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 * Copyright 2018 Nexenta Systems, Inc. All rights reserved.
24 */
25
26 #ifndef _BSM_AUDIT_KERNEL_H
27 #define _BSM_AUDIT_KERNEL_H
28
29
30 /*
31 * This file contains the basic auditing control structure definitions.
32 */
33
34 #include <c2/audit.h>
35 #include <c2/audit_kevents.h>
36 #include <sys/priv_impl.h>
37 #include <sys/taskq.h>
38 #include <sys/zone.h>
39
40 #include <sys/tsol/label.h>
41
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45
46 /*
47 * This table contains the mapping from the system call ID to a corresponding
48 * audit event.
49 *
50 * au_init() is a function called at the beginning of the system call that
51 * performs any necessary setup/processing. It maps the call into the
52 * appropriate event, depending on the system call arguments. It is called
53 * by audit_start() from trap.c .
54 *
55 * au_event is the audit event associated with the system call. Most of the
56 * time it will map directly from the system call i.e. There is one system
57 * call associated with the event. In some cases, such as shmsys, or open,
58 * the au_start() function will map the system call to more than one event,
59 * depending on the system call arguments.
60 *
61 * au_start() is a function that provides per system call processing at the
62 * beginning of a system call. It is mainly concerned with preseving the
63 * audit record components that may be altered so that we can determine
64 * what the original paramater was before as well as after the system call.
65 * It is possible that au_start() may be taken away. It might be cleaner to
66 * define flags in au_ctrl to save a designated argument. For the moment we
67 * support both mechanisms, however the use of au_start() will be reviewed
68 * for 4.1.1 and CMW and ZEUS to see if such a general method is justified.
69 *
70 * au_finish() is a function that provides per system call processing at the
71 * completion of a system call. In certain circumstances, the type of audit
72 * event depends on intermidiate results during the processing of the system
73 * call. It is called in audit_finish() from trap.c .
74 *
75 * au_ctrl is a control vector that indicates what processing might have to
76 * be performed, even if there is no auditing for this system call. At
77 * present this is mostly for path processing for chmod, chroot. We need to
78 * process the path information in vfs_lookup, even when we are not auditing
79 * the system call in the case of chdir and chroot.
80 */
81 /*
82 * Defines for au_ctrl
83 */
84 #define S2E_SP TAD_SAVPATH /* save path for later use */
85 #define S2E_MLD TAD_MLD /* only one lookup per system call */
86 #define S2E_NPT TAD_NOPATH /* force no path in audit record */
87 #define S2E_PUB TAD_PUBLIC_EV /* syscall is defined as a public op */
88
89 /*
90 * At present, we are using the audit classes imbedded with in the kernel. Each
91 * event has a bit mask determining which classes the event is associated.
92 * The table audit_e2s maps the audit event ID to the audit state.
93 *
94 * Note that this may change radically. If we use a bit vector for the audit
95 * class, we can allow granularity at the event ID for each user. In this
96 * case, the vector would be determined at user level and passed to the kernel
97 * via the setaudit system call.
98 */
99
100 /*
101 * The audit_pad structure holds paths for the current root and directory
102 * for the process, as well as for open files and directly manipulated objects.
103 * The reference count minimizes data copies since the process's current
104 * directory changes very seldom.
105 */
106 struct audit_path {
107 uint_t audp_ref; /* reference count */
108 uint_t audp_size; /* allocated size of this structure */
109 uint_t audp_cnt; /* number of path sections */
110 char *audp_sect[1]; /* path section pointers */
111 /* audp_sect[0] is the path name */
112 /* audp_sect[1+] are attribute paths */
113 };
114
115 /*
116 * The structure of the terminal ID within the kernel is different from the
117 * terminal ID in user space. It is a combination of port and IP address.
118 */
119
120 struct au_termid {
121 dev_t at_port;
122 uint_t at_type;
123 uint_t at_addr[4];
124 };
125 typedef struct au_termid au_termid_t;
126
127 /*
128 * Attributes for deferring the queuing of an event.
129 */
130 typedef struct au_defer_info {
131 struct au_defer_info *audi_next; /* next on linked list */
132 void *audi_ad; /* audit record */
133 au_event_t audi_e_type; /* audit event id */
134 au_emod_t audi_e_mod; /* audit event modifier */
135 int audi_flag; /* au_close*() flags */
136 timestruc_t audi_atime; /* audit event timestamp */
137 } au_defer_info_t;
138
139 /*
140 * The structure p_audit_data hangs off of the process structure. It contains
141 * all of the audit information necessary to manage the audit record generation
142 * for each process.
