C API

Introduction

The C API offers bindings over the C++ API. The VM class’ methods are replaced by C functions that receive an object of type VMInstanceRef as a first parameter.

This API is compatible with QBDIPreload on Linux and macOS.

VM object

type VMInstanceRef

An abstract pointer to the VM object.

void qbdi_initVM(VMInstanceRef *instance, const char *cpu, const char **mattrs, Options opts)

Create and initialize a VM instance.

Parameters
  • instance[out] VM instance created.

  • cpu[in] A C string naming the CPU model to use. If NULL, the default architecture CPU model is used (see LLVM documentation for more details).

  • mattrs[in] A NULL terminated array of C strings specifying the attributes of the cpu model. If NULL, no additional features are specified.

  • opts[in] The options to enable in the VM

void qbdi_terminateVM(VMInstanceRef instance)

Destroy an instance of VM. This method mustn’t be called when the VM runs.

Parameters

instance[in] VM instance.

Options

Options qbdi_getOptions(VMInstanceRef instance)

Get the current Options

Parameters

instance[in] VM instance.

Returns

The current options of the VM

void qbdi_setOptions(VMInstanceRef instance, Options options)

Set the Options This method mustn’t be called when the VM runs.

Parameters
  • instance[in] VM instance.

  • options[in] The new options of the VM.

State management

GPRState *qbdi_getGPRState(VMInstanceRef instance)

Obtain the current general purpose register state.

Parameters

instance[in] VM instance.

Returns

A structure containing the General Purpose Registers state.

FPRState *qbdi_getFPRState(VMInstanceRef instance)

Obtain the current floating point register state.

Parameters

instance[in] VM instance.

Returns

A structure containing the Floating Point Registers state.

void qbdi_setGPRState(VMInstanceRef instance, GPRState *gprState)

Set the GPR state

Parameters
  • instance[in] VM instance.

  • gprState[in] A structure containing the General Purpose Registers state.

void qbdi_setFPRState(VMInstanceRef instance, FPRState *fprState)

Set the FPR state

Parameters
  • instance[in] VM instance.

  • fprState[in] A structure containing the Floating Point Registers state.

Instrumentation range

Addition

void qbdi_addInstrumentedRange(VMInstanceRef instance, rword start, rword end)

Add an address range to the set of instrumented address ranges.

Parameters
  • instance[in] VM instance.

  • start[in] Start address of the range (included).

  • end[in] End address of the range (excluded).

bool qbdi_addInstrumentedModule(VMInstanceRef instance, const char *name)

Add the executable address ranges of a module to the set of instrumented address ranges.

Parameters
  • instance[in] VM instance.

  • name[in] The module’s name.

Returns

True if at least one range was added to the instrumented ranges.

bool qbdi_addInstrumentedModuleFromAddr(VMInstanceRef instance, rword addr)

Add the executable address ranges of a module to the set of instrumented address ranges using an address belonging to the module.

Parameters
  • instance[in] VM instance.

  • addr[in] An address contained by module’s range.

Returns

True if at least one range was added to the instrumented ranges.

bool qbdi_instrumentAllExecutableMaps(VMInstanceRef instance)

Adds all the executable memory maps to the instrumented range set.

Parameters

instance[in] VM instance.

Returns

True if at least one range was added to the instrumented ranges.

Removal

void qbdi_removeInstrumentedRange(VMInstanceRef instance, rword start, rword end)

Remove an address range from the set of instrumented address ranges.

Parameters
  • instance[in] VM instance.

  • start[in] Start address of the range (included).

  • end[in] End address of the range (excluded).

bool qbdi_removeInstrumentedModule(VMInstanceRef instance, const char *name)

Remove the executable address ranges of a module from the set of instrumented address ranges.

Parameters
  • instance[in] VM instance.

  • name[in] The module’s name.

Returns

True if at least one range was removed from the instrumented ranges.

bool qbdi_removeInstrumentedModuleFromAddr(VMInstanceRef instance, rword addr)

Remove the executable address ranges of a module from the set of instrumented address ranges using an address belonging to the module.

Parameters
  • instance[in] VM instance.

  • addr[in] An address contained by module’s range.

Returns

True if at least one range was removed from the instrumented ranges.

void qbdi_removeAllInstrumentedRanges(VMInstanceRef instance)

Remove all instrumented ranges.

Parameters

instance[in] VM instance.

Callback management

InstCallback

uint32_t qbdi_addCodeCB(VMInstanceRef instance, InstPosition pos, InstCallback cbk, void *data, int priority)

Register a callback event for a specific instruction event.

Parameters
  • instance[in] VM instance.

  • pos[in] Relative position of the event callback (QBDI_PREINST / QBDI_POSTINST).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

  • priority[in] The priority of the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

uint32_t qbdi_addCodeAddrCB(VMInstanceRef instance, rword address, InstPosition pos, InstCallback cbk, void *data, int priority)

Register a callback for when a specific address is executed.

Parameters
  • instance[in] VM instance.

  • address[in] Code address which will trigger the callback.

