xref: /illumos-gate/usr/src/uts/common/syscall/link.c (revision 4f364e7c95ee7fd9d5bbeddc1940e92405bb0e72)
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 /*
23  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
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 #include <sys/param.h>
35 #include <sys/isa_defs.h>
36 #include <sys/types.h>
37 #include <sys/sysmacros.h>
38 #include <sys/systm.h>
39 #include <sys/errno.h>
40 #include <sys/vnode.h>
41 #include <sys/file.h>
42 #include <sys/fcntl.h>
43 #include <sys/uio.h>
44 #include <sys/debug.h>
45 #include <c2/audit.h>
46 
47 /*
48  * Make a hard link.
49  */
50 int
51 linkat(int ffd, char *from, int tfd, char *to, int flag)
52 {
53 	vnode_t *fstartvp = NULL;
54 	vnode_t *tstartvp = NULL;
55 	enum symfollow follow;
56 	int error;
57 
58 	if (flag & ~AT_SYMLINK_FOLLOW)
59 		return (set_errno(EINVAL));
60 	follow = (flag & AT_SYMLINK_FOLLOW)? FOLLOW : NO_FOLLOW;
61 
62 	if (from == NULL || to == NULL)
63 		return (set_errno(EFAULT));
64 	if ((error = fgetstartvp(ffd, from, &fstartvp)) != 0)
65 		goto out;
66 	if ((error = fgetstartvp(tfd, to, &tstartvp)) != 0)
67 		goto out;
68 
69 	error = vn_linkat(fstartvp, from, follow, tstartvp, to, UIO_USERSPACE);
70 
71 out:
72 	if (fstartvp != NULL)
73 		VN_RELE(fstartvp);
74 	if (tstartvp != NULL)
75 		VN_RELE(tstartvp);
76 	if (error)
77 		return (set_errno(error));
78 	return (0);
79 }
80 
81 int
82 link(char *from, char *to)
83 {
84 	return (linkat(AT_FDCWD, from, AT_FDCWD, to, 0));
85 }
86