xref: /lighttpd1.4/src/mod_proxy.c (revision dbdab5db)
1 #include "first.h"
2 
3 #include "buffer.h"
4 #include "server.h"
5 #include "keyvalue.h"
6 #include "log.h"
7 
8 #include "http_chunk.h"
9 #include "fdevent.h"
10 #include "connections.h"
11 #include "response.h"
12 #include "joblist.h"
13 
14 #include "plugin.h"
15 
16 #include "inet_ntop_cache.h"
17 #include "crc32.h"
18 
19 #include <sys/types.h>
20 
21 #include <unistd.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include <ctype.h>
27 #include <assert.h>
28 
29 #include <stdio.h>
30 
31 #include "sys-socket.h"
32 
33 #define data_proxy data_fastcgi
34 #define data_proxy_init data_fastcgi_init
35 
36 #define PROXY_RETRY_TIMEOUT 60
37 
38 /**
39  *
40  * the proxy module is based on the fastcgi module
41  *
42  * 28.06.2004 Jan Kneschke     The first release
43  * 01.07.2004 Evgeny Rodichev  Several bugfixes and cleanups
44  *            - co-ordinate up- and downstream flows correctly (proxy_demux_response
45  *              and proxy_handle_fdevent)
46  *            - correctly transfer upstream http_response_status;
47  *            - some unused structures removed.
48  *
49  * TODO:      - delay upstream read if write_queue is too large
50  *              (to prevent memory eating, like in apache). Shoud be
51  *              configurable).
52  *            - persistent connection with upstream servers
53  *            - HTTP/1.1
54  */
55 typedef enum {
56 	PROXY_BALANCE_UNSET,
57 	PROXY_BALANCE_FAIR,
58 	PROXY_BALANCE_HASH,
59 	PROXY_BALANCE_RR
60 } proxy_balance_t;
61 
62 typedef struct {
63 	array *extensions;
64 	unsigned short debug;
65 
66 	proxy_balance_t balance;
67 } plugin_config;
68 
69 typedef struct {
70 	PLUGIN_DATA;
71 
72 	buffer *parse_response;
73 	buffer *balance_buf;
74 
75 	plugin_config **config_storage;
76 
77 	plugin_config conf;
78 } plugin_data;
79 
80 typedef enum {
81 	PROXY_STATE_INIT,
82 	PROXY_STATE_CONNECT,
83 	PROXY_STATE_PREPARE_WRITE,
84 	PROXY_STATE_WRITE,
85 	PROXY_STATE_READ
86 } proxy_connection_state_t;
87 
88 enum { PROXY_STDOUT, PROXY_END_REQUEST };
89 
90 typedef struct {
91 	proxy_connection_state_t state;
92 	time_t state_timestamp;
93 
94 	data_proxy *host;
95 
96 	buffer *response;
97 	buffer *response_header;
98 
99 	chunkqueue *wb;
100 
101 	int fd; /* fd to the proxy process */
102 	int fde_ndx; /* index into the fd-event buffer */
103 
104 	size_t path_info_offset; /* start of path_info in uri.path */
105 
106 	connection *remote_conn;  /* dump pointer */
107 	plugin_data *plugin_data; /* dump pointer */
108 } handler_ctx;
109 
110 
111 /* ok, we need a prototype */
112 static handler_t proxy_handle_fdevent(server *srv, void *ctx, int revents);
113 
114 static handler_ctx * handler_ctx_init(void) {
115 	handler_ctx * hctx;
116 
117 
118 	hctx = calloc(1, sizeof(*hctx));
119 
120 	hctx->state = PROXY_STATE_INIT;
121 	hctx->host = NULL;
122 
123 	hctx->response = buffer_init();
124 	hctx->response_header = buffer_init();
125 
126 	hctx->wb = chunkqueue_init();
127 
128 	hctx->fd = -1;
129 	hctx->fde_ndx = -1;
130 
131 	return hctx;
132 }
133 
134 static void handler_ctx_free(handler_ctx *hctx) {
135 	buffer_free(hctx->response);
136 	buffer_free(hctx->response_header);
137 	chunkqueue_free(hctx->wb);
138 
139 	free(hctx);
140 }
141 
142 INIT_FUNC(mod_proxy_init) {
143 	plugin_data *p;
144 
145 	p = calloc(1, sizeof(*p));
146 
147 	p->parse_response = buffer_init();
148 	p->balance_buf = buffer_init();
149 
150 	return p;
151 }
152 
153 
154 FREE_FUNC(mod_proxy_free) {
155 	plugin_data *p = p_d;
156 
157 	UNUSED(srv);
158 
159 	buffer_free(p->parse_response);
160 	buffer_free(p->balance_buf);
161 
162 	if (p->config_storage) {
163 		size_t i;
164 		for (i = 0; i < srv->config_context->used; i++) {
165 			plugin_config *s = p->config_storage[i];
166 
167 			if (NULL == s) continue;
168 
169 			array_free(s->extensions);
170 
171 			free(s);
172 		}
173 		free(p->config_storage);
174 	}
175 
176 	free(p);
177 
178 	return HANDLER_GO_ON;
179 }
180 
181 SETDEFAULTS_FUNC(mod_proxy_set_defaults) {
182 	plugin_data *p = p_d;
183 	data_unset *du;
184 	size_t i = 0;
185 
186 	config_values_t cv[] = {
187 		{ "proxy.server",              NULL, T_CONFIG_LOCAL, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
188 		{ "proxy.debug",               NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
189 		{ "proxy.balance",             NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },      /* 2 */
190 		{ NULL,                        NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
191 	};
192 
193 	p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));
194 
195 	for (i = 0; i < srv->config_context->used; i++) {
196 		data_config const* config = (data_config const*)srv->config_context->data[i];
197 		plugin_config *s;
198 
199 		s = malloc(sizeof(plugin_config));
200 		s->extensions    = array_init();
201 		s->debug         = 0;
202 
203 		cv[0].destination = s->extensions;
204 		cv[1].destination = &(s->debug);
