xref: /netbsd-src/sys/modules/lua/lua.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /*	$NetBSD: lua.c,v 1.13 2014/07/25 08:10:40 dholland Exp $ */
2 
3 /*
4  * Copyright (c) 2014 by Lourival Vieira Neto <lneto@NetBSD.org>.
5  * Copyright (c) 2011, 2013 by Marc Balmer <mbalmer@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 Author 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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /* Lua device driver */
33 
34 #include <sys/param.h>
35 #include <sys/fcntl.h>
36 #include <sys/conf.h>
37 #include <sys/condvar.h>
38 #include <sys/device.h>
39 #include <sys/ioctl.h>
40 #include <sys/kmem.h>
41 #include <sys/lock.h>
42 #include <sys/lua.h>
43 #include <sys/module.h>
44 #include <sys/mutex.h>
45 #include <sys/namei.h>
46 #include <sys/queue.h>
47 #include <sys/sysctl.h>
48 #include <sys/vnode.h>
49 #include <sys/cpu.h>
50 
51 #include <lauxlib.h>
52 
53 #include "luavar.h"
54 
55 struct lua_softc {
56 	device_t		 sc_dev;
57 
58 	kmutex_t		 sc_lock;
59 	kcondvar_t		 sc_inuse_cv;
60 	bool			 sc_inuse;
61 
62 	/* Locking access to state queues */
63 	kmutex_t		 sc_state_lock;
64 	kcondvar_t		 sc_state_cv;
65 	bool			 sc_state;
66 
67 	struct sysctllog	*sc_log;
68 };
69 
70 static device_t	sc_self;
71 static bool	lua_autoload_on = true;
72 static bool	lua_require_on = true;
73 static bool	lua_bytecode_on = false;
74 static int	lua_verbose;
75 static int	lua_max_instr;
76 
77 static LIST_HEAD(, lua_state)	lua_states;
78 static LIST_HEAD(, lua_module)	lua_modules;
79 
80 static int lua_match(device_t, cfdata_t, void *);
81 static void lua_attach(device_t, device_t, void *);
82 static int lua_detach(device_t, int);
83 static klua_State *klua_find(const char *);
84 static const char *lua_reader(lua_State *, void *, size_t *);
85 static void lua_maxcount(lua_State *, lua_Debug *);
86 
87 static int lua_require(lua_State *);
88 
89 CFATTACH_DECL_NEW(lua, sizeof(struct lua_softc),
90 	lua_match, lua_attach, lua_detach, NULL);
91 
92 dev_type_open(luaopen);
93 dev_type_close(luaclose);
94 dev_type_ioctl(luaioctl);
95 
96 const struct cdevsw lua_cdevsw = {
97 	.d_open = luaopen,
98 	.d_close = luaclose,
99 	.d_read = noread,
100 	.d_write = nowrite,
101 	.d_ioctl = luaioctl,
102 	.d_stop = nostop,
103 	.d_tty = notty,
104 	.d_poll = nopoll,
105 	.d_mmap = nommap,
106 	.d_kqfilter = nokqfilter,
107 	.d_discard = nodiscard,
108 	.d_flag = D_OTHER | D_MPSAFE
109 };
110 
111 struct lua_loadstate {
112 	struct vnode	*vp;
113 	size_t		 size;
114 	off_t		 off;
115 };
116 
117 extern struct cfdriver lua_cd;
118 
119 static int
120 lua_match(device_t parent, cfdata_t match, void *aux)
121 {
122 	return 1;
123 }
124 
125 static void
126 lua_attach(device_t parent, device_t self, void *aux)
127 {
128 	struct lua_softc *sc;
129 	const struct sysctlnode *node;
130 
131 	if (sc_self)
132 		return;
133 
134 	sc = device_private(self);
135 	sc->sc_dev = self;
136 	sc_self = self;
137 
138 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
139 	cv_init(&sc->sc_inuse_cv, "luactl");
140 
141 	mutex_init(&sc->sc_state_lock, MUTEX_DEFAULT, IPL_VM);
142 	cv_init(&sc->sc_state_cv, "luastate");
143 
144 	pmf_device_register(self, NULL, NULL);
145 
146 	/* Sysctl to provide some control over behaviour */
147         sysctl_createv(&sc->sc_log, 0, NULL, &node,
148             CTLFLAG_OWNDESC,
149             CTLTYPE_NODE, "lua",
150             SYSCTL_DESCR("Lua options"),
151             NULL, 0, NULL, 0,
152             CTL_KERN, CTL_CREATE, CTL_EOL);
153 
154         if (node == NULL) {
155 		printf(": can't create sysctl node\n");
156                 return;
157 	}
158 
159 	/*
160 	 * XXX Some of the sysctl values must not be changed after the
161 	 * securelevel has been raised.
