xref: /openbsd/usr.sbin/slowcgi/slowcgi.c (revision 6f40fd34)
1 /*	$OpenBSD: slowcgi.c,v 1.52 2017/07/04 12:48:36 florian 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 	struct event			ev;
117 	struct event			resp_ev;
118 	struct event			tmo;
119 	int				fd;
120 	uint8_t				buf[FCGI_RECORD_SIZE];
121 	size_t				buf_pos;
122 	size_t				buf_len;
123 	struct fcgi_response_head	response_head;
124 	struct fcgi_stdin_head		stdin_head;
125 	uint16_t			id;
126 	char				script_name[PATH_MAX];
127 	struct env_head			env;
128 	int				env_count;
129 	pid_t				script_pid;
130 	int				script_status;
131 	struct event			script_ev;
132 	struct event			script_err_ev;
133 	struct event			script_stdin_ev;
134 	int				stdin_fd_closed;
135 	int				stdout_fd_closed;
136 	int				stderr_fd_closed;
137 	uint8_t				script_flags;
138 	uint8_t				request_started;
139 	int				inflight_fds_accounted;
140 };
141 
142 struct requests {
143 	SLIST_ENTRY(requests)	 entry;
144 	struct request		*request;
145 };
146 SLIST_HEAD(requests_head, requests);
147 
148 struct slowcgi_proc {
149 	struct requests_head	requests;
150 	struct event		ev_sigchld;
151 	struct event		ev_sigpipe;
152 };
153 
154 struct fcgi_begin_request_body {
155 	uint16_t	role;
156 	uint8_t		flags;
157 	uint8_t		reserved[5];
158 }__packed;
159 
160 struct fcgi_end_request_body {
161 	uint32_t	app_status;
162 	uint8_t		protocol_status;
163 	uint8_t		reserved[3];
164 }__packed;
165 
166 __dead void	usage(void);
167 int		slowcgi_listen(char *, struct passwd *);
168 void		slowcgi_paused(int, short, void *);
169 int		accept_reserve(int, struct sockaddr *, socklen_t *, int,
170 		    volatile int *);
171 void		slowcgi_accept(int, short, void *);
172 void		slowcgi_request(int, short, void *);
173 void		slowcgi_response(int, short, void *);
174 void		slowcgi_add_response(struct request *, struct fcgi_response *);
175 void		slowcgi_timeout(int, short, void *);
176 void		slowcgi_sig_handler(int, short, void *);
177 size_t		parse_record(uint8_t * , size_t, struct request *);
178 void		parse_begin_request(uint8_t *, uint16_t, struct request *,
179 		    uint16_t);
180 void		parse_params(uint8_t *, uint16_t, struct request *, uint16_t);
181 void		parse_stdin(uint8_t *, uint16_t, struct request *, uint16_t);
182 void		exec_cgi(struct request *);
183 void		script_in(int, struct event *, struct request *, uint8_t);
184 void		script_std_in(int, short, void *);
185 void		script_err_in(int, short, void *);
186 void		script_out(int, short, void *);
187 void		create_end_record(struct request *);
188 void		dump_fcgi_record(const char *,
189 		    struct fcgi_record_header *);
190 void		dump_fcgi_record_header(const char *,
191 		    struct fcgi_record_header *);
192 void		dump_fcgi_begin_request_body(const char *,
193 		    struct fcgi_begin_request_body *);
194 void		dump_fcgi_end_request_body(const char *,
195 		    struct fcgi_end_request_body *);
196 void		cleanup_request(struct request *);
197 
198 struct loggers {
199 	__dead void (*err)(int, const char *, ...)
200 	    __attribute__((__format__ (printf, 2, 3)));
201 	__dead void (*errx)(int, const char *, ...)
202 	    __attribute__((__format__ (printf, 2, 3)));
203 	void (*warn)(const char *, ...)
204 	    __attribute__((__format__ (printf, 1, 2)));
205 	void (*warnx)(const char *, ...)
206 	    __attribute__((__format__ (printf, 1, 2)));
207 	void (*info)(const char *, ...)
208 	    __attribute__((__format__ (printf, 1, 2)));
209 	void (*debug)(const char *, ...)
210 	    __attribute__((__format__ (printf, 1, 2)));
211 };
212 
213 const struct loggers conslogger = {
214 	err,
215 	errx,
216 	warn,
217 	warnx,
218 	warnx, /* info */
219 	warnx /* debug */
220 };
221 
222 __dead void	syslog_err(int, const char *, ...)
223 		    __attribute__((__format__ (printf, 2, 3)));
224 __dead void	syslog_errx(int, const char *, ...)
225 		    __attribute__((__format__ (printf, 2, 3)));
226 void		syslog_warn(const char *, ...)
227 		    __attribute__((__format__ (printf, 1, 2)));
228 void		syslog_warnx(const char *, ...)
229 		    __attribute__((__format__ (printf, 1, 2)));
230 void		syslog_info(const char *, ...)
231 		    __attribute__((__format__ (printf, 1, 2)));
232 void		syslog_debug(const char *, ...)
