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Date:: Tue Sep 13 21:28:51 2022 UTC
Message:: drop useless proxy_accept wrapper just call fcgi_accept (with args tweaked)
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1 /*
2  * Copyright (c) 2022 Omar Polo <op@omarpolo.com>
3  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/socket.h>
22 #include <sys/uio.h>
23 
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26 #include <netdb.h>
27 
28 #include <asr.h>
29 #include <ctype.h>
30 #include <errno.h>
31 #include <event.h>
32 #include <limits.h>
33 #include <stdlib.h>
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <imsg.h>
38 #include <tls.h>
39 #include <unistd.h>
40 
41 #include "log.h"
42 #include "proc.h"
43 
44 #include "galileo.h"
45 
46 #define MINIMUM(a, b)	((a) < (b) ? (a) : (b))
47 
48 /* provided by OpenBSD' base libevent but not in any header? */
49 extern void	 bufferevent_read_pressure_cb(struct evbuffer *, size_t,
50 		    size_t, void *);
51 
52 void	proxy_init(struct privsep *, struct privsep_proc *, void *);
53 int	proxy_launch(struct galileo *);
54 void	proxy_inflight_dec(const char *);
55 int	proxy_dispatch_parent(int, struct privsep_proc *, struct imsg *);
56 void	proxy_resolved(struct asr_result *, void *);
57 void	proxy_connect(int, short, void *);
58 void	proxy_read(struct bufferevent *, void *);
59 void	proxy_write(struct bufferevent *, void *);
60 void	proxy_error(struct bufferevent *, short, void *);
61 int	proxy_bufferevent_add(struct event *, int);
62 void	proxy_tls_writecb(int, short, void *);
63 void	proxy_tls_readcb(int, short, void *);
64 
65 static struct privsep_proc procs[] = {
66 	{ "parent",	PROC_PARENT, proxy_dispatch_parent },
67 };
68 
69 volatile int proxy_clients;
70 volatile int proxy_inflight;
71 uint32_t proxy_fcg_id;
72 
73 void
74 proxy(struct privsep *ps, struct privsep_proc *p)
75 {
76 	proc_run(ps, p, procs, nitems(procs), proxy_init, NULL);
77 }
78 
79 void
80 proxy_init(struct privsep *ps, struct privsep_proc *p, void *arg)
81 {
82 	if (config_init(ps->ps_env) == -1)
83 		fatal("failed to initialize configuration");
84 
85 	/* We use a custom shutdown callback */
86 	/* p->p_shutdown = proxy_shutdown */
87 
88 	if (pledge("stdio recvfd unix inet dns", NULL) == -1)
89 		fatal("pledge");
90 }
91 
92 int
93 proxy_launch(struct galileo *env)
94 {
95 	event_add(&env->sc_evsock, NULL);
96 	return (0);
97 }
98 
99 void
100 proxy_purge(struct server *srv)
101 {
102 }
103 
104 void
105 proxy_inflight_dec(const char *why)
106 {
107 	proxy_inflight--;
108 	log_debug("%s: inflight decremented, now %d, %s",
109 	    __func__, proxy_inflight, why);
110 }
111 
112 int
113 proxy_dispatch_parent(int fd, struct privsep_proc *p, struct imsg *imsg)
114 {
115 	struct privsep	*ps = p->p_ps;
116 	struct galileo	*env = ps->ps_env;
117 
118 	switch (imsg->hdr.type) {
119 	case IMSG_CFG_SRV:
120 		if (config_getserver(env, imsg) == -1)
121 			fatal("config_getproxy");
122 		break;
123 	case IMSG_CFG_SOCK:
124 		/* XXX: improve */
125 
126 		if (env->sc_sock_fd != -1) {
127 			event_del(&env->sc_evsock);
128 			close(env->sc_sock_fd);
129 		}
130 
131 		env->sc_sock_fd = config_getsock(env, imsg);
132 		if (env->sc_sock_fd == -1)
133 			fatal("config_getsock");
134 
135 		event_set(&env->sc_evsock, env->sc_sock_fd,
136 		    EV_READ | EV_PERSIST, fcgi_accept, env);
137 		event_add(&env->sc_evsock, NULL);
138 		evtimer_set(&env->sc_evpause, fcgi_accept, env);
139 		break;
140 	case IMSG_CFG_DONE:
141 		log_debug("config done!");
142 		break;