205 		cv[2].destination = p->balance_buf;
206 
207 		buffer_reset(p->balance_buf);
208 
209 		p->config_storage[i] = s;
210 
211 		if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
212 			return HANDLER_ERROR;
213 		}
214 
215 		if (buffer_string_is_empty(p->balance_buf)) {
216 			s->balance = PROXY_BALANCE_FAIR;
217 		} else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("fair"))) {
218 			s->balance = PROXY_BALANCE_FAIR;
219 		} else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("round-robin"))) {
220 			s->balance = PROXY_BALANCE_RR;
221 		} else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("hash"))) {
222 			s->balance = PROXY_BALANCE_HASH;
223 		} else {
224 			log_error_write(srv, __FILE__, __LINE__, "sb",
225 				        "proxy.balance has to be one of: fair, round-robin, hash, but not:", p->balance_buf);
226 			return HANDLER_ERROR;
227 		}
228 
229 		if (NULL != (du = array_get_element(config->value, "proxy.server"))) {
230 			size_t j;
231 			data_array *da = (data_array *)du;
232 
233 			if (du->type != TYPE_ARRAY) {
234 				log_error_write(srv, __FILE__, __LINE__, "sss",
235 						"unexpected type for key: ", "proxy.server", "expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
236 
237 				return HANDLER_ERROR;
238 			}
239 
240 			/*
241 			 * proxy.server = ( "<ext>" => ...,
242 			 *                  "<ext>" => ... )
243 			 */
244 
245 			for (j = 0; j < da->value->used; j++) {
246 				data_array *da_ext = (data_array *)da->value->data[j];
247 				size_t n;
248 
249 				if (da_ext->type != TYPE_ARRAY) {
250 					log_error_write(srv, __FILE__, __LINE__, "sssbs",
251 							"unexpected type for key: ", "proxy.server",
252 							"[", da->value->data[j]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
253 
254 					return HANDLER_ERROR;
255 				}
256 
257 				/*
258 				 * proxy.server = ( "<ext>" =>
259 				 *                     ( "<host>" => ( ... ),
260 				 *                       "<host>" => ( ... )
261 				 *                     ),
262 				 *                    "<ext>" => ... )
263 				 */
264 
265 				for (n = 0; n < da_ext->value->used; n++) {
266 					data_array *da_host = (data_array *)da_ext->value->data[n];
267 
268 					data_proxy *df;
269 					data_array *dfa;
270 
271 					config_values_t pcv[] = {
272 						{ "host",              NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },      /* 0 */
273 						{ "port",              NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
274 						{ NULL,                NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
275 					};
276 
277 					if (da_host->type != TYPE_ARRAY) {
278 						log_error_write(srv, __FILE__, __LINE__, "ssSBS",
279 								"unexpected type for key:",
280 								"proxy.server",
281 								"[", da_ext->value->data[n]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
282 
283 						return HANDLER_ERROR;
284 					}
285 
286 					df = data_proxy_init();
287 
288 					df->port = 80;
289 
290 					buffer_copy_buffer(df->key, da_host->key);
291 
292 					pcv[0].destination = df->host;
293 					pcv[1].destination = &(df->port);
294 
295 					if (0 != config_insert_values_internal(srv, da_host->value, pcv, T_CONFIG_SCOPE_CONNECTION)) {
296 						df->free((data_unset*) df);
297 						return HANDLER_ERROR;
298 					}
299 
300 					if (buffer_string_is_empty(df->host)) {
301 						log_error_write(srv, __FILE__, __LINE__, "sbbbs",
302 								"missing key (string):",
303 								da->key,
304 								da_ext->key,
305 								da_host->key,
306 								"host");
307 
308 						df->free((data_unset*) df);
309 						return HANDLER_ERROR;
310 					}
311 
312 					/* if extension already exists, take it */
313 
314 					if (NULL == (dfa = (data_array *)array_get_element(s->extensions, da_ext->key->ptr))) {
315 						dfa = data_array_init();
316 
317 						buffer_copy_buffer(dfa->key, da_ext->key);
318 
319 						array_insert_unique(dfa->value, (data_unset *)df);
320 						array_insert_unique(s->extensions, (data_unset *)dfa);
321 					} else {
322 						array_insert_unique(dfa->value, (data_unset *)df);
323 					}
324 				}
325 			}
326 		}
327 	}
328 
329 	return HANDLER_GO_ON;
330 }
331 
332 static void proxy_connection_close(server *srv, handler_ctx *hctx) {
333 	plugin_data *p;
334 	connection *con;
335 
336 	p    = hctx->plugin_data;
337 	con  = hctx->remote_conn;
338 
339 	if (hctx->fd != -1) {
340 		fdevent_event_del(srv->ev, &(hctx->fde_ndx), hctx->fd);
341 		fdevent_unregister(srv->ev, hctx->fd);
342 
343 		close(hctx->fd);
344 		srv->cur_fds--;
345 	}
346 
347 	if (hctx->host) {
348 		hctx->host->usage--;
349 	}
350 
351 	handler_ctx_free(hctx);
352 	con->plugin_ctx[p->id] = NULL;
353 
354 	/* finish response (if not already finished) */
355 	if (con->mode == p->id
356 	    && (con->state == CON_STATE_HANDLE_REQUEST || con->state == CON_STATE_READ_POST)) {
357 		/* (not CON_STATE_ERROR and not CON_STATE_RESPONSE_END,
358 		 *  i.e. not called from proxy_connection_reset()) */
359 