162 	 */
163         sysctl_createv(&sc->sc_log, 0, &node, NULL,
164             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
165             CTLTYPE_BOOL, "require",
166             SYSCTL_DESCR("Enable the require command"),
167             NULL, 0, &lua_require_on, 0,
168 	    CTL_CREATE, CTL_EOL);
169 
170         sysctl_createv(&sc->sc_log, 0, &node, NULL,
171             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
172             CTLTYPE_BOOL, "autoload",
173             SYSCTL_DESCR("Enable automatic load of modules"),
174             NULL, 0, &lua_autoload_on, 0,
175 	    CTL_CREATE, CTL_EOL);
176 
177         sysctl_createv(&sc->sc_log, 0, &node, NULL,
178             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
179             CTLTYPE_BOOL, "bytecode",
180             SYSCTL_DESCR("Enable loading of bytecode"),
181             NULL, 0, &lua_bytecode_on, 0,
182 	    CTL_CREATE, CTL_EOL);
183 
184         sysctl_createv(&sc->sc_log, 0, &node, NULL,
185             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
186             CTLTYPE_INT, "verbose",
187             SYSCTL_DESCR("Enable verbose output"),
188             NULL, 0, &lua_verbose, 0,
189 	    CTL_CREATE, CTL_EOL);
190 
191         sysctl_createv(&sc->sc_log, 0, &node, NULL,
192             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
193             CTLTYPE_INT, "maxcount",
194             SYSCTL_DESCR("Limit maximum instruction count"),
195             NULL, 0, &lua_max_instr, 0,
196 	    CTL_CREATE, CTL_EOL);
197 
198 	aprint_normal_dev(self, "%s\n", LUA_COPYRIGHT);
199 }
200 
201 static int
202 lua_detach(device_t self, int flags)
203 {
204 	struct lua_softc *sc;
205 	struct lua_state *s;
206 
207 	sc = device_private(self);
208 	pmf_device_deregister(self);
209 
210 	if (sc->sc_log != NULL) {
211 		sysctl_teardown(&sc->sc_log);
212 		sc->sc_log = NULL;
213 	}
214 
215 	/* Traverse the list of states and close them */
216 	while ((s = LIST_FIRST(&lua_states)) != NULL) {
217 		LIST_REMOVE(s, lua_next);
218 		klua_close(s->K);
219 		if (lua_verbose)
220 			device_printf(self, "state %s destroyed\n",
221 			    s->lua_name);
222 		kmem_free(s, sizeof(struct lua_state));
223 	}
224 	mutex_destroy(&sc->sc_lock);
225 	cv_destroy(&sc->sc_inuse_cv);
226 	mutex_destroy(&sc->sc_state_lock);
227 	cv_destroy(&sc->sc_state_cv);
228 	sc_self = NULL;
229 	return 0;
230 }
231 
232 int
233 luaopen(dev_t dev, int flag, int mode, struct lwp *l)
234 {
235 	struct lua_softc *sc;
236 	int error = 0;
237 
238 	if (minor(dev) > 0)
239 		return ENXIO;
240 
241 	sc = device_lookup_private(&lua_cd, minor(dev));
242 	if (sc == NULL)
243 		return ENXIO;
244 
245 	mutex_enter(&sc->sc_lock);
246 	while (sc->sc_inuse == true) {
247 		error = cv_wait_sig(&sc->sc_inuse_cv, &sc->sc_lock);
248 		if (error)
249 			break;
250 	}
251 	if (!error)
252 		sc->sc_inuse = true;
253 	mutex_exit(&sc->sc_lock);
254 
255 	if (error)
256 		return error;
257 	return 0;
258 }
259 
260 int
261 luaclose(dev_t dev, int flag, int mode, struct lwp *l)
262 {
263 	struct lua_softc *sc;
264 
265 	if (minor(dev) > 0)
266 		return ENXIO;
267 	sc = device_lookup_private(&lua_cd, minor(dev));
