rinetd/parse.peg

#  Copyright © 1997—1999 Thomas Boutell <boutell@boutell.com>
#                        and Boutell.Com, Inc.
#            © 2003—2017 Sam Hocevar <sam@hocevar.net>
#
#  This software is released for free use under the terms of
#  the GNU Public License, version 2 or higher. NO WARRANTY
#  IS EXPRESSED OR IMPLIED. USE THIS SOFTWARE AT YOUR OWN RISK. */

%{
#if HAVE_CONFIG_H
#	include <config.h>
#endif

#include "networking.h"
#include "types.h"
#include "rinetd.h"
#include "parse.h"

#define YY_CTX_LOCAL 1
#define YY_CTX_MEMBERS \
	FILE *fp; \
	int isAuthAllow; \
	char *tmpPort; \
	int tmpPortNum, tmpProto; \
	int bindPortNum, bindProto, connectPortNum, connectProto; \
	char *bindAddress, *connectAddress;
#define YY_INPUT(yyctx, buf, result, max_size) \
{ \
	int yyc = fgetc(yyctx->fp); \
	result = (EOF == yyc) ? 0 : (*(buf) = yyc, 1); \
}
#define PARSE_ERROR exit(1);

#if defined __clang__
#pragma clang diagnostic ignored "-Wunused-parameter"
#elif defined __GNUC__
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

%}

file     =  (line | invalid-syntax)*
line     =  -? (command -?)? comment? eol
command  =  (server | rule | logfile | pidlogfile | logcommon)
comment  =  "#" (!eol .)*

server  =  bind-address - bind-port - connect-address - connect-port {
	addServer(yy->bindAddress, yy->bindPortNum, yy->bindProto,
	          yy->connectAddress, yy->connectPortNum, yy->connectProto);
	yy->bindAddress = yy->connectAddress = NULL;
}

bind-address     =  < ipv4 > { yy->bindAddress = strdup(yytext); }
connect-address  =  < ipv4 > { yy->connectAddress = strdup(yytext); }
bind-port        =  full-port { yy->bindPortNum = yy->tmpPortNum; yy->bindProto = yy->tmpProto; }
connect-port     =  full-port { yy->connectPortNum = yy->tmpPortNum; yy->connectProto = yy->tmpProto; }

full-port  =  port proto {
	char const *proto = yy->tmpProto == protoTcp ? "tcp" : "udp";
	struct servent *service = getservbyname(yy->tmpPort, proto);
	yy->tmpPortNum = service ? ntohs(service->s_port) : atoi(yy->tmpPort);
	if (yy->tmpPortNum == 0 || yy->tmpPortNum >= 65536) {
		syslog(LOG_ERR, "port %s/%s missing or out of range\n", yy->tmpPort, proto);
		PARSE_ERROR;
	}
}

port   = < (number | service) >   { yy->tmpPort = strdup(yytext); }
proto  = '/tcp'                   { yy->tmpProto = protoTcp; }
       | '/udp'                   { yy->tmpProto = protoUdp; }
       | ''                       { yy->tmpProto = protoTcp; }

rule  =  auth-key - < pattern > {
	allRules = (Rule *)
		realloc(allRules, sizeof(Rule) * (allRulesCount + 1));
	if (!allRules) {
		PARSE_ERROR;
	}
	allRules[allRulesCount].pattern = strdup(yytext);
	if (!allRules[allRulesCount].pattern) {
		PARSE_ERROR;
	}
	allRules[allRulesCount].type = yy->isAuthAllow ? allowRule : denyRule;
	if (seTotal > 0) {
		if (seInfo[seTotal - 1].rulesStart == 0) {
			seInfo[seTotal - 1].rulesStart = allRulesCount;
		}
		++seInfo[seTotal - 1].rulesCount;
	} else {
		++globalRulesCount;
	}
	++allRulesCount;
}

auth-key = < ("allow" | "deny") >         { yy->isAuthAllow = (yytext[0] == 'a'); }

logfile  =  "logfile" - < filename > {
	logFileName = strdup(yytext);
	if (!logFileName) {
		PARSE_ERROR;
	}
}

pidlogfile  =  "pidlogfile" - < filename > {
	pidLogFileName = strdup(yytext);
	if (!pidLogFileName) {
		PARSE_ERROR;
	}
}

logcommon  =  "logcommon" {
	logFormatCommon = 1;
}

invalid-syntax  =  < (!eol .)* > eol { PARSE_ERROR; /* FIXME */ }

service  =  name
ipv4     =  number [.] number [.] number [.] number | '0'
pattern  =  [0-9*?]+ ('.' [0-9*?]+ ('.' [0-9*?]+ ('.' [0-9*?]+)?)?)?
number   =  digit+

name     =  [a-zA-Z][a-zA-Z0-9_]*
filename =  '"' [^"]+ '"'
         | [^ \t\r\n]+

-        =  [ \t]+
digit    =  [0-9]
eol      =  '\r'? '\n' | eof
eof      =  '\0'

%%

void parseConfiguration(char const *file) {
	FILE *in = fopen(file, "r");
	if (!in) {
		PARSE_ERROR;
	}

	yycontext ctx;
	memset(&ctx, 0, sizeof(yycontext));
	ctx.fp = in;
	if (!yyparse(&ctx)) {
		syslog(LOG_ERR, "invalid syntax "
			"on file %s, line %d.\n", file, -1);
		exit(1);
	}

	fclose(in);

	/* Avopid warnings for these unused functions */
	(void)yySet; (void)yyPush; (void)yyPop; (void)yyAccept;
}