external/bsd/libpcap/dist/savefile.c

   1 /*      $NetBSD: savefile.c,v 1.3 2015/03/31 21:39:42 christos Exp $    */
   2
   3 /*
   4  * Copyright (c) 1993, 1994, 1995, 1996, 1997
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that: (1) source code distributions
   9  * retain the above copyright notice and this paragraph in its entirety, (2)
  10  * distributions including binary code include the above copyright notice and
  11  * this paragraph in its entirety in the documentation or other materials
  12  * provided with the distribution, and (3) all advertising materials mentioning
  13  * features or use of this software display the following acknowledgement:
  14  * ``This product includes software developed by the University of California,
  15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  16  * the University nor the names of its contributors may be used to endorse
  17  * or promote products derived from this software without specific prior
  18  * written permission.
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  22  *
  23  * savefile.c - supports offline use of tcpdump
  24  *      Extraction/creation by Jeffrey Mogul, DECWRL
  25  *      Modified by Steve McCanne, LBL.
  26  *
  27  * Used to save the received packet headers, after filtering, to
  28  * a file, and then read them later.
  29  * The first record in the file contains saved values for the machine
  30  * dependent values so we can print the dump file on any architecture.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __RCSID("$NetBSD: savefile.c,v 1.3 2015/03/31 21:39:42 christos Exp $");
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include "config.h"
  38 #endif
  39
  40 #ifdef WIN32
  41 #include <pcap-stdinc.h>
  42 #else /* WIN32 */
  43 #if HAVE_INTTYPES_H
  44 #include <inttypes.h>
  45 #elif HAVE_STDINT_H
  46 #include <stdint.h>
  47 #endif
  48 #ifdef HAVE_SYS_BITYPES_H
  49 #include <sys/bitypes.h>
  50 #endif
  51 #include <sys/types.h>
  52 #endif /* WIN32 */
  53
  54 #include <errno.h>
  55 #include <memory.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59
  60 #include "pcap-int.h"
  61 #include "pcap/usb.h"
  62
  63 #ifdef HAVE_OS_PROTO_H
  64 #include "os-proto.h"
  65 #endif
  66
  67 #include "sf-pcap.h"
  68 #include "sf-pcap-ng.h"
  69
  70 /*
  71  * Setting O_BINARY on DOS/Windows is a bit tricky
  72  */
  73 #if defined(WIN32)
  74   #define SET_BINMODE(f)  _setmode(_fileno(f), _O_BINARY)
  75 #elif defined(MSDOS)
  76   #if defined(__HIGHC__)
  77   #define SET_BINMODE(f)  setmode(f, O_BINARY)
  78   #else
  79   #define SET_BINMODE(f)  setmode(fileno(f), O_BINARY)
  80   #endif
  81 #endif
  82
  83 static int
  84 sf_getnonblock(pcap_t *p, char *errbuf)
  85 {
  86         /*
  87          * This is a savefile, not a live capture file, so never say
  88          * it's in non-blocking mode.
  89          */
  90         return (0);
  91 }
  92
  93 static int
  94 sf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
  95 {
  96         /*
  97          * This is a savefile, not a live capture file, so reject
  98          * requests to put it in non-blocking mode.  (If it's a
  99          * pipe, it could be put in non-blocking mode, but that
 100          * would significantly complicate the code to read packets,
 101          * as it would have to handle reading partial packets and
 102          * keeping the state of the read.)
 103          */
 104         snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 105             "Savefiles cannot be put into non-blocking mode");
 106         return (-1);
 107 }
 108
 109 static int
 110 sf_stats(pcap_t *p, struct pcap_stat *ps)
 111 {
 112         snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 113             "Statistics aren't available from savefiles");
 114         return (-1);
 115 }
 116
 117 #ifdef WIN32
 118 static int
 119 sf_setbuff(pcap_t *p, int dim)
 120 {
 121         snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 122             "The kernel buffer size cannot be set while reading from a file");
 123         return (-1);
 124 }
 125
 126 static int
 127 sf_setmode(pcap_t *p, int mode)
 128 {
 129         snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 130             "impossible to set mode while reading from a file");
 131         return (-1);
 132 }
 133
 134 static int
 135 sf_setmintocopy(pcap_t *p, int size)
 136 {
 137         snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 138             "The mintocopy parameter cannot be set while reading from a file");
 139         return (-1);
 140 }
 141 #endif
 142
 143 static int
 144 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
 145 {
 146         strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
 147             PCAP_ERRBUF_SIZE);
 148         return (-1);
 149 }
 150
 151 /*
 152  * Set direction flag: Which packets do we accept on a forwarding
 153  * single device? IN, OUT or both?
