Annotation of src/usr.bin/ssh/channels.c, Revision 1.354
1.354 ! markus 1: /* $OpenBSD: channels.c,v 1.353 2016/09/19 07:52:42 natano 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>
1.336 millert 43: #include <sys/stat.h>
1.234 stevesk 44: #include <sys/ioctl.h>
1.235 stevesk 45: #include <sys/un.h>
1.251 stevesk 46: #include <sys/socket.h>
1.261 stevesk 47: #include <sys/time.h>
1.275 djm 48: #include <sys/queue.h>
1.251 stevesk 49:
50: #include <netinet/in.h>
51: #include <arpa/inet.h>
1.233 stevesk 52:
1.254 stevesk 53: #include <errno.h>
1.298 dtucker 54: #include <fcntl.h>
1.255 stevesk 55: #include <netdb.h>
1.341 millert 56: #include <stdint.h>
1.263 stevesk 57: #include <stdio.h>
1.262 stevesk 58: #include <stdlib.h>
1.260 stevesk 59: #include <string.h>
1.233 stevesk 60: #include <termios.h>
1.256 stevesk 61: #include <unistd.h>
1.265 deraadt 62: #include <stdarg.h>
1.1 deraadt 63:
1.265 deraadt 64: #include "xmalloc.h"
1.1 deraadt 65: #include "ssh.h"
1.82 markus 66: #include "ssh1.h"
67: #include "ssh2.h"
1.354 ! markus 68: #include "ssherr.h"
1.1 deraadt 69: #include "packet.h"
1.82 markus 70: #include "log.h"
71: #include "misc.h"
1.265 deraadt 72: #include "buffer.h"
1.14 markus 73: #include "channels.h"
74: #include "compat.h"
1.82 markus 75: #include "canohost.h"
1.64 markus 76: #include "key.h"
77: #include "authfd.h"
1.147 stevesk 78: #include "pathnames.h"
1.1 deraadt 79:
1.121 markus 80: /* -- channel core */
1.12 markus 81:
1.27 markus 82: /*
83: * Pointer to an array containing all allocated channels. The array is
84: * dynamically extended as needed.
85: */
1.113 markus 86: static Channel **channels = NULL;
1.1 deraadt 87:
1.27 markus 88: /*
89: * Size of the channel array. All slots of the array must always be
1.113 markus 90: * initialized (at least the type field); unused slots set to NULL
1.27 markus 91: */
1.209 avsm 92: static u_int channels_alloc = 0;
1.1 deraadt 93:
1.27 markus 94: /*
95: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 96: * updated in channel_new.
1.27 markus 97: */
1.84 markus 98: static int channel_max_fd = 0;
1.1 deraadt 99:
100:
1.121 markus 101: /* -- tcp forwarding */
1.1 deraadt 102:
1.27 markus 103: /*
104: * Data structure for storing which hosts are permitted for forward requests.
105: * The local sides of any remote forwards are stored in this array to prevent
106: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
107: * network (which might be behind a firewall).
108: */
1.336 millert 109: /* XXX: streamlocal wants a path instead of host:port */
110: /* Overload host_to_connect; we could just make this match Forward */
111: /* XXX - can we use listen_host instead of listen_path? */
1.25 markus 112: typedef struct {
1.41 markus 113: char *host_to_connect; /* Connect to 'host'. */
1.336 millert 114: int port_to_connect; /* Connect to 'port'. */
1.333 markus 115: char *listen_host; /* Remote side should listen address. */
1.336 millert 116: char *listen_path; /* Remote side should listen path. */
117: int listen_port; /* Remote side should listen port. */
1.354 ! markus 118: Channel *downstream; /* Downstream mux*/
1.1 deraadt 119: } ForwardPermission;
120:
1.257 dtucker 121: /* List of all permitted host/port pairs to connect by the user. */
1.305 djm 122: static ForwardPermission *permitted_opens = NULL;
1.121 markus 123:
1.257 dtucker 124: /* List of all permitted host/port pairs to connect by the admin. */
1.305 djm 125: static ForwardPermission *permitted_adm_opens = NULL;
1.257 dtucker 126:
127: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 128: static int num_permitted_opens = 0;
1.257 dtucker 129:
130: /* Number of permitted host/port pair in the array permitted by the admin. */
131: static int num_adm_permitted_opens = 0;
132:
1.314 dtucker 133: /* special-case port number meaning allow any port */
134: #define FWD_PERMIT_ANY_PORT 0
135:
1.351 dtucker 136: /* special-case wildcard meaning allow any host */
137: #define FWD_PERMIT_ANY_HOST "*"
138:
1.27 markus 139: /*
140: * If this is true, all opens are permitted. This is the case on the server
141: * on which we have to trust the client anyway, and the user could do
142: * anything after logging in anyway.
143: */
1.1 deraadt 144: static int all_opens_permitted = 0;
145:
1.121 markus 146:
147: /* -- X11 forwarding */
148:
149: /* Maximum number of fake X11 displays to try. */
150: #define MAX_DISPLAYS 1000
151:
1.219 djm 152: /* Saved X11 local (client) display. */
153: static char *x11_saved_display = NULL;
154:
1.121 markus 155: /* Saved X11 authentication protocol name. */
156: static char *x11_saved_proto = NULL;
157:
158: /* Saved X11 authentication data. This is the real data. */
159: static char *x11_saved_data = NULL;
160: static u_int x11_saved_data_len = 0;
161:
1.347 djm 162: /* Deadline after which all X11 connections are refused */
163: static u_int x11_refuse_time;
164:
1.121 markus 165: /*
166: * Fake X11 authentication data. This is what the server will be sending us;
167: * we should replace any occurrences of this by the real data.
168: */
1.240 deraadt 169: static u_char *x11_fake_data = NULL;
1.121 markus 170: static u_int x11_fake_data_len;
171:
172:
173: /* -- agent forwarding */
174:
175: #define NUM_SOCKS 10
176:
1.82 markus 177: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 178: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 179:
1.121 markus 180: /* helper */
1.127 itojun 181: static void port_open_helper(Channel *c, char *rtype);
1.354 ! markus 182: static const char *channel_rfwd_bind_host(const char *listen_host);
1.103 markus 183:
1.276 djm 184: /* non-blocking connect helpers */
185: static int connect_next(struct channel_connect *);
186: static void channel_connect_ctx_free(struct channel_connect *);
187:
1.121 markus 188: /* -- channel core */
1.41 markus 189:
190: Channel *
1.229 markus 191: channel_by_id(int id)
1.41 markus 192: {
193: Channel *c;
1.113 markus 194:
1.209 avsm 195: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 196: logit("channel_by_id: %d: bad id", id);
1.41 markus 197: return NULL;
198: }
1.113 markus 199: c = channels[id];
200: if (c == NULL) {
1.229 markus 201: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 202: return NULL;
203: }
204: return c;
1.55 markus 205: }
206:
1.354 ! markus 207: Channel *
! 208: channel_by_remote_id(int remote_id)
! 209: {
! 210: Channel *c;
! 211: u_int i;
! 212:
! 213: for (i = 0; i < channels_alloc; i++) {
! 214: c = channels[i];
! 215: if (c != NULL && c->remote_id == remote_id)
! 216: return c;
! 217: }
! 218: return NULL;
! 219: }
! 220:
1.27 markus 221: /*
1.229 markus 222: * Returns the channel if it is allowed to receive protocol messages.
223: * Private channels, like listening sockets, may not receive messages.
224: */
225: Channel *
226: channel_lookup(int id)
227: {
228: Channel *c;
229:
230: if ((c = channel_by_id(id)) == NULL)
231: return (NULL);
232:
1.237 deraadt 233: switch (c->type) {
1.229 markus 234: case SSH_CHANNEL_X11_OPEN:
235: case SSH_CHANNEL_LARVAL:
236: case SSH_CHANNEL_CONNECTING:
237: case SSH_CHANNEL_DYNAMIC:
238: case SSH_CHANNEL_OPENING:
239: case SSH_CHANNEL_OPEN:
240: case SSH_CHANNEL_INPUT_DRAINING:
241: case SSH_CHANNEL_OUTPUT_DRAINING:
1.323 dtucker 242: case SSH_CHANNEL_ABANDONED:
1.354 ! markus 243: case SSH_CHANNEL_MUX_PROXY:
1.229 markus 244: return (c);
245: }
246: logit("Non-public channel %d, type %d.", id, c->type);
247: return (NULL);
248: }
249:
250: /*
1.55 markus 251: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 252: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 253: */
1.127 itojun 254: static void
1.71 markus 255: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 256: int extusage, int nonblock, int is_tty)
1.1 deraadt 257: {
1.25 markus 258: /* Update the maximum file descriptor value. */
1.352 deraadt 259: channel_max_fd = MAXIMUM(channel_max_fd, rfd);
260: channel_max_fd = MAXIMUM(channel_max_fd, wfd);
261: channel_max_fd = MAXIMUM(channel_max_fd, efd);
1.84 markus 262:
1.298 dtucker 263: if (rfd != -1)
264: fcntl(rfd, F_SETFD, FD_CLOEXEC);
265: if (wfd != -1 && wfd != rfd)
266: fcntl(wfd, F_SETFD, FD_CLOEXEC);
267: if (efd != -1 && efd != rfd && efd != wfd)
268: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 269:
1.52 markus 270: c->rfd = rfd;
271: c->wfd = wfd;
272: c->sock = (rfd == wfd) ? rfd : -1;
273: c->efd = efd;
274: c->extended_usage = extusage;
1.71 markus 275:
1.282 dtucker 276: if ((c->isatty = is_tty) != 0)
1.194 markus 277: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 278:
1.71 markus 279: /* enable nonblocking mode */
280: if (nonblock) {
281: if (rfd != -1)
282: set_nonblock(rfd);
283: if (wfd != -1)
284: set_nonblock(wfd);
285: if (efd != -1)
286: set_nonblock(efd);
287: }
1.52 markus 288: }
289:
290: /*
291: * Allocate a new channel object and set its type and socket. This will cause
292: * remote_name to be freed.
293: */
1.113 markus 294: Channel *
1.52 markus 295: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 296: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 297: {
1.209 avsm 298: int found;
299: u_int i;
1.52 markus 300: Channel *c;
1.25 markus 301:
302: /* Do initial allocation if this is the first call. */
303: if (channels_alloc == 0) {
304: channels_alloc = 10;
1.242 djm 305: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 306: for (i = 0; i < channels_alloc; i++)
1.113 markus 307: channels[i] = NULL;
1.25 markus 308: }
309: /* Try to find a free slot where to put the new channel. */
310: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 311: if (channels[i] == NULL) {
1.25 markus 312: /* Found a free slot. */
1.209 avsm 313: found = (int)i;
1.25 markus 314: break;
315: }
1.209 avsm 316: if (found < 0) {
1.27 markus 317: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 318: found = channels_alloc;
1.179 markus 319: if (channels_alloc > 10000)
320: fatal("channel_new: internal error: channels_alloc %d "
321: "too big.", channels_alloc);
1.342 deraadt 322: channels = xreallocarray(channels, channels_alloc + 10,
1.243 djm 323: sizeof(Channel *));
1.195 markus 324: channels_alloc += 10;
1.70 markus 325: debug2("channel: expanding %d", channels_alloc);
1.25 markus 326: for (i = found; i < channels_alloc; i++)
1.113 markus 327: channels[i] = NULL;
1.25 markus 328: }
1.113 markus 329: /* Initialize and return new channel. */
1.242 djm 330: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 331: buffer_init(&c->input);
332: buffer_init(&c->output);
1.41 markus 333: buffer_init(&c->extended);
1.293 djm 334: c->path = NULL;
1.312 djm 335: c->listening_addr = NULL;
336: c->listening_port = 0;
1.159 markus 337: c->ostate = CHAN_OUTPUT_OPEN;
338: c->istate = CHAN_INPUT_OPEN;
339: c->flags = 0;
1.281 djm 340: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.317 djm 341: c->notbefore = 0;
1.25 markus 342: c->self = found;
343: c->type = type;
1.41 markus 344: c->ctype = ctype;
1.51 markus 345: c->local_window = window;
346: c->local_window_max = window;
347: c->local_consumed = 0;
348: c->local_maxpacket = maxpack;
1.25 markus 349: c->remote_id = -1;
1.190 markus 350: c->remote_name = xstrdup(remote_name);
1.41 markus 351: c->remote_window = 0;
352: c->remote_maxpacket = 0;
1.133 markus 353: c->force_drain = 0;
1.149 markus 354: c->single_connection = 0;
1.131 markus 355: c->detach_user = NULL;
1.225 djm 356: c->detach_close = 0;
1.275 djm 357: c->open_confirm = NULL;
358: c->open_confirm_ctx = NULL;
1.65 markus 359: c->input_filter = NULL;
1.231 reyk 360: c->output_filter = NULL;
1.280 djm 361: c->filter_ctx = NULL;
362: c->filter_cleanup = NULL;
1.302 djm 363: c->ctl_chan = -1;
364: c->mux_rcb = NULL;
365: c->mux_ctx = NULL;
1.304 djm 366: c->mux_pause = 0;
1.299 markus 367: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 368: TAILQ_INIT(&c->status_confirms);
1.25 markus 369: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 370: return c;
1.1 deraadt 371: }
1.52 markus 372:
1.132 markus 373: static int
374: channel_find_maxfd(void)
375: {
1.209 avsm 376: u_int i;
377: int max = 0;
1.132 markus 378: Channel *c;
379:
380: for (i = 0; i < channels_alloc; i++) {
381: c = channels[i];
382: if (c != NULL) {
1.352 deraadt 383: max = MAXIMUM(max, c->rfd);
384: max = MAXIMUM(max, c->wfd);
385: max = MAXIMUM(max, c->efd);
1.132 markus 386: }
387: }
388: return max;
389: }
390:
391: int
392: channel_close_fd(int *fdp)
393: {
394: int ret = 0, fd = *fdp;
395:
396: if (fd != -1) {
397: ret = close(fd);
398: *fdp = -1;
399: if (fd == channel_max_fd)
400: channel_max_fd = channel_find_maxfd();
401: }
402: return ret;
403: }
404:
1.52 markus 405: /* Close all channel fd/socket. */
1.127 itojun 406: static void
1.52 markus 407: channel_close_fds(Channel *c)
408: {
1.132 markus 409: channel_close_fd(&c->sock);
410: channel_close_fd(&c->rfd);
411: channel_close_fd(&c->wfd);
412: channel_close_fd(&c->efd);
1.121 markus 413: }
414:
415: /* Free the channel and close its fd/socket. */
416: void
417: channel_free(Channel *c)
418: {
419: char *s;
1.209 avsm 420: u_int i, n;
1.354 ! markus 421: Channel *other;
1.275 djm 422: struct channel_confirm *cc;
1.121 markus 423:
1.354 ! markus 424: for (n = 0, i = 0; i < channels_alloc; i++) {
! 425: if ((other = channels[i]) != NULL) {
1.121 markus 426: n++;
1.354 ! markus 427:
! 428: /* detach from mux client and prepare for closing */
! 429: if (c->type == SSH_CHANNEL_MUX_CLIENT &&
! 430: other->type == SSH_CHANNEL_MUX_PROXY &&
! 431: other->mux_ctx == c) {
! 432: other->mux_ctx = NULL;
! 433: other->type = SSH_CHANNEL_OPEN;
! 434: other->istate = CHAN_INPUT_CLOSED;
! 435: other->ostate = CHAN_OUTPUT_CLOSED;
! 436: }
! 437: }
! 438: }
1.209 avsm 439: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 440: c->remote_name ? c->remote_name : "???", n);
441:
1.354 ! markus 442: /* XXX more MUX cleanup: remove remote forwardings */
! 443: if (c->type == SSH_CHANNEL_MUX_CLIENT) {
! 444: for (i = 0; i < (u_int)num_permitted_opens; i++) {
! 445: if (permitted_opens[i].downstream != c)
! 446: continue;
! 447: /* cancel on the server, since mux client is gone */
! 448: debug("channel %d: cleanup remote forward for %s:%u",
! 449: c->self,
! 450: permitted_opens[i].listen_host,
! 451: permitted_opens[i].listen_port);
! 452: packet_start(SSH2_MSG_GLOBAL_REQUEST);
! 453: packet_put_cstring("cancel-tcpip-forward");
! 454: packet_put_char(0);
! 455: packet_put_cstring(channel_rfwd_bind_host(
! 456: permitted_opens[i].listen_host));
! 457: packet_put_int(permitted_opens[i].listen_port);
! 458: packet_send();
! 459: /* unregister */
! 460: permitted_opens[i].listen_port = 0;
! 461: permitted_opens[i].port_to_connect = 0;
! 462: free(permitted_opens[i].host_to_connect);
! 463: permitted_opens[i].host_to_connect = NULL;
! 464: free(permitted_opens[i].listen_host);
! 465: permitted_opens[i].listen_host = NULL;
! 466: permitted_opens[i].listen_path = NULL;
! 467: permitted_opens[i].downstream = NULL;
! 468: }
! 469: }
! 470:
1.121 markus 471: s = channel_open_message();
1.194 markus 472: debug3("channel %d: status: %s", c->self, s);
1.321 djm 473: free(s);
1.121 markus 474:
475: if (c->sock != -1)
476: shutdown(c->sock, SHUT_RDWR);
477: channel_close_fds(c);
478: buffer_free(&c->input);
479: buffer_free(&c->output);
480: buffer_free(&c->extended);
1.321 djm 481: free(c->remote_name);
482: c->remote_name = NULL;
483: free(c->path);
484: c->path = NULL;
485: free(c->listening_addr);
486: c->listening_addr = NULL;
1.275 djm 487: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
488: if (cc->abandon_cb != NULL)
489: cc->abandon_cb(c, cc->ctx);
490: TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.329 tedu 491: explicit_bzero(cc, sizeof(*cc));
1.321 djm 492: free(cc);
1.275 djm 493: }
1.280 djm 494: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
495: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 496: channels[c->self] = NULL;
1.321 djm 497: free(c);
1.121 markus 498: }
499:
500: void
1.126 markus 501: channel_free_all(void)
1.121 markus 502: {
1.209 avsm 503: u_int i;
1.121 markus 504:
1.126 markus 505: for (i = 0; i < channels_alloc; i++)
506: if (channels[i] != NULL)
507: channel_free(channels[i]);
1.131 markus 508: }
509:
1.121 markus 510: /*
511: * Closes the sockets/fds of all channels. This is used to close extra file
512: * descriptors after a fork.
513: */
514: void
1.142 itojun 515: channel_close_all(void)
1.121 markus 516: {
1.209 avsm 517: u_int i;
1.121 markus 518:
519: for (i = 0; i < channels_alloc; i++)
520: if (channels[i] != NULL)
521: channel_close_fds(channels[i]);
522: }
523:
524: /*
1.131 markus 525: * Stop listening to channels.
526: */
527: void
528: channel_stop_listening(void)
529: {
1.209 avsm 530: u_int i;
1.131 markus 531: Channel *c;
532:
533: for (i = 0; i < channels_alloc; i++) {
534: c = channels[i];
535: if (c != NULL) {
536: switch (c->type) {
537: case SSH_CHANNEL_AUTH_SOCKET:
538: case SSH_CHANNEL_PORT_LISTENER:
539: case SSH_CHANNEL_RPORT_LISTENER:
540: case SSH_CHANNEL_X11_LISTENER:
1.336 millert 541: case SSH_CHANNEL_UNIX_LISTENER:
542: case SSH_CHANNEL_RUNIX_LISTENER:
1.132 markus 543: channel_close_fd(&c->sock);
1.131 markus 544: channel_free(c);
545: break;
546: }
547: }
548: }
549: }
550:
551: /*
1.121 markus 552: * Returns true if no channel has too much buffered data, and false if one or
553: * more channel is overfull.
