aboutsummaryrefslogtreecommitdiffstats
path: root/slowcgi.c
blob: 391d882e4433a9a730753c4d6eba7389aca2065f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
/*	$OpenBSD: slowcgi.c,v 1.59 2021/04/20 07:32:19 claudio Exp $ */
/*
 * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
 * Copyright (c) 2013 Florian Obser <florian@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <err.h>
#include <fcntl.h>
#include <errno.h>
#include <event.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <grp.h>

#include "getdtablecount.h"
#include "queue.h"

#ifdef strlcpy
#define HAVE_STRLCPY
#else
size_t strlcpy(char *, const char *, size_t);
#endif

#ifndef __packed
#define __packed __attribute__((packed))
#endif

#ifndef __dead
#define __dead __attribute__((noreturn))
#endif

#define TIMEOUT_DEFAULT		 120
#define SLOWCGI_USER		 "www"

#define FCGI_CONTENT_SIZE	 65535
#define FCGI_PADDING_SIZE	 255
#define FCGI_RECORD_SIZE	 \
    (sizeof(struct fcgi_record_header) + FCGI_CONTENT_SIZE + FCGI_PADDING_SIZE)

#define FCGI_ALIGNMENT		 8
#define FCGI_ALIGN(n)		 \
    (((n) + (FCGI_ALIGNMENT - 1)) & ~(FCGI_ALIGNMENT - 1))

#define STDOUT_DONE		 1
#define STDERR_DONE		 2
#define SCRIPT_DONE		 4

#define FCGI_BEGIN_REQUEST	 1
#define FCGI_ABORT_REQUEST	 2
#define FCGI_END_REQUEST	 3
#define FCGI_PARAMS		 4
#define FCGI_STDIN		 5
#define FCGI_STDOUT		 6
#define FCGI_STDERR		 7
#define FCGI_DATA		 8
#define FCGI_GET_VALUES		 9
#define FCGI_GET_VALUES_RESULT	10
#define FCGI_UNKNOWN_TYPE	11
#define FCGI_MAXTYPE		(FCGI_UNKNOWN_TYPE)

#define FCGI_REQUEST_COMPLETE	0
#define FCGI_CANT_MPX_CONN	1
#define FCGI_OVERLOADED		2
#define FCGI_UNKNOWN_ROLE	3

#define FD_RESERVE		5
#define FD_NEEDED		6
int cgi_inflight = 0;

struct listener {
	struct event	ev, pause;
};

struct env_val {
	SLIST_ENTRY(env_val)	 entry;
	char			*val;
};
SLIST_HEAD(env_head, env_val);

struct fcgi_record_header {
	uint8_t		version;
	uint8_t		type;
	uint16_t	id;
	uint16_t	content_len;
	uint8_t		padding_len;
	uint8_t		reserved;
}__packed;

struct fcgi_response {
	TAILQ_ENTRY(fcgi_response)	entry;
	uint8_t				data[FCGI_RECORD_SIZE];
	size_t				data_pos;
	size_t				data_len;
};
TAILQ_HEAD(fcgi_response_head, fcgi_response);

struct fcgi_stdin {
	TAILQ_ENTRY(fcgi_stdin)	entry;
	uint8_t			data[FCGI_RECORD_SIZE];
	size_t			data_pos;
	size_t			data_len;
};
TAILQ_HEAD(fcgi_stdin_head, fcgi_stdin);

struct request {
	struct event			ev;
	struct event			resp_ev;
	struct event			tmo;
	int				fd;
	uint8_t				buf[FCGI_RECORD_SIZE];
	size_t				buf_pos;
	size_t				buf_len;
	struct fcgi_response_head	response_head;
	struct fcgi_stdin_head		stdin_head;
	uint16_t			id;
	char				script_name[PATH_MAX];
	struct env_head			env;
	int				env_count;
	pid_t				script_pid;
	int				script_status;
	struct event			script_ev;
	struct event			script_err_ev;
	struct event			script_stdin_ev;
	int				stdin_fd_closed;
	int				stdout_fd_closed;
	int				stderr_fd_closed;
	uint8_t				script_flags;
	uint8_t				request_started;
	int				inflight_fds_accounted;
};

struct requests {
	SLIST_ENTRY(requests)	 entry;
	struct request		*request;
};
SLIST_HEAD(requests_head, requests);

struct slowcgi_proc {
	struct requests_head	requests;
	struct event		ev_sigchld;
};

struct fcgi_begin_request_body {
	uint16_t	role;
	uint8_t		flags;
	uint8_t		reserved[5];
}__packed;

struct fcgi_end_request_body {
	uint32_t	app_status;
	uint8_t		protocol_status;
	uint8_t		reserved[3];
}__packed;

