xref: /titanic_41/usr/src/common/mdesc/mdesc_scandag.c (revision c138f478d2bc94e73ab8f6a084e323bec25e62f5)
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 #ifdef _KERNEL
32 #include <sys/systm.h>
33 #else
34 #include <string.h>
35 #include <strings.h>
36 #endif
37 
38 #include <sys/mdesc.h>
39 #include <sys/mdesc_impl.h>
40 
41 static int
42 mdl_scan_dag(md_impl_t *mdp,
43 	int nodeidx,
44 	mde_str_cookie_t node_cookie,
45 	mde_str_cookie_t arc_cookie,
46 	uint8_t *dseenp,
47 	int *idxp,
48 	mde_cookie_t *stashp,
49 	int level);
50 
51 
52 int
53 md_scan_dag(md_t *ptr,
54 	mde_cookie_t startnode,
55 	mde_str_cookie_t node_name_cookie,
56 	mde_str_cookie_t arc_name_cookie,
57 	mde_cookie_t *stashp)
58 {
59 	int	res;
60 	int	idx;
61 	uint8_t *seenp;
62 	md_impl_t *mdp;
63 	int	start;
64 
65 	mdp = (md_impl_t *)ptr;
66 
67 	/*
68 	 * Possible the caller was lazy and didn't check the
69 	 * validitiy of either the node name or the arc name
70 	 * on calling ... in which case fail to find any
71 	 * nodes.
72 	 * This is distinct, from a fail (-1) since we return
73 	 * that nothing was found.
74 	 */
75 
76 	if (node_name_cookie == MDE_INVAL_STR_COOKIE ||
77 		arc_name_cookie == MDE_INVAL_STR_COOKIE) return 0;
78 
79 	/*
80 	 * if we want to start at the top, start at index 0
81 	 */
82 
83 	start = (int)startnode;
84 	if (start == MDE_INVAL_ELEM_COOKIE) start = 0;
85 
86 	/*
87 	 * Scan from the start point until the first node.
88 	 */
89 	while (MDE_TAG(&mdp->mdep[start]) == MDET_NULL) start++;
90 
91 	/*
92 	 * This was a bogus start point if no node found
93 	 */
94 	if (MDE_TAG(&mdp->mdep[start]) != MDET_NODE) {
95 		return (-1);	/* illegal start node specified */
96 	}
97 
98 	/*
99 	 * Allocate a recursion mask on the local stack fail
100 	 * if we can't allocate the recursion detection.
101 	 */
102 	seenp = (uint8_t *)mdp->allocp(mdp->element_count);
103 	if (seenp == NULL)
104 		return (-1);
105 	(void) memset(seenp, 0, mdp->element_count);
106 
107 	/*
108 	 * Now build the list of requested nodes.
109 	 */
110 	idx = 0;
111 	res = mdl_scan_dag(mdp, start,
112 		node_name_cookie, arc_name_cookie,
113 		seenp, &idx, stashp, 0);
114 
115 	mdp->freep(seenp, mdp->element_count);
116 
117 	return (res >= 0 ? idx : res);
118 }
119 
120 
121 
122 
123 
124 static int mdl_scan_dag(md_impl_t *mdp,
125 	int nodeidx,
126 	mde_str_cookie_t node_name_cookie,
127 	mde_str_cookie_t arc_name_cookie,
128 	uint8_t *seenp,
129 	int *idxp,
130 	mde_cookie_t *stashp,
131 	int level)
132 {
133 	md_element_t *mdep;
134 
135 	mdep = &(mdp->mdep[nodeidx]);
136 
137 	/* see if cookie is infact a node */
138 	if (MDE_TAG(mdep) != MDET_NODE)
139 		return (-1);
140 
141 	/* have we been here before ? */
142 	if (seenp[nodeidx])
143 		return (0);
144 	seenp[nodeidx] = 1;
145 
146 	/* is this node of the type we seek ? */
147 
148 #ifdef	DEBUG_LIBMDESC
149 	{
150 	int x;
151 	for (x = 0; x < level; x++)
152 		printf("-");
153 	printf("%d (%s)\n", nodeidx, (char *)(mdp->datap + MDE_NAME(mdep)));
154 	}
155 #endif
156 
157 	if (MDE_NAME(mdep) == node_name_cookie) {
158 		/* record the node in the list and keep searching */
159 		if (stashp != NULL) {
160 			stashp[*idxp] = (mde_cookie_t)nodeidx;
161 		}
162 		(*idxp)++;
163 #ifdef	DEBUG_LIBMDESC
164 		printf("\t* %d\n", *idxp);
165 #endif
166 	}
167 
168 	/*
169 	 * Simply walk the elements in the node.
170 	 * if we find a matching arc, then recursively call
171 	 * the subordinate looking for a match
172 	 */
173 
174 	for (mdep++; MDE_TAG(mdep) != MDET_NODE_END; mdep++) {
175 		if (MDE_TAG(mdep) == MDET_PROP_ARC &&
176 			MDE_NAME(mdep) == arc_name_cookie) {
177 			int res;
178 
179 			res = mdl_scan_dag(mdp,
180 			    (int)mdep->d.prop_idx,
181 			    node_name_cookie,
182 			    arc_name_cookie,
183 			    seenp, idxp, stashp, level+1);
184 
185 			if (res == -1)
186 				return (res);
187 		}
188 	}
189 
190 	return (0);
191 }
192