  • pos[in] Relative position of the callback (QBDI_PREINST / QBDI_POSTINST).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

  • priority[in] The priority of the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

uint32_t qbdi_addCodeRangeCB(VMInstanceRef instance, rword start, rword end, InstPosition pos, InstCallback cbk, void *data, int priority)

Register a callback for when a specific address range is executed.

Parameters
  • instance[in] VM instance.

  • start[in] Start of the address range which will trigger the callback.

  • end[in] End of the address range which will trigger the callback.

  • pos[in] Relative position of the callback (QBDI_PREINST / QBDI_POSTINST).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

  • priority[in] The priority of the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

uint32_t qbdi_addMnemonicCB(VMInstanceRef instance, const char *mnemonic, InstPosition pos, InstCallback cbk, void *data, int priority)

Register a callback event if the instruction matches the mnemonic.

Parameters
  • instance[in] VM instance.

  • mnemonic[in] Mnemonic to match.

  • pos[in] Relative position of the event callback (QBDI_PREINST / QBDI_POSTINST).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

  • priority[in] The priority of the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

VMEvent

uint32_t qbdi_addVMEventCB(VMInstanceRef instance, VMEvent mask, VMCallback cbk, void *data)

Register a callback event for a specific VM event.

Parameters
  • instance[in] VM instance.

  • mask[in] A mask of VM event type which will trigger the callback.

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

MemoryAccess

uint32_t qbdi_addMemAccessCB(VMInstanceRef instance, MemoryAccessType type, InstCallback cbk, void *data, int priority)

Register a callback event for every memory access matching the type bitfield made by the instructions.

Parameters
  • instance[in] VM instance.

  • type[in] A mode bitfield: either QBDI_MEMORY_READ, QBDI_MEMORY_WRITE or both (QBDI_MEMORY_READ_WRITE).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

  • priority[in] The priority of the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

uint32_t qbdi_addMemAddrCB(VMInstanceRef instance, rword address, MemoryAccessType type, InstCallback cbk, void *data)

Add a virtual callback which is triggered for any memory access at a specific address matching the access type. Virtual callbacks are called via callback forwarding by a gate callback triggered on every memory access. This incurs a high performance cost.

Parameters
  • instance[in] VM instance.

  • address[in] Code address which will trigger the callback.

  • type[in] A mode bitfield: either QBDI_MEMORY_READ, QBDI_MEMORY_WRITE or both (QBDI_MEMORY_READ_WRITE).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

uint32_t qbdi_addMemRangeCB(VMInstanceRef instance, rword start, rword end, MemoryAccessType type, InstCallback cbk, void *data)

Add a virtual callback which is triggered for any memory access in a specific address range matching the access type. Virtual callbacks are called via callback forwarding by a gate callback triggered on every memory access. This incurs a high performance cost.

Parameters
  • instance[in] VM instance.

  • start[in] Start of the address range which will trigger the callback.

  • end[in] End of the address range which will trigger the callback.

  • type[in] A mode bitfield: either QBDI_MEMORY_READ, QBDI_MEMORY_WRITE or both (QBDI_MEMORY_READ_WRITE).

  • cbk[in] A function pointer to the callback.

  • data[in] User defined data passed to the callback.

Returns

The id of the registered instrumentation (or QBDI_INVALID_EVENTID in case of failure).

InstrRuleCallback

uint32_t qbdi_addInstrRule(VMInstanceRef instance, InstrRuleCallbackC cbk, AnalysisType type, void *data)

Add a custom instrumentation rule to the VM.

Parameters
  • instance[in] VM instance.

  • cbk[in] A function pointer to the callback

  • type[in] Analyse type needed for this instruction function pointer to the callback

  • data[in] User defined data passed to the callback.

Returns

The id of the registered instrumentation (or VMError::INVALID_EVENTID in case of failure).

uint32_t qbdi_addInstrRuleRange(VMInstanceRef instance, rword start, rword end, InstrRuleCallbackC cbk, AnalysisType type, void *data)

Add a custom instrumentation rule to the VM for a range of address

Parameters
  • instance[in] VM instance.

  • start[in] Begin of the range of address where apply the rule

  • end[in] End of the range of address where apply the rule

  • cbk[in] A function pointer to the callback

  • type[in] Analyse type needed for this instruction function pointer to the callback

  • data[in] User defined data passed to the callback.

Returns

The id of the registered instrumentation (or VMError::INVALID_EVENTID in case of failure).

Removal

bool qbdi_deleteInstrumentation(VMInstanceRef instance, uint32_t id)

Remove an instrumentation.

Parameters
  • instance[in] VM instance.

  • id[in] The id of the instrumentation to remove.

Returns

True if instrumentation has been removed.

void qbdi_deleteAllInstrumentations(VMInstanceRef instance)

Remove all the registered instrumentations.

Parameters

instance[in] VM instance.

Run

bool qbdi_run(VMInstanceRef instance, rword start, rword stop)

Start the execution by the DBI from a given address (and stop when another is reached). This method mustn’t be called when the VM already runs.

Parameters
  • instance[in] VM instance.

  • start[in] Address of the first instruction to execute.

  • stop[in] Stop the execution when this instruction is reached.

Returns

True if at least one block has been executed.

bool qbdi_call(VMInstanceRef instance, rword *retval, rword function, uint32_t argNum, ...)

