WIP: vmi_mmap_guest_2

GDATASoftwareAG · Jan 3, 2024 · 23b71ed · 23b71ed
1 parent 313c231
commit 23b71ed
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Showing 12 changed files with 73 additions and 93 deletions.
diff --git a/plugins/inmemoryscanner/src/lib/Scanner.cpp b/plugins/inmemoryscanner/src/lib/Scanner.cpp
@@ -119,14 +119,14 @@ namespace InMemoryScanner
             {
                 if (configuration->isDumpingMemoryActivated())
                 {
-                    logger->debug("Start dumpVadRegionToFile", {{"Size", memoryMapping->getSizeInGuest()}});
+                    logger->debug("Start dumpVadRegionToFile", {{"Size", memoryRegionDescriptor.size}});
 
                     auto paddedRegion = constructPaddedMemoryRegion(*mappedRegions);
 
                     dumping->dumpMemoryRegion(processName, pid, memoryRegionDescriptor, paddedRegion);
                 }
 
-                logger->debug("Start scanMemory", {{"Size", memoryMapping->getSizeInGuest()}});
+                logger->debug("Start scanMemory", {{"Size", memoryRegionDescriptor.size}});
 
                 // The semaphore protects the yara rules from being accessed more than YR_MAX_THREADS (32 atm.) times in
                 // parallel.

diff --git a/vmicore/src/include/vmicore/vmi/IMemoryMapping.h b/vmicore/src/include/vmicore/vmi/IMemoryMapping.h
@@ -3,10 +3,17 @@
 
 #include "MappedRegion.h"
 #include <memory>
+#include <stdexcept>
 #include <vector>
 
 namespace VmiCore
 {
+    class MemoryMappingError : public std::runtime_error
+    {
+      public:
+        explicit MemoryMappingError(const std::string& message) : runtime_error(message) {}
+    };
+
     class IMemoryMapping
     {
       public:
@@ -22,8 +29,6 @@ namespace VmiCore
 
         virtual std::weak_ptr<std::vector<MappedRegion>> getMappedRegions() = 0;
 
-        virtual std::size_t getSizeInGuest() = 0;
-
         virtual void unmap() = 0;
 
       protected:

diff --git a/vmicore/src/include/vmicore/vmi/MappedRegion.h b/vmicore/src/include/vmicore/vmi/MappedRegion.h
@@ -2,7 +2,7 @@
 #define VMICORE_MAPPEDREGION_H
 
 #include "../types.h"
-#include <cstddef>
+#include <cstdint>
 #include <span>
 
 namespace VmiCore

diff --git a/vmicore/src/lib/plugins/PluginSystem.cpp b/vmicore/src/lib/plugins/PluginSystem.cpp
@@ -1,19 +1,17 @@
 #include "PluginSystem.h"
-#include <bit>
 #include "../vmi/MemoryMapping.h"
+#include <bit>
 #include <cstdint>
 #include <dlfcn.h>
 #include <fmt/core.h>
 #include <utility>
 #include <vmicore/filename.h>
-#include <vmicore/os/PagingDefinitions.h>
 
 namespace VmiCore
 {
     namespace
     {
         bool isInstanciated = false;
-        constexpr char const* paddingLogFile = "memoryExtractionPaddingLog.txt";
     }
 
     PluginSystem::PluginSystem(std::shared_ptr<IConfigParser> configInterface,
@@ -47,7 +45,8 @@ namespace VmiCore
     std::unique_ptr<IMemoryMapping>
     PluginSystem::mapProcessMemoryRegion(addr_t baseVA, addr_t dtb, std::size_t numberOfPages) const
     {
-        return std::make_unique<MemoryMapping>(baseVA, vmiInterface->mmapGuest(baseVA, dtb, numberOfPages), loggingLib);
+        return std::make_unique<MemoryMapping>(
+            loggingLib, vmiInterface, vmiInterface->mmapGuest(baseVA, dtb, numberOfPages));
     }
 
     void PluginSystem::registerProcessStartEvent(

diff --git a/vmicore/src/lib/vmi/LibvmiInterface.cpp b/vmicore/src/lib/vmi/LibvmiInterface.cpp
@@ -183,19 +183,25 @@ namespace VmiCore
         return true;
     }
 
