Commit ID: 2f8508c7
1. Fix possible crash when probing on particular interface with duplicated service instances due to naming conflicts on network. Issue: MDNS server initially sends probing packets to resolve naming confilicts with already registered service instances. In case of a conflict, instance name is altered and probing restarts. Original instance however wasnnot removed from the structure and upon service removal only one entry was removed and a dangling service might have been kept in the structure to bring about a crash. Resolution: Keep only one instance of a service in the probing structure
2. Enable pcbs before starting service thread to avoid updating pcb's internal variables from concurent tasks. Possible race condition: user task runs mdns_init, which enables pcbs while mdns-task already created could execute enable/disable of the same pcbs if an appropriate system event received
3. Fix possible deadlock on mdns deinit calling mdns_free(). Mnds_free() initiates stop and delete timer tasks, which after locking the mutex could lead to a dead lock in case timer task executed before deleting the task, as it would wait indefinitelly for unlocking the mutex. This condition is fixed by calling _mdns_stop_timer without locking the mutex, because there's no need to protect any data when stopping and deleting the timer task
4. Fix race condition in updating packet data from user task when failed to allocate or queue a new service. Issue: mdns_service_add API allocates and queues an action to be processed in mdns task context; when allocation or queueing fails, allocated structure needs to be freed. Function _mdns_free_service did not only fee all the structures, but also updates packet data. Resolution: Moved removal of packet data outside of _mdns_free_service function
5. Fix possible crash when packet scheduled to transmit contained service which might have been already removed. Packets scheduled to transmit are pushed to action queue and removed from tx_queue_head structure, which is searched for all remaining services and while service is removed, then service questions/asnwers are also removed from this structure. This update fixes possible crash when packet is pushed to action queue, and when service is removed, its answers are removed from tx_queue_head, but not from action queue. This could lead to a crash when the packet is poped from action queue containing questions/answers to already removed (freed) service
6. Use binary semaphore instead of mutex when searching. Mdns_search_once_t::lock is used to synchronize tasks (taken by one task and given by the other) so it should not be a mutex. Convert to semaphore, and rename to indicate its purpose
7. Fix memory leak in pbuf if tcpipadapter failed to get netif
8. Fix malfuctional query_txt. When running a query for a single txt, result entries were not created and attached to result structure. This issue was introduced when fixing memory leak in txt structure, which worked correctly for PTR queries, but caused trouble for TXT query
9. Fix possible crash when mdns_free called while action queue not empty
10. Fix memory leak when query for service receives multiple ptr entries for one instance
11. Fix crash after init if no memory for task. Mdns init first starts timer task, then starts service task. If service task failed to be created, timer task needs to be stopped too
12. Fixed crash on free undefined ptr after skipped strdup. Shortcircuit evaluation may cause skip of _mdns_strdup_check of any further question field, which after clear_rx_packet freed undefined memory
13. Fix networking running udp_sendif from lwip thread
14. Check all mallocs for failure and add default hook to log error with free heap. Solves crash about _mdns_result_txt_create when stress test
15. Fixed static memory leak
16. Resolve memory leak when txt record received multiple times
17. Skip sending search when finished, not properly locked timer task
18. Sending search packets also in probing and announcing state. Mdns queries did not work properly when send imeadiately after set_hostname, which cuased reinit of pcb and therefore restarted probing, so search packets were blocked until probing finished
