JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1993, 1994, 1995, 1996, 1997 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that: (1) source code distributions |
| 7 | * retain the above copyright notice and this paragraph in its entirety, (2) |
| 8 | * distributions including binary code include the above copyright notice and |
| 9 | * this paragraph in its entirety in the documentation or other materials |
| 10 | * provided with the distribution, and (3) all advertising materials mentioning |
| 11 | * features or use of this software display the following acknowledgement: |
| 12 | * ``This product includes software developed by the University of California, |
| 13 | * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of |
| 14 | * the University nor the names of its contributors may be used to endorse |
| 15 | * or promote products derived from this software without specific prior |
| 16 | * written permission. |
| 17 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED |
| 18 | * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
| 19 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 20 | * |
| 21 | * sf-pcap-ng.c - pcap-ng-file-format-specific code from savefile.c |
| 22 | */ |
| 23 | |
| 24 | #ifndef lint |
| 25 | static const char rcsid[] _U_ = |
| 26 | "@(#) $Header$ (LBL)"; |
| 27 | #endif |
| 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | #include "config.h" |
| 31 | #endif |
| 32 | |
| 33 | #ifdef WIN32 |
| 34 | #include <pcap-stdinc.h> |
| 35 | #else /* WIN32 */ |
| 36 | #if HAVE_INTTYPES_H |
| 37 | #include <inttypes.h> |
| 38 | #elif HAVE_STDINT_H |
| 39 | #include <stdint.h> |
| 40 | #endif |
| 41 | #ifdef HAVE_SYS_BITYPES_H |
| 42 | #include <sys/bitypes.h> |
| 43 | #endif |
| 44 | #include <sys/types.h> |
| 45 | #endif /* WIN32 */ |
| 46 | |
| 47 | #include <errno.h> |
| 48 | #include <memory.h> |
| 49 | #include <stdio.h> |
| 50 | #include <stdlib.h> |
| 51 | #include <string.h> |
| 52 | |
| 53 | #include "pcap-int.h" |
| 54 | |
| 55 | #include "pcap-common.h" |
| 56 | |
| 57 | #ifdef HAVE_OS_PROTO_H |
| 58 | #include "os-proto.h" |
| 59 | #endif |
| 60 | |
| 61 | #include "sf-pcap-ng.h" |
| 62 | |
| 63 | /* |
| 64 | * Block types. |
| 65 | */ |
| 66 | |
| 67 | /* |
| 68 | * Common part at the beginning of all blocks. |
| 69 | */ |
| 70 | struct block_header { |
| 71 | bpf_u_int32 block_type; |
| 72 | bpf_u_int32 total_length; |
| 73 | }; |
| 74 | |
| 75 | /* |
| 76 | * Common trailer at the end of all blocks. |
| 77 | */ |
| 78 | struct block_trailer { |
| 79 | bpf_u_int32 total_length; |
| 80 | }; |
| 81 | |
| 82 | /* |
| 83 | * Common options. |
| 84 | */ |
| 85 | #define OPT_ENDOFOPT 0 /* end of options */ |
| 86 | #define OPT_COMMENT 1 /* comment string */ |
| 87 | |
| 88 | /* |
| 89 | * Option header. |
| 90 | */ |
| 91 | struct option_header { |
| 92 | u_short option_code; |
| 93 | u_short option_length; |
| 94 | }; |
| 95 | |
| 96 | /* |
| 97 | * Structures for the part of each block type following the common |
| 98 | * part. |
| 99 | */ |
| 100 | |
| 101 | /* |
| 102 | * Section Header Block. |
| 103 | */ |
| 104 | #define BT_SHB 0x0A0D0D0A |
| 105 | |
| 106 | struct section_header_block { |
| 107 | bpf_u_int32 byte_order_magic; |
| 108 | u_short major_version; |
| 109 | u_short minor_version; |
| 110 | u_int64_t section_length; |
| 111 | /* followed by options and trailer */ |
| 112 | }; |
| 113 | |
| 114 | /* |
| 115 | * Byte-order magic value. |
| 116 | */ |
| 117 | #define BYTE_ORDER_MAGIC 0x1A2B3C4D |
| 118 | |
| 119 | /* |
| 120 | * Current version number. If major_version isn't PCAP_NG_VERSION_MAJOR, |
| 121 | * that means that this code can't read the file. |
| 122 | */ |
| 123 | #define PCAP_NG_VERSION_MAJOR 1 |
| 124 | |
| 125 | /* |
| 126 | * Interface Description Block. |
| 127 | */ |
| 128 | #define BT_IDB 0x00000001 |
| 129 | |
| 130 | struct interface_description_block { |
| 131 | u_short linktype; |
| 132 | u_short reserved; |
| 133 | bpf_u_int32 snaplen; |
| 134 | /* followed by options and trailer */ |
| 135 | }; |
| 136 | |
| 137 | /* |
| 138 | * Options in the IDB. |
| 139 | */ |
| 140 | #define IF_NAME 2 /* interface name string */ |
| 141 | #define IF_DESCRIPTION 3 /* interface description string */ |
| 142 | #define IF_IPV4ADDR 4 /* interface's IPv4 address and netmask */ |
| 143 | #define IF_IPV6ADDR 5 /* interface's IPv6 address and prefix length */ |
| 144 | #define IF_MACADDR 6 /* interface's MAC address */ |
| 145 | #define IF_EUIADDR 7 /* interface's EUI address */ |
| 146 | #define IF_SPEED 8 /* interface's speed, in bits/s */ |
| 147 | #define IF_TSRESOL 9 /* interface's time stamp resolution */ |
| 148 | #define IF_TZONE 10 /* interface's time zone */ |
| 149 | #define IF_FILTER 11 /* filter used when capturing on interface */ |
| 150 | #define IF_OS 12 /* string OS on which capture on this interface was done */ |
| 151 | #define IF_FCSLEN 13 /* FCS length for this interface */ |
| 152 | #define IF_TSOFFSET 14 /* time stamp offset for this interface */ |
| 153 | |
| 154 | /* |
| 155 | * Enhanced Packet Block. |
| 156 | */ |
| 157 | #define BT_EPB 0x00000006 |
