constructing IPv6 in6_addr structure from ipv6

constructing IPv6 in6_addr structure from ipv6

[Steve French]

Is there a recommended way to construct a struct sockaddr_in6 in kernel
which is the format the connect function on a socket requires for ipv6
addresses?

Basically this boils down to how to best construct a struct in6_addr
starting with a IPv6 network address represented as a familiar dotted
address character string.   I would prefer to convert this in kernel via
something like inet_pton(AF_INET6,original_address_string,
converted_to_in6_add_form) but I could convert in userspace and pass the
16 byte array down to the kernel mangled as a string, via a mount
option.

Is it better to mangle the address and pass it down, or do something
similar to inet_pton?   This can't be the first time that someone has
wanted to deal with an ipv6 address coming from userspace ...