Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

50 files changed, 4135 insertions, 693 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 2dfb12230f..8e94ed7c56 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -741,10 +741,27 @@ config DEFAULT_TCP_CONG
 	default "bbr" if DEFAULT_BBR
 	default "cubic"
 
+config TCP_SIGPOOL
+	tristate
+
+config TCP_AO
+	bool "TCP: Authentication Option (RFC5925)"
+	select CRYPTO
+	select TCP_SIGPOOL
+	depends on 64BIT && IPV6 != m # seq-number extension needs WRITE_ONCE(u64)
+	help
+	  TCP-AO specifies the use of stronger Message Authentication Codes (MACs),
+	  protects against replays for long-lived TCP connections, and
+	  provides more details on the association of security with TCP
+	  connections than TCP MD5 (See RFC5925)
+
+	  If unsure, say N.
+
 config TCP_MD5SIG
 	bool "TCP: MD5 Signature Option support (RFC2385)"
 	select CRYPTO
 	select CRYPTO_MD5
+	select TCP_SIGPOOL
 	help
 	  RFC2385 specifies a method of giving MD5 protection to TCP sessions.
 	  Its main (only?) use is to protect BGP sessions between core routers
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index b18ba8ef93..e144a02a6a 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -62,12 +62,14 @@ obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
 obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
 obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
 obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
+obj-$(CONFIG_TCP_SIGPOOL) += tcp_sigpool.o
 obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o
 obj-$(CONFIG_BPF_SYSCALL) += udp_bpf.o
 obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
 
 obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
 		      xfrm4_output.o xfrm4_protocol.o
+obj-$(CONFIG_TCP_AO) += tcp_ao.o
 
 ifeq ($(CONFIG_BPF_JIT),y)
 obj-$(CONFIG_BPF_SYSCALL) += bpf_tcp_ca.o
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 1c58bd72e1..e59962f34c 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1628,10 +1628,12 @@ EXPORT_SYMBOL(inet_current_timestamp);
 
 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 {
-	if (sk->sk_family == AF_INET)
+	unsigned int family = READ_ONCE(sk->sk_family);
+
+	if (family == AF_INET)
 		return ip_recv_error(sk, msg, len, addr_len);
 #if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family == AF_INET6)
+	if (family == AF_INET6)
 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
 #endif
 	return -EINVAL;
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 015c0f4ec5..a2e6e1fdf8 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #define pr_fmt(fmt) "IPsec: " fmt
 
-#include <crypto/algapi.h>
 #include <crypto/hash.h>
+#include <crypto/utils.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -27,9 +27,7 @@ static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
 {
 	unsigned int len;
 
-	len = size + crypto_ahash_digestsize(ahash) +
-	      (crypto_ahash_alignmask(ahash) &
-	       ~(crypto_tfm_ctx_alignment() - 1));
+	len = size + crypto_ahash_digestsize(ahash);
 
 	len = ALIGN(len, crypto_tfm_ctx_alignment());
 
@@ -46,10 +44,9 @@ static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
 	return tmp + offset;
 }
 
-static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
-			     unsigned int offset)
+static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset)
 {
-	return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
+	return tmp + offset;
 }
 
 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
@@ -129,7 +126,7 @@ static void ah_output_done(void *data, int err)
 	int ihl = ip_hdrlen(skb);
 
 	iph = AH_SKB_CB(skb)->tmp;
-	icv = ah_tmp_icv(ahp->ahash, iph, ihl);
+	icv = ah_tmp_icv(iph, ihl);
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 
 	top_iph->tos = iph->tos;
@@ -182,7 +179,7 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
 	if (!iph)
 		goto out;
 	seqhi = (__be32 *)((char *)iph + ihl);
-	icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
@@ -279,7 +276,7 @@ static void ah_input_done(void *data, int err)
 
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, ihl);
-	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
+	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
 	if (err)
@@ -374,7 +371,7 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	seqhi = (__be32 *)((char *)work_iph + ihl);
 	auth_data = ah_tmp_auth(seqhi, seqhi_len);
-	icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
+	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 9456f5bb35..0d0d725b46 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1125,7 +1125,8 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev)
 	if (neigh) {
 		if (!(READ_ONCE(neigh->nud_state) & NUD_NOARP)) {
 			read_lock_bh(&neigh->lock);
-			memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
+			memcpy(r->arp_ha.sa_data, neigh->ha,
+			       min(dev->addr_len, sizeof(r->arp_ha.sa_data_min)));
 			r->arp_flags = arp_state_to_flags(neigh);
 			read_unlock_bh(&neigh->lock);
 			r->arp_ha.sa_family = dev->type;
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index cb5dbee9e0..2cc50cbfc2 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -39,11 +39,11 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
 	saddr = inet->inet_saddr;
 	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
 		if (!oif || netif_index_is_l3_master(sock_net(sk), oif))
-			oif = inet->mc_index;
+			oif = READ_ONCE(inet->mc_index);
 		if (!saddr)
-			saddr = inet->mc_addr;
+			saddr = READ_ONCE(inet->mc_addr);
 	} else if (!oif) {
-		oif = inet->uc_index;
+		oif = READ_ONCE(inet->uc_index);
 	}
 	fl4 = &inet->cork.fl.u.ip4;
 	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif,
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index ca0ff15dc8..bc74f131fe 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1825,6 +1825,21 @@ done:
 	return err;
 }
 
+/* Combine dev_addr_genid and dev_base_seq to detect changes.
+ */
+static u32 inet_base_seq(const struct net *net)
+{
+	u32 res = atomic_read(&net->ipv4.dev_addr_genid) +
+		  net->dev_base_seq;
+
+	/* Must not return 0 (see nl_dump_check_consistent()).
+	 * Chose a value far away from 0.
+	 */
+	if (!res)
+		res = 0x80000000;
+	return res;
+}
+
 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	const struct nlmsghdr *nlh = cb->nlh;
@@ -1876,8 +1891,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 		idx = 0;
 		head = &tgt_net->dev_index_head[h];
 		rcu_read_lock();
-		cb->seq = atomic_read(&tgt_net->ipv4.dev_addr_genid) ^
-			  tgt_net->dev_base_seq;
+		cb->seq = inet_base_seq(tgt_net);
 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
 			if (idx < s_idx)
 				goto cont;
@@ -2278,8 +2292,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb,
 		idx = 0;
 		head = &net->dev_index_head[h];
 		rcu_read_lock();
-		cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^
-			  net->dev_base_seq;
+		cb->seq = inet_base_seq(net);
 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
 			if (idx < s_idx)
 				goto cont;
diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index 10e96ed6c9..b3271957ad 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -33,6 +33,7 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 	int offset = skb_gro_offset(skb);
 	struct xfrm_offload *xo;
 	struct xfrm_state *x;
+	int encap_type = 0;
 	__be32 seq;
 	__be32 spi;
 
@@ -70,6 +71,9 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 
 	xo->flags |= XFRM_GRO;
 
+	if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
+		encap_type = UDP_ENCAP_ESPINUDP;
+
 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
@@ -77,7 +81,7 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 
 	/* We don't need to handle errors from xfrm_input, it does all
 	 * the error handling and frees the resources on error. */
-	xfrm_input(skb, IPPROTO_ESP, spi, -2);
+	xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
 
 	return ERR_PTR(-EINPROGRESS);
 out_reset:
diff --git a/net/ipv4/fou_bpf.c b/net/ipv4/fou_bpf.c
index 3760a14b6b..4da03bf45c 100644
--- a/net/ipv4/fou_bpf.c
+++ b/net/ipv4/fou_bpf.c
@@ -22,9 +22,7 @@ enum bpf_fou_encap_type {
 	FOU_BPF_ENCAP_GUE,
 };
 
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
-		  "Global functions as their definitions will be in BTF");
+__bpf_kfunc_start_defs();
 
 /* bpf_skb_set_fou_encap - Set FOU encap parameters
  *
@@ -100,7 +98,7 @@ __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
 	return 0;
 }
 
-__diag_pop()
+__bpf_kfunc_end_defs();
 
 BTF_SET8_START(fou_kfunc_set)
 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index b8607763d1..e63a3bf996 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -517,7 +517,7 @@ static struct rtable *icmp_route_lookup(struct net *net,
 	} else
 		return rt;
 
-	err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
+	err = xfrm_decode_session_reverse(net, skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
 	if (err)
 		goto relookup_failed;
 
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index d515881d02..efeeca2b13 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2946,8 +2946,6 @@ static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_l
 				continue;
 			state->im = rcu_dereference(state->idev->mc_list);
 		}
-		if (!state->im)
-			break;
 		spin_lock_bh(&state->im->lock);
 		psf = state->im->sources;
 	}
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index e13a844334..7d0e7aaa71 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -134,7 +134,7 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
 	 * hence this needs to be included regardless of socket family.
 	 */
 	if (ext & (1 << (INET_DIAG_TOS - 1)))
-		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
+		if (nla_put_u8(skb, INET_DIAG_TOS, READ_ONCE(inet->tos)) < 0)
 			goto errout;
 
 #if IS_ENABLED(CONFIG_IPV6)
@@ -165,7 +165,7 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
 		 * For cgroup2 classid is always zero.
 		 */
 		if (!classid)
-			classid = sk->sk_priority;
+			classid = READ_ONCE(sk->sk_priority);
 
 		if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid))
 			goto errout;
@@ -1481,5 +1481,6 @@ static void __exit inet_diag_exit(void)
 module_init(inet_diag_init);
 module_exit(inet_diag_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("INET/INET6: socket monitoring via SOCK_DIAG");
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2 /* AF_INET */);
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10 /* AF_INET6 */);
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index a532f749e4..9456bf9e27 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -1131,10 +1131,33 @@ ok:
 	return 0;
 
 error:
+	if (sk_hashed(sk)) {
+		spinlock_t *lock = inet_ehash_lockp(hinfo, sk->sk_hash);
+
+		sock_prot_inuse_add(net, sk->sk_prot, -1);
+
+		spin_lock(lock);
+		sk_nulls_del_node_init_rcu(sk);
+		spin_unlock(lock);
+
+		sk->sk_hash = 0;
+		inet_sk(sk)->inet_sport = 0;
+		inet_sk(sk)->inet_num = 0;
+
+		if (tw)
+			inet_twsk_bind_unhash(tw, hinfo);
+	}
+
 	spin_unlock(&head2->lock);
 	if (tb_created)
 		inet_bind_bucket_destroy(hinfo->bind_bucket_cachep, tb);
-	spin_unlock_bh(&head->lock);
+	spin_unlock(&head->lock);
+
+	if (tw)
+		inet_twsk_deschedule_put(tw);
+
+	local_bh_enable();
+
 	return -ENOMEM;
 }
 
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 66fac1216d..8b65f12583 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -66,8 +66,6 @@ static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *s
 {
 	struct ip_options *opt	= &(IPCB(skb)->opt);
 
-	__IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
-
 #ifdef CONFIG_NET_SWITCHDEV
 	if (skb->offload_l3_fwd_mark) {
 		consume_skb(skb);
@@ -130,6 +128,8 @@ int ip_forward(struct sk_buff *skb)
 	if (opt->is_strictroute && rt->rt_uses_gateway)
 		goto sr_failed;
 
+	__IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
+
 	IPCB(skb)->flags |= IPSKB_FORWARDED;
 	mtu = ip_dst_mtu_maybe_forward(&rt->dst, true);
 	if (ip_exceeds_mtu(skb, mtu)) {
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 4ab877cf6d..41537d18ee 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -101,6 +101,8 @@ int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct iphdr *iph = ip_hdr(skb);
 
+	IP_INC_STATS(net, IPSTATS_MIB_OUTREQUESTS);
+
 	iph_set_totlen(iph, skb->len);
 	ip_send_check(iph);
 
@@ -544,7 +546,7 @@ EXPORT_SYMBOL(__ip_queue_xmit);
 
 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
 {
-	return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
+	return __ip_queue_xmit(sk, skb, fl, READ_ONCE(inet_sk(sk)->tos));
 }
 EXPORT_SYMBOL(ip_queue_xmit);
 
@@ -1285,6 +1287,12 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 	if (unlikely(!rt))
 		return -EFAULT;
 
+	cork->fragsize = ip_sk_use_pmtu(sk) ?
+			 dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);
+
+	if (!inetdev_valid_mtu(cork->fragsize))
+		return -ENETUNREACH;
+
 	/*
 	 * setup for corking.
 	 */
@@ -1301,12 +1309,6 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 		cork->addr = ipc->addr;
 	}
 
-	cork->fragsize = ip_sk_use_pmtu(sk) ?
-			 dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);
-
-	if (!inetdev_valid_mtu(cork->fragsize))
-		return -ENETUNREACH;
-
 	cork->gso_size = ipc->gso_size;
 
 	cork->dst = &rt->dst;
@@ -1387,8 +1389,8 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 	struct ip_options *opt = NULL;
 	struct rtable *rt = (struct rtable *)cork->dst;
 	struct iphdr *iph;
+	u8 pmtudisc, ttl;
 	__be16 df = 0;
-	__u8 ttl;
 
 	skb = __skb_dequeue(queue);
 	if (!skb)
@@ -1418,8 +1420,9 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 	/* DF bit is set when we want to see DF on outgoing frames.
 	 * If ignore_df is set too, we still allow to fragment this frame
 	 * locally. */
-	if (inet->pmtudisc == IP_PMTUDISC_DO ||
-	    inet->pmtudisc == IP_PMTUDISC_PROBE ||
+	pmtudisc = READ_ONCE(inet->pmtudisc);
+	if (pmtudisc == IP_PMTUDISC_DO ||
+	    pmtudisc == IP_PMTUDISC_PROBE ||
 	    (skb->len <= dst_mtu(&rt->dst) &&
 	     ip_dont_fragment(sk, &rt->dst)))
 		df = htons(IP_DF);
@@ -1430,14 +1433,14 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 	if (cork->ttl != 0)
 		ttl = cork->ttl;
 	else if (rt->rt_type == RTN_MULTICAST)
-		ttl = inet->mc_ttl;
+		ttl = READ_ONCE(inet->mc_ttl);
 	else
 		ttl = ip_select_ttl(inet, &rt->dst);
 
 	iph = ip_hdr(skb);
 	iph->version = 4;
 	iph->ihl = 5;
-	iph->tos = (cork->tos != -1) ? cork->tos : inet->tos;
+	iph->tos = (cork->tos != -1) ? cork->tos : READ_ONCE(inet->tos);
 	iph->frag_off = df;
 	iph->ttl = ttl;
 	iph->protocol = sk->sk_protocol;
@@ -1449,7 +1452,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 		ip_options_build(skb, opt, cork->addr, rt);
 	}
 
-	skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority;
+	skb->priority = (cork->tos != -1) ? cork->priority: READ_ONCE(sk->sk_priority);
 	skb->mark = cork->mark;
 	skb->tstamp = cork->transmit_time;
 	/*
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index cce9cb25f3..8a88e705d8 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -587,12 +587,14 @@ out:
 
 void __ip_sock_set_tos(struct sock *sk, int val)
 {
+	u8 old_tos = inet_sk(sk)->tos;
+
 	if (sk->sk_type == SOCK_STREAM) {
 		val &= ~INET_ECN_MASK;
-		val |= inet_sk(sk)->tos & INET_ECN_MASK;
+		val |= old_tos & INET_ECN_MASK;
 	}
-	if (inet_sk(sk)->tos != val) {
-		inet_sk(sk)->tos = val;
+	if (old_tos != val) {
+		WRITE_ONCE(inet_sk(sk)->tos, val);
 		WRITE_ONCE(sk->sk_priority, rt_tos2priority(val));
 		sk_dst_reset(sk);
 	}
@@ -600,9 +602,9 @@ void __ip_sock_set_tos(struct sock *sk, int val)
 
 void ip_sock_set_tos(struct sock *sk, int val)
 {
-	lock_sock(sk);
+	sockopt_lock_sock(sk);
 	__ip_sock_set_tos(sk, val);
-	release_sock(sk);
+	sockopt_release_sock(sk);
 }
 EXPORT_SYMBOL(ip_sock_set_tos);
 
@@ -622,9 +624,7 @@ int ip_sock_set_mtu_discover(struct sock *sk, int val)
 {
 	if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
 		return -EINVAL;
-	lock_sock(sk);
-	inet_sk(sk)->pmtudisc = val;
-	release_sock(sk);
+	WRITE_ONCE(inet_sk(sk)->pmtudisc, val);
 	return 0;
 }
 EXPORT_SYMBOL(ip_sock_set_mtu_discover);
@@ -1039,6 +1039,22 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 
 		WRITE_ONCE(inet->min_ttl, val);
 		return 0;
+	case IP_MULTICAST_TTL:
+		if (sk->sk_type == SOCK_STREAM)
+			return -EINVAL;
+		if (optlen < 1)
+			return -EINVAL;
+		if (val == -1)
+			val = 1;
+		if (val < 0 || val > 255)
+			return -EINVAL;
+		WRITE_ONCE(inet->mc_ttl, val);
+		return 0;
+	case IP_MTU_DISCOVER:
+		return ip_sock_set_mtu_discover(sk, val);
+	case IP_TOS:	/* This sets both TOS and Precedence */
+		ip_sock_set_tos(sk, val);
+		return 0;
 	}
 
 	err = 0;
@@ -1093,25 +1109,6 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 			}
 		}
 		break;
-	case IP_TOS:	/* This sets both TOS and Precedence */
-		__ip_sock_set_tos(sk, val);
-		break;
-	case IP_MTU_DISCOVER:
-		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
-			goto e_inval;
-		inet->pmtudisc = val;
-		break;
-	case IP_MULTICAST_TTL:
-		if (sk->sk_type == SOCK_STREAM)
-			goto e_inval;
-		if (optlen < 1)
-			goto e_inval;
-		if (val == -1)
-			val = 1;
-		if (val < 0 || val > 255)
-			goto e_inval;
-		inet->mc_ttl = val;
-		break;
 	case IP_UNICAST_IF:
 	{
 		struct net_device *dev = NULL;
@@ -1123,7 +1120,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 
 		ifindex = (__force int)ntohl((__force __be32)val);
 		if (ifindex == 0) {
-			inet->uc_index = 0;
+			WRITE_ONCE(inet->uc_index, 0);
 			err = 0;
 			break;
 		}
@@ -1140,7 +1137,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 		if (sk->sk_bound_dev_if && midx != sk->sk_bound_dev_if)
 			break;
 
-		inet->uc_index = ifindex;
+		WRITE_ONCE(inet->uc_index, ifindex);
 		err = 0;
 		break;
 	}
@@ -1178,8 +1175,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 
 		if (!mreq.imr_ifindex) {
 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
-				inet->mc_index = 0;
-				inet->mc_addr  = 0;
+				WRITE_ONCE(inet->mc_index, 0);
+				WRITE_ONCE(inet->mc_addr, 0);
 				err = 0;
 				break;
 			}
@@ -1204,8 +1201,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
 		    midx != sk->sk_bound_dev_if)
 			break;
 
-		inet->mc_index = mreq.imr_ifindex;
-		inet->mc_addr  = mreq.imr_address.s_addr;
+		WRITE_ONCE(inet->mc_index, mreq.imr_ifindex);
+		WRITE_ONCE(inet->mc_addr, mreq.imr_address.s_addr);
 		err = 0;
 		break;
 	}
@@ -1369,12 +1366,13 @@ e_inval:
  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
  * @sk: socket
  * @skb: buffer
+ * @drop_dst: if true, drops skb dst
  *
  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
  * destination in skb->cb[] before dst drop.
  * This way, receiver doesn't make cache line misses to read rtable.
  */
-void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
+void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst)
 {
 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
 	bool prepare = inet_test_bit(PKTINFO, sk) ||
@@ -1403,7 +1401,8 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
 		pktinfo->ipi_ifindex = 0;
 		pktinfo->ipi_spec_dst.s_addr = 0;
 	}
-	skb_dst_drop(skb);
+	if (drop_dst)
+		skb_dst_drop(skb);
 }
 
 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
@@ -1592,27 +1591,29 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	case IP_MINTTL:
 		val = READ_ONCE(inet->min_ttl);
 		goto copyval;
-	}
-
-	if (needs_rtnl)
-		rtnl_lock();
-	sockopt_lock_sock(sk);
-
-	switch (optname) {
+	case IP_MULTICAST_TTL:
+		val = READ_ONCE(inet->mc_ttl);
+		goto copyval;
+	case IP_MTU_DISCOVER:
+		val = READ_ONCE(inet->pmtudisc);
+		goto copyval;
+	case IP_TOS:
+		val = READ_ONCE(inet->tos);
+		goto copyval;
 	case IP_OPTIONS:
 	{
 		unsigned char optbuf[sizeof(struct ip_options)+40];
 		struct ip_options *opt = (struct ip_options *)optbuf;
 		struct ip_options_rcu *inet_opt;
 
-		inet_opt = rcu_dereference_protected(inet->inet_opt,
-						     lockdep_sock_is_held(sk));
+		rcu_read_lock();
+		inet_opt = rcu_dereference(inet->inet_opt);
 		opt->optlen = 0;
 		if (inet_opt)
 			memcpy(optbuf, &inet_opt->opt,
 			       sizeof(struct ip_options) +
 			       inet_opt->opt.optlen);
-		sockopt_release_sock(sk);
+		rcu_read_unlock();
 
 		if (opt->optlen == 0) {
 			len = 0;
@@ -1628,12 +1629,6 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			return -EFAULT;
 		return 0;
 	}
-	case IP_TOS:
-		val = inet->tos;
-		break;
-	case IP_MTU_DISCOVER:
-		val = inet->pmtudisc;
-		break;
 	case IP_MTU:
 	{
 		struct dst_entry *dst;
@@ -1643,24 +1638,55 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			val = dst_mtu(dst);
 			dst_release(dst);
 		}
-		if (!val) {
-			sockopt_release_sock(sk);
+		if (!val)
 			return -ENOTCONN;
+		goto copyval;
+	}
+	case IP_PKTOPTIONS:
+	{
+		struct msghdr msg;
+
+		if (sk->sk_type != SOCK_STREAM)
+			return -ENOPROTOOPT;
+
+		if (optval.is_kernel) {
+			msg.msg_control_is_user = false;
+			msg.msg_control = optval.kernel;
+		} else {
+			msg.msg_control_is_user = true;
+			msg.msg_control_user = optval.user;
 		}
-		break;
+		msg.msg_controllen = len;
+		msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
+
+		if (inet_test_bit(PKTINFO, sk)) {
+			struct in_pktinfo info;
+
+			info.ipi_addr.s_addr = READ_ONCE(inet->inet_rcv_saddr);
+			info.ipi_spec_dst.s_addr = READ_ONCE(inet->inet_rcv_saddr);
+			info.ipi_ifindex = READ_ONCE(inet->mc_index);
+			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
+		}
+		if (inet_test_bit(TTL, sk)) {
+			int hlim = READ_ONCE(inet->mc_ttl);
+
+			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
+		}
+		if (inet_test_bit(TOS, sk)) {
+			int tos = READ_ONCE(inet->rcv_tos);
+			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
+		}
+		len -= msg.msg_controllen;
+		return copy_to_sockptr(optlen, &len, sizeof(int));
 	}
-	case IP_MULTICAST_TTL:
-		val = inet->mc_ttl;
-		break;
 	case IP_UNICAST_IF:
-		val = (__force int)htonl((__u32) inet->uc_index);
-		break;
+		val = (__force int)htonl((__u32) READ_ONCE(inet->uc_index));
+		goto copyval;
 	case IP_MULTICAST_IF:
 	{
 		struct in_addr addr;
 		len = min_t(unsigned int, len, sizeof(struct in_addr));
-		addr.s_addr = inet->mc_addr;
-		sockopt_release_sock(sk);
+		addr.s_addr = READ_ONCE(inet->mc_addr);
 
 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
 			return -EFAULT;
@@ -1668,6 +1694,13 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			return -EFAULT;
 		return 0;
 	}
+	}
+
+	if (needs_rtnl)
+		rtnl_lock();
+	sockopt_lock_sock(sk);
+
+	switch (optname) {
 	case IP_MSFILTER:
 	{
 		struct ip_msfilter msf;
@@ -1690,44 +1723,6 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
 		else
 			err = ip_get_mcast_msfilter(sk, optval, optlen, len);
 		goto out;
-	case IP_PKTOPTIONS:
-	{
-		struct msghdr msg;
-
-		sockopt_release_sock(sk);
-
-		if (sk->sk_type != SOCK_STREAM)
-			return -ENOPROTOOPT;
-
-		if (optval.is_kernel) {
-			msg.msg_control_is_user = false;
-			msg.msg_control = optval.kernel;
-		} else {
-			msg.msg_control_is_user = true;
-			msg.msg_control_user = optval.user;
-		}
-		msg.msg_controllen = len;
-		msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
-
-		if (inet_test_bit(PKTINFO, sk)) {
-			struct in_pktinfo info;
-
-			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
-			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
-			info.ipi_ifindex = inet->mc_index;
-			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
-		}
-		if (inet_test_bit(TTL, sk)) {
-			int hlim = inet->mc_ttl;
-			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
-		}
-		if (inet_test_bit(TOS, sk)) {
-			int tos = inet->rcv_tos;
-			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
-		}
-		len -= msg.msg_controllen;
-		return copy_to_sockptr(optlen, &len, sizeof(int));
-	}
 	case IP_LOCAL_PORT_RANGE:
 		val = inet->local_port_range.hi << 16 | inet->local_port_range.lo;
 		break;
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 586b1b3e35..80ccd6661a 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -332,7 +332,7 @@ static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
 	};
 	skb_reset_network_header(skb);
 
-	csum = csum_partial(icmp6h, len, 0);
+	csum = skb_checksum(skb, skb_transport_offset(skb), len, 0);
 	icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
 					      IPPROTO_ICMPV6, csum);
 
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index d1e7d0ceb7..9ab9b3ebe0 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -288,11 +288,11 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
-		xfrm_decode_session(skb, &fl, AF_INET);
+		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET);
 		break;
 	case htons(ETH_P_IPV6):
 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-		xfrm_decode_session(skb, &fl, AF_INET6);
+		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6);
 		break;
 	default:
 		goto tx_err;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 0063a23725..e49242706b 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1073,7 +1073,7 @@ static int ipmr_cache_report(const struct mr_table *mrt,
 		msg = (struct igmpmsg *)skb_network_header(skb);
 		msg->im_vif = vifi;
 		msg->im_vif_hi = vifi >> 8;
-		ipv4_pktinfo_prepare(mroute_sk, pkt);
+		ipv4_pktinfo_prepare(mroute_sk, pkt, false);
 		memcpy(skb->cb, pkt->cb, sizeof(skb->cb));
 		/* Add our header */
 		igmp = skb_put(skb, sizeof(struct igmphdr));
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index bd13516548..591a273780 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -62,7 +62,7 @@ int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, un
 
 #ifdef CONFIG_XFRM
 	if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
-	    xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
+	    xfrm_decode_session(net, skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
 		struct dst_entry *dst = skb_dst(skb);
 		skb_dst_set(skb, NULL);
 		dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0);
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 3abb430af9..385d945d8e 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -36,12 +36,12 @@ static const struct xt_table packet_mangler = {
 static unsigned int
 ipt_mangle_out(void *priv, struct sk_buff *skb, const struct nf_hook_state *state)
 {
-	unsigned int ret;
+	unsigned int ret, verdict;
 	const struct iphdr *iph;
-	u_int8_t tos;
 	__be32 saddr, daddr;
-	u_int32_t mark;
+	u32 mark;
 	int err;
+	u8 tos;
 
 	/* Save things which could affect route */
 	mark = skb->mark;
@@ -51,8 +51,9 @@ ipt_mangle_out(void *priv, struct sk_buff *skb, const struct nf_hook_state *stat
 	tos = iph->tos;
 
 	ret = ipt_do_table(priv, skb, state);
+	verdict = ret & NF_VERDICT_MASK;
 	/* Reroute for ANY change. */
-	if (ret != NF_DROP && ret != NF_STOLEN) {
+	if (verdict != NF_DROP && verdict != NF_STOLEN) {
 		iph = ip_hdr(skb);
 
 		if (iph->saddr != saddr ||
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index 56f6ecc434..4d42d0756f 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -170,3 +170,4 @@ module_init(iptable_nat_init);
 module_exit(iptable_nat_exit);
 
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("iptables legacy nat table");
diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
index ca5e5b2158..0e7f53964d 100644
--- a/net/ipv4/netfilter/iptable_raw.c
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -108,3 +108,4 @@ static void __exit iptable_raw_fini(void)
 module_init(iptable_raw_init);
 module_exit(iptable_raw_fini);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("iptables legacy raw table");
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c
index 265b39bc43..482e733c33 100644
--- a/net/ipv4/netfilter/nf_defrag_ipv4.c
+++ b/net/ipv4/netfilter/nf_defrag_ipv4.c
@@ -186,3 +186,4 @@ module_init(nf_defrag_init);
 module_exit(nf_defrag_fini);
 
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IPv4 defragmentation support");
diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.asn1 b/net/ipv4/netfilter/nf_nat_snmp_basic.asn1
index 24b73268f3..dc2cc57941 100644
--- a/net/ipv4/netfilter/nf_nat_snmp_basic.asn1
+++ b/net/ipv4/netfilter/nf_nat_snmp_basic.asn1
@@ -1,3 +1,11 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 1990, 2002 IETF Trust and the persons identified as authors
+-- of the code
+--
+-- https://www.rfc-editor.org/rfc/rfc1157#section-4
+-- https://www.rfc-editor.org/rfc/rfc3416#section-3
+
 Message ::=
 	SEQUENCE {
 		version
diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index fc761915c5..04504b2b51 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -339,3 +339,4 @@ void nf_send_unreach(struct sk_buff *skb_in, int code, int hook)
 EXPORT_SYMBOL_GPL(nf_send_unreach);
 
