[PATCH bpf-next 2/2] samples/bpf: fixup xdp_redirect_map tool to be able to support xdp multibuffer

[Tariq Toukan <tariqt@xxxxxxxxxx>]

From: Nimrod Oren <noren@xxxxxxxxxx>

Expand the xdp multi-buffer support to xdp_redirect_map tool.
Similar to what's done in commit
772251742262 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
and its fix commit
7a698edf954c ("samples/bpf: Fix MAC address swapping in xdp2_kern").

Signed-off-by: Nimrod Oren <noren@xxxxxxxxxx>
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
---
 samples/bpf/xdp_redirect_map.bpf.c | 31 ++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/samples/bpf/xdp_redirect_map.bpf.c b/samples/bpf/xdp_redirect_map.bpf.c
index 8557c278df77..dd034fdff1a9 100644
--- a/samples/bpf/xdp_redirect_map.bpf.c
+++ b/samples/bpf/xdp_redirect_map.bpf.c
@@ -35,15 +35,20 @@ struct {
 /* store egress interface mac address */
 const volatile __u8 tx_mac_addr[ETH_ALEN];
 
+#define XDPBUFSIZE	64
 static __always_inline int xdp_redirect_map(struct xdp_md *ctx, void *redirect_map)
 {
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
+	__u8 pkt[XDPBUFSIZE] = {};
+	void *data_end = &pkt[XDPBUFSIZE-1];
+	void *data = pkt;
 	u32 key = bpf_get_smp_processor_id();
 	struct ethhdr *eth = data;
 	struct datarec *rec;
 	u64 nh_off;
 
+	if (bpf_xdp_load_bytes(ctx, 0, pkt, sizeof(pkt)))
+		return XDP_DROP;
+
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
 		return XDP_DROP;
@@ -53,30 +58,37 @@ static __always_inline int xdp_redirect_map(struct xdp_md *ctx, void *redirect_m
 		return XDP_PASS;
 	NO_TEAR_INC(rec->processed);
 	swap_src_dst_mac(data);
+	if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt)))
+		return XDP_DROP;
+
 	return bpf_redirect_map(redirect_map, 0, 0);
 }
 
-SEC("xdp")
+SEC("xdp.frags")
 int xdp_redirect_map_general(struct xdp_md *ctx)
 {
 	return xdp_redirect_map(ctx, &tx_port_general);
 }
 
-SEC("xdp")
+SEC("xdp.frags")
 int xdp_redirect_map_native(struct xdp_md *ctx)
 {
 	return xdp_redirect_map(ctx, &tx_port_native);
 }
 
-SEC("xdp/devmap")
+SEC("xdp.frags/devmap")
 int xdp_redirect_map_egress(struct xdp_md *ctx)
 {
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
+	__u8 pkt[XDPBUFSIZE] = {};
+	void *data_end = &pkt[XDPBUFSIZE-1];
+	void *data = pkt;
 	u8 *mac_addr = (u8 *) tx_mac_addr;
 	struct ethhdr *eth = data;
 	u64 nh_off;
 
+	if (bpf_xdp_load_bytes(ctx, 0, pkt, sizeof(pkt)))
+		return XDP_DROP;
+
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
 		return XDP_DROP;
@@ -84,11 +96,14 @@ int xdp_redirect_map_egress(struct xdp_md *ctx)
 	barrier_var(mac_addr); /* prevent optimizing out memcpy */
 	__builtin_memcpy(eth->h_source, mac_addr, ETH_ALEN);
 
+	if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt)))
+		return XDP_DROP;
+
 	return XDP_PASS;
 }
 
 /* Redirect require an XDP bpf_prog loaded on the TX device */
-SEC("xdp")
+SEC("xdp.frags")
 int xdp_redirect_dummy_prog(struct xdp_md *ctx)
 {
 	return XDP_PASS;
-- 
2.34.1