Annotation of src/usr.bin/ssh/packet.c, Revision 1.18
1.1 deraadt 1: /*
1.15 deraadt 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: */
1.1 deraadt 16:
17: #include "includes.h"
1.18 ! markus 18: RCSID("$Id: packet.c,v 1.17 1999/12/02 20:16:34 markus Exp $");
1.1 deraadt 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"
1.9 dugsong 30: #include "deattack.h"
1.1 deraadt 31:
1.16 markus 32: /*
33: * This variable contains the file descriptors used for communicating with
34: * the other side. connection_in is used for reading; connection_out for
35: * writing. These can be the same descriptor, in which case it is assumed to
36: * be a socket.
37: */
1.1 deraadt 38: static int connection_in = -1;
39: static int connection_out = -1;
40:
1.16 markus 41: /*
42: * Cipher type. This value is only used to determine whether to pad the
43: * packets with zeroes or random data.
44: */
1.1 deraadt 45: static int cipher_type = SSH_CIPHER_NONE;
46:
47: /* Protocol flags for the remote side. */
48: static unsigned int remote_protocol_flags = 0;
49:
50: /* Encryption context for receiving data. This is only used for decryption. */
51: static CipherContext receive_context;
1.14 markus 52:
53: /* Encryption context for sending data. This is only used for encryption. */
1.1 deraadt 54: static CipherContext send_context;
55:
56: /* Buffer for raw input data from the socket. */
57: static Buffer input;
58:
59: /* Buffer for raw output data going to the socket. */
60: static Buffer output;
61:
62: /* Buffer for the partial outgoing packet being constructed. */
63: static Buffer outgoing_packet;
64:
65: /* Buffer for the incoming packet currently being processed. */
66: static Buffer incoming_packet;
67:
68: /* Scratch buffer for packet compression/decompression. */
69: static Buffer compression_buffer;
70:
71: /* Flag indicating whether packet compression/decompression is enabled. */
72: static int packet_compression = 0;
73:
1.12 markus 74: /* default maximum packet size */
75: int max_packet_size = 32768;
76:
1.1 deraadt 77: /* Flag indicating whether this module has been initialized. */
78: static int initialized = 0;
79:
80: /* Set to true if the connection is interactive. */
81: static int interactive_mode = 0;
82:
1.16 markus 83: /*
84: * Sets the descriptors used for communication. Disables encryption until
85: * packet_set_encryption_key is called.
86: */
1.1 deraadt 87:
1.2 provos 88: void
89: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 90: {
1.14 markus 91: connection_in = fd_in;
92: connection_out = fd_out;
93: cipher_type = SSH_CIPHER_NONE;
94: cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0, 1);
95: cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0, 0);
96: if (!initialized) {
97: initialized = 1;
98: buffer_init(&input);
99: buffer_init(&output);
100: buffer_init(&outgoing_packet);
101: buffer_init(&incoming_packet);
102: }
103: /* Kludge: arrange the close function to be called from fatal(). */
104: fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
1.1 deraadt 105: }
106:
107: /* Sets the connection into non-blocking mode. */
108:
1.2 provos 109: void
110: packet_set_nonblocking()
1.1 deraadt 111: {
1.14 markus 112: /* Set the socket into non-blocking mode. */
113: if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0)
114: error("fcntl O_NONBLOCK: %.100s", strerror(errno));
115:
116: if (connection_out != connection_in) {
117: if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0)
118: error("fcntl O_NONBLOCK: %.100s", strerror(errno));
119: }
1.1 deraadt 120: }
121:
122: /* Returns the socket used for reading. */