233 		    __attribute__((__format__ (printf, 1, 2)));
234 void		syslog_vstrerror(int, int, const char *, va_list)
235 		    __attribute__((__format__ (printf, 3, 0)));
236 
237 const struct loggers syslogger = {
238 	syslog_err,
239 	syslog_errx,
240 	syslog_warn,
241 	syslog_warnx,
242 	syslog_info,
243 	syslog_debug
244 };
245 
246 const struct loggers *logger = &conslogger;
247 
248 #define lerr(_e, _f...) logger->err((_e), _f)
249 #define lerrx(_e, _f...) logger->errx((_e), _f)
250 #define lwarn(_f...) logger->warn(_f)
251 #define lwarnx(_f...) logger->warnx(_f)
252 #define linfo(_f...) logger->info(_f)
253 #define ldebug(_f...) logger->debug(_f)
254 
255 __dead void
256 usage(void)
257 {
258 	extern char *__progname;
259 	fprintf(stderr, "usage: %s [-d] [-p path] [-s socket] [-u user]\n",
260 	    __progname);
261 	exit(1);
262 }
263 
264 struct timeval		timeout = { TIMEOUT_DEFAULT, 0 };
265 struct slowcgi_proc	slowcgi_proc;
266 int			debug = 0;
267 int			on = 1;
268 char			*fcgi_socket = "/var/www/run/slowcgi.sock";
269 
270 int
271 main(int argc, char *argv[])
272 {
273 	extern char *__progname;
274 	struct listener	*l = NULL;
275 	struct passwd	*pw;
276 	struct stat	 sb;
277 	int		 c, fd;
278 	const char	*chrootpath = NULL;
279 	const char	*slowcgi_user = SLOWCGI_USER;
280 
281 	/*
282 	 * Ensure we have fds 0-2 open so that we have no fd overlaps
283 	 * in exec_cgi() later. Just exit on error, we don't have enough
284 	 * fds open to output an error message anywhere.
285 	 */
286 	for (c=0; c < 3; c++) {
287 		if (fstat(c, &sb) == -1) {
288 			if ((fd = open("/dev/null", O_RDWR)) != -1) {
289 				if (dup2(fd, c) == -1)
290 					exit(1);
291 				if (fd > c)
292 					close(fd);
293 			} else
294 				exit(1);
295 		}
296 	}
297 
298 	while ((c = getopt(argc, argv, "dp:s:u:")) != -1) {
299 		switch (c) {
300 		case 'd':
301 			debug = 1;
302 			break;
303 		case 'p':
304 			chrootpath = optarg;
305 			break;
306 		case 's':
307 			fcgi_socket = 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(1, 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 	pw = getpwnam(SLOWCGI_USER);
330 	if (pw == NULL)
331 		lerrx(1, "no %s user", SLOWCGI_USER);
332 
333 	fd = slowcgi_listen(fcgi_socket, pw);
334 
335 	lwarnx("slowcgi_user: %s", slowcgi_user);
336 	pw = getpwnam(slowcgi_user);
337 	if (pw == NULL)
338 		lerrx(1, "no %s user", slowcgi_user);
339 
340 	if (chrootpath == NULL)
341 		chrootpath = pw->pw_dir;
342 
343 	if (chroot(chrootpath) == -1)
344 		lerr(1, "chroot(%s)", chrootpath);
345 
346 	ldebug("chroot: %s", chrootpath);
347 
348 	if (chdir("/") == -1)
349 		lerr(1, "chdir(/)");
350 
351 	if (setgroups(1, &pw->pw_gid) ||
352 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
353 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
354 		lerr(1, "unable to revoke privs");
355 
356 	if (pledge("stdio rpath unix proc exec", NULL) == -1)
357 		lerr(1, "pledge");
358 
359 	SLIST_INIT(&slowcgi_proc.requests);
360 	event_init();
361 
362 	l = calloc(1, sizeof(*l));
363 	if (l == NULL)
364 		lerr(1, "listener ev alloc");
365 
366 	event_set(&l->ev, fd, EV_READ | EV_PERSIST, slowcgi_accept, l);
367 	event_add(&l->ev, NULL);
368 	evtimer_set(&l->pause, slowcgi_paused, l);
369 
370 	signal_set(&slowcgi_proc.ev_sigchld, SIGCHLD, slowcgi_sig_handler,
371 	    &slowcgi_proc);
372 	signal_set(&slowcgi_proc.ev_sigpipe, SIGPIPE, slowcgi_sig_handler,
373 	    &slowcgi_proc);
374 
375 	signal_add(&slowcgi_proc.ev_sigchld, NULL);
376 	signal_add(&slowcgi_proc.ev_sigpipe, NULL);
377 
378 	event_dispatch();
379 	return (0);
380 }
381 
382 int
383 slowcgi_listen(char *path, struct passwd *pw)
384 {
385 	struct sockaddr_un	 sun;
386 	mode_t			 old_umask;
387 	int			 fd;
388 
389 	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
390 	    0)) == -1)
391 		lerr(1, "slowcgi_listen: socket");
392 
393 	bzero(&sun, sizeof(sun));
394 	sun.sun_family = AF_UNIX;
395 	if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
396 	    sizeof(sun.sun_path))
397 		lerrx(1, "socket path too long");
398 
