Merge branch 'xdp-cleanups'

Brenden Blanco says:

====================
misc cleanups for xdp

This addresses several of the non-blocking comments left over from the
xdp patch set. See individual patches for details.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -535,9 +535,11 @@ void mlx4_en_destroy_rx_ring(struct mlx4_en_priv *priv,
 {
 	struct mlx4_en_dev *mdev = priv->mdev;
 	struct mlx4_en_rx_ring *ring = *pring;
+	struct bpf_prog *old_prog;
 
-	if (ring->xdp_prog)
-		bpf_prog_put(ring->xdp_prog);
+	old_prog = READ_ONCE(ring->xdp_prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, size * stride + TXBB_SIZE);
 	vfree(ring->rx_info);
 	ring->rx_info = NULL;

net/core/rtnetlink.c

@@ -2109,6 +2109,10 @@ static int do_setlink(const struct sk_buff *skb,
 		if (err < 0)
 			goto errout;
 
+		if (xdp[IFLA_XDP_ATTACHED]) {
+			err = -EINVAL;
+			goto errout;
+		}
 		if (xdp[IFLA_XDP_FD]) {
 			err = dev_change_xdp_fd(dev,
 						nla_get_s32(xdp[IFLA_XDP_FD]));

samples/bpf/xdp1_kern.c

@@ -14,7 +14,7 @@
 #include <linux/ipv6.h>
 #include "bpf_helpers.h"
 
-struct bpf_map_def SEC("maps") dropcnt = {
+struct bpf_map_def SEC("maps") rxcnt = {
 	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
 	.key_size = sizeof(u32),
 	.value_size = sizeof(long),
@@ -49,7 +49,7 @@ int xdp_prog1(struct xdp_md *ctx)
 	long *value;
 	u16 h_proto;
 	u64 nh_off;
-	u32 index;
+	u32 ipproto;
 
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
@@ -77,13 +77,13 @@ int xdp_prog1(struct xdp_md *ctx)
 	}
 
 	if (h_proto == htons(ETH_P_IP))
-		index = parse_ipv4(data, nh_off, data_end);
+		ipproto = parse_ipv4(data, nh_off, data_end);
 	else if (h_proto == htons(ETH_P_IPV6))
-		index = parse_ipv6(data, nh_off, data_end);
+		ipproto = parse_ipv6(data, nh_off, data_end);
 	else
-		index = 0;
+		ipproto = 0;
 
-	value = bpf_map_lookup_elem(&dropcnt, &index);
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
 	if (value)
 		*value += 1;
 

samples/bpf/xdp2_kern.c

@@ -14,7 +14,7 @@
 #include <linux/ipv6.h>
 #include "bpf_helpers.h"
 
-struct bpf_map_def SEC("maps") dropcnt = {
+struct bpf_map_def SEC("maps") rxcnt = {
 	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
 	.key_size = sizeof(u32),
 	.value_size = sizeof(long),
@@ -65,7 +65,7 @@ int xdp_prog1(struct xdp_md *ctx)
 	long *value;
 	u16 h_proto;
 	u64 nh_off;
-	u32 index;
+	u32 ipproto;
 
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
@@ -93,17 +93,17 @@ int xdp_prog1(struct xdp_md *ctx)
 	}
 
 	if (h_proto == htons(ETH_P_IP))
-		index = parse_ipv4(data, nh_off, data_end);
+		ipproto = parse_ipv4(data, nh_off, data_end);
 	else if (h_proto == htons(ETH_P_IPV6))
-		index = parse_ipv6(data, nh_off, data_end);
+		ipproto = parse_ipv6(data, nh_off, data_end);
 	else
-		index = 0;
+		ipproto = 0;
 
-	value = bpf_map_lookup_elem(&dropcnt, &index);
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
 	if (value)
 		*value += 1;
 
-	if (index == 17) {
+	if (ipproto == IPPROTO_UDP) {
 		swap_src_dst_mac(data);
 		rc = XDP_TX;
 	}