apt-pkg/acquire-worker.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire-worker.cc,v 1.5 1998/10/23 00:49:58 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       // Determine the message number and dispatch
 191       switch (Number)
 192       {
 193          // 100 Capabilities
 194          case 100:
 195          if (Capabilities(Message) == false)
 196             return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
 197          break;
 198
 199          // 101 Log
 200          case 101:
 201          if (Debug == true)
 202             clog << " <- (log) " << LookupTag(Message,"Message") << endl;
 203          break;
 204
 205          // 102 Status
 206          case 102:
 207          Status = LookupTag(Message,"Message");
 208          break;
 209
 210          // 200 URI Start
 211          case 200:
 212          break;
 213
 214          // 201 URI Done
 215          case 201:
 216          break;
 217
 218          // 400 URI Failure
 219          case 400:
 220          break;
 221
 222          // 401 General Failure
 223          case 401:
 224          _error->Error("Method %s General failure: %s",LookupTag(Message,"Message").c_str());
 225          break;
 226       }
 227    }
 228    return true;
 229 }
 230                                                                         /*}}}*/
 231 // Worker::Capabilities - 100 Capabilities handler                      /*{{{*/
 232 // ---------------------------------------------------------------------
 233 /* This parses the capabilities message and dumps it into the configuration
 234    structure. */
 235 bool pkgAcquire::Worker::Capabilities(string Message)
 236 {
 237    if (Config == 0)
 238       return true;
 239
 240    Config->Version = LookupTag(Message,"Version");
 241    Config->SingleInstance = StringToBool(LookupTag(Message,"Single-Instance"),false);
 242    Config->PreScan = StringToBool(LookupTag(Message,"Pre-Scan"),false);
 243    Config->Pipeline = StringToBool(LookupTag(Message,"Pipeline"),false);
 244    Config->SendConfig = StringToBool(LookupTag(Message,"Send-Config"),false);
 245
 246    // Some debug text
 247    if (Debug == true)
 248    {
 249       clog << "Configured access method " << Config->Access << endl;
 250       clog << "Version:" << Config->Version << " SingleInstance:" <<
 251          Config->SingleInstance << " PreScan: " << Config->PreScan <<
 252          " Pipeline:" << Config->Pipeline << " SendConfig:" <<
 253          Config->SendConfig << endl;
 254    }
 255
 256    return true;
 257 }
 258                                                                         /*}}}*/
 259 // Worker::SendConfiguration - Send the config to the method            /*{{{*/
 260 // ---------------------------------------------------------------------
 261 /* */
 262 bool pkgAcquire::Worker::SendConfiguration()
 263 {
 264    if (Config->SendConfig == false)
 265       return true;
 266
 267    if (OutFd == -1)
 268       return false;
 269
 270    string Message = "601 Configuration\n";
 271    Message.reserve(2000);
 272
 273    /* Write out all of the configuration directives by walking the
 274       configuration tree */
 275    const Configuration::Item *Top = _config->Tree(0);
 276    for (; Top != 0;)
 277    {
 278       if (Top->Value.empty() == false)
 279       {
 280          string Line = "Config-Item: " + Top->FullTag() + "=";
 281          Line += QuoteString(Top->Value,"\n") + '\n';
 282          Message += Line;
 283       }
 284
 285       if (Top->Child != 0)
 286       {
 287          Top = Top->Child;
 288          continue;
 289       }
 290
 291       while (Top != 0 && Top->Next == 0)
 292          Top = Top->Parent;
 293       if (Top != 0)
 294          Top = Top->Next;
 295    }
 296    Message += '\n';
 297
 298    if (Debug == true)
 299       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 300    OutQueue += Message;
 301    OutReady = true;
 302
 303    return true;
 304 }
 305                                                                         /*}}}*/
 306 // Worker::QueueItem - Add an item to the outbound queue                /*{{{*/
 307 // ---------------------------------------------------------------------
 308 /* Send a URI Acquire message to the method */
 309 bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
 310 {
 311    if (OutFd == -1)
 312       return false;
 313
 314    string Message = "600 URI Acquire\n";
 315    Message.reserve(300);
 316    Message += "URI: " + Item->URI;
 317    Message += "\nFilename: " + Item->Owner->DestFile;
 318    Message += Item->Owner->Custom600Headers();
 319    Message += "\n\n";
 320
 321    if (Debug == true)
 322       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 323    OutQueue += Message;
 324    OutReady = true;
 325
 326    return true;
 327 }
 328                                                                         /*}}}*/
 329 // Worker::OutFdRead - Out bound FD is ready                            /*{{{*/
 330 // ---------------------------------------------------------------------
 331 /* */
 332 bool pkgAcquire::Worker::OutFdReady()
 333 {
 334    int Res = write(OutFd,OutQueue.begin(),OutQueue.length());
 335    if (Res <= 0)
 336       return MethodFailure();
 337
 338    // Hmm.. this should never happen.
 339    if (Res < 0)
 340       return true;
 341
 342    OutQueue.erase(0,Res);
 343    if (OutQueue.empty() == true)
 344       OutReady = false;
 345
 346    return true;
 347 }
 348                                                                         /*}}}*/
 349 // Worker::InFdRead - In bound FD is ready                              /*{{{*/
 350 // ---------------------------------------------------------------------
 351 /* */
 352 bool pkgAcquire::Worker::InFdReady()
 353 {
 354    if (ReadMessages() == false)
 355       return false;
 356    RunMessages();
 357    return true;
 358 }
 359                                                                         /*}}}*/
 360 // Worker::MethodFailure - Called when the method fails                 /*{{{*/
 361 // ---------------------------------------------------------------------
 362 /* This is called when the method is belived to have failed, probably because
 363    read returned -1. */
 364 bool pkgAcquire::Worker::MethodFailure()
 365 {
 366    cerr << "Method " << Access << " has died unexpectedly!" << endl;
 367    if (waitpid(Process,0,0) != Process)
 368       _error->Warning("I waited but nothing was there!");
 369    Process = -1;
 370    close(InFd);
 371    close(OutFd);
 372    InFd = -1;
 373    OutFd = -1;
 374    OutReady = false;
 375    InReady = false;
 376    OutQueue = string();
 377    MessageQueue.erase(MessageQueue.begin(),MessageQueue.end());
 378
 379    return false;
 380 }
 381                                                                         /*}}}*/