xref: /illumos-gate/usr/src/uts/common/c2/audit_kernel.h (revision 89b42a211fa7d3527b9615260f495d22e430c5c5)
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 #define	S2E_ATC	TAD_ATCALL	/* syscall is one of the *at() family */
87 
88 /*
89  * At present, we are using the audit classes imbedded with in the kernel. Each
90  * event has a bit mask determining which classes the event is associated.
91  * The table audit_e2s maps the audit event ID to the audit state.
92  *
93  * Note that this may change radically. If we use a bit vector for the audit
94  * class, we can allow granularity at the event ID for each user. In this
95  * case, the vector would be determined at user level and passed to the kernel
96  * via the setaudit system call.
97  */
98 
99 /*
100  * The audit_pad structure holds paths for the current root and directory
101  * for the process, as well as for open files and directly manipulated objects.
102  * The reference count minimizes data copies since the process's current
103  * directory changes very seldom.
104  */
105 struct audit_path {
106 	uint_t		audp_ref;	/* reference count */
107 	uint_t		audp_size;	/* allocated size of this structure */
108 	uint_t		audp_cnt;	/* number of path sections */
109 	char		*audp_sect[1];	/* path section pointers */
110 					/* audp_sect[0] is the path name */
111 					/* audp_sect[1+] are attribute paths */
112 };
113 
114 /*
115  * The structure of the terminal ID within the kernel is different from the
116  * terminal ID in user space. It is a combination of port and IP address.
117  */
118 
119 struct au_termid {
120 	dev_t	at_port;
121 	uint_t	at_type;
122 	uint_t	at_addr[4];
123 };
124 typedef struct au_termid au_termid_t;
125 
126 /*
127  * Attributes for deferring the queuing of an event.
128  */
129 typedef struct au_defer_info {
130 	struct au_defer_info	*audi_next;	/* next on linked list */
131 	void	 *audi_ad;		/* audit record */
132 	au_event_t	audi_e_type;	/* audit event id */
133 	au_emod_t	audi_e_mod;	/* audit event modifier */
134 	int	audi_flag;		/* au_close*() flags */
135 	timestruc_t	audi_atime;	/* audit event timestamp */
136 } au_defer_info_t;
137 
138 /*
139  * The structure p_audit_data hangs off of the process structure. It contains
140  * all of the audit information necessary to manage the audit record generation
141  * for each process.
142  *
143  * The pad_lock is constructed in the kmem_cache; the rest is combined
144  * in a sub structure so it can be copied/zeroed in one statement.
145  *
146  * The members have been reordered for maximum packing on 64 bit Solaris.
147  */
148 struct p_audit_data {
149 	kmutex_t	pad_lock;	/* lock pad data during changes */
150 	struct _pad_data {
151 		struct audit_path	*pad_root;	/* process root path */
152 		struct audit_path	*pad_cwd;	/* process cwd path */
153 		au_mask_t		pad_newmask;	/* pending new mask */
154 		int			pad_flags;
155 	} pad_data;
156 };
157 typedef struct p_audit_data p_audit_data_t;
158 
159 #define	pad_root	pad_data.pad_root
160 #define	pad_cwd		pad_data.pad_cwd
161 #define	pad_newmask	pad_data.pad_newmask
162 #define	pad_flags	pad_data.pad_flags
163 
164 /*
165  * Defines for process audit flags (pad_flags)
166  */
167 #define	PAD_SETMASK 	0x00000001	/* need to complete pending setmask */
168 
169 extern kmem_cache_t *au_pad_cache;
170 
171 /*
172  * Defines for thread audit control/status flags (tad_ctrl)
173  */
174 #define	TAD_ABSPATH 	0x00000001	/* path from lookup is absolute */
175 #define	TAD_ATCALL	0x00000002	/* *at() syscall, like openat() */
176 #define	TAD_ATTPATH  	0x00000004	/* attribute file lookup */
177 #define	TAD_CORE	0x00000008	/* save attribute during core dump */
178 #define	TAD_ERRJMP	0x00000010	/* abort record generation on error */
179 #define	TAD_MLD		0x00000020	/* system call involves MLD */
180 #define	TAD_NOATTRB 	0x00000040	/* do not automatically add attribute */
181 #define	TAD_NOAUDIT 	0x00000080	/* discard audit record */
182 #define	TAD_NOPATH  	0x00000100	/* force no paths in audit record */
183 #define	TAD_PATHFND 	0x00000200	/* found path, don't retry lookup */
184 #define	TAD_PUBLIC_EV	0x00000400	/* syscall is defined as a public op */
185 #define	TAD_SAVPATH 	0x00000800	/* save path for further processing */
186 #define	TAD_TRUE_CREATE 0x00001000	/* true create, file not found */
187 
188 /*
189  * The structure t_audit_data hangs off of the thread structure. It contains
190  * all of the audit information necessary to manage the audit record generation
191  * for each thread.
