apt-pkg/acquire-worker.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire-worker.cc,v 1.9 1998/11/01 05:27:33 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    for (int I = 0; I != 4; I++)
 110       SetCloseExec(Pipes[0],true);
 111
 112    // Fork off the process
 113    Process = fork();
 114    if (Process < 0)
 115    {
 116       cerr << "FATAL -> Failed to fork." << endl;
 117       exit(100);
 118    }
 119
 120    // Spawn the subprocess
 121    if (Process == 0)
 122    {
 123       // Setup the FDs
 124       dup2(Pipes[1],STDOUT_FILENO);
 125       dup2(Pipes[2],STDIN_FILENO);
 126       dup2(((filebuf *)clog.rdbuf())->fd(),STDERR_FILENO);
 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    if (OwnerQ != 0)
 156       SendConfiguration();
 157
 158    return true;
 159 }
 160                                                                         /*}}}*/
 161 // Worker::ReadMessages - Read all pending messages into the list       /*{{{*/
 162 // ---------------------------------------------------------------------
 163 /* */
 164 bool pkgAcquire::Worker::ReadMessages()
 165 {
 166    if (::ReadMessages(InFd,MessageQueue) == false)
 167       return MethodFailure();
 168    return true;
 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       string URI = LookupTag(Message,"URI");
 192       pkgAcquire::Queue::QItem *Itm = 0;
 193       if (URI.empty() == false)
 194          Itm = OwnerQ->FindItem(URI,this);
 195
 196       // Determine the message number and dispatch
 197       switch (Number)
 198       {
 199          // 100 Capabilities
 200          case 100:
 201          if (Capabilities(Message) == false)
 202             return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
 203          break;
 204
 205          // 101 Log
 206          case 101:
 207          if (Debug == true)
 208             clog << " <- (log) " << LookupTag(Message,"Message") << endl;
 209          break;
 210
 211          // 102 Status
 212          case 102:
 213          Status = LookupTag(Message,"Message");
 214          break;
 215
 216          // 200 URI Start
 217          case 200:
 218          {
 219             if (Itm == 0)
 220             {
 221                _error->Error("Method gave invalid 200 URI Start message");
 222                break;
 223             }
 224             CurrentItem = Itm;
 225             CurrentSize = 0;
 226             TotalSize = atoi(LookupTag(Message,"Size","0").c_str());
 227
 228             break;
 229          }
 230
 231          // 201 URI Done
 232          case 201:
 233          {
 234             if (Itm == 0)
 235             {
 236                _error->Error("Method gave invalid 201 URI Done message");
 237                break;
 238             }
 239
 240             OwnerQ->ItemDone(Itm);
 241             Itm->Owner->Done(Message,atoi(LookupTag(Message,"Size","0").c_str()),
 242                                           LookupTag(Message,"MD5-Hash"));
 243             break;
 244          }
 245
 246          // 400 URI Failure
 247          case 400:
 248          {
 249             if (Itm == 0)
 250             {
 251                _error->Error("Method gave invalid 400 URI Failure message");
 252                break;
 253             }
 254
 255             OwnerQ->ItemDone(Itm);
 256             Itm->Owner->Failed(Message);
 257             break;
 258          }
 259
 260          // 401 General Failure
 261          case 401:
 262          _error->Error("Method %s General failure: %s",LookupTag(Message,"Message").c_str());
 263          break;
 264       }
 265    }
 266    return true;
 267 }
 268                                                                         /*}}}*/
 269 // Worker::Capabilities - 100 Capabilities handler                      /*{{{*/
 270 // ---------------------------------------------------------------------
 271 /* This parses the capabilities message and dumps it into the configuration
 272    structure. */
 273 bool pkgAcquire::Worker::Capabilities(string Message)
 274 {
 275    if (Config == 0)
 276       return true;
 277
 278    Config->Version = LookupTag(Message,"Version");
 279    Config->SingleInstance = StringToBool(LookupTag(Message,"Single-Instance"),false);
 280    Config->PreScan = StringToBool(LookupTag(Message,"Pre-Scan"),false);
 281    Config->Pipeline = StringToBool(LookupTag(Message,"Pipeline"),false);
 282    Config->SendConfig = StringToBool(LookupTag(Message,"Send-Config"),false);
 283
 284    // Some debug text
 285    if (Debug == true)
 286    {
 287       clog << "Configured access method " << Config->Access << endl;
