xref: /linux/tools/perf/builtin-daemon.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <internal/lib.h>
3 #include <subcmd/parse-options.h>
4 #include <api/fd/array.h>
5 #include <api/fs/fs.h>
6 #include <linux/zalloc.h>
7 #include <linux/string.h>
8 #include <linux/limits.h>
9 #include <linux/string.h>
10 #include <string.h>
11 #include <sys/file.h>
12 #include <signal.h>
13 #include <stdlib.h>
14 #include <time.h>
15 #include <stdio.h>
16 #include <unistd.h>
17 #include <errno.h>
18 #include <sys/inotify.h>
19 #include <libgen.h>
20 #include <sys/types.h>
21 #include <sys/socket.h>
22 #include <sys/un.h>
23 #include <sys/stat.h>
24 #include <sys/signalfd.h>
25 #include <sys/wait.h>
26 #include <poll.h>
27 #include <sys/stat.h>
28 #include <time.h>
29 #include "builtin.h"
30 #include "perf.h"
31 #include "debug.h"
32 #include "config.h"
33 #include "util.h"
34 
35 #define SESSION_OUTPUT  "output"
36 #define SESSION_CONTROL "control"
37 #define SESSION_ACK     "ack"
38 
39 /*
40  * Session states:
41  *
42  *   OK       - session is up and running
43  *   RECONFIG - session is pending for reconfiguration,
44  *              new values are already loaded in session object
45  *   KILL     - session is pending to be killed
46  *
47  * Session object life and its state is maintained by
48  * following functions:
49  *
50  *  setup_server_config
51  *    - reads config file and setup session objects
52  *      with following states:
53  *
54  *      OK       - no change needed
55  *      RECONFIG - session needs to be changed
56  *                 (run variable changed)
57  *      KILL     - session needs to be killed
58  *                 (session is no longer in config file)
59  *
60  *  daemon__reconfig
61  *    - scans session objects and does following actions
62  *      for states:
63  *
64  *      OK       - skip
65  *      RECONFIG - session is killed and re-run with new config
66  *      KILL     - session is killed
67  *
68  *    - all sessions have OK state on the function exit
69  */
70 enum daemon_session_state {
71 	OK,
72 	RECONFIG,
73 	KILL,
74 };
75 
76 struct daemon_session {
77 	char				*base;
78 	char				*name;
79 	char				*run;
80 	char				*control;
81 	int				 pid;
82 	struct list_head		 list;
83 	enum daemon_session_state	 state;
84 	time_t				 start;
85 };
86 
87 struct daemon {
88 	const char		*config;
89 	char			*config_real;
90 	char			*config_base;
91 	const char		*csv_sep;
92 	const char		*base_user;
93 	char			*base;
94 	struct list_head	 sessions;
95 	FILE			*out;
96 	char			 perf[PATH_MAX];
97 	int			 signal_fd;
98 	time_t			 start;
99 };
100 
101 static struct daemon __daemon = {
102 	.sessions = LIST_HEAD_INIT(__daemon.sessions),
103 };
104 
105 static const char * const daemon_usage[] = {
106 	"perf daemon start [<options>]",
107 	"perf daemon [<options>]",
108 	NULL
109 };
110 
111 static bool done;
112 
113 static void sig_handler(int sig __maybe_unused)
114 {
115 	done = true;
116 }
117 
118 static struct daemon_session *daemon__add_session(struct daemon *config, char *name)
119 {
120 	struct daemon_session *session = zalloc(sizeof(*session));
121 
122 	if (!session)
123 		return NULL;
124 
125 	session->name = strdup(name);
126 	if (!session->name) {
127 		free(session);
128 		return NULL;
129 	}
130 
131 	session->pid = -1;
132 	list_add_tail(&session->list, &config->sessions);
133 	return session;
134 }
135 
136 static struct daemon_session *daemon__find_session(struct daemon *daemon, char *name)
137 {
138 	struct daemon_session *session;
139 
140 	list_for_each_entry(session, &daemon->sessions, list) {
141 		if (!strcmp(session->name, name))
142 			return session;
143 	}
144 
145 	return NULL;
146 }
147 
148 static int get_session_name(const char *var, char *session, int len)
149 {
150 	const char *p = var + sizeof("session-") - 1;
151 
152 	while (*p != '.' && *p != 0x0 && len--)
153 		*session++ = *p++;
154 
155 	*session = 0;
156 	return *p == '.' ? 0 : -EINVAL;
157 }
158 
159 static int session_config(struct daemon *daemon, const char *var, const char *value)
160 {
161 	struct daemon_session *session;
162 	char name[100];
163 
164 	if (get_session_name(var, name, sizeof(name)))
165 		return -EINVAL;
166 
167 	var = strchr(var, '.');
168 	if (!var)
169 		return -EINVAL;
170 
171 	var++;
172 
173 	session = daemon__find_session(daemon, name);
174 
175 	if (!session) {
176 		/* New session is defined. */
177 		session = daemon__add_session(daemon, name);
178 		if (!session)
179 			return -ENOMEM;
180 
181 		pr_debug("reconfig: found new session %s\n", name);
182 
183 		/* Trigger reconfig to start it. */
184 		session->state = RECONFIG;
185 	} else if (session->state == KILL) {
186 		/* Current session is defined, no action needed. */
187 		pr_debug("reconfig: found current session %s\n", name);
188 		session->state = OK;
189 	}
190 
191 	if (!strcmp(var, "run")) {
192 		bool same = false;
193 
194 		if (session->run)
195 			same = !strcmp(session->run, value);
196 
197 		if (!same) {
198 			if (session->run) {
199 				free(session->run);
200 				pr_debug("reconfig: session %s is changed\n", name);
201 			}
202 
203 			session->run = strdup(value);
204 			if (!session->run)
205 				return -ENOMEM;
206 
207 			/*
208 			 * Either new or changed run value is defined,
209 			 * trigger reconfig for the session.
