Commit | Line | Data |
---|---|---|
85c8721f | 1 | /* audit.c -- Auditing support |
1da177e4 LT |
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 2003-2004 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 SELinux. | |
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 | * | |
85c8721f | 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
1da177e4 LT |
42 | */ |
43 | ||
44 | #include <linux/init.h> | |
1da177e4 | 45 | #include <asm/types.h> |
715b49ef | 46 | #include <asm/atomic.h> |
1da177e4 LT |
47 | #include <linux/mm.h> |
48 | #include <linux/module.h> | |
b7d11258 DW |
49 | #include <linux/err.h> |
50 | #include <linux/kthread.h> | |
1da177e4 LT |
51 | |
52 | #include <linux/audit.h> | |
53 | ||
54 | #include <net/sock.h> | |
93315ed6 | 55 | #include <net/netlink.h> |
1da177e4 LT |
56 | #include <linux/skbuff.h> |
57 | #include <linux/netlink.h> | |
3dc7e315 DG |
58 | #include <linux/selinux.h> |
59 | ||
60 | #include "audit.h" | |
1da177e4 LT |
61 | |
62 | /* No auditing will take place until audit_initialized != 0. | |
63 | * (Initialization happens after skb_init is called.) */ | |
64 | static int audit_initialized; | |
65 | ||
66 | /* No syscall auditing will take place unless audit_enabled != 0. */ | |
67 | int audit_enabled; | |
68 | ||
69 | /* Default state when kernel boots without any parameters. */ | |
70 | static int audit_default; | |
71 | ||
72 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
73 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
74 | ||
75 | /* If audit records are to be written to the netlink socket, audit_pid | |
76 | * contains the (non-zero) pid. */ | |
c2f0c7c3 | 77 | int audit_pid; |
1da177e4 | 78 | |
b0dd25a8 | 79 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
80 | * to that number per second. This prevents DoS attacks, but results in |
81 | * audit records being dropped. */ | |
82 | static int audit_rate_limit; | |
83 | ||
84 | /* Number of outstanding audit_buffers allowed. */ | |
85 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
86 | static int audit_backlog_wait_time = 60 * HZ; |
87 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 88 | |
c2f0c7c3 SG |
89 | /* The identity of the user shutting down the audit system. */ |
90 | uid_t audit_sig_uid = -1; | |
91 | pid_t audit_sig_pid = -1; | |
e1396065 | 92 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 93 | |
1da177e4 LT |
94 | /* Records can be lost in several ways: |
95 | 0) [suppressed in audit_alloc] | |
96 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
97 | 2) out of memory in audit_log_move [alloc_skb] | |
98 | 3) suppressed due to audit_rate_limit | |
99 | 4) suppressed due to audit_backlog_limit | |
100 | */ | |
101 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
102 | ||
103 | /* The netlink socket. */ | |
104 | static struct sock *audit_sock; | |
105 | ||
b7d11258 | 106 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
107 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
108 | * being placed on the freelist). */ | |
1da177e4 | 109 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 110 | static int audit_freelist_count; |
1da177e4 LT |
111 | static LIST_HEAD(audit_freelist); |
112 | ||
b7d11258 DW |
113 | static struct sk_buff_head audit_skb_queue; |
114 | static struct task_struct *kauditd_task; | |
115 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 116 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 LT |
117 | |
118 | /* The netlink socket is only to be read by 1 CPU, which lets us assume | |
23f32d18 | 119 | * that list additions and deletions never happen simultaneously in |
1da177e4 | 120 | * auditsc.c */ |
5a0bbce5 | 121 | DEFINE_MUTEX(audit_netlink_mutex); |
1da177e4 LT |
122 | |
123 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
124 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
125 | * should be at least that large. */ | |
126 | #define AUDIT_BUFSIZ 1024 | |
127 | ||
128 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
129 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
130 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
131 | ||
132 | /* The audit_buffer is used when formatting an audit record. The caller | |
133 | * locks briefly to get the record off the freelist or to allocate the | |
134 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
135 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
136 | * use simultaneously. */ | |
137 | struct audit_buffer { | |
138 | struct list_head list; | |
8fc6115c | 139 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 140 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 141 | gfp_t gfp_mask; |
1da177e4 LT |
142 | }; |
143 | ||
c0404993 SG |
144 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
145 | { | |
146 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; | |
147 | nlh->nlmsg_pid = pid; | |
148 | } | |
149 | ||
8c8570fb | 150 | void audit_panic(const char *message) |
1da177e4 LT |
151 | { |
152 | switch (audit_failure) | |
153 | { | |
154 | case AUDIT_FAIL_SILENT: | |
155 | break; | |
156 | case AUDIT_FAIL_PRINTK: | |
