xref: /freebsd/sbin/devd/devd.cc (revision f8ea072a542112d5e0e74a2d6ecf75d967c3054c)
1 /*-
2  * Copyright (c) 2002-2010 M. Warner Losh.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * my_system is a variation on lib/libc/stdlib/system.c:
27  *
28  * Copyright (c) 1988, 1993
29  *	The Regents of the University of California.  All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  * 4. Neither the name of the University nor the names of its contributors
40  *    may be used to endorse or promote products derived from this software
41  *    without specific prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  */
55 
56 /*
57  * DEVD control daemon.
58  */
59 
60 // TODO list:
61 //	o devd.conf and devd man pages need a lot of help:
62 //	  - devd needs to document the unix domain socket
63 //	  - devd.conf needs more details on the supported statements.
64 
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67 
68 #include <sys/param.h>
69 #include <sys/socket.h>
70 #include <sys/stat.h>
71 #include <sys/sysctl.h>
72 #include <sys/types.h>
73 #include <sys/wait.h>
74 #include <sys/un.h>
75 
76 #include <cctype>
77 #include <cerrno>
78 #include <cstdlib>
79 #include <cstdio>
80 #include <csignal>
81 #include <cstring>
82 #include <cstdarg>
83 
84 #include <dirent.h>
85 #include <err.h>
86 #include <fcntl.h>
87 #include <libutil.h>
88 #include <paths.h>
89 #include <poll.h>
90 #include <regex.h>
91 #include <syslog.h>
92 #include <unistd.h>
93 
94 #include <algorithm>
95 #include <map>
96 #include <string>
97 #include <list>
98 #include <vector>
99 
100 #include "devd.h"		/* C compatible definitions */
101 #include "devd.hh"		/* C++ class definitions */
102 
103 #define PIPE "/var/run/devd.pipe"
104 #define CF "/etc/devd.conf"
105 #define SYSCTL "hw.bus.devctl_disable"
106 
107 using namespace std;
108 
109 extern FILE *yyin;
110 extern int lineno;
111 
112 static const char notify = '!';
113 static const char nomatch = '?';
114 static const char attach = '+';
115 static const char detach = '-';
116 
117 static struct pidfh *pfh;
118 
119 int dflag;
120 int nflag;
121 static unsigned total_events = 0;
122 static volatile sig_atomic_t got_siginfo = 0;
123 static volatile sig_atomic_t romeo_must_die = 0;
124 
125 static const char *configfile = CF;
126 
127 static void devdlog(int priority, const char* message, ...);
128 static void event_loop(void);
129 static void usage(void);
130 
131 template <class T> void
132 delete_and_clear(vector<T *> &v)
133 {
134 	typename vector<T *>::const_iterator i;
135 
136 	for (i = v.begin(); i != v.end(); ++i)
137 		delete *i;
138 	v.clear();
139 }
140 
141 config cfg;
142 
143 event_proc::event_proc() : _prio(-1)
144 {
145 	_epsvec.reserve(4);
146 }
147 
148 event_proc::~event_proc()
149 {
150 	delete_and_clear(_epsvec);
151 }
152 
153 void
154 event_proc::add(eps *eps)
155 {
156 	_epsvec.push_back(eps);
157 }
158 
159 bool
160 event_proc::matches(config &c) const
161 {
162 	vector<eps *>::const_iterator i;
163 
164 	for (i = _epsvec.begin(); i != _epsvec.end(); ++i)
165 		if (!(*i)->do_match(c))
166 			return (false);
167 	return (true);
168 }
169 
170 bool
171 event_proc::run(config &c) const
172 {
173 	vector<eps *>::const_iterator i;
174 
175 	for (i = _epsvec.begin(); i != _epsvec.end(); ++i)
176 		if (!(*i)->do_action(c))
177 			return (false);
178 	return (true);
179 }
180 
181 action::action(const char *cmd)
182 	: _cmd(cmd)
183 {
184 	// nothing
185 }
186 
187 action::~action()
188 {
189 	// nothing
190 }
191 
192 static int
193 my_system(const char *command)
194 {
195 	pid_t pid, savedpid;
196 	int pstat;
197 	struct sigaction ign, intact, quitact;
198 	sigset_t newsigblock, oldsigblock;
199 
200 	if (!command)		/* just checking... */
201 		return (1);
202 
203 	/*
204 	 * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
205 	 * existing signal dispositions.
