/*

 * Copyright (c) 1993, 1994, 1995, 1996, 1997

 *  The Regents of the University of California.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that: (1) source code distributions

 * retain the above copyright notice and this paragraph in its entirety, (2)

 * distributions including binary code include the above copyright notice and

 * this paragraph in its entirety in the documentation or other materials

 * provided with the distribution, and (3) all advertising materials mentioning

 * features or use of this software display the following acknowledgement:

 * ``This product includes software developed by the University of California,

 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of

 * the University nor the names of its contributors may be used to endorse

 * or promote products derived from this software without specific prior

 * written permission.

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED

 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 *

 * savefile.c - supports offline use of tcpdump

 *  Extraction/creation by Jeffrey Mogul, DECWRL

 *  Modified by Steve McCanne, LBL.

 *

 * Used to save the received packet headers, after filtering, to

 * a file, and then read them later.

 * The first record in the file contains saved values for the machine

 * dependent values so we can print the dump file on any architecture.

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <pcap-types.h>

#ifdef _WIN32

#include <io.h>

#include <fcntl.h>

#endif /* _WIN32 */

#include <errno.h>

#include <memory.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <limits.h> /* for INT_MAX */

#include "pcap-int.h"

#ifdef HAVE_OS_PROTO_H

#include "os-proto.h"

#endif

#include "sf-pcap.h"

#include "sf-pcapng.h"

#include "pcap-common.h"

#ifdef _WIN32

/*

 * These aren't exported on Windows, because they would only work if both

 * WinPcap/Npcap and the code using it were to use the Universal CRT; otherwise,

 * a FILE structure in WinPcap/Npcap and a FILE structure in the code using it

 * could be different if they're using different versions of the C runtime.

 *

 * Instead, pcap/pcap.h defines them as macros that wrap the hopen versions,

 * with the wrappers calling _fileno() and _get_osfhandle() themselves,

 * so that they convert the appropriate CRT version's FILE structure to

 * a HANDLE (which is OS-defined, not CRT-defined, and is part of the Win32

 * and Win64 ABIs).

 */

static pcap_t *pcap_fopen_offline_with_tstamp_precision(FILE *, u_int, char *);

static pcap_t *pcap_fopen_offline(FILE *, char *);

#endif

/*

 * Setting O_BINARY on DOS/Windows is a bit tricky

 */

#if defined(_WIN32)

  #define SET_BINMODE(f)  _setmode(_fileno(f), _O_BINARY)

#elif defined(MSDOS)

  #if defined(__HIGHC__)

  #define SET_BINMODE(f)  setmode(f, O_BINARY)

  #else

  #define SET_BINMODE(f)  setmode(fileno(f), O_BINARY)

  #endif

#endif

static int

sf_getnonblock(pcap_t *p _U_)

{

  /*

   * This is a savefile, not a live capture file, so never say

   * it's in non-blocking mode.

   */

  return (0);

}

static int

sf_setnonblock(pcap_t *p, int nonblock _U_)

{

  /*

   * This is a savefile, not a live capture file, so reject

   * requests to put it in non-blocking mode.  (If it's a

   * pipe, it could be put in non-blocking mode, but that

   * would significantly complicate the code to read packets,

   * as it would have to handle reading partial packets and

   * keeping the state of the read.)

   */

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "Savefiles cannot be put into non-blocking mode");

  return (-1);

}

static int

sf_stats(pcap_t *p, struct pcap_stat *ps _U_)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "Statistics aren't available from savefiles");

  return (-1);

}

#ifdef _WIN32

static struct pcap_stat *

sf_stats_ex(pcap_t *p, int *size)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "Statistics aren't available from savefiles");

  return (NULL);

}

static int

sf_setbuff(pcap_t *p, int dim)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "The kernel buffer size cannot be set while reading from a file");

  return (-1);

}

static int

sf_setmode(pcap_t *p, int mode)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "impossible to set mode while reading from a file");

  return (-1);

}

static int

sf_setmintocopy(pcap_t *p, int size)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "The mintocopy parameter cannot be set while reading from a file");

  return (-1);

}

static HANDLE

sf_getevent(pcap_t *pcap)

{

  (void)pcap_snprintf(pcap->errbuf, sizeof(pcap->errbuf),

      "The read event cannot be retrieved while reading from a file");

  return (INVALID_HANDLE_VALUE);

}

static int

sf_oid_get_request(pcap_t *p, bpf_u_int32 oid _U_, void *data _U_,

    size_t *lenp _U_)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "An OID get request cannot be performed on a file");

  return (PCAP_ERROR);

}

static int

sf_oid_set_request(pcap_t *p, bpf_u_int32 oid _U_, const void *data _U_,

    size_t *lenp _U_)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "An OID set request cannot be performed on a file");

  return (PCAP_ERROR);