Call a function using the DBI (and its current state). This method mustn’t be called when the VM already runs.

Example:

// perform (with QBDI) a call similar to (*funcPtr)(42);
uint8_t *fakestack = NULL;
VMInstanceRef vm;
qbdi_initVM(&vm, NULL, NULL);
GPRState* gprState = qbdi_getGPRState(vm);
qbdi_allocateVirtualStack(gprState, 0x1000000, &fakestack);
qbdi_addInstrumentedModuleFromAddr(vm, funcPtr);
rword retVal;
qbdi_call(vm, &retVal, funcPtr, 1, 42);

Parameters
  • instance[in] VM instance.

  • [retval][in] Pointer to the returned value (optional).

  • function[in] Address of the function start instruction.

  • argNum[in] The number of arguments in the variadic list.

  • ...[in] A variadic list of arguments.

Returns

True if at least one block has been executed.

bool qbdi_callA(VMInstanceRef instance, rword *retval, rword function, uint32_t argNum, const rword *args)

Call a function using the DBI (and its current state). This method mustn’t be called when the VM already runs.

Parameters
  • instance[in] VM instance.

  • [retval][in] Pointer to the returned value (optional).

  • function[in] Address of the function start instruction.

  • argNum[in] The number of arguments in the variadic list.

  • args[in] Arguments as an array of rword values.

Returns

True if at least one block has been executed.

bool qbdi_callV(VMInstanceRef instance, rword *retval, rword function, uint32_t argNum, va_list ap)

Call a function using the DBI (and its current state). This method mustn’t be called when the VM already runs.

Parameters
  • instance[in] VM instance.

  • [retval][in] Pointer to the returned value (optional).

  • function[in] Address of the function start instruction.

  • argNum[in] The number of arguments in the variadic list.

  • ap[in] An stdarg va_list object.

Returns

True if at least one block has been executed.

InstAnalysis

const InstAnalysis *qbdi_getInstAnalysis(const VMInstanceRef instance, AnalysisType type)

Obtain the analysis of the current instruction. Analysis results are cached in the VM. The validity of the returned pointer is only guaranteed until the end of the callback, else a deepcopy of the structure is required. This method must only be used in an InstCallback.

Parameters
  • instance[in] VM instance.

  • type[in] Properties to retrieve during analysis.

Returns

A InstAnalysis structure containing the analysis result.

const InstAnalysis *qbdi_getCachedInstAnalysis(const VMInstanceRef instance, rword address, AnalysisType type)

Obtain the analysis of a cached instruction. Analysis results are cached in the VM. The validity of the returned pointer is only guaranteed until the end of the callback or a call to a noconst method of the VM instance.

Parameters
  • instance[in] VM instance.

  • address[in] The address of the instruction to analyse.

  • type[in] Properties to retrieve during analysis.

Returns

A InstAnalysis structure containing the analysis result. null if the instruction isn’t in the cache.

MemoryAccess

MemoryAccess *qbdi_getInstMemoryAccess(VMInstanceRef instance, size_t *size)

Obtain the memory accesses made by the last executed instruction. The method should be called in an InstCallback. Return NULL and a size of 0 if the instruction made no memory access.

Parameters
  • instance[in] VM instance.

  • size[out] Will be set to the number of elements in the returned array.

Returns

An array of memory accesses made by the instruction.

MemoryAccess *qbdi_getBBMemoryAccess(VMInstanceRef instance, size_t *size)

Obtain the memory accesses made by the last executed basic block. The method should be called in a VMCallback with QBDI_SEQUENCE_EXIT. Return NULL and a size of 0 if the basic block made no memory access.

Parameters
  • instance[in] VM instance.

  • size[out] Will be set to the number of elements in the returned array.

Returns

An array of memory accesses made by the basic block.

bool qbdi_recordMemoryAccess(VMInstanceRef instance, MemoryAccessType type)

Add instrumentation rules to log memory access using inline instrumentation and instruction shadows.

Parameters
  • instance[in] VM instance.

  • type[in] Memory mode bitfield to activate the logging for: either QBDI_MEMORY_READ, QBDI_MEMORY_WRITE or both (QBDI_MEMORY_READ_WRITE).

Returns

True if inline memory logging is supported, False if not or in case of error.

Cache management

bool qbdi_precacheBasicBlock(VMInstanceRef instance, rword pc)

Pre-cache a known basic block This method mustn’t be called when the VM runs.

Parameters
  • instance[in] VM instance.

  • pc[in] Start address of a basic block

Returns

True if basic block has been inserted in cache.

void qbdi_clearCache(VMInstanceRef instance, rword start, rword end)

Clear a specific address range from the translation cache.

Parameters
  • instance[in] VM instance.

  • start[in] Start of the address range to clear from the cache.

  • end[in] End of the address range to clear from the cache.

void qbdi_clearAllCache(VMInstanceRef instance)

Clear the entire translation cache.

Parameters

instance[in] VM instance.

Register state

type rword

An integer of the size of a register

  • uint32_t for X86

  • uint64_t for X86_64

struct GPRState

General Purpose Register context.