360 		/* Send an error if we haven't sent any data yet */
361 		if (0 == con->file_started) {
362 			con->http_status = 500;
363 			con->mode = DIRECT;
364 		}
365 		else if (!con->file_finished) {
366 			http_chunk_close(srv, con);
367 			con->file_finished = 1;
368 		}
369 	}
370 }
371 
372 static int proxy_establish_connection(server *srv, handler_ctx *hctx) {
373 	struct sockaddr *proxy_addr;
374 	struct sockaddr_in proxy_addr_in;
375 #if defined(HAVE_SYS_UN_H)
376 	struct sockaddr_un proxy_addr_un;
377 #endif
378 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
379 	struct sockaddr_in6 proxy_addr_in6;
380 #endif
381 	socklen_t servlen;
382 
383 	plugin_data *p    = hctx->plugin_data;
384 	data_proxy *host= hctx->host;
385 	int proxy_fd       = hctx->fd;
386 
387 
388 #if defined(HAVE_SYS_UN_H)
389 	if (strstr(host->host->ptr, "/")) {
390 		if (buffer_string_length(host->host) + 1 > sizeof(proxy_addr_un.sun_path)) {
391 			log_error_write(srv, __FILE__, __LINE__, "sB",
392 				"ERROR: Unix Domain socket filename too long:",
393 				host->host);
394 			return -1;
395 		}
396 
397 		memset(&proxy_addr_un, 0, sizeof(proxy_addr_un));
398 		proxy_addr_un.sun_family = AF_UNIX;
399 		strcpy(proxy_addr_un.sun_path, host->host->ptr);
400 		servlen = sizeof(proxy_addr_un);
401 		proxy_addr = (struct sockaddr *) &proxy_addr_un;
402 	} else
403 #endif
404 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
405 	if (strstr(host->host->ptr, ":")) {
406 		memset(&proxy_addr_in6, 0, sizeof(proxy_addr_in6));
407 		proxy_addr_in6.sin6_family = AF_INET6;
408 		inet_pton(AF_INET6, host->host->ptr, (char *) &proxy_addr_in6.sin6_addr);
409 		proxy_addr_in6.sin6_port = htons(host->port);
410 		servlen = sizeof(proxy_addr_in6);
411 		proxy_addr = (struct sockaddr *) &proxy_addr_in6;
412 	} else
413 #endif
414 	{
415 		memset(&proxy_addr_in, 0, sizeof(proxy_addr_in));
416 		proxy_addr_in.sin_family = AF_INET;
417 		proxy_addr_in.sin_addr.s_addr = inet_addr(host->host->ptr);
418 		proxy_addr_in.sin_port = htons(host->port);
419 		servlen = sizeof(proxy_addr_in);
420 		proxy_addr = (struct sockaddr *) &proxy_addr_in;
421 	}
422 
423 
424 	if (-1 == connect(proxy_fd, proxy_addr, servlen)) {
425 		if (errno == EINPROGRESS || errno == EALREADY) {
426 			if (p->conf.debug) {
427 				log_error_write(srv, __FILE__, __LINE__, "sd",
428 						"connect delayed:", proxy_fd);
429 			}
430 
431 			return 1;
432 		} else {
433 
434 			log_error_write(srv, __FILE__, __LINE__, "sdsd",
435 					"connect failed:", proxy_fd, strerror(errno), errno);
436 
437 			return -1;
438 		}
439 	}
440 	if (p->conf.debug) {
441 		log_error_write(srv, __FILE__, __LINE__, "sd",
442 				"connect succeeded: ", proxy_fd);
443 	}
444 
445 	return 0;
446 }
447 
448 static void proxy_set_header(connection *con, const char *key, const char *value) {
449 	data_string *ds_dst;
450 
451 	if (NULL == (ds_dst = (data_string *)array_get_unused_element(con->request.headers, TYPE_STRING))) {
452 		ds_dst = data_string_init();
453 	}
454 
455 	buffer_copy_string(ds_dst->key, key);
456 	buffer_copy_string(ds_dst->value, value);
457 	array_insert_unique(con->request.headers, (data_unset *)ds_dst);
458 }
459 
460 static void proxy_append_header(connection *con, const char *key, const char *value) {
461 	data_string *ds_dst;
462 
463 	if (NULL == (ds_dst = (data_string *)array_get_unused_element(con->request.headers, TYPE_STRING))) {
464 		ds_dst = data_string_init();
465 	}
466 
467 	buffer_copy_string(ds_dst->key, key);
468 	buffer_append_string(ds_dst->value, value);
469 	array_insert_unique(con->request.headers, (data_unset *)ds_dst);
470 }
471 
472 
473 static int proxy_create_env(server *srv, handler_ctx *hctx) {
474 	size_t i;
475 
476 	connection *con   = hctx->remote_conn;
477 	buffer *b;
478 
479 	/* build header */
480 
481 	b = buffer_init();
482 
483 	/* request line */
484 	buffer_copy_string(b, get_http_method_name(con->request.http_method));
485 	buffer_append_string_len(b, CONST_STR_LEN(" "));
486 
487 	buffer_append_string_buffer(b, con->request.uri);
488 	buffer_append_string_len(b, CONST_STR_LEN(" HTTP/1.0\r\n"));
489 
490 	proxy_append_header(con, "X-Forwarded-For", (char *)inet_ntop_cache_get_ip(srv, &(con->dst_addr)));
491 	/* http_host is NOT is just a pointer to a buffer
492 	 * which is NULL if it is not set */
493 	if (!buffer_string_is_empty(con->request.http_host)) {
494 		proxy_set_header(con, "X-Host", con->request.http_host->ptr);
495 	}
496 	proxy_set_header(con, "X-Forwarded-Proto", con->uri.scheme->ptr);
497 
498 	/* request header */
499 	for (i = 0; i < con->request.headers->used; i++) {
500 		data_string *ds;
501 
502 		ds = (data_string *)con->request.headers->data[i];
503 
504 		if (!buffer_is_empty(ds->value) && !buffer_is_empty(ds->key)) {
505 			if (buffer_is_equal_caseless_string(ds->key, CONST_STR_LEN("Connection"))) continue;
506 			if (buffer_is_equal_caseless_string(ds->key, CONST_STR_LEN("Proxy-Connection"))) continue;
507 
508 			buffer_append_string_buffer(b, ds->key);
