Stewart Smith ecb741a17c tcp: Reduce chance of collisions in inet6_hashfn(). ... [ Upstream commit d11b0df7dd ] For both IPv4 and IPv6 incoming TCP connections are tracked in a hash table with a hash over the source & destination addresses and ports. However, the IPv6 hash is insufficient and can lead to a high rate of collisions. The IPv6 hash used an XOR to fit everything into the 96 bits for the fast jenkins hash, meaning it is possible for an external entity to ensure the hash collides, thus falling back to a linear search in the bucket, which is slow. We take the approach of hash the full length of IPv6 address in __ipv6_addr_jhash() so that all users can benefit from a more secure version. While this may look like it adds overhead, the reality of modern CPUs means that this is unmeasurable in real world scenarios. In simulating with llvm-mca, the increase in cycles for the hashing code was ~16 cycles on Skylake (from a base of ~155), and an extra ~9 on Nehalem (base of ~173). In commit dd6d2910c5 ("netfilter: conntrack: switch to siphash") netfilter switched from a jenkins hash to a siphash, but even the faster hsiphash is a more significant overhead (~20-30%) in some preliminary testing. So, in this patch, we keep to the more conservative approach to ensure we don't add much overhead per SYN. In testing, this results in a consistently even spread across the connection buckets. In both testing and real-world scenarios, we have not found any measurable performance impact. Fixes: 08dcdbf6a7 ("ipv6: use a stronger hash for tcp") Signed-off-by: Stewart Smith <trawets@amazon.com> Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230721222410.17914-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-08-03 10:22:34 +02:00
..
9p	9p: Add client parameter to p9_req_put()	2022-08-17 14:24:07 +02:00
bluetooth	Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put	2022-08-03 12:03:40 +02:00
caif	net: remove the caif_hsi driver	2021-07-01 13:19:48 -07:00
iucv	net/af_iucv: don't track individual TX skbs for TRANS_HIPER sockets	2021-01-28 20:36:21 -08:00
netfilter	netfilter: nf_tables: drop map element references from preparation phase	2023-07-23 13:46:44 +02:00
netns	Remove DECnet support from kernel	2023-06-21 15:59:15 +02:00
nfc	NFC: add NCI_UNREG flag to eliminate the race	2021-11-25 09:48:40 +01:00
phonet
sctp	sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop	2023-03-11 13:57:28 +01:00
tc_act	net/sched: transition act_pedit to rcu and percpu stats	2023-03-11 13:57:29 +01:00
6lowpan.h	6lowpan: Replace zero-length array with flexible-array member	2020-02-28 14:51:30 +01:00
act_api.h	net_sched: refactor TC action init API	2021-08-02 10:24:38 +01:00
addrconf.h	ipv6/addrconf: fix a null-ptr-deref bug for ip6_ptr	2022-08-03 12:03:47 +02:00
af_ieee802154.h
af_rxrpc.h	afs: Don't truncate iter during data fetch	2021-04-23 10:17:26 +01:00
af_unix.h	af_unix: Add unix_stream_proto for sockmap	2021-08-16 18:43:39 -07:00
af_vsock.h	vsock: each transport cycles only on its own sockets	2022-03-23 09:16:41 +01:00
ah.h
arp.h	ipv4: Invalidate neighbour for broadcast address upon address addition	2022-04-13 20:59:05 +02:00
atmclip.h
ax25.h	ax25: fix reference count leaks of ax25_dev	2022-04-20 09:34:22 +02:00
ax88796.h	ax88796: export ax_NS8390_init() hook	2021-08-03 13:05:25 +01:00
bareudp.h	bareudp: Reverted support to enable & disable rx metadata collection	2020-07-21 18:30:47 -07:00
bond_3ad.h	net: bonding: Share lacpdu_mcast_addr definition	2022-09-28 11:11:48 +02:00
bond_alb.h	bonding (gcc13): synchronize bond_{a,t}lb_xmit() types	2023-06-14 11:13:00 +02:00
bond_options.h	Bonding: add arp_missed_max option	2023-06-05 09:21:19 +02:00
bonding.h	bonding: fix send_peer_notif overflow	2023-06-05 09:21:19 +02:00
