xref: /freebsd/sbin/devd/devd.cc (revision 76238846ad3e9e271a3d1f792f72beab727fd153)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause AND BSD-2-Clause
3  *
4  * Copyright (c) 2002-2010 M. Warner Losh <imp@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * my_system is a variation on lib/libc/stdlib/system.c:
28  *
29  * Copyright (c) 1988, 1993
30  *	The Regents of the University of California.  All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. Neither the name of the University nor the names of its contributors
41  *    may be used to endorse or promote products derived from this software
42  *    without specific prior written permission.
43  *
44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54  * SUCH DAMAGE.
55  */
56 
57 /*
58  * DEVD control daemon.
59  */
60 
61 // TODO list:
62 //	o devd.conf and devd man pages need a lot of help:
63 //	  - devd needs to document the unix domain socket
64 //	  - devd.conf needs more details on the supported statements.
65 
66 #include <sys/cdefs.h>
67 __FBSDID("$FreeBSD$");
68 
69 #include <sys/param.h>
70 #include <sys/socket.h>
71 #include <sys/stat.h>
72 #include <sys/sysctl.h>
73 #include <sys/types.h>
74 #include <sys/wait.h>
75 #include <sys/un.h>
76 
77 #include <cctype>
78 #include <cerrno>
79 #include <cstdlib>
80 #include <cstdio>
81 #include <csignal>
82 #include <cstring>
83 #include <cstdarg>
84 
85 #include <dirent.h>
86 #include <err.h>
87 #include <fcntl.h>
88 #include <libutil.h>
89 #include <paths.h>
90 #include <poll.h>
91 #include <regex.h>
92 #include <syslog.h>
93 #include <unistd.h>
94 
95 #include <algorithm>
96 #include <map>
97 #include <string>
98 #include <list>
99 #include <stdexcept>
100 #include <vector>
101 
102 #include "devd.h"		/* C compatible definitions */
103 #include "devd.hh"		/* C++ class definitions */
104 
105 #define STREAMPIPE "/var/run/devd.pipe"
106 #define SEQPACKETPIPE "/var/run/devd.seqpacket.pipe"
107 #define CF "/etc/devd.conf"
108 #define SYSCTL "hw.bus.devctl_queue"
109 
110 /*
111  * Since the client socket is nonblocking, we must increase its send buffer to
112  * handle brief event storms.  On FreeBSD, AF_UNIX sockets don't have a receive
113  * buffer, so the client can't increase the buffersize by itself.
114  *
115  * For example, when creating a ZFS pool, devd emits one 165 character
116  * resource.fs.zfs.statechange message for each vdev in the pool.  The kernel
117  * allocates a 4608B mbuf for each message.  Modern technology places a limit of
118  * roughly 450 drives/rack, and it's unlikely that a zpool will ever be larger
119  * than that.
120  *
121  * 450 drives * 165 bytes / drive = 74250B of data in the sockbuf
122  * 450 drives * 4608B / drive = 2073600B of mbufs in the sockbuf
123  *
124  * We can't directly set the sockbuf's mbuf limit, but we can do it indirectly.
125  * The kernel sets it to the minimum of a hard-coded maximum value and sbcc *
126  * kern.ipc.sockbuf_waste_factor, where sbcc is the socket buffer size set by
127  * the user.  The default value of kern.ipc.sockbuf_waste_factor is 8.  If we
128  * set the bufsize to 256k and use the kern.ipc.sockbuf_waste_factor, then the
129  * kernel will set the mbuf limit to 2MB, which is just large enough for 450
130  * drives.  It also happens to be the same as the hardcoded maximum value.
131  */
132 #define CLIENT_BUFSIZE 262144
133 
134 using namespace std;
135 
136 typedef struct client {
137 	int fd;
138 	int socktype;
139 } client_t;
140 
141 extern FILE *yyin;
142 
143 static const char notify = '!';
144 static const char nomatch = '?';
145 static const char attach = '+';
146 static const char detach = '-';
147 
148 static struct pidfh *pfh;
149 
150 static int no_daemon = 0;
151 static int daemonize_quick = 0;
152 static int quiet_mode = 0;
153 static unsigned total_events = 0;
154 static volatile sig_atomic_t got_siginfo = 0;
155 static volatile sig_atomic_t romeo_must_die = 0;
156 
157 static const char *configfile = CF;
158 
159 static void devdlog(int priority, const char* message, ...)
