[src/trunk]: src implement lchflags(2), which does the chflags(2) dance witho...

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

details:   https://anonhg.NetBSD.org/src/rev/8e83cf286439
branches:  trunk
changeset: 485047:8e83cf286439
user:      mrg <mrg%NetBSD.org@localhost>
date:      Mon Apr 17 14:31:21 2000 +0000

description:
implement lchflags(2), which does the chflags(2) dance without following
symlinks, and thus can operate on symlinks.  remove a bogus comment in
chflags(1) that claims symlinks do not have file flags.

XXX: todo -- make chflags(1) use lchflags(2) when given the right options.

diffstat:

 lib/libc/sys/Makefile.inc |   4 ++--
 lib/libc/sys/chflags.2    |  12 +++++++++++-
 sys/kern/syscalls.master  |   3 ++-
 sys/kern/vfs_syscalls.c   |  45 ++++++++++++++++++++++++++++++++++++++++++++-
 sys/sys/stat.h            |   3 ++-
 usr.bin/chflags/chflags.1 |   9 +--------
 6 files changed, 62 insertions(+), 14 deletions(-)

diffs (168 lines):

diff -r c8b865d42f33 -r 8e83cf286439 lib/libc/sys/Makefile.inc
--- a/lib/libc/sys/Makefile.inc Mon Apr 17 12:25:45 2000 +0000
+++ b/lib/libc/sys/Makefile.inc Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: Makefile.inc,v 1.98 2000/01/31 15:14:19 christos Exp $
+#      $NetBSD: Makefile.inc,v 1.99 2000/04/17 14:31:21 mrg Exp $
 #      @(#)Makefile.inc        8.3 (Berkeley) 10/24/94
 
 # sys sources
@@ -46,7 +46,7 @@
        __getlogin.o getpeername.o getpgid.o getpgrp.o \
        getpriority.o getrlimit.o getrusage.o getsid.o getsockname.o \
        getsockopt.o gettimeofday.o ioctl.o kill.o ktrace.o \
-       lchmod.o lchown.o __lstat13.o lfs_bmapv.o lfs_markv.o \
+       lchflags.o lchmod.o lchown.o __lstat13.o lfs_bmapv.o lfs_markv.o \
        lfs_segclean.o lfs_segwait.o link.o listen.o lutimes.o \
        madvise.o mincore.o minherit.o mkdir.o mkfifo.o mknod.o \
        mlock.o mlockall.o mount.o mprotect.o __msgctl13.o msgget.o msgrcv.o \
diff -r c8b865d42f33 -r 8e83cf286439 lib/libc/sys/chflags.2
--- a/lib/libc/sys/chflags.2    Mon Apr 17 12:25:45 2000 +0000
+++ b/lib/libc/sys/chflags.2    Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: chflags.2,v 1.15 1999/12/02 21:42:36 kleink Exp $
+.\"    $NetBSD: chflags.2,v 1.16 2000/04/17 14:31:21 mrg Exp $
 .\"
 .\" Copyright (c) 1989, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -48,6 +48,8 @@
 .Ft int
 .Fn chflags "const char *path"  "u_long flags"
 .Ft int
+.Fn lchflags "const char *path"  "u_long flags"
+.Ft int
 .Fn fchflags "int fd" "u_long flags"
 .Sh DESCRIPTION
 The file whose name
@@ -57,6 +59,10 @@
 .Fa fd
 has its flags changed to
 .Fa flags .
+For
+.Fn lchflags ,
+symbolic links are not traversed and thus their modes may be changed with
+this call.
 .Pp
 The flags specified are formed by
 .Em or Ns 'ing
@@ -179,3 +185,7 @@
 .Fn fchflags
 functions first appeared in
 .Bx 4.4 .
+The
+.Fn lchflags
+function first appeared in
+.Nx 1.5 .
diff -r c8b865d42f33 -r 8e83cf286439 sys/kern/syscalls.master
--- a/sys/kern/syscalls.master  Mon Apr 17 12:25:45 2000 +0000
+++ b/sys/kern/syscalls.master  Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-       $NetBSD: syscalls.master,v 1.99 2000/01/31 15:12:30 christos Exp $
+       $NetBSD: syscalls.master,v 1.100 2000/04/17 14:31:22 mrg Exp $
 
