static void __gre_build_header(struct sk_buff *skb,
int tunnel_hlen,
bool is_gre64)
{
const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
__be32 *options = (__be32 *)(skb_network_header(skb) + tunnel_hlen
- GRE_HEADER_SECTION);
struct gre_base_hdr *greh = (struct gre_base_hdr *) skb_transport_header(skb);
greh->protocol = htons(ETH_P_TEB);
greh->flags = 0;
/* Work backwards over the options so the checksum is last. */
if (tun_key->tun_flags & OVS_TNL_F_KEY || is_gre64) {
greh->flags |= GRE_KEY;
if (is_gre64) {
/* Set higher 32 bits to seq. */
*options = be64_get_high32(tun_key->tun_id);
options--;
greh->flags |= GRE_SEQ;
}
*options = be64_get_low32(tun_key->tun_id);
options--;
}
if (tun_key->tun_flags & OVS_TNL_F_CSUM) {
greh->flags |= GRE_CSUM;
*options = 0;
*(__sum16 *)options = csum_fold(skb_checksum(skb,
skb_transport_offset(skb),
skb->len - skb_transport_offset(skb),
0));
}
}
static int bpf_dp_ctx_init(struct bpf_dp_context *ctx)
{
struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(ctx->skb)->tun_key;
if (skb_headroom(ctx->skb) < 64) {
if (pskb_expand_head(ctx->skb, 64, 0, GFP_ATOMIC))
return -ENOMEM;
}
ctx->context.length = ctx->skb->len;
ctx->context.vlan_tag = vlan_tx_tag_present(ctx->skb) ?
vlan_tx_tag_get(ctx->skb) : 0;
ctx->context.hw_csum = (ctx->skb->ip_summed == CHECKSUM_PARTIAL);
if (tun_key) {
ctx->context.tun_key.tun_id =
be32_to_cpu(be64_get_low32(tun_key->tun_id));
ctx->context.tun_key.src_ip = be32_to_cpu(tun_key->ipv4_src);
ctx->context.tun_key.dst_ip = be32_to_cpu(tun_key->ipv4_dst);
ctx->context.tun_key.tos = tun_key->ipv4_tos;
ctx->context.tun_key.ttl = tun_key->ipv4_ttl;
} else {
memset(&ctx->context.tun_key, 0,
sizeof(struct bpf_ipv4_tun_key));
}
return 0;
}
static struct sk_buff *__build_header(struct sk_buff *skb,
int tunnel_hlen)
{
const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->egress_tun_key;
struct tnl_ptk_info tpi;
skb = gre_handle_offloads(skb, !!(tun_key->tun_flags & TUNNEL_CSUM));
if (IS_ERR(skb))
return NULL;
tpi.flags = filter_tnl_flags(tun_key->tun_flags);
tpi.proto = htons(ETH_P_TEB);
tpi.key = be64_get_low32(tun_key->tun_id);
tpi.seq = 0;
gre_build_header(skb, &tpi, tunnel_hlen);
return skb;
}