157 | printk(KERN_ERR "audit: %s\n", message); | |
158 | break; | |
159 | case AUDIT_FAIL_PANIC: | |
160 | panic("audit: %s\n", message); | |
161 | break; | |
162 | } | |
163 | } | |
164 | ||
165 | static inline int audit_rate_check(void) | |
166 | { | |
167 | static unsigned long last_check = 0; | |
168 | static int messages = 0; | |
169 | static DEFINE_SPINLOCK(lock); | |
170 | unsigned long flags; | |
171 | unsigned long now; | |
172 | unsigned long elapsed; | |
173 | int retval = 0; | |
174 | ||
175 | if (!audit_rate_limit) return 1; | |
176 | ||
177 | spin_lock_irqsave(&lock, flags); | |
178 | if (++messages < audit_rate_limit) { | |
179 | retval = 1; | |
180 | } else { | |
181 | now = jiffies; | |
182 | elapsed = now - last_check; | |
183 | if (elapsed > HZ) { | |
184 | last_check = now; | |
185 | messages = 0; | |
186 | retval = 1; | |
187 | } | |
188 | } | |
189 | spin_unlock_irqrestore(&lock, flags); | |
190 | ||
191 | return retval; | |
192 | } | |
193 | ||
b0dd25a8 RD |
194 | /** |
195 | * audit_log_lost - conditionally log lost audit message event | |
196 | * @message: the message stating reason for lost audit message | |
197 | * | |
198 | * Emit at least 1 message per second, even if audit_rate_check is | |
199 | * throttling. | |
200 | * Always increment the lost messages counter. | |
201 | */ | |
1da177e4 LT |
202 | void audit_log_lost(const char *message) |
203 | { | |
204 | static unsigned long last_msg = 0; | |
205 | static DEFINE_SPINLOCK(lock); | |
206 | unsigned long flags; | |
207 | unsigned long now; | |
208 | int print; | |
209 | ||
210 | atomic_inc(&audit_lost); | |
211 | ||
212 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
213 | ||
214 | if (!print) { | |
215 | spin_lock_irqsave(&lock, flags); | |
216 | now = jiffies; | |
217 | if (now - last_msg > HZ) { | |
218 | print = 1; | |
219 | last_msg = now; | |
220 | } | |
221 | spin_unlock_irqrestore(&lock, flags); | |
222 | } | |
223 | ||
224 | if (print) { | |
225 | printk(KERN_WARNING | |
b7d11258 | 226 | "audit: audit_lost=%d audit_rate_limit=%d audit_backlog_limit=%d\n", |
1da177e4 | 227 | atomic_read(&audit_lost), |
1da177e4 LT |
228 | audit_rate_limit, |
229 | audit_backlog_limit); | |
230 | audit_panic(message); | |
231 | } | |
1da177e4 LT |
232 | } |
233 | ||
ce29b682 | 234 | static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) |
1da177e4 | 235 | { |
ce29b682 SG |
236 | int old = audit_rate_limit; |
237 | ||
238 | if (sid) { | |
239 | char *ctx = NULL; | |
240 | u32 len; | |
241 | int rc; | |
242 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
243 | return rc; | |
244 | else | |
245 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
246 | "audit_rate_limit=%d old=%d by auid=%u subj=%s", | |
247 | limit, old, loginuid, ctx); | |
248 | kfree(ctx); | |
249 | } else | |
250 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 251 | "audit_rate_limit=%d old=%d by auid=%u", |
ce29b682 SG |
252 | limit, old, loginuid); |
253 | audit_rate_limit = limit; | |
5d136a01 | 254 | return 0; |
1da177e4 LT |
255 | } |
256 | ||
ce29b682 | 257 | static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) |
1da177e4 | 258 | { |
ce29b682 SG |
259 | int old = audit_backlog_limit; |
260 | ||
261 | if (sid) { | |
262 | char *ctx = NULL; | |
263 | u32 len; | |
264 | int rc; | |
265 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
266 | return rc; | |
267 | else | |
268 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
269 | "audit_backlog_limit=%d old=%d by auid=%u subj=%s", | |
270 | limit, old, loginuid, ctx); | |
271 | kfree(ctx); | |
272 | } else | |
273 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 274 | "audit_backlog_limit=%d old=%d by auid=%u", |
ce29b682 SG |
275 | limit, old, loginuid); |
276 | audit_backlog_limit = limit; | |
5d136a01 | 277 | return 0; |
1da177e4 LT |
278 | } |
279 | ||
ce29b682 | 280 | static int audit_set_enabled(int state, uid_t loginuid, u32 sid) |
1da177e4 | 281 | { |
ce29b682 SG |
282 | int old = audit_enabled; |
283 | ||
1da177e4 LT |
284 | if (state != 0 && state != 1) |
285 | return -EINVAL; | |
ce29b682 SG |
286 | |
287 | if (sid) { | |
288 | char *ctx = NULL; | |
289 | u32 len; | |
290 | int rc; | |
291 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
292 | return rc; | |
293 | else | |
294 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
295 | "audit_enabled=%d old=%d by auid=%u subj=%s", | |
296 | state, old, loginuid, ctx); | |
297 | kfree(ctx); | |
298 | } else | |
299 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 300 | "audit_enabled=%d old=%d by auid=%u", |
ce29b682 SG |
301 | state, old, loginuid); |
302 | audit_enabled = state; | |
5d136a01 | 303 | return 0; |
1da177e4 LT |
304 | } |
305 | ||
ce29b682 | 306 | static int audit_set_failure(int state, uid_t loginuid, u32 sid) |
1da177e4 | 307 | { |
ce29b682 SG |
308 | int old = audit_failure; |
309 | ||
1da177e4 LT |
310 | if (state != AUDIT_FAIL_SILENT |
311 | && state != AUDIT_FAIL_PRINTK | |
312 | && state != AUDIT_FAIL_PANIC) | |
313 | return -EINVAL; | |
ce29b682 SG |
314 | |
315 | if (sid) { | |
