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1 files changed, 169 insertions, 0 deletions

diff --git a/extensions/libipt_ECN.c b/extensions/libipt_ECN.c
new file mode 100644
index 0000000..bf1f8a5
--- /dev/null
+++ b/extensions/libipt_ECN.c
@@ -0,0 +1,169 @@
+/* Shared library add-on to iptables for ECN, $Version$
+ *
+ * (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
+ *
+ * $Id$
+ */
+#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 target options\n"
+"  --ecn-tcp-remove		Remove all ECN bits from TCP header\n");
+}
+
+#if 0
+"ECN target v%s EXPERIMENTAL options (use with extreme care!)\n"
+"  --ecn-ip-ect			Set the IPv4 ECT codepoint (0 to 3)\n"
+"  --ecn-tcp-cwr		Set the IPv4 CWR bit (0 or 1)\n"
+"  --ecn-tcp-ece		Set the IPv4 ECE bit (0 or 1)\n",
+#endif
+
+
+static const struct option ECN_opts[] = {
+	{ "ecn-tcp-remove", 0, NULL, 'F' },
+	{ "ecn-tcp-cwr", 1, NULL, 'G' },
+	{ "ecn-tcp-ece", 1, NULL, 'H' },
+	{ "ecn-ip-ect", 1, NULL, '9' },
+	{ .name = NULL }
+};
+
+static int ECN_parse(int c, char **argv, int invert, unsigned int *flags,
+                     const void *entry, struct xt_entry_target **target)
+{
+	unsigned int result;
+	struct ipt_ECN_info *einfo
+		= (struct ipt_ECN_info *)(*target)->data;
+
+	switch (c) {
+	case 'F':
+		if (*flags)
+			xtables_error(PARAMETER_PROBLEM,
+			        "ECN target: Only use --ecn-tcp-remove ONCE!");
+		einfo->operation = IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR;
+		einfo->proto.tcp.ece = 0;
+		einfo->proto.tcp.cwr = 0;
+		*flags = 1;
+		break;
+	case 'G':
+		if (*flags & IPT_ECN_OP_SET_CWR)
+			xtables_error(PARAMETER_PROBLEM,
+				"ECN target: Only use --ecn-tcp-cwr ONCE!");
+		if (!xtables_strtoui(optarg, NULL, &result, 0, 1))
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN target: Value out of range");
+		einfo->operation |= IPT_ECN_OP_SET_CWR;
+		einfo->proto.tcp.cwr = result;
+		*flags |= IPT_ECN_OP_SET_CWR;
+		break;
+	case 'H':
+		if (*flags & IPT_ECN_OP_SET_ECE)
+			xtables_error(PARAMETER_PROBLEM,
+				"ECN target: Only use --ecn-tcp-ece ONCE!");
+		if (!xtables_strtoui(optarg, NULL, &result, 0, 1))
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN target: Value out of range");
+		einfo->operation |= IPT_ECN_OP_SET_ECE;
+		einfo->proto.tcp.ece = result;
+		*flags |= IPT_ECN_OP_SET_ECE;
+		break;
+	case '9':
+		if (*flags & IPT_ECN_OP_SET_IP)
+			xtables_error(PARAMETER_PROBLEM,
+				"ECN target: Only use --ecn-ip-ect ONCE!");
+		if (!xtables_strtoui(optarg, NULL, &result, 0, 3))
+			xtables_error(PARAMETER_PROBLEM,
+				   "ECN target: Value out of range");
+		einfo->operation |= IPT_ECN_OP_SET_IP;
+		einfo->ip_ect = result;
+		*flags |= IPT_ECN_OP_SET_IP;
+		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static void ECN_check(unsigned int flags)
+{
+	if (!flags)
+		xtables_error(PARAMETER_PROBLEM,
+		           "ECN target: Parameter --ecn-tcp-remove is required");
+}
+
+static void ECN_print(const void *ip, const struct xt_entry_target *target,
+                      int numeric)
+{
+	const struct ipt_ECN_info *einfo =
+		(const struct ipt_ECN_info *)target->data;
+
+	printf("ECN ");
+
+	if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
+	    && einfo->proto.tcp.ece == 0
+	    && einfo->proto.tcp.cwr == 0)
+		printf("TCP remove ");
+	else {
+		if (einfo->operation & IPT_ECN_OP_SET_ECE)
+			printf("ECE=%u ", einfo->proto.tcp.ece);
+
+		if (einfo->operation & IPT_ECN_OP_SET_CWR)
+			printf("CWR=%u ", einfo->proto.tcp.cwr);
+
+		if (einfo->operation & IPT_ECN_OP_SET_IP)
+			printf("ECT codepoint=%u ", einfo->ip_ect);
+	}
+}
+
+static void ECN_save(const void *ip, const struct xt_entry_target *target)
+{
+	const struct ipt_ECN_info *einfo =
+		(const struct ipt_ECN_info *)target->data;
+
+	if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
+	    && einfo->proto.tcp.ece == 0
+	    && einfo->proto.tcp.cwr == 0)
+		printf("--ecn-tcp-remove ");
+	else {
+
+		if (einfo->operation & IPT_ECN_OP_SET_ECE)
+			printf("--ecn-tcp-ece %d ", einfo->proto.tcp.ece);
+
+		if (einfo->operation & IPT_ECN_OP_SET_CWR)
+			printf("--ecn-tcp-cwr %d ", einfo->proto.tcp.cwr);
+
+		if (einfo->operation & IPT_ECN_OP_SET_IP)
+			printf("--ecn-ip-ect %d ", einfo->ip_ect);
+	}
+}
+
+static struct xtables_target ecn_tg_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_target(&ecn_tg_reg);
+}