xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/gen.c (revision 45ede40b2394db7967e59f19288fae9b62efd4aa)
1 /*
2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
9  * Copyright (c) 1996-1999 by Internet Software Consortium.
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 ISC DISCLAIMS ALL WARRANTIES
16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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
21  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22  */
23 
24 /*! \file
25  * \brief
26  * this is the top level dispatcher
27  *
28  * The dispatcher is implemented as an accessor class; it is an
29  * accessor class that calls other accessor classes, as controlled by a
30  * configuration file.
31  *
32  * A big difference between this accessor class and others is that the
33  * map class initializers are NULL, and the map classes are already
34  * filled in with method functions that will do the right thing.
35  */
36 
37 /* Imports */
38 
39 #include "port_before.h"
40 
41 #include <isc/assertions.h>
42 #include <ctype.h>
43 #include <errno.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 #include <sys/types.h>
49 #include <netinet/in.h>
50 #include <arpa/nameser.h>
51 #include <resolv.h>
52 
53 #include <isc/memcluster.h>
54 #include <irs.h>
55 
56 #include "port_after.h"
57 
58 #include "irs_p.h"
59 #include "gen_p.h"
60 
61 #ifdef SUNW_HOSTS_FALLBACK
62 extern int __res_no_hosts_fallback(void);
63 #endif /* SUNW_HOSTS_FALLBACK */
64 
65 /* Definitions */
66 
67 struct nameval {
68 	const char *	name;
69 	int		val;
70 };
71 
72 static const struct nameval acc_names[irs_nacc+1] = {
73 	{ "local", irs_lcl },
74 	{ "dns", irs_dns },
75 	{ "nis", irs_nis },
76 	{ "irp", irs_irp },
77 	{ NULL, irs_nacc }
78 };
79 
80 typedef struct irs_acc *(*accinit) __P((const char *options));
81 
82 static const accinit accs[irs_nacc+1] = {
83 	irs_lcl_acc,
84 	irs_dns_acc,
85 #ifdef WANT_IRS_NIS
86 	irs_nis_acc,
87 #else
88 	NULL,
89 #endif
90 	irs_irp_acc,
91 	NULL
92 };
93 
94 static const struct nameval map_names[irs_nmap+1] = {
95 	{ "group", irs_gr },
96 	{ "passwd", irs_pw },
97 	{ "services", irs_sv },
98 	{ "protocols", irs_pr },
99 	{ "hosts", irs_ho },
100 	{ "networks", irs_nw },
101 	{ "netgroup", irs_ng },
102 	{ NULL, irs_nmap }
103 };
104 
105 static const struct nameval option_names[] = {
106 	{ "merge", IRS_MERGE },
107 	{ "continue", IRS_CONTINUE },
108 	{ NULL, 0 }
109 };
110 
111 /* Forward */
112 
113 static void		gen_close(struct irs_acc *);
114 static struct __res_state * gen_res_get(struct irs_acc *);
115 static void		gen_res_set(struct irs_acc *, struct __res_state *,
116 				    void (*)(void *));
117 static int		find_name(const char *, const struct nameval nv[]);
118 static void 		init_map_rules(struct gen_p *, const char *conf_file);
119 static struct irs_rule *release_rule(struct irs_rule *);
120 static int		add_rule(struct gen_p *,
121 				 enum irs_map_id, enum irs_acc_id,
122 				 const char *);
123 
124 /* Public */
125 
126 struct irs_acc *
127 irs_gen_acc(const char *options, const char *conf_file) {