316 | char *ctx = NULL; | |
317 | u32 len; | |
318 | int rc; | |
319 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
320 | return rc; | |
321 | else | |
322 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
323 | "audit_failure=%d old=%d by auid=%u subj=%s", | |
324 | state, old, loginuid, ctx); | |
325 | kfree(ctx); | |
326 | } else | |
327 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 328 | "audit_failure=%d old=%d by auid=%u", |
ce29b682 SG |
329 | state, old, loginuid); |
330 | audit_failure = state; | |
5d136a01 | 331 | return 0; |
1da177e4 LT |
332 | } |
333 | ||
97a41e26 | 334 | static int kauditd_thread(void *dummy) |
b7d11258 DW |
335 | { |
336 | struct sk_buff *skb; | |
337 | ||
338 | while (1) { | |
339 | skb = skb_dequeue(&audit_skb_queue); | |
9ad9ad38 | 340 | wake_up(&audit_backlog_wait); |
b7d11258 DW |
341 | if (skb) { |
342 | if (audit_pid) { | |
343 | int err = netlink_unicast(audit_sock, skb, audit_pid, 0); | |
344 | if (err < 0) { | |
345 | BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */ | |
346 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); | |
347 | audit_pid = 0; | |
348 | } | |
349 | } else { | |
e1b09eba | 350 | printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0)); |
b7d11258 DW |
351 | kfree_skb(skb); |
352 | } | |
353 | } else { | |
354 | DECLARE_WAITQUEUE(wait, current); | |
355 | set_current_state(TASK_INTERRUPTIBLE); | |
356 | add_wait_queue(&kauditd_wait, &wait); | |
357 | ||
7a4ae749 PO |
358 | if (!skb_queue_len(&audit_skb_queue)) { |
359 | try_to_freeze(); | |
b7d11258 | 360 | schedule(); |
7a4ae749 | 361 | } |
b7d11258 DW |
362 | |
363 | __set_current_state(TASK_RUNNING); | |
364 | remove_wait_queue(&kauditd_wait, &wait); | |
365 | } | |
366 | } | |
367 | } | |
368 | ||
9044e6bc AV |
369 | int audit_send_list(void *_dest) |
370 | { | |
371 | struct audit_netlink_list *dest = _dest; | |
372 | int pid = dest->pid; | |
373 | struct sk_buff *skb; | |
374 | ||
375 | /* wait for parent to finish and send an ACK */ | |
376 | mutex_lock(&audit_netlink_mutex); | |
377 | mutex_unlock(&audit_netlink_mutex); | |
378 | ||
379 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
380 | netlink_unicast(audit_sock, skb, pid, 0); | |
381 | ||
382 | kfree(dest); | |
383 | ||
384 | return 0; | |
385 | } | |
386 | ||
387 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
388 | int multi, void *payload, int size) | |
389 | { | |
390 | struct sk_buff *skb; | |
391 | struct nlmsghdr *nlh; | |
392 | int len = NLMSG_SPACE(size); | |
393 | void *data; | |
394 | int flags = multi ? NLM_F_MULTI : 0; | |
395 | int t = done ? NLMSG_DONE : type; | |
396 | ||
397 | skb = alloc_skb(len, GFP_KERNEL); | |
398 | if (!skb) | |
399 | return NULL; | |
400 | ||
401 | nlh = NLMSG_PUT(skb, pid, seq, t, size); | |
402 | nlh->nlmsg_flags = flags; | |
403 | data = NLMSG_DATA(nlh); | |
404 | memcpy(data, payload, size); | |
405 | return skb; | |
406 | ||
407 | nlmsg_failure: /* Used by NLMSG_PUT */ | |
408 | if (skb) | |
409 | kfree_skb(skb); | |
410 | return NULL; | |
411 | } | |
412 | ||
b0dd25a8 RD |
413 | /** |
414 | * audit_send_reply - send an audit reply message via netlink | |
415 | * @pid: process id to send reply to | |
416 | * @seq: sequence number | |
417 | * @type: audit message type | |
418 | * @done: done (last) flag | |
419 | * @multi: multi-part message flag | |
420 | * @payload: payload data | |
421 | * @size: payload size | |
422 | * | |
423 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
424 | * No failure notifications. | |
425 | */ | |
1da177e4 LT |
426 | void audit_send_reply(int pid, int seq, int type, int done, int multi, |
427 | void *payload, int size) | |
428 | { | |
429 | struct sk_buff *skb; | |
9044e6bc | 430 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 431 | if (!skb) |
b7d11258 | 432 | return; |
b7d11258 DW |
433 | /* Ignore failure. It'll only happen if the sender goes away, |
434 | because our timeout is set to infinite. */ | |
435 | netlink_unicast(audit_sock, skb, pid, 0); | |
1da177e4 | 436 | return; |
1da177e4 LT |
437 | } |
438 | ||
439 | /* | |
440 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
441 | * control messages. | |
442 | */ | |
443 | static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type) | |
444 | { | |
445 | int err = 0; | |
446 | ||
447 | switch (msg_type) { | |
448 | case AUDIT_GET: | |
449 | case AUDIT_LIST: | |
93315ed6 | 450 | case AUDIT_LIST_RULES: |
1da177e4 LT |
451 | case AUDIT_SET: |
452 | case AUDIT_ADD: | |
93315ed6 | 453 | case AUDIT_ADD_RULE: |
1da177e4 | 454 | case AUDIT_DEL: |
93315ed6 | 455 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 456 | case AUDIT_SIGNAL_INFO: |
1da177e4 LT |
457 | if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL)) |
458 | err = -EPERM; | |
459 | break; | |
05474106 | 460 | case AUDIT_USER: |
209aba03 | 461 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
90d526c0 | 462 | case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2: |
1da177e4 LT |
463 | if (!cap_raised(eff_cap, CAP_AUDIT_WRITE)) |
464 | err = -EPERM; | |
465 | break; | |