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IPv4 packet rejection core");
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 4cb0c896ca..823306487a 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -551,7 +551,7 @@ void ping_err(struct sk_buff *skb, int offset, u32 info)
 		case ICMP_DEST_UNREACH:
 			if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
 				ipv4_sk_update_pmtu(skb, sk, info);
-				if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
+				if (READ_ONCE(inet_sock->pmtudisc) != IP_PMTUDISC_DONT) {
 					err = EMSGSIZE;
 					harderr = 1;
 					break;
@@ -581,7 +581,7 @@ void ping_err(struct sk_buff *skb, int offset, u32 info)
 	 *	4.1.3.3.
 	 */
 	if ((family == AF_INET && !inet_test_bit(RECVERR, sk)) ||
-	    (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
+	    (family == AF_INET6 && !inet6_test_bit(RECVERR6, sk))) {
 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 			goto out;
 	} else {
@@ -773,11 +773,11 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 	if (ipv4_is_multicast(daddr)) {
 		if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
-			ipc.oif = inet->mc_index;
+			ipc.oif = READ_ONCE(inet->mc_index);
 		if (!saddr)
-			saddr = inet->mc_addr;
+			saddr = READ_ONCE(inet->mc_addr);
 	} else if (!ipc.oif)
-		ipc.oif = inet->uc_index;
+		ipc.oif = READ_ONCE(inet->uc_index);
 
 	flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, scope,
 			   sk->sk_protocol, inet_sk_flowi_flags(sk), faddr,
@@ -899,7 +899,6 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
 
 #if IS_ENABLED(CONFIG_IPV6)
 	} else if (family == AF_INET6) {
-		struct ipv6_pinfo *np = inet6_sk(sk);
 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 
@@ -908,7 +907,7 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
 			sin6->sin6_port = 0;
 			sin6->sin6_addr = ip6->saddr;
 			sin6->sin6_flowinfo = 0;
-			if (np->sndflow)
+			if (inet6_test_bit(SNDFLOW, sk))
 				sin6->sin6_flowinfo = ip6_flowinfo(ip6);
 			sin6->sin6_scope_id =
 				ipv6_iface_scope_id(&sin6->sin6_addr,
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index eaf1d3113b..5f4654ebff 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -83,7 +83,7 @@ static const struct snmp_mib snmp4_ipstats_list[] = {
 	SNMP_MIB_ITEM("InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
 	SNMP_MIB_ITEM("InDiscards", IPSTATS_MIB_INDISCARDS),
 	SNMP_MIB_ITEM("InDelivers", IPSTATS_MIB_INDELIVERS),
-	SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTPKTS),
+	SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTREQUESTS),
 	SNMP_MIB_ITEM("OutDiscards", IPSTATS_MIB_OUTDISCARDS),
 	SNMP_MIB_ITEM("OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
 	SNMP_MIB_ITEM("ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
@@ -93,6 +93,7 @@ static const struct snmp_mib snmp4_ipstats_list[] = {
 	SNMP_MIB_ITEM("FragOKs", IPSTATS_MIB_FRAGOKS),
 	SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS),
 	SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES),
+	SNMP_MIB_ITEM("OutTransmits", IPSTATS_MIB_OUTPKTS),
 	SNMP_MIB_SENTINEL
 };
 
@@ -298,6 +299,11 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
 	SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
 	SNMP_MIB_ITEM("TCPPLBRehash", LINUX_MIB_TCPPLBREHASH),
+	SNMP_MIB_ITEM("TCPAORequired", LINUX_MIB_TCPAOREQUIRED),
+	SNMP_MIB_ITEM("TCPAOBad", LINUX_MIB_TCPAOBAD),
+	SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
+	SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
+	SNMP_MIB_ITEM("TCPAODroppedIcmps", LINUX_MIB_TCPAODROPPEDICMPS),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 4b5db5d1ed..aea89326c6 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -239,7 +239,7 @@ static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
 		if (code > NR_ICMP_UNREACH)
 			break;
 		if (code == ICMP_FRAG_NEEDED) {
-			harderr = inet->pmtudisc != IP_PMTUDISC_DONT;
+			harderr = READ_ONCE(inet->pmtudisc) != IP_PMTUDISC_DONT;
 			err = EMSGSIZE;
 		} else {
 			err = icmp_err_convert[code].errno;
@@ -292,7 +292,7 @@ static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 	/* Charge it to the socket. */
 
-	ipv4_pktinfo_prepare(sk, skb);
+	ipv4_pktinfo_prepare(sk, skb, true);
 	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
 		kfree_skb_reason(skb, reason);
 		return NET_RX_DROP;
@@ -482,7 +482,7 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	int free = 0;
 	__be32 daddr;
 	__be32 saddr;
-	int err;
+	int uc_index, err;
 	struct ip_options_data opt_copy;
 	struct raw_frag_vec rfv;
 	int hdrincl;
@@ -576,24 +576,25 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	tos = get_rttos(&ipc, inet);
 	scope = ip_sendmsg_scope(inet, &ipc, msg);
 
+	uc_index = READ_ONCE(inet->uc_index);
 	if (ipv4_is_multicast(daddr)) {
 		if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
-			ipc.oif = inet->mc_index;
+			ipc.oif = READ_ONCE(inet->mc_index);
 		if (!saddr)
-			saddr = inet->mc_addr;
+			saddr = READ_ONCE(inet->mc_addr);
 	} else if (!ipc.oif) {
-		ipc.oif = inet->uc_index;
-	} else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
+		ipc.oif = uc_index;
+	} else if (ipv4_is_lbcast(daddr) && uc_index) {
 		/* oif is set, packet is to local broadcast
 		 * and uc_index is set. oif is most likely set
 		 * by sk_bound_dev_if. If uc_index != oif check if the
 		 * oif is an L3 master and uc_index is an L3 slave.
 		 * If so, we want to allow the send using the uc_index.
 		 */
-		if (ipc.oif != inet->uc_index &&
+		if (ipc.oif != uc_index &&
 		    ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
-							      inet->uc_index)) {
-			ipc.oif = inet->uc_index;
+							      uc_index)) {
+			ipc.oif = uc_index;
 		}
 	}
 
diff --git a/net/ipv4/raw_diag.c b/net/ipv4/raw_diag.c
index 63a40e4b67..fe2140c837 100644
--- a/net/ipv4/raw_diag.c
+++ b/net/ipv4/raw_diag.c
@@ -257,5 +257,6 @@ static void __exit raw_diag_exit(void)
 module_init(raw_diag_init);
 module_exit(raw_diag_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAW socket monitoring via SOCK_DIAG");
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 3bad9aa066..16615d107c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1632,7 +1632,7 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
 {
 	struct rtable *rt;
 
-	rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
+	rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
 		       (noxfrm ? DST_NOXFRM : 0));
 
 	if (rt) {
@@ -1660,7 +1660,7 @@ struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
 {
 	struct rtable *new_rt;
 
-	new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
+	new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
 			   rt->dst.flags);
 
 	if (new_rt) {
@@ -2834,7 +2834,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
 	struct rtable *ort = (struct rtable *) dst_orig;
 	struct rtable *rt;
 
-	rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
+	rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0);
 	if (rt) {
 		struct dst_entry *new = &rt->dst;
 
@@ -2885,54 +2885,6 @@ struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
 }
 EXPORT_SYMBOL_GPL(ip_route_output_flow);
 
-struct rtable *ip_route_output_tunnel(struct sk_buff *skb,
-				      struct net_device *dev,
-				      struct net *net, __be32 *saddr,
-				      const struct ip_tunnel_info *info,
-				      u8 protocol, bool use_cache)
-{
-#ifdef CONFIG_DST_CACHE
-	struct dst_cache *dst_cache;
-#endif
-	struct rtable *rt = NULL;
-	struct flowi4 fl4;
-	__u8 tos;
-
-#ifdef CONFIG_DST_CACHE
-	dst_cache = (struct dst_cache *)&info->dst_cache;
-	if (use_cache) {
-		rt = dst_cache_get_ip4(dst_cache, saddr);
-		if (rt)
-			return rt;
-	}
-#endif
-	memset(&fl4, 0, sizeof(fl4));
-	fl4.flowi4_mark = skb->mark;
-	fl4.flowi4_proto = protocol;
-	fl4.daddr = info->key.u.ipv4.dst;
-	fl4.saddr = info->key.u.ipv4.src;
-	tos = info->key.tos;
-	fl4.flowi4_tos = RT_TOS(tos);
-
-	rt = ip_route_output_key(net, &fl4);
-	if (IS_ERR(rt)) {
-		netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
-		return ERR_PTR(-ENETUNREACH);
-	}
-	if (rt->dst.dev == dev) { /* is this necessary? */
-		netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
-		ip_rt_put(rt);
-		return ERR_PTR(-ELOOP);
-	}
-#ifdef CONFIG_DST_CACHE
-	if (use_cache)
-		dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
-#endif
-	*saddr = fl4.saddr;
-	return rt;
-}
-EXPORT_SYMBOL_GPL(ip_route_output_tunnel);
-
 /* called with rcu_read_lock held */
 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
 			struct rtable *rt, u32 table_id, struct flowi4 *fl4,
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 3b4dafefb4..d37282c06e 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -51,6 +51,14 @@ static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
 			    count, &syncookie_secret[c]);
 }
 
+/* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */
+static u64 tcp_ns_to_ts(bool usec_ts, u64 val)
+{
+	if (usec_ts)
+		return div_u64(val, NSEC_PER_USEC);
+
+	return div_u64(val, NSEC_PER_MSEC);
+}
 
 /*
  * when syncookies are in effect and tcp timestamps are enabled we encode
@@ -62,7 +70,7 @@ static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
 u64 cookie_init_timestamp(struct request_sock *req, u64 now)
 {
 	const struct inet_request_sock *ireq = inet_rsk(req);
-	u64 ts, ts_now = tcp_ns_to_ts(now);
+	u64 ts, ts_now = tcp_ns_to_ts(false, now);
 	u32 options = 0;
 
 	options = ireq->wscale_ok ? ireq->snd_wscale : TS_OPT_WSCALE_MASK;
@@ -76,7 +84,9 @@ u64 cookie_init_timestamp(struct request_sock *req, u64 now)
 	if (ts > ts_now)
 		ts -= (1UL << TSBITS);
 
-	return ts * (NSEC_PER_SEC / TCP_TS_HZ);
+	if (tcp_rsk(req)->req_usec_ts)
+		return ts * NSEC_PER_USEC;
+	return ts * NSEC_PER_MSEC;
 }
 
 
@@ -296,6 +306,8 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops,
 	treq->af_specific = af_ops;
 
 	treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
+	treq->req_usec_ts = false;
+
 #if IS_ENABLED(CONFIG_MPTCP)
 	treq->is_mptcp = sk_is_mptcp(sk);
 	if (treq->is_mptcp) {
@@ -332,6 +344,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	__u8 rcv_wscale;
 	struct flowi4 fl4;
 	u32 tsoff = 0;
+	int l3index;
 
 	if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
 	    !th->ack || th->rst)
@@ -393,6 +406,9 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 
 	ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
 
+	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+	tcp_ao_syncookie(sk, skb, treq, AF_INET, l3index);
+
 	/* We throwed the options of the initial SYN away, so we hope
 	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
 	 */
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 6ac890b407..f63a545a73 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -1367,6 +1367,15 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 	{
+		.procname	= "tcp_backlog_ack_defer",
+		.data		= &init_net.ipv4.sysctl_tcp_backlog_ack_defer,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler	= proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
 		.procname       = "tcp_reflect_tos",
 		.data           = &init_net.ipv4.sysctl_tcp_reflect_tos,
 		.maxlen         = sizeof(u8),
@@ -1489,6 +1498,14 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
+	{
+		.procname	= "tcp_pingpong_thresh",
+		.data		= &init_net.ipv4.sysctl_tcp_pingpong_thresh,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler	= proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ONE,
+	},
 	{ }
 };
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index fb417aee86..b30ef770a6 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1786,7 +1786,17 @@ static skb_frag_t *skb_advance_to_frag(struct sk_buff *skb, u32 offset_skb,
 
 static bool can_map_frag(const skb_frag_t *frag)
 {
-	return skb_frag_size(frag) == PAGE_SIZE && !skb_frag_off(frag);
+	struct page *page;
+
+	if (skb_frag_size(frag) != PAGE_SIZE || skb_frag_off(frag))
+		return false;
+
+	page = skb_frag_page(frag);
+
+	if (PageCompound(page) || page->mapping)
+		return false;
+
+	return true;
 }
 
 static int find_next_mappable_frag(const skb_frag_t *frag,
@@ -3610,6 +3620,35 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
 		__tcp_sock_set_quickack(sk, val);
 		break;
 
+	case TCP_AO_REPAIR:
+		if (!tcp_can_repair_sock(sk)) {
+			err = -EPERM;
+			break;
+		}
+		err = tcp_ao_set_repair(sk, optval, optlen);
+		break;
+#ifdef CONFIG_TCP_AO
+	case TCP_AO_ADD_KEY:
+	case TCP_AO_DEL_KEY:
+	case TCP_AO_INFO: {
+		/* If this is the first TCP-AO setsockopt() on the socket,
+		 * sk_state has to be LISTEN or CLOSE. Allow TCP_REPAIR
+		 * in any state.
+		 */
+		if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
+			goto ao_parse;
+		if (rcu_dereference_protected(tcp_sk(sk)->ao_info,
+					      lockdep_sock_is_held(sk)))
+			goto ao_parse;
+		if (tp->repair)
+			goto ao_parse;
+		err = -EISCONN;
+		break;
+ao_parse:
+		err = tp->af_specific->ao_parse(sk, optname, optval, optlen);
+		break;
+	}
+#endif
 #ifdef CONFIG_TCP_MD5SIG
 	case TCP_MD5SIG:
 	case TCP_MD5SIG_EXT:
@@ -3648,10 +3687,16 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
 			tp->fastopen_no_cookie = val;
 		break;
 	case TCP_TIMESTAMP:
-		if (!tp->repair)
+		if (!tp->repair) {
 			err = -EPERM;
-		else
-			WRITE_ONCE(tp->tsoffset, val - tcp_time_stamp_raw());
+			break;
+		}
+		/* val is an opaque field,
+		 * and low order bit contains usec_ts enable bit.
+		 * Its a best effort, and we do not care if user makes an error.
+		 */
+		tp->tcp_usec_ts = val & 1;
+		WRITE_ONCE(tp->tsoffset, val - tcp_clock_ts(tp->tcp_usec_ts));
 		break;
 	case TCP_REPAIR_WINDOW:
 		err = tcp_repair_set_window(tp, optval, optlen);
@@ -3773,10 +3818,12 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
 	if (tp->syn_data_acked)
 		info->tcpi_options |= TCPI_OPT_SYN_DATA;
+	if (tp->tcp_usec_ts)
+		info->tcpi_options |= TCPI_OPT_USEC_TS;
 
 	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
-	info->tcpi_ato = jiffies_to_usecs(min(icsk->icsk_ack.ato,
-					      tcp_delack_max(sk)));
+	info->tcpi_ato = jiffies_to_usecs(min_t(u32, icsk->icsk_ack.ato,
+						tcp_delack_max(sk)));
 	info->tcpi_snd_mss = tp->mss_cache;
 	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
 
@@ -3832,6 +3879,13 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 	info->tcpi_rcv_wnd = tp->rcv_wnd;
 	info->tcpi_rehash = tp->plb_rehash + tp->timeout_rehash;
 	info->tcpi_fastopen_client_fail = tp->fastopen_client_fail;
+
+	info->tcpi_total_rto = tp->total_rto;
+	info->tcpi_total_rto_recoveries = tp->total_rto_recoveries;
+	info->tcpi_total_rto_time = tp->total_rto_time;
+	if (tp->rto_stamp)
+		info->tcpi_total_rto_time += tcp_clock_ms() - tp->rto_stamp;
+
 	unlock_sock_fast(sk, slow);
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);
@@ -4155,7 +4209,11 @@ int do_tcp_getsockopt(struct sock *sk, int level,
 		break;
 
 	case TCP_TIMESTAMP:
-		val = tcp_time_stamp_raw() + READ_ONCE(tp->tsoffset);
+		val = tcp_clock_ts(tp->tcp_usec_ts) + READ_ONCE(tp->tsoffset);
+		if (tp->tcp_usec_ts)
+			val |= 1;
+		else
+			val &= ~1;
 		break;
 	case TCP_NOTSENT_LOWAT:
 		val = READ_ONCE(tp->notsent_lowat);
@@ -4265,6 +4323,23 @@ zerocopy_rcv_out:
 		return err;
 	}
 #endif
+	case TCP_AO_REPAIR:
+		if (!tcp_can_repair_sock(sk))
+			return -EPERM;
+		return tcp_ao_get_repair(sk, optval, optlen);
+	case TCP_AO_GET_KEYS:
+	case TCP_AO_INFO: {
+		int err;
+
+		sockopt_lock_sock(sk);
+		if (optname == TCP_AO_GET_KEYS)
+			err = tcp_ao_get_mkts(sk, optval, optlen);
+		else
+			err = tcp_ao_get_sock_info(sk, optval, optlen);
+		sockopt_release_sock(sk);
+
+		return err;
+	}
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -4303,141 +4378,52 @@ int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
 EXPORT_SYMBOL(tcp_getsockopt);
 
 #ifdef CONFIG_TCP_MD5SIG
-static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
-static DEFINE_MUTEX(tcp_md5sig_mutex);
-static bool tcp_md5sig_pool_populated = false;
-
-static void __tcp_alloc_md5sig_pool(void)
-{
-	struct crypto_ahash *hash;
-	int cpu;
-
-	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(hash))
-		return;
-
-	for_each_possible_cpu(cpu) {
-		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
-		struct ahash_request *req;
-
-		if (!scratch) {
-			scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
-					       sizeof(struct tcphdr),
-					       GFP_KERNEL,
-					       cpu_to_node(cpu));
-			if (!scratch)
-				return;
-			per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
-		}
-		if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
-			continue;
-
-		req = ahash_request_alloc(hash, GFP_KERNEL);
-		if (!req)
-			return;
-
-		ahash_request_set_callback(req, 0, NULL, NULL);
-
-		per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
-	}
-	/* before setting tcp_md5sig_pool_populated, we must commit all writes
-	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
-	 */
-	smp_wmb();
-	/* Paired with READ_ONCE() from tcp_alloc_md5sig_pool()
-	 * and tcp_get_md5sig_pool().
-	*/
-	WRITE_ONCE(tcp_md5sig_pool_populated, true);
-}
+int tcp_md5_sigpool_id = -1;
+EXPORT_SYMBOL_GPL(tcp_md5_sigpool_id);
 
-bool tcp_alloc_md5sig_pool(void)
+int tcp_md5_alloc_sigpool(void)
 {
-	/* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
-	if (unlikely(!READ_ONCE(tcp_md5sig_pool_populated))) {
-		mutex_lock(&tcp_md5sig_mutex);
-
-		if (!tcp_md5sig_pool_populated)
-			__tcp_alloc_md5sig_pool();
+	size_t scratch_size;
+	int ret;
 
-		mutex_unlock(&tcp_md5sig_mutex);
+	scratch_size = sizeof(union tcp_md5sum_block) + sizeof(struct tcphdr);
+	ret = tcp_sigpool_alloc_ahash("md5", scratch_size);
+	if (ret >= 0) {
+		/* As long as any md5 sigpool was allocated, the return
+		 * id would stay the same. Re-write the id only for the case
+		 * when previously all MD5 keys were deleted and this call
+		 * allocates the first MD5 key, which may return a different
+		 * sigpool id than was used previously.
+		 */
+		WRITE_ONCE(tcp_md5_sigpool_id, ret); /* Avoids the compiler potentially being smart here */
+		return 0;
 	}
-	/* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
-	return READ_ONCE(tcp_md5sig_pool_populated);
+	return ret;
 }
-EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
 
-
-/**
- *	tcp_get_md5sig_pool - get md5sig_pool for this user
- *
- *	We use percpu structure, so if we succeed, we exit with preemption
- *	and BH disabled, to make sure another thread or softirq handling
- *	wont try to get same context.
- */
-struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
+void tcp_md5_release_sigpool(void)
 {
-	local_bh_disable();
-
-	/* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
-	if (READ_ONCE(tcp_md5sig_pool_populated)) {
-		/* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
-		smp_rmb();
-		return this_cpu_ptr(&tcp_md5sig_pool);
-	}
-	local_bh_enable();
-	return NULL;
+	tcp_sigpool_release(READ_ONCE(tcp_md5_sigpool_id));
 }
-EXPORT_SYMBOL(tcp_get_md5sig_pool);
 
-int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
-			  const struct sk_buff *skb, unsigned int header_len)
+void tcp_md5_add_sigpool(void)
 {
-	struct scatterlist sg;
-	const struct tcphdr *tp = tcp_hdr(skb);
-	struct ahash_request *req = hp->md5_req;
-	unsigned int i;
-	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
-					   skb_headlen(skb) - header_len : 0;
-	const struct skb_shared_info *shi = skb_shinfo(skb);
-	struct sk_buff *frag_iter;
-
-	sg_init_table(&sg, 1);
-
-	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
-	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
-	if (crypto_ahash_update(req))
-		return 1;
-
-	for (i = 0; i < shi->nr_frags; ++i) {
-		const skb_frag_t *f = &shi->frags[i];
-		unsigned int offset = skb_frag_off(f);
-		struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
-
-		sg_set_page(&sg, page, skb_frag_size(f),
-			    offset_in_page(offset));
-		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
-		if (crypto_ahash_update(req))
-			return 1;
-	}
-
-	skb_walk_frags(skb, frag_iter)
-		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
-			return 1;
-
-	return 0;
+	tcp_sigpool_get(READ_ONCE(tcp_md5_sigpool_id));
 }
-EXPORT_SYMBOL(tcp_md5_hash_skb_data);
 
-int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
+int tcp_md5_hash_key(struct tcp_sigpool *hp,
+		     const struct tcp_md5sig_key *key)
 {
 	u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
 	struct scatterlist sg;
 
 	sg_init_one(&sg, key->key, keylen);
-	ahash_request_set_crypt(hp->md5_req, &sg, NULL, keylen);
+	ahash_request_set_crypt(hp->req, &sg, NULL, keylen);
 
-	/* We use data_race() because tcp_md5_do_add() might change key->key under us */
-	return data_race(crypto_ahash_update(hp->md5_req));
+	/* We use data_race() because tcp_md5_do_add() might change
+	 * key->key under us
+	 */
+	return data_race(crypto_ahash_update(hp->req));
 }
 EXPORT_SYMBOL(tcp_md5_hash_key);
 
@@ -4445,42 +4431,24 @@ EXPORT_SYMBOL(tcp_md5_hash_key);
 enum skb_drop_reason
 tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
 		     const void *saddr, const void *daddr,
-		     int family, int dif, int sdif)
+		     int family, int l3index, const __u8 *hash_location)
 {
-	/*
-	 * This gets called for each TCP segment that arrives
-	 * so we want to be efficient.
+	/* This gets called for each TCP segment that has TCP-MD5 option.
 	 * We have 3 drop cases:
 	 * o No MD5 hash and one expected.
 	 * o MD5 hash and we're not expecting one.
 	 * o MD5 hash and its wrong.
 	 */
-	const __u8 *hash_location = NULL;
-	struct tcp_md5sig_key *hash_expected;
-	const struct tcphdr *th = tcp_hdr(skb);
 	const struct tcp_sock *tp = tcp_sk(sk);
-	int genhash, l3index;
+	struct tcp_md5sig_key *key;
 	u8 newhash[16];
+	int genhash;
 
-	/* 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_md5_do_lookup(sk, l3index, saddr, family);
-	hash_location = tcp_parse_md5sig_option(th);
+	key = tcp_md5_do_lookup(sk, l3index, saddr, family);
 
-	/* We've parsed the options - do we have a hash? */
-	if (!hash_expected && !hash_location)
-		return SKB_NOT_DROPPED_YET;
-
-	if (hash_expected && !hash_location) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
-		return SKB_DROP_REASON_TCP_MD5NOTFOUND;
-	}
-
-	if (!hash_expected && hash_location) {
+	if (!key && hash_location) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+		tcp_hash_fail("Unexpected MD5 Hash found", family, skb, "");
 		return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
 	}
 
