void mldProcessListenerReport(NetInterface *interface, Ipv6PseudoHeader *pseudoHeader,
const ChunkedBuffer *buffer, size_t offset, uint8_t hopLimit)
{
uint_t i;
size_t length;
MldMessage *message;
Ipv6FilterEntry *entry;
//Retrieve the length of the MLD message
length = chunkedBufferGetLength(buffer) - offset;
//The message must be at least 24 octets long
if(length < sizeof(MldMessage))
return;
//Point to the beginning of the MLD message
message = chunkedBufferAt(buffer, offset);
//Sanity check
if(!message) return;
//Debug message
TRACE_INFO("MLD message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message contents for debugging purpose
mldDumpMessage(message);
//Make sure the source address of the message is a valid link-local address
if(!ipv6IsLinkLocalUnicastAddr(&pseudoHeader->srcAddr))
return;
//Check the Hop Limit field
if(hopLimit != MLD_HOP_LIMIT)
return;
//Acquire exclusive access to the IPv6 filter table
osMutexAcquire(interface->ipv6FilterMutex);
//Loop through filter table entries
for(i = 0; i < interface->ipv6FilterSize; i++)
{
//Point to the current entry
entry = &interface->ipv6Filter[i];
//Report messages are ignored for multicast addresses
//in the Non-Listener or Idle Listener state
if(entry->state == MLD_STATE_DELAYING_LISTENER)
{
//The Multicast Listener Report message matches the current entry?
if(ipv6CompAddr(&message->multicastAddr, &entry->addr))
{
//Clear flag
entry->flag = FALSE;
//Switch to the Idle Listener state
entry->state = MLD_STATE_IDLE_LISTENER;
}
}
}
//Release exclusive access to the IPv6 filter table
osMutexRelease(interface->ipv6FilterMutex);
}
void ndpProcessRouterAdv(NetInterface *interface, Ipv6PseudoHeader *pseudoHeader,
const ChunkedBuffer *buffer, size_t offset, uint8_t hopLimit)
{
size_t length;
NdpRouterAdvMessage *message;
//Retrieve the length of the message
length = chunkedBufferGetLength(buffer) - offset;
//Check the length of the Router Advertisement message
if(length < sizeof(NdpRouterAdvMessage))
return;
//Point to the beginning of the message
message = chunkedBufferAt(buffer, offset);
//Sanity check
if(!message) return;
//Debug message
TRACE_INFO("Router Advertisement message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message contents for debugging purpose
ndpDumpRouterAdvMessage(message);
//Routers must use their link-local address as the source for the
//Router Advertisement so that hosts can uniquely identify routers
if(!ipv6IsLinkLocalUnicastAddr(&pseudoHeader->srcAddr))
return;
//The IPv6 Hop Limit field must have a value of 255 to ensure
//that the packet has not been forwarded by a router
if(hopLimit != NDP_HOP_LIMIT)
return;
//ICMPv6 Code must be 0. An advertisement that passes the validity
//checks is called a valid advertisement
if(message->code)
return;
#if (SLAAC_SUPPORT == ENABLED)
//Stateless Address Autoconfiguration is currently used?
if(interface->slaacContext != NULL)
{
//Process the valid advertisement
slaacProcessRouterAdv(interface->slaacContext,
&pseudoHeader->srcAddr, message, length);
}
#endif
}
void mldProcessListenerQuery(NetInterface *interface, Ipv6PseudoHeader *pseudoHeader,
const ChunkedBuffer *buffer, size_t offset, uint8_t hopLimit)
{
uint_t i;
size_t length;
systime_t time;
systime_t maxRespDelay;
MldMessage *message;
Ipv6FilterEntry *entry;
//Retrieve the length of the MLD message
length = chunkedBufferGetLength(buffer) - offset;
//The message must be at least 24 octets long
if(length < sizeof(MldMessage))
return;
//Point to the beginning of the MLD message
message = chunkedBufferAt(buffer, offset);
//Sanity check
if(!message) return;
//Debug message
TRACE_INFO("MLD message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message contents for debugging purpose
mldDumpMessage(message);
//Make sure the source address of the message is a valid link-local address
if(!ipv6IsLinkLocalUnicastAddr(&pseudoHeader->srcAddr))
return;
//Check the Hop Limit field
if(hopLimit != MLD_HOP_LIMIT)
return;
//Get current time
time = osGetTickCount();
//The Max Resp Delay field specifies the maximum time allowed
//before sending a responding report
maxRespDelay = message->maxRespDelay * 10;
//Acquire exclusive access to the IPv6 filter table
osMutexAcquire(interface->ipv6FilterMutex);
//Loop through filter table entries
for(i = 0; i < interface->ipv6FilterSize; i++)
{
//Point to the current entry
entry = &interface->ipv6Filter[i];
//The link-scope all-nodes address (FF02::1) is handled as a special
//case. The host starts in Idle Listener state for that address on
//every interface and never transitions to another state
if(ipv6CompAddr(&entry->addr, &IPV6_LINK_LOCAL_ALL_NODES_ADDR))
continue;
//A General Query is used to learn which multicast addresses have listeners
//on an attached link. A Multicast-Address-Specific Query is used to learn
//if a particular multicast address has any listeners on an attached link
if(ipv6CompAddr(&message->multicastAddr, &IPV6_UNSPECIFIED_ADDR) ||
ipv6CompAddr(&message->multicastAddr, &entry->addr))
{
//Delaying Listener state?
if(entry->state == MLD_STATE_DELAYING_LISTENER)
{
//The timer has not yet expired?
if(timeCompare(time, entry->timer) < 0)
{
//If a timer for the address is already running, it is reset to
//the new random value only if the requested Max Response Delay
//is less than the remaining value of the running timer
if(maxRespDelay < (entry->timer - time))
{
//Restart delay timer
entry->timer = time + mldRand(maxRespDelay);
}
}
}
//Idle Listener state?
else if(entry->state == MLD_STATE_IDLE_LISTENER)
{
//Switch to the Delaying Listener state
entry->state = MLD_STATE_DELAYING_LISTENER;
//Delay the response by a random amount of time
entry->timer = time + mldRand(maxRespDelay);
}
}
}
//Release exclusive access to the IPv6 filter table
osMutexRelease(interface->ipv6FilterMutex);
}
