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Date:: Fri Dec 30 14:58:03 2022 UTC
Message:: gotwebd: add an RSS feed for the tags ok tracey@
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1 /*
2  * Copyright (c) 2020-2022 Tracey Emery <tracey@traceyemery.net>
3  * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
4  * Copyright (c) 2013 Florian Obser <florian@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <arpa/inet.h>
20 #include <sys/queue.h>
21 #include <sys/socket.h>
22 #include <sys/types.h>
23 #include <sys/uio.h>
24 
25 #include <errno.h>
26 #include <event.h>
27 #include <imsg.h>
28 #include <stdarg.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <time.h>
33 #include <unistd.h>
34 
35 #include "got_error.h"
36 
37 #include "got_compat.h"
38 
39 #include "proc.h"
40 #include "gotwebd.h"
41 #include "tmpl.h"
42 
43 size_t	 fcgi_parse_record(uint8_t *, size_t, struct request *);
44 void	 fcgi_parse_begin_request(uint8_t *, uint16_t, struct request *,
45 	    uint16_t);
46 void	 fcgi_parse_params(uint8_t *, uint16_t, struct request *, uint16_t);
47 int	 fcgi_send_response(struct request *, int, const void *, size_t);
48 
49 void	 dump_fcgi_record_header(const char *, struct fcgi_record_header *);
50 void	 dump_fcgi_begin_request_body(const char *,
51 	    struct fcgi_begin_request_body *);
52 void	 dump_fcgi_end_request_body(const char *,
53 	    struct fcgi_end_request_body *);
54 
55 extern int	 cgi_inflight;
56 extern volatile int client_cnt;
57 
58 void
59 fcgi_request(int fd, short events, void *arg)
60 {
61 	struct request *c = arg;
62 	ssize_t n;
63 	size_t parsed = 0;
64 
65 	n = read(fd, c->buf + c->buf_pos + c->buf_len,
66 	    FCGI_RECORD_SIZE - c->buf_pos-c->buf_len);
67 
68 	switch (n) {
69 	case -1:
70 		switch (errno) {
71 		case EINTR:
72 		case EAGAIN:
73 			return;
74 		default:
75 			goto fail;
76 		}
77 		break;
78 
79 	case 0:
80 		log_debug("closed connection");
81 		goto fail;
82 	default:
83 		break;
84 	}
85 
86 	c->buf_len += n;
87 
88 	/*
89 	 * Parse the records as they are received. Per the FastCGI
90 	 * specification, the server need only receive the FastCGI
91 	 * parameter records in full; it is free to begin execution
92 	 * at that point, which is what happens here.
93 	 */
94 	do {
95 		parsed = fcgi_parse_record(c->buf + c->buf_pos, c->buf_len, c);
96 		if (parsed != 0) {
97 			c->buf_pos += parsed;
98 			c->buf_len -= parsed;
99 		}
100 	} while (parsed > 0 && c->buf_len > 0);
101 
102 	/* Make space for further reads */
103 	if (parsed != 0)
104 		if (c->buf_len > 0) {
105 			bcopy(c->buf + c->buf_pos, c->buf, c->buf_len);
106 			c->buf_pos = 0;
107 		}
108 	return;
109 fail:
110 	fcgi_cleanup_request(c);
111 }
112 
113 size_t
114 fcgi_parse_record(uint8_t *buf, size_t n, struct request *c)
115 {
116 	struct fcgi_record_header *h;
117 
118 	if (n < sizeof(struct fcgi_record_header))
119 		 return 0;
120 
121 	h = (struct fcgi_record_header*) buf;
122 
123 	dump_fcgi_record("", h);
124 
125 	if (n < sizeof(struct fcgi_record_header) + ntohs(h->content_len)
126 	    + h->padding_len)
127 		 return 0;
128 
129 	if (h->version != 1)
130 		log_warn("wrong version");
131 
132 	switch (h->type) {
133 	case FCGI_BEGIN_REQUEST:
134 		fcgi_parse_begin_request(buf +
135 		    sizeof(struct fcgi_record_header),
136 		    ntohs(h->content_len), c, ntohs(h->id));
137 		break;
138 	case FCGI_PARAMS:
139 		fcgi_parse_params(buf + sizeof(struct fcgi_record_header),
