1 /*
2  * Copyright (c) 2022 Omar Polo <op@omarpolo.com>
3  * Copyright (c) 2007-2016 Reyk Floeter <reyk@openbsd.org>
4  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
5  * Copyright (c) 2004 Ryan McBride <mcbride@openbsd.org>
6  * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
7  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
8  * Copyright (c) 2001 Daniel Hartmeier.  All rights reserved.
9  * Copyright (c) 2001 Theo de Raadt.  All rights reserved.
10  *
11  * Permission to use, copy, modify, and distribute this software for any
12  * purpose with or without fee is hereby granted, provided that the above
13  * copyright notice and this permission notice appear in all copies.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
18  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
21  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22  */
23 
24 %{
25 #include <sys/types.h>
26 #include <sys/queue.h>
27 #include <sys/tree.h>
28 #include <sys/uio.h>
29 
30 #include <err.h>
31 #include <event.h>
32 #include <netdb.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <limits.h>
36 #include <stdarg.h>
37 #include <stdint.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <ctype.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <pwd.h>
44 #include <imsg.h>
45 
46 #include "log.h"
47 #include "proc.h"
48 
49 #include "galileo.h"
50 
51 TAILQ_HEAD(files, file)		 files = TAILQ_HEAD_INITIALIZER(files);
52 static struct file {
53 	TAILQ_ENTRY(file)	 entry;
54 	FILE			*stream;
55 	char			*name;
56 	size_t			 ungetpos;
57 	size_t			 ungetsize;
58 	u_char			*ungetbuf;
59 	int			 eof_reached;
60 	int			 lineno;
61 	int			 errors;
62 } *file, *topfile;
63 struct file	*pushfile(const char *, int);
64 int		 popfile(void);
65 int		 yyparse(void);
66 int		 yylex(void);
67 int		 yyerror(const char *, ...)
68     __attribute__((__format__ (printf, 1, 2)))
69     __attribute__((__nonnull__ (1)));
70 int		 kw_cmp(const void *, const void *);
71 int		 lookup(char *);
72 int		 igetc(void);
73 int		 lgetc(int);
74 void		 lungetc(int);
75 int		 findeol(void);
76 
77 TAILQ_HEAD(symhead, sym)	 symhead = TAILQ_HEAD_INITIALIZER(symhead);
78 struct sym {
79 	TAILQ_ENTRY(sym)	 entry;
80 	int			 used;
81 	int			 persist;
82 	char			*nam;
83 	char			*val;
84 };
85 int		 symset(const char *, const char *, int);
86 char		*symget(const char *);
87 
88 int		 getservice(const char *);
89 
90 static struct galileo	*conf = NULL;
91 static struct proxy	*pr = NULL;
92 static int		 errors;
93 
94 typedef struct {
95 	union {
96 		int64_t		 number;
97 		char		*string;
98 	} v;
99 	int lineno;
100 } YYSTYPE;
101 
102 %}
103 
104 %token	INCLUDE ERROR
105 %token	CHROOT HOSTNAME PORT PREFORK PROXY SOURCE STYLESHEET
106 %type	<v.number>	NUMBER
107 %type	<v.number>	port
108 %type	<v.string>	STRING
109 %type	<v.string>	string
110 
111 %%
112 
113 grammar		: /* empty */
114 		| grammar include '\n'
115 		| grammar '\n'
116 		| grammar varset '\n'
117 		| grammar main '\n'
118 		| grammar proxy '\n'
119 		| grammar error '\n'		{ file->errors++; }
120 		;
121 
122 include		: INCLUDE string {
123 			struct file *nfile;
124 
125 			if ((nfile = pushfile($2, 0)) == NULL) {
126 				yyerror("failed to include file %s", $2);
127 				free($2);
128 				YYERROR;
