usr/src/common/mdesc/mdesc_init_intern.c

   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 #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         uint64_t        gen;
  43         mde_str_cookie_t root_name;
  44
  45         /*
  46          * Very basic checkup for alignment to avoid
  47          * bus error issues.
  48          */
  49         if ((((uintptr_t)ptr) & 7) != 0)
  50                 return (NULL);
  51
  52         mdp = (md_impl_t *)allocp(sizeof (md_impl_t));
  53
  54         if (mdp == NULL)
  55                 return (NULL);
  56
  57         mdp->allocp = allocp;
  58         mdp->freep = freep;
  59
  60         mdp->caddr = (char *)ptr;
  61
  62         /*
  63          * setup internal structures
  64          */
  65
  66         mdp->headerp = (md_header_t *)mdp->caddr;
  67
  68         if (mdtoh32(mdp->headerp->transport_version) != MD_TRANSPORT_VERSION) {
  69                 goto cleanup_nohash;
  70         }
  71
  72         mdp->node_blk_size = mdtoh32(mdp->headerp->node_blk_sz);
  73         mdp->name_blk_size = mdtoh32(mdp->headerp->name_blk_sz);
  74         mdp->data_blk_size = mdtoh32(mdp->headerp->data_blk_sz);
  75
  76         mdp->size = MD_HEADER_SIZE + mdp->node_blk_size +
  77             mdp->name_blk_size + mdp->data_blk_size;
  78
  79         mdp->mdep = (md_element_t *)(mdp->caddr + MD_HEADER_SIZE);
  80         mdp->namep = (char *)(mdp->caddr + MD_HEADER_SIZE + mdp->node_blk_size);
  81         mdp->datap = (uint8_t *)(mdp->caddr + MD_HEADER_SIZE +
  82             mdp->name_blk_size + mdp->node_blk_size);
  83
  84         mdp->root_node = MDE_INVAL_ELEM_COOKIE;
  85
  86
  87         /*
  88          * Should do a lot more sanity checking here.
  89          */
  90
  91         /*
  92          * Should initialize a name hash here if we intend to use one
  93          */
  94
  95         /*
  96          * Setup to find the root node
  97          */
  98         root_name = md_find_name((md_t *)mdp, "root");
  99         if (root_name == MDE_INVAL_STR_COOKIE) {
 100                 goto cleanup;
 101         }
 102
 103         /*
 104          * One more property we need is the count of nodes in the
 105          * DAG, not just the number of elements.
 106          *
 107          * We try and pickup the root node along the way here.
 108          */
 109
 110         for (done = 0, idx = 0, count = 0; !done; ) {
 111                 md_element_t *np;
 112
 113                 np = &(mdp->mdep[idx]);
 114
 115                 switch (MDE_TAG(np)) {
 116                 case MDET_LIST_END:
 117                         done = 1;
 118                         break;
 119
 120                 case MDET_NODE:
 121                         if (root_name == MDE_NAME(np)) {
 122                                 if (mdp->root_node != MDE_INVAL_ELEM_COOKIE) {
 123                                         /* Gah .. more than one root */
 124                                         goto cleanup;
 125                                 }
 126                                 mdp->root_node = (mde_cookie_t)idx;
 127                         }
 128                         idx = MDE_PROP_INDEX(np);
 129                         count++;
 130                         break;
 131
 132                 default:
 133                         idx++;  /* ignore */
 134                 }
 135         }
 136
 137         /*
 138          * Ensure there is a root node
 139          */
 140         if (mdp->root_node == MDE_INVAL_ELEM_COOKIE) {
 141                 goto cleanup;
 142         }
 143
 144         /*
 145          * Register the counts
 146          */
 147
 148         mdp->element_count = idx + 1;   /* include LIST_END */
 149         mdp->node_count = count;
 150
 151         /*
 152          * Final sanity check that everything adds up
 153          */
 154         if (mdp->element_count != (mdp->node_blk_size / MD_ELEMENT_SIZE))
 155                 goto cleanup;
 156
 157         mdp->md_magic = LIBMD_MAGIC;
 158
 159         /*
 160          * Setup MD generation
 161          */
 162         if (md_get_prop_val((md_t *)mdp, mdp->root_node,
 163             "md-generation#", &gen) != 0)
 164                 mdp->gen = MDESC_INVAL_GEN;
 165         else
 166                 mdp->gen = gen;
 167
 168         return ((md_t *)mdp);
 169
 170 cleanup:
 171         /*
 172          * Clean up here - including a name hash if
 173          * we build one.
 174          */
 175
 176 cleanup_nohash:
 177         mdp->freep(mdp, sizeof (md_impl_t));
 178         return (NULL);
 179 }