140 		    ntohs(h->content_len), c, ntohs(h->id));
141 		break;
142 	case FCGI_STDIN:
143 	case FCGI_ABORT_REQUEST:
144 		if (c->sock->client_status != CLIENT_DISCONNECT &&
145 		    c->outbuf_len != 0) {
146 			fcgi_send_response(c, FCGI_STDOUT, c->outbuf,
147 			    c->outbuf_len);
148 		}
149 
150 		fcgi_create_end_record(c);
151 		fcgi_cleanup_request(c);
152 		return 0;
153 	default:
154 		log_warn("unimplemented type %d", h->type);
155 		break;
156 	}
157 
158 	return (sizeof(struct fcgi_record_header) + ntohs(h->content_len)
159 	    + h->padding_len);
160 }
161 
162 void
163 fcgi_parse_begin_request(uint8_t *buf, uint16_t n,
164     struct request *c, uint16_t id)
165 {
166 	/* XXX -- FCGI_CANT_MPX_CONN */
167 	if (c->request_started) {
168 		log_warn("unexpected FCGI_BEGIN_REQUEST, ignoring");
169 		return;
170 	}
171 
172 	if (n != sizeof(struct fcgi_begin_request_body)) {
173 		log_warn("wrong size %d != %lu", n,
174 		    sizeof(struct fcgi_begin_request_body));
175 		return;
176 	}
177 
178 	c->request_started = 1;
179 	c->id = id;
180 }
181 
182 void
183 fcgi_parse_params(uint8_t *buf, uint16_t n, struct request *c, uint16_t id)
184 {
185 	uint32_t name_len, val_len;
186 	uint8_t *sd, *val;
187 
188 	if (!c->request_started) {
189 		log_warn("FCGI_PARAMS without FCGI_BEGIN_REQUEST, ignoring");
190 		return;
191 	}
192 
193 	if (c->id != id) {
194 		log_warn("unexpected id, ignoring");
195 		return;
196 	}
197 
198 	if (n == 0) {
199 		gotweb_process_request(c);
200 		return;
201 	}
202 
203 	while (n > 0) {
204 		if (buf[0] >> 7 == 0) {
205 			name_len = buf[0];
206 			n--;
207 			buf++;
208 		} else {
209 			if (n > 3) {
210 				name_len = ((buf[0] & 0x7f) << 24) +
211 				    (buf[1] << 16) + (buf[2] << 8) + buf[3];
212 				n -= 4;
213 				buf += 4;
214 			} else
215 				return;
216 		}
217 
218 		if (n == 0)
219 			return;
220 
221 		if (buf[0] >> 7 == 0) {
222 			val_len = buf[0];
223 			n--;
224 			buf++;
225 		} else {
226 			if (n > 3) {
227 				val_len = ((buf[0] & 0x7f) << 24) +
228 					(buf[1] << 16) + (buf[2] << 8) +
229 					buf[3];
230 				n -= 4;
231 				buf += 4;
232 			} else
233 				return;
234 		}
235 
236 		if (n < name_len + val_len)
237 			return;
238 
239 		val = buf + name_len;
240 
241 		if (c->querystring[0] == '\0' &&
242 		    val_len < MAX_QUERYSTRING &&
243 		    name_len == 12 &&
244 		    strncmp(buf, "QUERY_STRING", 12) == 0) {
245 			memcpy(c->querystring, val, val_len);
246 			c->querystring[val_len] = '\0';
247 		}
248 
249 		if (c->http_host[0] == '\0' &&
250 		    val_len < GOTWEBD_MAXTEXT &&
251 		    name_len == 9 &&
252 		    strncmp(buf, "HTTP_HOST", 9) == 0) {
253 			memcpy(c->http_host, val, val_len);
254 			c->http_host[val_len] = '\0';
255 
256 			/*
257 			 * lazily get subdomain
258 			 * will only get domain if no subdomain exists
259 			 * this can still work if gotweb server name is the same
260 			 */
261 			sd = strchr(c->http_host, '.');
262 			if (sd)
263 				*sd = '\0';
264 		}
265 
266 		if (c->document_uri[0] == '\0' &&
267 		    val_len < MAX_DOCUMENT_URI &&
268 		    name_len == 12 &&
269 		    strncmp(buf, "DOCUMENT_URI", 12) == 0) {
270 			memcpy(c->document_uri, val, val_len);
271 			c->document_uri[val_len] = '\0';
272 		}
273 
274 		if (c->server_name[0] == '\0' &&
275 		    val_len < MAX_SERVER_NAME &&
276 		    name_len == 11 &&
277 		    strncmp(buf, "SERVER_NAME", 11) == 0) {
278 			memcpy(c->server_name, val, val_len);
