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
