lib/libipsec/policy_parse.y

   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