xref: /lighttpd1.4/src/mod_fastcgi.c (revision dc01487e)
1 #include "first.h"
2 
3 #include <sys/types.h>
4 #include <stdlib.h>
5 #include <string.h>
6 
7 #include "gw_backend.h"
8 typedef gw_plugin_config plugin_config;
9 typedef gw_plugin_data   plugin_data;
10 typedef gw_handler_ctx   handler_ctx;
11 
12 #include "base.h"
13 #include "buffer.h"
14 #include "fdevent.h"
15 #include "http_cgi.h"
16 #include "http_chunk.h"
17 #include "log.h"
18 #include "status_counter.h"
19 
20 #include "compat/fastcgi.h"
21 
22 #if GW_RESPONDER  != FCGI_RESPONDER
23 #error "mismatched defines: (GW_RESPONDER != FCGI_RESPONDER)"
24 #endif
25 #if GW_AUTHORIZER != FCGI_AUTHORIZER
26 #error "mismatched defines: (GW_AUTHORIZER != FCGI_AUTHORIZER)"
27 #endif
28 #if GW_FILTER     != FCGI_FILTER
29 #error "mismatched defines: (GW_FILTER != FCGI_FILTER)"
30 #endif
31 
32 static void mod_fastcgi_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) {
33     switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
34       case 0: /* fastcgi.server */
35         if (cpv->vtype == T_CONFIG_LOCAL) {
36             gw_plugin_config * const gw = cpv->v.v;
37             pconf->exts      = gw->exts;
38             pconf->exts_auth = gw->exts_auth;
39             pconf->exts_resp = gw->exts_resp;
40         }
41         break;
42       case 1: /* fastcgi.balance */
43         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
44             pconf->balance = (int)cpv->v.u;
45         break;
46       case 2: /* fastcgi.debug */
47         pconf->debug = (int)cpv->v.u;
48         break;
49       case 3: /* fastcgi.map-extensions */
50         pconf->ext_mapping = cpv->v.a;
51         break;
52       default:/* should not happen */
53         return;
54     }
55 }
56 
57 static void mod_fastcgi_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) {
58     do {
59         mod_fastcgi_merge_config_cpv(pconf, cpv);
60     } while ((++cpv)->k_id != -1);
61 }
62 
63 static void mod_fastcgi_patch_config(request_st * const r, plugin_data * const p) {
64     memcpy(&p->conf, &p->defaults, sizeof(plugin_config));
65     for (int i = 1, used = p->nconfig; i < used; ++i) {
66         if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
67             mod_fastcgi_merge_config(&p->conf,p->cvlist + p->cvlist[i].v.u2[0]);
68     }
69 }
70 
71 SETDEFAULTS_FUNC(mod_fastcgi_set_defaults) {
72     static const config_plugin_keys_t cpk[] = {
73       { CONST_STR_LEN("fastcgi.server"),
74         T_CONFIG_ARRAY_KVARRAY,
75         T_CONFIG_SCOPE_CONNECTION }
76      ,{ CONST_STR_LEN("fastcgi.balance"),
77         T_CONFIG_STRING,
78         T_CONFIG_SCOPE_CONNECTION }
79      ,{ CONST_STR_LEN("fastcgi.debug"),
80         T_CONFIG_INT,
81         T_CONFIG_SCOPE_CONNECTION }
82      ,{ CONST_STR_LEN("fastcgi.map-extensions"),
83         T_CONFIG_ARRAY_KVSTRING,
84         T_CONFIG_SCOPE_CONNECTION }
85      ,{ NULL, 0,
86         T_CONFIG_UNSET,
87         T_CONFIG_SCOPE_UNSET }
88     };
89 
90     plugin_data * const p = p_d;
91     if (!config_plugin_values_init(srv, p, cpk, "mod_fastcgi"))
92         return HANDLER_ERROR;
93 
94     /* process and validate config directives
95      * (init i to 0 if global context; to 1 to skip empty global context) */
96     for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
