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 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/metaindex.h>
  23
  24 #include <algorithm>
  25 #include <fstream>
  26 #include <iostream>
  27
  28 #include <stdarg.h>
  29 #include <sys/stat.h>
  30 #include <sys/types.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 runing 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.find("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    chdir(StartDir.c_str());
 129    closedir(D);
 130    return true;
 131 }
 132
 133
 134 bool MirrorMethod::DownloadMirrorFile(string mirror_uri_str)
 135 {
 136    // not that great to use pkgAcquire here, but we do not have
 137    // any other way right now
 138    string fetch = BaseUri;
 139    fetch.replace(0,strlen("mirror://"),"http://");
 140
 141 #if 0 // no need for this, the getArchitectures() will also include the main
 142       // arch
 143    // append main architecture
 144    fetch += "?arch=" + _config->Find("Apt::Architecture");
 145 #endif
 146
 147    // append all architectures
 148    std::vector<std::string> vec = APT::Configuration::getArchitectures();
 149    for (std::vector<std::string>::const_iterator I = vec.begin();
 150         I != vec.end(); ++I)
 151       if (I == vec.begin())
 152          fetch += "?arch" + (*I);
 153       else
 154          fetch += "&arch=" + (*I);
 155
 156    // append the dist as a query string
 157    if (Dist != "")
 158       fetch += "&dist=" + Dist;
 159
 160    if(Debug)
 161       clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
 162            << " to " << MirrorFile << endl;
 163
 164    pkgAcquire Fetcher;
 165    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 166    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 167    if(res) {
 168       DownloadedMirrorFile = true;
 169       chmod(MirrorFile.c_str(), 0644);
 170    }
 171    Fetcher.Shutdown();
 172
 173    if(Debug)
 174       clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
 175
 176    return res;
 177 }
 178
 179 // Randomizes the lines in the mirror file, this is used so that
 180 // we spread the load on the mirrors evenly
 181 bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
 182 {
 183    vector<string> content;
 184    string line;
 185
 186    if (!FileExists(mirror_file))
 187       return false;
 188
 189    // read
 190    ifstream in(mirror_file.c_str());
 191    while ( !in.eof() ) {
 192       getline(in, line);
 193       content.push_back(line);
 194    }
 195
 196    // we want the file to be random for each different machine, but also
 197    // "stable" on the same machine. this is to avoid running into out-of-sync
 198    // issues (i.e. Release/Release.gpg different on each mirror)
 199    struct utsname buf;
 200    int seed=1, i;
 201    if(uname(&buf) == 0) {
 202       for(i=0,seed=1; buf.nodename[i] != 0; i++) {
 203          seed = seed * 31 + buf.nodename[i];
 204       }
 205    }
 206    srand( seed );
 207    random_shuffle(content.begin(), content.end());
 208
 209    // write
 210    ofstream out(mirror_file.c_str());
 211    while ( !content.empty()) {
 212       line = content.back();
 213       content.pop_back();
 214       out << line << "\n";
 215    }
 216
 217    return true;
 218 }
 219
 220 /* convert a the Queue->Uri back to the mirror base uri and look
 221  * at all mirrors we have for this, this is needed as queue->uri
 222  * may point to different mirrors (if TryNextMirror() was run)
 223  */
 224 void MirrorMethod::CurrentQueueUriToMirror()
 225 {
 226    // already in mirror:// style so nothing to do
 227    if(Queue->Uri.find("mirror://") == 0)
 228       return;
 229
 230    // find current mirror and select next one
 231    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 232         mirror != AllMirrors.end(); ++mirror)
 233    {
 234       if (Queue->Uri.find(*mirror) == 0)
 235       {
 236          Queue->Uri.replace(0, mirror->length(), BaseUri);
 237          return;
 238       }
 239    }
 240    _error->Error("Internal error: Failed to convert %s back to %s",
 241                  Queue->Uri.c_str(), BaseUri.c_str());
 242 }
 243
 244 bool MirrorMethod::TryNextMirror()
 245 {
 246    // find current mirror and select next one
 247    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 248         mirror != AllMirrors.end(); ++mirror)
 249    {
 250       if (Queue->Uri.find(*mirror) != 0)
 251          continue;
 252
 253       vector<string>::const_iterator nextmirror = mirror + 1;
 254       if (nextmirror == AllMirrors.end())
 255          break;
 256       Queue->Uri.replace(0, mirror->length(), *nextmirror);
 257       if (Debug)
 258          clog << "TryNextMirror: " << Queue->Uri << endl;
 259
 260       // inform parent
 261       UsedMirror = *nextmirror;
 262       Log("Switching mirror");
 263       return true;
 264    }
 265
 266    if (Debug)
 267       clog << "TryNextMirror could not find another mirror to try" << endl;
 268
 269    return false;
 270 }
 271
 272 bool MirrorMethod::InitMirrors()
 273 {
 274    // if we do not have a MirrorFile, fallback
 275    if(!FileExists(MirrorFile))
 276    {
 277       // FIXME: fallback to a default mirror here instead
 278       //        and provide a config option to define that default
 279       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 280    }
 281
 282    if (access(MirrorFile.c_str(), R_OK) != 0)
 283    {
 284       // FIXME: fallback to a default mirror here instead
 285       //        and provide a config option to define that default
 286       return _error->Error(_("Can not read mirror file '%s'"), MirrorFile.c_str());
 287    }
 288
 289    // FIXME: make the mirror selection more clever, do not
 290    //        just use the first one!
