linux+tcp设置包大小

net.ipv4.tcp_mtu_probing = 1
net.ipv4.ip_local_port_range = "1024 65535"
net.ipv4.tcp_rmem = "4096 87380 16777216"
net.ipv4.tcp_wmem = "4096 65536 16777216"

ethtool -g eth0
ethtool -G eth0 rx 1024 tx 1024

int sockfd;
int sendbuf = 1024 * 1024; // 1MB
int recvbuf = 1024 * 1024; // 1MB

sockfd = socket(AF_INET, SOCK_STREAM, 0);
setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &sendbuf, sizeof(sendbuf));
setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &recvbuf, sizeof(recvbuf));

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

int main() {
    int sockfd;
    struct sockaddr_in server_addr;
    char buffer[1024];
    int sendbuf = 1024 * 1024; // 1MB
    int recvbuf = 1024 * 1024; // 1MB

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &sendbuf, sizeof(sendbuf));
    setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &recvbuf, sizeof(recvbuf));

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(8080);
    inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        close(sockfd);
        exit(EXIT_FAILURE);
    }

    strcpy(buffer, "Hello, Server!");
    send(sockfd, buffer, strlen(buffer), 0);

    memset(buffer, 0, sizeof(buffer));
    recv(sockfd, buffer, sizeof(buffer), 0);
    printf("Received: %s\n", buffer);

    close(sockfd);
    return 0;
}