xref: /freebsd/lib/libipsec/policy_parse.y (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*	$KAME: policy_parse.y,v 1.14 2003/06/27 03:39:20 itojun Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * IN/OUT bound policy configuration take place such below:
34  *	in <policy>
35  *	out <policy>
36  *
37  * <policy> is one of following:
38  *	"discard", "none", "ipsec <requests>", "entrust", "bypass",
39  *
40  * The following requests are accepted as <requests>:
41  *
42  *	protocol/mode/src-dst/level
43  *	protocol/mode/src-dst		parsed as protocol/mode/src-dst/default
44  *	protocol/mode/src-dst/		parsed as protocol/mode/src-dst/default
45  *	protocol/transport		parsed as protocol/mode/any-any/default
46  *	protocol/transport//level	parsed as protocol/mode/any-any/level
47  *
48  * You can concatenate these requests with either ' '(single space) or '\n'.
49  */
50 
51 %{
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54 
55 #include <sys/types.h>
56 #include <sys/param.h>
57 #include <sys/socket.h>
58 
59 #include <netinet/in.h>
60 #include <netipsec/ipsec.h>
61 
62 #include <stdlib.h>
63 #include <stdio.h>
64 #include <string.h>
65 #include <netdb.h>
66 
67 #include "ipsec_strerror.h"
68 
69 #define ATOX(c) \
70   (isdigit(c) ? (c - '0') : (isupper(c) ? (c - 'A' + 10) : (c - 'a' + 10) ))
71 
72 static caddr_t pbuf = NULL;		/* sadb_x_policy buffer */
73 static int tlen = 0;			/* total length of pbuf */
74 static int offset = 0;			/* offset of pbuf */
75 static int p_dir, p_type, p_protocol, p_mode, p_level, p_reqid;
76 static struct sockaddr *p_src = NULL;
77 static struct sockaddr *p_dst = NULL;
78 
79 struct _val;
80 extern void yyerror(char *msg);
81 static struct sockaddr *parse_sockaddr(struct _val *buf);
82 static int rule_check(void);
83 static int init_x_policy(void);
84 static int set_x_request(struct sockaddr *src, struct sockaddr *dst);
85 static int set_sockaddr(struct sockaddr *addr);
86 static void policy_parse_request_init(void);
87 static caddr_t policy_parse(char *msg, int msglen);
88 
89 extern void __policy__strbuffer__init__(char *msg);
90 extern void __policy__strbuffer__free__(void);
91 extern int yylex(void);
92 
93 extern char *__libipsecyytext;	/*XXX*/
94 
95 %}
96 
97 %union {
98 	u_int num;
99 	struct _val {
100 		int len;
101 		char *buf;
102 	} val;
103 }
104 
105 %token DIR ACTION PROTOCOL MODE LEVEL LEVEL_SPECIFY
106 %token IPADDRESS
107 %token ME ANY
108 %token SLASH HYPHEN
109 %type <num> DIR ACTION PROTOCOL MODE LEVEL
110 %type <val> IPADDRESS LEVEL_SPECIFY
111 
112 %%
113 policy_spec
114 	:	DIR ACTION
115 		{
116 			p_dir = $1;
117 			p_type = $2;
118 
119 			if (init_x_policy())
120 				return -1;
121 		}
122 		rules
123 	|	DIR
124 		{
125 			p_dir = $1;
126 			p_type = 0;	/* ignored it by kernel */
127 
128 			if (init_x_policy())
129 				return -1;
130 		}
131 	;
132 
133 rules
134 	:	/*NOTHING*/
135 	|	rules rule {
136 			if (rule_check() < 0)
137 				return -1;
138 
139 			if (set_x_request(p_src, p_dst) < 0)
140 				return -1;
141 
142 			policy_parse_request_init();
143 		}
144 	;
145 
146 rule
147 	:	protocol SLASH mode SLASH addresses SLASH level
148 	|	protocol SLASH mode SLASH addresses SLASH
