extensions/rt_busypeers/rtbusy_conf.y

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* Author: Sebastien Decugis <sdecugis@freediameter.net>							 *
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/* Yacc extension's configuration parser.
 */

/* 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 "rtbusy.h"
#include "rtbusy_conf.tab.h"

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

/* Parse the configuration file */
int rtbusy_conf_handle(char * conffile)
{
	extern FILE * rtbusy_confin;
	int ret;
	
	TRACE_ENTRY("%p", conffile);
	
	TRACE_DEBUG (FULL, "Parsing configuration file: %s...", conffile);
	
	rtbusy_confin = fopen(conffile, "r");
	if (rtbusy_confin == NULL) {
		ret = errno;
		TRACE_ERROR("Unable to open extension configuration file %s for reading: %s", conffile, strerror(ret));
		return ret;
	}

	ret = yyparse(conffile);

	fclose(rtbusy_confin);

	if (ret != 0) {
		TRACE_ERROR( "Unable to parse the configuration file.");
		return EINVAL;
	} else {
		TRACE_DEBUG(FULL, "[rt_busypeers] Configuration: %d-%d-%d-%d.", rtbusy_conf.SkipTooBusyErrors, rtbusy_conf.RetryDistantPeers, rtbusy_conf.RetryMaxPeers, rtbusy_conf.RelayTimeout);
	}
	
	return 0;
}

/* The Lex parser prototype */
int rtbusy_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_error("%s:%d.%d-%d.%d : %s", conffile, ploc->first_line, ploc->first_column, ploc->last_line, ploc->last_column, s);
	else if (ploc->first_column != ploc->last_column)
		fd_log_error("%s:%d.%d-%d : %s", conffile, ploc->first_line, ploc->first_column, ploc->last_column, s);
	else
		fd_log_error("%s:%d.%d : %s", conffile, ploc->first_line, ploc->first_column, s);
}

%}

/* Values returned by lex for token */
%union {
	int		integer;
}

/* 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 <integer> INTEGER

/* Tokens */
%token 		SKIPTOOBUSYERRORS
%token 		RETRYDISTANTPEERS
%token 		RETRYMAXPEERS
%token 		RELAYTIMEOUT


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

	/* The grammar definition */
conffile:		/* empty is OK */
			| conffile toobusy
			| conffile distant
			| conffile maxretry
			| conffile timeout
			| conffile errors
			{
				yyerror(&yylloc, conffile, "An error occurred while parsing the configuration file");
				return EINVAL;
			}
			;
			
			/* Lexical or syntax error */
errors:			LEX_ERROR
			| error
			;

toobusy:		SKIPTOOBUSYERRORS ';'
			{
				rtbusy_conf.SkipTooBusyErrors=1;
			}
			;
			
distant:		RETRYDISTANTPEERS ';'
			{
				rtbusy_conf.RetryDistantPeers=1;
			}
			;
			
maxretry:		RETRYMAXPEERS '=' INTEGER ';'
			{
				rtbusy_conf.RetryMaxPeers=$3;
			}
			;
			
timeout:		RELAYTIMEOUT '=' INTEGER ';'
			{
				rtbusy_conf.RelayTimeout=$3;
			}
			;