peercachefinder.cpp

电驴的源代码

//this file is part of eMule
//Copyright (C)2004 Merkur ( [e-mail] / http://www.emule-project.net )
//
//This program is free software; you can redistribute it and/or
//modify it under the terms of the GNU General Public License
//as published by the Free Software Foundation; either
//version 2 of the License, or (at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software

// notes to myself, remove before release :)

#include "StdAfx.h"
#include <windns.h>
#include "peercachefinder.h"
#include "emule.h"
#include "emuledlg.h"
#include "otherfunctions.h"
#include "Preferences.h"
#include "md5sum.h"
#include "version.h"
#include <crypto51/rsa.h>
#include <crypto51/integer.h>

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif


#define PCBASELOCATION	"edcache.p2p."
#define RETRYDAYS		2
#define SIGNATURELENGTH 256

static char _acDNSBuffer[MAXGETHOSTSTRUCT];

static const uint16 anPeerCachPorts[3] = {4662, 1214, 80};

static const uchar achVerify_Key[256] = {
    0xCE, 0x9A, 0x90, 0x08, 0x47, 0xE7, 0x1E, 0x15, 0x94, 0xFD, 0x65, 0xC7, 0x82, 0xF9, 0xB2, 
    0xB7, 0xB7, 0x6A, 0xF2, 0x4A, 0x31, 0x08, 0xFC, 0x36, 0x6C, 0xB1, 0xD9, 0x3F, 0x3B, 0x94, 0x6B, 
    0xC4, 0x55, 0x39, 0xAF, 0x53, 0x4D, 0x78, 0xE7, 0x1A, 0xE9, 0x83, 0x34, 0x1D, 0x6C, 0xE3, 0xEF, 
    0xAD, 0x56, 0x88, 0x0D, 0x38, 0x94, 0x86, 0x0F, 0x81, 0x7C, 0x9C, 0x21, 0xCF, 0x49, 0xDA, 0xE8, 
    0x13, 0x38, 0x30, 0x88, 0xBD, 0x6A, 0xCE, 0x66, 0x4C, 0xB0, 0x36, 0x3E, 0x43, 0x0B, 0x74, 0x1F, 
    0xCC, 0xA8, 0xB6, 0x7A, 0xC9, 0xEE, 0x45, 0xBD, 0xB6, 0x2C, 0x55, 0xA7, 0x8E, 0x20, 0x65, 0x60, 
    0x54, 0x0B, 0xBF, 0x68, 0x99, 0x4B, 0x30, 0x69, 0x16, 0xF7, 0xB7, 0x6E, 0xFC, 0x4E, 0x4B, 0x4F, 
    0xD8, 0x28, 0x56, 0x4E, 0xC2, 0xCE, 0x91, 0x0C, 0x74, 0xFB, 0xAE, 0x79, 0xAB, 0x86, 0x03, 0xEA, 
    0x35, 0x92, 0xB1, 0x10, 0x4B, 0x7F, 0xF2, 0xA9, 0x39, 0x56, 0xDB, 0xFF, 0x83, 0x5E, 0x44, 0x8F, 
    0xF2, 0x41, 0x61, 0x62, 0x74, 0x36, 0xB3, 0xCF, 0x3E, 0xE5, 0xAC, 0x0B, 0x04, 0x1B, 0x2B, 0x59, 
    0x81, 0x8A, 0xFC, 0x80, 0xC5, 0x4B, 0x36, 0x2E, 0x5F, 0xD0, 0xD3, 0x66, 0x7B, 0x40, 0xD3, 0x82, 
    0x57, 0xF7, 0xA5, 0x05, 0x8D, 0xA9, 0xC9, 0xEE, 0xA8, 0x5F, 0x82, 0x5F, 0xD5, 0x4B, 0xBB, 0x00, 
    0x4D, 0xA3, 0xD8, 0x72, 0x48, 0x84, 0xC0, 0x4B, 0x59, 0x6E, 0xDC, 0x49, 0xCF, 0x00, 0xDD, 0x7C, 
    0xF8, 0xB7, 0xAC, 0x7A, 0xD8, 0x43, 0x6F, 0xA4, 0x21, 0x51, 0x93, 0xDF, 0x58, 0x9A, 0xC1, 0xC7, 
    0x77, 0x45, 0xD7, 0xBE, 0x9B, 0x55, 0x0F, 0x2E, 0xC9, 0xD5, 0x85, 0x8F, 0xB5, 0xF9, 0xF0, 0x49, 
    0xF6, 0x85, 0x24, 0x7A, 0xA8, 0x74, 0x64, 0xB1, 0x8B, 0x71, 0x63, 0xFC, 0x1F, 0x1B, 0x5E, 0x26, 
    0xF5, 
} ;

