xref: /lighttpd1.4/src/mod_cgi.c (revision ec50657e)
1 #include "first.h"
2 
3 #include "base.h"
4 #include "stat_cache.h"
5 #include "http_kv.h"
6 #include "fdlog.h"
7 #include "log.h"
8 #include "response.h"
9 #include "http_cgi.h"
10 #include "http_chunk.h"
11 #include "http_header.h"
12 
13 #include "plugin.h"
14 
15 #include <sys/types.h>
16 #include "sys-socket.h"
17 #ifdef HAVE_SYS_WAIT_H
18 #include <sys/wait.h>
19 #endif
20 
21 #include <unistd.h>
22 #include <errno.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <fdevent.h>
26 
27 #include <fcntl.h>
28 #include <signal.h>
29 
30 typedef struct {
31 	uintptr_t *offsets;
32 	size_t osize;
33 	size_t oused;
34 	buffer *b;
35 	buffer *boffsets;
36 	buffer *ld_preload;
37 	buffer *ld_library_path;
38       #ifdef __CYGWIN__
39 	buffer *systemroot;
40       #endif
41 } env_accum;
42 
43 typedef struct {
44 	unix_time64_t read_timeout;
45 	unix_time64_t write_timeout;
46 	int signal_fin;
47 } cgi_limits;
48 
49 typedef struct {
50 	const array *cgi;
51 	const cgi_limits *limits;
52 	unsigned short execute_x_only;
53 	unsigned short local_redir;
54 	unsigned short xsendfile_allow;
55 	unsigned short upgrade;
56 	const array *xsendfile_docroot;
57 } plugin_config;
58 
59 struct cgi_pid_t;
60 
61 typedef struct {
62 	PLUGIN_DATA;
63 	plugin_config defaults;
64 	plugin_config conf;
65 	int tempfile_accum;
66 	struct cgi_pid_t *cgi_pid;
67 	env_accum env;
68 } plugin_data;
69 
70 typedef struct {
71 	struct cgi_pid_t *cgi_pid;
72 	int fd;
73 	int fdtocgi;
74 	int rd_revents;
75 	int wr_revents;
76 	fdnode *fdn;
77 	fdnode *fdntocgi;
78 
79 	request_st *r;
80 	connection *con;          /* dumb pointer */
81 	struct fdevents *ev;      /* dumb pointer */
82 	plugin_data *plugin_data; /* dumb pointer */
83 
84 	buffer *response;
85 	unix_time64_t read_ts;
86 	unix_time64_t write_ts;
87 	buffer *cgi_handler;      /* dumb pointer */
88 	http_response_opts opts;
89 	plugin_config conf;
90 } handler_ctx;
91 
92 typedef struct cgi_pid_t {
93 	pid_t pid;
94 	int signal_sent;
95 	handler_ctx *hctx;
96 	struct cgi_pid_t *next;
97 	struct cgi_pid_t *prev;
98 } cgi_pid_t;
99 
100 static handler_ctx * cgi_handler_ctx_init(void) {
101 	handler_ctx *hctx = calloc(1, sizeof(*hctx));
102 
103 	force_assert(hctx);
104 
105 	hctx->response = chunk_buffer_acquire();
106 	hctx->fd = -1;
107 	hctx->fdtocgi = -1;
108 
109 	return hctx;
110 }
111 
112 static void cgi_handler_ctx_free(handler_ctx *hctx) {
113 	chunk_buffer_release(hctx->response);
114 	free(hctx);
115 }
116 
117 INIT_FUNC(mod_cgi_init) {
118 	plugin_data *p;
119 	const char *s;
120 
121 	p = calloc(1, sizeof(*p));
122 
123 	force_assert(p);
124 
125 	/* for valgrind */
126 	s = getenv("LD_PRELOAD");
127 	if (s) p->env.ld_preload = buffer_init_string(s);
128 	s = getenv("LD_LIBRARY_PATH");
129 	if (s) p->env.ld_library_path = buffer_init_string(s);
130       #ifdef __CYGWIN__
131 	/* CYGWIN needs SYSTEMROOT */
132 	s = getenv("SYSTEMROOT");
133 	if (s) p->env.systemroot = buffer_init_string(s);
134       #endif
135 
136 	return p;
137 }
138 
139 
140 FREE_FUNC(mod_cgi_free) {
141 	plugin_data *p = p_d;
142 	buffer_free(p->env.ld_preload);
143 	buffer_free(p->env.ld_library_path);
144       #ifdef __CYGWIN__
145 	buffer_free(p->env.systemroot);
146       #endif
147 
148     for (cgi_pid_t *cgi_pid = p->cgi_pid, *next; cgi_pid; cgi_pid = next) {
149         next = cgi_pid->next;
150         free(cgi_pid);
151     }
152 
153     if (NULL == p->cvlist) return;
154     /* (init i to 0 if global context; to 1 to skip empty global context) */
155     for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
156         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
157         for (; -1 != cpv->k_id; ++cpv) {
158             if (cpv->vtype != T_CONFIG_LOCAL || NULL == cpv->v.v) continue;
159             switch (cpv->k_id) {
160               case 6: /* cgi.limits */
161                 free(cpv->v.v);
162                 break;
163               default:
164                 break;
165             }
166         }
167     }
168 }
169 
170 static void mod_cgi_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) {
171     switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
172       case 0: /* cgi.assign */
173         pconf->cgi = cpv->v.a;
174         break;
175       case 1: /* cgi.execute-x-only */
176         pconf->execute_x_only = (unsigned short)cpv->v.u;
177         break;
178       case 2: /* cgi.x-sendfile */
179         pconf->xsendfile_allow = (unsigned short)cpv->v.u;
180         break;
181       case 3: /* cgi.x-sendfile-docroot */
182         pconf->xsendfile_docroot = cpv->v.a;
183         break;
184       case 4: /* cgi.local-redir */
185         pconf->local_redir = (unsigned short)cpv->v.u;
186         break;
187       case 5: /* cgi.upgrade */
188         pconf->upgrade = (unsigned short)cpv->v.u;
189         break;
190       case 6: /* cgi.limits */
191         if (cpv->vtype != T_CONFIG_LOCAL) break;
192         pconf->limits = cpv->v.v;
193         break;
194       default:/* should not happen */
195         return;
196     }
197 }
198 
199 static void mod_cgi_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) {
200     do {
201         mod_cgi_merge_config_cpv(pconf, cpv);
202     } while ((++cpv)->k_id != -1);
203 }
204 
205 static void mod_cgi_patch_config(request_st * const r, plugin_data * const p) {
206     p->conf = p->defaults; /* copy small struct instead of memcpy() */
