Kernel

Kernel Git Source Tree

Root/kernel/audit.c

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 <faith@redhat.com>
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/inotify.h>
60	#include <linux/freezer.h>
61	#include <linux/tty.h>
62
63	#include "audit.h"
64
65	/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
66	* (Initialization happens after skb_init is called.) */
67	#define AUDIT_DISABLED -1
68	#define AUDIT_UNINITIALIZED 0
69	#define AUDIT_INITIALIZED 1
70	static int audit_initialized;
71
72	#define AUDIT_OFF 0
73	#define AUDIT_ON 1
74	#define AUDIT_LOCKED 2
75	int audit_enabled;
76	int audit_ever_enabled;
77
78	/* Default state when kernel boots without any parameters. */
79	static int audit_default;
80
81	/* If auditing cannot proceed, audit_failure selects what happens. */
82	static int audit_failure = AUDIT_FAIL_PRINTK;
83
84	/*
85	* If audit records are to be written to the netlink socket, audit_pid
86	* contains the pid of the auditd process and audit_nlk_pid contains
87	* the pid to use to send netlink messages to that process.
88	*/
89	int audit_pid;
90	static int audit_nlk_pid;
91
92	/* If audit_rate_limit is non-zero, limit the rate of sending audit records
93	* to that number per second. This prevents DoS attacks, but results in
94	* audit records being dropped. */
95	static int audit_rate_limit;
96
97	/* Number of outstanding audit_buffers allowed. */
98	static int audit_backlog_limit = 64;
99	static int audit_backlog_wait_time = 60 * HZ;
100	static int audit_backlog_wait_overflow = 0;
101
102	/* The identity of the user shutting down the audit system. */
103	uid_t audit_sig_uid = -1;
104	pid_t audit_sig_pid = -1;
105	u32 audit_sig_sid = 0;
106
107	/* Records can be lost in several ways:
108	0) [suppressed in audit_alloc]
109	1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
110	2) out of memory in audit_log_move [alloc_skb]
111	3) suppressed due to audit_rate_limit
112	4) suppressed due to audit_backlog_limit
113	*/
114	static atomic_t audit_lost = ATOMIC_INIT(0);
115
116	/* The netlink socket. */
117	static struct sock *audit_sock;
118
119	/* Hash for inode-based rules */
120	struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
121
122	/* The audit_freelist is a list of pre-allocated audit buffers (if more
123	* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
124	* being placed on the freelist). */
125	static DEFINE_SPINLOCK(audit_freelist_lock);
126	static int audit_freelist_count;
127	static LIST_HEAD(audit_freelist);
128
129	static struct sk_buff_head audit_skb_queue;
130	/* queue of skbs to send to auditd when/if it comes back */
131	static struct sk_buff_head audit_skb_hold_queue;
132	static struct task_struct *kauditd_task;
133	static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
134	static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
135
136	/* Serialize requests from userspace. */
137	DEFINE_MUTEX(audit_cmd_mutex);
138
139	/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
140	* audit records. Since printk uses a 1024 byte buffer, this buffer
141	* should be at least that large. */
142	#define AUDIT_BUFSIZ 1024
143
144	/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
145	* audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
146	#define AUDIT_MAXFREE (2*NR_CPUS)
147
148	/* The audit_buffer is used when formatting an audit record. The caller
149	* locks briefly to get the record off the freelist or to allocate the
150	* buffer, and locks briefly to send the buffer to the netlink layer or
151	* to place it on a transmit queue. Multiple audit_buffers can be in
152	* use simultaneously. */
153	struct audit_buffer {
154	struct list_head list;
155	struct sk_buff skb; / formatted skb ready to send */
156	struct audit_context ctx; / NULL or associated context */
157	gfp_t gfp_mask;
158	};
159
160	struct audit_reply {
161	int pid;
162	struct sk_buff *skb;
163	};
164
165	static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
166	{
167	if (ab) {
168	struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
169	nlh->nlmsg_pid = pid;
170	}
171	}
172
173	void audit_panic(const char *message)
174	{
175	switch (audit_failure)
176	{
177	case AUDIT_FAIL_SILENT:
178	break;
179	case AUDIT_FAIL_PRINTK:
180	if (printk_ratelimit())
181	printk(KERN_ERR "audit: %s\n", message);
182	break;
183	case AUDIT_FAIL_PANIC:
184	/* test audit_pid since printk is always losey, why bother? */
185	if (audit_pid)
186	panic("audit: %s\n", message);
187	break;
188	}
189	}
190
191	static inline int audit_rate_check(void)
192	{
193	static unsigned long last_check = 0;
194	static int messages = 0;
195	static DEFINE_SPINLOCK(lock);
196	unsigned long flags;
197	unsigned long now;
198	unsigned long elapsed;
199	int retval = 0;
200
201	if (!audit_rate_limit) return 1;
202
203	spin_lock_irqsave(&lock, flags);
204	if (++messages < audit_rate_limit) {
205	retval = 1;
206	} else {
207	now = jiffies;
208	elapsed = now - last_check;
209	if (elapsed > HZ) {
210	last_check = now;
211	messages = 0;
212	retval = 1;
213	}
214	}
215	spin_unlock_irqrestore(&lock, flags);
216
217	return retval;
218	}
219
220	/**
221	* audit_log_lost - conditionally log lost audit message event
222	* @message: the message stating reason for lost audit message
223	*
224	* Emit at least 1 message per second, even if audit_rate_check is
225	* throttling.
226	* Always increment the lost messages counter.
