xref: /illumos-gate/usr/src/uts/common/c2/audit_kernel.h (revision 3299f39fdcbdab4be7a9c70daa3873f2b78a398d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #ifndef _BSM_AUDIT_KERNEL_H
26 #define	_BSM_AUDIT_KERNEL_H
27 
28 
29 /*
30  * This file contains the basic auditing control structure definitions.
31  */
32 
33 #include <c2/audit_kevents.h>
34 #include <sys/priv_impl.h>
35 #include <sys/taskq.h>
36 #include <sys/zone.h>
37 
38 #include <sys/tsol/label.h>
39 
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * This table contains the mapping from the system call ID to a corresponding
46  * audit event.
47  *
48  *   au_init() is a function called at the beginning of the system call that
49  *   performs any necessary setup/processing. It maps the call into the
50  *   appropriate event, depending on the system call arguments. It is called
51  *   by audit_start() from trap.c .
52  *
53  *   au_event is the audit event associated with the system call. Most of the
54  *   time it will map directly from the system call i.e. There is one system
55  *   call associated with the event. In some cases, such as shmsys, or open,
56  *   the au_start() function will map the system call to more than one event,
57  *   depending on the system call arguments.
58  *
59  *   au_start() is a function that provides per system call processing at the
60  *   beginning of a system call. It is mainly concerned with preseving the
61  *   audit record components that may be altered so that we can determine
62  *   what the original paramater was before as well as after the system call.
63  *   It is possible that au_start() may be taken away. It might be cleaner to
64  *   define flags in au_ctrl to save a designated argument. For the moment we
65  *   support both mechanisms, however the use of au_start() will be reviewed
66  *   for 4.1.1 and CMW and ZEUS to see if such a general method is justified.
67  *
68  *   au_finish() is a function that provides per system call processing at the
69  *   completion of a system call. In certain circumstances, the type of audit
70  *   event depends on intermidiate results during the processing of the system
71  *   call. It is called in audit_finish() from trap.c .
72  *
73  *   au_ctrl is a control vector that indicates what processing might have to
74  *   be performed, even if there is no auditing for this system call. At
75  *   present this is mostly for path processing for chmod, chroot. We need to
76  *   process the path information in vfs_lookup, even when we are not auditing
77  *   the system call in the case of chdir and chroot.
78  */
79 /*
80  * Defines for au_ctrl
81  */
82 #define	S2E_SP  TAD_SAVPATH	/* save path for later use */
83 #define	S2E_MLD TAD_MLD		/* only one lookup per system call */
84 #define	S2E_NPT TAD_NOPATH	/* force no path in audit record */
85 #define	S2E_PUB TAD_PUBLIC_EV	/* syscall is defined as a public op */
86 
87 /*
88  * At present, we are using the audit classes imbedded with in the kernel. Each
89  * event has a bit mask determining which classes the event is associated.
90  * The table audit_e2s maps the audit event ID to the audit state.
91  *
92  * Note that this may change radically. If we use a bit vector for the audit
93  * class, we can allow granularity at the event ID for each user. In this
94  * case, the vector would be determined at user level and passed to the kernel
95  * via the setaudit system call.
96  */
97 
98 /*
99  * The audit_pad structure holds paths for the current root and directory
100  * for the process, as well as for open files and directly manipulated objects.
101  * The reference count minimizes data copies since the process's current
102  * directory changes very seldom.
103  */
104 struct audit_path {
105 	uint_t		audp_ref;	/* reference count */
106 	uint_t		audp_size;	/* allocated size of this structure */
107 	uint_t		audp_cnt;	/* number of path sections */
108 	char		*audp_sect[1];	/* path section pointers */
109 					/* audp_sect[0] is the path name */
110 					/* audp_sect[1+] are attribute paths */
111 };
112 
113 /*
114  * The structure of the terminal ID within the kernel is different from the
115  * terminal ID in user space. It is a combination of port and IP address.
116  */
117 
118 struct au_termid {
119 	dev_t	at_port;
120 	uint_t	at_type;
121 	uint_t	at_addr[4];
122 };
123 typedef struct au_termid au_termid_t;
124 
125 /*
126  * Attributes for deferring the queuing of an event.
