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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 2 | * |
3 | * packet.c | |
4 | * | |
5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
6 | * | |
7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
8 | * All rights reserved | |
9 | * | |
10 | * Created: Sat Mar 18 02:40:40 1995 ylo | |
11 | * | |
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. | |
14 | * | |
15 | */ | |
8efc0c15 | 16 | |
17 | #include "includes.h" | |
18 | RCSID("$Id$"); | |
19 | ||
20 | #include "xmalloc.h" | |
21 | #include "buffer.h" | |
22 | #include "packet.h" | |
23 | #include "bufaux.h" | |
24 | #include "ssh.h" | |
25 | #include "crc32.h" | |
26 | #include "cipher.h" | |
27 | #include "getput.h" | |
28 | ||
29 | #include "compress.h" | |
30 | #include "deattack.h" | |
31 | ||
32 | /* This variable contains the file descriptors used for communicating with | |
33 | the other side. connection_in is used for reading; connection_out | |
34 | for writing. These can be the same descriptor, in which case it is | |
35 | assumed to be a socket. */ | |
36 | static int connection_in = -1; | |
37 | static int connection_out = -1; | |
38 | ||
39 | /* Cipher type. This value is only used to determine whether to pad the | |
40 | packets with zeroes or random data. */ | |
41 | static int cipher_type = SSH_CIPHER_NONE; | |
42 | ||
43 | /* Protocol flags for the remote side. */ | |
44 | static unsigned int remote_protocol_flags = 0; | |
45 | ||
46 | /* Encryption context for receiving data. This is only used for decryption. */ | |
47 | static CipherContext receive_context; | |
5260325f | 48 | |
49 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 50 | static CipherContext send_context; |
51 | ||
52 | /* Buffer for raw input data from the socket. */ | |
53 | static Buffer input; | |
54 | ||
55 | /* Buffer for raw output data going to the socket. */ | |
56 | static Buffer output; | |
57 | ||
58 | /* Buffer for the partial outgoing packet being constructed. */ | |
59 | static Buffer outgoing_packet; | |
60 | ||
61 | /* Buffer for the incoming packet currently being processed. */ | |
62 | static Buffer incoming_packet; | |
63 | ||
64 | /* Scratch buffer for packet compression/decompression. */ | |
65 | static Buffer compression_buffer; | |
66 | ||
67 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
68 | static int packet_compression = 0; | |
69 | ||
9d6b7add | 70 | /* default maximum packet size */ |
71 | int max_packet_size = 32768; | |
72 | ||
8efc0c15 | 73 | /* Flag indicating whether this module has been initialized. */ |
74 | static int initialized = 0; | |
75 | ||
76 | /* Set to true if the connection is interactive. */ | |
77 | static int interactive_mode = 0; | |
78 | ||
79 | /* Sets the descriptors used for communication. Disables encryption until | |
80 | packet_set_encryption_key is called. */ | |
81 | ||
82 | void | |
83 | packet_set_connection(int fd_in, int fd_out) | |
84 | { | |
5260325f | 85 | connection_in = fd_in; |
86 | connection_out = fd_out; | |
87 | cipher_type = SSH_CIPHER_NONE; | |
88 | cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0, 1); | |
89 | cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0, 0); | |
90 | if (!initialized) { | |
91 | initialized = 1; | |
92 | buffer_init(&input); | |
93 | buffer_init(&output); | |
94 | buffer_init(&outgoing_packet); | |
95 | buffer_init(&incoming_packet); | |
96 | } | |
97 | /* Kludge: arrange the close function to be called from fatal(). */ | |
98 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); | |
8efc0c15 | 99 | } |
100 | ||
101 | /* Sets the connection into non-blocking mode. */ | |
102 | ||
103 | void | |
104 | packet_set_nonblocking() | |
105 | { | |
5260325f | 106 | /* Set the socket into non-blocking mode. */ |
