Annotation of src/usr.bin/ssh/channels.c, Revision 1.109.2.2
1.1 deraadt 1: /*
1.26 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * This file contains functions for generic socket connection forwarding.
6: * There is also code for initiating connection forwarding for X11 connections,
7: * arbitrary tcp/ip connections, and the authentication agent connection.
1.49 markus 8: *
1.67 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
15: *
1.44 markus 16: * SSH2 support added by Markus Friedl.
1.67 deraadt 17: * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
18: * Copyright (c) 1999 Dug Song. All rights reserved.
19: * Copyright (c) 1999 Theo de Raadt. All rights reserved.
20: *
21: * Redistribution and use in source and binary forms, with or without
22: * modification, are permitted provided that the following conditions
23: * are met:
24: * 1. Redistributions of source code must retain the above copyright
25: * notice, this list of conditions and the following disclaimer.
26: * 2. Redistributions in binary form must reproduce the above copyright
27: * notice, this list of conditions and the following disclaimer in the
28: * documentation and/or other materials provided with the distribution.
29: *
30: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26 deraadt 40: */
1.1 deraadt 41:
42: #include "includes.h"
1.109.2.2! jason 43: RCSID("$OpenBSD: channels.c,v 1.109.2.1 2001/06/12 22:31:48 jason Exp $");
1.82 markus 44:
45: #include <openssl/rsa.h>
46: #include <openssl/dsa.h>
1.1 deraadt 47:
48: #include "ssh.h"
1.82 markus 49: #include "ssh1.h"
50: #include "ssh2.h"
1.1 deraadt 51: #include "packet.h"
52: #include "xmalloc.h"
53: #include "buffer.h"
1.103 markus 54: #include "bufaux.h"
1.1 deraadt 55: #include "uidswap.h"
1.82 markus 56: #include "log.h"
57: #include "misc.h"
1.14 markus 58: #include "channels.h"
59: #include "nchan.h"
60: #include "compat.h"
1.82 markus 61: #include "canohost.h"
1.64 markus 62: #include "key.h"
63: #include "authfd.h"
1.44 markus 64:
1.1 deraadt 65: /* Maximum number of fake X11 displays to try. */
66: #define MAX_DISPLAYS 1000
67:
1.12 markus 68: /* Max len of agent socket */
69: #define MAX_SOCKET_NAME 100
70:
1.27 markus 71: /*
72: * Pointer to an array containing all allocated channels. The array is
73: * dynamically extended as needed.
74: */
1.1 deraadt 75: static Channel *channels = NULL;
76:
1.27 markus 77: /*
78: * Size of the channel array. All slots of the array must always be
79: * initialized (at least the type field); unused slots are marked with type
80: * SSH_CHANNEL_FREE.
81: */
1.1 deraadt 82: static int channels_alloc = 0;
83:
1.27 markus 84: /*
85: * Maximum file descriptor value used in any of the channels. This is
86: * updated in channel_allocate.
87: */
1.84 markus 88: static int channel_max_fd = 0;
1.1 deraadt 89:
1.12 markus 90: /* Name and directory of socket for authentication agent forwarding. */
1.1 deraadt 91: static char *channel_forwarded_auth_socket_name = NULL;
1.25 markus 92: static char *channel_forwarded_auth_socket_dir = NULL;
1.1 deraadt 93:
94: /* Saved X11 authentication protocol name. */
95: char *x11_saved_proto = NULL;
96:
97: /* Saved X11 authentication data. This is the real data. */
98: char *x11_saved_data = NULL;
1.77 markus 99: u_int x11_saved_data_len = 0;
1.1 deraadt 100:
1.27 markus 101: /*
102: * Fake X11 authentication data. This is what the server will be sending us;
103: * we should replace any occurrences of this by the real data.
104: */
1.1 deraadt 105: char *x11_fake_data = NULL;
1.77 markus 106: u_int x11_fake_data_len;
1.1 deraadt 107:
1.27 markus 108: /*
109: * Data structure for storing which hosts are permitted for forward requests.
110: * The local sides of any remote forwards are stored in this array to prevent
111: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
112: * network (which might be behind a firewall).
113: */
1.25 markus 114: typedef struct {
1.41 markus 115: char *host_to_connect; /* Connect to 'host'. */
116: u_short port_to_connect; /* Connect to 'port'. */
117: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 118: } ForwardPermission;
119:
120: /* List of all permitted host/port pairs to connect. */
121: static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
122: /* Number of permitted host/port pairs in the array. */
123: static int num_permitted_opens = 0;
1.27 markus 124: /*
125: * If this is true, all opens are permitted. This is the case on the server
126: * on which we have to trust the client anyway, and the user could do
127: * anything after logging in anyway.
128: */
1.1 deraadt 129: static int all_opens_permitted = 0;
130:
131: /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */
132: static int have_hostname_in_open = 0;
1.82 markus 133:
134: /* AF_UNSPEC or AF_INET or AF_INET6 */
135: extern int IPv4or6;
1.1 deraadt 136:
1.103 markus 137: void port_open_helper(Channel *c, char *rtype);
138:
1.1 deraadt 139: /* Sets specific protocol options. */
140:
1.49 markus 141: void
1.25 markus 142: channel_set_options(int hostname_in_open)
1.1 deraadt 143: {
1.25 markus 144: have_hostname_in_open = hostname_in_open;
1.1 deraadt 145: }
146:
1.41 markus 147: /* lookup channel by id */
148:
149: Channel *
150: channel_lookup(int id)
151: {
152: Channel *c;
1.63 provos 153: if (id < 0 || id > channels_alloc) {
1.41 markus 154: log("channel_lookup: %d: bad id", id);
155: return NULL;
156: }
157: c = &channels[id];
158: if (c->type == SSH_CHANNEL_FREE) {
159: log("channel_lookup: %d: bad id: channel free", id);
160: return NULL;
161: }
162: return c;
1.55 markus 163: }
164:
1.27 markus 165: /*
1.55 markus 166: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 167: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 168: */
1.1 deraadt 169:
1.52 markus 170: void
1.71 markus 171: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
172: int extusage, int nonblock)
1.1 deraadt 173: {
1.25 markus 174: /* Update the maximum file descriptor value. */
1.84 markus 175: channel_max_fd = MAX(channel_max_fd, rfd);
176: channel_max_fd = MAX(channel_max_fd, wfd);
177: channel_max_fd = MAX(channel_max_fd, efd);
178:
1.27 markus 179: /* XXX set close-on-exec -markus */
1.55 markus 180:
1.52 markus 181: c->rfd = rfd;
182: c->wfd = wfd;
183: c->sock = (rfd == wfd) ? rfd : -1;
184: c->efd = efd;
185: c->extended_usage = extusage;
1.71 markus 186:
1.91 markus 187: /* XXX ugly hack: nonblock is only set by the server */
188: if (nonblock && isatty(c->rfd)) {
1.94 markus 189: debug("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 190: c->isatty = 1;
191: if (!isatty(c->wfd)) {
1.94 markus 192: error("channel %d: wfd %d is not a tty?",
1.91 markus 193: c->self, c->wfd);
194: }
195: } else {
196: c->isatty = 0;
197: }
198:
1.71 markus 199: /* enable nonblocking mode */
200: if (nonblock) {
201: if (rfd != -1)
202: set_nonblock(rfd);
203: if (wfd != -1)
204: set_nonblock(wfd);
205: if (efd != -1)
206: set_nonblock(efd);
207: }
1.52 markus 208: }
209:
210: /*
211: * Allocate a new channel object and set its type and socket. This will cause
212: * remote_name to be freed.
213: */
214:
215: int
216: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.71 markus 217: int window, int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 218: {
219: int i, found;
220: Channel *c;
1.25 markus 221:
222: /* Do initial allocation if this is the first call. */
223: if (channels_alloc == 0) {
1.44 markus 224: chan_init();
1.25 markus 225: channels_alloc = 10;
226: channels = xmalloc(channels_alloc * sizeof(Channel));
227: for (i = 0; i < channels_alloc; i++)
228: channels[i].type = SSH_CHANNEL_FREE;
1.27 markus 229: /*
230: * Kludge: arrange a call to channel_stop_listening if we
231: * terminate with fatal().
232: */
1.25 markus 233: fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL);
234: }
235: /* Try to find a free slot where to put the new channel. */
236: for (found = -1, i = 0; i < channels_alloc; i++)
237: if (channels[i].type == SSH_CHANNEL_FREE) {
238: /* Found a free slot. */
239: found = i;
240: break;
241: }
242: if (found == -1) {
1.27 markus 243: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 244: found = channels_alloc;
245: channels_alloc += 10;
1.70 markus 246: debug2("channel: expanding %d", channels_alloc);
1.25 markus 247: channels = xrealloc(channels, channels_alloc * sizeof(Channel));
248: for (i = found; i < channels_alloc; i++)
249: channels[i].type = SSH_CHANNEL_FREE;
250: }
251: /* Initialize and return new channel number. */
252: c = &channels[found];
253: buffer_init(&c->input);
254: buffer_init(&c->output);
1.41 markus 255: buffer_init(&c->extended);
1.25 markus 256: chan_init_iostates(c);
1.71 markus 257: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.25 markus 258: c->self = found;
259: c->type = type;
1.41 markus 260: c->ctype = ctype;
1.51 markus 261: c->local_window = window;
262: c->local_window_max = window;
263: c->local_consumed = 0;
264: c->local_maxpacket = maxpack;
1.25 markus 265: c->remote_id = -1;
266: c->remote_name = remote_name;
1.41 markus 267: c->remote_window = 0;
268: c->remote_maxpacket = 0;
269: c->cb_fn = NULL;
270: c->cb_arg = NULL;
271: c->cb_event = 0;
272: c->dettach_user = NULL;
1.65 markus 273: c->input_filter = NULL;
1.25 markus 274: debug("channel %d: new [%s]", found, remote_name);
275: return found;
1.1 deraadt 276: }
1.52 markus 277: /* old interface XXX */
1.49 markus 278: int
1.41 markus 279: channel_allocate(int type, int sock, char *remote_name)
280: {
1.71 markus 281: return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
1.41 markus 282: }
1.1 deraadt 283:
1.52 markus 284:
285: /* Close all channel fd/socket. */
286:
287: void
288: channel_close_fds(Channel *c)
289: {
290: if (c->sock != -1) {
291: close(c->sock);
292: c->sock = -1;
293: }
294: if (c->rfd != -1) {
295: close(c->rfd);
296: c->rfd = -1;
297: }
298: if (c->wfd != -1) {
299: close(c->wfd);
300: c->wfd = -1;
301: }
302: if (c->efd != -1) {
303: close(c->efd);
304: c->efd = -1;
305: }
306: }
307:
308: /* Free the channel and close its fd/socket. */
1.1 deraadt 309:
1.49 markus 310: void
1.41 markus 311: channel_free(int id)
1.1 deraadt 312: {
1.41 markus 313: Channel *c = channel_lookup(id);
1.79 markus 314: char *s = channel_open_message();
315:
1.41 markus 316: if (c == NULL)
317: packet_disconnect("channel free: bad local channel %d", id);
1.79 markus 318: debug("channel_free: channel %d: status: %s", id, s);
319: xfree(s);
320:
1.44 markus 321: if (c->dettach_user != NULL) {
322: debug("channel_free: channel %d: dettaching channel user", id);
323: c->dettach_user(c->self, NULL);
324: }
1.54 markus 325: if (c->sock != -1)
326: shutdown(c->sock, SHUT_RDWR);
1.52 markus 327: channel_close_fds(c);
1.41 markus 328: buffer_free(&c->input);
329: buffer_free(&c->output);
330: buffer_free(&c->extended);
331: c->type = SSH_CHANNEL_FREE;
332: if (c->remote_name) {
333: xfree(c->remote_name);
334: c->remote_name = NULL;
1.25 markus 335: }
1.1 deraadt 336: }
337:
1.27 markus 338: /*
1.41 markus 339: * 'channel_pre*' are called just before select() to add any bits relevant to
340: * channels in the select bitmasks.
341: */
342: /*
343: * 'channel_post*': perform any appropriate operations for channels which
344: * have events pending.
