xref: /openbsd-src/usr.sbin/slowcgi/slowcgi.c (revision 24bb5fcea3ed904bc467217bdaadb5dfc618d5bf)
1 /*	$OpenBSD: slowcgi.c,v 1.60 2021/04/20 07:35:42 claudio Exp $ */
2 /*
3  * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
4  * Copyright (c) 2013 Florian Obser <florian@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 #include <sys/queue.h>
22 #include <sys/socket.h>
23 #include <sys/stat.h>
24 #include <sys/time.h>
25 #include <sys/un.h>
26 #include <sys/wait.h>
27 #include <arpa/inet.h>
28 #include <err.h>
29 #include <fcntl.h>
30 #include <errno.h>
31 #include <event.h>
32 #include <limits.h>
33 #include <pwd.h>
34 #include <signal.h>
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <syslog.h>
40 #include <unistd.h>
41 
42 #define TIMEOUT_DEFAULT		 120
43 #define SLOWCGI_USER		 "www"
44 
45 #define FCGI_CONTENT_SIZE	 65535
46 #define FCGI_PADDING_SIZE	 255
47 #define FCGI_RECORD_SIZE	 \
48     (sizeof(struct fcgi_record_header) + FCGI_CONTENT_SIZE + FCGI_PADDING_SIZE)
49 
50 #define FCGI_ALIGNMENT		 8
51 #define FCGI_ALIGN(n)		 \
52     (((n) + (FCGI_ALIGNMENT - 1)) & ~(FCGI_ALIGNMENT - 1))
53 
54 #define STDOUT_DONE		 1
55 #define STDERR_DONE		 2
56 #define SCRIPT_DONE		 4
57 
58 #define FCGI_BEGIN_REQUEST	 1
59 #define FCGI_ABORT_REQUEST	 2
60 #define FCGI_END_REQUEST	 3
61 #define FCGI_PARAMS		 4
62 #define FCGI_STDIN		 5
63 #define FCGI_STDOUT		 6
64 #define FCGI_STDERR		 7
65 #define FCGI_DATA		 8
66 #define FCGI_GET_VALUES		 9
67 #define FCGI_GET_VALUES_RESULT	10
68 #define FCGI_UNKNOWN_TYPE	11
69 #define FCGI_MAXTYPE		(FCGI_UNKNOWN_TYPE)
70 
71 #define FCGI_REQUEST_COMPLETE	0
72 #define FCGI_CANT_MPX_CONN	1
73 #define FCGI_OVERLOADED		2
74 #define FCGI_UNKNOWN_ROLE	3
75 
76 #define FD_RESERVE		5
77 #define FD_NEEDED		6
78 int cgi_inflight = 0;
79 
80 struct listener {
81 	struct event	ev, pause;
82 };
83 
84 struct env_val {
85 	SLIST_ENTRY(env_val)	 entry;
86 	char			*val;
87 };
88 SLIST_HEAD(env_head, env_val);
89 
90 struct fcgi_record_header {
91 	uint8_t		version;
92 	uint8_t		type;
93 	uint16_t	id;
94 	uint16_t	content_len;
95 	uint8_t		padding_len;
96 	uint8_t		reserved;
97 }__packed;
98 
99 struct fcgi_response {
100 	TAILQ_ENTRY(fcgi_response)	entry;
101 	uint8_t				data[FCGI_RECORD_SIZE];
102 	size_t				data_pos;
103 	size_t				data_len;
104 };
105 TAILQ_HEAD(fcgi_response_head, fcgi_response);
106 
107 struct fcgi_stdin {
108 	TAILQ_ENTRY(fcgi_stdin)	entry;
109 	uint8_t			data[FCGI_RECORD_SIZE];
110 	size_t			data_pos;
111 	size_t			data_len;
112 };
113 TAILQ_HEAD(fcgi_stdin_head, fcgi_stdin);
114 
115 struct request {
116 	LIST_ENTRY(request)		entry;
117 	struct event			ev;
118 	struct event			resp_ev;
119 	struct event			tmo;
120 	int				fd;
121 	uint8_t				buf[FCGI_RECORD_SIZE];
122 	size_t				buf_pos;
123 	size_t				buf_len;
124 	struct fcgi_response_head	response_head;
125 	struct fcgi_stdin_head		stdin_head;
126 	uint16_t			id;
127 	char				script_name[PATH_MAX];
128 	struct env_head			env;
129 	int				env_count;
130 	pid_t				script_pid;
131 	int				script_status;
132 	struct event			script_ev;
133 	struct event			script_err_ev;
134 	struct event			script_stdin_ev;
135 	int				stdin_fd_closed;
136 	int				stdout_fd_closed;
137 	int				stderr_fd_closed;
138 	uint8_t				script_flags;
139 	uint8_t				request_started;
140 	int				inflight_fds_accounted;
141 };
142 
143 LIST_HEAD(requests_head, request);
144 
145 struct slowcgi_proc {
146 	struct requests_head	requests;
147 	struct event		ev_sigchld;
148 };
149 
150 struct fcgi_begin_request_body {
151 	uint16_t	role;
152 	uint8_t		flags;
153 	uint8_t		reserved[5];
154 }__packed;
155 
156 struct fcgi_end_request_body {
157 	uint32_t	app_status;
158 	uint8_t		protocol_status;
159 	uint8_t		reserved[3];
160 }__packed;
161 
162 __dead void	usage(void);
163 int		slowcgi_listen(char *, struct passwd *);
164 void		slowcgi_paused(int, short, void *);
165 int		accept_reserve(int, struct sockaddr *, socklen_t *, int, int *);
166 void		slowcgi_accept(int, short, void *);
167 void		slowcgi_request(int, short, void *);
168 void		slowcgi_response(int, short, void *);
169 void		slowcgi_add_response(struct request *, struct fcgi_response *);
170 void		slowcgi_timeout(int, short, void *);
171 void		slowcgi_sig_handler(int, short, void *);
172 size_t		parse_record(uint8_t * , size_t, struct request *);
173 void		parse_begin_request(uint8_t *, uint16_t, struct request *,
174 		    uint16_t);
175 void		parse_params(uint8_t *, uint16_t, struct request *, uint16_t);
176 void		parse_stdin(uint8_t *, uint16_t, struct request *, uint16_t);
177 void		exec_cgi(struct request *);
178 void		script_in(int, struct event *, struct request *, uint8_t);
179 void		script_std_in(int, short, void *);
180 void		script_err_in(int, short, void *);
181 void		script_out(int, short, void *);
182 void		create_end_record(struct request *);
183 void		dump_fcgi_record(const char *,
184 		    struct fcgi_record_header *);
185 void		dump_fcgi_record_header(const char *,
186 		    struct fcgi_record_header *);
187 void		dump_fcgi_begin_request_body(const char *,
188 		    struct fcgi_begin_request_body *);
189 void		dump_fcgi_end_request_body(const char *,
190 		    struct fcgi_end_request_body *);
191 void		cleanup_request(struct request *);
192 
193 struct loggers {
194 	__dead void (*err)(int, const char *, ...)
