summaryrefslogtreecommitdiffstats
path: root/libktorrent/kademlia/database.cpp
blob: c4b34fdd3706884e897f1f4ed956bd9972cbb2c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/***************************************************************************
 *   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);
		}
	}
}