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changeset 30196:c3eeb3b0bffd

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New module 'posix_spawn-internal'.
author Bruno Haible <bruno@clisp.org>
date Sun, 28 Sep 2008 13:30:49 +0200
parents 418dfe90256c
children c9fd8077aa75
files ChangeLog lib/spawn_int.h lib/spawni.c m4/posix_spawn.m4 modules/posix_spawn-internal
diffstat 5 files changed, 500 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog	Sun Sep 28 13:26:56 2008 +0200
+++ b/ChangeLog	Sun Sep 28 13:30:49 2008 +0200
@@ -1,8 +1,14 @@
 2008-09-28  Bruno Haible  <bruno@clisp.org>
 
+	New module 'posix_spawn-internal'.
+	* modules/posix_spawn-internal: New file.
+	* lib/spawn_int.h: New file, from GNU libc with modifications.
+	* lib/spawni.c: New file, from GNU libc with modifications.
+	* m4/posix_spawn.m4: New file.
+
 	New module 'spawn'.
 	* modules/spawn: New file.
-	* lib/spawn.in.h: New file.
+	* lib/spawn.in.h: New file, from GNU libc with modifications.
 	* m4/spawn_h.m4: New file.
 	* doc/posix-headers/spawn.texi: Mention the new module.
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/spawn_int.h	Sun Sep 28 13:30:49 2008 +0200
@@ -0,0 +1,62 @@
+/* Copyright (C) 2000, 2008 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <sys/types.h>
+
+/* Data structure to contain the action information.  */
+struct __spawn_action
+{
+  enum
+  {
+    spawn_do_close,
+    spawn_do_dup2,
+    spawn_do_open
+  } tag;
+
+  union
+  {
+    struct
+    {
+      int fd;
+    } close_action;
+    struct
+    {
+      int fd;
+      int newfd;
+    } dup2_action;
+    struct
+    {
+      int fd;
+      const char *path;
+      int oflag;
+      mode_t mode;
+    } open_action;
+  } action;
+};
+
+#if !_LIBC
+# define __posix_spawn_file_actions_realloc gl_posix_spawn_file_actions_realloc
+#endif
+extern int __posix_spawn_file_actions_realloc (posix_spawn_file_actions_t *
+					       file_actions);
+
+#if !_LIBC
+# define __spawni gl_posix_spawn_internal
+#endif
+extern int __spawni (pid_t *pid, const char *path,
+		     const posix_spawn_file_actions_t *file_actions,
+		     const posix_spawnattr_t *attrp, char *const argv[],
+		     char *const envp[], int use_path);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/spawni.c	Sun Sep 28 13:30:49 2008 +0200
@@ -0,0 +1,352 @@
+/* Guts of POSIX spawn interface.  Generic POSIX.1 version.
+   Copyright (C) 2000-2005, 2006, 2008 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <spawn.h>
+#include "spawn_int.h"
+
+#include <alloca.h>
+#include <errno.h>
+
+#include <fcntl.h>
+#ifndef O_LARGEFILE
+# define O_LARGEFILE 0
+#endif
+
+#if _LIBC || HAVE_PATHS_H
+# include <paths.h>
+#else
+# define _PATH_BSHELL "/bin/sh"
+#endif
+
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#if _LIBC
+# include <not-cancel.h>
+#else
+# define close_not_cancel close
+# define open_not_cancel open
+#endif
+
+#if _LIBC
+# include <local-setxid.h>
+#else
+# if !HAVE_SETEUID
+#  define seteuid(id) setresuid (-1, id, -1)
+# endif
+# if !HAVE_SETEGID
+#  define setegid(id) setresgid (-1, id, -1)
+# endif
+# define local_seteuid(id) seteuid (id)
+# define local_setegid(id) setegid (id)
+#endif
+
+#if _LIBC
+# define alloca __alloca
+# define execve __execve
+# define dup2 __dup2
+# define fork __fork
+# define getgid __getgid
+# define getuid __getuid
+# define sched_setparam __sched_setparam
+# define sched_setscheduler __sched_setscheduler
+# define setpgid __setpgid
+# define sigaction __sigaction
+# define sigismember __sigismember
+# define sigprocmask __sigprocmask
+# define strchrnul __strchrnul
+# define vfork __vfork
+#else
+# undef internal_function
+# define internal_function /* empty */
+#endif
+
+
+/* The Unix standard contains a long explanation of the way to signal
+   an error after the fork() was successful.  Since no new wait status
+   was wanted there is no way to signal an error using one of the
+   available methods.  The committee chose to signal an error by a
+   normal program exit with the exit code 127.  */
+#define SPAWN_ERROR	127
+
+
+/* The file is accessible but it is not an executable file.  Invoke
+   the shell to interpret it as a script.  */
+static void
+internal_function
+script_execute (const char *file, char *const argv[], char *const envp[])
+{
+  /* Count the arguments.  */
+  int argc = 0;
+  while (argv[argc++])
+    ;
+
+  /* Construct an argument list for the shell.  */
+  {
+    char **new_argv = (char **) alloca ((argc + 1) * sizeof (char *));
+    new_argv[0] = (char *) _PATH_BSHELL;
+    new_argv[1] = (char *) file;
+    while (argc > 1)
+      {
+	new_argv[argc] = argv[argc - 1];
+	--argc;
+      }
+
+    /* Execute the shell.  */
+    execve (new_argv[0], new_argv, envp);
+  }
+}
+
+
+/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