129 			}
130 			free($2);
131 
132 			file = nfile;
133 			lungetc('\n');
134 		}
135 		;
136 
137 varset		: STRING '=' STRING {
138 			char *s = $1;
139 			while (*s++) {
140 				if (isspace((unsigned char)*s)) {
141 					yyerror("macro name cannot contain "
142 					    "whitespace");
143 					free($1);
144 					free($3);
145 					YYERROR;
146 				}
147 			}
148 			if (symset($1, $3, 0) == -1)
149 				fatalx("cannot store variable");
150 			free($1);
151 			free($3);
152 		}
153 		;
154 
155 main		: PREFORK NUMBER {
156 			if ($2 <= 0 || $2 > PROC_MAX_INSTANCES) {
157 				yyerror("invalid number of preforked "
158 				    "proxies: %lld", $2);
159 				YYERROR;
160 			}
161 			conf->sc_prefork = $2;
162 		}
163 		| CHROOT STRING {
164 			size_t n;
165 
166 			n = strlcpy(conf->sc_chroot, $2,
167 			    sizeof(conf->sc_chroot));
168 			if (n >= sizeof(conf->sc_chroot))
169 				yyerror("chroot path too long!");
170 			free($2);
171 		}
172 		;
173 
174 proxy		: PROXY STRING {
175 			struct proxy	*p;
176 			size_t		 n;
177 
178 			if ((p = calloc(1, sizeof(*p))) == NULL)
179 				fatal("calloc");
180 
181 			n = strlcpy(p->pr_conf.host, $2,
182 			    sizeof(p->pr_conf.host));
183 			if (n >= sizeof(p->pr_conf.host)) {
184 				yyerror("server name too long");
185 				free($2);
186 				free(p);
187 				YYERROR;
188 			}
189 			free($2);
190 
191 			pr = p;
192 			TAILQ_INSERT_TAIL(&conf->sc_proxies, p, pr_entry);
193 		} '{' optnl proxyopts_l '}' {
194 			/* check if duplicate */
195 			/* eventually load the tls certs */
196 
197 			pr = NULL;
198 		}
199 		;
200 
201 proxyopts_l	: proxyopts_l proxyoptsl nl
202 		| proxyoptsl optnl
203 		;
204 
205 proxyoptsl	: SOURCE STRING PORT port {
206 			size_t n;
207 
208 			n = strlcpy(pr->pr_conf.proxy_addr, $2,
209 			    sizeof(pr->pr_conf.proxy_addr));
210 			if (n >= sizeof(pr->pr_conf.proxy_addr))
211 				yyerror("proxy source too long!");
212 			pr->pr_conf.proxy_port = $4;
213 
214 			free($2);
215 		}
216 		| HOSTNAME STRING {
217 			size_t n;
218 
219 			n = strlcpy(pr->pr_conf.proxy_name, $2,
220 			    sizeof(pr->pr_conf.proxy_name));
221 			if (n >= sizeof(pr->pr_conf.proxy_name))
222 				yyerror("proxy hostname too long!");
223 			free($2);
224 		}
225 		| STYLESHEET string {
226 			size_t n;
227 
228 			n = strlcpy(pr->pr_conf.stylesheet, $2,
229 			    sizeof(pr->pr_conf.stylesheet));
230 			if (n >= sizeof(pr->pr_conf.stylesheet))
231 				yyerror("stylesheet path too long!");
232 			free($2);
233 		}
234 		;
235 
236 port		: NUMBER {
237 			if ($1 <= 0 || $1 > (int)USHRT_MAX) {
238 				yyerror("invalid port: %lld", $1);
239 				YYERROR;
240 			}
241 			$$ = $1;
242 		}
243 		| STRING {
244 			int val;
245 
246 			if ((val = getservice($1)) == -1) {
247 				yyerror("invalid port: %s", $1);
248 				free($1);
249 				YYERROR;
250 			}
251 			free($1);
252 			$$ = val;
253 		}
254 		;
255 
256 string		: STRING string {
257 			if (asprintf(&$$, "%s%s", $1, $2) == -1)
258 				fatal("asprintf string");
259 			free($1);
260 			free($2);
261 		}
262 		| STRING
263 		;
264 
265 optnl		: '\n' optnl
266 		|
267 		;
268 
269 nl		: '\n' optnl
270 		;
271 
272 %%
273 
274 struct keywords {
275 	const char	*k_name;
276 	int		 k_val;
277 };
278 
279 int
280 yyerror(const char *fmt, ...)
