net: ipv6: add second dif to inet6 socket lookups

Add a second device index, sdif, to inet6 socket lookups. sdif is the
index for ingress devices enslaved to an l3mdev. It allows the lookups
to consider the enslaved device as well as the L3 domain when searching
for a socket.

TCP moves the data in the cb. Prior to tcp_v4_rcv (e.g., early demux) the
ingress index is obtained from IPCB using inet_sdif and after tcp_v4_rcv
tcp_v4_sdif is used.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 23 insertions, 9 deletions

diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index b87becacd9d3..6e91e38a31da 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -49,7 +49,8 @@ struct sock *__inet6_lookup_established(struct net *net,
 					const struct in6_addr *saddr,
 					const __be16 sport,
 					const struct in6_addr *daddr,
-					const u16 hnum, const int dif);
+					const u16 hnum, const int dif,
+					const int sdif);
 
 struct sock *inet6_lookup_listener(struct net *net,
 				   struct inet_hashinfo *hashinfo,
@@ -57,7 +58,8 @@ struct sock *inet6_lookup_listener(struct net *net,
 				   const struct in6_addr *saddr,
 				   const __be16 sport,
 				   const struct in6_addr *daddr,
-				   const unsigned short hnum, const int dif);
+				   const unsigned short hnum,
+				   const int dif, const int sdif);
 
 static inline struct sock *__inet6_lookup(struct net *net,
 					  struct inet_hashinfo *hashinfo,
@@ -66,24 +68,25 @@ static inline struct sock *__inet6_lookup(struct net *net,
 					  const __be16 sport,
 					  const struct in6_addr *daddr,
 					  const u16 hnum,
-					  const int dif,
+					  const int dif, const int sdif,
 					  bool *refcounted)
 {
 	struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr,
-						sport, daddr, hnum, dif);
+						     sport, daddr, hnum,
+						     dif, sdif);
 	*refcounted = true;
 	if (sk)
 		return sk;
 	*refcounted = false;
 	return inet6_lookup_listener(net, hashinfo, skb, doff, saddr, sport,
-				     daddr, hnum, dif);
+				     daddr, hnum, dif, sdif);
 }
 
 static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
 					      struct sk_buff *skb, int doff,
 					      const __be16 sport,
 					      const __be16 dport,
-					      int iif,
+					      int iif, int sdif,
 					      bool *refcounted)
 {
 	struct sock *sk = skb_steal_sock(skb);
@@ -95,7 +98,7 @@ static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
 	return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo, skb,
 			      doff, &ipv6_hdr(skb)->saddr, sport,
 			      &ipv6_hdr(skb)->daddr, ntohs(dport),
-			      iif, refcounted);
+			      iif, sdif, refcounted);
 }
 
 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
@@ -107,13 +110,14 @@ struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
 int inet6_hash(struct sock *sk);
 #endif /* IS_ENABLED(CONFIG_IPV6) */
 
-#define INET6_MATCH(__sk, __net, __saddr, __daddr, __ports, __dif)	\
+#define INET6_MATCH(__sk, __net, __saddr, __daddr, __ports, __dif, __sdif) \
 	(((__sk)->sk_portpair == (__ports))			&&	\
 	 ((__sk)->sk_family == AF_INET6)			&&	\
 	 ipv6_addr_equal(&(__sk)->sk_v6_daddr, (__saddr))		&&	\
 	 ipv6_addr_equal(&(__sk)->sk_v6_rcv_saddr, (__daddr))	&&	\
 	 (!(__sk)->sk_bound_dev_if	||				\
-	   ((__sk)->sk_bound_dev_if == (__dif))) 		&&	\
+	   ((__sk)->sk_bound_dev_if == (__dif))	||			\
+	   ((__sk)->sk_bound_dev_if == (__sdif)))		&&	\
 	 net_eq(sock_net(__sk), (__net)))
 
 #endif /* _INET6_HASHTABLES_H */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 2b89f1ab8552..999f3efe572b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -827,6 +827,16 @@ static inline int tcp_v6_iif(const struct sk_buff *skb)
 
 	return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif;
 }
+
+/* TCP_SKB_CB reference means this can not be used from early demux */
+static inline int tcp_v6_sdif(const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+	if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags))
+		return TCP_SKB_CB(skb)->header.h6.iif;
+#endif
+	return 0;
+}
 #endif
 
 /* TCP_SKB_CB reference means this can not be used from early demux */