methods/mirror.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: mirror.cc,v 1.59 2004/05/08 19:42:35 mdz Exp $
   4 /* ######################################################################
   5
   6    Mirror Acquire Method - This is the Mirror acquire method for APT.
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10 // Include Files                                                        /*{{{*/
  11 #include <config.h>
  12
  13 #include <apt-pkg/aptconfiguration.h>
  14 #include <apt-pkg/fileutl.h>
  15 #include <apt-pkg/acquire-method.h>
  16 #include <apt-pkg/acquire-item.h>
  17 #include <apt-pkg/acquire.h>
  18 #include <apt-pkg/error.h>
  19 #include <apt-pkg/sourcelist.h>
  20 #include <apt-pkg/configuration.h>
  21 #include <apt-pkg/metaindex.h>
  22 #include <apt-pkg/strutl.h>
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <algorithm>
  28 #include <iostream>
  29 #include <fstream>
  30 #include <sys/stat.h>
  31 #include <sys/utsname.h>
  32 #include <dirent.h>
  33
  34 using namespace std;
  35
  36 #include<sstream>
  37
  38 #include "mirror.h"
  39 #include "http.h"
  40 #include <apti18n.h>
  41                                                                         /*}}}*/
  42
  43 /* Done:
  44  * - works with http (only!)
  45  * - always picks the first mirror from the list
  46  * - call out to problem reporting script
  47  * - supports "deb mirror://host/path/to/mirror-list/// dist component"
  48  * - uses pkgAcqMethod::FailReason() to have a string representation
  49  *   of the failure that is also send to LP
  50  *
  51  * TODO:
  52  * - deal with running as non-root because we can't write to the lists
  53      dir then -> use the cached mirror file
  54  * - better method to download than having a pkgAcquire interface here
  55  *   and better error handling there!
  56  * - support more than http
  57  * - testing :)
  58  */
  59
  60 MirrorMethod::MirrorMethod()
  61    : HttpMethod(), DownloadedMirrorFile(false), Debug(false)
  62 {
  63 }
  64
  65 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
  66 // ---------------------------------------------------------------------
  67 /* We stash the desired pipeline depth */
  68 bool MirrorMethod::Configuration(string Message)
  69 {
  70    if (pkgAcqMethod::Configuration(Message) == false)
  71       return false;
  72    Debug = _config->FindB("Debug::Acquire::mirror",false);
  73
  74    return true;
  75 }
  76                                                                         /*}}}*/
  77
  78 // clean the mirrors dir based on ttl information
  79 bool MirrorMethod::Clean(string Dir)
  80 {
  81    vector<metaIndex *>::const_iterator I;
  82
  83    if(Debug)
  84       clog << "MirrorMethod::Clean(): " << Dir << endl;
  85
  86    if(Dir == "/")
  87       return _error->Error("will not clean: '/'");
  88
  89    // read sources.list
  90    pkgSourceList list;
  91    list.ReadMainList();
  92
  93    DIR *D = opendir(Dir.c_str());
  94    if (D == 0)
  95       return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
  96
  97    string StartDir = SafeGetCWD();
  98    if (chdir(Dir.c_str()) != 0)
  99    {
 100       closedir(D);
 101       return _error->Errno("chdir",_("Unable to change to %s"),Dir.c_str());
 102    }
 103
 104    for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
 105    {
 106       // Skip some files..
 107       if (strcmp(Dir->d_name,"lock") == 0 ||
 108           strcmp(Dir->d_name,"partial") == 0 ||
 109           strcmp(Dir->d_name,"lost+found") == 0 ||
 110           strcmp(Dir->d_name,".") == 0 ||
 111           strcmp(Dir->d_name,"..") == 0)
 112          continue;
 113
 114       // see if we have that uri
 115       for(I=list.begin(); I != list.end(); ++I)
 116       {
 117          string uri = (*I)->GetURI();
 118          if(uri.compare(0, strlen("mirror://"), "mirror://") != 0)
 119             continue;
 120          string BaseUri = uri.substr(0,uri.size()-1);
 121          if (URItoFileName(BaseUri) == Dir->d_name)
 122             break;
 123       }
 124       // nothing found, nuke it
 125       if (I == list.end())
 126          RemoveFile("mirror", Dir->d_name);
 127    }
 128
 129    closedir(D);
 130    if (chdir(StartDir.c_str()) != 0)
 131       return _error->Errno("chdir",_("Unable to change to %s"),StartDir.c_str());
 132    return true;
 133 }
 134
 135
 136 bool MirrorMethod::DownloadMirrorFile(string /*mirror_uri_str*/)
 137 {
 138    // not that great to use pkgAcquire here, but we do not have
 139    // any other way right now
 140    string fetch = BaseUri;
 141    fetch.replace(0,strlen("mirror://"),"http://");
 142
 143 #if 0 // no need for this, the getArchitectures() will also include the main
 144       // arch
 145    // append main architecture
