winpcap/Examples/misc/basic_dump_ex.c

   1 #include "pcap.h"
   2
   3
   4 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 on the local machine */
  21         if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1)
  22         {
  23                 fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
  24                 exit(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 device */
  58         if ( (adhandle= pcap_open(d->name,                      // name of the device
  59                                                           65536,                        // portion of the packet to capture.
  60                                                                                                 // 65536 guarantees that the whole packet will be captured on all the link layers
  61                                                           PCAP_OPENFLAG_PROMISCUOUS,    // promiscuous mode
  62                                                           1000,                         // read timeout
  63                                                           NULL,                         // authentication on the remote machine
  64                                                           errbuf                        // error buffer
  65                                                           ) ) == NULL)
  66         {
  67                 fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
  68                 /* Free the device list */
  69                 pcap_freealldevs(alldevs);
  70                 return -1;
  71         }
  72
  73     printf("\nlistening on %s...\n", d->description);
  74
  75     /* At this point, we don't need any more the device list. Free it */
  76     pcap_freealldevs(alldevs);
  77
  78         /* Retrieve the packets */
  79         while((res = pcap_next_ex( adhandle, &header, &pkt_data)) >= 0){
  80
  81                 if(res == 0)
  82                         /* Timeout elapsed */
  83                         continue;
  84
  85                 /* convert the timestamp to readable format */
  86                 local_tv_sec = header->ts.tv_sec;
  87                 ltime=localtime(&local_tv_sec);
  88                 strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);
  89
  90                 printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len);
  91         }
  92
  93         if(res == -1){
  94                 printf("Error reading the packets: %s\n", pcap_geterr(adhandle));
  95                 return -1;
  96         }
  97
  98     return 0;
  99 }