server_fcgi.c revision 1.92
1/*	$OpenBSD: server_fcgi.c,v 1.92 2022/08/12 06:41:41 op Exp $	*/
2
3/*
4 * Copyright (c) 2014 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/time.h>
21#include <sys/socket.h>
22#include <sys/un.h>
23
24#include <netinet/in.h>
25#include <arpa/inet.h>
26
27#include <limits.h>
28#include <errno.h>
29#include <stdlib.h>
30#include <string.h>
31#include <stdio.h>
32#include <time.h>
33#include <ctype.h>
34#include <event.h>
35#include <unistd.h>
36
37#include "httpd.h"
38#include "http.h"
39
40#define FCGI_PADDING_SIZE	 255
41#define FCGI_RECORD_SIZE	 \
42    (sizeof(struct fcgi_record_header) + FCGI_CONTENT_SIZE + FCGI_PADDING_SIZE)
43
44#define FCGI_BEGIN_REQUEST	 1
45#define FCGI_ABORT_REQUEST	 2
46#define FCGI_END_REQUEST	 3
47#define FCGI_PARAMS		 4
48#define FCGI_STDIN		 5
49#define FCGI_STDOUT		 6
50#define FCGI_STDERR		 7
51#define FCGI_DATA		 8
52#define FCGI_GET_VALUES		 9
53#define FCGI_GET_VALUES_RESULT	10
54#define FCGI_UNKNOWN_TYPE	11
55#define FCGI_MAXTYPE		(FCGI_UNKNOWN_TYPE)
56
57#define FCGI_RESPONDER		 1
58
59struct fcgi_record_header {
60	uint8_t		version;
61	uint8_t		type;
62	uint16_t	id;
63	uint16_t	content_len;
64	uint8_t		padding_len;
65	uint8_t		reserved;
66} __packed;
67
68struct fcgi_begin_request_body {
69	uint16_t	role;
70	uint8_t		flags;
71	uint8_t		reserved[5];
72} __packed;
73
74struct server_fcgi_param {
75	int		total_len;
76	uint8_t		buf[FCGI_RECORD_SIZE];
77};
78
79int	server_fcgi_header(struct client *, unsigned int);
80void	server_fcgi_error(struct bufferevent *, short, void *);
81void	server_fcgi_read(struct bufferevent *, void *);
82int	server_fcgi_writeheader(struct client *, struct kv *, void *);
83int	server_fcgi_writechunk(struct client *);
84int	server_fcgi_getheaders(struct client *);
85int	fcgi_add_param(struct server_fcgi_param *, const char *, const char *,
86	    struct client *);
87
88int
89server_fcgi(struct httpd *env, struct client *clt)
90{
91	struct server_fcgi_param	 param;
92	struct server_config		*srv_conf = clt->clt_srv_conf;
93	struct http_descriptor		*desc = clt->clt_descreq;
94	struct fcgi_record_header	*h;
95	struct fcgi_begin_request_body	*begin;
96	struct fastcgi_param		*fcgiparam;
97	char				 hbuf[HOST_NAME_MAX+1];
98	size_t				 scriptlen;
99	int				 pathlen;
100	int				 fd = -1, ret;
101	const char			*stripped, *alias, *errstr = NULL;
102	char				*query_alias, *str, *script = NULL;
103
104	if ((fd = socket(srv_conf->fastcgi_ss.ss_family,
105	    SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1)
106		goto fail;
107	if ((connect(fd, (struct sockaddr *) &srv_conf->fastcgi_ss,
108	    srv_conf->fastcgi_ss.ss_len)) == -1) {
109		if (errno != EINPROGRESS)
110			goto fail;
111	}
112
113	memset(hbuf, 0, sizeof(hbuf));
114	clt->clt_fcgi.state = FCGI_READ_HEADER;
115	clt->clt_fcgi.toread = sizeof(struct fcgi_record_header);
