xref: /netbsd-src/sys/modules/lua/lua.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7)
1 /*	$NetBSD: lua.c,v 1.15 2014/11/30 19:15:03 lneto Exp $ */
2 
3 /*
4  * Copyright (c) 2014 by Lourival Vieira Neto <lneto@NetBSD.org>.
5  * Copyright (c) 2011 - 2014 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 						luaL_requiref(
371 							s->K->L,
372 							m->mod_name,
373 							m->open,
374 							1);
375 						klua_unlock(s->K);
376 					    	m->refcount++;
377 					    	LIST_INSERT_HEAD(
378 					    	    &s->lua_modules, m,
379 					    	    mod_next);
380 					    	return 0;
381 					}
382 		return ENXIO;
383 	case LUALOAD:
384 		load = data;
385 		if (strrchr(load->path, '/') == NULL)
386 			return ENXIO;
387 
388 		LIST_FOREACH(s, &lua_states, lua_next)
389 			if (!strcmp(s->lua_name, load->state)) {
390 				if (lua_verbose)
391 					device_printf(sc->sc_dev,
392 					    "loading %s into state %s\n",
393 					    load->path, s->lua_name);
394 				cred = kauth_cred_get();
395 				pb = pathbuf_create(load->path);
396 				if (pb == NULL)
397 					return ENOMEM;
398 				NDINIT(&nd, LOOKUP, FOLLOW | NOCHROOT, pb);
399 				pathbuf_destroy(pb);
400 				error = vn_open(&nd, FREAD, 0);
401 				if (error) {
402 					if (lua_verbose)
403 						device_printf(sc->sc_dev,
404 						    "error vn_open %d\n",
405 						    error);
406 					return error;
407 				}
408 				error = VOP_GETATTR(nd.ni_vp, &va,
409 				    kauth_cred_get());
410 				if (error) {
411 					VOP_UNLOCK(nd.ni_vp);
412 					vn_close(nd.ni_vp, FREAD,
413 					    kauth_cred_get());
414 					if (lua_verbose)
415 						device_printf(sc->sc_dev,
416 						    "erro VOP_GETATTR %d\n",
417 						    error);
418 					return error;
419 				}
420 				if (va.va_type != VREG) {
421 					VOP_UNLOCK(nd.ni_vp);
422 					vn_close(nd.ni_vp, FREAD,
423 					    kauth_cred_get());
424 					return EINVAL;
425 				}
426 				ls.vp = nd.ni_vp;
427 				ls.off = 0L;
428 				ls.size = va.va_size;
429 				VOP_UNLOCK(nd.ni_vp);
430 				klua_lock(s->K);
431 				error = lua_load(s->K->L, lua_reader, &ls,
432 				    strrchr(load->path, '/') + 1, "bt");
433 				vn_close(nd.ni_vp, FREAD, cred);
434 				switch (error) {
435 				case 0:	/* no error */
436 					break;
437 				case LUA_ERRSYNTAX:
438 					if (lua_verbose)
439 						device_printf(sc->sc_dev,
440 						    "syntax error\n");
441 					klua_unlock(s->K);
442 					return EINVAL;
443 				case LUA_ERRMEM:
444 					if (lua_verbose)
445 						device_printf(sc->sc_dev,
446 						    "memory error\n");
447 					klua_unlock(s->K);
448 					return ENOMEM;
449 				default:
450 					if (lua_verbose)
451 						device_printf(sc->sc_dev,
452 						    "load error %d: %s\n",
453 						    error,
454 						    lua_tostring(s->K->L, -1));
455 					klua_unlock(s->K);
456 					return EINVAL;
457 				}
458 				if (lua_max_instr > 0)
459 					lua_sethook(s->K->L, lua_maxcount,
460 					    LUA_MASKCOUNT, lua_max_instr);
461 				error = lua_pcall(s->K->L, 0, LUA_MULTRET, 0);
462 				if (error) {
463 					if (lua_verbose) {
464 						device_printf(sc->sc_dev,
465 						    "execution error: %s\n",
466 						    lua_tostring(s->K->L, -1));
467 					}
468 					klua_unlock(s->K);
469 					return EINVAL;
470 				}
471 				klua_unlock(s->K);
472 				return 0;
473 			}
474 		return ENXIO;
475 	}
476 	return 0;
477 }
478 
479 static int
480 lua_require(lua_State *L)
481 {