@@ -4489,27 +4457,26 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
 	 * IPv4-mapped case.
 	 */
 	if (family == AF_INET)
-		genhash = tcp_v4_md5_hash_skb(newhash,
-					      hash_expected,
-					      NULL, skb);
+		genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
 	else
-		genhash = tp->af_specific->calc_md5_hash(newhash,
-							 hash_expected,
+		genhash = tp->af_specific->calc_md5_hash(newhash, key,
 							 NULL, skb);
-
 	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
 		if (family == AF_INET) {
-			net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
-					saddr, ntohs(th->source),
-					daddr, ntohs(th->dest),
-					genhash ? " tcp_v4_calc_md5_hash failed"
-					: "", l3index);
+			tcp_hash_fail("MD5 Hash failed", AF_INET, skb, "%s L3 index %d",
+				      genhash ? "tcp_v4_calc_md5_hash failed"
+				      : "", l3index);
 		} else {
-			net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
-					genhash ? "failed" : "mismatch",
-					saddr, ntohs(th->source),
-					daddr, ntohs(th->dest), l3index);
+			if (genhash) {
+				tcp_hash_fail("MD5 Hash failed",
+					      AF_INET6, skb, "L3 index %d",
+					      l3index);
+			} else {
+				tcp_hash_fail("MD5 Hash mismatch",
+					      AF_INET6, skb, "L3 index %d",
+					      l3index);
+			}
 		}
 		return SKB_DROP_REASON_TCP_MD5FAILURE;
 	}
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
new file mode 100644
index 0000000000..f8308d3f56
--- /dev/null
+++ b/net/ipv4/tcp_ao.c
@@ -0,0 +1,2396 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET		An implementation of the TCP Authentication Option (TCP-AO).
+ *		See RFC5925.
+ *
+ * Authors:	Dmitry Safonov <dima@arista.com>
+ *		Francesco Ruggeri <fruggeri@arista.com>
+ *		Salam Noureddine <noureddine@arista.com>
+ */
+#define pr_fmt(fmt) "TCP: " fmt
+
+#include <crypto/hash.h>
+#include <linux/inetdevice.h>
+#include <linux/tcp.h>
+
+#include <net/tcp.h>
+#include <net/ipv6.h>
+#include <net/icmp.h>
+
+DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);
+
+int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
+			    unsigned int len, struct tcp_sigpool *hp)
+{
+	struct scatterlist sg;
+	int ret;
+
+	if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp->req),
+				mkt->key, mkt->keylen))
+		goto clear_hash;
+
+	ret = crypto_ahash_init(hp->req);
+	if (ret)
+		goto clear_hash;
+
+	sg_init_one(&sg, ctx, len);
+	ahash_request_set_crypt(hp->req, &sg, key, len);
+	crypto_ahash_update(hp->req);
+
+	ret = crypto_ahash_final(hp->req);
+	if (ret)
+		goto clear_hash;
+
+	return 0;
+clear_hash:
+	memset(key, 0, tcp_ao_digest_size(mkt));
+	return 1;
+}
+
+bool tcp_ao_ignore_icmp(const struct sock *sk, int family, int type, int code)
+{
+	bool ignore_icmp = false;
+	struct tcp_ao_info *ao;
+
+	if (!static_branch_unlikely(&tcp_ao_needed.key))
+		return false;
+
+	/* RFC5925, 7.8:
+	 * >> A TCP-AO implementation MUST default to ignore incoming ICMPv4
+	 * messages of Type 3 (destination unreachable), Codes 2-4 (protocol
+	 * unreachable, port unreachable, and fragmentation needed -- ’hard
+	 * errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
+	 * (administratively prohibited) and Code 4 (port unreachable) intended
+	 * for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
+	 * WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs.
+	 */
+	if (family == AF_INET) {
+		if (type != ICMP_DEST_UNREACH)
+			return false;
+		if (code < ICMP_PROT_UNREACH || code > ICMP_FRAG_NEEDED)
+			return false;
+	} else {
+		if (type != ICMPV6_DEST_UNREACH)
+			return false;
+		if (code != ICMPV6_ADM_PROHIBITED && code != ICMPV6_PORT_UNREACH)
+			return false;
+	}
+
+	rcu_read_lock();
+	switch (sk->sk_state) {
+	case TCP_TIME_WAIT:
+		ao = rcu_dereference(tcp_twsk(sk)->ao_info);
+		break;
+	case TCP_SYN_SENT:
+	case TCP_SYN_RECV:
+	case TCP_LISTEN:
+	case TCP_NEW_SYN_RECV:
+		/* RFC5925 specifies to ignore ICMPs *only* on connections
+		 * in synchronized states.
+		 */
+		rcu_read_unlock();
+		return false;
+	default:
+		ao = rcu_dereference(tcp_sk(sk)->ao_info);
+	}
+
+	if (ao && !ao->accept_icmps) {
+		ignore_icmp = true;
+		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAODROPPEDICMPS);
+		atomic64_inc(&ao->counters.dropped_icmp);
+	}
+	rcu_read_unlock();
+
+	return ignore_icmp;
+}
+
+/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
+ * it's known that the keys in ao_info are matching peer's
+ * family/address/VRF/etc.
+ */
+struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+					  int sndid, int rcvid)
+{
+	struct tcp_ao_key *key;
+
+	hlist_for_each_entry_rcu(key, &ao->head, node) {
+		if ((sndid >= 0 && key->sndid != sndid) ||
+		    (rcvid >= 0 && key->rcvid != rcvid))
+			continue;
+		return key;
+	}
+
+	return NULL;
+}
+
+static int ipv4_prefix_cmp(const struct in_addr *addr1,
+			   const struct in_addr *addr2,
+			   unsigned int prefixlen)
+{
+	__be32 mask = inet_make_mask(prefixlen);
+	__be32 a1 = addr1->s_addr & mask;
+	__be32 a2 = addr2->s_addr & mask;
+
+	if (a1 == a2)
+		return 0;
+	return memcmp(&a1, &a2, sizeof(a1));
+}
+
+static int __tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
+			    const union tcp_ao_addr *addr, u8 prefixlen,
+			    int family, int sndid, int rcvid)
+{
+	if (sndid >= 0 && key->sndid != sndid)
+		return (key->sndid > sndid) ? 1 : -1;
+	if (rcvid >= 0 && key->rcvid != rcvid)
+		return (key->rcvid > rcvid) ? 1 : -1;
+	if (l3index >= 0 && (key->keyflags & TCP_AO_KEYF_IFINDEX)) {
+		if (key->l3index != l3index)
+			return (key->l3index > l3index) ? 1 : -1;
+	}
+
+	if (family == AF_UNSPEC)
+		return 0;
+	if (key->family != family)
+		return (key->family > family) ? 1 : -1;
+
+	if (family == AF_INET) {
+		if (ntohl(key->addr.a4.s_addr) == INADDR_ANY)
+			return 0;
+		if (ntohl(addr->a4.s_addr) == INADDR_ANY)
+			return 0;
+		return ipv4_prefix_cmp(&key->addr.a4, &addr->a4, prefixlen);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else {
+		if (ipv6_addr_any(&key->addr.a6) || ipv6_addr_any(&addr->a6))
+			return 0;
+		if (ipv6_prefix_equal(&key->addr.a6, &addr->a6, prefixlen))
+			return 0;
+		return memcmp(&key->addr.a6, &addr->a6, sizeof(addr->a6));
+#endif
+	}
+	return -1;
+}
+
+static int tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
+			  const union tcp_ao_addr *addr, u8 prefixlen,
+			  int family, int sndid, int rcvid)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) {
+		__be32 addr4 = addr->a6.s6_addr32[3];
+
+		return __tcp_ao_key_cmp(key, l3index,
+					(union tcp_ao_addr *)&addr4,
+					prefixlen, AF_INET, sndid, rcvid);
+	}
+#endif
+	return __tcp_ao_key_cmp(key, l3index, addr,
+				prefixlen, family, sndid, rcvid);
+}
+
+static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk, int l3index,
+		const union tcp_ao_addr *addr, int family, u8 prefix,
+		int sndid, int rcvid)
+{
+	struct tcp_ao_key *key;
+	struct tcp_ao_info *ao;
+
+	if (!static_branch_unlikely(&tcp_ao_needed.key))
+		return NULL;
+
+	ao = rcu_dereference_check(tcp_sk(sk)->ao_info,
+				   lockdep_sock_is_held(sk));
+	if (!ao)
+		return NULL;
+
+	hlist_for_each_entry_rcu(key, &ao->head, node) {
+		u8 prefixlen = min(prefix, key->prefixlen);
+
+		if (!tcp_ao_key_cmp(key, l3index, addr, prefixlen,
+				    family, sndid, rcvid))
+			return key;
+	}
+	return NULL;
+}
+
+struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index,
+				    const union tcp_ao_addr *addr,
+				    int family, int sndid, int rcvid)
+{
+	return __tcp_ao_do_lookup(sk, l3index, addr, family, U8_MAX, sndid, rcvid);
+}
+
+static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags)
+{
+	struct tcp_ao_info *ao;
+
+	ao = kzalloc(sizeof(*ao), flags);
+	if (!ao)
+		return NULL;
+	INIT_HLIST_HEAD(&ao->head);
+	refcount_set(&ao->refcnt, 1);
+
+	return ao;
+}
+
+static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
+{
+	hlist_add_head_rcu(&mkt->node, &ao->head);
+}
+
+static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
+					  struct tcp_ao_key *key)
+{
+	struct tcp_ao_key *new_key;
+
+	new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
+			       GFP_ATOMIC);
+	if (!new_key)
+		return NULL;
+
+	*new_key = *key;
+	INIT_HLIST_NODE(&new_key->node);
+	tcp_sigpool_get(new_key->tcp_sigpool_id);
+	atomic64_set(&new_key->pkt_good, 0);
+	atomic64_set(&new_key->pkt_bad, 0);
+
+	return new_key;
+}
+
+static void tcp_ao_key_free_rcu(struct rcu_head *head)
+{
+	struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
+
+	tcp_sigpool_release(key->tcp_sigpool_id);
+	kfree_sensitive(key);
+}
+
+void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
+{
+	struct tcp_ao_info *ao;
+	struct tcp_ao_key *key;
+	struct hlist_node *n;
+
+	if (twsk) {
+		ao = rcu_dereference_protected(tcp_twsk(sk)->ao_info, 1);
+		tcp_twsk(sk)->ao_info = NULL;
+	} else {
+		ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
+		tcp_sk(sk)->ao_info = NULL;
+	}
+
+	if (!ao || !refcount_dec_and_test(&ao->refcnt))
+		return;
+
+	hlist_for_each_entry_safe(key, n, &ao->head, node) {
+		hlist_del_rcu(&key->node);
+		if (!twsk)
+			atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+		call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+	}
+
+	kfree_rcu(ao, rcu);
+	static_branch_slow_dec_deferred(&tcp_ao_needed);
+}
+
+void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
+{
+	struct tcp_ao_info *ao_info = rcu_dereference_protected(tp->ao_info, 1);
+
+	if (ao_info) {
+		struct tcp_ao_key *key;
+		struct hlist_node *n;
+		int omem = 0;
+
+		hlist_for_each_entry_safe(key, n, &ao_info->head, node) {
+			omem += tcp_ao_sizeof_key(key);
+		}
+
+		refcount_inc(&ao_info->refcnt);
+		atomic_sub(omem, &(((struct sock *)tp)->sk_omem_alloc));
+		rcu_assign_pointer(tcptw->ao_info, ao_info);
+	} else {
+		tcptw->ao_info = NULL;
+	}
+}
+
+/* 4 tuple and ISNs are expected in NBO */
+static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+			      __be32 saddr, __be32 daddr,
+			      __be16 sport, __be16 dport,
+			      __be32 sisn,  __be32 disn)
+{
+	/* See RFC5926 3.1.1 */
+	struct kdf_input_block {
+		u8                      counter;
+		u8                      label[6];
+		struct tcp4_ao_context	ctx;
+		__be16                  outlen;
+	} __packed * tmp;
+	struct tcp_sigpool hp;
+	int err;
+
+	err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
+	if (err)
+		return err;
+
+	tmp = hp.scratch;
+	tmp->counter	= 1;
+	memcpy(tmp->label, "TCP-AO", 6);
+	tmp->ctx.saddr	= saddr;
+	tmp->ctx.daddr	= daddr;
+	tmp->ctx.sport	= sport;
+	tmp->ctx.dport	= dport;
+	tmp->ctx.sisn	= sisn;
+	tmp->ctx.disn	= disn;
+	tmp->outlen	= htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
+
+	err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
+	tcp_sigpool_end(&hp);
+
+	return err;
+}
+
+int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+			  const struct sock *sk,
+			  __be32 sisn, __be32 disn, bool send)
+{
+	if (send)
+		return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr,
+					  sk->sk_daddr, htons(sk->sk_num),
+					  sk->sk_dport, sisn, disn);
+	else
+		return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr,
+					  sk->sk_rcv_saddr, sk->sk_dport,
+					  htons(sk->sk_num), disn, sisn);
+}
+
+static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+			      const struct sock *sk,
+			      __be32 sisn, __be32 disn, bool send)
+{
+	if (mkt->family == AF_INET)
+		return tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (mkt->family == AF_INET6)
+		return tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#endif
+	else
+		return -EOPNOTSUPP;
+}
+
+int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+			   struct request_sock *req)
+{
+	struct inet_request_sock *ireq = inet_rsk(req);
+
+	return tcp_v4_ao_calc_key(mkt, key,
+				  ireq->ir_loc_addr, ireq->ir_rmt_addr,
+				  htons(ireq->ir_num), ireq->ir_rmt_port,
+				  htonl(tcp_rsk(req)->snt_isn),
+				  htonl(tcp_rsk(req)->rcv_isn));
+}
+
+static int tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+				  const struct sk_buff *skb,
+				  __be32 sisn, __be32 disn)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct tcphdr *th = tcp_hdr(skb);
+
+	return tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr,
+				  th->source, th->dest, sisn, disn);
+}
+
+static int tcp_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+			       const struct sk_buff *skb,
+			       __be32 sisn, __be32 disn, int family)
+{
+	if (family == AF_INET)
+		return tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (family == AF_INET6)
+		return tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#endif
+	return -EAFNOSUPPORT;
+}
+
+static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+				       __be32 daddr, __be32 saddr,
+				       int nbytes)
+{
+	struct tcp4_pseudohdr *bp;
+	struct scatterlist sg;
+
+	bp = hp->scratch;
+	bp->saddr = saddr;
+	bp->daddr = daddr;
+	bp->pad = 0;
+	bp->protocol = IPPROTO_TCP;
+	bp->len = cpu_to_be16(nbytes);
+
+	sg_init_one(&sg, bp, sizeof(*bp));
+	ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+	return crypto_ahash_update(hp->req);
+}
+
+static int tcp_ao_hash_pseudoheader(unsigned short int family,
+				    const struct sock *sk,
+				    const struct sk_buff *skb,
+				    struct tcp_sigpool *hp, int nbytes)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+
+	/* TODO: Can we rely on checksum being zero to mean outbound pkt? */
+	if (!th->check) {
+		if (family == AF_INET)
+			return tcp_v4_ao_hash_pseudoheader(hp, sk->sk_daddr,
+					sk->sk_rcv_saddr, skb->len);
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (family == AF_INET6)
+			return tcp_v6_ao_hash_pseudoheader(hp, &sk->sk_v6_daddr,
+					&sk->sk_v6_rcv_saddr, skb->len);
+#endif
+		else
+			return -EAFNOSUPPORT;
+	}
+
+	if (family == AF_INET) {
+		const struct iphdr *iph = ip_hdr(skb);
+
+		return tcp_v4_ao_hash_pseudoheader(hp, iph->daddr,
+				iph->saddr, skb->len);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+		return tcp_v6_ao_hash_pseudoheader(hp, &iph->daddr,
+				&iph->saddr, skb->len);
+#endif
+	}
+	return -EAFNOSUPPORT;
+}
+
+u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq)
+{
+	u32 sne = next_sne;
+
+	if (before(seq, next_seq)) {
+		if (seq > next_seq)
+			sne--;
+	} else {
+		if (seq < next_seq)
+			sne++;
+	}
+
+	return sne;
+}
+
+/* tcp_ao_hash_sne(struct tcp_sigpool *hp)
+ * @hp	- used for hashing
+ * @sne - sne value
+ */
+static int tcp_ao_hash_sne(struct tcp_sigpool *hp, u32 sne)
+{
+	struct scatterlist sg;
+	__be32 *bp;
+
+	bp = (__be32 *)hp->scratch;
+	*bp = htonl(sne);
+
+	sg_init_one(&sg, bp, sizeof(*bp));
+	ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+	return crypto_ahash_update(hp->req);
+}
+
+static int tcp_ao_hash_header(struct tcp_sigpool *hp,
+			      const struct tcphdr *th,
+			      bool exclude_options, u8 *hash,
+			      int hash_offset, int hash_len)
+{
+	int err, len = th->doff << 2;
+	struct scatterlist sg;
+	u8 *hdr = hp->scratch;
+
+	/* We are not allowed to change tcphdr, make a local copy */
+	if (exclude_options) {
+		len = sizeof(*th) + sizeof(struct tcp_ao_hdr) + hash_len;
+		memcpy(hdr, th, sizeof(*th));
+		memcpy(hdr + sizeof(*th),
+		       (u8 *)th + hash_offset - sizeof(struct tcp_ao_hdr),
+		       sizeof(struct tcp_ao_hdr));
+		memset(hdr + sizeof(*th) + sizeof(struct tcp_ao_hdr),
+		       0, hash_len);
+		((struct tcphdr *)hdr)->check = 0;
+	} else {
+		len = th->doff << 2;
+		memcpy(hdr, th, len);
+		/* zero out tcp-ao hash */
+		((struct tcphdr *)hdr)->check = 0;
+		memset(hdr + hash_offset, 0, hash_len);
+	}
+
+	sg_init_one(&sg, hdr, len);
+	ahash_request_set_crypt(hp->req, &sg, NULL, len);
+	err = crypto_ahash_update(hp->req);
+	WARN_ON_ONCE(err != 0);
+	return err;
+}
+
+int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash,
+		    struct tcp_ao_key *key, const u8 *tkey,
+		    const union tcp_ao_addr *daddr,
+		    const union tcp_ao_addr *saddr,
+		    const struct tcphdr *th, u32 sne)
+{
+	int tkey_len = tcp_ao_digest_size(key);
+	int hash_offset = ao_hash - (char *)th;
+	struct tcp_sigpool hp;
+	void *hash_buf = NULL;
+
+	hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
+	if (!hash_buf)
+		goto clear_hash_noput;
+
+	if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
+		goto clear_hash_noput;
+
+	if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
+		goto clear_hash;
+
+	if (crypto_ahash_init(hp.req))
+		goto clear_hash;
+
+	if (tcp_ao_hash_sne(&hp, sne))
+		goto clear_hash;
+	if (family == AF_INET) {
+		if (tcp_v4_ao_hash_pseudoheader(&hp, daddr->a4.s_addr,
+						saddr->a4.s_addr, th->doff * 4))
+			goto clear_hash;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		if (tcp_v6_ao_hash_pseudoheader(&hp, &daddr->a6,
+						&saddr->a6, th->doff * 4))
+			goto clear_hash;
+#endif
+	} else {
+		WARN_ON_ONCE(1);
+		goto clear_hash;
+	}
+	if (tcp_ao_hash_header(&hp, th,
+			       !!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
+			       ao_hash, hash_offset, tcp_ao_maclen(key)))
+		goto clear_hash;
+	ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
+	if (crypto_ahash_final(hp.req))
+		goto clear_hash;
+
+	memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
+	tcp_sigpool_end(&hp);
+	kfree(hash_buf);
+	return 0;
+
+clear_hash:
+	tcp_sigpool_end(&hp);
+clear_hash_noput:
+	memset(ao_hash, 0, tcp_ao_maclen(key));
+	kfree(hash_buf);
+	return 1;
+}
+
+int tcp_ao_hash_skb(unsigned short int family,
+		    char *ao_hash, struct tcp_ao_key *key,
+		    const struct sock *sk, const struct sk_buff *skb,
+		    const u8 *tkey, int hash_offset, u32 sne)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	int tkey_len = tcp_ao_digest_size(key);
+	struct tcp_sigpool hp;
+	void *hash_buf = NULL;
+
+	hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
+	if (!hash_buf)
+		goto clear_hash_noput;
+
+	if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
+		goto clear_hash_noput;
+
+	if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
+		goto clear_hash;
+
+	/* For now use sha1 by default. Depends on alg in tcp_ao_key */
+	if (crypto_ahash_init(hp.req))
+		goto clear_hash;
+
+	if (tcp_ao_hash_sne(&hp, sne))
+		goto clear_hash;
+	if (tcp_ao_hash_pseudoheader(family, sk, skb, &hp, skb->len))
+		goto clear_hash;
+	if (tcp_ao_hash_header(&hp, th,
+			       !!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
+			       ao_hash, hash_offset, tcp_ao_maclen(key)))
+		goto clear_hash;
+	if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
+		goto clear_hash;
+	ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
+	if (crypto_ahash_final(hp.req))
+		goto clear_hash;
+
+	memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
+	tcp_sigpool_end(&hp);
+	kfree(hash_buf);
+	return 0;
+
+clear_hash:
+	tcp_sigpool_end(&hp);
+clear_hash_noput:
+	memset(ao_hash, 0, tcp_ao_maclen(key));
+	kfree(hash_buf);
+	return 1;
+}
+
+int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+		       const struct sock *sk, const struct sk_buff *skb,
+		       const u8 *tkey, int hash_offset, u32 sne)
+{
+	return tcp_ao_hash_skb(AF_INET, ao_hash, key, sk, skb,
+			       tkey, hash_offset, sne);
+}
+
+int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
+			  struct request_sock *req, const struct sk_buff *skb,
+			  int hash_offset, u32 sne)
+{
+	void *hash_buf = NULL;
+	int err;
+
+	hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+	if (!hash_buf)
+		return -ENOMEM;
+
+	err = tcp_v4_ao_calc_key_rsk(ao_key, hash_buf, req);
+	if (err)
+		goto out;
+
+	err = tcp_ao_hash_skb(AF_INET, ao_hash, ao_key, req_to_sk(req), skb,
+			      hash_buf, hash_offset, sne);
+out:
+	kfree(hash_buf);
+	return err;
+}
+
+struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
+					struct request_sock *req,
+					int sndid, int rcvid)
+{
+	struct inet_request_sock *ireq = inet_rsk(req);
+	union tcp_ao_addr *addr = (union tcp_ao_addr *)&ireq->ir_rmt_addr;
+	int l3index;
+
+	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+	return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid);
+}
+
+struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
+				    int sndid, int rcvid)
+{
+	int l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+						     addr_sk->sk_bound_dev_if);
+	union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr;
+
+	return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid);
+}
+
+int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
+			 const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
+			 struct tcp_ao_key **key, char **traffic_key,
+			 bool *allocated_traffic_key, u8 *keyid, u32 *sne)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	struct tcp_ao_info *ao_info;
+
+	*allocated_traffic_key = false;
+	/* If there's no socket - than initial sisn/disn are unknown.
+	 * Drop the segment. RFC5925 (7.7) advises to require graceful
+	 * restart [RFC4724]. Alternatively, the RFC5925 advises to
+	 * save/restore traffic keys before/after reboot.
+	 * Linux TCP-AO support provides TCP_AO_ADD_KEY and TCP_AO_REPAIR
+	 * options to restore a socket post-reboot.
+	 */
+	if (!sk)
+		return -ENOTCONN;
+
+	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
+		unsigned int family = READ_ONCE(sk->sk_family);
+		union tcp_ao_addr *addr;
+		__be32 disn, sisn;
+
+		if (sk->sk_state == TCP_NEW_SYN_RECV) {
+			struct request_sock *req = inet_reqsk(sk);
+
+			sisn = htonl(tcp_rsk(req)->rcv_isn);
+			disn = htonl(tcp_rsk(req)->snt_isn);
+			*sne = tcp_ao_compute_sne(0, tcp_rsk(req)->snt_isn, seq);
+		} else {
+			sisn = th->seq;
+			disn = 0;
+		}
+		if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
+			addr = (union tcp_md5_addr *)&ipv6_hdr(skb)->saddr;
+		else
+			addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (family == AF_INET6 && ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+			family = AF_INET;
+#endif
+
+		sk = sk_const_to_full_sk(sk);
+		ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+		if (!ao_info)
+			return -ENOENT;
+		*key = tcp_ao_do_lookup(sk, l3index, addr, family,
+					-1, aoh->rnext_keyid);
+		if (!*key)
+			return -ENOENT;
+		*traffic_key = kmalloc(tcp_ao_digest_size(*key), GFP_ATOMIC);
+		if (!*traffic_key)
+			return -ENOMEM;
+		*allocated_traffic_key = true;
+		if (tcp_ao_calc_key_skb(*key, *traffic_key, skb,
+					sisn, disn, family))
+			return -1;
+		*keyid = (*key)->rcvid;
+	} else {
+		struct tcp_ao_key *rnext_key;
+		u32 snd_basis;
+
+		if (sk->sk_state == TCP_TIME_WAIT) {
+			ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
+			snd_basis = tcp_twsk(sk)->tw_snd_nxt;
+		} else {
+			ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+			snd_basis = tcp_sk(sk)->snd_una;
+		}
+		if (!ao_info)
+			return -ENOENT;
+
+		*key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+		if (!*key)
+			return -ENOENT;
+		*traffic_key = snd_other_key(*key);
+		rnext_key = READ_ONCE(ao_info->rnext_key);
+		*keyid = rnext_key->rcvid;
+		*sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
+					  snd_basis, seq);
+	}
+	return 0;
+}
+
+int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
+			struct tcp_ao_key *key, struct tcphdr *th,
+			__u8 *hash_location)
+{
+	struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_ao_info *ao;
+	void *tkey_buf = NULL;
+	u8 *traffic_key;
+	u32 sne;
+
+	ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+				       lockdep_sock_is_held(sk));
+	traffic_key = snd_other_key(key);
+	if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
+		__be32 disn;
+
+		if (!(tcb->tcp_flags & TCPHDR_ACK)) {
+			disn = 0;
+			tkey_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
+			if (!tkey_buf)
+				return -ENOMEM;
+			traffic_key = tkey_buf;
+		} else {
+			disn = ao->risn;
+		}
+		tp->af_specific->ao_calc_key_sk(key, traffic_key,
+						sk, ao->lisn, disn, true);
+	}
+	sne = tcp_ao_compute_sne(READ_ONCE(ao->snd_sne), READ_ONCE(tp->snd_una),
+				 ntohl(th->seq));
+	tp->af_specific->calc_ao_hash(hash_location, key, sk, skb, traffic_key,
+				      hash_location - (u8 *)th, sne);
+	kfree(tkey_buf);
+	return 0;
+}
+
+static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,
+		const struct sock *sk, const struct sk_buff *skb,
+		int sndid, int rcvid, int l3index)
+{
+	if (family == AF_INET) {
+		const struct iphdr *iph = ip_hdr(skb);
+
+		return tcp_ao_do_lookup(sk, l3index,
+					(union tcp_ao_addr *)&iph->saddr,
+					AF_INET, sndid, rcvid);
+	} else {
+		const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+		return tcp_ao_do_lookup(sk, l3index,
+					(union tcp_ao_addr *)&iph->saddr,
+					AF_INET6, sndid, rcvid);
+	}
+}
+
+void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+		      struct tcp_request_sock *treq,
+		      unsigned short int family, int l3index)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	const struct tcp_ao_hdr *aoh;
+	struct tcp_ao_key *key;
+
+	treq->used_tcp_ao = false;
+
+	if (tcp_parse_auth_options(th, NULL, &aoh) || !aoh)
+		return;
+
+	key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
+	if (!key)
+		/* Key not found, continue without TCP-AO */
+		return;
+
+	treq->ao_rcv_next = aoh->keyid;
+	treq->ao_keyid = aoh->rnext_keyid;
+	treq->used_tcp_ao = true;
+}
+
+static enum skb_drop_reason
+tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
+		   unsigned short int family, struct tcp_ao_info *info,
+		   const struct tcp_ao_hdr *aoh, struct tcp_ao_key *key,
+		   u8 *traffic_key, u8 *phash, u32 sne, int l3index)
+{
+	u8 maclen = aoh->length - sizeof(struct tcp_ao_hdr);
+	const struct tcphdr *th = tcp_hdr(skb);
+	void *hash_buf = NULL;
+
+	if (maclen != tcp_ao_maclen(key)) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+		atomic64_inc(&info->counters.pkt_bad);
+		atomic64_inc(&key->pkt_bad);
+		tcp_hash_fail("AO hash wrong length", family, skb,
+			      "%u != %d L3index: %d", maclen,
+			      tcp_ao_maclen(key), l3index);
+		return SKB_DROP_REASON_TCP_AOFAILURE;
+	}
+
+	hash_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
+	if (!hash_buf)
+		return SKB_DROP_REASON_NOT_SPECIFIED;
+
+	/* XXX: make it per-AF callback? */
+	tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
+			(phash - (u8 *)th), sne);
+	if (memcmp(phash, hash_buf, maclen)) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+		atomic64_inc(&info->counters.pkt_bad);
+		atomic64_inc(&key->pkt_bad);
+		tcp_hash_fail("AO hash mismatch", family, skb,
+			      "L3index: %d", l3index);
+		kfree(hash_buf);
+		return SKB_DROP_REASON_TCP_AOFAILURE;
+	}
+	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOGOOD);
+	atomic64_inc(&info->counters.pkt_good);
+	atomic64_inc(&key->pkt_good);
+	kfree(hash_buf);
+	return SKB_NOT_DROPPED_YET;
+}
+
+enum skb_drop_reason
+tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
+		    unsigned short int family, const struct request_sock *req,
+		    int l3index, const struct tcp_ao_hdr *aoh)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	u8 *phash = (u8 *)(aoh + 1); /* hash goes just after the header */
+	struct tcp_ao_info *info;
+	enum skb_drop_reason ret;
+	struct tcp_ao_key *key;
+	__be32 sisn, disn;
+	u8 *traffic_key;
+	u32 sne = 0;
+
+	info = rcu_dereference(tcp_sk(sk)->ao_info);
+	if (!info) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
+		tcp_hash_fail("AO key not found", family, skb,
+			      "keyid: %u L3index: %d", aoh->keyid, l3index);
+		return SKB_DROP_REASON_TCP_AOUNEXPECTED;
+	}
+
+	if (unlikely(th->syn)) {
+		sisn = th->seq;
+		disn = 0;
+	}
+
+	/* Fast-path */
+	if (likely((1 << sk->sk_state) & TCP_AO_ESTABLISHED)) {
+		enum skb_drop_reason err;
+		struct tcp_ao_key *current_key;
+
+		/* Check if this socket's rnext_key matches the keyid in the
+		 * packet. If not we lookup the key based on the keyid
+		 * matching the rcvid in the mkt.
+		 */
+		key = READ_ONCE(info->rnext_key);
+		if (key->rcvid != aoh->keyid) {
+			key = tcp_ao_established_key(info, -1, aoh->keyid);
+			if (!key)
+				goto key_not_found;
+		}
+
+		/* Delayed retransmitted SYN */
+		if (unlikely(th->syn && !th->ack))
+			goto verify_hash;
+
+		sne = tcp_ao_compute_sne(info->rcv_sne, tcp_sk(sk)->rcv_nxt,
+					 ntohl(th->seq));
+		/* Established socket, traffic key are cached */
+		traffic_key = rcv_other_key(key);
+		err = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
+					 traffic_key, phash, sne, l3index);
+		if (err)
+			return err;
+		current_key = READ_ONCE(info->current_key);
+		/* Key rotation: the peer asks us to use new key (RNext) */
+		if (unlikely(aoh->rnext_keyid != current_key->sndid)) {
+			/* If the key is not found we do nothing. */
+			key = tcp_ao_established_key(info, aoh->rnext_keyid, -1);
+			if (key)
+				/* pairs with tcp_ao_del_cmd */
+				WRITE_ONCE(info->current_key, key);
+		}
+		return SKB_NOT_DROPPED_YET;
+	}
+
+	/* Lookup key based on peer address and keyid.
+	 * current_key and rnext_key must not be used on tcp listen
+	 * sockets as otherwise:
+	 * - request sockets would race on those key pointers
+	 * - tcp_ao_del_cmd() allows async key removal
+	 */
+	key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
+	if (!key)
+		goto key_not_found;
+
+	if (th->syn && !th->ack)
+		goto verify_hash;
+
+	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
+		/* Make the initial syn the likely case here */
+		if (unlikely(req)) {
+			sne = tcp_ao_compute_sne(0, tcp_rsk(req)->rcv_isn,
+						 ntohl(th->seq));
+			sisn = htonl(tcp_rsk(req)->rcv_isn);
+			disn = htonl(tcp_rsk(req)->snt_isn);
+		} else if (unlikely(th->ack && !th->syn)) {
+			/* Possible syncookie packet */
+			sisn = htonl(ntohl(th->seq) - 1);
+			disn = htonl(ntohl(th->ack_seq) - 1);
+			sne = tcp_ao_compute_sne(0, ntohl(sisn),
+						 ntohl(th->seq));
+		} else if (unlikely(!th->syn)) {
+			/* no way to figure out initial sisn/disn - drop */
+			return SKB_DROP_REASON_TCP_FLAGS;
+		}
+	} else if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		disn = info->lisn;
+		if (th->syn || th->rst)
+			sisn = th->seq;
+		else
+			sisn = info->risn;
+	} else {
+		WARN_ONCE(1, "TCP-AO: Unexpected sk_state %d", sk->sk_state);
+		return SKB_DROP_REASON_TCP_AOFAILURE;
+	}
+verify_hash:
+	traffic_key = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
+	if (!traffic_key)
+		return SKB_DROP_REASON_NOT_SPECIFIED;
+	tcp_ao_calc_key_skb(key, traffic_key, skb, sisn, disn, family);
+	ret = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
+				 traffic_key, phash, sne, l3index);
+	kfree(traffic_key);
+	return ret;
+
+key_not_found:
+	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
+	atomic64_inc(&info->counters.key_not_found);
+	tcp_hash_fail("Requested by the peer AO key id not found",
+		      family, skb, "L3index: %d", l3index);
+	return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
+}
+
+static int tcp_ao_cache_traffic_keys(const struct sock *sk,
+				     struct tcp_ao_info *ao,
+				     struct tcp_ao_key *ao_key)
+{
+	u8 *traffic_key = snd_other_key(ao_key);
+	int ret;
+
+	ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+				 ao->lisn, ao->risn, true);
+	if (ret)
+		return ret;
+
+	traffic_key = rcv_other_key(ao_key);
+	ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+				 ao->lisn, ao->risn, false);
+	return ret;
+}
+
+void tcp_ao_connect_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_ao_info *ao_info;
+	union tcp_ao_addr *addr;
+	struct tcp_ao_key *key;
+	int family, l3index;
+
+	ao_info = rcu_dereference_protected(tp->ao_info,
+					    lockdep_sock_is_held(sk));
+	if (!ao_info)
+		return;
+
+	/* Remove all keys that don't match the peer */
+	family = sk->sk_family;
+	if (family == AF_INET)
+		addr = (union tcp_ao_addr *)&sk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (family == AF_INET6)
+		addr = (union tcp_ao_addr *)&sk->sk_v6_daddr;
+#endif
+	else
+		return;
+	l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+						 sk->sk_bound_dev_if);
+
+	hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+		if (!tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1))
+			continue;
+
+		if (key == ao_info->current_key)
+			ao_info->current_key = NULL;
+		if (key == ao_info->rnext_key)
+			ao_info->rnext_key = NULL;
+		hlist_del_rcu(&key->node);
+		atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+		call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+	}
+
+	key = tp->af_specific->ao_lookup(sk, sk, -1, -1);
+	if (key) {
+		/* if current_key or rnext_key were not provided,
+		 * use the first key matching the peer
+		 */
+		if (!ao_info->current_key)
+			ao_info->current_key = key;
+		if (!ao_info->rnext_key)
+			ao_info->rnext_key = key;
+		tp->tcp_header_len += tcp_ao_len_aligned(key);
+
+		ao_info->lisn = htonl(tp->write_seq);
+		ao_info->snd_sne = 0;
+	} else {
+		/* Can't happen: tcp_connect() verifies that there's
+		 * at least one tcp-ao key that matches the remote peer.
+		 */
+		WARN_ON_ONCE(1);
+		rcu_assign_pointer(tp->ao_info, NULL);
+		kfree(ao_info);
+	}
+}
+
+void tcp_ao_established(struct sock *sk)
+{
+	struct tcp_ao_info *ao;
+	struct tcp_ao_key *key;
+
+	ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+				       lockdep_sock_is_held(sk));
+	if (!ao)
+		return;
+
+	hlist_for_each_entry_rcu(key, &ao->head, node)
+		tcp_ao_cache_traffic_keys(sk, ao, key);
+}
+
+void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_ao_info *ao;
+	struct tcp_ao_key *key;
+
+	ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+				       lockdep_sock_is_held(sk));
+	if (!ao)
+		return;
+
+	WRITE_ONCE(ao->risn, tcp_hdr(skb)->seq);
+	ao->rcv_sne = 0;
+
+	hlist_for_each_entry_rcu(key, &ao->head, node)
+		tcp_ao_cache_traffic_keys(sk, ao, key);
+}
+
+int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
+			     struct request_sock *req, struct sk_buff *skb,
+			     int family)
+{
+	struct tcp_ao_key *key, *new_key, *first_key;
+	struct tcp_ao_info *new_ao, *ao;
+	struct hlist_node *key_head;
+	int l3index, ret = -ENOMEM;
+	union tcp_ao_addr *addr;
+	bool match = false;
+
+	ao = rcu_dereference(tcp_sk(sk)->ao_info);
+	if (!ao)
+		return 0;
+
+	/* New socket without TCP-AO on it */
+	if (!tcp_rsk_used_ao(req))
+		return 0;
+
+	new_ao = tcp_ao_alloc_info(GFP_ATOMIC);
+	if (!new_ao)
+		return -ENOMEM;
+	new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
+	new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
+	new_ao->ao_required = ao->ao_required;
+	new_ao->accept_icmps = ao->accept_icmps;
