Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp->data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot & felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...

40 files changed, 631 insertions, 536 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 4db0325f6e1a..2d0c05ca9c6f 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -293,7 +293,7 @@ static int arp_constructor(struct neighbour *neigh)
 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
 {
 	dst_link_failure(skb);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_FAILED);
 }
 
 /* Create and send an arp packet. */
@@ -1116,13 +1116,18 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev)
 	return err;
 }
 
-static int arp_invalidate(struct net_device *dev, __be32 ip)
+int arp_invalidate(struct net_device *dev, __be32 ip, bool force)
 {
 	struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
 	int err = -ENXIO;
 	struct neigh_table *tbl = &arp_tbl;
 
 	if (neigh) {
+		if ((neigh->nud_state & NUD_VALID) && !force) {
+			neigh_release(neigh);
+			return 0;
+		}
+
 		if (neigh->nud_state & ~NUD_NOARP)
 			err = neigh_update(neigh, NULL, NUD_FAILED,
 					   NEIGH_UPDATE_F_OVERRIDE|
@@ -1169,7 +1174,7 @@ static int arp_req_delete(struct net *net, struct arpreq *r,
 		if (!dev)
 			return -EINVAL;
 	}
-	return arp_invalidate(dev, ip);
+	return arp_invalidate(dev, ip, true);
 }
 
 /*
diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
index de610cb83694..f79ab942f03b 100644
--- a/net/ipv4/bpf_tcp_ca.c
+++ b/net/ipv4/bpf_tcp_ca.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2019 Facebook  */
 
+#include <linux/init.h>
 #include <linux/types.h>
 #include <linux/bpf_verifier.h>
 #include <linux/bpf.h>
@@ -95,12 +96,14 @@ static int bpf_tcp_ca_btf_struct_access(struct bpf_verifier_log *log,
 					const struct btf *btf,
 					const struct btf_type *t, int off,
 					int size, enum bpf_access_type atype,
-					u32 *next_btf_id)
+					u32 *next_btf_id,
+					enum bpf_type_flag *flag)
 {
 	size_t end;
 
 	if (atype == BPF_READ)
-		return btf_struct_access(log, btf, t, off, size, atype, next_btf_id);
+		return btf_struct_access(log, btf, t, off, size, atype, next_btf_id,
+					 flag);
 
 	if (t != tcp_sock_type) {
 		bpf_log(log, "only read is supported\n");
@@ -212,26 +215,23 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id,
 	}
 }
 
-BTF_SET_START(bpf_tcp_ca_kfunc_ids)
+BTF_SET_START(bpf_tcp_ca_check_kfunc_ids)
 BTF_ID(func, tcp_reno_ssthresh)
 BTF_ID(func, tcp_reno_cong_avoid)
 BTF_ID(func, tcp_reno_undo_cwnd)
 BTF_ID(func, tcp_slow_start)
 BTF_ID(func, tcp_cong_avoid_ai)
-BTF_SET_END(bpf_tcp_ca_kfunc_ids)
+BTF_SET_END(bpf_tcp_ca_check_kfunc_ids)
 
-static bool bpf_tcp_ca_check_kfunc_call(u32 kfunc_btf_id, struct module *owner)
-{
-	if (btf_id_set_contains(&bpf_tcp_ca_kfunc_ids, kfunc_btf_id))
-		return true;
-	return bpf_check_mod_kfunc_call(&bpf_tcp_ca_kfunc_list, kfunc_btf_id, owner);
-}
+static const struct btf_kfunc_id_set bpf_tcp_ca_kfunc_set = {
+	.owner     = THIS_MODULE,
+	.check_set = &bpf_tcp_ca_check_kfunc_ids,
+};
 
 static const struct bpf_verifier_ops bpf_tcp_ca_verifier_ops = {
 	.get_func_proto		= bpf_tcp_ca_get_func_proto,
 	.is_valid_access	= bpf_tcp_ca_is_valid_access,
 	.btf_struct_access	= bpf_tcp_ca_btf_struct_access,
-	.check_kfunc_call	= bpf_tcp_ca_check_kfunc_call,
 };
 
 static int bpf_tcp_ca_init_member(const struct btf_type *t,
@@ -300,3 +300,9 @@ struct bpf_struct_ops bpf_tcp_congestion_ops = {
 	.init = bpf_tcp_ca_init,
 	.name = "tcp_congestion_ops",
 };
+
+static int __init bpf_tcp_ca_kfunc_init(void)
+{
+	return register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_tcp_ca_kfunc_set);
+}
+late_initcall(bpf_tcp_ca_kfunc_init);
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index fba2bffd65f7..53a6b14dc50a 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -104,6 +104,7 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
 	[IFA_FLAGS]		= { .type = NLA_U32 },
 	[IFA_RT_PRIORITY]	= { .type = NLA_U32 },
 	[IFA_TARGET_NETNSID]	= { .type = NLA_S32 },
+	[IFA_PROTO]		= { .type = NLA_U8 },
 };
 
 struct inet_fill_args {
@@ -889,6 +890,9 @@ static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh,
 	if (tb[IFA_RT_PRIORITY])
 		ifa->ifa_rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]);
 
+	if (tb[IFA_PROTO])
+		ifa->ifa_proto = nla_get_u8(tb[IFA_PROTO]);
+
 	if (tb[IFA_CACHEINFO]) {
 		struct ifa_cacheinfo *ci;
 
@@ -1625,6 +1629,7 @@ static size_t inet_nlmsg_size(void)
 	       + nla_total_size(4) /* IFA_BROADCAST */
 	       + nla_total_size(IFNAMSIZ) /* IFA_LABEL */
 	       + nla_total_size(4)  /* IFA_FLAGS */
+	       + nla_total_size(1)  /* IFA_PROTO */
 	       + nla_total_size(4)  /* IFA_RT_PRIORITY */
 	       + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */
 }
@@ -1699,6 +1704,8 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
 	     nla_put_in_addr(skb, IFA_BROADCAST, ifa->ifa_broadcast)) ||
 	    (ifa->ifa_label[0] &&
 	     nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) ||
+	    (ifa->ifa_proto &&
+	     nla_put_u8(skb, IFA_PROTO, ifa->ifa_proto)) ||
 	    nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) ||
 	    (ifa->ifa_rt_priority &&
 	     nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) ||
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 85117b45216d..af8209f912ab 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -32,6 +32,7 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 
+#include <net/inet_dscp.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/route.h>
@@ -290,7 +291,7 @@ __be32 fib_compute_spec_dst(struct sk_buff *skb)
 		bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
 		struct flowi4 fl4 = {
 			.flowi4_iif = LOOPBACK_IFINDEX,
-			.flowi4_oif = l3mdev_master_ifindex_rcu(dev),
+			.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev),
 			.daddr = ip_hdr(skb)->saddr,
 			.flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK,
 			.flowi4_scope = scope,
@@ -352,9 +353,8 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 	bool dev_match;
 
 	fl4.flowi4_oif = 0;
-	fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
-	if (!fl4.flowi4_iif)
-		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
+	fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev);
+	fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 	fl4.daddr = src;
 	fl4.saddr = dst;
 	fl4.flowi4_tos = tos;
@@ -738,8 +738,16 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 	memset(cfg, 0, sizeof(*cfg));
 
 	rtm = nlmsg_data(nlh);
+
+	if (!inet_validate_dscp(rtm->rtm_tos)) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid dsfield (tos): ECN bits must be 0");
+		err = -EINVAL;
+		goto errout;
+	}
+	cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos);
+
 	cfg->fc_dst_len = rtm->rtm_dst_len;
-	cfg->fc_tos = rtm->rtm_tos;
 	cfg->fc_table = rtm->rtm_table;
 	cfg->fc_protocol = rtm->rtm_protocol;
 	cfg->fc_scope = rtm->rtm_scope;
@@ -1115,9 +1123,11 @@ void fib_add_ifaddr(struct in_ifaddr *ifa)
 		return;
 
 	/* Add broadcast address, if it is explicitly assigned. */
-	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
+	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) {
 		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
 			  prim, 0);
+		arp_invalidate(dev, ifa->ifa_broadcast, false);
+	}
 
 	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
@@ -1131,6 +1141,7 @@ void fib_add_ifaddr(struct in_ifaddr *ifa)
 		if (ifa->ifa_prefixlen < 31) {
 			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 				  32, prim, 0);
+			arp_invalidate(dev, prefix | ~mask, false);
 		}
 	}
 }
@@ -1550,7 +1561,7 @@ static void ip_fib_net_exit(struct net *net)
 {
 	int i;
 
-	rtnl_lock();
+	ASSERT_RTNL();
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
 	RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
@@ -1575,7 +1586,7 @@ static void ip_fib_net_exit(struct net *net)
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	fib4_rules_exit(net);
 #endif
-	rtnl_unlock();
+
 	kfree(net->ipv4.fib_table_hash);
 	fib4_notifier_exit(net);
 }
@@ -1602,7 +1613,9 @@ out:
 out_proc:
 	nl_fib_lookup_exit(net);
 out_nlfl:
+	rtnl_lock();
 	ip_fib_net_exit(net);
+	rtnl_unlock();
 	goto out;
 }
 
@@ -1610,12 +1623,23 @@ static void __net_exit fib_net_exit(struct net *net)
 {
 	fib_proc_exit(net);
 	nl_fib_lookup_exit(net);
-	ip_fib_net_exit(net);
+}
+
+static void __net_exit fib_net_exit_batch(struct list_head *net_list)
+{
+	struct net *net;
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list)
+		ip_fib_net_exit(net);
+
+	rtnl_unlock();
 }
 
 static struct pernet_operations fib_net_ops = {
 	.init = fib_net_init,
 	.exit = fib_net_exit,
+	.exit_batch = fib_net_exit_batch,
 };
 
 void __init ip_fib_init(void)
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index 78e40ea42e58..f9b9e26c32c1 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -4,13 +4,14 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
+#include <net/inet_dscp.h>
 #include <net/ip_fib.h>
 #include <net/nexthop.h>
 
 struct fib_alias {
 	struct hlist_node	fa_list;
 	struct fib_info		*fa_info;
-	u8			fa_tos;
+	dscp_t			fa_dscp;
 	u8			fa_type;
 	u8			fa_state;
 	u8			fa_slen;
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index e0b6c8b6de57..001fea394bde 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -23,6 +23,7 @@
 #include <linux/list.h>
 #include <linux/rcupdate.h>
 #include <linux/export.h>
+#include <net/inet_dscp.h>
 #include <net/ip.h>
 #include <net/route.h>
 #include <net/tcp.h>
@@ -35,7 +36,7 @@ struct fib4_rule {
 	struct fib_rule		common;
 	u8			dst_len;
 	u8			src_len;
-	u8			tos;
+	dscp_t			dscp;
 	__be32			src;
 	__be32			srcmask;
 	__be32			dst;
@@ -49,7 +50,7 @@ static bool fib4_rule_matchall(const struct fib_rule *rule)
 {
 	struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
 
-	if (r->dst_len || r->src_len || r->tos)
+	if (r->dst_len || r->src_len || r->dscp)
 		return false;
 	return fib_rule_matchall(rule);
 }
@@ -185,7 +186,7 @@ INDIRECT_CALLABLE_SCOPE int fib4_rule_match(struct fib_rule *rule,
 	    ((daddr ^ r->dst) & r->dstmask))
 		return 0;
 
-	if (r->tos && (r->tos != fl4->flowi4_tos))
+	if (r->dscp && r->dscp != inet_dsfield_to_dscp(fl4->flowi4_tos))
 		return 0;
 
 	if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto))
@@ -225,10 +226,17 @@ static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 	int err = -EINVAL;
 	struct fib4_rule *rule4 = (struct fib4_rule *) rule;
 
+	if (!inet_validate_dscp(frh->tos)) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid dsfield (tos): ECN bits must be 0");
+		goto errout;
+	}
+	/* IPv4 currently doesn't handle high order DSCP bits correctly */
 	if (frh->tos & ~IPTOS_TOS_MASK) {
 		NL_SET_ERR_MSG(extack, "Invalid tos");
 		goto errout;
 	}
+	rule4->dscp = inet_dsfield_to_dscp(frh->tos);
 
 	/* split local/main if they are not already split */
 	err = fib_unmerge(net);
@@ -270,7 +278,6 @@ static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 	rule4->srcmask = inet_make_mask(rule4->src_len);
 	rule4->dst_len = frh->dst_len;
 	rule4->dstmask = inet_make_mask(rule4->dst_len);
-	rule4->tos = frh->tos;
 
 	net->ipv4.fib_has_custom_rules = true;
 
@@ -313,7 +320,7 @@ static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
 	if (frh->dst_len && (rule4->dst_len != frh->dst_len))
 		return 0;
 
