Annotation of src/usr.bin/ssh/packet.c, Revision 1.17
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"
1.17 ! markus 18: RCSID("$Id: packet.c,v 1.16 1999/11/24 19:53:48 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));
418: if (len == 0)
419: fatal("Connection closed by %.200s", get_remote_ipaddr());
420: if (len < 0)
421: fatal("Read from socket failed: %.100s", strerror(errno));
422: /* Append it to the buffer. */
423: packet_process_incoming(buf, len);
424: }
425: /* NOTREACHED */
1.1 deraadt 426: }
427:
1.16 markus 428: /*
429: * Waits until a packet has been received, verifies that its type matches
430: * that given, and gives a fatal error and exits if there is a mismatch.
431: */
1.1 deraadt 432:
1.2 provos 433: void
434: packet_read_expect(int *payload_len_ptr, int expected_type)
1.1 deraadt 435: {
1.14 markus 436: int type;
1.1 deraadt 437:
1.14 markus 438: type = packet_read(payload_len_ptr);
439: if (type != expected_type)
440: packet_disconnect("Protocol error: expected packet type %d, got %d",
441: expected_type, type);
1.1 deraadt 442: }
443:
444: /* Checks if a full packet is available in the data received so far via
1.14 markus 445: * packet_process_incoming. If so, reads the packet; otherwise returns
446: * SSH_MSG_NONE. This does not wait for data from the connection.
447: *
448: * SSH_MSG_DISCONNECT is handled specially here. Also,
449: * SSH_MSG_IGNORE messages are skipped by this function and are never returned
450: * to higher levels.
451: *
452: * The returned payload_len does include space consumed by:
453: * Packet length
454: * Padding
455: * Packet type
456: * Check bytes
457: */
1.1 deraadt 458:
1.2 provos 459: int
460: packet_read_poll(int *payload_len_ptr)
1.1 deraadt 461: {
1.14 markus 462: unsigned int len, padded_len;
463: unsigned char *ucp;
464: char buf[8], *cp;
465: unsigned int checksum, stored_checksum;
466:
467: restart:
468:
469: /* Check if input size is less than minimum packet size. */
470: if (buffer_len(&input) < 4 + 8)
471: return SSH_MSG_NONE;
472: /* Get length of incoming packet. */
473: ucp = (unsigned char *) buffer_ptr(&input);
474: len = GET_32BIT(ucp);
475: if (len < 1 + 2 + 2 || len > 256 * 1024)
476: packet_disconnect("Bad packet length %d.", len);
477: padded_len = (len + 8) & ~7;
478:
479: /* Check if the packet has been entirely received. */
480: if (buffer_len(&input) < 4 + padded_len)
481: return SSH_MSG_NONE;
482:
483: /* The entire packet is in buffer. */
484:
485: /* Consume packet length. */
486: buffer_consume(&input, 4);
487:
488: /* Copy data to incoming_packet. */
489: buffer_clear(&incoming_packet);
490: buffer_append_space(&incoming_packet, &cp, padded_len);
491: packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
492: buffer_consume(&input, padded_len);
1.1 deraadt 493:
494: #ifdef PACKET_DEBUG
1.14 markus 495: fprintf(stderr, "read_poll plain: ");
496: buffer_dump(&incoming_packet);
1.1 deraadt 497: #endif
498:
1.14 markus 499: /* Compute packet checksum. */
500: checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet),
501: buffer_len(&incoming_packet) - 4);
502:
503: /* Skip padding. */
504: buffer_consume(&incoming_packet, 8 - len % 8);
505:
506: /* Test check bytes. */
507:
508: if (len != buffer_len(&incoming_packet))
509: packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
510: len, buffer_len(&incoming_packet));
511:
512: ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4;
513: stored_checksum = GET_32BIT(ucp);
514: if (checksum != stored_checksum)
515: packet_disconnect("Corrupted check bytes on input.");
516: buffer_consume_end(&incoming_packet, 4);
517:
518: /* If using packet compression, decompress the packet. */
519: if (packet_compression) {
520: buffer_clear(&compression_buffer);
521: buffer_uncompress(&incoming_packet, &compression_buffer);
522: buffer_clear(&incoming_packet);
523: buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
524: buffer_len(&compression_buffer));
525: }
526: /* Get packet type. */
527: buffer_get(&incoming_packet, &buf[0], 1);
528:
529: /* Return length of payload (without type field). */
530: *payload_len_ptr = buffer_len(&incoming_packet);
531:
532: /* Handle disconnect message. */
1.17 ! markus 533: if ((unsigned char) buf[0] == SSH_MSG_DISCONNECT) {
! 534: log("Received disconnect: %.900s", packet_get_string(NULL));
! 535: fatal_cleanup();
! 536: }
1.14 markus 537:
538: /* Ignore ignore messages. */
539: if ((unsigned char) buf[0] == SSH_MSG_IGNORE)
540: goto restart;
541:
542: /* Send debug messages as debugging output. */
543: if ((unsigned char) buf[0] == SSH_MSG_DEBUG) {
544: debug("Remote: %.900s", packet_get_string(NULL));
545: goto restart;
546: }
547: /* Return type. */
548: return (unsigned char) buf[0];
1.1 deraadt 549: }
1.14 markus 550:
1.16 markus 551: /*
552: * Buffers the given amount of input characters. This is intended to be used
553: * together with packet_read_poll.