143 *
144 * The pad_lock is constructed in the kmem_cache; the rest is combined
145 * in a sub structure so it can be copied/zeroed in one statement.
146 *
147 * The members have been reordered for maximum packing on 64 bit Solaris.
148 */
149 struct p_audit_data {
150 kmutex_t pad_lock; /* lock pad data during changes */
151 struct _pad_data {
152 struct audit_path *pad_root; /* process root path */
153 struct audit_path *pad_cwd; /* process cwd path */
154 au_mask_t pad_newmask; /* pending new mask */
155 int pad_flags;
156 } pad_data;
157 };
158 typedef struct p_audit_data p_audit_data_t;
159
160 #define pad_root pad_data.pad_root
161 #define pad_cwd pad_data.pad_cwd
162 #define pad_newmask pad_data.pad_newmask
163 #define pad_flags pad_data.pad_flags
164
165 /*
166 * Defines for process audit flags (pad_flags)
167 */
168 #define PAD_SETMASK 0x00000001 /* need to complete pending setmask */
169
170 extern kmem_cache_t *au_pad_cache;
171
172 /*
173 * Defines for thread audit control/status flags (tad_ctrl)
174 */
175 #define TAD_ABSPATH 0x00000001 /* path from lookup is absolute */
176 #define TAD_ATCALL 0x00000002 /* *at() syscall, like openat() */
177 #define TAD_ATTPATH 0x00000004 /* attribute file lookup */
178 #define TAD_CORE 0x00000008 /* save attribute during core dump */
179 #define TAD_ERRJMP 0x00000010 /* abort record generation on error */
180 #define TAD_MLD 0x00000020 /* system call involves MLD */
181 #define TAD_NOATTRB 0x00000040 /* do not automatically add attribute */
182 #define TAD_NOAUDIT 0x00000080 /* discard audit record */
183 #define TAD_NOPATH 0x00000100 /* force no paths in audit record */
184 #define TAD_PATHFND 0x00000200 /* found path, don't retry lookup */
185 #define TAD_PUBLIC_EV 0x00000400 /* syscall is defined as a public op */
186 #define TAD_SAVPATH 0x00000800 /* save path for further processing */
187 #define TAD_TRUE_CREATE 0x00001000 /* true create, file not found */
188
189 /*
190 * These types implement the interface between a consumer and FS for handling
191 * SACL-based File Access Auditing. A consumer zeroes out the appropriate
192 * t_audit_sacl_t in T2A(curthread), then sets tad_sacl_ctrl to one of
193 * sacl_audit_ctrl_t. The FS, when auditing of SACLs is enabled, checks to see
194 * if tad_sacl_ctrl is not NONE. If so, it collects information from the
195 * object's SACL (such as NFSv4 Audit and Alarm type ACEs), and stores
196 * representative Success and Failure masks in the t_audit_sacl_t structure.
197 * The consumer then compares the requested access to the appropriate mask in
198 * order to determine whether an audit record should be generated.
199 */
200 typedef struct t_audit_sacl {
201 uint32_t tas_smask;
202 uint32_t tas_fmask;
203 } t_audit_sacl_t;
204
205 typedef enum sacl_audit_ctrl {
206 SACL_AUDIT_NONE = 0,
207 SACL_AUDIT_ON,
208 SACL_AUDIT_ALL,
209 SACL_AUDIT_NO_SRC
210 } sacl_audit_ctrl_t;
211
212 /*
213 * The structure t_audit_data hangs off of the thread structure. It contains
214 * all of the audit information necessary to manage the audit record generation
215 * for each thread.