268 	mutex_enter(&sc->sc_lock);
269 	sc->sc_inuse = false;
270 	cv_signal(&sc->sc_inuse_cv);
271 	mutex_exit(&sc->sc_lock);
272 	return 0;
273 }
274 
275 int
276 luaioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
277 {
278 	struct lua_softc *sc;
279 	struct lua_info *info;
280 	struct lua_create *create;
281 	struct lua_require *require;
282 	struct lua_load *load;
283 	struct lua_state *s;
284 	struct lua_module *m;
285 	kauth_cred_t cred;
286 	struct nameidata nd;
287 	struct pathbuf *pb;
288 	struct vattr va;
289 	struct lua_loadstate ls;
290 	int error, n;
291 	klua_State *K;
292 
293 	sc = device_lookup_private(&lua_cd, minor(dev));
294 	if (!device_is_active(sc->sc_dev))
295 		return EBUSY;
296 
297 	switch (cmd) {
298 	case LUAINFO:
299 		info = data;
300 		if (info->states == NULL) {
301 			info->num_states = 0;
302 			LIST_FOREACH(s, &lua_states, lua_next)
303 				info->num_states++;
304 		} else {
305 			n = 0;
306 			LIST_FOREACH(s, &lua_states, lua_next) {
307 				if (n > info->num_states)
308 					break;
309 				copyoutstr(s->lua_name, info->states[n].name,
310 				    MAX_LUA_NAME, NULL);
311 				copyoutstr(s->lua_desc, info->states[n].desc,
312 				    MAX_LUA_DESC, NULL);
313 				info->states[n].user = s->K->ks_user;
314 				n++;
315 			}
316 			info->num_states = n;
317 		}
318 		break;
319 	case LUACREATE:
320 		create = data;
321 
322 		if (*create->name == '_') {
323 			if (lua_verbose)
324 				device_printf(sc->sc_dev, "names of user "
325 				    "created states must not begin with '_'");
326 				return ENXIO;
327 		}
328 		LIST_FOREACH(s, &lua_states, lua_next)
329 			if (!strcmp(s->lua_name, create->name)) {
330 				if (lua_verbose)
331 					device_printf(sc->sc_dev,
332 					    "state %s exists\n", create->name);
333 				return EBUSY;
334 			}
335 
336 		K = kluaL_newstate(create->name, create->desc, IPL_NONE);
337 		K->ks_user = true;
338 
339 		if (K == NULL)
340 			return ENOMEM;
341 		if (lua_verbose)
342 			device_printf(sc->sc_dev, "state %s created\n",
343 			    create->name);
344 		break;
345 	case LUADESTROY:
346 		create = data;
347 
348 		K = klua_find(create->name);
349 
350 		if (K != NULL && (K->ks_user == true)) {
351 			klua_close(K);
352 			return 0;
353 		}
354 		return EBUSY;
355 	case LUAREQUIRE:	/* 'require' a module in a State */
356 		require = data;
357 		LIST_FOREACH(s, &lua_states, lua_next)
358 			if (!strcmp(s->lua_name, require->state))
359 				LIST_FOREACH(m, &lua_modules, mod_next)
360 					if (!strcmp(m->mod_name,
361 					    require->module)) {
362 					    	if (lua_verbose)
363 						    	device_printf(
364 						    	    sc->sc_dev,
365 					    		    "requiring module "
366 					    		    "%s to state %s\n",
367 					    		    m->mod_name,
368 					    		    s->lua_name);
369 						klua_lock(s->K);
370 					    	m->open(s->K->L);
371 						klua_unlock(s->K);
372 					    	m->refcount++;
373 					    	LIST_INSERT_HEAD(
374 					    	    &s->lua_modules, m,
375 					    	    mod_next);
376 					    	return 0;
377 					}
378 		return ENXIO;
379 	case LUALOAD:
380 		load = data;
381 		if (strrchr(load->path, '/') == NULL)
382 			return ENXIO;
383 