192  *
193  */
194 
195 struct t_audit_data {
196 	kthread_id_t  tad_thread;	/* DEBUG pointer to parent thread */
197 	unsigned int  tad_scid;		/* system call ID for finish */
198 	au_event_t	tad_event;	/* event for audit record */
199 	au_emod_t	tad_evmod;	/* event modifier for audit record */
200 	int	tad_ctrl;	/* audit control/status flags */
201 	void	*tad_errjmp;	/* error longjmp (audit record aborted) */
202 	int	tad_flag;	/* to audit or not to audit */
203 	uint32_t tad_audit;	/* auditing enabled/disabled */
204 	struct audit_path	*tad_aupath;	/* captured at vfs_lookup */
205 	struct audit_path	*tad_atpath;	/* openat prefix, path of fd */
206 	caddr_t tad_ad;		/* base of accumulated audit data */
207 	au_defer_info_t	*tad_defer_head;	/* queue of records to defer */
208 						/* until syscall end: */
209 	au_defer_info_t	*tad_defer_tail;	/* tail of defer queue */
210 	priv_set_t tad_sprivs;	/* saved (success) used privs */
211 	priv_set_t tad_fprivs;	/* saved (failed) used privs */
212 };
213 typedef struct t_audit_data t_audit_data_t;
214 
215 /*
216  * The f_audit_data structure hangs off of the file structure. It contains
217  * three fields of data. The audit ID, the audit state, and a path name.
218  */
219 
220 struct f_audit_data {
221 	kthread_id_t	fad_thread;	/* DEBUG creating thread */
222 	int		fad_flags;	/* audit control flags */
223 	struct audit_path	*fad_aupath;	/* path from vfs_lookup */
224 };
225 typedef struct f_audit_data f_audit_data_t;
226 
227 #define	FAD_READ	0x0001		/* read system call seen */
228 #define	FAD_WRITE	0x0002		/* write system call seen */
229 
230 #define	P2A(p)	(p->p_audit_data)
231 #define	T2A(t)	(t->t_audit_data)
232 #define	U2A(u)	(curthread->t_audit_data)
233 #define	F2A(f)	(f->f_audit_data)
234 
235 #define	u_ad    ((U2A(u))->tad_ad)
236 #define	ad_ctrl ((U2A(u))->tad_ctrl)
237 #define	ad_flag ((U2A(u))->tad_flag)
238 
239 #define	AU_BUFSIZE	128		/* buffer size for the buffer pool */
240 
241 struct au_buff {
242 	char		buf[AU_BUFSIZE];
243 	struct au_buff	*next_buf;
244 	struct au_buff	*next_rec;
245 	ushort_t	rec_len;
246 	uchar_t		len;
247 	uchar_t		flag;
248 };
249 
250 typedef struct au_buff au_buff_t;
251 
252 /*
253  * Kernel audit queue structure.
254  */
255 struct audit_queue {
256 	au_buff_t *head;	/* head of queue */
257 	au_buff_t *tail;	/* tail of queue */
258 	ssize_t	cnt;		/* number elements on queue */
259 	size_t	hiwater;	/* high water mark to block */
260 	size_t	lowater;	/* low water mark to restart */
261 	size_t	bufsz;		/* audit trail write buffer size */
262 	size_t	buflen;		/* audit trail buffer length in use */
263 	clock_t	delay;		/* delay before flushing queue */
264 	int	wt_block;	/* writer is blocked (1) */
265 	int	rd_block;	/* reader is blocked (1) */
266 	kmutex_t lock;		/* mutex lock for queue modification */
267 	kcondvar_t write_cv;	/* sleep structure for write block */
268 	kcondvar_t read_cv;	/* sleep structure for read block */
269 };
270 
271 
272 union rval;
273 struct audit_s2e {
274 	au_event_t (*au_init)(au_event_t);
275 				/* convert au_event to real audit event ID */
276 
277 	int au_event;		/* default audit event for this system call */
278 	void (*au_start)(struct t_audit_data *);
279 				/* pre-system call audit processing */
280 	void (*au_finish)(struct t_audit_data *, int, union rval *);
281 				/* post-system call audit processing */
282 	int au_ctrl;		/* control flags for auditing actions */
283 };
284 
285 extern struct audit_s2e audit_s2e[];
286 
287 #define	AUK_VALID	0x5A5A5A5A
288 #define	AUK_INVALID	0
289 /*
290  * per zone audit context
291  */
292 struct au_kcontext {
293 	uint32_t		auk_valid;
294 	zoneid_t		auk_zid;
295 
296 	boolean_t		auk_hostaddr_valid;
297 	int			auk_sequence;
298 	int			auk_auditstate;
299 	int			auk_output_active;
300 	struct vnode		*auk_current_vp;
301 	uint32_t		auk_policy;
302 
