c语言 获取linuxipv6路由表

可以使用Socket编程来获取Linux的IPv6路由表。下面是一个使用C语言编写的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/route.h>

#define BUF_SIZE 4096

int main() {
    int sock;
    struct rtmsg *route_entry;
    struct nlmsghdr *nl_header;
    struct rtattr *rt_attribute;
    char buffer[BUF_SIZE];

    // 创建socket
    sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
    if (sock < 0) {
        perror("socket");
        exit(1);
    }

    // 初始化请求消息
    memset(buffer, 0, BUF_SIZE);
    nl_header = (struct nlmsghdr *)buffer;
    nl_header->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
    nl_header->nlmsg_type = RTM_GETROUTE;
    nl_header->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
    nl_header->nlmsg_seq = 1;
    nl_header->nlmsg_pid = getpid();

    // 设置请求消息的路由属性
    rt_attribute = (struct rtattr *)NLMSG_DATA(nl_header);
    rt_attribute->rta_type = RTA_DST;
    rt_attribute->rta_len = RTA_LENGTH(sizeof(struct in6_addr));
    inet_pton(AF_INET6, "2001:db8::/32", RTA_DATA(rt_attribute));

    // 发送请求消息
    if (send(sock, nl_header, nl_header->nlmsg_len, 0) < 0) {
        perror("send");
        exit(1);
    }

    // 接收并处理回复消息
    while (1) {
        int len = recv(sock, buffer, BUF_SIZE, 0);
        if (len < 0) {
            perror("recv");
            exit(1);
        }

        for (nl_header = (struct nlmsghdr *)buffer; NLMSG_OK(nl_header, len); nl_header = NLMSG_NEXT(nl_header, len)) {
            if (nl_header->nlmsg_type == NLMSG_DONE) {
                break;
            }

            route_entry = (struct rtmsg *)NLMSG_DATA(nl_header);
            rt_attribute = (struct rtattr *)RTM_RTA(route_entry);
            int rt_attr_len = RTM_PAYLOAD(nl_header);

            for (; RTA_OK(rt_attribute, rt_attr_len); rt_attribute = RTA_NEXT(rt_attribute, rt_attr_len)) {
                if (rt_attribute->rta_type == RTA_DST) {
                    struct in6_addr *addr = (struct in6_addr *)RTA_DATA(rt_attribute);
                    char ip_str[INET6_ADDRSTRLEN];
                    inet_ntop(AF_INET6, addr, ip_str, sizeof(ip_str));
                    printf("Route: %s\n", ip_str);
                }
            }
        }
    }

    // 关闭socket
    close(sock);

    return 0;
}

注意：需要在代码中修改`inet_pton(AF_INET6, "2001:db8::/32", RTA_DATA(rt_attribute))`这一行，将`"2001:db8::/32"`改为你想要查询的IPv6网段。

这段代码使用Netlink套接字接口向内核发送RTM_GETROUTE消息，并解析内核的回复，将获取到的IPv6路由表打印出来。请确保以root权限运行代码，因为获取路由表需要特权访问。

希望对你有帮助！如果有任何疑问，请随时提问。