[Intel-wired-lan] [PATCH bpf-next 2/6] xdp: introduce xdp_do_redirect_ext() function
Björn Töpel
bjorn.topel at gmail.com
Fri Sep 4 13:53:27 UTC 2020
From: Björn Töpel <bjorn.topel at intel.com>
Introduce the xdp_do_redirect_ext() which returns additional
information to the caller. For now, it is the type of map that the
packet was redirected to.
This enables the driver to have more fine-grained control, e.g. is the
redirect fails due to full AF_XDP Rx queue (error code ENOBUFS and map
is XSKMAP), a zero-copy enabled driver should yield to userland as
soon as possible.
Signed-off-by: Björn Töpel <bjorn.topel at intel.com>
---
include/linux/filter.h | 2 ++
net/core/filter.c | 16 ++++++++++++++--
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 995625950cc1..0060c2c8abc3 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -942,6 +942,8 @@ static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
*/
int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
struct xdp_buff *xdp, struct bpf_prog *prog);
+int xdp_do_redirect_ext(struct net_device *dev, struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog, enum bpf_map_type *map_type);
int xdp_do_redirect(struct net_device *dev,
struct xdp_buff *xdp,
struct bpf_prog *prog);
diff --git a/net/core/filter.c b/net/core/filter.c
index 47eef9a0be6a..ce6098210a23 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3596,8 +3596,8 @@ void bpf_clear_redirect_map(struct bpf_map *map)
}
}
-int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
- struct bpf_prog *xdp_prog)
+int xdp_do_redirect_ext(struct net_device *dev, struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog, enum bpf_map_type *map_type)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
struct bpf_map *map = READ_ONCE(ri->map);
@@ -3609,6 +3609,8 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
ri->tgt_value = NULL;
WRITE_ONCE(ri->map, NULL);
+ *map_type = BPF_MAP_TYPE_UNSPEC;
+
if (unlikely(!map)) {
fwd = dev_get_by_index_rcu(dev_net(dev), index);
if (unlikely(!fwd)) {
@@ -3618,6 +3620,7 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
err = dev_xdp_enqueue(fwd, xdp, dev);
} else {
+ *map_type = map->map_type;
err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
}
@@ -3630,6 +3633,15 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
return err;
}
+EXPORT_SYMBOL_GPL(xdp_do_redirect_ext);
+
+int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog)
+{
+ enum bpf_map_type dummy;
+
+ return xdp_do_redirect_ext(dev, xdp, xdp_prog, &dummy);
+}
EXPORT_SYMBOL_GPL(xdp_do_redirect);
static int xdp_do_generic_redirect_map(struct net_device *dev,
--
2.25.1
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