127  */
128 typedef struct au_defer_info {
129 	struct au_defer_info	*audi_next;	/* next on linked list */
130 	void	 *audi_ad;		/* audit record */
131 	au_event_t	audi_e_type;	/* audit event id */
132 	au_emod_t	audi_e_mod;	/* audit event modifier */
133 	int	audi_flag;		/* au_close*() flags */
134 	timestruc_t	audi_atime;	/* audit event timestamp */
135 } au_defer_info_t;
136 
137 /*
138  * The structure p_audit_data hangs off of the process structure. It contains
139  * all of the audit information necessary to manage the audit record generation
140  * for each process.
141  *
142  * The pad_lock is constructed in the kmem_cache; the rest is combined
143  * in a sub structure so it can be copied/zeroed in one statement.
144  *
145  * The members have been reordered for maximum packing on 64 bit Solaris.
146  */
147 struct p_audit_data {
148 	kmutex_t	pad_lock;	/* lock pad data during changes */
149 	struct _pad_data {
150 		struct audit_path	*pad_root;	/* process root path */
151 		struct audit_path	*pad_cwd;	/* process cwd path */
152 		au_mask_t		pad_newmask;	/* pending new mask */
153 		int			pad_flags;
154 	} pad_data;
155 };
156 typedef struct p_audit_data p_audit_data_t;
157 
158 #define	pad_root	pad_data.pad_root
159 #define	pad_cwd		pad_data.pad_cwd
160 #define	pad_newmask	pad_data.pad_newmask
161 #define	pad_flags	pad_data.pad_flags
162 
163 /*
164  * Defines for process audit flags (pad_flags)
165  */
166 #define	PAD_SETMASK 	0x00000001	/* need to complete pending setmask */
167 
168 extern kmem_cache_t *au_pad_cache;
169 
170 /*
171  * Defines for thread audit control/status flags (tad_ctrl)
172  */
173 #define	TAD_ABSPATH 	0x00000001	/* path from lookup is absolute */
174 #define	TAD_ATCALL	0x00000002	/* *at() syscall, like openat() */
175 #define	TAD_ATTPATH  	0x00000004	/* attribute file lookup */
176 #define	TAD_CORE	0x00000008	/* save attribute during core dump */
177 #define	TAD_ERRJMP	0x00000010	/* abort record generation on error */
178 #define	TAD_MLD		0x00000020	/* system call involves MLD */
179 #define	TAD_NOATTRB 	0x00000040	/* do not automatically add attribute */
180 #define	TAD_NOAUDIT 	0x00000080	/* discard audit record */
181 #define	TAD_NOPATH  	0x00000100	/* force no paths in audit record */
182 #define	TAD_PATHFND 	0x00000200	/* found path, don't retry lookup */
183 #define	TAD_PUBLIC_EV	0x00000400	/* syscall is defined as a public op */
184 #define	TAD_SAVPATH 	0x00000800	/* save path for further processing */
185 #define	TAD_TRUE_CREATE 0x00001000	/* true create, file not found */
186 
187 /*
188  * The structure t_audit_data hangs off of the thread structure. It contains
189  * all of the audit information necessary to manage the audit record generation
190  * for each thread.
191  *
192  */
193 
194 struct t_audit_data {
195 	kthread_id_t  tad_thread;	/* DEBUG pointer to parent thread */
196 	unsigned int  tad_scid;		/* system call ID for finish */
197 	au_event_t	tad_event;	/* event for audit record */
198 	au_emod_t	tad_evmod;	/* event modifier for audit record */
199 	int	tad_ctrl;	/* audit control/status flags */
200 	void	*tad_errjmp;	/* error longjmp (audit record aborted) */
201 	int	tad_flag;	/* to audit or not to audit */
202 	uint32_t tad_audit;	/* auditing enabled/disabled */
203 	struct audit_path	*tad_aupath;	/* captured at vfs_lookup */
204 	struct audit_path	*tad_atpath;	/* openat prefix, path of fd */
205 	caddr_t tad_ad;		/* base of accumulated audit data */
206 	au_defer_info_t	*tad_defer_head;	/* queue of records to defer */
207 						/* until syscall end: */
208 	au_defer_info_t	*tad_defer_tail;	/* tail of defer queue */
209 	priv_set_t tad_sprivs;	/* saved (success) used privs */
210 	priv_set_t tad_fprivs;	/* saved (failed) used privs */
211 };
212 typedef struct t_audit_data t_audit_data_t;
213 
214 /*
215  * The f_audit_data structure hangs off of the file structure. It contains
216  * three fields of data. The audit ID, the audit state, and a path name.