206 	 */
207 	ign.sa_handler = SIG_IGN;
208 	::sigemptyset(&ign.sa_mask);
209 	ign.sa_flags = 0;
210 	::sigaction(SIGINT, &ign, &intact);
211 	::sigaction(SIGQUIT, &ign, &quitact);
212 	::sigemptyset(&newsigblock);
213 	::sigaddset(&newsigblock, SIGCHLD);
214 	::sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
215 	switch (pid = ::fork()) {
216 	case -1:			/* error */
217 		break;
218 	case 0:				/* child */
219 		/*
220 		 * Restore original signal dispositions and exec the command.
221 		 */
222 		::sigaction(SIGINT, &intact, NULL);
223 		::sigaction(SIGQUIT,  &quitact, NULL);
224 		::sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
225 		/*
226 		 * Close the PID file, and all other open descriptors.
227 		 * Inherit std{in,out,err} only.
228 		 */
229 		cfg.close_pidfile();
230 		::closefrom(3);
231 		::execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
232 		::_exit(127);
233 	default:			/* parent */
234 		savedpid = pid;
235 		do {
236 			pid = ::wait4(savedpid, &pstat, 0, (struct rusage *)0);
237 		} while (pid == -1 && errno == EINTR);
238 		break;
239 	}
240 	::sigaction(SIGINT, &intact, NULL);
241 	::sigaction(SIGQUIT,  &quitact, NULL);
242 	::sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
243 	return (pid == -1 ? -1 : pstat);
244 }
245 
246 bool
247 action::do_action(config &c)
248 {
249 	string s = c.expand_string(_cmd.c_str());
250 	devdlog(LOG_NOTICE, "Executing '%s'\n", s.c_str());
251 	my_system(s.c_str());
252 	return (true);
253 }
254 
255 match::match(config &c, const char *var, const char *re) :
256 	_inv(re[0] == '!'),
257 	_var(var),
258 	_re(c.expand_string(_inv ? re + 1 : re, "^", "$"))
259 {
260 	regcomp(&_regex, _re.c_str(), REG_EXTENDED | REG_NOSUB | REG_ICASE);
261 }
262 
263 match::~match()
264 {
265 	regfree(&_regex);
266 }
267 
268 bool
269 match::do_match(config &c)
270 {
271 	const string &value = c.get_variable(_var);
272 	bool retval;
273 
274 	/*
275 	 * This function gets called WAY too often to justify calling syslog()
276 	 * each time, even at LOG_DEBUG.  Because if syslogd isn't running, it
277 	 * can consume excessive amounts of systime inside of connect().  Only
278 	 * log when we're in -d mode.
279 	 */
280 	if (dflag) {
281 		devdlog(LOG_DEBUG, "Testing %s=%s against %s, invert=%d\n",
282 		    _var.c_str(), value.c_str(), _re.c_str(), _inv);
283 	}
284 
285 	retval = (regexec(&_regex, value.c_str(), 0, NULL, 0) == 0);
286 	if (_inv == 1)
287 		retval = (retval == 0) ? 1 : 0;
288 
289 	return (retval);
290 }
291 
292 #include <sys/sockio.h>
293 #include <net/if.h>
294 #include <net/if_media.h>
295 
296 media::media(config &, const char *var, const char *type)
297 	: _var(var), _type(-1)
298 {
299 	static struct ifmedia_description media_types[] = {
300 		{ IFM_ETHER,		"Ethernet" },
301 		{ IFM_TOKEN,		"Tokenring" },
302 		{ IFM_FDDI,		"FDDI" },
303 		{ IFM_IEEE80211,	"802.11" },
304 		{ IFM_ATM,		"ATM" },
305 		{ -1,			"unknown" },
306 		{ 0, NULL },
307 	};
308 	for (int i = 0; media_types[i].ifmt_string != NULL; ++i)
309 		if (strcasecmp(type, media_types[i].ifmt_string) == 0) {
310 			_type = media_types[i].ifmt_word;
311 			break;
312 		}
313 }
314 
315 media::~media()
316 {
317 }
318 
319 bool
320 media::do_match(config &c)
321 {
322 	string value;
323 	struct ifmediareq ifmr;
324 	bool retval;
325 	int s;
326 
327 	// Since we can be called from both a device attach/detach
328 	// context where device-name is defined and what we want,
329 	// as well as from a link status context, where subsystem is
330 	// the name of interest, first try device-name and fall back
331 	// to subsystem if none exists.
