bittorrent_helper.h 14.2 KB
Newer Older
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
/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2009 Tatsuhiro Tsujikawa
 *
 * 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
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#ifndef D_BITTORRENT_HELPER_H
#define D_BITTORRENT_HELPER_H

#include "common.h"

#include <cstring>
#include <string>
#include <vector>
#include <utility>

#include "SharedHandle.h"
#include "TorrentAttribute.h"
#include "a2netcompat.h"
#include "Peer.h"
#include "ValueBase.h"
#include "util.h"
#include "DownloadContext.h"
#include "TimeA2.h"

namespace aria2 {

class DownloadContext;
class Randomizer;
class Option;

namespace bittorrent {


extern const std::string SINGLE;

extern const std::string MULTI;

extern const std::string BITTORRENT;


void load(const std::string& torrentFile,
          const SharedHandle<DownloadContext>& ctx,
          const SharedHandle<Option>& option,
          const std::string& overrideName = "");

void load(const std::string& torrentFile,
          const SharedHandle<DownloadContext>& ctx,
          const SharedHandle<Option>& option,
          const std::vector<std::string>& uris,
          const std::string& overrideName = "");

void loadFromMemory(const unsigned char* content, size_t length,
                    const SharedHandle<DownloadContext>& ctx,
                    const SharedHandle<Option>& option,
                    const std::string& defaultName,
                    const std::string& overrideName = "");

void loadFromMemory(const unsigned char* content, size_t length,
                    const SharedHandle<DownloadContext>& ctx,
                    const SharedHandle<Option>& option,
                    const std::vector<std::string>& uris,
                    const std::string& defaultName,
                    const std::string& overrideName = "");

void loadFromMemory(const std::string& context,
                    const SharedHandle<DownloadContext>& ctx,
                    const SharedHandle<Option>& option,
                    const std::string& defaultName,
                    const std::string& overrideName = "");

void loadFromMemory(const std::string& context,
                    const SharedHandle<DownloadContext>& ctx,
                    const SharedHandle<Option>& option,
                    const std::vector<std::string>& uris,
                    const std::string& defaultName,
                    const std::string& overrideName = "");

107 108 109 110 111 112 113
void loadFromMemory(const SharedHandle<ValueBase>& torrent,
                    const SharedHandle<DownloadContext>& ctx,
                    const SharedHandle<Option>& option,
                    const std::vector<std::string>& uris,
                    const std::string& defaultName,
                    const std::string& overrideName = "");

114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386
// Parses BitTorrent Magnet URI and returns
// SharedHandle<TorrentAttribute> which includes infoHash, name and
// announceList. If parsing operation failed, an RecoverableException
// will be thrown.  infoHash and name are string and announceList is a
// list of list of announce URI.
//
// magnet:?xt=urn:btih:<info-hash>&dn=<name>&tr=<tracker-url>
// <info-hash> comes in 2 flavors: 40bytes hexadecimal ascii string,
// or 32bytes Base32 encoded string.
SharedHandle<TorrentAttribute> parseMagnet(const std::string& magnet);

// Parses BitTorrent Magnet URI and set them in ctx as a
// bittorrent::BITTORRENT attibute. If parsing operation failed, an
// RecoverableException will be thrown.
void loadMagnet
(const std::string& magnet, const SharedHandle<DownloadContext>& ctx);

// Generates Peer ID. BitTorrent specification says Peer ID is 20-byte
// length.  This function uses peerIdPrefix as a Peer ID and it is
// less than 20bytes, random bytes are generated and appened to it. If
// peerIdPrefix is larger than 20bytes, first 20bytes are used.
std::string generatePeerId(const std::string& peerIdPrefix);

// Generates Peer ID and stores it in static variable. This function
// uses generatePeerId(peerIdPrefix) to produce Peer ID.
const std::string& generateStaticPeerId(const std::string& peerIdPrefix);

// Returns Peer ID statically stored by generateStaticPeerId().  If
// Peer ID is not stored yet, this function calls
// generateStaticPeerId("aria2-")
const unsigned char* getStaticPeerId();

// Set newPeerId as a static Peer ID. newPeerId must be 20-byte
// length.
void setStaticPeerId(const std::string& newPeerId);

// Computes fast set index and stores them in fastset.
void computeFastSet
(std::vector<size_t>& fastSet, const std::string& ipaddr,
 size_t numPieces, const unsigned char* infoHash, size_t fastSetSize);

SharedHandle<TorrentAttribute> getTorrentAttrs
(const SharedHandle<DownloadContext>& dctx);

