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