xref: /freebsd/sys/security/audit/audit_private.h (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1999-2009 Apple Inc.
5  * Copyright (c) 2016, 2018 Robert N. M. Watson
6  * All rights reserved.
7  *
8  * Portions of this software were developed by BAE Systems, the University of
9  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
10  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
11  * Computing (TC) research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1.  Redistributions of source code must retain the above copyright
17  *     notice, this list of conditions and the following disclaimer.
18  * 2.  Redistributions in binary form must reproduce the above copyright
19  *     notice, this list of conditions and the following disclaimer in the
20  *     documentation and/or other materials provided with the distribution.
21  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
22  *     its contributors may be used to endorse or promote products derived
23  *     from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR
29  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
34  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * This include file contains function prototypes and type definitions used
40  * within the audit implementation.
41  */
42 
43 #ifndef _SECURITY_AUDIT_PRIVATE_H_
44 #define	_SECURITY_AUDIT_PRIVATE_H_
45 
46 #ifndef _KERNEL
47 #error "no user-serviceable parts inside"
48 #endif
49 
50 #include <sys/caprights.h>
51 #include <sys/ipc.h>
52 #include <sys/socket.h>
53 #include <sys/ucred.h>
54 
55 #ifdef MALLOC_DECLARE
56 MALLOC_DECLARE(M_AUDITBSM);
57 MALLOC_DECLARE(M_AUDITDATA);
58 MALLOC_DECLARE(M_AUDITPATH);
59 MALLOC_DECLARE(M_AUDITTEXT);
60 MALLOC_DECLARE(M_AUDITGIDSET);
61 #endif
62 
63 /*
64  * Audit control variables that are usually set/read via system calls and
65  * used to control various aspects of auditing.
66  */
67 extern struct au_qctrl		audit_qctrl;
68 extern struct audit_fstat	audit_fstat;
69 extern struct au_mask		audit_nae_mask;
70 extern int			audit_panic_on_write_fail;
71 extern int			audit_fail_stop;
72 extern int			audit_argv;
73 extern int			audit_arge;
74 
75 /*
76  * Success/failure conditions for the conversion of a kernel audit record to
77  * BSM format.
78  */
79 #define	BSM_SUCCESS	0
80 #define	BSM_FAILURE	1
81 #define	BSM_NOAUDIT	2
82 
83 /*
84  * Defines for the kernel audit record k_ar_commit field.  Flags are set to
85  * indicate what sort of record it is, and which preselection mechanism
86  * selected it.
87  */
88 #define	AR_COMMIT_KERNEL	0x00000001U
89 #define	AR_COMMIT_USER		0x00000010U
90 
91 #define	AR_PRESELECT_TRAIL	0x00001000U
92 #define	AR_PRESELECT_PIPE	0x00002000U
93 
94 #define	AR_PRESELECT_USER_TRAIL	0x00004000U
95 #define	AR_PRESELECT_USER_PIPE	0x00008000U
96 
97 #define	AR_PRESELECT_DTRACE	0x00010000U
98 
99 /*
100  * Audit data is generated as a stream of struct audit_record structures,
101  * linked by struct kaudit_record, and contain storage for possible audit so
102  * that it will not need to be allocated during the processing of a system
103  * call, both improving efficiency and avoiding sleeping at untimely moments.
104  * This structure is converted to BSM format before being written to disk.
105  */
106 struct vnode_au_info {
107 	mode_t	vn_mode;
108 	uid_t	vn_uid;
109 	gid_t	vn_gid;
110 	u_int32_t vn_dev;		/* XXX dev_t compatibility */
111 	long	vn_fsid;		/* XXX uint64_t compatibility */
112 	long	vn_fileid;		/* XXX ino_t compatibility */
113 	long	vn_gen;
114 };
115 
116 struct groupset {
117 	gid_t	*gidset;
118 	u_int	 gidset_size;
119 };
120 
121 struct socket_au_info {
122 	int		so_domain;
123 	int		so_type;
124 	int		so_protocol;
125 	in_addr_t	so_raddr;	/* Remote address if INET socket. */
126 	in_addr_t	so_laddr;	/* Local address if INET socket. */
127 	u_short		so_rport;	/* Remote port. */
128 	u_short		so_lport;	/* Local port. */
129 };
130 
131 /*
132  * The following is used for A_OLDSETQCTRL and AU_OLDGETQCTRL and a 64-bit
133  * userland.
