server_fcgi.c revision 1.26
1/*	$OpenBSD: server_fcgi.c,v 1.26 2014/08/06 20:56:23 florian 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/queue.h>
21#include <sys/time.h>
22#include <sys/stat.h>
23#include <sys/socket.h>
24#include <sys/un.h>
25#include <sys/tree.h>
26#include <sys/hash.h>
27
28#include <net/if.h>
29#include <netinet/in_systm.h>
30#include <netinet/in.h>
31#include <netinet/ip.h>
32#include <netinet/tcp.h>
33#include <arpa/inet.h>
34
35#include <errno.h>
36#include <fcntl.h>
37#include <stdlib.h>
38#include <string.h>
39#include <unistd.h>
40#include <stdio.h>
41#include <ctype.h>
42#include <err.h>
43#include <event.h>
44
45#include "httpd.h"
46#include "http.h"
47
48#define FCGI_PADDING_SIZE	 255
49#define FCGI_RECORD_SIZE	 \
50    (sizeof(struct fcgi_record_header) + FCGI_CONTENT_SIZE + FCGI_PADDING_SIZE)
51
52#define FCGI_BEGIN_REQUEST	 1
53#define FCGI_ABORT_REQUEST	 2
54#define FCGI_END_REQUEST	 3
55#define FCGI_PARAMS		 4
56#define FCGI_STDIN		 5
57#define FCGI_STDOUT		 6
58#define FCGI_STDERR		 7
59#define FCGI_DATA		 8
60#define FCGI_GET_VALUES		 9
61#define FCGI_GET_VALUES_RESULT	10
62#define FCGI_UNKNOWN_TYPE	11
63#define FCGI_MAXTYPE		(FCGI_UNKNOWN_TYPE)
64
65#define FCGI_RESPONDER		 1
66
67struct fcgi_record_header {
68	uint8_t		version;
69	uint8_t		type;
70	uint16_t	id;
71	uint16_t	content_len;
72	uint8_t		padding_len;
73	uint8_t		reserved;
74} __packed;
75
76struct fcgi_begin_request_body {
77	uint16_t	role;
78	uint8_t		flags;
79	uint8_t		reserved[5];
80} __packed;
81
82struct server_fcgi_param {
83	int		total_len;
84	uint8_t		buf[FCGI_RECORD_SIZE];
85};
86
87int	server_fcgi_header(struct client *, u_int);
88void	server_fcgi_read(struct bufferevent *, void *);
89int	server_fcgi_writeheader(struct client *, struct kv *, void *);
90int	fcgi_add_param(struct server_fcgi_param *, const char *, const char *,
91	    struct client *);
92
93int
94server_fcgi(struct httpd *env, struct client *clt)
95{
96	struct server_fcgi_param	 param;
97	char				 hbuf[MAXHOSTNAMELEN];
98	struct server_config		*srv_conf = clt->clt_srv_conf;
99	struct http_descriptor		*desc	= clt->clt_desc;
100	struct sockaddr_un		 sun;
101	struct fcgi_record_header	*h;
102	struct fcgi_begin_request_body	*begin;
103	size_t				 len;
104	ssize_t				 scriptlen;
105	int				 fd = -1, ret;
106	const char			*errstr = NULL;
107	char				*str, *p, *script = NULL;
108	in_port_t			 port;
109	struct sockaddr_storage		 ss;
110
111	if (srv_conf->socket[0] == ':') {
112		p = srv_conf->socket + 1;
113
114		port = strtonum(p, 0, 0xffff, &errstr);
115		if (errstr != NULL) {
116			log_warn("%s: strtonum %s, %s", __func__, p, errstr);
117			goto fail;
118		}
119		memset(&ss, 0, sizeof(ss));
120		ss.ss_family = AF_INET;
121		((struct sockaddr_in *)
122		    &ss)->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
123		port = htons(port);
124
125		if ((fd = server_socket_connect(&ss, port, srv_conf)) == -1)
126			goto fail;
127	} else {
128		if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
129			goto fail;
130
131		memset(&sun, 0, sizeof(sun));