| 158 | |
| 159 | struct enhanced_packet_block { |
| 160 | bpf_u_int32 interface_id; |
| 161 | bpf_u_int32 timestamp_high; |
| 162 | bpf_u_int32 timestamp_low; |
| 163 | bpf_u_int32 caplen; |
| 164 | bpf_u_int32 len; |
| 165 | /* followed by packet data, options, and trailer */ |
| 166 | }; |
| 167 | |
| 168 | /* |
| 169 | * Simple Packet Block. |
| 170 | */ |
| 171 | #define BT_SPB 0x00000003 |
| 172 | |
| 173 | struct simple_packet_block { |
| 174 | bpf_u_int32 len; |
| 175 | /* followed by packet data and trailer */ |
| 176 | }; |
| 177 | |
| 178 | /* |
| 179 | * Packet Block. |
| 180 | */ |
| 181 | #define BT_PB 0x00000002 |
| 182 | |
| 183 | struct packet_block { |
| 184 | u_short interface_id; |
| 185 | u_short drops_count; |
| 186 | bpf_u_int32 timestamp_high; |
| 187 | bpf_u_int32 timestamp_low; |
| 188 | bpf_u_int32 caplen; |
| 189 | bpf_u_int32 len; |
| 190 | /* followed by packet data, options, and trailer */ |
| 191 | }; |
| 192 | |
| 193 | /* |
| 194 | * Block cursor - used when processing the contents of a block. |
| 195 | * Contains a pointer into the data being processed and a count |
| 196 | * of bytes remaining in the block. |
| 197 | */ |
| 198 | struct block_cursor { |
| 199 | u_char *data; |
| 200 | size_t data_remaining; |
| 201 | bpf_u_int32 block_type; |
| 202 | }; |
| 203 | |
| 204 | typedef enum { |
| 205 | PASS_THROUGH, |
| 206 | SCALE_UP, |
| 207 | SCALE_DOWN |
| 208 | } tstamp_scale_type_t; |
| 209 | |
| 210 | /* |
| 211 | * Per-interface information. |
| 212 | */ |
| 213 | struct pcap_ng_if { |
| 214 | u_int tsresol; /* time stamp resolution */ |
| 215 | u_int64_t tsoffset; /* time stamp offset */ |
| 216 | tstamp_scale_type_t scale_type; /* how to scale */ |
| 217 | }; |
| 218 | |
| 219 | struct pcap_ng_sf { |
| 220 | u_int user_tsresol; /* time stamp resolution requested by the user */ |
| 221 | bpf_u_int32 ifcount; /* number of interfaces seen in this capture */ |
| 222 | bpf_u_int32 ifaces_size; /* size of arrary below */ |
| 223 | struct pcap_ng_if *ifaces; /* array of interface information */ |
| 224 | }; |
| 225 | |
| 226 | static void pcap_ng_cleanup(pcap_t *p); |
| 227 | static int pcap_ng_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, |
| 228 | u_char **data); |
| 229 | |
| 230 | static int |
| 231 | read_bytes(FILE *fp, void *buf, size_t bytes_to_read, int fail_on_eof, |
| 232 | char *errbuf) |
| 233 | { |
| 234 | size_t amt_read; |
| 235 | |
| 236 | amt_read = fread(buf, 1, bytes_to_read, fp); |
| 237 | if (amt_read != bytes_to_read) { |
| 238 | if (ferror(fp)) { |
| 239 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 240 | "error reading dump file: %s", |
| 241 | pcap_strerror(errno)); |
| 242 | } else { |
| 243 | if (amt_read == 0 && !fail_on_eof) |
| 244 | return (0); /* EOF */ |
| 245 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 246 | "truncated dump file; tried to read %lu bytes, only got %lu", |
| 247 | (unsigned long)bytes_to_read, |
| 248 | (unsigned long)amt_read); |
| 249 | } |
| 250 | return (-1); |
| 251 | } |
| 252 | return (1); |
| 253 | } |
| 254 | |
| 255 | static int |
| 256 | read_block(FILE *fp, pcap_t *p, struct block_cursor *cursor, char *errbuf) |
| 257 | { |
| 258 | int status; |
| 259 | struct block_header bhdr; |
| 260 | |
| 261 | status = read_bytes(fp, &bhdr, sizeof(bhdr), 0, errbuf); |
| 262 | if (status <= 0) |
| 263 | return (status); /* error or EOF */ |
| 264 | |
| 265 | if (p->swapped) { |
| 266 | bhdr.block_type = SWAPLONG(bhdr.block_type); |
| 267 | bhdr.total_length = SWAPLONG(bhdr.total_length); |
| 268 | } |
| 269 | |
| 270 | /* |
| 271 | * Is this block "too big"? |
| 272 | * |
| 273 | * We choose 16MB as "too big", for now, so that we handle |
| 274 | * "reasonably" large buffers but don't chew up all the |
| 275 | * memory if we read a malformed file. |
| 276 | */ |
| 277 | if (bhdr.total_length > 16*1024*1024) { |
| 278 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 279 | "pcap-ng block size %u > maximum %u", |
| 280 | bhdr.total_length, 16*1024*1024); |
| 281 | return (-1); |
| 282 | } |
| 283 | |
| 284 | /* |
| 285 | * Is this block "too small" - i.e., is it shorter than a block |
| 286 | * header plus a block trailer? |
| 287 | */ |
| 288 | if (bhdr.total_length < sizeof(struct block_header) + |
| 289 | sizeof(struct block_trailer)) { |
| 290 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 291 | "block in pcap-ng dump file has a length of %u < %lu", |
| 292 | bhdr.total_length, |
| 293 | (unsigned long)(sizeof(struct block_header) + sizeof(struct block_trailer))); |
| 294 | return (-1); |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * Is the buffer big enough? |
| 299 | */ |
| 300 | if (p->bufsize < bhdr.total_length) { |
| 301 | /* |
| 302 | * No - make it big enough. |
| 303 | */ |
| 304 | p->buffer = realloc(p->buffer, bhdr.total_length); |
| 305 | if (p->buffer == NULL) { |
| 306 | snprintf(errbuf, PCAP_ERRBUF_SIZE, "out of memory"); |
| 307 | return (-1); |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Copy the stuff we've read to the buffer, and read the rest |
| 313 | * of the block. |
| 314 | */ |
