OpenCloudOS-Kernel/net/ipv4
Pengcheng Yang d9157f6806 tcp: fix F-RTO may not work correctly when receiving DSACK
Currently DSACK is regarded as a dupack, which may cause
F-RTO to incorrectly enter "loss was real" when receiving
DSACK.

Packetdrill to demonstrate:

// Enable F-RTO and TLP
    0 `sysctl -q net.ipv4.tcp_frto=2`
    0 `sysctl -q net.ipv4.tcp_early_retrans=3`
    0 `sysctl -q net.ipv4.tcp_congestion_control=cubic`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

// RTT 10ms, RTO 210ms
  +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
   +0 > S. 0:0(0) ack 1 <...>
 +.01 < . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 2 data segments
   +0 write(4, ..., 2000) = 2000
   +0 > P. 1:2001(2000) ack 1

// TLP
+.022 > P. 1001:2001(1000) ack 1

// Continue to send 8 data segments
   +0 write(4, ..., 10000) = 10000
   +0 > P. 2001:10001(8000) ack 1

// RTO
+.188 > . 1:1001(1000) ack 1

// The original data is acked and new data is sent(F-RTO step 2.b)
   +0 < . 1:1(0) ack 2001 win 257
   +0 > P. 10001:12001(2000) ack 1

// D-SACK caused by TLP is regarded as a dupack, this results in
// the incorrect judgment of "loss was real"(F-RTO step 3.a)
+.022 < . 1:1(0) ack 2001 win 257 <sack 1001:2001,nop,nop>

// Never-retransmitted data(3001:4001) are acked and
// expect to switch to open state(F-RTO step 3.b)
   +0 < . 1:1(0) ack 4001 win 257
+0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }%

