libpcap 編程一（安裝與獲取網絡接口信息）

安裝

（本機環境：ubuntu 9.04）

在使用libpcap前，先安裝libpcap

1）下載libpcap：http://www.tcpdump.org/release/

2）安裝libpcap的依賴包：

     $ sudo apt-get install flex

     $ sudo apt-get install bison

3）安裝libpcap

     $ unzip <libpcap-version>

     $ ./configure

     $ make

     $ sudo make install

 

編程

使用libpcap獲取可用的網絡接口、IP地址和掩碼

#include <stdio.h> #include <stdlib.h> #include <pcap.h> #include <errno.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #define PCAP_ERRBUF_SIZE 1024 int main(int argc, char *argv[]) { char *dev; char *net; char *mask; int ret; char errbuf[PCAP_ERRBUF_SIZE]; bpf_u_int32 netip; bpf_u_int32 netmask; struct in_addr addr; /* find a valid device for use to sniff on */ dev = pcap_lookupdev(errbuf); /* error checking */ if(dev == NULL) { printf("%s/n", errbuf); exit(1); } printf("DEV: %s/n", dev); /* ask pcap fro the network address and mask of the device */ ret = pcap_lookupnet(dev, &netip, &netmask, errbuf); if(ret == -1) { printf(" %s/n", errbuf); exit(1); } /* get the ip address */ addr.s_addr = netip; net = inet_ntoa(addr); if(net == NULL) { perror("inet_ntoa"); exit(1); } printf("NET: %s/n", net); /* get the netmask */ addr.s_addr = netmask; mask = inet_ntoa(addr); if(mask == NULL) { perror("inet_ntoa"); exit(1); } printf("MASK: %s/n", mask); return 0; }