usr/src/cmd/auditd/queue.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  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <pthread.h>
  27 #include <memory.h>
  28 #include "queue.h"
  29 #include <stdio.h>
  30 #include <assert.h>
  31 #include "plugin.h"
  32
  33 #define DEBUG   0
  34
  35 #if DEBUG
  36 extern FILE *dbfp;
  37 extern FILE *__auditd_debug_file_open();
  38 #define DPRINT(x) { (void) fprintf x; }
  39 #else
  40 #define DPRINT(x)
  41 #endif
  42
  43 void
  44 audit_queue_init(au_queue_t *q)
  45 {
  46         q->auq_head = NULL;
  47         q->auq_tail = NULL;
  48         (void) pthread_mutex_init(&q->auq_lock, NULL);
  49         q->auq_count = 0;
  50 #if DEBUG
  51         if (dbfp == NULL) {
  52                 dbfp = __auditd_debug_file_open();
  53         }
  54 #endif
  55 }
  56
  57 /*
  58  * enqueue()    caller creates queue entry
  59  */
  60
  61 void
  62 audit_enqueue(au_queue_t *q,  void *p)
  63 {
  64         (void) pthread_mutex_lock(&q->auq_lock);
  65
  66         DPRINT((dbfp, "enqueue0(%p): p=%p, head=%p, tail=%p, count=%d\n",
  67             (void *)q, (void *)p, (void *)q->auq_head, (void *)q->auq_tail,
  68             q->auq_count));
  69
  70         if (q->auq_head == NULL)
  71                 q->auq_head = p;
  72         else {
  73                 DPRINT((dbfp, "\tindirect tail=%p\n",
  74                     (void *)&(((audit_link_t *)(q->auq_tail))->aln_next)));
  75
  76                 ((audit_link_t *)(q->auq_tail))->aln_next = p;
  77         }
  78         q->auq_tail = p;
  79         ((audit_link_t *)p)->aln_next = NULL;
  80         q->auq_count++;
  81
  82         DPRINT((dbfp, "enqueue1(%p): p=%p, head=%p, tail=%p, "
  83             "count=%d, pnext=%p\n", (void *)q, (void *)p, (void *)q->auq_head,
  84             (void *)q->auq_tail, q->auq_count,
  85             (void *)((audit_link_t *)p)->aln_next));
  86
  87         (void) pthread_mutex_unlock(&q->auq_lock);
  88 }
  89
  90 /*
  91  * audit_dequeue() returns entry; caller is responsible for free
  92  */
  93
  94 int
  95 audit_dequeue(au_queue_t *q, void **p)
  96 {
  97         (void) pthread_mutex_lock(&q->auq_lock);
  98
  99         if ((*p = q->auq_head) == NULL) {
 100                 DPRINT((dbfp, "dequeue1(%p): p=%p, head=%p, "
 101                     "tail=%p, count=%d\n", (void *)q, (void *)*p,
 102                     (void *)q->auq_head, (void *)q->auq_tail, q->auq_count));
 103
 104                 (void) pthread_mutex_unlock(&q->auq_lock);
 105                 return (1);
 106         }
 107         q->auq_count--;
 108
 109         /* if *p is the last, next is NULL */
 110         q->auq_head = ((audit_link_t *)*p)->aln_next;
 111
 112         DPRINT((dbfp, "dequeue0(%p): p=%p, head=%p, tail=%p, "
 113             "count=%d, pnext=%p\n", (void *)q, (void *)*p, (void *)q->auq_head,
 114             (void *)q->auq_tail, q->auq_count,
 115             (void *)((audit_link_t *)*p)->aln_next));
 116
 117         (void) pthread_mutex_unlock(&q->auq_lock);
 118         return (0);
 119 }
 120
 121 /*
 122  * increment ref count
 123  */
 124 void
 125 audit_incr_ref(pthread_mutex_t *l, audit_rec_t *p)
 126 {
 127         (void) pthread_mutex_lock(l);
 128         p->abq_ref_count++;
 129         DPRINT((dbfp, "incr_ref: p=%p, count=%d\n",
 130             (void *)p, p->abq_ref_count));
 131         (void) pthread_mutex_unlock(l);
 132 }
 133 /*
 134  * decrement reference count; if it reaches zero,
 135  * return a pointer to it.  Otherwise, return NULL.
 136  */
 137 audit_rec_t *
 138 audit_release(pthread_mutex_t *l, audit_rec_t *p)
 139 {
 140         assert(p != NULL);
 141
 142         (void) pthread_mutex_lock(l);
 143
 144         DPRINT((dbfp, "release: p=%p , count=%d\n",
 145             (void *)p, p->abq_ref_count));
 146
 147         if (--(p->abq_ref_count) > 0) {
 148                 (void) pthread_mutex_unlock(l);
 149                 return (NULL);
 150         }
 151         (void) pthread_mutex_unlock(l);
 152
 153         return (p);
 154 }
 155
 156 int
 157 audit_queue_size(au_queue_t *q)
 158 {
 159         int     size;
 160
 161         (void) pthread_mutex_lock(&q->auq_lock);
 162         size = q->auq_count;
 163         (void) pthread_mutex_unlock(&q->auq_lock);
 164
 165         return (size);
 166 }
 167
 168
 169 void
 170 audit_queue_destroy(au_queue_t *q)
 171 {
 172         (void) pthread_mutex_destroy(&q->auq_lock);
 173 }