2018-04-24 18:55 GMT+02:00 Willem de Bruijn <willemdebruijn.ker...@gmail.com>:
> On Mon, Apr 23, 2018 at 9:56 AM, Björn Töpel <bjorn.to...@gmail.com> wrote:
>> From: Magnus Karlsson <magnus.karls...@intel.com>
>>
>> Here, the bind syscall is added. Binding an AF_XDP socket, means
>> associating the socket to an umem, a netdev and a queue index. This
>> can be done in two ways.
>>
>> The first way, creating a "socket from scratch". Create the umem using
>> the XDP_UMEM_REG setsockopt and an associated fill queue with
>> XDP_UMEM_FILL_QUEUE. Create the Rx queue using the XDP_RX_QUEUE
>> setsockopt. Call bind passing ifindex and queue index ("channel" in
>> ethtool speak).
>>
>> The second way to bind a socket, is simply skipping the
>> umem/netdev/queue index, and passing another already setup AF_XDP
>> socket. The new socket will then have the same umem/netdev/queue index
>> as the parent so it will share the same umem. You must also set the
>> flags field in the socket address to XDP_SHARED_UMEM.
>>
>> Signed-off-by: Magnus Karlsson <magnus.karls...@intel.com>
>> ---
>
>> +static struct socket *xsk_lookup_xsk_from_fd(int fd, int *err)
>> +{
>> + struct socket *sock;
>> +
>> + *err = -ENOTSOCK;
>> + sock = sockfd_lookup(fd, err);
>> + if (!sock)
>> + return NULL;
>> +
>> + if (sock->sk->sk_family != PF_XDP) {
>> + *err = -ENOPROTOOPT;
>> + sockfd_put(sock);
>> + return NULL;
>> + }
>> +
>> + *err = 0;
>> + return sock;
>> +}
>
> In this and similar cases, can use ERR_PTR to avoid the extra argument.
Noted. Thanks!
