static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
{
struct iphdr *nh;
int err;
err = make_writable(skb, skb_network_offset(skb) +
sizeof(struct iphdr));
if (unlikely(err))
return err;
nh = ip_hdr(skb);
if (ipv4_key->ipv4_src != nh->saddr)
set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
if (ipv4_key->ipv4_dst != nh->daddr)
set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
if (ipv4_key->ipv4_tos != nh->tos)
ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
if (ipv4_key->ipv4_ttl != nh->ttl)
set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
return 0;
}
//Clear ECN marking
inline void clear_ecn(struct sk_buff *skb)
{
struct iphdr *iph=ip_hdr(skb);
if(likely(iph!=NULL))
{
if(skb_make_writable(skb, sizeof(struct iphdr)))
{
ipv4_change_dsfield(iph, 0xff, iph->tos & ~0x3);
}
}
}
static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
struct ipv6hdr *ipv6h,
struct sk_buff *skb)
{
__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
if (INET_ECN_is_ce(dsfield))
IP_ECN_set_ce(ip_hdr(skb));
}