xref: /netbsd-src/sys/kern/kern_veriexec.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: kern_veriexec.c,v 1.18 2017/11/07 18:35:57 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2005, 2006 Elad Efrat <elad@NetBSD.org>
5  * Copyright (c) 2005, 2006 Brett Lymn <blymn@NetBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the authors may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: kern_veriexec.c,v 1.18 2017/11/07 18:35:57 christos Exp $");
33 
34 #include "opt_veriexec.h"
35 
36 #include <sys/param.h>
37 #include <sys/mount.h>
38 #include <sys/kmem.h>
39 #include <sys/vnode.h>
40 #include <sys/namei.h>
41 #include <sys/once.h>
42 #include <sys/proc.h>
43 #include <sys/rwlock.h>
44 #include <sys/syslog.h>
45 #include <sys/sysctl.h>
46 #include <sys/inttypes.h>
47 #include <sys/verified_exec.h>
48 #include <sys/sha1.h>
49 #include <sys/sha2.h>
50 #include <sys/rmd160.h>
51 #include <sys/md5.h>
52 #include <sys/fileassoc.h>
53 #include <sys/kauth.h>
54 #include <sys/conf.h>
55 #include <miscfs/specfs/specdev.h>
56 #include <prop/proplib.h>
57 #include <sys/fcntl.h>
58 
59 /* Readable values for veriexec_file_report(). */
60 #define	REPORT_ALWAYS		0x01	/* Always print */
61 #define	REPORT_VERBOSE		0x02	/* Print when verbose >= 1 */
62 #define	REPORT_DEBUG		0x04	/* Print when verbose >= 2 (debug) */
63 #define	REPORT_PANIC		0x08	/* Call panic() */
64 #define	REPORT_ALARM		0x10	/* Alarm - also print pid/uid/.. */
65 #define	REPORT_LOGMASK		(REPORT_ALWAYS|REPORT_VERBOSE|REPORT_DEBUG)
66 
67 /* state of locking for veriexec_file_verify */
68 #define VERIEXEC_UNLOCKED	0x00	/* Nothing locked, callee does it */
69 #define VERIEXEC_LOCKED		0x01	/* Global op lock held */
70 
71 /* state of file locking for veriexec_file_verify */
72 #define VERIEXEC_FILE_UNLOCKED	0x02	/* Nothing locked, callee does it */
73 #define VERIEXEC_FILE_LOCKED	0x04	/* File locked */
74 
75 #define VERIEXEC_RW_UPGRADE(lock)	while((rw_tryupgrade(lock)) == 0){};
76 
77 struct veriexec_fpops {
78 	const char *type;
79 	size_t hash_len;
80 	size_t context_size;
81 	veriexec_fpop_init_t init;
82 	veriexec_fpop_update_t update;
83 	veriexec_fpop_final_t final;
84 	LIST_ENTRY(veriexec_fpops) entries;
85 };
86 
87 /* Veriexec per-file entry data. */
88 struct veriexec_file_entry {
89 	krwlock_t lock;				/* r/w lock */
90 	u_char *filename;			/* File name. */
91 	u_char type;				/* Entry type. */
92 	u_char status;				/* Evaluation status. */
93 	u_char *fp;				/* Fingerprint. */
94 	struct veriexec_fpops *ops;		/* Fingerprint ops vector*/
95 	size_t filename_len;			/* Length of filename. */
96 };
97 
98 /* Veriexec per-table data. */
99 struct veriexec_table_entry {
100 	uint64_t vte_count;			/* Number of Veriexec entries. */
101 	const struct sysctlnode *vte_node;
102 };
103 
104 static int veriexec_verbose;
105 static int veriexec_strict;
106 static int veriexec_bypass = 1;
107 
108 static char *veriexec_fp_names = NULL;
109 static size_t veriexec_name_max = 0;
110 
111 static const struct sysctlnode *veriexec_count_node;
112 
113 static fileassoc_t veriexec_hook;
114 static specificdata_key_t veriexec_mountspecific_key;
115 
116 static LIST_HEAD(, veriexec_fpops) veriexec_fpops_list =
117 	LIST_HEAD_INITIALIZER(veriexec_fpops_list);
118 
119 static int veriexec_raw_cb(kauth_cred_t, kauth_action_t, void *,
120     void *, void *, void *, void *);
121 static struct veriexec_fpops *veriexec_fpops_lookup(const char *);
122 static void veriexec_file_free(struct veriexec_file_entry *);
123 
124 static unsigned int veriexec_tablecount = 0;
125 
126 /*
127  * Veriexec operations global lock - most ops hold this as a read
128  * lock, it is upgraded to a write lock when destroying veriexec file
129  * table entries.
130  */
131 static krwlock_t veriexec_op_lock;
132 
133 /*
134  * Sysctl helper routine for Veriexec.
135  */
136 static int
137 sysctl_kern_veriexec_algorithms(SYSCTLFN_ARGS)
138 {
139 	size_t len;
140 	int error;
141 	const char *p;
142 
143 	if (newp != NULL)
144 		return EPERM;
145 
146 	if (namelen != 0)
147 		return EINVAL;
148 
149 	p = veriexec_fp_names == NULL ? "" : veriexec_fp_names;
150 
151 	len = strlen(p) + 1;
152 
153 	if (*oldlenp < len && oldp)
154 		return ENOMEM;
155 
156 	if (oldp && (error = copyout(p, oldp, len)) != 0)
157 		return error;
158 
159 	*oldlenp = len;
160 	return 0;
161 }
162 
163 static int
164 sysctl_kern_veriexec_strict(SYSCTLFN_ARGS)
165 {
166 	struct sysctlnode node;
167 	int error, newval;
168 
169 	node = *rnode;
170 	node.sysctl_data = &newval;
171 
172 	newval = veriexec_strict;
173 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
174 	if (error || newp == NULL)
175 		return error;
176 
177 	if (newval < veriexec_strict)
178 		return EPERM;
179 
180 	veriexec_strict = newval;
181 
182 	return 0;
183 }
184 
185 SYSCTL_SETUP(sysctl_kern_veriexec_setup, "sysctl kern.veriexec setup")
186 {
187 	const struct sysctlnode *rnode = NULL;
188 
189 	sysctl_createv(clog, 0, NULL, &rnode,
190 		       CTLFLAG_PERMANENT,
191 		       CTLTYPE_NODE, "veriexec",
192 		       SYSCTL_DESCR("Veriexec"),
193 		       NULL, 0, NULL, 0,
194 		       CTL_KERN, CTL_CREATE, CTL_EOL);
195 
196 	sysctl_createv(clog, 0, &rnode, NULL,
197 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
198 		       CTLTYPE_INT, "verbose",
199 		       SYSCTL_DESCR("Veriexec verbose level"),
200 		       NULL, 0, &veriexec_verbose, 0,
201 		       CTL_CREATE, CTL_EOL);
202 	sysctl_createv(clog, 0, &rnode, NULL,
203 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
204 		       CTLTYPE_INT, "strict",
205 		       SYSCTL_DESCR("Veriexec strict level"),
206 		       sysctl_kern_veriexec_strict, 0, NULL, 0,
207 		       CTL_CREATE, CTL_EOL);
208 	sysctl_createv(clog, 0, &rnode, NULL,
209 		       CTLFLAG_PERMANENT,
210 		       CTLTYPE_STRING, "algorithms",
211 		       SYSCTL_DESCR("Veriexec supported hashing "
212 				    "algorithms"),
213 		       sysctl_kern_veriexec_algorithms, 0, NULL, 0,
214 		       CTL_CREATE, CTL_EOL);
215 	sysctl_createv(clog, 0, &rnode, &veriexec_count_node,
216 		       CTLFLAG_PERMANENT,
217 		       CTLTYPE_NODE, "count",
218 		       SYSCTL_DESCR("Number of fingerprints on mount(s)"),
219 		       NULL, 0, NULL, 0,
220 		       CTL_CREATE, CTL_EOL);
221 }
222 
223 /*
224  * Add ops to the fingerprint ops vector list.
