Commit | Line | Data |
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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 | 58 | #include <linux/selinux.h> |
f368c07d | 59 | #include <linux/inotify.h> |
3dc7e315 DG |
60 | |
61 | #include "audit.h" | |
1da177e4 LT |
62 | |
63 | /* No auditing will take place until audit_initialized != 0. | |
64 | * (Initialization happens after skb_init is called.) */ | |
65 | static int audit_initialized; | |
66 | ||
67 | /* No syscall auditing will take place unless audit_enabled != 0. */ | |
68 | int audit_enabled; | |
69 | ||
70 | /* Default state when kernel boots without any parameters. */ | |
71 | static int audit_default; | |
72 | ||
73 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
74 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
75 | ||
76 | /* If audit records are to be written to the netlink socket, audit_pid | |
77 | * contains the (non-zero) pid. */ | |
c2f0c7c3 | 78 | int audit_pid; |
1da177e4 | 79 | |
b0dd25a8 | 80 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
81 | * to that number per second. This prevents DoS attacks, but results in |
82 | * audit records being dropped. */ | |
83 | static int audit_rate_limit; | |
84 | ||
85 | /* Number of outstanding audit_buffers allowed. */ | |
86 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
87 | static int audit_backlog_wait_time = 60 * HZ; |
88 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 89 | |
c2f0c7c3 SG |
90 | /* The identity of the user shutting down the audit system. */ |
91 | uid_t audit_sig_uid = -1; | |
92 | pid_t audit_sig_pid = -1; | |
e1396065 | 93 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 94 | |
1da177e4 LT |
95 | /* Records can be lost in several ways: |
96 | 0) [suppressed in audit_alloc] | |
97 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
98 | 2) out of memory in audit_log_move [alloc_skb] | |
99 | 3) suppressed due to audit_rate_limit | |
100 | 4) suppressed due to audit_backlog_limit | |
101 | */ | |
102 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
103 | ||
104 | /* The netlink socket. */ | |
105 | static struct sock *audit_sock; | |
106 | ||
f368c07d AG |
107 | /* Inotify handle. */ |
108 | struct inotify_handle *audit_ih; | |
109 | ||
110 | /* Hash for inode-based rules */ | |
111 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
112 | ||
b7d11258 | 113 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
114 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
115 | * being placed on the freelist). */ | |
1da177e4 | 116 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 117 | static int audit_freelist_count; |
1da177e4 LT |
118 | static LIST_HEAD(audit_freelist); |
119 | ||
b7d11258 DW |
120 | static struct sk_buff_head audit_skb_queue; |
121 | static struct task_struct *kauditd_task; | |
122 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 123 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 124 | |
f368c07d AG |
125 | /* Serialize requests from userspace. */ |
126 | static DEFINE_MUTEX(audit_cmd_mutex); | |
1da177e4 LT |
127 | |
128 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
129 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
130 | * should be at least that large. */ | |
131 | #define AUDIT_BUFSIZ 1024 | |
132 | ||
133 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
134 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
135 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
136 | ||
137 | /* The audit_buffer is used when formatting an audit record. The caller | |
138 | * locks briefly to get the record off the freelist or to allocate the | |
139 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
140 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
141 | * use simultaneously. */ | |
142 | struct audit_buffer { | |
143 | struct list_head list; | |
8fc6115c | 144 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 145 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 146 | gfp_t gfp_mask; |
1da177e4 LT |
147 | }; |
148 | ||
c0404993 SG |
149 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
150 | { | |
151 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; | |
152 | nlh->nlmsg_pid = pid; | |
153 | } | |
154 | ||
8c8570fb | 155 | void audit_panic(const char *message) |
1da177e4 LT |
156 | { |
157 | switch (audit_failure) | |
158 | { | |
159 | case AUDIT_FAIL_SILENT: | |
160 | break; | |
161 | case AUDIT_FAIL_PRINTK: | |
162 | printk(KERN_ERR "audit: %s\n", message); | |
163 | break; | |
164 | case AUDIT_FAIL_PANIC: | |
165 | panic("audit: %s\n", message); | |
166 | break; | |
167 | } | |
168 | } | |
169 | ||
170 | static inline int audit_rate_check(void) | |
171 | { | |
172 | static unsigned long last_check = 0; | |
173 | static int messages = 0; | |
174 | static DEFINE_SPINLOCK(lock); | |
175 | unsigned long flags; | |
176 | unsigned long now; | |
177 | unsigned long elapsed; | |
178 | int retval = 0; | |
179 | ||
180 | if (!audit_rate_limit) return 1; | |
181 | ||
182 | spin_lock_irqsave(&lock, flags); | |
183 | if (++messages < audit_rate_limit) { | |
184 | retval = 1; | |
185 | } else { | |
186 | now = jiffies; | |
187 | elapsed = now - last_check; | |
188 | if (elapsed > HZ) { | |
189 | last_check = now; | |
190 | messages = 0; | |
191 | retval = 1; | |
192 | } | |
193 | } | |
