linux netlink使用

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>

#define BUFLEN 8192

void die(char *s) {
    perror(s);
    exit(1);
}

int main() {
    int sockfd;
    struct sockaddr_nl sa;
    struct nlmsghdr *nlh = NULL;
    struct iovec iov;
    int len;
    char buf[BUFLEN];

    sockfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
    if (sockfd < 0) {
        die("socket");
    }

    memset(&sa, 0, sizeof(sa));
    sa.nl_family = AF_NETLINK;
    sa.nl_groups = RTMGRP_IPV4_ROUTE;

    if (bind(sockfd, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
        die("bind");
    }

    iov.iov_base = (void *)buf;
    iov.iov_len = BUFLEN;
    len = recvmsg(sockfd, &iov, 0);
    if (len < 0) {
        die("recvmsg");
    }

    nlh = (struct nlmsghdr *)buf;
    for (; NLMSG_OK(nlh, len); nlh = NLMSG_NEXT(nlh, len)) {
        if (nlh->nlmsg_type == NLMSG_DONE) {
            break;
        }
        if (nlh->nlmsg_type == RTM_NEWROUTE) {
            // Process the route message here
            printf("Route message received\n");
        }
    }

    close(sockfd);
    return 0;
}