227	*/
228	void audit_log_lost(const char *message)
229	{
230	static unsigned long last_msg = 0;
231	static DEFINE_SPINLOCK(lock);
232	unsigned long flags;
233	unsigned long now;
234	int print;
235
236	atomic_inc(&audit_lost);
237
238	print = (audit_failure == AUDIT_FAIL_PANIC \|\| !audit_rate_limit);
239
240	if (!print) {
241	spin_lock_irqsave(&lock, flags);
242	now = jiffies;
243	if (now - last_msg > HZ) {
244	print = 1;
245	last_msg = now;
246	}
247	spin_unlock_irqrestore(&lock, flags);
248	}
249
250	if (print) {
251	if (printk_ratelimit())
252	printk(KERN_WARNING
253	"audit: audit_lost=%d audit_rate_limit=%d "
254	"audit_backlog_limit=%d\n",
255	atomic_read(&audit_lost),
256	audit_rate_limit,
257	audit_backlog_limit);
258	audit_panic(message);
259	}
260	}
261
262	static int audit_log_config_change(char *function_name, int new, int old,
263	uid_t loginuid, u32 sessionid, u32 sid,
264	int allow_changes)
265	{
266	struct audit_buffer *ab;
267	int rc = 0;
268
269	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
270	audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
271	old, loginuid, sessionid);
272	if (sid) {
273	char *ctx = NULL;
274	u32 len;
275
276	rc = security_secid_to_secctx(sid, &ctx, &len);
277	if (rc) {
278	audit_log_format(ab, " sid=%u", sid);
279	allow_changes = 0; /* Something weird, deny request */
280	} else {
281	audit_log_format(ab, " subj=%s", ctx);
282	security_release_secctx(ctx, len);
283	}
284	}
285	audit_log_format(ab, " res=%d", allow_changes);
286	audit_log_end(ab);
287	return rc;
288	}
289
290	static int audit_do_config_change(char function_name, int to_change,
291	int new, uid_t loginuid, u32 sessionid,
292	u32 sid)
293	{
294	int allow_changes, rc = 0, old = *to_change;
295
296	/* check if we are locked */
297	if (audit_enabled == AUDIT_LOCKED)
298	allow_changes = 0;
299	else
300	allow_changes = 1;
301
302	if (audit_enabled != AUDIT_OFF) {
303	rc = audit_log_config_change(function_name, new, old, loginuid,
304	sessionid, sid, allow_changes);
305	if (rc)
306	allow_changes = 0;
307	}
308
309	/* If we are allowed, make the change */
310	if (allow_changes == 1)
311	*to_change = new;
312	/* Not allowed, update reason */
313	else if (rc == 0)
314	rc = -EPERM;
315	return rc;
316	}
317
318	static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
319	u32 sid)
320	{
321	return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
322	limit, loginuid, sessionid, sid);
323	}
324
325	static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
326	u32 sid)
327	{
328	return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
329	limit, loginuid, sessionid, sid);
330	}
331
332	static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
333	{
334	int rc;
335	if (state < AUDIT_OFF \|\| state > AUDIT_LOCKED)
336	return -EINVAL;
337
338	rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
339	loginuid, sessionid, sid);
340
341	if (!rc)
342	audit_ever_enabled \|= !!state;
343
344	return rc;
345	}
346
347	static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
348	{
349	if (state != AUDIT_FAIL_SILENT
350	&& state != AUDIT_FAIL_PRINTK
351	&& state != AUDIT_FAIL_PANIC)
352	return -EINVAL;
353
354	return audit_do_config_change("audit_failure", &audit_failure, state,
355	loginuid, sessionid, sid);
356	}
357
358	/*
359	* Queue skbs to be sent to auditd when/if it comes back. These skbs should
360	* already have been sent via prink/syslog and so if these messages are dropped
361	* it is not a huge concern since we already passed the audit_log_lost()
362	* notification and stuff. This is just nice to get audit messages during
363	* boot before auditd is running or messages generated while auditd is stopped.
364	* This only holds messages is audit_default is set, aka booting with audit=1
365	* or building your kernel that way.
366	*/
367	static void audit_hold_skb(struct sk_buff *skb)
368	{
369	if (audit_default &&
370	skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
371	skb_queue_tail(&audit_skb_hold_queue, skb);
372	else
373	kfree_skb(skb);
374	}
375
376	/*
377	* For one reason or another this nlh isn't getting delivered to the userspace
378	* audit daemon, just send it to printk.
379	*/
380	static void audit_printk_skb(struct sk_buff *skb)
381	{
382	struct nlmsghdr *nlh = nlmsg_hdr(skb);
383	char *data = NLMSG_DATA(nlh);
384
385	if (nlh->nlmsg_type != AUDIT_EOE) {
386	if (printk_ratelimit())
387	printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
388	else
389	audit_log_lost("printk limit exceeded\n");
390	}
391
392	audit_hold_skb(skb);
393	}
394
395	static void kauditd_send_skb(struct sk_buff *skb)
396	{
397	int err;
398	/* take a reference in case we can't send it and we want to hold it */
399	skb_get(skb);
400	err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
401	if (err < 0) {
402	BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
403	printk(KERN_ERR "audit: NO daemon at audit_pid=%d\n", audit_pid);
404	audit_log_lost("auditd dissapeared\n");
405	audit_pid = 0;
406	/* we might get lucky and get this in the next auditd */
407	audit_hold_skb(skb);
408	} else
409	/* drop the extra reference if sent ok */
410	kfree_skb(skb);
411	}
412
413	static int kauditd_thread(void *dummy)
414	{
415	struct sk_buff *skb;
416
417	set_freezable();
418	while (!kthread_should_stop()) {
419	/*
420	* if auditd just started drain the queue of messages already
421	* sent to syslog/printk. remember loss here is ok. we already
422	* called audit_log_lost() if it didn't go out normally. so the
423	* race between the skb_dequeue and the next check for audit_pid
424	* doesn't matter.
425	*
426	* if you ever find kauditd to be too slow we can get a perf win
427	* by doing our own locking and keeping better track if there
428	* are messages in this queue. I don't see the need now, but
429	* in 5 years when I want to play with this again I'll see this
430	* note and still have no friggin idea what i'm thinking today.