 ;      @(#)syscalls.master     8.2 (Berkeley) 1/13/94
 
@@ -583,3 +583,4 @@
 #else
 303    EXCL            __shmctl13
 #endif
+304    STD             { int sys_lchflags(const char *path, u_long flags); }
diff -r c8b865d42f33 -r 8e83cf286439 sys/kern/vfs_syscalls.c
--- a/sys/kern/vfs_syscalls.c   Mon Apr 17 12:25:45 2000 +0000
+++ b/sys/kern/vfs_syscalls.c   Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_syscalls.c,v 1.155 2000/03/30 09:27:15 augustss Exp $      */
+/*     $NetBSD: vfs_syscalls.c,v 1.156 2000/04/17 14:31:22 mrg Exp $   */
 
 /*
  * Copyright (c) 1989, 1993
@@ -2132,6 +2132,49 @@
 }
 
 /*
+ * Change flags of a file given a file descriptor; this version does
+ * not follow links.
+ */
+int
+sys_lchflags(p, v, retval)
+       struct proc *p;
+       void *v;
+       register_t *retval;
+{
+       register struct sys_chflags_args /* {
+               syscallarg(const char *) path;
+               syscallarg(u_long) flags;
+       } */ *uap = v;
+       register struct vnode *vp;
+       struct vattr vattr;
+       int error;
+       struct nameidata nd;
+
+       NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+       if ((error = namei(&nd)) != 0)
+               return (error);
+       vp = nd.ni_vp;
+       VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
+       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+       /* Non-superusers cannot change the flags on devices, even if they
+          own them. */
+       if (suser(p->p_ucred, &p->p_acflag)) {
+               if ((error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) != 0)
+                       goto out;
+               if (vattr.va_type == VCHR || vattr.va_type == VBLK) {
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+       VATTR_NULL(&vattr);
+       vattr.va_flags = SCARG(uap, flags);
+       error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
+out:
+       vput(vp);
+       return (error);
+}
+
+/*
  * Change mode of a file given path name; this version follows links.
  */
 /* ARGSUSED */
diff -r c8b865d42f33 -r 8e83cf286439 sys/sys/stat.h
--- a/sys/sys/stat.h    Mon Apr 17 12:25:45 2000 +0000
+++ b/sys/sys/stat.h    Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: stat.h,v 1.39 2000/02/03 02:01:53 cgd Exp $    */
+/*     $NetBSD: stat.h,v 1.40 2000/04/17 14:31:23 mrg Exp $    */
 
 /*-
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -288,6 +288,7 @@
 #if !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)
 int    chflags __P((const char *, unsigned long));
 int    fchflags __P((int, unsigned long));
+int    lchflags __P((const char *, unsigned long));
 int    lchmod __P((const char *, mode_t));
 #endif /* !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) */
 __END_DECLS
diff -r c8b865d42f33 -r 8e83cf286439 usr.bin/chflags/chflags.1
--- a/usr.bin/chflags/chflags.1 Mon Apr 17 12:25:45 2000 +0000
+++ b/usr.bin/chflags/chflags.1 Mon Apr 17 14:31:21 2000 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: chflags.1,v 1.9 1999/07/31 03:24:46 christos Exp $
+.\"    $NetBSD: chflags.1,v 1.10 2000/04/17 14:31:23 mrg Exp $
 .\"
 .\" Copyright (c) 1989, 1990, 1993, 1994
 .\"    The Regents of the University of California.  All rights reserved.
@@ -98,13 +98,6 @@
 nouchg the immutable bit should be cleared
 .Ed
 .Pp
-Symbolic links do not have flags, so unless the
-.Fl H
-or
-.Fl L
-option is set,
-.Nm
-on a symbolic link always succeeds and has no effect.
 The
 .Fl H ,
 .Fl L