194 | spin_unlock_irqrestore(&lock, flags); | |
195 | ||
196 | return retval; | |
197 | } | |
198 | ||
b0dd25a8 RD |
199 | /** |
200 | * audit_log_lost - conditionally log lost audit message event | |
201 | * @message: the message stating reason for lost audit message | |
202 | * | |
203 | * Emit at least 1 message per second, even if audit_rate_check is | |
204 | * throttling. | |
205 | * Always increment the lost messages counter. | |
206 | */ | |
1da177e4 LT |
207 | void audit_log_lost(const char *message) |
208 | { | |
209 | static unsigned long last_msg = 0; | |
210 | static DEFINE_SPINLOCK(lock); | |
211 | unsigned long flags; | |
212 | unsigned long now; | |
213 | int print; | |
214 | ||
215 | atomic_inc(&audit_lost); | |
216 | ||
217 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
218 | ||
219 | if (!print) { | |
220 | spin_lock_irqsave(&lock, flags); | |
221 | now = jiffies; | |
222 | if (now - last_msg > HZ) { | |
223 | print = 1; | |
224 | last_msg = now; | |
225 | } | |
226 | spin_unlock_irqrestore(&lock, flags); | |
227 | } | |
228 | ||
229 | if (print) { | |
230 | printk(KERN_WARNING | |
b7d11258 | 231 | "audit: audit_lost=%d audit_rate_limit=%d audit_backlog_limit=%d\n", |
1da177e4 | 232 | atomic_read(&audit_lost), |
1da177e4 LT |
233 | audit_rate_limit, |
234 | audit_backlog_limit); | |
235 | audit_panic(message); | |
236 | } | |
1da177e4 LT |
237 | } |
238 | ||
ce29b682 | 239 | static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) |
1da177e4 | 240 | { |
ce29b682 SG |
241 | int old = audit_rate_limit; |
242 | ||
243 | if (sid) { | |
244 | char *ctx = NULL; | |
245 | u32 len; | |
246 | int rc; | |
247 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
248 | return rc; | |
249 | else | |
250 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
251 | "audit_rate_limit=%d old=%d by auid=%u subj=%s", | |
252 | limit, old, loginuid, ctx); | |
253 | kfree(ctx); | |
254 | } else | |
255 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 256 | "audit_rate_limit=%d old=%d by auid=%u", |
ce29b682 SG |
257 | limit, old, loginuid); |
258 | audit_rate_limit = limit; | |
5d136a01 | 259 | return 0; |
1da177e4 LT |
260 | } |
261 | ||
ce29b682 | 262 | static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) |
1da177e4 | 263 | { |
ce29b682 SG |
264 | int old = audit_backlog_limit; |
265 | ||
266 | if (sid) { | |
267 | char *ctx = NULL; | |
268 | u32 len; | |
269 | int rc; | |
270 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
271 | return rc; | |
272 | else | |
273 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
274 | "audit_backlog_limit=%d old=%d by auid=%u subj=%s", | |
275 | limit, old, loginuid, ctx); | |
276 | kfree(ctx); | |
277 | } else | |
278 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 279 | "audit_backlog_limit=%d old=%d by auid=%u", |
ce29b682 SG |
280 | limit, old, loginuid); |
281 | audit_backlog_limit = limit; | |
5d136a01 | 282 | return 0; |
1da177e4 LT |
283 | } |
284 | ||
ce29b682 | 285 | static int audit_set_enabled(int state, uid_t loginuid, u32 sid) |
1da177e4 | 286 | { |
ce29b682 SG |
287 | int old = audit_enabled; |
288 | ||
1da177e4 LT |
289 | if (state != 0 && state != 1) |
290 | return -EINVAL; | |
ce29b682 SG |
291 | |
292 | if (sid) { | |
293 | char *ctx = NULL; | |
294 | u32 len; | |
295 | int rc; | |
296 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
297 | return rc; | |
298 | else | |
299 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
300 | "audit_enabled=%d old=%d by auid=%u subj=%s", | |
301 | state, old, loginuid, ctx); | |
302 | kfree(ctx); | |
303 | } else | |
304 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 305 | "audit_enabled=%d old=%d by auid=%u", |
ce29b682 SG |
306 | state, old, loginuid); |
307 | audit_enabled = state; | |
5d136a01 | 308 | return 0; |
1da177e4 LT |
309 | } |
310 | ||
ce29b682 | 311 | static int audit_set_failure(int state, uid_t loginuid, u32 sid) |
1da177e4 | 312 | { |
ce29b682 SG |
313 | int old = audit_failure; |
314 | ||
1da177e4 LT |
315 | if (state != AUDIT_FAIL_SILENT |
316 | && state != AUDIT_FAIL_PRINTK | |
317 | && state != AUDIT_FAIL_PANIC) | |
318 | return -EINVAL; | |
ce29b682 SG |
319 | |
320 | if (sid) { | |
321 | char *ctx = NULL; | |
322 | u32 len; | |
323 | int rc; | |
324 | if ((rc = selinux_ctxid_to_string(sid, &ctx, &len))) | |
325 | return rc; | |
326 | else | |
327 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
328 | "audit_failure=%d old=%d by auid=%u subj=%s", | |
329 | state, old, loginuid, ctx); | |
330 | kfree(ctx); | |
331 | } else | |
332 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
bccf6ae0 | 333 | "audit_failure=%d old=%d by auid=%u", |
ce29b682 SG |
334 | state, old, loginuid); |
335 | audit_failure = state; | |
5d136a01 | 336 | return 0; |
1da177e4 LT |
337 | } |
338 | ||
97a41e26 | 339 | static int kauditd_thread(void *dummy) |
b7d11258 DW |
340 | { |
341 | struct sk_buff *skb; | |
342 | ||
343 | while (1) { | |
344 | skb = skb_dequeue(&audit_skb_queue); | |
9ad9ad38 | 345 | wake_up(&audit_backlog_wait); |
b7d11258 DW |
346 | if (skb) { |
347 | if (audit_pid) { | |
348 | int err = netlink_unicast(audit_sock, skb, audit_pid, 0); | |
349 | if (err < 0) { | |
350 | BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */ | |
351 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); | |
352 | audit_pid = 0; | |
353 | } | |
354 | } else { | |
e1b09eba | 355 | printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0)); |
b7d11258 DW |
356 | kfree_skb(skb); |
357 | } | |
358 | } else { | |
359 | DECLARE_WAITQUEUE(wait, current); | |
360 | set_current_state(TASK_INTERRUPTIBLE); | |
361 | add_wait_queue(&kauditd_wait, &wait); | |
362 | ||
7a4ae749 PO |
363 | if (!skb_queue_len(&audit_skb_queue)) { |
364 | try_to_freeze(); | |
b7d11258 | 365 | schedule(); |
7a4ae749 | 366 | } |
b7d11258 DW |
367 | |
368 | __set_current_state(TASK_RUNNING); | |
369 | remove_wait_queue(&kauditd_wait, &wait); | |
370 | } | |
371 | } | |
372 | } | |
373 | ||
9044e6bc AV |
374 | int audit_send_list(void *_dest) |
375 | { | |
376 | struct audit_netlink_list *dest = _dest; | |
377 | int pid = dest->pid; | |
378 | struct sk_buff *skb; | |
379 | ||
380 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
381 | mutex_lock(&audit_cmd_mutex); |
382 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
383 | |
384 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
385 | netlink_unicast(audit_sock, skb, pid, 0); | |
386 | ||
387 | kfree(dest); | |
388 | ||
389 | return 0; | |
390 | } | |
391 | ||
392 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
393 | int multi, void *payload, int size) | |
394 | { | |
395 | struct sk_buff *skb; | |
396 | struct nlmsghdr *nlh; | |
397 | int len = NLMSG_SPACE(size); | |
398 | void *data; | |
399 | int flags = multi ? NLM_F_MULTI : 0; | |
400 | int t = done ? NLMSG_DONE : type; | |
401 | ||
402 | skb = alloc_skb(len, GFP_KERNEL); | |
403 | if (!skb) | |
404 | return NULL; | |
405 | ||
406 | nlh = NLMSG_PUT(skb, pid, seq, t, size); | |
407 | nlh->nlmsg_flags = flags; | |
408 | data = NLMSG_DATA(nlh); | |
409 | memcpy(data, payload, size); | |
410 | return skb; | |
411 | ||
412 | nlmsg_failure: /* Used by NLMSG_PUT */ | |
413 | if (skb) | |
414 | kfree_skb(skb); | |
415 | return NULL; | |
416 | } | |
417 | ||
b0dd25a8 RD |
418 | /** |
419 | * audit_send_reply - send an audit reply message via netlink | |
420 | * @pid: process id to send reply to | |
421 | * @seq: sequence number | |
422 | * @type: audit message type | |
423 | * @done: done (last) flag | |
424 | * @multi: multi-part message flag | |
425 | * @payload: payload data | |
426 | * @size: payload size | |
427 | * | |
428 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
429 | * No failure notifications. | |
430 | */ | |
1da177e4 LT |
431 | void audit_send_reply(int pid, int seq, int type, int done, int multi, |
432 | void *payload, int size) | |
433 | { | |
434 | struct sk_buff *skb; | |
9044e6bc | 435 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 436 | if (!skb) |
b7d11258 | 437 | return; |
b7d11258 DW |
438 | /* Ignore failure. It'll only happen if the sender goes away, |
439 | because our timeout is set to infinite. */ | |
440 | netlink_unicast(audit_sock, skb, pid, 0); | |
1da177e4 | 441 | return; |
1da177e4 LT |
442 | } |
443 | ||
444 | /* | |
445 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
446 | * control messages. | |
447 | */ | |
448 | static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type) | |
449 | { | |
450 | int err = 0; | |
451 | ||
452 | switch (msg_type) { | |
453 | case AUDIT_GET: | |
454 | case AUDIT_LIST: | |
93315ed6 | 455 | case AUDIT_LIST_RULES: |
1da177e4 LT |
456 | case AUDIT_SET: |
457 | case AUDIT_ADD: | |
93315ed6 | 458 | case AUDIT_ADD_RULE: |
1da177e4 | 459 | case AUDIT_DEL: |
93315ed6 | 460 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 461 | case AUDIT_SIGNAL_INFO: |
1da177e4 LT |
462 | if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL)) |
463 | err = -EPERM; | |
464 | break; | |
05474106 | 465 | case AUDIT_USER: |
209aba03 | 466 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
90d526c0 | 467 | case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2: |
1da177e4 LT |
468 | if (!cap_raised(eff_cap, CAP_AUDIT_WRITE)) |
469 | err = -EPERM; | |
470 | break; | |
471 | default: /* bad msg */ | |
472 | err = -EINVAL; | |
473 | } | |
474 | ||
475 | return err; | |
476 | } | |
477 | ||
478 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) | |
479 | { | |
e7c34970 | 480 | u32 uid, pid, seq, sid; |
1da177e4 LT |
481 | void *data; |
482 | struct audit_status *status_get, status_set; | |
483 | int err; | |
c0404993 | 484 | struct audit_buffer *ab; |
1da177e4 | 485 | u16 msg_type = nlh->nlmsg_type; |
c94c257c | 486 | uid_t loginuid; /* loginuid of sender */ |
e1396065 AV |
487 | struct audit_sig_info *sig_data; |
488 | char *ctx; | |
489 | u32 len; | |
1da177e4 LT |
490 | |
491 | err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type); | |
492 | if (err) | |
493 | return err; | |
494 | ||
b0dd25a8 RD |
495 | /* As soon as there's any sign of userspace auditd, |
496 | * start kauditd to talk to it */ | |
b7d11258 DW |
497 | if (!kauditd_task) |
498 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); | |
499 | if (IS_ERR(kauditd_task)) { | |
500 | err = PTR_ERR(kauditd_task); | |
501 | kauditd_task = NULL; | |
502 | return err; | |
503 | } | |
504 | ||
1da177e4 LT |
505 | pid = NETLINK_CREDS(skb)->pid; |
506 | uid = NETLINK_CREDS(skb)->uid; | |
c94c257c | 507 | loginuid = NETLINK_CB(skb).loginuid; |
e7c34970 | 508 | sid = NETLINK_CB(skb).sid; |
