gre: Create common functions for transmit

Create common functions for both IPv4 and IPv6 GRE in transmit. These
are put into gre.h.

Common functions are for:
  - GRE checksum calculation. Move gre_checksum to gre.h.
  - Building a GRE header. Move GRE build_header and rename
    gre_build_header.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2016-04-29 17:12:19 -07:00 committed by David S. Miller
parent 8eb30be035
commit 182a352d2d
2 changed files with 49 additions and 47 deletions

View File

@ -85,4 +85,48 @@ static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)
return flags;
}
static inline __sum16 gre_checksum(struct sk_buff *skb)
{
__wsum csum;
if (skb->ip_summed == CHECKSUM_PARTIAL)
csum = lco_csum(skb);
else
csum = skb_checksum(skb, 0, skb->len, 0);
return csum_fold(csum);
}
static inline void gre_build_header(struct sk_buff *skb, int hdr_len,
__be16 flags, __be16 proto,
__be32 key, __be32 seq)
{
struct gre_base_hdr *greh;
skb_push(skb, hdr_len);
skb_reset_transport_header(skb);
greh = (struct gre_base_hdr *)skb->data;
greh->flags = gre_tnl_flags_to_gre_flags(flags);
greh->protocol = proto;
if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
if (flags & TUNNEL_SEQ) {
*ptr = seq;
ptr--;
}
if (flags & TUNNEL_KEY) {
*ptr = key;
ptr--;
}
if (flags & TUNNEL_CSUM &&
!(skb_shinfo(skb)->gso_type &
(SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
*ptr = 0;
*(__sum16 *)ptr = gre_checksum(skb);
}
}
}
#endif

View File

@ -329,49 +329,6 @@ drop:
return 0;
}
static __sum16 gre_checksum(struct sk_buff *skb)
{
__wsum csum;
if (skb->ip_summed == CHECKSUM_PARTIAL)
csum = lco_csum(skb);
else
csum = skb_checksum(skb, 0, skb->len, 0);
return csum_fold(csum);
}
static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
__be16 proto, __be32 key, __be32 seq)
{
struct gre_base_hdr *greh;
skb_push(skb, hdr_len);
skb_reset_transport_header(skb);
greh = (struct gre_base_hdr *)skb->data;
greh->flags = gre_tnl_flags_to_gre_flags(flags);
greh->protocol = proto;
if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
if (flags & TUNNEL_SEQ) {
*ptr = seq;
ptr--;
}
if (flags & TUNNEL_KEY) {
*ptr = key;
ptr--;
}
if (flags & TUNNEL_CSUM &&
!(skb_shinfo(skb)->gso_type &
(SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
*ptr = 0;
*(__sum16 *)ptr = gre_checksum(skb);
}
}
}
static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
const struct iphdr *tnl_params,
__be16 proto)
@ -382,8 +339,9 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
tunnel->o_seqno++;
/* Push GRE header. */
build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
proto, tunnel->parms.o_key, htonl(tunnel->o_seqno));
gre_build_header(skb, tunnel->tun_hlen,
tunnel->parms.o_flags, proto, tunnel->parms.o_key,
htonl(tunnel->o_seqno));
skb_set_inner_protocol(skb, proto);
ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
@ -460,8 +418,8 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
goto err_free_rt;
flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),
tunnel_id_to_key(tun_info->key.tun_id), 0);
gre_build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),
tunnel_id_to_key(tun_info->key.tun_id), 0);
df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;