116	clt->clt_fcgi.status = 200;
117	clt->clt_fcgi.headersdone = 0;
118	clt->clt_fcgi.headerssent = 0;
119
120	if (clt->clt_srvevb != NULL)
121		evbuffer_free(clt->clt_srvevb);
122
123	clt->clt_srvevb = evbuffer_new();
124	if (clt->clt_srvevb == NULL) {
125		errstr = "failed to allocate evbuffer";
126		goto fail;
127	}
128
129	close(clt->clt_fd);
130	clt->clt_fd = fd;
131
132	if (clt->clt_srvbev != NULL)
133		bufferevent_free(clt->clt_srvbev);
134
135	clt->clt_srvbev_throttled = 0;
136	clt->clt_srvbev = bufferevent_new(fd, server_fcgi_read,
137	    NULL, server_fcgi_error, clt);
138	if (clt->clt_srvbev == NULL) {
139		errstr = "failed to allocate fcgi buffer event";
140		goto fail;
141	}
142
143	memset(&param, 0, sizeof(param));
144
145	h = (struct fcgi_record_header *)&param.buf;
146	h->version = 1;
147	h->type = FCGI_BEGIN_REQUEST;
148	h->id = htons(1);
149	h->content_len = htons(sizeof(struct fcgi_begin_request_body));
150	h->padding_len = 0;
151
152	begin = (struct fcgi_begin_request_body *)&param.buf[sizeof(struct
153	    fcgi_record_header)];
154	begin->role = htons(FCGI_RESPONDER);
155
156	if (bufferevent_write(clt->clt_srvbev, &param.buf,
157	    sizeof(struct fcgi_record_header) +
158	    sizeof(struct fcgi_begin_request_body)) == -1) {
159		errstr = "failed to write to evbuffer";
160		goto fail;
161	}
162
163	h->type = FCGI_PARAMS;
164	h->content_len = param.total_len = 0;
165
166	alias = desc->http_path_alias != NULL
167	    ? desc->http_path_alias
168	    : desc->http_path;
169
170	query_alias = desc->http_query_alias != NULL
171	    ? desc->http_query_alias
172	    : desc->http_query;
173
174	stripped = server_root_strip(alias, srv_conf->strip);
175	if ((pathlen = asprintf(&script, "%s%s", srv_conf->root, stripped))
176	    == -1) {
177		errstr = "failed to get script name";
178		goto fail;
179	}
180
181	scriptlen = path_info(script);
182	/*
183	 * no part of root should show up in PATH_INFO.
184	 * therefore scriptlen should be >= strlen(root)
185	 */
186	if (scriptlen < strlen(srv_conf->root))
187		scriptlen = strlen(srv_conf->root);
188	if ((int)scriptlen < pathlen) {
189		if (fcgi_add_param(&param, "PATH_INFO",
190		    script + scriptlen, clt) == -1) {
191			errstr = "failed to encode param";
192			goto fail;
193		}
194		script[scriptlen] = '\0';
195	} else {
196		/* RFC 3875 mandates that PATH_INFO is empty if not set */
197		if (fcgi_add_param(&param, "PATH_INFO", "", clt) == -1) {
198			errstr = "failed to encode param";
199			goto fail;
200		}
201	}
202
203	/*
204	 * calculate length of http SCRIPT_NAME:
205	 * add length of stripped prefix,
206	 * subtract length of prepended local root
207	 */
208	scriptlen += (stripped - alias) - strlen(srv_conf->root);
209	if ((str = strndup(alias, scriptlen)) == NULL)
210		goto fail;
211	ret = fcgi_add_param(&param, "SCRIPT_NAME", str, clt);
212	free(str);
213	if (ret == -1) {