225  */
226 int
227 veriexec_fpops_add(const char *fp_type, size_t hash_len, size_t ctx_size,
228     veriexec_fpop_init_t init, veriexec_fpop_update_t update,
229     veriexec_fpop_final_t final)
230 {
231 	struct veriexec_fpops *ops;
232 
233 	KASSERT((init != NULL) && (update != NULL) && (final != NULL));
234 	KASSERT((hash_len != 0) && (ctx_size != 0));
235 	KASSERT(fp_type != NULL);
236 
237 	if (veriexec_fpops_lookup(fp_type) != NULL)
238 		return (EEXIST);
239 
240 	ops = kmem_alloc(sizeof(*ops), KM_SLEEP);
241 	ops->type = fp_type;
242 	ops->hash_len = hash_len;
243 	ops->context_size = ctx_size;
244 	ops->init = init;
245 	ops->update = update;
246 	ops->final = final;
247 
248 	LIST_INSERT_HEAD(&veriexec_fpops_list, ops, entries);
249 
250 	/*
251 	 * If we don't have space for any names, allocate enough for six
252 	 * which should be sufficient. (it's also enough for all algorithms
253 	 * we can support at the moment)
254 	 */
255 	if (veriexec_fp_names == NULL) {
256 		veriexec_name_max = 64;
257 		veriexec_fp_names = kmem_zalloc(veriexec_name_max, KM_SLEEP);
258 	}
259 
260 	/*
261 	 * If we're running out of space for storing supported algorithms,
262 	 * extend the buffer with space for four names.
263 	 */
264 	while (veriexec_name_max - (strlen(veriexec_fp_names) + 1) <
265 	    strlen(fp_type)) {
266 		char *newp;
267 		unsigned int new_max;
268 
269 		/* Add space for four algorithm names. */
270 		new_max = veriexec_name_max + 64;
271 		newp = kmem_zalloc(new_max, KM_SLEEP);
272 		strlcpy(newp, veriexec_fp_names, new_max);
273 		kmem_free(veriexec_fp_names, veriexec_name_max);
274 		veriexec_fp_names = newp;
275 		veriexec_name_max = new_max;
276 	}
277 
278 	if (*veriexec_fp_names != '\0')
279 		strlcat(veriexec_fp_names, " ", veriexec_name_max);
280 
281 	strlcat(veriexec_fp_names, fp_type, veriexec_name_max);
282 
283 	return (0);
284 }
285 
286 static void
287 veriexec_mountspecific_dtor(void *v)
288 {
289 	struct veriexec_table_entry *vte = v;
290 
291 	if (vte == NULL) {
292 		return;
293 	}
294 	sysctl_free(__UNCONST(vte->vte_node));
295 	veriexec_tablecount--;
296 	kmem_free(vte, sizeof(*vte));
297 }
298 
299 static int
300 veriexec_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
301     void *arg0, void *arg1, void *arg2, void *arg3)
302 {
303 	int result;
304 	enum kauth_system_req req;
305 
306 	if (action != KAUTH_SYSTEM_VERIEXEC)
307 		return KAUTH_RESULT_DEFER;
308 
309 	result = KAUTH_RESULT_DEFER;
310 	req = (enum kauth_system_req)arg0;
311 
312 	if (req == KAUTH_REQ_SYSTEM_VERIEXEC_MODIFY &&
313 	    veriexec_strict > VERIEXEC_LEARNING) {
314 		log(LOG_WARNING, "Veriexec: Strict mode, modifying "
315 		    "tables not permitted.\n");
316 
317 		result = KAUTH_RESULT_DENY;
318 	}
319 
320 	return result;
321 }
322 
323 /*
324  * Initialise Veriexec.
