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.c - libpcap-file-format-specific code from savefile.c |
| 22 | * Extraction/creation by Jeffrey Mogul, DECWRL |
| 23 | * Modified by Steve McCanne, LBL. |
| 24 | * |
| 25 | * Used to save the received packet headers, after filtering, to |
| 26 | * a file, and then read them later. |
| 27 | * The first record in the file contains saved values for the machine |
| 28 | * dependent values so we can print the dump file on any architecture. |
| 29 | */ |
| 30 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 31 | #ifdef HAVE_CONFIG_H |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 32 | #include <config.h> |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 33 | #endif |
| 34 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 35 | #include <pcap-types.h> |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 36 | #ifdef _WIN32 |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 37 | #include <io.h> |
| 38 | #include <fcntl.h> |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 39 | #endif /* _WIN32 */ |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 40 | |
| 41 | #include <errno.h> |
| 42 | #include <memory.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | #include <string.h> |
| 46 | |
| 47 | #include "pcap-int.h" |
| 48 | |
| 49 | #include "pcap-common.h" |
| 50 | |
| 51 | #ifdef HAVE_OS_PROTO_H |
| 52 | #include "os-proto.h" |
| 53 | #endif |
| 54 | |
| 55 | #include "sf-pcap.h" |
| 56 | |
| 57 | /* |
| 58 | * Setting O_BINARY on DOS/Windows is a bit tricky |
| 59 | */ |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 60 | #if defined(_WIN32) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 61 | #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY) |
| 62 | #elif defined(MSDOS) |
| 63 | #if defined(__HIGHC__) |
| 64 | #define SET_BINMODE(f) setmode(f, O_BINARY) |
| 65 | #else |
| 66 | #define SET_BINMODE(f) setmode(fileno(f), O_BINARY) |
| 67 | #endif |
| 68 | #endif |
| 69 | |
| 70 | /* |
| 71 | * Standard libpcap format. |
| 72 | */ |
| 73 | #define TCPDUMP_MAGIC 0xa1b2c3d4 |
| 74 | |
| 75 | /* |
| 76 | * Alexey Kuznetzov's modified libpcap format. |
| 77 | */ |
| 78 | #define KUZNETZOV_TCPDUMP_MAGIC 0xa1b2cd34 |
| 79 | |
| 80 | /* |
| 81 | * Reserved for Francisco Mesquita <francisco.mesquita@radiomovel.pt> |
| 82 | * for another modified format. |
| 83 | */ |
| 84 | #define FMESQUITA_TCPDUMP_MAGIC 0xa1b234cd |
| 85 | |
| 86 | /* |
| 87 | * Navtel Communcations' format, with nanosecond timestamps, |
| 88 | * as per a request from Dumas Hwang <dumas.hwang@navtelcom.com>. |
| 89 | */ |
| 90 | #define NAVTEL_TCPDUMP_MAGIC 0xa12b3c4d |
| 91 | |
| 92 | /* |
| 93 | * Normal libpcap format, except for seconds/nanoseconds timestamps, |
| 94 | * as per a request by Ulf Lamping <ulf.lamping@web.de> |
| 95 | */ |
| 96 | #define NSEC_TCPDUMP_MAGIC 0xa1b23c4d |
| 97 | |
| 98 | /* |
| 99 | * Mechanism for storing information about a capture in the upper |
| 100 | * 6 bits of a linktype value in a capture file. |
| 101 | * |
| 102 | * LT_LINKTYPE_EXT(x) extracts the additional information. |
| 103 | * |
| 104 | * The rest of the bits are for a value describing the link-layer |
| 105 | * value. LT_LINKTYPE(x) extracts that value. |
| 106 | */ |
| 107 | #define LT_LINKTYPE(x) ((x) & 0x03FFFFFF) |
| 108 | #define LT_LINKTYPE_EXT(x) ((x) & 0xFC000000) |
| 109 | |
| 110 | static int pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **datap); |
| 111 | |
| 112 | /* |
| 113 | * Private data for reading pcap savefiles. |
| 114 | */ |
| 115 | typedef enum { |
| 116 | NOT_SWAPPED, |
| 117 | SWAPPED, |
| 118 | MAYBE_SWAPPED |
| 119 | } swapped_type_t; |
| 120 | |
| 121 | typedef enum { |
| 122 | PASS_THROUGH, |
| 123 | SCALE_UP, |
| 124 | SCALE_DOWN |
| 125 | } tstamp_scale_type_t; |
| 126 | |
| 127 | struct pcap_sf { |
| 128 | size_t hdrsize; |
| 129 | swapped_type_t lengths_swapped; |
| 130 | tstamp_scale_type_t scale_type; |
| 131 | }; |
| 132 | |
| 133 | /* |
| 134 | * Check whether this is a pcap savefile and, if it is, extract the |
| 135 | * relevant information from the header. |
| 136 | */ |
| 137 | pcap_t * |
| 138 | pcap_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf, |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 139 | int *err) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 140 | { |
| 141 | struct pcap_file_header hdr; |
| 142 | size_t amt_read; |
| 143 | pcap_t *p; |
| 144 | int swapped = 0; |
| 145 | struct pcap_sf *ps; |
| 146 | |
| 147 | /* |
| 148 | * Assume no read errors. |
| 149 | */ |
| 150 | *err = 0; |
| 151 | |
| 152 | /* |
| 153 | * Check whether the first 4 bytes of the file are the magic |
| 154 | * number for a pcap savefile, or for a byte-swapped pcap |
| 155 | * savefile. |
| 156 | */ |
| 157 | if (magic != TCPDUMP_MAGIC && magic != KUZNETZOV_TCPDUMP_MAGIC && |
| 158 | magic != NSEC_TCPDUMP_MAGIC) { |
| 159 | magic = SWAPLONG(magic); |
| 160 | if (magic != TCPDUMP_MAGIC && magic != KUZNETZOV_TCPDUMP_MAGIC && |
| 161 | magic != NSEC_TCPDUMP_MAGIC) |
| 162 | return (NULL); /* nope */ |
| 163 | swapped = 1; |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * They are. Put the magic number in the header, and read |