1.27 markus 345: */
1.41 markus 346: typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
347: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
348: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
349:
350: void
351: channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
352: {
353: FD_SET(c->sock, readset);
354: }
355:
356: void
1.75 markus 357: channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
358: {
359: debug3("channel %d: waiting for connection", c->self);
360: FD_SET(c->sock, writeset);
361: }
362:
363: void
1.41 markus 364: channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
365: {
366: if (buffer_len(&c->input) < packet_get_maxsize())
367: FD_SET(c->sock, readset);
368: if (buffer_len(&c->output) > 0)
369: FD_SET(c->sock, writeset);
370: }
1.1 deraadt 371:
1.41 markus 372: void
373: channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
374: {
375: /* test whether sockets are 'alive' for read/write */
376: if (c->istate == CHAN_INPUT_OPEN)
377: if (buffer_len(&c->input) < packet_get_maxsize())
378: FD_SET(c->sock, readset);
379: if (c->ostate == CHAN_OUTPUT_OPEN ||
380: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
381: if (buffer_len(&c->output) > 0) {
382: FD_SET(c->sock, writeset);
383: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
384: chan_obuf_empty(c);
385: }
386: }
387: }
388:
389: void
1.44 markus 390: channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
391: {
392: if (c->istate == CHAN_INPUT_OPEN &&
393: c->remote_window > 0 &&
394: buffer_len(&c->input) < c->remote_window)
395: FD_SET(c->rfd, readset);
396: if (c->ostate == CHAN_OUTPUT_OPEN ||
397: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
398: if (buffer_len(&c->output) > 0) {
399: FD_SET(c->wfd, writeset);
400: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
401: chan_obuf_empty(c);
402: }
403: }
404: /** XXX check close conditions, too */
405: if (c->efd != -1) {
406: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
407: buffer_len(&c->extended) > 0)
408: FD_SET(c->efd, writeset);
409: else if (c->extended_usage == CHAN_EXTENDED_READ &&
410: buffer_len(&c->extended) < c->remote_window)
411: FD_SET(c->efd, readset);
412: }
413: }
414:
415: void
1.41 markus 416: channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
417: {
418: if (buffer_len(&c->input) == 0) {
419: packet_start(SSH_MSG_CHANNEL_CLOSE);
420: packet_put_int(c->remote_id);
421: packet_send();
422: c->type = SSH_CHANNEL_CLOSED;
1.105 markus 423: debug("channel %d: closing after input drain.", c->self);
1.41 markus 424: }
425: }
426:
427: void
428: channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
429: {
430: if (buffer_len(&c->output) == 0)
431: channel_free(c->self);
1.49 markus 432: else
1.41 markus 433: FD_SET(c->sock, writeset);
434: }
435:
436: /*
437: * This is a special state for X11 authentication spoofing. An opened X11
438: * connection (when authentication spoofing is being done) remains in this
439: * state until the first packet has been completely read. The authentication
440: * data in that packet is then substituted by the real data if it matches the
441: * fake data, and the channel is put into normal mode.
1.51 markus 442: * XXX All this happens at the client side.
1.41 markus 443: */
444: int
445: x11_open_helper(Channel *c)
1.1 deraadt 446: {
1.77 markus 447: u_char *ucp;
448: u_int proto_len, data_len;
1.25 markus 449:
1.41 markus 450: /* Check if the fixed size part of the packet is in buffer. */
451: if (buffer_len(&c->output) < 12)
452: return 0;
453:
454: /* Parse the lengths of variable-length fields. */
1.77 markus 455: ucp = (u_char *) buffer_ptr(&c->output);
1.41 markus 456: if (ucp[0] == 0x42) { /* Byte order MSB first. */
457: proto_len = 256 * ucp[6] + ucp[7];
458: data_len = 256 * ucp[8] + ucp[9];
459: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
460: proto_len = ucp[6] + 256 * ucp[7];
461: data_len = ucp[8] + 256 * ucp[9];
462: } else {
463: debug("Initial X11 packet contains bad byte order byte: 0x%x",
464: ucp[0]);
465: return -1;
466: }
467:
468: /* Check if the whole packet is in buffer. */
469: if (buffer_len(&c->output) <
470: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
471: return 0;
472:
473: /* Check if authentication protocol matches. */
474: if (proto_len != strlen(x11_saved_proto) ||
475: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
476: debug("X11 connection uses different authentication protocol.");
477: return -1;
478: }
479: /* Check if authentication data matches our fake data. */
480: if (data_len != x11_fake_data_len ||
481: memcmp(ucp + 12 + ((proto_len + 3) & ~3),
482: x11_fake_data, x11_fake_data_len) != 0) {
483: debug("X11 auth data does not match fake data.");
484: return -1;
485: }
486: /* Check fake data length */
487: if (x11_fake_data_len != x11_saved_data_len) {
488: error("X11 fake_data_len %d != saved_data_len %d",
489: x11_fake_data_len, x11_saved_data_len);
490: return -1;
491: }
492: /*
493: * Received authentication protocol and data match
494: * our fake data. Substitute the fake data with real
495: * data.
496: */
497: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
498: x11_saved_data, x11_saved_data_len);
499: return 1;
500: }
501:
502: void
503: channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
504: {
505: int ret = x11_open_helper(c);
506: if (ret == 1) {
507: /* Start normal processing for the channel. */
508: c->type = SSH_CHANNEL_OPEN;
1.47 markus 509: channel_pre_open_13(c, readset, writeset);
1.41 markus 510: } else if (ret == -1) {
511: /*
512: * We have received an X11 connection that has bad
513: * authentication information.
514: */
1.98 millert 515: log("X11 connection rejected because of wrong authentication.");
1.41 markus 516: buffer_clear(&c->input);
517: buffer_clear(&c->output);
518: close(c->sock);
519: c->sock = -1;
520: c->type = SSH_CHANNEL_CLOSED;
521: packet_start(SSH_MSG_CHANNEL_CLOSE);
522: packet_put_int(c->remote_id);
523: packet_send();
524: }
525: }
1.25 markus 526:
1.41 markus 527: void
1.51 markus 528: channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
1.41 markus 529: {
530: int ret = x11_open_helper(c);
531: if (ret == 1) {
532: c->type = SSH_CHANNEL_OPEN;
1.57 markus 533: if (compat20)
534: channel_pre_open_20(c, readset, writeset);
535: else
536: channel_pre_open_15(c, readset, writeset);
1.41 markus 537: } else if (ret == -1) {
538: debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.51 markus 539: chan_read_failed(c); /** force close? */
1.41 markus 540: chan_write_failed(c);
541: debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
542: }
543: }
1.25 markus 544:
1.104 markus 545: /* try to decode a socks4 header */
546: int
547: channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
1.103 markus 548: {
549: u_char *p, *host;
1.109 markus 550: int len, have, i, found;
1.104 markus 551: char username[256];
1.103 markus 552: struct {
553: u_int8_t version;
554: u_int8_t command;
555: u_int16_t dest_port;
1.104 markus 556: struct in_addr dest_addr;
1.103 markus 557: } s4_req, s4_rsp;
558:
1.104 markus 559: debug2("channel %d: decode socks4", c->self);
1.109 markus 560:
561: have = buffer_len(&c->input);
562: len = sizeof(s4_req);
563: if (have < len)
564: return 0;
565: p = buffer_ptr(&c->input);
566: for (found = 0, i = len; i < have; i++) {
567: if (p[i] == '\0') {
568: found = 1;
569: break;
570: }
571: if (i > 1024) {
572: /* the peer is probably sending garbage */
573: debug("channel %d: decode socks4: too long",
574: c->self);
575: return -1;
576: }
577: }
578: if (!found)
579: return 0;
1.103 markus 580: buffer_get(&c->input, (char *)&s4_req.version, 1);
581: buffer_get(&c->input, (char *)&s4_req.command, 1);
582: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 583: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 584: have = buffer_len(&c->input);
1.103 markus 585: p = buffer_ptr(&c->input);
586: len = strlen(p);
1.106 markus 587: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.103 markus 588: if (len > have)
1.104 markus 589: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 590: c->self, len, have);
591: strlcpy(username, p, sizeof(username));
592: buffer_consume(&c->input, len);
593: buffer_consume(&c->input, 1); /* trailing '\0' */
594:
1.104 markus 595: host = inet_ntoa(s4_req.dest_addr);
1.103 markus 596: strlcpy(c->path, host, sizeof(c->path));
597: c->host_port = ntohs(s4_req.dest_port);
598:
1.106 markus 599: debug("channel %d: dynamic request: socks4 host %s port %u command %u",
600: c->self, host, c->host_port, s4_req.command);
1.103 markus 601:
1.104 markus 602: if (s4_req.command != 1) {
603: debug("channel %d: cannot handle: socks4 cn %d",
604: c->self, s4_req.command);
605: return -1;
1.103 markus 606: }
1.104 markus 607: s4_rsp.version = 0; /* vn: 0 for reply */
608: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 609: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 610: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.103 markus 611: buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
1.104 markus 612: return 1;
613: }
614:
615: /* dynamic port forwarding */
616: void
617: channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
618: {
619: u_char *p;
620: int have, ret;
1.103 markus 621:
1.104 markus 622: have = buffer_len(&c->input);
623:
624: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 625: /* buffer_dump(&c->input); */
1.104 markus 626: /* check if the fixed size part of the packet is in buffer. */
627: if (have < 4) {
628: /* need more */
629: FD_SET(c->sock, readset);
630: return;
631: }
632: /* try to guess the protocol */
633: p = buffer_ptr(&c->input);
634: switch (p[0]) {
635: case 0x04:
636: ret = channel_decode_socks4(c, readset, writeset);
637: break;
638: default:
639: ret = -1;
640: break;
641: }
642: if (ret < 0) {
643: channel_free(c->self);
644: } else if (ret == 0) {
645: debug2("channel %d: pre_dynamic: need more", c->self);
646: /* need more */
647: FD_SET(c->sock, readset);
648: } else {
649: /* switch to the next state */
650: c->type = SSH_CHANNEL_OPENING;
651: port_open_helper(c, "direct-tcpip");
652: }
1.103 markus 653: }
654:
1.41 markus 655: /* This is our fake X11 server socket. */
656: void
657: channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
658: {
659: struct sockaddr addr;
660: int newsock, newch;
661: socklen_t addrlen;
1.85 markus 662: char buf[16384], *remote_ipaddr;
1.51 markus 663: int remote_port;
1.25 markus 664:
1.41 markus 665: if (FD_ISSET(c->sock, readset)) {
666: debug("X11 connection requested.");
667: addrlen = sizeof(addr);
668: newsock = accept(c->sock, &addr, &addrlen);
669: if (newsock < 0) {
670: error("accept: %.100s", strerror(errno));
671: return;
672: }
1.85 markus 673: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 674: remote_port = get_peer_port(newsock);
1.41 markus 675: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 676: remote_ipaddr, remote_port);
1.51 markus 677:
678: newch = channel_new("x11",
679: SSH_CHANNEL_OPENING, newsock, newsock, -1,
680: c->local_window_max, c->local_maxpacket,
1.71 markus 681: 0, xstrdup(buf), 1);
1.51 markus 682: if (compat20) {
683: packet_start(SSH2_MSG_CHANNEL_OPEN);
684: packet_put_cstring("x11");
685: packet_put_int(newch);
686: packet_put_int(c->local_window_max);
687: packet_put_int(c->local_maxpacket);
1.85 markus 688: /* originator ipaddr and port */
689: packet_put_cstring(remote_ipaddr);
1.57 markus 690: if (datafellows & SSH_BUG_X11FWD) {
691: debug("ssh2 x11 bug compat mode");
692: } else {
693: packet_put_int(remote_port);
694: }
1.51 markus 695: packet_send();
696: } else {
697: packet_start(SSH_SMSG_X11_OPEN);
698: packet_put_int(newch);
699: if (have_hostname_in_open)
700: packet_put_string(buf, strlen(buf));
701: packet_send();
702: }
1.85 markus 703: xfree(remote_ipaddr);
1.41 markus 704: }
705: }
1.25 markus 706:
1.103 markus 707: void
708: port_open_helper(Channel *c, char *rtype)
709: {
710: int direct;
711: char buf[1024];
712: char *remote_ipaddr = get_peer_ipaddr(c->sock);
713: u_short remote_port = get_peer_port(c->sock);
714:
715: direct = (strcmp(rtype, "direct-tcpip") == 0);
716:
717: snprintf(buf, sizeof buf,
718: "%s: listening port %d for %.100s port %d, "
719: "connect from %.200s port %d",
720: rtype, c->listening_port, c->path, c->host_port,
721: remote_ipaddr, remote_port);
722:
723: xfree(c->remote_name);
724: c->remote_name = xstrdup(buf);
725:
726: if (compat20) {
727: packet_start(SSH2_MSG_CHANNEL_OPEN);
728: packet_put_cstring(rtype);
729: packet_put_int(c->self);
730: packet_put_int(c->local_window_max);
731: packet_put_int(c->local_maxpacket);
732: if (direct) {
733: /* target host, port */
734: packet_put_cstring(c->path);
735: packet_put_int(c->host_port);
736: } else {
737: /* listen address, port */
738: packet_put_cstring(c->path);
739: packet_put_int(c->listening_port);
740: }
741: /* originator host and port */
742: packet_put_cstring(remote_ipaddr);
743: packet_put_int(remote_port);
744: packet_send();
745: } else {
746: packet_start(SSH_MSG_PORT_OPEN);
747: packet_put_int(c->self);
748: packet_put_cstring(c->path);
749: packet_put_int(c->host_port);
750: if (have_hostname_in_open)
751: packet_put_cstring(c->remote_name);
752: packet_send();
753: }
754: xfree(remote_ipaddr);
755: }
756:
1.41 markus 757: /*
758: * This socket is listening for connections to a forwarded TCP/IP port.
