1 files changed, 111 insertions, 69 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 37b0699e95e5..f05099fc5901 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -103,7 +103,7 @@ int udp_v6_get_port(struct sock *sk, unsigned short snum)
 {
 	unsigned int hash2_nulladdr =
 		udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
-	unsigned int hash2_partial = 
+	unsigned int hash2_partial =
 		udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
 
 	/* precompute partial secondary hash */
@@ -349,7 +349,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
 	bool slow;
 
 	if (addr_len)
-		*addr_len=sizeof(struct sockaddr_in6);
+		*addr_len = sizeof(struct sockaddr_in6);
 
 	if (flags & MSG_ERRQUEUE)
 		return ipv6_recv_error(sk, msg, len);
@@ -496,6 +496,28 @@ out:
 	sock_put(sk);
 }
 
+static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	int rc;
+
+	if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
+		sock_rps_save_rxhash(sk, skb);
+
+	rc = sock_queue_rcv_skb(sk, skb);
+	if (rc < 0) {
+		int is_udplite = IS_UDPLITE(sk);
+
+		/* Note that an ENOMEM error is charged twice */
+		if (rc == -ENOMEM)
+			UDP6_INC_STATS_BH(sock_net(sk),
+					UDP_MIB_RCVBUFERRORS, is_udplite);
+		UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+		kfree_skb(skb);
+		return -1;
+	}
+	return 0;
+}
+
 static __inline__ void udpv6_err(struct sk_buff *skb,
 				 struct inet6_skb_parm *opt, u8 type,
 				 u8 code, int offset, __be32 info     )
@@ -503,18 +525,54 @@ static __inline__ void udpv6_err(struct sk_buff *skb,
 	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 }
 
-int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+static struct static_key udpv6_encap_needed __read_mostly;
+void udpv6_encap_enable(void)
+{
+	if (!static_key_enabled(&udpv6_encap_needed))
+		static_key_slow_inc(&udpv6_encap_needed);
+}
+EXPORT_SYMBOL(udpv6_encap_enable);
+
+int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int rc;
 	int is_udplite = IS_UDPLITE(sk);
 
-	if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
-		sock_rps_save_rxhash(sk, skb);
-
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto drop;
 
+	if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
+		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
+
+		/*
+		 * This is an encapsulation socket so pass the skb to
+		 * the socket's udp_encap_rcv() hook. Otherwise, just
+		 * fall through and pass this up the UDP socket.
+		 * up->encap_rcv() returns the following value:
+		 * =0 if skb was successfully passed to the encap
+		 *    handler or was discarded by it.
+		 * >0 if skb should be passed on to UDP.
+		 * <0 if skb should be resubmitted as proto -N
+		 */
+
+		/* if we're overly short, let UDP handle it */
+		encap_rcv = ACCESS_ONCE(up->encap_rcv);
+		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
+			int ret;
+
+			ret = encap_rcv(sk, skb);
+			if (ret <= 0) {
+				UDP_INC_STATS_BH(sock_net(sk),
+						 UDP_MIB_INDATAGRAMS,
+						 is_udplite);
+				return -ret;
+			}
+		}
+
+		/* FALLTHROUGH -- it's a UDP Packet */
+	}
+
 	/*
 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 	 */
@@ -539,21 +597,25 @@ int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
 			goto drop;
 	}
 
+	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
+		goto drop;
+
 	skb_dst_drop(skb);
-	rc = sock_queue_rcv_skb(sk, skb);
-	if (rc < 0) {
-		/* Note that an ENOMEM error is charged twice */
-		if (rc == -ENOMEM)
-			UDP6_INC_STATS_BH(sock_net(sk),
-					UDP_MIB_RCVBUFERRORS, is_udplite);
-		goto drop_no_sk_drops_inc;
+
+	bh_lock_sock(sk);
+	rc = 0;
+	if (!sock_owned_by_user(sk))
+		rc = __udpv6_queue_rcv_skb(sk, skb);
+	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
+		bh_unlock_sock(sk);
+		goto drop;
 	}
+	bh_unlock_sock(sk);
 