509 			buffer_append_string_len(b, CONST_STR_LEN(": "));
510 			buffer_append_string_buffer(b, ds->value);
511 			buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
512 		}
513 	}
514 
515 	buffer_append_string_len(b, CONST_STR_LEN("Connection: close\r\n\r\n"));
516 
517 	chunkqueue_append_buffer(hctx->wb, b);
518 	buffer_free(b);
519 
520 	/* body */
521 
522 	if (con->request.content_length) {
523 		chunkqueue *req_cq = con->request_content_queue;
524 
525 		chunkqueue_steal(hctx->wb, req_cq, req_cq->bytes_in);
526 	}
527 
528 	return 0;
529 }
530 
531 static int proxy_set_state(server *srv, handler_ctx *hctx, proxy_connection_state_t state) {
532 	hctx->state = state;
533 	hctx->state_timestamp = srv->cur_ts;
534 
535 	return 0;
536 }
537 
538 
539 static int proxy_response_parse(server *srv, connection *con, plugin_data *p, buffer *in) {
540 	char *s, *ns;
541 	int http_response_status = -1;
542 
543 	UNUSED(srv);
544 
545 	/* [\r]\n -> [\0]\0 */
546 
547 	buffer_copy_buffer(p->parse_response, in);
548 
549 	for (s = p->parse_response->ptr; NULL != (ns = strchr(s, '\n')); s = ns + 1) {
550 		char *key, *value;
551 		int key_len;
552 		data_string *ds;
553 		int copy_header;
554 
555 		ns[0] = '\0';
556 		if (s != ns && ns[-1] == '\r') ns[-1] = '\0';
557 
558 		if (-1 == http_response_status) {
559 			/* The first line of a Response message is the Status-Line */
560 
561 			for (key=s; *key && *key != ' '; key++);
562 
563 			if (*key) {
564 				http_response_status = (int) strtol(key, NULL, 10);
565 				if (http_response_status < 100 || http_response_status >= 1000) http_response_status = 502;
566 			} else {
567 				http_response_status = 502;
568 			}
569 
570 			con->http_status = http_response_status;
571 			con->parsed_response |= HTTP_STATUS;
572 			continue;
573 		}
574 
575 		if (NULL == (value = strchr(s, ':'))) {
576 			/* now we expect: "<key>: <value>\n" */
577 
578 			continue;
579 		}
580 
581 		key = s;
582 		key_len = value - key;
583 
584 		value++;
585 		/* strip WS */
586 		while (*value == ' ' || *value == '\t') value++;
587 
588 		copy_header = 1;
589 
590 		switch(key_len) {
591 		case 4:
592 			if (0 == strncasecmp(key, "Date", key_len)) {
593 				con->parsed_response |= HTTP_DATE;
594 			}
595 			break;
596 		case 8:
597 			if (0 == strncasecmp(key, "Location", key_len)) {
598 				con->parsed_response |= HTTP_LOCATION;
599 			}
600 			break;
601 		case 10:
602 			if (0 == strncasecmp(key, "Connection", key_len)) {
603 				copy_header = 0;
604 			}
605 			break;
606 		case 14:
607 			if (0 == strncasecmp(key, "Content-Length", key_len)) {
608 				con->response.content_length = strtoul(value, NULL, 10);
609 				con->parsed_response |= HTTP_CONTENT_LENGTH;
610 			}
611 			break;
612 		default:
613 			break;
614 		}
615 
616 		if (copy_header) {
617 			if (NULL == (ds = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
618 				ds = data_response_init();
619 			}
620 			buffer_copy_string_len(ds->key, key, key_len);
621 			buffer_copy_string(ds->value, value);
622 
623 			array_insert_unique(con->response.headers, (data_unset *)ds);
624 		}
625 	}
626 
627 	return 0;
628 }
629 
630 
631 static int proxy_demux_response(server *srv, handler_ctx *hctx) {
632 	int fin = 0;
633 	int b;
634 	ssize_t r;
635 
636 	plugin_data *p    = hctx->plugin_data;
637 	connection *con   = hctx->remote_conn;
638 	int proxy_fd       = hctx->fd;
639 
640 	/* check how much we have to read */
641 	if (ioctl(hctx->fd, FIONREAD, &b)) {
642 		log_error_write(srv, __FILE__, __LINE__, "sd",
643 				"ioctl failed: ",
644 				proxy_fd);
645 		return -1;
646 	}
647 
648 
649 	if (p->conf.debug) {
650 		log_error_write(srv, __FILE__, __LINE__, "sd",
651 				"proxy - have to read:", b);
652 	}
653 
654 	if (b > 0) {
655 		buffer_string_prepare_append(hctx->response, b);
656 
657 		if (-1 == (r = read(hctx->fd, hctx->response->ptr + buffer_string_length(hctx->response), buffer_string_space(hctx->response)))) {
658 			if (errno == EAGAIN) return 0;
659 			log_error_write(srv, __FILE__, __LINE__, "sds",
660 					"unexpected end-of-file (perhaps the proxy process died):",
661 					proxy_fd, strerror(errno));
662 			return -1;
663 		}
664 
665 		/* this should be catched by the b > 0 above */
666 		force_assert(r);
667 
668 		buffer_commit(hctx->response, r);
669 
670 #if 0
671 		log_error_write(srv, __FILE__, __LINE__, "sdsbs",
672 				"demux: Response buffer len", hctx->response->used, ":", hctx->response, ":");
673 #endif
674 
675 		if (0 == con->got_response) {
676 			con->got_response = 1;
677 			buffer_string_prepare_copy(hctx->response_header, 1023);
678 		}
679 
680 		if (0 == con->file_started) {
681 			char *c;
682 
683 			/* search for the \r\n\r\n in the string */
684 			if (NULL != (c = buffer_search_string_len(hctx->response, CONST_STR_LEN("\r\n\r\n")))) {
685 				size_t hlen = c - hctx->response->ptr + 4;
686 				size_t blen = buffer_string_length(hctx->response) - hlen;
687 				/* found */
688 
