Add mkostemp() and mkostemps().

These are like mkstemp() and mkstemps() but allow passing open(2) flags like
O_CLOEXEC.

4 files changed, 106 insertions, 21 deletions

diff --git a/lib/libc/stdio/Makefile.inc b/lib/libc/stdio/Makefile.inc
index 0062d3d..419d031 100644
--- a/lib/libc/stdio/Makefile.inc
+++ b/lib/libc/stdio/Makefile.inc
@@ -60,7 +60,8 @@ MLINKS+=getc.3 fgetc.3 getc.3 getc_unlocked.3 getc.3 getchar.3 \
 	getc.3 getchar_unlocked.3 getc.3 getw.3
 MLINKS+=getline.3 getdelim.3
 MLINKS+=getwc.3 fgetwc.3 getwc.3 getwchar.3
-MLINKS+=mktemp.3 mkdtemp.3 mktemp.3 mkstemp.3 mktemp.3 mkstemps.3
+MLINKS+=mktemp.3 mkdtemp.3 mktemp.3 mkstemp.3 mktemp.3 mkstemps.3 \
+	mktemp.3 mkostemp.3 mktemp.3 mkostemps.3
 MLINKS+=open_memstream.3 open_wmemstream.3
 MLINKS+=printf.3 asprintf.3 printf.3 dprintf.3 printf.3 fprintf.3 \
 	printf.3 snprintf.3 printf.3 sprintf.3 \
diff --git a/lib/libc/stdio/Symbol.map b/lib/libc/stdio/Symbol.map
index 538b29a..d2a8c92 100644
--- a/lib/libc/stdio/Symbol.map
+++ b/lib/libc/stdio/Symbol.map
@@ -158,6 +158,8 @@ FBSD_1.3 {
 	fmemopen;
 	open_memstream;
 	open_wmemstream;
+	mkostemp;
+	mkostemps;
 };
 
 FBSDprivate_1.0 {
diff --git a/lib/libc/stdio/mktemp.3 b/lib/libc/stdio/mktemp.3
index 6a46cf0..816a6b6 100644
--- a/lib/libc/stdio/mktemp.3
+++ b/lib/libc/stdio/mktemp.3
@@ -28,7 +28,7 @@
 .\"     @(#)mktemp.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd July 5, 2013
+.Dd August 8, 2013
 .Dt MKTEMP 3
 .Os
 .Sh NAME
@@ -42,6 +42,10 @@
 .Fn mktemp "char *template"
 .Ft int
 .Fn mkstemp "char *template"
+.Ft int
+.Fn mkostemp "char *template" "int oflags"
+.Ft int
+.Fn mkostemps "char *template" "int suffixlen" "int oflags"
 .Ft char *
 .Fn mkdtemp "char *template"
 .In unistd.h
@@ -85,16 +89,41 @@ This avoids the race between testing for a file's existence and opening it
 for use.
 .Pp
 The
+.Fn mkostemp
+function
+is like
+.Fn mkstemp
+but allows specifying additional
+.Xr open 2
+flags (defined in
+.In fcntl.h ) .
+The permitted flags are
+.Dv O_APPEND ,
+.Dv O_DIRECT ,
+.Dv O_SHLOCK ,
+.Dv O_EXLOCK ,
+.Dv O_SYNC
+and
+.Dv O_CLOEXEC .
+.Pp
+The
 .Fn mkstemps
-function acts the same as
-.Fn mkstemp ,
-except it permits a suffix to exist in the template.
+and
+.Fn mkostemps
+functions act the same as
+.Fn mkstemp
+and
+.Fn mkostemp
+respectively,
+except they permit a suffix to exist in the template.
 The template should be of the form
 .Pa /tmp/tmpXXXXXXsuffix .
 The
 .Fn mkstemps
+and
+.Fn mkostemps
 function
-is told the length of the suffix string.
+are told the length of the suffix string.
 .Pp
 The
 .Fn mkdtemp
@@ -110,9 +139,11 @@ functions return a pointer to the template on success and
 .Dv NULL
 on failure.
 The
-.Fn mkstemp
-and
+.Fn mkstemp ,
+.Fn mkostemp
 .Fn mkstemps
+and
+.Fn mkostemps
 functions
 return \-1 if no suitable file could be created.
 If either call fails an error code is placed in the global variable
@@ -120,7 +151,9 @@ If either call fails an error code is placed in the global variable
 .Sh ERRORS
 The
 .Fn mkstemp ,
-.Fn mkstemps
+.Fn mkostemp ,
+.Fn mkstemps ,
+.Fn mkostemps
 and
 .Fn mkdtemp
 functions
@@ -133,8 +166,25 @@ The pathname portion of the template is not an existing directory.
 .El
 .Pp
 The
+.Fn mkostemp
+and
+.Fn mkostemps
+functions
+may also set
+.Va errno
+to the following value:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The
+.Fa oflags
+argument is invalid.
+.El
+.Pp
+The
 .Fn mkstemp ,
-.Fn mkstemps
+.Fn mkostemp ,
+.Fn mkstemps ,
+.Fn mkostemps
 and
 .Fn mkdtemp
 functions
@@ -145,9 +195,11 @@ to any value specified by the
 function.
 .Pp
 The
-.Fn mkstemp
-and
+.Fn mkstemp ,
+.Fn mkostemp ,
 .Fn mkstemps
+and
+.Fn mkostemps
 functions
 may also set
 .Va errno
@@ -209,8 +261,11 @@ function is expected to conform to
 and is not specified by
 .St -p1003.1-2008 .
 The
+.Fn mkostemp ,
 .Fn mkstemps
-function does not conform to any standard.
+and
+.Fn mkostemps
+functions do not conform to any standard.
 .Sh HISTORY
 A
 .Fn mktemp
@@ -232,6 +287,12 @@ function first appeared in
 .Ox 2.4 ,
 and later in
 .Fx 3.4 .
+The
+.Fn mkostemp
+and
+.Fn mkostemps
+functions appeared in
+.Fx 10.0 .
 .Sh BUGS
 This family of functions produces filenames which can be guessed,
 though the risk is minimized when large numbers of
@@ -248,6 +309,8 @@ and opening it for use
 particularly dangerous from a security perspective.
 Whenever it is possible,
 .Fn mkstemp
+or
+.Fn mkostemp
 should be used instead, since it does not have the race condition.
 If
 .Fn mkstemp
diff --git a/lib/libc/stdio/mktemp.c b/lib/libc/stdio/mktemp.c
index 58783dd..6fc552a 100644
--- a/lib/libc/stdio/mktemp.c
+++ b/lib/libc/stdio/mktemp.c
@@ -47,17 +47,33 @@ __FBSDID("$FreeBSD$");
 
