Annotation of src/usr.bin/ssh/packet.c, Revision 1.15
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"
1.15 ! deraadt 18: RCSID("$Id: packet.c,v 1.14 1999/11/23 22:25:54 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:
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;
1.14 markus 48:
49: /* Encryption context for sending data. This is only used for encryption. */
1.1 deraadt 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:
1.12 markus 70: /* default maximum packet size */
71: int max_packet_size = 32768;
72:
1.1 deraadt 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:
1.2 provos 82: void
83: packet_set_connection(int fd_in, int fd_out)
1.1 deraadt 84: {
1.14 markus 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);
1.1 deraadt 99: }
100:
101: /* Sets the connection into non-blocking mode. */
102:
1.2 provos 103: void
104: packet_set_nonblocking()
1.1 deraadt 105: {
1.14 markus 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));
109:
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: }
1.1 deraadt 114: }
115:
116: /* Returns the socket used for reading. */
117:
1.2 provos 118: int
119: packet_get_connection_in()
1.1 deraadt 120: {
1.14 markus 121: return connection_in;
1.1 deraadt 122: }
123:
124: /* Returns the descriptor used for writing. */
125:
1.2 provos 126: int
127: packet_get_connection_out()
1.1 deraadt 128: {
1.14 markus 129: return connection_out;
1.1 deraadt 130: }
131:
132: /* Closes the connection and clears and frees internal data structures. */
133:
1.2 provos 134: void
135: packet_close()
1.1 deraadt 136: {
1.14 markus 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: }
1.1 deraadt 155: }
156:
157: /* Sets remote side protocol flags. */
158:
1.2 provos 159: void
160: packet_set_protocol_flags(unsigned int protocol_flags)
1.1 deraadt 161: {
1.14 markus 162: remote_protocol_flags = protocol_flags;
163: channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0);
1.1 deraadt 164: }
165:
166: /* Returns the remote protocol flags set earlier by the above function. */
167:
1.2 provos 168: unsigned int
169: packet_get_protocol_flags()
1.1 deraadt 170: {
1.14 markus 171: return remote_protocol_flags;
1.1 deraadt 172: }
173:
1.14 markus 174: /* Starts packet compression from the next packet on in both directions.
1.1 deraadt 175: Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. */
176:
1.2 provos 177: void
178: packet_start_compression(int level)
1.1 deraadt 179: {
1.14 markus 180: if (packet_compression)
181: fatal("Compression already enabled.");
182: packet_compression = 1;
183: buffer_init(&compression_buffer);
184: buffer_compress_init(level);
1.1 deraadt 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:
1.2 provos 190: void
1.14 markus 191: packet_encrypt(CipherContext * cc, void *dest, void *src,
1.2 provos 192: unsigned int bytes)
1.1 deraadt 193: {
1.14 markus 194: cipher_encrypt(cc, dest, src, bytes);
1.1 deraadt 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:
1.2 provos 200: void
1.14 markus 201: packet_decrypt(CipherContext * cc, void *dest, void *src,
1.2 provos 202: unsigned int bytes)
1.1 deraadt 203: {
1.14 markus 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);
1.1 deraadt 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:
1.2 provos 231: void
232: packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
1.11 markus 233: int cipher)
1.1 deraadt 234: {
1.14 markus 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);
1.1 deraadt 238: }
239:
240: /* Starts constructing a packet to send. */
241:
1.2 provos 242: void
243: packet_start(int type)
1.1 deraadt 244: {
1.14 markus 245: char buf[9];
1.1 deraadt 246:
1.14 markus 247: buffer_clear(&outgoing_packet);
248: memset(buf, 0, 8);
249: buf[8] = type;
250: buffer_append(&outgoing_packet, buf, 9);
1.1 deraadt 251: }
252:
253: /* Appends a character to the packet data. */
254:
1.2 provos 255: void
256: packet_put_char(int value)
1.1 deraadt 257: {
1.14 markus 258: char ch = value;
259: buffer_append(&outgoing_packet, &ch, 1);
1.1 deraadt 260: }
261:
262: /* Appends an integer to the packet data. */
263:
1.2 provos 264: void
265: packet_put_int(unsigned int value)
1.1 deraadt 266: {
1.14 markus 267: buffer_put_int(&outgoing_packet, value);
1.1 deraadt 268: }
269:
270: /* Appends a string to packet data. */
271:
1.2 provos 272: void
273: packet_put_string(const char *buf, unsigned int len)
1.1 deraadt 274: {
1.14 markus 275: buffer_put_string(&outgoing_packet, buf, len);
1.1 deraadt 276: }
277:
278: /* Appends an arbitrary precision integer to packet data. */
279:
1.2 provos 280: void
1.14 markus 281: packet_put_bignum(BIGNUM * value)
1.1 deraadt 282: {
1.14 markus 283: buffer_put_bignum(&outgoing_packet, value);
1.1 deraadt 284: }
285:
286: /* Finalizes and sends the packet. If the encryption key has been set,
287: encrypts the packet before sending. */
1.14 markus 288:
1.2 provos 289: void
290: packet_send()
1.1 deraadt 291: {
1.14 markus 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);
1.1 deraadt 331:
332: #ifdef PACKET_DEBUG
1.14 markus 333: fprintf(stderr, "packet_send plain: ");
334: buffer_dump(&outgoing_packet);
1.1 deraadt 335: #endif
336:
1.14 markus 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:
