funopen(): change seekfn argument to use off_t, not fpos_t

On BSD, fpos_t is typedef'd to off_t but some systems use a struct.
This means fpos_t is not a portable function argument or return value.
Both FreeBSD and the Linux libbsd funopen() have switched to off_t
for this--we should too.  From Joe Nelson.  OK deraadt@

2 files changed, 6 insertions, 11 deletions

diff --git a/lib/libc/stdio/funopen.3 b/lib/libc/stdio/funopen.3
index 5138bf1160b..0348e49304d 100644
--- a/lib/libc/stdio/funopen.3
+++ b/lib/libc/stdio/funopen.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: funopen.3,v 1.18 2015/11/04 21:30:13 tedu Exp $
+.\"	$OpenBSD: funopen.3,v 1.19 2022/01/05 20:57:27 millert Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: November 4 2015 $
+.Dd $Mdocdate: January 5 2022 $
 .Dt FUNOPEN 3
 .Os
 .Sh NAME
@@ -42,7 +42,7 @@
 .Ft FILE *
 .Fn funopen "const void *cookie" "int (*readfn)(void *, char *, int)" \
     "int (*writefn)(void *, const char *, int)" \
-    "fpos_t (*seekfn)(void *, fpos_t, int)" \
+    "off_t (*seekfn)(void *, off_t, int)" \
     "int (*closefn)(void *)"
 .Ft FILE *
 .Fn fropen "const void *cookie" "int (*readfn)(void *, char *, int)"
@@ -84,12 +84,7 @@ with the exceptions that they are passed the
 .Fa cookie
 argument specified to
 .Fn funopen
-in place of the traditional file descriptor argument and that
-the seek function takes an
-.Li fpos_t
-argument and not an
-.Li off_t
-argument.
+in place of the traditional file descriptor argument.
 .Pp
 Read and write I/O functions are allowed to change the underlying buffer
 on fully buffered or line buffered streams by calling
diff --git a/lib/libc/stdio/funopen.c b/lib/libc/stdio/funopen.c
index b6fc464b4aa..8c0aafbf204 100644
--- a/lib/libc/stdio/funopen.c
+++ b/lib/libc/stdio/funopen.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: funopen.c,v 1.9 2015/08/31 02:53:57 guenther Exp $ */
+/*	$OpenBSD: funopen.c,v 1.10 2022/01/05 20:57:27 millert Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -38,7 +38,7 @@
 FILE *
 funopen(const void *cookie, int (*readfn)(void *, char *, int),
 	int (*writefn)(void *, const char *, int),
-	fpos_t (*seekfn)(void *, fpos_t, int), int (*closefn)(void *))
+	off_t (*seekfn)(void *, off_t, int), int (*closefn)(void *))
 {
 	FILE *fp;
 	int flags;