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