windows網絡編程-C語言實現簡單的UDP協議聊天
阿新 • • 發佈：2017-12-28
無連接 ipv4地址 ast 電腦 tdi data rcp proto 生生
與TCP協議下編寫服務端程序代碼類似，但因為是無連接的形式，所以不需要監聽。
這次，我用了一點不同的想法：我建立一個服務端，用了兩個端口和兩個套接字，把服務端作為一個數據轉發的中轉站，使得客戶機之間進行UDP協議下的通信。
服務端代碼：
/**
* UDP/IP 服務器端 Server.c
*/
#include <winsock2.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#define true 1
#define false 0
#define BUFFSIZE 1024
int main(int argc, char**argv)
{
int Ret;
WSADATA wsaData;
SOCKET Socket_1;
SOCKET Socket_2;
SOCKADDR_IN ClientAddr_1;
int ClientAddr_1_Len = sizeof(ClientAddr_1);
SOCKADDR_IN ClientAddr_2;
int ClientAddr_2_Len = sizeof(ClientAddr_2);
unsigned short Port_1 = 5150;
unsigned short Port_2 = 8888;
char sendData[BUFFSIZE];
char recvData[BUFFSIZE];
if((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)
{
printf("WSASTARTUP_ERROR: %d\n", Ret);
exit(1);
}
if((Socket_1 = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET) {
printf("Socket_1_ERROR\n");
exit(1);
}
//將端口變量從主機字節順序轉換位網絡字節順序
ClientAddr_1.sin_family = AF_INET;
ClientAddr_1.sin_port = htons(Port_1);
ClientAddr_1.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
//使用bind將這個地址信息和套接字綁定起來
if(bind(Socket_1, (SOCKADDR *)&ClientAddr_1, ClientAddr_1_Len) == SOCKET_ERROR)
{
printf("BIND_SOCKET_1_ERROR: %d\n", SOCKET_ERROR);
exit(1);
}
if((Socket_2 = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET) {
printf("Socket_2_ERROR\n");
exit(1);
}
//將端口變量從主機字節順序轉換位網絡字節順序
ClientAddr_2.sin_family = AF_INET;
ClientAddr_2.sin_port = htons(Port_2);
ClientAddr_2.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
//使用bind將這個地址信息和套接字綁定起來
if(bind(Socket_2, (SOCKADDR *)&ClientAddr_2, ClientAddr_2_Len) == SOCKET_ERROR)
{
printf("BIND_SOCKET_2_ERROR: %d\n", SOCKET_ERROR);
exit(1);
}
printf("建立連接成功!");
//服務器作為中轉站
//為兩個IP之間互相轉發消息
while(true)
{
//接收IP:192.168.1.2發送的數據
recvfrom(Socket_1, recvData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr_1, &ClientAddr_1_Len);
strcpy(sendData, recvData);
//轉發數據給IP:192.168.1.6
if((Ret = sendto(Socket_2, sendData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr_2, ClientAddr_2_Len)) < 0)
printf("發送失敗!\n");
//接收IP:192.168.1.6發送的數據
recvfrom(Socket_2, recvData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr_2, &ClientAddr_2_Len);
strcpy(sendData, recvData);
//轉發數據給IP:192.168.1.2
if((Ret = sendto(Socket_1, sendData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr_1, ClientAddr_1_Len)) < 0)
printf("發送失敗!\n");
}
closesocket(Socket_1);
closesocket(Socket_2);
//應用程序完成對接的處理後，調用WSACleanup
if(WSACleanup() == SOCKET_ERROR)
{
printf("WSACLEANUP_ERROR: %d\n", WSAGetLastError());
exit(1);
}
system("pause");
return 0;
}
但會有個小問題，首先發送數據的客戶端的數據無法接收，而且要運行成功必須先發送一個信息，再打開第二個客戶端（步驟貌似是這樣，前段時間寫的了，忘記了...= =）
客戶端1代碼：
/**
* UDP/IP 客戶端 Client.c
*/
#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define true 1
#define false 0
#define BUFFSIZE 1024
int main(int argc, char**argv)
{
int Ret;
WSADATA wsaData;
SOCKET SendSocket;
