if(m->op == DHCP_REPLY) {
if(m->op == DHCP_REPLY && memcmp(m->xid, xid, sizeof(xid)) == 0) {
parse_msg(void){  struct dhcp_msg *m = (struct dhcp_msg *)uip_appdata;    if(m->op == DHCP_REPLY) {    memcpy(s.ipaddr, m->yiaddr, 4);    parse_options(&m->options[4], uip_datalen());  }}