1da177e4 LT |
509 | seq = nlh->nlmsg_seq; |
510 | data = NLMSG_DATA(nlh); | |
511 | ||
512 | switch (msg_type) { | |
513 | case AUDIT_GET: | |
514 | status_set.enabled = audit_enabled; | |
515 | status_set.failure = audit_failure; | |
516 | status_set.pid = audit_pid; | |
517 | status_set.rate_limit = audit_rate_limit; | |
518 | status_set.backlog_limit = audit_backlog_limit; | |
519 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 520 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
1da177e4 LT |
521 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, |
522 | &status_set, sizeof(status_set)); | |
523 | break; | |
524 | case AUDIT_SET: | |
525 | if (nlh->nlmsg_len < sizeof(struct audit_status)) | |
526 | return -EINVAL; | |
527 | status_get = (struct audit_status *)data; | |
528 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
ce29b682 SG |
529 | err = audit_set_enabled(status_get->enabled, |
530 | loginuid, sid); | |
1da177e4 LT |
531 | if (err < 0) return err; |
532 | } | |
533 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
ce29b682 SG |
534 | err = audit_set_failure(status_get->failure, |
535 | loginuid, sid); | |
1da177e4 LT |
536 | if (err < 0) return err; |
537 | } | |
538 | if (status_get->mask & AUDIT_STATUS_PID) { | |
539 | int old = audit_pid; | |
ce29b682 | 540 | if (sid) { |
e1396065 | 541 | if ((err = selinux_ctxid_to_string( |
ce29b682 | 542 | sid, &ctx, &len))) |
e1396065 | 543 | return err; |
ce29b682 SG |
544 | else |
545 | audit_log(NULL, GFP_KERNEL, | |
546 | AUDIT_CONFIG_CHANGE, | |
547 | "audit_pid=%d old=%d by auid=%u subj=%s", | |
548 | status_get->pid, old, | |
549 | loginuid, ctx); | |
550 | kfree(ctx); | |
551 | } else | |
552 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
553 | "audit_pid=%d old=%d by auid=%u", | |
554 | status_get->pid, old, loginuid); | |
1da177e4 | 555 | audit_pid = status_get->pid; |
1da177e4 LT |
556 | } |
557 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) | |
5d136a01 | 558 | err = audit_set_rate_limit(status_get->rate_limit, |
ce29b682 | 559 | loginuid, sid); |
1da177e4 | 560 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
5d136a01 | 561 | err = audit_set_backlog_limit(status_get->backlog_limit, |
ce29b682 | 562 | loginuid, sid); |
1da177e4 | 563 | break; |
05474106 | 564 | case AUDIT_USER: |
209aba03 | 565 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
90d526c0 | 566 | case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2: |
4a4cd633 DW |
567 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
568 | return 0; | |
569 | ||
5bb289b5 | 570 | err = audit_filter_user(&NETLINK_CB(skb), msg_type); |
4a4cd633 DW |
571 | if (err == 1) { |
572 | err = 0; | |
9ad9ad38 | 573 | ab = audit_log_start(NULL, GFP_KERNEL, msg_type); |
4a4cd633 DW |
574 | if (ab) { |
575 | audit_log_format(ab, | |
e7c34970 SG |
576 | "user pid=%d uid=%u auid=%u", |
577 | pid, uid, loginuid); | |
578 | if (sid) { | |
e7c34970 SG |
579 | if (selinux_ctxid_to_string( |
580 | sid, &ctx, &len)) { | |
581 | audit_log_format(ab, | |
ce29b682 | 582 | " ssid=%u", sid); |
e7c34970 SG |
583 | /* Maybe call audit_panic? */ |
584 | } else | |
585 | audit_log_format(ab, | |
586 | " subj=%s", ctx); | |
587 | kfree(ctx); | |
588 | } | |
589 | audit_log_format(ab, " msg='%.1024s'", | |
590 | (char *)data); | |
4a4cd633 DW |
591 | audit_set_pid(ab, pid); |
592 | audit_log_end(ab); | |
593 | } | |
0f45aa18 | 594 | } |
1da177e4 LT |
595 | break; |
596 | case AUDIT_ADD: | |
597 | case AUDIT_DEL: | |
93315ed6 | 598 | if (nlmsg_len(nlh) < sizeof(struct audit_rule)) |
1da177e4 LT |
599 | return -EINVAL; |
600 | /* fallthrough */ | |
601 | case AUDIT_LIST: | |
1da177e4 | 602 | err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, |
93315ed6 | 603 | uid, seq, data, nlmsg_len(nlh), |
ce29b682 | 604 | loginuid, sid); |
93315ed6 AG |
605 | break; |
606 | case AUDIT_ADD_RULE: | |
607 | case AUDIT_DEL_RULE: | |
608 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
609 | return -EINVAL; | |
610 | /* fallthrough */ | |
611 | case AUDIT_LIST_RULES: | |
612 | err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, | |
613 | uid, seq, data, nlmsg_len(nlh), | |
ce29b682 | 614 | loginuid, sid); |
1da177e4 | 615 | break; |
c2f0c7c3 | 616 | case AUDIT_SIGNAL_INFO: |
e1396065 AV |
617 | err = selinux_ctxid_to_string(audit_sig_sid, &ctx, &len); |
618 | if (err) | |
619 | return err; | |
620 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); | |
621 | if (!sig_data) { | |
622 | kfree(ctx); | |
623 | return -ENOMEM; | |
624 | } | |
625 | sig_data->uid = audit_sig_uid; | |
626 | sig_data->pid = audit_sig_pid; | |
627 | memcpy(sig_data->ctx, ctx, len); | |
628 | kfree(ctx); | |
c2f0c7c3 | 629 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
630 | 0, 0, sig_data, sizeof(*sig_data) + len); |
631 | kfree(sig_data); | |
c2f0c7c3 | 632 | break; |
1da177e4 LT |
633 | default: |
634 | err = -EINVAL; | |
635 | break; | |
636 | } | |
637 | ||
638 | return err < 0 ? err : 0; | |
639 | } | |
640 | ||
b0dd25a8 RD |
641 | /* |
642 | * Get message from skb (based on rtnetlink_rcv_skb). Each message is | |
1da177e4 | 643 | * processed by audit_receive_msg. Malformed skbs with wrong length are |
b0dd25a8 RD |
644 | * discarded silently. |
645 | */ | |
