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: Willem de Bruijn <willemb@google.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Willem de Bruijn 2015-08-14 22:31:35 -04:00 committed by David S. Miller
parent 47dceb8ecd
commit f2e520956a
2 changed files with 32 additions and 0 deletions

View file

@ -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

View file

@ -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;