554: */
555: int
1.142 itojun 556: channel_not_very_much_buffered_data(void)
1.121 markus 557: {
558: u_int i;
559: Channel *c;
560:
561: for (i = 0; i < channels_alloc; i++) {
562: c = channels[i];
563: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 564: #if 0
565: if (!compat20 &&
566: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 567: debug2("channel %d: big input buffer %d",
1.121 markus 568: c->self, buffer_len(&c->input));
569: return 0;
570: }
1.136 markus 571: #endif
1.121 markus 572: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 573: debug2("channel %d: big output buffer %u > %u",
1.136 markus 574: c->self, buffer_len(&c->output),
575: packet_get_maxsize());
1.121 markus 576: return 0;
577: }
578: }
579: }
580: return 1;
581: }
582:
583: /* Returns true if any channel is still open. */
584: int
1.142 itojun 585: channel_still_open(void)
1.121 markus 586: {
1.209 avsm 587: u_int i;
1.121 markus 588: Channel *c;
589:
590: for (i = 0; i < channels_alloc; i++) {
591: c = channels[i];
592: if (c == NULL)
593: continue;
594: switch (c->type) {
595: case SSH_CHANNEL_X11_LISTENER:
596: case SSH_CHANNEL_PORT_LISTENER:
597: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 598: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 599: case SSH_CHANNEL_CLOSED:
600: case SSH_CHANNEL_AUTH_SOCKET:
601: case SSH_CHANNEL_DYNAMIC:
602: case SSH_CHANNEL_CONNECTING:
603: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 604: case SSH_CHANNEL_ABANDONED:
1.336 millert 605: case SSH_CHANNEL_UNIX_LISTENER:
606: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 607: continue;
608: case SSH_CHANNEL_LARVAL:
609: if (!compat20)
610: fatal("cannot happen: SSH_CHANNEL_LARVAL");
611: continue;
612: case SSH_CHANNEL_OPENING:
613: case SSH_CHANNEL_OPEN:
614: case SSH_CHANNEL_X11_OPEN:
1.302 djm 615: case SSH_CHANNEL_MUX_CLIENT:
1.354 ! markus 616: case SSH_CHANNEL_MUX_PROXY:
1.121 markus 617: return 1;
618: case SSH_CHANNEL_INPUT_DRAINING:
619: case SSH_CHANNEL_OUTPUT_DRAINING:
620: if (!compat13)
621: fatal("cannot happen: OUT_DRAIN");
622: return 1;
623: default:
624: fatal("channel_still_open: bad channel type %d", c->type);
625: /* NOTREACHED */
626: }
627: }
628: return 0;
629: }
630:
631: /* Returns the id of an open channel suitable for keepaliving */
632: int
1.142 itojun 633: channel_find_open(void)
1.121 markus 634: {
1.209 avsm 635: u_int i;
1.121 markus 636: Channel *c;
637:
638: for (i = 0; i < channels_alloc; i++) {
639: c = channels[i];
1.206 djm 640: if (c == NULL || c->remote_id < 0)
1.121 markus 641: continue;
642: switch (c->type) {
643: case SSH_CHANNEL_CLOSED:
644: case SSH_CHANNEL_DYNAMIC:
645: case SSH_CHANNEL_X11_LISTENER:
646: case SSH_CHANNEL_PORT_LISTENER:
647: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 648: case SSH_CHANNEL_MUX_LISTENER:
649: case SSH_CHANNEL_MUX_CLIENT:
1.354 ! markus 650: case SSH_CHANNEL_MUX_PROXY:
1.121 markus 651: case SSH_CHANNEL_OPENING:
652: case SSH_CHANNEL_CONNECTING:
653: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 654: case SSH_CHANNEL_ABANDONED:
1.336 millert 655: case SSH_CHANNEL_UNIX_LISTENER:
656: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 657: continue;
658: case SSH_CHANNEL_LARVAL:
659: case SSH_CHANNEL_AUTH_SOCKET:
660: case SSH_CHANNEL_OPEN:
661: case SSH_CHANNEL_X11_OPEN:
662: return i;
663: case SSH_CHANNEL_INPUT_DRAINING:
664: case SSH_CHANNEL_OUTPUT_DRAINING:
665: if (!compat13)
666: fatal("cannot happen: OUT_DRAIN");
667: return i;
668: default:
669: fatal("channel_find_open: bad channel type %d", c->type);
670: /* NOTREACHED */
671: }
672: }
673: return -1;
674: }
675:
676: /*
677: * Returns a message describing the currently open forwarded connections,
678: * suitable for sending to the client. The message contains crlf pairs for
679: * newlines.
680: */
681: char *
1.142 itojun 682: channel_open_message(void)
1.121 markus 683: {
684: Buffer buffer;
685: Channel *c;
686: char buf[1024], *cp;
1.209 avsm 687: u_int i;
1.121 markus 688:
689: buffer_init(&buffer);
690: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
691: buffer_append(&buffer, buf, strlen(buf));
692: for (i = 0; i < channels_alloc; i++) {
693: c = channels[i];
694: if (c == NULL)
695: continue;
696: switch (c->type) {
697: case SSH_CHANNEL_X11_LISTENER:
698: case SSH_CHANNEL_PORT_LISTENER:
699: case SSH_CHANNEL_RPORT_LISTENER:
700: case SSH_CHANNEL_CLOSED:
701: case SSH_CHANNEL_AUTH_SOCKET:
702: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 703: case SSH_CHANNEL_ABANDONED:
1.302 djm 704: case SSH_CHANNEL_MUX_LISTENER:
1.336 millert 705: case SSH_CHANNEL_UNIX_LISTENER:
706: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 707: continue;
708: case SSH_CHANNEL_LARVAL:
709: case SSH_CHANNEL_OPENING:
710: case SSH_CHANNEL_CONNECTING:
711: case SSH_CHANNEL_DYNAMIC:
712: case SSH_CHANNEL_OPEN:
713: case SSH_CHANNEL_X11_OPEN:
714: case SSH_CHANNEL_INPUT_DRAINING:
715: case SSH_CHANNEL_OUTPUT_DRAINING:
1.354 ! markus 716: case SSH_CHANNEL_MUX_PROXY:
! 717: case SSH_CHANNEL_MUX_CLIENT:
1.204 djm 718: snprintf(buf, sizeof buf,
1.348 djm 719: " #%d %.300s (t%d r%d i%u/%d o%u/%d fd %d/%d cc %d)\r\n",
1.121 markus 720: c->self, c->remote_name,
721: c->type, c->remote_id,
722: c->istate, buffer_len(&c->input),
723: c->ostate, buffer_len(&c->output),
1.302 djm 724: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 725: buffer_append(&buffer, buf, strlen(buf));
726: continue;
727: default:
728: fatal("channel_open_message: bad channel type %d", c->type);
729: /* NOTREACHED */
730: }
731: }
732: buffer_append(&buffer, "\0", 1);
1.337 djm 733: cp = xstrdup((char *)buffer_ptr(&buffer));
1.121 markus 734: buffer_free(&buffer);
735: return cp;
736: }
737:
738: void
739: channel_send_open(int id)
740: {
741: Channel *c = channel_lookup(id);
1.180 deraadt 742:
1.121 markus 743: if (c == NULL) {
1.188 itojun 744: logit("channel_send_open: %d: bad id", id);
1.121 markus 745: return;
746: }
1.184 markus 747: debug2("channel %d: send open", id);
1.121 markus 748: packet_start(SSH2_MSG_CHANNEL_OPEN);
749: packet_put_cstring(c->ctype);
750: packet_put_int(c->self);
751: packet_put_int(c->local_window);
752: packet_put_int(c->local_maxpacket);
753: packet_send();
754: }
755:
756: void
1.184 markus 757: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 758: {
1.184 markus 759: Channel *c = channel_lookup(id);
1.180 deraadt 760:
1.121 markus 761: if (c == NULL) {
1.188 itojun 762: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 763: return;
764: }
1.204 djm 765: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 766: packet_start(SSH2_MSG_CHANNEL_REQUEST);
767: packet_put_int(c->remote_id);
768: packet_put_cstring(service);
769: packet_put_char(wantconfirm);
770: }
1.241 deraadt 771:
1.121 markus 772: void
1.275 djm 773: channel_register_status_confirm(int id, channel_confirm_cb *cb,
774: channel_confirm_abandon_cb *abandon_cb, void *ctx)
775: {
776: struct channel_confirm *cc;
777: Channel *c;
778:
779: if ((c = channel_lookup(id)) == NULL)
780: fatal("channel_register_expect: %d: bad id", id);
781:
1.327 djm 782: cc = xcalloc(1, sizeof(*cc));
1.275 djm 783: cc->cb = cb;
784: cc->abandon_cb = abandon_cb;
785: cc->ctx = ctx;
786: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
787: }
788:
789: void
1.304 djm 790: channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
1.121 markus 791: {
792: Channel *c = channel_lookup(id);
1.180 deraadt 793:
1.121 markus 794: if (c == NULL) {
1.287 stevesk 795: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 796: return;
797: }
1.275 djm 798: c->open_confirm = fn;
799: c->open_confirm_ctx = ctx;
1.121 markus 800: }
1.241 deraadt 801:
1.121 markus 802: void
1.225 djm 803: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 804: {
1.229 markus 805: Channel *c = channel_by_id(id);
1.180 deraadt 806:
1.121 markus 807: if (c == NULL) {
1.188 itojun 808: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 809: return;
810: }
1.131 markus 811: c->detach_user = fn;
1.225 djm 812: c->detach_close = do_close;
1.121 markus 813: }
1.241 deraadt 814:
1.121 markus 815: void
816: channel_cancel_cleanup(int id)
817: {
1.229 markus 818: Channel *c = channel_by_id(id);
1.180 deraadt 819:
1.121 markus 820: if (c == NULL) {
1.188 itojun 821: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 822: return;
1.52 markus 823: }
1.131 markus 824: c->detach_user = NULL;
1.225 djm 825: c->detach_close = 0;
1.121 markus 826: }
1.241 deraadt 827:
1.121 markus 828: void
1.231 reyk 829: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 830: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 831: {
832: Channel *c = channel_lookup(id);
1.180 deraadt 833:
1.121 markus 834: if (c == NULL) {
1.188 itojun 835: logit("channel_register_filter: %d: bad id", id);
1.121 markus 836: return;
1.52 markus 837: }
1.231 reyk 838: c->input_filter = ifn;
839: c->output_filter = ofn;
1.279 djm 840: c->filter_ctx = ctx;
1.280 djm 841: c->filter_cleanup = cfn;
1.52 markus 842: }
843:
1.49 markus 844: void
1.121 markus 845: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 846: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 847: {
1.121 markus 848: Channel *c = channel_lookup(id);
1.180 deraadt 849:
1.121 markus 850: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
851: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 852: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 853: c->type = SSH_CHANNEL_OPEN;
1.168 markus 854: c->local_window = c->local_window_max = window_max;
1.121 markus 855: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
856: packet_put_int(c->remote_id);
857: packet_put_int(c->local_window);
858: packet_send();
1.1 deraadt 859: }
860:
1.27 markus 861: /*
1.41 markus 862: * 'channel_pre*' are called just before select() to add any bits relevant to
863: * channels in the select bitmasks.
864: */
865: /*
866: * 'channel_post*': perform any appropriate operations for channels which
867: * have events pending.
1.27 markus 868: */
1.237 deraadt 869: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 870: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
871: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
872:
1.259 stevesk 873: /* ARGSUSED */
1.127 itojun 874: static void
1.237 deraadt 875: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 876: {
877: FD_SET(c->sock, readset);
878: }
879:
1.259 stevesk 880: /* ARGSUSED */
1.127 itojun 881: static void
1.237 deraadt 882: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 883: {
884: debug3("channel %d: waiting for connection", c->self);
885: FD_SET(c->sock, writeset);
886: }
887:
1.127 itojun 888: static void
1.237 deraadt 889: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 890: {
891: if (buffer_len(&c->input) < packet_get_maxsize())
892: FD_SET(c->sock, readset);
893: if (buffer_len(&c->output) > 0)
894: FD_SET(c->sock, writeset);
895: }
1.1 deraadt 896:
1.127 itojun 897: static void
1.237 deraadt 898: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 899: {
1.157 markus 900: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 901:
1.44 markus 902: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 903: limit > 0 &&
1.250 djm 904: buffer_len(&c->input) < limit &&
905: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 906: FD_SET(c->rfd, readset);
907: if (c->ostate == CHAN_OUTPUT_OPEN ||
908: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
909: if (buffer_len(&c->output) > 0) {
910: FD_SET(c->wfd, writeset);
911: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 912: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 913: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
914: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 915: else
916: chan_obuf_empty(c);
1.44 markus 917: }
918: }
919: /** XXX check close conditions, too */
1.277 markus 920: if (compat20 && c->efd != -1 &&
921: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 922: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
923: buffer_len(&c->extended) > 0)
924: FD_SET(c->efd, writeset);
1.306 djm 925: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
926: (c->extended_usage == CHAN_EXTENDED_READ ||
927: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 928: buffer_len(&c->extended) < c->remote_window)
929: FD_SET(c->efd, readset);
930: }
1.204 djm 931: /* XXX: What about efd? races? */
1.44 markus 932: }
933:
1.259 stevesk 934: /* ARGSUSED */
1.127 itojun 935: static void
1.237 deraadt 936: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 937: {
938: if (buffer_len(&c->input) == 0) {
939: packet_start(SSH_MSG_CHANNEL_CLOSE);
940: packet_put_int(c->remote_id);
941: packet_send();
942: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 943: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 944: }
945: }
946:
1.259 stevesk 947: /* ARGSUSED */
1.127 itojun 948: static void
1.237 deraadt 949: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 950: {
951: if (buffer_len(&c->output) == 0)
1.113 markus 952: chan_mark_dead(c);
1.49 markus 953: else
1.41 markus 954: FD_SET(c->sock, writeset);
955: }
956:
957: /*
958: * This is a special state for X11 authentication spoofing. An opened X11
959: * connection (when authentication spoofing is being done) remains in this
960: * state until the first packet has been completely read. The authentication
961: * data in that packet is then substituted by the real data if it matches the
962: * fake data, and the channel is put into normal mode.
1.51 markus 963: * XXX All this happens at the client side.
1.121 markus 964: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 965: */
1.127 itojun 966: static int
1.121 markus 967: x11_open_helper(Buffer *b)
1.1 deraadt 968: {
1.77 markus 969: u_char *ucp;
970: u_int proto_len, data_len;
1.25 markus 971:
1.347 djm 972: /* Is this being called after the refusal deadline? */
973: if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
974: verbose("Rejected X11 connection after ForwardX11Timeout "
975: "expired");
976: return -1;
977: }
978:
1.41 markus 979: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 980: if (buffer_len(b) < 12)
1.41 markus 981: return 0;
982:
983: /* Parse the lengths of variable-length fields. */
1.155 stevesk 984: ucp = buffer_ptr(b);
1.41 markus 985: if (ucp[0] == 0x42) { /* Byte order MSB first. */
986: proto_len = 256 * ucp[6] + ucp[7];
987: data_len = 256 * ucp[8] + ucp[9];
988: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
989: proto_len = ucp[6] + 256 * ucp[7];
990: data_len = ucp[8] + 256 * ucp[9];
991: } else {
1.194 markus 992: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 993: ucp[0]);
1.41 markus 994: return -1;
995: }
996:
997: /* Check if the whole packet is in buffer. */
1.121 markus 998: if (buffer_len(b) <
1.41 markus 999: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
1000: return 0;
1001:
1002: /* Check if authentication protocol matches. */
1003: if (proto_len != strlen(x11_saved_proto) ||
1004: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 1005: debug2("X11 connection uses different authentication protocol.");
1.41 markus 1006: return -1;
1007: }
1008: /* Check if authentication data matches our fake data. */
1009: if (data_len != x11_fake_data_len ||
1.308 djm 1010: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.41 markus 1011: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 1012: debug2("X11 auth data does not match fake data.");
1.41 markus 1013: return -1;
1014: }
1015: /* Check fake data length */
1016: if (x11_fake_data_len != x11_saved_data_len) {
1017: error("X11 fake_data_len %d != saved_data_len %d",
1018: x11_fake_data_len, x11_saved_data_len);
1019: return -1;
1020: }
1021: /*
1022: * Received authentication protocol and data match
1023: * our fake data. Substitute the fake data with real
1024: * data.
1025: */
1026: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
1027: x11_saved_data, x11_saved_data_len);
1028: return 1;
1029: }
1030:
1.127 itojun 1031: static void
1.237 deraadt 1032: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1033: {
1.121 markus 1034: int ret = x11_open_helper(&c->output);
1.180 deraadt 1035:
1.41 markus 1036: if (ret == 1) {
1037: /* Start normal processing for the channel. */
1038: c->type = SSH_CHANNEL_OPEN;
1.47 markus 1039: channel_pre_open_13(c, readset, writeset);
1.41 markus 1040: } else if (ret == -1) {
1041: /*
1042: * We have received an X11 connection that has bad
1043: * authentication information.
