apt-pkg/acquire-worker.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire-worker.cc,v 1.6 1998/10/24 04:57:58 jgg Exp $
   4 /* ######################################################################
   5
   6    Acquire Worker
   7
   8    The worker process can startup either as a Configuration prober
   9    or as a queue runner. As a configuration prober it only reads the
  10    configuration message and
  11
  12    ##################################################################### */
  13                                                                         /*}}}*/
  14 // Include Files                                                        /*{{{*/
  15 #ifdef __GNUG__
  16 #pragma implementation "apt-pkg/acquire-worker.h"
  17 #endif
  18 #include <apt-pkg/acquire-worker.h>
  19 #include <apt-pkg/acquire-item.h>
  20 #include <apt-pkg/configuration.h>
  21 #include <apt-pkg/error.h>
  22 #include <apt-pkg/fileutl.h>
  23 #include <strutl.h>
  24
  25 #include <unistd.h>
  26 #include <signal.h>
  27 #include <wait.h>
  28                                                                         /*}}}*/
  29
  30 // Worker::Worker - Constructor for Queue startup                       /*{{{*/
  31 // ---------------------------------------------------------------------
  32 /* */
  33 pkgAcquire::Worker::Worker(Queue *Q,MethodConfig *Cnf)
  34 {
  35    OwnerQ = Q;
  36    Config = Cnf;
  37    Access = Cnf->Access;
  38    CurrentItem = 0;
  39
  40    Construct();
  41 }
  42                                                                         /*}}}*/
  43 // Worker::Worker - Constructor for method config startup               /*{{{*/
  44 // ---------------------------------------------------------------------
  45 /* */
  46 pkgAcquire::Worker::Worker(MethodConfig *Cnf)
  47 {
  48    OwnerQ = 0;
  49    Config = Cnf;
  50    Access = Cnf->Access;
  51    CurrentItem = 0;
  52
  53    Construct();
  54 }
  55                                                                         /*}}}*/
  56 // Worker::Construct - Constructor helper                               /*{{{*/
  57 // ---------------------------------------------------------------------
  58 /* */
  59 void pkgAcquire::Worker::Construct()
  60 {
  61    NextQueue = 0;
  62    NextAcquire = 0;
  63    Process = -1;
  64    InFd = -1;
  65    OutFd = -1;
  66    OutReady = false;
  67    InReady = false;
  68    Debug = _config->FindB("Debug::pkgAcquire::Worker",false);
  69 }
  70                                                                         /*}}}*/
  71 // Worker::~Worker - Destructor                                         /*{{{*/
  72 // ---------------------------------------------------------------------
  73 /* */
  74 pkgAcquire::Worker::~Worker()
  75 {
  76    close(InFd);
  77    close(OutFd);
  78
  79    if (Process > 0)
  80    {
  81       kill(Process,SIGINT);
  82       if (waitpid(Process,0,0) != Process)
  83          _error->Warning("I waited but nothing was there!");
  84    }
  85 }
  86                                                                         /*}}}*/
  87 // Worker::Start - Start the worker process                             /*{{{*/
  88 // ---------------------------------------------------------------------
  89 /* This forks the method and inits the communication channel */
  90 bool pkgAcquire::Worker::Start()
  91 {
  92    // Get the method path
  93    string Method = _config->FindDir("Dir::Bin::Methods") + Access;
  94    if (FileExists(Method) == false)
  95       return _error->Error("The method driver %s could not be found.",Method.c_str());
  96
  97    if (Debug == true)
  98       clog << "Starting method '" << Method << '\'' << endl;
  99
 100    // Create the pipes
 101    int Pipes[4] = {-1,-1,-1,-1};
 102    if (pipe(Pipes) != 0 || pipe(Pipes+2) != 0)
 103    {
 104       _error->Errno("pipe","Failed to create IPC pipe to subprocess");
 105       for (int I = 0; I != 4; I++)
 106          close(Pipes[I]);
 107       return false;
 108    }
 109
 110    // Fork off the process
 111    Process = fork();
 112    if (Process < 0)
 113    {
 114       cerr << "FATAL -> Failed to fork." << endl;
 115       exit(100);
 116    }
 117
 118    // Spawn the subprocess
 119    if (Process == 0)
 120    {
 121       // Setup the FDs
 122       dup2(Pipes[1],STDOUT_FILENO);
 123       dup2(Pipes[2],STDIN_FILENO);
 124       dup2(((filebuf *)clog.rdbuf())->fd(),STDERR_FILENO);
 125       for (int I = 0; I != 4; I++)
 126          close(Pipes[I]);
 127       SetCloseExec(STDOUT_FILENO,false);
 128       SetCloseExec(STDIN_FILENO,false);
 129       SetCloseExec(STDERR_FILENO,false);
 130
 131       const char *Args[2];
 132       Args[0] = Method.c_str();
 133       Args[1] = 0;
 134       execv(Args[0],(char **)Args);
 135       cerr << "Failed to exec method " << Args[0] << endl;
 136       exit(100);
 137    }
 138
 139    // Fix up our FDs
