应用层通过socket接口的XFRM_MSG_NEWSA类型新增一个SA的C代码

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/socket.h> #include <linux/xfrm.h>

int main(int argc, char** argv) {

int sock_fd, err;
struct sockaddr_nl nl_addr;
struct {
    struct nlmsghdr nlh;
    struct xfrm_userpolicy_info info;
    char buf[256];
} req;

// 创建Netlink socket
sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_XFRM);
if (sock_fd < 0) {
    perror("socket");
    exit(EXIT_FAILURE);
}

// 绑定Netlink socket
memset(&nl_addr, 0, sizeof(nl_addr));
nl_addr.nl_family = AF_NETLINK;
err = bind(sock_fd, (struct sockaddr*)&nl_addr, sizeof(nl_addr));
if (err < 0) {
    perror("bind");
    close(sock_fd);
    exit(EXIT_FAILURE);
}

// 准备发送消息
memset(&req, 0, sizeof(req));
req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_info));
req.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
req.nlh.nlmsg_type = XFRM_MSG_NEWSA;
req.info.sel.family = AF_UNSPEC;

// 发送消息
err = send(sock_fd, &req, req.nlh.nlmsg_len, 0);
if (err < 0) {
    perror("send");
    close(sock_fd);
    exit(EXIT_FAILURE);
}

// 接收回复消息
err = recv(sock_fd, &req, sizeof(req), 0);
if (err < 0) {
    perror("recv");
    close(sock_fd);
    exit(EXIT_FAILURE);
}

// 检查回复消息类型
if (req.nlh.nlmsg_type != NLMSG_ERROR) {
    printf("SA created successfully\n");
} else {
    perror("SA creation failed");
    close(sock_fd);
    exit(EXIT_FAILURE);
}

close(sock_fd);
return 0;