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* Software License Agreement (BSD License)                                                               *
* Author: Sebastien Decugis <sdecugis@nict.go.jp>							 *
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/* Yacc extension's configuration parser.
 * The configuration file consists in a list of two or more:
 * serv = "a.server.diameter.id";
 */

/* For development only : */
%debug 
%error-verbose

/* The parser receives the configuration file filename as parameter */
%parse-param {char * conffile}

/* Keep track of location */
%locations 
%pure-parser

%{
#include "rtun.h"
#include "rtun_conf.tab.h"	/* bison is not smart enough to define the YYLTYPE before including this code, so... */

/* Forward declaration */
int yyparse(char * conffile);

/* Parse the configuration file */
int rtun_conf_handle(char * conffile)
{
	extern FILE * rtun_confin;
	int ret;
	
	TRACE_ENTRY("%p", conffile);
	
	TRACE_DEBUG (FULL, "Parsing configuration file: %s...", conffile);
	
	rtun_confin = fopen(conffile, "r");
	if (rtun_confin == NULL) {
		ret = errno;
		fd_log_debug("Unable to open extension configuration file %s for reading: %s\n", conffile, strerror(ret));
		TRACE_DEBUG (INFO, "Error occurred, message logged -- configuration file.");
		return ret;
	}

	ret = yyparse(conffile);

	fclose(rtun_confin);

	if (ret != 0) {
		TRACE_DEBUG (INFO, "Unable to parse the configuration file.");
		return EINVAL;
	} else {
		TRACE_DEBUG(FULL, "[rt-un-nb] Added %d servers successfully.", rtun_conf.serv_nb);
	}
	
	return 0;
}

/* The Lex parser prototype */
int rtun_conflex(YYSTYPE *lvalp, YYLTYPE *llocp);

/* Function to report the errors */
void yyerror (YYLTYPE *ploc, char * conffile, char const *s)
{
	TRACE_DEBUG(INFO, "Error in configuration parsing");
	
	if (ploc->first_line != ploc->last_line)
		fd_log_debug("%s:%d.%d-%d.%d : %s\n", conffile, ploc->first_line, ploc->first_column, ploc->last_line, ploc->last_column, s);
	else if (ploc->first_column != ploc->last_column)
		fd_log_debug("%s:%d.%d-%d : %s\n", conffile, ploc->first_line, ploc->first_column, ploc->last_column, s);
	else
		fd_log_debug("%s:%d.%d : %s\n", conffile, ploc->first_line, ploc->first_column, s);
}

%}

/* Values returned by lex for token */
%union {
	char 		*string;	/* The string is allocated by strdup in lex.*/
}

/* In case of error in the lexical analysis */
%token 		LEX_ERROR

/* A (de)quoted string (malloc'd in lex parser; it must be freed after use) */
%token <string>	QSTRING

/* Tokens */
%token 		SERV


/* -------------------------------------- */
%%

	/* The grammar definition */
conffile:		/* empty grammar is OK */
			| conffile serv
			;
			
	/* a server entry */
serv:			SERV '=' QSTRING ';'
			{
				/* Add this new server in the list */
				rtun_conf.serv_nb += 1;
				CHECK_MALLOC_DO( rtun_conf.servs = realloc(rtun_conf.servs, rtun_conf.serv_nb * sizeof(char *)),
					{
						yyerror (&yylloc, conffile, "Not enough memory to store the configuration...");
						YYERROR;
					} );
				
				rtun_conf.servs[rtun_conf.serv_nb - 1] = $3;
			}
			;