| 168 | * the rest of the header. |
| 169 | */ |
| 170 | hdr.magic = magic; |
| 171 | amt_read = fread(((char *)&hdr) + sizeof hdr.magic, 1, |
| 172 | sizeof(hdr) - sizeof(hdr.magic), fp); |
| 173 | if (amt_read != sizeof(hdr) - sizeof(hdr.magic)) { |
| 174 | if (ferror(fp)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 175 | pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, |
| 176 | errno, "error reading dump file"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 177 | } else { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 178 | pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 179 | "truncated dump file; tried to read %lu file header bytes, only got %lu", |
| 180 | (unsigned long)sizeof(hdr), |
| 181 | (unsigned long)amt_read); |
| 182 | } |
| 183 | *err = 1; |
| 184 | return (NULL); |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * If it's a byte-swapped capture file, byte-swap the header. |
| 189 | */ |
| 190 | if (swapped) { |
| 191 | hdr.version_major = SWAPSHORT(hdr.version_major); |
| 192 | hdr.version_minor = SWAPSHORT(hdr.version_minor); |
| 193 | hdr.thiszone = SWAPLONG(hdr.thiszone); |
| 194 | hdr.sigfigs = SWAPLONG(hdr.sigfigs); |
| 195 | hdr.snaplen = SWAPLONG(hdr.snaplen); |
| 196 | hdr.linktype = SWAPLONG(hdr.linktype); |
| 197 | } |
| 198 | |
| 199 | if (hdr.version_major < PCAP_VERSION_MAJOR) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 200 | pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 201 | "archaic pcap savefile format"); |
| 202 | *err = 1; |
| 203 | return (NULL); |
| 204 | } |
| 205 | |
| 206 | /* |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 207 | * currently only versions 2.[0-4] are supported with |
| 208 | * the exception of 543.0 for DG/UX tcpdump. |
| 209 | */ |
| 210 | if (! ((hdr.version_major == PCAP_VERSION_MAJOR && |
| 211 | hdr.version_minor <= PCAP_VERSION_MINOR) || |
| 212 | (hdr.version_major == 543 && |
| 213 | hdr.version_minor == 0))) { |
| 214 | pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 215 | "unsupported pcap savefile version %u.%u", |
| 216 | hdr.version_major, hdr.version_minor); |
| 217 | *err = 1; |
| 218 | return NULL; |
| 219 | } |
| 220 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 221 | /* |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 222 | * OK, this is a good pcap file. |
| 223 | * Allocate a pcap_t for it. |
| 224 | */ |
| 225 | p = pcap_open_offline_common(errbuf, sizeof (struct pcap_sf)); |
| 226 | if (p == NULL) { |
| 227 | /* Allocation failed. */ |
| 228 | *err = 1; |
| 229 | return (NULL); |
| 230 | } |
| 231 | p->swapped = swapped; |
| 232 | p->version_major = hdr.version_major; |
| 233 | p->version_minor = hdr.version_minor; |
| 234 | p->tzoff = hdr.thiszone; |
| 235 | p->snapshot = hdr.snaplen; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 236 | if (p->snapshot <= 0) { |
| 237 | /* |
| 238 | * Bogus snapshot length; use the maximum for this |
| 239 | * link-layer type as a fallback. |
| 240 | * |
| 241 | * XXX - the only reason why snapshot is signed is |
| 242 | * that pcap_snapshot() returns an int, not an |
| 243 | * unsigned int. |
| 244 | */ |
| 245 | p->snapshot = max_snaplen_for_dlt(hdr.linktype); |
| 246 | } |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 247 | p->linktype = linktype_to_dlt(LT_LINKTYPE(hdr.linktype)); |
| 248 | p->linktype_ext = LT_LINKTYPE_EXT(hdr.linktype); |
| 249 | |
| 250 | p->next_packet_op = pcap_next_packet; |
| 251 | |
| 252 | ps = p->priv; |
| 253 | |
| 254 | p->opt.tstamp_precision = precision; |
| 255 | |
| 256 | /* |
| 257 | * Will we need to scale the timestamps to match what the |
| 258 | * user wants? |
| 259 | */ |
| 260 | switch (precision) { |
| 261 | |
| 262 | case PCAP_TSTAMP_PRECISION_MICRO: |
| 263 | if (magic == NSEC_TCPDUMP_MAGIC) { |
| 264 | /* |
| 265 | * The file has nanoseconds, the user |
| 266 | * wants microseconds; scale the |
| 267 | * precision down. |
| 268 | */ |
| 269 | ps->scale_type = SCALE_DOWN; |
| 270 | } else { |
| 271 | /* |
| 272 | * The file has microseconds, the |
| 273 | * user wants microseconds; nothing to do. |
| 274 | */ |
| 275 | ps->scale_type = PASS_THROUGH; |
| 276 | } |
| 277 | break; |
| 278 | |
| 279 | case PCAP_TSTAMP_PRECISION_NANO: |
| 280 | if (magic == NSEC_TCPDUMP_MAGIC) { |
| 281 | /* |
| 282 | * The file has nanoseconds, the |
| 283 | * user wants nanoseconds; nothing to do. |
| 284 | */ |
| 285 | ps->scale_type = PASS_THROUGH; |
| 286 | } else { |
| 287 | /* |
| 288 | * The file has microoseconds, the user |
| 289 | * wants nanoseconds; scale the |
| 290 | * precision up. |
| 291 | */ |
| 292 | ps->scale_type = SCALE_UP; |
| 293 | } |
| 294 | break; |
| 295 | |
| 296 | default: |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 297 | pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 298 | "unknown time stamp resolution %u", precision); |
| 299 | free(p); |
| 300 | *err = 1; |
| 301 | return (NULL); |
| 302 | } |
| 303 | |
| 304 | /* |
| 305 | * We interchanged the caplen and len fields at version 2.3, |
| 306 | * in order to match the bpf header layout. But unfortunately |
| 307 | * some files were written with version 2.3 in their headers |
