Thread: libpcap : SIOCGIFHWADDR: No such device

Hello. I've just started using libpcap lib and been following some tutorials.

Code:

#include <pcap.h>
#include <stdlib.h>
#include <stdio.h>

void dump(const unsigned char *data_buffer, const unsigned int length);
void pcap_fatal(const char *failed_in, const char *errbuf);

int main() {
   struct pcap_pkthdr header;
   const u_char *packet;
   char errbuf[PCAP_ERRBUF_SIZE];
   char *device;
   pcap_t *pcap_handle;
   int i;

pcap_handle = pcap_open_live(device, 4096, 1, 0, errbuf);
if(pcap_handle == NULL)
   pcap_fatal("pcap_open_live", errbuf);

for(i=0; i < 3; i++) {
      packet = pcap_next(pcap_handle, &header);
      printf("Got a %d byte packet\n", header.len);
      dump(packet, header.len);
   }
   pcap_close(pcap_handle);
}

Code:

xyz@ubuntu:~/Desktop/Programs$ gcc -o sniff libpcap.c -l pcap
xyz@ubuntu:~/Desktop/Programs$ ./sniff
Fatal Error in pcap_open_live: socket: Operation not permitted
xyz@ubuntu:~/Desktop/Programs$ sudo ./sniff
Fatal Error in pcap_open_live: SIOCGIFHWADDR: No such device

Apparently pcap_live_open() keeps returning NULL, therefore the error I don't quite understand. I went over dozens of topics searching for solution, but couldn't quite find it.

As far as I get it, SIOCGIFHWADDR is an interface hardware address but I'm not sure what it's all about.

Thanks in advance,

Mercurial

Right. Thanks for that.

Code:

#define DEVICE_SIZE 1000
// ...

device = (char*) malloc(DEVICE_SIZE*sizeof(char));

pcap_handle = pcap_open_live(device, 4096, 1, 0, errbuf);
if(pcap_handle == NULL)
   pcap_fatal("pcap_open_live", errbuf);

Same error though.

If I actually understood the device part, I wouldn't be posting this topic.

Thanks alot.