/*
* tree navigation primitives (must obtain lock before using these)
*/
/*
* sysctl_locate -- Finds the node matching the given mib under the
* given tree (via rv). If no tree is given, we fall back to the
* native tree. The current process (via l) is used for access
* control on the tree (some nodes may be traversable only by root) and
* on return, nip will show how many numbers in the mib were consumed.
*/