| 308 | * but without the interchanged fields. |
| 309 | * |
| 310 | * In addition, DG/UX tcpdump writes out files with a version |
| 311 | * number of 543.0, and with the caplen and len fields in the |
| 312 | * pre-2.3 order. |
| 313 | */ |
| 314 | switch (hdr.version_major) { |
| 315 | |
| 316 | case 2: |
| 317 | if (hdr.version_minor < 3) |
| 318 | ps->lengths_swapped = SWAPPED; |
| 319 | else if (hdr.version_minor == 3) |
| 320 | ps->lengths_swapped = MAYBE_SWAPPED; |
| 321 | else |
| 322 | ps->lengths_swapped = NOT_SWAPPED; |
| 323 | break; |
| 324 | |
| 325 | case 543: |
| 326 | ps->lengths_swapped = SWAPPED; |
| 327 | break; |
| 328 | |
| 329 | default: |
| 330 | ps->lengths_swapped = NOT_SWAPPED; |
| 331 | break; |
| 332 | } |
| 333 | |
| 334 | if (magic == KUZNETZOV_TCPDUMP_MAGIC) { |
| 335 | /* |
| 336 | * XXX - the patch that's in some versions of libpcap |
| 337 | * changes the packet header but not the magic number, |
| 338 | * and some other versions with this magic number have |
| 339 | * some extra debugging information in the packet header; |
| 340 | * we'd have to use some hacks^H^H^H^H^Hheuristics to |
| 341 | * detect those variants. |
| 342 | * |
| 343 | * Ethereal does that, but it does so by trying to read |
| 344 | * the first two packets of the file with each of the |
| 345 | * record header formats. That currently means it seeks |
| 346 | * backwards and retries the reads, which doesn't work |
| 347 | * on pipes. We want to be able to read from a pipe, so |
| 348 | * that strategy won't work; we'd have to buffer some |
| 349 | * data ourselves and read from that buffer in order to |
| 350 | * make that work. |
| 351 | */ |
| 352 | ps->hdrsize = sizeof(struct pcap_sf_patched_pkthdr); |
| 353 | |
| 354 | if (p->linktype == DLT_EN10MB) { |
| 355 | /* |
| 356 | * This capture might have been done in raw mode |
| 357 | * or cooked mode. |
| 358 | * |
| 359 | * If it was done in cooked mode, p->snapshot was |
| 360 | * passed to recvfrom() as the buffer size, meaning |
| 361 | * that the most packet data that would be copied |
| 362 | * would be p->snapshot. However, a faked Ethernet |
| 363 | * header would then have been added to it, so the |
| 364 | * most data that would be in a packet in the file |
| 365 | * would be p->snapshot + 14. |
| 366 | * |
| 367 | * We can't easily tell whether the capture was done |
| 368 | * in raw mode or cooked mode, so we'll assume it was |
| 369 | * cooked mode, and add 14 to the snapshot length. |
| 370 | * That means that, for a raw capture, the snapshot |
| 371 | * length will be misleading if you use it to figure |
| 372 | * out why a capture doesn't have all the packet data, |
| 373 | * but there's not much we can do to avoid that. |
| 374 | */ |
| 375 | p->snapshot += 14; |
| 376 | } |
| 377 | } else |
| 378 | ps->hdrsize = sizeof(struct pcap_sf_pkthdr); |
| 379 | |
| 380 | /* |
| 381 | * Allocate a buffer for the packet data. |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 382 | * Choose the minimum of the file's snapshot length and 2K bytes; |
| 383 | * that should be enough for most network packets - we'll grow it |
| 384 | * if necessary. That way, we don't allocate a huge chunk of |
| 385 | * memory just because there's a huge snapshot length, as the |
| 386 | * snapshot length might be larger than the size of the largest |
| 387 | * packet. |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 388 | */ |
| 389 | p->bufsize = p->snapshot; |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 390 | if (p->bufsize > 2048) |
| 391 | p->bufsize = 2048; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 392 | p->buffer = malloc(p->bufsize); |
| 393 | if (p->buffer == NULL) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 394 | pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "out of memory"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 395 | free(p); |
| 396 | *err = 1; |
| 397 | return (NULL); |
| 398 | } |
| 399 | |
| 400 | p->cleanup_op = sf_cleanup; |
| 401 | |
| 402 | return (p); |
| 403 | } |
| 404 | |
| 405 | /* |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 406 | * Grow the packet buffer to the specified size. |
| 407 | */ |
| 408 | static int |
| 409 | grow_buffer(pcap_t *p, u_int bufsize) |
| 410 | { |
| 411 | void *bigger_buffer; |
| 412 | |
| 413 | bigger_buffer = realloc(p->buffer, bufsize); |
| 414 | if (bigger_buffer == NULL) { |
| 415 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "out of memory"); |
| 416 | return (0); |
| 417 | } |
| 418 | p->buffer = bigger_buffer; |
| 419 | p->bufsize = bufsize; |
| 420 | return (1); |
| 421 | } |
| 422 | |
| 423 | /* |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 424 | * Read and return the next packet from the savefile. Return the header |
| 425 | * in hdr and a pointer to the contents in data. Return 0 on success, 1 |
| 426 | * if there were no more packets, and -1 on an error. |
| 427 | */ |
| 428 | static int |
| 429 | pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data) |
| 430 | { |
| 431 | struct pcap_sf *ps = p->priv; |
| 432 | struct pcap_sf_patched_pkthdr sf_hdr; |
| 433 | FILE *fp = p->rfile; |
| 434 | size_t amt_read; |
| 435 | bpf_u_int32 t; |
| 436 | |