210 			 */
211 			session->state = RECONFIG;
212 		}
213 	}
214 
215 	return 0;
216 }
217 
218 static int server_config(const char *var, const char *value, void *cb)
219 {
220 	struct daemon *daemon = cb;
221 
222 	if (strstarts(var, "session-")) {
223 		return session_config(daemon, var, value);
224 	} else if (!strcmp(var, "daemon.base") && !daemon->base_user) {
225 		if (daemon->base && strcmp(daemon->base, value)) {
226 			pr_err("failed: can't redefine base, bailing out\n");
227 			return -EINVAL;
228 		}
229 		daemon->base = strdup(value);
230 		if (!daemon->base)
231 			return -ENOMEM;
232 	}
233 
234 	return 0;
235 }
236 
237 static int client_config(const char *var, const char *value, void *cb)
238 {
239 	struct daemon *daemon = cb;
240 
241 	if (!strcmp(var, "daemon.base") && !daemon->base_user) {
242 		daemon->base = strdup(value);
243 		if (!daemon->base)
244 			return -ENOMEM;
245 	}
246 
247 	return 0;
248 }
249 
250 static int check_base(struct daemon *daemon)
251 {
252 	struct stat st;
253 
254 	if (!daemon->base) {
255 		pr_err("failed: base not defined\n");
256 		return -EINVAL;
257 	}
258 
259 	if (stat(daemon->base, &st)) {
260 		switch (errno) {
261 		case EACCES:
262 			pr_err("failed: permission denied for '%s' base\n",
263 			       daemon->base);
264 			return -EACCES;
265 		case ENOENT:
266 			pr_err("failed: base '%s' does not exists\n",
267 			       daemon->base);
268 			return -EACCES;
269 		default:
270 			pr_err("failed: can't access base '%s': %s\n",
271 			       daemon->base, strerror(errno));
272 			return -errno;
273 		}
274 	}
275 
276 	if ((st.st_mode & S_IFMT) != S_IFDIR) {
277 		pr_err("failed: base '%s' is not directory\n",
278 		       daemon->base);
279 		return -EINVAL;
280 	}
281 
282 	return 0;
283 }
284 
285 static int setup_client_config(struct daemon *daemon)
286 {
287 	struct perf_config_set *set = perf_config_set__load_file(daemon->config_real);
288 	int err = -ENOMEM;
289 
290 	if (set) {
291 		err = perf_config_set(set, client_config, daemon);
292 		perf_config_set__delete(set);
293 	}
294 
295 	return err ?: check_base(daemon);
296 }
297 
298 static int setup_server_config(struct daemon *daemon)
299 {
300 	struct perf_config_set *set;
301 	struct daemon_session *session;
302 	int err = -ENOMEM;
303 
304 	pr_debug("reconfig: started\n");
305 
306 	/*
307 	 * Mark all sessions for kill, the server config
308 	 * will set following states, see explanation at
309 	 * enum daemon_session_state declaration.
310 	 */
311 	list_for_each_entry(session, &daemon->sessions, list)
312 		session->state = KILL;
313 
314 	set = perf_config_set__load_file(daemon->config_real);
315 	if (set) {
316 		err = perf_config_set(set, server_config, daemon);
317 		perf_config_set__delete(set);
318 	}
319 
320 	return err ?: check_base(daemon);
321 }
322 
323 static int daemon_session__run(struct daemon_session *session,
324 			       struct daemon *daemon)
325 {
326 	char buf[PATH_MAX];
327 	char **argv;
328 	int argc, fd;
329 
330 	if (asprintf(&session->base, "%s/session-%s",
331 		     daemon->base, session->name) < 0) {
332 		perror("failed: asprintf");
333 		return -1;
334 	}
335 
336 	if (mkdir(session->base, 0755) && errno != EEXIST) {
337 		perror("failed: mkdir");
338 		return -1;
339 	}
340 
341 	session->start = time(NULL);
342 
343 	session->pid = fork();
344 	if (session->pid < 0)
345 		return -1;
346 	if (session->pid > 0) {
347 		pr_info("reconfig: ruining session [%s:%d]: %s\n",
348 			session->name, session->pid, session->run);
349 		return 0;
350 	}
351 
352 	if (chdir(session->base)) {
353 		perror("failed: chdir");
354 		return -1;
355 	}
356 
357 	fd = open("/dev/null", O_RDONLY);
358 	if (fd < 0) {
359 		perror("failed: open /dev/null");
360 		return -1;
361 	}
362 
363 	dup2(fd, 0);
364 	close(fd);
365 
366 	fd = open(SESSION_OUTPUT, O_RDWR|O_CREAT|O_TRUNC, 0644);
367 	if (fd < 0) {
368 		perror("failed: open session output");
369 		return -1;
370 	}
371 
372 	dup2(fd, 1);
373 	dup2(fd, 2);
374 	close(fd);
375 
376 	if (mkfifo(SESSION_CONTROL, O_RDWR) && errno != EEXIST) {
377 		perror("failed: create control fifo");
378 		return -1;
379 	}
380 
381 	if (mkfifo(SESSION_ACK, O_RDWR) && errno != EEXIST) {
382 		perror("failed: create ack fifo");
383 		return -1;
384 	}
385 
386 	scnprintf(buf, sizeof(buf), "%s record --control=fifo:%s,%s %s",
387 		  daemon->perf, SESSION_CONTROL, SESSION_ACK, session->run);
388 
389 	argv = argv_split(buf, &argc);
390 	if (!argv)
391 		exit(-1);
392 
