entry_guard_obeys_restriction(const entry_guard_t *guard,
                              const entry_guard_restriction_t *rst)
{
  tor_assert(guard);
   if (! rst)
     return 1; // No restriction?  No problem.
 
  // Only one kind of restriction exists right now: excluding an exit
  // ID and all of its family.
  const node_t *node = node_get_by_id((const char*)rst->exclude_id);
  if (node && guard_in_node_family(guard, node))
    return 0;

   return tor_memneq(guard->identity, rst->exclude_id, DIGEST_LEN);
 }

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