Annotation of src/usr.bin/ssh/channels.c, Revision 1.72.2.6
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.44 markus 15: * SSH2 support added by Markus Friedl.
1.72.2.6! miod 16: * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
1.67 deraadt 17: * Copyright (c) 1999 Dug Song. All rights reserved.
18: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
19: *
20: * Redistribution and use in source and binary forms, with or without
21: * modification, are permitted provided that the following conditions
22: * are met:
23: * 1. Redistributions of source code must retain the above copyright
24: * notice, this list of conditions and the following disclaimer.
25: * 2. Redistributions in binary form must reproduce the above copyright
26: * notice, this list of conditions and the following disclaimer in the
27: * documentation and/or other materials provided with the distribution.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 39: */
1.1 deraadt 40:
41: #include "includes.h"
1.72.2.6! miod 42: RCSID("$OpenBSD: channels.c,v 1.134 2001/09/17 21:04:01 markus Exp $");
1.1 deraadt 43:
44: #include "ssh.h"
1.72.2.1 jason 45: #include "ssh1.h"
46: #include "ssh2.h"
1.1 deraadt 47: #include "packet.h"
48: #include "xmalloc.h"
49: #include "uidswap.h"
1.72.2.1 jason 50: #include "log.h"
51: #include "misc.h"
1.14 markus 52: #include "channels.h"
53: #include "compat.h"
1.72.2.1 jason 54: #include "canohost.h"
1.64 markus 55: #include "key.h"
56: #include "authfd.h"
1.44 markus 57:
1.1 deraadt 58:
1.72.2.6! miod 59: /* -- channel core */
1.12 markus 60:
1.27 markus 61: /*
62: * Pointer to an array containing all allocated channels. The array is
63: * dynamically extended as needed.
64: */
1.72.2.6! miod 65: static Channel **channels = NULL;
1.1 deraadt 66:
1.27 markus 67: /*
68: * Size of the channel array. All slots of the array must always be
1.72.2.6! miod 69: * initialized (at least the type field); unused slots set to NULL
1.27 markus 70: */
1.1 deraadt 71: static int channels_alloc = 0;
72:
1.27 markus 73: /*
74: * Maximum file descriptor value used in any of the channels. This is
1.72.2.6! miod 75: * updated in channel_new.
1.27 markus 76: */
1.72.2.1 jason 77: static int channel_max_fd = 0;
1.1 deraadt 78:
79:
1.72.2.6! miod 80: /* -- tcp forwarding */
1.1 deraadt 81:
1.27 markus 82: /*
83: * Data structure for storing which hosts are permitted for forward requests.
84: * The local sides of any remote forwards are stored in this array to prevent
85: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
86: * network (which might be behind a firewall).
87: */
1.25 markus 88: typedef struct {
1.41 markus 89: char *host_to_connect; /* Connect to 'host'. */
90: u_short port_to_connect; /* Connect to 'port'. */
91: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 92: } ForwardPermission;
93:
94: /* List of all permitted host/port pairs to connect. */
95: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
1.72.2.6! miod 96:
1.1 deraadt 97: /* Number of permitted host/port pairs in the array. */
98: static int num_permitted_opens = 0;
1.27 markus 99: /*
100: * If this is true, all opens are permitted. This is the case on the server
101: * on which we have to trust the client anyway, and the user could do
102: * anything after logging in anyway.
103: */
1.1 deraadt 104: static int all_opens_permitted = 0;
105:
106:
1.72.2.6! miod 107: /* -- X11 forwarding */
1.72.2.1 jason 108:
1.72.2.6! miod 109: /* Maximum number of fake X11 displays to try. */
! 110: #define MAX_DISPLAYS 1000
1.72.2.4 jason 111:
1.72.2.6! miod 112: /* Saved X11 authentication protocol name. */
! 113: static char *x11_saved_proto = NULL;
1.1 deraadt 114:
1.72.2.6! miod 115: /* Saved X11 authentication data. This is the real data. */
! 116: static char *x11_saved_data = NULL;
! 117: static u_int x11_saved_data_len = 0;
! 118:
! 119: /*
! 120: * Fake X11 authentication data. This is what the server will be sending us;
! 121: * we should replace any occurrences of this by the real data.
! 122: */
! 123: static char *x11_fake_data = NULL;
! 124: static u_int x11_fake_data_len;
! 125:
! 126:
! 127: /* -- agent forwarding */
! 128:
! 129: #define NUM_SOCKS 10
! 130:
! 131: /* Name and directory of socket for authentication agent forwarding. */
! 132: static char *auth_sock_name = NULL;
! 133: static char *auth_sock_dir = NULL;
! 134:
! 135: /* AF_UNSPEC or AF_INET or AF_INET6 */
! 136: extern int IPv4or6;
! 137:
! 138: /* helper */
! 139: static void port_open_helper(Channel *c, char *rtype);
1.1 deraadt 140:
1.72.2.6! miod 141: /* -- channel core */
1.41 markus 142:
143: Channel *
144: channel_lookup(int id)
145: {
146: Channel *c;
1.72.2.6! miod 147:
1.63 provos 148: if (id < 0 || id > channels_alloc) {
1.41 markus 149: log("channel_lookup: %d: bad id", id);
150: return NULL;
151: }
1.72.2.6! miod 152: c = channels[id];
! 153: if (c == NULL) {
1.41 markus 154: log("channel_lookup: %d: bad id: channel free", id);
155: return NULL;
156: }
157: return c;
1.55 markus 158: }
159:
1.27 markus 160: /*
1.55 markus 161: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 162: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 163: */
1.1 deraadt 164:
1.72.2.6! miod 165: static void
1.71 markus 166: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
167: int extusage, int nonblock)
1.1 deraadt 168: {
1.25 markus 169: /* Update the maximum file descriptor value. */
1.72.2.1 jason 170: channel_max_fd = MAX(channel_max_fd, rfd);
171: channel_max_fd = MAX(channel_max_fd, wfd);
172: channel_max_fd = MAX(channel_max_fd, efd);
173:
1.27 markus 174: /* XXX set close-on-exec -markus */
1.55 markus 175:
1.52 markus 176: c->rfd = rfd;
177: c->wfd = wfd;
178: c->sock = (rfd == wfd) ? rfd : -1;
179: c->efd = efd;
180: c->extended_usage = extusage;
1.71 markus 181:
1.72.2.1 jason 182: /* XXX ugly hack: nonblock is only set by the server */
183: if (nonblock && isatty(c->rfd)) {
1.72.2.3 jason 184: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.72.2.1 jason 185: c->isatty = 1;
186: if (!isatty(c->wfd)) {
1.72.2.3 jason 187: error("channel %d: wfd %d is not a tty?",
1.72.2.1 jason 188: c->self, c->wfd);
189: }
190: } else {
191: c->isatty = 0;
192: }
193:
1.71 markus 194: /* enable nonblocking mode */
195: if (nonblock) {
196: if (rfd != -1)
197: set_nonblock(rfd);
198: if (wfd != -1)
199: set_nonblock(wfd);
200: if (efd != -1)
201: set_nonblock(efd);
202: }
1.52 markus 203: }
204:
205: /*
206: * Allocate a new channel object and set its type and socket. This will cause
207: * remote_name to be freed.
208: */
209:
1.72.2.6! miod 210: Channel *
1.52 markus 211: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 212: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 213: {
214: int i, found;
215: Channel *c;
1.25 markus 216:
217: /* Do initial allocation if this is the first call. */
218: if (channels_alloc == 0) {
1.44 markus 219: chan_init();
1.25 markus 220: channels_alloc = 10;
1.72.2.6! miod 221: channels = xmalloc(channels_alloc * sizeof(Channel *));
1.25 markus 222: for (i = 0; i < channels_alloc; i++)
1.72.2.6! miod 223: channels[i] = NULL;
! 224: fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
1.25 markus 225: }
226: /* Try to find a free slot where to put the new channel. */
227: for (found = -1, i = 0; i < channels_alloc; i++)
1.72.2.6! miod 228: if (channels[i] == NULL) {
1.25 markus 229: /* Found a free slot. */
230: found = i;
231: break;
232: }
233: if (found == -1) {
1.27 markus 234: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 235: found = channels_alloc;
236: channels_alloc += 10;
1.70 markus 237: debug2("channel: expanding %d", channels_alloc);
1.72.2.6! miod 238: channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
1.25 markus 239: for (i = found; i < channels_alloc; i++)
1.72.2.6! miod 240: channels[i] = NULL;
1.25 markus 241: }
1.72.2.6! miod 242: /* Initialize and return new channel. */
! 243: c = channels[found] = xmalloc(sizeof(Channel));
1.25 markus 244: buffer_init(&c->input);
245: buffer_init(&c->output);
1.41 markus 246: buffer_init(&c->extended);
1.25 markus 247: chan_init_iostates(c);
1.71 markus 248: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 249: c->self = found;
250: c->type = type;
1.41 markus 251: c->ctype = ctype;
1.51 markus 252: c->local_window = window;
253: c->local_window_max = window;
254: c->local_consumed = 0;
255: c->local_maxpacket = maxpack;
1.25 markus 256: c->remote_id = -1;
257: c->remote_name = remote_name;
1.41 markus 258: c->remote_window = 0;
259: c->remote_maxpacket = 0;
260: c->cb_fn = NULL;
261: c->cb_arg = NULL;
262: c->cb_event = 0;
1.72.2.6! miod 263: c->force_drain = 0;
! 264: c->detach_user = NULL;
1.65 markus 265: c->input_filter = NULL;
1.25 markus 266: debug("channel %d: new [%s]", found, remote_name);
1.72.2.6! miod 267: return c;
! 268: }
! 269:
! 270: static int
! 271: channel_find_maxfd(void)
! 272: {
! 273: int i, max = 0;
! 274: Channel *c;
! 275:
! 276: for (i = 0; i < channels_alloc; i++) {
! 277: c = channels[i];
! 278: if (c != NULL) {
! 279: max = MAX(max, c->rfd);
! 280: max = MAX(max, c->wfd);
! 281: max = MAX(max, c->efd);
! 282: }
! 283: }
! 284: return max;
! 285: }
! 286:
! 287: int
! 288: channel_close_fd(int *fdp)
! 289: {
! 290: int ret = 0, fd = *fdp;
! 291:
! 292: if (fd != -1) {
! 293: ret = close(fd);
! 294: *fdp = -1;
! 295: if (fd == channel_max_fd)
! 296: channel_max_fd = channel_find_maxfd();
! 297: }
! 298: return ret;
! 299: }
! 300:
! 301: /* Close all channel fd/socket. */
! 302:
! 303: static void
! 304: channel_close_fds(Channel *c)
! 305: {
! 306: debug3("channel_close_fds: channel %d: r %d w %d e %d",
! 307: c->self, c->rfd, c->wfd, c->efd);
! 308:
! 309: channel_close_fd(&c->sock);
! 310: channel_close_fd(&c->rfd);
! 311: channel_close_fd(&c->wfd);
! 312: channel_close_fd(&c->efd);
! 313: }
! 314:
! 315: /* Free the channel and close its fd/socket. */
! 316:
! 317: void
! 318: channel_free(Channel *c)
! 319: {
! 320: char *s;
! 321: int i, n;
! 322:
! 323: for (n = 0, i = 0; i < channels_alloc; i++)
! 324: if (channels[i])
! 325: n++;
! 326: debug("channel_free: channel %d: %s, nchannels %d", c->self,
! 327: c->remote_name ? c->remote_name : "???", n);
! 328:
! 329: s = channel_open_message();
! 330: debug3("channel_free: status: %s", s);
! 331: xfree(s);
! 332:
! 333: if (c->detach_user != NULL) {
! 334: debug("channel_free: channel %d: detaching channel user", c->self);
! 335: c->detach_user(c->self, NULL);
! 336: }
! 337: if (c->sock != -1)
! 338: shutdown(c->sock, SHUT_RDWR);
! 339: channel_close_fds(c);
! 340: buffer_free(&c->input);
! 341: buffer_free(&c->output);
! 342: buffer_free(&c->extended);
! 343: if (c->remote_name) {
! 344: xfree(c->remote_name);
! 345: c->remote_name = NULL;
! 346: }
! 347: channels[c->self] = NULL;
! 348: xfree(c);
! 349: }
! 350:
! 351: void
! 352: channel_free_all(void)
! 353: {
! 354: int i;
! 355:
! 356: for (i = 0; i < channels_alloc; i++)
! 357: if (channels[i] != NULL)
! 358: channel_free(channels[i]);
! 359: }
! 360:
! 361: void
! 362: channel_detach_all(void)
! 363: {
! 364: int i;
! 365: Channel *c;
! 366:
! 367: for (i = 0; i < channels_alloc; i++) {
! 368: c = channels[i];
! 369: if (c != NULL && c->detach_user != NULL) {
! 370: debug("channel_detach_all: channel %d", c->self);
! 371: c->detach_user(c->self, NULL);
! 372: c->detach_user = NULL;
! 373: }
! 374: }
! 375: }
! 376:
! 377: /*
! 378: * Closes the sockets/fds of all channels. This is used to close extra file
! 379: * descriptors after a fork.