399 	if (unlink(path) == -1)
400 		if (errno != ENOENT)
401 			lerr(1, "slowcgi_listen: unlink %s", path);
402 
403 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|
404 	    S_IXOTH);
405 
406 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1)
407 		lerr(1,"slowcgi_listen: bind: %s", path);
408 
409 	umask(old_umask);
410 
411 	if (chown(path, pw->pw_uid, pw->pw_gid) == -1)
412 		lerr(1, "slowcgi_listen: chown: %s", path);
413 
414 	if (listen(fd, 5) == -1)
415 		lerr(1, "listen");
416 
417 	ldebug("socket: %s", path);
418 	return fd;
419 }
420 
421 void
422 slowcgi_paused(int fd, short events, void *arg)
423 {
424 	struct listener	*l = arg;
425 	event_add(&l->ev, NULL);
426 }
427 
428 int
429 accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
430 	int reserve, volatile int *counter)
431 {
432 	int ret;
433 	if (getdtablecount() + reserve +
434 	    (*counter * FD_NEEDED) >= getdtablesize()) {
435 		ldebug("inflight fds exceeded");
436 		errno = EMFILE;
437 		return -1;
438 	}
439 
440 	if ((ret = accept4(sockfd, addr, addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC))
441 	    > -1) {
442 		(*counter)++;
443 		ldebug("inflight incremented, now %d", *counter);
444 	}
445 	return ret;
446 }
447 
448 void
449 slowcgi_accept(int fd, short events, void *arg)
450 {
451 	struct listener		*l;
452 	struct sockaddr_storage	 ss;
453 	struct timeval		 backoff;
454 	struct request		*c;
455 	struct requests		*requests;
456 	socklen_t		 len;
457 	int			 s;
458 
459 	l = arg;
460 	backoff.tv_sec = 1;
461 	backoff.tv_usec = 0;
462 	c = NULL;
463 
464 	len = sizeof(ss);
465 	if ((s = accept_reserve(fd, (struct sockaddr *)&ss,
466 	    &len, FD_RESERVE, &cgi_inflight)) == -1) {
467 		switch (errno) {
468 		case EINTR:
469 		case EWOULDBLOCK:
470 		case ECONNABORTED:
471 			return;
472 		case EMFILE:
473 		case ENFILE:
474 			event_del(&l->ev);
475 			evtimer_add(&l->pause, &backoff);
476 			return;
477 		default:
478 			lerr(1, "accept");
479 		}
480 	}
481 
482 	c = calloc(1, sizeof(*c));
483 	if (c == NULL) {
484 		lwarn("cannot calloc request");
485 		close(s);
486 		cgi_inflight--;
487 		return;
488 	}
489 	requests = calloc(1, sizeof(*requests));
490 	if (requests == NULL) {
491 		lwarn("cannot calloc requests");
492 		close(s);
493 		cgi_inflight--;
494 		free(c);
495 		return;
496 	}
497 	c->fd = s;
498 	c->buf_pos = 0;
499 	c->buf_len = 0;
500 	c->request_started = 0;
501 	c->stdin_fd_closed = c->stdout_fd_closed = c->stderr_fd_closed = 0;
502 	c->inflight_fds_accounted = 0;
503 	TAILQ_INIT(&c->response_head);
504 	TAILQ_INIT(&c->stdin_head);
505 
506 	event_set(&c->ev, s, EV_READ | EV_PERSIST, slowcgi_request, c);
507 	event_add(&c->ev, NULL);
508 	event_set(&c->resp_ev, s, EV_WRITE | EV_PERSIST, slowcgi_response, c);
509 	evtimer_set(&c->tmo, slowcgi_timeout, c);
510 	evtimer_add(&c->tmo, &timeout);
511 	requests->request = c;
512 	SLIST_INSERT_HEAD(&slowcgi_proc.requests, requests, entry);
513 }
514 
515 void
516 slowcgi_timeout(int fd, short events, void *arg)
517 {
518 	cleanup_request((struct request*) arg);
519 }
520 
521 void
522 slowcgi_sig_handler(int sig, short event, void *arg)
523 {
524 	struct request		*c;
525 	struct requests		*ncs;
526 	struct slowcgi_proc	*p;
527 	pid_t			 pid;
528 	int			 status;
529 
530 	p = arg;
531 
532 	switch (sig) {
533 	case SIGCHLD:
534 		while ((pid = waitpid(WAIT_ANY, &status, WNOHANG)) > 0) {
535 			c = NULL;
536 			SLIST_FOREACH(ncs, &p->requests, entry)
537 				if (ncs->request->script_pid == pid) {
538 					c = ncs->request;
539 					break;
540 				}
541 			if (c == NULL) {
542 				lwarnx("caught exit of unknown child %i", pid);
543 				continue;
544 			}
545 
546 			if (WIFSIGNALED(status))
547 				c->script_status = WTERMSIG(status);
548 			else
549 				c->script_status = WEXITSTATUS(status);
550 
551 			if (c->script_flags == (STDOUT_DONE | STDERR_DONE))
552 				create_end_record(c);
553 			c->script_flags |= SCRIPT_DONE;
554 
555 			ldebug("wait: %s", c->script_name);
556 		}
557 		if (pid == -1 && errno != ECHILD)
558 			lwarn("waitpid");