123:
1.2 provos 124: int
125: packet_get_connection_in()
1.1 deraadt 126: {
1.14 markus 127: return connection_in;
1.1 deraadt 128: }
129:
130: /* Returns the descriptor used for writing. */
131:
1.2 provos 132: int
133: packet_get_connection_out()
1.1 deraadt 134: {
1.14 markus 135: return connection_out;
1.1 deraadt 136: }
137:
138: /* Closes the connection and clears and frees internal data structures. */
139:
1.2 provos 140: void
141: packet_close()
1.1 deraadt 142: {
1.14 markus 143: if (!initialized)
144: return;
145: initialized = 0;
146: if (connection_in == connection_out) {
147: shutdown(connection_out, SHUT_RDWR);
148: close(connection_out);
149: } else {
150: close(connection_in);
151: close(connection_out);
152: }
153: buffer_free(&input);
154: buffer_free(&output);
155: buffer_free(&outgoing_packet);
156: buffer_free(&incoming_packet);
157: if (packet_compression) {
158: buffer_free(&compression_buffer);
159: buffer_compress_uninit();
160: }
1.1 deraadt 161: }
162:
163: /* Sets remote side protocol flags. */
164:
1.2 provos 165: void
166: packet_set_protocol_flags(unsigned int protocol_flags)
1.1 deraadt 167: {
1.14 markus 168: remote_protocol_flags = protocol_flags;
169: channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0);
1.1 deraadt 170: }
171:
172: /* Returns the remote protocol flags set earlier by the above function. */
173:
1.2 provos 174: unsigned int
175: packet_get_protocol_flags()
1.1 deraadt 176: {
1.14 markus 177: return remote_protocol_flags;
1.1 deraadt 178: }
179:
1.16 markus 180: /*
181: * Starts packet compression from the next packet on in both directions.
182: * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
183: */
1.1 deraadt 184:
1.2 provos 185: void
186: packet_start_compression(int level)
1.1 deraadt 187: {
1.14 markus 188: if (packet_compression)
189: fatal("Compression already enabled.");
190: packet_compression = 1;
191: buffer_init(&compression_buffer);
192: buffer_compress_init(level);
1.1 deraadt 193: }
194:
1.16 markus 195: /*
196: * Encrypts the given number of bytes, copying from src to dest. bytes is
197: * known to be a multiple of 8.
198: */
1.1 deraadt 199:
1.2 provos 200: void
1.14 markus 201: packet_encrypt(CipherContext * cc, void *dest, void *src,
1.2 provos 202: unsigned int bytes)
1.1 deraadt 203: {
1.14 markus 204: cipher_encrypt(cc, dest, src, bytes);
1.1 deraadt 205: }
206:
1.16 markus 207: /*
208: * Decrypts the given number of bytes, copying from src to dest. bytes is
209: * known to be a multiple of 8.
210: */
1.1 deraadt 211:
1.2 provos 212: void
1.14 markus 213: packet_decrypt(CipherContext * cc, void *dest, void *src,
1.2 provos 214: unsigned int bytes)
1.1 deraadt 215: {
1.14 markus 216: int i;
217:
218: if ((bytes % 8) != 0)
219: fatal("packet_decrypt: bad ciphertext length %d", bytes);
220:
1.16 markus 221: /*
222: * Cryptographic attack detector for ssh - Modifications for packet.c
223: * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com)
224: */
1.14 markus 225:
226: switch (cc->type) {
227: case SSH_CIPHER_NONE:
228: i = DEATTACK_OK;
229: break;
230: default:
231: i = detect_attack(src, bytes, NULL);
232: break;
233: }
234:
235: if (i == DEATTACK_DETECTED)
236: packet_disconnect("crc32 compensation attack: network attack detected");
237:
238: cipher_decrypt(cc, dest, src, bytes);
1.1 deraadt 239: }
240:
1.16 markus 241: /*
242: * Causes any further packets to be encrypted using the given key. The same
243: * key is used for both sending and reception. However, both directions are
244: * encrypted independently of each other.
