Re: [PATCHv2 bpf-next 2/4] xdp: extend xdp_redirect_map with broadcast support

---
 include/linux/bpf.h            |  16 +++++
 include/net/xdp.h              |   1 +
 include/uapi/linux/bpf.h       |  17 ++++-
 kernel/bpf/devmap.c            | 119 +++++++++++++++++++++++++++++++++
 net/core/filter.c              |  74 ++++++++++++++++++--
 net/core/xdp.c                 |  29 ++++++++
 tools/include/uapi/linux/bpf.h |  17 ++++-
 7 files changed, 262 insertions(+), 11 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c931bc97019d..bb07ccd170f2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h

@@ -1458,6 +1458,9 @@ int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
 		    struct net_device *dev_rx);
 int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
 		    struct net_device *dev_rx);
+bool dst_dev_is_ingress(struct bpf_dtab_netdev *obj, int ifindex);
+int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx,
+			  struct bpf_map *map, bool exclude_ingress);
 int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
 			     struct bpf_prog *xdp_prog);
 bool dev_map_can_have_prog(struct bpf_map *map);

@@ -1630,6 +1633,19 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
 	return 0;
 }
 
+static inline
+bool dst_dev_is_ingress(struct bpf_dtab_netdev *obj, int ifindex)
+{
+	return false;
+}
+
+static inline
+int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx,
+			  struct bpf_map *map, bool exclude_ingress)
+{
+	return 0;
+}
+
 struct sk_buff;
 
 static inline int dev_map_generic_redirect(struct bpf_dtab_netdev *dst,

diff --git a/include/net/xdp.h b/include/net/xdp.h
index a5bc214a49d9..5533f0ab2afc 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h

@@ -170,6 +170,7 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
 struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
 					 struct net_device *dev);
 int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp);
+struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf);
 
 static inline
 void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2d3036e292a9..5982ceb217dc 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h

@@ -2508,8 +2508,12 @@ union bpf_attr {
  * 		The lower two bits of *flags* are used as the return code if
  * 		the map lookup fails. This is so that the return value can be
  * 		one of the XDP program return codes up to **XDP_TX**, as chosen
- * 		by the caller. Any higher bits in the *flags* argument must be
- * 		unset.
+ * 		by the caller. The higher bits of *flags* can be set to
+ * 		BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below.
+ *
+ * 		With BPF_F_BROADCAST the packet will be broadcasted to all the
+ * 		interfaces in the map. with BPF_F_EXCLUDE_INGRESS the ingress
+ * 		interface will be excluded when do broadcasting.
  *
  * 		See also **bpf_redirect**\ (), which only supports redirecting
  * 		to an ifindex, but doesn't require a map to do so.

@@ -5004,6 +5008,15 @@ enum {
 	BPF_F_BPRM_SECUREEXEC	= (1ULL << 0),
 };
 
+/* Flags for bpf_redirect_map helper */
+enum {
+	BPF_F_BROADCAST		= (1ULL << 3),
+	BPF_F_EXCLUDE_INGRESS	= (1ULL << 4),
+};
+
+#define BPF_F_ACTION_MASK (XDP_ABORTED | XDP_DROP | XDP_PASS | XDP_TX)
+#define BPF_F_REDIR_MASK (BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS)
+
 #define __bpf_md_ptr(type, name)	\
 union {					\
 	type name;			\

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f80cf5036d39..ad616a043d2a 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c

@@ -519,6 +519,125 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
 	return __xdp_enqueue(dev, xdp, dev_rx, dst->xdp_prog);
 }
 
+/* Use direct call in fast path instead of map->ops->map_get_next_key() */
+static int devmap_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	switch (map->map_type) {
+	case BPF_MAP_TYPE_DEVMAP:
+		return dev_map_get_next_key(map, key, next_key);
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+		return dev_map_hash_get_next_key(map, key, next_key);
+	default:
+		break;
+	}
+
+	return -ENOENT;
+}
+
+bool dst_dev_is_ingress(struct bpf_dtab_netdev *dst, int ifindex)
+{
+	return dst->dev->ifindex == ifindex;
+}
+
+static struct bpf_dtab_netdev *devmap_get_next_obj(struct xdp_buff *xdp,
+						   struct bpf_map *map,
+						   u32 *key, u32 *next_key,
+						   int ex_ifindex)
+{
+	struct bpf_dtab_netdev *obj;
+	struct net_device *dev;
+	u32 *tmp_key = key;