose(c);
2459: }
1.1 deraadt 2460:
1.249 djm 2461: /* ARGSUSED */
1.49 markus 2462: void
1.154 markus 2463: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2464: {
1.41 markus 2465: int id = packet_get_int();
2466: Channel *c = channel_lookup(id);
1.1 deraadt 2467:
1.152 markus 2468: packet_check_eom();
1.41 markus 2469: if (c == NULL)
2470: packet_disconnect("Received close confirmation for "
2471: "out-of-range channel %d.", id);
2472: if (c->type != SSH_CHANNEL_CLOSED)
2473: packet_disconnect("Received close confirmation for "
2474: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2475: channel_free(c);
1.1 deraadt 2476: }
2477:
1.249 djm 2478: /* ARGSUSED */
1.49 markus 2479: void
1.154 markus 2480: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2481: {
1.41 markus 2482: int id, remote_id;
2483: Channel *c;
1.1 deraadt 2484:
1.41 markus 2485: id = packet_get_int();
2486: c = channel_lookup(id);
1.25 markus 2487:
1.41 markus 2488: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2489: packet_disconnect("Received open confirmation for "
2490: "non-opening channel %d.", id);
2491: remote_id = packet_get_int();
1.27 markus 2492: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2493: c->remote_id = remote_id;
2494: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2495:
2496: if (compat20) {
2497: c->remote_window = packet_get_int();
2498: c->remote_maxpacket = packet_get_int();
1.275 djm 2499: if (c->open_confirm) {
1.70 markus 2500: debug2("callback start");
1.304 djm 2501: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2502: debug2("callback done");
1.44 markus 2503: }
1.194 markus 2504: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2505: c->remote_window, c->remote_maxpacket);
2506: }
1.152 markus 2507: packet_check_eom();
1.1 deraadt 2508: }
2509:
1.127 itojun 2510: static char *
1.114 markus 2511: reason2txt(int reason)
2512: {
1.143 deraadt 2513: switch (reason) {
1.114 markus 2514: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2515: return "administratively prohibited";
2516: case SSH2_OPEN_CONNECT_FAILED:
2517: return "connect failed";
2518: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2519: return "unknown channel type";
2520: case SSH2_OPEN_RESOURCE_SHORTAGE:
2521: return "resource shortage";
2522: }
1.117 stevesk 2523: return "unknown reason";
1.114 markus 2524: }
2525:
1.249 djm 2526: /* ARGSUSED */
1.49 markus 2527: void
1.154 markus 2528: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2529: {
1.86 markus 2530: int id, reason;
2531: char *msg = NULL, *lang = NULL;
1.41 markus 2532: Channel *c;
2533:
2534: id = packet_get_int();
2535: c = channel_lookup(id);
1.25 markus 2536:
1.41 markus 2537: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2538: packet_disconnect("Received open failure for "
2539: "non-opening channel %d.", id);
1.44 markus 2540: if (compat20) {
1.86 markus 2541: reason = packet_get_int();
1.110 markus 2542: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2543: msg = packet_get_string(NULL);
2544: lang = packet_get_string(NULL);
2545: }
1.188 itojun 2546: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2547: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.321 ! djm 2548: free(msg);
! 2549: free(lang);
1.304 djm 2550: if (c->open_confirm) {
2551: debug2("callback start");
2552: c->open_confirm(c->self, 0, c->open_confirm_ctx);
2553: debug2("callback done");
2554: }
1.44 markus 2555: }
1.152 markus 2556: packet_check_eom();
1.291 djm 2557: /* Schedule the channel for cleanup/deletion. */
2558: chan_mark_dead(c);
1.44 markus 2559: }
2560:
1.249 djm 2561: /* ARGSUSED */
1.121 markus 2562: void
1.154 markus 2563: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2564: {
2565: Channel *c;
1.178 markus 2566: int id;
2567: u_int adjust;
1.121 markus 2568:
2569: if (!compat20)
2570: return;
2571:
2572: /* Get the channel number and verify it. */
2573: id = packet_get_int();
2574: c = channel_lookup(id);
1.1 deraadt 2575:
1.229 markus 2576: if (c == NULL) {
2577: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2578: return;
2579: }
2580: adjust = packet_get_int();
1.152 markus 2581: packet_check_eom();
1.178 markus 2582: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2583: c->remote_window += adjust;
2584: }
1.1 deraadt 2585:
1.249 djm 2586: /* ARGSUSED */
1.121 markus 2587: void
1.154 markus 2588: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2589: {
1.121 markus 2590: Channel *c = NULL;
2591: u_short host_port;
2592: char *host, *originator_string;
1.276 djm 2593: int remote_id;
1.121 markus 2594:
2595: remote_id = packet_get_int();
2596: host = packet_get_string(NULL);
2597: host_port = packet_get_int();
1.25 markus 2598:
1.121 markus 2599: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2600: originator_string = packet_get_string(NULL);
2601: } else {
2602: originator_string = xstrdup("unknown (remote did not supply name)");
2603: }
1.152 markus 2604: packet_check_eom();
1.276 djm 2605: c = channel_connect_to(host, host_port,
2606: "connected socket", originator_string);
1.321 ! djm 2607: free(originator_string);
! 2608: free(host);
1.121 markus 2609: if (c == NULL) {
2610: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2611: packet_put_int(remote_id);
2612: packet_send();
1.276 djm 2613: } else
2614: c->remote_id = remote_id;
1.1 deraadt 2615: }
2616:
1.275 djm 2617: /* ARGSUSED */
2618: void
2619: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2620: {
2621: Channel *c;
2622: struct channel_confirm *cc;
1.289 markus 2623: int id;
1.275 djm 2624:
2625: /* Reset keepalive timeout */
1.296 andreas 2626: packet_set_alive_timeouts(0);
1.275 djm 2627:
1.289 markus 2628: id = packet_get_int();
1.275 djm 2629: packet_check_eom();
2630:
1.289 markus 2631: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2632:
1.289 markus 2633: if ((c = channel_lookup(id)) == NULL) {
2634: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2635: return;
2636: }
2637: ;
2638: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2639: return;
2640: cc->cb(type, c, cc->ctx);
2641: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2642: bzero(cc, sizeof(*cc));
1.321 ! djm 2643: free(cc);
1.275 djm 2644: }
1.121 markus 2645:
2646: /* -- tcp forwarding */
1.135 markus 2647:
2648: void
2649: channel_set_af(int af)
2650: {
2651: IPv4or6 = af;
2652: }
1.121 markus 2653:
1.312 djm 2654:
2655: /*
2656: * Determine whether or not a port forward listens to loopback, the
2657: * specified address or wildcard. On the client, a specified bind
2658: * address will always override gateway_ports. On the server, a
2659: * gateway_ports of 1 (``yes'') will override the client's specification
2660: * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2661: * will bind to whatever address the client asked for.