// Returns the value associated with INFO_HASH key in BITTORRENT
// attribute.
const unsigned char*
getInfoHash(const SharedHandle<DownloadContext>& downloadContext);

std::string
getInfoHashString(const SharedHandle<DownloadContext>& downloadContext);

// Returns 4bytes unsigned integer located at offset pos.  The integer
// in msg is network byte order. This function converts it into host
// byte order and returns it.
uint32_t getIntParam(const unsigned char* msg, size_t pos);

// Returns 2bytes unsigned integer located at offset pos.  The integer
// in msg is network byte order. This function converts it into host
// byte order and returns it.
uint16_t getShortIntParam(const unsigned char* msg, size_t pos);

// Put param at location pointed by dest. param is converted into
// network byte order.
void setIntParam(unsigned char* dest, uint32_t param);

// Put param at location pointed by dest. param is converted into
// network byte order.
void setShortIntParam(unsigned char* dest, uint16_t param);

// Returns message ID located at first byte:msg[0]
uint8_t getId(const unsigned char* msg);
  
void checkIndex(size_t index, size_t pieces);
void checkBegin(int32_t begin, int32_t pieceLength);
void checkLength(int32_t length);
void checkRange(int32_t begin, int32_t length, int32_t pieceLength);
void checkBitfield
(const unsigned char* bitfield, size_t bitfieldLength, size_t pieces);

// Initialize msg with 0 and set payloadLength and messageId.
void createPeerMessageString
(unsigned char* msg, size_t msgLength, size_t payloadLength, uint8_t messageId);

/**
 * Creates compact form(packed addresss + 2bytes port) and stores the
 * results in compact.  This function looks addr and if it is IPv4
 * address, it stores 6bytes in compact and if it is IPv6, it stores
 * 18bytes in compact.  So compact must be at least 18 bytes and
 * pre-allocated.  Returns the number of written bytes; for IPv4
 * address, it is 6 and for IPv6, it is 18. On failure, returns 0.
 */
int packcompact
(unsigned char* compact, const std::string& addr, uint16_t port);

/**
 * Unpack packed address and port in compact and returns address and
 * port pair.  family must be AF_INET or AF_INET6.  If family is
 * AF_INET, first 6 bytes from compact is used.  If family is
 * AF_INET6, first 18 bytes from compact is used.  On failure, returns
 * std::pair<std::string, uint16_t>().
 */
std::pair<std::string, uint16_t>
unpackcompact(const unsigned char* compact, int family);

// Throws exception if threshold >= actual
void assertPayloadLengthGreater
(size_t threshold, size_t actual, const std::string& msgName);

// Throws exception if expected != actual
void assertPayloadLengthEqual
(size_t expected, size_t actual, const std::string& msgName);

// Throws exception if expected is not equal to id from data.
void assertID
(uint8_t expected, const unsigned char* data, const std::string& msgName);

// Converts attrs into torrent data. This function does not guarantee
// the returned string is valid torrent data.
std::string metadata2Torrent
(const std::string& metadata, const SharedHandle<TorrentAttribute>& attrs);

// Constructs BitTorrent Magnet URI using attrs.
std::string torrent2Magnet(const SharedHandle<TorrentAttribute>& attrs);

// Removes announce URI in uris from attrs.  If uris contains '*', all
// announce URIs are removed.
void removeAnnounceUri
(const SharedHandle<TorrentAttribute>& attrs,
 const std::vector<std::string>& uris);

// Adds announce URI in uris to attrs. Each URI in uris creates its
// own tier.
void addAnnounceUri
(const SharedHandle<TorrentAttribute>& attrs,
 const std::vector<std::string>& uris);

// This helper function uses 2 option values: PREF_BT_TRACKER and
// PREF_BT_EXCLUDE_TRACKER. First, the value of
// PREF_BT_EXCLUDE_TRACKER is converted to std::vector<std::string>
// and call removeAnnounceUri(). Then the value of PREF_BT_TRACKER is
// converted to std::vector<std::string> and call addAnnounceUri().
void adjustAnnounceUri
(const SharedHandle<TorrentAttribute>& attrs,
 const SharedHandle<Option>& option);

template<typename OutputIterator>
void extractPeer(const ValueBase* peerData, int family, OutputIterator dest)
{
  class PeerListValueBaseVisitor:public ValueBaseVisitor {
  private:
    OutputIterator dest_;
    int family_;
  public:
    PeerListValueBaseVisitor(OutputIterator dest, int family):
      dest_(dest),
      family_(family) {}

