Merge pull request #23 from ganyao114/short_method

single instruction hook

app/src/main/java/com/swift/sandhook/MyApp.java

@@ -5,7 +5,6 @@
 import android.os.Build;
 import android.util.Log;
 
-import com.swift.sandhook.nativehook.NativeHook;
 import com.swift.sandhook.test.TestClass;
 import com.swift.sandhook.testHookers.ActivityHooker;
 import com.swift.sandhook.testHookers.CtrHook;

nativehook/src/main/cpp/archs/arm/arm32/assembler/assembler_arm32.cpp

@@ -177,4 +177,8 @@ void AssemblerA32::Nop16() {
     Mov(IP, IP);
 }
 
+void AssemblerA32::Hvc(U16 num) {
+    Emit(reinterpret_cast<BaseUnit*>(new INST_T32(HVC)(num)));
+}
+
 

nativehook/src/main/cpp/archs/arm/arm32/assembler/assembler_arm32.h

@@ -77,6 +77,8 @@ namespace SandHook {
 
             void Nop16();
 
+            void Hvc(U16 num);
+
         public:
             CodeContainer code_container = CodeContainer(nullptr);
         };

nativehook/src/main/cpp/archs/arm/arm32/hook/hook_arm32.cpp

@@ -3,6 +3,7 @@
 //
 
 #include <log.h>
+#include <cstdlib>
 #include "code_relocate_arm32.h"
 #include "hook_arm32.h"
 #include "code_buffer.h"
@@ -18,7 +19,7 @@ using namespace SandHook::Utils;
 #include "assembler_arm32.h"
 using namespace SandHook::RegistersA32;
 void *InlineHookArm32Android::Hook(void *origin, void *replace) {
-    AutoLock lock(hookLock);
+    AutoLock lock(hook_lock);
 
     void* origin_code;
     if (IsThumbCode((Addr) origin)) {
@@ -74,7 +75,7 @@ IMPORT_SHELLCODE(BP_SHELLCODE)
 IMPORT_LABEL(callback_addr_s, Addr)
 IMPORT_LABEL(origin_addr_s, Addr)
 bool InlineHookArm32Android::BreakPoint(void *origin, void (*callback)(REG *)) {
-    AutoLock lock(hookLock);
+    AutoLock lock(hook_lock);
 
     void* origin_code;
     if (IsThumbCode((Addr) origin)) {
@@ -126,3 +127,61 @@ bool InlineHookArm32Android::BreakPoint(void *origin, void (*callback)(REG *)) {
 
     return true;
 }
+
+void *InlineHookArm32Android::SingleInstHook(void *origin, void *replace) {
+    if (!InitForSingleInstHook()) {
+        return nullptr;
+    }
+    AutoLock lock(hook_lock);
+
+    void* origin_code;
+    if (IsThumbCode((Addr) origin)) {
+        origin_code = GetThumbCodeAddress(origin);
+    } else {
+        LOGE("hook %d error!, only support thumb2 now!", origin);
+        return nullptr;
+    }
+
+    void* backup = nullptr;
+    AssemblerA32 assembler_backup(backup_buffer);
+
+    StaticCodeBuffer inline_buffer = StaticCodeBuffer(reinterpret_cast<Addr>(origin_code));
+    AssemblerA32 assembler_inline(&inline_buffer);
+    CodeContainer* code_container_inline = &assembler_inline.code_container;
+
+    //build inline trampoline
+#define __ assembler_inline.
+    __ Hvc(static_cast<U16>(hook_infos.size()));
+#undef __
+
+    //build backup method
+    CodeRelocateA32 relocate = CodeRelocateA32(assembler_backup);
+    backup = relocate.Relocate(origin, code_container_inline->Size(), nullptr);
+#define __ assembler_backup.
+    Label* origin_addr_label = new Label();
+    ALIGN_FOR_LDR
+    __ Ldr(PC, origin_addr_label);
+    __ Emit(origin_addr_label);
+    __ Emit((Addr) GetThumbPC(reinterpret_cast<void *>(reinterpret_cast<Addr>(origin_code) + relocate.cur_offset)));
+    __ Finish();
+#undef __
+
+    hook_infos.push_back({origin, replace, GetThumbPC(backup)});
+
+    //commit inline trampoline
+    assembler_inline.Finish();
+    return GetThumbPC(backup);
+}
+
+void InlineHookArm32Android::ExceptionHandler(int num, sigcontext *context) {
+    InstT32 *code = reinterpret_cast<InstT32*>(context->arm_pc);
+    if (!IS_OPCODE_T32(*code, HVC)) {
+        abort();
+    }
+    INST_T32(HVC) hvc(code);
+    hvc.Disassemble();
+    if (hvc.imme >= hook_infos.size())
+        return;
+    HookInfo &hook_info = hook_infos[hvc.imme];
+    context->arm_pc = reinterpret_cast<U32>(hook_info.replace);
+}

nativehook/src/main/cpp/archs/arm/arm32/hook/hook_arm32.h

@@ -5,24 +5,23 @@
 #pragma once
 
 #include "hook.h"
+#include <vector>
 
 namespace SandHook {
     namespace Hook {
 
         class InlineHookArm32Android : public InlineHook {
         public:
-            inline InlineHookArm32Android() {
-                hookLock = new std::mutex();
-            };
-            inline ~InlineHookArm32Android() {
-                delete hookLock;
-            }
             void *Hook(void *origin, void *replace) override;
 
             bool BreakPoint(void *point, void (*callback)(REG *)) override;
 