__dead void	usage(void);
int		slowcgi_listen(char *, struct passwd *);
void		slowcgi_paused(int, short, void *);
int		accept_reserve(int, struct sockaddr *, socklen_t *, int, int *);
void		slowcgi_accept(int, short, void *);
void		slowcgi_request(int, short, void *);
void		slowcgi_response(int, short, void *);
void		slowcgi_add_response(struct request *, struct fcgi_response *);
void		slowcgi_timeout(int, short, void *);
void		slowcgi_sig_handler(int, short, void *);
size_t		parse_record(uint8_t * , size_t, struct request *);
void		parse_begin_request(uint8_t *, uint16_t, struct request *,
		    uint16_t);
void		parse_params(uint8_t *, uint16_t, struct request *, uint16_t);
void		parse_stdin(uint8_t *, uint16_t, struct request *, uint16_t);
void		exec_cgi(struct request *);
void		script_in(int, struct event *, struct request *, uint8_t);
void		script_std_in(int, short, void *);
void		script_err_in(int, short, void *);
void		script_out(int, short, void *);
void		create_end_record(struct request *);
void		dump_fcgi_record(const char *,
		    struct fcgi_record_header *);
void		dump_fcgi_record_header(const char *,
		    struct fcgi_record_header *);
void		dump_fcgi_begin_request_body(const char *,
		    struct fcgi_begin_request_body *);
void		dump_fcgi_end_request_body(const char *,
		    struct fcgi_end_request_body *);
void		cleanup_request(struct request *);

struct loggers {
	__dead void (*err)(int, const char *, ...)
	    __attribute__((__format__ (printf, 2, 3)));
	__dead void (*errx)(int, const char *, ...)
	    __attribute__((__format__ (printf, 2, 3)));
	void (*warn)(const char *, ...)
	    __attribute__((__format__ (printf, 1, 2)));
	void (*warnx)(const char *, ...)
	    __attribute__((__format__ (printf, 1, 2)));
	void (*info)(const char *, ...)
	    __attribute__((__format__ (printf, 1, 2)));
	void (*debug)(const char *, ...)
	    __attribute__((__format__ (printf, 1, 2)));
};

const struct loggers conslogger = {
	err,
	errx,
	warn,
	warnx,
	warnx, /* info */
	warnx /* debug */
};

__dead void	syslog_err(int, const char *, ...)
		    __attribute__((__format__ (printf, 2, 3)));
__dead void	syslog_errx(int, const char *, ...)
		    __attribute__((__format__ (printf, 2, 3)));
void		syslog_warn(const char *, ...)
		    __attribute__((__format__ (printf, 1, 2)));
void		syslog_warnx(const char *, ...)
		    __attribute__((__format__ (printf, 1, 2)));
void		syslog_info(const char *, ...)
		    __attribute__((__format__ (printf, 1, 2)));
void		syslog_debug(const char *, ...)
		    __attribute__((__format__ (printf, 1, 2)));
void		syslog_vstrerror(int, int, const char *, va_list)
		    __attribute__((__format__ (printf, 3, 0)));

const struct loggers syslogger = {
	syslog_err,
	syslog_errx,
	syslog_warn,
	syslog_warnx,
	syslog_info,
	syslog_debug
};

const struct loggers *logger = &conslogger;

#define lerr(_e, _f...) logger->err((_e), _f)
#define lerrx(_e, _f...) logger->errx((_e), _f)
#define lwarn(_f...) logger->warn(_f)
#define lwarnx(_f...) logger->warnx(_f)
#define linfo(_f...) logger->info(_f)
#define ldebug(_f...) logger->debug(_f)

__dead void
usage(void)
{
	extern char *__progname;
	fprintf(stderr,
	    "usage: %s [-d] [-p path] [-s socket] [-U user] [-u user]\n",
	    __progname);
	exit(1);
}

struct timeval		timeout = { TIMEOUT_DEFAULT, 0 };
struct slowcgi_proc	slowcgi_proc;
int			debug = 0;
int			on = 1;
char			*fcgi_socket = "/var/www/run/slowcgi.sock";

int
main(int argc, char *argv[])
{
	extern char *__progname;
	struct listener	*l = NULL;
	struct passwd	*pw;
	struct stat	 sb;
	int		 c, fd;
	const char	*chrootpath = NULL;
	const char	*sock_user = SLOWCGI_USER;
	const char	*slowcgi_user = SLOWCGI_USER;

