summaryrefslogtreecommitdiff
path: root/include/linux/tcp.h
diff options
context:
space:
mode:
authorUrsula Braun <ubraun@linux.vnet.ibm.com>2017-10-25 12:01:45 +0300
committerDavid S. Miller <davem@davemloft.net>2017-10-26 12:00:29 +0300
commit60e2a7780793bae0debc275a9ccd57f7da0cf195 (patch)
tree8b65c6c4eb3194718df692952e1b5d547c53de2f /include/linux/tcp.h
parent145686baab68e9c7594fe9269f47da479c25ad79 (diff)
downloadlinux-60e2a7780793bae0debc275a9ccd57f7da0cf195.tar.xz
tcp: TCP experimental option for SMC
The SMC protocol [1] relies on the use of a new TCP experimental option [2, 3]. With this option, SMC capabilities are exchanged between peers during the TCP three way handshake. This patch adds support for this experimental option to TCP. References: [1] SMC-R Informational RFC: http://www.rfc-editor.org/info/rfc7609 [2] Shared Use of TCP Experimental Options RFC 6994: https://tools.ietf.org/rfc/rfc6994.txt [3] IANA ExID SMCR: http://www.iana.org/assignments/tcp-parameters/tcp-parameters.xhtml#tcp-exids Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/tcp.h')
-rw-r--r--include/linux/tcp.h9
1 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 173a7c2f9636..8c431385b272 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -98,7 +98,8 @@ struct tcp_options_received {
tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
dsack : 1, /* D-SACK is scheduled */
wscale_ok : 1, /* Wscale seen on SYN packet */
- sack_ok : 4, /* SACK seen on SYN packet */
+ sack_ok : 3, /* SACK seen on SYN packet */
+ 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 num_sacks; /* Number of SACK blocks */
@@ -110,6 +111,9 @@ static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
{
rx_opt->tstamp_ok = rx_opt->sack_ok = 0;
rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
+#if IS_ENABLED(CONFIG_SMC)
+ rx_opt->smc_ok = 0;
+#endif
}
/* This is the max number of SACKS that we'll generate and process. It's safe
@@ -229,7 +233,8 @@ struct tcp_sock {
syn_fastopen_ch:1, /* Active TFO re-enabling probe */
syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
save_syn:1, /* Save headers of SYN packet */
- is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
+ is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */
+ syn_smc:1; /* SYN includes SMC */
u32 tlp_high_seq; /* snd_nxt at the time of TLP retransmit. */
/* RTT measurement */