431	*/
432	if (audit_default && audit_pid) {
433	skb = skb_dequeue(&audit_skb_hold_queue);
434	if (unlikely(skb)) {
435	while (skb && audit_pid) {
436	kauditd_send_skb(skb);
437	skb = skb_dequeue(&audit_skb_hold_queue);
438	}
439	}
440	}
441
442	skb = skb_dequeue(&audit_skb_queue);
443	wake_up(&audit_backlog_wait);
444	if (skb) {
445	if (audit_pid)
446	kauditd_send_skb(skb);
447	else
448	audit_printk_skb(skb);
449	} else {
450	DECLARE_WAITQUEUE(wait, current);
451	set_current_state(TASK_INTERRUPTIBLE);
452	add_wait_queue(&kauditd_wait, &wait);
453
454	if (!skb_queue_len(&audit_skb_queue)) {
455	try_to_freeze();
456	schedule();
457	}
458
459	__set_current_state(TASK_RUNNING);
460	remove_wait_queue(&kauditd_wait, &wait);
461	}
462	}
463	return 0;
464	}
465
466	static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
467	{
468	struct task_struct *tsk;
469	int err;
470
471	read_lock(&tasklist_lock);
472	tsk = find_task_by_vpid(pid);
473	err = -ESRCH;
474	if (!tsk)
475	goto out;
476	err = 0;
477
478	spin_lock_irq(&tsk->sighand->siglock);
479	if (!tsk->signal->audit_tty)
480	err = -EPERM;
481	spin_unlock_irq(&tsk->sighand->siglock);
482	if (err)
483	goto out;
484
485	tty_audit_push_task(tsk, loginuid, sessionid);
486	out:
487	read_unlock(&tasklist_lock);
488	return err;
489	}
490
491	int audit_send_list(void *_dest)
492	{
493	struct audit_netlink_list *dest = _dest;
494	int pid = dest->pid;
495	struct sk_buff *skb;
496
497	/* wait for parent to finish and send an ACK */
498	mutex_lock(&audit_cmd_mutex);
499	mutex_unlock(&audit_cmd_mutex);
500
501	while ((skb = __skb_dequeue(&dest->q)) != NULL)
502	netlink_unicast(audit_sock, skb, pid, 0);
503
504	kfree(dest);
505
506	return 0;
507	}
508
509	struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
510	int multi, void *payload, int size)
511	{
512	struct sk_buff *skb;
513	struct nlmsghdr *nlh;
514	void *data;
515	int flags = multi ? NLM_F_MULTI : 0;
516	int t = done ? NLMSG_DONE : type;
517
518	skb = nlmsg_new(size, GFP_KERNEL);
519	if (!skb)
520	return NULL;
521
522	nlh = NLMSG_NEW(skb, pid, seq, t, size, flags);
523	data = NLMSG_DATA(nlh);
524	memcpy(data, payload, size);
525	return skb;
526
527	nlmsg_failure: /* Used by NLMSG_NEW */
528	if (skb)
529	kfree_skb(skb);
530	return NULL;
531	}
532
533	static int audit_send_reply_thread(void *arg)
534	{
535	struct audit_reply reply = (struct audit_reply )arg;
536
537	mutex_lock(&audit_cmd_mutex);
538	mutex_unlock(&audit_cmd_mutex);
539
540	/* Ignore failure. It'll only happen if the sender goes away,
541	because our timeout is set to infinite. */
542	netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
543	kfree(reply);
544	return 0;
545	}
546	/**
547	* audit_send_reply - send an audit reply message via netlink
548	* @pid: process id to send reply to
549	* @seq: sequence number
550	* @type: audit message type
551	* @done: done (last) flag
552	* @multi: multi-part message flag
553	* @payload: payload data
554	* @size: payload size
555	*
556	* Allocates an skb, builds the netlink message, and sends it to the pid.
557	* No failure notifications.
558	*/
559	void audit_send_reply(int pid, int seq, int type, int done, int multi,
560	void *payload, int size)
561	{
562	struct sk_buff *skb;
563	struct task_struct *tsk;
564	struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
565	GFP_KERNEL);
566
567	if (!reply)
568	return;
569
570	skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
571	if (!skb)
572	goto out;
573
574	reply->pid = pid;
575	reply->skb = skb;
576
577	tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
578	if (!IS_ERR(tsk))
579	return;
580	kfree_skb(skb);
581	out:
582	kfree(reply);
583	}
584
585	/*
586	* Check for appropriate CAP_AUDIT_ capabilities on incoming audit
587	* control messages.
