-#ifdef DHCPV6_OPT_PREFIX_CLASS
- uint8_t *xdata;
- uint16_t xtype, xlen;
- struct dhcpv6_ia_addr *p = (struct dhcpv6_ia_addr*)&sdata[-4];
- dhcpv6_for_each_option(&p[1], sdata + slen, xtype, xlen, xdata) {
- if (xtype != DHCPV6_OPT_PREFIX_CLASS || xlen != 2)
- continue;
-
- if (classes_cnt >= classes_max)
- continue;
-
- classes[classes_cnt++] = (uint16_t)xdata[0] << 8 | (uint16_t)xdata[1];
- }
-#endif