1 files changed, 115 insertions, 116 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 551fce49841d..2a3f9296df1e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -72,7 +72,7 @@ static void	tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
 static void	tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 				      struct request_sock *req);
 
-static int	tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
+INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
 
 static const struct inet_connection_sock_af_ops ipv6_mapped;
 const struct inet_connection_sock_af_ops ipv6_specific;
@@ -107,7 +107,7 @@ static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
 	if (dst && dst_hold_safe(dst)) {
 		const struct rt6_info *rt = (const struct rt6_info *)dst;
 
-		sk->sk_rx_dst = dst;
+		rcu_assign_pointer(sk->sk_rx_dst, dst);
 		sk->sk_rx_dst_ifindex = skb->skb_iif;
 		sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
 	}
@@ -146,17 +146,18 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 			  int addr_len)
 {
 	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
-	struct inet_sock *inet = inet_sk(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct in6_addr *saddr = NULL, *final_p, final;
+	struct inet_timewait_death_row *tcp_death_row;
 	struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+	struct inet_sock *inet = inet_sk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
-	struct in6_addr *saddr = NULL, *final_p, final;
+	struct net *net = sock_net(sk);
 	struct ipv6_txoptions *opt;
-	struct flowi6 fl6;
 	struct dst_entry *dst;
+	struct flowi6 fl6;
 	int addr_type;
 	int err;
-	struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
 
 	if (addr_len < SIN6_LEN_RFC2133)
 		return -EINVAL;
@@ -230,14 +231,15 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 		u32 exthdrlen = icsk->icsk_ext_hdr_len;
 		struct sockaddr_in sin;
 
-		if (__ipv6_only_sock(sk))
+		if (ipv6_only_sock(sk))
 			return -ENETUNREACH;
 
 		sin.sin_family = AF_INET;
 		sin.sin_port = usin->sin6_port;
 		sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 
-		icsk->icsk_af_ops = &ipv6_mapped;
+		/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
+		WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
 		if (sk_is_mptcp(sk))
 			mptcpv6_handle_mapped(sk, true);
 		sk->sk_backlog_rcv = tcp_v4_do_rcv;
@@ -249,7 +251,8 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 
 		if (err) {
 			icsk->icsk_ext_hdr_len = exthdrlen;
-			icsk->icsk_af_ops = &ipv6_specific;
+			/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
+			WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
 			if (sk_is_mptcp(sk))
 				mptcpv6_handle_mapped(sk, false);
 			sk->sk_backlog_rcv = tcp_v6_do_rcv;
@@ -280,15 +283,33 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 
 	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 
-	dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
+	dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
 	if (IS_ERR(dst)) {
 		err = PTR_ERR(dst);
 		goto failure;
 	}
 
+	tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
+
 	if (!saddr) {
+		struct inet_bind_hashbucket *prev_addr_hashbucket = NULL;
+		struct in6_addr prev_v6_rcv_saddr;
+
+		if (icsk->icsk_bind2_hash) {
+			prev_addr_hashbucket = inet_bhashfn_portaddr(tcp_death_row->hashinfo,
+								     sk, net, inet->inet_num);
+			prev_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
+		}
 		saddr = &fl6.saddr;
 		sk->sk_v6_rcv_saddr = *saddr;
+
+		if (prev_addr_hashbucket) {
+			err = inet_bhash2_update_saddr(prev_addr_hashbucket, sk);
+			if (err) {
+				sk->sk_v6_rcv_saddr = prev_v6_rcv_saddr;
+				goto failure;
+			}
+		}
 	}
 
 	/* set the source address */
@@ -321,8 +342,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 						    sk->sk_v6_daddr.s6_addr32,
 						    inet->inet_sport,
 						    inet->inet_dport));
-		tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk),
-						   np->saddr.s6_addr32,
+		tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
 						   sk->sk_v6_daddr.s6_addr32);
 	}
 
@@ -385,7 +405,7 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	bool fatal;
 	int err;
 
