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