1044: */
1.188 itojun 1045: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 1046: buffer_clear(&c->input);
1047: buffer_clear(&c->output);
1.132 markus 1048: channel_close_fd(&c->sock);
1.41 markus 1049: c->sock = -1;
1050: c->type = SSH_CHANNEL_CLOSED;
1051: packet_start(SSH_MSG_CHANNEL_CLOSE);
1052: packet_put_int(c->remote_id);
1053: packet_send();
1054: }
1055: }
1.25 markus 1056:
1.127 itojun 1057: static void
1.237 deraadt 1058: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1059: {
1.121 markus 1060: int ret = x11_open_helper(&c->output);
1.133 markus 1061:
1062: /* c->force_drain = 1; */
1063:
1.41 markus 1064: if (ret == 1) {
1065: c->type = SSH_CHANNEL_OPEN;
1.157 markus 1066: channel_pre_open(c, readset, writeset);
1.41 markus 1067: } else if (ret == -1) {
1.188 itojun 1068: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 1069: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 1070: chan_read_failed(c);
1071: buffer_clear(&c->input);
1072: chan_ibuf_empty(c);
1073: buffer_clear(&c->output);
1074: /* for proto v1, the peer will send an IEOF */
1075: if (compat20)
1076: chan_write_failed(c);
1077: else
1078: c->type = SSH_CHANNEL_OPEN;
1.194 markus 1079: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 1080: }
1081: }
1.25 markus 1082:
1.302 djm 1083: static void
1084: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1085: {
1.304 djm 1086: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 1087: buffer_check_alloc(&c->input, CHAN_RBUF))
1088: FD_SET(c->rfd, readset);
1089: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1090: /* clear buffer immediately (discard any partial packet) */
1091: buffer_clear(&c->input);
1092: chan_ibuf_empty(c);
1093: /* Start output drain. XXX just kill chan? */
1094: chan_rcvd_oclose(c);
1095: }
1096: if (c->ostate == CHAN_OUTPUT_OPEN ||
1097: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1098: if (buffer_len(&c->output) > 0)
1099: FD_SET(c->wfd, writeset);
1100: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1101: chan_obuf_empty(c);
1102: }
1103: }
1104:
1.104 markus 1105: /* try to decode a socks4 header */
1.259 stevesk 1106: /* ARGSUSED */
1.127 itojun 1107: static int
1.237 deraadt 1108: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1109: {
1.181 markus 1110: char *p, *host;
1.292 djm 1111: u_int len, have, i, found, need;
1.148 deraadt 1112: char username[256];
1.103 markus 1113: struct {
1114: u_int8_t version;
1115: u_int8_t command;
1116: u_int16_t dest_port;
1.104 markus 1117: struct in_addr dest_addr;
1.103 markus 1118: } s4_req, s4_rsp;
1119:
1.104 markus 1120: debug2("channel %d: decode socks4", c->self);
1.109 markus 1121:
1122: have = buffer_len(&c->input);
1123: len = sizeof(s4_req);
1124: if (have < len)
1125: return 0;
1.337 djm 1126: p = (char *)buffer_ptr(&c->input);
1.292 djm 1127:
1128: need = 1;
1129: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1130: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1131: debug2("channel %d: socks4a request", c->self);
1132: /* ... and needs an extra string (the hostname) */
1133: need = 2;
1134: }
1135: /* Check for terminating NUL on the string(s) */
1.109 markus 1136: for (found = 0, i = len; i < have; i++) {
1137: if (p[i] == '\0') {
1.292 djm 1138: found++;
1139: if (found == need)
1140: break;
1.109 markus 1141: }
1142: if (i > 1024) {
1143: /* the peer is probably sending garbage */
1144: debug("channel %d: decode socks4: too long",
1145: c->self);
1146: return -1;
1147: }
1148: }
1.292 djm 1149: if (found < need)
1.109 markus 1150: return 0;
1.103 markus 1151: buffer_get(&c->input, (char *)&s4_req.version, 1);
1152: buffer_get(&c->input, (char *)&s4_req.command, 1);
1153: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1154: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1155: have = buffer_len(&c->input);
1.337 djm 1156: p = (char *)buffer_ptr(&c->input);
1.331 djm 1157: if (memchr(p, '\0', have) == NULL)
1158: fatal("channel %d: decode socks4: user not nul terminated",
1159: c->self);
1.103 markus 1160: len = strlen(p);
1.106 markus 1161: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1162: len++; /* trailing '\0' */
1.103 markus 1163: if (len > have)
1.104 markus 1164: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1165: c->self, len, have);
1166: strlcpy(username, p, sizeof(username));
1167: buffer_consume(&c->input, len);
1168:
1.321 djm 1169: free(c->path);
1170: c->path = NULL;
1.292 djm 1171: if (need == 1) { /* SOCKS4: one string */
1172: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1173: c->path = xstrdup(host);
1.292 djm 1174: } else { /* SOCKS4A: two strings */
1175: have = buffer_len(&c->input);
1.337 djm 1176: p = (char *)buffer_ptr(&c->input);
1.292 djm 1177: len = strlen(p);
1178: debug2("channel %d: decode socks4a: host %s/%d",
1179: c->self, p, len);
1180: len++; /* trailing '\0' */
1181: if (len > have)
1182: fatal("channel %d: decode socks4a: len %d > have %d",
1183: c->self, len, have);
1.293 djm 1184: if (len > NI_MAXHOST) {
1.292 djm 1185: error("channel %d: hostname \"%.100s\" too long",
1186: c->self, p);
1187: return -1;
1188: }
1.293 djm 1189: c->path = xstrdup(p);
1.292 djm 1190: buffer_consume(&c->input, len);
1191: }
1.103 markus 1192: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1193:
1.194 markus 1194: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1195: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1196:
1.104 markus 1197: if (s4_req.command != 1) {
1.292 djm 1198: debug("channel %d: cannot handle: %s cn %d",
1199: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1200: return -1;
1.103 markus 1201: }
1.104 markus 1202: s4_rsp.version = 0; /* vn: 0 for reply */
1203: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1204: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1205: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1206: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1207: return 1;
1208: }
1209:
1.193 markus 1210: /* try to decode a socks5 header */
1211: #define SSH_SOCKS5_AUTHDONE 0x1000
1212: #define SSH_SOCKS5_NOAUTH 0x00
1213: #define SSH_SOCKS5_IPV4 0x01
1214: #define SSH_SOCKS5_DOMAIN 0x03
1215: #define SSH_SOCKS5_IPV6 0x04
1216: #define SSH_SOCKS5_CONNECT 0x01
1217: #define SSH_SOCKS5_SUCCESS 0x00
1218:
1.259 stevesk 1219: /* ARGSUSED */
1.193 markus 1220: static int
1.237 deraadt 1221: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1222: {
1223: struct {
1224: u_int8_t version;
1225: u_int8_t command;
1226: u_int8_t reserved;
1227: u_int8_t atyp;
1228: } s5_req, s5_rsp;
1229: u_int16_t dest_port;
1.324 djm 1230: char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1231: u_char *p;
1.252 djm 1232: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1233:
1234: debug2("channel %d: decode socks5", c->self);
1235: p = buffer_ptr(&c->input);
1236: if (p[0] != 0x05)
1237: return -1;
1238: have = buffer_len(&c->input);
1239: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1240: /* format: ver | nmethods | methods */
1.198 djm 1241: if (have < 2)
1.193 markus 1242: return 0;
1243: nmethods = p[1];
1244: if (have < nmethods + 2)
1245: return 0;
1246: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1247: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1248: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1249: found = 1;
1250: break;
1251: }
1252: }
1253: if (!found) {
1254: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1255: c->self);
1256: return -1;
1257: }
1258: buffer_consume(&c->input, nmethods + 2);
1259: buffer_put_char(&c->output, 0x05); /* version */
1260: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1261: FD_SET(c->sock, writeset);
1262: c->flags |= SSH_SOCKS5_AUTHDONE;
1263: debug2("channel %d: socks5 auth done", c->self);
1264: return 0; /* need more */
1265: }
1266: debug2("channel %d: socks5 post auth", c->self);
1267: if (have < sizeof(s5_req)+1)
1268: return 0; /* need more */
1.247 deraadt 1269: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1270: if (s5_req.version != 0x05 ||
1271: s5_req.command != SSH_SOCKS5_CONNECT ||
1272: s5_req.reserved != 0x00) {
1.194 markus 1273: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1274: return -1;
1275: }
1.213 deraadt 1276: switch (s5_req.atyp){
1.193 markus 1277: case SSH_SOCKS5_IPV4:
1278: addrlen = 4;
1279: af = AF_INET;
1280: break;
1281: case SSH_SOCKS5_DOMAIN:
1282: addrlen = p[sizeof(s5_req)];
1283: af = -1;
1284: break;
1285: case SSH_SOCKS5_IPV6:
1286: addrlen = 16;
1287: af = AF_INET6;
1288: break;
1289: default:
1.194 markus 1290: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1291: return -1;
1292: }
1.252 djm 1293: need = sizeof(s5_req) + addrlen + 2;
1294: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1295: need++;
1296: if (have < need)
1.193 markus 1297: return 0;
1298: buffer_consume(&c->input, sizeof(s5_req));
1299: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1300: buffer_consume(&c->input, 1); /* host string length */
1.324 djm 1301: buffer_get(&c->input, &dest_addr, addrlen);
1.193 markus 1302: buffer_get(&c->input, (char *)&dest_port, 2);
1303: dest_addr[addrlen] = '\0';
1.321 djm 1304: free(c->path);
1305: c->path = NULL;
1.293 djm 1306: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1307: if (addrlen >= NI_MAXHOST) {
1.293 djm 1308: error("channel %d: dynamic request: socks5 hostname "
1309: "\"%.100s\" too long", c->self, dest_addr);
1310: return -1;
1311: }
1312: c->path = xstrdup(dest_addr);
1313: } else {
1314: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1315: return -1;
1316: c->path = xstrdup(ntop);
1317: }
1.193 markus 1318: c->host_port = ntohs(dest_port);
1.198 djm 1319:
1.194 markus 1320: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1321: c->self, c->path, c->host_port, s5_req.command);
1322:
1323: s5_rsp.version = 0x05;
1324: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1325: s5_rsp.reserved = 0; /* ignored */
1326: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1327: dest_port = 0; /* ignored */
1328:
1.246 deraadt 1329: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1.325 djm 1330: buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1.246 deraadt 1331: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1332: return 1;
1.301 dtucker 1333: }
1334:
1335: Channel *
1.302 djm 1336: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1337: int in, int out)
1.301 dtucker 1338: {
1339: Channel *c;
1340:
1341: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1342: port_to_connect);
1343:
1344: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1345: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1346: 0, "stdio-forward", /*nonblock*/0);
1347:
1348: c->path = xstrdup(host_to_connect);
1349: c->host_port = port_to_connect;
1350: c->listening_port = 0;
1351: c->force_drain = 1;
1352:
1353: channel_register_fds(c, in, out, -1, 0, 1, 0);
1354: port_open_helper(c, "direct-tcpip");
1355:
1356: return c;
1.193 markus 1357: }
1358:
1.104 markus 1359: /* dynamic port forwarding */
1.127 itojun 1360: static void
1.237 deraadt 1361: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1362: {
1363: u_char *p;
1.217 djm 1364: u_int have;
1365: int ret;
1.103 markus 1366:
1.104 markus 1367: have = buffer_len(&c->input);
1368: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1369: /* buffer_dump(&c->input); */
1.104 markus 1370: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1371: if (have < 3) {
1.104 markus 1372: /* need more */
1373: FD_SET(c->sock, readset);
1374: return;
1375: }
1376: /* try to guess the protocol */
1377: p = buffer_ptr(&c->input);
1378: switch (p[0]) {
1379: case 0x04:
1380: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1381: break;
1382: case 0x05:
1383: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1384: break;
1385: default:
1386: ret = -1;
1387: break;
1388: }
1389: if (ret < 0) {
1.113 markus 1390: chan_mark_dead(c);
1.104 markus 1391: } else if (ret == 0) {
1392: debug2("channel %d: pre_dynamic: need more", c->self);
1393: /* need more */
1394: FD_SET(c->sock, readset);
1395: } else {
1396: /* switch to the next state */
1397: c->type = SSH_CHANNEL_OPENING;
1398: port_open_helper(c, "direct-tcpip");
1399: }
1.103 markus 1400: }
1401:
1.41 markus 1402: /* This is our fake X11 server socket. */
1.259 stevesk 1403: /* ARGSUSED */
1.127 itojun 1404: static void
1.237 deraadt 1405: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1406: {
1.113 markus 1407: Channel *nc;
1.285 djm 1408: struct sockaddr_storage addr;
1.320 markus 1409: int newsock, oerrno;
1.41 markus 1410: socklen_t addrlen;
1.85 markus 1411: char buf[16384], *remote_ipaddr;
1.51 markus 1412: int remote_port;
1.25 markus 1413:
1.41 markus 1414: if (FD_ISSET(c->sock, readset)) {
1415: debug("X11 connection requested.");
1416: addrlen = sizeof(addr);
1.285 djm 1417: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1418: if (c->single_connection) {
1.320 markus 1419: oerrno = errno;
1.194 markus 1420: debug2("single_connection: closing X11 listener.");
1.149 markus 1421: channel_close_fd(&c->sock);
1422: chan_mark_dead(c);
1.320 markus 1423: errno = oerrno;
1.149 markus 1424: }
1.41 markus 1425: if (newsock < 0) {
1.320 markus 1426: if (errno != EINTR && errno != EWOULDBLOCK &&
1427: errno != ECONNABORTED)
1428: error("accept: %.100s", strerror(errno));
1.317 djm 1429: if (errno == EMFILE || errno == ENFILE)
1.322 dtucker 1430: c->notbefore = monotime() + 1;
1.41 markus 1431: return;
1432: }
1.162 stevesk 1433: set_nodelay(newsock);
1.85 markus 1434: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1435: remote_port = get_peer_port(newsock);
1.41 markus 1436: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1437: remote_ipaddr, remote_port);
1.51 markus 1438:
1.113 markus 1439: nc = channel_new("accepted x11 socket",
1.51 markus 1440: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1441: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1442: if (compat20) {
1443: packet_start(SSH2_MSG_CHANNEL_OPEN);
1444: packet_put_cstring("x11");
1.113 markus 1445: packet_put_int(nc->self);
1.149 markus 1446: packet_put_int(nc->local_window_max);
1447: packet_put_int(nc->local_maxpacket);
1.85 markus 1448: /* originator ipaddr and port */
1449: packet_put_cstring(remote_ipaddr);
1.57 markus 1450: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1451: debug2("ssh2 x11 bug compat mode");
1.57 markus 1452: } else {
1453: packet_put_int(remote_port);
1454: }
1.51 markus 1455: packet_send();
1456: } else {
1457: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1458: packet_put_int(nc->self);
1.121 markus 1459: if (packet_get_protocol_flags() &
1460: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1461: packet_put_cstring(buf);
1.51 markus 1462: packet_send();
1463: }
1.321 djm 1464: free(remote_ipaddr);
1.41 markus 1465: }
1466: }
1.25 markus 1467:
1.127 itojun 1468: static void
1.103 markus 1469: port_open_helper(Channel *c, char *rtype)
1470: {
1471: char buf[1024];
1.328 djm 1472: char *local_ipaddr = get_local_ipaddr(c->sock);
1.350 djm 1473: int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
1.103 markus 1474: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1475: int remote_port = get_peer_port(c->sock);
1.303 djm 1476:
1477: if (remote_port == -1) {
1478: /* Fake addr/port to appease peers that validate it (Tectia) */
1.321 djm 1479: free(remote_ipaddr);
1.303 djm 1480: remote_ipaddr = xstrdup("127.0.0.1");
1481: remote_port = 65535;
1482: }
1.103 markus 1483:
1484: snprintf(buf, sizeof buf,
1485: "%s: listening port %d for %.100s port %d, "
1.328 djm 1486: "connect from %.200s port %d to %.100s port %d",
1.103 markus 1487: rtype, c->listening_port, c->path, c->host_port,
1.328 djm 1488: remote_ipaddr, remote_port, local_ipaddr, local_port);
1.103 markus 1489:
1.321 djm 1490: free(c->remote_name);
1.103 markus 1491: c->remote_name = xstrdup(buf);
1492:
1493: if (compat20) {
1494: packet_start(SSH2_MSG_CHANNEL_OPEN);
1495: packet_put_cstring(rtype);
1496: packet_put_int(c->self);
1497: packet_put_int(c->local_window_max);
1498: packet_put_int(c->local_maxpacket);
1.336 millert 1499: if (strcmp(rtype, "direct-tcpip") == 0) {
1.103 markus 1500: /* target host, port */
1501: packet_put_cstring(c->path);
1502: packet_put_int(c->host_port);
1.336 millert 1503: } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1504: /* target path */
1505: packet_put_cstring(c->path);
1506: } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1507: /* listen path */
1508: packet_put_cstring(c->path);
1.103 markus 1509: } else {
1510: /* listen address, port */
1511: packet_put_cstring(c->path);
1.328 djm 1512: packet_put_int(local_port);
1.103 markus 1513: }
1.336 millert 1514: if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1515: /* reserved for future owner/mode info */
1516: packet_put_cstring("");
1517: } else {
1518: /* originator host and port */
1519: packet_put_cstring(remote_ipaddr);
1520: packet_put_int((u_int)remote_port);
1521: }
1.103 markus 1522: packet_send();
1523: } else {
1524: packet_start(SSH_MSG_PORT_OPEN);
1525: packet_put_int(c->self);
1526: packet_put_cstring(c->path);
1527: packet_put_int(c->host_port);
1.121 markus 1528: if (packet_get_protocol_flags() &
1529: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1530: packet_put_cstring(c->remote_name);
1531: packet_send();
1532: }
1.321 djm 1533: free(remote_ipaddr);
1.328 djm 1534: free(local_ipaddr);
1.103 markus 1535: }
1536:
1.226 djm 1537: static void
1538: channel_set_reuseaddr(int fd)
1539: {
1540: int on = 1;
1541:
1542: /*
1543: * Set socket options.
1544: * Allow local port reuse in TIME_WAIT.
1545: */
1546: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1547: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1.347 djm 1548: }
1549:
1550: void
1551: channel_set_x11_refuse_time(u_int refuse_time)
1552: {
1553: x11_refuse_time = refuse_time;
1.226 djm 1554: }
1555:
1.41 markus 1556: /*
1557: * This socket is listening for connections to a forwarded TCP/IP port.
1558: */
1.259 stevesk 1559: /* ARGSUSED */
1.127 itojun 1560: static void
1.237 deraadt 1561: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1562: {
1.103 markus 1563: Channel *nc;
1.285 djm 1564: struct sockaddr_storage addr;
1.113 markus 1565: int newsock, nextstate;
1.41 markus 1566: socklen_t addrlen;
1.103 markus 1567: char *rtype;
1.73 markus 1568:
1.41 markus 1569: if (FD_ISSET(c->sock, readset)) {
1570: debug("Connection to port %d forwarding "
1571: "to %.100s port %d requested.",
1572: c->listening_port, c->path, c->host_port);
1.103 markus 1573:
1.137 markus 1574: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1575: nextstate = SSH_CHANNEL_OPENING;
1576: rtype = "forwarded-tcpip";
1.336 millert 1577: } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1578: nextstate = SSH_CHANNEL_OPENING;
1579: rtype = "forwarded-streamlocal@openssh.com";
1580: } else if (c->host_port == PORT_STREAMLOCAL) {
1581: nextstate = SSH_CHANNEL_OPENING;
1582: rtype = "direct-streamlocal@openssh.com";
1583: } else if (c->host_port == 0) {
1584: nextstate = SSH_CHANNEL_DYNAMIC;
1585: rtype = "dynamic-tcpip";
1.137 markus 1586: } else {
1.336 millert 1587: nextstate = SSH_CHANNEL_OPENING;
1588: rtype = "direct-tcpip";
1.137 markus 1589: }
1.103 markus 1590:
1.41 markus 1591: addrlen = sizeof(addr);
1.285 djm 1592: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1593: if (newsock < 0) {
1.320 markus 1594: if (errno != EINTR && errno != EWOULDBLOCK &&
1595: errno != ECONNABORTED)
1596: error("accept: %.100s", strerror(errno));
1.317 djm 1597: if (errno == EMFILE || errno == ENFILE)
1.322 dtucker 1598: c->notbefore = monotime() + 1;
1.41 markus 1599: return;
1600: }
1.336 millert 1601: if (c->host_port != PORT_STREAMLOCAL)
1602: set_nodelay(newsock);
1.190 markus 1603: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1604: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1605: nc->listening_port = c->listening_port;
1606: nc->host_port = c->host_port;
1.293 djm 1607: if (c->path != NULL)
1608: nc->path = xstrdup(c->path);
1.103 markus 1609:
1.299 markus 1610: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1611: port_open_helper(nc, rtype);
1.41 markus 1612: }
1613: }
1.25 markus 1614:
1.41 markus 1615: /*
1616: * This is the authentication agent socket listening for connections from
1617: * clients.
