[PATCH] samples: bpf: add an explict comment to handle nested vlan tagging.

From: Muhammad Falak R Wani
Date: Mon Aug 09 2021 - 03:01:11 EST


A codeblock for handling nested vlan trips newbies into thinking it as
duplicate code. Explicitly add a comment to clarify.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@xxxxxxxxx>
---
samples/bpf/xdp1_kern.c | 2 ++
samples/bpf/xdp2_kern.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/samples/bpf/xdp1_kern.c b/samples/bpf/xdp1_kern.c
index 34b64394ed9c..f0c5d95084de 100644
--- a/samples/bpf/xdp1_kern.c
+++ b/samples/bpf/xdp1_kern.c
@@ -57,6 +57,7 @@ int xdp_prog1(struct xdp_md *ctx)

h_proto = eth->h_proto;

+ /* Handle VLAN tagged packet */
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;

@@ -66,6 +67,7 @@ int xdp_prog1(struct xdp_md *ctx)
return rc;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
+ /* Handle double VLAN tagged packet */
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;

diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c
index c787f4b49646..d8a64ab077b0 100644
--- a/samples/bpf/xdp2_kern.c
+++ b/samples/bpf/xdp2_kern.c
@@ -73,6 +73,7 @@ int xdp_prog1(struct xdp_md *ctx)

h_proto = eth->h_proto;

+ /* Handle VLAN tagged packet */
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;

@@ -82,6 +83,7 @@ int xdp_prog1(struct xdp_md *ctx)
return rc;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
+ /* Handle double VLAN tagged packet */
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;

--
2.17.1