107 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) | |
108 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
8efc0c15 | 109 | |
5260325f | 110 | if (connection_out != connection_in) { |
111 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) | |
112 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
113 | } | |
8efc0c15 | 114 | } |
115 | ||
116 | /* Returns the socket used for reading. */ | |
117 | ||
118 | int | |
119 | packet_get_connection_in() | |
120 | { | |
5260325f | 121 | return connection_in; |
8efc0c15 | 122 | } |
123 | ||
124 | /* Returns the descriptor used for writing. */ | |
125 | ||
126 | int | |
127 | packet_get_connection_out() | |
128 | { | |
5260325f | 129 | return connection_out; |
8efc0c15 | 130 | } |
131 | ||
132 | /* Closes the connection and clears and frees internal data structures. */ | |
133 | ||
134 | void | |
135 | packet_close() | |
136 | { | |
5260325f | 137 | if (!initialized) |
138 | return; | |
139 | initialized = 0; | |
140 | if (connection_in == connection_out) { | |
141 | shutdown(connection_out, SHUT_RDWR); | |
142 | close(connection_out); | |
143 | } else { | |
144 | close(connection_in); | |
145 | close(connection_out); | |
146 | } | |
147 | buffer_free(&input); | |
148 | buffer_free(&output); | |
149 | buffer_free(&outgoing_packet); | |
150 | buffer_free(&incoming_packet); | |
151 | if (packet_compression) { | |
152 | buffer_free(&compression_buffer); | |
153 | buffer_compress_uninit(); | |
154 | } | |
8efc0c15 | 155 | } |
156 | ||
157 | /* Sets remote side protocol flags. */ | |
158 | ||
159 | void | |
160 | packet_set_protocol_flags(unsigned int protocol_flags) | |
161 | { | |
5260325f | 162 | remote_protocol_flags = protocol_flags; |
163 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); | |
8efc0c15 | 164 | } |
165 | ||
166 | /* Returns the remote protocol flags set earlier by the above function. */ | |
167 | ||
168 | unsigned int | |
169 | packet_get_protocol_flags() | |
170 | { | |
5260325f | 171 | return remote_protocol_flags; |
8efc0c15 | 172 | } |
173 | ||
5260325f | 174 | /* Starts packet compression from the next packet on in both directions. |
8efc0c15 | 175 | Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. */ |
176 | ||
177 | void | |
178 | packet_start_compression(int level) | |
179 | { | |
5260325f | 180 | if (packet_compression) |
181 | fatal("Compression already enabled."); | |
182 | packet_compression = 1; | |
183 | buffer_init(&compression_buffer); | |
184 | buffer_compress_init(level); | |
8efc0c15 | 185 | } |
186 | ||
187 | /* Encrypts the given number of bytes, copying from src to dest. | |
188 | bytes is known to be a multiple of 8. */ | |
189 | ||
190 | void | |
5260325f | 191 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
8efc0c15 | 192 | unsigned int bytes) |
193 | { | |
5260325f | 194 | cipher_encrypt(cc, dest, src, bytes); |
8efc0c15 | 195 | } |
196 | ||
197 | /* Decrypts the given number of bytes, copying from src to dest. | |
198 | bytes is known to be a multiple of 8. */ | |
199 | ||
200 | void | |
5260325f | 201 | packet_decrypt(CipherContext * cc, void *dest, void *src, |
8efc0c15 | 202 | unsigned int bytes) |
203 | { | |
5260325f | 204 | int i; |
205 | ||
206 | if ((bytes % 8) != 0) | |
207 | fatal("packet_decrypt: bad ciphertext length %d", bytes); | |
208 | ||
209 | /* Cryptographic attack detector for ssh - Modifications for packet.c | |
210 | (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) */ | |
211 | ||
212 | switch (cc->type) { | |
213 | case SSH_CIPHER_NONE: | |
214 | i = DEATTACK_OK; | |
215 | break; | |
216 | default: | |
217 | i = detect_attack(src, bytes, NULL); | |
218 | break; | |
219 | } | |
220 | ||
221 | if (i == DEATTACK_DETECTED) | |
222 | packet_disconnect("crc32 compensation attack: network attack detected"); | |
