apt-pkg/acquire-worker.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire-worker.cc,v 1.4 1998/10/22 04:56:40 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
 171 // Worker::RunMessage - Empty the message queue                         /*{{{*/
 172 // ---------------------------------------------------------------------
 173 /* This takes the messages from the message queue and runs them through
 174    the parsers in order. */
 175 bool pkgAcquire::Worker::RunMessages()
 176 {
 177    while (MessageQueue.empty() == false)
 178    {
 179       string Message = MessageQueue.front();
 180       MessageQueue.erase(MessageQueue.begin());
 181
 182       if (Debug == true)
 183          clog << " <- " << Access << ':' << QuoteString(Message,"\n") << endl;
 184
 185       // Fetch the message number
 186       char *End;
 187       int Number = strtol(Message.c_str(),&End,10);
 188       if (End == Message.c_str())
 189          return _error->Error("Invalid message from method %s: %s",Access.c_str(),Message.c_str());
 190
 191       // Determine the message number and dispatch
 192       switch (Number)
 193       {
 194          // 100 Capabilities
 195          case 100:
 196          if (Capabilities(Message) == false)
 197             return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
 198          break;
 199
 200          // 101 Log
 201          case 101:
 202          if (Debug == true)
 203             clog << " <- (log) " << LookupTag(Message,"Message") << endl;
 204          break;
 205
 206          // 102 Status
 207          case 102:
 208          Status = LookupTag(Message,"Message");
 209          break;
 210
 211          // 200 URI Start
 212          case 200:
 213          break;
 214
 215          // 201 URI Done
 216          case 201:
 217          break;
 218
 219          // 400 URI Failure
 220          case 400:
 221          break;
 222
 223          // 401 General Failure
 224          case 401:
 225          _error->Error("Method %s General failure: %s",LookupTag(Message,"Message").c_str());
 226          break;
 227       }
 228    }
 229    return true;
 230 }
 231                                                                         /*}}}*/
 232 // Worker::Capabilities - 100 Capabilities handler                      /*{{{*/
 233 // ---------------------------------------------------------------------
 234 /* This parses the capabilities message and dumps it into the configuration
 235    structure. */
 236 bool pkgAcquire::Worker::Capabilities(string Message)
 237 {
 238    if (Config == 0)
 239       return true;
 240
 241    Config->Version = LookupTag(Message,"Version");
 242    Config->SingleInstance = StringToBool(LookupTag(Message,"Single-Instance"),false);
 243    Config->PreScan = StringToBool(LookupTag(Message,"Pre-Scan"),false);
 244    Config->Pipeline = StringToBool(LookupTag(Message,"Pipeline"),false);
 245    Config->SendConfig = StringToBool(LookupTag(Message,"Send-Config"),false);
 246
 247    // Some debug text
 248    if (Debug == true)
 249    {
 250       clog << "Configured access method " << Config->Access << endl;
 251       clog << "Version:" << Config->Version << " SingleInstance:" <<
 252          Config->SingleInstance << " PreScan: " << Config->PreScan <<
 253          " Pipeline:" << Config->Pipeline << " SendConfig:" <<
 254          Config->SendConfig << endl;
 255    }
 256
 257    return true;
 258 }
 259                                                                         /*}}}*/
 260 // Worker::SendConfiguration - Send the config to the method            /*{{{*/
 261 // ---------------------------------------------------------------------
 262 /* */
 263 bool pkgAcquire::Worker::SendConfiguration()
 264 {
 265    if (Config->SendConfig == false)
 266       return true;
 267
 268    if (OutFd == -1)
 269       return false;
 270
 271    string Message = "601 Configuration\n";
 272    Message.reserve(2000);
 273
 274    /* Write out all of the configuration directives by walking the
 275       configuration tree */
 276    const Configuration::Item *Top = _config->Tree(0);
 277    for (; Top != 0;)
 278    {
 279       if (Top->Value.empty() == false)
 280       {
 281          string Line = "Config-Item: " + Top->FullTag() + "=";
 282          Line += QuoteString(Top->Value,"\n") + '\n';
 283          Message += Line;
 284       }
 285
 286       if (Top->Child != 0)
 287       {
 288          Top = Top->Child;
 289          continue;
 290       }
 291
 292       while (Top != 0 && Top->Next == 0)
 293          Top = Top->Parent;
 294       if (Top != 0)
 295          Top = Top->Next;
 296    }
 297    Message += '\n';
 298
 299    if (Debug == true)
 300       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 301    OutQueue += Message;
 302    OutReady = true;
 303
 304    return true;
 305 }
 306                                                                         /*}}}*/
 307 // Worker::QueueItem - Add an item to the outbound queue                /*{{{*/
 308 // ---------------------------------------------------------------------
 309 /* Send a URI Acquire message to the method */
 310 bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
 311 {
 312    if (OutFd == -1)
 313       return false;
 314
 315    string Message = "600 URI Acquire\n";
 316    Message.reserve(300);
 317    Message += "URI: " + Item->URI;
 318    Message += "\nFilename: " + Item->Owner->DestFile;
 319    Message += Item->Owner->Custom600Headers();
 320    Message += "\n\n";
 321
 322    if (Debug == true)
 323       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 324    OutQueue += Message;
 325    OutReady = true;
 326
 327    return true;
 328 }
 329                                                                         /*}}}*/
 330 // Worker::OutFdRead - Out bound FD is ready                            /*{{{*/
 331 // ---------------------------------------------------------------------
 332 /* */
 333 bool pkgAcquire::Worker::OutFdReady()
 334 {
 335    int Res = write(OutFd,OutQueue.begin(),OutQueue.length());
 336    if (Res <= 0)
 337       return MethodFailure();
 338
 339    // Hmm.. this should never happen.
 340    if (Res < 0)
 341       return true;
 342
 343    OutQueue.erase(0,Res);
 344    if (OutQueue.empty() == true)
 345       OutReady = false;
 346
 347    return true;
 348 }
 349                                                                         /*}}}*/
 350 // Worker::InFdRead - In bound FD is ready                              /*{{{*/
 351 // ---------------------------------------------------------------------
 352 /* */
 353 bool pkgAcquire::Worker::InFdReady()
 354 {
 355    if (ReadMessages() == false)
 356       return false;
 357    RunMessages();
 358    return true;
 359 }
 360                                                                         /*}}}*/
 361 // Worker::MethodFailure - Called when the method fails                 /*{{{*/
 362 // ---------------------------------------------------------------------
 363 /* This is called when the method is belived to have failed, probably because
 364    read returned -1. */
 365 bool pkgAcquire::Worker::MethodFailure()
 366 {
 367    cerr << "Method " << Access << " has died unexpectedly!" << endl;
 368    if (waitpid(Process,0,0) != Process)
 369       _error->Warning("I waited but nothing was there!");
 370    Process = -1;
 371    close(InFd);
 372    close(OutFd);
 373    InFd = -1;
 374    OutFd = -1;
 375    OutReady = false;
 376    InReady = false;
 377    OutQueue = string();
 378    MessageQueue.erase(MessageQueue.begin(),MessageQueue.end());
 379
 380    return false;
 381 }
 382                                                                         /*}}}*/