195 	    __attribute__((__format__ (printf, 2, 3)));
196 	__dead void (*errx)(int, const char *, ...)
197 	    __attribute__((__format__ (printf, 2, 3)));
198 	void (*warn)(const char *, ...)
199 	    __attribute__((__format__ (printf, 1, 2)));
200 	void (*warnx)(const char *, ...)
201 	    __attribute__((__format__ (printf, 1, 2)));
202 	void (*info)(const char *, ...)
203 	    __attribute__((__format__ (printf, 1, 2)));
204 	void (*debug)(const char *, ...)
205 	    __attribute__((__format__ (printf, 1, 2)));
206 };
207 
208 const struct loggers conslogger = {
209 	err,
210 	errx,
211 	warn,
212 	warnx,
213 	warnx, /* info */
214 	warnx /* debug */
215 };
216 
217 __dead void	syslog_err(int, const char *, ...)
218 		    __attribute__((__format__ (printf, 2, 3)));
219 __dead void	syslog_errx(int, const char *, ...)
220 		    __attribute__((__format__ (printf, 2, 3)));
221 void		syslog_warn(const char *, ...)
222 		    __attribute__((__format__ (printf, 1, 2)));
223 void		syslog_warnx(const char *, ...)
224 		    __attribute__((__format__ (printf, 1, 2)));
225 void		syslog_info(const char *, ...)
226 		    __attribute__((__format__ (printf, 1, 2)));
227 void		syslog_debug(const char *, ...)
228 		    __attribute__((__format__ (printf, 1, 2)));
229 void		syslog_vstrerror(int, int, const char *, va_list)
230 		    __attribute__((__format__ (printf, 3, 0)));
231 
232 const struct loggers syslogger = {
233 	syslog_err,
234 	syslog_errx,
235 	syslog_warn,
236 	syslog_warnx,
237 	syslog_info,
238 	syslog_debug
239 };
240 
241 const struct loggers *logger = &conslogger;
242 
243 #define lerr(_e, _f...) logger->err((_e), _f)
244 #define lerrx(_e, _f...) logger->errx((_e), _f)
245 #define lwarn(_f...) logger->warn(_f)
246 #define lwarnx(_f...) logger->warnx(_f)
247 #define linfo(_f...) logger->info(_f)
248 #define ldebug(_f...) logger->debug(_f)
249 
250 __dead void
251 usage(void)
252 {
253 	extern char *__progname;
254 	fprintf(stderr,
255 	    "usage: %s [-d] [-p path] [-s socket] [-U user] [-u user]\n",
256 	    __progname);
257 	exit(1);
258 }
259 
260 struct timeval		timeout = { TIMEOUT_DEFAULT, 0 };
261 struct slowcgi_proc	slowcgi_proc;
262 int			debug = 0;
263 int			on = 1;
264 char			*fcgi_socket = "/var/www/run/slowcgi.sock";
265 
266 int
267 main(int argc, char *argv[])
268 {
269 	extern char *__progname;
270 	struct listener	*l = NULL;
271 	struct passwd	*pw;
272 	struct stat	 sb;
273 	int		 c, fd;
274 	const char	*chrootpath = NULL;
275 	const char	*sock_user = SLOWCGI_USER;
276 	const char	*slowcgi_user = SLOWCGI_USER;
277 
278 	/*
279 	 * Ensure we have fds 0-2 open so that we have no fd overlaps
280 	 * in exec_cgi() later. Just exit on error, we don't have enough
281 	 * fds open to output an error message anywhere.
