如何在linux C中获得接口的最大带宽？

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>

int main()
{
    int sock = 0, ret = 0;
    struct sockaddr_in serv_addr;
    socklen_t addr_len;
    int bandwidth = 0;

    // 创建socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0)
    {
        printf("Failed to create socket.
");
        return 1;
    }

    // 连接服务器
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    serv_addr.sin_port = htons(1234);

    ret = connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
    if (ret < 0)
    {
        printf("Failed to connect socket.
");
        return 1;
    }

    // 获取接口的带宽限制
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    serv_addr.sin_port = htons(1234);

    addr_len = sizeof(serv_addr);
    ret = getsockopt(sock, SOL_SOCKET, SO_RCVBUF, (char *)&serv_addr, &addr_len);
    if (ret < 0)
    {
        printf("Failed to get socket options.
");
        return 1;
    }

    // 检查获取的带宽限制是否合理
    if (serv_addr.sin_addr.s_addr != INADDR_ANY)
    {
        printf("The bandwidth limit is not 0.
");
        return 1;
    }

    // 释放socket
    close(sock);

    return 0;
}