-	if (frh->tos && (rule4->tos != frh->tos))
+	if (frh->tos && inet_dscp_to_dsfield(rule4->dscp) != frh->tos)
 		return 0;
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
@@ -337,7 +344,7 @@ static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 
 	frh->dst_len = rule4->dst_len;
 	frh->src_len = rule4->src_len;
-	frh->tos = rule4->tos;
+	frh->tos = inet_dscp_to_dsfield(rule4->dscp);
 
 	if ((rule4->dst_len &&
 	     nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 2dd375f7407b..cc8e84ef2ae4 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -32,6 +32,7 @@
 #include <linux/hash.h>
 
 #include <net/arp.h>
+#include <net/inet_dscp.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/route.h>
@@ -523,7 +524,7 @@ void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
 	fri.tb_id = tb_id;
 	fri.dst = key;
 	fri.dst_len = dst_len;
-	fri.tos = fa->fa_tos;
+	fri.tos = inet_dscp_to_dsfield(fa->fa_dscp);
 	fri.type = fa->fa_type;
 	fri.offload = READ_ONCE(fa->offload);
 	fri.trap = READ_ONCE(fa->trap);
@@ -1257,34 +1258,13 @@ fib_info_laddrhash_bucket(const struct net *net, __be32 val)
 	return &fib_info_laddrhash[slot];
 }
 
-static struct hlist_head *fib_info_hash_alloc(int bytes)
-{
-	if (bytes <= PAGE_SIZE)
-		return kzalloc(bytes, GFP_KERNEL);
-	else
-		return (struct hlist_head *)
-			__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					 get_order(bytes));
-}
-
-static void fib_info_hash_free(struct hlist_head *hash, int bytes)
-{
-	if (!hash)
-		return;
-
-	if (bytes <= PAGE_SIZE)
-		kfree(hash);
-	else
-		free_pages((unsigned long) hash, get_order(bytes));
-}
-
 static void fib_info_hash_move(struct hlist_head *new_info_hash,
 			       struct hlist_head *new_laddrhash,
 			       unsigned int new_size)
 {
 	struct hlist_head *old_info_hash, *old_laddrhash;
 	unsigned int old_size = fib_info_hash_size;
-	unsigned int i, bytes;
+	unsigned int i;
 
 	spin_lock_bh(&fib_info_lock);
 	old_info_hash = fib_info_hash;
@@ -1325,9 +1305,8 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
 
 	spin_unlock_bh(&fib_info_lock);
 
-	bytes = old_size * sizeof(struct hlist_head *);
-	fib_info_hash_free(old_info_hash, bytes);
-	fib_info_hash_free(old_laddrhash, bytes);
+	kvfree(old_info_hash);
+	kvfree(old_laddrhash);
 }
 
 __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
@@ -1444,19 +1423,19 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		unsigned int new_size = fib_info_hash_size << 1;
 		struct hlist_head *new_info_hash;
 		struct hlist_head *new_laddrhash;
-		unsigned int bytes;
+		size_t bytes;
 
 		if (!new_size)
 			new_size = 16;
-		bytes = new_size * sizeof(struct hlist_head *);
-		new_info_hash = fib_info_hash_alloc(bytes);
-		new_laddrhash = fib_info_hash_alloc(bytes);
+		bytes = (size_t)new_size * sizeof(struct hlist_head *);
+		new_info_hash = kvzalloc(bytes, GFP_KERNEL);
+		new_laddrhash = kvzalloc(bytes, GFP_KERNEL);
 		if (!new_info_hash || !new_laddrhash) {
-			fib_info_hash_free(new_info_hash, bytes);
-			fib_info_hash_free(new_laddrhash, bytes);
-		} else
+			kvfree(new_info_hash);
+			kvfree(new_laddrhash);
+		} else {
 			fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
-
+		}
 		if (!fib_info_hash_size)
 			goto failure;
 	}
@@ -2061,7 +2040,7 @@ static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
 	int order = -1, last_idx = -1;
 	struct fib_alias *fa, *fa1 = NULL;
 	u32 last_prio = res->fi->fib_priority;
-	u8 last_tos = 0;
+	dscp_t last_dscp = 0;
 
 	hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
 		struct fib_info *next_fi = fa->fa_info;
@@ -2069,19 +2048,20 @@ static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
 
 		if (fa->fa_slen != slen)
 			continue;
-		if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+		if (fa->fa_dscp &&
+		    fa->fa_dscp != inet_dsfield_to_dscp(flp->flowi4_tos))
 			continue;
 		if (fa->tb_id != tb->tb_id)
 			continue;
 		if (next_fi->fib_priority > last_prio &&
-		    fa->fa_tos == last_tos) {
-			if (last_tos)
+		    fa->fa_dscp == last_dscp) {
+			if (last_dscp)
 				continue;
 			break;
 		}
 		if (next_fi->fib_flags & RTNH_F_DEAD)
 			continue;
-		last_tos = fa->fa_tos;
+		last_dscp = fa->fa_dscp;
 		last_prio = next_fi->fib_priority;
 
 		if (next_fi->fib_scope != res->scope ||
@@ -2254,7 +2234,7 @@ void fib_select_multipath(struct fib_result *res, int hash)
 void fib_select_path(struct net *net, struct fib_result *res,
 		     struct flowi4 *fl4, const struct sk_buff *skb)
 {
-	if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF))
+	if (fl4->flowi4_oif)
 		goto check_saddr;
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index f7f74d5c14da..fb0e49c36c2e 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -61,6 +61,7 @@
 #include <linux/vmalloc.h>
 #include <linux/notifier.h>
 #include <net/net_namespace.h>
+#include <net/inet_dscp.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/route.h>
@@ -81,7 +82,7 @@ static int call_fib_entry_notifier(struct notifier_block *nb,
 		.dst = dst,
 		.dst_len = dst_len,
 		.fi = fa->fa_info,
-		.tos = fa->fa_tos,
+		.tos = inet_dscp_to_dsfield(fa->fa_dscp),
 		.type = fa->fa_type,
 		.tb_id = fa->tb_id,
 	};
@@ -98,7 +99,7 @@ static int call_fib_entry_notifiers(struct net *net,
 		.dst = dst,
 		.dst_len = dst_len,
 		.fi = fa->fa_info,
-		.tos = fa->fa_tos,
+		.tos = inet_dscp_to_dsfield(fa->fa_dscp),
 		.type = fa->fa_type,
 		.tb_id = fa->tb_id,
 	};
@@ -973,13 +974,13 @@ static struct key_vector *fib_find_node(struct trie *t,
 	return n;
 }
 
-/* Return the first fib alias matching TOS with
+/* Return the first fib alias matching DSCP with
  * priority less than or equal to PRIO.
  * If 'find_first' is set, return the first matching
- * fib alias, regardless of TOS and priority.
+ * fib alias, regardless of DSCP and priority.
  */
 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
-					u8 tos, u32 prio, u32 tb_id,
+					dscp_t dscp, u32 prio, u32 tb_id,
 					bool find_first)
 {
 	struct fib_alias *fa;
@@ -988,6 +989,10 @@ static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
 		return NULL;
 
 	hlist_for_each_entry(fa, fah, fa_list) {
+		/* Avoid Sparse warning when using dscp_t in inequalities */
+		u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp);
+		u8 __dscp = inet_dscp_to_dsfield(dscp);
+
 		if (fa->fa_slen < slen)
 			continue;
 		if (fa->fa_slen != slen)
@@ -998,9 +1003,9 @@ static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
 			break;
 		if (find_first)
 			return fa;
-		if (fa->fa_tos > tos)
+		if (__fa_dscp > __dscp)
 			continue;
-		if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
+		if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp)
 			return fa;
 	}
 
@@ -1027,8 +1032,8 @@ fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri)
 
 	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
 		if (fa->fa_slen == slen && fa->tb_id == fri->tb_id &&
-		    fa->fa_tos == fri->tos && fa->fa_info == fri->fi &&
-		    fa->fa_type == fri->type)
+		    fa->fa_dscp == inet_dsfield_to_dscp(fri->tos) &&
+		    fa->fa_info == fri->fi && fa->fa_type == fri->type)
 			return fa;
 	}
 
@@ -1214,7 +1219,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 	struct fib_info *fi;
 	u8 plen = cfg->fc_dst_len;
 	u8 slen = KEYLENGTH - plen;
-	u8 tos = cfg->fc_tos;
+	dscp_t dscp;
 	u32 key;
 	int err;
 
@@ -1231,12 +1236,13 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 		goto err;
 	}
 
+	dscp = cfg->fc_dscp;
 	l = fib_find_node(t, &tp, key);
-	fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
+	fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority,
 				tb->tb_id, false) : NULL;
 
 	/* Now fa, if non-NULL, points to the first fib alias
-	 * with the same keys [prefix,tos,priority], if such key already
+	 * with the same keys [prefix,dscp,priority], if such key already
 	 * exists or to the node before which we will insert new one.
 	 *
 	 * If fa is NULL, we will need to allocate a new one and
@@ -1244,7 +1250,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 	 * of the new alias.
 	 */
 
-	if (fa && fa->fa_tos == tos &&
+	if (fa && fa->fa_dscp == dscp &&
 	    fa->fa_info->fib_priority == fi->fib_priority) {
 		struct fib_alias *fa_first, *fa_match;
 
@@ -1264,7 +1270,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 		hlist_for_each_entry_from(fa, fa_list) {
 			if ((fa->fa_slen != slen) ||
 			    (fa->tb_id != tb->tb_id) ||
-			    (fa->fa_tos != tos))
+			    (fa->fa_dscp != dscp))
 				break;
 			if (fa->fa_info->fib_priority != fi->fib_priority)
 				break;
@@ -1292,7 +1298,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 				goto out;
 
 			fi_drop = fa->fa_info;
-			new_fa->fa_tos = fa->fa_tos;
+			new_fa->fa_dscp = fa->fa_dscp;
 			new_fa->fa_info = fi;
 			new_fa->fa_type = cfg->fc_type;
 			state = fa->fa_state;
@@ -1355,7 +1361,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 		goto out;
 
 	new_fa->fa_info = fi;
-	new_fa->fa_tos = tos;
+	new_fa->fa_dscp = dscp;
 	new_fa->fa_type = cfg->fc_type;
 	new_fa->fa_state = 0;
 	new_fa->fa_slen = slen;
@@ -1423,11 +1429,8 @@ bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
 	    !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
 		return false;
 
-	if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
-		if (flp->flowi4_oif &&
-		    flp->flowi4_oif != nhc->nhc_oif)
-			return false;
-	}
+	if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif)
+		return false;
 
 	return true;
 }
@@ -1571,7 +1574,8 @@ found:
 			if (index >= (1ul << fa->fa_slen))
 				continue;
 		}
-		if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+		if (fa->fa_dscp &&
+		    inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos)
 			continue;
 		if (fi->fib_dead)
 			continue;
@@ -1707,7 +1711,7 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 	struct key_vector *l, *tp;
 	u8 plen = cfg->fc_dst_len;
 	u8 slen = KEYLENGTH - plen;
-	u8 tos = cfg->fc_tos;
+	dscp_t dscp;
 	u32 key;
 
 	key = ntohl(cfg->fc_dst);
@@ -1719,11 +1723,13 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 	if (!l)
 		return -ESRCH;
 
-	fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id, false);
+	dscp = cfg->fc_dscp;
+	fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false);
 	if (!fa)
 		return -ESRCH;
 
-	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
+	pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen,
+		 inet_dscp_to_dsfield(dscp), t);
 
 	fa_to_delete = NULL;
 	hlist_for_each_entry_from(fa, fa_list) {
@@ -1731,7 +1737,7 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 
 		if ((fa->fa_slen != slen) ||
 		    (fa->tb_id != tb->tb_id) ||
-		    (fa->fa_tos != tos))
+		    (fa->fa_dscp != dscp))
 			break;
 
 		if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
@@ -2299,7 +2305,7 @@ static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
 				fri.tb_id = tb->tb_id;
 				fri.dst = xkey;
 				fri.dst_len = KEYLENGTH - fa->fa_slen;
-				fri.tos = fa->fa_tos;
+				fri.tos = inet_dscp_to_dsfield(fa->fa_dscp);
 				fri.type = fa->fa_type;
 				fri.offload = READ_ONCE(fa->offload);
 				fri.trap = READ_ONCE(fa->trap);
@@ -2811,8 +2817,9 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
 					     fa->fa_info->fib_scope),
 				   rtn_type(buf2, sizeof(buf2),
 					    fa->fa_type));
-			if (fa->fa_tos)
-				seq_printf(seq, " tos=%d", fa->fa_tos);
+			if (fa->fa_dscp)
+				seq_printf(seq, " tos=%d",
+					   inet_dscp_to_dsfield(fa->fa_dscp));
 			seq_putc(seq, '\n');
 		}
 	}
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index b7e277d8a84d..72a375c7f417 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -192,24 +192,14 @@ struct icmp_control {
 
 static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
 
-/*
- *	The ICMP socket(s). This is the most convenient way to flow control
- *	our ICMP output as well as maintain a clean interface throughout
- *	all layers. All Socketless IP sends will soon be gone.
- *
- *	On SMP we have one ICMP socket per-cpu.
- */
-static struct sock *icmp_sk(struct net *net)
-{
-	return this_cpu_read(*net->ipv4.icmp_sk);
-}
+static DEFINE_PER_CPU(struct sock *, ipv4_icmp_sk);
 