384 		LIST_FOREACH(s, &lua_states, lua_next)
385 			if (!strcmp(s->lua_name, load->state)) {
386 				if (lua_verbose)
387 					device_printf(sc->sc_dev,
388 					    "loading %s into state %s\n",
389 					    load->path, s->lua_name);
390 				cred = kauth_cred_get();
391 				pb = pathbuf_create(load->path);
392 				if (pb == NULL)
393 					return ENOMEM;
394 				NDINIT(&nd, LOOKUP, FOLLOW | NOCHROOT, pb);
395 				pathbuf_destroy(pb);
396 				error = vn_open(&nd, FREAD, 0);
397 				if (error) {
398 					if (lua_verbose)
399 						device_printf(sc->sc_dev,
400 						    "error vn_open %d\n",
401 						    error);
402 					return error;
403 				}
404 				error = VOP_GETATTR(nd.ni_vp, &va,
405 				    kauth_cred_get());
406 				if (error) {
407 					VOP_UNLOCK(nd.ni_vp);
408 					vn_close(nd.ni_vp, FREAD,
409 					    kauth_cred_get());
410 					if (lua_verbose)
411 						device_printf(sc->sc_dev,
412 						    "erro VOP_GETATTR %d\n",
413 						    error);
414 					return error;
415 				}
416 				if (va.va_type != VREG) {
417 					VOP_UNLOCK(nd.ni_vp);
418 					vn_close(nd.ni_vp, FREAD,
419 					    kauth_cred_get());
420 					return EINVAL;
421 				}
422 				ls.vp = nd.ni_vp;
423 				ls.off = 0L;
424 				ls.size = va.va_size;
425 				VOP_UNLOCK(nd.ni_vp);
426 				klua_lock(s->K);
427 				error = lua_load(s->K->L, lua_reader, &ls,
428 				    strrchr(load->path, '/') + 1, "bt");
429 				vn_close(nd.ni_vp, FREAD, cred);
430 				switch (error) {
431 				case 0:	/* no error */
432 					break;
433 				case LUA_ERRSYNTAX:
434 					if (lua_verbose)
435 						device_printf(sc->sc_dev,
436 						    "syntax error\n");
437 					klua_unlock(s->K);
438 					return EINVAL;
439 				case LUA_ERRMEM:
440 					if (lua_verbose)
441 						device_printf(sc->sc_dev,
442 						    "memory error\n");
443 					klua_unlock(s->K);
444 					return ENOMEM;
445 				default:
446 					if (lua_verbose)
447 						device_printf(sc->sc_dev,
448 						    "load error %d: %s\n",
449 						    error,
450 						    lua_tostring(s->K->L, -1));
451 					klua_unlock(s->K);
452 					return EINVAL;
453 				}
454 				if (lua_max_instr > 0)
455 					lua_sethook(s->K->L, lua_maxcount,
456 					    LUA_MASKCOUNT, lua_max_instr);
457 				error = lua_pcall(s->K->L, 0, LUA_MULTRET, 0);
458 				if (error) {
459 					if (lua_verbose) {
460 						device_printf(sc->sc_dev,
461 						    "execution error: %s\n",
462 						    lua_tostring(s->K->L, -1));
463 					}
464 					klua_unlock(s->K);
465 					return EINVAL;
466 				}
467 				klua_unlock(s->K);
468 				return 0;
469 			}
470 		return ENXIO;
471 	}
472 	return 0;
473 }
474 
475 static int
476 lua_require(lua_State *L)
477 {
478 	struct lua_state *s;
479 	struct lua_module *m, *md;
480 	const char *module;
481 	char name[MAXPATHLEN];
482 
483 	module = lua_tostring(L, -1);
484 	md = NULL;
485 	LIST_FOREACH(m, &lua_modules, mod_next)
486 		if (!strcmp(m->mod_name, module)) {
487 			md = m;
488 			break;
489 		}
490 
491 	if (md == NULL && lua_autoload_on && strchr(module, '/') == NULL) {
492 		snprintf(name, sizeof name, "lua%s", module);
493 		if (lua_verbose)
494 			device_printf(sc_self, "autoload %s\n", name);
495 		module_autoload(name, MODULE_CLASS_MISC);
