Re: [PATCH net-next] rtnetlink: mpls: ip_valid_fib_dump_req() requires CONFIG_INET

[David Ahern]

On 10/9/18 10:10 AM, Arnd Bergmann wrote:
> The newly added call to ip_valid_fib_dump_req() causes a link error
> in configurations that enable MPLS but not IPv4:
> 
> net/mpls/af_mpls.o: In function `mpls_dump_routes':
> af_mpls.c:(.text+0xed0): undefined reference to `ip_valid_fib_dump_req'
> 
> With the added IS_ENABLED() check we get the previous behavior
> back in that configuration, and skip the check.
> 
> Fixes: e8ba330ac0c5 ("rtnetlink: Update fib dumps for strict data checking")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  net/mpls/af_mpls.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
> index 7f891ffffc05..99ff6114d513 100644
> --- a/net/mpls/af_mpls.c
> +++ b/net/mpls/af_mpls.c
> @@ -2041,7 +2041,7 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
>  
>  	ASSERT_RTNL();
>  
> -	if (cb->strict_check) {
> +	if (IS_ENABLED(CONFIG_INET) && cb->strict_check) {
>  		int err = ip_valid_fib_dump_req(nlh, cb->extack);
>  
>  		if (err < 0)
> 

If INET is not defined then mpls will need its own valid_dump_req
function to ensure strict_check semantics are managed. I'll send a patch.