1 files changed, 138 insertions, 0 deletions
diff --git a/extensions/libxt_ecn.c b/extensions/libxt_ecn.c
new file mode 100644
index 0000000..286782a
--- /dev/null
+++ b/extensions/libxt_ecn.c
@@ -0,0 +1,138 @@
+/* Shared library add-on to iptables for ECN matching
+ *
+ * (C) 2002 by Harald Welte <laforge@netfilter.org>
+ * (C) 2011 by Patrick McHardy <kaber@trash.net>
+ *
+ * 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 <xtables.h>
+#include <linux/netfilter/xt_ecn.h>
+
+enum {
+	O_ECN_TCP_CWR = 0,
+	O_ECN_TCP_ECE,
+	O_ECN_IP_ECT,
+};
+
+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/IPv6 header\n");
+}
+
+static const struct xt_option_entry ecn_opts[] = {
+	{.name = "ecn-tcp-cwr", .id = O_ECN_TCP_CWR, .type = XTTYPE_NONE,
+	 .flags = XTOPT_INVERT},
+	{.name = "ecn-tcp-ece", .id = O_ECN_TCP_ECE, .type = XTTYPE_NONE,
+	 .flags = XTOPT_INVERT},
+	{.name = "ecn-ip-ect", .id = O_ECN_IP_ECT, .type = XTTYPE_UINT8,
+	 .min = 0, .max = 3, .flags = XTOPT_INVERT},
+	XTOPT_TABLEEND,
+};
+
+static void ecn_parse(struct xt_option_call *cb)
+{
+	struct xt_ecn_info *einfo = cb->data;
+
+	xtables_option_parse(cb);
+	switch (cb->entry->id) {
+	case O_ECN_TCP_CWR:
+		einfo->operation |= XT_ECN_OP_MATCH_CWR;
+		if (cb->invert)
+			einfo->invert |= XT_ECN_OP_MATCH_CWR;
+		break;
+	case O_ECN_TCP_ECE:
+		einfo->operation |= XT_ECN_OP_MATCH_ECE;
+		if (cb->invert)
+			einfo->invert |= XT_ECN_OP_MATCH_ECE;
+		break;
+	case O_ECN_IP_ECT:
+		if (cb->invert)
+			einfo->invert |= XT_ECN_OP_MATCH_IP;
+		einfo->operation |= XT_ECN_OP_MATCH_IP;
+		einfo->ip_ect = cb->val.u8;
+		break;
+	}
+}
+
+static void ecn_check(struct xt_fcheck_call *cb)
+{
+	if (cb->xflags == 0)
+		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 xt_ecn_info *einfo =
+		(const struct xt_ecn_info *)match->data;
+
+	printf(" ECN match");
+
+	if (einfo->operation & XT_ECN_OP_MATCH_ECE) {
+		printf(" %sECE",
+		       (einfo->invert & XT_ECN_OP_MATCH_ECE) ? "!" : "");
+	}
+
+	if (einfo->operation & XT_ECN_OP_MATCH_CWR) {
+		printf(" %sCWR",
+		       (einfo->invert & XT_ECN_OP_MATCH_CWR) ? "!" : "");
+	}
+
+	if (einfo->operation & XT_ECN_OP_MATCH_IP) {
+		printf(" %sECT=%d",
+		       (einfo->invert & XT_ECN_OP_MATCH_IP) ? "!" : "",
+		       einfo->ip_ect);
+	}
+}
+
+static void ecn_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_ecn_info *einfo =
+		(const struct xt_ecn_info *)match->data;
+
+	if (einfo->operation & XT_ECN_OP_MATCH_ECE) {
+		if (einfo->invert & XT_ECN_OP_MATCH_ECE)
+			printf(" !");
+		printf(" --ecn-tcp-ece");
+	}
+
+	if (einfo->operation & XT_ECN_OP_MATCH_CWR) {
+		if (einfo->invert & XT_ECN_OP_MATCH_CWR)
+			printf(" !");
+		printf(" --ecn-tcp-cwr");
+	}
+
+	if (einfo->operation & XT_ECN_OP_MATCH_IP) {
+		if (einfo->invert & XT_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_UNSPEC,
+	.size          = XT_ALIGN(sizeof(struct xt_ecn_info)),
+	.userspacesize = XT_ALIGN(sizeof(struct xt_ecn_info)),
+	.help          = ecn_help,
+	.print         = ecn_print,
+	.save          = ecn_save,
+	.x6_parse      = ecn_parse,
+	.x6_fcheck     = ecn_check,
+	.x6_options    = ecn_opts,
+};
+
+void _init(void)
+{
+	xtables_register_match(&ecn_mt_reg);
+}