Re: [PATCH net-next v2 4/6] vxlan: check valid combinations of address scopes

[Sergei Shtylyov]

On 04/14/2017 07:44 PM, Matthias Schiffer wrote:

> * Multicast addresses are never valid as local address
> * Link-local IPv6 unicast addresses may only be used as remote when the
>   local address is link-local as well
> * Don't allow link-local IPv6 local/remote addresses without interface
>
> We also store in the flags field if link-local addresses are used for the
> follow-up patches that actually make VXLAN over link-local IPv6 work.
>
> Signed-off-by: Matthias Schiffer <mschiffer@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> v2: was "vxlan: don't allow link-local IPv6 local/remote addresses without
> interface" before. v2 does a lot more checks and adds the
> VXLAN_F_IPV6_LINKLOCAL flag.
>
>  drivers/net/vxlan.c | 35 +++++++++++++++++++++++++++++++++++
>  include/net/vxlan.h |  2 ++
>  2 files changed, 37 insertions(+)
>
> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> index 07f89b037681..95a71546e8f2 100644
> --- a/drivers/net/vxlan.c
> +++ b/drivers/net/vxlan.c
> @@ -2881,11 +2881,39 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
>  	if (conf->saddr.sa.sa_family != conf->remote_ip.sa.sa_family)
>  		return -EINVAL;
>
> +	if (vxlan_addr_multicast(&conf->saddr))
> +		return -EINVAL;
> +
>  	if (conf->saddr.sa.sa_family == AF_INET6) {
>  		if (!IS_ENABLED(CONFIG_IPV6))
>  			return -EPFNOSUPPORT;
>  		use_ipv6 = true;
>  		conf->flags |= VXLAN_F_IPV6;
> +
> +		if (!(conf->flags & VXLAN_F_COLLECT_METADATA)) {
> +			int local_type =
> +				ipv6_addr_type(&conf->saddr.sin6.sin6_addr);
> +			int remote_type =
> +				ipv6_addr_type(&conf->remote_ip.sin6.sin6_addr);
> +
> +			if (local_type & IPV6_ADDR_LINKLOCAL) {
> +				if (!(remote_type & IPV6_ADDR_LINKLOCAL) &&
> +				    (remote_type != IPV6_ADDR_ANY)) {
> +					pr_info("invalid combination of address scopes\n");

   Maybe pr_err()?

> +					return -EINVAL;
> +				}
> +
> +				conf->flags |= VXLAN_F_IPV6_LINKLOCAL;
> +			} else {
> +				if (remote_type ==
> +				    (IPV6_ADDR_UNICAST | IPV6_ADDR_LINKLOCAL)) {
> +					pr_info("invalid combination of address scopes\n");

   Here as well...

> +					return -EINVAL;
> +				}
> +
> +				conf->flags &= ~VXLAN_F_IPV6_LINKLOCAL;
> +			}
> +		}
>  	}
>
>  	if (conf->label && !use_ipv6) {
[...]

MBR, Sergei