214		errstr = "failed to encode param";
215		goto fail;
216	}
217	if (fcgi_add_param(&param, "SCRIPT_FILENAME", server_root_strip(script,
218	    srv_conf->fcgistrip), clt) == -1) {
219		errstr = "failed to encode param";
220		goto fail;
221	}
222
223	if (query_alias) {
224		if (fcgi_add_param(&param, "QUERY_STRING", query_alias,
225		    clt) == -1) {
226			errstr = "failed to encode param";
227			goto fail;
228		}
229	} else if (fcgi_add_param(&param, "QUERY_STRING", "", clt) == -1) {
230		errstr = "failed to encode param";
231		goto fail;
232	}
233
234	if (fcgi_add_param(&param, "DOCUMENT_ROOT", server_root_strip(
235	    srv_conf->root, srv_conf->fcgistrip), clt) == -1) {
236		errstr = "failed to encode param";
237		goto fail;
238	}
239	if (fcgi_add_param(&param, "DOCUMENT_URI", alias,
240	    clt) == -1) {
241		errstr = "failed to encode param";
242		goto fail;
243	}
244	if (fcgi_add_param(&param, "GATEWAY_INTERFACE", "CGI/1.1",
245	    clt) == -1) {
246		errstr = "failed to encode param";
247		goto fail;
248	}
249
250	if (srv_conf->flags & SRVFLAG_AUTH) {
251		if (fcgi_add_param(&param, "REMOTE_USER",
252		    clt->clt_remote_user, clt) == -1) {
253			errstr = "failed to encode param";
254			goto fail;
255		}
256	}
257
258	/* Add HTTP_* headers */
259	if (server_headers(clt, desc, server_fcgi_writeheader, &param) == -1) {
260		errstr = "failed to encode param";
261		goto fail;
262	}
263
264	if (srv_conf->flags & SRVFLAG_TLS) {
265		if (fcgi_add_param(&param, "HTTPS", "on", clt) == -1) {
266			errstr = "failed to encode param";
267			goto fail;
268		}
269		if (srv_conf->tls_flags != 0 && fcgi_add_param(&param,
270		    "TLS_PEER_VERIFY", printb_flags(srv_conf->tls_flags,
271		    TLSFLAG_BITS), clt) == -1) {
272			errstr = "failed to encode param";
273			goto fail;
274		}
275	}
276
277	TAILQ_FOREACH(fcgiparam, &srv_conf->fcgiparams, entry) {
278		if (fcgi_add_param(&param, fcgiparam->name, fcgiparam->value,
279		    clt) == -1) {
280			errstr = "failed to encode param";
281			goto fail;
282		}
283	}
284
285	(void)print_host(&clt->clt_ss, hbuf, sizeof(hbuf));
286	if (fcgi_add_param(&param, "REMOTE_ADDR", hbuf, clt) == -1) {
287		errstr = "failed to encode param";
288		goto fail;
289	}
290
291	(void)snprintf(hbuf, sizeof(hbuf), "%d", ntohs(clt->clt_port));
292	if (fcgi_add_param(&param, "REMOTE_PORT", hbuf, clt) == -1) {
293		errstr = "failed to encode param";
294		goto fail;
295	}
296
297	if (fcgi_add_param(&param, "REQUEST_METHOD",
298	    server_httpmethod_byid(desc->http_method), clt) == -1) {
299		errstr = "failed to encode param";
300		goto fail;
301	}
302
303	if (!desc->http_query) {
304		if (fcgi_add_param(&param, "REQUEST_URI", desc->http_path_orig,
305		    clt) == -1) {
306			errstr = "failed to encode param";
307			goto fail;
308		}
309	} else {
310		if (asprintf(&str, "%s?%s", desc->http_path_orig,