207     /*memcpy(&p->conf, &p->defaults, sizeof(plugin_config));*/
208     for (int i = 1, used = p->nconfig; i < used; ++i) {
209         if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
210             mod_cgi_merge_config(&p->conf, p->cvlist + p->cvlist[i].v.u2[0]);
211     }
212 }
213 
214 __attribute_cold__
215 __attribute_pure__
216 static int mod_cgi_str_to_signal (const char *s, int default_sig) {
217     static const struct { const char *name; int sig; } sigs[] = {
218       { "HUP",  SIGHUP  }
219      ,{ "INT",  SIGINT  }
220      ,{ "QUIT", SIGQUIT }
221      ,{ "ILL",  SIGILL  }
222      ,{ "TRAP", SIGTRAP }
223      ,{ "ABRT", SIGABRT }
224      #ifdef SIGBUS
225      ,{ "BUS",  SIGBUS  }
226      #endif
227      ,{ "FPE",  SIGFPE  }
228      ,{ "KILL", SIGKILL }
229      #ifdef SIGUSR1
230      ,{ "USR1", SIGUSR1 }
231      #endif
232      ,{ "SEGV", SIGSEGV }
233      #ifdef SIGUSR2
234      ,{ "USR2", SIGUSR2 }
235      #endif
236      ,{ "PIPE", SIGPIPE }
237      ,{ "ALRM", SIGALRM }
238      ,{ "TERM", SIGTERM }
239      #ifdef SIGCHLD
240      ,{ "CHLD", SIGCHLD }
241      #endif
242      #ifdef SIGCONT
243      ,{ "CONT", SIGCONT }
244      #endif
245      #ifdef SIGURG
246      ,{ "URG",  SIGURG  }
247      #endif
248      #ifdef SIGXCPU
249      ,{ "XCPU", SIGXCPU }
250      #endif
251      #ifdef SIGXFSZ
252      ,{ "XFSZ", SIGXFSZ }
253      #endif
254      #ifdef SIGWINCH
255      ,{ "WINCH",SIGWINCH}
256      #endif
257      #ifdef SIGPOLL
258      ,{ "POLL", SIGPOLL }
259      #endif
260      #ifdef SIGIO
261      ,{ "IO",   SIGIO   }
262      #endif
263     };
264 
265     if (s[0] == 'S' && s[1] == 'I' && s[2] == 'G') s += 3; /*("SIG" prefix)*/
266     for (uint32_t i = 0; i < sizeof(sigs)/sizeof(*sigs); ++i) {
267         if (0 == strcmp(s, sigs[i].name)) return sigs[i].sig;
268     }
269     return default_sig;
270 }
271 
272 static cgi_limits * mod_cgi_parse_limits(const array * const a, log_error_st * const errh) {
273     cgi_limits * const limits = calloc(1, sizeof(cgi_limits));
274     force_assert(limits);
275     for (uint32_t i = 0; i < a->used; ++i) {
276         const data_unset * const du = a->data[i];
277         int32_t v = config_plugin_value_to_int32(du, -1);
278         if (buffer_eq_icase_slen(&du->key, CONST_STR_LEN("read-timeout"))) {
279             limits->read_timeout = (unix_time64_t)v;
280             continue;
281         }
282         if (buffer_eq_icase_slen(&du->key, CONST_STR_LEN("write-timeout"))) {
283             limits->write_timeout = (unix_time64_t)v;
284             continue;
285         }
286         if (buffer_eq_icase_slen(&du->key, CONST_STR_LEN("tcp-fin-propagate"))) {
287             if (-1 == v) {
288                 v = SIGTERM;
289                 if (du->type == TYPE_STRING) {
290                     buffer * const vstr = &((data_string *)du)->value;
291                     buffer_to_upper(vstr);
292                     v = mod_cgi_str_to_signal(vstr->ptr, SIGTERM);
293                 }
294             }
295             limits->signal_fin = v;
296             continue;
297         }
298         log_error(errh, __FILE__, __LINE__,
299                   "unrecognized cgi.limits param: %s", du->key.ptr);
300     }
301     return limits;
302 }
303 
304 SETDEFAULTS_FUNC(mod_cgi_set_defaults) {
305     static const config_plugin_keys_t cpk[] = {
306       { CONST_STR_LEN("cgi.assign"),
307         T_CONFIG_ARRAY_KVSTRING,
308         T_CONFIG_SCOPE_CONNECTION }
309      ,{ CONST_STR_LEN("cgi.execute-x-only"),
310         T_CONFIG_BOOL,
311         T_CONFIG_SCOPE_CONNECTION }
312      ,{ CONST_STR_LEN("cgi.x-sendfile"),
313         T_CONFIG_BOOL,
314         T_CONFIG_SCOPE_CONNECTION }
315      ,{ CONST_STR_LEN("cgi.x-sendfile-docroot"),
316         T_CONFIG_ARRAY_VLIST,
317         T_CONFIG_SCOPE_CONNECTION }
318      ,{ CONST_STR_LEN("cgi.local-redir"),
319         T_CONFIG_BOOL,
320         T_CONFIG_SCOPE_CONNECTION }
321      ,{ CONST_STR_LEN("cgi.upgrade"),
322         T_CONFIG_BOOL,
323         T_CONFIG_SCOPE_CONNECTION }
324      ,{ CONST_STR_LEN("cgi.limits"),
325         T_CONFIG_ARRAY_KVANY,
326         T_CONFIG_SCOPE_CONNECTION }
327      ,{ NULL, 0,
328         T_CONFIG_UNSET,
329         T_CONFIG_SCOPE_UNSET }
330     };
331 
332     plugin_data * const p = p_d;
333     if (!config_plugin_values_init(srv, p, cpk, "mod_cgi"))
334         return HANDLER_ERROR;
335 
336     /* process and validate config directives
337      * (init i to 0 if global context; to 1 to skip empty global context) */
338     for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
339         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
340         for (; -1 != cpv->k_id; ++cpv) {
341             switch (cpv->k_id) {
342               case 0: /* cgi.assign */
343               case 1: /* cgi.execute-x-only */
344               case 2: /* cgi.x-sendfile */
345                 break;
346               case 3: /* cgi.x-sendfile-docroot */
347                 for (uint32_t j = 0; j < cpv->v.a->used; ++j) {
348                     data_string *ds = (data_string *)cpv->v.a->data[j];
349                     if (ds->value.ptr[0] != '/') {
350                         log_error(srv->errh, __FILE__, __LINE__,
351                           "%s paths must begin with '/'; invalid: \"%s\"",
352                           cpk[cpv->k_id].k, ds->value.ptr);
353                         return HANDLER_ERROR;
354                     }