281 {
282 	va_list	 ap;
283 	char	*msg;
284 
285 	file->errors++;
286 	va_start(ap, fmt);
287 	if (vasprintf(&msg, fmt, ap) == -1)
288 		fatal("yyerror vasprintf");
289 	va_end(ap);
290 	log_warnx("%s:%d: %s", file->name, yylval.lineno, msg);
291 	free(msg);
292 	return (0);
293 }
294 
295 int
296 kw_cmp(const void *k, const void *e)
297 {
298 	return (strcmp(k, ((const struct keywords *)e)->k_name));
299 }
300 
301 int
302 lookup(char *s)
303 {
304 	/* this has to be sorted always */
305 	static const struct keywords keywords[] = {
306 		{ "chroot",	CHROOT },
307 		{ "hostname",	HOSTNAME },
308 		{ "include",	INCLUDE },
309 		{ "port",	PORT },
310 		{ "prefork",	PREFORK },
311 		{ "proxy",	PROXY },
312 		{ "source",	SOURCE },
313 		{ "stylesheet",	STYLESHEET},
314 	};
315 	const struct keywords	*p;
316 
317 	p = bsearch(s, keywords, nitems(keywords), sizeof(keywords[0]),
318 	    kw_cmp);
319 
320 	if (p)
321 		return (p->k_val);
322 	else
323 		return (STRING);
324 }
325 
326 #define START_EXPAND	1
327 #define DONE_EXPAND	2
328 
329 static int	expanding;
330 
331 int
332 igetc(void)
333 {
334 	int	c;
335 
336 	while (1) {
337 		if (file->ungetpos > 0)
338 			c = file->ungetbuf[--file->ungetpos];
339 		else
340 			c = getc(file->stream);
341 
342 		if (c == START_EXPAND)
343 			expanding = 1;
344 		else if (c == DONE_EXPAND)
345 			expanding = 0;
346 		else
347 			break;
348 	}
349 	return (c);
350 }
351 
352 int
353 lgetc(int quotec)
354 {
355 	int		c, next;
356 
357 	if (quotec) {
358 		if ((c = igetc()) == EOF) {
359 			yyerror("reached end of file while parsing "
360 			    "quoted string");
361 			if (file == topfile || popfile() == EOF)
362 				return (EOF);
363 			return (quotec);
364 		}
365 		return (c);
366 	}
367 
368 	while ((c = igetc()) == '\\') {
369 		next = igetc();
370 		if (next != '\n') {
371 			c = next;
372 			break;
373 		}
374 		yylval.lineno = file->lineno;
375 		file->lineno++;
376 	}
377 	if (c == '\t' || c == ' ') {
378 		/* Compress blanks to a single space. */
379 		do {
380 			c = getc(file->stream);
381 		} while (c == '\t' || c == ' ');
382 		ungetc(c, file->stream);
383 		c = ' ';
384 	}
385 
386 	if (c == EOF) {
387 		/*
388 		 * Fake EOL when hit EOF for the first time. This gets line
389 		 * count right if last line in included file is syntactically
390 		 * invalid and has no newline.
391 		 */
392 		if (file->eof_reached == 0) {
393 			file->eof_reached = 1;
394 			return ('\n');
395 		}
396 		while (c == EOF) {
397 			if (file == topfile || popfile() == EOF)
398 				return (EOF);
399 			c = igetc();
400 		}
401 	}
402 	return (c);
403 }
404 
405 void
406 lungetc(int c)
407 {
408 	if (c == EOF)
409 		return;
410 
411 	if (file->ungetpos >= file->ungetsize) {
412 		void *p = reallocarray(file->ungetbuf, file->ungetsize, 2);
413 		if (p == NULL)
414 			err(1, "%s", __func__);
415 		file->ungetbuf = p;
416 		file->ungetsize *= 2;
417 	}
418 	file->ungetbuf[file->ungetpos++] = c;
419 }
420 
421 int
422 findeol(void)
423 {
424 	int	c;
425 
426 	/* skip to either EOF or the first real EOL */
427 	while (1) {
428 		c = lgetc(0);
429 		if (c == '\n') {
430 			file->lineno++;
431 			break;
432 		}
433 		if (c == EOF)
434 			break;
435 	}
436 	return (ERROR);
437 }
438 
439 int
440 yylex(void)
441 {
442 	char	 buf[8096];
443 	char	*p, *val;
444 	int	 quotec, next, c;
445 	int	 token;
446 
447 top:
448 	p = buf;
449 	while ((c = lgetc(0)) == ' ' || c == '\t')
450 		; /* nothing */
451 
452 	yylval.lineno = file->lineno;
453 	if (c == '#')
454 		while ((c = lgetc(0)) != '\n' && c != EOF)
455 			; /* nothing */
456 	if (c == '$' && !expanding) {
457 		while (1) {
458 			if ((c = lgetc(0)) == EOF)