2662: *
2663: * Special-case listen_addrs are:
2664: *
2665: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2666: * "" (empty string), "*" -> wildcard v4/v6
2667: * "localhost" -> loopback v4/v6
2668: */
2669: static const char *
2670: channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2671: int is_client, int gateway_ports)
2672: {
2673: const char *addr = NULL;
2674: int wildcard = 0;
2675:
2676: if (listen_addr == NULL) {
2677: /* No address specified: default to gateway_ports setting */
2678: if (gateway_ports)
2679: wildcard = 1;
2680: } else if (gateway_ports || is_client) {
2681: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2682: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2683: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2684: (!is_client && gateway_ports == 1))
2685: wildcard = 1;
2686: else if (strcmp(listen_addr, "localhost") != 0)
2687: addr = listen_addr;
2688: }
2689: if (wildcardp != NULL)
2690: *wildcardp = wildcard;
2691: return addr;
2692: }
2693:
1.160 markus 2694: static int
1.295 djm 2695: channel_setup_fwd_listener(int type, const char *listen_addr,
2696: u_short listen_port, int *allocated_listen_port,
1.160 markus 2697: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2698: {
1.113 markus 2699: Channel *c;
1.226 djm 2700: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2701: struct addrinfo hints, *ai, *aitop;
1.212 djm 2702: const char *host, *addr;
1.35 markus 2703: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2704: in_port_t *lport_p;
1.25 markus 2705:
1.160 markus 2706: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2707: listen_addr : host_to_connect;
1.212 djm 2708: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2709:
1.160 markus 2710: if (host == NULL) {
2711: error("No forward host name.");
1.218 markus 2712: return 0;
1.73 markus 2713: }
1.294 djm 2714: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2715: error("Forward host name too long.");
1.218 markus 2716: return 0;
1.87 markus 2717: }
1.25 markus 2718:
1.312 djm 2719: /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2720: addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2721: is_client, gateway_ports);
1.212 djm 2722: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2723: type, wildcard, (addr == NULL) ? "NULL" : addr);
2724:
2725: /*
1.35 markus 2726: * getaddrinfo returns a loopback address if the hostname is
2727: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2728: */
1.35 markus 2729: memset(&hints, 0, sizeof(hints));
2730: hints.ai_family = IPv4or6;
1.212 djm 2731: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2732: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2733: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2734: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2735: if (addr == NULL) {
2736: /* This really shouldn't happen */
2737: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2738: ssh_gai_strerror(r));
1.212 djm 2739: } else {
1.218 markus 2740: error("channel_setup_fwd_listener: "
1.271 dtucker 2741: "getaddrinfo(%.64s): %s", addr,
2742: ssh_gai_strerror(r));
1.212 djm 2743: }
1.218 markus 2744: return 0;
1.212 djm 2745: }
1.295 djm 2746: if (allocated_listen_port != NULL)
2747: *allocated_listen_port = 0;
1.35 markus 2748: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2749: switch (ai->ai_family) {
2750: case AF_INET:
2751: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2752: sin_port;
2753: break;
2754: case AF_INET6:
2755: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2756: sin6_port;
2757: break;
2758: default:
1.35 markus 2759: continue;
1.295 djm 2760: }
2761: /*
2762: * If allocating a port for -R forwards, then use the
2763: * same port for all address families.
2764: */
2765: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2766: allocated_listen_port != NULL && *allocated_listen_port > 0)
2767: *lport_p = htons(*allocated_listen_port);
2768:
1.35 markus 2769: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2770: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2771: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2772: continue;
2773: }
2774: /* Create a port to listen for the host. */
1.300 dtucker 2775: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2776: if (sock < 0) {
2777: /* this is no error since kernel may not support ipv6 */
2778: verbose("socket: %.100s", strerror(errno));
2779: continue;
2780: }
1.226 djm 2781:
2782: channel_set_reuseaddr(sock);
1.182 stevesk 2783:
1.295 djm 2784: debug("Local forwarding listening on %s port %s.",
2785: ntop, strport);
1.35 markus 2786:
2787: /* Bind the socket to the address. */
2788: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2789: /* address can be in use ipv6 address is already bound */
2790: verbose("bind: %.100s", strerror(errno));
2791: close(sock);
2792: continue;
2793: }
2794: /* Start listening for connections on the socket. */
1.199 markus 2795: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2796: error("listen: %.100s", strerror(errno));
2797: close(sock);
2798: continue;
2799: }
1.295 djm 2800:
2801: /*
2802: * listen_port == 0 requests a dynamically allocated port -
2803: * record what we got.
