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      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 2008 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	"@(#)chown.c	1.13	08/01/04 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  */
     64 int
     65 cfchownat(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 	struct zone	*zone = crgetzone(CRED());
     73 
     74 	if (uid != (uid_t)-1 && !VALID_UID(uid, zone) ||
     75 	    gid != (gid_t)-1 && !VALID_GID(gid, zone)) {
     76 		return (set_errno(EINVAL));
     77 	}
     78 	vattr.va_uid = uid;
     79 	vattr.va_gid = gid;
     80 	vattr.va_mask = 0;
     81 	if (vattr.va_uid != -1)
     82 		vattr.va_mask |= AT_UID;
     83 	if (vattr.va_gid != -1)
     84 		vattr.va_mask |= AT_GID;
     85 
     86 
     87 	if (fd == AT_FDCWD && name == NULL)
     88 		return (set_errno(EFAULT));
     89 
     90 	if (nmflag == 1 || (nmflag == 2 && name != NULL)) {
     91 		if (copyin(name, &startchar, sizeof (char)))
     92 			return (set_errno(EFAULT));
     93 	} else
     94 		startchar = '\0';
     95 
     96 
     97 	if (fd == AT_FDCWD)
     98 		startvp = NULL;
     99 	else {
    100 		/*
    101 		 * only get fd if not doing absolute lookup
    102 		 */
    103 		if (startchar != '/' || nmflag == 0) {
    104 			if ((filefp = getf(fd)) == NULL) {
    105 				return (set_errno(EBADF));
    106 			}
    107 			startvp = filefp->f_vnode;
    108 			VN_HOLD(startvp);
    109 			releasef(fd);
    110 		} else {
    111 			startvp = NULL;
    112 		}
    113 	}
    114 
    115 	if ((nmflag == 2) && audit_active)
    116 		audit_setfsat_path(1);
    117 
    118 	/*
    119 	 * Do lookups for chown, lchown and fchownat when name not NULL
    120 	 */
    121 	if ((nmflag == 2 && name != NULL) || nmflag == 1) {
    122 		if (error = lookupnameat(name, UIO_USERSPACE,
    123 		    (flags == AT_SYMLINK_NOFOLLOW) ?
    124 		    NO_FOLLOW : FOLLOW,
    125 		    NULLVPP, &vp, startvp)) {
    126 			if (startvp != NULL)
    127 				VN_RELE(startvp);
    128 			return (set_errno(error));
    129 		}
    130 	} else {
    131 		vp = startvp;
    132 		ASSERT(vp);
    133 		VN_HOLD(vp);
    134 	}
    135 
    136 	if (vn_is_readonly(vp)) {
    137 		error = EROFS;
    138 	} else {
    139 		error = VOP_SETATTR(vp, &vattr, 0, CRED(), NULL);
    140 	}
    141 
    142 	if (startvp != NULL)
    143 		VN_RELE(startvp);
    144 	if (vp != NULL)
    145 		VN_RELE(vp);
    146 
    147 	if (error != 0)
    148 		return (set_errno(error));
    149 	else
    150 		return (error);
    151 }
    152 /*
    153  * Change ownership of file given file name.
    154  */
    155 int
    156 chown(char *fname, uid_t uid, gid_t gid)
    157 {
    158 	return (cfchownat(AT_FDCWD, fname, 1, uid, gid, 0));
    159 }
    160 
    161 int
    162 lchown(char *fname, uid_t uid, gid_t gid)
    163 {
    164 	return (cfchownat(AT_FDCWD, fname, 1, uid, gid, AT_SYMLINK_NOFOLLOW));
    165 }
    166 
    167 /*
    168  * Change ownership of file given file descriptor.
    169  */
    170 int
    171 fchown(int fd, uid_t uid, uid_t gid)
    172 {
    173 	return (cfchownat(fd, NULL, 0, uid, gid, 0));
    174 }
    175 
    176 int
    177 fchownat(int fd, char *name, uid_t uid, gid_t gid, int flags)
    178 {
    179 	return (cfchownat(fd, name, 2, uid, gid, flags));
    180 
    181 }
    182