97         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
98         for (; -1 != cpv->k_id; ++cpv) {
99             switch (cpv->k_id) {
100               case 0:{/* fastcgi.server */
101                 gw_plugin_config *gw = calloc(1, sizeof(gw_plugin_config));
102                 force_assert(gw);
103                 if (!gw_set_defaults_backend(srv, p, cpv->v.a, gw, 0,
104                                              cpk[cpv->k_id].k)) {
105                     gw_plugin_config_free(gw);
106                     return HANDLER_ERROR;
107                 }
108                 cpv->v.v = gw;
109                 cpv->vtype = T_CONFIG_LOCAL;
110                 break;
111               }
112               case 1: /* fastcgi.balance */
113                 cpv->v.u = (unsigned int)gw_get_defaults_balance(srv, cpv->v.b);
114                 break;
115               case 2: /* fastcgi.debug */
116               case 3: /* fastcgi.map-extensions */
117                 break;
118               default:/* should not happen */
119                 break;
120             }
121         }
122     }
123 
124     /* default is 0 */
125     /*p->defaults.balance = (unsigned int)gw_get_defaults_balance(srv, NULL);*/
126 
127     /* initialize p->defaults from global config context */
128     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
129         const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
130         if (-1 != cpv->k_id)
131             mod_fastcgi_merge_config(&p->defaults, cpv);
132     }
133 
134     return HANDLER_GO_ON;
135 }
136 
137 
138 static int fcgi_env_add(void *venv, const char *key, size_t key_len, const char *val, size_t val_len) {
139 	buffer *env = venv;
140 	char len_enc[8];
141 	size_t len_enc_len = 0;
142 
143 	if (!key || (!val && val_len)) return -1;
144 
145 	/**
146 	 * field length can be 31bit max
147 	 *
148 	 * HINT: this can't happen as FCGI_MAX_LENGTH is only 16bit
149 	 */
150 	force_assert(key_len < 0x7fffffffu);
151 	force_assert(val_len < 0x7fffffffu);
152 
153 	if (key_len > 127) {
154 		len_enc[0] = ((key_len >> 24) & 0xff) | 0x80;
155 		len_enc[1] =  (key_len >> 16) & 0xff;
156 		len_enc[2] =  (key_len >>  8) & 0xff;
157 		len_enc_len += 3;
158 	}
159 	len_enc[len_enc_len++] = key_len & 0xff;
160 
161 	if (val_len > 127) {
162 		len_enc[len_enc_len++] = ((val_len >> 24) & 0xff) | 0x80;
163 		len_enc[len_enc_len++] = (val_len >> 16) & 0xff;
164 		len_enc[len_enc_len++] = (val_len >> 8) & 0xff;
165 	}
166 	len_enc[len_enc_len++] = val_len & 0xff;
167 
168 	const size_t len = len_enc_len + key_len + val_len;
169 	const size_t fmax =
170 	  FCGI_MAX_LENGTH + sizeof(FCGI_BeginRequestRecord) + sizeof(FCGI_Header);
171 	if (buffer_string_length(env) + len >= fmax)
172 		return -1; /* we can't append more headers, ignore it */
173 
174 	buffer_append_str3(env, len_enc, len_enc_len, key, key_len, val, val_len);
175 	return 0;
176 }
177 
178 static void fcgi_header(FCGI_Header * header, unsigned char type, int request_id, int contentLength, unsigned char paddingLength) {
179 	force_assert(contentLength <= FCGI_MAX_LENGTH);
180 
181 	header->version = FCGI_VERSION_1;
182 	header->type = type;
183 	header->requestIdB0 = request_id & 0xff;
184 	header->requestIdB1 = (request_id >> 8) & 0xff;
