TCP 指定源端口

轉載，原文地址：http://blog.csdn.net/liangxiaozhang/article/details/8267854

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <arpa/inet.h>
#include <sys/socket.h>

int main(){
    int sockfd = socket(AF_INET,SOCK_STREAM,0);
    if(sockfd==-1)perror("sock");
    struct sockaddr_in mine,dest;

    bzero(&mine,sizeof(mine));
    mine.sin_family = AF_INET;
    mine.sin_port = htons(3334);
    inet_pton(AF_INET,"192.168.1.100",&mine.sin_addr);

    bzero(&dest,sizeof(dest));
    dest.sin_family = AF_INET;
    dest.sin_port = htons(9999);
    inet_pton(AF_INET,"192.168.1.100",&dest.sin_addr);

    int b = bind(sockfd,(struct
sockaddr*)&mine,sizeof(mine));
    if(b==-1)perror("");

    int c = connect(sockfd,(struct
sockaddr*)&dest,sizeof(dest));
    if(c!=0)perror("");

    close(sockfd);

}

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <strings.h>

int main(){
    int sockfd = socket(AF_INET,SOCK_STREAM,0);
    struct sockaddr_in addr;
    bzero(&addr,sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(9999);
    inet_pton(AF_INET,"192.168.1.100",&addr.sin_addr);

    bind(sockfd,(struct
sockaddr*)&addr,sizeof(addr));
    listen(sockfd,5);
    while(1){
        struct sockaddr_in c_addr;
        int c_len = sizeof(c_addr);
        bzero(&c_addr,c_len);
        int c = accept(sockfd,(struct
sockaddr*)&addr,&c_len);
        if(c==-1)perror("");
        char ip[40]={0};
        int port;
        inet_ntop(AF_INET,&addr.sin_addr,ip,40);
        port = ntohs(addr.sin_port);
        printf("from %s:%d\n",ip,port);
        close(c);

    }

}