From 7ad2a3477f39e2eac221c53e5f94954f481eb1b4 Mon Sep 17 00:00:00 2001 From: Michael Vogt Date: Mon, 28 Apr 2014 16:43:58 +0200 Subject: Implement Popen() execv helper to avoid popen() --- apt-pkg/contrib/fileutl.cc | 55 ++++++++++++++++++++++++++++++++++++++++++++++ apt-pkg/contrib/fileutl.h | 12 ++++++++++ 2 files changed, 67 insertions(+) (limited to 'apt-pkg') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index de73a7fd8..8d15baad2 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -2057,3 +2057,58 @@ bool Rename(std::string From, std::string To) } return true; } + +bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode) +{ + int fd; + if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly) + return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only"); + + int Pipe[2] = {-1, -1}; + if(pipe(Pipe) != 0) + { + return _error->Errno("pipe", _("Failed to create subprocess IPC")); + return NULL; + } + std::set keep_fds; + keep_fds.insert(Pipe[0]); + keep_fds.insert(Pipe[1]); + Child = ExecFork(keep_fds); + if(Child < 0) + return _error->Errno("fork", "Failed to fork"); + if(Child == 0) + { + if(Mode == FileFd::ReadOnly) + { + close(Pipe[0]); + fd = Pipe[1]; + } + else if(Mode == FileFd::WriteOnly) + { + close(Pipe[1]); + fd = Pipe[0]; + } + + if(Mode == FileFd::ReadOnly) + { + dup2(fd, 1); + dup2(fd, 2); + } else if(Mode == FileFd::WriteOnly) + dup2(fd, 0); + + execv(Args[0], (char**)Args); + _exit(100); + } + if(Mode == FileFd::ReadOnly) + { + close(Pipe[1]); + fd = Pipe[0]; + } else if(Mode == FileFd::WriteOnly) + { + close(Pipe[0]); + fd = Pipe[1]; + } + Fd.OpenDescriptor(fd, Mode, FileFd::None, true); + + return true; +} diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h index cc1a98eae..b7812ac56 100644 --- a/apt-pkg/contrib/fileutl.h +++ b/apt-pkg/contrib/fileutl.h @@ -201,4 +201,16 @@ std::string flCombine(std::string Dir,std::string File); // simple c++ glob std::vector Glob(std::string const &pattern, int flags=0); +/** \brief Popen() implementation that execv() instead of using a shell + * + * \param Args the execv style command to run + * \param FileFd is a referenz to the FileFd to use for input or output + * \param Child a reference to the integer that stores the child pid + * Note that you must call ExecWait() or similar to cleanup + * \param Mode is either FileFd::ReadOnly or FileFd::WriteOnly + * \return true on success, false on failure with _error set + */ +bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode); + + #endif -- cgit v1.2.3