303 	struct audit_queue	auk_queue;
304 
305 	au_dbuf_t		*auk_dbuffer;	/* auditdoor output */
306 
307 	au_stat_t		auk_statistics;
308 
309 	struct auditinfo_addr	auk_info;
310 	kmutex_t		auk_eagain_mutex; /* door call retry */
311 	kcondvar_t		auk_eagain_cv;
312 
313 	taskq_t			*auk_taskq;	/* output thread */
314 
315 	/* Only one audit svc per zone at a time */
316 	/* With the elimination of auditsvc, can this also go? see 6648414 */
317 	kmutex_t 		auk_svc_lock;
318 
319 	au_state_t		auk_ets[MAX_KEVENTS + 1];
320 };
321 #ifndef AUK_CONTEXT_T
322 #define	AUK_CONTEXT_T
323 typedef struct au_kcontext au_kcontext_t;
324 #endif
325 
326 extern zone_key_t au_zone_key;
327 
328 /*
329  * Kernel auditing external variables
330  */
331 extern uint32_t audit_policy;
332 extern int audit_active;
333 
334 extern struct audit_queue au_queue;
335 extern struct p_audit_data *pad0;
336 extern struct t_audit_data *tad0;
337 
338 /*
339  * audit_path support routines
340  */
341 void au_pathhold(struct audit_path *);
342 void au_pathrele(struct audit_path *);
343 struct audit_path *au_pathdup(const struct audit_path *, int, int);
344 
345 void au_pad_init(void);
346 
347 int auditctl(int cmd, caddr_t data, int length);
348 int auditdoor(int fd);
349 int getauid(caddr_t);
350 int setauid(caddr_t);
351 int getaudit(caddr_t);
352 int getaudit_addr(caddr_t, int);
353 int setaudit(caddr_t);
354 int setaudit_addr(caddr_t, int);
355 
356 /*
357  * Macros to hide asynchronous, non-blocking audit record start and finish
358  * processing.
359  *
360  * NOTE: must be used in (void) funcction () { ... }
361  */
362 
363 #define	AUDIT_ASYNC_START(rp, audit_event, sorf) \
364 { \
365 	label_t jb; \
366 	if (setjmp(&jb)) { \
367 		/* cleanup any residual audit data */ \
368 		audit_async_drop((caddr_t *)&(rp), 0); \
369 		return; \
370 	} \
371 	/* auditing enabled and we're preselected for this event? */ \
372 	if (audit_async_start(&jb, audit_event, sorf)) { \
373 		return; \
374 	} \
375 }
376 
377 #define	AUDIT_ASYNC_FINISH(rp, audit_event, event_modifier, event_time) \
378 	audit_async_finish((caddr_t *)&(rp), audit_event, event_modifier, \
379 	event_time);
380 
381 
382 #ifdef	_KERNEL
383 au_buff_t *au_get_buff(void), *au_free_buff(au_buff_t *);
384 #endif
385 
386 /*
387  * Macro for uniform "subject" token(s) generation
388  */
389 #define	AUDIT_SETSUBJ_GENERIC(u, c, a, k, p)		\
390 	(au_write((u), au_to_subject(crgetuid(c),	\
391 	    crgetgid(c), crgetruid(c), crgetrgid(c),	\
392 	    p, (a)->ai_auid, (a)->ai_asid,		\
393 	    &((a)->ai_termid))));			\
394 	((is_system_labeled()) ?  au_write((u),		\
395 	    au_to_label(CR_SL((c)))) : (void) 0);	\
396 	(((k)->auk_policy & AUDIT_GROUP) ? au_write((u),\
397 	    au_to_groups(crgetgroups(c),		\
398 	    crgetngroups(c))) : (void) 0)
399 
400 #define	AUDIT_SETSUBJ(u, c, a, k)      		\
401 	AUDIT_SETSUBJ_GENERIC(u, c, a, k, curproc->p_pid)
402 
403 #define	AUDIT_SETPROC_GENERIC(u, c, a, p)		\
404 	(au_write((u), au_to_process(crgetuid(c),	\
405 	    crgetgid(c), crgetruid(c), crgetrgid(c),	\
406 	    p, (a)->ai_auid, (a)->ai_asid,		\
407 	    &((a)->ai_termid))));
408 
409 #define	AUDIT_SETPROC(u, c, a)      		\
410 	AUDIT_SETPROC_GENERIC(u, c, a, curproc->p_pid)
411 
412 /*
413  * Macros for type conversion
414  */
415 
416 /* au_membuf head, to typed data */
417 #define	memtod(x, t)	((t)x->buf)
418 
419 /* au_membuf types */
420 #define	MT_FREE		0	/* should be on free list */
421 #define	MT_DATA		1	/* dynamic (data) allocation */
422 
423 /* flags to au_memget */
424 #define	DONTWAIT	0
425 #define	WAIT		1
426 
427 #define	AU_PACK	1	/* pack data in au_append_rec() */
428 #define	AU_LINK 0	/* link data in au_append_rec() */
429 
430 /* flags to async routines */
431 #define	AU_BACKEND	1	/* called from softcall backend */
432 
433 #ifdef __cplusplus
434 }
435 #endif
436 
437 #endif /* _BSM_AUDIT_KERNEL_H */
438