160 	__printflike(2, 3);
161 static void event_loop(void);
162 static void usage(void) __dead2;
163 
164 template <class T> void
165 delete_and_clear(vector<T *> &v)
166 {
167 	typename vector<T *>::const_iterator i;
168 
169 	for (i = v.begin(); i != v.end(); ++i)
170 		delete *i;
171 	v.clear();
172 }
173 
174 static config cfg;
175 
176 static const char *curr_cf = NULL;
177 
178 event_proc::event_proc() : _prio(-1)
179 {
180 	_epsvec.reserve(4);
181 }
182 
183 event_proc::~event_proc()
184 {
185 	delete_and_clear(_epsvec);
186 }
187 
188 void
189 event_proc::add(eps *eps)
190 {
191 	_epsvec.push_back(eps);
192 }
193 
194 bool
195 event_proc::matches(config &c) const
196 {
197 	vector<eps *>::const_iterator i;
198 
199 	for (i = _epsvec.begin(); i != _epsvec.end(); ++i)
200 		if (!(*i)->do_match(c))
201 			return (false);
202 	return (true);
203 }
204 
205 bool
206 event_proc::run(config &c) const
207 {
208 	vector<eps *>::const_iterator i;
209 
210 	for (i = _epsvec.begin(); i != _epsvec.end(); ++i)
211 		if (!(*i)->do_action(c))
212 			return (false);
213 	return (true);
214 }
215 
216 action::action(const char *cmd)
217 	: _cmd(cmd)
218 {
219 	// nothing
220 }
221 
222 action::~action()
223 {
224 	// nothing
225 }
226 
227 static int
228 my_system(const char *command)
229 {
230 	pid_t pid, savedpid;
231 	int pstat;
232 	struct sigaction ign, intact, quitact;
233 	sigset_t newsigblock, oldsigblock;
234 
235 	if (!command)		/* just checking... */
236 		return (1);
237 
238 	/*
239 	 * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
240 	 * existing signal dispositions.
241 	 */
242 	ign.sa_handler = SIG_IGN;
243 	::sigemptyset(&ign.sa_mask);
244 	ign.sa_flags = 0;
245 	::sigaction(SIGINT, &ign, &intact);
246 	::sigaction(SIGQUIT, &ign, &quitact);
247 	::sigemptyset(&newsigblock);
248 	::sigaddset(&newsigblock, SIGCHLD);
249 	::sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
250 	switch (pid = ::fork()) {
251 	case -1:			/* error */
252 		break;
253 	case 0:				/* child */
254 		/*
255 		 * Restore original signal dispositions and exec the command.
256 		 */
257 		::sigaction(SIGINT, &intact, NULL);
258 		::sigaction(SIGQUIT,  &quitact, NULL);
259 		::sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
260 		/*
261 		 * Close the PID file, and all other open descriptors.
262 		 * Inherit std{in,out,err} only.
263 		 */
264 		cfg.close_pidfile();
265 		::closefrom(3);
266 		::execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
267 		::_exit(127);
268 	default:			/* parent */
269 		savedpid = pid;
270 		do {
271 			pid = ::wait4(savedpid, &pstat, 0, (struct rusage *)0);
272 		} while (pid == -1 && errno == EINTR);
273 		break;
274 	}
275 	::sigaction(SIGINT, &intact, NULL);
276 	::sigaction(SIGQUIT,  &quitact, NULL);
277 	::sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
278 	return (pid == -1 ? -1 : pstat);
279 }
280 
281 bool
282 action::do_action(config &c)
283 {
284 	string s = c.expand_string(_cmd.c_str());
285 	devdlog(LOG_INFO, "Executing '%s'\n", s.c_str());
286 	my_system(s.c_str());
287 	return (true);
288 }
289 
290 match::match(config &c, const char *var, const char *re) :
291 	_inv(re[0] == '!'),
292 	_var(var),
293 	_re(c.expand_string(_inv ? re + 1 : re, "^", "$"))
294 {
295 	regcomp(&_regex, _re.c_str(), REG_EXTENDED | REG_NOSUB | REG_ICASE);
296 }
297 
298 match::~match()
299 {
300 	regfree(&_regex);
301 }
302 
303 bool
304 match::do_match(config &c)
305 {
306 	const string &value = c.get_variable(_var);
307 	bool retval;
308 
309 	/*
310 	 * This function gets called WAY too often to justify calling syslog()
311 	 * each time, even at LOG_DEBUG.  Because if syslogd isn't running, it
312 	 * can consume excessive amounts of systime inside of connect().  Only
313 	 * log when we're in -d mode.
314 	 */
315 	if (no_daemon) {
316 		devdlog(LOG_DEBUG, "Testing %s=%s against %s, invert=%d\n",
317 		    _var.c_str(), value.c_str(), _re.c_str(), _inv);
318 	}
319 
320 	retval = (regexec(&_regex, value.c_str(), 0, NULL, 0) == 0);
321 	if (_inv == 1)
322 		retval = (retval == 0) ? 1 : 0;
323 
324 	return (retval);
325 }
326 
327 #include <sys/sockio.h>
328 #include <net/if.h>
329 #include <net/if_media.h>
330 
331 media::media(config &, const char *var, const char *type)
332 	: _var(var), _type(-1)
333 {
334 	static struct ifmedia_description media_types[] = {
335 		{ IFM_ETHER,		"Ethernet" },
336 		{ IFM_IEEE80211,	"802.11" },
337 		{ IFM_ATM,		"ATM" },
338 		{ -1,			"unknown" },
339 		{ 0, NULL },
340 	};
341 	for (int i = 0; media_types[i].ifmt_string != NULL; ++i)
342 		if (strcasecmp(type, media_types[i].ifmt_string) == 0) {
343 			_type = media_types[i].ifmt_word;
344 			break;
345 		}
346 }
347 
348 media::~media()
349 {
350 }
351 
352 bool
353 media::do_match(config &c)
354 {
355 	string value;
356 	struct ifmediareq ifmr;
357 	bool retval;
358 	int s;
359 
360 	// Since we can be called from both a device attach/detach
361 	// context where device-name is defined and what we want,
362 	// as well as from a link status context, where subsystem is
363 	// the name of interest, first try device-name and fall back
364 	// to subsystem if none exists.
