libpcap : No Wireless Devices detected
I want to capture packets going out of my machine, and I'm using libpcap (version 1.0.0-1)开发者_运维知识库 for the same. The problem is, that a basic program like this -
#include <stdio.h>
#include <pcap.h>
int main(int argc, char *argv[]) {
char *dev, errbuf[PCAP_ERRBUF_SIZE];
dev = pcap_lookupdev(errbuf);
if (dev == NULL) {
fprintf(stderr, "%s\n", errbuf);
return (2);
}
printf("Device : %s\n", dev);
return (0);
}
does not seem to display the wireless interface. Everytime I compile and run the program, it detects eth0. How can I make it capture the wireless interfaces as well?
pcap_lookupdev() returns the default networking device on the system, which is usually the first device listed. pcap_findalldevs() returns an enumeration of all devices in the system, which you can use to select a device and capture from it.
try using pcap_findalldevs(). i guess pcap_lookupdev() matches the first entry in the list is suitable interfaces
As others have stated, pcap_lookupdev()
simply returns the first device found. You need to use pcap_findalldevs()
to build a list of all available devices, then prompt the user to pick one (or let the user specify a number n on the command line, and then use the _n_th device).
But, if this is just a quick-and-dirty test program, you can find out the interface name and code it directly into your program. You can use ifconfig
or tcpdump -D
to find out the interface names on your system, then make a call like pcap_create("en1", errbuf)
.
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