}

static u_int

sf_sendqueue_transmit(pcap_t *p, pcap_send_queue *queue, int sync)

{

  pcap_strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",

      PCAP_ERRBUF_SIZE);

  return (0);

}

static int

sf_setuserbuffer(pcap_t *p, int size)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "The user buffer cannot be set when reading from a file");

  return (-1);

}

static int

sf_live_dump(pcap_t *p, char *filename, int maxsize, int maxpacks)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "Live packet dumping cannot be performed when reading from a file");

  return (-1);

}

static int

sf_live_dump_ended(pcap_t *p, int sync)

{

  pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

      "Live packet dumping cannot be performed on a pcap_open_dead pcap_t");

  return (-1);

}

static PAirpcapHandle

sf_get_airpcap_handle(pcap_t *pcap)

{

  return (NULL);

}

#endif

static int

sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)

{

  pcap_strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",

      PCAP_ERRBUF_SIZE);

  return (-1);

}

/*

 * Set direction flag: Which packets do we accept on a forwarding

 * single device? IN, OUT or both?

 */

static int

sf_setdirection(pcap_t *p, pcap_direction_t d _U_)

{

  pcap_snprintf(p->errbuf, sizeof(p->errbuf),

      "Setting direction is not supported on savefiles");

  return (-1);

}

void

sf_cleanup(pcap_t *p)

{

  if (p->rfile != stdin)

    (void)fclose(p->rfile);

  if (p->buffer != NULL)

    free(p->buffer);

  pcap_freecode(&p->fcode);

}

pcap_t *

pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,

          char *errbuf)

{

  FILE *fp;

  pcap_t *p;

  if (fname == NULL) {

    pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,

        "A null pointer was supplied as the file name");

    return (NULL);

  }

  if (fname[0] == '-' && fname[1] == '\0')

  {

    fp = stdin;

#if defined(_WIN32) || defined(MSDOS)

    /*

     * We're reading from the standard input, so put it in binary

     * mode, as savefiles are binary files.

     */

    SET_BINMODE(fp);

#endif

  }

  else {

    /*

     * "b" is supported as of C90, so *all* UN*Xes should

     * support it, even though it does nothing.  It's

     * required on Windows, as the file is a binary file

     * and must be read in binary mode.

     */

    fp = fopen(fname, "rb");

    if (fp == NULL) {

      pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,

          errno, "%s", fname);

      return (NULL);

    }

  }

  p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);

  if (p == NULL) {

    if (fp != stdin)

      fclose(fp);

  }

  return (p);

}

pcap_t *

pcap_open_offline(const char *fname, char *errbuf)

{

  return (pcap_open_offline_with_tstamp_precision(fname,

      PCAP_TSTAMP_PRECISION_MICRO, errbuf));

}

#ifdef _WIN32

pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,

    char *errbuf)

{

  int fd;

  FILE *file;

  fd = _open_osfhandle(osfd, _O_RDONLY);

  if ( fd < 0 )

  {

    pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,

        errno, "_open_osfhandle");

    return NULL;

  }

  file = _fdopen(fd, "rb");

  if ( file == NULL )

  {

    pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,

        errno, "_fdopen");

    _close(fd);

    return NULL;

  }

  return pcap_fopen_offline_with_tstamp_precision(file, precision,

      errbuf);

}

pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)

{

  return pcap_hopen_offline_with_tstamp_precision(osfd,

      PCAP_TSTAMP_PRECISION_MICRO, errbuf);

}

#endif

/*

 * Given a link-layer header type and snapshot length, return a

 * snapshot length to use when reading the file; it's guaranteed

 * to be > 0 and <= INT_MAX.

 *

 * XXX - the only reason why we limit it to <= INT_MAX is so that

 * it fits in p->snapshot, and the only reason that p->snapshot is

 * signed is that pcap_snapshot() returns an int, not an unsigned int.

 */

bpf_u_int32

pcap_adjust_snapshot(bpf_u_int32 linktype, bpf_u_int32 snaplen)

{

  if (snaplen == 0 || snaplen > INT_MAX) {

    /*

     * Bogus snapshot length; use the maximum for this

     * link-layer type as a fallback.

     *

     * XXX - we don't clamp snapshot lengths that are

     * <= INT_MAX but > max_snaplen_for_dlt(linktype),

     * so a capture file could cause us to allocate

     * a Really Big Buffer.