128 	struct irs_acc *acc;
129 	struct gen_p *irs;
130 
131 	if (!(acc = memget(sizeof *acc))) {
132 		errno = ENOMEM;
133 		return (NULL);
134 	}
135 	memset(acc, 0x5e, sizeof *acc);
136 	if (!(irs = memget(sizeof *irs))) {
137 		errno = ENOMEM;
138 		memput(acc, sizeof *acc);
139 		return (NULL);
140 	}
141 	memset(irs, 0x5e, sizeof *irs);
142 	irs->options = strdup(options);
143 	irs->res = NULL;
144 	irs->free_res = NULL;
145 	memset(irs->accessors, 0, sizeof irs->accessors);
146 	memset(irs->map_rules, 0, sizeof irs->map_rules);
147 	init_map_rules(irs, conf_file);
148 	acc->private = irs;
149 #ifdef WANT_IRS_GR
150 	acc->gr_map = irs_gen_gr;
151 #else
152 	acc->gr_map = NULL;
153 #endif
154 #ifdef WANT_IRS_PW
155 	acc->pw_map = irs_gen_pw;
156 #else
157 	acc->pw_map = NULL;
158 #endif
159 	acc->sv_map = irs_gen_sv;
160 	acc->pr_map = irs_gen_pr;
161 	acc->ho_map = irs_gen_ho;
162 	acc->nw_map = irs_gen_nw;
163 	acc->ng_map = irs_gen_ng;
164 	acc->res_get = gen_res_get;
165 	acc->res_set = gen_res_set;
166 	acc->close = gen_close;
167 	return (acc);
168 }
169 
170 /* Methods */
171 
172 static struct __res_state *
173 gen_res_get(struct irs_acc *this) {
174 	struct gen_p *irs = (struct gen_p *)this->private;
175 
176 	if (irs->res == NULL) {
177 		struct __res_state *res;
178 		res = (struct __res_state *)malloc(sizeof *res);
179 		if (res == NULL)
180 			return (NULL);
181 		memset(res, 0, sizeof *res);
182 		gen_res_set(this, res, free);
183 	}
184 
185 	if (((irs->res->options & RES_INIT) == 0U) && res_ninit(irs->res) < 0)
186 		return (NULL);
187 
188 	return (irs->res);
189 }
190 
191 static void
192 gen_res_set(struct irs_acc *this, struct __res_state *res,
193 	    void (*free_res)(void *)) {
194 	struct gen_p *irs = (struct gen_p *)this->private;
195 #if 0
196 	struct irs_rule *rule;
197 	struct irs_ho *ho;
198 	struct irs_nw *nw;
199 #endif
200 
201 	if (irs->res && irs->free_res) {
202 		res_nclose(irs->res);
203 		(*irs->free_res)(irs->res);
204 	}
205 
206 	irs->res = res;
207 	irs->free_res = free_res;
208 
209 #if 0
210 	for (rule = irs->map_rules[irs_ho]; rule; rule = rule->next) {
211                 ho = rule->inst->ho;
212 
213                 (*ho->res_set)(ho, res, NULL);
214 	}
215 	for (rule = irs->map_rules[irs_nw]; rule; rule = rule->next) {
216                 nw = rule->inst->nw;
217 
218                 (*nw->res_set)(nw, res, NULL);
219 	}
220 #endif
221 }
222 
223 static void
224 gen_close(struct irs_acc *this) {
225 	struct gen_p *irs = (struct gen_p *)this->private;
226 	int n;
227 
228 	/* Search rules. */
229 	for (n = 0; n < irs_nmap; n++)
230 		while (irs->map_rules[n] != NULL)
231 			irs->map_rules[n] = release_rule(irs->map_rules[n]);
232 
233 	/* Access methods. */
234 	for (n = 0; n < irs_nacc; n++) {
235 		/* Map objects. */
236 		if (irs->accessors[n].gr != NULL)
237 			(*irs->accessors[n].gr->close)(irs->accessors[n].gr);
238 		if (irs->accessors[n].pw != NULL)
239 			(*irs->accessors[n].pw->close)(irs->accessors[n].pw);
240 		if (irs->accessors[n].sv != NULL)
