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.fastab...@gmail.com>
Acked-by: Daniel Borkmann <dan...@iogearbox.net>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 2 +-
include/linux/filter.h | 4 ++-
include/trace/events/xdp.h | 31 ++++++++++++++++++++++++-
net/core/filter.c | 13 +++++++---
4 files changed, 43 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 3db0473..38f7ff9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -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
diff --git a/include/linux/filter.h b/include/linux/filter.h
index ccb73d8..997b9c9 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -669,7 +669,9 @@ 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);
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 1b61357..7b1eb7b 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -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 @@
__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>
diff --git a/net/core/filter.c b/net/core/filter.c
index 1fbe079..441abbb 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -54,6 +54,7 @@
#include <net/dst.h>
#include <net/sock_reuseport.h>
#include <net/busy_poll.h>
+#include <linux/bpf_trace.h>
/**
* sk_filter_trim_cap - run a packet through a socket filter
@@ -2308,18 +2309,22 @@ 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);