325  */
326 void
327 veriexec_init(void)
328 {
329 	int error;
330 
331 	/* Register a fileassoc for Veriexec. */
332 	error = fileassoc_register("veriexec",
333 	    (fileassoc_cleanup_cb_t)veriexec_file_free, &veriexec_hook);
334 	if (error)
335 		panic("Veriexec: Can't register fileassoc: error=%d", error);
336 
337 	/* Register listener to handle raw disk access. */
338 	if (kauth_listen_scope(KAUTH_SCOPE_DEVICE, veriexec_raw_cb, NULL) ==
339 	    NULL)
340 		panic("Veriexec: Can't listen on device scope");
341 
342 	error = mount_specific_key_create(&veriexec_mountspecific_key,
343 	    veriexec_mountspecific_dtor);
344 	if (error)
345 		panic("Veriexec: Can't create mountspecific key");
346 
347 	if (kauth_listen_scope(KAUTH_SCOPE_SYSTEM, veriexec_listener_cb,
348 	    NULL) == NULL)
349 		panic("Veriexec: Can't listen on system scope");
350 
351 	rw_init(&veriexec_op_lock);
352 
353 #define	FPOPS_ADD(a, b, c, d, e, f)	\
354 	veriexec_fpops_add(a, b, c, (veriexec_fpop_init_t)d, \
355 	 (veriexec_fpop_update_t)e, (veriexec_fpop_final_t)f)
356 
357 #ifdef VERIFIED_EXEC_FP_SHA256
358 	FPOPS_ADD("SHA256", SHA256_DIGEST_LENGTH, sizeof(SHA256_CTX),
359 	    SHA256_Init, SHA256_Update, SHA256_Final);
360 #endif /* VERIFIED_EXEC_FP_SHA256 */
361 
362 #ifdef VERIFIED_EXEC_FP_SHA384
363 	FPOPS_ADD("SHA384", SHA384_DIGEST_LENGTH, sizeof(SHA384_CTX),
364 	    SHA384_Init, SHA384_Update, SHA384_Final);
365 #endif /* VERIFIED_EXEC_FP_SHA384 */
366 
367 #ifdef VERIFIED_EXEC_FP_SHA512
368 	FPOPS_ADD("SHA512", SHA512_DIGEST_LENGTH, sizeof(SHA512_CTX),
369 	    SHA512_Init, SHA512_Update, SHA512_Final);
370 #endif /* VERIFIED_EXEC_FP_SHA512 */
371 
372 #undef FPOPS_ADD
373 }
374 
375 static struct veriexec_fpops *
376 veriexec_fpops_lookup(const char *name)
377 {
378 	struct veriexec_fpops *ops;
379 
380 	if (name == NULL)
381 		return (NULL);
382 
383 	LIST_FOREACH(ops, &veriexec_fpops_list, entries) {
384 		if (strcasecmp(name, ops->type) == 0)
385 			return (ops);
386 	}
387 
388 	return (NULL);
389 }
390 
391 /*
392  * Calculate fingerprint. Information on hash length and routines used is
393  * extracted from veriexec_hash_list according to the hash type.
394  *
395  * NOTE: vfe is assumed to be locked for writing on entry.
396  */
397 static int
398 veriexec_fp_calc(struct lwp *l, struct vnode *vp, int file_lock_state,
399     struct veriexec_file_entry *vfe, u_char *fp)
400 {
401 	struct vattr va;
402 	void *ctx;
403 	u_char *buf;
404 	off_t offset, len;
405 	size_t resid;
406 	int error;
407 
408 	KASSERT(file_lock_state != VERIEXEC_LOCKED);
409 	KASSERT(file_lock_state != VERIEXEC_UNLOCKED);
410 
411 	if (file_lock_state == VERIEXEC_FILE_UNLOCKED)
412 		vn_lock(vp, LK_SHARED | LK_RETRY);
413 	error = VOP_GETATTR(vp, &va, l->l_cred);
414 	if (file_lock_state == VERIEXEC_FILE_UNLOCKED)
415 		VOP_UNLOCK(vp);
416 	if (error)
417 		return (error);
418 
419 	ctx = kmem_alloc(vfe->ops->context_size, KM_SLEEP);
420 	buf = kmem_alloc(PAGE_SIZE, KM_SLEEP);
421 
422 	(vfe->ops->init)(ctx);
423 
424 	len = 0;
425 	error = 0;
426 	for (offset = 0; offset < va.va_size; offset += PAGE_SIZE) {
427 		len = ((va.va_size - offset) < PAGE_SIZE) ?
428 		    (va.va_size - offset) : PAGE_SIZE;
429 
430 		error = vn_rdwr(UIO_READ, vp, buf, len, offset,
431 				UIO_SYSSPACE,
432 				((file_lock_state == VERIEXEC_FILE_LOCKED)?
433 				 IO_NODELOCKED : 0),
434 				l->l_cred, &resid, NULL);
435 
436 		if (error) {
437 			goto bad;
438 		}
439 
440 		(vfe->ops->update)(ctx, buf, (unsigned int) len);
441 
442 		if (len != PAGE_SIZE)
443 			break;
444 	}
445 
446 	(vfe->ops->final)(fp, ctx);
447 
448 bad:
449 	kmem_free(ctx, vfe->ops->context_size);
450 	kmem_free(buf, PAGE_SIZE);
451 
452 	return (error);
453 }
454 
455 /* Compare two fingerprints of the same type. */
456 static int
457 veriexec_fp_cmp(struct veriexec_fpops *ops, u_char *fp1, u_char *fp2)
458 {
459 	if (veriexec_verbose >= 2) {
460 		int i;
461 
462 		printf("comparing hashes...\n");
463 		printf("fp1: ");
464 		for (i = 0; i < ops->hash_len; i++) {
465 			printf("%02x", fp1[i]);
466 		}
467 		printf("\nfp2: ");
468 		for (i = 0; i < ops->hash_len; i++) {
469 			printf("%02x", fp2[i]);
470 		}
471 		printf("\n");
472 	}
473 
474 	return (memcmp(fp1, fp2, ops->hash_len));
475 }
476 
477 static int
478 veriexec_fp_status(struct lwp *l, struct vnode *vp, int file_lock_state,
479     struct veriexec_file_entry *vfe, u_char *status)
480 {
481 	size_t hash_len = vfe->ops->hash_len;
482 	u_char *digest;
483 	int error;
484 
485 	digest = kmem_zalloc(hash_len, KM_SLEEP);
486 
487 	error = veriexec_fp_calc(l, vp, file_lock_state, vfe, digest);
488 	if (error)
489 		goto out;
490 
491 	/* Compare fingerprint with loaded data. */
492 	if (veriexec_fp_cmp(vfe->ops, vfe->fp, digest) == 0)
493 		*status = FINGERPRINT_VALID;
494 	else
495 		*status = FINGERPRINT_NOMATCH;
496 
497 out:
498 	kmem_free(digest, hash_len);
499 	return error;
500 }
501 
502 
503 static struct veriexec_table_entry *
504 veriexec_table_lookup(struct mount *mp)
505 {
506 	/* XXX: From raidframe init */
507 	if (mp == NULL)
508 		return NULL;
509 
510 	return mount_getspecific(mp, veriexec_mountspecific_key);
511 }
512 
513 static struct veriexec_file_entry *
514 veriexec_get(struct vnode *vp)
515 {
516 	return (fileassoc_lookup(vp, veriexec_hook));
517 }
518 
519 bool
520 veriexec_lookup(struct vnode *vp)
521 {
522 	return (veriexec_get(vp) == NULL ? false : true);
523 }
524 
525 /*
526  * Routine for maintaining mostly consistent message formats in Veriexec.
