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      1 /*	$NetBSD: kern_veriexec.c,v 1.29 2026/01/04 02:09:51 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2005, 2006 Elad Efrat <elad (at) NetBSD.org>
      5  * Copyright (c) 2005, 2006 Brett Lymn <blymn (at) 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 1.29 2026/01/04 02:09:51 riastradh Exp $");
     33 
     34 #include "opt_veriexec.h"
     35 
     36 #include <sys/param.h>
     37 #include <sys/types.h>
     38 
     39 #include <sys/conf.h>
     40 #include <sys/fcntl.h>
     41 #include <sys/fileassoc.h>
     42 #include <sys/inttypes.h>
     43 #include <sys/kauth.h>
     44 #include <sys/kmem.h>
     45 #include <sys/md5.h>
     46 #include <sys/mount.h>
     47 #include <sys/namei.h>
     48 #include <sys/once.h>
     49 #include <sys/proc.h>
     50 #include <sys/rmd160.h>
     51 #include <sys/rwlock.h>
     52 #include <sys/sdt.h>
     53 #include <sys/sha1.h>
     54 #include <sys/sha2.h>
     55 #include <sys/sysctl.h>
     56 #include <sys/syslog.h>
     57 #include <sys/verified_exec.h>
     58 #include <sys/vnode.h>
     59 
     60 #include <miscfs/specfs/specdev.h>
     61 
     62 #include <prop/proplib.h>
     63 
     64 /* Readable values for veriexec_file_report(). */
     65 #define	REPORT_ALWAYS		0x01	/* Always print */
     66 #define	REPORT_VERBOSE		0x02	/* Print when verbose >= 1 */
     67 #define	REPORT_DEBUG		0x04	/* Print when verbose >= 2 (debug) */
     68 #define	REPORT_PANIC		0x08	/* Call panic() */
     69 #define	REPORT_ALARM		0x10	/* Alarm - also print pid/uid/.. */
     70 #define	REPORT_LOGMASK		(REPORT_ALWAYS|REPORT_VERBOSE|REPORT_DEBUG)
     71 
     72 /* state of locking for veriexec_file_verify */
     73 #define VERIEXEC_UNLOCKED	0x00	/* Nothing locked, callee does it */
     74 #define VERIEXEC_LOCKED		0x01	/* Global op lock held */
     75 
     76 /* state of file locking for veriexec_file_verify */
     77 #define VERIEXEC_FILE_UNLOCKED	0x02	/* Nothing locked, callee does it */
     78 #define VERIEXEC_FILE_LOCKED	0x04	/* File locked */
     79 
     80 #define VERIEXEC_RW_UPGRADE(lock)	while((rw_tryupgrade(lock)) == 0){};
     81 
     82 struct veriexec_fpops {
     83 	const char *type;
     84 	size_t hash_len;
     85 	size_t context_size;
     86 	veriexec_fpop_init_t init;
     87 	veriexec_fpop_update_t update;
     88 	veriexec_fpop_final_t final;
     89 	LIST_ENTRY(veriexec_fpops) entries;
     90 };
     91 
     92 /* Veriexec per-file entry data. */
     93 struct veriexec_file_entry {
     94 	krwlock_t lock;				/* r/w lock */
     95 	u_char *filename;			/* File name. */
     96 	u_char type;				/* Entry type. */
     97 	u_char status;				/* Evaluation status. */
     98 	u_char *fp;				/* Fingerprint. */
     99 	struct veriexec_fpops *ops;		/* Fingerprint ops vector*/
    100 	size_t filename_len;			/* Length of filename. */
    101 };
    102 
    103 /* Veriexec per-table data. */
    104 struct veriexec_table_entry {
    105 	uint64_t vte_count;			/* Number of Veriexec entries. */
    106 	const struct sysctlnode *vte_node;
    107 };
    108 
    109 static int veriexec_verbose;
    110 static int veriexec_strict;
    111 static int veriexec_bypass = 1;
    112 
    113 static char *veriexec_fp_names = NULL;
    114 static size_t veriexec_name_max = 0;
    115 
    116 static const struct sysctlnode *veriexec_count_node;
    117 
    118 static fileassoc_t veriexec_hook;
    119 static specificdata_key_t veriexec_mountspecific_key;
    120 
    121 static LIST_HEAD(, veriexec_fpops) veriexec_fpops_list =
    122 	LIST_HEAD_INITIALIZER(veriexec_fpops_list);
    123 
    124 static int veriexec_raw_cb(kauth_cred_t, kauth_action_t, void *,
    125     void *, void *, void *, void *);
    126 static struct veriexec_fpops *veriexec_fpops_lookup(const char *);
    127 static void veriexec_file_free(struct veriexec_file_entry *);
    128 
    129 static unsigned int veriexec_tablecount = 0;
    130 
    131 /*
    132  * Veriexec operations global lock - most ops hold this as a read
    133  * lock, it is upgraded to a write lock when destroying veriexec file
    134  * table entries.
    135  */
    136 static krwlock_t veriexec_op_lock;
    137 
    138 /*
    139  * Sysctl helper routine for Veriexec.
    140  */
    141 static int
    142 sysctl_kern_veriexec_algorithms(SYSCTLFN_ARGS)
    143 {
    144 	size_t len;
    145 	int error;
    146 	const char *p;
    147 
    148 	if (newp != NULL)
    149 		return SET_ERROR(EPERM);
    150 
    151 	if (namelen != 0)
    152 		return SET_ERROR(EINVAL);
    153 
    154 	p = veriexec_fp_names == NULL ? "" : veriexec_fp_names;
    155 
    156 	len = strlen(p) + 1;
    157 
    158 	if (*oldlenp < len && oldp)
    159 		return SET_ERROR(ENOMEM);
    160 
    161 	if (oldp && (error = copyout(p, oldp, len)) != 0)
    162 		return error;
    163 
    164 	*oldlenp = len;
    165 	return 0;
    166 }
    167 
    168 static int
    169 sysctl_kern_veriexec_strict(SYSCTLFN_ARGS)
    170 {
    171 	struct sysctlnode node;
    172 	int error, newval;
    173 
    174 	node = *rnode;
    175 	node.sysctl_data = &newval;
    176 
    177 	newval = veriexec_strict;
    178 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    179 	if (error || newp == NULL)
    180 		return error;
    181 
    182 	if (newval < veriexec_strict)
    183 		return SET_ERROR(EPERM);
    184 
    185 	veriexec_strict = newval;
    186 
    187 	return 0;
    188 }
    189 
    190 SYSCTL_SETUP(sysctl_kern_veriexec_setup, "sysctl kern.veriexec setup")
    191 {
    192 	const struct sysctlnode *rnode = NULL;
    193 
    194 	sysctl_createv(clog, 0, NULL, &rnode,
    195 		       CTLFLAG_PERMANENT,
    196 		       CTLTYPE_NODE, "veriexec",
    197 		       SYSCTL_DESCR("Veriexec"),
    198 		       NULL, 0, NULL, 0,
    199 		       CTL_KERN, CTL_CREATE, CTL_EOL);
    200 
    201 	sysctl_createv(clog, 0, &rnode, NULL,
    202 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    203 		       CTLTYPE_INT, "verbose",
    204 		       SYSCTL_DESCR("Veriexec verbose level"),
    205 		       NULL, 0, &veriexec_verbose, 0,
    206 		       CTL_CREATE, CTL_EOL);
    207 	sysctl_createv(clog, 0, &rnode, NULL,
    208 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    209 		       CTLTYPE_INT, "strict",
    210 		       SYSCTL_DESCR("Veriexec strict level"),
    211 		       sysctl_kern_veriexec_strict, 0, NULL, 0,
    212 		       CTL_CREATE, CTL_EOL);
    213 	sysctl_createv(clog, 0, &rnode, NULL,
    214 		       CTLFLAG_PERMANENT,
    215 		       CTLTYPE_STRING, "algorithms",
    216 		       SYSCTL_DESCR("Veriexec supported hashing "
    217 				    "algorithms"),
    218 		       sysctl_kern_veriexec_algorithms, 0, NULL, 0,
    219 		       CTL_CREATE, CTL_EOL);
    220 	sysctl_createv(clog, 0, &rnode, &veriexec_count_node,
    221 		       CTLFLAG_PERMANENT,
    222 		       CTLTYPE_NODE, "count",
    223 		       SYSCTL_DESCR("Number of fingerprints on mount(s)"),
    224 		       NULL, 0, NULL, 0,
    225 		       CTL_CREATE, CTL_EOL);
    226 }
    227 
    228 /*
    229  * Add ops to the fingerprint ops vector list.