759: */
760: void
761: channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
762: {
1.103 markus 763: Channel *nc;
1.41 markus 764: struct sockaddr addr;
1.103 markus 765: int newsock, newch, nextstate;
1.41 markus 766: socklen_t addrlen;
1.103 markus 767: char *rtype;
1.73 markus 768:
1.41 markus 769: if (FD_ISSET(c->sock, readset)) {
770: debug("Connection to port %d forwarding "
771: "to %.100s port %d requested.",
772: c->listening_port, c->path, c->host_port);
1.103 markus 773:
774: rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
775: "forwarded-tcpip" : "direct-tcpip";
1.109.2.2! jason 776: nextstate = (c->host_port == 0 &&
! 777: c->type != SSH_CHANNEL_RPORT_LISTENER) ?
! 778: SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
1.103 markus 779:
1.41 markus 780: addrlen = sizeof(addr);
781: newsock = accept(c->sock, &addr, &addrlen);
782: if (newsock < 0) {
783: error("accept: %.100s", strerror(errno));
784: return;
785: }
1.73 markus 786: newch = channel_new(rtype,
1.103 markus 787: nextstate, newsock, newsock, -1,
1.41 markus 788: c->local_window_max, c->local_maxpacket,
1.103 markus 789: 0, xstrdup(rtype), 1);
790:
791: nc = channel_lookup(newch);
792: if (nc == NULL) {
793: error("xxx: no new channel:");
794: return;
1.41 markus 795: }
1.103 markus 796: nc->listening_port = c->listening_port;
797: nc->host_port = c->host_port;
798: strlcpy(nc->path, c->path, sizeof(nc->path));
799:
800: if (nextstate != SSH_CHANNEL_DYNAMIC)
801: port_open_helper(nc, rtype);
1.41 markus 802: }
803: }
1.25 markus 804:
1.41 markus 805: /*
806: * This is the authentication agent socket listening for connections from
807: * clients.
808: */
809: void
810: channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
811: {
812: struct sockaddr addr;
813: int newsock, newch;
814: socklen_t addrlen;
1.25 markus 815:
1.41 markus 816: if (FD_ISSET(c->sock, readset)) {
817: addrlen = sizeof(addr);
818: newsock = accept(c->sock, &addr, &addrlen);
819: if (newsock < 0) {
820: error("accept from auth socket: %.100s", strerror(errno));
821: return;
822: }
1.73 markus 823: newch = channel_new("accepted auth socket",
824: SSH_CHANNEL_OPENING, newsock, newsock, -1,
825: c->local_window_max, c->local_maxpacket,
826: 0, xstrdup("accepted auth socket"), 1);
827: if (compat20) {
828: packet_start(SSH2_MSG_CHANNEL_OPEN);
829: packet_put_cstring("auth-agent@openssh.com");
830: packet_put_int(newch);
831: packet_put_int(c->local_window_max);
832: packet_put_int(c->local_maxpacket);
833: } else {
834: packet_start(SSH_SMSG_AGENT_OPEN);
835: packet_put_int(newch);
836: }
1.41 markus 837: packet_send();
838: }
839: }
1.25 markus 840:
1.75 markus 841: void
842: channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
843: {
844: if (FD_ISSET(c->sock, writeset)) {
845: int err = 0;
846: int sz = sizeof(err);
847: c->type = SSH_CHANNEL_OPEN;
1.89 stevesk 848: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
1.75 markus 849: debug("getsockopt SO_ERROR failed");
850: } else {
851: if (err == 0) {
852: debug("channel %d: connected)", c->self);
853: } else {
854: debug("channel %d: not connected: %s",
855: c->self, strerror(err));
856: chan_read_failed(c);
857: chan_write_failed(c);
858: }
859: }
860: }
861: }
862:
1.41 markus 863: int
864: channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
865: {
866: char buf[16*1024];
867: int len;
1.25 markus 868:
1.41 markus 869: if (c->rfd != -1 &&
870: FD_ISSET(c->rfd, readset)) {
871: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 872: if (len < 0 && (errno == EINTR || errno == EAGAIN))
873: return 1;
1.41 markus 874: if (len <= 0) {
1.51 markus 875: debug("channel %d: read<=0 rfd %d len %d",
1.41 markus 876: c->self, c->rfd, len);
1.104 markus 877: if (c->type != SSH_CHANNEL_OPEN) {
878: debug("channel %d: not open", c->self);
1.103 markus 879: channel_free(c->self);
880: return -1;
1.104 markus 881: } else if (compat13) {
1.41 markus 882: buffer_consume(&c->output, buffer_len(&c->output));
883: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.105 markus 884: debug("channel %d: status set to input draining.", c->self);
1.25 markus 885: } else {
1.41 markus 886: chan_read_failed(c);
1.25 markus 887: }
1.41 markus 888: return -1;
889: }
1.65 markus 890: if(c->input_filter != NULL) {
1.66 markus 891: if (c->input_filter(c, buf, len) == -1) {
1.105 markus 892: debug("channel %d: filter stops", c->self);
1.65 markus 893: chan_read_failed(c);
894: }
895: } else {
896: buffer_append(&c->input, buf, len);
897: }
1.41 markus 898: }
899: return 1;
900: }
901: int
902: channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
903: {
1.95 markus 904: struct termios tio;
1.41 markus 905: int len;
1.25 markus 906:
1.41 markus 907: /* Send buffered output data to the socket. */
908: if (c->wfd != -1 &&
909: FD_ISSET(c->wfd, writeset) &&
910: buffer_len(&c->output) > 0) {
911: len = write(c->wfd, buffer_ptr(&c->output),
1.53 markus 912: buffer_len(&c->output));
913: if (len < 0 && (errno == EINTR || errno == EAGAIN))
914: return 1;
1.41 markus 915: if (len <= 0) {
1.104 markus 916: if (c->type != SSH_CHANNEL_OPEN) {
917: debug("channel %d: not open", c->self);
918: channel_free(c->self);
919: return -1;
920: } else if (compat13) {
1.41 markus 921: buffer_consume(&c->output, buffer_len(&c->output));
1.105 markus 922: debug("channel %d: status set to input draining.", c->self);
1.41 markus 923: c->type = SSH_CHANNEL_INPUT_DRAINING;
924: } else {
925: chan_write_failed(c);
926: }
927: return -1;
1.91 markus 928: }
929: if (compat20 && c->isatty) {
930: if (tcgetattr(c->wfd, &tio) == 0 &&
931: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
932: /*
933: * Simulate echo to reduce the impact of
1.96 markus 934: * traffic analysis. We need to match the
1.95 markus 935: * size of a SSH2_MSG_CHANNEL_DATA message
936: * (4 byte channel id + data)
1.91 markus 937: */
1.95 markus 938: packet_send_ignore(4 + len);
1.91 markus 939: packet_send();
940: }
1.25 markus 941: }
1.41 markus 942: buffer_consume(&c->output, len);
1.44 markus 943: if (compat20 && len > 0) {
944: c->local_consumed += len;
945: }
946: }
947: return 1;
948: }
949: int
950: channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
951: {
952: char buf[16*1024];
953: int len;
954:
1.45 markus 955: /** XXX handle drain efd, too */
1.44 markus 956: if (c->efd != -1) {
957: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
958: FD_ISSET(c->efd, writeset) &&
959: buffer_len(&c->extended) > 0) {
960: len = write(c->efd, buffer_ptr(&c->extended),
961: buffer_len(&c->extended));
1.70 markus 962: debug2("channel %d: written %d to efd %d",
1.44 markus 963: c->self, len, c->efd);
1.93 markus 964: if (len < 0 && (errno == EINTR || errno == EAGAIN))
965: return 1;
966: if (len <= 0) {
967: debug2("channel %d: closing write-efd %d",
968: c->self, c->efd);
969: close(c->efd);
970: c->efd = -1;
971: } else {
1.44 markus 972: buffer_consume(&c->extended, len);
973: c->local_consumed += len;
974: }
975: } else if (c->extended_usage == CHAN_EXTENDED_READ &&
976: FD_ISSET(c->efd, readset)) {
977: len = read(c->efd, buf, sizeof(buf));
1.70 markus 978: debug2("channel %d: read %d from efd %d",
1.44 markus 979: c->self, len, c->efd);
1.93 markus 980: if (len < 0 && (errno == EINTR || errno == EAGAIN))
981: return 1;
982: if (len <= 0) {
983: debug2("channel %d: closing read-efd %d",
1.45 markus 984: c->self, c->efd);
985: close(c->efd);
986: c->efd = -1;
1.93 markus 987: } else {
1.44 markus 988: buffer_append(&c->extended, buf, len);
1.93 markus 989: }
1.44 markus 990: }
991: }
992: return 1;
993: }
994: int
1.93 markus 995: channel_check_window(Channel *c)
1.44 markus 996: {
1.104 markus 997: if (c->type == SSH_CHANNEL_OPEN &&
998: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.44 markus 999: c->local_window < c->local_window_max/2 &&
1000: c->local_consumed > 0) {
1001: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1002: packet_put_int(c->remote_id);
1003: packet_put_int(c->local_consumed);
1004: packet_send();
1.70 markus 1005: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1006: c->self, c->local_window,
1007: c->local_consumed);
1008: c->local_window += c->local_consumed;
1009: c->local_consumed = 0;
1.1 deraadt 1010: }
1.41 markus 1011: return 1;
1.1 deraadt 1012: }
1013:
1.41 markus 1014: void
1015: channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
1016: {
1017: channel_handle_rfd(c, readset, writeset);
1018: channel_handle_wfd(c, readset, writeset);
1019: }
1.1 deraadt 1020:
1.41 markus 1021: void
1.44 markus 1022: channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
1023: {
1024: channel_handle_rfd(c, readset, writeset);
1025: channel_handle_wfd(c, readset, writeset);
1026: channel_handle_efd(c, readset, writeset);
1.93 markus 1027:
1028: channel_check_window(c);
1.44 markus 1029: }
1030:
1031: void
1.41 markus 1032: channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
1.1 deraadt 1033: {
1.41 markus 1034: int len;
1035: /* Send buffered output data to the socket. */
1036: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1037: len = write(c->sock, buffer_ptr(&c->output),
1038: buffer_len(&c->output));
1039: if (len <= 0)
1040: buffer_consume(&c->output, buffer_len(&c->output));
1041: else
1042: buffer_consume(&c->output, len);
1043: }
1044: }
1.25 markus 1045:
1.41 markus 1046: void
1.44 markus 1047: channel_handler_init_20(void)
1048: {
1049: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
1.51 markus 1050: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1051: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1052: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1053: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1054: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1055: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1056: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.44 markus 1057:
1058: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
1059: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1060: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1061: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1062: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1063: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1064: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
1.44 markus 1065: }
1066:
1067: void
1.41 markus 1068: channel_handler_init_13(void)
1069: {
1070: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1071: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1072: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1073: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1074: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1075: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1076: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1077: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1078: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1079:
1.41 markus 1080: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1081: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1082: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1083: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1084: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1085: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1086: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1087: }
1.25 markus 1088:
1.41 markus 1089: void
1090: channel_handler_init_15(void)
1091: {
