[PATCH nf-next v2 2/3] nf_flow_table_offload: offload the PPPoE encap in the flowtable

[wenxu@xxxxxxxxxxxxxxx]

From: wenxu <wenxu@xxxxxxxxxxxxxxx>

This patch put the pppoe process in the FLOW_OFFLOAD_XMIT_DIRECT
mode. Xmit the packet with PPPoE can offload to the underlay device
directly.

It can support all kinds of VLAN dev path:
pppoe-->eth
pppoe-->br0.100-->br0(vlan filter enable)-->eth
pppoe-->eth.100-->eth

The packet xmit and recv offload to the 'eth' in both original and
reply direction.

Signed-off-by: wenxu <wenxu@xxxxxxxxxxxxxxx>
---
 include/net/netfilter/nf_flow_table.h | 34 ++++++++++++++++++++++++++++++++++
 net/netfilter/nf_flow_table_ip.c      |  3 +++
 net/netfilter/nft_flow_offload.c      | 11 +++--------
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 64daafd..a0b310e 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -319,6 +319,40 @@ int nf_flow_rule_route_ipv6(struct net *net, const struct flow_offload *flow,
 int nf_flow_table_offload_init(void);
 void nf_flow_table_offload_exit(void);
 
+static inline int nf_flow_ppoe_push(struct sk_buff *skb, u16 id)
+{
+	struct ppp_hdr {
+		struct pppoe_hdr hdr;
+		__be16 proto;
+	} *ph;
+	int data_len = skb->len + 2;
+	__be16 proto;
+
+	if (skb_cow_head(skb, PPPOE_SES_HLEN))
+		return -1;
+
+	if (skb->protocol == htons(ETH_P_IP))
+		proto = htons(PPP_IP);
+	else if (skb->protocol == htons(ETH_P_IPV6))
+		proto = htons(PPP_IPV6);
+	else
+		return -1;
+
+	__skb_push(skb, PPPOE_SES_HLEN);
+	skb_reset_network_header(skb);
+
+	ph = (struct ppp_hdr *)(skb->data);
+	ph->hdr.ver  = 1;
+	ph->hdr.type = 1;
+	ph->hdr.code = 0;
+	ph->hdr.sid  = htons(id);
+	ph->hdr.length = htons(data_len);
+	ph->proto = proto;
+	skb->protocol = htons(ETH_P_PPP_SES);
+
+	return 0;
+}
+
 static inline __be16 nf_flow_pppoe_proto(const struct sk_buff *skb)
 {
 	__be16 proto;
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 5da651d..a0c640e 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -304,6 +304,9 @@ static void nf_flow_encap_push(struct sk_buff *skb,
 				      tuplehash->tuple.encap[i].proto,
 				      tuplehash->tuple.encap[i].id);
 			break;
+		case htons(ETH_P_PPP_SES):
+			nf_flow_ppoe_push(skb, tuplehash->tuple.encap[i].id);
+			break;
 		}
 	}
 }
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index bfe7a3a..9296a1f 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -126,13 +126,9 @@ static void nft_dev_path_info(const struct net_device_path_stack *stack,
 			info->encap[info->num_encaps].id = path->encap.id;
 			info->encap[info->num_encaps].proto = path->encap.proto;
 			info->num_encaps++;
-			if (path->type == DEV_PATH_PPPOE) {
-				if (!info->outdev)
-					info->outdev = path->dev;
+			if (path->type == DEV_PATH_PPPOE)
 				memcpy(info->h_dest, path->encap.h_dest, ETH_ALEN);
-			}
-			if (path->type == DEV_PATH_VLAN)
-				info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
+			info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
 			break;
 		case DEV_PATH_BRIDGE:
 			if (is_zero_ether_addr(info->h_source))
@@ -160,8 +156,7 @@ static void nft_dev_path_info(const struct net_device_path_stack *stack,
 			break;
 		}
 	}
-	if (!info->outdev)
-		info->outdev = info->indev;
+	info->outdev = info->indev;
 
 	info->hw_outdev = info->indev;
 
-- 
1.8.3.1