143 	case IMSG_CTL_START:
144 		proxy_launch(env);
145 		break;
146 	default:
147 		log_warnx("unknown message %d", imsg->hdr.type);
148 		return (-1);
149 	}
150 
151 	return (0);
152 }
153 
154 static struct proxy_config *
155 proxy_server_match(struct galileo *env, struct client *clt)
156 {
157 	struct server		*srv;
158 
159 	if (clt->clt_server_name == NULL)
160 		return NULL;
161 
162 	TAILQ_FOREACH(srv, &env->sc_servers, srv_entry) {
163 		if (!strcmp(clt->clt_server_name, srv->srv_conf.host))
164 			return &srv->srv_conf;
165 	}
166 
167 	return NULL;
168 }
169 
170 void
171 proxy_start_request(struct galileo *env, struct client *clt)
172 {
173 	struct addrinfo		 hints;
174 	struct asr_query	*query;
175 	char			 port[32];
176 
177 	if ((clt->clt_pc = proxy_server_match(env, clt)) == NULL) {
178 		if (clt_printf(clt, "Status: 501\r\n\r\n") == -1)
179 			return;
180 		fcgi_end_request(clt, 1);
181 		return;
182 	}
183 
184 	(void)snprintf(port, sizeof(port), "%d", clt->clt_pc->proxy_port);
185 
186 	memset(&hints, 0, sizeof(hints));
187 	hints.ai_family = AF_UNSPEC;
188 	hints.ai_socktype = SOCK_STREAM;
189 
190 	query = getaddrinfo_async(clt->clt_pc->proxy_addr, port, &hints, NULL);
191 	if (query == NULL) {
192 		log_warn("getaddrinfo_async");
193 		fcgi_abort_request(clt);
194 		return;
195 	}
196 
197 	clt->clt_evasr = event_asr_run(query, proxy_resolved, clt);
198 	if (clt->clt_evasr == NULL) {
199 		log_warn("event_asr_run");
200 		asr_abort(query);
201 		fcgi_abort_request(clt);
202 		return;
203 	}
204 }
205 
206 void
207 proxy_resolved(struct asr_result *res, void *d)
208 {
209 	struct client		*clt = d;
210 	struct proxy_config	*pc = clt->clt_pc;
211 
212 	clt->clt_evasr = NULL;
213 
214 	if (res->ar_gai_errno != 0) {
215 		log_warnx("failed to resolve %s:%d: %s",
216 		    pc->proxy_addr, pc->proxy_port,
217 		    gai_strerror(res->ar_gai_errno));
218 		if (clt_printf(clt, "Status: 501\r\n") == -1)
219 			return;
220 		if (clt_printf(clt, "Content-Type: text/plain\r\n") == -1)
221 			return;
222 		if (clt_printf(clt, "Proxy error; connection failed") == -1)
223 			return;
224 		fcgi_end_request(clt, 1);
225 		return;
226 	}
227 
228 	clt->clt_addrinfo = res->ar_addrinfo;
229 	clt->clt_p = clt->clt_addrinfo;
230 	proxy_connect(-1, 0, clt);
231 }
232 
233 void
234 proxy_connect(int fd, short ev, void *d)
235 {
236 	struct client		*clt = d;
237 	struct evbuffer		*out;
238 	struct addrinfo		*p;
239 	struct tls_config	*conf;
240 	struct timeval		 conntv = {5, 0};
241 	int			 err = 0;
242 	socklen_t		 len = sizeof(err);
243 
244 again:
245 	if (clt->clt_p == NULL)
246 		goto err;
247 
248 	if (clt->clt_fd != -1) {
249 		if (getsockopt(clt->clt_fd, SOL_SOCKET, SO_ERROR, &err, &len)
250 		    == -1)
251 			goto err;
252 		if (err != 0) {
253 			errno = err;
254 			goto err;
255 		}
256 		goto done;
257 	}
258 
259 	p = clt->clt_p;
260 	clt->clt_fd = socket(p->ai_family, p->ai_socktype | SOCK_NONBLOCK,
261 	    p->ai_protocol);
262 	if (clt->clt_fd == -1) {
263 		clt->clt_p = clt->clt_p->ai_next;
264 		goto again;
265 	}
266 
267 	if (connect(clt->clt_fd, p->ai_addr, p->ai_addrlen) == 0)
268 		goto done;
269 
270 	clt->clt_evconn_live = 1;
271 	event_set(&clt->clt_evconn, clt->clt_fd, EV_WRITE, proxy_connect, clt);
272 	event_add(&clt->clt_evconn, &conntv);
273 	return;
274 
275 done:
276 	clt->clt_evconn_live = 0;
277 	freeaddrinfo(clt->clt_addrinfo);
278 	clt->clt_addrinfo = clt->clt_p = NULL;
279 
280 	/* initialize TLS for Gemini */
281 	if ((conf = tls_config_new()) == NULL) {
282 		log_warn("tls_config_new failed");