282 	 */
283 	for (c=0; c < 3; c++) {
284 		if (fstat(c, &sb) == -1) {
285 			if ((fd = open("/dev/null", O_RDWR)) != -1) {
286 				if (dup2(fd, c) == -1)
287 					exit(1);
288 				if (fd > c)
289 					close(fd);
290 			} else
291 				exit(1);
292 		}
293 	}
294 
295 	while ((c = getopt(argc, argv, "dp:s:U:u:")) != -1) {
296 		switch (c) {
297 		case 'd':
298 			debug++;
299 			break;
300 		case 'p':
301 			chrootpath = optarg;
302 			break;
303 		case 's':
304 			fcgi_socket = optarg;
305 			break;
306 		case 'U':
307 			sock_user = optarg;
308 			break;
309 		case 'u':
310 			slowcgi_user = optarg;
311 			break;
312 		default:
313 			usage();
314 			/* NOTREACHED */
315 		}
316 	}
317 
318 	if (geteuid() != 0)
319 		errx(1, "need root privileges");
320 
321 	if (!debug && daemon(0, 0) == -1)
322 		err(1, "daemon");
323 
324 	if (!debug) {
325 		openlog(__progname, LOG_PID|LOG_NDELAY, LOG_DAEMON);
326 		logger = &syslogger;
327 	}
328 
329 	ldebug("sock_user: %s", sock_user);
330 	pw = getpwnam(sock_user);
331 	if (pw == NULL)
332 		lerrx(1, "no %s user", sock_user);
333 
334 	fd = slowcgi_listen(fcgi_socket, pw);
335 
336 	ldebug("slowcgi_user: %s", slowcgi_user);
337 	pw = getpwnam(slowcgi_user);
338 	if (pw == NULL)
339 		lerrx(1, "no %s user", slowcgi_user);
340 
341 	if (chrootpath == NULL)
342 		chrootpath = pw->pw_dir;
343 
344 	if (chroot(chrootpath) == -1)
345 		lerr(1, "chroot(%s)", chrootpath);
346 
347 	ldebug("chroot: %s", chrootpath);
348 
349 	if (chdir("/") == -1)
350 		lerr(1, "chdir(/)");
351 
352 	if (setgroups(1, &pw->pw_gid) ||
353 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
354 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
355 		lerr(1, "unable to revoke privs");
356 
357 	if (pledge("stdio rpath unix proc exec", NULL) == -1)
358 		lerr(1, "pledge");
359 
360 	LIST_INIT(&slowcgi_proc.requests);
361 	event_init();
362 
363 	l = calloc(1, sizeof(*l));
364 	if (l == NULL)
365 		lerr(1, "listener ev alloc");
366 
367 	event_set(&l->ev, fd, EV_READ | EV_PERSIST, slowcgi_accept, l);
368 	event_add(&l->ev, NULL);
369 	evtimer_set(&l->pause, slowcgi_paused, l);
370 
371 	signal_set(&slowcgi_proc.ev_sigchld, SIGCHLD, slowcgi_sig_handler,
372 	    &slowcgi_proc);
373 	signal(SIGPIPE, SIG_IGN);
374 
375 	signal_add(&slowcgi_proc.ev_sigchld, NULL);
376 
377 	event_dispatch();
378 	return (0);
379 }
380 
381 int
382 slowcgi_listen(char *path, struct passwd *pw)
383 {
384 	struct sockaddr_un	 sun;
385 	mode_t			 old_umask;
386 	int			 fd;
387 
388 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
389 	    0)) == -1)
390 		lerr(1, "slowcgi_listen: socket");
391 
392 	bzero(&sun, sizeof(sun));
393 	sun.sun_family = AF_UNIX;
394 	if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
395 	    sizeof(sun.sun_path))
396 		lerrx(1, "socket path too long");
397 
398 	if (unlink(path) == -1)
399 		if (errno != ENOENT)
400 			lerr(1, "slowcgi_listen: unlink %s", path);
401 
402 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
403 
404 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1)
405 		lerr(1,"slowcgi_listen: bind: %s", path);
406 
407 	umask(old_umask);
408 
409 	if (chown(path, pw->pw_uid, pw->pw_gid) == -1)
410 		lerr(1, "slowcgi_listen: chown: %s", path);
411 
412 	if (listen(fd, 5) == -1)
413 		lerr(1, "listen");
414 
415 	ldebug("socket: %s", path);
416 	return fd;
417 }
418 
419 void
420 slowcgi_paused(int fd, short events, void *arg)
421 {
422 	struct listener	*l = arg;
423 	event_add(&l->ev, NULL);
424 }
425 
426 int
427 accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
428     int reserve, int *counter)
429 {
430 	int ret;
431 	if (getdtablecount() + reserve +
432 	    ((*counter + 1) * FD_NEEDED) >= getdtablesize()) {
433 		ldebug("inflight fds exceeded");
434 		errno = EMFILE;
435 		return -1;
436 	}
437 
438 	if ((ret = accept4(sockfd, addr, addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC))
439 	    > -1) {
440 		(*counter)++;
441 		ldebug("inflight incremented, now %d", *counter);
442 	}
443 	return ret;
444 }
445 
446 void
447 slowcgi_accept(int fd, short events, void *arg)
448 {
449 	struct listener		*l;
450 	struct sockaddr_storage	 ss;
451 	struct timeval		 backoff;
452 	struct request		*c;
453 	socklen_t		 len;
454 	int			 s;
455 
456 	l = arg;
457 	backoff.tv_sec = 1;
458 	backoff.tv_usec = 0;
459 	c = NULL;
460 
461 	len = sizeof(ss);
462 	if ((s = accept_reserve(fd, (struct sockaddr *)&ss,
463 	    &len, FD_RESERVE, &cgi_inflight)) == -1) {
464 		switch (errno) {
465 		case EINTR:
466 		case EWOULDBLOCK:
467 		case ECONNABORTED:
468 			return;
469 		case EMFILE:
470 		case ENFILE:
471 			event_del(&l->ev);
472 			evtimer_add(&l->pause, &backoff);
473 			return;
474 		default:
475 			lerr(1, "accept");
476 		}
477 	}
478 
479 	c = calloc(1, sizeof(*c));
480 	if (c == NULL) {
481 		lwarn("cannot calloc request");
482 		close(s);
483 		cgi_inflight--;
484 		return;
485 	}
486 	c->fd = s;
487 	c->buf_pos = 0;
488 	c->buf_len = 0;
489 	c->request_started = 0;
490 	c->stdin_fd_closed = c->stdout_fd_closed = c->stderr_fd_closed = 0;
491 	c->inflight_fds_accounted = 0;
492 	TAILQ_INIT(&c->response_head);
493 	TAILQ_INIT(&c->stdin_head);
494 
495 	event_set(&c->ev, s, EV_READ | EV_PERSIST, slowcgi_request, c);
496 	event_add(&c->ev, NULL);
497 	event_set(&c->resp_ev, s, EV_WRITE | EV_PERSIST, slowcgi_response, c);
498 	evtimer_set(&c->tmo, slowcgi_timeout, c);
499 	evtimer_add(&c->tmo, &timeout);
500 	LIST_INSERT_HEAD(&slowcgi_proc.requests, c, entry);
501 }
502 
503 void
504 slowcgi_timeout(int fd, short events, void *arg)
505 {
506 	cleanup_request((struct request*) arg);
507 }
508 
509 void
510 slowcgi_sig_handler(int sig, short event, void *arg)
511 {
512 	struct request		*c;
513 	struct slowcgi_proc	*p;
514 	pid_t			 pid;
515 	int			 status;
516 
517 	p = arg;
518 
519 	switch (sig) {
520 	case SIGCHLD:
521 		while ((pid = waitpid(WAIT_ANY, &status, WNOHANG)) > 0) {
522 			LIST_FOREACH(c, &p->requests, entry)
523 				if (c->script_pid == pid)
524 					break;
525 			if (c == NULL) {
526 				lwarnx("caught exit of unknown child %i", pid);
527 				continue;
528 			}
529 
530 			if (WIFSIGNALED(status))
531 				c->script_status = WTERMSIG(status);
532 			else
533 				c->script_status = WEXITSTATUS(status);
534 
535 			if (c->script_flags == (STDOUT_DONE | STDERR_DONE))
536 				create_end_record(c);
537 			c->script_flags |= SCRIPT_DONE;
538 
539 			ldebug("wait: %s", c->script_name);
540 		}
541 		if (pid == -1 && errno != ECHILD)
542 			lwarn("waitpid");
543 		break;
544 	default:
545 		lerr(1, "unexpected signal: %d", sig);
546 		break;
547 	}
548 }
549 
550 void
551 slowcgi_add_response(struct request *c, struct fcgi_response *resp)
552 {
553 	struct fcgi_record_header	*header;
554 	size_t				 padded_len;
555 
556 	header = (struct fcgi_record_header*)resp->data;
557 
558 	/* The FastCGI spec suggests to align the output buffer */
559 	padded_len = FCGI_ALIGN(resp->data_len);
560 	if (padded_len > resp->data_len) {
561 		/* There should always be FCGI_PADDING_SIZE bytes left */
562 		if (padded_len > FCGI_RECORD_SIZE)
563 			lerr(1, "response too long");
564 		header->padding_len = padded_len - resp->data_len;
565 		resp->data_len = padded_len;
566 	}
567 
568 	TAILQ_INSERT_TAIL(&c->response_head, resp, entry);
569 	event_add(&c->resp_ev, NULL);
570 }
571 
572 void
573 slowcgi_response(int fd, short events, void *arg)
574 {
575 	struct request			*c;
576 	struct fcgi_record_header	*header;
577 	struct fcgi_response		*resp;
578 	ssize_t				 n;
579 
580 	c = arg;
581 
582 	while ((resp = TAILQ_FIRST(&c->response_head))) {
583 		header = (struct fcgi_record_header*) resp->data;
584 		if (debug > 1)
585 			dump_fcgi_record("resp ", header);
586 
587 		n = write(fd, resp->data + resp->data_pos, resp->data_len);
588 		if (n == -1) {
589 			if (errno == EAGAIN || errno == EINTR)
590 				return;
591 			cleanup_request(c);
592 			return;
593 		}
594 		resp->data_pos += n;
595 		resp->data_len -= n;
596 		if (resp->data_len == 0) {
597 			TAILQ_REMOVE(&c->response_head, resp, entry);
598 			free(resp);
599 		}
600 	}
601 
602 	if (TAILQ_EMPTY(&c->response_head)) {
603 		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
604 		    SCRIPT_DONE))
605 			cleanup_request(c);
606 		else
607 			event_del(&c->resp_ev);
608 	}
609 }
610 
611 void
612 slowcgi_request(int fd, short events, void *arg)
613 {
614 	struct request	*c;
615 	ssize_t		 n;
616 	size_t		 parsed;
617 
618 	c = arg;
619 
620 	n = read(fd, c->buf + c->buf_pos + c->buf_len,
621 	    FCGI_RECORD_SIZE - c->buf_pos-c->buf_len);
622 
623 	switch (n) {
624 	case -1:
625 		switch (errno) {
626 		case EINTR:
627 		case EAGAIN:
628 			return;
629 		default:
630 			goto fail;
631 		}
632 		break;
633 
634 	case 0:
635 		ldebug("closed connection");
636 		goto fail;
637 	default:
638 		break;
639 	}
640 
641 	c->buf_len += n;
642 
643 	/*
644 	 * Parse the records as they are received. Per the FastCGI
645 	 * specification, the server need only receive the FastCGI
646 	 * parameter records in full; it is free to begin execution
647 	 * at that point, which is what happens here.