241 			(*irs->accessors[n].sv->close)(irs->accessors[n].sv);
242 		if (irs->accessors[n].pr != NULL)
243 			(*irs->accessors[n].pr->close)(irs->accessors[n].pr);
244 		if (irs->accessors[n].ho != NULL)
245 			(*irs->accessors[n].ho->close)(irs->accessors[n].ho);
246 		if (irs->accessors[n].nw != NULL)
247 			(*irs->accessors[n].nw->close)(irs->accessors[n].nw);
248 		if (irs->accessors[n].ng != NULL)
249 			(*irs->accessors[n].ng->close)(irs->accessors[n].ng);
250 		/* Enclosing accessor. */
251 		if (irs->accessors[n].acc != NULL)
252 			(*irs->accessors[n].acc->close)(irs->accessors[n].acc);
253 	}
254 
255 	/* The options string was strdup'd. */
256 	free((void*)irs->options);
257 
258 	if (irs->res && irs->free_res)
259 		(*irs->free_res)(irs->res);
260 
261 	/* The private data container. */
262 	memput(irs, sizeof *irs);
263 
264 	/* The object. */
265 	memput(this, sizeof *this);
266 }
267 
268 /* Private */
269 
270 static int
271 find_name(const char *name, const struct nameval names[]) {
272 	int n;
273 
274 	for (n = 0; names[n].name != NULL; n++)
275 		if (strcmp(name, names[n].name) == 0)
276 			return (names[n].val);
277 	return (-1);
278 }
279 
280 static struct irs_rule *
281 release_rule(struct irs_rule *rule) {
282 	struct irs_rule *next = rule->next;
283 
284 	memput(rule, sizeof *rule);
285 	return (next);
286 }
287 
288 static int
289 add_rule(struct gen_p *irs,
290 	 enum irs_map_id map, enum irs_acc_id acc,
291 	 const char *options)
292 {
293 	struct irs_rule **rules, *last, *tmp, *new;
294 	struct irs_inst *inst;
295 	const char *cp;
296 	int n;
297 
298 #ifndef WANT_IRS_GR
299 	if (map == irs_gr)
300 		return (-1);
301 #endif
302 #ifndef WANT_IRS_PW
303 	if (map == irs_pw)
304 		return (-1);
305 #endif
306 #ifndef WANT_IRS_NIS
307 	if (acc == irs_nis)
308 		return (-1);
309 #endif
310 	new = memget(sizeof *new);
311 	if (new == NULL)
312 		return (-1);
313 	memset(new, 0x5e, sizeof *new);
314 	new->next = NULL;
315 
316 	new->inst = &irs->accessors[acc];
317 
318 	new->flags = 0;
319 	cp = options;
320 	while (cp && *cp) {
321 		char option[50], *next;
322 
323 		next = strchr(cp, ',');
324 		if (next)
325 			n = next++ - cp;
326 		else
327 			n = strlen(cp);
328 		if ((size_t)n > sizeof option - 1)
329 			n = sizeof option - 1;
330 		strncpy(option, cp, n);
331 		option[n] = '\0';
332 
333 		n = find_name(option, option_names);
334 		if (n >= 0)
335 			new->flags |= n;
336 
337 		cp = next;
338 	}
339 
340 	rules = &irs->map_rules[map];
341 	for (last = NULL, tmp = *rules;
342 	     tmp != NULL;
343 	     last = tmp, tmp = tmp->next)
344 		(void)NULL;
345 	if (last == NULL)
346 		*rules = new;
347 	else
348 		last->next = new;
349 
350 	/* Try to instantiate map accessors for this if necessary & approp. */
351 	inst = &irs->accessors[acc];
352 	if (inst->acc == NULL && accs[acc] != NULL)
353 		inst->acc = (*accs[acc])(irs->options);
354 	if (inst->acc != NULL) {
355 		if (inst->gr == NULL && inst->acc->gr_map != NULL)
356 			inst->gr = (*inst->acc->gr_map)(inst->acc);
357 		if (inst->pw == NULL && inst->acc->pw_map != NULL)
