linux/net/ipv6
Eric Dumazet 614e8316aa tcp: add support for usec resolution in TCP TS values
Back in 2015, Van Jacobson suggested to use usec resolution in TCP TS values.
This has been implemented in our private kernels.

Goals were :

1) better observability of delays in networking stacks.
2) better disambiguation of events based on TSval/ecr values.
3) building block for congestion control modules needing usec resolution.

Back then we implemented a schem based on private SYN options
to negotiate the feature.

For upstream submission, we chose to use a route attribute,
because this feature is probably going to be used in private
networks [1] [2].

ip route add 10/8 ... features tcp_usec_ts

Note that RFC 7323 recommends a
  "timestamp clock frequency in the range 1 ms to 1 sec per tick.",
but also mentions
  "the maximum acceptable clock frequency is one tick every 59 ns."

[1] Unfortunately RFC 7323 5.5 (Outdated Timestamps) suggests
to invalidate TS.Recent values after a flow was idle for more
than 24 days. This is the part making usec_ts a problem
for peers following this recommendation for long living
idle flows.

[2] Attempts to standardize usec ts went nowhere:

https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf
https://datatracker.ietf.org/doc/draft-wang-tcpm-low-latency-opt/

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23 09:35:01 +01:00
..
ila ila: Remove unnecessary file net/ila.h 2023-08-02 12:28:16 -07:00
netfilter netfilter: xt_mangle: only check verdict part of return value 2023-10-18 10:26:43 +02:00
addrconf_core.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
addrconf.c net: add sysctl to disable rfc4862 5.5.3e lifetime handling 2023-10-03 15:51:04 -07:00
addrlabel.c ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network 2022-11-07 12:26:15 +00:00
af_inet6.c bpf: Propagate modified uaddrlen from cgroup sockaddr programs 2023-10-11 15:03:40 -07:00
ah6.c net: ipv6: Remove completion function scaffolding 2023-02-13 18:35:15 +08:00
anycast.c IPv6: add extack info for IPv6 address add/delete 2023-07-28 11:01:56 +01:00
calipso.c
datagram.c ipv6: lockless IPV6_FLOWINFO_SEND implementation 2023-09-15 10:33:48 +01:00
esp6_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-06-22 18:40:38 -07:00
esp6.c net: ipv6: fix return value check in esp_remove_trailer 2023-10-10 09:55:35 +02:00
exthdrs_core.c ipv6: Fix out-of-bounds access in ipv6_find_tlv() 2023-05-24 08:43:39 +01:00
exthdrs_offload.c
exthdrs.c ipv6: exthdrs: Replace opencoded swap() implementation 2023-08-08 15:36:47 -07:00
fib6_notifier.c
fib6_rules.c ipv6: change fib6_rules_net_exit() to batch mode 2022-02-08 20:41:34 -08:00
fou6.c
icmp.c ipv6: lockless IPV6_DONTFRAG implementation 2023-09-15 10:33:47 +01:00
inet6_connection_sock.c net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
inet6_hashtables.c net: remove duplicate INDIRECT_CALLABLE_DECLARE of udp[6]_ehashfn 2023-07-31 13:53:10 -07:00
ioam6_iptunnel.c ipv6: ioam: Insertion frequency in lwtunnel output 2022-02-04 20:24:45 -08:00
ioam6.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
ip6_checksum.c
ip6_fib.c net/ipv6: Remove expired routes with a separated list of routes. 2023-08-16 12:26:43 +01:00
ip6_flowlabel.c ipv6: move np->repflow to atomic flags 2023-09-15 10:33:48 +01:00
ip6_gre.c net:ipv6: check return value of pskb_trim() 2023-07-19 12:25:58 +01:00
ip6_icmp.c
ip6_input.c ipv6: ignore dst hint for multipath routes 2023-09-01 08:11:51 +01:00
ip6_offload.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
ip6_offload.h
