projects/linux·blob v2.6.39 · refs

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1/* audit.c -- Auditing support
2 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
4 *
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
6 * All Rights Reserved.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 * Written by Rickard E. (Rik) Faith <[email protected]>
23 *
24 * Goals: 1) Integrate fully with Security Modules.
25 * 2) Minimal run-time overhead:
26 * a) Minimal when syscall auditing is disabled (audit_enable=0).
27 * b) Small when syscall auditing is enabled and no audit record
28 * is generated (defer as much work as possible to record
29 * generation time):
30 * i) context is allocated,
31 * ii) names from getname are stored without a copy, and
32 * iii) inode information stored from path_lookup.
33 * 3) Ability to disable syscall auditing at boot time (audit=0).
34 * 4) Usable by other parts of the kernel (if audit_log* is called,
35 * then a syscall record will be generated automatically for the
36 * current syscall).
37 * 5) Netlink interface to user-space.
38 * 6) Support low-overhead kernel-based filtering to minimize the
39 * information that must be passed to user-space.
40 *
41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
42 */
43
44#include <linux/init.h>
45#include <asm/types.h>
46#include <asm/atomic.h>
47#include <linux/mm.h>
48#include <linux/module.h>
49#include <linux/slab.h>
50#include <linux/err.h>
51#include <linux/kthread.h>
52
53#include <linux/audit.h>
54
55#include <net/sock.h>
56#include <net/netlink.h>
57#include <linux/skbuff.h>
58#include <linux/netlink.h>
59#include <linux/freezer.h>
60#include <linux/tty.h>
61
62#include "audit.h"
63
64/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
65 * (Initialization happens after skb_init is called.) */
66#define AUDIT_DISABLED -1
67#define AUDIT_UNINITIALIZED 0
68#define AUDIT_INITIALIZED 1
69static int audit_initialized;
70
71#define AUDIT_OFF 0
72#define AUDIT_ON 1
73#define AUDIT_LOCKED 2
74int audit_enabled;
75int audit_ever_enabled;
76
77EXPORT_SYMBOL_GPL(audit_enabled);
78
79/* Default state when kernel boots without any parameters. */
80static int audit_default;
81
82/* If auditing cannot proceed, audit_failure selects what happens. */
83static int audit_failure = AUDIT_FAIL_PRINTK;
84
85/*
86 * If audit records are to be written to the netlink socket, audit_pid
87 * contains the pid of the auditd process and audit_nlk_pid contains
88 * the pid to use to send netlink messages to that process.
89 */
90int audit_pid;
91static int audit_nlk_pid;
92
93/* If audit_rate_limit is non-zero, limit the rate of sending audit records
94 * to that number per second. This prevents DoS attacks, but results in
95 * audit records being dropped. */
96static int audit_rate_limit;
97
98/* Number of outstanding audit_buffers allowed. */
99static int audit_backlog_limit = 64;
100static int audit_backlog_wait_time = 60 * HZ;
101static int audit_backlog_wait_overflow = 0;
102
103/* The identity of the user shutting down the audit system. */
104uid_t audit_sig_uid = -1;
105pid_t audit_sig_pid = -1;
106u32 audit_sig_sid = 0;
107
108/* Records can be lost in several ways:
109 0) [suppressed in audit_alloc]
110 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
111 2) out of memory in audit_log_move [alloc_skb]
112 3) suppressed due to audit_rate_limit
113 4) suppressed due to audit_backlog_limit
114*/
115static atomic_t audit_lost = ATOMIC_INIT(0);
116
117/* The netlink socket. */
118static struct sock *audit_sock;
119
120/* Hash for inode-based rules */
121struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
122
123/* The audit_freelist is a list of pre-allocated audit buffers (if more
124 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
125 * being placed on the freelist). */
126static DEFINE_SPINLOCK(audit_freelist_lock);
127static int audit_freelist_count;
128static LIST_HEAD(audit_freelist);
129
130static struct sk_buff_head audit_skb_queue;
131/* queue of skbs to send to auditd when/if it comes back */
132static struct sk_buff_head audit_skb_hold_queue;
133static struct task_struct *kauditd_task;
134static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
135static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
136
137/* Serialize requests from userspace. */
138DEFINE_MUTEX(audit_cmd_mutex);
139
140/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
141 * audit records. Since printk uses a 1024 byte buffer, this buffer
142 * should be at least that large. */
143#define AUDIT_BUFSIZ 1024
144
145/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
146 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
147#define AUDIT_MAXFREE (2*NR_CPUS)
148
149/* The audit_buffer is used when formatting an audit record. The caller
150 * locks briefly to get the record off the freelist or to allocate the
151 * buffer, and locks briefly to send the buffer to the netlink layer or
152 * to place it on a transmit queue. Multiple audit_buffers can be in
153 * use simultaneously. */
154struct audit_buffer {
155 struct list_head list;
156 struct sk_buff *skb; /* formatted skb ready to send */
157 struct audit_context *ctx; /* NULL or associated context */
158 gfp_t gfp_mask;
159};
160
161struct audit_reply {
162 int pid;
163 struct sk_buff *skb;
164};
165
166static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
167{
168 if (ab) {
169 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
170 nlh->nlmsg_pid = pid;
171 }
172}
173
174void audit_panic(const char *message)
175{
176 switch (audit_failure)
177 {
178 case AUDIT_FAIL_SILENT:
179 break;
180 case AUDIT_FAIL_PRINTK:
181 if (printk_ratelimit())
182 printk(KERN_ERR "audit: %s\n", message);
183 break;
184 case AUDIT_FAIL_PANIC:
185 /* test audit_pid since printk is always losey, why bother? */
186 if (audit_pid)
187 panic("audit: %s\n", message);
188 break;
189 }
190}
191
192static inline int audit_rate_check(void)
193{
194 static unsigned long last_check = 0;
195 static int messages = 0;
196 static DEFINE_SPINLOCK(lock);
197 unsigned long flags;
198 unsigned long now;
199 unsigned long elapsed;
200 int retval = 0;
201
202 if (!audit_rate_limit) return 1;
203
204 spin_lock_irqsave(&lock, flags);
205 if (++messages < audit_rate_limit) {
206 retval = 1;
207 } else {
208 now = jiffies;
209 elapsed = now - last_check;
210 if (elapsed > HZ) {
211 last_check = now;
212 messages = 0;
213 retval = 1;
214 }
215 }
216 spin_unlock_irqrestore(&lock, flags);
217
218 return retval;
219}
220
221/**
222 * audit_log_lost - conditionally log lost audit message event
223 * @message: the message stating reason for lost audit message
224 *
225 * Emit at least 1 message per second, even if audit_rate_check is
226 * throttling.
