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

From: Stephen Hemminger <[email-masked]>
Date: Fri, 14 Apr 2017 10:36:04 -0700

On Fri, 14 Apr 2017 18:44:44 +0200
Matthias Schiffer <mschiffer-Nyw9WiXk/[email-masked]> wrote:

> 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");

It is always helpful to include device if possible in error message.
					netdev_notice(old->dev, " invalid combination of address scopes\n");
Also vxlan is good candidate for extended netlink error reporting.