	/*
	 * Ensure we have fds 0-2 open so that we have no fd overlaps
	 * in exec_cgi() later. Just exit on error, we don't have enough
	 * fds open to output an error message anywhere.
	 */
	for (c=0; c < 3; c++) {
		if (fstat(c, &sb) == -1) {
			if ((fd = open("/dev/null", O_RDWR)) != -1) {
				if (dup2(fd, c) == -1)
					exit(1);
				if (fd > c)
					close(fd);
			} else
				exit(1);
		}
	}

	while ((c = getopt(argc, argv, "dp:s:U:u:")) != -1) {
		switch (c) {
		case 'd':
			debug++;
			break;
		case 'p':
			chrootpath = optarg;
			break;
		case 's':
			fcgi_socket = optarg;
			break;
		case 'U':
			sock_user = optarg;
			break;
		case 'u':
			slowcgi_user = optarg;
			break;
		default:
			usage();
			/* NOTREACHED */
		}
	}

	if (geteuid() != 0)
		errx(1, "need root privileges");

	if (!debug && daemon(0, 0) == -1)
		err(1, "daemon");

	if (!debug) {
		openlog(__progname, LOG_PID|LOG_NDELAY, LOG_DAEMON);
		logger = &syslogger;
	}

	ldebug("sock_user: %s", sock_user);
	pw = getpwnam(sock_user);
	if (pw == NULL)
		lerrx(1, "no %s user", sock_user);

	fd = slowcgi_listen(fcgi_socket, pw);

	ldebug("slowcgi_user: %s", slowcgi_user);
	pw = getpwnam(slowcgi_user);
	if (pw == NULL)
		lerrx(1, "no %s user", slowcgi_user);

	if (chrootpath == NULL)
		chrootpath = pw->pw_dir;

	if (chroot(chrootpath) == -1)
		lerr(1, "chroot(%s)", chrootpath);

	ldebug("chroot: %s", chrootpath);

	if (chdir("/") == -1)
		lerr(1, "chdir(/)");

	if (setgroups(1, &pw->pw_gid) ||
	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
		lerr(1, "unable to revoke privs");

#ifdef __OpenBSD__
	if (pledge("stdio rpath unix proc exec", NULL) == -1)
		lerr(1, "pledge");
#endif

	SLIST_INIT(&slowcgi_proc.requests);
	event_init();

	l = calloc(1, sizeof(*l));
	if (l == NULL)
		lerr(1, "listener ev alloc");

	event_set(&l->ev, fd, EV_READ | EV_PERSIST, slowcgi_accept, l);
	event_add(&l->ev, NULL);
	evtimer_set(&l->pause, slowcgi_paused, l);

	signal_set(&slowcgi_proc.ev_sigchld, SIGCHLD, slowcgi_sig_handler,
	    &slowcgi_proc);
	signal(SIGPIPE, SIG_IGN);

	signal_add(&slowcgi_proc.ev_sigchld, NULL);

	event_dispatch();
	return (0);
}

int
slowcgi_listen(char *path, struct passwd *pw)
{
	struct sockaddr_un	 sun;
	mode_t			 old_umask;
	int			 fd;

	if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
	    0)) == -1)
		lerr(1, "slowcgi_listen: socket");

	bzero(&sun, sizeof(sun));
	sun.sun_family = AF_UNIX;
	if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
	    sizeof(sun.sun_path))
		lerrx(1, "socket path too long");

	if (unlink(path) == -1)
		if (errno != ENOENT)
			lerr(1, "slowcgi_listen: unlink %s", path);

	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);

	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1)
		lerr(1,"slowcgi_listen: bind: %s", path);

	umask(old_umask);

	if (chown(path, pw->pw_uid, pw->pw_gid) == -1)
		lerr(1, "slowcgi_listen: chown: %s", path);

	if (listen(fd, 5) == -1)
		lerr(1, "listen");

	ldebug("socket: %s", path);
	return fd;
}

void
slowcgi_paused(int fd, short events, void *arg)
{
	struct listener	*l = arg;
	event_add(&l->ev, NULL);
}

int
accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
    int reserve, int *counter)
{
	int ret;
	if (getdtablecount() + reserve +
	    ((*counter + 1) * FD_NEEDED) >= getdtablesize()) {
		ldebug("inflight fds exceeded");
		errno = EMFILE;
		return -1;
	}

	if ((ret = accept4(sockfd, addr, addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC))
	    > -1) {
		(*counter)++;
		ldebug("inflight incremented, now %d", *counter);
	}
	return ret;
}

void
slowcgi_accept(int fd, short events, void *arg)
{
	struct listener		*l;
	struct sockaddr_storage	 ss;
	struct timeval		 backoff;
	struct request		*c;
	struct requests		*requests;
	socklen_t		 len;
	int			 s;

	l = arg;
	backoff.tv_sec = 1;
	backoff.tv_usec = 0;
	c = NULL;

