xref: /titanic_41/usr/src/cmd/auditd/queue.c (revision fa9e4066f08beec538e775443c5be79dd423fcab)
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 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <pthread.h>
29 #include <memory.h>
30 #include "queue.h"
31 #include <stdio.h>
32 #include <assert.h>
33 #include "plugin.h"
34 
35 #define	DEBUG	0
36 
37 #if DEBUG
38 static FILE *dbfp;
39 extern FILE *__auditd_debug_file_open();
40 #define	DPRINT(x) {(void) fprintf x; }
41 #else
42 #define	DPRINT(x)
43 #endif
44 
45 void
46 audit_queue_init(au_queue_t *q)
47 {
48 	q->auq_head = NULL;
49 	q->auq_tail = NULL;
50 	(void) pthread_mutex_init(&q->auq_lock, NULL);
51 	q->auq_count = 0;
52 #if DEBUG
53 	dbfp = __auditd_debug_file_open();
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(%X): p=%X, head=%X, tail=%X, count=%d\n",
67 	    q, p, q->auq_head, q->auq_tail, q->auq_count));
68 
69 	if (q->auq_head == NULL)
70 		q->auq_head = p;
71 	else {
72 		DPRINT((dbfp, "\tindirect tail=%X\n",
73 		    &(((audit_link_t *)(q->auq_tail))->aln_next)));
74 
75 		((audit_link_t *)(q->auq_tail))->aln_next = p;
76 	}
77 	q->auq_tail = p;
78 	((audit_link_t *)p)->aln_next = NULL;
79 	q->auq_count++;
80 
81 	DPRINT((dbfp, "enqueue1(%X): p=%X, head=%X, tail=%X, "
82 	    "count=%d, pnext=%X\n",
83 	    q, p, q->auq_head, q->auq_tail, q->auq_count,
84 	    ((audit_link_t *)p)->aln_next));
85 
86 	(void) pthread_mutex_unlock(&q->auq_lock);
87 }
88 
89 /*
90  * audit_dequeue() returns entry; caller is responsible for free
91  */
92 
93 int
94 audit_dequeue(au_queue_t *q, void **p)
95 {
96 	(void) pthread_mutex_lock(&q->auq_lock);
97 
98 	if ((*p = q->auq_head) == NULL) {
99 		DPRINT((dbfp, "dequeue1(%X): p=%X, head=%X, "
100 		    "tail=%X, count=%d\n",
101 		    q, *p, q->auq_head, q->auq_tail, q->auq_count));
102 
103 		(void) pthread_mutex_unlock(&q->auq_lock);
104 		return (1);
105 	}
106 	q->auq_count--;
107 
108 	/* if *p is the last, next is NULL */
109 	q->auq_head = ((audit_link_t *)*p)->aln_next;
110 
111 	DPRINT((dbfp, "dequeue0(%X): p=%X, head=%X, tail=%X, "
112 	    "count=%d, pnext=%X\n",
113 	    q, *p, q->auq_head, q->auq_tail, q->auq_count,
114 	    ((audit_link_t *)*p)->aln_next));
115 
116 	(void) pthread_mutex_unlock(&q->auq_lock);
117 	return (0);
118 }
119 
120 /*
121  * increment ref count
122  */
123 void
124 audit_incr_ref(pthread_mutex_t *l, audit_rec_t *p)
125 {
126 	(void) pthread_mutex_lock(l);
127 	p->abq_ref_count++;
128 	DPRINT((dbfp, "incr_ref: p=%X, count=%d\n",
129 	    p, p->abq_ref_count));
130 	(void) pthread_mutex_unlock(l);
131 }
132 /*
133  * decrement reference count; if it reaches zero,
134  * return a pointer to it.  Otherwise, return NULL.
135  */
136 audit_rec_t *
137 audit_release(pthread_mutex_t *l, audit_rec_t *p)
138 {
139 	assert(p != NULL);
140 
141 	(void) pthread_mutex_lock(l);
142 
143 	DPRINT((dbfp, "release: p=%X, count=%d\n",
144 	    p, p->abq_ref_count));
145 
146 	if (--(p->abq_ref_count) > 0) {
147 		(void) pthread_mutex_unlock(l);
148 		return (NULL);
149 	}
150 	(void) pthread_mutex_unlock(l);
151 
152 	return (p);
153 }
154 
155 int
156 audit_queue_size(au_queue_t *q)
157 {
158 	int	size;
159 
160 	(void) pthread_mutex_lock(&q->auq_lock);
161 	size = q->auq_count;
162 	(void) pthread_mutex_unlock(&q->auq_lock);
163 
164 	return (size);
165 }
166 
167 
168 void
169 audit_queue_destroy(au_queue_t *q)
170 {
171 	(void) pthread_mutex_destroy(&q->auq_lock);
172 }
173