2804: */
2805: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2806: allocated_listen_port != NULL &&
2807: *allocated_listen_port == 0) {
2808: *allocated_listen_port = get_sock_port(sock, 1);
2809: debug("Allocated listen port %d",
2810: *allocated_listen_port);
2811: }
2812:
1.35 markus 2813: /* Allocate a channel number for the socket. */
1.121 markus 2814: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2815: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2816: 0, "port listener", 1);
1.293 djm 2817: c->path = xstrdup(host);
1.113 markus 2818: c->host_port = port_to_connect;
1.312 djm 2819: c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
1.315 markus 2820: if (listen_port == 0 && allocated_listen_port != NULL &&
2821: !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2822: c->listening_port = *allocated_listen_port;
2823: else
2824: c->listening_port = listen_port;
1.35 markus 2825: success = 1;
2826: }
2827: if (success == 0)
1.160 markus 2828: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2829: listen_port);
1.35 markus 2830: freeaddrinfo(aitop);
1.87 markus 2831: return success;
1.25 markus 2832: }
1.1 deraadt 2833:
1.202 djm 2834: int
2835: channel_cancel_rport_listener(const char *host, u_short port)
2836: {
1.209 avsm 2837: u_int i;
2838: int found = 0;
1.202 djm 2839:
1.213 deraadt 2840: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2841: Channel *c = channels[i];
1.312 djm 2842: if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2843: continue;
2844: if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2845: debug2("%s: close channel %d", __func__, i);
2846: channel_free(c);
2847: found = 1;
2848: }
2849: }
2850:
2851: return (found);
2852: }
2853:
2854: int
2855: channel_cancel_lport_listener(const char *lhost, u_short lport,
1.313 markus 2856: int cport, int gateway_ports)
1.312 djm 2857: {
2858: u_int i;
2859: int found = 0;
2860: const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
1.202 djm 2861:
1.312 djm 2862: for (i = 0; i < channels_alloc; i++) {
2863: Channel *c = channels[i];
2864: if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2865: continue;
1.313 markus 2866: if (c->listening_port != lport)
1.312 djm 2867: continue;
1.313 markus 2868: if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2869: /* skip dynamic forwardings */
2870: if (c->host_port == 0)
2871: continue;
2872: } else {
2873: if (c->host_port != cport)
2874: continue;
2875: }
1.312 djm 2876: if ((c->listening_addr == NULL && addr != NULL) ||
2877: (c->listening_addr != NULL && addr == NULL))
2878: continue;
2879: if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
1.210 djm 2880: debug2("%s: close channel %d", __func__, i);
1.202 djm 2881: channel_free(c);
2882: found = 1;
2883: }
2884: }
2885:
2886: return (found);
2887: }
2888:
1.160 markus 2889: /* protocol local port fwd, used by ssh (and sshd in v1) */
2890: int
1.212 djm 2891: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2892: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2893: {
2894: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2895: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2896: gateway_ports);
1.160 markus 2897: }
2898:
2899: /* protocol v2 remote port fwd, used by sshd */
2900: int
2901: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2902: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2903: {
2904: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2905: listen_address, listen_port, allocated_listen_port,
2906: NULL, 0, gateway_ports);
1.160 markus 2907: }
2908:
1.27 markus 2909: /*
1.312 djm 2910: * Translate the requested rfwd listen host to something usable for
2911: * this server.
2912: */
2913: static const char *
2914: channel_rfwd_bind_host(const char *listen_host)
2915: {
2916: if (listen_host == NULL) {
2917: if (datafellows & SSH_BUG_RFWD_ADDR)
2918: return "127.0.0.1";
2919: else
2920: return "localhost";
2921: } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
2922: if (datafellows & SSH_BUG_RFWD_ADDR)
2923: return "0.0.0.0";
2924: else
2925: return "";
2926: } else
2927: return listen_host;
2928: }
2929:
2930: /*
1.27 markus 2931: * Initiate forwarding of connections to port "port" on remote host through
2932: * the secure channel to host:port from local side.
1.315 markus 2933: * Returns handle (index) for updating the dynamic listen port with
2934: * channel_update_permitted_opens().
1.27 markus 2935: */
1.253 markus 2936: int
1.212 djm 2937: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2938: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2939: {
1.315 markus 2940: int type, success = 0, idx = -1;
1.73 markus 2941:
1.25 markus 2942: /* Send the forward request to the remote side. */
1.44 markus 2943: if (compat20) {
2944: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2945: packet_put_cstring("tcpip-forward");
1.312 djm 2946: packet_put_char(1); /* boolean: want reply */
2947: packet_put_cstring(channel_rfwd_bind_host(listen_host));
1.44 markus 2948: packet_put_int(listen_port);
1.73 markus 2949: packet_send();
2950: packet_write_wait();
2951: /* Assume that server accepts the request */
2952: success = 1;
1.44 markus 2953: } else {
2954: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2955: packet_put_int(listen_port);
2956: packet_put_cstring(host_to_connect);
1.44 markus 2957: packet_put_int(port_to_connect);
2958: packet_send();
2959: packet_write_wait();
1.73 markus 2960:
2961: /* Wait for response from the remote side. */
1.153 markus 2962: type = packet_read();
1.73 markus 2963: switch (type) {
2964: case SSH_SMSG_SUCCESS:
2965: success = 1;
2966: break;
2967: case SSH_SMSG_FAILURE:
2968: break;
2969: default:
2970: /* Unknown packet */
2971: packet_disconnect("Protocol error for port forward request:"
2972: "received packet type %d.", type);
2973: }
2974: }
2975: if (success) {
1.305 djm 2976: /* Record that connection to this host/port is permitted. */
2977: permitted_opens = xrealloc(permitted_opens,
2978: num_permitted_opens + 1, sizeof(*permitted_opens));
1.315 markus 2979: idx = num_permitted_opens++;
2980: permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
2981: permitted_opens[idx].port_to_connect = port_to_connect;
2982: permitted_opens[idx].listen_port = listen_port;
1.44 markus 2983: }
1.315 markus 2984: return (idx);
1.1 deraadt 2985: }
2986:
1.27 markus 2987: /*
1.208 deraadt 2988: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2989: * local side.
