使用setsockopt()将dscp值设置为socket

#include <iostream>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

int main() {
    int sockfd;
    struct sockaddr_in server_addr;
    int dscp_value = 46; // DSCP value: EF (Expedited Forwarding)

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        std::cerr << "Error creating socket" << std::endl;
        return 1;
    }

    // Set DSCP value
    int option_value = (dscp_value << 2) | 3; // IP_TOS field: (DSCP << 2) | ECN
    if (setsockopt(sockfd, IPPROTO_IP, IP_TOS, &option_value, sizeof(option_value)) < 0) {
        std::cerr << "Error setting DSCP value" << std::endl;
        close(sockfd);
        return 1;
    }

    // 设置服务器地址
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(80);
    inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

    // 连接到服务器
    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        std::cerr << "Error connecting to server" << std::endl;
        close(sockfd);
        return 1;
    }

    // 在此处进行数据传输...

    close(sockfd);
    return 0;
}