[PATCH net-next 0/4] net: IP defrag: use rbtrees in IPv6 defragmentation

[Peter Oskolkov <posk@google.com>]

Currently, IPv6 defragmentation code drops non-last fragments that
are smaller than 1280 bytes: see
commit 0ed4229b08c1 ("ipv6: defrag: drop non-last frags smaller than min mtu")

This behavior is not specified in IPv6 RFCs and appears to break compatibility
with some IPv6 implementations, as reported here:
https://www.spinics.net/lists/netdev/msg543846.html

This patchset contains four patches:
- patch 1 moves rbtree-related code from IPv4 to files shared b/w
IPv4/IPv6
- patch 2 changes IPv6 defragmenation code to use rbtrees for defrag
queue
- patch 3 changes nf_conntrack IPv6 defragmentation code to use rbtrees
- patch 4 changes ip_defrag selftest to test changes made in the
previous three patches.

Along the way, the 1280-byte restrictions are removed.

I plan to introduce similar changes to 6lowpan defragmentation code
once I figure out how to test it.

Peter Oskolkov (4):
  net: IP defrag: encapsulate rbtree defrag code into callable functions
  net: IP6 defrag: use rbtrees for IPv6 defrag
  net: IP6 defrag: use rbtrees in nf_conntrack_reasm.c
  selftests: net: ip_defrag:  cover new IPv6 defrag behavior

 include/net/inet_frag.h                  |  16 +-
 include/net/ipv6_frag.h                  |  11 +-
 net/ipv4/inet_fragment.c                 | 293 +++++++++++++++++++++++
 net/ipv4/ip_fragment.c                   | 289 +++-------------------
 net/ipv6/netfilter/nf_conntrack_reasm.c  | 260 ++++++--------------
 net/ipv6/reassembly.c                    | 233 +++++-------------
 tools/testing/selftests/net/ip_defrag.c  |  69 +++---
 tools/testing/selftests/net/ip_defrag.sh |  16 ++
 8 files changed, 527 insertions(+), 660 deletions(-)

-- 
2.20.1.321.g9e740568ce-goog