[原创]shootingstars兄长的P2pServer主要代码分析

[shootingstars]P2P 之 UDP穿透NAT的原理与实现（附源代码）

[原创]关于UUCall3网络电话协议分析

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2007/12/17 发表时间

11:03

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huzhangyou2002

服务器开发

标题：P2pServer主要代码分析
关键字：p2p server 分析服务器服务器开发服务器设计服务器开发设计服务器设计开发

/* P2P 程序服务端
 * 
 * 文件名：P2PServer.c
 *
 * 日期：2004-5-21
 *
 * 作者：shootingstars(zhouhuis22@sina.com)
 *
 */
#pragma comment(lib, "ws2_32.lib") //lib包含，如果不包含可能会出现.obj无法找到相应文件

#include "windows.h"
#include "..\proto.h"
#include "..\Exception.h"

//定义UserList,保存用户列表
UserList ClientList;

//初始化Socket相关信息
void InitWinSock()
{
  WSADATA wsaData;

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));
    
  }
}
//创建Socket
SOCKET mksock(int type)
{
  SOCKET sock = socket(AF_INET, type, 0);
  if (sock < 0)
  {
        printf("create socket error");
    throw Exception("");
  }
  return sock;
}
//从ClientList中通过username获取用户
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");
}
//主函数循环
int main(int argc, char* argv[])
{
                //异常处理
  try{
                                //初始化
    InitWinSock();
    
    SOCKET Primary<a href="http://www.server-development.cn/go.php/tags/udp/" target="_blank" title="http://www.server-development.cn/go.php/tags/udp/" class="mykeyword">UDP</a>;
    PrimaryUDP = mksock(SOCK_DGRAM);
                               //设置sockaddr_in结构体
    sockaddr_in local;
    local.sin_family=AF_INET;
    local.sin_port= htons(SERVER_PORT); 
    local.sin_addr.s_addr = htonl(INADDR_ANY);
                                //绑定socket
    int nResult=bind(PrimaryUDP,(sockaddr*)&local,sizeof(sockaddr));
    if(nResult==SOCKET_ERROR)
      throw Exception("bind error");

sockaddr_in sender;
    stMessage recvbuf;
    memset(&recvbuf,0,sizeof(stMessage));

// 开始主循环.
    // 主循环负责下面几件事情:
    // 一:读取客户端登陆和登出消息,记录客户列表
    // 二:转发客户p2p请求
                                //主循环
    for(;;)
    {
      int dwSender = sizeof(sender);
      int ret = recvfrom(PrimaryUDP, (char *)&recvbuf, sizeof(stMessage), 0, (sockaddr *)&sender, &dwSender);
      if(ret <= 0)
      {
        printf("recv error");
        continue;
      }
      else
      {
        int messageType = recvbuf.iMessageType;
        switch(messageType){
                                                               //协议体，包含Login,Logout,P2PTRANS,GETALLUSER
        case LOGIN:
          {
            //  将这个用户的信息记录到用户列表中
            printf("has a user login : %s\n", recvbuf.message.loginmember.userName);
            stUserListNode *currentuser = new stUserListNode();
            strcpy(currentuser->userName, recvbuf.message.loginmember.userName);
            currentuser->ip = ntohl(sender.sin_addr.S_un.S_addr);
            currentuser->port = ntohs(sender.sin_port);
            
            ClientList.push_back(currentuser);

// 发送已经登陆的客户信息
            int nodecount = (int)ClientList.size();
            sendto(PrimaryUDP, (const char*)&nodecount, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));
            for(UserList::iterator UserIterator=ClientList.begin();
                UserIterator!=ClientList.end();
                ++UserIterator)
            {
              sendto(PrimaryUDP, (const char*)(*UserIterator), sizeof(stUserListNode), 0, (const sockaddr*)&sender, sizeof(sender)); 
            }