| 437 | /* |
| 438 | * Read the packet header; the structure we use as a buffer |
| 439 | * is the longer structure for files generated by the patched |
| 440 | * libpcap, but if the file has the magic number for an |
| 441 | * unpatched libpcap we only read as many bytes as the regular |
| 442 | * header has. |
| 443 | */ |
| 444 | amt_read = fread(&sf_hdr, 1, ps->hdrsize, fp); |
| 445 | if (amt_read != ps->hdrsize) { |
| 446 | if (ferror(fp)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 447 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 448 | errno, "error reading dump file"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 449 | return (-1); |
| 450 | } else { |
| 451 | if (amt_read != 0) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 452 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 453 | "truncated dump file; tried to read %lu header bytes, only got %lu", |
| 454 | (unsigned long)ps->hdrsize, |
| 455 | (unsigned long)amt_read); |
| 456 | return (-1); |
| 457 | } |
| 458 | /* EOF */ |
| 459 | return (1); |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | if (p->swapped) { |
| 464 | /* these were written in opposite byte order */ |
| 465 | hdr->caplen = SWAPLONG(sf_hdr.caplen); |
| 466 | hdr->len = SWAPLONG(sf_hdr.len); |
| 467 | hdr->ts.tv_sec = SWAPLONG(sf_hdr.ts.tv_sec); |
| 468 | hdr->ts.tv_usec = SWAPLONG(sf_hdr.ts.tv_usec); |
| 469 | } else { |
| 470 | hdr->caplen = sf_hdr.caplen; |
| 471 | hdr->len = sf_hdr.len; |
| 472 | hdr->ts.tv_sec = sf_hdr.ts.tv_sec; |
| 473 | hdr->ts.tv_usec = sf_hdr.ts.tv_usec; |
| 474 | } |
| 475 | |
| 476 | switch (ps->scale_type) { |
| 477 | |
| 478 | case PASS_THROUGH: |
| 479 | /* |
| 480 | * Just pass the time stamp through. |
| 481 | */ |
| 482 | break; |
| 483 | |
| 484 | case SCALE_UP: |
| 485 | /* |
| 486 | * File has microseconds, user wants nanoseconds; convert |
| 487 | * it. |
| 488 | */ |
| 489 | hdr->ts.tv_usec = hdr->ts.tv_usec * 1000; |
| 490 | break; |
| 491 | |
| 492 | case SCALE_DOWN: |
| 493 | /* |
| 494 | * File has nanoseconds, user wants microseconds; convert |
| 495 | * it. |
| 496 | */ |
| 497 | hdr->ts.tv_usec = hdr->ts.tv_usec / 1000; |
| 498 | break; |
| 499 | } |
| 500 | |
| 501 | /* Swap the caplen and len fields, if necessary. */ |
| 502 | switch (ps->lengths_swapped) { |
| 503 | |
| 504 | case NOT_SWAPPED: |
| 505 | break; |
| 506 | |
| 507 | case MAYBE_SWAPPED: |
| 508 | if (hdr->caplen <= hdr->len) { |
| 509 | /* |
| 510 | * The captured length is <= the actual length, |
| 511 | * so presumably they weren't swapped. |
| 512 | */ |
| 513 | break; |
| 514 | } |
| 515 | /* FALLTHROUGH */ |
| 516 | |
| 517 | case SWAPPED: |
| 518 | t = hdr->caplen; |
| 519 | hdr->caplen = hdr->len; |
| 520 | hdr->len = t; |
| 521 | break; |
| 522 | } |
| 523 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 524 | /* |
| 525 | * Is the packet bigger than we consider sane? |
| 526 | */ |
| 527 | if (hdr->caplen > max_snaplen_for_dlt(p->linktype)) { |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 528 | /* |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 529 | * Yes. This may be a damaged or fuzzed file. |
| 530 | * |
| 531 | * Is it bigger than the snapshot length? |
| 532 | * (We don't treat that as an error if it's not |
| 533 | * bigger than the maximum we consider sane; see |
| 534 | * below.) |
| 535 | */ |
| 536 | if (hdr->caplen > (bpf_u_int32)p->snapshot) { |
| 537 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 538 | "invalid packet capture length %u, bigger than " |
| 539 | "snaplen of %d", hdr->caplen, p->snapshot); |
| 540 | } else { |
| 541 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 542 | "invalid packet capture length %u, bigger than " |
| 543 | "maximum of %u", hdr->caplen, |
| 544 | max_snaplen_for_dlt(p->linktype)); |
| 545 | } |
| 546 | return (-1); |
| 547 | } |
| 548 | |
| 549 | if (hdr->caplen > (bpf_u_int32)p->snapshot) { |
| 550 | /* |
| 551 | * The packet is bigger than the snapshot length |
| 552 | * for this file. |
| 553 | * |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 554 | * This can happen due to Solaris 2.3 systems tripping |
| 555 | * over the BUFMOD problem and not setting the snapshot |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 556 | * length correctly in the savefile header. |
| 557 | * |
| 558 | * libpcap 0.4 and later on Solaris 2.3 should set the |
| 559 | * snapshot length correctly in the pcap file header, |
| 560 | * even though they don't set a snapshot length in bufmod |
| 561 | * (the buggy bufmod chops off the *beginning* of the |
| 562 | * packet if a snapshot length is specified); they should |
| 563 | * also reduce the captured length, as supplied to the |
| 564 | * per-packet callback, to the snapshot length if it's |
| 565 | * greater than the snapshot length, so the code using |
| 566 | * libpcap should see the packet cut off at the snapshot |
| 567 | * length, even though the full packet is copied up to |
| 568 | * userland. |
| 569 | * |
| 570 | * However, perhaps some versions of libpcap failed to |
| 571 | * set the snapshot length currectly in the file header |
| 572 | * or the per-packet header, or perhaps this is a |
