Git init

1 files changed, 160 insertions, 0 deletions

diff --git a/extensions/libipt_ecn.c b/extensions/libipt_ecn.c
new file mode 100644
index 0000000..ec3ff2d
--- /dev/null
+++ b/extensions/libipt_ecn.c
@@ -0,0 +1,160 @@
+/* Shared library add-on to iptables for ECN matching
+ *
+ * (C) 2002 by Harald Welte <laforge@gnumonks.org>
+ *
+ * This program is distributed under the terms of GNU GPL v2, 1991
+ *
+ * libipt_ecn.c borrowed heavily from libipt_dscp.c
+ *
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <xtables.h>
+#include <linux/netfilter_ipv4/ipt_ecn.h>
+
+static void ecn_help(void)
+{
+	printf(
+"ECN match options\n"
+"[!] --ecn-tcp-cwr 		Match CWR bit of TCP header\n"
+"[!] --ecn-tcp-ece		Match ECE bit of TCP header\n"
+"[!] --ecn-ip-ect [0..3]	Match ECN codepoint in IPv4 header\n");
+}
+
+static const struct option ecn_opts[] = {
+	{ .name = "ecn-tcp-cwr", .has_arg = 0, .val = 'F' },
+	{ .name = "ecn-tcp-ece", .has_arg = 0, .val = 'G' },
+	{ .name = "ecn-ip-ect",  .has_arg = 1, .val = 'H' },
+	{ .name = NULL }
+};
+
+static int ecn_parse(int c, char **argv, int invert, unsigned int *flags,
+                     const void *entry, struct xt_entry_match **match)
+{
+	unsigned int result;
+	struct ipt_ecn_info *einfo
+		= (struct ipt_ecn_info *)(*match)->data;
+
+	switch (c) {
+	case 'F':
+		if (*flags & IPT_ECN_OP_MATCH_CWR)
+			xtables_error(PARAMETER_PROBLEM,
+			           "ECN match: can only use parameter ONCE!");
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		einfo->operation |= IPT_ECN_OP_MATCH_CWR;
+		if (invert)
+			einfo->invert |= IPT_ECN_OP_MATCH_CWR;
+		*flags |= IPT_ECN_OP_MATCH_CWR;
+		break;
+
+	case 'G':
+		if (*flags & IPT_ECN_OP_MATCH_ECE)
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN match: can only use parameter ONCE!");
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		einfo->operation |= IPT_ECN_OP_MATCH_ECE;
+		if (invert)
+			einfo->invert |= IPT_ECN_OP_MATCH_ECE;
+		*flags |= IPT_ECN_OP_MATCH_ECE;
+		break;
+
+	case 'H':
+		if (*flags & IPT_ECN_OP_MATCH_IP)
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN match: can only use parameter ONCE!");
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		if (invert)
+			einfo->invert |= IPT_ECN_OP_MATCH_IP;
+		*flags |= IPT_ECN_OP_MATCH_IP;
+		einfo->operation |= IPT_ECN_OP_MATCH_IP;
+		if (!xtables_strtoui(optarg, NULL, &result, 0, 3))
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN match: Value out of range");
+		einfo->ip_ect = result;
+		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static void ecn_check(unsigned int flags)
+{
+	if (!flags)
+		xtables_error(PARAMETER_PROBLEM,
+		           "ECN match: some option required");
+}
+
+static void ecn_print(const void *ip, const struct xt_entry_match *match,
+                      int numeric)
+{
+	const struct ipt_ecn_info *einfo =
+		(const struct ipt_ecn_info *)match->data;
+
+	printf("ECN match ");
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
+			fputc('!', stdout);
+		printf("ECE ");
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
+			fputc('!', stdout);
+		printf("CWR ");
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_IP)
+			fputc('!', stdout);
+		printf("ECT=%d ", einfo->ip_ect);
+	}
+}
+
+static void ecn_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct ipt_ecn_info *einfo =
+		(const struct ipt_ecn_info *)match->data;
+	
+	if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
+			printf("! ");
+		printf("--ecn-tcp-ece ");
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
+			printf("! ");
+		printf("--ecn-tcp-cwr ");
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_IP)
+			printf("! ");
+		printf("--ecn-ip-ect %d", einfo->ip_ect);
+	}
+}
+
+static struct xtables_match ecn_mt_reg = {
+    .name          = "ecn",
+    .version       = XTABLES_VERSION,
+    .family        = NFPROTO_IPV4,
+    .size          = XT_ALIGN(sizeof(struct ipt_ecn_info)),
+    .userspacesize = XT_ALIGN(sizeof(struct ipt_ecn_info)),
+    .help          = ecn_help,
+    .parse         = ecn_parse,
+    .final_check   = ecn_check,
+    .print         = ecn_print,
+    .save          = ecn_save,
+    .extra_opts    = ecn_opts,
+};
+
+void _init(void)
+{
+	xtables_register_match(&ecn_mt_reg);
+}