393 	exit(execve(daemon->perf, argv, NULL));
394 	return -1;
395 }
396 
397 static pid_t handle_signalfd(struct daemon *daemon)
398 {
399 	struct daemon_session *session;
400 	struct signalfd_siginfo si;
401 	ssize_t err;
402 	int status;
403 	pid_t pid;
404 
405 	err = read(daemon->signal_fd, &si, sizeof(struct signalfd_siginfo));
406 	if (err != sizeof(struct signalfd_siginfo))
407 		return -1;
408 
409 	list_for_each_entry(session, &daemon->sessions, list) {
410 
411 		if (session->pid != (int) si.ssi_pid)
412 			continue;
413 
414 		pid = waitpid(session->pid, &status, 0);
415 		if (pid == session->pid) {
416 			if (WIFEXITED(status)) {
417 				pr_info("session '%s' exited, status=%d\n",
418 					session->name, WEXITSTATUS(status));
419 			} else if (WIFSIGNALED(status)) {
420 				pr_info("session '%s' killed (signal %d)\n",
421 					session->name, WTERMSIG(status));
422 			} else if (WIFSTOPPED(status)) {
423 				pr_info("session '%s' stopped (signal %d)\n",
424 					session->name, WSTOPSIG(status));
425 			} else {
426 				pr_info("session '%s' Unexpected status (0x%x)\n",
427 					session->name, status);
428 			}
429 		}
430 
431 		session->state = KILL;
432 		session->pid = -1;
433 		return pid;
434 	}
435 
436 	return 0;
437 }
438 
439 static int daemon_session__wait(struct daemon_session *session, struct daemon *daemon,
440 				int secs)
441 {
442 	struct pollfd pollfd = {
443 		.fd	= daemon->signal_fd,
444 		.events	= POLLIN,
445 	};
446 	pid_t wpid = 0, pid = session->pid;
447 	time_t start;
448 
449 	start = time(NULL);
450 
451 	do {
452 		int err = poll(&pollfd, 1, 1000);
453 
454 		if (err > 0) {
455 			wpid = handle_signalfd(daemon);
456 		} else if (err < 0) {
457 			perror("failed: poll\n");
458 			return -1;
459 		}
460 
461 		if (start + secs < time(NULL))
462 			return -1;
463 	} while (wpid != pid);
464 
465 	return 0;
466 }
467 
468 static bool daemon__has_alive_session(struct daemon *daemon)
469 {
470 	struct daemon_session *session;
471 
472 	list_for_each_entry(session, &daemon->sessions, list) {
473 		if (session->pid != -1)
474 			return true;
475 	}
476 
477 	return false;
478 }
479 
480 static int daemon__wait(struct daemon *daemon, int secs)
481 {
482 	struct pollfd pollfd = {
483 		.fd	= daemon->signal_fd,
484 		.events	= POLLIN,
485 	};
486 	time_t start;
487 
488 	start = time(NULL);
489 
490 	do {
491 		int err = poll(&pollfd, 1, 1000);
492 
493 		if (err > 0) {
494 			handle_signalfd(daemon);
495 		} else if (err < 0) {
496 			perror("failed: poll\n");
497 			return -1;
498 		}
499 
500 		if (start + secs < time(NULL))
501 			return -1;
502 	} while (daemon__has_alive_session(daemon));
503 
504 	return 0;
505 }
506 
507 static int daemon_session__control(struct daemon_session *session,
508 				   const char *msg, bool do_ack)
509 {
510 	struct pollfd pollfd = { .events = POLLIN, };
511 	char control_path[PATH_MAX];
512 	char ack_path[PATH_MAX];
513 	int control, ack = -1, len;
514 	char buf[20];
515 	int ret = -1;
516 	ssize_t err;
517 
518 	/* open the control file */
519 	scnprintf(control_path, sizeof(control_path), "%s/%s",
520 		  session->base, SESSION_CONTROL);
521 
522 	control = open(control_path, O_WRONLY|O_NONBLOCK);
523 	if (!control)
524 		return -1;
525 
526 	if (do_ack) {
527 		/* open the ack file */
528 		scnprintf(ack_path, sizeof(ack_path), "%s/%s",
529 			  session->base, SESSION_ACK);
530 
531 		ack = open(ack_path, O_RDONLY, O_NONBLOCK);
532 		if (!ack) {
533 			close(control);
534 			return -1;
535 		}
536 	}
537 
538 	/* write the command */
539 	len = strlen(msg);
540 
541 	err = writen(control, msg, len);
542 	if (err != len) {
543 		pr_err("failed: write to control pipe: %d (%s)\n",
544 		       errno, control_path);
545 		goto out;
546 	}
547 
548 	if (!do_ack)
549 		goto out;
550 
551 	/* wait for an ack */
552 	pollfd.fd = ack;
553 
554 	if (!poll(&pollfd, 1, 2000)) {
555 		pr_err("failed: control ack timeout\n");
556 		goto out;
557 	}
558 
559 	if (!(pollfd.revents & POLLIN)) {
560 		pr_err("failed: did not received an ack\n");
561 		goto out;
562 	}
563 
564 	err = read(ack, buf, sizeof(buf));
565 	if (err > 0)
566 		ret = strcmp(buf, "ack\n");
567 	else
568 		perror("failed: read ack %d\n");
569 
570 out:
571 	if (ack != -1)
572 		close(ack);
573 
574 	close(control);
575 	return ret;
576 }
577 
578 static int setup_server_socket(struct daemon *daemon)
579 {
580 	struct sockaddr_un addr;
581 	char path[PATH_MAX];
582 	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
583 
