// -*- mode: cpp; mode: fold -*- // Description /*{{{*/ // $Id: rsh.cc,v 1.6.2.1 2004/01/16 18:58:50 mdz Exp $ /* ###################################################################### RSH method - Transfer files via rsh compatible program Written by Ben Collins , Copyright (c) 2000 Licensed under the GNU General Public License v2 [no exception clauses] ##################################################################### */ /*}}}*/ // Include Files /*{{{*/ #include #include #include #include #include #include #include "rsh.h" #include #include #include #include #include #include #include #include #include #include /*}}}*/ unsigned long TimeOut = 30; Configuration::Item const *RshOptions = 0; time_t RSHMethod::FailTime = 0; std::string RSHMethod::FailFile; int RSHMethod::FailFd = -1; // RSHConn::RSHConn - Constructor /*{{{*/ // --------------------------------------------------------------------- /* */ RSHConn::RSHConn(std::string const &pProg, URI Srv) : Len(0), WriteFd(-1), ReadFd(-1), ServerName(Srv), Prog(pProg), Process(-1) { Buffer[0] = '\0'; } /*}}}*/ // RSHConn::RSHConn - Destructor /*{{{*/ // --------------------------------------------------------------------- /* */ RSHConn::~RSHConn() { Close(); } /*}}}*/ // RSHConn::Close - Forcibly terminate the connection /*{{{*/ // --------------------------------------------------------------------- /* Often this is called when things have gone wrong to indicate that the connection is no longer usable. */ void RSHConn::Close() { if (Process == -1) return; close(WriteFd); close(ReadFd); kill(Process,SIGINT); ExecWait(Process,"",true); WriteFd = -1; ReadFd = -1; Process = -1; } /*}}}*/ // RSHConn::Open - Connect to a host /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHConn::Open() { // Use the already open connection if possible. if (Process != -1) return true; if (Connect(ServerName.Host,ServerName.Port,ServerName.User) == false) return false; return true; } /*}}}*/ // RSHConn::Connect - Fire up rsh and connect /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHConn::Connect(std::string Host, unsigned int Port, std::string User) { char *PortStr = NULL; if (Port != 0) { if (asprintf (&PortStr, "%d", Port) == -1 || PortStr == NULL) return _error->Errno("asprintf", _("Failed")); } // Create the pipes int Pipes[4] = {-1,-1,-1,-1}; if (pipe(Pipes) != 0 || pipe(Pipes+2) != 0) { _error->Errno("pipe",_("Failed to create IPC pipe to subprocess")); for (int I = 0; I != 4; I++) close(Pipes[I]); return false; } for (int I = 0; I != 4; I++) SetCloseExec(Pipes[I],true); Process = ExecFork(); // The child if (Process == 0) { const char *Args[400]; unsigned int i = 0; dup2(Pipes[1],STDOUT_FILENO); dup2(Pipes[2],STDIN_FILENO); // Probably should do // dup2(open("/dev/null",O_RDONLY),STDERR_FILENO); Args[i++] = Prog.c_str(); // Insert user-supplied command line options Configuration::Item const *Opts = RshOptions; if (Opts != 0) { Opts = Opts->Child; for (; Opts != 0; Opts = Opts->Next) { if (Opts->Value.empty() == true) continue; Args[i++] = Opts->Value.c_str(); } } if (User.empty() == false) { Args[i++] = "-l"; Args[i++] = User.c_str(); } if (PortStr != NULL) { Args[i++] = "-p"; Args[i++] = PortStr; } if (Host.empty() == false) { Args[i++] = Host.c_str(); } Args[i++] = "/bin/sh"; Args[i] = 0; execvp(Args[0],(char **)Args); exit(100); } if (PortStr != NULL) free(PortStr); ReadFd = Pipes[0]; WriteFd = Pipes[3]; SetNonBlock(Pipes[0],true); SetNonBlock(Pipes[3],true); close(Pipes[1]); close(Pipes[2]); return true; } bool RSHConn::Connect(std::string Host, std::string User) { return Connect(Host, 0, User); } /*}}}*/ // RSHConn::ReadLine - Very simple buffered read with timeout /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHConn::ReadLine(std::string &Text) { if (Process == -1 || ReadFd == -1) return false; // Suck in a line while (Len < sizeof(Buffer)) { // Scan the buffer for