rpl_parent_t *rpl_find_preferred_parent(void)
{
rpl_parent_t *best = NULL;
rpl_dodag_t *my_dodag = rpl_get_my_dodag();
if (my_dodag == NULL) {
DEBUG("Not part of a dodag\n");
return NULL;
}
for (uint8_t i = 0; i < RPL_MAX_PARENTS; i++) {
if (parents[i].used) {
if ((parents[i].rank == INFINITE_RANK) || (parents[i].lifetime <= 1)) {
DEBUG("Infinite rank, bad parent\n");
continue;
}
else if (best == NULL) {
DEBUG("possible parent\n");
best = &parents[i];
}
else {
best = my_dodag->of->which_parent(best, &parents[i]);
}
}
}
if (best == NULL) {
return NULL;
}
if (my_dodag->my_preferred_parent == NULL) {
my_dodag->my_preferred_parent = best;
}
if (!rpl_equal_id(&my_dodag->my_preferred_parent->addr, &best->addr)) {
if (my_dodag->mop != NO_DOWNWARD_ROUTES) {
/* send DAO with ZERO_LIFETIME to old parent */
send_DAO(&my_dodag->my_preferred_parent->addr, 0, false, 0);
}
my_dodag->my_preferred_parent = best;
if (my_dodag->mop != NO_DOWNWARD_ROUTES) {
delay_dao();
}
reset_trickletimer();
}
return best;
}
void dao_delay_over(void)
{
while (1) {
thread_sleep();
if ((ack_received == false) && (dao_counter < DAO_SEND_RETRIES)) {
dao_counter++;
send_DAO(NULL, 0, true, 0);
dao_time = timex_set(DEFAULT_WAIT_FOR_DAO_ACK, 0);
vtimer_remove(&dao_timer);
vtimer_set_wakeup(&dao_timer, dao_time, dao_delay_over_pid);
}
else if (ack_received == false) {
long_delay_dao();
}
}
}
void send_DAO(ipv6_addr_t *destination, uint8_t lifetime, bool default_lifetime, uint8_t start_index)
{
if (i_am_root) {
return;
}
mutex_lock(&rpl_send_mutex);
rpl_dodag_t *my_dodag;
my_dodag = rpl_get_my_dodag();
if (destination == NULL) {
destination = &my_dodag->my_preferred_parent->addr;
}
if (default_lifetime) {
lifetime = my_dodag->default_lifetime;
}
icmp_send_buf = get_rpl_send_icmpv6_buf(ipv6_ext_hdr_len);
icmp_send_buf->type = ICMPV6_TYPE_RPL_CONTROL;
icmp_send_buf->code = ICMP_CODE_DAO;
icmp_send_buf->checksum = ~icmpv6_csum(IPV6_PROTO_NUM_ICMPV6);
if (my_dodag == NULL) {
mutex_unlock(&rpl_send_mutex);
return;
}
rpl_send_dao_buf = get_rpl_send_dao_buf();
memset(rpl_send_dao_buf, 0, sizeof(*rpl_send_dao_buf));
rpl_send_dao_buf->rpl_instanceid = my_dodag->instance->id;
rpl_send_dao_buf->k_d_flags = 0x00;
rpl_send_dao_buf->dao_sequence = my_dodag->dao_seq;
uint16_t opt_len = 0;
rpl_send_opt_target_buf = get_rpl_send_opt_target_buf(DAO_BASE_LEN);
/* add all targets from routing table as targets */
uint8_t entries = 0;
uint8_t continue_index = 0;
for (uint8_t i = start_index; i < RPL_MAX_ROUTING_ENTRIES; i++) {
if (routing_table[i].used) {
rpl_send_opt_target_buf->type = RPL_OPT_TARGET;
rpl_send_opt_target_buf->length = RPL_OPT_TARGET_LEN;
rpl_send_opt_target_buf->flags = 0x00;
rpl_send_opt_target_buf->prefix_length = RPL_DODAG_ID_LEN;
memcpy(&rpl_send_opt_target_buf->target, &routing_table[i].address, sizeof(ipv6_addr_t));
opt_len += RPL_OPT_TARGET_LEN + 2;
rpl_send_opt_transit_buf = get_rpl_send_opt_transit_buf(DAO_BASE_LEN + opt_len);
rpl_send_opt_transit_buf->type = RPL_OPT_TRANSIT;
rpl_send_opt_transit_buf->length = RPL_OPT_TRANSIT_LEN;
rpl_send_opt_transit_buf->e_flags = 0x00;
rpl_send_opt_transit_buf->path_control = 0x00; /* not used */
rpl_send_opt_transit_buf->path_sequence = 0x00; /* not used */
rpl_send_opt_transit_buf->path_lifetime = lifetime;
opt_len += RPL_OPT_TRANSIT_LEN + 2;
rpl_send_opt_target_buf = get_rpl_send_opt_target_buf(DAO_BASE_LEN + opt_len);
entries++;
}
/* Split DAO, so packages don't get too big.
* The value 5 is based on experience. */
if (entries >= 5) {
continue_index = i + 1;
break;
}
}
/* add own address */
rpl_send_opt_target_buf->type = RPL_OPT_TARGET;
rpl_send_opt_target_buf->length = RPL_OPT_TARGET_LEN;
rpl_send_opt_target_buf->flags = 0x00;
rpl_send_opt_target_buf->prefix_length = RPL_DODAG_ID_LEN;
memcpy(&rpl_send_opt_target_buf->target, &my_address, sizeof(ipv6_addr_t));
opt_len += RPL_OPT_TARGET_LEN + 2;
rpl_send_opt_transit_buf = get_rpl_send_opt_transit_buf(DAO_BASE_LEN + opt_len);
rpl_send_opt_transit_buf->type = RPL_OPT_TRANSIT;
rpl_send_opt_transit_buf->length = RPL_OPT_TRANSIT_LEN;
rpl_send_opt_transit_buf->e_flags = 0x00;
rpl_send_opt_transit_buf->path_control = 0x00;
rpl_send_opt_transit_buf->path_sequence = 0x00;
rpl_send_opt_transit_buf->path_lifetime = lifetime;
opt_len += RPL_OPT_TRANSIT_LEN + 2;
uint16_t plen = ICMPV6_HDR_LEN + DAO_BASE_LEN + opt_len;
rpl_send(destination, (uint8_t *)icmp_send_buf, plen, IPV6_PROTO_NUM_ICMPV6, NULL);
mutex_unlock(&rpl_send_mutex);
if (continue_index > 1) {
send_DAO(destination, lifetime, default_lifetime, continue_index);
}
}