279 			c->server_name[val_len] = '\0';
280 		}
281 
282 		if (name_len == 5 &&
283 		    strncmp(buf, "HTTPS", 5) == 0)
284 			c->https = 1;
285 
286 		buf += name_len + val_len;
287 		n -= name_len - val_len;
288 	}
289 }
290 
291 void
292 fcgi_timeout(int fd, short events, void *arg)
293 {
294 	fcgi_cleanup_request((struct request*) arg);
295 }
296 
297 int
298 fcgi_puts(struct template *tp, const char *str)
299 {
300 	if (str == NULL)
301 		return 0;
302 	return fcgi_gen_binary_response(tp->tp_arg, str, strlen(str));
303 }
304 
305 int
306 fcgi_putc(struct template *tp, int ch)
307 {
308 	uint8_t c = ch;
309 	return fcgi_gen_binary_response(tp->tp_arg, &c, 1);
310 }
311 
312 int
313 fcgi_vprintf(struct request *c, const char *fmt, va_list ap)
314 {
315 	char *str;
316 	int r;
317 
318 	r = vasprintf(&str, fmt, ap);
319 	if (r == -1) {
320 		log_warn("%s: asprintf", __func__);
321 		return -1;
322 	}
323 
324 	r = fcgi_gen_binary_response(c, str, r);
325 	free(str);
326 	return r;
327 }
328 
329 int
330 fcgi_printf(struct request *c, const char *fmt, ...)
331 {
332 	va_list ap;
333 	int r;
334 
335 	va_start(ap, fmt);
336 	r = fcgi_vprintf(c, fmt, ap);
337 	va_end(ap);
338 
339 	return r;
340 }
341 
342 int
343 fcgi_gen_binary_response(struct request *c, const uint8_t *data, int len)
344 {
345 	int r;
346 
347 	if (c->sock->client_status == CLIENT_DISCONNECT)
348 		return -1;
349 
350 	if (data == NULL || len == 0)
351 		return 0;
352 
353 	/*
354 	 * special case: send big replies -like blobs- directly
355 	 * without copying.
356 	 */
357 	if (len > sizeof(c->outbuf)) {
358 		if (c->outbuf_len > 0) {
359 			fcgi_send_response(c, FCGI_STDOUT,
360 			    c->outbuf, c->outbuf_len);
361 			c->outbuf_len = 0;
362 		}
363 		return fcgi_send_response(c, FCGI_STDOUT, data, len);
364 	}
365 
366 	if (len < sizeof(c->outbuf) - c->outbuf_len) {
367 		memcpy(c->outbuf + c->outbuf_len, data, len);
368 		c->outbuf_len += len;
369 		return 0;
370 	}
371 
372 	r = fcgi_send_response(c, FCGI_STDOUT, c->outbuf, c->outbuf_len);
373 	if (r == -1)
374 		return -1;
375 
376 	memcpy(c->outbuf, data, len);
377 	c->outbuf_len = len;
378 	return 0;
379 }
380 
381 static int
382 send_response(struct request *c, int type, const uint8_t *data,
383     size_t len)
384 {
385 	static const uint8_t padding[FCGI_PADDING_SIZE];
386 	struct fcgi_record_header header;
387 	struct iovec iov[3];
388 	struct timespec ts;
389 	ssize_t nw;
390 	size_t padded_len, tot;
391 	int i, err = 0, th = 2000;
392 
393 	ts.tv_sec = 0;
394 	ts.tv_nsec = 50;
395 
396 	memset(&header, 0, sizeof(header));
397 	header.version = 1;
398 	header.type = type;
399 	header.id = htons(c->id);
400 	header.content_len = htons(len);
401 
402 	/* The FastCGI spec suggests to align the output buffer */
403 	tot = sizeof(header) + len;
404 	padded_len = FCGI_ALIGN(tot);
405 	if (padded_len > tot) {
406 		header.padding_len = padded_len - tot;
407 		tot += header.padding_len;
408 	}
409 
410 	iov[0].iov_base = &header;
411 	iov[0].iov_len = sizeof(header);
412 
413 	iov[1].iov_base = (void *)data;
414 	iov[1].iov_len = len;
415 
416 	iov[2].iov_base = (void *)padding;
417 	iov[2].iov_len = header.padding_len;
418 
419 	dump_fcgi_record("resp ", &header);
420 
421 	/*
422 	 * XXX: add some simple write heuristics here
423 	 * On slower VMs, spotty connections, etc., we don't want to go right to
424 	 * disconnect. Let's at least try to write the data a few times before
425 	 * giving up.