2a0a6ebe | 646 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 LT |
647 | { |
648 | int err; | |
649 | struct nlmsghdr *nlh; | |
650 | u32 rlen; | |
651 | ||
652 | while (skb->len >= NLMSG_SPACE(0)) { | |
653 | nlh = (struct nlmsghdr *)skb->data; | |
654 | if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) | |
2a0a6ebe | 655 | return; |
1da177e4 LT |
656 | rlen = NLMSG_ALIGN(nlh->nlmsg_len); |
657 | if (rlen > skb->len) | |
658 | rlen = skb->len; | |
659 | if ((err = audit_receive_msg(skb, nlh))) { | |
660 | netlink_ack(skb, nlh, err); | |
661 | } else if (nlh->nlmsg_flags & NLM_F_ACK) | |
662 | netlink_ack(skb, nlh, 0); | |
663 | skb_pull(skb, rlen); | |
664 | } | |
1da177e4 LT |
665 | } |
666 | ||
667 | /* Receive messages from netlink socket. */ | |
668 | static void audit_receive(struct sock *sk, int length) | |
669 | { | |
670 | struct sk_buff *skb; | |
2a0a6ebe | 671 | unsigned int qlen; |
1da177e4 | 672 | |
f368c07d | 673 | mutex_lock(&audit_cmd_mutex); |
1da177e4 | 674 | |
2a0a6ebe HX |
675 | for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) { |
676 | skb = skb_dequeue(&sk->sk_receive_queue); | |
677 | audit_receive_skb(skb); | |
678 | kfree_skb(skb); | |
1da177e4 | 679 | } |
f368c07d | 680 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
681 | } |
682 | ||
f368c07d AG |
683 | #ifdef CONFIG_AUDITSYSCALL |
684 | static const struct inotify_operations audit_inotify_ops = { | |
685 | .handle_event = audit_handle_ievent, | |
686 | .destroy_watch = audit_free_parent, | |
687 | }; | |
688 | #endif | |
1da177e4 LT |
689 | |
690 | /* Initialize audit support at boot time. */ | |
691 | static int __init audit_init(void) | |
692 | { | |
f368c07d AG |
693 | #ifdef CONFIG_AUDITSYSCALL |
694 | int i; | |
695 | #endif | |
696 | ||
1da177e4 LT |
697 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
698 | audit_default ? "enabled" : "disabled"); | |
06628607 | 699 | audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive, |
4fdb3bb7 | 700 | THIS_MODULE); |
1da177e4 LT |
701 | if (!audit_sock) |
702 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
703 | else |
704 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 705 | |
b7d11258 | 706 | skb_queue_head_init(&audit_skb_queue); |
1da177e4 LT |
707 | audit_initialized = 1; |
708 | audit_enabled = audit_default; | |
3dc7e315 DG |
709 | |
710 | /* Register the callback with selinux. This callback will be invoked | |
711 | * when a new policy is loaded. */ | |
712 | selinux_audit_set_callback(&selinux_audit_rule_update); | |
713 | ||
9ad9ad38 | 714 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d AG |
715 | |
716 | #ifdef CONFIG_AUDITSYSCALL | |
717 | audit_ih = inotify_init(&audit_inotify_ops); | |
718 | if (IS_ERR(audit_ih)) | |
719 | audit_panic("cannot initialize inotify handle"); | |
720 | ||
721 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) | |
722 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
723 | #endif | |
724 | ||
1da177e4 LT |
725 | return 0; |
726 | } | |
1da177e4 LT |
727 | __initcall(audit_init); |
728 | ||
729 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
730 | static int __init audit_enable(char *str) | |
731 | { | |
732 | audit_default = !!simple_strtol(str, NULL, 0); | |
733 | printk(KERN_INFO "audit: %s%s\n", | |
734 | audit_default ? "enabled" : "disabled", | |
735 | audit_initialized ? "" : " (after initialization)"); | |
736 | if (audit_initialized) | |
737 | audit_enabled = audit_default; | |
9b41046c | 738 | return 1; |
1da177e4 LT |
739 | } |
740 | ||
741 | __setup("audit=", audit_enable); | |
742 | ||
16e1904e CW |
743 | static void audit_buffer_free(struct audit_buffer *ab) |
744 | { | |
745 | unsigned long flags; | |
746 | ||
8fc6115c CW |
747 | if (!ab) |
748 | return; | |
749 | ||
5ac52f33 CW |
750 | if (ab->skb) |
751 | kfree_skb(ab->skb); | |
b7d11258 | 752 | |
16e1904e | 753 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 754 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 755 | kfree(ab); |
5d136a01 SH |
756 | else { |
757 | audit_freelist_count++; | |
16e1904e | 758 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 759 | } |
16e1904e CW |
760 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
761 | } | |
762 | ||
c0404993 | 763 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 764 | gfp_t gfp_mask, int type) |
16e1904e CW |
765 | { |
766 | unsigned long flags; | |
767 | struct audit_buffer *ab = NULL; | |
c0404993 | 768 | struct nlmsghdr *nlh; |
16e1904e CW |
769 | |
770 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
771 | if (!list_empty(&audit_freelist)) { | |
772 | ab = list_entry(audit_freelist.next, | |
773 | struct audit_buffer, list); | |
774 | list_del(&ab->list); | |
775 | --audit_freelist_count; | |
776 | } | |
777 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
778 | ||
779 | if (!ab) { | |
4332bdd3 | 780 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 781 | if (!ab) |
8fc6115c | 782 | goto err; |
16e1904e | 783 | } |
8fc6115c | 784 | |
4332bdd3 | 785 | ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask); |
5ac52f33 | 786 | if (!ab->skb) |
8fc6115c CW |
787 | goto err; |
788 | ||
b7d11258 | 789 | ab->ctx = ctx; |
9ad9ad38 | 790 | ab->gfp_mask = gfp_mask; |
c0404993 SG |
791 | nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0)); |
792 | nlh->nlmsg_type = type; | |