588	*/
589	static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
590	{
591	int err = 0;
592
593	switch (msg_type) {
594	case AUDIT_GET:
595	case AUDIT_LIST:
596	case AUDIT_LIST_RULES:
597	case AUDIT_SET:
598	case AUDIT_ADD:
599	case AUDIT_ADD_RULE:
600	case AUDIT_DEL:
601	case AUDIT_DEL_RULE:
602	case AUDIT_SIGNAL_INFO:
603	case AUDIT_TTY_GET:
604	case AUDIT_TTY_SET:
605	case AUDIT_TRIM:
606	case AUDIT_MAKE_EQUIV:
607	if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
608	err = -EPERM;
609	break;
610	case AUDIT_USER:
611	case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
612	case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
613	if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
614	err = -EPERM;
615	break;
616	default: /* bad msg */
617	err = -EINVAL;
618	}
619
620	return err;
621	}
622
623	static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
624	u32 pid, u32 uid, uid_t auid, u32 ses,
625	u32 sid)
626	{
627	int rc = 0;
628	char *ctx = NULL;
629	u32 len;
630
631	if (!audit_enabled) {
632	*ab = NULL;
633	return rc;
634	}
635
636	*ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
637	audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
638	pid, uid, auid, ses);
639	if (sid) {
640	rc = security_secid_to_secctx(sid, &ctx, &len);
641	if (rc)
642	audit_log_format(*ab, " ssid=%u", sid);
643	else {
644	audit_log_format(*ab, " subj=%s", ctx);
645	security_release_secctx(ctx, len);
646	}
647	}
648
649	return rc;
650	}
651
652	static int audit_receive_msg(struct sk_buff skb, struct nlmsghdr nlh)
653	{
654	u32 uid, pid, seq, sid;
655	void *data;
656	struct audit_status *status_get, status_set;
657	int err;
658	struct audit_buffer *ab;
659	u16 msg_type = nlh->nlmsg_type;
660	uid_t loginuid; /* loginuid of sender */
661	u32 sessionid;
662	struct audit_sig_info *sig_data;
663	char *ctx = NULL;
664	u32 len;
665
666	err = audit_netlink_ok(skb, msg_type);
667	if (err)
668	return err;
669
670	/* As soon as there's any sign of userspace auditd,
671	* start kauditd to talk to it */
672	if (!kauditd_task)
673	kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
674	if (IS_ERR(kauditd_task)) {
675	err = PTR_ERR(kauditd_task);
676	kauditd_task = NULL;
677	return err;
678	}
679
680	pid = NETLINK_CREDS(skb)->pid;
681	uid = NETLINK_CREDS(skb)->uid;
682	loginuid = NETLINK_CB(skb).loginuid;
683	sessionid = NETLINK_CB(skb).sessionid;
684	sid = NETLINK_CB(skb).sid;
685	seq = nlh->nlmsg_seq;
686	data = NLMSG_DATA(nlh);
687
688	switch (msg_type) {
689	case AUDIT_GET:
690	status_set.enabled = audit_enabled;
691	status_set.failure = audit_failure;
692	status_set.pid = audit_pid;
693	status_set.rate_limit = audit_rate_limit;
694	status_set.backlog_limit = audit_backlog_limit;
695	status_set.lost = atomic_read(&audit_lost);
696	status_set.backlog = skb_queue_len(&audit_skb_queue);
697	audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
698	&status_set, sizeof(status_set));
699	break;
700	case AUDIT_SET:
701	if (nlh->nlmsg_len < sizeof(struct audit_status))
702	return -EINVAL;
703	status_get = (struct audit_status *)data;
704	if (status_get->mask & AUDIT_STATUS_ENABLED) {
705	err = audit_set_enabled(status_get->enabled,
706	loginuid, sessionid, sid);
707	if (err < 0)
708	return err;
709	}
710	if (status_get->mask & AUDIT_STATUS_FAILURE) {
711	err = audit_set_failure(status_get->failure,
712	loginuid, sessionid, sid);
713	if (err < 0)
714	return err;
715	}
716	if (status_get->mask & AUDIT_STATUS_PID) {
717	int new_pid = status_get->pid;
718
719	if (audit_enabled != AUDIT_OFF)
720	audit_log_config_change("audit_pid", new_pid,
721	audit_pid, loginuid,
722	sessionid, sid, 1);
723
724	audit_pid = new_pid;
725	audit_nlk_pid = NETLINK_CB(skb).pid;
726	}
727	if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
728	err = audit_set_rate_limit(status_get->rate_limit,
729	loginuid, sessionid, sid);
730	if (err < 0)
731	return err;
732	}
733	if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
734	err = audit_set_backlog_limit(status_get->backlog_limit,
735	loginuid, sessionid, sid);
736	break;
737	case AUDIT_USER:
738	case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
739	case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
740	if (!audit_enabled && msg_type != AUDIT_USER_AVC)
741	return 0;
742
743	err = audit_filter_user(&NETLINK_CB(skb));
744	if (err == 1) {
745	err = 0;
746	if (msg_type == AUDIT_USER_TTY) {
747	err = audit_prepare_user_tty(pid, loginuid,
748	sessionid);
749	if (err)
750	break;
751	}
752	audit_log_common_recv_msg(&ab, msg_type, pid, uid,
753	loginuid, sessionid, sid);
754
755	if (msg_type != AUDIT_USER_TTY)
756	audit_log_format(ab, " msg='%.1024s'",
757	(char *)data);
758	else {
759	int size;
760
761	audit_log_format(ab, " msg=");
762	size = nlmsg_len(nlh);
763	if (size > 0 &&
764	((unsigned char *)data)[size - 1] == '\0')
765	size--;
766	audit_log_n_untrustedstring(ab, data, size);
767	}
768	audit_set_pid(ab, pid);
769	audit_log_end(ab);
770	}
771	break;
772	case AUDIT_ADD:
773	case AUDIT_DEL:
774	if (nlmsg_len(nlh) < sizeof(struct audit_rule))
775	return -EINVAL;
776	if (audit_enabled == AUDIT_LOCKED) {
777	audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
778	uid, loginuid, sessionid, sid);