689 				buffer_append_string_len(hctx->response_header, hctx->response->ptr, hlen);
690 #if 0
691 				log_error_write(srv, __FILE__, __LINE__, "sb", "Header:", hctx->response_header);
692 #endif
693 				/* parse the response header */
694 				proxy_response_parse(srv, con, p, hctx->response_header);
695 
696 				/* enable chunked-transfer-encoding */
697 				if (con->request.http_version == HTTP_VERSION_1_1 &&
698 				    !(con->parsed_response & HTTP_CONTENT_LENGTH)) {
699 					con->response.transfer_encoding = HTTP_TRANSFER_ENCODING_CHUNKED;
700 				}
701 
702 				con->file_started = 1;
703 				if (blen > 0) http_chunk_append_mem(srv, con, c + 4, blen);
704 				buffer_reset(hctx->response);
705 			}
706 		} else {
707 			http_chunk_append_buffer(srv, con, hctx->response);
708 			buffer_reset(hctx->response);
709 		}
710 
711 	} else {
712 		/* reading from upstream done */
713 		con->file_finished = 1;
714 
715 		http_chunk_close(srv, con);
716 
717 		fin = 1;
718 	}
719 
720 	return fin;
721 }
722 
723 
724 static handler_t proxy_write_request(server *srv, handler_ctx *hctx) {
725 	data_proxy *host= hctx->host;
726 	connection *con   = hctx->remote_conn;
727 
728 	int ret;
729 
730 	if (!host || buffer_string_is_empty(host->host) || !host->port) return HANDLER_ERROR;
731 
732 	switch(hctx->state) {
733 	case PROXY_STATE_CONNECT:
734 		/* wait for the connect() to finish */
735 
736 		/* connect failed ? */
737 		if (-1 == hctx->fde_ndx) return HANDLER_ERROR;
738 
739 		/* wait */
740 		return HANDLER_WAIT_FOR_EVENT;
741 
742 	case PROXY_STATE_INIT:
743 #if defined(HAVE_SYS_UN_H)
744 		if (strstr(host->host->ptr,"/")) {
745 			if (-1 == (hctx->fd = socket(AF_UNIX, SOCK_STREAM, 0))) {
746 				log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
747 				return HANDLER_ERROR;
748 			}
749 		} else
750 #endif
751 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
752 		if (strstr(host->host->ptr,":")) {
753 			if (-1 == (hctx->fd = socket(AF_INET6, SOCK_STREAM, 0))) {
754 				log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
755 				return HANDLER_ERROR;
756 			}
757 		} else
758 #endif
759 		{
760 			if (-1 == (hctx->fd = socket(AF_INET, SOCK_STREAM, 0))) {
761 				log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
762 				return HANDLER_ERROR;
763 			}
764 		}
765 		hctx->fde_ndx = -1;
766 
767 		srv->cur_fds++;
768 
769 		fdevent_register(srv->ev, hctx->fd, proxy_handle_fdevent, hctx);
770 
771 		if (-1 == fdevent_fcntl_set(srv->ev, hctx->fd)) {
772 			log_error_write(srv, __FILE__, __LINE__, "ss", "fcntl failed: ", strerror(errno));
773 
774 			return HANDLER_ERROR;
775 		}
776 
777 		switch (proxy_establish_connection(srv, hctx)) {
778 		case 1:
779 			proxy_set_state(srv, hctx, PROXY_STATE_CONNECT);
780 
781 			/* connection is in progress, wait for an event and call getsockopt() below */
782 
783 			fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
784 
785 			return HANDLER_WAIT_FOR_EVENT;
786 		case -1:
787 			/* if ECONNREFUSED choose another connection -> FIXME */
788 			hctx->fde_ndx = -1;
789 
790 			return HANDLER_ERROR;
791 		default:
792 			/* everything is ok, go on */
793 			proxy_set_state(srv, hctx, PROXY_STATE_PREPARE_WRITE);
794 			break;
795 		}
796 
797 		/* fall through */
798 
799 	case PROXY_STATE_PREPARE_WRITE:
800 		proxy_create_env(srv, hctx);
801 
802 		proxy_set_state(srv, hctx, PROXY_STATE_WRITE);
803 
804 		/* fall through */
805 	case PROXY_STATE_WRITE:;
806 		ret = srv->network_backend_write(srv, con, hctx->fd, hctx->wb, MAX_WRITE_LIMIT);
807 
808 		chunkqueue_remove_finished_chunks(hctx->wb);
809 
810 		if (-1 == ret) { /* error on our side */
811 			log_error_write(srv, __FILE__, __LINE__, "ssd", "write failed:", strerror(errno), errno);
812 
813 			return HANDLER_ERROR;
814 		} else if (-2 == ret) { /* remote close */
815 			log_error_write(srv, __FILE__, __LINE__, "ssd", "write failed, remote connection close:", strerror(errno), errno);
816 
817 			return HANDLER_ERROR;
818 		}
819 
820 		if (hctx->wb->bytes_out == hctx->wb->bytes_in) {
821 			proxy_set_state(srv, hctx, PROXY_STATE_READ);
822 			fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
823 		} else {
824 			fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN|FDEVENT_OUT);
825 		}
826 
827 		return HANDLER_WAIT_FOR_EVENT;
828 	case PROXY_STATE_READ:
829 		/* waiting for a response */
830 		return HANDLER_WAIT_FOR_EVENT;
831 	default:
832 		log_error_write(srv, __FILE__, __LINE__, "s", "(debug) unknown state");
833 		return HANDLER_ERROR;
834 	}
835 }
836 
837 #define PATCH(x) \
838 	p->conf.x = s->x;
839 static int mod_proxy_patch_connection(server *srv, connection *con, plugin_data *p) {
840 	size_t i, j;
841 	plugin_config *s = p->config_storage[0];
842 
843 	PATCH(extensions);
844 	PATCH(debug);
845 	PATCH(balance);
846 
847 	/* skip the first, the global context */
848 	for (i = 1; i < srv->config_context->used; i++) {
849 		data_config *dc = (data_config *)srv->config_context->data[i];
850 		s = p->config_storage[i];
