From 2facaad6000f2322eb40ca379aced31c957f0a41 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 24 Aug 2017 12:33:08 +0200 Subject: [PATCH] xdp: make generic xdp redirect use tracepoint trace_xdp_redirect If the xdp_do_generic_redirect() call fails, it trigger the trace_xdp_exception tracepoint. It seems better to use the same tracepoint trace_xdp_redirect, as the native xdp_do_redirect{,_map} does. Signed-off-by: Jesper Dangaard Brouer Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/filter.h | 3 ++- net/core/dev.c | 4 ++-- net/core/filter.c | 35 +++++++++++++++++++++++------------ 3 files changed, 27 insertions(+), 15 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 7015116331af..d29e58fde364 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -718,7 +718,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, * because we only track one map and force a flush when the map changes. * This does not appear to be a real limitation for existing software. */ -int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb); +int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, + struct bpf_prog *prog); int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, struct bpf_prog *prog); diff --git a/net/core/dev.c b/net/core/dev.c index 40b28e417072..270b54754821 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3953,7 +3953,8 @@ int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb) if (act != XDP_PASS) { switch (act) { case XDP_REDIRECT: - err = xdp_do_generic_redirect(skb->dev, skb); + err = xdp_do_generic_redirect(skb->dev, skb, + xdp_prog); if (err) goto out_redir; /* fallthru to submit skb */ @@ -3966,7 +3967,6 @@ int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb) } return XDP_PASS; out_redir: - trace_xdp_exception(skb->dev, xdp_prog, XDP_REDIRECT); kfree_skb(skb); return XDP_DROP; } diff --git a/net/core/filter.c b/net/core/filter.c index a5e5f31b41b9..a04680331033 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2553,26 +2553,37 @@ out: } EXPORT_SYMBOL_GPL(xdp_do_redirect); -int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb) +int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, + struct bpf_prog *xdp_prog) { struct redirect_info *ri = this_cpu_ptr(&redirect_info); - unsigned int len; u32 index = ri->ifindex; + struct net_device *fwd; + unsigned int len; + int err = 0; - dev = dev_get_by_index_rcu(dev_net(dev), index); + fwd = dev_get_by_index_rcu(dev_net(dev), index); ri->ifindex = 0; - if (unlikely(!dev)) { - return -EINVAL; + if (unlikely(!fwd)) { + err = -EINVAL; + goto out; } - if (unlikely(!(dev->flags & IFF_UP))) - return -ENETDOWN; - len = dev->mtu + dev->hard_header_len + VLAN_HLEN; - if (skb->len > len) - return -E2BIG; + if (unlikely(!(fwd->flags & IFF_UP))) { + err = -ENETDOWN; + goto out; + } - skb->dev = dev; - return 0; + len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN; + if (skb->len > len) { + err = -EMSGSIZE; + goto out; + } + + skb->dev = fwd; +out: + trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err); + return err; } EXPORT_SYMBOL_GPL(xdp_do_generic_redirect);