227 * Always increment the lost messages counter.
228*/
229void audit_log_lost(const char *message)
230{
231 static unsigned long last_msg = 0;
232 static DEFINE_SPINLOCK(lock);
233 unsigned long flags;
234 unsigned long now;
235 int print;
236
237 atomic_inc(&audit_lost);
238
239 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
240
241 if (!print) {
242 spin_lock_irqsave(&lock, flags);
243 now = jiffies;
244 if (now - last_msg > HZ) {
245 print = 1;
246 last_msg = now;
247 }
248 spin_unlock_irqrestore(&lock, flags);
249 }
250
251 if (print) {
252 if (printk_ratelimit())
253 printk(KERN_WARNING
254 "audit: audit_lost=%d audit_rate_limit=%d "
255 "audit_backlog_limit=%d\n",
256 atomic_read(&audit_lost),
257 audit_rate_limit,
258 audit_backlog_limit);
259 audit_panic(message);
260 }
261}
262
263static int audit_log_config_change(char *function_name, int new, int old,
264 uid_t loginuid, u32 sessionid, u32 sid,
265 int allow_changes)
266{
267 struct audit_buffer *ab;
268 int rc = 0;
269
270 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
271 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
272 old, loginuid, sessionid);
273 if (sid) {
274 char *ctx = NULL;
275 u32 len;
276
277 rc = security_secid_to_secctx(sid, &ctx, &len);
278 if (rc) {
279 audit_log_format(ab, " sid=%u", sid);
280 allow_changes = 0; /* Something weird, deny request */
281 } else {
282 audit_log_format(ab, " subj=%s", ctx);
283 security_release_secctx(ctx, len);
284 }
285 }
286 audit_log_format(ab, " res=%d", allow_changes);
287 audit_log_end(ab);
288 return rc;
289}
290
291static int audit_do_config_change(char *function_name, int *to_change,
292 int new, uid_t loginuid, u32 sessionid,
293 u32 sid)
294{
295 int allow_changes, rc = 0, old = *to_change;
296
297 /* check if we are locked */
298 if (audit_enabled == AUDIT_LOCKED)
299 allow_changes = 0;
300 else
301 allow_changes = 1;
302
303 if (audit_enabled != AUDIT_OFF) {
304 rc = audit_log_config_change(function_name, new, old, loginuid,
305 sessionid, sid, allow_changes);
306 if (rc)
307 allow_changes = 0;
308 }
309
310 /* If we are allowed, make the change */
311 if (allow_changes == 1)
312 *to_change = new;
313 /* Not allowed, update reason */
314 else if (rc == 0)
315 rc = -EPERM;
316 return rc;
317}
318
319static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
320 u32 sid)
321{
322 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
323 limit, loginuid, sessionid, sid);
324}
325
326static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
327 u32 sid)
328{
329 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
330 limit, loginuid, sessionid, sid);
331}
332
333static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
334{
335 int rc;
336 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
337 return -EINVAL;
338
339 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
340 loginuid, sessionid, sid);
341
342 if (!rc)
343 audit_ever_enabled |= !!state;
344
345 return rc;
346}
347
348static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
349{
350 if (state != AUDIT_FAIL_SILENT
351 && state != AUDIT_FAIL_PRINTK
352 && state != AUDIT_FAIL_PANIC)
353 return -EINVAL;
354
355 return audit_do_config_change("audit_failure", &audit_failure, state,
356 loginuid, sessionid, sid);
357}
358
359/*
360 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
361 * already have been sent via prink/syslog and so if these messages are dropped
362 * it is not a huge concern since we already passed the audit_log_lost()
363 * notification and stuff. This is just nice to get audit messages during
364 * boot before auditd is running or messages generated while auditd is stopped.
365 * This only holds messages is audit_default is set, aka booting with audit=1
366 * or building your kernel that way.
367 */
368static void audit_hold_skb(struct sk_buff *skb)
369{
370 if (audit_default &&
371 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
372 skb_queue_tail(&audit_skb_hold_queue, skb);
373 else
374 kfree_skb(skb);
375}
376
377/*
378 * For one reason or another this nlh isn't getting delivered to the userspace
379 * audit daemon, just send it to printk.