| 315 | memcpy(p->buffer, &bhdr, sizeof(bhdr)); |
| 316 | if (read_bytes(fp, p->buffer + sizeof(bhdr), |
| 317 | bhdr.total_length - sizeof(bhdr), 1, errbuf) == -1) |
| 318 | return (-1); |
| 319 | |
| 320 | /* |
| 321 | * Initialize the cursor. |
| 322 | */ |
| 323 | cursor->data = p->buffer + sizeof(bhdr); |
| 324 | cursor->data_remaining = bhdr.total_length - sizeof(bhdr) - |
| 325 | sizeof(struct block_trailer); |
| 326 | cursor->block_type = bhdr.block_type; |
| 327 | return (1); |
| 328 | } |
| 329 | |
| 330 | static void * |
| 331 | get_from_block_data(struct block_cursor *cursor, size_t chunk_size, |
| 332 | char *errbuf) |
| 333 | { |
| 334 | void *data; |
| 335 | |
| 336 | /* |
| 337 | * Make sure we have the specified amount of data remaining in |
| 338 | * the block data. |
| 339 | */ |
| 340 | if (cursor->data_remaining < chunk_size) { |
| 341 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 342 | "block of type %u in pcap-ng dump file is too short", |
| 343 | cursor->block_type); |
| 344 | return (NULL); |
| 345 | } |
| 346 | |
| 347 | /* |
| 348 | * Return the current pointer, and skip past the chunk. |
| 349 | */ |
| 350 | data = cursor->data; |
| 351 | cursor->data += chunk_size; |
| 352 | cursor->data_remaining -= chunk_size; |
| 353 | return (data); |
| 354 | } |
| 355 | |
| 356 | static struct option_header * |
| 357 | get_opthdr_from_block_data(pcap_t *p, struct block_cursor *cursor, char *errbuf) |
| 358 | { |
| 359 | struct option_header *opthdr; |
| 360 | |
| 361 | opthdr = get_from_block_data(cursor, sizeof(*opthdr), errbuf); |
| 362 | if (opthdr == NULL) { |
| 363 | /* |
| 364 | * Option header is cut short. |
| 365 | */ |
| 366 | return (NULL); |
| 367 | } |
| 368 | |
| 369 | /* |
| 370 | * Byte-swap it if necessary. |
| 371 | */ |
| 372 | if (p->swapped) { |
| 373 | opthdr->option_code = SWAPSHORT(opthdr->option_code); |
| 374 | opthdr->option_length = SWAPSHORT(opthdr->option_length); |
| 375 | } |
| 376 | |
| 377 | return (opthdr); |
| 378 | } |
| 379 | |
| 380 | static void * |
| 381 | get_optvalue_from_block_data(struct block_cursor *cursor, |
| 382 | struct option_header *opthdr, char *errbuf) |
| 383 | { |
| 384 | size_t padded_option_len; |
| 385 | void *optvalue; |
| 386 | |
| 387 | /* Pad option length to 4-byte boundary */ |
| 388 | padded_option_len = opthdr->option_length; |
| 389 | padded_option_len = ((padded_option_len + 3)/4)*4; |
| 390 | |
| 391 | optvalue = get_from_block_data(cursor, padded_option_len, errbuf); |
| 392 | if (optvalue == NULL) { |
| 393 | /* |
| 394 | * Option value is cut short. |
| 395 | */ |
| 396 | return (NULL); |
| 397 | } |
| 398 | |
| 399 | return (optvalue); |
| 400 | } |
| 401 | |
| 402 | static int |
| 403 | process_idb_options(pcap_t *p, struct block_cursor *cursor, u_int *tsresol, |
| 404 | u_int64_t *tsoffset, char *errbuf) |
| 405 | { |
| 406 | struct option_header *opthdr; |
| 407 | void *optvalue; |
| 408 | int saw_tsresol, saw_tsoffset; |
| 409 | u_char tsresol_opt; |
| 410 | u_int i; |
| 411 | |
| 412 | saw_tsresol = 0; |
| 413 | saw_tsoffset = 0; |
| 414 | while (cursor->data_remaining != 0) { |
| 415 | /* |
| 416 | * Get the option header. |
| 417 | */ |
| 418 | opthdr = get_opthdr_from_block_data(p, cursor, errbuf); |
| 419 | if (opthdr == NULL) { |
| 420 | /* |
| 421 | * Option header is cut short. |
| 422 | */ |
| 423 | return (-1); |
| 424 | } |
| 425 | |
| 426 | /* |
| 427 | * Get option value. |
| 428 | */ |
| 429 | optvalue = get_optvalue_from_block_data(cursor, opthdr, |
| 430 | errbuf); |
| 431 | if (optvalue == NULL) { |
| 432 | /* |
| 433 | * Option value is cut short. |
| 434 | */ |
| 435 | return (-1); |
| 436 | } |
| 437 | |
| 438 | switch (opthdr->option_code) { |
| 439 | |
| 440 | case OPT_ENDOFOPT: |
| 441 | if (opthdr->option_length != 0) { |
| 442 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 443 | "Interface Description Block has opt_endofopt option with length %u != 0", |
| 444 | opthdr->option_length); |
| 445 | return (-1); |
| 446 | } |
| 447 | goto done; |
| 448 | |
| 449 | case IF_TSRESOL: |
| 450 | if (opthdr->option_length != 1) { |
| 451 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 452 | "Interface Description Block has if_tsresol option with length %u != 1", |
| 453 | opthdr->option_length); |
| 454 | return (-1); |
| 455 | } |
| 456 | if (saw_tsresol) { |
| 457 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 458 | "Interface Description Block has more than one if_tsresol option"); |
| 459 | return (-1); |
| 460 | } |
| 461 | saw_tsresol = 1; |
| 462 | tsresol_opt = *(u_int *)optvalue; |
| 463 | if (tsresol_opt & 0x80) { |
| 464 | /* |
| 465 | * Resolution is negative power of 2. |
| 466 | */ |
| 467 | *tsresol = 1 << (tsresol_opt & 0x7F); |
| 468 | } else { |
| 469 | /* |
| 470 | * Resolution is negative power of 10. |
| 471 | */ |
| 472 | *tsresol = 1; |
| 473 | for (i = 0; i < tsresol_opt; i++) |
| 474 | *tsresol *= 10; |
| 475 | } |
| 476 | if (*tsresol == 0) { |
| 477 | /* |
| 478 | * Resolution is too high. |
| 479 | */ |
| 480 | if (tsresol_opt & 0x80) { |