 /* Called with BH disabled */
 static inline struct sock *icmp_xmit_lock(struct net *net)
 {
 	struct sock *sk;
 
-	sk = icmp_sk(net);
+	sk = this_cpu_read(ipv4_icmp_sk);
 
 	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 		/* This can happen if the output path signals a
@@ -217,11 +207,13 @@ static inline struct sock *icmp_xmit_lock(struct net *net)
 		 */
 		return NULL;
 	}
+	sock_net_set(sk, net);
 	return sk;
 }
 
 static inline void icmp_xmit_unlock(struct sock *sk)
 {
+	sock_net_set(sk, &init_net);
 	spin_unlock(&sk->sk_lock.slock);
 }
 
@@ -363,14 +355,13 @@ static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
 	return 0;
 }
 
-static void icmp_push_reply(struct icmp_bxm *icmp_param,
+static void icmp_push_reply(struct sock *sk,
+			    struct icmp_bxm *icmp_param,
 			    struct flowi4 *fl4,
 			    struct ipcm_cookie *ipc, struct rtable **rt)
 {
-	struct sock *sk;
 	struct sk_buff *skb;
 
-	sk = icmp_sk(dev_net((*rt)->dst.dev));
 	if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
 			   icmp_param->data_len+icmp_param->head_len,
 			   icmp_param->head_len,
@@ -452,7 +443,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 	if (IS_ERR(rt))
 		goto out_unlock;
 	if (icmpv4_xrlim_allow(net, rt, &fl4, type, code))
-		icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
+		icmp_push_reply(sk, icmp_param, &fl4, &ipc, &rt);
 	ip_rt_put(rt);
 out_unlock:
 	icmp_xmit_unlock(sk);
@@ -766,7 +757,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 	if (!fl4.saddr)
 		fl4.saddr = htonl(INADDR_DUMMY);
 
-	icmp_push_reply(&icmp_param, &fl4, &ipc, &rt);
+	icmp_push_reply(sk, &icmp_param, &fl4, &ipc, &rt);
 ende:
 	ip_rt_put(rt);
 out_unlock:
@@ -1434,46 +1425,8 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
 	},
 };
 
-static void __net_exit icmp_sk_exit(struct net *net)
-{
-	int i;
-
-	for_each_possible_cpu(i)
-		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
-	free_percpu(net->ipv4.icmp_sk);
-	net->ipv4.icmp_sk = NULL;
-}
-
 static int __net_init icmp_sk_init(struct net *net)
 {
-	int i, err;
-
-	net->ipv4.icmp_sk = alloc_percpu(struct sock *);
-	if (!net->ipv4.icmp_sk)
-		return -ENOMEM;
-
-	for_each_possible_cpu(i) {
-		struct sock *sk;
-
-		err = inet_ctl_sock_create(&sk, PF_INET,
-					   SOCK_RAW, IPPROTO_ICMP, net);
-		if (err < 0)
-			goto fail;
-
-		*per_cpu_ptr(net->ipv4.icmp_sk, i) = sk;
-
-		/* Enough space for 2 64K ICMP packets, including
-		 * sk_buff/skb_shared_info struct overhead.
-		 */
-		sk->sk_sndbuf =	2 * SKB_TRUESIZE(64 * 1024);
-
-		/*
-		 * Speedup sock_wfree()
-		 */
-		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
-		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
-	}
-
 	/* Control parameters for ECHO replies. */
 	net->ipv4.sysctl_icmp_echo_ignore_all = 0;
 	net->ipv4.sysctl_icmp_echo_enable_probe = 0;
@@ -1499,18 +1452,36 @@ static int __net_init icmp_sk_init(struct net *net)
 	net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0;
 
 	return 0;
-
-fail:
-	icmp_sk_exit(net);
-	return err;
 }
 
 static struct pernet_operations __net_initdata icmp_sk_ops = {
        .init = icmp_sk_init,
-       .exit = icmp_sk_exit,
 };
 
 int __init icmp_init(void)
 {
+	int err, i;
+
+	for_each_possible_cpu(i) {
+		struct sock *sk;
+
+		err = inet_ctl_sock_create(&sk, PF_INET,
+					   SOCK_RAW, IPPROTO_ICMP, &init_net);
+		if (err < 0)
+			return err;
+
+		per_cpu(ipv4_icmp_sk, i) = sk;
+
+		/* Enough space for 2 64K ICMP packets, including
+		 * sk_buff/skb_shared_info struct overhead.
+		 */
+		sk->sk_sndbuf =	2 * SKB_TRUESIZE(64 * 1024);
+
+		/*
+		 * Speedup sock_wfree()
+		 */
+		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
+	}
 	return register_pernet_subsys(&icmp_sk_ops);
 }
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index fc2a985f6064..1e5b53c2bb26 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -866,12 +866,9 @@ static void reqsk_timer_handler(struct timer_list *t)
 	    (!resend ||
 	     !inet_rtx_syn_ack(sk_listener, req) ||
 	     inet_rsk(req)->acked)) {
-		unsigned long timeo;
-
 		if (req->num_timeout++ == 0)
 			atomic_dec(&queue->young);
-		timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
-		mod_timer(&req->rsk_timer, jiffies + timeo);
+		mod_timer(&req->rsk_timer, jiffies + reqsk_timeout(req, TCP_RTO_MAX));
 
 		if (!nreq)
 			return;
@@ -1046,6 +1043,9 @@ int inet_csk_listen_start(struct sock *sk)
 	sk->sk_ack_backlog = 0;
 	inet_csk_delack_init(sk);
 
+	if (sk->sk_txrehash == SOCK_TXREHASH_DEFAULT)
+		sk->sk_txrehash = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
+
 	/* There is race window here: we announce ourselves listening,
 	 * but this transition is still not validated by get_port().
 	 * It is OK, because this socket enters to hash table only
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 341096807100..63948f6aeca0 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -572,6 +572,7 @@ void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
 	skb_mark_not_on_list(head);
 	head->prev = NULL;
 	head->tstamp = q->stamp;
+	head->mono_delivery_time = q->mono_delivery_time;
 }
 EXPORT_SYMBOL(inet_frag_reasm_finish);
 
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 30ab717ff1b8..17440840a791 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -637,7 +637,9 @@ int __inet_hash(struct sock *sk, struct sock *osk)
 	int err = 0;
 
 	if (sk->sk_state != TCP_LISTEN) {
+		local_bh_disable();
 		inet_ehash_nolisten(sk, osk, NULL);
+		local_bh_enable();
 		return 0;
 	}
 	WARN_ON(!sk_unhashed(sk));
@@ -669,45 +671,54 @@ int inet_hash(struct sock *sk)
 {
 	int err = 0;
 
-	if (sk->sk_state != TCP_CLOSE) {
-		local_bh_disable();
+	if (sk->sk_state != TCP_CLOSE)
 		err = __inet_hash(sk, NULL);
-		local_bh_enable();
-	}
 
 	return err;
 }
 EXPORT_SYMBOL_GPL(inet_hash);
 
-void inet_unhash(struct sock *sk)
+static void __inet_unhash(struct sock *sk, struct inet_listen_hashbucket *ilb)
 {
-	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
-	struct inet_listen_hashbucket *ilb = NULL;
-	spinlock_t *lock;
-
 	if (sk_unhashed(sk))
 		return;
 
-	if (sk->sk_state == TCP_LISTEN) {
-		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
-		lock = &ilb->lock;
-	} else {
-		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
-	}
-	spin_lock_bh(lock);
-	if (sk_unhashed(sk))
-		goto unlock;
-
 	if (rcu_access_pointer(sk->sk_reuseport_cb))
 		reuseport_stop_listen_sock(sk);
 	if (ilb) {
+		struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+
 		inet_unhash2(hashinfo, sk);
 		ilb->count--;
 	}
 	__sk_nulls_del_node_init_rcu(sk);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
-unlock:
-	spin_unlock_bh(lock);
+}
+
+void inet_unhash(struct sock *sk)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+
+	if (sk_unhashed(sk))
+		return;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		struct inet_listen_hashbucket *ilb;
+
+		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
+		/* Don't disable bottom halves while acquiring the lock to
+		 * avoid circular locking dependency on PREEMPT_RT.
+		 */
+		spin_lock(&ilb->lock);
+		__inet_unhash(sk, ilb);
+		spin_unlock(&ilb->lock);
+	} else {
+		spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
+
+		spin_lock_bh(lock);
+		__inet_unhash(sk, NULL);
+		spin_unlock_bh(lock);
+	}
 }
 EXPORT_SYMBOL_GPL(inet_unhash);
 
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 437afe392e66..9e0bbd026560 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -52,14 +52,15 @@ static void inet_twsk_kill(struct inet_timewait_sock *tw)
 	spin_unlock(lock);
 
 	/* Disassociate with bind bucket. */
-	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num,
-			hashinfo->bhash_size)];
+	bhead = &hashinfo->bhash[tw->tw_bslot];
 
 	spin_lock(&bhead->lock);
 	inet_twsk_bind_unhash(tw, hashinfo);
 	spin_unlock(&bhead->lock);
 
-	atomic_dec(&tw->tw_dr->tw_count);
+	if (refcount_dec_and_test(&tw->tw_dr->tw_refcount))
+		kfree(tw->tw_dr);
+
 	inet_twsk_put(tw);
 }
 
@@ -110,8 +111,12 @@ void inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 	   Note, that any socket with inet->num != 0 MUST be bound in
 	   binding cache, even if it is closed.
 	 */
-	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num,
-			hashinfo->bhash_size)];
+	/* Cache inet_bhashfn(), because 'struct net' might be no longer
+	 * available later in inet_twsk_kill().
+	 */
+	tw->tw_bslot = inet_bhashfn(twsk_net(tw), inet->inet_num,
+				    hashinfo->bhash_size);
+	bhead = &hashinfo->bhash[tw->tw_bslot];
 	spin_lock(&bhead->lock);
 	tw->tw_tb = icsk->icsk_bind_hash;
 	WARN_ON(!icsk->icsk_bind_hash);
@@ -145,10 +150,6 @@ static void tw_timer_handler(struct timer_list *t)
 {
 	struct inet_timewait_sock *tw = from_timer(tw, t, tw_timer);
 
-	if (tw->tw_kill)
-		__NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED);
-	else
-		__NET_INC_STATS(twsk_net(tw), LINUX_MIB_TIMEWAITED);
 	inet_twsk_kill(tw);
 }
 
@@ -158,7 +159,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
 {
 	struct inet_timewait_sock *tw;
 
-	if (atomic_read(&dr->tw_count) >= dr->sysctl_max_tw_buckets)
+	if (refcount_read(&dr->tw_refcount) - 1 >= dr->sysctl_max_tw_buckets)
 		return NULL;
 
 	tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
@@ -244,59 +245,15 @@ void __inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo, bool rearm)
 	 * of PAWS.
 	 */
 
-	tw->tw_kill = timeo <= 4*HZ;
 	if (!rearm) {
+		bool kill = timeo <= 4*HZ;
+
+		__NET_INC_STATS(twsk_net(tw), kill ? LINUX_MIB_TIMEWAITKILLED :
+						     LINUX_MIB_TIMEWAITED);
 		BUG_ON(mod_timer(&tw->tw_timer, jiffies + timeo));
-		atomic_inc(&tw->tw_dr->tw_count);
+		refcount_inc(&tw->tw_dr->tw_refcount);
 	} else {
 		mod_timer_pending(&tw->tw_timer, jiffies + timeo);
 	}
 }
 EXPORT_SYMBOL_GPL(__inet_twsk_schedule);
-
-void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family)
-{
-	struct inet_timewait_sock *tw;
-	struct sock *sk;
-	struct hlist_nulls_node *node;
-	unsigned int slot;
-
-	for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {
-		struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
-restart_rcu:
-		cond_resched();
-		rcu_read_lock();
-restart:
-		sk_nulls_for_each_rcu(sk, node, &head->chain) {
-			if (sk->sk_state != TCP_TIME_WAIT)
-				continue;
-			tw = inet_twsk(sk);
-			if ((tw->tw_family != family) ||
-				refcount_read(&twsk_net(tw)->ns.count))
-				continue;
-
-			if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt)))
-				continue;
-
-			if (unlikely((tw->tw_family != family) ||
-				     refcount_read(&twsk_net(tw)->ns.count))) {
-				inet_twsk_put(tw);
-				goto restart;
-			}
-
-			rcu_read_unlock();
-			local_bh_disable();
-			inet_twsk_deschedule_put(tw);
-			local_bh_enable();
-			goto restart_rcu;
-		}
-		/* If the nulls value we got at the end of this lookup is
-		 * not the expected one, we must restart lookup.
-		 * We probably met an item that was moved to another chain.
-		 */
-		if (get_nulls_value(node) != slot)
-			goto restart;
-		rcu_read_unlock();
-	}
-}
-EXPORT_SYMBOL_GPL(inet_twsk_purge);
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 00ec819f949b..92ba3350274b 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -79,7 +79,7 @@ static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *s
 	if (unlikely(opt->optlen))
 		ip_forward_options(skb);
 