bpf_sk_storage.h	bpf: struct sock is declared twice in bpf_sk_storage header	2021-03-26 17:43:55 +01:00
busy_poll.h	net: Fix a data-race around sysctl_net_busy_poll.	2022-08-31 17:16:43 +02:00
calipso.h
cfg80211-wext.h
cfg80211.h	cfg80211: fix management registrations locking	2021-10-25 15:20:22 +02:00
cfg802154.h	cfg802154: Replace zero-length array with flexible-array member	2020-02-29 14:39:08 +01:00
checksum.h	net: Force inlining of checksum functions in net/checksum.h	2022-03-02 11:47:58 +01:00
cipso_ipv4.h	cipso: Remove unused inline functions	2020-07-15 07:45:24 -07:00
cls_cgroup.h	bpf: Allow to retrieve cgroup v1 classid from v2 hooks	2020-03-27 19:40:38 -07:00
codel.h
codel_impl.h
codel_qdisc.h
compat.h	net/ipv4/ipv6: Replace one-element arraya with flexible-array members	2021-08-05 11:46:42 +01:00
datalink.h
dcbevent.h
dcbnl.h
devlink.h	devlink: Use xarray to store devlink instances	2021-08-14 13:59:10 +01:00
dsa.h	net: dsa: introduce helpers for iterating through ports using dp	2023-06-05 09:21:17 +02:00
dsfield.h	ipv6: Annotate bitwise IPv6 dsfield pointer cast	2019-12-16 16:09:44 -08:00
dst.h	net: Remove unused inline function dst_hold_and_use()	2023-06-21 15:59:19 +02:00
dst_cache.h	wireguard: device: reset peer src endpoint when netns exits	2021-12-08 09:04:46 +01:00
dst_metadata.h	net: fix a memleak when uncloning an skb dst and its metadata	2022-02-16 12:56:30 +01:00
dst_ops.h	net/dst: use a smaller percpu_counter batch for dst entries accounting	2020-05-08 21:33:33 -07:00
erspan.h	erspan: Add type I version 0 support.	2020-05-05 13:23:29 -07:00
esp.h	esp: limit skb_page_frag_refill use to a single page	2022-04-27 14:38:52 +02:00
espintcp.h	xfrm: espintcp: save and call old ->sk_destruct	2020-04-20 07:34:16 +02:00
ethoc.h
failover.h
fib_notifier.h	ipv6: Remove old route notifications and convert listeners	2019-12-24 22:37:30 -08:00
fib_rules.h	ipv6: fix memory leak in fib6_rule_suppress	2021-12-08 09:04:43 +01:00
firewire.h
flow.h	net: Remove DECnet leftovers from flow.h.	2023-06-21 15:59:19 +02:00
flow_dissector.h	net/sched: flower: fix parsing of ethertype following VLAN header	2022-04-20 09:34:09 +02:00
flow_offload.h	netfilter: nf_tables: bail out early if hardware offload is not supported	2022-06-14 18:36:17 +02:00
fou.h
fq.h	net/fq_impl: do not maintain a backlog-sorted list of flows	2021-01-21 13:33:45 +01:00
fq_impl.h	net/fq_impl: do not maintain a backlog-sorted list of flows	2021-01-21 13:33:45 +01:00
garp.h	treewide: Use sizeof_field() macro	2019-12-09 10:36:44 -08:00
gen_stats.h	net_sched: extend packet counter to 64bit	2019-11-05 18:20:55 -08:00
genetlink.h	mptcp: avoid lock_fast usage in accept path	2021-02-12 16:31:46 -08:00
geneve.h
gre.h	ip_gre: add csum offload support for gre header	2021-01-29 20:39:14 -08:00
gro.h	gro: add combined call_gro_receive() + INDIRECT_CALL_INET() helper	2021-03-18 19:51:12 -07:00
gro_cells.h
gtp.h
gue.h	GUE: Fix a typo	2020-06-22 21:12:44 -07:00
hwbm.h	net: hwbm: if CONFIG_NET_HWBM unset, make stub functions static	2019-10-25 16:24:32 -07:00
icmp.h	ipv6: ICMPV6: add response to ICMPV6 RFC 8335 PROBE messages	2021-06-28 14:29:45 -07:00
ieee80211_radiotap.h	mac80211: Use flex-array for radiotap header bitmap	2021-08-13 09:58:25 +02:00
ieee802154_netdev.h	net: ieee802154: return -EINVAL for unknown addr type	2022-10-26 12:35:54 +02:00
if_inet6.h	ipv6: fix locking issues with loops over idev->addr_list	2022-06-09 10:22:31 +02:00
ife.h
ila.h
inet6_connection_sock.h
inet6_hashtables.h	net: allow unbound socket for packets in VRF when tcp_l3mdev_accept set	2022-08-17 14:23:36 +02:00
inet_common.h	bpf: Allow rewriting to ports under ip_unprivileged_port_start	2021-01-27 18:18:15 -08:00