| 573 | * corrupted safefile or a savefile built/modified by a |
| 574 | * fuzz tester, so we check anyway. We grow the buffer |
| 575 | * to be big enough for the snapshot length, read up |
| 576 | * to the snapshot length, discard the rest of the |
| 577 | * packet, and report the snapshot length as the captured |
| 578 | * length; we don't want to hand our caller a packet |
| 579 | * bigger than the snapshot length, because they might |
| 580 | * be assuming they'll never be handed such a packet, |
| 581 | * and might copy the packet into a snapshot-length- |
| 582 | * sized buffer, assuming it'll fit. |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 583 | */ |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 584 | size_t bytes_to_discard; |
| 585 | size_t bytes_to_read, bytes_read; |
| 586 | char discard_buf[4096]; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 587 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 588 | if (hdr->caplen > p->bufsize) { |
| 589 | /* |
| 590 | * Grow the buffer to the snapshot length. |
| 591 | */ |
| 592 | if (!grow_buffer(p, p->snapshot)) |
| 593 | return (-1); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 594 | } |
| 595 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 596 | /* |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 597 | * Read the first p->snapshot bytes into the buffer. |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 598 | */ |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 599 | amt_read = fread(p->buffer, 1, p->snapshot, fp); |
| 600 | if (amt_read != (bpf_u_int32)p->snapshot) { |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 601 | if (ferror(fp)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 602 | pcap_fmt_errmsg_for_errno(p->errbuf, |
| 603 | PCAP_ERRBUF_SIZE, errno, |
| 604 | "error reading dump file"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 605 | } else { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 606 | /* |
| 607 | * Yes, this uses hdr->caplen; technically, |
| 608 | * it's true, because we would try to read |
| 609 | * and discard the rest of those bytes, and |
| 610 | * that would fail because we got EOF before |
| 611 | * the read finished. |
| 612 | */ |
| 613 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 614 | "truncated dump file; tried to read %u captured bytes, only got %lu", |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 615 | p->snapshot, (unsigned long)amt_read); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 616 | } |
| 617 | return (-1); |
| 618 | } |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 619 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 620 | /* |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 621 | * Now read and discard what's left. |
| 622 | */ |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 623 | bytes_to_discard = hdr->caplen - p->snapshot; |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 624 | bytes_read = amt_read; |
| 625 | while (bytes_to_discard != 0) { |
| 626 | bytes_to_read = bytes_to_discard; |
| 627 | if (bytes_to_read > sizeof (discard_buf)) |
| 628 | bytes_to_read = sizeof (discard_buf); |
| 629 | amt_read = fread(discard_buf, 1, bytes_to_read, fp); |
| 630 | bytes_read += amt_read; |
| 631 | if (amt_read != bytes_to_read) { |
| 632 | if (ferror(fp)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 633 | pcap_fmt_errmsg_for_errno(p->errbuf, |
| 634 | PCAP_ERRBUF_SIZE, errno, |
| 635 | "error reading dump file"); |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 636 | } else { |
| 637 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 638 | "truncated dump file; tried to read %u captured bytes, only got %lu", |
| 639 | hdr->caplen, (unsigned long)bytes_read); |
| 640 | } |
| 641 | return (-1); |
| 642 | } |
| 643 | bytes_to_discard -= amt_read; |
| 644 | } |
| 645 | |
| 646 | /* |
| 647 | * Adjust caplen accordingly, so we don't get confused later |
| 648 | * as to how many bytes we have to play with. |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 649 | */ |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 650 | hdr->caplen = p->snapshot; |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 651 | } else { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 652 | if (hdr->caplen > p->bufsize) { |
| 653 | /* |
| 654 | * Grow the buffer to the next power of 2, or |
| 655 | * the snaplen, whichever is lower. |
| 656 | */ |
| 657 | u_int new_bufsize; |
| 658 | |
| 659 | new_bufsize = hdr->caplen; |
| 660 | /* |
| 661 | * http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2 |
| 662 | */ |
| 663 | new_bufsize--; |
| 664 | new_bufsize |= new_bufsize >> 1; |
| 665 | new_bufsize |= new_bufsize >> 2; |
| 666 | new_bufsize |= new_bufsize >> 4; |
| 667 | new_bufsize |= new_bufsize >> 8; |
| 668 | new_bufsize |= new_bufsize >> 16; |
| 669 | new_bufsize++; |
| 670 | |
| 671 | if (new_bufsize > (u_int)p->snapshot) |
| 672 | new_bufsize = p->snapshot; |
| 673 | |
| 674 | if (!grow_buffer(p, new_bufsize)) |
| 675 | return (-1); |
| 676 | } |
| 677 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 678 | /* read the packet itself */ |
| 679 | amt_read = fread(p->buffer, 1, hdr->caplen, fp); |