779
780	audit_log_format(ab, " audit_enabled=%d res=0",
781	audit_enabled);
782	audit_log_end(ab);
783	return -EPERM;
784	}
785	/* fallthrough */
786	case AUDIT_LIST:
787	err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
788	uid, seq, data, nlmsg_len(nlh),
789	loginuid, sessionid, sid);
790	break;
791	case AUDIT_ADD_RULE:
792	case AUDIT_DEL_RULE:
793	if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
794	return -EINVAL;
795	if (audit_enabled == AUDIT_LOCKED) {
796	audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
797	uid, loginuid, sessionid, sid);
798
799	audit_log_format(ab, " audit_enabled=%d res=0",
800	audit_enabled);
801	audit_log_end(ab);
802	return -EPERM;
803	}
804	/* fallthrough */
805	case AUDIT_LIST_RULES:
806	err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
807	uid, seq, data, nlmsg_len(nlh),
808	loginuid, sessionid, sid);
809	break;
810	case AUDIT_TRIM:
811	audit_trim_trees();
812
813	audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
814	uid, loginuid, sessionid, sid);
815
816	audit_log_format(ab, " op=trim res=1");
817	audit_log_end(ab);
818	break;
819	case AUDIT_MAKE_EQUIV: {
820	void *bufp = data;
821	u32 sizes[2];
822	size_t msglen = nlmsg_len(nlh);
823	char old, new;
824
825	err = -EINVAL;
826	if (msglen < 2 * sizeof(u32))
827	break;
828	memcpy(sizes, bufp, 2 * sizeof(u32));
829	bufp += 2 * sizeof(u32);
830	msglen -= 2 * sizeof(u32);
831	old = audit_unpack_string(&bufp, &msglen, sizes[0]);
832	if (IS_ERR(old)) {
833	err = PTR_ERR(old);
834	break;
835	}
836	new = audit_unpack_string(&bufp, &msglen, sizes[1]);
837	if (IS_ERR(new)) {
838	err = PTR_ERR(new);
839	kfree(old);
840	break;
841	}
842	/* OK, here comes... */
843	err = audit_tag_tree(old, new);
844
845	audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
846	uid, loginuid, sessionid, sid);
847
848	audit_log_format(ab, " op=make_equiv old=");
849	audit_log_untrustedstring(ab, old);
850	audit_log_format(ab, " new=");
851	audit_log_untrustedstring(ab, new);
852	audit_log_format(ab, " res=%d", !err);
853	audit_log_end(ab);
854	kfree(old);
855	kfree(new);
856	break;
857	}
858	case AUDIT_SIGNAL_INFO:
859	len = 0;
860	if (audit_sig_sid) {
861	err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
862	if (err)
863	return err;
864	}
865	sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
866	if (!sig_data) {
867	if (audit_sig_sid)
868	security_release_secctx(ctx, len);
869	return -ENOMEM;
870	}
871	sig_data->uid = audit_sig_uid;
872	sig_data->pid = audit_sig_pid;
873	if (audit_sig_sid) {
874	memcpy(sig_data->ctx, ctx, len);
875	security_release_secctx(ctx, len);
876	}
877	audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
878	0, 0, sig_data, sizeof(*sig_data) + len);
879	kfree(sig_data);
880	break;
881	case AUDIT_TTY_GET: {
882	struct audit_tty_status s;
883	struct task_struct *tsk;
884
885	read_lock(&tasklist_lock);
886	tsk = find_task_by_vpid(pid);
887	if (!tsk)
888	err = -ESRCH;
889	else {
890	spin_lock_irq(&tsk->sighand->siglock);
891	s.enabled = tsk->signal->audit_tty != 0;
892	spin_unlock_irq(&tsk->sighand->siglock);
893	}
894	read_unlock(&tasklist_lock);
895	audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
896	&s, sizeof(s));
897	break;
898	}
899	case AUDIT_TTY_SET: {
900	struct audit_tty_status *s;
901	struct task_struct *tsk;
902
903	if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
904	return -EINVAL;
905	s = data;
906	if (s->enabled != 0 && s->enabled != 1)
907	return -EINVAL;
908	read_lock(&tasklist_lock);
909	tsk = find_task_by_vpid(pid);
910	if (!tsk)
911	err = -ESRCH;
912	else {
913	spin_lock_irq(&tsk->sighand->siglock);
914	tsk->signal->audit_tty = s->enabled != 0;
915	spin_unlock_irq(&tsk->sighand->siglock);
916	}
917	read_unlock(&tasklist_lock);
918	break;
919	}
920	default:
921	err = -EINVAL;
922	break;
923	}
924
925	return err < 0 ? err : 0;
926	}
927
928	/*
929	* Get message from skb. Each message is processed by audit_receive_msg.
930	* Malformed skbs with wrong length are discarded silently.
931	*/
932	static void audit_receive_skb(struct sk_buff *skb)
933	{
934	struct nlmsghdr *nlh;
935	/*
936	* len MUST be signed for NLMSG_NEXT to be able to dec it below 0
937	* if the nlmsg_len was not aligned
938	*/
939	int len;
940	int err;
941
942	nlh = nlmsg_hdr(skb);
943	len = skb->len;
944
945	while (NLMSG_OK(nlh, len)) {
946	err = audit_receive_msg(skb, nlh);
947	/* if err or if this message says it wants a response */
948	if (err \|\| (nlh->nlmsg_flags & NLM_F_ACK))
949	netlink_ack(skb, nlh, err);
950
951	nlh = NLMSG_NEXT(nlh, len);
952	}
953	}
954
955	/* Receive messages from netlink socket. */
956	static void audit_receive(struct sk_buff *skb)
957	{
958	mutex_lock(&audit_cmd_mutex);
959	audit_receive_skb(skb);
960	mutex_unlock(&audit_cmd_mutex);
961	}
962
963	/* Initialize audit support at boot time. */
964	static int __init audit_init(void)
965	{
966	int i;
967
968	if (audit_initialized == AUDIT_DISABLED)
969	return 0;
970
971	printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
972	audit_default ? "enabled" : "disabled");
973	audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
974	audit_receive, NULL, THIS_MODULE);
975	if (!audit_sock)
