[dpdk-dev] [PATCH v2] net: fix build with gcc 4.4.7 and strict aliasing

[Daniel Mrzyglod]

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(-)

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2.5.0