    230  */
    231 int
    232 veriexec_fpops_add(const char *fp_type, size_t hash_len, size_t ctx_size,
    233     veriexec_fpop_init_t init, veriexec_fpop_update_t update,
    234     veriexec_fpop_final_t final)
    235 {
    236 	struct veriexec_fpops *ops;
    237 
    238 	KASSERT(init != NULL);
    239 	KASSERT(update != NULL);
    240 	KASSERT(final != NULL);
    241 	KASSERT(hash_len != 0);
    242 	KASSERT(ctx_size != 0);
    243 	KASSERT(fp_type != NULL);
    244 
    245 	if (veriexec_fpops_lookup(fp_type) != NULL)
    246 		return SET_ERROR(EEXIST);
    247 
    248 	ops = kmem_alloc(sizeof(*ops), KM_SLEEP);
    249 	ops->type = fp_type;
    250 	ops->hash_len = hash_len;
    251 	ops->context_size = ctx_size;
    252 	ops->init = init;
    253 	ops->update = update;
    254 	ops->final = final;
    255 
    256 	LIST_INSERT_HEAD(&veriexec_fpops_list, ops, entries);
    257 
    258 	/*
    259 	 * If we don't have space for any names, allocate enough for six
    260 	 * which should be sufficient. (it's also enough for all algorithms
    261 	 * we can support at the moment)
    262 	 */
    263 	if (veriexec_fp_names == NULL) {
    264 		veriexec_name_max = 64;
    265 		veriexec_fp_names = kmem_zalloc(veriexec_name_max, KM_SLEEP);
    266 	}
    267 
    268 	/*
    269 	 * If we're running out of space for storing supported algorithms,
    270 	 * extend the buffer with space for four names.
    271 	 */
    272 	while (veriexec_name_max - (strlen(veriexec_fp_names) + 1) <
    273 	    strlen(fp_type)) {
    274 		char *newp;
    275 		unsigned int new_max;
    276 
    277 		/* Add space for four algorithm names. */
    278 		new_max = veriexec_name_max + 64;
    279 		newp = kmem_zalloc(new_max, KM_SLEEP);
    280 		strlcpy(newp, veriexec_fp_names, new_max);
    281 		kmem_free(veriexec_fp_names, veriexec_name_max);
    282 		veriexec_fp_names = newp;
    283 		veriexec_name_max = new_max;
    284 	}
    285 
    286 	if (*veriexec_fp_names != '\0')
    287 		strlcat(veriexec_fp_names, " ", veriexec_name_max);
    288 
    289 	strlcat(veriexec_fp_names, fp_type, veriexec_name_max);
    290 
    291 	return 0;
    292 }
    293 
    294 static void
    295 veriexec_mountspecific_dtor(void *v)
    296 {
    297 	struct veriexec_table_entry *vte = v;
    298 
    299 	if (vte == NULL) {
    300 		return;
    301 	}
    302 	sysctl_free(__UNCONST(vte->vte_node));
    303 	veriexec_tablecount--;
    304 	kmem_free(vte, sizeof(*vte));
    305 }
    306 
    307 static int
    308 veriexec_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    309     void *arg0, void *arg1, void *arg2, void *arg3)
    310 {
    311 	int result;
    312 	enum kauth_system_req req;
    313 
    314 	if (action != KAUTH_SYSTEM_VERIEXEC)
    315 		return KAUTH_RESULT_DEFER;
    316 
    317 	result = KAUTH_RESULT_DEFER;
    318 	req = (enum kauth_system_req)(uintptr_t)arg0;
    319 
    320 	if (req == KAUTH_REQ_SYSTEM_VERIEXEC_MODIFY &&
    321 	    veriexec_strict > VERIEXEC_LEARNING) {
    322 		log(LOG_WARNING, "Veriexec: Strict mode, modifying "
    323 		    "tables not permitted.\n");
    324 
    325 		result = KAUTH_RESULT_DENY;
    326 	}
    327 
    328 	return result;
    329 }
    330 
    331 /*
    332  * Initialise Veriexec.
