devmap: Rename ifindex member in bpf_redirect_info

The bpf_redirect_info struct has an 'ifindex' member which was named back
when the redirects could only target egress interfaces. Now that we can
also redirect to sockets and CPUs, this is a bit misleading, so rename the
member to tgt_index.

Reorder the struct members so we can have 'tgt_index' and 'tgt_value' next
to each other in a subsequent patch.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

include/linux/filter.h

@@ -578,8 +578,8 @@ struct bpf_skb_data_end {
 };
 
 struct bpf_redirect_info {
-	u32 ifindex;
 	u32 flags;
+	u32 tgt_index;
 	struct bpf_map *map;
 	struct bpf_map *map_to_flush;
 	u32 kern_flags;

net/core/filter.c

@@ -2158,8 +2158,8 @@ BPF_CALL_2(bpf_redirect, u32, ifindex, u64, flags)
 	if (unlikely(flags & ~(BPF_F_INGRESS)))
 		return TC_ACT_SHOT;
 
-	ri->ifindex = ifindex;
 	ri->flags = flags;
+	ri->tgt_index = ifindex;
 
 	return TC_ACT_REDIRECT;
 }
@@ -2169,8 +2169,8 @@ int skb_do_redirect(struct sk_buff *skb)
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 	struct net_device *dev;
 
-	dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex);
-	ri->ifindex = 0;
+	dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->tgt_index);
+	ri->tgt_index = 0;
 	if (unlikely(!dev)) {
 		kfree_skb(skb);
 		return -EINVAL;
@@ -3488,11 +3488,11 @@ xdp_do_redirect_slow(struct net_device *dev, struct xdp_buff *xdp,
 		     struct bpf_prog *xdp_prog, struct bpf_redirect_info *ri)
 {
 	struct net_device *fwd;
-	u32 index = ri->ifindex;
+	u32 index = ri->tgt_index;
 	int err;
 
 	fwd = dev_get_by_index_rcu(dev_net(dev), index);
-	ri->ifindex = 0;
+	ri->tgt_index = 0;
 	if (unlikely(!fwd)) {
 		err = -EINVAL;
 		goto err;
@@ -3604,11 +3604,11 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
 			       struct bpf_prog *xdp_prog, struct bpf_map *map,
 			       struct bpf_redirect_info *ri)
 {
-	u32 index = ri->ifindex;
+	u32 index = ri->tgt_index;
 	void *fwd = NULL;
 	int err;
 
-	ri->ifindex = 0;
+	ri->tgt_index = 0;
 	WRITE_ONCE(ri->map, NULL);
 
 	fwd = __xdp_map_lookup_elem(map, index);
@@ -3651,11 +3651,11 @@ static int xdp_do_generic_redirect_map(struct net_device *dev,
 				       struct bpf_map *map)
 {
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
-	u32 index = ri->ifindex;
+	u32 index = ri->tgt_index;
 	void *fwd = NULL;
 	int err = 0;
 
-	ri->ifindex = 0;
+	ri->tgt_index = 0;
 	WRITE_ONCE(ri->map, NULL);
 
 	fwd = __xdp_map_lookup_elem(map, index);
@@ -3695,14 +3695,14 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 {
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
 	struct bpf_map *map = READ_ONCE(ri->map);
-	u32 index = ri->ifindex;
+	u32 index = ri->tgt_index;
 	struct net_device *fwd;
 	int err = 0;
 
 	if (map)
 		return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog,
 						   map);
-	ri->ifindex = 0;
+	ri->tgt_index = 0;
 	fwd = dev_get_by_index_rcu(dev_net(dev), index);
 	if (unlikely(!fwd)) {
 		err = -EINVAL;
@@ -3730,8 +3730,8 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags)
 	if (unlikely(flags))
 		return XDP_ABORTED;
 
-	ri->ifindex = ifindex;
 	ri->flags = flags;
+	ri->tgt_index = ifindex;
 	WRITE_ONCE(ri->map, NULL);
 
 	return XDP_REDIRECT;
@@ -3753,8 +3753,8 @@ BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex,
 	if (unlikely(flags))
 		return XDP_ABORTED;
 
-	ri->ifindex = ifindex;
 	ri->flags = flags;
+	ri->tgt_index = ifindex;
 	WRITE_ONCE(ri->map, map);
 
 	return XDP_REDIRECT;