methods/rsh.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: rsh.cc,v 1.6.2.1 2004/01/16 18:58:50 mdz Exp $
   4 /* ######################################################################
   5
   6    RSH method - Transfer files via rsh compatible program
   7
   8    Written by Ben Collins <bcollins@debian.org>, Copyright (c) 2000
   9    Licensed under the GNU General Public License v2 [no exception clauses]
  10
  11    ##################################################################### */
  12                                                                         /*}}}*/
  13 // Include Files                                                        /*{{{*/
  14 #include <config.h>
  15
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/fileutl.h>
  18 #include <apt-pkg/hashes.h>
  19 #include <apt-pkg/configuration.h>
  20 #include <apt-pkg/acquire-method.h>
  21 #include <apt-pkg/strutl.h>
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26 #include <sys/time.h>
  27 #include <unistd.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include <stdarg.h>
  32 #include "rsh.h"
  33
  34 #include <apti18n.h>
  35                                                                         /*}}}*/
  36
  37 const char *Prog;
  38 unsigned long TimeOut = 120;
  39 Configuration::Item const *RshOptions = 0;
  40 time_t RSHMethod::FailTime = 0;
  41 std::string RSHMethod::FailFile;
  42 int RSHMethod::FailFd = -1;
  43
  44 // RSHConn::RSHConn - Constructor                                       /*{{{*/
  45 // ---------------------------------------------------------------------
  46 /* */
  47 RSHConn::RSHConn(URI Srv) : Len(0), WriteFd(-1), ReadFd(-1),
  48                             ServerName(Srv), Process(-1) {
  49    Buffer[0] = '\0';
  50 }
  51                                                                         /*}}}*/
  52 // RSHConn::RSHConn - Destructor                                        /*{{{*/
  53 // ---------------------------------------------------------------------
  54 /* */
  55 RSHConn::~RSHConn()
  56 {
  57    Close();
  58 }
  59                                                                         /*}}}*/
  60 // RSHConn::Close - Forcibly terminate the connection                   /*{{{*/
  61 // ---------------------------------------------------------------------
  62 /* Often this is called when things have gone wrong to indicate that the
  63    connection is no longer usable. */
  64 void RSHConn::Close()
  65 {
  66    if (Process == -1)
  67       return;
  68
  69    close(WriteFd);
  70    close(ReadFd);
  71    kill(Process,SIGINT);
  72    ExecWait(Process,"",true);
  73    WriteFd = -1;
  74    ReadFd = -1;
  75    Process = -1;
  76 }
  77                                                                         /*}}}*/
  78 // RSHConn::Open - Connect to a host                                    /*{{{*/
  79 // ---------------------------------------------------------------------
  80 /* */
  81 bool RSHConn::Open()
  82 {
  83    // Use the already open connection if possible.
  84    if (Process != -1)
  85       return true;
  86
  87    if (Connect(ServerName.Host,ServerName.Port,ServerName.User) == false)
  88       return false;
  89
  90    return true;
  91 }
  92                                                                         /*}}}*/
  93 // RSHConn::Connect - Fire up rsh and connect                           /*{{{*/
  94 // ---------------------------------------------------------------------
  95 /* */
  96 bool RSHConn::Connect(std::string Host, unsigned int Port, std::string User)
  97 {
  98    char *PortStr = NULL;
  99    if (Port != 0)
 100    {
 101       if (asprintf (&PortStr, "%d", Port) == -1 || PortStr == NULL)
 102          return _error->Errno("asprintf", _("Failed"));
 103    }
 104
 105    // Create the pipes
 106    int Pipes[4] = {-1,-1,-1,-1};
 107    if (pipe(Pipes) != 0 || pipe(Pipes+2) != 0)
 108    {
 109       _error->Errno("pipe",_("Failed to create IPC pipe to subprocess"));
 110       for (int I = 0; I != 4; I++)
 111          close(Pipes[I]);
 112       return false;
 113    }
 114    for (int I = 0; I != 4; I++)
 115       SetCloseExec(Pipes[I],true);
 116
 117    Process = ExecFork();
 118
 119    // The child
 120    if (Process == 0)
 121    {
 122       const char *Args[400];
 123       unsigned int i = 0;
 124
 125       dup2(Pipes[1],STDOUT_FILENO);
 126       dup2(Pipes[2],STDIN_FILENO);
 127
 128       // Probably should do
 129       // dup2(open("/dev/null",O_RDONLY),STDERR_FILENO);
 130
 131       Args[i++] = Prog;
 132
 133       // Insert user-supplied command line options
 134       Configuration::Item const *Opts = RshOptions;
 135       if (Opts != 0)
 136       {
 137          Opts = Opts->Child;
 138          for (; Opts != 0; Opts = Opts->Next)
