These patches address a bug in the byte ordering of MPTCP checksums on
little-endian architectures. The __sum16 type is always big endian, but
was being cast to u16 and then byte-swapped (on little-endian archs)
when reading/writing the checksum field in MPTCP option headers.

MPTCP checksums are off by default, but are enabled if one or both peers
request it in the SYN/SYNACK handshake.

The corrected code is verified to interoperate between big-endian and
little-endian machines.

Patch 1 fixes the checksum byte order, patch 2 partially mitigates
interoperation with peers sending bad checksums by falling back to TCP
instead of resetting the connection.

Mat Martineau (1):
  mptcp: Do TCP fallback on early DSS checksum failure

Paolo Abeni (1):
  mptcp: fix checksum byte order

 net/mptcp/options.c  | 36 ++++++++++++++++++++++++------------
 net/mptcp/protocol.h |  5 +++--
 net/mptcp/subflow.c  | 23 +++++++++++++++++++----
 3 files changed, 46 insertions(+), 18 deletions(-)


base-commit: edf410cb74dc612fd47ef5be319c5a0bcd6e6ccd
-- 
2.36.1