netdev - [RFC PATCH net-next 1/2] TCP: note received valid-cookie Fast Open option

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <93b4b95893b9cdd1afc06f22db7f9389a9c906e5.1741877016.git.jgh@exim.org>
Date: Thu, 13 Mar 2025 14:45:50 +0000
From: Jeremy Harris <jgh@...m.org>
To: netdev@...r.kernel.org
Cc: Jeremy Harris <jgh@...m.org>
Subject: [RFC PATCH net-next 1/2] TCP: note received valid-cookie Fast Open option

Signed-off-by: Jeremy Harris <jgh@...m.org>
---
 include/linux/tcp.h     | 3 ++-
 net/ipv4/tcp_fastopen.c | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 159b2c59e..c32c8ba59 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -382,7 +382,8 @@ struct tcp_sock {
 		syn_fastopen:1,	/* SYN includes Fast Open option */
 		syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
 		syn_fastopen_ch:1, /* Active TFO re-enabling probe */
-		syn_data_acked:1;/* data in SYN is acked by SYN-ACK */
+		syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
+		syn_fastopen_in:1; /* Received SYN includes Fast Open option */
 
 	u8	keepalive_probes; /* num of allowed keep alive probes	*/
 	u32	tcp_tx_delay;	/* delay (in usec) added to TX packets */
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 1a6b1bc54..004d0024c 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -401,6 +401,7 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
 				}
 				NET_INC_STATS(sock_net(sk),
 					      LINUX_MIB_TCPFASTOPENPASSIVE);
+				tcp_sk(child)->syn_fastopen_in = 1;
 				return child;
 			}
 			NET_INC_STATS(sock_net(sk),
-- 
2.48.1