| 481 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 482 | "Interface Description Block if_tsresol option resolution 2^-%u is too high", |
| 483 | tsresol_opt & 0x7F); |
| 484 | } else { |
| 485 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 486 | "Interface Description Block if_tsresol option resolution 10^-%u is too high", |
| 487 | tsresol_opt); |
| 488 | } |
| 489 | return (-1); |
| 490 | } |
| 491 | break; |
| 492 | |
| 493 | case IF_TSOFFSET: |
| 494 | if (opthdr->option_length != 8) { |
| 495 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 496 | "Interface Description Block has if_tsoffset option with length %u != 8", |
| 497 | opthdr->option_length); |
| 498 | return (-1); |
| 499 | } |
| 500 | if (saw_tsoffset) { |
| 501 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 502 | "Interface Description Block has more than one if_tsoffset option"); |
| 503 | return (-1); |
| 504 | } |
| 505 | saw_tsoffset = 1; |
| 506 | memcpy(tsoffset, optvalue, sizeof(*tsoffset)); |
| 507 | if (p->swapped) |
| 508 | *tsoffset = SWAPLL(*tsoffset); |
| 509 | break; |
| 510 | |
| 511 | default: |
| 512 | break; |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | done: |
| 517 | return (0); |
| 518 | } |
| 519 | |
| 520 | static int |
| 521 | add_interface(pcap_t *p, struct block_cursor *cursor, char *errbuf) |
| 522 | { |
| 523 | struct pcap_ng_sf *ps; |
| 524 | u_int tsresol; |
| 525 | u_int64_t tsoffset; |
| 526 | |
| 527 | ps = p->priv; |
| 528 | |
| 529 | /* |
| 530 | * Count this interface. |
| 531 | */ |
| 532 | ps->ifcount++; |
| 533 | |
| 534 | /* |
| 535 | * Grow the array of per-interface information as necessary. |
| 536 | */ |
| 537 | if (ps->ifcount > ps->ifaces_size) { |
| 538 | /* |
| 539 | * We need to grow the array. |
| 540 | */ |
| 541 | if (ps->ifaces == NULL) { |
| 542 | /* |
| 543 | * It's currently empty. |
| 544 | */ |
| 545 | ps->ifaces_size = 1; |
| 546 | ps->ifaces = malloc(sizeof (struct pcap_ng_if)); |
| 547 | } else { |
| 548 | /* |
| 549 | * It's not currently empty; double its size. |
| 550 | * (Perhaps overkill once we have a lot of interfaces.) |
| 551 | */ |
| 552 | ps->ifaces_size *= 2; |
| 553 | ps->ifaces = realloc(ps->ifaces, ps->ifaces_size * sizeof (struct pcap_ng_if)); |
| 554 | } |
| 555 | if (ps->ifaces == NULL) { |
| 556 | /* |
| 557 | * We ran out of memory. |
| 558 | * Give up. |
| 559 | */ |
| 560 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 561 | "out of memory for per-interface information (%u interfaces)", |
| 562 | ps->ifcount); |
| 563 | return (0); |
| 564 | } |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * Set the default time stamp resolution and offset. |
| 569 | */ |
| 570 | tsresol = 1000000; /* microsecond resolution */ |
| 571 | tsoffset = 0; /* absolute timestamps */ |
| 572 | |
| 573 | /* |
| 574 | * Now look for various time stamp options, so we know |
| 575 | * how to interpret the time stamps for this interface. |
| 576 | */ |
| 577 | if (process_idb_options(p, cursor, &tsresol, &tsoffset, errbuf) == -1) |
| 578 | return (0); |
| 579 | |
| 580 | ps->ifaces[ps->ifcount - 1].tsresol = tsresol; |
| 581 | ps->ifaces[ps->ifcount - 1].tsoffset = tsoffset; |
| 582 | |
| 583 | /* |
| 584 | * Determine whether we're scaling up or down or not |
| 585 | * at all for this interface. |
| 586 | */ |
| 587 | switch (p->opt.tstamp_precision) { |
| 588 | |
| 589 | case PCAP_TSTAMP_PRECISION_MICRO: |
| 590 | if (tsresol == 1000000) { |
| 591 | /* |
| 592 | * The resolution is 1 microsecond, |
| 593 | * so we don't have to do scaling. |
| 594 | */ |
| 595 | ps->ifaces[ps->ifcount - 1].scale_type = PASS_THROUGH; |
| 596 | } else if (tsresol > 1000000) { |
| 597 | /* |
| 598 | * The resolution is greater than |
| 599 | * 1 microsecond, so we have to |
| 600 | * scale the timestamps down. |
| 601 | */ |
| 602 | ps->ifaces[ps->ifcount - 1].scale_type = SCALE_DOWN; |
| 603 | } else { |
| 604 | /* |
| 605 | * The resolution is less than 1 |
| 606 | * microsecond, so we have to scale |
| 607 | * the timestamps up. |
| 608 | */ |
| 609 | ps->ifaces[ps->ifcount - 1].scale_type = SCALE_UP; |
| 610 | } |
| 611 | break; |
| 612 | |
| 613 | case PCAP_TSTAMP_PRECISION_NANO: |
| 614 | if (tsresol == 1000000000) { |
| 615 | /* |
| 616 | * The resolution is 1 nanosecond, |
| 617 | * so we don't have to do scaling. |
| 618 | */ |
| 619 | ps->ifaces[ps->ifcount - 1].scale_type = PASS_THROUGH; |
| 620 | } else if (tsresol > 1000000000) { |
| 621 | /* |
| 622 | * The resolution is greater than |
| 623 | * 1 nanosecond, so we have to |
| 624 | * scale the timestamps down. |
| 625 | */ |
| 626 | ps->ifaces[ps->ifcount - 1].scale_type = SCALE_DOWN; |
| 627 | } else { |
| 628 | /* |
| 629 | * The resolution is less than 1 |
| 630 | * nanosecond, so we have to scale |
| 631 | * the timestamps up. |
| 632 | */ |
| 633 | ps->ifaces[ps->ifcount - 1].scale_type = SCALE_UP; |
| 634 | } |
| 635 | break; |
| 636 | } |
| 637 | return (1); |
| 638 | } |
| 639 | |
| 640 | /* |
| 641 | * Check whether this is a pcap-ng savefile and, if it is, extract the |
| 642 | * relevant information from the header. |
| 643 | */ |
| 644 | pcap_t * |
