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