185 	header->contentLengthB0 = contentLength & 0xff;
186 	header->contentLengthB1 = (contentLength >> 8) & 0xff;
187 	header->paddingLength = paddingLength;
188 	header->reserved = 0;
189 }
190 
191 static handler_t fcgi_stdin_append(handler_ctx *hctx) {
192 	FCGI_Header header;
193 	chunkqueue * const req_cq = &hctx->r->reqbody_queue;
194 	off_t offset, weWant;
195 	off_t req_cqlen = chunkqueue_length(req_cq);
196 	int request_id = hctx->request_id;
197 	if (req_cqlen > MAX_WRITE_LIMIT) req_cqlen = MAX_WRITE_LIMIT;
198 
199 	/* something to send ? */
200 	for (offset = 0; offset != req_cqlen; offset += weWant) {
201 		weWant = req_cqlen - offset > FCGI_MAX_LENGTH ? FCGI_MAX_LENGTH : req_cqlen - offset;
202 
203 		if (-1 != hctx->wb_reqlen) {
204 			if (hctx->wb_reqlen >= 0) {
205 				hctx->wb_reqlen += sizeof(header);
206 			} else {
207 				hctx->wb_reqlen -= sizeof(header);
208 			}
209 		}
210 
211 		fcgi_header(&(header), FCGI_STDIN, request_id, weWant, 0);
212 		(chunkqueue_is_empty(&hctx->wb) || hctx->wb.first->type == MEM_CHUNK) /* else FILE_CHUNK for temp file */
213 		  ? chunkqueue_append_mem(&hctx->wb, (const char *)&header, sizeof(header))
214 		  : chunkqueue_append_mem_min(&hctx->wb, (const char *)&header, sizeof(header));
215 		chunkqueue_steal(&hctx->wb, req_cq, weWant);
216 		/*(hctx->wb_reqlen already includes reqbody_length)*/
217 	}
218 
219 	if (hctx->wb.bytes_in == hctx->wb_reqlen) {
220 		/* terminate STDIN */
221 		/* (future: must defer ending FCGI_STDIN
222 		 *  if might later upgrade protocols
223 		 *  and then have more data to send) */
224 		fcgi_header(&(header), FCGI_STDIN, request_id, 0, 0);
225 		chunkqueue_append_mem(&hctx->wb, (const char *)&header, sizeof(header));
226 		hctx->wb_reqlen += (int)sizeof(header);
227 	}
228 
229 	return HANDLER_GO_ON;
230 }
231 
232 static handler_t fcgi_create_env(handler_ctx *hctx) {
233 	FCGI_BeginRequestRecord beginRecord;
234 	FCGI_Header header;
235 	int request_id;
236 
237 	gw_host *host = hctx->host;
238 	request_st * const r = hctx->r;
239 
240 	http_cgi_opts opts = {
241 	  (hctx->gw_mode == FCGI_AUTHORIZER),
242 	  host->break_scriptfilename_for_php,
243 	  host->docroot,
244 	  host->strip_request_uri
245 	};
246 
247 	size_t rsz = (size_t)(r->read_queue.bytes_out - hctx->wb.bytes_in);
248 	if (rsz >= 65536) rsz = r->rqst_header_len;
249 	buffer * const b = chunkqueue_prepend_buffer_open_sz(&hctx->wb, rsz);
250 
251 	/* send FCGI_BEGIN_REQUEST */
252 
253 	if (hctx->request_id == 0) {
254 		hctx->request_id = 1; /* always use id 1 as we don't use multiplexing */
255 	} else {
256 		log_error(r->conf.errh, __FILE__, __LINE__,
257 		  "fcgi-request is already in use: %d", hctx->request_id);
258 	}
259 	request_id = hctx->request_id;
260 
261 	fcgi_header(&(beginRecord.header), FCGI_BEGIN_REQUEST, request_id, sizeof(beginRecord.body), 0);
262 	beginRecord.body.roleB0 = hctx->gw_mode;
263 	beginRecord.body.roleB1 = 0;
264 	beginRecord.body.flags = 0;
265 	memset(beginRecord.body.reserved, 0, sizeof(beginRecord.body.reserved));
266 	fcgi_header(&header, FCGI_PARAMS, request_id, 0, 0); /*(set aside space to fill in later)*/
267 	buffer_append_str2(b, (const char *)&beginRecord, sizeof(beginRecord),
268 	                      (const char *)&header,      sizeof(header));
269 