1618: */
1.259 stevesk 1619: /* ARGSUSED */
1.127 itojun 1620: static void
1.237 deraadt 1621: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1622: {
1.113 markus 1623: Channel *nc;
1624: int newsock;
1.285 djm 1625: struct sockaddr_storage addr;
1.41 markus 1626: socklen_t addrlen;
1.25 markus 1627:
1.41 markus 1628: if (FD_ISSET(c->sock, readset)) {
1629: addrlen = sizeof(addr);
1.285 djm 1630: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1631: if (newsock < 0) {
1.317 djm 1632: error("accept from auth socket: %.100s",
1633: strerror(errno));
1634: if (errno == EMFILE || errno == ENFILE)
1.322 dtucker 1635: c->notbefore = monotime() + 1;
1.41 markus 1636: return;
1637: }
1.113 markus 1638: nc = channel_new("accepted auth socket",
1.73 markus 1639: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1640: c->local_window_max, c->local_maxpacket,
1.190 markus 1641: 0, "accepted auth socket", 1);
1.73 markus 1642: if (compat20) {
1643: packet_start(SSH2_MSG_CHANNEL_OPEN);
1644: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1645: packet_put_int(nc->self);
1.73 markus 1646: packet_put_int(c->local_window_max);
1647: packet_put_int(c->local_maxpacket);
1648: } else {
1649: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1650: packet_put_int(nc->self);
1.73 markus 1651: }
1.41 markus 1652: packet_send();
1653: }
1654: }
1.25 markus 1655:
1.259 stevesk 1656: /* ARGSUSED */
1.127 itojun 1657: static void
1.237 deraadt 1658: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1659: {
1.276 djm 1660: int err = 0, sock;
1.129 stevesk 1661: socklen_t sz = sizeof(err);
1.114 markus 1662:
1.75 markus 1663: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1664: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1665: err = errno;
1666: error("getsockopt SO_ERROR failed");
1667: }
1668: if (err == 0) {
1.276 djm 1669: debug("channel %d: connected to %s port %d",
1670: c->self, c->connect_ctx.host, c->connect_ctx.port);
1671: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1672: c->type = SSH_CHANNEL_OPEN;
1673: if (compat20) {
1674: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1675: packet_put_int(c->remote_id);
1676: packet_put_int(c->self);
1677: packet_put_int(c->local_window);
1678: packet_put_int(c->local_maxpacket);
1679: } else {
1680: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1681: packet_put_int(c->remote_id);
1682: packet_put_int(c->self);
1683: }
1.75 markus 1684: } else {
1.276 djm 1685: debug("channel %d: connection failed: %s",
1.114 markus 1686: c->self, strerror(err));
1.276 djm 1687: /* Try next address, if any */
1688: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1689: close(c->sock);
1690: c->sock = c->rfd = c->wfd = sock;
1691: channel_max_fd = channel_find_maxfd();
1692: return;
1693: }
1694: /* Exhausted all addresses */
1695: error("connect_to %.100s port %d: failed.",
1696: c->connect_ctx.host, c->connect_ctx.port);
1697: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1698: if (compat20) {
1699: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1700: packet_put_int(c->remote_id);
1701: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1702: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1703: packet_put_cstring(strerror(err));
1704: packet_put_cstring("");
1705: }
1.75 markus 1706: } else {
1.114 markus 1707: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1708: packet_put_int(c->remote_id);
1.75 markus 1709: }
1.114 markus 1710: chan_mark_dead(c);
1.75 markus 1711: }
1.114 markus 1712: packet_send();
1.75 markus 1713: }
1714: }
1715:
1.259 stevesk 1716: /* ARGSUSED */
1.127 itojun 1717: static int
1.237 deraadt 1718: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1719: {
1.214 markus 1720: char buf[CHAN_RBUF];
1.41 markus 1721: int len;
1.25 markus 1722:
1.118 markus 1723: if (c->rfd != -1 &&
1.41 markus 1724: FD_ISSET(c->rfd, readset)) {
1725: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1726: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1727: return 1;
1.41 markus 1728: if (len <= 0) {
1.194 markus 1729: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1730: c->self, c->rfd, len);
1.104 markus 1731: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1732: debug2("channel %d: not open", c->self);
1.113 markus 1733: chan_mark_dead(c);
1.103 markus 1734: return -1;
1.104 markus 1735: } else if (compat13) {
1.158 markus 1736: buffer_clear(&c->output);
1.41 markus 1737: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1738: debug2("channel %d: input draining.", c->self);
1.25 markus 1739: } else {
1.41 markus 1740: chan_read_failed(c);
1.25 markus 1741: }
1.41 markus 1742: return -1;
1743: }
1.143 deraadt 1744: if (c->input_filter != NULL) {
1.66 markus 1745: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1746: debug2("channel %d: filter stops", c->self);
1.65 markus 1747: chan_read_failed(c);
1748: }
1.228 reyk 1749: } else if (c->datagram) {
1750: buffer_put_string(&c->input, buf, len);
1.65 markus 1751: } else {
1752: buffer_append(&c->input, buf, len);
1753: }
1.41 markus 1754: }
1755: return 1;
1756: }
1.241 deraadt 1757:
1.259 stevesk 1758: /* ARGSUSED */
1.127 itojun 1759: static int
1.237 deraadt 1760: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1761: {
1.95 markus 1762: struct termios tio;
1.231 reyk 1763: u_char *data = NULL, *buf;
1.309 djm 1764: u_int dlen, olen = 0;
1.41 markus 1765: int len;
1.25 markus 1766:
1.41 markus 1767: /* Send buffered output data to the socket. */
1.118 markus 1768: if (c->wfd != -1 &&
1.41 markus 1769: FD_ISSET(c->wfd, writeset) &&
1770: buffer_len(&c->output) > 0) {
1.309 djm 1771: olen = buffer_len(&c->output);
1.231 reyk 1772: if (c->output_filter != NULL) {
1773: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1774: debug2("channel %d: filter stops", c->self);
1.232 reyk 1775: if (c->type != SSH_CHANNEL_OPEN)
1776: chan_mark_dead(c);
1777: else
1778: chan_write_failed(c);
1779: return -1;
1.231 reyk 1780: }
1781: } else if (c->datagram) {
1782: buf = data = buffer_get_string(&c->output, &dlen);
1783: } else {
1784: buf = data = buffer_ptr(&c->output);
1785: dlen = buffer_len(&c->output);
1786: }
1787:
1.228 reyk 1788: if (c->datagram) {
1789: /* ignore truncated writes, datagrams might get lost */
1.231 reyk 1790: len = write(c->wfd, buf, dlen);
1.321 djm 1791: free(data);
1.228 reyk 1792: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1793: return 1;
1794: if (len <= 0) {
1795: if (c->type != SSH_CHANNEL_OPEN)
1796: chan_mark_dead(c);
1797: else
1798: chan_write_failed(c);
1799: return -1;
1800: }
1.309 djm 1801: goto out;
1.228 reyk 1802: }
1.231 reyk 1803:
1804: len = write(c->wfd, buf, dlen);
1.53 markus 1805: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1806: return 1;
1.41 markus 1807: if (len <= 0) {
1.104 markus 1808: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1809: debug2("channel %d: not open", c->self);
1.113 markus 1810: chan_mark_dead(c);
1.104 markus 1811: return -1;
1812: } else if (compat13) {
1.158 markus 1813: buffer_clear(&c->output);
1.194 markus 1814: debug2("channel %d: input draining.", c->self);
1.41 markus 1815: c->type = SSH_CHANNEL_INPUT_DRAINING;
1816: } else {
1817: chan_write_failed(c);
1818: }
1819: return -1;
1.91 markus 1820: }
1.231 reyk 1821: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1822: if (tcgetattr(c->wfd, &tio) == 0 &&
1823: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1824: /*
1825: * Simulate echo to reduce the impact of
1.96 markus 1826: * traffic analysis. We need to match the
1.95 markus 1827: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1828: * (4 byte channel id + buf)
1.91 markus 1829: */
1.95 markus 1830: packet_send_ignore(4 + len);
1.91 markus 1831: packet_send();
1832: }
1.25 markus 1833: }
1.41 markus 1834: buffer_consume(&c->output, len);
1.44 markus 1835: }
1.309 djm 1836: out:
1837: if (compat20 && olen > 0)
1838: c->local_consumed += olen - buffer_len(&c->output);
1.44 markus 1839: return 1;
1840: }
1.241 deraadt 1841:
1.127 itojun 1842: static int
1.237 deraadt 1843: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1844: {
1.214 markus 1845: char buf[CHAN_RBUF];
1.44 markus 1846: int len;
1847:
1.45 markus 1848: /** XXX handle drain efd, too */
1.44 markus 1849: if (c->efd != -1) {
1850: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1851: FD_ISSET(c->efd, writeset) &&
1852: buffer_len(&c->extended) > 0) {
1853: len = write(c->efd, buffer_ptr(&c->extended),
1854: buffer_len(&c->extended));
1.70 markus 1855: debug2("channel %d: written %d to efd %d",
1.44 markus 1856: c->self, len, c->efd);
1.93 markus 1857: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1858: return 1;
1859: if (len <= 0) {
1860: debug2("channel %d: closing write-efd %d",
1861: c->self, c->efd);
1.132 markus 1862: channel_close_fd(&c->efd);
1.93 markus 1863: } else {
1.44 markus 1864: buffer_consume(&c->extended, len);
1865: c->local_consumed += len;
1866: }
1.306 djm 1867: } else if (c->efd != -1 &&
1868: (c->extended_usage == CHAN_EXTENDED_READ ||
1869: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 1870: FD_ISSET(c->efd, readset)) {
1871: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1872: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1873: c->self, len, c->efd);
1.93 markus 1874: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1875: return 1;
1876: if (len <= 0) {
1877: debug2("channel %d: closing read-efd %d",
1.45 markus 1878: c->self, c->efd);
1.132 markus 1879: channel_close_fd(&c->efd);
1.93 markus 1880: } else {
1.306 djm 1881: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1882: debug3("channel %d: discard efd",
1883: c->self);
1884: } else
1885: buffer_append(&c->extended, buf, len);
1.93 markus 1886: }
1.44 markus 1887: }
1888: }
1889: return 1;
1890: }
1.241 deraadt 1891:
1.259 stevesk 1892: /* ARGSUSED */
1.127 itojun 1893: static int
1.93 markus 1894: channel_check_window(Channel *c)
1.44 markus 1895: {
1.104 markus 1896: if (c->type == SSH_CHANNEL_OPEN &&
1897: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1898: ((c->local_window_max - c->local_window >
1.269 markus 1899: c->local_maxpacket*3) ||
1900: c->local_window < c->local_window_max/2) &&
1.44 markus 1901: c->local_consumed > 0) {
1902: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1903: packet_put_int(c->remote_id);
1904: packet_put_int(c->local_consumed);
1905: packet_send();
1.70 markus 1906: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1907: c->self, c->local_window,
1908: c->local_consumed);
1909: c->local_window += c->local_consumed;
1910: c->local_consumed = 0;
1.1 deraadt 1911: }
1.41 markus 1912: return 1;
1.1 deraadt 1913: }
1914:
1.127 itojun 1915: static void
1.237 deraadt 1916: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1917: {
1918: channel_handle_rfd(c, readset, writeset);
1919: channel_handle_wfd(c, readset, writeset);
1.157 markus 1920: if (!compat20)
1.137 markus 1921: return;
1.44 markus 1922: channel_handle_efd(c, readset, writeset);
1.93 markus 1923: channel_check_window(c);
1.44 markus 1924: }
1925:
1.302 djm 1926: static u_int
1927: read_mux(Channel *c, u_int need)
1928: {
1929: char buf[CHAN_RBUF];
1930: int len;
1931: u_int rlen;
1932:
1933: if (buffer_len(&c->input) < need) {
1934: rlen = need - buffer_len(&c->input);
1.352 deraadt 1935: len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
1.349 naddy 1936: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1937: return buffer_len(&c->input);
1.302 djm 1938: if (len <= 0) {
1.349 naddy 1939: debug2("channel %d: ctl read<=0 rfd %d len %d",
1940: c->self, c->rfd, len);
1941: chan_read_failed(c);
1942: return 0;
1.302 djm 1943: } else
1944: buffer_append(&c->input, buf, len);
1945: }
1946: return buffer_len(&c->input);
1947: }
1948:
1949: static void
1950: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1951: {
1952: u_int need;
1953: ssize_t len;
1954:
1955: if (!compat20)
1956: fatal("%s: entered with !compat20", __func__);
1957:
1.304 djm 1958: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1959: (c->istate == CHAN_INPUT_OPEN ||
1960: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1961: /*
1962: * Don't not read past the precise end of packets to
1963: * avoid disrupting fd passing.
1964: */
1965: if (read_mux(c, 4) < 4) /* read header */
1966: return;
1967: need = get_u32(buffer_ptr(&c->input));
1968: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1969: if (need > CHANNEL_MUX_MAX_PACKET) {
1970: debug2("channel %d: packet too big %u > %u",
1971: c->self, CHANNEL_MUX_MAX_PACKET, need);
1972: chan_rcvd_oclose(c);
1973: return;
1974: }
1975: if (read_mux(c, need + 4) < need + 4) /* read body */
1976: return;
1977: if (c->mux_rcb(c) != 0) {
1978: debug("channel %d: mux_rcb failed", c->self);
1979: chan_mark_dead(c);
1980: return;
1981: }
1982: }
1983:
1984: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1985: buffer_len(&c->output) > 0) {
1986: len = write(c->wfd, buffer_ptr(&c->output),
1987: buffer_len(&c->output));
1988: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1989: return;
1990: if (len <= 0) {
1991: chan_mark_dead(c);
1992: return;
1993: }
1994: buffer_consume(&c->output, len);
1995: }
1996: }
1997:
1998: static void
1999: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
2000: {
2001: Channel *nc;
2002: struct sockaddr_storage addr;
2003: socklen_t addrlen;
2004: int newsock;
2005: uid_t euid;
2006: gid_t egid;
2007:
2008: if (!FD_ISSET(c->sock, readset))
2009: return;
2010:
2011: debug("multiplexing control connection");
2012:
2013: /*
2014: * Accept connection on control socket
2015: */
2016: memset(&addr, 0, sizeof(addr));
2017: addrlen = sizeof(addr);
2018: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
2019: &addrlen)) == -1) {
2020: error("%s accept: %s", __func__, strerror(errno));
1.317 djm 2021: if (errno == EMFILE || errno == ENFILE)
1.322 dtucker 2022: c->notbefore = monotime() + 1;
1.302 djm 2023: return;
2024: }
2025:
2026: if (getpeereid(newsock, &euid, &egid) < 0) {
2027: error("%s getpeereid failed: %s", __func__,
2028: strerror(errno));
2029: close(newsock);
2030: return;
2031: }
2032: if ((euid != 0) && (getuid() != euid)) {
2033: error("multiplex uid mismatch: peer euid %u != uid %u",
2034: (u_int)euid, (u_int)getuid());
2035: close(newsock);
2036: return;
2037: }
2038: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
2039: newsock, newsock, -1, c->local_window_max,
2040: c->local_maxpacket, 0, "mux-control", 1);
2041: nc->mux_rcb = c->mux_rcb;
2042: debug3("%s: new mux channel %d fd %d", __func__,
2043: nc->self, nc->sock);
2044: /* establish state */
2045: nc->mux_rcb(nc);
2046: /* mux state transitions must not elicit protocol messages */
2047: nc->flags |= CHAN_LOCAL;
2048: }
2049:
1.259 stevesk 2050: /* ARGSUSED */
1.127 itojun 2051: static void
1.237 deraadt 2052: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 2053: {
1.41 markus 2054: int len;
1.180 deraadt 2055:
1.41 markus 2056: /* Send buffered output data to the socket. */
2057: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2058: len = write(c->sock, buffer_ptr(&c->output),
2059: buffer_len(&c->output));
2060: if (len <= 0)
1.158 markus 2061: buffer_clear(&c->output);
1.41 markus 2062: else
2063: buffer_consume(&c->output, len);
2064: }
2065: }
1.25 markus 2066:
1.127 itojun 2067: static void
1.44 markus 2068: channel_handler_init_20(void)
2069: {
1.157 markus 2070: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 2071: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 2072: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 2073: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.336 millert 2074: channel_pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2075: channel_pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
1.51 markus 2076: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 2077: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 2078: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 2079: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 2080: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2081: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 2082:
1.157 markus 2083: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 2084: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 2085: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.336 millert 2086: channel_post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2087: channel_post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
1.51 markus 2088: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 2089: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 2090: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 2091: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 2092: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2093: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 2094: }
2095:
1.127 itojun 2096: static void
1.41 markus 2097: channel_handler_init_13(void)
2098: {
2099: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2100: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2101: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2102: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2103: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2104: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2105: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 2106: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 2107: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 2108:
1.157 markus 2109: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 2110: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2111: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2112: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2113: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 2114: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 2115: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 2116: }
1.25 markus 2117:
1.127 itojun 2118: static void
1.41 markus 2119: channel_handler_init_15(void)
2120: {
1.157 markus 2121: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 2122: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 2123: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2124: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2125: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 2126: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 2127: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 2128:
1.41 markus 2129: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2130: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2131: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 2132: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 2133: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 2134: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 2135: }
1.27 markus 2136:
1.127 itojun 2137: static void
1.41 markus 2138: channel_handler_init(void)
2139: {
2140: int i;
1.180 deraadt 2141:
1.148 deraadt 2142: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2143: channel_pre[i] = NULL;
2144: channel_post[i] = NULL;
2145: }
1.44 markus 2146: if (compat20)
2147: channel_handler_init_20();
2148: else if (compat13)
1.41 markus 2149: channel_handler_init_13();
2150: else
2151: channel_handler_init_15();
2152: }
1.25 markus 2153:
1.140 markus 2154: /* gc dead channels */
2155: static void
2156: channel_garbage_collect(Channel *c)
2157: {
2158: if (c == NULL)
2159: return;
2160: if (c->detach_user != NULL) {
1.225 djm 2161: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2162: return;
1.194 markus 2163: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2164: c->detach_user(c->self, NULL);
2165: /* if we still have a callback */
2166: if (c->detach_user != NULL)
2167: return;
1.194 markus 2168: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2169: }
2170: if (!chan_is_dead(c, 1))
2171: return;
1.194 markus 2172: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2173: channel_free(c);
2174: }
2175:
1.127 itojun 2176: static void
1.317 djm 2177: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2178: time_t *unpause_secs)
1.41 markus 2179: {
2180: static int did_init = 0;
1.299 markus 2181: u_int i, oalloc;
1.41 markus 2182: Channel *c;
1.317 djm 2183: time_t now;
1.25 markus 2184:
1.41 markus 2185: if (!did_init) {
2186: channel_handler_init();
2187: did_init = 1;
2188: }
1.322 dtucker 2189: now = monotime();
1.317 djm 2190: if (unpause_secs != NULL)
2191: *unpause_secs = 0;
1.299 markus 2192: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2193: c = channels[i];
2194: if (c == NULL)
1.41 markus 2195: continue;
1.299 markus 2196: if (c->delayed) {
2197: if (ftab == channel_pre)
2198: c->delayed = 0;
2199: else
2200: continue;
2201: }
1.317 djm 2202: if (ftab[c->type] != NULL) {
2203: /*
2204: * Run handlers that are not paused.
2205: */
2206: if (c->notbefore <= now)
2207: (*ftab[c->type])(c, readset, writeset);
2208: else if (unpause_secs != NULL) {
2209: /*
2210: * Collect the time that the earliest
2211: * channel comes off pause.
2212: */
2213: debug3("%s: chan %d: skip for %d more seconds",
2214: __func__, c->self,
2215: (int)(c->notbefore - now));
2216: if (*unpause_secs == 0 ||
2217: (c->notbefore - now) < *unpause_secs)
2218: *unpause_secs = c->notbefore - now;
2219: }
2220: }
1.140 markus 2221: channel_garbage_collect(c);
1.1 deraadt 2222: }
1.317 djm 2223: if (unpause_secs != NULL && *unpause_secs != 0)
2224: debug3("%s: first channel unpauses in %d seconds",
2225: __func__, (int)*unpause_secs);
1.1 deraadt 2226: }
2227:
1.121 markus 2228: /*
2229: * Allocate/update select bitmasks and add any bits relevant to channels in
2230: * select bitmasks.
2231: */
1.49 markus 2232: void
1.100 markus 2233: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.318 djm 2234: u_int *nallocp, time_t *minwait_secs, int rekeying)
1.41 markus 2235: {
1.243 djm 2236: u_int n, sz, nfdset;
1.84 markus 2237:
1.352 deraadt 2238: n = MAXIMUM(*maxfdp, channel_max_fd);
1.84 markus 2239:
1.243 djm 2240: nfdset = howmany(n+1, NFDBITS);
2241: /* Explicitly test here, because xrealloc isn't always called */
1.341 millert 2242: if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
1.243 djm 2243: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2244: sz = nfdset * sizeof(fd_mask);
2245:
1.132 markus 2246: /* perhaps check sz < nalloc/2 and shrink? */
2247: if (*readsetp == NULL || sz > *nallocp) {
1.342 deraadt 2248: *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
2249: *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2250: *nallocp = sz;
1.84 markus 2251: }
1.132 markus 2252: *maxfdp = n;
1.84 markus 2253: memset(*readsetp, 0, sz);
2254: memset(*writesetp, 0, sz);
2255:
1.100 markus 2256: if (!rekeying)
1.317 djm 2257: channel_handler(channel_pre, *readsetp, *writesetp,
2258: minwait_secs);
1.41 markus 2259: }
2260:
1.121 markus 2261: /*
2262: * After select, perform any appropriate operations for channels which have
2263: * events pending.
2264: */
1.49 markus 2265: void
1.237 deraadt 2266: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2267: {
1.317 djm 2268: channel_handler(channel_post, readset, writeset, NULL);
1.41 markus 2269: }
2270:
1.121 markus 2271:
1.84 markus 2272: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2273: void
1.142 itojun 2274: channel_output_poll(void)
1.1 deraadt 2275: {
1.41 markus 2276: Channel *c;
1.209 avsm 2277: u_int i, len;
1.1 deraadt 2278:
1.25 markus 2279: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2280: c = channels[i];
2281: if (c == NULL)
2282: continue;
1.37 markus 2283:
1.121 markus 2284: /*
2285: * We are only interested in channels that can have buffered
2286: * incoming data.
2287: */
1.37 markus 2288: if (compat13) {
1.41 markus 2289: if (c->type != SSH_CHANNEL_OPEN &&
2290: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2291: continue;
2292: } else {
1.41 markus 2293: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2294: continue;
2295: }
1.46 markus 2296: if (compat20 &&
2297: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2298: /* XXX is this true? */
1.140 markus 2299: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2300: continue;
2301: }
1.25 markus 2302:
2303: /* Get the amount of buffered data for this channel. */
1.93 markus 2304: if ((c->istate == CHAN_INPUT_OPEN ||
2305: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2306: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2307: if (c->datagram) {
2308: if (len > 0) {
2309: u_char *data;
2310: u_int dlen;
2311:
2312: data = buffer_get_string(&c->input,
2313: &dlen);
1.309 djm 2314: if (dlen > c->remote_window ||
2315: dlen > c->remote_maxpacket) {
2316: debug("channel %d: datagram "
2317: "too big for channel",
2318: c->self);
1.321 djm 2319: free(data);
1.309 djm 2320: continue;
2321: }
1.228 reyk 2322: packet_start(SSH2_MSG_CHANNEL_DATA);
2323: packet_put_int(c->remote_id);
2324: packet_put_string(data, dlen);
2325: packet_send();
1.345 djm 2326: c->remote_window -= dlen;
1.321 djm 2327: free(data);
1.228 reyk 2328: }
2329: continue;
2330: }
1.121 markus 2331: /*
2332: * Send some data for the other side over the secure
2333: * connection.
2334: */
1.44 markus 2335: if (compat20) {
2336: if (len > c->remote_window)
2337: len = c->remote_window;
2338: if (len > c->remote_maxpacket)
2339: len = c->remote_maxpacket;
1.25 markus 2340: } else {
1.44 markus 2341: if (packet_is_interactive()) {
2342: if (len > 1024)
2343: len = 512;
2344: } else {
2345: /* Keep the packets at reasonable size. */
2346: if (len > packet_get_maxsize()/2)
2347: len = packet_get_maxsize()/2;
2348: }
1.25 markus 2349: }
1.41 markus 2350: if (len > 0) {
1.44 markus 2351: packet_start(compat20 ?
2352: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2353: packet_put_int(c->remote_id);
2354: packet_put_string(buffer_ptr(&c->input), len);
2355: packet_send();
2356: buffer_consume(&c->input, len);
2357: c->remote_window -= len;
2358: }
2359: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2360: if (compat13)
2361: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2362: /*
2363: * input-buffer is empty and read-socket shutdown:
1.172 markus 2364: * tell peer, that we will not send more data: send IEOF.
2365: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2366: */
1.172 markus 2367: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2368: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2369: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2370: else
2371: chan_ibuf_empty(c);
1.25 markus 2372: }
1.44 markus 2373: /* Send extended data, i.e. stderr */
2374: if (compat20 &&
1.172 markus 2375: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2376: c->remote_window > 0 &&
2377: (len = buffer_len(&c->extended)) > 0 &&
2378: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2379: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2380: c->self, c->remote_window, buffer_len(&c->extended),
2381: c->extended_usage);
1.44 markus 2382: if (len > c->remote_window)
2383: len = c->remote_window;
2384: if (len > c->remote_maxpacket)
2385: len = c->remote_maxpacket;
2386: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2387: packet_put_int(c->remote_id);
2388: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2389: packet_put_string(buffer_ptr(&c->extended), len);
2390: packet_send();
2391: buffer_consume(&c->extended, len);
2392: c->remote_window -= len;
1.93 markus 2393: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2394: }
1.25 markus 2395: }
1.1 deraadt 2396: }
2397:
1.354 ! markus 2398: /* -- mux proxy support */
! 2399:
! 2400: /*
! 2401: * When multiplexing channel messages for mux clients we have to deal
! 2402: * with downstream messages from the mux client and upstream messages
! 2403: * from the ssh server:
! 2404: * 1) Handling downstream messages is straightforward and happens
! 2405: * in channel_proxy_downstream():
! 2406: * - We forward all messages (mostly) unmodified to the server.
