ip_gre: Refector the erpsan tunnel code.
Move two erspan functions to header file, erspan.h, so ipv6
erspan implementation can use it.
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/erspan.h b/include/net/erspan.h
index ca94fc8..6e758d0 100644
--- a/include/net/erspan.h
+++ b/include/net/erspan.h
@@ -58,4 +58,55 @@ struct erspanhdr {
struct erspan_metadata md;
};
+static inline u8 tos_to_cos(u8 tos)
+{
+ u8 dscp, cos;
+
+ dscp = tos >> 2;
+ cos = dscp >> 3;
+ return cos;
+}
+
+static inline void erspan_build_header(struct sk_buff *skb,
+ __be32 id, u32 index,
+ bool truncate, bool is_ipv4)
+{
+ struct ethhdr *eth = eth_hdr(skb);
+ enum erspan_encap_type enc_type;
+ struct erspanhdr *ershdr;
+ struct qtag_prefix {
+ __be16 eth_type;
+ __be16 tci;
+ } *qp;
+ u16 vlan_tci = 0;
+ u8 tos;
+
+ tos = is_ipv4 ? ip_hdr(skb)->tos :
+ (ipv6_hdr(skb)->priority << 4) +
+ (ipv6_hdr(skb)->flow_lbl[0] >> 4);
+
+ enc_type = ERSPAN_ENCAP_NOVLAN;
+
+ /* If mirrored packet has vlan tag, extract tci and
+ * perserve vlan header in the mirrored frame.
+ */
+ if (eth->h_proto == htons(ETH_P_8021Q)) {
+ qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
+ vlan_tci = ntohs(qp->tci);
+ enc_type = ERSPAN_ENCAP_INFRAME;
+ }
+
+ skb_push(skb, sizeof(*ershdr));
+ ershdr = (struct erspanhdr *)skb->data;
+ memset(ershdr, 0, sizeof(*ershdr));
+
+ ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
+ (ERSPAN_VERSION << VER_OFFSET));
+ ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) |
+ ((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
+ (enc_type << EN_OFFSET & EN_MASK) |
+ ((truncate << T_OFFSET) & T_MASK));
+ ershdr->md.index = htonl(index & INDEX_MASK);
+}
+
#endif