! 380: */
! 381:
! 382: void
! 383: channel_close_all()
! 384: {
! 385: int i;
! 386:
! 387: for (i = 0; i < channels_alloc; i++)
! 388: if (channels[i] != NULL)
! 389: channel_close_fds(channels[i]);
! 390: }
! 391:
! 392: /*
! 393: * Stop listening to channels.
! 394: */
! 395:
! 396: void
! 397: channel_stop_listening(void)
! 398: {
! 399: int i;
! 400: Channel *c;
! 401:
! 402: for (i = 0; i < channels_alloc; i++) {
! 403: c = channels[i];
! 404: if (c != NULL) {
! 405: switch (c->type) {
! 406: case SSH_CHANNEL_AUTH_SOCKET:
! 407: case SSH_CHANNEL_PORT_LISTENER:
! 408: case SSH_CHANNEL_RPORT_LISTENER:
! 409: case SSH_CHANNEL_X11_LISTENER:
! 410: channel_close_fd(&c->sock);
! 411: channel_free(c);
! 412: break;
! 413: }
! 414: }
! 415: }
! 416: }
! 417:
! 418: /*
! 419: * Returns true if no channel has too much buffered data, and false if one or
! 420: * more channel is overfull.
! 421: */
! 422:
! 423: int
! 424: channel_not_very_much_buffered_data()
! 425: {
! 426: u_int i;
! 427: Channel *c;
! 428:
! 429: for (i = 0; i < channels_alloc; i++) {
! 430: c = channels[i];
! 431: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
! 432: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
! 433: debug("channel %d: big input buffer %d",
! 434: c->self, buffer_len(&c->input));
! 435: return 0;
! 436: }
! 437: if (buffer_len(&c->output) > packet_get_maxsize()) {
! 438: debug("channel %d: big output buffer %d",
! 439: c->self, buffer_len(&c->output));
! 440: return 0;
! 441: }
! 442: }
! 443: }
! 444: return 1;
! 445: }
! 446:
! 447: /* Returns true if any channel is still open. */
! 448:
! 449: int
! 450: channel_still_open()
! 451: {
! 452: int i;
! 453: Channel *c;
! 454:
! 455: for (i = 0; i < channels_alloc; i++) {
! 456: c = channels[i];
! 457: if (c == NULL)
! 458: continue;
! 459: switch (c->type) {
! 460: case SSH_CHANNEL_X11_LISTENER:
! 461: case SSH_CHANNEL_PORT_LISTENER:
! 462: case SSH_CHANNEL_RPORT_LISTENER:
! 463: case SSH_CHANNEL_CLOSED:
! 464: case SSH_CHANNEL_AUTH_SOCKET:
! 465: case SSH_CHANNEL_DYNAMIC:
! 466: case SSH_CHANNEL_CONNECTING:
! 467: case SSH_CHANNEL_ZOMBIE:
! 468: continue;
! 469: case SSH_CHANNEL_LARVAL:
! 470: if (!compat20)
! 471: fatal("cannot happen: SSH_CHANNEL_LARVAL");
! 472: continue;
! 473: case SSH_CHANNEL_OPENING:
! 474: case SSH_CHANNEL_OPEN:
! 475: case SSH_CHANNEL_X11_OPEN:
! 476: return 1;
! 477: case SSH_CHANNEL_INPUT_DRAINING:
! 478: case SSH_CHANNEL_OUTPUT_DRAINING:
! 479: if (!compat13)
! 480: fatal("cannot happen: OUT_DRAIN");
! 481: return 1;
! 482: default:
! 483: fatal("channel_still_open: bad channel type %d", c->type);
! 484: /* NOTREACHED */
! 485: }
! 486: }
! 487: return 0;
1.1 deraadt 488: }
1.72.2.6! miod 489:
! 490: /* Returns the id of an open channel suitable for keepaliving */
! 491:
1.49 markus 492: int
1.72.2.6! miod 493: channel_find_open()
! 494: {
! 495: int i;
! 496: Channel *c;
! 497:
! 498: for (i = 0; i < channels_alloc; i++) {
! 499: c = channels[i];
! 500: if (c == NULL)
! 501: continue;
! 502: switch (c->type) {
! 503: case SSH_CHANNEL_CLOSED:
! 504: case SSH_CHANNEL_DYNAMIC:
! 505: case SSH_CHANNEL_X11_LISTENER:
! 506: case SSH_CHANNEL_PORT_LISTENER:
! 507: case SSH_CHANNEL_RPORT_LISTENER:
! 508: case SSH_CHANNEL_OPENING:
! 509: case SSH_CHANNEL_CONNECTING:
! 510: case SSH_CHANNEL_ZOMBIE:
! 511: continue;
! 512: case SSH_CHANNEL_LARVAL:
! 513: case SSH_CHANNEL_AUTH_SOCKET:
! 514: case SSH_CHANNEL_OPEN:
! 515: case SSH_CHANNEL_X11_OPEN:
! 516: return i;
! 517: case SSH_CHANNEL_INPUT_DRAINING:
! 518: case SSH_CHANNEL_OUTPUT_DRAINING:
! 519: if (!compat13)
! 520: fatal("cannot happen: OUT_DRAIN");
! 521: return i;
! 522: default:
! 523: fatal("channel_find_open: bad channel type %d", c->type);
! 524: /* NOTREACHED */
! 525: }
! 526: }
! 527: return -1;
! 528: }
! 529:
! 530:
! 531: /*
! 532: * Returns a message describing the currently open forwarded connections,
! 533: * suitable for sending to the client. The message contains crlf pairs for
! 534: * newlines.
! 535: */
! 536:
! 537: char *
! 538: channel_open_message()
1.41 markus 539: {
1.72.2.6! miod 540: Buffer buffer;
! 541: Channel *c;
! 542: char buf[1024], *cp;
! 543: int i;
! 544:
! 545: buffer_init(&buffer);
! 546: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
! 547: buffer_append(&buffer, buf, strlen(buf));
! 548: for (i = 0; i < channels_alloc; i++) {
! 549: c = channels[i];
! 550: if (c == NULL)
! 551: continue;
! 552: switch (c->type) {
! 553: case SSH_CHANNEL_X11_LISTENER:
! 554: case SSH_CHANNEL_PORT_LISTENER:
! 555: case SSH_CHANNEL_RPORT_LISTENER:
! 556: case SSH_CHANNEL_CLOSED:
! 557: case SSH_CHANNEL_AUTH_SOCKET:
! 558: case SSH_CHANNEL_ZOMBIE:
! 559: continue;
! 560: case SSH_CHANNEL_LARVAL:
! 561: case SSH_CHANNEL_OPENING:
! 562: case SSH_CHANNEL_CONNECTING:
! 563: case SSH_CHANNEL_DYNAMIC:
! 564: case SSH_CHANNEL_OPEN:
! 565: case SSH_CHANNEL_X11_OPEN:
! 566: case SSH_CHANNEL_INPUT_DRAINING:
! 567: case SSH_CHANNEL_OUTPUT_DRAINING:
! 568: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
! 569: c->self, c->remote_name,
! 570: c->type, c->remote_id,
! 571: c->istate, buffer_len(&c->input),
! 572: c->ostate, buffer_len(&c->output),
! 573: c->rfd, c->wfd);
! 574: buffer_append(&buffer, buf, strlen(buf));
! 575: continue;
! 576: default:
! 577: fatal("channel_open_message: bad channel type %d", c->type);
! 578: /* NOTREACHED */
! 579: }
! 580: }
! 581: buffer_append(&buffer, "\0", 1);
! 582: cp = xstrdup(buffer_ptr(&buffer));
! 583: buffer_free(&buffer);
! 584: return cp;
! 585: }
! 586:
! 587: void
! 588: channel_send_open(int id)
! 589: {
! 590: Channel *c = channel_lookup(id);
! 591: if (c == NULL) {
! 592: log("channel_send_open: %d: bad id", id);
! 593: return;
! 594: }
! 595: debug("send channel open %d", id);
! 596: packet_start(SSH2_MSG_CHANNEL_OPEN);
! 597: packet_put_cstring(c->ctype);
! 598: packet_put_int(c->self);
! 599: packet_put_int(c->local_window);
! 600: packet_put_int(c->local_maxpacket);
! 601: packet_send();
! 602: }
! 603:
! 604: void
! 605: channel_request(int id, char *service, int wantconfirm)
! 606: {
! 607: channel_request_start(id, service, wantconfirm);
! 608: packet_send();
! 609: debug("channel request %d: %s", id, service) ;
! 610: }
! 611: void
! 612: channel_request_start(int id, char *service, int wantconfirm)
! 613: {
! 614: Channel *c = channel_lookup(id);
! 615: if (c == NULL) {
! 616: log("channel_request: %d: bad id", id);
! 617: return;
! 618: }
! 619: packet_start(SSH2_MSG_CHANNEL_REQUEST);
! 620: packet_put_int(c->remote_id);
! 621: packet_put_cstring(service);
! 622: packet_put_char(wantconfirm);
! 623: }
! 624: void
! 625: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
! 626: {
! 627: Channel *c = channel_lookup(id);
! 628: if (c == NULL) {
! 629: log("channel_register_callback: %d: bad id", id);
! 630: return;
! 631: }
! 632: c->cb_event = mtype;
! 633: c->cb_fn = fn;
! 634: c->cb_arg = arg;
! 635: }
! 636: void
! 637: channel_register_cleanup(int id, channel_callback_fn *fn)
! 638: {
! 639: Channel *c = channel_lookup(id);
! 640: if (c == NULL) {
! 641: log("channel_register_cleanup: %d: bad id", id);
! 642: return;
! 643: }
! 644: c->detach_user = fn;
! 645: }
! 646: void
! 647: channel_cancel_cleanup(int id)
! 648: {
! 649: Channel *c = channel_lookup(id);
! 650: if (c == NULL) {
! 651: log("channel_cancel_cleanup: %d: bad id", id);
! 652: return;
! 653: }
! 654: c->detach_user = NULL;
1.41 markus 655: }
1.52 markus 656: void
1.72.2.6! miod 657: channel_register_filter(int id, channel_filter_fn *fn)
1.52 markus 658: {
1.72.2.6! miod 659: Channel *c = channel_lookup(id);
! 660: if (c == NULL) {
! 661: log("channel_register_filter: %d: bad id", id);
! 662: return;
1.52 markus 663: }
1.72.2.6! miod 664: c->input_filter = fn;
1.52 markus 665: }
666:
1.49 markus 667: void
1.72.2.6! miod 668: channel_set_fds(int id, int rfd, int wfd, int efd,
! 669: int extusage, int nonblock)
1.1 deraadt 670: {
1.41 markus 671: Channel *c = channel_lookup(id);
1.72.2.6! miod 672: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
! 673: fatal("channel_activate for non-larval channel %d.", id);
! 674: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
! 675: c->type = SSH_CHANNEL_OPEN;
! 676: /* XXX window size? */
! 677: c->local_window = c->local_window_max = c->local_maxpacket * 2;
! 678: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
! 679: packet_put_int(c->remote_id);
! 680: packet_put_int(c->local_window);
! 681: packet_send();
1.1 deraadt 682: }
683:
1.27 markus 684: /*
1.41 markus 685: * 'channel_pre*' are called just before select() to add any bits relevant to
686: * channels in the select bitmasks.
687: */
688: /*
689: * 'channel_post*': perform any appropriate operations for channels which
690: * have events pending.