134  */
135 struct au_qctrl64 {
136 	u_int64_t	aq64_hiwater;
137 	u_int64_t	aq64_lowater;
138 	u_int64_t	aq64_bufsz;
139 	u_int64_t	aq64_delay;
140 	u_int64_t	aq64_minfree;
141 };
142 typedef	struct au_qctrl64	au_qctrl64_t;
143 
144 union auditon_udata {
145 	char			*au_path;
146 	int			au_cond;
147 	int			au_flags;
148 	int			au_policy;
149 	int			au_trigger;
150 	int64_t			au_cond64;
151 	int64_t			au_policy64;
152 	au_evclass_map_t	au_evclass;
153 	au_mask_t		au_mask;
154 	auditinfo_t		au_auinfo;
155 	auditpinfo_t		au_aupinfo;
156 	auditpinfo_addr_t	au_aupinfo_addr;
157 	au_qctrl_t		au_qctrl;
158 	au_qctrl64_t		au_qctrl64;
159 	au_stat_t		au_stat;
160 	au_fstat_t		au_fstat;
161 	auditinfo_addr_t	au_kau_info;
162 	au_evname_map_t		au_evname;
163 };
164 
165 struct posix_ipc_perm {
166 	uid_t	pipc_uid;
167 	gid_t	pipc_gid;
168 	mode_t	pipc_mode;
169 };
170 
171 struct audit_record {
172 	/* Audit record header. */
173 	u_int32_t		ar_magic;
174 	int			ar_event;
175 	int			ar_retval; /* value returned to the process */
176 	int			ar_errno;  /* return status of system call */
177 	struct timespec		ar_starttime;
178 	struct timespec		ar_endtime;
179 	u_int64_t		ar_valid_arg;  /* Bitmask of valid arguments */
180 
181 	/* Audit subject information. */
182 	struct xucred		ar_subj_cred;
183 	uid_t			ar_subj_ruid;
184 	gid_t			ar_subj_rgid;
185 	gid_t			ar_subj_egid;
186 	uid_t			ar_subj_auid; /* Audit user ID */
187 	pid_t			ar_subj_asid; /* Audit session ID */
188 	pid_t			ar_subj_pid;
189 	struct au_tid		ar_subj_term;
190 	struct au_tid_addr	ar_subj_term_addr;
191 	struct au_mask		ar_subj_amask;
192 
193 	/* Operation arguments. */
194 	uid_t			ar_arg_euid;
195 	uid_t			ar_arg_ruid;
196 	uid_t			ar_arg_suid;
197 	gid_t			ar_arg_egid;
198 	gid_t			ar_arg_rgid;
199 	gid_t			ar_arg_sgid;
200 	pid_t			ar_arg_pid;
201 	pid_t			ar_arg_asid;
202 	struct au_tid		ar_arg_termid;
203 	struct au_tid_addr	ar_arg_termid_addr;
204 	uid_t			ar_arg_uid;
205 	uid_t			ar_arg_auid;
206 	gid_t			ar_arg_gid;
207 	struct groupset		ar_arg_groups;
208 	int			ar_arg_fd;
209 	int			ar_arg_atfd1;
210 	int			ar_arg_atfd2;
211 	int			ar_arg_fflags;
212 	mode_t			ar_arg_mode;
213 	int			ar_arg_dev;	/* XXX dev_t compatibility */
214 	long			ar_arg_value;
215 	void			*ar_arg_addr;
216 	int			ar_arg_len;
217 	int			ar_arg_mask;
218 	u_int			ar_arg_signum;
219 	char			ar_arg_login[MAXLOGNAME];
220 	int			ar_arg_ctlname[CTL_MAXNAME];
221 	struct socket_au_info	ar_arg_sockinfo;
222 	char			*ar_arg_upath1;
223 	char			*ar_arg_upath2;
224 	char			*ar_arg_text;
225 	struct au_mask		ar_arg_amask;
226 	struct vnode_au_info	ar_arg_vnode1;
227 	struct vnode_au_info	ar_arg_vnode2;
228 	int			ar_arg_cmd;
229 	int			ar_arg_svipc_which;
230 	int			ar_arg_svipc_cmd;
231 	struct ipc_perm		ar_arg_svipc_perm;
232 	int			ar_arg_svipc_id;
233 	void			*ar_arg_svipc_addr;
234 	struct posix_ipc_perm	ar_arg_pipc_perm;
235 	union auditon_udata	ar_arg_auditon;
236 	char			*ar_arg_argv;
237 	int			ar_arg_argc;
238 	char			*ar_arg_envv;
239 	int			ar_arg_envc;
240 	int			ar_arg_exitstatus;
241 	int			ar_arg_exitretval;
242 	struct sockaddr_storage ar_arg_sockaddr;
243 	cap_rights_t		ar_arg_rights;
244 	uint32_t		ar_arg_fcntl_rights;
245 	char			ar_jailname[MAXHOSTNAMELEN];
246 };
247 
248 /*
249  * Arguments in the audit record are initially not defined; flags are set to
250  * indicate if they are present so they can be included in the audit log
251  * stream only if defined.