245: */
1.1 deraadt 246:
1.2 provos 247: void
248: packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
1.11 markus 249: int cipher)
1.1 deraadt 250: {
1.14 markus 251: /* All other ciphers use the same key in both directions for now. */
252: cipher_set_key(&receive_context, cipher, key, keylen, 0);
253: cipher_set_key(&send_context, cipher, key, keylen, 1);
1.1 deraadt 254: }
255:
256: /* Starts constructing a packet to send. */
257:
1.2 provos 258: void
259: packet_start(int type)
1.1 deraadt 260: {
1.14 markus 261: char buf[9];
1.1 deraadt 262:
1.14 markus 263: buffer_clear(&outgoing_packet);
264: memset(buf, 0, 8);
265: buf[8] = type;
266: buffer_append(&outgoing_packet, buf, 9);
1.1 deraadt 267: }
268:
269: /* Appends a character to the packet data. */
270:
1.2 provos 271: void
272: packet_put_char(int value)
1.1 deraadt 273: {
1.14 markus 274: char ch = value;
275: buffer_append(&outgoing_packet, &ch, 1);
1.1 deraadt 276: }
277:
278: /* Appends an integer to the packet data. */
279:
1.2 provos 280: void
281: packet_put_int(unsigned int value)
1.1 deraadt 282: {
1.14 markus 283: buffer_put_int(&outgoing_packet, value);
1.1 deraadt 284: }
285:
286: /* Appends a string to packet data. */
287:
1.2 provos 288: void
289: packet_put_string(const char *buf, unsigned int len)
1.1 deraadt 290: {
1.14 markus 291: buffer_put_string(&outgoing_packet, buf, len);
1.1 deraadt 292: }
293:
294: /* Appends an arbitrary precision integer to packet data. */
295:
1.2 provos 296: void
1.14 markus 297: packet_put_bignum(BIGNUM * value)
1.1 deraadt 298: {
1.14 markus 299: buffer_put_bignum(&outgoing_packet, value);
1.1 deraadt 300: }
301:
1.16 markus 302: /*
303: * Finalizes and sends the packet. If the encryption key has been set,
304: * encrypts the packet before sending.
305: */
1.14 markus 306:
1.2 provos 307: void
308: packet_send()
1.1 deraadt 309: {
1.14 markus 310: char buf[8], *cp;
311: int i, padding, len;
312: unsigned int checksum;
313: u_int32_t rand = 0;
314:
1.16 markus 315: /*
316: * If using packet compression, compress the payload of the outgoing
317: * packet.
318: */
1.14 markus 319: if (packet_compression) {
320: buffer_clear(&compression_buffer);
321: /* Skip padding. */
322: buffer_consume(&outgoing_packet, 8);
323: /* padding */
324: buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8);
325: buffer_compress(&outgoing_packet, &compression_buffer);
326: buffer_clear(&outgoing_packet);
327: buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer),
328: buffer_len(&compression_buffer));
329: }
330: /* Compute packet length without padding (add checksum, remove padding). */
331: len = buffer_len(&outgoing_packet) + 4 - 8;
332:
333: /* Insert padding. */
334: padding = 8 - len % 8;
335: if (cipher_type != SSH_CIPHER_NONE) {
336: cp = buffer_ptr(&outgoing_packet);
337: for (i = 0; i < padding; i++) {
338: if (i % 4 == 0)
339: rand = arc4random();
340: cp[7 - i] = rand & 0xff;
341: rand >>= 8;
342: }
343: }
344: buffer_consume(&outgoing_packet, 8 - padding);
345:
346: /* Add check bytes. */
347: checksum = crc32((unsigned char *) buffer_ptr(&outgoing_packet),
348: buffer_len(&outgoing_packet));
349: PUT_32BIT(buf, checksum);
350: buffer_append(&outgoing_packet, buf, 4);
1.1 deraadt 351:
352: #ifdef PACKET_DEBUG
1.14 markus 353: fprintf(stderr, "packet_send plain: ");
354: buffer_dump(&outgoing_packet);
1.1 deraadt 355: #endif
356:
1.14 markus 357: /* Append to output. */
358: PUT_32BIT(buf, len);
359: buffer_append(&output, buf, 4);
360: buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
361: packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
362: buffer_len(&outgoing_packet));
363:
1.1 deraadt 364: #ifdef PACKET_DEBUG
1.14 markus 365: fprintf(stderr, "encrypted: ");
366: buffer_dump(&output);
1.1 deraadt 367: #endif
368:
1.14 markus 369: buffer_clear(&outgoing_packet);
1.1 deraadt 370:
1.16 markus 371: /*
372: * Note that the packet is now only buffered in output. It won\'t be
373: * actually sent until packet_write_wait or packet_write_poll is
374: * called.
