Subject: Re: [PATCH net-next v2 1/6] gtp: make GTP sockets in gtp_newlink optional

From: Andreas Schultz <[email-masked]>
Date: Thu, 2 Feb 2017 15:30:51 +0100 (CET)

----- On Feb 2, 2017, at 3:10 PM, pablo [email-masked] wrote:

> On Mon, Jan 30, 2017 at 05:37:08PM +0100, Andreas Schultz wrote:
>> Having both GTPv0-U and GTPv1-U is not always desirable.
>> Fallback from GTPv1-U to GTPv0-U was depreciated from 3GPP
>> Rel-8 onwards. Post Rel-8 implementation are discuraged
>> from listening on the v0 port (see 3GPP TS 29.281, Sect. 1).
>> 
>> A future change will completely decouple the sockets from the
>> network device. Till then, at least one of the sockets needs to
>> be specified (either v0 or v1), the other is optional.
>> 
>> Signed-off-by: Andreas Schultz <[email-masked]>
>> ---
>>  drivers/net/gtp.c | 142 +++++++++++++++++++++++++++++-------------------------
>>  1 file changed, 76 insertions(+), 66 deletions(-)
>> 
>> diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
>> index bda0c64..18944f4 100644
>> --- a/drivers/net/gtp.c
>> +++ b/drivers/net/gtp.c
>> @@ -259,28 +259,30 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp,
>> struct sk_buff *skb,
>>  	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
>>  }
>>  
>> -static void gtp_encap_disable(struct gtp_dev *gtp)
>> -{
>> -	if (gtp->sock0 && gtp->sock0->sk) {
>> -		udp_sk(gtp->sock0->sk)->encap_type = 0;
>> -		rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
>> -	}
>> -	if (gtp->sock1u && gtp->sock1u->sk) {
>> -		udp_sk(gtp->sock1u->sk)->encap_type = 0;
>> -		rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
>> -	}
>> -
>> -	gtp->sock0 = NULL;
>> -	gtp->sock1u = NULL;
>> -}
>> -
>>  static void gtp_encap_destroy(struct sock *sk)
>>  {
>>  	struct gtp_dev *gtp;
>>  
>>  	gtp = rcu_dereference_sk_user_data(sk);
>> -	if (gtp)
>> -		gtp_encap_disable(gtp);
>> +	if (gtp) {
>> +		udp_sk(sk)->encap_type = 0;
>> +		rcu_assign_sk_user_data(sk, NULL);
>> +	}
>> +}
>> +
>> +static void gtp_encap_disable_sock(struct socket *sock)
> 
> Nitpick: Please, use sk for consistency:
> 
>        static void gtp_encap_disable_sock(struct socket *sk)
> 

Throughout the net subsystem 'struct socket` is always using sock
for variable names and 'struct sock' is using sk. I have been
following that convention, but can change to sk if you really want.

Andreas