! 2407: * - However, in order to route messages from upstream to the correct
! 2408: * downstream client, we have to replace the channel IDs used by the
! 2409: * mux clients with a unique channel ID because the mux clients might
! 2410: * use conflicting channel IDs.
! 2411: * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
! 2412: * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
! 2413: * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
! 2414: * with the newly allocated channel ID.
! 2415: * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
! 2416: * channels and procesed by channel_proxy_upstream(). The local channel ID
! 2417: * is then translated back to the original mux client ID.
! 2418: * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
! 2419: * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
! 2420: * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
! 2421: * downstream mux client are removed.
! 2422: * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
! 2423: * requires more work, because they are not addressed to a specific
! 2424: * channel. E.g. client_request_forwarded_tcpip() needs to figure
! 2425: * out whether the request is addressed to the local client or a
! 2426: * specific downstream client based on the listen-address/port.
! 2427: * 6) Agent and X11-Forwarding have a similar problem and are currenly
! 2428: * not supported as the matching session/channel cannot be identified
! 2429: * easily.
! 2430: */
! 2431:
! 2432: /*
! 2433: * receive packets from downstream mux clients:
! 2434: * channel callback fired on read from mux client, creates
! 2435: * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
! 2436: * on channel creation.
! 2437: */
! 2438: int
! 2439: channel_proxy_downstream(Channel *downstream)
! 2440: {
! 2441: Channel *c = NULL;
! 2442: struct ssh *ssh = active_state;
! 2443: struct sshbuf *original = NULL, *modified = NULL;
! 2444: const u_char *cp;
! 2445: char *ctype = NULL, *listen_host = NULL;
! 2446: u_char type;
! 2447: size_t have;
! 2448: int ret = -1, r, id, remote_id, listen_port, idx;
! 2449:
! 2450: /* sshbuf_dump(&downstream->input, stderr); */
! 2451: if ((r = sshbuf_get_string_direct(&downstream->input, &cp, &have))
! 2452: != 0) {
! 2453: error("%s: malformed message: %s", __func__, ssh_err(r));
! 2454: return -1;
! 2455: }
! 2456: if (have < 2) {
! 2457: error("%s: short message", __func__);
! 2458: return -1;
! 2459: }
! 2460: type = cp[1];
! 2461: /* skip padlen + type */
! 2462: cp += 2;
! 2463: have -= 2;
! 2464: if (ssh_packet_log_type(type))
! 2465: debug3("%s: channel %u: down->up: type %u", __func__,
! 2466: downstream->self, type);
! 2467:
! 2468: switch (type) {
! 2469: case SSH2_MSG_CHANNEL_OPEN:
! 2470: if ((original = sshbuf_from(cp, have)) == NULL ||
! 2471: (modified = sshbuf_new()) == NULL) {
! 2472: error("%s: alloc", __func__);
! 2473: goto out;
! 2474: }
! 2475: if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
! 2476: (r = sshbuf_get_u32(original, &id)) != 0) {
! 2477: error("%s: parse error %s", __func__, ssh_err(r));
! 2478: goto out;
! 2479: }
! 2480: c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
! 2481: -1, -1, -1, 0, 0, 0, ctype, 1);
! 2482: c->mux_ctx = downstream; /* point to mux client */
! 2483: c->mux_downstream_id = id; /* original downstream id */
! 2484: if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
! 2485: (r = sshbuf_put_u32(modified, c->self)) != 0 ||
! 2486: (r = sshbuf_putb(modified, original)) != 0) {
! 2487: error("%s: compose error %s", __func__, ssh_err(r));
! 2488: channel_free(c);
! 2489: goto out;
! 2490: }
! 2491: break;
! 2492: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
! 2493: /*
! 2494: * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
! 2495: * need to parse 'remote_id' instead of 'ctype'.
! 2496: */
! 2497: if ((original = sshbuf_from(cp, have)) == NULL ||
! 2498: (modified = sshbuf_new()) == NULL) {
! 2499: error("%s: alloc", __func__);
! 2500: goto out;
! 2501: }
! 2502: if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
! 2503: (r = sshbuf_get_u32(original, &id)) != 0) {
! 2504: error("%s: parse error %s", __func__, ssh_err(r));
! 2505: goto out;
! 2506: }
! 2507: c = channel_new("mux proxy", SSH_CHANNEL_MUX_PROXY,
! 2508: -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
! 2509: c->mux_ctx = downstream; /* point to mux client */
! 2510: c->mux_downstream_id = id;
! 2511: c->remote_id = remote_id;
! 2512: if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
! 2513: (r = sshbuf_put_u32(modified, c->self)) != 0 ||
! 2514: (r = sshbuf_putb(modified, original)) != 0) {
! 2515: error("%s: compose error %s", __func__, ssh_err(r));
! 2516: channel_free(c);
! 2517: goto out;
! 2518: }
! 2519: break;
! 2520: case SSH2_MSG_GLOBAL_REQUEST:
! 2521: if ((original = sshbuf_from(cp, have)) == NULL) {
! 2522: error("%s: alloc", __func__);
! 2523: goto out;
! 2524: }
! 2525: if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
! 2526: error("%s: parse error %s", __func__, ssh_err(r));
! 2527: goto out;
! 2528: }
! 2529: if (strcmp(ctype, "tcpip-forward") != 0) {
! 2530: error("%s: unsupported request %s", __func__, ctype);
! 2531: goto out;
! 2532: }
! 2533: if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
! 2534: (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
! 2535: (r = sshbuf_get_u32(original, &listen_port)) != 0) {
! 2536: error("%s: parse error %s", __func__, ssh_err(r));
! 2537: goto out;
! 2538: }
! 2539: /* Record that connection to this host/port is permitted. */
! 2540: permitted_opens = xreallocarray(permitted_opens,
! 2541: num_permitted_opens + 1, sizeof(*permitted_opens));
! 2542: idx = num_permitted_opens++;
! 2543: permitted_opens[idx].host_to_connect = xstrdup("<mux>");
! 2544: permitted_opens[idx].port_to_connect = -1;
! 2545: permitted_opens[idx].listen_host = listen_host;
! 2546: permitted_opens[idx].listen_port = listen_port;
! 2547: permitted_opens[idx].downstream = downstream;
! 2548: listen_host = NULL;
! 2549: break;
! 2550: case SSH2_MSG_CHANNEL_CLOSE:
! 2551: if (have < 4)
! 2552: break;
! 2553: remote_id = PEEK_U32(cp);
! 2554: if ((c = channel_by_remote_id(remote_id)) != NULL) {
! 2555: if (c->flags & CHAN_CLOSE_RCVD)
! 2556: channel_free(c);
! 2557: else
! 2558: c->flags |= CHAN_CLOSE_SENT;
! 2559: }
! 2560: break;
! 2561: }
! 2562: if (modified) {
! 2563: if ((r = sshpkt_start(ssh, type)) != 0 ||
! 2564: (r = sshpkt_putb(ssh, modified)) != 0 ||
! 2565: (r = sshpkt_send(ssh)) != 0) {
! 2566: error("%s: send %s", __func__, ssh_err(r));
! 2567: goto out;
! 2568: }
! 2569: } else {
! 2570: if ((r = sshpkt_start(ssh, type)) != 0 ||
! 2571: (r = sshpkt_put(ssh, cp, have)) != 0 ||
! 2572: (r = sshpkt_send(ssh)) != 0) {
! 2573: error("%s: send %s", __func__, ssh_err(r));
! 2574: goto out;
! 2575: }
! 2576: }
! 2577: ret = 0;
! 2578: out:
! 2579: free(ctype);
! 2580: free(listen_host);
! 2581: sshbuf_free(original);
! 2582: sshbuf_free(modified);
! 2583: return ret;
! 2584: }
! 2585:
! 2586: /*
! 2587: * receive packets from upstream server and de-multiplex packets
! 2588: * to correct downstream:
! 2589: * implemented as a helper for channel input handlers,
! 2590: * replaces local (proxy) channel ID with downstream channel ID.
! 2591: */
! 2592: int
! 2593: channel_proxy_upstream(Channel *c, int type, u_int32_t seq, void *ctxt)
! 2594: {
! 2595: struct ssh *ssh = active_state;
! 2596: struct sshbuf *b = NULL;
! 2597: Channel *downstream;
! 2598: const u_char *cp = NULL;
! 2599: size_t len;
! 2600: int r;
! 2601:
! 2602: /*
! 2603: * When receiving packets from the peer we need to check whether we
! 2604: * need to forward the packets to the mux client. In this case we
! 2605: * restore the orignal channel id and keep track of CLOSE messages,
! 2606: * so we can cleanup the channel.
! 2607: */
! 2608: if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
! 2609: return 0;
! 2610: if ((downstream = c->mux_ctx) == NULL)
! 2611: return 0;
! 2612: switch (type) {
! 2613: case SSH2_MSG_CHANNEL_CLOSE:
! 2614: case SSH2_MSG_CHANNEL_DATA:
! 2615: case SSH2_MSG_CHANNEL_EOF:
! 2616: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
! 2617: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
! 2618: case SSH2_MSG_CHANNEL_OPEN_FAILURE:
! 2619: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
! 2620: case SSH2_MSG_CHANNEL_SUCCESS:
! 2621: case SSH2_MSG_CHANNEL_FAILURE:
! 2622: case SSH2_MSG_CHANNEL_REQUEST:
! 2623: break;
! 2624: default:
! 2625: debug2("%s: channel %u: unsupported type %u", __func__,
! 2626: c->self, type);
! 2627: return 0;
! 2628: }
! 2629: if ((b = sshbuf_new()) == NULL) {
! 2630: error("%s: alloc reply", __func__);
! 2631: goto out;
! 2632: }
! 2633: /* get remaining payload (after id) */
! 2634: cp = sshpkt_ptr(ssh, &len);
! 2635: if (cp == NULL) {
! 2636: error("%s: no packet", __func__);
! 2637: goto out;
! 2638: }
! 2639: /* translate id and send to muxclient */
! 2640: if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
! 2641: (r = sshbuf_put_u8(b, type)) != 0 ||
! 2642: (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
! 2643: (r = sshbuf_put(b, cp, len)) != 0 ||
! 2644: (r = sshbuf_put_stringb(&downstream->output, b)) != 0) {
! 2645: error("%s: compose for muxclient %s", __func__, ssh_err(r));
! 2646: goto out;
! 2647: }
! 2648: /* sshbuf_dump(b, stderr); */
! 2649: if (ssh_packet_log_type(type))
! 2650: debug3("%s: channel %u: up->down: type %u", __func__, c->self,
! 2651: type);
! 2652: out:
! 2653: /* update state */
! 2654: switch (type) {
! 2655: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
! 2656: /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
! 2657: if (cp && len > 4)
! 2658: c->remote_id = PEEK_U32(cp);
! 2659: break;
! 2660: case SSH2_MSG_CHANNEL_CLOSE:
! 2661: if (c->flags & CHAN_CLOSE_SENT)
! 2662: channel_free(c);
! 2663: else
! 2664: c->flags |= CHAN_CLOSE_RCVD;
! 2665: break;
! 2666: }
! 2667: sshbuf_free(b);
! 2668: return 1;
! 2669: }
1.121 markus 2670:
2671: /* -- protocol input */
1.249 djm 2672:
2673: /* ARGSUSED */
1.339 markus 2674: int
1.154 markus 2675: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2676: {
1.37 markus 2677: int id;
1.332 djm 2678: const u_char *data;
1.309 djm 2679: u_int data_len, win_len;
1.41 markus 2680: Channel *c;
1.25 markus 2681:
2682: /* Get the channel number and verify it. */
1.37 markus 2683: id = packet_get_int();
1.41 markus 2684: c = channel_lookup(id);
2685: if (c == NULL)
1.37 markus 2686: packet_disconnect("Received data for nonexistent channel %d.", id);
1.354 ! markus 2687: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2688: return 0;
1.25 markus 2689:
2690: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2691: if (c->type != SSH_CHANNEL_OPEN &&
2692: c->type != SSH_CHANNEL_X11_OPEN)
1.339 markus 2693: return 0;
1.37 markus 2694:
1.25 markus 2695: /* Get the data. */
1.274 markus 2696: data = packet_get_string_ptr(&data_len);
1.309 djm 2697: win_len = data_len;
2698: if (c->datagram)
2699: win_len += 4; /* string length header */
1.200 markus 2700:
2701: /*
2702: * Ignore data for protocol > 1.3 if output end is no longer open.
2703: * For protocol 2 the sending side is reducing its window as it sends
2704: * data, so we must 'fake' consumption of the data in order to ensure
2705: * that window updates are sent back. Otherwise the connection might
2706: * deadlock.
2707: */
2708: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2709: if (compat20) {
1.309 djm 2710: c->local_window -= win_len;
2711: c->local_consumed += win_len;
1.200 markus 2712: }
1.339 markus 2713: return 0;
1.200 markus 2714: }
1.41 markus 2715:
1.143 deraadt 2716: if (compat20) {
1.309 djm 2717: if (win_len > c->local_maxpacket) {
1.188 itojun 2718: logit("channel %d: rcvd big packet %d, maxpack %d",
1.309 djm 2719: c->self, win_len, c->local_maxpacket);
1.44 markus 2720: }
1.309 djm 2721: if (win_len > c->local_window) {
1.188 itojun 2722: logit("channel %d: rcvd too much data %d, win %d",
1.309 djm 2723: c->self, win_len, c->local_window);
1.339 markus 2724: return 0;
1.44 markus 2725: }
1.309 djm 2726: c->local_window -= win_len;
1.44 markus 2727: }
1.228 reyk 2728: if (c->datagram)
2729: buffer_put_string(&c->output, data, data_len);
2730: else
2731: buffer_append(&c->output, data, data_len);
1.274 markus 2732: packet_check_eom();
1.339 markus 2733: return 0;
1.1 deraadt 2734: }
1.121 markus 2735:
1.249 djm 2736: /* ARGSUSED */
1.339 markus 2737: int
1.154 markus 2738: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2739: {
2740: int id;
2741: char *data;
1.177 markus 2742: u_int data_len, tcode;
1.44 markus 2743: Channel *c;
2744:
2745: /* Get the channel number and verify it. */
2746: id = packet_get_int();
2747: c = channel_lookup(id);
2748:
2749: if (c == NULL)
2750: packet_disconnect("Received extended_data for bad channel %d.", id);
1.354 ! markus 2751: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2752: return 0;
1.44 markus 2753: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2754: logit("channel %d: ext data for non open", id);
1.339 markus 2755: return 0;
1.172 markus 2756: }
2757: if (c->flags & CHAN_EOF_RCVD) {
2758: if (datafellows & SSH_BUG_EXTEOF)
2759: debug("channel %d: accepting ext data after eof", id);
2760: else
2761: packet_disconnect("Received extended_data after EOF "
2762: "on channel %d.", id);
1.44 markus 2763: }
2764: tcode = packet_get_int();
2765: if (c->efd == -1 ||
2766: c->extended_usage != CHAN_EXTENDED_WRITE ||
2767: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2768: logit("channel %d: bad ext data", c->self);
1.339 markus 2769: return 0;
1.44 markus 2770: }
2771: data = packet_get_string(&data_len);
1.152 markus 2772: packet_check_eom();
1.44 markus 2773: if (data_len > c->local_window) {
1.188 itojun 2774: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2775: c->self, data_len, c->local_window);
1.321 djm 2776: free(data);
1.339 markus 2777: return 0;
1.44 markus 2778: }
1.70 markus 2779: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2780: c->local_window -= data_len;
2781: buffer_append(&c->extended, data, data_len);
1.321 djm 2782: free(data);
1.339 markus 2783: return 0;
1.44 markus 2784: }
2785:
1.249 djm 2786: /* ARGSUSED */
1.339 markus 2787: int
1.154 markus 2788: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2789: {
2790: int id;
2791: Channel *c;
2792:
2793: id = packet_get_int();
1.152 markus 2794: packet_check_eom();
1.41 markus 2795: c = channel_lookup(id);
2796: if (c == NULL)
2797: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1.354 ! markus 2798: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2799: return 0;
1.41 markus 2800: chan_rcvd_ieof(c);
1.133 markus 2801:
2802: /* XXX force input close */
1.156 markus 2803: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2804: debug("channel %d: FORCE input drain", c->self);
2805: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2806: if (buffer_len(&c->input) == 0)
2807: chan_ibuf_empty(c);
1.133 markus 2808: }
1.339 markus 2809: return 0;
1.41 markus 2810: }
1.1 deraadt 2811:
1.249 djm 2812: /* ARGSUSED */
1.339 markus 2813: int
1.154 markus 2814: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2815: {
1.41 markus 2816: int id;
2817: Channel *c;
1.1 deraadt 2818:
1.41 markus 2819: id = packet_get_int();
1.152 markus 2820: packet_check_eom();
1.41 markus 2821: c = channel_lookup(id);
2822: if (c == NULL)
2823: packet_disconnect("Received close for nonexistent channel %d.", id);
1.354 ! markus 2824: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2825: return 0;
1.27 markus 2826: /*
2827: * Send a confirmation that we have closed the channel and no more
2828: * data is coming for it.
2829: */
1.25 markus 2830: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2831: packet_put_int(c->remote_id);
1.25 markus 2832: packet_send();
2833:
1.27 markus 2834: /*
2835: * If the channel is in closed state, we have sent a close request,
2836: * and the other side will eventually respond with a confirmation.
2837: * Thus, we cannot free the channel here, because then there would be
2838: * no-one to receive the confirmation. The channel gets freed when
2839: * the confirmation arrives.
2840: */
1.41 markus 2841: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2842: /*
2843: * Not a closed channel - mark it as draining, which will
2844: * cause it to be freed later.
