net: avoid sk_forward_alloc overflows

[firefly-linux-kernel-4.4.55.git] / include / net / dst_metadata.h

diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h
index 6816f0fa5693dc275e1e4997375f29b5d99f7b64..30a56ab2ccfb05d7bc9a527ebdc09da19b3d5f7b 100644 (file)
--- a/include/net/dst_metadata.h
+++ b/include/net/dst_metadata.h
@@ -44,6 +44,24 @@ static inline bool skb_valid_dst(const struct sk_buff *skb)
        return dst && !(dst->flags & DST_METADATA);
 }
 
+static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
+                                      const struct sk_buff *skb_b)
+{
+       const struct metadata_dst *a, *b;
+
+       if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
+               return 0;
+
+       a = (const struct metadata_dst *) skb_dst(skb_a);
+       b = (const struct metadata_dst *) skb_dst(skb_b);
+
+       if (!a != !b || a->u.tun_info.options_len != b->u.tun_info.options_len)
+               return 1;
+
+       return memcmp(&a->u.tun_info, &b->u.tun_info,
+                     sizeof(a->u.tun_info) + a->u.tun_info.options_len);
+}
+
 struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);