Merge pull request #429 from pmj/ioshareddataqueue-workaround-dylib

Mac PrjFSLib: Use IOSharedDataQueue workaround library if available
microsoft · Oct 28, 2018 · 920fe27 · 920fe27
2 parents b471dd4 + c7e221b
commit 920fe27
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Showing 4 changed files with 117 additions and 5 deletions.
diff --git a/ProjFS.Mac/PrjFSLib/PrjFSLib.cpp b/ProjFS.Mac/PrjFSLib/PrjFSLib.cpp
@@ -215,7 +215,7 @@ PrjFS_Result PrjFS_StartVirtualizationInstance(
 
         while (1)
         {
-            IODataQueueEntry* entry = IODataQueuePeek(dataQueue.queueMemory);
+            IODataQueueEntry* entry = DataQueue_Peek(dataQueue.queueMemory);
             if (nullptr == entry)
             {
                 // No more items in queue
@@ -226,13 +226,13 @@ PrjFS_Result PrjFS_StartVirtualizationInstance(
             if (messageSize < sizeof(Message))
             {
                 cerr << "Bad message size: got " << messageSize << " bytes, expected minimum of " << sizeof(Message) << ", skipping. Kernel/user version mismatch?\n";
-                IODataQueueDequeue(dataQueue.queueMemory, nullptr, nullptr);
+                DataQueue_Dequeue(dataQueue.queueMemory, nullptr, nullptr);
                 continue;
             }
 
             void* messageMemory = malloc(messageSize);
             uint32_t dequeuedSize = messageSize;
-            IOReturn result = IODataQueueDequeue(dataQueue.queueMemory, messageMemory, &dequeuedSize);
+            IOReturn result = DataQueue_Dequeue(dataQueue.queueMemory, messageMemory, &dequeuedSize);
             if (kIOReturnSuccess != result || dequeuedSize != messageSize)
             {
                 cerr << "Unexpected result dequeueing message - result 0x" << hex << result << " dequeued " << dequeuedSize << "/" << messageSize << " bytes\n";

diff --git a/ProjFS.Mac/PrjFSLib/PrjFSUser.cpp b/ProjFS.Mac/PrjFSLib/PrjFSUser.cpp
@@ -3,6 +3,20 @@
 #include <IOKit/IOKitLib.h>
 #include <iostream>
 #include <mach/mach_port.h>
+#include <sys/utsname.h>
+#include <dlfcn.h>
+
+struct DarwinVersion
+{
+    unsigned long major, minor, revision;
+};
+
+typedef decltype(IODataQueueDequeue)* ioDataQueueDequeueFunctionPtr;
+static ioDataQueueDequeueFunctionPtr ioDataQueueDequeueFunction = nullptr;
+typedef decltype(IODataQueuePeek)* ioDataQueuePeekFunctionPtr;
+static ioDataQueuePeekFunctionPtr ioDataQueuePeekFunction = nullptr;
+
+static void InitDataQueueFunctions();
 
 
 io_connect_t PrjFSService_ConnectToDriver(enum PrjFSServiceUserClientType clientType)
@@ -122,3 +136,98 @@ bool PrjFSService_DataQueueInit(
     return false;
 }
 