1.27 markus 691: */
1.41 markus 692: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
693: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
694: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
695:
1.72.2.6! miod 696: static void
1.41 markus 697: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
698: {
699: FD_SET(c->sock, readset);
700: }
701:
1.72.2.6! miod 702: static void
1.72.2.1 jason 703: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
704: {
705: debug3("channel %d: waiting for connection", c->self);
706: FD_SET(c->sock, writeset);
707: }
708:
1.72.2.6! miod 709: static void
1.41 markus 710: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
711: {
712: if (buffer_len(&c->input) < packet_get_maxsize())
713: FD_SET(c->sock, readset);
714: if (buffer_len(&c->output) > 0)
715: FD_SET(c->sock, writeset);
716: }
1.1 deraadt 717:
1.72.2.6! miod 718: static void
1.41 markus 719: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
720: {
721: /* test whether sockets are 'alive' for read/write */
722: if (c->istate == CHAN_INPUT_OPEN)
723: if (buffer_len(&c->input) < packet_get_maxsize())
724: FD_SET(c->sock, readset);
725: if (c->ostate == CHAN_OUTPUT_OPEN ||
726: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
727: if (buffer_len(&c->output) > 0) {
728: FD_SET(c->sock, writeset);
729: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
730: chan_obuf_empty(c);
731: }
732: }
733: }
734:
1.72.2.6! miod 735: static void
1.44 markus 736: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
737: {
738: if (c->istate == CHAN_INPUT_OPEN &&
739: c->remote_window > 0 &&
740: buffer_len(&c->input) < c->remote_window)
741: FD_SET(c->rfd, readset);
742: if (c->ostate == CHAN_OUTPUT_OPEN ||
743: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
744: if (buffer_len(&c->output) > 0) {
745: FD_SET(c->wfd, writeset);
746: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
747: chan_obuf_empty(c);
748: }
749: }
750: /** XXX check close conditions, too */
751: if (c->efd != -1) {
752: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
753: buffer_len(&c->extended) > 0)
754: FD_SET(c->efd, writeset);
755: else if (c->extended_usage == CHAN_EXTENDED_READ &&
756: buffer_len(&c->extended) < c->remote_window)
757: FD_SET(c->efd, readset);
758: }
759: }
760:
1.72.2.6! miod 761: static void
1.41 markus 762: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
763: {
764: if (buffer_len(&c->input) == 0) {
765: packet_start(SSH_MSG_CHANNEL_CLOSE);
766: packet_put_int(c->remote_id);
767: packet_send();
768: c->type = SSH_CHANNEL_CLOSED;
1.72.2.4 jason 769: debug("channel %d: closing after input drain.", c->self);
1.41 markus 770: }
771: }
772:
1.72.2.6! miod 773: static void
1.41 markus 774: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
775: {
776: if (buffer_len(&c->output) == 0)
1.72.2.6! miod 777: chan_mark_dead(c);
1.49 markus 778: else
1.41 markus 779: FD_SET(c->sock, writeset);
780: }
781:
782: /*
783: * This is a special state for X11 authentication spoofing. An opened X11
784: * connection (when authentication spoofing is being done) remains in this
785: * state until the first packet has been completely read. The authentication
786: * data in that packet is then substituted by the real data if it matches the
787: * fake data, and the channel is put into normal mode.
1.51 markus 788: * XXX All this happens at the client side.
1.72.2.6! miod 789: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 790: */
1.72.2.6! miod 791: static int
! 792: x11_open_helper(Buffer *b)
1.1 deraadt 793: {
1.72.2.1 jason 794: u_char *ucp;
795: u_int proto_len, data_len;
1.25 markus 796:
1.41 markus 797: /* Check if the fixed size part of the packet is in buffer. */
1.72.2.6! miod 798: if (buffer_len(b) < 12)
1.41 markus 799: return 0;
800:
801: /* Parse the lengths of variable-length fields. */
1.72.2.6! miod 802: ucp = (u_char *) buffer_ptr(b);
1.41 markus 803: if (ucp[0] == 0x42) { /* Byte order MSB first. */
804: proto_len = 256 * ucp[6] + ucp[7];
805: data_len = 256 * ucp[8] + ucp[9];
806: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
807: proto_len = ucp[6] + 256 * ucp[7];
808: data_len = ucp[8] + 256 * ucp[9];
809: } else {
810: debug("Initial X11 packet contains bad byte order byte: 0x%x",
811: ucp[0]);
812: return -1;
813: }
814:
815: /* Check if the whole packet is in buffer. */
1.72.2.6! miod 816: if (buffer_len(b) <
1.41 markus 817: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
818: return 0;
819:
820: /* Check if authentication protocol matches. */
821: if (proto_len != strlen(x11_saved_proto) ||
822: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
823: debug("X11 connection uses different authentication protocol.");
824: return -1;
825: }
826: /* Check if authentication data matches our fake data. */
827: if (data_len != x11_fake_data_len ||
828: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
829: x11_fake_data, x11_fake_data_len) != 0) {
830: debug("X11 auth data does not match fake data.");
831: return -1;
832: }
833: /* Check fake data length */
834: if (x11_fake_data_len != x11_saved_data_len) {
835: error("X11 fake_data_len %d != saved_data_len %d",
836: x11_fake_data_len, x11_saved_data_len);
837: return -1;
838: }
839: /*
840: * Received authentication protocol and data match
841: * our fake data. Substitute the fake data with real
842: * data.
843: */
844: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
845: x11_saved_data, x11_saved_data_len);
846: return 1;
847: }
848:
1.72.2.6! miod 849: static void
1.41 markus 850: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
851: {
1.72.2.6! miod 852: int ret = x11_open_helper(&c->output);
1.41 markus 853: if (ret == 1) {
854: /* Start normal processing for the channel. */
855: c->type = SSH_CHANNEL_OPEN;
1.47 markus 856: channel_pre_open_13(c, readset, writeset);
1.41 markus 857: } else if (ret == -1) {
858: /*
859: * We have received an X11 connection that has bad
860: * authentication information.
861: */
1.72.2.3 jason 862: log("X11 connection rejected because of wrong authentication.");
1.41 markus 863: buffer_clear(&c->input);
864: buffer_clear(&c->output);
1.72.2.6! miod 865: channel_close_fd(&c->sock);
1.41 markus 866: c->sock = -1;
867: c->type = SSH_CHANNEL_CLOSED;
868: packet_start(SSH_MSG_CHANNEL_CLOSE);
869: packet_put_int(c->remote_id);
870: packet_send();
871: }
872: }
1.25 markus 873:
1.72.2.6! miod 874: static void
1.51 markus 875: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 876: {
1.72.2.6! miod 877: int ret = x11_open_helper(&c->output);
! 878:
! 879: /* c->force_drain = 1; */
! 880:
1.41 markus 881: if (ret == 1) {
882: c->type = SSH_CHANNEL_OPEN;
1.57 markus 883: if (compat20)
884: channel_pre_open_20(c, readset, writeset);
885: else
886: channel_pre_open_15(c, readset, writeset);
1.41 markus 887: } else if (ret == -1) {
888: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 889: chan_read_failed(c); /** force close? */
1.41 markus 890: chan_write_failed(c);
891: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
892: }
893: }
1.25 markus 894:
1.72.2.4 jason 895: /* try to decode a socks4 header */
1.72.2.6! miod 896: static int
1.72.2.4 jason 897: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
898: {
899: u_char *p, *host;
900: int len, have, i, found;
901: char username[256];
902: struct {
903: u_int8_t version;
904: u_int8_t command;
905: u_int16_t dest_port;
906: struct in_addr dest_addr;
907: } s4_req, s4_rsp;
908:
909: debug2("channel %d: decode socks4", c->self);
910:
911: have = buffer_len(&c->input);
912: len = sizeof(s4_req);
913: if (have < len)
914: return 0;
915: p = buffer_ptr(&c->input);
916: for (found = 0, i = len; i < have; i++) {
917: if (p[i] == '\0') {
918: found = 1;
919: break;
920: }
921: if (i > 1024) {
922: /* the peer is probably sending garbage */
923: debug("channel %d: decode socks4: too long",
924: c->self);
925: return -1;
926: }
927: }
928: if (!found)
929: return 0;
930: buffer_get(&c->input, (char *)&s4_req.version, 1);
931: buffer_get(&c->input, (char *)&s4_req.command, 1);
932: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
933: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
934: have = buffer_len(&c->input);
935: p = buffer_ptr(&c->input);
936: len = strlen(p);
937: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
938: if (len > have)
939: fatal("channel %d: decode socks4: len %d > have %d",
940: c->self, len, have);
941: strlcpy(username, p, sizeof(username));
942: buffer_consume(&c->input, len);
943: buffer_consume(&c->input, 1); /* trailing '\0' */
944:
945: host = inet_ntoa(s4_req.dest_addr);
946: strlcpy(c->path, host, sizeof(c->path));
947: c->host_port = ntohs(s4_req.dest_port);
948:
949: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
950: c->self, host, c->host_port, s4_req.command);
951:
952: if (s4_req.command != 1) {
953: debug("channel %d: cannot handle: socks4 cn %d",
954: c->self, s4_req.command);
955: return -1;
956: }
957: s4_rsp.version = 0; /* vn: 0 for reply */
958: s4_rsp.command = 90; /* cd: req granted */
959: s4_rsp.dest_port = 0; /* ignored */
960: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
961: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
962: return 1;
963: }
964:
965: /* dynamic port forwarding */
1.72.2.6! miod 966: static void
1.72.2.4 jason 967: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
968: {
969: u_char *p;
970: int have, ret;
971:
972: have = buffer_len(&c->input);
973:
974: debug2("channel %d: pre_dynamic: have %d", c->self, have);
975: /* buffer_dump(&c->input); */
976: /* check if the fixed size part of the packet is in buffer. */
977: if (have < 4) {
978: /* need more */
979: FD_SET(c->sock, readset);
980: return;
981: }
982: /* try to guess the protocol */
983: p = buffer_ptr(&c->input);
984: switch (p[0]) {
985: case 0x04:
986: ret = channel_decode_socks4(c, readset, writeset);
987: break;
988: default:
989: ret = -1;
990: break;
991: }
992: if (ret < 0) {
1.72.2.6! miod 993: chan_mark_dead(c);
1.72.2.4 jason 994: } else if (ret == 0) {
995: debug2("channel %d: pre_dynamic: need more", c->self);
996: /* need more */
997: FD_SET(c->sock, readset);
998: } else {
999: /* switch to the next state */
1000: c->type = SSH_CHANNEL_OPENING;
1001: port_open_helper(c, "direct-tcpip");
1002: }
1003: }
1004:
1.41 markus 1005: /* This is our fake X11 server socket. */
1.72.2.6! miod 1006: static void
1.41 markus 1007: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
1008: {
1.72.2.6! miod 1009: Channel *nc;
1.41 markus 1010: struct sockaddr addr;
1.72.2.6! miod 1011: int newsock;
1.41 markus 1012: socklen_t addrlen;
1.72.2.1 jason 1013: char buf[16384], *remote_ipaddr;
1.51 markus 1014: int remote_port;
1.25 markus 1015:
1.41 markus 1016: if (FD_ISSET(c->sock, readset)) {
1017: debug("X11 connection requested.");
1018: addrlen = sizeof(addr);
1019: newsock = accept(c->sock, &addr, &addrlen);
1020: if (newsock < 0) {
1021: error("accept: %.100s", strerror(errno));
1022: return;
1023: }
1.72.2.1 jason 1024: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1025: remote_port = get_peer_port(newsock);
1.41 markus 1026: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.72.2.1 jason 1027: remote_ipaddr, remote_port);
1.51 markus 1028:
1.72.2.6! miod 1029: nc = channel_new("accepted x11 socket",
1.51 markus 1030: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1031: c->local_window_max, c->local_maxpacket,
1.71 markus 1032: 0, xstrdup(buf), 1);
1.72.2.6! miod 1033: if (nc == NULL) {
! 1034: close(newsock);
! 1035: xfree(remote_ipaddr);
! 1036: return;
! 1037: }
1.51 markus 1038: if (compat20) {
1039: packet_start(SSH2_MSG_CHANNEL_OPEN);
1040: packet_put_cstring("x11");
1.72.2.6! miod 1041: packet_put_int(nc->self);
1.51 markus 1042: packet_put_int(c->local_window_max);
1043: packet_put_int(c->local_maxpacket);
1.72.2.1 jason 1044: /* originator ipaddr and port */
1045: packet_put_cstring(remote_ipaddr);
1.57 markus 1046: if (datafellows & SSH_BUG_X11FWD) {
1047: debug("ssh2 x11 bug compat mode");
1048: } else {
1049: packet_put_int(remote_port);
1050: }
1.51 markus 1051: packet_send();
1052: } else {
1053: packet_start(SSH_SMSG_X11_OPEN);
1.72.2.6! miod 1054: packet_put_int(nc->self);
! 1055: if (packet_get_protocol_flags() &
! 1056: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
! 1057: packet_put_cstring(buf);
1.51 markus 1058: packet_send();
1059: }
1.72.2.1 jason 1060: xfree(remote_ipaddr);
1.41 markus 1061: }
1062: }
1.25 markus 1063:
1.72.2.6! miod 1064: static void
1.72.2.4 jason 1065: port_open_helper(Channel *c, char *rtype)
1066: {
1067: int direct;
1068: char buf[1024];
1069: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1070: u_short remote_port = get_peer_port(c->sock);
1071:
1072: direct = (strcmp(rtype, "direct-tcpip") == 0);
1073:
1074: snprintf(buf, sizeof buf,
1075: "%s: listening port %d for %.100s port %d, "
1076: "connect from %.200s port %d",
1077: rtype, c->listening_port, c->path, c->host_port,
1078: remote_ipaddr, remote_port);
1079:
1080: xfree(c->remote_name);
1081: c->remote_name = xstrdup(buf);
1082:
1083: if (compat20) {
1084: packet_start(SSH2_MSG_CHANNEL_OPEN);
1085: packet_put_cstring(rtype);
1086: packet_put_int(c->self);
1087: packet_put_int(c->local_window_max);
1088: packet_put_int(c->local_maxpacket);
1089: if (direct) {
1090: /* target host, port */
1091: packet_put_cstring(c->path);
1092: packet_put_int(c->host_port);
1093: } else {
1094: /* listen address, port */
1095: packet_put_cstring(c->path);
1096: packet_put_int(c->listening_port);
1097: }
1098: /* originator host and port */
1099: packet_put_cstring(remote_ipaddr);
1100: packet_put_int(remote_port);
1101: packet_send();
1102: } else {
1103: packet_start(SSH_MSG_PORT_OPEN);
1104: packet_put_int(c->self);
1105: packet_put_cstring(c->path);
1106: packet_put_int(c->host_port);
1.72.2.6! miod 1107: if (packet_get_protocol_flags() &
! 1108: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.72.2.4 jason 1109: packet_put_cstring(c->remote_name);
1110: packet_send();
1111: }
1112: xfree(remote_ipaddr);
1113: }
1114:
1.41 markus 1115: /*
1116: * This socket is listening for connections to a forwarded TCP/IP port.