 139          {
 140             if (Opts->Value.empty() == true)
 141                continue;
 142             Args[i++] = Opts->Value.c_str();
 143          }
 144       }
 145
 146       if (User.empty() == false) {
 147          Args[i++] = "-l";
 148          Args[i++] = User.c_str();
 149       }
 150       if (PortStr != NULL) {
 151          Args[i++] = "-p";
 152          Args[i++] = PortStr;
 153       }
 154       if (Host.empty() == false) {
 155          Args[i++] = Host.c_str();
 156       }
 157       Args[i++] = "/bin/sh";
 158       Args[i] = 0;
 159       execvp(Args[0],(char **)Args);
 160       exit(100);
 161    }
 162
 163    if (PortStr != NULL)
 164       free(PortStr);
 165
 166    ReadFd = Pipes[0];
 167    WriteFd = Pipes[3];
 168    SetNonBlock(Pipes[0],true);
 169    SetNonBlock(Pipes[3],true);
 170    close(Pipes[1]);
 171    close(Pipes[2]);
 172
 173    return true;
 174 }
 175 bool RSHConn::Connect(std::string Host, std::string User)
 176 {
 177    return Connect(Host, 0, User);
 178 }
 179                                                                         /*}}}*/
 180 // RSHConn::ReadLine - Very simple buffered read with timeout           /*{{{*/
 181 // ---------------------------------------------------------------------
 182 /* */
 183 bool RSHConn::ReadLine(std::string &Text)
 184 {
 185    if (Process == -1 || ReadFd == -1)
 186       return false;
 187
 188    // Suck in a line
 189    while (Len < sizeof(Buffer))
 190    {
 191       // Scan the buffer for a new line
 192       for (unsigned int I = 0; I != Len; I++)
 193       {
 194          // Escape some special chars
 195          if (Buffer[I] == 0)
 196             Buffer[I] = '?';
 197
 198          // End of line?
 199          if (Buffer[I] != '\n')
 200             continue;
 201
 202          I++;
 203          Text = std::string(Buffer,I);
 204          memmove(Buffer,Buffer+I,Len - I);
 205          Len -= I;
 206          return true;
 207       }
 208
 209       // Wait for some data..
 210       if (WaitFd(ReadFd,false,TimeOut) == false)
 211       {
 212          Close();
 213          return _error->Error(_("Connection timeout"));
 214       }
 215
 216       // Suck it back
 217       int Res = read(ReadFd,Buffer + Len,sizeof(Buffer) - Len);
 218       if (Res <= 0)
 219       {
 220          _error->Errno("read",_("Read error"));
 221          Close();
 222          return false;
 223       }
 224       Len += Res;
 225    }
 226
 227    return _error->Error(_("A response overflowed the buffer."));
 228 }
 229                                                                         /*}}}*/
 230 // RSHConn::WriteMsg - Send a message with optional remote sync.        /*{{{*/
 231 // ---------------------------------------------------------------------
 232 /* The remote sync flag appends a || echo which will insert blank line
 233    once the command completes. */
 234 bool RSHConn::WriteMsg(std::string &Text,bool Sync,const char *Fmt,...)
 235 {
 236    va_list args;
 237    va_start(args,Fmt);
 238
 239    // sprintf into a buffer
 240    char Tmp[1024];
 241    vsnprintf(Tmp,sizeof(Tmp),Fmt,args);
 242    va_end(args);
 243
 244    // concat to create the real msg
 245    std::string Msg;
 246    if (Sync == true)
 247       Msg = std::string(Tmp) + " 2> /dev/null || echo\n";
 248    else
 249       Msg = std::string(Tmp) + " 2> /dev/null\n";
 250
 251    // Send it off
 252    const char *S = Msg.c_str();
 253    unsigned long Len = strlen(S);
 254    unsigned long Start = 0;
 255    while (Len != 0)
 256    {
 257       if (WaitFd(WriteFd,true,TimeOut) == false)
 258       {
 259
 260          Close();
 261          return _error->Error(_("Connection timeout"));
 262       }
 263
 264       int Res = write(WriteFd,S + Start,Len);
 265       if (Res <= 0)
 266       {
 267          _error->Errno("write",_("Write error"));
 268          Close();
 269          return false;
 270       }
 271
 272       Len -= Res;
 273       Start += Res;
 274    }
 275
 276    if (Sync == true)
 277       return ReadLine(Text);
 278    return true;
 279 }
 280                                                                         /*}}}*/
 281 // RSHConn::Size - Return the size of the file                          /*{{{*/
 282 // ---------------------------------------------------------------------
 283 /* Right now for successful transfer the file size must be known in
 284    advance. */
 285 bool RSHConn::Size(const char *Path,unsigned long long &Size)
 286 {
 287    // Query the size
 288         std::string Msg;
 289    Size = 0;
 290
 291    if (WriteMsg(Msg,true,"find %s -follow -printf '%%s\\n'",Path) == false)
 292       return false;
 293
 294    // FIXME: Sense if the bad reply is due to a File Not Found.