527  */
528 static void
529 veriexec_file_report(struct veriexec_file_entry *vfe, const u_char *msg,
530     const u_char *filename, struct lwp *l, int f)
531 {
532 	if (vfe != NULL && vfe->filename != NULL)
533 		filename = vfe->filename;
534 	if (filename == NULL)
535 		return;
536 
537 	if (((f & REPORT_LOGMASK) >> 1) <= veriexec_verbose) {
538 		if (!(f & REPORT_ALARM) || (l == NULL))
539 			log(LOG_NOTICE, "Veriexec: %s [%s]\n", msg,
540 			    filename);
541 		else
542 			log(LOG_ALERT, "Veriexec: %s [%s, prog=%s pid=%u, "
543 			    "uid=%u, gid=%u]\n", msg, filename,
544 			    l->l_proc->p_comm, l->l_proc->p_pid,
545 			    kauth_cred_getuid(l->l_cred),
546 			    kauth_cred_getgid(l->l_cred));
547 	}
548 
549 	if (f & REPORT_PANIC)
550 		panic("Veriexec: Unrecoverable error.");
551 }
552 
553 /*
554  * Verify the fingerprint of the given file. If we're called directly from
555  * sys_execve(), 'flag' will be VERIEXEC_DIRECT. If we're called from
556  * exec_script(), 'flag' will be VERIEXEC_INDIRECT.  If we are called from
557  * vn_open(), 'flag' will be VERIEXEC_FILE.
558  *
559  * 'veriexec_op_lock' must be locked (and remains locked).
560  *
561  * NOTE: The veriexec file entry pointer (vfep) will be returned LOCKED
562  *       on no error.
563  */
564 static int
565 veriexec_file_verify(struct lwp *l, struct vnode *vp, const u_char *name,
566     int flag, int file_lock_state, struct veriexec_file_entry **vfep)
567 {
568 	struct veriexec_file_entry *vfe;
569 	int error = 0;
570 
571 	KASSERT(rw_lock_held(&veriexec_op_lock));
572 	KASSERT(file_lock_state != VERIEXEC_LOCKED);
573 	KASSERT(file_lock_state != VERIEXEC_UNLOCKED);
574 
575 #define VFE_NEEDS_EVAL(vfe) ((vfe->status == FINGERPRINT_NOTEVAL) || \
576 			     (vfe->type & VERIEXEC_UNTRUSTED))
577 
578 	if (vfep != NULL)
579 		*vfep = NULL;
580 
581 	if (vp->v_type != VREG)
582 		return (0);
583 
584 	/* Lookup veriexec table entry, save pointer if requested. */
585 	vfe = veriexec_get(vp);
586 	if (vfep != NULL)
587 		*vfep = vfe;
588 
589 	/* No entry in the veriexec tables. */
590 	if (vfe == NULL) {
591 		veriexec_file_report(NULL, "No entry.", name,
592 		    l, REPORT_VERBOSE);
593 
594 		/*
595 		 * Lockdown mode: Deny access to non-monitored files.
596 		 * IPS mode: Deny execution of non-monitored files.
597 		 */
598 		if ((veriexec_strict >= VERIEXEC_LOCKDOWN) ||
599 		    ((veriexec_strict >= VERIEXEC_IPS) &&
600 		     (flag != VERIEXEC_FILE)))
601 			return (EPERM);
602 
603 		return (0);
604 	}
605 
606 	/*
607 	 * Grab the lock for the entry, if we need to do an evaluation
608 	 * then the lock is a write lock, after we have the write
609 	 * lock, check if we really need it - some other thread may
610 	 * have already done the work for us.
611 	 */
612 	if (VFE_NEEDS_EVAL(vfe)) {
613 		rw_enter(&vfe->lock, RW_WRITER);
614 		if (!VFE_NEEDS_EVAL(vfe))
615 			rw_downgrade(&vfe->lock);
616 	} else
617 		rw_enter(&vfe->lock, RW_READER);
618 
619 	/* Evaluate fingerprint if needed. */
620 	if (VFE_NEEDS_EVAL(vfe)) {
621 		u_char status;
622 
623 		error = veriexec_fp_status(l, vp, file_lock_state, vfe, &status);
624 		if (error) {
625 			veriexec_file_report(vfe, "Fingerprint calculation error.",
626 			    name, NULL, REPORT_ALWAYS);
627 			rw_exit(&vfe->lock);
628 			return (error);
629 		}
630 		vfe->status = status;
631 		rw_downgrade(&vfe->lock);
632 	}
633 
634 	if (!(vfe->type & flag)) {
635 		veriexec_file_report(vfe, "Incorrect access type.", name, l,
636 		    REPORT_ALWAYS|REPORT_ALARM);
637 
638 		/* IPS mode: Enforce access type. */
639 		if (veriexec_strict >= VERIEXEC_IPS) {
640 			rw_exit(&vfe->lock);
641 			return (EPERM);
642 		}
643 	}
644 
645 	switch (vfe->status) {
646 	case FINGERPRINT_NOTEVAL:
647 		/* Should not happen. */
648 		rw_exit(&vfe->lock);
649 		veriexec_file_report(vfe, "Not-evaluated status "
650 		    "post evaluation; inconsistency detected.", name,
651 		    NULL, REPORT_ALWAYS|REPORT_PANIC);
652 		/* NOTREACHED */
653 
654 	case FINGERPRINT_VALID:
655 		/* Valid fingerprint. */
656 		veriexec_file_report(vfe, "Match.", name, NULL,
657 		    REPORT_VERBOSE);
658 
659 		break;
660 
661 	case FINGERPRINT_NOMATCH:
662 		/* Fingerprint mismatch. */
663 		veriexec_file_report(vfe, "Mismatch.", name,
664 		    NULL, REPORT_ALWAYS|REPORT_ALARM);
665 
666 		/* IDS mode: Deny access on fingerprint mismatch. */
667 		if (veriexec_strict >= VERIEXEC_IDS) {
668 			rw_exit(&vfe->lock);
669 			error = EPERM;
670 		}
671 
672 		break;
673 
674 	default:
675 		/* Should never happen. */
676 		rw_exit(&vfe->lock);
677 		veriexec_file_report(vfe, "Invalid status "
678 		    "post evaluation.", name, NULL, REPORT_ALWAYS|REPORT_PANIC);
679 		/* NOTREACHED */
680 	}
681 
682 	return (error);
683 }
684 
685 int
686 veriexec_verify(struct lwp *l, struct vnode *vp, const u_char *name, int flag,
687     bool *found)
688 {
689 	struct veriexec_file_entry *vfe;
690 	int r;
691 
692 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
693 		return 0;
694 
695 	rw_enter(&veriexec_op_lock, RW_READER);
696 	r = veriexec_file_verify(l, vp, name, flag, VERIEXEC_FILE_UNLOCKED,
697 	    &vfe);
698 	rw_exit(&veriexec_op_lock);
699 
700 	if ((r  == 0) && (vfe != NULL))
701 		rw_exit(&vfe->lock);
702 
703 	if (found != NULL)
704 		*found = (vfe != NULL) ? true : false;
705 
706 	return (r);
707 }
708 
709 /*
710  * Veriexec remove policy code.
