It will be completely possible to implement subsystem with only include/freerdp/server/shadow.h and libfreerdp-shadow.
Details as following:
1. Exported surface structure as subsystem implementations deeply depend on it to send image update
2. Export capture APIs. They are actually indepent APIs to help compare and calculate image difference.
3. Introduce API to trigger client frame update. Conceal details in subsystem->updateEvent
4. Pass client to client callbacks. Subsystem implementation may need to know 'which client' send the interaction event as well as the authentication request.
Add this support in callback definition before anyone really use shadow framework APIs to implement a custom subsystem.
Also added callback for client capability exchange
5. Remove X11_ShadowSubsystem Mac_ShadowSubsystem Win_ShadowSubsystem from libfreerdp-shadow.
Discard FREERDP_API mark on ShadowSubsystemEntry functions and make them be compiled together with shadow.c in CMakeLists.txt.
This is required from PR #2751.
Now subsystem implementations and shadow.c could be regarded as an example for shadow framework.
This patch contains:
* checks for malloc return value + treat callers;
* modified malloc() + ZeroMemory() to calloc();
* misc fixes of micro errors seen during the code audit:
** some invalid checks in gcc.c, also there were some possible
integer overflow. This is interesting because at the end the data are parsed
and freed directly, so it's a vulnerability in some kind of dead code (at least
useless);
** fixed usage of GetComputerNameExA with just one call, when 2 were used
in misc places. According to MSDN GetComputerNameA() is supposed to return
an error when called with NULL;
** there were a bug in the command line parsing of shadow;
** in freerdp_dynamic_channel_collection_add() the size of array was multiplied
by 4 instead of 2 on resize
1)
Added missing checks for CreateEvent which also required the
following related changes:
- changed freerdp_context_new API to BOOL
- changed freerdp_peer_context_new API to BOOL
- changed pRdpClientNew callback to BOOL
- changed pContextNew callback to BOOL
- changed psPeerAccepted callback to BOOL
- changed psPeerContextNew callback to BOOL
2)
Fixed lots of missing alloc and error checks in the
changed code's neighbourhood.
3)
Check freerdp_client_codecs_prepare result to avoid segfaults
caused by using non-initialized codecs.
4)
Fixed deadlocks in x11 caused by missing xf_unlock_x11() calls
in some error handlers
5)
Some fixes in thread pool:
- DEFAULT_POOL assignment did not match TP_POOL definition
- don't free the pool pointer if it points to the static DEFAULT_POOL
- added error handling and cleanup in InitializeThreadpool
