Re: [PATCH net] netfilter: xt_hashlimit: do not allow empty names

On Fri, Feb 02, 2018 at 12:49:38PM +0100, Pablo Neira Ayuso wrote:
[...]

Or place this in the core, something like:

bool net_valid_name(const char *name, size_t len)
{
        ...
}

then use it from dev_valid_name()

bool dev_valid_name(const char *name)
{
        return net_valid_name(name, IFNAMSIZ);
}

Just to clarify, I think I prefer this approach, probably other
subsystem can benefit from this generic approach too.

BTW, I wonder if we should use strnlen() instead of strlen() in
dev_valid_name(), I guess this not useful for device name since they
are guaranteed to be nul-terminated, but netfilter this would be good
given userspace can send us a non nul-terminated string. But in
general, I think it doesn't harm to use strnlen() in dev_valid_name().

Am I missing anything in all these tricky string handling? Thanks!