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>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 8869d07..7b8e39a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1472,6 +1472,7 @@
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 @@
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 @@
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 @@
{
switch (f->type) {
case PACKET_FANOUT_CBPF:
+ case PACKET_FANOUT_EBPF:
__fanout_set_data_bpf(f, NULL);
};
}
@@ -1608,6 +1638,7 @@
case PACKET_FANOUT_RND:
case PACKET_FANOUT_QM:
case PACKET_FANOUT_CBPF:
+ case PACKET_FANOUT_EBPF:
break;
default:
return -EINVAL;