merge local_wifi (#1516)

* attempt at betterer wifi

* add preliminary sync mechanism
* fix gaps in wifi implementation

* move local-MP comm to its own module instead of cramping Platform.cpp

* remove some stupid cruft

* as you wish, Sorer

(starting work on shared-memory system)

* shared-memory IPC that actually works (albeit Windows-only for now)

* shut up logging from NULL writes on ARM7 (ffs Nintendo learn to code)

* get this somewhat good

* leave client sync mode when host deauths. makes download play actually work.

* start implementing MP-comm error handling

* * add MP-reply error counters
* feeble attempt at fixing slowdown/desync/etc problems

* somewhat better exchange/sync method

* * when entering power-saving mode, be sure to finish transferring the current frame first
* fix misc bug due to old cruft leftover

makes for a more stable connection

* remove a bunch of cruft

* set wifi time interval to 34 cycles instead of 33. games seem sensitive to the general timing of wifi vs the rest of the system, and this seems to make things run better, atleast until I rewrite this to use a proper scheduler.

* more graceful handling of disconnects

* deal with FIFO overflow more gracefully

* BAHAHAHAHAHAHAHAHHHH

THE SNEAKY BASTARDS

so, when the DS receives a beacon with the right BSSID

that beacon's timestamp is copied to USCOUNTER

* attempt at making the connection process smoother for weird games

* * begin adding POWCNT2, only applies to wifi for now
* begin work on wifi scheduler

* implement the shitty timers

* add the RF wakeup thing

* begin work on receiving frames. for now it can just receive melonAP beacons, but hey, it's a start.

* add enough TX functionality that online wifi is a possibility again.

* there are problems with this scheduler thing. committing it anyway

* kind of a rollback... we're gonna work out a compromise on this, I guess

* don't transmit shit if RXCNT.bit15 isn't set

* move RX-finish to its own function. more accurate filtering. implement RXFILTER.

* remove some cruft

* fix some of the shittiness when trying to connect more than two players

* fix some more shittiness

* fix more wifi shittiness (mainly don't try to receive shit while sending a frame)

* run wifi every 8µs. improves performance.

* fix IRQ14/IRQ15

* make this work under Linux

* Make it work on macOS, for now using a custom sem_timedwait
implementation.

If anyone knows anything about mach ports and have an idea for how to
make this work using mach IPC, please do let me know.

* 25ms seems like a good timeout

* begin work on proper multiplayer UI shito.

for now, determine a global instance ID, and derivate the system MAC from it. remove 'randomize MAC' option.

* finish removing RandomizeMAC

* lay groundwork for instance-unique config

* work some on the UI... make it not labelled Fart

* more UI work: make it explicit that some things are instance-unique

* separate firmware files for multiplayer instances

* make instances save to different save files, too

* more UI work, make things somewhat less shitty

* lay base for the multiplayer settings dialog

* actually hook up most of that dialog

* actually implement the fun audio settings

* ensure all the wifi shit is properly savestated and reset. properly update timings for the wifi region when wifi is disabled.

* add more fun labels

* * ignore WEP frames if WEP is off
* implement RX_LEN_CROP

* fake enough of WEP processing to make Inazuma Eleven work

* * do not copy more ROM banner data than actually needed
* avoid trying to read out of bounds if the banner offset is bad

