xref: /openbsd/usr.sbin/mrouted/cfparse.y (revision d415bd75) 
1 %{
2 /*	$NetBSD: cfparse.y,v 1.4 1995/12/10 10:06:57 mycroft Exp $	*/
3 
4 /*
5  * Configuration file parser for mrouted.
6  *
7  * Written by Bill Fenner, NRL, 1994
8  * Copyright (c) 1994
9  * Naval Research Laboratory (NRL/CCS)
10  *                    and the
11  * Defense Advanced Research Projects Agency (DARPA)
12  *
13  * All Rights Reserved.
14  *
15  * Permission to use, copy, modify and distribute this software and its
16  * documentation is hereby granted, provided that both the copyright notice and
17  * this permission notice appear in all copies of the software, derivative
18  * works or modified versions, and any portions thereof, and that both notices
19  * appear in supporting documentation.
20  *
21  * NRL AND DARPA ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION AND
22  * DISCLAIM ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM
23  * THE USE OF THIS SOFTWARE.
24  */
25 #include <stdio.h>
26 #include <string.h>
27 #include <stdarg.h>
28 #include "defs.h"
29 #include <netdb.h>
30 #include <ifaddrs.h>
31 
32 /*
33  * Local function declarations
34  */
35 static void		fatal(const char *fmt, ...)
36     __attribute__((__format__ (printf, 1, 2)))
37     __attribute__((__nonnull__ (1)));
38 static void		warn(const char *fmt, ...)
39     __attribute__((__format__ (printf, 1, 2)))
40     __attribute__((__nonnull__ (1)));
41 static void		yyerror(char *s);
42 static char *		next_word(void);
43 static int		yylex(void);
44 static u_int32_t	valid_if(char *s);
45 static const char *	ifconfaddr(u_int32_t a);
46 int			yyparse(void);
47 
48 static FILE *f;
49 
50 extern int udp_socket;
51 char *configfilename = _PATH_MROUTED_CONF;
52 
53 extern int cache_lifetime;
54 extern int max_prune_lifetime;
55 
56 static int lineno;
57 
58 static struct uvif *v;
59 
60 static int order;
61 
62 struct addrmask {
63 	u_int32_t	addr;
64 	int	mask;
65 };
66 
67 struct boundnam {
68 	char		*name;
69 	struct addrmask	 bound;
70 };
71 
72 #define MAXBOUNDS 20
73 
74 struct boundnam boundlist[MAXBOUNDS];	/* Max. of 20 named boundaries */
75 int numbounds = 0;			/* Number of named boundaries */
76 
77 %}
78 
79 %union
80 {
81 	int num;
82 	char *ptr;
83 	struct addrmask addrmask;
84 	u_int32_t addr;
85 };
86 
87 %token CACHE_LIFETIME PRUNING
88 %token PHYINT TUNNEL NAME
89 %token DISABLE IGMPV1 SRCRT
90 %token METRIC THRESHOLD RATE_LIMIT BOUNDARY NETMASK ALTNET
91 %token <num> BOOLEAN
92 %token <num> NUMBER
93 %token <ptr> STRING
94 %token <addrmask> ADDRMASK
95 %token <addr> ADDR
96 
97 %type <addr> interface addrname
98 %type <addrmask> bound boundary addrmask
99 
100 %start conf
101 
102 %%
103 
104 conf	: stmts
105 	;
106 
107 stmts	: /* Empty */
108 	| stmts stmt
109 	;
110 
111 stmt	: error
112 	| PHYINT interface		{
113 
114 			vifi_t vifi;
115 
116 			if (order)