976	audit_panic("cannot initialize netlink socket");
977	else
978	audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
979
980	skb_queue_head_init(&audit_skb_queue);
981	skb_queue_head_init(&audit_skb_hold_queue);
982	audit_initialized = AUDIT_INITIALIZED;
983	audit_enabled = audit_default;
984	audit_ever_enabled \|= !!audit_default;
985
986	audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
987
988	for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
989	INIT_LIST_HEAD(&audit_inode_hash[i]);
990
991	return 0;
992	}
993	__initcall(audit_init);
994
995	/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
996	static int __init audit_enable(char *str)
997	{
998	audit_default = !!simple_strtol(str, NULL, 0);
999	if (!audit_default)
1000	audit_initialized = AUDIT_DISABLED;
1001
1002	printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
1003
1004	if (audit_initialized == AUDIT_INITIALIZED) {
1005	audit_enabled = audit_default;
1006	audit_ever_enabled \|= !!audit_default;
1007	} else if (audit_initialized == AUDIT_UNINITIALIZED) {
1008	printk(" (after initialization)");
1009	} else {
1010	printk(" (until reboot)");
1011	}
1012	printk("\n");
1013
1014	return 1;
1015	}
1016
1017	__setup("audit=", audit_enable);
1018
1019	static void audit_buffer_free(struct audit_buffer *ab)
1020	{
1021	unsigned long flags;
1022
1023	if (!ab)
1024	return;
1025
1026	if (ab->skb)
1027	kfree_skb(ab->skb);
1028
1029	spin_lock_irqsave(&audit_freelist_lock, flags);
1030	if (audit_freelist_count > AUDIT_MAXFREE)
1031	kfree(ab);
1032	else {
1033	audit_freelist_count++;
1034	list_add(&ab->list, &audit_freelist);
1035	}
1036	spin_unlock_irqrestore(&audit_freelist_lock, flags);
1037	}
1038
1039	static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1040	gfp_t gfp_mask, int type)
1041	{
1042	unsigned long flags;
1043	struct audit_buffer *ab = NULL;
1044	struct nlmsghdr *nlh;
1045
1046	spin_lock_irqsave(&audit_freelist_lock, flags);
1047	if (!list_empty(&audit_freelist)) {
1048	ab = list_entry(audit_freelist.next,
1049	struct audit_buffer, list);
1050	list_del(&ab->list);
1051	--audit_freelist_count;
1052	}
1053	spin_unlock_irqrestore(&audit_freelist_lock, flags);
1054
1055	if (!ab) {
1056	ab = kmalloc(sizeof(*ab), gfp_mask);
1057	if (!ab)
1058	goto err;
1059	}
1060
1061	ab->ctx = ctx;
1062	ab->gfp_mask = gfp_mask;
1063
1064	ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1065	if (!ab->skb)
1066	goto nlmsg_failure;
1067
1068	nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0);
1069
1070	return ab;
1071
1072	nlmsg_failure: /* Used by NLMSG_NEW */
1073	kfree_skb(ab->skb);
1074	ab->skb = NULL;
1075	err:
1076	audit_buffer_free(ab);
1077	return NULL;
1078	}
1079
1080	/**
1081	* audit_serial - compute a serial number for the audit record
1082	*
1083	* Compute a serial number for the audit record. Audit records are
1084	* written to user-space as soon as they are generated, so a complete
1085	* audit record may be written in several pieces. The timestamp of the
1086	* record and this serial number are used by the user-space tools to
1087	* determine which pieces belong to the same audit record. The
1088	* (timestamp,serial) tuple is unique for each syscall and is live from
1089	* syscall entry to syscall exit.
1090	*
1091	* NOTE: Another possibility is to store the formatted records off the
1092	* audit context (for those records that have a context), and emit them
1093	* all at syscall exit. However, this could delay the reporting of
1094	* significant errors until syscall exit (or never, if the system
1095	* halts).
1096	*/
1097	unsigned int audit_serial(void)
1098	{
1099	static DEFINE_SPINLOCK(serial_lock);
1100	static unsigned int serial = 0;
1101
1102	unsigned long flags;
1103	unsigned int ret;
1104
1105	spin_lock_irqsave(&serial_lock, flags);
1106	do {
1107	ret = ++serial;
1108	} while (unlikely(!ret));
1109	spin_unlock_irqrestore(&serial_lock, flags);
1110
1111	return ret;
1112	}
1113
1114	static inline void audit_get_stamp(struct audit_context *ctx,
1115	struct timespec t, unsigned int serial)
1116	{
1117	if (!ctx \|\| !auditsc_get_stamp(ctx, t, serial)) {
1118	*t = CURRENT_TIME;
1119	*serial = audit_serial();
1120	}
1121	}
1122
1123	/* Obtain an audit buffer. This routine does locking to obtain the
1124	* audit buffer, but then no locking is required for calls to
1125	* audit_log_*format. If the tsk is a task that is currently in a
1126	* syscall, then the syscall is marked as auditable and an audit record
1127	* will be written at syscall exit. If there is no associated task, tsk
1128	* should be NULL. */
1129
1130	/**
1131	* audit_log_start - obtain an audit buffer
1132	* @ctx: audit_context (may be NULL)
1133	* @gfp_mask: type of allocation
1134	* @type: audit message type
1135	*
1136	* Returns audit_buffer pointer on success or NULL on error.
1137	*
1138	* Obtain an audit buffer. This routine does locking to obtain the
1139	* audit buffer, but then no locking is required for calls to
1140	* audit_log_*format. If the task (ctx) is a task that is currently in a
1141	* syscall, then the syscall is marked as auditable and an audit record
1142	* will be written at syscall exit. If there is no associated task, then
1143	* task context (ctx) should be NULL.
