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Commit | Line | Data |
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8efc0c15 | 1 | /* |
6ae2364d | 2 | * |
5260325f | 3 | * packet.c |
6ae2364d | 4 | * |
5260325f | 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
6ae2364d | 6 | * |
5260325f | 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
8 | * All rights reserved | |
6ae2364d | 9 | * |
5260325f | 10 | * Created: Sat Mar 18 02:40:40 1995 ylo |
6ae2364d | 11 | * |
5260325f | 12 | * This file contains code implementing the packet protocol and communication |
13 | * with the other side. This same code is used both on client and server side. | |
7e7327a1 | 14 | * |
15 | * SSH2 packet format added by Markus Friedl. | |
16 | * | |
5260325f | 17 | */ |
8efc0c15 | 18 | |
19 | #include "includes.h" | |
20 | RCSID("$Id$"); | |
21 | ||
22 | #include "xmalloc.h" | |
23 | #include "buffer.h" | |
24 | #include "packet.h" | |
25 | #include "bufaux.h" | |
26 | #include "ssh.h" | |
27 | #include "crc32.h" | |
28 | #include "cipher.h" | |
29 | #include "getput.h" | |
30 | ||
31 | #include "compress.h" | |
32 | #include "deattack.h" | |
7368a6c8 | 33 | #include "channels.h" |
8efc0c15 | 34 | |
7e7327a1 | 35 | #include "compat.h" |
36 | #include "ssh2.h" | |
37 | ||
35484284 | 38 | #include <openssl/bn.h> |
39 | #include <openssl/dh.h> | |
40 | #include <openssl/hmac.h> | |
7e7327a1 | 41 | #include "buffer.h" |
42 | #include "kex.h" | |
43 | #include "hmac.h" | |
44 | ||
45 | #ifdef PACKET_DEBUG | |
46 | #define DBG(x) x | |
47 | #else | |
48 | #define DBG(x) | |
49 | #endif | |
50 | ||
aa3378df | 51 | /* |
52 | * This variable contains the file descriptors used for communicating with | |
53 | * the other side. connection_in is used for reading; connection_out for | |
54 | * writing. These can be the same descriptor, in which case it is assumed to | |
55 | * be a socket. | |
56 | */ | |
8efc0c15 | 57 | static int connection_in = -1; |
58 | static int connection_out = -1; | |
59 | ||
aa3378df | 60 | /* |
61 | * Cipher type. This value is only used to determine whether to pad the | |
62 | * packets with zeroes or random data. | |
63 | */ | |
8efc0c15 | 64 | static int cipher_type = SSH_CIPHER_NONE; |
65 | ||
66 | /* Protocol flags for the remote side. */ | |
67 | static unsigned int remote_protocol_flags = 0; | |
68 | ||
69 | /* Encryption context for receiving data. This is only used for decryption. */ | |
70 | static CipherContext receive_context; | |
5260325f | 71 | |
72 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 73 | static CipherContext send_context; |
74 | ||
75 | /* Buffer for raw input data from the socket. */ | |
76 | static Buffer input; | |
77 | ||
78 | /* Buffer for raw output data going to the socket. */ | |
79 | static Buffer output; | |
80 | ||
81 | /* Buffer for the partial outgoing packet being constructed. */ | |
82 | static Buffer outgoing_packet; | |
83 | ||
84 | /* Buffer for the incoming packet currently being processed. */ | |
85 | static Buffer incoming_packet; | |
86 | ||
87 | /* Scratch buffer for packet compression/decompression. */ | |
88 | static Buffer compression_buffer; | |
89 | ||
90 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
91 | static int packet_compression = 0; | |
92 | ||
9d6b7add | 93 | /* default maximum packet size */ |
94 | int max_packet_size = 32768; | |
95 | ||
8efc0c15 | 96 | /* Flag indicating whether this module has been initialized. */ |
97 | static int initialized = 0; | |
98 | ||
99 | /* Set to true if the connection is interactive. */ | |
100 | static int interactive_mode = 0; | |
101 | ||
7e7327a1 | 102 | /* True if SSH2 packet format is used */ |
103 | int use_ssh2_packet_format = 0; | |
104 | ||
105 | /* Session key information for Encryption and MAC */ | |
106 | Kex *kex = NULL; | |
107 | ||
108 | void | |
109 | packet_set_kex(Kex *k) | |
110 | { | |
111 | if( k->mac[MODE_IN ].key == NULL || | |
112 | k->enc[MODE_IN ].key == NULL || | |
113 | k->enc[MODE_IN ].iv == NULL || | |
114 | k->mac[MODE_OUT].key == NULL || | |
115 | k->enc[MODE_OUT].key == NULL || | |
116 | k->enc[MODE_OUT].iv == NULL) | |
117 | fatal("bad KEX"); | |
118 | kex = k; | |
119 | } | |
120 | void | |
121 | clear_enc_keys(Enc *enc, int len) | |
122 | { | |
123 | memset(enc->iv, 0, len); | |
124 | memset(enc->key, 0, len); | |
125 | xfree(enc->iv); | |
126 | xfree(enc->key); | |
127 | enc->iv = NULL; | |
128 | enc->key = NULL; | |
129 | } | |
130 | void | |
131 | packet_set_ssh2_format(void) | |
132 | { | |
3189621b | 133 | DBG(debug("use_ssh2_packet_format")); |
7e7327a1 | 134 | use_ssh2_packet_format = 1; |
135 | } | |
136 | ||
aa3378df | 137 | /* |
138 | * Sets the descriptors used for communication. Disables encryption until | |
139 | * packet_set_encryption_key is called. | |
140 | */ | |
8efc0c15 | 141 | void |
142 | packet_set_connection(int fd_in, int fd_out) | |
143 | { | |
5260325f | 144 | connection_in = fd_in; |
145 | connection_out = fd_out; | |
146 | cipher_type = SSH_CIPHER_NONE; | |
8ce64345 | 147 | cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
148 | cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); | |
5260325f | 149 | if (!initialized) { |
150 | initialized = 1; | |
151 | buffer_init(&input); | |
152 | buffer_init(&output); | |
153 | buffer_init(&outgoing_packet); | |
154 | buffer_init(&incoming_packet); | |
155 | } | |
156 | /* Kludge: arrange the close function to be called from fatal(). */ | |
157 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); | |
8efc0c15 | 158 | } |
159 | ||
48e671d5 | 160 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