 154  */
 155 static int
 156 sf_setdirection(pcap_t *p, pcap_direction_t d)
 157 {
 158         snprintf(p->errbuf, sizeof(p->errbuf),
 159             "Setting direction is not supported on savefiles");
 160         return (-1);
 161 }
 162
 163 void
 164 sf_cleanup(pcap_t *p)
 165 {
 166         if (p->rfile != stdin)
 167                 (void)fclose(p->rfile);
 168         if (p->buffer != NULL)
 169                 free(p->buffer);
 170         pcap_freecode(&p->fcode);
 171 }
 172
 173 pcap_t *
 174 pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,
 175     char *errbuf)
 176 {
 177         FILE *fp;
 178         pcap_t *p;
 179
 180         if (fname[0] == '-' && fname[1] == '\0')
 181         {
 182                 fp = stdin;
 183 #if defined(WIN32) || defined(MSDOS)
 184                 /*
 185                  * We're reading from the standard input, so put it in binary
 186                  * mode, as savefiles are binary files.
 187                  */
 188                 SET_BINMODE(fp);
 189 #endif
 190         }
 191         else {
 192 #if !defined(WIN32) && !defined(MSDOS)
 193                 fp = fopen(fname, "r");
 194 #else
 195                 fp = fopen(fname, "rb");
 196 #endif
 197                 if (fp == NULL) {
 198                         snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
 199                             pcap_strerror(errno));
 200                         return (NULL);
 201                 }
 202         }
 203         p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);
 204         if (p == NULL) {
 205                 if (fp != stdin)
 206                         fclose(fp);
 207         }
 208         return (p);
 209 }
 210
 211 pcap_t *
 212 pcap_open_offline(const char *fname, char *errbuf)
 213 {
 214         return (pcap_open_offline_with_tstamp_precision(fname,
 215             PCAP_TSTAMP_PRECISION_MICRO, errbuf));
 216 }
 217
 218 #ifdef WIN32
 219 pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,
 220     char *errbuf)
 221 {
 222         int fd;
 223         FILE *file;
 224
 225         fd = _open_osfhandle(osfd, _O_RDONLY);
 226         if ( fd < 0 )
 227         {
 228                 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
 229                 return NULL;
 230         }
 231
 232         file = _fdopen(fd, "rb");
 233         if ( file == NULL )
 234         {
 235                 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
 236                 return NULL;
 237         }
 238
 239         return pcap_fopen_offline_with_tstamp_precision(file, precision,
 240             errbuf);
 241 }
 242
 243 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
 244 {
 245         return pcap_hopen_offline_with_tstamp_precision(osfd,
 246             PCAP_TSTAMP_PRECISION_MICRO, errbuf);
 247 }
 248 #endif
 249
 250 static pcap_t *(*check_headers[])(bpf_u_int32, FILE *, u_int, char *, int *) = {
 251         pcap_check_header,
 252         pcap_ng_check_header
 253 };
 254
 255 #define N_FILE_TYPES    (sizeof check_headers / sizeof check_headers[0])
 256
 257 #ifdef WIN32
 258 static
 259 #endif
 260 pcap_t *
 261 pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
 262     char *errbuf)
 263 {
 264         register pcap_t *p;
 265         bpf_u_int32 magic;
 266         size_t amt_read;
 267         u_int i;
 268         int err;
 269
 270         /*
 271          * Read the first 4 bytes of the file; the network analyzer dump
 272          * file formats we support (pcap and pcap-ng), and several other
 273          * formats we might support in the future (such as snoop, DOS and
 274          * Windows Sniffer, and Microsoft Network Monitor) all have magic
 275          * numbers that are unique in their first 4 bytes.
 276          */
 277         amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
 278         if (amt_read != sizeof(magic)) {
 279                 if (ferror(fp)) {
 280                         snprintf(errbuf, PCAP_ERRBUF_SIZE,
 281                             "error reading dump file: %s",
 282                             pcap_strerror(errno));
 283                 } else {
 284                         snprintf(errbuf, PCAP_ERRBUF_SIZE,
 285                             "truncated dump file; tried to read %lu file header bytes, only got %lu",
 286                             (unsigned long)sizeof(magic),
 287                             (unsigned long)amt_read);
 288                 }
 289                 return (NULL);
 290         }
 291
 292         /*
 293          * Try all file types.
