xdp: add bpf_redirect helper function
This adds support for a bpf_redirect helper function to the XDP
infrastructure. For now this only supports redirecting to the egress
path of a port.
In order to support drivers handling a xdp_buff natively this patches
uses a new ndo operation ndo_xdp_xmit() that takes pushes a xdp_buff
to the specified device.
If the program specifies either (a) an unknown device or (b) a device
that does not support the operation a BPF warning is thrown and the
XDP_ABORTED error code is returned.
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>
diff --git a/include/linux/filter.h b/include/linux/filter.h
index bfef1e5..64cae7a 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -711,7 +711,11 @@ bool bpf_helper_changes_pkt_data(void *func);
struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
const struct bpf_insn *patch, u32 len);
+
+int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp);
+
void bpf_warn_invalid_xdp_action(u32 act);
+void bpf_warn_invalid_xdp_redirect(u32 ifindex);
#ifdef CONFIG_BPF_JIT
extern int bpf_jit_enable;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 779b235..77f5376 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -66,6 +66,7 @@ struct mpls_dev;
/* UDP Tunnel offloads */
struct udp_tunnel_info;
struct bpf_prog;
+struct xdp_buff;
void netdev_set_default_ethtool_ops(struct net_device *dev,
const struct ethtool_ops *ops);
@@ -1138,6 +1139,9 @@ struct xfrmdev_ops {
* int (*ndo_xdp)(struct net_device *dev, struct netdev_xdp *xdp);
* This function is used to set or query state related to XDP on the
* netdevice. See definition of enum xdp_netdev_command for details.
+ * int (*ndo_xdp_xmit)(struct net_device *dev, struct xdp_buff *xdp);
+ * This function is used to submit a XDP packet for transmit on a
+ * netdevice.
*
*/
struct net_device_ops {
@@ -1323,6 +1327,8 @@ struct net_device_ops {
int needed_headroom);
int (*ndo_xdp)(struct net_device *dev,
struct netdev_xdp *xdp);
+ int (*ndo_xdp_xmit)(struct net_device *dev,
+ struct xdp_buff *xdp);
};
/**
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e99e3e6..4dbb7a3 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -717,6 +717,7 @@ enum xdp_action {
XDP_DROP,
XDP_PASS,
XDP_TX,
+ XDP_REDIRECT,
};
/* user accessible metadata for XDP packet hook