For X86 architecture:


typedef struct QBDI_ALIGNED(4) {
  rword eax;
  rword ebx;
  rword ecx;
  rword edx;
  rword esi;
  rword edi;
  rword ebp;
  rword esp;
  rword eip;
  rword eflags;
} GPRState;

For X86_64 architecture:


typedef struct QBDI_ALIGNED(8) {
  rword rax;
  rword rbx;
  rword rcx;
  rword rdx;
  rword rsi;
  rword rdi;
  rword r8;
  rword r9;
  rword r10;
  rword r11;
  rword r12;
  rword r13;
  rword r14;
  rword r15;
  rword rbp;
  rword rsp;
  rword rip;
  rword eflags;
  // Only backup and restore with OPT_ENABLE_FS_GS
  rword fs;
  rword gs;
} GPRState;
struct FPRState

Floating Point Register context.

For X86 architecture:


typedef struct QBDI_ALIGNED(16) {
  union {
    FPControl fcw; /* x87 FPU control word */
    uint16_t rfcw;
  };
  union {
    FPStatus fsw; /* x87 FPU status word */
    uint16_t rfsw;
  };
  uint8_t ftw;        /* x87 FPU tag word */
  uint8_t rsrv1;      /* reserved */
  uint16_t fop;       /* x87 FPU Opcode */
  uint32_t ip;        /* x87 FPU Instruction Pointer offset */
  uint16_t cs;        /* x87 FPU Instruction Pointer Selector */
  uint16_t rsrv2;     /* reserved */
  uint32_t dp;        /* x87 FPU Instruction Operand(Data) Pointer offset */
  uint16_t ds;        /* x87 FPU Instruction Operand(Data) Pointer Selector */
  uint16_t rsrv3;     /* reserved */
  uint32_t mxcsr;     /* MXCSR Register state */
  uint32_t mxcsrmask; /* MXCSR mask */
  MMSTReg stmm0;      /* ST0/MM0   */
  MMSTReg stmm1;      /* ST1/MM1  */
  MMSTReg stmm2;      /* ST2/MM2  */
  MMSTReg stmm3;      /* ST3/MM3  */
  MMSTReg stmm4;      /* ST4/MM4  */
  MMSTReg stmm5;      /* ST5/MM5  */
  MMSTReg stmm6;      /* ST6/MM6  */
  MMSTReg stmm7;      /* ST7/MM7  */
  char xmm0[16];      /* XMM 0  */
  char xmm1[16];      /* XMM 1  */
  char xmm2[16];      /* XMM 2  */
  char xmm3[16];      /* XMM 3  */
  char xmm4[16];      /* XMM 4  */
  char xmm5[16];      /* XMM 5  */
  char xmm6[16];      /* XMM 6  */
  char xmm7[16];      /* XMM 7  */
  char reserved[14 * 16];
  char ymm0[16]; /* YMM0[255:128] */
  char ymm1[16]; /* YMM1[255:128] */
  char ymm2[16]; /* YMM2[255:128] */
  char ymm3[16]; /* YMM3[255:128] */
  char ymm4[16]; /* YMM4[255:128] */
  char ymm5[16]; /* YMM5[255:128] */
  char ymm6[16]; /* YMM6[255:128] */
  char ymm7[16]; /* YMM7[255:128] */
} FPRState;

For X86_64 architecture:


typedef struct QBDI_ALIGNED(16) {
  union {
    FPControl fcw; /* x87 FPU control word */
    uint16_t rfcw;
  };
  union {
    FPStatus fsw; /* x87 FPU status word */
    uint16_t rfsw;
  };
  uint8_t ftw;        /* x87 FPU tag word */
  uint8_t rsrv1;      /* reserved */
  uint16_t fop;       /* x87 FPU Opcode */
  uint32_t ip;        /* x87 FPU Instruction Pointer offset */
  uint16_t cs;        /* x87 FPU Instruction Pointer Selector */
  uint16_t rsrv2;     /* reserved */
  uint32_t dp;        /* x87 FPU Instruction Operand(Data) Pointer offset */
  uint16_t ds;        /* x87 FPU Instruction Operand(Data) Pointer Selector */
  uint16_t rsrv3;     /* reserved */
  uint32_t mxcsr;     /* MXCSR Register state */
  uint32_t mxcsrmask; /* MXCSR mask */
  MMSTReg stmm0;      /* ST0/MM0   */
  MMSTReg stmm1;      /* ST1/MM1  */
  MMSTReg stmm2;      /* ST2/MM2  */
  MMSTReg stmm3;      /* ST3/MM3  */
  MMSTReg stmm4;      /* ST4/MM4  */
  MMSTReg stmm5;      /* ST5/MM5  */
  MMSTReg stmm6;      /* ST6/MM6  */
  MMSTReg stmm7;      /* ST7/MM7  */
  char xmm0[16];      /* XMM 0  */
  char xmm1[16];      /* XMM 1  */
  char xmm2[16];      /* XMM 2  */
  char xmm3[16];      /* XMM 3  */
  char xmm4[16];      /* XMM 4  */
  char xmm5[16];      /* XMM 5  */
  char xmm6[16];      /* XMM 6  */
  char xmm7[16];      /* XMM 7  */
  char xmm8[16];      /* XMM 8  */
  char xmm9[16];      /* XMM 9  */
  char xmm10[16];     /* XMM 10  */
  char xmm11[16];     /* XMM 11  */
  char xmm12[16];     /* XMM 12  */
  char xmm13[16];     /* XMM 13  */
  char xmm14[16];     /* XMM 14  */
  char xmm15[16];     /* XMM 15  */
  char reserved[6 * 16];
  char ymm0[16];  /* YMM0[255:128] */
  char ymm1[16];  /* YMM1[255:128] */
  char ymm2[16];  /* YMM2[255:128] */
  char ymm3[16];  /* YMM3[255:128] */
  char ymm4[16];  /* YMM4[255:128] */
  char ymm5[16];  /* YMM5[255:128] */
  char ymm6[16];  /* YMM6[255:128] */
  char ymm7[16];  /* YMM7[255:128] */
  char ymm8[16];  /* YMM8[255:128] */
  char ymm9[16];  /* YMM9[255:128] */
  char ymm10[16]; /* YMM10[255:128] */
  char ymm11[16]; /* YMM11[255:128] */
  char ymm12[16]; /* YMM12[255:128] */
  char ymm13[16]; /* YMM13[255:128] */
  char ymm14[16]; /* YMM14[255:128] */
  char ymm15[16]; /* YMM15[255:128] */
} FPRState;
struct MMSTReg