466 | default: /* bad msg */ | |
467 | err = -EINVAL; | |
468 | } | |
469 | ||
470 | return err; | |
471 | } | |
472 | ||
473 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) | |
474 | { | |
e7c34970 | 475 | u32 uid, pid, seq, sid; |
1da177e4 LT |
476 | void *data; |
477 | struct audit_status *status_get, status_set; | |
478 | int err; | |
c0404993 | 479 | struct audit_buffer *ab; |
1da177e4 | 480 | u16 msg_type = nlh->nlmsg_type; |
c94c257c | 481 | uid_t loginuid; /* loginuid of sender */ |
e1396065 AV |
482 | struct audit_sig_info *sig_data; |
483 | char *ctx; | |
484 | u32 len; | |
1da177e4 LT |
485 | |
486 | err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type); | |
487 | if (err) | |
488 | return err; | |
489 | ||
b0dd25a8 RD |
490 | /* As soon as there's any sign of userspace auditd, |
491 | * start kauditd to talk to it */ | |
b7d11258 DW |
492 | if (!kauditd_task) |
493 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); | |
494 | if (IS_ERR(kauditd_task)) { | |
495 | err = PTR_ERR(kauditd_task); | |
496 | kauditd_task = NULL; | |
497 | return err; | |
498 | } | |
499 | ||
1da177e4 LT |
500 | pid = NETLINK_CREDS(skb)->pid; |
501 | uid = NETLINK_CREDS(skb)->uid; | |
c94c257c | 502 | loginuid = NETLINK_CB(skb).loginuid; |
e7c34970 | 503 | sid = NETLINK_CB(skb).sid; |
1da177e4 LT |
504 | seq = nlh->nlmsg_seq; |
505 | data = NLMSG_DATA(nlh); | |
506 | ||
507 | switch (msg_type) { | |
508 | case AUDIT_GET: | |
509 | status_set.enabled = audit_enabled; | |
510 | status_set.failure = audit_failure; | |
511 | status_set.pid = audit_pid; | |
512 | status_set.rate_limit = audit_rate_limit; | |
513 | status_set.backlog_limit = audit_backlog_limit; | |
514 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 515 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
1da177e4 LT |
516 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, |
517 | &status_set, sizeof(status_set)); | |
518 | break; | |
519 | case AUDIT_SET: | |
520 | if (nlh->nlmsg_len < sizeof(struct audit_status)) | |
521 | return -EINVAL; | |
522 | status_get = (struct audit_status *)data; | |
523 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
ce29b682 SG |
524 | err = audit_set_enabled(status_get->enabled, |
525 | loginuid, sid); | |
1da177e4 LT |
526 | if (err < 0) return err; |
527 | } | |
528 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
ce29b682 SG |
529 | err = audit_set_failure(status_get->failure, |
530 | loginuid, sid); | |
1da177e4 LT |
531 | if (err < 0) return err; |
532 | } | |
533 | if (status_get->mask & AUDIT_STATUS_PID) { | |
534 | int old = audit_pid; | |
ce29b682 | 535 | if (sid) { |
e1396065 | 536 | if ((err = selinux_ctxid_to_string( |
ce29b682 | 537 | sid, &ctx, &len))) |
e1396065 | 538 | return err; |
ce29b682 SG |
539 | else |
540 | audit_log(NULL, GFP_KERNEL, | |
541 | AUDIT_CONFIG_CHANGE, | |
542 | "audit_pid=%d old=%d by auid=%u subj=%s", | |
543 | status_get->pid, old, | |
544 | loginuid, ctx); | |
545 | kfree(ctx); | |
546 | } else | |
547 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
548 | "audit_pid=%d old=%d by auid=%u", | |
549 | status_get->pid, old, loginuid); | |
1da177e4 | 550 | audit_pid = status_get->pid; |
1da177e4 LT |
551 | } |
552 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) | |
5d136a01 | 553 | err = audit_set_rate_limit(status_get->rate_limit, |
ce29b682 | 554 | loginuid, sid); |
1da177e4 | 555 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
5d136a01 | 556 | err = audit_set_backlog_limit(status_get->backlog_limit, |
ce29b682 | 557 | loginuid, sid); |
1da177e4 | 558 | break; |
05474106 | 559 | case AUDIT_USER: |
209aba03 | 560 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
90d526c0 | 561 | case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2: |
4a4cd633 DW |
562 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
563 | return 0; | |
564 | ||
5bb289b5 | 565 | err = audit_filter_user(&NETLINK_CB(skb), msg_type); |
4a4cd633 DW |
566 | if (err == 1) { |
567 | err = 0; | |
9ad9ad38 | 568 | ab = audit_log_start(NULL, GFP_KERNEL, msg_type); |
4a4cd633 DW |
569 | if (ab) { |
570 | audit_log_format(ab, | |
e7c34970 SG |
571 | "user pid=%d uid=%u auid=%u", |
572 | pid, uid, loginuid); | |
573 | if (sid) { | |
e7c34970 SG |
574 | if (selinux_ctxid_to_string( |
575 | sid, &ctx, &len)) { | |
576 | audit_log_format(ab, | |
ce29b682 | 577 | " ssid=%u", sid); |
e7c34970 SG |
578 | /* Maybe call audit_panic? */ |
579 | } else | |
580 | audit_log_format(ab, | |
581 | " subj=%s", ctx); | |
582 | kfree(ctx); | |
583 | } | |
584 | audit_log_format(ab, " msg='%.1024s'", | |
585 | (char *)data); | |
4a4cd633 DW |
586 | audit_set_pid(ab, pid); |
587 | audit_log_end(ab); | |
588 | } | |
0f45aa18 | 589 | } |
1da177e4 LT |
590 | break; |
591 | case AUDIT_ADD: | |
592 | case AUDIT_DEL: | |
93315ed6 | 593 | if (nlmsg_len(nlh) < sizeof(struct audit_rule)) |
1da177e4 LT |
594 | return -EINVAL; |
595 | /* fallthrough */ | |
596 | case AUDIT_LIST: | |
1da177e4 | 597 | err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, |
93315ed6 | 598 | uid, seq, data, nlmsg_len(nlh), |