223 | ||
224 | cipher_decrypt(cc, dest, src, bytes); | |
8efc0c15 | 225 | } |
226 | ||
227 | /* Causes any further packets to be encrypted using the given key. The same | |
228 | key is used for both sending and reception. However, both directions | |
229 | are encrypted independently of each other. */ | |
230 | ||
231 | void | |
232 | packet_set_encryption_key(const unsigned char *key, unsigned int keylen, | |
4d195447 | 233 | int cipher) |
8efc0c15 | 234 | { |
5260325f | 235 | /* All other ciphers use the same key in both directions for now. */ |
236 | cipher_set_key(&receive_context, cipher, key, keylen, 0); | |
237 | cipher_set_key(&send_context, cipher, key, keylen, 1); | |
8efc0c15 | 238 | } |
239 | ||
240 | /* Starts constructing a packet to send. */ | |
241 | ||
242 | void | |
243 | packet_start(int type) | |
244 | { | |
5260325f | 245 | char buf[9]; |
8efc0c15 | 246 | |
5260325f | 247 | buffer_clear(&outgoing_packet); |
248 | memset(buf, 0, 8); | |
249 | buf[8] = type; | |
250 | buffer_append(&outgoing_packet, buf, 9); | |
8efc0c15 | 251 | } |
252 | ||
253 | /* Appends a character to the packet data. */ | |
254 | ||
255 | void | |
256 | packet_put_char(int value) | |
257 | { | |
5260325f | 258 | char ch = value; |
259 | buffer_append(&outgoing_packet, &ch, 1); | |
8efc0c15 | 260 | } |
261 | ||
262 | /* Appends an integer to the packet data. */ | |
263 | ||
264 | void | |
265 | packet_put_int(unsigned int value) | |
266 | { | |
5260325f | 267 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 268 | } |
269 | ||
270 | /* Appends a string to packet data. */ | |
271 | ||
272 | void | |
273 | packet_put_string(const char *buf, unsigned int len) | |
274 | { | |
5260325f | 275 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 276 | } |
277 | ||
278 | /* Appends an arbitrary precision integer to packet data. */ | |
279 | ||
280 | void | |
5260325f | 281 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 282 | { |
5260325f | 283 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 284 | } |
285 | ||
286 | /* Finalizes and sends the packet. If the encryption key has been set, | |
287 | encrypts the packet before sending. */ | |
5260325f | 288 | |
8efc0c15 | 289 | void |
290 | packet_send() | |
291 | { | |
5260325f | 292 | char buf[8], *cp; |
293 | int i, padding, len; | |
294 | unsigned int checksum; | |
295 | u_int32_t rand = 0; | |
296 | ||
297 | /* If using packet compression, compress the payload of the | |
298 | outgoing packet. */ | |
299 | if (packet_compression) { | |
300 | buffer_clear(&compression_buffer); | |
301 | /* Skip padding. */ | |
302 | buffer_consume(&outgoing_packet, 8); | |
303 | /* padding */ | |
304 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
305 | buffer_compress(&outgoing_packet, &compression_buffer); | |
306 | buffer_clear(&outgoing_packet); | |
307 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
308 | buffer_len(&compression_buffer)); | |
309 | } | |
310 | /* Compute packet length without padding (add checksum, remove padding). */ | |
311 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
312 | ||
313 | /* Insert padding. */ | |
314 | padding = 8 - len % 8; | |
315 | if (cipher_type != SSH_CIPHER_NONE) { | |
316 | cp = buffer_ptr(&outgoing_packet); | |
317 | for (i = 0; i < padding; i++) { | |
318 | if (i % 4 == 0) | |
319 | rand = arc4random(); | |
320 | cp[7 - i] = rand & 0xff; | |
321 | rand >>= 8; | |
322 | } | |
323 | } | |
324 | buffer_consume(&outgoing_packet, 8 - padding); | |
325 | ||
326 | /* Add check bytes. */ | |
327 | checksum = crc32((unsigned char *) buffer_ptr(&outgoing_packet), | |
328 | buffer_len(&outgoing_packet)); | |
329 | PUT_32BIT(buf, checksum); | |
330 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 331 | |
