On Tue, 24 Nov 2015 17:31:17 +0100
Daniel Mrzyglod <danielx.t.mrzyglod at intel.com> wrote:
> This fix is for IPv6 checksum offload error on RHEL65.
> Any optimalisation above -O0 provide error in IPv6 checksum
> flag "-fstrict-aliasing" is default for optimalisation above -O0.
> The solution is to add typedef with __attribute__((__may_alias__) for
> uint16_t.
>
> Step 1 : start testpmd
> ./testpmd -c 0x6 -n 4 -- -i --portmask=0x3 --disable-hw-vlan
> --enable-rx-cksum --crc-strip --txqflags=0
>
> Step 2 : settings and start
> set verbose 1
> set fwd csum
> start
>
> Step 3 : send scapy with bad checksum IPv6/TCP packet
> Ether(src="52:00:00:00:00:00",
> dst="90:e2:ba:4a:33:5d")/IPv6(src="::1")/TCP(chksum=0xf)/("X"*46)
>
> Step 4 : Recieved packets:
> RESULTS:
> IPv6/TCP': ['0xd41'] or other unexpected.
>
> EXPECTED RESULTS:
> IPv6/TCP': ['0x9f5e']
>
> Daniel Mrzyglod (1):
> net: fix build with gcc 4.4.7 and strict aliasing
>
> lib/librte_net/rte_ip.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
An alternative way of fixing it (without resorting to attributes) would
be to use a union.