375: */
1.1 deraadt 376: }
377:
1.16 markus 378: /*
379: * Waits until a packet has been received, and returns its type. Note that
380: * no other data is processed until this returns, so this function should not
381: * be used during the interactive session.
382: */
1.1 deraadt 383:
1.2 provos 384: int
385: packet_read(int *payload_len_ptr)
1.1 deraadt 386: {
1.14 markus 387: int type, len;
388: fd_set set;
389: char buf[8192];
390:
391: /* Since we are blocking, ensure that all written packets have been sent. */
392: packet_write_wait();
393:
394: /* Stay in the loop until we have received a complete packet. */
395: for (;;) {
396: /* Try to read a packet from the buffer. */
397: type = packet_read_poll(payload_len_ptr);
398: if (type == SSH_SMSG_SUCCESS
399: || type == SSH_SMSG_FAILURE
400: || type == SSH_CMSG_EOF
401: || type == SSH_CMSG_EXIT_CONFIRMATION)
402: packet_integrity_check(*payload_len_ptr, 0, type);
403: /* If we got a packet, return it. */
404: if (type != SSH_MSG_NONE)
405: return type;
1.16 markus 406: /*
407: * Otherwise, wait for some data to arrive, add it to the
408: * buffer, and try again.
409: */
1.14 markus 410: FD_ZERO(&set);
411: FD_SET(connection_in, &set);
1.16 markus 412:
1.14 markus 413: /* Wait for some data to arrive. */
414: select(connection_in + 1, &set, NULL, NULL, NULL);
1.16 markus 415:
1.14 markus 416: /* Read data from the socket. */
417: len = read(connection_in, buf, sizeof(buf));
1.18 ! markus 418: if (len == 0) {
! 419: log("Connection closed by %.200s", get_remote_ipaddr());
! 420: fatal_cleanup();
! 421: }
1.14 markus 422: if (len < 0)
423: fatal("Read from socket failed: %.100s", strerror(errno));
424: /* Append it to the buffer. */
425: packet_process_incoming(buf, len);
426: }
427: /* NOTREACHED */
1.1 deraadt 428: }
429:
1.16 markus 430: /*
431: * Waits until a packet has been received, verifies that its type matches
432: * that given, and gives a fatal error and exits if there is a mismatch.
433: */
1.1 deraadt 434:
1.2 provos 435: void
436: packet_read_expect(int *payload_len_ptr, int expected_type)
1.1 deraadt 437: {
1.14 markus 438: int type;
1.1 deraadt 439:
1.14 markus 440: type = packet_read(payload_len_ptr);
441: if (type != expected_type)
442: packet_disconnect("Protocol error: expected packet type %d, got %d",
443: expected_type, type);
1.1 deraadt 444: }
445:
446: /* Checks if a full packet is available in the data received so far via
1.14 markus 447: * packet_process_incoming. If so, reads the packet; otherwise returns
448: * SSH_MSG_NONE. This does not wait for data from the connection.
449: *
450: * SSH_MSG_DISCONNECT is handled specially here. Also,
451: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
452: * to higher levels.