	len = sizeof(ss);
	if ((s = accept_reserve(fd, (struct sockaddr *)&ss,
	    &len, FD_RESERVE, &cgi_inflight)) == -1) {
		switch (errno) {
		case EINTR:
		case EWOULDBLOCK:
		case ECONNABORTED:
			return;
		case EMFILE:
		case ENFILE:
			event_del(&l->ev);
			evtimer_add(&l->pause, &backoff);
			return;
		default:
			lerr(1, "accept");
		}
	}

	c = calloc(1, sizeof(*c));
	if (c == NULL) {
		lwarn("cannot calloc request");
		close(s);
		cgi_inflight--;
		return;
	}
	requests = calloc(1, sizeof(*requests));
	if (requests == NULL) {
		lwarn("cannot calloc requests");
		close(s);
		cgi_inflight--;
		free(c);
		return;
	}
	c->fd = s;
	c->buf_pos = 0;
	c->buf_len = 0;
	c->request_started = 0;
	c->stdin_fd_closed = c->stdout_fd_closed = c->stderr_fd_closed = 0;
	c->inflight_fds_accounted = 0;
	TAILQ_INIT(&c->response_head);
	TAILQ_INIT(&c->stdin_head);

	event_set(&c->ev, s, EV_READ | EV_PERSIST, slowcgi_request, c);
	event_add(&c->ev, NULL);
	event_set(&c->resp_ev, s, EV_WRITE | EV_PERSIST, slowcgi_response, c);
	evtimer_set(&c->tmo, slowcgi_timeout, c);
	evtimer_add(&c->tmo, &timeout);
	requests->request = c;
	SLIST_INSERT_HEAD(&slowcgi_proc.requests, requests, entry);
}

void
slowcgi_timeout(int fd, short events, void *arg)
{
	cleanup_request((struct request*) arg);
}

void
slowcgi_sig_handler(int sig, short event, void *arg)
{
	struct request		*c;
	struct requests		*ncs;
	struct slowcgi_proc	*p;
	pid_t			 pid;
	int			 status;

	p = arg;

	switch (sig) {
	case SIGCHLD:
		while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
			c = NULL;
			SLIST_FOREACH(ncs, &p->requests, entry)
				if (ncs->request->script_pid == pid) {
					c = ncs->request;
					break;
				}
			if (c == NULL) {
				lwarnx("caught exit of unknown child %i", pid);
				continue;
			}

			if (WIFSIGNALED(status))
				c->script_status = WTERMSIG(status);
			else
				c->script_status = WEXITSTATUS(status);

			if (c->script_flags == (STDOUT_DONE | STDERR_DONE))
				create_end_record(c);
			c->script_flags |= SCRIPT_DONE;

			ldebug("wait: %s", c->script_name);
		}
		if (pid == -1 && errno != ECHILD)
			lwarn("waitpid");
		break;
	default:
		lerr(1, "unexpected signal: %d", sig);
		break;
	}
}

void
slowcgi_add_response(struct request *c, struct fcgi_response *resp)
{
	struct fcgi_record_header	*header;
	size_t				 padded_len;

	header = (struct fcgi_record_header*)resp->data;

	/* The FastCGI spec suggests to align the output buffer */
	padded_len = FCGI_ALIGN(resp->data_len);
	if (padded_len > resp->data_len) {
		/* There should always be FCGI_PADDING_SIZE bytes left */
		if (padded_len > FCGI_RECORD_SIZE)
			lerr(1, "response too long");
		header->padding_len = padded_len - resp->data_len;
		resp->data_len = padded_len;
	}

	TAILQ_INSERT_TAIL(&c->response_head, resp, entry);
	event_add(&c->resp_ev, NULL);
}

void
slowcgi_response(int fd, short events, void *arg)
{
	struct request			*c;
	struct fcgi_record_header	*header;
	struct fcgi_response		*resp;
	ssize_t				 n;

	c = arg;

	while ((resp = TAILQ_FIRST(&c->response_head))) {
		header = (struct fcgi_record_header*) resp->data;
		if (debug > 1)
			dump_fcgi_record("resp ", header);

		n = write(fd, resp->data + resp->data_pos, resp->data_len);
		if (n == -1) {
			if (errno == EAGAIN || errno == EINTR)
				return;
			cleanup_request(c);
			return;
		}
		resp->data_pos += n;
		resp->data_len -= n;
		if (resp->data_len == 0) {
			TAILQ_REMOVE(&c->response_head, resp, entry);
			free(resp);
		}
	}

	if (TAILQ_EMPTY(&c->response_head)) {
		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
		    SCRIPT_DONE))
			cleanup_request(c);
		else
			event_del(&c->resp_ev);
	}
}

void
slowcgi_request(int fd, short events, void *arg)
{
	struct request	*c;
	ssize_t		 n;
	size_t		 parsed;

	c = arg;

	n = read(fd, c->buf + c->buf_pos + c->buf_len,
	    FCGI_RECORD_SIZE - c->buf_pos-c->buf_len);

	switch (n) {
	case -1:
		switch (errno) {
		case EINTR:
		case EAGAIN:
			return;
		default:
			goto fail;
		}
		break;

	case 0:
		ldebug("closed connection");
		goto fail;
	default:
		break;
	}

	c->buf_len += n;