1144	*/
1145	struct audit_buffer audit_log_start(struct audit_context ctx, gfp_t gfp_mask,
1146	int type)
1147	{
1148	struct audit_buffer *ab = NULL;
1149	struct timespec t;
1150	unsigned int uninitialized_var(serial);
1151	int reserve;
1152	unsigned long timeout_start = jiffies;
1153
1154	if (audit_initialized != AUDIT_INITIALIZED)
1155	return NULL;
1156
1157	if (unlikely(audit_filter_type(type)))
1158	return NULL;
1159
1160	if (gfp_mask & __GFP_WAIT)
1161	reserve = 0;
1162	else
1163	reserve = 5; /* Allow atomic callers to go up to five
1164	entries over the normal backlog limit */
1165
1166	while (audit_backlog_limit
1167	&& skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1168	if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1169	&& time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1170
1171	/* Wait for auditd to drain the queue a little */
1172	DECLARE_WAITQUEUE(wait, current);
1173	set_current_state(TASK_INTERRUPTIBLE);
1174	add_wait_queue(&audit_backlog_wait, &wait);
1175
1176	if (audit_backlog_limit &&
1177	skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1178	schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
1179
1180	__set_current_state(TASK_RUNNING);
1181	remove_wait_queue(&audit_backlog_wait, &wait);
1182	continue;
1183	}
1184	if (audit_rate_check() && printk_ratelimit())
1185	printk(KERN_WARNING
1186	"audit: audit_backlog=%d > "
1187	"audit_backlog_limit=%d\n",
1188	skb_queue_len(&audit_skb_queue),
1189	audit_backlog_limit);
1190	audit_log_lost("backlog limit exceeded");
1191	audit_backlog_wait_time = audit_backlog_wait_overflow;
1192	wake_up(&audit_backlog_wait);
1193	return NULL;
1194	}
1195
1196	ab = audit_buffer_alloc(ctx, gfp_mask, type);
1197	if (!ab) {
1198	audit_log_lost("out of memory in audit_log_start");
1199	return NULL;
1200	}
1201
1202	audit_get_stamp(ab->ctx, &t, &serial);
1203
1204	audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1205	t.tv_sec, t.tv_nsec/1000000, serial);
1206	return ab;
1207	}
1208
1209	/**
1210	* audit_expand - expand skb in the audit buffer
1211	* @ab: audit_buffer
1212	* @extra: space to add at tail of the skb
1213	*
1214	* Returns 0 (no space) on failed expansion, or available space if
1215	* successful.
1216	*/
1217	static inline int audit_expand(struct audit_buffer *ab, int extra)
1218	{
1219	struct sk_buff *skb = ab->skb;
1220	int oldtail = skb_tailroom(skb);
1221	int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1222	int newtail = skb_tailroom(skb);
1223
1224	if (ret < 0) {
1225	audit_log_lost("out of memory in audit_expand");
1226	return 0;
1227	}
1228
1229	skb->truesize += newtail - oldtail;
1230	return newtail;
1231	}
1232
1233	/*
1234	* Format an audit message into the audit buffer. If there isn't enough
1235	* room in the audit buffer, more room will be allocated and vsnprint
1236	* will be called a second time. Currently, we assume that a printk
1237	* can't format message larger than 1024 bytes, so we don't either.
1238	*/
1239	static void audit_log_vformat(struct audit_buffer ab, const char fmt,
1240	va_list args)
1241	{
1242	int len, avail;
1243	struct sk_buff *skb;
1244	va_list args2;
1245
1246	if (!ab)
1247	return;
1248
1249	BUG_ON(!ab->skb);
1250	skb = ab->skb;
1251	avail = skb_tailroom(skb);
1252	if (avail == 0) {
1253	avail = audit_expand(ab, AUDIT_BUFSIZ);
1254	if (!avail)
1255	goto out;
1256	}
1257	va_copy(args2, args);
1258	len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1259	if (len >= avail) {
1260	/* The printk buffer is 1024 bytes long, so if we get
1261	* here and AUDIT_BUFSIZ is at least 1024, then we can
1262	* log everything that printk could have logged. */
1263	avail = audit_expand(ab,
1264	max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1265	if (!avail)
1266	goto out;
1267	len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1268	}
1269	va_end(args2);
1270	if (len > 0)
1271	skb_put(skb, len);
1272	out:
1273	return;
1274	}
1275
1276	/**
1277	* audit_log_format - format a message into the audit buffer.
1278	* @ab: audit_buffer
1279	* @fmt: format string
1280	* @...: optional parameters matching @fmt string
1281	*
1282	* All the work is done in audit_log_vformat.
1283	*/
1284	void audit_log_format(struct audit_buffer ab, const char fmt, ...)
1285	{
1286	va_list args;
1287
1288	if (!ab)
1289	return;
1290	va_start(args, fmt);
1291	audit_log_vformat(ab, fmt, args);
1292	va_end(args);
1293	}
1294
1295	/**
1296	* audit_log_hex - convert a buffer to hex and append it to the audit skb
1297	* @ab: the audit_buffer
1298	* @buf: buffer to convert to hex
1299	* @len: length of @buf to be converted
1300	*
1301	* No return value; failure to expand is silently ignored.
1302	*
1303	* This function will take the passed buf and convert it into a string of
1304	* ascii hex digits. The new string is placed onto the skb.
1305	*/
1306	void audit_log_n_hex(struct audit_buffer ab, const unsigned char buf,
1307	size_t len)
1308	{
1309	int i, avail, new_len;
1310	unsigned char *ptr;
1311	struct sk_buff *skb;
1312	static const unsigned char *hex = "0123456789ABCDEF";
1313
1314	if (!ab)
1315	return;
1316
1317	BUG_ON(!ab->skb);
1318	skb = ab->skb;
1319	avail = skb_tailroom(skb);
1320	new_len = len<<1;
1321	if (new_len >= avail) {
1322	/* Round the buffer request up to the next multiple */
1323	new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1324	avail = audit_expand(ab, new_len);
1325	if (!avail)
1326	return;
1327	}
1328
1329	ptr = skb_tail_pointer(skb);
1330	for (i=0; i<len; i++) {
1331	ptr++ = hex[(buf[i] & 0xF0)>>4]; / Upper nibble */
1332	ptr++ = hex[buf[i] & 0x0F]; / Lower nibble */
1333	}
1334	*ptr = 0;
1335	skb_put(skb, len << 1); /* new string is twice the old string */
1336	}
1337
1338	/*
1339	* Format a string of no more than slen characters into the audit buffer,
1340	* enclosed in quote marks.
