bpf: Change bpf_setsockopt(SOL_IPV6) to reuse do_ipv6_setsockopt()

After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IPV6)
and reuses the implementation in do_ipv6_setsockopt().

ipv6 could be compiled as a module.  Like how other code solved it
with stubs in ipv6_stubs.h, this patch adds the do_ipv6_setsockopt
to the ipv6_bpf_stub.

The current bpf_setsockopt(IPV6_TCLASS) does not take the
INET_ECN_MASK into the account for tcp.  The
do_ipv6_setsockopt(IPV6_TCLASS) will handle it correctly.

The existing optname white-list is refactored into a new
function sol_ipv6_setsockopt().

After this last SOL_IPV6 dup code removal, the __bpf_setsockopt()
is simplified enough that the extra "{ }" around the if statement
can be removed.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061834.4181198-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 45e0339be6fa..8692698b01cf 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -81,6 +81,8 @@ struct ipv6_bpf_stub {
 				     const struct in6_addr *daddr, __be16 dport,
 				     int dif, int sdif, struct udp_table *tbl,
 				     struct sk_buff *skb);
+	int (*ipv6_setsockopt)(struct sock *sk, int level, int optname,
+			       sockptr_t optval, unsigned int optlen);
 };
 extern const struct ipv6_bpf_stub *ipv6_bpf_stub __read_mostly;