132		sun.sun_family = AF_UNIX;
133		len = strlcpy(sun.sun_path,
134		    srv_conf->socket, sizeof(sun.sun_path));
135		if (len >= sizeof(sun.sun_path)) {
136			errstr = "socket path to long";
137			goto fail;
138		}
139		sun.sun_len = len;
140
141		if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1)
142			goto fail;
143	}
144
145	socket_set_blockmode(fd, BM_NONBLOCK);
146
147	memset(hbuf, 0, sizeof(hbuf));
148	clt->clt_fcgi_state = FCGI_READ_HEADER;
149	clt->clt_fcgi_toread = sizeof(struct fcgi_record_header);
150
151	if (clt->clt_srvevb != NULL)
152		evbuffer_free(clt->clt_srvevb);
153
154	clt->clt_srvevb = evbuffer_new();
155	if (clt->clt_srvevb == NULL) {
156		errstr = "failed to allocate evbuffer";
157		goto fail;
158	}
159
160	clt->clt_fd = fd;
161	if (clt->clt_srvbev != NULL)
162		bufferevent_free(clt->clt_srvbev);
163
164	clt->clt_srvbev = bufferevent_new(fd, server_fcgi_read,
165	    NULL, server_file_error, clt);
166	if (clt->clt_srvbev == NULL) {
167		errstr = "failed to allocate fcgi buffer event";
168		goto fail;
169	}
170
171	memset(&param, 0, sizeof(param));
172
173	h = (struct fcgi_record_header *)&param.buf;
174	h->version = 1;
175	h->type = FCGI_BEGIN_REQUEST;
176	h->id = htons(1);
177	h->content_len = htons(sizeof(struct fcgi_begin_request_body));
178	h->padding_len = 0;
179
180	begin = (struct fcgi_begin_request_body *)&param.buf[sizeof(struct
181	    fcgi_record_header)];
182	begin->role = htons(FCGI_RESPONDER);
183
184	bufferevent_write(clt->clt_srvbev, &param.buf,
185	    sizeof(struct fcgi_record_header) +
186	    sizeof(struct fcgi_begin_request_body));
187
188	h->type = FCGI_PARAMS;
189	h->content_len = param.total_len = 0;
190
191	if (asprintf(&script, "%s%s", srv_conf->root,
192	    desc->http_path) == -1 ||
193	    (scriptlen = path_info(script)) == -1) {
194		errstr = "failed to get script name";
195		goto fail;
196	}
197
198	if (scriptlen) {
199		if (fcgi_add_param(&param, "PATH_INFO",
200		    script + scriptlen, clt) == -1) {
201			errstr = "failed to encode param";
202			goto fail;
203		}
204		script[scriptlen] = '\0';
205	}
206
207	if (fcgi_add_param(&param, "SCRIPT_NAME",
208	    script + strlen(srv_conf->root), clt) == -1) {
209		errstr = "failed to encode param";
210		goto fail;
211	}
212	if (fcgi_add_param(&param, "SCRIPT_FILENAME", script, clt) == -1) {
213		errstr = "failed to encode param";
214		goto fail;
215	}
216
217	if (desc->http_query)
218		if (fcgi_add_param(&param, "QUERY_STRING", desc->http_query,
219		    clt) == -1) {
220			errstr = "failed to encode param";
221			goto fail;
222		}
223
224	if (fcgi_add_param(&param, "DOCUMENT_ROOT", srv_conf->root,
225	    clt) == -1) {
226		errstr = "failed to encode param";
227		goto fail;
228	}
229	if (fcgi_add_param(&param, "DOCUMENT_URI", desc->http_path,
230	    clt) == -1) {
231		errstr = "failed to encode param";
232		goto fail;
233	}
234	if (fcgi_add_param(&param, "GATEWAY_INTERFACE", "CGI/1.1",
235	    clt) == -1) {
236		errstr = "failed to encode param";
237		goto fail;
238	}
239
240	/* Add HTTP_* headers */