648 	 */
649 	do {
650 		parsed = parse_record(c->buf + c->buf_pos, c->buf_len, c);
651 		c->buf_pos += parsed;
652 		c->buf_len -= parsed;
653 	} while (parsed > 0 && c->buf_len > 0);
654 
655 	/* Make space for further reads */
656 	if (c->buf_len > 0) {
657 		bcopy(c->buf + c->buf_pos, c->buf, c->buf_len);
658 		c->buf_pos = 0;
659 	}
660 	return;
661 fail:
662 	cleanup_request(c);
663 }
664 
665 void
666 parse_begin_request(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
667 {
668 	/* XXX -- FCGI_CANT_MPX_CONN */
669 	if (c->request_started) {
670 		lwarnx("unexpected FCGI_BEGIN_REQUEST, ignoring");
671 		return;
672 	}
673 
674 	if (n != sizeof(struct fcgi_begin_request_body)) {
675 		lwarnx("wrong size %d != %lu", n,
676 		    sizeof(struct fcgi_begin_request_body));
677 		return;
678 	}
679 
680 	c->request_started = 1;
681 
682 	c->id = id;
683 	SLIST_INIT(&c->env);
684 	c->env_count = 0;
685 }
686 
687 void
688 parse_params(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
689 {
690 	struct env_val			*env_entry;
691 	uint32_t			 name_len, val_len;
692 
693 	if (!c->request_started) {
694 		lwarnx("FCGI_PARAMS without FCGI_BEGIN_REQUEST, ignoring");
695 		return;
696 	}
697 
698 	if (c->id != id) {
699 		lwarnx("unexpected id, ignoring");
700 		return;
701 	}
702 
703 	/*
704 	 * If this is the last FastCGI parameter record,
705 	 * begin execution of the CGI script.
706 	 */
707 	if (n == 0) {
708 		exec_cgi(c);
709 		return;
710 	}
711 
712 	while (n > 0) {
713 		if (buf[0] >> 7 == 0) {
714 			name_len = buf[0];
715 			n--;
716 			buf++;
717 		} else {
718 			if (n > 3) {
719 				name_len = ((buf[0] & 0x7f) << 24) +
720 				    (buf[1] << 16) + (buf[2] << 8) + buf[3];
721 				n -= 4;
722 				buf += 4;
723 			} else
724 				return;
725 		}
726 
727 		if (n > 0) {
728 			if (buf[0] >> 7 == 0) {
729 				val_len = buf[0];
730 				n--;
731 				buf++;
732 			} else {
733 				if (n > 3) {
734 					val_len = ((buf[0] & 0x7f) << 24) +
735 					    (buf[1] << 16) + (buf[2] << 8) +
736 					     buf[3];
737 					n -= 4;
738 					buf += 4;
739 				} else
740 					return;
741 			}
742 		} else
743 			return;
744 
745 		if (n < name_len + val_len)
746 			return;
747 
748 		if ((env_entry = malloc(sizeof(struct env_val))) == NULL) {
749 			lwarnx("cannot allocate env_entry");
750 			return;
751 		}
752 
753 		if ((env_entry->val = calloc(sizeof(char), name_len + val_len +
754 		    2)) == NULL) {
755 			lwarnx("cannot allocate env_entry->val");
756 			free(env_entry);
757 			return;
758 		}
759 
760 		bcopy(buf, env_entry->val, name_len);
761 		buf += name_len;
762 		n -= name_len;
763 
764 		env_entry->val[name_len] = '\0';
765 		if (val_len < PATH_MAX && strcmp(env_entry->val,
766 		    "SCRIPT_NAME") == 0 && c->script_name[0] == '\0') {
767 			bcopy(buf, c->script_name, val_len);
768 			c->script_name[val_len] = '\0';
769 		} else if (val_len < PATH_MAX && strcmp(env_entry->val,
770 		    "SCRIPT_FILENAME") == 0) {
771 			bcopy(buf, c->script_name, val_len);
772 			c->script_name[val_len] = '\0';
773 		}
774 		env_entry->val[name_len] = '=';
775 
776 		bcopy(buf, (env_entry->val) + name_len + 1, val_len);
777 		buf += val_len;
778 		n -= val_len;
779 
780 		SLIST_INSERT_HEAD(&c->env, env_entry, entry);
781 		ldebug("env[%d], %s", c->env_count, env_entry->val);
782 		c->env_count++;
783 	}
784 }
785 
786 void
787 parse_stdin(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
788 {
789 	struct fcgi_stdin	*node;
790 
791 	if (c->id != id) {
792 		lwarnx("unexpected id, ignoring");
793 		return;
794 	}
795 
796 	if ((node = calloc(1, sizeof(struct fcgi_stdin))) == NULL) {
797 		lwarnx("cannot calloc stdin node");
798 		return;
799 	}
800 
801 	bcopy(buf, node->data, n);
802 	node->data_pos = 0;
803 	node->data_len = n;
804 
805 	TAILQ_INSERT_TAIL(&c->stdin_head, node, entry);
806 
807 	if (event_initialized(&c->script_stdin_ev))
808 		event_add(&c->script_stdin_ev, NULL);
809 }
810 
811 size_t
812 parse_record(uint8_t *buf, size_t n, struct request *c)
813 {
814 	struct fcgi_record_header	*h;
815 
816 	if (n < sizeof(struct fcgi_record_header))
817 		return (0);
818 
819 	h = (struct fcgi_record_header*) buf;
820 
821 	if (debug > 1)
822 		dump_fcgi_record("", h);
823 
824 	if (n < sizeof(struct fcgi_record_header) + ntohs(h->content_len)
825 	    + h->padding_len)
826 		return (0);
827 
828 	if (h->version != 1)
829 		lerrx(1, "wrong version");
830 
831 	switch (h->type) {
832 	case FCGI_BEGIN_REQUEST:
833 		parse_begin_request(buf + sizeof(struct fcgi_record_header),
834 		    ntohs(h->content_len), c, ntohs(h->id));
835 		break;
836 	case FCGI_PARAMS:
837 		parse_params(buf + sizeof(struct fcgi_record_header),
838 		    ntohs(h->content_len), c, ntohs(h->id));
839 		break;
840 	case FCGI_STDIN:
841 		parse_stdin(buf + sizeof(struct fcgi_record_header),
842 		    ntohs(h->content_len), c, ntohs(h->id));
843 		break;
844 	default:
845 		lwarnx("unimplemented type %d", h->type);
846 		break;
847 	}
848 
849 	return (sizeof(struct fcgi_record_header) + ntohs(h->content_len)
850 	    + h->padding_len);
851 }
852 
853 /*
854  * Fork a new CGI process to handle the request, translating
855  * between FastCGI parameter records and CGI's environment variables,
856  * as well as between the CGI process' stdin/stdout and the
857  * corresponding FastCGI records.