| 680 | if (amt_read != hdr->caplen) { |
| 681 | if (ferror(fp)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 682 | pcap_fmt_errmsg_for_errno(p->errbuf, |
| 683 | PCAP_ERRBUF_SIZE, errno, |
| 684 | "error reading dump file"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 685 | } else { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 686 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 687 | "truncated dump file; tried to read %u captured bytes, only got %lu", |
| 688 | hdr->caplen, (unsigned long)amt_read); |
| 689 | } |
| 690 | return (-1); |
| 691 | } |
| 692 | } |
| 693 | *data = p->buffer; |
| 694 | |
| 695 | if (p->swapped) |
| 696 | swap_pseudo_headers(p->linktype, hdr, *data); |
| 697 | |
| 698 | return (0); |
| 699 | } |
| 700 | |
| 701 | static int |
| 702 | sf_write_header(pcap_t *p, FILE *fp, int linktype, int thiszone, int snaplen) |
| 703 | { |
| 704 | struct pcap_file_header hdr; |
| 705 | |
| 706 | hdr.magic = p->opt.tstamp_precision == PCAP_TSTAMP_PRECISION_NANO ? NSEC_TCPDUMP_MAGIC : TCPDUMP_MAGIC; |
| 707 | hdr.version_major = PCAP_VERSION_MAJOR; |
| 708 | hdr.version_minor = PCAP_VERSION_MINOR; |
| 709 | |
| 710 | hdr.thiszone = thiszone; |
| 711 | hdr.snaplen = snaplen; |
| 712 | hdr.sigfigs = 0; |
| 713 | hdr.linktype = linktype; |
| 714 | |
| 715 | if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1) |
| 716 | return (-1); |
| 717 | |
| 718 | return (0); |
| 719 | } |
| 720 | |
| 721 | /* |
| 722 | * Output a packet to the initialized dump file. |
| 723 | */ |
| 724 | void |
| 725 | pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) |
| 726 | { |
| 727 | register FILE *f; |
| 728 | struct pcap_sf_pkthdr sf_hdr; |
| 729 | |
| 730 | f = (FILE *)user; |
| 731 | sf_hdr.ts.tv_sec = h->ts.tv_sec; |
| 732 | sf_hdr.ts.tv_usec = h->ts.tv_usec; |
| 733 | sf_hdr.caplen = h->caplen; |
| 734 | sf_hdr.len = h->len; |
| 735 | /* XXX we should check the return status */ |
| 736 | (void)fwrite(&sf_hdr, sizeof(sf_hdr), 1, f); |
| 737 | (void)fwrite(sp, h->caplen, 1, f); |
| 738 | } |
| 739 | |
| 740 | static pcap_dumper_t * |
| 741 | pcap_setup_dump(pcap_t *p, int linktype, FILE *f, const char *fname) |
| 742 | { |
| 743 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 744 | #if defined(_WIN32) || defined(MSDOS) |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 745 | /* |
| 746 | * If we're writing to the standard output, put it in binary |
| 747 | * mode, as savefiles are binary files. |
| 748 | * |
| 749 | * Otherwise, we turn off buffering. |
| 750 | * XXX - why? And why not on the standard output? |
| 751 | */ |
| 752 | if (f == stdout) |
| 753 | SET_BINMODE(f); |
| 754 | else |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 755 | setvbuf(f, NULL, _IONBF, 0); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 756 | #endif |
| 757 | if (sf_write_header(p, f, linktype, p->tzoff, p->snapshot) == -1) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 758 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 759 | errno, "Can't write to %s", fname); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 760 | if (f != stdout) |
| 761 | (void)fclose(f); |
| 762 | return (NULL); |
| 763 | } |
| 764 | return ((pcap_dumper_t *)f); |
| 765 | } |
| 766 | |
| 767 | /* |
| 768 | * Initialize so that sf_write() will output to the file named 'fname'. |
| 769 | */ |
| 770 | pcap_dumper_t * |
| 771 | pcap_dump_open(pcap_t *p, const char *fname) |
| 772 | { |
| 773 | FILE *f; |
| 774 | int linktype; |
| 775 | |
| 776 | /* |
| 777 | * If this pcap_t hasn't been activated, it doesn't have a |
| 778 | * link-layer type, so we can't use it. |
| 779 | */ |
| 780 | if (!p->activated) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 781 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 782 | "%s: not-yet-activated pcap_t passed to pcap_dump_open", |
| 783 | fname); |
| 784 | return (NULL); |
| 785 | } |
| 786 | linktype = dlt_to_linktype(p->linktype); |
| 787 | if (linktype == -1) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 788 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 789 | "%s: link-layer type %d isn't supported in savefiles", |
| 790 | fname, p->linktype); |
| 791 | return (NULL); |
| 792 | } |
| 793 | linktype |= p->linktype_ext; |
| 794 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 795 | if (fname == NULL) { |
| 796 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 797 | "A null pointer was supplied as the file name"); |
| 798 | return NULL; |
| 799 | } |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 800 | if (fname[0] == '-' && fname[1] == '\0') { |
| 801 | f = stdout; |
| 802 | fname = "standard output"; |
| 803 | } else { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 804 | /* |
| 805 | * "b" is supported as of C90, so *all* UN*Xes should |
| 806 | * support it, even though it does nothing. It's |
| 807 | * required on Windows, as the file is a binary file |
| 808 | * and must be written in binary mode. |
| 809 | */ |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 810 | f = fopen(fname, "wb"); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 811 | if (f == NULL) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 812 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 813 | errno, "%s", fname); |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 814 | return (NULL); |