	/*
	 * Parse the records as they are received. Per the FastCGI
	 * specification, the server need only receive the FastCGI
	 * parameter records in full; it is free to begin execution
	 * at that point, which is what happens here.
	 */
	do {
		parsed = parse_record(c->buf + c->buf_pos, c->buf_len, c);
		c->buf_pos += parsed;
		c->buf_len -= parsed;
	} while (parsed > 0 && c->buf_len > 0);

	/* Make space for further reads */
	if (c->buf_len > 0) {
		bcopy(c->buf + c->buf_pos, c->buf, c->buf_len);
		c->buf_pos = 0;
	}
	return;
fail:
	cleanup_request(c);
}

void
parse_begin_request(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
{
	/* XXX -- FCGI_CANT_MPX_CONN */
	if (c->request_started) {
		lwarnx("unexpected FCGI_BEGIN_REQUEST, ignoring");
		return;
	}

	if (n != sizeof(struct fcgi_begin_request_body)) {
		lwarnx("wrong size %d != %lu", n,
		    sizeof(struct fcgi_begin_request_body));
		return;
	}

	c->request_started = 1;

	c->id = id;
	SLIST_INIT(&c->env);
	c->env_count = 0;
}

void
parse_params(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
{
	struct env_val			*env_entry;
	uint32_t			 name_len, val_len;

	if (!c->request_started) {
		lwarnx("FCGI_PARAMS without FCGI_BEGIN_REQUEST, ignoring");
		return;
	}

	if (c->id != id) {
		lwarnx("unexpected id, ignoring");
		return;
	}

	/*
	 * If this is the last FastCGI parameter record,
	 * begin execution of the CGI script.
	 */
	if (n == 0) {
		exec_cgi(c);
		return;
	}

	while (n > 0) {
		if (buf[0] >> 7 == 0) {
			name_len = buf[0];
			n--;
			buf++;
		} else {
			if (n > 3) {
				name_len = ((buf[0] & 0x7f) << 24) +
				    (buf[1] << 16) + (buf[2] << 8) + buf[3];
				n -= 4;
				buf += 4;
			} else
				return;
		}

		if (n > 0) {
			if (buf[0] >> 7 == 0) {
				val_len = buf[0];
				n--;
				buf++;
			} else {
				if (n > 3) {
					val_len = ((buf[0] & 0x7f) << 24) +
					    (buf[1] << 16) + (buf[2] << 8) +
					     buf[3];
					n -= 4;
					buf += 4;
				} else
					return;
			}
		} else
			return;

		if (n < name_len + val_len)
			return;

		if ((env_entry = malloc(sizeof(struct env_val))) == NULL) {
			lwarnx("cannot allocate env_entry");
			return;
		}

		if ((env_entry->val = calloc(sizeof(char), name_len + val_len +
		    2)) == NULL) {
			lwarnx("cannot allocate env_entry->val");
			free(env_entry);
			return;
		}

		bcopy(buf, env_entry->val, name_len);
		buf += name_len;
		n -= name_len;

		env_entry->val[name_len] = '\0';
		if (val_len < PATH_MAX && strcmp(env_entry->val,
		    "SCRIPT_NAME") == 0 && c->script_name[0] == '\0') {
			bcopy(buf, c->script_name, val_len);
			c->script_name[val_len] = '\0';
		} else if (val_len < PATH_MAX && strcmp(env_entry->val,
		    "SCRIPT_FILENAME") == 0) {
			bcopy(buf, c->script_name, val_len);
			c->script_name[val_len] = '\0';
		}
		env_entry->val[name_len] = '=';

		bcopy(buf, (env_entry->val) + name_len + 1, val_len);
		buf += val_len;
		n -= val_len;

		SLIST_INSERT_HEAD(&c->env, env_entry, entry);
		ldebug("env[%d], %s", c->env_count, env_entry->val);
		c->env_count++;
	}
}

void
parse_stdin(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
{
	struct fcgi_stdin	*node;

	if (c->id != id) {
		lwarnx("unexpected id, ignoring");
		return;
	}

	if ((node = calloc(1, sizeof(struct fcgi_stdin))) == NULL) {
		lwarnx("cannot calloc stdin node");
		return;
	}

	bcopy(buf, node->data, n);
	node->data_pos = 0;
	node->data_len = n;

