|SUCCESS| [v3] net/ice: fix L2TPv2 outer MAC in training packet

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/162961

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-04-09

827f42cde4a1 (hypothetical - actual sha will differ)
Author: Shaiq Wani <shaiq.wani at intel.com>
net/ice: fix L2TPv2 outer MAC in training packet

In ice_fdir_get_gen_prgm_pkt() there are two pointers into the
training-packet buffer:

pkt  - start of the full packet (outer Ethernet header, offset 0)
loc  - start of the current protocol segment; equals pkt for
       non-tunnel flows but points past the tunnel header for
       tunnel flows

The L2TPv2 cases wrote the outer source and destination MAC addresses
through loc.  For non-tunnel L2TPv2, loc == pkt so this happened to
work, but it is semantically wrong: outer Ethernet fields must always
be written relative to pkt so the code remains correct regardless of
the tunnel/non-tunnel path taken.

Replace loc with pkt in the four L2TPv2 MAC-insertion case blocks
(IPv4 control, IPv4 data/PPP, IPv6 control, IPv6 data/PPP)

Fixes: bf662653976e ("net/ice/base: support L2TPv2 flow rule")
Signed-off-by: Shaiq Wani <shaiq.wani at intel.com>

---
 drivers/net/intel/ice/base/ice_fdir.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/intel/ice/base/ice_fdir.c 
b/drivers/net/intel/ice/base/ice_fdir.c
index 2c0cb99854..1846fbc515 100644
--- a/drivers/net/intel/ice/base/ice_fdir.c
+++ b/drivers/net/intel/ice/base/ice_fdir.c
@@ -3835,6 +3835,12 @@ ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, struct 
ice_fdir_fltr *input,
 	u16 pos;
 	u16 offset;
 
+	/* pkt  = start of full packet buffer (outer Ethernet header, 
offset 0).
+	 * loc  = start of current protocol segment; equals pkt for 
non-tunnel
+	 *        flows, but points past the tunnel header for tunnel flows.
+	 * Use pkt for outer L2 fields, loc for the active segment.
+	 */
+

Does this comment belong above the variable declarations instead of 
below them? The DPDK coding style typically places block comments 
immediately before the code they describe. Having it after the variable 
declarations is unusual.

[ ... ]

@@ -4599,16 +4605,16 @@ ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, 
struct ice_fdir_fltr *input,
 				     input->ip.v6.tc);
 		break;
 	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2_CONTROL:
-		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
-		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
+		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
+		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
 					input->ext_data_outer.src_mac);
 		ice_pkt_insert_u16(loc, ICE_IPV4_L2TPV2_LEN_SESS_ID_OFFSET,
 				   input->l2tpv2_data.session_id);
 		break;
 	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2:
 	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2_PPP:
-		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
-		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
+		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
+		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
 					input->ext_data_outer.src_mac);
 		flags_version = BE16_TO_CPU(input->l2tpv2_data.flags_version);
 		if (flags_version & ICE_L2TPV2_FLAGS_LEN) {
@@ -4622,16 +4628,16 @@ ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, 
struct ice_fdir_fltr *input,
 		}
 		break;
 	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2_CONTROL:
-		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
-		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
+		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
+		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
 					input->ext_data_outer.src_mac);
 		ice_pkt_insert_u16(loc, ICE_IPV6_L2TPV2_LEN_SESS_ID_OFFSET,
 				   input->l2tpv2_data.session_id);
 		break;
 	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2:
 	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2_PPP:
-		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
-		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
+		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
+		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
 					input->ext_data_outer.src_mac);
 		flags_version = BE16_TO_CPU(input->l2tpv2_data.flags_version);
 		if (flags_version & ICE_L2TPV2_FLAGS_LEN) {