2990: */
1.312 djm 2991: int
1.212 djm 2992: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2993: {
2994: int i;
2995:
2996: if (!compat20)
1.312 djm 2997: return -1;
1.202 djm 2998:
2999: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 3000: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 3001: permitted_opens[i].listen_port == port)
3002: break;
3003: }
3004: if (i >= num_permitted_opens) {
3005: debug("%s: requested forward not found", __func__);
1.312 djm 3006: return -1;
1.202 djm 3007: }
3008: packet_start(SSH2_MSG_GLOBAL_REQUEST);
3009: packet_put_cstring("cancel-tcpip-forward");
3010: packet_put_char(0);
1.312 djm 3011: packet_put_cstring(channel_rfwd_bind_host(host));
1.202 djm 3012: packet_put_int(port);
3013: packet_send();
3014:
3015: permitted_opens[i].listen_port = 0;
3016: permitted_opens[i].port_to_connect = 0;
1.321 ! djm 3017: free(permitted_opens[i].host_to_connect);
1.202 djm 3018: permitted_opens[i].host_to_connect = NULL;
1.312 djm 3019:
3020: return 0;
1.202 djm 3021: }
3022:
3023: /*
1.27 markus 3024: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3025: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 3026: * message if there was an error).
1.27 markus 3027: */
1.253 markus 3028: int
1.56 markus 3029: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 3030: {
1.31 markus 3031: u_short port, host_port;
1.253 markus 3032: int success = 0;
1.25 markus 3033: char *hostname;
1.1 deraadt 3034:
1.25 markus 3035: /* Get arguments from the packet. */
3036: port = packet_get_int();
3037: hostname = packet_get_string(NULL);
3038: host_port = packet_get_int();
3039:
1.27 markus 3040: /*
3041: * Check that an unprivileged user is not trying to forward a
3042: * privileged port.
3043: */
1.25 markus 3044: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 3045: packet_disconnect(
3046: "Requested forwarding of port %d but user is not root.",
3047: port);
3048: if (host_port == 0)
3049: packet_disconnect("Dynamic forwarding denied.");
3050:
1.73 markus 3051: /* Initiate forwarding */
1.253 markus 3052: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 3053: host_port, gateway_ports);
1.25 markus 3054:
3055: /* Free the argument string. */
1.321 ! djm 3056: free(hostname);
1.253 markus 3057:
3058: return (success ? 0 : -1);
1.1 deraadt 3059: }
3060:
1.99 markus 3061: /*
3062: * Permits opening to any host/port if permitted_opens[] is empty. This is
3063: * usually called by the server, because the user could connect to any port
3064: * anyway, and the server has no way to know but to trust the client anyway.
3065: */
3066: void
1.142 itojun 3067: channel_permit_all_opens(void)
1.99 markus 3068: {
3069: if (num_permitted_opens == 0)
3070: all_opens_permitted = 1;
3071: }
3072:
1.101 markus 3073: void
1.99 markus 3074: channel_add_permitted_opens(char *host, int port)
3075: {
3076: debug("allow port forwarding to host %s port %d", host, port);
3077:
1.305 djm 3078: permitted_opens = xrealloc(permitted_opens,
3079: num_permitted_opens + 1, sizeof(*permitted_opens));
1.99 markus 3080: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3081: permitted_opens[num_permitted_opens].port_to_connect = port;
3082: num_permitted_opens++;
3083:
3084: all_opens_permitted = 0;
1.315 markus 3085: }
3086:
3087: /*
3088: * Update the listen port for a dynamic remote forward, after
3089: * the actual 'newport' has been allocated. If 'newport' < 0 is
3090: * passed then they entry will be invalidated.
