net: erspan: refactor existing erspan code

The patch refactors the existing erspan implementation in order
to support erspan version 2, which has additional metadata.  So, in
stead of having one 'struct erspanhdr' holding erspan version 1,
breaks it into 'struct erspan_base_hdr' and 'struct erspan_metadata'.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 9 deletions

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 4562579797d1..1303d0c44c36 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -501,25 +501,32 @@ static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 			 struct tnl_ptk_info *tpi)
 {
+	struct erspan_base_hdr *ershdr;
+	struct erspan_metadata *pkt_md;
 	const struct ipv6hdr *ipv6h;
-	struct erspanhdr *ershdr;
 	struct ip6_tnl *tunnel;
-	__be32 index;
+	u8 ver;
 
 	ipv6h = ipv6_hdr(skb);
-	ershdr = (struct erspanhdr *)skb->data;
+	ershdr = (struct erspan_base_hdr *)skb->data;
 
 	if (unlikely(!pskb_may_pull(skb, sizeof(*ershdr))))
 		return PACKET_REJECT;
 
+	ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
 	tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
-	index = ershdr->md.index;
+	pkt_md = (struct erspan_metadata *)(ershdr + 1);
 
 	tunnel = ip6gre_tunnel_lookup(skb->dev,
 				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
 				      tpi->proto);
 	if (tunnel) {
-		if (__iptunnel_pull_header(skb, sizeof(*ershdr),
+		int len = erspan_hdr_len(ver);
+
+		if (unlikely(!pskb_may_pull(skb, len)))
+			return -ENOMEM;
+
+		if (__iptunnel_pull_header(skb, len,
 					   htons(ETH_P_TEB),
 					   false, false) < 0)
 			return PACKET_REJECT;
@@ -545,14 +552,14 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
 			if (!md)
 				return PACKET_REJECT;
 
-			md->index = index;
+			memcpy(md, pkt_md, sizeof(*md));
 			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
 			info->options_len = sizeof(*md);
 
 			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
 
 		} else {
-			tunnel->parms.index = ntohl(index);
+			tunnel->parms.index = ntohl(pkt_md->u.index);
 			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
 		}
 
@@ -921,7 +928,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 			goto tx_err;
 
 		erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
-				    ntohl(md->index), truncate, false);
+				    ntohl(md->u.index), truncate, false);
 
 	} else {
 		switch (skb->protocol) {
@@ -1657,7 +1664,7 @@ static int ip6erspan_tap_init(struct net_device *dev)
 
 	tunnel->tun_hlen = 8;
 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
-		       sizeof(struct erspanhdr);
+		       sizeof(struct erspan_base_hdr) + ERSPAN_V1_MDSIZE;
 	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
 
 	dev->hard_header_len = LL_MAX_HEADER + t_hlen;