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