380 */
381static void audit_printk_skb(struct sk_buff *skb)
382{
383 struct nlmsghdr *nlh = nlmsg_hdr(skb);
384 char *data = NLMSG_DATA(nlh);
385
386 if (nlh->nlmsg_type != AUDIT_EOE) {
387 if (printk_ratelimit())
388 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
389 else
390 audit_log_lost("printk limit exceeded\n");
391 }
392
393 audit_hold_skb(skb);
394}
395
396static void kauditd_send_skb(struct sk_buff *skb)
397{
398 int err;
399 /* take a reference in case we can't send it and we want to hold it */
400 skb_get(skb);
401 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
402 if (err < 0) {
403 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
404 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
405 audit_log_lost("auditd disappeared\n");
406 audit_pid = 0;
407 /* we might get lucky and get this in the next auditd */
408 audit_hold_skb(skb);
409 } else
410 /* drop the extra reference if sent ok */
411 consume_skb(skb);
412}
413
414static int kauditd_thread(void *dummy)
415{
416 struct sk_buff *skb;
417
418 set_freezable();
419 while (!kthread_should_stop()) {
420 /*
421 * if auditd just started drain the queue of messages already
422 * sent to syslog/printk. remember loss here is ok. we already
423 * called audit_log_lost() if it didn't go out normally. so the
424 * race between the skb_dequeue and the next check for audit_pid
425 * doesn't matter.
426 *
427 * if you ever find kauditd to be too slow we can get a perf win
428 * by doing our own locking and keeping better track if there
429 * are messages in this queue. I don't see the need now, but
430 * in 5 years when I want to play with this again I'll see this
431 * note and still have no friggin idea what i'm thinking today.
432 */
433 if (audit_default && audit_pid) {
434 skb = skb_dequeue(&audit_skb_hold_queue);
435 if (unlikely(skb)) {
436 while (skb && audit_pid) {
437 kauditd_send_skb(skb);
438 skb = skb_dequeue(&audit_skb_hold_queue);
439 }
440 }
441 }
442
443 skb = skb_dequeue(&audit_skb_queue);
444 wake_up(&audit_backlog_wait);
445 if (skb) {
446 if (audit_pid)
447 kauditd_send_skb(skb);
448 else
449 audit_printk_skb(skb);
450 } else {
451 DECLARE_WAITQUEUE(wait, current);
452 set_current_state(TASK_INTERRUPTIBLE);
453 add_wait_queue(&kauditd_wait, &wait);
454
455 if (!skb_queue_len(&audit_skb_queue)) {
456 try_to_freeze();
457 schedule();
458 }
459
460 __set_current_state(TASK_RUNNING);
461 remove_wait_queue(&kauditd_wait, &wait);
462 }
463 }
464 return 0;
465}
466
467static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
468{
469 struct task_struct *tsk;
470 int err;
471
472 rcu_read_lock();
473 tsk = find_task_by_vpid(pid);
474 if (!tsk) {
475 rcu_read_unlock();
476 return -ESRCH;
477 }
478 get_task_struct(tsk);
479 rcu_read_unlock();
480 err = tty_audit_push_task(tsk, loginuid, sessionid);
481 put_task_struct(tsk);
482 return err;
483}
484
485int audit_send_list(void *_dest)
486{
487 struct audit_netlink_list *dest = _dest;
488 int pid = dest->pid;
489 struct sk_buff *skb;
490
491 /* wait for parent to finish and send an ACK */
492 mutex_lock(&audit_cmd_mutex);
493 mutex_unlock(&audit_cmd_mutex);
494
495 while ((skb = __skb_dequeue(&dest->q)) != NULL)
496 netlink_unicast(audit_sock, skb, pid, 0);
497
498 kfree(dest);
499
500 return 0;
501}
502
503struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
504 int multi, const void *payload, int size)
505{
506 struct sk_buff *skb;
507 struct nlmsghdr *nlh;
508 void *data;
509 int flags = multi ? NLM_F_MULTI : 0;
510 int t = done ? NLMSG_DONE : type;
511
512 skb = nlmsg_new(size, GFP_KERNEL);
513 if (!skb)
514 return NULL;
515
516 nlh = NLMSG_NEW(skb, pid, seq, t, size, flags);
517 data = NLMSG_DATA(nlh);
518 memcpy(data, payload, size);
519 return skb;
520
521nlmsg_failure: /* Used by NLMSG_NEW */
522 if (skb)
523 kfree_skb(skb);
524 return NULL;
525}
526
527static int audit_send_reply_thread(void *arg)
528{
529 struct audit_reply *reply = (struct audit_reply *)arg;
530
531 mutex_lock(&audit_cmd_mutex);
532 mutex_unlock(&audit_cmd_mutex);
533
534 /* Ignore failure. It'll only happen if the sender goes away,
535 because our timeout is set to infinite. */
536 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
537 kfree(reply);
538 return 0;
539}
540/**
541 * audit_send_reply - send an audit reply message via netlink
542 * @pid: process id to send reply to
543 * @seq: sequence number
544 * @type: audit message type
545 * @done: done (last) flag
546 * @multi: multi-part message flag
547 * @payload: payload data
548 * @size: payload size
549 *
550 * Allocates an skb, builds the netlink message, and sends it to the pid.
551 * No failure notifications.
552 */
553static void audit_send_reply(int pid, int seq, int type, int done, int multi,
554 const void *payload, int size)
555{
556 struct sk_buff *skb;
557 struct task_struct *tsk;
558 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
559 GFP_KERNEL);
560
561 if (!reply)
562 return;
563
564 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
565 if (!skb)
566 goto out;
567
568 reply->pid = pid;
569 reply->skb = skb;
570
571 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
572 if (!IS_ERR(tsk))
573 return;
574 kfree_skb(skb);
575out:
576 kfree(reply);
577}
578
579/*
580 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
581 * control messages.