-	sk = __inet6_lookup_established(net, &tcp_hashinfo,
+	sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
 					&hdr->daddr, th->dest,
 					&hdr->saddr, ntohs(th->source),
 					skb->dev->ifindex, inet6_sdif(skb));
@@ -545,7 +565,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 		if (np->repflow && ireq->pktopts)
 			fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 
-		tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ?
+		tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
 				(tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
 				(np->tclass & INET_ECN_MASK) :
 				np->tclass;
@@ -772,57 +792,6 @@ clear_hash_noput:
 
 #endif
 
-static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
-				    const struct sk_buff *skb,
-				    int dif, int sdif)
-{
-#ifdef CONFIG_TCP_MD5SIG
-	const __u8 *hash_location = NULL;
-	struct tcp_md5sig_key *hash_expected;
-	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
-	const struct tcphdr *th = tcp_hdr(skb);
-	int genhash, l3index;
-	u8 newhash[16];
-
-	/* sdif set, means packet ingressed via a device
-	 * in an L3 domain and dif is set to the l3mdev
-	 */
-	l3index = sdif ? dif : 0;
-
-	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index);
-	hash_location = tcp_parse_md5sig_option(th);
-
-	/* We've parsed the options - do we have a hash? */
-	if (!hash_expected && !hash_location)
-		return false;
-
-	if (hash_expected && !hash_location) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
-		return true;
-	}
-
-	if (!hash_expected && hash_location) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
-		return true;
-	}
-
-	/* check the signature */
-	genhash = tcp_v6_md5_hash_skb(newhash,
-				      hash_expected,
-				      NULL, skb);
-
-	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
-		net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
-				     genhash ? "failed" : "mismatch",
-				     &ip6h->saddr, ntohs(th->source),
-				     &ip6h->daddr, ntohs(th->dest), l3index);
-		return true;
-	}
-#endif
-	return false;
-}
-
 static void tcp_v6_init_req(struct request_sock *req,
 			    const struct sock *sk_listener,
 			    struct sk_buff *skb)
@@ -891,7 +860,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 				 u32 ack, u32 win, u32 tsval, u32 tsecr,
 				 int oif, struct tcp_md5sig_key *key, int rst,
-				 u8 tclass, __be32 label, u32 priority)
+				 u8 tclass, __be32 label, u32 priority, u32 txhash)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct tcphdr *t1;
@@ -920,12 +889,11 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
 	}
 #endif
 
-	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
-			 GFP_ATOMIC);
+	buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
 	if (!buff)
 		return;
 
-	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
+	skb_reserve(buff, MAX_TCP_HEADER);
 
 	t1 = skb_push(buff, tot_len);
 	skb_reset_transport_header(buff);
@@ -983,15 +951,15 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
 	}
 
 	if (sk) {
-		if (sk->sk_state == TCP_TIME_WAIT) {
+		if (sk->sk_state == TCP_TIME_WAIT)
 			mark = inet_twsk(sk)->tw_mark;
-			/* autoflowlabel relies on buff->hash */
-			skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
-				     PKT_HASH_TYPE_L4);
-		} else {
+		else
 			mark = sk->sk_mark;
-		}
-		buff->tstamp = tcp_transmit_time(sk);
+		skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
+	}
+	if (txhash) {
+		/* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
+		skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
 	}
 	fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
 	fl6.fl6_dport = t1->dest;
@@ -1003,7 +971,10 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
 	 * Underlying function will use this to retrieve the network
 	 * namespace
 	 */
-	dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
+	if (sk && sk->sk_state != TCP_TIME_WAIT)
+		dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
+	else
+		dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
 	if (!IS_ERR(dst)) {
 		skb_dst_set(buff, dst);
 		ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
@@ -1032,6 +1003,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 	__be32 label = 0;
 	u32 priority = 0;
 	struct net *net;
+	u32 txhash = 0;
 	int oif = 0;
 