ce29b682 | 599 | loginuid, sid); |
93315ed6 AG |
600 | break; |
601 | case AUDIT_ADD_RULE: | |
602 | case AUDIT_DEL_RULE: | |
603 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
604 | return -EINVAL; | |
605 | /* fallthrough */ | |
606 | case AUDIT_LIST_RULES: | |
607 | err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, | |
608 | uid, seq, data, nlmsg_len(nlh), | |
ce29b682 | 609 | loginuid, sid); |
1da177e4 | 610 | break; |
c2f0c7c3 | 611 | case AUDIT_SIGNAL_INFO: |
e1396065 AV |
612 | err = selinux_ctxid_to_string(audit_sig_sid, &ctx, &len); |
613 | if (err) | |
614 | return err; | |
615 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); | |
616 | if (!sig_data) { | |
617 | kfree(ctx); | |
618 | return -ENOMEM; | |
619 | } | |
620 | sig_data->uid = audit_sig_uid; | |
621 | sig_data->pid = audit_sig_pid; | |
622 | memcpy(sig_data->ctx, ctx, len); | |
623 | kfree(ctx); | |
c2f0c7c3 | 624 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
625 | 0, 0, sig_data, sizeof(*sig_data) + len); |
626 | kfree(sig_data); | |
c2f0c7c3 | 627 | break; |
1da177e4 LT |
628 | default: |
629 | err = -EINVAL; | |
630 | break; | |
631 | } | |
632 | ||
633 | return err < 0 ? err : 0; | |
634 | } | |
635 | ||
b0dd25a8 RD |
636 | /* |
637 | * Get message from skb (based on rtnetlink_rcv_skb). Each message is | |
1da177e4 | 638 | * processed by audit_receive_msg. Malformed skbs with wrong length are |
b0dd25a8 RD |
639 | * discarded silently. |
640 | */ | |
2a0a6ebe | 641 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 LT |
642 | { |
643 | int err; | |
644 | struct nlmsghdr *nlh; | |
645 | u32 rlen; | |
646 | ||
647 | while (skb->len >= NLMSG_SPACE(0)) { | |
648 | nlh = (struct nlmsghdr *)skb->data; | |
649 | if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) | |
2a0a6ebe | 650 | return; |
1da177e4 LT |
651 | rlen = NLMSG_ALIGN(nlh->nlmsg_len); |
652 | if (rlen > skb->len) | |
653 | rlen = skb->len; | |
654 | if ((err = audit_receive_msg(skb, nlh))) { | |
655 | netlink_ack(skb, nlh, err); | |
656 | } else if (nlh->nlmsg_flags & NLM_F_ACK) | |
657 | netlink_ack(skb, nlh, 0); | |
658 | skb_pull(skb, rlen); | |
659 | } | |
1da177e4 LT |
660 | } |
661 | ||
662 | /* Receive messages from netlink socket. */ | |
663 | static void audit_receive(struct sock *sk, int length) | |
664 | { | |
665 | struct sk_buff *skb; | |
2a0a6ebe | 666 | unsigned int qlen; |
1da177e4 | 667 | |
5a0bbce5 | 668 | mutex_lock(&audit_netlink_mutex); |
1da177e4 | 669 | |
2a0a6ebe HX |
670 | for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) { |
671 | skb = skb_dequeue(&sk->sk_receive_queue); | |
672 | audit_receive_skb(skb); | |
673 | kfree_skb(skb); | |
1da177e4 | 674 | } |
5a0bbce5 | 675 | mutex_unlock(&audit_netlink_mutex); |
1da177e4 LT |
676 | } |
677 | ||
1da177e4 LT |
678 | |
679 | /* Initialize audit support at boot time. */ | |
680 | static int __init audit_init(void) | |
681 | { | |
682 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", | |
683 | audit_default ? "enabled" : "disabled"); | |
06628607 | 684 | audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive, |
4fdb3bb7 | 685 | THIS_MODULE); |
1da177e4 LT |
686 | if (!audit_sock) |
687 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
688 | else |
689 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 690 | |
b7d11258 | 691 | skb_queue_head_init(&audit_skb_queue); |
1da177e4 LT |
692 | audit_initialized = 1; |
693 | audit_enabled = audit_default; | |
3dc7e315 DG |
694 | |
695 | /* Register the callback with selinux. This callback will be invoked | |
696 | * when a new policy is loaded. */ | |
697 | selinux_audit_set_callback(&selinux_audit_rule_update); | |
698 | ||
9ad9ad38 | 699 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
1da177e4 LT |
700 | return 0; |
701 | } | |
1da177e4 LT |
702 | __initcall(audit_init); |
703 | ||
704 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
705 | static int __init audit_enable(char *str) | |
706 | { | |
707 | audit_default = !!simple_strtol(str, NULL, 0); | |
708 | printk(KERN_INFO "audit: %s%s\n", | |
709 | audit_default ? "enabled" : "disabled", | |
710 | audit_initialized ? "" : " (after initialization)"); | |
711 | if (audit_initialized) | |
712 | audit_enabled = audit_default; | |
9b41046c | 713 | return 1; |
1da177e4 LT |
714 | } |
715 | ||
716 | __setup("audit=", audit_enable); | |
717 | ||
16e1904e CW |
718 | static void audit_buffer_free(struct audit_buffer *ab) |
719 | { | |
720 | unsigned long flags; | |
721 | ||
8fc6115c CW |
722 | if (!ab) |
723 | return; | |
724 | ||
5ac52f33 CW |
725 | if (ab->skb) |
726 | kfree_skb(ab->skb); | |
b7d11258 | 727 | |
16e1904e | 728 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 729 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 730 | kfree(ab); |
5d136a01 SH |
731 | else { |
732 | audit_freelist_count++; | |
16e1904e | 733 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 734 | } |
16e1904e CW |
735 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
736 | } | |
737 | ||
c0404993 | 738 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 739 | gfp_t gfp_mask, int type) |