332 	value = c.get_variable("device-name");
333 	if (value.empty())
334 		value = c.get_variable("subsystem");
335 	devdlog(LOG_DEBUG, "Testing media type of %s against 0x%x\n",
336 		    value.c_str(), _type);
337 
338 	retval = false;
339 
340 	s = socket(PF_INET, SOCK_DGRAM, 0);
341 	if (s >= 0) {
342 		memset(&ifmr, 0, sizeof(ifmr));
343 		strncpy(ifmr.ifm_name, value.c_str(), sizeof(ifmr.ifm_name));
344 
345 		if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) >= 0 &&
346 		    ifmr.ifm_status & IFM_AVALID) {
347 			devdlog(LOG_DEBUG, "%s has media type 0x%x\n",
348 				    value.c_str(), IFM_TYPE(ifmr.ifm_active));
349 			retval = (IFM_TYPE(ifmr.ifm_active) == _type);
350 		} else if (_type == -1) {
351 			devdlog(LOG_DEBUG, "%s has unknown media type\n",
352 				    value.c_str());
353 			retval = true;
354 		}
355 		close(s);
356 	}
357 
358 	return (retval);
359 }
360 
361 const string var_list::bogus = "_$_$_$_$_B_O_G_U_S_$_$_$_$_";
362 const string var_list::nothing = "";
363 
364 const string &
365 var_list::get_variable(const string &var) const
366 {
367 	map<string, string>::const_iterator i;
368 
369 	i = _vars.find(var);
370 	if (i == _vars.end())
371 		return (var_list::bogus);
372 	return (i->second);
373 }
374 
375 bool
376 var_list::is_set(const string &var) const
377 {
378 	return (_vars.find(var) != _vars.end());
379 }
380 
381 void
382 var_list::set_variable(const string &var, const string &val)
383 {
384 	/*
385 	 * This function gets called WAY too often to justify calling syslog()
386 	 * each time, even at LOG_DEBUG.  Because if syslogd isn't running, it
387 	 * can consume excessive amounts of systime inside of connect().  Only
388 	 * log when we're in -d mode.
389 	 */
390 	if (dflag)
391 		devdlog(LOG_DEBUG, "setting %s=%s\n", var.c_str(), val.c_str());
392 	_vars[var] = val;
393 }
394 
395 void
396 config::reset(void)
397 {
398 	_dir_list.clear();
399 	delete_and_clear(_var_list_table);
400 	delete_and_clear(_attach_list);
401 	delete_and_clear(_detach_list);
402 	delete_and_clear(_nomatch_list);
403 	delete_and_clear(_notify_list);
404 }
405 
406 void
407 config::parse_one_file(const char *fn)
408 {
409 	devdlog(LOG_DEBUG, "Parsing %s\n", fn);
410 	yyin = fopen(fn, "r");
411 	if (yyin == NULL)
412 		err(1, "Cannot open config file %s", fn);
413 	lineno = 1;
414 	if (yyparse() != 0)
415 		errx(1, "Cannot parse %s at line %d", fn, lineno);
416 	fclose(yyin);
417 }
418 
419 void
420 config::parse_files_in_dir(const char *dirname)
421 {
422 	DIR *dirp;
423 	struct dirent *dp;
424 	char path[PATH_MAX];
425 
426 	devdlog(LOG_DEBUG, "Parsing files in %s\n", dirname);
427 	dirp = opendir(dirname);
428 	if (dirp == NULL)
429 		return;
430 	readdir(dirp);		/* Skip . */
431 	readdir(dirp);		/* Skip .. */
432 	while ((dp = readdir(dirp)) != NULL) {
433 		if (strcmp(dp->d_name + dp->d_namlen - 5, ".conf") == 0) {
434 			snprintf(path, sizeof(path), "%s/%s",
435 			    dirname, dp->d_name);
436 			parse_one_file(path);
437 		}
438 	}
439 	closedir(dirp);
440 }
441 
442 class epv_greater {
443 public:
444 	int operator()(event_proc *const&l1, event_proc *const&l2) const
445 	{