149 	|	protocol SLASH mode SLASH addresses
150 	|	protocol SLASH mode SLASH
151 	|	protocol SLASH mode SLASH SLASH level
152 	|	protocol SLASH mode
153 	|	protocol SLASH {
154 			__ipsec_errcode = EIPSEC_FEW_ARGUMENTS;
155 			return -1;
156 		}
157 	|	protocol {
158 			__ipsec_errcode = EIPSEC_FEW_ARGUMENTS;
159 			return -1;
160 		}
161 	;
162 
163 protocol
164 	:	PROTOCOL { p_protocol = $1; }
165 	;
166 
167 mode
168 	:	MODE { p_mode = $1; }
169 	;
170 
171 level
172 	:	LEVEL {
173 			p_level = $1;
174 			p_reqid = 0;
175 		}
176 	|	LEVEL_SPECIFY {
177 			p_level = IPSEC_LEVEL_UNIQUE;
178 			p_reqid = atol($1.buf);	/* atol() is good. */
179 		}
180 	;
181 
182 addresses
183 	:	IPADDRESS {
184 			p_src = parse_sockaddr(&$1);
185 			if (p_src == NULL)
186 				return -1;
187 		}
188 		HYPHEN
189 		IPADDRESS {
190 			p_dst = parse_sockaddr(&$4);
191 			if (p_dst == NULL)
192 				return -1;
193 		}
194 	|	ME HYPHEN ANY {
195 			if (p_dir != IPSEC_DIR_OUTBOUND) {
196 				__ipsec_errcode = EIPSEC_INVAL_DIR;
197 				return -1;
198 			}
199 		}
200 	|	ANY HYPHEN ME {
201 			if (p_dir != IPSEC_DIR_INBOUND) {
202 				__ipsec_errcode = EIPSEC_INVAL_DIR;
203 				return -1;
204 			}
205 		}
206 		/*
207 	|	ME HYPHEN ME
208 		*/
209 	;
210 
211 %%
212 
213 void
214 yyerror(msg)
215 	char *msg;
216 {
217 	fprintf(stderr, "libipsec: %s while parsing \"%s\"\n",
218 		msg, __libipsecyytext);
219 
220 	return;
221 }
222 
223 static struct sockaddr *
224 parse_sockaddr(buf)
225 	struct _val *buf;
226 {
227 	struct addrinfo hints, *res;
228 	char *serv = NULL;
229 	int error;
230 	struct sockaddr *newaddr = NULL;
231 
232 	memset(&hints, 0, sizeof(hints));
233 	hints.ai_family = PF_UNSPEC;
234 	hints.ai_flags = AI_NUMERICHOST;
235 	error = getaddrinfo(buf->buf, serv, &hints, &res);
236 	if (error != 0) {
237 		yyerror("invalid IP address");
238 		__ipsec_set_strerror(gai_strerror(error));
239 		return NULL;
240 	}
241 
242 	if (res->ai_addr == NULL) {
243 		yyerror("invalid IP address");
244 		__ipsec_set_strerror(gai_strerror(error));
245 		return NULL;
246 	}
247 
248 	newaddr = malloc(res->ai_addr->sa_len);
249 	if (newaddr == NULL) {
250 		__ipsec_errcode = EIPSEC_NO_BUFS;
251 		freeaddrinfo(res);
252 		return NULL;
253 	}
254 	memcpy(newaddr, res->ai_addr, res->ai_addr->sa_len);
255 
256 	freeaddrinfo(res);
257 
258 	__ipsec_errcode = EIPSEC_NO_ERROR;
259 	return newaddr;
260 }
261 
262 static int
263 rule_check()
264 {
265 	if (p_type == IPSEC_POLICY_IPSEC) {
266 		if (p_protocol == IPPROTO_IP) {
267 			__ipsec_errcode = EIPSEC_NO_PROTO;
268 			return -1;
269 		}
270 
271 		if (p_mode != IPSEC_MODE_TRANSPORT
272 		 && p_mode != IPSEC_MODE_TUNNEL) {
273 			__ipsec_errcode = EIPSEC_INVAL_MODE;
274 			return -1;
275 		}
276 
277 		if (p_src == NULL && p_dst == NULL) {
278 			 if (p_mode != IPSEC_MODE_TRANSPORT) {
279 				__ipsec_errcode = EIPSEC_INVAL_ADDRESS;
280 				return -1;
281 			}
282 		}
283 		else if (p_src->sa_family != p_dst->sa_family) {
284 			__ipsec_errcode = EIPSEC_FAMILY_MISMATCH;
285 			return -1;
286 		}
287 	}
288 
289 	__ipsec_errcode = EIPSEC_NO_ERROR;
290 	return 0;
291 }
292 
293 static int
294 init_x_policy()
295 {
