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