3091: */
3092: void
3093: channel_update_permitted_opens(int idx, int newport)
3094: {
3095: if (idx < 0 || idx >= num_permitted_opens) {
3096: debug("channel_update_permitted_opens: index out of range:"
3097: " %d num_permitted_opens %d", idx, num_permitted_opens);
3098: return;
3099: }
3100: debug("%s allowed port %d for forwarding to host %s port %d",
3101: newport > 0 ? "Updating" : "Removing",
3102: newport,
3103: permitted_opens[idx].host_to_connect,
3104: permitted_opens[idx].port_to_connect);
3105: if (newport >= 0) {
3106: permitted_opens[idx].listen_port =
3107: (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3108: } else {
3109: permitted_opens[idx].listen_port = 0;
3110: permitted_opens[idx].port_to_connect = 0;
1.321 ! djm 3111: free(permitted_opens[idx].host_to_connect);
1.315 markus 3112: permitted_opens[idx].host_to_connect = NULL;
3113: }
1.99 markus 3114: }
3115:
1.258 dtucker 3116: int
1.257 dtucker 3117: channel_add_adm_permitted_opens(char *host, int port)
3118: {
1.258 dtucker 3119: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 3120:
1.305 djm 3121: permitted_adm_opens = xrealloc(permitted_adm_opens,
3122: num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
1.257 dtucker 3123: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3124: = xstrdup(host);
3125: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 3126: return ++num_adm_permitted_opens;
1.257 dtucker 3127: }
3128:
3129: void
1.316 dtucker 3130: channel_disable_adm_local_opens(void)
3131: {
1.319 djm 3132: channel_clear_adm_permitted_opens();
3133: permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3134: permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3135: num_adm_permitted_opens = 1;
1.316 dtucker 3136: }
3137:
3138: void
1.99 markus 3139: channel_clear_permitted_opens(void)
3140: {
3141: int i;
3142:
3143: for (i = 0; i < num_permitted_opens; i++)
1.321 ! djm 3144: free(permitted_opens[i].host_to_connect);
! 3145: free(permitted_opens);
! 3146: permitted_opens = NULL;
1.99 markus 3147: num_permitted_opens = 0;
1.257 dtucker 3148: }
3149:
3150: void
3151: channel_clear_adm_permitted_opens(void)
3152: {
3153: int i;
1.99 markus 3154:
1.257 dtucker 3155: for (i = 0; i < num_adm_permitted_opens; i++)
1.321 ! djm 3156: free(permitted_adm_opens[i].host_to_connect);
! 3157: free(permitted_adm_opens);
! 3158: permitted_adm_opens = NULL;
1.257 dtucker 3159: num_adm_permitted_opens = 0;
1.278 dtucker 3160: }
3161:
3162: void
3163: channel_print_adm_permitted_opens(void)
3164: {
1.286 djm 3165: int i;
1.278 dtucker 3166:
1.290 stevesk 3167: printf("permitopen");
1.288 stevesk 3168: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3169: printf(" any\n");
1.288 stevesk 3170: return;
3171: }
1.278 dtucker 3172: for (i = 0; i < num_adm_permitted_opens; i++)
1.316 dtucker 3173: if (permitted_adm_opens[i].host_to_connect == NULL)
3174: printf(" none");
3175: else
1.278 dtucker 3176: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3177: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3178: printf("\n");
1.99 markus 3179: }
3180:
1.314 dtucker 3181: /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3182: int
3183: permitopen_port(const char *p)
3184: {
3185: int port;
3186:
3187: if (strcmp(p, "*") == 0)
3188: return FWD_PERMIT_ANY_PORT;
3189: if ((port = a2port(p)) > 0)
3190: return port;
3191: return -1;
3192: }
3193:
3194: static int
3195: port_match(u_short allowedport, u_short requestedport)
3196: {
3197: if (allowedport == FWD_PERMIT_ANY_PORT ||
3198: allowedport == requestedport)
3199: return 1;
3200: return 0;
3201: }
3202:
1.276 djm 3203: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3204: static int
1.276 djm 3205: connect_next(struct channel_connect *cctx)
1.41 markus 3206: {
1.276 djm 3207: int sock, saved_errno;
1.41 markus 3208: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3209:
1.276 djm 3210: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3211: if (cctx->ai->ai_family != AF_INET &&
3212: cctx->ai->ai_family != AF_INET6)
1.41 markus 3213: continue;
1.276 djm 3214: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3215: ntop, sizeof(ntop), strport, sizeof(strport),
3216: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3217: error("connect_next: getnameinfo failed");
1.41 markus 3218: continue;
3219: }
1.300 dtucker 3220: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3221: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3222: if (cctx->ai->ai_next == NULL)
1.186 djm 3223: error("socket: %.100s", strerror(errno));
3224: else
3225: verbose("socket: %.100s", strerror(errno));
1.41 markus 3226: continue;
3227: }
1.205 djm 3228: if (set_nonblock(sock) == -1)
3229: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3230: if (connect(sock, cctx->ai->ai_addr,
3231: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3232: debug("connect_next: host %.100s ([%.100s]:%s): "
3233: "%.100s", cctx->host, ntop, strport,
1.41 markus 3234: strerror(errno));
1.276 djm 3235: saved_errno = errno;
1.41 markus 3236: close(sock);
1.276 djm 3237: errno = saved_errno;
1.89 stevesk 3238: continue; /* fail -- try next */
1.41 markus 3239: }
1.276 djm 3240: debug("connect_next: host %.100s ([%.100s]:%s) "
3241: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3242: cctx->ai = cctx->ai->ai_next;
3243: set_nodelay(sock);
3244: return sock;
3245: }
3246: return -1;
3247: }
1.41 markus 3248:
1.276 djm 3249: static void
3250: channel_connect_ctx_free(struct channel_connect *cctx)
3251: {
1.321 ! djm 3252: free(cctx->host);
1.276 djm 3253: if (cctx->aitop)
3254: freeaddrinfo(cctx->aitop);
3255: bzero(cctx, sizeof(*cctx));
3256: cctx->host = NULL;