311		    desc->http_query) == -1) {
312			errstr = "failed to encode param";
313			goto fail;
314		}
315		ret = fcgi_add_param(&param, "REQUEST_URI", str, clt);
316		free(str);
317		if (ret == -1) {
318			errstr = "failed to encode param";
319			goto fail;
320		}
321	}
322
323	(void)print_host(&clt->clt_srv_ss, hbuf, sizeof(hbuf));
324	if (fcgi_add_param(&param, "SERVER_ADDR", hbuf, clt) == -1) {
325		errstr = "failed to encode param";
326		goto fail;
327	}
328
329	(void)snprintf(hbuf, sizeof(hbuf), "%d",
330	    ntohs(server_socket_getport(&clt->clt_srv_ss)));
331	if (fcgi_add_param(&param, "SERVER_PORT", hbuf, clt) == -1) {
332		errstr = "failed to encode param";
333		goto fail;
334	}
335
336	if (fcgi_add_param(&param, "SERVER_NAME", srv_conf->name,
337	    clt) == -1) {
338		errstr = "failed to encode param";
339		goto fail;
340	}
341
342	if (fcgi_add_param(&param, "SERVER_PROTOCOL", desc->http_version,
343	    clt) == -1) {
344		errstr = "failed to encode param";
345		goto fail;
346	}
347
348	if (fcgi_add_param(&param, "SERVER_SOFTWARE", HTTPD_SERVERNAME,
349	    clt) == -1) {
350		errstr = "failed to encode param";
351		goto fail;
352	}
353
354	if (param.total_len != 0) {	/* send last params record */
355		if (bufferevent_write(clt->clt_srvbev, &param.buf,
356		    sizeof(struct fcgi_record_header) +
357		    ntohs(h->content_len)) == -1) {
358			errstr = "failed to write to client evbuffer";
359			goto fail;
360		}
361	}
362
363	/* send "no more params" message */
364	h->content_len = 0;
365	if (bufferevent_write(clt->clt_srvbev, &param.buf,
366	    sizeof(struct fcgi_record_header)) == -1) {
367		errstr = "failed to write to client evbuffer";
368		goto fail;
369	}
370
371	bufferevent_settimeout(clt->clt_srvbev,
372	    srv_conf->timeout.tv_sec, srv_conf->timeout.tv_sec);
373	bufferevent_enable(clt->clt_srvbev, EV_READ|EV_WRITE);
374	if (clt->clt_toread != 0) {
375		server_read_httpcontent(clt->clt_bev, clt);
376		bufferevent_enable(clt->clt_bev, EV_READ);
377	} else {
378		bufferevent_disable(clt->clt_bev, EV_READ);
379		fcgi_add_stdin(clt, NULL);
380	}
381
382	if (strcmp(desc->http_version, "HTTP/1.1") == 0) {
383		clt->clt_fcgi.chunked = 1;
384	} else {
385		/* HTTP/1.0 does not support chunked encoding */
386		clt->clt_fcgi.chunked = 0;
387		clt->clt_persist = 0;
388	}
389	clt->clt_fcgi.end = 0;
390	clt->clt_done = 0;
391
392	free(script);
393	return (0);
394 fail:
395	free(script);
396	if (errstr == NULL)
397		errstr = strerror(errno);
398	if (fd != -1 && clt->clt_fd != fd)
399		close(fd);
400	server_abort_http(clt, 500, errstr);
401	return (-1);
402}
403
404int
405fcgi_add_stdin(struct client *clt, struct evbuffer *evbuf)
406{
407	struct fcgi_record_header	h;
408
409	memset(&h, 0, sizeof(h));
410	h.version = 1;
411	h.type = FCGI_STDIN;
412	h.id = htons(1);
413	h.padding_len = 0;
414
415	if (evbuf == NULL) {