459 				return (0);
460 
461 			if (p + 1 >= buf + sizeof(buf) - 1) {
462 				yyerror("string too long");
463 				return (findeol());
464 			}
465 			if (isalnum(c) || c == '_') {
466 				*p++ = c;
467 				continue;
468 			}
469 			*p = '\0';
470 			lungetc(c);
471 			break;
472 		}
473 		val = symget(buf);
474 		if (val == NULL) {
475 			yyerror("macro '%s' not defined", buf);
476 			return (findeol());
477 		}
478 		p = val + strlen(val) - 1;
479 		lungetc(DONE_EXPAND);
480 		while (p >= val) {
481 			lungetc((unsigned char)*p);
482 			p--;
483 		}
484 		lungetc(START_EXPAND);
485 		goto top;
486 	}
487 
488 	switch (c) {
489 	case '\'':
490 	case '"':
491 		quotec = c;
492 		while (1) {
493 			if ((c = lgetc(quotec)) == EOF)
494 				return (0);
495 			if (c == '\n') {
496 				file->lineno++;
497 				continue;
498 			} else if (c == '\\') {
499 				if ((next = lgetc(quotec)) == EOF)
500 					return (0);
501 				if (next == quotec || next == ' ' ||
502 				    next == '\t')
503 					c = next;
504 				else if (next == '\n') {
505 					file->lineno++;
506 					continue;
507 				} else
508 					lungetc(next);
509 			} else if (c == quotec) {
510 				*p = '\0';
511 				break;
512 			} else if (c == '\0') {
513 				yyerror("syntax error");
514 				return (findeol());
515 			}
516 			if (p + 1 >= buf + sizeof(buf) - 1) {
517 				yyerror("string too long");
518 				return (findeol());
519 			}
520 			*p++ = c;
521 		}
522 		yylval.v.string = strdup(buf);
523 		if (yylval.v.string == NULL)
524 			fatal("yylex: strdup");
525 		return (STRING);
526 	}
527 
528 #define allowed_to_end_number(x) \
529 	(isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=')
530 
531 	if (c == '-' || isdigit(c)) {
532 		do {
533 			*p++ = c;
534 			if ((size_t)(p-buf) >= sizeof(buf)) {
535 				yyerror("string too long");
536 				return (findeol());
537 			}
538 		} while ((c = lgetc(0)) != EOF && isdigit(c));
539 		lungetc(c);
540 		if (p == buf + 1 && buf[0] == '-')
541 			goto nodigits;
542 		if (c == EOF || allowed_to_end_number(c)) {
543 			const char *errstr = NULL;
544 
545 			*p = '\0';
546 			yylval.v.number = strtonum(buf, LLONG_MIN,
547 			    LLONG_MAX, &errstr);
548 			if (errstr) {
549 				yyerror("\"%s\" invalid number: %s",
550 				    buf, errstr);
551 				return (findeol());
552 			}
553 			return (NUMBER);
554 		} else {
555 nodigits:
556 			while (p > buf + 1)
557 				lungetc((unsigned char)*--p);
558 			c = (unsigned char)*--p;
559 			if (c == '-')
560 				return (c);
561 		}
562 	}
563 
564 #define allowed_in_string(x) \
565 	(isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \
566 	x != '{' && x != '}' && \
567 	x != '!' && x != '=' && x != '#' && \
568 	x != ','))
569 
570 	if (isalnum(c) || c == ':' || c == '_' || c == '/') {
571 		do {
572 			*p++ = c;
573 			if ((size_t)(p-buf) >= sizeof(buf)) {
574 				yyerror("string too long");
575 				return (findeol());
576 			}
577 		} while ((c = lgetc(0)) != EOF && (allowed_in_string(c)));
578 		lungetc(c);
579 		*p = '\0';
580 		if ((token = lookup(buf)) == STRING)
581 			if ((yylval.v.string = strdup(buf)) == NULL)
582 				fatal("yylex: strdup");
583 		return (token);
584 	}
585 	if (c == '\n') {
586 		yylval.lineno = file->lineno;
587 		file->lineno++;
588 	}
589 	if (c == EOF)
590 		return (0);
591 	return (c);
592 }
593 
594 struct file *
595 pushfile(const char *name, int secret)
596 {
597 	struct file	*nfile;
598 
599 	if ((nfile = calloc(1, sizeof(struct file))) == NULL) {
600 		log_warn("%s", __func__);
601 		return (NULL);
602 	}
603 	if ((nfile->name = strdup(name)) == NULL) {
604 		log_warn("%s", __func__);
605 		free(nfile);
606 		return (NULL);
607 	}