| 645 | pcap_ng_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf, |
| 646 | int *err) |
| 647 | { |
| 648 | size_t amt_read; |
| 649 | bpf_u_int32 total_length; |
| 650 | bpf_u_int32 byte_order_magic; |
| 651 | struct block_header *bhdrp; |
| 652 | struct section_header_block *shbp; |
| 653 | pcap_t *p; |
| 654 | int swapped = 0; |
| 655 | struct pcap_ng_sf *ps; |
| 656 | int status; |
| 657 | struct block_cursor cursor; |
| 658 | struct interface_description_block *idbp; |
| 659 | |
| 660 | /* |
| 661 | * Assume no read errors. |
| 662 | */ |
| 663 | *err = 0; |
| 664 | |
| 665 | /* |
| 666 | * Check whether the first 4 bytes of the file are the block |
| 667 | * type for a pcap-ng savefile. |
| 668 | */ |
| 669 | if (magic != BT_SHB) { |
| 670 | /* |
| 671 | * XXX - check whether this looks like what the block |
| 672 | * type would be after being munged by mapping between |
| 673 | * UN*X and DOS/Windows text file format and, if it |
| 674 | * does, look for the byte-order magic number in |
| 675 | * the appropriate place and, if we find it, report |
| 676 | * this as possibly being a pcap-ng file transferred |
| 677 | * between UN*X and Windows in text file format? |
| 678 | */ |
| 679 | return (NULL); /* nope */ |
| 680 | } |
| 681 | |
| 682 | /* |
| 683 | * OK, they are. However, that's just \n\r\r\n, so it could, |
| 684 | * conceivably, be an ordinary text file. |
| 685 | * |
| 686 | * It could not, however, conceivably be any other type of |
| 687 | * capture file, so we can read the rest of the putative |
| 688 | * Section Header Block; put the block type in the common |
| 689 | * header, read the rest of the common header and the |
| 690 | * fixed-length portion of the SHB, and look for the byte-order |
| 691 | * magic value. |
| 692 | */ |
| 693 | amt_read = fread(&total_length, 1, sizeof(total_length), fp); |
| 694 | if (amt_read < sizeof(total_length)) { |
| 695 | if (ferror(fp)) { |
| 696 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 697 | "error reading dump file: %s", |
| 698 | pcap_strerror(errno)); |
| 699 | *err = 1; |
| 700 | return (NULL); /* fail */ |
| 701 | } |
| 702 | |
| 703 | /* |
| 704 | * Possibly a weird short text file, so just say |
| 705 | * "not pcap-ng". |
| 706 | */ |
| 707 | return (NULL); |
| 708 | } |
| 709 | amt_read = fread(&byte_order_magic, 1, sizeof(byte_order_magic), fp); |
| 710 | if (amt_read < sizeof(byte_order_magic)) { |
| 711 | if (ferror(fp)) { |
| 712 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 713 | "error reading dump file: %s", |
| 714 | pcap_strerror(errno)); |
| 715 | *err = 1; |
| 716 | return (NULL); /* fail */ |
| 717 | } |
| 718 | |
| 719 | /* |
| 720 | * Possibly a weird short text file, so just say |
| 721 | * "not pcap-ng". |
| 722 | */ |
| 723 | return (NULL); |
| 724 | } |
| 725 | if (byte_order_magic != BYTE_ORDER_MAGIC) { |
| 726 | byte_order_magic = SWAPLONG(byte_order_magic); |
| 727 | if (byte_order_magic != BYTE_ORDER_MAGIC) { |
| 728 | /* |
| 729 | * Not a pcap-ng file. |
| 730 | */ |
| 731 | return (NULL); |
| 732 | } |
| 733 | swapped = 1; |
| 734 | total_length = SWAPLONG(total_length); |
| 735 | } |
| 736 | |
| 737 | /* |
| 738 | * Check the sanity of the total length. |
| 739 | */ |
| 740 | if (total_length < sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer)) { |
| 741 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 742 | "Section Header Block in pcap-ng dump file has a length of %u < %lu", |
| 743 | total_length, |
| 744 | (unsigned long)(sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer))); |
| 745 | *err = 1; |
| 746 | return (NULL); |
| 747 | } |
| 748 | |
| 749 | /* |
| 750 | * OK, this is a good pcap-ng file. |
| 751 | * Allocate a pcap_t for it. |
| 752 | */ |
| 753 | p = pcap_open_offline_common(errbuf, sizeof (struct pcap_ng_sf)); |
| 754 | if (p == NULL) { |
| 755 | /* Allocation failed. */ |
| 756 | *err = 1; |
| 757 | return (NULL); |
| 758 | } |
| 759 | p->swapped = swapped; |
| 760 | ps = p->priv; |
| 761 | |
| 762 | /* |
| 763 | * What precision does the user want? |
| 764 | */ |
| 765 | switch (precision) { |
| 766 | |
| 767 | case PCAP_TSTAMP_PRECISION_MICRO: |
| 768 | ps->user_tsresol = 1000000; |
| 769 | break; |
| 770 | |
| 771 | case PCAP_TSTAMP_PRECISION_NANO: |
| 772 | ps->user_tsresol = 1000000000; |
| 773 | break; |
| 774 | |
| 775 | default: |
| 776 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 777 | "unknown time stamp resolution %u", precision); |
| 778 | free(p); |
| 779 | *err = 1; |
| 780 | return (NULL); |
| 781 | } |
| 782 | |
| 783 | p->opt.tstamp_precision = precision; |
| 784 | |
| 785 | /* |
| 786 | * Allocate a buffer into which to read blocks. We default to |
| 787 | * the maximum of: |
| 788 | * |
| 789 | * the total length of the SHB for which we read the header; |
| 790 | * |
| 791 | * 2K, which should be more than large enough for an Enhanced |
| 792 | * Packet Block containing a full-size Ethernet frame, and |
| 793 | * leaving room for some options. |
| 794 | * |
| 795 | * If we find a bigger block, we reallocate the buffer. |
| 796 | */ |
| 797 | p->bufsize = 2048; |
| 798 | if (p->bufsize < total_length) |
