xref: /illumos-gate/usr/src/common/mdesc/mdesc_init_intern.c (revision 814a60b13c0ad90e5d2edfd29a7a84bbf416cc1a)
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 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/mdesc.h>
32 #include <sys/mdesc_impl.h>
33 
34 md_t *
35 md_init_intern(uint64_t *ptr, void *(*allocp)(size_t),
36 			void (*freep)(void *, size_t))
37 {
38 	md_impl_t	*mdp;
39 	int		idx;
40 	int		count;
41 	int		done;
42 	mde_str_cookie_t root_name;
43 
44 	/*
45 	 * Very basic checkup for alignment to avoid
46 	 * bus error issues.
47 	 */
48 	if ((((uint64_t)ptr)&7) != 0)
49 		return (NULL);
50 
51 	mdp = (md_impl_t *)allocp(sizeof (md_impl_t));
52 	if (mdp == NULL)
53 		return (NULL);
54 
55 	mdp->allocp = allocp;
56 	mdp->freep = freep;
57 
58 	mdp->caddr = (char *)ptr;
59 
60 	/*
61 	 * setup internal structures
62 	 */
63 	mdp->headerp = (md_header_t *)mdp->caddr;
64 
65 	if (mdtoh32(mdp->headerp->transport_version) != MD_TRANSPORT_VERSION) {
66 		goto cleanup_nohash;
67 	}
68 
69 	mdp->node_blk_size = mdtoh32(mdp->headerp->node_blk_sz);
70 	mdp->name_blk_size = mdtoh32(mdp->headerp->name_blk_sz);
71 	mdp->data_blk_size = mdtoh32(mdp->headerp->data_blk_sz);
72 
73 	mdp->size = MD_HEADER_SIZE+mdp->node_blk_size+
74 	    mdp->name_blk_size+mdp->data_blk_size;
75 
76 	mdp->mdep = (md_element_t *)(mdp->caddr+MD_HEADER_SIZE);
77 	mdp->namep = (char *)(mdp->caddr+MD_HEADER_SIZE+mdp->node_blk_size);
78 	mdp->datap = (uint8_t *)(mdp->caddr+MD_HEADER_SIZE+mdp->name_blk_size+
79 	    mdp->node_blk_size);
80 
81 	mdp->root_node = MDE_INVAL_ELEM_COOKIE;
82 
83 
84 	/*
85 	 * Should do a lot more sanity checking here.
86 	 */
87 
88 	/*
89 	 * Should initialize a name hash here if we intend to use one
90 	 */
91 
92 	/*
93 	 * Setup to find the root node
94 	 */
95 	root_name = md_find_name((md_t *)mdp, "root");
96 	if (root_name == MDE_INVAL_STR_COOKIE) {
97 		goto cleanup;
98 	}
99 
100 	/*
101 	 * One more property we need is the count of nodes in the
102 	 * DAG, not just the number of elements.
103 	 *
104 	 * We try and pickup the root node along the way here.
105 	 */
106 
107 	for (done = 0, idx = 0, count = 0; !done; ) {
108 		md_element_t *np;
109 
110 		np = &(mdp->mdep[idx]);
111 
112 		switch (MDE_TAG(np)) {
113 		case MDET_LIST_END:
114 			done = 1;
115 			break;
116 
117 		case MDET_NODE:
118 			if (root_name == MDE_NAME(np)) {
119 				if (mdp->root_node != MDE_INVAL_ELEM_COOKIE) {
120 					/* Gah .. more than one root */
121 					goto cleanup;
122 				}
123 				mdp->root_node = (mde_cookie_t)idx;
124 			}
125 			idx = MDE_PROP_INDEX(np);
126 			count ++;
127 			break;
128 
129 		default:
130 			idx++;	/* ignore */
131 		}
132 	}
133 
134 	/*
135 	 * Ensure there is a root node
136 	 */
137 	if (mdp->root_node == MDE_INVAL_ELEM_COOKIE) {
138 		goto cleanup;
139 	}
140 
141 	/*
142 	 * Register the counts
143 	 */
144 
145 	mdp->element_count = idx+1;	/* include LIST_END */
146 	mdp->node_count = count;
147 
148 	/*
149 	 * Final sanity check that everything adds up
150 	 */
151 	if (mdp->element_count != (mdp->node_blk_size/MD_ELEMENT_SIZE))
152 		goto cleanup;
153 
154 	mdp->md_magic = LIBMD_MAGIC;
155 
156 	return ((md_t *)mdp);
157 
158 cleanup:;
159 	/*
160 	 * Clean up here - including a name hash if
161 	 * we build one.
162 	 */
163 cleanup_nohash:;
164 	mdp->freep(mdp, sizeof (md_impl_t));
165 	return (NULL);
166 }
167