582 */
583static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
584{
585 int err = 0;
586
587 switch (msg_type) {
588 case AUDIT_GET:
589 case AUDIT_LIST:
590 case AUDIT_LIST_RULES:
591 case AUDIT_SET:
592 case AUDIT_ADD:
593 case AUDIT_ADD_RULE:
594 case AUDIT_DEL:
595 case AUDIT_DEL_RULE:
596 case AUDIT_SIGNAL_INFO:
597 case AUDIT_TTY_GET:
598 case AUDIT_TTY_SET:
599 case AUDIT_TRIM:
600 case AUDIT_MAKE_EQUIV:
601 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
602 err = -EPERM;
603 break;
604 case AUDIT_USER:
605 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
606 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
607 if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
608 err = -EPERM;
609 break;
610 default: /* bad msg */
611 err = -EINVAL;
612 }
613
614 return err;
615}
616
617static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
618 u32 pid, u32 uid, uid_t auid, u32 ses,
619 u32 sid)
620{
621 int rc = 0;
622 char *ctx = NULL;
623 u32 len;
624
625 if (!audit_enabled) {
626 *ab = NULL;
627 return rc;
628 }
629
630 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
631 audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
632 pid, uid, auid, ses);
633 if (sid) {
634 rc = security_secid_to_secctx(sid, &ctx, &len);
635 if (rc)
636 audit_log_format(*ab, " ssid=%u", sid);
637 else {
638 audit_log_format(*ab, " subj=%s", ctx);
639 security_release_secctx(ctx, len);
640 }
641 }
642
643 return rc;
644}
645
646static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
647{
648 u32 uid, pid, seq, sid;
649 void *data;
650 struct audit_status *status_get, status_set;
651 int err;
652 struct audit_buffer *ab;
653 u16 msg_type = nlh->nlmsg_type;
654 uid_t loginuid; /* loginuid of sender */
655 u32 sessionid;
656 struct audit_sig_info *sig_data;
657 char *ctx = NULL;
658 u32 len;
659
660 err = audit_netlink_ok(skb, msg_type);
661 if (err)
662 return err;
663
664 /* As soon as there's any sign of userspace auditd,
665 * start kauditd to talk to it */
666 if (!kauditd_task)
667 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
668 if (IS_ERR(kauditd_task)) {
669 err = PTR_ERR(kauditd_task);
670 kauditd_task = NULL;
671 return err;
672 }
673
674 pid = NETLINK_CREDS(skb)->pid;
675 uid = NETLINK_CREDS(skb)->uid;
676 loginuid = audit_get_loginuid(current);
677 sessionid = audit_get_sessionid(current);
678 security_task_getsecid(current, &sid);
679 seq = nlh->nlmsg_seq;
680 data = NLMSG_DATA(nlh);
681
682 switch (msg_type) {
683 case AUDIT_GET:
684 status_set.enabled = audit_enabled;
685 status_set.failure = audit_failure;
686 status_set.pid = audit_pid;
687 status_set.rate_limit = audit_rate_limit;
688 status_set.backlog_limit = audit_backlog_limit;
689 status_set.lost = atomic_read(&audit_lost);
690 status_set.backlog = skb_queue_len(&audit_skb_queue);
691 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
692 &status_set, sizeof(status_set));
693 break;
694 case AUDIT_SET:
695 if (nlh->nlmsg_len < sizeof(struct audit_status))
696 return -EINVAL;
697 status_get = (struct audit_status *)data;
698 if (status_get->mask & AUDIT_STATUS_ENABLED) {
699 err = audit_set_enabled(status_get->enabled,
700 loginuid, sessionid, sid);
701 if (err < 0)
702 return err;
703 }
704 if (status_get->mask & AUDIT_STATUS_FAILURE) {
705 err = audit_set_failure(status_get->failure,
706 loginuid, sessionid, sid);
707 if (err < 0)
708 return err;
709 }
710 if (status_get->mask & AUDIT_STATUS_PID) {
711 int new_pid = status_get->pid;
712
713 if (audit_enabled != AUDIT_OFF)
714 audit_log_config_change("audit_pid", new_pid,
715 audit_pid, loginuid,
716 sessionid, sid, 1);
717
718 audit_pid = new_pid;
719 audit_nlk_pid = NETLINK_CB(skb).pid;
720 }
721 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
722 err = audit_set_rate_limit(status_get->rate_limit,
723 loginuid, sessionid, sid);
724 if (err < 0)
725 return err;
726 }
727 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
728 err = audit_set_backlog_limit(status_get->backlog_limit,
729 loginuid, sessionid, sid);
730 break;
731 case AUDIT_USER:
732 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
733 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
734 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
735 return 0;
736
737 err = audit_filter_user(&NETLINK_CB(skb));
738 if (err == 1) {
739 err = 0;
740 if (msg_type == AUDIT_USER_TTY) {
741 err = audit_prepare_user_tty(pid, loginuid,
742 sessionid);
743 if (err)
744 break;
745 }
746 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
747 loginuid, sessionid, sid);
748
749 if (msg_type != AUDIT_USER_TTY)
