[src/trunk]: src/sys/sys struct file: bump f_count and f_msgcount to u_int, t...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3d3f7f6c374a
branches:  trunk
changeset: 519499:3d3f7f6c374a
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Dec 18 22:29:25 2001 +0000

description:
struct file: bump f_count and f_msgcount to u_int, to protect against
counter overflow. Fixes kern/5080 by David A. Holland.
Also move f_usecount & f_iflags to better place, and make f_type int.

Note: the maximum possible number of references to a struct file is
maxfiles + unp_rights == 2 * INT_MAX

diffstat:

 sys/sys/file.h |  15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diffs (39 lines):

diff -r 97751c9a3d33 -r 3d3f7f6c374a sys/sys/file.h
--- a/sys/sys/file.h    Tue Dec 18 19:43:24 2001 +0000
+++ b/sys/sys/file.h    Tue Dec 18 22:29:25 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: file.h,v 1.30 2001/12/07 07:09:30 jdolecek Exp $       */
+/*     $NetBSD: file.h,v 1.31 2001/12/18 22:29:25 jdolecek Exp $       */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -56,13 +56,14 @@
 struct file {
        LIST_ENTRY(file) f_list;        /* list of active files */
        int             f_flag;         /* see fcntl.h */
+       int             f_iflags;       /* internal flags */
 #define        DTYPE_VNODE     1               /* file */
 #define        DTYPE_SOCKET    2               /* communications endpoint */
 #define        DTYPE_PIPE      3               /* pipe */
-       short           f_type;         /* descriptor type */
-       short           f_count;        /* reference count */
-       short           f_msgcount;     /* references from message queue */
-       short           f_pad0;         /* spare */
+       int             f_type;         /* descriptor type */
+       u_int           f_count;        /* reference count */
+       u_int           f_msgcount;     /* references from message queue */
+       int             f_usecount;     /* number active users */
        struct ucred    *f_cred;        /* creds associated with descriptor */
        struct fileops {
                int     (*fo_read)      (struct file *fp, off_t *offset,
@@ -82,9 +83,7 @@
                int     (*fo_close)     (struct file *fp, struct proc *p);
        } *f_ops;
        off_t           f_offset;
-       caddr_t         f_data;         /* vnode or socket */
-       int             f_iflags;       /* internal flags */
-       int             f_usecount;     /* number active users */
+       caddr_t         f_data;         /* descriptor data, e.g. vnode/socket */
 };
 
 #define        FIF_WANTCLOSE           0x01    /* a close is waiting for usecount */