 295
 296    char *End;
 297    Size = strtoull(Msg.c_str(),&End,10);
 298    if (End == Msg.c_str())
 299       return _error->Error(_("File not found"));
 300    return true;
 301 }
 302                                                                         /*}}}*/
 303 // RSHConn::ModTime - Get the modification time in UTC                  /*{{{*/
 304 // ---------------------------------------------------------------------
 305 /* */
 306 bool RSHConn::ModTime(const char *Path, time_t &Time)
 307 {
 308    Time = time(&Time);
 309    // Query the mod time
 310    std::string Msg;
 311
 312    if (WriteMsg(Msg,true,"TZ=UTC find %s -follow -printf '%%TY%%Tm%%Td%%TH%%TM%%TS\\n'",Path) == false)
 313       return false;
 314
 315    // Parse it
 316    return FTPMDTMStrToTime(Msg.c_str(), Time);
 317 }
 318                                                                         /*}}}*/
 319 // RSHConn::Get - Get a file                                            /*{{{*/
 320 // ---------------------------------------------------------------------
 321 /* */
 322 bool RSHConn::Get(const char *Path,FileFd &To,unsigned long long Resume,
 323                   Hashes &Hash,bool &Missing, unsigned long long Size)
 324 {
 325    Missing = false;
 326
 327    // Round to a 2048 byte block
 328    Resume = Resume - (Resume % 2048);
 329
 330    if (To.Truncate(Resume) == false)
 331       return false;
 332    if (To.Seek(0) == false)
 333       return false;
 334
 335    if (Resume != 0) {
 336       if (Hash.AddFD(To,Resume) == false) {
 337          _error->Errno("read",_("Problem hashing file"));
 338          return false;
 339       }
 340    }
 341
 342    // FIXME: Detect file-not openable type errors.
 343    std::string Jnk;
 344    if (WriteMsg(Jnk,false,"dd if=%s bs=2048 skip=%u", Path, Resume / 2048) == false)
 345       return false;
 346
 347    // Copy loop
 348    unsigned long long MyLen = Resume;
 349    unsigned char Buffer[4096];
 350    while (MyLen < Size)
 351    {
 352       // Wait for some data..
 353       if (WaitFd(ReadFd,false,TimeOut) == false)
 354       {
 355          Close();
 356          return _error->Error(_("Data socket timed out"));
 357       }
 358
 359       // Read the data..
 360       int Res = read(ReadFd,Buffer,sizeof(Buffer));
 361       if (Res == 0)
 362       {
 363          Close();
 364          return _error->Error(_("Connection closed prematurely"));
 365       }
 366
 367       if (Res < 0)
 368       {
 369          if (errno == EAGAIN)
 370             continue;
 371          break;
 372       }
 373       MyLen += Res;
 374
 375       Hash.Add(Buffer,Res);
 376       if (To.Write(Buffer,Res) == false)
 377       {
 378          Close();
 379          return false;
 380       }
 381    }
 382
 383    return true;
 384 }
 385                                                                         /*}}}*/
 386
 387 // RSHMethod::RSHMethod - Constructor                                   /*{{{*/
 388 // ---------------------------------------------------------------------
 389 /* */
 390 RSHMethod::RSHMethod() : pkgAcqMethod("1.0",SendConfig)
 391 {
 392    signal(SIGTERM,SigTerm);
 393    signal(SIGINT,SigTerm);
 394    Server = 0;
 395    FailFd = -1;
 396 }
 397                                                                         /*}}}*/
 398 // RSHMethod::Configuration - Handle a configuration message            /*{{{*/
 399 // ---------------------------------------------------------------------
 400 bool RSHMethod::Configuration(std::string Message)
 401 {
 402    char ProgStr[100];
 403
 404    if (pkgAcqMethod::Configuration(Message) == false)
 405       return false;
 406
 407    snprintf(ProgStr, sizeof ProgStr, "Acquire::%s::Timeout", Prog);
 408    TimeOut = _config->FindI(ProgStr,TimeOut);
 409    snprintf(ProgStr, sizeof ProgStr, "Acquire::%s::Options", Prog);
 410    RshOptions = _config->Tree(ProgStr);
 411
 412    return true;
 413 }
 414                                                                         /*}}}*/
 415 // RSHMethod::SigTerm - Clean up and timestamp the files on exit        /*{{{*/
 416 // ---------------------------------------------------------------------
 417 /* */
 418 void RSHMethod::SigTerm(int)
 419 {
 420    if (FailFd == -1)
 421       _exit(100);
 422
 423    // Transfer the modification times
 424    struct timeval times[2];
 425    times[0].tv_sec = FailTime;
 426    times[1].tv_sec = FailTime;
 427    times[0].tv_usec = times[1].tv_usec = 0;
 428    utimes(FailFile.c_str(), times);
 429    close(FailFd);
 430
 431    _exit(100);
 432 }
 433                                                                         /*}}}*/
 434 // RSHMethod::Fetch - Fetch a URI                                       /*{{{*/
 435 // ---------------------------------------------------------------------
 436 /* */
 437 bool RSHMethod::Fetch(FetchItem *Itm)
 438 {
 439    URI Get = Itm->Uri;
 440    const char *File = Get.Path.c_str();
 441    FetchResult Res;
 442    Res.Filename = Itm->DestFile;
 443    Res.IMSHit = false;
 444
 445    // Connect to the server
 446    if (Server == 0 || Server->Comp(Get) == false) {
 447       delete Server;
 448       Server = new RSHConn(Get);
 449    }
 450
 451    // Could not connect is a transient error..