break;
          }
        case LOGOUT:
          {
            // 将此客户信息删除
            printf("has a user logout : %s\n", recvbuf.message.logoutmember.userName);
            UserList::iterator removeiterator = NULL;
            for(UserList::iterator UserIterator=ClientList.begin();
              UserIterator!=ClientList.end();
              ++UserIterator)
            {
              if( strcmp( ((*UserIterator)->userName), recvbuf.message.logoutmember.userName) == 0 )
              {
                removeiterator = UserIterator;
                break;
              }
            }
            if(removeiterator != NULL)
              ClientList.remove(*removeiterator);
            break;
          }
        case P2PTRANS:
          {
            // 某个客户希望服务端向另外一个客户发送一个打洞消息
            printf("%s wants to p2p %s\n",inet_ntoa(sender.sin_addr),recvbuf.message.translatemessage.userName);
            stUserListNode node = GetUser(recvbuf.message.translatemessage.userName);
            sockaddr_in remote;
            remote.sin_family=AF_INET;
            remote.sin_port= htons(node.port); 
            remote.sin_addr.s_addr = htonl(node.ip);

in_addr tmp;
            tmp.S_un.S_addr = htonl(node.ip);
            printf("the address is %s,and port is %d\n",inet_ntoa(tmp), node.port);

stP2PMessage transMessage;
            transMessage.iMessageType = P2PSOMEONEWANTTOCALLYOU;
            transMessage.iStringLen = ntohl(sender.sin_addr.S_un.S_addr);
            transMessage.Port = ntohs(sender.sin_port);
                        
            sendto(PrimaryUDP,(const char*)&transMessage, sizeof(transMessage), 0, (const sockaddr *)&remote, sizeof(remote));

break;
          }
        
        case GETALLUSER:
          {
            int command = GETALLUSER;
            sendto(PrimaryUDP, (const char*)&command, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));

int nodecount = (int)ClientList.size();
            sendto(PrimaryUDP, (const char*)&nodecount, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));

for(UserList::iterator UserIterator=ClientList.begin();
                UserIterator!=ClientList.end();
                ++UserIterator)
            {
              sendto(PrimaryUDP, (const char*)(*UserIterator), sizeof(stUserListNode), 0, (const sockaddr*)&sender, sizeof(sender)); 
            }
            break;
          }
        }
      }
    }

}
  catch(Exception &e)
  {
    printf(e.GetMessage());
    return 1;
  }

return 0;
}

/* P2P 程序传输协议
 * 
 * 日期：2004-5-21
 *
 * 作者：shootingstars(zhouhuis22@sina.com)
 *
 */

#pragma once
#include <list>

// 定义iMessageType的值
#define LOGIN 1
#define LOGOUT 2
#define P2PTRANS 3
#define GETALLUSER  4

// 服务器端口
#define SERVER_PORT 2280

// Client登录时向服务器发送的消息
struct stLoginMessage
{
  char userName[10];
  char password[10];
};

// Client注销时发送的消息
struct stLogoutMessage
{
  char userName[10];
};

// Client向服务器请求另外一个Client(userName)向自己方向发送UDP打洞消息
struct stP2PTranslate
{
  char userName[10];
};

// Client向服务器发送的消息格式
struct stMessage
{
  int iMessageType;
  union _message
  {
    stLoginMessage loginmember;
    stLogoutMessage logoutmember;
    stP2PTranslate translatemessage;
  }message;
};

// 客户节点信息
struct stUserListNode
{
  char userName[10];
  unsigned int ip;
  unsigned short port;
};

// Server向Client发送的消息
struct stServerToClient
{
  int iMessageType;
  union _message
  {
    stUserListNode user;
  }message;

};

//======================================
// 下面的协议用于客户端之间的通信
//======================================
#define P2PMESSAGE 100               // 发送消息
#define P2PMESSAGEACK 101            // 收到消息的应答
#define P2PSOMEONEWANTTOCALLYOU 102  // 服务器向客户端发送的消息
                                     // 希望此客户端发送一个UDP打洞包
#define P2PTRASH        103          // 客户端发送的打洞包，接收端应该忽略此消息

// 客户端之间发送消息格式
struct stP2PMessage
{
  int iMessageType;
  int iStringLen;         // or IP address
  unsigned short Port; 
};

using namespace std;
typedef list<stUserListNode *> UserList;