 140    InFd = Pipes[0];
 141    OutFd = Pipes[3];
 142    SetNonBlock(Pipes[0],true);
 143    SetNonBlock(Pipes[3],true);
 144    close(Pipes[1]);
 145    close(Pipes[2]);
 146    OutReady = false;
 147    InReady = true;
 148
 149    // Read the configuration data
 150    if (WaitFd(InFd) == false ||
 151        ReadMessages() == false)
 152       return _error->Error("Method %s did not start correctly",Method.c_str());
 153
 154    RunMessages();
 155    SendConfiguration();
 156
 157    return true;
 158 }
 159                                                                         /*}}}*/
 160 // Worker::ReadMessages - Read all pending messages into the list       /*{{{*/
 161 // ---------------------------------------------------------------------
 162 /* */
 163 bool pkgAcquire::Worker::ReadMessages()
 164 {
 165    if (::ReadMessages(InFd,MessageQueue) == false)
 166       return MethodFailure();
 167    return true;
 168 }
 169                                                                         /*}}}*/
 170 // Worker::RunMessage - Empty the message queue                         /*{{{*/
 171 // ---------------------------------------------------------------------
 172 /* This takes the messages from the message queue and runs them through
 173    the parsers in order. */
 174 bool pkgAcquire::Worker::RunMessages()
 175 {
 176    while (MessageQueue.empty() == false)
 177    {
 178       string Message = MessageQueue.front();
 179       MessageQueue.erase(MessageQueue.begin());
 180
 181       if (Debug == true)
 182          clog << " <- " << Access << ':' << QuoteString(Message,"\n") << endl;
 183
 184       // Fetch the message number
 185       char *End;
 186       int Number = strtol(Message.c_str(),&End,10);
 187       if (End == Message.c_str())
 188          return _error->Error("Invalid message from method %s: %s",Access.c_str(),Message.c_str());
 189
 190       string URI = LookupTag(Message,"URI");
 191       pkgAcquire::Queue::QItem *Itm = 0;
 192       if (URI.empty() == false)
 193          Itm = OwnerQ->FindItem(URI,this);
 194
 195       // Determine the message number and dispatch
 196       switch (Number)
 197       {
 198          // 100 Capabilities
 199          case 100:
 200          if (Capabilities(Message) == false)
 201             return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
 202          break;
 203
 204          // 101 Log
 205          case 101:
 206          if (Debug == true)
 207             clog << " <- (log) " << LookupTag(Message,"Message") << endl;
 208          break;
 209
 210          // 102 Status
 211          case 102:
 212          Status = LookupTag(Message,"Message");
 213          break;
 214
 215          // 200 URI Start
 216          case 200:
 217          {
 218             if (Itm == 0)
 219             {
 220                _error->Warning("Method gave invalid 200 URI Start message");
 221                break;
 222             }
 223             CurrentItem = Itm;
 224             CurrentSize = 0;
 225             TotalSize = atoi(LookupTag(Message,"Size","0").c_str());
 226
 227             break;
 228          }
 229
 230          // 201 URI Done
 231          case 201:
 232          {
 233             if (Itm == 0)
 234             {
 235                _error->Warning("Method gave invalid 400 URI Failure message");
 236                break;
 237             }
 238
 239             Itm->Owner->Done(Message,atoi(LookupTag(Message,"Size","0").c_str()),
 240                                           LookupTag(Message,"MD5-Hash"));
 241             OwnerQ->ItemDone(Itm);
 242             break;
 243          }
 244
 245          // 400 URI Failure
 246          case 400:
 247          {
 248             if (Itm == 0)
 249             {
 250                _error->Warning("Method gave invalid 400 URI Failure message");
 251                break;
 252             }
 253
 254             Itm->Owner->Failed(Message);
 255             OwnerQ->ItemDone(Itm);
 256             break;
 257          }
 258
 259          // 401 General Failure
 260          case 401:
 261          _error->Error("Method %s General failure: %s",LookupTag(Message,"Message").c_str());
 262          break;
 263       }
 264    }
 265    return true;
 266 }
 267                                                                         /*}}}*/
 268 // Worker::Capabilities - 100 Capabilities handler                      /*{{{*/
 269 // ---------------------------------------------------------------------
 270 /* This parses the capabilities message and dumps it into the configuration
 271    structure. */
 272 bool pkgAcquire::Worker::Capabilities(string Message)
 273 {
 274    if (Config == 0)
 275       return true;
 276
 277    Config->Version = LookupTag(Message,"Version");
 278    Config->SingleInstance = StringToBool(LookupTag(Message,"Single-Instance"),false);
 279    Config->PreScan = StringToBool(LookupTag(Message,"Pre-Scan"),false);