216 *
217 */
218
219 struct t_audit_data {
220 kthread_id_t tad_thread; /* DEBUG pointer to parent thread */
221 unsigned int tad_scid; /* system call ID for finish */
222 au_event_t tad_event; /* event for audit record */
223 au_emod_t tad_evmod; /* event modifier for audit record */
224 int tad_ctrl; /* audit control/status flags */
225 void *tad_errjmp; /* error longjmp (audit record aborted) */
226 int tad_flag; /* to audit or not to audit */
227 uint32_t tad_audit; /* auditing enabled/disabled */
228 struct audit_path *tad_aupath; /* captured at vfs_lookup */
229 struct audit_path *tad_atpath; /* openat prefix, path of fd */
230 caddr_t tad_ad; /* base of accumulated audit data */
231 au_defer_info_t *tad_defer_head; /* queue of records to defer */
232 /* until syscall end: */
233 au_defer_info_t *tad_defer_tail; /* tail of defer queue */
234 priv_set_t tad_sprivs; /* saved (success) used privs */
235 priv_set_t tad_fprivs; /* saved (failed) used privs */
236 sacl_audit_ctrl_t tad_sacl_ctrl;
237 sacl_audit_ctrl_t tad_sacl_backup;
238 t_audit_sacl_t tad_sacl_mask;
239 t_audit_sacl_t tad_sacl_mask_src;
240 t_audit_sacl_t tad_sacl_mask_dest;
241 };
242 typedef struct t_audit_data t_audit_data_t;
243
244 /*
245 * The f_audit_data structure hangs off of the file structure. It contains
246 * three fields of data. The audit ID, the audit state, and a path name.
247 */
248
249 struct f_audit_data {
250 kthread_id_t fad_thread; /* DEBUG creating thread */
251 int fad_flags; /* audit control flags */
252 struct audit_path *fad_aupath; /* path from vfs_lookup */
253 };
254 typedef struct f_audit_data f_audit_data_t;
255
256 #define FAD_READ 0x0001 /* read system call seen */
257 #define FAD_WRITE 0x0002 /* write system call seen */
258
259 #define P2A(p) (p->p_audit_data)
260 #define T2A(t) (t->t_audit_data)
261 #define U2A(u) (curthread->t_audit_data)
262 #define F2A(f) (f->f_audit_data)
263
264 #define u_ad ((U2A(u))->tad_ad)
265 #define ad_ctrl ((U2A(u))->tad_ctrl)
266 #define ad_flag ((U2A(u))->tad_flag)
267
268 #define AU_BUFSIZE 128 /* buffer size for the buffer pool */
269
270 struct au_buff {
271 char buf[AU_BUFSIZE];
272 struct au_buff *next_buf;
273 struct au_buff *next_rec;
274 ushort_t rec_len;
275 uchar_t len;
276 uchar_t flag;
277 };
278
279 typedef struct au_buff au_buff_t;
280
281 /*
282 * Kernel audit queue structure.
283 */
284 struct audit_queue {
285 au_buff_t *head; /* head of queue */
286 au_buff_t *tail; /* tail of queue */
287 ssize_t cnt; /* number elements on queue */
288 size_t hiwater; /* high water mark to block */
289 size_t lowater; /* low water mark to restart */
290 size_t bufsz; /* audit trail write buffer size */
291 size_t buflen; /* audit trail buffer length in use */
292 clock_t delay; /* delay before flushing queue */
293 int wt_block; /* writer is blocked (1) */
294 int rd_block; /* reader is blocked (1) */
295 kmutex_t lock; /* mutex lock for queue modification */
296 kcondvar_t write_cv; /* sleep structure for write block */
297 kcondvar_t read_cv; /* sleep structure for read block */
298 };
299
300
301 union rval;
302 struct audit_s2e {
303 au_event_t (*au_init)(au_event_t);
304 /* convert au_event to real audit event ID */
305
306 int au_event; /* default audit event for this system call */
307 void (*au_start)(struct t_audit_data *);
308 /* pre-system call audit processing */
309 void (*au_finish)(struct t_audit_data *, int, union rval *);
310 /* post-system call audit processing */
311 int au_ctrl; /* control flags for auditing actions */
312 };
313
314 extern struct audit_s2e audit_s2e[];
315
316 #define AUK_VALID 0x5A5A5A5A
317 #define AUK_INVALID 0
318 /*
319 * per zone audit context
320 */
321 struct au_kcontext {
322 uint32_t auk_valid;
323 zoneid_t auk_zid;
324
325 boolean_t auk_hostaddr_valid;
326 int auk_sequence;
327 int auk_auditstate;
