examples/ipsec-secgw: fix inline modes

examples/ipsec-secgw: fix inline modes

Application ipsec-secgw is not working for IPv4 transport mode and for
IPv6 both transport and tunnel mode.

IPv6 tunnel mode is not working due to wrongly assigned fields of
security association patterns, as it was IPv4, during creation of
inline crypto session.

IPv6 and IPv4 transport mode is iterating through security capabilities
until it reaches tunnel, which causes session to be created as tunnel,
instead of transport. Another issue, is that config file does not
provide source and destination ip addresses for transport mode, which
are required by NIC to perform inline crypto. It uses default addresses
stored in security association (all zeroes), which causes dropped
packages.

To fix that, reorganization of code in create_session() is needed,
to behave appropriately to given protocol (IPv6/IPv4). Change in
iteration through security capabilities is also required, to check
for expected mode (not only tunnel).

For lack of addresses issue, some resolving mechanism is needed.
Approach is to store addresses in security association, as it is
for tunnel mode. Difference is that they are obtained from sp rules,
instead of config file. To do that, sp[4/6]_spi_present() function
is used to find addresses based on spi value, and then stored in
corresponding sa rule. This approach assumes, that every sp rule
for inline crypto have valid addresses, as well as range of addresses
is not supported.

New flags for ipsec_sa structure are required to distinguish between
IPv4 and IPv6 transport modes. Because of that, there is need to
change all checks done on these flags, so they work as expected.

Fixes: ec17993a145a ("examples/ipsec-secgw: support security offload")
Fixes: 9a0752f498d2 ("net/ixgbe: enable inline IPsec")
Cc: stable@dpdk.org
Signed-off-by: Mariusz Drost <mariuszx.drost@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
Tested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>