chown.c revision 4321:a8930ec16e52 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27/*	  All Rights Reserved  	*/
28
29/*
30 * Portions of this source code were derived from Berkeley 4.3 BSD
31 * under license from the Regents of the University of California.
32 */
33
34#pragma ident	"%Z%%M%	%I%	%E% SMI"
35
36#include <sys/param.h>
37#include <sys/isa_defs.h>
38#include <sys/types.h>
39#include <sys/sysmacros.h>
40#include <sys/systm.h>
41#include <sys/errno.h>
42#include <sys/fcntl.h>
43#include <sys/pathname.h>
44#include <sys/var.h>
45#include <sys/vfs.h>
46#include <sys/vnode.h>
47#include <sys/file.h>
48#include <sys/mode.h>
49#include <sys/proc.h>
50#include <sys/uio.h>
51#include <sys/filio.h>
52#include <sys/fcntl.h>
53#include <sys/debug.h>
54#include <c2/audit.h>
55
56/*
57 * nmflag has the following values
58 *
59 * 1 - Always do lookup.  i.e. chown, lchown.
60 * 2 - Name is optional i.e. fchownat
61 * 0 - Don't lookup name, vp is in file_p. i.e. fchown
62 *
63 */
64int
65cfchownat(int fd, char *name, int nmflag, uid_t uid, gid_t gid, int flags)
66{
67	vnode_t		*startvp, *vp;
68	file_t 		*filefp;
69	struct vattr 	vattr;
70	int 		error = 0;
71	char 		startchar;
72
73	if (uid != (uid_t)-1 && !VALID_UID(uid) ||
74	    gid != (gid_t)-1 && !VALID_GID(gid)) {
75		return (set_errno(EINVAL));
76	}
77	vattr.va_uid = uid;
78	vattr.va_gid = gid;
79	vattr.va_mask = 0;
80	if (vattr.va_uid != -1)
81		vattr.va_mask |= AT_UID;
82	if (vattr.va_gid != -1)
83		vattr.va_mask |= AT_GID;
84
85
86	if (fd == AT_FDCWD && name == NULL)
87		return (set_errno(EFAULT));
88
89	if (nmflag == 1 || (nmflag == 2 && name != NULL)) {
90		if (copyin(name, &startchar, sizeof (char)))
91			return (set_errno(EFAULT));
92	} else
93		startchar = '\0';
94
95
96	if (fd == AT_FDCWD)
97		startvp = NULL;
98	else {
99		/*
100		 * only get fd if not doing absolute lookup
101		 */
102		if (startchar != '/' || nmflag == 0) {
103			if ((filefp = getf(fd)) == NULL) {
104				return (set_errno(EBADF));
105			}
106			startvp = filefp->f_vnode;
107			VN_HOLD(startvp);
108			releasef(fd);
109		} else {
110			startvp = NULL;
111		}
112	}
113
114#if C2_AUDIT
115	if ((nmflag == 2) && audit_active)
116		audit_setfsat_path(1);
117#endif /* C2_AUDIT */
118
119	/*
120	 * Do lookups for chown, lchown and fchownat when name not NULL
121	 */
122	if ((nmflag == 2 && name != NULL) || nmflag == 1) {
123		if (error = lookupnameat(name, UIO_USERSPACE,
124		    (flags == AT_SYMLINK_NOFOLLOW) ?
125		    NO_FOLLOW : FOLLOW,
126		    NULLVPP, &vp, startvp)) {
127			if (startvp != NULL)
128				VN_RELE(startvp);
129			return (set_errno(error));
130		}
131	} else {
132		vp = startvp;
133		ASSERT(vp);
134		VN_HOLD(vp);
135	}
136
137	if (vn_is_readonly(vp)) {
138		error = EROFS;
139	} else {
140		error = VOP_SETATTR(vp, &vattr, 0, CRED(), NULL);
141	}
142
143	if (startvp != NULL)
144		VN_RELE(startvp);
145	if (vp != NULL)
146		VN_RELE(vp);
147
148	if (error != 0)
149		return (set_errno(error));
150	else
151		return (error);
152}
153/*
154 * Change ownership of file given file name.
155 */
156int
157chown(char *fname, uid_t uid, gid_t gid)
158{
159	return (cfchownat(AT_FDCWD, fname, 1, uid, gid, 0));
160}
161
162int
163lchown(char *fname, uid_t uid, gid_t gid)
164{
165	return (cfchownat(AT_FDCWD, fname, 1, uid, gid, AT_SYMLINK_NOFOLLOW));
166}
167
168/*
169 * Change ownership of file given file descriptor.
170 */
171int
172fchown(int fd, uid_t uid, uid_t gid)
173{
174	return (cfchownat(fd, NULL, 0, uid, gid, 0));
175}
176
177int
178fchownat(int fd, char *name, uid_t uid, gid_t gid, int flags)
179{
180	return (cfchownat(fd, name, 2, uid, gid, flags));
181
182}
183