+
+	if (family == AF_INET) {
+		addr = (union tcp_ao_addr *)&newsk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		addr = (union tcp_ao_addr *)&newsk->sk_v6_daddr;
+#endif
+	} else {
+		ret = -EAFNOSUPPORT;
+		goto free_ao;
+	}
+	l3index = l3mdev_master_ifindex_by_index(sock_net(newsk),
+						 newsk->sk_bound_dev_if);
+
+	hlist_for_each_entry_rcu(key, &ao->head, node) {
+		if (tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1))
+			continue;
+
+		new_key = tcp_ao_copy_key(newsk, key);
+		if (!new_key)
+			goto free_and_exit;
+
+		tcp_ao_cache_traffic_keys(newsk, new_ao, new_key);
+		tcp_ao_link_mkt(new_ao, new_key);
+		match = true;
+	}
+
+	if (!match) {
+		/* RFC5925 (7.4.1) specifies that the TCP-AO status
+		 * of a connection is determined on the initial SYN.
+		 * At this point the connection was TCP-AO enabled, so
+		 * it can't switch to being unsigned if peer's key
+		 * disappears on the listening socket.
+		 */
+		ret = -EKEYREJECTED;
+		goto free_and_exit;
+	}
+
+	if (!static_key_fast_inc_not_disabled(&tcp_ao_needed.key.key)) {
+		ret = -EUSERS;
+		goto free_and_exit;
+	}
+
+	key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
+	first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
+
+	key = tcp_ao_established_key(new_ao, tcp_rsk(req)->ao_keyid, -1);
+	if (key)
+		new_ao->current_key = key;
+	else
+		new_ao->current_key = first_key;
+
+	/* set rnext_key */
+	key = tcp_ao_established_key(new_ao, -1, tcp_rsk(req)->ao_rcv_next);
+	if (key)
+		new_ao->rnext_key = key;
+	else
+		new_ao->rnext_key = first_key;
+
+	sk_gso_disable(newsk);
+	rcu_assign_pointer(tcp_sk(newsk)->ao_info, new_ao);
+
+	return 0;
+
+free_and_exit:
+	hlist_for_each_entry_safe(key, key_head, &new_ao->head, node) {
+		hlist_del(&key->node);
+		tcp_sigpool_release(key->tcp_sigpool_id);
+		atomic_sub(tcp_ao_sizeof_key(key), &newsk->sk_omem_alloc);
+		kfree_sensitive(key);
+	}
+free_ao:
+	kfree(new_ao);
+	return ret;
+}
+
+static bool tcp_ao_can_set_current_rnext(struct sock *sk)
+{
+	/* There aren't current/rnext keys on TCP_LISTEN sockets */
+	if (sk->sk_state == TCP_LISTEN)
+		return false;
+	return true;
+}
+
+static int tcp_ao_verify_ipv4(struct sock *sk, struct tcp_ao_add *cmd,
+			      union tcp_ao_addr **addr)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)&cmd->addr;
+	struct inet_sock *inet = inet_sk(sk);
+
+	if (sin->sin_family != AF_INET)
+		return -EINVAL;
+
+	/* Currently matching is not performed on port (or port ranges) */
+	if (sin->sin_port != 0)
+		return -EINVAL;
+
+	/* Check prefix and trailing 0's in addr */
+	if (cmd->prefix != 0) {
+		__be32 mask;
+
+		if (ntohl(sin->sin_addr.s_addr) == INADDR_ANY)
+			return -EINVAL;
+		if (cmd->prefix > 32)
+			return -EINVAL;
+
+		mask = inet_make_mask(cmd->prefix);
+		if (sin->sin_addr.s_addr & ~mask)
+			return -EINVAL;
+
+		/* Check that MKT address is consistent with socket */
+		if (ntohl(inet->inet_daddr) != INADDR_ANY &&
+		    (inet->inet_daddr & mask) != sin->sin_addr.s_addr)
+			return -EINVAL;
+	} else {
+		if (ntohl(sin->sin_addr.s_addr) != INADDR_ANY)
+			return -EINVAL;
+	}
+
+	*addr = (union tcp_ao_addr *)&sin->sin_addr;
+	return 0;
+}
+
+static int tcp_ao_parse_crypto(struct tcp_ao_add *cmd, struct tcp_ao_key *key)
+{
+	unsigned int syn_tcp_option_space;
+	bool is_kdf_aes_128_cmac = false;
+	struct crypto_ahash *tfm;
+	struct tcp_sigpool hp;
+	void *tmp_key = NULL;
+	int err;
+
+	/* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
+	if (!strcmp("cmac(aes128)", cmd->alg_name)) {
+		strscpy(cmd->alg_name, "cmac(aes)", sizeof(cmd->alg_name));
+		is_kdf_aes_128_cmac = (cmd->keylen != 16);
+		tmp_key = kmalloc(cmd->keylen, GFP_KERNEL);
+		if (!tmp_key)
+			return -ENOMEM;
+	}
+
+	key->maclen = cmd->maclen ?: 12; /* 12 is the default in RFC5925 */
+
+	/* Check: maclen + tcp-ao header <= (MAX_TCP_OPTION_SPACE - mss
+	 *					- tstamp (including sackperm)
+	 *					- wscale),
+	 * see tcp_syn_options(), tcp_synack_options(), commit 33ad798c924b.
+	 *
+	 * In order to allow D-SACK with TCP-AO, the header size should be:
+	 * (MAX_TCP_OPTION_SPACE - TCPOLEN_TSTAMP_ALIGNED
+	 *			- TCPOLEN_SACK_BASE_ALIGNED
+	 *			- 2 * TCPOLEN_SACK_PERBLOCK) = 8 (maclen = 4),
+	 * see tcp_established_options().
+	 *
+	 * RFC5925, 2.2:
+	 * Typical MACs are 96-128 bits (12-16 bytes), but any length
+	 * that fits in the header of the segment being authenticated
+	 * is allowed.
+	 *
+	 * RFC5925, 7.6:
+	 * TCP-AO continues to consume 16 bytes in non-SYN segments,
+	 * leaving a total of 24 bytes for other options, of which
+	 * the timestamp consumes 10.  This leaves 14 bytes, of which 10
+	 * are used for a single SACK block. When two SACK blocks are used,
+	 * such as to handle D-SACK, a smaller TCP-AO MAC would be required
+	 * to make room for the additional SACK block (i.e., to leave 18
+	 * bytes for the D-SACK variant of the SACK option) [RFC2883].
+	 * Note that D-SACK is not supportable in TCP MD5 in the presence
+	 * of timestamps, because TCP MD5’s MAC length is fixed and too
+	 * large to leave sufficient option space.
+	 */
+	syn_tcp_option_space = MAX_TCP_OPTION_SPACE;
+	syn_tcp_option_space -= TCPOLEN_MSS_ALIGNED;
+	syn_tcp_option_space -= TCPOLEN_TSTAMP_ALIGNED;
+	syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
+	if (tcp_ao_len_aligned(key) > syn_tcp_option_space) {
+		err = -EMSGSIZE;
+		goto err_kfree;
+	}
+
+	key->keylen = cmd->keylen;
+	memcpy(key->key, cmd->key, cmd->keylen);
+
+	err = tcp_sigpool_start(key->tcp_sigpool_id, &hp);
+	if (err)
+		goto err_kfree;
+
+	tfm = crypto_ahash_reqtfm(hp.req);
+	if (is_kdf_aes_128_cmac) {
+		void *scratch = hp.scratch;
+		struct scatterlist sg;
+
+		memcpy(tmp_key, cmd->key, cmd->keylen);
+		sg_init_one(&sg, tmp_key, cmd->keylen);
+
+		/* Using zero-key of 16 bytes as described in RFC5926 */
+		memset(scratch, 0, 16);
+		err = crypto_ahash_setkey(tfm, scratch, 16);
+		if (err)
+			goto err_pool_end;
+
+		err = crypto_ahash_init(hp.req);
+		if (err)
+			goto err_pool_end;
+
+		ahash_request_set_crypt(hp.req, &sg, key->key, cmd->keylen);
+		err = crypto_ahash_update(hp.req);
+		if (err)
+			goto err_pool_end;
+
+		err |= crypto_ahash_final(hp.req);
+		if (err)
+			goto err_pool_end;
+		key->keylen = 16;
+	}
+
+	err = crypto_ahash_setkey(tfm, key->key, key->keylen);
+	if (err)
+		goto err_pool_end;
+
+	tcp_sigpool_end(&hp);
+	kfree_sensitive(tmp_key);
+
+	if (tcp_ao_maclen(key) > key->digest_size)
+		return -EINVAL;
+
+	return 0;
+
+err_pool_end:
+	tcp_sigpool_end(&hp);
+err_kfree:
+	kfree_sensitive(tmp_key);
+	return err;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
+			      union tcp_ao_addr **paddr,
+			      unsigned short int *family)
+{
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd->addr;
+	struct in6_addr *addr = &sin6->sin6_addr;
+	u8 prefix = cmd->prefix;
+
+	if (sin6->sin6_family != AF_INET6)
+		return -EINVAL;
+
+	/* Currently matching is not performed on port (or port ranges) */
+	if (sin6->sin6_port != 0)
+		return -EINVAL;
+
+	/* Check prefix and trailing 0's in addr */
+	if (cmd->prefix != 0 && ipv6_addr_v4mapped(addr)) {
+		__be32 addr4 = addr->s6_addr32[3];
+		__be32 mask;
+
+		if (prefix > 32 || ntohl(addr4) == INADDR_ANY)
+			return -EINVAL;
+
+		mask = inet_make_mask(prefix);
+		if (addr4 & ~mask)
+			return -EINVAL;
+
+		/* Check that MKT address is consistent with socket */
+		if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
+			__be32 daddr4 = sk->sk_v6_daddr.s6_addr32[3];
+
+			if (!ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+				return -EINVAL;
+			if ((daddr4 & mask) != addr4)
+				return -EINVAL;
+		}
+
+		*paddr = (union tcp_ao_addr *)&addr->s6_addr32[3];
+		*family = AF_INET;
+		return 0;
+	} else if (cmd->prefix != 0) {
+		struct in6_addr pfx;
+
+		if (ipv6_addr_any(addr) || prefix > 128)
+			return -EINVAL;
+
+		ipv6_addr_prefix(&pfx, addr, prefix);
+		if (ipv6_addr_cmp(&pfx, addr))
+			return -EINVAL;
+
+		/* Check that MKT address is consistent with socket */
+		if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
+		    !ipv6_prefix_equal(&sk->sk_v6_daddr, addr, prefix))
+
+			return -EINVAL;
+	} else {
+		if (!ipv6_addr_any(addr))
+			return -EINVAL;
+	}
+
+	*paddr = (union tcp_ao_addr *)addr;
+	return 0;
+}
+#else
+static int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
+			      union tcp_ao_addr **paddr,
+			      unsigned short int *family)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
+{
+	if (sk_fullsock(sk)) {
+		return rcu_dereference_protected(tcp_sk(sk)->ao_info,
+						 lockdep_sock_is_held(sk));
+	} else if (sk->sk_state == TCP_TIME_WAIT) {
+		return rcu_dereference_protected(tcp_twsk(sk)->ao_info,
+						 lockdep_sock_is_held(sk));
+	}
+	return ERR_PTR(-ESOCKTNOSUPPORT);
+}
+
+static struct tcp_ao_info *getsockopt_ao_info(struct sock *sk)
+{
+	if (sk_fullsock(sk))
+		return rcu_dereference(tcp_sk(sk)->ao_info);
+	else if (sk->sk_state == TCP_TIME_WAIT)
+		return rcu_dereference(tcp_twsk(sk)->ao_info);
+
+	return ERR_PTR(-ESOCKTNOSUPPORT);
+}
+
+#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_IFINDEX | TCP_AO_KEYF_EXCLUDE_OPT)
+#define TCP_AO_GET_KEYF_VALID	(TCP_AO_KEYF_IFINDEX)
+
+static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
+					   struct tcp_ao_add *cmd)
+{
+	const char *algo = cmd->alg_name;
+	unsigned int digest_size;
+	struct crypto_ahash *tfm;
+	struct tcp_ao_key *key;
+	struct tcp_sigpool hp;
+	int err, pool_id;
+	size_t size;
+
+	/* Force null-termination of alg_name */
+	cmd->alg_name[ARRAY_SIZE(cmd->alg_name) - 1] = '\0';
+
+	/* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
+	if (!strcmp("cmac(aes128)", algo))
+		algo = "cmac(aes)";
+
+	/* Full TCP header (th->doff << 2) should fit into scratch area,
+	 * see tcp_ao_hash_header().
+	 */
+	pool_id = tcp_sigpool_alloc_ahash(algo, 60);
+	if (pool_id < 0)
+		return ERR_PTR(pool_id);
+
+	err = tcp_sigpool_start(pool_id, &hp);
+	if (err)
+		goto err_free_pool;
+
+	tfm = crypto_ahash_reqtfm(hp.req);
+	digest_size = crypto_ahash_digestsize(tfm);
+	tcp_sigpool_end(&hp);
+
+	size = sizeof(struct tcp_ao_key) + (digest_size << 1);
+	key = sock_kmalloc(sk, size, GFP_KERNEL);
+	if (!key) {
+		err = -ENOMEM;
+		goto err_free_pool;
+	}
+
+	key->tcp_sigpool_id = pool_id;
+	key->digest_size = digest_size;
+	return key;
+
+err_free_pool:
+	tcp_sigpool_release(pool_id);
+	return ERR_PTR(err);
+}
+
+static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
+			  sockptr_t optval, int optlen)
+{
+	struct tcp_ao_info *ao_info;
+	union tcp_ao_addr *addr;
+	struct tcp_ao_key *key;
+	struct tcp_ao_add cmd;
+	int ret, l3index = 0;
+	bool first = false;
+
+	if (optlen < sizeof(cmd))
+		return -EINVAL;
+
+	ret = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+	if (ret)
+		return ret;
+
+	if (cmd.keylen > TCP_AO_MAXKEYLEN)
+		return -EINVAL;
+
+	if (cmd.reserved != 0 || cmd.reserved2 != 0)
+		return -EINVAL;
+
+	if (family == AF_INET)
+		ret = tcp_ao_verify_ipv4(sk, &cmd, &addr);
+	else
+		ret = tcp_ao_verify_ipv6(sk, &cmd, &addr, &family);
+	if (ret)
+		return ret;
+
+	if (cmd.keyflags & ~TCP_AO_KEYF_ALL)
+		return -EINVAL;
+
+	if (cmd.set_current || cmd.set_rnext) {
+		if (!tcp_ao_can_set_current_rnext(sk))
+			return -EINVAL;
+	}
+
+	if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
+		return -EINVAL;
+
+	/* For cmd.tcp_ifindex = 0 the key will apply to the default VRF */
+	if (cmd.keyflags & TCP_AO_KEYF_IFINDEX && cmd.ifindex) {
+		int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+		struct net_device *dev;
+
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(sock_net(sk), cmd.ifindex);
+		if (dev && netif_is_l3_master(dev))
+			l3index = dev->ifindex;
+		rcu_read_unlock();
+
+		if (!dev || !l3index)
+			return -EINVAL;
+
+		if (!bound_dev_if || bound_dev_if != cmd.ifindex) {
+			/* tcp_ao_established_key() doesn't expect having
+			 * non peer-matching key on an established TCP-AO
+			 * connection.
+			 */
+			if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
+				return -EINVAL;
+		}
+
+		/* It's still possible to bind after adding keys or even
+		 * re-bind to a different dev (with CAP_NET_RAW).
+		 * So, no reason to return error here, rather try to be
+		 * nice and warn the user.
+		 */
+		if (bound_dev_if && bound_dev_if != cmd.ifindex)
+			net_warn_ratelimited("AO key ifindex %d != sk bound ifindex %d\n",
+					     cmd.ifindex, bound_dev_if);
+	}
+
+	/* Don't allow keys for peers that have a matching TCP-MD5 key */
+	if (cmd.keyflags & TCP_AO_KEYF_IFINDEX) {
+		/* Non-_exact version of tcp_md5_do_lookup() will
+		 * as well match keys that aren't bound to a specific VRF
+		 * (that will make them match AO key with
+		 * sysctl_tcp_l3dev_accept = 1
+		 */
+		if (tcp_md5_do_lookup(sk, l3index, addr, family))
+			return -EKEYREJECTED;
+	} else {
+		if (tcp_md5_do_lookup_any_l3index(sk, addr, family))
+			return -EKEYREJECTED;
+	}
+
+	ao_info = setsockopt_ao_info(sk);
+	if (IS_ERR(ao_info))
+		return PTR_ERR(ao_info);
+
+	if (!ao_info) {
+		ao_info = tcp_ao_alloc_info(GFP_KERNEL);
+		if (!ao_info)
+			return -ENOMEM;
+		first = true;
+	} else {
+		/* Check that neither RecvID nor SendID match any
+		 * existing key for the peer, RFC5925 3.1:
+		 * > The IDs of MKTs MUST NOT overlap where their
+		 * > TCP connection identifiers overlap.
+		 */
+		if (__tcp_ao_do_lookup(sk, l3index, addr, family, cmd.prefix, -1, cmd.rcvid))
+			return -EEXIST;
+		if (__tcp_ao_do_lookup(sk, l3index, addr, family,
+				       cmd.prefix, cmd.sndid, -1))
+			return -EEXIST;
+	}
+
+	key = tcp_ao_key_alloc(sk, &cmd);
+	if (IS_ERR(key)) {
+		ret = PTR_ERR(key);
+		goto err_free_ao;
+	}
+
+	INIT_HLIST_NODE(&key->node);
+	memcpy(&key->addr, addr, (family == AF_INET) ? sizeof(struct in_addr) :
+						       sizeof(struct in6_addr));
+	key->prefixlen	= cmd.prefix;
+	key->family	= family;
+	key->keyflags	= cmd.keyflags;
+	key->sndid	= cmd.sndid;
+	key->rcvid	= cmd.rcvid;
+	key->l3index	= l3index;
+	atomic64_set(&key->pkt_good, 0);
+	atomic64_set(&key->pkt_bad, 0);
+
+	ret = tcp_ao_parse_crypto(&cmd, key);
+	if (ret < 0)
+		goto err_free_sock;
+
+	if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) {
+		tcp_ao_cache_traffic_keys(sk, ao_info, key);
+		if (first) {
+			ao_info->current_key = key;
+			ao_info->rnext_key = key;
+		}
+	}
+
+	tcp_ao_link_mkt(ao_info, key);
+	if (first) {
+		if (!static_branch_inc(&tcp_ao_needed.key)) {
+			ret = -EUSERS;
+			goto err_free_sock;
+		}
+		sk_gso_disable(sk);
+		rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
+	}
+
+	if (cmd.set_current)
+		WRITE_ONCE(ao_info->current_key, key);
+	if (cmd.set_rnext)
+		WRITE_ONCE(ao_info->rnext_key, key);
+	return 0;
+
+err_free_sock:
+	atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+	tcp_sigpool_release(key->tcp_sigpool_id);
+	kfree_sensitive(key);
+err_free_ao:
+	if (first)
+		kfree(ao_info);
+	return ret;
+}
+
+static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
+			     bool del_async, struct tcp_ao_key *key,
+			     struct tcp_ao_key *new_current,
+			     struct tcp_ao_key *new_rnext)
+{
+	int err;
+
+	hlist_del_rcu(&key->node);
+
+	/* Support for async delete on listening sockets: as they don't
+	 * need current_key/rnext_key maintaining, we don't need to check
+	 * them and we can just free all resources in RCU fashion.
+	 */
+	if (del_async) {
+		atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+		call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+		return 0;
+	}
+
+	/* At this moment another CPU could have looked this key up
+	 * while it was unlinked from the list. Wait for RCU grace period,
+	 * after which the key is off-list and can't be looked up again;
+	 * the rx path [just before RCU came] might have used it and set it
+	 * as current_key (very unlikely).
+	 * Free the key with next RCU grace period (in case it was
+	 * current_key before tcp_ao_current_rnext() might have
+	 * changed it in forced-delete).
+	 */
+	synchronize_rcu();
+	if (new_current)
+		WRITE_ONCE(ao_info->current_key, new_current);
+	if (new_rnext)
+		WRITE_ONCE(ao_info->rnext_key, new_rnext);
+
+	if (unlikely(READ_ONCE(ao_info->current_key) == key ||
+		     READ_ONCE(ao_info->rnext_key) == key)) {
+		err = -EBUSY;
+		goto add_key;
+	}
+
+	atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+	call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+
+	return 0;
+add_key:
+	hlist_add_head_rcu(&key->node, &ao_info->head);
+	return err;
+}
+
+#define TCP_AO_DEL_KEYF_ALL (TCP_AO_KEYF_IFINDEX)
+static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
+			  sockptr_t optval, int optlen)
+{
+	struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
+	int err, addr_len, l3index = 0;
+	struct tcp_ao_info *ao_info;
+	union tcp_ao_addr *addr;
+	struct tcp_ao_del cmd;
+	__u8 prefix;
+	u16 port;
+
+	if (optlen < sizeof(cmd))
+		return -EINVAL;
+
+	err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+	if (err)
+		return err;
+
+	if (cmd.reserved != 0 || cmd.reserved2 != 0)
+		return -EINVAL;
+
+	if (cmd.set_current || cmd.set_rnext) {
+		if (!tcp_ao_can_set_current_rnext(sk))
+			return -EINVAL;
+	}
+
+	if (cmd.keyflags & ~TCP_AO_DEL_KEYF_ALL)
+		return -EINVAL;
+
+	/* No sanity check for TCP_AO_KEYF_IFINDEX as if a VRF
+	 * was destroyed, there still should be a way to delete keys,
+	 * that were bound to that l3intf. So, fail late at lookup stage
+	 * if there is no key for that ifindex.
+	 */
+	if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
+		return -EINVAL;
+
+	ao_info = setsockopt_ao_info(sk);
+	if (IS_ERR(ao_info))
+		return PTR_ERR(ao_info);
+	if (!ao_info)
+		return -ENOENT;
+
+	/* For sockets in TCP_CLOSED it's possible set keys that aren't
+	 * matching the future peer (address/VRF/etc),
+	 * tcp_ao_connect_init() will choose a correct matching MKT
+	 * if there's any.
+	 */
+	if (cmd.set_current) {
+		new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
+		if (!new_current)
+			return -ENOENT;
+	}
+	if (cmd.set_rnext) {
+		new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
+		if (!new_rnext)
+			return -ENOENT;
+	}
+	if (cmd.del_async && sk->sk_state != TCP_LISTEN)
+		return -EINVAL;
+
+	if (family == AF_INET) {
+		struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
+
+		addr = (union tcp_ao_addr *)&sin->sin_addr;
+		addr_len = sizeof(struct in_addr);
+		port = ntohs(sin->sin_port);
+	} else {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.addr;
+		struct in6_addr *addr6 = &sin6->sin6_addr;
+
+		if (ipv6_addr_v4mapped(addr6)) {
+			addr = (union tcp_ao_addr *)&addr6->s6_addr32[3];
+			addr_len = sizeof(struct in_addr);
+			family = AF_INET;
+		} else {
+			addr = (union tcp_ao_addr *)addr6;
+			addr_len = sizeof(struct in6_addr);
+		}
+		port = ntohs(sin6->sin6_port);
+	}
+	prefix = cmd.prefix;
+
+	/* Currently matching is not performed on port (or port ranges) */
+	if (port != 0)
+		return -EINVAL;
+
+	/* We could choose random present key here for current/rnext
+	 * but that's less predictable. Let's be strict and don't
+	 * allow removing a key that's in use. RFC5925 doesn't
+	 * specify how-to coordinate key removal, but says:
+	 * "It is presumed that an MKT affecting a particular
+	 * connection cannot be destroyed during an active connection"
+	 */
+	hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+		if (cmd.sndid != key->sndid ||
+		    cmd.rcvid != key->rcvid)
+			continue;
+
+		if (family != key->family ||
+		    prefix != key->prefixlen ||
+		    memcmp(addr, &key->addr, addr_len))
+			continue;
+
+		if ((cmd.keyflags & TCP_AO_KEYF_IFINDEX) !=
+		    (key->keyflags & TCP_AO_KEYF_IFINDEX))
+			continue;
+
+		if (key->l3index != l3index)
+			continue;
+
+		if (key == new_current || key == new_rnext)
+			continue;
+
+		return tcp_ao_delete_key(sk, ao_info, cmd.del_async, key,
+					 new_current, new_rnext);
+	}
+	return -ENOENT;
+}
+
+/* cmd.ao_required makes a socket TCP-AO only.
+ * Don't allow any md5 keys for any l3intf on the socket together with it.
+ * Restricting it early in setsockopt() removes a check for
+ * ao_info->ao_required on inbound tcp segment fast-path.
+ */
+static int tcp_ao_required_verify(struct sock *sk)
+{
+#ifdef CONFIG_TCP_MD5SIG
+	const struct tcp_md5sig_info *md5sig;
+
+	if (!static_branch_unlikely(&tcp_md5_needed.key))
+		return 0;
+
+	md5sig = rcu_dereference_check(tcp_sk(sk)->md5sig_info,
+				       lockdep_sock_is_held(sk));
+	if (!md5sig)
+		return 0;
+
+	if (rcu_dereference_check(hlist_first_rcu(&md5sig->head),
+				  lockdep_sock_is_held(sk)))
+		return 1;
+#endif
+	return 0;
+}
+
+static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
+			   sockptr_t optval, int optlen)
+{
+	struct tcp_ao_key *new_current = NULL, *new_rnext = NULL;
+	struct tcp_ao_info *ao_info;
+	struct tcp_ao_info_opt cmd;
+	bool first = false;
+	int err;
+
+	if (optlen < sizeof(cmd))
+		return -EINVAL;
+
+	err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+	if (err)
+		return err;
+
+	if (cmd.set_current || cmd.set_rnext) {
+		if (!tcp_ao_can_set_current_rnext(sk))
+			return -EINVAL;
+	}
+
+	if (cmd.reserved != 0 || cmd.reserved2 != 0)
+		return -EINVAL;
+
+	ao_info = setsockopt_ao_info(sk);
+	if (IS_ERR(ao_info))
+		return PTR_ERR(ao_info);
+	if (!ao_info) {
+		if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
+			return -EINVAL;
+		ao_info = tcp_ao_alloc_info(GFP_KERNEL);
+		if (!ao_info)
+			return -ENOMEM;
+		first = true;
+	}
+
+	if (cmd.ao_required && tcp_ao_required_verify(sk))
+		return -EKEYREJECTED;
+
+	/* For sockets in TCP_CLOSED it's possible set keys that aren't
+	 * matching the future peer (address/port/VRF/etc),
+	 * tcp_ao_connect_init() will choose a correct matching MKT
+	 * if there's any.
+	 */
+	if (cmd.set_current) {
+		new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
+		if (!new_current) {
+			err = -ENOENT;
+			goto out;
+		}
+	}
+	if (cmd.set_rnext) {
+		new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
+		if (!new_rnext) {
+			err = -ENOENT;
+			goto out;
+		}
+	}
+	if (cmd.set_counters) {
+		atomic64_set(&ao_info->counters.pkt_good, cmd.pkt_good);
+		atomic64_set(&ao_info->counters.pkt_bad, cmd.pkt_bad);
+		atomic64_set(&ao_info->counters.key_not_found, cmd.pkt_key_not_found);
+		atomic64_set(&ao_info->counters.ao_required, cmd.pkt_ao_required);
+		atomic64_set(&ao_info->counters.dropped_icmp, cmd.pkt_dropped_icmp);
+	}
+
+	ao_info->ao_required = cmd.ao_required;
+	ao_info->accept_icmps = cmd.accept_icmps;
+	if (new_current)
+		WRITE_ONCE(ao_info->current_key, new_current);
+	if (new_rnext)
+		WRITE_ONCE(ao_info->rnext_key, new_rnext);
+	if (first) {
+		if (!static_branch_inc(&tcp_ao_needed.key)) {
+			err = -EUSERS;
+			goto out;
+		}
+		sk_gso_disable(sk);
+		rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
+	}
+	return 0;
+out:
+	if (first)
+		kfree(ao_info);
+	return err;
+}
+
+int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
+		 sockptr_t optval, int optlen)
+{
+	if (WARN_ON_ONCE(family != AF_INET && family != AF_INET6))
+		return -EAFNOSUPPORT;
+
+	switch (cmd) {
+	case TCP_AO_ADD_KEY:
+		return tcp_ao_add_cmd(sk, family, optval, optlen);
+	case TCP_AO_DEL_KEY:
+		return tcp_ao_del_cmd(sk, family, optval, optlen);
+	case TCP_AO_INFO:
+		return tcp_ao_info_cmd(sk, family, optval, optlen);
+	default:
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+}
+
+int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen)
+{
+	return tcp_parse_ao(sk, cmd, AF_INET, optval, optlen);
+}
+
+/* tcp_ao_copy_mkts_to_user(ao_info, optval, optlen)
+ *
+ * @ao_info:	struct tcp_ao_info on the socket that
+ *		socket getsockopt(TCP_AO_GET_KEYS) is executed on
+ * @optval:	pointer to array of tcp_ao_getsockopt structures in user space.
+ *		Must be != NULL.
+ * @optlen:	pointer to size of tcp_ao_getsockopt structure.
+ *		Must be != NULL.
+ *
+ * Return value: 0 on success, a negative error number otherwise.
+ *
+ * optval points to an array of tcp_ao_getsockopt structures in user space.
+ * optval[0] is used as both input and output to getsockopt. It determines
+ * which keys are returned by the kernel.
+ * optval[0].nkeys is the size of the array in user space. On return it contains
+ * the number of keys matching the search criteria.
+ * If tcp_ao_getsockopt::get_all is set, then all keys in the socket are
+ * returned, otherwise only keys matching <addr, prefix, sndid, rcvid>
+ * in optval[0] are returned.
+ * optlen is also used as both input and output. The user provides the size
+ * of struct tcp_ao_getsockopt in user space, and the kernel returns the size
+ * of the structure in kernel space.
+ * The size of struct tcp_ao_getsockopt may differ between user and kernel.
+ * There are three cases to consider:
+ *  * If usize == ksize, then keys are copied verbatim.
+ *  * If usize < ksize, then the userspace has passed an old struct to a
+ *    newer kernel. The rest of the trailing bytes in optval[0]
+ *    (ksize - usize) are interpreted as 0 by the kernel.
+ *  * If usize > ksize, then the userspace has passed a new struct to an
+ *    older kernel. The trailing bytes unknown to the kernel (usize - ksize)
+ *    are checked to ensure they are zeroed, otherwise -E2BIG is returned.
+ * On return the kernel fills in min(usize, ksize) in each entry of the array.
+ * The layout of the fields in the user and kernel structures is expected to
+ * be the same (including in the 32bit vs 64bit case).
+ */
+static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
+				    sockptr_t optval, sockptr_t optlen)
+{
+	struct tcp_ao_getsockopt opt_in, opt_out;
+	struct tcp_ao_key *key, *current_key;
+	bool do_address_matching = true;
+	union tcp_ao_addr *addr = NULL;
+	int err, l3index, user_len;
+	unsigned int max_keys;	/* maximum number of keys to copy to user */
+	size_t out_offset = 0;
+	size_t bytes_to_write;	/* number of bytes to write to user level */
+	u32 matched_keys;	/* keys from ao_info matched so far */
+	int optlen_out;
+	__be16 port = 0;
+
+	if (copy_from_sockptr(&user_len, optlen, sizeof(int)))
+		return -EFAULT;
+
+	if (user_len <= 0)
+		return -EINVAL;
+
+	memset(&opt_in, 0, sizeof(struct tcp_ao_getsockopt));
+	err = copy_struct_from_sockptr(&opt_in, sizeof(opt_in),
+				       optval, user_len);
+	if (err < 0)
+		return err;
+
+	if (opt_in.pkt_good || opt_in.pkt_bad)
+		return -EINVAL;
+	if (opt_in.keyflags & ~TCP_AO_GET_KEYF_VALID)
+		return -EINVAL;
+	if (opt_in.ifindex && !(opt_in.keyflags & TCP_AO_KEYF_IFINDEX))
+		return -EINVAL;
+
+	if (opt_in.reserved != 0)
+		return -EINVAL;
+
+	max_keys = opt_in.nkeys;
+	l3index = (opt_in.keyflags & TCP_AO_KEYF_IFINDEX) ? opt_in.ifindex : -1;
+
+	if (opt_in.get_all || opt_in.is_current || opt_in.is_rnext) {
+		if (opt_in.get_all && (opt_in.is_current || opt_in.is_rnext))
+			return -EINVAL;
+		do_address_matching = false;
+	}
+
+	switch (opt_in.addr.ss_family) {
+	case AF_INET: {
+		struct sockaddr_in *sin;
+		__be32 mask;
+
+		sin = (struct sockaddr_in *)&opt_in.addr;
+		port = sin->sin_port;
+		addr = (union tcp_ao_addr *)&sin->sin_addr;
+
+		if (opt_in.prefix > 32)
+			return -EINVAL;
+
+		if (ntohl(sin->sin_addr.s_addr) == INADDR_ANY &&
+		    opt_in.prefix != 0)
+			return -EINVAL;
+
+		mask = inet_make_mask(opt_in.prefix);
+		if (sin->sin_addr.s_addr & ~mask)
+			return -EINVAL;
+
+		break;
+	}
+	case AF_INET6: {
+		struct sockaddr_in6 *sin6;
+		struct in6_addr *addr6;
+
+		sin6 = (struct sockaddr_in6 *)&opt_in.addr;
+		addr = (union tcp_ao_addr *)&sin6->sin6_addr;
+		addr6 = &sin6->sin6_addr;
+		port = sin6->sin6_port;
+
+		/* We don't have to change family and @addr here if
+		 * ipv6_addr_v4mapped() like in key adding:
+		 * tcp_ao_key_cmp() does it. Do the sanity checks though.
+		 */
+		if (opt_in.prefix != 0) {
+			if (ipv6_addr_v4mapped(addr6)) {
+				__be32 mask, addr4 = addr6->s6_addr32[3];
+
+				if (opt_in.prefix > 32 ||
+				    ntohl(addr4) == INADDR_ANY)
+					return -EINVAL;
+				mask = inet_make_mask(opt_in.prefix);
+				if (addr4 & ~mask)
+					return -EINVAL;
+			} else {
+				struct in6_addr pfx;
+
+				if (ipv6_addr_any(addr6) ||
+				    opt_in.prefix > 128)
+					return -EINVAL;
+
+				ipv6_addr_prefix(&pfx, addr6, opt_in.prefix);
+				if (ipv6_addr_cmp(&pfx, addr6))
+					return -EINVAL;
+			}
+		} else if (!ipv6_addr_any(addr6)) {
+			return -EINVAL;
+		}
+		break;
+	}
+	case 0:
+		if (!do_address_matching)
+			break;
+		fallthrough;
+	default:
+		return -EAFNOSUPPORT;
+	}
+
+	if (!do_address_matching) {
+		/* We could just ignore those, but let's do stricter checks */
+		if (addr || port)
+			return -EINVAL;
+		if (opt_in.prefix || opt_in.sndid || opt_in.rcvid)
+			return -EINVAL;
+	}
+
+	bytes_to_write = min_t(int, user_len, sizeof(struct tcp_ao_getsockopt));
+	matched_keys = 0;
+	/* May change in RX, while we're dumping, pre-fetch it */
+	current_key = READ_ONCE(ao_info->current_key);
+
+	hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+		if (opt_in.get_all)
+			goto match;
+
+		if (opt_in.is_current || opt_in.is_rnext) {
+			if (opt_in.is_current && key == current_key)
+				goto match;
+			if (opt_in.is_rnext && key == ao_info->rnext_key)
+				goto match;
+			continue;
+		}
+
+		if (tcp_ao_key_cmp(key, l3index, addr, opt_in.prefix,
+				   opt_in.addr.ss_family,
+				   opt_in.sndid, opt_in.rcvid) != 0)
+			continue;
+match:
+		matched_keys++;
+		if (matched_keys > max_keys)
+			continue;
+
+		memset(&opt_out, 0, sizeof(struct tcp_ao_getsockopt));
+
+		if (key->family == AF_INET) {
+			struct sockaddr_in *sin_out = (struct sockaddr_in *)&opt_out.addr;
+
+			sin_out->sin_family = key->family;
+			sin_out->sin_port = 0;
+			memcpy(&sin_out->sin_addr, &key->addr, sizeof(struct in_addr));
+		} else {
+			struct sockaddr_in6 *sin6_out = (struct sockaddr_in6 *)&opt_out.addr;
+
+			sin6_out->sin6_family = key->family;
+			sin6_out->sin6_port = 0;
+			memcpy(&sin6_out->sin6_addr, &key->addr, sizeof(struct in6_addr));
+		}
+		opt_out.sndid = key->sndid;
+		opt_out.rcvid = key->rcvid;
+		opt_out.prefix = key->prefixlen;
+		opt_out.keyflags = key->keyflags;
+		opt_out.is_current = (key == current_key);
+		opt_out.is_rnext = (key == ao_info->rnext_key);
+		opt_out.nkeys = 0;
+		opt_out.maclen = key->maclen;
+		opt_out.keylen = key->keylen;
+		opt_out.ifindex = key->l3index;
+		opt_out.pkt_good = atomic64_read(&key->pkt_good);
+		opt_out.pkt_bad = atomic64_read(&key->pkt_bad);
+		memcpy(&opt_out.key, key->key, key->keylen);
+		tcp_sigpool_algo(key->tcp_sigpool_id, opt_out.alg_name, 64);
+
+		/* Copy key to user */
+		if (copy_to_sockptr_offset(optval, out_offset,
+					   &opt_out, bytes_to_write))
+			return -EFAULT;
+		out_offset += user_len;
+	}
+
+	optlen_out = (int)sizeof(struct tcp_ao_getsockopt);
+	if (copy_to_sockptr(optlen, &optlen_out, sizeof(int)))
+		return -EFAULT;
+
+	out_offset = offsetof(struct tcp_ao_getsockopt, nkeys);
+	if (copy_to_sockptr_offset(optval, out_offset,
+				   &matched_keys, sizeof(u32)))
+		return -EFAULT;
+
+	return 0;
+}
+
+int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+	struct tcp_ao_info *ao_info;
+
+	ao_info = setsockopt_ao_info(sk);
+	if (IS_ERR(ao_info))
+		return PTR_ERR(ao_info);
+	if (!ao_info)
+		return -ENOENT;
+
+	return tcp_ao_copy_mkts_to_user(ao_info, optval, optlen);
+}
+
+int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+	struct tcp_ao_info_opt out, in = {};
+	struct tcp_ao_key *current_key;
+	struct tcp_ao_info *ao;
+	int err, len;
+
+	if (copy_from_sockptr(&len, optlen, sizeof(int)))
+		return -EFAULT;
+
+	if (len <= 0)
+		return -EINVAL;
+
+	/* Copying this "in" only to check ::reserved, ::reserved2,
+	 * that may be needed to extend (struct tcp_ao_info_opt) and
+	 * what getsockopt() provides in future.
+	 */
+	err = copy_struct_from_sockptr(&in, sizeof(in), optval, len);
+	if (err)
+		return err;
+
+	if (in.reserved != 0 || in.reserved2 != 0)
+		return -EINVAL;
+
+	ao = setsockopt_ao_info(sk);
+	if (IS_ERR(ao))
+		return PTR_ERR(ao);
+	if (!ao)
+		return -ENOENT;
+
+	memset(&out, 0, sizeof(out));
+	out.ao_required		= ao->ao_required;
+	out.accept_icmps	= ao->accept_icmps;
+	out.pkt_good		= atomic64_read(&ao->counters.pkt_good);
+	out.pkt_bad		= atomic64_read(&ao->counters.pkt_bad);
+	out.pkt_key_not_found	= atomic64_read(&ao->counters.key_not_found);
+	out.pkt_ao_required	= atomic64_read(&ao->counters.ao_required);
+	out.pkt_dropped_icmp	= atomic64_read(&ao->counters.dropped_icmp);
+
+	current_key = READ_ONCE(ao->current_key);
+	if (current_key) {
+		out.set_current = 1;
+		out.current_key = current_key->sndid;
+	}
+	if (ao->rnext_key) {
+		out.set_rnext = 1;
+		out.rnext = ao->rnext_key->rcvid;
+	}
+
+	if (copy_to_sockptr(optval, &out, min_t(int, len, sizeof(out))))
+		return -EFAULT;
+
+	return 0;
+}
+
+int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_ao_repair cmd;
+	struct tcp_ao_key *key;
+	struct tcp_ao_info *ao;
+	int err;
+
+	if (optlen < sizeof(cmd))
+		return -EINVAL;
+
+	err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+	if (err)
+		return err;
+
+	if (!tp->repair)
+		return -EPERM;
+
+	ao = setsockopt_ao_info(sk);
+	if (IS_ERR(ao))
+		return PTR_ERR(ao);
+	if (!ao)
+		return -ENOENT;
+
+	WRITE_ONCE(ao->lisn, cmd.snt_isn);
+	WRITE_ONCE(ao->risn, cmd.rcv_isn);
+	WRITE_ONCE(ao->snd_sne, cmd.snd_sne);
+	WRITE_ONCE(ao->rcv_sne, cmd.rcv_sne);
+
+	hlist_for_each_entry_rcu(key, &ao->head, node)
+		tcp_ao_cache_traffic_keys(sk, ao, key);
+
+	return 0;
+}
+
+int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_ao_repair opt;
+	struct tcp_ao_info *ao;
+	int len;
+
+	if (copy_from_sockptr(&len, optlen, sizeof(int)))
+		return -EFAULT;
+
+	if (len <= 0)
+		return -EINVAL;
+
+	if (!tp->repair)
+		return -EPERM;
+
+	rcu_read_lock();
+	ao = getsockopt_ao_info(sk);
+	if (IS_ERR_OR_NULL(ao)) {
+		rcu_read_unlock();
+		return ao ? PTR_ERR(ao) : -ENOENT;
+	}
+
+	opt.snt_isn	= ao->lisn;
+	opt.rcv_isn	= ao->risn;
+	opt.snd_sne	= READ_ONCE(ao->snd_sne);
+	opt.rcv_sne	= READ_ONCE(ao->rcv_sne);
+	rcu_read_unlock();
+
+	if (copy_to_sockptr(optval, &opt, min_t(int, len, sizeof(opt))))
+		return -EFAULT;
+	return 0;
+}
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 146792cd26..22358032dd 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -258,7 +258,7 @@ static unsigned long bbr_bw_to_pacing_rate(struct sock *sk, u32 bw, int gain)
 	u64 rate = bw;
 
