xref: /dragonfly/sbin/udevd/udevd_monitor.c (revision 7d3e9a5b) 
1 /*
2  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Alex Hornung <ahornung@gmail.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 #include <sys/types.h>
35 #include <sys/device.h>
36 #include <sys/wait.h>
37 #include <sys/socket.h>
38 #include <sys/ioctl.h>
39 #include <sys/poll.h>
40 #include <sys/queue.h>
41 #include <sys/un.h>
42 
43 #include <assert.h>
44 #include <ctype.h>
45 #include <err.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <inttypes.h>
49 #include <libgen.h>
50 #include <pthread.h>
51 #include <regex.h>
52 #include <signal.h>
53 #include <stdarg.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <unistd.h>
59 
60 #include <libprop/proplib.h>
61 #include <sys/udev.h>
62 #include "udevd.h"
63 
64 #define MONITOR_LOCK()		pthread_mutex_lock(&monitor_lock)
65 #define MONITOR_UNLOCK()	pthread_mutex_unlock(&monitor_lock)
66 
67 static int _parse_filter_prop(struct udev_monitor *udm, prop_array_t pa);
68 static int match_filter(struct event_filter *evf, prop_dictionary_t dict);
69 
70 static int WildCaseCmp(const char *w, const char *s);
71 static int wildCaseCmp(const char **mary, int d, const char *w, const char *s);
72 
73 TAILQ_HEAD(udev_monitor_list_head, udev_monitor)	udev_monitor_list;
74 pthread_mutex_t	monitor_lock;
75 
76 
77 void
78 monitor_queue_event(prop_dictionary_t ev_dict)
79 {
80 	struct udev_monitor		*udm;
81 	struct udev_monitor_event	*udm_ev;
82 
83 	MONITOR_LOCK();
84 
85 	TAILQ_FOREACH(udm, &udev_monitor_list, link) {
86 		udm_ev = malloc(sizeof(struct udev_monitor_event));
87 		if (udm_ev == NULL)
88 			continue;
89 
90 		prop_object_retain(ev_dict);
91 		udm_ev->ev_dict = ev_dict;
92 
93 		if (match_event_filter(udm,
94 		    prop_dictionary_get(udm_ev->ev_dict, "evdict")) == 0) {
95 			prop_object_release(ev_dict);
96 			free(udm_ev);
97 			continue;
98 		}
99 
100 		pthread_mutex_lock(&udm->q_lock);
101 		TAILQ_INSERT_TAIL(&udm->ev_queue, udm_ev, link);
102 		pthread_cond_signal(&udm->cond);
103 		pthread_mutex_unlock(&udm->q_lock);
104 	}
105 
106 	MONITOR_UNLOCK();
107 }
108 
109 struct udev_monitor *
110 udev_monitor_init(struct client_info *cli, prop_array_t filters)
111 {
112 	struct udev_monitor *udm;
113 
114 	udm = malloc(sizeof(struct udev_monitor));
115 	if (udm == NULL)
116 		return NULL;
117 
118 	TAILQ_INIT(&udm->ev_queue);
119 	TAILQ_INIT(&udm->ev_filt);
120 
121 	pthread_mutex_init(&udm->q_lock, NULL);
122 	pthread_cond_init(&udm->cond, NULL);
123 	udm->cli = cli;
124 
125 	if (filters != NULL) {
126 		__unused int error = _parse_filter_prop(udm, filters);
127 		/* XXX: ignore error for now */
128 	}
129 
130 	return udm;
131 }
132 
133 void
134 udev_monitor_free(struct udev_monitor *udm)
135 {
136 	struct event_filter	*evf;
137 	struct udev_monitor_event	*udm_ev;
138 
139 	pthread_mutex_lock(&udm->q_lock);
140 