inet_connection_sock.h	Revert "tcp: change pingpong threshold to 3"	2022-08-03 12:03:45 +02:00
inet_ecn.h	inet_ecn: Use csum16_add() helper for IP_ECN_set_* helpers	2020-12-14 18:38:58 -08:00
inet_frag.h	inet: frags: annotate races around fqdir->dead and fqdir->high_thresh	2022-01-27 11:05:35 +01:00
inet_hashtables.h	net: allow unbound socket for packets in VRF when tcp_l3mdev_accept set	2022-08-17 14:23:36 +02:00
inet_sock.h	net: allow unbound socket for packets in VRF when tcp_l3mdev_accept set	2022-08-17 14:23:36 +02:00
inet_timewait_sock.h
inetpeer.h
ioam6.h	ipv6: ioam: Support for IOAM injection with lwtunnels	2021-07-21 08:14:33 -07:00
ip.h	ipv{4,6}/raw: fix output xfrm lookup wrt protocol	2023-06-05 09:21:26 +02:00
ip6_checksum.h	tcp: remove indirect calls for icsk->icsk_af_ops->send_check	2020-06-20 17:47:53 -07:00
ip6_fib.h	ipv6: fix data-race in fib6_info_hw_flags_set / fib6_purge_rt	2022-02-23 12:03:10 +01:00
ip6_route.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2021-08-05 15:08:47 -07:00
ip6_tunnel.h	ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md mode	2022-05-09 09:14:36 +02:00
ip_fib.h	ipv4: convert fib_num_tclassid_users to atomic_t	2021-12-08 09:04:49 +01:00
ip_tunnels.h	ip_tunnels: allow VXLAN/GENEVE to inherit TOS/TTL from VLAN	2023-06-28 10:29:44 +02:00
ip_vs.h	ipvs: Update width of source for ip_vs_sync_conn_options	2023-05-24 17:36:46 +01:00
ipcomp.h
ipconfig.h
ipv6.h	tcp: Reduce chance of collisions in inet6_hashfn().	2023-08-03 10:22:34 +02:00
ipv6_frag.h	inet: frags: annotate races around fqdir->dead and fqdir->high_thresh	2022-01-27 11:05:35 +01:00
ipv6_stubs.h	net: ipv6: add fib6_nh_release_dsts stub	2021-12-01 09:04:49 +01:00
iw_handler.h
kcm.h
l3mdev.h	l3mdev: add infrastructure for table to VRF mapping	2020-06-20 17:22:22 -07:00
lag.h
lapb.h	net: lapb: Make "lapb_t1timer_running" able to detect an already running timer	2021-03-23 14:14:50 -07:00
lib80211.h
llc.h	llc: fix out-of-bound array index in llc_sk_dev_hash()	2021-11-18 19:17:10 +01:00
llc_c_ac.h
llc_c_ev.h
llc_c_st.h
llc_conn.h
llc_if.h
llc_pdu.h	net: llc: fix skb_over_panic	2021-07-27 13:05:56 +01:00
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
lwtunnel.h	netfilter: add netfilter hooks to SRv6 data plane	2021-08-30 01:51:36 +02:00
mac80211.h	mac80211: Fix Ptk0 rekey documentation	2021-09-27 12:02:54 +02:00
mac802154.h
macsec.h	net: macsec: fix the length used to copy the key for offloading	2021-06-24 12:41:12 -07:00
mctp.h	mctp: unify sockaddr_mctp types	2021-10-18 13:47:09 +01:00
mctpdevice.h	mctp: Remove the repeated declaration	2021-08-25 11:23:14 +01:00
mip6.h	net: mip6: Replace zero-length array with flexible-array member	2020-03-02 11:16:27 -08:00
mld.h	mld: add new workqueues for process mld events	2021-03-26 15:14:56 -07:00
mpls.h	net: Make mpls_entry_encode() available for generic users	2020-05-29 21:20:20 -07:00
mpls_iptunnel.h	net: mpls: Replace zero-length array with flexible-array member	2020-02-28 12:08:37 -08:00
mptcp.h	mptcp: remove MPTCP 'ifdef' in TCP SYN cookies	2023-01-12 11:58:52 +01:00
mrp.h	mrp: introduce active flags to prevent UAF when applicant uninit	2022-12-31 13:14:42 +01:00
ncsi.h
ndisc.h	ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()	2022-03-08 19:12:33 +01:00
neighbour.h	neighbour: delete neigh_lookup_nodev as not used	2023-06-21 15:59:19 +02:00
net_failover.h
net_namespace.h	net: initialize init_net earlier	2022-04-13 20:59:03 +02:00
net_ratelimit.h
netevent.h
netlabel.h
netlink.h	net: netlink: add the case when nlh is NULL	2021-07-27 11:43:50 +01:00
netprio_cgroup.h	netprio: use css ID instead of cgroup ID	2019-11-12 08:18:03 -08:00
netrom.h
nexthop.h	net: ipv4: Fix rtnexthop len when RTA_FLOW is present	2021-09-24 14:07:10 +01:00
