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