296 	struct sadb_x_policy *p;
297 
298 	tlen = sizeof(struct sadb_x_policy);
299 
300 	pbuf = malloc(tlen);
301 	if (pbuf == NULL) {
302 		__ipsec_errcode = EIPSEC_NO_BUFS;
303 		return -1;
304 	}
305 	memset(pbuf, 0, tlen);
306 	p = (struct sadb_x_policy *)pbuf;
307 	p->sadb_x_policy_len = 0;	/* must update later */
308 	p->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
309 	p->sadb_x_policy_type = p_type;
310 	p->sadb_x_policy_dir = p_dir;
311 	p->sadb_x_policy_id = 0;
312 
313 	offset = tlen;
314 
315 	__ipsec_errcode = EIPSEC_NO_ERROR;
316 	return 0;
317 }
318 
319 static int
320 set_x_request(src, dst)
321 	struct sockaddr *src, *dst;
322 {
323 	struct sadb_x_ipsecrequest *p;
324 	int reqlen;
325 
326 	reqlen = sizeof(*p)
327 		+ (src ? src->sa_len : 0)
328 		+ (dst ? dst->sa_len : 0);
329 	tlen += reqlen;		/* increment to total length */
330 
331 	pbuf = realloc(pbuf, tlen);
332 	if (pbuf == NULL) {
333 		__ipsec_errcode = EIPSEC_NO_BUFS;
334 		return -1;
335 	}
336 	p = (struct sadb_x_ipsecrequest *)&pbuf[offset];
337 	p->sadb_x_ipsecrequest_len = reqlen;
338 	p->sadb_x_ipsecrequest_proto = p_protocol;
339 	p->sadb_x_ipsecrequest_mode = p_mode;
340 	p->sadb_x_ipsecrequest_level = p_level;
341 	p->sadb_x_ipsecrequest_reqid = p_reqid;
342 	offset += sizeof(*p);
343 
344 	if (set_sockaddr(src) || set_sockaddr(dst))
345 		return -1;
346 
347 	__ipsec_errcode = EIPSEC_NO_ERROR;
348 	return 0;
349 }
350 
351 static int
352 set_sockaddr(addr)
353 	struct sockaddr *addr;
354 {
355 	if (addr == NULL) {
356 		__ipsec_errcode = EIPSEC_NO_ERROR;
357 		return 0;
358 	}
359 
360 	/* tlen has already incremented */
361 
362 	memcpy(&pbuf[offset], addr, addr->sa_len);
363 
364 	offset += addr->sa_len;
365 
366 	__ipsec_errcode = EIPSEC_NO_ERROR;
367 	return 0;
368 }
369 
370 static void
371 policy_parse_request_init()
372 {
373 	p_protocol = IPPROTO_IP;
374 	p_mode = IPSEC_MODE_ANY;
375 	p_level = IPSEC_LEVEL_DEFAULT;
376 	p_reqid = 0;
377 	if (p_src != NULL) {
378 		free(p_src);
379 		p_src = NULL;
380 	}
381 	if (p_dst != NULL) {
382 		free(p_dst);
383 		p_dst = NULL;
384 	}
385 
386 	return;
387 }
388 
389 static caddr_t
390 policy_parse(msg, msglen)
391 	char *msg;
392 	int msglen;
393 {
394 	int error;
395 	pbuf = NULL;
396 	tlen = 0;
397 
398 	/* initialize */
399 	p_dir = IPSEC_DIR_INVALID;
400 	p_type = IPSEC_POLICY_DISCARD;
401 	policy_parse_request_init();
402 	__policy__strbuffer__init__(msg);
403 
404 	error = yyparse();	/* it must be set errcode. */
405 	__policy__strbuffer__free__();
406 
407 	if (error) {
408 		if (pbuf != NULL)
409 			free(pbuf);
410 		return NULL;
411 	}
412 
413 	/* update total length */
414 	((struct sadb_x_policy *)pbuf)->sadb_x_policy_len = PFKEY_UNIT64(tlen);
415 
416 	__ipsec_errcode = EIPSEC_NO_ERROR;
417 
418 	return pbuf;
419 }
420 
421 caddr_t
422 ipsec_set_policy(msg, msglen)
423 	char *msg;
424 	int msglen;
425 {
426 	caddr_t policy;
427 
428 	policy = policy_parse(msg, msglen);
429 	if (policy == NULL) {
430 		if (__ipsec_errcode == EIPSEC_NO_ERROR)
431 			__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
432 		return NULL;
433 	}
434 
435 	__ipsec_errcode = EIPSEC_NO_ERROR;
436 	return policy;
437 }
438 
439