554: */
1.1 deraadt 555:
1.2 provos 556: void
557: packet_process_incoming(const char *buf, unsigned int len)
1.1 deraadt 558: {
1.14 markus 559: buffer_append(&input, buf, len);
1.1 deraadt 560: }
561:
562: /* Returns a character from the packet. */
563:
1.2 provos 564: unsigned int
565: packet_get_char()
1.1 deraadt 566: {
1.14 markus 567: char ch;
568: buffer_get(&incoming_packet, &ch, 1);
569: return (unsigned char) ch;
1.1 deraadt 570: }
571:
572: /* Returns an integer from the packet data. */
573:
1.2 provos 574: unsigned int
575: packet_get_int()
1.1 deraadt 576: {
1.14 markus 577: return buffer_get_int(&incoming_packet);
1.1 deraadt 578: }
579:
1.16 markus 580: /*
581: * Returns an arbitrary precision integer from the packet data. The integer
582: * must have been initialized before this call.
583: */
1.1 deraadt 584:
1.2 provos 585: void
1.14 markus 586: packet_get_bignum(BIGNUM * value, int *length_ptr)
1.1 deraadt 587: {
1.14 markus 588: *length_ptr = buffer_get_bignum(&incoming_packet, value);
1.1 deraadt 589: }
590:
1.16 markus 591: /*
592: * Returns a string from the packet data. The string is allocated using
593: * xmalloc; it is the responsibility of the calling program to free it when
594: * no longer needed. The length_ptr argument may be NULL, or point to an
595: * integer into which the length of the string is stored.
596: */
1.1 deraadt 597:
1.16 markus 598: char *
1.14 markus 599: packet_get_string(unsigned int *length_ptr)
1.1 deraadt 600: {
1.14 markus 601: return buffer_get_string(&incoming_packet, length_ptr);
1.1 deraadt 602: }
603:
1.16 markus 604: /*
605: * Sends a diagnostic message from the server to the client. This message
606: * can be sent at any time (but not while constructing another message). The
607: * message is printed immediately, but only if the client is being executed
608: * in verbose mode. These messages are primarily intended to ease debugging
609: * authentication problems. The length of the formatted message must not
610: * exceed 1024 bytes. This will automatically call packet_write_wait.
611: */
1.1 deraadt 612:
1.2 provos 613: void
1.14 markus 614: packet_send_debug(const char *fmt,...)
1.1 deraadt 615: {
1.14 markus 616: char buf[1024];
617: va_list args;
618:
619: va_start(args, fmt);
620: vsnprintf(buf, sizeof(buf), fmt, args);
621: va_end(args);
622:
623: packet_start(SSH_MSG_DEBUG);
624: packet_put_string(buf, strlen(buf));
625: packet_send();
626: packet_write_wait();
1.1 deraadt 627: }
628:
1.16 markus 629: /*
630: * Logs the error plus constructs and sends a disconnect packet, closes the
631: * connection, and exits. This function never returns. The error message
632: * should not contain a newline. The length of the formatted message must
633: * not exceed 1024 bytes.
634: */
1.1 deraadt 635:
1.2 provos 636: void
1.14 markus 637: packet_disconnect(const char *fmt,...)
1.1 deraadt 638: {
1.14 markus 639: char buf[1024];
640: va_list args;
641: static int disconnecting = 0;
642: if (disconnecting) /* Guard against recursive invocations. */
643: fatal("packet_disconnect called recursively.");
644: disconnecting = 1;
645:
1.16 markus 646: /*
647: * Format the message. Note that the caller must make sure the
648: * message is of limited size.
