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 */
55 int
symlinkat(char * target,int dfd,char * linkname)56 symlinkat(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
73 top:
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;
106 out:
107 if (startvp != NULL)
108 VN_RELE(startvp);
109 if (error)
110 return (set_errno(error));
111 return (0);
112 }
113
114 int
symlink(char * target,char * linkname)115 symlink(char *target, char *linkname)
116 {
117 return (symlinkat(target, AT_FDCWD, linkname));
118 }
119