winpcap/Examples-pcap/basic_dump/basic_dump.c

   1 #include "pcap.h"
   2
   3 /* prototype of the packet handler */
   4 void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data);
   5
   6 main()
   7 {
   8         pcap_if_t *alldevs;
   9         pcap_if_t *d;
  10         int inum;
  11         int i=0;
  12         pcap_t *adhandle;
  13         char errbuf[PCAP_ERRBUF_SIZE];
  14
  15         /* Retrieve the device list */
  16         if(pcap_findalldevs(&alldevs, errbuf) == -1)
  17         {
  18                 fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
  19                 exit(1);
  20         }
  21
  22         /* Print the list */
  23         for(d=alldevs; d; d=d->next)
  24         {
  25                 printf("%d. %s", ++i, d->name);
  26                 if (d->description)
  27                         printf(" (%s)\n", d->description);
  28                 else
  29                         printf(" (No description available)\n");
  30         }
  31
  32         if(i==0)
  33         {
  34                 printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
  35                 return -1;
  36         }
  37
  38         printf("Enter the interface number (1-%d):",i);
  39         scanf("%d", &inum);
  40
  41         if(inum < 1 || inum > i)
  42         {
  43                 printf("\nInterface number out of range.\n");
  44                 /* Free the device list */
  45                 pcap_freealldevs(alldevs);
  46                 return -1;
  47         }
  48
  49         /* Jump to the selected adapter */
  50         for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);
  51
  52         /* Open the device */
  53         /* Open the adapter */
  54         if ((adhandle= pcap_open_live(d->name,  // name of the device
  55                                                          65536,                 // portion of the packet to capture.
  56                                                                                         // 65536 grants that the whole packet will be captured on all the MACs.
  57                                                          1,                             // promiscuous mode (nonzero means promiscuous)
  58                                                          1000,                  // read timeout
  59                                                          errbuf                 // error buffer
  60                                                          )) == NULL)
  61         {
  62                 fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
  63                 /* Free the device list */
  64                 pcap_freealldevs(alldevs);
  65                 return -1;
  66         }
  67
  68         printf("\nlistening on %s...\n", d->description);
  69
  70         /* At this point, we don't need any more the device list. Free it */
  71         pcap_freealldevs(alldevs);
  72
  73         /* start the capture */
  74         pcap_loop(adhandle, 0, packet_handler, NULL);
  75
  76         pcap_close(adhandle);
  77         return 0;
  78 }
  79
  80
  81 /* Callback function invoked by libpcap for every incoming packet */
  82 void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data)
  83 {
  84         struct tm *ltime;
  85         char timestr[16];
  86         time_t local_tv_sec;
  87
  88         /* convert the timestamp to readable format */
  89         local_tv_sec = header->ts.tv_sec;
  90         ltime=localtime(&local_tv_sec);
  91         strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);
  92
  93         printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len);
  94
  95 }