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,".") == 0 ||
 110           strcmp(Dir->d_name,"..") == 0)
 111          continue;
 112
 113       // see if we have that uri
 114       for(I=list.begin(); I != list.end(); ++I)
 115       {
 116          string uri = (*I)->GetURI();
 117          if(uri.compare(0, strlen("mirror://"), "mirror://") != 0)
 118             continue;
 119          string BaseUri = uri.substr(0,uri.size()-1);
 120          if (URItoFileName(BaseUri) == Dir->d_name)
 121             break;
 122       }
 123       // nothing found, nuke it
 124       if (I == list.end())
 125          unlink(Dir->d_name);
 126    }
 127
 128    closedir(D);
 129    if (chdir(StartDir.c_str()) != 0)
 130       return _error->Errno("chdir",_("Unable to change to %s"),StartDir.c_str());
 131    return true;
 132 }
 133
 134
 135 bool MirrorMethod::DownloadMirrorFile(string /*mirror_uri_str*/)
 136 {
 137    // not that great to use pkgAcquire here, but we do not have
 138    // any other way right now
 139    string fetch = BaseUri;
 140    fetch.replace(0,strlen("mirror://"),"http://");
 141
 142 #if 0 // no need for this, the getArchitectures() will also include the main
 143       // arch
 144    // append main architecture
 145    fetch += "?arch=" + _config->Find("Apt::Architecture");
 146 #endif
 147
 148    // append all architectures
 149    std::vector<std::string> vec = APT::Configuration::getArchitectures();
 150    for (std::vector<std::string>::const_iterator I = vec.begin();
 151         I != vec.end(); ++I)
 152       if (I == vec.begin())
 153          fetch += "?arch=" + (*I);
 154       else
 155          fetch += "&arch=" + (*I);
 156
 157    // append the dist as a query string
 158    if (Dist != "")
 159       fetch += "&dist=" + Dist;
 160
 161    if(Debug)
 162       clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
 163            << " to " << MirrorFile << endl;
 164
 165    pkgAcquire Fetcher;
 166    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 167    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 168    if(res) {
 169       DownloadedMirrorFile = true;
 170       chmod(MirrorFile.c_str(), 0644);
 171    }
 172    Fetcher.Shutdown();
 173
 174    if(Debug)
 175       clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
 176
 177    return res;
 178 }
 179
 180 // Randomizes the lines in the mirror file, this is used so that
 181 // we spread the load on the mirrors evenly
 182 bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
 183 {
 184    vector<string> content;
 185    string line;
 186
 187    if (!FileExists(mirror_file))
 188       return false;
 189
 190    // read
 191    ifstream in(mirror_file.c_str());
 192    while ( !in.eof() ) {
 193       getline(in, line);
 194       content.push_back(line);
 195    }
 196
 197    // we want the file to be random for each different machine, but also
 198    // "stable" on the same machine. this is to avoid running into out-of-sync
 199    // issues (i.e. Release/Release.gpg different on each mirror)
 200    struct utsname buf;
 201    int seed=1;
 202    if(uname(&buf) == 0) {
 203       for(int i=0,seed=1; buf.nodename[i] != 0; ++i) {
 204          seed = seed * 31 + buf.nodename[i];
 205       }
 206    }
 207    srand( seed );
 208    random_shuffle(content.begin(), content.end());
 209
 210    // write
 211    ofstream out(mirror_file.c_str());
 212    while ( !content.empty()) {
 213       line = content.back();
 214       content.pop_back();
 215       out << line << "\n";
 216    }
 217
 218    return true;
 219 }
 220
 221 /* convert a the Queue->Uri back to the mirror base uri and look
 222  * at all mirrors we have for this, this is needed as queue->uri