446 		return (l1->get_priority() > l2->get_priority());
447 	}
448 };
449 
450 void
451 config::sort_vector(vector<event_proc *> &v)
452 {
453 	stable_sort(v.begin(), v.end(), epv_greater());
454 }
455 
456 void
457 config::parse(void)
458 {
459 	vector<string>::const_iterator i;
460 
461 	parse_one_file(configfile);
462 	for (i = _dir_list.begin(); i != _dir_list.end(); ++i)
463 		parse_files_in_dir((*i).c_str());
464 	sort_vector(_attach_list);
465 	sort_vector(_detach_list);
466 	sort_vector(_nomatch_list);
467 	sort_vector(_notify_list);
468 }
469 
470 void
471 config::open_pidfile()
472 {
473 	pid_t otherpid;
474 
475 	if (_pidfile.empty())
476 		return;
477 	pfh = pidfile_open(_pidfile.c_str(), 0600, &otherpid);
478 	if (pfh == NULL) {
479 		if (errno == EEXIST)
480 			errx(1, "devd already running, pid: %d", (int)otherpid);
481 		warn("cannot open pid file");
482 	}
483 }
484 
485 void
486 config::write_pidfile()
487 {
488 
489 	pidfile_write(pfh);
490 }
491 
492 void
493 config::close_pidfile()
494 {
495 
496 	pidfile_close(pfh);
497 }
498 
499 void
500 config::remove_pidfile()
501 {
502 
503 	pidfile_remove(pfh);
504 }
505 
506 void
507 config::add_attach(int prio, event_proc *p)
508 {
509 	p->set_priority(prio);
510 	_attach_list.push_back(p);
511 }
512 
513 void
514 config::add_detach(int prio, event_proc *p)
515 {
516 	p->set_priority(prio);
517 	_detach_list.push_back(p);
518 }
519 
520 void
521 config::add_directory(const char *dir)
522 {
523 	_dir_list.push_back(string(dir));
524 }
525 
526 void
527 config::add_nomatch(int prio, event_proc *p)
528 {
529 	p->set_priority(prio);
530 	_nomatch_list.push_back(p);
531 }
532 
533 void
534 config::add_notify(int prio, event_proc *p)
535 {
536 	p->set_priority(prio);
537 	_notify_list.push_back(p);
538 }
539 
540 void
541 config::set_pidfile(const char *fn)
542 {
543 	_pidfile = fn;
544 }
545 
546 void
547 config::push_var_table()
548 {
549 	var_list *vl;
550 
551 	vl = new var_list();
552 	_var_list_table.push_back(vl);
553 	devdlog(LOG_DEBUG, "Pushing table\n");
554 }
555 
556 void
557 config::pop_var_table()
558 {
559 	delete _var_list_table.back();
560 	_var_list_table.pop_back();
561 	devdlog(LOG_DEBUG, "Popping table\n");
562 }
563 
564 void
565 config::set_variable(const char *var, const char *val)
566 {
567 	_var_list_table.back()->set_variable(var, val);
568 }
569 
570 const string &
571 config::get_variable(const string &var)
572 {
573 	vector<var_list *>::reverse_iterator i;
574 
575 	for (i = _var_list_table.rbegin(); i != _var_list_table.rend(); ++i) {
576 		if ((*i)->is_set(var))
577 			return ((*i)->get_variable(var));
578 	}
579 	return (var_list::nothing);
580 }
581 
582 bool
583 config::is_id_char(char ch) const
584 {
585 	return (ch != '\0' && (isalpha(ch) || isdigit(ch) || ch == '_' ||
586 	    ch == '-'));
587 }
588 
589 void
590 config::expand_one(const char *&src, string &dst)
591 {
592 	int count;
593 	string buffer;
594 
595 	src++;
596 	// $$ -> $
597 	if (*src == '$') {
598 		dst += *src++;
599 		return;
600 	}
601 
602 	// $(foo) -> $(foo)
603 	// Not sure if I want to support this or not, so for now we just pass
604 	// it through.