365 	value = c.get_variable("device-name");
366 	if (value.empty())
367 		value = c.get_variable("subsystem");
368 	devdlog(LOG_DEBUG, "Testing media type of %s against 0x%x\n",
369 		    value.c_str(), _type);
370 
371 	retval = false;
372 
373 	s = socket(PF_INET, SOCK_DGRAM, 0);
374 	if (s >= 0) {
375 		memset(&ifmr, 0, sizeof(ifmr));
376 		strlcpy(ifmr.ifm_name, value.c_str(), sizeof(ifmr.ifm_name));
377 
378 		if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) >= 0 &&
379 		    ifmr.ifm_status & IFM_AVALID) {
380 			devdlog(LOG_DEBUG, "%s has media type 0x%x\n",
381 				    value.c_str(), IFM_TYPE(ifmr.ifm_active));
382 			retval = (IFM_TYPE(ifmr.ifm_active) == _type);
383 		} else if (_type == -1) {
384 			devdlog(LOG_DEBUG, "%s has unknown media type\n",
385 				    value.c_str());
386 			retval = true;
387 		}
388 		close(s);
389 	}
390 
391 	return (retval);
392 }
393 
394 const string var_list::bogus = "_$_$_$_$_B_O_G_U_S_$_$_$_$_";
395 const string var_list::nothing = "";
396 
397 const string &
398 var_list::get_variable(const string &var) const
399 {
400 	map<string, string>::const_iterator i;
401 
402 	i = _vars.find(var);
403 	if (i == _vars.end())
404 		return (var_list::bogus);
405 	return (i->second);
406 }
407 
408 bool
409 var_list::is_set(const string &var) const
410 {
411 	return (_vars.find(var) != _vars.end());
412 }
413 
414 /** fix_value
415  *
416  * Removes quoted characters that have made it this far. \" are
417  * converted to ". For all other characters, both \ and following
418  * character. So the string 'fre\:\"' is translated to 'fred\:"'.
419  */
420 std::string
421 var_list::fix_value(const std::string &val) const
422 {
423         std::string rv(val);
424         std::string::size_type pos(0);
425 
426         while ((pos = rv.find("\\\"", pos)) != rv.npos) {
427                 rv.erase(pos, 1);
428         }
429         return (rv);
430 }
431 
432 void
433 var_list::set_variable(const string &var, const string &val)
434 {
435 	/*
436 	 * This function gets called WAY too often to justify calling syslog()
437 	 * each time, even at LOG_DEBUG.  Because if syslogd isn't running, it
438 	 * can consume excessive amounts of systime inside of connect().  Only
439 	 * log when we're in -d mode.
440 	 */
441 	_vars[var] = fix_value(val);
442 	if (no_daemon)
443 		devdlog(LOG_DEBUG, "setting %s=%s\n", var.c_str(), val.c_str());
444 }
445 
446 void
447 config::reset(void)
448 {
449 	_dir_list.clear();
450 	delete_and_clear(_var_list_table);
451 	delete_and_clear(_attach_list);
452 	delete_and_clear(_detach_list);
453 	delete_and_clear(_nomatch_list);
454 	delete_and_clear(_notify_list);
455 }
456 
457 /*
458  * Called recursively as new files are included, so current stack of old names
459  * saved in each instance of 'old' on the call stack. Called single threaded
460  * so global varaibles curr_cf and lineno (and all of yacc's parser state)
461  * are safe to access w/o a lock.
462  */
463 void
464 config::parse_one_file(const char *fn)
465 {
466 	const char *old;
467 
468 	devdlog(LOG_DEBUG, "Parsing %s\n", fn);
469 	yyin = fopen(fn, "r");
470 	old = curr_cf;
471 	curr_cf = fn;
472 	if (yyin == NULL)
473 		err(1, "Cannot open config file %s", fn);
474 	lineno = 1;
475 	if (yyparse() != 0)
476 		errx(1, "Cannot parse %s at line %d", fn, lineno);
477 	fclose(yyin);
478 	curr_cf = old;
479 }
480 
481 void
482 config::parse_files_in_dir(const char *dirname)
483 {
484 	DIR *dirp;
485 	struct dirent *dp;
486 	char path[PATH_MAX];
487 
488 	devdlog(LOG_DEBUG, "Parsing files in %s\n", dirname);
489 	dirp = opendir(dirname);
490 	if (dirp == NULL)
491 		return;
492 	readdir(dirp);		/* Skip . */
493 	readdir(dirp);		/* Skip .. */
494 	while ((dp = readdir(dirp)) != NULL) {
495 		if (strcmp(dp->d_name + dp->d_namlen - 5, ".conf") == 0) {
496 			snprintf(path, sizeof(path), "%s/%s",
497 			    dirname, dp->d_name);
498 			parse_one_file(path);
499 		}
500 	}
501 	closedir(dirp);
502 }
503 
504 class epv_greater {
505 public:
506 	int operator()(event_proc *const&l1, event_proc *const&l2) const
507 	{
508 		return (l1->get_priority() > l2->get_priority());
509 	}
510 };
511 
512 void
513 config::sort_vector(vector<event_proc *> &v)
514 {
515 	stable_sort(v.begin(), v.end(), epv_greater());
516 }
517 
518 void
519 config::parse(void)
520 {
521 	vector<string>::const_iterator i;
522 
523 	parse_one_file(configfile);
