Re: [PATCH net-next 01/11] net: sock: introduce SOCK_XDP

[Jason Wang <jasowang@redhat.com>]

On 2018年09月07日 00:56, Michael S. Tsirkin wrote:
> On Thu, Sep 06, 2018 at 12:05:16PM +0800, Jason Wang wrote:
>> This patch introduces a new sock flag - SOCK_XDP. This will be used
>> for notifying the upper layer that XDP program is attached on the
>> lower socket, and requires for extra headroom.
>>
>> TUN will be the first user.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> In fact vhost is the 1st user, right? So this can be
> pushed out to become patch 10/11.

Better with an independent patch, since patch 10/11 can work without XDP.

Thanks

>
>> ---
>>   drivers/net/tun.c  | 19 +++++++++++++++++++
>>   include/net/sock.h |  1 +
>>   2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
>> index ebd07ad82431..2c548bd20393 100644
>> --- a/drivers/net/tun.c
>> +++ b/drivers/net/tun.c
>> @@ -869,6 +869,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
>>   		tun_napi_init(tun, tfile, napi);
>>   	}
>>   
>> +	if (rtnl_dereference(tun->xdp_prog))
>> +		sock_set_flag(&tfile->sk, SOCK_XDP);
>> +
>>   	tun_set_real_num_queues(tun);
>>   
>>   	/* device is allowed to go away first, so no need to hold extra
>> @@ -1241,13 +1244,29 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
>>   		       struct netlink_ext_ack *extack)
>>   {
>>   	struct tun_struct *tun = netdev_priv(dev);
>> +	struct tun_file *tfile;
>>   	struct bpf_prog *old_prog;
>> +	int i;
>>   
>>   	old_prog = rtnl_dereference(tun->xdp_prog);
>>   	rcu_assign_pointer(tun->xdp_prog, prog);
>>   	if (old_prog)
>>   		bpf_prog_put(old_prog);
>>   
>> +	for (i = 0; i < tun->numqueues; i++) {
>> +		tfile = rtnl_dereference(tun->tfiles[i]);
>> +		if (prog)
>> +			sock_set_flag(&tfile->sk, SOCK_XDP);
>> +		else
>> +			sock_reset_flag(&tfile->sk, SOCK_XDP);
>> +	}
>> +	list_for_each_entry(tfile, &tun->disabled, next) {
>> +		if (prog)
>> +			sock_set_flag(&tfile->sk, SOCK_XDP);
>> +		else
>> +			sock_reset_flag(&tfile->sk, SOCK_XDP);
>> +	}
>> +
>>   	return 0;
>>   }
>>   
>> diff --git a/include/net/sock.h b/include/net/sock.h
>> index 433f45fc2d68..38cae35f6e16 100644
>> --- a/include/net/sock.h
>> +++ b/include/net/sock.h
>> @@ -800,6 +800,7 @@ enum sock_flags {
>>   	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
>>   	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
>>   	SOCK_TXTIME,
>> +	SOCK_XDP, /* XDP is attached */
>>   };
>>   
>>   #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
>> -- 
>> 2.17.1