 	if (th->rst)
@@ -1067,11 +1039,10 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 		 * Incoming packet is checked with md5 hash with finding key,
 		 * no RST generated if md5 hash doesn't match.
 		 */
-		sk1 = inet6_lookup_listener(net,
-					   &tcp_hashinfo, NULL, 0,
-					   &ipv6h->saddr,
-					   th->source, &ipv6h->daddr,
-					   ntohs(th->source), dif, sdif);
+		sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
+					    NULL, 0, &ipv6h->saddr, th->source,
+					    &ipv6h->daddr, ntohs(th->source),
+					    dif, sdif);
 		if (!sk1)
 			goto out;
 
@@ -1105,10 +1076,12 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 			if (np->repflow)
 				label = ip6_flowlabel(ipv6h);
 			priority = sk->sk_priority;
+			txhash = sk->sk_hash;
 		}
 		if (sk->sk_state == TCP_TIME_WAIT) {
 			label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
 			priority = inet_twsk(sk)->tw_priority;
+			txhash = inet_twsk(sk)->tw_txhash;
 		}
 	} else {
 		if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
@@ -1116,7 +1089,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 	}
 
 	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
-			     ipv6_get_dsfield(ipv6h), label, priority);
+			     ipv6_get_dsfield(ipv6h), label, priority, txhash);
 
 #ifdef CONFIG_TCP_MD5SIG
 out:
@@ -1127,10 +1100,10 @@ out:
 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 			    u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 			    struct tcp_md5sig_key *key, u8 tclass,
-			    __be32 label, u32 priority)
+			    __be32 label, u32 priority, u32 txhash)
 {
 	tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
-			     tclass, label, priority);
+			     tclass, label, priority, txhash);
 }
 
 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
@@ -1142,7 +1115,8 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 			tcp_time_stamp_raw() + tcptw->tw_ts_offset,
 			tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
-			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
+			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
+			tw->tw_txhash);
 
 	inet_twsk_put(tw);
 }
@@ -1169,7 +1143,8 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 			tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
 			req->ts_recent, sk->sk_bound_dev_if,
 			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
-			ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority);
+			ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority,
+			tcp_rsk(req)->txhash);
 }
 
 
@@ -1365,7 +1340,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 	/* Set ToS of the new socket based upon the value of incoming SYN.
 	 * ECT bits are set later in tcp_init_transfer().
 	 */
-	if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)
+	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
 		newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
 
 	/* Clone native IPv6 options from listening socket (if any)
@@ -1466,10 +1441,12 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
  * This is because we cannot sleep with the original spinlock
  * held.
  */
-static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE
+int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	struct ipv6_pinfo *np = tcp_inet6_sk(sk);
 	struct sk_buff *opt_skb = NULL;
+	enum skb_drop_reason reason;
 	struct tcp_sock *tp;
 
 	/* Imagine: socket is IPv6. IPv4 packet arrives,
@@ -1504,8 +1481,12 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 	if (np->rxopt.all)
 		opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
 
+	reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
-		struct dst_entry *dst = sk->sk_rx_dst;
+		struct dst_entry *dst;
+
+		dst = rcu_dereference_protected(sk->sk_rx_dst,
+						lockdep_sock_is_held(sk));
 
 		sock_rps_save_rxhash(sk, skb);
 		sk_mark_napi_id(sk, skb);
@@ -1513,8 +1494,8 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 			if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
 			    INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
 					    dst, sk->sk_rx_dst_cookie) == NULL) {
+				RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
 				dst_release(dst);
-				sk->sk_rx_dst = NULL;
 			}
 		}
 
@@ -1554,9 +1535,10 @@ reset:
 discard:
 	if (opt_skb)
 		__kfree_skb(opt_skb);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 	return 0;
 csum_err:
+	reason = SKB_DROP_REASON_TCP_CSUM;
 	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
@@ -1622,6 +1604,7 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
 
