windows C++ 通过UDP广播获取网络中所有设备ip地址

2019-11-08 03:21:15

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源码下载地址：http://download.csdn.net/detail/dxzysk/9756896

源码使用说明，先在需要获取ip地址的主机上运行server端程序，然后在需要搜索主机的Pc上运行client端程序

本文是windows版，VC++，在VS2010环境下调试成功。有时候需要搜索网络中的设备，机器，服务器等，这就要要用到UDP广播的方式，发送广播命令，广播给网络中的每一个主机，该主机搜到广播命令后，立刻发送给请求端自己的设备信息，这里以IP信息为例子。

思路

在每一个设备中部署sever端程序进行监控，client端发送广播命令，每一个server收到命令后，返回给client自己的ip地址信息，给出代码如下，其中，有部分，比如获取ip地址参考来自网络，尊重原创，乐于分享。

server端(windows控制台程序)

server端监听广播命令”GetIPAddr”，收到命令后就相应

#include <WinSock2.h> #include <stdio.h> #include <iostream> using namespace std; #PRagma comment(lib, "ws2_32.lib") #define GET_HOST_COMMAND "GetIPAddr"const int MAX_BUF_LEN = 255;#define SERVER_PORT 12811 //只返回一个ip地址bool GetLocalIP(char* ip) { //1.初始化wsa WSADATA wsaData; int ret=WSAStartup(MAKEWord(2,2),&wsaData); if (ret!=0) { return false; } //2.获取主机名 char hostname[256]; ret=gethostname(hostname,sizeof(hostname)); if (ret==SOCKET_ERROR) { return false; } //3.获取主机ip HOSTENT* host=gethostbyname(hostname); if (host==NULL) { return false; } //4.转化为char*并拷贝返回 strcpy(ip,inet_ntoa(*(in_addr*)*host->h_addr_list)); return true; } bool doServer(){ int m_nPort = SERVER_PORT; SOCKET sClient; sockaddr_in clientAddr,bindAddr; WSADATA wsdata; //启动SOCKET库，版本为2.0 WORD wVer=MAKEWORD(2,0); if( 0 != WSAStartup(wVer,&wsdata) ) { //AfxMessageBox(L"Not Support Socket2.0"); return false; } //用UDP初始化套接字 sClient=socket(AF_INET,SOCK_DGRAM,0); //设置该套接字为广播类型， BOOL optval=TRUE; bindAddr.sin_family=AF_INET; bindAddr.sin_addr.s_addr=htonl(INADDR_ANY); bindAddr.sin_port=htons(m_nPort); setsockopt(sClient,SOL_SOCKET,SO_BROADCAST,(char FAR *)&optval,sizeof(optval)); bind(sClient,(sockaddr *)&bindAddr,sizeof(sockaddr_in)); int nAddrLen = sizeof(SOCKADDR); char buf[256] = {0}; int fromlength=sizeof(SOCKADDR); printf("the server is start./n"); char ipaddr[30] = {0}; char buff[MAX_BUF_LEN] = ""; if (GetLocalIP(ipaddr)) { sprintf(buff, "my ip is:%s", ipaddr); } else { sprintf(buff, "%s", "my ip is:******"); } //有多个ip地址的时候，这样调用 //IPInfo ips[10]; //int len1 = 0; //GetLocalIPs(ips, 10,&len1); while(true) { int nRet = recvfrom(sClient,buf,256,0,(struct sockaddr FAR *)&clientAddr,(int FAR *)&fromlength); if( SOCKET_ERROR != nRet ) { char *pIPAddr = inet_ntoa(clientAddr.sin_addr); if( NULL != pIPAddr ) { WCHAR wzIPBuffer[32] = {0}; printf("clientAddr: %s/n", pIPAddr); printf("receive command: %s/n", buf); } if (strcmp(buf,GET_HOST_COMMAND) != 0) { printf("the command not valid and was ignored./n", buf); continue; } // 发送数据 int nSendSize = sendto(sClient, buff, strlen(buff), 0, (SOCKADDR*)&clientAddr, nAddrLen); if(SOCKET_ERROR == nSendSize) { int err = WSAGetLastError(); printf("/"sendto/" error!, error code is %d/n", err); return false; } } else { //AfxMessageBox(L"Recv UDP Failed"); } Sleep(1000); } closesocket(sClient); return true;}int main(){ if (!doServer()) { printf("sever returned an error"); return -1; } return 0;}