16e1904e CW |
740 | { |
741 | unsigned long flags; | |
742 | struct audit_buffer *ab = NULL; | |
c0404993 | 743 | struct nlmsghdr *nlh; |
16e1904e CW |
744 | |
745 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
746 | if (!list_empty(&audit_freelist)) { | |
747 | ab = list_entry(audit_freelist.next, | |
748 | struct audit_buffer, list); | |
749 | list_del(&ab->list); | |
750 | --audit_freelist_count; | |
751 | } | |
752 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
753 | ||
754 | if (!ab) { | |
4332bdd3 | 755 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 756 | if (!ab) |
8fc6115c | 757 | goto err; |
16e1904e | 758 | } |
8fc6115c | 759 | |
4332bdd3 | 760 | ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask); |
5ac52f33 | 761 | if (!ab->skb) |
8fc6115c CW |
762 | goto err; |
763 | ||
b7d11258 | 764 | ab->ctx = ctx; |
9ad9ad38 | 765 | ab->gfp_mask = gfp_mask; |
c0404993 SG |
766 | nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0)); |
767 | nlh->nlmsg_type = type; | |
768 | nlh->nlmsg_flags = 0; | |
769 | nlh->nlmsg_pid = 0; | |
770 | nlh->nlmsg_seq = 0; | |
16e1904e | 771 | return ab; |
8fc6115c CW |
772 | err: |
773 | audit_buffer_free(ab); | |
774 | return NULL; | |
16e1904e | 775 | } |
1da177e4 | 776 | |
b0dd25a8 RD |
777 | /** |
778 | * audit_serial - compute a serial number for the audit record | |
779 | * | |
780 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
781 | * written to user-space as soon as they are generated, so a complete |
782 | * audit record may be written in several pieces. The timestamp of the | |
783 | * record and this serial number are used by the user-space tools to | |
784 | * determine which pieces belong to the same audit record. The | |
785 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
786 | * syscall entry to syscall exit. | |
787 | * | |
bfb4496e DW |
788 | * NOTE: Another possibility is to store the formatted records off the |
789 | * audit context (for those records that have a context), and emit them | |
790 | * all at syscall exit. However, this could delay the reporting of | |
791 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
792 | * halts). |
793 | */ | |
bfb4496e DW |
794 | unsigned int audit_serial(void) |
795 | { | |
d5b454f2 DW |
796 | static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED; |
797 | static unsigned int serial = 0; | |
798 | ||
799 | unsigned long flags; | |
800 | unsigned int ret; | |
bfb4496e | 801 | |
d5b454f2 | 802 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 803 | do { |
ce625a80 DW |
804 | ret = ++serial; |
805 | } while (unlikely(!ret)); | |
d5b454f2 | 806 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 807 | |
d5b454f2 | 808 | return ret; |
bfb4496e DW |
809 | } |
810 | ||
811 | static inline void audit_get_stamp(struct audit_context *ctx, | |
812 | struct timespec *t, unsigned int *serial) | |
813 | { | |
814 | if (ctx) | |
815 | auditsc_get_stamp(ctx, t, serial); | |
816 | else { | |
817 | *t = CURRENT_TIME; | |
818 | *serial = audit_serial(); | |
819 | } | |
820 | } | |
821 | ||
1da177e4 LT |
822 | /* Obtain an audit buffer. This routine does locking to obtain the |
823 | * audit buffer, but then no locking is required for calls to | |
824 | * audit_log_*format. If the tsk is a task that is currently in a | |
825 | * syscall, then the syscall is marked as auditable and an audit record | |
826 | * will be written at syscall exit. If there is no associated task, tsk | |
827 | * should be NULL. */ | |
9ad9ad38 | 828 | |
b0dd25a8 RD |
829 | /** |
830 | * audit_log_start - obtain an audit buffer | |
831 | * @ctx: audit_context (may be NULL) | |
832 | * @gfp_mask: type of allocation | |
833 | * @type: audit message type | |
834 | * | |
835 | * Returns audit_buffer pointer on success or NULL on error. | |
836 | * | |
837 | * Obtain an audit buffer. This routine does locking to obtain the | |
838 | * audit buffer, but then no locking is required for calls to | |
839 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
840 | * syscall, then the syscall is marked as auditable and an audit record | |
841 | * will be written at syscall exit. If there is no associated task, then | |
842 | * task context (ctx) should be NULL. | |
843 | */ | |
9796fdd8 | 844 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 845 | int type) |
1da177e4 LT |
846 | { |
847 | struct audit_buffer *ab = NULL; | |
1da177e4 | 848 | struct timespec t; |
d812ddbb | 849 | unsigned int serial; |
9ad9ad38 | 850 | int reserve; |
ac4cec44 | 851 | unsigned long timeout_start = jiffies; |
1da177e4 LT |
852 | |
853 | if (!audit_initialized) | |
854 | return NULL; | |
855 | ||
c8edc80c DK |
856 | if (unlikely(audit_filter_type(type))) |
857 | return NULL; | |
858 | ||
9ad9ad38 DW |
859 | if (gfp_mask & __GFP_WAIT) |
860 | reserve = 0; | |
861 | else | |
862 | reserve = 5; /* Allow atomic callers to go up to five | |
863 | entries over the normal backlog limit */ | |
864 | ||
865 | while (audit_backlog_limit | |
866 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
ac4cec44 DW |