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	return dst_output(net, sk, skb);
 }
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index fad803d2d711..fb153569889e 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -349,6 +349,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		qp->iif = dev->ifindex;
 
 	qp->q.stamp = skb->tstamp;
+	qp->q.mono_delivery_time = skb->mono_delivery_time;
 	qp->q.meat += skb->len;
 	qp->ecn |= ecn;
 	add_frag_mem_limit(qp->q.fqdir, skb->truesize);
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 3a025c011971..95f7bb052784 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -196,7 +196,8 @@ resubmit:
 	if (ipprot) {
 		if (!ipprot->no_policy) {
 			if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
-				kfree_skb(skb);
+				kfree_skb_reason(skb,
+						 SKB_DROP_REASON_XFRM_POLICY);
 				return;
 			}
 			nf_reset_ct(skb);
@@ -215,7 +216,7 @@ resubmit:
 				icmp_send(skb, ICMP_DEST_UNREACH,
 					  ICMP_PROT_UNREACH, 0);
 			}
-			kfree_skb(skb);
+			kfree_skb_reason(skb, SKB_DROP_REASON_IP_NOPROTO);
 		} else {
 			__IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS);
 			consume_skb(skb);
@@ -225,6 +226,7 @@ resubmit:
 
 static int ip_local_deliver_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
+	skb_clear_delivery_time(skb);
 	__skb_pull(skb, skb_network_header_len(skb));
 
 	rcu_read_lock();
@@ -318,8 +320,10 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 {
 	const struct iphdr *iph = ip_hdr(skb);
 	int (*edemux)(struct sk_buff *skb);
+	int err, drop_reason;
 	struct rtable *rt;
-	int err;
+
+	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 
 	if (ip_can_use_hint(skb, iph, hint)) {
 		err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos,
@@ -396,19 +400,23 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 		 * so-called "hole-196" attack) so do it for both.
 		 */
 		if (in_dev &&
-		    IN_DEV_ORCONF(in_dev, DROP_UNICAST_IN_L2_MULTICAST))
+		    IN_DEV_ORCONF(in_dev, DROP_UNICAST_IN_L2_MULTICAST)) {
+			drop_reason = SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST;
 			goto drop;
+		}
 	}
 
 	return NET_RX_SUCCESS;
 
 drop:
-	kfree_skb(skb);
+	kfree_skb_reason(skb, drop_reason);
 	return NET_RX_DROP;
 
 drop_error:
-	if (err == -EXDEV)
+	if (err == -EXDEV) {
+		drop_reason = SKB_DROP_REASON_IP_RPFILTER;
 		__NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
+	}
 	goto drop;
 }
 
@@ -436,13 +444,16 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
 {
 	const struct iphdr *iph;
+	int drop_reason;
 	u32 len;
 
 	/* When the interface is in promisc. mode, drop all the crap
 	 * that it receives, do not try to analyse it.
 	 */
-	if (skb->pkt_type == PACKET_OTHERHOST)
+	if (skb->pkt_type == PACKET_OTHERHOST) {
+		drop_reason = SKB_DROP_REASON_OTHERHOST;
 		goto drop;
+	}
 
 	__IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len);
 
@@ -452,6 +463,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
 		goto out;
 	}
 
+	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 		goto inhdr_error;
 
@@ -488,6 +500,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
 
 	len = ntohs(iph->tot_len);
 	if (skb->len < len) {
+		drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
 		__IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS);
 		goto drop;
 	} else if (len < (iph->ihl*4))
@@ -516,11 +529,14 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
 	return skb;
 
 csum_error:
+	drop_reason = SKB_DROP_REASON_IP_CSUM;
 	__IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS);
 inhdr_error:
+	if (drop_reason == SKB_DROP_REASON_NOT_SPECIFIED)
+		drop_reason = SKB_DROP_REASON_IP_INHDR;
 	__IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS);
 drop:
-	kfree_skb(skb);
+	kfree_skb_reason(skb, drop_reason);
 out:
 	return NULL;
 }
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index da1b5038bdfd..a9e22a098872 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -42,7 +42,7 @@
  */
 
 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
-		      __be32 daddr, struct rtable *rt, int is_frag)
+		      __be32 daddr, struct rtable *rt)
 {
 	unsigned char *iph = skb_network_header(skb);
 
@@ -53,28 +53,15 @@ void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 	if (opt->srr)
 		memcpy(iph + opt->srr + iph[opt->srr + 1] - 4, &daddr, 4);
 
-	if (!is_frag) {
-		if (opt->rr_needaddr)
-			ip_rt_get_source(iph + opt->rr + iph[opt->rr + 2] - 5, skb, rt);
-		if (opt->ts_needaddr)
-			ip_rt_get_source(iph + opt->ts + iph[opt->ts + 2] - 9, skb, rt);
-		if (opt->ts_needtime) {
-			__be32 midtime;
+	if (opt->rr_needaddr)
+		ip_rt_get_source(iph + opt->rr + iph[opt->rr + 2] - 5, skb, rt);
+	if (opt->ts_needaddr)
+		ip_rt_get_source(iph + opt->ts + iph[opt->ts + 2] - 9, skb, rt);
+	if (opt->ts_needtime) {
+		__be32 midtime;
 
-			midtime = inet_current_timestamp();
-			memcpy(iph + opt->ts + iph[opt->ts + 2] - 5, &midtime, 4);
-		}
-		return;
-	}
-	if (opt->rr) {
-		memset(iph + opt->rr, IPOPT_NOP, iph[opt->rr + 1]);
-		opt->rr = 0;
-		opt->rr_needaddr = 0;
-	}
-	if (opt->ts) {
-		memset(iph + opt->ts, IPOPT_NOP, iph[opt->ts + 1]);
-		opt->ts = 0;
-		opt->ts_needaddr = opt->ts_needtime = 0;
+		midtime = inet_current_timestamp();
+		memcpy(iph + opt->ts + iph[opt->ts + 2] - 5, &midtime, 4);
 	}
 }
 
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 7911916a480b..00b4bf26fd93 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -179,7 +179,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
 
 	if (opt && opt->opt.optlen) {
 		iph->ihl += opt->opt.optlen>>2;
-		ip_options_build(skb, &opt->opt, daddr, rt, 0);
+		ip_options_build(skb, &opt->opt, daddr, rt);
 	}
 
 	skb->priority = sk->sk_priority;
@@ -233,7 +233,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s
 
 	net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
 			    __func__);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
 	return -EINVAL;
 }
 
@@ -317,7 +317,7 @@ static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *sk
 	case NET_XMIT_CN:
 		return __ip_finish_output(net, sk, skb) ? : ret;
 	default:
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);
 		return ret;
 	}
 }
@@ -337,7 +337,7 @@ static int ip_mc_finish_output(struct net *net, struct sock *sk,
 	case NET_XMIT_SUCCESS:
 		break;
 	default:
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);
 		return ret;
 	}
 
@@ -519,7 +519,7 @@ packet_routed:
 
 	if (inet_opt && inet_opt->opt.optlen) {
 		iph->ihl += inet_opt->opt.optlen >> 2;
-		ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
+		ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt);
 	}
 
 	ip_select_ident_segs(net, skb, sk,
@@ -536,7 +536,7 @@ packet_routed:
 no_route:
 	rcu_read_unlock();
 	IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, SKB_DROP_REASON_IP_OUTNOROUTES);
 	return -EHOSTUNREACH;
 }
 EXPORT_SYMBOL(__ip_queue_xmit);
@@ -761,6 +761,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 {
 	struct iphdr *iph;
 	struct sk_buff *skb2;
+	bool mono_delivery_time = skb->mono_delivery_time;
 	struct rtable *rt = skb_rtable(skb);
 	unsigned int mtu, hlen, ll_rs;
 	struct ip_fraglist_iter iter;
@@ -852,7 +853,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 				}
 			}
 
-			skb->tstamp = tstamp;
+			skb_set_delivery_time(skb, tstamp, mono_delivery_time);
 			err = output(net, sk, skb);
 
 			if (!err)
@@ -908,7 +909,7 @@ slow_path:
 		/*
 		 *	Put this fragment into the sending queue.
 		 */
-		skb2->tstamp = tstamp;
+		skb_set_delivery_time(skb2, tstamp, mono_delivery_time);
 		err = output(net, sk, skb2);
 		if (err)
 			goto fail;
@@ -1541,7 +1542,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 
 	if (opt) {
 		iph->ihl += opt->optlen >> 2;
-		ip_options_build(skb, opt, cork->addr, rt, 0);
+		ip_options_build(skb, opt, cork->addr, rt);
 	}
 
 	skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority;
@@ -1727,6 +1728,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 			  arg->csumoffset) = csum_fold(csum_add(nskb->csum,
 								arg->csum));
 		nskb->ip_summed = CHECKSUM_NONE;
+		nskb->mono_delivery_time = !!transmit_time;
 		ip_push_pending_frames(sk, &fl4);
 	}
 out:
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 29bbe2b08ae9..c860519d57ee 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -268,13 +268,12 @@ static void __net_exit ipmr_rules_exit(struct net *net)
 {
 	struct mr_table *mrt, *next;
 
-	rtnl_lock();
+	ASSERT_RTNL();
 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
 		list_del(&mrt->list);
 		ipmr_free_table(mrt);
 	}
 	fib_rules_unregister(net->ipv4.mr_rules_ops);
-	rtnl_unlock();
 }
 
 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
@@ -330,10 +329,9 @@ static int __net_init ipmr_rules_init(struct net *net)
 
 static void __net_exit ipmr_rules_exit(struct net *net)
 {
-	rtnl_lock();
+	ASSERT_RTNL();
 	ipmr_free_table(net->ipv4.mrt);
 	net->ipv4.mrt = NULL;
-	rtnl_unlock();
 }
 
 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
@@ -3077,7 +3075,9 @@ static int __net_init ipmr_net_init(struct net *net)
 proc_cache_fail:
 	remove_proc_entry("ip_mr_vif", net->proc_net);
 proc_vif_fail:
+	rtnl_lock();
 	ipmr_rules_exit(net);
+	rtnl_unlock();
 #endif
 ipmr_rules_fail:
 	ipmr_notifier_exit(net);
@@ -3092,12 +3092,22 @@ static void __net_exit ipmr_net_exit(struct net *net)
 	remove_proc_entry("ip_mr_vif", net->proc_net);
 #endif
 	ipmr_notifier_exit(net);
-	ipmr_rules_exit(net);
+}
+
+static void __net_exit ipmr_net_exit_batch(struct list_head *net_list)
+{
+	struct net *net;
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list)
+		ipmr_rules_exit(net);
+	rtnl_unlock();
 }
 
 static struct pernet_operations ipmr_net_ops = {
 	.init = ipmr_net_init,
 	.exit = ipmr_net_exit,
+	.exit_batch = ipmr_net_exit_batch,
 };
 
 int __init ip_mr_init(void)
diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
index 3e2685c120c7..76a411ae9fe6 100644
--- a/net/ipv4/netfilter/nf_nat_h323.c
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -580,7 +580,7 @@ static struct nf_ct_helper_expectfn callforwarding_nat = {
 };
 
 /****************************************************************************/
-static int __init init(void)
+static int __init nf_nat_h323_init(void)
 {
 	BUG_ON(set_h245_addr_hook != NULL);
 	BUG_ON(set_h225_addr_hook != NULL);
@@ -607,7 +607,7 @@ static int __init init(void)
 }
 
 /****************************************************************************/
-static void __exit fini(void)
+static void __exit nf_nat_h323_fini(void)
 {
 	RCU_INIT_POINTER(set_h245_addr_hook, NULL);
 	RCU_INIT_POINTER(set_h225_addr_hook, NULL);
@@ -624,8 +624,8 @@ static void __exit fini(void)
 }
 
 /****************************************************************************/
-module_init(init);
-module_exit(fini);
+module_init(nf_nat_h323_init);
+module_exit(nf_nat_h323_fini);
 
 MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
 MODULE_DESCRIPTION("H.323 NAT helper");
diff --git a/net/ipv4/netfilter/nf_nat_pptp.c b/net/ipv4/netfilter/nf_nat_pptp.c
index 3f248a19faa3..fab357cc8559 100644
--- a/net/ipv4/netfilter/nf_nat_pptp.c
+++ b/net/ipv4/netfilter/nf_nat_pptp.c
@@ -295,28 +295,24 @@ pptp_inbound_pkt(struct sk_buff *skb,
 	return NF_ACCEPT;
 }
 
+static const struct nf_nat_pptp_hook pptp_hooks = {
+	.outbound = pptp_outbound_pkt,
+	.inbound = pptp_inbound_pkt,
+	.exp_gre = pptp_exp_gre,
+	.expectfn = pptp_nat_expected,
+};
+
 static int __init nf_nat_helper_pptp_init(void)
 {
-	BUG_ON(nf_nat_pptp_hook_outbound != NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_outbound, pptp_outbound_pkt);
-
-	BUG_ON(nf_nat_pptp_hook_inbound != NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_inbound, pptp_inbound_pkt);
-
-	BUG_ON(nf_nat_pptp_hook_exp_gre != NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_exp_gre, pptp_exp_gre);
+	WARN_ON(nf_nat_pptp_hook != NULL);
+	RCU_INIT_POINTER(nf_nat_pptp_hook, &pptp_hooks);
 
