1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 #include "ModuleLoadFrame.h"
8 #include "mozilla/NativeNt.h"
9 #include "mozilla/UniquePtr.h"
10 #include "NtLoaderAPI.h"
11 
12 #include <string.h>
13 
14 #include "WindowsFallbackLoaderAPI.h"
15 
IsNullTerminated(PCUNICODE_STRING aStr)16 static bool IsNullTerminated(PCUNICODE_STRING aStr) {
17   return aStr && (aStr->MaximumLength >= (aStr->Length + sizeof(WCHAR))) &&
18          aStr->Buffer && aStr->Buffer[aStr->Length / sizeof(WCHAR)] == 0;
19 }
20 
21 static mozilla::FallbackLoaderAPI gFallbackLoaderAPI;
22 
23 namespace mozilla {
24 namespace glue {
25 
26 nt::LoaderAPI* ModuleLoadFrame::sLoaderAPI;
27 
28 using GetNtLoaderAPIFn = decltype(&mozilla::GetNtLoaderAPI);
29 
30 /* static */
StaticInit(nt::LoaderObserver * aNewObserver,nt::WinLauncherFunctions * aOutWinLauncherFunctions)31 void ModuleLoadFrame::StaticInit(
32     nt::LoaderObserver* aNewObserver,
33     nt::WinLauncherFunctions* aOutWinLauncherFunctions) {
34   const auto pGetNtLoaderAPI = reinterpret_cast<GetNtLoaderAPIFn>(
35       ::GetProcAddress(::GetModuleHandleW(nullptr), "GetNtLoaderAPI"));
36   if (!pGetNtLoaderAPI) {
37     // This case occurs in processes other than firefox.exe that do not contain
38     // the launcher process blocklist.
39     gFallbackLoaderAPI.SetObserver(aNewObserver);
40     sLoaderAPI = &gFallbackLoaderAPI;
41 
42     if (aOutWinLauncherFunctions) {
43       aOutWinLauncherFunctions->mHandleLauncherError =
44           [](const mozilla::LauncherError&, const char*) {};
45       // We intentionally leave mInitDllBlocklistOOP null to make sure calling
46       // mInitDllBlocklistOOP in non-Firefox hits MOZ_RELEASE_ASSERT.
47     }
48     return;
49   }
50 
51   sLoaderAPI = pGetNtLoaderAPI(aNewObserver);
52   MOZ_ASSERT(sLoaderAPI);
53 
54   if (aOutWinLauncherFunctions) {
55     aOutWinLauncherFunctions->mInitDllBlocklistOOP =
56         sLoaderAPI->GetDllBlocklistInitFn();
57     aOutWinLauncherFunctions->mHandleLauncherError =
58         sLoaderAPI->GetHandleLauncherErrorFn();
59   }
60 }
61 
ModuleLoadFrame(PCUNICODE_STRING aRequestedDllName)62 ModuleLoadFrame::ModuleLoadFrame(PCUNICODE_STRING aRequestedDllName)
63     : mAlreadyLoaded(false),
64       mContext(nullptr),
65       mDllLoadStatus(STATUS_UNSUCCESSFUL),
66       mLoadInfo(sLoaderAPI->ConstructAndNotifyBeginDllLoad(&mContext,
67                                                            aRequestedDllName)) {
68   if (!aRequestedDllName) {
69     return;
70   }
71 
72   UniquePtr<WCHAR[]> nameBuf;
73   const WCHAR* name = nullptr;
74 
75   if (IsNullTerminated(aRequestedDllName)) {
76     name = aRequestedDllName->Buffer;
77   } else {
78     USHORT charLenExclNul = aRequestedDllName->Length / sizeof(WCHAR);
79     USHORT charLenInclNul = charLenExclNul + 1;
80     nameBuf = MakeUnique<WCHAR[]>(charLenInclNul);
81     if (!wcsncpy_s(nameBuf.get(), charLenInclNul, aRequestedDllName->Buffer,
82                    charLenExclNul)) {
83       name = nameBuf.get();
84     }
85   }
86 
87   mAlreadyLoaded = name && !!::GetModuleHandleW(name);
88 }
89 
~ModuleLoadFrame()90 ModuleLoadFrame::~ModuleLoadFrame() {
91   sLoaderAPI->NotifyEndDllLoad(mContext, mDllLoadStatus, std::move(mLoadInfo));
92 }
93 
SetLoadStatus(NTSTATUS aNtStatus,HANDLE aHandle)94 void ModuleLoadFrame::SetLoadStatus(NTSTATUS aNtStatus, HANDLE aHandle) {
95   mDllLoadStatus = aNtStatus;
96   void* baseAddr = mozilla::nt::PEHeaders::HModuleToBaseAddr<void*>(
97       reinterpret_cast<HMODULE>(aHandle));
98   mLoadInfo.mBaseAddr = baseAddr;
99   if (!mAlreadyLoaded) {
100     mLoadInfo.mSectionName = sLoaderAPI->GetSectionName(baseAddr);
101   }
102 }
103 
104 }  // namespace glue
105 }  // namespace mozilla
106