867 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time |
868 | && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { | |
869 | ||
9ad9ad38 DW |
870 | /* Wait for auditd to drain the queue a little */ |
871 | DECLARE_WAITQUEUE(wait, current); | |
872 | set_current_state(TASK_INTERRUPTIBLE); | |
873 | add_wait_queue(&audit_backlog_wait, &wait); | |
874 | ||
875 | if (audit_backlog_limit && | |
876 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ac4cec44 | 877 | schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); |
9ad9ad38 DW |
878 | |
879 | __set_current_state(TASK_RUNNING); | |
880 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ac4cec44 | 881 | continue; |
9ad9ad38 | 882 | } |
fb19b4c6 DW |
883 | if (audit_rate_check()) |
884 | printk(KERN_WARNING | |
885 | "audit: audit_backlog=%d > " | |
886 | "audit_backlog_limit=%d\n", | |
887 | skb_queue_len(&audit_skb_queue), | |
888 | audit_backlog_limit); | |
889 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
890 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
891 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
892 | return NULL; |
893 | } | |
894 | ||
9ad9ad38 | 895 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
896 | if (!ab) { |
897 | audit_log_lost("out of memory in audit_log_start"); | |
898 | return NULL; | |
899 | } | |
900 | ||
bfb4496e | 901 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 902 | |
1da177e4 LT |
903 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
904 | t.tv_sec, t.tv_nsec/1000000, serial); | |
905 | return ab; | |
906 | } | |
907 | ||
8fc6115c | 908 | /** |
5ac52f33 | 909 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 910 | * @ab: audit_buffer |
b0dd25a8 | 911 | * @extra: space to add at tail of the skb |
8fc6115c CW |
912 | * |
913 | * Returns 0 (no space) on failed expansion, or available space if | |
914 | * successful. | |
915 | */ | |
e3b926b4 | 916 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 917 | { |
5ac52f33 | 918 | struct sk_buff *skb = ab->skb; |
e3b926b4 | 919 | int ret = pskb_expand_head(skb, skb_headroom(skb), extra, |
9ad9ad38 | 920 | ab->gfp_mask); |
5ac52f33 CW |
921 | if (ret < 0) { |
922 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 923 | return 0; |
5ac52f33 CW |
924 | } |
925 | return skb_tailroom(skb); | |
8fc6115c | 926 | } |
1da177e4 | 927 | |
b0dd25a8 RD |
928 | /* |
929 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
930 | * room in the audit buffer, more room will be allocated and vsnprint |
931 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
932 | * can't format message larger than 1024 bytes, so we don't either. |
933 | */ | |
1da177e4 LT |
934 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
935 | va_list args) | |
936 | { | |
937 | int len, avail; | |
5ac52f33 | 938 | struct sk_buff *skb; |
eecb0a73 | 939 | va_list args2; |
1da177e4 LT |
940 | |
941 | if (!ab) | |
942 | return; | |
943 | ||
5ac52f33 CW |
944 | BUG_ON(!ab->skb); |
945 | skb = ab->skb; | |
946 | avail = skb_tailroom(skb); | |
947 | if (avail == 0) { | |
e3b926b4 | 948 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
949 | if (!avail) |
950 | goto out; | |
1da177e4 | 951 | } |
eecb0a73 | 952 | va_copy(args2, args); |
5ac52f33 | 953 | len = vsnprintf(skb->tail, avail, fmt, args); |
1da177e4 LT |
954 | if (len >= avail) { |
955 | /* The printk buffer is 1024 bytes long, so if we get | |
956 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
957 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
958 | avail = audit_expand(ab, |
959 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c CW |
960 | if (!avail) |
961 | goto out; | |
eecb0a73 | 962 | len = vsnprintf(skb->tail, avail, fmt, args2); |
1da177e4 | 963 | } |
168b7173 SG |
964 | if (len > 0) |
965 | skb_put(skb, len); | |
8fc6115c CW |
966 | out: |
967 | return; | |
1da177e4 LT |
968 | } |
969 | ||
b0dd25a8 RD |
970 | /** |
971 | * audit_log_format - format a message into the audit buffer. | |
972 | * @ab: audit_buffer | |
973 | * @fmt: format string | |
974 | * @...: optional parameters matching @fmt string | |
975 | * | |
976 | * All the work is done in audit_log_vformat. | |
977 | */ | |
1da177e4 LT |
978 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
979 | { | |
980 | va_list args; | |
981 | ||
982 | if (!ab) | |
983 | return; | |
984 | va_start(args, fmt); | |
985 | audit_log_vformat(ab, fmt, args); | |
986 | va_end(args); | |
987 | } | |
988 | ||
b0dd25a8 RD |
989 | /** |
990 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
991 | * @ab: the audit_buffer | |
992 | * @buf: buffer to convert to hex | |
993 | * @len: length of @buf to be converted | |
994 | * | |
995 | * No return value; failure to expand is silently ignored. | |
996 | * | |
997 | * This function will take the passed buf and convert it into a string of | |
998 | * ascii hex digits. The new string is placed onto the skb. | |
999 | */ | |
1000 | void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, | |
168b7173 | 1001 | size_t len) |
83c7d091 | 1002 | { |
168b7173 SG |
1003 | int i, avail, new_len; |