 	rate = bbr_rate_bytes_per_sec(sk, rate, gain);
-	rate = min_t(u64, rate, sk->sk_max_pacing_rate);
+	rate = min_t(u64, rate, READ_ONCE(sk->sk_max_pacing_rate));
 	return rate;
 }
 
@@ -278,7 +278,8 @@ static void bbr_init_pacing_rate_from_rtt(struct sock *sk)
 	}
 	bw = (u64)tcp_snd_cwnd(tp) * BW_UNIT;
 	do_div(bw, rtt_us);
-	sk->sk_pacing_rate = bbr_bw_to_pacing_rate(sk, bw, bbr_high_gain);
+	WRITE_ONCE(sk->sk_pacing_rate,
+		   bbr_bw_to_pacing_rate(sk, bw, bbr_high_gain));
 }
 
 /* Pace using current bw estimate and a gain factor. */
@@ -290,14 +291,14 @@ static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain)
 
 	if (unlikely(!bbr->has_seen_rtt && tp->srtt_us))
 		bbr_init_pacing_rate_from_rtt(sk);
-	if (bbr_full_bw_reached(sk) || rate > sk->sk_pacing_rate)
-		sk->sk_pacing_rate = rate;
+	if (bbr_full_bw_reached(sk) || rate > READ_ONCE(sk->sk_pacing_rate))
+		WRITE_ONCE(sk->sk_pacing_rate, rate);
 }
 
 /* override sysctl_tcp_min_tso_segs */
 __bpf_kfunc static u32 bbr_min_tso_segs(struct sock *sk)
 {
-	return sk->sk_pacing_rate < (bbr_min_tso_rate >> 3) ? 1 : 2;
+	return READ_ONCE(sk->sk_pacing_rate) < (bbr_min_tso_rate >> 3) ? 1 : 2;
 }
 
 static u32 bbr_tso_segs_goal(struct sock *sk)
@@ -309,7 +310,7 @@ static u32 bbr_tso_segs_goal(struct sock *sk)
 	 * driver provided sk_gso_max_size.
 	 */
 	bytes = min_t(unsigned long,
-		      sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift),
+		      READ_ONCE(sk->sk_pacing_rate) >> READ_ONCE(sk->sk_pacing_shift),
 		      GSO_LEGACY_MAX_SIZE - 1 - MAX_TCP_HEADER);
 	segs = max_t(u32, bytes / tp->mss_cache, bbr_min_tso_segs(sk));
 
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 01b50fa791..4cbe4b4442 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -247,4 +247,5 @@ static void __exit tcp_diag_exit(void)
 module_init(tcp_diag_init);
 module_exit(tcp_diag_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP socket monitoring via SOCK_DIAG");
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e6c4929549..701cb87043 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -693,6 +693,23 @@ new_measure:
 	tp->rcv_rtt_est.time = tp->tcp_mstamp;
 }
 
+static s32 tcp_rtt_tsopt_us(const struct tcp_sock *tp)
+{
+	u32 delta, delta_us;
+
+	delta = tcp_time_stamp_ts(tp) - tp->rx_opt.rcv_tsecr;
+	if (tp->tcp_usec_ts)
+		return delta;
+
+	if (likely(delta < INT_MAX / (USEC_PER_SEC / TCP_TS_HZ))) {
+		if (!delta)
+			delta = 1;
+		delta_us = delta * (USEC_PER_SEC / TCP_TS_HZ);
+		return delta_us;
+	}
+	return -1;
+}
+
 static inline void tcp_rcv_rtt_measure_ts(struct sock *sk,
 					  const struct sk_buff *skb)
 {
@@ -704,15 +721,10 @@ static inline void tcp_rcv_rtt_measure_ts(struct sock *sk,
 
 	if (TCP_SKB_CB(skb)->end_seq -
 	    TCP_SKB_CB(skb)->seq >= inet_csk(sk)->icsk_ack.rcv_mss) {
-		u32 delta = tcp_time_stamp(tp) - tp->rx_opt.rcv_tsecr;
-		u32 delta_us;
-
-		if (likely(delta < INT_MAX / (USEC_PER_SEC / TCP_TS_HZ))) {
-			if (!delta)
-				delta = 1;
-			delta_us = delta * (USEC_PER_SEC / TCP_TS_HZ);
-			tcp_rcv_rtt_update(tp, delta_us, 0);
-		}
+		s32 delta = tcp_rtt_tsopt_us(tp);
+
+		if (delta >= 0)
+			tcp_rcv_rtt_update(tp, delta, 0);
 	}
 }
 
@@ -778,6 +790,16 @@ new_measure:
 	tp->rcvq_space.time = tp->tcp_mstamp;
 }
 
+static void tcp_save_lrcv_flowlabel(struct sock *sk, const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (skb->protocol == htons(ETH_P_IPV6))
+		icsk->icsk_ack.lrcv_flowlabel = ntohl(ip6_flowlabel(ipv6_hdr(skb)));
+#endif
+}
+
 /* There is something which you must keep in mind when you analyze the
  * behavior of the tp->ato delayed ack timeout interval.  When a
  * connection starts up, we want to ack as quickly as possible.  The
@@ -826,6 +848,7 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb)
 		}
 	}
 	icsk->icsk_ack.lrcvtime = now;
+	tcp_save_lrcv_flowlabel(sk, skb);
 
 	tcp_ecn_check_ce(sk, skb);
 
@@ -940,8 +963,8 @@ static void tcp_update_pacing_rate(struct sock *sk)
 	 * without any lock. We want to make sure compiler wont store
 	 * intermediate values in this location.
 	 */
-	WRITE_ONCE(sk->sk_pacing_rate, min_t(u64, rate,
-					     sk->sk_max_pacing_rate));
+	WRITE_ONCE(sk->sk_pacing_rate,
+		   min_t(u64, rate, READ_ONCE(sk->sk_max_pacing_rate)));
 }
 
 /* Calculate rto without backoff.  This is the second half of Van Jacobson's
@@ -2101,6 +2124,10 @@ void tcp_clear_retrans(struct tcp_sock *tp)
 	tp->undo_marker = 0;
 	tp->undo_retrans = -1;
 	tp->sacked_out = 0;
+	tp->rto_stamp = 0;
+	tp->total_rto = 0;
+	tp->total_rto_recoveries = 0;
+	tp->total_rto_time = 0;
 }
 
 static inline void tcp_init_undo(struct tcp_sock *tp)
@@ -2428,7 +2455,7 @@ static bool tcp_skb_spurious_retrans(const struct tcp_sock *tp,
 				     const struct sk_buff *skb)
 {
 	return (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS) &&
-	       tcp_tsopt_ecr_before(tp, tcp_skb_timestamp(skb));
+	       tcp_tsopt_ecr_before(tp, tcp_skb_timestamp_ts(tp->tcp_usec_ts, skb));
 }
 
 /* Nothing was retransmitted or returned timestamp is less
@@ -2839,6 +2866,14 @@ void tcp_enter_recovery(struct sock *sk, bool ece_ack)
 	tcp_set_ca_state(sk, TCP_CA_Recovery);
 }
 
+static void tcp_update_rto_time(struct tcp_sock *tp)
+{
+	if (tp->rto_stamp) {
+		tp->total_rto_time += tcp_time_stamp_ms(tp) - tp->rto_stamp;
+		tp->rto_stamp = 0;
+	}
+}
+
 /* Process an ACK in CA_Loss state. Move to CA_Open if lost data are
  * recovered or spurious. Otherwise retransmits more on partial ACKs.
  */
@@ -3043,6 +3078,8 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
 		break;
 	case TCP_CA_Loss:
 		tcp_process_loss(sk, flag, num_dupack, rexmit);
+		if (icsk->icsk_ca_state != TCP_CA_Loss)
+			tcp_update_rto_time(tp);
 		tcp_identify_packet_loss(sk, ack_flag);
 		if (!(icsk->icsk_ca_state == TCP_CA_Open ||
 		      (*ack_flag & FLAG_LOST_RETRANS)))
@@ -3122,17 +3159,10 @@ static bool tcp_ack_update_rtt(struct sock *sk, const int flag,
 	 * left edge of the send window.
 	 * See draft-ietf-tcplw-high-performance-00, section 3.3.
 	 */
-	if (seq_rtt_us < 0 && tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
-	    flag & FLAG_ACKED) {
-		u32 delta = tcp_time_stamp(tp) - tp->rx_opt.rcv_tsecr;
-
-		if (likely(delta < INT_MAX / (USEC_PER_SEC / TCP_TS_HZ))) {
-			if (!delta)
-				delta = 1;
-			seq_rtt_us = delta * (USEC_PER_SEC / TCP_TS_HZ);
-			ca_rtt_us = seq_rtt_us;
-		}
-	}
+	if (seq_rtt_us < 0 && tp->rx_opt.saw_tstamp &&
+	    tp->rx_opt.rcv_tsecr && flag & FLAG_ACKED)
+		seq_rtt_us = ca_rtt_us = tcp_rtt_tsopt_us(tp);
+
 	rs->rtt_us = ca_rtt_us; /* RTT of last (S)ACKed packet (or -1) */
 	if (seq_rtt_us < 0)
 		return false;
@@ -3542,6 +3572,21 @@ static inline bool tcp_may_update_window(const struct tcp_sock *tp,
 		(ack_seq == tp->snd_wl1 && (nwin > tp->snd_wnd || !nwin));
 }
 
+static void tcp_snd_sne_update(struct tcp_sock *tp, u32 ack)
+{
+#ifdef CONFIG_TCP_AO
+	struct tcp_ao_info *ao;
+
+	if (!static_branch_unlikely(&tcp_ao_needed.key))
+		return;
+
+	ao = rcu_dereference_protected(tp->ao_info,
+				       lockdep_sock_is_held((struct sock *)tp));
+	if (ao && ack < tp->snd_una)
+		ao->snd_sne++;
+#endif
+}
+
 /* If we update tp->snd_una, also update tp->bytes_acked */
 static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
 {
@@ -3549,9 +3594,25 @@ static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
 
 	sock_owned_by_me((struct sock *)tp);
 	tp->bytes_acked += delta;
+	tcp_snd_sne_update(tp, ack);
 	tp->snd_una = ack;
 }
 
+static void tcp_rcv_sne_update(struct tcp_sock *tp, u32 seq)
+{
+#ifdef CONFIG_TCP_AO
+	struct tcp_ao_info *ao;
+
+	if (!static_branch_unlikely(&tcp_ao_needed.key))
+		return;
+
+	ao = rcu_dereference_protected(tp->ao_info,
+				       lockdep_sock_is_held((struct sock *)tp));
+	if (ao && seq < tp->rcv_nxt)
+		ao->rcv_sne++;
+#endif
+}
+
 /* If we update tp->rcv_nxt, also update tp->bytes_received */
 static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq)
 {
@@ -3559,6 +3620,7 @@ static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq)
 
 	sock_owned_by_me((struct sock *)tp);
 	tp->bytes_received += delta;
+	tcp_rcv_sne_update(tp, seq);
 	WRITE_ONCE(tp->rcv_nxt, seq);
 }
 
@@ -4229,39 +4291,58 @@ static bool tcp_fast_parse_options(const struct net *net,
 	return true;
 }
 
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 /*
- * Parse MD5 Signature option
+ * Parse Signature options
  */
-const u8 *tcp_parse_md5sig_option(const struct tcphdr *th)
+int tcp_do_parse_auth_options(const struct tcphdr *th,
+			      const u8 **md5_hash, const u8 **ao_hash)
 {
 	int length = (th->doff << 2) - sizeof(*th);
 	const u8 *ptr = (const u8 *)(th + 1);
+	unsigned int minlen = TCPOLEN_MD5SIG;
+
+	if (IS_ENABLED(CONFIG_TCP_AO))
+		minlen = sizeof(struct tcp_ao_hdr) + 1;
+
+	*md5_hash = NULL;
+	*ao_hash = NULL;
 
 	/* If not enough data remaining, we can short cut */
-	while (length >= TCPOLEN_MD5SIG) {
+	while (length >= minlen) {
 		int opcode = *ptr++;
 		int opsize;
 
 		switch (opcode) {
 		case TCPOPT_EOL:
-			return NULL;
+			return 0;
 		case TCPOPT_NOP:
 			length--;
 			continue;
 		default:
 			opsize = *ptr++;
 			if (opsize < 2 || opsize > length)
-				return NULL;
-			if (opcode == TCPOPT_MD5SIG)
-				return opsize == TCPOLEN_MD5SIG ? ptr : NULL;
+				return -EINVAL;
+			if (opcode == TCPOPT_MD5SIG) {
+				if (opsize != TCPOLEN_MD5SIG)
+					return -EINVAL;
+				if (unlikely(*md5_hash || *ao_hash))
+					return -EEXIST;
+				*md5_hash = ptr;
+			} else if (opcode == TCPOPT_AO) {
+				if (opsize <= sizeof(struct tcp_ao_hdr))
+					return -EINVAL;
+				if (unlikely(*md5_hash || *ao_hash))
+					return -EEXIST;
+				*ao_hash = ptr;
+			}
 		}
 		ptr += opsize - 2;
 		length -= opsize;
 	}
-	return NULL;
+	return 0;
 }
-EXPORT_SYMBOL(tcp_parse_md5sig_option);
+EXPORT_SYMBOL(tcp_do_parse_auth_options);
 #endif
 
 /* Sorry, PAWS as specified is broken wrt. pure-ACKs -DaveM
@@ -4287,6 +4368,23 @@ EXPORT_SYMBOL(tcp_parse_md5sig_option);
  * up to bandwidth of 18Gigabit/sec. 8) ]
  */
 
+/* Estimates max number of increments of remote peer TSval in
+ * a replay window (based on our current RTO estimation).
+ */
+static u32 tcp_tsval_replay(const struct sock *sk)
+{
+	/* If we use usec TS resolution,
+	 * then expect the remote peer to use the same resolution.
+	 */
+	if (tcp_sk(sk)->tcp_usec_ts)
+		return inet_csk(sk)->icsk_rto * (USEC_PER_SEC / HZ);
+
+	/* RFC 7323 recommends a TSval clock between 1ms and 1sec.
+	 * We know that some OS (including old linux) can use 1200 Hz.
+	 */
+	return inet_csk(sk)->icsk_rto * 1200 / HZ;
+}
+
 static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
@@ -4294,7 +4392,7 @@ static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
 	u32 seq = TCP_SKB_CB(skb)->seq;
 	u32 ack = TCP_SKB_CB(skb)->ack_seq;
 
-	return (/* 1. Pure ACK with correct sequence number. */
+	return	/* 1. Pure ACK with correct sequence number. */
 		(th->ack && seq == TCP_SKB_CB(skb)->end_seq && seq == tp->rcv_nxt) &&
 
 		/* 2. ... and duplicate ACK. */
@@ -4304,7 +4402,8 @@ static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
 		!tcp_may_update_window(tp, ack, seq, ntohs(th->window) << tp->rx_opt.snd_wscale) &&
 