| 815 | } |
| 816 | } |
| 817 | return (pcap_setup_dump(p, linktype, f, fname)); |
| 818 | } |
| 819 | |
| 820 | /* |
| 821 | * Initialize so that sf_write() will output to the given stream. |
| 822 | */ |
| 823 | pcap_dumper_t * |
| 824 | pcap_dump_fopen(pcap_t *p, FILE *f) |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 825 | { |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 826 | int linktype; |
| 827 | |
| 828 | linktype = dlt_to_linktype(p->linktype); |
| 829 | if (linktype == -1) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 830 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 831 | "stream: link-layer type %d isn't supported in savefiles", |
| 832 | p->linktype); |
| 833 | return (NULL); |
| 834 | } |
| 835 | linktype |= p->linktype_ext; |
| 836 | |
| 837 | return (pcap_setup_dump(p, linktype, f, "stream")); |
| 838 | } |
| 839 | |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 840 | pcap_dumper_t * |
| 841 | pcap_dump_open_append(pcap_t *p, const char *fname) |
| 842 | { |
| 843 | FILE *f; |
| 844 | int linktype; |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 845 | size_t amt_read; |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 846 | struct pcap_file_header ph; |
| 847 | |
| 848 | linktype = dlt_to_linktype(p->linktype); |
| 849 | if (linktype == -1) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 850 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 851 | "%s: link-layer type %d isn't supported in savefiles", |
| 852 | fname, linktype); |
| 853 | return (NULL); |
| 854 | } |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 855 | |
| 856 | if (fname == NULL) { |
| 857 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
| 858 | "A null pointer was supplied as the file name"); |
| 859 | return NULL; |
| 860 | } |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 861 | if (fname[0] == '-' && fname[1] == '\0') |
| 862 | return (pcap_setup_dump(p, linktype, stdout, "standard output")); |
| 863 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 864 | /* |
| 865 | * "b" is supported as of C90, so *all* UN*Xes should support it, |
| 866 | * even though it does nothing. It's required on Windows, as the |
| 867 | * file is a binary file and must be read in binary mode. |
| 868 | */ |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 869 | f = fopen(fname, "rb+"); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 870 | if (f == NULL) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 871 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 872 | errno, "%s", fname); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 873 | return (NULL); |
| 874 | } |
| 875 | |
| 876 | /* |
| 877 | * Try to read a pcap header. |
| 878 | */ |
| 879 | amt_read = fread(&ph, 1, sizeof (ph), f); |
| 880 | if (amt_read != sizeof (ph)) { |
| 881 | if (ferror(f)) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 882 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 883 | errno, "%s", fname); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 884 | fclose(f); |
| 885 | return (NULL); |
| 886 | } else if (feof(f) && amt_read > 0) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 887 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 888 | "%s: truncated pcap file header", fname); |
| 889 | fclose(f); |
| 890 | return (NULL); |
| 891 | } |
| 892 | } |
| 893 | |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 894 | #if defined(_WIN32) || defined(MSDOS) |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 895 | /* |
| 896 | * We turn off buffering. |
| 897 | * XXX - why? And why not on the standard output? |
| 898 | */ |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 899 | setvbuf(f, NULL, _IONBF, 0); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 900 | #endif |
| 901 | |
| 902 | /* |
| 903 | * If a header is already present and: |
| 904 | * |
| 905 | * it's not for a pcap file of the appropriate resolution |
| 906 | * and the right byte order for this machine; |
| 907 | * |
| 908 | * the link-layer header types don't match; |
| 909 | * |
| 910 | * the snapshot lengths don't match; |
| 911 | * |
| 912 | * return an error. |
| 913 | */ |
| 914 | if (amt_read > 0) { |
| 915 | /* |
| 916 | * A header is already present. |
| 917 | * Do the checks. |
| 918 | */ |
| 919 | switch (ph.magic) { |
| 920 | |
| 921 | case TCPDUMP_MAGIC: |
| 922 | if (p->opt.tstamp_precision != PCAP_TSTAMP_PRECISION_MICRO) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 923 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 924 | "%s: different time stamp precision, cannot append to file", fname); |
| 925 | fclose(f); |
| 926 | return (NULL); |
| 927 | } |
| 928 | break; |
| 929 | |
| 930 | case NSEC_TCPDUMP_MAGIC: |
| 931 | if (p->opt.tstamp_precision != PCAP_TSTAMP_PRECISION_NANO) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 932 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 933 | "%s: different time stamp precision, cannot append to file", fname); |
| 934 | fclose(f); |
| 935 | return (NULL); |
| 936 | } |
| 937 | break; |
| 938 | |