* Fix oversight with the preferences action causing the build to fail on macOS

Co-authored-by: Nadia Holmquist Pedersen <nadia@nhp.sh>

1 files changed, 488 insertions, 0 deletions

diff --git a/src/frontend/qt_sdl/sem_timedwait.cpp b/src/frontend/qt_sdl/sem_timedwait.cpp
new file mode 100644
index 0000000..38b3c16
--- /dev/null
+++ b/src/frontend/qt_sdl/sem_timedwait.cpp
@@ -0,0 +1,488 @@
+/*
+ *                       s e m _ t i m e d w a i t
+ *
+ *  Function:
+ *     Implements a version of sem_timedwait().
+ *
+ *  Description:
+ *     Not all systems implement sem_timedwait(), which is a version of
+ *     sem_wait() with a timeout. Mac OS X is one example, at least up to
+ *     and including version 10.6 (Leopard). If such a function is needed,
+ *     this code provides a reasonable implementation, which I think is
+ *     compatible with the standard version, although possibly less
+ *     efficient. It works by creating a thread that interrupts a normal
+ *     sem_wait() call after the specified timeout.
+ *
+ *  Call:
+ *
+ *     The Linux man pages say:
+ *
+ *     #include <semaphore.h>
+ *
+ *     int sem_timedwait(sem_t *sem, const struct timespec *abs_timeout);
+ *
+ *     sem_timedwait() is the same as sem_wait(), except that abs_timeout 
+ *     specifies a limit on the amount of time that the call should block if 
+ *     the decrement cannot be immediately performed. The abs_timeout argument
+ *     points to a structure that specifies an absolute timeout in seconds and
+ *     nanoseconds since the Epoch (00:00:00, 1 January 1970). This structure 
+ *     is defined as follows:
+ *
+ *     struct timespec {
+ *        time_t tv_sec;      Seconds
+ *        long   tv_nsec;     Nanoseconds [0 .. 999999999]
+ *     };
+ *
+ *     If the timeout has already expired by the time of the call, and the 
+ *     semaphore could not be locked immediately, then sem_timedwait() fails 
+ *     with a timeout error (errno set to ETIMEDOUT).
+ *     If the operation can be performed immediately, then sem_timedwait() 
+ *     never fails with a timeout error, regardless of the value of abs_timeout.
+ *     Furthermore, the validity of abs_timeout is not checked in this case.
+ *
+ *  Limitations:
+ *
+ *     The mechanism used involves sending a SIGUSR2 signal to the thread
+ *     calling sem_timedwait(). The handler for this signal is set to a null
+ *     routine which does nothing, and with any flags for the signal 
+ *     (eg SA_RESTART) cleared. Note that this effective disabling of the
+ *     SIGUSR2 signal is a side-effect of using this routine, and means it
+ *     may not be a completely transparent plug-in replacement for a
+ *     'normal' sig_timedwait() call. Since OS X does not declare the
+ *     sem_timedwait() call in its standard include files, the relevant 
+ *     declaration (shown above in the man pages extract) will probably have
+ *     to be added to any code that uses this.
+ *
+ *  Compiling:
+ *     This compiles and runs cleanly on OS X (10.6) with gcc with the
+ *     -Wall -ansi -pedantic flags. On Linux, using -ansi causes a sweep of
+ *     compiler complaints about the timespec structure, but it compiles
+ *     and works fine with just -Wall -pedantic. (Since Linux provides
+ *     sem_timedwait() anyway, this really isn't needed on Linux.) However,
+ *     since Linux provides sem_timedwait anyway, the sem_timedwait()
+ *     code in this file is only compiled on OS X, and is a null on other
+ *     systems.
+ *
+ *  Testing:
+ *     This file contains a test program that exercises the sem_timedwait
+ *     code. It is compiled if the pre-processor variable TEST is defined.
+ *     For more details, see the comments for the test routine at the end
+ *     of the file.
+ *
+ *  Author: Keith Shortridge, AAO.
+ *
+ *  History:
+ *      8th Sep 2009. Original version. KS.
+ *     24th Sep 2009. Added test that the calling thread still exists before
+ *                    trying to set the timed-out flag. KS.
+ *      2nd Oct 2009. No longer restores the original SIGUSR2 signal handler.
+ *                    See comments in the body of the code for more details.
+ *                    Prototypes for now discontinued internal routines removed.
+ *     12th Aug 2010. Added the cleanup handler, so that this code no longer
+ *                    leaks resources if the calling thread is cancelled. KS.
+ *     21st Sep 2011. Added copyright notice below. Modified header comments
+ *                    to describe the use of SIGUSR2 more accurately in the 
+ *                    light of the 2/10/09 change above. Now undefs DEBUG
+ *                    before defining it, to avoid any possible clash. KS.
+ *     14th Feb 2012. Tidied out a number of TABs that had got into the
+ *                    code. KS.
+ *      6th May 2013. Copyright notice modified to one based on the MIT licence,
+ *                    which is more permissive than the previous notice. KS.
+ *
+ *  Copyright (c) Australian Astronomical Observatory (AAO), (2013).
+ *  Permission is hereby granted, free of charge, to any person obtaining a 
+ *  copy of this software and associated documentation files (the "Software"), 