584 	if (fd < 0) {
585 		fprintf(stderr, "socket: %s\n", strerror(errno));
586 		return -1;
587 	}
588 
589 	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
590 		perror("failed: fcntl FD_CLOEXEC");
591 		close(fd);
592 		return -1;
593 	}
594 
595 	scnprintf(path, sizeof(path), "%s/control", daemon->base);
596 
597 	if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
598 		pr_err("failed: control path too long '%s'\n", path);
599 		close(fd);
600 		return -1;
601 	}
602 
603 	memset(&addr, 0, sizeof(addr));
604 	addr.sun_family = AF_UNIX;
605 
606 	strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
607 	unlink(path);
608 
609 	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
610 		perror("failed: bind");
611 		close(fd);
612 		return -1;
613 	}
614 
615 	if (listen(fd, 1) == -1) {
616 		perror("failed: listen");
617 		close(fd);
618 		return -1;
619 	}
620 
621 	return fd;
622 }
623 
624 enum {
625 	CMD_LIST   = 0,
626 	CMD_SIGNAL = 1,
627 	CMD_STOP   = 2,
628 	CMD_PING   = 3,
629 	CMD_MAX,
630 };
631 
632 #define SESSION_MAX 64
633 
634 union cmd {
635 	int cmd;
636 
637 	/* CMD_LIST */
638 	struct {
639 		int	cmd;
640 		int	verbose;
641 		char	csv_sep;
642 	} list;
643 
644 	/* CMD_SIGNAL */
645 	struct {
646 		int	cmd;
647 		int	sig;
648 		char	name[SESSION_MAX];
649 	} signal;
650 
651 	/* CMD_PING */
652 	struct {
653 		int	cmd;
654 		char	name[SESSION_MAX];
655 	} ping;
656 };
657 
658 enum {
659 	PING_OK	  = 0,
660 	PING_FAIL = 1,
661 	PING_MAX,
662 };
663 
664 static int daemon_session__ping(struct daemon_session *session)
665 {
666 	return daemon_session__control(session, "ping", true) ?  PING_FAIL : PING_OK;
667 }
668 
669 static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
670 {
671 	char csv_sep = cmd->list.csv_sep;
672 	struct daemon_session *session;
673 	time_t curr = time(NULL);
674 
675 	if (csv_sep) {
676 		fprintf(out, "%d%c%s%c%s%c%s/%s",
677 			/* pid daemon  */
678 			getpid(), csv_sep, "daemon",
679 			/* base */
680 			csv_sep, daemon->base,
681 			/* output */
682 			csv_sep, daemon->base, SESSION_OUTPUT);
683 
684 		fprintf(out, "%c%s/%s",
685 			/* lock */
686 			csv_sep, daemon->base, "lock");
687 
688 		fprintf(out, "%c%lu",
689 			/* session up time */
690 			csv_sep, (curr - daemon->start) / 60);
691 
692 		fprintf(out, "\n");
693 	} else {
694 		fprintf(out, "[%d:daemon] base: %s\n", getpid(), daemon->base);
695 		if (cmd->list.verbose) {
696 			fprintf(out, "  output:  %s/%s\n",
697 				daemon->base, SESSION_OUTPUT);
698 			fprintf(out, "  lock:    %s/lock\n",
699 				daemon->base);
700 			fprintf(out, "  up:      %lu minutes\n",
701 				(curr - daemon->start) / 60);
702 		}
703 	}
704 
705 	list_for_each_entry(session, &daemon->sessions, list) {
706 		if (csv_sep) {
707 			fprintf(out, "%d%c%s%c%s",
708 				/* pid */
709 				session->pid,
710 				/* name */
711 				csv_sep, session->name,
712 				/* base */
713 				csv_sep, session->run);
714 
715 			fprintf(out, "%c%s%c%s/%s",
716 				/* session dir */
717 				csv_sep, session->base,
718 				/* session output */
719 				csv_sep, session->base, SESSION_OUTPUT);
720 
721 			fprintf(out, "%c%s/%s%c%s/%s",
722 				/* session control */
723 				csv_sep, session->base, SESSION_CONTROL,
724 				/* session ack */
725 				csv_sep, session->base, SESSION_ACK);
726 
727 			fprintf(out, "%c%lu",
728 				/* session up time */
729 				csv_sep, (curr - session->start) / 60);
730 
731 			fprintf(out, "\n");
732 		} else {
733 			fprintf(out, "[%d:%s] perf record %s\n",
734 				session->pid, session->name, session->run);
735 			if (!cmd->list.verbose)
736 				continue;
737 			fprintf(out, "  base:    %s\n",
738 				session->base);
739 			fprintf(out, "  output:  %s/%s\n",
740 				session->base, SESSION_OUTPUT);
741 			fprintf(out, "  control: %s/%s\n",
742 				session->base, SESSION_CONTROL);
743 			fprintf(out, "  ack:     %s/%s\n",
744 				session->base, SESSION_ACK);
745 			fprintf(out, "  up:      %lu minutes\n",
746 				(curr - session->start) / 60);
747 		}
748 	}
749 
750 	return 0;
751 }
752 
753 static int daemon_session__signal(struct daemon_session *session, int sig)
754 {
755 	if (session->pid < 0)
756 		return -1;
757 	return kill(session->pid, sig);
758 }
759 
760 static int cmd_session_kill(struct daemon *daemon, union cmd *cmd, FILE *out)
761 {
762 	struct daemon_session *session;
763 	bool all = false;
764 
765 	all = !strcmp(cmd->signal.name, "all");
766 
767 	list_for_each_entry(session, &daemon->sessions, list) {