750 audit_log_format(ab, " msg='%.1024s'",
751 (char *)data);
752 else {
753 int size;
754
755 audit_log_format(ab, " msg=");
756 size = nlmsg_len(nlh);
757 if (size > 0 &&
758 ((unsigned char *)data)[size - 1] == '\0')
759 size--;
760 audit_log_n_untrustedstring(ab, data, size);
761 }
762 audit_set_pid(ab, pid);
763 audit_log_end(ab);
764 }
765 break;
766 case AUDIT_ADD:
767 case AUDIT_DEL:
768 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
769 return -EINVAL;
770 if (audit_enabled == AUDIT_LOCKED) {
771 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
772 uid, loginuid, sessionid, sid);
773
774 audit_log_format(ab, " audit_enabled=%d res=0",
775 audit_enabled);
776 audit_log_end(ab);
777 return -EPERM;
778 }
779 /* fallthrough */
780 case AUDIT_LIST:
781 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
782 uid, seq, data, nlmsg_len(nlh),
783 loginuid, sessionid, sid);
784 break;
785 case AUDIT_ADD_RULE:
786 case AUDIT_DEL_RULE:
787 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
788 return -EINVAL;
789 if (audit_enabled == AUDIT_LOCKED) {
790 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
791 uid, loginuid, sessionid, sid);
792
793 audit_log_format(ab, " audit_enabled=%d res=0",
794 audit_enabled);
795 audit_log_end(ab);
796 return -EPERM;
797 }
798 /* fallthrough */
799 case AUDIT_LIST_RULES:
800 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
801 uid, seq, data, nlmsg_len(nlh),
802 loginuid, sessionid, sid);
803 break;
804 case AUDIT_TRIM:
805 audit_trim_trees();
806
807 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
808 uid, loginuid, sessionid, sid);
809
810 audit_log_format(ab, " op=trim res=1");
811 audit_log_end(ab);
812 break;
813 case AUDIT_MAKE_EQUIV: {
814 void *bufp = data;
815 u32 sizes[2];
816 size_t msglen = nlmsg_len(nlh);
817 char *old, *new;
818
819 err = -EINVAL;
820 if (msglen < 2 * sizeof(u32))
821 break;
822 memcpy(sizes, bufp, 2 * sizeof(u32));
823 bufp += 2 * sizeof(u32);
824 msglen -= 2 * sizeof(u32);
825 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
826 if (IS_ERR(old)) {
827 err = PTR_ERR(old);
828 break;
829 }
830 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
831 if (IS_ERR(new)) {
832 err = PTR_ERR(new);
833 kfree(old);
834 break;
835 }
836 /* OK, here comes... */
837 err = audit_tag_tree(old, new);
838
839 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
840 uid, loginuid, sessionid, sid);
841
842 audit_log_format(ab, " op=make_equiv old=");
843 audit_log_untrustedstring(ab, old);
844 audit_log_format(ab, " new=");
845 audit_log_untrustedstring(ab, new);
846 audit_log_format(ab, " res=%d", !err);
847 audit_log_end(ab);
848 kfree(old);
849 kfree(new);
850 break;
851 }
852 case AUDIT_SIGNAL_INFO:
853 len = 0;
854 if (audit_sig_sid) {
855 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
856 if (err)
857 return err;
858 }
859 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
860 if (!sig_data) {
861 if (audit_sig_sid)
862 security_release_secctx(ctx, len);
863 return -ENOMEM;
864 }
865 sig_data->uid = audit_sig_uid;
866 sig_data->pid = audit_sig_pid;
867 if (audit_sig_sid) {
868 memcpy(sig_data->ctx, ctx, len);
869 security_release_secctx(ctx, len);
870 }
871 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
872 0, 0, sig_data, sizeof(*sig_data) + len);
873 kfree(sig_data);
874 break;
875 case AUDIT_TTY_GET: {
876 struct audit_tty_status s;
877 struct task_struct *tsk;
878 unsigned long flags;
879
880 rcu_read_lock();
881 tsk = find_task_by_vpid(pid);
882 if (tsk && lock_task_sighand(tsk, &flags)) {
883 s.enabled = tsk->signal->audit_tty != 0;
884 unlock_task_sighand(tsk, &flags);
885 } else
886 err = -ESRCH;
887 rcu_read_unlock();
888
889 if (!err)
890 audit_send_reply(NETLINK_CB(skb).pid, seq,
891 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
892 break;
893 }
894 case AUDIT_TTY_SET: {
895 struct audit_tty_status *s;
896 struct task_struct *tsk;
897 unsigned long flags;
898
899 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
900 return -EINVAL;
901 s = data;
902 if (s->enabled != 0 && s->enabled != 1)
903 return -EINVAL;
904 rcu_read_lock();
905 tsk = find_task_by_vpid(pid);
906 if (tsk && lock_task_sighand(tsk, &flags)) {
907 tsk->signal->audit_tty = s->enabled != 0;
908 unlock_task_sighand(tsk, &flags);
909 } else
910 err = -ESRCH;
911 rcu_read_unlock();
912 break;
913 }
914 default:
915 err = -EINVAL;
916 break;
917 }
918
919 return err < 0 ? err : 0;
920}
921
922/*
923 * Get message from skb. Each message is processed by audit_receive_msg.
924 * Malformed skbs with wrong length are discarded silently.