332 | #ifdef PACKET_DEBUG | |
5260325f | 333 | fprintf(stderr, "packet_send plain: "); |
334 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 335 | #endif |
336 | ||
5260325f | 337 | /* Append to output. */ |
338 | PUT_32BIT(buf, len); | |
339 | buffer_append(&output, buf, 4); | |
340 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
341 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
342 | buffer_len(&outgoing_packet)); | |
343 | ||
8efc0c15 | 344 | #ifdef PACKET_DEBUG |
5260325f | 345 | fprintf(stderr, "encrypted: "); |
346 | buffer_dump(&output); | |
8efc0c15 | 347 | #endif |
348 | ||
5260325f | 349 | buffer_clear(&outgoing_packet); |
8efc0c15 | 350 | |
5260325f | 351 | /* Note that the packet is now only buffered in output. It won\'t |
352 | be actually sent until packet_write_wait or packet_write_poll | |
353 | is called. */ | |
8efc0c15 | 354 | } |
355 | ||
356 | /* Waits until a packet has been received, and returns its type. Note that | |
357 | no other data is processed until this returns, so this function should | |
358 | not be used during the interactive session. */ | |
359 | ||
360 | int | |
361 | packet_read(int *payload_len_ptr) | |
362 | { | |
5260325f | 363 | int type, len; |
364 | fd_set set; | |
365 | char buf[8192]; | |
366 | ||
367 | /* Since we are blocking, ensure that all written packets have been sent. */ | |
368 | packet_write_wait(); | |
369 | ||
370 | /* Stay in the loop until we have received a complete packet. */ | |
371 | for (;;) { | |
372 | /* Try to read a packet from the buffer. */ | |
373 | type = packet_read_poll(payload_len_ptr); | |
374 | if (type == SSH_SMSG_SUCCESS | |
375 | || type == SSH_SMSG_FAILURE | |
376 | || type == SSH_CMSG_EOF | |
377 | || type == SSH_CMSG_EXIT_CONFIRMATION) | |
378 | packet_integrity_check(*payload_len_ptr, 0, type); | |
379 | /* If we got a packet, return it. */ | |
380 | if (type != SSH_MSG_NONE) | |
381 | return type; | |
382 | /* Otherwise, wait for some data to arrive, add it to the | |
383 | buffer, and try again. */ | |
384 | FD_ZERO(&set); | |
385 | FD_SET(connection_in, &set); | |
386 | /* Wait for some data to arrive. */ | |
387 | select(connection_in + 1, &set, NULL, NULL, NULL); | |
388 | /* Read data from the socket. */ | |
389 | len = read(connection_in, buf, sizeof(buf)); | |
390 | if (len == 0) | |
391 | fatal("Connection closed by %.200s", get_remote_ipaddr()); | |
392 | if (len < 0) | |
393 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
394 | /* Append it to the buffer. */ | |
395 | packet_process_incoming(buf, len); | |
396 | } | |
397 | /* NOTREACHED */ | |
8efc0c15 | 398 | } |
399 | ||
400 | /* Waits until a packet has been received, verifies that its type matches | |
401 | that given, and gives a fatal error and exits if there is a mismatch. */ | |
402 | ||
403 | void | |
404 | packet_read_expect(int *payload_len_ptr, int expected_type) | |
405 | { | |
5260325f | 406 | int type; |
8efc0c15 | 407 | |
5260325f | 408 | type = packet_read(payload_len_ptr); |
409 | if (type != expected_type) | |
410 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
411 | expected_type, type); | |
8efc0c15 | 412 | } |
413 | ||
414 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 415 | * packet_process_incoming. If so, reads the packet; otherwise returns |
416 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
417 | * | |
418 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
419 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
420 | * to higher levels. | |
421 | * | |
422 | * The returned payload_len does include space consumed by: | |
423 | * Packet length | |
424 | * Padding | |
425 | * Packet type | |
426 | * Check bytes | |
427 | */ | |
8efc0c15 | 428 | |
429 | int | |
430 | packet_read_poll(int *payload_len_ptr) | |