 		/* 4. ... and sits in replay window. */
-		(s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <= (inet_csk(sk)->icsk_rto * 1024) / HZ);
+		(s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <=
+		tcp_tsval_replay(sk);
 }
 
 static inline bool tcp_paws_discard(const struct sock *sk,
@@ -4504,12 +4603,23 @@ static void tcp_rcv_spurious_retrans(struct sock *sk, const struct sk_buff *skb)
 {
 	/* When the ACK path fails or drops most ACKs, the sender would
 	 * timeout and spuriously retransmit the same segment repeatedly.
-	 * The receiver remembers and reflects via DSACKs. Leverage the
-	 * DSACK state and change the txhash to re-route speculatively.
+	 * If it seems our ACKs are not reaching the other side,
+	 * based on receiving a duplicate data segment with new flowlabel
+	 * (suggesting the sender suffered an RTO), and we are not already
+	 * repathing due to our own RTO, then rehash the socket to repath our
+	 * packets.
 	 */
-	if (TCP_SKB_CB(skb)->seq == tcp_sk(sk)->duplicate_sack[0].start_seq &&
+#if IS_ENABLED(CONFIG_IPV6)
+	if (inet_csk(sk)->icsk_ca_state != TCP_CA_Loss &&
+	    skb->protocol == htons(ETH_P_IPV6) &&
+	    (tcp_sk(sk)->inet_conn.icsk_ack.lrcv_flowlabel !=
+	     ntohl(ip6_flowlabel(ipv6_hdr(skb)))) &&
 	    sk_rethink_txhash(sk))
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPDUPLICATEDATAREHASH);
+
+	/* Save last flowlabel after a spurious retrans. */
+	tcp_save_lrcv_flowlabel(sk, skb);
+#endif
 }
 
 static void tcp_send_dupack(struct sock *sk, const struct sk_buff *skb)
@@ -4826,6 +4936,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
 	u32 seq, end_seq;
 	bool fragstolen;
 
+	tcp_save_lrcv_flowlabel(sk, skb);
 	tcp_ecn_check_ce(sk, skb);
 
 	if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) {
@@ -5571,6 +5682,14 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
 	    tcp_in_quickack_mode(sk) ||
 	    /* Protocol state mandates a one-time immediate ACK */
 	    inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOW) {
+		/* If we are running from __release_sock() in user context,
+		 * Defer the ack until tcp_release_cb().
+		 */
+		if (sock_owned_by_user_nocheck(sk) &&
+		    READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_backlog_ack_defer)) {
+			set_bit(TCP_ACK_DEFERRED, &sk->sk_tsq_flags);
+			return;
+		}
 send_now:
 		tcp_send_ack(sk);
 		return;
@@ -6105,6 +6224,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
 
+	tcp_ao_finish_connect(sk, skb);
 	tcp_set_state(sk, TCP_ESTABLISHED);
 	icsk->icsk_ack.lrcvtime = tcp_jiffies32;
 
@@ -6253,7 +6373,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 
 		if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
 		    !between(tp->rx_opt.rcv_tsecr, tp->retrans_stamp,
-			     tcp_time_stamp(tp))) {
+			     tcp_time_stamp_ts(tp))) {
 			NET_INC_STATS(sock_net(sk),
 					LINUX_MIB_PAWSACTIVEREJECTED);
 			goto reset_and_undo;
@@ -6390,6 +6510,16 @@ consume:
 		 * simultaneous connect with crossed SYNs.
 		 * Particularly, it can be connect to self.
 		 */
+#ifdef CONFIG_TCP_AO
+		struct tcp_ao_info *ao;
+
+		ao = rcu_dereference_protected(tp->ao_info,
+					       lockdep_sock_is_held(sk));
+		if (ao) {
+			WRITE_ONCE(ao->risn, th->seq);
+			ao->rcv_sne = 0;
+		}
+#endif
 		tcp_set_state(sk, TCP_SYN_RECV);
 
 		if (tp->rx_opt.saw_tstamp) {
@@ -6464,6 +6594,7 @@ static void tcp_rcv_synrecv_state_fastopen(struct sock *sk)
 		tcp_try_undo_recovery(sk);
 
 	/* Reset rtx states to prevent spurious retransmits_timed_out() */
+	tcp_update_rto_time(tp);
 	tp->retrans_stamp = 0;
 	inet_csk(sk)->icsk_retransmits = 0;
 
@@ -6601,6 +6732,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 					  skb);
 			WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
 		}
+		tcp_ao_established(sk);
 		smp_mb();
 		tcp_set_state(sk, TCP_ESTABLISHED);
 		sk->sk_state_change(sk);
@@ -6977,6 +7109,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	struct flowi fl;
 	u8 syncookies;
 
+#ifdef CONFIG_TCP_AO
+	const struct tcp_ao_hdr *aoh;
+#endif
+
 	syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
 
 	/* TW buckets are converted to open requests without
@@ -7001,6 +7137,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	req->syncookie = want_cookie;
 	tcp_rsk(req)->af_specific = af_ops;
 	tcp_rsk(req)->ts_off = 0;
+	tcp_rsk(req)->req_usec_ts = false;
 #if IS_ENABLED(CONFIG_MPTCP)
 	tcp_rsk(req)->is_mptcp = 0;
 #endif
@@ -7028,9 +7165,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 	if (!dst)
 		goto drop_and_free;
 
-	if (tmp_opt.tstamp_ok)
+	if (tmp_opt.tstamp_ok) {
+		tcp_rsk(req)->req_usec_ts = dst_tcp_usec_ts(dst);
 		tcp_rsk(req)->ts_off = af_ops->init_ts_off(net, skb);
-
+	}
 	if (!want_cookie && !isn) {
 		int max_syn_backlog = READ_ONCE(net->ipv4.sysctl_max_syn_backlog);
 
@@ -7062,6 +7200,18 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 			inet_rsk(req)->ecn_ok = 0;
 	}
 
+#ifdef CONFIG_TCP_AO
+	if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+		goto drop_and_release; /* Invalid TCP options */
+	if (aoh) {
+		tcp_rsk(req)->used_tcp_ao = true;
+		tcp_rsk(req)->ao_rcv_next = aoh->keyid;
+		tcp_rsk(req)->ao_keyid = aoh->rnext_keyid;
+
+	} else {
+		tcp_rsk(req)->used_tcp_ao = false;
+	}
+#endif
 	tcp_rsk(req)->snt_isn = isn;
 	tcp_rsk(req)->txhash = net_tx_rndhash();
 	tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c7ffab37a3..0c50c5a32b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -296,6 +296,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		rt = NULL;
 		goto failure;
 	}
+	tp->tcp_usec_ts = dst_tcp_usec_ts(&rt->dst);
 	/* OK, now commit destination to socket.  */
 	sk->sk_gso_type = SKB_GSO_TCPV4;
 	sk_setup_caps(sk, &rt->dst);
@@ -493,6 +494,8 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 		return -ENOENT;
 	}
 	if (sk->sk_state == TCP_TIME_WAIT) {
+		/* To increase the counter of ignored icmps for TCP-AO */
+		tcp_ao_ignore_icmp(sk, AF_INET, type, code);
 		inet_twsk_put(inet_twsk(sk));
 		return 0;
 	}
@@ -506,6 +509,11 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 		return 0;
 	}
 
+	if (tcp_ao_ignore_icmp(sk, AF_INET, type, code)) {
+		sock_put(sk);
+		return 0;
+	}
+
 	bh_lock_sock(sk);
 	/* If too many ICMPs get dropped on busy
 	 * servers this needs to be solved differently.
@@ -656,6 +664,52 @@ void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(tcp_v4_send_check);
 
+#define REPLY_OPTIONS_LEN      (MAX_TCP_OPTION_SPACE / sizeof(__be32))
+
+static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb,
+				 const struct tcp_ao_hdr *aoh,
+				 struct ip_reply_arg *arg, struct tcphdr *reply,
+				 __be32 reply_options[REPLY_OPTIONS_LEN])
+{
+#ifdef CONFIG_TCP_AO
+	int sdif = tcp_v4_sdif(skb);
+	int dif = inet_iif(skb);
+	int l3index = sdif ? dif : 0;
+	bool allocated_traffic_key;
+	struct tcp_ao_key *key;
+	char *traffic_key;
+	bool drop = true;
+	u32 ao_sne = 0;
+	u8 keyid;
+
+	rcu_read_lock();
+	if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, ntohl(reply->seq),
+				 &key, &traffic_key, &allocated_traffic_key,
+				 &keyid, &ao_sne))
+		goto out;
+
+	reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) |
+				 (aoh->rnext_keyid << 8) | keyid);
+	arg->iov[0].iov_len += tcp_ao_len_aligned(key);
+	reply->doff = arg->iov[0].iov_len / 4;
+
+	if (tcp_ao_hash_hdr(AF_INET, (char *)&reply_options[1],
+			    key, traffic_key,
+			    (union tcp_ao_addr *)&ip_hdr(skb)->saddr,
+			    (union tcp_ao_addr *)&ip_hdr(skb)->daddr,
+			    reply, ao_sne))
+		goto out;
+	drop = false;
+out:
+	rcu_read_unlock();
+	if (allocated_traffic_key)
+		kfree(traffic_key);
+	return drop;
+#else
+	return true;
+#endif
+}
+
 /*
  *	This routine will send an RST to the other tcp.
  *
@@ -669,26 +723,21 @@ EXPORT_SYMBOL(tcp_v4_send_check);
  *	Exception: precedence violation. We do not implement it in any case.
  */
 
-#ifdef CONFIG_TCP_MD5SIG
-#define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED
-#else
-#define OPTION_BYTES sizeof(__be32)
-#endif
-
 static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct {
 		struct tcphdr th;
-		__be32 opt[OPTION_BYTES / sizeof(__be32)];
+		__be32 opt[REPLY_OPTIONS_LEN];
 	} rep;
+	const __u8 *md5_hash_location = NULL;
+	const struct tcp_ao_hdr *aoh;
 	struct ip_reply_arg arg;
 #ifdef CONFIG_TCP_MD5SIG
 	struct tcp_md5sig_key *key = NULL;
-	const __u8 *hash_location = NULL;
 	unsigned char newhash[16];
-	int genhash;
 	struct sock *sk1 = NULL;
+	int genhash;
 #endif
 	u64 transmit_time = 0;
 	struct sock *ctl_sk;
@@ -725,9 +774,16 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	arg.iov[0].iov_len  = sizeof(rep.th);
 
 	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
+
+	/* Invalid TCP option size or twice included auth */
+	if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, &aoh))
+		return;
+
+	if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, &arg, &rep.th, rep.opt))
+		return;
+
 #ifdef CONFIG_TCP_MD5SIG
 	rcu_read_lock();
-	hash_location = tcp_parse_md5sig_option(th);
 	if (sk && sk_fullsock(sk)) {
 		const union tcp_md5_addr *addr;
 		int l3index;
@@ -738,7 +794,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 		l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
 		addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
 		key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
-	} else if (hash_location) {
+	} else if (md5_hash_location) {
 		const union tcp_md5_addr *addr;
 		int sdif = tcp_v4_sdif(skb);
 		int dif = inet_iif(skb);
@@ -770,7 +826,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 
 
 		genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
-		if (genhash || memcmp(hash_location, newhash, 16) != 0)
+		if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
 			goto out;
 
 	}
@@ -828,7 +884,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
 				   inet_twsk(sk)->tw_mark : sk->sk_mark;
 		ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?
-				   inet_twsk(sk)->tw_priority : sk->sk_priority;
+				   inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority);
 		transmit_time = tcp_transmit_time(sk);
 		xfrm_sk_clone_policy(ctl_sk, sk);
 		txhash = (sk->sk_state == TCP_TIME_WAIT) ?
@@ -862,17 +918,13 @@ out:
 static void tcp_v4_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,
+			    struct tcp_key *key,
 			    int reply_flags, u8 tos, u32 txhash)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct {
 		struct tcphdr th;
-		__be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
-#ifdef CONFIG_TCP_MD5SIG
-			   + (TCPOLEN_MD5SIG_ALIGNED >> 2)
-#endif
-			];
+		__be32 opt[(MAX_TCP_OPTION_SPACE  >> 2)];
 	} rep;
 	struct net *net = sock_net(sk);
 	struct ip_reply_arg arg;
@@ -903,7 +955,7 @@ static void tcp_v4_send_ack(const struct sock *sk,
 	rep.th.window  = htons(win);
 
 #ifdef CONFIG_TCP_MD5SIG
-	if (key) {
+	if (tcp_key_is_md5(key)) {
 		int offset = (tsecr) ? 3 : 0;
 
 		rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
@@ -914,10 +966,28 @@ static void tcp_v4_send_ack(const struct sock *sk,
 		rep.th.doff = arg.iov[0].iov_len/4;
 
 		tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
-				    key, ip_hdr(skb)->saddr,
+				    key->md5_key, ip_hdr(skb)->saddr,
 				    ip_hdr(skb)->daddr, &rep.th);
 	}
 #endif
+#ifdef CONFIG_TCP_AO
+	if (tcp_key_is_ao(key)) {
+		int offset = (tsecr) ? 3 : 0;
+
+		rep.opt[offset++] = htonl((TCPOPT_AO << 24) |
+					  (tcp_ao_len(key->ao_key) << 16) |
+					  (key->ao_key->sndid << 8) |
+					  key->rcv_next);
+		arg.iov[0].iov_len += tcp_ao_len_aligned(key->ao_key);
+		rep.th.doff = arg.iov[0].iov_len / 4;
+
+		tcp_ao_hash_hdr(AF_INET, (char *)&rep.opt[offset],
+				key->ao_key, key->traffic_key,
+				(union tcp_ao_addr *)&ip_hdr(skb)->saddr,
+				(union tcp_ao_addr *)&ip_hdr(skb)->daddr,
+				&rep.th, key->sne);
+	}
+#endif
 	arg.flags = reply_flags;
 	arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
 				      ip_hdr(skb)->saddr, /* XXX */
@@ -950,18 +1020,53 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 {
 	struct inet_timewait_sock *tw = inet_twsk(sk);
 	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+	struct tcp_key key = {};
+#ifdef CONFIG_TCP_AO
+	struct tcp_ao_info *ao_info;
+
+	if (static_branch_unlikely(&tcp_ao_needed.key)) {
+		/* FIXME: the segment to-be-acked is not verified yet */
+		ao_info = rcu_dereference(tcptw->ao_info);
+		if (ao_info) {
+			const struct tcp_ao_hdr *aoh;
+
+			if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) {
+				inet_twsk_put(tw);
+				return;
+			}
+
+			if (aoh)
+				key.ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+		}
+	}
+	if (key.ao_key) {
+		struct tcp_ao_key *rnext_key;
+
+		key.traffic_key = snd_other_key(key.ao_key);
+		key.sne = READ_ONCE(ao_info->snd_sne);
+		rnext_key = READ_ONCE(ao_info->rnext_key);
+		key.rcv_next = rnext_key->rcvid;
+		key.type = TCP_KEY_AO;
+#else
+	if (0) {
+#endif
+#ifdef CONFIG_TCP_MD5SIG
+	} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
+		key.md5_key = tcp_twsk_md5_key(tcptw);
+		if (key.md5_key)
+			key.type = TCP_KEY_MD5;
+#endif
+	}
 
 	tcp_v4_send_ack(sk, skb,
 			tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
-			tcp_time_stamp_raw() + tcptw->tw_ts_offset,
+			tcp_tw_tsval(tcptw),
 			tcptw->tw_ts_recent,
-			tw->tw_bound_dev_if,
-			tcp_twsk_md5_key(tcptw),
+			tw->tw_bound_dev_if, &key,
 			tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
 			tw->tw_tos,
-			tw->tw_txhash
-			);
+			tw->tw_txhash);
 
 	inet_twsk_put(tw);
 }
@@ -969,8 +1074,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 				  struct request_sock *req)
 {
-	const union tcp_md5_addr *addr;
-	int l3index;
+	struct tcp_key key = {};
 
 	/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 	 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
@@ -978,23 +1082,77 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 	u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
 					     tcp_sk(sk)->snd_nxt;
 
+#ifdef CONFIG_TCP_AO
+	if (static_branch_unlikely(&tcp_ao_needed.key) &&
+	    tcp_rsk_used_ao(req)) {
+		const union tcp_md5_addr *addr;
+		const struct tcp_ao_hdr *aoh;
+		int l3index;
+
+		/* Invalid TCP option size or twice included auth */
+		if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+			return;
+		if (!aoh)
+			return;
+
+		addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+		l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
+		key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET,
+					      aoh->rnext_keyid, -1);
+		if (unlikely(!key.ao_key)) {
+			/* Send ACK with any matching MKT for the peer */
+			key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET, -1, -1);
+			/* Matching key disappeared (user removed the key?)
+			 * let the handshake timeout.
+			 */
+			if (!key.ao_key) {
+				net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n",
+						     addr,
+						     ntohs(tcp_hdr(skb)->source),
+						     &ip_hdr(skb)->daddr,
+						     ntohs(tcp_hdr(skb)->dest));
+				return;
+			}
+		}
+		key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
+		if (!key.traffic_key)
+			return;
+
+		key.type = TCP_KEY_AO;
+		key.rcv_next = aoh->keyid;
+		tcp_v4_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
+#else
+	if (0) {
+#endif
+#ifdef CONFIG_TCP_MD5SIG
+	} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
+		const union tcp_md5_addr *addr;
+		int l3index;
+
+		addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+		l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
+		key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
+		if (key.md5_key)
+			key.type = TCP_KEY_MD5;
+#endif
+	}
+
 	/* RFC 7323 2.3
 	 * The window field (SEG.WND) of every outgoing segment, with the
 	 * exception of <SYN> segments, MUST be right-shifted by
 	 * Rcv.Wind.Shift bits:
 	 */
-	addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
-	l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
 	tcp_v4_send_ack(sk, skb, seq,
 			tcp_rsk(req)->rcv_nxt,
 			req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
-			tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
+			tcp_rsk_tsval(tcp_rsk(req)),
 			READ_ONCE(req->ts_recent),
-			0,
-			tcp_md5_do_lookup(sk, l3index, addr, AF_INET),
+			0, &key,
 			inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
 			ip_hdr(skb)->tos,
 			READ_ONCE(tcp_rsk(req)->txhash));
+	if (tcp_key_is_ao(&key))
+		kfree(key.traffic_key);
 }
 
 /*
@@ -1024,10 +1182,11 @@ static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
 	if (skb) {
 		__tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr);
 
-		tos = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
-				(tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
-				(inet_sk(sk)->tos & INET_ECN_MASK) :
-				inet_sk(sk)->tos;
+		tos = READ_ONCE(inet_sk(sk)->tos);
+
+		if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
+			tos = (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
+			      (tos & INET_ECN_MASK);
 
 		if (!INET_ECN_is_capable(tos) &&
 		    tcp_bpf_ca_needs_ecn((struct sock *)req))
@@ -1080,7 +1239,7 @@ static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *
 /* Find the Key structure for an address.  */
 struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
 					   const union tcp_md5_addr *addr,
-					   int family)
+					   int family, bool any_l3index)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;
@@ -1099,7 +1258,8 @@ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
 				 lockdep_sock_is_held(sk)) {
 		if (key->family != family)
 			continue;
-		if (key->flags & TCP_MD5SIG_FLAG_IFINDEX && key->l3index != l3index)
+		if (!any_l3index && key->flags & TCP_MD5SIG_FLAG_IFINDEX &&
+		    key->l3index != l3index)
 			continue;
 		if (family == AF_INET) {
 			mask = inet_make_mask(key->prefixlen);
@@ -1219,10 +1379,6 @@ static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO);
 	if (!key)
 		return -ENOMEM;
-	if (!tcp_alloc_md5sig_pool()) {
-		sock_kfree_s(sk, key, sizeof(*key));
-		return -ENOMEM;
-	}
 
 	memcpy(key->key, newkey, newkeylen);
 	key->keylen = newkeylen;
@@ -1244,15 +1400,21 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	struct tcp_sock *tp = tcp_sk(sk);
 
 	if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
-		if (tcp_md5sig_info_add(sk, GFP_KERNEL))
+		if (tcp_md5_alloc_sigpool())
 			return -ENOMEM;
 
+		if (tcp_md5sig_info_add(sk, GFP_KERNEL)) {
+			tcp_md5_release_sigpool();
+			return -ENOMEM;
+		}
+
 		if (!static_branch_inc(&tcp_md5_needed.key)) {
 			struct tcp_md5sig_info *md5sig;
 
 			md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk));
 			rcu_assign_pointer(tp->md5sig_info, NULL);
 			kfree_rcu(md5sig, rcu);
+			tcp_md5_release_sigpool();
 			return -EUSERS;
 		}
 	}
@@ -1269,8 +1431,12 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
 	struct tcp_sock *tp = tcp_sk(sk);
 
 	if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
-		if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC)))
+		tcp_md5_add_sigpool();
+
+		if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC))) {
+			tcp_md5_release_sigpool();
 			return -ENOMEM;
+		}
 
 		if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) {
 			struct tcp_md5sig_info *md5sig;
@@ -1279,6 +1445,7 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
 			net_warn_ratelimited("Too many TCP-MD5 keys in the system\n");
 			rcu_assign_pointer(tp->md5sig_info, NULL);
 			kfree_rcu(md5sig, rcu);
+			tcp_md5_release_sigpool();
 			return -EUSERS;
 		}
 	}
@@ -1304,7 +1471,7 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family,
 }
 EXPORT_SYMBOL(tcp_md5_do_del);
 
-static void tcp_clear_md5_list(struct sock *sk)
+void tcp_clear_md5_list(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_key *key;
@@ -1328,6 +1495,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 	const union tcp_md5_addr *addr;
 	u8 prefixlen = 32;
 	int l3index = 0;
+	bool l3flag;
 	u8 flags;
 
 	if (optlen < sizeof(cmd))
@@ -1340,6 +1508,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 		return -EINVAL;
 
 	flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+	l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
 
 	if (optname == TCP_MD5SIG_EXT &&
 	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
@@ -1374,11 +1543,17 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
 	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 		return -EINVAL;
 
+	/* Don't allow keys for peers that have a matching TCP-AO key.
+	 * See the comment in tcp_ao_add_cmd()
+	 */
+	if (tcp_ao_required(sk, addr, AF_INET, l3flag ? l3index : -1, false))
+		return -EKEYREJECTED;
+
 	return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
 			      cmd.tcpm_key, cmd.tcpm_keylen);
 }
 
-static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
+static int tcp_v4_md5_hash_headers(struct tcp_sigpool *hp,
 				   __be32 daddr, __be32 saddr,
 				   const struct tcphdr *th, int nbytes)
 {
@@ -1398,38 +1573,35 @@ static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
 	_th->check = 0;
 
 	sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
-	ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+	ahash_request_set_crypt(hp->req, &sg, NULL,
 				sizeof(*bp) + sizeof(*th));
-	return crypto_ahash_update(hp->md5_req);
+	return crypto_ahash_update(hp->req);
 }
 
 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 			       __be32 daddr, __be32 saddr, const struct tcphdr *th)
 {
-	struct tcp_md5sig_pool *hp;
-	struct ahash_request *req;
+	struct tcp_sigpool hp;
 
-	hp = tcp_get_md5sig_pool();
-	if (!hp)
-		goto clear_hash_noput;
-	req = hp->md5_req;
+	if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+		goto clear_hash_nostart;
 
-	if (crypto_ahash_init(req))
+	if (crypto_ahash_init(hp.req))
 		goto clear_hash;
-	if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+	if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
 		goto clear_hash;
-	if (tcp_md5_hash_key(hp, key))
+	if (tcp_md5_hash_key(&hp, key))
 		goto clear_hash;
-	ahash_request_set_crypt(req, NULL, md5_hash, 0);
-	if (crypto_ahash_final(req))
+	ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+	if (crypto_ahash_final(hp.req))
 		goto clear_hash;
 
-	tcp_put_md5sig_pool();
+	tcp_sigpool_end(&hp);
 	return 0;
 
 clear_hash:
-	tcp_put_md5sig_pool();
-clear_hash_noput:
+	tcp_sigpool_end(&hp);
+clear_hash_nostart:
 	memset(md5_hash, 0, 16);
 	return 1;
 }
@@ -1438,9 +1610,8 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
 			const struct sock *sk,
 			const struct sk_buff *skb)
 {
-	struct tcp_md5sig_pool *hp;
-	struct ahash_request *req;
 	const struct tcphdr *th = tcp_hdr(skb);
+	struct tcp_sigpool hp;
 	__be32 saddr, daddr;
 
 	if (sk) { /* valid for establish/request sockets */
@@ -1452,30 +1623,28 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
 		daddr = iph->daddr;
 	}
 
-	hp = tcp_get_md5sig_pool();
-	if (!hp)
-		goto clear_hash_noput;
-	req = hp->md5_req;
+	if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+		goto clear_hash_nostart;
 
-	if (crypto_ahash_init(req))
+	if (crypto_ahash_init(hp.req))
 		goto clear_hash;
 
-	if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+	if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
 		goto clear_hash;
-	if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+	if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
 		goto clear_hash;
-	if (tcp_md5_hash_key(hp, key))
+	if (tcp_md5_hash_key(&hp, key))
 		goto clear_hash;
-	ahash_request_set_crypt(req, NULL, md5_hash, 0);
-	if (crypto_ahash_final(req))
+	ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+	if (crypto_ahash_final(hp.req))
 		goto clear_hash;
 
-	tcp_put_md5sig_pool();
+	tcp_sigpool_end(&hp);
 	return 0;
 
 clear_hash:
-	tcp_put_md5sig_pool();
-clear_hash_noput:
+	tcp_sigpool_end(&hp);
+clear_hash_nostart:
 	memset(md5_hash, 0, 16);
 	return 1;
 }
@@ -1524,6 +1693,11 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
 	.req_md5_lookup	=	tcp_v4_md5_lookup,
 	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
 #endif
+#ifdef CONFIG_TCP_AO
+	.ao_lookup	=	tcp_v4_ao_lookup_rsk,
+	.ao_calc_key	=	tcp_v4_ao_calc_key_rsk,
+	.ao_synack_hash	=	tcp_v4_ao_synack_hash,
+#endif
 #ifdef CONFIG_SYN_COOKIES
 	.cookie_init_seq =	cookie_v4_init_sequence,
 #endif
@@ -1625,12 +1799,16 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 	/* Copy over the MD5 key from the original socket */
 	addr = (union tcp_md5_addr *)&newinet->inet_daddr;
 	key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
-	if (key) {
+	if (key && !tcp_rsk_used_ao(req)) {
 		if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key))
 			goto put_and_exit;
 		sk_gso_disable(newsk);
 	}
 #endif
+#ifdef CONFIG_TCP_AO
+	if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET))
+		goto put_and_exit; /* OOM, release back memory */
+#endif
 
 	if (__inet_inherit_port(sk, newsk) < 0)
 		goto put_and_exit;
@@ -2041,9 +2219,9 @@ process:
 		if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
 			drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		else
-			drop_reason = tcp_inbound_md5_hash(sk, skb,
-						   &iph->saddr, &iph->daddr,
-						   AF_INET, dif, sdif);
+			drop_reason = tcp_inbound_hash(sk, req, skb,
+						       &iph->saddr, &iph->daddr,
+						       AF_INET, dif, sdif);
 		if (unlikely(drop_reason)) {
 			sk_drops_add(sk, skb);
 			reqsk_put(req);
@@ -2120,8 +2298,8 @@ process:
 		goto discard_and_relse;
 	}
 
-	drop_reason = tcp_inbound_md5_hash(sk, skb, &iph->saddr,
-					   &iph->daddr, AF_INET, dif, sdif);
+	drop_reason = tcp_inbound_hash(sk, NULL, skb, &iph->saddr, &iph->daddr,
+				       AF_INET, dif, sdif);
 	if (drop_reason)
 		goto discard_and_relse;
 
@@ -2268,11 +2446,19 @@ const struct inet_connection_sock_af_ops ipv4_specific = {
 };
 EXPORT_SYMBOL(ipv4_specific);
 
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
+#ifdef CONFIG_TCP_MD5SIG
 	.md5_lookup		= tcp_v4_md5_lookup,
 	.calc_md5_hash		= tcp_v4_md5_hash_skb,
 	.md5_parse		= tcp_v4_parse_md5_keys,
+#endif
+#ifdef CONFIG_TCP_AO
+	.ao_lookup		= tcp_v4_ao_lookup,
+	.calc_ao_hash		= tcp_v4_ao_hash_skb,
+	.ao_parse		= tcp_v4_parse_ao,
+	.ao_calc_key_sk		= tcp_v4_ao_calc_key_sk,
+#endif
 };
 #endif
 
@@ -2287,13 +2473,25 @@ static int tcp_v4_init_sock(struct sock *sk)
 
 	icsk->icsk_af_ops = &ipv4_specific;
 
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 	tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific;
 #endif
 
 	return 0;
 }
 
+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5sig_info_free_rcu(struct rcu_head *head)
+{
+	struct tcp_md5sig_info *md5sig;
+
+	md5sig = container_of(head, struct tcp_md5sig_info, rcu);
+	kfree(md5sig);
+	static_branch_slow_dec_deferred(&tcp_md5_needed);
+	tcp_md5_release_sigpool();
+}
+#endif
+
 void tcp_v4_destroy_sock(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -2318,12 +2516,15 @@ void tcp_v4_destroy_sock(struct sock *sk)
 #ifdef CONFIG_TCP_MD5SIG
 	/* Clean up the MD5 key list, if any */
 	if (tp->md5sig_info) {
+		struct tcp_md5sig_info *md5sig;
+
+		md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
 		tcp_clear_md5_list(sk);
-		kfree_rcu(rcu_dereference_protected(tp->md5sig_info, 1), rcu);
-		tp->md5sig_info = NULL;
-		static_branch_slow_dec_deferred(&tcp_md5_needed);
+		call_rcu(&md5sig->rcu, tcp_md5sig_info_free_rcu);
+		rcu_assign_pointer(tp->md5sig_info, NULL);
 	}
 #endif
+	tcp_ao_destroy_sock(sk, false);
 
 	/* Clean up a referenced TCP bind bucket. */
 	if (inet_csk(sk)->icsk_bind_hash)
@@ -3264,6 +3465,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC;
 	net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC;
 	net->ipv4.sysctl_tcp_comp_sack_nr = 44;
+	net->ipv4.sysctl_tcp_backlog_ack_defer = 1;
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
 	net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 0;
 	atomic_set(&net->ipv4.tfo_active_disable_times, 0);
@@ -3287,6 +3489,8 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_syn_linear_timeouts = 4;
 	net->ipv4.sysctl_tcp_shrink_window = 0;
 
