SOCKET之UDP跨网段广播返回服务端主机名和所有IP.doc

SOCKET之UDP跨网段广播返回服务端主机名和所有IP/ myudpclient.cpp : 定义控制台应用程序的入口点。/#pragma once#include stdafx.h#include targetver.h#include #include #include #include #include #include /#include /#include /#include /#include /#include #pragma comment ( lib, ws2_32.lib )#include using namespace std;#define MAXLINE 1024#define SERV_PORT 4000void ShowMessage(char *buff)/处理接受到的报文char arrayINFO10MAXLINE=0;/存放数据的数组，第一个为返回的客户端名称，若与本机名称相同，则接收。第二个为服务端名称，其后为其IPint j=0,k=0;int i; for(i = 0;buffi;i+)if(buffi=?)strncpy(arrayINFOj,&buffk,i-k);k=i+1;j+;strncpy(arrayINFOj,&buffk,i);char localHostNameMAXLINE=0;gethostname(localHostName,MAXLINE);if(strcmp(localHostName,arrayINFO0)=0)coutendl服务器主机名:arrayINFO1 接受到数据，其共有j-1个IPendl;for(int temi=1;temij;temi+)cout第temi个ip :arrayINFOtemi+1endl; int main()WSADATA wsaData;if (WSAStartup(MAKEWORD(2,2),&wsaData)!=NO_ERROR)std:coutInitialization failedstd:endl;elsecoutinitialization successendl;/创建UDP的套接字SOCKET socket1=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);if(INVALID_SOCKET = socket1) coutsocket errorendl;elsecoutsocket successendl; / 用来发送和接收数据 struct sockaddr_in client;client.sin_family = AF_INET; client.sin_port = htons(4000); client.sin_addr.s_addr = INADDR_BROADCAST;/client.sin_addr.S_un.S_addr = inet_addr(255.255.255.255);/和上面一条语句一个意思，不过要对应好子网掩码/设置该套接字为广播类型， bool bOpt = true; setsockopt(socket1,SOL_SOCKET,SO_BROADCAST,(char*)&bOpt,sizeof(bOpt); int nAddrLen = sizeof(SOCKADDR); char buffMAXLINE = ; int nLoop = 0; int err;while(1) /广播一条消息char localHostNameMAXLINE=0;gethostname(localHostName,MAXLINE);char SendMesMAXLINE=0;coutendl请输入需要传输的数据:;cin.getline(SendMes,MAXLINE,n);strcat(localHostName,?);strcat(localHostName,SendMes);/将本主机信息和发送的信息绑定到一个数组/coutIP发送前inet_ntoa(client.sin_addr)endl;int nSendSize = sendto(socket1,localHostName,strlen(localHostName),0,(SOCKADDR*)&client,sizeof(SOCKADDR);if(SOCKET_ERROR = nSendSize)err = WSAGetLastError(); coutsend 主机名 error!, error code iserrendl; elsecout发送成功endl;/coutIP发送后inet_ntoa(client.sin_addr)endl;/发送前发送后不变/等待客户端返回其主机名和IP/设置超时信息int nTimeOut = 1500 ; setsockopt(socket1,SOL_SOCKET,SO_RCVTIMEO,(char *)&nTimeOut,sizeof(int);while(1)char buff1024=0;recvfrom(socket1,buff,MAXLINE,0,(SOCKADDR*)&client,&nAddrLen); client.sin_addr.s_addr = INADDR_BROADCAST;if(strlen(buff)=0)/printf(接收超时!); break;elseShowMessage(buff);client.sin_addr.s_addr = INADDR_BROADCAST;/须重新初始化广播地址，不然其会记录为上一次发送的地址，就不再sendto广播了/while1结束/ myudpserver.cpp : 定义控制台应用程序的入口点。/#include stdafx.h#pragma comment ( lib, ws2_32.lib )#include using namespace std;#define MAXLINE 1024#define SERV_PORT 4000void GetInfo(char* SendInfo)/取得本地计算机名和IPchar localHostNameMAXLINE=0;gethostname(localHostName,MAXLINE);/根据计算机名取得所有IPstrcat(SendInfo,localHostName);hostent* pHostent = gethostbyname(localHostName);hostent& he=*pHostent; sockaddr_in sa; for (int nAdapter=0; he.h_addr_listnAdapter; nAdapter+) memcpy ( &sa.sin_addr.s_addr, he.h_addr_listnAdapter,he.h_length);LPCSTR ip=inet_ntoa(sa.sin_addr);string strIP;strIP=ip;char localIPMAXLINE=0;strcpy(localIP,strIP.c_str();/将string字符串转化成数组，用localIP存储。strcat(SendInfo,?);strcat(SendInfo,localIP); void ShowMessage(char *buff,char *ClientHName)/处理接受到的报文char arrayINFO2MAXLINE=0;/存放数据的数组，第一个为主机名，第二个消息int j=0,k=0;int i; for(i = 0;buffi;i+)if(buffi=?)strncpy(arrayINFO0,buff,i);break;strncpy(arrayINFO1,&buffi+1,strlen(buff);cout接受到arrayINFO0发来的消息:arrayINFO1endl;strcat(ClientHName,arrayINFO0);int main()WSADATA wsaData;if (WSAStartup(MAKEWORD(2,2),&wsaData)!=NO_ERROR)std:coutInitialization failedstd:endl;elsecoutinitialization successendl;/创建socketSOCKET socket1=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);if(socket1=INVALID_SOCKET)coutsocket failendl;else coutsocket successendl;/设置该套接字为广播类型 bool bOpt = true; / 用来绑定套接字struct sockaddr_in server;server.sin_family=AF_INET;server.sin_port=htons(4000); /监听端口/server.sin_addr.s_addr = 0;server.sin_addr.s_addr = htonl(INADDR_ANY);setsockopt(socket1,SOL_SOCKET,SO_BROADCAST,(char*)&bOpt,sizeof(bOpt);/绑定套接字if(bind(socket1,(struct sockaddr*)&server,sizeof(SOCKADDR)=-1) coutbind failendl;else coutbind successendl;/取得本机信息char SendInfoMAXLINE=0;GetInfo(SendInfo);/ 用来发送和接收数据 struct sockaddr_in client;client.sin_family = AF_INET; client.sin_port = htons(4000); client.sin_addr.s_addr = INADDR_BROADCAST; /int err; int nAddrLen = sizeof(SOCKADDR); while(1) char buffMAXLINE=0;char ClientHNameMAXLINE=0;/客户端主机名cout正在监听.endl;/接收客户端传来的消息if(recvfrom(socket1,buff,MAXLINE,0,(SOCKADDR*)&client,&nAddrLen)!=SOCKET_ERROR)ShowMessage(buff,ClientHName);client.sin_addr.s_addr = INADDR_BROADCAST;/没有这句话的话，sendto不能跨到其他网段。意思是必须得广播才能跨网段/strcat(SendInfo,ClientHName);/将客户端主机名并入SendInfo数组strcat(ClientHName,?);strcat(ClientHName,SendInfo);/将客户端主机名并入ClientHName数组，