453: *
454: * The returned payload_len does include space consumed by:
455: * Packet length
456: * Padding
457: * Packet type
458: * Check bytes
459: */
1.1 deraadt 460:
1.2 provos 461: int
462: packet_read_poll(int *payload_len_ptr)
1.1 deraadt 463: {
1.14 markus 464: unsigned int len, padded_len;
465: unsigned char *ucp;
466: char buf[8], *cp;
467: unsigned int checksum, stored_checksum;
468:
469: restart:
470:
471: /* Check if input size is less than minimum packet size. */
472: if (buffer_len(&input) < 4 + 8)
473: return SSH_MSG_NONE;
474: /* Get length of incoming packet. */
475: ucp = (unsigned char *) buffer_ptr(&input);
476: len = GET_32BIT(ucp);
477: if (len < 1 + 2 + 2 || len > 256 * 1024)
478: packet_disconnect("Bad packet length %d.", len);
479: padded_len = (len + 8) & ~7;
480:
481: /* Check if the packet has been entirely received. */
482: if (buffer_len(&input) < 4 + padded_len)
483: return SSH_MSG_NONE;
484:
485: /* The entire packet is in buffer. */
486:
487: /* Consume packet length. */
488: buffer_consume(&input, 4);
489:
490: /* Copy data to incoming_packet. */
491: buffer_clear(&incoming_packet);
492: buffer_append_space(&incoming_packet, &cp, padded_len);
493: packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
494: buffer_consume(&input, padded_len);
1.1 deraadt 495:
496: #ifdef PACKET_DEBUG
1.14 markus 497: fprintf(stderr, "read_poll plain: ");
498: buffer_dump(&incoming_packet);
1.1 deraadt 499: #endif
500:
1.14 markus 501: /* Compute packet checksum. */
502: checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet),
503: buffer_len(&incoming_packet) - 4);
504:
505: /* Skip padding. */
506: buffer_consume(&incoming_packet, 8 - len % 8);
507:
508: /* Test check bytes. */
509:
510: if (len != buffer_len(&incoming_packet))
511: packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
512: len, buffer_len(&incoming_packet));
513:
514: ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4;
515: stored_checksum = GET_32BIT(ucp);
516: if (checksum != stored_checksum)
517: packet_disconnect("Corrupted check bytes on input.");
518: buffer_consume_end(&incoming_packet, 4);
519:
520: /* If using packet compression, decompress the packet. */
521: if (packet_compression) {
522: buffer_clear(&compression_buffer);
523: buffer_uncompress(&incoming_packet, &compression_buffer);
524: buffer_clear(&incoming_packet);
525: buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
526: buffer_len(&compression_buffer));
527: }
528: /* Get packet type. */
529: buffer_get(&incoming_packet, &buf[0], 1);
530:
531: /* Return length of payload (without type field). */
532: *payload_len_ptr = buffer_len(&incoming_packet);
533:
534: /* Handle disconnect message. */
1.17 markus 535: if ((unsigned char) buf[0] == SSH_MSG_DISCONNECT) {
536: log("Received disconnect: %.900s", packet_get_string(NULL));
537: fatal_cleanup();
538: }
1.14 markus 539:
540: /* Ignore ignore messages. */
541: if ((unsigned char) buf[0] == SSH_MSG_IGNORE)
542: goto restart;
543:
544: /* Send debug messages as debugging output. */
545: if ((unsigned char) buf[0] == SSH_MSG_DEBUG) {
546: debug("Remote: %.900s", packet_get_string(NULL));
547: goto restart;
548: }
549: /* Return type. */
550: return (unsigned char) buf[0];
1.1 deraadt 551: }
1.14 markus 552:
1.16 markus 553: /*
554: * Buffers the given amount of input characters. This is intended to be used
555: * together with packet_read_poll.