1092: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
1.51 markus 1093: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1094: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1095: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1096: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1097: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1098: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1099:
1.41 markus 1100: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1101: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1102: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1103: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
1.75 markus 1104: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.104 markus 1105: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
1.41 markus 1106: }
1.27 markus 1107:
1.41 markus 1108: void
1109: channel_handler_init(void)
1110: {
1111: int i;
1112: for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1113: channel_pre[i] = NULL;
1114: channel_post[i] = NULL;
1115: }
1.44 markus 1116: if (compat20)
1117: channel_handler_init_20();
1118: else if (compat13)
1.41 markus 1119: channel_handler_init_13();
1120: else
1121: channel_handler_init_15();
1122: }
1.25 markus 1123:
1.49 markus 1124: void
1.41 markus 1125: channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
1126: {
1127: static int did_init = 0;
1128: int i;
1129: Channel *c;
1.25 markus 1130:
1.41 markus 1131: if (!did_init) {
1132: channel_handler_init();
1133: did_init = 1;
1134: }
1135: for (i = 0; i < channels_alloc; i++) {
1136: c = &channels[i];
1137: if (c->type == SSH_CHANNEL_FREE)
1138: continue;
1139: if (ftab[c->type] == NULL)
1.25 markus 1140: continue;
1.41 markus 1141: (*ftab[c->type])(c, readset, writeset);
1.93 markus 1142: if (chan_is_dead(c)) {
1143: /*
1144: * we have to remove the fd's from the select mask
1145: * before the channels are free'd and the fd's are
1146: * closed
1147: */
1148: if (c->wfd != -1)
1149: FD_CLR(c->wfd, writeset);
1150: if (c->rfd != -1)
1151: FD_CLR(c->rfd, readset);
1152: if (c->efd != -1) {
1153: if (c->extended_usage == CHAN_EXTENDED_READ)
1154: FD_CLR(c->efd, readset);
1155: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1156: FD_CLR(c->efd, writeset);
1157: }
1158: channel_free(c->self);
1159: }
1.1 deraadt 1160: }
1161: }
1162:
1.49 markus 1163: void
1.100 markus 1164: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1165: int rekeying)
1.41 markus 1166: {
1.84 markus 1167: int n;
1168: u_int sz;
1169:
1170: n = MAX(*maxfdp, channel_max_fd);
1171:
1172: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1173: if (*readsetp == NULL || n > *maxfdp) {
1174: if (*readsetp)
1175: xfree(*readsetp);
1176: if (*writesetp)
1177: xfree(*writesetp);
1178: *readsetp = xmalloc(sz);
1179: *writesetp = xmalloc(sz);
1180: *maxfdp = n;
1181: }
1182: memset(*readsetp, 0, sz);
1183: memset(*writesetp, 0, sz);
1184:
1.100 markus 1185: if (!rekeying)
1186: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 1187: }
1188:
1.49 markus 1189: void
1.41 markus 1190: channel_after_select(fd_set * readset, fd_set * writeset)
1191: {
1192: channel_handler(channel_post, readset, writeset);
1193: }
1194:
1.84 markus 1195: /* If there is data to send to the connection, enqueue some of it now. */
1.1 deraadt 1196:
1.49 markus 1197: void
1.25 markus 1198: channel_output_poll()
1.1 deraadt 1199: {
1.25 markus 1200: int len, i;
1.41 markus 1201: Channel *c;
1.1 deraadt 1202:
1.25 markus 1203: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1204: c = &channels[i];
1.37 markus 1205:
1.27 markus 1206: /* We are only interested in channels that can have buffered incoming data. */
1.37 markus 1207: if (compat13) {
1.41 markus 1208: if (c->type != SSH_CHANNEL_OPEN &&
1209: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 1210: continue;
1211: } else {
1.41 markus 1212: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 1213: continue;
1214: }
1.46 markus 1215: if (compat20 &&
1216: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 1217: /* XXX is this true? */
1.97 markus 1218: debug2("channel %d: no data after CLOSE", c->self);
1.44 markus 1219: continue;
1220: }
1.25 markus 1221:
1222: /* Get the amount of buffered data for this channel. */
1.93 markus 1223: if ((c->istate == CHAN_INPUT_OPEN ||
1224: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1225: (len = buffer_len(&c->input)) > 0) {
1.27 markus 1226: /* Send some data for the other side over the secure connection. */
1.44 markus 1227: if (compat20) {
1228: if (len > c->remote_window)
1229: len = c->remote_window;
1230: if (len > c->remote_maxpacket)
1231: len = c->remote_maxpacket;
1.25 markus 1232: } else {
1.44 markus 1233: if (packet_is_interactive()) {
1234: if (len > 1024)
1235: len = 512;
1236: } else {
1237: /* Keep the packets at reasonable size. */
1238: if (len > packet_get_maxsize()/2)
1239: len = packet_get_maxsize()/2;
1240: }
1.25 markus 1241: }
1.41 markus 1242: if (len > 0) {
1.44 markus 1243: packet_start(compat20 ?
1244: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 1245: packet_put_int(c->remote_id);
1246: packet_put_string(buffer_ptr(&c->input), len);
1247: packet_send();
1248: buffer_consume(&c->input, len);
1249: c->remote_window -= len;
1250: }
1251: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 1252: if (compat13)
1253: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 1254: /*
1255: * input-buffer is empty and read-socket shutdown:
1256: * tell peer, that we will not send more data: send IEOF
1257: */
1.41 markus 1258: chan_ibuf_empty(c);
1.25 markus 1259: }
1.44 markus 1260: /* Send extended data, i.e. stderr */
1261: if (compat20 &&
1262: c->remote_window > 0 &&
1263: (len = buffer_len(&c->extended)) > 0 &&
1264: c->extended_usage == CHAN_EXTENDED_READ) {
1.93 markus 1265: debug2("channel %d: rwin %d elen %d euse %d",
1266: c->self, c->remote_window, buffer_len(&c->extended),
1267: c->extended_usage);
1.44 markus 1268: if (len > c->remote_window)
1269: len = c->remote_window;
1270: if (len > c->remote_maxpacket)
1271: len = c->remote_maxpacket;
1272: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
1273: packet_put_int(c->remote_id);
1274: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
1275: packet_put_string(buffer_ptr(&c->extended), len);
1276: packet_send();
1277: buffer_consume(&c->extended, len);
1278: c->remote_window -= len;
1.93 markus 1279: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 1280: }
1.25 markus 1281: }
1.1 deraadt 1282: }
1283:
1.27 markus 1284: /*
1285: * This is called when a packet of type CHANNEL_DATA has just been received.
1286: * The message type has already been consumed, but channel number and data is
1287: * still there.
1288: */
1.1 deraadt 1289:
1.49 markus 1290: void
1.69 markus 1291: channel_input_data(int type, int plen, void *ctxt)
1.1 deraadt 1292: {
1.37 markus 1293: int id;
1.25 markus 1294: char *data;
1.77 markus 1295: u_int data_len;
1.41 markus 1296: Channel *c;
1.25 markus 1297:
1298: /* Get the channel number and verify it. */
1.37 markus 1299: id = packet_get_int();
1.41 markus 1300: c = channel_lookup(id);
1301: if (c == NULL)
1.37 markus 1302: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 1303:
1304: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 1305: if (c->type != SSH_CHANNEL_OPEN &&
1306: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 1307: return;
1308:
1309: /* same for protocol 1.5 if output end is no longer open */
1.41 markus 1310: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
1.25 markus 1311: return;
1312:
1313: /* Get the data. */
1314: data = packet_get_string(&data_len);
1.48 markus 1315: packet_done();
1.41 markus 1316:
1.44 markus 1317: if (compat20){
1318: if (data_len > c->local_maxpacket) {
1319: log("channel %d: rcvd big packet %d, maxpack %d",
1320: c->self, data_len, c->local_maxpacket);
1321: }
1322: if (data_len > c->local_window) {
1323: log("channel %d: rcvd too much data %d, win %d",
1324: c->self, data_len, c->local_window);
1325: xfree(data);
1326: return;
1327: }
1328: c->local_window -= data_len;
1329: }else{
1330: packet_integrity_check(plen, 4 + 4 + data_len, type);
1331: }
1.41 markus 1332: buffer_append(&c->output, data, data_len);
1.25 markus 1333: xfree(data);
1.1 deraadt 1334: }
1.49 markus 1335: void
1.69 markus 1336: channel_input_extended_data(int type, int plen, void *ctxt)
1.44 markus 1337: {
1338: int id;
1339: int tcode;
1340: char *data;
1.77 markus 1341: u_int data_len;
1.44 markus 1342: Channel *c;
1343:
1344: /* Get the channel number and verify it. */
1345: id = packet_get_int();
1346: c = channel_lookup(id);
1347:
1348: if (c == NULL)
1349: packet_disconnect("Received extended_data for bad channel %d.", id);
1350: if (c->type != SSH_CHANNEL_OPEN) {
1351: log("channel %d: ext data for non open", id);
1352: return;
1353: }
1354: tcode = packet_get_int();
1355: if (c->efd == -1 ||
1356: c->extended_usage != CHAN_EXTENDED_WRITE ||
1357: tcode != SSH2_EXTENDED_DATA_STDERR) {
1358: log("channel %d: bad ext data", c->self);
1359: return;
1360: }
1361: data = packet_get_string(&data_len);
1.48 markus 1362: packet_done();
1.44 markus 1363: if (data_len > c->local_window) {
1364: log("channel %d: rcvd too much extended_data %d, win %d",
1365: c->self, data_len, c->local_window);
1366: xfree(data);
1367: return;
1368: }
1.70 markus 1369: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 1370: c->local_window -= data_len;
1371: buffer_append(&c->extended, data, data_len);
1372: xfree(data);
1373: }
1374:
1.1 deraadt 1375:
1.27 markus 1376: /*
1377: * Returns true if no channel has too much buffered data, and false if one or
1378: * more channel is overfull.
1379: */
1.1 deraadt 1380:
1.49 markus 1381: int
1.25 markus 1382: channel_not_very_much_buffered_data()
1.1 deraadt 1383: {
1.77 markus 1384: u_int i;
1.41 markus 1385: Channel *c;
1.25 markus 1386:
1387: for (i = 0; i < channels_alloc; i++) {
1.41 markus 1388: c = &channels[i];
1389: if (c->type == SSH_CHANNEL_OPEN) {
1.44 markus 1390: if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
1.41 markus 1391: debug("channel %d: big input buffer %d",
1392: c->self, buffer_len(&c->input));
1.25 markus 1393: return 0;
1.41 markus 1394: }
1395: if (buffer_len(&c->output) > packet_get_maxsize()) {
1396: debug("channel %d: big output buffer %d",
1397: c->self, buffer_len(&c->output));
1.25 markus 1398: return 0;
1.41 markus 1399: }
1.25 markus 1400: }
1.1 deraadt 1401: }
1.25 markus 1402: return 1;
1.1 deraadt 1403: }
1404:
1.49 markus 1405: void
1.69 markus 1406: channel_input_ieof(int type, int plen, void *ctxt)
1.41 markus 1407: {
1408: int id;
1409: Channel *c;
1410:
1411: packet_integrity_check(plen, 4, type);
1412:
1413: id = packet_get_int();
1414: c = channel_lookup(id);
1415: if (c == NULL)
1416: packet_disconnect("Received ieof for nonexistent channel %d.", id);
1417: chan_rcvd_ieof(c);
1418: }
1.1 deraadt 1419:
1.49 markus 1420: void
1.69 markus 1421: channel_input_close(int type, int plen, void *ctxt)
1.1 deraadt 1422: {
1.41 markus 1423: int id;
1424: Channel *c;
1.1 deraadt 1425:
1.41 markus 1426: packet_integrity_check(plen, 4, type);
1427:
1428: id = packet_get_int();
1429: c = channel_lookup(id);
1430: if (c == NULL)
1431: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 1432:
1433: /*
1434: * Send a confirmation that we have closed the channel and no more
1435: * data is coming for it.