241	if (server_headers(clt, server_fcgi_writeheader, &param) == -1) {
242		errstr = "failed to encode param";
243		goto fail;
244	}
245
246	if (srv_conf->flags & SRVFLAG_SSL)
247		if (fcgi_add_param(&param, "HTTPS", "on", clt) == -1) {
248			errstr = "failed to encode param";
249			goto fail;
250		}
251
252	(void)print_host(&clt->clt_ss, hbuf, sizeof(hbuf));
253	if (fcgi_add_param(&param, "REMOTE_ADDR", hbuf, clt) == -1) {
254		errstr = "failed to encode param";
255		goto fail;
256	}
257
258	(void)snprintf(hbuf, sizeof(hbuf), "%d", ntohs(clt->clt_port));
259	if (fcgi_add_param(&param, "REMOTE_PORT", hbuf, clt) == -1) {
260		errstr = "failed to encode param";
261		goto fail;
262	}
263
264	if (fcgi_add_param(&param, "REQUEST_METHOD",
265	    server_httpmethod_byid(desc->http_method), clt) == -1) {
266		errstr = "failed to encode param";
267		goto fail;
268	}
269
270	if (!desc->http_query) {
271		if (fcgi_add_param(&param, "REQUEST_URI", desc->http_path,
272		    clt) == -1) {
273			errstr = "failed to encode param";
274			goto fail;
275		}
276	} else if (asprintf(&str, "%s?%s", desc->http_path,
277	    desc->http_query) != -1) {
278		ret = fcgi_add_param(&param, "REQUEST_URI", str, clt);
279		free(str);
280		if (ret == -1) {
281			errstr = "failed to encode param";
282			goto fail;
283		}
284	}
285
286	(void)print_host(&clt->clt_srv_ss, hbuf, sizeof(hbuf));
287	if (fcgi_add_param(&param, "SERVER_ADDR", hbuf, clt) == -1) {
288		errstr = "failed to encode param";
289		goto fail;
290	}
291
292	(void)snprintf(hbuf, sizeof(hbuf), "%d",
293	    ntohs(server_socket_getport(&clt->clt_srv_ss)));
294	if (fcgi_add_param(&param, "SERVER_PORT", hbuf, clt) == -1) {
295		errstr = "failed to encode param";
296		goto fail;
297	}
298
299	if (fcgi_add_param(&param, "SERVER_NAME", srv_conf->name,
300	    clt) == -1) {
301		errstr = "failed to encode param";
302		goto fail;
303	}
304
305	if (fcgi_add_param(&param, "SERVER_PROTOCOL", desc->http_version,
306	    clt) == -1) {
307		errstr = "failed to encode param";
308		goto fail;
309	}
310
311	if (fcgi_add_param(&param, "SERVER_SOFTWARE", HTTPD_SERVERNAME,
312	    clt) == -1) {
313		errstr = "failed to encode param";
314		goto fail;
315	}
316
317	if (param.total_len != 0) {	/* send last params record */
318		bufferevent_write(clt->clt_srvbev, &param.buf,
319		    sizeof(struct fcgi_record_header) +
320		    ntohs(h->content_len));
321	}
322
323	/* send "no more params" message */
324	h->content_len = 0;
325	bufferevent_write(clt->clt_srvbev, &param.buf,
326	    sizeof(struct fcgi_record_header));
327
328	bufferevent_settimeout(clt->clt_srvbev,
329	    srv_conf->timeout.tv_sec, srv_conf->timeout.tv_sec);
330	bufferevent_enable(clt->clt_srvbev, EV_READ|EV_WRITE);
331	if (clt->clt_toread != 0) {
332		server_read_httpcontent(clt->clt_bev, clt);
333		bufferevent_enable(clt->clt_bev, EV_READ);
334	} else {
335		bufferevent_disable(clt->clt_bev, EV_READ);
336		fcgi_add_stdin(clt, NULL);
337	}
338
339	/*
340	 * persist is not supported yet because we don't get the
341	 * Content-Length from slowcgi and don't support chunked encoding.
