MPLS: initial check-in.

ebtables-mpls/Makefile

@@ -0,0 +1,47 @@
+#
+# Copyright (C) 2024 IOPSYS Software Solutions AB
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=lre-mpls
+PKG_VERSION:=1.0.0
+PKG_LICENSE:=GPL-2.0
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/ebtables-mpls
+  SUBMENU:=Other modules
+  TITLE:=Kernel module for ebtables MPLS LER
+  FILES:=$(PKG_BUILD_DIR)/ebt_mpls.ko
+  DEPENDS+=+kmod-ebtables +ebtables-legacy
+  AUTOLOAD:=$(call AutoLoad,30,ebt_mpls,1)
+  KCONFIG:=
+endef
+
+define KernelPackage/ebtables-mpls/description
+	Kernel module to enable MPLS support for ebtables
+endef
+
+ifeq ($(CONFIG_TARGET_brcmbca),y)
+	include ../../broadcom/bcmkernel/bcm-kernel-toolchain.mk
+endif
+
+define Build/Prepare
+	$(CP) -rf ./src/* $(PKG_BUILD_DIR)/
+	$(CP) $(PKG_BUILD_DIR)/ebt_mpls.h $(LINUX_DIR)/include/uapi/linux/netfilter_bridge/
+endef
+
+define Build/InstallDev
+	$(INSTALL_DIR) $(1)/include/uapi/linux/netfilter_bridge/
+	$(CP) $(PKG_BUILD_DIR)/ebt_mpls.h $(1)/include/uapi/linux/netfilter_bridge/
+endef
+
+KERNEL_MAKE_FLAGS += -I$(LINUX_DIR)/include
+
+define Build/Compile
+	$(KERNEL_MAKE) M="$(PKG_BUILD_DIR)" modules
+endef
+
+$(eval $(call KernelPackage,ebtables-mpls))

ebtables-mpls/src/Makefile

@@ -0,0 +1 @@
+obj-m += ebt_mpls.o

ebtables-mpls/src/ebt_mpls.c

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+/*
+ *  ebt_mpls
+ *
+ *	Authors:
+ *	Markus Gothe <markus.gothe@genexis.eu>
+ *
+ *	January, 2025
+ *
+ *	SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/module.h>
+#include <linux/if_vlan.h>
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/netfilter.h>
+#include <net/mpls.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_mpls.h>
+#include <net/netfilter/br_netfilter.h>
+
+static unsigned int ebt_mpls_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct ebt_mpls_info *info = par->targinfo;
+
+	if (info->decap && eth_p_mpls(eth_hdr(skb)->h_proto) && mpls_hdr(skb)->label_stack_entry == info->label) {
+		skb_push(skb, ETH_HLEN);
+		if (skb_mpls_pop(skb, info->protocol, ETH_HLEN, true))
+			return EBT_DROP;
+
+		skb_pull(skb, ETH_HLEN);
+		skb_reset_mac_len(skb);
+	} else if (eth_hdr(skb)->h_proto == info->protocol) {
+		skb_push(skb, ETH_HLEN);
+		if (skb_mpls_push(skb, info->label, info->multicast ? htons(ETH_P_MPLS_MC) : htons(ETH_P_MPLS_UC), ETH_HLEN, true))
+			return EBT_DROP;
+
+		skb_pull(skb, ETH_HLEN);
+		skb_reset_mac_len(skb);
+	}
+
+	return info->target;
+}
+
+static int ebt_mpls_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ebt_mpls_info *info = par->targinfo;
+	unsigned int hook_mask;
+
+	if (BASE_CHAIN && info->target == EBT_RETURN)
+		return -EINVAL;
+
+	hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
+
+	if ((strcmp(par->table, "nat") != 0 || hook_mask & ~((1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_POST_ROUTING) | (1 << NF_BR_LOCAL_OUT))) &&
+	(strcmp(par->table, "broute") != 0 || hook_mask & ~(1 << NF_BR_BROUTING)) &&
+	(strcmp(par->table, "filter") != 0 || hook_mask & ~(1 << NF_BR_LOCAL_IN)))
+		return -EINVAL;
+	if (ebt_invalid_target(info->target))
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct xt_target ebt_mpls_tg_reg __read_mostly = {
+	.name		= "mpls",
+	.revision	= 0,
+	.family		= NFPROTO_BRIDGE,
+	.hooks		= (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_POST_ROUTING) | (1 << NF_BR_LOCAL_OUT) | (1 << NF_BR_LOCAL_IN) | (1 << NF_BR_BROUTING),
+	.target		= ebt_mpls_tg,
+	.checkentry	= ebt_mpls_tg_check,
+	.targetsize	= sizeof(struct ebt_mpls_info),
+	.me		= THIS_MODULE,
+};
+
+static int __init ebt_mpls_init(void)
+{
+	return xt_register_target(&ebt_mpls_tg_reg);
+}
+
+static void __exit ebt_mpls_fini(void)
+{
+	xt_unregister_target(&ebt_mpls_tg_reg);
+}
+
+module_init(ebt_mpls_init);
+module_exit(ebt_mpls_fini);
+MODULE_DESCRIPTION("Ebtables: MPLS forwarding");
+MODULE_LICENSE("GPL");

ebtables-mpls/src/ebt_mpls.h

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+/*
+ *  ebt_mpls
+ *
+ *	Authors:
+ *	Markus Gothe <markus.gothe@genexis.eu>
+ *
+ *	January, 2025
+ *	SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+ */
+
+#ifndef __LINUX_BRIDGE_EBT_MPLS_H
+#define __LINUX_BRIDGE_EBT_MPLS_H
+
+#include <linux/types.h>
+#include <linux/if_ether.h>
+
+struct ebt_mpls_info
+{
+	__be16 protocol;
+	__be32 label;
+	int target;
+	bool decap;
+	bool multicast;
+	uint8_t bitmask;
+	uint8_t invflags;
+};
+
+#endif