1436: */
1.25 markus 1437: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 1438: packet_put_int(c->remote_id);
1.25 markus 1439: packet_send();
1440:
1.27 markus 1441: /*
1442: * If the channel is in closed state, we have sent a close request,
1443: * and the other side will eventually respond with a confirmation.
1444: * Thus, we cannot free the channel here, because then there would be
1445: * no-one to receive the confirmation. The channel gets freed when
1446: * the confirmation arrives.
1447: */
1.41 markus 1448: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 1449: /*
1450: * Not a closed channel - mark it as draining, which will
1451: * cause it to be freed later.
1452: */
1.41 markus 1453: buffer_consume(&c->input, buffer_len(&c->input));
1454: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 1455: }
1.1 deraadt 1456: }
1457:
1.41 markus 1458: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.49 markus 1459: void
1.69 markus 1460: channel_input_oclose(int type, int plen, void *ctxt)
1.41 markus 1461: {
1462: int id = packet_get_int();
1463: Channel *c = channel_lookup(id);
1464: packet_integrity_check(plen, 4, type);
1465: if (c == NULL)
1466: packet_disconnect("Received oclose for nonexistent channel %d.", id);
1467: chan_rcvd_oclose(c);
1468: }
1.1 deraadt 1469:
1.49 markus 1470: void
1.69 markus 1471: channel_input_close_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1472: {
1.41 markus 1473: int id = packet_get_int();
1474: Channel *c = channel_lookup(id);
1.1 deraadt 1475:
1.48 markus 1476: packet_done();
1.41 markus 1477: if (c == NULL)
1478: packet_disconnect("Received close confirmation for "
1479: "out-of-range channel %d.", id);
1480: if (c->type != SSH_CHANNEL_CLOSED)
1481: packet_disconnect("Received close confirmation for "
1482: "non-closed channel %d (type %d).", id, c->type);
1483: channel_free(c->self);
1.1 deraadt 1484: }
1485:
1.49 markus 1486: void
1.69 markus 1487: channel_input_open_confirmation(int type, int plen, void *ctxt)
1.1 deraadt 1488: {
1.41 markus 1489: int id, remote_id;
1490: Channel *c;
1.1 deraadt 1491:
1.44 markus 1492: if (!compat20)
1493: packet_integrity_check(plen, 4 + 4, type);
1.25 markus 1494:
1.41 markus 1495: id = packet_get_int();
1496: c = channel_lookup(id);
1.25 markus 1497:
1.41 markus 1498: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1499: packet_disconnect("Received open confirmation for "
1500: "non-opening channel %d.", id);
1501: remote_id = packet_get_int();
1.27 markus 1502: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 1503: c->remote_id = remote_id;
1504: c->type = SSH_CHANNEL_OPEN;
1.44 markus 1505:
1506: if (compat20) {
1507: c->remote_window = packet_get_int();
1508: c->remote_maxpacket = packet_get_int();
1.48 markus 1509: packet_done();
1.44 markus 1510: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1511: debug2("callback start");
1.44 markus 1512: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1513: debug2("callback done");
1.44 markus 1514: }
1515: debug("channel %d: open confirm rwindow %d rmax %d", c->self,
1516: c->remote_window, c->remote_maxpacket);
1517: }
1.1 deraadt 1518: }
1519:
1.49 markus 1520: void
1.69 markus 1521: channel_input_open_failure(int type, int plen, void *ctxt)
1.1 deraadt 1522: {
1.86 markus 1523: int id, reason;
1524: char *msg = NULL, *lang = NULL;
1.41 markus 1525: Channel *c;
1526:
1.44 markus 1527: if (!compat20)
1528: packet_integrity_check(plen, 4, type);
1.41 markus 1529:
1530: id = packet_get_int();
1531: c = channel_lookup(id);
1.25 markus 1532:
1.41 markus 1533: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
1534: packet_disconnect("Received open failure for "
1535: "non-opening channel %d.", id);
1.44 markus 1536: if (compat20) {
1.86 markus 1537: reason = packet_get_int();
1538: if (packet_remaining() > 0) {
1539: msg = packet_get_string(NULL);
1540: lang = packet_get_string(NULL);
1541: }
1.48 markus 1542: packet_done();
1.86 markus 1543: log("channel_open_failure: %d: reason %d %s", id,
1544: reason, msg ? msg : "<no additional info>");
1545: if (msg != NULL)
1546: xfree(msg);
1547: if (lang != NULL)
1548: xfree(lang);
1.44 markus 1549: }
1.25 markus 1550: /* Free the channel. This will also close the socket. */
1.41 markus 1551: channel_free(id);
1.1 deraadt 1552: }
1553:
1.44 markus 1554: void
1.69 markus 1555: channel_input_channel_request(int type, int plen, void *ctxt)
1.44 markus 1556: {
1557: int id;
1558: Channel *c;
1559:
1560: id = packet_get_int();
1561: c = channel_lookup(id);
1562:
1563: if (c == NULL ||
1564: (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
1565: packet_disconnect("Received request for "
1566: "non-open channel %d.", id);
1567: if (c->cb_fn != NULL && c->cb_event == type) {
1.70 markus 1568: debug2("callback start");
1.44 markus 1569: c->cb_fn(c->self, c->cb_arg);
1.70 markus 1570: debug2("callback done");
1.44 markus 1571: } else {
1572: char *service = packet_get_string(NULL);
1.94 markus 1573: debug("channel %d: rcvd request for %s", c->self, service);
1.70 markus 1574: debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
1.44 markus 1575: xfree(service);
1576: }
1577: }
1578:
1.49 markus 1579: void
1.69 markus 1580: channel_input_window_adjust(int type, int plen, void *ctxt)
1.44 markus 1581: {
1582: Channel *c;
1583: int id, adjust;
1584:
1585: if (!compat20)
1586: return;
1587:
1588: /* Get the channel number and verify it. */
1589: id = packet_get_int();
1590: c = channel_lookup(id);
1591:
1592: if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
1593: log("Received window adjust for "
1594: "non-open channel %d.", id);
1595: return;
1596: }
1597: adjust = packet_get_int();
1.48 markus 1598: packet_done();
1.70 markus 1599: debug2("channel %d: rcvd adjust %d", id, adjust);
1.44 markus 1600: c->remote_window += adjust;
1601: }
1602:
1.27 markus 1603: /*
1604: * Stops listening for channels, and removes any unix domain sockets that we
1605: * might have.
1606: */
1.1 deraadt 1607:
1.49 markus 1608: void
1.25 markus 1609: channel_stop_listening()
1.1 deraadt 1610: {
1.25 markus 1611: int i;
1612: for (i = 0; i < channels_alloc; i++) {
1613: switch (channels[i].type) {
1614: case SSH_CHANNEL_AUTH_SOCKET:
1615: close(channels[i].sock);
1.76 markus 1616: unlink(channels[i].path);
1.25 markus 1617: channel_free(i);
1618: break;
1619: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1620: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1621: case SSH_CHANNEL_X11_LISTENER:
1622: close(channels[i].sock);
1623: channel_free(i);
1624: break;
1625: default:
1626: break;
1627: }
1.1 deraadt 1628: }
1629: }
1630:
1.27 markus 1631: /*
1.52 markus 1632: * Closes the sockets/fds of all channels. This is used to close extra file
1.27 markus 1633: * descriptors after a fork.
1634: */
1.1 deraadt 1635:
1.49 markus 1636: void
1.25 markus 1637: channel_close_all()
1.1 deraadt 1638: {
1.25 markus 1639: int i;
1.52 markus 1640: for (i = 0; i < channels_alloc; i++)
1.25 markus 1641: if (channels[i].type != SSH_CHANNEL_FREE)
1.52 markus 1642: channel_close_fds(&channels[i]);
1.1 deraadt 1643: }
1644:
1645: /* Returns true if any channel is still open. */
1646:
1.49 markus 1647: int
1.25 markus 1648: channel_still_open()
1.1 deraadt 1649: {
1.77 markus 1650: u_int i;
1.25 markus 1651: for (i = 0; i < channels_alloc; i++)
1652: switch (channels[i].type) {
1653: case SSH_CHANNEL_FREE:
1654: case SSH_CHANNEL_X11_LISTENER:
1655: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1656: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1657: case SSH_CHANNEL_CLOSED:
1658: case SSH_CHANNEL_AUTH_SOCKET:
1.103 markus 1659: case SSH_CHANNEL_DYNAMIC:
1.75 markus 1660: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.25 markus 1661: continue;
1.44 markus 1662: case SSH_CHANNEL_LARVAL:
1663: if (!compat20)
1664: fatal("cannot happen: SSH_CHANNEL_LARVAL");
1665: continue;
1.25 markus 1666: case SSH_CHANNEL_OPENING:
1667: case SSH_CHANNEL_OPEN:
1668: case SSH_CHANNEL_X11_OPEN:
1669: return 1;
1670: case SSH_CHANNEL_INPUT_DRAINING:
1671: case SSH_CHANNEL_OUTPUT_DRAINING:
1672: if (!compat13)
1673: fatal("cannot happen: OUT_DRAIN");
1674: return 1;
1675: default:
1676: fatal("channel_still_open: bad channel type %d", channels[i].type);
1677: /* NOTREACHED */
1678: }
1679: return 0;
1.1 deraadt 1680: }
1.107 beck 1681:
1682: /* Returns the id of an open channel suitable for keepaliving */
1683:
1684: int
1685: channel_find_open()
1686: {
1687: u_int i;
1688: for (i = 0; i < channels_alloc; i++)
1689: switch (channels[i].type) {
1690: case SSH_CHANNEL_CLOSED:
1691: case SSH_CHANNEL_DYNAMIC:
1692: case SSH_CHANNEL_FREE:
1693: case SSH_CHANNEL_X11_LISTENER:
1694: case SSH_CHANNEL_PORT_LISTENER:
1695: case SSH_CHANNEL_RPORT_LISTENER:
1696: case SSH_CHANNEL_OPENING:
1.108 markus 1697: continue;
1698: case SSH_CHANNEL_LARVAL:
1699: case SSH_CHANNEL_AUTH_SOCKET:
1700: case SSH_CHANNEL_CONNECTING: /* XXX ??? */
1.107 beck 1701: case SSH_CHANNEL_OPEN:
1702: case SSH_CHANNEL_X11_OPEN:
1703: return i;
1704: case SSH_CHANNEL_INPUT_DRAINING:
1705: case SSH_CHANNEL_OUTPUT_DRAINING:
1706: if (!compat13)
1707: fatal("cannot happen: OUT_DRAIN");
1708: return i;
1709: default:
1710: fatal("channel_find_open: bad channel type %d", channels[i].type);
1711: /* NOTREACHED */
1712: }
1713: return -1;
1714: }
1715:
1.1 deraadt 1716:
1.27 markus 1717: /*
1718: * Returns a message describing the currently open forwarded connections,
1719: * suitable for sending to the client. The message contains crlf pairs for
1720: * newlines.
1721: */
1.1 deraadt 1722:
1.25 markus 1723: char *
1724: channel_open_message()
1.1 deraadt 1725: {
1.25 markus 1726: Buffer buffer;
1727: int i;
1728: char buf[512], *cp;
1729:
1730: buffer_init(&buffer);
1731: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
1.1 deraadt 1732: buffer_append(&buffer, buf, strlen(buf));
1.25 markus 1733: for (i = 0; i < channels_alloc; i++) {
1734: Channel *c = &channels[i];
1735: switch (c->type) {
1736: case SSH_CHANNEL_FREE:
1737: case SSH_CHANNEL_X11_LISTENER:
1738: case SSH_CHANNEL_PORT_LISTENER:
1.73 markus 1739: case SSH_CHANNEL_RPORT_LISTENER:
1.25 markus 1740: case SSH_CHANNEL_CLOSED:
1741: case SSH_CHANNEL_AUTH_SOCKET:
1742: continue;
1.44 markus 1743: case SSH_CHANNEL_LARVAL:
1.25 markus 1744: case SSH_CHANNEL_OPENING:
1.75 markus 1745: case SSH_CHANNEL_CONNECTING:
1.103 markus 1746: case SSH_CHANNEL_DYNAMIC:
1.25 markus 1747: case SSH_CHANNEL_OPEN:
1748: case SSH_CHANNEL_X11_OPEN:
1749: case SSH_CHANNEL_INPUT_DRAINING:
1750: case SSH_CHANNEL_OUTPUT_DRAINING:
1.41 markus 1751: snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
1.37 markus 1752: c->self, c->remote_name,
1753: c->type, c->remote_id,
1754: c->istate, buffer_len(&c->input),
1.41 markus 1755: c->ostate, buffer_len(&c->output),
1756: c->rfd, c->wfd);
1.25 markus 1757: buffer_append(&buffer, buf, strlen(buf));
1758: continue;
1759: default:
1.41 markus 1760: fatal("channel_open_message: bad channel type %d", c->type);
1.25 markus 1761: /* NOTREACHED */
1762: }
1763: }
1764: buffer_append(&buffer, "\0", 1);
1765: cp = xstrdup(buffer_ptr(&buffer));
1766: buffer_free(&buffer);
1767: return cp;
1.1 deraadt 1768: }
1769:
1.27 markus 1770: /*
1771: * Initiate forwarding of connections to local port "port" through the secure
1772: * channel to host:port from remote side.
