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| author |   Jeffrey Altman <jaltman@auristor.com> | 2019-04-12 16:34:16 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-04-12 16:57:23 -0700 |
| commit | 1a2391c30c0b9d041bc340f68df81d49c53546cc (patch) | |
| tree | adec0da77205b01e590914e28aca0930926f9949 /net/rxrpc/ar-internal.h | |
| parent | rxrpc: Trace received connection aborts (diff) | |
| download | linux-dev-1a2391c30c0b9d041bc340f68df81d49c53546cc.tar.xz linux-dev-1a2391c30c0b9d041bc340f68df81d49c53546cc.zip | |
rxrpc: Fix detection of out of order acks
The rxrpc packet serial number cannot be safely used to compute out of
order ack packets for several reasons:
1. The allocation of serial numbers cannot be assumed to imply the order
by which acks are populated and transmitted. In some rxrpc
implementations, delayed acks and ping acks are transmitted
asynchronously to the receipt of data packets and so may be transmitted
out of order. As a result, they can race with idle acks.
2. Serial numbers are allocated by the rxrpc connection and not the call
and as such may wrap independently if multiple channels are in use.
In any case, what matters is whether the ack packet provides new
information relating to the bounds of the window (the firstPacket and
previousPacket in the ACK data).
Fix this by discarding packets that appear to wind back the window bounds
rather than on serial number procession.
Fixes: 298bc15b2079 ("rxrpc: Only take the rwind and mtu values from latest ACK")
Signed-off-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | net/rxrpc/ar-internal.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 4b1a534d290a..062ca9dc29b8 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -654,6 +654,7 @@ struct rxrpc_call { u8 ackr_reason; /* reason to ACK */ u16 ackr_skew; /* skew on packet being ACK'd */ rxrpc_serial_t ackr_serial; /* serial of packet being ACK'd */ + rxrpc_serial_t ackr_first_seq; /* first sequence number received */ rxrpc_seq_t ackr_prev_seq; /* previous sequence number received */ rxrpc_seq_t ackr_consumed; /* Highest packet shown consumed */ rxrpc_seq_t ackr_seen; /* Highest packet shown seen */ |