Fixes: e33099f96d ("tcp: implement RFC5682 F-RTO")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1650967419-2150-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-28 10:35:38 -07:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: flowtable: Remove the empty file 2022-04-25 10:37:33 +02:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile bpf: Clean up sockmap related Kconfigs 2021-02-26 12:28:03 -08:00
af_inet.c gso: do not skip outer ip header in case of ipip and net_failover 2022-02-21 11:41:30 +00:00
ah4.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
arp.c net: neigh: add skb drop reasons to arp_error_report() 2022-02-26 12:53:59 +00:00
bpf_tcp_ca.c bpf: reject program if a __user tagged memory accessed in kernel way 2022-01-27 12:03:46 -08:00
cipso_ipv4.c NET: IPV4: fix error "do not initialise globals to 0" 2021-09-19 12:43:56 +01:00
datagram.c net/ipv4/datagram.c: remove superfluous header files from datagram.c 2021-09-29 11:39:33 +01:00
devinet.c net: Add new protocol attribute to IP addresses 2022-02-18 21:20:06 -08:00
esp4.c esp: limit skb_page_frag_refill use to a single page 2022-04-13 10:16:11 +02:00
esp4_offload.c net: Fix esp GSO on inter address family tunnels. 2022-03-07 13:14:04 +01:00
fib_frontend.c net: Add l3mdev index to flow struct and avoid oif reset for port devices 2022-03-15 20:20:02 -07:00
fib_lookup.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
fib_notifier.c net: ipv4: remove superfluous header files from fib_notifier.c 2021-09-28 17:32:56 -07:00
fib_rules.c ipv4: Reject again rules with high DSCP values 2022-02-10 15:33:33 +00:00
fib_semantics.c net: ipv4: fix route with nexthop object delete warning 2022-04-01 12:09:17 +01:00
fib_trie.c net: Add l3mdev index to flow struct and avoid oif reset for port devices 2022-03-15 20:20:02 -07:00
fou.c gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
gre_demux.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
gre_offload.c gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
icmp.c ipv4: do not use per netns icmp sockets 2022-01-25 11:25:21 +00:00
igmp.c ipv4: drop unused assignment 2021-11-14 12:20:44 +00:00
inet_connection_sock.c tcp: Use BPF timeout setting for SYN ACK RTO 2022-02-02 14:45:18 +00:00
inet_diag.c inet_diag: fix kernel-infoleak for UDP sockets 2021-12-10 21:14:49 -08:00
inet_fragment.c net: ip: Handle delivery_time in ip defrag 2022-03-03 14:38:48 +00:00
inet_hashtables.c tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH. 2022-02-09 21:28:36 -08:00
inet_timewait_sock.c tcp: allocate tcp_death_row outside of struct netns_ipv4 2022-01-26 19:00:31 -08:00
inetpeer.c inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold 2021-03-01 13:32:12 -08:00
ip_forward.c net: Add skb_clear_tstamp() to keep the mono delivery_time 2022-03-03 14:38:48 +00:00
ip_fragment.c net: ip: Handle delivery_time in ip defrag 2022-03-03 14:38:48 +00:00
ip_gre.c ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md mode 2022-04-25 11:40:45 +01:00
ip_input.c net: Postpone skb_clear_delivery_time() until knowing the skb is delivered locally 2022-03-03 14:38:48 +00:00
ip_options.c ipv4: drop fragmentation code from ip_options_build() 2022-01-29 17:53:07 +00:00
ip_output.c net: Set skb->mono_delivery_time and clear it after sch_handle_ingress() 2022-03-03 14:38:48 +00:00
ip_sockglue.c ipv4: Exposing __ip_sock_set_tos() in ip.h 2021-11-20 14:11:00 +00:00
ip_tunnel.c net: Handle l3mdev in ip_tunnel_init_flow 2022-04-15 14:27:30 -07:00
ip_tunnel_core.c net: ip_tunnel: clean up endianness conversions 2021-01-08 19:25:35 -08:00
ip_vti.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ipcomp.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
ipconfig.c net: ipconfig: Release the rtnl_lock while waiting for carrier 2021-10-28 14:36:41 +01:00
ipip.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ipmr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-10 17:29:56 -08:00
ipmr_base.c
metrics.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netfilter.c netfilter: Dissect flow after packet mangling 2021-04-18 22:04:16 +02:00
netlink.c
nexthop.c nexthop: change nexthop_net_exit() to nexthop_net_exit_batch() 2022-02-08 20:41:33 -08:00
ping.c ping: remove pr_err from ping_lookup 2022-02-24 09:18:29 -08:00
proc.c tcp: allocate tcp_death_row outside of struct netns_ipv4 2022-01-26 19:00:31 -08:00
protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
raw.c Networking fixes for 5.17-rc2, including fixes from netfilter and can. 2022-01-27 20:58:39 +02:00
raw_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-23 10:53:49 -07:00
syncookies.c tcp: make sure treq->af_specific is initialized 2022-04-25 12:10:11 +01:00
sysctl_net_ipv4.c tcp: adjust TSO packet sizes based on min_rtt 2022-03-09 20:05:44 -08:00
tcp.c tcp: autocork: take MSG_EOR hint into consideration 2022-03-09 20:05:20 -08:00
tcp_bbr.c bpf: Remove check_kfunc_call callback and old kfunc BTF ID API 2022-01-18 14:26:41 -08:00
tcp_bic.c
tcp_bpf.c bpf, sockmap: Fix double uncharge the mem of sk_msg 2022-03-15 16:43:31 +01:00
tcp_cdg.c
tcp_cong.c tcp: unexport tcp_ca_get_key_by_name and tcp_ca_get_name_by_key 2022-03-11 22:51:40 -08:00
tcp_cubic.c bpf: Remove check_kfunc_call callback and old kfunc BTF ID API 2022-01-18 14:26:41 -08:00
tcp_dctcp.c bpf: Remove check_kfunc_call callback and old kfunc BTF ID API 2022-01-18 14:26:41 -08:00
tcp_dctcp.h
tcp_diag.c
tcp_fastopen.c net/ipv4/tcp_fastopen.c: remove superfluous header files from tcp_fastopen.c 2021-09-20 13:09:06 +01:00
tcp_highspeed.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_htcp.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: fix F-RTO may not work correctly when receiving DSACK 2022-04-28 10:35:38 -07:00
tcp_ipv4.c tcp: adjust TSO packet sizes based on min_rtt 2022-03-09 20:05:44 -08:00
tcp_lp.c ipv4: tcp_lp.c: Couple of typo fixes 2021-03-28 17:31:13 -07:00
tcp_metrics.c fixes-v5.11 2020-12-14 16:40:27 -08:00
tcp_minisocks.c tcp: md5: incorrect tcp_header_len for incoming connections 2022-04-22 15:05:59 -07:00
tcp_nv.c net/ipv4/tcp_nv.c: remove superfluous header files from tcp_nv.c 2021-09-27 12:47:39 +01:00
tcp_offload.c net: move gro definitions to include/net/gro.h 2021-11-16 13:16:54 +00:00
tcp_output.c tcp: fix potential xmit stalls caused by TCP_NOTSENT_LOWAT 2022-04-25 12:07:45 +01:00
tcp_rate.c tcp: ensure to use the most recently sent skb when filling the rate sample 2022-04-22 15:20:47 -07:00
tcp_recovery.c tcp: more accurately check DSACKs to grow RACK reordering window 2021-07-27 20:07:21 +01:00
tcp_scalable.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
tcp_timer.c net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
tcp_ulp.c
tcp_vegas.c tcp: use semicolons rather than commas to separate statements 2020-10-13 17:11:52 -07:00
tcp_vegas.h
tcp_veno.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_westwood.c
tcp_yeah.c tcp_yeah: check struct yeah size at compile time 2021-06-29 11:54:36 -07:00
tunnel4.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
udp.c net: udp: use kfree_skb_reason() in __udp_queue_rcv_skb() 2022-02-07 11:18:49 +00:00
udp_bpf.c net: Implement ->sock_is_readable() for UDP and AF_UNIX 2021-10-26 12:29:33 -07:00
udp_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
udp_tunnel_core.c net/ipv4/udp_tunnel_core.c: remove superfluous header files from udp_tunnel_core.c 2021-09-21 10:17:20 +01:00
udp_tunnel_nic.c udp_tunnel: Fix end of loop test in udp_tunnel_nic_unregister() 2022-02-23 12:35:00 +00:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udplite.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_input.c
xfrm4_output.c
xfrm4_policy.c net: Add l3mdev index to flow struct and avoid oif reset for port devices 2022-03-15 20:20:02 -07:00
xfrm4_protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_state.c
xfrm4_tunnel.c net/ipv4/xfrm4_tunnel.c: remove superfluous header files from xfrm4_tunnel.c 2021-09-23 10:10:00 +02:00