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