355                     buffer_path_simplify(&ds->value);
356                     buffer_append_slash(&ds->value);
357                 }
358                 break;
359               case 4: /* cgi.local-redir */
360               case 5: /* cgi.upgrade */
361                 break;
362               case 6: /* cgi.limits */
363                 cpv->v.v = mod_cgi_parse_limits(cpv->v.a, srv->errh);
364                 if (NULL == cpv->v.v) return HANDLER_ERROR;
365                 cpv->vtype = T_CONFIG_LOCAL;
366                 break;
367               default:/* should not happen */
368                 break;
369             }
370         }
371     }
372 
373     /* initialize p->defaults from global config context */
374     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
375         const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
376         if (-1 != cpv->k_id)
377             mod_cgi_merge_config(&p->defaults, cpv);
378     }
379 
380     p->tempfile_accum = config_feature_bool(srv, "cgi.tempfile-accum", 1);
381 
382     return HANDLER_GO_ON;
383 }
384 
385 
386 static cgi_pid_t * cgi_pid_add(plugin_data *p, pid_t pid, handler_ctx *hctx) {
387     cgi_pid_t *cgi_pid = malloc(sizeof(cgi_pid_t));
388     force_assert(cgi_pid);
389     cgi_pid->pid = pid;
390     cgi_pid->signal_sent = 0;
391     cgi_pid->hctx = hctx;
392     cgi_pid->prev = NULL;
393     cgi_pid->next = p->cgi_pid;
394     p->cgi_pid = cgi_pid;
395     return cgi_pid;
396 }
397 
398 static void cgi_pid_kill(cgi_pid_t *cgi_pid, int sig) {
399     cgi_pid->signal_sent = sig; /*(save last signal sent)*/
400     kill(cgi_pid->pid, sig);
401 }
402 
403 static void cgi_pid_del(plugin_data *p, cgi_pid_t *cgi_pid) {
404     if (cgi_pid->prev)
405         cgi_pid->prev->next = cgi_pid->next;
406     else
407         p->cgi_pid = cgi_pid->next;
408 
409     if (cgi_pid->next)
410         cgi_pid->next->prev = cgi_pid->prev;
411 
412     free(cgi_pid);
413 }
414 
415 
416 static void cgi_connection_close_fdtocgi(handler_ctx *hctx) {
417 	/*(closes only hctx->fdtocgi)*/
418 	if (-1 == hctx->fdtocgi) return;
419 	struct fdevents * const ev = hctx->ev;
420 	fdevent_fdnode_event_del(ev, hctx->fdntocgi);
421 	/*fdevent_unregister(ev, hctx->fdtocgi);*//*(handled below)*/
422 	fdevent_sched_close(ev, hctx->fdtocgi, 0);
423 	hctx->fdntocgi = NULL;
424 	hctx->fdtocgi = -1;
425 }
426 
427 static void cgi_connection_close(handler_ctx *hctx) {
428 	/* the connection to the browser went away, but we still have a connection
429 	 * to the CGI script
430 	 *
431 	 * close cgi-connection
432 	 */
433 
434 	if (hctx->fd != -1) {
435 		struct fdevents * const ev = hctx->ev;
436 		/* close connection to the cgi-script */
437 		fdevent_fdnode_event_del(ev, hctx->fdn);
438 		/*fdevent_unregister(ev, hctx->fd);*//*(handled below)*/
439 		fdevent_sched_close(ev, hctx->fd, 0);
440 		hctx->fdn = NULL;
441 	}
442 
443 	if (hctx->fdtocgi != -1) {
444 		cgi_connection_close_fdtocgi(hctx); /*(closes only hctx->fdtocgi)*/
445 	}
446 
447 	plugin_data * const p = hctx->plugin_data;
448 	request_st * const r = hctx->r;
449 	r->plugin_ctx[p->id] = NULL;
450 
451 	if (hctx->cgi_pid) {
452 		cgi_pid_kill(hctx->cgi_pid, SIGTERM);
453 		hctx->cgi_pid->hctx = NULL;
454 	}
455 	cgi_handler_ctx_free(hctx);
456 
457 	/* finish response (if not already r->resp_body_started, r->resp_body_finished) */
458 	if (r->handler_module == p->self) {
459 		http_response_backend_done(r);
460 	}
461 }
462 
463 static handler_t cgi_connection_close_callback(request_st * const r, void *p_d) {
464     handler_ctx *hctx = r->plugin_ctx[((plugin_data *)p_d)->id];
465     if (hctx) {
466         chunkqueue_set_tempdirs(&r->reqbody_queue, /* reset sz */
467                                 r->reqbody_queue.tempdirs, 0);
468         cgi_connection_close(hctx);
469     }
470     return HANDLER_GO_ON;
471 }
472 
473 
474 static int cgi_write_request(handler_ctx *hctx, int fd);
475 
476 
477 static handler_t cgi_handle_fdevent_send (void *ctx, int revents) {
478 	handler_ctx *hctx = ctx;
479 	hctx->wr_revents |= revents;
480 	joblist_append(hctx->con);
481 	return HANDLER_FINISHED;
482 }
483 
484 
485 static handler_t cgi_process_wr_revents (handler_ctx * const hctx, request_st * const r, int revents) {
486 	if (revents & FDEVENT_OUT) {
487 		if (0 != cgi_write_request(hctx, hctx->fdtocgi)) {
488 			cgi_connection_close(hctx);
489 			return HANDLER_ERROR;
490 		}
491 		/* more request body to be sent to CGI */
492 	}
493 
494 	if (revents & FDEVENT_HUP) {
495 		/* skip sending remaining data to CGI */
496 		if (r->reqbody_length) {
497 			chunkqueue *cq = &r->reqbody_queue;
498 			chunkqueue_mark_written(cq, chunkqueue_length(cq));
499 			if (cq->bytes_in != (off_t)r->reqbody_length) {
500 				r->keep_alive = 0;
501 			}
502 		}
503 
504 		cgi_connection_close_fdtocgi(hctx); /*(closes only hctx->fdtocgi)*/
505 	} else if (revents & FDEVENT_ERR) {
506 		/* kill all connections to the cgi process */
507 #if 1
508 		log_error(r->conf.errh, __FILE__, __LINE__, "cgi-FDEVENT_ERR");
509 #endif
510 		cgi_connection_close(hctx);
511 		return HANDLER_ERROR;
512 	}
513 
514 	return HANDLER_GO_ON;
515 }
516 
517 
518 static handler_t cgi_response_headers(request_st * const r, struct http_response_opts_t *opts) {
519     /* response headers just completed */
520     handler_ctx *hctx = (handler_ctx *)opts->pdata;
521 
522     if (light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)) {
523         if (hctx->conf.upgrade && r->http_status == 101) {