711  */
712 int
713 veriexec_removechk(struct lwp *l, struct vnode *vp, const char *pathbuf)
714 {
715 	struct veriexec_file_entry *vfe;
716 	int error;
717 
718 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
719 		return 0;
720 
721 	rw_enter(&veriexec_op_lock, RW_READER);
722 	vfe = veriexec_get(vp);
723 	rw_exit(&veriexec_op_lock);
724 
725 	if (vfe == NULL) {
726 		/* Lockdown mode: Deny access to non-monitored files. */
727 		if (veriexec_strict >= VERIEXEC_LOCKDOWN)
728 			return (EPERM);
729 
730 		return (0);
731 	}
732 
733 	veriexec_file_report(vfe, "Remove request.", pathbuf, l,
734 	    REPORT_ALWAYS|REPORT_ALARM);
735 
736 	/* IDS mode: Deny removal of monitored files. */
737 	if (veriexec_strict >= VERIEXEC_IDS)
738 		error = EPERM;
739 	else
740 		error = veriexec_file_delete(l, vp);
741 
742 	return error;
743 }
744 
745 /*
746  * Veriexec rename policy.
747  *
748  * XXX: Once there's a way to hook after a successful rename, it would be
749  * XXX: nice to update vfe->filename to the new name if it's not NULL and
750  * XXX: the new name is absolute (ie., starts with a slash).
751  */
752 int
753 veriexec_renamechk(struct lwp *l, struct vnode *fromvp, const char *fromname,
754     struct vnode *tovp, const char *toname)
755 {
756 	struct veriexec_file_entry *fvfe = NULL, *tvfe = NULL;
757 
758 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
759 		return 0;
760 
761 	rw_enter(&veriexec_op_lock, RW_READER);
762 
763 	if (veriexec_strict >= VERIEXEC_LOCKDOWN) {
764 		log(LOG_ALERT, "Veriexec: Preventing rename of `%s' to "
765 		    "`%s', uid=%u, pid=%u: Lockdown mode.\n", fromname, toname,
766 		    kauth_cred_geteuid(l->l_cred), l->l_proc->p_pid);
767 		rw_exit(&veriexec_op_lock);
768 		return (EPERM);
769 	}
770 
771 	fvfe = veriexec_get(fromvp);
772 	if (tovp != NULL)
773 		tvfe = veriexec_get(tovp);
774 
775 	if ((fvfe == NULL) && (tvfe == NULL)) {
776 		/* None of them is monitored */
777 		rw_exit(&veriexec_op_lock);
778 		return 0;
779 	}
780 
781 	if (veriexec_strict >= VERIEXEC_IPS) {
782 		log(LOG_ALERT, "Veriexec: Preventing rename of `%s' "
783 		    "to `%s', uid=%u, pid=%u: IPS mode, %s "
784 		    "monitored.\n", fromname, toname,
785 		    kauth_cred_geteuid(l->l_cred),
786 		    l->l_proc->p_pid, (fvfe != NULL && tvfe != NULL) ?
787 		    "files" : "file");
788 		rw_exit(&veriexec_op_lock);
789 		return (EPERM);
790 	}
791 
792 	if (fvfe != NULL) {
793 		/*
794 		 * Monitored file is renamed; filename no longer relevant.
795 		 */
796 
797 		/*
798 		 * XXX: We could keep the buffer, and when (and if) updating the
799 		 * XXX: filename post-rename, re-allocate it only if it's not
800 		 * XXX: big enough for the new filename.
801 		 */
802 
803 		/* XXX: Get write lock on fvfe here? */
804 
805 		VERIEXEC_RW_UPGRADE(&veriexec_op_lock);
806 		/* once we have the op lock in write mode
807 		 * there should be no locks on any file
808 		 * entries so we can destroy the object.
809 		 */
810 
811 		if (fvfe->filename_len > 0)
812 			kmem_free(fvfe->filename, fvfe->filename_len);
813 
814 		fvfe->filename = NULL;
815 		fvfe->filename_len = 0;
816 
817 		rw_downgrade(&veriexec_op_lock);
818 	}
819 
820 	log(LOG_NOTICE, "Veriexec: %s file `%s' renamed to "
821 	    "%s file `%s', uid=%u, pid=%u.\n", (fvfe != NULL) ?
822 	    "Monitored" : "Non-monitored", fromname, (tvfe != NULL) ?
823 	    "monitored" : "non-monitored", toname,
824 	    kauth_cred_geteuid(l->l_cred), l->l_proc->p_pid);
825 
826 	rw_exit(&veriexec_op_lock);
827 
828 	if (tvfe != NULL) {
829 		/*
830 		 * Monitored file is overwritten. Remove the entry.
831 		 */
832 		(void)veriexec_file_delete(l, tovp);
833 	}
834 
835 	return (0);
836 }
837 
838 static void
839 veriexec_file_free(struct veriexec_file_entry *vfe)
840 {
841 	if (vfe != NULL) {
842 		if (vfe->fp != NULL)
843 			kmem_free(vfe->fp, vfe->ops->hash_len);
844 		if (vfe->filename != NULL)
845 			kmem_free(vfe->filename, vfe->filename_len);
846 		rw_destroy(&vfe->lock);
847 		kmem_free(vfe, sizeof(*vfe));
848 	}
849 }
850 
851 static void
852 veriexec_file_purge(struct veriexec_file_entry *vfe, int have_lock)
853 {
854 	if (vfe == NULL)
855 		return;
856 
857 	if (have_lock == VERIEXEC_UNLOCKED)
858 		rw_enter(&vfe->lock, RW_WRITER);
859 	else
860 		VERIEXEC_RW_UPGRADE(&vfe->lock);
861 
862 	vfe->status = FINGERPRINT_NOTEVAL;
863 	if (have_lock == VERIEXEC_UNLOCKED)
864 		rw_exit(&vfe->lock);
865 	else
866 		rw_downgrade(&vfe->lock);
867 }
868 
869 static void
870 veriexec_file_purge_cb(struct veriexec_file_entry *vfe, void *cookie)
871 {
872 	veriexec_file_purge(vfe, VERIEXEC_UNLOCKED);
873 }
874 
875 /*
876  * Invalidate a Veriexec file entry.
877  * XXX: This should be updated when per-page fingerprints are added.