1773: */
1.87 markus 1774: int
1.73 markus 1775: channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
1776: u_short port_to_connect, int gateway_ports)
1777: {
1.87 markus 1778: return channel_request_forwarding(
1.73 markus 1779: NULL, listen_port,
1780: host_to_connect, port_to_connect,
1781: gateway_ports, /*remote_fwd*/ 0);
1782: }
1.1 deraadt 1783:
1.73 markus 1784: /*
1785: * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
1786: * (SSH_CHANNEL_RPORT_LISTENER).
1787: */
1.87 markus 1788: int
1.73 markus 1789: channel_request_forwarding(
1790: const char *listen_address, u_short listen_port,
1791: const char *host_to_connect, u_short port_to_connect,
1792: int gateway_ports, int remote_fwd)
1.25 markus 1793: {
1.73 markus 1794: int success, ch, sock, on = 1, ctype;
1.35 markus 1795: struct addrinfo hints, *ai, *aitop;
1796: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.73 markus 1797: const char *host;
1.28 markus 1798: struct linger linger;
1.25 markus 1799:
1.87 markus 1800: success = 0;
1801:
1.73 markus 1802: if (remote_fwd) {
1803: host = listen_address;
1.89 stevesk 1804: ctype = SSH_CHANNEL_RPORT_LISTENER;
1.73 markus 1805: } else {
1806: host = host_to_connect;
1807: ctype =SSH_CHANNEL_PORT_LISTENER;
1808: }
1809:
1.87 markus 1810: if (strlen(host) > sizeof(channels[0].path) - 1) {
1811: error("Forward host name too long.");
1812: return success;
1813: }
1.25 markus 1814:
1.73 markus 1815: /* XXX listen_address is currently ignored */
1.28 markus 1816: /*
1.35 markus 1817: * getaddrinfo returns a loopback address if the hostname is
1818: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 1819: */
1.35 markus 1820: memset(&hints, 0, sizeof(hints));
1821: hints.ai_family = IPv4or6;
1822: hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
1823: hints.ai_socktype = SOCK_STREAM;
1.73 markus 1824: snprintf(strport, sizeof strport, "%d", listen_port);
1.35 markus 1825: if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
1826: packet_disconnect("getaddrinfo: fatal error");
1827:
1828: for (ai = aitop; ai; ai = ai->ai_next) {
1829: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1830: continue;
1831: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1832: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.73 markus 1833: error("channel_request_forwarding: getnameinfo failed");
1.35 markus 1834: continue;
1835: }
1836: /* Create a port to listen for the host. */
1837: sock = socket(ai->ai_family, SOCK_STREAM, 0);
1838: if (sock < 0) {
1839: /* this is no error since kernel may not support ipv6 */
1840: verbose("socket: %.100s", strerror(errno));
1841: continue;
1842: }
1843: /*
1844: * Set socket options. We would like the socket to disappear
1845: * as soon as it has been closed for whatever reason.
1846: */
1847: setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
1848: linger.l_onoff = 1;
1849: linger.l_linger = 5;
1850: setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));
1851: debug("Local forwarding listening on %s port %s.", ntop, strport);
1852:
1853: /* Bind the socket to the address. */
1854: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1855: /* address can be in use ipv6 address is already bound */
1856: verbose("bind: %.100s", strerror(errno));
1857: close(sock);
1858: continue;
1859: }
1860: /* Start listening for connections on the socket. */
1861: if (listen(sock, 5) < 0) {
1862: error("listen: %.100s", strerror(errno));
1863: close(sock);
1864: continue;
1865: }
1866: /* Allocate a channel number for the socket. */
1.73 markus 1867: ch = channel_new("port listener", ctype, sock, sock, -1,
1.51 markus 1868: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.71 markus 1869: 0, xstrdup("port listener"), 1);
1.35 markus 1870: strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
1.73 markus 1871: channels[ch].host_port = port_to_connect;
1872: channels[ch].listening_port = listen_port;
1.35 markus 1873: success = 1;
1874: }
1875: if (success == 0)
1.87 markus 1876: error("channel_request_forwarding: cannot listen to port: %d",
1877: listen_port);
1.35 markus 1878: freeaddrinfo(aitop);
1.87 markus 1879: return success;
1.25 markus 1880: }
1.1 deraadt 1881:
1.27 markus 1882: /*
1883: * Initiate forwarding of connections to port "port" on remote host through
1884: * the secure channel to host:port from local side.
1885: */
1.1 deraadt 1886:
1.49 markus 1887: void
1.73 markus 1888: channel_request_remote_forwarding(u_short listen_port,
1889: const char *host_to_connect, u_short port_to_connect)
1.25 markus 1890: {
1.73 markus 1891: int payload_len, type, success = 0;
1892:
1.25 markus 1893: /* Record locally that connection to this host/port is permitted. */
1894: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1895: fatal("channel_request_remote_forwarding: too many forwards");
1896:
1897: /* Send the forward request to the remote side. */
1.44 markus 1898: if (compat20) {
1899: const char *address_to_bind = "0.0.0.0";
1900: packet_start(SSH2_MSG_GLOBAL_REQUEST);
1901: packet_put_cstring("tcpip-forward");
1902: packet_put_char(0); /* boolean: want reply */
1903: packet_put_cstring(address_to_bind);
1904: packet_put_int(listen_port);
1.73 markus 1905: packet_send();
1906: packet_write_wait();
1907: /* Assume that server accepts the request */
1908: success = 1;
1.44 markus 1909: } else {
1910: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 1911: packet_put_int(listen_port);
1912: packet_put_cstring(host_to_connect);
1.44 markus 1913: packet_put_int(port_to_connect);
1914: packet_send();
1915: packet_write_wait();
1.73 markus 1916:
1917: /* Wait for response from the remote side. */
1918: type = packet_read(&payload_len);
1919: switch (type) {
1920: case SSH_SMSG_SUCCESS:
1921: success = 1;
1922: break;
1923: case SSH_SMSG_FAILURE:
1924: log("Warning: Server denied remote port forwarding.");
1925: break;
1926: default:
1927: /* Unknown packet */
1928: packet_disconnect("Protocol error for port forward request:"
1929: "received packet type %d.", type);
1930: }
1931: }
1932: if (success) {
1933: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
1934: permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
1935: permitted_opens[num_permitted_opens].listen_port = listen_port;
1936: num_permitted_opens++;
1.44 markus 1937: }
1.1 deraadt 1938: }
1939:
1.27 markus 1940: /*
1941: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
1942: * listening for the port, and sends back a success reply (or disconnect
1943: * message if there was an error). This never returns if there was an error.
1944: */
1.1 deraadt 1945:
1.49 markus 1946: void
1.56 markus 1947: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 1948: {
1.31 markus 1949: u_short port, host_port;
1.25 markus 1950: char *hostname;
1.1 deraadt 1951:
1.25 markus 1952: /* Get arguments from the packet. */
1953: port = packet_get_int();
1954: hostname = packet_get_string(NULL);
1955: host_port = packet_get_int();
1956:
1.27 markus 1957: /*
1958: * Check that an unprivileged user is not trying to forward a
1959: * privileged port.
1960: */
1.25 markus 1961: if (port < IPPORT_RESERVED && !is_root)
1962: packet_disconnect("Requested forwarding of port %d but user is not root.",
1963: port);
1.73 markus 1964: /* Initiate forwarding */
1.56 markus 1965: channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
1.25 markus 1966:
1967: /* Free the argument string. */
1968: xfree(hostname);
1.1 deraadt 1969: }
1970:
1.99 markus 1971: /*
1972: * Permits opening to any host/port if permitted_opens[] is empty. This is
1973: * usually called by the server, because the user could connect to any port
1974: * anyway, and the server has no way to know but to trust the client anyway.
1975: */
1976: void
1977: channel_permit_all_opens()
1978: {
1979: if (num_permitted_opens == 0)
1980: all_opens_permitted = 1;
1981: }
1982:
1.101 markus 1983: void
1.99 markus 1984: channel_add_permitted_opens(char *host, int port)
1985: {
1986: if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
1987: fatal("channel_request_remote_forwarding: too many forwards");
1988: debug("allow port forwarding to host %s port %d", host, port);
1989:
1990: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
1991: permitted_opens[num_permitted_opens].port_to_connect = port;
1992: num_permitted_opens++;
1993:
1994: all_opens_permitted = 0;
1995: }
1996:
1.101 markus 1997: void
1.99 markus 1998: channel_clear_permitted_opens(void)
1999: {
2000: int i;
2001:
2002: for (i = 0; i < num_permitted_opens; i++)
2003: xfree(permitted_opens[i].host_to_connect);
2004: num_permitted_opens = 0;
2005:
2006: }
2007:
2008:
2009: /* return socket to remote host, port */
1.41 markus 2010: int
1.99 markus 2011: connect_to(const char *host, u_short port)
1.41 markus 2012: {
2013: struct addrinfo hints, *ai, *aitop;
2014: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2015: int gaierr;
2016: int sock = -1;
2017:
2018: memset(&hints, 0, sizeof(hints));
2019: hints.ai_family = IPv4or6;
2020: hints.ai_socktype = SOCK_STREAM;
1.99 markus 2021: snprintf(strport, sizeof strport, "%d", port);
1.41 markus 2022: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
1.99 markus 2023: error("connect_to %.100s: unknown host (%s)", host,
2024: gai_strerror(gaierr));
1.41 markus 2025: return -1;
2026: }
2027: for (ai = aitop; ai; ai = ai->ai_next) {
2028: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2029: continue;
2030: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2031: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.99 markus 2032: error("connect_to: getnameinfo failed");
1.41 markus 2033: continue;
2034: }
2035: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2036: if (sock < 0) {
2037: error("socket: %.100s", strerror(errno));
2038: continue;
2039: }
1.80 markus 2040: if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
1.75 markus 2041: fatal("connect_to: F_SETFL: %s", strerror(errno));
2042: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2043: errno != EINPROGRESS) {
1.99 markus 2044: error("connect_to %.100s port %s: %.100s", ntop, strport,
1.41 markus 2045: strerror(errno));
2046: close(sock);
1.89 stevesk 2047: continue; /* fail -- try next */
1.41 markus 2048: }
2049: break; /* success */
2050:
2051: }
2052: freeaddrinfo(aitop);
2053: if (!ai) {
1.99 markus 2054: error("connect_to %.100s port %d: failed.", host, port);
1.41 markus 2055: return -1;
2056: }
2057: /* success */
2058: return sock;
2059: }
1.99 markus 2060:
1.73 markus 2061: int
2062: channel_connect_by_listen_adress(u_short listen_port)
2063: {
2064: int i;
1.99 markus 2065:
1.73 markus 2066: for (i = 0; i < num_permitted_opens; i++)
2067: if (permitted_opens[i].listen_port == listen_port)
1.99 markus 2068: return connect_to(
1.73 markus 2069: permitted_opens[i].host_to_connect,
2070: permitted_opens[i].port_to_connect);
1.74 markus 2071: error("WARNING: Server requests forwarding for unknown listen_port %d",
2072: listen_port);
1.73 markus 2073: return -1;
2074: }
2075:
1.99 markus 2076: /* Check if connecting to that port is permitted and connect. */
2077: int
2078: channel_connect_to(const char *host, u_short port)
2079: {
2080: int i, permit;
2081:
2082: permit = all_opens_permitted;
2083: if (!permit) {
2084: for (i = 0; i < num_permitted_opens; i++)
2085: if (permitted_opens[i].port_to_connect == port &&
2086: strcmp(permitted_opens[i].host_to_connect, host) == 0)
2087: permit = 1;
2088:
2089: }
2090: if (!permit) {
2091: log("Received request to connect to host %.100s port %d, "
2092: "but the request was denied.", host, port);
2093: return -1;
2094: }
2095: return connect_to(host, port);
2096: }
2097:
1.27 markus 2098: /*
2099: * This is called after receiving PORT_OPEN message. This attempts to
2100: * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
2101: * or CHANNEL_OPEN_FAILURE.