605 	if (*src == '(') {
606 		dst += '$';
607 		count = 1;
608 		/* If the string ends before ) is matched , return. */
609 		while (count > 0 && *src) {
610 			if (*src == ')')
611 				count--;
612 			else if (*src == '(')
613 				count++;
614 			dst += *src++;
615 		}
616 		return;
617 	}
618 
619 	// $[^A-Za-z] -> $\1
620 	if (!isalpha(*src)) {
621 		dst += '$';
622 		dst += *src++;
623 		return;
624 	}
625 
626 	// $var -> replace with value
627 	do {
628 		buffer += *src++;
629 	} while (is_id_char(*src));
630 	dst.append(get_variable(buffer));
631 }
632 
633 const string
634 config::expand_string(const char *src, const char *prepend, const char *append)
635 {
636 	const char *var_at;
637 	string dst;
638 
639 	/*
640 	 * 128 bytes is enough for 2427 of 2438 expansions that happen
641 	 * while parsing config files, as tested on 2013-01-30.
642 	 */
643 	dst.reserve(128);
644 
645 	if (prepend != NULL)
646 		dst = prepend;
647 
648 	for (;;) {
649 		var_at = strchr(src, '$');
650 		if (var_at == NULL) {
651 			dst.append(src);
652 			break;
653 		}
654 		dst.append(src, var_at - src);
655 		src = var_at;
656 		expand_one(src, dst);
657 	}
658 
659 	if (append != NULL)
660 		dst.append(append);
661 
662 	return (dst);
663 }
664 
665 bool
666 config::chop_var(char *&buffer, char *&lhs, char *&rhs) const
667 {
668 	char *walker;
669 
670 	if (*buffer == '\0')
671 		return (false);
672 	walker = lhs = buffer;
673 	while (is_id_char(*walker))
674 		walker++;
675 	if (*walker != '=')
676 		return (false);
677 	walker++;		// skip =
678 	if (*walker == '"') {
679 		walker++;	// skip "
680 		rhs = walker;
681 		while (*walker && *walker != '"')
682 			walker++;
683 		if (*walker != '"')
684 			return (false);
685 		rhs[-2] = '\0';
686 		*walker++ = '\0';
687 	} else {
688 		rhs = walker;
689 		while (*walker && !isspace(*walker))
690 			walker++;
691 		if (*walker != '\0')
692 			*walker++ = '\0';
693 		rhs[-1] = '\0';
694 	}
695 	while (isspace(*walker))
696 		walker++;
697 	buffer = walker;
698 	return (true);
699 }
700 
701 
702 char *
703 config::set_vars(char *buffer)
704 {
705 	char *lhs;
706 	char *rhs;
707 
708 	while (1) {
709 		if (!chop_var(buffer, lhs, rhs))
710 			break;
711 		set_variable(lhs, rhs);
712 	}
713 	return (buffer);
714 }
715 
716 void
717 config::find_and_execute(char type)
718 {
719 	vector<event_proc *> *l;
720 	vector<event_proc *>::const_iterator i;
721 	const char *s;
722 
723 	switch (type) {
724 	default:
725 		return;
726 	case notify:
727 		l = &_notify_list;
728 		s = "notify";
729 		break;
730 	case nomatch:
731 		l = &_nomatch_list;
732 		s = "nomatch";
733 		break;
734 	case attach:
735 		l = &_attach_list;
736 		s = "attach";
737 		break;
738 	case detach:
739 		l = &_detach_list;
740 		s = "detach";
741 		break;
742 	}
743 	devdlog(LOG_DEBUG, "Processing %s event\n", s);
744 	for (i = l->begin(); i != l->end(); ++i) {
745 		if ((*i)->matches(*this)) {
746 			(*i)->run(*this);
747 			break;
748 		}
749 	}
750 
751 }
752 
753 
754 static void
755 process_event(char *buffer)
756 {
757 	char type;
758 	char *sp;
759 
760 	sp = buffer + 1;
761 	devdlog(LOG_DEBUG, "Processing event '%s'\n", buffer);
762 	type = *buffer++;
763 	cfg.push_var_table();
764 	// No match doesn't have a device, and the format is a little
765 	// different, so handle it separately.