524             /* 101 Switching Protocols; transition to transparent proxy */
525             http_response_upgrade_read_body_unknown(r);
526         }
527         else {
528             light_bclr(r->resp_htags, HTTP_HEADER_UPGRADE);
529           #if 0
530             /* preserve prior questionable behavior; likely broken behavior
531              * anyway if backend thinks connection is being upgraded but client
532              * does not receive Connection: upgrade */
533             http_header_response_unset(r, HTTP_HEADER_UPGRADE,
534                                        CONST_STR_LEN("Upgrade"));
535           #endif
536         }
537     }
538 
539     if (hctx->conf.upgrade
540         && !light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)) {
541         chunkqueue *cq = &r->reqbody_queue;
542         hctx->conf.upgrade = 0;
543         if (cq->bytes_out == (off_t)r->reqbody_length) {
544             cgi_connection_close_fdtocgi(hctx); /*(closes hctx->fdtocgi)*/
545         }
546     }
547 
548     return HANDLER_GO_ON;
549 }
550 
551 
552 __attribute_cold__
553 __attribute_noinline__
554 static handler_t cgi_local_redir(request_st * const r, handler_ctx * const hctx) {
555     buffer_clear(hctx->response);
556     chunk_buffer_yield(hctx->response);
557     http_response_reset(r); /*(includes r->http_status = 0)*/
558     plugins_call_handle_request_reset(r);
559     /*cgi_connection_close(hctx);*//*(already cleaned up and hctx is now invalid)*/
560     return HANDLER_COMEBACK;
561 }
562 
563 
564 static int cgi_recv_response(request_st * const r, handler_ctx * const hctx) {
565 		const off_t bytes_in = r->write_queue.bytes_in;
566 		switch (http_response_read(r, &hctx->opts,
567 					   hctx->response, hctx->fdn)) {
568 		default:
569 			if (r->write_queue.bytes_in > bytes_in)
570 				hctx->read_ts = log_monotonic_secs;
571 			return HANDLER_GO_ON;
572 		case HANDLER_ERROR:
573 			http_response_backend_error(r);
574 			__attribute_fallthrough__
575 		case HANDLER_FINISHED:
576 			cgi_connection_close(hctx);
577 			return HANDLER_FINISHED;
578 		case HANDLER_COMEBACK:
579 			return cgi_local_redir(r, hctx); /* HANDLER_COMEBACK */
580 		}
581 }
582 
583 
584 static handler_t cgi_handle_fdevent(void *ctx, int revents) {
585 	handler_ctx *hctx = ctx;
586 	hctx->rd_revents |= revents;
587 	joblist_append(hctx->con);
588 	return HANDLER_FINISHED;
589 }
590 
591 
592 static handler_t cgi_process_rd_revents(handler_ctx * const hctx, request_st * const r, int revents) {
593 	if (revents & FDEVENT_IN) {
594 		handler_t rc = cgi_recv_response(r, hctx); /*(might invalidate hctx)*/
595 		if (rc != HANDLER_GO_ON) return rc;         /*(unless HANDLER_GO_ON)*/
596 	}
597 
598 	/* perhaps this issue is already handled */
599 	if (revents & (FDEVENT_HUP|FDEVENT_RDHUP)) {
600 		if (r->resp_body_started) {
601 			/* drain any remaining data from kernel pipe buffers
602 			 * even if (r->conf.stream_response_body
603 			 *          & FDEVENT_STREAM_RESPONSE_BUFMIN)
604 			 * since event loop will spin on fd FDEVENT_HUP event
605 			 * until unregistered. */
606 			handler_t rc;
607 			const unsigned short flags = r->conf.stream_response_body;
608 			r->conf.stream_response_body &= ~FDEVENT_STREAM_RESPONSE_BUFMIN;
609 			r->conf.stream_response_body |= FDEVENT_STREAM_RESPONSE_POLLRDHUP;
610 			do {
611 				rc = cgi_recv_response(r,hctx); /*(might invalidate hctx)*/
612 			} while (rc == HANDLER_GO_ON);           /*(unless HANDLER_GO_ON)*/
613 			r->conf.stream_response_body = flags;
614 			return rc; /* HANDLER_FINISHED or HANDLER_COMEBACK or HANDLER_ERROR */
615 		} else if (!buffer_is_blank(hctx->response)) {
616 			/* unfinished header package which is a body in reality */
617 			r->resp_body_started = 1;
618 			if (0 != http_chunk_append_buffer(r, hctx->response)) {
619 				cgi_connection_close(hctx);
620 				return HANDLER_ERROR;
621 			}
622 			if (0 == r->http_status) r->http_status = 200; /* OK */
623 		}
624 		cgi_connection_close(hctx);
625 	} else if (revents & FDEVENT_ERR) {
626 		/* kill all connections to the cgi process */
627 		cgi_connection_close(hctx);
628 		return HANDLER_ERROR;
629 	}
630 
631 	return HANDLER_GO_ON;
632 }
633 
634 
635 __attribute_cold__
636 __attribute_noinline__
637 static void cgi_env_offset_resize(env_accum *env) {
638     chunk_buffer_prepare_append(env->boffsets, env->boffsets->size*2);
639     env->offsets = (uintptr_t *)(void *)env->boffsets->ptr;
640     env->osize = env->boffsets->size/sizeof(*env->offsets);
641 }
642 
643 static int cgi_env_add(void *venv, const char *key, size_t key_len, const char *val, size_t val_len) {
644 	env_accum *env = venv;
645 
646 	if (!key || (!val && val_len)) return -1;
647 
648 	if (__builtin_expect( (env->osize == env->oused), 0))
649 		cgi_env_offset_resize(env);
650 	env->offsets[env->oused++] = env->b->used-1;
651 
652 	char * const dst = buffer_extend(env->b, key_len + val_len + 2);
653 	memcpy(dst, key, key_len);
654 	dst[key_len] = '=';
655 	if (val_len) memcpy(dst + key_len + 1, val, val_len);
656 	dst[key_len + 1 + val_len] = '\0';
657 
658 	return 0;
659 }
660 
661 static int cgi_write_request(handler_ctx *hctx, int fd) {
662 	request_st * const r = hctx->r;
663 	chunkqueue *cq = &r->reqbody_queue;
664 	chunk *c;
665 
666 	chunkqueue_remove_finished_chunks(cq); /* unnecessary? */
667 
668 	/* old comment: windows doesn't support select() on pipes - wouldn't be easy to fix for all platforms.
