diff options
| author | Florian Westphal <fw@strlen.de> | 2020-11-30 16:36:30 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-12-03 21:56:03 +0100 |
| commit | 7ea851d19b23593d7601ecb8091d529f4f475bf5 (patch) | |
| tree | ee60d28532343974c65fcc8876e2341c0931e18d /net/ipv4/tcp_input.c | |
| parent | security: add const qualifier to struct sock in various places (diff) | |
| download | linux-7ea851d19b23593d7601ecb8091d529f4f475bf5.tar.xz linux-7ea851d19b23593d7601ecb8091d529f4f475bf5.zip | |
tcp: merge 'init_req' and 'route_req' functions
The Multipath-TCP standard (RFC 8684) says that an MPTCP host should send
a TCP reset if the token in a MP_JOIN request is unknown.
At this time we don't do this, the 3whs completes and the 'new subflow'
is reset afterwards. There are two ways to allow MPTCP to send the
reset.
1. override 'send_synack' callback and emit the rst from there.
The drawback is that the request socket gets inserted into the
listeners queue just to get removed again right away.
2. Send the reset from the 'route_req' function instead.
This avoids the 'add&remove request socket', but route_req lacks the
skb that is required to send the TCP reset.
Instead of just adding the skb to that function for MPTCP sake alone,
Paolo suggested to merge init_req and route_req functions.
This saves one indirection from syn processing path and provides the skb
to the merged function at the same time.
'send reset on unknown mptcp join token' is added in next patch.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index fb3a7750f623..9e8a6c1aa019 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6799,18 +6799,13 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, /* Note: tcp_v6_init_req() might override ir_iif for link locals */ inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb); - af_ops->init_req(req, sk, skb); - - if (security_inet_conn_request(sk, skb, req)) + dst = af_ops->route_req(sk, skb, &fl, req); + if (!dst) goto drop_and_free; if (tmp_opt.tstamp_ok) tcp_rsk(req)->ts_off = af_ops->init_ts_off(net, skb); - dst = af_ops->route_req(sk, &fl, req); - if (!dst) - goto drop_and_free; - if (!want_cookie && !isn) { /* Kill the following clause, if you dislike this way. */ if (!net->ipv4.sysctl_tcp_syncookies && |