From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 15 Mar 2018 21:15:00 +0100
Subject: [PATCH] net: pppoe: support hardware flow table offload

Pass on the PPPoE session ID and the remote MAC address

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -53,6 +53,11 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_flow_table.h>
+#endif
+
 #define PPP_VERSION	"2.4.2"
 
 /*
@@ -1378,12 +1383,37 @@ static void ppp_dev_priv_destructor(stru
 		ppp_destroy_interface(ppp);
 }
 
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+static int ppp_flow_offload_check(struct flow_offload_hw_path *path)
+{
+	struct ppp *ppp = netdev_priv(path->dev);
+	struct ppp_channel *chan;
+	struct channel *pch;
+
+	if (ppp->flags & SC_MULTILINK)
+		return -EOPNOTSUPP;
+
+	if (list_empty(&ppp->channels))
+		return -ENODEV;
+
+	pch = list_first_entry(&ppp->channels, struct channel, clist);
+	chan = pch->chan;
+	if (!chan->ops->flow_offload_check)
+		return -EOPNOTSUPP;
+
+	return chan->ops->flow_offload_check(chan, path);
+}
+#endif /* CONFIG_NF_FLOW_TABLE */
+
 static const struct net_device_ops ppp_netdev_ops = {
 	.ndo_init	 = ppp_dev_init,
 	.ndo_uninit      = ppp_dev_uninit,
 	.ndo_start_xmit  = ppp_start_xmit,
 	.ndo_do_ioctl    = ppp_net_ioctl,
 	.ndo_get_stats64 = ppp_get_stats64,
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+	.ndo_flow_offload_check = ppp_flow_offload_check,
+#endif
 };
 
 static struct device_type ppp_type = {
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -73,6 +73,11 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_flow_table.h>
+#endif
+
 #include <linux/nsproxy.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
@@ -974,8 +979,36 @@ static int pppoe_xmit(struct ppp_channel
 	return __pppoe_xmit(sk, skb);
 }
 
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+static int pppoe_flow_offload_check(struct ppp_channel *chan,
+				    struct flow_offload_hw_path *path)
+{
+	struct sock *sk = (struct sock *)chan->private;
+	struct pppox_sock *po = pppox_sk(sk);
+	struct net_device *dev = po->pppoe_dev;
+
+	if (sock_flag(sk, SOCK_DEAD) ||
+	    !(sk->sk_state & PPPOX_CONNECTED) || !dev)
+		return -ENODEV;
+
+	path->dev = po->pppoe_dev;
+	path->flags |= FLOW_OFFLOAD_PATH_PPPOE;
+	memcpy(path->eth_src, po->pppoe_dev->dev_addr, ETH_ALEN);
+	memcpy(path->eth_dest, po->pppoe_pa.remote, ETH_ALEN);
+	path->pppoe_sid = be16_to_cpu(po->num);
+
+	if (path->dev->netdev_ops->ndo_flow_offload_check)
+		return path->dev->netdev_ops->ndo_flow_offload_check(path);
+
+	return 0;
+}
+#endif /* CONFIG_NF_FLOW_TABLE */
+
 static const struct ppp_channel_ops pppoe_chan_ops = {
 	.start_xmit = pppoe_xmit,
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+	.flow_offload_check = pppoe_flow_offload_check,
+#endif
 };
 
 static int pppoe_recvmsg(struct socket *sock, struct msghdr *m,
--- a/include/linux/ppp_channel.h
+++ b/include/linux/ppp_channel.h
@@ -28,6 +28,10 @@ struct ppp_channel_ops {
 	int	(*start_xmit)(struct ppp_channel *, struct sk_buff *);
 	/* Handle an ioctl call that has come in via /dev/ppp. */
 	int	(*ioctl)(struct ppp_channel *, unsigned int, unsigned long);
+
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+	int	(*flow_offload_check)(struct ppp_channel *, struct flow_offload_hw_path *);
+#endif
 };
 
 struct ppp_channel {