161 | ||
162 | int | |
163 | packet_connection_is_on_socket() | |
164 | { | |
165 | struct sockaddr_storage from, to; | |
166 | socklen_t fromlen, tolen; | |
167 | ||
168 | /* filedescriptors in and out are the same, so it's a socket */ | |
169 | if (connection_in == connection_out) | |
170 | return 1; | |
171 | fromlen = sizeof(from); | |
172 | memset(&from, 0, sizeof(from)); | |
9bc5ddfe | 173 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
48e671d5 | 174 | return 0; |
175 | tolen = sizeof(to); | |
176 | memset(&to, 0, sizeof(to)); | |
9bc5ddfe | 177 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
48e671d5 | 178 | return 0; |
179 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
180 | return 0; | |
181 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
182 | return 0; | |
183 | return 1; | |
184 | } | |
185 | ||
186 | /* returns 1 if connection is via ipv4 */ | |
187 | ||
188 | int | |
189 | packet_connection_is_ipv4() | |
190 | { | |
191 | struct sockaddr_storage to; | |
d45317d8 | 192 | socklen_t tolen = sizeof(to); |
48e671d5 | 193 | |
194 | memset(&to, 0, sizeof(to)); | |
195 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) | |
196 | return 0; | |
197 | if (to.ss_family != AF_INET) | |
198 | return 0; | |
199 | return 1; | |
200 | } | |
201 | ||
8efc0c15 | 202 | /* Sets the connection into non-blocking mode. */ |
203 | ||
204 | void | |
205 | packet_set_nonblocking() | |
206 | { | |
5260325f | 207 | /* Set the socket into non-blocking mode. */ |
208 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) | |
209 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
8efc0c15 | 210 | |
5260325f | 211 | if (connection_out != connection_in) { |
212 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) | |
213 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
214 | } | |
8efc0c15 | 215 | } |
216 | ||
217 | /* Returns the socket used for reading. */ | |
218 | ||
219 | int | |
220 | packet_get_connection_in() | |
221 | { | |
5260325f | 222 | return connection_in; |
8efc0c15 | 223 | } |
224 | ||
225 | /* Returns the descriptor used for writing. */ | |
226 | ||
227 | int | |
228 | packet_get_connection_out() | |
229 | { | |
5260325f | 230 | return connection_out; |
8efc0c15 | 231 | } |
232 | ||
233 | /* Closes the connection and clears and frees internal data structures. */ | |
234 | ||
235 | void | |
236 | packet_close() | |
237 | { | |
5260325f | 238 | if (!initialized) |
239 | return; | |
240 | initialized = 0; | |
241 | if (connection_in == connection_out) { | |
242 | shutdown(connection_out, SHUT_RDWR); | |
243 | close(connection_out); | |
244 | } else { | |
245 | close(connection_in); | |
246 | close(connection_out); | |
247 | } | |
248 | buffer_free(&input); | |
249 | buffer_free(&output); | |
250 | buffer_free(&outgoing_packet); | |
251 | buffer_free(&incoming_packet); | |
252 | if (packet_compression) { | |
253 | buffer_free(&compression_buffer); | |
254 | buffer_compress_uninit(); | |
255 | } | |
8efc0c15 | 256 | } |
257 | ||
258 | /* Sets remote side protocol flags. */ | |
259 | ||
260 | void | |
261 | packet_set_protocol_flags(unsigned int protocol_flags) | |
262 | { | |
5260325f | 263 | remote_protocol_flags = protocol_flags; |
264 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); | |
8efc0c15 | 265 | } |
266 | ||
267 | /* Returns the remote protocol flags set earlier by the above function. */ | |
268 | ||
269 | unsigned int | |
270 | packet_get_protocol_flags() | |
271 | { | |
5260325f | 272 | return remote_protocol_flags; |
8efc0c15 | 273 | } |
274 | ||
aa3378df | 275 | /* |
276 | * Starts packet compression from the next packet on in both directions. | |
277 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
278 | */ | |
8efc0c15 | 279 | |
7e7327a1 | 280 | /*** XXXXX todo: kex means re-init */ |
8efc0c15 | 281 | void |
282 | packet_start_compression(int level) | |
283 | { | |
5260325f | 284 | if (packet_compression) |
285 | fatal("Compression already enabled."); | |
286 | packet_compression = 1; | |
287 | buffer_init(&compression_buffer); | |
288 | buffer_compress_init(level); | |
8efc0c15 | 289 | } |
290 | ||
aa3378df | 291 | /* |
292 | * Encrypts the given number of bytes, copying from src to dest. bytes is | |
293 | * known to be a multiple of 8. | |
294 | */ | |
8efc0c15 | 295 | |
296 | void | |
5260325f | 297 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
7e7327a1 | 298 | unsigned int bytes) |
8efc0c15 | 299 | { |
5260325f | 300 | cipher_encrypt(cc, dest, src, bytes); |
8efc0c15 | 301 | } |
302 | ||
aa3378df | 303 | /* |
304 | * Decrypts the given number of bytes, copying from src to dest. bytes is | |
305 | * known to be a multiple of 8. | |
306 | */ | |
8efc0c15 | 307 | |
308 | void | |
5260325f | 309 | packet_decrypt(CipherContext * cc, void *dest, void *src, |
7e7327a1 | 310 | unsigned int bytes) |
8efc0c15 | 311 | { |
5260325f | 312 | int i; |
313 | ||
314 | if ((bytes % 8) != 0) | |
315 | fatal("packet_decrypt: bad ciphertext length %d", bytes); | |
316 | ||
aa3378df | 317 | /* |
318 | * Cryptographic attack detector for ssh - Modifications for packet.c | |
319 | * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) | |
320 | */ | |
5260325f | 321 | |
7e7327a1 | 322 | if (cc->type == SSH_CIPHER_NONE || compat20) { |
5260325f | 323 | i = DEATTACK_OK; |
7e7327a1 | 324 | } else { |
5260325f | 325 | i = detect_attack(src, bytes, NULL); |
5260325f | 326 | } |
5260325f | 327 | if (i == DEATTACK_DETECTED) |
328 | packet_disconnect("crc32 compensation attack: network attack detected"); | |
329 | ||
330 | cipher_decrypt(cc, dest, src, bytes); | |