    333  */
    334 void
    335 veriexec_init(void)
    336 {
    337 	int error;
    338 
    339 	/* Register a fileassoc for Veriexec. */
    340 	error = fileassoc_register("veriexec",
    341 	    (fileassoc_cleanup_cb_t)veriexec_file_free, &veriexec_hook);
    342 	if (error)
    343 		panic("Veriexec: Can't register fileassoc: error=%d", error);
    344 
    345 	/* Register listener to handle raw disk access. */
    346 	if (kauth_listen_scope(KAUTH_SCOPE_DEVICE, veriexec_raw_cb, NULL) ==
    347 	    NULL)
    348 		panic("Veriexec: Can't listen on device scope");
    349 
    350 	error = mount_specific_key_create(&veriexec_mountspecific_key,
    351 	    veriexec_mountspecific_dtor);
    352 	if (error)
    353 		panic("Veriexec: Can't create mountspecific key");
    354 
    355 	if (kauth_listen_scope(KAUTH_SCOPE_SYSTEM, veriexec_listener_cb,
    356 	    NULL) == NULL)
    357 		panic("Veriexec: Can't listen on system scope");
    358 
    359 	rw_init(&veriexec_op_lock);
    360 
    361 #define	FPOPS_ADD(a, b, c, d, e, f)			\
    362 	veriexec_fpops_add(a, b, c,			\
    363 	    __FPTRCAST(veriexec_fpop_init_t, d),	\
    364 	    __FPTRCAST(veriexec_fpop_update_t, e),	\
    365 	    __FPTRCAST(veriexec_fpop_final_t, f))
    366 
    367 #ifdef VERIFIED_EXEC_FP_SHA256
    368 	FPOPS_ADD("SHA256", SHA256_DIGEST_LENGTH, sizeof(SHA256_CTX),
    369 	    SHA256_Init, SHA256_Update, SHA256_Final);
    370 #endif /* VERIFIED_EXEC_FP_SHA256 */
    371 
    372 #ifdef VERIFIED_EXEC_FP_SHA384
    373 	FPOPS_ADD("SHA384", SHA384_DIGEST_LENGTH, sizeof(SHA384_CTX),
    374 	    SHA384_Init, SHA384_Update, SHA384_Final);
    375 #endif /* VERIFIED_EXEC_FP_SHA384 */
    376 
    377 #ifdef VERIFIED_EXEC_FP_SHA512
    378 	FPOPS_ADD("SHA512", SHA512_DIGEST_LENGTH, sizeof(SHA512_CTX),
    379 	    SHA512_Init, SHA512_Update, SHA512_Final);
    380 #endif /* VERIFIED_EXEC_FP_SHA512 */
    381 
    382 #undef FPOPS_ADD
    383 }
    384 
    385 static struct veriexec_fpops *
    386 veriexec_fpops_lookup(const char *name)
    387 {
    388 	struct veriexec_fpops *ops;
    389 
    390 	if (name == NULL)
    391 		return NULL;
    392 
    393 	LIST_FOREACH(ops, &veriexec_fpops_list, entries) {
    394 		if (strcasecmp(name, ops->type) == 0)
    395 			return ops;
    396 	}
    397 
    398 	return NULL;
    399 }
    400 
    401 /*
    402  * Calculate fingerprint. Information on hash length and routines used is
    403  * extracted from veriexec_hash_list according to the hash type.
    404  *
    405  * NOTE: vfe is assumed to be locked for writing on entry.
    406  */
    407 static int
    408 veriexec_fp_calc(struct lwp *l, struct vnode *vp, int file_lock_state,
    409     struct veriexec_file_entry *vfe, u_char *fp)
    410 {
    411 	struct vattr va;
    412 	void *ctx;
    413 	u_char *buf;
    414 	off_t offset, len;
    415 	size_t resid;
    416 	int error;
    417 
    418 	KASSERT(file_lock_state != VERIEXEC_LOCKED);
    419 	KASSERT(file_lock_state != VERIEXEC_UNLOCKED);
    420 
    421 	if (file_lock_state == VERIEXEC_FILE_UNLOCKED)
    422 		vn_lock(vp, LK_SHARED | LK_RETRY);
    423 	error = VOP_GETATTR(vp, &va, l->l_cred);
    424 	if (file_lock_state == VERIEXEC_FILE_UNLOCKED)
    425 		VOP_UNLOCK(vp);
    426 	if (error)
    427 		return error;
    428 
    429 	ctx = kmem_alloc(vfe->ops->context_size, KM_SLEEP);
    430 	buf = kmem_alloc(PAGE_SIZE, KM_SLEEP);
    431 
    432 	(vfe->ops->init)(ctx);
    433 
    434 	len = 0;
    435 	error = 0;
    436 	for (offset = 0; offset < va.va_size; offset += PAGE_SIZE) {
    437 		len = ((va.va_size - offset) < PAGE_SIZE) ?
    438 		    (va.va_size - offset) : PAGE_SIZE;
    439 
    440 		error = vn_rdwr(UIO_READ, vp, buf, len, offset,
    441 				UIO_SYSSPACE,
    442 				((file_lock_state == VERIEXEC_FILE_LOCKED)?
    443 				 IO_NODELOCKED : 0),
    444 				l->l_cred, &resid, NULL);
    445 
    446 		if (error) {
    447 			goto bad;
    448 		}
    449 
    450 		(vfe->ops->update)(ctx, buf, (unsigned int) len);
    451 
    452 		if (len != PAGE_SIZE)
    453 			break;
    454 	}
    455 
    456 	(vfe->ops->final)(fp, ctx);
    457 
    458 bad:
    459 	kmem_free(ctx, vfe->ops->context_size);
    460 	kmem_free(buf, PAGE_SIZE);
    461 
    462 	return error;
    463 }
    464 
    465 /* Compare two fingerprints of the same type. */
    466 static int
    467 veriexec_fp_cmp(struct veriexec_fpops *ops, u_char *fp1, u_char *fp2)
    468 {
    469 	if (veriexec_verbose >= 2) {
    470 		int i;
    471 
    472 		printf("comparing hashes...\n");
    473 		printf("fp1: ");
    474 		for (i = 0; i < ops->hash_len; i++) {
    475 			printf("%02x", fp1[i]);
    476 		}
    477 		printf("\nfp2: ");
    478 		for (i = 0; i < ops->hash_len; i++) {
    479 			printf("%02x", fp2[i]);
    480 		}
    481 		printf("\n");
    482 	}
    483 
    484 	return (memcmp(fp1, fp2, ops->hash_len));
    485 }
    486 
    487 static int
    488 veriexec_fp_status(struct lwp *l, struct vnode *vp, int file_lock_state,
    489     struct veriexec_file_entry *vfe, u_char *status)
    490 {
    491 	size_t hash_len = vfe->ops->hash_len;
    492 	u_char *digest;
    493 	int error;
    494 
    495 	digest = kmem_zalloc(hash_len, KM_SLEEP);
    496 
    497 	error = veriexec_fp_calc(l, vp, file_lock_state, vfe, digest);
    498 	if (error)
    499 		goto out;
    500 
    501 	/* Compare fingerprint with loaded data. */
    502 	if (veriexec_fp_cmp(vfe->ops, vfe->fp, digest) == 0)
    503 		*status = FINGERPRINT_VALID;
    504 	else
    505 		*status = FINGERPRINT_NOMATCH;
    506 
    507 out:
    508 	kmem_free(digest, hash_len);
    509 	return error;
    510 }
    511 
    512 
    513 static struct veriexec_table_entry *
    514 veriexec_table_lookup(struct mount *mp)
    515 {
    516 	/* XXX: From raidframe init */
    517 	if (mp == NULL)
    518 		return NULL;
    519 
    520 	return mount_getspecific(mp, veriexec_mountspecific_key);
    521 }
    522 
    523 static struct veriexec_file_entry *
    524 veriexec_get(struct vnode *vp)
    525 {
    526 	return (fileassoc_lookup(vp, veriexec_hook));
    527 }
    528 
    529 bool
    530 veriexec_lookup(struct vnode *vp)
    531 {
    532 	return (veriexec_get(vp) == NULL ? false : true);
    533 }
    534 
    535 /*
    536  * Routine for maintaining mostly consistent message formats in Veriexec.