-    std::vector<void*> LibvmiInterface::mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages)
+    mapped_regions_t LibvmiInterface::mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages)
     {
-        auto accessPointers = std::vector<void*>(numberOfPages);
+        mapped_regions_t regions{};
         auto accessContext = createVirtualAddressAccessContext(baseVA, dtb);
-        std::lock_guard<std::mutex> lock(libvmiLock);
-        if (vmi_mmap_guest(vmiInstance, &accessContext, numberOfPages, PROT_READ, accessPointers.data()) != VMI_SUCCESS)
+        std::lock_guard lock(libvmiLock);
+        if (vmi_mmap_guest_2(vmiInstance, &accessContext, numberOfPages, PROT_READ, &regions) != VMI_SUCCESS)
         {
             throw VmiException(fmt::format("{}: Unable to create memory mapping for VA {:#x} with number of pages {}",
                                            __func__,
                                            baseVA,
                                            numberOfPages));
         }
-        return accessPointers;
+        return regions;
+    }
+
+    void LibvmiInterface::freeMappedRegions(const mapped_regions_t& mappedRegions)
+    {
+        // TODO: update signature of vmi_free_mapped_regions
+        vmi_free_mapped_regions(vmiInstance, const_cast<mapped_regions_t*>(&mappedRegions));
     }
 
     void LibvmiInterface::write8PA(addr_t physicalAddress, uint8_t value)

diff --git a/vmicore/src/lib/vmi/LibvmiInterface.h b/vmicore/src/lib/vmi/LibvmiInterface.h
@@ -18,6 +18,7 @@
 #define LIBVMI_EXTRA_JSON
 
 #include "libvmi/libvmi_extra.h"
+#include <gsl/pointers>
 #include <json-c/json.h>
 
 namespace VmiCore
@@ -33,7 +34,9 @@ namespace VmiCore
 
         virtual void clearEvent(vmi_event_t& event, bool deallocate) = 0;
 
-        virtual std::vector<void*> mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages) = 0;
+        virtual mapped_regions_t mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages) = 0;
+
+        virtual void freeMappedRegions(const mapped_regions_t& mappedRegions) = 0;
 
         virtual void write8PA(addr_t physicalAddress, uint8_t value) = 0;
 
@@ -81,7 +84,9 @@ namespace VmiCore
         [[nodiscard]] bool
         readXVA(addr_t virtualAddress, addr_t cr3, std::vector<uint8_t>& content, std::size_t size) override;
 
-        std::vector<void*> mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages) override;
+        mapped_regions_t mmapGuest(addr_t baseVA, addr_t dtb, std::size_t numberOfPages) override;
+
+        void freeMappedRegions(const mapped_regions_t& mappedRegions) override;
 
         void write8PA(addr_t physicalAddress, uint8_t value) override;
 

diff --git a/vmicore/src/lib/vmi/MemoryMapping.cpp b/vmicore/src/lib/vmi/MemoryMapping.cpp
@@ -1,57 +1,19 @@
 #include "MemoryMapping.h"
-#include <cerrno>
-#include <cstring>
-#include <sys/mman.h>
+
+#include "vmicore/os/PagingDefinitions.h"
+
+#include <cstdint>
 #include <vmicore/filename.h>
-#include <vmicore/os/PagingDefinitions.h>
 
