Some platforms (notably, the BSDs) have a more efficient implementation called

closefrom(3).


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@168522 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 164802 .
+# From configure.ac Revision: 166058 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for asterisk 1.6.
 #
@@ -15678,7 +15678,8 @@ done
 
 
 
-for ac_func in asprintf atexit dup2 endpwent ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday ioperm inet_ntoa isascii localtime_r memchr memmove memset mkdir munmap putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtol strtoq unsetenv utime vasprintf getpeereid sysctl swapctl
+
+for ac_func in asprintf atexit closefrom dup2 endpwent ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday ioperm inet_ntoa isascii localtime_r memchr memmove memset mkdir munmap putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtol strtoq unsetenv utime vasprintf getpeereid sysctl swapctl
 do
 as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { echo "$as_me:$LINENO: checking for $ac_func" >&5

configure.ac

@@ -337,7 +337,7 @@ AC_FUNC_STRNLEN
 AC_FUNC_STRTOD
 AC_FUNC_UTIME_NULL
 AC_FUNC_VPRINTF
-AC_CHECK_FUNCS([asprintf atexit dup2 endpwent ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday ioperm inet_ntoa isascii localtime_r memchr memmove memset mkdir munmap putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtol strtoq unsetenv utime vasprintf getpeereid sysctl swapctl])
+AC_CHECK_FUNCS([asprintf atexit closefrom dup2 endpwent ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday ioperm inet_ntoa isascii localtime_r memchr memmove memset mkdir munmap putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtol strtoq unsetenv utime vasprintf getpeereid sysctl swapctl])
 
 AC_CHECK_FUNCS([glob])
 

include/asterisk/autoconfig.h.in

@@ -153,6 +153,9 @@
 /* Define to 1 if your system has a working `chown' function. */
 #undef HAVE_CHOWN
 
+/* Define to 1 if you have the `closefrom' function. */
+#undef HAVE_CLOSEFROM
+
 /* Define this to indicate the ${COS_DESCRIP} library */
 #undef HAVE_COS
 

main/app.c

@@ -33,6 +33,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <regex.h>
 #include <sys/file.h> /* added this to allow to compile, sorry! */
 #include <signal.h>
+#include <sys/time.h>       /* for getrlimit(2) */
+#include <sys/resource.h>   /* for getrlimit(2) */
+#include <stdlib.h>         /* for closefrom(3) */
 
 #include "asterisk/paths.h"	/* use ast_config_AST_DATA_DIR */
 #include "asterisk/channel.h"
@@ -1839,18 +1842,24 @@ int ast_get_encoded_str(const char *stream, char *result, size_t result_size)
 
 void ast_close_fds_above_n(int n)
 {
+#ifdef HAVE_CLOSEFROM
+	closefrom(n + 1);
+#else
 	int x, null;
+	struct rlimit rl;
+	getrlimit(RLIMIT_NOFILE, &rl);
 	null = open("/dev/null", O_RDONLY);
-	for (x = n + 1; x <= (null >= 8192 ? null : 8192); x++) {
+	for (x = n + 1; x < rl.rlim_max; x++) {
 		if (x != null) {
 			/* Side effect of dup2 is that it closes any existing fd without error.
 			 * This prevents valgrind and other debugging tools from sending up
 			 * false error reports. */
-			dup2(null, x);
+			while (dup2(null, x) < 0 && errno == EINTR);
 			close(x);
 		}
 	}
 	close(null);
+#endif
 }
 
 int ast_safe_fork(int stop_reaper)