8efc0c15 | 331 | } |
332 | ||
aa3378df | 333 | /* |
334 | * Causes any further packets to be encrypted using the given key. The same | |
335 | * key is used for both sending and reception. However, both directions are | |
336 | * encrypted independently of each other. | |
337 | */ | |
8efc0c15 | 338 | |
339 | void | |
340 | packet_set_encryption_key(const unsigned char *key, unsigned int keylen, | |
7e7327a1 | 341 | int cipher) |
8efc0c15 | 342 | { |
7e7327a1 | 343 | if (keylen < 20) |
344 | fatal("keylen too small: %d", keylen); | |
345 | ||
5260325f | 346 | /* All other ciphers use the same key in both directions for now. */ |
8ce64345 | 347 | cipher_set_key(&receive_context, cipher, key, keylen); |
348 | cipher_set_key(&send_context, cipher, key, keylen); | |
8efc0c15 | 349 | } |
350 | ||
351 | /* Starts constructing a packet to send. */ | |
352 | ||
353 | void | |
7e7327a1 | 354 | packet_start1(int type) |
8efc0c15 | 355 | { |
5260325f | 356 | char buf[9]; |
8efc0c15 | 357 | |
5260325f | 358 | buffer_clear(&outgoing_packet); |
359 | memset(buf, 0, 8); | |
360 | buf[8] = type; | |
361 | buffer_append(&outgoing_packet, buf, 9); | |
8efc0c15 | 362 | } |
363 | ||
7e7327a1 | 364 | void |
365 | packet_start2(int type) | |
366 | { | |
367 | char buf[4+1+1]; | |
368 | ||
369 | buffer_clear(&outgoing_packet); | |
370 | memset(buf, 0, sizeof buf); | |
371 | /* buf[0..3] = payload_len; */ | |
372 | /* buf[4] = pad_len; */ | |
373 | buf[5] = type & 0xff; | |
374 | buffer_append(&outgoing_packet, buf, sizeof buf); | |
375 | } | |
376 | ||
377 | void | |
378 | packet_start(int type) | |
379 | { | |
380 | DBG(debug("packet_start[%d]",type)); | |
381 | if (use_ssh2_packet_format) | |
382 | packet_start2(type); | |
383 | else | |
384 | packet_start1(type); | |
385 | } | |
386 | ||
8efc0c15 | 387 | /* Appends a character to the packet data. */ |
388 | ||
389 | void | |
390 | packet_put_char(int value) | |
391 | { | |
5260325f | 392 | char ch = value; |
393 | buffer_append(&outgoing_packet, &ch, 1); | |
8efc0c15 | 394 | } |
395 | ||
396 | /* Appends an integer to the packet data. */ | |
397 | ||
398 | void | |
399 | packet_put_int(unsigned int value) | |
400 | { | |
5260325f | 401 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 402 | } |
403 | ||
404 | /* Appends a string to packet data. */ | |
405 | ||
406 | void | |
407 | packet_put_string(const char *buf, unsigned int len) | |
408 | { | |
5260325f | 409 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 410 | } |
7e7327a1 | 411 | void |
412 | packet_put_cstring(const char *str) | |
413 | { | |
414 | buffer_put_string(&outgoing_packet, str, strlen(str)); | |
415 | } | |
416 | ||
417 | void | |
418 | packet_put_raw(const char *buf, unsigned int len) | |
419 | { | |
420 | buffer_append(&outgoing_packet, buf, len); | |
421 | } | |
422 | ||
8efc0c15 | 423 | |
424 | /* Appends an arbitrary precision integer to packet data. */ | |
425 | ||
426 | void | |
5260325f | 427 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 428 | { |
5260325f | 429 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 430 | } |
7e7327a1 | 431 | void |
432 | packet_put_bignum2(BIGNUM * value) | |
433 | { | |
434 | buffer_put_bignum2(&outgoing_packet, value); | |
435 | } | |
8efc0c15 | 436 | |
aa3378df | 437 | /* |
438 | * Finalizes and sends the packet. If the encryption key has been set, | |
439 | * encrypts the packet before sending. | |
440 | */ | |
5260325f | 441 | |
8efc0c15 | 442 | void |
7e7327a1 | 443 | packet_send1() |
8efc0c15 | 444 | { |
5260325f | 445 | char buf[8], *cp; |
446 | int i, padding, len; | |
447 | unsigned int checksum; | |
448 | u_int32_t rand = 0; | |
449 | ||
aa3378df | 450 | /* |
451 | * If using packet compression, compress the payload of the outgoing | |
452 | * packet. | |
453 | */ | |
5260325f | 454 | if (packet_compression) { |
455 | buffer_clear(&compression_buffer); | |
456 | /* Skip padding. */ | |
457 | buffer_consume(&outgoing_packet, 8); | |
458 | /* padding */ | |
459 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
460 | buffer_compress(&outgoing_packet, &compression_buffer); | |
461 | buffer_clear(&outgoing_packet); | |
462 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
463 | buffer_len(&compression_buffer)); | |
464 | } | |
465 | /* Compute packet length without padding (add checksum, remove padding). */ | |
466 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
467 | ||
1d1ffb87 | 468 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 469 | padding = 8 - len % 8; |
470 | if (cipher_type != SSH_CIPHER_NONE) { | |
471 | cp = buffer_ptr(&outgoing_packet); | |
472 | for (i = 0; i < padding; i++) { | |
473 | if (i % 4 == 0) | |
474 | rand = arc4random(); | |
475 | cp[7 - i] = rand & 0xff; | |
476 | rand >>= 8; | |
477 | } | |
478 | } | |
479 | buffer_consume(&outgoing_packet, 8 - padding); | |
480 | ||
481 | /* Add check bytes. */ | |
482 | checksum = crc32((unsigned char *) buffer_ptr(&outgoing_packet), | |
483 | buffer_len(&outgoing_packet)); | |
484 | PUT_32BIT(buf, checksum); | |
485 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 486 | |
487 | #ifdef PACKET_DEBUG | |
5260325f | 488 | fprintf(stderr, "packet_send plain: "); |
489 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 490 | #endif |
491 | ||
5260325f | 492 | /* Append to output. */ |
493 | PUT_32BIT(buf, len); | |
494 | buffer_append(&output, buf, 4); | |
495 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
496 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
497 | buffer_len(&outgoing_packet)); | |
498 | ||
8efc0c15 | 499 | #ifdef PACKET_DEBUG |
5260325f | 500 | fprintf(stderr, "encrypted: "); |
