eMule电驴eDonkey源代码精辟分析

eMule电驴eDonkey源代码精辟分析最近给一家公司写一个类似电驴的P2P客户端．写的相当的累，但是收获也很大，对电驴的代码进行了深入的分析，现在把所得贡献给大家，网上有很多对电驴协议的分析，其实有些地方是误导大家了，中国的程序员还是很小家子气，就是怕别人超过自己．进入正题，电驴的协议和各种常量参数定义在opcodes.h中，#define OP_EDONKEYHEADER 0xE3#define OP_KADEMLIAHEADER 0xE4这是他的协议码，他大部分的通信包第一个字节都是OP_EDONKEYHEADER 0xE3，这是他的客户端之间的协议#define OP_HELLO 0x01 // 0x10<HASH 16><ID 4><PORT 2><1 Tag_set>#define OP_SENDINGPART 0x46 // <HASH 16><von 4><bis 4><Daten len:(von-bis)>#define OP_REQUESTPARTS 0x47 // <HASH 16><von[3] 4*3><bis[3] 4*3>#define OP_FILEREQANSNOFIL 0x48 // <HASH 16>#define OP_END_OF_DOWNLOAD 0x49 // <HASH 16>#define OP_ASKSHAREDFILES 0x4A // (null)#define OP_ASKSHAREDFILESANSWER 0x4B // <count 4>(<HASH 16><ID 4><PORT 2><1 Tag_set>)[count]#define OP_HELLOANSWER 0x4C // <HASH 16><ID 4><PORT 2><1 Tag_set><SERVER_IP 4><SERVER_PORT 2>#define OP_CHANGE_CLIENT_ID 0x4D // <ID_old 4><ID_new 4>#define OP_MESSAGE 0x4E // <len 2><Message len>#define OP_SETREQFILEID 0x4F // <HASH 16>#define OP_FILESTA TUS 0x50 // <HASH 16><count 2><status(bit array) len:((count+7)/8)> #define OP_HASHSETREQUEST 0x51 // <HASH 16>#define OP_HASHSETANSWER 0x52 // <count 2><HASH[count] 16*count>#define OP_STARTUPLOADREQ 0x54 // <HASH 16>#define OP_ACCEPTUPLOADREQ 0x55 // (null)#define OP_CANCELTRANSFER 0x56 // (null)#define OP_OUTOFPARTREQS 0x57 // (null)#define OP_REQUESTFILENAME 0x58 // <HASH 16> (more correctly file_name_request)#define OP_REQFILENAMEANSWER 0x59 // <HASH 16><len 4><NAME len>#define OP_CHANGE_SLOT 0x5B // <HASH 16>#define OP_QUEUERANK 0x5C // <wert 4> (slot index of the request)#define OP_ASKSHAREDDIRS 0x5D // (null)#define OP_ASKSHAREDFILESDIR 0x5E // <len 2><Directory len>#define OP_ASKSHAREDDIRSANS 0x5F // <count 4>(<len 2><Directory len>)[count]#define OP_ASKSHAREDFILESDIRANS 0x60 // <len 2><Directory len><count 4>(<HASH 16><ID 4><PORT 2><1 Tag_set>)[count]#define OP_ASKSHAREDDENIEDANS 0x61 // (null)这是他的客户端到服务器的通信协议// client <-> server#define OP_LOGINREQUEST 0x01 //<HASH 16><ID 4><PORT 2><1 Tag_set>#define OP_REJECT 0x05 //(null)#define OP_GETSERVERLIST 0x14 //(null)client->server#define OP_OFFERFILES 0x15 // <count 4>(<HASH 16><ID 4><PORT 2><1 Tag_set>)[count]#define OP_SEARCHREQUEST 0x16 // <Query_Tree>#define OP_DISCONNECT 0x18 // (not verified)#define OP_GETSOURCES 0x19 // <HASH 16>#define OP_SEARCH_USER 0x1A // <Query_Tree>#define OP_CALLBACKREQUEST 0x1C // <ID 4>#define OP_QUERY_CHA TS 0x1D // (deprecated not supported by server any longer)#define OP_CHA T_MESSAGE 0x1E // (deprecated not supported by server any longer)#define OP_JOIN_ROOM 0x1F // (deprecated not supported by server any longer)#define OP_QUERY_MORE_RESULT 0x21 // (null)#define OP_SERVERLIST 0x32 // <count 1>(<IP 4><PORT 2>)[count] server->client#define OP_SEARCHRESULT 0x33 // <count 4>(<HASH 16><ID 4><PORT 2><1 Tag_set>)[count]#define OP_SERVERSTA TUS 0x34 // <USER 4><FILES 4>#define OP_CALLBACKREQUESTED 0x35 // <IP 4><PORT 2>#define OP_CALLBACK_FAIL 0x36 // (null notverified)#define OP_SERVERMESSAGE 0x38 // <len 2><Message len>#define OP_CHA T_ROOM_REQUEST 0x39 // (deprecated not supported by server any longer)#define OP_CHA T_BROADCAST 0x3A// (deprecated not supported by server any longer)#define OP_CHA T_USER_JOIN 0x3B // (deprecated not supported by server any longer)#define OP_CHA T_USER_LEA VE 0x3C // (deprecated not supported by server any longer)#define OP_CHA T_USER 0x3D // (deprecated not supported by server any longer)#define OP_IDCHANGE 0x40 // <NEW_ID 4><server_flags 4><primary_tcp_port 4 (unused)><client_IP_address 4>#define OP_SERVERIDENT 0x41 // <HASH 16><IP 4><PORT 2>{1 TAG_SET}#define OP_FOUNDSOURCES 0x42 // <HASH 16><count 1>(<ID 4><PORT 2>)[count]#define OP_USERS_LIST 0x43 // <count 4>(<HASH 16><ID 4><PORT 2><1 Tag_set>)[count]#define OP_GETSOURCES_OBFU 0x23#define OP_FOUNDSOURCES_OBFU 0x44电驴的Socket网络通信部分写的超级搞笑，听我慢慢道来首先EMSocket.h这个类是他的业务通信类可以清楚的看到他的协议头部分是个#define PACKET_HEADER_SIZE 6字节看他的接收是一个静态缓冲区static char GlobalReadBuffer[10*1024*1024];10M大小在接收时候大于8K的使用10M设置，小于8k的使用8Kuint32 recvbufferlimit = 2*ret;if (recvbufferlimit > (10*1024*1024)) {recvbufferlimit = (10*1024*1024);} else if (recvbufferlimit < 8192) {recvbufferlimit = 8192;}if (recvbufferlimit > m_uCurrentRecvBufferSize) {SetSockOpt(SO_RCVBUF, &recvbufferlimit, sizeof(recvbufferlimit), SOL_SOCKET);}int ilen = sizeof(int);GetSockOpt(SO_RCVBUF, &recvbufferlimit, &ilen, SOL_SOCKET);发送的时候Send(1300, 0, true);以１３００ＭＴＵ发送．然后在谈一下他的爷爷，他的爸爸CEncryptedStreamSocket先略去不讲class CEncryptedStreamSocket : public CAsyncSocketEx讲CAsyncSocketEx这个可是电驴最核心的通信类，他直接继承于MFC的祖宗CObject大家注意我这里会讲到电驴SOCKET的命脉所在，这是在整个互联网上还没有人讲的，我最先发布电驴的网络控制是在每一个CAsyncSocketEx中包含了一个窗口句柄，利用这个窗口来派发所有的socket通信控制这是他的SOCKETstruct t_AsyncSocketExData{SOCKET hSocket; //Socket handleint nSocketIndex; //Index of socket, required by CAsyncSocketExHelperWindow} m_SocketData;这是他的那个消息窗口struct t_AsyncSocketExThreadData{CAsyncSocketExHelperWindow *m_pHelperWindow;int nInstanceCount;DWORD nThreadId;} *m_pLocalAsyncSocketExThreadData;这是包含所有窗口句柄的链表//List of the data structures for all threadsstatic struct t_AsyncSocketExThreadDataList{t_AsyncSocketExThreadDataList *pNext;t_AsyncSocketExThreadData *pThreadData;} *m_spAsyncSocketExThreadDataList;然后大家去AsyncSocketEx.cpp中看class CAsyncSocketExHelperWindow的类实现吧，他的所有的SOCKET行为都在这里了．当然这只是通信的开始，后续代码分析我会在今后的博客中为大家见讲解。