117 			    fatal("phyints must appear before tunnels");
118 
119 			for (vifi = 0, v = uvifs;
120 			     vifi < numvifs;
121 			     ++vifi, ++v)
122 			    if (!(v->uv_flags & VIFF_TUNNEL) &&
123 				$2 == v->uv_lcl_addr)
124 				break;
125 
126 			if (vifi == numvifs)
127 			    fatal("%s is not a configured interface",
128 				inet_fmt($2,s1));
129 
130 					}
131 		ifmods
132 	| TUNNEL interface addrname	{
133 			const char *ifname;
134 			struct ifreq ffr;
135 			vifi_t vifi;
136 
137 			order++;
138 
139 			ifname = ifconfaddr($2);
140 			if (ifname == 0)
141 			    fatal("Tunnel local address %s is not mine",
142 				inet_fmt($2, s1));
143 
144 			strlcpy(ffr.ifr_name, ifname, sizeof(ffr.ifr_name));
145 			if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ffr) == -1)
146 			    fatal("ioctl SIOCGIFFLAGS on %s",ffr.ifr_name);
147 			if (ffr.ifr_flags & IFF_LOOPBACK)
148 			    fatal("Tunnel local address %s is a loopback interface",
149 				inet_fmt($2, s1));
150 
151 			if (ifconfaddr($3) != 0)
152 			    fatal("Tunnel remote address %s is one of mine",
153 				inet_fmt($3, s1));
154 
155 			for (vifi = 0, v = uvifs;
156 			     vifi < numvifs;
157 			     ++vifi, ++v)
158 			    if (v->uv_flags & VIFF_TUNNEL) {
159 				if ($3 == v->uv_rmt_addr)
160 				    fatal("Duplicate tunnel to %s",
161 					inet_fmt($3, s1));
162 			    } else if (!(v->uv_flags & VIFF_DISABLED)) {
163 				if (($3 & v->uv_subnetmask) == v->uv_subnet)
164 				    fatal("Unnecessary tunnel to %s",
165 					inet_fmt($3,s1));
166 			    }
167 
168 			if (numvifs == MAXVIFS)
169 			    fatal("too many vifs");
170 
171 			v = &uvifs[numvifs];
172 			v->uv_flags	= VIFF_TUNNEL;
173 			v->uv_metric	= DEFAULT_METRIC;
174 			v->uv_rate_limit= DEFAULT_TUN_RATE_LIMIT;
175 			v->uv_threshold	= DEFAULT_THRESHOLD;
176 			v->uv_lcl_addr	= $2;
177 			v->uv_rmt_addr	= $3;
178 			v->uv_subnet	= 0;
179 			v->uv_subnetmask= 0;
180 			v->uv_subnetbcast= 0;
181 			strncpy(v->uv_name, ffr.ifr_name, IFNAMSIZ);
182 			v->uv_groups	= NULL;
183 			v->uv_neighbors	= NULL;
184 			v->uv_acl	= NULL;
185 			v->uv_addrs	= NULL;
186 
187 			if (!(ffr.ifr_flags & IFF_UP)) {
188 			    v->uv_flags |= VIFF_DOWN;
189 			    vifs_down = TRUE;
190 			}
191 					}
192 		tunnelmods
193 					{
194 			logit(LOG_INFO, 0,
195 			    "installing tunnel from %s to %s as vif #%u - rate=%d",
196 			    inet_fmt($2, s1), inet_fmt($3, s2),
197 			    numvifs, v->uv_rate_limit);
198 
199 			++numvifs;
200 					}
201 	| PRUNING BOOLEAN	    { pruning = $2; }
202 	| CACHE_LIFETIME NUMBER     { cache_lifetime = $2;
203 				      max_prune_lifetime = cache_lifetime * 2;
204 				    }
205 	| NAME STRING boundary	    { if (numbounds >= MAXBOUNDS) {
206 					fatal("Too many named boundaries (max %d)", MAXBOUNDS);
207 				      }
208 
209 				      boundlist[numbounds].name = strdup($2);