1117: */
1.72.2.6! miod 1118: static void
1.41 markus 1119: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
1120: {
1.72.2.4 jason 1121: Channel *nc;
1.41 markus 1122: struct sockaddr addr;
1.72.2.6! miod 1123: int newsock, nextstate;
1.41 markus 1124: socklen_t addrlen;
1.72.2.4 jason 1125: char *rtype;
1.72.2.1 jason 1126:
1.41 markus 1127: if (FD_ISSET(c->sock, readset)) {
1128: debug("Connection to port %d forwarding "
1129: "to %.100s port %d requested.",
1130: c->listening_port, c->path, c->host_port);
1.72.2.4 jason 1131:
1132: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
1133: "forwarded-tcpip" : "direct-tcpip";
1.72.2.6! miod 1134: nextstate = (c->host_port == 0 &&
! 1135: c->type != SSH_CHANNEL_RPORT_LISTENER) ?
! 1136: SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
1.72.2.4 jason 1137:
1.41 markus 1138: addrlen = sizeof(addr);
1139: newsock = accept(c->sock, &addr, &addrlen);
1140: if (newsock < 0) {
1141: error("accept: %.100s", strerror(errno));
1142: return;
1143: }
1.72.2.6! miod 1144: nc = channel_new(rtype,
1.72.2.4 jason 1145: nextstate, newsock, newsock, -1,
1.41 markus 1146: c->local_window_max, c->local_maxpacket,
1.72.2.4 jason 1147: 0, xstrdup(rtype), 1);
1148: if (nc == NULL) {
1.72.2.6! miod 1149: error("channel_post_port_listener: no new channel:");
! 1150: close(newsock);
1.72.2.4 jason 1151: return;
1.41 markus 1152: }
1.72.2.4 jason 1153: nc->listening_port = c->listening_port;
1154: nc->host_port = c->host_port;
1155: strlcpy(nc->path, c->path, sizeof(nc->path));
1156:
1157: if (nextstate != SSH_CHANNEL_DYNAMIC)
1158: port_open_helper(nc, rtype);
1.41 markus 1159: }
1160: }
1.25 markus 1161:
1.41 markus 1162: /*
1163: * This is the authentication agent socket listening for connections from
1164: * clients.
1165: */
1.72.2.6! miod 1166: static void
1.41 markus 1167: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
1168: {
1.72.2.6! miod 1169: Channel *nc;
! 1170: char *name;
! 1171: int newsock;
1.41 markus 1172: struct sockaddr addr;
1173: socklen_t addrlen;
1.25 markus 1174:
1.41 markus 1175: if (FD_ISSET(c->sock, readset)) {
1176: addrlen = sizeof(addr);
1177: newsock = accept(c->sock, &addr, &addrlen);
1178: if (newsock < 0) {
1179: error("accept from auth socket: %.100s", strerror(errno));
1180: return;
1181: }
1.72.2.6! miod 1182: name = xstrdup("accepted auth socket");
! 1183: nc = channel_new("accepted auth socket",
1.72.2.1 jason 1184: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1185: c->local_window_max, c->local_maxpacket,
1.72.2.6! miod 1186: 0, name, 1);
! 1187: if (nc == NULL) {
! 1188: error("channel_post_auth_listener: channel_new failed");
! 1189: xfree(name);
! 1190: close(newsock);
! 1191: }
1.72.2.1 jason 1192: if (compat20) {
1193: packet_start(SSH2_MSG_CHANNEL_OPEN);
1194: packet_put_cstring("auth-agent@openssh.com");
1.72.2.6! miod 1195: packet_put_int(nc->self);
1.72.2.1 jason 1196: packet_put_int(c->local_window_max);
1197: packet_put_int(c->local_maxpacket);
1198: } else {
1199: packet_start(SSH_SMSG_AGENT_OPEN);
1.72.2.6! miod 1200: packet_put_int(nc->self);
1.72.2.1 jason 1201: }
1.41 markus 1202: packet_send();
1203: }
1204: }
1.25 markus 1205:
1.72.2.6! miod 1206: static void
1.72.2.1 jason 1207: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
1208: {
1.72.2.6! miod 1209: int err = 0;
! 1210: socklen_t sz = sizeof(err);
! 1211:
1.72.2.1 jason 1212: if (FD_ISSET(c->sock, writeset)) {
1.72.2.6! miod 1213: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
! 1214: &sz) < 0) {
! 1215: err = errno;
! 1216: error("getsockopt SO_ERROR failed");
! 1217: }
! 1218: if (err == 0) {
! 1219: debug("channel %d: connected", c->self);
! 1220: c->type = SSH_CHANNEL_OPEN;
! 1221: if (compat20) {
! 1222: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
! 1223: packet_put_int(c->remote_id);
! 1224: packet_put_int(c->self);
! 1225: packet_put_int(c->local_window);
! 1226: packet_put_int(c->local_maxpacket);
! 1227: } else {
! 1228: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
! 1229: packet_put_int(c->remote_id);
! 1230: packet_put_int(c->self);
! 1231: }
1.72.2.1 jason 1232: } else {
1.72.2.6! miod 1233: debug("channel %d: not connected: %s",
! 1234: c->self, strerror(err));
! 1235: if (compat20) {
! 1236: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
! 1237: packet_put_int(c->remote_id);
! 1238: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
! 1239: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
! 1240: packet_put_cstring(strerror(err));
! 1241: packet_put_cstring("");
! 1242: }
1.72.2.1 jason 1243: } else {
1.72.2.6! miod 1244: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
! 1245: packet_put_int(c->remote_id);
1.72.2.1 jason 1246: }
1.72.2.6! miod 1247: chan_mark_dead(c);
1.72.2.1 jason 1248: }
1.72.2.6! miod 1249: packet_send();
1.72.2.1 jason 1250: }
1251: }
1252:
1.72.2.6! miod 1253: static int
1.41 markus 1254: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
1255: {
1256: char buf[16*1024];
1257: int len;
1.25 markus 1258:
1.41 markus 1259: if (c->rfd != -1 &&
1260: FD_ISSET(c->rfd, readset)) {
1261: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1262: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1263: return 1;
1.41 markus 1264: if (len <= 0) {
1.51 markus 1265: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 1266: c->self, c->rfd, len);
1.72.2.4 jason 1267: if (c->type != SSH_CHANNEL_OPEN) {
1268: debug("channel %d: not open", c->self);
1.72.2.6! miod 1269: chan_mark_dead(c);
1.72.2.4 jason 1270: return -1;
1271: } else if (compat13) {
1.41 markus 1272: buffer_consume(&c->output, buffer_len(&c->output));
1273: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.72.2.6! miod 1274: debug("channel %d: input draining.", c->self);
1.25 markus 1275: } else {
1.41 markus 1276: chan_read_failed(c);
1.25 markus 1277: }
1.41 markus 1278: return -1;
1279: }
1.65 markus 1280: if(c->input_filter != NULL) {
1.66 markus 1281: if (c->input_filter(c, buf, len) == -1) {
1.72.2.4 jason 1282: debug("channel %d: filter stops", c->self);
1.65 markus 1283: chan_read_failed(c);
1284: }
1285: } else {
1286: buffer_append(&c->input, buf, len);
1287: }
1.41 markus 1288: }
1289: return 1;
1290: }
1.72.2.6! miod 1291: static int
1.41 markus 1292: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
1293: {
1.72.2.3 jason 1294: struct termios tio;
1.72.2.6! miod 1295: u_char *data;
! 1296: u_int dlen;
1.41 markus 1297: int len;
1.25 markus 1298:
1.41 markus 1299: /* Send buffered output data to the socket. */
1300: if (c->wfd != -1 &&
1301: FD_ISSET(c->wfd, writeset) &&
1302: buffer_len(&c->output) > 0) {
1.72.2.6! miod 1303: data = buffer_ptr(&c->output);
! 1304: dlen = buffer_len(&c->output);
! 1305: len = write(c->wfd, data, dlen);
1.53 markus 1306: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1307: return 1;
1.41 markus 1308: if (len <= 0) {
1.72.2.4 jason 1309: if (c->type != SSH_CHANNEL_OPEN) {
1310: debug("channel %d: not open", c->self);
1.72.2.6! miod 1311: chan_mark_dead(c);
1.72.2.4 jason 1312: return -1;
1313: } else if (compat13) {
1.41 markus 1314: buffer_consume(&c->output, buffer_len(&c->output));
1.72.2.6! miod 1315: debug("channel %d: input draining.", c->self);
1.41 markus 1316: c->type = SSH_CHANNEL_INPUT_DRAINING;
1317: } else {
1318: chan_write_failed(c);
1319: }
1320: return -1;
1.25 markus 1321: }
1.72.2.6! miod 1322: if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
1.72.2.1 jason 1323: if (tcgetattr(c->wfd, &tio) == 0 &&
1324: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1325: /*
1326: * Simulate echo to reduce the impact of
1.72.2.3 jason 1327: * traffic analysis. We need to match the
1328: * size of a SSH2_MSG_CHANNEL_DATA message
1329: * (4 byte channel id + data)
1.72.2.1 jason 1330: */
1.72.2.3 jason 1331: packet_send_ignore(4 + len);
1.72.2.1 jason 1332: packet_send();
1333: }
1334: }
1.41 markus 1335: buffer_consume(&c->output, len);
1.44 markus 1336: if (compat20 && len > 0) {
1337: c->local_consumed += len;
1338: }
1339: }
1340: return 1;
1341: }
1.72.2.6! miod 1342: static int
1.44 markus 1343: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
1344: {
1345: char buf[16*1024];
1346: int len;
1347:
1.45 markus 1348: /** XXX handle drain efd, too */
1.44 markus 1349: if (c->efd != -1) {
1350: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1351: FD_ISSET(c->efd, writeset) &&
1352: buffer_len(&c->extended) > 0) {
1353: len = write(c->efd, buffer_ptr(&c->extended),
1354: buffer_len(&c->extended));
1.70 markus 1355: debug2("channel %d: written %d to efd %d",
1.44 markus 1356: c->self, len, c->efd);
1.72.2.3 jason 1357: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1358: return 1;
1359: if (len <= 0) {
1360: debug2("channel %d: closing write-efd %d",
1361: c->self, c->efd);
1.72.2.6! miod 1362: channel_close_fd(&c->efd);
1.72.2.3 jason 1363: } else {
1.44 markus 1364: buffer_consume(&c->extended, len);
1365: c->local_consumed += len;
1366: }
1367: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
1368: FD_ISSET(c->efd, readset)) {
1369: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1370: debug2("channel %d: read %d from efd %d",
1.44 markus 1371: c->self, len, c->efd);
1.72.2.3 jason 1372: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1373: return 1;
1374: if (len <= 0) {
1375: debug2("channel %d: closing read-efd %d",
1.45 markus 1376: c->self, c->efd);
1.72.2.6! miod 1377: channel_close_fd(&c->efd);
1.72.2.3 jason 1378: } else {
1.44 markus 1379: buffer_append(&c->extended, buf, len);
1.72.2.3 jason 1380: }
1.44 markus 1381: }
1382: }
1383: return 1;
1384: }
1.72.2.6! miod 1385: static int
1.72.2.3 jason 1386: channel_check_window(Channel *c)
1.44 markus 1387: {
1.72.2.4 jason 1388: if (c->type == SSH_CHANNEL_OPEN &&
1389: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 1390: c->local_window < c->local_window_max/2 &&
1391: c->local_consumed > 0) {
1392: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1393: packet_put_int(c->remote_id);
1394: packet_put_int(c->local_consumed);
1395: packet_send();
1.70 markus 1396: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1397: c->self, c->local_window,
1398: c->local_consumed);
1399: c->local_window += c->local_consumed;
1400: c->local_consumed = 0;
1.1 deraadt 1401: }
1.41 markus 1402: return 1;
1.1 deraadt 1403: }
1404:
1.72.2.6! miod 1405: static void
1.41 markus 1406: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1407: {
1408: channel_handle_rfd(c, readset, writeset);
1409: channel_handle_wfd(c, readset, writeset);
1410: }
1.1 deraadt 1411:
1.72.2.6! miod 1412: static void
1.44 markus 1413: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1414: {
1415: channel_handle_rfd(c, readset, writeset);
1416: channel_handle_wfd(c, readset, writeset);
1417: channel_handle_efd(c, readset, writeset);
1.72.2.3 jason 1418:
1419: channel_check_window(c);
1.44 markus 1420: }
1421:
1.72.2.6! miod 1422: static void
1.41 markus 1423: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1424: {
1.41 markus 1425: int len;
1426: /* Send buffered output data to the socket. */
1427: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1428: len = write(c->sock, buffer_ptr(&c->output),
1429: buffer_len(&c->output));
1430: if (len <= 0)
1431: buffer_consume(&c->output, buffer_len(&c->output));
1432: else
1433: buffer_consume(&c->output, len);
1434: }
1435: }
1.25 markus 1436:
1.72.2.6! miod 1437: static void
1.44 markus 1438: channel_handler_init_20(void)
1439: {
1440: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1441: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1442: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.72.2.1 jason 1443: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1444: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.72.2.1 jason 1445: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1446: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.72.2.4 jason 1447: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1448:
1449: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1450: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.72.2.1 jason 1451: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1452: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.72.2.1 jason 1453: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1454: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.72.2.4 jason 1455: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1456: }