CPeerCacheFinder::CPeerCacheFinder()
{
	m_dwPCIP = 0;
	m_PCStatus = PCS_NOINIT;
	m_PCLUState = LUS_NONE;
	m_posCurrentLookUp = 0;
	m_dwMyIP = 0;
	m_bValdited = false;
	m_bNotReValdited = false;
	m_bNotReSearched = false;
	m_nDownloadAttempts = 0;
	m_nFailedDownloads = 0;
	m_nPCPort = 0;
}

CPeerCacheFinder::~CPeerCacheFinder(void)
{

}

void CPeerCacheFinder::Save(){
	if (m_PCStatus > 10){ // permanent errorrange
		if (!m_bNotReSearched){
			thePrefs.SetPeerCacheLastSearch(mktime(CTime::GetCurrentTime().GetLocalTm()));
			thePrefs.SetPeerCacheWasFound(false);
			thePrefs.SetPeerCachePort(0);
		}
	}
	else if (m_PCStatus == PCS_READY){
		if (!m_bNotReValdited){
			thePrefs.SetPeerCacheLastSearch(mktime(CTime::GetCurrentTime().GetLocalTm()));
		}
		thePrefs.SetPeerCachePort(m_nPCPort);
		thePrefs.SetPeerCacheWasFound(true);
	}
}

void CPeerCacheFinder::Init(uint32 dwLastSearch, bool bLastSearchSuccess, bool bEnabled, uint16 nPort){
	if (!bEnabled){
		m_PCStatus = PCS_DISABLED;
	}
	else{
		if (bLastSearchSuccess){ // sanitycheck
			bool bOK = false;
			for (int i = 0; i != ARRSIZE(anPeerCachPorts); i++){
				if(anPeerCachPorts[i] == nPort)
					bOK = true;
			}
			if (!bOK){
				dwLastSearch = 0;
				bLastSearchSuccess = false;
				DEBUG_ONLY(theApp.QueueDebugLogLine(false, _T("Sanitycheck for PeerCache-Port '%u' failed"), nPort));
			}
			else
				m_nPCPort = nPort;
		}

		if (dwLastSearch != 0){
			CTime last(dwLastSearch);
			time_t tLast=safe_mktime(last.GetLocalTm());
			time_t tNow=safe_mktime(CTime::GetCurrentTime().GetLocalTm());
			if ( (difftime(tNow,tLast) / 86400) < RETRYDAYS ){
				if (!bLastSearchSuccess){
					// no retry to find the cache
					m_PCStatus = PCS_NOTFOUND;
					m_bNotReSearched = true;
					DEBUG_ONLY(theApp.QueueDebugLogLine(false, _T("PeerCache: Not starting a search - last failed search is too near")));
					return;
				}
				else{
					// no need to revaldite the cache yet
					m_bValdited = true;
					m_bNotReValdited = true;
					DEBUG_ONLY(theApp.QueueDebugLogLine(false, _T("PeerCache: CacheIdent still valid, not trying to revaldite this time")));
				}
			}
			else
				m_bNotReValdited = false;
		}
		m_bNotReSearched = false;
		SearchForPC();
	}
}