328 int auk_output_active;
329 struct vnode *auk_current_vp;
330 uint32_t auk_policy;
331
332 struct audit_queue auk_queue;
333
334 au_dbuf_t *auk_dbuffer; /* auditdoor output */
335
336 au_stat_t auk_statistics;
337
338 k_auditinfo_addr_t auk_info;
339 kmutex_t auk_eagain_mutex; /* door call retry */
340 kcondvar_t auk_eagain_cv;
341
342 taskq_t *auk_taskq; /* output thread */
343
344 /* Only one audit svc per zone at a time */
345 /* With the elimination of auditsvc, can this also go? see 6648414 */
346 kmutex_t auk_svc_lock;
347
348 au_state_t auk_ets[MAX_KEVENTS + 1];
349 };
350 #ifndef AUK_CONTEXT_T
351 #define AUK_CONTEXT_T
352 typedef struct au_kcontext au_kcontext_t;
353 #endif
354
355 extern zone_key_t au_zone_key;
356
357 /*
358 * Kernel auditing external variables
359 */
360 extern uint32_t audit_policy;
361 extern int audit_active;
362
363 extern struct audit_queue au_queue;
364 extern struct p_audit_data *pad0;
365 extern struct t_audit_data *tad0;
366
367 /*
368 * audit_path support routines
369 */
370 void au_pathhold(struct audit_path *);
371 void au_pathrele(struct audit_path *);
372 struct audit_path *au_pathdup(const struct audit_path *, int, int);
373
374 void au_pad_init(void);
375
376 int auditctl(int cmd, caddr_t data, int length);
377 int auditdoor(int fd);
378 int getauid(caddr_t);
379 int setauid(caddr_t);
380 int getaudit(caddr_t);
381 int getaudit_addr(caddr_t, int);
382 int setaudit(caddr_t);
383 int setaudit_addr(caddr_t, int);
384
385 /*
386 * Macros to hide asynchronous, non-blocking audit record start and finish
387 * processing.
388 *
389 * NOTE: must be used in (void) funcction () { ... }
390 */
391
392 #define AUDIT_ASYNC_START(rp, audit_event, sorf) \
393 { \
394 label_t jb; \
395 if (setjmp(&jb)) { \
396 /* cleanup any residual audit data */ \
397 audit_async_drop((caddr_t *)&(rp), 0); \
398 return; \
399 } \
400 /* auditing enabled and we're preselected for this event? */ \
401 if (audit_async_start(&jb, audit_event, sorf)) { \
402 return; \
403 } \
404 }
405
406 #define AUDIT_ASYNC_FINISH(rp, audit_event, event_modifier, event_time) \
407 audit_async_finish((caddr_t *)&(rp), audit_event, event_modifier, \
408 event_time);
409
410
411 #ifdef _KERNEL
412 au_buff_t *au_get_buff(void), *au_free_buff(au_buff_t *);
413 #endif
414
415 /*
416 * Macro for uniform "subject" token(s) generation
417 */
418 #define AUDIT_SETSUBJ_GENERIC(u, c, a, k, p) \
419 (au_write((u), au_to_subject(crgetuid(c), \
420 crgetgid(c), crgetruid(c), crgetrgid(c), \
421 p, (a)->ai_auid, (a)->ai_asid, \
422 &((a)->ai_termid)))); \
423 ((is_system_labeled()) ? au_write((u), \
424 au_to_label(CR_SL((c)))) : (void) 0); \
425 (((k)->auk_policy & AUDIT_GROUP) ? au_write((u),\
426 au_to_groups(crgetgroups(c), \
427 crgetngroups(c))) : (void) 0)
428
429 #define AUDIT_SETSUBJ(u, c, a, k) \
430 AUDIT_SETSUBJ_GENERIC(u, c, a, k, curproc->p_pid)
431
432 #define AUDIT_SETPROC_GENERIC(u, c, a, p) \
433 (au_write((u), au_to_process(crgetuid(c), \
434 crgetgid(c), crgetruid(c), crgetrgid(c), \
435 p, (a)->ai_auid, (a)->ai_asid, \
436 &((a)->ai_termid))));
437
438 #define AUDIT_SETPROC(u, c, a) \
439 AUDIT_SETPROC_GENERIC(u, c, a, curproc->p_pid)
440
441 /*
442 * Macros for type conversion
443 */
444
445 /* au_membuf head, to typed data */
446 #define memtod(x, t) ((t)x->buf)
447
448 /* au_membuf types */
449 #define MT_FREE 0 /* should be on free list */
450 #define MT_DATA 1 /* dynamic (data) allocation */
451
452 /* flags to au_memget */
453 #define DONTWAIT 0
454 #define WAIT 1
455
456 #define AU_PACK 1 /* pack data in au_append_rec() */
457 #define AU_LINK 0 /* link data in au_append_rec() */
458
459 /* flags to async routines */
460 #define AU_BACKEND 1 /* called from softcall backend */
461
462 #ifdef __cplusplus
463 }
464 #endif
465
466 #endif /* _BSM_AUDIT_KERNEL_H */