2 * Copyright (c) 2005 Wayne J. Salamon
5 * This software was developed by Wayne Salamon for the TrustedBSD Project.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
36 #include <sys/queue.h>
37 #include <sys/systm.h>
40 #include <security/audit/audit.h>
41 #include <security/audit/audit_private.h>
44 * Structures and operations to support the basic character special device
45 * used to communicate with userland.
49 TAILQ_ENTRY(trigger_info) list;
51 static MALLOC_DEFINE(M_AUDITTRIGGER, "audit_trigger", "Audit trigger events");
52 static struct cdev *audit_dev;
53 static int audit_isopen = 0;
54 static TAILQ_HEAD(, trigger_info) trigger_list;
55 static struct mtx audit_trigger_mtx;
58 audit_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
62 /* Only one process may open the device at a time. */
63 mtx_lock(&audit_trigger_mtx);
69 mtx_unlock(&audit_trigger_mtx);
75 audit_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
77 struct trigger_info *ti;
79 /* Flush the queue of pending trigger events. */
80 mtx_lock(&audit_trigger_mtx);
82 while (!TAILQ_EMPTY(&trigger_list)) {
83 ti = TAILQ_FIRST(&trigger_list);
84 TAILQ_REMOVE(&trigger_list, ti, list);
85 free(ti, M_AUDITTRIGGER);
87 mtx_unlock(&audit_trigger_mtx);
93 audit_read(struct cdev *dev, struct uio *uio, int ioflag)
96 struct trigger_info *ti = NULL;
98 mtx_lock(&audit_trigger_mtx);
99 while (TAILQ_EMPTY(&trigger_list)) {
100 error = msleep(&trigger_list, &audit_trigger_mtx,
101 PSOCK | PCATCH, "auditd", 0);
106 ti = TAILQ_FIRST(&trigger_list);
107 TAILQ_REMOVE(&trigger_list, ti, list);
109 mtx_unlock(&audit_trigger_mtx);
111 error = uiomove(ti, sizeof *ti, uio);
112 free(ti, M_AUDITTRIGGER);
118 audit_write(struct cdev *dev, struct uio *uio, int ioflag)
121 /* Communication is kernel->userspace only. */
126 send_trigger(unsigned int trigger)
128 struct trigger_info *ti;
130 /* If nobody's listening, we ain't talking. */
135 * XXXAUDIT: Use a condition variable instead of msleep/wakeup?
137 ti = malloc(sizeof *ti, M_AUDITTRIGGER, M_WAITOK);
138 mtx_lock(&audit_trigger_mtx);
139 ti->trigger = trigger;
140 TAILQ_INSERT_TAIL(&trigger_list, ti, list);
141 wakeup(&trigger_list);
142 mtx_unlock(&audit_trigger_mtx);
146 static struct cdevsw audit_cdevsw = {
147 .d_version = D_VERSION,
148 .d_open = audit_open,
149 .d_close = audit_close,
150 .d_read = audit_read,
151 .d_write = audit_write,
156 audit_trigger_init(void)
159 TAILQ_INIT(&trigger_list);
160 mtx_init(&audit_trigger_mtx, "audit_trigger_mtx", NULL, MTX_DEF);
164 audit_trigger_cdev_init(void *unused)
167 /* Create the special device file. */
168 audit_dev = make_dev(&audit_cdevsw, 0, UID_ROOT, GID_KMEM, 0600,
172 SYSINIT(audit_trigger_cdev_init, SI_SUB_DRIVERS, SI_ORDER_MIDDLE,
173 audit_trigger_cdev_init, NULL);