559 		break;
560 	case SIGPIPE:
561 		/* ignore */
562 		break;
563 	default:
564 		lerr(1, "unexpected signal: %d", sig);
565 		break;
566 	}
567 }
568 
569 void
570 slowcgi_add_response(struct request *c, struct fcgi_response *resp)
571 {
572 	struct fcgi_record_header	*header;
573 	size_t				 padded_len;
574 
575 	header = (struct fcgi_record_header*)resp->data;
576 
577 	/* The FastCGI spec suggests to align the output buffer */
578 	padded_len = FCGI_ALIGN(resp->data_len);
579 	if (padded_len > resp->data_len) {
580 		/* There should always be FCGI_PADDING_SIZE bytes left */
581 		if (padded_len > FCGI_RECORD_SIZE)
582 			lerr(1, "response too long");
583 		header->padding_len = padded_len - resp->data_len;
584 		resp->data_len = padded_len;
585 	}
586 
587 	TAILQ_INSERT_TAIL(&c->response_head, resp, entry);
588 	event_add(&c->resp_ev, NULL);
589 }
590 
591 void
592 slowcgi_response(int fd, short events, void *arg)
593 {
594 	struct request			*c;
595 	struct fcgi_record_header	*header;
596 	struct fcgi_response		*resp;
597 	ssize_t				 n;
598 
599 	c = arg;
600 
601 	while ((resp = TAILQ_FIRST(&c->response_head))) {
602 		header = (struct fcgi_record_header*) resp->data;
603 		if (debug)
604 			dump_fcgi_record("resp ", header);
605 
606 		n = write(fd, resp->data + resp->data_pos, resp->data_len);
607 		if (n == -1) {
608 			if (errno == EAGAIN || errno == EINTR)
609 				return;
610 			cleanup_request(c);
611 			return;
612 		}
613 		resp->data_pos += n;
614 		resp->data_len -= n;
615 		if (resp->data_len == 0) {
616 			TAILQ_REMOVE(&c->response_head, resp, entry);
617 			free(resp);
618 		}
619 	}
620 
621 	if (TAILQ_EMPTY(&c->response_head)) {
622 		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
623 		    SCRIPT_DONE))
624 			cleanup_request(c);
625 		else
626 			event_del(&c->resp_ev);
627 	}
628 }
629 
630 void
631 slowcgi_request(int fd, short events, void *arg)
632 {
633 	struct request	*c;
634 	ssize_t		 n;
635 	size_t		 parsed;
636 
637 	c = arg;
638 
639 	n = read(fd, c->buf + c->buf_pos + c->buf_len,
640 	    FCGI_RECORD_SIZE - c->buf_pos-c->buf_len);
641 
642 	switch (n) {
643 	case -1:
644 		switch (errno) {
645 		case EINTR:
646 		case EAGAIN:
647 			return;
648 		default:
649 			goto fail;
650 		}
651 		break;
652 
653 	case 0:
654 		ldebug("closed connection");
655 		goto fail;
656 	default:
657 		break;
658 	}
659 
660 	c->buf_len += n;
661 
662 	/*
663 	 * Parse the records as they are received. Per the FastCGI
664 	 * specification, the server need only receive the FastCGI
665 	 * parameter records in full; it is free to begin execution
666 	 * at that point, which is what happens here.
667 	 */
668 	do {
669 		parsed = parse_record(c->buf + c->buf_pos, c->buf_len, c);
670 		c->buf_pos += parsed;
671 		c->buf_len -= parsed;
672 	} while (parsed > 0 && c->buf_len > 0);
673 
674 	/* Make space for further reads */
675 	if (c->buf_len > 0) {
676 		bcopy(c->buf + c->buf_pos, c->buf, c->buf_len);
677 		c->buf_pos = 0;
678 	}
679 	return;
680 fail:
681 	cleanup_request(c);
682 }
683 
684 void
685 parse_begin_request(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
686 {
687 	/* XXX -- FCGI_CANT_MPX_CONN */
688 	if (c->request_started) {
689 		lwarnx("unexpected FCGI_BEGIN_REQUEST, ignoring");
690 		return;
691 	}
692 
693 	if (n != sizeof(struct fcgi_begin_request_body)) {
694 		lwarnx("wrong size %d != %lu", n,
695 		    sizeof(struct fcgi_begin_request_body));
696 		return;
697 	}
698 
699 	c->request_started = 1;
700 
701 	c->id = id;
702 	SLIST_INIT(&c->env);
703 	c->env_count = 0;
704 }
705 void
706 parse_params(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
707 {
708 	struct env_val			*env_entry;
709 	uint32_t			 name_len, val_len;
710 
711 	if (!c->request_started) {
712 		lwarnx("FCGI_PARAMS without FCGI_BEGIN_REQUEST, ignoring");
713 		return;
714 	}
715 
716 	if (c->id != id) {
717 		lwarnx("unexpected id, ignoring");
718 		return;
719 	}
720 
721 	/*
722 	 * If this is the last FastCGI parameter record,
723 	 * begin execution of the CGI script.