-	BUG_ON(nf_nat_pptp_hook_expectfn != NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_expectfn, pptp_nat_expected);
 	return 0;
 }
 
 static void __exit nf_nat_helper_pptp_fini(void)
 {
-	RCU_INIT_POINTER(nf_nat_pptp_hook_expectfn, NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_exp_gre, NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_inbound, NULL);
-	RCU_INIT_POINTER(nf_nat_pptp_hook_outbound, NULL);
+	RCU_INIT_POINTER(nf_nat_pptp_hook, NULL);
 	synchronize_rcu();
 }
 
diff --git a/net/ipv4/netfilter/nft_dup_ipv4.c b/net/ipv4/netfilter/nft_dup_ipv4.c
index aeb631760eb9..0bcd6aee6000 100644
--- a/net/ipv4/netfilter/nft_dup_ipv4.c
+++ b/net/ipv4/netfilter/nft_dup_ipv4.c
@@ -75,6 +75,7 @@ static const struct nft_expr_ops nft_dup_ipv4_ops = {
 	.eval		= nft_dup_ipv4_eval,
 	.init		= nft_dup_ipv4_init,
 	.dump		= nft_dup_ipv4_dump,
+	.reduce		= NFT_REDUCE_READONLY,
 };
 
 static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = {
diff --git a/net/ipv4/netfilter/nft_fib_ipv4.c b/net/ipv4/netfilter/nft_fib_ipv4.c
index 03df986217b7..4151eb1262dd 100644
--- a/net/ipv4/netfilter/nft_fib_ipv4.c
+++ b/net/ipv4/netfilter/nft_fib_ipv4.c
@@ -152,6 +152,7 @@ static const struct nft_expr_ops nft_fib4_type_ops = {
 	.init		= nft_fib_init,
 	.dump		= nft_fib_dump,
 	.validate	= nft_fib_validate,
+	.reduce		= nft_fib_reduce,
 };
 
 static const struct nft_expr_ops nft_fib4_ops = {
@@ -161,6 +162,7 @@ static const struct nft_expr_ops nft_fib4_ops = {
 	.init		= nft_fib_init,
 	.dump		= nft_fib_dump,
 	.validate	= nft_fib_validate,
+	.reduce		= nft_fib_reduce,
 };
 
 static const struct nft_expr_ops *
diff --git a/net/ipv4/netfilter/nft_reject_ipv4.c b/net/ipv4/netfilter/nft_reject_ipv4.c
index 55fc23a8f7a7..6cb213bb7256 100644
--- a/net/ipv4/netfilter/nft_reject_ipv4.c
+++ b/net/ipv4/netfilter/nft_reject_ipv4.c
@@ -45,6 +45,7 @@ static const struct nft_expr_ops nft_reject_ipv4_ops = {
 	.init		= nft_reject_init,
 	.dump		= nft_reject_dump,
 	.validate	= nft_reject_validate,
+	.reduce		= NFT_REDUCE_READONLY,
 };
 
 static struct nft_expr_type nft_reject_ipv4_type __read_mostly = {
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index eeafeccebb8d..e459a391e607 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -3733,12 +3733,16 @@ out:
 }
 EXPORT_SYMBOL(nexthop_res_grp_activity_update);
 
-static void __net_exit nexthop_net_exit(struct net *net)
+static void __net_exit nexthop_net_exit_batch(struct list_head *net_list)
 {
+	struct net *net;
+
 	rtnl_lock();
-	flush_all_nexthops(net);
+	list_for_each_entry(net, net_list, exit_list) {
+		flush_all_nexthops(net);
+		kfree(net->nexthop.devhash);
+	}
 	rtnl_unlock();
-	kfree(net->nexthop.devhash);
 }
 
 static int __net_init nexthop_net_init(struct net *net)
@@ -3756,7 +3760,7 @@ static int __net_init nexthop_net_init(struct net *net)
 
 static struct pernet_operations nexthop_net_ops = {
 	.init = nexthop_net_init,
-	.exit = nexthop_net_exit,
+	.exit_batch = nexthop_net_exit_batch,
 };
 
 static int __init nexthop_init(void)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index f30273afb539..28836071f0a6 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -59,8 +59,8 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 	socket_seq_show(seq);
 	seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n",
 		   sock_prot_inuse_get(net, &tcp_prot), orphans,
-		   atomic_read(&net->ipv4.tcp_death_row.tw_count), sockets,
-		   proto_memory_allocated(&tcp_prot));
+		   refcount_read(&net->ipv4.tcp_death_row->tw_refcount) - 1,
+		   sockets, proto_memory_allocated(&tcp_prot));
 	seq_printf(seq, "UDP: inuse %d mem %ld\n",
 		   sock_prot_inuse_get(net, &udp_prot),
 		   proto_memory_allocated(&udp_prot));
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f33ad1f383b6..98c6f3429593 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -84,6 +84,7 @@
 #include <linux/jhash.h>
 #include <net/dst.h>
 #include <net/dst_metadata.h>
+#include <net/inet_dscp.h>
 #include <net/net_namespace.h>
 #include <net/ip.h>
 #include <net/route.h>
@@ -112,14 +113,13 @@
 
 #define DEFAULT_MIN_PMTU (512 + 20 + 20)
 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
-
+#define DEFAULT_MIN_ADVMSS 256
 static int ip_rt_max_size;
 static int ip_rt_redirect_number __read_mostly	= 9;
 static int ip_rt_redirect_load __read_mostly	= HZ / 50;
 static int ip_rt_redirect_silence __read_mostly	= ((HZ / 50) << (9 + 1));
 static int ip_rt_error_cost __read_mostly	= HZ;
 static int ip_rt_error_burst __read_mostly	= 5 * HZ;
-static int ip_rt_min_advmss __read_mostly	= 256;
 
 static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
 
@@ -458,7 +458,7 @@ static u32 *ip_tstamps __read_mostly;
  * if one generator is seldom used. This makes hard for an attacker
  * to infer how many packets were sent between two points in time.
  */
-u32 ip_idents_reserve(u32 hash, int segs)
+static u32 ip_idents_reserve(u32 hash, int segs)
 {
 	u32 bucket, old, now = (u32)jiffies;
 	atomic_t *p_id;
@@ -479,7 +479,6 @@ u32 ip_idents_reserve(u32 hash, int segs)
 	 */
 	return atomic_add_return(segs + delta, p_id) - segs;
 }
-EXPORT_SYMBOL(ip_idents_reserve);
 
 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
 {
@@ -499,6 +498,15 @@ void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
 }
 EXPORT_SYMBOL(__ip_select_ident);
 
+static void ip_rt_fix_tos(struct flowi4 *fl4)
+{
+	__u8 tos = RT_FL_TOS(fl4);
+
+	fl4->flowi4_tos = tos & IPTOS_RT_MASK;
+	fl4->flowi4_scope = tos & RTO_ONLINK ?
+			    RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
+}
+
 static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
 			     const struct sock *sk,
 			     const struct iphdr *iph,
@@ -824,6 +832,7 @@ static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buf
 	rt = (struct rtable *) dst;
 
 	__build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
+	ip_rt_fix_tos(&fl4);
 	__ip_do_redirect(rt, skb, &fl4, true);
 }
 
@@ -1048,6 +1057,7 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 	struct flowi4 fl4;
 
 	ip_rt_build_flow_key(&fl4, sk, skb);
+	ip_rt_fix_tos(&fl4);
 
 	/* Don't make lookup fail for bridged encapsulations */
 	if (skb && netif_is_any_bridge_port(skb->dev))
@@ -1122,6 +1132,8 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 			goto out;
 
 		new = true;
+	} else {
+		ip_rt_fix_tos(&fl4);
 	}
 
 	__ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu);
@@ -1298,9 +1310,10 @@ static void set_class_tag(struct rtable *rt, u32 tag)
 
 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
 {
+	struct net *net = dev_net(dst->dev);
 	unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
 	unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
-				    ip_rt_min_advmss);
+				    net->ipv4.ip_rt_min_advmss);
 
 	return min(advmss, IPV4_MAX_PMTU - header_size);
 }
@@ -1485,6 +1498,7 @@ static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
 struct uncached_list {
 	spinlock_t		lock;
 	struct list_head	head;
+	struct list_head	quarantine;
 };
 
 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
@@ -1506,7 +1520,7 @@ void rt_del_uncached_list(struct rtable *rt)
 		struct uncached_list *ul = rt->rt_uncached_list;
 
 		spin_lock_bh(&ul->lock);
-		list_del(&rt->rt_uncached);
+		list_del_init(&rt->rt_uncached);
 		spin_unlock_bh(&ul->lock);
 	}
 }
@@ -1521,20 +1535,24 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 
 void rt_flush_dev(struct net_device *dev)
 {
-	struct rtable *rt;
+	struct rtable *rt, *safe;
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
 		struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
 
+		if (list_empty(&ul->head))
+			continue;
+
 		spin_lock_bh(&ul->lock);
-		list_for_each_entry(rt, &ul->head, rt_uncached) {
+		list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) {
 			if (rt->dst.dev != dev)
 				continue;
 			rt->dst.dev = blackhole_netdev;
 			dev_replace_track(dev, blackhole_netdev,
 					  &rt->dst.dev_tracker,
 					  GFP_ATOMIC);
+			list_move(&rt->rt_uncached, &ul->quarantine);
 		}
 		spin_unlock_bh(&ul->lock);
 	}
@@ -2258,6 +2276,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	/*
 	 *	Now we are ready to route packet.
 	 */
+	fl4.flowi4_l3mdev = 0;
 	fl4.flowi4_oif = 0;
 	fl4.flowi4_iif = dev->ifindex;
 	fl4.flowi4_mark = skb->mark;
@@ -2603,7 +2622,6 @@ add:
 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
 					const struct sk_buff *skb)
 {
-	__u8 tos = RT_FL_TOS(fl4);
 	struct fib_result res = {
 		.type		= RTN_UNSPEC,
 		.fi		= NULL,
@@ -2613,9 +2631,7 @@ struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
 	struct rtable *rth;
 
 	fl4->flowi4_iif = LOOPBACK_IFINDEX;
-	fl4->flowi4_tos = tos & IPTOS_RT_MASK;
-	fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
-			 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
+	ip_rt_fix_tos(fl4);
 
 	rcu_read_lock();
 	rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
@@ -2733,8 +2749,7 @@ struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
 		res->fi = NULL;
 		res->table = NULL;
 		if (fl4->flowi4_oif &&
-		    (ipv4_is_multicast(fl4->daddr) ||
-		    !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
+		    (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) {
 			/* Apparently, routing tables are wrong. Assume,
 			 * that the destination is on link.
 			 *
@@ -3392,7 +3407,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 				if (fa->fa_slen == slen &&
 				    fa->tb_id == fri.tb_id &&
-				    fa->fa_tos == fri.tos &&
+				    fa->fa_dscp == inet_dsfield_to_dscp(fri.tos) &&
 				    fa->fa_info == res.fi &&
 				    fa->fa_type == fri.type) {
 					fri.offload = READ_ONCE(fa->offload);
@@ -3535,13 +3550,6 @@ static struct ctl_table ipv4_route_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-	{
-		.procname	= "min_adv_mss",
-		.data		= &ip_rt_min_advmss,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
 	{ }
 };
 
@@ -3569,6 +3577,13 @@ static struct ctl_table ipv4_route_netns_table[] = {
 		.mode           = 0644,
 		.proc_handler   = proc_dointvec_jiffies,
 	},
+	{
+		.procname   = "min_adv_mss",
+		.data       = &init_net.ipv4.ip_rt_min_advmss,
+		.maxlen     = sizeof(int),
+		.mode       = 0644,
+		.proc_handler   = proc_dointvec,
+	},
 	{ },
 };
 
@@ -3631,6 +3646,7 @@ static __net_init int netns_ip_rt_init(struct net *net)
 	/* Set default value for namespaceified sysctls */
 	net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU;
 	net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
+	net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
 	return 0;
 }
 
@@ -3705,6 +3721,7 @@ int __init ip_rt_init(void)
 		struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
 
