/*
* Allocate space for the kludge at interface initialization time.
* Formerly, we dynamically allocated the space in in6_savemkludge() with
* malloc(M_WAITOK). However, it was wrong since the function could be called
* under an interrupt context (software timer on address lifetime expiration).
* Also, we cannot just give up allocating the strucutre, since the group
* membership structure is very complex and we need to keep it anyway.
* Of course, this function MUST NOT be called under an interrupt context.
* Specifically, it is expected to be called only from in6_ifattach(), though
* it is a global function.
*/