556: */
1.1 deraadt 557:
1.2 provos 558: void
559: packet_process_incoming(const char *buf, unsigned int len)
1.1 deraadt 560: {
1.14 markus 561: buffer_append(&input, buf, len);
1.1 deraadt 562: }
563:
564: /* Returns a character from the packet. */
565:
1.2 provos 566: unsigned int
567: packet_get_char()
1.1 deraadt 568: {
1.14 markus 569: char ch;
570: buffer_get(&incoming_packet, &ch, 1);
571: return (unsigned char) ch;
1.1 deraadt 572: }
573:
574: /* Returns an integer from the packet data. */
575:
1.2 provos 576: unsigned int
577: packet_get_int()
1.1 deraadt 578: {
1.14 markus 579: return buffer_get_int(&incoming_packet);
1.1 deraadt 580: }
581:
1.16 markus 582: /*
583: * Returns an arbitrary precision integer from the packet data. The integer
584: * must have been initialized before this call.
585: */
1.1 deraadt 586:
1.2 provos 587: void
1.14 markus 588: packet_get_bignum(BIGNUM * value, int *length_ptr)
1.1 deraadt 589: {
1.14 markus 590: *length_ptr = buffer_get_bignum(&incoming_packet, value);
1.1 deraadt 591: }
592:
1.16 markus 593: /*
594: * Returns a string from the packet data. The string is allocated using
595: * xmalloc; it is the responsibility of the calling program to free it when
596: * no longer needed. The length_ptr argument may be NULL, or point to an
597: * integer into which the length of the string is stored.
598: */
1.1 deraadt 599:
1.16 markus 600: char *
1.14 markus 601: packet_get_string(unsigned int *length_ptr)
1.1 deraadt 602: {
1.14 markus 603: return buffer_get_string(&incoming_packet, length_ptr);
1.1 deraadt 604: }
605:
1.16 markus 606: /*
607: * Sends a diagnostic message from the server to the client. This message
608: * can be sent at any time (but not while constructing another message). The
609: * message is printed immediately, but only if the client is being executed
610: * in verbose mode. These messages are primarily intended to ease debugging
611: * authentication problems. The length of the formatted message must not
612: * exceed 1024 bytes. This will automatically call packet_write_wait.
613: */
1.1 deraadt 614:
1.2 provos 615: void
1.14 markus 616: packet_send_debug(const char *fmt,...)
1.1 deraadt 617: {
1.14 markus 618: char buf[1024];
619: va_list args;
620:
621: va_start(args, fmt);
622: vsnprintf(buf, sizeof(buf), fmt, args);
623: va_end(args);
624:
625: packet_start(SSH_MSG_DEBUG);
626: packet_put_string(buf, strlen(buf));
627: packet_send();
628: packet_write_wait();
1.1 deraadt 629: }
630:
1.16 markus 631: /*
632: * Logs the error plus constructs and sends a disconnect packet, closes the
633: * connection, and exits. This function never returns. The error message
634: * should not contain a newline. The length of the formatted message must
635: * not exceed 1024 bytes.
636: */
1.1 deraadt 637:
1.2 provos 638: void
1.14 markus 639: packet_disconnect(const char *fmt,...)
1.1 deraadt 640: {
1.14 markus 641: char buf[1024];
642: va_list args;
643: static int disconnecting = 0;
644: if (disconnecting) /* Guard against recursive invocations. */
645: fatal("packet_disconnect called recursively.");
646: disconnecting = 1;
647:
1.16 markus 648: /*
649: * Format the message. Note that the caller must make sure the
650: * message is of limited size.
651: */
1.14 markus 652: va_start(args, fmt);
653: vsnprintf(buf, sizeof(buf), fmt, args);
654: va_end(args);
655:
656: /* Send the disconnect message to the other side, and wait for it to get sent. */
657: packet_start(SSH_MSG_DISCONNECT);
658: packet_put_string(buf, strlen(buf));
659: packet_send();
660: packet_write_wait();
661:
662: /* Stop listening for connections. */
663: channel_stop_listening();
664:
665: /* Close the connection. */
666: packet_close();
1.1 deraadt 667:
1.14 markus 668: /* Display the error locally and exit. */
1.17 markus 669: log("Disconnecting: %.100s", buf);
670: fatal_cleanup();
1.1 deraadt 671: }
672:
1.16 markus 673: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 674:
1.2 provos 675: void
676: packet_write_poll()
1.1 deraadt 677: {
1.14 markus 678: int len = buffer_len(&output);
679: if (len > 0) {
680: len = write(connection_out, buffer_ptr(&output), len);
681: if (len <= 0) {
682: if (errno == EAGAIN)
683: return;
684: else
685: fatal("Write failed: %.100s", strerror(errno));
686: }
687: buffer_consume(&output, len);
688: }
1.1 deraadt 689: }
690:
1.16 markus 691: /*
692: * Calls packet_write_poll repeatedly until all pending output data has been
693: * written.
