linux/net/ipv4
Alexander Duyck 407c85c7dd tcp: Set ECT0 bit in tos/tclass for synack when BPF needs ECN
When a BPF program is used to select between a type of TCP congestion
control algorithm that uses either ECN or not there is a case where the
synack for the frame was coming up without the ECT0 bit set. A bit of
research found that this was due to the final socket being configured to
dctcp while the listener socket was staying in cubic.

To reproduce it all that is needed is to monitor TCP traffic while running
the sample bpf program "samples/bpf/tcp_cong_kern.c". What is observed,
assuming tcp_dctcp module is loaded or compiled in and the traffic matches
the rules in the sample file, is that for all frames with the exception of
the synack the ECT0 bit is set.

To address that it is necessary to make one additional call to
tcp_bpf_ca_needs_ecn using the request socket and then use the output of
that to set the ECT0 bit for the tos/tclass of the packet.

Fixes: 91b5b21c7c ("bpf: Add support for changing congestion control")
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://lore.kernel.org/r/160593039663.2604.1374502006916871573.stgit@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-24 14:12:55 -08:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: use actual socket sk rather than skb sk when routing harder 2020-10-30 12:57:39 +01:00
af_inet.c io_uring: allow tcp ancillary data for __sys_recvmsg_sock() 2020-08-24 16:16:06 -07:00
ah4.c inet: Use fallthrough; 2020-03-12 15:55:00 -07:00
arp.c net: Exempt multicast addresses from five-second neighbor lifetime 2020-11-13 14:24:39 -08:00
bpf_tcp_ca.c bpf: Change bpf_sk_storage_*() to accept ARG_PTR_TO_BTF_ID_SOCK_COMMON 2020-09-25 13:58:01 -07:00
cipso_ipv4.c cipso: fix 'audit_secid' kernel-doc warning in cipso_ipv4.c 2020-09-08 20:03:36 -07:00
datagram.c
devinet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
esp4_offload.c net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
esp4.c ESP: Export esp_output_fill_trailer function 2020-02-19 13:52:32 +01:00
fib_frontend.c ipv4: use IS_ENABLED instead of ifdef 2020-11-17 17:02:03 -08:00
fib_lookup.h net: add net available in build_state 2020-03-29 22:30:57 -07:00
fib_notifier.c
fib_rules.c fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
fib_semantics.c net: Fix the arp error in some cases 2020-06-18 20:21:51 -07:00
fib_trie.c ipv4: Silence suspicious RCU usage warning 2020-08-26 15:58:48 -07:00
fou.c genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
gre_demux.c gre: fix uninit-value in __iptunnel_pull_header 2020-03-08 21:25:37 -07:00
gre_offload.c net: gre: recompute gre csum for sctp over gre tunnels 2020-08-03 15:29:44 -07:00
icmp.c icmp: randomize the global rate limiter 2020-10-16 16:47:09 -07:00
igmp.c ip*_mc_gsfget(): lift copyout of struct group_filter into callers 2020-05-20 20:31:27 -04:00
inet_connection_sock.c tcp: fix race condition when creating child sockets from syncookies 2020-11-23 16:32:33 -08:00
inet_diag.c inet_diag: Fix error path to cancel the meseage in inet_req_diag_fill() 2020-11-17 16:08:36 -08:00
inet_fragment.c
inet_hashtables.c tcp: fix race condition when creating child sockets from syncookies 2020-11-23 16:32:33 -08:00
inet_timewait_sock.c
inetpeer.c
ip_forward.c
ip_fragment.c
ip_gre.c ip_gre: set dev->hard_header_len and dev->needed_headroom properly 2020-10-13 18:35:29 -07:00
ip_input.c bpf: Add socket assign support 2020-03-30 13:45:04 -07:00
ip_options.c net: clean up codestyle for net/ipv4 2020-08-25 06:28:02 -07:00
ip_output.c networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
ip_sockglue.c net: Remove duplicated midx check against 0 2020-08-25 06:23:59 -07:00
ip_tunnel_core.c tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies 2020-11-09 15:39:39 -08:00
ip_tunnel.c ip_tunnel: fix over-mtu packet send fail without TUNNEL_DONT_FRAGMENT flags 2020-10-31 17:19:02 -07:00
