rem: static inline int hash_func(udomain_t* _d, char* _s, int _l)
add: static inline int hash_func(udomain_t* _d, unsigned char* _s, int _l)
context: static inline int hash_func(udomain_t* _d, char* _s, int _l){	int res = 0, i;		for(i = 0; i < _l; i++) {		res += _s[i];	}		return res % _d->size;}