initial commit

This patch bootstrap the new nft-sync software. Basically, this
software aims to support two different setups:

1) Rule-set repository server. The software serves the nft rule-set to
   clients that request the ruleset.

   Basically from the system that acts as repository, you have to run:

   # nft-sync -c ../contrib/nft-sync.conf.server

   Then, from the client:

   # nft-sync -c ../contrib/nft-sync.conf.client --fetch

   Which displays the nft rule-set in the standard output, so you
   can inspect the nft rule-set.

   Alternatively, the client can also retrieve and apply the nft
   rule-set using the pull command instead:

   # nft-sync -c ../contrib/nft-sync.conf.client --pull

   [ Note that this command above does not work in this bootstrap yet ]

2) Rule-set synchronization: In case of primary-backup and multiprimary
   firewall configurations, the software makes sure that the firewall
   cluster is deploying the same filtering policy. In this case, you have
   to launch the process:

   # nft-sync -c ../contrib/nft-sync.conf --sync

   [ Note that this command above does not work in this bootstrap yet ]

This bootstrap provides the basic infrastructure as a proof-of-concept.
Many of the necessary features are still lacking:

* Implement --sync and --pull commands.

* Interaction with nft through libnftnl, which allows the software to
  retrieve the local nft rule-set, as well as to parse it and apply it.

* SSL support, specifically the repository mode needs it to make sure
  nobody can steal your filtering policy from the network.

* IPv6 support.

* Allow to serve different rule-sets in the repository mode.

And many others that will be added progressively.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/src/config-parser.y b/src/config-parser.y
new file mode 100644
index 0000000..41c37b9
--- /dev/null
+++ b/src/config-parser.y
@@ -0,0 +1,143 @@
+%{
+/*
+ * (C) 2014 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <netinet/in.h>
+
+#include "config.h"
+#include "logging.h"
+
+extern char *yytext;
+extern int yylineno;
+
+static int parse_addr(const char *text, struct in_addr *addr,
+			 uint16_t *port)
+{
+	char *colon = strchr(text, ':');
+
+	if (colon == NULL) {
+		fprintf(stderr, "missing `:' to indicate port\n");
+		return -1;
+	}
+	*colon = '\0';
+
+	if (inet_pton(AF_INET, text, addr) < 0) {
+		fprintf(stderr, "%s not valid IPv4 address\n", text);
+		return -1;
+	}
+	*port = atoi(colon + 1);
+
+	return 0;
+}
+
+%}
+
+%union {
+	int	val;
+	char	*string;
+}
+
+%token T_LOCAL_ADDR
+%token T_REMOTE_ADDR
+%token T_ADDR
+%token T_NUMBER
+%token T_LOG
+%token T_MODE
+
+%token <string> T_STRING
+%token <val>	T_INTEGER
+
+%%
+
+configfile	:
+		| sections
+		;
+
+sections	: section
+		| sections section
+		;
+
+section		: network
+		| log
+		;
+
+network		: local_addr
+		| remote_addr
+		;
+
+local_addr	: T_LOCAL_ADDR T_STRING
+		{
+			nfts_inst.tcp.ipproto = AF_INET;
+			if (parse_addr($2,
+				       &nfts_inst.tcp.server.ipv4.inet_addr,
+				       &nfts_inst.tcp.port) < 0)
+				break;
+
+			nfts_inst.mode = NFTS_MODE_SERVER;
+		}
+		;
+
+remote_addr	: T_REMOTE_ADDR T_STRING
+		{
+			nfts_inst.tcp.ipproto = AF_INET;
+			if (parse_addr($2, &nfts_inst.tcp.client.inet_addr,
+				       &nfts_inst.tcp.port) < 0)
+				break;
+
+			nfts_inst.mode = NFTS_MODE_CLIENT;
+		}
+		;
+
+log		: T_LOG T_STRING
+		{
+			if (strcmp($2, "syslog") == 0) {
+				nfts_inst.log.type = NFTS_LOG_T_SYSLOG;
+			} else if (strcmp($2, "stdout") == 0) {
+				nfts_inst.log.type = NFTS_LOG_T_FILE;
+				nfts_inst.log.color = true;
+			} else {
+				nfts_inst.log.type = NFTS_LOG_T_FILE;
+				strncpy(nfts_inst.log.filename, $2, PATH_MAX);
+				nfts_inst.log.filename[PATH_MAX - 1] = '\0';
+			}
+		}
+		;
+
+%%
+
+int __attribute__((noreturn)) yyerror(char *msg)
+{
+	fprintf(stderr, "parsing config file in line (%d), symbol '%s': %s\n",
+			 yylineno, yytext, msg);
+	exit(EXIT_FAILURE);
+}
+
+int nft_sync_config_parse(const char *filename)
+{
+	FILE *fp;
+
+	fp = fopen(filename, "r");
+	if (!fp) {
+		fprintf(stderr, "Cannot open configuration file %s\n",
+			filename);
+		return -1;
+	}
+
+	yyrestart(fp);
+	yyparse();
+	fclose(fp);
+
+	return 0;
+}