501 | buffer_dump(&output); | |
8efc0c15 | 502 | #endif |
503 | ||
5260325f | 504 | buffer_clear(&outgoing_packet); |
8efc0c15 | 505 | |
aa3378df | 506 | /* |
507 | * Note that the packet is now only buffered in output. It won\'t be | |
508 | * actually sent until packet_write_wait or packet_write_poll is | |
509 | * called. | |
510 | */ | |
8efc0c15 | 511 | } |
512 | ||
7e7327a1 | 513 | /* |
514 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
515 | */ | |
516 | void | |
517 | packet_send2() | |
518 | { | |
519 | unsigned char *macbuf = NULL; | |
520 | char *cp; | |
521 | unsigned int packet_length = 0; | |
522 | unsigned int i, padlen, len; | |
523 | u_int32_t rand = 0; | |
6ae2364d | 524 | static unsigned int seqnr = 0; |
7e7327a1 | 525 | int type; |
526 | Enc *enc = NULL; | |
527 | Mac *mac = NULL; | |
528 | Comp *comp = NULL; | |
529 | int block_size; | |
530 | ||
531 | if (kex != NULL) { | |
532 | enc = &kex->enc[MODE_OUT]; | |
533 | mac = &kex->mac[MODE_OUT]; | |
534 | comp = &kex->comp[MODE_OUT]; | |
535 | } | |
536 | block_size = enc ? enc->block_size : 8; | |
537 | ||
538 | cp = buffer_ptr(&outgoing_packet); | |
539 | type = cp[5] & 0xff; | |
540 | ||
541 | #ifdef PACKET_DEBUG | |
542 | fprintf(stderr, "plain: "); | |
543 | buffer_dump(&outgoing_packet); | |
544 | #endif | |
545 | ||
546 | if (comp && comp->enabled) { | |
547 | len = buffer_len(&outgoing_packet); | |
548 | /* skip header, compress only payload */ | |
549 | buffer_consume(&outgoing_packet, 5); | |
550 | buffer_clear(&compression_buffer); | |
551 | buffer_compress(&outgoing_packet, &compression_buffer); | |
552 | buffer_clear(&outgoing_packet); | |
553 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); | |
554 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
555 | buffer_len(&compression_buffer)); | |
556 | DBG(debug("compression: raw %d compressed %d", len, | |
557 | buffer_len(&outgoing_packet))); | |
558 | } | |
559 | ||
560 | /* sizeof (packet_len + pad_len + payload) */ | |
561 | len = buffer_len(&outgoing_packet); | |
562 | ||
563 | /* | |
564 | * calc size of padding, alloc space, get random data, | |
565 | * minimum padding is 4 bytes | |
566 | */ | |
567 | padlen = block_size - (len % block_size); | |
568 | if (padlen < 4) | |
569 | padlen += block_size; | |
570 | buffer_append_space(&outgoing_packet, &cp, padlen); | |
571 | if (enc && enc->type != SSH_CIPHER_NONE) { | |
1d1ffb87 | 572 | /* random padding */ |
7e7327a1 | 573 | for (i = 0; i < padlen; i++) { |
574 | if (i % 4 == 0) | |
575 | rand = arc4random(); | |
576 | cp[i] = rand & 0xff; | |
577 | rand <<= 8; | |
578 | } | |
1d1ffb87 | 579 | } else { |
580 | /* clear padding */ | |
581 | memset(cp, 0, padlen); | |
7e7327a1 | 582 | } |
583 | /* packet_length includes payload, padding and padding length field */ | |
584 | packet_length = buffer_len(&outgoing_packet) - 4; | |
585 | cp = buffer_ptr(&outgoing_packet); | |
586 | PUT_32BIT(cp, packet_length); | |
587 | cp[4] = padlen & 0xff; | |
588 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); | |
589 | ||
590 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
591 | if (mac && mac->enabled) { | |
592 | macbuf = hmac( mac->md, seqnr, | |
593 | (unsigned char *) buffer_ptr(&outgoing_packet), | |
594 | buffer_len(&outgoing_packet), | |
595 | mac->key, mac->key_len | |
596 | ); | |
597 | DBG(debug("done calc HMAC out #%d", seqnr)); | |
598 | } | |
599 | /* encrypt packet and append to output buffer. */ | |
600 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
601 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
602 | buffer_len(&outgoing_packet)); | |
603 | /* append unencrypted MAC */ | |
604 | if (mac && mac->enabled) | |
605 | buffer_append(&output, (char *)macbuf, mac->mac_len); | |
606 | #ifdef PACKET_DEBUG | |
607 | fprintf(stderr, "encrypted: "); | |
608 | buffer_dump(&output); | |
609 | #endif | |
6ae2364d | 610 | /* increment sequence number for outgoing packets */ |
611 | if (++seqnr == 0) | |
612 | log("outgoing seqnr wraps around"); | |
7e7327a1 | 613 | buffer_clear(&outgoing_packet); |
614 | ||
615 | if (type == SSH2_MSG_NEWKEYS) { | |
616 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
617 | fatal("packet_send2: no KEX"); | |
618 | if (mac->md != NULL) | |
619 | mac->enabled = 1; | |
3189621b | 620 | DBG(debug("cipher_set_key_iv send_context")); |
7e7327a1 | 621 | cipher_set_key_iv(&send_context, enc->type, |
622 | enc->key, enc->key_len, | |
623 | enc->iv, enc->iv_len); | |
624 | clear_enc_keys(enc, kex->we_need); | |
625 | if (comp->type != 0 && comp->enabled == 0) { | |
626 | comp->enabled = 1; | |
627 | if (! packet_compression) | |
628 | packet_start_compression(6); | |
629 | } | |
630 | } | |
631 | } | |
632 | ||
633 | void | |
634 | packet_send() | |
635 | { | |
636 | if (use_ssh2_packet_format) | |
637 | packet_send2(); | |
638 | else | |
639 | packet_send1(); | |
640 | DBG(debug("packet_send done")); | |
641 | } | |
642 | ||
aa3378df | 643 | /* |
644 | * Waits until a packet has been received, and returns its type. Note that | |
645 | * no other data is processed until this returns, so this function should not | |
646 | * be used during the interactive session. | |
647 | */ | |
8efc0c15 | 648 | |
649 | int | |
650 | packet_read(int *payload_len_ptr) | |
651 | { | |
5260325f | 652 | int type, len; |
653 | fd_set set; | |
654 | char buf[8192]; | |
7e7327a1 | 655 | DBG(debug("packet_read()")); |
5260325f | 656 | |
657 | /* Since we are blocking, ensure that all written packets have been sent. */ | |
658 | packet_write_wait(); | |
659 | ||
