1 files changed, 94 insertions, 0 deletions
diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c
new file mode 100644
index 000000000..a8e2425e4
--- /dev/null
+++ b/net/netfilter/nf_dup_netdev.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_offload.h>
+#include <net/netfilter/nf_dup_netdev.h>
+
+#define NF_RECURSION_LIMIT	2
+
+static DEFINE_PER_CPU(u8, nf_dup_skb_recursion);
+
+static void nf_do_netdev_egress(struct sk_buff *skb, struct net_device *dev,
+				enum nf_dev_hooks hook)
+{
+	if (__this_cpu_read(nf_dup_skb_recursion) > NF_RECURSION_LIMIT)
+		goto err;
+
+	if (hook == NF_NETDEV_INGRESS && skb_mac_header_was_set(skb)) {
+		if (skb_cow_head(skb, skb->mac_len))
+			goto err;
+
+		skb_push(skb, skb->mac_len);
+	}
+
+	skb->dev = dev;
+	skb_clear_tstamp(skb);
+	__this_cpu_inc(nf_dup_skb_recursion);
+	dev_queue_xmit(skb);
+	__this_cpu_dec(nf_dup_skb_recursion);
+	return;
+err:
+	kfree_skb(skb);
+}
+
+void nf_fwd_netdev_egress(const struct nft_pktinfo *pkt, int oif)
+{
+	struct net_device *dev;
+
+	dev = dev_get_by_index_rcu(nft_net(pkt), oif);
+	if (!dev) {
+		kfree_skb(pkt->skb);
+		return;
+	}
+
+	nf_do_netdev_egress(pkt->skb, dev, nft_hook(pkt));
+}
+EXPORT_SYMBOL_GPL(nf_fwd_netdev_egress);
+
+void nf_dup_netdev_egress(const struct nft_pktinfo *pkt, int oif)
+{
+	struct net_device *dev;
+	struct sk_buff *skb;
+
+	dev = dev_get_by_index_rcu(nft_net(pkt), oif);
+	if (dev == NULL)
+		return;
+
+	skb = skb_clone(pkt->skb, GFP_ATOMIC);
+	if (skb)
+		nf_do_netdev_egress(skb, dev, nft_hook(pkt));
+}
+EXPORT_SYMBOL_GPL(nf_dup_netdev_egress);
+
+int nft_fwd_dup_netdev_offload(struct nft_offload_ctx *ctx,
+			       struct nft_flow_rule *flow,
+			       enum flow_action_id id, int oif)
+{
+	struct flow_action_entry *entry;
+	struct net_device *dev;
+
+	/* nft_flow_rule_destroy() releases the reference on this device. */
+	dev = dev_get_by_index(ctx->net, oif);
+	if (!dev)
+		return -EOPNOTSUPP;
+
+	entry = &flow->rule->action.entries[ctx->num_actions++];
+	entry->id = id;
+	entry->dev = dev;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nft_fwd_dup_netdev_offload);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("Netfilter packet duplication support");