768 		if (all || !strcmp(cmd->signal.name, session->name)) {
769 			daemon_session__signal(session, cmd->signal.sig);
770 			fprintf(out, "signal %d sent to session '%s [%d]'\n",
771 				cmd->signal.sig, session->name, session->pid);
772 		}
773 	}
774 
775 	return 0;
776 }
777 
778 static const char *ping_str[PING_MAX] = {
779 	[PING_OK]   = "OK",
780 	[PING_FAIL] = "FAIL",
781 };
782 
783 static int cmd_session_ping(struct daemon *daemon, union cmd *cmd, FILE *out)
784 {
785 	struct daemon_session *session;
786 	bool all = false, found = false;
787 
788 	all = !strcmp(cmd->ping.name, "all");
789 
790 	list_for_each_entry(session, &daemon->sessions, list) {
791 		if (all || !strcmp(cmd->ping.name, session->name)) {
792 			int state = daemon_session__ping(session);
793 
794 			fprintf(out, "%-4s %s\n", ping_str[state], session->name);
795 			found = true;
796 		}
797 	}
798 
799 	if (!found && !all) {
800 		fprintf(out, "%-4s %s (not found)\n",
801 			ping_str[PING_FAIL], cmd->ping.name);
802 	}
803 	return 0;
804 }
805 
806 static int handle_server_socket(struct daemon *daemon, int sock_fd)
807 {
808 	int ret = -1, fd;
809 	FILE *out = NULL;
810 	union cmd cmd;
811 
812 	fd = accept(sock_fd, NULL, NULL);
813 	if (fd < 0) {
814 		perror("failed: accept");
815 		return -1;
816 	}
817 
818 	if (sizeof(cmd) != readn(fd, &cmd, sizeof(cmd))) {
819 		perror("failed: read");
820 		goto out;
821 	}
822 
823 	out = fdopen(fd, "w");
824 	if (!out) {
825 		perror("failed: fdopen");
826 		goto out;
827 	}
828 
829 	switch (cmd.cmd) {
830 	case CMD_LIST:
831 		ret = cmd_session_list(daemon, &cmd, out);
832 		break;
833 	case CMD_SIGNAL:
834 		ret = cmd_session_kill(daemon, &cmd, out);
835 		break;
836 	case CMD_STOP:
837 		done = 1;
838 		ret = 0;
839 		pr_debug("perf daemon is exciting\n");
840 		break;
841 	case CMD_PING:
842 		ret = cmd_session_ping(daemon, &cmd, out);
843 		break;
844 	default:
845 		break;
846 	}
847 
848 	fclose(out);
849 out:
850 	/* If out is defined, then fd is closed via fclose. */
851 	if (!out)
852 		close(fd);
853 	return ret;
854 }
855 
856 static int setup_client_socket(struct daemon *daemon)
857 {
858 	struct sockaddr_un addr;
859 	char path[PATH_MAX];
860 	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
861 
862 	if (fd == -1) {
863 		perror("failed: socket");
864 		return -1;
865 	}
866 
867 	scnprintf(path, sizeof(path), "%s/control", daemon->base);
868 
869 	if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
870 		pr_err("failed: control path too long '%s'\n", path);
871 		close(fd);
872 		return -1;
873 	}
874 
875 	memset(&addr, 0, sizeof(addr));
876 	addr.sun_family = AF_UNIX;
877 	strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
878 
879 	if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
880 		perror("failed: connect");
881 		close(fd);
882 		return -1;
883 	}
884 
885 	return fd;
886 }
887 
888 static void daemon_session__kill(struct daemon_session *session,
889 				 struct daemon *daemon)
890 {
891 	int how = 0;
892 
893 	do {
894 		switch (how) {
895 		case 0:
896 			daemon_session__control(session, "stop", false);
897 			break;
898 		case 1:
899 			daemon_session__signal(session, SIGTERM);
900 			break;
901 		case 2:
902 			daemon_session__signal(session, SIGKILL);
903 			break;
904 		default:
905 			break;
906 		}
907 		how++;
908 
909 	} while (daemon_session__wait(session, daemon, 10));
910 }
911 
912 static void daemon__signal(struct daemon *daemon, int sig)
913 {
914 	struct daemon_session *session;
915 
916 	list_for_each_entry(session, &daemon->sessions, list)
917 		daemon_session__signal(session, sig);
918 }
919 
920 static void daemon_session__delete(struct daemon_session *session)
921 {
922 	free(session->base);
923 	free(session->name);
924 	free(session->run);
925 	free(session);
926 }
927 
928 static void daemon_session__remove(struct daemon_session *session)
929 {
930 	list_del(&session->list);
931 	daemon_session__delete(session);
932 }
933 
934 static void daemon__stop(struct daemon *daemon)
935 {
936 	struct daemon_session *session;
937 
938 	list_for_each_entry(session, &daemon->sessions, list)
939 		daemon_session__control(session, "stop", false);
940 }
941 
942 static void daemon__kill(struct daemon *daemon)
943 {
944 	int how = 0;
945 
946 	do {
947 		switch (how) {
948 		case 0:
949 			daemon__stop(daemon);
950 			break;
951 		case 1:
952 			daemon__signal(daemon, SIGTERM);
953 			break;
954 		case 2:
955 			daemon__signal(daemon, SIGKILL);
956 			break;
957 		default:
958 			break;