    virtual ~PeerListValueBaseVisitor() {}

    virtual void visit(const String& peerData)
    {
      int unit = family_ == AF_INET?6:18;
      size_t length = peerData.s().size();
      if(length%unit == 0) {
        const unsigned char* base =
          reinterpret_cast<const unsigned char*>(peerData.s().data());
        const unsigned char* end = base+length;
        for(; base != end; base += unit) {
          std::pair<std::string, uint16_t> p = unpackcompact(base, family_);
          if(p.first.empty()) {
            continue;
          }
          *dest_++ = SharedHandle<Peer>(new Peer(p.first, p.second));
        }
      }
    }

    virtual void visit(const Integer& v) {}
    virtual void visit(const Bool& v) {}
    virtual void visit(const Null& v) {}

    virtual void visit(const List& peerData)
    {
      for(List::ValueType::const_iterator itr = peerData.begin(),
            eoi = peerData.end(); itr != eoi; ++itr) {
        const Dict* peerDict = downcast<Dict>(*itr);
        if(!peerDict) {
          continue;
        }
        static const std::string IP = "ip";
        static const std::string PORT = "port";
        const String* ip = downcast<String>(peerDict->get(IP));
        const Integer* port = downcast<Integer>(peerDict->get(PORT));
        if(!ip || !port || !(0 < port->i() && port->i() < 65536)) {
          continue;
        }
        *dest_ = SharedHandle<Peer>(new Peer(ip->s(), port->i()));
        ++dest_;
      }
    }

    virtual void visit(const Dict& v) {}
  };
  if(peerData) {
    PeerListValueBaseVisitor visitor(dest, family);
    peerData->accept(visitor);
  }
}

template<typename OutputIterator>
void extractPeer
(const SharedHandle<ValueBase>& peerData, int family, OutputIterator dest)
{
  return extractPeer(peerData.get(), family, dest);
}

int getCompactLength(int family);

// Writes the detailed information about torrent loaded in dctx.
template<typename Output>
void print(Output& o, const SharedHandle<DownloadContext>& dctx)
{
  SharedHandle<TorrentAttribute> torrentAttrs = getTorrentAttrs(dctx);
  o.write("*** BitTorrent File Information ***\n");
  if(!torrentAttrs->comment.empty()) {
    o.printf("Comment: %s\n", torrentAttrs->comment.c_str());
  }
  if(torrentAttrs->creationDate) {
    o.printf("Creation Date: %s\n",
             Time(torrentAttrs->creationDate).toHTTPDate().c_str());
  }
  if(!torrentAttrs->createdBy.empty()) {
    o.printf("Created By: %s\n", torrentAttrs->createdBy.c_str());
  }
  o.printf("Mode: %s\n", torrentAttrs->mode.c_str());
  o.write("Announce:\n");
  for(std::vector<std::vector<std::string> >::const_iterator tierIter =
        torrentAttrs->announceList.begin(),
        eoi = torrentAttrs->announceList.end(); tierIter != eoi; ++tierIter) {
    for(std::vector<std::string>::const_iterator i = (*tierIter).begin(),
          eoi2 = (*tierIter).end(); i != eoi2; ++i) {
      o.printf(" %s", (*i).c_str());
    }
    o.write("\n");
  }
  o.printf("Info Hash: %s\n", util::toHex(torrentAttrs->infoHash).c_str());
  o.printf("Piece Length: %sB\n",
           util::abbrevSize(dctx->getPieceLength()).c_str());
  o.printf("The Number of Pieces: %lu\n",
           static_cast<unsigned long>(dctx->getNumPieces()));
  o.printf("Total Length: %sB (%s)\n",
           util::abbrevSize(dctx->getTotalLength()).c_str(),
           util::uitos(dctx->getTotalLength(), true).c_str());
  if(!torrentAttrs->urlList.empty()) {
    o.write("URL List:\n");
    for(std::vector<std::string>::const_iterator i =
          torrentAttrs->urlList.begin(),
          eoi = torrentAttrs->urlList.end(); i != eoi; ++i) {
      o.printf(" %s\n", (*i).c_str());
    }
  }
  o.printf("Name: %s\n", torrentAttrs->name.c_str());
  o.printf("Magnet URI: %s\n", torrent2Magnet(torrentAttrs).c_str());
  util::toStream
    (dctx->getFileEntries().begin(), dctx->getFileEntries().end(), o);
}

} // namespace bittorrent

} // namespace aria2

#endif // D_BITTORRENT_HELPER_H