diff options
| author |   Ursula Braun <ubraun@linux.vnet.ibm.com> | 2017-10-25 11:01:45 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-10-26 18:00:29 +0900 |
| commit | 60e2a7780793bae0debc275a9ccd57f7da0cf195 (patch) | |
| tree | 8b65c6c4eb3194718df692952e1b5d547c53de2f /net/ipv4/tcp_minisocks.c | |
| parent | smc: fix mutex unlocks during link group creation (diff) | |
| download | linux-dev-60e2a7780793bae0debc275a9ccd57f7da0cf195.tar.xz linux-dev-60e2a7780793bae0debc275a9ccd57f7da0cf195.zip | |
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 'net/ipv4/tcp_minisocks.c')
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index a952357054f4..056009f1c14f 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -23,6 +23,7 @@ #include <linux/slab.h> #include <linux/sysctl.h> #include <linux/workqueue.h> +#include <linux/static_key.h> #include <net/tcp.h> #include <net/inet_common.h> #include <net/xfrm.h> @@ -416,6 +417,21 @@ void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst) } EXPORT_SYMBOL_GPL(tcp_ca_openreq_child); +static void smc_check_reset_syn_req(struct tcp_sock *oldtp, + struct request_sock *req, + struct tcp_sock *newtp) +{ +#if IS_ENABLED(CONFIG_SMC) + struct inet_request_sock *ireq; + + if (static_branch_unlikely(&tcp_have_smc)) { + ireq = inet_rsk(req); + if (oldtp->syn_smc && !ireq->smc_ok) + newtp->syn_smc = 0; + } +#endif +} + /* This is not only more efficient than what we used to do, it eliminates * a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM * @@ -433,6 +449,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, struct tcp_request_sock *treq = tcp_rsk(req); struct inet_connection_sock *newicsk = inet_csk(newsk); struct tcp_sock *newtp = tcp_sk(newsk); + struct tcp_sock *oldtp = tcp_sk(sk); + + smc_check_reset_syn_req(oldtp, req, newtp); /* Now setup tcp_sock */ newtp->pred_flags = 0; |