xref: /freebsd/sys/contrib/openzfs/module/zfs/pathname.c (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
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 2007 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  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 
41 #include <sys/types.h>
42 #include <sys/pathname.h>
43 #include <sys/kmem.h>
44 #include <sys/sysmacros.h>
45 
46 /*
47  * Pathname utilities.
48  *
49  * In translating file names we copy each argument file
50  * name into a pathname structure where we operate on it.
51  * Each pathname structure can hold "pn_bufsize" characters
52  * including a terminating null, and operations here support
53  * allocating and freeing pathname structures, fetching
54  * strings from user space, getting the next character from
55  * a pathname, combining two pathnames (used in symbolic
56  * link processing), and peeling off the first component
57  * of a pathname.
58  */
59 
60 /*
61  * Allocate contents of pathname structure.  Structure is typically
62  * an automatic variable in calling routine for convenience.
63  *
64  * May sleep in the call to kmem_alloc() and so must not be called
65  * from interrupt level.
66  */
67 void
pn_alloc(struct pathname * pnp)68 pn_alloc(struct pathname *pnp)
69 {
70 	pn_alloc_sz(pnp, MAXPATHLEN);
71 }
72 void
pn_alloc_sz(struct pathname * pnp,size_t sz)73 pn_alloc_sz(struct pathname *pnp, size_t sz)
74 {
75 	pnp->pn_buf = kmem_alloc(sz, KM_SLEEP);
76 	pnp->pn_bufsize = sz;
77 }
78 
79 /*
80  * Free pathname resources.
81  */
82 void
pn_free(struct pathname * pnp)83 pn_free(struct pathname *pnp)
84 {
85 	/* pn_bufsize is usually MAXPATHLEN, but may not be */
86 	kmem_free(pnp->pn_buf, pnp->pn_bufsize);
87 	pnp->pn_buf = NULL;
88 	pnp->pn_bufsize = 0;
89 }
90