959 		}
960 		how++;
961 
962 	} while (daemon__wait(daemon, 10));
963 }
964 
965 static void daemon__exit(struct daemon *daemon)
966 {
967 	struct daemon_session *session, *h;
968 
969 	list_for_each_entry_safe(session, h, &daemon->sessions, list)
970 		daemon_session__remove(session);
971 
972 	free(daemon->config_real);
973 	free(daemon->config_base);
974 	free(daemon->base);
975 }
976 
977 static int daemon__reconfig(struct daemon *daemon)
978 {
979 	struct daemon_session *session, *n;
980 
981 	list_for_each_entry_safe(session, n, &daemon->sessions, list) {
982 		/* No change. */
983 		if (session->state == OK)
984 			continue;
985 
986 		/* Remove session. */
987 		if (session->state == KILL) {
988 			if (session->pid > 0) {
989 				daemon_session__kill(session, daemon);
990 				pr_info("reconfig: session '%s' killed\n", session->name);
991 			}
992 			daemon_session__remove(session);
993 			continue;
994 		}
995 
996 		/* Reconfig session. */
997 		if (session->pid > 0) {
998 			daemon_session__kill(session, daemon);
999 			pr_info("reconfig: session '%s' killed\n", session->name);
1000 		}
1001 		if (daemon_session__run(session, daemon))
1002 			return -1;
1003 
1004 		session->state = OK;
1005 	}
1006 
1007 	return 0;
1008 }
1009 
1010 static int setup_config_changes(struct daemon *daemon)
1011 {
1012 	char *basen = strdup(daemon->config_real);
1013 	char *dirn  = strdup(daemon->config_real);
1014 	char *base, *dir;
1015 	int fd, wd = -1;
1016 
1017 	if (!dirn || !basen)
1018 		goto out;
1019 
1020 	fd = inotify_init1(IN_NONBLOCK|O_CLOEXEC);
1021 	if (fd < 0) {
1022 		perror("failed: inotify_init");
1023 		goto out;
1024 	}
1025 
1026 	dir = dirname(dirn);
1027 	base = basename(basen);
1028 	pr_debug("config file: %s, dir: %s\n", base, dir);
1029 
1030 	wd = inotify_add_watch(fd, dir, IN_CLOSE_WRITE);
1031 	if (wd >= 0) {
1032 		daemon->config_base = strdup(base);
1033 		if (!daemon->config_base) {
1034 			close(fd);
1035 			wd = -1;
1036 		}
1037 	} else {
1038 		perror("failed: inotify_add_watch");
1039 	}
1040 
1041 out:
1042 	free(basen);
1043 	free(dirn);
1044 	return wd < 0 ? -1 : fd;
1045 }
1046 
1047 static bool process_inotify_event(struct daemon *daemon, char *buf, ssize_t len)
1048 {
1049 	char *p = buf;
1050 
1051 	while (p < (buf + len)) {
1052 		struct inotify_event *event = (struct inotify_event *) p;
1053 
1054 		/*
1055 		 * We monitor config directory, check if our
1056 		 * config file was changes.
1057 		 */
1058 		if ((event->mask & IN_CLOSE_WRITE) &&
1059 		    !(event->mask & IN_ISDIR)) {
1060 			if (!strcmp(event->name, daemon->config_base))
1061 				return true;
1062 		}
1063 		p += sizeof(*event) + event->len;
1064 	}
1065 	return false;
1066 }
1067 
1068 static int handle_config_changes(struct daemon *daemon, int conf_fd,
1069 				 bool *config_changed)
1070 {
1071 	char buf[4096];
1072 	ssize_t len;
1073 
1074 	while (!(*config_changed)) {
1075 		len = read(conf_fd, buf, sizeof(buf));
1076 		if (len == -1) {
1077 			if (errno != EAGAIN) {
1078 				perror("failed: read");
1079 				return -1;
1080 			}
1081 			return 0;
1082 		}
1083 		*config_changed = process_inotify_event(daemon, buf, len);
1084 	}
1085 	return 0;
1086 }
1087 
1088 static int setup_config(struct daemon *daemon)
1089 {
1090 	if (daemon->base_user) {
1091 		daemon->base = strdup(daemon->base_user);
1092 		if (!daemon->base)
1093 			return -ENOMEM;
1094 	}
1095 
1096 	if (daemon->config) {
1097 		char *real = realpath(daemon->config, NULL);
1098 
1099 		if (!real) {
1100 			perror("failed: realpath");
1101 			return -1;
1102 		}
1103 		daemon->config_real = real;
1104 		return 0;
1105 	}
1106 
1107 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK))
1108 		daemon->config_real = strdup(perf_etc_perfconfig());
1109 	else if (perf_config_global() && perf_home_perfconfig())
1110 		daemon->config_real = strdup(perf_home_perfconfig());
1111 
1112 	return daemon->config_real ? 0 : -1;
1113 }
1114 
1115 #ifndef F_TLOCK
1116 #define F_TLOCK 2
1117 
1118 #include <sys/file.h>
1119 
1120 static int lockf(int fd, int cmd, off_t len)
1121 {
1122 	if (cmd != F_TLOCK || len != 0)
1123 		return -1;
1124 
1125 	return flock(fd, LOCK_EX | LOCK_NB);
1126 }
1127 #endif // F_TLOCK
1128 
1129 /*
1130  * Each daemon tries to create and lock BASE/lock file,
1131  * if it's successful we are sure we're the only daemon
1132  * running over the BASE.
1133  *
1134  * Once daemon is finished, file descriptor to lock file
1135  * is closed and lock is released.
