xref: /netbsd-src/sys/modules/lua/lua.c (revision e89934bbf778a6d6d6894877c4da59d0c7835b0f)
1 /*	$NetBSD: lua.c,v 1.19 2017/01/20 12:25:07 maya 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 	if (!pmf_device_register(self, NULL, NULL))
145 		aprint_error_dev(self, "couldn't establish power handler\n");
146 
147 	/* Sysctl to provide some control over behaviour */
148         sysctl_createv(&sc->sc_log, 0, NULL, &node,
149             CTLFLAG_OWNDESC,
150             CTLTYPE_NODE, "lua",
151             SYSCTL_DESCR("Lua options"),
152             NULL, 0, NULL, 0,
153             CTL_KERN, CTL_CREATE, CTL_EOL);
154 
155         if (node == NULL) {
156 		aprint_error(": can't create sysctl node\n");
157                 return;
158 	}
159 
160 	/*
161 	 * XXX Some of the sysctl values must not be changed after the
162 	 * securelevel has been raised.
163 	 */
164         sysctl_createv(&sc->sc_log, 0, &node, NULL,
165             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
166             CTLTYPE_BOOL, "require",
167             SYSCTL_DESCR("Enable the require command"),
168             NULL, 0, &lua_require_on, 0,
169 	    CTL_CREATE, CTL_EOL);
170 
171         sysctl_createv(&sc->sc_log, 0, &node, NULL,
172             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
173             CTLTYPE_BOOL, "autoload",
174             SYSCTL_DESCR("Enable automatic load of modules"),
175             NULL, 0, &lua_autoload_on, 0,
176 	    CTL_CREATE, CTL_EOL);
177 
178         sysctl_createv(&sc->sc_log, 0, &node, NULL,
179             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
180             CTLTYPE_BOOL, "bytecode",
181             SYSCTL_DESCR("Enable loading of bytecode"),
182             NULL, 0, &lua_bytecode_on, 0,
183 	    CTL_CREATE, CTL_EOL);
184 
185         sysctl_createv(&sc->sc_log, 0, &node, NULL,
186             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
187             CTLTYPE_INT, "verbose",
188             SYSCTL_DESCR("Enable verbose output"),
189             NULL, 0, &lua_verbose, 0,
190 	    CTL_CREATE, CTL_EOL);
191 
192         sysctl_createv(&sc->sc_log, 0, &node, NULL,
193             CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
194             CTLTYPE_INT, "maxcount",
195             SYSCTL_DESCR("Limit maximum instruction count"),
196             NULL, 0, &lua_max_instr, 0,
197 	    CTL_CREATE, CTL_EOL);
198 
199 	aprint_normal_dev(self, "%s\n", LUA_COPYRIGHT);
200 }
201 
202 static int
203 lua_detach(device_t self, int flags)
204 {
205 	struct lua_softc *sc;
206 	struct lua_state *s;
207 
208 	sc = device_private(self);
209 	pmf_device_deregister(self);
210 
211 	if (sc->sc_log != NULL) {
212 		sysctl_teardown(&sc->sc_log);
213 		sc->sc_log = NULL;
214 	}
215 
216 	/* Traverse the list of states and close them */
217 	while ((s = LIST_FIRST(&lua_states)) != NULL) {
218 		LIST_REMOVE(s, lua_next);
219 		klua_close(s->K);
220 		if (lua_verbose)
221 			device_printf(self, "state %s destroyed\n",
222 			    s->lua_name);
223 		kmem_free(s, sizeof(struct lua_state));
224 	}
225 	mutex_destroy(&sc->sc_lock);
226 	cv_destroy(&sc->sc_inuse_cv);
227 	mutex_destroy(&sc->sc_state_lock);
228 	cv_destroy(&sc->sc_state_cv);
229 	sc_self = NULL;
230 	return 0;
231 }
232 
233 int
234 luaopen(dev_t dev, int flag, int mode, struct lwp *l)
235 {
236 	struct lua_softc *sc;
237 	int error = 0;