 char *_mktemp(char *);
 
-static int _gettemp(char *, int *, int, int);
+static int _gettemp(char *, int *, int, int, int);
 
 static const unsigned char padchar[] =
 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
 int
+mkostemps(char *path, int slen, int oflags)
+{
+	int fd;
+
+	return (_gettemp(path, &fd, 0, slen, oflags) ? fd : -1);
+}
+
+int
 mkstemps(char *path, int slen)
 {
 	int fd;
 
-	return (_gettemp(path, &fd, 0, slen) ? fd : -1);
+	return (_gettemp(path, &fd, 0, slen, 0) ? fd : -1);
+}
+
+int
+mkostemp(char *path, int oflags)
+{
+	int fd;
+
+	return (_gettemp(path, &fd, 0, 0, oflags) ? fd : -1);
 }
 
 int
@@ -65,19 +81,19 @@ mkstemp(char *path)
 {
 	int fd;
 
-	return (_gettemp(path, &fd, 0, 0) ? fd : -1);
+	return (_gettemp(path, &fd, 0, 0, 0) ? fd : -1);
 }
 
 char *
 mkdtemp(char *path)
 {
-	return (_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
+	return (_gettemp(path, (int *)NULL, 1, 0, 0) ? path : (char *)NULL);
 }
 
 char *
 _mktemp(char *path)
 {
-	return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL);
+	return (_gettemp(path, (int *)NULL, 0, 0, 0) ? path : (char *)NULL);
 }
 
 __warn_references(mktemp,
@@ -90,7 +106,7 @@ mktemp(char *path)
 }
 
 static int
-_gettemp(char *path, int *doopen, int domkdir, int slen)
+_gettemp(char *path, int *doopen, int domkdir, int slen, int oflags)
 {
 	char *start, *trv, *suffp, *carryp;
 	char *pad;
@@ -99,7 +115,9 @@ _gettemp(char *path, int *doopen, int domkdir, int slen)
 	uint32_t rand;
 	char carrybuf[MAXPATHLEN];
 
-	if ((doopen != NULL && domkdir) || slen < 0) {
+	if ((doopen != NULL && domkdir) || slen < 0 ||
+	    (oflags & ~(O_APPEND | O_DIRECT | O_SHLOCK | O_EXLOCK | O_SYNC |
+	    O_CLOEXEC)) != 0) {
 		errno = EINVAL;
 		return (0);
 	}
@@ -151,7 +169,8 @@ _gettemp(char *path, int *doopen, int domkdir, int slen)
 	for (;;) {
 		if (doopen) {
 			if ((*doopen =
-			    _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
+			    _open(path, O_CREAT|O_EXCL|O_RDWR|oflags, 0600)) >=
+			    0)
 				return (1);
 			if (errno != EEXIST)
 				return (0);