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 2008 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_walk_dag(md_impl_t *, mde_cookie_t, mde_cookie_t, mde_str_cookie_t,
43 mde_str_cookie_t, uint8_t *, md_walk_fn_t, void *, int);
44
45
46 /*
47 * Walk the machine description directed graph from a starting
48 * node searching for nodes of a given node name and using a
49 * given arc type. Call a callback function for each node found.
50 * Each node will be visited only once.
51 *
52 * Input Description
53 * ------------------- ----------------------------------------
54 * md_t * Pointer to md session
55 * mde_cookie_t Index of the starting node
56 * mde_str_cookie_t Node name cookie of the nodes to call
57 * the walk function
58 * mde_str_cookie_t Arc name cookie of the path to follow
59 * md_walk_fn_t The function to call for each node
60 * void * Private data to pass to the walker function
61 *
62 */
63 int
md_walk_dag(md_t * ptr,mde_cookie_t startnode,mde_str_cookie_t node_name_cookie,mde_str_cookie_t arc_name_cookie,md_walk_fn_t func,void * private)64 md_walk_dag(md_t *ptr, mde_cookie_t startnode,
65 mde_str_cookie_t node_name_cookie, mde_str_cookie_t arc_name_cookie,
66 md_walk_fn_t func, void *private)
67 {
68 int res;
69 uint8_t *seenp;
70 md_impl_t *mdp;
71 mde_cookie_t start;
72
73 mdp = (md_impl_t *)ptr;
74 if (mdp == NULL) {
75 return (-1);
76 }
77
78 /*
79 * Possible the caller was lazy and didn't check the
80 * validitiy of either the node name or the arc name
81 * on calling ... in which case fail to find any
82 * nodes.
83 * This is distinct, from a fail (-1) since we return
84 * that nothing was found.
85 */
86 if (node_name_cookie == MDE_INVAL_STR_COOKIE ||
87 arc_name_cookie == MDE_INVAL_STR_COOKIE) {
88 return (0);
89 }
90
91 /*
92 * if we want to start at the top, start at index 0
93 */
94 start = startnode;
95 if (start == MDE_INVAL_ELEM_COOKIE) {
96 start = 0;
97 }
98
99 /*
100 * Scan from the start point until the first node.
101 */
102 while (start < mdp->element_count &&
103 MDE_TAG(&mdp->mdep[start]) == MDET_NULL) {
104 start++;
105 }
106
107 /*
108 * This was a bogus start point if no node found
109 */
110 if (MDE_TAG(&mdp->mdep[start]) != MDET_NODE) {
111 return (-1); /* illegal start node specified */
112 }
113
114 /*
115 * Allocate a recursion detection structure so we only visit
116 * each node once.
117 */
118 seenp = (uint8_t *)mdp->allocp(mdp->element_count);
119 if (seenp == NULL) {
120 return (-1);
121 }
122 (void) memset(seenp, 0, mdp->element_count);
123
124 /*
125 * Now build the list of requested nodes.
126 */
127 res = mdl_walk_dag(mdp, MDE_INVAL_ELEM_COOKIE, start,
128 node_name_cookie, arc_name_cookie, seenp, func, private, 0);
129
130 mdp->freep(seenp, mdp->element_count);
131
132 return (res >= 0 ? 0 : res);
133 }
134
135
136 static int
mdl_walk_dag(md_impl_t * mdp,mde_cookie_t parentidx,mde_cookie_t nodeidx,mde_str_cookie_t node_name_cookie,mde_str_cookie_t arc_name_cookie,uint8_t * seenp,md_walk_fn_t func,void * private,int level)137 mdl_walk_dag(md_impl_t *mdp, mde_cookie_t parentidx, mde_cookie_t nodeidx,
138 mde_str_cookie_t node_name_cookie, mde_str_cookie_t arc_name_cookie,
139 uint8_t *seenp, md_walk_fn_t func, void *private, int level)
140 {
141 int result;
142 md_element_t *mdep;
143
144 /* Get the node element from the session */
145 mdep = &(mdp->mdep[nodeidx]);
146
147 /* see if cookie is infact a node */
148 if (MDE_TAG(mdep) != MDET_NODE) {
149 return (MDE_WALK_ERROR);
150 }
151
152 /* have we been here before ? */
153 if (seenp[nodeidx]) {
154 return (MDE_WALK_NEXT);
155 }
156 seenp[nodeidx] = 1;
157
158 #ifdef DEBUG_LIBMDESC
159 {
160 int x;
161 for (x = 0; x < level; x++) {
162 printf("-");
163 }
164 printf("%d (%s)\n", nodeidx,
165 (char *)(mdp->datap + MDE_NAME(mdep)));
166 }
167 #endif
168
169 /* is this node of the type we seek ? */
170 if (MDE_NAME(mdep) == node_name_cookie) {
171 /*
172 * Yes. Call the callback function.
173 */
174 result = (func)((md_t *)mdp, parentidx, nodeidx, private);
175 if (result != MDE_WALK_NEXT) {
176 return (result);
177 }
178 }
179
180 /*
181 * Simply walk the elements in the node.
182 * if we find a matching arc, then recursively call
183 * the subordinate looking for a match
184 */
185 result = MDE_WALK_NEXT;
186 for (mdep++; MDE_TAG(mdep) != MDET_NODE_END; mdep++) {
187 if (MDE_TAG(mdep) == MDET_PROP_ARC &&
188 MDE_NAME(mdep) == arc_name_cookie) {
189 /*
190 * The current node becomes the parent node, and the
191 * arc index is the new current node.
192 */
193 result = mdl_walk_dag(mdp, nodeidx, mdep->d.prop_idx,
194 node_name_cookie, arc_name_cookie, seenp, func,
195 private, level+1);
196 if (result != MDE_WALK_NEXT) {
197 /* The walk is complete or terminated. */
198 return (result);
199 }
200 }
201 }
202
203 return (result);
204 }
205