void CPeerCacheFinder::FoundMyPublicIPAddress(uint32 dwIP){
	m_dwMyIP = dwIP;
	if (m_PCStatus == PCS_OWNIPUNKNOWN){
		m_PCStatus = PCS_DOINGLOOKUPS;
		SearchForPC();
	}
}

void CPeerCacheFinder::SearchForPC(){
	switch(m_PCStatus){
		case PCS_NOINIT:
			m_PCStatus = PCS_DOINGLOOKUPS;
		case PCS_DOINGLOOKUPS:
			switch(m_PCLUState){
				case LUS_NONE:
					// ok lets start, base pos first
					m_PCLUState = LUS_BASEPCLOCATION;
					DoLookUp(PCBASELOCATION);
					break;
				case LUS_BASEPCLOCATION:
					// so the first lookup failed, now we need our hostname
					if (m_dwMyIP == 0){
						// we have to wait until we now our IP for a reverse lookup
						m_PCStatus = PCS_OWNIPUNKNOWN;
						break;
					}
					m_PCLUState = LUS_MYHOSTNAME;
					DoReverseLookUp(m_dwMyIP);
					break;
				case LUS_MYHOSTNAME:
					// we should have found the hostname and now start to contruct sublocations to lookup
					m_PCLUState = LUS_EXTPCLOCATION;
					m_posCurrentLookUp = 0;
				case LUS_EXTPCLOCATION:
					ASSERT ( !m_strMyHostname.IsEmpty() );
					// build string
					m_posCurrentLookUp = m_strMyHostname.Find('.',m_posCurrentLookUp+1);
					if (m_posCurrentLookUp == -1 || m_posCurrentLookUp+1 >= m_strMyHostname.GetLength() || m_strMyHostname.Find('.',m_posCurrentLookUp+1) == (-1) ){
						// failed:
						m_PCLUState = LUS_NONE;
						m_PCStatus = PCS_NOTFOUND;
					}
					else{
						DoLookUp(PCBASELOCATION + CStringA(m_strMyHostname.Mid(m_posCurrentLookUp+1)));
					}
					break;
				case LUS_FINISHED:
					if (m_dwMyIP == 0){
						// we have to wait until we now our IP for a reverse lookup
						m_PCStatus = PCS_OWNIPUNKNOWN;
						break;
					}
					if (!m_bValdited){
						m_PCStatus = PCS_VALDITING;
						ValditeDescriptorFile();
					}
					else{
						DEBUG_ONLY(theApp.QueueLogLine(false, GetResString(IDS_PEERCACHE_ENABLED)));
						m_PCStatus = PCS_READY;
					}
					break;
			}
			break;
	}
}

LRESULT CPeerCacheFinder::OnPeerCacheCheckResponse(WPARAM wParam, LPARAM lParam){
	if (m_PCLUState == LUS_MYHOSTNAME){
		if (WSAGETASYNCERROR(lParam) == 0)
		{
			int iBufLen = WSAGETASYNCBUFLEN(lParam);
			if (iBufLen >= sizeof(HOSTENT))
			{
				LPHOSTENT pHost = (LPHOSTENT)_acDNSBuffer;
				m_strMyHostname = pHost->h_name;
				if (!m_strMyHostname.IsEmpty()){
					DEBUG_ONLY(AddDebugLogLine(false, _T("PeerCache: Found my Hostname: %s, continue search"), m_strMyHostname));
					SearchForPC();
					return 0;
				}
			}
		}
		m_PCStatus = PCS_NOTFOUND;
		DEBUG_ONLY(AddDebugLogLine(false, _T("DNS Reverse Lookup for own IP failed, aborting PC search")));