| 799 | p->bufsize = total_length; |
| 800 | p->buffer = malloc(p->bufsize); |
| 801 | if (p->buffer == NULL) { |
| 802 | snprintf(errbuf, PCAP_ERRBUF_SIZE, "out of memory"); |
| 803 | free(p); |
| 804 | *err = 1; |
| 805 | return (NULL); |
| 806 | } |
| 807 | |
| 808 | /* |
| 809 | * Copy the stuff we've read to the buffer, and read the rest |
| 810 | * of the SHB. |
| 811 | */ |
| 812 | bhdrp = (struct block_header *)p->buffer; |
| 813 | shbp = (struct section_header_block *)(p->buffer + sizeof(struct block_header)); |
| 814 | bhdrp->block_type = magic; |
| 815 | bhdrp->total_length = total_length; |
| 816 | shbp->byte_order_magic = byte_order_magic; |
| 817 | if (read_bytes(fp, |
| 818 | p->buffer + (sizeof(magic) + sizeof(total_length) + sizeof(byte_order_magic)), |
| 819 | total_length - (sizeof(magic) + sizeof(total_length) + sizeof(byte_order_magic)), |
| 820 | 1, errbuf) == -1) |
| 821 | goto fail; |
| 822 | |
| 823 | if (p->swapped) { |
| 824 | /* |
| 825 | * Byte-swap the fields we've read. |
| 826 | */ |
| 827 | shbp->major_version = SWAPSHORT(shbp->major_version); |
| 828 | shbp->minor_version = SWAPSHORT(shbp->minor_version); |
| 829 | |
| 830 | /* |
| 831 | * XXX - we don't care about the section length. |
| 832 | */ |
| 833 | } |
| 834 | if (shbp->major_version != PCAP_NG_VERSION_MAJOR) { |
| 835 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 836 | "unknown pcap-ng savefile major version number %u", |
| 837 | shbp->major_version); |
| 838 | goto fail; |
| 839 | } |
| 840 | p->version_major = shbp->major_version; |
| 841 | p->version_minor = shbp->minor_version; |
| 842 | |
| 843 | /* |
| 844 | * Save the time stamp resolution the user requested. |
| 845 | */ |
| 846 | p->opt.tstamp_precision = precision; |
| 847 | |
| 848 | /* |
| 849 | * Now start looking for an Interface Description Block. |
| 850 | */ |
| 851 | for (;;) { |
| 852 | /* |
| 853 | * Read the next block. |
| 854 | */ |
| 855 | status = read_block(fp, p, &cursor, errbuf); |
| 856 | if (status == 0) { |
| 857 | /* EOF - no IDB in this file */ |
| 858 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 859 | "the capture file has no Interface Description Blocks"); |
| 860 | goto fail; |
| 861 | } |
| 862 | if (status == -1) |
| 863 | goto fail; /* error */ |
| 864 | switch (cursor.block_type) { |
| 865 | |
| 866 | case BT_IDB: |
| 867 | /* |
| 868 | * Get a pointer to the fixed-length portion of the |
| 869 | * IDB. |
| 870 | */ |
| 871 | idbp = get_from_block_data(&cursor, sizeof(*idbp), |
| 872 | errbuf); |
| 873 | if (idbp == NULL) |
| 874 | goto fail; /* error */ |
| 875 | |
| 876 | /* |
| 877 | * Byte-swap it if necessary. |
| 878 | */ |
| 879 | if (p->swapped) { |
| 880 | idbp->linktype = SWAPSHORT(idbp->linktype); |
| 881 | idbp->snaplen = SWAPLONG(idbp->snaplen); |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Try to add this interface. |
| 886 | */ |
| 887 | if (!add_interface(p, &cursor, errbuf)) |
| 888 | goto fail; |
| 889 | goto done; |
| 890 | |
| 891 | case BT_EPB: |
| 892 | case BT_SPB: |
| 893 | case BT_PB: |
| 894 | /* |
| 895 | * Saw a packet before we saw any IDBs. That's |
| 896 | * not valid, as we don't know what link-layer |
| 897 | * encapsulation the packet has. |
| 898 | */ |
| 899 | snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 900 | "the capture file has a packet block before any Interface Description Blocks"); |
| 901 | goto fail; |
| 902 | |
| 903 | default: |
| 904 | /* |
| 905 | * Just ignore it. |
| 906 | */ |
| 907 | break; |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | done: |
| 912 | p->tzoff = 0; /* XXX - not used in pcap */ |
| 913 | p->snapshot = idbp->snaplen; |
| 914 | p->linktype = linktype_to_dlt(idbp->linktype); |
| 915 | p->linktype_ext = 0; |
| 916 | |
| 917 | p->next_packet_op = pcap_ng_next_packet; |
| 918 | p->cleanup_op = pcap_ng_cleanup; |
| 919 | |
| 920 | return (p); |
| 921 | |
| 922 | fail: |
| 923 | free(ps->ifaces); |
| 924 | free(p->buffer); |
| 925 | free(p); |
| 926 | *err = 1; |
| 927 | return (NULL); |
| 928 | } |
| 929 | |
| 930 | static void |
| 931 | pcap_ng_cleanup(pcap_t *p) |
| 932 | { |
| 933 | struct pcap_ng_sf *ps = p->priv; |
| 934 | |
| 935 | free(ps->ifaces); |
| 936 | sf_cleanup(p); |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * Read and return the next packet from the savefile. Return the header |
| 941 | * in hdr and a pointer to the contents in data. Return 0 on success, 1 |
| 942 | * if there were no more packets, and -1 on an error. |
| 943 | */ |
| 944 | static int |
| 945 | pcap_ng_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data) |
| 946 | { |
| 947 | struct pcap_ng_sf *ps = p->priv; |
| 948 | struct block_cursor cursor; |
| 949 | int status; |
| 950 | struct enhanced_packet_block *epbp; |
| 951 | struct simple_packet_block *spbp; |
| 952 | struct packet_block *pbp; |
| 953 | bpf_u_int32 interface_id = 0xFFFFFFFF; |
| 954 | struct interface_description_block *idbp; |
| 955 | struct section_header_block *shbp; |
| 956 | FILE *fp = p->rfile; |
| 957 | u_int64_t t, sec, frac; |
| 958 | |
| 959 | /* |