766 	switch (type) {
767 	case notify:
768 		sp = cfg.set_vars(sp);
769 		break;
770 	case nomatch:
771 		//? at location pnp-info on bus
772 		sp = strchr(sp, ' ');
773 		if (sp == NULL)
774 			return;	/* Can't happen? */
775 		*sp++ = '\0';
776 		while (isspace(*sp))
777 			sp++;
778 		if (strncmp(sp, "at ", 3) == 0)
779 			sp += 3;
780 		sp = cfg.set_vars(sp);
781 		while (isspace(*sp))
782 			sp++;
783 		if (strncmp(sp, "on ", 3) == 0)
784 			cfg.set_variable("bus", sp + 3);
785 		break;
786 	case attach:	/*FALLTHROUGH*/
787 	case detach:
788 		sp = strchr(sp, ' ');
789 		if (sp == NULL)
790 			return;	/* Can't happen? */
791 		*sp++ = '\0';
792 		cfg.set_variable("device-name", buffer);
793 		while (isspace(*sp))
794 			sp++;
795 		if (strncmp(sp, "at ", 3) == 0)
796 			sp += 3;
797 		sp = cfg.set_vars(sp);
798 		while (isspace(*sp))
799 			sp++;
800 		if (strncmp(sp, "on ", 3) == 0)
801 			cfg.set_variable("bus", sp + 3);
802 		break;
803 	}
804 
805 	cfg.find_and_execute(type);
806 	cfg.pop_var_table();
807 }
808 
809 int
810 create_socket(const char *name)
811 {
812 	int fd, slen;
813 	struct sockaddr_un sun;
814 
815 	if ((fd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0)
816 		err(1, "socket");
817 	bzero(&sun, sizeof(sun));
818 	sun.sun_family = AF_UNIX;
819 	strlcpy(sun.sun_path, name, sizeof(sun.sun_path));
820 	slen = SUN_LEN(&sun);
821 	unlink(name);
822 	if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
823 	    	err(1, "fcntl");
824 	if (::bind(fd, (struct sockaddr *) & sun, slen) < 0)
825 		err(1, "bind");
826 	listen(fd, 4);
827 	chown(name, 0, 0);	/* XXX - root.wheel */
828 	chmod(name, 0666);
829 	return (fd);
830 }
831 
832 unsigned int max_clients = 10;	/* Default, can be overriden on cmdline. */
833 unsigned int num_clients;
834 list<int> clients;
835 
836 void
837 notify_clients(const char *data, int len)
838 {
839 	list<int>::iterator i;
840 
841 	/*
842 	 * Deliver the data to all clients.  Throw clients overboard at the
843 	 * first sign of trouble.  This reaps clients who've died or closed
844 	 * their sockets, and also clients who are alive but failing to keep up
845 	 * (or who are maliciously not reading, to consume buffer space in
846 	 * kernel memory or tie up the limited number of available connections).
847 	 */
848 	for (i = clients.begin(); i != clients.end(); ) {
849 		if (write(*i, data, len) != len) {
850 			--num_clients;
851 			close(*i);
852 			i = clients.erase(i);
853 			devdlog(LOG_WARNING, "notify_clients: write() failed; "
854 			    "dropping unresponsive client\n");
855 		} else
856 			++i;
857 	}
858 }
859 
860 void
861 check_clients(void)
862 {
863 	int s;
864 	struct pollfd pfd;
865 	list<int>::iterator i;
866 
867 	/*
868 	 * Check all existing clients to see if any of them have disappeared.
869 	 * Normally we reap clients when we get an error trying to send them an
870 	 * event.  This check eliminates the problem of an ever-growing list of
871 	 * zombie clients because we're never writing to them on a system
872 	 * without frequent device-change activity.
873 	 */
874 	pfd.events = 0;
875 	for (i = clients.begin(); i != clients.end(); ) {
876 		pfd.fd = *i;
877 		s = poll(&pfd, 1, 0);
878 		if ((s < 0 && s != EINTR ) ||
879 		    (s > 0 && (pfd.revents & POLLHUP))) {
880 			--num_clients;
881 			close(*i);
882 			i = clients.erase(i);
883 			devdlog(LOG_NOTICE, "check_clients:  "
884 			    "dropping disconnected client\n");
885 		} else
886 			++i;
887 	}
888 }
889 
890 void
891 new_client(int fd)
892 {
893 	int s;
894 
895 	/*
896 	 * First go reap any zombie clients, then accept the connection, and
897 	 * shut down the read side to stop clients from consuming kernel memory
898 	 * by sending large buffers full of data we'll never read.
