/**
* Send a MLD message (report or done).
*
* An IPv6 hop-by-hop options header with a router alert option
* is prepended.
*
* @param group the group to report or quit
* @param type ICMP6_TYPE_MLR (report) or ICMP6_TYPE_MLD (done)
*/
static void
mld6_send(struct mld_group *group, u8_t type)
{
struct mld_header * mld_hdr;
struct pbuf * p;
ip6_addr_t * src_addr;
/* Allocate a packet. Size is MLD header + IPv6 Hop-by-hop options header. */
p = pbuf_alloc(PBUF_IP, sizeof(struct mld_header) + sizeof(struct ip6_hbh_hdr), PBUF_RAM);
if ((p == NULL) || (p->len < (sizeof(struct mld_header) + sizeof(struct ip6_hbh_hdr)))) {
/* We couldn't allocate a suitable pbuf. drop it. */
if (p != NULL) {
pbuf_free(p);
}
MLD6_STATS_INC(mld6.memerr);
return;
}
/* Move to make room for Hop-by-hop options header. */
if (pbuf_header(p, -IP6_HBH_HLEN)) {
pbuf_free(p);
MLD6_STATS_INC(mld6.lenerr);
return;
}
/* Select our source address. */
if (!ip6_addr_isvalid(netif_ip6_addr_state(group->netif, 0))) {
/* This is a special case, when we are performing duplicate address detection.
* We must join the multicast group, but we don't have a valid address yet. */
src_addr = IP6_ADDR_ANY;
} else {
/* Use link-local address as source address. */
src_addr = netif_ip6_addr(group->netif, 0);
}
/* MLD message header pointer. */
mld_hdr = (struct mld_header *)p->payload;
/* Set fields. */
mld_hdr->type = type;
mld_hdr->code = 0;
mld_hdr->chksum = 0;
mld_hdr->max_resp_delay = 0;
mld_hdr->reserved = 0;
ip6_addr_set(&(mld_hdr->multicast_address), &(group->group_address));
#if CHECKSUM_GEN_ICMP6
mld_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len,
src_addr, &(group->group_address));
#endif /* CHECKSUM_GEN_ICMP6 */
/* Add hop-by-hop headers options: router alert with MLD value. */
ip6_options_add_hbh_ra(p, IP6_NEXTH_ICMP6, IP6_ROUTER_ALERT_VALUE_MLD);
/* Send the packet out. */
MLD6_STATS_INC(mld6.xmit);
ip6_output_if(p, (ip6_addr_isany(src_addr)) ? NULL : src_addr, &(group->group_address),
MLD6_HL, 0, IP6_NEXTH_HOPBYHOP, group->netif);
pbuf_free(p);
}
/**
* Leave a group on a network interface.
*
* @param srcaddr ipv6 address of the network interface which should
* leave the group. If IP6_ISANY, leave on all netifs
* @param groupaddr the ipv6 address of the group to leave
* @return ERR_OK if group was left on the netif(s), an err_t otherwise
*/
err_t
mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
{
err_t err = ERR_VAL; /* no matching interface */
struct mld_group *group;
struct netif *netif;
u8_t match;
u8_t i;
/* loop through netif's */
netif = netif_list;
while (netif != NULL) {
/* Should we leave this interface ? */
match = 0;
if (ip6_addr_isany(srcaddr)) {
match = 1;
}
else {
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
if (!ip6_addr_isinvalid(netif_ip6_addr_state(netif, i)) &&
ip6_addr_cmp(srcaddr, netif_ip6_addr(netif, i))) {
match = 1;
break;
}
}
}
if (match) {
/* find group */
group = mld6_lookfor_group(netif, groupaddr);
if (group != NULL) {
/* Leave if there is no other use of the group */
if (group->use <= 1) {
/* If we are the last reporter for this group */
if (group->last_reporter_flag) {
MLD6_STATS_INC(mld6.tx_leave);
mld6_send(group, ICMP6_TYPE_MLD);
}
/* Disable the group at the MAC level */
if (netif->mld_mac_filter != NULL) {
netif->mld_mac_filter(netif, groupaddr, MLD6_DEL_MAC_FILTER);
}
/* Free the group */
mld6_free_group(group);
} else {
/* Decrement group use */
group->use--;
}
/* Leave on this interface */
err = ERR_OK;
}
}
/* proceed to next network interface */
netif = netif->next;
}
return err;
}
/**
* timer for mld processing. Must be called based on smallest
* timer in group
* When a delaying member expires, a membership report is sent.
*/
void
mld6_tmr(void)
{
struct mld_group *group = mld_group_list;
unsigned long curr_ticks = sys_arch_get_os_ticks() / MLD_TIMER_OFFSET;
while (group != NULL) {
if (group->timer <= curr_ticks
&& group->timer != 0) {
group->timer = 0;
/* If the state is MLD6_GROUP_DELAYING_MEMBER then we send a report for this group */
if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
MLD6_STATS_INC(mld6.tx_report);
mld6_send(group, ICMP6_TYPE_MLR);
group->group_state = MLD6_GROUP_IDLE_MEMBER;
}
}
group = group->next;
}
struct mld_group* min_timeout_grp = lwip_get_min_timeout_mld_grp();
if (min_timeout_grp &&
(min_timeout_grp->timer) > curr_ticks) {
unsigned int new_timer_val =
((min_timeout_grp->timer) - curr_ticks) * MLD_TIMER_OFFSET;
sys_timeout(new_timer_val, mld6_timer, NULL);
}
}
/**
* Join a group on a network interface.