    537  */
    538 static void
    539 veriexec_file_report(struct veriexec_file_entry *vfe, const u_char *msg,
    540     const u_char *filename, struct lwp *l, int f)
    541 {
    542 	if (vfe != NULL && vfe->filename != NULL)
    543 		filename = vfe->filename;
    544 	if (filename == NULL)
    545 		return;
    546 
    547 	if (((f & REPORT_LOGMASK) >> 1) <= veriexec_verbose) {
    548 		if (!(f & REPORT_ALARM) || (l == NULL))
    549 			log(LOG_NOTICE, "Veriexec: %s [%s]\n", msg,
    550 			    filename);
    551 		else
    552 			log(LOG_ALERT, "Veriexec: %s [%s, prog=%s pid=%u, "
    553 			    "uid=%u, gid=%u]\n", msg, filename,
    554 			    l->l_proc->p_comm, l->l_proc->p_pid,
    555 			    kauth_cred_getuid(l->l_cred),
    556 			    kauth_cred_getgid(l->l_cred));
    557 	}
    558 
    559 	if (f & REPORT_PANIC)
    560 		panic("Veriexec: Unrecoverable error.");
    561 }
    562 
    563 /*
    564  * Verify the fingerprint of the given file. If we're called directly from
    565  * sys_execve(), 'flag' will be VERIEXEC_DIRECT. If we're called from
    566  * exec_script(), 'flag' will be VERIEXEC_INDIRECT.  If we are called from
    567  * vn_open(), 'flag' will be VERIEXEC_FILE.
    568  *
    569  * 'veriexec_op_lock' must be locked (and remains locked).
    570  *
    571  * NOTE: The veriexec file entry pointer (vfep) will be returned LOCKED
    572  *       on no error.
    573  */
    574 static int
    575 veriexec_file_verify(struct lwp *l, struct vnode *vp, const u_char *name,
    576     int flag, int file_lock_state, struct veriexec_file_entry **vfep)
    577 {
    578 	struct veriexec_file_entry *vfe;
    579 	int error = 0;
    580 
    581 	KASSERT(rw_lock_held(&veriexec_op_lock));
    582 	KASSERT(file_lock_state != VERIEXEC_LOCKED);
    583 	KASSERT(file_lock_state != VERIEXEC_UNLOCKED);
    584 
    585 #define VFE_NEEDS_EVAL(vfe) ((vfe->status == FINGERPRINT_NOTEVAL) || \
    586 			     (vfe->type & VERIEXEC_UNTRUSTED))
    587 
    588 	if (vfep != NULL)
    589 		*vfep = NULL;
    590 
    591 	if (vp->v_type != VREG)
    592 		return 0;
    593 
    594 	/* Lookup veriexec table entry, save pointer if requested. */
    595 	vfe = veriexec_get(vp);
    596 	if (vfep != NULL)
    597 		*vfep = vfe;
    598 
    599 	/* No entry in the veriexec tables. */
    600 	if (vfe == NULL) {
    601 		veriexec_file_report(NULL, "No entry.", name,
    602 		    l, REPORT_VERBOSE);
    603 
    604 		/*
    605 		 * Lockdown mode: Deny access to non-monitored files.
    606 		 * IPS mode: Deny execution of non-monitored files.
    607 		 */
    608 		if ((veriexec_strict >= VERIEXEC_LOCKDOWN) ||
    609 		    ((veriexec_strict >= VERIEXEC_IPS) &&
    610 		     (flag != VERIEXEC_FILE)))
    611 			return SET_ERROR(EPERM);
    612 
    613 		return 0;
    614 	}
    615 
    616 	/*
    617 	 * Grab the lock for the entry, if we need to do an evaluation
    618 	 * then the lock is a write lock, after we have the write
    619 	 * lock, check if we really need it - some other thread may
    620 	 * have already done the work for us.
    621 	 */
    622 	if (VFE_NEEDS_EVAL(vfe)) {
    623 		rw_enter(&vfe->lock, RW_WRITER);
    624 		if (!VFE_NEEDS_EVAL(vfe))
    625 			rw_downgrade(&vfe->lock);
    626 	} else
    627 		rw_enter(&vfe->lock, RW_READER);
    628 
    629 	/* Evaluate fingerprint if needed. */
    630 	if (VFE_NEEDS_EVAL(vfe)) {
    631 		u_char status;
    632 
    633 		error = veriexec_fp_status(l, vp, file_lock_state, vfe, &status);
    634 		if (error) {
    635 			veriexec_file_report(vfe, "Fingerprint calculation error.",
    636 			    name, NULL, REPORT_ALWAYS);
    637 			rw_exit(&vfe->lock);
    638 			return error;
    639 		}
    640 		vfe->status = status;
    641 		rw_downgrade(&vfe->lock);
    642 	}
    643 
    644 	if (!(vfe->type & flag)) {
    645 		veriexec_file_report(vfe, "Incorrect access type.", name, l,
    646 		    REPORT_ALWAYS|REPORT_ALARM);
    647 
    648 		/* IPS mode: Enforce access type. */
    649 		if (veriexec_strict >= VERIEXEC_IPS) {
    650 			rw_exit(&vfe->lock);
    651 			return SET_ERROR(EPERM);
    652 		}
    653 	}
    654 
    655 	switch (vfe->status) {
    656 	case FINGERPRINT_NOTEVAL:
    657 		/* Should not happen. */
    658 		rw_exit(&vfe->lock);
    659 		veriexec_file_report(vfe, "Not-evaluated status "
    660 		    "post evaluation; inconsistency detected.", name,
    661 		    NULL, REPORT_ALWAYS|REPORT_PANIC);
    662 		__builtin_unreachable();
    663 		/* NOTREACHED */
    664 
    665 	case FINGERPRINT_VALID:
    666 		/* Valid fingerprint. */
    667 		veriexec_file_report(vfe, "Match.", name, NULL,
    668 		    REPORT_VERBOSE);
    669 
    670 		break;
    671 
    672 	case FINGERPRINT_NOMATCH:
    673 		/* Fingerprint mismatch. */
    674 		veriexec_file_report(vfe, "Mismatch.", name,
    675 		    NULL, REPORT_ALWAYS|REPORT_ALARM);
    676 
    677 		/* IDS mode: Deny access on fingerprint mismatch. */
    678 		if (veriexec_strict >= VERIEXEC_IDS) {
    679 			rw_exit(&vfe->lock);
    680 			error = SET_ERROR(EPERM);
    681 		}
    682 
    683 		break;
    684 
    685 	default:
    686 		/* Should never happen. */
    687 		rw_exit(&vfe->lock);
    688 		veriexec_file_report(vfe, "Invalid status "
    689 		    "post evaluation.", name, NULL, REPORT_ALWAYS|REPORT_PANIC);
    690 		/* NOTREACHED */
    691 	}
    692 
    693 	return error;
    694 }
    695 
    696 int
    697 veriexec_verify(struct lwp *l, struct vnode *vp, const u_char *name, int flag,
    698     bool *found)
    699 {
    700 	struct veriexec_file_entry *vfe;
    701 	int r;
    702 
    703 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
    704 		return 0;
    705 
    706 	rw_enter(&veriexec_op_lock, RW_READER);
    707 	r = veriexec_file_verify(l, vp, name, flag, VERIEXEC_FILE_UNLOCKED,
    708 	    &vfe);
    709 	rw_exit(&veriexec_op_lock);
    710 
    711 	if ((r  == 0) && (vfe != NULL))
    712 		rw_exit(&vfe->lock);
    713 
    714 	if (found != NULL)
    715 		*found = (vfe != NULL) ? true : false;
    716 
    717 	return r;
    718 }
    719 
    720 /*
    721  * Veriexec remove policy code.