238 
239 	if (minor(dev) > 0)
240 		return ENXIO;
241 
242 	sc = device_lookup_private(&lua_cd, minor(dev));
243 	if (sc == NULL)
244 		return ENXIO;
245 
246 	mutex_enter(&sc->sc_lock);
247 	while (sc->sc_inuse == true) {
248 		error = cv_wait_sig(&sc->sc_inuse_cv, &sc->sc_lock);
249 		if (error)
250 			break;
251 	}
252 	if (!error)
253 		sc->sc_inuse = true;
254 	mutex_exit(&sc->sc_lock);
255 
256 	if (error)
257 		return error;
258 	return 0;
259 }
260 
261 int
262 luaclose(dev_t dev, int flag, int mode, struct lwp *l)
263 {
264 	struct lua_softc *sc;
265 
266 	if (minor(dev) > 0)
267 		return ENXIO;
268 	sc = device_lookup_private(&lua_cd, minor(dev));
269 	mutex_enter(&sc->sc_lock);
270 	sc->sc_inuse = false;
271 	cv_signal(&sc->sc_inuse_cv);
272 	mutex_exit(&sc->sc_lock);
273 	return 0;
274 }
275 
276 int
277 luaioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
278 {
279 	struct lua_softc *sc;
280 	struct lua_info *info;
281 	struct lua_create *create;
282 	struct lua_require *require;
283 	struct lua_load *load;
284 	struct lua_state *s;
285 	struct lua_module *m;
286 	kauth_cred_t cred;
287 	struct nameidata nd;
288 	struct pathbuf *pb;
289 	struct vattr va;
290 	struct lua_loadstate ls;
291 	int error, n;
292 	klua_State *K;
293 
294 	sc = device_lookup_private(&lua_cd, minor(dev));
295 	if (!device_is_active(sc->sc_dev))
296 		return EBUSY;
297 
298 	switch (cmd) {
299 	case LUAINFO:
300 		info = data;
301 		if (info->states == NULL) {
302 			info->num_states = 0;
303 			LIST_FOREACH(s, &lua_states, lua_next)
304 				info->num_states++;
305 		} else {
306 			n = 0;
307 			LIST_FOREACH(s, &lua_states, lua_next) {
308 				if (n > info->num_states)
309 					break;
310 				copyoutstr(s->lua_name, info->states[n].name,
311 				    MAX_LUA_NAME, NULL);
312 				copyoutstr(s->lua_desc, info->states[n].desc,
313 				    MAX_LUA_DESC, NULL);
314 				info->states[n].user = s->K->ks_user;
315 				n++;
316 			}
317 			info->num_states = n;
318 		}
319 		break;
320 	case LUACREATE:
321 		create = data;
322 
323 		if (*create->name == '_') {
324 			if (lua_verbose)
325 				device_printf(sc->sc_dev, "names of user "
326 				    "created states must not begin with '_'");
327 				return ENXIO;
328 		}
329 		LIST_FOREACH(s, &lua_states, lua_next)
330 			if (!strcmp(s->lua_name, create->name)) {
331 				if (lua_verbose)
332 					device_printf(sc->sc_dev,
333 					    "state %s exists\n", create->name);
334 				return EBUSY;
335 			}
336 
337 		K = kluaL_newstate(create->name, create->desc, IPL_NONE);
338 		K->ks_user = true;
339 
340 		if (K == NULL)
341 			return ENOMEM;
342 		if (lua_verbose)
343 			device_printf(sc->sc_dev, "state %s created\n",
344 			    create->name);
345 		break;
346 	case LUADESTROY:
347 		create = data;
348 
349 		K = klua_find(create->name);
350 
351 		if (K != NULL && (K->ks_user == true)) {
352 			klua_close(K);
353 			return 0;
354 		}
355 		return EBUSY;
356 	case LUAREQUIRE:	/* 'require' a module in a State */
357 		require = data;
358 		LIST_FOREACH(s, &lua_states, lua_next)
359 			if (!strcmp(s->lua_name, require->state)) {
360 				LIST_FOREACH(m, &s->lua_modules, mod_next)
361 					if (!strcmp(m->mod_name, require->module))
362 						return ENXIO;
363 				LIST_FOREACH(m, &lua_modules, mod_next)
364 					if (!strcmp(m->mod_name,
365 					    require->module)) {
366 					    	if (lua_verbose)