724 	 */
725 	if (n == 0) {
726 		exec_cgi(c);
727 		return;
728 	}
729 
730 	while (n > 0) {
731 		if (buf[0] >> 7 == 0) {
732 			name_len = buf[0];
733 			n--;
734 			buf++;
735 		} else {
736 			if (n > 3) {
737 				name_len = ((buf[0] & 0x7f) << 24) +
738 				    (buf[1] << 16) + (buf[2] << 8) + buf[3];
739 				n -= 4;
740 				buf += 4;
741 			} else
742 				return;
743 		}
744 
745 		if (n > 0) {
746 			if (buf[0] >> 7 == 0) {
747 				val_len = buf[0];
748 				n--;
749 				buf++;
750 			} else {
751 				if (n > 3) {
752 					val_len = ((buf[0] & 0x7f) << 24) +
753 					    (buf[1] << 16) + (buf[2] << 8) +
754 					     buf[3];
755 					n -= 4;
756 					buf += 4;
757 				} else
758 					return;
759 			}
760 		} else
761 			return;
762 
763 		if (n < name_len + val_len)
764 			return;
765 
766 		if ((env_entry = malloc(sizeof(struct env_val))) == NULL) {
767 			lwarnx("cannot allocate env_entry");
768 			return;
769 		}
770 
771 		if ((env_entry->val = calloc(sizeof(char), name_len + val_len +
772 		    2)) == NULL) {
773 			lwarnx("cannot allocate env_entry->val");
774 			free(env_entry);
775 			return;
776 		}
777 
778 		bcopy(buf, env_entry->val, name_len);
779 		buf += name_len;
780 		n -= name_len;
781 
782 		env_entry->val[name_len] = '\0';
783 		if (val_len < PATH_MAX && strcmp(env_entry->val,
784 		    "SCRIPT_NAME") == 0 && c->script_name[0] == '\0') {
785 			bcopy(buf, c->script_name, val_len);
786 			c->script_name[val_len] = '\0';
787 		} else if (val_len < PATH_MAX && strcmp(env_entry->val,
788 		    "SCRIPT_FILENAME") == 0) {
789 			bcopy(buf, c->script_name, val_len);
790 			c->script_name[val_len] = '\0';
791 		}
792 		env_entry->val[name_len] = '=';
793 
794 		bcopy(buf, (env_entry->val) + name_len + 1, val_len);
795 		buf += val_len;
796 		n -= val_len;
797 
798 		SLIST_INSERT_HEAD(&c->env, env_entry, entry);
799 		ldebug("env[%d], %s", c->env_count, env_entry->val);
800 		c->env_count++;
801 	}
802 }
803 
804 void
805 parse_stdin(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
806 {
807 	struct fcgi_stdin	*node;
808 
809 	if (c->id != id) {
810 		lwarnx("unexpected id, ignoring");
811 		return;
812 	}
813 
814 	if ((node = calloc(1, sizeof(struct fcgi_stdin))) == NULL) {
815 		lwarnx("cannot calloc stdin node");
816 		return;
817 	}
818 
819 	bcopy(buf, node->data, n);
820 	node->data_pos = 0;
821 	node->data_len = n;
822 
823 	TAILQ_INSERT_TAIL(&c->stdin_head, node, entry);
824 
825 	if (event_initialized(&c->script_stdin_ev))
826 		event_add(&c->script_stdin_ev, NULL);
827 }
828 
829 size_t
830 parse_record(uint8_t *buf, size_t n, struct request *c)
831 {
832 	struct fcgi_record_header	*h;
833 
834 	if (n < sizeof(struct fcgi_record_header))
835 		return (0);
836 
837 	h = (struct fcgi_record_header*) buf;
838 
839 	if (debug)
840 		dump_fcgi_record("", h);
841 
842 	if (n < sizeof(struct fcgi_record_header) + ntohs(h->content_len)
843 	    + h->padding_len)
844 		return (0);
845 
846 	if (h->version != 1)
847 		lerrx(1, "wrong version");
848 
849 	switch (h->type) {
850 	case FCGI_BEGIN_REQUEST:
851 		parse_begin_request(buf + sizeof(struct fcgi_record_header),
852 		    ntohs(h->content_len), c, ntohs(h->id));
853 		break;
854 	case FCGI_PARAMS:
855 		parse_params(buf + sizeof(struct fcgi_record_header),
856 		    ntohs(h->content_len), c, ntohs(h->id));
857 		break;
858 	case FCGI_STDIN:
859 		parse_stdin(buf + sizeof(struct fcgi_record_header),
860 		    ntohs(h->content_len), c, ntohs(h->id));
861 		break;
862 	default:
863 		lwarnx("unimplemented type %d", h->type);
864 		break;
865 	}
866 
867 	return (sizeof(struct fcgi_record_header) + ntohs(h->content_len)
868 	    + h->padding_len);
869 }
870 
871 /*
872  * Fork a new CGI process to handle the request, translating
873  * between FastCGI parameter records and CGI's environment variables,
874  * as well as between the CGI process' stdin/stdout and the
875  * corresponding FastCGI records.