660 | /* Stay in the loop until we have received a complete packet. */ | |
661 | for (;;) { | |
662 | /* Try to read a packet from the buffer. */ | |
663 | type = packet_read_poll(payload_len_ptr); | |
1d1ffb87 | 664 | if (!use_ssh2_packet_format && ( |
665 | type == SSH_SMSG_SUCCESS | |
5260325f | 666 | || type == SSH_SMSG_FAILURE |
667 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 668 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
5260325f | 669 | packet_integrity_check(*payload_len_ptr, 0, type); |
670 | /* If we got a packet, return it. */ | |
671 | if (type != SSH_MSG_NONE) | |
672 | return type; | |
aa3378df | 673 | /* |
674 | * Otherwise, wait for some data to arrive, add it to the | |
675 | * buffer, and try again. | |
676 | */ | |
5260325f | 677 | FD_ZERO(&set); |
678 | FD_SET(connection_in, &set); | |
aa3378df | 679 | |
5260325f | 680 | /* Wait for some data to arrive. */ |
681 | select(connection_in + 1, &set, NULL, NULL, NULL); | |
aa3378df | 682 | |
5260325f | 683 | /* Read data from the socket. */ |
684 | len = read(connection_in, buf, sizeof(buf)); | |
89cafde6 | 685 | if (len == 0) { |
686 | log("Connection closed by %.200s", get_remote_ipaddr()); | |
687 | fatal_cleanup(); | |
688 | } | |
5260325f | 689 | if (len < 0) |
690 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
691 | /* Append it to the buffer. */ | |
692 | packet_process_incoming(buf, len); | |
693 | } | |
694 | /* NOTREACHED */ | |
8efc0c15 | 695 | } |
696 | ||
aa3378df | 697 | /* |
698 | * Waits until a packet has been received, verifies that its type matches | |
699 | * that given, and gives a fatal error and exits if there is a mismatch. | |
700 | */ | |
8efc0c15 | 701 | |
702 | void | |
703 | packet_read_expect(int *payload_len_ptr, int expected_type) | |
704 | { | |
5260325f | 705 | int type; |
8efc0c15 | 706 | |
5260325f | 707 | type = packet_read(payload_len_ptr); |
708 | if (type != expected_type) | |
709 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 710 | expected_type, type); |
8efc0c15 | 711 | } |
712 | ||
713 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 714 | * packet_process_incoming. If so, reads the packet; otherwise returns |
715 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
716 | * | |
717 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
718 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
719 | * to higher levels. | |
720 | * | |
721 | * The returned payload_len does include space consumed by: | |
722 | * Packet length | |
723 | * Padding | |
724 | * Packet type | |
725 | * Check bytes | |
726 | */ | |
8efc0c15 | 727 | |
728 | int | |
7e7327a1 | 729 | packet_read_poll1(int *payload_len_ptr) |
8efc0c15 | 730 | { |
5260325f | 731 | unsigned int len, padded_len; |
732 | unsigned char *ucp; | |
7e7327a1 | 733 | char buf[8], *cp; |
5260325f | 734 | unsigned int checksum, stored_checksum; |
735 | ||
5260325f | 736 | /* Check if input size is less than minimum packet size. */ |
737 | if (buffer_len(&input) < 4 + 8) | |
738 | return SSH_MSG_NONE; | |
739 | /* Get length of incoming packet. */ | |
740 | ucp = (unsigned char *) buffer_ptr(&input); | |
741 | len = GET_32BIT(ucp); | |
742 | if (len < 1 + 2 + 2 || len > 256 * 1024) | |
743 | packet_disconnect("Bad packet length %d.", len); | |
744 | padded_len = (len + 8) & ~7; | |
745 | ||
746 | /* Check if the packet has been entirely received. */ | |
747 | if (buffer_len(&input) < 4 + padded_len) | |
748 | return SSH_MSG_NONE; | |
749 | ||
750 | /* The entire packet is in buffer. */ | |
751 | ||
752 | /* Consume packet length. */ | |
753 | buffer_consume(&input, 4); | |
754 | ||
755 | /* Copy data to incoming_packet. */ | |
756 | buffer_clear(&incoming_packet); | |
757 | buffer_append_space(&incoming_packet, &cp, padded_len); | |
758 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); | |
759 | buffer_consume(&input, padded_len); | |
8efc0c15 | 760 | |
761 | #ifdef PACKET_DEBUG | |
5260325f | 762 | fprintf(stderr, "read_poll plain: "); |
763 | buffer_dump(&incoming_packet); | |
8efc0c15 | 764 | #endif |
5260325f | 765 | |
766 | /* Compute packet checksum. */ | |
767 | checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet), | |
7e7327a1 | 768 | buffer_len(&incoming_packet) - 4); |
5260325f | 769 | |
770 | /* Skip padding. */ | |
771 | buffer_consume(&incoming_packet, 8 - len % 8); | |
772 | ||
773 | /* Test check bytes. */ | |
774 | ||
775 | if (len != buffer_len(&incoming_packet)) | |
776 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", | |
7e7327a1 | 777 | len, buffer_len(&incoming_packet)); |
5260325f | 778 | |
779 | ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4; | |
780 | stored_checksum = GET_32BIT(ucp); | |
781 | if (checksum != stored_checksum) | |
782 | packet_disconnect("Corrupted check bytes on input."); | |
783 | buffer_consume_end(&incoming_packet, 4); | |
784 | ||
785 | /* If using packet compression, decompress the packet. */ | |
786 | if (packet_compression) { | |
787 | buffer_clear(&compression_buffer); | |
788 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
789 | buffer_clear(&incoming_packet); | |
790 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
7e7327a1 | 791 | buffer_len(&compression_buffer)); |
5260325f | 792 | } |
793 | /* Get packet type. */ | |
794 | buffer_get(&incoming_packet, &buf[0], 1); | |
795 | ||
796 | /* Return length of payload (without type field). */ | |
797 | *payload_len_ptr = buffer_len(&incoming_packet); | |
798 | ||
5260325f | 799 | /* Return type. */ |
800 | return (unsigned char) buf[0]; | |
801 | } | |
802 | ||
7e7327a1 | 803 | int |
804 | packet_read_poll2(int *payload_len_ptr) | |