283 		goto err;
284 	}
285 
286 	tls_config_insecure_noverifycert(conf);
287 
288 	if ((clt->clt_ctx = tls_client()) == NULL) {
289 		log_warnx("tls_client failed");
290 		tls_config_free(conf);
291 		goto err;
292 	}
293 
294 	if (tls_configure(clt->clt_ctx, conf) == -1) {
295 		log_warnx("tls_configure failed");
296 		tls_config_free(conf);
297 		goto err;
298 	}
299 
300 	tls_config_free(conf);
301 
302 	if (tls_connect_socket(clt->clt_ctx, clt->clt_fd,
303 	    clt->clt_pc->proxy_name) == -1) {
304 		log_warnx("tls_connect_socket failed");
305 		goto err;
306 	}
307 
308 	clt->clt_bev = bufferevent_new(clt->clt_fd, proxy_read, proxy_write,
309 	    proxy_error, clt);
310 	if (clt->clt_bev == NULL) {
311 		log_warn("bufferevent_new");
312 		goto err;
313 	}
314 	out = EVBUFFER_OUTPUT(clt->clt_bev);
315 
316 	event_set(&clt->clt_bev->ev_read, clt->clt_fd, EV_READ,
317 	    proxy_tls_readcb, clt->clt_bev);
318 	event_set(&clt->clt_bev->ev_write, clt->clt_fd, EV_WRITE,
319 	    proxy_tls_writecb, clt->clt_bev);
320 
321 	/* bufferevent_settimeout(); */
322 	bufferevent_enable(clt->clt_bev, EV_READ|EV_WRITE);
323 
324 	/* TODO: compute the URL */
325 	if (evbuffer_add_printf(out, "gemini://localhost/\r\n") == -1) {
326 		log_warn("bufferevent_printf failed");
327 		goto err;
328 	}
329 
330 	return;
331 
332 err:
333 	log_warn("failed to connect to %s:%d",
334 	    clt->clt_pc->proxy_addr, clt->clt_pc->proxy_port);
335 	if (clt_printf(clt, "Status: 501\r\n") == -1)
336 		return;
337 	if (clt_printf(clt, "Content-Type: text/plain\r\n") == -1)
338 		return;
339 	if (clt_printf(clt, "Proxy error; connection failed") == -1)
340 		return;
341 	fcgi_end_request(clt, 1);
342 }
343 
344 void
345 proxy_read(struct bufferevent *bev, void *d)
346 {
347 	struct client		*clt = d;
348 	struct evbuffer		*src = EVBUFFER_INPUT(bev);
349 	char			*hdr;
350 	size_t			 len;
351 	int			 code;
352 
353 	if (clt->clt_headersdone) {
354 	copy:
355 		clt_write_bufferevent(clt, bev);
356 		return;
357 	}
358 
359 	hdr = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
360 	if (hdr == NULL) {
361 		if (EVBUFFER_LENGTH(src) >= 1026)
362 			proxy_error(bev, EV_READ, clt);
363 		return;
364 	}
365 
366 	if (len < 4 ||
367 	    !isdigit((unsigned char)hdr[0]) ||
368 	    !isdigit((unsigned char)hdr[1]) ||
369 	    hdr[2] != ' ') {
370 		log_warnx("invalid ");
371 		free(hdr);
372 		proxy_error(bev, EV_READ, clt);
373 		return;
374 	}
375 
376 	code = (hdr[0] - '0') * 10 + (hdr[1] - '0');
377 	if (code != 20) {
378 		log_warnx("un-handled gemini reply status %d", code);
379 		free(hdr);
380 		proxy_error(bev, EV_READ, clt);
381 		return;
382 	}
383 
384 	if (clt_printf(clt, "Content-Type: %s\r\n", &hdr[4]) == -1)
385 		return;
386 	if (clt_printf(clt, "\r\n") == -1)
387 		return;
388 
389 	clt->clt_headersdone = 1;
390 	goto copy;
391 }
392 
393 void
394 proxy_write(struct bufferevent *bev, void *d)
395 {
396 	return;
397 }
398 
399 void
400 proxy_error(struct bufferevent *bev, short err, void *d)
401 {
402 	struct client		*clt = d;
403 	int			 status = !(err & EVBUFFER_EOF);
404 
405 	log_debug("proxy error, shutting down the connection (err: %x)",
406 	    err);
407 
408 	if (!clt->clt_headersdone) {
409 		if (clt_printf(clt, "Status: 501\r\n") == -1)
410 			return;
411 		if (clt_printf(clt, "Content-Type: text/plain\r\n") == -1)
412 			return;
413 		if (clt_printf(clt, "Proxy error\n") == -1)
414 			return;
415 	}
416 
417 	fcgi_end_request(clt, status);
418 }
419 
420 void
421 proxy_tls_readcb(int fd, short event, void *arg)