 452    if (Server->Open() == false) {
 453       Server->Close();
 454       Fail(true);
 455       return true;
 456    }
 457
 458    // We say this mainly because the pause here is for the
 459    // ssh connection that is still going
 460    Status(_("Connecting to %s"), Get.Host.c_str());
 461
 462    // Get the files information
 463    unsigned long long Size;
 464    if (Server->Size(File,Size) == false ||
 465        Server->ModTime(File,FailTime) == false)
 466    {
 467       //Fail(true);
 468       //_error->Error(_("File not found")); // Will be handled by Size
 469       return false;
 470    }
 471    Res.Size = Size;
 472
 473    // See if it is an IMS hit
 474    if (Itm->LastModified == FailTime) {
 475       Res.Size = 0;
 476       Res.IMSHit = true;
 477       URIDone(Res);
 478       return true;
 479    }
 480
 481    // See if the file exists
 482    struct stat Buf;
 483    if (stat(Itm->DestFile.c_str(),&Buf) == 0) {
 484       if (Size == (unsigned long long)Buf.st_size && FailTime == Buf.st_mtime) {
 485          Res.Size = Buf.st_size;
 486          Res.LastModified = Buf.st_mtime;
 487          Res.ResumePoint = Buf.st_size;
 488          URIDone(Res);
 489          return true;
 490       }
 491
 492       // Resume?
 493       if (FailTime == Buf.st_mtime && Size > (unsigned long long)Buf.st_size)
 494          Res.ResumePoint = Buf.st_size;
 495    }
 496
 497    // Open the file
 498    Hashes Hash(Itm->ExpectedHashes);
 499    {
 500       FileFd Fd(Itm->DestFile,FileFd::WriteAny);
 501       if (_error->PendingError() == true)
 502          return false;
 503
 504       URIStart(Res);
 505
 506       FailFile = Itm->DestFile;
 507       FailFile.c_str();   // Make sure we don't do a malloc in the signal handler
 508       FailFd = Fd.Fd();
 509
 510       bool Missing;
 511       if (Server->Get(File,Fd,Res.ResumePoint,Hash,Missing,Res.Size) == false)
 512       {
 513          Fd.Close();
 514
 515          // Timestamp
 516          struct timeval times[2];
 517          times[0].tv_sec = FailTime;
 518          times[1].tv_sec = FailTime;
 519          times[0].tv_usec = times[1].tv_usec = 0;
 520          utimes(FailFile.c_str(), times);
 521
 522          // If the file is missing we hard fail otherwise transient fail
 523          if (Missing == true)
 524             return false;
 525          Fail(true);
 526          return true;
 527       }
 528
 529       Res.Size = Fd.Size();
 530       struct timeval times[2];
 531       times[0].tv_sec = FailTime;
 532       times[1].tv_sec = FailTime;
 533       times[0].tv_usec = times[1].tv_usec = 0;
 534       utimes(Fd.Name().c_str(), times);
 535       FailFd = -1;
 536    }
 537
 538    Res.LastModified = FailTime;
 539    Res.TakeHashes(Hash);
 540
 541    URIDone(Res);
 542
 543    return true;
 544 }
 545                                                                         /*}}}*/
 546
 547 int main(int, const char *argv[])
 548 {
 549    setlocale(LC_ALL, "");
 550
 551    RSHMethod Mth;
 552    Prog = strrchr(argv[0],'/');
 553    Prog++;
 554    return Mth.Run();
 555 }