xref: /titanic_41/usr/src/uts/common/syscall/symlink.c (revision 25cf1a301a396c38e8adf52c15f537b80d2483f7)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 #pragma ident	"%Z%%M%	%I%	%E% SMI"
36 
37 #include <sys/param.h>
38 #include <sys/isa_defs.h>
39 #include <sys/types.h>
40 #include <sys/sysmacros.h>
41 #include <sys/systm.h>
42 #include <sys/errno.h>
43 #include <sys/pathname.h>
44 #include <sys/vfs.h>
45 #include <sys/vnode.h>
46 #include <sys/proc.h>
47 #include <sys/uio.h>
48 #include <sys/debug.h>
49 #include <c2/audit.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  */
55 int
56 symlink(char *target, char *linkname)
57 {
58 	vnode_t *dvp;
59 	struct vattr vattr;
60 	struct pathname lpn;
61 	char *tbuf;
62 	size_t tlen;
63 	int error;
64 
65 top:
66 	if (error = pn_get(linkname, UIO_USERSPACE, &lpn))
67 		return (set_errno(error));
68 	if (error = lookuppn(&lpn, NULL, NO_FOLLOW, &dvp, NULLVPP)) {
69 		pn_free(&lpn);
70 		if (error == ESTALE)
71 			goto top;
72 		return (set_errno(error));
73 	}
74 	if (vn_is_readonly(dvp))
75 		error = EROFS;
76 	else if (pn_fixslash(&lpn))
77 		error = ENOTDIR;
78 	else {
79 		tbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
80 		if ((error = copyinstr(target, tbuf, MAXPATHLEN, &tlen)) == 0) {
81 			vattr.va_type = VLNK;
82 			vattr.va_mode = 0777;
83 			vattr.va_mask = AT_TYPE|AT_MODE;
84 			error = VOP_SYMLINK(dvp, lpn.pn_path, &vattr,
85 				tbuf, CRED());
86 #ifdef	C2_AUDIT
87 			if (audit_active)
88 				audit_symlink_create(dvp, lpn.pn_path,
89 					tbuf, error);
90 #endif	/* C2_AUDIT */
91 		}
92 		kmem_free(tbuf, MAXPATHLEN);
93 	}
94 	pn_free(&lpn);
95 	VN_RELE(dvp);
96 	if (error) {
97 		if (error == ESTALE)
98 			goto top;
99 		return (set_errno(error));
100 	}
101 	return (0);
102 }
103