3257: cctx->ai = cctx->aitop = NULL;
3258: }
3259:
3260: /* Return CONNECTING channel to remote host, port */
3261: static Channel *
3262: connect_to(const char *host, u_short port, char *ctype, char *rname)
3263: {
3264: struct addrinfo hints;
3265: int gaierr;
3266: int sock = -1;
3267: char strport[NI_MAXSERV];
3268: struct channel_connect cctx;
3269: Channel *c;
3270:
1.284 djm 3271: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3272: memset(&hints, 0, sizeof(hints));
3273: hints.ai_family = IPv4or6;
3274: hints.ai_socktype = SOCK_STREAM;
3275: snprintf(strport, sizeof strport, "%d", port);
3276: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3277: error("connect_to %.100s: unknown host (%s)", host,
3278: ssh_gai_strerror(gaierr));
3279: return NULL;
1.41 markus 3280: }
1.276 djm 3281:
3282: cctx.host = xstrdup(host);
3283: cctx.port = port;
3284: cctx.ai = cctx.aitop;
3285:
3286: if ((sock = connect_next(&cctx)) == -1) {
3287: error("connect to %.100s port %d failed: %s",
3288: host, port, strerror(errno));
3289: channel_connect_ctx_free(&cctx);
3290: return NULL;
1.41 markus 3291: }
1.276 djm 3292: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3293: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3294: c->connect_ctx = cctx;
3295: return c;
1.41 markus 3296: }
1.99 markus 3297:
1.276 djm 3298: Channel *
3299: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3300: {
3301: int i;
1.99 markus 3302:
1.276 djm 3303: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3304: if (permitted_opens[i].host_to_connect != NULL &&
1.314 dtucker 3305: port_match(permitted_opens[i].listen_port, listen_port)) {
1.99 markus 3306: return connect_to(
1.73 markus 3307: permitted_opens[i].host_to_connect,
1.276 djm 3308: permitted_opens[i].port_to_connect, ctype, rname);
3309: }
3310: }
1.74 markus 3311: error("WARNING: Server requests forwarding for unknown listen_port %d",
3312: listen_port);
1.276 djm 3313: return NULL;
1.73 markus 3314: }
3315:
1.99 markus 3316: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3317: Channel *
3318: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3319: {
1.257 dtucker 3320: int i, permit, permit_adm = 1;
1.99 markus 3321:
3322: permit = all_opens_permitted;
3323: if (!permit) {
3324: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3325: if (permitted_opens[i].host_to_connect != NULL &&
1.314 dtucker 3326: port_match(permitted_opens[i].port_to_connect, port) &&
1.99 markus 3327: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3328: permit = 1;
1.257 dtucker 3329: }
1.99 markus 3330:
1.257 dtucker 3331: if (num_adm_permitted_opens > 0) {
3332: permit_adm = 0;
3333: for (i = 0; i < num_adm_permitted_opens; i++)
3334: if (permitted_adm_opens[i].host_to_connect != NULL &&
1.314 dtucker 3335: port_match(permitted_adm_opens[i].port_to_connect, port) &&
1.257 dtucker 3336: strcmp(permitted_adm_opens[i].host_to_connect, host)
3337: == 0)
3338: permit_adm = 1;
1.99 markus 3339: }
1.257 dtucker 3340:
3341: if (!permit || !permit_adm) {
1.188 itojun 3342: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3343: "but the request was denied.", host, port);
1.276 djm 3344: return NULL;
1.99 markus 3345: }
1.276 djm 3346: return connect_to(host, port, ctype, rname);
1.204 djm 3347: }
3348:
3349: void
3350: channel_send_window_changes(void)
3351: {
1.209 avsm 3352: u_int i;
1.204 djm 3353: struct winsize ws;
3354:
3355: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3356: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3357: channels[i]->type != SSH_CHANNEL_OPEN)
3358: continue;
3359: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3360: continue;
3361: channel_request_start(i, "window-change", 0);
1.238 deraadt 3362: packet_put_int((u_int)ws.ws_col);
3363: packet_put_int((u_int)ws.ws_row);
3364: packet_put_int((u_int)ws.ws_xpixel);
3365: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3366: packet_send();
3367: }
1.99 markus 3368: }
3369:
1.121 markus 3370: /* -- X11 forwarding */
1.1 deraadt 3371:
1.27 markus 3372: /*
3373: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3374: * Returns 0 and a suitable display number for the DISPLAY variable
3375: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3376: */
1.141 stevesk 3377: int
1.163 stevesk 3378: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3379: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3380: {
1.149 markus 3381: Channel *nc = NULL;
1.31 markus 3382: int display_number, sock;
3383: u_short port;
1.35 markus 3384: struct addrinfo hints, *ai, *aitop;
3385: char strport[NI_MAXSERV];
3386: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3387:
1.224 markus 3388: if (chanids == NULL)
3389: return -1;
3390:
1.33 markus 3391: for (display_number = x11_display_offset;
1.148 deraadt 3392: display_number < MAX_DISPLAYS;
3393: display_number++) {
1.25 markus 3394: port = 6000 + display_number;
1.35 markus 3395: memset(&hints, 0, sizeof(hints));
3396: hints.ai_family = IPv4or6;
1.163 stevesk 3397: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3398: hints.ai_socktype = SOCK_STREAM;
3399: snprintf(strport, sizeof strport, "%d", port);
3400: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3401: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3402: return -1;
1.25 markus 3403: }
1.35 markus 3404: for (ai = aitop; ai; ai = ai->ai_next) {
3405: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3406: continue;
1.300 dtucker 3407: sock = socket(ai->ai_family, ai->ai_socktype,
3408: ai->ai_protocol);
1.35 markus 3409: if (sock < 0) {
3410: error("socket: %.100s", strerror(errno));
1.203 markus 3411: freeaddrinfo(aitop);
1.141 stevesk 3412: return -1;
