bpf: support flow label for bpf_skb_{set, get}_tunnel_key
This patch extends bpf_tunnel_key with a tunnel_label member, that maps
to ip_tunnel_key's label so underlying backends like vxlan and geneve
can propagate the label to udp_tunnel6_xmit_skb(), where it's being set
in the IPv6 header. It allows for having 20 more bits to encode/decode
flow related meta information programmatically. Tested with vxlan and
geneve.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/filter.c b/net/core/filter.c
index a66dc03..6fc3893 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1770,12 +1770,15 @@
return -EPROTO;
if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
switch (size) {
+ case offsetof(struct bpf_tunnel_key, tunnel_label):
+ goto set_compat;
case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
/* Fixup deprecated structure layouts here, so we have
* a common path later on.
*/
if (ip_tunnel_info_af(info) != AF_INET)
return -EINVAL;
+set_compat:
to = (struct bpf_tunnel_key *)compat;
break;
default:
@@ -1787,11 +1790,13 @@
to->tunnel_tos = info->key.tos;
to->tunnel_ttl = info->key.ttl;
- if (flags & BPF_F_TUNINFO_IPV6)
+ if (flags & BPF_F_TUNINFO_IPV6) {
memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
sizeof(to->remote_ipv6));
- else
+ to->tunnel_label = be32_to_cpu(info->key.label);
+ } else {
to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
+ }
if (unlikely(size != sizeof(struct bpf_tunnel_key)))
memcpy((void *)(long) r2, to, size);
@@ -1850,6 +1855,7 @@
return -EINVAL;
if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
switch (size) {
+ case offsetof(struct bpf_tunnel_key, tunnel_label):
case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
/* Fixup deprecated structure layouts here, so we have
* a common path later on.
@@ -1862,6 +1868,8 @@
return -EINVAL;
}
}
+ if (unlikely(!(flags & BPF_F_TUNINFO_IPV6) && from->tunnel_label))
+ return -EINVAL;
skb_dst_drop(skb);
dst_hold((struct dst_entry *) md);
@@ -1882,6 +1890,8 @@
info->mode |= IP_TUNNEL_INFO_IPV6;
memcpy(&info->key.u.ipv6.dst, from->remote_ipv6,
sizeof(from->remote_ipv6));
+ info->key.label = cpu_to_be32(from->tunnel_label) &
+ IPV6_FLOWLABEL_MASK;
} else {
info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
if (flags & BPF_F_ZERO_CSUM_TX)