-        protected:
-            std::mutex* hookLock;
+            void *SingleInstHook(void *origin, void *replace) override;
+
+            void ExceptionHandler(int num, sigcontext *context) override;
+
+        private:
+            std::vector<HookInfo> hook_infos;
         };
 
     }

nativehook/src/main/cpp/archs/arm/arm32/inst/inst_code_arm32.h

@@ -40,4 +40,5 @@ enum class InstCodeT32 : InstCode {
     LDR_UIMM,
     MOV_MOVT_IMM,
     SUB_IMM,
+    HVC
 };

nativehook/src/main/cpp/archs/arm/arm32/inst/inst_struct_t32.h

@@ -95,3 +95,12 @@ DEFINE_STRUCT_T32(SUB_IMM) {
     InstT32 imm3:3;
     InstT32 opcode2:1;
 };
+
+DEFINE_OPCODE_T32(HVC_1, 0b111101111110)
+DEFINE_OPCODE_T32(HVC_2, 0b1000)
+DEFINE_STRUCT_T32(HVC) {
+    InstT32 imm4:4;
+    InstT32 opcode1:12;
+    InstT32 imm12:12;
+    InstT32 opcode2:4;
+};

nativehook/src/main/cpp/archs/arm/arm32/inst/inst_t32.cpp

@@ -239,3 +239,19 @@ void T32_LDR_IMM::Assemble() {
 
 T32_SUB_IMM::T32_SUB_IMM(void *inst) : InstructionT32(inst) {
 }
+
+
+T32_HVC::T32_HVC(void *inst) : InstructionT32(inst) {}
+
+T32_HVC::T32_HVC(U16 imme) : imme(imme) {}
+
+void T32_HVC::Disassemble() {
+    imme = static_cast<U16>(COMBINE(Get()->imm4, Get()->imm12, 12));
+}
+
+void T32_HVC::Assemble() {
+    SET_OPCODE_MULTI(HVC, 1);
+    SET_OPCODE_MULTI(HVC, 2);
+    Get()->imm12 = BITS(imme, 0, 11);
+    Get()->imm4 = BITS(imme, 12, 15);
+}

nativehook/src/main/cpp/archs/arm/arm32/inst/inst_t32.h

@@ -280,6 +280,23 @@ namespace SandHook {
 
         };
 
+
+        DEFINE_INST(HVC) {
+        public:
+            T32_HVC(void *inst);
+
+            T32_HVC(U16 imme);
+
+            DEFINE_IS_EXT(HVC, TEST_INST_OPCODE(HVC, 1) && TEST_INST_OPCODE(HVC, 2))
+
+            void Disassemble() override;
+
+            void Assemble() override;
+
+        public:
+            U16 imme;
+        };
+
     }
 }
 

nativehook/src/main/cpp/archs/arm/arm64/hook/hook_arm64.cpp

@@ -2,6 +2,7 @@
 // Created by swift on 2019/5/23.
 //
 
+#include <cstdlib>
 #include "hook_arm64.h"
 #include "code_buffer.h"
 #include "lock.h"
@@ -131,3 +132,53 @@ bool InlineHookArm64Android::BreakPoint(void *point, void (*callback)(REG regs[]
 
     return true;
 }
+
+
+void *InlineHookArm64Android::SingleInstHook(void *origin, void *replace) {
+    if (!InitForSingleInstHook()) {
+        return nullptr;
+    }
+    AutoLock lock(hook_lock);
+    void* backup = nullptr;
+    AssemblerA64 assembler_backup(backup_buffer);
+
+    StaticCodeBuffer inline_buffer = StaticCodeBuffer(reinterpret_cast<Addr>(origin));
+    AssemblerA64 assembler_inline(&inline_buffer);
+    CodeContainer* code_container_inline = &assembler_inline.code_container;
+
+    //build inline trampoline
+#define __ assembler_inline.
+    __ Hvc(static_cast<U16>(hook_infos.size()));
+#undef __
+
+    //build backup method
+    CodeRelocateA64 relocate = CodeRelocateA64(assembler_backup);
+    backup = relocate.Relocate(origin, code_container_inline->Size(), nullptr);
+#define __ assembler_backup.
+    Label* origin_addr_label = new Label();
+    __ Ldr(IP1, origin_addr_label);
+    __ Br(IP1);
+    __ Emit(origin_addr_label);
+    __ Emit((Addr) origin + code_container_inline->Size());
+    __ Finish();
+#undef __
+
+    hook_infos.push_back({origin, replace, backup});
+
+    //commit inline trampoline
+    assembler_inline.Finish();
+    return backup;
+}
+
+void InlineHookArm64Android::ExceptionHandler(int num, sigcontext *context) {
+    InstA64 *code = reinterpret_cast<InstA64*>(context->pc);
+    if (!IS_OPCODE_A64(*code, EXCEPTION_GEN)) {
+        abort();
+    }
+    INST_A64(EXCEPTION_GEN) hvc(code);
+    hvc.Disassemble();
+    if (hvc.imme >= hook_infos.size())
+        return;
+    HookInfo &hook_info = hook_infos[hvc.imme];
+    context->pc = reinterpret_cast<U64>(hook_info.replace);
+}

