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Commit e4a8e817 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

bpf: misc xdp redirect cleanups 



Few cleanups including: bpf_redirect_map() is really XDP only due to
the return code. Move it to a more appropriate location where we do
the XDP redirect handling and change it's name into bpf_xdp_redirect_map()
to make it consistent to the bpf_xdp_redirect() helper.

xdp_do_redirect_map() helper can be static since only used out of filter.c
file. Drop the goto in xdp_do_generic_redirect() and only return errors
directly. In xdp_do_flush_map() only clear ri->map_to_flush which is the
arg we're using in that function, ri->map is cleared earlier along with
ri->ifindex.

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cd36c3a2

net/core/filter.c

+32 −40
Original line number Diff line number Diff line
@@ -1835,29 +1835,6 @@ static const struct bpf_func_proto bpf_redirect_proto = { 
	.arg2_type      = ARG_ANYTHING,

};



BPF_CALL_3(bpf_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags)

{

	struct redirect_info *ri = this_cpu_ptr(&redirect_info);



	if (unlikely(flags))

		return XDP_ABORTED;



	ri->ifindex = ifindex;

	ri->flags = flags;

	ri->map = map;



	return XDP_REDIRECT;

}



static const struct bpf_func_proto bpf_redirect_map_proto = {

	.func           = bpf_redirect_map,

	.gpl_only       = false,

	.ret_type       = RET_INTEGER,

	.arg1_type      = ARG_CONST_MAP_PTR,

	.arg2_type      = ARG_ANYTHING,

	.arg3_type      = ARG_ANYTHING,

};



BPF_CALL_3(bpf_sk_redirect_map, struct bpf_map *, map, u32, key, u64, flags)

{

	struct redirect_info *ri = this_cpu_ptr(&redirect_info);
@@ -2506,13 +2483,11 @@ static int __bpf_tx_xdp(struct net_device *dev, 
	err = dev->netdev_ops->ndo_xdp_xmit(dev, xdp);

	if (err)

		return err;



	if (map)

		__dev_map_insert_ctx(map, index);

	else

		dev->netdev_ops->ndo_xdp_flush(dev);



	return err;

	return 0;

}



void xdp_do_flush_map(void)
@@ -2520,15 +2495,13 @@ void xdp_do_flush_map(void) 
	struct redirect_info *ri = this_cpu_ptr(&redirect_info);

	struct bpf_map *map = ri->map_to_flush;



	ri->map = NULL;

	ri->map_to_flush = NULL;



	if (map)

		__dev_map_flush(map);

}

EXPORT_SYMBOL_GPL(xdp_do_flush_map);



int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,

static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,

			       struct bpf_prog *xdp_prog)

{

	struct redirect_info *ri = this_cpu_ptr(&redirect_info);
@@ -2545,14 +2518,12 @@ int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, 
		err = -EINVAL;

		goto out;

	}



	if (ri->map_to_flush && (ri->map_to_flush != map))

	if (ri->map_to_flush && ri->map_to_flush != map)

		xdp_do_flush_map();



	err = __bpf_tx_xdp(fwd, map, xdp, index);

	if (likely(!err))

		ri->map_to_flush = map;



out:

	trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err);

	return err;
@@ -2594,20 +2565,17 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb) 
	ri->ifindex = 0;

	if (unlikely(!dev)) {

		bpf_warn_invalid_xdp_redirect(index);

		goto err;

		return -EINVAL;

	}



	if (unlikely(!(dev->flags & IFF_UP)))

		goto err;



		return -ENETDOWN;

	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;

	if (skb->len > len)

		goto err;

		return -E2BIG;



	skb->dev = dev;

	return 0;

err:

	return -EINVAL;

}

EXPORT_SYMBOL_GPL(xdp_do_generic_redirect);
@@ -2620,6 +2588,7 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags) 


	ri->ifindex = ifindex;

	ri->flags = flags;



	return XDP_REDIRECT;

}
@@ -2631,6 +2600,29 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = { 
	.arg2_type      = ARG_ANYTHING,

};



BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags)

{

	struct redirect_info *ri = this_cpu_ptr(&redirect_info);



	if (unlikely(flags))

		return XDP_ABORTED;



	ri->ifindex = ifindex;

	ri->flags = flags;

	ri->map = map;



	return XDP_REDIRECT;

}



static const struct bpf_func_proto bpf_xdp_redirect_map_proto = {

	.func           = bpf_xdp_redirect_map,

	.gpl_only       = false,

	.ret_type       = RET_INTEGER,

	.arg1_type      = ARG_CONST_MAP_PTR,

	.arg2_type      = ARG_ANYTHING,

	.arg3_type      = ARG_ANYTHING,

};



bool bpf_helper_changes_pkt_data(void *func)

{

	if (func == bpf_skb_vlan_push ||
@@ -3233,7 +3225,7 @@ xdp_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_redirect:

		return &bpf_xdp_redirect_proto;

	case BPF_FUNC_redirect_map:

		return &bpf_redirect_map_proto;

		return &bpf_xdp_redirect_map_proto;

	default:

		return bpf_base_func_proto(func_id);

	}