    722  */
    723 int
    724 veriexec_removechk(struct lwp *l, struct vnode *vp, const char *pathbuf)
    725 {
    726 	struct veriexec_file_entry *vfe;
    727 	int error;
    728 
    729 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
    730 		return 0;
    731 
    732 	rw_enter(&veriexec_op_lock, RW_READER);
    733 	vfe = veriexec_get(vp);
    734 	rw_exit(&veriexec_op_lock);
    735 
    736 	if (vfe == NULL) {
    737 		/* Lockdown mode: Deny access to non-monitored files. */
    738 		if (veriexec_strict >= VERIEXEC_LOCKDOWN)
    739 			return SET_ERROR(EPERM);
    740 
    741 		return 0;
    742 	}
    743 
    744 	veriexec_file_report(vfe, "Remove request.", pathbuf, l,
    745 	    REPORT_ALWAYS|REPORT_ALARM);
    746 
    747 	/* IDS mode: Deny removal of monitored files. */
    748 	if (veriexec_strict >= VERIEXEC_IDS)
    749 		error = SET_ERROR(EPERM);
    750 	else
    751 		error = veriexec_file_delete(l, vp);
    752 
    753 	return error;
    754 }
    755 
    756 /*
    757  * Veriexec rename policy.
    758  *
    759  * XXX: Once there's a way to hook after a successful rename, it would be
    760  * XXX: nice to update vfe->filename to the new name if it's not NULL and
    761  * XXX: the new name is absolute (ie., starts with a slash).
    762  */
    763 int
    764 veriexec_renamechk(struct lwp *l, struct vnode *fromvp, const char *fromname,
    765     struct vnode *tovp, const char *toname)
    766 {
    767 	struct veriexec_file_entry *fvfe = NULL, *tvfe = NULL;
    768 
    769 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
    770 		return 0;
    771 
    772 	rw_enter(&veriexec_op_lock, RW_READER);
    773 
    774 	if (veriexec_strict >= VERIEXEC_LOCKDOWN) {
    775 		log(LOG_ALERT, "Veriexec: Preventing rename of `%s' to "
    776 		    "`%s', uid=%u, pid=%u: Lockdown mode.\n", fromname, toname,
    777 		    kauth_cred_geteuid(l->l_cred), l->l_proc->p_pid);
    778 		rw_exit(&veriexec_op_lock);
    779 		return SET_ERROR(EPERM);
    780 	}
    781 
    782 	fvfe = veriexec_get(fromvp);
    783 	if (tovp != NULL)
    784 		tvfe = veriexec_get(tovp);
    785 
    786 	if ((fvfe == NULL) && (tvfe == NULL)) {
    787 		/* None of them is monitored */
    788 		rw_exit(&veriexec_op_lock);
    789 		return 0;
    790 	}
    791 
    792 	if (veriexec_strict >= VERIEXEC_IPS) {
    793 		log(LOG_ALERT, "Veriexec: Preventing rename of `%s' "
    794 		    "to `%s', uid=%u, pid=%u: IPS mode, %s "
    795 		    "monitored.\n", fromname, toname,
    796 		    kauth_cred_geteuid(l->l_cred),
    797 		    l->l_proc->p_pid, (fvfe != NULL && tvfe != NULL) ?
    798 		    "files" : "file");
    799 		rw_exit(&veriexec_op_lock);
    800 		return SET_ERROR(EPERM);
    801 	}
    802 
    803 	if (fvfe != NULL) {
    804 		/*
    805 		 * Monitored file is renamed; filename no longer relevant.
    806 		 */
    807 
    808 		/*
    809 		 * XXX: We could keep the buffer, and when (and if) updating the
    810 		 * XXX: filename post-rename, re-allocate it only if it's not
    811 		 * XXX: big enough for the new filename.
    812 		 */
    813 
    814 		/* XXX: Get write lock on fvfe here? */
    815 
    816 		VERIEXEC_RW_UPGRADE(&veriexec_op_lock);
    817 		/* once we have the op lock in write mode
    818 		 * there should be no locks on any file
    819 		 * entries so we can destroy the object.
    820 		 */
    821 
    822 		if (fvfe->filename_len > 0)
    823 			kmem_free(fvfe->filename, fvfe->filename_len);
    824 
    825 		fvfe->filename = NULL;
    826 		fvfe->filename_len = 0;
    827 
    828 		rw_downgrade(&veriexec_op_lock);
    829 	}
    830 
    831 	log(LOG_NOTICE, "Veriexec: %s file `%s' renamed to "
    832 	    "%s file `%s', uid=%u, pid=%u.\n", (fvfe != NULL) ?
    833 	    "Monitored" : "Non-monitored", fromname, (tvfe != NULL) ?
    834 	    "monitored" : "non-monitored", toname,
    835 	    kauth_cred_geteuid(l->l_cred), l->l_proc->p_pid);
    836 
    837 	rw_exit(&veriexec_op_lock);
    838 
    839 	if (tvfe != NULL) {
    840 		/*
    841 		 * Monitored file is overwritten. Remove the entry.
    842 		 */
    843 		(void)veriexec_file_delete(l, tovp);
    844 	}
    845 
    846 	return 0;
    847 }
    848 
    849 static void
    850 veriexec_file_free(struct veriexec_file_entry *vfe)
    851 {
    852 	if (vfe != NULL) {
    853 		if (vfe->fp != NULL)
    854 			kmem_free(vfe->fp, vfe->ops->hash_len);
    855 		if (vfe->filename != NULL)
    856 			kmem_free(vfe->filename, vfe->filename_len);
    857 		rw_destroy(&vfe->lock);
    858 		kmem_free(vfe, sizeof(*vfe));
    859 	}
    860 }
    861 
    862 static void
    863 veriexec_file_purge(struct veriexec_file_entry *vfe, int have_lock)
    864 {
    865 	if (vfe == NULL)
    866 		return;
    867 
    868 	if (have_lock == VERIEXEC_UNLOCKED)
    869 		rw_enter(&vfe->lock, RW_WRITER);
    870 	else
    871 		VERIEXEC_RW_UPGRADE(&vfe->lock);
    872 
    873 	vfe->status = FINGERPRINT_NOTEVAL;
    874 	if (have_lock == VERIEXEC_UNLOCKED)
    875 		rw_exit(&vfe->lock);
    876 	else
    877 		rw_downgrade(&vfe->lock);
    878 }
    879 
    880 static void
    881 veriexec_file_purge_cb(struct veriexec_file_entry *vfe, void *cookie)
    882 {
    883 	veriexec_file_purge(vfe, VERIEXEC_UNLOCKED);
    884 }
    885 
    886 /*
    887  * Invalidate a Veriexec file entry.
    888  * XXX: This should be updated when per-page fingerprints are added.
    889  */
    890 void
    891 veriexec_purge(struct vnode *vp)
    892 {
    893 	rw_enter(&veriexec_op_lock, RW_READER);
    894 	veriexec_file_purge(veriexec_get(vp), VERIEXEC_UNLOCKED);
    895 	rw_exit(&veriexec_op_lock);
    896 }
    897 
    898 /*
    899  * Enforce raw disk access policy.