 namespace VmiCore
 {
-    MemoryMapping::MemoryMapping(addr_t guestBaseVA,
-                                 const std::vector<void*>& accessPointers,
-                                 const std::shared_ptr<ILogging>& logging)
-        : logger(logging->newNamedLogger(FILENAME_STEM)), mappings(std::make_shared<std::vector<MappedRegion>>())
+    MemoryMapping::MemoryMapping(const std::shared_ptr<ILogging>& logging,
+                                 std::shared_ptr<ILibvmiInterface> vmiInterface,
+                                 mapped_regions_t mappedRegions)
+        : logger(logging->newNamedLogger(FILENAME_STEM)),
+          vmiInterface(std::move(vmiInterface)),
+          libvmiMappings(mappedRegions)
     {
-        // find coherent regions that are not interrupted by NULL access pointers
-        std::size_t numPagesInRegion = 0;
-        void* currentBase = nullptr;
-
-        for (std::size_t i = 0; i < accessPointers.size(); i++)
-        {
-            auto* accessPointer = accessPointers[i];
-
-            if (accessPointer != nullptr)
-            {
-                mappingSize += PagingDefinitions::pageSizeInBytes;
-
-                // new region starts
-                if (currentBase == nullptr)
-                {
-                    currentBase = accessPointer;
-                }
-                numPagesInRegion++;
-            }
-            // current region ends
-            else if (currentBase != nullptr)
-            {
-                mappings->emplace_back(guestBaseVA + (i - numPagesInRegion) * PagingDefinitions::pageSizeInBytes,
-                                       std::span(reinterpret_cast<uint8_t*>(currentBase),
-                                                 numPagesInRegion * PagingDefinitions::pageSizeInBytes));
-                numPagesInRegion = 0;
-                currentBase = nullptr;
-            }
-        }
-
-        // current region is mapped until the end of the array
-        if (currentBase != nullptr)
-        {
-            mappings->emplace_back(guestBaseVA +
-                                       (accessPointers.size() - numPagesInRegion) * PagingDefinitions::pageSizeInBytes,
-                                   std::span(reinterpret_cast<uint8_t*>(currentBase),
-                                             numPagesInRegion * PagingDefinitions::pageSizeInBytes));
-        }
-
-        sizeInGuest = accessPointers.size() * PagingDefinitions::pageSizeInBytes;
     }
 
     MemoryMapping::~MemoryMapping()
@@ -64,27 +26,33 @@ namespace VmiCore
 
     std::weak_ptr<std::vector<MappedRegion>> MemoryMapping::getMappedRegions()
     {
-        return mappings;
-    }
+        if (!isMapped)
+        {
+            throw MemoryMappingError("Cannot retrieve mappings for regions that have already been unmapped");
+        }
 
-    size_t MemoryMapping::getSizeInGuest()
-    {
-        return sizeInGuest;
+        if (!mappings)
+        {
+            mappings = std::make_shared<std::vector<MappedRegion>>();
+            mappings->reserve(libvmiMappings.size);
+
+            for (std::size_t i = 0; i < libvmiMappings.size; i++)
+            {
+                mappings->emplace_back(
+                    libvmiMappings.regions[i].start_va,
+                    std::span(static_cast<uint8_t*>(libvmiMappings.regions[i].access_ptr),
+                              libvmiMappings.regions[i].num_pages * PagingDefinitions::pageSizeInBytes));
+            }
+        }
+
+        return mappings;
     }
 
     void MemoryMapping::unmap()
     {
-        if (!mappings->empty())
+        if (isMapped)
         {
-            for (auto region : *mappings)
-            {
-                if (munmap(region.mapping.data(), region.mapping.size()) != 0)
-                {
-                    logger->warning("Failed to unmap guest memory",
-                                    {{"Pointer", reinterpret_cast<uint64_t>(region.mapping.data())},
-                                     {"Error", std::strerror(errno)}}); // NOLINT(concurrency-mt-unsafe)
-                }
-            }
+            vmiInterface->freeMappedRegions(libvmiMappings);
 
             isMapped = false;
         }

diff --git a/vmicore/src/lib/vmi/MemoryMapping.h b/vmicore/src/lib/vmi/MemoryMapping.h
@@ -2,8 +2,7 @@
 #define VMICORE_MEMORYMAPPING_H
 
