如何使用pcap.h c++进行ip过滤

#include <pcap.h>

pcap_t* handle;
char errbuf[PCAP_ERRBUF_SIZE];

handle = pcap_open_live("eth0", BUFSIZ, 1, 1000, errbuf);
// 或者
handle = pcap_open_offline("capture.pcap", errbuf);

struct bpf_program fp;
char filter_exp[] = "ip src 192.168.0.1"; // 这里是过滤规则，可以根据需求修改

if (pcap_compile(handle, &fp, filter_exp, 0, PCAP_NETMASK_UNKNOWN) == -1) {
    printf("过滤规则编译失败\n");
    return -1;
}

if (pcap_setfilter(handle, &fp) == -1) {
    printf("过滤规则设置失败\n");
    return -1;
}

void packet_handler(u_char* user_data, const struct pcap_pkthdr* pkthdr, const u_char* packet) {
    // 处理数据包的逻辑
}

pcap_loop(handle, 0, packet_handler, NULL);

pcap_close(handle);