252  */
253 #define	ARG_EUID		0x0000000000000001ULL
254 #define	ARG_RUID		0x0000000000000002ULL
255 #define	ARG_SUID		0x0000000000000004ULL
256 #define	ARG_EGID		0x0000000000000008ULL
257 #define	ARG_RGID		0x0000000000000010ULL
258 #define	ARG_SGID		0x0000000000000020ULL
259 #define	ARG_PID			0x0000000000000040ULL
260 #define	ARG_UID			0x0000000000000080ULL
261 #define	ARG_AUID		0x0000000000000100ULL
262 #define	ARG_GID			0x0000000000000200ULL
263 #define	ARG_FD			0x0000000000000400ULL
264 #define	ARG_POSIX_IPC_PERM	0x0000000000000800ULL
265 #define	ARG_FFLAGS		0x0000000000001000ULL
266 #define	ARG_MODE		0x0000000000002000ULL
267 #define	ARG_DEV			0x0000000000004000ULL
268 #define	ARG_ADDR		0x0000000000008000ULL
269 #define	ARG_LEN			0x0000000000010000ULL
270 #define	ARG_MASK		0x0000000000020000ULL
271 #define	ARG_SIGNUM		0x0000000000040000ULL
272 #define	ARG_LOGIN		0x0000000000080000ULL
273 #define	ARG_SADDRINET		0x0000000000100000ULL
274 #define	ARG_SADDRINET6		0x0000000000200000ULL
275 #define	ARG_SADDRUNIX		0x0000000000400000ULL
276 #define	ARG_TERMID_ADDR		0x0000000000800000ULL
277 #define	ARG_UNUSED2		0x0000000001000000ULL
278 #define	ARG_UPATH1		0x0000000002000000ULL
279 #define	ARG_UPATH2		0x0000000004000000ULL
280 #define	ARG_TEXT		0x0000000008000000ULL
281 #define	ARG_VNODE1		0x0000000010000000ULL
282 #define	ARG_VNODE2		0x0000000020000000ULL
283 #define	ARG_SVIPC_CMD		0x0000000040000000ULL
284 #define	ARG_SVIPC_PERM		0x0000000080000000ULL
285 #define	ARG_SVIPC_ID		0x0000000100000000ULL
286 #define	ARG_SVIPC_ADDR		0x0000000200000000ULL
287 #define	ARG_GROUPSET		0x0000000400000000ULL
288 #define	ARG_CMD			0x0000000800000000ULL
289 #define	ARG_SOCKINFO		0x0000001000000000ULL
290 #define	ARG_ASID		0x0000002000000000ULL
291 #define	ARG_TERMID		0x0000004000000000ULL
292 #define	ARG_AUDITON		0x0000008000000000ULL
293 #define	ARG_VALUE		0x0000010000000000ULL
294 #define	ARG_AMASK		0x0000020000000000ULL
295 #define	ARG_CTLNAME		0x0000040000000000ULL
296 #define	ARG_PROCESS		0x0000080000000000ULL
297 #define	ARG_MACHPORT1		0x0000100000000000ULL
298 #define	ARG_MACHPORT2		0x0000200000000000ULL
299 #define	ARG_EXIT		0x0000400000000000ULL
300 #define	ARG_IOVECSTR		0x0000800000000000ULL
301 #define	ARG_ARGV		0x0001000000000000ULL
302 #define	ARG_ENVV		0x0002000000000000ULL
303 #define	ARG_ATFD1		0x0004000000000000ULL
304 #define	ARG_ATFD2		0x0008000000000000ULL
305 #define	ARG_RIGHTS		0x0010000000000000ULL
306 #define	ARG_FCNTL_RIGHTS	0x0020000000000000ULL
307 #define	ARG_SVIPC_WHICH		0x0200000000000000ULL
308 #define	ARG_NONE		0x0000000000000000ULL
309 #define	ARG_ALL			0xFFFFFFFFFFFFFFFFULL
310 
311 #define	ARG_IS_VALID(kar, arg)	((kar)->k_ar.ar_valid_arg & (arg))
312 #define	ARG_SET_VALID(kar, arg) do {					\
313 	(kar)->k_ar.ar_valid_arg |= (arg);				\
314 } while (0)
315 #define	ARG_CLEAR_VALID(kar, arg) do {					\
316 	(kar)->k_ar.ar_valid_arg &= ~(arg);				\
317 } while (0)
318 
319 /*
320  * In-kernel version of audit record; the basic record plus queue meta-data.