899 	 */
900 	check_clients();
901 	s = accept(fd, NULL, NULL);
902 	if (s != -1) {
903 		shutdown(s, SHUT_RD);
904 		clients.push_back(s);
905 		++num_clients;
906 	}
907 }
908 
909 static void
910 event_loop(void)
911 {
912 	int rv;
913 	int fd;
914 	char buffer[DEVCTL_MAXBUF];
915 	int once = 0;
916 	int server_fd, max_fd;
917 	int accepting;
918 	timeval tv;
919 	fd_set fds;
920 
921 	fd = open(PATH_DEVCTL, O_RDONLY | O_CLOEXEC);
922 	if (fd == -1)
923 		err(1, "Can't open devctl device %s", PATH_DEVCTL);
924 	server_fd = create_socket(PIPE);
925 	accepting = 1;
926 	max_fd = max(fd, server_fd) + 1;
927 	while (!romeo_must_die) {
928 		if (!once && !dflag && !nflag) {
929 			// Check to see if we have any events pending.
930 			tv.tv_sec = 0;
931 			tv.tv_usec = 0;
932 			FD_ZERO(&fds);
933 			FD_SET(fd, &fds);
934 			rv = select(fd + 1, &fds, &fds, &fds, &tv);
935 			// No events -> we've processed all pending events
936 			if (rv == 0) {
937 				devdlog(LOG_DEBUG, "Calling daemon\n");
938 				cfg.remove_pidfile();
939 				cfg.open_pidfile();
940 				daemon(0, 0);
941 				cfg.write_pidfile();
942 				once++;
943 			}
944 		}
945 		/*
946 		 * When we've already got the max number of clients, stop
947 		 * accepting new connections (don't put server_fd in the set),
948 		 * shrink the accept() queue to reject connections quickly, and
949 		 * poll the existing clients more often, so that we notice more
950 		 * quickly when any of them disappear to free up client slots.
951 		 */
952 		FD_ZERO(&fds);
953 		FD_SET(fd, &fds);
954 		if (num_clients < max_clients) {
955 			if (!accepting) {
956 				listen(server_fd, max_clients);
957 				accepting = 1;
958 			}
959 			FD_SET(server_fd, &fds);
960 			tv.tv_sec = 60;
961 			tv.tv_usec = 0;
962 		} else {
963 			if (accepting) {
964 				listen(server_fd, 0);
965 				accepting = 0;
966 			}
967 			tv.tv_sec = 2;
968 			tv.tv_usec = 0;
969 		}
970 		rv = select(max_fd, &fds, NULL, NULL, &tv);
971 		if (got_siginfo) {
972 			devdlog(LOG_INFO, "Events received so far=%ld\n",
973 			    total_events);
974 			got_siginfo = 0;
975 		}
976 		if (rv == -1) {
977 			if (errno == EINTR)
978 				continue;
979 			err(1, "select");
980 		} else if (rv == 0)
981 			check_clients();
982 		if (FD_ISSET(fd, &fds)) {
983 			rv = read(fd, buffer, sizeof(buffer) - 1);
984 			if (rv > 0) {
985 				total_events++;
986 				if (rv == sizeof(buffer) - 1) {
987 					devdlog(LOG_WARNING, "Warning: "
988 					    "available event data exceeded "
989 					    "buffer space\n");
990 				}
991 				notify_clients(buffer, rv);
992 				buffer[rv] = '\0';
993 				while (buffer[--rv] == '\n')
994 					buffer[rv] = '\0';
995 				process_event(buffer);
996 			} else if (rv < 0) {
997 				if (errno != EINTR)
998 					break;
999 			} else {
1000 				/* EOF */
1001 				break;
1002 			}
1003 		}
1004 		if (FD_ISSET(server_fd, &fds))
1005 			new_client(server_fd);
1006 	}
1007 	close(fd);
1008 }
1009 
1010 /*
1011  * functions that the parser uses.