Public Members

char reg[10]
char rsrv[6]
struct FPControl

Public Members

uint16_t invalid
uint16_t denorm
uint16_t zdiv
uint16_t ovrfl
uint16_t undfl
uint16_t precis
uint16_t __pad0__
uint16_t pc
uint16_t rc
uint16_t __pad1__
uint16_t __pad2__
struct FPStatus

Public Members

uint16_t invalid
uint16_t denorm
uint16_t zdiv
uint16_t ovrfl
uint16_t undfl
uint16_t precis
uint16_t stkflt
uint16_t errsumm
uint16_t c0
uint16_t c1
uint16_t c2
uint16_t tos
uint16_t c3
uint16_t busy
REG_RETURN
REG_BP
REG_SP
REG_PC
NUM_GPR

Callback

typedef VMAction (*InstCallback)(VMInstanceRef vm, GPRState *gprState, FPRState *fprState, void *data)

Instruction callback function type.

Param vm

[in] VM instance of the callback.

Param gprState

[in] A structure containing the state of the General Purpose Registers. Modifying it affects the VM execution accordingly.

Param fprState

[in] A structure containing the state of the Floating Point Registers. Modifying it affects the VM execution accordingly.

Param data

[in] User defined data which can be defined when registering the callback.

Return

The callback result used to signal subsequent actions the VM needs to take.

typedef VMAction (*VMCallback)(VMInstanceRef vm, const VMState *vmState, GPRState *gprState, FPRState *fprState, void *data)

VM callback function type.

Param vm

[in] VM instance of the callback.

Param vmState

[in] A structure containing the current state of the VM.

Param gprState

[in] A structure containing the state of the General Purpose Registers. Modifying it affects the VM execution accordingly.

Param fprState

[in] A structure containing the state of the Floating Point Registers. Modifying it affects the VM execution accordingly.

Param data

[in] User defined data which can be defined when registering the callback.

Return

The callback result used to signal subsequent actions the VM needs to take.

typedef void (*InstrRuleCallbackC)(VMInstanceRef vm, const InstAnalysis *inst, InstrRuleDataVec cbks, void *data)

Instrumentation rule callback function type for C API.

Param vm

[in] VM instance of the callback.

Param inst

[in] AnalysisType of the current instrumented Instruction.

Param cbks

[in] An object to add the callback to apply for this instruction. InstCallback can be add with qbdi_addInstrRuleData.

Param data

[in] User defined data which can be defined when registering the callback.

void qbdi_addInstrRuleData(InstrRuleDataVec cbks, InstPosition position, InstCallback cbk, void *data, int priority)

Add a callback for the current instruction

Parameters
  • cbks[in] InstrRuleDataVec given in argument

  • position[in] Relative position of the callback (QBDI_PREINST / QBDI_POSTINST).

  • cbk[in] A function pointer to the callback

  • data[in] User defined data passed to the callback.

  • priority[in] Priority of the callback

type InstrRuleDataVec

An abstract type to append InstCallback for the current instruction

enum InstPosition

Position relative to an instruction.

Values:

enumerator QBDI_PREINST

Positioned before the instruction.

enumerator QBDI_POSTINST

Positioned after the instruction.

enum CallbackPriority

Priority of callback

A callback with an higher priority will be call before a callback with a lower priority.

ie:

  1. CBpre(p = 10)

  2. CBpre(p = 0)

  3. CBpre(p = -10)

  4. instrumented instruction

  5. CBpost(p = 10)

  6. CBpost(p = 0)

  7. CBpost(p = -10)

When the MemoryAccess API is used in a callback, the priority of the callback must not be greater than PRIORITY_MEMACCESS_LIMIT

Values:

enumerator QBDI_PRIORITY_DEFAULT

Default priority for callback

enumerator QBDI_PRIORITY_MEMACCESS_LIMIT

Maximum priority if getInstMemoryAccess is used in the callback

enum VMAction

The callback results.

