diff options
| author |   Jakub Kicinski <kuba@kernel.org> | 2025-04-24 18:21:07 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-24 18:21:07 -0700 |
| commit | a764e8114d2d80e8b0f453084b2e9fcc6454b7a1 (patch) | |
| tree | 56b3c3d26b4e65bbe2ab42f02a6b71c632818cbb | |
| parent | net: ip_gre: Fix spelling mistake "demultiplexor" -> "demultiplexer" (diff) | |
| parent | tcp: fastopen: pass TFO child indication through getsockopt (diff) | |
| download | wireguard-linux-a764e8114d2d80e8b0f453084b2e9fcc6454b7a1.tar.xz wireguard-linux-a764e8114d2d80e8b0f453084b2e9fcc6454b7a1.zip | |
Merge branch 'tcp-fastopen-observability'
Jeremy Harris says:
====================
tcp: fastopen: observability
Whether TCP Fast Open was used for a connection is not reliably
observable by an accepting application when the SYN passed no data.
Fix this by noting during SYN receive processing that an acceptable Fast
Open option was used, and provide this to userland via getsockopt TCP_INFO.
====================
Link: https://patch.msgid.link/20250423124334.4916-1-jgh@exim.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/linux/tcp.h | 3 | ||||
| -rw-r--r-- | include/uapi/linux/tcp.h | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_fastopen.c | 1 |
4 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 1669d95bb0f9..a8af71623ba7 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -385,7 +385,8 @@ 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_child:1; /* created TFO passive child socket */ u8 keepalive_probes; /* num of allowed keep alive probes */ u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index dc8fdc80e16b..bdac8c42fa82 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -184,6 +184,7 @@ enum tcp_fastopen_client_fail { #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ #define TCPI_OPT_USEC_TS 64 /* usec timestamps */ +#define TCPI_OPT_TFO_CHILD 128 /* child from a Fast Open option on SYN */ /* * Sender's congestion state indicating normal or abnormal situations diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e0e96f8fd47c..86c427f16636 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3409,6 +3409,7 @@ int tcp_disconnect(struct sock *sk, int flags) tp->rack.reo_wnd_persist = 0; tp->rack.dsack_seen = 0; tp->syn_data_acked = 0; + tp->syn_fastopen_child = 0; tp->rx_opt.saw_tstamp = 0; tp->rx_opt.dsack = 0; tp->rx_opt.num_sacks = 0; @@ -4164,6 +4165,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_options |= TCPI_OPT_SYN_DATA; if (tp->tcp_usec_ts) info->tcpi_options |= TCPI_OPT_USEC_TS; + if (tp->syn_fastopen_child) + info->tcpi_options |= TCPI_OPT_TFO_CHILD; info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); info->tcpi_ato = jiffies_to_usecs(min_t(u32, icsk->icsk_ack.ato, diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 1a6b1bc54245..9b83d639b5ac 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -401,6 +401,7 @@ fastopen: } NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVE); + tcp_sk(child)->syn_fastopen_child = 1; return child; } NET_INC_STATS(sock_net(sk), |