	TAILQ_INSERT_TAIL(&c->stdin_head, node, entry);

	if (event_initialized(&c->script_stdin_ev))
		event_add(&c->script_stdin_ev, NULL);
}

size_t
parse_record(uint8_t *buf, size_t n, struct request *c)
{
	struct fcgi_record_header	*h;

	if (n < sizeof(struct fcgi_record_header))
		return (0);

	h = (struct fcgi_record_header*) buf;

	if (debug > 1)
		dump_fcgi_record("", h);

	if (n < sizeof(struct fcgi_record_header) + ntohs(h->content_len)
	    + h->padding_len)
		return (0);

	if (h->version != 1)
		lerrx(1, "wrong version");

	switch (h->type) {
	case FCGI_BEGIN_REQUEST:
		parse_begin_request(buf + sizeof(struct fcgi_record_header),
		    ntohs(h->content_len), c, ntohs(h->id));
		break;
	case FCGI_PARAMS:
		parse_params(buf + sizeof(struct fcgi_record_header),
		    ntohs(h->content_len), c, ntohs(h->id));
		break;
	case FCGI_STDIN:
		parse_stdin(buf + sizeof(struct fcgi_record_header),
		    ntohs(h->content_len), c, ntohs(h->id));
		break;
	default:
		lwarnx("unimplemented type %d", h->type);
		break;
	}

	return (sizeof(struct fcgi_record_header) + ntohs(h->content_len)
	    + h->padding_len);
}

/*
 * Fork a new CGI process to handle the request, translating
 * between FastCGI parameter records and CGI's environment variables,
 * as well as between the CGI process' stdin/stdout and the
 * corresponding FastCGI records.
 */
void
exec_cgi(struct request *c)
{
	struct env_val	*env_entry;
	int		 s_in[2], s_out[2], s_err[2], i;
	pid_t		 pid;
	char		*argv[2];
	char		**env;
	char		*path;

	i = 0;

	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_in) == -1)
		lerr(1, "socketpair");
	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_out) == -1)
		lerr(1, "socketpair");
	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s_err) == -1)
		lerr(1, "socketpair");
	cgi_inflight--;
	c->inflight_fds_accounted = 1;
	ldebug("fork: %s", c->script_name);

	switch (pid = fork()) {
	case -1:
		c->script_status = errno;

		lwarn("fork");

		close(s_in[0]);
		close(s_out[0]);
		close(s_err[0]);

		close(s_in[1]);
		close(s_out[1]);
		close(s_err[1]);

		c->stdin_fd_closed = c->stdout_fd_closed =
		    c->stderr_fd_closed = 1;
		c->script_flags = (STDOUT_DONE | STDERR_DONE | SCRIPT_DONE);

		create_end_record(c);
		return;
	case 0:
		/* Child process */
#ifdef __OpenBSD__
		if (pledge("stdio rpath exec", NULL) == -1)
			lerr(1, "pledge");
#endif
		close(s_in[0]);
		close(s_out[0]);
		close(s_err[0]);

		if (dup2(s_in[1], STDIN_FILENO) == -1)
			_exit(1);
		if (dup2(s_out[1], STDOUT_FILENO) == -1)
			_exit(1);
		if (dup2(s_err[1], STDERR_FILENO) == -1)
			_exit(1);

		close(s_in[1]);
		close(s_out[1]);
		close(s_err[1]);

		signal(SIGPIPE, SIG_DFL);

		path = strrchr(c->script_name, '/');
		if (path != NULL) {
			if (path != c->script_name) {
				*path = '\0';
				if (chdir(c->script_name) == -1)
					lwarn("cannot chdir to %s",
					    c->script_name);
				*path = '/';
			} else
				if (chdir("/") == -1)
					lwarn("cannot chdir to /");
		}

		argv[0] = c->script_name;
		argv[1] = NULL;
		if ((env = calloc(c->env_count + 1, sizeof(char*))) == NULL)
			_exit(1);
		SLIST_FOREACH(env_entry, &c->env, entry)
			env[i++] = env_entry->val;
		env[i++] = NULL;
		execve(c->script_name, argv, env);
		lwarn("execve %s", c->script_name);
		_exit(1);