482 	struct lua_state *s;
483 	struct lua_module *m, *md;
484 	const char *module;
485 	char name[MAXPATHLEN];
486 
487 	module = lua_tostring(L, -1);
488 	md = NULL;
489 	LIST_FOREACH(m, &lua_modules, mod_next)
490 		if (!strcmp(m->mod_name, module)) {
491 			md = m;
492 			break;
493 		}
494 
495 	if (md == NULL && lua_autoload_on && strchr(module, '/') == NULL) {
496 		snprintf(name, sizeof name, "lua%s", module);
497 		if (lua_verbose)
498 			device_printf(sc_self, "autoload %s\n", name);
499 		module_autoload(name, MODULE_CLASS_MISC);
500 		LIST_FOREACH(m, &lua_modules, mod_next)
501 			if (!strcmp(m->mod_name, module)) {
502 				md = m;
503 				break;
504 			}
505 	}
506 
507 	if (md != NULL)
508 		LIST_FOREACH(s, &lua_states, lua_next)
509 			if (s->K->L == L) {
510 				if (lua_verbose)
511 					device_printf(sc_self,
512 					    "require module %s\n",
513 					    md->mod_name);
514 				luaL_requiref(L, md->mod_name, md->open, 0);
515 
516 				md->refcount++;
517 				LIST_INSERT_HEAD(&s->lua_modules, md, mod_next);
518 				return 1;
519 			}
520 
521 	lua_pushstring(L, "module not found");
522 	return lua_error(L);
523 }
524 
525 typedef struct {
526 	size_t size;
527 } __packed alloc_header_t;
528 
529 static void *
530 lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
531 {
532 	void *nptr = NULL;
533 
534 	const size_t hdr_size = sizeof(alloc_header_t);
535 	alloc_header_t *hdr = (alloc_header_t *) ((char *) ptr - hdr_size);
536 
537 	if (nsize == 0) { /* freeing */
538 		if (ptr != NULL)
539 			kmem_intr_free(hdr, hdr->size);
540 	} else if (ptr != NULL && nsize <= hdr->size - hdr_size) /* shrinking */
541 		return ptr; /* don't need to reallocate */
542 	else { /* creating or expanding */
543 		km_flag_t sleep = cpu_intr_p() || cpu_softintr_p() ?
544 			KM_NOSLEEP : KM_SLEEP;
545 
546 		size_t alloc_size = nsize + hdr_size;
547 		alloc_header_t *nhdr = kmem_intr_alloc(alloc_size, sleep);
548 		if (nhdr == NULL) /* failed to allocate */
549 			return NULL;
550 
551 		nhdr->size = alloc_size;
552 		nptr = (void *) ((char *) nhdr + hdr_size);
553 
554 		if (ptr != NULL) { /* expanding */
555 			memcpy(nptr, ptr, osize);
556 			kmem_intr_free(hdr, hdr->size);
557 		}
558 	}
559 	return nptr;
560 }
561 
562 static const char *
563 lua_reader(lua_State *L, void *data, size_t *size)
564 {
565 	struct lua_loadstate *ls;
566 	static char buf[1024];
567 	size_t rsiz;
568 
569 	ls = data;
570 	if (ls->size < sizeof(buf))
571 		rsiz = ls->size;
572 	else
573 		rsiz = sizeof(buf);
574 	vn_rdwr(UIO_READ, ls->vp, buf, rsiz, ls->off, UIO_SYSSPACE,
575 	    0, curlwp->l_cred, NULL, curlwp);
576 	if (ls->off == 0L && lua_bytecode_on == false && buf[0] == 0x1b) {
577 		*size = 0L;
578 		lua_pushstring(L, "loading of bytecode is not allowed");
579 		lua_error(L);
580 		return NULL;
581 	} else {
582 		*size = rsiz;
583 		ls->off += *size;
584 		ls->size -= *size;
585 	}
586 	return buf;
587 }
588 
589 static void
590 lua_maxcount(lua_State *L, lua_Debug *d)
591 {
592 	lua_pushstring(L, "maximum instruction count exceeded");
593 	lua_error(L);
594 }
595 
596 int
597 klua_mod_register(const char *name, lua_CFunction open)
598 {
599 	struct lua_module *m;
600 
601 	LIST_FOREACH(m, &lua_modules, mod_next)
602 		if (!strcmp(m->mod_name, name))
603 			return EBUSY;
604 	m = kmem_zalloc(sizeof(struct lua_module), KM_SLEEP);
605 	strlcpy(m->mod_name, name, LUA_MAX_MODNAME);