805 | { | |
806 | unsigned int padlen, need; | |
807 | unsigned char buf[8], *macbuf; | |
808 | unsigned char *ucp; | |
809 | char *cp; | |
810 | static unsigned int packet_length = 0; | |
811 | static unsigned int seqnr = 0; | |
812 | int type; | |
813 | int maclen, block_size; | |
814 | Enc *enc = NULL; | |
815 | Mac *mac = NULL; | |
816 | Comp *comp = NULL; | |
817 | ||
818 | if (kex != NULL) { | |
819 | enc = &kex->enc[MODE_IN]; | |
820 | mac = &kex->mac[MODE_IN]; | |
821 | comp = &kex->comp[MODE_IN]; | |
822 | } | |
823 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
824 | block_size = enc ? enc->block_size : 8; | |
825 | ||
826 | if (packet_length == 0) { | |
827 | /* | |
828 | * check if input size is less than the cipher block size, | |
829 | * decrypt first block and extract length of incoming packet | |
830 | */ | |
831 | if (buffer_len(&input) < block_size) | |
832 | return SSH_MSG_NONE; | |
833 | buffer_clear(&incoming_packet); | |
834 | buffer_append_space(&incoming_packet, &cp, block_size); | |
835 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), | |
836 | block_size); | |
837 | ucp = (unsigned char *) buffer_ptr(&incoming_packet); | |
838 | packet_length = GET_32BIT(ucp); | |
839 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { | |
840 | buffer_dump(&incoming_packet); | |
841 | packet_disconnect("Bad packet length %d.", packet_length); | |
842 | } | |
843 | DBG(debug("input: packet len %d", packet_length+4)); | |
844 | buffer_consume(&input, block_size); | |
845 | } | |
846 | /* we have a partial packet of block_size bytes */ | |
847 | need = 4 + packet_length - block_size; | |
848 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, | |
849 | need, maclen)); | |
850 | if (need % block_size != 0) | |
851 | fatal("padding error: need %d block %d mod %d", | |
852 | need, block_size, need % block_size); | |
853 | /* | |
854 | * check if the entire packet has been received and | |
855 | * decrypt into incoming_packet | |
856 | */ | |
857 | if (buffer_len(&input) < need + maclen) | |
858 | return SSH_MSG_NONE; | |
859 | #ifdef PACKET_DEBUG | |
860 | fprintf(stderr, "read_poll enc/full: "); | |
861 | buffer_dump(&input); | |
862 | #endif | |
863 | buffer_append_space(&incoming_packet, &cp, need); | |
864 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); | |
865 | buffer_consume(&input, need); | |
866 | /* | |
867 | * compute MAC over seqnr and packet, | |
868 | * increment sequence number for incoming packet | |
869 | */ | |
6ae2364d | 870 | if (mac && mac->enabled) { |
7e7327a1 | 871 | macbuf = hmac( mac->md, seqnr, |
872 | (unsigned char *) buffer_ptr(&incoming_packet), | |
873 | buffer_len(&incoming_packet), | |
874 | mac->key, mac->key_len | |
875 | ); | |
876 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) | |
877 | packet_disconnect("Corrupted HMAC on input."); | |
878 | DBG(debug("HMAC #%d ok", seqnr)); | |
879 | buffer_consume(&input, mac->mac_len); | |
880 | } | |
6ae2364d | 881 | if (++seqnr == 0) |
882 | log("incoming seqnr wraps around"); | |
7e7327a1 | 883 | |
884 | /* get padlen */ | |
885 | cp = buffer_ptr(&incoming_packet) + 4; | |
886 | padlen = *cp & 0xff; | |
887 | DBG(debug("input: padlen %d", padlen)); | |
888 | if (padlen < 4) | |
889 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
890 | ||
891 | /* skip packet size + padlen, discard padding */ | |
892 | buffer_consume(&incoming_packet, 4 + 1); | |
893 | buffer_consume_end(&incoming_packet, padlen); | |
894 | ||
895 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); | |
896 | if (comp && comp->enabled) { | |
897 | buffer_clear(&compression_buffer); | |
898 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
899 | buffer_clear(&incoming_packet); | |
900 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
901 | buffer_len(&compression_buffer)); | |
902 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); | |
903 | } | |
904 | /* | |
905 | * get packet type, implies consume. | |
906 | * return length of payload (without type field) | |
907 | */ | |
908 | buffer_get(&incoming_packet, (char *)&buf[0], 1); | |
909 | *payload_len_ptr = buffer_len(&incoming_packet); | |
910 | ||
911 | /* reset for next packet */ | |
912 | packet_length = 0; | |
913 | ||
914 | /* extract packet type */ | |
915 | type = (unsigned char)buf[0]; | |
916 | ||
917 | if (type == SSH2_MSG_NEWKEYS) { | |
918 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
919 | fatal("packet_read_poll2: no KEX"); | |
920 | if (mac->md != NULL) | |
921 | mac->enabled = 1; | |
3189621b | 922 | DBG(debug("cipher_set_key_iv receive_context")); |
7e7327a1 | 923 | cipher_set_key_iv(&receive_context, enc->type, |
924 | enc->key, enc->key_len, | |
925 | enc->iv, enc->iv_len); | |
926 | clear_enc_keys(enc, kex->we_need); | |
927 | if (comp->type != 0 && comp->enabled == 0) { | |
928 | comp->enabled = 1; | |
929 | if (! packet_compression) | |
930 | packet_start_compression(6); | |
931 | } | |
932 | } | |
933 | ||
934 | #ifdef PACKET_DEBUG | |
935 | fprintf(stderr, "read/plain[%d]:\r\n",type); | |
936 | buffer_dump(&incoming_packet); | |
937 | #endif | |
938 | return (unsigned char)type; | |
939 | } | |
940 | ||
941 | int | |
942 | packet_read_poll(int *payload_len_ptr) | |
943 | { | |
944 | char *msg; | |
945 | for (;;) { | |
946 | int type = use_ssh2_packet_format ? | |
947 | packet_read_poll2(payload_len_ptr): | |
948 | packet_read_poll1(payload_len_ptr); | |
949 | ||
950 | if(compat20) { | |
951 | int reason; | |
952 | if (type != 0) | |
953 | DBG(debug("received packet type %d", type)); | |
954 | switch(type) { | |
955 | case SSH2_MSG_IGNORE: | |