878  */
879 void
880 veriexec_purge(struct vnode *vp)
881 {
882 	rw_enter(&veriexec_op_lock, RW_READER);
883 	veriexec_file_purge(veriexec_get(vp), VERIEXEC_UNLOCKED);
884 	rw_exit(&veriexec_op_lock);
885 }
886 
887 /*
888  * Enforce raw disk access policy.
889  *
890  * IDS mode: Invalidate fingerprints on a mount if it's opened for writing.
891  * IPS mode: Don't allow raw writing to disks we monitor.
892  * Lockdown mode: Don't allow raw writing to all disks.
893  *
894  * XXX: This is bogus. There's an obvious race condition between the time
895  * XXX: the disk is open for writing, in which an attacker can access a
896  * XXX: monitored file to get its signature cached again, and when the raw
897  * XXX: file is overwritten on disk.
898  * XXX:
899  * XXX: To solve this, we need something like the following:
900  * XXX:		open raw disk:
901  * XXX:		  - raise refcount,
902  * XXX:		  - invalidate fingerprints,
903  * XXX:		  - mark all entries for that disk with "no cache" flag
904  * XXX:
905  * XXX:		veriexec_verify:
906  * XXX:		  - if "no cache", don't cache evaluation result
907  * XXX:
908  * XXX:		close raw disk:
909  * XXX:		  - lower refcount,
910  * XXX:		  - if refcount == 0, remove "no cache" flag from all entries
911  */
912 static int
913 veriexec_raw_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
914     void *arg0, void *arg1, void *arg2, void *arg3)
915 {
916 	int result;
917 	enum kauth_device_req req;
918 	struct veriexec_table_entry *vte;
919 
920 	result = KAUTH_RESULT_DENY;
921 	req = (enum kauth_device_req)arg0;
922 
923 	switch (action) {
924 	case KAUTH_DEVICE_RAWIO_SPEC: {
925 		struct vnode *vp, *bvp;
926 		int error;
927 
928 		if (req == KAUTH_REQ_DEVICE_RAWIO_SPEC_READ) {
929 			result = KAUTH_RESULT_DEFER;
930 			break;
931 		}
932 
933 		vp = arg1;
934 		KASSERT(vp != NULL);
935 
936 		/* Handle /dev/mem and /dev/kmem. */
937 		if (iskmemvp(vp)) {
938 			if (veriexec_strict < VERIEXEC_IPS)
939 				result = KAUTH_RESULT_DEFER;
940 
941 			break;
942 		}
943 
944 		error = rawdev_mounted(vp, &bvp);
945 		if (error == EINVAL) {
946 			result = KAUTH_RESULT_DEFER;
947 			break;
948 		}
949 
950 		/*
951 		 * XXX: See vfs_mountedon() comment in rawdev_mounted().
952 		 */
953 		vte = veriexec_table_lookup(bvp->v_mount);
954 		if (vte == NULL) {
955 			result = KAUTH_RESULT_DEFER;
956 			break;
957 		}
958 
959 		switch (veriexec_strict) {
960 		case VERIEXEC_LEARNING:
961 		case VERIEXEC_IDS:
962 			result = KAUTH_RESULT_DEFER;
963 
964 			rw_enter(&veriexec_op_lock, RW_WRITER);
965 			fileassoc_table_run(bvp->v_mount, veriexec_hook,
966 			    (fileassoc_cb_t)veriexec_file_purge_cb, NULL);
967 			rw_exit(&veriexec_op_lock);
968 
969 			break;
970 		case VERIEXEC_IPS:
971 			result = KAUTH_RESULT_DENY;
972 			break;
973 		case VERIEXEC_LOCKDOWN:
974 			result = KAUTH_RESULT_DENY;
975 			break;
976 		}
977 
978 		break;
979 		}
980 
981 	case KAUTH_DEVICE_RAWIO_PASSTHRU:
982 		/* XXX What can we do here? */
983 		if (veriexec_strict < VERIEXEC_IPS)
984 			result = KAUTH_RESULT_DEFER;
985 
986 		break;
987 
988 	default:
989 		result = KAUTH_RESULT_DEFER;
990 		break;
991 	}
992 
993 	return (result);
994 }
995 
996 /*
997  * Create a new Veriexec table.
998  */
999 static struct veriexec_table_entry *
1000 veriexec_table_add(struct lwp *l, struct mount *mp)
1001 {
1002 	struct veriexec_table_entry *vte;
1003 	u_char buf[16];
1004 
1005 	vte = kmem_zalloc(sizeof(*vte), KM_SLEEP);
1006 	mount_setspecific(mp, veriexec_mountspecific_key, vte);
1007 
1008 	snprintf(buf, sizeof(buf), "table%u", veriexec_tablecount++);
1009 	sysctl_createv(NULL, 0, &veriexec_count_node, &vte->vte_node,
1010 		       0, CTLTYPE_NODE, buf, NULL, NULL, 0, NULL,
1011 		       0, CTL_CREATE, CTL_EOL);
1012 
1013 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
1014 		       CTLFLAG_READONLY, CTLTYPE_STRING, "mntpt",
1015 		       NULL, NULL, 0, mp->mnt_stat.f_mntonname,
1016 		       0, CTL_CREATE, CTL_EOL);
1017 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
1018 		       CTLFLAG_READONLY, CTLTYPE_STRING, "fstype",
1019 		       NULL, NULL, 0, mp->mnt_stat.f_fstypename,
1020 		       0, CTL_CREATE, CTL_EOL);
1021 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
1022 		       CTLFLAG_READONLY, CTLTYPE_QUAD, "nentries",
1023 		       NULL, NULL, 0, &vte->vte_count, 0, CTL_CREATE, CTL_EOL);
1024 
1025 	return (vte);
1026 }
1027 
1028 /*
1029  * Add a file to be monitored by Veriexec.
1030  *
1031  * Expected elements in dict: file, fp, fp-type, entry-type.