1012  */
1013 void
1014 add_attach(int prio, event_proc *p)
1015 {
1016 	cfg.add_attach(prio, p);
1017 }
1018 
1019 void
1020 add_detach(int prio, event_proc *p)
1021 {
1022 	cfg.add_detach(prio, p);
1023 }
1024 
1025 void
1026 add_directory(const char *dir)
1027 {
1028 	cfg.add_directory(dir);
1029 	free(const_cast<char *>(dir));
1030 }
1031 
1032 void
1033 add_nomatch(int prio, event_proc *p)
1034 {
1035 	cfg.add_nomatch(prio, p);
1036 }
1037 
1038 void
1039 add_notify(int prio, event_proc *p)
1040 {
1041 	cfg.add_notify(prio, p);
1042 }
1043 
1044 event_proc *
1045 add_to_event_proc(event_proc *ep, eps *eps)
1046 {
1047 	if (ep == NULL)
1048 		ep = new event_proc();
1049 	ep->add(eps);
1050 	return (ep);
1051 }
1052 
1053 eps *
1054 new_action(const char *cmd)
1055 {
1056 	eps *e = new action(cmd);
1057 	free(const_cast<char *>(cmd));
1058 	return (e);
1059 }
1060 
1061 eps *
1062 new_match(const char *var, const char *re)
1063 {
1064 	eps *e = new match(cfg, var, re);
1065 	free(const_cast<char *>(var));
1066 	free(const_cast<char *>(re));
1067 	return (e);
1068 }
1069 
1070 eps *
1071 new_media(const char *var, const char *re)
1072 {
1073 	eps *e = new media(cfg, var, re);
1074 	free(const_cast<char *>(var));
1075 	free(const_cast<char *>(re));
1076 	return (e);
1077 }
1078 
1079 void
1080 set_pidfile(const char *name)
1081 {
1082 	cfg.set_pidfile(name);
1083 	free(const_cast<char *>(name));
1084 }
1085 
1086 void
1087 set_variable(const char *var, const char *val)
1088 {
1089 	cfg.set_variable(var, val);
1090 	free(const_cast<char *>(var));
1091 	free(const_cast<char *>(val));
1092 }
1093 
1094 
1095 
1096 static void
1097 gensighand(int)
1098 {
1099 	romeo_must_die = 1;
1100 }
1101 
1102 /*
1103  * SIGINFO handler.  Will print useful statistics to the syslog or stderr
1104  * as appropriate
1105  */
1106 static void
1107 siginfohand(int)
1108 {
1109 	got_siginfo = 1;
1110 }
1111 
1112 /*
1113  * Local logging function.  Prints to syslog if we're daemonized; syslog
1114  * otherwise.
1115  */
1116 static void
1117 devdlog(int priority, const char* fmt, ...)
1118 {
1119 	va_list argp;
1120 
1121 	va_start(argp, fmt);
1122 	if (dflag)
1123 		vfprintf(stderr, fmt, argp);
1124 	else
1125 		vsyslog(priority, fmt, argp);
1126 	va_end(argp);
1127 }
1128 
1129 static void
1130 usage()
1131 {
1132 	fprintf(stderr, "usage: %s [-dn] [-l connlimit] [-f file]\n",
1133 	    getprogname());
1134 	exit(1);
1135 }
1136 
1137 static void
1138 check_devd_enabled()
1139 {
1140 	int val = 0;
1141 	size_t len;
1142 
1143 	len = sizeof(val);
1144 	if (sysctlbyname(SYSCTL, &val, &len, NULL, 0) != 0)
1145 		errx(1, "devctl sysctl missing from kernel!");
1146 	if (val) {
1147 		warnx("Setting " SYSCTL " to 0");
1148 		val = 0;
1149 		sysctlbyname(SYSCTL, NULL, NULL, &val, sizeof(val));
1150 	}
1151 }
1152 
1153 /*
1154  * main
1155  */
1156 int
1157 main(int argc, char **argv)
1158 {
1159 	int ch;
1160 
1161 	check_devd_enabled();
1162 	while ((ch = getopt(argc, argv, "df:l:n")) != -1) {
1163 		switch (ch) {
1164 		case 'd':
1165 			dflag++;
1166 			break;
1167 		case 'f':
1168 			configfile = optarg;
1169 			break;
1170 		case 'l':
1171 			max_clients = MAX(1, strtoul(optarg, NULL, 0));
1172 			break;
1173 		case 'n':
1174 			nflag++;
1175 			break;
1176 		default:
1177 			usage();
1178 		}
1179 	}
1180 
1181 	cfg.parse();
1182 	if (!dflag && nflag) {
1183 		cfg.open_pidfile();
1184 		daemon(0, 0);
1185 		cfg.write_pidfile();
1186 	}
1187 	signal(SIGPIPE, SIG_IGN);
1188 	signal(SIGHUP, gensighand);
1189 	signal(SIGINT, gensighand);
1190 	signal(SIGTERM, gensighand);
1191 	signal(SIGINFO, siginfohand);
1192 	event_loop();
1193 	return (0);
1194 }
1195