xref: /illumos-gate/usr/src/stand/lib/fs/nfs/pathname.c (revision f3041bfa)
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 2009 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 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/errno.h>
38 #include <st_pathname.h>
39 #include <sys/promif.h>
40 #include <sys/salib.h>
41 #include <sys/bootdebug.h>
42 
43 /*
44  * Pathname utilities.
45  *
46  * In translating file names we copy each argument file
47  * name into a pathname structure where we operate on it.
48  * Each pathname structure can hold MAXPATHLEN characters
49  * including a terminating null, and operations here support
50  * fetching strings from user space, getting the next character from
51  * a pathname, combining two pathnames (used in symbolic
52  * link processing), and peeling off the first component
53  * of a pathname.
54  */
55 
56 #define	dprintf	if (boothowto & RB_DEBUG) printf
57 
58 /*
59  * Setup contents of pathname structure. Warn about missing allocations.
60  * Structure itself is typically automatic
61  * variable in calling routine for convenience.
62  *
63  * NOTE: if buf is NULL, failure occurs.
64  */
65 int
66 stpn_alloc(struct st_pathname *pnp)
67 {
68 	if (pnp->pn_buf == NULL)
69 		return (-1);
70 	pnp->pn_path = (char *)pnp->pn_buf;
71 	pnp->pn_pathlen = 0;
72 	return (0);
73 }
74 
75 /*
76  * Pull a pathname from user user or kernel space
77  */
78 int
79 stpn_get(char *str, struct st_pathname *pnp)
80 {
81 	if (stpn_alloc(pnp) != 0)
82 		return (-1);
83 	bcopy(str, pnp->pn_path, strlen(str));
84 	pnp->pn_pathlen = strlen(str);		/* don't count null byte */
85 	return (0);
86 }
87 
88 /*
89  * Set pathname to argument string.
90  */
91 int
92 stpn_set(struct st_pathname *pnp, char *path)
93 {
94 	pnp->pn_path = pnp->pn_buf;
95 	pnp->pn_pathlen = strlen(pnp->pn_path); /* don't count null byte */
96 	bcopy(pnp->pn_path, path, pnp->pn_pathlen);
97 	return (0);
98 }
99 
100 /*
101  * Combine two argument pathnames by putting
102  * second argument before first in first's buffer,
103  * and freeing second argument.
104  * This isn't very general: it is designed specifically
105  * for symbolic link processing.
106  */
107 int
108 stpn_combine(struct st_pathname *pnp, struct st_pathname *sympnp)
109 {
110 
111 	if (pnp->pn_pathlen + sympnp->pn_pathlen >= MAXPATHLEN)
112 		return (ENAMETOOLONG);
113 	bcopy(pnp->pn_path, pnp->pn_buf + sympnp->pn_pathlen,
114 	    (uint_t)pnp->pn_pathlen);
115 	bcopy(sympnp->pn_path, pnp->pn_buf, (uint_t)sympnp->pn_pathlen);
116 	pnp->pn_pathlen += sympnp->pn_pathlen;
117 	pnp->pn_buf[pnp->pn_pathlen] = '\0';
118 	pnp->pn_path = pnp->pn_buf;
119 	return (0);
120 }
121 
122 /*
123  * Get next component off a pathname and leave in
124  * buffer comoponent which should have room for
125  * NFS_MAXNAMLEN (1024) bytes and a null terminator character.
126  * If PEEK is set in flags, just peek at the component,
127  * i.e., don't strip it out of pnp.
128  */
129 int
130 stpn_getcomponent(struct st_pathname *pnp, char *component, int flags)
131 {
132 	char *cp;
133 	int l;
134 	int n;
135 
136 	cp = pnp->pn_path;
137 	l = pnp->pn_pathlen;
138 	n = 1024;
139 	while ((l > 0) && (*cp != '/')) {
140 		if (--n < 0)
141 			return (ENAMETOOLONG);
142 		*component++ = *cp++;
143 		--l;
144 	}
145 	if (!(flags & PN_PEEK)) {
146 		pnp->pn_path = cp;
147 		pnp->pn_pathlen = l;
148 	}
149 	*component = 0;
150 	return (0);
151 }
152 
153 /*
154  * skip over consecutive slashes in the pathname
155  */
156 void
157 stpn_skipslash(struct st_pathname *pnp)
158 {
159 	while ((pnp->pn_pathlen != 0) && (*pnp->pn_path == '/')) {
160 		pnp->pn_path++;
161 		pnp->pn_pathlen--;
162 	}
163 }
164 
165 /*
166  * free pathname resources. This is a nop - the user of these
167  * routines is responsible for allocating and freeing their memory.
168  */
169 /*ARGSUSED*/
170 void
171 stpn_free(struct st_pathname *pnp)
172 {
173 	/* nop */
174 	dprintf("pn_free(): you shouldn't be calling pn_free()!\n");
175 }
176