nl802154.h	net: ieee802154: handle iftypes as u32	2021-12-01 09:04:46 +01:00
nsh.h
p8022.h
page_pool.h	page_pool: fix inconsistency for page_pool_ring_[un]lock()	2023-06-05 09:21:22 +02:00
pie.h	pie: realign comment	2020-03-04 13:25:55 -08:00
ping.h
pkt_cls.h	sch_htb: Fix inconsistency when leaf qdisc creation fails	2021-08-30 16:33:59 -07:00
pkt_sched.h	net/sched: make psched_mtu() RTNL-less safe	2023-07-23 13:47:45 +02:00
pptp.h
protocol.h	tcp/udp: Make early_demux back namespacified.	2022-11-10 18:15:38 +01:00
psample.h	psample: Add a fwd declaration for skbuff	2021-08-09 15:34:21 -07:00
psnap.h
raw.h	raw: Fix a data-race around sysctl_raw_l3mdev_accept.	2022-07-21 21:24:27 +02:00
rawv6.h
red.h	sch_red: fix off-by-one checks in red_check_params()	2021-03-25 17:40:43 -07:00
regulatory.h	net/wireless: regulatory.h: drop duplicate word in comment	2020-07-31 09:24:23 +02:00
request_sock.h	tcp: bpf: Optionally store mac header in TCP_SAVE_SYN	2020-08-24 14:35:00 -07:00
rose.h
route.h	ip: Fix data-races around sysctl_ip_default_ttl.	2022-07-29 17:25:09 +02:00
rpl.h	ipv6: rpl: Fix Route of Death.	2023-06-14 11:13:02 +02:00
rsi_91x.h
rtnetlink.h	net: add extack arg for link ops	2021-08-04 10:01:26 +01:00
rtnh.h
sch_generic.h	net/sched: sch_taprio: fix possible use-after-free	2023-02-01 08:27:09 +01:00
scm.h	scm: fix MSG_CTRUNC setting condition for SO_PASSSEC	2023-05-11 23:00:26 +09:00
secure_seq.h	secure_seq: use the 64 bits of the siphash for port offset calculation	2022-05-18 10:26:53 +02:00
seg6.h	udp6: Use Segment Routing Header for dest address if present	2022-01-27 11:05:05 +01:00
seg6_hmac.h
seg6_local.h
selftests.h	net: selftest: fix build issue if INET is disabled	2021-04-28 14:06:45 -07:00
slhc_vj.h
smc.h	net/smc: introduce CHID callback for ISM devices	2020-09-28 15:19:03 -07:00
snmp.h
sock.h	netlink: Add __sock_i_ino() for __netlink_diag_dump().	2023-07-23 13:46:56 +02:00
sock_reuseport.h	soreuseport: Fix socket selection for SO_INCOMING_CPU.	2022-12-31 13:14:07 +01:00
Space.h	wan: remove sbni/granch driver	2021-08-03 13:05:26 +01:00
stp.h
strparser.h	bpf, sockmap: sk_skb data_end access incorrect when src_reg = dst_reg	2021-11-18 19:17:11 +01:00
switchdev.h	net: make switchdev_bridge_port_{,unoffload} loosely coupled with the bridge	2021-08-04 12:35:07 +01:00
tcp.h	tcp: annotate data-races around tp->notsent_lowat	2023-07-27 08:47:04 +02:00
tcp_states.h
timewait_sock.h
tipc.h
tls.h	net/tls: Check for errors in tls_device_init	2022-07-21 21:24:31 +02:00
tls_toe.h
transp_v6.h	tcp: move ipv4_specific to tcp include file	2020-06-23 20:10:15 -07:00
tso.h	net: tso: cache transport header length	2020-06-18 20:46:23 -07:00
tun_proto.h
udp.h	tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().	2023-04-26 13:51:54 +02:00
udp_tunnel.h	rxrpc: Fix ICMP/ICMP6 error handling	2022-09-15 11:30:05 +02:00
udplite.h	tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().	2023-04-26 13:51:54 +02:00
vsock_addr.h	vsock: remove include/linux/vm_sockets.h file	2019-11-14 18:12:17 -08:00
vxlan.h	vxlan: calculate correct header length for GPE	2023-08-03 10:22:34 +02:00
wext.h
x25.h	net/x25: add new state X25_STATE_5	2019-12-09 10:28:43 -08:00
x25device.h
xdp.h	xdp: Allow registering memory model without rxq reference	2023-06-05 09:21:21 +02:00
xdp_priv.h	page_pool: do not release pool until inflight == 0.	2019-11-16 12:39:10 -08:00
xdp_sock.h	xdp: Add proper __rcu annotations to redirect map entries	2021-06-24 19:41:15 +02:00
xdp_sock_drv.h	i40e: xsk: Move tmp desc array from driver to pool	2022-06-14 18:36:18 +02:00
xfrm.h	xfrm: Treat already-verified secpath entries as optional	2023-06-28 10:29:45 +02:00
xsk_buff_pool.h	xsk: Fix unaligned descriptor validation	2023-05-11 23:00:27 +09:00