649: */
1.14 markus 650: va_start(args, fmt);
651: vsnprintf(buf, sizeof(buf), fmt, args);
652: va_end(args);
653:
654: /* Send the disconnect message to the other side, and wait for it to get sent. */
655: packet_start(SSH_MSG_DISCONNECT);
656: packet_put_string(buf, strlen(buf));
657: packet_send();
658: packet_write_wait();
659:
660: /* Stop listening for connections. */
661: channel_stop_listening();
662:
663: /* Close the connection. */
664: packet_close();
1.1 deraadt 665:
1.14 markus 666: /* Display the error locally and exit. */
1.17 ! markus 667: log("Disconnecting: %.100s", buf);
! 668: fatal_cleanup();
1.1 deraadt 669: }
670:
1.16 markus 671: /* Checks if there is any buffered output, and tries to write some of the output. */
1.1 deraadt 672:
1.2 provos 673: void
674: packet_write_poll()
1.1 deraadt 675: {
1.14 markus 676: int len = buffer_len(&output);
677: if (len > 0) {
678: len = write(connection_out, buffer_ptr(&output), len);
679: if (len <= 0) {
680: if (errno == EAGAIN)
681: return;
682: else
683: fatal("Write failed: %.100s", strerror(errno));
684: }
685: buffer_consume(&output, len);
686: }
1.1 deraadt 687: }
688:
1.16 markus 689: /*
690: * Calls packet_write_poll repeatedly until all pending output data has been
691: * written.
692: */
1.1 deraadt 693:
1.2 provos 694: void
695: packet_write_wait()
1.1 deraadt 696: {
1.14 markus 697: packet_write_poll();
698: while (packet_have_data_to_write()) {
699: fd_set set;
700: FD_ZERO(&set);
701: FD_SET(connection_out, &set);
702: select(connection_out + 1, NULL, &set, NULL, NULL);
703: packet_write_poll();
704: }
1.1 deraadt 705: }
706:
707: /* Returns true if there is buffered data to write to the connection. */
708:
1.2 provos 709: int
710: packet_have_data_to_write()
1.1 deraadt 711: {
1.14 markus 712: return buffer_len(&output) != 0;
1.1 deraadt 713: }
714:
715: /* Returns true if there is not too much data to write to the connection. */
716:
1.2 provos 717: int
718: packet_not_very_much_data_to_write()
1.1 deraadt 719: {
1.14 markus 720: if (interactive_mode)
721: return buffer_len(&output) < 16384;
722: else
723: return buffer_len(&output) < 128 * 1024;
1.1 deraadt 724: }
725:
726: /* Informs that the current session is interactive. Sets IP flags for that. */
727:
1.2 provos 728: void
729: packet_set_interactive(int interactive, int keepalives)
1.1 deraadt 730: {
1.14 markus 731: int on = 1;
1.1 deraadt 732:
1.14 markus 733: /* Record that we are in interactive mode. */
734: interactive_mode = interactive;
1.1 deraadt 735:
1.16 markus 736: /*
737: * Only set socket options if using a socket (as indicated by the
738: * descriptors being the same).
739: */
1.14 markus 740: if (connection_in != connection_out)
741: return;
742:
743: if (keepalives) {
744: /* Set keepalives if requested. */
745: if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on,
746: sizeof(on)) < 0)
747: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
748: }
749: if (interactive) {
1.16 markus 750: /*
751: * Set IP options for an interactive connection. Use
752: * IPTOS_LOWDELAY and TCP_NODELAY.
753: */
1.14 markus 754: int lowdelay = IPTOS_LOWDELAY;
755: if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay,
756: sizeof(lowdelay)) < 0)
757: error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno));
758: if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on,
759: sizeof(on)) < 0)
760: error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
761: } else {
1.16 markus 762: /*
763: * Set IP options for a non-interactive connection. Use
764: * IPTOS_THROUGHPUT.
765: */
1.14 markus 766: int throughput = IPTOS_THROUGHPUT;
767: if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput,
768: sizeof(throughput)) < 0)
769: error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
770: }
1.1 deraadt 771: }
772:
773: /* Returns true if the current connection is interactive. */
774:
1.2 provos 775: int
776: packet_is_interactive()
1.1 deraadt 777: {
1.14 markus 778: return interactive_mode;
1.12 markus 779: }
780:
781: int
782: packet_set_maxsize(int s)
783: {
1.14 markus 784: static int called = 0;
785: if (called) {
786: log("packet_set_maxsize: called twice: old %d new %d", max_packet_size, s);
787: return -1;
788: }
789: if (s < 4 * 1024 || s > 1024 * 1024) {
790: log("packet_set_maxsize: bad size %d", s);
791: return -1;
792: }
793: log("packet_set_maxsize: setting to %d", s);
794: max_packet_size = s;
795: return s;
1.1 deraadt 796: }
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