694: */
1.1 deraadt 695:
1.2 provos 696: void
697: packet_write_wait()
1.1 deraadt 698: {
1.14 markus 699: packet_write_poll();
700: while (packet_have_data_to_write()) {
701: fd_set set;
702: FD_ZERO(&set);
703: FD_SET(connection_out, &set);
704: select(connection_out + 1, NULL, &set, NULL, NULL);
705: packet_write_poll();
706: }
1.1 deraadt 707: }
708:
709: /* Returns true if there is buffered data to write to the connection. */
710:
1.2 provos 711: int
712: packet_have_data_to_write()
1.1 deraadt 713: {
1.14 markus 714: return buffer_len(&output) != 0;
1.1 deraadt 715: }
716:
717: /* Returns true if there is not too much data to write to the connection. */
718:
1.2 provos 719: int
720: packet_not_very_much_data_to_write()
1.1 deraadt 721: {
1.14 markus 722: if (interactive_mode)
723: return buffer_len(&output) < 16384;
724: else
725: return buffer_len(&output) < 128 * 1024;
1.1 deraadt 726: }
727:
728: /* Informs that the current session is interactive. Sets IP flags for that. */
729:
1.2 provos 730: void
731: packet_set_interactive(int interactive, int keepalives)
1.1 deraadt 732: {
1.14 markus 733: int on = 1;
1.1 deraadt 734:
1.14 markus 735: /* Record that we are in interactive mode. */
736: interactive_mode = interactive;
1.1 deraadt 737:
1.16 markus 738: /*
739: * Only set socket options if using a socket (as indicated by the
740: * descriptors being the same).
741: */
1.14 markus 742: if (connection_in != connection_out)
743: return;
744:
745: if (keepalives) {
746: /* Set keepalives if requested. */
747: if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on,
748: sizeof(on)) < 0)
749: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
750: }
751: if (interactive) {
1.16 markus 752: /*
753: * Set IP options for an interactive connection. Use
754: * IPTOS_LOWDELAY and TCP_NODELAY.
755: */
1.14 markus 756: int lowdelay = IPTOS_LOWDELAY;
757: if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay,
758: sizeof(lowdelay)) < 0)
759: error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno));
760: if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on,
761: sizeof(on)) < 0)
762: error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
763: } else {
1.16 markus 764: /*
765: * Set IP options for a non-interactive connection. Use
766: * IPTOS_THROUGHPUT.
767: */
1.14 markus 768: int throughput = IPTOS_THROUGHPUT;
769: if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput,
770: sizeof(throughput)) < 0)
771: error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
772: }
1.1 deraadt 773: }
774:
775: /* Returns true if the current connection is interactive. */
776:
1.2 provos 777: int
778: packet_is_interactive()
1.1 deraadt 779: {
1.14 markus 780: return interactive_mode;
1.12 markus 781: }
782:
783: int
784: packet_set_maxsize(int s)
785: {
1.14 markus 786: static int called = 0;
787: if (called) {
788: log("packet_set_maxsize: called twice: old %d new %d", max_packet_size, s);
789: return -1;
790: }
791: if (s < 4 * 1024 || s > 1024 * 1024) {
792: log("packet_set_maxsize: bad size %d", s);
793: return -1;
794: }
795: log("packet_set_maxsize: setting to %d", s);
796: max_packet_size = s;
797: return s;
1.1 deraadt 798: }
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