 291    // BUT: we can not make this random, the mirror has to be
 292    //      stable accross session, because otherwise we can
 293    //      get into sync issues (got indexfiles from mirror A,
 294    //      but packages from mirror B - one might be out of date etc)
 295    ifstream in(MirrorFile.c_str());
 296    string s;
 297    while (!in.eof())
 298    {
 299       getline(in, s);
 300
 301       // ignore lines that start with #
 302       if (s.find("#") == 0)
 303          continue;
 304       // ignore empty lines
 305       if (s.size() == 0)
 306          continue;
 307       // ignore non http lines
 308       if (s.find("http://") != 0)
 309          continue;
 310
 311       AllMirrors.push_back(s);
 312    }
 313    Mirror = AllMirrors[0];
 314    UsedMirror = Mirror;
 315    return true;
 316 }
 317
 318 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 319 {
 320    /*
 321     - a mirror_uri_str looks like this:
 322     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 323
 324     - the matching source.list entry
 325     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 326
 327     - we actually want to go after:
 328     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 329
 330     And we need to save the BaseUri for later:
 331     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 332
 333    FIXME: what if we have two similar prefixes?
 334      mirror://people.ubuntu.com/~mvo/mirror
 335      mirror://people.ubuntu.com/~mvo/mirror2
 336    then mirror_uri_str looks like:
 337      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 338      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 339    we search sources.list and find:
 340      mirror://people.ubuntu.com/~mvo/apt/mirror
 341    in both cases! So we need to apply some domain knowledge here :( and
 342    check for /dists/ or /Release.gpg as suffixes
 343    */
 344    string name;
 345    if(Debug)
 346       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 347
 348    // read sources.list and find match
 349    vector<metaIndex *>::const_iterator I;
 350    pkgSourceList list;
 351    list.ReadMainList();
 352    for(I=list.begin(); I != list.end(); ++I)
 353    {
 354       string uristr = (*I)->GetURI();
 355       if(Debug)
 356          std::cerr << "Checking: " << uristr << std::endl;
 357       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 358          continue;
 359       // find matching uri in sources.list
 360       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 361       {
 362          if(Debug)
 363             std::cerr << "found BaseURI: " << uristr << std::endl;
 364          BaseUri = uristr.substr(0,uristr.size()-1);
 365          Dist = (*I)->GetDist();
 366       }
 367    }
 368    // get new file
 369    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 370
 371    if(Debug)
 372    {
 373       cerr << "base-uri: " << BaseUri << endl;
 374       cerr << "mirror-file: " << name << endl;
 375    }
 376    return name;
 377 }
 378
 379 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 380 // ---------------------------------------------------------------------
 381 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 382    depth. */
 383 bool MirrorMethod::Fetch(FetchItem *Itm)
 384 {
 385    if(Debug)
 386       clog << "MirrorMethod::Fetch()" << endl;
 387
 388    // the http method uses Fetch(0) as a way to update the pipeline,
 389    // just let it do its work in this case - Fetch() with a valid
 390    // Itm will always run before the first Fetch(0)
 391    if(Itm == NULL)
 392       return HttpMethod::Fetch(Itm);
 393
 394    // if we don't have the name of the mirror file on disk yet,
 395    // calculate it now (can be derived from the uri)
 396    if(MirrorFile.empty())
 397       MirrorFile = GetMirrorFileName(Itm->Uri);
 398
 399   // download mirror file once (if we are after index files)
 400    if(Itm->IndexFile && !DownloadedMirrorFile)
 401    {
 402       Clean(_config->FindDir("Dir::State::mirrors"));
 403       if (DownloadMirrorFile(Itm->Uri))
 404          RandomizeMirrorFile(MirrorFile);
 405    }
 406
 407    if(AllMirrors.empty()) {
 408       if(!InitMirrors()) {
 409          // no valid mirror selected, something went wrong downloading
 410          // from the master mirror site most likely and there is
 411          // no old mirror file availalbe
 412          return false;
 413       }
 414    }
 415
 416    if(Itm->Uri.find("mirror://") != string::npos)
 417       Itm->Uri.replace(0,BaseUri.size(), Mirror);
 418
 419    if(Debug)
 420       clog << "Fetch: " << Itm->Uri << endl << endl;
 421
 422    // now run the real fetcher
 423    return HttpMethod::Fetch(Itm);
 424 };
 425
 426 void MirrorMethod::Fail(string Err,bool Transient)
 427 {
 428    // FIXME: TryNextMirror is not ideal for indexfile as we may
 429    //        run into auth issues
 430
 431    if (Debug)
 432       clog << "Failure to get " << Queue->Uri << endl;
 433
 434    // try the next mirror on fail (if its not a expected failure,
 435    // e.g. translations are ok to ignore)
 436    if (!Queue->FailIgnore && TryNextMirror())
 437       return;
 438
 439    // all mirrors failed, so bail out
 440    string s;
 441    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 442    SetIP(s);
 443
 444    CurrentQueueUriToMirror();
 445    pkgAcqMethod::Fail(Err, Transient);
 446 }
 447
 448 void MirrorMethod::URIStart(FetchResult &Res)
 449 {
 450    CurrentQueueUriToMirror();
 451    pkgAcqMethod::URIStart(Res);
 452 }
 453
 454 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 455 {
 456    CurrentQueueUriToMirror();
 457    pkgAcqMethod::URIDone(Res, Alt);
 458 }
 459
 460
 461 int main()
 462 {
 463    setlocale(LC_ALL, "");
 464
 465    MirrorMethod Mth;
 466
 467    return Mth.Loop();
 468 }
 469
 470