| 939 | case SWAPLONG(TCPDUMP_MAGIC): |
| 940 | case SWAPLONG(NSEC_TCPDUMP_MAGIC): |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 941 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 942 | "%s: different byte order, cannot append to file", fname); |
| 943 | fclose(f); |
| 944 | return (NULL); |
| 945 | |
| 946 | case KUZNETZOV_TCPDUMP_MAGIC: |
| 947 | case SWAPLONG(KUZNETZOV_TCPDUMP_MAGIC): |
| 948 | case NAVTEL_TCPDUMP_MAGIC: |
| 949 | case SWAPLONG(NAVTEL_TCPDUMP_MAGIC): |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 950 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 951 | "%s: not a pcap file to which we can append", fname); |
| 952 | fclose(f); |
| 953 | return (NULL); |
| 954 | |
| 955 | default: |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 956 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 957 | "%s: not a pcap file", fname); |
| 958 | fclose(f); |
| 959 | return (NULL); |
| 960 | } |
| 961 | |
| 962 | /* |
| 963 | * Good version? |
| 964 | */ |
| 965 | if (ph.version_major != PCAP_VERSION_MAJOR || |
| 966 | ph.version_minor != PCAP_VERSION_MINOR) { |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 967 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 968 | "%s: version is %u.%u, cannot append to file", fname, |
| 969 | ph.version_major, ph.version_minor); |
| 970 | fclose(f); |
| 971 | return (NULL); |
| 972 | } |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 973 | if ((bpf_u_int32)linktype != ph.linktype) { |
| 974 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 975 | "%s: different linktype, cannot append to file", fname); |
| 976 | fclose(f); |
| 977 | return (NULL); |
| 978 | } |
Elliott Hughes | 965a4b5 | 2017-05-15 10:37:39 -0700 | [diff] [blame] | 979 | if ((bpf_u_int32)p->snapshot != ph.snaplen) { |
| 980 | pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 981 | "%s: different snaplen, cannot append to file", fname); |
| 982 | fclose(f); |
| 983 | return (NULL); |
| 984 | } |
| 985 | } else { |
| 986 | /* |
| 987 | * A header isn't present; attempt to write it. |
| 988 | */ |
| 989 | if (sf_write_header(p, f, linktype, p->tzoff, p->snapshot) == -1) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 990 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 991 | errno, "Can't write to %s", fname); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 992 | (void)fclose(f); |
| 993 | return (NULL); |
| 994 | } |
| 995 | } |
| 996 | |
| 997 | /* |
| 998 | * Start writing at the end of the file. |
| 999 | */ |
| 1000 | if (fseek(f, 0, SEEK_END) == -1) { |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 1001 | pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE, |
| 1002 | errno, "Can't seek to end of %s", fname); |
Elliott Hughes | d8845d7 | 2015-10-19 18:07:04 -0700 | [diff] [blame] | 1003 | (void)fclose(f); |
| 1004 | return (NULL); |
| 1005 | } |
| 1006 | return ((pcap_dumper_t *)f); |
| 1007 | } |
| 1008 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1009 | FILE * |
| 1010 | pcap_dump_file(pcap_dumper_t *p) |
| 1011 | { |
| 1012 | return ((FILE *)p); |
| 1013 | } |
| 1014 | |
| 1015 | long |
| 1016 | pcap_dump_ftell(pcap_dumper_t *p) |
| 1017 | { |
| 1018 | return (ftell((FILE *)p)); |
| 1019 | } |
| 1020 | |
Haibo Huang | 165065a | 2018-07-23 17:26:52 -0700 | [diff] [blame] | 1021 | #if defined(HAVE_FSEEKO) |
| 1022 | /* |
| 1023 | * We have fseeko(), so we have ftello(). |
| 1024 | * If we have large file support (files larger than 2^31-1 bytes), |
| 1025 | * ftello() will give us a current file position with more than 32 |
| 1026 | * bits. |
| 1027 | */ |
| 1028 | int64_t |
| 1029 | pcap_dump_ftell64(pcap_dumper_t *p) |
| 1030 | { |
| 1031 | return (ftello((FILE *)p)); |
| 1032 | } |
| 1033 | #elif defined(_MSC_VER) |
| 1034 | /* |
| 1035 | * We have Visual Studio; we support only 2005 and later, so we have |
| 1036 | * _ftelli64(). |
| 1037 | */ |
| 1038 | int64_t |
| 1039 | pcap_dump_ftell64(pcap_dumper_t *p) |
| 1040 | { |
| 1041 | return (_ftelli64((FILE *)p)); |
| 1042 | } |
| 1043 | #else |
| 1044 | /* |
| 1045 | * We don't have ftello() or _ftelli64(), so fall back on ftell(). |
| 1046 | * Either long is 64 bits, in which case ftell() should suffice, |
| 1047 | * or this is probably an older 32-bit UN*X without large file |
| 1048 | * support, which means you'll probably get errors trying to |
| 1049 | * write files > 2^31-1, so it won't matter anyway. |
| 1050 | * |
| 1051 | * XXX - what about MinGW? |
| 1052 | */ |
| 1053 | int64_t |
| 1054 | pcap_dump_ftell64(pcap_dumper_t *p) |
| 1055 | { |
| 1056 | return (ftell((FILE *)p)); |
| 1057 | } |
| 1058 | #endif |
| 1059 | |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1060 | int |
| 1061 | pcap_dump_flush(pcap_dumper_t *p) |
| 1062 | { |
| 1063 | |
| 1064 | if (fflush((FILE *)p) == EOF) |
| 1065 | return (-1); |
| 1066 | else |
| 1067 | return (0); |
| 1068 | } |
| 1069 | |
| 1070 | void |
| 1071 | pcap_dump_close(pcap_dumper_t *p) |
| 1072 | { |
| 1073 | |
| 1074 | #ifdef notyet |
| 1075 | if (ferror((FILE *)p)) |
| 1076 | return-an-error; |
| 1077 | /* XXX should check return from fclose() too */ |
| 1078 | #endif |
| 1079 | (void)fclose((FILE *)p); |
| 1080 | } |