1136  */
1137 static int check_lock(struct daemon *daemon)
1138 {
1139 	char path[PATH_MAX];
1140 	char buf[20];
1141 	int fd, pid;
1142 	ssize_t len;
1143 
1144 	scnprintf(path, sizeof(path), "%s/lock", daemon->base);
1145 
1146 	fd = open(path, O_RDWR|O_CREAT|O_CLOEXEC, 0640);
1147 	if (fd < 0)
1148 		return -1;
1149 
1150 	if (lockf(fd, F_TLOCK, 0) < 0) {
1151 		filename__read_int(path, &pid);
1152 		fprintf(stderr, "failed: another perf daemon (pid %d) owns %s\n",
1153 			pid, daemon->base);
1154 		close(fd);
1155 		return -1;
1156 	}
1157 
1158 	scnprintf(buf, sizeof(buf), "%d", getpid());
1159 	len = strlen(buf);
1160 
1161 	if (write(fd, buf, len) != len) {
1162 		perror("failed: write");
1163 		close(fd);
1164 		return -1;
1165 	}
1166 
1167 	if (ftruncate(fd, len)) {
1168 		perror("failed: ftruncate");
1169 		close(fd);
1170 		return -1;
1171 	}
1172 
1173 	return 0;
1174 }
1175 
1176 static int go_background(struct daemon *daemon)
1177 {
1178 	int pid, fd;
1179 
1180 	pid = fork();
1181 	if (pid < 0)
1182 		return -1;
1183 
1184 	if (pid > 0)
1185 		return 1;
1186 
1187 	if (setsid() < 0)
1188 		return -1;
1189 
1190 	if (check_lock(daemon))
1191 		return -1;
1192 
1193 	umask(0);
1194 
1195 	if (chdir(daemon->base)) {
1196 		perror("failed: chdir");
1197 		return -1;
1198 	}
1199 
1200 	fd = open("output", O_RDWR|O_CREAT|O_TRUNC, 0644);
1201 	if (fd < 0) {
1202 		perror("failed: open");
1203 		return -1;
1204 	}
1205 
1206 	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
1207 		perror("failed: fcntl FD_CLOEXEC");
1208 		close(fd);
1209 		return -1;
1210 	}
1211 
1212 	close(0);
1213 	dup2(fd, 1);
1214 	dup2(fd, 2);
1215 	close(fd);
1216 
1217 	daemon->out = fdopen(1, "w");
1218 	if (!daemon->out) {
1219 		close(1);
1220 		close(2);
1221 		return -1;
1222 	}
1223 
1224 	setbuf(daemon->out, NULL);
1225 	return 0;
1226 }
1227 
1228 static int setup_signalfd(struct daemon *daemon)
1229 {
1230 	sigset_t mask;
1231 
1232 	sigemptyset(&mask);
1233 	sigaddset(&mask, SIGCHLD);
1234 
1235 	if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
1236 		return -1;
1237 
1238 	daemon->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
1239 	return daemon->signal_fd;
1240 }
1241 
1242 static int __cmd_start(struct daemon *daemon, struct option parent_options[],
1243 		       int argc, const char **argv)
1244 {
1245 	bool foreground = false;
1246 	struct option start_options[] = {
1247 		OPT_BOOLEAN('f', "foreground", &foreground, "stay on console"),
1248 		OPT_PARENT(parent_options),
1249 		OPT_END()
1250 	};
1251 	int sock_fd = -1, conf_fd = -1, signal_fd = -1;
1252 	int sock_pos, file_pos, signal_pos;
1253 	struct fdarray fda;
1254 	int err = 0;
1255 
1256 	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1257 	if (argc)
1258 		usage_with_options(daemon_usage, start_options);
1259 
1260 	daemon->start = time(NULL);
1261 
1262 	if (setup_config(daemon)) {
1263 		pr_err("failed: config not found\n");
1264 		return -1;
1265 	}
1266 
1267 	if (setup_server_config(daemon))
1268 		return -1;
1269 
1270 	if (foreground && check_lock(daemon))
1271 		return -1;
1272 
1273 	if (!foreground) {
1274 		err = go_background(daemon);
1275 		if (err) {
1276 			/* original process, exit normally */
1277 			if (err == 1)
1278 				err = 0;
1279 			daemon__exit(daemon);
1280 			return err;
1281 		}
1282 	}
1283 
1284 	debug_set_file(daemon->out);
1285 	debug_set_display_time(true);
1286 
1287 	pr_info("daemon started (pid %d)\n", getpid());
1288 
1289 	fdarray__init(&fda, 3);
1290 
1291 	sock_fd = setup_server_socket(daemon);
1292 	if (sock_fd < 0)
1293 		goto out;
1294 
1295 	conf_fd = setup_config_changes(daemon);
1296 	if (conf_fd < 0)
1297 		goto out;
1298 
1299 	signal_fd = setup_signalfd(daemon);
1300 	if (signal_fd < 0)
1301 		goto out;
1302 
1303 	sock_pos = fdarray__add(&fda, sock_fd, POLLIN|POLLERR|POLLHUP, 0);
1304 	if (sock_pos < 0)
1305 		goto out;
1306 
1307 	file_pos = fdarray__add(&fda, conf_fd, POLLIN|POLLERR|POLLHUP, 0);
1308 	if (file_pos < 0)
1309 		goto out;
1310 
1311 	signal_pos = fdarray__add(&fda, signal_fd, POLLIN|POLLERR|POLLHUP, 0);
1312 	if (signal_pos < 0)
1313 		goto out;
1314 
1315 	signal(SIGINT, sig_handler);
1316 	signal(SIGTERM, sig_handler);
1317 	signal(SIGPIPE, SIG_IGN);
1318 
1319 	while (!done && !err) {
1320 		err = daemon__reconfig(daemon);
1321 
1322 		if (!err && fdarray__poll(&fda, -1)) {
1323 			bool reconfig = false;
1324 
1325 			if (fda.entries[sock_pos].revents & POLLIN)
1326 				err = handle_server_socket(daemon, sock_fd);
1327 			if (fda.entries[file_pos].revents & POLLIN)
1328 				err = handle_config_changes(daemon, conf_fd, &reconfig);
1329 			if (fda.entries[signal_pos].revents & POLLIN)
1330 				err = handle_signalfd(daemon) < 0;
1331 
1332 			if (reconfig)
1333 				err = setup_server_config(daemon);
1334 		}
1335 	}
1336 
1337 out:
1338 	fdarray__exit(&fda);
1339 
1340 	daemon__kill(daemon);
1341 	daemon__exit(daemon);
1342 
1343 	if (sock_fd != -1)
1344 		close(sock_fd);