608 	if ((nfile->stream = fopen(nfile->name, "r")) == NULL) {
609 		free(nfile->name);
610 		free(nfile);
611 		return (NULL);
612 	}
613 	nfile->lineno = TAILQ_EMPTY(&files) ? 1 : 0;
614 	nfile->ungetsize = 16;
615 	nfile->ungetbuf = malloc(nfile->ungetsize);
616 	if (nfile->ungetbuf == NULL) {
617 		log_warn("%s", __func__);
618 		fclose(nfile->stream);
619 		free(nfile->name);
620 		free(nfile);
621 		return (NULL);
622 	}
623 	TAILQ_INSERT_TAIL(&files, nfile, entry);
624 	return (nfile);
625 }
626 
627 int
628 popfile(void)
629 {
630 	struct file	*prev;
631 
632 	if ((prev = TAILQ_PREV(file, files, entry)) != NULL)
633 		prev->errors += file->errors;
634 
635 	TAILQ_REMOVE(&files, file, entry);
636 	fclose(file->stream);
637 	free(file->name);
638 	free(file->ungetbuf);
639 	free(file);
640 	file = prev;
641 	return (file ? 0 : EOF);
642 }
643 
644 int
645 parse_config(const char *filename, struct galileo *env)
646 {
647 	struct sym	*sym, *next;
648 	size_t		 n;
649 
650 	conf = env;
651 
652 	n = strlcpy(conf->sc_conffile, filename, sizeof(conf->sc_conffile));
653 	if (n >= sizeof(conf->sc_conffile)) {
654 		log_warn("path too long: %s", filename);
655 		return (-1);
656 	}
657 
658 	if ((file = pushfile(filename, 0)) == NULL) {
659 		log_warn("failed to open %s", filename);
660 		return (-1);
661 	}
662 	topfile = file;
663 	setservent(1);
664 
665 	yyparse();
666 	errors = file->errors;
667 	popfile();
668 
669 	endservent();
670 
671 	/* Free macros and check which have not been used. */
672 	TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) {
673 		if (!sym->used)
674 			fprintf(stderr, "warning: macro `%s' not used\n",
675 			    sym->nam);
676 		if (!sym->persist) {
677 			free(sym->nam);
678 			free(sym->val);
679 			TAILQ_REMOVE(&symhead, sym, entry);
680 			free(sym);
681 		}
682 	}
683 
684 	if (errors)
685 		return (-1);
686 
687 	return (0);
688 }
689 
690 int
691 symset(const char *nam, const char *val, int persist)
692 {
693 	struct sym	*sym;
694 
695 	TAILQ_FOREACH(sym, &symhead, entry) {
696 		if (strcmp(nam, sym->nam) == 0)
697 			break;
698 	}
699 
700 	if (sym != NULL) {
701 		if (sym->persist == 1)
702 			return (0);
703 		else {
704 			free(sym->nam);
705 			free(sym->val);
706 			TAILQ_REMOVE(&symhead, sym, entry);
707 			free(sym);
708 		}
709 	}
710 	if ((sym = calloc(1, sizeof(*sym))) == NULL)
711 		return (-1);
712 
713 	sym->nam = strdup(nam);
714 	if (sym->nam == NULL) {
715 		free(sym);
716 		return (-1);
717 	}
718 	sym->val = strdup(val);
719 	if (sym->val == NULL) {
720 		free(sym->nam);
721 		free(sym);
722 		return (-1);
723 	}
724 	sym->used = 0;
725 	sym->persist = persist;
726 	TAILQ_INSERT_TAIL(&symhead, sym, entry);
727 	return (0);
728 }
729 
730 int
731 cmdline_symset(char *s)
732 {
733 	char	*sym, *val;
734 	int	ret;
735 
736 	if ((val = strrchr(s, '=')) == NULL)
737 		return (-1);
738 	sym = strndup(s, val - s);
739 	if (sym == NULL)
740 		fatal("%s: strndup", __func__);
741 	ret = symset(sym, val + 1, 1);
742 	free(sym);
743 
744 	return (ret);
745 }
746 
747 char *
748 symget(const char *nam)
749 {
750 	struct sym	*sym;
751 
752 	TAILQ_FOREACH(sym, &symhead, entry) {
753 		if (strcmp(nam, sym->nam) == 0) {
754 			sym->used = 1;
755 			return (sym->val);
756 		}
757 	}
758 	return (NULL);
759 }
760 
761 int
762 getservice(const char *n)
763 {
764 	struct servent	*s;
765 	const char	*errstr;
766 	long long	 llval;
767 
768 	llval = strtonum(n, 0, UINT16_MAX, &errstr);
769 	if (errstr) {
770 		s = getservbyname(n, "tcp");
771 		if (s == NULL)
772 			s = getservbyname(n, "udp");
773 		if (s == NULL)
774 			return (-1);
775 		return (ntohs(s->s_port));
776 	}
777 
778 	return ((unsigned short)llval);
779 }