+	net->ipv4.sysctl_tcp_pingpong_thresh = 1;
+
 	return 0;
 }
 
diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
index ae36780977..52fe171674 100644
--- a/net/ipv4/tcp_lp.c
+++ b/net/ipv4/tcp_lp.c
@@ -272,7 +272,7 @@ static void tcp_lp_pkts_acked(struct sock *sk, const struct ack_sample *sample)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct lp *lp = inet_csk_ca(sk);
-	u32 now = tcp_time_stamp(tp);
+	u32 now = tcp_time_stamp_ts(tp);
 	u32 delta;
 
 	if (sample->rtt_us > 0)
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 7aca12c59c..c2a9255385 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -898,11 +898,13 @@ static void tcp_metrics_flush_all(struct net *net)
 	unsigned int row;
 
 	for (row = 0; row < max_rows; row++, hb++) {
-		struct tcp_metrics_block __rcu **pp;
+		struct tcp_metrics_block __rcu **pp = &hb->chain;
 		bool match;
 
+		if (!rcu_access_pointer(*pp))
+			continue;
+
 		spin_lock_bh(&tcp_metrics_lock);
-		pp = &hb->chain;
 		for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
 			match = net ? net_eq(tm_net(tm), net) :
 				!refcount_read(&tm_net(tm)->ns.count);
@@ -914,6 +916,7 @@ static void tcp_metrics_flush_all(struct net *net)
 			}
 		}
 		spin_unlock_bh(&tcp_metrics_lock);
+		cond_resched();
 	}
 }
 
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index b98d476f15..9e85f2a0bd 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -51,6 +51,18 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw,
 	return TCP_TW_SUCCESS;
 }
 
+static void twsk_rcv_nxt_update(struct tcp_timewait_sock *tcptw, u32 seq)
+{
+#ifdef CONFIG_TCP_AO
+	struct tcp_ao_info *ao;
+
+	ao = rcu_dereference(tcptw->ao_info);
+	if (unlikely(ao && seq < tcptw->tw_rcv_nxt))
+		WRITE_ONCE(ao->rcv_sne, ao->rcv_sne + 1);
+#endif
+	tcptw->tw_rcv_nxt = seq;
+}
+
 /*
  * * Main purpose of TIME-WAIT state is to close connection gracefully,
  *   when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
@@ -136,7 +148,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
 
 		/* FIN arrived, enter true time-wait state. */
 		tw->tw_substate	  = TCP_TIME_WAIT;
-		tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+		twsk_rcv_nxt_update(tcptw, TCP_SKB_CB(skb)->end_seq);
+
 		if (tmp_opt.saw_tstamp) {
 			tcptw->tw_ts_recent_stamp = ktime_get_seconds();
 			tcptw->tw_ts_recent	  = tmp_opt.rcv_tsval;
@@ -261,10 +274,9 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
 		tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC);
 		if (!tcptw->tw_md5_key)
 			return;
-		if (!tcp_alloc_md5sig_pool())
-			goto out_free;
 		if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key))
 			goto out_free;
+		tcp_md5_add_sigpool();
 	}
 	return;
 out_free:
@@ -280,7 +292,7 @@ out_free:
 void tcp_time_wait(struct sock *sk, int state, int timeo)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
-	const struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
 	struct net *net = sock_net(sk);
 	struct inet_timewait_sock *tw;
 
@@ -292,7 +304,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 
 		tw->tw_transparent	= inet_test_bit(TRANSPARENT, sk);
 		tw->tw_mark		= sk->sk_mark;
-		tw->tw_priority		= sk->sk_priority;
+		tw->tw_priority		= READ_ONCE(sk->sk_priority);
 		tw->tw_rcv_wscale	= tp->rx_opt.rcv_wscale;
 		tcptw->tw_rcv_nxt	= tp->rcv_nxt;
 		tcptw->tw_snd_nxt	= tp->snd_nxt;
@@ -300,6 +312,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 		tcptw->tw_ts_recent	= tp->rx_opt.ts_recent;
 		tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
 		tcptw->tw_ts_offset	= tp->tsoffset;
+		tw->tw_usec_ts		= tp->tcp_usec_ts;
 		tcptw->tw_last_oow_ack_time = 0;
 		tcptw->tw_tx_delay	= tp->tcp_tx_delay;
 		tw->tw_txhash		= sk->sk_txhash;
@@ -316,6 +329,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 #endif
 
 		tcp_time_wait_init(sk, tcptw);
+		tcp_ao_time_wait(tcptw, tp);
 
 		/* Get the TIME_WAIT timeout firing. */
 		if (timeo < rto)
@@ -348,18 +362,29 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 }
 EXPORT_SYMBOL(tcp_time_wait);
 
+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5_twsk_free_rcu(struct rcu_head *head)
+{
+	struct tcp_md5sig_key *key;
+
+	key = container_of(head, struct tcp_md5sig_key, rcu);
+	kfree(key);
+	static_branch_slow_dec_deferred(&tcp_md5_needed);
+	tcp_md5_release_sigpool();
+}
+#endif
+
 void tcp_twsk_destructor(struct sock *sk)
 {
 #ifdef CONFIG_TCP_MD5SIG
 	if (static_branch_unlikely(&tcp_md5_needed.key)) {
 		struct tcp_timewait_sock *twsk = tcp_twsk(sk);
 
-		if (twsk->tw_md5_key) {
-			kfree_rcu(twsk->tw_md5_key, rcu);
-			static_branch_slow_dec_deferred(&tcp_md5_needed);
-		}
+		if (twsk->tw_md5_key)
+			call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu);
 	}
 #endif
+	tcp_ao_destroy_sock(sk, true);
 }
 EXPORT_SYMBOL_GPL(tcp_twsk_destructor);
 
@@ -494,6 +519,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 	const struct tcp_sock *oldtp;
 	struct tcp_sock *newtp;
 	u32 seq;
+#ifdef CONFIG_TCP_AO
+	struct tcp_ao_key *ao_key;
+#endif
 
 	if (!newsk)
 		return NULL;
@@ -554,22 +582,41 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 	newtp->max_window = newtp->snd_wnd;
 
 	if (newtp->rx_opt.tstamp_ok) {
+		newtp->tcp_usec_ts = treq->req_usec_ts;
 		newtp->rx_opt.ts_recent = READ_ONCE(req->ts_recent);
 		newtp->rx_opt.ts_recent_stamp = ktime_get_seconds();
 		newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
 	} else {
+		newtp->tcp_usec_ts = 0;
 		newtp->rx_opt.ts_recent_stamp = 0;
 		newtp->tcp_header_len = sizeof(struct tcphdr);
 	}
 	if (req->num_timeout) {
+		newtp->total_rto = req->num_timeout;
 		newtp->undo_marker = treq->snt_isn;
-		newtp->retrans_stamp = div_u64(treq->snt_synack,
-					       USEC_PER_SEC / TCP_TS_HZ);
+		if (newtp->tcp_usec_ts) {
+			newtp->retrans_stamp = treq->snt_synack;
+			newtp->total_rto_time = (u32)(tcp_clock_us() -
+						      newtp->retrans_stamp) / USEC_PER_MSEC;
+		} else {
+			newtp->retrans_stamp = div_u64(treq->snt_synack,
+						       USEC_PER_SEC / TCP_TS_HZ);
+			newtp->total_rto_time = tcp_clock_ms() -
+						newtp->retrans_stamp;
+		}
+		newtp->total_rto_recoveries = 1;
 	}
 	newtp->tsoffset = treq->ts_off;
 #ifdef CONFIG_TCP_MD5SIG
 	newtp->md5sig_info = NULL;	/*XXX*/
 #endif
+#ifdef CONFIG_TCP_AO
+	newtp->ao_info = NULL;
+	ao_key = treq->af_specific->ao_lookup(sk, req,
+				tcp_rsk(req)->ao_keyid, -1);
+	if (ao_key)
+		newtp->tcp_header_len += tcp_ao_len_aligned(ao_key);
+ #endif
 	if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len)
 		newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;
 	newtp->rx_opt.mss_clamp = req->mss;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index ab3b7b4b44..e3167ad965 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -170,10 +170,10 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
 	tp->lsndtime = now;
 
 	/* If it is a reply for ato after last received
-	 * packet, enter pingpong mode.
+	 * packet, increase pingpong count.
 	 */
 	if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
-		inet_csk_enter_pingpong_mode(sk);
+		inet_csk_inc_pingpong_cnt(sk);
 }
 
 /* Account for an ACK we sent. */
@@ -422,6 +422,7 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp)
 #define OPTION_FAST_OPEN_COOKIE	BIT(8)
 #define OPTION_SMC		BIT(9)
 #define OPTION_MPTCP		BIT(10)
+#define OPTION_AO		BIT(11)
 
 static void smc_options_write(__be32 *ptr, u16 *options)
 {
@@ -600,6 +601,44 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
 }
 #endif
 
+static __be32 *process_tcp_ao_options(struct tcp_sock *tp,
+				      const struct tcp_request_sock *tcprsk,
+				      struct tcp_out_options *opts,
+				      struct tcp_key *key, __be32 *ptr)
+{
+#ifdef CONFIG_TCP_AO
+	u8 maclen = tcp_ao_maclen(key->ao_key);
+
+	if (tcprsk) {
+		u8 aolen = maclen + sizeof(struct tcp_ao_hdr);
+
+		*ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) |
+			       (tcprsk->ao_keyid << 8) |
+			       (tcprsk->ao_rcv_next));
+	} else {
+		struct tcp_ao_key *rnext_key;
+		struct tcp_ao_info *ao_info;
+
+		ao_info = rcu_dereference_check(tp->ao_info,
+			lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
+		rnext_key = READ_ONCE(ao_info->rnext_key);
+		if (WARN_ON_ONCE(!rnext_key))
+			return ptr;
+		*ptr++ = htonl((TCPOPT_AO << 24) |
+			       (tcp_ao_len(key->ao_key) << 16) |
+			       (key->ao_key->sndid << 8) |
+			       (rnext_key->rcvid));
+	}
+	opts->hash_location = (__u8 *)ptr;
+	ptr += maclen / sizeof(*ptr);
+	if (unlikely(maclen % sizeof(*ptr))) {
+		memset(ptr, TCPOPT_NOP, sizeof(*ptr));
+		ptr++;
+	}
+#endif
+	return ptr;
+}
+
 /* Write previously computed TCP options to the packet.
  *
  * Beware: Something in the Internet is very sensitive to the ordering of
@@ -614,19 +653,22 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
  * (but it may well be that other scenarios fail similarly).
  */
 static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
-			      struct tcp_out_options *opts)
+			      const struct tcp_request_sock *tcprsk,
+			      struct tcp_out_options *opts,
+			      struct tcp_key *key)
 {
 	__be32 *ptr = (__be32 *)(th + 1);
 	u16 options = opts->options;	/* mungable copy */
 
-	if (unlikely(OPTION_MD5 & options)) {
+	if (tcp_key_is_md5(key)) {
 		*ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 			       (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 		/* overload cookie hash location */
 		opts->hash_location = (__u8 *)ptr;
 		ptr += 4;
+	} else if (tcp_key_is_ao(key)) {
+		ptr = process_tcp_ao_options(tp, tcprsk, opts, key, ptr);
 	}
-
 	if (unlikely(opts->mss)) {
 		*ptr++ = htonl((TCPOPT_MSS << 24) |
 			       (TCPOLEN_MSS << 16) |
@@ -767,23 +809,25 @@ static void mptcp_set_option_cond(const struct request_sock *req,
  */
 static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 				struct tcp_out_options *opts,
-				struct tcp_md5sig_key **md5)
+				struct tcp_key *key)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	unsigned int remaining = MAX_TCP_OPTION_SPACE;
 	struct tcp_fastopen_request *fastopen = tp->fastopen_req;
+	bool timestamps;
 
-	*md5 = NULL;
-#ifdef CONFIG_TCP_MD5SIG
-	if (static_branch_unlikely(&tcp_md5_needed.key) &&
-	    rcu_access_pointer(tp->md5sig_info)) {
-		*md5 = tp->af_specific->md5_lookup(sk, sk);
-		if (*md5) {
-			opts->options |= OPTION_MD5;
-			remaining -= TCPOLEN_MD5SIG_ALIGNED;
+	/* Better than switch (key.type) as it has static branches */
+	if (tcp_key_is_md5(key)) {
+		timestamps = false;
+		opts->options |= OPTION_MD5;
+		remaining -= TCPOLEN_MD5SIG_ALIGNED;
+	} else {
+		timestamps = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps);
+		if (tcp_key_is_ao(key)) {
+			opts->options |= OPTION_AO;
+			remaining -= tcp_ao_len_aligned(key->ao_key);
 		}
 	}
-#endif
 
 	/* We always get an MSS option.  The option bytes which will be seen in
 	 * normal data packets should timestamps be used, must be in the MSS
@@ -797,9 +841,9 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 	opts->mss = tcp_advertise_mss(sk);
 	remaining -= TCPOLEN_MSS_ALIGNED;
 
-	if (likely(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps) && !*md5)) {
+	if (likely(timestamps)) {
 		opts->options |= OPTION_TS;
-		opts->tsval = tcp_skb_timestamp(skb) + tp->tsoffset;
+		opts->tsval = tcp_skb_timestamp_ts(tp->tcp_usec_ts, skb) + tp->tsoffset;
 		opts->tsecr = tp->rx_opt.ts_recent;
 		remaining -= TCPOLEN_TSTAMP_ALIGNED;
 	}
@@ -850,7 +894,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 				       struct request_sock *req,
 				       unsigned int mss, struct sk_buff *skb,
 				       struct tcp_out_options *opts,
-				       const struct tcp_md5sig_key *md5,
+				       const struct tcp_key *key,
 				       struct tcp_fastopen_cookie *foc,
 				       enum tcp_synack_type synack_type,
 				       struct sk_buff *syn_skb)
@@ -858,8 +902,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 	struct inet_request_sock *ireq = inet_rsk(req);
 	unsigned int remaining = MAX_TCP_OPTION_SPACE;
 
-#ifdef CONFIG_TCP_MD5SIG
-	if (md5) {
+	if (tcp_key_is_md5(key)) {
 		opts->options |= OPTION_MD5;
 		remaining -= TCPOLEN_MD5SIG_ALIGNED;
 
@@ -870,8 +913,11 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 		 */
 		if (synack_type != TCP_SYNACK_COOKIE)
 			ireq->tstamp_ok &= !ireq->sack_ok;
+	} else if (tcp_key_is_ao(key)) {
+		opts->options |= OPTION_AO;
+		remaining -= tcp_ao_len_aligned(key->ao_key);
+		ireq->tstamp_ok &= !ireq->sack_ok;
 	}
-#endif
 
 	/* We always send an MSS option. */
 	opts->mss = mss;
@@ -884,7 +930,8 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 	}
 	if (likely(ireq->tstamp_ok)) {
 		opts->options |= OPTION_TS;
-		opts->tsval = tcp_skb_timestamp(skb) + tcp_rsk(req)->ts_off;
+		opts->tsval = tcp_skb_timestamp_ts(tcp_rsk(req)->req_usec_ts, skb) +
+			      tcp_rsk(req)->ts_off;
 		opts->tsecr = READ_ONCE(req->ts_recent);
 		remaining -= TCPOLEN_TSTAMP_ALIGNED;
 	}
@@ -921,7 +968,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
  */
 static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb,
 					struct tcp_out_options *opts,
-					struct tcp_md5sig_key **md5)
+					struct tcp_key *key)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	unsigned int size = 0;
@@ -929,21 +976,19 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 
 	opts->options = 0;
 
-	*md5 = NULL;
-#ifdef CONFIG_TCP_MD5SIG
-	if (static_branch_unlikely(&tcp_md5_needed.key) &&
-	    rcu_access_pointer(tp->md5sig_info)) {
-		*md5 = tp->af_specific->md5_lookup(sk, sk);
-		if (*md5) {
-			opts->options |= OPTION_MD5;
-			size += TCPOLEN_MD5SIG_ALIGNED;
-		}
+	/* Better than switch (key.type) as it has static branches */
+	if (tcp_key_is_md5(key)) {
+		opts->options |= OPTION_MD5;
+		size += TCPOLEN_MD5SIG_ALIGNED;
+	} else if (tcp_key_is_ao(key)) {
+		opts->options |= OPTION_AO;
+		size += tcp_ao_len_aligned(key->ao_key);
 	}
-#endif
 
 	if (likely(tp->rx_opt.tstamp_ok)) {
 		opts->options |= OPTION_TS;
-		opts->tsval = skb ? tcp_skb_timestamp(skb) + tp->tsoffset : 0;
+		opts->tsval = skb ? tcp_skb_timestamp_ts(tp->tcp_usec_ts, skb) +
+				tp->tsoffset : 0;
 		opts->tsecr = tp->rx_opt.ts_recent;
 		size += TCPOLEN_TSTAMP_ALIGNED;
 	}
@@ -1076,7 +1121,8 @@ static void tcp_tasklet_func(struct tasklet_struct *t)
 #define TCP_DEFERRED_ALL (TCPF_TSQ_DEFERRED |		\
 			  TCPF_WRITE_TIMER_DEFERRED |	\
 			  TCPF_DELACK_TIMER_DEFERRED |	\
-			  TCPF_MTU_REDUCED_DEFERRED)
+			  TCPF_MTU_REDUCED_DEFERRED |	\
+			  TCPF_ACK_DEFERRED)
 /**
  * tcp_release_cb - tcp release_sock() callback
  * @sk: socket
@@ -1100,16 +1146,6 @@ void tcp_release_cb(struct sock *sk)
 		tcp_tsq_write(sk);
 		__sock_put(sk);
 	}
-	/* Here begins the tricky part :
-	 * We are called from release_sock() with :
-	 * 1) BH disabled
-	 * 2) sk_lock.slock spinlock held
-	 * 3) socket owned by us (sk->sk_lock.owned == 1)
-	 *
-	 * But following code is meant to be called from BH handlers,
-	 * so we should keep BH disabled, but early release socket ownership
-	 */
-	sock_release_ownership(sk);
 
 	if (flags & TCPF_WRITE_TIMER_DEFERRED) {
 		tcp_write_timer_handler(sk);
@@ -1123,6 +1159,8 @@ void tcp_release_cb(struct sock *sk)
 		inet_csk(sk)->icsk_af_ops->mtu_reduced(sk);
 		__sock_put(sk);
 	}
+	if ((flags & TCPF_ACK_DEFERRED) && inet_csk_ack_scheduled(sk))
+		tcp_send_ack(sk);
 }
 EXPORT_SYMBOL(tcp_release_cb);
 
@@ -1207,7 +1245,7 @@ static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb,
 	struct tcp_sock *tp = tcp_sk(sk);
 
 	if (sk->sk_pacing_status != SK_PACING_NONE) {
-		unsigned long rate = sk->sk_pacing_rate;
+		unsigned long rate = READ_ONCE(sk->sk_pacing_rate);
 
 		/* Original sch_fq does not pace first 10 MSS
 		 * Note that tp->data_segs_out overflows after 2^32 packets,
@@ -1250,7 +1288,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	struct tcp_out_options opts;
 	unsigned int tcp_options_size, tcp_header_size;
 	struct sk_buff *oskb = NULL;
-	struct tcp_md5sig_key *md5;
+	struct tcp_key key;
 	struct tcphdr *th;
 	u64 prior_wstamp;
 	int err;
@@ -1282,11 +1320,11 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	tcb = TCP_SKB_CB(skb);
 	memset(&opts, 0, sizeof(opts));
 
+	tcp_get_current_key(sk, &key);
 	if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
-		tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
+		tcp_options_size = tcp_syn_options(sk, skb, &opts, &key);
 	} else {
-		tcp_options_size = tcp_established_options(sk, skb, &opts,
-							   &md5);
+		tcp_options_size = tcp_established_options(sk, skb, &opts, &key);
 		/* Force a PSH flag on all (GSO) packets to expedite GRO flush
 		 * at receiver : This slightly improve GRO performance.
 		 * Note that we do not force the PSH flag for non GSO packets,
@@ -1367,16 +1405,25 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 		th->window	= htons(min(tp->rcv_wnd, 65535U));
 	}
 
-	tcp_options_write(th, tp, &opts);
+	tcp_options_write(th, tp, NULL, &opts, &key);
 
+	if (tcp_key_is_md5(&key)) {
 #ifdef CONFIG_TCP_MD5SIG
-	/* Calculate the MD5 hash, as we have all we need now */
-	if (md5) {
+		/* Calculate the MD5 hash, as we have all we need now */
 		sk_gso_disable(sk);
 		tp->af_specific->calc_md5_hash(opts.hash_location,
-					       md5, sk, skb);
-	}
+					       key.md5_key, sk, skb);
 #endif
+	} else if (tcp_key_is_ao(&key)) {
+		int err;
+
+		err = tcp_ao_transmit_skb(sk, skb, key.ao_key, th,
+					  opts.hash_location);
+		if (err) {
+			kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
+			return -ENOMEM;
+		}
+	}
 
 	/* BPF prog is the last one writing header option */
 	bpf_skops_write_hdr_opt(sk, skb, NULL, NULL, 0, &opts);
@@ -1703,14 +1750,6 @@ static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu)
 	 */
 	mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
 
-	/* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
-	if (icsk->icsk_af_ops->net_frag_header_len) {
-		const struct dst_entry *dst = __sk_dst_get(sk);
-
-		if (dst && dst_allfrag(dst))
-			mss_now -= icsk->icsk_af_ops->net_frag_header_len;
-	}
-
 	/* Clamp it (mss_clamp does not include tcp options) */
 	if (mss_now > tp->rx_opt.mss_clamp)
 		mss_now = tp->rx_opt.mss_clamp;
@@ -1738,21 +1777,11 @@ int tcp_mss_to_mtu(struct sock *sk, int mss)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
-	int mtu;
 
-	mtu = mss +
+	return mss +
 	      tp->tcp_header_len +
 	      icsk->icsk_ext_hdr_len +
 	      icsk->icsk_af_ops->net_header_len;
-
-	/* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
-	if (icsk->icsk_af_ops->net_frag_header_len) {
-		const struct dst_entry *dst = __sk_dst_get(sk);
-
-		if (dst && dst_allfrag(dst))
-			mtu += icsk->icsk_af_ops->net_frag_header_len;
-	}
-	return mtu;
 }
 EXPORT_SYMBOL(tcp_mss_to_mtu);
 
@@ -1827,7 +1856,7 @@ unsigned int tcp_current_mss(struct sock *sk)
 	u32 mss_now;
 	unsigned int header_len;
 	struct tcp_out_options opts;
-	struct tcp_md5sig_key *md5;
+	struct tcp_key key;
 
 	mss_now = tp->mss_cache;
 
@@ -1836,8 +1865,8 @@ unsigned int tcp_current_mss(struct sock *sk)
 		if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
 			mss_now = tcp_sync_mss(sk, mtu);
 	}
-
-	header_len = tcp_established_options(sk, NULL, &opts, &md5) +
+	tcp_get_current_key(sk, &key);
+	header_len = tcp_established_options(sk, NULL, &opts, &key) +
 		     sizeof(struct tcphdr);
 	/* The mss_cache is sized based on tp->tcp_header_len, which assumes
 	 * some common options. If this is an odd packet (because we have SACK
@@ -1979,7 +2008,7 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
 	unsigned long bytes;
 	u32 r;
 
-	bytes = sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift);
+	bytes = READ_ONCE(sk->sk_pacing_rate) >> READ_ONCE(sk->sk_pacing_shift);
 
 	r = tcp_min_rtt(tcp_sk(sk)) >> READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log);
 	if (r < BITS_PER_TYPE(sk->sk_gso_max_size))
@@ -2572,7 +2601,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
 
 	limit = max_t(unsigned long,
 		      2 * skb->truesize,
-		      sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift));
+		      READ_ONCE(sk->sk_pacing_rate) >> READ_ONCE(sk->sk_pacing_shift));
 	if (sk->sk_pacing_status == SK_PACING_NONE)
 		limit = min_t(unsigned long, limit,
 			      READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_limit_output_bytes));
@@ -2580,7 +2609,8 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
 
 	if (static_branch_unlikely(&tcp_tx_delay_enabled) &&
 	    tcp_sk(sk)->tcp_tx_delay) {
-		u64 extra_bytes = (u64)sk->sk_pacing_rate * tcp_sk(sk)->tcp_tx_delay;
+		u64 extra_bytes = (u64)READ_ONCE(sk->sk_pacing_rate) *
+				  tcp_sk(sk)->tcp_tx_delay;
 
 		/* TSQ is based on skb truesize sum (sk_wmem_alloc), so we
 		 * approximate our needs assuming an ~100% skb->truesize overhead.
@@ -3391,7 +3421,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
 
 	/* Save stamp of the first (attempted) retransmit. */
 	if (!tp->retrans_stamp)
-		tp->retrans_stamp = tcp_skb_timestamp(skb);
+		tp->retrans_stamp = tcp_skb_timestamp_ts(tp->tcp_usec_ts, skb);
 
 	if (tp->undo_retrans < 0)
 		tp->undo_retrans = 0;
@@ -3639,8 +3669,8 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
 	const struct tcp_sock *tp = tcp_sk(sk);
-	struct tcp_md5sig_key *md5 = NULL;
 	struct tcp_out_options opts;
+	struct tcp_key key = {};
 	struct sk_buff *skb;
 	int tcp_header_size;
 	struct tcphdr *th;
@@ -3690,16 +3720,45 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 			tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb);
 	}
 
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 	rcu_read_lock();
-	md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req));
 #endif
+	if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+		struct tcp_ao_key *ao_key = NULL;
+		u8 keyid = tcp_rsk(req)->ao_keyid;
+
+		ao_key = tcp_sk(sk)->af_specific->ao_lookup(sk, req_to_sk(req),
+							    keyid, -1);
+		/* If there is no matching key - avoid sending anything,
+		 * especially usigned segments. It could try harder and lookup
+		 * for another peer-matching key, but the peer has requested
+		 * ao_keyid (RFC5925 RNextKeyID), so let's keep it simple here.
+		 */
+		if (unlikely(!ao_key)) {
+			rcu_read_unlock();
+			kfree_skb(skb);
+			net_warn_ratelimited("TCP-AO: the keyid %u from SYN packet is not present - not sending SYNACK\n",
+					     keyid);
+			return NULL;
+		}
+		key.ao_key = ao_key;
+		key.type = TCP_KEY_AO;
+#endif
+	} else {
+#ifdef CONFIG_TCP_MD5SIG
+		key.md5_key = tcp_rsk(req)->af_specific->req_md5_lookup(sk,
+					req_to_sk(req));
+		if (key.md5_key)
+			key.type = TCP_KEY_MD5;
+#endif
+	}
 	skb_set_hash(skb, READ_ONCE(tcp_rsk(req)->txhash), PKT_HASH_TYPE_L4);
 	/* bpf program will be interested in the tcp_flags */
 	TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK;
-	tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
-					     foc, synack_type,
-					     syn_skb) + sizeof(*th);
+	tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts,
+					     &key, foc, synack_type, syn_skb)
+					+ sizeof(*th);
 
 	skb_push(skb, tcp_header_size);
 	skb_reset_transport_header(skb);
@@ -3719,15 +3778,24 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 
 	/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
 	th->window = htons(min(req->rsk_rcv_wnd, 65535U));
-	tcp_options_write(th, NULL, &opts);
+	tcp_options_write(th, NULL, tcp_rsk(req), &opts, &key);
 	th->doff = (tcp_header_size >> 2);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
 
-#ifdef CONFIG_TCP_MD5SIG
 	/* Okay, we have all we need - do the md5 hash if needed */
-	if (md5)
+	if (tcp_key_is_md5(&key)) {
+#ifdef CONFIG_TCP_MD5SIG
 		tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location,
-					       md5, req_to_sk(req), skb);
+					key.md5_key, req_to_sk(req), skb);
+#endif
+	} else if (tcp_key_is_ao(&key)) {
+#ifdef CONFIG_TCP_AO
+		tcp_rsk(req)->af_specific->ao_synack_hash(opts.hash_location,
+					key.ao_key, req, skb,
+					opts.hash_location - (u8 *)th, 0);
+#endif
+	}
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 	rcu_read_unlock();
 #endif
 
@@ -3775,6 +3843,8 @@ static void tcp_connect_init(struct sock *sk)
 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_timestamps))
 		tp->tcp_header_len += TCPOLEN_TSTAMP_ALIGNED;
 
+	tcp_ao_connect_init(sk);
+
 	/* If user gave his TCP_MAXSEG, record it to clamp */
 	if (tp->rx_opt.user_mss)
 		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
@@ -3957,6 +4027,53 @@ int tcp_connect(struct sock *sk)
 
 	tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB, 0, NULL);
 
+#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO)
+	/* Has to be checked late, after setting daddr/saddr/ops.
+	 * Return error if the peer has both a md5 and a tcp-ao key
+	 * configured as this is ambiguous.
+	 */
+	if (unlikely(rcu_dereference_protected(tp->md5sig_info,
+					       lockdep_sock_is_held(sk)))) {
+		bool needs_ao = !!tp->af_specific->ao_lookup(sk, sk, -1, -1);
+		bool needs_md5 = !!tp->af_specific->md5_lookup(sk, sk);
+		struct tcp_ao_info *ao_info;
+
+		ao_info = rcu_dereference_check(tp->ao_info,
+						lockdep_sock_is_held(sk));
+		if (ao_info) {
+			/* This is an extra check: tcp_ao_required() in
+			 * tcp_v{4,6}_parse_md5_keys() should prevent adding
+			 * md5 keys on ao_required socket.
+			 */
+			needs_ao |= ao_info->ao_required;
+			WARN_ON_ONCE(ao_info->ao_required && needs_md5);
+		}
+		if (needs_md5 && needs_ao)
+			return -EKEYREJECTED;
+
+		/* If we have a matching md5 key and no matching tcp-ao key
+		 * then free up ao_info if allocated.
+		 */
+		if (needs_md5) {
+			tcp_ao_destroy_sock(sk, false);
+		} else if (needs_ao) {
+			tcp_clear_md5_list(sk);
+			kfree(rcu_replace_pointer(tp->md5sig_info, NULL,
+						  lockdep_sock_is_held(sk)));
+		}
+	}
+#endif
+#ifdef CONFIG_TCP_AO
+	if (unlikely(rcu_dereference_protected(tp->ao_info,
+					       lockdep_sock_is_held(sk)))) {
+		/* Don't allow connecting if ao is configured but no
+		 * matching key is found.
+		 */
+		if (!tp->af_specific->ao_lookup(sk, sk, -1, -1))
+			return -EKEYREJECTED;
+	}
+#endif
+
 	if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
 		return -EHOSTUNREACH; /* Routing failure or similar. */
 