 		INIT_LIST_HEAD(&ul->head);
+		INIT_LIST_HEAD(&ul->quarantine);
 		spin_lock_init(&ul->lock);
 	}
 #ifdef CONFIG_IP_ROUTE_CLASSID
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 97eb54774924..ad80d180b60b 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -589,6 +589,14 @@ static struct ctl_table ipv4_table[] = {
 };
 
 static struct ctl_table ipv4_net_table[] = {
+	/* tcp_max_tw_buckets must be first in this table. */
+	{
+		.procname	= "tcp_max_tw_buckets",
+/*		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets, */
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{
 		.procname	= "icmp_echo_ignore_all",
 		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
@@ -1001,13 +1009,6 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra2		= &two,
 	},
 	{
-		.procname	= "tcp_max_tw_buckets",
-		.data		= &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-	{
 		.procname	= "tcp_max_syn_backlog",
 		.data		= &init_net.ipv4.sysctl_max_syn_backlog,
 		.maxlen		= sizeof(int),
@@ -1271,6 +1272,13 @@ static struct ctl_table ipv4_net_table[] = {
 		.extra1		= SYSCTL_ONE,
 	},
 	{
+		.procname	= "tcp_tso_rtt_log",
+		.data		= &init_net.ipv4.sysctl_tcp_tso_rtt_log,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler	= proc_dou8vec_minmax,
+	},
+	{
 		.procname	= "tcp_min_rtt_wlen",
 		.data		= &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
 		.maxlen		= sizeof(int),
@@ -1400,7 +1408,8 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 		if (!table)
 			goto err_alloc;
 
-		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) {
+		/* skip first entry (sysctl_max_tw_buckets) */
+		for (i = 1; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) {
 			if (table[i].data) {
 				/* Update the variables to point into
 				 * the current struct net
@@ -1415,6 +1424,8 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 		}
 	}
 
+	table[0].data = &net->ipv4.tcp_death_row->sysctl_max_tw_buckets;
+
 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
 	if (!net->ipv4.ipv4_hdr)
 		goto err_reg;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 28ff2a820f7c..cf18fbcbf123 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -688,7 +688,8 @@ static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
 	return skb->len < size_goal &&
 	       sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
 	       !tcp_rtx_queue_empty(sk) &&
-	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
+	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize &&
+	       tcp_skb_can_collapse_to(skb);
 }
 
 void tcp_push(struct sock *sk, int flags, int mss_now,
@@ -894,8 +895,7 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
 		return mss_now;
 
 	/* Note : tcp_tso_autosize() will eventually split this later */
-	new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
-	new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);
+	new_size_goal = tcp_bound_to_half_wnd(tp, sk->sk_gso_max_size);
 
 	/* We try hard to avoid divides here */
 	size_goal = tp->gso_segs * mss_now;
@@ -4434,6 +4434,73 @@ int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *ke
 }
 EXPORT_SYMBOL(tcp_md5_hash_key);
 
+/* Called with rcu_read_lock() */
+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)
+{
+	/*
+	 * This gets called for each TCP segment that arrives
+	 * so we want to be efficient.
+	 * 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);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int genhash, l3index;
+	u8 newhash[16];
+
+	/* sdif set, means packet ingressed via a device
+	 * in an L3 domain and dif is set to the l3mdev
+	 */
+	l3index = sdif ? dif : 0;
+
+	hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family);
+	hash_location = tcp_parse_md5sig_option(th);
+
+	/* 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) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+		return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
+	}
+
+	/* check the signature */
+	genhash = tp->af_specific->calc_md5_hash(newhash, hash_expected,
+						 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);
+		} 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);
+		}
+		return SKB_DROP_REASON_TCP_MD5FAILURE;
+	}
+	return SKB_NOT_DROPPED_YET;
+}
+EXPORT_SYMBOL(tcp_inbound_md5_hash);
+
 #endif
 
 void tcp_done(struct sock *sk)
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index ec5550089b4d..02e8626ccb27 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -1154,7 +1154,7 @@ static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = {
 	.set_state	= bbr_set_state,
 };
 
-BTF_SET_START(tcp_bbr_kfunc_ids)
+BTF_SET_START(tcp_bbr_check_kfunc_ids)
 #ifdef CONFIG_X86
 #ifdef CONFIG_DYNAMIC_FTRACE
 BTF_ID(func, bbr_init)
@@ -1167,25 +1167,27 @@ BTF_ID(func, bbr_min_tso_segs)
 BTF_ID(func, bbr_set_state)
 #endif
 #endif
-BTF_SET_END(tcp_bbr_kfunc_ids)
+BTF_SET_END(tcp_bbr_check_kfunc_ids)
 
-static DEFINE_KFUNC_BTF_ID_SET(&tcp_bbr_kfunc_ids, tcp_bbr_kfunc_btf_set);
+static const struct btf_kfunc_id_set tcp_bbr_kfunc_set = {
+	.owner     = THIS_MODULE,
+	.check_set = &tcp_bbr_check_kfunc_ids,
+};
 
 static int __init bbr_register(void)
 {
 	int ret;
 
 	BUILD_BUG_ON(sizeof(struct bbr) > ICSK_CA_PRIV_SIZE);
-	ret = tcp_register_congestion_control(&tcp_bbr_cong_ops);
-	if (ret)
+
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &tcp_bbr_kfunc_set);
+	if (ret < 0)
 		return ret;
-	register_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_bbr_kfunc_btf_set);
-	return 0;
+	return tcp_register_congestion_control(&tcp_bbr_cong_ops);
 }
 
 static void __exit bbr_unregister(void)
 {
-	unregister_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_bbr_kfunc_btf_set);
 	tcp_unregister_congestion_control(&tcp_bbr_cong_ops);
 }
 
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 9b9b02052fd3..1cdcb4df0eb7 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -138,10 +138,9 @@ int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
 	struct sk_psock *psock = sk_psock_get(sk);
 	int ret;
 
-	if (unlikely(!psock)) {
-		sk_msg_free(sk, msg);
-		return 0;
-	}
+	if (unlikely(!psock))
+		return -EPIPE;
+
 	ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
 			tcp_bpf_push_locked(sk, msg, bytes, flags, false);
 	sk_psock_put(sk, psock);
@@ -335,7 +334,7 @@ more_data:
 			cork = true;
 			psock->cork = NULL;
 		}
-		sk_msg_return(sk, msg, tosend);
+		sk_msg_return(sk, msg, msg->sg.size);
 		release_sock(sk);
 
 		ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
@@ -375,8 +374,11 @@ more_data:
 		}
 		if (msg &&
 		    msg->sg.data[msg->sg.start].page_link &&
-		    msg->sg.data[msg->sg.start].length)
+		    msg->sg.data[msg->sg.start].length) {
+			if (eval == __SK_REDIRECT)
+				sk_mem_charge(sk, msg->sg.size);
 			goto more_data;
+		}
 	}
 	return ret;
 }
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index db5831e6c136..dc95572163df 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -135,7 +135,6 @@ u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca)
 
 	return key;
 }
-EXPORT_SYMBOL_GPL(tcp_ca_get_key_by_name);
 
 char *tcp_ca_get_name_by_key(u32 key, char *buffer)
 {
@@ -151,7 +150,6 @@ char *tcp_ca_get_name_by_key(u32 key, char *buffer)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(tcp_ca_get_name_by_key);
 
 /* Assign choice of congestion control. */
 void tcp_assign_congestion_control(struct sock *sk)
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index e07837e23b3f..24d562dd6225 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -485,7 +485,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
 	.name		= "cubic",
 };
 
-BTF_SET_START(tcp_cubic_kfunc_ids)
+BTF_SET_START(tcp_cubic_check_kfunc_ids)
 #ifdef CONFIG_X86
 #ifdef CONFIG_DYNAMIC_FTRACE
 BTF_ID(func, cubictcp_init)
@@ -496,9 +496,12 @@ BTF_ID(func, cubictcp_cwnd_event)
 BTF_ID(func, cubictcp_acked)
 #endif
 #endif
-BTF_SET_END(tcp_cubic_kfunc_ids)
+BTF_SET_END(tcp_cubic_check_kfunc_ids)
 
-static DEFINE_KFUNC_BTF_ID_SET(&tcp_cubic_kfunc_ids, tcp_cubic_kfunc_btf_set);
+static const struct btf_kfunc_id_set tcp_cubic_kfunc_set = {
+	.owner     = THIS_MODULE,
+	.check_set = &tcp_cubic_check_kfunc_ids,
+};
 
 static int __init cubictcp_register(void)
 {
@@ -534,16 +537,14 @@ static int __init cubictcp_register(void)
 	/* divide by bic_scale and by constant Srtt (100ms) */
 	do_div(cube_factor, bic_scale * 10);
 
-	ret = tcp_register_congestion_control(&cubictcp);
-	if (ret)
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &tcp_cubic_kfunc_set);
+	if (ret < 0)
 		return ret;
-	register_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_cubic_kfunc_btf_set);
-	return 0;
+	return tcp_register_congestion_control(&cubictcp);
 }
 
 static void __exit cubictcp_unregister(void)
 {
-	unregister_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_cubic_kfunc_btf_set);
 	tcp_unregister_congestion_control(&cubictcp);
 }
 
diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
index 0d7ab3cc7b61..1943a6630341 100644
--- a/net/ipv4/tcp_dctcp.c
+++ b/net/ipv4/tcp_dctcp.c
@@ -238,7 +238,7 @@ static struct tcp_congestion_ops dctcp_reno __read_mostly = {
 	.name		= "dctcp-reno",
 };
 
-BTF_SET_START(tcp_dctcp_kfunc_ids)
+BTF_SET_START(tcp_dctcp_check_kfunc_ids)
 #ifdef CONFIG_X86
 #ifdef CONFIG_DYNAMIC_FTRACE
 BTF_ID(func, dctcp_init)
@@ -249,25 +249,27 @@ BTF_ID(func, dctcp_cwnd_undo)
 BTF_ID(func, dctcp_state)
 #endif
 #endif
-BTF_SET_END(tcp_dctcp_kfunc_ids)
+BTF_SET_END(tcp_dctcp_check_kfunc_ids)
 
-static DEFINE_KFUNC_BTF_ID_SET(&tcp_dctcp_kfunc_ids, tcp_dctcp_kfunc_btf_set);
+static const struct btf_kfunc_id_set tcp_dctcp_kfunc_set = {
+	.owner     = THIS_MODULE,
+	.check_set = &tcp_dctcp_check_kfunc_ids,
+};
 
 static int __init dctcp_register(void)
 {
 	int ret;
 
 	BUILD_BUG_ON(sizeof(struct dctcp) > ICSK_CA_PRIV_SIZE);
-	ret = tcp_register_congestion_control(&dctcp);
-	if (ret)
+
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &tcp_dctcp_kfunc_set);
+	if (ret < 0)
 		return ret;
-	register_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_dctcp_kfunc_btf_set);
-	return 0;
+	return tcp_register_congestion_control(&dctcp);
 }
 
 static void __exit dctcp_unregister(void)
 {
-	unregister_kfunc_btf_id_set(&bpf_tcp_ca_kfunc_list, &tcp_dctcp_kfunc_btf_set);
 	tcp_unregister_congestion_control(&dctcp);
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bfe4112e000c..2088f93fa37b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4684,10 +4684,16 @@ static bool tcp_ooo_try_coalesce(struct sock *sk,
 	return res;
 }
 
-static void tcp_drop(struct sock *sk, struct sk_buff *skb)
+static void tcp_drop_reason(struct sock *sk, struct sk_buff *skb,
+			    enum skb_drop_reason reason)
 {
 	sk_drops_add(sk, skb);
-	__kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
+}
+
+static void tcp_drop(struct sock *sk, struct sk_buff *skb)
+{
+	tcp_drop_reason(sk, skb, SKB_DROP_REASON_NOT_SPECIFIED);
 }
 
 /* This one checks to see if we can put data from the
@@ -4773,7 +4779,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP);
 		sk->sk_data_ready(sk);
-		tcp_drop(sk, skb);
+		tcp_drop_reason(sk, skb, SKB_DROP_REASON_PROTO_MEM);
 		return;
 	}
 
@@ -4836,7 +4842,8 @@ coalesce_done:
 				/* All the bits are present. Drop. */
 				NET_INC_STATS(sock_net(sk),
 					      LINUX_MIB_TCPOFOMERGE);
-				tcp_drop(sk, skb);
+				tcp_drop_reason(sk, skb,
+						SKB_DROP_REASON_TCP_OFOMERGE);
 				skb = NULL;
 				tcp_dsack_set(sk, seq, end_seq);
 				goto add_sack;
@@ -4855,7 +4862,8 @@ coalesce_done:
 						 TCP_SKB_CB(skb1)->end_seq);
 				NET_INC_STATS(sock_net(sk),
 					      LINUX_MIB_TCPOFOMERGE);
-				tcp_drop(sk, skb1);
+				tcp_drop_reason(sk, skb1,
+						SKB_DROP_REASON_TCP_OFOMERGE);
 				goto merge_right;
 			}
 		} else if (tcp_ooo_try_coalesce(sk, skb1,
@@ -4883,7 +4891,7 @@ merge_right:
 		tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
 				 TCP_SKB_CB(skb1)->end_seq);
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
-		tcp_drop(sk, skb1);
+		tcp_drop_reason(sk, skb1, SKB_DROP_REASON_TCP_OFOMERGE);
 	}
 	/* If there is no skb after us, we are the last_skb ! */
 	if (!skb1)
@@ -4982,6 +4990,7 @@ void tcp_data_ready(struct sock *sk)
 static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
+	enum skb_drop_reason reason;
 	bool fragstolen;
 	int eaten;
 
