Commit 943939d0 authored by Guillem Jover's avatar Guillem Jover

Add new closefrom() function

Code taken from sudo, man page from FreeBSD.
parent 3d614131
......@@ -174,6 +174,33 @@
--
Copyright (c) 2009 Advanced Computing Technologies LLC
Written by: John H. Baldwin <jhb@FreeBSD.org>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
--
Copyright © 1998, M. Warner Losh <imp@freebsd.org>
All rights reserved.
......@@ -349,7 +376,8 @@
--
Copyright © 2000-2002, 2007 Todd C. Miller <Todd.Miller@courtesan.com>
Copyright © 2000-2002, 2004-2005, 2007, 2010
Todd C. Miller <Todd.Miller@courtesan.com>
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
......
......@@ -25,6 +25,7 @@ AC_PROG_LN_S
# Checks for libraries.
# Checks for header files.
AC_CHECK_HEADERS([sys/ndir.h sys/dir.h dir.h dirent.h])
# Checks for typedefs, structures, and compiler characteristics.
AC_TYPE_UID_T
......@@ -36,6 +37,13 @@ AC_TYPE_PID_T
AC_TYPE_SIZE_T
AC_TYPE_SSIZE_T
AC_CHECK_DECL([F_CLOSEM],
[AC_DEFINE([HAVE_FCNTL_CLOSEM], [1],
[Define to 1 if you have fcntl(F_CLOSEM)])],
[],
[#include <limits.h>
#include <fcntl.h>])
# Checks for library functions.
AC_MSG_CHECKING([for __progname])
AC_LINK_IFELSE(
......@@ -46,7 +54,7 @@ AC_LINK_IFELSE(
AC_MSG_RESULT([yes])],
[AC_MSG_RESULT([no])])
AC_CHECK_FUNCS([getexecname])
AC_CHECK_FUNCS([dirfd getexecname sysconf])
AC_CONFIG_FILES([
Makefile
......
......@@ -54,6 +54,8 @@ int bsd_getopt(int argc, char * const argv[], const char *shortopts);
mode_t getmode(const void *set, mode_t mode);
void *setmode(const char *mode_str);
void closefrom(int lowfd);
void setproctitle(const char *fmt, ...);
int getpeereid(int s, uid_t *euid, gid_t *egid);
......
......@@ -19,6 +19,7 @@ dist_man_MANS = \
arc4random_buf.3 \
arc4random_stir.3 \
arc4random_uniform.3 \
closefrom.3 \
dehumanize_number.3 \
fgetln.3 \
flopen.3 \
......
.\" Copyright (c) 2009 Advanced Computing Technologies LLC
.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd June 12, 2009
.Dt CLOSEFROM 3
.Os
.Sh NAME
.Nm closefrom
.Nd delete open file descriptors
.Sh LIBRARY
.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
.Lb libbsd
.Sh SYNOPSIS
.In bsd/unistd.h
.Ft void
.Fn closefrom "int lowfd"
.Sh DESCRIPTION
The
.Fn closefrom
system call deletes all open file descriptors greater than or equal to
.Fa lowfd
from the per-process object reference table.
Any errors encountered while closing file descriptors are ignored.
.Sh SEE ALSO
.Xr close 2
.Sh HISTORY
The
.Fn closefrom
function first appeared in
.Fx 8.0 .
......@@ -41,6 +41,7 @@ libbsd_la_LDFLAGS = \
libbsd_la_SOURCES = \
arc4random.c \
bsd_getopt.c \
closefrom.c \
dehumanize_number.c \
err.c \
fgetln.c \
......
/*
* Copyright (c) 2004-2005, 2007, 2010
* Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#include <fcntl.h>
#ifdef HAVE_DIRENT_H
# include <dirent.h>
# define NAMLEN(dirent) strlen((dirent)->d_name)
#else
# define dirent direct
# define NAMLEN(dirent) (dirent)->d_namlen
# ifdef HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# ifdef HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# ifdef HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#ifndef OPEN_MAX
# define OPEN_MAX 256
#endif
#ifndef HAVE_FCNTL_CLOSEM
# ifndef HAVE_DIRFD
# define closefrom_fallback closefrom
# endif
#endif
/*
* Close all file descriptors greater than or equal to lowfd.
* This is the expensive (ballback) method.
*/
void
closefrom_fallback(int lowfd)
{
long fd, maxfd;
/*
* Fall back on sysconf() or getdtablesize(). We avoid checking
* resource limits since it is possible to open a file descriptor
* and then drop the rlimit such that it is below the open fd.
*/
#ifdef HAVE_SYSCONF
maxfd = sysconf(_SC_OPEN_MAX);
#else
maxfd = getdtablesize();
#endif /* HAVE_SYSCONF */
if (maxfd < 0)
maxfd = OPEN_MAX;
for (fd = lowfd; fd < maxfd; fd++)
(void)close((int)fd);
}
/*
* Close all file descriptors greater than or equal to lowfd.
* We try the fast way first, falling back on the slow method.
*/
#ifdef HAVE_FCNTL_CLOSEM
void
closefrom(int lowfd)
{
if (fcntl(lowfd, F_CLOSEM, 0) == -1)
closefrom_fallback(lowfd);
}
#else
# ifdef HAVE_DIRFD
void
closefrom(int lowfd)
{
struct dirent *dent;
DIR *dirp;
char *endp;
long fd;
/* Use /proc/self/fd directory if it exists. */
dirp = opendir("/proc/self/fd");
if (dirp != NULL) {
while ((dent = readdir(dirp)) != NULL) {
fd = strtol(dent->d_name, &endp, 10);
if (dent->d_name != endp && *endp == '\0' &&
fd >= 0 && fd < INT_MAX && fd >= lowfd &&
fd != dirfd(dirp))
(void)close((int)fd);
}
(void)closedir(dirp);
} else
closefrom_fallback(lowfd);
}
#endif /* HAVE_DIRFD */
#endif /* HAVE_FCNTL_CLOSEM */
......@@ -89,3 +89,7 @@ LIBBSD_0.3 {
fpurge;
} LIBBSD_0.2;
LIBBSD_0.4 {
closefrom;
} LIBBSD_0.3;
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