From: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com
Hello,
Please find the v18 AccECN protocol patch series, which covers the core functionality of Accurate ECN, AccECN negotiation, AccECN TCP options, and AccECN failure handling. The Accurate ECN draft can be found in https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-accurate-ecn-28, and it will be RFC9768.
This patch series is part of the full AccECN patch series, which is available at https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/
Best Regards, Chia-Yu
--- v18 (11-Sep-2025) - Reorder tcpi_accecn_fail_mode and tcpi_accecn_opt_seen to avoid adding fields in the middle of tcp_info (Eric Dumazet edumazet@google.com)
v17 (8-Sep-2025) - Change tcp_ecn_mode_max from 5 to 2 to disable AccECN enablement before the whole AccECN feature been accpeted
v16 (6-Sep-2025) - Use TCP_ECN_IN_ACCECN_OUT_ACCECN, TCP_ECN_IN_ECN_OUT_ECN, and TCP_ECN_IN_ACCECN_OUT_ECN in comments of tcp_ecn_send_syn() (Eric Dumazet edumazet@google.com) - Add tcpi_accecn_fail_mode and tcpi_accecn_opt_seen to make tcp_info be multiple of 64 bits in patch #12
v15 (14-Aug-205) - Update pahole results in commit messages - Accurate ECN will become RFC9768
v14 (22-Jul-2025) - Add missing const for struct tcp_sock of tcp_accecn_option_beacon_check() of #11 (Simon Horman horms@kernel.org)
v13 (18-Jul-2025) - Implement tcp_accecn_extract_syn_ect() and tcp_accecn_reflector_flags() with static array lookup of patch #6 (Paolo Abeni pabeni@redhat.com) - Fix typos in comments of #6 and remove patch #7 of v12 about simulatenous connect (Paolo Abeni pabeni@redhat.com) - Move TCP_ACCECN_E1B_INIT_OFFSET, TCP_ACCECN_E0B_INIT_OFFSET, and TCP_ACCECN_CEB_INIT_OFFSET from patch #7 to #11 (Paolo Abeni pabeni@redhat.com) - Use static array lookup in tcp_accecn_optfield_to_ecnfield() of patch #11 (Paolo Abeni pabeni@redhat.com) - Return false when WARN_ON_ONCE() is true in tcp_accecn_process_option() of patch #11 (Paolo Abeni pabeni@redhat.com) - Make synack_ecn_bytes as static const array and use const u32 pointer in tcp_options_write() of #11 (Paolo Abeni pabeni@redhat.com) - Use ALIGN() and ALIGN_DOWN() in tcp_options_fit_accecn() to pad TCP AccECN option to dword of #11 (Paolo Abeni pabeni@redhat.com) - Return TCP_ACCECN_OPT_FAIL_SEEN if WARN_ON_ONCE() is true in tcp_accecn_option_init() of #12 (Paolo Abeni pabeni@redhat.com)
v12 (04-Jul-2025) - Fix compilation issues with some intermediate patches in v11 - Add more comments for AccECN helpers of tcp_ecn.h
v11 (03-Jul-2025) - Fix compilation issues with some intermediate patches in v10
v10 (02-Jul-2025) - Add new patch of separated header file include/net/tcp_ecn.h to include ECN and AccECN functions (Eric Dumazet edumazet@google.com) - Add comments on the AccECN helper functions in tcp_ecn.h (Eric Dumazet edumazet@google.com) - Add documentation of tcp_ecn, tcp_ecn_option, tcp_ecn_beacon in ip-sysctl.rst to the corresponding patch (Eric Dumazet edumazet@google.com) - Split wait third ACK functionality into a separated patch from AccECN negotiation patch (Eric Dumazet edumazet@google.com) - Add READ_ONCE() over every reads of sysctl for all patches in the series (Eric Dumazet edumazet@google.com) - Merge heuristics of AccECN option ceb/cep and ACE field multi-wrap into a single patch - Add a table of SACK block reduction and required AccECN field in patch #15 commit message (Eric Dumazet edumazet@google.com)
v9 (21-Jun-2025) - Use tcp_data_ecn_check() to set TCP_ECN_SEE flag only for RFC3168 ECN (Paolo Abeni pabeni@redhat.com) - Add comments about setting TCP_ECN_SEEN flag for RFC3168 and Accruate ECN (Paolo Abeni pabeni@redhat.com) - Restruct the code in the for loop of tcp_accecn_process_option() (Paolo Abeni pabeni@redhat.com) - Remove ecn_bytes and add use_synack_ecn_bytes flag to identify whether syn_ack_bytes or received_ecn_bytes is used (Paolo Abeni pabeni@redhat.com) - Replace leftover_bytes and leftover_size with leftover_highbyte and leftover_lowbyte and add comments in tcp_options_write() (Paolo Abeni pabeni@redhat.com) - Add comments and commit message about the 1st retx SYN still attempt AccECN negotiation (Paolo Abeni pabeni@redhat.com)
