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