    900  *
    901  * IDS mode: Invalidate fingerprints on a mount if it's opened for writing.
    902  * IPS mode: Don't allow raw writing to disks we monitor.
    903  * Lockdown mode: Don't allow raw writing to all disks.
    904  *
    905  * XXX: This is bogus. There's an obvious race condition between the time
    906  * XXX: the disk is open for writing, in which an attacker can access a
    907  * XXX: monitored file to get its signature cached again, and when the raw
    908  * XXX: file is overwritten on disk.
    909  * XXX:
    910  * XXX: To solve this, we need something like the following:
    911  * XXX:		open raw disk:
    912  * XXX:		  - raise refcount,
    913  * XXX:		  - invalidate fingerprints,
    914  * XXX:		  - mark all entries for that disk with "no cache" flag
    915  * XXX:
    916  * XXX:		veriexec_verify:
    917  * XXX:		  - if "no cache", don't cache evaluation result
    918  * XXX:
    919  * XXX:		close raw disk:
    920  * XXX:		  - lower refcount,
    921  * XXX:		  - if refcount == 0, remove "no cache" flag from all entries
    922  */
    923 static int
    924 veriexec_raw_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    925     void *arg0, void *arg1, void *arg2, void *arg3)
    926 {
    927 	int result;
    928 	enum kauth_device_req req;
    929 	struct veriexec_table_entry *vte;
    930 
    931 	result = KAUTH_RESULT_DENY;
    932 	req = (enum kauth_device_req)(uintptr_t)arg0;
    933 
    934 	switch (action) {
    935 	case KAUTH_DEVICE_RAWIO_SPEC: {
    936 		struct vnode *vp, *bvp;
    937 		int error;
    938 
    939 		if (req == KAUTH_REQ_DEVICE_RAWIO_SPEC_READ) {
    940 			result = KAUTH_RESULT_DEFER;
    941 			break;
    942 		}
    943 
    944 		vp = arg1;
    945 		KASSERT(vp != NULL);
    946 
    947 		/* Handle /dev/mem and /dev/kmem. */
    948 		if (iskmemvp(vp)) {
    949 			if (veriexec_strict < VERIEXEC_IPS)
    950 				result = KAUTH_RESULT_DEFER;
    951 
    952 			break;
    953 		}
    954 
    955 		error = rawdev_mounted(vp, &bvp);
    956 		if (error == EINVAL) {
    957 			result = KAUTH_RESULT_DEFER;
    958 			break;
    959 		}
    960 
    961 		/*
    962 		 * XXX: See vfs_mountedon() comment in rawdev_mounted().
    963 		 */
    964 		vte = veriexec_table_lookup(bvp->v_mount);
    965 		if (vte == NULL) {
    966 			result = KAUTH_RESULT_DEFER;
    967 			break;
    968 		}
    969 
    970 		switch (veriexec_strict) {
    971 		case VERIEXEC_LEARNING:
    972 		case VERIEXEC_IDS:
    973 			result = KAUTH_RESULT_DEFER;
    974 
    975 			rw_enter(&veriexec_op_lock, RW_WRITER);
    976 			fileassoc_table_run(bvp->v_mount, veriexec_hook,
    977 			    (fileassoc_cb_t)veriexec_file_purge_cb, NULL);
    978 			rw_exit(&veriexec_op_lock);
    979 
    980 			break;
    981 		case VERIEXEC_IPS:
    982 			result = KAUTH_RESULT_DENY;
    983 			break;
    984 		case VERIEXEC_LOCKDOWN:
    985 			result = KAUTH_RESULT_DENY;
    986 			break;
    987 		}
    988 
    989 		break;
    990 		}
    991 
    992 	case KAUTH_DEVICE_RAWIO_PASSTHRU:
    993 		/* XXX What can we do here? */
    994 		if (veriexec_strict < VERIEXEC_IPS)
    995 			result = KAUTH_RESULT_DEFER;
    996 
    997 		break;
    998 
    999 	default:
   1000 		result = KAUTH_RESULT_DEFER;
   1001 		break;
   1002 	}
   1003 
   1004 	return result;
   1005 }
   1006 
   1007 /*
   1008  * Create a new Veriexec table.
   1009  */
   1010 static struct veriexec_table_entry *
   1011 veriexec_table_add(struct lwp *l, struct mount *mp)
   1012 {
   1013 	struct veriexec_table_entry *vte;
   1014 	u_char buf[16];
   1015 
   1016 	vte = kmem_zalloc(sizeof(*vte), KM_SLEEP);
   1017 	mount_setspecific(mp, veriexec_mountspecific_key, vte);
   1018 
   1019 	snprintf(buf, sizeof(buf), "table%u", veriexec_tablecount++);
   1020 	sysctl_createv(NULL, 0, &veriexec_count_node, &vte->vte_node,
   1021 		       0, CTLTYPE_NODE, buf, NULL, NULL, 0, NULL,
   1022 		       0, CTL_CREATE, CTL_EOL);
   1023 
   1024 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
   1025 		       CTLFLAG_READONLY, CTLTYPE_STRING, "mntpt",
   1026 		       NULL, NULL, 0, mp->mnt_stat.f_mntonname,
   1027 		       0, CTL_CREATE, CTL_EOL);
   1028 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
   1029 		       CTLFLAG_READONLY, CTLTYPE_STRING, "fstype",
   1030 		       NULL, NULL, 0, mp->mnt_stat.f_fstypename,
   1031 		       0, CTL_CREATE, CTL_EOL);
   1032 	sysctl_createv(NULL, 0, &vte->vte_node, NULL,
   1033 		       CTLFLAG_READONLY, CTLTYPE_QUAD, "nentries",
   1034 		       NULL, NULL, 0, &vte->vte_count, 0, CTL_CREATE, CTL_EOL);
   1035 
   1036 	return vte;
   1037 }
   1038 
   1039 /*
   1040  * Add a file to be monitored by Veriexec.
   1041  *
   1042  * Expected elements in dict:
   1043  *     file, fp, fp-type, entry-type, keep-filename, eval-on-load.