669 	 */
670 
671 	for (c = cq->first; c; c = cq->first) {
672 		ssize_t wr = chunkqueue_write_chunk_to_pipe(fd, cq, r->conf.errh);
673 		if (wr > 0) {
674 			hctx->write_ts = log_monotonic_secs;
675 			chunkqueue_mark_written(cq, wr);
676 			/* continue if wrote whole chunk or wrote 16k block
677 			 * (see chunkqueue_write_chunk_file_intermed()) */
678 			if (c != cq->first || wr == 16384)
679 				continue;
680 			/*(else partial write)*/
681 		}
682 		else if (wr < 0) {
683 				switch(errno) {
684 				case EAGAIN:
685 				case EINTR:
686 					/* ignore and try again later */
687 					break;
688 				case EPIPE:
689 				case ECONNRESET:
690 					/* connection closed */
691 					log_error(r->conf.errh, __FILE__, __LINE__,
692 					  "failed to send post data to cgi, connection closed by CGI");
693 					/* skip all remaining data */
694 					chunkqueue_mark_written(cq, chunkqueue_length(cq));
695 					break;
696 				default:
697 					/* fatal error */
698 					log_perror(r->conf.errh, __FILE__, __LINE__, "write() failed");
699 					return -1;
700 				}
701 		}
702 		/*if (0 == wr) break;*/ /*(might block)*/
703 		break;
704 	}
705 
706 	if (cq->bytes_out == (off_t)r->reqbody_length && !hctx->conf.upgrade) {
707 		/* sent all request body input */
708 		/* close connection to the cgi-script */
709 		if (-1 == hctx->fdtocgi) { /*(received request body sent in initial send to pipe buffer)*/
710 			--r->con->srv->cur_fds;
711 			if (close(fd)) {
712 				log_perror(r->conf.errh, __FILE__, __LINE__, "cgi stdin close %d failed", fd);
713 			}
714 		} else {
715 			cgi_connection_close_fdtocgi(hctx); /*(closes only hctx->fdtocgi)*/
716 		}
717 	} else {
718 		off_t cqlen = chunkqueue_length(cq);
719 		if (cq->bytes_in != r->reqbody_length && cqlen < 65536 - 16384) {
720 			/*(r->conf.stream_request_body & FDEVENT_STREAM_REQUEST)*/
721 			if (!(r->conf.stream_request_body & FDEVENT_STREAM_REQUEST_POLLIN)) {
722 				r->conf.stream_request_body |= FDEVENT_STREAM_REQUEST_POLLIN;
723 				r->con->is_readable = 1; /* trigger optimistic read from client */
724 			}
725 		}
726 		struct fdevents * const ev = hctx->ev;
727 		if (-1 == hctx->fdtocgi) { /*(not registered yet)*/
728 			hctx->fdtocgi = fd;
729 			hctx->fdntocgi = fdevent_register(ev, hctx->fdtocgi, cgi_handle_fdevent_send, hctx);
730 		}
731 		if (0 == cqlen) { /*(chunkqueue_is_empty(cq))*/
732 			if ((fdevent_fdnode_interest(hctx->fdntocgi) & FDEVENT_OUT)) {
733 				fdevent_fdnode_event_set(ev, hctx->fdntocgi, 0);
734 			}
735 		} else {
736 			/* more request body remains to be sent to CGI so register for fdevents */
737 			hctx->write_ts = log_monotonic_secs;
738 			fdevent_fdnode_event_set(ev, hctx->fdntocgi, FDEVENT_OUT);
739 		}
740 	}
741 
742 	return 0;
743 }
744 
745 static int cgi_create_env(request_st * const r, plugin_data * const p, handler_ctx * const hctx, buffer * const cgi_handler) {
746 	char *args[3];
747 	int to_cgi_fds[2];
748 	int from_cgi_fds[2];
749 	UNUSED(p);
750 
751 	if (!buffer_is_blank(cgi_handler)) {
752 		if (NULL == stat_cache_path_stat(cgi_handler)) {
753 			log_perror(r->conf.errh, __FILE__, __LINE__,
754 			  "stat for cgi-handler %s", cgi_handler->ptr);
755 			return -1;
756 		}
757 	}
758 
759 	to_cgi_fds[0] = -1;
760   #ifndef __CYGWIN__
761 	if (0 == r->reqbody_length) {
762 		/* future: might keep fd open in p->devnull for reuse
763 		 * and dup() here, or do not close() (later in this func) */
764 		to_cgi_fds[0] = fdevent_open_devnull();
765 		if (-1 == to_cgi_fds[0]) {
766 			log_perror(r->conf.errh, __FILE__, __LINE__, "open /dev/null");
767 			return -1;
768 		}
769 	}
770 	else if (!(r->conf.stream_request_body /*(if not streaming request body)*/
771 	           & (FDEVENT_STREAM_REQUEST|FDEVENT_STREAM_REQUEST_BUFMIN))) {
772 		chunkqueue * const cq = &r->reqbody_queue;
773 		chunk * const c = cq->first;
774 		if (c && c == cq->last && c->type == FILE_CHUNK && c->file.is_temp) {
775 			/* request body in single tempfile if not streaming req body */
776 			if (-1 == c->file.fd
777 			    && 0 != chunkqueue_open_file_chunk(cq, r->conf.errh))
778 				return -1;
779 		  #ifdef __COVERITY__
780 			force_assert(-1 != c->file.fd);
781 		  #endif
782 			if (-1 == lseek(c->file.fd, 0, SEEK_SET)) {
783 				log_perror(r->conf.errh, __FILE__, __LINE__,
784 				  "lseek %s", c->mem->ptr);
785 				return -1;
786 			}
787 			to_cgi_fds[0] = c->file.fd;
788 			to_cgi_fds[1] = -1;
789 		}
790 	}
791   #endif
792 
793 	unsigned int bufsz_hint = 16384;
794   #ifdef _WIN32
795 	if (r->reqbody_length <= 1048576)
796 		bufsz_hint = (unsigned int)r->reqbody_length;
797   #endif
798 	if (-1 == to_cgi_fds[0] && fdevent_pipe_cloexec(to_cgi_fds, bufsz_hint)) {
799 		log_perror(r->conf.errh, __FILE__, __LINE__, "pipe failed");
800 		return -1;
801 	}
802 	if (fdevent_pipe_cloexec(from_cgi_fds, bufsz_hint)) {
803 		if (0 == r->reqbody_length) {
804 			close(to_cgi_fds[0]);
805 		}
806 		else if (-1 != to_cgi_fds[1]) {
807 			close(to_cgi_fds[0]);
808 			close(to_cgi_fds[1]);
809 		}