524 	for (i = _dir_list.begin(); i != _dir_list.end(); ++i)
525 		parse_files_in_dir((*i).c_str());
526 	sort_vector(_attach_list);
527 	sort_vector(_detach_list);
528 	sort_vector(_nomatch_list);
529 	sort_vector(_notify_list);
530 }
531 
532 void
533 config::open_pidfile()
534 {
535 	pid_t otherpid;
536 
537 	if (_pidfile.empty())
538 		return;
539 	pfh = pidfile_open(_pidfile.c_str(), 0600, &otherpid);
540 	if (pfh == NULL) {
541 		if (errno == EEXIST)
542 			errx(1, "devd already running, pid: %d", (int)otherpid);
543 		warn("cannot open pid file");
544 	}
545 }
546 
547 void
548 config::write_pidfile()
549 {
550 
551 	pidfile_write(pfh);
552 }
553 
554 void
555 config::close_pidfile()
556 {
557 
558 	pidfile_close(pfh);
559 }
560 
561 void
562 config::remove_pidfile()
563 {
564 
565 	pidfile_remove(pfh);
566 }
567 
568 void
569 config::add_attach(int prio, event_proc *p)
570 {
571 	p->set_priority(prio);
572 	_attach_list.push_back(p);
573 }
574 
575 void
576 config::add_detach(int prio, event_proc *p)
577 {
578 	p->set_priority(prio);
579 	_detach_list.push_back(p);
580 }
581 
582 void
583 config::add_directory(const char *dir)
584 {
585 	_dir_list.push_back(string(dir));
586 }
587 
588 void
589 config::add_nomatch(int prio, event_proc *p)
590 {
591 	p->set_priority(prio);
592 	_nomatch_list.push_back(p);
593 }
594 
595 void
596 config::add_notify(int prio, event_proc *p)
597 {
598 	p->set_priority(prio);
599 	_notify_list.push_back(p);
600 }
601 
602 void
603 config::set_pidfile(const char *fn)
604 {
605 	_pidfile = fn;
606 }
607 
608 void
609 config::push_var_table()
610 {
611 	var_list *vl;
612 
613 	vl = new var_list();
614 	_var_list_table.push_back(vl);
615 	devdlog(LOG_DEBUG, "Pushing table\n");
616 }
617 
618 void
619 config::pop_var_table()
620 {
621 	delete _var_list_table.back();
622 	_var_list_table.pop_back();
623 	devdlog(LOG_DEBUG, "Popping table\n");
624 }
625 
626 void
627 config::set_variable(const char *var, const char *val)
628 {
629 	_var_list_table.back()->set_variable(var, val);
630 }
631 
632 const string &
633 config::get_variable(const string &var)
634 {
635 	vector<var_list *>::reverse_iterator i;
636 
637 	for (i = _var_list_table.rbegin(); i != _var_list_table.rend(); ++i) {
638 		if ((*i)->is_set(var))
639 			return ((*i)->get_variable(var));
640 	}
641 	return (var_list::nothing);
642 }
643 
644 bool
645 config::is_id_char(char ch) const
646 {
647 	return (ch != '\0' && (isalpha(ch) || isdigit(ch) || ch == '_' ||
648 	    ch == '-'));
649 }
650 
651 string
652 config::shell_quote(const string &s)
653 {
654 	string buffer;
655 	const char *cs, *ce;
656 	char c;
657 
658 	/*
659 	 * Enclose the string in $' ' with escapes for ' and / characters making
660 	 * it one argument and ensuring the shell won't be affected by its
661 	 * usual list of candidates.
662 	 */
663 	buffer.reserve(s.length() * 3 / 2);
664 	buffer += '$';
665 	buffer += '\'';
666 	cs = s.c_str();
667 	ce = cs + strlen(cs);
668 	for (; cs < ce; cs++) {
669 		c = *cs;
670 		if (c == '\'' || c == '\\') {
671 			buffer += '\\';
672 		}
673 		buffer += c;
674 	}
675 	buffer += '\'';
676 
677 	return buffer;
678 }
679 
680 void
681 config::expand_one(const char *&src, string &dst, bool is_shell)
682 {
683 	int count;
684 	string buffer;
685 
686 	src++;
687 	// $$ -> $
688 	if (*src == '$') {
689 		dst += *src++;
690 		return;
691 	}
692 
693 	// $(foo) -> $(foo)
694 	// This is the escape hatch for passing down shell subcommands
695 	if (*src == '(') {
696 		dst += '$';
697 		count = 0;
698 		/* If the string ends before ) is matched , return. */
699 		do {
700 			if (*src == ')')
701 				count--;
702 			else if (*src == '(')
703 				count++;
704 			dst += *src++;
705 		} while (count > 0 && *src);
706 		return;
707 	}
708 
709 	// $[^-A-Za-z_*] -> $\1
710 	if (!isalpha(*src) && *src != '_' && *src != '-' && *src != '*') {
711 		dst += '$';
712 		dst += *src++;
713 		return;
714 	}
715 
716 	// $var -> replace with value
717 	do {
718 		buffer += *src++;
719 	} while (is_id_char(*src));
720 	dst.append(is_shell ? shell_quote(get_variable(buffer)) : get_variable(buffer));
721 }
722 
723 const string
724 config::expand_string(const char *src, const char *prepend, const char *append)
725 {
726 	const char *var_at;
727 	string dst;
728 
729 	/*
730 	 * 128 bytes is enough for 2427 of 2438 expansions that happen
731 	 * while parsing config files, as tested on 2013-01-30.