851 
852 		/* condition didn't match */
853 		if (!config_check_cond(srv, con, dc)) continue;
854 
855 		/* merge config */
856 		for (j = 0; j < dc->value->used; j++) {
857 			data_unset *du = dc->value->data[j];
858 
859 			if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.server"))) {
860 				PATCH(extensions);
861 			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.debug"))) {
862 				PATCH(debug);
863 			} else if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.balance"))) {
864 				PATCH(balance);
865 			}
866 		}
867 	}
868 
869 	return 0;
870 }
871 #undef PATCH
872 
873 static handler_t proxy_send_request(server *srv, handler_ctx *hctx) {
874 	/* ok, create the request */
875 	handler_t rc = proxy_write_request(srv, hctx);
876 	if (HANDLER_ERROR != rc) {
877 		return rc;
878 	} else {
879 		data_proxy *host = hctx->host;
880 		connection *con  = hctx->remote_conn;
881 		log_error_write(srv, __FILE__, __LINE__,  "sbdd", "proxy-server disabled:",
882 				host->host,
883 				host->port,
884 				hctx->fd);
885 
886 		/* disable this server */
887 		host->is_disabled = 1;
888 		host->disable_ts = srv->cur_ts;
889 
890 		/* reset the enviroment and restart the sub-request */
891 		con->mode = DIRECT;/*(avoid changing con->state, con->http_status)*/
892 		proxy_connection_close(srv, hctx);
893 		con->mode = hctx->plugin_data->id; /* p->id */
894 
895 		return HANDLER_COMEBACK;
896 	}
897 }
898 
899 SUBREQUEST_FUNC(mod_proxy_handle_subrequest) {
900 	plugin_data *p = p_d;
901 
902 	handler_ctx *hctx = con->plugin_ctx[p->id];
903 
904 	if (NULL == hctx) return HANDLER_GO_ON;
905 
906 	/* not my job */
907 	if (con->mode != p->id) return HANDLER_GO_ON;
908 
909 	if (con->state == CON_STATE_READ_POST) {
910 		handler_t r = connection_handle_read_post_state(srv, con);
911 		if (r != HANDLER_GO_ON) return r;
912 	}
913 
914 	return (hctx->state != PROXY_STATE_READ)
915 	  ? proxy_send_request(srv, hctx)
916 	  : HANDLER_WAIT_FOR_EVENT;
917 }
918 
919 static handler_t proxy_handle_fdevent(server *srv, void *ctx, int revents) {
920 	handler_ctx *hctx = ctx;
921 	connection  *con  = hctx->remote_conn;
922 	plugin_data *p    = hctx->plugin_data;
923 
924 	joblist_append(srv, con);
925 
926 	if ((revents & FDEVENT_IN) &&
927 	    hctx->state == PROXY_STATE_READ) {
928 
929 		if (p->conf.debug) {
930 			log_error_write(srv, __FILE__, __LINE__, "sd",
931 					"proxy: fdevent-in", hctx->state);
932 		}
933 
934 		switch (proxy_demux_response(srv, hctx)) {
935 		case 0:
936 			break;
937 		case 1:
938 			/* we are done */
939 			proxy_connection_close(srv, hctx);
940 
941 			return HANDLER_FINISHED;
942 		case -1:
943 			if (con->file_started == 0) {
944 				/* reading response headers failed */
945 			} else {
946 				/* response might have been already started, kill the connection */
947 				con->keep_alive = 0;
948 				con->file_finished = 1;
949 				con->mode = DIRECT; /*(avoid sending final chunked block)*/
950 			}
951 
952 			proxy_connection_close(srv, hctx);
953 
954 			return HANDLER_FINISHED;
955 		}
956 	}
957 
958 	if (revents & FDEVENT_OUT) {
959 		if (p->conf.debug) {
960 			log_error_write(srv, __FILE__, __LINE__, "sd",
961 					"proxy: fdevent-out", hctx->state);
962 		}
963 
964 		if (hctx->state == PROXY_STATE_CONNECT) {
965 			int socket_error;
966 			socklen_t socket_error_len = sizeof(socket_error);
967 
968 			/* try to finish the connect() */
969 			if (0 != getsockopt(hctx->fd, SOL_SOCKET, SO_ERROR, &socket_error, &socket_error_len)) {
970 				log_error_write(srv, __FILE__, __LINE__, "ss",
971 					"getsockopt failed:", strerror(errno));
972 
973 				return HANDLER_FINISHED;
974 			}
975 			if (socket_error != 0) {
976 				log_error_write(srv, __FILE__, __LINE__, "ss",
977 					"establishing connection failed:", strerror(socket_error),
978 					"port:", hctx->host->port);
979 
980 				return HANDLER_FINISHED;
981 			}
982 			if (p->conf.debug) {
983 				log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - connect - delayed success");
984 			}
985 
986 			proxy_set_state(srv, hctx, PROXY_STATE_PREPARE_WRITE);
987 		}
988 
989 		if (hctx->state == PROXY_STATE_PREPARE_WRITE ||
990 		    hctx->state == PROXY_STATE_WRITE) {
991 			/* we are allowed to send something out
992 			 *
993 			 * 1. after a just finished connect() call
994 			 * 2. in a unfinished write() call (long POST request)
995 			 */
996 			return proxy_send_request(srv, hctx); /*(might invalidate hctx)*/
997 		} else {
998 			log_error_write(srv, __FILE__, __LINE__, "sd",
999 					"proxy: out", hctx->state);
1000 		}
1001 	}
1002 
1003 	/* perhaps this issue is already handled */
1004 	if (revents & FDEVENT_HUP) {
1005 		if (p->conf.debug) {
1006 			log_error_write(srv, __FILE__, __LINE__, "sd",
1007 					"proxy: fdevent-hup", hctx->state);
1008 		}
1009 
1010 		if (hctx->state == PROXY_STATE_CONNECT) {
1011 			/* connect() -> EINPROGRESS -> HUP */
1012 
1013 			/**
1014 			 * what is proxy is doing if it can't reach the next hop ?