注意上面是只有一个Ip地址的情况，有的机器可能会有多个IP地址，不同的网络，有线网，无线wifi等，需要获取多个ip地址的方法：

//结构体记录ip信息typedef struct tagIPInfo { char ip[30]; }IPInfo; //获取多个ip地址信息列表bool GetLocalIPs(IPInfo* ips,int maxCnt,int* cnt) { //1.初始化wsa WSADATA wsaData; int ret=WSAStartup(MAKEWORD(2,2),&wsaData); if (ret!=0) { return false; } //2.获取主机名 char hostname[256]; ret=gethostname(hostname,sizeof(hostname)); if (ret==SOCKET_ERROR) { return false; } //3.获取主机ip HOSTENT* host=gethostbyname(hostname); if (host==NULL) { return false; } //4.逐个转化为char*并拷贝返回 *cnt=host->h_length<maxCnt?host->h_length:maxCnt; for (int i=0;i<*cnt;i++) { in_addr* addr=(in_addr*)*host->h_addr_list; strcpy(ips[i].ip,inet_ntoa(addr[i])); } return true; }

client端（windows控制台程序）

client端发送”GetIPAddr”命令，并及时接收client端发过来的信息

//#include "stdafx.h" #include <WinSock2.h> #include <stdio.h> #pragma comment(lib, "ws2_32.lib") const int MAX_BUF_LEN = 255; #define GET_HOST_COMMAND "GetIPAddr"#define CLIENT_PORT 11121#define SERVER_PORT 12811int main() { int nPort = SERVER_PORT; WORD wVersionRequested; WSADATA wsaData; int err; // 启动socket api wVersionRequested = MAKEWORD( 2, 2 ); err = WSAStartup( wVersionRequested, &wsaData ); if ( err != 0 ) { return -1; } if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 ) { WSACleanup( ); return -1; } // 创建socket SOCKET connect_socket; connect_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); if(INVALID_SOCKET == connect_socket) { err = WSAGetLastError(); printf("/"socket/" error! error code is %d/n", err); return -1; } // 用来绑定套接字 SOCKADDR_IN sin; sin.sin_family = AF_INET; sin.sin_port = htons(CLIENT_PORT); sin.sin_addr.s_addr = 0; // 用来从网络上的广播地址接收数据 SOCKADDR_IN sin_from; sin_from.sin_family = AF_INET; sin_from.sin_port = htons(nPort); sin_from.sin_addr.s_addr = INADDR_BROADCAST; //设置该套接字为广播类型， bool bOpt = true; setsockopt(connect_socket, SOL_SOCKET, SO_BROADCAST, (char*)&bOpt, sizeof(bOpt)); // 绑定套接字 err = bind(connect_socket, (SOCKADDR*)&sin, sizeof(SOCKADDR)); if(SOCKET_ERROR == err) { err = WSAGetLastError(); printf("/"bind/" error! error code is %d/n", err); return -1; } printf("the client is start./n"); int nAddrLen = sizeof(SOCKADDR); char buff[MAX_BUF_LEN] = ""; int nLoop = 0; char szMsg[]=GET_HOST_COMMAND; int nLen=sizeof(sin_from); if( SOCKET_ERROR==sendto(connect_socket, szMsg, strlen(szMsg), 0, (sockaddr*)&sin_from, nLen) ) { // AfxMessageBox(L"Send UDP Failed"); return -1; } printf("send broadcast data:%s/n", GET_HOST_COMMAND); while(true) { // 接收数据 int nSendSize = recvfrom(connect_socket, buff, MAX_BUF_LEN, 0, (SOCKADDR*)&sin_from, &nAddrLen); if(SOCKET_ERROR == nSendSize) { err = WSAGetLastError(); printf("/"recvfrom/" error! error code is %d/n", err); return -1; } buff[nSendSize] = '/0'; printf("received ip: %s/n", buff); } return 0; }