libpcap 编程一（安装与获取网络接口信息）

安装

（本机环境：ubuntu 9.04）

在使用libpcap前，先安装libpcap

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

2）安装libpcap的依赖包：

     $ sudo apt-get install flex

     $ sudo apt-get install bison

3）安装libpcap

     $ unzip <libpcap-version>

     $ ./configure

     $ make

     $ sudo make install

 

编程

使用libpcap获取可用的网络接口、IP地址和掩码

#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_SIZE1024int 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;}