321  * This record can also have a pointer set to some opaque data that will be
322  * passed through to the audit writing mechanism.
323  */
324 struct kaudit_record {
325 	struct audit_record		 k_ar;
326 	u_int32_t			 k_ar_commit;
327 	void				*k_udata;	/* User data. */
328 	u_int				 k_ulen;	/* User data length. */
329 	struct uthread			*k_uthread;	/* Audited thread. */
330 	void				*k_dtaudit_state;
331 	TAILQ_ENTRY(kaudit_record)	 k_q;
332 };
333 TAILQ_HEAD(kaudit_queue, kaudit_record);
334 
335 /*
336  * Functions to manage the allocation, release, and commit of kernel audit
337  * records.
338  */
339 void			 audit_abort(struct kaudit_record *ar);
340 void			 audit_commit(struct kaudit_record *ar, int error,
341 			    int retval);
342 struct kaudit_record	*audit_new(int event, struct thread *td);
343 
344 /*
345  * Function to update the audit_syscalls_enabled flag, whose value is affected
346  * by configuration of the audit trail/pipe mechanism and DTrace.  Call this
347  * function when any of the inputs to that policy change.
348  */
349 void	audit_syscalls_enabled_update(void);
350 
351 /*
352  * Functions relating to the conversion of internal kernel audit records to
353  * the BSM file format.
354  */
355 struct au_record;
356 int	 kaudit_to_bsm(struct kaudit_record *kar, struct au_record **pau);
357 int	 bsm_rec_verify(void *rec);
358 
359 /*
360  * Kernel versions of the libbsm audit record functions.
361  */
362 void	 kau_free(struct au_record *rec);
363 void	 kau_init(void);
364 
365 /*
366  * Return values for pre-selection and post-selection decisions.
367  */
368 #define	AU_PRS_SUCCESS	1
369 #define	AU_PRS_FAILURE	2
370 #define	AU_PRS_BOTH	(AU_PRS_SUCCESS|AU_PRS_FAILURE)
371 
372 /*
373  * Data structures relating to the kernel audit queue.  Ideally, these might
374  * be abstracted so that only accessor methods are exposed.
375  */
376 extern struct mtx		audit_mtx;
377 extern struct cv		audit_watermark_cv;
378 extern struct cv		audit_worker_cv;
379 extern struct kaudit_queue	audit_q;
380 extern int			audit_q_len;
381 extern int			audit_pre_q_len;
382 extern int			audit_in_failure;
383 
384 /*
385  * Flags to use on audit files when opening and closing.
386  */
387 #define	AUDIT_OPEN_FLAGS	(FWRITE | O_APPEND)
388 #define	AUDIT_CLOSE_FLAGS	(FWRITE | O_APPEND)
389 
390 /*
391  * Audit event-to-name mapping structure, maintained in audit_bsm_klib.c.  It
392  * appears in this header so that the DTrace audit provider can dereference
393  * instances passed back in the au_evname_foreach() callbacks.  Safe access to
394  * its fields requires holding ene_lock (after it is visible in the global
395  * table).
396  *
397  * Locking:
398  * (c) - Constant after inserted in the global table
399  * (l) - Protected by ene_lock
400  * (m) - Protected by evnamemap_lock (audit_bsm_klib.c)
401  * (M) - Writes protected by evnamemap_lock; reads unprotected.
402  */
403 struct evname_elem {
404 	au_event_t		ene_event;			/* (c) */
405 	char			ene_name[EVNAMEMAP_NAME_SIZE];	/* (l) */
406 	LIST_ENTRY(evname_elem)	ene_entry;			/* (m) */
407 	struct mtx		ene_lock;
408 
409 	/* DTrace probe IDs; 0 if not yet registered. */
410 	uint32_t		ene_commit_probe_id;		/* (M) */
411 	uint32_t		ene_bsm_probe_id;		/* (M) */
412 
413 	/* Flags indicating if the probes enabled or not. */
414 	int			ene_commit_probe_enabled;	/* (M) */
415 	int			ene_bsm_probe_enabled;		/* (M) */
416 };
417 
418 #define	EVNAME_LOCK(ene)	mtx_lock(&(ene)->ene_lock)
419 #define	EVNAME_UNLOCK(ene)	mtx_unlock(&(ene)->ene_lock)
420 
421 /*
422  * Callback function typedef for the same.