1457:
1.72.2.6! miod 1458: static void
1.41 markus 1459: channel_handler_init_13(void)
1460: {
1461: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1462: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1463: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1464: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1465: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1466: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1467: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.72.2.1 jason 1468: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.72.2.4 jason 1469: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1470:
1.41 markus 1471: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1472: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1473: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1474: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1475: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.72.2.1 jason 1476: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.72.2.4 jason 1477: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1478: }
1.25 markus 1479:
1.72.2.6! miod 1480: static void
1.41 markus 1481: channel_handler_init_15(void)
1482: {
1483: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1484: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1485: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1486: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1487: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.72.2.1 jason 1488: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.72.2.4 jason 1489: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1490:
1.41 markus 1491: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1492: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1493: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1494: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.72.2.1 jason 1495: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.72.2.4 jason 1496: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1497: }
1.27 markus 1498:
1.72.2.6! miod 1499: static void
1.41 markus 1500: channel_handler_init(void)
1501: {
1502: int i;
1503: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1504: channel_pre[i] = NULL;
1505: channel_post[i] = NULL;
1506: }
1.44 markus 1507: if (compat20)
1508: channel_handler_init_20();
1509: else if (compat13)
1.41 markus 1510: channel_handler_init_13();
1511: else
1512: channel_handler_init_15();
1513: }
1.25 markus 1514:
1.72.2.6! miod 1515: static void
1.41 markus 1516: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1517: {
1518: static int did_init = 0;
1519: int i;
1520: Channel *c;
1.25 markus 1521:
1.41 markus 1522: if (!did_init) {
1523: channel_handler_init();
1524: did_init = 1;
1525: }
1526: for (i = 0; i < channels_alloc; i++) {
1.72.2.6! miod 1527: c = channels[i];
! 1528: if (c == NULL)
1.25 markus 1529: continue;
1.72.2.6! miod 1530: if (ftab[c->type] != NULL)
! 1531: (*ftab[c->type])(c, readset, writeset);
1.72.2.3 jason 1532: if (chan_is_dead(c)) {
1533: /*
1534: * we have to remove the fd's from the select mask
1535: * before the channels are free'd and the fd's are
1536: * closed
1537: */
1538: if (c->wfd != -1)
1539: FD_CLR(c->wfd, writeset);
1540: if (c->rfd != -1)
1541: FD_CLR(c->rfd, readset);
1542: if (c->efd != -1) {
1543: if (c->extended_usage == CHAN_EXTENDED_READ)
1544: FD_CLR(c->efd, readset);
1545: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1546: FD_CLR(c->efd, writeset);
1547: }
1.72.2.6! miod 1548: channel_free(c);
1.72.2.3 jason 1549: }
1.1 deraadt 1550: }
1551: }
1552:
1.72.2.6! miod 1553: /*
! 1554: * Allocate/update select bitmasks and add any bits relevant to channels in
! 1555: * select bitmasks.
! 1556: */
1.49 markus 1557: void
1.72.2.4 jason 1558: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.72.2.6! miod 1559: int *nallocp, int rekeying)
1.41 markus 1560: {
1.72.2.1 jason 1561: int n;
1562: u_int sz;
1563:
1564: n = MAX(*maxfdp, channel_max_fd);
1565:
1566: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.72.2.6! miod 1567: /* perhaps check sz < nalloc/2 and shrink? */
! 1568: if (*readsetp == NULL || sz > *nallocp) {
! 1569: *readsetp = xrealloc(*readsetp, sz);
! 1570: *writesetp = xrealloc(*writesetp, sz);
! 1571: *nallocp = sz;
1.72.2.1 jason 1572: }
1.72.2.6! miod 1573: *maxfdp = n;
1.72.2.1 jason 1574: memset(*readsetp, 0, sz);
1575: memset(*writesetp, 0, sz);
1576:
1.72.2.4 jason 1577: if (!rekeying)
1578: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1579: }
1580:
1.72.2.6! miod 1581: /*
! 1582: * After select, perform any appropriate operations for channels which have
! 1583: * events pending.
! 1584: */
1.49 markus 1585: void
1.41 markus 1586: channel_after_select(fd_set * readset, fd_set * writeset)
1587: {
1588: channel_handler(channel_post, readset, writeset);
1589: }
1590:
1.72.2.6! miod 1591:
1.72.2.1 jason 1592: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1593:
1.49 markus 1594: void
1.25 markus 1595: channel_output_poll()
1.1 deraadt 1596: {
1.25 markus 1597: int len, i;
1.41 markus 1598: Channel *c;
1.1 deraadt 1599:
1.25 markus 1600: for (i = 0; i < channels_alloc; i++) {
1.72.2.6! miod 1601: c = channels[i];
! 1602: if (c == NULL)
! 1603: continue;
1.37 markus 1604:
1.72.2.6! miod 1605: /*
! 1606: * We are only interested in channels that can have buffered
! 1607: * incoming data.
! 1608: */
1.37 markus 1609: if (compat13) {
1.41 markus 1610: if (c->type != SSH_CHANNEL_OPEN &&
1611: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1612: continue;
1613: } else {
1.41 markus 1614: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1615: continue;
1616: }
1.46 markus 1617: if (compat20 &&
1618: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.72.2.3 jason 1619: /* XXX is this true? */
1620: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1621: continue;
1622: }
1.25 markus 1623:
1624: /* Get the amount of buffered data for this channel. */
1.72.2.3 jason 1625: if ((c->istate == CHAN_INPUT_OPEN ||
1626: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1627: (len = buffer_len(&c->input)) > 0) {
1.72.2.6! miod 1628: /*
! 1629: * Send some data for the other side over the secure
! 1630: * connection.
! 1631: */
1.44 markus 1632: if (compat20) {
1633: if (len > c->remote_window)
1634: len = c->remote_window;
1635: if (len > c->remote_maxpacket)
1636: len = c->remote_maxpacket;
1.25 markus 1637: } else {
1.44 markus 1638: if (packet_is_interactive()) {
1639: if (len > 1024)
1640: len = 512;
1641: } else {
1642: /* Keep the packets at reasonable size. */
1643: if (len > packet_get_maxsize()/2)
1644: len = packet_get_maxsize()/2;
1645: }
1.25 markus 1646: }
1.41 markus 1647: if (len > 0) {
1.44 markus 1648: packet_start(compat20 ?
1649: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1650: packet_put_int(c->remote_id);
1651: packet_put_string(buffer_ptr(&c->input), len);
1652: packet_send();
1653: buffer_consume(&c->input, len);
1654: c->remote_window -= len;
1655: }
1656: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1657: if (compat13)
1658: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1659: /*
1660: * input-buffer is empty and read-socket shutdown:
1661: * tell peer, that we will not send more data: send IEOF
1662: */
1.41 markus 1663: chan_ibuf_empty(c);
1.25 markus 1664: }
1.44 markus 1665: /* Send extended data, i.e. stderr */
1666: if (compat20 &&
1667: c->remote_window > 0 &&
1668: (len = buffer_len(&c->extended)) > 0 &&
1669: c->extended_usage == CHAN_EXTENDED_READ) {
1.72.2.3 jason 1670: debug2("channel %d: rwin %d elen %d euse %d",
1671: c->self, c->remote_window, buffer_len(&c->extended),
1672: c->extended_usage);
1.44 markus 1673: if (len > c->remote_window)
1674: len = c->remote_window;
1675: if (len > c->remote_maxpacket)
1676: len = c->remote_maxpacket;
1677: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1678: packet_put_int(c->remote_id);
1679: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1680: packet_put_string(buffer_ptr(&c->extended), len);
1681: packet_send();
1682: buffer_consume(&c->extended, len);
1683: c->remote_window -= len;
1.72.2.3 jason 1684: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1685: }
1.25 markus 1686: }
1.1 deraadt 1687: }
1688:
1.72.2.6! miod 1689:
! 1690: /* -- protocol input */
1.1 deraadt 1691:
1.49 markus 1692: void
1.69 markus 1693: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1694: {
1.37 markus 1695: int id;
1.25 markus 1696: char *data;
1.72.2.1 jason 1697: u_int data_len;
1.41 markus 1698: Channel *c;
1.25 markus 1699:
1700: /* Get the channel number and verify it. */
1.37 markus 1701: id = packet_get_int();
1.41 markus 1702: c = channel_lookup(id);
1703: if (c == NULL)
1.37 markus 1704: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1705:
1706: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1707: if (c->type != SSH_CHANNEL_OPEN &&
1708: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1709: return;
1710:
1711: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1712: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1713: return;
1714:
1715: /* Get the data. */
1716: data = packet_get_string(&data_len);
1.48 markus 1717: packet_done();
1.41 markus 1718:
1.44 markus 1719: if (compat20){
1720: if (data_len > c->local_maxpacket) {
1721: log("channel %d: rcvd big packet %d, maxpack %d",
1722: c->self, data_len, c->local_maxpacket);
1723: }
1724: if (data_len > c->local_window) {
1725: log("channel %d: rcvd too much data %d, win %d",
1726: c->self, data_len, c->local_window);
1727: xfree(data);
1728: return;
1729: }
1730: c->local_window -= data_len;
1731: }else{
1732: packet_integrity_check(plen, 4 + 4 + data_len, type);
1733: }
1.41 markus 1734: buffer_append(&c->output, data, data_len);
1.25 markus 1735: xfree(data);
1.1 deraadt 1736: }
1.72.2.6! miod 1737:
1.49 markus 1738: void
1.69 markus 1739: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1740: {
1741: int id;
1742: int tcode;
1743: char *data;
1.72.2.1 jason 1744: u_int data_len;
1.44 markus 1745: Channel *c;
1746:
1747: /* Get the channel number and verify it. */
1748: id = packet_get_int();
1749: c = channel_lookup(id);
1750:
1751: if (c == NULL)
1752: packet_disconnect("Received extended_data for bad channel %d.", id);
1753: if (c->type != SSH_CHANNEL_OPEN) {
1754: log("channel %d: ext data for non open", id);
1755: return;
1756: }
1757: tcode = packet_get_int();
1758: if (c->efd == -1 ||
1759: c->extended_usage != CHAN_EXTENDED_WRITE ||
1760: tcode != SSH2_EXTENDED_DATA_STDERR) {
1761: log("channel %d: bad ext data", c->self);
1762: return;
1763: }
1764: data = packet_get_string(&data_len);
1.48 markus 1765: packet_done();
1.44 markus 1766: if (data_len > c->local_window) {
1767: log("channel %d: rcvd too much extended_data %d, win %d",
1768: c->self, data_len, c->local_window);
1769: xfree(data);
1770: return;
1771: }
1.70 markus 1772: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1773: c->local_window -= data_len;
1774: buffer_append(&c->extended, data, data_len);
1775: xfree(data);
1776: }
1777:
1.49 markus 1778: void
1.69 markus 1779: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1780: {
1781: int id;
1782: Channel *c;
1783:
1784: packet_integrity_check(plen, 4, type);
1785:
1786: id = packet_get_int();
1787: c = channel_lookup(id);
1788: if (c == NULL)
1789: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1790: chan_rcvd_ieof(c);
1.72.2.6! miod 1791:
! 1792: /* XXX force input close */
! 1793: if (c->force_drain) {
! 1794: debug("channel %d: FORCE input drain", c->self);
! 1795: c->istate = CHAN_INPUT_WAIT_DRAIN;
! 1796: }
! 1797:
1.41 markus 1798: }
1.1 deraadt 1799:
1.49 markus 1800: void
1.69 markus 1801: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1802: {
1.41 markus 1803: int id;
1804: Channel *c;
1.1 deraadt 1805:
1.41 markus 1806: packet_integrity_check(plen, 4, type);
1807:
1808: id = packet_get_int();
1809: c = channel_lookup(id);
1810: if (c == NULL)
1811: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1812:
1813: /*
1814: * Send a confirmation that we have closed the channel and no more
1815: * data is coming for it.