	}

	/* Parent process*/
	close(s_in[1]);
	close(s_out[1]);
	close(s_err[1]);

	fcntl(s_in[0], F_SETFD, FD_CLOEXEC);
	fcntl(s_out[0], F_SETFD, FD_CLOEXEC);
	fcntl(s_err[0], F_SETFD, FD_CLOEXEC);

	if (ioctl(s_in[0], FIONBIO, &on) == -1)
		lerr(1, "script ioctl(FIONBIO)");
	if (ioctl(s_out[0], FIONBIO, &on) == -1)
		lerr(1, "script ioctl(FIONBIO)");
	if (ioctl(s_err[0], FIONBIO, &on) == -1)
		lerr(1, "script ioctl(FIONBIO)");

	c->script_pid = pid;
	event_set(&c->script_stdin_ev, s_in[0], EV_WRITE | EV_PERSIST,
	    script_out, c);
	event_add(&c->script_stdin_ev, NULL);
	event_set(&c->script_ev, s_out[0], EV_READ | EV_PERSIST,
	    script_std_in, c);
	event_add(&c->script_ev, NULL);
	event_set(&c->script_err_ev, s_err[0], EV_READ | EV_PERSIST,
	    script_err_in, c);
	event_add(&c->script_err_ev, NULL);
}

void
create_end_record(struct request *c)
{
	struct fcgi_response		*resp;
	struct fcgi_record_header	*header;
	struct fcgi_end_request_body	*end_request;

	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
		lwarnx("cannot malloc fcgi_response");
		return;
	}
	header = (struct fcgi_record_header*) resp->data;
	header->version = 1;
	header->type = FCGI_END_REQUEST;
	header->id = htons(c->id);
	header->content_len = htons(sizeof(struct
	    fcgi_end_request_body));
	header->padding_len = 0;
	header->reserved = 0;
	end_request = (struct fcgi_end_request_body *) (resp->data +
	    sizeof(struct fcgi_record_header));
	end_request->app_status = htonl(c->script_status);
	end_request->protocol_status = FCGI_REQUEST_COMPLETE;
	end_request->reserved[0] = 0;
	end_request->reserved[1] = 0;
	end_request->reserved[2] = 0;
	resp->data_pos = 0;
	resp->data_len = sizeof(struct fcgi_end_request_body) +
	    sizeof(struct fcgi_record_header);
	slowcgi_add_response(c, resp);
}

void
script_in(int fd, struct event *ev, struct request *c, uint8_t type)
{
	struct fcgi_response		*resp;
	struct fcgi_record_header	*header;
	ssize_t				 n;

	if ((resp = calloc(1, sizeof(struct fcgi_response))) == NULL) {
		lwarnx("cannot malloc fcgi_response");
		return;
	}
	header = (struct fcgi_record_header*) resp->data;
	header->version = 1;
	header->type = type;
	header->id = htons(c->id);
	header->padding_len = 0;
	header->reserved = 0;

	n = read(fd, resp->data + sizeof(struct fcgi_record_header),
	    FCGI_CONTENT_SIZE);

	if (n == -1) {
		switch (errno) {
		case EINTR:
		case EAGAIN:
			free(resp);
			return;
		default:
			n = 0; /* fake empty FCGI_STD{OUT,ERR} response */
		}
	}
	header->content_len = htons(n);
	resp->data_pos = 0;
	resp->data_len = n + sizeof(struct fcgi_record_header);
	slowcgi_add_response(c, resp);

	if (n == 0) {
		if (type == FCGI_STDOUT)
			c->script_flags |= STDOUT_DONE;
		else
			c->script_flags |= STDERR_DONE;

		if (c->script_flags == (STDOUT_DONE | STDERR_DONE |
		    SCRIPT_DONE)) {
			create_end_record(c);
		}
		event_del(ev);
		close(fd);
		if (type == FCGI_STDOUT)
			c->stdout_fd_closed = 1;
		else
			c->stderr_fd_closed = 1;
	}
}

void
script_std_in(int fd, short events, void *arg)
{
	struct request *c = arg;
	script_in(fd, &c->script_ev, c, FCGI_STDOUT);
}

void
script_err_in(int fd, short events, void *arg)
{
	struct request *c = arg;
	script_in(fd, &c->script_err_ev, c, FCGI_STDERR);
}

void
script_out(int fd, short events, void *arg)
{
	struct request		*c;
	struct fcgi_stdin	*node;
	ssize_t			 n;

	c = arg;

	while ((node = TAILQ_FIRST(&c->stdin_head))) {
		if (node->data_len == 0) { /* end of stdin marker */
			close(fd);
			c->stdin_fd_closed = 1;
			break;
		}
		n = write(fd, node->data + node->data_pos, node->data_len);
		if (n == -1) {
			if (errno == EAGAIN || errno == EINTR)
				return;
			event_del(&c->script_stdin_ev);
			return;
		}
		node->data_pos += n;
		node->data_len -= n;
		if (node->data_len == 0) {
			TAILQ_REMOVE(&c->stdin_head, node, entry);
			free(node);
		}
	}
	event_del(&c->script_stdin_ev);
}