1.35 markus 3413: }
1.226 djm 3414: channel_set_reuseaddr(sock);
1.35 markus 3415: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3416: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3417: close(sock);
1.183 itojun 3418:
1.35 markus 3419: for (n = 0; n < num_socks; n++) {
3420: close(socks[n]);
3421: }
3422: num_socks = 0;
3423: break;
3424: }
3425: socks[num_socks++] = sock;
3426: if (num_socks == NUM_SOCKS)
3427: break;
1.25 markus 3428: }
1.83 stevesk 3429: freeaddrinfo(aitop);
1.35 markus 3430: if (num_socks > 0)
3431: break;
1.25 markus 3432: }
3433: if (display_number >= MAX_DISPLAYS) {
3434: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3435: return -1;
1.25 markus 3436: }
3437: /* Start listening for connections on the socket. */
1.35 markus 3438: for (n = 0; n < num_socks; n++) {
3439: sock = socks[n];
1.199 markus 3440: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3441: error("listen: %.100s", strerror(errno));
3442: close(sock);
1.141 stevesk 3443: return -1;
1.35 markus 3444: }
1.25 markus 3445: }
1.35 markus 3446:
3447: /* Allocate a channel for each socket. */
1.242 djm 3448: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3449: for (n = 0; n < num_socks; n++) {
3450: sock = socks[n];
1.149 markus 3451: nc = channel_new("x11 listener",
1.51 markus 3452: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3453: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3454: 0, "X11 inet listener", 1);
1.167 markus 3455: nc->single_connection = single_connection;
1.224 markus 3456: (*chanids)[n] = nc->self;
1.35 markus 3457: }
1.224 markus 3458: (*chanids)[n] = -1;
1.1 deraadt 3459:
1.141 stevesk 3460: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3461: *display_numberp = display_number;
3462: return (0);
1.1 deraadt 3463: }
3464:
1.127 itojun 3465: static int
1.77 markus 3466: connect_local_xsocket(u_int dnr)
1.1 deraadt 3467: {
1.25 markus 3468: int sock;
3469: struct sockaddr_un addr;
3470:
1.147 stevesk 3471: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3472: if (sock < 0)
3473: error("socket: %.100s", strerror(errno));
3474: memset(&addr, 0, sizeof(addr));
3475: addr.sun_family = AF_UNIX;
3476: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3477: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3478: return sock;
3479: close(sock);
1.25 markus 3480: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3481: return -1;
1.1 deraadt 3482: }
3483:
1.51 markus 3484: int
3485: x11_connect_display(void)
1.1 deraadt 3486: {
1.248 deraadt 3487: u_int display_number;
1.25 markus 3488: const char *display;
1.51 markus 3489: char buf[1024], *cp;
1.35 markus 3490: struct addrinfo hints, *ai, *aitop;
3491: char strport[NI_MAXSERV];
1.248 deraadt 3492: int gaierr, sock = 0;
1.25 markus 3493:
3494: /* Try to open a socket for the local X server. */
3495: display = getenv("DISPLAY");
3496: if (!display) {
3497: error("DISPLAY not set.");
1.51 markus 3498: return -1;
1.25 markus 3499: }
1.27 markus 3500: /*
3501: * Now we decode the value of the DISPLAY variable and make a
3502: * connection to the real X server.
3503: */
3504:
3505: /*
3506: * Check if it is a unix domain socket. Unix domain displays are in
3507: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3508: */
1.25 markus 3509: if (strncmp(display, "unix:", 5) == 0 ||
3510: display[0] == ':') {
3511: /* Connect to the unix domain socket. */
1.248 deraadt 3512: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3513: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3514: display);
1.51 markus 3515: return -1;
1.25 markus 3516: }
3517: /* Create a socket. */
3518: sock = connect_local_xsocket(display_number);
3519: if (sock < 0)
1.51 markus 3520: return -1;
1.25 markus 3521:
3522: /* OK, we now have a connection to the display. */
1.51 markus 3523: return sock;
1.25 markus 3524: }
1.27 markus 3525: /*
3526: * Connect to an inet socket. The DISPLAY value is supposedly
3527: * hostname:d[.s], where hostname may also be numeric IP address.
3528: */
1.145 stevesk 3529: strlcpy(buf, display, sizeof(buf));
1.25 markus 3530: cp = strchr(buf, ':');
3531: if (!cp) {
3532: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3533: return -1;
1.25 markus 3534: }
3535: *cp = 0;
1.27 markus 3536: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3537: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 3538: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3539: display);
1.51 markus 3540: return -1;
1.25 markus 3541: }
1.35 markus 3542:
3543: /* Look up the host address */
3544: memset(&hints, 0, sizeof(hints));
3545: hints.ai_family = IPv4or6;
3546: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3547: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3548: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3549: error("%.100s: unknown host. (%s)", buf,
3550: ssh_gai_strerror(gaierr));
1.51 markus 3551: return -1;
1.25 markus 3552: }
1.35 markus 3553: for (ai = aitop; ai; ai = ai->ai_next) {
3554: /* Create a socket. */
1.300 dtucker 3555: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3556: if (sock < 0) {
1.194 markus 3557: debug2("socket: %.100s", strerror(errno));
1.41 markus 3558: continue;
3559: }
3560: /* Connect it to the display. */
3561: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3562: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3563: 6000 + display_number, strerror(errno));
3564: close(sock);
3565: continue;
3566: }
3567: /* Success */
3568: break;
1.35 markus 3569: }
3570: freeaddrinfo(aitop);
3571: if (!ai) {
1.248 deraadt 3572: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3573: strerror(errno));
1.51 markus 3574: return -1;