1032  */
1033 int
1034 veriexec_file_add(struct lwp *l, prop_dictionary_t dict)
1035 {
1036 	struct veriexec_table_entry *vte;
1037 	struct veriexec_file_entry *vfe = NULL;
1038 	struct veriexec_file_entry *ovfe;
1039 	struct vnode *vp;
1040 	const char *file, *fp_type;
1041 	int error;
1042 	bool ignore_dup = false;
1043 
1044 	if (!prop_dictionary_get_cstring_nocopy(dict, "file", &file))
1045 		return (EINVAL);
1046 
1047 	error = namei_simple_kernel(file, NSM_FOLLOW_NOEMULROOT, &vp);
1048 	if (error)
1049 		return (error);
1050 
1051 	/* Add only regular files. */
1052 	if (vp->v_type != VREG) {
1053 		log(LOG_ERR, "Veriexec: Not adding `%s': Not a regular file.\n",
1054 		    file);
1055 		error = EBADF;
1056 		goto out;
1057 	}
1058 
1059 	vfe = kmem_zalloc(sizeof(*vfe), KM_SLEEP);
1060 	rw_init(&vfe->lock);
1061 
1062 	/* Lookup fingerprint hashing algorithm. */
1063 	fp_type = prop_string_cstring_nocopy(prop_dictionary_get(dict,
1064 	    "fp-type"));
1065 	if ((vfe->ops = veriexec_fpops_lookup(fp_type)) == NULL) {
1066 		log(LOG_ERR, "Veriexec: Invalid or unknown fingerprint type "
1067 		    "`%s' for file `%s'.\n", fp_type, file);
1068 		error = EOPNOTSUPP;
1069 		goto out;
1070 	}
1071 
1072 	if (prop_data_size(prop_dictionary_get(dict, "fp")) !=
1073 	    vfe->ops->hash_len) {
1074 		log(LOG_ERR, "Veriexec: Bad fingerprint length for `%s'.\n",
1075 		    file);
1076 		error = EINVAL;
1077 		goto out;
1078 	}
1079 
1080 	vfe->fp = kmem_alloc(vfe->ops->hash_len, KM_SLEEP);
1081 	memcpy(vfe->fp, prop_data_data_nocopy(prop_dictionary_get(dict, "fp")),
1082 	    vfe->ops->hash_len);
1083 
1084 	rw_enter(&veriexec_op_lock, RW_WRITER);
1085 
1086 	/* Continue entry initialization. */
1087 	if (prop_dictionary_get_uint8(dict, "entry-type", &vfe->type) == FALSE)
1088 		vfe->type = 0;
1089 	else {
1090 		uint8_t extra_flags;
1091 
1092 		extra_flags = vfe->type & ~(VERIEXEC_DIRECT |
1093 		    VERIEXEC_INDIRECT | VERIEXEC_FILE | VERIEXEC_UNTRUSTED);
1094 		if (extra_flags) {
1095 			log(LOG_NOTICE, "Veriexec: Contaminated flags `0x%x' "
1096 			    "for `%s', skipping.\n", extra_flags, file);
1097 			error = EINVAL;
1098 			goto unlock_out;
1099 		}
1100 	}
1101 	if (!(vfe->type & (VERIEXEC_DIRECT | VERIEXEC_INDIRECT |
1102 	    VERIEXEC_FILE)))
1103 		vfe->type |= VERIEXEC_DIRECT;
1104 
1105 	vfe->status = FINGERPRINT_NOTEVAL;
1106 	if (prop_bool_true(prop_dictionary_get(dict, "keep-filename"))) {
1107 		vfe->filename = kmem_strdupsize(file, &vfe->filename_len,
1108 		    KM_SLEEP);
1109 	} else
1110 		vfe->filename = NULL;
1111 
1112 	if (prop_bool_true(prop_dictionary_get(dict, "eval-on-load")) ||
1113 	    (vfe->type & VERIEXEC_UNTRUSTED)) {
1114 		u_char status;
1115 
1116 		error = veriexec_fp_status(l, vp, VERIEXEC_FILE_UNLOCKED,
1117 		    vfe, &status);
1118 		if (error)
1119 			goto unlock_out;
1120 		vfe->status = status;
1121 	}
1122 
1123 	/*
1124 	 * If we already have an entry for this file, and it matches
1125 	 * the new entry exactly (except for the filename, which may
1126 	 * hard-linked!), we just ignore the new entry.  If the new
1127 	 * entry differs, report the error.
1128 	 */
1129 	if ((ovfe = veriexec_get(vp)) != NULL) {
1130 		error = EEXIST;
1131 		if (vfe->type == ovfe->type &&
1132 		    vfe->status == ovfe->status &&
1133 		    vfe->ops == ovfe->ops &&
1134 		    memcmp(vfe->fp, ovfe->fp, vfe->ops->hash_len) == 0)
1135 			ignore_dup = true;
1136 		goto unlock_out;
1137 	}
1138 
1139 	vte = veriexec_table_lookup(vp->v_mount);
1140 	if (vte == NULL)
1141 		vte = veriexec_table_add(l, vp->v_mount);
1142 
1143 	/* XXX if we bail below this, we might want to gc newly created vtes. */
1144 
1145 	error = fileassoc_add(vp, veriexec_hook, vfe);
1146 	if (error)
1147 		goto unlock_out;
1148 
1149 	vte->vte_count++;
1150 
1151 	veriexec_file_report(NULL, "New entry.", file, NULL, REPORT_DEBUG);
1152 	veriexec_bypass = 0;
1153 
1154   unlock_out:
1155 	rw_exit(&veriexec_op_lock);
1156 
1157   out:
1158 	vrele(vp);
1159 	if (error)
1160 		veriexec_file_free(vfe);
1161 
1162 	if (ignore_dup && error == EEXIST)
1163 		error = 0;
1164 
1165 	return (error);
1166 }
1167 
1168 int
1169 veriexec_table_delete(struct lwp *l, struct mount *mp)
1170 {
1171 	struct veriexec_table_entry *vte;
1172 
1173 	vte = veriexec_table_lookup(mp);
1174 	if (vte == NULL)
1175 		return (ENOENT);
1176 
1177 	veriexec_mountspecific_dtor(vte);
1178 	mount_setspecific(mp, veriexec_mountspecific_key, NULL);
1179 
1180 	return (fileassoc_table_clear(mp, veriexec_hook));
1181 }
1182 
1183 int
1184 veriexec_file_delete(struct lwp *l, struct vnode *vp)
1185 {
1186 	struct veriexec_table_entry *vte;
1187 	int error;
1188 
1189 	vte = veriexec_table_lookup(vp->v_mount);
1190 	if (vte == NULL)
1191 		return (ENOENT);
1192 
1193 	rw_enter(&veriexec_op_lock, RW_WRITER);
1194 	error = fileassoc_clear(vp, veriexec_hook);
1195 	rw_exit(&veriexec_op_lock);
1196 	if (!error) {
1197 		KASSERT(vte->vte_count > 0);
1198 		vte->vte_count--;
1199 	}
1200 
1201 	return (error);
1202 }
1203 
1204 /*
1205  * Convert Veriexec entry data to a dictionary readable by userland tools.