1015 			 *
1016 			 */
1017 
1018 			if (hctx->host) {
1019 				hctx->host->is_disabled = 1;
1020 				hctx->host->disable_ts = srv->cur_ts;
1021 				log_error_write(srv, __FILE__, __LINE__,  "sbdd", "proxy-server disabled:",
1022 						hctx->host->host,
1023 						hctx->host->port,
1024 						hctx->fd);
1025 
1026 				/* disable this server */
1027 				hctx->host->is_disabled = 1;
1028 				hctx->host->disable_ts = srv->cur_ts;
1029 
1030 				/* reset the environment and restart the sub-request */
1031 				con->mode = DIRECT;/*(avoid changing con->state, con->http_status)*/
1032 				proxy_connection_close(srv, hctx);
1033 				con->mode = p->id;
1034 			} else {
1035 				proxy_connection_close(srv, hctx);
1036 				con->http_status = 503;
1037 			}
1038 		} else {
1039 			proxy_connection_close(srv, hctx);
1040 		}
1041 	} else if (revents & FDEVENT_ERR) {
1042 		log_error_write(srv, __FILE__, __LINE__, "sd", "proxy-FDEVENT_ERR, but no HUP", revents);
1043 
1044 		if (con->file_started) {
1045 			con->keep_alive = 0;
1046 			con->file_finished = 1;
1047 			con->mode = DIRECT; /*(avoid sending final chunked block)*/
1048 		}
1049 		proxy_connection_close(srv, hctx);
1050 	}
1051 
1052 	return HANDLER_FINISHED;
1053 }
1054 
1055 static handler_t mod_proxy_check_extension(server *srv, connection *con, void *p_d) {
1056 	plugin_data *p = p_d;
1057 	size_t s_len;
1058 	unsigned long last_max = ULONG_MAX;
1059 	int max_usage = INT_MAX;
1060 	int ndx = -1;
1061 	size_t k;
1062 	buffer *fn;
1063 	data_array *extension = NULL;
1064 	size_t path_info_offset;
1065 
1066 	if (con->mode != DIRECT) return HANDLER_GO_ON;
1067 
1068 	/* Possibly, we processed already this request */
1069 	if (con->file_started == 1) return HANDLER_GO_ON;
1070 
1071 	mod_proxy_patch_connection(srv, con, p);
1072 
1073 	fn = con->uri.path;
1074 	if (buffer_string_is_empty(fn)) return HANDLER_ERROR;
1075 	s_len = buffer_string_length(fn);
1076 
1077 	path_info_offset = 0;
1078 
1079 	if (p->conf.debug) {
1080 		log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - start");
1081 	}
1082 
1083 	/* check if extension matches */
1084 	for (k = 0; k < p->conf.extensions->used; k++) {
1085 		data_array *ext = NULL;
1086 		size_t ct_len;
1087 
1088 		ext = (data_array *)p->conf.extensions->data[k];
1089 
1090 		if (buffer_is_empty(ext->key)) continue;
1091 
1092 		ct_len = buffer_string_length(ext->key);
1093 
1094 		if (s_len < ct_len) continue;
1095 
1096 		/* check extension in the form "/proxy_pattern" */
1097 		if (*(ext->key->ptr) == '/') {
1098 			if (strncmp(fn->ptr, ext->key->ptr, ct_len) == 0) {
1099 				if (s_len > ct_len + 1) {
1100 					char *pi_offset;
1101 
1102 					if (NULL != (pi_offset = strchr(fn->ptr + ct_len + 1, '/'))) {
1103 						path_info_offset = pi_offset - fn->ptr;
1104 					}
1105 				}
1106 				extension = ext;
1107 				break;
1108 			}
1109 		} else if (0 == strncmp(fn->ptr + s_len - ct_len, ext->key->ptr, ct_len)) {
1110 			/* check extension in the form ".fcg" */
1111 			extension = ext;
1112 			break;
1113 		}
1114 	}
1115 
1116 	if (NULL == extension) {
1117 		return HANDLER_GO_ON;
1118 	}
1119 
1120 	if (p->conf.debug) {
1121 		log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - ext found");
1122 	}
1123 
1124 	if (extension->value->used == 1) {
1125 		if ( ((data_proxy *)extension->value->data[0])->is_disabled ) {
1126 			ndx = -1;
1127 		} else {
1128 			ndx = 0;
1129 		}
1130 	} else if (extension->value->used != 0) switch(p->conf.balance) {
1131 	case PROXY_BALANCE_HASH:
1132 		/* hash balancing */
1133 
1134 		if (p->conf.debug) {
1135 			log_error_write(srv, __FILE__, __LINE__,  "sd",
1136 					"proxy - used hash balancing, hosts:", extension->value->used);
1137 		}
1138 
1139 		for (k = 0, ndx = -1, last_max = ULONG_MAX; k < extension->value->used; k++) {
1140 			data_proxy *host = (data_proxy *)extension->value->data[k];
1141 			unsigned long cur_max;
1142 
1143 			if (host->is_disabled) continue;
1144 
1145 			cur_max = generate_crc32c(CONST_BUF_LEN(con->uri.path)) +
1146 				generate_crc32c(CONST_BUF_LEN(host->host)) + /* we can cache this */
1147 				generate_crc32c(CONST_BUF_LEN(con->uri.authority));
1148 
1149 			if (p->conf.debug) {
1150 				log_error_write(srv, __FILE__, __LINE__,  "sbbbd",
1151 						"proxy - election:",
1152 						con->uri.path,
1153 						host->host,
1154 						con->uri.authority,
1155 						cur_max);
1156 			}
1157 
1158 			if ((last_max == ULONG_MAX) || /* first round */
1159 		   	    (cur_max > last_max)) {
1160 				last_max = cur_max;
1161 
1162 				ndx = k;
1163 			}
1164 		}
1165 
1166 		break;
1167 	case PROXY_BALANCE_FAIR:
1168 		/* fair balancing */
1169 		if (p->conf.debug) {
1170 			log_error_write(srv, __FILE__, __LINE__,  "s",
1171 					"proxy - used fair balancing");
1172 		}
1173 