416		h.content_len = 0;
417		return bufferevent_write(clt->clt_srvbev, &h,
418		    sizeof(struct fcgi_record_header));
419	} else {
420		h.content_len = htons(EVBUFFER_LENGTH(evbuf));
421		if (bufferevent_write(clt->clt_srvbev, &h,
422		    sizeof(struct fcgi_record_header)) == -1)
423			return -1;
424		return bufferevent_write_buffer(clt->clt_srvbev, evbuf);
425	}
426	return (0);
427}
428
429int
430fcgi_add_param(struct server_fcgi_param *p, const char *key,
431    const char *val, struct client *clt)
432{
433	struct fcgi_record_header	*h;
434	int				 len = 0;
435	int				 key_len = strlen(key);
436	int				 val_len = strlen(val);
437	uint8_t				*param;
438
439	len += key_len + val_len;
440	len += key_len > 127 ? 4 : 1;
441	len += val_len > 127 ? 4 : 1;
442
443	DPRINTF("%s: %s[%d] => %s[%d], total_len: %d", __func__, key, key_len,
444	    val, val_len, p->total_len);
445
446	if (len > FCGI_CONTENT_SIZE)
447		return (-1);
448
449	if (p->total_len + len > FCGI_CONTENT_SIZE) {
450		if (bufferevent_write(clt->clt_srvbev, p->buf,
451		    sizeof(struct fcgi_record_header) + p->total_len) == -1)
452			return (-1);
453		p->total_len = 0;
454	}
455
456	h = (struct fcgi_record_header *)p->buf;
457	param = p->buf + sizeof(*h) + p->total_len;
458
459	if (key_len > 127) {
460		*param++ = ((key_len >> 24) & 0xff) | 0x80;
461		*param++ = ((key_len >> 16) & 0xff);
462		*param++ = ((key_len >> 8) & 0xff);
463		*param++ = (key_len & 0xff);
464	} else
465		*param++ = key_len;
466
467	if (val_len > 127) {
468		*param++ = ((val_len >> 24) & 0xff) | 0x80;
469		*param++ = ((val_len >> 16) & 0xff);
470		*param++ = ((val_len >> 8) & 0xff);
471		*param++ = (val_len & 0xff);
472	} else
473		*param++ = val_len;
474
475	memcpy(param, key, key_len);
476	param += key_len;
477	memcpy(param, val, val_len);
478
479	p->total_len += len;
480
481	h->content_len = htons(p->total_len);
482	return (0);
483}
484
485void
486server_fcgi_error(struct bufferevent *bev, short error, void *arg)
487{
488	struct client		*clt = arg;
489	struct http_descriptor	*desc = clt->clt_descreq;
490
491	if ((error & EVBUFFER_EOF) && !clt->clt_fcgi.headersdone) {
492		server_abort_http(clt, 500, "malformed or no headers");
493		return;
494	}
495
496	/* send the end marker if not already */
497	if (desc->http_method != HTTP_METHOD_HEAD && clt->clt_fcgi.chunked &&
498	    !clt->clt_fcgi.end++)
499		server_bufferevent_print(clt, "0\r\n\r\n");
500
501	server_file_error(bev, error, arg);
502}
503
504void
505server_fcgi_read(struct bufferevent *bev, void *arg)
506{
507	uint8_t				 buf[FCGI_RECORD_SIZE];
508	struct client			*clt = (struct client *) arg;
509	struct fcgi_record_header	*h;
510	size_t				 len;
511	char				*ptr;
512
513	do {
514		len = bufferevent_read(bev, buf, clt->clt_fcgi.toread);
515		if (evbuffer_add(clt->clt_srvevb, buf, len) == -1) {
516			server_abort_http(clt, 500, "short write");
