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.substr(0,strlen("mirror://")) != string("mirror://"))
 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    if(Debug)
 129       clog << "MirrorMethod::DownloadMirrorFile(): " << endl;
 130
 131    // not that great to use pkgAcquire here, but we do not have
 132    // any other way right now
 133    string fetch = BaseUri;
 134    fetch.replace(0,strlen("mirror://"),"http://");
 135
 136    pkgAcquire Fetcher;
 137    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 138    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 139    if(res)
 140       DownloadedMirrorFile = true;
 141    Fetcher.Shutdown();
 142    return res;
 143 }
 144
 145 /* convert a the Queue->Uri back to the mirror base uri and look
 146  * at all mirrors we have for this, this is needed as queue->uri
 147  * may point to different mirrors (if TryNextMirror() was run)
 148  */
 149 void MirrorMethod::CurrentQueueUriToMirror()
 150 {
 151    // already in mirror:// style so nothing to do
 152    if(Queue->Uri.find("mirror://") == 0)
 153       return;
 154
 155    // find current mirror and select next one
 156    for (int i=0; i < AllMirrors.size(); i++)
 157    {
 158       if (Queue->Uri.find(AllMirrors[i]) == 0)
 159       {
 160          Queue->Uri.replace(0, AllMirrors[i].size(), BaseUri);
 161          return;
 162       }
 163    }
 164    _error->Error("Internal error: Failed to convert %s back to %s",
 165                  Queue->Uri, BaseUri);
 166 }
 167
 168 bool MirrorMethod::TryNextMirror()
 169 {
 170    if(Debug)
 171       cerr << "using mirror: " << Mirror << endl;
 172
 173    // find current mirror and select next one
 174    for (int i=0; i < AllMirrors.size()-1; i++)
 175    {
 176       if (Queue->Uri.find(AllMirrors[i]) == 0)
 177       {
 178          Queue->Uri.replace(0, AllMirrors[i].size(), AllMirrors[i+1]);
 179          return true;
 180       }
 181    }
 182
 183    return false;
 184 }
 185
 186 bool MirrorMethod::InitMirrors()
 187 {
 188    // if we do not have a MirrorFile, fallback
 189    if(!FileExists(MirrorFile))
 190    {
 191       // FIXME: fallback to a default mirror here instead
 192       //        and provide a config option to define that default
 193       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 194    }
 195
 196    // FIXME: make the mirror selection more clever, do not
 197    //        just use the first one!
 198    // BUT: we can not make this random, the mirror has to be
 199    //      stable accross session, because otherwise we can
 200    //      get into sync issues (got indexfiles from mirror A,
 201    //      but packages from mirror B - one might be out of date etc)
 202    ifstream in(MirrorFile.c_str());
 203    string s;
 204    while (!in.eof())
 205    {
 206       getline(in, s);
 207       if (s.size() > 0)
 208          AllMirrors.push_back(s);
 209    }
 210    Mirror = AllMirrors[0];
 211    UsedMirror = Mirror;
 212    return true;
 213 }
 214
 215 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 216 {
 217    /*
 218     - a mirror_uri_str looks like this:
 219     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 220
 221     - the matching source.list entry
 222     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 223
 224     - we actually want to go after:
 225     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 226
 227     And we need to save the BaseUri for later:
 228     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 229
 230    FIXME: what if we have two similar prefixes?
 231      mirror://people.ubuntu.com/~mvo/mirror
 232      mirror://people.ubuntu.com/~mvo/mirror2
 233    then mirror_uri_str looks like:
 234      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 235      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 236    we search sources.list and find:
 237      mirror://people.ubuntu.com/~mvo/apt/mirror
 238    in both cases! So we need to apply some domain knowledge here :( and
 239    check for /dists/ or /Release.gpg as suffixes
 240    */
 241    string name;
 242    if(Debug)
 243       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 244
 245    // read sources.list and find match
 246    vector<metaIndex *>::const_iterator I;
 247    pkgSourceList list;
 248    list.ReadMainList();
 249    for(I=list.begin(); I != list.end(); I++)
 250    {
 251       string uristr = (*I)->GetURI();
 252       if(Debug)
 253          std::cerr << "Checking: " << uristr << std::endl;
 254       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 255          continue;
 256       // find matching uri in sources.list
 257       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 258       {
 259          if(Debug)
 260             std::cerr << "found BaseURI: " << uristr << std::endl;
 261          BaseUri = uristr.substr(0,uristr.size()-1);
 262       }
 263    }
 264    // get new file
 265    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 266
 267    if(Debug)
 268    {
 269       cerr << "base-uri: " << BaseUri << endl;
 270       cerr << "mirror-file: " << name << endl;
 271    }
 272    return name;
 273 }
 274
 275 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 276 // ---------------------------------------------------------------------
 277 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 278    depth. */
 279 bool MirrorMethod::Fetch(FetchItem *Itm)
 280 {
 281    if(Debug)
 282       clog << "MirrorMethod::Fetch()" << endl;
 283
 284    // the http method uses Fetch(0) as a way to update the pipeline,
 285    // just let it do its work in this case - Fetch() with a valid
 286    // Itm will always run before the first Fetch(0)
 287    if(Itm == NULL)
 288       return HttpMethod::Fetch(Itm);
 289
 290    // if we don't have the name of the mirror file on disk yet,
 291    // calculate it now (can be derived from the uri)
 292    if(MirrorFile.empty())
 293       MirrorFile = GetMirrorFileName(Itm->Uri);
 294
 295   // download mirror file once (if we are after index files)
 296    if(Itm->IndexFile && !DownloadedMirrorFile)
 297    {
 298       Clean(_config->FindDir("Dir::State::mirrors"));
 299       DownloadMirrorFile(Itm->Uri);
 300    }
 301
 302    if(Mirror.empty()) {
 303       if(!InitMirrors()) {
 304          // no valid mirror selected, something went wrong downloading
 305          // from the master mirror site most likely and there is
 306          // no old mirror file availalbe
 307          return false;
 308       }
 309    }
 310    if(Debug)
 311       clog << "selected mirror: " << Mirror << endl;
 312
 313
 314    for (FetchItem *I = Queue; I != 0; I = I->Next)
 315    {
 316       if(I->Uri.find("mirror://") != string::npos)
 317          I->Uri.replace(0,BaseUri.size(), Mirror);
 318    }
 319
 320    // now run the real fetcher
 321    return HttpMethod::Fetch(Itm);
 322 };
 323
 324 void MirrorMethod::Fail(string Err,bool Transient)
 325 {
 326    // try the next mirror on fail
 327    if (TryNextMirror())
 328       return;
 329
 330    // all mirrors failed, so bail out
 331    string s;
 332    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 333    SetIP(s);
 334
 335    CurrentQueueUriToMirror();
 336    pkgAcqMethod::Fail(Err, Transient);
 337 }
 338
 339 void MirrorMethod::URIStart(FetchResult &Res)
 340 {
 341    CurrentQueueUriToMirror();
 342    pkgAcqMethod::URIStart(Res);
 343 }
 344
 345 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 346 {
 347    CurrentQueueUriToMirror();
 348    pkgAcqMethod::URIDone(Res, Alt);
 349 }
 350
 351
 352 int main()
 353 {
 354    setlocale(LC_ALL, "");
 355
 356    MirrorMethod Mth;
 357
 358    return Mth.Loop();
 359 }
 360
 361