Duplicate set

As the same message can be received several times, due to different nodes forwarding it, one needs some system to avoid duplicate processing of data. This is what the duplicate set is used for as described in section 3.4.2. The duplicate set can be queried through this function, implemented in src/duplicate_set.c:

int
olsr_check_dup_table_proc(union olsr_ip_addr *, 
                          olsr_u16_t);

This function also updates the duplicate set if no match is found, so that the message queried for is registered as processed. Note that no standard olsrd functionality calls this function directly. The olsr_forward_message function, presented in section 6.10, takes care of both querying the duplicate table and queuing the message for forwarding if necessary.