2845: */
1.158 markus 2846: buffer_clear(&c->input);
1.41 markus 2847: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2848: }
1.339 markus 2849: return 0;
1.1 deraadt 2850: }
2851:
1.41 markus 2852: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2853: /* ARGSUSED */
1.339 markus 2854: int
1.154 markus 2855: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2856: {
2857: int id = packet_get_int();
2858: Channel *c = channel_lookup(id);
1.151 markus 2859:
1.41 markus 2860: if (c == NULL)
2861: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1.354 ! markus 2862: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2863: return 0;
! 2864: packet_check_eom();
1.41 markus 2865: chan_rcvd_oclose(c);
1.339 markus 2866: return 0;
1.41 markus 2867: }
1.1 deraadt 2868:
1.249 djm 2869: /* ARGSUSED */
1.339 markus 2870: int
1.154 markus 2871: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2872: {
1.41 markus 2873: int id = packet_get_int();
2874: Channel *c = channel_lookup(id);
1.1 deraadt 2875:
1.41 markus 2876: if (c == NULL)
2877: packet_disconnect("Received close confirmation for "
2878: "out-of-range channel %d.", id);
1.354 ! markus 2879: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2880: return 0;
! 2881: packet_check_eom();
1.323 dtucker 2882: if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
1.41 markus 2883: packet_disconnect("Received close confirmation for "
2884: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2885: channel_free(c);
1.339 markus 2886: return 0;
1.1 deraadt 2887: }
2888:
1.249 djm 2889: /* ARGSUSED */
1.339 markus 2890: int
1.154 markus 2891: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2892: {
1.41 markus 2893: int id, remote_id;
2894: Channel *c;
1.1 deraadt 2895:
1.41 markus 2896: id = packet_get_int();
2897: c = channel_lookup(id);
1.25 markus 2898:
1.354 ! markus 2899: if (c==NULL)
! 2900: packet_disconnect("Received open confirmation for "
! 2901: "unknown channel %d.", id);
! 2902: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2903: return 0;
! 2904: if (c->type != SSH_CHANNEL_OPENING)
1.41 markus 2905: packet_disconnect("Received open confirmation for "
2906: "non-opening channel %d.", id);
2907: remote_id = packet_get_int();
1.27 markus 2908: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2909: c->remote_id = remote_id;
2910: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2911:
2912: if (compat20) {
2913: c->remote_window = packet_get_int();
2914: c->remote_maxpacket = packet_get_int();
1.275 djm 2915: if (c->open_confirm) {
1.70 markus 2916: debug2("callback start");
1.304 djm 2917: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2918: debug2("callback done");
1.44 markus 2919: }
1.194 markus 2920: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2921: c->remote_window, c->remote_maxpacket);
2922: }
1.152 markus 2923: packet_check_eom();
1.339 markus 2924: return 0;
1.1 deraadt 2925: }
2926:
1.127 itojun 2927: static char *
1.114 markus 2928: reason2txt(int reason)
2929: {
1.143 deraadt 2930: switch (reason) {
1.114 markus 2931: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2932: return "administratively prohibited";
2933: case SSH2_OPEN_CONNECT_FAILED:
2934: return "connect failed";
2935: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2936: return "unknown channel type";
2937: case SSH2_OPEN_RESOURCE_SHORTAGE:
2938: return "resource shortage";
2939: }
1.117 stevesk 2940: return "unknown reason";
1.114 markus 2941: }
2942:
1.249 djm 2943: /* ARGSUSED */
1.339 markus 2944: int
1.154 markus 2945: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2946: {
1.86 markus 2947: int id, reason;
2948: char *msg = NULL, *lang = NULL;
1.41 markus 2949: Channel *c;
2950:
2951: id = packet_get_int();
2952: c = channel_lookup(id);
1.25 markus 2953:
1.354 ! markus 2954: if (c==NULL)
! 2955: packet_disconnect("Received open failure for "
! 2956: "unknown channel %d.", id);
! 2957: if (channel_proxy_upstream(c, type, seq, ctxt))
! 2958: return 0;
! 2959: if (c->type != SSH_CHANNEL_OPENING)
1.41 markus 2960: packet_disconnect("Received open failure for "
2961: "non-opening channel %d.", id);
1.44 markus 2962: if (compat20) {
1.86 markus 2963: reason = packet_get_int();
1.110 markus 2964: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2965: msg = packet_get_string(NULL);
2966: lang = packet_get_string(NULL);
2967: }
1.188 itojun 2968: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2969: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.321 djm 2970: free(msg);
2971: free(lang);
1.304 djm 2972: if (c->open_confirm) {
2973: debug2("callback start");
2974: c->open_confirm(c->self, 0, c->open_confirm_ctx);
2975: debug2("callback done");
2976: }
1.44 markus 2977: }
1.152 markus 2978: packet_check_eom();
1.291 djm 2979: /* Schedule the channel for cleanup/deletion. */
2980: chan_mark_dead(c);
1.339 markus 2981: return 0;
1.44 markus 2982: }
2983:
1.249 djm 2984: /* ARGSUSED */
1.339 markus 2985: int
1.154 markus 2986: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2987: {
2988: Channel *c;
1.178 markus 2989: int id;
1.346 djm 2990: u_int adjust, tmp;
1.121 markus 2991:
2992: if (!compat20)
1.339 markus 2993: return 0;
1.121 markus 2994:
2995: /* Get the channel number and verify it. */
2996: id = packet_get_int();
2997: c = channel_lookup(id);
1.1 deraadt 2998:
1.229 markus 2999: if (c == NULL) {
3000: logit("Received window adjust for non-open channel %d.", id);
1.339 markus 3001: return 0;
1.121 markus 3002: }
1.354 ! markus 3003: if (channel_proxy_upstream(c, type, seq, ctxt))
! 3004: return 0;
1.121 markus 3005: adjust = packet_get_int();
1.152 markus 3006: packet_check_eom();
1.178 markus 3007: debug2("channel %d: rcvd adjust %u", id, adjust);
1.346 djm 3008: if ((tmp = c->remote_window + adjust) < c->remote_window)
3009: fatal("channel %d: adjust %u overflows remote window %u",
3010: id, adjust, c->remote_window);
3011: c->remote_window = tmp;
1.339 markus 3012: return 0;
1.121 markus 3013: }
1.1 deraadt 3014:
1.249 djm 3015: /* ARGSUSED */
1.339 markus 3016: int
1.154 markus 3017: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 3018: {
1.121 markus 3019: Channel *c = NULL;
3020: u_short host_port;
3021: char *host, *originator_string;
1.276 djm 3022: int remote_id;
1.121 markus 3023:
3024: remote_id = packet_get_int();
3025: host = packet_get_string(NULL);
3026: host_port = packet_get_int();
1.25 markus 3027:
1.121 markus 3028: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3029: originator_string = packet_get_string(NULL);
3030: } else {
3031: originator_string = xstrdup("unknown (remote did not supply name)");
3032: }
1.152 markus 3033: packet_check_eom();
1.336 millert 3034: c = channel_connect_to_port(host, host_port,
1.276 djm 3035: "connected socket", originator_string);
1.321 djm 3036: free(originator_string);
3037: free(host);
1.121 markus 3038: if (c == NULL) {
3039: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3040: packet_put_int(remote_id);
3041: packet_send();
1.276 djm 3042: } else
3043: c->remote_id = remote_id;
1.339 markus 3044: return 0;
1.1 deraadt 3045: }
3046:
1.275 djm 3047: /* ARGSUSED */
1.339 markus 3048: int
1.275 djm 3049: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
3050: {
3051: Channel *c;
3052: struct channel_confirm *cc;
1.289 markus 3053: int id;
1.275 djm 3054:
3055: /* Reset keepalive timeout */
1.296 andreas 3056: packet_set_alive_timeouts(0);
1.275 djm 3057:
1.289 markus 3058: id = packet_get_int();
3059: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 3060:
1.289 markus 3061: if ((c = channel_lookup(id)) == NULL) {
3062: logit("channel_input_status_confirm: %d: unknown", id);
1.339 markus 3063: return 0;
1.275 djm 3064: }
1.354 ! markus 3065: if (channel_proxy_upstream(c, type, seq, ctxt))
! 3066: return 0;
! 3067: packet_check_eom();
1.275 djm 3068: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
1.339 markus 3069: return 0;
1.275 djm 3070: cc->cb(type, c, cc->ctx);
3071: TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.329 tedu 3072: explicit_bzero(cc, sizeof(*cc));
1.321 djm 3073: free(cc);
1.339 markus 3074: return 0;
1.275 djm 3075: }
1.121 markus 3076:
3077: /* -- tcp forwarding */
1.135 markus 3078:
3079: void
3080: channel_set_af(int af)
3081: {
3082: IPv4or6 = af;
3083: }
1.121 markus 3084:
1.312 djm 3085:
3086: /*
3087: * Determine whether or not a port forward listens to loopback, the
3088: * specified address or wildcard. On the client, a specified bind
3089: * address will always override gateway_ports. On the server, a
3090: * gateway_ports of 1 (``yes'') will override the client's specification
3091: * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
3092: * will bind to whatever address the client asked for.
3093: *
3094: * Special-case listen_addrs are:
3095: *
3096: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
3097: * "" (empty string), "*" -> wildcard v4/v6
3098: * "localhost" -> loopback v4/v6
1.334 djm 3099: * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
1.312 djm 3100: */
3101: static const char *
3102: channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
1.336 millert 3103: int is_client, struct ForwardOptions *fwd_opts)
1.312 djm 3104: {
3105: const char *addr = NULL;
3106: int wildcard = 0;
3107:
3108: if (listen_addr == NULL) {
3109: /* No address specified: default to gateway_ports setting */
1.336 millert 3110: if (fwd_opts->gateway_ports)
1.312 djm 3111: wildcard = 1;
1.336 millert 3112: } else if (fwd_opts->gateway_ports || is_client) {
1.312 djm 3113: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
3114: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3115: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
1.336 millert 3116: (!is_client && fwd_opts->gateway_ports == 1)) {
1.312 djm 3117: wildcard = 1;
1.326 djm 3118: /*
3119: * Notify client if they requested a specific listen
3120: * address and it was overridden.
3121: */
3122: if (*listen_addr != '\0' &&
3123: strcmp(listen_addr, "0.0.0.0") != 0 &&
3124: strcmp(listen_addr, "*") != 0) {
3125: packet_send_debug("Forwarding listen address "
3126: "\"%s\" overridden by server "
3127: "GatewayPorts", listen_addr);
3128: }
1.334 djm 3129: } else if (strcmp(listen_addr, "localhost") != 0 ||
3130: strcmp(listen_addr, "127.0.0.1") == 0 ||
3131: strcmp(listen_addr, "::1") == 0) {
3132: /* Accept localhost address when GatewayPorts=yes */
3133: addr = listen_addr;
1.326 djm 3134: }
1.334 djm 3135: } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
3136: strcmp(listen_addr, "::1") == 0) {
3137: /*
3138: * If a specific IPv4/IPv6 localhost address has been
3139: * requested then accept it even if gateway_ports is in
3140: * effect. This allows the client to prefer IPv4 or IPv6.
3141: */
3142: addr = listen_addr;
1.312 djm 3143: }
3144: if (wildcardp != NULL)
3145: *wildcardp = wildcard;
3146: return addr;
3147: }
3148:
1.160 markus 3149: static int
1.336 millert 3150: channel_setup_fwd_listener_tcpip(int type, struct Forward *fwd,
3151: int *allocated_listen_port, struct ForwardOptions *fwd_opts)
1.25 markus 3152: {
1.113 markus 3153: Channel *c;
1.226 djm 3154: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 3155: struct addrinfo hints, *ai, *aitop;
1.212 djm 3156: const char *host, *addr;
1.35 markus 3157: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 3158: in_port_t *lport_p;
1.25 markus 3159:
1.212 djm 3160: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 3161:
1.344 millert 3162: if (is_client && fwd->connect_path != NULL) {
3163: host = fwd->connect_path;
3164: } else {
3165: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
3166: fwd->listen_host : fwd->connect_host;
3167: if (host == NULL) {
3168: error("No forward host name.");
3169: return 0;
3170: }
3171: if (strlen(host) >= NI_MAXHOST) {
3172: error("Forward host name too long.");
3173: return 0;
3174: }
1.87 markus 3175: }
1.25 markus 3176:
1.312 djm 3177: /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
1.336 millert 3178: addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
3179: is_client, fwd_opts);
3180: debug3("%s: type %d wildcard %d addr %s", __func__,
1.212 djm 3181: type, wildcard, (addr == NULL) ? "NULL" : addr);
3182:
3183: /*
1.35 markus 3184: * getaddrinfo returns a loopback address if the hostname is
3185: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 3186: */
1.35 markus 3187: memset(&hints, 0, sizeof(hints));
3188: hints.ai_family = IPv4or6;
1.212 djm 3189: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 3190: hints.ai_socktype = SOCK_STREAM;
1.336 millert 3191: snprintf(strport, sizeof strport, "%d", fwd->listen_port);
1.212 djm 3192: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
3193: if (addr == NULL) {
3194: /* This really shouldn't happen */
3195: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 3196: ssh_gai_strerror(r));
1.212 djm 3197: } else {
1.336 millert 3198: error("%s: getaddrinfo(%.64s): %s", __func__, addr,
1.271 dtucker 3199: ssh_gai_strerror(r));
1.212 djm 3200: }
1.218 markus 3201: return 0;
1.212 djm 3202: }
1.295 djm 3203: if (allocated_listen_port != NULL)
3204: *allocated_listen_port = 0;
1.35 markus 3205: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 3206: switch (ai->ai_family) {
3207: case AF_INET:
3208: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
3209: sin_port;
3210: break;
3211: case AF_INET6:
3212: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
3213: sin6_port;
3214: break;
3215: default:
1.35 markus 3216: continue;
1.295 djm 3217: }
3218: /*
3219: * If allocating a port for -R forwards, then use the
3220: * same port for all address families.
3221: */
1.336 millert 3222: if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
1.295 djm 3223: allocated_listen_port != NULL && *allocated_listen_port > 0)
3224: *lport_p = htons(*allocated_listen_port);
3225:
1.35 markus 3226: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
3227: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.336 millert 3228: error("%s: getnameinfo failed", __func__);
1.35 markus 3229: continue;
3230: }
3231: /* Create a port to listen for the host. */
1.300 dtucker 3232: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3233: if (sock < 0) {
3234: /* this is no error since kernel may not support ipv6 */
3235: verbose("socket: %.100s", strerror(errno));
3236: continue;
3237: }
1.226 djm 3238:
3239: channel_set_reuseaddr(sock);
1.182 stevesk 3240:
1.295 djm 3241: debug("Local forwarding listening on %s port %s.",
3242: ntop, strport);
1.35 markus 3243:
3244: /* Bind the socket to the address. */
3245: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3246: /* address can be in use ipv6 address is already bound */
3247: verbose("bind: %.100s", strerror(errno));
3248: close(sock);
3249: continue;
3250: }
3251: /* Start listening for connections on the socket. */
1.199 markus 3252: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3253: error("listen: %.100s", strerror(errno));
3254: close(sock);
3255: continue;
3256: }
1.295 djm 3257:
3258: /*
1.336 millert 3259: * fwd->listen_port == 0 requests a dynamically allocated port -
1.295 djm 3260: * record what we got.
3261: */
1.336 millert 3262: if (type == SSH_CHANNEL_RPORT_LISTENER && fwd->listen_port == 0 &&
1.295 djm 3263: allocated_listen_port != NULL &&
3264: *allocated_listen_port == 0) {
1.350 djm 3265: *allocated_listen_port = get_local_port(sock);
1.295 djm 3266: debug("Allocated listen port %d",
3267: *allocated_listen_port);
3268: }
3269:
1.35 markus 3270: /* Allocate a channel number for the socket. */
1.121 markus 3271: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 3272: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 3273: 0, "port listener", 1);
1.293 djm 3274: c->path = xstrdup(host);
1.336 millert 3275: c->host_port = fwd->connect_port;
1.312 djm 3276: c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
1.336 millert 3277: if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
1.315 markus 3278: !(datafellows & SSH_BUG_DYNAMIC_RPORT))
3279: c->listening_port = *allocated_listen_port;
3280: else
1.336 millert 3281: c->listening_port = fwd->listen_port;
1.35 markus 3282: success = 1;
3283: }
3284: if (success == 0)
1.336 millert 3285: error("%s: cannot listen to port: %d", __func__,
3286: fwd->listen_port);
1.35 markus 3287: freeaddrinfo(aitop);
1.87 markus 3288: return success;
1.25 markus 3289: }
1.1 deraadt 3290:
1.336 millert 3291: static int
3292: channel_setup_fwd_listener_streamlocal(int type, struct Forward *fwd,
3293: struct ForwardOptions *fwd_opts)
3294: {
3295: struct sockaddr_un sunaddr;
3296: const char *path;
3297: Channel *c;
3298: int port, sock;
3299: mode_t omask;
3300:
3301: switch (type) {
3302: case SSH_CHANNEL_UNIX_LISTENER:
3303: if (fwd->connect_path != NULL) {
3304: if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
3305: error("Local connecting path too long: %s",
3306: fwd->connect_path);
3307: return 0;
3308: }
3309: path = fwd->connect_path;
3310: port = PORT_STREAMLOCAL;
3311: } else {
3312: if (fwd->connect_host == NULL) {
3313: error("No forward host name.");
3314: return 0;
3315: }
3316: if (strlen(fwd->connect_host) >= NI_MAXHOST) {
3317: error("Forward host name too long.");
3318: return 0;
3319: }
3320: path = fwd->connect_host;
3321: port = fwd->connect_port;
3322: }
3323: break;
3324: case SSH_CHANNEL_RUNIX_LISTENER:
3325: path = fwd->listen_path;
3326: port = PORT_STREAMLOCAL;
3327: break;
3328: default:
3329: error("%s: unexpected channel type %d", __func__, type);
3330: return 0;
3331: }
3332:
3333: if (fwd->listen_path == NULL) {
3334: error("No forward path name.");
3335: return 0;
3336: }
3337: if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
3338: error("Local listening path too long: %s", fwd->listen_path);
3339: return 0;
3340: }
3341:
3342: debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
3343:
3344: /* Start a Unix domain listener. */
3345: omask = umask(fwd_opts->streamlocal_bind_mask);
3346: sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
3347: fwd_opts->streamlocal_bind_unlink);
3348: umask(omask);
3349: if (sock < 0)
3350: return 0;
3351:
3352: debug("Local forwarding listening on path %s.", fwd->listen_path);
3353:
3354: /* Allocate a channel number for the socket. */
3355: c = channel_new("unix listener", type, sock, sock, -1,
3356: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3357: 0, "unix listener", 1);
3358: c->path = xstrdup(path);
3359: c->host_port = port;
3360: c->listening_port = PORT_STREAMLOCAL;
3361: c->listening_addr = xstrdup(fwd->listen_path);
3362: return 1;
3363: }
3364:
3365: static int
3366: channel_cancel_rport_listener_tcpip(const char *host, u_short port)
1.202 djm 3367: {
1.209 avsm 3368: u_int i;
3369: int found = 0;
1.202 djm 3370:
1.213 deraadt 3371: for (i = 0; i < channels_alloc; i++) {
1.202 djm 3372: Channel *c = channels[i];
1.312 djm 3373: if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3374: continue;
3375: if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3376: debug2("%s: close channel %d", __func__, i);
3377: channel_free(c);
3378: found = 1;
3379: }
3380: }
3381:
3382: return (found);
3383: }
3384:
1.336 millert 3385: static int
3386: channel_cancel_rport_listener_streamlocal(const char *path)
3387: {
3388: u_int i;
3389: int found = 0;
3390:
3391: for (i = 0; i < channels_alloc; i++) {
3392: Channel *c = channels[i];
3393: if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3394: continue;
3395: if (c->path == NULL)
3396: continue;
3397: if (strcmp(c->path, path) == 0) {
3398: debug2("%s: close channel %d", __func__, i);
3399: channel_free(c);
3400: found = 1;
3401: }
3402: }
3403:
3404: return (found);
3405: }
3406:
1.312 djm 3407: int
1.336 millert 3408: channel_cancel_rport_listener(struct Forward *fwd)
3409: {
3410: if (fwd->listen_path != NULL)
3411: return channel_cancel_rport_listener_streamlocal(fwd->listen_path);
3412: else
3413: return channel_cancel_rport_listener_tcpip(fwd->listen_host, fwd->listen_port);
3414: }
3415:
3416: static int
3417: channel_cancel_lport_listener_tcpip(const char *lhost, u_short lport,
3418: int cport, struct ForwardOptions *fwd_opts)
1.312 djm 3419: {
3420: u_int i;
3421: int found = 0;
1.336 millert 3422: const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
1.202 djm 3423:
1.312 djm 3424: for (i = 0; i < channels_alloc; i++) {
3425: Channel *c = channels[i];
3426: if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
3427: continue;
1.313 markus 3428: if (c->listening_port != lport)
1.312 djm 3429: continue;
1.313 markus 3430: if (cport == CHANNEL_CANCEL_PORT_STATIC) {
3431: /* skip dynamic forwardings */
3432: if (c->host_port == 0)
3433: continue;
3434: } else {
3435: if (c->host_port != cport)
3436: continue;
3437: }
1.312 djm 3438: if ((c->listening_addr == NULL && addr != NULL) ||
3439: (c->listening_addr != NULL && addr == NULL))
3440: continue;
3441: if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
1.210 djm 3442: debug2("%s: close channel %d", __func__, i);
1.202 djm 3443: channel_free(c);
3444: found = 1;
3445: }
3446: }
3447:
3448: return (found);
3449: }
3450:
1.336 millert 3451: static int
3452: channel_cancel_lport_listener_streamlocal(const char *path)
3453: {
3454: u_int i;
3455: int found = 0;
3456:
3457: if (path == NULL) {
3458: error("%s: no path specified.", __func__);
3459: return 0;
3460: }
3461:
3462: for (i = 0; i < channels_alloc; i++) {
3463: Channel *c = channels[i];
3464: if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
3465: continue;
3466: if (c->listening_addr == NULL)
3467: continue;
3468: if (strcmp(c->listening_addr, path) == 0) {
3469: debug2("%s: close channel %d", __func__, i);
3470: channel_free(c);
3471: found = 1;
3472: }
3473: }
3474:
3475: return (found);
3476: }
3477:
3478: int
3479: channel_cancel_lport_listener(struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
3480: {
3481: if (fwd->listen_path != NULL)
3482: return channel_cancel_lport_listener_streamlocal(fwd->listen_path);
3483: else
3484: return channel_cancel_lport_listener_tcpip(fwd->listen_host, fwd->listen_port, cport, fwd_opts);
3485: }
3486:
1.160 markus 3487: /* protocol local port fwd, used by ssh (and sshd in v1) */
3488: int
1.336 millert 3489: channel_setup_local_fwd_listener(struct Forward *fwd, struct ForwardOptions *fwd_opts)
1.160 markus 3490: {
1.336 millert 3491: if (fwd->listen_path != NULL) {
3492: return channel_setup_fwd_listener_streamlocal(
3493: SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
3494: } else {
3495: return channel_setup_fwd_listener_tcpip(SSH_CHANNEL_PORT_LISTENER,
3496: fwd, NULL, fwd_opts);
3497: }
1.160 markus 3498: }
3499:
3500: /* protocol v2 remote port fwd, used by sshd */
3501: int
1.336 millert 3502: channel_setup_remote_fwd_listener(struct Forward *fwd,
3503: int *allocated_listen_port, struct ForwardOptions *fwd_opts)
1.160 markus 3504: {
1.336 millert 3505: if (fwd->listen_path != NULL) {
3506: return channel_setup_fwd_listener_streamlocal(
3507: SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
3508: } else {
3509: return channel_setup_fwd_listener_tcpip(
3510: SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
3511: fwd_opts);
3512: }
1.160 markus 3513: }
3514:
1.27 markus 3515: /*
1.312 djm 3516: * Translate the requested rfwd listen host to something usable for
3517: * this server.