1206  */
1207 static void
1208 veriexec_file_convert(struct veriexec_file_entry *vfe, prop_dictionary_t rdict)
1209 {
1210 	if (vfe->filename)
1211 		prop_dictionary_set(rdict, "file",
1212 		    prop_string_create_cstring(vfe->filename));
1213 	prop_dictionary_set_uint8(rdict, "entry-type", vfe->type);
1214 	prop_dictionary_set_uint8(rdict, "status", vfe->status);
1215 	prop_dictionary_set(rdict, "fp-type",
1216 	    prop_string_create_cstring(vfe->ops->type));
1217 	prop_dictionary_set(rdict, "fp",
1218 	    prop_data_create_data(vfe->fp, vfe->ops->hash_len));
1219 }
1220 
1221 int
1222 veriexec_convert(struct vnode *vp, prop_dictionary_t rdict)
1223 {
1224 	struct veriexec_file_entry *vfe;
1225 
1226 	rw_enter(&veriexec_op_lock, RW_READER);
1227 
1228 	vfe = veriexec_get(vp);
1229 	if (vfe == NULL) {
1230 		rw_exit(&veriexec_op_lock);
1231 		return (ENOENT);
1232 	}
1233 
1234 	rw_enter(&vfe->lock, RW_READER);
1235 	veriexec_file_convert(vfe, rdict);
1236 	rw_exit(&vfe->lock);
1237 
1238 	rw_exit(&veriexec_op_lock);
1239 	return (0);
1240 }
1241 
1242 int
1243 veriexec_unmountchk(struct mount *mp)
1244 {
1245 	int error;
1246 
1247 	if ((veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
1248 	    || doing_shutdown)
1249 		return (0);
1250 
1251 	rw_enter(&veriexec_op_lock, RW_READER);
1252 
1253 	switch (veriexec_strict) {
1254 	case VERIEXEC_LEARNING:
1255 		error = 0;
1256 		break;
1257 
1258 	case VERIEXEC_IDS:
1259 		if (veriexec_table_lookup(mp) != NULL) {
1260 			log(LOG_INFO, "Veriexec: IDS mode, allowing unmount "
1261 			    "of \"%s\".\n", mp->mnt_stat.f_mntonname);
1262 		}
1263 
1264 		error = 0;
1265 		break;
1266 
1267 	case VERIEXEC_IPS: {
1268 		struct veriexec_table_entry *vte;
1269 
1270 		vte = veriexec_table_lookup(mp);
1271 		if ((vte != NULL) && (vte->vte_count > 0)) {
1272 			log(LOG_ALERT, "Veriexec: IPS mode, preventing"
1273 			    " unmount of \"%s\" with monitored files.\n",
1274 			    mp->mnt_stat.f_mntonname);
1275 
1276 			error = EPERM;
1277 		} else
1278 			error = 0;
1279 		break;
1280 		}
1281 
1282 	case VERIEXEC_LOCKDOWN:
1283 	default:
1284 		log(LOG_ALERT, "Veriexec: Lockdown mode, preventing unmount "
1285 		    "of \"%s\".\n", mp->mnt_stat.f_mntonname);
1286 		error = EPERM;
1287 		break;
1288 	}
1289 
1290 	rw_exit(&veriexec_op_lock);
1291 	return (error);
1292 }
1293 
1294 int
1295 veriexec_openchk(struct lwp *l, struct vnode *vp, const char *path, int fmode)
1296 {
1297 	struct veriexec_file_entry *vfe = NULL;
1298 	int error = 0;
1299 
1300 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
1301 		return 0;
1302 
1303 	if (vp == NULL) {
1304 		/* If no creation requested, let this fail normally. */
1305 		if (!(fmode & O_CREAT))
1306 			goto out;
1307 
1308 		/* Lockdown mode: Prevent creation of new files. */
1309 		if (veriexec_strict >= VERIEXEC_LOCKDOWN) {
1310 			log(LOG_ALERT, "Veriexec: Preventing new file "
1311 			    "creation in `%s'.\n", path);
1312 			error = EPERM;
1313 		}
1314 
1315 		goto out;
1316 	}
1317 
1318 	rw_enter(&veriexec_op_lock, RW_READER);
1319 	error = veriexec_file_verify(l, vp, path, VERIEXEC_FILE,
1320 				     VERIEXEC_FILE_LOCKED, &vfe);
1321 
1322 	if (error) {
1323 		rw_exit(&veriexec_op_lock);
1324 		goto out;
1325 	}
1326 
1327 	if ((vfe != NULL) && ((fmode & FWRITE) || (fmode & O_TRUNC))) {
1328 		veriexec_file_report(vfe, "Write access request.", path, l,
1329 		    REPORT_ALWAYS | REPORT_ALARM);
1330 
1331 		/* IPS mode: Deny write access to monitored files. */
1332 		if (veriexec_strict >= VERIEXEC_IPS)
1333 			error = EPERM;
1334 		else
1335 			veriexec_file_purge(vfe, VERIEXEC_LOCKED);
1336 	}
1337 
1338 	if (vfe != NULL)
1339 		rw_exit(&vfe->lock);
1340 
1341 	rw_exit(&veriexec_op_lock);
1342  out:
1343 	return (error);
1344 }
1345 
1346 static void
1347 veriexec_file_dump(struct veriexec_file_entry *vfe, prop_array_t entries)
1348 {
1349 	prop_dictionary_t entry;
1350 
1351 	/* If we don't have a filename, this is meaningless. */
1352 	if (vfe->filename == NULL)
1353 		return;
1354 
1355 	entry = prop_dictionary_create();
1356 
1357 	veriexec_file_convert(vfe, entry);
1358 
1359 	prop_array_add(entries, entry);
1360 }
1361 
1362 int
1363 veriexec_dump(struct lwp *l, prop_array_t rarray)
1364 {
1365 	mount_iterator_t *iter;
1366 	struct mount *mp;
1367 
1368 	mountlist_iterator_init(&iter);
1369 	while ((mp = mountlist_iterator_next(iter)) != NULL) {
1370 		fileassoc_table_run(mp, veriexec_hook,
1371 		    (fileassoc_cb_t)veriexec_file_dump, rarray);
1372 	}
1373 	mountlist_iterator_destroy(iter);
1374 
1375 	return (0);
1376 }
1377 
1378 int
1379 veriexec_flush(struct lwp *l)
1380 {
1381 	mount_iterator_t *iter;
1382 	struct mount *mp;
1383 	int error = 0;
1384 
1385 	mountlist_iterator_init(&iter);
1386 	while ((mp = mountlist_iterator_next(iter)) != NULL) {
1387 		int lerror;
1388 
1389 		lerror = veriexec_table_delete(l, mp);
1390 		if (lerror && lerror != ENOENT)
1391 			error = lerror;
1392 	}
1393 	mountlist_iterator_destroy(iter);
1394 
1395 	return (error);
1396 }
1397