431 | { | |
5260325f | 432 | unsigned int len, padded_len; |
433 | unsigned char *ucp; | |
434 | char buf[8], *cp; | |
435 | unsigned int checksum, stored_checksum; | |
436 | ||
437 | restart: | |
438 | ||
439 | /* Check if input size is less than minimum packet size. */ | |
440 | if (buffer_len(&input) < 4 + 8) | |
441 | return SSH_MSG_NONE; | |
442 | /* Get length of incoming packet. */ | |
443 | ucp = (unsigned char *) buffer_ptr(&input); | |
444 | len = GET_32BIT(ucp); | |
445 | if (len < 1 + 2 + 2 || len > 256 * 1024) | |
446 | packet_disconnect("Bad packet length %d.", len); | |
447 | padded_len = (len + 8) & ~7; | |
448 | ||
449 | /* Check if the packet has been entirely received. */ | |
450 | if (buffer_len(&input) < 4 + padded_len) | |
451 | return SSH_MSG_NONE; | |
452 | ||
453 | /* The entire packet is in buffer. */ | |
454 | ||
455 | /* Consume packet length. */ | |
456 | buffer_consume(&input, 4); | |
457 | ||
458 | /* Copy data to incoming_packet. */ | |
459 | buffer_clear(&incoming_packet); | |
460 | buffer_append_space(&incoming_packet, &cp, padded_len); | |
461 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); | |
462 | buffer_consume(&input, padded_len); | |
8efc0c15 | 463 | |
464 | #ifdef PACKET_DEBUG | |
5260325f | 465 | fprintf(stderr, "read_poll plain: "); |
466 | buffer_dump(&incoming_packet); | |
8efc0c15 | 467 | #endif |
5260325f | 468 | |
469 | /* Compute packet checksum. */ | |
470 | checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet), | |
471 | buffer_len(&incoming_packet) - 4); | |
472 | ||
473 | /* Skip padding. */ | |
474 | buffer_consume(&incoming_packet, 8 - len % 8); | |
475 | ||
476 | /* Test check bytes. */ | |
477 | ||
478 | if (len != buffer_len(&incoming_packet)) | |
479 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", | |
480 | len, buffer_len(&incoming_packet)); | |
481 | ||
482 | ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4; | |
483 | stored_checksum = GET_32BIT(ucp); | |
484 | if (checksum != stored_checksum) | |
485 | packet_disconnect("Corrupted check bytes on input."); | |
486 | buffer_consume_end(&incoming_packet, 4); | |
487 | ||
488 | /* If using packet compression, decompress the packet. */ | |
489 | if (packet_compression) { | |
490 | buffer_clear(&compression_buffer); | |
491 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
492 | buffer_clear(&incoming_packet); | |
493 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
494 | buffer_len(&compression_buffer)); | |
495 | } | |
496 | /* Get packet type. */ | |
497 | buffer_get(&incoming_packet, &buf[0], 1); | |
498 | ||
499 | /* Return length of payload (without type field). */ | |
500 | *payload_len_ptr = buffer_len(&incoming_packet); | |
501 | ||
502 | /* Handle disconnect message. */ | |
503 | if ((unsigned char) buf[0] == SSH_MSG_DISCONNECT) | |
504 | fatal("Received disconnect: %.900s", packet_get_string(NULL)); | |
505 | ||
506 | /* Ignore ignore messages. */ | |
507 | if ((unsigned char) buf[0] == SSH_MSG_IGNORE) | |
508 | goto restart; | |
509 | ||
510 | /* Send debug messages as debugging output. */ | |
511 | if ((unsigned char) buf[0] == SSH_MSG_DEBUG) { | |
512 | debug("Remote: %.900s", packet_get_string(NULL)); | |
513 | goto restart; | |
514 | } | |
515 | /* Return type. */ | |
516 | return (unsigned char) buf[0]; | |
517 | } | |
518 | ||
8efc0c15 | 519 | /* Buffers the given amount of input characters. This is intended to be |
520 | used together with packet_read_poll. */ | |
521 | ||
522 | void | |
523 | packet_process_incoming(const char *buf, unsigned int len) | |
524 | { | |
5260325f | 525 | buffer_append(&input, buf, len); |
8efc0c15 | 526 | } |
527 | ||
528 | /* Returns a character from the packet. */ | |
529 | ||
530 | unsigned int | |
531 | packet_get_char() | |
532 | { | |