+ *  to deal in the Software without restriction, including without limitation 
+ *  the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+ *  and/or sell copies of the Software, and to permit persons to whom the 
+ *  Software is furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in 
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+ *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ *  IN THE SOFTWARE.
+ */
+
+#ifdef __APPLE__
+
+#include <semaphore.h>
+#include <time.h>
+#include <sys/time.h>
+#include <pthread.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <setjmp.h>
+
+#include "sem_timedwait.h"
+
+/*  Some useful definitions - TRUE, FALSE, and DEBUG */
+
+#undef TRUE
+#define TRUE 1
+#undef FALSE
+#define FALSE 0
+#undef DEBUG
+#define DEBUG printf
+
+/*  A structure of type timeoutDetails is passed to the thread used to 
+ *  implement the timeout.
+ */
+
+typedef struct {
+   struct timespec delay;            /* Specifies the delay, relative to now */
+   pthread_t callingThread;          /* The thread doing the sem_wait call */
+   volatile short *timedOutShort;    /* Address of a flag set to indicate that
+                                      * the timeout was triggered. */
+} timeoutDetails;
+
+/*  A structure of type cleanupDetails is passed to the thread cleanup 
+ *  routine which is called at the end of the routine or if the thread calling
+ *  it is cancelled.
+ */
+ 
+typedef struct {
+   pthread_t *threadIdAddr;          /* Address of the variable that holds 
+                                      * the Id of the timeout thread. */
+   struct sigaction *sigHandlerAddr; /* Address of the old signal action
+                                      * handler. */
+   volatile short *timedOutShort;    /* Address of a flag set to indicate that
+                                      * the timeout was triggered. */
+} cleanupDetails;
+
+/*  Forward declarations of internal routines */
+
+static void* timeoutThreadMain (void* passedPtr);
+static int triggerSignal (int Signal, pthread_t Thread);
+static void ignoreSignal (int Signal);
+static void timeoutThreadCleanup (void* passedPtr);
+
+/* -------------------------------------------------------------------------- */
+/*
+ *                      s e m _ t i m e d w a i t
+ *
+ *  This is the main code for the sem_timedwait() implementation.
+ */
+
+int sem_timedwait (
+   sem_t *sem,
+   const struct timespec *abs_timeout)
+{
+   int result = 0;                   /* Code returned by this routine 0 or -1 */
+   
+   /*  "Under no circumstances shall the function fail if the semaphore
+    *  can be locked immediately". So we try to get it quickly to see if we
+    *  can avoid all the timeout overheads.
+    */
+   
+   if (sem_trywait(sem) == 0) {
+      
+      /*  Yes, got it immediately. */
+      
+      result = 0;
+      
+   } else {
+      
+      /*  No, we've got to do it with a sem_wait() call and a thread to run
+       *  the timeout. First, work out the time from now to the specified
+       *  timeout, which we will pass to the timeout thread in a way that can
+       *  be used to pass to nanosleep(). So we need this in seconds and
+       *  nanoseconds. Along the way, we check for an invalid passed time,
+       *  and for one that's already expired.
+       */
+      
+      if ((abs_timeout->tv_nsec < 0) || (abs_timeout->tv_nsec > 1000000000)) {
+         
+         /* Passed time is invalid */
+         
+         result = -1;
+         errno = EINVAL;
+         
+      } else {
+         
+         struct timeval currentTime;                              /* Time now */
+         long secsToWait,nsecsToWait;            /* Seconds and nsec to delay */
+         gettimeofday (&currentTime,NULL);
+         secsToWait = abs_timeout->tv_sec - currentTime.tv_sec;
+         nsecsToWait = (abs_timeout->tv_nsec - (currentTime.tv_usec * 1000));
+         while (nsecsToWait < 0) {
+            nsecsToWait += 1000000000;
+            secsToWait--;
+         }
+         if ((secsToWait < 0) || ((secsToWait == 0) && (nsecsToWait < 0))) {
+            
+            /*  Time has passed. Report an immediate timeout. */
+            
+            result = -1;
+            errno = ETIMEDOUT;
+            
+         } else {
+            
+            /*  We're going to have to do a sem_wait() with a timeout thread.
+             *  The thread will wait the specified time, then will issue a
+             *  SIGUSR2 signal that will interrupt the sem_wait() call. 
+             *  We pass the thread the id of the current thread, the delay,
+             *  and the address of a flag to set on a timeout, so we can 
+             *  distinguish an interrupt caused by the timeout thread from
+             *  one caused by some other signal.
+             */
+         
+            volatile short timedOut;                /* Flag to set on timeout */
+            timeoutDetails details;     /* All the stuff the thread must know */
+            struct sigaction oldSignalAction;       /* Current signal setting */
+            pthread_t timeoutThread;                  /* Id of timeout thread */
+            cleanupDetails cleaningDetails; /* What the cleanup routine needs */