*
* @param srcaddr ipv6 address of the network interface which should
* join a new group. If IP6_ADDR_ANY, join on all netifs
* @param groupaddr the ipv6 address of the group to join
* @return ERR_OK if group was joined on the netif(s), an err_t otherwise
*/
err_t
mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
{
err_t err = ERR_VAL; /* no matching interface */
struct mld_group *group;
struct netif *netif;
u8_t match;
u8_t i;
/* loop through netif's */
netif = netif_list;
while (netif != NULL) {
/* Should we join this interface ? */
match = 0;
if (ip6_addr_isany(srcaddr)) {
match = 1;
}
else {
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
if (!ip6_addr_isinvalid(netif_ip6_addr_state(netif, i)) &&
ip6_addr_cmp(srcaddr, netif_ip6_addr(netif, i))) {
match = 1;
break;
}
}
}
if (match) {
/* find group or create a new one if not found */
group = mld6_lookfor_group(netif, groupaddr);
if (group == NULL) {
/* Joining a new group. Create a new group entry. */
group = mld6_new_group(netif, groupaddr);
if (group == NULL) {
return ERR_MEM;
}
/* Activate this address on the MAC layer. */
if (netif->mld_mac_filter != NULL) {
netif->mld_mac_filter(netif, groupaddr, MLD6_ADD_MAC_FILTER);
}
/* Report our membership. */
MLD6_STATS_INC(mld6.tx_report);
mld6_send(group, ICMP6_TYPE_MLR);
mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS);
}
/* Increment group use */
group->use++;
err = ERR_OK;
}
/* proceed to next network interface */
netif = netif->next;
}
return err;
}
/**
* Periodic timer for mld processing. Must be called every
* MLD6_TMR_INTERVAL milliseconds (100).
*
* When a delaying member expires, a membership report is sent.
*/
void
mld6_tmr(void)
{
struct mld_group *group = mld_group_list;
while (group != NULL) {
if (group->timer > 0) {
group->timer--;
if (group->timer == 0) {
/* If the state is MLD6_GROUP_DELAYING_MEMBER then we send a report for this group */
if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
MLD6_STATS_INC(mld6.tx_report);
mld6_send(group, ICMP6_TYPE_MLR);
group->group_state = MLD6_GROUP_IDLE_MEMBER;
}
}
}
group = group->next;
}
}
/**
* Process an input MLD message. Called by icmp6_input.
*
* @param p the mld packet, p->payload pointing to the icmpv6 header
* @param inp the netif on which this packet was received
*/
void
mld6_input(struct pbuf *p, struct netif *inp)
{
struct mld_header * mld_hdr;
struct mld_group* group;
MLD6_STATS_INC(mld6.recv);
/* Check that mld header fits in packet. */
if (p->len < sizeof(struct mld_header)) {
// TODO debug message
pbuf_free(p);
MLD6_STATS_INC(mld6.lenerr);
MLD6_STATS_INC(mld6.drop);
return;
}
mld_hdr = (struct mld_header *)p->payload;
switch (mld_hdr->type) {
case ICMP6_TYPE_MLQ: /* Multicast listener query. */
{
/* Is it a general query? */
if (ip6_addr_isallnodes_linklocal(ip6_current_dest_addr()) &&
ip6_addr_isany(&(mld_hdr->multicast_address))) {
MLD6_STATS_INC(mld6.rx_general);
/* Report all groups, except all nodes group, and if-local groups. */
group = mld_group_list;
while (group != NULL) {
if ((group->netif == inp) &&
(!(ip6_addr_ismulticast_iflocal(&(group->group_address)))) &&
(!(ip6_addr_isallnodes_linklocal(&(group->group_address))))) {
mld6_delayed_report(group, mld_hdr->max_resp_delay);
}
group = group->next;
}
}
else {
/* Have we joined this group?
* We use IP6 destination address to have a memory aligned copy.
* mld_hdr->multicast_address should be the same. */
MLD6_STATS_INC(mld6.rx_group);
group = mld6_lookfor_group(inp, ip6_current_dest_addr());
if (group != NULL) {
/* Schedule a report. */
mld6_delayed_report(group, mld_hdr->max_resp_delay);
}
}
break; /* ICMP6_TYPE_MLQ */
}
case ICMP6_TYPE_MLR: /* Multicast listener report. */
{
/* Have we joined this group?
* We use IP6 destination address to have a memory aligned copy.
* mld_hdr->multicast_address should be the same. */
MLD6_STATS_INC(mld6.rx_report);
group = mld6_lookfor_group(inp, ip6_current_dest_addr());
if (group != NULL) {
/* If we are waiting to report, cancel it. */
if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
group->timer = 0; /* stopped */
group->group_state = MLD6_GROUP_IDLE_MEMBER;
group->last_reporter_flag = 0;
}
}
break; /* ICMP6_TYPE_MLR */
}
case ICMP6_TYPE_MLD: /* Multicast listener done. */
{
/* Do nothing, router will query us. */
break; /* ICMP6_TYPE_MLD */
}
default:
MLD6_STATS_INC(mld6.proterr);
MLD6_STATS_INC(mld6.drop);
break;
}
pbuf_free(p);
}