925 */
926static void audit_receive_skb(struct sk_buff *skb)
927{
928 struct nlmsghdr *nlh;
929 /*
930 * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
931 * if the nlmsg_len was not aligned
932 */
933 int len;
934 int err;
935
936 nlh = nlmsg_hdr(skb);
937 len = skb->len;
938
939 while (NLMSG_OK(nlh, len)) {
940 err = audit_receive_msg(skb, nlh);
941 /* if err or if this message says it wants a response */
942 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
943 netlink_ack(skb, nlh, err);
944
945 nlh = NLMSG_NEXT(nlh, len);
946 }
947}
948
949/* Receive messages from netlink socket. */
950static void audit_receive(struct sk_buff *skb)
951{
952 mutex_lock(&audit_cmd_mutex);
953 audit_receive_skb(skb);
954 mutex_unlock(&audit_cmd_mutex);
955}
956
957/* Initialize audit support at boot time. */
958static int __init audit_init(void)
959{
960 int i;
961
962 if (audit_initialized == AUDIT_DISABLED)
963 return 0;
964
965 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
966 audit_default ? "enabled" : "disabled");
967 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
968 audit_receive, NULL, THIS_MODULE);
969 if (!audit_sock)
970 audit_panic("cannot initialize netlink socket");
971 else
972 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
973
974 skb_queue_head_init(&audit_skb_queue);
975 skb_queue_head_init(&audit_skb_hold_queue);
976 audit_initialized = AUDIT_INITIALIZED;
977 audit_enabled = audit_default;
978 audit_ever_enabled |= !!audit_default;
979
980 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
981
982 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
983 INIT_LIST_HEAD(&audit_inode_hash[i]);
984
985 return 0;
986}
987__initcall(audit_init);
988
989/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
990static int __init audit_enable(char *str)
991{
992 audit_default = !!simple_strtol(str, NULL, 0);
993 if (!audit_default)
994 audit_initialized = AUDIT_DISABLED;
995
996 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
997
998 if (audit_initialized == AUDIT_INITIALIZED) {
999 audit_enabled = audit_default;
1000 audit_ever_enabled |= !!audit_default;
1001 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1002 printk(" (after initialization)");
1003 } else {
1004 printk(" (until reboot)");
1005 }
1006 printk("\n");
1007
1008 return 1;
1009}
1010
1011__setup("audit=", audit_enable);
1012
1013static void audit_buffer_free(struct audit_buffer *ab)
1014{
1015 unsigned long flags;
1016
1017 if (!ab)
1018 return;
1019
1020 if (ab->skb)
1021 kfree_skb(ab->skb);
1022
1023 spin_lock_irqsave(&audit_freelist_lock, flags);
1024 if (audit_freelist_count > AUDIT_MAXFREE)
1025 kfree(ab);
1026 else {
1027 audit_freelist_count++;
1028 list_add(&ab->list, &audit_freelist);
1029 }
1030 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1031}
1032
1033static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1034 gfp_t gfp_mask, int type)
1035{
1036 unsigned long flags;
1037 struct audit_buffer *ab = NULL;
1038 struct nlmsghdr *nlh;
1039
1040 spin_lock_irqsave(&audit_freelist_lock, flags);
1041 if (!list_empty(&audit_freelist)) {
1042 ab = list_entry(audit_freelist.next,
1043 struct audit_buffer, list);
1044 list_del(&ab->list);
1045 --audit_freelist_count;
1046 }
1047 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1048
1049 if (!ab) {
1050 ab = kmalloc(sizeof(*ab), gfp_mask);
1051 if (!ab)
1052 goto err;
1053 }
1054
1055 ab->ctx = ctx;
1056 ab->gfp_mask = gfp_mask;
1057
1058 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1059 if (!ab->skb)
1060 goto nlmsg_failure;
1061
1062 nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0);
1063
1064 return ab;
1065
1066nlmsg_failure: /* Used by NLMSG_NEW */
1067 kfree_skb(ab->skb);
1068 ab->skb = NULL;
1069err:
1070 audit_buffer_free(ab);
1071 return NULL;
1072}
1073
1074/**
1075 * audit_serial - compute a serial number for the audit record
1076 *
1077 * Compute a serial number for the audit record. Audit records are
1078 * written to user-space as soon as they are generated, so a complete
1079 * audit record may be written in several pieces. The timestamp of the
1080 * record and this serial number are used by the user-space tools to
1081 * determine which pieces belong to the same audit record. The
1082 * (timestamp,serial) tuple is unique for each syscall and is live from
1083 * syscall entry to syscall exit.
1084 *
1085 * NOTE: Another possibility is to store the formatted records off the
1086 * audit context (for those records that have a context), and emit them
1087 * all at syscall exit. However, this could delay the reporting of
1088 * significant errors until syscall exit (or never, if the system
1089 * halts).
1090 */
1091unsigned int audit_serial(void)
1092{
1093 static DEFINE_SPINLOCK(serial_lock);
1094 static unsigned int serial = 0;
1095
1096 unsigned long flags;
1097 unsigned int ret;
1098
1099 spin_lock_irqsave(&serial_lock, flags);
1100 do {
1101 ret = ++serial;
1102 } while (unlikely(!ret));
1103 spin_unlock_irqrestore(&serial_lock, flags);
1104
1105 return ret;
1106}
1107
1108static inline void audit_get_stamp(struct audit_context *ctx,
1109 struct timespec *t, unsigned int *serial)
1110{
1111 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1112 *t = CURRENT_TIME;
1113 *serial = audit_serial();
1114 }
1115}
1116
1117/* Obtain an audit buffer. This routine does locking to obtain the
1118 * audit buffer, but then no locking is required for calls to
1119 * audit_log_*format. If the tsk is a task that is currently in a
1120 * syscall, then the syscall is marked as auditable and an audit record
1121 * will be written at syscall exit. If there is no associated task, tsk
1122 * should be NULL. */
1123
1124/**
1125 * audit_log_start - obtain an audit buffer
1126 * @ctx: audit_context (may be NULL)
1127 * @gfp_mask: type of allocation
1128 * @type: audit message type
1129 *
1130 * Returns audit_buffer pointer on success or NULL on error.
1131 *
1132 * Obtain an audit buffer. This routine does locking to obtain the
1133 * audit buffer, but then no locking is required for calls to
1134 * audit_log_*format. If the task (ctx) is a task that is currently in a
1135 * syscall, then the syscall is marked as auditable and an audit record
1136 * will be written at syscall exit. If there is no associated task, then
1137 * task context (ctx) should be NULL.