+            int oldCancelState;                /* Previous cancellation state */
+            int ignoreCancelState;               /* Used in call, but ignored */
+            int createStatus;              /* Status of pthread_create() call */
+            
+            /*  If the current thread is cancelled (and CML does do this)
+             *  we don't want to leave our timer thread running - if we've
+             *  started the thread we want to make sure we join it in order
+             *  to release its resources. So we set a cleanup handler to
+             *  do this. We pass it the address of the structure that will
+             *  hold all it needs to know. While we set all this up,
+             *  we prevent ourselves being cancelled, so all this data is
+             *  coherent.
+             */
+            
+            pthread_setcancelstate (PTHREAD_CANCEL_DISABLE,&oldCancelState);
+            timeoutThread = (pthread_t) 0;
+            cleaningDetails.timedOutShort = &timedOut;
+            cleaningDetails.threadIdAddr = &timeoutThread;
+            cleaningDetails.sigHandlerAddr = &oldSignalAction;
+            pthread_cleanup_push (timeoutThreadCleanup,&cleaningDetails);
+            
+            /*  Set up the details for the thread. Clear the timeout flag,
+             *  record the current SIGUSR2 action settings so we can restore
+             *  them later.
+             */
+            
+            details.delay.tv_sec = secsToWait;
+            details.delay.tv_nsec = nsecsToWait;
+            details.callingThread = pthread_self();
+            details.timedOutShort = &timedOut;
+            timedOut = FALSE;
+            sigaction (SIGUSR2,NULL,&oldSignalAction);
+            
+            /*  Start up the timeout thread. Once we've done that, we can
+             *  restore the previous cancellation state.
+             */
+            
+            createStatus = pthread_create(&timeoutThread,NULL,
+                                         timeoutThreadMain, (void*)&details);
+            pthread_setcancelstate (oldCancelState,&ignoreCancelState);
+            
+            if (createStatus < 0) {
+               
+               /* Failed to create thread. errno will already be set properly */
+               
+               result = -1;
+               
+            } else {
+               
+               /*  Thread created OK. This is where we wait for the semaphore.
+                */
+               
+               if (sem_wait(sem) == 0) {
+                  
+                  /*  Got the semaphore OK. We return zero, and all's well. */
+                  
+                  result = 0;
+                  
+               } else {
+                  
+                  /*  If we got a -1 error from sem_wait(), it may be because
+                   *  it was interrupted by a timeout, or failed for some
+                   *  other reason. We check for the expected timeout 
+                   *  condition, which is an 'interrupted' status and the
+                   *  timeout flag set by the timeout thread. We report that as
+                   *  a timeout error. Anything else is some other error and
+                   *  errno is already set properly.
+                   */
+                  
+                  result = -1;
+                  if (errno == EINTR) {
+                     if (timedOut) errno = ETIMEDOUT;
+                  }
+               }
+               
+            }
+            
+            /*  The cleanup routine - timeoutThreadCleanup() - packages up
+             *  any tidying up that is needed, including joining with the
+             *  timer thread. This will be called if the current thread is
+             *  cancelled, but we need it to happen anyway, so we set the
+             *  execute flag true here as we remove it from the list of
+             *  cleanup routines to be called. So normally, this line amounts
+             *  to calling timeoutThreadCleanup().
+             */
+             
+            pthread_cleanup_pop (TRUE);
+         }
+      }
+   }
+   return (result);
+}
+
+/* -------------------------------------------------------------------------- */
+/*
+ *                  t i m e o u t  T h r e a d  C l e a n u p
+ *
+ *  This internal routine tidies up at the end of a sem_timedwait() call.
+ *  It is set as a cleanup routine for the current thread (not the timer
+ *  thread) so it is executed even if the thread is cancelled. This is
+ *  important, as we need to tidy up the timeout thread. If we took the
+ *  semaphore (in other words, if we didn't timeout) then the timer thread
+ *  will still be running, sitting in its nanosleep() call, and we need
+ *  to cancel it. If the timer thread did signal a timeout then it will
+ *  now be closing down. In either case, we need to join it (using a call
+ *  to pthread_join()) or its resources will never be released.
+ *  The single argument is a pointer to a cleanupDetails structure that has
+ *  all the routine needs to know.
+ */
+   
+static void timeoutThreadCleanup (void* passedPtr)
+{
+   /*  Get what we need from the structure we've been passed. */
+   