	}
	else{
		if (WSAGETASYNCERROR(lParam) == 0)
		{
			int iBufLen = WSAGETASYNCBUFLEN(lParam);
			if (iBufLen >= sizeof(HOSTENT))
			{
				LPHOSTENT pHost = (LPHOSTENT)_acDNSBuffer;
				if (pHost->h_length == 4 && pHost->h_addr_list && pHost->h_addr_list[0])
				{
					m_dwPCIP = ((LPIN_ADDR)(pHost->h_addr_list[0]))->s_addr;
					DEBUG_ONLY(AddDebugLogLine(false, _T("Found PeerCache IP: %s"), ipstr(m_dwPCIP) ));
					
					m_PCLUState = LUS_FINISHED;
					SearchForPC();
					return 0;
				}
			}
		}
		// no luck, continue search
		DEBUG_ONLY(AddDebugLogLine(false, _T("DNS Lookup for PC, state %i, failed - PC not found yet"), m_PCLUState));
		SearchForPC();
	}
	return 0;
}

void CPeerCacheFinder::DoLookUp(CStringA strHostname){
	if (WSAAsyncGetHostByName(theApp.emuledlg->m_hWnd, WM_PEERCHACHE_RESPONSE, strHostname, _acDNSBuffer, sizeof(_acDNSBuffer)) == 0){
		DEBUG_ONLY(AddDebugLogLine(false, _T("DNS Lookup for PC, state %i, failed (DoLookUP) - PC not found yet"), m_PCLUState));
	}
}

bool CPeerCacheFinder::IsCacheAvailable() const { 
	if(m_nDownloadAttempts > 20 && m_nFailedDownloads > 0){
		if ( (float)(m_nDownloadAttempts/m_nFailedDownloads) < (float)2)
			return false;
	}
	return m_PCStatus == PCS_READY && theApp.GetPublicIP() != 0 && m_nPCPort != 0; 
}


CString ReverseDnsLookup(DWORD dwIP)
{
	CString strHostName;

	HMODULE hLib = LoadLibrary(_T("dnsapi.dll"));
	if (hLib)
	{
		DNS_STATUS (WINAPI *pfnDnsQueryConfig)(DNS_CONFIG_TYPE Config, DWORD Flag, PWSTR pwsAdapterName, PVOID pReserved, PVOID pBuffer, PDWORD pBufferLength);
		DNS_STATUS (WINAPI *pfnDnsQuery)(PCTSTR pszName, WORD wType, DWORD Options, PIP4_ARRAY aipServers, PDNS_RECORD* ppQueryResults, PVOID* pReserved);
		VOID (WINAPI *pfnDnsRecordListFree)(PDNS_RECORD pRecordList, DNS_FREE_TYPE FreeType);

		(FARPROC&)pfnDnsQueryConfig = GetProcAddress(hLib, "DnsQueryConfig");
		(FARPROC&)pfnDnsQuery = GetProcAddress(hLib, _TWINAPI("DnsQuery_"));
		(FARPROC&)pfnDnsRecordListFree = GetProcAddress(hLib, "DnsRecordListFree");

		if (pfnDnsQueryConfig && pfnDnsQuery && pfnDnsRecordListFree)
		{
			// WinXP: We explicitly need to pass the DNS servers to be used to DnsQuery, 
			// otherwise that function will never query a DNS server for the *local* host name.
			IP4_ARRAY* pDnsServers = NULL;
			BYTE aucBuff[16384];
			memset(aucBuff, 0, sizeof aucBuff);
			DWORD dwSize = sizeof aucBuff;
			DNS_STATUS nDnsState = (*pfnDnsQueryConfig)(DnsConfigDnsServerList, FALSE, NULL, NULL, aucBuff, &dwSize);
			if (nDnsState == 0)
			{
				if (dwSize >= 4)
				{
					DWORD dwDnsServers = ((DWORD*)aucBuff)[0];
					if (dwDnsServers >= 1 && dwSize == sizeof(DWORD) + dwDnsServers*sizeof(DWORD))
					{
						UINT uArrSize = sizeof(IP4_ARRAY) + sizeof(IP4_ADDRESS)*dwDnsServers;
						pDnsServers = (IP4_ARRAY*)new BYTE[uArrSize];
						memset(pDnsServers, 0, uArrSize);
						pDnsServers->AddrCount = dwDnsServers;
						for (UINT s = 0; s < dwDnsServers; s++)
							pDnsServers->AddrArray[s] = ((DWORD*)aucBuff)[1+s];
					}
				}
			}
			else{
				if (thePrefs.GetVerbose())
					DEBUG_ONLY(theApp.QueueDebugLogLine(false, _T("ReverseDNS: Failed to get list of DNS servers - %s"), GetErrorMessage(nDnsState, 1)));
			}