ip6_output.c ipv6: rename and move ip6_dst_lookup_tunnel() 2023-10-23 08:48:57 +01:00
ip6_tunnel.c net: tunnels: annotate lockless accesses to dev->needed_headroom 2023-03-15 00:04:04 -07:00
ip6_udp_tunnel.c ipv6: add new arguments to udp_tunnel6_dst_lookup() 2023-10-23 08:48:57 +01:00
ip6_vti.c ip6_vti: fix slab-use-after-free in decode_session6 2023-07-11 11:06:08 +02:00
ip6mr.c net: ipv4, ipv6: fix IPSTATS_MIB_OUTOCTETS increment duplicated 2023-08-30 09:44:09 +01:00
ipcomp6.c xfrm: ipcomp: add extack to ipcomp{4,6}_init_state 2022-09-29 07:18:00 +02:00
ipv6_sockglue.c ipv6: lockless IPV6_ADDR_PREFERENCES implementation 2023-09-19 18:21:44 +02:00
Kconfig ipv6: fix indentation of a config attribute 2023-08-16 10:03:08 +01:00
Makefile net: ipv6: use ipv6-y directly instead of ipv6-objs 2021-09-28 13:13:40 +01:00
mcast_snoop.c net: bridge: mcast: fix broken length + header check for MRDv6 Adv. 2021-04-27 14:02:06 -07:00
mcast.c net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams. 2023-10-20 12:01:00 +01:00
mip6.c xfrm: mip6: add extack to mip6_destopt_init_state, mip6_rthdr_init_state 2022-09-29 07:18:01 +02:00
ndisc.c net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams. 2023-10-20 12:01:00 +01:00
netfilter.c netfilter: Use l3mdev flow key when re-routing mangled packets 2022-05-16 13:03:29 +02:00
output_core.c treewide: use get_random_u32_{above,below}() instead of manual loop 2022-11-18 02:15:22 +01:00
ping.c bpf: Propagate modified uaddrlen from cgroup sockaddr programs 2023-10-11 15:03:40 -07:00
proc.c net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams. 2023-10-20 12:01:00 +01:00
protocol.c
raw.c net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams. 2023-10-20 12:01:00 +01:00
reassembly.c networking: Update to register_net_sysctl_sz 2023-08-15 15:26:18 -07:00
route.c ipv6: lockless IPV6_ADDR_PREFERENCES implementation 2023-09-19 18:21:44 +02:00
rpl_iptunnel.c ipv6: rpl: Remove redundant skb_dst_drop(). 2023-07-12 17:12:29 -07:00
rpl.c ipv6: rpl: Remove pskb(_may)?_pull() in ipv6_rpl_srh_rcv(). 2023-06-19 11:32:58 -07:00
seg6_hmac.c net: ipv6: unexport __init-annotated seg6_hmac_net_init() 2022-06-28 21:23:30 -07:00
seg6_iptunnel.c seg6: Cleanup duplicates of skb_dst_drop calls 2023-05-17 09:05:47 +01:00
seg6_local.c seg6: add NEXT-C-SID support for SRv6 End.X behavior 2023-08-15 18:51:47 -07:00
seg6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-08 18:38:30 +02:00
sit.c sit: update dev->needed_headroom in ipip6_tunnel_bind_dev() 2023-04-28 09:48:14 +01:00
syncookies.c tcp: Fix data-races around sysctl_tcp_syncookies. 2022-07-18 12:21:54 +01:00
sysctl_net_ipv6.c networking: Update to register_net_sysctl_sz 2023-08-15 15:26:18 -07:00
tcp_ipv6.c tcp: add support for usec resolution in TCP TS values 2023-10-23 09:35:01 +01:00
tcpv6_offload.c net: Make gro complete function to return void 2023-05-31 09:50:17 +01:00
tunnel6.c
udp_impl.h tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct(). 2022-10-12 17:50:37 -07:00
udp_offload.c net: gro: fix misuse of CB in udp socket lookup 2023-07-29 17:10:27 +01:00
udp.c bpf: Propagate modified uaddrlen from cgroup sockaddr programs 2023-10-11 15:03:40 -07:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm6_input.c udp: annotate data-races around udp->encap_type 2023-09-14 16:16:36 +02:00
xfrm6_output.c xfrm: fix tunnel model fragmentation behavior 2022-03-01 12:08:40 +01:00
xfrm6_policy.c ipsec-2023-10-17 2023-10-17 18:21:13 -07:00
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c xfrm: tunnel: add extack to ipip_init_state, xfrm6_tunnel_init_state 2022-09-29 07:18:00 +02:00