3518: */
3519: static const char *
3520: channel_rfwd_bind_host(const char *listen_host)
3521: {
3522: if (listen_host == NULL) {
3523: if (datafellows & SSH_BUG_RFWD_ADDR)
3524: return "127.0.0.1";
3525: else
3526: return "localhost";
3527: } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3528: if (datafellows & SSH_BUG_RFWD_ADDR)
3529: return "0.0.0.0";
3530: else
3531: return "";
3532: } else
3533: return listen_host;
3534: }
3535:
3536: /*
1.27 markus 3537: * Initiate forwarding of connections to port "port" on remote host through
3538: * the secure channel to host:port from local side.
1.315 markus 3539: * Returns handle (index) for updating the dynamic listen port with
3540: * channel_update_permitted_opens().
1.27 markus 3541: */
1.253 markus 3542: int
1.336 millert 3543: channel_request_remote_forwarding(struct Forward *fwd)
1.25 markus 3544: {
1.315 markus 3545: int type, success = 0, idx = -1;
1.73 markus 3546:
1.25 markus 3547: /* Send the forward request to the remote side. */
1.44 markus 3548: if (compat20) {
3549: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1.336 millert 3550: if (fwd->listen_path != NULL) {
3551: packet_put_cstring("streamlocal-forward@openssh.com");
3552: packet_put_char(1); /* boolean: want reply */
3553: packet_put_cstring(fwd->listen_path);
3554: } else {
3555: packet_put_cstring("tcpip-forward");
3556: packet_put_char(1); /* boolean: want reply */
3557: packet_put_cstring(channel_rfwd_bind_host(fwd->listen_host));
3558: packet_put_int(fwd->listen_port);
3559: }
1.73 markus 3560: packet_send();
3561: packet_write_wait();
3562: /* Assume that server accepts the request */
3563: success = 1;
1.336 millert 3564: } else if (fwd->listen_path == NULL) {
1.44 markus 3565: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.336 millert 3566: packet_put_int(fwd->listen_port);
3567: packet_put_cstring(fwd->connect_host);
3568: packet_put_int(fwd->connect_port);
1.44 markus 3569: packet_send();
3570: packet_write_wait();
1.73 markus 3571:
3572: /* Wait for response from the remote side. */
1.153 markus 3573: type = packet_read();
1.73 markus 3574: switch (type) {
3575: case SSH_SMSG_SUCCESS:
3576: success = 1;
3577: break;
3578: case SSH_SMSG_FAILURE:
3579: break;
3580: default:
3581: /* Unknown packet */
3582: packet_disconnect("Protocol error for port forward request:"
3583: "received packet type %d.", type);
3584: }
1.336 millert 3585: } else {
3586: logit("Warning: Server does not support remote stream local forwarding.");
1.73 markus 3587: }
3588: if (success) {
1.305 djm 3589: /* Record that connection to this host/port is permitted. */
1.342 deraadt 3590: permitted_opens = xreallocarray(permitted_opens,
1.305 djm 3591: num_permitted_opens + 1, sizeof(*permitted_opens));
1.315 markus 3592: idx = num_permitted_opens++;
1.336 millert 3593: if (fwd->connect_path != NULL) {
3594: permitted_opens[idx].host_to_connect =
3595: xstrdup(fwd->connect_path);
3596: permitted_opens[idx].port_to_connect =
3597: PORT_STREAMLOCAL;
3598: } else {
3599: permitted_opens[idx].host_to_connect =
3600: xstrdup(fwd->connect_host);
3601: permitted_opens[idx].port_to_connect =
3602: fwd->connect_port;
3603: }
3604: if (fwd->listen_path != NULL) {
3605: permitted_opens[idx].listen_host = NULL;
3606: permitted_opens[idx].listen_path =
3607: xstrdup(fwd->listen_path);
3608: permitted_opens[idx].listen_port = PORT_STREAMLOCAL;
3609: } else {
3610: permitted_opens[idx].listen_host =
3611: fwd->listen_host ? xstrdup(fwd->listen_host) : NULL;
3612: permitted_opens[idx].listen_path = NULL;
3613: permitted_opens[idx].listen_port = fwd->listen_port;
3614: }
1.354 ! markus 3615: permitted_opens[idx].downstream = NULL;
1.44 markus 3616: }
1.315 markus 3617: return (idx);
1.1 deraadt 3618: }
3619:
1.333 markus 3620: static int
3621: open_match(ForwardPermission *allowed_open, const char *requestedhost,
1.336 millert 3622: int requestedport)
1.333 markus 3623: {
3624: if (allowed_open->host_to_connect == NULL)
3625: return 0;
3626: if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
3627: allowed_open->port_to_connect != requestedport)
3628: return 0;
1.351 dtucker 3629: if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
3630: strcmp(allowed_open->host_to_connect, requestedhost) != 0)
1.333 markus 3631: return 0;
3632: return 1;
3633: }
3634:
3635: /*
1.336 millert 3636: * Note that in the listen host/port case
1.333 markus 3637: * we don't support FWD_PERMIT_ANY_PORT and
3638: * need to translate between the configured-host (listen_host)
3639: * and what we've sent to the remote server (channel_rfwd_bind_host)
3640: */
3641: static int
1.336 millert 3642: open_listen_match_tcpip(ForwardPermission *allowed_open,
3643: const char *requestedhost, u_short requestedport, int translate)
1.333 markus 3644: {
3645: const char *allowed_host;
3646:
3647: if (allowed_open->host_to_connect == NULL)
3648: return 0;
3649: if (allowed_open->listen_port != requestedport)
3650: return 0;
1.335 djm 3651: if (!translate && allowed_open->listen_host == NULL &&
3652: requestedhost == NULL)
3653: return 1;
1.333 markus 3654: allowed_host = translate ?
3655: channel_rfwd_bind_host(allowed_open->listen_host) :
3656: allowed_open->listen_host;
3657: if (allowed_host == NULL ||
3658: strcmp(allowed_host, requestedhost) != 0)
3659: return 0;
3660: return 1;
3661: }
3662:
1.336 millert 3663: static int
3664: open_listen_match_streamlocal(ForwardPermission *allowed_open,
3665: const char *requestedpath)
3666: {
3667: if (allowed_open->host_to_connect == NULL)
3668: return 0;
3669: if (allowed_open->listen_port != PORT_STREAMLOCAL)
3670: return 0;
3671: if (allowed_open->listen_path == NULL ||
3672: strcmp(allowed_open->listen_path, requestedpath) != 0)
3673: return 0;
3674: return 1;
3675: }
3676:
1.27 markus 3677: /*
1.208 deraadt 3678: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 3679: * local side.
3680: */
1.336 millert 3681: static int
3682: channel_request_rforward_cancel_tcpip(const char *host, u_short port)
1.202 djm 3683: {
3684: int i;
3685:
3686: if (!compat20)
1.312 djm 3687: return -1;
1.202 djm 3688:
3689: for (i = 0; i < num_permitted_opens; i++) {
1.336 millert 3690: if (open_listen_match_tcpip(&permitted_opens[i], host, port, 0))
1.202 djm 3691: break;
3692: }
3693: if (i >= num_permitted_opens) {
3694: debug("%s: requested forward not found", __func__);
1.312 djm 3695: return -1;
1.202 djm 3696: }
3697: packet_start(SSH2_MSG_GLOBAL_REQUEST);
3698: packet_put_cstring("cancel-tcpip-forward");
3699: packet_put_char(0);
1.312 djm 3700: packet_put_cstring(channel_rfwd_bind_host(host));
1.202 djm 3701: packet_put_int(port);
3702: packet_send();
3703:
1.336 millert 3704: permitted_opens[i].listen_port = 0;
1.333 markus 3705: permitted_opens[i].port_to_connect = 0;
1.336 millert 3706: free(permitted_opens[i].host_to_connect);
3707: permitted_opens[i].host_to_connect = NULL;
3708: free(permitted_opens[i].listen_host);
3709: permitted_opens[i].listen_host = NULL;
3710: permitted_opens[i].listen_path = NULL;
1.354 ! markus 3711: permitted_opens[i].downstream = NULL;
1.336 millert 3712:
3713: return 0;
3714: }
3715:
3716: /*
3717: * Request cancellation of remote forwarding of Unix domain socket
3718: * path from local side.
3719: */
3720: static int
3721: channel_request_rforward_cancel_streamlocal(const char *path)
3722: {
3723: int i;
3724:
3725: if (!compat20)
3726: return -1;
3727:
3728: for (i = 0; i < num_permitted_opens; i++) {
3729: if (open_listen_match_streamlocal(&permitted_opens[i], path))
3730: break;
3731: }
3732: if (i >= num_permitted_opens) {
3733: debug("%s: requested forward not found", __func__);
3734: return -1;
3735: }
3736: packet_start(SSH2_MSG_GLOBAL_REQUEST);
3737: packet_put_cstring("cancel-streamlocal-forward@openssh.com");
3738: packet_put_char(0);
3739: packet_put_cstring(path);
3740: packet_send();
3741:
1.202 djm 3742: permitted_opens[i].listen_port = 0;
1.336 millert 3743: permitted_opens[i].port_to_connect = 0;
1.321 djm 3744: free(permitted_opens[i].host_to_connect);
1.202 djm 3745: permitted_opens[i].host_to_connect = NULL;
1.333 markus 3746: permitted_opens[i].listen_host = NULL;
1.336 millert 3747: free(permitted_opens[i].listen_path);
3748: permitted_opens[i].listen_path = NULL;
1.354 ! markus 3749: permitted_opens[i].downstream = NULL;
1.312 djm 3750:
3751: return 0;
1.202 djm 3752: }
3753:
3754: /*
1.336 millert 3755: * Request cancellation of remote forwarding of a connection from local side.
3756: */
3757: int
3758: channel_request_rforward_cancel(struct Forward *fwd)
3759: {
3760: if (fwd->listen_path != NULL) {
3761: return (channel_request_rforward_cancel_streamlocal(
3762: fwd->listen_path));
3763: } else {
3764: return (channel_request_rforward_cancel_tcpip(fwd->listen_host,
3765: fwd->listen_port ? fwd->listen_port : fwd->allocated_port));
3766: }
3767: }
3768:
3769: /*
1.27 markus 3770: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3771: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 3772: * message if there was an error).
1.27 markus 3773: */
1.253 markus 3774: int
1.336 millert 3775: channel_input_port_forward_request(int is_root, struct ForwardOptions *fwd_opts)
1.1 deraadt 3776: {
1.253 markus 3777: int success = 0;
1.336 millert 3778: struct Forward fwd;
1.1 deraadt 3779:
1.25 markus 3780: /* Get arguments from the packet. */
1.336 millert 3781: memset(&fwd, 0, sizeof(fwd));
3782: fwd.listen_port = packet_get_int();
3783: fwd.connect_host = packet_get_string(NULL);
3784: fwd.connect_port = packet_get_int();
1.25 markus 3785:
1.27 markus 3786: /*
3787: * Check that an unprivileged user is not trying to forward a
3788: * privileged port.
3789: */
1.336 millert 3790: if (fwd.listen_port < IPPORT_RESERVED && !is_root)
1.192 markus 3791: packet_disconnect(
3792: "Requested forwarding of port %d but user is not root.",
1.336 millert 3793: fwd.listen_port);
3794: if (fwd.connect_port == 0)
1.192 markus 3795: packet_disconnect("Dynamic forwarding denied.");
3796:
1.73 markus 3797: /* Initiate forwarding */
1.336 millert 3798: success = channel_setup_local_fwd_listener(&fwd, fwd_opts);
1.25 markus 3799:
3800: /* Free the argument string. */
1.336 millert 3801: free(fwd.connect_host);
1.253 markus 3802:
3803: return (success ? 0 : -1);
1.1 deraadt 3804: }
3805:
1.99 markus 3806: /*
3807: * Permits opening to any host/port if permitted_opens[] is empty. This is
3808: * usually called by the server, because the user could connect to any port
3809: * anyway, and the server has no way to know but to trust the client anyway.
3810: */
3811: void
1.142 itojun 3812: channel_permit_all_opens(void)
1.99 markus 3813: {
3814: if (num_permitted_opens == 0)
3815: all_opens_permitted = 1;
3816: }
3817:
1.101 markus 3818: void
1.99 markus 3819: channel_add_permitted_opens(char *host, int port)
3820: {
3821: debug("allow port forwarding to host %s port %d", host, port);
3822:
1.342 deraadt 3823: permitted_opens = xreallocarray(permitted_opens,
1.305 djm 3824: num_permitted_opens + 1, sizeof(*permitted_opens));
1.99 markus 3825: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3826: permitted_opens[num_permitted_opens].port_to_connect = port;
1.333 markus 3827: permitted_opens[num_permitted_opens].listen_host = NULL;
1.336 millert 3828: permitted_opens[num_permitted_opens].listen_path = NULL;
1.333 markus 3829: permitted_opens[num_permitted_opens].listen_port = 0;
1.354 ! markus 3830: permitted_opens[num_permitted_opens].downstream = NULL;
1.99 markus 3831: num_permitted_opens++;
3832:
3833: all_opens_permitted = 0;
1.315 markus 3834: }
3835:
3836: /*
3837: * Update the listen port for a dynamic remote forward, after
3838: * the actual 'newport' has been allocated. If 'newport' < 0 is
3839: * passed then they entry will be invalidated.
3840: */
3841: void
3842: channel_update_permitted_opens(int idx, int newport)
3843: {
3844: if (idx < 0 || idx >= num_permitted_opens) {
3845: debug("channel_update_permitted_opens: index out of range:"
3846: " %d num_permitted_opens %d", idx, num_permitted_opens);
3847: return;
3848: }
3849: debug("%s allowed port %d for forwarding to host %s port %d",
3850: newport > 0 ? "Updating" : "Removing",
3851: newport,
3852: permitted_opens[idx].host_to_connect,
3853: permitted_opens[idx].port_to_connect);
3854: if (newport >= 0) {
3855: permitted_opens[idx].listen_port =
3856: (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3857: } else {
3858: permitted_opens[idx].listen_port = 0;
3859: permitted_opens[idx].port_to_connect = 0;
1.321 djm 3860: free(permitted_opens[idx].host_to_connect);
1.315 markus 3861: permitted_opens[idx].host_to_connect = NULL;
1.333 markus 3862: free(permitted_opens[idx].listen_host);
3863: permitted_opens[idx].listen_host = NULL;
1.336 millert 3864: free(permitted_opens[idx].listen_path);
3865: permitted_opens[idx].listen_path = NULL;
1.315 markus 3866: }
1.99 markus 3867: }
3868:
1.258 dtucker 3869: int
1.257 dtucker 3870: channel_add_adm_permitted_opens(char *host, int port)
3871: {
1.258 dtucker 3872: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 3873:
1.342 deraadt 3874: permitted_adm_opens = xreallocarray(permitted_adm_opens,
1.305 djm 3875: num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
1.257 dtucker 3876: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3877: = xstrdup(host);
3878: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.333 markus 3879: permitted_adm_opens[num_adm_permitted_opens].listen_host = NULL;
1.336 millert 3880: permitted_adm_opens[num_adm_permitted_opens].listen_path = NULL;
1.333 markus 3881: permitted_adm_opens[num_adm_permitted_opens].listen_port = 0;
1.258 dtucker 3882: return ++num_adm_permitted_opens;
1.257 dtucker 3883: }
3884:
3885: void
1.316 dtucker 3886: channel_disable_adm_local_opens(void)
3887: {
1.319 djm 3888: channel_clear_adm_permitted_opens();
1.343 dtucker 3889: permitted_adm_opens = xcalloc(sizeof(*permitted_adm_opens), 1);
1.319 djm 3890: permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3891: num_adm_permitted_opens = 1;
1.316 dtucker 3892: }
3893:
3894: void
1.99 markus 3895: channel_clear_permitted_opens(void)
3896: {
3897: int i;
3898:
1.333 markus 3899: for (i = 0; i < num_permitted_opens; i++) {
1.321 djm 3900: free(permitted_opens[i].host_to_connect);
1.333 markus 3901: free(permitted_opens[i].listen_host);
1.336 millert 3902: free(permitted_opens[i].listen_path);
1.333 markus 3903: }
1.321 djm 3904: free(permitted_opens);
3905: permitted_opens = NULL;
1.99 markus 3906: num_permitted_opens = 0;
1.257 dtucker 3907: }
3908:
3909: void
3910: channel_clear_adm_permitted_opens(void)
3911: {
3912: int i;
1.99 markus 3913:
1.333 markus 3914: for (i = 0; i < num_adm_permitted_opens; i++) {
1.321 djm 3915: free(permitted_adm_opens[i].host_to_connect);
1.333 markus 3916: free(permitted_adm_opens[i].listen_host);
1.336 millert 3917: free(permitted_adm_opens[i].listen_path);
1.333 markus 3918: }
1.321 djm 3919: free(permitted_adm_opens);
3920: permitted_adm_opens = NULL;
1.257 dtucker 3921: num_adm_permitted_opens = 0;
1.278 dtucker 3922: }
3923:
3924: void
3925: channel_print_adm_permitted_opens(void)
3926: {
1.286 djm 3927: int i;
1.278 dtucker 3928:
1.290 stevesk 3929: printf("permitopen");
1.288 stevesk 3930: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3931: printf(" any\n");
1.288 stevesk 3932: return;
3933: }
1.278 dtucker 3934: for (i = 0; i < num_adm_permitted_opens; i++)
1.316 dtucker 3935: if (permitted_adm_opens[i].host_to_connect == NULL)
3936: printf(" none");
3937: else
1.278 dtucker 3938: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3939: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3940: printf("\n");
1.99 markus 3941: }
3942:
1.314 dtucker 3943: /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3944: int
3945: permitopen_port(const char *p)
3946: {
3947: int port;
3948:
3949: if (strcmp(p, "*") == 0)
3950: return FWD_PERMIT_ANY_PORT;
3951: if ((port = a2port(p)) > 0)
3952: return port;
3953: return -1;
3954: }
3955:
1.276 djm 3956: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3957: static int
1.276 djm 3958: connect_next(struct channel_connect *cctx)
1.41 markus 3959: {
1.276 djm 3960: int sock, saved_errno;
1.336 millert 3961: struct sockaddr_un *sunaddr;
1.352 deraadt 3962: char ntop[NI_MAXHOST], strport[MAXIMUM(NI_MAXSERV,sizeof(sunaddr->sun_path))];
1.41 markus 3963:
1.276 djm 3964: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
1.336 millert 3965: switch (cctx->ai->ai_family) {
3966: case AF_UNIX:
3967: /* unix:pathname instead of host:port */
3968: sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
3969: strlcpy(ntop, "unix", sizeof(ntop));
3970: strlcpy(strport, sunaddr->sun_path, sizeof(strport));
3971: break;
3972: case AF_INET:
3973: case AF_INET6:
3974: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3975: ntop, sizeof(ntop), strport, sizeof(strport),
3976: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3977: error("connect_next: getnameinfo failed");
3978: continue;
3979: }
3980: break;
3981: default:
1.41 markus 3982: continue;
3983: }
1.300 dtucker 3984: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3985: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3986: if (cctx->ai->ai_next == NULL)
1.186 djm 3987: error("socket: %.100s", strerror(errno));
3988: else
3989: verbose("socket: %.100s", strerror(errno));
1.41 markus 3990: continue;
3991: }
1.205 djm 3992: if (set_nonblock(sock) == -1)
3993: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3994: if (connect(sock, cctx->ai->ai_addr,
3995: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3996: debug("connect_next: host %.100s ([%.100s]:%s): "
3997: "%.100s", cctx->host, ntop, strport,
1.41 markus 3998: strerror(errno));
1.276 djm 3999: saved_errno = errno;
1.41 markus 4000: close(sock);
1.276 djm 4001: errno = saved_errno;
1.89 stevesk 4002: continue; /* fail -- try next */
1.41 markus 4003: }
1.336 millert 4004: if (cctx->ai->ai_family != AF_UNIX)
4005: set_nodelay(sock);
1.276 djm 4006: debug("connect_next: host %.100s ([%.100s]:%s) "
4007: "in progress, fd=%d", cctx->host, ntop, strport, sock);
4008: cctx->ai = cctx->ai->ai_next;
4009: return sock;
4010: }
4011: return -1;
4012: }
1.41 markus 4013:
1.276 djm 4014: static void
4015: channel_connect_ctx_free(struct channel_connect *cctx)
4016: {
1.321 djm 4017: free(cctx->host);
1.336 millert 4018: if (cctx->aitop) {
4019: if (cctx->aitop->ai_family == AF_UNIX)
4020: free(cctx->aitop);
4021: else
4022: freeaddrinfo(cctx->aitop);
4023: }
1.329 tedu 4024: memset(cctx, 0, sizeof(*cctx));
1.276 djm 4025: }
4026:
1.336 millert 4027: /* Return CONNECTING channel to remote host:port or local socket path */
1.276 djm 4028: static Channel *
1.336 millert 4029: connect_to(const char *name, int port, char *ctype, char *rname)
1.276 djm 4030: {
4031: struct addrinfo hints;
4032: int gaierr;
4033: int sock = -1;
4034: char strport[NI_MAXSERV];
4035: struct channel_connect cctx;
4036: Channel *c;
4037:
1.284 djm 4038: memset(&cctx, 0, sizeof(cctx));
1.336 millert 4039:
4040: if (port == PORT_STREAMLOCAL) {
4041: struct sockaddr_un *sunaddr;
4042: struct addrinfo *ai;
4043:
4044: if (strlen(name) > sizeof(sunaddr->sun_path)) {
4045: error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
4046: return (NULL);
4047: }
4048:
4049: /*
4050: * Fake up a struct addrinfo for AF_UNIX connections.