+   Before running the process perform the actions described in FILE-ACTIONS. */
+int
+__spawni (pid_t *pid, const char *file,
+	  const posix_spawn_file_actions_t *file_actions,
+	  const posix_spawnattr_t *attrp, char *const argv[],
+	  char *const envp[], int use_path)
+{
+  pid_t new_pid;
+  char *path, *p, *name;
+  size_t len;
+  size_t pathlen;
+
+  /* Do this once.  */
+  short int flags = attrp == NULL ? 0 : attrp->_flags;
+
+  /* Generate the new process.  */
+#if HAVE_VFORK
+  if ((flags & POSIX_SPAWN_USEVFORK) != 0
+      /* If no major work is done, allow using vfork.  Note that we
+	 might perform the path searching.  But this would be done by
+	 a call to execvp(), too, and such a call must be OK according
+	 to POSIX.  */
+      || ((flags & (POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF
+		    | POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER
+		    | POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_RESETIDS)) == 0
+	  && file_actions == NULL))
+    new_pid = vfork ();
+  else
+#endif
+    new_pid = fork ();
+
+  if (new_pid != 0)
+    {
+      if (new_pid < 0)
+	return errno;
+
+      /* The call was successful.  Store the PID if necessary.  */
+      if (pid != NULL)
+	*pid = new_pid;
+
+      return 0;
+    }
+
+  /* Set signal mask.  */
+  if ((flags & POSIX_SPAWN_SETSIGMASK) != 0
+      && sigprocmask (SIG_SETMASK, &attrp->_ss, NULL) != 0)
+    _exit (SPAWN_ERROR);
+
+  /* Set signal default action.  */
+  if ((flags & POSIX_SPAWN_SETSIGDEF) != 0)
+    {
+      /* We have to iterate over all signals.  This could possibly be
+	 done better but it requires system specific solutions since
+	 the sigset_t data type can be very different on different
+	 architectures.  */
+      int sig;
+      struct sigaction sa;
+
+      memset (&sa, '\0', sizeof (sa));
+      sa.sa_handler = SIG_DFL;
+
+      for (sig = 1; sig <= NSIG; ++sig)
+	if (sigismember (&attrp->_sd, sig) != 0
+	    && sigaction (sig, &sa, NULL) != 0)
+	  _exit (SPAWN_ERROR);
+
+    }
+
+#if (_LIBC ? defined _POSIX_PRIORITY_SCHEDULING : HAVE_SCHED_SETPARAM && HAVE_SCHED_SETSCHEDULER)
+  /* Set the scheduling algorithm and parameters.  */
+  if ((flags & (POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER))
+      == POSIX_SPAWN_SETSCHEDPARAM)
+    {
+      if (sched_setparam (0, &attrp->_sp) == -1)
+	_exit (SPAWN_ERROR);
+    }
+  else if ((flags & POSIX_SPAWN_SETSCHEDULER) != 0)
+    {
+      if (sched_setscheduler (0, attrp->_policy,
+			      (flags & POSIX_SPAWN_SETSCHEDPARAM) != 0
+			      ? &attrp->_sp : NULL) == -1)
+	_exit (SPAWN_ERROR);
+    }
+#endif
+
+  /* Set the process group ID.  */
+  if ((flags & POSIX_SPAWN_SETPGROUP) != 0
+      && setpgid (0, attrp->_pgrp) != 0)
+    _exit (SPAWN_ERROR);
+
+  /* Set the effective user and group IDs.  */
+  if ((flags & POSIX_SPAWN_RESETIDS) != 0
+      && (local_seteuid (getuid ()) != 0
+	  || local_setegid (getgid ()) != 0))
+    _exit (SPAWN_ERROR);
+
+  /* Execute the file actions.  */
+  if (file_actions != NULL)
+    {
+      int cnt;
+
+      for (cnt = 0; cnt < file_actions->_used; ++cnt)
+	{
+	  struct __spawn_action *action = &file_actions->_actions[cnt];
+
+	  switch (action->tag)
+	    {
+	    case spawn_do_close:
+	      if (close_not_cancel (action->action.close_action.fd) != 0)
+		/* Signal the error.  */
+		_exit (SPAWN_ERROR);
+	      break;
+
+	    case spawn_do_open:
+	      {
+		int new_fd = open_not_cancel (action->action.open_action.path,
+					      action->action.open_action.oflag
+					      | O_LARGEFILE,
+					      action->action.open_action.mode);
+
+		if (new_fd == -1)
+		  /* The `open' call failed.  */
+		  _exit (SPAWN_ERROR);
+
+		/* Make sure the desired file descriptor is used.  */
+		if (new_fd != action->action.open_action.fd)
+		  {
+		    if (dup2 (new_fd, action->action.open_action.fd)
+			!= action->action.open_action.fd)
+		      /* The `dup2' call failed.  */
+		      _exit (SPAWN_ERROR);
+
+		    if (close_not_cancel (new_fd) != 0)
+		      /* The `close' call failed.  */
+		      _exit (SPAWN_ERROR);
+		  }
+	      }
+	      break;
+
+	    case spawn_do_dup2:
+	      if (dup2 (action->action.dup2_action.fd,
+			action->action.dup2_action.newfd)
+		  != action->action.dup2_action.newfd)
+		/* The `dup2' call failed.  */
+		_exit (SPAWN_ERROR);
+	      break;
+	    }
+	}
+    }
+
+  if (! use_path || strchr (file, '/') != NULL)
+    {
+      /* The FILE parameter is actually a path.  */
+      execve (file, argv, envp);
+
+      if (errno == ENOEXEC)
+	script_execute (file, argv, envp);
+
+      /* Oh, oh.  `execve' returns.  This is bad.  */
+      _exit (SPAWN_ERROR);
+    }
+
+  /* We have to search for FILE on the path.  */
+  path = getenv ("PATH");
+  if (path == NULL)
+    {
+#if HAVE_CONFSTR
+      /* There is no `PATH' in the environment.
