C++ UDP 组播 Multicast 源码

#include "struct.h" //int datalen; struct sockaddr_in localSock; struct ip_mreq group; int GetSOCK_DGRAM(unsigned short port) { int sd = socket(AF_INET, SOCK_DGRAM, 0); if(sd < 0){ perror("Opening datagram socket error"); exit(1); } else printf("Opening datagram socket....OK.\n"); { int reuse = 1; if(setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, (char *)&reuse, sizeof(reuse)) < 0){ perror("Setting SO_REUSEADDR error"); close(sd); exit(1); } else printf("Setting SO_REUSEADDR...OK.\n"); } int ret = 0; memset((char *) &localSock, 0, sizeof(localSock)); localSock.sin_family = AF_INET; localSock.sin_port = port; localSock.sin_addr.s_addr = INADDR_ANY; if(bind(sd, (struct sockaddr*)&localSock, sizeof(localSock))){ perror("Binding datagram socket error"); close(sd); exit(1); } else { printf("Binding datagram socket...OK.\n"); } //setsockopt(sd,SOL_SOCKET,SO_RCVBUF,(const char*)&nRecvBuf,sizeof(int)); group.imr_multiaddr.s_addr = inet_addr(GROUP_IP);//相当于组名 group.imr_interface.s_addr = inet_addr(LOCAL_IP);//自己的ip if(setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&group, sizeof(group)) < 0){ perror("Adding multicast group error"); close(sd); exit(1); } else printf("Adding multicast group...OK.\n"); //datalen = recvSize; return sd; } int InitSocket() { #ifdef WIN32 int Error; WORD VersionRequested; WSADATA WsaData; VersionRequested=MAKEWORD(2,2); Error=WSAStartup(VersionRequested,&WsaData); //启动WinSock2 if(Error!=0) { return 0; } else { if(LOBYTE(WsaData.wVersion)!=2||HIBYTE(WsaData.wHighVersion)!=2) { WSACleanup(); return 0; } } #endif return 0; } int main(int argc, char *argv[]) { printf("UdeClientStart().group=%s,port=%d,locol=%s,build=%s\n", GROUP_IP, PORT, LOCAL_IP, __TIME__); InitSocket(); int sd = GetSOCK_DGRAM(htons(PORT)); struct sockaddr_in from; int fromlen = sizeof(from); int nRecvLen = 1; const int FILE_LEN = 1024*10; //char* bufWrite = new char[FILE_LEN]; const int recvSize = 1024*1000; unsigned char* databuf = new unsigned char[recvSize]; int nLastSeq = 0; static double s_nRecvTotal = 0.0; int lostPacke = 0; int lostTimes = 0; while(1)//nRecvLen > 0 { nRecvLen = recvfrom(sd, (char*)databuf, recvSize, 0, (struct sockaddr*)&from, (socklen_t*)&fromlen) ;//read if (nRecvLen > 0) { // continue; } printf("recv=%s\n", databuf); } return 0; }