876  */
877 void
878 exec_cgi(struct request *c)
879 {
880 	struct env_val	*env_entry;
881 	int		 s_in[2], s_out[2], s_err[2], i;
882 	pid_t		 pid;
883 	char		*argv[2];
884 	char		**env;
885 	char		*path;
886 
887 	i = 0;
888 
889 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_in) == -1)
890 		lerr(1, "socketpair");
891 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_out) == -1)
892 		lerr(1, "socketpair");
893 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_err) == -1)
894 		lerr(1, "socketpair");
895 	cgi_inflight--;
896 	c->inflight_fds_accounted = 1;
897 	ldebug("fork: %s", c->script_name);
898 
899 	switch (pid = fork()) {
900 	case -1:
901 		c->script_status = errno;
902 
903 		lwarn("fork");
904 
905 		close(s_in[0]);
906 		close(s_out[0]);
907 		close(s_err[0]);
908 
909 		close(s_in[1]);
910 		close(s_out[1]);
911 		close(s_err[1]);
912 
913 		c->stdin_fd_closed = c->stdout_fd_closed =
914 		    c->stderr_fd_closed = 1;
915 		c->script_flags = (STDOUT_DONE | STDERR_DONE | SCRIPT_DONE);
916 
917 		create_end_record(c);
918 		return;
919 	case 0:
920 		/* Child process */
921 		if (pledge("stdio rpath exec", NULL) == -1)
922 			lerr(1, "pledge");
923 		close(s_in[0]);
924 		close(s_out[0]);
925 		close(s_err[0]);
926 
927 		if (dup2(s_in[1], STDIN_FILENO) == -1)
928 			_exit(1);
929 		if (dup2(s_out[1], STDOUT_FILENO) == -1)
930 			_exit(1);
931 		if (dup2(s_err[1], STDERR_FILENO) == -1)
932 			_exit(1);
933 
934 		close(s_in[1]);
935 		close(s_out[1]);
936 		close(s_err[1]);
937 
938 		path = strrchr(c->script_name, '/');
939 		if (path != NULL) {
940 			if (path != c->script_name) {
941 				*path = '\0';
942 				if (chdir(c->script_name) == -1)
943 					lwarn("cannot chdir to %s",
944 					    c->script_name);
945 				*path = '/';
946 			} else
947 				if (chdir("/") == -1)
948 					lwarn("cannot chdir to /");
949 		}
950 
951 		argv[0] = c->script_name;
952 		argv[1] = NULL;
953 		if ((env = calloc(c->env_count + 1, sizeof(char*))) == NULL)
954 			_exit(1);
955 		SLIST_FOREACH(env_entry, &c->env, entry)
956 			env[i++] = env_entry->val;
957 		env[i++] = NULL;
958 		execve(c->script_name, argv, env);
959 		lwarn("execve %s", c->script_name);
960 		_exit(1);
961 
962 	}
963 
964 	/* Parent process*/
965 	close(s_in[1]);
966 	close(s_out[1]);
967 	close(s_err[1]);
968 
969 	fcntl(s_in[0], F_SETFD, FD_CLOEXEC);
970 	fcntl(s_out[0], F_SETFD, FD_CLOEXEC);
971 	fcntl(s_err[0], F_SETFD, FD_CLOEXEC);
972 
973 	if (ioctl(s_in[0], FIONBIO, &on) == -1)
974 		lerr(1, "script ioctl(FIONBIO)");
975 	if (ioctl(s_out[0], FIONBIO, &on) == -1)
976 		lerr(1, "script ioctl(FIONBIO)");
977 	if (ioctl(s_err[0], FIONBIO, &on) == -1)
978 		lerr(1, "script ioctl(FIONBIO)");
979 
980 	c->script_pid = pid;
981 	event_set(&c->script_stdin_ev, s_in[0], EV_WRITE | EV_PERSIST,
982 	    script_out, c);
983 	event_add(&c->script_stdin_ev, NULL);
984 	event_set(&c->script_ev, s_out[0], EV_READ | EV_PERSIST,
985 	    script_std_in, c);
986 	event_add(&c->script_ev, NULL);
987 	event_set(&c->script_err_ev, s_err[0], EV_READ | EV_PERSIST,
988 	    script_err_in, c);
989 	event_add(&c->script_err_ev, NULL);
990 }
991 
992 void
993 create_end_record(struct request *c)
994 {
995 	struct fcgi_response		*resp;
996 	struct fcgi_record_header	*header;
997 	struct fcgi_end_request_body	*end_request;
998 
999 	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
1000 		lwarnx("cannot malloc fcgi_response");
1001 		return;
1002 	}
1003 	header = (struct fcgi_record_header*) resp->data;
1004 	header->version = 1;
1005 	header->type = FCGI_END_REQUEST;
1006 	header->id = htons(c->id);
1007 	header->content_len = htons(sizeof(struct
1008 	    fcgi_end_request_body));
1009 	header->padding_len = 0;
1010 	header->reserved = 0;