517			return;
518		}
519		clt->clt_fcgi.toread -= len;
520		DPRINTF("%s: len: %lu toread: %d state: %d type: %d",
521		    __func__, len, clt->clt_fcgi.toread,
522		    clt->clt_fcgi.state, clt->clt_fcgi.type);
523
524		if (clt->clt_fcgi.toread != 0)
525			return;
526
527		switch (clt->clt_fcgi.state) {
528		case FCGI_READ_HEADER:
529			clt->clt_fcgi.state = FCGI_READ_CONTENT;
530			h = (struct fcgi_record_header *)
531			    EVBUFFER_DATA(clt->clt_srvevb);
532			DPRINTF("%s: record header: version %d type %d id %d "
533			    "content len %d padding %d", __func__,
534			    h->version, h->type, ntohs(h->id),
535			    ntohs(h->content_len), h->padding_len);
536			clt->clt_fcgi.type = h->type;
537			clt->clt_fcgi.toread = ntohs(h->content_len);
538			clt->clt_fcgi.padding_len = h->padding_len;
539			evbuffer_drain(clt->clt_srvevb,
540			    EVBUFFER_LENGTH(clt->clt_srvevb));
541			if (clt->clt_fcgi.toread != 0)
542				break;
543			else if (clt->clt_fcgi.type == FCGI_STDOUT &&
544			    !clt->clt_chunk) {
545				server_abort_http(clt, 500, "empty stdout");
546				return;
547			}
548
549			/* fallthrough if content_len == 0 */
550		case FCGI_READ_CONTENT:
551			switch (clt->clt_fcgi.type) {
552			case FCGI_STDERR:
553				if (EVBUFFER_LENGTH(clt->clt_srvevb) > 0 &&
554				    (ptr = get_string(
555				    EVBUFFER_DATA(clt->clt_srvevb),
556				    EVBUFFER_LENGTH(clt->clt_srvevb)))
557				    != NULL) {
558					server_sendlog(clt->clt_srv_conf,
559					    IMSG_LOG_ERROR, "%s", ptr);
560					free(ptr);
561				}
562				break;
563			case FCGI_STDOUT:
564				++clt->clt_chunk;
565				if (!clt->clt_fcgi.headersdone) {
566					clt->clt_fcgi.headersdone =
567					    server_fcgi_getheaders(clt);
568					if (!EVBUFFER_LENGTH(clt->clt_srvevb))
569						break;
570				}
571				/* FALLTHROUGH */
572			case FCGI_END_REQUEST:
573				if (clt->clt_fcgi.headersdone &&
574				    !clt->clt_fcgi.headerssent) {
575					if (server_fcgi_header(clt,
576					    clt->clt_fcgi.status) == -1) {
577						server_abort_http(clt, 500,
578						    "malformed fcgi headers");
579						return;
580					}
581				}
582				/* Don't send content for HEAD requests */
583				if (clt->clt_fcgi.headerssent &&
584				    ((struct http_descriptor *)
585				    clt->clt_descreq)->http_method
586				    == HTTP_METHOD_HEAD)
587					return;
588				if (server_fcgi_writechunk(clt) == -1) {
589					server_abort_http(clt, 500,
590					    "encoding error");
591					return;
592				}
593				break;
594			}
595			evbuffer_drain(clt->clt_srvevb,
596			    EVBUFFER_LENGTH(clt->clt_srvevb));
597			if (!clt->clt_fcgi.padding_len) {
598				clt->clt_fcgi.state = FCGI_READ_HEADER;
599				clt->clt_fcgi.toread =
600				    sizeof(struct fcgi_record_header);
601			} else {
602				clt->clt_fcgi.state = FCGI_READ_PADDING;
603				clt->clt_fcgi.toread =
604				    clt->clt_fcgi.padding_len;
