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authorUrsula Braun <ubraun@linux.vnet.ibm.com>2017-10-25 11:01:45 +0200
committerDavid S. Miller <davem@davemloft.net>2017-10-26 18:00:29 +0900
commit60e2a7780793bae0debc275a9ccd57f7da0cf195 (patch)
tree8b65c6c4eb3194718df692952e1b5d547c53de2f /include/net/tcp.h
parent145686baab68e9c7594fe9269f47da479c25ad79 (diff)
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/net/tcp.h')
-rw-r--r--include/net/tcp.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 2392f74074e7..285bc82dea41 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -191,6 +191,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
* experimental options. See draft-ietf-tcpm-experimental-options-00.txt
*/
#define TCPOPT_FASTOPEN_MAGIC 0xF989
+#define TCPOPT_SMC_MAGIC 0xE2D4C3D9
/*
* TCP option lengths
@@ -203,6 +204,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
#define TCPOLEN_MD5SIG 18
#define TCPOLEN_FASTOPEN_BASE 2
#define TCPOLEN_EXP_FASTOPEN_BASE 4
+#define TCPOLEN_EXP_SMC_BASE 6
/* But this is what stacks really send out. */
#define TCPOLEN_TSTAMP_ALIGNED 12
@@ -213,6 +215,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
#define TCPOLEN_SACK_PERBLOCK 8
#define TCPOLEN_MD5SIG_ALIGNED 20
#define TCPOLEN_MSS_ALIGNED 4
+#define TCPOLEN_EXP_SMC_BASE_ALIGNED 8
/* Flags in tp->nonagle */
#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
@@ -2108,4 +2111,8 @@ static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk)
{
return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN) == 1);
}
+
+#if IS_ENABLED(CONFIG_SMC)
+extern struct static_key_false tcp_have_smc;
+#endif
#endif /* _TCP_H */