270 	/* send FCGI_PARAMS */
271 
272 	if (0 != http_cgi_headers(r, &opts, fcgi_env_add, b)) {
273 		r->http_status = 400;
274 		r->handler_module = NULL;
275 		buffer_clear(b);
276 		chunkqueue_remove_finished_chunks(&hctx->wb);
277 		return HANDLER_FINISHED;
278 	} else {
279 		fcgi_header(&(header), FCGI_PARAMS, request_id,
280 			    buffer_string_length(b) - sizeof(FCGI_BeginRequestRecord) - sizeof(FCGI_Header), 0);
281 		memcpy(b->ptr+sizeof(FCGI_BeginRequestRecord), (const char *)&header, sizeof(header));
282 
283 		fcgi_header(&(header), FCGI_PARAMS, request_id, 0, 0);
284 		buffer_append_string_len(b, (const char *)&header, sizeof(header));
285 
286 		hctx->wb_reqlen = buffer_string_length(b);
287 		chunkqueue_prepend_buffer_commit(&hctx->wb);
288 	}
289 
290 	if (r->reqbody_length) {
291 		/*chunkqueue_append_chunkqueue(&hctx->wb, &r->reqbody_queue);*/
292 		if (r->reqbody_length > 0)
293 			hctx->wb_reqlen += r->reqbody_length;/* (eventual) (minimal) total request size, not necessarily including all fcgi_headers around content length yet */
294 		else /* as-yet-unknown total request size (Transfer-Encoding: chunked)*/
295 			hctx->wb_reqlen = -hctx->wb_reqlen;
296 	}
297 	fcgi_stdin_append(hctx);
298 
299 	status_counter_inc(CONST_STR_LEN("fastcgi.requests"));
300 	return HANDLER_GO_ON;
301 }
302 
303 typedef struct {
304 	unsigned int len;
305 	int      type;
306 	int      padding;
307 	int      request_id;
308 } fastcgi_response_packet;
309 
310 static int fastcgi_get_packet(handler_ctx *hctx, fastcgi_response_packet *packet) {
311 	FCGI_Header header;
312 	off_t rblen = chunkqueue_length(hctx->rb);
313 	if (rblen < (off_t)sizeof(FCGI_Header)) {
314 		/* no header */
315 		if (hctx->conf.debug && 0 != rblen) {
316 			log_error(hctx->r->conf.errh, __FILE__, __LINE__,
317 			  "FastCGI: header too small: %lld bytes < %zu bytes, "
318 			  "waiting for more data", (long long)rblen, sizeof(FCGI_Header));
319 		}
320 		return -1;
321 	}
322 	char *ptr = (char *)&header;
323 	uint32_t rd = sizeof(FCGI_Header);
324 	if (chunkqueue_peek_data(hctx->rb, &ptr, &rd, hctx->r->conf.errh) < 0)
325 		return -1;
326 	if (rd != sizeof(FCGI_Header))
327 		return -1;
328 	if (ptr != (char *)&header) /* copy into aligned struct */
329 		memcpy(&header, ptr, sizeof(FCGI_Header));
330 
331 	/* we have at least a header, now check how much we have to fetch */
332 	packet->len = (header.contentLengthB0 | (header.contentLengthB1 << 8)) + header.paddingLength;
333 	packet->request_id = (header.requestIdB0 | (header.requestIdB1 << 8));
334 	packet->type = header.type;
335 	packet->padding = header.paddingLength;
336 
337 	if (packet->len > (unsigned int)rblen-sizeof(FCGI_Header)) {
338 		return -1; /* we didn't get the full packet */
339 	}
340 
341 	chunkqueue_mark_written(hctx->rb, sizeof(FCGI_Header));
342 	return 0;
343 }
344 
345 static void fastcgi_get_packet_body(buffer * const b, handler_ctx * const hctx, const fastcgi_response_packet * const packet) {
346     /* copy content; hctx->rb must contain at least packet->len content */
347     /* (read entire packet and then truncate padding, if present) */
348     const uint32_t blen = buffer_string_length(b);
349     if (chunkqueue_read_data(hctx->rb,
350                              buffer_string_prepare_append(b, packet->len),