426 	 */
427 	while (tot > 0) {
428 		nw = writev(c->fd, iov, nitems(iov));
429 		if (nw == 0) {
430 			c->sock->client_status = CLIENT_DISCONNECT;
431 			break;
432 		}
433 		if (nw == -1) {
434 			err++;
435 			if (errno == EAGAIN && err < th) {
436 				nanosleep(&ts, NULL);
437 				continue;
438 			}
439 			log_warn("%s: write failure", __func__);
440 			c->sock->client_status = CLIENT_DISCONNECT;
441 			return -1;
442 		}
443 
444 		if (nw != tot)
445 			log_debug("%s: partial write: %zu vs %zu", __func__,
446 			    nw, tot);
447 
448 		tot -= nw;
449 		for (i = 0; i < nitems(iov); ++i) {
450 			if (nw < iov[i].iov_len) {
451 				iov[i].iov_base += nw;
452 				iov[i].iov_len -= nw;
453 				break;
454 			}
455 			nw -= iov[i].iov_len;
456 			iov[i].iov_len = 0;
457 		}
458 	}
459 
460 	return 0;
461 }
462 
463 int
464 fcgi_send_response(struct request *c, int type, const void *data,
465     size_t len)
466 {
467 	if (c->sock->client_status == CLIENT_DISCONNECT)
468 		return -1;
469 
470 	while (len > FCGI_CONTENT_SIZE) {
471 		if (send_response(c, type, data, len) == -1)
472 			return -1;
473 
474 		data += FCGI_CONTENT_SIZE;
475 		len -= FCGI_CONTENT_SIZE;
476 	}
477 
478 	if (len == 0)
479 		return 0;
480 
481 	return send_response(c, type, data, len);
482 }
483 
484 void
485 fcgi_create_end_record(struct request *c)
486 {
487 	struct fcgi_end_request_body end_request;
488 
489 	memset(&end_request, 0, sizeof(end_request));
490 	end_request.app_status = htonl(0); /* script status */
491 	end_request.protocol_status = FCGI_REQUEST_COMPLETE;
492 
493 	fcgi_send_response(c, FCGI_END_REQUEST, &end_request,
494 	    sizeof(end_request));
495 }
496 
497 void
498 fcgi_cleanup_request(struct request *c)
499 {
500 	cgi_inflight--;
501 	client_cnt--;
502 
503 	evtimer_del(&c->tmo);
504 	if (event_initialized(&c->ev))
505 		event_del(&c->ev);
506 
507 	close(c->fd);
508 	template_free(c->tp);
509 	gotweb_free_transport(c->t);
510 	free(c);
511 }
512 
513 void
514 dump_fcgi_record(const char *p, struct fcgi_record_header *h)
515 {
516 	dump_fcgi_record_header(p, h);
517 
518 	if (h->type == FCGI_BEGIN_REQUEST)
519 		dump_fcgi_begin_request_body(p,
520 		    (struct fcgi_begin_request_body *)(h + 1));
521 	else if (h->type == FCGI_END_REQUEST)
522 		dump_fcgi_end_request_body(p,
523 		    (struct fcgi_end_request_body *)(h + 1));
524 }
525 
526 void
527 dump_fcgi_record_header(const char* p, struct fcgi_record_header *h)
528 {
529 	log_debug("%sversion:         %d", p, h->version);
530 	log_debug("%stype:            %d", p, h->type);
531 	log_debug("%srequestId:       %d", p, ntohs(h->id));
532 	log_debug("%scontentLength:   %d", p, ntohs(h->content_len));
533 	log_debug("%spaddingLength:   %d", p, h->padding_len);
534 	log_debug("%sreserved:        %d", p, h->reserved);
535 }
536 
537 void
538 dump_fcgi_begin_request_body(const char *p, struct fcgi_begin_request_body *b)
539 {
540 	log_debug("%srole             %d", p, ntohs(b->role));
541 	log_debug("%sflags            %d", p, b->flags);
542 }
543 
544 void
545 dump_fcgi_end_request_body(const char *p, struct fcgi_end_request_body *b)
546 {
547 	log_debug("%sappStatus:       %d", p, ntohl(b->app_status));
548 	log_debug("%sprotocolStatus:  %d", p, b->protocol_status);
549 }