858  */
859 void
860 exec_cgi(struct request *c)
861 {
862 	struct env_val	*env_entry;
863 	int		 s_in[2], s_out[2], s_err[2], i;
864 	pid_t		 pid;
865 	char		*argv[2];
866 	char		**env;
867 	char		*path;
868 
869 	i = 0;
870 
871 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_in) == -1)
872 		lerr(1, "socketpair");
873 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_out) == -1)
874 		lerr(1, "socketpair");
875 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_err) == -1)
876 		lerr(1, "socketpair");
877 	cgi_inflight--;
878 	c->inflight_fds_accounted = 1;
879 	ldebug("fork: %s", c->script_name);
880 
881 	switch (pid = fork()) {
882 	case -1:
883 		c->script_status = errno;
884 
885 		lwarn("fork");
886 
887 		close(s_in[0]);
888 		close(s_out[0]);
889 		close(s_err[0]);
890 
891 		close(s_in[1]);
892 		close(s_out[1]);
893 		close(s_err[1]);
894 
895 		c->stdin_fd_closed = c->stdout_fd_closed =
896 		    c->stderr_fd_closed = 1;
897 		c->script_flags = (STDOUT_DONE | STDERR_DONE | SCRIPT_DONE);
898 
899 		create_end_record(c);
900 		return;
901 	case 0:
902 		/* Child process */
903 		if (pledge("stdio rpath exec", NULL) == -1)
904 			lerr(1, "pledge");
905 		close(s_in[0]);
906 		close(s_out[0]);
907 		close(s_err[0]);
908 
909 		if (dup2(s_in[1], STDIN_FILENO) == -1)
910 			_exit(1);
911 		if (dup2(s_out[1], STDOUT_FILENO) == -1)
912 			_exit(1);
913 		if (dup2(s_err[1], STDERR_FILENO) == -1)
914 			_exit(1);
915 
916 		close(s_in[1]);
917 		close(s_out[1]);
918 		close(s_err[1]);
919 
920 		signal(SIGPIPE, SIG_DFL);
921 
922 		path = strrchr(c->script_name, '/');
923 		if (path != NULL) {
924 			if (path != c->script_name) {
925 				*path = '\0';
926 				if (chdir(c->script_name) == -1)
927 					lwarn("cannot chdir to %s",
928 					    c->script_name);
929 				*path = '/';
930 			} else
931 				if (chdir("/") == -1)
932 					lwarn("cannot chdir to /");
933 		}
934 
935 		argv[0] = c->script_name;
936 		argv[1] = NULL;
937 		if ((env = calloc(c->env_count + 1, sizeof(char*))) == NULL)
938 			_exit(1);
939 		SLIST_FOREACH(env_entry, &c->env, entry)
940 			env[i++] = env_entry->val;
941 		env[i++] = NULL;
942 		execve(c->script_name, argv, env);
943 		lwarn("execve %s", c->script_name);
944 		_exit(1);
945 
946 	}
947 
948 	/* Parent process*/
949 	close(s_in[1]);
950 	close(s_out[1]);
951 	close(s_err[1]);
952 
953 	fcntl(s_in[0], F_SETFD, FD_CLOEXEC);
954 	fcntl(s_out[0], F_SETFD, FD_CLOEXEC);
955 	fcntl(s_err[0], F_SETFD, FD_CLOEXEC);
956 
957 	if (ioctl(s_in[0], FIONBIO, &on) == -1)
958 		lerr(1, "script ioctl(FIONBIO)");
959 	if (ioctl(s_out[0], FIONBIO, &on) == -1)
960 		lerr(1, "script ioctl(FIONBIO)");
961 	if (ioctl(s_err[0], FIONBIO, &on) == -1)
962 		lerr(1, "script ioctl(FIONBIO)");
963 
964 	c->script_pid = pid;
965 	event_set(&c->script_stdin_ev, s_in[0], EV_WRITE | EV_PERSIST,
966 	    script_out, c);
967 	event_add(&c->script_stdin_ev, NULL);
968 	event_set(&c->script_ev, s_out[0], EV_READ | EV_PERSIST,
969 	    script_std_in, c);
970 	event_add(&c->script_ev, NULL);
971 	event_set(&c->script_err_ev, s_err[0], EV_READ | EV_PERSIST,
972 	    script_err_in, c);
973 	event_add(&c->script_err_ev, NULL);
974 }
975 
976 void
977 create_end_record(struct request *c)
978 {
979 	struct fcgi_response		*resp;
980 	struct fcgi_record_header	*header;
981 	struct fcgi_end_request_body	*end_request;
982 
983 	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
984 		lwarnx("cannot malloc fcgi_response");
985 		return;
986 	}
987 	header = (struct fcgi_record_header*) resp->data;
988 	header->version = 1;
989 	header->type = FCGI_END_REQUEST;
990 	header->id = htons(c->id);
991 	header->content_len = htons(sizeof(struct
