packet: add classic BPF fanout mode
Add fanout mode PACKET_FANOUT_CBPF that accepts a classic BPF program
to select a socket.
This avoids having to keep adding special case fanout modes. One
example use case is application layer load balancing. The QUIC
protocol, for instance, encodes a connection ID in UDP payload.
Also add socket option SOL_PACKET/PACKET_FANOUT_DATA that updates data
associated with the socket group. Fanout mode PACKET_FANOUT_CBPF is the
only user so far.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h
index d3d715f8c..a4bb16f 100644
--- a/include/uapi/linux/if_packet.h
+++ b/include/uapi/linux/if_packet.h
@@ -55,6 +55,7 @@
#define PACKET_TX_HAS_OFF 19
#define PACKET_QDISC_BYPASS 20
#define PACKET_ROLLOVER_STATS 21
+#define PACKET_FANOUT_DATA 22
#define PACKET_FANOUT_HASH 0
#define PACKET_FANOUT_LB 1
@@ -62,6 +63,7 @@
#define PACKET_FANOUT_ROLLOVER 3
#define PACKET_FANOUT_RND 4
#define PACKET_FANOUT_QM 5
+#define PACKET_FANOUT_CBPF 6
#define PACKET_FANOUT_FLAG_ROLLOVER 0x1000
#define PACKET_FANOUT_FLAG_DEFRAG 0x8000