谁能告诉我如何在 UDP 套接字中设置源端口地址?我的客户端应用程序需要将数据包从 57002 端口发送到服务器端口 58007 .

Can any one tell me how to set the Source port address in the UDP socket ?. My client application needs to send the Packets from the 57002 port to the server port 58007 .

推荐答案

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define DST_PORT    58007
#define SRC_PORT    57002

#define IP      "127.0.0.1"

int main(int argc, char *argv[]) {
    struct sockaddr_in addr, srcaddr;
    int fd;
    char message[] = "Hello, World!";

    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        perror("socket");
        exit(1);
    }

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr(IP);
    addr.sin_port = htons(DST_PORT);

    memset(&srcaddr, 0, sizeof(srcaddr));
    srcaddr.sin_family = AF_INET;
    srcaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    srcaddr.sin_port = htons(SRC_PORT);

    if (bind(fd, (struct sockaddr *) &srcaddr, sizeof(srcaddr)) < 0) {
        perror("bind");
        exit(1);
    }

    while (1) {
        if (sendto(fd, message, sizeof(message), 0, (struct sockaddr *) &addr,
                sizeof(addr)) < 0) {
            perror("sendto");
            exit(1);
        }
        sleep(1);
    }
    return 0;
}