[PATCH bpf-next] samples/bpf: xdp1 and xdp2 reduce XDPBUFSIZE to 60

[Jesper Dangaard Brouer <brouer@redhat.com>]

Default samples/pktgen scripts send 60 byte packets as hardware
adds 4-bytes FCS checksum, which fulfils minimum Ethernet 64 bytes
frame size.

XDP layer will not necessary have access to the 4-bytes FCS checksum.

This leads to bpf_xdp_load_bytes() failing as it tries to copy
64-bytes from an XDP packet that only have 60-bytes available.

Fixes: 772251742262 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
 samples/bpf/xdp1_kern.c |    2 +-
 samples/bpf/xdp2_kern.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/bpf/xdp1_kern.c b/samples/bpf/xdp1_kern.c
index 0a5c704badd0..d91f27cbcfa9 100644
--- a/samples/bpf/xdp1_kern.c
+++ b/samples/bpf/xdp1_kern.c
@@ -39,7 +39,7 @@ static int parse_ipv6(void *data, u64 nh_off, void *data_end)
 	return ip6h->nexthdr;
 }
 
-#define XDPBUFSIZE	64
+#define XDPBUFSIZE	60
 SEC("xdp.frags")
 int xdp_prog1(struct xdp_md *ctx)
 {
diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c
index 67804ecf7ce3..8bca674451ed 100644
--- a/samples/bpf/xdp2_kern.c
+++ b/samples/bpf/xdp2_kern.c
@@ -55,7 +55,7 @@ static int parse_ipv6(void *data, u64 nh_off, void *data_end)
 	return ip6h->nexthdr;
 }
 
-#define XDPBUFSIZE	64
+#define XDPBUFSIZE	60
 SEC("xdp.frags")
 int xdp_prog1(struct xdp_md *ctx)
 {