606 	m->open = open;
607 	m->refcount = 0;
608 	LIST_INSERT_HEAD(&lua_modules, m, mod_next);
609 	if (lua_verbose)
610 		device_printf(sc_self, "registered lua module %s\n", name);
611 	return 0;
612 }
613 
614 int
615 klua_mod_unregister(const char *name)
616 {
617 	struct lua_module *m;
618 
619 	LIST_FOREACH(m, &lua_modules, mod_next)
620 		if (!strcmp(m->mod_name, name)) {
621 			if (m->refcount == 0) {
622 				LIST_REMOVE(m, mod_next);
623 				kmem_free(m, sizeof(struct lua_module));
624 				if (lua_verbose)
625 					device_printf(sc_self,
626 					    "unregistered lua module %s\n",
627 					    name);
628 				return 0;
629 			} else
630 				return EBUSY;
631 		}
632 	return 0;
633 }
634 
635 klua_State *
636 klua_newstate(lua_Alloc f, void *ud, const char *name, const char *desc,
637     int ipl)
638 {
639 	klua_State *K;
640 	struct lua_state *s;
641 	struct lua_softc *sc;
642 	int error = 0;
643 
644 	s = kmem_zalloc(sizeof(struct lua_state), KM_SLEEP);
645 	sc = device_private(sc_self);
646 	mutex_enter(&sc->sc_state_lock);
647 	while (sc->sc_state == true) {
648 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
649 		if (error)
650 			break;
651 	}
652 	if (!error)
653 		sc->sc_state = true;
654 	mutex_exit(&sc->sc_state_lock);
655 
656 	if (error)
657 		return NULL;
658 
659 	K = kmem_zalloc(sizeof(klua_State), KM_SLEEP);
660 	K->L = lua_newstate(f, ud);
661 	K->ks_user = false;
662 	if (K->L == NULL) {
663 		kmem_free(K, sizeof(klua_State));
664 		K = NULL;
665 		goto finish;
666 	}
667 
668 	strlcpy(s->lua_name, name, MAX_LUA_NAME);
669 	strlcpy(s->lua_desc, desc, MAX_LUA_DESC);
670 	s->K = K;
671 
672 	if (lua_require_on || lua_autoload_on) {
673 		lua_pushcfunction(K->L, lua_require);
674 		lua_setglobal(K->L, "require");
675 	}
676 	LIST_INSERT_HEAD(&lua_states, s, lua_next);
677 
678 	mutex_init(&K->ks_lock, MUTEX_DEFAULT, ipl);
679 
680 finish:
681 	mutex_enter(&sc->sc_state_lock);
682 	sc->sc_state = false;
683 	cv_signal(&sc->sc_state_cv);
684 	mutex_exit(&sc->sc_state_lock);
685 	return K;
686 }
687 
688 inline klua_State *
689 kluaL_newstate(const char *name, const char *desc, int ipl)
690 {
691 	return klua_newstate(lua_alloc, NULL, name, desc, ipl);
692 }
693 
694 void
695 klua_close(klua_State *K)
696 {
697 	struct lua_state *s;
698 	struct lua_softc *sc;
699 	struct lua_module *m;
700 	int error = 0;
701 
702 	/* XXX consider registering a handler instead of a fixed name. */
703 	lua_getglobal(K->L, "onClose");
704 	if (lua_isfunction(K->L, -1))
705 		lua_pcall(K->L, -1, 0, 0);
706 
707 	sc = device_private(sc_self);
708 	mutex_enter(&sc->sc_state_lock);
709 	while (sc->sc_state == true) {
710 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
711 		if (error)
712 			break;
713 	}
714 	if (!error)
715 		sc->sc_state = true;
716 	mutex_exit(&sc->sc_state_lock);
717 
718 	if (error)
719 		return;		/* Nothing we can do... */
720 
721 	LIST_FOREACH(s, &lua_states, lua_next)
722 		if (s->K == K) {
723 			LIST_REMOVE(s, lua_next);
724 			LIST_FOREACH(m, &s->lua_modules, mod_next)
725 				m->refcount--;
726 			kmem_free(s, sizeof(struct lua_state));
727 		}
728 
729 	lua_close(K->L);
730 	mutex_destroy(&K->ks_lock);
731 	kmem_free(K, sizeof(klua_State));
732 
733 	mutex_enter(&sc->sc_state_lock);
734 	sc->sc_state = false;
735 	cv_signal(&sc->sc_state_cv);
736 	mutex_exit(&sc->sc_state_lock);