1816: */
1.25 markus 1817: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1818: packet_put_int(c->remote_id);
1.25 markus 1819: packet_send();
1820:
1.27 markus 1821: /*
1822: * If the channel is in closed state, we have sent a close request,
1823: * and the other side will eventually respond with a confirmation.
1824: * Thus, we cannot free the channel here, because then there would be
1825: * no-one to receive the confirmation. The channel gets freed when
1826: * the confirmation arrives.
1827: */
1.41 markus 1828: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1829: /*
1830: * Not a closed channel - mark it as draining, which will
1831: * cause it to be freed later.
1832: */
1.41 markus 1833: buffer_consume(&c->input, buffer_len(&c->input));
1834: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1835: }
1.1 deraadt 1836: }
1837:
1.41 markus 1838: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1839: void
1.69 markus 1840: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1841: {
1842: int id = packet_get_int();
1843: Channel *c = channel_lookup(id);
1844: packet_integrity_check(plen, 4, type);
1845: if (c == NULL)
1846: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1847: chan_rcvd_oclose(c);
1848: }
1.1 deraadt 1849:
1.49 markus 1850: void
1.69 markus 1851: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1852: {
1.41 markus 1853: int id = packet_get_int();
1854: Channel *c = channel_lookup(id);
1.1 deraadt 1855:
1.48 markus 1856: packet_done();
1.41 markus 1857: if (c == NULL)
1858: packet_disconnect("Received close confirmation for "
1859: "out-of-range channel %d.", id);
1860: if (c->type != SSH_CHANNEL_CLOSED)
1861: packet_disconnect("Received close confirmation for "
1862: "non-closed channel %d (type %d).", id, c->type);
1.72.2.6! miod 1863: channel_free(c);
1.1 deraadt 1864: }
1865:
1.49 markus 1866: void
1.69 markus 1867: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1868: {
1.41 markus 1869: int id, remote_id;
1870: Channel *c;
1.1 deraadt 1871:
1.44 markus 1872: if (!compat20)
1873: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1874:
1.41 markus 1875: id = packet_get_int();
1876: c = channel_lookup(id);
1.25 markus 1877:
1.41 markus 1878: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1879: packet_disconnect("Received open confirmation for "
1880: "non-opening channel %d.", id);
1881: remote_id = packet_get_int();
1.27 markus 1882: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1883: c->remote_id = remote_id;
1884: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1885:
1886: if (compat20) {
1887: c->remote_window = packet_get_int();
1888: c->remote_maxpacket = packet_get_int();
1.48 markus 1889: packet_done();
1.44 markus 1890: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1891: debug2("callback start");
1.44 markus 1892: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1893: debug2("callback done");
1.44 markus 1894: }
1895: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1896: c->remote_window, c->remote_maxpacket);
1897: }
1.1 deraadt 1898: }
1899:
1.72.2.6! miod 1900: static char *
! 1901: reason2txt(int reason)
! 1902: {
! 1903: switch(reason) {
! 1904: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
! 1905: return "administratively prohibited";
! 1906: case SSH2_OPEN_CONNECT_FAILED:
! 1907: return "connect failed";
! 1908: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
! 1909: return "unknown channel type";
! 1910: case SSH2_OPEN_RESOURCE_SHORTAGE:
! 1911: return "resource shortage";
! 1912: }
! 1913: return "unknown reason";
! 1914: }
! 1915:
1.49 markus 1916: void
1.69 markus 1917: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1918: {
1.72.2.1 jason 1919: int id, reason;
1920: char *msg = NULL, *lang = NULL;
1.41 markus 1921: Channel *c;
1922:
1.44 markus 1923: if (!compat20)
1924: packet_integrity_check(plen, 4, type);
1.41 markus 1925:
1926: id = packet_get_int();
1927: c = channel_lookup(id);
1.25 markus 1928:
1.41 markus 1929: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1930: packet_disconnect("Received open failure for "
1931: "non-opening channel %d.", id);
1.44 markus 1932: if (compat20) {
1.72.2.1 jason 1933: reason = packet_get_int();
1.72.2.6! miod 1934: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.72.2.1 jason 1935: msg = packet_get_string(NULL);
1936: lang = packet_get_string(NULL);
1937: }
1.48 markus 1938: packet_done();
1.72.2.6! miod 1939: log("channel %d: open failed: %s%s%s", id,
! 1940: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.72.2.1 jason 1941: if (msg != NULL)
1942: xfree(msg);
1943: if (lang != NULL)
1944: xfree(lang);
1.44 markus 1945: }
1.25 markus 1946: /* Free the channel. This will also close the socket. */
1.72.2.6! miod 1947: channel_free(c);
1.1 deraadt 1948: }
1949:
1.44 markus 1950: void
1.69 markus 1951: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1952: {
1953: int id;
1954: Channel *c;
1955:
1956: id = packet_get_int();
1957: c = channel_lookup(id);
1958:
1959: if (c == NULL ||
1960: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1961: packet_disconnect("Received request for "
1962: "non-open channel %d.", id);
1963: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1964: debug2("callback start");
1.44 markus 1965: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1966: debug2("callback done");
1.44 markus 1967: } else {
1968: char *service = packet_get_string(NULL);
1.72.2.3 jason 1969: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1970: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1971: xfree(service);
1972: }
1973: }
1974:
1.49 markus 1975: void
1.69 markus 1976: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1977: {
1978: Channel *c;
1979: int id, adjust;
1980:
1981: if (!compat20)
1982: return;
1983:
1984: /* Get the channel number and verify it. */
1985: id = packet_get_int();
1.72.2.6! miod 1986: c = channel_lookup(id);
1.72.2.4 jason 1987:
1.72.2.6! miod 1988: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
! 1989: log("Received window adjust for "
! 1990: "non-open channel %d.", id);
! 1991: return;
! 1992: }
! 1993: adjust = packet_get_int();
! 1994: packet_done();
! 1995: debug2("channel %d: rcvd adjust %d", id, adjust);
! 1996: c->remote_window += adjust;
! 1997: }
1.1 deraadt 1998:
1.72.2.6! miod 1999: void
! 2000: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2001: {
1.72.2.6! miod 2002: Channel *c = NULL;
! 2003: u_short host_port;
! 2004: char *host, *originator_string;
! 2005: int remote_id, sock = -1;
1.25 markus 2006:
1.72.2.6! miod 2007: remote_id = packet_get_int();
! 2008: host = packet_get_string(NULL);
! 2009: host_port = packet_get_int();
! 2010:
! 2011: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
! 2012: originator_string = packet_get_string(NULL);
! 2013: } else {
! 2014: originator_string = xstrdup("unknown (remote did not supply name)");
! 2015: }
! 2016: packet_done();
! 2017: sock = channel_connect_to(host, host_port);
! 2018: if (sock != -1) {
! 2019: c = channel_new("connected socket",
! 2020: SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
! 2021: originator_string, 1);
! 2022: if (c == NULL) {
! 2023: error("channel_input_port_open: channel_new failed");
! 2024: close(sock);
! 2025: } else {
! 2026: c->remote_id = remote_id;
1.25 markus 2027: }
2028: }
1.72.2.6! miod 2029: if (c == NULL) {
! 2030: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
! 2031: packet_put_int(remote_id);
! 2032: packet_send();
! 2033: }
! 2034: xfree(host);
1.1 deraadt 2035: }
2036:
1.72.2.6! miod 2037:
! 2038: /* -- tcp forwarding */
! 2039:
1.27 markus 2040: /*
2041: * Initiate forwarding of connections to local port "port" through the secure
2042: * channel to host:port from remote side.
2043: */
1.72.2.1 jason 2044: int
2045: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
2046: u_short port_to_connect, int gateway_ports)
2047: {
2048: return channel_request_forwarding(
2049: NULL, listen_port,
2050: host_to_connect, port_to_connect,
2051: gateway_ports, /*remote_fwd*/ 0);
2052: }
1.1 deraadt 2053:
1.72.2.1 jason 2054: /*
2055: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
2056: * (SSH_CHANNEL_RPORT_LISTENER).
2057: */
2058: int
2059: channel_request_forwarding(
2060: const char *listen_address, u_short listen_port,
2061: const char *host_to_connect, u_short port_to_connect,
2062: int gateway_ports, int remote_fwd)
1.25 markus 2063: {
1.72.2.6! miod 2064: Channel *c;
! 2065: int success, sock, on = 1, type;
1.35 markus 2066: struct addrinfo hints, *ai, *aitop;
2067: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.72.2.1 jason 2068: const char *host;
1.28 markus 2069: struct linger linger;
1.25 markus 2070:
1.72.2.1 jason 2071: success = 0;
2072:
2073: if (remote_fwd) {
2074: host = listen_address;
1.72.2.6! miod 2075: type = SSH_CHANNEL_RPORT_LISTENER;
1.72.2.1 jason 2076: } else {
2077: host = host_to_connect;
1.72.2.6! miod 2078: type = SSH_CHANNEL_PORT_LISTENER;
1.72.2.1 jason 2079: }
1.25 markus 2080:
1.72.2.6! miod 2081: if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
1.72.2.1 jason 2082: error("Forward host name too long.");
2083: return success;
2084: }
2085:
2086: /* XXX listen_address is currently ignored */
1.28 markus 2087: /*
1.35 markus 2088: * getaddrinfo returns a loopback address if the hostname is
2089: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2090: */
1.35 markus 2091: memset(&hints, 0, sizeof(hints));
2092: hints.ai_family = IPv4or6;
2093: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
2094: hints.ai_socktype = SOCK_STREAM;
1.72.2.1 jason 2095: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 2096: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
2097: packet_disconnect("getaddrinfo: fatal error");
2098:
2099: for (ai = aitop; ai; ai = ai->ai_next) {
2100: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2101: continue;
2102: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2103: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.72.2.1 jason 2104: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 2105: continue;
2106: }
2107: /* Create a port to listen for the host. */
2108: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2109: if (sock < 0) {
2110: /* this is no error since kernel may not support ipv6 */
2111: verbose("socket: %.100s", strerror(errno));
2112: continue;
2113: }
2114: /*
2115: * Set socket options. We would like the socket to disappear
2116: * as soon as it has been closed for whatever reason.
2117: */
2118: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
2119: linger.l_onoff = 1;
2120: linger.l_linger = 5;
2121: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
2122: debug("Local forwarding listening on %s port %s.", ntop, strport);
2123:
2124: /* Bind the socket to the address. */
2125: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2126: /* address can be in use ipv6 address is already bound */
2127: verbose("bind: %.100s", strerror(errno));
2128: close(sock);
2129: continue;
2130: }
2131: /* Start listening for connections on the socket. */
2132: if (listen(sock, 5) < 0) {
2133: error("listen: %.100s", strerror(errno));
2134: close(sock);
2135: continue;
2136: }
2137: /* Allocate a channel number for the socket. */
1.72.2.6! miod 2138: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2139: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 2140: 0, xstrdup("port listener"), 1);
1.72.2.6! miod 2141: if (c == NULL) {
! 2142: error("channel_request_forwarding: channel_new failed");
! 2143: close(sock);
! 2144: continue;
! 2145: }
! 2146: strlcpy(c->path, host, sizeof(c->path));
! 2147: c->host_port = port_to_connect;
! 2148: c->listening_port = listen_port;
1.35 markus 2149: success = 1;
2150: }
2151: if (success == 0)
1.72.2.1 jason 2152: error("channel_request_forwarding: cannot listen to port: %d",
2153: listen_port);
1.35 markus 2154: freeaddrinfo(aitop);
1.72.2.1 jason 2155: return success;
1.25 markus 2156: }
1.1 deraadt 2157:
1.27 markus 2158: /*
2159: * Initiate forwarding of connections to port "port" on remote host through
2160: * the secure channel to host:port from local side.