1345 	if (conf_fd != -1)
1346 		close(conf_fd);
1347 	if (conf_fd != -1)
1348 		close(signal_fd);
1349 
1350 	pr_info("daemon exited\n");
1351 	fclose(daemon->out);
1352 	return err;
1353 }
1354 
1355 static int send_cmd(struct daemon *daemon, union cmd *cmd)
1356 {
1357 	int ret = -1, fd;
1358 	char *line = NULL;
1359 	size_t len = 0;
1360 	ssize_t nread;
1361 	FILE *in = NULL;
1362 
1363 	if (setup_client_config(daemon))
1364 		return -1;
1365 
1366 	fd = setup_client_socket(daemon);
1367 	if (fd < 0)
1368 		return -1;
1369 
1370 	if (sizeof(*cmd) != writen(fd, cmd, sizeof(*cmd))) {
1371 		perror("failed: write");
1372 		goto out;
1373 	}
1374 
1375 	in = fdopen(fd, "r");
1376 	if (!in) {
1377 		perror("failed: fdopen");
1378 		goto out;
1379 	}
1380 
1381 	while ((nread = getline(&line, &len, in)) != -1) {
1382 		if (fwrite(line, nread, 1, stdout) != 1)
1383 			goto out_fclose;
1384 		fflush(stdout);
1385 	}
1386 
1387 	ret = 0;
1388 out_fclose:
1389 	fclose(in);
1390 	free(line);
1391 out:
1392 	/* If in is defined, then fd is closed via fclose. */
1393 	if (!in)
1394 		close(fd);
1395 	return ret;
1396 }
1397 
1398 static int send_cmd_list(struct daemon *daemon)
1399 {
1400 	union cmd cmd = { .cmd = CMD_LIST, };
1401 
1402 	cmd.list.verbose = verbose;
1403 	cmd.list.csv_sep = daemon->csv_sep ? *daemon->csv_sep : 0;
1404 
1405 	return send_cmd(daemon, &cmd);
1406 }
1407 
1408 static int __cmd_signal(struct daemon *daemon, struct option parent_options[],
1409 			int argc, const char **argv)
1410 {
1411 	const char *name = "all";
1412 	struct option start_options[] = {
1413 		OPT_STRING(0, "session", &name, "session",
1414 			"Sent signal to specific session"),
1415 		OPT_PARENT(parent_options),
1416 		OPT_END()
1417 	};
1418 	union cmd cmd;
1419 
1420 	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1421 	if (argc)
1422 		usage_with_options(daemon_usage, start_options);
1423 
1424 	if (setup_config(daemon)) {
1425 		pr_err("failed: config not found\n");
1426 		return -1;
1427 	}
1428 
1429 	cmd.signal.cmd = CMD_SIGNAL,
1430 	cmd.signal.sig = SIGUSR2;
1431 	strncpy(cmd.signal.name, name, sizeof(cmd.signal.name) - 1);
1432 
1433 	return send_cmd(daemon, &cmd);
1434 }
1435 
1436 static int __cmd_stop(struct daemon *daemon, struct option parent_options[],
1437 			int argc, const char **argv)
1438 {
1439 	struct option start_options[] = {
1440 		OPT_PARENT(parent_options),
1441 		OPT_END()
1442 	};
1443 	union cmd cmd = { .cmd = CMD_STOP, };
1444 
1445 	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
1446 	if (argc)
1447 		usage_with_options(daemon_usage, start_options);
1448 
1449 	if (setup_config(daemon)) {
1450 		pr_err("failed: config not found\n");
1451 		return -1;
1452 	}
1453 
1454 	return send_cmd(daemon, &cmd);
1455 }
1456 
1457 static int __cmd_ping(struct daemon *daemon, struct option parent_options[],
1458 		      int argc, const char **argv)
1459 {
1460 	const char *name = "all";
1461 	struct option ping_options[] = {
1462 		OPT_STRING(0, "session", &name, "session",
1463 			"Ping to specific session"),
1464 		OPT_PARENT(parent_options),
1465 		OPT_END()
1466 	};
1467 	union cmd cmd = { .cmd = CMD_PING, };
1468 
1469 	argc = parse_options(argc, argv, ping_options, daemon_usage, 0);
1470 	if (argc)
1471 		usage_with_options(daemon_usage, ping_options);
1472 
1473 	if (setup_config(daemon)) {
1474 		pr_err("failed: config not found\n");
1475 		return -1;
1476 	}
1477 
1478 	scnprintf(cmd.ping.name, sizeof(cmd.ping.name), "%s", name);
1479 	return send_cmd(daemon, &cmd);
1480 }
1481 
1482 int cmd_daemon(int argc, const char **argv)
1483 {
1484 	struct option daemon_options[] = {
1485 		OPT_INCR('v', "verbose", &verbose, "be more verbose"),
1486 		OPT_STRING(0, "config", &__daemon.config,
1487 			"config file", "config file path"),
1488 		OPT_STRING(0, "base", &__daemon.base_user,
1489 			"directory", "base directory"),
1490 		OPT_STRING_OPTARG('x', "field-separator", &__daemon.csv_sep,
1491 			"field separator", "print counts with custom separator", ","),
1492 		OPT_END()
1493 	};
1494 
1495 	perf_exe(__daemon.perf, sizeof(__daemon.perf));
1496 	__daemon.out = stdout;
1497 
1498 	argc = parse_options(argc, argv, daemon_options, daemon_usage,
1499 			     PARSE_OPT_STOP_AT_NON_OPTION);
1500 
1501 	if (argc) {
1502 		if (!strcmp(argv[0], "start"))
1503 			return __cmd_start(&__daemon, daemon_options, argc, argv);
1504 		if (!strcmp(argv[0], "signal"))
1505 			return __cmd_signal(&__daemon, daemon_options, argc, argv);
1506 		else if (!strcmp(argv[0], "stop"))
1507 			return __cmd_stop(&__daemon, daemon_options, argc, argv);
1508 		else if (!strcmp(argv[0], "ping"))
1509 			return __cmd_ping(&__daemon, daemon_options, argc, argv);
1510 
1511 		pr_err("failed: unknown command '%s'\n", argv[0]);
1512 		return -1;
1513 	}
1514 
1515 	if (setup_config(&__daemon)) {
1516 		pr_err("failed: config not found\n");
1517 		return -1;
1518 	}
1519 
1520 	return send_cmd_list(&__daemon);
1521 }
1522