810 		log_perror(r->conf.errh, __FILE__, __LINE__, "pipe failed");
811 		return -1;
812 	}
813 
814 	env_accum * const env = &p->env;
815 	env->b = chunk_buffer_acquire();
816 	env->boffsets = chunk_buffer_acquire();
817 	buffer_truncate(env->b, 0);
818 	char **envp;
819 	{
820 		size_t i = 0;
821 		http_cgi_opts opts = { 0, 0, NULL, NULL };
822 		env->offsets = (uintptr_t *)(void *)env->boffsets->ptr;
823 		env->osize = env->boffsets->size/sizeof(*env->offsets);
824 		env->oused = 0;
825 
826 		/* create environment */
827 
828 		http_cgi_headers(r, &opts, cgi_env_add, env);
829 
830 		/* for valgrind */
831 		if (p->env.ld_preload) {
832 			cgi_env_add(env, CONST_STR_LEN("LD_PRELOAD"), BUF_PTR_LEN(p->env.ld_preload));
833 		}
834 		if (p->env.ld_library_path) {
835 			cgi_env_add(env, CONST_STR_LEN("LD_LIBRARY_PATH"), BUF_PTR_LEN(p->env.ld_library_path));
836 		}
837 	      #ifdef __CYGWIN__
838 		/* CYGWIN needs SYSTEMROOT */
839 		if (p->env.systemroot) {
840 			cgi_env_add(env, CONST_STR_LEN("SYSTEMROOT"), BUF_PTR_LEN(p->env.systemroot));
841 		}
842 	      #endif
843 
844 		/* adjust (uintptr_t) offsets to (char *) ptr
845 		 * (stored as offsets while accumulating in buffer,
846 		 *  in case buffer is reallocated during env creation) */
847 		if (__builtin_expect( (env->osize == env->oused), 0))
848 			cgi_env_offset_resize(env);
849 		envp = (char **)env->offsets;
850 		envp[env->oused] = NULL;
851 		const uintptr_t baseptr = (uintptr_t)env->b->ptr;
852 		for (i = 0; i < env->oused; ++i)
853 			envp[i] += baseptr;
854 
855 		/* set up args */
856 		i = 0;
857 
858 		if (!buffer_is_blank(cgi_handler)) {
859 			args[i++] = cgi_handler->ptr;
860 		}
861 		args[i++] = r->physical.path.ptr;
862 		args[i  ] = NULL;
863 	}
864 
865 	int dfd = fdevent_open_dirname(r->physical.path.ptr,r->conf.follow_symlink);
866 	if (-1 == dfd) {
867 		log_perror(r->conf.errh, __FILE__, __LINE__, "open dirname %s failed", r->physical.path.ptr);
868 	}
869 
870 	int serrh_fd = r->conf.serrh ? r->conf.serrh->fd : -1;
871 	pid_t pid = (dfd >= 0)
872 	  ? fdevent_fork_execve(args[0], args, envp,
873 	                        to_cgi_fds[0], from_cgi_fds[1], serrh_fd, dfd)
874 	  : -1;
875 
876 	chunk_buffer_release(env->boffsets);
877 	chunk_buffer_release(env->b);
878 	env->boffsets = NULL;
879 	env->b = NULL;
880 
881 	if (-1 == pid) {
882 		/* log error with errno prior to calling close() (might change errno) */
883 		log_perror(r->conf.errh, __FILE__, __LINE__, "fork failed");
884 		if (-1 != dfd) close(dfd);
885 		close(from_cgi_fds[0]);
886 		close(from_cgi_fds[1]);
887 		if (0 == r->reqbody_length) {
888 			close(to_cgi_fds[0]);
889 		}
890 		else if (-1 != to_cgi_fds[1]) {
891 			close(to_cgi_fds[0]);
892 			close(to_cgi_fds[1]);
893 		}
894 		return -1;
895 	} else {
896 		if (-1 != dfd) close(dfd);
897 		close(from_cgi_fds[1]);
898 
899 		hctx->fd = from_cgi_fds[0];
900 		hctx->cgi_pid = cgi_pid_add(p, pid, hctx);
901 
902 		if (0 == r->reqbody_length) {
903 			close(to_cgi_fds[0]);
904 		}
905 		else if (-1 == to_cgi_fds[1]) {
906 			chunkqueue * const cq = &r->reqbody_queue;
907 			chunkqueue_mark_written(cq, chunkqueue_length(cq));
908 		}
909 		else if (0 == fdevent_fcntl_set_nb(to_cgi_fds[1])
910 		         && 0 == cgi_write_request(hctx, to_cgi_fds[1])) {
911 			close(to_cgi_fds[0]);
912 			++r->con->srv->cur_fds;
913 		}
914 		else {
915 			close(to_cgi_fds[0]);
916 			close(to_cgi_fds[1]);
917 			/*(hctx->fd not yet registered with fdevent, so manually
918 			 * cleanup here; see fdevent_register() further below)*/
919 			close(hctx->fd);
920 			hctx->fd = -1;
921 			cgi_connection_close(hctx);
922 			return -1;
923 		}
924 
925 		++r->con->srv->cur_fds;
926 
927 		struct fdevents * const ev = hctx->ev;
928 		hctx->fdn = fdevent_register(ev, hctx->fd, cgi_handle_fdevent, hctx);
929 		if (-1 == fdevent_fcntl_set_nb(hctx->fd)) {
930 			log_perror(r->conf.errh, __FILE__, __LINE__, "fcntl failed");
931 			cgi_connection_close(hctx);
932 			return -1;
933 		}
934 		hctx->read_ts = log_monotonic_secs;
935 		fdevent_fdnode_event_set(ev, hctx->fdn, FDEVENT_IN | FDEVENT_RDHUP);
936 
937 		return 0;
938 	}
939 }
940 
941 URIHANDLER_FUNC(cgi_is_handled) {
942 	plugin_data *p = p_d;
943 	const stat_cache_st *st;
944 	data_string *ds;
945 
946 	if (NULL != r->handler_module) return HANDLER_GO_ON;
947 	/* r->physical.path is non-empty for handle_subrequest_start */
948 	/*if (buffer_is_blank(&r->physical.path)) return HANDLER_GO_ON;*/
949 
950 	mod_cgi_patch_config(r, p);
951 	if (NULL == p->conf.cgi) return HANDLER_GO_ON;
952 
953 	ds = (data_string *)array_match_key_suffix(p->conf.cgi, &r->physical.path);
954 	if (NULL == ds) return HANDLER_GO_ON;
955 
956 	/* r->tmp_sce is set in http_response_physical_path_check() and is valid
957 	 * in handle_subrequest_start callback -- handle_subrequest_start callbacks
958 	 * should not change r->physical.path (or should invalidate r->tmp_sce) */
959 	st = r->tmp_sce && buffer_is_equal(&r->tmp_sce->name, &r->physical.path)
960 	   ? &r->tmp_sce->st