956 | break; | |
957 | case SSH2_MSG_DEBUG: | |
958 | packet_get_char(); | |
959 | msg = packet_get_string(NULL); | |
960 | debug("Remote: %.900s", msg); | |
961 | xfree(msg); | |
962 | msg = packet_get_string(NULL); | |
963 | xfree(msg); | |
964 | break; | |
965 | case SSH2_MSG_DISCONNECT: | |
966 | reason = packet_get_int(); | |
967 | msg = packet_get_string(NULL); | |
968 | log("Received disconnect: %d: %.900s", reason, msg); | |
969 | xfree(msg); | |
970 | fatal_cleanup(); | |
971 | break; | |
972 | default: | |
973 | return type; | |
974 | break; | |
975 | } | |
976 | } else { | |
977 | switch(type) { | |
978 | case SSH_MSG_IGNORE: | |
979 | break; | |
980 | case SSH_MSG_DEBUG: | |
981 | msg = packet_get_string(NULL); | |
982 | debug("Remote: %.900s", msg); | |
983 | xfree(msg); | |
984 | break; | |
985 | case SSH_MSG_DISCONNECT: | |
986 | msg = packet_get_string(NULL); | |
987 | log("Received disconnect: %.900s", msg); | |
988 | fatal_cleanup(); | |
989 | xfree(msg); | |
990 | break; | |
991 | default: | |
992 | if (type != 0) | |
993 | DBG(debug("received packet type %d", type)); | |
994 | return type; | |
995 | break; | |
996 | } | |
997 | } | |
998 | } | |
999 | } | |
1000 | ||
aa3378df | 1001 | /* |
1002 | * Buffers the given amount of input characters. This is intended to be used | |
1003 | * together with packet_read_poll. | |
1004 | */ | |
8efc0c15 | 1005 | |
1006 | void | |
1007 | packet_process_incoming(const char *buf, unsigned int len) | |
1008 | { | |
5260325f | 1009 | buffer_append(&input, buf, len); |
8efc0c15 | 1010 | } |
1011 | ||
1012 | /* Returns a character from the packet. */ | |
1013 | ||
1014 | unsigned int | |
1015 | packet_get_char() | |
1016 | { | |
5260325f | 1017 | char ch; |
1018 | buffer_get(&incoming_packet, &ch, 1); | |
1019 | return (unsigned char) ch; | |
8efc0c15 | 1020 | } |
1021 | ||
1022 | /* Returns an integer from the packet data. */ | |
1023 | ||
1024 | unsigned int | |
1025 | packet_get_int() | |
1026 | { | |
5260325f | 1027 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 1028 | } |
1029 | ||
aa3378df | 1030 | /* |
1031 | * Returns an arbitrary precision integer from the packet data. The integer | |
1032 | * must have been initialized before this call. | |
1033 | */ | |
8efc0c15 | 1034 | |
1035 | void | |
5260325f | 1036 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
8efc0c15 | 1037 | { |
5260325f | 1038 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 1039 | } |
1040 | ||
7e7327a1 | 1041 | void |
1042 | packet_get_bignum2(BIGNUM * value, int *length_ptr) | |
1043 | { | |
1044 | *length_ptr = buffer_get_bignum2(&incoming_packet, value); | |
1045 | } | |
1046 | ||
1047 | char * | |
1048 | packet_get_raw(int *length_ptr) | |
1049 | { | |
1050 | int bytes = buffer_len(&incoming_packet); | |
1051 | if (length_ptr != NULL) | |
1052 | *length_ptr = bytes; | |
1053 | return buffer_ptr(&incoming_packet); | |
1054 | } | |
1055 | ||
6ae2364d | 1056 | int |
1057 | packet_remaining(void) | |
1058 | { | |
1059 | return buffer_len(&incoming_packet); | |
1060 | } | |
1061 | ||
aa3378df | 1062 | /* |
1063 | * Returns a string from the packet data. The string is allocated using | |
1064 | * xmalloc; it is the responsibility of the calling program to free it when | |
1065 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1066 | * integer into which the length of the string is stored. | |
1067 | */ | |
8efc0c15 | 1068 | |
aa3378df | 1069 | char * |
5260325f | 1070 | packet_get_string(unsigned int *length_ptr) |
8efc0c15 | 1071 | { |
5260325f | 1072 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 1073 | } |
1074 | ||
aa3378df | 1075 | /* |
1076 | * Sends a diagnostic message from the server to the client. This message | |
1077 | * can be sent at any time (but not while constructing another message). The | |
1078 | * message is printed immediately, but only if the client is being executed | |
1079 | * in verbose mode. These messages are primarily intended to ease debugging | |
1080 | * authentication problems. The length of the formatted message must not | |
1081 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1082 | */ | |
8efc0c15 | 1083 | |
1084 | void | |
5260325f | 1085 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1086 | { |
5260325f | 1087 | char buf[1024]; |
1088 | va_list args; | |
1089 | ||
1090 | va_start(args, fmt); | |
1091 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1092 | va_end(args); | |
1093 | ||
c4bc58eb | 1094 | if (compat20) { |
1095 | packet_start(SSH2_MSG_DEBUG); | |
1096 | packet_put_char(0); /* bool: always display */ | |
1097 | packet_put_cstring(buf); | |
1098 | packet_put_cstring(""); | |
1099 | } else { | |
1100 | packet_start(SSH_MSG_DEBUG); | |
1101 | packet_put_cstring(buf); | |
1102 | } | |
5260325f | 1103 | packet_send(); |
1104 | packet_write_wait(); | |
8efc0c15 | 1105 | } |
1106 | ||
aa3378df | 1107 | /* |
1108 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1109 | * connection, and exits. This function never returns. The error message | |
1110 | * should not contain a newline. The length of the formatted message must | |
1111 | * not exceed 1024 bytes. | |
1112 | */ | |
8efc0c15 | 1113 | |
1114 | void | |
5260325f | 1115 | packet_disconnect(const char *fmt,...) |
1116 | { | |
1117 | char buf[1024]; | |
1118 | va_list args; | |
1119 | static int disconnecting = 0; | |
1120 | if (disconnecting) /* Guard against recursive invocations. */ | |
1121 | fatal("packet_disconnect called recursively."); | |
1122 | disconnecting = 1; | |
1123 | ||
aa3378df | 1124 | /* |
1125 | * Format the message. Note that the caller must make sure the | |