367 						    	device_printf(
368 						    	    sc->sc_dev,
369 					    		    "requiring module "
370 					    		    "%s to state %s\n",
371 					    		    m->mod_name,
372 					    		    s->lua_name);
373 						klua_lock(s->K);
374 						luaL_requiref(
375 							s->K->L,
376 							m->mod_name,
377 							m->open,
378 							1);
379 						klua_unlock(s->K);
380 					    	m->refcount++;
381 					    	LIST_INSERT_HEAD(
382 					    	    &s->lua_modules, m,
383 					    	    mod_next);
384 					    	return 0;
385 					}
386 			}
387 		return ENXIO;
388 	case LUALOAD:
389 		load = data;
390 		if (strrchr(load->path, '/') == NULL)
391 			return ENXIO;
392 
393 		LIST_FOREACH(s, &lua_states, lua_next)
394 			if (!strcmp(s->lua_name, load->state)) {
395 				if (lua_verbose)
396 					device_printf(sc->sc_dev,
397 					    "loading %s into state %s\n",
398 					    load->path, s->lua_name);
399 				cred = kauth_cred_get();
400 				pb = pathbuf_create(load->path);
401 				if (pb == NULL)
402 					return ENOMEM;
403 				NDINIT(&nd, LOOKUP, FOLLOW | NOCHROOT, pb);
404 				pathbuf_destroy(pb);
405 				error = vn_open(&nd, FREAD, 0);
406 				if (error) {
407 					if (lua_verbose)
408 						device_printf(sc->sc_dev,
409 						    "error vn_open %d\n",
410 						    error);
411 					return error;
412 				}
413 				error = VOP_GETATTR(nd.ni_vp, &va,
414 				    kauth_cred_get());
415 				if (error) {
416 					VOP_UNLOCK(nd.ni_vp);
417 					vn_close(nd.ni_vp, FREAD,
418 					    kauth_cred_get());
419 					if (lua_verbose)
420 						device_printf(sc->sc_dev,
421 						    "erro VOP_GETATTR %d\n",
422 						    error);
423 					return error;
424 				}
425 				if (va.va_type != VREG) {
426 					VOP_UNLOCK(nd.ni_vp);
427 					vn_close(nd.ni_vp, FREAD,
428 					    kauth_cred_get());
429 					return EINVAL;
430 				}
431 				ls.vp = nd.ni_vp;
432 				ls.off = 0L;
433 				ls.size = va.va_size;
434 				VOP_UNLOCK(nd.ni_vp);
435 				klua_lock(s->K);
436 				error = lua_load(s->K->L, lua_reader, &ls,
437 				    strrchr(load->path, '/') + 1, "bt");
438 				vn_close(nd.ni_vp, FREAD, cred);
439 				switch (error) {
440 				case 0:	/* no error */
441 					break;
442 				case LUA_ERRSYNTAX:
443 					if (lua_verbose)
444 						device_printf(sc->sc_dev,
445 						    "syntax error\n");
446 					klua_unlock(s->K);
447 					return EINVAL;
448 				case LUA_ERRMEM:
449 					if (lua_verbose)
450 						device_printf(sc->sc_dev,
451 						    "memory error\n");
452 					klua_unlock(s->K);
453 					return ENOMEM;
454 				default:
455 					if (lua_verbose)
456 						device_printf(sc->sc_dev,
457 						    "load error %d: %s\n",
458 						    error,
459 						    lua_tostring(s->K->L, -1));
460 					klua_unlock(s->K);
461 					return EINVAL;
462 				}
463 				if (lua_max_instr > 0)
464 					lua_sethook(s->K->L, lua_maxcount,
465 					    LUA_MASKCOUNT, lua_max_instr);
466 				error = lua_pcall(s->K->L, 0, LUA_MULTRET, 0);
467 				if (error) {
468 					if (lua_verbose) {
469 						device_printf(sc->sc_dev,
470 						    "execution error: %s\n",
471 						    lua_tostring(s->K->L, -1));
472 					}
473 					klua_unlock(s->K);
474 					return EINVAL;
475 				}
476 				klua_unlock(s->K);
477 				return 0;
478 			}
479 		return ENXIO;
480 	}
481 	return 0;
482 }
483 
484 static int
485 lua_require(lua_State *L)
486 {
487 	struct lua_state *s;
488 	struct lua_module *m, *md;
489 	const char *module;