 223  * may point to different mirrors (if TryNextMirror() was run)
 224  */
 225 void MirrorMethod::CurrentQueueUriToMirror()
 226 {
 227    // already in mirror:// style so nothing to do
 228    if(Queue->Uri.find("mirror://") == 0)
 229       return;
 230
 231    // find current mirror and select next one
 232    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 233         mirror != AllMirrors.end(); ++mirror)
 234    {
 235       if (Queue->Uri.find(*mirror) == 0)
 236       {
 237          Queue->Uri.replace(0, mirror->length(), BaseUri);
 238          return;
 239       }
 240    }
 241    _error->Error("Internal error: Failed to convert %s back to %s",
 242                  Queue->Uri.c_str(), BaseUri.c_str());
 243 }
 244
 245 bool MirrorMethod::TryNextMirror()
 246 {
 247    // find current mirror and select next one
 248    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 249         mirror != AllMirrors.end(); ++mirror)
 250    {
 251       if (Queue->Uri.find(*mirror) != 0)
 252          continue;
 253
 254       vector<string>::const_iterator nextmirror = mirror + 1;
 255       if (nextmirror == AllMirrors.end())
 256          break;
 257       Queue->Uri.replace(0, mirror->length(), *nextmirror);
 258       if (Debug)
 259          clog << "TryNextMirror: " << Queue->Uri << endl;
 260
 261       // inform parent
 262       UsedMirror = *nextmirror;
 263       Log("Switching mirror");
 264       return true;
 265    }
 266
 267    if (Debug)
 268       clog << "TryNextMirror could not find another mirror to try" << endl;
 269
 270    return false;
 271 }
 272
 273 bool MirrorMethod::InitMirrors()
 274 {
 275    // if we do not have a MirrorFile, fallback
 276    if(!FileExists(MirrorFile))
 277    {
 278       // FIXME: fallback to a default mirror here instead
 279       //        and provide a config option to define that default
 280       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 281    }
 282
 283    if (access(MirrorFile.c_str(), R_OK) != 0)
 284    {
 285       // FIXME: fallback to a default mirror here instead
 286       //        and provide a config option to define that default
 287       return _error->Error(_("Can not read mirror file '%s'"), MirrorFile.c_str());
 288    }
 289
 290    // FIXME: make the mirror selection more clever, do not
 291    //        just use the first one!
 292    // BUT: we can not make this random, the mirror has to be
 293    //      stable across session, because otherwise we can
 294    //      get into sync issues (got indexfiles from mirror A,
 295    //      but packages from mirror B - one might be out of date etc)
 296    ifstream in(MirrorFile.c_str());
 297    string s;
 298    while (!in.eof())
 299    {
 300       getline(in, s);
 301
 302       // ignore lines that start with #
 303       if (s.find("#") == 0)
 304          continue;
 305       // ignore empty lines
 306       if (s.size() == 0)
 307          continue;
 308       // ignore non http lines
 309       if (s.compare(0, strlen("http://"), "http://") != 0)
 310          continue;
 311
 312       AllMirrors.push_back(s);
 313    }
 314    if (AllMirrors.empty()) {
 315         return _error->Error(_("No entry found in mirror file '%s'"), MirrorFile.c_str());
 316    }
 317    Mirror = AllMirrors[0];
 318    UsedMirror = Mirror;
 319    return true;
 320 }
 321
 322 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 323 {
 324    /*
 325     - a mirror_uri_str looks like this:
 326     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 327
 328     - the matching source.list entry
 329     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 330
 331     - we actually want to go after:
