xref: /illumos-gate/usr/src/common/mdesc/mdesc_init_intern.c (revision e3ae4b35c024af1196582063ecee3ab79367227d)
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 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/param.h>
29 #include <sys/mdesc.h>
30 #include <sys/mdesc_impl.h>
31 
32 md_t *
33 md_init_intern(uint64_t *ptr,  void *(*allocp)(size_t),
34 	    void (*freep)(void *, size_t))
35 {
36 	md_impl_t	*mdp;
37 	int		idx;
38 	int		count;
39 	int		done;
40 	uint64_t	gen;
41 	mde_str_cookie_t root_name;
42 
43 	/*
44 	 * Very basic checkup for alignment to avoid
45 	 * bus error issues.
46 	 */
47 	if ((((uintptr_t)ptr) & 7) != 0)
48 		return (NULL);
49 
50 	mdp = (md_impl_t *)allocp(sizeof (md_impl_t));
51 
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 
64 	mdp->headerp = (md_header_t *)mdp->caddr;
65 
66 	if (mdtoh32(mdp->headerp->transport_version) != MD_TRANSPORT_VERSION) {
67 		goto cleanup_nohash;
68 	}
69 
70 	mdp->node_blk_size = mdtoh32(mdp->headerp->node_blk_sz);
71 	mdp->name_blk_size = mdtoh32(mdp->headerp->name_blk_sz);
72 	mdp->data_blk_size = mdtoh32(mdp->headerp->data_blk_sz);
73 
74 	mdp->size = MD_HEADER_SIZE + mdp->node_blk_size +
75 	    mdp->name_blk_size + mdp->data_blk_size;
76 
77 	mdp->mdep = (md_element_t *)(mdp->caddr + MD_HEADER_SIZE);
78 	mdp->namep = (char *)(mdp->caddr + MD_HEADER_SIZE + mdp->node_blk_size);
79 	mdp->datap = (uint8_t *)(mdp->caddr + MD_HEADER_SIZE +
80 	    mdp->name_blk_size + mdp->node_blk_size);
81 
82 	mdp->root_node = MDE_INVAL_ELEM_COOKIE;
83 
84 
85 	/*
86 	 * Should do a lot more sanity checking here.
87 	 */
88 
89 	/*
90 	 * Should initialize a name hash here if we intend to use one
91 	 */
92 
93 	/*
94 	 * Setup to find the root node
95 	 */
96 	root_name = md_find_name((md_t *)mdp, "root");
97 	if (root_name == MDE_INVAL_STR_COOKIE) {
98 		goto cleanup;
99 	}
100 
101 	/*
102 	 * One more property we need is the count of nodes in the
103 	 * DAG, not just the number of elements.
104 	 *
105 	 * We try and pickup the root node along the way here.
106 	 */
107 
108 	for (done = 0, idx = 0, count = 0; !done; ) {
109 		md_element_t *np;
110 
111 		np = &(mdp->mdep[idx]);
112 
113 		switch (MDE_TAG(np)) {
114 		case MDET_LIST_END:
115 			done = 1;
116 			break;
117 
118 		case MDET_NODE:
119 			if (root_name == MDE_NAME(np)) {
120 				if (mdp->root_node != MDE_INVAL_ELEM_COOKIE) {
121 					/* Gah .. more than one root */
122 					goto cleanup;
123 				}
124 				mdp->root_node = (mde_cookie_t)idx;
125 			}
126 			idx = MDE_PROP_INDEX(np);
127 			count++;
128 			break;
129 
130 		default:
131 			idx++;	/* ignore */
132 		}
133 	}
134 
135 	/*
136 	 * Ensure there is a root node
137 	 */
138 	if (mdp->root_node == MDE_INVAL_ELEM_COOKIE) {
139 		goto cleanup;
140 	}
141 
142 	/*
143 	 * Register the counts
144 	 */
145 
146 	mdp->element_count = idx + 1;	/* include LIST_END */
147 	mdp->node_count = count;
148 
149 	/*
150 	 * Final sanity check that everything adds up
151 	 */
152 	if (mdp->element_count != (mdp->node_blk_size / MD_ELEMENT_SIZE))
153 		goto cleanup;
154 
155 	mdp->md_magic = LIBMD_MAGIC;
156 
157 	/*
158 	 * Setup MD generation
159 	 */
160 	if (md_get_prop_val((md_t *)mdp, mdp->root_node,
161 	    "md-generation#", &gen) != 0)
162 		mdp->gen = MDESC_INVAL_GEN;
163 	else
164 		mdp->gen = gen;
165 
166 	return ((md_t *)mdp);
167 
168 cleanup:
169 	/*
170 	 * Clean up here - including a name hash if
171 	 * we build one.
172 	 */
173 
174 cleanup_nohash:
175 	mdp->freep(mdp, sizeof (md_impl_t));
176 	return (NULL);
177 }
178