210 				      boundlist[numbounds++].bound = $3;
211 				    }
212 	;
213 
214 tunnelmods	: /* empty */
215 	| tunnelmods tunnelmod
216 	;
217 
218 tunnelmod	: mod
219 	| SRCRT			{ fatal("Source-route tunnels not supported"); }
220 	;
221 
222 ifmods	: /* empty */
223 	| ifmods ifmod
224 	;
225 
226 ifmod	: mod
227 	| DISABLE		{ v->uv_flags |= VIFF_DISABLED; }
228 	| IGMPV1		{ v->uv_flags |= VIFF_IGMPV1; }
229 	| NETMASK addrname	{
230 				  u_int32_t subnet, mask;
231 
232 				  mask = $2;
233 				  subnet = v->uv_lcl_addr & mask;
234 				  if (!inet_valid_subnet(subnet, mask))
235 					fatal("Invalid netmask");
236 				  v->uv_subnet = subnet;
237 				  v->uv_subnetmask = mask;
238 				  v->uv_subnetbcast = subnet | ~mask;
239 				}
240 	| NETMASK		{
241 
242 		    warn("Expected address after netmask keyword, ignored");
243 
244 				}
245 	| ALTNET addrmask	{
246 
247 		    struct phaddr *ph;
248 
249 		    ph = malloc(sizeof(struct phaddr));
250 		    if (ph == NULL)
251 			fatal("out of memory");
252 		    if ($2.mask) {
253 			VAL_TO_MASK(ph->pa_subnetmask, $2.mask);
254 		    } else
255 			ph->pa_subnetmask = v->uv_subnetmask;
256 		    ph->pa_subnet = $2.addr & ph->pa_subnetmask;
257 		    ph->pa_subnetbcast = ph->pa_subnet | ~ph->pa_subnetmask;
258 		    if ($2.addr & ~ph->pa_subnetmask)
259 			warn("Extra subnet %s/%d has host bits set",
260 				inet_fmt($2.addr,s1), $2.mask);
261 		    ph->pa_next = v->uv_addrs;
262 		    v->uv_addrs = ph;
263 
264 				}
265 	| ALTNET		{
266 
267 		    warn("Expected address after altnet keyword, ignored");
268 
269 				}
270 	;
271 
272 mod	: THRESHOLD NUMBER	{ if ($2 < 1 || $2 > 255)
273 				    fatal("Invalid threshold %d",$2);
274 				  v->uv_threshold = $2;
275 				}
276 	| THRESHOLD		{
277 
278 		    warn("Expected number after threshold keyword, ignored");
279 
280 				}
281 	| METRIC NUMBER		{ if ($2 < 1 || $2 > UNREACHABLE)
282 				    fatal("Invalid metric %d",$2);
283 				  v->uv_metric = $2;
284 				}
285 	| METRIC		{
286 
287 		    warn("Expected number after metric keyword, ignored");
288 
289 				}
290 	| RATE_LIMIT NUMBER	{ if ($2 > MAX_RATE_LIMIT)
291 				    fatal("Invalid rate_limit %d",$2);
292 				  v->uv_rate_limit = $2;
293 				}
294 	| RATE_LIMIT		{
295 
296 		    warn("Expected number after rate_limit keyword, ignored");
297 
298 				}
299 	| BOUNDARY bound	{
300 
301 		    struct vif_acl *v_acl;
302 
303 		    v_acl = malloc(sizeof(struct vif_acl));
304 		    if (v_acl == NULL)
305 			fatal("out of memory");
306 		    VAL_TO_MASK(v_acl->acl_mask, $2.mask);
307 		    v_acl->acl_addr = $2.addr & v_acl->acl_mask;
308 		    if ($2.addr & ~v_acl->acl_mask)
309 			warn("Boundary spec %s/%d has host bits set",
310 				inet_fmt($2.addr,s1),$2.mask);
311 		    v_acl->acl_next = v->uv_acl;
312 		    v->uv_acl = v_acl;
313 
314 				}
315 	| BOUNDARY		{
316 
317 		warn("Expected boundary spec after boundary keyword, ignored");
