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/aptconfiguration.h>
  12 #include <apt-pkg/fileutl.h>
  13 #include <apt-pkg/acquire-method.h>
  14 #include <apt-pkg/acquire-item.h>
  15 #include <apt-pkg/acquire.h>
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/hashes.h>
  18 #include <apt-pkg/sourcelist.h>
  19
  20
  21 #include <algorithm>
  22 #include <fstream>
  23 #include <iostream>
  24
  25 #include <stdarg.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28 #include <sys/utsname.h>
  29 #include <dirent.h>
  30
  31 using namespace std;
  32
  33 #include<sstream>
  34
  35 #include "mirror.h"
  36 #include "http.h"
  37 #include "apti18n.h"
  38                                                                         /*}}}*/
  39
  40 /* Done:
  41  * - works with http (only!)
  42  * - always picks the first mirror from the list
  43  * - call out to problem reporting script
  44  * - supports "deb mirror://host/path/to/mirror-list/// dist component"
  45  * - uses pkgAcqMethod::FailReason() to have a string representation
  46  *   of the failure that is also send to LP
  47  *
  48  * TODO:
  49  * - deal with runing as non-root because we can't write to the lists
  50      dir then -> use the cached mirror file
  51  * - better method to download than having a pkgAcquire interface here
  52  *   and better error handling there!
  53  * - support more than http
  54  * - testing :)
  55  */
  56
  57 MirrorMethod::MirrorMethod()
  58    : HttpMethod(), DownloadedMirrorFile(false)
  59 {
  60 };
  61
  62 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
  63 // ---------------------------------------------------------------------
  64 /* We stash the desired pipeline depth */
  65 bool MirrorMethod::Configuration(string Message)
  66 {
  67    if (pkgAcqMethod::Configuration(Message) == false)
  68       return false;
  69    Debug = _config->FindB("Debug::Acquire::mirror",false);
  70
  71    return true;
  72 }
  73                                                                         /*}}}*/
  74
  75 // clean the mirrors dir based on ttl information
  76 bool MirrorMethod::Clean(string Dir)
  77 {
  78    vector<metaIndex *>::const_iterator I;
  79
  80    if(Debug)
  81       clog << "MirrorMethod::Clean(): " << Dir << endl;
  82
  83    if(Dir == "/")
  84       return _error->Error("will not clean: '/'");
  85
  86    // read sources.list
  87    pkgSourceList list;
  88    list.ReadMainList();
  89
  90    DIR *D = opendir(Dir.c_str());
  91    if (D == 0)
  92       return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
  93
  94    string StartDir = SafeGetCWD();
  95    if (chdir(Dir.c_str()) != 0)
  96    {
  97       closedir(D);
  98       return _error->Errno("chdir",_("Unable to change to %s"),Dir.c_str());
  99    }
 100
 101    for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
 102    {
 103       // Skip some files..
 104       if (strcmp(Dir->d_name,"lock") == 0 ||
 105           strcmp(Dir->d_name,"partial") == 0 ||
 106           strcmp(Dir->d_name,".") == 0 ||
 107           strcmp(Dir->d_name,"..") == 0)
 108          continue;
 109
 110       // see if we have that uri
 111       for(I=list.begin(); I != list.end(); I++)
 112       {
 113          string uri = (*I)->GetURI();
 114          if(uri.find("mirror://") != 0)
 115             continue;
 116          string BaseUri = uri.substr(0,uri.size()-1);
 117          if (URItoFileName(BaseUri) == Dir->d_name)
 118             break;
 119       }
 120       // nothing found, nuke it
 121       if (I == list.end())
 122          unlink(Dir->d_name);
 123    };
 124
 125    chdir(StartDir.c_str());
 126    closedir(D);
 127    return true;
 128 }
 129
 130
 131 bool MirrorMethod::DownloadMirrorFile(string mirror_uri_str)
 132 {
 133    // not that great to use pkgAcquire here, but we do not have
 134    // any other way right now
 135    string fetch = BaseUri;
 136    fetch.replace(0,strlen("mirror://"),"http://");
 137
 138 #if 0 // no need for this, the getArchitectures() will also include the main
 139       // arch
 140    // append main architecture
 141    fetch += "?arch=" + _config->Find("Apt::Architecture");
 142 #endif
 143
 144    // append all architectures
 145    std::vector<std::string> vec = APT::Configuration::getArchitectures();
 146    for (std::vector<std::string>::const_iterator I = vec.begin();
 147         I != vec.end(); I++)
 148       if (I == vec.begin())
 149          fetch += "?arch" + (*I);
 150       else
 151          fetch += "&arch=" + (*I);
 152
 153    // append the dist as a query string
 154    if (Dist != "")
 155       fetch += "&dist=" + Dist;
 156
 157    if(Debug)
 158       clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
 159            << " to " << MirrorFile << endl;
 160
 161    pkgAcquire Fetcher;
 162    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 163    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 164    if(res) {