@@ -3973,7 +4090,7 @@ int tcp_connect(struct sock *sk)
 
 	tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
 	tcp_mstamp_refresh(tp);
-	tp->retrans_stamp = tcp_time_stamp(tp);
+	tp->retrans_stamp = tcp_time_stamp_ts(tp);
 	tcp_connect_queue_skb(sk, buff);
 	tcp_ecn_send_syn(sk, buff);
 	tcp_rbtree_insert(&sk->tcp_rtx_queue, buff);
diff --git a/net/ipv4/tcp_sigpool.c b/net/ipv4/tcp_sigpool.c
new file mode 100644
index 0000000000..8512cb09eb
--- /dev/null
+++ b/net/ipv4/tcp_sigpool.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <crypto/hash.h>
+#include <linux/cpu.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/workqueue.h>
+#include <net/tcp.h>
+
+static size_t __scratch_size;
+static DEFINE_PER_CPU(void __rcu *, sigpool_scratch);
+
+struct sigpool_entry {
+	struct crypto_ahash	*hash;
+	const char		*alg;
+	struct kref		kref;
+	uint16_t		needs_key:1,
+				reserved:15;
+};
+
+#define CPOOL_SIZE (PAGE_SIZE / sizeof(struct sigpool_entry))
+static struct sigpool_entry cpool[CPOOL_SIZE];
+static unsigned int cpool_populated;
+static DEFINE_MUTEX(cpool_mutex);
+
+/* Slow-path */
+struct scratches_to_free {
+	struct rcu_head rcu;
+	unsigned int cnt;
+	void *scratches[];
+};
+
+static void free_old_scratches(struct rcu_head *head)
+{
+	struct scratches_to_free *stf;
+
+	stf = container_of(head, struct scratches_to_free, rcu);
+	while (stf->cnt--)
+		kfree(stf->scratches[stf->cnt]);
+	kfree(stf);
+}
+
+/**
+ * sigpool_reserve_scratch - re-allocates scratch buffer, slow-path
+ * @size: request size for the scratch/temp buffer
+ */
+static int sigpool_reserve_scratch(size_t size)
+{
+	struct scratches_to_free *stf;
+	size_t stf_sz = struct_size(stf, scratches, num_possible_cpus());
+	int cpu, err = 0;
+
+	lockdep_assert_held(&cpool_mutex);
+	if (__scratch_size >= size)
+		return 0;
+
+	stf = kmalloc(stf_sz, GFP_KERNEL);
+	if (!stf)
+		return -ENOMEM;
+	stf->cnt = 0;
+
+	size = max(size, __scratch_size);
+	cpus_read_lock();
+	for_each_possible_cpu(cpu) {
+		void *scratch, *old_scratch;
+
+		scratch = kmalloc_node(size, GFP_KERNEL, cpu_to_node(cpu));
+		if (!scratch) {
+			err = -ENOMEM;
+			break;
+		}
+
+		old_scratch = rcu_replace_pointer(per_cpu(sigpool_scratch, cpu),
+					scratch, lockdep_is_held(&cpool_mutex));
+		if (!cpu_online(cpu) || !old_scratch) {
+			kfree(old_scratch);
+			continue;
+		}
+		stf->scratches[stf->cnt++] = old_scratch;
+	}
+	cpus_read_unlock();
+	if (!err)
+		__scratch_size = size;
+
+	call_rcu(&stf->rcu, free_old_scratches);
+	return err;
+}
+
+static void sigpool_scratch_free(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		kfree(rcu_replace_pointer(per_cpu(sigpool_scratch, cpu),
+					  NULL, lockdep_is_held(&cpool_mutex)));
+	__scratch_size = 0;
+}
+
+static int __cpool_try_clone(struct crypto_ahash *hash)
+{
+	struct crypto_ahash *tmp;
+
+	tmp = crypto_clone_ahash(hash);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	crypto_free_ahash(tmp);
+	return 0;
+}
+
+static int __cpool_alloc_ahash(struct sigpool_entry *e, const char *alg)
+{
+	struct crypto_ahash *cpu0_hash;
+	int ret;
+
+	e->alg = kstrdup(alg, GFP_KERNEL);
+	if (!e->alg)
+		return -ENOMEM;
+
+	cpu0_hash = crypto_alloc_ahash(alg, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(cpu0_hash)) {
+		ret = PTR_ERR(cpu0_hash);
+		goto out_free_alg;
+	}
+
+	e->needs_key = crypto_ahash_get_flags(cpu0_hash) & CRYPTO_TFM_NEED_KEY;
+
+	ret = __cpool_try_clone(cpu0_hash);
+	if (ret)
+		goto out_free_cpu0_hash;
+	e->hash = cpu0_hash;
+	kref_init(&e->kref);
+	return 0;
+
+out_free_cpu0_hash:
+	crypto_free_ahash(cpu0_hash);
+out_free_alg:
+	kfree(e->alg);
+	e->alg = NULL;
+	return ret;
+}
+
+/**
+ * tcp_sigpool_alloc_ahash - allocates pool for ahash requests
+ * @alg: name of async hash algorithm
+ * @scratch_size: reserve a tcp_sigpool::scratch buffer of this size
+ */
+int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size)
+{
+	int i, ret;
+
+	/* slow-path */
+	mutex_lock(&cpool_mutex);
+	ret = sigpool_reserve_scratch(scratch_size);
+	if (ret)
+		goto out;
+	for (i = 0; i < cpool_populated; i++) {
+		if (!cpool[i].alg)
+			continue;
+		if (strcmp(cpool[i].alg, alg))
+			continue;
+
+		/* pairs with tcp_sigpool_release() */
+		if (!kref_get_unless_zero(&cpool[i].kref))
+			kref_init(&cpool[i].kref);
+		ret = i;
+		goto out;
+	}
+
+	for (i = 0; i < cpool_populated; i++) {
+		if (!cpool[i].alg)
+			break;
+	}
+	if (i >= CPOOL_SIZE) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	ret = __cpool_alloc_ahash(&cpool[i], alg);
+	if (!ret) {
+		ret = i;
+		if (i == cpool_populated)
+			cpool_populated++;
+	}
+out:
+	mutex_unlock(&cpool_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_alloc_ahash);
+
+static void __cpool_free_entry(struct sigpool_entry *e)
+{
+	crypto_free_ahash(e->hash);
+	kfree(e->alg);
+	memset(e, 0, sizeof(*e));
+}
+
+static void cpool_cleanup_work_cb(struct work_struct *work)
+{
+	bool free_scratch = true;
+	unsigned int i;
+
+	mutex_lock(&cpool_mutex);
+	for (i = 0; i < cpool_populated; i++) {
+		if (kref_read(&cpool[i].kref) > 0) {
+			free_scratch = false;
+			continue;
+		}
+		if (!cpool[i].alg)
+			continue;
+		__cpool_free_entry(&cpool[i]);
+	}
+	if (free_scratch)
+		sigpool_scratch_free();
+	mutex_unlock(&cpool_mutex);
+}
+
+static DECLARE_WORK(cpool_cleanup_work, cpool_cleanup_work_cb);
+static void cpool_schedule_cleanup(struct kref *kref)
+{
+	schedule_work(&cpool_cleanup_work);
+}
+
+/**
+ * tcp_sigpool_release - decreases number of users for a pool. If it was
+ * the last user of the pool, releases any memory that was consumed.
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ */
+void tcp_sigpool_release(unsigned int id)
+{
+	if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg))
+		return;
+
+	/* slow-path */
+	kref_put(&cpool[id].kref, cpool_schedule_cleanup);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_release);
+
+/**
+ * tcp_sigpool_get - increases number of users (refcounter) for a pool
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ */
+void tcp_sigpool_get(unsigned int id)
+{
+	if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg))
+		return;
+	kref_get(&cpool[id].kref);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_get);
+
+int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c) __cond_acquires(RCU_BH)
+{
+	struct crypto_ahash *hash;
+
+	rcu_read_lock_bh();
+	if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg)) {
+		rcu_read_unlock_bh();
+		return -EINVAL;
+	}
+
+	hash = crypto_clone_ahash(cpool[id].hash);
+	if (IS_ERR(hash)) {
+		rcu_read_unlock_bh();
+		return PTR_ERR(hash);
+	}
+
+	c->req = ahash_request_alloc(hash, GFP_ATOMIC);
+	if (!c->req) {
+		crypto_free_ahash(hash);
+		rcu_read_unlock_bh();
+		return -ENOMEM;
+	}
+	ahash_request_set_callback(c->req, 0, NULL, NULL);
+
+	/* Pairs with tcp_sigpool_reserve_scratch(), scratch area is
+	 * valid (allocated) until tcp_sigpool_end().
+	 */
+	c->scratch = rcu_dereference_bh(*this_cpu_ptr(&sigpool_scratch));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_start);
+
+void tcp_sigpool_end(struct tcp_sigpool *c) __releases(RCU_BH)
+{
+	struct crypto_ahash *hash = crypto_ahash_reqtfm(c->req);
+
+	rcu_read_unlock_bh();
+	ahash_request_free(c->req);
+	crypto_free_ahash(hash);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_end);
+
+/**
+ * tcp_sigpool_algo - return algorithm of tcp_sigpool
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ * @buf: buffer to return name of algorithm
+ * @buf_len: size of @buf
+ */
+size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len)
+{
+	if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg))
+		return -EINVAL;
+
+	return strscpy(buf, cpool[id].alg, buf_len);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_algo);
+
+/**
+ * tcp_sigpool_hash_skb_data - hash data in skb with initialized tcp_sigpool
+ * @hp: tcp_sigpool pointer
+ * @skb: buffer to add sign for
+ * @header_len: TCP header length for this segment
+ */
+int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp,
+			      const struct sk_buff *skb,
+			      unsigned int header_len)
+{
+	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
+					   skb_headlen(skb) - header_len : 0;
+	const struct skb_shared_info *shi = skb_shinfo(skb);
+	const struct tcphdr *tp = tcp_hdr(skb);
+	struct ahash_request *req = hp->req;
+	struct sk_buff *frag_iter;
+	struct scatterlist sg;
+	unsigned int i;
+
+	sg_init_table(&sg, 1);
+
+	sg_set_buf(&sg, ((u8 *)tp) + header_len, head_data_len);
+	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
+	if (crypto_ahash_update(req))
+		return 1;
+
+	for (i = 0; i < shi->nr_frags; ++i) {
+		const skb_frag_t *f = &shi->frags[i];
+		unsigned int offset = skb_frag_off(f);
+		struct page *page;
+
+		page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
+		sg_set_page(&sg, page, skb_frag_size(f), offset_in_page(offset));
+		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
+		if (crypto_ahash_update(req))
+			return 1;
+	}
+
+	skb_walk_frags(skb, frag_iter)
+		if (tcp_sigpool_hash_skb_data(hp, frag_iter, 0))
+			return 1;
+
+	return 0;
+}
+EXPORT_SYMBOL(tcp_sigpool_hash_skb_data);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Per-CPU pool of crypto requests");
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 984ab4a042..1f9f6c1c19 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -26,14 +26,18 @@
 static u32 tcp_clamp_rto_to_user_timeout(const struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
-	u32 elapsed, start_ts, user_timeout;
+	const struct tcp_sock *tp = tcp_sk(sk);
+	u32 elapsed, user_timeout;
 	s32 remaining;
 
-	start_ts = tcp_sk(sk)->retrans_stamp;
 	user_timeout = READ_ONCE(icsk->icsk_user_timeout);
 	if (!user_timeout)
 		return icsk->icsk_rto;
-	elapsed = tcp_time_stamp(tcp_sk(sk)) - start_ts;
+
+	elapsed = tcp_time_stamp_ts(tp) - tp->retrans_stamp;
+	if (tp->tcp_usec_ts)
+		elapsed /= USEC_PER_MSEC;
+
 	remaining = user_timeout - elapsed;
 	if (remaining <= 0)
 		return 1; /* user timeout has passed; fire ASAP */
@@ -212,12 +216,13 @@ static bool retransmits_timed_out(struct sock *sk,
 				  unsigned int boundary,
 				  unsigned int timeout)
 {
-	unsigned int start_ts;
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned int start_ts, delta;
 
 	if (!inet_csk(sk)->icsk_retransmits)
 		return false;
 
-	start_ts = tcp_sk(sk)->retrans_stamp;
+	start_ts = tp->retrans_stamp;
 	if (likely(timeout == 0)) {
 		unsigned int rto_base = TCP_RTO_MIN;
 
@@ -226,7 +231,12 @@ static bool retransmits_timed_out(struct sock *sk,
 		timeout = tcp_model_timeout(sk, boundary, rto_base);
 	}
 
-	return (s32)(tcp_time_stamp(tcp_sk(sk)) - start_ts - timeout) >= 0;
+	if (tp->tcp_usec_ts) {
+		/* delta maybe off up to a jiffy due to timer granularity. */
+		delta = tp->tcp_mstamp - start_ts + jiffies_to_usecs(1);
+		return (s32)(delta - timeout * USEC_PER_MSEC) >= 0;
+	}
+	return (s32)(tcp_time_stamp_ts(tp) - start_ts - timeout) >= 0;
 }
 
 /* A write timeout has occurred. Process the after effects. */
@@ -322,7 +332,7 @@ void tcp_delack_timer_handler(struct sock *sk)
 	if (inet_csk_ack_scheduled(sk)) {
 		if (!inet_csk_in_pingpong_mode(sk)) {
 			/* Delayed ACK missed: inflate ATO. */
-			icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1, icsk->icsk_rto);
+			icsk->icsk_ack.ato = min_t(u32, icsk->icsk_ack.ato << 1, icsk->icsk_rto);
 		} else {
 			/* Delayed ACK missed: leave pingpong mode and
 			 * deflate ATO.
@@ -394,7 +404,7 @@ static void tcp_probe_timer(struct sock *sk)
 		if (user_timeout &&
 		    (s32)(tcp_jiffies32 - icsk->icsk_probes_tstamp) >=
 		     msecs_to_jiffies(user_timeout))
-		goto abort;
+			goto abort;
 	}
 	max_probes = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retries2);
 	if (sock_flag(sk, SOCK_DEAD)) {
@@ -415,6 +425,19 @@ abort:		tcp_write_err(sk);
 	}
 }
 
+static void tcp_update_rto_stats(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!icsk->icsk_retransmits) {
+		tp->total_rto_recoveries++;
+		tp->rto_stamp = tcp_time_stamp_ms(tp);
+	}
+	icsk->icsk_retransmits++;
+	tp->total_rto++;
+}
+
 /*
  *	Timer for Fast Open socket to retransmit SYNACK. Note that the
  *	sk here is the child socket, not the parent (listener) socket.
@@ -447,28 +470,26 @@ static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req)
 	 */
 	inet_rtx_syn_ack(sk, req);
 	req->num_timeout++;
-	icsk->icsk_retransmits++;
+	tcp_update_rto_stats(sk);
 	if (!tp->retrans_stamp)
-		tp->retrans_stamp = tcp_time_stamp(tp);
+		tp->retrans_stamp = tcp_time_stamp_ts(tp);
 	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 			  req->timeout << req->num_timeout, TCP_RTO_MAX);
 }
 
 static bool tcp_rtx_probe0_timed_out(const struct sock *sk,
-				     const struct sk_buff *skb)
+				     const struct sk_buff *skb,
+				     u32 rtx_delta)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const int timeout = TCP_RTO_MAX * 2;
-	u32 rcv_delta, rtx_delta;
+	u32 rcv_delta;
 
 	rcv_delta = inet_csk(sk)->icsk_timeout - tp->rcv_tstamp;
 	if (rcv_delta <= timeout)
 		return false;
 
-	rtx_delta = (u32)msecs_to_jiffies(tcp_time_stamp(tp) -
-			(tp->retrans_stamp ?: tcp_skb_timestamp(skb)));
-
-	return rtx_delta > timeout;
+	return msecs_to_jiffies(rtx_delta) > timeout;
 }
 
 /**
@@ -521,7 +542,11 @@ void tcp_retransmit_timer(struct sock *sk)
 		struct inet_sock *inet = inet_sk(sk);
 		u32 rtx_delta;
 
-		rtx_delta = tcp_time_stamp(tp) - (tp->retrans_stamp ?: tcp_skb_timestamp(skb));
+		rtx_delta = tcp_time_stamp_ts(tp) - (tp->retrans_stamp ?: 
+				tcp_skb_timestamp_ts(tp->tcp_usec_ts, skb));
+		if (tp->tcp_usec_ts)
+			rtx_delta /= USEC_PER_MSEC;
+
 		if (sk->sk_family == AF_INET) {
 			net_dbg_ratelimited("Probing zero-window on %pI4:%u/%u, seq=%u:%u, recv %ums ago, lasting %ums\n",
 				&inet->inet_daddr, ntohs(inet->inet_dport),
@@ -538,7 +563,7 @@ void tcp_retransmit_timer(struct sock *sk)
 				rtx_delta);
 		}
 #endif
-		if (tcp_rtx_probe0_timed_out(sk, skb)) {
+		if (tcp_rtx_probe0_timed_out(sk, skb, rtx_delta)) {
 			tcp_write_err(sk);
 			goto out;
 		}
@@ -575,7 +600,7 @@ void tcp_retransmit_timer(struct sock *sk)
 
 	tcp_enter_loss(sk);
 
-	icsk->icsk_retransmits++;
+	tcp_update_rto_stats(sk);
 	if (tcp_retransmit_skb(sk, tcp_rtx_queue_head(sk), 1) > 0) {
 		/* Retransmission failed because of local congestion,
 		 * Let senders fight for local resources conservatively.
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7be4ddc80d..e474b20190 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -750,7 +750,7 @@ int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
 	case ICMP_DEST_UNREACH:
 		if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
 			ipv4_sk_update_pmtu(skb, sk, info);
-			if (inet->pmtudisc != IP_PMTUDISC_DONT) {
+			if (READ_ONCE(inet->pmtudisc) != IP_PMTUDISC_DONT) {
 				err = EMSGSIZE;
 				harderr = 1;
 				break;
@@ -1055,6 +1055,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
 	struct sk_buff *skb;
 	struct ip_options_data opt_copy;
+	int uc_index;
 
 	if (len > 0xFFFF)
 		return -EMSGSIZE;
@@ -1175,25 +1176,26 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	if (scope == RT_SCOPE_LINK)
 		connected = 0;
 
+	uc_index = READ_ONCE(inet->uc_index);
 	if (ipv4_is_multicast(daddr)) {
 		if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
-			ipc.oif = inet->mc_index;
+			ipc.oif = READ_ONCE(inet->mc_index);
 		if (!saddr)
-			saddr = inet->mc_addr;
+			saddr = READ_ONCE(inet->mc_addr);
 		connected = 0;
 	} else if (!ipc.oif) {
-		ipc.oif = inet->uc_index;
-	} else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
+		ipc.oif = uc_index;
+	} else if (ipv4_is_lbcast(daddr) && uc_index) {
 		/* oif is set, packet is to local broadcast and
 		 * uc_index is set. oif is most likely set
 		 * by sk_bound_dev_if. If uc_index != oif check if the
 		 * oif is an L3 master and uc_index is an L3 slave.
 		 * If so, we want to allow the send using the uc_index.
 		 */
-		if (ipc.oif != inet->uc_index &&
+		if (ipc.oif != uc_index &&
 		    ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
-							      inet->uc_index)) {
-			ipc.oif = inet->uc_index;
+							      uc_index)) {
+			ipc.oif = uc_index;
 		}
 	}
 
@@ -1587,12 +1589,7 @@ int udp_init_sock(struct sock *sk)
 
 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
 {
-	if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
-		bool slow = lock_sock_fast(sk);
-
-		sk_peek_offset_bwd(sk, len);
-		unlock_sock_fast(sk, slow);
-	}
+	sk_peek_offset_bwd(sk, len);
 
 	if (!skb_unref(skb))
 		return;
@@ -2167,7 +2164,7 @@ static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 
 	udp_csum_pull_header(skb);
 
-	ipv4_pktinfo_prepare(sk, skb);
+	ipv4_pktinfo_prepare(sk, skb, true);
 	return __udp_queue_rcv_skb(sk, skb);
 
 csum_error:
@@ -2628,6 +2625,19 @@ void udp_destroy_sock(struct sock *sk)
 	}
 }
 
+static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family,
+				       struct sock *sk)
+{
+#ifdef CONFIG_XFRM
+	if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) {
+		if (family == AF_INET)
+			WRITE_ONCE(udp_sk(sk)->gro_receive, xfrm4_gro_udp_encap_rcv);
+		else if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
+			WRITE_ONCE(udp_sk(sk)->gro_receive, ipv6_stub->xfrm6_gro_udp_encap_rcv);
+	}
+#endif
+}
+
 /*
  *	Socket option code for UDP
  */
@@ -2677,6 +2687,8 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		case 0:
 #ifdef CONFIG_XFRM
 		case UDP_ENCAP_ESPINUDP:
+			set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk);
+			fallthrough;
 		case UDP_ENCAP_ESPINUDP_NON_IKE:
 #if IS_ENABLED(CONFIG_IPV6)
 			if (sk->sk_family == AF_INET6)
@@ -2719,6 +2731,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 			udp_tunnel_encap_enable(sk);
 		udp_assign_bit(GRO_ENABLED, sk, valbool);
 		udp_assign_bit(ACCEPT_L4, sk, valbool);
+		set_xfrm_gro_udp_encap_rcv(up->encap_type, sk->sk_family, sk);
 		break;
 
 	/*
diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index de3f2d31f5..dc41a22ee8 100644
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -296,5 +296,6 @@ static void __exit udp_diag_exit(void)
 module_init(udp_diag_init);
 module_exit(udp_diag_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("UDP socket monitoring via SOCK_DIAG");
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
index 1e7e4aecdc..a87defb2b1 100644
--- a/net/ipv4/udp_tunnel_core.c
+++ b/net/ipv4/udp_tunnel_core.c
@@ -204,4 +204,53 @@ struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
 }
 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
 
+struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
+				     struct net_device *dev,
+				     struct net *net, int oif,
+				     __be32 *saddr,
+				     const struct ip_tunnel_key *key,
+				     __be16 sport, __be16 dport, u8 tos,
+				     struct dst_cache *dst_cache)
+{
+	struct rtable *rt = NULL;
+	struct flowi4 fl4;
+
+#ifdef CONFIG_DST_CACHE
+	if (dst_cache) {
+		rt = dst_cache_get_ip4(dst_cache, saddr);
+		if (rt)
+			return rt;
+	}
+#endif
+
+	memset(&fl4, 0, sizeof(fl4));
+	fl4.flowi4_mark = skb->mark;
+	fl4.flowi4_proto = IPPROTO_UDP;
+	fl4.flowi4_oif = oif;
+	fl4.daddr = key->u.ipv4.dst;
+	fl4.saddr = key->u.ipv4.src;
+	fl4.fl4_dport = dport;
+	fl4.fl4_sport = sport;
+	fl4.flowi4_tos = RT_TOS(tos);
+	fl4.flowi4_flags = key->flow_flags;
+
+	rt = ip_route_output_key(net, &fl4);
+	if (IS_ERR(rt)) {
+		netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
+		return ERR_PTR(-ENETUNREACH);
+	}
+	if (rt->dst.dev == dev) { /* is this necessary? */
+		netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
+		ip_rt_put(rt);
+		return ERR_PTR(-ELOOP);
+	}
+#ifdef CONFIG_DST_CACHE
+	if (dst_cache)
+		dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
+#endif
+	*saddr = fl4.saddr;
+	return rt;
+}
+EXPORT_SYMBOL_GPL(udp_tunnel_dst_lookup);
+
 MODULE_LICENSE("GPL");
diff --git a/net/ipv4/udp_tunnel_nic.c b/net/ipv4/udp_tunnel_nic.c
index 0292197497..b6d2d16189 100644
--- a/net/ipv4/udp_tunnel_nic.c
+++ b/net/ipv4/udp_tunnel_nic.c
@@ -47,7 +47,7 @@ struct udp_tunnel_nic {
 
 	unsigned int n_tables;
 	unsigned long missed;
-	struct udp_tunnel_nic_table_entry **entries;
+	struct udp_tunnel_nic_table_entry *entries[] __counted_by(n_tables);
 };
 
 /* We ensure all work structs are done using driver state, but not the code.
@@ -725,16 +725,12 @@ udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
 	struct udp_tunnel_nic *utn;
 	unsigned int i;
 
-	utn = kzalloc(sizeof(*utn), GFP_KERNEL);
+	utn = kzalloc(struct_size(utn, entries, n_tables), GFP_KERNEL);
 	if (!utn)
 		return NULL;
 	utn->n_tables = n_tables;
 	INIT_WORK(&utn->work, udp_tunnel_nic_device_sync_work);
 
-	utn->entries = kmalloc_array(n_tables, sizeof(void *), GFP_KERNEL);
-	if (!utn->entries)
-		goto err_free_utn;
-
 	for (i = 0; i < n_tables; i++) {
 		utn->entries[i] = kcalloc(info->tables[i].n_entries,
 					  sizeof(*utn->entries[i]), GFP_KERNEL);
@@ -747,8 +743,6 @@ udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
 err_free_prev_entries:
 	while (i--)
 		kfree(utn->entries[i]);
-	kfree(utn->entries);
-err_free_utn:
 	kfree(utn);
 	return NULL;
 }
@@ -759,7 +753,6 @@ static void udp_tunnel_nic_free(struct udp_tunnel_nic *utn)
 
 	for (i = 0; i < utn->n_tables; i++)
 		kfree(utn->entries[i]);
-	kfree(utn->entries);
 	kfree(utn);
 }
 
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 183f6dc372..c54676998e 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -17,6 +17,8 @@
 #include <linux/netfilter_ipv4.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
+#include <net/protocol.h>
+#include <net/gro.h>
 
 static int xfrm4_rcv_encap_finish2(struct net *net, struct sock *sk,
 				   struct sk_buff *skb)
@@ -72,14 +74,7 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
 	return 0;
 }
 
-/* If it's a keepalive packet, then just eat it.
- * If it's an encapsulated packet, then pass it to the
- * IPsec xfrm input.
- * Returns 0 if skb passed to xfrm or was dropped.
- * Returns >0 if skb should be passed to UDP.
- * Returns <0 if skb should be resubmitted (-ret is protocol)
- */
-int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+static int __xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull)
 {
 	struct udp_sock *up = udp_sk(sk);
 	struct udphdr *uh;
@@ -110,7 +105,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	case UDP_ENCAP_ESPINUDP:
 		/* Check if this is a keepalive packet.  If so, eat it. */
 		if (len == 1 && udpdata[0] == 0xff) {
-			goto drop;
+			return -EINVAL;
 		} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
 			/* ESP Packet without Non-ESP header */
 			len = sizeof(struct udphdr);
@@ -121,7 +116,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	case UDP_ENCAP_ESPINUDP_NON_IKE:
 		/* Check if this is a keepalive packet.  If so, eat it. */
 		if (len == 1 && udpdata[0] == 0xff) {
-			goto drop;
+			return -EINVAL;
 		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
 			   udpdata32[0] == 0 && udpdata32[1] == 0) {
 
@@ -139,7 +134,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	 * protocol to ESP, and then call into the transform receiver.
 	 */
 	if (skb_unclone(skb, GFP_ATOMIC))
-		goto drop;
+		return -EINVAL;
 
 	/* Now we can update and verify the packet length... */
 	iph = ip_hdr(skb);
@@ -147,25 +142,89 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	iph->tot_len = htons(ntohs(iph->tot_len) - len);
 	if (skb->len < iphlen + len) {
 		/* packet is too small!?! */
-		goto drop;
+		return -EINVAL;
 	}
 
 	/* pull the data buffer up to the ESP header and set the
 	 * transport header to point to ESP.  Keep UDP on the stack
 	 * for later.
 	 */
-	__skb_pull(skb, len);
-	skb_reset_transport_header(skb);
+	if (pull) {
+		__skb_pull(skb, len);
+		skb_reset_transport_header(skb);
+	} else {
+		skb_set_transport_header(skb, len);
+	}
 
 	/* process ESP */
-	return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
-
-drop:
-	kfree_skb(skb);
 	return 0;
 }
+
+/* If it's a keepalive packet, then just eat it.
+ * If it's an encapsulated packet, then pass it to the
+ * IPsec xfrm input.
+ * Returns 0 if skb passed to xfrm or was dropped.
+ * Returns >0 if skb should be passed to UDP.
+ * Returns <0 if skb should be resubmitted (-ret is protocol)
+ */
+int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	int ret;
+
+	ret = __xfrm4_udp_encap_rcv(sk, skb, true);
+	if (!ret)
+		return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0,
+				       udp_sk(sk)->encap_type);
+
+	if (ret < 0) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	return ret;
+}
 EXPORT_SYMBOL(xfrm4_udp_encap_rcv);
 
+struct sk_buff *xfrm4_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
+					struct sk_buff *skb)
+{
+	int offset = skb_gro_offset(skb);
+	const struct net_offload *ops;
+	struct sk_buff *pp = NULL;
+	int ret;
+
+	offset = offset - sizeof(struct udphdr);
+
+	if (!pskb_pull(skb, offset))
+		return NULL;
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_offloads[IPPROTO_ESP]);
+	if (!ops || !ops->callbacks.gro_receive)
+		goto out;
+
+	ret = __xfrm4_udp_encap_rcv(sk, skb, false);
+	if (ret)
+		goto out;
+
+	skb_push(skb, offset);
+	NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
+
+	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	rcu_read_unlock();
+
+	return pp;
+
+out:
+	rcu_read_unlock();
+	skb_push(skb, offset);
+	NAPI_GRO_CB(skb)->same_flow = 0;
+	NAPI_GRO_CB(skb)->flush = 1;
+
+	return NULL;
+}
+EXPORT_SYMBOL(xfrm4_gro_udp_encap_rcv);
+
 int xfrm4_rcv(struct sk_buff *skb)
 {
 	return xfrm4_rcv_spi(skb, ip_hdr(skb)->protocol, 0);