+   cleanupDetails *detailsPtr = (cleanupDetails*) passedPtr;
+   short timedOut = *(detailsPtr->timedOutShort);
+   pthread_t timeoutThread = *(detailsPtr->threadIdAddr);
+   
+   /*  If we created the thread, stop it - doesn't matter if it's no longer
+    *  running, pthread_cancel can handle that. We make sure we wait for it 
+    *  to complete, because it is this pthread_join() call that releases any 
+    *  memory the thread may have allocated. Note that cancelling a thread is 
+    *  generally not a good idea, because of the difficulty of cleaning up 
+    *  after it, but this is a very simple thread that does nothing but call 
+    *  nanosleep(), and that we can cancel quite happily.
+    */
+      
+   if (!timedOut) pthread_cancel(timeoutThread);
+   pthread_join(timeoutThread,NULL);
+   
+   /*  The code originally restored the old action handler, which generally 
+    *  was the default handler that caused the task to exit. Just occasionally,
+    *  there seem to be cases where the signal is still queued and ready to 
+    *  trigger even though the thread that presumably sent it off just before
+    *  it was cancelled has finished. I had thought that once we'd joined
+    *  that thread, we could be sure of not seeing the signal, but that seems 
+    *  not to be the case, and so restoring a handler that will allow the task
+    *  to crash is not a good idea, and so the line below has been commented
+    *  out.
+    *
+    *  sigaction (SIGUSR2,detailsPtr->sigHandlerAddr,NULL);
+    */
+}
+
+/* -------------------------------------------------------------------------- */
+/*
+ *                  t i m e o u t  T h r e a d  M a i n
+ *
+ *  This internal routine is the main code for the timeout thread.
+ *  The single argument is a pointer to a timeoutDetails structure that has
+ *  all the thread needs to know - thread to signal, delay time, and the
+ *  address of a flag to set if it triggers a timeout.
+ */
+   
+static void* timeoutThreadMain (void* passedPtr)
+{
+   void* Return = (void*) 0;
+   
+   /*  We grab all the data held in the calling thread right now. In some
+    *  cases, we find that the calling thread has vanished and released
+    *  its memory, including the details structure, by the time the timeout
+    *  expires, and then we get an access violation when we try to set the
+    *  'timed out' flag.
+    */
+   
+   timeoutDetails details = *((timeoutDetails*) passedPtr);
+   struct timespec requestedDelay = details.delay;
+   
+   /*  We do a nanosleep() for the specified delay, and then trigger a
+    *  timeout. Note that we allow for the case where the nanosleep() is
+    *  interrupted, and restart it for the remaining time. If the 
+    *  thread that is doing the sem_wait() call gets the semaphore, it
+    *  will cancel this thread, which is fine as we aren't doing anything
+    *  other than a sleep and a signal.
+    */
+   
+   for (;;) {
+      struct timespec remainingDelay;
+      if (nanosleep (&requestedDelay,&remainingDelay) == 0) {
+         break;
+      } else if (errno == EINTR) {
+         requestedDelay = remainingDelay;
+      } else {
+         Return = (void*) errno;
+         break;
+      }
+   }
+   
+   /*  We've completed the delay without being cancelled, so we now trigger
+    *  the timeout by sending a signal to the calling thread. And that's it,
+    *  although we set the timeout flag first to indicate that it was us
+    *  that interrupted the sem_wait() call. One precaution: before we
+    *  try to set the timed-out flag, make sure the calling thread still
+    *  exists - this may not be the case if things are closing down a bit
+    *  messily. We check this quickly using a zero test signal.
+    */
+   
+   if (pthread_kill(details.callingThread,0) == 0) {
+      *(details.timedOutShort) = TRUE;
+      if (triggerSignal (SIGUSR2,details.callingThread) < 0) {
+         Return = (void*) errno;
+      }
+   }
+   
+   return Return;
+}
+   
+/* -------------------------------------------------------------------------- */
+/*
+ *                    t r i g g e r  S i g n a l
+ *
+ *  This is a general purpose routine that sends a specified signal to
+ *  a specified thread, setting up a signal handler that does nothing,
+ *  and then giving the signal. The only effect will be to interrupt any
+ *  operation that is currently blocking - in this case, we expect this to
+ *  be a sem_wait() call.
+ */
+   
+static int triggerSignal (int Signal, pthread_t Thread)
+{
+   int Result = 0;
+   struct sigaction SignalDetails;
+   SignalDetails.sa_handler = ignoreSignal;
+   SignalDetails.sa_flags = 0;
+   (void) sigemptyset(&SignalDetails.sa_mask);
+   if ((Result = sigaction(Signal,&SignalDetails,NULL)) == 0) {
+      Result = pthread_kill(Thread,Signal);
+   }
+   return Result;
+}
+   
+/* -------------------------------------------------------------------------- */
+/*
+ *                     i g n o r e  S i g n a l
+ *
+ *  And this is the signal handler that does nothing. (It clears its argument,
+ *  but this has no effect and prevents a compiler warning about an unused
+ *  argument.)
+ */
+    
+static void ignoreSignal (int Signal) {
+   Signal = 0;
+} 
+
+#endif