56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
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// pcap_loop 循环接收数据
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#include <pcap.h> // libpcap头文件
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#include <stdio.h>
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#include <netinet/in.h>
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#include <netinet/ether.h>
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#include <netinet/ip.h>
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#include <arpa/inet.h> // 网络地址转换函数,如inet_ntoa()->将网络地址转换成“.”点隔的字符串格式
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#include <string.h>
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#include <unistd.h>
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void recv_data_handler(u_char *user_arg, const struct pcap_pkthdr *caphdr, const u_char *data);
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int main(int argc, char const *argv[])
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{
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// 1. 获取可用的网络设备名称
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char *dev = pcap_lookupdev(NULL); // NULL表示获取默认网络设备
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if (dev != NULL)
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{
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printf("网络设备名称: %s\n", dev);
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}
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// 2. 打开网络设备, 开始捕获数据
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char err_buf[PCAP_ERRBUF_SIZE] = "";
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pcap_t *cap = pcap_open_live(dev, 128, 0, 0, err_buf);
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if (cap == NULL)
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{
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printf("open pcap fail: %s\n", err_buf);
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return -1;
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}
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// 编译过滤规则, 成功则设置过滤规则
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char filter[] = "udp dst port 8001";
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struct bpf_program program; // 过滤器程序结构体，采用bpf（伯克利包过滤器）
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if (pcap_compile(cap, &program, filter, 0, 0xffffff00) == 0)
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{
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pcap_setfilter(cap, &program);
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}
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// 循环捕获数据
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pcap_loop(cap, -1, recv_data_handler, NULL);
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// 关闭网卡设备
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pcap_close(cap);
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return 0;
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}
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void recv_data_handler(u_char *user_arg, const struct pcap_pkthdr *cap_hdr, const u_char *data)
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{
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if (cap_hdr->caplen > 0)
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{
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printf("数据包长度: %d, 实际长度: %d\n", cap_hdr->caplen, cap_hdr->len);
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}
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sleep(1);
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}
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