217  */
218 
219 struct f_audit_data {
220 	kthread_id_t	fad_thread;	/* DEBUG creating thread */
221 	int		fad_flags;	/* audit control flags */
222 	struct audit_path	*fad_aupath;	/* path from vfs_lookup */
223 };
224 typedef struct f_audit_data f_audit_data_t;
225 
226 #define	FAD_READ	0x0001		/* read system call seen */
227 #define	FAD_WRITE	0x0002		/* write system call seen */
228 
229 #define	P2A(p)	(p->p_audit_data)
230 #define	T2A(t)	(t->t_audit_data)
231 #define	U2A(u)	(curthread->t_audit_data)
232 #define	F2A(f)	(f->f_audit_data)
233 
234 #define	u_ad    ((U2A(u))->tad_ad)
235 #define	ad_ctrl ((U2A(u))->tad_ctrl)
236 #define	ad_flag ((U2A(u))->tad_flag)
237 
238 #define	AU_BUFSIZE	128		/* buffer size for the buffer pool */
239 
240 struct au_buff {
241 	char		buf[AU_BUFSIZE];
242 	struct au_buff	*next_buf;
243 	struct au_buff	*next_rec;
244 	ushort_t	rec_len;
245 	uchar_t		len;
246 	uchar_t		flag;
247 };
248 
249 typedef struct au_buff au_buff_t;
250 
251 /*
252  * Kernel audit queue structure.
253  */
254 struct audit_queue {
255 	au_buff_t *head;	/* head of queue */
256 	au_buff_t *tail;	/* tail of queue */
257 	ssize_t	cnt;		/* number elements on queue */
258 	size_t	hiwater;	/* high water mark to block */
259 	size_t	lowater;	/* low water mark to restart */
260 	size_t	bufsz;		/* audit trail write buffer size */
261 	size_t	buflen;		/* audit trail buffer length in use */
262 	clock_t	delay;		/* delay before flushing queue */
263 	int	wt_block;	/* writer is blocked (1) */
264 	int	rd_block;	/* reader is blocked (1) */
265 	kmutex_t lock;		/* mutex lock for queue modification */
266 	kcondvar_t write_cv;	/* sleep structure for write block */
267 	kcondvar_t read_cv;	/* sleep structure for read block */
268 };
269 
270 
271 union rval;
272 struct audit_s2e {
273 	au_event_t (*au_init)(au_event_t);
274 				/* convert au_event to real audit event ID */
275 
276 	int au_event;		/* default audit event for this system call */
277 	void (*au_start)(struct t_audit_data *);
278 				/* pre-system call audit processing */
279 	void (*au_finish)(struct t_audit_data *, int, union rval *);
280 				/* post-system call audit processing */
281 	int au_ctrl;		/* control flags for auditing actions */
282 };
283 
284 extern struct audit_s2e audit_s2e[];
285 
286 #define	AUK_VALID	0x5A5A5A5A
287 #define	AUK_INVALID	0
288 /*
289  * per zone audit context
290  */
291 struct au_kcontext {
292 	uint32_t		auk_valid;
293 	zoneid_t		auk_zid;
294 
295 	boolean_t		auk_hostaddr_valid;
296 	int			auk_sequence;
297 	int			auk_auditstate;
298 	int			auk_output_active;
299 	struct vnode		*auk_current_vp;
300 	uint32_t		auk_policy;
301 
302 	struct audit_queue	auk_queue;
303 
304 	au_dbuf_t		*auk_dbuffer;	/* auditdoor output */
305 
306 	au_stat_t		auk_statistics;
307 
308 	k_auditinfo_addr_t	auk_info;
309 	kmutex_t		auk_eagain_mutex; /* door call retry */
310 	kcondvar_t		auk_eagain_cv;
311 
312 	taskq_t			*auk_taskq;	/* output thread */
313 
314 	/* Only one audit svc per zone at a time */
315 	/* With the elimination of auditsvc, can this also go? see 6648414 */
316 	kmutex_t 		auk_svc_lock;
317 
318 	au_state_t		auk_ets[MAX_KEVENTS + 1];
319 };
320 #ifndef AUK_CONTEXT_T
321 #define	AUK_CONTEXT_T
322 typedef struct au_kcontext au_kcontext_t;
323 #endif
324 
325 extern zone_key_t au_zone_key;
326 
327 /*
328  * Kernel auditing external variables
329  */
330 extern uint32_t audit_policy;
331 extern int audit_active;
332 
333 extern struct audit_queue au_queue;
334 extern struct p_audit_data *pad0;
335 extern struct t_audit_data *tad0;
336 
337 /*
338  * audit_path support routines
339  */
340 void au_pathhold(struct audit_path *);
341 void au_pathrele(struct audit_path *);
342 struct audit_path *au_pathdup(const struct audit_path *, int, int);
343 
344 void au_pad_init(void);
345 
346 int auditctl(int cmd, caddr_t data, int length);
347 int auditdoor(int fd);
348 int getauid(caddr_t);
349 int setauid(caddr_t);
350 int getaudit(caddr_t);
351 int getaudit_addr(caddr_t, int);
352 int setaudit(caddr_t);
353 int setaudit_addr(caddr_t, int);
354 
355 /*
356  * Macros to hide asynchronous, non-blocking audit record start and finish
357  * processing.
