linux中jpcap的使用

#include <stdio.h>
#include <jpcap.h>

void packet_handler(u_char *user, const struct pcap_pkthdr *pkthdr, const u_char *packet) {
    printf("Packet length: %d
", pkthdr->len);
}

int main() {
    char errbuf[PCAP_ERRBUF_SIZE];
    pcap_if_t *alldevs;
    pcap_if_t *d;
    int inum;
    pcap_t *adhandle;

    // 获取网络设备列表
    if (pcap_findalldevs(&alldevs, errbuf) == -1) {
        fprintf(stderr, "Error in pcap_findalldevs: %s
", errbuf);
        return 1;
    }

    // 打印设备列表并选择
    int i = 0;
    for (d = alldevs; d; d = d->next) {
        printf("%d. %s", ++i, d->name);
        if (d->description)
            printf(" (%s)
", d->description);
        else
            printf(" (No description available)
");
    }

    if (i == 0) {
        printf("No interfaces found! Make sure WinPcap is installed.
");
        return 1;
    }

    printf("Enter the interface number (1-%d):", i);
    scanf("%d", &inum);

    if (inum < 1 || inum > i) {
        printf("Interface number out of range.
");
        pcap_freealldevs(alldevs);
        return 1;
    }

    // 跳转到选定的设备
    for (d = alldevs, i = 0; i < inum - 1; d = d->next, i++);

    // 打开设备
    if ((adhandle = pcap_open_live(d->name, 65536, 1, 1000, errbuf)) == NULL) {
        fprintf(stderr, "Couldn't open device %s: %s
", d->name, errbuf);
        pcap_freealldevs(alldevs);
        return 1;
    }

    // 开始抓包
    pcap_loop(adhandle, 0, packet_handler, NULL);

    pcap_close(adhandle);
    pcap_freealldevs(alldevs);
    return 0;
}