xref: /titanic_41/usr/src/uts/common/syscall/symlink.c (revision 3fb517f786391b507780c78aabb8d98bfea9efe9)
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 2010 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 #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/proc.h>
44 #include <sys/uio.h>
45 #include <sys/debug.h>
46 #include <c2/audit.h>
47 #include <fs/fs_subr.h>
48 
49 /*
50  * Create a symbolic link.  Similar to link or rename except target
51  * name is passed as string argument, not converted to vnode reference.
52  */
53 int
54 symlink(char *target, char *linkname)
55 {
56 	vnode_t *dvp;
57 	struct vattr vattr;
58 	struct pathname lpn;
59 	char *tbuf;
60 	size_t tlen;
61 	int error;
62 	int estale_retry = 0;
63 
64 top:
65 	if (error = pn_get(linkname, UIO_USERSPACE, &lpn))
66 		return (set_errno(error));
67 	if (error = lookuppn(&lpn, NULL, NO_FOLLOW, &dvp, NULLVPP)) {
68 		pn_free(&lpn);
69 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
70 			goto top;
71 		return (set_errno(error));
72 	}
73 	if (vn_is_readonly(dvp))
74 		error = EROFS;
75 	else if (pn_fixslash(&lpn))
76 		error = ENOTDIR;
77 	else {
78 		tbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
79 		if ((error = copyinstr(target, tbuf, MAXPATHLEN, &tlen)) == 0) {
80 			vattr.va_type = VLNK;
81 			vattr.va_mode = 0777;
82 			vattr.va_mask = AT_TYPE|AT_MODE;
83 			error = VOP_SYMLINK(dvp, lpn.pn_path, &vattr,
84 			    tbuf, CRED(), NULL, 0);
85 			if (AU_AUDITING())
86 				audit_symlink_create(dvp, lpn.pn_path,
87 				    tbuf, error);
88 		}
89 		kmem_free(tbuf, MAXPATHLEN);
90 	}
91 	pn_free(&lpn);
92 	VN_RELE(dvp);
93 	if (error) {
94 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
95 			goto top;
96 		return (set_errno(error));
97 	}
98 	return (0);
99 }
100