4051: * channel_connect_ctx_free() must check ai_family
4052: * and use free() not freeaddirinfo() for AF_UNIX.
4053: */
4054: ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
4055: memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
4056: ai->ai_addr = (struct sockaddr *)(ai + 1);
4057: ai->ai_addrlen = sizeof(*sunaddr);
4058: ai->ai_family = AF_UNIX;
4059: ai->ai_socktype = SOCK_STREAM;
4060: ai->ai_protocol = PF_UNSPEC;
4061: sunaddr = (struct sockaddr_un *)ai->ai_addr;
4062: sunaddr->sun_family = AF_UNIX;
4063: strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
4064: cctx.aitop = ai;
4065: } else {
4066: memset(&hints, 0, sizeof(hints));
4067: hints.ai_family = IPv4or6;
4068: hints.ai_socktype = SOCK_STREAM;
4069: snprintf(strport, sizeof strport, "%d", port);
4070: if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop)) != 0) {
4071: error("connect_to %.100s: unknown host (%s)", name,
4072: ssh_gai_strerror(gaierr));
4073: return NULL;
4074: }
1.41 markus 4075: }
1.276 djm 4076:
1.336 millert 4077: cctx.host = xstrdup(name);
1.276 djm 4078: cctx.port = port;
4079: cctx.ai = cctx.aitop;
4080:
4081: if ((sock = connect_next(&cctx)) == -1) {
4082: error("connect to %.100s port %d failed: %s",
1.336 millert 4083: name, port, strerror(errno));
1.276 djm 4084: channel_connect_ctx_free(&cctx);
4085: return NULL;
1.41 markus 4086: }
1.276 djm 4087: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
4088: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
4089: c->connect_ctx = cctx;
4090: return c;
1.41 markus 4091: }
1.99 markus 4092:
1.354 ! markus 4093: /*
! 4094: * returns either the newly connected channel or the downstream channel
! 4095: * that needs to deal with this connection.
! 4096: */
1.276 djm 4097: Channel *
1.333 markus 4098: channel_connect_by_listen_address(const char *listen_host,
4099: u_short listen_port, char *ctype, char *rname)
1.73 markus 4100: {
4101: int i;
1.99 markus 4102:
1.276 djm 4103: for (i = 0; i < num_permitted_opens; i++) {
1.336 millert 4104: if (open_listen_match_tcpip(&permitted_opens[i], listen_host,
1.333 markus 4105: listen_port, 1)) {
1.354 ! markus 4106: if (permitted_opens[i].downstream)
! 4107: return permitted_opens[i].downstream;
1.99 markus 4108: return connect_to(
1.73 markus 4109: permitted_opens[i].host_to_connect,
1.276 djm 4110: permitted_opens[i].port_to_connect, ctype, rname);
4111: }
4112: }
1.74 markus 4113: error("WARNING: Server requests forwarding for unknown listen_port %d",
4114: listen_port);
1.276 djm 4115: return NULL;
1.73 markus 4116: }
4117:
1.336 millert 4118: Channel *
4119: channel_connect_by_listen_path(const char *path, char *ctype, char *rname)
4120: {
4121: int i;
4122:
4123: for (i = 0; i < num_permitted_opens; i++) {
4124: if (open_listen_match_streamlocal(&permitted_opens[i], path)) {
4125: return connect_to(
4126: permitted_opens[i].host_to_connect,
4127: permitted_opens[i].port_to_connect, ctype, rname);
4128: }
4129: }
4130: error("WARNING: Server requests forwarding for unknown path %.100s",
4131: path);
4132: return NULL;
4133: }
4134:
1.99 markus 4135: /* Check if connecting to that port is permitted and connect. */
1.276 djm 4136: Channel *
1.336 millert 4137: channel_connect_to_port(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 4138: {
1.257 dtucker 4139: int i, permit, permit_adm = 1;
1.99 markus 4140:
4141: permit = all_opens_permitted;
4142: if (!permit) {
4143: for (i = 0; i < num_permitted_opens; i++)
1.333 markus 4144: if (open_match(&permitted_opens[i], host, port)) {
1.99 markus 4145: permit = 1;
1.333 markus 4146: break;
4147: }
1.257 dtucker 4148: }
1.99 markus 4149:
1.257 dtucker 4150: if (num_adm_permitted_opens > 0) {
4151: permit_adm = 0;
4152: for (i = 0; i < num_adm_permitted_opens; i++)
1.333 markus 4153: if (open_match(&permitted_adm_opens[i], host, port)) {
1.257 dtucker 4154: permit_adm = 1;
1.333 markus 4155: break;
4156: }
1.99 markus 4157: }
1.257 dtucker 4158:
4159: if (!permit || !permit_adm) {
1.188 itojun 4160: logit("Received request to connect to host %.100s port %d, "
1.99 markus 4161: "but the request was denied.", host, port);
1.276 djm 4162: return NULL;
1.99 markus 4163: }
1.276 djm 4164: return connect_to(host, port, ctype, rname);
1.336 millert 4165: }
4166:
4167: /* Check if connecting to that path is permitted and connect. */
4168: Channel *
4169: channel_connect_to_path(const char *path, char *ctype, char *rname)
4170: {
4171: int i, permit, permit_adm = 1;
4172:
4173: permit = all_opens_permitted;
4174: if (!permit) {
4175: for (i = 0; i < num_permitted_opens; i++)
4176: if (open_match(&permitted_opens[i], path, PORT_STREAMLOCAL)) {
4177: permit = 1;
4178: break;
4179: }
4180: }
4181:
4182: if (num_adm_permitted_opens > 0) {
4183: permit_adm = 0;
4184: for (i = 0; i < num_adm_permitted_opens; i++)
4185: if (open_match(&permitted_adm_opens[i], path, PORT_STREAMLOCAL)) {
4186: permit_adm = 1;
4187: break;
4188: }
4189: }
4190:
4191: if (!permit || !permit_adm) {
4192: logit("Received request to connect to path %.100s, "
4193: "but the request was denied.", path);
4194: return NULL;
4195: }
4196: return connect_to(path, PORT_STREAMLOCAL, ctype, rname);
1.204 djm 4197: }
4198:
4199: void
4200: channel_send_window_changes(void)
4201: {
1.209 avsm 4202: u_int i;
1.204 djm 4203: struct winsize ws;
4204:
4205: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 4206: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 4207: channels[i]->type != SSH_CHANNEL_OPEN)
4208: continue;
4209: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
4210: continue;
4211: channel_request_start(i, "window-change", 0);
1.238 deraadt 4212: packet_put_int((u_int)ws.ws_col);
4213: packet_put_int((u_int)ws.ws_row);
4214: packet_put_int((u_int)ws.ws_xpixel);
4215: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 4216: packet_send();
4217: }
1.99 markus 4218: }
4219:
1.121 markus 4220: /* -- X11 forwarding */
1.1 deraadt 4221:
1.27 markus 4222: /*
4223: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 4224: * Returns 0 and a suitable display number for the DISPLAY variable
4225: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 4226: */
1.141 stevesk 4227: int
1.163 stevesk 4228: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 4229: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 4230: {
1.149 markus 4231: Channel *nc = NULL;
1.31 markus 4232: int display_number, sock;
4233: u_short port;
1.35 markus 4234: struct addrinfo hints, *ai, *aitop;
4235: char strport[NI_MAXSERV];
4236: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 4237:
1.224 markus 4238: if (chanids == NULL)
4239: return -1;
4240:
1.33 markus 4241: for (display_number = x11_display_offset;
1.148 deraadt 4242: display_number < MAX_DISPLAYS;
4243: display_number++) {
1.25 markus 4244: port = 6000 + display_number;
1.35 markus 4245: memset(&hints, 0, sizeof(hints));
4246: hints.ai_family = IPv4or6;
1.163 stevesk 4247: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 4248: hints.ai_socktype = SOCK_STREAM;
4249: snprintf(strport, sizeof strport, "%d", port);
4250: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 4251: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 4252: return -1;
1.25 markus 4253: }
1.35 markus 4254: for (ai = aitop; ai; ai = ai->ai_next) {
4255: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
4256: continue;
1.300 dtucker 4257: sock = socket(ai->ai_family, ai->ai_socktype,
4258: ai->ai_protocol);
1.35 markus 4259: if (sock < 0) {
4260: error("socket: %.100s", strerror(errno));
1.203 markus 4261: freeaddrinfo(aitop);
1.141 stevesk 4262: return -1;
1.35 markus 4263: }
1.226 djm 4264: channel_set_reuseaddr(sock);
1.35 markus 4265: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 4266: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 4267: close(sock);
1.183 itojun 4268:
1.35 markus 4269: for (n = 0; n < num_socks; n++) {
4270: close(socks[n]);
4271: }
4272: num_socks = 0;
4273: break;
4274: }
4275: socks[num_socks++] = sock;
4276: if (num_socks == NUM_SOCKS)
4277: break;
1.25 markus 4278: }
1.83 stevesk 4279: freeaddrinfo(aitop);
1.35 markus 4280: if (num_socks > 0)
4281: break;
1.25 markus 4282: }
4283: if (display_number >= MAX_DISPLAYS) {
4284: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 4285: return -1;
1.25 markus 4286: }
4287: /* Start listening for connections on the socket. */
1.35 markus 4288: for (n = 0; n < num_socks; n++) {
4289: sock = socks[n];
1.199 markus 4290: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 4291: error("listen: %.100s", strerror(errno));
4292: close(sock);
1.141 stevesk 4293: return -1;
1.35 markus 4294: }
1.25 markus 4295: }
1.35 markus 4296:
4297: /* Allocate a channel for each socket. */
1.242 djm 4298: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 4299: for (n = 0; n < num_socks; n++) {
4300: sock = socks[n];
1.149 markus 4301: nc = channel_new("x11 listener",
1.51 markus 4302: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
4303: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 4304: 0, "X11 inet listener", 1);
1.167 markus 4305: nc->single_connection = single_connection;
1.224 markus 4306: (*chanids)[n] = nc->self;
1.35 markus 4307: }
1.224 markus 4308: (*chanids)[n] = -1;
1.1 deraadt 4309:
1.141 stevesk 4310: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 4311: *display_numberp = display_number;
4312: return (0);
1.1 deraadt 4313: }
4314:
1.127 itojun 4315: static int
1.77 markus 4316: connect_local_xsocket(u_int dnr)
1.1 deraadt 4317: {
1.25 markus 4318: int sock;
4319: struct sockaddr_un addr;
4320:
1.147 stevesk 4321: sock = socket(AF_UNIX, SOCK_STREAM, 0);
4322: if (sock < 0)
4323: error("socket: %.100s", strerror(errno));
4324: memset(&addr, 0, sizeof(addr));
4325: addr.sun_family = AF_UNIX;
4326: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 4327: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 4328: return sock;
4329: close(sock);
1.25 markus 4330: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
4331: return -1;
1.1 deraadt 4332: }
4333:
1.51 markus 4334: int
4335: x11_connect_display(void)
1.1 deraadt 4336: {
1.248 deraadt 4337: u_int display_number;
1.25 markus 4338: const char *display;
1.51 markus 4339: char buf[1024], *cp;
1.35 markus 4340: struct addrinfo hints, *ai, *aitop;
4341: char strport[NI_MAXSERV];
1.248 deraadt 4342: int gaierr, sock = 0;
1.25 markus 4343:
4344: /* Try to open a socket for the local X server. */
4345: display = getenv("DISPLAY");
4346: if (!display) {
4347: error("DISPLAY not set.");
1.51 markus 4348: return -1;
1.25 markus 4349: }
1.27 markus 4350: /*
4351: * Now we decode the value of the DISPLAY variable and make a
4352: * connection to the real X server.
4353: */
4354:
4355: /*
4356: * Check if it is a unix domain socket. Unix domain displays are in
4357: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
4358: */
1.25 markus 4359: if (strncmp(display, "unix:", 5) == 0 ||
4360: display[0] == ':') {
4361: /* Connect to the unix domain socket. */
1.248 deraadt 4362: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 4363: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 4364: display);
1.51 markus 4365: return -1;
1.25 markus 4366: }
4367: /* Create a socket. */
4368: sock = connect_local_xsocket(display_number);
4369: if (sock < 0)
1.51 markus 4370: return -1;
1.25 markus 4371:
4372: /* OK, we now have a connection to the display. */
1.51 markus 4373: return sock;
1.25 markus 4374: }
1.27 markus 4375: /*
4376: * Connect to an inet socket. The DISPLAY value is supposedly
4377: * hostname:d[.s], where hostname may also be numeric IP address.
4378: */
1.145 stevesk 4379: strlcpy(buf, display, sizeof(buf));
1.25 markus 4380: cp = strchr(buf, ':');
4381: if (!cp) {
4382: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 4383: return -1;
1.25 markus 4384: }
4385: *cp = 0;
1.27 markus 4386: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 4387: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 4388: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 4389: display);
1.51 markus 4390: return -1;
1.25 markus 4391: }
1.35 markus 4392:
4393: /* Look up the host address */
4394: memset(&hints, 0, sizeof(hints));
4395: hints.ai_family = IPv4or6;
4396: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 4397: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 4398: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 4399: error("%.100s: unknown host. (%s)", buf,
4400: ssh_gai_strerror(gaierr));
1.51 markus 4401: return -1;
1.25 markus 4402: }
1.35 markus 4403: for (ai = aitop; ai; ai = ai->ai_next) {
4404: /* Create a socket. */
1.300 dtucker 4405: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 4406: if (sock < 0) {
1.194 markus 4407: debug2("socket: %.100s", strerror(errno));
1.41 markus 4408: continue;
4409: }
4410: /* Connect it to the display. */
4411: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 4412: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 4413: 6000 + display_number, strerror(errno));
4414: close(sock);
4415: continue;
4416: }
4417: /* Success */
4418: break;
1.35 markus 4419: }
4420: freeaddrinfo(aitop);
4421: if (!ai) {
1.248 deraadt 4422: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 4423: strerror(errno));
1.51 markus 4424: return -1;
1.25 markus 4425: }
1.162 stevesk 4426: set_nodelay(sock);
1.51 markus 4427: return sock;
4428: }
4429:
4430: /*
4431: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
4432: * the remote channel number. We should do whatever we want, and respond
4433: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
4434: */
4435:
1.259 stevesk 4436: /* ARGSUSED */
1.339 markus 4437: int
1.154 markus 4438: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 4439: {
1.113 markus 4440: Channel *c = NULL;
4441: int remote_id, sock = 0;
1.51 markus 4442: char *remote_host;
1.25 markus 4443:
1.113 markus 4444: debug("Received X11 open request.");
1.51 markus 4445:
1.113 markus 4446: remote_id = packet_get_int();
1.121 markus 4447:
4448: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 4449: remote_host = packet_get_string(NULL);
1.51 markus 4450: } else {
4451: remote_host = xstrdup("unknown (remote did not supply name)");
4452: }
1.152 markus 4453: packet_check_eom();
1.25 markus 4454:
1.51 markus 4455: /* Obtain a connection to the real X display. */
4456: sock = x11_connect_display();
1.113 markus 4457: if (sock != -1) {
4458: /* Allocate a channel for this connection. */
4459: c = channel_new("connected x11 socket",
4460: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
4461: remote_host, 1);
1.167 markus 4462: c->remote_id = remote_id;
4463: c->force_drain = 1;
1.113 markus 4464: }
1.321 djm 4465: free(remote_host);
1.113 markus 4466: if (c == NULL) {
1.51 markus 4467: /* Send refusal to the remote host. */
4468: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 4469: packet_put_int(remote_id);
1.51 markus 4470: } else {
4471: /* Send a confirmation to the remote host. */
4472: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 4473: packet_put_int(remote_id);
4474: packet_put_int(c->self);
1.51 markus 4475: }
1.113 markus 4476: packet_send();
1.339 markus 4477: return 0;
1.72 markus 4478: }
4479:
4480: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 4481: /* ARGSUSED */
1.339 markus 4482: int
1.154 markus 4483: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 4484: {
4485: int rchan = packet_get_int();
1.180 deraadt 4486:
1.143 deraadt 4487: switch (type) {
1.72 markus 4488: case SSH_SMSG_AGENT_OPEN:
4489: error("Warning: ssh server tried agent forwarding.");
4490: break;
4491: case SSH_SMSG_X11_OPEN:
4492: error("Warning: ssh server tried X11 forwarding.");
4493: break;
4494: default:
1.154 markus 4495: error("deny_input_open: type %d", type);
1.72 markus 4496: break;
4497: }
1.230 stevesk 4498: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 4499: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
4500: packet_put_int(rchan);
4501: packet_send();
1.339 markus 4502: return 0;
1.1 deraadt 4503: }
4504:
1.27 markus 4505: /*
4506: * Requests forwarding of X11 connections, generates fake authentication
4507: * data, and enables authentication spoofing.
1.121 markus 4508: * This should be called in the client only.
1.27 markus 4509: */
1.49 markus 4510: void
1.215 djm 4511: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.311 djm 4512: const char *proto, const char *data, int want_reply)
1.1 deraadt 4513: {
1.77 markus 4514: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 4515: u_int i, value;
1.25 markus 4516: char *new_data;
4517: int screen_number;
4518: const char *cp;
4519:
1.220 markus 4520: if (x11_saved_display == NULL)
4521: x11_saved_display = xstrdup(disp);
4522: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 4523: error("x11_request_forwarding_with_spoofing: different "
4524: "$DISPLAY already forwarded");
4525: return;
4526: }
4527:
1.266 djm 4528: cp = strchr(disp, ':');
1.25 markus 4529: if (cp)
4530: cp = strchr(cp, '.');
4531: if (cp)
1.245 deraadt 4532: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 4533: else
4534: screen_number = 0;
4535:
1.219 djm 4536: if (x11_saved_proto == NULL) {
4537: /* Save protocol name. */
4538: x11_saved_proto = xstrdup(proto);
1.353 natano 4539:
4540: /* Extract real authentication data. */
1.219 djm 4541: x11_saved_data = xmalloc(data_len);
4542: for (i = 0; i < data_len; i++) {
4543: if (sscanf(data + 2 * i, "%2x", &value) != 1)
4544: fatal("x11_request_forwarding: bad "
4545: "authentication data: %.100s", data);
4546: x11_saved_data[i] = value;
4547: }
4548: x11_saved_data_len = data_len;
1.353 natano 4549:
4550: /* Generate fake data of the same length. */
4551: x11_fake_data = xmalloc(data_len);
4552: arc4random_buf(x11_fake_data, data_len);
1.219 djm 4553: x11_fake_data_len = data_len;
1.25 markus 4554: }
4555:
4556: /* Convert the fake data into hex. */
1.219 djm 4557: new_data = tohex(x11_fake_data, data_len);
1.25 markus 4558:
4559: /* Send the request packet. */
1.51 markus 4560: if (compat20) {
1.311 djm 4561: channel_request_start(client_session_id, "x11-req", want_reply);
1.51 markus 4562: packet_put_char(0); /* XXX bool single connection */
4563: } else {
4564: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
4565: }
4566: packet_put_cstring(proto);
4567: packet_put_cstring(new_data);
1.25 markus 4568: packet_put_int(screen_number);
4569: packet_send();
4570: packet_write_wait();
1.321 djm 4571: free(new_data);
1.1 deraadt 4572: }
4573:
1.121 markus 4574:
4575: /* -- agent forwarding */
4576:
1.1 deraadt 4577: /* Sends a message to the server to request authentication fd forwarding. */
4578:
1.49 markus 4579: void
1.142 itojun 4580: auth_request_forwarding(void)
1.1 deraadt 4581: {
1.25 markus 4582: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
4583: packet_send();
4584: packet_write_wait();
1.1 deraadt 4585: }
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