modules/ssl/ssl_expr_parse.y

/*                      _             _ 
**  _ __ ___   ___   __| |    ___ ___| |  
** | '_ ` _ \ / _ \ / _` |   / __/ __| |  
** | | | | | | (_) | (_| |   \__ \__ \ | mod_ssl - Apache Interface to OpenSSL
** |_| |_| |_|\___/ \__,_|___|___/___/_| http://www.modssl.org/
**                      |_____|         
**  ssl_expr_parse.y
**  Expression LR(1) Parser
*/

/* ====================================================================
 * Copyright (c) 1998-2001 Ralf S. Engelschall. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by 
 *     Ralf S. Engelschall <rse@engelschall.com> for use in the
 *     mod_ssl project (http://www.modssl.org/)."
 *
 * 4. The names "mod_ssl" must not be used to endorse or promote
 *    products derived from this software without prior written
 *    permission. For written permission, please contact
 *    rse@engelschall.com.
 *
 * 5. Products derived from this software may not be called "mod_ssl"
 *    nor may "mod_ssl" appear in their names without prior
 *    written permission of Ralf S. Engelschall.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by 
 *     Ralf S. Engelschall <rse@engelschall.com> for use in the
 *     mod_ssl project (http://www.modssl.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY RALF S. ENGELSCHALL ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL RALF S. ENGELSCHALL OR
 * HIS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 */

                             /* ``What you see is all you get.''
							              -- Brian Kernighan      */

/*  _________________________________________________________________
**
**  Expression Parser
**  _________________________________________________________________
*/

%{
#include "mod_ssl.h"
%}

%union {
    char     *cpVal;
    ssl_expr *exVal;
}

%token  T_TRUE
%token  T_FALSE

%token  <cpVal> T_DIGIT
%token  <cpVal> T_ID
%token  <cpVal> T_STRING
%token  <cpVal> T_REGEX
%token  <cpVal> T_REGEX_I

%token  T_FUNC_FILE

%token  T_OP_EQ
%token  T_OP_NE
%token  T_OP_LT
%token  T_OP_LE
%token  T_OP_GT
%token  T_OP_GE
%token  T_OP_REG
%token  T_OP_NRE
%token  T_OP_IN

%token  T_OP_OR
%token  T_OP_AND
%token  T_OP_NOT

%left   T_OP_OR
%left   T_OP_AND
%left   T_OP_NOT

%type   <exVal>   expr
%type   <exVal>   comparison
%type   <exVal>   funccall
%type   <exVal>   regex
%type   <exVal>   words
%type   <exVal>   word

%%

root      : expr                         { ssl_expr_info.expr = $1; }
          ;

expr      : T_TRUE                       { $$ = ssl_expr_make(op_True,  NULL, NULL); }
          | T_FALSE                      { $$ = ssl_expr_make(op_False, NULL, NULL); }
          | T_OP_NOT expr                { $$ = ssl_expr_make(op_Not,   $2,   NULL); }
          | expr T_OP_OR expr            { $$ = ssl_expr_make(op_Or,    $1,   $3);   }
          | expr T_OP_AND expr           { $$ = ssl_expr_make(op_And,   $1,   $3);   }
          | comparison                   { $$ = ssl_expr_make(op_Comp,  $1,   NULL); }
          | '(' expr ')'                 { $$ = $2; }
          ;

comparison: word T_OP_EQ word            { $$ = ssl_expr_make(op_EQ,  $1, $3); }
          | word T_OP_NE word            { $$ = ssl_expr_make(op_NE,  $1, $3); }
          | word T_OP_LT word            { $$ = ssl_expr_make(op_LT,  $1, $3); }
          | word T_OP_LE word            { $$ = ssl_expr_make(op_LE,  $1, $3); }
          | word T_OP_GT word            { $$ = ssl_expr_make(op_GT,  $1, $3); }
          | word T_OP_GE word            { $$ = ssl_expr_make(op_GE,  $1, $3); }
          | word T_OP_IN '{' words '}'   { $$ = ssl_expr_make(op_IN,  $1, $4); }
          | word T_OP_REG regex          { $$ = ssl_expr_make(op_REG, $1, $3); }
          | word T_OP_NRE regex          { $$ = ssl_expr_make(op_NRE, $1, $3); }
          ;

words     : word                         { $$ = ssl_expr_make(op_ListElement, $1, NULL); }
          | words ',' word               { $$ = ssl_expr_make(op_ListElement, $3, $1);   }
          ;

word      : T_DIGIT                      { $$ = ssl_expr_make(op_Digit,  $1, NULL); }
          | T_STRING                     { $$ = ssl_expr_make(op_String, $1, NULL); }
          | '%' '{' T_ID '}'             { $$ = ssl_expr_make(op_Var,    $3, NULL); }
          | funccall                     { $$ = $1; }
          ;

regex     : T_REGEX { 
                regex_t *regex;
                if ((regex = ap_pregcomp(ssl_expr_info.pool, $1, 
                                         REG_EXTENDED|REG_NOSUB)) == NULL) {
                    ssl_expr_error = "Failed to compile regular expression";
                    YYERROR;
                    regex = NULL;
                }
                $$ = ssl_expr_make(op_Regex, regex, NULL);
            }
          | T_REGEX_I {
                regex_t *regex;
                if ((regex = ap_pregcomp(ssl_expr_info.pool, $1, 
                                         REG_EXTENDED|REG_NOSUB|REG_ICASE)) == NULL) {
                    ssl_expr_error = "Failed to compile regular expression";
                    YYERROR;
                    regex = NULL;
                }
                $$ = ssl_expr_make(op_Regex, regex, NULL);
            }
          ;

funccall  : T_FUNC_FILE '(' T_STRING ')' { 
               ssl_expr *args = ssl_expr_make(op_ListElement, $3, NULL);
               $$ = ssl_expr_make(op_Func, "file", args);
            }
          ;

%%

int yyerror(char *s)
{
    ssl_expr_error = s;
    return 2;
}