351                              packet->len, hctx->r->conf.errh) < 0)
352         return; /*(should not happen; should all be in memory)*/
353     buffer_string_set_length(b, blen + packet->len - packet->padding);
354 }
355 
356 __attribute_cold__
357 __attribute_noinline__
358 static int
359 mod_fastcgi_chunk_decode_transfer_cqlen (request_st * const r, chunkqueue * const src, const unsigned int len)
360 {
361     if (0 == len) return 0;
362 
363     /* specialized for mod_fastcgi to decode chunked encoding;
364      * FastCGI packet data is all type MEM_CHUNK
365      * entire src cq is processed, minus packet.padding at end
366      * (This extra work can be avoided if FastCGI backend does not send
367      *  Transfer-Encoding: chunked, which FastCGI is not supposed to do) */
368     uint32_t remain = len, wr;
369     for (const chunk *c = src->first; c && remain; c = c->next, remain -= wr) {
370         /*assert(c->type == MEM_CHUNK);*/
371         wr = buffer_string_length(c->mem) - c->offset;
372         if (wr > remain) wr = remain;
373         if (0 != http_chunk_decode_append_mem(r, c->mem->ptr+c->offset, wr))
374             return -1;
375     }
376     chunkqueue_mark_written(src, len);
377     return 0;
378 }
379 
380 static int
381 mod_fastcgi_transfer_cqlen (request_st * const r, chunkqueue * const src, const unsigned int len)
382 {
383     return (!r->resp_decode_chunked)
384       ? http_chunk_transfer_cqlen(r, src, len)
385       : mod_fastcgi_chunk_decode_transfer_cqlen(r, src, len);
386 }
387 
388 static handler_t fcgi_recv_parse(request_st * const r, struct http_response_opts_t *opts, buffer *b, size_t n) {
389 	handler_ctx *hctx = (handler_ctx *)opts->pdata;
390 	int fin = 0;
391 
392 	if (0 == n) {
393 		if (-1 == hctx->request_id) return HANDLER_FINISHED; /*(flag request ended)*/
394 		if (!(fdevent_fdnode_interest(hctx->fdn) & FDEVENT_IN)
395 		    && !(r->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_POLLRDHUP))
396 			return HANDLER_GO_ON;
397 		log_error(r->conf.errh, __FILE__, __LINE__,
398 		  "unexpected end-of-file (perhaps the fastcgi process died):"
399 		  "pid: %d socket: %s",
400 		  hctx->proc->pid, hctx->proc->connection_name->ptr);
401 
402 		return HANDLER_ERROR;
403 	}
404 
405 	chunkqueue_append_buffer(hctx->rb, b);
406 
407 	/*
408 	 * parse the fastcgi packets and forward the content to the write-queue
409 	 *
410 	 */
411 	while (fin == 0) {
412 		fastcgi_response_packet packet;
413 
414 		/* check if we have at least one packet */
415 		if (0 != fastcgi_get_packet(hctx, &packet)) {
416 			/* no full packet */
417 			break;
418 		}
419 
420 		switch(packet.type) {
421 		case FCGI_STDOUT:
422 			if (packet.len == 0) break;
423 
424 			/* is the header already finished */
425 			if (0 == r->resp_body_started) {
426 				/* split header from body */
427 				buffer *hdrs = hctx->response;
428 				if (NULL == hdrs) {
429 					hdrs = r->tmp_buf;
430 					buffer_clear(hdrs);
431 				}
432 				fastcgi_get_packet_body(hdrs, hctx, &packet);
433 				if (HANDLER_GO_ON != http_response_parse_headers(r, &hctx->opts, hdrs)) {
434 					hctx->send_content_body = 0;
435 					fin = 1;
436 					break;
437 				}
438 				if (0 == r->resp_body_started) {
439 					if (!hctx->response) {
440 						hctx->response = chunk_buffer_acquire();
