net: remove sk_route_nocaps

Instead of using a full netdev_features_t, we can use a single bit,
as sk_route_nocaps is only used to remove NETIF_F_GSO_MASK from
sk->sk_route_cap.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -284,7 +284,7 @@ struct bpf_local_storage;
   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
   *	@sk_no_check_rx: allow zero checksum in RX packets
   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
-  *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
+  *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
   *	@sk_gso_max_size: Maximum GSO segment size to build
   *	@sk_gso_max_segs: Maximum number of GSO segments
@@ -458,7 +458,6 @@ struct sock {
 	unsigned long		sk_max_pacing_rate;
 	struct page_frag	sk_frag;
 	netdev_features_t	sk_route_caps;
-	netdev_features_t	sk_route_nocaps;
 	int			sk_gso_type;
 	unsigned int		sk_gso_max_size;
 	gfp_t			sk_allocation;
@@ -468,7 +467,7 @@ struct sock {
 	 * Because of non atomicity rules, all
 	 * changes are protected by socket lock.
 	 */
-	u8			sk_padding : 1,
+	u8			sk_gso_disabled : 1,
 				sk_kern_sock : 1,
 				sk_no_check_tx : 1,
 				sk_no_check_rx : 1,
@@ -2121,10 +2120,10 @@ static inline bool sk_can_gso(const struct sock *sk)
 
 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
 
-static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
+static inline void sk_gso_disable(struct sock *sk)
 {
-	sk->sk_route_nocaps |= flags;
+	sk->sk_gso_disabled = 1;
-	sk->sk_route_caps &= ~flags;
+	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 }
 
 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,

net/core/sock.c

@@ -2249,7 +2249,8 @@ void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
 		sk->sk_route_caps |= NETIF_F_GSO;
 	if (sk->sk_route_caps & NETIF_F_GSO)
 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
-	sk->sk_route_caps &= ~sk->sk_route_nocaps;
+	if (unlikely(sk->sk_gso_disabled))
+		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 	if (sk_can_gso(sk)) {
 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;

net/ipv4/tcp_ipv4.c

@@ -1182,7 +1182,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 		if (!md5sig)
 			return -ENOMEM;
 
-		sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+		sk_gso_disable(sk);
 		INIT_HLIST_HEAD(&md5sig->head);
 		rcu_assign_pointer(tp->md5sig_info, md5sig);
 	}
@@ -1620,7 +1620,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 		 */
 		tcp_md5_do_add(newsk, addr, AF_INET, 32, l3index, key->flags,
 			       key->key, key->keylen, GFP_ATOMIC);
-		sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
+		sk_gso_disable(newsk);
 	}
 #endif
 

net/ipv4/tcp_output.c

@@ -1359,7 +1359,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 #ifdef CONFIG_TCP_MD5SIG
 	/* Calculate the MD5 hash, as we have all we need now */
 	if (md5) {
-		sk_nocaps_add(sk, NETIF_F_GSO_MASK);
+		sk_gso_disable(sk);
 		tp->af_specific->calc_md5_hash(opts.hash_location,
 					       md5, sk, skb);
 	}

net/ipv6/ip6_output.c

@@ -977,7 +977,7 @@ slow_path:
 
 fail_toobig:
 	if (skb->sk && dst_allfrag(skb_dst(skb)))
-		sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
+		sk_gso_disable(skb->sk);
 
 	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 	err = -EMSGSIZE;