358 			inst->pw = (*inst->acc->pw_map)(inst->acc);
359 		if (inst->sv == NULL && inst->acc->sv_map != NULL)
360 			inst->sv = (*inst->acc->sv_map)(inst->acc);
361 		if (inst->pr == NULL && inst->acc->pr_map != NULL)
362 			inst->pr = (*inst->acc->pr_map)(inst->acc);
363 		if (inst->ho == NULL && inst->acc->ho_map != NULL)
364 			inst->ho = (*inst->acc->ho_map)(inst->acc);
365 		if (inst->nw == NULL && inst->acc->nw_map != NULL)
366 			inst->nw = (*inst->acc->nw_map)(inst->acc);
367 		if (inst->ng == NULL && inst->acc->ng_map != NULL)
368 			inst->ng = (*inst->acc->ng_map)(inst->acc);
369 	}
370 
371 	return (0);
372 }
373 
374 static void
375 default_map_rules(struct gen_p *irs) {
376 	/* Install time honoured and proved BSD style rules as default. */
377 	add_rule(irs, irs_gr, irs_lcl, "");
378 	add_rule(irs, irs_pw, irs_lcl, "");
379 	add_rule(irs, irs_sv, irs_lcl, "");
380 	add_rule(irs, irs_pr, irs_lcl, "");
381 #ifdef SUNW_HOSTS_FALLBACK
382 	if (__res_no_hosts_fallback())
383 		add_rule(irs, irs_ho, irs_dns, "");
384 	else {
385 		add_rule(irs, irs_ho, irs_dns, "continue");
386 		add_rule(irs, irs_ho, irs_lcl, "");
387 	}
388 #else  /* SUNW_HOSTS_FALLBACK */
389 	add_rule(irs, irs_ho, irs_dns, "continue");
390 	add_rule(irs, irs_ho, irs_lcl, "");
391 #endif /* SUNW_HOSTS_FALLBACK */
392 	add_rule(irs, irs_nw, irs_dns, "continue");
393 	add_rule(irs, irs_nw, irs_lcl, "");
394 	add_rule(irs, irs_ng, irs_lcl, "");
395 }
396 
397 static void
398 init_map_rules(struct gen_p *irs, const char *conf_file) {
399 	char line[1024], pattern[40], mapname[20], accname[20], options[100];
400 	FILE *conf;
401 
402 #ifdef SUNW_HOSTS_FALLBACK
403 	if (__res_no_hosts_fallback()) {
404 		default_map_rules(irs);
405 		return;
406 	}
407 #endif /* SUNW_HOSTS_FALLBACK */
408 
409 	if (conf_file == NULL)
410 		conf_file = _PATH_IRS_CONF ;
411 
412 	/* A conf file of "" means compiled in defaults. Irpd wants this */
413 	if (conf_file[0] == '\0' || (conf = fopen(conf_file, "r")) == NULL) {
414 		default_map_rules(irs);
415 		return;
416 	}
417 	(void) sprintf(pattern, "%%%lus %%%lus %%%lus\n",
418 		       (unsigned long)sizeof mapname,
419 		       (unsigned long)sizeof accname,
420 		       (unsigned long)sizeof options);
421 	while (fgets(line, sizeof line, conf)) {
422 		enum irs_map_id map;
423 		enum irs_acc_id acc;
424 		char *tmp;
425 		int n;
426 
427 		for (tmp = line;
428 		     isascii((unsigned char)*tmp) &&
429 		     isspace((unsigned char)*tmp);
430 		     tmp++)
431 			(void)NULL;
432 		if (*tmp == '#' || *tmp == '\n' || *tmp == '\0')
433 			continue;
434 		n = sscanf(tmp, pattern, mapname, accname, options);
435 		if (n < 2)
436 			continue;
437 		if (n < 3)
438 			options[0] = '\0';
439 
440 		n = find_name(mapname, map_names);
441 		INSIST(n < irs_nmap);
442 		if (n < 0)
443 			continue;
444 		map = (enum irs_map_id) n;
445 
446 		n = find_name(accname, acc_names);
447 		INSIST(n < irs_nacc);
448 		if (n < 0)
449 			continue;
450 		acc = (enum irs_acc_id) n;
451 
452 		add_rule(irs, map, acc, options);
453 	}
454 	fclose(conf);
455 }
456