			CString strDnsQuery;
			strDnsQuery.Format(_T("%u.%u.%u.%u.IN-ADDR.ARPA"), (dwIP >> 24) & 0xFF, (dwIP >> 16) & 0xFF, (dwIP >> 8) & 0xFF, (dwIP >> 0) & 0xFF);

			// This is a *blocking* call!
			PDNS_RECORD pDnsRecords = NULL;
			nDnsState = (*pfnDnsQuery)(strDnsQuery, DNS_TYPE_PTR, DNS_QUERY_BYPASS_CACHE, pDnsServers, &pDnsRecords, NULL);
			if (nDnsState == 0)
			{
				if (AtlIsValidAddress(pDnsRecords, sizeof(*pDnsRecords) - sizeof(pDnsRecords->Data) + sizeof(pDnsRecords->Data.PTR), FALSE))
				{
					if (AtlIsValidAddress(pDnsRecords->Data.PTR.pNameHost, sizeof(TCHAR), FALSE))
						strHostName = pDnsRecords->Data.PTR.pNameHost;
					(*pfnDnsRecordListFree)(pDnsRecords, DnsFreeRecordListDeep);
				}
			}
			else{
				if (thePrefs.GetVerbose())
					DEBUG_ONLY(theApp.QueueDebugLogLine(false, _T("ReverseDNS: Failed to resolve address \"%s\" - %s"), strDnsQuery, GetErrorMessage(nDnsState, 1)));
			}

			delete[] (BYTE*)pDnsServers;
		}
		FreeLibrary(hLib);
	}

	return strHostName;
}

void CPeerCacheFinder::DoReverseLookUp(uint32 dwIP){
	CPCReverseDnsThread* pThread = (CPCReverseDnsThread*)AfxBeginThread(RUNTIME_CLASS(CPCReverseDnsThread), THREAD_PRIORITY_BELOW_NORMAL, 0, CREATE_SUSPENDED);
	pThread->m_dwIP = dwIP;
	pThread->m_hwndAsyncResult = theApp.emuledlg->m_hWnd;
	pThread->ResumeThread();
}

void CPeerCacheFinder::ValditeDescriptorFile(){
	CPCValditeThread* pValditeThread = (CPCValditeThread*) AfxBeginThread(RUNTIME_CLASS(CPCValditeThread), THREAD_PRIORITY_BELOW_NORMAL,0, CREATE_SUSPENDED);
	pValditeThread->SetValues(this, m_dwPCIP, m_dwMyIP); 
	pValditeThread->ResumeThread();	
}

void	CPeerCacheFinder::AddBannedVersion(CClientVersionInfo cviVersion){
	// Thread safe, due to logic this is not really needed at this time
	// (because noone will access the list while the ValditeThread is running),
	// but better to be on the safe side in case the code changes
	CSingleLock lock(&m_SettingsMutex, TRUE);
	liBannedVersions.Add(cviVersion);
}

void CPeerCacheFinder::AddAllowedVersion(CClientVersionInfo cviVersion){
	CSingleLock lock(&m_SettingsMutex, TRUE);
	liAllowedVersions.Add(cviVersion);