 146    fetch += "?arch=" + _config->Find("Apt::Architecture");
 147 #endif
 148
 149    // append all architectures
 150    std::vector<std::string> vec = APT::Configuration::getArchitectures();
 151    for (std::vector<std::string>::const_iterator I = vec.begin();
 152         I != vec.end(); ++I)
 153       if (I == vec.begin())
 154          fetch += "?arch=" + (*I);
 155       else
 156          fetch += "&arch=" + (*I);
 157
 158    // append the dist as a query string
 159    if (Dist != "")
 160       fetch += "&dist=" + Dist;
 161
 162    if(Debug)
 163       clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
 164            << " to " << MirrorFile << endl;
 165
 166    pkgAcquire Fetcher;
 167    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 168    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 169    if(res) {
 170       DownloadedMirrorFile = true;
 171       chmod(MirrorFile.c_str(), 0644);
 172    }
 173    Fetcher.Shutdown();
 174
 175    if(Debug)
 176       clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
 177
 178    return res;
 179 }
 180
 181 // Randomizes the lines in the mirror file, this is used so that
 182 // we spread the load on the mirrors evenly
 183 bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
 184 {
 185    vector<string> content;
 186    string line;
 187
 188    if (!FileExists(mirror_file))
 189       return false;
 190
 191    // read
 192    ifstream in(mirror_file.c_str());
 193    while ( !in.eof() ) {
 194       getline(in, line);
 195       content.push_back(line);
 196    }
 197
 198    // we want the file to be random for each different machine, but also
 199    // "stable" on the same machine. this is to avoid running into out-of-sync
 200    // issues (i.e. Release/Release.gpg different on each mirror)
 201    struct utsname buf;
 202    int seed=1;
 203    if(uname(&buf) == 0) {
 204       for(int i=0,seed=1; buf.nodename[i] != 0; ++i) {
 205          seed = seed * 31 + buf.nodename[i];
 206       }
 207    }
 208    srand( seed );
 209    random_shuffle(content.begin(), content.end());
 210
 211    // write
 212    ofstream out(mirror_file.c_str());
 213    while ( !content.empty()) {
 214       line = content.back();
 215       content.pop_back();
 216       out << line << "\n";
 217    }
 218
 219    return true;
 220 }
 221
 222 /* convert a the Queue->Uri back to the mirror base uri and look
 223  * at all mirrors we have for this, this is needed as queue->uri
 224  * may point to different mirrors (if TryNextMirror() was run)
 225  */
 226 void MirrorMethod::CurrentQueueUriToMirror()
 227 {
 228    // already in mirror:// style so nothing to do
 229    if(Queue->Uri.find("mirror://") == 0)
 230       return;
 231
 232    // find current mirror and select next one
 233    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 234         mirror != AllMirrors.end(); ++mirror)
 235    {
 236       if (Queue->Uri.find(*mirror) == 0)
 237       {
 238          Queue->Uri.replace(0, mirror->length(), BaseUri);
 239          return;
 240       }
 241    }
 242    _error->Error("Internal error: Failed to convert %s back to %s",
 243                  Queue->Uri.c_str(), BaseUri.c_str());
 244 }
 245
 246 bool MirrorMethod::TryNextMirror()
 247 {
 248    // find current mirror and select next one
 249    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 250         mirror != AllMirrors.end(); ++mirror)
 251    {
 252       if (Queue->Uri.find(*mirror) != 0)
 253          continue;
 254
 255       vector<string>::const_iterator nextmirror = mirror + 1;
 256       if (nextmirror == AllMirrors.end())
 257          break;
 258       Queue->Uri.replace(0, mirror->length(), *nextmirror);
 259       if (Debug)
 260          clog << "TryNextMirror: " << Queue->Uri << endl;
 261
 262       // inform parent
 263       UsedMirror = *nextmirror;
 264       Log("Switching mirror");
 265       return true;
 266    }
 267
 268    if (Debug)
 269       clog << "TryNextMirror could not find another mirror to try" << endl;
 270
 271    return false;
 272 }
 273
 274 bool MirrorMethod::InitMirrors()
 275 {
 276    // if we do not have a MirrorFile, fallback
 277    if(!FileExists(MirrorFile))
 278    {
 279       // FIXME: fallback to a default mirror here instead
 280       //        and provide a config option to define that default
 281       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 282    }
 283
 284    if (access(MirrorFile.c_str(), R_OK) != 0)
 285    {
 286       // FIXME: fallback to a default mirror here instead
 287       //        and provide a config option to define that default
 288       return _error->Error(_("Can not read mirror file '%s'"), MirrorFile.c_str());
 289    }
 290
 291    // FIXME: make the mirror selection more clever, do not
 292    //        just use the first one!