Values:

enumerator QBDI_CONTINUE

The execution of the basic block continues.

enumerator QBDI_SKIP_INST

Available only with PREINST InstCallback. The instruction and the remained PREINST callbacks are skip. The execution continue with the POSTINST instruction.

We recommand to used this result with a low priority PREINST callback in order to emulate the instruction without skipping the POSTINST callback.

enumerator QBDI_SKIP_PATCH

Available only with InstCallback. The current instruction and the reminding callback (PRE and POST) are skip. The execution continues to the next instruction.

For instruction that change the instruction pointer (jump/call/ret), BREAK_TO_VM must be used insted of SKIP.

SKIP can break the record of MemoryAccess for the current instruction.

enumerator QBDI_BREAK_TO_VM

The execution breaks and returns to the VM causing a complete reevaluation of the execution state. A BREAK_TO_VM is needed to ensure that modifications of the Program Counter or the program code are taken into account.

enumerator QBDI_STOP

Stops the execution of the program. This causes the run function to return early.

InstAnalysis

enum AnalysisType

Instruction analysis type

Values:

enumerator QBDI_ANALYSIS_INSTRUCTION

Instruction analysis (address, mnemonic, …)

enumerator QBDI_ANALYSIS_DISASSEMBLY

Instruction disassembly

enumerator QBDI_ANALYSIS_OPERANDS

Instruction operands analysis

enumerator QBDI_ANALYSIS_SYMBOL

Instruction symbol

struct InstAnalysis

Structure containing analysis results of an instruction provided by the VM.

Public Members

const char *mnemonic

LLVM mnemonic (warning: NULL if !ANALYSIS_INSTRUCTION)

rword address

Instruction address

uint32_t instSize

Instruction size (in bytes)

CPUMode cpuMode

Instruction CPU mode

bool affectControlFlow

true if instruction affects control flow

bool isBranch

true if instruction acts like a ‘jump’

bool isCall

true if instruction acts like a ‘call’

bool isReturn

true if instruction acts like a ‘return’

bool isCompare

true if instruction is a comparison

bool isPredicable

true if instruction contains a predicate (~is conditional)

bool isMoveImm

true if this instruction is a move immediate (including conditional moves) instruction.

bool mayLoad

true if QBDI detects a load for this instruction

bool mayStore

true if QBDI detects a store for this instruction

uint32_t loadSize

size of the expected read access, may be 0 with mayLoad if the size isn’t determined

uint32_t storeSize

size of the expected write access, may be 0 with mayStore if the size isn’t determined

ConditionType condition

Condition associated with the instruction

char *disassembly

Instruction disassembly (warning: NULL if !ANALYSIS_DISASSEMBLY)

RegisterAccessType flagsAccess

Flag access type (noaccess, r, w, rw) (warning: REGISTER_UNUSED if !ANALYSIS_OPERANDS)

uint8_t numOperands

Number of operands used by the instruction

OperandAnalysis *operands

Structure containing analysis results of an operand provided by the VM. (warning: NULL if !ANALYSIS_OPERANDS)

const char *symbol

Instruction symbol (warning: NULL if !ANALYSIS_SYMBOL or not found)

uint32_t symbolOffset

Instruction symbol offset

const char *module

Instruction module name (warning: NULL if !ANALYSIS_SYMBOL or not found)

uint32_t analysisType

INTERNAL: Instruction analysis type (this should NOT be used)

enum ConditionType

Instruction Condition

Values:

enumerator QBDI_CONDITION_NONE

The instruction is unconditionnal

enumerator QBDI_CONDITION_ALWAYS

The instruction is always true

enumerator QBDI_CONDITION_NEVER

The instruction is always false

enumerator QBDI_CONDITION_EQUALS

Equals (‘==’)

enumerator QBDI_CONDITION_NOT_EQUALS

Not Equals (‘!=’)

enumerator QBDI_CONDITION_ABOVE

Above (‘>’ unsigned)

enumerator QBDI_CONDITION_BELOW_EQUALS

Below or Equals (‘<=’ unsigned)

enumerator QBDI_CONDITION_ABOVE_EQUALS

Above or Equals (‘>=’ unsigned)

enumerator QBDI_CONDITION_BELOW

Below (‘<’ unsigned)

enumerator QBDI_CONDITION_GREAT

Great (‘>’ signed)

enumerator QBDI_CONDITION_LESS_EQUALS

Less or Equals (‘<=’ signed)

enumerator QBDI_CONDITION_GREAT_EQUALS

Great or Equals (‘>=’ signed)

enumerator QBDI_CONDITION_LESS

Less (‘<’ signed)

enumerator QBDI_CONDITION_EVEN

Even

enumerator QBDI_CONDITION_ODD

Odd

enumerator QBDI_CONDITION_OVERFLOW

Overflow

enumerator QBDI_CONDITION_NOT_OVERFLOW

Not Overflow

enumerator QBDI_CONDITION_SIGN

Sign

enumerator QBDI_CONDITION_NOT_SIGN

Not Sign

struct OperandAnalysis

Structure containing analysis results of an operand provided by the VM.