v8 (10-Jun-2025) - Add new helper function tcp_ecn_received_counters_payload() in #6 (Paolo Abeni pabeni@redhat.com) - Set opts->num_sack_blocks=0 to avoid potential undefined value in #8 (Paolo Abeni pabeni@redhat.com) - Reset leftover_size to 2 once leftover_bytes is used in #9 (Paolo Abeni pabeni@redhat.com) - Add new helper function tcp_accecn_opt_demand_min() in #10 (Paolo Abeni pabeni@redhat.com) - Add new helper function tcp_accecn_saw_opt_fail_recv() in #11 (Paolo Abeni pabeni@redhat.com) - Update tcp_options_fit_accecn() to avoid using recursion in #14 (Paolo Abeni pabeni@redhat.com)
v7 (14-May-2025) - Modify group sizes of tcp_sock_write_txrx and tcp_sock_write_rx in #3 based on pahole results (Paolo Abeni pabeni@redhat.com) - Fix the issue in #4 and #5 where the RFC3168 ECN behavior in tcp_ecn_send() is changed (Paolo Abeni pabeni@redhat.com) - Modify group size of tcp_sock_write_txrx in #4 and #6 based on pahole results (Paolo Abeni pabeni@redhat.com) - Update commit message for #9 to explain the increase in tcp_sock_write_rx group size - Modify group size of tcp_sock_write_tx in #10 based on pahole results
v6 (09-May-2025) - Add #3 to utilize exisintg holes of tcp_sock_write_txrx group for later patches (#4, #9, #10) with new u8 members (Paolo Abeni pabeni@redhat.com) - Add pahole outcomes before and after commit in #4, #5, #6, #9, #10, #15 (Paolo Abeni pabeni@redhat.com) - Define new helper function tcp_send_ack_reflect_ect() for sending ACK with reflected ECT in #5 (Paolo Abeni pabeni@redhat.com) - Add comments for function tcp_ecn_rcv_synack() in #5 (Paolo Abeni pabeni@redhat.com) - Add enum/define to be used by sysctl_tcp_ecn in #5, sysctl_tcp_ecn_option in #9, and sysctl_tcp_ecn_option_beacon in #10 (Paolo Abeni pabeni@redhat.com) - Move accecn_fail_mode and saw_accecn_opt in #5 and #11 to use exisintg holes of tcp_sock (Paolo Abeni pabeni@redhat.com) - Change data type of new members of tcp_request_sock and move them to the end of struct in #5 and #11 (Paolo Abeni pabeni@redhat.com) - Move new members of tcp_info to the end of struct in #6 (Paolo Abeni pabeni@redhat.com) - Merge previous #7 into #9 (Paolo Abeni pabeni@redhat.com) - Mask ecnfield with INET_ECN_MASK to remove WARN_ONCE in #9 (Paolo Abeni pabeni@redhat.com) - Reduce the indentation levels for reabability in #9 and #10 (Paolo Abeni pabeni@redhat.com) - Move delivered_ecn_bytes to the RX group in #9, accecn_opt_tstamp to the TX group in #10, pkts_acked_ewma to the RX group in #15 (Paolo Abeni pabeni@redhat.com) - Add changes in Documentation/networking/net_cachelines/tcp_sock.rst for new tcp_sock members in #3, #5, #6, #9, #10, #15
v5 (22-Apr-2025) - Further fix for 32-bit ARM alignment in tcp.c (Simon Horman horms@kernel.org)
v4 (18-Apr-2025) - Fix 32-bit ARM assertion for alignment requirement (Simon Horman horms@kernel.org)
v3 (14-Apr-2025) - Fix patch apply issue in v2 (Jakub Kicinski kuba@kernel.org)
v2 (18-Mar-2025) - Add one missing patch from the previous AccECN protocol preparation patch series to this patch series.
--- Chia-Yu Chang (5): tcp: reorganize tcp_sock_write_txrx group for variables later tcp: ecn functions in separated include file tcp: accecn: AccECN option send control tcp: accecn: AccECN option failure handling tcp: accecn: try to fit AccECN option with SACK
Ilpo Järvinen (9): tcp: reorganize SYN ECN code tcp: fast path functions later tcp: AccECN core tcp: accecn: AccECN negotiation tcp: accecn: add AccECN rx byte counters tcp: accecn: AccECN needs to know delivered bytes tcp: sack option handling improvements tcp: accecn: AccECN option tcp: accecn: AccECN option ceb/cep and ACE field multi-wrap heuristics
Documentation/networking/ip-sysctl.rst | 55 +- .../networking/net_cachelines/tcp_sock.rst | 12 + include/linux/tcp.h | 32 +- include/net/netns/ipv4.h | 2 + include/net/tcp.h | 87 ++- include/net/tcp_ecn.h | 642 ++++++++++++++++++ include/uapi/linux/tcp.h | 9 + net/ipv4/syncookies.c | 4 + net/ipv4/sysctl_net_ipv4.c | 19 + net/ipv4/tcp.c | 30 +- net/ipv4/tcp_input.c | 353 ++++++++-- net/ipv4/tcp_ipv4.c | 8 +- net/ipv4/tcp_minisocks.c | 40 +- net/ipv4/tcp_output.c | 294 ++++++-- net/ipv6/syncookies.c | 2 + net/ipv6/tcp_ipv6.c | 1 + 16 files changed, 1406 insertions(+), 184 deletions(-) create mode 100644 include/net/tcp_ecn.h