+	 The default search path is the current directory
+	 followed by the path `confstr' returns for `_CS_PATH'.  */
+      len = confstr (_CS_PATH, (char *) NULL, 0);
+      path = (char *) alloca (1 + len);
+      path[0] = ':';
+      (void) confstr (_CS_PATH, path + 1, len);
+#else
+      /* Pretend that the PATH contains only the current directory.  */
+      path = "";
+#endif
+    }
+
+  len = strlen (file) + 1;
+  pathlen = strlen (path);
+  name = alloca (pathlen + len + 1);
+  /* Copy the file name at the top.  */
+  name = (char *) memcpy (name + pathlen + 1, file, len);
+  /* And add the slash.  */
+  *--name = '/';
+
+  p = path;
+  do
+    {
+      char *startp;
+
+      path = p;
+      p = strchrnul (path, ':');
+
+      if (p == path)
+	/* Two adjacent colons, or a colon at the beginning or the end
+	   of `PATH' means to search the current directory.  */
+	startp = name + 1;
+      else
+	startp = (char *) memcpy (name - (p - path), path, p - path);
+
+      /* Try to execute this name.  If it works, execv will not return.  */
+      execve (startp, argv, envp);
+
+      if (errno == ENOEXEC)
+	script_execute (startp, argv, envp);
+
+      switch (errno)
+	{
+	case EACCES:
+	case ENOENT:
+	case ESTALE:
+	case ENOTDIR:
+	  /* Those errors indicate the file is missing or not executable
+	     by us, in which case we want to just try the next path
+	     directory.  */
+	  break;
+
+	default:
+	  /* Some other error means we found an executable file, but
+	     something went wrong executing it; return the error to our
+	     caller.  */
+	  _exit (SPAWN_ERROR);
+	}
+    }
+  while (*p++ != '\0');
+
+  /* Return with an error.  */
+  _exit (SPAWN_ERROR);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m4/posix_spawn.m4	Sun Sep 28 13:30:49 2008 +0200
@@ -0,0 +1,54 @@
+# posix_spawn.m4 serial 1
+dnl Copyright (C) 2008 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Tests whether the entire posix_spawn facility is available.
+AC_DEFUN([gl_POSIX_SPAWN],
+[
+  AC_REQUIRE([gl_POSIX_SPAWN_BODY])
+])
+
+AC_DEFUN([gl_POSIX_SPAWN_BODY],
+[
+  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([posix_spawn])
+  dnl Assume that when the main function exists, all the others are
+  dnl available as well.
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnp])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_init])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addclose])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_adddup2])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addopen])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_destroy])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_init])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getflags])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setflags])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getpgroup])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setpgroup])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedparam])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedparam])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedpolicy])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedpolicy])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigdefault])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigdefault])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigmask])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigmask])
+  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_destroy])
+  if test $ac_cv_func_posix_spawn != yes; then
+    HAVE_POSIX_SPAWN=0
+    dnl For now, assume that if posix_spawn exists, it also works.
+    if false; then
+      REPLACE_POSIX_SPAWN=1
+    fi
+  fi
+])
+
+AC_DEFUN([gl_POSIX_SPAWN_INTERNAL],
+[
+  AC_LIBOBJ([spawni])
+  dnl Prerequisites of lib/spawni.c.
+  AC_CHECK_HEADERS([paths.h])
+  AC_CHECK_FUNCS([confstr sched_setparam sched_setscheduler setegid seteuid vfork])
+])
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/posix_spawn-internal	Sun Sep 28 13:30:49 2008 +0200
@@ -0,0 +1,25 @@
+Description:
+posix_spawn internals.
+
+Files:
+lib/spawni.c
+lib/spawn_int.h
+m4/posix_spawn.m4
+
+Depends-on:
+spawn
+alloca-opt
+strchrnul
+
+configure.ac:
+
+Makefile.am:
+
+Include:
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible, glibc
+