422 {
423 	struct bufferevent	*bufev = arg;
424 	struct client		*clt = bufev->cbarg;
425 	char			 rbuf[IBUF_READ_SIZE];
426 	int			 what = EVBUFFER_READ;
427 	int			 howmuch = IBUF_READ_SIZE;
428 	ssize_t			 ret;
429 	size_t			 len;
430 
431 	if (event == EV_TIMEOUT) {
432 		what |= EVBUFFER_TIMEOUT;
433 		goto err;
434 	}
435 
436 	if (bufev->wm_read.high != 0)
437 		howmuch = MINIMUM(sizeof(rbuf), bufev->wm_read.high);
438 
439 	ret = tls_read(clt->clt_ctx, rbuf, howmuch);
440 	if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
441 		goto retry;
442 	} else if (ret == -1) {
443 		what |= EVBUFFER_ERROR;
444 		goto err;
445 	}
446 	len = ret;
447 
448 	if (len == 0) {
449 		what |= EVBUFFER_EOF;
450 		goto err;
451 	}
452 
453 	if (evbuffer_add(bufev->input, rbuf, len) == -1) {
454 		what |= EVBUFFER_ERROR;
455 		goto err;
456 	}
457 
458 	proxy_bufferevent_add(&bufev->ev_read, bufev->timeout_read);
459 
460 	len = EVBUFFER_LENGTH(bufev->input);
461 	if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
462 		return;
463 	if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
464 		struct evbuffer *buf = bufev->input;
465 		event_del(&bufev->ev_read);
466 		evbuffer_setcb(buf, bufferevent_read_pressure_cb, bufev);
467 		return;
468 	}
469 
470 	if (bufev->readcb != NULL)
471 		(*bufev->readcb)(bufev, bufev->cbarg);
472 	return;
473 
474 retry:
475 	proxy_bufferevent_add(&bufev->ev_read, bufev->timeout_read);
476 	return;
477 
478 err:
479 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
480 }
481 
482 int
483 proxy_bufferevent_add(struct event *ev, int timeout)
484 {
485 	struct timeval tv, *ptv = NULL;
486 
487 	if (timeout) {
488 		timerclear(&tv);
489 		tv.tv_sec = timeout;
490 		ptv = &tv;
491 	}
492 
493 	return (event_add(ev, ptv));
494 }
495 
496 void
497 proxy_tls_writecb(int fd, short event, void *arg)
498 {
499 	struct bufferevent	*bufev = arg;
500 	struct client		*clt = bufev->cbarg;
501 	ssize_t			 ret;
502 	short			 what = EVBUFFER_WRITE;
503 	size_t			 len;
504 
505 	if (event == EV_TIMEOUT) {
506 		what |= EVBUFFER_TIMEOUT;
507 		goto err;
508 	}
509 
510 	if (EVBUFFER_LENGTH(bufev->output)) {
511 		ret = tls_write(clt->clt_ctx,
512 		    EVBUFFER_DATA(bufev->output),
513 		    EVBUFFER_LENGTH(bufev->output));
514 		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
515 			goto retry;
516 		} else if (ret == -1) {
517 			what |= EVBUFFER_ERROR;
518 			goto err;
519 		}
520 		len = ret;
521 		evbuffer_drain(bufev->output, len);
522 	}
523 
524 	if (EVBUFFER_LENGTH(bufev->output) != 0)
525 		proxy_bufferevent_add(&bufev->ev_write, bufev->timeout_write);
526 
527 	if (bufev->writecb != NULL &&
528 	    EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
529 		(*bufev->writecb)(bufev, bufev->cbarg);
530 	return;
531 
532 retry:
533 	proxy_bufferevent_add(&bufev->ev_write, bufev->timeout_write);
534 	return;
535 
536 err:
537 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
538 }
539 
540 void
541 proxy_client_free(struct client *clt)
542 {
543 	if (clt->clt_evasr)
544 		event_asr_abort(clt->clt_evasr);
545 
546 	if (clt->clt_addrinfo)
547 		freeaddrinfo(clt->clt_addrinfo);
548 
549 	if (clt->clt_evconn_live)
550 		event_del(&clt->clt_evconn);
551 
552 	if (clt->clt_fd != -1)
553 		close(clt->clt_fd);
554 
555 	if (clt->clt_ctx)
556 		tls_free(clt->clt_ctx);
557 
558 	if (clt->clt_bev)
559 		bufferevent_free(clt->clt_bev);
560 
561 	free(clt->clt_server_name);
562 	free(clt->clt_script_name);
563 	free(clt->clt_path_info);
564 	free(clt);
565 }