737 }
738 
739 static klua_State *
740 klua_find(const char *name)
741 {
742 	struct lua_state *s;
743 	struct lua_softc *sc;
744 	klua_State *K;
745 	int error = 0;
746 
747 	K = NULL;
748 	sc = device_private(sc_self);
749 	mutex_enter(&sc->sc_state_lock);
750 	while (sc->sc_state == true) {
751 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
752 		if (error)
753 			break;
754 	}
755 	if (!error)
756 		sc->sc_state = true;
757 	mutex_exit(&sc->sc_state_lock);
758 
759 	if (error)
760 		return NULL;
761 
762 	LIST_FOREACH(s, &lua_states, lua_next)
763 		if (!strcmp(s->lua_name, name)) {
764 			K = s->K;
765 			break;
766 		}
767 
768 	mutex_enter(&sc->sc_state_lock);
769 	sc->sc_state = false;
770 	cv_signal(&sc->sc_state_cv);
771 	mutex_exit(&sc->sc_state_lock);
772 	return K;
773 }
774 
775 inline void
776 klua_lock(klua_State *K)
777 {
778 	mutex_enter(&K->ks_lock);
779 }
780 
781 inline void
782 klua_unlock(klua_State *K)
783 {
784 	mutex_exit(&K->ks_lock);
785 }
786 
787 MODULE(MODULE_CLASS_MISC, lua, NULL);
788 
789 #ifdef _MODULE
790 static const struct cfiattrdata luabus_iattrdata = {
791 	"luabus", 0, { { NULL, NULL, 0 },}
792 };
793 
794 static const struct cfiattrdata *const lua_attrs[] = {
795 	&luabus_iattrdata, NULL
796 };
797 
798 CFDRIVER_DECL(lua, DV_DULL, lua_attrs);
799 extern struct cfattach lua_ca;
800 static int lualoc[] = {
801 	-1,
802 	-1,
803 	-1
804 };
805 
806 static struct cfdata lua_cfdata[] = {
807 	{
808 		.cf_name = "lua",
809 		.cf_atname = "lua",
810 		.cf_unit = 0,
811 		.cf_fstate = FSTATE_STAR,
812 		.cf_loc = lualoc,
813 		.cf_flags = 0,
814 		.cf_pspec = NULL,
815 	},
816 	{ NULL, NULL, 0, FSTATE_NOTFOUND, NULL, 0, NULL }
817 };
818 #endif
819 
820 static int
821 lua_modcmd(modcmd_t cmd, void *opaque)
822 {
823 #ifdef _MODULE
824 	devmajor_t cmajor, bmajor;
825 	int error = 0;
826 
827 	cmajor = bmajor = NODEVMAJOR;
828 #endif
829 	switch (cmd) {
830 	case MODULE_CMD_INIT:
831 #ifdef _MODULE
832 		error = config_cfdriver_attach(&lua_cd);
833 		if (error)
834 			return error;
835 
836 		error = config_cfattach_attach(lua_cd.cd_name,
837 		    &lua_ca);
838 		if (error) {
839 			config_cfdriver_detach(&lua_cd);
840 			aprint_error("%s: unable to register cfattach\n",
841 			    lua_cd.cd_name);
842 			return error;
843 		}
844 		error = config_cfdata_attach(lua_cfdata, 1);
845 		if (error) {
846 			config_cfattach_detach(lua_cd.cd_name,
847 			    &lua_ca);
848 			config_cfdriver_detach(&lua_cd);
849 			aprint_error("%s: unable to register cfdata\n",
850 			    lua_cd.cd_name);
851 			return error;
852 		}
853 		error = devsw_attach(lua_cd.cd_name, NULL, &bmajor,
854 		    &lua_cdevsw, &cmajor);
855 		if (error) {
856 			aprint_error("%s: unable to register devsw\n",
857 			    lua_cd.cd_name);
858 			config_cfattach_detach(lua_cd.cd_name, &lua_ca);
859 			config_cfdriver_detach(&lua_cd);
860 			return error;
861 		}
862 		config_attach_pseudo(lua_cfdata);
863 #endif
864 		return 0;
865 	case MODULE_CMD_FINI:
866 #ifdef _MODULE
867 		error = config_cfdata_detach(lua_cfdata);
868 		if (error)
869 			return error;
870 
871 		config_cfattach_detach(lua_cd.cd_name, &lua_ca);
872 		config_cfdriver_detach(&lua_cd);
873 		devsw_detach(NULL, &lua_cdevsw);
874 #endif
875 		return 0;
876 	case MODULE_CMD_AUTOUNLOAD:
877 		/* no auto-unload */
878 		return EBUSY;
879 	default:
880 		return ENOTTY;
881 	}
882 }
883