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Commit f2e52095 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

packet: add extended BPF fanout mode 



Add fanout mode PACKET_FANOUT_EBPF that accepts an en extended BPF
program to select a socket.

Update the internal eBPF program by passing to socket option
SOL_PACKET/PACKET_FANOUT_DATA a file descriptor returned by bpf().

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 47dceb8e

include/uapi/linux/if_packet.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ struct sockaddr_ll { 
#define PACKET_FANOUT_RND		4

#define PACKET_FANOUT_QM		5

#define PACKET_FANOUT_CBPF		6

#define PACKET_FANOUT_EBPF		7

#define PACKET_FANOUT_FLAG_ROLLOVER	0x1000

#define PACKET_FANOUT_FLAG_DEFRAG	0x8000

net/packet/af_packet.c

+31 −0
Original line number Diff line number Diff line
@@ -1472,6 +1472,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 
		idx = fanout_demux_rollover(f, skb, 0, false, num);

		break;

	case PACKET_FANOUT_CBPF:

	case PACKET_FANOUT_EBPF:

		idx = fanout_demux_bpf(f, skb, num);

		break;

	}
@@ -1529,6 +1530,7 @@ static void fanout_init_data(struct packet_fanout *f) 
		atomic_set(&f->rr_cur, 0);

		break;

	case PACKET_FANOUT_CBPF:

	case PACKET_FANOUT_EBPF:

		RCU_INIT_POINTER(f->bpf_prog, NULL);

		break;

	}
@@ -1571,12 +1573,39 @@ static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data, 
	return 0;

}



static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,

				unsigned int len)

{

	struct bpf_prog *new;

	u32 fd;



	if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))

		return -EPERM;

	if (len != sizeof(fd))

		return -EINVAL;

	if (copy_from_user(&fd, data, len))

		return -EFAULT;



	new = bpf_prog_get(fd);

	if (IS_ERR(new))

		return PTR_ERR(new);

	if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) {

		bpf_prog_put(new);

		return -EINVAL;

	}



	__fanout_set_data_bpf(po->fanout, new);

	return 0;

}



static int fanout_set_data(struct packet_sock *po, char __user *data,

			   unsigned int len)

{

	switch (po->fanout->type) {

	case PACKET_FANOUT_CBPF:

		return fanout_set_data_cbpf(po, data, len);

	case PACKET_FANOUT_EBPF:

		return fanout_set_data_ebpf(po, data, len);

	default:

		return -EINVAL;

	};
@@ -1586,6 +1615,7 @@ static void fanout_release_data(struct packet_fanout *f) 
{

	switch (f->type) {

	case PACKET_FANOUT_CBPF:

	case PACKET_FANOUT_EBPF:

		__fanout_set_data_bpf(f, NULL);

	};

}
@@ -1608,6 +1638,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 
	case PACKET_FANOUT_RND:

	case PACKET_FANOUT_QM:

	case PACKET_FANOUT_CBPF:

	case PACKET_FANOUT_EBPF:

		break;

	default:

		return -EINVAL;