1174 		for (k = 0, ndx = -1, max_usage = INT_MAX; k < extension->value->used; k++) {
1175 			data_proxy *host = (data_proxy *)extension->value->data[k];
1176 
1177 			if (host->is_disabled) continue;
1178 
1179 			if (host->usage < max_usage) {
1180 				max_usage = host->usage;
1181 
1182 				ndx = k;
1183 			}
1184 		}
1185 
1186 		break;
1187 	case PROXY_BALANCE_RR: {
1188 		data_proxy *host;
1189 
1190 		/* round robin */
1191 		if (p->conf.debug) {
1192 			log_error_write(srv, __FILE__, __LINE__,  "s",
1193 					"proxy - used round-robin balancing");
1194 		}
1195 
1196 		/* just to be sure */
1197 		force_assert(extension->value->used < INT_MAX);
1198 
1199 		host = (data_proxy *)extension->value->data[0];
1200 
1201 		/* Use last_used_ndx from first host in list */
1202 		k = host->last_used_ndx;
1203 		ndx = k + 1; /* use next host after the last one */
1204 		if (ndx < 0) ndx = 0;
1205 
1206 		/* Search first active host after last_used_ndx */
1207 		while ( ndx < (int) extension->value->used
1208 				&& (host = (data_proxy *)extension->value->data[ndx])->is_disabled ) ndx++;
1209 
1210 		if (ndx >= (int) extension->value->used) {
1211 			/* didn't found a higher id, wrap to the start */
1212 			for (ndx = 0; ndx <= (int) k; ndx++) {
1213 				host = (data_proxy *)extension->value->data[ndx];
1214 				if (!host->is_disabled) break;
1215 			}
1216 
1217 			/* No active host found */
1218 			if (host->is_disabled) ndx = -1;
1219 		}
1220 
1221 		/* Save new index for next round */
1222 		((data_proxy *)extension->value->data[0])->last_used_ndx = ndx;
1223 
1224 		break;
1225 	}
1226 	default:
1227 		break;
1228 	}
1229 
1230 	/* found a server */
1231 	if (ndx != -1) {
1232 		data_proxy *host = (data_proxy *)extension->value->data[ndx];
1233 
1234 		/*
1235 		 * if check-local is disabled, use the uri.path handler
1236 		 *
1237 		 */
1238 
1239 		/* init handler-context */
1240 		handler_ctx *hctx;
1241 		hctx = handler_ctx_init();
1242 
1243 		hctx->path_info_offset = path_info_offset;
1244 		hctx->remote_conn      = con;
1245 		hctx->plugin_data      = p;
1246 		hctx->host             = host;
1247 
1248 		con->plugin_ctx[p->id] = hctx;
1249 
1250 		host->usage++;
1251 
1252 		con->mode = p->id;
1253 
1254 		if (p->conf.debug) {
1255 			log_error_write(srv, __FILE__, __LINE__,  "sbd",
1256 					"proxy - found a host",
1257 					host->host, host->port);
1258 		}
1259 
1260 		return HANDLER_GO_ON;
1261 	} else {
1262 		/* no handler found */
1263 		con->http_status = 500;
1264 
1265 		log_error_write(srv, __FILE__, __LINE__,  "sb",
1266 				"no proxy-handler found for:",
1267 				fn);
1268 
1269 		return HANDLER_FINISHED;
1270 	}
1271 	return HANDLER_GO_ON;
1272 }
1273 
1274 static handler_t mod_proxy_connection_reset(server *srv, connection *con, void *p_d) {
1275 	plugin_data *p = p_d;
1276 	handler_ctx *hctx = con->plugin_ctx[p->id];
1277 	if (hctx) proxy_connection_close(srv, hctx);
1278 
1279 	return HANDLER_GO_ON;
1280 }
1281 
1282 /**
1283  *
1284  * the trigger re-enables the disabled connections after the timeout is over
1285  *
1286  * */
1287 
1288 TRIGGER_FUNC(mod_proxy_trigger) {
1289 	plugin_data *p = p_d;
1290 
1291 	if (p->config_storage) {
1292 		size_t i, n, k;
1293 		for (i = 0; i < srv->config_context->used; i++) {
1294 			plugin_config *s = p->config_storage[i];
1295 
1296 			if (!s) continue;
1297 
1298 			/* get the extensions for all configs */
1299 
1300 			for (k = 0; k < s->extensions->used; k++) {
1301 				data_array *extension = (data_array *)s->extensions->data[k];
1302 
1303 				/* get all hosts */
1304 				for (n = 0; n < extension->value->used; n++) {
1305 					data_proxy *host = (data_proxy *)extension->value->data[n];
1306 
1307 					if (!host->is_disabled ||
1308 					    srv->cur_ts - host->disable_ts < 5) continue;
1309 
1310 					log_error_write(srv, __FILE__, __LINE__,  "sbd",
1311 							"proxy - re-enabled:",
1312 							host->host, host->port);
1313 
1314 					host->is_disabled = 0;
1315 				}
1316 			}
1317 		}
1318 	}
1319 
1320 	return HANDLER_GO_ON;
1321 }
1322 
1323 
1324 int mod_proxy_plugin_init(plugin *p);
1325 int mod_proxy_plugin_init(plugin *p) {
1326 	p->version      = LIGHTTPD_VERSION_ID;
1327 	p->name         = buffer_init_string("proxy");
1328 
1329 	p->init         = mod_proxy_init;
1330 	p->cleanup      = mod_proxy_free;
1331 	p->set_defaults = mod_proxy_set_defaults;
1332 	p->connection_reset        = mod_proxy_connection_reset; /* end of req-resp cycle */
1333 	p->handle_connection_close = mod_proxy_connection_reset; /* end of client connection */
1334 	p->handle_uri_clean        = mod_proxy_check_extension;
1335 	p->handle_subrequest       = mod_proxy_handle_subrequest;
1336 	p->handle_trigger          = mod_proxy_trigger;
1337 
1338 	p->data         = NULL;
1339 
1340 	return 0;
1341 }
1342