 294          */
 295         for (i = 0; i < N_FILE_TYPES; i++) {
 296                 p = (*check_headers[i])(magic, fp, precision, errbuf, &err);
 297                 if (p != NULL) {
 298                         /* Yup, that's it. */
 299                         goto found;
 300                 }
 301                 if (err) {
 302                         /*
 303                          * Error trying to read the header.
 304                          */
 305                         return (NULL);
 306                 }
 307         }
 308
 309         /*
 310          * Well, who knows what this mess is....
 311          */
 312         snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
 313         return (NULL);
 314
 315 found:
 316         p->rfile = fp;
 317
 318         /* Padding only needed for live capture fcode */
 319         p->fddipad = 0;
 320
 321 #if !defined(WIN32) && !defined(MSDOS)
 322         /*
 323          * You can do "select()" and "poll()" on plain files on most
 324          * platforms, and should be able to do so on pipes.
 325          *
 326          * You can't do "select()" on anything other than sockets in
 327          * Windows, so, on Win32 systems, we don't have "selectable_fd".
 328          */
 329         p->selectable_fd = fileno(fp);
 330 #endif
 331
 332         p->read_op = pcap_offline_read;
 333         p->inject_op = sf_inject;
 334         p->setfilter_op = install_bpf_program;
 335         p->setdirection_op = sf_setdirection;
 336         p->set_datalink_op = NULL;      /* we don't support munging link-layer headers */
 337         p->getnonblock_op = sf_getnonblock;
 338         p->setnonblock_op = sf_setnonblock;
 339         p->stats_op = sf_stats;
 340 #ifdef WIN32
 341         p->setbuff_op = sf_setbuff;
 342         p->setmode_op = sf_setmode;
 343         p->setmintocopy_op = sf_setmintocopy;
 344 #endif
 345
 346         /*
 347          * For offline captures, the standard one-shot callback can
 348          * be used for pcap_next()/pcap_next_ex().
 349          */
 350         p->oneshot_callback = pcap_oneshot;
 351
 352         /*
 353          * Savefiles never require special BPF code generation.
 354          */
 355         p->bpf_codegen_flags = 0;
 356
 357         p->activated = 1;
 358
 359         return (p);
 360 }
 361
 362 #ifdef WIN32
 363 static
 364 #endif
 365 pcap_t *
 366 pcap_fopen_offline(FILE *fp, char *errbuf)
 367 {
 368         return (pcap_fopen_offline_with_tstamp_precision(fp,
 369             PCAP_TSTAMP_PRECISION_MICRO, errbuf));
 370 }
 371
 372 /*
 373  * Read packets from a capture file, and call the callback for each
 374  * packet.
 375  * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
 376  */
 377 int
 378 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 379 {
 380         struct bpf_insn *fcode;
 381         int status = 0;
 382         int n = 0;
 383         u_char *data;
 384
 385         while (status == 0) {
 386                 struct pcap_pkthdr h;
 387
 388                 /*
 389                  * Has "pcap_breakloop()" been called?
 390                  * If so, return immediately - if we haven't read any
 391                  * packets, clear the flag and return -2 to indicate
 392                  * that we were told to break out of the loop, otherwise
 393                  * leave the flag set, so that the *next* call will break
 394                  * out of the loop without having read any packets, and
 395                  * return the number of packets we've processed so far.
 396                  */
 397                 if (p->break_loop) {
 398                         if (n == 0) {
 399                                 p->break_loop = 0;
 400                                 return (-2);
 401                         } else
 402                                 return (n);
 403                 }
 404
 405                 status = p->next_packet_op(p, &h, &data);
 406                 if (status) {
 407                         if (status == 1)
 408                                 return (0);
 409                         return (status);
 410                 }
 411
 412                 if ((fcode = p->fcode.bf_insns) == NULL ||
 413                     bpf_filter(fcode, data, h.len, h.caplen)) {
 414                         (*callback)(user, &h, data);
 415                         if (++n >= cnt && cnt > 0)
 416                                 break;
 417                 }
 418         }
 419         /*XXX this breaks semantics tcpslice expects */
 420         return (n);
 421 }