     */

    snaplen = max_snaplen_for_dlt(linktype);

  }

  return snaplen;

}

static pcap_t *(*check_headers[])(const uint8_t *, FILE *, u_int, char *, int *) = {

  pcap_check_header,

  pcap_ng_check_header

};

#define N_FILE_TYPES  (sizeof check_headers / sizeof check_headers[0])

#ifdef _WIN32

static

#endif

pcap_t *

pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,

    char *errbuf)

{

  register pcap_t *p;

  uint8_t magic[4];

  size_t amt_read;

  u_int i;

  int err;

  /*

   * Read the first 4 bytes of the file; the network analyzer dump

   * file formats we support (pcap and pcapng), and several other

   * formats we might support in the future (such as snoop, DOS and

   * Windows Sniffer, and Microsoft Network Monitor) all have magic

   * numbers that are unique in their first 4 bytes.

   */

  amt_read = fread(&magic, 1, sizeof(magic), fp);

  if (amt_read != sizeof(magic)) {

    if (ferror(fp)) {

      pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,

          errno, "error reading dump file");

    } else {

      pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,

          "truncated dump file; tried to read %" PRIsize " file header bytes, only got %" PRIsize,

          sizeof(magic), amt_read);

    }

    return (NULL);

  }

  /*

   * Try all file types.

   */

  for (i = 0; i < N_FILE_TYPES; i++) {

    p = (*check_headers[i])(magic, fp, precision, errbuf, &err);

    if (p != NULL) {

      /* Yup, that's it. */

      goto found;

    }

    if (err) {

      /*

       * Error trying to read the header.

       */

      return (NULL);

    }

  }

  /*

   * Well, who knows what this mess is....

   */

  pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");

  return (NULL);

found:

  p->rfile = fp;

  /* Padding only needed for live capture fcode */

  p->fddipad = 0;

#if !defined(_WIN32) && !defined(MSDOS)

  /*

   * You can do "select()" and "poll()" on plain files on most

   * platforms, and should be able to do so on pipes.

   *

   * You can't do "select()" on anything other than sockets in

   * Windows, so, on Win32 systems, we don't have "selectable_fd".

   */

  p->selectable_fd = fileno(fp);

#endif

  p->read_op = pcap_offline_read;

  p->inject_op = sf_inject;

  p->setfilter_op = install_bpf_program;

  p->setdirection_op = sf_setdirection;

  p->set_datalink_op = NULL;  /* we don't support munging link-layer headers */

  p->getnonblock_op = sf_getnonblock;

  p->setnonblock_op = sf_setnonblock;

  p->stats_op = sf_stats;

#ifdef _WIN32

  p->stats_ex_op = sf_stats_ex;

  p->setbuff_op = sf_setbuff;

  p->setmode_op = sf_setmode;

  p->setmintocopy_op = sf_setmintocopy;

  p->getevent_op = sf_getevent;

  p->oid_get_request_op = sf_oid_get_request;

  p->oid_set_request_op = sf_oid_set_request;

  p->sendqueue_transmit_op = sf_sendqueue_transmit;

  p->setuserbuffer_op = sf_setuserbuffer;

  p->live_dump_op = sf_live_dump;

  p->live_dump_ended_op = sf_live_dump_ended;

  p->get_airpcap_handle_op = sf_get_airpcap_handle;

#endif

  /*

   * For offline captures, the standard one-shot callback can

   * be used for pcap_next()/pcap_next_ex().

   */

  p->oneshot_callback = pcap_oneshot;

  /*

   * Savefiles never require special BPF code generation.

   */

  p->bpf_codegen_flags = 0;

  p->activated = 1;

  return (p);

}

#ifdef _WIN32

static

#endif

pcap_t *

pcap_fopen_offline(FILE *fp, char *errbuf)

{

  return (pcap_fopen_offline_with_tstamp_precision(fp,

      PCAP_TSTAMP_PRECISION_MICRO, errbuf));

}

/*

 * Read packets from a capture file, and call the callback for each

 * packet.

 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.

 */

int

pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)

{

  struct bpf_insn *fcode;

  int status = 0;

  int n = 0;

  u_char *data;

  while (status == 0) {

    struct pcap_pkthdr h;

    /*

     * Has "pcap_breakloop()" been called?

     * If so, return immediately - if we haven't read any

     * packets, clear the flag and return -2 to indicate

     * that we were told to break out of the loop, otherwise

     * leave the flag set, so that the *next* call will break

     * out of the loop without having read any packets, and

     * return the number of packets we've processed so far.

     */

    if (p->break_loop) {

      if (n == 0) {

        p->break_loop = 0;

        return (-2);

      } else

        return (n);

    }

    status = p->next_packet_op(p, &h, &data);

    if (status) {

      if (status == 1)

        return (0);

      return (status);

    }

    if ((fcode = p->fcode.bf_insns) == NULL ||

        bpf_filter(fcode, data, h.len, h.caplen)) {

      (*callback)(user, &h, data);

      if (++n >= cnt && cnt > 0)

        break;

    }

  }

  /*XXX this breaks semantics tcpslice expects */

  return (n);

}