lookup_ctx
lookup_ctx(FN_ctx_t *, const FN_composite_name_t *, bool_t log, FN_status_t *);
ctx = lookup_ctx(init_ctx, name, TRUE, status);
*prefix_ctxp = lookup_ctx(init_ctx, prefix, TRUE, status);
nns_ctx = lookup_ctx(*prefix_ctxp, slash_cname, FALSE, status);
*ctxp = lookup_ctx(nns_ctx, suffix, FALSE, status);
lookup_ctx(*prefix_ctxp, suffix, FALSE, status);
nns_ctx = lookup_ctx(ctx, slash_cname, FALSE, status);