490 	char name[MAXPATHLEN];
491 
492 	module = lua_tostring(L, -1);
493 	md = NULL;
494 	LIST_FOREACH(m, &lua_modules, mod_next)
495 		if (!strcmp(m->mod_name, module)) {
496 			md = m;
497 			break;
498 		}
499 
500 	if (md == NULL && lua_autoload_on && strchr(module, '/') == NULL) {
501 		snprintf(name, sizeof name, "lua%s", module);
502 		if (lua_verbose)
503 			device_printf(sc_self, "autoload %s\n", name);
504 		module_autoload(name, MODULE_CLASS_MISC);
505 		LIST_FOREACH(m, &lua_modules, mod_next)
506 			if (!strcmp(m->mod_name, module)) {
507 				md = m;
508 				break;
509 			}
510 	}
511 
512 	if (md != NULL)
513 		LIST_FOREACH(s, &lua_states, lua_next)
514 			if (s->K->L == L) {
515 				if (lua_verbose)
516 					device_printf(sc_self,
517 					    "require module %s\n",
518 					    md->mod_name);
519 				luaL_requiref(L, md->mod_name, md->open, 0);
520 
521 				md->refcount++;
522 				LIST_INSERT_HEAD(&s->lua_modules, md, mod_next);
523 				return 1;
524 			}
525 
526 	lua_pushstring(L, "module not found");
527 	return lua_error(L);
528 }
529 
530 typedef struct {
531 	size_t size;
532 } __packed alloc_header_t;
533 
534 static void *
535 lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
536 {
537 	void *nptr = NULL;
538 
539 	const size_t hdr_size = sizeof(alloc_header_t);
540 	alloc_header_t *hdr = (alloc_header_t *) ((char *) ptr - hdr_size);
541 
542 	if (nsize == 0) { /* freeing */
543 		if (ptr != NULL)
544 			kmem_intr_free(hdr, hdr->size);
545 	} else if (ptr != NULL && nsize <= hdr->size - hdr_size) /* shrinking */
546 		return ptr; /* don't need to reallocate */
547 	else { /* creating or expanding */
548 		km_flag_t sleep = cpu_intr_p() || cpu_softintr_p() ?
549 			KM_NOSLEEP : KM_SLEEP;
550 
551 		size_t alloc_size = nsize + hdr_size;
552 		alloc_header_t *nhdr = kmem_intr_alloc(alloc_size, sleep);
553 		if (nhdr == NULL) /* failed to allocate */
554 			return NULL;
555 
556 		nhdr->size = alloc_size;
557 		nptr = (void *) ((char *) nhdr + hdr_size);
558 
559 		if (ptr != NULL) { /* expanding */
560 			memcpy(nptr, ptr, osize);
561 			kmem_intr_free(hdr, hdr->size);
562 		}
563 	}
564 	return nptr;
565 }
566 
567 static const char *
568 lua_reader(lua_State *L, void *data, size_t *size)
569 {
570 	struct lua_loadstate *ls;
571 	static char buf[1024];
572 	size_t rsiz;
573 
574 	ls = data;
575 	if (ls->size < sizeof(buf))
576 		rsiz = ls->size;
577 	else
578 		rsiz = sizeof(buf);
579 	vn_rdwr(UIO_READ, ls->vp, buf, rsiz, ls->off, UIO_SYSSPACE,
580 	    0, curlwp->l_cred, NULL, curlwp);
581 	if (ls->off == 0L && lua_bytecode_on == false && buf[0] == 0x1b) {
582 		*size = 0L;
583 		lua_pushstring(L, "loading of bytecode is not allowed");
584 		lua_error(L);
585 		return NULL;
586 	} else {
587 		*size = rsiz;
588 		ls->off += *size;
589 		ls->size -= *size;
590 	}
591 	return buf;
592 }
593 
594 static void
595 lua_maxcount(lua_State *L, lua_Debug *d)
596 {
597 	lua_pushstring(L, "maximum instruction count exceeded");
598 	lua_error(L);
599 }
600 
601 int
602 klua_mod_register(const char *name, lua_CFunction open)
603 {
604 	struct lua_module *m;
605 
606 	LIST_FOREACH(m, &lua_modules, mod_next)
607 		if (!strcmp(m->mod_name, name))
608 			return EBUSY;
609 	m = kmem_zalloc(sizeof(struct lua_module), KM_SLEEP);
610 	strlcpy(m->mod_name, name, LUA_MAX_MODNAME);
611 	m->open = open;
612 	m->refcount = 0;