732 	 */
733 	dst.reserve(128);
734 
735 	if (prepend != NULL)
736 		dst = prepend;
737 
738 	for (;;) {
739 		var_at = strchr(src, '$');
740 		if (var_at == NULL) {
741 			dst.append(src);
742 			break;
743 		}
744 		dst.append(src, var_at - src);
745 		src = var_at;
746 		expand_one(src, dst, prepend == NULL);
747 	}
748 
749 	if (append != NULL)
750 		dst.append(append);
751 
752 	return (dst);
753 }
754 
755 bool
756 config::chop_var(char *&buffer, char *&lhs, char *&rhs) const
757 {
758 	char *walker;
759 
760 	if (*buffer == '\0')
761 		return (false);
762 	walker = lhs = buffer;
763 	while (is_id_char(*walker))
764 		walker++;
765 	if (*walker != '=')
766 		return (false);
767 	walker++;		// skip =
768 	if (*walker == '"') {
769 		walker++;	// skip "
770 		rhs = walker;
771 		while (*walker && *walker != '"') {
772 			// Skip \" ... We leave it in the string and strip the \ later.
773 			// due to the super simplistic parser that we have here.
774 			if (*walker == '\\' && walker[1] == '"')
775 				walker++;
776 			walker++;
777 		}
778 		if (*walker != '"')
779 			return (false);
780 		rhs[-2] = '\0';
781 		*walker++ = '\0';
782 	} else {
783 		rhs = walker;
784 		while (*walker && !isspace(*walker))
785 			walker++;
786 		if (*walker != '\0')
787 			*walker++ = '\0';
788 		rhs[-1] = '\0';
789 	}
790 	while (isspace(*walker))
791 		walker++;
792 	buffer = walker;
793 	return (true);
794 }
795 
796 
797 char *
798 config::set_vars(char *buffer)
799 {
800 	char *lhs;
801 	char *rhs;
802 
803 	while (1) {
804 		if (!chop_var(buffer, lhs, rhs))
805 			break;
806 		set_variable(lhs, rhs);
807 	}
808 	return (buffer);
809 }
810 
811 void
812 config::find_and_execute(char type)
813 {
814 	vector<event_proc *> *l;
815 	vector<event_proc *>::const_iterator i;
816 	const char *s;
817 
818 	switch (type) {
819 	default:
820 		return;
821 	case notify:
822 		l = &_notify_list;
823 		s = "notify";
824 		break;
825 	case nomatch:
826 		l = &_nomatch_list;
827 		s = "nomatch";
828 		break;
829 	case attach:
830 		l = &_attach_list;
831 		s = "attach";
832 		break;
833 	case detach:
834 		l = &_detach_list;
835 		s = "detach";
836 		break;
837 	}
838 	devdlog(LOG_DEBUG, "Processing %s event\n", s);
839 	for (i = l->begin(); i != l->end(); ++i) {
840 		if ((*i)->matches(*this)) {
841 			(*i)->run(*this);
842 			break;
843 		}
844 	}
845 
846 }
847 
848 
849 static void
850 process_event(char *buffer)
851 {
852 	char type;
853 	char *sp;
854 	struct timeval tv;
855 	char *timestr;
856 
857 	sp = buffer + 1;
858 	devdlog(LOG_INFO, "Processing event '%s'\n", buffer);
859 	type = *buffer++;
860 	cfg.push_var_table();
861 	// $* is the entire line
862 	cfg.set_variable("*", buffer - 1);
863 	// $_ is the entire line without the initial character
864 	cfg.set_variable("_", buffer);
865 
866 	// Save the time this happened (as approximated by when we got
867 	// around to processing it).
868 	gettimeofday(&tv, NULL);
869 	asprintf(&timestr, "%jd.%06ld", (uintmax_t)tv.tv_sec, tv.tv_usec);
870 	cfg.set_variable("timestamp", timestr);
871 	free(timestr);
872 
873 	// Match doesn't have a device, and the format is a little
874 	// different, so handle it separately.
