From e4a8e817d3cb2a5108f8bb2e47e81eb25a2c5e30 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 23 Aug 2017 01:47:53 +0200 Subject: [PATCH] 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: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- net/core/filter.c | 72 +++++++++++++++++++++-------------------------- 1 file changed, 32 insertions(+), 40 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index fa2115695037..2a0d762a20d8 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -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) @@ -2520,16 +2495,14 @@ 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, - struct bpf_prog *xdp_prog) +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); struct bpf_map *map = ri->map; @@ -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); }