[PATCH v2 mptcp-next 0/8] mptcp: refactor active backup

[Paolo Abeni <pabeni@redhat.com>]

This series addresses a bunch of issues somewhat related to active
backup handling. The most visible functial issue addressed here is:

https://github.com/multipath-tcp/mptcp_net-next/issues/191

This series also add some specific self-tests, to cover both
active-backup switch-over and proper usage of backup link.

A new netns parameter is introduced:

stale_loss_cnt - the max amount of mptcp rtx timeouts with no progresses
        and outstanding data over a single subflow needed to declare
        such subflow 'stale': no more data will be queue until some ack
        is observed.

Changes from v1:
 - stale_loss_cnt is now configurable via sysctl
 - addressed buglet noted by Mat on v1
 - fixed timeout update issues in patches 1-2
 - fixed splat in __mptcp_clean_una() on reinection
   - the new self-tests are now less unstable

Paolo Abeni (8):
  mptcp: more accurate timeout
  mptcp: less aggressive retransmission stragegy
  mptcp: handle pending data on closed subflow
  mptcp: cleanup sysctl data and helpers
  mptcp: faster active backup recovery
  mptcp: add mibs for stale subflows processing
  mptcp: backup flag from incoming MPJ ack option
  selftests: mptcp: add testcase for active-back

 Documentation/networking/mptcp-sysctl.rst     |  12 +
 net/mptcp/ctrl.c                              |  26 ++-
 net/mptcp/mib.c                               |   2 +
 net/mptcp/mib.h                               |   2 +
 net/mptcp/options.c                           |   8 +-
 net/mptcp/pm.c                                |  21 ++
 net/mptcp/pm_netlink.c                        |  37 +++
 net/mptcp/protocol.c                          | 187 +++++++++++----
 net/mptcp/protocol.h                          |  31 ++-
 net/mptcp/subflow.c                           |   6 +-
 .../testing/selftests/net/mptcp/mptcp_join.sh | 215 +++++++++++++++---
 11 files changed, 459 insertions(+), 88 deletions(-)

-- 
2.26.3