first step forward to merge conntrackd and conntrack into the same building chain

1 files changed, 180 insertions, 0 deletions

diff --git a/extensions/libct_proto_tcp.c b/extensions/libct_proto_tcp.c
new file mode 100644
index 0000000..ee24206
--- /dev/null
+++ b/extensions/libct_proto_tcp.c
@@ -0,0 +1,180 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h> /* For htons */
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_tcp.h>
+
+#include "conntrack.h"
+
+static struct option opts[] = {
+	{"orig-port-src", 1, 0, '1'},
+	{"orig-port-dst", 1, 0, '2'},
+	{"reply-port-src", 1, 0, '3'},
+	{"reply-port-dst", 1, 0, '4'},
+	{"mask-port-src", 1, 0, '5'},
+	{"mask-port-dst", 1, 0, '6'},
+	{"state", 1, 0, '7'},
+	{"tuple-port-src", 1, 0, '8'},
+	{"tuple-port-dst", 1, 0, '9'},
+	{0, 0, 0, 0}
+};
+
+static const char *states[] = {
+	"NONE",
+	"SYN_SENT",
+	"SYN_RECV",
+	"ESTABLISHED",
+	"FIN_WAIT",
+	"CLOSE_WAIT",
+	"LAST_ACK",
+	"TIME_WAIT",
+	"CLOSE",
+	"LISTEN"
+};
+
+static void help()
+{
+	fprintf(stdout, "--orig-port-src        original source port\n");
+	fprintf(stdout, "--orig-port-dst        original destination port\n");
+	fprintf(stdout, "--reply-port-src       reply source port\n");
+	fprintf(stdout, "--reply-port-dst       reply destination port\n");
+	fprintf(stdout, "--mask-port-src	mask source port\n");
+	fprintf(stdout, "--mask-port-dst	mask destination port\n");
+	fprintf(stdout, "--tuple-port-src	expectation tuple src port\n");
+	fprintf(stdout, "--tuple-port-src	expectation tuple dst port\n");
+	fprintf(stdout, "--state                TCP state, fe. ESTABLISHED\n");
+}
+
+static int parse_options(char c, char *argv[], 
+			 struct nfct_tuple *orig,
+			 struct nfct_tuple *reply,
+			 struct nfct_tuple *exptuple,
+			 struct nfct_tuple *mask,
+			 union nfct_protoinfo *proto,
+			 unsigned int *flags)
+{
+	switch(c) {
+		case '1':
+			if (optarg) {
+				orig->l4src.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_ORIG_SPORT;
+			}
+			break;
+		case '2':
+			if (optarg) {
+				orig->l4dst.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_ORIG_DPORT;
+			}
+			break;
+		case '3':
+			if (optarg) {
+				reply->l4src.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_REPL_SPORT;
+			}
+			break;
+		case '4':
+			if (optarg) {
+				reply->l4dst.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_REPL_DPORT;
+			}
+			break;
+		case '5':
+			if (optarg) {
+				mask->l4src.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_MASK_SPORT;
+			}
+			break;
+		case '6':
+			if (optarg) {
+				mask->l4dst.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_MASK_DPORT;
+			}
+			break;
+		case '7':
+			if (optarg) {
+				int i;
+				for (i=0; i<10; i++) {
+					if (strcmp(optarg, states[i]) == 0) {
+						proto->tcp.state = i;
+						break;
+					}
+				}
+				if (i == 10) {
+					printf("doh?\n");
+					return 0;
+				}
+				*flags |= TCP_STATE;
+			}
+			break;
+		case '8':
+			if (optarg) {
+				exptuple->l4src.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_EXPTUPLE_SPORT;
+			}
+			break;
+		case '9':
+			if (optarg) {
+				exptuple->l4dst.tcp.port = htons(atoi(optarg));
+				*flags |= TCP_EXPTUPLE_DPORT;
+			}
+			break;
+	}
+	return 1;
+}
+
+static int final_check(unsigned int flags,
+		       unsigned int command,
+		       struct nfct_tuple *orig,
+		       struct nfct_tuple *reply)
+{
+	int ret = 0;
+	
+	if ((flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT)) 
+	    && !(flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
+		reply->l4src.tcp.port = orig->l4dst.tcp.port;
+		reply->l4dst.tcp.port = orig->l4src.tcp.port;
+		ret = 1;
+	} else if (!(flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
+	            && (flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
+		orig->l4src.tcp.port = reply->l4dst.tcp.port;
+		orig->l4dst.tcp.port = reply->l4src.tcp.port;
+		ret = 1;
+	}
+	if ((flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT)) 
+	    && ((flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))))
+		ret = 1;
+
+	/* --state is missing and we are trying to create a conntrack */
+	if (ret && (command & CT_CREATE) && (!(flags & TCP_STATE)))
+		ret = 0;
+
+	return ret;
+}
+
+static struct ctproto_handler tcp = {
+	.name 			= "tcp",
+	.protonum		= IPPROTO_TCP,
+	.parse_opts		= parse_options,
+	.final_check		= final_check,
+	.help			= help,
+	.opts			= opts,
+	.version		= VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+	register_proto(&tcp);
+}