Implement file renaming and relative path handling in NtQueryAttributesFile (#557)

This PR introduces several enhancements, mainly to the file system
syscalls:

- Implements file renaming via `NtSetInformationFile` by adding a
deferred rename mechanism to `file_handle`. The rename operation occurs
when the file handle is closed.
- Adds support for the `RootDirectory` parameter in
`NtQueryAttributesFile` to handle relative file paths.
- Adds support for opening the console output device (`\\??\\CONOUT$`).
- Stubs out the `NtLockVirtualMemory` syscall.
- Fixes an incorrect assertion in `socket_wrapper` that could fire on
`recvfrom` errors.

src/common/utils/file_handle.hpp

@@ -7,6 +7,12 @@ namespace utils
 {
     class file_handle
     {
+        struct rename_information
+        {
+            std::filesystem::path old_filepath;
+            std::filesystem::path new_filepath;
+        };
+
       public:
         file_handle() = default;
 
@@ -80,8 +86,14 @@ namespace utils
             return _ftelli64(this->file_);
         }
 
+        void defer_rename(std::filesystem::path oldname, std::filesystem::path newname)
+        {
+            deferred_rename_ = {.old_filepath = std::move(oldname), .new_filepath = std::move(newname)};
+        }
+
       private:
         FILE* file_{};
+        std::optional<rename_information> deferred_rename_;
 
         void release()
         {
@@ -90,6 +102,13 @@ namespace utils
                 (void)fclose(this->file_);
                 this->file_ = {};
             }
+
+            if (this->deferred_rename_)
+            {
+                std::error_code ec{};
+                std::filesystem::rename(this->deferred_rename_->old_filepath, this->deferred_rename_->new_filepath, ec);
+                this->deferred_rename_ = {};
+            }
         }
     };
 }

src/windows-emulator/network/socket_wrapper.cpp

@@ -111,7 +111,7 @@ namespace network
         const auto res = ::recvfrom(this->socket_.get_socket(), reinterpret_cast<char*>(data.data()), static_cast<send_size>(data.size()),
                                     0, &source.get_addr(), &source_length);
 
-        assert(source.get_size() == source_length);
+        assert(res < 0 || source.get_size() == source_length);
 
         return res;
     }

src/windows-emulator/syscalls.cpp

@@ -132,6 +132,7 @@ namespace syscalls
                                         emulator_pointer buffer, ULONG number_of_bytes_to_read,
                                         emulator_object<ULONG> number_of_bytes_read);
     NTSTATUS handle_NtSetInformationVirtualMemory();
+    BOOL handle_NtLockVirtualMemory();
 
     // syscalls/mutant.cpp:
     NTSTATUS handle_NtReleaseMutant(const syscall_context& c, handle mutant_handle, emulator_object<LONG> previous_count);
@@ -961,6 +962,7 @@ void syscall_dispatcher::add_handlers(std::map<std::string, syscall_handler>& ha
     add_handler(NtQuerySystemInformation);
     add_handler(NtCreateEvent);
     add_handler(NtProtectVirtualMemory);
+    add_handler(NtLockVirtualMemory);
     add_handler(NtOpenDirectoryObject);
     add_handler(NtTraceEvent);
     add_handler(NtAllocateVirtualMemoryEx);

src/windows-emulator/syscalls/file.cpp

@@ -51,7 +51,7 @@ namespace syscalls
                                          const emulator_object<IO_STATUS_BLOCK<EmulatorTraits<Emu64>>> io_status_block,
                                          const uint64_t file_information, const ULONG length, const FILE_INFORMATION_CLASS info_class)
     {
-        const auto* f = c.proc.files.get(file_handle);
+        auto* f = c.proc.files.get(file_handle);
         if (!f)
         {
             if (c.proc.devices.get(file_handle))
@@ -88,7 +88,22 @@ namespace syscalls
 
             c.win_emu.log.warn("--> File rename requested: %s --> %s\n", u16_to_u8(f->name).c_str(), u16_to_u8(new_name).c_str());
 
-            return STATUS_ACCESS_DENIED;
+            std::error_code ec{};
+            bool file_exists = std::filesystem::exists(new_name, ec);
+
+            if (ec)
+            {
+                return STATUS_ACCESS_DENIED;
+            }
+
+            if (!info.ReplaceIfExists && file_exists)
+            {
+                return STATUS_OBJECT_NAME_EXISTS;
+            }
+
+            f->handle.defer_rename(c.win_emu.file_sys.translate(f->name), c.win_emu.file_sys.translate(new_name));
+
+            return STATUS_SUCCESS;
         }
 
         if (info_class == FileBasicInformation)
@@ -886,6 +901,12 @@ namespace syscalls
             return STATUS_SUCCESS;
         }
 
+        if (filename == u"\\??\\CONOUT$")
+        {
+            file_handle.write(STDOUT_HANDLE);
+            return STATUS_SUCCESS;
+        }
+
         file f{};
         f.name = std::move(filename);
 
@@ -1022,8 +1043,19 @@ namespace syscalls
             return STATUS_INVALID_PARAMETER;
         }
 
-        const auto filename =
-            read_unicode_string(c.emu, emulator_object<UNICODE_STRING<EmulatorTraits<Emu64>>>{c.emu, attributes.ObjectName});
+        auto filename = read_unicode_string(c.emu, emulator_object<UNICODE_STRING<EmulatorTraits<Emu64>>>{c.emu, attributes.ObjectName});
+
+        if (attributes.RootDirectory)
+        {
+            const auto* root = c.proc.files.get(attributes.RootDirectory);
+            if (!root)
+            {
+                return STATUS_INVALID_HANDLE;
+            }
+
+            const auto has_separator = root->name.ends_with(u"\\") || root->name.ends_with(u"/");
+            filename = root->name + (has_separator ? u"" : u"\\") + filename;
+        }
 
         c.win_emu.callbacks.on_generic_access("Querying file attributes", filename);
 

src/windows-emulator/syscalls/memory.cpp

@@ -295,4 +295,9 @@ namespace syscalls
     {
         return STATUS_NOT_SUPPORTED;
     }
+
+    BOOL handle_NtLockVirtualMemory()
+    {
+        return TRUE;
+    }
 }

src/windows-emulator/windows_objects.hpp

@@ -186,6 +186,7 @@ struct file : ref_counted_object
     utils::file_handle handle{};
     std::u16string name{};
     std::optional<file_enumeration_state> enumeration_state{};
+    std::optional<std::u16string> deferred_rename;
 
     bool is_file() const
     {