613 	LIST_INSERT_HEAD(&lua_modules, m, mod_next);
614 	if (lua_verbose)
615 		device_printf(sc_self, "registered lua module %s\n", name);
616 	return 0;
617 }
618 
619 int
620 klua_mod_unregister(const char *name)
621 {
622 	struct lua_module *m;
623 
624 	LIST_FOREACH(m, &lua_modules, mod_next)
625 		if (!strcmp(m->mod_name, name)) {
626 			if (m->refcount == 0) {
627 				LIST_REMOVE(m, mod_next);
628 				kmem_free(m, sizeof(struct lua_module));
629 				if (lua_verbose)
630 					device_printf(sc_self,
631 					    "unregistered lua module %s\n",
632 					    name);
633 				return 0;
634 			} else
635 				return EBUSY;
636 		}
637 	return 0;
638 }
639 
640 klua_State *
641 klua_newstate(lua_Alloc f, void *ud, const char *name, const char *desc,
642     int ipl)
643 {
644 	klua_State *K;
645 	struct lua_state *s;
646 	struct lua_softc *sc;
647 	int error = 0;
648 
649 	s = kmem_zalloc(sizeof(struct lua_state), KM_SLEEP);
650 	sc = device_private(sc_self);
651 	mutex_enter(&sc->sc_state_lock);
652 	while (sc->sc_state == true) {
653 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
654 		if (error)
655 			break;
656 	}
657 	if (!error)
658 		sc->sc_state = true;
659 	mutex_exit(&sc->sc_state_lock);
660 
661 	if (error) {
662 		kmem_free(s, sizeof(struct lua_state));
663 		return NULL;
664 	}
665 
666 	K = kmem_zalloc(sizeof(klua_State), KM_SLEEP);
667 	K->L = lua_newstate(f, ud);
668 	K->ks_user = false;
669 	if (K->L == NULL) {
670 		kmem_free(K, sizeof(klua_State));
671 		K = NULL;
672 		goto finish;
673 	}
674 
675 	strlcpy(s->lua_name, name, MAX_LUA_NAME);
676 	strlcpy(s->lua_desc, desc, MAX_LUA_DESC);
677 	s->K = K;
678 
679 	if (lua_require_on || lua_autoload_on) {
680 		lua_pushcfunction(K->L, lua_require);
681 		lua_setglobal(K->L, "require");
682 	}
683 	LIST_INSERT_HEAD(&lua_states, s, lua_next);
684 
685 	mutex_init(&K->ks_lock, MUTEX_DEFAULT, ipl);
686 
687 finish:
688 	mutex_enter(&sc->sc_state_lock);
689 	sc->sc_state = false;
690 	cv_signal(&sc->sc_state_cv);
691 	mutex_exit(&sc->sc_state_lock);
692 	return K;
693 }
694 
695 inline klua_State *
696 kluaL_newstate(const char *name, const char *desc, int ipl)
697 {
698 	return klua_newstate(lua_alloc, NULL, name, desc, ipl);
699 }
700 
701 void
702 klua_close(klua_State *K)
703 {
704 	struct lua_state *s;
705 	struct lua_softc *sc;
706 	struct lua_module *m;
707 	int error = 0;
708 
709 	/* XXX consider registering a handler instead of a fixed name. */
710 	lua_getglobal(K->L, "onClose");
711 	if (lua_isfunction(K->L, -1))
712 		lua_pcall(K->L, -1, 0, 0);
713 
714 	sc = device_private(sc_self);
715 	mutex_enter(&sc->sc_state_lock);
716 	while (sc->sc_state == true) {
717 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
718 		if (error)
719 			break;
720 	}
721 	if (!error)
722 		sc->sc_state = true;
723 	mutex_exit(&sc->sc_state_lock);
724 
725 	if (error)
726 		return;		/* Nothing we can do... */
727 
728 	LIST_FOREACH(s, &lua_states, lua_next)
729 		if (s->K == K) {
730 			LIST_REMOVE(s, lua_next);
731 			LIST_FOREACH(m, &s->lua_modules, mod_next)
732 				m->refcount--;
733 			kmem_free(s, sizeof(struct lua_state));
734 		}
735 
736 	lua_close(K->L);
737 	mutex_destroy(&K->ks_lock);
738 	kmem_free(K, sizeof(klua_State));
739 
740 	mutex_enter(&sc->sc_state_lock);
741 	sc->sc_state = false;
742 	cv_signal(&sc->sc_state_cv);
743 	mutex_exit(&sc->sc_state_lock);
744 }
745 