a new line for (unsigned int I = 0; I != Len; I++) { // Escape some special chars if (Buffer[I] == 0) Buffer[I] = '?'; // End of line? if (Buffer[I] != '\n') continue; I++; Text = std::string(Buffer,I); memmove(Buffer,Buffer+I,Len - I); Len -= I; return true; } // Wait for some data.. if (WaitFd(ReadFd,false,TimeOut) == false) { Close(); return _error->Error(_("Connection timeout")); } // Suck it back int Res = read(ReadFd,Buffer + Len,sizeof(Buffer) - Len); if (Res <= 0) { _error->Errno("read",_("Read error")); Close(); return false; } Len += Res; } return _error->Error(_("A response overflowed the buffer.")); } /*}}}*/ // RSHConn::WriteMsg - Send a message with optional remote sync. /*{{{*/ // --------------------------------------------------------------------- /* The remote sync flag appends a || echo which will insert blank line once the command completes. */ bool RSHConn::WriteMsg(std::string &Text,bool Sync,const char *Fmt,...) { va_list args; va_start(args,Fmt); // sprintf into a buffer char Tmp[1024]; vsnprintf(Tmp,sizeof(Tmp),Fmt,args); va_end(args); // concat to create the real msg std::string Msg; if (Sync == true) Msg = std::string(Tmp) + " 2> /dev/null || echo\n"; else Msg = std::string(Tmp) + " 2> /dev/null\n"; // Send it off const char *S = Msg.c_str(); unsigned long Len = strlen(S); unsigned long Start = 0; while (Len != 0) { if (WaitFd(WriteFd,true,TimeOut) == false) { Close(); return _error->Error(_("Connection timeout")); } int Res = write(WriteFd,S + Start,Len); if (Res <= 0) { _error->Errno("write",_("Write error")); Close(); return false; } Len -= Res; Start += Res; } if (Sync == true) return ReadLine(Text); return true; } /*}}}*/ // RSHConn::Size - Return the size of the file /*{{{*/ // --------------------------------------------------------------------- /* Right now for successful transfer the file size must be known in advance. */ bool RSHConn::Size(const char *Path,unsigned long long &Size) { // Query the size std::string Msg; Size = 0; if (WriteMsg(Msg,true,"find %s -follow -printf '%%s\\n'",Path) == false) return false; // FIXME: Sense if the bad reply is due to a File Not Found. char *End; Size = strtoull(Msg.c_str(),&End,10); if (End == Msg.c_str()) return _error->Error(_("File not found")); return true; } /*}}}*/ // RSHConn::ModTime - Get the modification time in UTC /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHConn::ModTime(const char *Path, time_t &Time) { Time = time(&Time); // Query the mod time std::string Msg; if (WriteMsg(Msg,true,"TZ=UTC find %s -follow -printf '%%TY%%Tm%%Td%%TH%%TM%%TS\\n'",Path) == false) return false; // Parse it return FTPMDTMStrToTime(Msg.c_str(), Time); } /*}}}*/ // RSHConn::Get - Get a file /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHConn::Get(const char *Path,FileFd &To,unsigned long long Resume, Hashes &Hash,bool &Missing, unsigned long long Size) { Missing = false; // Round to a 2048 byte block Resume = Resume - (Resume % 2048); if (To.Truncate(Resume) == false) return false; if (To.Seek(0) == false) return false; if (Resume != 0) { if (Hash.AddFD(To,Resume) == false) { _error->Errno("read",_("Problem hashing file")); return false; } } // FIXME: Detect file-not openable type errors. std::string Jnk; if (WriteMsg(Jnk,false,"dd if=%s bs=2048 skip=%u", Path, Resume / 2048) == false) return false; // Copy loop unsigned long long MyLen = Resume; unsigned char Buffer[4096]; while (MyLen < Size) { // Wait for some data.. if (WaitFd(ReadFd,false,TimeOut) == false) { Close(); return _error->Error(_("Data socket timed out")); } // Read the data.. int Res = read(ReadFd,Buffer,sizeof(Buffer)); if (Res == 0) { Close(); return _error->Error(_("Connection closed prematurely")); } if (Res < 0) { if (errno == EAGAIN) continue; break; } MyLen += Res; Hash.Add(Buffer,Res); if (To.Write(Buffer,Res) == false) { Close(); return false; } } return true; } /*}}}*/ // RSHMethod::RSHMethod - Constructor /*{{{*/ RSHMethod::RSHMethod(std::string &&pProg) : aptMethod(std::move(pProg),"1.0",SendConfig) { signal(SIGTERM,SigTerm); signal(SIGINT,SigTerm); Server = 0; FailFd = -1; } /*}}}*/ // RSHMethod::Configuration - Handle a configuration message /*{{{*/ // --------------------------------------------------------------------- bool RSHMethod::Configuration(std::string Message) { // enabling privilege dropping for this method requires configuration… // … which is otherwise lifted straight from root, so use it by default. _config->Set(std::string("Binary::") + Binary + "::APT::Sandbox::User", ""); if (aptMethod::Configuration(Message) == false) return false; std::string const timeconf = std::string("Acquire::") + Binary + "::Timeout"; TimeOut = _config->FindI(timeconf, TimeOut); std::string const optsconf = std::string("Acquire::") + Binary + "::Options"; RshOptions = _config->Tree(optsconf.c_str()); return true; } /*}}}*/ // RSHMethod::SigTerm - Clean up and timestamp the files on exit /*{{{*/ // --------------------------------------------------------------------- /* */ void RSHMethod::SigTerm(int) { if (FailFd == -1) _exit(100); // Transfer the modification times struct timeval times[2]; times[0].tv_sec = FailTime; times[1].tv_sec = FailTime; times[0].tv_usec = times[1].tv_usec = 0; utimes(FailFile.c_str(), times); close(FailFd); _exit(100); } /*}}}*/ // RSHMethod::Fetch - Fetch a URI /*{{{*/ // --------------------------------------------------------------------- /* */ bool RSHMethod::Fetch(FetchItem *Itm) { URI Get = Itm->Uri; const char *File = Get.Path.c_str(); FetchResult Res; Res.Filename = Itm->DestFile; Res.IMSHit = false; // Connect to the server if (Server == 0 || Server->Comp(Get) == false) { delete Server; Server = new RSHConn(Binary, Get); } // Could not connect is a transient error.. if (Server->Open() == false) { Server->Close(); Fail(true); return true; } // We say this mainly because the pause here is for the // ssh connection that is still going Status(_("Connecting to %s"), Get.Host.c_str()); // Get the files information unsigned long long Size; if (Server->Size(File,Size) == false || Server->ModTime(File,FailTime) == false) { //Fail(true); //_error->Error(_("File not found")); // Will be handled by Size return false; } Res.Size = Size; // See if it is an IMS hit if (Itm->LastModified == FailTime) { Res.Size = 0; Res.IMSHit = true; URIDone(Res); return true; } // See if the file exists struct stat Buf; if (stat(Itm->DestFile.c_str(),&Buf) == 0) { if (Size == (unsigned long long)Buf.st_size && FailTime == Buf.st_mtime) { Res.Size = Buf.st_size; Res.LastModified = Buf.st_mtime; Res.ResumePoint = Buf.st_size; URIDone(Res); return true; } // Resume? if (FailTime == Buf.st_mtime && Size > (unsigned long long)Buf.st_size) Res.ResumePoint = Buf.st_size; } // Open the file Hashes Hash(Itm->ExpectedHashes); { FileFd Fd(Itm->DestFile,FileFd::WriteAny); if (_error->PendingError() == true) return false; URIStart(Res); FailFile = Itm->DestFile; FailFile.c_str(); // Make sure we don't do a malloc in the signal handler FailFd = Fd.Fd(); bool Missing; if (Server->Get(File,Fd,Res.ResumePoint,Hash,Missing,Res.Size) == false) { Fd.Close(); // Timestamp struct timeval times[2]; times[0].tv_sec = FailTime; times[1].tv_sec = FailTime; times[0].tv_usec = times[1].tv_usec = 0; utimes(FailFile.c_str(), times); // If the file is missing we hard fail otherwise transient fail if (Missing == true) return false; Fail(true); return true; } Res.Size = Fd.Size(); struct timeval times[2]; times[0].tv_sec = FailTime; times[1].tv_sec = FailTime; times[0].tv_usec = times[1].tv_usec = 0; utimes(Fd.Name().c_str(), times); FailFd = -1; } Res.LastModified = FailTime; Res.TakeHashes(Hash); URIDone(Res); return true; } /*}}}*/ int main(int, const char *argv[]) { return RSHMethod(flNotDir(argv[0])).Run(); }