1004 | unsigned char *ptr; | |
1005 | struct sk_buff *skb; | |
1006 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1007 | ||
1008 | BUG_ON(!ab->skb); | |
1009 | skb = ab->skb; | |
1010 | avail = skb_tailroom(skb); | |
1011 | new_len = len<<1; | |
1012 | if (new_len >= avail) { | |
1013 | /* Round the buffer request up to the next multiple */ | |
1014 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1015 | avail = audit_expand(ab, new_len); | |
1016 | if (!avail) | |
1017 | return; | |
1018 | } | |
83c7d091 | 1019 | |
168b7173 SG |
1020 | ptr = skb->tail; |
1021 | for (i=0; i<len; i++) { | |
1022 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1023 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1024 | } | |
1025 | *ptr = 0; | |
1026 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1027 | } |
1028 | ||
b0dd25a8 RD |
1029 | /** |
1030 | * audit_log_unstrustedstring - log a string that may contain random characters | |
1031 | * @ab: audit_buffer | |
1032 | * @string: string to be logged | |
1033 | * | |
1034 | * This code will escape a string that is passed to it if the string | |
1035 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1036 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 RD |
1037 | * Strings that are escaped are printed in hex (2 digits per char). |
1038 | */ | |
473ae30b | 1039 | const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
83c7d091 | 1040 | { |
81b7854d | 1041 | const unsigned char *p = string; |
473ae30b | 1042 | size_t len = strlen(string); |
83c7d091 | 1043 | |
1044 | while (*p) { | |
168b7173 | 1045 | if (*p == '"' || *p < 0x21 || *p > 0x7f) { |
473ae30b AV |
1046 | audit_log_hex(ab, string, len); |
1047 | return string + len + 1; | |
83c7d091 | 1048 | } |
1049 | p++; | |
1050 | } | |
1051 | audit_log_format(ab, "\"%s\"", string); | |
473ae30b | 1052 | return p + 1; |
83c7d091 | 1053 | } |
1054 | ||
168b7173 | 1055 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 LT |
1056 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
1057 | struct dentry *dentry, struct vfsmount *vfsmnt) | |
1058 | { | |
168b7173 | 1059 | char *p, *path; |
1da177e4 | 1060 | |
8fc6115c CW |
1061 | if (prefix) |
1062 | audit_log_format(ab, " %s", prefix); | |
1da177e4 | 1063 | |
168b7173 | 1064 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
9ad9ad38 | 1065 | path = kmalloc(PATH_MAX+11, ab->gfp_mask); |
168b7173 SG |
1066 | if (!path) { |
1067 | audit_log_format(ab, "<no memory>"); | |
1068 | return; | |
1da177e4 | 1069 | } |
168b7173 SG |
1070 | p = d_path(dentry, vfsmnt, path, PATH_MAX+11); |
1071 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ | |
1072 | /* FIXME: can we save some information here? */ | |
1073 | audit_log_format(ab, "<too long>"); | |
1074 | } else | |
1075 | audit_log_untrustedstring(ab, p); | |
1076 | kfree(path); | |
1da177e4 LT |
1077 | } |
1078 | ||
b0dd25a8 RD |
1079 | /** |
1080 | * audit_log_end - end one audit record | |
1081 | * @ab: the audit_buffer | |
1082 | * | |
1083 | * The netlink_* functions cannot be called inside an irq context, so | |
1084 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1085 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1086 | * any context. |
1087 | */ | |
b7d11258 | 1088 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1089 | { |
1da177e4 LT |
1090 | if (!ab) |
1091 | return; | |
1092 | if (!audit_rate_check()) { | |
1093 | audit_log_lost("rate limit exceeded"); | |
1094 | } else { | |
b7d11258 DW |
1095 | if (audit_pid) { |
1096 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; | |
1097 | nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); | |
1098 | skb_queue_tail(&audit_skb_queue, ab->skb); | |
1099 | ab->skb = NULL; | |
1100 | wake_up_interruptible(&kauditd_wait); | |
1101 | } else { | |
e1b09eba | 1102 | printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0)); |
b7d11258 | 1103 | } |
1da177e4 | 1104 | } |
16e1904e | 1105 | audit_buffer_free(ab); |
1da177e4 LT |
1106 | } |
1107 | ||
b0dd25a8 RD |
1108 | /** |
1109 | * audit_log - Log an audit record | |
1110 | * @ctx: audit context | |
1111 | * @gfp_mask: type of allocation | |
1112 | * @type: audit message type | |
1113 | * @fmt: format string to use | |
1114 | * @...: variable parameters matching the format string | |
1115 | * | |
1116 | * This is a convenience function that calls audit_log_start, | |
1117 | * audit_log_vformat, and audit_log_end. It may be called | |
1118 | * in any context. | |
1119 | */ | |
9796fdd8 | 1120 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1121 | const char *fmt, ...) |
1da177e4 LT |
1122 | { |
1123 | struct audit_buffer *ab; | |
1124 | va_list args; | |
1125 | ||
9ad9ad38 | 1126 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1127 | if (ab) { |
1128 | va_start(args, fmt); | |
1129 | audit_log_vformat(ab, fmt, args); | |
1130 | va_end(args); | |
1131 | audit_log_end(ab); | |
1132 | } | |
1133 | } | |
bf45da97 | 1134 | |
1135 | EXPORT_SYMBOL(audit_log_start); | |
1136 | EXPORT_SYMBOL(audit_log_end); | |
1137 | EXPORT_SYMBOL(audit_log_format); | |
1138 | EXPORT_SYMBOL(audit_log); |