5260325f | 533 | char ch; |
534 | buffer_get(&incoming_packet, &ch, 1); | |
535 | return (unsigned char) ch; | |
8efc0c15 | 536 | } |
537 | ||
538 | /* Returns an integer from the packet data. */ | |
539 | ||
540 | unsigned int | |
541 | packet_get_int() | |
542 | { | |
5260325f | 543 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 544 | } |
545 | ||
546 | /* Returns an arbitrary precision integer from the packet data. The integer | |
547 | must have been initialized before this call. */ | |
548 | ||
549 | void | |
5260325f | 550 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
8efc0c15 | 551 | { |
5260325f | 552 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 553 | } |
554 | ||
555 | /* Returns a string from the packet data. The string is allocated using | |
556 | xmalloc; it is the responsibility of the calling program to free it when | |
557 | no longer needed. The length_ptr argument may be NULL, or point to an | |
558 | integer into which the length of the string is stored. */ | |
559 | ||
560 | char | |
5260325f | 561 | * |
562 | packet_get_string(unsigned int *length_ptr) | |
8efc0c15 | 563 | { |
5260325f | 564 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 565 | } |
566 | ||
567 | /* Sends a diagnostic message from the server to the client. This message | |
568 | can be sent at any time (but not while constructing another message). | |
569 | The message is printed immediately, but only if the client is being | |
570 | executed in verbose mode. These messages are primarily intended to | |
571 | ease debugging authentication problems. The length of the formatted | |
572 | message must not exceed 1024 bytes. This will automatically call | |
573 | packet_write_wait. */ | |
574 | ||
575 | void | |
5260325f | 576 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 577 | { |
5260325f | 578 | char buf[1024]; |
579 | va_list args; | |
580 | ||
581 | va_start(args, fmt); | |
582 | vsnprintf(buf, sizeof(buf), fmt, args); | |
583 | va_end(args); | |
584 | ||
585 | packet_start(SSH_MSG_DEBUG); | |
586 | packet_put_string(buf, strlen(buf)); | |
587 | packet_send(); | |
588 | packet_write_wait(); | |
8efc0c15 | 589 | } |
590 | ||
591 | /* Logs the error plus constructs and sends a disconnect | |
592 | packet, closes the connection, and exits. This function never returns. | |
593 | The error message should not contain a newline. The length of the | |
594 | formatted message must not exceed 1024 bytes. */ | |
595 | ||
596 | void | |
5260325f | 597 | packet_disconnect(const char *fmt,...) |
598 | { | |
599 | char buf[1024]; | |
600 | va_list args; | |
601 | static int disconnecting = 0; | |
602 | if (disconnecting) /* Guard against recursive invocations. */ | |
603 | fatal("packet_disconnect called recursively."); | |
604 | disconnecting = 1; | |
605 | ||
606 | /* Format the message. Note that the caller must make sure the | |
607 | message is of limited size. */ | |
608 | va_start(args, fmt); | |
609 | vsnprintf(buf, sizeof(buf), fmt, args); | |
610 | va_end(args); | |
611 | ||
612 | /* Send the disconnect message to the other side, and wait for it to get sent. */ | |
613 | packet_start(SSH_MSG_DISCONNECT); | |
614 | packet_put_string(buf, strlen(buf)); | |
615 | packet_send(); | |
616 | packet_write_wait(); | |
617 | ||
618 | /* Stop listening for connections. */ | |
619 | channel_stop_listening(); | |
620 | ||
621 | /* Close the connection. */ | |
622 | packet_close(); | |
623 | ||
624 | /* Display the error locally and exit. */ | |
625 | fatal("Disconnecting: %.100s", buf); | |
8efc0c15 | 626 | } |
627 | ||
628 | /* Checks if there is any buffered output, and tries to write some of the | |
629 | output. */ | |
630 | ||
631 | void | |
632 | packet_write_poll() | |
633 | { | |
5260325f | 634 | int len = buffer_len(&output); |