ip_vti.c ipv4: use dev_sw_netstats_rx_add() 2020-10-06 06:23:21 -07:00
ipcomp.c ipcomp: assign if_id to child tunnel from parent tunnel 2020-07-09 12:55:37 +02:00
ipconfig.c Documentation: nfsroot.rst: Fix references to nfsroot.rst 2020-03-02 13:11:46 -07:00
ipip.c net: ipip: implement header_ops->parse_protocol for AF_PACKET 2020-06-30 12:29:39 -07:00
ipmr_base.c
ipmr.c ipmr: Use full VIF ID in netlink cache reports 2020-09-10 12:25:51 -07:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
metrics.c
netfilter.c netfilter: use actual socket sk rather than skb sk when routing harder 2020-10-30 12:57:39 +01:00
netlink.c
nexthop.c nexthop: Fix performance regression in nexthop deletion 2020-10-19 20:07:15 -07:00
ping.c net: clean up codestyle 2020-08-31 12:33:34 -07:00
proc.c tcp: skip DSACKs with dubious sequence ranges 2020-09-24 20:15:45 -07:00
protocol.c
raw_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
raw.c networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-15 12:43:21 -07:00
syncookies.c net: Update window_clamp if SOCK_RCVBUF is set 2020-11-10 17:42:35 -08:00
sysctl_net_ipv4.c tcp: reflect tos value received in SYN to the socket 2020-09-10 13:15:40 -07:00
tcp_bbr.c tcp: only postpone PROBE_RTT if RTT is < current min_rtt estimate 2020-11-17 11:03:22 -08:00
tcp_bic.c tcp: fix stretch ACK bugs in BIC 2020-03-16 18:26:54 -07:00
tcp_bpf.c bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect 2020-11-18 00:12:34 +01:00
tcp_cdg.c
tcp_cong.c tcp: Set INET_ECN_xmit configuration in tcp_reinit_congestion_control 2020-11-20 18:09:47 -08:00
tcp_cubic.c tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT 2020-06-25 16:08:47 -07:00
tcp_dctcp.c
tcp_dctcp.h
tcp_diag.c inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data 2020-02-27 18:50:19 -08:00
tcp_fastopen.c bpf: tcp: Add bpf_skops_established() 2020-08-24 14:35:00 -07:00
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: Prevent low rmem stalls with SO_RCVLOWAT. 2020-10-23 19:11:20 -07:00
tcp_ipv4.c tcp: Set ECT0 bit in tos/tclass for synack when BPF needs ECN 2020-11-24 14:12:55 -08:00
tcp_lp.c
tcp_metrics.c genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
tcp_minisocks.c bpf: tcp: Do not limit cb_flags when creating child sk from listen sk 2020-10-02 11:34:48 -07:00
tcp_nv.c
tcp_offload.c
tcp_output.c tcp: add exponential backoff in __tcp_send_ack() 2020-09-30 14:21:30 -07:00
tcp_rate.c
tcp_recovery.c tcp: move tcp_mark_skb_lost 2020-09-25 17:17:14 -07:00
tcp_scalable.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
tcp_timer.c inet: remove icsk_ack.blocked 2020-09-30 14:21:30 -07:00
tcp_ulp.c bpf: sockmap: Only check ULP for TCP sockets 2020-03-09 22:34:58 +01:00
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: fix stretch ACK bugs in Yeah 2020-03-16 18:26:55 -07:00
tcp.c tcp: Prevent low rmem stalls with SO_RCVLOWAT. 2020-10-23 19:11:20 -07:00
tunnel4.c tunnel4: add cb_handler to struct xfrm_tunnel 2020-07-09 12:51:36 +02:00
udp_bpf.c net: sk_msg: Simplify sk_psock initialization 2020-08-21 15:16:11 -07:00
udp_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c net: udp: fix IP header access and skb lookup on Fast/frag0 UDP GRO 2020-11-12 09:55:51 -08:00
udp_tunnel_core.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp_tunnel_nic.c udp_tunnel: add the ability to share port tables 2020-09-28 12:50:12 -07:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
udplite.c net/ipv4: remove compat_ip_{get,set}sockopt 2020-07-19 18:16:41 -07:00
xfrm4_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_output.c xfrm: fix unused variable warning if CONFIG_NETFILTER=n 2020-05-11 15:12:27 +02:00
xfrm4_policy.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2019-12-24 22:28:54 -08:00
xfrm4_protocol.c
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c xfrm: interface: fix the priorities for ipip and ipv6 tunnels 2020-10-09 12:29:48 +02:00