441 						buffer_copy_buffer(hctx->response, hdrs);
442 					}
443 				}
444 				else if (hctx->gw_mode == GW_AUTHORIZER &&
445 					 (r->http_status == 0 || r->http_status == 200)) {
446 					/* authorizer approved request; ignore the content here */
447 					hctx->send_content_body = 0;
448 				}
449 			} else if (hctx->send_content_body) {
450 				if (0 != mod_fastcgi_transfer_cqlen(r, hctx->rb, packet.len - packet.padding)) {
451 					/* error writing to tempfile;
452 					 * truncate response or send 500 if nothing sent yet */
453 					fin = 1;
454 				}
455 				if (packet.padding) chunkqueue_mark_written(hctx->rb, packet.padding);
456 			} else {
457 				chunkqueue_mark_written(hctx->rb, packet.len);
458 			}
459 			break;
460 		case FCGI_STDERR:
461 			if (packet.len) {
462 				buffer * const tb = r->tmp_buf;
463 				buffer_clear(tb);
464 				fastcgi_get_packet_body(tb, hctx, &packet);
465 				log_error_multiline_buffer(r->conf.errh, __FILE__, __LINE__, tb,
466 				  "FastCGI-stderr:");
467 			}
468 			break;
469 		case FCGI_END_REQUEST:
470 			hctx->request_id = -1; /*(flag request ended)*/
471 			fin = 1;
472 			break;
473 		default:
474 			log_error(r->conf.errh, __FILE__, __LINE__,
475 			  "FastCGI: header.type not handled: %d", packet.type);
476 			chunkqueue_mark_written(hctx->rb, packet.len);
477 			break;
478 		}
479 	}
480 
481 	return 0 == fin ? HANDLER_GO_ON : HANDLER_FINISHED;
482 }
483 
484 static handler_t fcgi_check_extension(request_st * const r, void *p_d, int uri_path_handler) {
485 	plugin_data *p = p_d;
486 	handler_t rc;
487 
488 	if (NULL != r->handler_module) return HANDLER_GO_ON;
489 
490 	mod_fastcgi_patch_config(r, p);
491 	if (NULL == p->conf.exts) return HANDLER_GO_ON;
492 
493 	rc = gw_check_extension(r, p, uri_path_handler, 0);
494 	if (HANDLER_GO_ON != rc) return rc;
495 
496 	if (r->handler_module == p->self) {
497 		handler_ctx *hctx = r->plugin_ctx[p->id];
498 		hctx->opts.backend = BACKEND_FASTCGI;
499 		hctx->opts.parse = fcgi_recv_parse;
500 		hctx->opts.pdata = hctx;
501 		hctx->stdin_append = fcgi_stdin_append;
502 		hctx->create_env = fcgi_create_env;
503 		if (!hctx->rb) {
504 			hctx->rb = chunkqueue_init(NULL);
505 		}
506 		else {
507 			chunkqueue_reset(hctx->rb);
508 		}
509 	}
510 
511 	return HANDLER_GO_ON;
512 }
513 
514 /* uri-path handler */
515 static handler_t fcgi_check_extension_1(request_st * const r, void *p_d) {
516 	return fcgi_check_extension(r, p_d, 1);
517 }
518 
519 /* start request handler */
520 static handler_t fcgi_check_extension_2(request_st * const r, void *p_d) {
521 	return fcgi_check_extension(r, p_d, 0);
522 }
523 
524 
525 int mod_fastcgi_plugin_init(plugin *p);
526 int mod_fastcgi_plugin_init(plugin *p) {
527 	p->version      = LIGHTTPD_VERSION_ID;
528 	p->name         = "fastcgi";
529 
530 	p->init         = gw_init;
531 	p->cleanup      = gw_free;
532 	p->set_defaults = mod_fastcgi_set_defaults;
533 	p->handle_request_reset    = gw_handle_request_reset;
534 	p->handle_uri_clean        = fcgi_check_extension_1;
535 	p->handle_subrequest_start = fcgi_check_extension_2;
536 	p->handle_subrequest       = gw_handle_subrequest;
537 	p->handle_trigger          = gw_handle_trigger;
538 	p->handle_waitpid          = gw_handle_waitpid_cb;
539 
540 	return 0;
541 }
542