318 
319 				}
320 	;
321 
322 interface	: ADDR		{ $$ = $1; }
323 	| STRING		{
324 				  $$ = valid_if($1);
325 				  if ($$ == 0)
326 					fatal("Invalid interface name %s",$1);
327 				}
328 	;
329 
330 addrname	: ADDR		{ $$ = $1; }
331 	| STRING		{ struct hostent *hp;
332 
333 				  if ((hp = gethostbyname($1)) == NULL)
334 				    fatal("No such host %s", $1);
335 
336 				  if (hp->h_addr_list[1])
337 				    fatal("Hostname %s does not %s",
338 					$1, "map to a unique address");
339 
340 				  bcopy(hp->h_addr_list[0], &$$,
341 					    hp->h_length);
342 				}
343 
344 bound	: boundary		{ $$ = $1; }
345 	| STRING		{ int i;
346 
347 				  for (i=0; i < numbounds; i++) {
348 				    if (!strcmp(boundlist[i].name, $1)) {
349 					$$ = boundlist[i].bound;
350 					break;
351 				    }
352 				  }
353 				  if (i == numbounds) {
354 				    fatal("Invalid boundary name %s",$1);
355 				  }
356 				}
357 	;
358 
359 boundary	: ADDRMASK	{
360 
361 			if ((ntohl($1.addr) & 0xff000000) != 0xef000000) {
362 			    fatal("Boundaries must be 239.x.x.x, not %s/%d",
363 				inet_fmt($1.addr, s1), $1.mask);
364 			}
365 			$$ = $1;
366 
367 				}
368 	;
369 
370 addrmask	: ADDRMASK	{ $$ = $1; }
371 	| ADDR			{ $$.addr = $1; $$.mask = 0; }
372 	;
373 %%
374 static void
375 fatal(const char *fmt, ...)
376 {
377 	va_list ap;
378 	char buf[200];
379 
380 	va_start(ap, fmt);
381 	vsnprintf(buf, sizeof buf, fmt, ap);
382 	va_end(ap);
383 
384 	logit(LOG_ERR,0,"%s: %s near line %d", configfilename, buf, lineno);
385 }
386 
387 static void
388 warn(const char *fmt, ...)
389 {
390 	va_list ap;
391 	char buf[200];
392 
393 	va_start(ap, fmt);
394 	vsnprintf(buf, sizeof buf, fmt, ap);
395 	va_end(ap);
396 
397 	logit(LOG_WARNING,0,"%s: %s near line %d", configfilename, buf, lineno);
398 }
399 
400 static void
401 yyerror(char *s)
402 {
403 	logit(LOG_ERR, 0, "%s: %s near line %d", configfilename, s, lineno);
404 }
405 
406 static char *
407 next_word(void)
408 {
409 	static char buf[1024];
410 	static char *p=NULL;
411 	extern FILE *f;
412 	char *q;
413 
414 	while (1) {
415 	    if (!p || !*p) {
416 		lineno++;
417 		if (fgets(buf, sizeof(buf), f) == NULL)
418 		    return NULL;
419 		p = buf;
420 	    }
421 	    while (*p && (*p == ' ' || *p == '\t'))	/* skip whitespace */
422 		p++;
423 	    if (*p == '#') {
424 		p = NULL;		/* skip comments */
425 		continue;
426 	    }
427 	    q = p;
428 	    while (*p && *p != ' ' && *p != '\t' && *p != '\n')
429 		p++;		/* find next whitespace */
430 	    *p++ = '\0';	/* null-terminate string */
431 
432 	    if (!*q) {
433 		p = NULL;
434 		continue;	/* if 0-length string, read another line */
435 	    }
436 
437 	    return q;
438 	}
439 }
440 
441 static int
442 yylex(void)
443 {
444 	int n;
445 	u_int32_t addr;
446 	char *q;
447 
448 	if ((q = next_word()) == NULL) {