342	 */
343	clt->clt_persist = 0;
344	clt->clt_done = 0;
345
346	free(script);
347	return (0);
348 fail:
349	free(script);
350	if (errstr == NULL)
351		errstr = strerror(errno);
352	server_abort_http(clt, 500, errstr);
353	return (-1);
354}
355
356int
357fcgi_add_stdin(struct client *clt, struct evbuffer *evbuf)
358{
359	struct fcgi_record_header	h;
360
361	memset(&h, 0, sizeof(h));
362	h.version = 1;
363	h.type = FCGI_STDIN;
364	h.id = htons(1);
365	h.padding_len = 0;
366
367	if (evbuf == NULL) {
368		h.content_len = 0;
369		return bufferevent_write(clt->clt_srvbev, &h,
370		    sizeof(struct fcgi_record_header));
371	} else {
372		h.content_len = htons(EVBUFFER_LENGTH(evbuf));
373		if (bufferevent_write(clt->clt_srvbev, &h,
374		    sizeof(struct fcgi_record_header)) == -1)
375			return -1;
376		return bufferevent_write_buffer(clt->clt_srvbev, evbuf);
377	}
378	return (0);
379}
380
381int
382fcgi_add_param(struct server_fcgi_param *p, const char *key,
383    const char *val, struct client *clt)
384{
385	struct fcgi_record_header	*h;
386	int				 len = 0;
387	int				 key_len = strlen(key);
388	int				 val_len = strlen(val);
389	uint8_t				*param;
390
391	len += key_len + val_len;
392	len += key_len > 127 ? 4 : 1;
393	len += val_len > 127 ? 4 : 1;
394
395	DPRINTF("%s: %s[%d] => %s[%d], total_len: %d", __func__, key, key_len,
396	    val, val_len, p->total_len);
397
398	if (len > FCGI_CONTENT_SIZE)
399		return (-1);
400
401	if (p->total_len + len > FCGI_CONTENT_SIZE) {
402		bufferevent_write(clt->clt_srvbev, p->buf,
403		    sizeof(struct fcgi_record_header) + p->total_len);
404		p->total_len = 0;
405	}
406
407	h = (struct fcgi_record_header *)p->buf;
408	param = p->buf + sizeof(*h) + p->total_len;
409
410	if (key_len > 127) {
411		*param++ = ((key_len >> 24) & 0xff) | 0x80;
412		*param++ = ((key_len >> 16) & 0xff);
413		*param++ = ((key_len >> 8) & 0xff);
414		*param++ = (key_len & 0xff);
415	} else
416		*param++ = key_len;
417
418	if (val_len > 127) {
419		*param++ = ((val_len >> 24) & 0xff) | 0x80;
420		*param++ = ((val_len >> 16) & 0xff);
421		*param++ = ((val_len >> 8) & 0xff);
422		*param++ = (val_len & 0xff);
423	} else
424		*param++ = val_len;
425
426	memcpy(param, key, key_len);
427	param += key_len;
428	memcpy(param, val, val_len);
429
430	p->total_len += len;
431
432	h->content_len = htons(p->total_len);
433	return (0);
434}
435
436void
437server_fcgi_read(struct bufferevent *bev, void *arg)
438{
439	uint8_t				 buf[FCGI_RECORD_SIZE];
440	struct client			*clt = (struct client *) arg;
441	struct fcgi_record_header	*h;
442	size_t				 len;
443
444	do {
445		len = bufferevent_read(bev, &buf, clt->clt_fcgi_toread);
446		/* XXX error handling */
447		evbuffer_add(clt->clt_srvevb, &buf, len);
448		clt->clt_fcgi_toread -= len;
449		DPRINTF("%s: len: %lu toread: %d state: %d", __func__, len,
450		    clt->clt_fcgi_toread, clt->clt_fcgi_state);
451
452		if (clt->clt_fcgi_toread != 0)
453			return;
454
455		switch (clt->clt_fcgi_state) {
456		case FCGI_READ_HEADER:
457			clt->clt_fcgi_state = FCGI_READ_CONTENT;
458			h = (struct fcgi_record_header *)
459			    EVBUFFER_DATA(clt->clt_srvevb);
460			DPRINTF("%s: record header: version %d type %d id %d "
461			    "content len %d padding %d", __func__,
462			     h->version, h->type, ntohs(h->id),
463			     ntohs(h->content_len), h->padding_len);
464			clt->clt_fcgi_type = h->type;
465			clt->clt_fcgi_toread = ntohs(h->content_len);
466			clt->clt_fcgi_padding_len = h->padding_len;
467			evbuffer_drain(clt->clt_srvevb,
468			    EVBUFFER_LENGTH(clt->clt_srvevb));