1011 	end_request = (struct fcgi_end_request_body *) (resp->data +
1012 	    sizeof(struct fcgi_record_header));
1013 	end_request->app_status = htonl(c->script_status);
1014 	end_request->protocol_status = FCGI_REQUEST_COMPLETE;
1015 	end_request->reserved[0] = 0;
1016 	end_request->reserved[1] = 0;
1017 	end_request->reserved[2] = 0;
1018 	resp->data_pos = 0;
1019 	resp->data_len = sizeof(struct fcgi_end_request_body) +
1020 	    sizeof(struct fcgi_record_header);
1021 	slowcgi_add_response(c, resp);
1022 }
1023 
1024 void
1025 script_in(int fd, struct event *ev, struct request *c, uint8_t type)
1026 {
1027 	struct fcgi_response		*resp;
1028 	struct fcgi_record_header	*header;
1029 	ssize_t				 n;
1030 
1031 	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
1032 		lwarnx("cannot malloc fcgi_response");
1033 		return;
1034 	}
1035 	header = (struct fcgi_record_header*) resp->data;
1036 	header->version = 1;
1037 	header->type = type;
1038 	header->id = htons(c->id);
1039 	header->padding_len = 0;
1040 	header->reserved = 0;
1041 
1042 	n = read(fd, resp->data + sizeof(struct fcgi_record_header),
1043 	    FCGI_CONTENT_SIZE);
1044 
1045 	if (n == -1) {
1046 		switch (errno) {
1047 		case EINTR:
1048 		case EAGAIN:
1049 			free(resp);
1050 			return;
1051 		default:
1052 			n = 0; /* fake empty FCGI_STD{OUT,ERR} response */
1053 		}
1054 	}
1055 	header->content_len = htons(n);
1056 	resp->data_pos = 0;
1057 	resp->data_len = n + sizeof(struct fcgi_record_header);
1058 	slowcgi_add_response(c, resp);
1059 
1060 	if (n == 0) {
1061 		if (type == FCGI_STDOUT)
1062 			c->script_flags |= STDOUT_DONE;
1063 		else
1064 			c->script_flags |= STDERR_DONE;
1065 
1066 		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
1067 		    SCRIPT_DONE)) {
1068 			create_end_record(c);
1069 		}
1070 		event_del(ev);
1071 		close(fd);
1072 		if (type == FCGI_STDOUT)
1073 			c->stdout_fd_closed = 1;
1074 		else
1075 			c->stderr_fd_closed = 1;
1076 	}
1077 }
1078 
1079 void
1080 script_std_in(int fd, short events, void *arg)
1081 {
1082 	struct request *c = arg;
1083 	script_in(fd, &c->script_ev, c, FCGI_STDOUT);
1084 }
1085 
1086 void
1087 script_err_in(int fd, short events, void *arg)
1088 {
1089 	struct request *c = arg;
1090 	script_in(fd, &c->script_err_ev, c, FCGI_STDERR);
1091 }
1092 
1093 void
1094 script_out(int fd, short events, void *arg)
1095 {
1096 	struct request		*c;
1097 	struct fcgi_stdin	*node;
1098 	ssize_t			 n;
1099 
1100 	c = arg;
1101 
1102 	while ((node = TAILQ_FIRST(&c->stdin_head))) {
1103 		if (node->data_len == 0) { /* end of stdin marker */
1104 			close(fd);
1105 			c->stdin_fd_closed = 1;
1106 			break;
1107 		}
1108 		n = write(fd, node->data + node->data_pos, node->data_len);
1109 		if (n == -1) {
1110 			if (errno == EAGAIN || errno == EINTR)
1111 				return;
1112 			event_del(&c->script_stdin_ev);
1113 			return;
1114 		}
1115 		node->data_pos += n;
1116 		node->data_len -= n;
1117 		if (node->data_len == 0) {
1118 			TAILQ_REMOVE(&c->stdin_head, node, entry);
1119 			free(node);
1120 		}
1121 	}
1122 	event_del(&c->script_stdin_ev);
1123 }
1124 
1125 void
1126 cleanup_request(struct request *c)
1127 {
1128 	struct fcgi_response	*resp;
1129 	struct fcgi_stdin	*stdin_node;
1130 	struct env_val		*env_entry;
1131 	struct requests		*ncs, *tcs;
1132 
1133 	evtimer_del(&c->tmo);
1134 	if (event_initialized(&c->ev))
1135 		event_del(&c->ev);
1136 	if (event_initialized(&c->resp_ev))
1137 		event_del(&c->resp_ev);
1138 	if (event_initialized(&c->script_ev)) {
1139 		if (!c->stdout_fd_closed)
1140 			close(EVENT_FD(&c->script_ev));
1141 		event_del(&c->script_ev);
1142 	}
1143 	if (event_initialized(&c->script_err_ev)) {
1144 		if (!c->stderr_fd_closed)
1145 			close(EVENT_FD(&c->script_err_ev));
1146 		event_del(&c->script_err_ev);