141 	while ((udm_ev = TAILQ_FIRST(&udm->ev_queue)) != NULL) {
142 		prop_object_release(udm_ev->ev_dict);
143 		udm_ev->ev_dict = NULL;
144 		TAILQ_REMOVE(&udm->ev_queue, udm_ev, link);
145 		free(udm_ev);
146 	}
147 
148 	while ((evf = TAILQ_FIRST(&udm->ev_filt)) != NULL) {
149 		TAILQ_REMOVE(&udm->ev_filt, evf, link);
150 		free(evf->key);
151 		if (evf->type == EVENT_FILTER_TYPE_WILDCARD)
152 			free(evf->wildcard_match);
153 		else if (evf->type == EVENT_FILTER_TYPE_REGEX)
154 			regfree(&evf->regex_match);
155 		free(evf);
156 	}
157 
158 	pthread_mutex_unlock(&udm->q_lock);
159 	free(udm);
160 }
161 
162 int
163 client_cmd_monitor(struct client_info *cli, prop_dictionary_t dict)
164 {
165 	prop_array_t	pa;
166 	prop_object_t	po;
167 	struct udev_monitor	*udm;
168 	struct udev_monitor_event	*udm_ev;
169 	struct timespec abstime;
170 	struct pollfd fds[1];
171 	char *xml;
172 	ssize_t r;
173 	int ret, ok, dummy;
174 
175 	pa = NULL;
176 	po = prop_dictionary_get(dict, "filters");
177 	if ((po != NULL) && prop_object_type(po) == PROP_TYPE_ARRAY) {
178 		pa = po;
179 	}
180 
181 	udm = udev_monitor_init(cli, pa);
182 	if (udm == NULL)
183 		return 1;
184 
185 	ok = 1;
186 	fds[0].fd = cli->fd;
187 	fds[0].events = POLLRDNORM;
188 
189 	MONITOR_LOCK();
190 	TAILQ_INSERT_TAIL(&udev_monitor_list, udm, link);
191 	MONITOR_UNLOCK();
192 
193 	pthread_mutex_lock(&udm->q_lock);
194 	while (ok) {
195 		clock_gettime(CLOCK_REALTIME,&abstime);
196 		abstime.tv_sec += 2;
197 		ret = pthread_cond_timedwait(&udm->cond, &udm->q_lock, &abstime);
198 
199 		if (ret == EINVAL) {
200 			syslog(LOG_ERR, "pthread_cond_timedwait error: EINVAL");
201 			goto end_nofree;
202 		}
203 
204 		if ((ret = poll(fds, 1, 0)) > 0) {
205 			ret = recv(fds[0].fd, &dummy, sizeof(dummy), MSG_DONTWAIT);
206 			if ((ret == 0) || ((ret < 0) && (errno != EAGAIN)))
207 				goto end_nofree;
208 		}
209 
210 		udm_ev = TAILQ_FIRST(&udm->ev_queue);
211 		if (udm_ev == NULL)
212 			continue;
213 
214 		assert(udm_ev->ev_dict != NULL);
215 		xml = prop_dictionary_externalize(udm_ev->ev_dict);
216 		if (xml == NULL)
217 			continue;
218 
219 		prop_object_release(udm_ev->ev_dict);
220 		udm_ev->ev_dict = NULL;
221 		TAILQ_REMOVE(&udm->ev_queue, udm_ev, link);
222 		free(udm_ev);
223 
224 		r = send_xml(cli->fd, xml);
225 		if (r <= 0)
226 			goto end;
227 
228 		free(xml);
229 		continue;
230 end:
231 		free(xml);
232 end_nofree:
233 		pthread_mutex_unlock(&udm->q_lock);
234 		close(cli->fd);
235 		ok = 0;
236 
237 	}
238 
239 	MONITOR_LOCK();
240 	TAILQ_REMOVE(&udev_monitor_list, udm, link);
241 	MONITOR_UNLOCK();
242 
243 	udev_monitor_free(udm);
244 
245 	return 1;
246 }
247 
248 static int
249 _parse_filter_prop(struct udev_monitor *udm, prop_array_t pa)
250 {
251 	prop_string_t	ps;
252 	prop_number_t	pn;
253 	prop_object_iterator_t	iter;
254 	prop_dictionary_t	dict;
255 	struct event_filter *evf;
256 	int error;
257 