 288       clog << "Version:" << Config->Version << " SingleInstance:" <<
 289          Config->SingleInstance << " PreScan: " << Config->PreScan <<
 290          " Pipeline:" << Config->Pipeline << " SendConfig:" <<
 291          Config->SendConfig << endl;
 292    }
 293
 294    return true;
 295 }
 296                                                                         /*}}}*/
 297 // Worker::SendConfiguration - Send the config to the method            /*{{{*/
 298 // ---------------------------------------------------------------------
 299 /* */
 300 bool pkgAcquire::Worker::SendConfiguration()
 301 {
 302    if (Config->SendConfig == false)
 303       return true;
 304
 305    if (OutFd == -1)
 306       return false;
 307
 308    string Message = "601 Configuration\n";
 309    Message.reserve(2000);
 310
 311    /* Write out all of the configuration directives by walking the
 312       configuration tree */
 313    const Configuration::Item *Top = _config->Tree(0);
 314    for (; Top != 0;)
 315    {
 316       if (Top->Value.empty() == false)
 317       {
 318          string Line = "Config-Item: " + Top->FullTag() + "=";
 319          Line += QuoteString(Top->Value,"\n") + '\n';
 320          Message += Line;
 321       }
 322
 323       if (Top->Child != 0)
 324       {
 325          Top = Top->Child;
 326          continue;
 327       }
 328
 329       while (Top != 0 && Top->Next == 0)
 330          Top = Top->Parent;
 331       if (Top != 0)
 332          Top = Top->Next;
 333    }
 334    Message += '\n';
 335
 336    if (Debug == true)
 337       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 338    OutQueue += Message;
 339    OutReady = true;
 340
 341    return true;
 342 }
 343                                                                         /*}}}*/
 344 // Worker::QueueItem - Add an item to the outbound queue                /*{{{*/
 345 // ---------------------------------------------------------------------
 346 /* Send a URI Acquire message to the method */
 347 bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
 348 {
 349    if (OutFd == -1)
 350       return false;
 351
 352    string Message = "600 URI Acquire\n";
 353    Message.reserve(300);
 354    Message += "URI: " + Item->URI;
 355    Message += "\nFilename: " + Item->Owner->DestFile;
 356    Message += Item->Owner->Custom600Headers();
 357    Message += "\n\n";
 358
 359    if (Debug == true)
 360       clog << " -> " << Access << ':' << QuoteString(Message,"\n") << endl;
 361    OutQueue += Message;
 362    OutReady = true;
 363
 364    return true;
 365 }
 366                                                                         /*}}}*/
 367 // Worker::OutFdRead - Out bound FD is ready                            /*{{{*/
 368 // ---------------------------------------------------------------------
 369 /* */
 370 bool pkgAcquire::Worker::OutFdReady()
 371 {
 372    int Res = write(OutFd,OutQueue.begin(),OutQueue.length());
 373    if (Res <= 0)
 374       return MethodFailure();
 375
 376    // Hmm.. this should never happen.
 377    if (Res < 0)
 378       return true;
 379
 380    OutQueue.erase(0,Res);
 381    if (OutQueue.empty() == true)
 382       OutReady = false;
 383
 384    return true;
 385 }
 386                                                                         /*}}}*/
 387 // Worker::InFdRead - In bound FD is ready                              /*{{{*/
 388 // ---------------------------------------------------------------------
 389 /* */
 390 bool pkgAcquire::Worker::InFdReady()
 391 {
 392    if (ReadMessages() == false)
 393       return false;
 394    RunMessages();
 395    return true;
 396 }
 397                                                                         /*}}}*/
 398 // Worker::MethodFailure - Called when the method fails                 /*{{{*/
 399 // ---------------------------------------------------------------------
 400 /* This is called when the method is belived to have failed, probably because
 401    read returned -1. */
 402 bool pkgAcquire::Worker::MethodFailure()
 403 {
 404    cerr << "Method " << Access << " has died unexpectedly!" << endl;
 405    if (waitpid(Process,0,0) != Process)
 406       _error->Warning("I waited but nothing was there!");
 407    Process = -1;
 408    close(InFd);
 409    close(OutFd);
 410    InFd = -1;
 411    OutFd = -1;
 412    OutReady = false;
 413    InReady = false;
 414    OutQueue = string();
 415    MessageQueue.erase(MessageQueue.begin(),MessageQueue.end());
 416
 417    return false;
 418 }
 419                                                                         /*}}}*/