bpf: Omit superfluous address family check in __bpf_skc_lookup

family is only set to either AF_INET or AF_INET6 based on len. In all
other cases we return early. Thus the check against AF_UNSPEC can be
omitted.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220630082618.15649-1-tklauser@distanz.ch

diff --git a/net/core/filter.c b/net/core/filter.c
index c6941ab0eb52d7d98a1cdb0591acb1d9e12d8795..4fae919843592a16e51d92cf1bd1491df012bdd4 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6516,8 +6516,8 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
                 u64 flags)
 {
        struct sock *sk = NULL;
-       u8 family = AF_UNSPEC;
        struct net *net;
+       u8 family;
        int sdif;
 
        if (len == sizeof(tuple->ipv4))
@@ -6527,8 +6527,7 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
        else
                return NULL;
 
-       if (unlikely(family == AF_UNSPEC || flags ||
-                    !((s32)netns_id < 0 || netns_id <= S32_MAX)))
+       if (unlikely(flags || !((s32)netns_id < 0 || netns_id <= S32_MAX)))
                goto out;
 
        if (family == AF_INET)