875 	switch (type) {
876 	case notify:
877 		//! (k=v)*
878 		sp = cfg.set_vars(sp);
879 		break;
880 	case nomatch:
881 		//? at location pnp-info on bus
882 		sp = strchr(sp, ' ');
883 		if (sp == NULL)
884 			return;	/* Can't happen? */
885 		*sp++ = '\0';
886 		while (isspace(*sp))
887 			sp++;
888 		if (strncmp(sp, "at ", 3) == 0)
889 			sp += 3;
890 		sp = cfg.set_vars(sp);
891 		while (isspace(*sp))
892 			sp++;
893 		if (strncmp(sp, "on ", 3) == 0)
894 			cfg.set_variable("bus", sp + 3);
895 		break;
896 	case attach:	/*FALLTHROUGH*/
897 	case detach:
898 		sp = strchr(sp, ' ');
899 		if (sp == NULL)
900 			return;	/* Can't happen? */
901 		*sp++ = '\0';
902 		cfg.set_variable("device-name", buffer);
903 		while (isspace(*sp))
904 			sp++;
905 		if (strncmp(sp, "at ", 3) == 0)
906 			sp += 3;
907 		sp = cfg.set_vars(sp);
908 		while (isspace(*sp))
909 			sp++;
910 		if (strncmp(sp, "on ", 3) == 0)
911 			cfg.set_variable("bus", sp + 3);
912 		break;
913 	}
914 
915 	cfg.find_and_execute(type);
916 	cfg.pop_var_table();
917 }
918 
919 static int
920 create_socket(const char *name, int socktype)
921 {
922 	int fd, slen;
923 	struct sockaddr_un sun;
924 
925 	if ((fd = socket(PF_LOCAL, socktype, 0)) < 0)
926 		err(1, "socket");
927 	bzero(&sun, sizeof(sun));
928 	sun.sun_family = AF_UNIX;
929 	strlcpy(sun.sun_path, name, sizeof(sun.sun_path));
930 	slen = SUN_LEN(&sun);
931 	unlink(name);
932 	if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
933 	    	err(1, "fcntl");
934 	if (::bind(fd, (struct sockaddr *) & sun, slen) < 0)
935 		err(1, "bind");
936 	listen(fd, 4);
937 	if (chown(name, 0, 0))	/* XXX - root.wheel */
938 		err(1, "chown");
939 	if (chmod(name, 0666))
940 		err(1, "chmod");
941 	return (fd);
942 }
943 
944 static unsigned int max_clients = 10;	/* Default, can be overridden on cmdline. */
945 static unsigned int num_clients;
946 
947 static list<client_t> clients;
948 
949 static void
950 notify_clients(const char *data, int len)
951 {
952 	list<client_t>::iterator i;
953 
954 	/*
955 	 * Deliver the data to all clients.  Throw clients overboard at the
956 	 * first sign of trouble.  This reaps clients who've died or closed
957 	 * their sockets, and also clients who are alive but failing to keep up
958 	 * (or who are maliciously not reading, to consume buffer space in
959 	 * kernel memory or tie up the limited number of available connections).
960 	 */
961 	for (i = clients.begin(); i != clients.end(); ) {
962 		int flags;
963 		if (i->socktype == SOCK_SEQPACKET)
964 			flags = MSG_EOR;
965 		else
966 			flags = 0;
967 
968 		if (send(i->fd, data, len, flags) != len) {
969 			--num_clients;
970 			close(i->fd);
971 			i = clients.erase(i);
972 			devdlog(LOG_WARNING, "notify_clients: send() failed; "
973 			    "dropping unresponsive client\n");
974 		} else
975 			++i;
976 	}
977 }
978 
979 static void
980 check_clients(void)
981 {
982 	int s;
983 	struct pollfd pfd;
984 	list<client_t>::iterator i;
985 
986 	/*
987 	 * Check all existing clients to see if any of them have disappeared.
988 	 * Normally we reap clients when we get an error trying to send them an
989 	 * event.  This check eliminates the problem of an ever-growing list of
990 	 * zombie clients because we're never writing to them on a system
991 	 * without frequent device-change activity.
992 	 */
993 	pfd.events = 0;
994 	for (i = clients.begin(); i != clients.end(); ) {
995 		pfd.fd = i->fd;
996 		s = poll(&pfd, 1, 0);
997 		if ((s < 0 && s != EINTR ) ||
998 		    (s > 0 && (pfd.revents & POLLHUP))) {
999 			--num_clients;
1000 			close(i->fd);
1001 			i = clients.erase(i);
1002 			devdlog(LOG_NOTICE, "check_clients:  "
1003 			    "dropping disconnected client\n");
1004 		} else
1005 			++i;
1006 	}
1007 }
1008 
1009 static void
1010 new_client(int fd, int socktype)
1011 {
1012 	client_t s;
1013 	int sndbuf_size;
1014 
1015 	/*
1016 	 * First go reap any zombie clients, then accept the connection, and
1017 	 * shut down the read side to stop clients from consuming kernel memory
1018 	 * by sending large buffers full of data we'll never read.
1019 	 */
1020 	check_clients();
1021 	s.socktype = socktype;
1022 	s.fd = accept(fd, NULL, NULL);
1023 	if (s.fd != -1) {
1024 		sndbuf_size = CLIENT_BUFSIZE;
1025 		if (setsockopt(s.fd, SOL_SOCKET, SO_SNDBUF, &sndbuf_size,
1026 		    sizeof(sndbuf_size)))
1027 			err(1, "setsockopt");
1028 		shutdown(s.fd, SHUT_RD);
1029 		clients.push_back(s);
1030 		++num_clients;
1031 	} else
1032 		err(1, "accept");
1033 }
1034 
1035 static void
1036 event_loop(void)
1037 {
1038 	int rv;
1039 	int fd;
1040 	char buffer[DEVCTL_MAXBUF];
1041 	int once = 0;
1042 	int stream_fd, seqpacket_fd, max_fd;
1043 	int accepting;
1044 	timeval tv;
1045 	fd_set fds;
1046 
1047 	fd = open(PATH_DEVCTL, O_RDONLY | O_CLOEXEC);
1048 	if (fd == -1)
1049 		err(1, "Can't open devctl device %s", PATH_DEVCTL);
1050 	stream_fd = create_socket(STREAMPIPE, SOCK_STREAM);
1051 	seqpacket_fd = create_socket(SEQPACKETPIPE, SOCK_SEQPACKET);
1052 	accepting = 1;
1053 	max_fd = max(fd, max(stream_fd, seqpacket_fd)) + 1;
1054 	while (!romeo_must_die) {
1055 		if (!once && !no_daemon && !daemonize_quick) {
1056 			// Check to see if we have any events pending.
