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.
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.
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
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
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.
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
Previously, this compiler flag was not being applied
regardless of CONFIG_SPIRAM_CACHE_WORKAROUND setting.
Explanation: add_compile_options() only applies to
source files added after the function is run, or in
subdirectories added after the function is run. In
this case, no new source files were being added after
this function was run.
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.
Files where stack protector is initialized should not be compiled with
stack protector enabled. This was done for Make but missing for CMake.
Fixes https://github.com/espressif/esp-idf/issues/2990.
