diff options
| author | Matthieu Baerts (NGI0) <matttbe@kernel.org> | 2024-09-09 22:09:23 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-09-11 15:57:50 -0700 |
| commit | 27069e7cb3d1cea9377069266acf19b9cc5ad0ae (patch) | |
| tree | b2b59e53ce7fee633efeb019b4903cba0b649ac8 /net/mptcp/protocol.h | |
| parent | 6982826fe5e53ef115836de7dd397bd970030937 (diff) | |
mptcp: disable active MPTCP in case of blackhole
An MPTCP firewall blackhole can be detected if the following SYN
retransmission after a fallback to "plain" TCP is accepted.
In case of blackhole, a similar technique to the one in place with TFO
is now used: MPTCP can be disabled for a certain period of time, 1h by
default. This time period will grow exponentially when more blackhole
issues get detected right after MPTCP is re-enabled and will reset to
the initial value when the blackhole issue goes away.
The blackhole period can be modified thanks to a new sysctl knob:
blackhole_timeout. Two new MIB counters help understanding what's
happening:
- 'Blackhole', incremented when a blackhole is detected.
- 'MPCapableSYNTXDisabled', incremented when an MPTCP connection
directly falls back to TCP during the blackhole period.
Because the technique is inspired by the one used by TFO, an important
part of the new code is similar to what can find in tcp_fastopen.c, with
some adaptations to the MPTCP case.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/57
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240909-net-next-mptcp-fallback-x-mpc-v1-3-da7ebb4cd2a3@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mptcp/protocol.h')
| -rw-r--r-- | net/mptcp/protocol.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 302bd808b839..74417aae08d0 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -531,7 +531,8 @@ struct mptcp_subflow_context { valid_csum_seen : 1, /* at least one csum validated */ is_mptfo : 1, /* subflow is doing TFO */ close_event_done : 1, /* has done the post-closed part */ - __unused : 9; + mpc_drop : 1, /* the MPC option has been dropped in a rtx */ + __unused : 8; bool data_avail; bool scheduled; u32 remote_nonce; @@ -697,6 +698,11 @@ unsigned int mptcp_stale_loss_cnt(const struct net *net); unsigned int mptcp_close_timeout(const struct sock *sk); int mptcp_get_pm_type(const struct net *net); const char *mptcp_get_scheduler(const struct net *net); + +void mptcp_active_disable(struct sock *sk); +bool mptcp_active_should_disable(struct sock *ssk); +void mptcp_active_enable(struct sock *sk); + void mptcp_get_available_schedulers(char *buf, size_t maxlen); void __mptcp_subflow_fully_established(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow, |