961 	   : stat_cache_path_stat(&r->physical.path);
962 	if (NULL == st) return HANDLER_GO_ON;
963 
964 	/* (aside: CGI might be executable even if it is not readable) */
965 	if (!S_ISREG(st->st_mode)) return HANDLER_GO_ON;
966 	if (p->conf.execute_x_only == 1 && (st->st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) return HANDLER_GO_ON;
967 
968 	if (r->reqbody_length
969 	    && p->tempfile_accum
970 	    && !(r->conf.stream_request_body /*(if not streaming request body)*/
971 	         & (FDEVENT_STREAM_REQUEST|FDEVENT_STREAM_REQUEST_BUFMIN))) {
972 		/* store request body in single tempfile if not streaming request body*/
973 		r->reqbody_queue.upload_temp_file_size = INTMAX_MAX;
974 	}
975 
976 	{
977 		handler_ctx *hctx = cgi_handler_ctx_init();
978 		hctx->ev = r->con->srv->ev;
979 		hctx->r = r;
980 		hctx->con = r->con;
981 		hctx->plugin_data = p;
982 		hctx->cgi_handler = &ds->value;
983 		memcpy(&hctx->conf, &p->conf, sizeof(plugin_config));
984 		if (!light_btst(r->rqst_htags, HTTP_HEADER_UPGRADE))
985 			hctx->conf.upgrade = 0;
986 		else if (!hctx->conf.upgrade || r->http_version != HTTP_VERSION_1_1) {
987 			hctx->conf.upgrade = 0;
988 			http_header_request_unset(r, HTTP_HEADER_UPGRADE,
989 			                          CONST_STR_LEN("Upgrade"));
990 		}
991 		hctx->opts.max_per_read =
992 		  !(r->conf.stream_response_body /*(if not streaming response body)*/
993 		    & (FDEVENT_STREAM_RESPONSE|FDEVENT_STREAM_RESPONSE_BUFMIN))
994 		    ? 262144
995 		    : (r->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
996 		      ? 16384  /* FDEVENT_STREAM_RESPONSE_BUFMIN */
997 		      : 65536; /* FDEVENT_STREAM_RESPONSE */
998 		hctx->opts.fdfmt = S_IFIFO;
999 		hctx->opts.backend = BACKEND_CGI;
1000 		hctx->opts.authorizer = 0;
1001 		hctx->opts.local_redir = hctx->conf.local_redir;
1002 		hctx->opts.xsendfile_allow = hctx->conf.xsendfile_allow;
1003 		hctx->opts.xsendfile_docroot = hctx->conf.xsendfile_docroot;
1004 		hctx->opts.pdata = hctx;
1005 		hctx->opts.headers = cgi_response_headers;
1006 		r->plugin_ctx[p->id] = hctx;
1007 		r->handler_module = p->self;
1008 	}
1009 
1010 	return HANDLER_GO_ON;
1011 }
1012 
1013 /*
1014  * - HANDLER_GO_ON : not our job
1015  * - HANDLER_FINISHED: got response
1016  * - HANDLER_WAIT_FOR_EVENT: waiting for response
1017  */
1018 SUBREQUEST_FUNC(mod_cgi_handle_subrequest) {
1019 	plugin_data * const p = p_d;
1020 	handler_ctx * const hctx = r->plugin_ctx[p->id];
1021 	if (NULL == hctx) return HANDLER_GO_ON;
1022 
1023 	if (__builtin_expect(
1024 	     (r->conf.stream_request_body & FDEVENT_STREAM_REQUEST_TCP_FIN), 0)
1025 	    && hctx->conf.limits && hctx->conf.limits->signal_fin) {
1026 		/* XXX: consider setting r->http_status = 499 if (0 == r->http_status)
1027 		 * (499 is nginx custom status to indicate client closed connection) */
1028 		if (-1 == hctx->fd) return HANDLER_ERROR; /*(CGI not yet spawned)*/
1029 		if (hctx->cgi_pid) /* send signal to notify CGI about TCP FIN */
1030 			cgi_pid_kill(hctx->cgi_pid, hctx->conf.limits->signal_fin);
1031 	}
1032 
1033 	const int rd_revents = hctx->rd_revents;
1034 	const int wr_revents = hctx->wr_revents;
1035 	if (rd_revents) {
1036 		hctx->rd_revents = 0;
1037 		handler_t rc = cgi_process_rd_revents(hctx, r, rd_revents);
1038 		if (rc != HANDLER_GO_ON) return rc; /*(might invalidate hctx)*/
1039 	}
1040 	if (wr_revents) {
1041 		hctx->wr_revents = 0;
1042 		handler_t rc = cgi_process_wr_revents(hctx, r, wr_revents);
1043 		if (rc != HANDLER_GO_ON) return rc; /*(might invalidate hctx)*/
1044 	}
1045 
1046 	if ((r->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
1047 	    && r->resp_body_started) {
1048 		if (chunkqueue_length(&r->write_queue) > 65536 - 4096) {
1049 			fdevent_fdnode_event_clr(hctx->ev, hctx->fdn, FDEVENT_IN);
1050 		} else if (!(fdevent_fdnode_interest(hctx->fdn) & FDEVENT_IN)) {
1051 			/* optimistic read from backend */
1052 			handler_t rc = cgi_recv_response(r, hctx);  /*(might invalidate hctx)*/
1053 			if (rc != HANDLER_GO_ON) return rc;          /*(unless HANDLER_GO_ON)*/
1054 			hctx->read_ts = log_monotonic_secs;
1055 			fdevent_fdnode_event_add(hctx->ev, hctx->fdn, FDEVENT_IN);
1056 		}
1057 	}
1058 
1059 	chunkqueue * const cq = &r->reqbody_queue;
1060 
1061 	if (cq->bytes_in != (off_t)r->reqbody_length) {
1062 		/*(64k - 4k to attempt to avoid temporary files
1063 		 * in conjunction with FDEVENT_STREAM_REQUEST_BUFMIN)*/
1064 		if (chunkqueue_length(cq) > 65536 - 4096
1065 		    && (r->conf.stream_request_body & FDEVENT_STREAM_REQUEST_BUFMIN)){
1066 			r->conf.stream_request_body &= ~FDEVENT_STREAM_REQUEST_POLLIN;
1067 			if (-1 != hctx->fd) return HANDLER_WAIT_FOR_EVENT;
1068 		} else {
1069 			handler_t rc = r->con->reqbody_read(r);
1070 			if (!chunkqueue_is_empty(cq)) {
1071 				if (fdevent_fdnode_interest(hctx->fdntocgi) & FDEVENT_OUT) {
1072 					return (rc == HANDLER_GO_ON) ? HANDLER_WAIT_FOR_EVENT : rc;
1073 				}
1074 			}
1075 			if (rc != HANDLER_GO_ON) return rc;
1076 
1077 			/* CGI environment requires that Content-Length be set.