| 960 | * Look for an Enhanced Packet Block, a Simple Packet Block, |
| 961 | * or a Packet Block. |
| 962 | */ |
| 963 | for (;;) { |
| 964 | /* |
| 965 | * Read the block type and length; those are common |
| 966 | * to all blocks. |
| 967 | */ |
| 968 | status = read_block(fp, p, &cursor, p->errbuf); |
| 969 | if (status == 0) |
| 970 | return (1); /* EOF */ |
| 971 | if (status == -1) |
| 972 | return (-1); /* error */ |
| 973 | switch (cursor.block_type) { |
| 974 | |
| 975 | case BT_EPB: |
| 976 | /* |
| 977 | * Get a pointer to the fixed-length portion of the |
| 978 | * EPB. |
| 979 | */ |
| 980 | epbp = get_from_block_data(&cursor, sizeof(*epbp), |
| 981 | p->errbuf); |
| 982 | if (epbp == NULL) |
| 983 | return (-1); /* error */ |
| 984 | |
| 985 | /* |
| 986 | * Byte-swap it if necessary. |
| 987 | */ |
| 988 | if (p->swapped) { |
| 989 | /* these were written in opposite byte order */ |
| 990 | interface_id = SWAPLONG(epbp->interface_id); |
| 991 | hdr->caplen = SWAPLONG(epbp->caplen); |
| 992 | hdr->len = SWAPLONG(epbp->len); |
| 993 | t = ((u_int64_t)SWAPLONG(epbp->timestamp_high)) << 32 | |
| 994 | SWAPLONG(epbp->timestamp_low); |
| 995 | } else { |
| 996 | interface_id = epbp->interface_id; |
| 997 | hdr->caplen = epbp->caplen; |
| 998 | hdr->len = epbp->len; |
| 999 | t = ((u_int64_t)epbp->timestamp_high) << 32 | |
| 1000 | epbp->timestamp_low; |
| 1001 | } |
| 1002 | goto found; |
| 1003 | |
| 1004 | case BT_SPB: |
| 1005 | /* |
| 1006 | * Get a pointer to the fixed-length portion of the |
| 1007 | * SPB. |
| 1008 | */ |
| 1009 | spbp = get_from_block_data(&cursor, sizeof(*spbp), |
| 1010 | p->errbuf); |
| 1011 | if (spbp == NULL) |
| 1012 | return (-1); /* error */ |
| 1013 | |
| 1014 | /* |
| 1015 | * SPB packets are assumed to have arrived on |
| 1016 | * the first interface. |
| 1017 | */ |
| 1018 | interface_id = 0; |
| 1019 | |
| 1020 | /* |
| 1021 | * Byte-swap it if necessary. |
| 1022 | */ |
| 1023 | if (p->swapped) { |
| 1024 | /* these were written in opposite byte order */ |
| 1025 | hdr->len = SWAPLONG(spbp->len); |
| 1026 | } else |
| 1027 | hdr->len = spbp->len; |
| 1028 | |
| 1029 | /* |
| 1030 | * The SPB doesn't give the captured length; |
| 1031 | * it's the minimum of the snapshot length |
| 1032 | * and the packet length. |
| 1033 | */ |
| 1034 | hdr->caplen = hdr->len; |
| 1035 | if (hdr->caplen > p->snapshot) |
| 1036 | hdr->caplen = p->snapshot; |
| 1037 | t = 0; /* no time stamps */ |
| 1038 | goto found; |
| 1039 | |
| 1040 | case BT_PB: |
| 1041 | /* |
| 1042 | * Get a pointer to the fixed-length portion of the |
| 1043 | * PB. |
| 1044 | */ |
| 1045 | pbp = get_from_block_data(&cursor, sizeof(*pbp), |
| 1046 | p->errbuf); |
| 1047 | if (pbp == NULL) |
| 1048 | return (-1); /* error */ |
| 1049 | |
| 1050 | /* |
| 1051 | * Byte-swap it if necessary. |
| 1052 | */ |
| 1053 | if (p->swapped) { |
| 1054 | /* these were written in opposite byte order */ |
| 1055 | interface_id = SWAPSHORT(pbp->interface_id); |
| 1056 | hdr->caplen = SWAPLONG(pbp->caplen); |
| 1057 | hdr->len = SWAPLONG(pbp->len); |
| 1058 | t = ((u_int64_t)SWAPLONG(pbp->timestamp_high)) << 32 | |
| 1059 | SWAPLONG(pbp->timestamp_low); |
| 1060 | } else { |
| 1061 | interface_id = pbp->interface_id; |
| 1062 | hdr->caplen = pbp->caplen; |
| 1063 | hdr->len = pbp->len; |
| 1064 | t = ((u_int64_t)pbp->timestamp_high) << 32 | |
| 1065 | pbp->timestamp_low; |
| 1066 | } |
| 1067 | goto found; |
| 1068 | |
| 1069 | case BT_IDB: |
| 1070 | /* |
| 1071 | * Interface Description Block. Get a pointer |
| 1072 | * to its fixed-length portion. |
| 1073 | */ |
| 1074 | idbp = get_from_block_data(&cursor, sizeof(*idbp), |
| 1075 | p->errbuf); |
| 1076 | if (idbp == NULL) |
| 1077 | return (-1); /* error */ |
| 1078 | |
| 1079 | /* |
| 1080 | * Byte-swap it if necessary. |
| 1081 | */ |
| 1082 | if (p->swapped) { |
| 1083 | idbp->linktype = SWAPSHORT(idbp->linktype); |
| 1084 | idbp->snaplen = SWAPLONG(idbp->snaplen); |
| 1085 | } |
| 1086 | |
| 1087 | /* |
| 1088 | * If the link-layer type or snapshot length |
| 1089 | * differ from the ones for the first IDB we |
| 1090 | * saw, quit. |
| 1091 | * |
| 1092 | * XXX - just discard packets from those |
| 1093 | * interfaces? |
| 1094 | */ |
| 1095 | if (p->linktype != idbp->linktype) { |
| 1096 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1097 | "an interface has a type %u different from the type of the first interface", |
| 1098 | idbp->linktype); |
| 1099 | return (-1); |
| 1100 | } |
| 1101 | if (p->snapshot != idbp->snaplen) { |
| 1102 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1103 | "an interface has a snapshot length %u different from the type of the first interface", |
| 1104 | idbp->snaplen); |
| 1105 | return (-1); |
| 1106 | } |
| 1107 | |
| 1108 | /* |
| 1109 | * Try to add this interface. |
| 1110 | */ |
| 1111 | if (!add_interface(p, &cursor, p->errbuf)) |
| 1112 | return (-1); |
| 1113 | break; |
| 1114 | |
| 1115 | case BT_SHB: |
| 1116 | /* |
| 1117 | * Section Header Block. Get a pointer |
| 1118 | * to its fixed-length portion. |
| 1119 | */ |
| 1120 | shbp = get_from_block_data(&cursor, sizeof(*shbp), |