605			}
606			break;
607		case FCGI_READ_PADDING:
608			evbuffer_drain(clt->clt_srvevb,
609			    EVBUFFER_LENGTH(clt->clt_srvevb));
610			clt->clt_fcgi.state = FCGI_READ_HEADER;
611			clt->clt_fcgi.toread =
612			    sizeof(struct fcgi_record_header);
613			break;
614		}
615	} while (len > 0);
616}
617
618int
619server_fcgi_header(struct client *clt, unsigned int code)
620{
621	struct server_config	*srv_conf = clt->clt_srv_conf;
622	struct http_descriptor	*desc = clt->clt_descreq;
623	struct http_descriptor	*resp = clt->clt_descresp;
624	const char		*error;
625	char			 tmbuf[32];
626	struct kv		*kv, *cl, key;
627
628	clt->clt_fcgi.headerssent = 1;
629
630	if (desc == NULL || (error = server_httperror_byid(code)) == NULL)
631		return (-1);
632
633	if (server_log_http(clt, code, 0) == -1)
634		return (-1);
635
636	/* Add error codes */
637	if (kv_setkey(&resp->http_pathquery, "%u", code) == -1 ||
638	    kv_set(&resp->http_pathquery, "%s", error) == -1)
639		return (-1);
640
641	/* Add headers */
642	if (kv_add(&resp->http_headers, "Server", HTTPD_SERVERNAME) == NULL)
643		return (-1);
644
645	if (clt->clt_fcgi.type == FCGI_END_REQUEST ||
646	    EVBUFFER_LENGTH(clt->clt_srvevb) == 0) {
647		/* Can't chunk encode an empty body. */
648		clt->clt_fcgi.chunked = 0;
649
650		/* But then we need a Content-Length unless method is HEAD... */
651		if (desc->http_method != HTTP_METHOD_HEAD) {
652			key.kv_key = "Content-Length";
653			if ((kv = kv_find(&resp->http_headers, &key)) == NULL) {
654				if (kv_add(&resp->http_headers,
655				    "Content-Length", "0") == NULL)
656					return (-1);
657			}
658		}
659	}
660
661	/* Send chunked encoding header */
662	if (clt->clt_fcgi.chunked) {
663		/* but only if no Content-Length header is supplied */
664		key.kv_key = "Content-Length";
665		if ((kv = kv_find(&resp->http_headers, &key)) != NULL) {
666			clt->clt_fcgi.chunked = 0;
667		} else {
668			/*
669			 * XXX What if the FastCGI added some kind of
670			 * Transfer-Encoding, like gzip, deflate or even
671			 * "chunked"?
672			 */
673			if (kv_add(&resp->http_headers,
674			    "Transfer-Encoding", "chunked") == NULL)
675				return (-1);
676		}
677	}
678
679	/* Is it a persistent connection? */
680	if (clt->clt_persist) {
681		if (kv_add(&resp->http_headers,
682		    "Connection", "keep-alive") == NULL)
683			return (-1);
684	} else if (kv_add(&resp->http_headers, "Connection", "close") == NULL)
685		return (-1);
686
687	/* HSTS header */
688	if (srv_conf->flags & SRVFLAG_SERVER_HSTS &&
689	    srv_conf->flags & SRVFLAG_TLS) {
690		if ((cl =
691		    kv_add(&resp->http_headers, "Strict-Transport-Security",
692		    NULL)) == NULL ||
693		    kv_set(cl, "max-age=%d%s%s", srv_conf->hsts_max_age,
694		    srv_conf->hsts_flags & HSTSFLAG_SUBDOMAINS ?
695		    "; includeSubDomains" : "",
696		    srv_conf->hsts_flags & HSTSFLAG_PRELOAD ?
