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/pathname.h>
41#include <sys/vfs.h>
42#include <sys/vnode.h>
43#include <sys/file.h>
44#include <sys/fcntl.h>
45#include <sys/proc.h>
46#include <sys/uio.h>
47#include <sys/debug.h>
48#include <c2/audit.h>
49#include <fs/fs_subr.h>
50
51/*
52 * Create a symbolic link.  Similar to link or rename except target
53 * name is passed as string argument, not converted to vnode reference.
54 */
55int
56symlinkat(char *target, int dfd, char *linkname)
57{
58	vnode_t *startvp;
59	vnode_t *dvp;
60	struct vattr vattr;
61	struct pathname lpn;
62	char *tbuf;
63	size_t tlen;
64	int error;
65	int estale_retry = 0;
66	int auditing = AU_AUDITING();
67
68	if (linkname == NULL)
69		return (set_errno(EFAULT));
70	if ((error = fgetstartvp(dfd, linkname, &startvp)) != 0)
71		return (set_errno(error));
72
73top:
74	if (error = pn_get(linkname, UIO_USERSPACE, &lpn))
75		goto out;
76	if (auditing && startvp != NULL)
77		audit_setfsat_path(2);
78	if (error = lookuppnat(&lpn, NULL, NO_FOLLOW, &dvp, NULLVPP, startvp)) {
79		pn_free(&lpn);
80		if (error == ESTALE && fs_need_estale_retry(estale_retry++))
81			goto top;
82		goto out;
83	}
84	if (vn_is_readonly(dvp))
85		error = EROFS;
86	else if (pn_fixslash(&lpn))
87		error = ENOTDIR;
88	else {
89		tbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
90		if ((error = copyinstr(target, tbuf, MAXPATHLEN, &tlen)) == 0) {
91			vattr.va_type = VLNK;
92			vattr.va_mode = 0777;
93			vattr.va_mask = AT_TYPE|AT_MODE;
94			error = VOP_SYMLINK(dvp, lpn.pn_path, &vattr,
95			    tbuf, CRED(), NULL, 0);
96			if (auditing)
97				audit_symlink_create(dvp, lpn.pn_path,
98				    tbuf, error);
99		}
100		kmem_free(tbuf, MAXPATHLEN);
101	}
102	pn_free(&lpn);
103	VN_RELE(dvp);
104	if (error == ESTALE && fs_need_estale_retry(estale_retry++))
105		goto top;
106out:
107	if (startvp != NULL)
108		VN_RELE(startvp);
109	if (error)
110		return (set_errno(error));
111	return (0);
112}
113
114int
115symlink(char *target, char *linkname)
116{
117	return (symlinkat(target, AT_FDCWD, linkname));
118}
119