void
cleanup_request(struct request *c)
{
	struct fcgi_response	*resp;
	struct fcgi_stdin	*stdin_node;
	struct env_val		*env_entry;
	struct requests		*ncs, *tcs;

	evtimer_del(&c->tmo);
	if (event_initialized(&c->ev))
		event_del(&c->ev);
	if (event_initialized(&c->resp_ev))
		event_del(&c->resp_ev);
	if (event_initialized(&c->script_ev)) {
		if (!c->stdout_fd_closed)
			close(EVENT_FD(&c->script_ev));
		event_del(&c->script_ev);
	}
	if (event_initialized(&c->script_err_ev)) {
		if (!c->stderr_fd_closed)
			close(EVENT_FD(&c->script_err_ev));
		event_del(&c->script_err_ev);
	}
	if (event_initialized(&c->script_stdin_ev)) {
		if (!c->stdin_fd_closed)
			close(EVENT_FD(&c->script_stdin_ev));
		event_del(&c->script_stdin_ev);
	}
	close(c->fd);
	while (!SLIST_EMPTY(&c->env)) {
		env_entry = SLIST_FIRST(&c->env);
		SLIST_REMOVE_HEAD(&c->env, entry);
		free(env_entry->val);
		free(env_entry);
	}

	while ((resp = TAILQ_FIRST(&c->response_head))) {
		TAILQ_REMOVE(&c->response_head, resp, entry);
		free(resp);
	}
	while ((stdin_node = TAILQ_FIRST(&c->stdin_head))) {
		TAILQ_REMOVE(&c->stdin_head, stdin_node, entry);
		free(stdin_node);
	}
	SLIST_FOREACH_SAFE(ncs, &slowcgi_proc.requests, entry, tcs) {
		if (ncs->request == c) {
			SLIST_REMOVE(&slowcgi_proc.requests, ncs, requests,
			    entry);
			free(ncs);
			break;
		}
	}
	if (! c->inflight_fds_accounted)
		cgi_inflight--;
	free(c);
}

void
dump_fcgi_record(const char *p, struct fcgi_record_header *h)
{
	dump_fcgi_record_header(p, h);

	if (h->type == FCGI_BEGIN_REQUEST)
		dump_fcgi_begin_request_body(p,
		    (struct fcgi_begin_request_body *)(h + 1));
	else if (h->type == FCGI_END_REQUEST)
		dump_fcgi_end_request_body(p,
		    (struct fcgi_end_request_body *)(h + 1));
}

void
dump_fcgi_record_header(const char* p, struct fcgi_record_header *h)
{
	ldebug("%sversion:         %d", p, h->version);
	ldebug("%stype:            %d", p, h->type);
	ldebug("%srequestId:       %d", p, ntohs(h->id));
	ldebug("%scontentLength:   %d", p, ntohs(h->content_len));
	ldebug("%spaddingLength:   %d", p, h->padding_len);
	ldebug("%sreserved:        %d", p, h->reserved);
}

void
dump_fcgi_begin_request_body(const char *p, struct fcgi_begin_request_body *b)
{
	ldebug("%srole             %d", p, ntohs(b->role));
	ldebug("%sflags            %d", p, b->flags);
}

void
dump_fcgi_end_request_body(const char *p, struct fcgi_end_request_body *b)
{
	ldebug("%sappStatus:       %d", p, ntohl(b->app_status));
	ldebug("%sprotocolStatus:  %d", p, b->protocol_status);
}

void
syslog_vstrerror(int e, int priority, const char *fmt, va_list ap)
{
	char *s;

	if (vasprintf(&s, fmt, ap) == -1) {
		syslog(LOG_EMERG, "unable to alloc in syslog_vstrerror");
		exit(1);
	}
	syslog(priority, "%s: %s", s, strerror(e));
	free(s);
}

__dead void
syslog_err(int ecode, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	syslog_vstrerror(errno, LOG_CRIT, fmt, ap);
	va_end(ap);
	exit(ecode);
}

__dead void
syslog_errx(int ecode, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vsyslog(LOG_CRIT, fmt, ap);
	va_end(ap);
	exit(ecode);
}

void
syslog_warn(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	syslog_vstrerror(errno, LOG_ERR, fmt, ap);
	va_end(ap);
}

void
syslog_warnx(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vsyslog(LOG_ERR, fmt, ap);
	va_end(ap);
}

void
syslog_info(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vsyslog(LOG_INFO, fmt, ap);
	va_end(ap);
}

void
syslog_debug(const char *fmt, ...)
{
	va_list ap;

	if (!debug)
		return;

	va_start(ap, fmt);
	vsyslog(LOG_DEBUG, fmt, ap);
	va_end(ap);
}