1057 			tv.tv_sec = 0;
1058 			tv.tv_usec = 0;
1059 			FD_ZERO(&fds);
1060 			FD_SET(fd, &fds);
1061 			rv = select(fd + 1, &fds, NULL, NULL, &tv);
1062 			// No events -> we've processed all pending events
1063 			if (rv == 0) {
1064 				devdlog(LOG_DEBUG, "Calling daemon\n");
1065 				cfg.remove_pidfile();
1066 				cfg.open_pidfile();
1067 				daemon(0, 0);
1068 				cfg.write_pidfile();
1069 				once++;
1070 			}
1071 		}
1072 		/*
1073 		 * When we've already got the max number of clients, stop
1074 		 * accepting new connections (don't put the listening sockets in
1075 		 * the set), shrink the accept() queue to reject connections
1076 		 * quickly, and poll the existing clients more often, so that we
1077 		 * notice more quickly when any of them disappear to free up
1078 		 * client slots.
1079 		 */
1080 		FD_ZERO(&fds);
1081 		FD_SET(fd, &fds);
1082 		if (num_clients < max_clients) {
1083 			if (!accepting) {
1084 				listen(stream_fd, max_clients);
1085 				listen(seqpacket_fd, max_clients);
1086 				accepting = 1;
1087 			}
1088 			FD_SET(stream_fd, &fds);
1089 			FD_SET(seqpacket_fd, &fds);
1090 			tv.tv_sec = 60;
1091 			tv.tv_usec = 0;
1092 		} else {
1093 			if (accepting) {
1094 				listen(stream_fd, 0);
1095 				listen(seqpacket_fd, 0);
1096 				accepting = 0;
1097 			}
1098 			tv.tv_sec = 2;
1099 			tv.tv_usec = 0;
1100 		}
1101 		rv = select(max_fd, &fds, NULL, NULL, &tv);
1102 		if (got_siginfo) {
1103 			devdlog(LOG_NOTICE, "Events received so far=%u\n",
1104 			    total_events);
1105 			got_siginfo = 0;
1106 		}
1107 		if (rv == -1) {
1108 			if (errno == EINTR)
1109 				continue;
1110 			err(1, "select");
1111 		} else if (rv == 0)
1112 			check_clients();
1113 		if (FD_ISSET(fd, &fds)) {
1114 			rv = read(fd, buffer, sizeof(buffer) - 1);
1115 			if (rv > 0) {
1116 				total_events++;
1117 				if (rv == sizeof(buffer) - 1) {
1118 					devdlog(LOG_WARNING, "Warning: "
1119 					    "available event data exceeded "
1120 					    "buffer space\n");
1121 				}
1122 				notify_clients(buffer, rv);
1123 				buffer[rv] = '\0';
1124 				while (buffer[--rv] == '\n')
1125 					buffer[rv] = '\0';
1126 				try {
1127 					process_event(buffer);
1128 				}
1129 				catch (const std::length_error& e) {
1130 					devdlog(LOG_ERR, "Dropping event %s "
1131 					    "due to low memory", buffer);
1132 				}
1133 			} else if (rv < 0) {
1134 				if (errno != EINTR)
1135 					break;
1136 			} else {
1137 				/* EOF */
1138 				break;
1139 			}
1140 		}
1141 		if (FD_ISSET(stream_fd, &fds))
1142 			new_client(stream_fd, SOCK_STREAM);
1143 		/*
1144 		 * Aside from the socket type, both sockets use the same
1145 		 * protocol, so we can process clients the same way.
1146 		 */
1147 		if (FD_ISSET(seqpacket_fd, &fds))
1148 			new_client(seqpacket_fd, SOCK_SEQPACKET);
1149 	}
1150 	cfg.remove_pidfile();
1151 	close(seqpacket_fd);
1152 	close(stream_fd);
1153 	close(fd);
1154 }
1155 
1156 /*
1157  * functions that the parser uses.
1158  */
1159 void
1160 add_attach(int prio, event_proc *p)
1161 {
1162 	cfg.add_attach(prio, p);
1163 }
1164 
1165 void
1166 add_detach(int prio, event_proc *p)
1167 {
1168 	cfg.add_detach(prio, p);
1169 }
1170 
1171 void
1172 add_directory(const char *dir)
1173 {
1174 	cfg.add_directory(dir);
1175 	free(const_cast<char *>(dir));
1176 }
1177 
1178 void
1179 add_nomatch(int prio, event_proc *p)
1180 {
1181 	cfg.add_nomatch(prio, p);
1182 }
1183 
1184 void
1185 add_notify(int prio, event_proc *p)
1186 {
1187 	cfg.add_notify(prio, p);
1188 }
1189 
1190 event_proc *
1191 add_to_event_proc(event_proc *ep, eps *eps)
1192 {
1193 	if (ep == NULL)
1194 		ep = new event_proc();
1195 	ep->add(eps);
1196 	return (ep);
1197 }
1198 
1199 eps *
1200 new_action(const char *cmd)
1201 {
1202 	eps *e = new action(cmd);
1203 	free(const_cast<char *>(cmd));
1204 	return (e);
1205 }
1206 
1207 eps *
1208 new_match(const char *var, const char *re)
1209 {
1210 	/*
1211 	 * In FreeBSD 14, we changed the system=kern to system=kernel for the
1212 	 * resume message to match all the other 'kernel' messages. Generate a
1213 	 * warning for the life of 14.x that we've 'fixed' the file on the fly,
1214 	 * but make it a fatal error in 15.x and newer.