 293    // BUT: we can not make this random, the mirror has to be
 294    //      stable across session, because otherwise we can
 295    //      get into sync issues (got indexfiles from mirror A,
 296    //      but packages from mirror B - one might be out of date etc)
 297    ifstream in(MirrorFile.c_str());
 298    string s;
 299    while (!in.eof())
 300    {
 301       getline(in, s);
 302
 303       // ignore lines that start with #
 304       if (s.find("#") == 0)
 305          continue;
 306       // ignore empty lines
 307       if (s.size() == 0)
 308          continue;
 309       // ignore non http lines
 310       if (s.compare(0, strlen("http://"), "http://") != 0)
 311          continue;
 312
 313       AllMirrors.push_back(s);
 314    }
 315    if (AllMirrors.empty()) {
 316         return _error->Error(_("No entry found in mirror file '%s'"), MirrorFile.c_str());
 317    }
 318    Mirror = AllMirrors[0];
 319    UsedMirror = Mirror;
 320    return true;
 321 }
 322
 323 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 324 {
 325    /*
 326     - a mirror_uri_str looks like this:
 327     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 328
 329     - the matching source.list entry
 330     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 331
 332     - we actually want to go after:
 333     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 334
 335     And we need to save the BaseUri for later:
 336     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 337
 338    FIXME: what if we have two similar prefixes?
 339      mirror://people.ubuntu.com/~mvo/mirror
 340      mirror://people.ubuntu.com/~mvo/mirror2
 341    then mirror_uri_str looks like:
 342      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 343      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 344    we search sources.list and find:
 345      mirror://people.ubuntu.com/~mvo/apt/mirror
 346    in both cases! So we need to apply some domain knowledge here :( and
 347    check for /dists/ or /Release.gpg as suffixes
 348    */
 349    string name;
 350    if(Debug)
 351       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 352
 353    // read sources.list and find match
 354    vector<metaIndex *>::const_iterator I;
 355    pkgSourceList list;
 356    list.ReadMainList();
 357    for(I=list.begin(); I != list.end(); ++I)
 358    {
 359       string uristr = (*I)->GetURI();
 360       if(Debug)
 361          std::cerr << "Checking: " << uristr << std::endl;
 362       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 363          continue;
 364       // find matching uri in sources.list
 365       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 366       {
 367          if(Debug)
 368             std::cerr << "found BaseURI: " << uristr << std::endl;
 369          BaseUri = uristr.substr(0,uristr.size()-1);
 370          Dist = (*I)->GetDist();
 371       }
 372    }
 373    // get new file
 374    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 375
 376    if(Debug)
 377    {
 378       cerr << "base-uri: " << BaseUri << endl;
 379       cerr << "mirror-file: " << name << endl;
 380    }
 381    return name;
 382 }
 383
 384 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 385 // ---------------------------------------------------------------------
 386 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 387    depth. */
 388 bool MirrorMethod::Fetch(FetchItem *Itm)
 389 {
 390    if(Debug)
 391       clog << "MirrorMethod::Fetch()" << endl;
 392
 393    // the http method uses Fetch(0) as a way to update the pipeline,
 394    // just let it do its work in this case - Fetch() with a valid
 395    // Itm will always run before the first Fetch(0)
 396    if(Itm == NULL)
 397       return HttpMethod::Fetch(Itm);
 398
 399    // if we don't have the name of the mirror file on disk yet,
 400    // calculate it now (can be derived from the uri)
 401    if(MirrorFile.empty())
 402       MirrorFile = GetMirrorFileName(Itm->Uri);
 403
 404   // download mirror file once (if we are after index files)
 405    if(Itm->IndexFile && !DownloadedMirrorFile)
 406    {
 407       Clean(_config->FindDir("Dir::State::mirrors"));
 408       if (DownloadMirrorFile(Itm->Uri))
 409          RandomizeMirrorFile(MirrorFile);
 410    }
 411
 412    if(AllMirrors.empty()) {
 413       if(!InitMirrors()) {
 414          // no valid mirror selected, something went wrong downloading
 415          // from the master mirror site most likely and there is
 416          // no old mirror file availalbe
 417          return false;
 418       }
 419    }
 420
 421    if(Itm->Uri.find("mirror://") != string::npos)
 422       Itm->Uri.replace(0,BaseUri.size(), Mirror);
 423
 424    if(Debug)
 425       clog << "Fetch: " << Itm->Uri << endl << endl;
 426
 427    // now run the real fetcher
 428    return HttpMethod::Fetch(Itm);
 429 }
 430
 431 void MirrorMethod::Fail(string Err,bool Transient)
 432 {
 433    // FIXME: TryNextMirror is not ideal for indexfile as we may
 434    //        run into auth issues
 435
 436    if (Debug)
 437       clog << "Failure to get " << Queue->Uri << endl;
 438
 439    // try the next mirror on fail (if its not a expected failure,
 440    // e.g. translations are ok to ignore)
 441    if (!Queue->FailIgnore && TryNextMirror())
 442       return;
 443
 444    // all mirrors failed, so bail out
 445    string s;
 446    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 447    SetIP(s);
 448
 449    CurrentQueueUriToMirror();
 450    pkgAcqMethod::Fail(Err, Transient);
 451 }
 452
 453 void MirrorMethod::URIStart(FetchResult &Res)
 454 {
 455    CurrentQueueUriToMirror();
 456    pkgAcqMethod::URIStart(Res);
 457 }
 458
 459 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 460 {
 461    CurrentQueueUriToMirror();
 462    pkgAcqMethod::URIDone(Res, Alt);
 463 }
 464
 465
 466 int main()
 467 {
 468    setlocale(LC_ALL, "");
 469
 470    MirrorMethod Mth;
 471
 472    return Mth.Loop();
 473 }
 474
 475