746 static klua_State *
747 klua_find(const char *name)
748 {
749 	struct lua_state *s;
750 	struct lua_softc *sc;
751 	klua_State *K;
752 	int error = 0;
753 
754 	K = NULL;
755 	sc = device_private(sc_self);
756 	mutex_enter(&sc->sc_state_lock);
757 	while (sc->sc_state == true) {
758 		error = cv_wait_sig(&sc->sc_state_cv, &sc->sc_state_lock);
759 		if (error)
760 			break;
761 	}
762 	if (!error)
763 		sc->sc_state = true;
764 	mutex_exit(&sc->sc_state_lock);
765 
766 	if (error)
767 		return NULL;
768 
769 	LIST_FOREACH(s, &lua_states, lua_next)
770 		if (!strcmp(s->lua_name, name)) {
771 			K = s->K;
772 			break;
773 		}
774 
775 	mutex_enter(&sc->sc_state_lock);
776 	sc->sc_state = false;
777 	cv_signal(&sc->sc_state_cv);
778 	mutex_exit(&sc->sc_state_lock);
779 	return K;
780 }
781 
782 inline void
783 klua_lock(klua_State *K)
784 {
785 	mutex_enter(&K->ks_lock);
786 }
787 
788 inline void
789 klua_unlock(klua_State *K)
790 {
791 	mutex_exit(&K->ks_lock);
792 }
793 
794 MODULE(MODULE_CLASS_MISC, lua, NULL);
795 
796 #ifdef _MODULE
797 static const struct cfiattrdata luabus_iattrdata = {
798 	"luabus", 0, { { NULL, NULL, 0 },}
799 };
800 
801 static const struct cfiattrdata *const lua_attrs[] = {
802 	&luabus_iattrdata, NULL
803 };
804 
805 CFDRIVER_DECL(lua, DV_DULL, lua_attrs);
806 extern struct cfattach lua_ca;
807 static int lualoc[] = {
808 	-1,
809 	-1,
810 	-1
811 };
812 
813 static struct cfdata lua_cfdata[] = {
814 	{
815 		.cf_name = "lua",
816 		.cf_atname = "lua",
817 		.cf_unit = 0,
818 		.cf_fstate = FSTATE_STAR,
819 		.cf_loc = lualoc,
820 		.cf_flags = 0,
821 		.cf_pspec = NULL,
822 	},
823 	{ NULL, NULL, 0, FSTATE_NOTFOUND, NULL, 0, NULL }
824 };
825 #endif
826 
827 static int
828 lua_modcmd(modcmd_t cmd, void *opaque)
829 {
830 #ifdef _MODULE
831 	devmajor_t cmajor, bmajor;
832 	int error = 0;
833 
834 	cmajor = bmajor = NODEVMAJOR;
835 #endif
836 	switch (cmd) {
837 	case MODULE_CMD_INIT:
838 #ifdef _MODULE
839 		error = config_cfdriver_attach(&lua_cd);
840 		if (error)
841 			return error;
842 
843 		error = config_cfattach_attach(lua_cd.cd_name,
844 		    &lua_ca);
845 		if (error) {
846 			config_cfdriver_detach(&lua_cd);
847 			aprint_error("%s: unable to register cfattach\n",
848 			    lua_cd.cd_name);
849 			return error;
850 		}
851 		error = config_cfdata_attach(lua_cfdata, 1);
852 		if (error) {
853 			config_cfattach_detach(lua_cd.cd_name,
854 			    &lua_ca);
855 			config_cfdriver_detach(&lua_cd);
856 			aprint_error("%s: unable to register cfdata\n",
857 			    lua_cd.cd_name);
858 			return error;
859 		}
860 		error = devsw_attach(lua_cd.cd_name, NULL, &bmajor,
861 		    &lua_cdevsw, &cmajor);
862 		if (error) {
863 			aprint_error("%s: unable to register devsw\n",
864 			    lua_cd.cd_name);
865 			config_cfattach_detach(lua_cd.cd_name, &lua_ca);
866 			config_cfdriver_detach(&lua_cd);
867 			return error;
868 		}
869 		config_attach_pseudo(lua_cfdata);
870 #endif
871 		return 0;
872 	case MODULE_CMD_FINI:
873 #ifdef _MODULE
874 		error = config_cfdata_detach(lua_cfdata);
875 		if (error)
876 			return error;
877 
878 		config_cfattach_detach(lua_cd.cd_name, &lua_ca);
879 		config_cfdriver_detach(&lua_cd);
880 		devsw_detach(NULL, &lua_cdevsw);
881 #endif
882 		return 0;
883 	case MODULE_CMD_AUTOUNLOAD:
884 		/* no auto-unload */
885 		return EBUSY;
886 	default:
887 		return ENOTTY;
888 	}
889 }
890