697		    "; preload" : "") == -1)
698			return (-1);
699	}
700
701	/* Date header is mandatory and should be added as late as possible */
702	key.kv_key = "Date";
703	if (kv_find(&resp->http_headers, &key) == NULL &&
704	    (server_http_time(time(NULL), tmbuf, sizeof(tmbuf)) <= 0 ||
705	    kv_add(&resp->http_headers, "Date", tmbuf) == NULL))
706		return (-1);
707
708	if (server_writeresponse_http(clt) == -1 ||
709	    server_bufferevent_print(clt, "\r\n") == -1 ||
710	    server_headers(clt, resp, server_writeheader_http, NULL) == -1 ||
711	    server_bufferevent_print(clt, "\r\n") == -1)
712		return (-1);
713
714	return (0);
715}
716
717int
718server_fcgi_writeheader(struct client *clt, struct kv *hdr, void *arg)
719{
720	struct server_fcgi_param	*param = arg;
721	char				*val, *name, *p;
722	const char			*key;
723	int				 ret;
724
725	/* The key might have been updated in the parent */
726	if (hdr->kv_parent != NULL && hdr->kv_parent->kv_key != NULL)
727		key = hdr->kv_parent->kv_key;
728	else
729		key = hdr->kv_key;
730
731	val = hdr->kv_value;
732
733	if (strcasecmp(key, "Content-Length") == 0 ||
734	    strcasecmp(key, "Content-Type") == 0) {
735		if ((name = strdup(key)) == NULL)
736			return (-1);
737	} else {
738		if (asprintf(&name, "HTTP_%s", key) == -1)
739			return (-1);
740	}
741
742	/*
743	 * RFC 7230 defines a header field-name as a "token" and a "token"
744	 * is defined as one or more characters for which isalpha or
745	 * isdigit is true plus a list of additional characters.
746	 * According to RFC 3875 a CGI environment variable is created
747	 * by converting all letters to upper case and replacing '-'
748	 * with '_'.
749	 */
750	for (p = name; *p != '\0'; p++) {
751		if (isalpha((unsigned char)*p))
752			*p = toupper((unsigned char)*p);
753		else if (!(*p == '!' || *p == '#' || *p == '$' || *p == '%' ||
754		    *p == '&' || *p == '\'' || *p == '*' || *p == '+' ||
755		    *p == '.' || *p == '^' || *p == '_' || *p == '`' ||
756		    *p == '|' || *p == '~' || isdigit((unsigned char)*p)))
757			*p = '_';
758	}
759
760	ret = fcgi_add_param(param, name, val, clt);
761	free(name);
762
763	return (ret);
764}
765
766int
767server_fcgi_writechunk(struct client *clt)
768{
769	struct evbuffer *evb = clt->clt_srvevb;
770	size_t		 len;
771
772	if (clt->clt_fcgi.type == FCGI_END_REQUEST) {
773		len = 0;
774	} else
775		len = EVBUFFER_LENGTH(evb);
776
777	if (clt->clt_fcgi.chunked) {
778		/* If len is 0, make sure to write the end marker only once */
779		if (len == 0 && clt->clt_fcgi.end++)
780			return (0);
781		if (server_bufferevent_printf(clt, "%zx\r\n", len) == -1 ||
782		    server_bufferevent_write_chunk(clt, evb, len) == -1 ||
783		    server_bufferevent_print(clt, "\r\n") == -1)
784			return (-1);
785	} else if (len)
786		return (server_bufferevent_write_buffer(clt, evb));
787
788	return (0);
789}
790
791int
792server_fcgi_getheaders(struct client *clt)
793{
794	struct http_descriptor	*resp = clt->clt_descresp;
795	struct evbuffer		*evb = clt->clt_srvevb;
796	int			 code, ret;
797	char			*line, *key, *value;
798	const char		*errstr;
799
800	while ((line = evbuffer_getline(evb)) != NULL && *line != '\0') {
801		key = line;
802
803		if ((value = strchr(key, ':')) == NULL)
804			break;
805
806		*value++ = '\0';
807		value += strspn(value, " \t");
808
809		DPRINTF("%s: %s: %s", __func__, key, value);
810
811		if (strcasecmp("Status", key) == 0) {
812			value[strcspn(value, " \t")] = '\0';
813			code = (int)strtonum(value, 100, 600, &errstr);
814			if (errstr != NULL || server_httperror_byid(
815			    code) == NULL)
816				code = 200;
817			clt->clt_fcgi.status = code;
818		} else {
819			(void)kv_add(&resp->http_headers, key, value);
820		}
821		free(line);
822	}
823
824	ret = (line != NULL && *line == '\0');
825
826	free(line);
827	return ret;
828}
829