Octeontx2-af: Skip overlap check for SPI field

[ Upstream commit 8c5d9598 ]

Octeontx2/CN10K silicon supports generating a 256-bit key per packet.
The specific fields to be extracted from a packet for key generation
are configurable via a Key Extraction (MKEX) Profile.

The AF driver scans the configured extraction profile to ensure that
fields from upper layers do not overwrite fields from lower layers in
the key.

Example Packet Field Layout:
LA: DMAC + SMAC
LB: VLAN
LC: IPv4/IPv6
LD: TCP/UDP

Valid MKEX Profile Configuration:

LA   -> DMAC   -> key_offset[0-5]
LC   -> SIP    -> key_offset[20-23]
LD   -> SPORT  -> key_offset[30-31]

Invalid MKEX profile configuration:

LA   -> DMAC   -> key_offset[0-5]
LC   -> SIP    -> key_offset[20-23]
LD   -> SPORT  -> key_offset[2-3]  // Overlaps with DMAC field

In another scenario, if the MKEX profile is configured to extract
the SPI field from both AH and ESP headers at the same key offset,
the driver rejecting this configuration. In a regular traffic,
ipsec packet will be having either AH(LD) or ESP (LE). This patch
relaxes the check for the same.

Fixes: 12aa0a3b ("octeontx2-af: Harden rule validation.")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://patch.msgid.link/20250820063919.1463518-1-hkelam@marvell.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>