+IOReturn DataQueue_Dequeue(IODataQueueMemory* dataQueue, void* data, uint32_t* dataSize)
+{
+    if (nullptr == ioDataQueueDequeueFunction)
+    {
+        InitDataQueueFunctions();
+    }
+    return ioDataQueueDequeueFunction(dataQueue, data, dataSize);
+}
+
+IODataQueueEntry* DataQueue_Peek(IODataQueueMemory* dataQueue)
+{
+    if (nullptr == ioDataQueuePeekFunction)
+    {
+        InitDataQueueFunctions();
+    }
+    return ioDataQueuePeekFunction(dataQueue);
+}
+
+
+static bool GetDarwinVersion(DarwinVersion& outVersion)
+{
+    utsname unameInfo = {};
+    if (0 != uname(&unameInfo))
+    {
+        return false;
+    }
+
+    char* fieldEnd = nullptr;
+    unsigned long majorVersion = strtoul(unameInfo.release, &fieldEnd, 10);
+    if (nullptr == fieldEnd || *fieldEnd != '.')
+    {
+        return false;
+    }
+
+    unsigned long minorVersion = strtoul(fieldEnd + 1, &fieldEnd, 10);
+    if (nullptr == fieldEnd || (*fieldEnd != '.' && *fieldEnd != '\0'))
+    {
+        return false;
+    }
+
+    outVersion.major = majorVersion;
+    outVersion.minor = minorVersion;
+    outVersion.revision = 0;
+
+    if (*fieldEnd != '\0')
+    {
+        unsigned long revision = strtoul(fieldEnd + 1, &fieldEnd, 10);
+        if (nullptr == fieldEnd || (*fieldEnd != '.' && *fieldEnd != '\0'))
+        {
+            return false;
+        }
+        outVersion.revision = revision;
+    }
+
+    return true;
+}
+
+static void InitDataQueueFunctions()
+{
+    ioDataQueueDequeueFunction = &IODataQueueDequeue;
+    ioDataQueuePeekFunction = &IODataQueuePeek;
+
+    DarwinVersion osVersion = {};
+    if (!GetDarwinVersion(osVersion))
+    {
+        return;
+    }
+
+    if ((osVersion.major == 17 && osVersion.minor >= 7) // macOS 10.13.6+
+        || (osVersion.major == 18 && osVersion.minor == 0)) // macOS 10.14(.0) exactly
+    {
+        void* dataQueueLibrary = dlopen("libSharedDataQueue.dylib", RTLD_LAZY);
+        if (nullptr == dataQueueLibrary)
+        {
+            fprintf(stderr, "Error opening data queue client library: %s\n", dlerror());
+        }
+        else
+        {
+            void* sym = dlsym(dataQueueLibrary, "IODataQueueDequeue");
+            if (nullptr != sym)
+            {
+                ioDataQueueDequeueFunction = reinterpret_cast<ioDataQueueDequeueFunctionPtr>(sym);
+            }
+
+            sym = dlsym(dataQueueLibrary, "IODataQueuePeek");
+            if (nullptr != sym)
+            {
+                ioDataQueuePeekFunction = reinterpret_cast<ioDataQueuePeekFunctionPtr>(sym);
+            }
+
+            // Allow the dataQueueLibrary handle to leak; if we called dlclose(),
+            // the library would be unloaded, breaking our function pointers.
+        }
+    }
+}
diff --git a/ProjFS.Mac/PrjFSLib/PrjFSUser.hpp b/ProjFS.Mac/PrjFSLib/PrjFSUser.hpp
@@ -23,3 +23,6 @@ bool PrjFSService_DataQueueInit(
     uint32_t clientPortType,
     uint32_t clientMemoryType,
     dispatch_queue_t eventHandlingQueue);
+
+IODataQueueEntry* DataQueue_Peek(IODataQueueMemory* dataQueue);
+IOReturn DataQueue_Dequeue(IODataQueueMemory* dataQueue, void* data, uint32_t* dataSize);
diff --git a/ProjFS.Mac/PrjFSLib/prjfs-log/prjfs-log.cpp b/ProjFS.Mac/PrjFSLib/prjfs-log/prjfs-log.cpp
@@ -44,7 +44,7 @@ int main(int argc, const char * argv[])
 
         while(true)
         {
-            IODataQueueEntry* entry = IODataQueuePeek(dataQueue.queueMemory);
+            IODataQueueEntry* entry = DataQueue_Peek(dataQueue.queueMemory);
             if(entry == nullptr)
             {
                 break;
@@ -65,7 +65,7 @@ int main(int argc, const char * argv[])
                 lineCount++;
             }
 
-            IODataQueueDequeue(dataQueue.queueMemory, nullptr, nullptr);
+            DataQueue_Dequeue(dataQueue.queueMemory, nullptr, nullptr);
         }
     });
     dispatch_resume(dataQueue.dispatchSource);