diff options
| author | Florian Westphal <fw@strlen.de> | 2021-09-24 14:12:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-25 11:36:51 +0100 |
| commit | 0d199e4363b482badcedba764e2aceab53a4a10a (patch) | |
| tree | 3faad2f883c63092c4f59dc262e56acfb6c5bf3e /net/mptcp/options.c | |
| parent | 8765de69e7a18d7d17b9c367ae9ca653bc50e8b0 (diff) | |
mptcp: do not shrink snd_nxt when recovering
When recovering after a link failure, snd_nxt should not be set to a
lower value. Else, update of snd_nxt is broken because:
msk->snd_nxt += ret; (where ret is number of bytes sent)
assumes that snd_nxt always moves forward.
After reduction, its possible that snd_nxt update gets out of sync:
dfrag we just sent might have had a data sequence number even past
recovery_snd_nxt.
This change factors the common msk state update to a helper
and updates snd_nxt based on the current dfrag data sequence number.
The conditional is required for the recovery phase where we may
re-transmit old dfrags that are before current snd_nxt.
After this change, snd_nxt only moves forward and covers all in-sequence
data that was transmitted.
recovery_snd_nxt is retained to detect when recovery has completed.
Fixes: 1e1d9d6f119c5 ("mptcp: handle pending data on closed subflow")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/options.c')
| -rw-r--r-- | net/mptcp/options.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index c41273cefc51..1ec6529c4326 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1019,11 +1019,9 @@ static void ack_update_msk(struct mptcp_sock *msk, old_snd_una = msk->snd_una; new_snd_una = mptcp_expand_seq(old_snd_una, mp_opt->data_ack, mp_opt->ack64); - /* ACK for data not even sent yet and even above recovery bound? Ignore.*/ - if (unlikely(after64(new_snd_una, snd_nxt))) { - if (!msk->recovery || after64(new_snd_una, msk->recovery_snd_nxt)) - new_snd_una = old_snd_una; - } + /* ACK for data not even sent yet? Ignore.*/ + if (unlikely(after64(new_snd_una, snd_nxt))) + new_snd_una = old_snd_una; new_wnd_end = new_snd_una + tcp_sk(ssk)->snd_wnd; |