 332     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 333
 334     And we need to save the BaseUri for later:
 335     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 336
 337    FIXME: what if we have two similar prefixes?
 338      mirror://people.ubuntu.com/~mvo/mirror
 339      mirror://people.ubuntu.com/~mvo/mirror2
 340    then mirror_uri_str looks like:
 341      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 342      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 343    we search sources.list and find:
 344      mirror://people.ubuntu.com/~mvo/apt/mirror
 345    in both cases! So we need to apply some domain knowledge here :( and
 346    check for /dists/ or /Release.gpg as suffixes
 347    */
 348    string name;
 349    if(Debug)
 350       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 351
 352    // read sources.list and find match
 353    vector<metaIndex *>::const_iterator I;
 354    pkgSourceList list;
 355    list.ReadMainList();
 356    for(I=list.begin(); I != list.end(); ++I)
 357    {
 358       string uristr = (*I)->GetURI();
 359       if(Debug)
 360          std::cerr << "Checking: " << uristr << std::endl;
 361       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 362          continue;
 363       // find matching uri in sources.list
 364       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 365       {
 366          if(Debug)
 367             std::cerr << "found BaseURI: " << uristr << std::endl;
 368          BaseUri = uristr.substr(0,uristr.size()-1);
 369          Dist = (*I)->GetDist();
 370       }
 371    }
 372    // get new file
 373    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 374
 375    if(Debug)
 376    {
 377       cerr << "base-uri: " << BaseUri << endl;
 378       cerr << "mirror-file: " << name << endl;
 379    }
 380    return name;
 381 }
 382
 383 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 384 // ---------------------------------------------------------------------
 385 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 386    depth. */
 387 bool MirrorMethod::Fetch(FetchItem *Itm)
 388 {
 389    if(Debug)
 390       clog << "MirrorMethod::Fetch()" << endl;
 391
 392    // the http method uses Fetch(0) as a way to update the pipeline,
 393    // just let it do its work in this case - Fetch() with a valid
 394    // Itm will always run before the first Fetch(0)
 395    if(Itm == NULL)
 396       return HttpMethod::Fetch(Itm);
 397
 398    // if we don't have the name of the mirror file on disk yet,
 399    // calculate it now (can be derived from the uri)
 400    if(MirrorFile.empty())
 401       MirrorFile = GetMirrorFileName(Itm->Uri);
 402
 403   // download mirror file once (if we are after index files)
 404    if(Itm->IndexFile && !DownloadedMirrorFile)
 405    {
 406       Clean(_config->FindDir("Dir::State::mirrors"));
 407       if (DownloadMirrorFile(Itm->Uri))
 408          RandomizeMirrorFile(MirrorFile);
 409    }
 410
 411    if(AllMirrors.empty()) {
 412       if(!InitMirrors()) {
 413          // no valid mirror selected, something went wrong downloading
 414          // from the master mirror site most likely and there is
 415          // no old mirror file availalbe
 416          return false;
 417       }
 418    }
 419
 420    if(Itm->Uri.find("mirror://") != string::npos)
 421       Itm->Uri.replace(0,BaseUri.size(), Mirror);
 422
 423    if(Debug)
 424       clog << "Fetch: " << Itm->Uri << endl << endl;
 425
 426    // now run the real fetcher
 427    return HttpMethod::Fetch(Itm);
 428 }
 429
 430 void MirrorMethod::Fail(string Err,bool Transient)
 431 {
 432    // FIXME: TryNextMirror is not ideal for indexfile as we may
 433    //        run into auth issues
 434
 435    if (Debug)
 436       clog << "Failure to get " << Queue->Uri << endl;
 437
 438    // try the next mirror on fail (if its not a expected failure,
 439    // e.g. translations are ok to ignore)
 440    if (!Queue->FailIgnore && TryNextMirror())
 441       return;
 442
 443    // all mirrors failed, so bail out
 444    string s;
 445    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 446    SetIP(s);
 447
 448    CurrentQueueUriToMirror();
 449    pkgAcqMethod::Fail(Err, Transient);
 450 }
 451
 452 void MirrorMethod::URIStart(FetchResult &Res)
 453 {
 454    CurrentQueueUriToMirror();
 455    pkgAcqMethod::URIStart(Res);
 456 }
 457
 458 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 459 {
 460    CurrentQueueUriToMirror();
 461    pkgAcqMethod::URIDone(Res, Alt);
 462 }
 463
 464
 465 int main()
 466 {
 467    setlocale(LC_ALL, "");
 468
 469    MirrorMethod Mth;
 470
 471    return Mth.Loop();
 472 }
 473
 474