xdp: add trace event for xdp redirect

This adds a trace event for xdp redirect which may help when debugging
XDP programs that use redirect bpf commands.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Fastabend 2017-07-17 09:28:35 -07:00 committed by David S. Miller
parent 6453073987
commit 5acaee0a89
4 changed files with 43 additions and 7 deletions

View File

@ -2232,7 +2232,7 @@ static struct sk_buff *ixgbe_run_xdp(struct ixgbe_adapter *adapter,
result = ixgbe_xmit_xdp_ring(adapter, xdp);
break;
case XDP_REDIRECT:
err = xdp_do_redirect(adapter->netdev, xdp);
err = xdp_do_redirect(adapter->netdev, xdp, xdp_prog);
if (!err)
result = IXGBE_XDP_TX;
else

View File

@ -713,7 +713,9 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
const struct bpf_insn *patch, u32 len);
int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb);
int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp);
int xdp_do_redirect(struct net_device *dev,
struct xdp_buff *xdp,
struct bpf_prog *prog);
void bpf_warn_invalid_xdp_action(u32 act);
void bpf_warn_invalid_xdp_redirect(u32 ifindex);

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@ -12,7 +12,8 @@
FN(ABORTED) \
FN(DROP) \
FN(PASS) \
FN(TX)
FN(TX) \
FN(REDIRECT)
#define __XDP_ACT_TP_FN(x) \
TRACE_DEFINE_ENUM(XDP_##x);
@ -48,6 +49,34 @@ TRACE_EVENT(xdp_exception,
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB))
);
TRACE_EVENT(xdp_redirect,
TP_PROTO(const struct net_device *from,
const struct net_device *to,
const struct bpf_prog *xdp, u32 act),
TP_ARGS(from, to, xdp, act),
TP_STRUCT__entry(
__string(name_from, from->name)
__string(name_to, to->name)
__array(u8, prog_tag, 8)
__field(u32, act)
),
TP_fast_assign(
BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
__assign_str(name_from, from->name);
__assign_str(name_to, to->name);
__entry->act = act;
),
TP_printk("prog=%s from=%s to=%s action=%s",
__print_hex_str(__entry->prog_tag, 8),
__get_str(name_from), __get_str(name_to),
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB))
);
#endif /* _TRACE_XDP_H */
#include <trace/define_trace.h>

View File

@ -55,6 +55,7 @@
#include <net/sock_reuseport.h>
#include <net/busy_poll.h>
#include <net/tcp.h>
#include <linux/bpf_trace.h>
/**
* sk_filter_trim_cap - run a packet through a socket filter
@ -2422,18 +2423,22 @@ static int __bpf_tx_xdp(struct net_device *dev, struct xdp_buff *xdp)
return -EOPNOTSUPP;
}
int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp)
int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
struct net_device *fwd;
dev = dev_get_by_index_rcu(dev_net(dev), ri->ifindex);
fwd = dev_get_by_index_rcu(dev_net(dev), ri->ifindex);
ri->ifindex = 0;
if (unlikely(!dev)) {
if (unlikely(!fwd)) {
bpf_warn_invalid_xdp_redirect(ri->ifindex);
return -EINVAL;
}
return __bpf_tx_xdp(dev, xdp);
trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT);
return __bpf_tx_xdp(fwd, xdp);
}
EXPORT_SYMBOL_GPL(xdp_do_redirect);