496 		LIST_FOREACH(m, &lua_modules, mod_next)
497 			if (!strcmp(m->mod_name, module)) {
498 				md = m;
499 				break;
500 			}
501 	}
502 
503 	if (md != NULL)
504 		LIST_FOREACH(s, &lua_states, lua_next)
505 			if (s->K->L == L) {
506 				if (lua_verbose)
507 					device_printf(sc_self,
508 					    "require module %s\n",
509 					    md->mod_name);
510 				md->open(L);
511 				md->refcount++;
512 				LIST_INSERT_HEAD(&s->lua_modules, md, mod_next);
513 				return 1;
514 			}
515 
516 	lua_pushstring(L, "module not found");
517 	return lua_error(L);
518 }
519 
520 typedef struct {
521 	size_t size;
522 } __packed alloc_header_t;
523 
524 static void *
525 lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
526 {
527 	void *nptr = NULL;
528 
529 	const size_t hdr_size = sizeof(alloc_header_t);
530 	alloc_header_t *hdr = (alloc_header_t *) ((char *) ptr - hdr_size);
531 
532 	if (nsize == 0) { /* freeing */
533 		if (ptr != NULL)
534 			kmem_intr_free(hdr, hdr->size);
535 	} else if (ptr != NULL && nsize <= hdr->size - hdr_size) /* shrinking */
536 		return ptr; /* don't need to reallocate */
537 	else { /* creating or expanding */
538 		km_flag_t sleep = cpu_intr_p() || cpu_softintr_p() ?
539 			KM_NOSLEEP : KM_SLEEP;
540 
541 		size_t alloc_size = nsize + hdr_size;
542 		alloc_header_t *nhdr = kmem_intr_alloc(alloc_size, sleep);
543 		if (nhdr == NULL) /* failed to allocate */
544 			return NULL;
545 
546 		nhdr->size = alloc_size;
547 		nptr = (void *) ((char *) nhdr + hdr_size);
548 
549 		if (ptr != NULL) { /* expanding */
550 			memcpy(nptr, ptr, osize);
551 			kmem_intr_free(hdr, hdr->size);
552 		}
553 	}
554 	return nptr;
555 }
556 
557 static const char *
558 lua_reader(lua_State *L, void *data, size_t *size)
559 {
560 	struct lua_loadstate *ls;
561 	static char buf[1024];
562 	size_t rsiz;
563 
564 	ls = data;
565 	if (ls->size < sizeof(buf))
566 		rsiz = ls->size;
567 	else
568 		rsiz = sizeof(buf);
569 	vn_rdwr(UIO_READ, ls->vp, buf, rsiz, ls->off, UIO_SYSSPACE,
570 	    0, curlwp->l_cred, NULL, curlwp);
571 	if (ls->off == 0L && lua_bytecode_on == false && buf[0] == 0x1b) {
572 		*size = 0L;
573 		lua_pushstring(L, "loading of bytecode is not allowed");
574 		lua_error(L);
575 		return NULL;
576 	} else {
577 		*size = rsiz;
578 		ls->off += *size;
579 		ls->size -= *size;
580 	}
581 	return buf;
582 }
583 
584 static void
585 lua_maxcount(lua_State *L, lua_Debug *d)
586 {
587 	lua_pushstring(L, "maximum instruction count exceeded");
588 	lua_error(L);
589 }
590 
591 int
592 klua_mod_register(const char *name, lua_CFunction open)
593 {
594 	struct lua_module *m;
595 
596 	LIST_FOREACH(m, &lua_modules, mod_next)
597 		if (!strcmp(m->mod_name, name))
598 			return EBUSY;
599 	m = kmem_zalloc(sizeof(struct lua_module), KM_SLEEP);
600 	strlcpy(m->mod_name, name, LUA_MAX_MODNAME);
601 	m->open = open;
602 	m->refcount = 0;
603 	LIST_INSERT_HEAD(&lua_modules, m, mod_next);
604 	if (lua_verbose)
605 		device_printf(sc_self, "registered lua module %s\n", name);
606 	return 0;
607 }
608 
609 int
610 klua_mod_unregister(const char *name)
611 {
612 	struct lua_module *m;
613 
614 	LIST_FOREACH(m, &lua_modules, mod_next)
