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/***************************************************************************
* Copyright (C) 2005 by Joris Guisson *
* joris.guisson@gmail.com *
* *
* 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 Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
***************************************************************************/
#include <util/functions.h>
#include <util/log.h>
#include <torrent/globals.h>
#include "database.h"
using namespace bt;
namespace dht
{
DBItem::DBItem()
{
memset(item,0,9);
time_stamp = bt::GetCurrentTime();
}
DBItem::DBItem(const bt::Uint8* ip_port)
{
memcpy(item,ip_port,6);
time_stamp = bt::GetCurrentTime();
}
DBItem::DBItem(const DBItem & it)
{
memcpy(item,it.item,6);
time_stamp = it.time_stamp;
}
DBItem::~DBItem()
{}
bool DBItem::expired(bt::TimeStamp now) const
{
return (now - time_stamp >= MAX_ITEM_AGE);
}
DBItem & DBItem::operator = (const DBItem & it)
{
memcpy(item,it.item,6);
time_stamp = it.time_stamp;
return *this;
}
///////////////////////////////////////////////
Database::Database()
{
items.setAutoDelete(true);
}
Database::~Database()
{}
void Database::store(const dht::Key & key,const DBItem & dbi)
{
DBItemList* dbl = items.tqfind(key);
if (!dbl)
{
dbl = new DBItemList();
items.insert(key,dbl);
}
dbl->append(dbi);
}
void Database::sample(const dht::Key & key,DBItemList & tdbl,bt::Uint32 max_entries)
{
DBItemList* dbl = items.tqfind(key);
if (!dbl)
return;
if (dbl->count() < max_entries)
{
DBItemList::iterator i = dbl->begin();
while (i != dbl->end())
{
tdbl.append(*i);
i++;
}
}
else
{
Uint32 num_added = 0;
DBItemList::iterator i = dbl->begin();
while (i != dbl->end() && num_added < max_entries)
{
tdbl.append(*i);
num_added++;
i++;
}
}
}
void Database::expire(bt::TimeStamp now)
{
bt::PtrMap<dht::Key,DBItemList>::iterator itr = items.begin();
while (itr != items.end())
{
DBItemList* dbl = itr->second;
// newer keys are inserted at the back
// so we can stop when we hit the first key which is not expired
while (dbl->count() > 0 && dbl->first().expired(now))
{
dbl->pop_front();
}
itr++;
}
}
dht::Key Database::genToken(Uint32 ip,Uint16 port)
{
Uint8 tdata[14];
TimeStamp now = bt::GetCurrentTime();
// generate a hash of the ip port and the current time
// should prevent anybody from crapping things up
bt::WriteUint32(tdata,0,ip);
bt::WriteUint16(tdata,4,port);
bt::WriteUint64(tdata,6,now);
dht::Key token = SHA1Hash::generate(tdata,14);
// keep track of the token, tokens will expire after a while
tokens.insert(token,now);
return token;
}
bool Database::checkToken(const dht::Key & token,Uint32 ip,Uint16 port)
{
// the token must be in the map
if (!tokens.tqcontains(token))
{
Out(SYS_DHT|LOG_DEBUG) << "Unknown token" << endl;
return false;
}
// in the map so now get the timestamp and regenerate the token
// using the IP and port of the sender
TimeStamp ts = tokens[token];
Uint8 tdata[14];
bt::WriteUint32(tdata,0,ip);
bt::WriteUint16(tdata,4,port);
bt::WriteUint64(tdata,6,ts);
dht::Key ct = SHA1Hash::generate(tdata,14);
// compare the generated token to the one received
if (token != ct) // not good, this peer didn't went through the proper channels
{
Out(SYS_DHT|LOG_DEBUG) << "Invalid token" << endl;
return false;
}
// expire the token
tokens.erase(token);
return true;
}
bool Database::tqcontains(const dht::Key & key) const
{
return items.tqfind(key) != 0;
}
void Database::insert(const dht::Key & key)
{
DBItemList* dbl = items.tqfind(key);
if (!dbl)
{
dbl = new DBItemList();
items.insert(key,dbl);
}
}
}
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