2161: */
1.1 deraadt 2162:
1.49 markus 2163: void
1.72.2.1 jason 2164: channel_request_remote_forwarding(u_short listen_port,
2165: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2166: {
1.72.2.1 jason 2167: int payload_len, type, success = 0;
2168:
1.25 markus 2169: /* Record locally that connection to this host/port is permitted. */
2170: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2171: fatal("channel_request_remote_forwarding: too many forwards");
2172:
2173: /* Send the forward request to the remote side. */
1.44 markus 2174: if (compat20) {
2175: const char *address_to_bind = "0.0.0.0";
2176: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2177: packet_put_cstring("tcpip-forward");
2178: packet_put_char(0); /* boolean: want reply */
2179: packet_put_cstring(address_to_bind);
2180: packet_put_int(listen_port);
1.72.2.1 jason 2181: packet_send();
2182: packet_write_wait();
2183: /* Assume that server accepts the request */
2184: success = 1;
1.44 markus 2185: } else {
2186: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2187: packet_put_int(listen_port);
2188: packet_put_cstring(host_to_connect);
1.44 markus 2189: packet_put_int(port_to_connect);
2190: packet_send();
2191: packet_write_wait();
1.72.2.1 jason 2192:
2193: /* Wait for response from the remote side. */
2194: type = packet_read(&payload_len);
2195: switch (type) {
2196: case SSH_SMSG_SUCCESS:
2197: success = 1;
2198: break;
2199: case SSH_SMSG_FAILURE:
2200: log("Warning: Server denied remote port forwarding.");
2201: break;
2202: default:
2203: /* Unknown packet */
2204: packet_disconnect("Protocol error for port forward request:"
2205: "received packet type %d.", type);
2206: }
2207: }
2208: if (success) {
2209: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2210: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2211: permitted_opens[num_permitted_opens].listen_port = listen_port;
2212: num_permitted_opens++;
1.44 markus 2213: }
1.1 deraadt 2214: }
2215:
1.27 markus 2216: /*
2217: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2218: * listening for the port, and sends back a success reply (or disconnect
2219: * message if there was an error). This never returns if there was an error.
2220: */
1.1 deraadt 2221:
1.49 markus 2222: void
1.56 markus 2223: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 2224: {
1.31 markus 2225: u_short port, host_port;
1.25 markus 2226: char *hostname;
1.1 deraadt 2227:
1.25 markus 2228: /* Get arguments from the packet. */
2229: port = packet_get_int();
2230: hostname = packet_get_string(NULL);
2231: host_port = packet_get_int();
2232:
1.27 markus 2233: /*
2234: * Check that an unprivileged user is not trying to forward a
2235: * privileged port.
2236: */
1.25 markus 2237: if (port < IPPORT_RESERVED && !is_root)
2238: packet_disconnect("Requested forwarding of port %d but user is not root.",
2239: port);
1.72.2.1 jason 2240: /* Initiate forwarding */
1.56 markus 2241: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 2242:
2243: /* Free the argument string. */
2244: xfree(hostname);
1.1 deraadt 2245: }
2246:
1.72.2.3 jason 2247: /*
2248: * Permits opening to any host/port if permitted_opens[] is empty. This is
2249: * usually called by the server, because the user could connect to any port
2250: * anyway, and the server has no way to know but to trust the client anyway.
2251: */
2252: void
2253: channel_permit_all_opens()
2254: {
2255: if (num_permitted_opens == 0)
2256: all_opens_permitted = 1;
2257: }
2258:
1.72.2.4 jason 2259: void
1.72.2.3 jason 2260: channel_add_permitted_opens(char *host, int port)
2261: {
2262: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2263: fatal("channel_request_remote_forwarding: too many forwards");
2264: debug("allow port forwarding to host %s port %d", host, port);
2265:
2266: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2267: permitted_opens[num_permitted_opens].port_to_connect = port;
2268: num_permitted_opens++;
2269:
2270: all_opens_permitted = 0;
2271: }
2272:
1.72.2.4 jason 2273: void
1.72.2.3 jason 2274: channel_clear_permitted_opens(void)
2275: {
2276: int i;
2277:
2278: for (i = 0; i < num_permitted_opens; i++)
2279: xfree(permitted_opens[i].host_to_connect);
2280: num_permitted_opens = 0;
2281:
2282: }
2283:
2284:
2285: /* return socket to remote host, port */
1.72.2.6! miod 2286: static int
1.72.2.3 jason 2287: connect_to(const char *host, u_short port)
1.41 markus 2288: {
2289: struct addrinfo hints, *ai, *aitop;
2290: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2291: int gaierr;
2292: int sock = -1;
2293:
2294: memset(&hints, 0, sizeof(hints));
2295: hints.ai_family = IPv4or6;
2296: hints.ai_socktype = SOCK_STREAM;
1.72.2.3 jason 2297: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2298: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.72.2.3 jason 2299: error("connect_to %.100s: unknown host (%s)", host,
2300: gai_strerror(gaierr));
1.41 markus 2301: return -1;
2302: }
2303: for (ai = aitop; ai; ai = ai->ai_next) {
2304: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2305: continue;
2306: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2307: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.72.2.3 jason 2308: error("connect_to: getnameinfo failed");
1.41 markus 2309: continue;
2310: }
2311: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2312: if (sock < 0) {
2313: error("socket: %.100s", strerror(errno));
2314: continue;
2315: }
1.72.2.1 jason 2316: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
2317: fatal("connect_to: F_SETFL: %s", strerror(errno));
2318: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2319: errno != EINPROGRESS) {
1.72.2.3 jason 2320: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2321: strerror(errno));
2322: close(sock);
1.72.2.1 jason 2323: continue; /* fail -- try next */
1.41 markus 2324: }
2325: break; /* success */
2326:
2327: }
2328: freeaddrinfo(aitop);
2329: if (!ai) {
1.72.2.3 jason 2330: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2331: return -1;
2332: }
2333: /* success */
2334: return sock;
2335: }
1.72.2.3 jason 2336:
1.72.2.1 jason 2337: int
1.72.2.6! miod 2338: channel_connect_by_listen_address(u_short listen_port)
1.72.2.1 jason 2339: {
2340: int i;
1.72.2.3 jason 2341:
1.72.2.1 jason 2342: for (i = 0; i < num_permitted_opens; i++)
2343: if (permitted_opens[i].listen_port == listen_port)
1.72.2.3 jason 2344: return connect_to(
1.72.2.1 jason 2345: permitted_opens[i].host_to_connect,
2346: permitted_opens[i].port_to_connect);
2347: error("WARNING: Server requests forwarding for unknown listen_port %d",
2348: listen_port);
2349: return -1;
2350: }
2351:
1.72.2.3 jason 2352: /* Check if connecting to that port is permitted and connect. */
2353: int
2354: channel_connect_to(const char *host, u_short port)
2355: {
2356: int i, permit;
2357:
2358: permit = all_opens_permitted;
2359: if (!permit) {
2360: for (i = 0; i < num_permitted_opens; i++)
2361: if (permitted_opens[i].port_to_connect == port &&
2362: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2363: permit = 1;
2364:
2365: }
2366: if (!permit) {
2367: log("Received request to connect to host %.100s port %d, "
2368: "but the request was denied.", host, port);
2369: return -1;
2370: }
2371: return connect_to(host, port);
2372: }
2373:
1.72.2.6! miod 2374: /* -- X11 forwarding */
1.1 deraadt 2375:
1.27 markus 2376: /*
2377: * Creates an internet domain socket for listening for X11 connections.
2378: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2379: * occurs.
2380: */
1.25 markus 2381: char *
1.33 markus 2382: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2383: {
1.31 markus 2384: int display_number, sock;
2385: u_short port;
1.35 markus 2386: struct addrinfo hints, *ai, *aitop;
2387: char strport[NI_MAXSERV];
2388: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2389: char display[512];
1.25 markus 2390: char hostname[MAXHOSTNAMELEN];
2391:
1.33 markus 2392: for (display_number = x11_display_offset;
1.25 markus 2393: display_number < MAX_DISPLAYS;
2394: display_number++) {
2395: port = 6000 + display_number;
1.35 markus 2396: memset(&hints, 0, sizeof(hints));
2397: hints.ai_family = IPv4or6;
1.36 markus 2398: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2399: hints.ai_socktype = SOCK_STREAM;
2400: snprintf(strport, sizeof strport, "%d", port);
2401: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2402: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2403: return NULL;
2404: }
1.35 markus 2405: for (ai = aitop; ai; ai = ai->ai_next) {
2406: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2407: continue;
2408: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2409: if (sock < 0) {
2410: error("socket: %.100s", strerror(errno));
2411: return NULL;
2412: }
2413: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2414: debug("bind port %d: %.100s", port, strerror(errno));
2415: shutdown(sock, SHUT_RDWR);
2416: close(sock);
2417: for (n = 0; n < num_socks; n++) {
2418: shutdown(socks[n], SHUT_RDWR);
2419: close(socks[n]);
2420: }
2421: num_socks = 0;
2422: break;
2423: }
2424: socks[num_socks++] = sock;
2425: if (num_socks == NUM_SOCKS)
2426: break;
1.25 markus 2427: }
1.72.2.1 jason 2428: freeaddrinfo(aitop);
1.35 markus 2429: if (num_socks > 0)
2430: break;
1.25 markus 2431: }
2432: if (display_number >= MAX_DISPLAYS) {
2433: error("Failed to allocate internet-domain X11 display socket.");
2434: return NULL;
2435: }
2436: /* Start listening for connections on the socket. */
1.35 markus 2437: for (n = 0; n < num_socks; n++) {
2438: sock = socks[n];
2439: if (listen(sock, 5) < 0) {
2440: error("listen: %.100s", strerror(errno));
2441: shutdown(sock, SHUT_RDWR);
2442: close(sock);
2443: return NULL;
2444: }
1.25 markus 2445: }
1.35 markus 2446:
1.25 markus 2447: /* Set up a suitable value for the DISPLAY variable. */
2448: if (gethostname(hostname, sizeof(hostname)) < 0)
2449: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2450: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2451: display_number, screen_number);
2452:
1.35 markus 2453: /* Allocate a channel for each socket. */
2454: for (n = 0; n < num_socks; n++) {
2455: sock = socks[n];
1.51 markus 2456: (void) channel_new("x11 listener",
2457: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2458: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2459: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2460: }
1.1 deraadt 2461:
1.25 markus 2462: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2463: return xstrdup(display);
1.1 deraadt 2464: }
2465:
2466: #ifndef X_UNIX_PATH
2467: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2468: #endif
2469:
1.72.2.6! miod 2470: static int
1.72.2.1 jason 2471: connect_local_xsocket(u_int dnr)
1.1 deraadt 2472: {
1.25 markus 2473: static const char *const x_sockets[] = {
2474: X_UNIX_PATH "%u",
2475: "/var/X/.X11-unix/X" "%u",
2476: "/usr/spool/sockets/X11/" "%u",
2477: NULL
2478: };
2479: int sock;
2480: struct sockaddr_un addr;
2481: const char *const * path;
2482:
2483: for (path = x_sockets; *path; ++path) {
2484: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2485: if (sock < 0)
2486: error("socket: %.100s", strerror(errno));
2487: memset(&addr, 0, sizeof(addr));
2488: addr.sun_family = AF_UNIX;
2489: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2490: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2491: return sock;
2492: close(sock);
2493: }
2494: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2495: return -1;
1.1 deraadt 2496: }
2497:
1.51 markus 2498: int
2499: x11_connect_display(void)
1.1 deraadt 2500: {
1.51 markus 2501: int display_number, sock = 0;
1.25 markus 2502: const char *display;
1.51 markus 2503: char buf[1024], *cp;
1.35 markus 2504: struct addrinfo hints, *ai, *aitop;
2505: char strport[NI_MAXSERV];
2506: int gaierr;
1.25 markus 2507:
2508: /* Try to open a socket for the local X server. */
2509: display = getenv("DISPLAY");
2510: if (!display) {
2511: error("DISPLAY not set.");
1.51 markus 2512: return -1;
1.25 markus 2513: }
1.27 markus 2514: /*
2515: * Now we decode the value of the DISPLAY variable and make a
2516: * connection to the real X server.
2517: */
2518:
2519: /*
2520: * Check if it is a unix domain socket. Unix domain displays are in
2521: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2522: */
1.25 markus 2523: if (strncmp(display, "unix:", 5) == 0 ||
2524: display[0] == ':') {
2525: /* Connect to the unix domain socket. */
2526: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2527: error("Could not parse display number from DISPLAY: %.100s",
2528: display);
1.51 markus 2529: return -1;
1.25 markus 2530: }
2531: /* Create a socket. */
2532: sock = connect_local_xsocket(display_number);
2533: if (sock < 0)
1.51 markus 2534: return -1;
1.25 markus 2535:
2536: /* OK, we now have a connection to the display. */
1.51 markus 2537: return sock;
1.25 markus 2538: }
1.27 markus 2539: /*
2540: * Connect to an inet socket. The DISPLAY value is supposedly
2541: * hostname:d[.s], where hostname may also be numeric IP address.
