cmd/auditd/queue.c

	queue.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

#include <pthread.h>
#include <memory.h>
#include "queue.h"
#include <stdio.h>
#include <assert.h>
#include "plugin.h"

#define DEBUG   0

#if DEBUG
static FILE *dbfp;
extern FILE *__auditd_debug_file_open();
#define DPRINT(x) {(void) fprintf x; }
#else
#define DPRINT(x)
#endif

void
audit_queue_init(au_queue_t *q)
{
    q->auq_head = NULL;
    q->auq_tail = NULL;
    (void) pthread_mutex_init(&q->auq_lock, NULL);
    q->auq_count = 0;
#if DEBUG
    dbfp = __auditd_debug_file_open();
#endif
}

/*
 * enqueue()    caller creates queue entry
 */

void
audit_enqueue(au_queue_t *q,  void *p)
{
    (void) pthread_mutex_lock(&q->auq_lock);

    DPRINT((dbfp, "enqueue0(%X): p=%X, head=%X, tail=%X, count=%d\n",
        q, p, q->auq_head, q->auq_tail, q->auq_count));

    if (q->auq_head == NULL)
        q->auq_head = p;
    else {
        DPRINT((dbfp, "\tindirect tail=%X\n",
            &(((audit_link_t *)(q->auq_tail))->aln_next)));

        ((audit_link_t *)(q->auq_tail))->aln_next = p;
    }
    q->auq_tail = p;
    ((audit_link_t *)p)->aln_next = NULL;
    q->auq_count++;

    DPRINT((dbfp, "enqueue1(%X): p=%X, head=%X, tail=%X, "
        "count=%d, pnext=%X\n",
        q, p, q->auq_head, q->auq_tail, q->auq_count,
        ((audit_link_t *)p)->aln_next));

    (void) pthread_mutex_unlock(&q->auq_lock);
}

/*
 * audit_dequeue() returns entry; caller is responsible for free
 */

int
audit_dequeue(au_queue_t *q, void **p)
{
    (void) pthread_mutex_lock(&q->auq_lock);

    if ((*p = q->auq_head) == NULL) {
        DPRINT((dbfp, "dequeue1(%X): p=%X, head=%X, "
            "tail=%X, count=%d\n",
            q, *p, q->auq_head, q->auq_tail, q->auq_count));

        (void) pthread_mutex_unlock(&q->auq_lock);
        return (1);
    }
    q->auq_count--;

    /* if *p is the last, next is NULL */
    q->auq_head = ((audit_link_t *)*p)->aln_next;

    DPRINT((dbfp, "dequeue0(%X): p=%X, head=%X, tail=%X, "
        "count=%d, pnext=%X\n",
        q, *p, q->auq_head, q->auq_tail, q->auq_count,
        ((audit_link_t *)*p)->aln_next));

    (void) pthread_mutex_unlock(&q->auq_lock);
    return (0);
}

/*
 * increment ref count
 */
void
audit_incr_ref(pthread_mutex_t *l, audit_rec_t *p)
{
    (void) pthread_mutex_lock(l);
    p->abq_ref_count++;
    DPRINT((dbfp, "incr_ref: p=%X, count=%d\n",
        p, p->abq_ref_count));
    (void) pthread_mutex_unlock(l);
}
/*
 * decrement reference count; if it reaches zero,
 * return a pointer to it.  Otherwise, return NULL.
 */
audit_rec_t *
audit_release(pthread_mutex_t *l, audit_rec_t *p)
{
    assert(p != NULL);

    (void) pthread_mutex_lock(l);

    DPRINT((dbfp, "release: p=%X, count=%d\n",
        p, p->abq_ref_count));

    if (--(p->abq_ref_count) > 0) {
        (void) pthread_mutex_unlock(l);
        return (NULL);
    }
    (void) pthread_mutex_unlock(l);

    return (p);
}

int
audit_queue_size(au_queue_t *q)
{
    int size;

    (void) pthread_mutex_lock(&q->auq_lock);
    size = q->auq_count;
    (void) pthread_mutex_unlock(&q->auq_lock);

    return (size);
}


void
audit_queue_destroy(au_queue_t *q)
{
    (void) pthread_mutex_destroy(&q->auq_lock);
}