 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 {
+	enum skb_drop_reason drop_reason;
 	int sdif = inet6_sdif(skb);
 	int dif = inet6_iif(skb);
 	const struct tcphdr *th;
@@ -1631,6 +1614,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 	int ret;
 	struct net *net = dev_net(skb->dev);
 
+	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (skb->pkt_type != PACKET_HOST)
 		goto discard_it;
 
@@ -1644,8 +1628,10 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 
 	th = (const struct tcphdr *)skb->data;
 
-	if (unlikely(th->doff < sizeof(struct tcphdr)/4))
+	if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
+		drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
 		goto bad_packet;
+	}
 	if (!pskb_may_pull(skb, th->doff*4))
 		goto discard_it;
 
@@ -1656,7 +1642,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 	hdr = ipv6_hdr(skb);
 
 lookup:
-	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
+	sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
 				th->source, th->dest, inet6_iif(skb), sdif,
 				&refcounted);
 	if (!sk)
@@ -1672,7 +1658,10 @@ process:
 		struct sock *nsk;
 
 		sk = req->rsk_listener;
-		if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) {
+		drop_reason = tcp_inbound_md5_hash(sk, skb,
+						   &hdr->saddr, &hdr->daddr,
+						   AF_INET6, dif, sdif);
+		if (drop_reason) {
 			sk_drops_add(sk, skb);
 			reqsk_put(req);
 			goto discard_it;
@@ -1701,6 +1690,8 @@ process:
 			hdr = ipv6_hdr(skb);
 			tcp_v6_fill_cb(skb, hdr, th);
 			nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+		} else {
+			drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
 		}
 		if (!nsk) {
 			reqsk_put(req);
@@ -1736,14 +1727,20 @@ process:
 		}
 	}
 
-	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
+	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
+		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		goto discard_and_relse;
+	}
 
-	if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
+	drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr,
+					   AF_INET6, dif, sdif);
+	if (drop_reason)
 		goto discard_and_relse;
 
-	if (tcp_filter(sk, skb))
+	if (tcp_filter(sk, skb)) {
+		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
 		goto discard_and_relse;
+	}
 	th = (const struct tcphdr *)skb->data;
 	hdr = ipv6_hdr(skb);
 	tcp_v6_fill_cb(skb, hdr, th);
@@ -1763,7 +1760,7 @@ process:
 	if (!sock_owned_by_user(sk)) {
 		ret = tcp_v6_do_rcv(sk, skb);
 	} else {
-		if (tcp_add_backlog(sk, skb))
+		if (tcp_add_backlog(sk, skb, &drop_reason))
 			goto discard_and_relse;
 	}
 	bh_unlock_sock(sk);
@@ -1773,6 +1770,7 @@ put_and_return:
 	return ret ? -1 : 0;
 
 no_tcp_socket:
+	drop_reason = SKB_DROP_REASON_NO_SOCKET;
 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 		goto discard_it;
 
@@ -1780,6 +1778,7 @@ no_tcp_socket:
 
 	if (tcp_checksum_complete(skb)) {
 csum_error:
+		drop_reason = SKB_DROP_REASON_TCP_CSUM;
 		trace_tcp_bad_csum(skb);
 		__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
 bad_packet:
@@ -1789,7 +1788,8 @@ bad_packet:
 	}
 
 discard_it:
-	kfree_skb(skb);
+	SKB_DR_OR(drop_reason, NOT_SPECIFIED);
+	kfree_skb_reason(skb, drop_reason);
 	return 0;
 
 discard_and_relse:
@@ -1800,6 +1800,7 @@ discard_and_relse:
 
 do_time_wait:
 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		inet_twsk_put(inet_twsk(sk));
 		goto discard_it;
 	}
@@ -1816,7 +1817,7 @@ do_time_wait:
 	{
 		struct sock *sk2;
 
-		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
+		sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
 					    skb, __tcp_hdrlen(th),
 					    &ipv6_hdr(skb)->saddr, th->source,
 					    &ipv6_hdr(skb)->daddr,
@@ -1847,8 +1848,9 @@ do_time_wait:
 	goto discard_it;
 }
 
-INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
+void tcp_v6_early_demux(struct sk_buff *skb)
 {
+	struct net *net = dev_net(skb->dev);
 	const struct ipv6hdr *hdr;
 	const struct tcphdr *th;
 	struct sock *sk;
@@ -1866,7 +1868,7 @@ INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
 		return;
 
 	/* Note : We use inet6_iif() here, not tcp_v6_iif() */
-	sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
+	sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
 					&hdr->saddr, th->source,
 					&hdr->daddr, ntohs(th->dest),
 					inet6_iif(skb), inet6_sdif(skb));
@@ -1874,7 +1876,7 @@ INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
 		skb->sk = sk;
 		skb->destructor = sock_edemux;
 		if (sk_fullsock(sk)) {
-			struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
+			struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
 
 			if (dst)
 				dst = dst_check(dst, sk->sk_rx_dst_cookie);
@@ -1893,9 +1895,7 @@ static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 
 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
 {
-	struct ipv6_pinfo *np = inet6_sk(sk);
-
-	__tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
+	__tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
 }
 
 const struct inet_connection_sock_af_ops ipv6_specific = {
@@ -2071,7 +2071,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
 		   jiffies_to_clock_t(icsk->icsk_rto),
 		   jiffies_to_clock_t(icsk->icsk_ack.ato),
 		   (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
-		   tp->snd_cwnd,
+		   tcp_snd_cwnd(tp),
 		   state == TCP_LISTEN ?
 			fastopenq->max_qlen :
 			(tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
@@ -2178,6 +2178,7 @@ struct proto tcpv6_prot = {
 	.hash			= inet6_hash,
 	.unhash			= inet_unhash,
 	.get_port		= inet_csk_get_port,
+	.put_port		= inet_put_port,
 #ifdef CONFIG_BPF_SYSCALL
 	.psock_update_sk_prot	= tcp_bpf_update_proto,
 #endif
@@ -2185,7 +2186,10 @@ struct proto tcpv6_prot = {
 	.leave_memory_pressure	= tcp_leave_memory_pressure,
 	.stream_memory_free	= tcp_stream_memory_free,
 	.sockets_allocated	= &tcp_sockets_allocated,
+
 	.memory_allocated	= &tcp_memory_allocated,
+	.per_cpu_fw_alloc	= &tcp_memory_per_cpu_fw_alloc,
+
 	.memory_pressure	= &tcp_memory_pressure,
 	.orphan_count		= &tcp_orphan_count,
 	.sysctl_mem		= sysctl_tcp_mem,
@@ -2196,18 +2200,13 @@ struct proto tcpv6_prot = {
 	.slab_flags		= SLAB_TYPESAFE_BY_RCU,
 	.twsk_prot		= &tcp6_timewait_sock_ops,
 	.rsk_prot		= &tcp6_request_sock_ops,
-	.h.hashinfo		= &tcp_hashinfo,
+	.h.hashinfo		= NULL,
 	.no_autobind		= true,
 	.diag_destroy		= tcp_abort,
 };
 EXPORT_SYMBOL_GPL(tcpv6_prot);
 
-/* thinking of making this const? Don't.
- * early_demux can change based on sysctl.
- */
-static struct inet6_protocol tcpv6_protocol = {
-	.early_demux	=	tcp_v6_early_demux,
-	.early_demux_handler =  tcp_v6_early_demux,
+static const struct inet6_protocol tcpv6_protocol = {
 	.handler	=	tcp_v6_rcv,
 	.err_handler	=	tcp_v6_err,
 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
@@ -2235,7 +2234,7 @@ static void __net_exit tcpv6_net_exit(struct net *net)
 
 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
 {
-	inet_twsk_purge(&tcp_hashinfo, AF_INET6);
+	tcp_twsk_purge(net_exit_list, AF_INET6);
 }
 
 static struct pernet_operations tcpv6_net_ops = {