1.25 markus 3575: }
1.162 stevesk 3576: set_nodelay(sock);
1.51 markus 3577: return sock;
3578: }
3579:
3580: /*
3581: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3582: * the remote channel number. We should do whatever we want, and respond
3583: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3584: */
3585:
1.259 stevesk 3586: /* ARGSUSED */
1.51 markus 3587: void
1.154 markus 3588: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3589: {
1.113 markus 3590: Channel *c = NULL;
3591: int remote_id, sock = 0;
1.51 markus 3592: char *remote_host;
1.25 markus 3593:
1.113 markus 3594: debug("Received X11 open request.");
1.51 markus 3595:
1.113 markus 3596: remote_id = packet_get_int();
1.121 markus 3597:
3598: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3599: remote_host = packet_get_string(NULL);
1.51 markus 3600: } else {
3601: remote_host = xstrdup("unknown (remote did not supply name)");
3602: }
1.152 markus 3603: packet_check_eom();
1.25 markus 3604:
1.51 markus 3605: /* Obtain a connection to the real X display. */
3606: sock = x11_connect_display();
1.113 markus 3607: if (sock != -1) {
3608: /* Allocate a channel for this connection. */
3609: c = channel_new("connected x11 socket",
3610: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3611: remote_host, 1);
1.167 markus 3612: c->remote_id = remote_id;
3613: c->force_drain = 1;
1.113 markus 3614: }
1.321 ! djm 3615: free(remote_host);
1.113 markus 3616: if (c == NULL) {
1.51 markus 3617: /* Send refusal to the remote host. */
3618: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3619: packet_put_int(remote_id);
1.51 markus 3620: } else {
3621: /* Send a confirmation to the remote host. */
3622: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3623: packet_put_int(remote_id);
3624: packet_put_int(c->self);
1.51 markus 3625: }
1.113 markus 3626: packet_send();
1.72 markus 3627: }
3628:
3629: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3630: /* ARGSUSED */
1.72 markus 3631: void
1.154 markus 3632: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3633: {
3634: int rchan = packet_get_int();
1.180 deraadt 3635:
1.143 deraadt 3636: switch (type) {
1.72 markus 3637: case SSH_SMSG_AGENT_OPEN:
3638: error("Warning: ssh server tried agent forwarding.");
3639: break;
3640: case SSH_SMSG_X11_OPEN:
3641: error("Warning: ssh server tried X11 forwarding.");
3642: break;
3643: default:
1.154 markus 3644: error("deny_input_open: type %d", type);
1.72 markus 3645: break;
3646: }
1.230 stevesk 3647: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3648: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3649: packet_put_int(rchan);
3650: packet_send();
1.1 deraadt 3651: }
3652:
1.27 markus 3653: /*
3654: * Requests forwarding of X11 connections, generates fake authentication
3655: * data, and enables authentication spoofing.
1.121 markus 3656: * This should be called in the client only.
1.27 markus 3657: */
1.49 markus 3658: void
1.215 djm 3659: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.311 djm 3660: const char *proto, const char *data, int want_reply)
1.1 deraadt 3661: {
1.77 markus 3662: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3663: u_int i, value;
1.25 markus 3664: char *new_data;
3665: int screen_number;
3666: const char *cp;
1.207 avsm 3667: u_int32_t rnd = 0;
1.25 markus 3668:
1.220 markus 3669: if (x11_saved_display == NULL)
3670: x11_saved_display = xstrdup(disp);
3671: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3672: error("x11_request_forwarding_with_spoofing: different "
3673: "$DISPLAY already forwarded");
3674: return;
3675: }
3676:
1.266 djm 3677: cp = strchr(disp, ':');
1.25 markus 3678: if (cp)
3679: cp = strchr(cp, '.');
3680: if (cp)
1.245 deraadt 3681: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3682: else
3683: screen_number = 0;
3684:
1.219 djm 3685: if (x11_saved_proto == NULL) {
3686: /* Save protocol name. */
3687: x11_saved_proto = xstrdup(proto);
3688: /*
1.221 djm 3689: * Extract real authentication data and generate fake data
1.219 djm 3690: * of the same length.
3691: */
3692: x11_saved_data = xmalloc(data_len);
3693: x11_fake_data = xmalloc(data_len);
3694: for (i = 0; i < data_len; i++) {
3695: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3696: fatal("x11_request_forwarding: bad "
3697: "authentication data: %.100s", data);
3698: if (i % 4 == 0)
3699: rnd = arc4random();
3700: x11_saved_data[i] = value;
3701: x11_fake_data[i] = rnd & 0xff;
3702: rnd >>= 8;
3703: }
3704: x11_saved_data_len = data_len;
3705: x11_fake_data_len = data_len;
1.25 markus 3706: }
3707:
3708: /* Convert the fake data into hex. */
1.219 djm 3709: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3710:
3711: /* Send the request packet. */
1.51 markus 3712: if (compat20) {
1.311 djm 3713: channel_request_start(client_session_id, "x11-req", want_reply);
1.51 markus 3714: packet_put_char(0); /* XXX bool single connection */
3715: } else {
3716: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3717: }
3718: packet_put_cstring(proto);
3719: packet_put_cstring(new_data);
1.25 markus 3720: packet_put_int(screen_number);
3721: packet_send();
3722: packet_write_wait();
1.321 ! djm 3723: free(new_data);
1.1 deraadt 3724: }
3725:
1.121 markus 3726:
3727: /* -- agent forwarding */
3728:
1.1 deraadt 3729: /* Sends a message to the server to request authentication fd forwarding. */
3730:
1.49 markus 3731: void
1.142 itojun 3732: auth_request_forwarding(void)
1.1 deraadt 3733: {
1.25 markus 3734: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3735: packet_send();
3736: packet_write_wait();
1.1 deraadt 3737: }
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