--- zzzz-none-000/linux-4.9.279/net/ipv6/udp.c	2021-08-08 06:38:54.000000000 +0000
+++ puma7-atom-6591-750/linux-4.9.279/net/ipv6/udp.c	2023-02-08 11:43:43.000000000 +0000
@@ -20,6 +20,10 @@
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  */
+/*
+ * Includes Intel Corporation's changes/modifications dated: 2018.
+ * Changed/modified portions - Copyright 2018, Intel Corporation.
+ */
 
 #include <linux/errno.h>
 #include <linux/types.h>
@@ -46,6 +50,7 @@
 #include <net/tcp_states.h>
 #include <net/ip6_checksum.h>
 #include <net/xfrm.h>
+#include <net/inet_hashtables.h>
 #include <net/inet6_hashtables.h>
 #include <net/busy_poll.h>
 #include <net/sock_reuseport.h>
@@ -55,6 +60,8 @@
 #include <trace/events/skb.h>
 #include "udp_impl.h"
 
+#include <avm/pa/avm_pa.h>
+
 static u32 udp6_ehashfn(const struct net *net,
 			const struct in6_addr *laddr,
 			const u16 lport,
@@ -277,11 +284,7 @@
 					  struct udp_table *udptable)
 {
 	const struct ipv6hdr *iph = ipv6_hdr(skb);
-	struct sock *sk;
 
-	sk = skb_steal_sock(skb);
-	if (unlikely(sk))
-		return sk;
 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 				 &iph->daddr, dport, inet6_iif(skb),
 				 udptable, skb);
@@ -557,12 +560,15 @@
 int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct udp_sock *up = udp_sk(sk);
+	struct net *net = dev_net(skb->dev);
 	int rc;
 	int is_udplite = IS_UDPLITE(sk);
 
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto drop;
 
+	avm_pa_add_local_session(AVM_PA_NET_IP6_DEVINFO(net), skb, sk);
+
 	if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 
@@ -799,6 +805,24 @@
 	if (udp6_csum_init(skb, uh, proto))
 		goto csum_error;
 
+	/* Check if the socket is already available, e.g. due to early demux */
+	sk = skb_steal_sock(skb);
+	if (sk) {
+		struct dst_entry *dst = skb_dst(skb);
+		int ret;
+
+		if (unlikely(sk->sk_rx_dst != dst))
+			udp_sk_rx_dst_set(sk, dst);
+
+		ret = udpv6_queue_rcv_skb(sk, skb);
+		sock_put(sk);
+
+		/* a return value > 0 means to resubmit the input */
+		if (ret > 0)
+			return ret;
+		return 0;
+	}
+
 	/*
 	 *	Multicast receive code
 	 */
@@ -807,11 +831,6 @@
 				saddr, daddr, udptable, proto);
 
 	/* Unicast */
-
-	/*
-	 * check socket cache ... must talk to Alan about his plans
-	 * for sock caches... i'll skip this for now.
-	 */
 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 	if (sk) {
 		int ret;
@@ -866,6 +885,71 @@
 	return 0;
 }
 
+static struct sock *__udp6_lib_demux_lookup(struct net *net,
+			__be16 loc_port, const struct in6_addr *loc_addr,
+			__be16 rmt_port, const struct in6_addr *rmt_addr,
+			int dif)
+{
+	unsigned short hnum = ntohs(loc_port);
+	unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum);
+	unsigned int slot2 = hash2 & udp_table.mask;
+	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
+	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
+	struct sock *sk;
+	bool scan_limit = !toe_udp_early_demux_no_scan_limit;
+
+	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
+		if (sk->sk_state == TCP_ESTABLISHED &&
+		    INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif))
+			return sk;
+		if (scan_limit)
+			/* Only check first socket in chain */
+			break;
+	}
+	return NULL;
+}
+
+static void udp_v6_early_demux(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb->dev);
+	const struct udphdr *uh;
+	struct sock *sk;
+	struct dst_entry *dst;
+	int dif = skb->dev->ifindex;
+
+	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
+	    sizeof(struct udphdr)))
+		return;
+
+	uh = udp_hdr(skb);
+
+	if (skb->pkt_type == PACKET_HOST)
+		sk = __udp6_lib_demux_lookup(net, uh->dest,
+					     &ipv6_hdr(skb)->daddr,
+					     uh->source, &ipv6_hdr(skb)->saddr,
+					     dif);
+	else
+		return;
+
+	if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
+		return;
+
+	skb->sk = sk;
+	skb->destructor = sock_efree;
+	dst = READ_ONCE(sk->sk_rx_dst);
+
+	if (dst)
+		dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
+	if (dst) {
+		if (dst->flags & DST_NOCACHE) {
+			if (likely(atomic_inc_not_zero(&dst->__refcnt)))
+				skb_dst_set(skb, dst);
+		} else {
+			skb_dst_set_noref(skb, dst);
+		}
+	}
+}
+
 static __inline__ int udpv6_rcv(struct sk_buff *skb)
 {
 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
@@ -1162,6 +1246,7 @@
 		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 
 	fl6.flowi6_mark = sk->sk_mark;
+	fl6.flowi6_uid = sk->sk_uid;
 
 	if (msg->msg_controllen) {
 		opt = &opt_space;
@@ -1383,6 +1468,7 @@
 #endif
 
 static const struct inet6_protocol udpv6_protocol = {
+	.early_demux	=	udp_v6_early_demux,
 	.handler	=	udpv6_rcv,
 	.err_handler	=	udpv6_err,
 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,