Re: [PATCH net-next 02/24] sctp: use SCTP_FUTURE_ASSOC for SCTP_PEER_ADDR_PARAMS sockopt

From: Neil Horman <nhorman@tuxdriver.com>
To: Xin Long <lucien.xin@gmail.com>
Cc: network dev <netdev@vger.kernel.org>,
	linux-sctp@vger.kernel.org,
	Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
	davem@davemloft.net
Subject: Re: [PATCH net-next 02/24] sctp: use SCTP_FUTURE_ASSOC for SCTP_PEER_ADDR_PARAMS sockopt
Date: Tue, 29 Jan 2019 16:25:08 -0500	[thread overview]
Message-ID: <20190129212508.GB2592@neilslaptop.think-freely.org> (raw)
In-Reply-To: <bf66a45aa6763646c07e1b8be102466f07fc1648.1548659198.git.lucien.xin@gmail.com>

On Mon, Jan 28, 2019 at 03:08:24PM +0800, Xin Long wrote:
> Check with SCTP_FUTURE_ASSOC instead in
> sctp_/setgetsockopt_peer_addr_params, it's compatible with 0.
> 
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
>  net/sctp/socket.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index a52d132..4c43b95 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -2750,12 +2750,13 @@ static int sctp_setsockopt_peer_addr_params(struct sock *sk,
>  			return -EINVAL;
>  	}
>  
> -	/* Get association, if assoc_id != 0 and the socket is a one
> -	 * to many style socket, and an association was not found, then
> -	 * the id was invalid.
> +	/* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
> +	 * socket is a one to many style socket, and an association
> +	 * was not found, then the id was invalid.
>  	 */
>  	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
> -	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP))
> +	if (!asoc && params.spp_assoc_id != SCTP_FUTURE_ASSOC &&
Sorry to follow up, but I misspoke in my previous email, I should have said, why
do we only allow future associations as the only special case association id
here?  Since the function is meant to set a specific association id, it seems to
me that you would want to:

a) allow setting of a specific id
b) allow setting of all association ids on the socket
(SCTP_CURRENT_ASSOC)
c) allow recording of a set of params to apply to all current and future
associations (FUTURE/ALL).

(a) is already handled clearly, but (b) and (c) require more work on this
function than just checking association id on entry.

I think this comment may apply to all the socket option functions

> +	    sctp_style(sk, UDP))
>  		return -EINVAL;
>  
>  	/* Heartbeat demand can only be sent on a transport or
> @@ -5676,12 +5677,13 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
>  		}
>  	}
>  
> -	/* Get association, if assoc_id != 0 and the socket is a one
> -	 * to many style socket, and an association was not found, then
> -	 * the id was invalid.
> +	/* Get association, if assoc_id != SCTP_FUTURE_ASSOC and the
> +	 * socket is a one to many style socket, and an association
> +	 * was not found, then the id was invalid.
>  	 */
>  	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
> -	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP)) {
> +	if (!asoc && params.spp_assoc_id != SCTP_FUTURE_ASSOC &&
> +	    sctp_style(sk, UDP)) {
>  		pr_debug("%s: failed no association\n", __func__);
>  		return -EINVAL;
>  	}
> -- 
> 2.1.0
> 
> 