diff options
Diffstat (limited to '')
-rw-r--r-- | methods/rsh.cc | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/methods/rsh.cc b/methods/rsh.cc new file mode 100644 index 0000000..09d72cb --- /dev/null +++ b/methods/rsh.cc @@ -0,0 +1,547 @@ +// -*- mode: cpp; mode: fold -*- +// Description /*{{{*/ +/* ###################################################################### + + RSH method - Transfer files via rsh compatible program + + Written by Ben Collins <bcollins@debian.org>, Copyright (c) 2000 + Licensed under the GNU General Public License v2 [no exception clauses] + + ##################################################################### */ + /*}}}*/ +// Include Files /*{{{*/ +#include <config.h> + +#include <apt-pkg/configuration.h> +#include <apt-pkg/error.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/hashes.h> +#include <apt-pkg/strutl.h> + +#include "rsh.h" +#include <errno.h> +#include <signal.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <unistd.h> + +#include <apti18n.h> + /*}}}*/ + +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 const &Host, unsigned int Port, std::string const &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 const &Host, std::string const &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 | SendURIEncoded) +{ + 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); + auto const File = DecodeSendURI(Get.Path); + 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 (not Server->Size(File.c_str(), Size) || + not Server->ModTime(File.c_str(), FailTime)) + { + //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 (not Server->Get(File.c_str(), Fd, Res.ResumePoint, Hash, Missing, Res.Size)) + { + 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(); +} |