1 files changed, 110 insertions, 0 deletions
diff --git a/net/netfilter/xt_dscp.c b/net/netfilter/xt_dscp.c
new file mode 100644
index 000000000..fb0169a8f
--- /dev/null
+++ b/net/netfilter/xt_dscp.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
+ *
+ * (C) 2002 by Harald Welte <laforge@netfilter.org>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/dsfield.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_dscp.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_dscp");
+MODULE_ALIAS("ip6t_dscp");
+MODULE_ALIAS("ipt_tos");
+MODULE_ALIAS("ip6t_tos");
+
+static bool
+dscp_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	const struct xt_dscp_info *info = par->matchinfo;
+	u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
+
+	return (dscp == info->dscp) ^ !!info->invert;
+}
+
+static bool
+dscp_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	const struct xt_dscp_info *info = par->matchinfo;
+	u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
+
+	return (dscp == info->dscp) ^ !!info->invert;
+}
+
+static int dscp_mt_check(const struct xt_mtchk_param *par)
+{
+	const struct xt_dscp_info *info = par->matchinfo;
+
+	if (info->dscp > XT_DSCP_MAX)
+		return -EDOM;
+
+	return 0;
+}
+
+static bool tos_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	const struct xt_tos_match_info *info = par->matchinfo;
+
+	if (xt_family(par) == NFPROTO_IPV4)
+		return ((ip_hdr(skb)->tos & info->tos_mask) ==
+		       info->tos_value) ^ !!info->invert;
+	else
+		return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
+		       info->tos_value) ^ !!info->invert;
+}
+
+static struct xt_match dscp_mt_reg[] __read_mostly = {
+	{
+		.name		= "dscp",
+		.family		= NFPROTO_IPV4,
+		.checkentry	= dscp_mt_check,
+		.match		= dscp_mt,
+		.matchsize	= sizeof(struct xt_dscp_info),
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "dscp",
+		.family		= NFPROTO_IPV6,
+		.checkentry	= dscp_mt_check,
+		.match		= dscp_mt6,
+		.matchsize	= sizeof(struct xt_dscp_info),
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "tos",
+		.revision	= 1,
+		.family		= NFPROTO_IPV4,
+		.match		= tos_mt,
+		.matchsize	= sizeof(struct xt_tos_match_info),
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "tos",
+		.revision	= 1,
+		.family		= NFPROTO_IPV6,
+		.match		= tos_mt,
+		.matchsize	= sizeof(struct xt_tos_match_info),
+		.me		= THIS_MODULE,
+	},
+};
+
+static int __init dscp_mt_init(void)
+{
+	return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
+}
+
+static void __exit dscp_mt_exit(void)
+{
+	xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
+}
+
+module_init(dscp_mt_init);
+module_exit(dscp_mt_exit);