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| author | Paolo Abeni <pabeni@redhat.com> | 2020-11-03 11:05:05 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-04 17:45:53 -0800 |
| commit | 5a369ca64364b49caff424d2f988901bc7658b6d (patch) | |
| tree | 4af5d3c6d1086f2d64adde122e2b780eb326011f /net/mptcp/protocol.c | |
| parent | 65f49fe72f9e4063b96c78de62f3ff9a3384164e (diff) | |
| download | linux-stable-5a369ca64364b49caff424d2f988901bc7658b6d.tar.gz linux-stable-5a369ca64364b49caff424d2f988901bc7658b6d.tar.bz2 linux-stable-5a369ca64364b49caff424d2f988901bc7658b6d.zip | |
tcp: propagate MPTCP skb extensions on xmit splits
When the TCP stack splits a packet on the write queue, the tail
half currently lose the associated skb extensions, and will not
carry the DSM on the wire.
The above does not cause functional problems and is allowed by
the RFC, but interact badly with GRO and RX coalescing, as possible
candidates for aggregation will carry different TCP options.
This change tries to improve the MPTCP behavior, propagating the
skb extensions on split.
Additionally, we must prevent the MPTCP stack from updating the
mapping after the split occur: that will both violate the RFC and
fool the reader.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mptcp/protocol.c')
| -rw-r--r-- | net/mptcp/protocol.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index f5bacfc55006..25d12183d1ca 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -771,8 +771,11 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq, if (!tcp_skb_can_collapse_to(skb)) return false; - /* can collapse only if MPTCP level sequence is in order */ - return mpext && mpext->data_seq + mpext->data_len == write_seq; + /* can collapse only if MPTCP level sequence is in order and this + * mapping has not been xmitted yet + */ + return mpext && mpext->data_seq + mpext->data_len == write_seq && + !mpext->frozen; } static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk, |