615 		if (!strcmp(m->mod_name, name)) {
616 			if (m->refcount == 0) {
617 				LIST_REMOVE(m, mod_next);
618 				kmem_free(m, sizeof(struct lua_module));
619 				if (lua_verbose)
620 					device_printf(sc_self,
621 					    "unregistered lua module %s\n",
622 					    name);
623 				return 0;
624 			} else
625 				return EBUSY;
626 		}
627 	return 0;
628 }
629 
630 klua_State *
631 klua_newstate(lua_Alloc f, void *ud, const char *name, const char *desc,
632 		int ipl)
633 {
634 	klua_State *K;
635 	struct lua_state *s;
636 	struct lua_softc *sc;
637 	int error = 0;
638 
639 	s = kmem_zalloc(sizeof(struct lua_state), KM_SLEEP);
640 	sc = device_private(sc_self);
641 	mutex_enter(&sc->sc_state_lock);
642 	while (sc->sc_state == true) {
643 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
644 		if (error)
645 			break;
646 	}
647 	if (!error)
648 		sc->sc_state = true;
649 	mutex_exit(&sc->sc_state_lock);
650 
651 	if (error)
652 		return NULL;
653 
654 	K = kmem_zalloc(sizeof(klua_State), KM_SLEEP);
655 	K->L = lua_newstate(f, ud);
656 	K->ks_user = false;
657 	if (K->L == NULL) {
658 		kmem_free(K, sizeof(klua_State));
659 		K = NULL;
660 		goto finish;
661 	}
662 
663 	strlcpy(s->lua_name, name, MAX_LUA_NAME);
664 	strlcpy(s->lua_desc, desc, MAX_LUA_DESC);
665 	s->K = K;
666 
667 	if (lua_require_on || lua_autoload_on) {
668 		lua_pushcfunction(K->L, lua_require);
669 		lua_setglobal(K->L, "require");
670 	}
671 	LIST_INSERT_HEAD(&lua_states, s, lua_next);
672 
673 	mutex_init(&K->ks_lock, MUTEX_DEFAULT, ipl);
674 
675 finish:
676 	mutex_enter(&sc->sc_state_lock);
677 	sc->sc_state = false;
678 	cv_signal(&sc->sc_state_cv);
679 	mutex_exit(&sc->sc_state_lock);
680 	return K;
681 }
682 
683 inline klua_State *
684 kluaL_newstate(const char *name, const char *desc, int ipl)
685 {
686 	return klua_newstate(lua_alloc, NULL, name, desc, ipl);
687 }
688 
689 void
690 klua_close(klua_State *K)
691 {
692 	struct lua_state *s;
693 	struct lua_softc *sc;
694 	struct lua_module *m;
695 	int error = 0;
696 
697 	lua_getglobal(K->L, "onClose");
698 	if (lua_isfunction(K->L, -1))
699 		lua_pcall(K->L, -1, 0, 0);
700 
701 	sc = device_private(sc_self);
702 	mutex_enter(&sc->sc_state_lock);
703 	while (sc->sc_state == true) {
704 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
705 		if (error)
706 			break;
707 	}
708 	if (!error)
709 		sc->sc_state = true;
710 	mutex_exit(&sc->sc_state_lock);
711 
712 	if (error)
713 		return;		/* Nothing we can do... */
714 
715 	LIST_FOREACH(s, &lua_states, lua_next)
716 		if (s->K == K) {
717 			LIST_REMOVE(s, lua_next);
718 			LIST_FOREACH(m, &s->lua_modules, mod_next)
719 				m->refcount--;
720 			kmem_free(s, sizeof(struct lua_state));
721 		}
722 
723 	lua_close(K->L);
724 	mutex_destroy(&K->ks_lock);
725 	kmem_free(K, sizeof(klua_State));
726 
727 	mutex_enter(&sc->sc_state_lock);
728 	sc->sc_state = false;
729 	cv_signal(&sc->sc_state_cv);
730 	mutex_exit(&sc->sc_state_lock);
731 }
732 
733 static klua_State *
734 klua_find(const char *name)
735 {
736 	struct lua_state *s;
737 	struct lua_softc *sc;
738 	klua_State *K;
739 	int error = 0;
740 
741 	K = NULL;
742 	sc = device_private(sc_self);
