Merge branch 'accecn-protocol-patch-series'

Chia-Yu Chang says:

====================
AccECN protocol patch series

Please find the v19 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/
---
Chia-Yu Chang (3):
  tcp: accecn: AccECN option send control
  tcp: accecn: AccECN option failure handling
  tcp: accecn: try to fit AccECN option with SACK

Ilpo Järvinen (7):
  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                           |  28 +-
 include/net/netns/ipv4.h                      |   2 +
 include/net/tcp.h                             |  33 ++
 include/net/tcp_ecn.h                         | 554 +++++++++++++++++-
 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                          | 318 +++++++++-
 net/ipv4/tcp_ipv4.c                           |   8 +-
 net/ipv4/tcp_minisocks.c                      |  40 +-
 net/ipv4/tcp_output.c                         | 239 +++++++-
 net/ipv6/syncookies.c                         |   2 +
 net/ipv6/tcp_ipv6.c                           |   1 +
 16 files changed, 1278 insertions(+), 76 deletions(-)
====================

Link: https://patch.msgid.link/20250916082434.100722-1-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 25 insertions, 3 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index d103cc0e7a35..3ca5ed02de6d 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -122,8 +122,9 @@ struct tcp_options_received {
 		smc_ok : 1,	/* SMC seen on SYN packet		*/
 		snd_wscale : 4,	/* Window scaling received from sender	*/
 		rcv_wscale : 4;	/* Window scaling to send to receiver	*/
-	u8	saw_unknown:1,	/* Received unknown option		*/
-		unused:7;
+	u8	accecn:6,	/* AccECN index in header, 0=no options	*/
+		saw_unknown:1,	/* Received unknown option		*/
+		unused:1;
 	u8	num_sacks;	/* Number of SACK blocks		*/
 	u16	user_mss;	/* mss requested by user in ioctl	*/
 	u16	mss_clamp;	/* Maximal mss, negotiated at connection setup */
@@ -168,6 +169,11 @@ struct tcp_request_sock {
 						  * after data-in-SYN.
 						  */
 	u8				syn_tos;
+	bool				accecn_ok;
+	u8				syn_ect_snt: 2,
+					syn_ect_rcv: 2,
+					accecn_fail_mode:4;
+	u8				saw_accecn_opt  :2;
 #ifdef CONFIG_TCP_AO
 	u8				ao_keyid;
 	u8				ao_rcv_next;
@@ -270,6 +276,7 @@ struct tcp_sock {
 	u32	mdev_us;	/* medium deviation			*/
 	u32	rtt_seq;	/* sequence number to update rttvar	*/
 	u64	tcp_wstamp_ns;	/* departure time for next sent data packet */
+	u64	accecn_opt_tstamp;	/* Last AccECN option sent timestamp */
 	struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
 	struct sk_buff *highest_sack;   /* skb just after the highest
 					 * skb with SACKed bit set
@@ -287,6 +294,12 @@ struct tcp_sock {
  */
 	u8	nonagle     : 4,/* Disable Nagle algorithm?             */
 		rate_app_limited:1;  /* rate_{delivered,interval_us} limited? */
+	u8	received_ce_pending:4, /* Not yet transmit cnt of received_ce */
+		unused2:4;
+	u8	accecn_minlen:2,/* Minimum length of AccECN option sent */
+		est_ecnfield:2,/* ECN field for AccECN delivered estimates */
+		accecn_opt_demand:2,/* Demand AccECN option for n next ACKs */
+		prev_ecnfield:2; /* ECN bits from the previous segment */
 	__be32	pred_flags;
 	u64	tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */
 	u64	tcp_mstamp;	/* most recent packet received/sent */
@@ -299,6 +312,11 @@ struct tcp_sock {
 	u32	snd_up;		/* Urgent pointer		*/
 	u32	delivered;	/* Total data packets delivered incl. rexmits */
 	u32	delivered_ce;	/* Like the above but only ECE marked packets */
+	u32	received_ce;	/* Like the above but for rcvd CE marked pkts */
+	u32	received_ecn_bytes[3]; /* received byte counters for three ECN
+					* types: INET_ECN_ECT_1, INET_ECN_ECT_0,
+					* and INET_ECN_CE
+					*/
 	u32	app_limited;	/* limited until "delivered" reaches this val */
 	u32	rcv_wnd;	/* Current receiver window		*/
 /*
@@ -326,6 +344,7 @@ struct tcp_sock {
 	u32	rate_delivered;    /* saved rate sample: packets delivered */
 	u32	rate_interval_us;  /* saved rate sample: time elapsed */
 	u32	rcv_rtt_last_tsecr;
+	u32	delivered_ecn_bytes[3];
 	u64	first_tx_mstamp;  /* start of window send phase */
 	u64	delivered_mstamp; /* time we reached "delivered" */
 	u64	bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked
@@ -372,7 +391,8 @@ struct tcp_sock {
 	u8	compressed_ack;
 	u8	dup_ack_counter:2,
 		tlp_retrans:1,	/* TLP is a retransmission */
-		unused:5;
+		syn_ect_snt:2,	/* AccECN ECT memory, only */
+		syn_ect_rcv:2;	/* ... needed during 3WHS + first seqno */
 	u8	thin_lto    : 1,/* Use linear timeouts for thin streams */
 		fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
 		fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
@@ -388,6 +408,8 @@ struct tcp_sock {
 		syn_fastopen_child:1; /* created TFO passive child socket */
 
 	u8	keepalive_probes; /* num of allowed keep alive probes	*/
+	u8	accecn_fail_mode:4,	/* AccECN failure handling */
+		saw_accecn_opt:2;	/* An AccECN option was seen */
 	u32	tcp_tx_delay;	/* delay (in usec) added to TX packets */
 
 /* RTT measurement */