793 | nlh->nlmsg_flags = 0; | |
794 | nlh->nlmsg_pid = 0; | |
795 | nlh->nlmsg_seq = 0; | |
16e1904e | 796 | return ab; |
8fc6115c CW |
797 | err: |
798 | audit_buffer_free(ab); | |
799 | return NULL; | |
16e1904e | 800 | } |
1da177e4 | 801 | |
b0dd25a8 RD |
802 | /** |
803 | * audit_serial - compute a serial number for the audit record | |
804 | * | |
805 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
806 | * written to user-space as soon as they are generated, so a complete |
807 | * audit record may be written in several pieces. The timestamp of the | |
808 | * record and this serial number are used by the user-space tools to | |
809 | * determine which pieces belong to the same audit record. The | |
810 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
811 | * syscall entry to syscall exit. | |
812 | * | |
bfb4496e DW |
813 | * NOTE: Another possibility is to store the formatted records off the |
814 | * audit context (for those records that have a context), and emit them | |
815 | * all at syscall exit. However, this could delay the reporting of | |
816 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
817 | * halts). |
818 | */ | |
bfb4496e DW |
819 | unsigned int audit_serial(void) |
820 | { | |
d5b454f2 DW |
821 | static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED; |
822 | static unsigned int serial = 0; | |
823 | ||
824 | unsigned long flags; | |
825 | unsigned int ret; | |
bfb4496e | 826 | |
d5b454f2 | 827 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 828 | do { |
ce625a80 DW |
829 | ret = ++serial; |
830 | } while (unlikely(!ret)); | |
d5b454f2 | 831 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 832 | |
d5b454f2 | 833 | return ret; |
bfb4496e DW |
834 | } |
835 | ||
836 | static inline void audit_get_stamp(struct audit_context *ctx, | |
837 | struct timespec *t, unsigned int *serial) | |
838 | { | |
839 | if (ctx) | |
840 | auditsc_get_stamp(ctx, t, serial); | |
841 | else { | |
842 | *t = CURRENT_TIME; | |
843 | *serial = audit_serial(); | |
844 | } | |
845 | } | |
846 | ||
1da177e4 LT |
847 | /* Obtain an audit buffer. This routine does locking to obtain the |
848 | * audit buffer, but then no locking is required for calls to | |
849 | * audit_log_*format. If the tsk is a task that is currently in a | |
850 | * syscall, then the syscall is marked as auditable and an audit record | |
851 | * will be written at syscall exit. If there is no associated task, tsk | |
852 | * should be NULL. */ | |
9ad9ad38 | 853 | |
b0dd25a8 RD |
854 | /** |
855 | * audit_log_start - obtain an audit buffer | |
856 | * @ctx: audit_context (may be NULL) | |
857 | * @gfp_mask: type of allocation | |
858 | * @type: audit message type | |
859 | * | |
860 | * Returns audit_buffer pointer on success or NULL on error. | |
861 | * | |
862 | * Obtain an audit buffer. This routine does locking to obtain the | |
863 | * audit buffer, but then no locking is required for calls to | |
864 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
865 | * syscall, then the syscall is marked as auditable and an audit record | |
866 | * will be written at syscall exit. If there is no associated task, then | |
867 | * task context (ctx) should be NULL. | |
868 | */ | |
9796fdd8 | 869 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 870 | int type) |
1da177e4 LT |
871 | { |
872 | struct audit_buffer *ab = NULL; | |
1da177e4 | 873 | struct timespec t; |
d812ddbb | 874 | unsigned int serial; |
9ad9ad38 | 875 | int reserve; |
ac4cec44 | 876 | unsigned long timeout_start = jiffies; |
1da177e4 LT |
877 | |
878 | if (!audit_initialized) | |
879 | return NULL; | |
880 | ||
c8edc80c DK |
881 | if (unlikely(audit_filter_type(type))) |
882 | return NULL; | |
883 | ||
9ad9ad38 DW |
884 | if (gfp_mask & __GFP_WAIT) |
885 | reserve = 0; | |
886 | else | |
887 | reserve = 5; /* Allow atomic callers to go up to five | |
888 | entries over the normal backlog limit */ | |
889 | ||
890 | while (audit_backlog_limit | |
891 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
ac4cec44 DW |
892 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time |
893 | && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { | |
894 | ||
9ad9ad38 DW |
895 | /* Wait for auditd to drain the queue a little */ |
896 | DECLARE_WAITQUEUE(wait, current); | |
897 | set_current_state(TASK_INTERRUPTIBLE); | |
898 | add_wait_queue(&audit_backlog_wait, &wait); | |
899 | ||
900 | if (audit_backlog_limit && | |
901 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ac4cec44 | 902 | schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); |
9ad9ad38 DW |
903 | |
904 | __set_current_state(TASK_RUNNING); | |
905 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ac4cec44 | 906 | continue; |
9ad9ad38 | 907 | } |
fb19b4c6 DW |
908 | if (audit_rate_check()) |
909 | printk(KERN_WARNING | |
910 | "audit: audit_backlog=%d > " | |
911 | "audit_backlog_limit=%d\n", | |
912 | skb_queue_len(&audit_skb_queue), | |
913 | audit_backlog_limit); | |
914 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
915 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
916 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
917 | return NULL; |
918 | } | |
919 | ||
9ad9ad38 | 920 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
921 | if (!ab) { |
