This patch builds on top of the previous patch in the patchset,
which added BPF_LWT_ENCAP_IP mode to bpf_lwt_push_encap. As the
encapping can result in the skb needing to go via a different
interface/route/dst, bpf programs can indicate this by returning
BPF_LWT_REROUTE, which triggers a new route lookup for the skb.
v8 changes: fix kbuild errors when LWTUNNEL_BPF is builtin, but
IPV6 is a module: as LWTUNNEL_BPF can only be either Y or N,
call IPV6 routing functions only if they are built-in.
v9 changes:
- fixed a kbuild test robot compiler warning;
- call IPV6 routing functions via ipv6_stub.
v10 changes: removed unnecessary IS_ENABLED and pr_warn_once.
v11 changes: fixed a potential dst leak.
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
3bd0b15281