449 		return 0;
450 	}
451 
452 	if (!strcmp(q,"cache_lifetime"))
453 		return CACHE_LIFETIME;
454 	if (!strcmp(q,"pruning"))
455 		return PRUNING;
456 	if (!strcmp(q,"phyint"))
457 		return PHYINT;
458 	if (!strcmp(q,"tunnel"))
459 		return TUNNEL;
460 	if (!strcmp(q,"disable"))
461 		return DISABLE;
462 	if (!strcmp(q,"metric"))
463 		return METRIC;
464 	if (!strcmp(q,"threshold"))
465 		return THRESHOLD;
466 	if (!strcmp(q,"rate_limit"))
467 		return RATE_LIMIT;
468 	if (!strcmp(q,"srcrt") || !strcmp(q,"sourceroute"))
469 		return SRCRT;
470 	if (!strcmp(q,"boundary"))
471 		return BOUNDARY;
472 	if (!strcmp(q,"netmask"))
473 		return NETMASK;
474 	if (!strcmp(q,"igmpv1"))
475 		return IGMPV1;
476 	if (!strcmp(q,"altnet"))
477 		return ALTNET;
478 	if (!strcmp(q,"name"))
479 		return NAME;
480 	if (!strcmp(q,"on") || !strcmp(q,"yes")) {
481 		yylval.num = 1;
482 		return BOOLEAN;
483 	}
484 	if (!strcmp(q,"off") || !strcmp(q,"no")) {
485 		yylval.num = 0;
486 		return BOOLEAN;
487 	}
488 	if (sscanf(q,"%[.0-9]/%d%c",s1,&n,s2) == 2) {
489 		if ((addr = inet_parse(s1)) != 0xffffffff) {
490 			yylval.addrmask.mask = n;
491 			yylval.addrmask.addr = addr;
492 			return ADDRMASK;
493 		}
494 		/* fall through to returning STRING */
495 	}
496 	if (sscanf(q,"%[.0-9]%c",s1,s2) == 1) {
497 		if ((addr = inet_parse(s1)) != 0xffffffff &&
498 		    inet_valid_host(addr)) {
499 			yylval.addr = addr;
500 			return ADDR;
501 		}
502 	}
503 	if (sscanf(q,"0x%8x%c",&n,s1) == 1) {
504 		yylval.addr = n;
505 		return ADDR;
506 	}
507 	if (sscanf(q,"%d%c",&n,s1) == 1) {
508 		yylval.num = n;
509 		return NUMBER;
510 	}
511 	yylval.ptr = q;
512 	return STRING;
513 }
514 
515 void
516 config_vifs_from_file(void)
517 {
518 	extern FILE *f;
519 
520 	order = 0;
521 	numbounds = 0;
522 	lineno = 0;
523 
524 	if ((f = fopen(configfilename, "r")) == NULL) {
525 	    if (errno != ENOENT)
526 		logit(LOG_ERR, errno, "can't open %s", configfilename);
527 	    return;
528 	}
529 
530 	yyparse();
531 
532 	fclose(f);
533 }
534 
535 static u_int32_t
536 valid_if(char *s)
537 {
538 	register vifi_t vifi;
539 	register struct uvif *v;
540 
541 	for (vifi=0, v=uvifs; vifi<numvifs; vifi++, v++)
542 	    if (!strcmp(v->uv_name, s))
543 		return v->uv_lcl_addr;
544 
545 	return 0;
546 }
547 
548 static const char *
549 ifconfaddr(u_int32_t a)
550 {
551     static char ifname[IFNAMSIZ];
552     struct ifaddrs *ifap, *ifa;
553 
554     if (getifaddrs(&ifap) != 0)
555 	return (NULL);
556 
557     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
558 	    if (ifa->ifa_addr != NULL &&
559 		ifa->ifa_addr->sa_family == AF_INET &&
560 		((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr == a) {
561 		strlcpy(ifname, ifa->ifa_name, sizeof(ifname));
562 		freeifaddrs(ifap);
563 		return (ifname);
564 	    }
565     }
566     freeifaddrs(ifap);
567     return (0);
568 }
569