1215 	 */
1216 	if (strcmp(var, "kern") == 0) {
1217 #if __FreeBSD_version < 1500000
1218 		devdlog(LOG_WARNING,
1219 		    "Changing deprecated system='kern' to new name 'kernel' in %s line %d.",
1220 		    curr_cf, lineno);
1221 		free(const_cast<char *>(var));
1222 		var = strdup("kernel");
1223 #elif  __FreeBSD_version < 1600000
1224 		errx(1, "Encountered deprecated system=\"kern\" rule in %s line %d",
1225 		    curr_cf, lineno);
1226 #else
1227 #error "Remove this gross hack"
1228 #endif
1229 	}
1230 
1231 	eps *e = new match(cfg, var, re);
1232 	free(const_cast<char *>(var));
1233 	free(const_cast<char *>(re));
1234 	return (e);
1235 }
1236 
1237 eps *
1238 new_media(const char *var, const char *re)
1239 {
1240 	eps *e = new media(cfg, var, re);
1241 	free(const_cast<char *>(var));
1242 	free(const_cast<char *>(re));
1243 	return (e);
1244 }
1245 
1246 void
1247 set_pidfile(const char *name)
1248 {
1249 	cfg.set_pidfile(name);
1250 	free(const_cast<char *>(name));
1251 }
1252 
1253 void
1254 set_variable(const char *var, const char *val)
1255 {
1256 	cfg.set_variable(var, val);
1257 	free(const_cast<char *>(var));
1258 	free(const_cast<char *>(val));
1259 }
1260 
1261 
1262 
1263 static void
1264 gensighand(int)
1265 {
1266 	romeo_must_die = 1;
1267 }
1268 
1269 /*
1270  * SIGINFO handler.  Will print useful statistics to the syslog or stderr
1271  * as appropriate
1272  */
1273 static void
1274 siginfohand(int)
1275 {
1276 	got_siginfo = 1;
1277 }
1278 
1279 /*
1280  * Local logging function.  Prints to syslog if we're daemonized; stderr
1281  * otherwise.
1282  */
1283 static void
1284 devdlog(int priority, const char* fmt, ...)
1285 {
1286 	va_list argp;
1287 
1288 	va_start(argp, fmt);
1289 	if (no_daemon)
1290 		vfprintf(stderr, fmt, argp);
1291 	else if (quiet_mode == 0 || priority <= LOG_WARNING)
1292 		vsyslog(priority, fmt, argp);
1293 	va_end(argp);
1294 }
1295 
1296 static void
1297 usage()
1298 {
1299 	fprintf(stderr, "usage: %s [-dnq] [-l connlimit] [-f file]\n",
1300 	    getprogname());
1301 	exit(1);
1302 }
1303 
1304 static void
1305 check_devd_enabled()
1306 {
1307 	int val = 0;
1308 	size_t len;
1309 
1310 	len = sizeof(val);
1311 	if (sysctlbyname(SYSCTL, &val, &len, NULL, 0) != 0)
1312 		errx(1, "devctl sysctl missing from kernel!");
1313 	if (val == 0) {
1314 		warnx("Setting " SYSCTL " to 1000");
1315 		val = 1000;
1316 		if (sysctlbyname(SYSCTL, NULL, NULL, &val, sizeof(val)))
1317 			err(1, "sysctlbyname");
1318 	}
1319 }
1320 
1321 /*
1322  * main
1323  */
1324 int
1325 main(int argc, char **argv)
1326 {
1327 	int ch;
1328 
1329 	check_devd_enabled();
1330 	while ((ch = getopt(argc, argv, "df:l:nq")) != -1) {
1331 		switch (ch) {
1332 		case 'd':
1333 			no_daemon = 1;
1334 			break;
1335 		case 'f':
1336 			configfile = optarg;
1337 			break;
1338 		case 'l':
1339 			max_clients = MAX(1, strtoul(optarg, NULL, 0));
1340 			break;
1341 		case 'n':
1342 			daemonize_quick = 1;
1343 			break;
1344 		case 'q':
1345 			quiet_mode = 1;
1346 			break;
1347 		default:
1348 			usage();
1349 		}
1350 	}
1351 
1352 	cfg.parse();
1353 	if (!no_daemon && daemonize_quick) {
1354 		cfg.open_pidfile();
1355 		daemon(0, 0);
1356 		cfg.write_pidfile();
1357 	}
1358 	signal(SIGPIPE, SIG_IGN);
1359 	signal(SIGHUP, gensighand);
1360 	signal(SIGINT, gensighand);
1361 	signal(SIGTERM, gensighand);
1362 	signal(SIGINFO, siginfohand);
1363 	event_loop();
1364 	return (0);
1365 }
1366