1078 			 * Send 411 Length Required if Content-Length missing.
1079 			 * (occurs here if client sends Transfer-Encoding: chunked
1080 			 *  and module is flagged to stream request body to backend) */
1081 			if (-1 == r->reqbody_length) {
1082 				return (r->conf.stream_request_body & FDEVENT_STREAM_REQUEST)
1083 				  ? http_response_reqbody_read_error(r, 411)
1084 				  : HANDLER_WAIT_FOR_EVENT;
1085 			}
1086 		}
1087 	}
1088 
1089 	if (-1 == hctx->fd) {
1090 		if (cgi_create_env(r, p, hctx, hctx->cgi_handler)) {
1091 			r->http_status = 500;
1092 			r->handler_module = NULL;
1093 
1094 			return HANDLER_FINISHED;
1095 		}
1096 	} else if (!chunkqueue_is_empty(cq)) {
1097 		if (0 != cgi_write_request(hctx, hctx->fdtocgi)) {
1098 			cgi_connection_close(hctx);
1099 			return HANDLER_ERROR;
1100 		}
1101 	}
1102 
1103 	/* if not done, wait for CGI to close stdout, so we read EOF on pipe */
1104 	return HANDLER_WAIT_FOR_EVENT;
1105 }
1106 
1107 
1108 __attribute_cold__
1109 __attribute_noinline__
1110 static void cgi_trigger_hctx_timeout(handler_ctx * const hctx, const char * const msg) {
1111     request_st * const r = hctx->r;
1112     joblist_append(r->con);
1113 
1114     log_error(r->conf.errh, __FILE__, __LINE__,
1115       "%s timeout on CGI: %s (pid: %lld)",
1116       msg, r->physical.path.ptr, (long long)hctx->cgi_pid->pid);
1117 
1118     if (*msg == 'w') { /* "write" */
1119         /* theoretically, response might be waiting on hctx->fdn pipe
1120          * if it arrived since we last checked for event, and if CGI
1121          * timeout out while reading (or did not read) request body */
1122         handler_t rc = cgi_recv_response(r, hctx); /*(might invalidate hctx)*/
1123         if (rc != HANDLER_GO_ON) return;            /*(unless HANDLER_GO_ON)*/
1124     }
1125 
1126     if (0 == r->http_status) r->http_status = 504; /* Gateway Timeout */
1127     cgi_connection_close(hctx);
1128 }
1129 
1130 
1131 static handler_t cgi_trigger_cb(server *srv, void *p_d) {
1132     UNUSED(srv);
1133     const unix_time64_t mono = log_monotonic_secs;
1134     plugin_data * const p = p_d;
1135     for (cgi_pid_t *cgi_pid = p->cgi_pid; cgi_pid; cgi_pid = cgi_pid->next) {
1136         /*(hctx stays in cgi_pid list until process pid is reaped,
1137          * so p->cgi_pid[] is not modified during this loop)*/
1138         handler_ctx * const hctx = cgi_pid->hctx;
1139         if (!hctx) continue; /*(already called cgi_pid_kill())*/
1140         const cgi_limits * const limits = hctx->conf.limits;
1141         if (NULL == limits) continue;
1142         if (limits->read_timeout && hctx->fdn
1143             && (fdevent_fdnode_interest(hctx->fdn) & FDEVENT_IN)
1144             && mono - hctx->read_ts > limits->read_timeout) {
1145             cgi_trigger_hctx_timeout(hctx, "read");
1146             continue;
1147         }
1148         if (limits->write_timeout && hctx->fdntocgi
1149             && (fdevent_fdnode_interest(hctx->fdntocgi) & FDEVENT_OUT)
1150             && mono - hctx->write_ts > limits->write_timeout) {
1151             cgi_trigger_hctx_timeout(hctx, "write");
1152             continue;
1153         }
1154     }
1155     return HANDLER_GO_ON;
1156 }
1157 
1158 
1159 static handler_t cgi_waitpid_cb(server *srv, void *p_d, pid_t pid, int status) {
1160     /*(XXX: if supporting a large number of CGI, might use a different algorithm
1161      * instead of linked list, e.g. splaytree indexed with pid)*/
1162     plugin_data *p = (plugin_data *)p_d;
1163     for (cgi_pid_t *cgi_pid = p->cgi_pid; cgi_pid; cgi_pid = cgi_pid->next) {
1164         if (pid != cgi_pid->pid) continue;
1165 
1166         handler_ctx * const hctx = cgi_pid->hctx;
1167         if (hctx) hctx->cgi_pid = NULL;
1168 
1169         if (WIFEXITED(status)) {
1170             /* (skip logging (non-zero) CGI exit; might be very noisy) */
1171         }
1172         else if (WIFSIGNALED(status)) {
1173             /* ignore SIGTERM if sent by cgi_connection_close() (NULL == hctx)*/
1174             if (WTERMSIG(status) != cgi_pid->signal_sent) {
1175                 log_error_st *errh = hctx ? hctx->r->conf.errh : srv->errh;
1176                 log_error(errh, __FILE__, __LINE__,
1177                   "CGI pid %d died with signal %d", pid, WTERMSIG(status));
1178             }
1179         }
1180         else {
1181             log_error_st *errh = hctx ? hctx->r->conf.errh : srv->errh;
1182             log_error(errh, __FILE__, __LINE__,
1183               "CGI pid %d ended unexpectedly", pid);
1184         }
1185 
1186         cgi_pid_del(p, cgi_pid);
1187         return HANDLER_FINISHED;
1188     }
1189 
1190     return HANDLER_GO_ON;
1191 }
1192 
1193 
1194 int mod_cgi_plugin_init(plugin *p);
1195 int mod_cgi_plugin_init(plugin *p) {
1196 	p->version     = LIGHTTPD_VERSION_ID;
1197 	p->name        = "cgi";
1198 
1199 	p->handle_request_reset = cgi_connection_close_callback;
1200 	p->handle_subrequest_start = cgi_is_handled;
1201 	p->handle_subrequest = mod_cgi_handle_subrequest;
1202 	p->handle_trigger = cgi_trigger_cb;
1203 	p->handle_waitpid = cgi_waitpid_cb;
1204 	p->init           = mod_cgi_init;
1205 	p->cleanup        = mod_cgi_free;
1206 	p->set_defaults   = mod_cgi_set_defaults;
1207 
1208 	return 0;
1209 }
1210