   1044  */
   1045 int
   1046 veriexec_file_add(struct lwp *l, prop_dictionary_t dict)
   1047 {
   1048 	struct veriexec_table_entry *vte;
   1049 	struct veriexec_file_entry *vfe = NULL;
   1050 	struct veriexec_file_entry *ovfe;
   1051 	struct vnode *vp;
   1052 	const char *file, *fp_type;
   1053 	int error;
   1054 	bool ignore_dup = false;
   1055 
   1056 	if (!prop_dictionary_get_string(dict, "file", &file))
   1057 		return SET_ERROR(EINVAL);
   1058 
   1059 	error = namei_simple_kernel(file, NSM_FOLLOW_NOEMULROOT, &vp);
   1060 	if (error)
   1061 		return error;
   1062 
   1063 	/* Add only regular files. */
   1064 	if (vp->v_type != VREG) {
   1065 		log(LOG_ERR, "Veriexec: Not adding `%s': Not a regular file.\n",
   1066 		    file);
   1067 		error = SET_ERROR(EBADF);
   1068 		goto out;
   1069 	}
   1070 
   1071 	vfe = kmem_zalloc(sizeof(*vfe), KM_SLEEP);
   1072 	rw_init(&vfe->lock);
   1073 
   1074 	/* Lookup fingerprint hashing algorithm. */
   1075 	fp_type = prop_string_value(prop_dictionary_get(dict, "fp-type"));
   1076 	if ((vfe->ops = veriexec_fpops_lookup(fp_type)) == NULL) {
   1077 		log(LOG_ERR, "Veriexec: Invalid or unknown fingerprint type "
   1078 		    "`%s' for file `%s'.\n", fp_type, file);
   1079 		error = SET_ERROR(EOPNOTSUPP);
   1080 		goto out;
   1081 	}
   1082 
   1083 	if (prop_data_size(prop_dictionary_get(dict, "fp")) !=
   1084 	    vfe->ops->hash_len) {
   1085 		log(LOG_ERR, "Veriexec: Bad fingerprint length for `%s'.\n",
   1086 		    file);
   1087 		error = SET_ERROR(EINVAL);
   1088 		goto out;
   1089 	}
   1090 
   1091 	vfe->fp = kmem_alloc(vfe->ops->hash_len, KM_SLEEP);
   1092 	memcpy(vfe->fp, prop_data_value(prop_dictionary_get(dict, "fp")),
   1093 	    vfe->ops->hash_len);
   1094 
   1095 	rw_enter(&veriexec_op_lock, RW_WRITER);
   1096 
   1097 	/* Continue entry initialization. */
   1098 	if (prop_dictionary_get_uint8(dict, "entry-type", &vfe->type) == FALSE)
   1099 		vfe->type = 0;
   1100 	else {
   1101 		uint8_t extra_flags;
   1102 
   1103 		extra_flags = vfe->type & ~(VERIEXEC_DIRECT |
   1104 		    VERIEXEC_INDIRECT | VERIEXEC_FILE | VERIEXEC_UNTRUSTED);
   1105 		if (extra_flags) {
   1106 			log(LOG_NOTICE, "Veriexec: Contaminated flags `0x%x' "
   1107 			    "for `%s', skipping.\n", extra_flags, file);
   1108 			error = SET_ERROR(EINVAL);
   1109 			goto unlock_out;
   1110 		}
   1111 	}
   1112 	if (!(vfe->type & (VERIEXEC_DIRECT | VERIEXEC_INDIRECT |
   1113 	    VERIEXEC_FILE)))
   1114 		vfe->type |= VERIEXEC_DIRECT;
   1115 
   1116 	vfe->status = FINGERPRINT_NOTEVAL;
   1117 	if (prop_bool_true(prop_dictionary_get(dict, "keep-filename"))) {
   1118 		vfe->filename = kmem_strdupsize(file, &vfe->filename_len,
   1119 		    KM_SLEEP);
   1120 	} else
   1121 		vfe->filename = NULL;
   1122 
   1123 	if (prop_bool_true(prop_dictionary_get(dict, "eval-on-load")) ||
   1124 	    (vfe->type & VERIEXEC_UNTRUSTED)) {
   1125 		u_char status;
   1126 
   1127 		error = veriexec_fp_status(l, vp, VERIEXEC_FILE_UNLOCKED,
   1128 		    vfe, &status);
   1129 		if (error)
   1130 			goto unlock_out;
   1131 		vfe->status = status;
   1132 	}
   1133 
   1134 	/*
   1135 	 * If we already have an entry for this file, and it matches
   1136 	 * the new entry exactly (except for the filename, which may
   1137 	 * hard-linked!), we just ignore the new entry.  If the new
   1138 	 * entry differs, report the error.
   1139 	 */
   1140 	if ((ovfe = veriexec_get(vp)) != NULL) {
   1141 		error = SET_ERROR(EEXIST);
   1142 		if (vfe->type == ovfe->type &&
   1143 		    vfe->status == ovfe->status &&
   1144 		    vfe->ops == ovfe->ops &&
   1145 		    memcmp(vfe->fp, ovfe->fp, vfe->ops->hash_len) == 0)
   1146 			ignore_dup = true;
   1147 		goto unlock_out;
   1148 	}
   1149 
   1150 	vte = veriexec_table_lookup(vp->v_mount);
   1151 	if (vte == NULL)
   1152 		vte = veriexec_table_add(l, vp->v_mount);
   1153 
   1154 	/* XXX if we bail below this, we might want to gc newly created vtes. */
   1155 
   1156 	error = fileassoc_add(vp, veriexec_hook, vfe);
   1157 	if (error)
   1158 		goto unlock_out;
   1159 
   1160 	vte->vte_count++;
   1161 
   1162 	veriexec_file_report(NULL, "New entry.", file, NULL, REPORT_DEBUG);
   1163 	veriexec_bypass = 0;
   1164 
   1165   unlock_out:
   1166 	rw_exit(&veriexec_op_lock);
   1167 
   1168   out:
   1169 	vrele(vp);
   1170 	if (error)
   1171 		veriexec_file_free(vfe);
   1172 
   1173 	if (ignore_dup && error == EEXIST)
   1174 		error = 0;
   1175 
   1176 	return error;
   1177 }
   1178 
   1179 int
   1180 veriexec_table_delete(struct lwp *l, struct mount *mp)
   1181 {
   1182 	struct veriexec_table_entry *vte;
   1183 
   1184 	vte = veriexec_table_lookup(mp);
   1185 	if (vte == NULL)
   1186 		return SET_ERROR(ENOENT);
   1187 
   1188 	veriexec_mountspecific_dtor(vte);
   1189 	mount_setspecific(mp, veriexec_mountspecific_key, NULL);
   1190 
   1191 	return (fileassoc_table_clear(mp, veriexec_hook));
   1192 }
   1193 
   1194 int
   1195 veriexec_file_delete(struct lwp *l, struct vnode *vp)
   1196 {
   1197 	struct veriexec_table_entry *vte;
   1198 	int error;
   1199 
   1200 	vte = veriexec_table_lookup(vp->v_mount);
   1201 	if (vte == NULL)
   1202 		return SET_ERROR(ENOENT);
   1203 
   1204 	rw_enter(&veriexec_op_lock, RW_WRITER);
   1205 	error = fileassoc_clear(vp, veriexec_hook);
   1206 	rw_exit(&veriexec_op_lock);
   1207 	if (!error) {
   1208 		KASSERT(vte->vte_count > 0);
   1209 		vte->vte_count--;
   1210 	}
   1211 
   1212 	return error;
   1213 }
   1214 
   1215 /*
   1216  * Convert Veriexec entry data to a dictionary readable by userland tools.
