diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2026-03-14 18:02:52 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-14 18:02:52 +0300 |
| commit | b58e3a2d014567a9092eb026fe677ff4bed5af38 (patch) | |
| tree | 05110a05efb4bacc1c87491ef69ef50eea499dc2 /include | |
| parent | 9089c5f3c444ad6e9eb172e9375615ed0b0bc31c (diff) | |
| parent | 3eb371eddad0a47183dd4434de9c9190d0f721c5 (diff) | |
| download | linux-b58e3a2d014567a9092eb026fe677ff4bed5af38.tar.xz | |
Merge branch 'tcp-rfc-7323-compliant-window-retraction-handling'
Simon Baatz says:
====================
tcp: RFC 7323-compliant window retraction handling
this series implements the receiver-side requirements for TCP window
retraction as specified in RFC 7323 and adds packetdrill tests to
cover the new behavior.
Please see the first patch for background and implementation
details. Since MPTCP adjusts the TCP receive window on subflows, the
relevant MPTCP code paths are updated accordingly.
====================
Link: https://patch.msgid.link/20260309-tcp_rfc7323_retract_wnd_rfc-v3-0-4c7f96b1ec69@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/tcp.h | 3 | ||||
| -rw-r--r-- | include/net/tcp.h | 22 |
2 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index bcebc4f07532..6982f10e826b 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -316,6 +316,9 @@ struct tcp_sock { */ u32 app_limited; /* limited until "delivered" reaches this val */ u32 rcv_wnd; /* Current receiver window */ + u32 rcv_mwnd_seq; /* Maximum window sequence number (RFC 7323, + * section 2.4, receiver requirements) + */ u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ /* * Options received (usually on last packet, some only on SYN packets). diff --git a/include/net/tcp.h b/include/net/tcp.h index 48dffcca0a71..f87bdacb5a69 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -934,6 +934,28 @@ static inline u32 tcp_receive_window(const struct tcp_sock *tp) return (u32) win; } +/* Compute the maximum receive window we ever advertised. + * Rcv_nxt can be after the window if our peer push more data + * than the offered window. + */ +static inline u32 tcp_max_receive_window(const struct tcp_sock *tp) +{ + s32 win = tp->rcv_mwnd_seq - tp->rcv_nxt; + + if (win < 0) + win = 0; + return (u32) win; +} + +/* Check if we need to update the maximum receive window sequence number */ +static inline void tcp_update_max_rcv_wnd_seq(struct tcp_sock *tp) +{ + u32 wre = tp->rcv_wup + tp->rcv_wnd; + + if (after(wre, tp->rcv_mwnd_seq)) + tp->rcv_mwnd_seq = wre; +} + /* Choose a new window, without checks for shrinking, and without * scaling applied to the result. The caller does these things * if necessary. This is a "raw" window selection. |