Re: [PATCH net-next 3/5] sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams

[David Miller]

From: Xin Long <lucien....@gmail.com>
Date: Mon, 25 Jun 2018 10:14:35 +0800

>  struct sctp_paddrparams {
> @@ -773,6 +775,8 @@ struct sctp_paddrparams {
>       __u32                   spp_pathmtu;
>       __u32                   spp_sackdelay;
>       __u32                   spp_flags;
> +     __u32                   spp_ipv6_flowlabel;
> +     __u8                    spp_dscp;
>  } __attribute__((packed, aligned(4)));

I don't think you can change the size of this structure like this.

This check in sctp_setsockopt_peer_addr_params():

        if (optlen != sizeof(struct sctp_paddrparams))
                return -EINVAL;

is going to trigger in old kernels when executing programs
built against the new struct definition.