258 	iter = prop_array_iterator(pa);
259 	if (iter == NULL)
260 		return -1;
261 
262 	while ((dict = prop_object_iterator_next(iter)) != NULL) {
263 		evf = malloc(sizeof(struct event_filter));
264 		bzero(evf, sizeof(struct event_filter));
265 		if (evf == NULL)
266 			goto error_alloc;
267 
268 		ps = prop_dictionary_get(dict, "key");
269 		if (ps == NULL)
270 			goto error_out;
271 		evf->key = prop_string_cstring(ps);
272 		if (evf->key == NULL)
273 			goto error_out;
274 
275 		pn = prop_dictionary_get(dict, "type");
276 		if (pn == NULL)
277 			goto error_out_ps;
278 
279 		ps = prop_dictionary_get(dict, "expr");
280 		if (ps == NULL)
281 			goto error_out_ps;
282 
283 		if (prop_dictionary_get(dict, "negative"))
284 			evf->neg = 1;
285 		else
286 			evf->neg = 0;
287 
288 		evf->type = prop_number_integer_value(pn);
289 		switch (evf->type) {
290 		case EVENT_FILTER_TYPE_WILDCARD:
291 			evf->wildcard_match = prop_string_cstring(ps);
292 			if (evf->wildcard_match == NULL)
293 				goto error_out_ps;
294 			break;
295 
296 		case EVENT_FILTER_TYPE_REGEX:
297 			error = regcomp(&evf->regex_match, prop_string_cstring_nocopy(ps), REG_ICASE | REG_NOSUB);
298 			if (error)
299 				goto error_out_ps;
300 			break;
301 
302 		default:
303 			goto error_out_ps;
304 		}
305 
306 		pthread_mutex_lock(&udm->q_lock);
307 		TAILQ_INSERT_TAIL(&udm->ev_filt, evf, link);
308 		pthread_mutex_unlock(&udm->q_lock);
309 
310 	}
311 
312 	prop_object_iterator_release(iter);
313 	return 0;
314 
315 error_out_ps:
316 	free(evf->key);
317 error_out:
318 	free(evf);
319 error_alloc:
320 	prop_object_iterator_release(iter);
321 	return -1;
322 }
323 
324 /*
325 Event filter format:
326 <array>
327 <dictionary>
328 <key>key</key>
329 <value>(e.g. kptr, devnum, ...)</value>
330 <key>type</key>
331 <value>(e.g. wildcard or regex)</value>
332 <key>expr</key>
333 <value>(regex)</value>
334 </dictionary>
335 ... repeat ...
336 </array>
337 */
338 
339 static int
340 match_filter(struct event_filter *evf, prop_dictionary_t ev_dict)
341 {
342 	prop_object_t		po;
343 	prop_string_t		ps;
344 	prop_number_t		pn;
345 	char *str;
346 	char buf[128];
347 	int ret;
348 
349 	if (ev_dict == NULL)
350 		return 0;
351 
352 	prop_object_retain(ev_dict);
353 
354 	if ((po = prop_dictionary_get(ev_dict, evf->key)) == NULL)
355 		goto no_match;
356 
357 	if (prop_object_type(po) == PROP_TYPE_STRING) {
358 		ps = po;
359 		str = __DECONST(char *, prop_string_cstring_nocopy(ps));
360 	} else if (prop_object_type(po) == PROP_TYPE_NUMBER) {
361 		pn = po;
362 		if (prop_number_unsigned(pn)) {
363 			snprintf(buf, sizeof(buf), "%" PRIu64, prop_number_unsigned_integer_value(pn));
364 		} else {
365 			snprintf(buf, sizeof(buf), "%" PRIi64, prop_number_integer_value(pn));
366 		}
367 		str = buf;
368 	} else {
369 		syslog(LOG_DEBUG, "Unexpected type in match_filter: %d\n", prop_object_type(po));