SOCKADDR_IN ClientAddr;
int ClientAddrLen = sizeof(ClientAddr);
unsigned short Port = 5150;
char sendData[BUFFSIZE];
char recvData[BUFFSIZE];
time_t rawtime;
if((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)
{
printf("WSASTARTUP_ERROR: %d\n", Ret);
exit(1);
}
if((SendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET) {
printf("SendSOCKET_ERROR\n");
exit(1);
}
ClientAddr.sin_family = AF_INET;
ClientAddr.sin_port = htons(Port);
ClientAddr.sin_addr.S_un.S_addr = inet_addr("192.168.1.2");//本機IPv4地址
printf("連接到IP:%s 端口:%d\n", inet_ntoa(ClientAddr.sin_addr), ntohs(ClientAddr.sin_port));
puts("-----開始聊天!-----");
//這樣的循環聊天算法硬生生的把UDP協議弄得和前面TCP協議的聊天程序一樣了。。。
//感覺並不太能表現UDP和TCP的區別。。。但我暫時沒有好辦法
while(true)
{
//發送數據
printf("\nC.C.:");
scanf("%s", sendData);
strcat(sendData, "\t____");
time(&rawtime);
strcat(sendData, ctime(&rawtime));
if((Ret = sendto(SendSocket, sendData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr, ClientAddrLen)) < 0)
printf("發送失敗!\n");
//接收數據
if((Ret = recvfrom(SendSocket, recvData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr, &ClientAddrLen)) >= 0)
printf("魯魯:%s\n", recvData);
else
printf("接收失敗!\n");
}
closesocket(SendSocket);
if(WSACleanup() == SOCKET_ERROR)
{
printf("WSACLEANUP_ERROR: %d\n", WSAGetLastError());
exit(1);
}
system("pause");
return 0;
}按照思路即可編寫客戶端2的代碼，代碼也基本一樣，就是端口號不能一樣，需要對應服務端給定的另外一個端口號：
/**
* UDP/IP 客戶端 Client.c
*/
#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define true 1
#define false 0
#define BUFFSIZE 1024
int main(int argc, char**argv)
{
int Ret;
WSADATA wsaData;
SOCKET SendSocket;
SOCKADDR_IN ClientAddr;
int ClientAddrLen = sizeof(ClientAddr);
unsigned short Port = 8888;
char sendData[BUFFSIZE];
char recvData[BUFFSIZE];
time_t rawtime;
if((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)
{
printf("WSASTARTUP_ERROR: %d\n", Ret);
exit(1);
}
if((SendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET) {
printf("SendSOCKET_ERROR\n");
exit(1);
}
ClientAddr.sin_family = AF_INET;
ClientAddr.sin_port = htons(Port);
ClientAddr.sin_addr.S_un.S_addr = inet_addr("192.168.1.2");/**
* 服務端程序的計算機的IPv4地址
* 顯然這整個聊天程序至少需要兩臺電腦，一臺電腦可以為服務端和客戶端，另外再一臺電腦為客戶端。或者有三臺電腦就更不容易糊塗了，一臺作為服務端，另外兩臺都是客戶端。*/
printf("連接到IP:%s 端口:%d\n", inet_ntoa(ClientAddr.sin_addr), ntohs(ClientAddr.sin_port));
puts("-----開始聊天!-----");
while(true)
{
//接收數據
if((Ret = recvfrom(SendSocket, recvData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr, &ClientAddrLen)) >= 0)
printf("C.C.:%s\n", recvData);
else
printf("接收失敗!\n");
//發送數據
printf("\n魯魯:");
scanf("%s", sendData);
strcat(sendData, "\t____");
time(&rawtime);
strcat(sendData, ctime(&rawtime));
if((Ret = sendto(SendSocket, sendData, BUFFSIZE, 0, (SOCKADDR*)&ClientAddr, ClientAddrLen)) < 0)
printf("發送失敗!\n");
}
closesocket(SendSocket);
if(WSACleanup() == SOCKET_ERROR)
{
printf("WSACLEANUP_ERROR: %d\n", WSAGetLastError());
exit(1);
}
system("pause");
return 0;
}windows網絡編程-C語言實現簡單的UDP協議聊天