p2p.rar_nat p2p udp

#pragma comment(lib,"ws2_32.lib") #include "windows.h" #include "proto.h" #include "Exception.h" #include <iostream> using namespace std; UserList ClientList; unsigned int Localip; //定义自己的IP地址 #define COMMANDMAXC 256 #define MAXRETRY 5 SOCKET PrimaryUDP; char LocalUserName[10]; char ServerIP[20]; char host_address[256]; bool RecvedACK; void InitWinSock() { WSADATA wsaData; HOSTENT *host_entry; char host_name[256]; if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) { printf("Windows sockets 2.2 startup"); throw Exception(""); } else{ printf("Using %s (Status: %s)\n", wsaData.szDescription, wsaData.szSystemStatus); printf("with API versions %d.%d to %d.%d\n\n", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion), LOBYTE(wsaData.wHighVersion), HIBYTE(wsaData.wHighVersion)); } gethostname(host_name,256); //获取本机名字 host_entry=gethostbyname(host_name); if(host_entry!=0) { wsprintf(host_address,"%d.%d.%d.%d",(host_entry->h_addr_list[0][0]&0x00ff),(host_entry->h_addr_list[0][1]&0x00ff), (host_entry->h_addr_list[0][2]&0x00ff),(host_entry->h_addr_list[0][3]&0x00ff)); } } SOCKET mksock(int type) { SOCKET sock = socket(AF_INET, type, 0); if (sock < 0) { printf("create socket error"); throw Exception(""); } return sock; } stUserListNode GetUser(char *username) { for(UserList::iterator UserIterator=ClientList.begin(); UserIterator!=ClientList.end(); ++UserIterator) { if( strcmp( ((*UserIterator)->userName), username) == 0 ) return *(*UserIterator); } throw Exception("not find this user"); } //绑定socket对象的函数，填入ip，端口后，将socket对象与socket地址对象绑定。 void BindSock(SOCKET sock) { sockaddr_in sin; sin.sin_addr.S_un.S_addr = INADDR_ANY; sin.sin_family = AF_INET; sin.sin_port = htons(CLIENT_PORT); if (bind(sock, (struct sockaddr*)&sin, sizeof(sin)) < 0) throw Exception("bind error"); } //总目的：写上自己的用户名，服务器的ip地址后，登陆服务器 bool ConnectToServer(SOCKET sock,char *username, char *serverip) { sockaddr_in remote;//用来保存服务器的地址信息 remote.sin_addr.S_un.S_addr = inet_addr(serverip); remote.sin_family = AF_INET; remote.sin_port = htons(SERVER_PORT); stMessage sendbuf; //用来发送LOGIN消息，告诉服务器新用户登陆 sendbuf.iMessageType = LOGIN; strncpy(sendbuf.message.loginmember.userName, username, 10); //消息里面保存了用户名，在这里填上自己写的用户名 sendto(sock, (const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr*)&remote,sizeof(remote));//发送LOGIN消息到服务端 int usercount; unsigned short loggingtag; int fromlen = sizeof(remote); int iread = recvfrom(sock, (char *)&loggingtag, sizeof(unsigned short), 0, (sockaddr *)&remote, &fromlen);//接受loggingtag消息，这个标记为0时表示名字被占用，为1标记未被占用 if(iread<=0) { throw Exception("Login error\n"); } if(!loggingtag) { printf("Sorry, your nickname has been used.\n"); return false; //标记为0时以false退出 } iread = recvfrom(sock, (char *)&usercount, sizeof(int), 0, (sockaddr *)&remote, &fromlen);//服务端接受发来的用户数量。 //总目的：登录到服务端后，接收服务端发来的已经登录的用户的信息 cout<<"Have "<<usercount<<" users logined server:"<<endl; for(int i = 0;i<usercount;i++) { stUserListNode *node = new stUserListNode; recvfrom(sock, (char*)node, sizeof(stUserListNode), 0, (sockaddr *)&remote, &fromlen); ClientList.push_back(node); cout<<"Username:"<<node->userName<<endl; if(strcmp(node->userName,username)==0) //看到自己的用户名时，记录自己的外网IP { Localip=node->ip; } in_addr tmp; tmp.S_un.S_addr = htonl(node->ip); cout<<"UserIP:"<<inet_ntoa(tmp)<<endl; cout<<"UserPort:"<<node->port<<endl; cout<<""<<endl; } return true; } void OutputUsage() { cout<<"You can input you command:\n" <<"Command Type:\"send\",\"exit\",\"getu\"\n" <<"Example : send Username Message\n" <<" exit\n" <<" getu\n" <<endl; } //发送一个消息给某个用户C,直接向C的外网IP发送消息，如果此前没有联系过,那么此消息将无法发送，发送端等待超时。超时后，发送端将发送一个请求信息到服务端，要求服务端发送给C一个请求，请求C给本机发送打洞消息,以上将重复MAXRETRY次 bool SendMessageTo(char *UserName, char *Message) { char realmessage[512]; //保存要发送的内容 unsigned int UserIP; unsigned short UserPort; bool FindUser = false; sockaddr_in server; //定义服务器信息 server.sin_addr.S_un.S_addr = inet_addr(ServerIP); server.sin_family = AF_INET; server.sin_port = htons(SERVER_PORT); //通过输入的Username在Clientlist中寻找对应的用户信息 for(UserList::iterator UserIterator=ClientList.begin(); UserIterator!=ClientList.end(); ++UserIterator) { if( strcmp( ((*UserIterator)->userName), UserName) == 0 ) //找到对应名称的用户 { UserIP = (*UserIterator)->ip; UserPort = (*UserIterator)->port; if(UserIP==Localip) //当发现对方跟自己的外网ip一样的时候，就证明对方跟自己是同一个局域网 { stMessage getlocalipmessage; getlocalipmessage.iMessageType=GETLOCALUSER; //发现对方的外网IP跟自己一样，那么就发送消息给服务器通知对方发送对方内网IP strncpy(getlocalipmessage.message.logoutmember.userName, UserName, 10); sendto(PrimaryUDP, (const char*)&getlocalipmessage, sizeof(getlocalipmessage), 0, (const sockaddr*)&server, sizeof(server)); while((*UserIterator)->Localornot==0) //当localornot=0，说明还未接受到对方的内网信息，继续等待 { Sleep(100); //等待对方的内网IP的到来，到来后localornot被改成1 } UserPort = (*UserIterator)->port; //设置成对方的内网端口 UserIP = (*UserIterator)->ip; //设置成对方的内网ip } FindUser = true; } } if(!FindUser) return false; memset(realmessage,0,256); memcpy(realmessage,LocalUserName,strlen(LocalUserName)); strcat(realmessage," says: "); strcat(realmessage, Message); for(int i=0;i<MAXRETRY;i++) { RecvedACK = false; //当RecvedACK为false的时候，表示从来没跟指定用户联系过。True则代表联系过了。 sockaddr_in remote; //定义socket地址对象，保存对方的地址 remote.sin_addr.S_un.S_addr = htonl(UserIP); remote.sin_family = AF_INET; remote.sin_port = htons(UserPort); stP2PMessage MessageHead; //定义P2P消息对象，这里类型为P2PMESSAGE。这个P2P消息对象只包括发送内容的长度 MessageHead.iMessageType = P2PMESSAGE; MessageHead.iStringLen = (int)strlen(realmessage)+1; int isend = sendto(PrimaryUDP, (const char *)&MessageHead, sizeof(MessageHead), 0, (const sockaddr*)&remote, sizeof(remote)); //发送P2P消息给指定用户，让对方知道是P2P消息，并且知道内容的长度 isend = sendto(PrimaryUDP, (const char *)&realmessage, MessageHead.iStringLen, 0, (const sockaddr*)&remote, sizeof(remote)); //发送realmessage给指定用户，对方已经知道该消息有多长 //等待RecvedACK状态的修改，当线程接受到指定用户的消息后，就会改它。这时候表示已经跟指定用户联系过了。 for(int j=0;j<10;j++) { if(RecvedACK) return true; //一旦是True了，说明联系过了，那么以上realmessage是发送成功了，所以结束返回这个函数了。 else Sleep(300); //一旦是false了，说明并没联系过，那么以上realmessage是发送失败了，所以要发送打洞命令给指定用户。 } //总目的：发送请求信息给服务器，要服务器告诉指定用户打个洞过来 stMessage transMessage; transMessage.iMessageType = P2PTRANS; //这个消息类型定义为打洞命令 strcpy(transMessage.message.translatemessage.userName, UserName);//填写指定用户的用户名，好让服务器知道让哪个用户打洞