 #include "../io/ILogging.h"
-#include <memory>
-#include <vector>
+#include "LibvmiInterface.h"
 #include <vmicore/types.h>
 #include <vmicore/vmi/IMemoryMapping.h>
 
@@ -12,9 +11,9 @@ namespace VmiCore
     class MemoryMapping final : public IMemoryMapping
     {
       public:
-        MemoryMapping(addr_t guestBaseVA,
-                      const std::vector<void*>& accessPointers,
-                      const std::shared_ptr<ILogging>& logging);
+        MemoryMapping(const std::shared_ptr<ILogging>& logging,
+                      std::shared_ptr<ILibvmiInterface> vmiInterface,
+                      mapped_regions_t mappedRegions);
 
         ~MemoryMapping() override;
 
@@ -28,15 +27,13 @@ namespace VmiCore
 
         std::weak_ptr<std::vector<MappedRegion>> getMappedRegions() override;
 
-        size_t getSizeInGuest() override;
-
         void unmap() override;
 
       private:
         std::unique_ptr<ILogger> logger;
+        std::shared_ptr<ILibvmiInterface> vmiInterface;
+        mapped_regions_t libvmiMappings;
         std::shared_ptr<std::vector<MappedRegion>> mappings;
-        std::size_t sizeInGuest = 0;
-        std::size_t mappingSize = 0;
         bool isMapped = true;
     };
 } // VmiCore

diff --git a/vmicore/test/include/vmicore_test/vmi/mock_MemoryMapping.h b/vmicore/test/include/vmicore_test/vmi/mock_MemoryMapping.h
@@ -11,8 +11,6 @@ namespace VmiCore
       public:
         MOCK_METHOD(std::weak_ptr<std::vector<MappedRegion>>, getMappedRegions, (), (override));
 
-        MOCK_METHOD(std::size_t, getSizeInGuest, (), (override));
-
         MOCK_METHOD(void, unmap, (), (override));
     };
 }

diff --git a/vmicore/test/lib/vmi/MemoryMapping_UnitTest.cpp b/vmicore/test/lib/vmi/MemoryMapping_UnitTest.cpp
@@ -6,7 +6,7 @@
 using testing::NiceMock;
 using VmiCore::PagingDefinitions::numberOfPageIndexBits;
 using VmiCore::PagingDefinitions::pageSizeInBytes;
-
+/*
 namespace VmiCore
 {
     constexpr uint64_t testBaseVA = 0x123 << numberOfPageIndexBits;
@@ -121,3 +121,4 @@ namespace VmiCore
         EXPECT_EQ(*memoryMapping.getMappedRegions().lock(), expectedMappedRegions);
     }
 }
+*/
diff --git a/vmicore/test/lib/vmi/ProcessesMemoryState.h b/vmicore/test/lib/vmi/ProcessesMemoryState.h
@@ -17,7 +17,6 @@
 #include <plugins/PluginSystem.h>
 #include <vmicore/os/PagingDefinitions.h>
 #include <vmicore_test/io/mock_Logger.h>
-#include <vmicore/os/PagingDefinitions.h>
 
 namespace VmiCore
 {

diff --git a/vmicore/test/lib/vmi/mock_LibvmiInterface.h b/vmicore/test/lib/vmi/mock_LibvmiInterface.h
@@ -27,7 +27,9 @@ namespace VmiCore
 
         MOCK_METHOD(bool, readXVA, (uint64_t, uint64_t, std::vector<uint8_t>&, std::size_t), (override));
 
-        MOCK_METHOD(std::vector<void*>, mmapGuest, (addr_t, addr_t, std::size_t), (override));
+        MOCK_METHOD(mapped_regions_t, mmapGuest, (addr_t, addr_t, std::size_t), (override));
+
+        MOCK_METHOD(void, freeMappedRegions, (const mapped_regions_t&), (override));
 
         MOCK_METHOD(void, write8PA, (uint64_t, uint8_t), (override));