nativehook/src/main/cpp/archs/arm/arm64/hook/hook_arm64.h

@@ -5,13 +5,21 @@
 #pragma once
 
 #include "hook.h"
+#include <vector>
 
 namespace SandHook {
     namespace Hook {
         class InlineHookArm64Android : public InlineHook {
         public:
             void *Hook(void *origin, void *replace) override;
             bool BreakPoint(void *point, void (*callback)(REG[])) override;
+
+            void *SingleInstHook(void *origin, void *replace) override;
+
+            void ExceptionHandler(int num, sigcontext *context) override;
+
+        private:
+            std::vector<HookInfo> hook_infos;
         };
     }
 }

nativehook/src/main/cpp/elf/elf.cpp

@@ -90,7 +90,7 @@ ElfImg::ElfImg(const char *elf) {
     }
 
     //load module rang
-    baseInRam = getModuleBase(elf);
+    baseInRam = GetModuleBase(elf);
 }
 
 ElfImg::~ElfImg() {
@@ -105,7 +105,7 @@ ElfImg::~ElfImg() {
     }
 }
 
-Elf_Addr ElfImg::getSymbOffset(const char *name) {
+Elf_Addr ElfImg::GetSymOffset(const char *name) {
     Elf_Addr _offset = 0;
 
     //search dynmtab
@@ -139,16 +139,16 @@ Elf_Addr ElfImg::getSymbOffset(const char *name) {
     return 0;
 }
 
-Elf_Addr ElfImg::getSymbAddress(const char *name) {
-    Elf_Addr offset = getSymbOffset(name);
+Elf_Addr ElfImg::GetSymAddress(const char *name) {
+    Elf_Addr offset = GetSymOffset(name);
     if (offset > 0 && baseInRam != nullptr) {
         return static_cast<Elf_Addr>((size_t) baseInRam + offset - bias);
     } else {
         return 0;
     }
 }
 
-void *ElfImg::getModuleBase(const char *name) {
+void *ElfImg::GetModuleBase(const char *name) {
     FILE *maps;
     char buff[256];
     off_t load_addr;

nativehook/src/main/cpp/hook/hook.cpp

@@ -1,8 +1,8 @@
 //
 // Created by swift on 2019/5/14.
 //
-
 #include "hook.h"
+#include "lock.h"
 
 #if defined(__arm__)
 #include "hook_arm32.h"
@@ -11,11 +11,34 @@
 #endif
 
 using namespace SandHook::Hook;
+using namespace SandHook::Utils;
 
 CodeBuffer* InlineHook::backup_buffer = new AndroidCodeBuffer();
 
 #if defined(__arm__)
 InlineHook* InlineHook::instance = new InlineHookArm32Android();
 #elif defined(__aarch64__)
 InlineHook* InlineHook::instance = new InlineHookArm64Android();
-#endif
+#endif
+
+void InterruptHandler(int signum, siginfo_t* siginfo, void* uc) {
+    if (signum != SIGILL)
+        return;
+    sigcontext &context = reinterpret_cast<ucontext_t *>(uc)->uc_mcontext;
+    InlineHook::instance->ExceptionHandler(signum, &context);
+}
+
+bool InlineHook::InitForSingleInstHook() {
+    AutoLock lock(hook_lock);
+    if (inited)
+        return true;
+    struct sigaction sig{};
+    sigemptyset(&sig.sa_mask);
+    // Notice: remove this flag if needed.
+    sig.sa_flags = SA_SIGINFO;
+    sig.sa_sigaction = InterruptHandler;
+    if (sigaction(SIGILL, &sig, nullptr) != -1) {
+        inited = true;
+    }
+    return inited;
+}

nativehook/src/main/cpp/includes/elf.h

@@ -44,11 +44,11 @@ namespace SandHook {
 
             ElfImg(const char* elf);
 
-            Elf_Addr getSymbOffset(const char* name);
+            Elf_Addr GetSymOffset(const char *name);
 
-            static void* getModuleBase(const char* name);
+            static void* GetModuleBase(const char *name);
 
-            Elf_Addr getSymbAddress(const char* name);
+            Elf_Addr GetSymAddress(const char *name);
 
             ~ElfImg();