370 		/* Unexpected type */
371 		goto no_match;
372 	}
373 
374 	switch (evf->type) {
375 	case EVENT_FILTER_TYPE_WILDCARD:
376 		ret = WildCaseCmp(evf->wildcard_match, str);
377 
378 		if (ret != 0)
379 			goto no_match;
380 
381 		break;
382 	case EVENT_FILTER_TYPE_REGEX:
383 		ret = regexec(&evf->regex_match, str, 0, NULL, 0);
384 
385 		if (ret != 0)
386 			goto no_match;
387 		break;
388 	default:
389 		goto no_match;
390 	}
391 
392 	prop_object_release(ev_dict);
393 	return 1;
394 
395 no_match:
396 	prop_object_release(ev_dict);
397 	return 0;
398 }
399 
400 int
401 match_event_filter(struct udev_monitor *udm, prop_dictionary_t ev_dict)
402 {
403 	struct event_filter *evf;
404 
405 	pthread_mutex_lock(&udm->q_lock);
406 
407 	if (TAILQ_EMPTY(&udm->ev_filt))
408 		return 1;
409 
410 	TAILQ_FOREACH(evf, &udm->ev_filt, link) {
411 		if ((evf->neg == 0 && !match_filter(evf, ev_dict)) ||
412 		   (evf->neg == 1 && match_filter(evf, ev_dict))) {
413 			pthread_mutex_unlock(&udm->q_lock);
414 			return 0;
415 		}
416 	}
417 
418 	pthread_mutex_unlock(&udm->q_lock);
419 	return 1;
420 }
421 
422 static int
423 WildCaseCmp(const char *w, const char *s)
424 {
425     int i;
426     int c;
427     int slen = strlen(s);
428     const char **mary;
429 
430     for (i = c = 0; w[i]; ++i) {
431 	if (w[i] == '*')
432 	    ++c;
433     }
434     mary = malloc(sizeof(char *) * (c + 1));
435     if (mary == NULL)
436 	     return -1;
437 
438     for (i = 0; i < c; ++i)
439 	mary[i] = s + slen;
440     i = wildCaseCmp(mary, 0, w, s);
441     free(mary);
442     return(i);
443 }
444 
445 /*
446  * WildCaseCmp() - compare wild string to sane string, case insensitive
447  *
448  *	Returns 0 on success, -1 on failure.
449  */
450 static int
451 wildCaseCmp(const char **mary, int d, const char *w, const char *s)
452 {
453     int i;
454 
455     /*
456      * skip fixed portion
457      */
458     for (;;) {
459 	switch(*w) {
460 	case '*':
461 	    /*
462 	     * optimize terminator
463 	     */
464 	    if (w[1] == 0)
465 		return(0);
466 	    if (w[1] != '?' && w[1] != '*') {
467 		/*
468 		 * optimize * followed by non-wild
469 		 */
470 		for (i = 0; s + i < mary[d]; ++i) {
471 		    if (s[i] == w[1] && wildCaseCmp(mary, d + 1, w + 1, s + i) == 0)
472 			return(0);
473 		}
474 	    } else {
475 		/*
476 		 * less-optimal
477 		 */
478 		for (i = 0; s + i < mary[d]; ++i) {
479 		    if (wildCaseCmp(mary, d + 1, w + 1, s + i) == 0)
480 			return(0);
481 		}
482 	    }
483 	    mary[d] = s;
484 	    return(-1);
485 	case '?':
486 	    if (*s == 0)
487 		return(-1);
488 	    ++w;
489 	    ++s;
490 	    break;
491 	default:
492 	    if (*w != *s) {
493 		if (tolower(*w) != tolower(*s))
494 		    return(-1);
495 	    }
496 	    if (*w == 0)	/* terminator */
497 		return(0);
498 	    ++w;
499 	    ++s;
500 	    break;
501 	}
502     }
503     /* not reached */
504     return(-1);
505 }
506