> > In some situations, we would get several ip fragments, which total
> > data length is less than min_ip_len(64) and padding with zeros.
> > We simulated intermediate fragments by modifying the MTU.
> > To illustrate the problem, we simplify the packet format and
> > ignore the impact of the packet header.In namespace2,
> > a packet whose data length is 1520 is sent.
> > When the packet passes tap2, the packet is divided into two
> > fragments: fragment A and B, similar to (1520 = 1510 + 10).
> > When the packet passes tap3, the larger fragment packet A is
> > divided into two fragments A1 and A2, similar to (1510 = 1500 + 10).
> > Finally, the bond interface receives three fragments:
> > A1, A2, and B (1520 = 1500 + 10 + 10).
> > One fragmented packet A2 is smaller than the minimum Ethernet
> > frame length, so it needs to be padded.
> >
> > |---------------------------------------------------|
> > | HOST |
> > | |--------------| |----------------------------| |
> > | | ns2 | | |--------------| | |
> > | | |--------| | | |--------| |--------| | |
> > | | | tap1 | | | | tap2 | ns1| tap3 | | |
> > | | |mtu=1510| | | |mtu=1510| |mtu=1500| | |
> > | |--|1.1.1.1 |--| |--|1.1.1.2 |----|2.1.1.1 |--| |
> > | |--------| |--------| |--------| |
> > | | | | |
> > | |-----------------| | |
> > | | |
> > | |--------| |
> > | | bond | |
> > |--------------------------------------|mtu=1500|---|
> > |--------|
> >
> > When processing the preceding packets above,
> > DPDK would aggregate fragmented packets A2 and B.
> > And error packets are generated, which padding(zero)
> > is displayed in the middle of the packet.
> >
> > A2 + B:
> > 0000 fa 16 3e 9f fb 82 fa 47 b2 57 dc 20 08 00 45 00
> > 0010 00 33 b4 66 00 ba 3f 01 c1 a5 01 01 01 01 02 01
> > 0020 01 02 c0 c1 c2 c3 c4 c5 c6 c7 00 00 00 00 00 00
> > 0030 00 00 00 00 00 00 00 00 00 00 00 00 c8 c9 ca cb
> > 0040 cc cd ce cf d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db
> > 0050 dc dd de df e0 e1 e2 e3 e4 e5 e6
> >
> > So, we would calculate the length of padding, and remove
> > the padding in pkt_len and data_len before aggregation.
> > And also we have the fix for both ipv4 and ipv6.
> >
> > Fixes: 7f0983ee331c ("ip_frag: check fragment length of incoming packet")
> > Cc: sta...@dpdk.org
> >
> > Signed-off-by: Yicai Lu <luyi...@huawei.com>
>
> Acked-by: Konstantin Ananyev <konstantin.anan...@intel.com>
Applied, thanks