@@ -5000,6 +5009,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 	skb_dst_drop(skb);
 	__skb_pull(skb, tcp_hdr(skb)->doff * 4);
 
+	reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	tp->rx_opt.dsack = 0;
 
 	/*  Queue data for delivery to the user.
@@ -5008,6 +5018,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
 	 */
 	if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
 		if (tcp_receive_window(tp) == 0) {
+			reason = SKB_DROP_REASON_TCP_ZEROWINDOW;
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP);
 			goto out_of_window;
 		}
@@ -5017,6 +5028,7 @@ queue_and_out:
 		if (skb_queue_len(&sk->sk_receive_queue) == 0)
 			sk_forced_mem_schedule(sk, skb->truesize);
 		else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) {
+			reason = SKB_DROP_REASON_PROTO_MEM;
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP);
 			sk->sk_data_ready(sk);
 			goto drop;
@@ -5053,6 +5065,7 @@ queue_and_out:
 	if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
 		tcp_rcv_spurious_retrans(sk, skb);
 		/* A retransmit, 2nd most common case.  Force an immediate ack. */
+		reason = SKB_DROP_REASON_TCP_OLD_DATA;
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
 		tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
 
@@ -5060,13 +5073,16 @@ out_of_window:
 		tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
 		inet_csk_schedule_ack(sk);
 drop:
-		tcp_drop(sk, skb);
+		tcp_drop_reason(sk, skb, reason);
 		return;
 	}
 
 	/* Out of window. F.e. zero window probe. */
-	if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt + tcp_receive_window(tp)))
+	if (!before(TCP_SKB_CB(skb)->seq,
+		    tp->rcv_nxt + tcp_receive_window(tp))) {
+		reason = SKB_DROP_REASON_TCP_OVERWINDOW;
 		goto out_of_window;
+	}
 
 	if (before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
 		/* Partial packet, seq < rcv_next < end_seq */
@@ -5076,6 +5092,7 @@ drop:
 		 * remembering D-SACK for its head made in previous line.
 		 */
 		if (!tcp_receive_window(tp)) {
+			reason = SKB_DROP_REASON_TCP_ZEROWINDOW;
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP);
 			goto out_of_window;
 		}
@@ -5781,6 +5798,7 @@ discard:
  */
 void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	const struct tcphdr *th = (const struct tcphdr *)skb->data;
 	struct tcp_sock *tp = tcp_sk(sk);
 	unsigned int len = skb->len;
@@ -5869,6 +5887,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
 				tp->rcv_rtt_last_tsecr = tp->rx_opt.rcv_tsecr;
 				return;
 			} else { /* Header too small */
+				reason = SKB_DROP_REASON_PKT_TOO_SMALL;
 				TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
 				goto discard;
 			}
@@ -5924,8 +5943,10 @@ slow_path:
 	if (len < (th->doff << 2) || tcp_checksum_complete(skb))
 		goto csum_error;
 
-	if (!th->ack && !th->rst && !th->syn)
+	if (!th->ack && !th->rst && !th->syn) {
+		reason = SKB_DROP_REASON_TCP_FLAGS;
 		goto discard;
+	}
 
 	/*
 	 *	Standard slow path.
@@ -5951,12 +5972,13 @@ step5:
 	return;
 
 csum_error:
+	reason = SKB_DROP_REASON_TCP_CSUM;
 	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
 
 discard:
-	tcp_drop(sk, skb);
+	tcp_drop_reason(sk, skb, reason);
 }
 EXPORT_SYMBOL(tcp_rcv_established);
 
@@ -6703,7 +6725,8 @@ static void tcp_openreq_init(struct request_sock *req,
 	ireq->ir_num = ntohs(tcp_hdr(skb)->dest);
 	ireq->ir_mark = inet_request_mark(sk, skb);
 #if IS_ENABLED(CONFIG_SMC)
-	ireq->smc_ok = rx_opt->smc_ok;
+	ireq->smc_ok = rx_opt->smc_ok && !(tcp_sk(sk)->smc_hs_congested &&
+			tcp_sk(sk)->smc_hs_congested(sk));
 #endif
 }
 
@@ -6725,6 +6748,7 @@ struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
 		ireq->ireq_state = TCP_NEW_SYN_RECV;
 		write_pnet(&ireq->ireq_net, sock_net(sk_listener));
 		ireq->ireq_family = sk_listener->sk_family;
+		req->timeout = TCP_TIMEOUT_INIT;
 	}
 
 	return req;
@@ -6941,9 +6965,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
 		sock_put(fastopen_sk);
 	} else {
 		tcp_rsk(req)->tfo_listener = false;
-		if (!want_cookie)
-			inet_csk_reqsk_queue_hash_add(sk, req,
-				tcp_timeout_init((struct sock *)req));
+		if (!want_cookie) {
+			req->timeout = tcp_timeout_init((struct sock *)req);
+			inet_csk_reqsk_queue_hash_add(sk, req, req->timeout);
+		}
 		af_ops->send_synack(sk, dst, &fl, req, &foc,
 				    !want_cookie ? TCP_SYNACK_NORMAL :
 						   TCP_SYNACK_COOKIE,
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fec656f5a39e..f9cec624068d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -91,6 +91,8 @@ static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 struct inet_hashinfo tcp_hashinfo;
 EXPORT_SYMBOL(tcp_hashinfo);
 
+static DEFINE_PER_CPU(struct sock *, ipv4_tcp_sk);
+
 static u32 tcp_v4_init_seq(const struct sk_buff *skb)
 {
 	return secure_tcp_seq(ip_hdr(skb)->daddr,
@@ -206,7 +208,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct rtable *rt;
 	int err;
 	struct ip_options_rcu *inet_opt;
-	struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
+	struct inet_timewait_death_row *tcp_death_row = sock_net(sk)->ipv4.tcp_death_row;
 
 	if (addr_len < sizeof(struct sockaddr_in))
 		return -EINVAL;
@@ -810,7 +812,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	arg.tos = ip_hdr(skb)->tos;
 	arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
 	local_bh_disable();
-	ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
+	ctl_sk = this_cpu_read(ipv4_tcp_sk);
+	sock_net_set(ctl_sk, net);
 	if (sk) {
 		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
 				   inet_twsk(sk)->tw_mark : sk->sk_mark;
@@ -825,6 +828,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 			      transmit_time);
 
 	ctl_sk->sk_mark = 0;
+	sock_net_set(ctl_sk, &init_net);
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	__TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
 	local_bh_enable();
@@ -908,7 +912,8 @@ static void tcp_v4_send_ack(const struct sock *sk,
 	arg.tos = tos;
 	arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL);
 	local_bh_disable();
-	ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
+	ctl_sk = this_cpu_read(ipv4_tcp_sk);
+	sock_net_set(ctl_sk, net);
 	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) ?
@@ -921,6 +926,7 @@ static void tcp_v4_send_ack(const struct sock *sk,
 			      transmit_time);
 
 	ctl_sk->sk_mark = 0;
+	sock_net_set(ctl_sk, &init_net);
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	local_bh_enable();
 }
@@ -1403,72 +1409,6 @@ EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
 
 #endif
 
-/* Called with rcu_read_lock() */
-static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
-				    const struct sk_buff *skb,
-				    int dif, int sdif)
-{
-#ifdef CONFIG_TCP_MD5SIG
-	/*
-	 * This gets called for each TCP segment that arrives
-	 * so we want to be efficient.
-	 * 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 iphdr *iph = ip_hdr(skb);
-	const struct tcphdr *th = tcp_hdr(skb);
-	const union tcp_md5_addr *addr;
-	unsigned char newhash[16];
-	int genhash, l3index;
-
-	/* sdif set, means packet ingressed via a device
-	 * in an L3 domain and dif is set to the l3mdev
-	 */
-	l3index = sdif ? dif : 0;
-
-	addr = (union tcp_md5_addr *)&iph->saddr;
-	hash_expected = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
-	hash_location = tcp_parse_md5sig_option(th);
-
-	/* We've parsed the options - do we have a hash? */
-	if (!hash_expected && !hash_location)
-		return false;
-
-	if (hash_expected && !hash_location) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
-		return true;
-	}
-
-	if (!hash_expected && hash_location) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
-		return true;
-	}
-
-	/* Okay, so this is hash_expected and hash_location -
-	 * so we need to calculate the checksum.
-	 */
-	genhash = tcp_v4_md5_hash_skb(newhash,
-				      hash_expected,
-				      NULL, skb);
-
-	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
-		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
-		net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
-				     &iph->saddr, ntohs(th->source),
-				     &iph->daddr, ntohs(th->dest),
-				     genhash ? " tcp_v4_calc_md5_hash failed"
-				     : "", l3index);
-		return true;
-	}
-	return false;
-#endif
-	return false;
-}
-
 static void tcp_v4_init_req(struct request_sock *req,
 			    const struct sock *sk_listener,
 			    struct sk_buff *skb)
@@ -1698,6 +1638,7 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
  */
 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason;
 	struct sock *rsk;
 
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
@@ -1720,6 +1661,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
+	reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (tcp_checksum_complete(skb))
 		goto csum_err;
 
@@ -1747,7 +1689,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 reset:
 	tcp_v4_send_reset(rsk, skb);
 discard:
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 	/* Be careful here. If this function gets more complicated and
 	 * gcc suffers from register pressure on the x86, sk (in %ebx)
 	 * might be destroyed here. This current version compiles correctly,
@@ -1756,6 +1698,7 @@ discard:
 	return 0;
 
 csum_err:
+	reason = SKB_DROP_REASON_TCP_CSUM;
 	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
@@ -1801,7 +1744,8 @@ int tcp_v4_early_demux(struct sk_buff *skb)
 	return 0;
 }
 
-bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
+bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb,
+		     enum skb_drop_reason *reason)
 {
 	u32 limit, tail_gso_size, tail_gso_segs;
 	struct skb_shared_info *shinfo;
@@ -1827,6 +1771,7 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(tcp_checksum_complete(skb))) {
 		bh_unlock_sock(sk);
 		trace_tcp_bad_csum(skb);
+		*reason = SKB_DROP_REASON_TCP_CSUM;
 		__TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 		__TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
 		return true;
@@ -1915,6 +1860,7 @@ no_coalesce:
 
 	if (unlikely(sk_add_backlog(sk, skb, limit))) {
 		bh_unlock_sock(sk);
+		*reason = SKB_DROP_REASON_SOCKET_BACKLOG;
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP);
 		return true;
 	}
@@ -1965,13 +1911,13 @@ static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph,
 int tcp_v4_rcv(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
+	enum skb_drop_reason drop_reason;
 	int sdif = inet_sdif(skb);
 	int dif = inet_iif(skb);
 	const struct iphdr *iph;
 	const struct tcphdr *th;
 	bool refcounted;
 	struct sock *sk;
-	int drop_reason;
 	int ret;
 
 	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
@@ -2019,7 +1965,10 @@ process:
 		struct sock *nsk;
 
 		sk = req->rsk_listener;
-		if (unlikely(tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))) {
+		drop_reason = tcp_inbound_md5_hash(sk, skb,
+						   &iph->saddr, &iph->daddr,
+						   AF_INET, dif, sdif);
+		if (unlikely(drop_reason)) {
 			sk_drops_add(sk, skb);
 			reqsk_put(req);
 			goto discard_it;
@@ -2051,6 +2000,8 @@ process:
 			iph = ip_hdr(skb);
 			tcp_v4_fill_cb(skb, iph, th);
 			nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+		} else {
+			drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
 		}
 		if (!nsk) {
 			reqsk_put(req);
@@ -2086,10 +2037,14 @@ process:
 		}
 	}
 
-	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		goto discard_and_relse;
+	}
 
-	if (tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))
+	drop_reason = tcp_inbound_md5_hash(sk, skb, &iph->saddr,
+					   &iph->daddr, AF_INET, dif, sdif);
+	if (drop_reason)
 		goto discard_and_relse;
 
 	nf_reset_ct(skb);
@@ -2118,7 +2073,7 @@ process:
 	if (!sock_owned_by_user(sk)) {
 		ret = tcp_v4_do_rcv(sk, skb);
 	} else {
-		if (tcp_add_backlog(sk, skb))
+		if (tcp_add_backlog(sk, skb, &drop_reason))
 			goto discard_and_relse;
 	}
 	bh_unlock_sock(sk);
@@ -2160,6 +2115,7 @@ discard_and_relse:
 
 do_time_wait:
 	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		inet_twsk_put(inet_twsk(sk));
 		goto discard_it;
 	}
@@ -3111,41 +3067,18 @@ EXPORT_SYMBOL(tcp_prot);
 
 static void __net_exit tcp_sk_exit(struct net *net)
 {
-	int cpu;
+	struct inet_timewait_death_row *tcp_death_row = net->ipv4.tcp_death_row;
 
 	if (net->ipv4.tcp_congestion_control)
 		bpf_module_put(net->ipv4.tcp_congestion_control,
 			       net->ipv4.tcp_congestion_control->owner);
-
-	for_each_possible_cpu(cpu)
-		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu));
-	free_percpu(net->ipv4.tcp_sk);
+	if (refcount_dec_and_test(&tcp_death_row->tw_refcount))
+		kfree(tcp_death_row);
 }
 
 static int __net_init tcp_sk_init(struct net *net)
 {
-	int res, cpu, cnt;
-
-	net->ipv4.tcp_sk = alloc_percpu(struct sock *);
-	if (!net->ipv4.tcp_sk)
-		return -ENOMEM;
-
-	for_each_possible_cpu(cpu) {
-		struct sock *sk;
-
-		res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW,
-					   IPPROTO_TCP, net);
-		if (res)
-			goto fail;
-		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
-
-		/* Please enforce IP_DF and IPID==0 for RST and
-		 * ACK sent in SYN-RECV and TIME-WAIT state.
-		 */
-		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO;
-
-		*per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;
-	}
+	int cnt;
 
 	net->ipv4.sysctl_tcp_ecn = 2;
 	net->ipv4.sysctl_tcp_ecn_fallback = 1;
@@ -3172,9 +3105,13 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_tw_reuse = 2;
 	net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1;
 