922 | audit_log_lost("out of memory in audit_log_start"); | |
923 | return NULL; | |
924 | } | |
925 | ||
bfb4496e | 926 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 927 | |
1da177e4 LT |
928 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
929 | t.tv_sec, t.tv_nsec/1000000, serial); | |
930 | return ab; | |
931 | } | |
932 | ||
8fc6115c | 933 | /** |
5ac52f33 | 934 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 935 | * @ab: audit_buffer |
b0dd25a8 | 936 | * @extra: space to add at tail of the skb |
8fc6115c CW |
937 | * |
938 | * Returns 0 (no space) on failed expansion, or available space if | |
939 | * successful. | |
940 | */ | |
e3b926b4 | 941 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 942 | { |
5ac52f33 | 943 | struct sk_buff *skb = ab->skb; |
e3b926b4 | 944 | int ret = pskb_expand_head(skb, skb_headroom(skb), extra, |
9ad9ad38 | 945 | ab->gfp_mask); |
5ac52f33 CW |
946 | if (ret < 0) { |
947 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 948 | return 0; |
5ac52f33 CW |
949 | } |
950 | return skb_tailroom(skb); | |
8fc6115c | 951 | } |
1da177e4 | 952 | |
b0dd25a8 RD |
953 | /* |
954 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
955 | * room in the audit buffer, more room will be allocated and vsnprint |
956 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
957 | * can't format message larger than 1024 bytes, so we don't either. |
958 | */ | |
1da177e4 LT |
959 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
960 | va_list args) | |
961 | { | |
962 | int len, avail; | |
5ac52f33 | 963 | struct sk_buff *skb; |
eecb0a73 | 964 | va_list args2; |
1da177e4 LT |
965 | |
966 | if (!ab) | |
967 | return; | |
968 | ||
5ac52f33 CW |
969 | BUG_ON(!ab->skb); |
970 | skb = ab->skb; | |
971 | avail = skb_tailroom(skb); | |
972 | if (avail == 0) { | |
e3b926b4 | 973 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
974 | if (!avail) |
975 | goto out; | |
1da177e4 | 976 | } |
eecb0a73 | 977 | va_copy(args2, args); |
5ac52f33 | 978 | len = vsnprintf(skb->tail, avail, fmt, args); |
1da177e4 LT |
979 | if (len >= avail) { |
980 | /* The printk buffer is 1024 bytes long, so if we get | |
981 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
982 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
983 | avail = audit_expand(ab, |
984 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c CW |
985 | if (!avail) |
986 | goto out; | |
eecb0a73 | 987 | len = vsnprintf(skb->tail, avail, fmt, args2); |
1da177e4 | 988 | } |
168b7173 SG |
989 | if (len > 0) |
990 | skb_put(skb, len); | |
8fc6115c CW |
991 | out: |
992 | return; | |
1da177e4 LT |
993 | } |
994 | ||
b0dd25a8 RD |
995 | /** |
996 | * audit_log_format - format a message into the audit buffer. | |
997 | * @ab: audit_buffer | |
998 | * @fmt: format string | |
999 | * @...: optional parameters matching @fmt string | |
1000 | * | |
1001 | * All the work is done in audit_log_vformat. | |
1002 | */ | |
1da177e4 LT |
1003 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1004 | { | |
1005 | va_list args; | |
1006 | ||
1007 | if (!ab) | |
1008 | return; | |
1009 | va_start(args, fmt); | |
1010 | audit_log_vformat(ab, fmt, args); | |
1011 | va_end(args); | |
1012 | } | |
1013 | ||
b0dd25a8 RD |
1014 | /** |
1015 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1016 | * @ab: the audit_buffer | |
1017 | * @buf: buffer to convert to hex | |
1018 | * @len: length of @buf to be converted | |
1019 | * | |
1020 | * No return value; failure to expand is silently ignored. | |
1021 | * | |
1022 | * This function will take the passed buf and convert it into a string of | |
1023 | * ascii hex digits. The new string is placed onto the skb. | |
1024 | */ | |
1025 | void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, | |
168b7173 | 1026 | size_t len) |
83c7d091 | 1027 | { |
168b7173 SG |
1028 | int i, avail, new_len; |
1029 | unsigned char *ptr; | |
1030 | struct sk_buff *skb; | |
1031 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1032 | ||
1033 | BUG_ON(!ab->skb); | |
1034 | skb = ab->skb; | |
1035 | avail = skb_tailroom(skb); | |
1036 | new_len = len<<1; | |
1037 | if (new_len >= avail) { | |
1038 | /* Round the buffer request up to the next multiple */ | |
1039 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1040 | avail = audit_expand(ab, new_len); | |
1041 | if (!avail) | |
1042 | return; | |
1043 | } | |
83c7d091 | 1044 | |
168b7173 SG |
1045 | ptr = skb->tail; |
1046 | for (i=0; i<len; i++) { | |
1047 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1048 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1049 | } | |
1050 | *ptr = 0; | |
1051 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1052 | } |
1053 | ||
9c937dcc AG |
1054 | /* |
1055 | * Format a string of no more than slen characters into the audit buffer, | |
1056 | * enclosed in quote marks. | |
1057 | */ | |
1058 | static void audit_log_n_string(struct audit_buffer *ab, size_t slen, | |
1059 | const char *string) | |
1060 | { | |
1061 | int avail, new_len; | |
1062 | unsigned char *ptr; | |
1063 | struct sk_buff *skb; | |
1064 | ||
1065 | BUG_ON(!ab->skb); | |
1066 | skb = ab->skb; | |
1067 | avail = skb_tailroom(skb); | |
1068 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1069 | if (new_len > avail) { | |
1070 | avail = audit_expand(ab, new_len); | |