992 	    fcgi_end_request_body));
993 	header->padding_len = 0;
994 	header->reserved = 0;
995 	end_request = (struct fcgi_end_request_body *) (resp->data +
996 	    sizeof(struct fcgi_record_header));
997 	end_request->app_status = htonl(c->script_status);
998 	end_request->protocol_status = FCGI_REQUEST_COMPLETE;
999 	end_request->reserved[0] = 0;
1000 	end_request->reserved[1] = 0;
1001 	end_request->reserved[2] = 0;
1002 	resp->data_pos = 0;
1003 	resp->data_len = sizeof(struct fcgi_end_request_body) +
1004 	    sizeof(struct fcgi_record_header);
1005 	slowcgi_add_response(c, resp);
1006 }
1007 
1008 void
1009 script_in(int fd, struct event *ev, struct request *c, uint8_t type)
1010 {
1011 	struct fcgi_response		*resp;
1012 	struct fcgi_record_header	*header;
1013 	ssize_t				 n;
1014 
1015 	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
1016 		lwarnx("cannot malloc fcgi_response");
1017 		return;
1018 	}
1019 	header = (struct fcgi_record_header*) resp->data;
1020 	header->version = 1;
1021 	header->type = type;
1022 	header->id = htons(c->id);
1023 	header->padding_len = 0;
1024 	header->reserved = 0;
1025 
1026 	n = read(fd, resp->data + sizeof(struct fcgi_record_header),
1027 	    FCGI_CONTENT_SIZE);
1028 
1029 	if (n == -1) {
1030 		switch (errno) {
1031 		case EINTR:
1032 		case EAGAIN:
1033 			free(resp);
1034 			return;
1035 		default:
1036 			n = 0; /* fake empty FCGI_STD{OUT,ERR} response */
1037 		}
1038 	}
1039 	header->content_len = htons(n);
1040 	resp->data_pos = 0;
1041 	resp->data_len = n + sizeof(struct fcgi_record_header);
1042 	slowcgi_add_response(c, resp);
1043 
1044 	if (n == 0) {
1045 		if (type == FCGI_STDOUT)
1046 			c->script_flags |= STDOUT_DONE;
1047 		else
1048 			c->script_flags |= STDERR_DONE;
1049 
1050 		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
1051 		    SCRIPT_DONE)) {
1052 			create_end_record(c);
1053 		}
1054 		event_del(ev);
1055 		close(fd);
1056 		if (type == FCGI_STDOUT)
1057 			c->stdout_fd_closed = 1;
1058 		else
1059 			c->stderr_fd_closed = 1;
1060 	}
1061 }
1062 
1063 void
1064 script_std_in(int fd, short events, void *arg)
1065 {
1066 	struct request *c = arg;
1067 	script_in(fd, &c->script_ev, c, FCGI_STDOUT);
1068 }
1069 
1070 void
1071 script_err_in(int fd, short events, void *arg)
1072 {
1073 	struct request *c = arg;
1074 	script_in(fd, &c->script_err_ev, c, FCGI_STDERR);
1075 }
1076 
1077 void
1078 script_out(int fd, short events, void *arg)
1079 {
1080 	struct request		*c;
1081 	struct fcgi_stdin	*node;
1082 	ssize_t			 n;
1083 
1084 	c = arg;
1085 
1086 	while ((node = TAILQ_FIRST(&c->stdin_head))) {
1087 		if (node->data_len == 0) { /* end of stdin marker */
1088 			close(fd);
1089 			c->stdin_fd_closed = 1;
1090 			break;
1091 		}
1092 		n = write(fd, node->data + node->data_pos, node->data_len);
1093 		if (n == -1) {
1094 			if (errno == EAGAIN || errno == EINTR)
1095 				return;
1096 			event_del(&c->script_stdin_ev);
1097 			return;
1098 		}
1099 		node->data_pos += n;
1100 		node->data_len -= n;
1101 		if (node->data_len == 0) {
1102 			TAILQ_REMOVE(&c->stdin_head, node, entry);
1103 			free(node);
1104 		}
1105 	}
1106 	event_del(&c->script_stdin_ev);
1107 }
1108 
1109 void
1110 cleanup_request(struct request *c)
1111 {
1112 	struct fcgi_response	*resp;
1113 	struct fcgi_stdin	*stdin_node;
1114 	struct env_val		*env_entry;
1115 
1116 	evtimer_del(&c->tmo);
1117 	if (event_initialized(&c->ev))
1118 		event_del(&c->ev);
1119 	if (event_initialized(&c->resp_ev))
1120 		event_del(&c->resp_ev);
1121 	if (event_initialized(&c->script_ev)) {
1122 		if (!c->stdout_fd_closed)
1123 			close(EVENT_FD(&c->script_ev));
1124 		event_del(&c->script_ev);
1125 	}