-	return 0;
+	return rc;
 drop:
-	atomic_inc(&sk->sk_drops);
-drop_no_sk_drops_inc:
 	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+	atomic_inc(&sk->sk_drops);
 	kfree_skb(skb);
 	return -1;
 }
@@ -602,37 +664,27 @@ static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
 static void flush_stack(struct sock **stack, unsigned int count,
 			struct sk_buff *skb, unsigned int final)
 {
-	unsigned int i;
+	struct sk_buff *skb1 = NULL;
 	struct sock *sk;
-	struct sk_buff *skb1;
+	unsigned int i;
 
 	for (i = 0; i < count; i++) {
-		skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
-
 		sk = stack[i];
-		if (skb1) {
-			if (sk_rcvqueues_full(sk, skb1)) {
-				kfree_skb(skb1);
-				goto drop;
-			}
-			bh_lock_sock(sk);
-			if (!sock_owned_by_user(sk))
-				udpv6_queue_rcv_skb(sk, skb1);
-			else if (sk_add_backlog(sk, skb1)) {
-				kfree_skb(skb1);
-				bh_unlock_sock(sk);
-				goto drop;
-			}
-			bh_unlock_sock(sk);
-			continue;
+		if (likely(skb1 == NULL))
+			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
+		if (!skb1) {
+			atomic_inc(&sk->sk_drops);
+			UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+					  IS_UDPLITE(sk));
+			UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
+					  IS_UDPLITE(sk));
 		}
-drop:
-		atomic_inc(&sk->sk_drops);
-		UDP6_INC_STATS_BH(sock_net(sk),
-				UDP_MIB_RCVBUFERRORS, IS_UDPLITE(sk));
-		UDP6_INC_STATS_BH(sock_net(sk),
-				UDP_MIB_INERRORS, IS_UDPLITE(sk));
+
+		if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
+			skb1 = NULL;
 	}
+	if (unlikely(skb1))
+		kfree_skb(skb1);
 }
 /*
  * Note: called only from the BH handler context,
@@ -772,39 +824,29 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 	 * for sock caches... i'll skip this for now.
 	 */
 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
+	if (sk != NULL) {
+		int ret = udpv6_queue_rcv_skb(sk, skb);
+		sock_put(sk);
 
-	if (sk == NULL) {
-		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
-			goto discard;
-
-		if (udp_lib_checksum_complete(skb))
-			goto discard;
-		UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS,
-				proto == IPPROTO_UDPLITE);
-
-		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+		/* a return value > 0 means to resubmit the input, but
+		 * it wants the return to be -protocol, or 0
+		 */
+		if (ret > 0)
+			return -ret;
 
-		kfree_skb(skb);
 		return 0;
 	}
 
-	/* deliver */
-
-	if (sk_rcvqueues_full(sk, skb)) {
-		sock_put(sk);
+	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 		goto discard;
-	}
-	bh_lock_sock(sk);
-	if (!sock_owned_by_user(sk))
-		udpv6_queue_rcv_skb(sk, skb);
-	else if (sk_add_backlog(sk, skb)) {
-		atomic_inc(&sk->sk_drops);
-		bh_unlock_sock(sk);
-		sock_put(sk);
+
+	if (udp_lib_checksum_complete(skb))
 		goto discard;
-	}
-	bh_unlock_sock(sk);
-	sock_put(sk);
+
+	UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+	kfree_skb(skb);
 	return 0;
 
 short_packet:
@@ -1337,7 +1379,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 	 * do checksum of UDP packets sent as multiple IP fragments.
 	 */
 	offset = skb_checksum_start_offset(skb);
-	csum = skb_checksum(skb, offset, skb->len- offset, 0);
+	csum = skb_checksum(skb, offset, skb->len - offset, 0);
 	offset += skb->csum_offset;
 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
 	skb->ip_summed = CHECKSUM_NONE;
@@ -1471,7 +1513,7 @@ struct proto udpv6_prot = {
 	.getsockopt	   = udpv6_getsockopt,
 	.sendmsg	   = udpv6_sendmsg,
 	.recvmsg	   = udpv6_recvmsg,
-	.backlog_rcv	   = udpv6_queue_rcv_skb,
+	.backlog_rcv	   = __udpv6_queue_rcv_skb,
 	.hash		   = udp_lib_hash,
 	.unhash		   = udp_lib_unhash,
 	.rehash		   = udp_v6_rehash,