+	net->ipv4.tcp_death_row = kzalloc(sizeof(struct inet_timewait_death_row), GFP_KERNEL);
+	if (!net->ipv4.tcp_death_row)
+		return -ENOMEM;
+	refcount_set(&net->ipv4.tcp_death_row->tw_refcount, 1);
 	cnt = tcp_hashinfo.ehash_mask + 1;
-	net->ipv4.tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
-	net->ipv4.tcp_death_row.hashinfo = &tcp_hashinfo;
+	net->ipv4.tcp_death_row->sysctl_max_tw_buckets = cnt / 2;
+	net->ipv4.tcp_death_row->hashinfo = &tcp_hashinfo;
 
 	net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 128);
 	net->ipv4.sysctl_tcp_sack = 1;
@@ -3200,6 +3137,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	/* rfc5961 challenge ack rate limiting */
 	net->ipv4.sysctl_tcp_challenge_ack_limit = 1000;
 	net->ipv4.sysctl_tcp_min_tso_segs = 2;
+	net->ipv4.sysctl_tcp_tso_rtt_log = 9;  /* 2^9 = 512 usec */
 	net->ipv4.sysctl_tcp_min_rtt_wlen = 300;
 	net->ipv4.sysctl_tcp_autocorking = 1;
 	net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2;
@@ -3229,18 +3167,12 @@ static int __net_init tcp_sk_init(struct net *net)
 		net->ipv4.tcp_congestion_control = &tcp_reno;
 
 	return 0;
-fail:
-	tcp_sk_exit(net);
-
-	return res;
 }
 
 static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
 {
 	struct net *net;
 
-	inet_twsk_purge(&tcp_hashinfo, AF_INET);
-
 	list_for_each_entry(net, net_exit_list, exit_list)
 		tcp_fastopen_ctx_destroy(net);
 }
@@ -3326,6 +3258,24 @@ static void __init bpf_iter_register(void)
 
 void __init tcp_v4_init(void)
 {
+	int cpu, res;
+
+	for_each_possible_cpu(cpu) {
+		struct sock *sk;
+
+		res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW,
+					   IPPROTO_TCP, &init_net);
+		if (res)
+			panic("Failed to create the TCP control socket.\n");
+		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+		/* Please enforce IP_DF and IPID==0 for RST and
+		 * ACK sent in SYN-RECV and TIME-WAIT state.
+		 */
+		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO;
+
+		per_cpu(ipv4_tcp_sk, cpu) = sk;
+	}
 	if (register_pernet_subsys(&tcp_sk_ops))
 		panic("Failed to create the TCP control socket.\n");
 
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 7c2d3ac2363a..6366df7aaf2a 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -248,7 +248,7 @@ 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 inet_timewait_sock *tw;
-	struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
+	struct inet_timewait_death_row *tcp_death_row = sock_net(sk)->ipv4.tcp_death_row;
 
 	tw = inet_twsk_alloc(sk, tcp_death_row, state);
 
@@ -583,7 +583,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 			 * it can be estimated (approximately)
 			 * from another data.
 			 */
-			tmp_opt.ts_recent_stamp = ktime_get_seconds() - ((TCP_TIMEOUT_INIT/HZ)<<req->num_timeout);
+			tmp_opt.ts_recent_stamp = ktime_get_seconds() - reqsk_timeout(req, TCP_RTO_MAX) / HZ;
 			paws_reject = tcp_paws_reject(&tmp_opt, th->rst);
 		}
 	}
@@ -622,8 +622,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 		    !inet_rtx_syn_ack(sk, req)) {
 			unsigned long expires = jiffies;
 
-			expires += min(TCP_TIMEOUT_INIT << req->num_timeout,
-				       TCP_RTO_MAX);
+			expires += reqsk_timeout(req, TCP_RTO_MAX);
 			if (!fastopen)
 				mod_timer_pending(&req->rsk_timer, expires);
 			else
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5079832af5c1..9ede847f4199 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1253,7 +1253,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	tp = tcp_sk(sk);
 	prior_wstamp = tp->tcp_wstamp_ns;
 	tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache);
-	skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
+	skb_set_delivery_time(skb, tp->tcp_wstamp_ns, true);
 	if (clone_it) {
 		oskb = skb;
 
@@ -1589,7 +1589,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 
 	skb_split(skb, buff, len);
 
-	buff->tstamp = skb->tstamp;
+	skb_set_delivery_time(buff, skb->tstamp, true);
 	tcp_fragment_tstamp(skb, buff);
 
 	old_factor = tcp_skb_pcount(skb);
@@ -1951,25 +1951,34 @@ static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp,
 }
 
 /* Return how many segs we'd like on a TSO packet,
- * to send one TSO packet per ms
+ * depending on current pacing rate, and how close the peer is.
+ *
+ * Rationale is:
+ * - For close peers, we rather send bigger packets to reduce
+ *   cpu costs, because occasional losses will be repaired fast.
+ * - For long distance/rtt flows, we would like to get ACK clocking
+ *   with 1 ACK per ms.
+ *
+ * Use min_rtt to help adapt TSO burst size, with smaller min_rtt resulting
+ * in bigger TSO bursts. We we cut the RTT-based allowance in half
+ * for every 2^9 usec (aka 512 us) of RTT, so that the RTT-based allowance
+ * is below 1500 bytes after 6 * ~500 usec = 3ms.
  */
 static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
 			    int min_tso_segs)
 {
-	u32 bytes, segs;
+	unsigned long bytes;
+	u32 r;
 
-	bytes = min_t(unsigned long,
-		      sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift),
-		      sk->sk_gso_max_size - 1 - MAX_TCP_HEADER);
+	bytes = sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift);
 
-	/* Goal is to send at least one packet per ms,
-	 * not one big TSO packet every 100 ms.
-	 * This preserves ACK clocking and is consistent
-	 * with tcp_tso_should_defer() heuristic.
-	 */
-	segs = max_t(u32, bytes / mss_now, min_tso_segs);
+	r = tcp_min_rtt(tcp_sk(sk)) >> sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log;
+	if (r < BITS_PER_TYPE(sk->sk_gso_max_size))
+		bytes += sk->sk_gso_max_size >> r;
 
-	return segs;
+	bytes = min_t(unsigned long, bytes, sk->sk_gso_max_size);
+
+	return max_t(u32, bytes / mss_now, min_tso_segs);
 }
 
 /* Return the number of segments we want in the skb we are transmitting.
@@ -2616,7 +2625,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 
 		if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) {
 			/* "skb_mstamp_ns" is used as a start point for the retransmit timer */
-			skb->skb_mstamp_ns = tp->tcp_wstamp_ns = tp->tcp_clock_cache;
+			tp->tcp_wstamp_ns = tp->tcp_clock_cache;
+			skb_set_delivery_time(skb, tp->tcp_wstamp_ns, true);
 			list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue);
 			tcp_init_tso_segs(skb, mss_now);
 			goto repair; /* Skip network transmission */
@@ -3541,11 +3551,12 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 	now = tcp_clock_ns();
 #ifdef CONFIG_SYN_COOKIES
 	if (unlikely(synack_type == TCP_SYNACK_COOKIE && ireq->tstamp_ok))
-		skb->skb_mstamp_ns = cookie_init_timestamp(req, now);
+		skb_set_delivery_time(skb, cookie_init_timestamp(req, now),
+				      true);
 	else
 #endif
 	{
-		skb->skb_mstamp_ns = now;
+		skb_set_delivery_time(skb, now, true);
 		if (!tcp_rsk(req)->snt_synack) /* Timestamp first SYNACK */
 			tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb);
 	}
@@ -3594,7 +3605,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 	bpf_skops_write_hdr_opt((struct sock *)sk, skb, req, syn_skb,
 				synack_type, &opts);
 
-	skb->skb_mstamp_ns = now;
+	skb_set_delivery_time(skb, now, true);
 	tcp_add_tx_delay(skb, tp);
 
 	return skb;
@@ -3719,6 +3730,7 @@ static void tcp_connect_queue_skb(struct sock *sk, struct sk_buff *skb)
  */
 static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_fastopen_request *fo = tp->fastopen_req;
 	int space, err = 0;
@@ -3733,8 +3745,10 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 	 * private TCP options. The cost is reduced data space in SYN :(
 	 */
 	tp->rx_opt.mss_clamp = tcp_mss_clamp(tp, tp->rx_opt.mss_clamp);
+	/* Sync mss_cache after updating the mss_clamp */
+	tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 
-	space = __tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
+	space = __tcp_mtu_to_mss(sk, icsk->icsk_pmtu_cookie) -
 		MAX_TCP_OPTION_SPACE;
 
 	space = min_t(size_t, space, fo->size);
@@ -3771,7 +3785,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 
 	err = tcp_transmit_skb(sk, syn_data, 1, sk->sk_allocation);
 
-	syn->skb_mstamp_ns = syn_data->skb_mstamp_ns;
+	skb_set_delivery_time(syn, syn_data->skb_mstamp_ns, true);
 
 	/* Now full SYN+DATA was cloned and sent (or not),
 	 * remove the SYN from the original skb (syn_data)
@@ -4092,7 +4106,9 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req)
 	struct flowi fl;
 	int res;
 
-	tcp_rsk(req)->txhash = net_tx_rndhash();
+	/* Paired with WRITE_ONCE() in sock_setsockopt() */
+	if (READ_ONCE(sk->sk_txrehash) == SOCK_TXREHASH_ENABLED)
+		tcp_rsk(req)->txhash = net_tx_rndhash();
 	res = af_ops->send_synack(sk, NULL, &fl, req, NULL, TCP_SYNACK_NORMAL,
 				  NULL);
 	if (!res) {
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 090360939401..6b4d8361560f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2093,16 +2093,20 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	rc = __udp_enqueue_schedule_skb(sk, skb);
 	if (rc < 0) {
 		int is_udplite = IS_UDPLITE(sk);
+		int drop_reason;
 
 		/* Note that an ENOMEM error is charged twice */
-		if (rc == -ENOMEM)
+		if (rc == -ENOMEM) {
 			UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
 					is_udplite);
-		else
+			drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
+		} else {
 			UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
 				      is_udplite);
+			drop_reason = SKB_DROP_REASON_PROTO_MEM;
+		}
 		UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
-		kfree_skb(skb);
+		kfree_skb_reason(skb, drop_reason);
 		trace_udp_fail_queue_rcv_skb(rc, sk);
 		return -1;
 	}
@@ -2120,14 +2124,17 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
  */
 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 {
+	int drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	struct udp_sock *up = udp_sk(sk);
 	int is_udplite = IS_UDPLITE(sk);
 
 	/*
 	 *	Charge it to the socket, dropping if the queue is full.
 	 */
-	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 		goto drop;
+	}
 	nf_reset_ct(skb);
 
 	if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
@@ -2204,8 +2211,10 @@ static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 	    udp_lib_checksum_complete(skb))
 			goto csum_error;
 
-	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
+	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
+		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
 		goto drop;
+	}
 
 	udp_csum_pull_header(skb);
 
@@ -2213,11 +2222,12 @@ static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 	return __udp_queue_rcv_skb(sk, skb);
 
 csum_error:
+	drop_reason = SKB_DROP_REASON_UDP_CSUM;
 	__UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 drop:
 	__UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 	atomic_inc(&sk->sk_drops);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, drop_reason);
 	return -1;
 }
 
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 9e83bcb6bc99..6fde0b184791 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -28,13 +28,11 @@ static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4,
 	memset(fl4, 0, sizeof(*fl4));
 	fl4->daddr = daddr->a4;
 	fl4->flowi4_tos = tos;
-	fl4->flowi4_oif = l3mdev_master_ifindex_by_index(net, oif);
+	fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(net, oif);
 	fl4->flowi4_mark = mark;
 	if (saddr)
 		fl4->saddr = saddr->a4;
 
-	fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF;
-
 	rt = __ip_route_output_key(net, fl4);
 	if (!IS_ERR(rt))
 		return &rt->dst;