winpcap/Examples-pcap/basic_dump_ex/basic_dump_ex.c

   1 #include "pcap.h"
   2
   3
   4 int main()
   5 {
   6         pcap_if_t *alldevs;
   7         pcap_if_t *d;
   8         int inum;
   9         int i=0;
  10         pcap_t *adhandle;
  11         int res;
  12         char errbuf[PCAP_ERRBUF_SIZE];
  13         struct tm *ltime;
  14         char timestr[16];
  15         struct pcap_pkthdr *header;
  16         const u_char *pkt_data;
  17         time_t local_tv_sec;
  18
  19
  20         /* Retrieve the device list */
  21         if(pcap_findalldevs(&alldevs, errbuf) == -1)
  22         {
  23                 fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
  24                 return -1;
  25         }
  26
  27     /* Print the list */
  28     for(d=alldevs; d; d=d->next)
  29     {
  30         printf("%d. %s", ++i, d->name);
  31         if (d->description)
  32             printf(" (%s)\n", d->description);
  33         else
  34             printf(" (No description available)\n");
  35     }
  36
  37     if(i==0)
  38     {
  39         printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
  40         return -1;
  41     }
  42
  43     printf("Enter the interface number (1-%d):",i);
  44     scanf("%d", &inum);
  45
  46     if(inum < 1 || inum > i)
  47     {
  48         printf("\nInterface number out of range.\n");
  49         /* Free the device list */
  50         pcap_freealldevs(alldevs);
  51         return -1;
  52     }
  53
  54     /* Jump to the selected adapter */
  55     for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);
  56
  57         /* Open the adapter */
  58         if ((adhandle= pcap_open_live(d->name,  // name of the device
  59                                                          65536,                 // portion of the packet to capture.
  60                                                                                         // 65536 grants that the whole packet will be captured on all the MACs.
  61                                                          1,                             // promiscuous mode (nonzero means promiscuous)
  62                                                          1000,                  // read timeout
  63                                                          errbuf                 // error buffer
  64                                                          )) == NULL)
  65         {
  66                 fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
  67                 /* Free the device list */
  68                 pcap_freealldevs(alldevs);
  69                 return -1;
  70         }
  71
  72     printf("\nlistening on %s...\n", d->description);
  73
  74     /* At this point, we don't need any more the device list. Free it */
  75     pcap_freealldevs(alldevs);
  76
  77         /* Retrieve the packets */
  78         while((res = pcap_next_ex( adhandle, &header, &pkt_data)) >= 0){
  79
  80                 if(res == 0)
  81                         /* Timeout elapsed */
  82                         continue;
  83
  84                 /* convert the timestamp to readable format */
  85                 local_tv_sec = header->ts.tv_sec;
  86                 ltime=localtime(&local_tv_sec);
  87                 strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);
  88
  89                 printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len);
  90         }
  91
  92         if(res == -1){
  93                 printf("Error reading the packets: %s\n", pcap_geterr(adhandle));
  94                 return -1;
  95         }
  96
  97    pcap_close(adhandle);
  98    return 0;
  99 }