 165       DownloadedMirrorFile = true;
 166       chmod(MirrorFile.c_str(), 0644);
 167    }
 168    Fetcher.Shutdown();
 169
 170    if(Debug)
 171       clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
 172
 173    return res;
 174 }
 175
 176 // Randomizes the lines in the mirror file, this is used so that
 177 // we spread the load on the mirrors evenly
 178 bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
 179 {
 180    vector<string> content;
 181    string line;
 182
 183    if (!FileExists(mirror_file))
 184       return false;
 185
 186    // read
 187    ifstream in(mirror_file.c_str());
 188    while ( !in.eof() ) {
 189       getline(in, line);
 190       content.push_back(line);
 191    }
 192
 193    // we want the file to be random for each different machine, but also
 194    // "stable" on the same machine. this is to avoid running into out-of-sync
 195    // issues (i.e. Release/Release.gpg different on each mirror)
 196    struct utsname buf;
 197    int seed=1, i;
 198    if(uname(&buf) == 0) {
 199       for(i=0,seed=1; buf.nodename[i] != 0; i++) {
 200          seed = seed * 31 + buf.nodename[i];
 201       }
 202    }
 203    srand( seed );
 204    random_shuffle(content.begin(), content.end());
 205
 206    // write
 207    ofstream out(mirror_file.c_str());
 208    while ( !content.empty()) {
 209       line = content.back();
 210       content.pop_back();
 211       out << line << "\n";
 212    }
 213
 214    return true;
 215 }
 216
 217 /* convert a the Queue->Uri back to the mirror base uri and look
 218  * at all mirrors we have for this, this is needed as queue->uri
 219  * may point to different mirrors (if TryNextMirror() was run)
 220  */
 221 void MirrorMethod::CurrentQueueUriToMirror()
 222 {
 223    // already in mirror:// style so nothing to do
 224    if(Queue->Uri.find("mirror://") == 0)
 225       return;
 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       {
 233          Queue->Uri.replace(0, mirror->length(), BaseUri);
 234          return;
 235       }
 236    }
 237    _error->Error("Internal error: Failed to convert %s back to %s",
 238                  Queue->Uri.c_str(), BaseUri.c_str());
 239 }
 240
 241 bool MirrorMethod::TryNextMirror()
 242 {
 243    // find current mirror and select next one
 244    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 245         mirror != AllMirrors.end(); ++mirror)
 246    {
 247       if (Queue->Uri.find(*mirror) != 0)
 248          continue;
 249
 250       vector<string>::const_iterator nextmirror = mirror + 1;
 251       if (nextmirror == AllMirrors.end())
 252          break;
 253       Queue->Uri.replace(0, mirror->length(), *nextmirror);
 254       if (Debug)
 255          clog << "TryNextMirror: " << Queue->Uri << endl;
 256
 257       // inform parent
 258       UsedMirror = *nextmirror;
 259       Log("Switching mirror");
 260       return true;
 261    }
 262
 263    if (Debug)
 264       clog << "TryNextMirror could not find another mirror to try" << endl;
 265
 266    return false;
 267 }
 268
 269 bool MirrorMethod::InitMirrors()
 270 {
 271    // if we do not have a MirrorFile, fallback
 272    if(!FileExists(MirrorFile))
 273    {
 274       // FIXME: fallback to a default mirror here instead
 275       //        and provide a config option to define that default
 276       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 277    }
 278
 279    if (access(MirrorFile.c_str(), R_OK) != 0)
 280    {
 281       // FIXME: fallback to a default mirror here instead
 282       //        and provide a config option to define that default
 283       return _error->Error(_("Can not read mirror file '%s'"), MirrorFile.c_str());
 284    }
 285
 286    // FIXME: make the mirror selection more clever, do not
 287    //        just use the first one!
 288    // BUT: we can not make this random, the mirror has to be
 289    //      stable accross session, because otherwise we can
 290    //      get into sync issues (got indexfiles from mirror A,
 291    //      but packages from mirror B - one might be out of date etc)
 292    ifstream in(MirrorFile.c_str());
 293    string s;
 294    while (!in.eof())
 295    {
 296       getline(in, s);
 297
 298       // ignore lines that start with #
 299       if (s.find("#") == 0)
 300          continue;
 301       // ignore empty lines
 302       if (s.size() == 0)
 303          continue;
 304       // ignore non http lines
 305       if (s.find("http://") != 0)
 306          continue;
 307
 308       AllMirrors.push_back(s);
 309    }
 310    Mirror = AllMirrors[0];
 311    UsedMirror = Mirror;
 312    return true;
 313 }
 314
 315 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 316 {
 317    /*
 318     - a mirror_uri_str looks like this:
 319     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 320
 321     - the matching source.list entry
 322     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 323
 324     - we actually want to go after:
 325     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 326
 327     And we need to save the BaseUri for later:
 328     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 329
 330    FIXME: what if we have two similar prefixes?
 331      mirror://people.ubuntu.com/~mvo/mirror
 332      mirror://people.ubuntu.com/~mvo/mirror2
 333    then mirror_uri_str looks like:
 334      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 335      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 336    we search sources.list and find:
 337      mirror://people.ubuntu.com/~mvo/apt/mirror
 338    in both cases! So we need to apply some domain knowledge here :( and
 339    check for /dists/ or /Release.gpg as suffixes
 340    */
 341    string name;
 342    if(Debug)
 343       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 344
 345    // read sources.list and find match
 346    vector<metaIndex *>::const_iterator I;
 347    pkgSourceList list;
 348    list.ReadMainList();
 349    for(I=list.begin(); I != list.end(); I++)
 350    {
 351       string uristr = (*I)->GetURI();
 352       if(Debug)
 353          std::cerr << "Checking: " << uristr << std::endl;
 354       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 355          continue;
 356       // find matching uri in sources.list
 357       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 358       {
 359          if(Debug)
 360             std::cerr << "found BaseURI: " << uristr << std::endl;
 361          BaseUri = uristr.substr(0,uristr.size()-1);
 362          Dist = (*I)->GetDist();
 363       }
 364    }
 365    // get new file
 366    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 367
 368    if(Debug)
 369    {
 370       cerr << "base-uri: " << BaseUri << endl;
 371       cerr << "mirror-file: " << name << endl;
 372    }
 373    return name;
 374 }
 375
 376 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 377 // ---------------------------------------------------------------------
 378 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 379    depth. */
 380 bool MirrorMethod::Fetch(FetchItem *Itm)
 381 {
 382    if(Debug)
 383       clog << "MirrorMethod::Fetch()" << endl;
 384
 385    // the http method uses Fetch(0) as a way to update the pipeline,
 386    // just let it do its work in this case - Fetch() with a valid
 387    // Itm will always run before the first Fetch(0)
 388    if(Itm == NULL)
 389       return HttpMethod::Fetch(Itm);
 390
 391    // if we don't have the name of the mirror file on disk yet,
 392    // calculate it now (can be derived from the uri)
 393    if(MirrorFile.empty())
 394       MirrorFile = GetMirrorFileName(Itm->Uri);
 395
 396   // download mirror file once (if we are after index files)
 397    if(Itm->IndexFile && !DownloadedMirrorFile)
 398    {
 399       Clean(_config->FindDir("Dir::State::mirrors"));
 400       if (DownloadMirrorFile(Itm->Uri))
 401          RandomizeMirrorFile(MirrorFile);
 402    }
 403
 404    if(AllMirrors.empty()) {
 405       if(!InitMirrors()) {
 406          // no valid mirror selected, something went wrong downloading
 407          // from the master mirror site most likely and there is
 408          // no old mirror file availalbe
 409          return false;
 410       }
 411    }
 412
 413    if(Itm->Uri.find("mirror://") != string::npos)
 414       Itm->Uri.replace(0,BaseUri.size(), Mirror);
 415
 416    if(Debug)
 417       clog << "Fetch: " << Itm->Uri << endl << endl;
 418
 419    // now run the real fetcher
 420    return HttpMethod::Fetch(Itm);
 421 };
 422
 423 void MirrorMethod::Fail(string Err,bool Transient)
 424 {
 425    // FIXME: TryNextMirror is not ideal for indexfile as we may
 426    //        run into auth issues
 427
 428    if (Debug)
 429       clog << "Failure to get " << Queue->Uri << endl;
 430
 431    // try the next mirror on fail (if its not a expected failure,
 432    // e.g. translations are ok to ignore)
 433    if (!Queue->FailIgnore && TryNextMirror())
 434       return;
 435
 436    // all mirrors failed, so bail out
 437    string s;
 438    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 439    SetIP(s);
 440
 441    CurrentQueueUriToMirror();
 442    pkgAcqMethod::Fail(Err, Transient);
 443 }
 444
 445 void MirrorMethod::URIStart(FetchResult &Res)
 446 {
 447    CurrentQueueUriToMirror();
 448    pkgAcqMethod::URIStart(Res);
 449 }
 450
 451 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 452 {
 453    CurrentQueueUriToMirror();
 454    pkgAcqMethod::URIDone(Res, Alt);
 455 }
 456
 457
 458 int main()
 459 {
 460    setlocale(LC_ALL, "");
 461
 462    MirrorMethod Mth;
 463
 464    return Mth.Loop();
 465 }
 466
 467