1126 	if (event_initialized(&c->script_err_ev)) {
1127 		if (!c->stderr_fd_closed)
1128 			close(EVENT_FD(&c->script_err_ev));
1129 		event_del(&c->script_err_ev);
1130 	}
1131 	if (event_initialized(&c->script_stdin_ev)) {
1132 		if (!c->stdin_fd_closed)
1133 			close(EVENT_FD(&c->script_stdin_ev));
1134 		event_del(&c->script_stdin_ev);
1135 	}
1136 	close(c->fd);
1137 	while (!SLIST_EMPTY(&c->env)) {
1138 		env_entry = SLIST_FIRST(&c->env);
1139 		SLIST_REMOVE_HEAD(&c->env, entry);
1140 		free(env_entry->val);
1141 		free(env_entry);
1142 	}
1143 
1144 	while ((resp = TAILQ_FIRST(&c->response_head))) {
1145 		TAILQ_REMOVE(&c->response_head, resp, entry);
1146 		free(resp);
1147 	}
1148 	while ((stdin_node = TAILQ_FIRST(&c->stdin_head))) {
1149 		TAILQ_REMOVE(&c->stdin_head, stdin_node, entry);
1150 		free(stdin_node);
1151 	}
1152 	LIST_REMOVE(c, entry);
1153 	if (! c->inflight_fds_accounted)
1154 		cgi_inflight--;
1155 	free(c);
1156 }
1157 
1158 void
1159 dump_fcgi_record(const char *p, struct fcgi_record_header *h)
1160 {
1161 	dump_fcgi_record_header(p, h);
1162 
1163 	if (h->type == FCGI_BEGIN_REQUEST)
1164 		dump_fcgi_begin_request_body(p,
1165 		    (struct fcgi_begin_request_body *)(h + 1));
1166 	else if (h->type == FCGI_END_REQUEST)
1167 		dump_fcgi_end_request_body(p,
1168 		    (struct fcgi_end_request_body *)(h + 1));
1169 }
1170 
1171 void
1172 dump_fcgi_record_header(const char* p, struct fcgi_record_header *h)
1173 {
1174 	ldebug("%sversion:         %d", p, h->version);
1175 	ldebug("%stype:            %d", p, h->type);
1176 	ldebug("%srequestId:       %d", p, ntohs(h->id));
1177 	ldebug("%scontentLength:   %d", p, ntohs(h->content_len));
1178 	ldebug("%spaddingLength:   %d", p, h->padding_len);
1179 	ldebug("%sreserved:        %d", p, h->reserved);
1180 }
1181 
1182 void
1183 dump_fcgi_begin_request_body(const char *p, struct fcgi_begin_request_body *b)
1184 {
1185 	ldebug("%srole             %d", p, ntohs(b->role));
1186 	ldebug("%sflags            %d", p, b->flags);
1187 }
1188 
1189 void
1190 dump_fcgi_end_request_body(const char *p, struct fcgi_end_request_body *b)
1191 {
1192 	ldebug("%sappStatus:       %d", p, ntohl(b->app_status));
1193 	ldebug("%sprotocolStatus:  %d", p, b->protocol_status);
1194 }
1195 
1196 void
1197 syslog_vstrerror(int e, int priority, const char *fmt, va_list ap)
1198 {
1199 	char *s;
1200 
1201 	if (vasprintf(&s, fmt, ap) == -1) {
1202 		syslog(LOG_EMERG, "unable to alloc in syslog_vstrerror");
1203 		exit(1);
1204 	}
1205 	syslog(priority, "%s: %s", s, strerror(e));
1206 	free(s);
1207 }
1208 
1209 __dead void
1210 syslog_err(int ecode, const char *fmt, ...)
1211 {
1212 	va_list ap;
1213 
1214 	va_start(ap, fmt);
1215 	syslog_vstrerror(errno, LOG_CRIT, fmt, ap);
1216 	va_end(ap);
1217 	exit(ecode);
1218 }
1219 
1220 __dead void
1221 syslog_errx(int ecode, const char *fmt, ...)
1222 {
1223 	va_list ap;
1224 
1225 	va_start(ap, fmt);
1226 	vsyslog(LOG_CRIT, fmt, ap);
1227 	va_end(ap);
1228 	exit(ecode);
1229 }
1230 
1231 void
1232 syslog_warn(const char *fmt, ...)
1233 {
1234 	va_list ap;
1235 
1236 	va_start(ap, fmt);
1237 	syslog_vstrerror(errno, LOG_ERR, fmt, ap);
1238 	va_end(ap);
1239 }
1240 
1241 void
1242 syslog_warnx(const char *fmt, ...)
1243 {
1244 	va_list ap;
1245 
1246 	va_start(ap, fmt);
1247 	vsyslog(LOG_ERR, fmt, ap);
1248 	va_end(ap);
1249 }
1250 
1251 void
1252 syslog_info(const char *fmt, ...)
1253 {
1254 	va_list ap;
1255 
1256 	va_start(ap, fmt);
1257 	vsyslog(LOG_INFO, fmt, ap);
1258 	va_end(ap);
1259 }
1260 
1261 void
1262 syslog_debug(const char *fmt, ...)
1263 {
1264 	va_list ap;
1265 
1266 	va_start(ap, fmt);
1267 	vsyslog(LOG_DEBUG, fmt, ap);
1268 	va_end(ap);
1269 }
1270