   1217  */
   1218 static void
   1219 veriexec_file_convert(struct veriexec_file_entry *vfe, prop_dictionary_t rdict)
   1220 {
   1221 	if (vfe->filename)
   1222 		prop_dictionary_set(rdict, "file",
   1223 		    prop_string_create_copy(vfe->filename));
   1224 	prop_dictionary_set_uint8(rdict, "entry-type", vfe->type);
   1225 	prop_dictionary_set_uint8(rdict, "status", vfe->status);
   1226 	prop_dictionary_set(rdict, "fp-type",
   1227 	    prop_string_create_copy(vfe->ops->type));
   1228 	prop_dictionary_set(rdict, "fp",
   1229 	    prop_data_create_copy(vfe->fp, vfe->ops->hash_len));
   1230 }
   1231 
   1232 int
   1233 veriexec_convert(struct vnode *vp, prop_dictionary_t rdict)
   1234 {
   1235 	struct veriexec_file_entry *vfe;
   1236 
   1237 	rw_enter(&veriexec_op_lock, RW_READER);
   1238 
   1239 	vfe = veriexec_get(vp);
   1240 	if (vfe == NULL) {
   1241 		rw_exit(&veriexec_op_lock);
   1242 		return SET_ERROR(ENOENT);
   1243 	}
   1244 
   1245 	rw_enter(&vfe->lock, RW_READER);
   1246 	veriexec_file_convert(vfe, rdict);
   1247 	rw_exit(&vfe->lock);
   1248 
   1249 	rw_exit(&veriexec_op_lock);
   1250 	return 0;
   1251 }
   1252 
   1253 int
   1254 veriexec_unmountchk(struct mount *mp)
   1255 {
   1256 	int error;
   1257 
   1258 	if ((veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
   1259 	    || doing_shutdown)
   1260 		return 0;
   1261 
   1262 	rw_enter(&veriexec_op_lock, RW_READER);
   1263 
   1264 	switch (veriexec_strict) {
   1265 	case VERIEXEC_LEARNING:
   1266 		error = 0;
   1267 		break;
   1268 
   1269 	case VERIEXEC_IDS:
   1270 		if (veriexec_table_lookup(mp) != NULL) {
   1271 			log(LOG_INFO, "Veriexec: IDS mode, allowing unmount "
   1272 			    "of \"%s\".\n", mp->mnt_stat.f_mntonname);
   1273 		}
   1274 
   1275 		error = 0;
   1276 		break;
   1277 
   1278 	case VERIEXEC_IPS: {
   1279 		struct veriexec_table_entry *vte;
   1280 
   1281 		vte = veriexec_table_lookup(mp);
   1282 		if ((vte != NULL) && (vte->vte_count > 0)) {
   1283 			log(LOG_ALERT, "Veriexec: IPS mode, preventing"
   1284 			    " unmount of \"%s\" with monitored files.\n",
   1285 			    mp->mnt_stat.f_mntonname);
   1286 
   1287 			error = SET_ERROR(EPERM);
   1288 		} else
   1289 			error = 0;
   1290 		break;
   1291 		}
   1292 
   1293 	case VERIEXEC_LOCKDOWN:
   1294 	default:
   1295 		log(LOG_ALERT, "Veriexec: Lockdown mode, preventing unmount "
   1296 		    "of \"%s\".\n", mp->mnt_stat.f_mntonname);
   1297 		error = SET_ERROR(EPERM);
   1298 		break;
   1299 	}
   1300 
   1301 	rw_exit(&veriexec_op_lock);
   1302 	return error;
   1303 }
   1304 
   1305 int
   1306 veriexec_openchk(struct lwp *l, struct vnode *vp, const char *path, int fmode)
   1307 {
   1308 	struct veriexec_file_entry *vfe = NULL;
   1309 	int error = 0;
   1310 
   1311 	if (veriexec_bypass && (veriexec_strict == VERIEXEC_LEARNING))
   1312 		return 0;
   1313 
   1314 	if (vp == NULL) {
   1315 		/* If no creation requested, let this fail normally. */
   1316 		if (!(fmode & O_CREAT))
   1317 			goto out;
   1318 
   1319 		/* Lockdown mode: Prevent creation of new files. */
   1320 		if (veriexec_strict >= VERIEXEC_LOCKDOWN) {
   1321 			log(LOG_ALERT, "Veriexec: Preventing new file "
   1322 			    "creation in `%s'.\n", path);
   1323 			error = SET_ERROR(EPERM);
   1324 		}
   1325 
   1326 		goto out;
   1327 	}
   1328 
   1329 	rw_enter(&veriexec_op_lock, RW_READER);
   1330 	error = veriexec_file_verify(l, vp, path, VERIEXEC_FILE,
   1331 				     VERIEXEC_FILE_LOCKED, &vfe);
   1332 
   1333 	if (error) {
   1334 		rw_exit(&veriexec_op_lock);
   1335 		goto out;
   1336 	}
   1337 
   1338 	if ((vfe != NULL) && ((fmode & FWRITE) || (fmode & O_TRUNC))) {
   1339 		veriexec_file_report(vfe, "Write access request.", path, l,
   1340 		    REPORT_ALWAYS | REPORT_ALARM);
   1341 
   1342 		/* IPS mode: Deny write access to monitored files. */
   1343 		if (veriexec_strict >= VERIEXEC_IPS)
   1344 			error = SET_ERROR(EPERM);
   1345 		else
   1346 			veriexec_file_purge(vfe, VERIEXEC_LOCKED);
   1347 	}
   1348 
   1349 	if (vfe != NULL)
   1350 		rw_exit(&vfe->lock);
   1351 
   1352 	rw_exit(&veriexec_op_lock);
   1353  out:
   1354 	return error;
   1355 }
   1356 
   1357 static void
   1358 veriexec_file_dump(struct veriexec_file_entry *vfe, prop_array_t entries)
   1359 {
   1360 	prop_dictionary_t entry;
   1361 
   1362 	/* If we don't have a filename, this is meaningless. */
   1363 	if (vfe->filename == NULL)
   1364 		return;
   1365 
   1366 	entry = prop_dictionary_create();
   1367 
   1368 	veriexec_file_convert(vfe, entry);
   1369 
   1370 	prop_array_add(entries, entry);
   1371 }
   1372 
   1373 int
   1374 veriexec_dump(struct lwp *l, prop_array_t rarray)
   1375 {
   1376 	mount_iterator_t *iter;
   1377 	struct mount *mp;
   1378 
   1379 	mountlist_iterator_init(&iter);
   1380 	while ((mp = mountlist_iterator_next(iter)) != NULL) {
   1381 		fileassoc_table_run(mp, veriexec_hook,
   1382 		    (fileassoc_cb_t)veriexec_file_dump, rarray);
   1383 	}
   1384 	mountlist_iterator_destroy(iter);
   1385 
   1386 	return 0;
   1387 }
   1388 
   1389 int
   1390 veriexec_flush(struct lwp *l)
   1391 {
   1392 	mount_iterator_t *iter;
   1393 	struct mount *mp;
   1394 	int error = 0;
   1395 
   1396 	mountlist_iterator_init(&iter);
   1397 	while ((mp = mountlist_iterator_next(iter)) != NULL) {
   1398 		int lerror;
   1399 
   1400 		lerror = veriexec_table_delete(l, mp);
   1401 		if (lerror && lerror != ENOENT)
   1402 			error = lerror;
   1403 	}
   1404 	mountlist_iterator_destroy(iter);
   1405 
   1406 	return error;
   1407 }
   1408