usr/src/common/ctf/ctf_util.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, 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 <ctf_impl.h>
  30
  31 /*
  32  * Simple doubly-linked list append routine.  This implementation assumes that
  33  * each list element contains an embedded ctf_list_t as the first member.
  34  * An additional ctf_list_t is used to store the head (l_next) and tail
  35  * (l_prev) pointers.  The current head and tail list elements have their
  36  * previous and next pointers set to NULL, respectively.
  37  */
  38 void
  39 ctf_list_append(ctf_list_t *lp, void *new)
  40 {
  41         ctf_list_t *p = lp->l_prev;     /* p = tail list element */
  42         ctf_list_t *q = new;            /* q = new list element */
  43
  44         lp->l_prev = q;
  45         q->l_prev = p;
  46         q->l_next = NULL;
  47
  48         if (p != NULL)
  49                 p->l_next = q;
  50         else
  51                 lp->l_next = q;
  52 }
  53
  54 /*
  55  * Prepend the specified existing element to the given ctf_list_t.  The
  56  * existing pointer should be pointing at a struct with embedded ctf_list_t.
  57  */
  58 void
  59 ctf_list_prepend(ctf_list_t *lp, void *new)
  60 {
  61         ctf_list_t *p = new;            /* p = new list element */
  62         ctf_list_t *q = lp->l_next;     /* q = head list element */
  63
  64         lp->l_next = p;
  65         p->l_prev = NULL;
  66         p->l_next = q;
  67
  68         if (q != NULL)
  69                 q->l_prev = p;
  70         else
  71                 lp->l_prev = p;
  72 }
  73
  74 /*
  75  * Delete the specified existing element from the given ctf_list_t.  The
  76  * existing pointer should be pointing at a struct with embedded ctf_list_t.
  77  */
  78 void
  79 ctf_list_delete(ctf_list_t *lp, void *existing)
  80 {
  81         ctf_list_t *p = existing;
  82
  83         if (p->l_prev != NULL)
  84                 p->l_prev->l_next = p->l_next;
  85         else
  86                 lp->l_next = p->l_next;
  87
  88         if (p->l_next != NULL)
  89                 p->l_next->l_prev = p->l_prev;
  90         else
  91                 lp->l_prev = p->l_prev;
  92 }
  93
  94 /*
  95  * Convert an encoded CTF string name into a pointer to a C string by looking
  96  * up the appropriate string table buffer and then adding the offset.
  97  */
  98 const char *
  99 ctf_strraw(ctf_file_t *fp, uint_t name)
 100 {
 101         ctf_strs_t *ctsp = &fp->ctf_str[CTF_NAME_STID(name)];
 102
 103         if (ctsp->cts_strs != NULL && CTF_NAME_OFFSET(name) < ctsp->cts_len)
 104                 return (ctsp->cts_strs + CTF_NAME_OFFSET(name));
 105
 106         /* string table not loaded or corrupt offset */
 107         return (NULL);
 108 }
 109
 110 const char *
 111 ctf_strptr(ctf_file_t *fp, uint_t name)
 112 {
 113         const char *s = ctf_strraw(fp, name);
 114         return (s != NULL ? s : "(?)");
 115 }
 116
 117 /*
 118  * Same strdup(3C), but use ctf_alloc() to do the memory allocation.
 119  */
 120 char *
 121 ctf_strdup(const char *s1)
 122 {
 123         char *s2 = ctf_alloc(strlen(s1) + 1);
 124
 125         if (s2 != NULL)
 126                 (void) strcpy(s2, s1);
 127
 128         return (s2);
 129 }
 130
 131 /*
 132  * Store the specified error code into errp if it is non-NULL, and then
 133  * return NULL for the benefit of the caller.
 134  */
 135 ctf_file_t *
 136 ctf_set_open_errno(int *errp, int error)
 137 {
 138         if (errp != NULL)
 139                 *errp = error;
 140         return (NULL);
 141 }
 142
 143 /*
 144  * Store the specified error code into the CTF container, and then return
 145  * CTF_ERR for the benefit of the caller.
 146  */
 147 long
 148 ctf_set_errno(ctf_file_t *fp, int err)
 149 {
 150         fp->ctf_errno = err;
 151         return (CTF_ERR);
 152 }