1.1 deraadt 344: #ifdef PACKET_DEBUG
1.14 markus 345: fprintf(stderr, "encrypted: ");
346: buffer_dump(&output);
1.1 deraadt 347: #endif
348:
1.14 markus 349: buffer_clear(&outgoing_packet);
1.1 deraadt 350:
1.14 markus 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. */
1.1 deraadt 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:
1.2 provos 360: int
361: packet_read(int *payload_len_ptr)
1.1 deraadt 362: {
1.14 markus 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 */
1.1 deraadt 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:
1.2 provos 403: void
404: packet_read_expect(int *payload_len_ptr, int expected_type)
1.1 deraadt 405: {
1.14 markus 406: int type;
1.1 deraadt 407:
1.14 markus 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);
1.1 deraadt 412: }
413:
414: /* Checks if a full packet is available in the data received so far via
1.14 markus 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: */
1.1 deraadt 428:
1.2 provos 429: int
430: packet_read_poll(int *payload_len_ptr)
1.1 deraadt 431: {
1.14 markus 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);
1.1 deraadt 463:
464: #ifdef PACKET_DEBUG
1.14 markus 465: fprintf(stderr, "read_poll plain: ");
466: buffer_dump(&incoming_packet);
1.1 deraadt 467: #endif
468:
1.14 markus 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];
1.1 deraadt 517: }
1.14 markus 518:
1.1 deraadt 519: /* Buffers the given amount of input characters. This is intended to be
520: used together with packet_read_poll. */
521:
1.2 provos 522: void
523: packet_process_incoming(const char *buf, unsigned int len)
1.1 deraadt 524: {
1.14 markus 525: buffer_append(&input, buf, len);
1.1 deraadt 526: }
527:
528: /* Returns a character from the packet. */
529:
1.2 provos 530: unsigned int
531: packet_get_char()
1.1 deraadt 532: {
1.14 markus 533: char ch;
534: buffer_get(&incoming_packet, &ch, 1);
535: return (unsigned char) ch;
1.1 deraadt 536: }
537:
538: /* Returns an integer from the packet data. */
539:
1.2 provos 540: unsigned int
541: packet_get_int()
1.1 deraadt 542: {
1.14 markus 543: return buffer_get_int(&incoming_packet);
1.1 deraadt 544: }
545:
546: /* Returns an arbitrary precision integer from the packet data. The integer
547: must have been initialized before this call. */
548:
1.2 provos 549: void
1.14 markus 550: packet_get_bignum(BIGNUM * value, int *length_ptr)
1.1 deraadt 551: {
1.14 markus 552: *length_ptr = buffer_get_bignum(&incoming_packet, value);
1.1 deraadt 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:
1.2 provos 560: char
1.14 markus 561: *
562: packet_get_string(unsigned int *length_ptr)
1.1 deraadt 563: {
1.14 markus 564: return buffer_get_string(&incoming_packet, length_ptr);
1.1 deraadt 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:
1.2 provos 575: void
1.14 markus 576: packet_send_debug(const char *fmt,...)
1.1 deraadt 577: {
1.14 markus 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();
1.1 deraadt 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:
1.2 provos 596: void
1.14 markus 597: packet_disconnect(const char *fmt,...)
1.1 deraadt 598: {
1.14 markus 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();
1.1 deraadt 623:
1.14 markus 624: /* Display the error locally and exit. */
625: fatal("Disconnecting: %.100s", buf);
1.1 deraadt 626: }
627:
628: /* Checks if there is any buffered output, and tries to write some of the
629: output. */
630:
1.2 provos 631: void
632: packet_write_poll()
1.1 deraadt 633: {
1.14 markus 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: }
1.1 deraadt 645: }
646:
647: /* Calls packet_write_poll repeatedly until all pending output data has
648: been written. */
649:
1.2 provos 650: void
651: packet_write_wait()
1.1 deraadt 652: {
1.14 markus 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: }
1.1 deraadt 661: }
662:
663: /* Returns true if there is buffered data to write to the connection. */
664:
1.2 provos 665: int
666: packet_have_data_to_write()
1.1 deraadt 667: {
1.14 markus 668: return buffer_len(&output) != 0;
1.1 deraadt 669: }
670:
671: /* Returns true if there is not too much data to write to the connection. */
672:
1.2 provos 673: int
674: packet_not_very_much_data_to_write()
1.1 deraadt 675: {
1.14 markus 676: if (interactive_mode)
677: return buffer_len(&output) < 16384;
678: else
679: return buffer_len(&output) < 128 * 1024;
1.1 deraadt 680: }
681:
682: /* Informs that the current session is interactive. Sets IP flags for that. */
683:
1.2 provos 684: void
685: packet_set_interactive(int interactive, int keepalives)
1.1 deraadt 686: {
1.14 markus 687: int on = 1;
1.1 deraadt 688:
1.14 markus 689: /* Record that we are in interactive mode. */
690: interactive_mode = interactive;
1.1 deraadt 691:
1.14 markus 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: }
1.1 deraadt 721: }
722:
723: /* Returns true if the current connection is interactive. */
724:
1.2 provos 725: int
726: packet_is_interactive()
1.1 deraadt 727: {
1.14 markus 728: return interactive_mode;
1.12 markus 729: }
730:
731: int
732: packet_set_maxsize(int s)
733: {
1.14 markus 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;
1.1 deraadt 746: }
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