1138 */
1139struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1140 int type)
1141{
1142 struct audit_buffer *ab = NULL;
1143 struct timespec t;
1144 unsigned int uninitialized_var(serial);
1145 int reserve;
1146 unsigned long timeout_start = jiffies;
1147
1148 if (audit_initialized != AUDIT_INITIALIZED)
1149 return NULL;
1150
1151 if (unlikely(audit_filter_type(type)))
1152 return NULL;
1153
1154 if (gfp_mask & __GFP_WAIT)
1155 reserve = 0;
1156 else
1157 reserve = 5; /* Allow atomic callers to go up to five
1158 entries over the normal backlog limit */
1159
1160 while (audit_backlog_limit
1161 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1162 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1163 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1164
1165 /* Wait for auditd to drain the queue a little */
1166 DECLARE_WAITQUEUE(wait, current);
1167 set_current_state(TASK_INTERRUPTIBLE);
1168 add_wait_queue(&audit_backlog_wait, &wait);
1169
1170 if (audit_backlog_limit &&
1171 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1172 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
1173
1174 __set_current_state(TASK_RUNNING);
1175 remove_wait_queue(&audit_backlog_wait, &wait);
1176 continue;
1177 }
1178 if (audit_rate_check() && printk_ratelimit())
1179 printk(KERN_WARNING
1180 "audit: audit_backlog=%d > "
1181 "audit_backlog_limit=%d\n",
1182 skb_queue_len(&audit_skb_queue),
1183 audit_backlog_limit);
1184 audit_log_lost("backlog limit exceeded");
1185 audit_backlog_wait_time = audit_backlog_wait_overflow;
1186 wake_up(&audit_backlog_wait);
1187 return NULL;
1188 }
1189
1190 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1191 if (!ab) {
1192 audit_log_lost("out of memory in audit_log_start");
1193 return NULL;
1194 }
1195
1196 audit_get_stamp(ab->ctx, &t, &serial);
1197
1198 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1199 t.tv_sec, t.tv_nsec/1000000, serial);
1200 return ab;
1201}
1202
1203/**
1204 * audit_expand - expand skb in the audit buffer
1205 * @ab: audit_buffer
1206 * @extra: space to add at tail of the skb
1207 *
1208 * Returns 0 (no space) on failed expansion, or available space if
1209 * successful.
1210 */
1211static inline int audit_expand(struct audit_buffer *ab, int extra)
1212{
1213 struct sk_buff *skb = ab->skb;
1214 int oldtail = skb_tailroom(skb);
1215 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1216 int newtail = skb_tailroom(skb);
1217
1218 if (ret < 0) {
1219 audit_log_lost("out of memory in audit_expand");
1220 return 0;
1221 }
1222
1223 skb->truesize += newtail - oldtail;
1224 return newtail;
1225}
1226
1227/*
1228 * Format an audit message into the audit buffer. If there isn't enough
1229 * room in the audit buffer, more room will be allocated and vsnprint
1230 * will be called a second time. Currently, we assume that a printk
1231 * can't format message larger than 1024 bytes, so we don't either.
1232 */
1233static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1234 va_list args)
1235{
1236 int len, avail;
1237 struct sk_buff *skb;
1238 va_list args2;
1239
1240 if (!ab)
1241 return;
1242
1243 BUG_ON(!ab->skb);
1244 skb = ab->skb;
1245 avail = skb_tailroom(skb);
1246 if (avail == 0) {
1247 avail = audit_expand(ab, AUDIT_BUFSIZ);
1248 if (!avail)
1249 goto out;
1250 }
1251 va_copy(args2, args);
1252 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1253 if (len >= avail) {
1254 /* The printk buffer is 1024 bytes long, so if we get
1255 * here and AUDIT_BUFSIZ is at least 1024, then we can
1256 * log everything that printk could have logged. */
1257 avail = audit_expand(ab,
1258 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1259 if (!avail)
1260 goto out;
1261 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1262 }
1263 va_end(args2);
1264 if (len > 0)
1265 skb_put(skb, len);
1266out:
1267 return;
1268}
1269
1270/**
1271 * audit_log_format - format a message into the audit buffer.
1272 * @ab: audit_buffer
1273 * @fmt: format string
1274 * @...: optional parameters matching @fmt string
1275 *
1276 * All the work is done in audit_log_vformat.
1277 */
1278void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1279{
1280 va_list args;
1281
1282 if (!ab)
1283 return;
1284 va_start(args, fmt);
1285 audit_log_vformat(ab, fmt, args);
1286 va_end(args);
1287}
1288
1289/**
1290 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1291 * @ab: the audit_buffer
1292 * @buf: buffer to convert to hex
1293 * @len: length of @buf to be converted
1294 *
1295 * No return value; failure to expand is silently ignored.
1296 *
1297 * This function will take the passed buf and convert it into a string of
1298 * ascii hex digits. The new string is placed onto the skb.
1299 */
1300void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1301 size_t len)
1302{
1303 int i, avail, new_len;
1304 unsigned char *ptr;
1305 struct sk_buff *skb;
1306 static const unsigned char *hex = "0123456789ABCDEF";
1307
1308 if (!ab)
1309 return;
1310
1311 BUG_ON(!ab->skb);
1312 skb = ab->skb;
1313 avail = skb_tailroom(skb);
1314 new_len = len<<1;
1315 if (new_len >= avail) {
1316 /* Round the buffer request up to the next multiple */
1317 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1318 avail = audit_expand(ab, new_len);
1319 if (!avail)
1320 return;
1321 }
1322
1323 ptr = skb_tail_pointer(skb);
1324 for (i=0; i<len; i++) {
1325 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1326 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1327 }
1328 *ptr = 0;
1329 skb_put(skb, len << 1); /* new string is twice the old string */
1330}
1331
1332/*
1333 * Format a string of no more than slen characters into the audit buffer,
1334 * enclosed in quote marks.