423  */
424 typedef	void	(*au_evnamemap_callback_t)(struct evname_elem *ene);
425 
426 /*
427  * DTrace audit provider (dtaudit) hooks -- to be set non-NULL when the audit
428  * provider is loaded and ready to be called into.
429  */
430 extern void	*(*dtaudit_hook_preselect)(au_id_t auid, au_event_t event,
431 		    au_class_t class);
432 extern int	(*dtaudit_hook_commit)(struct kaudit_record *kar,
433 		    au_id_t auid, au_event_t event, au_class_t class,
434 		    int sorf);
435 extern void	(*dtaudit_hook_bsm)(struct kaudit_record *kar, au_id_t auid,
436 		    au_event_t event, au_class_t class, int sorf,
437 		    void *bsm_data, size_t bsm_len);
438 
439 #include <sys/fcntl.h>
440 #include <sys/kernel.h>
441 #include <sys/malloc.h>
442 
443 /*
444  * Some of the BSM tokenizer functions take different parameters in the
445  * kernel implementations in order to save the copying of large kernel data
446  * structures.  The prototypes of these functions are declared here.
447  */
448 token_t		*kau_to_socket(struct socket_au_info *soi);
449 
450 /*
451  * audit_klib prototypes
452  */
453 int		 au_preselect(au_event_t event, au_class_t class,
454 		    au_mask_t *mask_p, int sorf);
455 void		 au_evclassmap_init(void);
456 void		 au_evclassmap_insert(au_event_t event, au_class_t class);
457 au_class_t	 au_event_class(au_event_t event);
458 void		 au_evnamemap_init(void);
459 void		 au_evnamemap_insert(au_event_t event, const char *name);
460 void		 au_evnamemap_foreach(au_evnamemap_callback_t callback);
461 struct evname_elem	*au_evnamemap_lookup(au_event_t event);
462 int		 au_event_name(au_event_t event, char *name);
463 au_event_t	 audit_ctlname_to_sysctlevent(int name[], uint64_t valid_arg);
464 au_event_t	 audit_flags_and_error_to_openevent(int oflags, int error);
465 au_event_t	 audit_flags_and_error_to_openatevent(int oflags, int error);
466 au_event_t	 audit_msgctl_to_event(int cmd);
467 au_event_t	 audit_msgsys_to_event(int which);
468 au_event_t	 audit_semctl_to_event(int cmd);
469 au_event_t	 audit_semsys_to_event(int which);
470 au_event_t	 audit_shmsys_to_event(int which);
471 void		 audit_canon_path(struct thread *td, int dirfd, char *path,
472 		    char *cpath);
473 void		 audit_canon_path_vp(struct thread *td, struct vnode *rdir,
474 		    struct vnode *cdir, char *path, char *cpath);
475 au_event_t	 auditon_command_event(int cmd);
476 
477 /*
478  * Audit trigger events notify user space of kernel audit conditions
479  * asynchronously.
480  */
481 void		 audit_trigger_init(void);
482 int		 audit_send_trigger(unsigned int trigger);
483 
484 /*
485  * Accessor functions to manage global audit state.
486  */
487 void	 audit_set_kinfo(struct auditinfo_addr *);
488 void	 audit_get_kinfo(struct auditinfo_addr *);
489 
490 /*
491  * General audit related functions.
492  */
493 struct kaudit_record	*currecord(void);
494 void			 audit_free(struct kaudit_record *ar);
495 void			 audit_shutdown(void *arg, int howto);
496 void			 audit_rotate_vnode(struct ucred *cred,
497 			    struct vnode *vp);
498 void			 audit_worker_init(void);
499 
500 /*
501  * Audit pipe functions.
502  */
503 int	 audit_pipe_preselect(au_id_t auid, au_event_t event,
504 	    au_class_t class, int sorf, int trail_select);
505 void	 audit_pipe_submit(au_id_t auid, au_event_t event, au_class_t class,
506 	    int sorf, int trail_select, void *record, u_int record_len);
507 void	 audit_pipe_submit_user(void *record, u_int record_len);
508 
509 #endif /* ! _SECURITY_AUDIT_PRIVATE_H_ */
510