1147 	}
1148 	if (event_initialized(&c->script_stdin_ev)) {
1149 		if (!c->stdin_fd_closed)
1150 			close(EVENT_FD(&c->script_stdin_ev));
1151 		event_del(&c->script_stdin_ev);
1152 	}
1153 	close(c->fd);
1154 	while (!SLIST_EMPTY(&c->env)) {
1155 		env_entry = SLIST_FIRST(&c->env);
1156 		SLIST_REMOVE_HEAD(&c->env, entry);
1157 		free(env_entry->val);
1158 		free(env_entry);
1159 	}
1160 
1161 	while ((resp = TAILQ_FIRST(&c->response_head))) {
1162 		TAILQ_REMOVE(&c->response_head, resp, entry);
1163 		free(resp);
1164 	}
1165 	while ((stdin_node = TAILQ_FIRST(&c->stdin_head))) {
1166 		TAILQ_REMOVE(&c->stdin_head, stdin_node, entry);
1167 		free(stdin_node);
1168 	}
1169 	SLIST_FOREACH_SAFE(ncs, &slowcgi_proc.requests, entry, tcs) {
1170 		if (ncs->request == c) {
1171 			SLIST_REMOVE(&slowcgi_proc.requests, ncs, requests,
1172 			    entry);
1173 			free(ncs);
1174 			break;
1175 		}
1176 	}
1177 	if (! c->inflight_fds_accounted)
1178 		cgi_inflight--;
1179 	free(c);
1180 }
1181 
1182 void
1183 dump_fcgi_record(const char *p, struct fcgi_record_header *h)
1184 {
1185 	dump_fcgi_record_header(p, h);
1186 
1187 	if (h->type == FCGI_BEGIN_REQUEST)
1188 		dump_fcgi_begin_request_body(p,
1189 		    (struct fcgi_begin_request_body *)(h + 1));
1190 	else if (h->type == FCGI_END_REQUEST)
1191 		dump_fcgi_end_request_body(p,
1192 		    (struct fcgi_end_request_body *)(h + 1));
1193 }
1194 
1195 void
1196 dump_fcgi_record_header(const char* p, struct fcgi_record_header *h)
1197 {
1198 	ldebug("%sversion:         %d", p, h->version);
1199 	ldebug("%stype:            %d", p, h->type);
1200 	ldebug("%srequestId:       %d", p, ntohs(h->id));
1201 	ldebug("%scontentLength:   %d", p, ntohs(h->content_len));
1202 	ldebug("%spaddingLength:   %d", p, h->padding_len);
1203 	ldebug("%sreserved:        %d", p, h->reserved);
1204 }
1205 
1206 void
1207 dump_fcgi_begin_request_body(const char *p, struct fcgi_begin_request_body *b)
1208 {
1209 	ldebug("%srole             %d", p, ntohs(b->role));
1210 	ldebug("%sflags            %d", p, b->flags);
1211 }
1212 
1213 void
1214 dump_fcgi_end_request_body(const char *p, struct fcgi_end_request_body *b)
1215 {
1216 	ldebug("%sappStatus:       %d", p, ntohl(b->app_status));
1217 	ldebug("%sprotocolStatus:  %d", p, b->protocol_status);
1218 }
1219 
1220 void
1221 syslog_vstrerror(int e, int priority, const char *fmt, va_list ap)
1222 {
1223 	char *s;
1224 
1225 	if (vasprintf(&s, fmt, ap) == -1) {
1226 		syslog(LOG_EMERG, "unable to alloc in syslog_vstrerror");
1227 		exit(1);
1228 	}
1229 	syslog(priority, "%s: %s", s, strerror(e));
1230 	free(s);
1231 }
1232 
1233 __dead void
1234 syslog_err(int ecode, const char *fmt, ...)
1235 {
1236 	va_list ap;
1237 
1238 	va_start(ap, fmt);
1239 	syslog_vstrerror(errno, LOG_CRIT, fmt, ap);
1240 	va_end(ap);
1241 	exit(ecode);
1242 }
1243 
1244 __dead void
1245 syslog_errx(int ecode, const char *fmt, ...)
1246 {
1247 	va_list ap;
1248 
1249 	va_start(ap, fmt);
1250 	vsyslog(LOG_CRIT, fmt, ap);
1251 	va_end(ap);
1252 	exit(ecode);
1253 }
1254 
1255 void
1256 syslog_warn(const char *fmt, ...)
1257 {
1258 	va_list ap;
1259 
1260 	va_start(ap, fmt);
1261 	syslog_vstrerror(errno, LOG_ERR, fmt, ap);
1262 	va_end(ap);
1263 }
1264 
1265 void
1266 syslog_warnx(const char *fmt, ...)
1267 {
1268 	va_list ap;
1269 
1270 	va_start(ap, fmt);
1271 	vsyslog(LOG_ERR, fmt, ap);
1272 	va_end(ap);
1273 }
1274 
1275 void
1276 syslog_info(const char *fmt, ...)
1277 {
1278 	va_list ap;
1279 
1280 	va_start(ap, fmt);
1281 	vsyslog(LOG_INFO, fmt, ap);
1282 	va_end(ap);
1283 }
1284 
1285 void
1286 syslog_debug(const char *fmt, ...)
1287 {
1288 	va_list ap;
1289 
1290 	if (!debug)
1291 		return;
1292 
1293 	va_start(ap, fmt);
1294 	vsyslog(LOG_DEBUG, fmt, ap);
1295 	va_end(ap);
1296 }
1297