1071 | if (!avail) | |
1072 | return; | |
1073 | } | |
1074 | ptr = skb->tail; | |
1075 | *ptr++ = '"'; | |
1076 | memcpy(ptr, string, slen); | |
1077 | ptr += slen; | |
1078 | *ptr++ = '"'; | |
1079 | *ptr = 0; | |
1080 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1081 | } | |
1082 | ||
b0dd25a8 | 1083 | /** |
9c937dcc | 1084 | * audit_log_n_unstrustedstring - log a string that may contain random characters |
b0dd25a8 | 1085 | * @ab: audit_buffer |
9c937dcc | 1086 | * @len: lenth of string (not including trailing null) |
b0dd25a8 RD |
1087 | * @string: string to be logged |
1088 | * | |
1089 | * This code will escape a string that is passed to it if the string | |
1090 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1091 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1092 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1093 | * |
1094 | * The caller specifies the number of characters in the string to log, which may | |
1095 | * or may not be the entire string. | |
b0dd25a8 | 1096 | */ |
9c937dcc AG |
1097 | const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, |
1098 | const char *string) | |
83c7d091 | 1099 | { |
81b7854d | 1100 | const unsigned char *p = string; |
83c7d091 | 1101 | |
1102 | while (*p) { | |
168b7173 | 1103 | if (*p == '"' || *p < 0x21 || *p > 0x7f) { |
473ae30b AV |
1104 | audit_log_hex(ab, string, len); |
1105 | return string + len + 1; | |
83c7d091 | 1106 | } |
1107 | p++; | |
1108 | } | |
9c937dcc | 1109 | audit_log_n_string(ab, len, string); |
473ae30b | 1110 | return p + 1; |
83c7d091 | 1111 | } |
1112 | ||
9c937dcc AG |
1113 | /** |
1114 | * audit_log_unstrustedstring - log a string that may contain random characters | |
1115 | * @ab: audit_buffer | |
1116 | * @string: string to be logged | |
1117 | * | |
1118 | * Same as audit_log_n_unstrustedstring(), except that strlen is used to | |
1119 | * determine string length. | |
1120 | */ | |
1121 | const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string) | |
1122 | { | |
1123 | return audit_log_n_untrustedstring(ab, strlen(string), string); | |
1124 | } | |
1125 | ||
168b7173 | 1126 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 LT |
1127 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
1128 | struct dentry *dentry, struct vfsmount *vfsmnt) | |
1129 | { | |
168b7173 | 1130 | char *p, *path; |
1da177e4 | 1131 | |
8fc6115c CW |
1132 | if (prefix) |
1133 | audit_log_format(ab, " %s", prefix); | |
1da177e4 | 1134 | |
168b7173 | 1135 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
9ad9ad38 | 1136 | path = kmalloc(PATH_MAX+11, ab->gfp_mask); |
168b7173 SG |
1137 | if (!path) { |
1138 | audit_log_format(ab, "<no memory>"); | |
1139 | return; | |
1da177e4 | 1140 | } |
168b7173 SG |
1141 | p = d_path(dentry, vfsmnt, path, PATH_MAX+11); |
1142 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ | |
1143 | /* FIXME: can we save some information here? */ | |
1144 | audit_log_format(ab, "<too long>"); | |
1145 | } else | |
1146 | audit_log_untrustedstring(ab, p); | |
1147 | kfree(path); | |
1da177e4 LT |
1148 | } |
1149 | ||
b0dd25a8 RD |
1150 | /** |
1151 | * audit_log_end - end one audit record | |
1152 | * @ab: the audit_buffer | |
1153 | * | |
1154 | * The netlink_* functions cannot be called inside an irq context, so | |
1155 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1156 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1157 | * any context. |
1158 | */ | |
b7d11258 | 1159 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1160 | { |
1da177e4 LT |
1161 | if (!ab) |
1162 | return; | |
1163 | if (!audit_rate_check()) { | |
1164 | audit_log_lost("rate limit exceeded"); | |
1165 | } else { | |
b7d11258 DW |
1166 | if (audit_pid) { |
1167 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; | |
1168 | nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); | |
1169 | skb_queue_tail(&audit_skb_queue, ab->skb); | |
1170 | ab->skb = NULL; | |
1171 | wake_up_interruptible(&kauditd_wait); | |
1172 | } else { | |
e1b09eba | 1173 | printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0)); |
b7d11258 | 1174 | } |
1da177e4 | 1175 | } |
16e1904e | 1176 | audit_buffer_free(ab); |
1da177e4 LT |
1177 | } |
1178 | ||
b0dd25a8 RD |
1179 | /** |
1180 | * audit_log - Log an audit record | |
1181 | * @ctx: audit context | |
1182 | * @gfp_mask: type of allocation | |
1183 | * @type: audit message type | |
1184 | * @fmt: format string to use | |
1185 | * @...: variable parameters matching the format string | |
1186 | * | |
1187 | * This is a convenience function that calls audit_log_start, | |
1188 | * audit_log_vformat, and audit_log_end. It may be called | |
1189 | * in any context. | |
1190 | */ | |
9796fdd8 | 1191 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1192 | const char *fmt, ...) |
1da177e4 LT |
1193 | { |
1194 | struct audit_buffer *ab; | |
1195 | va_list args; | |
1196 | ||
9ad9ad38 | 1197 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1198 | if (ab) { |
1199 | va_start(args, fmt); | |
1200 | audit_log_vformat(ab, fmt, args); | |
1201 | va_end(args); | |
1202 | audit_log_end(ab); | |
1203 | } | |
1204 | } | |
bf45da97 | 1205 | |
1206 | EXPORT_SYMBOL(audit_log_start); | |
1207 | EXPORT_SYMBOL(audit_log_end); | |
1208 | EXPORT_SYMBOL(audit_log_format); | |
1209 | EXPORT_SYMBOL(audit_log); |