 280    Config->Pipeline = StringToBool(LookupTag(Message,"Pipeline"),false);
 281    Config->SendConfig = StringToBool(LookupTag(Message,"Send-Config"),false);
 282
 283    // Some debug text
 284    if (Debug == true)
 285    {
 286       clog << "Configured access method " << Config->Access << endl;
 287       clog << "Version:" << Config->Version << " SingleInstance:" <<
 288          Config->SingleInstance << " PreScan: " << Config->PreScan <<
 289          " Pipeline:" << Config->Pipeline << " SendConfig:" <<
 290          Config->SendConfig << endl;
 291    }
 292
 293    return true;
 294 }
 295                                                                         /*}}}*/
 296 // Worker::SendConfiguration - Send the config to the method            /*{{{*/
 297 // ---------------------------------------------------------------------
 298 /* */
 299 bool pkgAcquire::Worker::SendConfiguration()
 300 {
 301    if (Config->SendConfig == false)
 302       return true;
 303
 304    if (OutFd == -1)
 305       return false;
 306
 307    string Message = "601 Configuration\n";
 308    Message.reserve(2000);
 309
 310    /* Write out all of the configuration directives by walking the
 311       configuration tree */
 312    const Configuration::Item *Top = _config->Tree(0);
 313    for (; Top != 0;)
 314    {
 315       if (Top->Value.empty() == false)
 316       {
 317          string Line = "Config-Item: " + Top->FullTag() + "=";
 318          Line += QuoteString(Top->Value,"\n") + '\n';
 319          Message += Line;
 320       }
 321
 322       if (Top->Child != 0)
 323       {
 324          Top = Top->Child;
 325          continue;
 326       }
 327
 328       while (Top != 0 && Top->Next == 0)
 329          Top = Top->Parent;
 330       if (Top != 0)
 331          Top = Top->Next;
 332    }
 333    Message += '\n';
 334
 335    if (Debug == true)
 336       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 337    OutQueue += Message;
 338    OutReady = true;
 339
 340    return true;
 341 }
 342                                                                         /*}}}*/
 343 // Worker::QueueItem - Add an item to the outbound queue                /*{{{*/
 344 // ---------------------------------------------------------------------
 345 /* Send a URI Acquire message to the method */
 346 bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
 347 {
 348    if (OutFd == -1)
 349       return false;
 350
 351    string Message = "600 URI Acquire\n";
 352    Message.reserve(300);
 353    Message += "URI: " + Item->URI;
 354    Message += "\nFilename: " + Item->Owner->DestFile;
 355    Message += Item->Owner->Custom600Headers();
 356    Message += "\n\n";
 357
 358    if (Debug == true)
 359       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 360    OutQueue += Message;
 361    OutReady = true;
 362
 363    return true;
 364 }
 365                                                                         /*}}}*/
 366 // Worker::OutFdRead - Out bound FD is ready                            /*{{{*/
 367 // ---------------------------------------------------------------------
 368 /* */
 369 bool pkgAcquire::Worker::OutFdReady()
 370 {
 371    int Res = write(OutFd,OutQueue.begin(),OutQueue.length());
 372    if (Res <= 0)
 373       return MethodFailure();
 374
 375    // Hmm.. this should never happen.
 376    if (Res < 0)
 377       return true;
 378
 379    OutQueue.erase(0,Res);
 380    if (OutQueue.empty() == true)
 381       OutReady = false;
 382
 383    return true;
 384 }
 385                                                                         /*}}}*/
 386 // Worker::InFdRead - In bound FD is ready                              /*{{{*/
 387 // ---------------------------------------------------------------------
 388 /* */
 389 bool pkgAcquire::Worker::InFdReady()
 390 {
 391    if (ReadMessages() == false)
 392       return false;
 393    RunMessages();
 394    return true;
 395 }
 396                                                                         /*}}}*/
 397 // Worker::MethodFailure - Called when the method fails                 /*{{{*/
 398 // ---------------------------------------------------------------------
 399 /* This is called when the method is belived to have failed, probably because
 400    read returned -1. */
 401 bool pkgAcquire::Worker::MethodFailure()
 402 {
 403    cerr << "Method " << Access << " has died unexpectedly!" << endl;
 404    if (waitpid(Process,0,0) != Process)
 405       _error->Warning("I waited but nothing was there!");
 406    Process = -1;
 407    close(InFd);
 408    close(OutFd);
 409    InFd = -1;
 410    OutFd = -1;
 411    OutReady = false;
 412    InReady = false;
 413    OutQueue = string();
 414    MessageQueue.erase(MessageQueue.begin(),MessageQueue.end());
 415
 416    return false;
 417 }
 418                                                                         /*}}}*/