1341	*/
1342	void audit_log_n_string(struct audit_buffer ab, const char string,
1343	size_t slen)
1344	{
1345	int avail, new_len;
1346	unsigned char *ptr;
1347	struct sk_buff *skb;
1348
1349	if (!ab)
1350	return;
1351
1352	BUG_ON(!ab->skb);
1353	skb = ab->skb;
1354	avail = skb_tailroom(skb);
1355	new_len = slen + 3; /* enclosing quotes + null terminator */
1356	if (new_len > avail) {
1357	avail = audit_expand(ab, new_len);
1358	if (!avail)
1359	return;
1360	}
1361	ptr = skb_tail_pointer(skb);
1362	*ptr++ = '"';
1363	memcpy(ptr, string, slen);
1364	ptr += slen;
1365	*ptr++ = '"';
1366	*ptr = 0;
1367	skb_put(skb, slen + 2); /* don't include null terminator */
1368	}
1369
1370	/**
1371	* audit_string_contains_control - does a string need to be logged in hex
1372	* @string: string to be checked
1373	* @len: max length of the string to check
1374	*/
1375	int audit_string_contains_control(const char *string, size_t len)
1376	{
1377	const unsigned char *p;
1378	for (p = string; p < (const unsigned char *)string + len; p++) {
1379	if (p == '"' \|\| p < 0x21 \|\| *p > 0x7e)
1380	return 1;
1381	}
1382	return 0;
1383	}
1384
1385	/**
1386	* audit_log_n_untrustedstring - log a string that may contain random characters
1387	* @ab: audit_buffer
1388	* @len: length of string (not including trailing null)
1389	* @string: string to be logged
1390	*
1391	* This code will escape a string that is passed to it if the string
1392	* contains a control character, unprintable character, double quote mark,
1393	* or a space. Unescaped strings will start and end with a double quote mark.
1394	* Strings that are escaped are printed in hex (2 digits per char).
1395	*
1396	* The caller specifies the number of characters in the string to log, which may
1397	* or may not be the entire string.
1398	*/
1399	void audit_log_n_untrustedstring(struct audit_buffer ab, const char string,
1400	size_t len)
1401	{
1402	if (audit_string_contains_control(string, len))
1403	audit_log_n_hex(ab, string, len);
1404	else
1405	audit_log_n_string(ab, string, len);
1406	}
1407
1408	/**
1409	* audit_log_untrustedstring - log a string that may contain random characters
1410	* @ab: audit_buffer
1411	* @string: string to be logged
1412	*
1413	* Same as audit_log_n_untrustedstring(), except that strlen is used to
1414	* determine string length.
1415	*/
1416	void audit_log_untrustedstring(struct audit_buffer ab, const char string)
1417	{
1418	audit_log_n_untrustedstring(ab, string, strlen(string));
1419	}
1420
1421	/* This is a helper-function to print the escaped d_path */
1422	void audit_log_d_path(struct audit_buffer ab, const char prefix,
1423	struct path *path)
1424	{
1425	char p, pathname;
1426
1427	if (prefix)
1428	audit_log_format(ab, " %s", prefix);
1429
1430	/* We will allow 11 spaces for ' (deleted)' to be appended */
1431	pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1432	if (!pathname) {
1433	audit_log_string(ab, "<no_memory>");
1434	return;
1435	}
1436	p = d_path(path, pathname, PATH_MAX+11);
1437	if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1438	/* FIXME: can we save some information here? */
1439	audit_log_string(ab, "<too_long>");
1440	} else
1441	audit_log_untrustedstring(ab, p);
1442	kfree(pathname);
1443	}
1444
1445	void audit_log_key(struct audit_buffer ab, char key)
1446	{
1447	audit_log_format(ab, " key=");
1448	if (key)
1449	audit_log_untrustedstring(ab, key);
1450	else
1451	audit_log_format(ab, "(null)");
1452	}
1453
1454	/**
1455	* audit_log_end - end one audit record
1456	* @ab: the audit_buffer
1457	*
1458	* The netlink_* functions cannot be called inside an irq context, so
1459	* the audit buffer is placed on a queue and a tasklet is scheduled to
1460	* remove them from the queue outside the irq context. May be called in
1461	* any context.
1462	*/
1463	void audit_log_end(struct audit_buffer *ab)
1464	{
1465	if (!ab)
1466	return;
1467	if (!audit_rate_check()) {
1468	audit_log_lost("rate limit exceeded");
1469	} else {
1470	struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1471	nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1472
1473	if (audit_pid) {
1474	skb_queue_tail(&audit_skb_queue, ab->skb);
1475	wake_up_interruptible(&kauditd_wait);
1476	} else {
1477	audit_printk_skb(ab->skb);
1478	}
1479	ab->skb = NULL;
1480	}
1481	audit_buffer_free(ab);
1482	}
1483
1484	/**
1485	* audit_log - Log an audit record
1486	* @ctx: audit context
1487	* @gfp_mask: type of allocation
1488	* @type: audit message type
1489	* @fmt: format string to use
1490	* @...: variable parameters matching the format string
1491	*
1492	* This is a convenience function that calls audit_log_start,
1493	* audit_log_vformat, and audit_log_end. It may be called
1494	* in any context.
1495	*/
1496	void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1497	const char *fmt, ...)
1498	{
1499	struct audit_buffer *ab;
1500	va_list args;
1501
1502	ab = audit_log_start(ctx, gfp_mask, type);
1503	if (ab) {
1504	va_start(args, fmt);
1505	audit_log_vformat(ab, fmt, args);
1506	va_end(args);
1507	audit_log_end(ab);
1508	}
1509	}
1510
1511	EXPORT_SYMBOL(audit_log_start);
1512	EXPORT_SYMBOL(audit_log_end);
1513	EXPORT_SYMBOL(audit_log_format);
1514	EXPORT_SYMBOL(audit_log);
1515

Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9

Kernel

Kernel Git Source Tree

Root/kernel/audit.c

interactive