743 	mutex_enter(&sc->sc_state_lock);
744 	while (sc->sc_state == true) {
745 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
746 		if (error)
747 			break;
748 	}
749 	if (!error)
750 		sc->sc_state = true;
751 	mutex_exit(&sc->sc_state_lock);
752 
753 	if (error)
754 		return NULL;
755 
756 	LIST_FOREACH(s, &lua_states, lua_next)
757 		if (!strcmp(s->lua_name, name)) {
758 			K = s->K;
759 			break;
760 		}
761 
762 	mutex_enter(&sc->sc_state_lock);
763 	sc->sc_state = false;
764 	cv_signal(&sc->sc_state_cv);
765 	mutex_exit(&sc->sc_state_lock);
766 	return K;
767 }
768 
769 inline void
770 klua_lock(klua_State *K)
771 {
772 	mutex_enter(&K->ks_lock);
773 }
774 
775 inline void
776 klua_unlock(klua_State *K)
777 {
778 	mutex_exit(&K->ks_lock);
779 }
780 
781 MODULE(MODULE_CLASS_MISC, lua, NULL);
782 
783 #ifdef _MODULE
784 static const struct cfiattrdata luabus_iattrdata = {
785 	"luabus", 0, { { NULL, NULL, 0 },}
786 };
787 static const struct cfiattrdata *const lua_attrs[] = {
788 	&luabus_iattrdata, NULL
789 };
790 CFDRIVER_DECL(lua, DV_DULL, lua_attrs);
791 extern struct cfattach lua_ca;
792 static int lualoc[] = {
793 	-1,
794 	-1,
795 	-1
796 };
797 static struct cfdata lua_cfdata[] = {
798 	{
799 		.cf_name = "lua",
800 		.cf_atname = "lua",
801 		.cf_unit = 0,
802 		.cf_fstate = FSTATE_STAR,
803 		.cf_loc = lualoc,
804 		.cf_flags = 0,
805 		.cf_pspec = NULL,
806 	},
807 	{ NULL, NULL, 0, FSTATE_NOTFOUND, NULL, 0, NULL }
808 };
809 #endif
810 
811 static int
812 lua_modcmd(modcmd_t cmd, void *opaque)
813 {
814 #ifdef _MODULE
815 	devmajor_t cmajor, bmajor;
816 	int error = 0;
817 
818 	cmajor = bmajor = NODEVMAJOR;
819 #endif
820 	switch (cmd) {
821 	case MODULE_CMD_INIT:
822 #ifdef _MODULE
823 		error = config_cfdriver_attach(&lua_cd);
824 		if (error)
825 			return error;
826 
827 		error = config_cfattach_attach(lua_cd.cd_name,
828 		    &lua_ca);
829 		if (error) {
830 			config_cfdriver_detach(&lua_cd);
831 			aprint_error("%s: unable to register cfattach\n",
832 			    lua_cd.cd_name);
833 			return error;
834 		}
835 		error = config_cfdata_attach(lua_cfdata, 1);
836 		if (error) {
837 			config_cfattach_detach(lua_cd.cd_name,
838 			    &lua_ca);
839 			config_cfdriver_detach(&lua_cd);
840 			aprint_error("%s: unable to register cfdata\n",
841 			    lua_cd.cd_name);
842 			return error;
843 		}
844 		error = devsw_attach(lua_cd.cd_name, NULL, &bmajor,
845 		    &lua_cdevsw, &cmajor);
846 		if (error) {
847 			aprint_error("%s: unable to register devsw\n",
848 			    lua_cd.cd_name);
849 			config_cfattach_detach(lua_cd.cd_name, &lua_ca);
850 			config_cfdriver_detach(&lua_cd);
851 			return error;
852 		}
853 		config_attach_pseudo(lua_cfdata);
854 #endif
855 		return 0;
856 	case MODULE_CMD_FINI:
857 #ifdef _MODULE
858 		error = config_cfdata_detach(lua_cfdata);
859 		if (error)
860 			return error;
861 
862 		config_cfattach_detach(lua_cd.cd_name, &lua_ca);
863 		config_cfdriver_detach(&lua_cd);
864 		devsw_detach(NULL, &lua_cdevsw);
865 #endif
866 		return 0;
867 	case MODULE_CMD_AUTOUNLOAD:
868 		/* no auto-unload */
869 		return EBUSY;
870 	default:
871 		return ENOTTY;
872 	}
873 }
874