635 | if (len > 0) { | |
636 | len = write(connection_out, buffer_ptr(&output), len); | |
637 | if (len <= 0) { | |
638 | if (errno == EAGAIN) | |
639 | return; | |
640 | else | |
641 | fatal("Write failed: %.100s", strerror(errno)); | |
642 | } | |
643 | buffer_consume(&output, len); | |
644 | } | |
8efc0c15 | 645 | } |
646 | ||
647 | /* Calls packet_write_poll repeatedly until all pending output data has | |
648 | been written. */ | |
649 | ||
650 | void | |
651 | packet_write_wait() | |
652 | { | |
5260325f | 653 | packet_write_poll(); |
654 | while (packet_have_data_to_write()) { | |
655 | fd_set set; | |
656 | FD_ZERO(&set); | |
657 | FD_SET(connection_out, &set); | |
658 | select(connection_out + 1, NULL, &set, NULL, NULL); | |
659 | packet_write_poll(); | |
660 | } | |
8efc0c15 | 661 | } |
662 | ||
663 | /* Returns true if there is buffered data to write to the connection. */ | |
664 | ||
665 | int | |
666 | packet_have_data_to_write() | |
667 | { | |
5260325f | 668 | return buffer_len(&output) != 0; |
8efc0c15 | 669 | } |
670 | ||
671 | /* Returns true if there is not too much data to write to the connection. */ | |
672 | ||
673 | int | |
674 | packet_not_very_much_data_to_write() | |
675 | { | |
5260325f | 676 | if (interactive_mode) |
677 | return buffer_len(&output) < 16384; | |
678 | else | |
679 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 680 | } |
681 | ||
682 | /* Informs that the current session is interactive. Sets IP flags for that. */ | |
683 | ||
684 | void | |
685 | packet_set_interactive(int interactive, int keepalives) | |
686 | { | |
5260325f | 687 | int on = 1; |
688 | ||
689 | /* Record that we are in interactive mode. */ | |
690 | interactive_mode = interactive; | |
691 | ||
692 | /* Only set socket options if using a socket (as indicated by the | |
693 | descriptors being the same). */ | |
694 | if (connection_in != connection_out) | |
695 | return; | |
696 | ||
697 | if (keepalives) { | |
698 | /* Set keepalives if requested. */ | |
699 | if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, | |
700 | sizeof(on)) < 0) | |
701 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
702 | } | |
703 | if (interactive) { | |
704 | /* Set IP options for an interactive connection. Use | |
705 | IPTOS_LOWDELAY and TCP_NODELAY. */ | |
706 | int lowdelay = IPTOS_LOWDELAY; | |
707 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay, | |
708 | sizeof(lowdelay)) < 0) | |
709 | error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno)); | |
710 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, | |
711 | sizeof(on)) < 0) | |
712 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); | |
713 | } else { | |
714 | /* Set IP options for a non-interactive connection. Use | |
715 | IPTOS_THROUGHPUT. */ | |
716 | int throughput = IPTOS_THROUGHPUT; | |
717 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, | |
718 | sizeof(throughput)) < 0) | |
719 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); | |
720 | } | |
8efc0c15 | 721 | } |
722 | ||
723 | /* Returns true if the current connection is interactive. */ | |
724 | ||
725 | int | |
726 | packet_is_interactive() | |
727 | { | |
5260325f | 728 | return interactive_mode; |
8efc0c15 | 729 | } |
9d6b7add | 730 | |
731 | int | |
732 | packet_set_maxsize(int s) | |
733 | { | |
5260325f | 734 | static int called = 0; |
735 | if (called) { | |
736 | log("packet_set_maxsize: called twice: old %d new %d", max_packet_size, s); | |
737 | return -1; | |
738 | } | |
739 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
740 | log("packet_set_maxsize: bad size %d", s); | |
741 | return -1; | |
742 | } | |
743 | log("packet_set_maxsize: setting to %d", s); | |
744 | max_packet_size = s; | |
745 | return s; | |
9d6b7add | 746 | } |