Re: [PATCH] geneve: fix max_mtu setting

[严海双]

> On Jun 26, 2016, at 8:35 PM, zhuyj <zyjzyj2000@xxxxxxxxx> wrote:
> 
> +       if (geneve->remote.sa.sa_family == AF_INET)
> +               max_mtu -= sizeof(struct iphdr);
> +       else
> +               max_mtu -= sizeof(struct ipv6hdr);
> 
> Sorry, if sa_family is not AF_NET, it is AF_INET6?
> 
> There is a lot of macros in include/linux/socket.h.
> 
> Zhu Yanjun
> 

There are only two enumerations AF_INET and AF_INET6 have been assigned in geneve_newlink:

        if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6])
                return -EINVAL;

        if (data[IFLA_GENEVE_REMOTE]) {
                remote.sa.sa_family = AF_INET;
                remote.sin.sin_addr.s_addr =
                        nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);
        }

        if (data[IFLA_GENEVE_REMOTE6]) {
                if (!IS_ENABLED(CONFIG_IPV6))
                        return -EPFNOSUPPORT;

                remote.sa.sa_family = AF_INET6;
                remote.sin6.sin6_addr =
                        nla_get_in6_addr(data[IFLA_GENEVE_REMOTE6]);

                if (ipv6_addr_type(&remote.sin6.sin6_addr) &
                    IPV6_ADDR_LINKLOCAL) {
                        netdev_dbg(dev, "link-local remote is unsupported\n");
                        return -EINVAL;
                }
        }

So I think the else case is for AF_INET6 only.