wlantest/readpcap.c

   1 /*
   2  * PCAP capture file reader
   3  * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "utils/includes.h"
  16 #include <pcap/pcap.h>
  17
  18 #include "utils/common.h"
  19 #include "wlantest.h"
  20
  21
  22 int read_cap_file(struct wlantest *wt, const char *fname)
  23 {
  24         char errbuf[PCAP_ERRBUF_SIZE];
  25         pcap_t *pcap;
  26         unsigned int count = 0;
  27         struct pcap_pkthdr *hdr;
  28         const u_char *data;
  29         int res;
  30
  31         pcap = pcap_open_offline(fname, errbuf);
  32         if (pcap == NULL) {
  33                 wpa_printf(MSG_ERROR, "Failed to read pcap file '%s': %s",
  34                            fname, errbuf);
  35                 return -1;
  36         }
  37
  38         for (;;) {
  39                 res = pcap_next_ex(pcap, &hdr, &data);
  40                 if (res == -2)
  41                         break; /* No more packets */
  42                 if (res == -1) {
  43                         wpa_printf(MSG_INFO, "pcap_next_ex failure: %s",
  44                                    pcap_geterr(pcap));
  45                         break;
  46                 }
  47                 if (res != 1) {
  48                         wpa_printf(MSG_INFO, "Unexpected pcap_next_ex return "
  49                                    "value %d", res);
  50                         break;
  51                 }
  52
  53                 /* Packet was read without problems */
  54                 wpa_printf(MSG_EXCESSIVE, "pcap hdr: ts=%d.%06d "
  55                            "len=%u/%u",
  56                            (int) hdr->ts.tv_sec, (int) hdr->ts.tv_usec,
  57                            hdr->caplen, hdr->len);
  58                 if (hdr->caplen < hdr->len) {
  59                         wpa_printf(MSG_DEBUG, "pcap: Dropped incomplete frame "
  60                                    "(%u/%u captured)",
  61                                    hdr->caplen, hdr->len);
  62                         continue;
  63                 }
  64                 count++;
  65                 wlantest_process(wt, data, hdr->caplen);
  66         }
  67
  68         pcap_close(pcap);
  69
  70         wpa_printf(MSG_DEBUG, "Read %s: %u packets", fname, count);
  71
  72         return 0;
  73 }