Public Members

OperandType type

Operand type

OperandFlag flag

Operand flag

rword value

Operand value (if immediate), or register Id

uint8_t size

Operand size (in bytes)

uint8_t regOff

Sub-register offset in register (in bits)

int16_t regCtxIdx

Register index in VM state (< 0 if not know)

const char *regName

Register name

RegisterAccessType regAccess

Register access type (r, w, rw)

enum OperandType

Operand type

Values:

enumerator QBDI_OPERAND_INVALID

Invalid operand

enumerator QBDI_OPERAND_IMM

Immediate operand

enumerator QBDI_OPERAND_GPR

Register operand

enumerator QBDI_OPERAND_PRED

Predicate operand

enumerator QBDI_OPERAND_FPR

Float register operand

enumerator QBDI_OPERAND_SEG

Segment or unsupported register operand

enum OperandFlag

Values:

enumerator QBDI_OPERANDFLAG_NONE

No flag

enumerator QBDI_OPERANDFLAG_ADDR

The operand is used to compute an address

enumerator QBDI_OPERANDFLAG_PCREL

The value of the operand is PC relative

enumerator QBDI_OPERANDFLAG_UNDEFINED_EFFECT

The operand role isn’t fully defined

enumerator QBDI_OPERANDFLAG_IMPLICIT

The operand is implicit

enum RegisterAccessType

Access type (R/W/RW) of a register operand

Values:

enumerator QBDI_REGISTER_UNUSED

Unused register

enumerator QBDI_REGISTER_READ

Register read access

enumerator QBDI_REGISTER_WRITE

Register write access

enumerator QBDI_REGISTER_READ_WRITE

Register read/write access

MemoryAccess

struct MemoryAccess

Describe a memory access

Public Members

rword instAddress

Address of instruction making the access

rword accessAddress

Address of accessed memory

rword value

Value read from / written to memory

uint16_t size

Size of memory access (in bytes)

MemoryAccessType type

Memory access type (READ / WRITE)

MemoryAccessFlags flags

Memory access flags

enum MemoryAccessType

Memory access type (read / write / …)

Values:

enumerator QBDI_MEMORY_READ

Memory read access

enumerator QBDI_MEMORY_WRITE

Memory write access

enumerator QBDI_MEMORY_READ_WRITE

Memory read/write access

enum MemoryAccessFlags

Memory access flags

Values:

enumerator QBDI_MEMORY_NO_FLAGS
enumerator QBDI_MEMORY_UNKNOWN_SIZE

The size of the access isn’t known.

enumerator QBDI_MEMORY_MINIMUM_SIZE

The given size is a minimum size.

enumerator QBDI_MEMORY_UNKNOWN_VALUE

The value of the access is unknown or hasn’t been retrived.

VMEvent

enum VMEvent

Values:

enumerator QBDI_NO_EVENT
enumerator QBDI_SEQUENCE_ENTRY

Triggered when the execution enters a sequence.

enumerator QBDI_SEQUENCE_EXIT

Triggered when the execution exits from the current sequence.

enumerator QBDI_BASIC_BLOCK_ENTRY

Triggered when the execution enters a basic block.

enumerator QBDI_BASIC_BLOCK_EXIT

Triggered when the execution exits from the current basic block.

enumerator QBDI_BASIC_BLOCK_NEW

Triggered when the execution enters a new (~unknown) basic block.

enumerator QBDI_EXEC_TRANSFER_CALL

Triggered when the ExecBroker executes an execution transfer.

enumerator QBDI_EXEC_TRANSFER_RETURN

Triggered when the ExecBroker returns from an execution transfer.

enumerator QBDI_SYSCALL_ENTRY

Not implemented.

enumerator QBDI_SYSCALL_EXIT

Not implemented.

enumerator QBDI_SIGNAL

Not implemented.

struct VMState

Structure describing the current VM state

Public Members

VMEvent event

The event(s) which triggered the callback (must be checked using a mask: event & BASIC_BLOCK_ENTRY).

rword basicBlockStart

The current basic block start address which can also be the execution transfer destination.

rword basicBlockEnd

The current basic block end address which can also be the execution transfer destination.

rword sequenceStart

The current sequence start address which can also be the execution transfer destination.

rword sequenceEnd

The current sequence end address which can also be the execution transfer destination.

rword lastSignal

Not implemented.

Memory management

Allocation

void *qbdi_alignedAlloc(size_t size, size_t align)

Allocate a block of memory of a specified sized with an aligned base address.

Parameters
  • size[in] Allocation size in bytes.

  • align[in] Base address alignement in bytes.

Returns

Pointer to the allocated memory or NULL in case an error was encountered.

bool qbdi_allocateVirtualStack(GPRState *ctx, uint32_t stackSize, uint8_t **stack)

Allocate a new stack and setup the GPRState accordingly. The allocated stack needs to be freed with alignedFree().

Parameters
  • ctx[in] GPRState which will be setup to use the new stack.

  • stackSize[in] Size of the stack to be allocated.

  • stack[out] The newly allocated stack pointer will be returned in the variable pointed by stack.