2102: */
1.1 deraadt 2103:
1.49 markus 2104: void
1.69 markus 2105: channel_input_port_open(int type, int plen, void *ctxt)
1.1 deraadt 2106: {
1.31 markus 2107: u_short host_port;
1.25 markus 2108: char *host, *originator_string;
1.99 markus 2109: int remote_channel, sock = -1, newch;
1.25 markus 2110:
2111: remote_channel = packet_get_int();
1.99 markus 2112: host = packet_get_string(NULL);
1.25 markus 2113: host_port = packet_get_int();
2114:
1.29 markus 2115: if (have_hostname_in_open) {
1.99 markus 2116: originator_string = packet_get_string(NULL);
1.29 markus 2117: } else {
1.25 markus 2118: originator_string = xstrdup("unknown (remote did not supply name)");
1.29 markus 2119: }
1.99 markus 2120: packet_done();
2121: sock = channel_connect_to(host, host_port);
2122: if (sock != -1) {
1.75 markus 2123: newch = channel_allocate(SSH_CHANNEL_CONNECTING,
2124: sock, originator_string);
1.41 markus 2125: channels[newch].remote_id = remote_channel;
2126:
1.99 markus 2127: /*XXX delay answer? */
1.41 markus 2128: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2129: packet_put_int(remote_channel);
2130: packet_put_int(newch);
2131: packet_send();
2132: } else {
2133: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2134: packet_put_int(remote_channel);
2135: packet_send();
1.25 markus 2136: }
2137: xfree(host);
1.1 deraadt 2138: }
2139:
1.27 markus 2140: /*
2141: * Creates an internet domain socket for listening for X11 connections.
2142: * Returns a suitable value for the DISPLAY variable, or NULL if an error
2143: * occurs.
2144: */
1.1 deraadt 2145:
1.35 markus 2146: #define NUM_SOCKS 10
2147:
1.25 markus 2148: char *
1.33 markus 2149: x11_create_display_inet(int screen_number, int x11_display_offset)
1.1 deraadt 2150: {
1.31 markus 2151: int display_number, sock;
2152: u_short port;
1.35 markus 2153: struct addrinfo hints, *ai, *aitop;
2154: char strport[NI_MAXSERV];
2155: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
2156: char display[512];
1.25 markus 2157: char hostname[MAXHOSTNAMELEN];
2158:
1.33 markus 2159: for (display_number = x11_display_offset;
1.25 markus 2160: display_number < MAX_DISPLAYS;
2161: display_number++) {
2162: port = 6000 + display_number;
1.35 markus 2163: memset(&hints, 0, sizeof(hints));
2164: hints.ai_family = IPv4or6;
1.36 markus 2165: hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */
1.35 markus 2166: hints.ai_socktype = SOCK_STREAM;
2167: snprintf(strport, sizeof strport, "%d", port);
2168: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
2169: error("getaddrinfo: %.100s", gai_strerror(gaierr));
1.25 markus 2170: return NULL;
2171: }
1.35 markus 2172: for (ai = aitop; ai; ai = ai->ai_next) {
2173: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2174: continue;
2175: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2176: if (sock < 0) {
2177: error("socket: %.100s", strerror(errno));
2178: return NULL;
2179: }
2180: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2181: debug("bind port %d: %.100s", port, strerror(errno));
2182: shutdown(sock, SHUT_RDWR);
2183: close(sock);
2184: for (n = 0; n < num_socks; n++) {
2185: shutdown(socks[n], SHUT_RDWR);
2186: close(socks[n]);
2187: }
2188: num_socks = 0;
2189: break;
2190: }
2191: socks[num_socks++] = sock;
2192: if (num_socks == NUM_SOCKS)
2193: break;
1.25 markus 2194: }
1.83 stevesk 2195: freeaddrinfo(aitop);
1.35 markus 2196: if (num_socks > 0)
2197: break;
1.25 markus 2198: }
2199: if (display_number >= MAX_DISPLAYS) {
2200: error("Failed to allocate internet-domain X11 display socket.");
2201: return NULL;
2202: }
2203: /* Start listening for connections on the socket. */
1.35 markus 2204: for (n = 0; n < num_socks; n++) {
2205: sock = socks[n];
2206: if (listen(sock, 5) < 0) {
2207: error("listen: %.100s", strerror(errno));
2208: shutdown(sock, SHUT_RDWR);
2209: close(sock);
2210: return NULL;
2211: }
1.25 markus 2212: }
1.35 markus 2213:
1.25 markus 2214: /* Set up a suitable value for the DISPLAY variable. */
2215: if (gethostname(hostname, sizeof(hostname)) < 0)
2216: fatal("gethostname: %.100s", strerror(errno));
1.35 markus 2217: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1.25 markus 2218: display_number, screen_number);
2219:
1.35 markus 2220: /* Allocate a channel for each socket. */
2221: for (n = 0; n < num_socks; n++) {
2222: sock = socks[n];
1.51 markus 2223: (void) channel_new("x11 listener",
2224: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
2225: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.71 markus 2226: 0, xstrdup("X11 inet listener"), 1);
1.35 markus 2227: }
1.1 deraadt 2228:
1.25 markus 2229: /* Return a suitable value for the DISPLAY environment variable. */
1.35 markus 2230: return xstrdup(display);
1.1 deraadt 2231: }
2232:
2233: #ifndef X_UNIX_PATH
2234: #define X_UNIX_PATH "/tmp/.X11-unix/X"
2235: #endif
2236:
2237: static
2238: int
1.77 markus 2239: connect_local_xsocket(u_int dnr)
1.1 deraadt 2240: {
1.25 markus 2241: static const char *const x_sockets[] = {
2242: X_UNIX_PATH "%u",
2243: "/var/X/.X11-unix/X" "%u",
2244: "/usr/spool/sockets/X11/" "%u",
2245: NULL
2246: };
2247: int sock;
2248: struct sockaddr_un addr;
2249: const char *const * path;
2250:
2251: for (path = x_sockets; *path; ++path) {
2252: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2253: if (sock < 0)
2254: error("socket: %.100s", strerror(errno));
2255: memset(&addr, 0, sizeof(addr));
2256: addr.sun_family = AF_UNIX;
2257: snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr);
2258: if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
2259: return sock;
2260: close(sock);
2261: }
2262: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
2263: return -1;
1.1 deraadt 2264: }
2265:
1.51 markus 2266: int
2267: x11_connect_display(void)
1.1 deraadt 2268: {
1.51 markus 2269: int display_number, sock = 0;
1.25 markus 2270: const char *display;
1.51 markus 2271: char buf[1024], *cp;
1.35 markus 2272: struct addrinfo hints, *ai, *aitop;
2273: char strport[NI_MAXSERV];
2274: int gaierr;
1.25 markus 2275:
2276: /* Try to open a socket for the local X server. */
2277: display = getenv("DISPLAY");
2278: if (!display) {
2279: error("DISPLAY not set.");
1.51 markus 2280: return -1;
1.25 markus 2281: }
1.27 markus 2282: /*
2283: * Now we decode the value of the DISPLAY variable and make a
2284: * connection to the real X server.
2285: */
2286:
2287: /*
2288: * Check if it is a unix domain socket. Unix domain displays are in
2289: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
2290: */
1.25 markus 2291: if (strncmp(display, "unix:", 5) == 0 ||
2292: display[0] == ':') {
2293: /* Connect to the unix domain socket. */
2294: if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
2295: error("Could not parse display number from DISPLAY: %.100s",
2296: display);
1.51 markus 2297: return -1;
1.25 markus 2298: }
2299: /* Create a socket. */
2300: sock = connect_local_xsocket(display_number);
2301: if (sock < 0)
1.51 markus 2302: return -1;
1.25 markus 2303:
2304: /* OK, we now have a connection to the display. */
1.51 markus 2305: return sock;
1.25 markus 2306: }
1.27 markus 2307: /*
2308: * Connect to an inet socket. The DISPLAY value is supposedly
2309: * hostname:d[.s], where hostname may also be numeric IP address.
2310: */
1.25 markus 2311: strncpy(buf, display, sizeof(buf));
2312: buf[sizeof(buf) - 1] = 0;
2313: cp = strchr(buf, ':');
2314: if (!cp) {
2315: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 2316: return -1;
1.25 markus 2317: }
2318: *cp = 0;
1.27 markus 2319: /* buf now contains the host name. But first we parse the display number. */
1.25 markus 2320: if (sscanf(cp + 1, "%d", &display_number) != 1) {
2321: error("Could not parse display number from DISPLAY: %.100s",
2322: display);
1.51 markus 2323: return -1;
1.25 markus 2324: }
1.35 markus 2325:
2326: /* Look up the host address */
2327: memset(&hints, 0, sizeof(hints));
2328: hints.ai_family = IPv4or6;
2329: hints.ai_socktype = SOCK_STREAM;
2330: snprintf(strport, sizeof strport, "%d", 6000 + display_number);
2331: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
2332: error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
1.51 markus 2333: return -1;
1.25 markus 2334: }
1.35 markus 2335: for (ai = aitop; ai; ai = ai->ai_next) {
2336: /* Create a socket. */
2337: sock = socket(ai->ai_family, SOCK_STREAM, 0);
2338: if (sock < 0) {
2339: debug("socket: %.100s", strerror(errno));
1.41 markus 2340: continue;
2341: }
2342: /* Connect it to the display. */
2343: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2344: debug("connect %.100s port %d: %.100s", buf,
2345: 6000 + display_number, strerror(errno));
2346: close(sock);
2347: continue;
2348: }
2349: /* Success */
2350: break;
1.35 markus 2351: }
2352: freeaddrinfo(aitop);
2353: if (!ai) {
1.49 markus 2354: error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
1.35 markus 2355: strerror(errno));
1.51 markus 2356: return -1;
1.25 markus 2357: }
1.51 markus 2358: return sock;
2359: }
2360:
2361: /*
2362: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
2363: * the remote channel number. We should do whatever we want, and respond
2364: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
2365: */
2366:
2367: void
1.69 markus 2368: x11_input_open(int type, int plen, void *ctxt)
1.51 markus 2369: {
2370: int remote_channel, sock = 0, newch;
2371: char *remote_host;
1.77 markus 2372: u_int remote_len;
1.25 markus 2373:
1.51 markus 2374: /* Get remote channel number. */
2375: remote_channel = packet_get_int();
2376:
2377: /* Get remote originator name. */
2378: if (have_hostname_in_open) {
2379: remote_host = packet_get_string(&remote_len);
2380: remote_len += 4;
2381: } else {
2382: remote_host = xstrdup("unknown (remote did not supply name)");
2383: remote_len = 0;
2384: }
1.25 markus 2385:
1.51 markus 2386: debug("Received X11 open request.");
2387: packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
1.25 markus 2388:
1.51 markus 2389: /* Obtain a connection to the real X display. */
2390: sock = x11_connect_display();
2391: if (sock == -1) {
2392: /* Send refusal to the remote host. */
2393: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2394: packet_put_int(remote_channel);
2395: packet_send();
2396: } else {
2397: /* Allocate a channel for this connection. */
2398: newch = channel_allocate(
2399: (x11_saved_proto == NULL) ?
2400: SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN,
2401: sock, remote_host);
2402: channels[newch].remote_id = remote_channel;
1.25 markus 2403:
1.51 markus 2404: /* Send a confirmation to the remote host. */
2405: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2406: packet_put_int(remote_channel);
2407: packet_put_int(newch);
2408: packet_send();
2409: }
1.72 markus 2410: }
2411:
2412: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
2413: void
2414: deny_input_open(int type, int plen, void *ctxt)
2415: {
2416: int rchan = packet_get_int();
2417: switch(type){
2418: case SSH_SMSG_AGENT_OPEN:
2419: error("Warning: ssh server tried agent forwarding.");
2420: break;
2421: case SSH_SMSG_X11_OPEN:
2422: error("Warning: ssh server tried X11 forwarding.");
2423: break;
2424: default:
2425: error("deny_input_open: type %d plen %d", type, plen);
2426: break;
2427: }
2428: error("Warning: this is probably a break in attempt by a malicious server.");
2429: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2430: packet_put_int(rchan);
2431: packet_send();
1.1 deraadt 2432: }
2433:
1.27 markus 2434: /*
2435: * Requests forwarding of X11 connections, generates fake authentication
2436: * data, and enables authentication spoofing.