469			if (clt->clt_fcgi_toread != 0)
470				break;
471			else if (clt->clt_fcgi_type == FCGI_STDOUT &&
472			    !clt->clt_chunk) {
473				server_abort_http(clt, 500, "empty stdout");
474				return;
475			}
476
477			/* fallthrough if content_len == 0 */
478		case FCGI_READ_CONTENT:
479			if (clt->clt_fcgi_type == FCGI_STDOUT &&
480			    EVBUFFER_LENGTH(clt->clt_srvevb) > 0) {
481				if (++clt->clt_chunk == 1)
482					server_fcgi_header(clt, 200);
483				server_bufferevent_write_buffer(clt,
484				    clt->clt_srvevb);
485			}
486			evbuffer_drain(clt->clt_srvevb,
487			    EVBUFFER_LENGTH(clt->clt_srvevb));
488			if (!clt->clt_fcgi_padding_len) {
489				clt->clt_fcgi_state = FCGI_READ_HEADER;
490				clt->clt_fcgi_toread =
491				    sizeof(struct fcgi_record_header);
492			} else {
493				clt->clt_fcgi_state = FCGI_READ_PADDING;
494				clt->clt_fcgi_toread =
495				    clt->clt_fcgi_padding_len;
496			}
497			break;
498		case FCGI_READ_PADDING:
499			evbuffer_drain(clt->clt_srvevb,
500			    EVBUFFER_LENGTH(clt->clt_srvevb));
501			clt->clt_fcgi_state = FCGI_READ_HEADER;
502			clt->clt_fcgi_toread =
503			    sizeof(struct fcgi_record_header);
504			break;
505		}
506	} while (len > 0);
507}
508
509int
510server_fcgi_header(struct client *clt, u_int code)
511{
512	struct http_descriptor	*desc = clt->clt_desc;
513	const char		*error;
514	char			 tmbuf[32];
515
516	if (desc == NULL || (error = server_httperror_byid(code)) == NULL)
517		return (-1);
518
519	if (server_log_http(clt, code, 0) == -1)
520		return (-1);
521
522	kv_purge(&desc->http_headers);
523
524	/* Add error codes */
525	if (kv_setkey(&desc->http_pathquery, "%lu", code) == -1 ||
526	    kv_set(&desc->http_pathquery, "%s", error) == -1)
527		return (-1);
528
529	/* Add headers */
530	if (kv_add(&desc->http_headers, "Server", HTTPD_SERVERNAME) == NULL)
531		return (-1);
532
533	/* Is it a persistent connection? */
534	if (clt->clt_persist) {
535		if (kv_add(&desc->http_headers,
536		    "Connection", "keep-alive") == NULL)
537			return (-1);
538	} else if (kv_add(&desc->http_headers, "Connection", "close") == NULL)
539		return (-1);
540
541	/* Date header is mandatory and should be added last */
542	server_http_date(tmbuf, sizeof(tmbuf));
543	if (kv_add(&desc->http_headers, "Date", tmbuf) == NULL)
544		return (-1);
545
546	/* Write initial header (fcgi might append more) */
547	if (server_writeresponse_http(clt) == -1 ||
548	    server_bufferevent_print(clt, "\r\n") == -1 ||
549	    server_headers(clt, server_writeheader_http, NULL) == -1)
550		return (-1);
551
552	return (0);
553}
554
555int
556server_fcgi_writeheader(struct client *clt, struct kv *hdr, void *arg)
557{
558	struct server_fcgi_param	*param = arg;
559	char				*val, *name, *p;
560	const char			*key;
561	int				 ret;
562
563	if (hdr->kv_flags & KV_FLAG_INVALID)
564		return (0);
565
566	/* The key might have been updated in the parent */
567	if (hdr->kv_parent != NULL && hdr->kv_parent->kv_key != NULL)
568		key = hdr->kv_parent->kv_key;
569	else
570		key = hdr->kv_key;
571
572	val = hdr->kv_value;
573
574	if (strcasecmp(key, "Content-Length") == 0 ||
575	    strcasecmp(key, "Content-Type") == 0) {
576		if ((name = strdup(key)) == NULL)
577			return (-1);
578	} else {
579		if (asprintf(&name, "HTTP_%s", key) == -1)
580			return (-1);
581	}
582
583	for (p = name; *p != '\0'; p++) {
584		if (isalpha((unsigned char)*p))
585			*p = toupper((unsigned char)*p);
586		else
587			*p = '_';
588	}
589
590	ret = fcgi_add_param(param, name, val, clt);
591	free(name);
592
593	return (ret);
594}
595