1335 */
1336void audit_log_n_string(struct audit_buffer *ab, const char *string,
1337 size_t slen)
1338{
1339 int avail, new_len;
1340 unsigned char *ptr;
1341 struct sk_buff *skb;
1342
1343 if (!ab)
1344 return;
1345
1346 BUG_ON(!ab->skb);
1347 skb = ab->skb;
1348 avail = skb_tailroom(skb);
1349 new_len = slen + 3; /* enclosing quotes + null terminator */
1350 if (new_len > avail) {
1351 avail = audit_expand(ab, new_len);
1352 if (!avail)
1353 return;
1354 }
1355 ptr = skb_tail_pointer(skb);
1356 *ptr++ = '"';
1357 memcpy(ptr, string, slen);
1358 ptr += slen;
1359 *ptr++ = '"';
1360 *ptr = 0;
1361 skb_put(skb, slen + 2); /* don't include null terminator */
1362}
1363
1364/**
1365 * audit_string_contains_control - does a string need to be logged in hex
1366 * @string: string to be checked
1367 * @len: max length of the string to check
1368 */
1369int audit_string_contains_control(const char *string, size_t len)
1370{
1371 const unsigned char *p;
1372 for (p = string; p < (const unsigned char *)string + len; p++) {
1373 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1374 return 1;
1375 }
1376 return 0;
1377}
1378
1379/**
1380 * audit_log_n_untrustedstring - log a string that may contain random characters
1381 * @ab: audit_buffer
1382 * @len: length of string (not including trailing null)
1383 * @string: string to be logged
1384 *
1385 * This code will escape a string that is passed to it if the string
1386 * contains a control character, unprintable character, double quote mark,
1387 * or a space. Unescaped strings will start and end with a double quote mark.
1388 * Strings that are escaped are printed in hex (2 digits per char).
1389 *
1390 * The caller specifies the number of characters in the string to log, which may
1391 * or may not be the entire string.
1392 */
1393void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1394 size_t len)
1395{
1396 if (audit_string_contains_control(string, len))
1397 audit_log_n_hex(ab, string, len);
1398 else
1399 audit_log_n_string(ab, string, len);
1400}
1401
1402/**
1403 * audit_log_untrustedstring - log a string that may contain random characters
1404 * @ab: audit_buffer
1405 * @string: string to be logged
1406 *
1407 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1408 * determine string length.
1409 */
1410void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1411{
1412 audit_log_n_untrustedstring(ab, string, strlen(string));
1413}
1414
1415/* This is a helper-function to print the escaped d_path */
1416void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1417 struct path *path)
1418{
1419 char *p, *pathname;
1420
1421 if (prefix)
1422 audit_log_format(ab, " %s", prefix);
1423
1424 /* We will allow 11 spaces for ' (deleted)' to be appended */
1425 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1426 if (!pathname) {
1427 audit_log_string(ab, "<no_memory>");
1428 return;
1429 }
1430 p = d_path(path, pathname, PATH_MAX+11);
1431 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1432 /* FIXME: can we save some information here? */
1433 audit_log_string(ab, "<too_long>");
1434 } else
1435 audit_log_untrustedstring(ab, p);
1436 kfree(pathname);
1437}
1438
1439void audit_log_key(struct audit_buffer *ab, char *key)
1440{
1441 audit_log_format(ab, " key=");
1442 if (key)
1443 audit_log_untrustedstring(ab, key);
1444 else
1445 audit_log_format(ab, "(null)");
1446}
1447
1448/**
1449 * audit_log_end - end one audit record
1450 * @ab: the audit_buffer
1451 *
1452 * The netlink_* functions cannot be called inside an irq context, so
1453 * the audit buffer is placed on a queue and a tasklet is scheduled to
1454 * remove them from the queue outside the irq context. May be called in
1455 * any context.
1456 */
1457void audit_log_end(struct audit_buffer *ab)
1458{
1459 if (!ab)
1460 return;
1461 if (!audit_rate_check()) {
1462 audit_log_lost("rate limit exceeded");
1463 } else {
1464 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1465 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1466
1467 if (audit_pid) {
1468 skb_queue_tail(&audit_skb_queue, ab->skb);
1469 wake_up_interruptible(&kauditd_wait);
1470 } else {
1471 audit_printk_skb(ab->skb);
1472 }
1473 ab->skb = NULL;
1474 }
1475 audit_buffer_free(ab);
1476}
1477
1478/**
1479 * audit_log - Log an audit record
1480 * @ctx: audit context
1481 * @gfp_mask: type of allocation
1482 * @type: audit message type
1483 * @fmt: format string to use
1484 * @...: variable parameters matching the format string
1485 *
1486 * This is a convenience function that calls audit_log_start,
1487 * audit_log_vformat, and audit_log_end. It may be called
1488 * in any context.
1489 */
1490void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1491 const char *fmt, ...)
1492{
1493 struct audit_buffer *ab;
1494 va_list args;
1495
1496 ab = audit_log_start(ctx, gfp_mask, type);
1497 if (ab) {
1498 va_start(args, fmt);
1499 audit_log_vformat(ab, fmt, args);
1500 va_end(args);
1501 audit_log_end(ab);
1502 }
1503}
1504
1505EXPORT_SYMBOL(audit_log_start);
1506EXPORT_SYMBOL(audit_log_end);
1507EXPORT_SYMBOL(audit_log_format);
1508EXPORT_SYMBOL(audit_log);