| 1121 | p->errbuf); |
| 1122 | if (shbp == NULL) |
| 1123 | return (-1); /* error */ |
| 1124 | |
| 1125 | /* |
| 1126 | * Assume the byte order of this section is |
| 1127 | * the same as that of the previous section. |
| 1128 | * We'll check for that later. |
| 1129 | */ |
| 1130 | if (p->swapped) { |
| 1131 | shbp->byte_order_magic = |
| 1132 | SWAPLONG(shbp->byte_order_magic); |
| 1133 | shbp->major_version = |
| 1134 | SWAPSHORT(shbp->major_version); |
| 1135 | } |
| 1136 | |
| 1137 | /* |
| 1138 | * Make sure the byte order doesn't change; |
| 1139 | * pcap_is_swapped() shouldn't change its |
| 1140 | * return value in the middle of reading a capture. |
| 1141 | */ |
| 1142 | switch (shbp->byte_order_magic) { |
| 1143 | |
| 1144 | case BYTE_ORDER_MAGIC: |
| 1145 | /* |
| 1146 | * OK. |
| 1147 | */ |
| 1148 | break; |
| 1149 | |
| 1150 | case SWAPLONG(BYTE_ORDER_MAGIC): |
| 1151 | /* |
| 1152 | * Byte order changes. |
| 1153 | */ |
| 1154 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1155 | "the file has sections with different byte orders"); |
| 1156 | return (-1); |
| 1157 | |
| 1158 | default: |
| 1159 | /* |
| 1160 | * Not a valid SHB. |
| 1161 | */ |
| 1162 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1163 | "the file has a section with a bad byte order magic field"); |
| 1164 | return (-1); |
| 1165 | } |
| 1166 | |
| 1167 | /* |
| 1168 | * Make sure the major version is the version |
| 1169 | * we handle. |
| 1170 | */ |
| 1171 | if (shbp->major_version != PCAP_NG_VERSION_MAJOR) { |
| 1172 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1173 | "unknown pcap-ng savefile major version number %u", |
| 1174 | shbp->major_version); |
| 1175 | return (-1); |
| 1176 | } |
| 1177 | |
| 1178 | /* |
| 1179 | * Reset the interface count; this section should |
| 1180 | * have its own set of IDBs. If any of them |
| 1181 | * don't have the same interface type, snapshot |
| 1182 | * length, or resolution as the first interface |
| 1183 | * we saw, we'll fail. (And if we don't see |
| 1184 | * any IDBs, we'll fail when we see a packet |
| 1185 | * block.) |
| 1186 | */ |
| 1187 | ps->ifcount = 0; |
| 1188 | break; |
| 1189 | |
| 1190 | default: |
| 1191 | /* |
| 1192 | * Not a packet block, IDB, or SHB; ignore it. |
| 1193 | */ |
| 1194 | break; |
| 1195 | } |
| 1196 | } |
| 1197 | |
| 1198 | found: |
| 1199 | /* |
| 1200 | * Is the interface ID an interface we know? |
| 1201 | */ |
| 1202 | if (interface_id >= ps->ifcount) { |
| 1203 | /* |
| 1204 | * Yes. Fail. |
| 1205 | */ |
| 1206 | snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1207 | "a packet arrived on interface %u, but there's no Interface Description Block for that interface", |
| 1208 | interface_id); |
| 1209 | return (-1); |
| 1210 | } |
| 1211 | |
| 1212 | /* |
| 1213 | * Convert the time stamp to a struct timeval. |
| 1214 | */ |
| 1215 | sec = t / ps->ifaces[interface_id].tsresol + ps->ifaces[interface_id].tsoffset; |
| 1216 | frac = t % ps->ifaces[interface_id].tsresol; |
| 1217 | switch (ps->ifaces[interface_id].scale_type) { |
| 1218 | |
| 1219 | case PASS_THROUGH: |
| 1220 | /* |
| 1221 | * The interface resolution is what the user wants, |
| 1222 | * so we're done. |
| 1223 | */ |
| 1224 | break; |
| 1225 | |
| 1226 | case SCALE_UP: |
| 1227 | /* |
| 1228 | * The interface resolution is less than what the user |
| 1229 | * wants; scale up to that resolution. |
| 1230 | * |
| 1231 | * XXX - if ps->ifaces[interface_id].tsresol is a power |
| 1232 | * of 10, we could just multiply by the quotient of |
| 1233 | * ps->ifaces[interface_id].tsresol and ps->user_tsresol, |
| 1234 | * as we know that's an integer. That runs less risk of |
| 1235 | * overflow. |
| 1236 | * |
| 1237 | * Is there something clever we could do if |
| 1238 | * ps->ifaces[interface_id].tsresol is a power of 2? |
| 1239 | */ |
| 1240 | frac *= ps->ifaces[interface_id].tsresol; |
| 1241 | frac /= ps->user_tsresol; |
| 1242 | break; |
| 1243 | |
| 1244 | case SCALE_DOWN: |
| 1245 | /* |
| 1246 | * The interface resolution is greater than what the user |
| 1247 | * wants; scale down to that resolution. |
| 1248 | * |
| 1249 | * XXX - if ps->ifaces[interface_id].tsresol is a power |
| 1250 | * of 10, we could just divide by the quotient of |
| 1251 | * ps->user_tsresol and ps->ifaces[interface_id].tsresol, |
| 1252 | * as we know that's an integer. That runs less risk of |
| 1253 | * overflow. |
| 1254 | * |
| 1255 | * Is there something clever we could do if |
| 1256 | * ps->ifaces[interface_id].tsresol is a power of 2? |
| 1257 | */ |
| 1258 | frac *= ps->user_tsresol; |
| 1259 | frac /= ps->ifaces[interface_id].tsresol; |
| 1260 | break; |
| 1261 | } |
| 1262 | hdr->ts.tv_sec = sec; |
| 1263 | hdr->ts.tv_usec = frac; |
| 1264 | |
| 1265 | /* |
| 1266 | * Get a pointer to the packet data. |
| 1267 | */ |
| 1268 | *data = get_from_block_data(&cursor, hdr->caplen, p->errbuf); |
| 1269 | if (*data == NULL) |
| 1270 | return (-1); |
| 1271 | |
| 1272 | if (p->swapped) |
| 1273 | swap_pseudo_headers(p->linktype, hdr, *data); |
| 1274 | |
| 1275 | return (0); |
| 1276 | } |