2437: */
1.1 deraadt 2438:
1.49 markus 2439: void
1.51 markus 2440: x11_request_forwarding_with_spoofing(int client_session_id,
2441: const char *proto, const char *data)
1.1 deraadt 2442: {
1.77 markus 2443: u_int data_len = (u_int) strlen(data) / 2;
1.90 markus 2444: u_int i, value, len;
1.25 markus 2445: char *new_data;
2446: int screen_number;
2447: const char *cp;
2448: u_int32_t rand = 0;
2449:
2450: cp = getenv("DISPLAY");
2451: if (cp)
2452: cp = strchr(cp, ':');
2453: if (cp)
2454: cp = strchr(cp, '.');
2455: if (cp)
2456: screen_number = atoi(cp + 1);
2457: else
2458: screen_number = 0;
2459:
2460: /* Save protocol name. */
2461: x11_saved_proto = xstrdup(proto);
2462:
1.27 markus 2463: /*
2464: * Extract real authentication data and generate fake data of the
2465: * same length.
2466: */
1.25 markus 2467: x11_saved_data = xmalloc(data_len);
2468: x11_fake_data = xmalloc(data_len);
2469: for (i = 0; i < data_len; i++) {
2470: if (sscanf(data + 2 * i, "%2x", &value) != 1)
2471: fatal("x11_request_forwarding: bad authentication data: %.100s", data);
2472: if (i % 4 == 0)
2473: rand = arc4random();
2474: x11_saved_data[i] = value;
2475: x11_fake_data[i] = rand & 0xff;
2476: rand >>= 8;
2477: }
2478: x11_saved_data_len = data_len;
2479: x11_fake_data_len = data_len;
2480:
2481: /* Convert the fake data into hex. */
1.90 markus 2482: len = 2 * data_len + 1;
2483: new_data = xmalloc(len);
1.25 markus 2484: for (i = 0; i < data_len; i++)
1.90 markus 2485: snprintf(new_data + 2 * i, len - 2 * i,
2486: "%02x", (u_char) x11_fake_data[i]);
1.25 markus 2487:
2488: /* Send the request packet. */
1.51 markus 2489: if (compat20) {
2490: channel_request_start(client_session_id, "x11-req", 0);
2491: packet_put_char(0); /* XXX bool single connection */
2492: } else {
2493: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
2494: }
2495: packet_put_cstring(proto);
2496: packet_put_cstring(new_data);
1.25 markus 2497: packet_put_int(screen_number);
2498: packet_send();
2499: packet_write_wait();
2500: xfree(new_data);
1.1 deraadt 2501: }
2502:
2503: /* Sends a message to the server to request authentication fd forwarding. */
2504:
1.49 markus 2505: void
1.25 markus 2506: auth_request_forwarding()
1.1 deraadt 2507: {
1.25 markus 2508: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
2509: packet_send();
2510: packet_write_wait();
1.1 deraadt 2511: }
2512:
1.27 markus 2513: /*
2514: * Returns the name of the forwarded authentication socket. Returns NULL if
2515: * there is no forwarded authentication socket. The returned value points to
2516: * a static buffer.
2517: */
1.1 deraadt 2518:
1.25 markus 2519: char *
2520: auth_get_socket_name()
1.1 deraadt 2521: {
1.25 markus 2522: return channel_forwarded_auth_socket_name;
1.1 deraadt 2523: }
2524:
1.12 markus 2525: /* removes the agent forwarding socket */
2526:
1.49 markus 2527: void
1.109.2.1 jason 2528: auth_sock_cleanup_proc(void *_pw)
1.25 markus 2529: {
1.109.2.1 jason 2530: struct passwd *pw = _pw;
2531:
2532: if (channel_forwarded_auth_socket_name) {
2533: temporarily_use_uid(pw);
2534: unlink(channel_forwarded_auth_socket_name);
2535: rmdir(channel_forwarded_auth_socket_dir);
2536: channel_forwarded_auth_socket_name = NULL;
2537: restore_uid();
2538: }
1.12 markus 2539: }
2540:
1.27 markus 2541: /*
1.59 markus 2542: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.27 markus 2543: * This starts forwarding authentication requests.
2544: */
1.1 deraadt 2545:
1.59 markus 2546: int
1.25 markus 2547: auth_input_request_forwarding(struct passwd * pw)
1.1 deraadt 2548: {
1.25 markus 2549: int sock, newch;
2550: struct sockaddr_un sunaddr;
2551:
2552: if (auth_get_socket_name() != NULL)
2553: fatal("Protocol error: authentication forwarding requested twice.");
2554:
2555: /* Temporarily drop privileged uid for mkdir/bind. */
1.102 markus 2556: temporarily_use_uid(pw);
1.25 markus 2557:
2558: /* Allocate a buffer for the socket name, and format the name. */
2559: channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);
2560: channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME);
2561: strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);
2562:
2563: /* Create private directory for socket */
1.59 markus 2564: if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {
2565: packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",
2566: strerror(errno));
2567: restore_uid();
2568: xfree(channel_forwarded_auth_socket_name);
2569: xfree(channel_forwarded_auth_socket_dir);
2570: channel_forwarded_auth_socket_name = NULL;
2571: channel_forwarded_auth_socket_dir = NULL;
2572: return 0;
2573: }
1.25 markus 2574: snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",
2575: channel_forwarded_auth_socket_dir, (int) getpid());
2576:
1.109.2.1 jason 2577: /* delete agent socket on fatal() */
2578: fatal_add_cleanup(auth_sock_cleanup_proc, pw);
2579:
1.25 markus 2580: /* Create the socket. */
2581: sock = socket(AF_UNIX, SOCK_STREAM, 0);
2582: if (sock < 0)
2583: packet_disconnect("socket: %.100s", strerror(errno));
2584:
2585: /* Bind it to the name. */
2586: memset(&sunaddr, 0, sizeof(sunaddr));
2587: sunaddr.sun_family = AF_UNIX;
2588: strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name,
2589: sizeof(sunaddr.sun_path));
2590:
2591: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
2592: packet_disconnect("bind: %.100s", strerror(errno));
2593:
2594: /* Restore the privileged uid. */
2595: restore_uid();
2596:
2597: /* Start listening on the socket. */
2598: if (listen(sock, 5) < 0)
2599: packet_disconnect("listen: %.100s", strerror(errno));
2600:
2601: /* Allocate a channel for the authentication agent socket. */
1.73 markus 2602: newch = channel_new("auth socket",
2603: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
2604: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
2605: 0, xstrdup("auth socket"), 1);
2606:
1.32 deraadt 2607: strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
2608: sizeof(channels[newch].path));
1.59 markus 2609: return 1;
1.1 deraadt 2610: }
2611:
2612: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
2613:
1.49 markus 2614: void
1.69 markus 2615: auth_input_open_request(int type, int plen, void *ctxt)
1.1 deraadt 2616: {
1.25 markus 2617: int remch, sock, newch;
2618: char *dummyname;
1.41 markus 2619:
2620: packet_integrity_check(plen, 4, type);
1.25 markus 2621:
2622: /* Read the remote channel number from the message. */
2623: remch = packet_get_int();
2624:
1.27 markus 2625: /*
2626: * Get a connection to the local authentication agent (this may again
2627: * get forwarded).
2628: */
1.25 markus 2629: sock = ssh_get_authentication_socket();
2630:
1.27 markus 2631: /*
2632: * If we could not connect the agent, send an error message back to
2633: * the server. This should never happen unless the agent dies,
2634: * because authentication forwarding is only enabled if we have an
2635: * agent.
2636: */
1.25 markus 2637: if (sock < 0) {
2638: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2639: packet_put_int(remch);
2640: packet_send();
2641: return;
2642: }
2643: debug("Forwarding authentication connection.");
1.1 deraadt 2644:
1.27 markus 2645: /*
2646: * Dummy host name. This will be freed when the channel is freed; it
2647: * will still be valid in the packet_put_string below since the
2648: * channel cannot yet be freed at that point.
2649: */
1.25 markus 2650: dummyname = xstrdup("authentication agent connection");
2651:
2652: newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname);
2653: channels[newch].remote_id = remch;
2654:
2655: /* Send a confirmation to the remote host. */
2656: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
2657: packet_put_int(remch);
2658: packet_put_int(newch);
1.44 markus 2659: packet_send();
2660: }
2661:
2662: void
1.51 markus 2663: channel_start_open(int id)
1.44 markus 2664: {
2665: Channel *c = channel_lookup(id);
2666: if (c == NULL) {
2667: log("channel_open: %d: bad id", id);
2668: return;
2669: }
1.51 markus 2670: debug("send channel open %d", id);
1.44 markus 2671: packet_start(SSH2_MSG_CHANNEL_OPEN);
2672: packet_put_cstring(c->ctype);
2673: packet_put_int(c->self);
2674: packet_put_int(c->local_window);
2675: packet_put_int(c->local_maxpacket);
1.51 markus 2676: }
2677: void
2678: channel_open(int id)
2679: {
2680: /* XXX REMOVE ME */
2681: channel_start_open(id);
1.44 markus 2682: packet_send();
2683: }
2684: void
2685: channel_request(int id, char *service, int wantconfirm)
2686: {
2687: channel_request_start(id, service, wantconfirm);
2688: packet_send();
2689: debug("channel request %d: %s", id, service) ;
2690: }
2691: void
2692: channel_request_start(int id, char *service, int wantconfirm)
2693: {
2694: Channel *c = channel_lookup(id);
2695: if (c == NULL) {
2696: log("channel_request: %d: bad id", id);
2697: return;
2698: }
2699: packet_start(SSH2_MSG_CHANNEL_REQUEST);
2700: packet_put_int(c->remote_id);
2701: packet_put_cstring(service);
2702: packet_put_char(wantconfirm);
2703: }
2704: void
2705: channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
2706: {
2707: Channel *c = channel_lookup(id);
2708: if (c == NULL) {
2709: log("channel_register_callback: %d: bad id", id);
2710: return;
2711: }
2712: c->cb_event = mtype;
2713: c->cb_fn = fn;
2714: c->cb_arg = arg;
2715: }
2716: void
2717: channel_register_cleanup(int id, channel_callback_fn *fn)
2718: {
2719: Channel *c = channel_lookup(id);
2720: if (c == NULL) {
2721: log("channel_register_cleanup: %d: bad id", id);
2722: return;
2723: }
2724: c->dettach_user = fn;
2725: }
2726: void
2727: channel_cancel_cleanup(int id)
2728: {
2729: Channel *c = channel_lookup(id);
2730: if (c == NULL) {
2731: log("channel_cancel_cleanup: %d: bad id", id);
2732: return;
2733: }
2734: c->dettach_user = NULL;
1.65 markus 2735: }
1.89 stevesk 2736: void
1.65 markus 2737: channel_register_filter(int id, channel_filter_fn *fn)
2738: {
2739: Channel *c = channel_lookup(id);
2740: if (c == NULL) {
2741: log("channel_register_filter: %d: bad id", id);
2742: return;
2743: }
2744: c->input_filter = fn;
1.44 markus 2745: }
2746:
2747: void
1.71 markus 2748: channel_set_fds(int id, int rfd, int wfd, int efd,
2749: int extusage, int nonblock)
1.44 markus 2750: {
2751: Channel *c = channel_lookup(id);
2752: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
2753: fatal("channel_activate for non-larval channel %d.", id);
1.71 markus 2754: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
1.44 markus 2755: c->type = SSH_CHANNEL_OPEN;
2756: /* XXX window size? */
1.68 markus 2757: c->local_window = c->local_window_max = c->local_maxpacket * 2;
1.44 markus 2758: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2759: packet_put_int(c->remote_id);
2760: packet_put_int(c->local_window);
1.25 markus 2761: packet_send();
1.1 deraadt 2762: }
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