2542: */
1.25 markus 2543: strncpy(buf, display, sizeof(buf));
2544: buf[sizeof(buf) - 1] = 0;
2545: cp = strchr(buf, ':');
2546: if (!cp) {
2547: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2548: return -1;
1.25 markus 2549: }
2550: *cp = 0;
1.27 markus 2551: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2552: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2553: error("Could not parse display number from DISPLAY: %.100s",
2554: display);
1.51 markus 2555: return -1;
1.25 markus 2556: }
1.35 markus 2557:
2558: /* Look up the host address */
2559: memset(&hints, 0, sizeof(hints));
2560: hints.ai_family = IPv4or6;
2561: hints.ai_socktype = SOCK_STREAM;
2562: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2563: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2564: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2565: return -1;
1.25 markus 2566: }
1.35 markus 2567: for (ai = aitop; ai; ai = ai->ai_next) {
2568: /* Create a socket. */
2569: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2570: if (sock < 0) {
2571: debug("socket: %.100s", strerror(errno));
1.41 markus 2572: continue;
2573: }
2574: /* Connect it to the display. */
2575: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2576: debug("connect %.100s port %d: %.100s", buf,
2577: 6000 + display_number, strerror(errno));
2578: close(sock);
2579: continue;
2580: }
2581: /* Success */
2582: break;
1.35 markus 2583: }
2584: freeaddrinfo(aitop);
2585: if (!ai) {
1.49 markus 2586: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2587: strerror(errno));
1.51 markus 2588: return -1;
1.25 markus 2589: }
1.51 markus 2590: return sock;
2591: }
2592:
2593: /*
2594: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2595: * the remote channel number. We should do whatever we want, and respond
2596: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2597: */
2598:
2599: void
1.69 markus 2600: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2601: {
1.72.2.6! miod 2602: Channel *c = NULL;
! 2603: int remote_id, sock = 0;
1.51 markus 2604: char *remote_host;
1.25 markus 2605:
1.72.2.6! miod 2606: debug("Received X11 open request.");
! 2607:
! 2608: remote_id = packet_get_int();
1.51 markus 2609:
1.72.2.6! miod 2610: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
! 2611: remote_host = packet_get_string(NULL);
1.51 markus 2612: } else {
2613: remote_host = xstrdup("unknown (remote did not supply name)");
2614: }
1.72.2.6! miod 2615: packet_done();
1.25 markus 2616:
1.51 markus 2617: /* Obtain a connection to the real X display. */
2618: sock = x11_connect_display();
1.72.2.6! miod 2619: if (sock != -1) {
! 2620: /* Allocate a channel for this connection. */
! 2621: c = channel_new("connected x11 socket",
! 2622: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
! 2623: remote_host, 1);
! 2624: if (c == NULL) {
! 2625: error("x11_input_open: channel_new failed");
! 2626: close(sock);
! 2627: } else {
! 2628: c->remote_id = remote_id;
! 2629: c->force_drain = 1;
! 2630: }
! 2631: }
! 2632: if (c == NULL) {
1.51 markus 2633: /* Send refusal to the remote host. */
2634: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.72.2.6! miod 2635: packet_put_int(remote_id);
1.51 markus 2636: } else {
2637: /* Send a confirmation to the remote host. */
2638: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.72.2.6! miod 2639: packet_put_int(remote_id);
! 2640: packet_put_int(c->self);
1.51 markus 2641: }
1.72.2.6! miod 2642: packet_send();
1.72 markus 2643: }
2644:
2645: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2646: void
2647: deny_input_open(int type, int plen, void *ctxt)
2648: {
2649: int rchan = packet_get_int();
2650: switch(type){
2651: case SSH_SMSG_AGENT_OPEN:
2652: error("Warning: ssh server tried agent forwarding.");
2653: break;
2654: case SSH_SMSG_X11_OPEN:
2655: error("Warning: ssh server tried X11 forwarding.");
2656: break;
2657: default:
2658: error("deny_input_open: type %d plen %d", type, plen);
2659: break;
2660: }
2661: error("Warning: this is probably a break in attempt by a malicious server.");
2662: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2663: packet_put_int(rchan);
2664: packet_send();
1.1 deraadt 2665: }
2666:
1.27 markus 2667: /*
2668: * Requests forwarding of X11 connections, generates fake authentication
2669: * data, and enables authentication spoofing.
1.72.2.6! miod 2670: * This should be called in the client only.
1.27 markus 2671: */
1.49 markus 2672: void
1.51 markus 2673: x11_request_forwarding_with_spoofing(int client_session_id,
2674: const char *proto, const char *data)
1.1 deraadt 2675: {
1.72.2.1 jason 2676: u_int data_len = (u_int) strlen(data) / 2;
2677: u_int i, value, len;
1.25 markus 2678: char *new_data;
2679: int screen_number;
2680: const char *cp;
2681: u_int32_t rand = 0;
2682:
2683: cp = getenv("DISPLAY");
2684: if (cp)
2685: cp = strchr(cp, ':');
2686: if (cp)
2687: cp = strchr(cp, '.');
2688: if (cp)
2689: screen_number = atoi(cp + 1);
2690: else
2691: screen_number = 0;
2692:
2693: /* Save protocol name. */
2694: x11_saved_proto = xstrdup(proto);
2695:
1.27 markus 2696: /*
2697: * Extract real authentication data and generate fake data of the
2698: * same length.
2699: */
1.25 markus 2700: x11_saved_data = xmalloc(data_len);
2701: x11_fake_data = xmalloc(data_len);
2702: for (i = 0; i < data_len; i++) {
2703: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2704: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2705: if (i % 4 == 0)
2706: rand = arc4random();
2707: x11_saved_data[i] = value;
2708: x11_fake_data[i] = rand & 0xff;
2709: rand >>= 8;
2710: }
2711: x11_saved_data_len = data_len;
2712: x11_fake_data_len = data_len;
2713:
2714: /* Convert the fake data into hex. */
1.72.2.1 jason 2715: len = 2 * data_len + 1;
2716: new_data = xmalloc(len);
1.25 markus 2717: for (i = 0; i < data_len; i++)
1.72.2.1 jason 2718: snprintf(new_data + 2 * i, len - 2 * i,
2719: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2720:
2721: /* Send the request packet. */
1.51 markus 2722: if (compat20) {
2723: channel_request_start(client_session_id, "x11-req", 0);
2724: packet_put_char(0); /* XXX bool single connection */
2725: } else {
2726: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2727: }
2728: packet_put_cstring(proto);
2729: packet_put_cstring(new_data);
1.25 markus 2730: packet_put_int(screen_number);
2731: packet_send();
2732: packet_write_wait();
2733: xfree(new_data);
1.1 deraadt 2734: }
2735:
1.72.2.6! miod 2736:
! 2737: /* -- agent forwarding */
! 2738:
1.1 deraadt 2739: /* Sends a message to the server to request authentication fd forwarding. */
2740:
1.49 markus 2741: void
1.25 markus 2742: auth_request_forwarding()
1.1 deraadt 2743: {
1.25 markus 2744: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2745: packet_send();
2746: packet_write_wait();
1.1 deraadt 2747: }
2748:
1.27 markus 2749: /*
2750: * Returns the name of the forwarded authentication socket. Returns NULL if
2751: * there is no forwarded authentication socket. The returned value points to
2752: * a static buffer.
2753: */
1.1 deraadt 2754:
1.25 markus 2755: char *
2756: auth_get_socket_name()
1.1 deraadt 2757: {
1.72.2.6! miod 2758: return auth_sock_name;
1.1 deraadt 2759: }
2760:
1.12 markus 2761: /* removes the agent forwarding socket */
2762:
1.49 markus 2763: void
1.72.2.5 miod 2764: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2765: {
1.72.2.5 miod 2766: struct passwd *pw = _pw;
2767:
1.72.2.6! miod 2768: if (auth_sock_name) {
1.72.2.5 miod 2769: temporarily_use_uid(pw);
1.72.2.6! miod 2770: unlink(auth_sock_name);
! 2771: rmdir(auth_sock_dir);
! 2772: auth_sock_name = NULL;
1.72.2.5 miod 2773: restore_uid();
2774: }
1.12 markus 2775: }
2776:
1.27 markus 2777: /*
1.59 markus 2778: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2779: * This starts forwarding authentication requests.
2780: */
1.1 deraadt 2781:
1.59 markus 2782: int
1.25 markus 2783: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2784: {
1.72.2.6! miod 2785: Channel *nc;
! 2786: int sock;
1.25 markus 2787: struct sockaddr_un sunaddr;
2788:
1.72.2.6! miod 2789: if (auth_get_socket_name() != NULL) {
! 2790: error("authentication forwarding requested twice.");
! 2791: return 0;
! 2792: }
1.25 markus 2793:
2794: /* Temporarily drop privileged uid for mkdir/bind. */
1.72.2.4 jason 2795: temporarily_use_uid(pw);
1.25 markus 2796:
2797: /* Allocate a buffer for the socket name, and format the name. */
1.72.2.6! miod 2798: auth_sock_name = xmalloc(MAXPATHLEN);
! 2799: auth_sock_dir = xmalloc(MAXPATHLEN);
! 2800: strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.25 markus 2801:
2802: /* Create private directory for socket */
1.72.2.6! miod 2803: if (mkdtemp(auth_sock_dir) == NULL) {
! 2804: packet_send_debug("Agent forwarding disabled: "
! 2805: "mkdtemp() failed: %.100s", strerror(errno));
1.59 markus 2806: restore_uid();
1.72.2.6! miod 2807: xfree(auth_sock_name);
! 2808: xfree(auth_sock_dir);
! 2809: auth_sock_name = NULL;
! 2810: auth_sock_dir = NULL;
1.59 markus 2811: return 0;
2812: }
1.72.2.6! miod 2813: snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%d",
! 2814: auth_sock_dir, (int) getpid());
1.25 markus 2815:
1.72.2.5 miod 2816: /* delete agent socket on fatal() */
2817: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
2818:
1.25 markus 2819: /* Create the socket. */
2820: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2821: if (sock < 0)
2822: packet_disconnect("socket: %.100s", strerror(errno));
2823:
2824: /* Bind it to the name. */
2825: memset(&sunaddr, 0, sizeof(sunaddr));
2826: sunaddr.sun_family = AF_UNIX;
1.72.2.6! miod 2827: strncpy(sunaddr.sun_path, auth_sock_name,
1.25 markus 2828: sizeof(sunaddr.sun_path));
2829:
2830: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2831: packet_disconnect("bind: %.100s", strerror(errno));
2832:
2833: /* Restore the privileged uid. */
2834: restore_uid();
2835:
2836: /* Start listening on the socket. */
2837: if (listen(sock, 5) < 0)
2838: packet_disconnect("listen: %.100s", strerror(errno));
2839:
2840: /* Allocate a channel for the authentication agent socket. */
1.72.2.6! miod 2841: nc = channel_new("auth socket",
1.72.2.1 jason 2842: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2843: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2844: 0, xstrdup("auth socket"), 1);
1.72.2.6! miod 2845: if (nc == NULL) {
! 2846: error("auth_input_request_forwarding: channel_new failed");
! 2847: auth_sock_cleanup_proc(pw);
! 2848: fatal_remove_cleanup(auth_sock_cleanup_proc, pw);
! 2849: close(sock);
! 2850: return 0;
! 2851: }
! 2852: strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
1.59 markus 2853: return 1;
1.1 deraadt 2854: }
2855:
2856: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2857:
1.49 markus 2858: void
1.69 markus 2859: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2860: {
1.72.2.6! miod 2861: Channel *c = NULL;
! 2862: int remote_id, sock;
! 2863: char *name;
1.41 markus 2864:
2865: packet_integrity_check(plen, 4, type);
1.25 markus 2866:
2867: /* Read the remote channel number from the message. */
1.72.2.6! miod 2868: remote_id = packet_get_int();
1.25 markus 2869:
1.27 markus 2870: /*
2871: * Get a connection to the local authentication agent (this may again
2872: * get forwarded).
2873: */
1.25 markus 2874: sock = ssh_get_authentication_socket();
2875:
1.27 markus 2876: /*
2877: * If we could not connect the agent, send an error message back to
2878: * the server. This should never happen unless the agent dies,
2879: * because authentication forwarding is only enabled if we have an
2880: * agent.
2881: */
1.72.2.6! miod 2882: if (sock >= 0) {
! 2883: name = xstrdup("authentication agent connection");
! 2884: c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
! 2885: -1, 0, 0, 0, name, 1);
! 2886: if (c == NULL) {
! 2887: error("auth_input_open_request: channel_new failed");
! 2888: xfree(name);
! 2889: close(sock);
! 2890: } else {
! 2891: c->remote_id = remote_id;
! 2892: c->force_drain = 1;
! 2893: }
1.44 markus 2894: }
1.65 markus 2895: if (c == NULL) {
1.72.2.6! miod 2896: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
! 2897: packet_put_int(remote_id);
! 2898: } else {
! 2899: /* Send a confirmation to the remote host. */
! 2900: debug("Forwarding authentication connection.");
! 2901: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
! 2902: packet_put_int(remote_id);
! 2903: packet_put_int(c->self);
1.65 markus 2904: }
1.25 markus 2905: packet_send();
1.1 deraadt 2906: }
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