1126 | * message is of limited size. | |
1127 | */ | |
5260325f | 1128 | va_start(args, fmt); |
1129 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1130 | va_end(args); | |
1131 | ||
1132 | /* Send the disconnect message to the other side, and wait for it to get sent. */ | |
7e7327a1 | 1133 | if (compat20) { |
1134 | packet_start(SSH2_MSG_DISCONNECT); | |
1135 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1136 | packet_put_cstring(buf); | |
1137 | packet_put_cstring(""); | |
1138 | } else { | |
1139 | packet_start(SSH_MSG_DISCONNECT); | |
1140 | packet_put_string(buf, strlen(buf)); | |
1141 | } | |
5260325f | 1142 | packet_send(); |
1143 | packet_write_wait(); | |
1144 | ||
1145 | /* Stop listening for connections. */ | |
1146 | channel_stop_listening(); | |
1147 | ||
1148 | /* Close the connection. */ | |
1149 | packet_close(); | |
1150 | ||
1151 | /* Display the error locally and exit. */ | |
57112b5a | 1152 | log("Disconnecting: %.100s", buf); |
1153 | fatal_cleanup(); | |
8efc0c15 | 1154 | } |
1155 | ||
aa3378df | 1156 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1157 | |
1158 | void | |
1159 | packet_write_poll() | |
1160 | { | |
5260325f | 1161 | int len = buffer_len(&output); |
1162 | if (len > 0) { | |
1163 | len = write(connection_out, buffer_ptr(&output), len); | |
1164 | if (len <= 0) { | |
1165 | if (errno == EAGAIN) | |
1166 | return; | |
1167 | else | |
1168 | fatal("Write failed: %.100s", strerror(errno)); | |
1169 | } | |
1170 | buffer_consume(&output, len); | |
1171 | } | |
8efc0c15 | 1172 | } |
1173 | ||
aa3378df | 1174 | /* |
1175 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1176 | * written. | |
1177 | */ | |
8efc0c15 | 1178 | |
1179 | void | |
1180 | packet_write_wait() | |
1181 | { | |
5260325f | 1182 | packet_write_poll(); |
1183 | while (packet_have_data_to_write()) { | |
1184 | fd_set set; | |
1185 | FD_ZERO(&set); | |
1186 | FD_SET(connection_out, &set); | |
1187 | select(connection_out + 1, NULL, &set, NULL, NULL); | |
1188 | packet_write_poll(); | |
1189 | } | |
8efc0c15 | 1190 | } |
1191 | ||
1192 | /* Returns true if there is buffered data to write to the connection. */ | |
1193 | ||
1194 | int | |
1195 | packet_have_data_to_write() | |
1196 | { | |
5260325f | 1197 | return buffer_len(&output) != 0; |
8efc0c15 | 1198 | } |
1199 | ||
1200 | /* Returns true if there is not too much data to write to the connection. */ | |
1201 | ||
1202 | int | |
1203 | packet_not_very_much_data_to_write() | |
1204 | { | |
5260325f | 1205 | if (interactive_mode) |
1206 | return buffer_len(&output) < 16384; | |
1207 | else | |
1208 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 1209 | } |
1210 | ||
1211 | /* Informs that the current session is interactive. Sets IP flags for that. */ | |
1212 | ||
1213 | void | |
1214 | packet_set_interactive(int interactive, int keepalives) | |
1215 | { | |
5260325f | 1216 | int on = 1; |
1217 | ||
1218 | /* Record that we are in interactive mode. */ | |
1219 | interactive_mode = interactive; | |
1220 | ||
48e671d5 | 1221 | /* Only set socket options if using a socket. */ |
1222 | if (!packet_connection_is_on_socket()) | |
5260325f | 1223 | return; |
5260325f | 1224 | if (keepalives) { |
1225 | /* Set keepalives if requested. */ | |
1226 | if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, | |
48e671d5 | 1227 | sizeof(on)) < 0) |
5260325f | 1228 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
1229 | } | |
48e671d5 | 1230 | /* |
1231 | * IPTOS_LOWDELAY, TCP_NODELAY and IPTOS_THROUGHPUT are IPv4 only | |
1232 | */ | |
1233 | if (!packet_connection_is_ipv4()) | |
1234 | return; | |
5260325f | 1235 | if (interactive) { |
aa3378df | 1236 | /* |
1237 | * Set IP options for an interactive connection. Use | |
1238 | * IPTOS_LOWDELAY and TCP_NODELAY. | |
1239 | */ | |
c04f75f1 | 1240 | #ifdef IP_TOS |
5260325f | 1241 | int lowdelay = IPTOS_LOWDELAY; |
1242 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay, | |
48e671d5 | 1243 | sizeof(lowdelay)) < 0) |
5260325f | 1244 | error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno)); |
c04f75f1 | 1245 | #endif |
5260325f | 1246 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
48e671d5 | 1247 | sizeof(on)) < 0) |
5260325f | 1248 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
1249 | } else { | |
aa3378df | 1250 | /* |
1251 | * Set IP options for a non-interactive connection. Use | |
1252 | * IPTOS_THROUGHPUT. | |
1253 | */ | |
c04f75f1 | 1254 | #ifdef IP_TOS |
5260325f | 1255 | int throughput = IPTOS_THROUGHPUT; |
1256 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, | |
48e671d5 | 1257 | sizeof(throughput)) < 0) |
5260325f | 1258 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
c04f75f1 | 1259 | #endif |
5260325f | 1260 | } |
8efc0c15 | 1261 | } |
1262 | ||
1263 | /* Returns true if the current connection is interactive. */ | |
1264 | ||
1265 | int | |
1266 | packet_is_interactive() | |
1267 | { | |
5260325f | 1268 | return interactive_mode; |
8efc0c15 | 1269 | } |
9d6b7add | 1270 | |
1271 | int | |
1272 | packet_set_maxsize(int s) | |
1273 | { | |
5260325f | 1274 | static int called = 0; |
1275 | if (called) { | |
7e7327a1 | 1276 | log("packet_set_maxsize: called twice: old %d new %d", |
1277 | max_packet_size, s); | |
5260325f | 1278 | return -1; |
1279 | } | |
1280 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
1281 | log("packet_set_maxsize: bad size %d", s); | |
1282 | return -1; | |
1283 | } | |
1284 | log("packet_set_maxsize: setting to %d", s); | |
1285 | max_packet_size = s; | |
1286 | return s; | |
9d6b7add | 1287 | } |