358  *
359  * NOTE: must be used in (void) funcction () { ... }
360  */
361 
362 #define	AUDIT_ASYNC_START(rp, audit_event, sorf) \
363 { \
364 	label_t jb; \
365 	if (setjmp(&jb)) { \
366 		/* cleanup any residual audit data */ \
367 		audit_async_drop((caddr_t *)&(rp), 0); \
368 		return; \
369 	} \
370 	/* auditing enabled and we're preselected for this event? */ \
371 	if (audit_async_start(&jb, audit_event, sorf)) { \
372 		return; \
373 	} \
374 }
375 
376 #define	AUDIT_ASYNC_FINISH(rp, audit_event, event_modifier, event_time) \
377 	audit_async_finish((caddr_t *)&(rp), audit_event, event_modifier, \
378 	event_time);
379 
380 
381 #ifdef	_KERNEL
382 au_buff_t *au_get_buff(void), *au_free_buff(au_buff_t *);
383 #endif
384 
385 /*
386  * Macro for uniform "subject" token(s) generation
387  */
388 #define	AUDIT_SETSUBJ_GENERIC(u, c, a, k, p)		\
389 	(au_write((u), au_to_subject(crgetuid(c),	\
390 	    crgetgid(c), crgetruid(c), crgetrgid(c),	\
391 	    p, (a)->ai_auid, (a)->ai_asid,		\
392 	    &((a)->ai_termid))));			\
393 	((is_system_labeled()) ?  au_write((u),		\
394 	    au_to_label(CR_SL((c)))) : (void) 0);	\
395 	(((k)->auk_policy & AUDIT_GROUP) ? au_write((u),\
396 	    au_to_groups(crgetgroups(c),		\
397 	    crgetngroups(c))) : (void) 0)
398 
399 #define	AUDIT_SETSUBJ(u, c, a, k)      		\
400 	AUDIT_SETSUBJ_GENERIC(u, c, a, k, curproc->p_pid)
401 
402 #define	AUDIT_SETPROC_GENERIC(u, c, a, p)		\
403 	(au_write((u), au_to_process(crgetuid(c),	\
404 	    crgetgid(c), crgetruid(c), crgetrgid(c),	\
405 	    p, (a)->ai_auid, (a)->ai_asid,		\
406 	    &((a)->ai_termid))));
407 
408 #define	AUDIT_SETPROC(u, c, a)      		\
409 	AUDIT_SETPROC_GENERIC(u, c, a, curproc->p_pid)
410 
411 /*
412  * Macros for type conversion
413  */
414 
415 /* au_membuf head, to typed data */
416 #define	memtod(x, t)	((t)x->buf)
417 
418 /* au_membuf types */
419 #define	MT_FREE		0	/* should be on free list */
420 #define	MT_DATA		1	/* dynamic (data) allocation */
421 
422 /* flags to au_memget */
423 #define	DONTWAIT	0
424 #define	WAIT		1
425 
426 #define	AU_PACK	1	/* pack data in au_append_rec() */
427 #define	AU_LINK 0	/* link data in au_append_rec() */
428 
429 /* flags to async routines */
430 #define	AU_BACKEND	1	/* called from softcall backend */
431 
432 #ifdef __cplusplus
433 }
434 #endif
435 
436 #endif /* _BSM_AUDIT_KERNEL_H */
437