Returns

True if stack allocation was successfull.

void qbdi_alignedFree(void *ptr)

Free a block of aligned memory allocated with alignedAlloc.

Parameters

ptr[in] Pointer to the allocated memory.

void qbdi_simulateCall(GPRState *ctx, rword returnAddress, uint32_t argNum, ...)

Simulate a call by modifying the stack and registers accordingly.

Parameters
  • ctx[in] GPRState where the simulated call will be setup. The state needs to point to a valid stack for example setup with allocateVirtualStack().

  • returnAddress[in] Return address of the call to simulate.

  • argNum[in] The number of arguments in the variadic list.

  • ...[in] A variadic list of arguments.

void qbdi_simulateCallV(GPRState *ctx, rword returnAddress, uint32_t argNum, va_list ap)

Simulate a call by modifying the stack and registers accordingly (stdarg version).

Parameters
  • ctx[in] GPRState where the simulated call will be setup. The state needs to point to a valid stack for example setup with allocateVirtualStack().

  • returnAddress[in] Return address of the call to simulate.

  • argNum[in] The number of arguments in the va_list object.

  • ap[in] An stdarg va_list object.

void qbdi_simulateCallA(GPRState *ctx, rword returnAddress, uint32_t argNum, const rword *args)

Simulate a call by modifying the stack and registers accordingly (C array version).

Parameters
  • ctx[in] GPRState where the simulated call will be setup. The state needs to point to a valid stack for example setup with allocateVirtualStack().

  • returnAddress[in] Return address of the call to simulate.

  • argNum[in] The number of arguments in the array args.

  • args[in] An array or arguments.

Exploration

char **qbdi_getModuleNames(size_t *size)

Get a list of all the module names loaded in the process memory. If no modules are found, size is set to 0 and this function returns NULL.

Parameters

size[out] Will be set to the number of strings in the returned array.

Returns

An array of C strings, each one containing the name of a loaded module. This array needs to be free’d by the caller by repetively calling free() on each of its element then finally on the array itself.

qbdi_MemoryMap *qbdi_getCurrentProcessMaps(bool full_path, size_t *size)

Get a list of all the memory maps (regions) of the current process.

Parameters
  • full_path[in] Return the full path of the module in name field

  • size[out] Will be set to the number of strings in the returned array.

Returns

An array of MemoryMap object.

qbdi_MemoryMap *qbdi_getRemoteProcessMaps(rword pid, bool full_path, size_t *size)

Get a list of all the memory maps (regions) of a process.

Parameters
  • pid[in] The identifier of the process.

  • full_path[in] Return the full path of the module in name field

  • size[out] Will be set to the number of strings in the returned array.

Returns

An array of MemoryMap object.

void qbdi_freeMemoryMapArray(qbdi_MemoryMap *arr, size_t size)

Free an array of memory maps objects.

Parameters
  • arr[in] An array of MemoryMap object.

  • size[in] Number of elements in the array.

struct qbdi_MemoryMap

Map of a memory area (region).

Public Members

rword start

Range start value.

rword end

Range end value (always excluded).

qbdi_Permission permission

Region access rights (PF_READ, PF_WRITE, PF_EXEC).

char *name

Region name or path (useful when a region is mapping a module).

enum qbdi_Permission

Memory access rights.

Values:

enumerator QBDI_PF_NONE

No access

enumerator QBDI_PF_READ

Read access

enumerator QBDI_PF_WRITE

Write access

enumerator QBDI_PF_EXEC

Execution access

Other globals

enum Options

Values:

enumerator QBDI_NO_OPT

Default value

enumerator QBDI_OPT_DISABLE_FPR

Disable all operation on FPU (SSE, AVX, SIMD). May break the execution if the target use the FPU

enumerator QBDI_OPT_DISABLE_OPTIONAL_FPR

Disable context switch optimisation when the target execblock doesn’t used FPR

enumerator QBDI_OPT_ATT_SYNTAX

Used the AT&T syntax for instruction disassembly

enumerator QBDI_OPT_ENABLE_FS_GS

Enable Backup/Restore of FS/GS segment. This option uses the instructions (RD|WR)(FS|GS)BASE that must be supported by the operating system

enum VMError

QBDI Error values

Values:

enumerator QBDI_INVALID_EVENTID

Mark a returned event id as invalid

Miscellaneous

Version

const char *qbdi_getVersion(uint32_t *version)

Return QBDI version.

Parameters

version[out] QBDI version encoded as an unsigned integer (0xMMmmpp).

Returns

QBDI version as a string (major.minor.patch).

Log

enum LogPriority

Each log has a priority (or level) which can be used to control verbosity. In production builds, only Warning and Error logs are kept.

Values:

enumerator QBDI_DEBUG

Debug logs

enumerator QBDI_INFO

Info logs (default)

enumerator QBDI_WARNING

Warning logs

enumerator QBDI_ERROR

Error logs

enumerator QBDI_DISABLE

Disable logs message

void qbdi_setLogFile(const char *filename, bool truncate)

Redirect logs to a file.

Parameters
  • filename[in] the path of the file to append the log

  • truncate[in] Set to true to clear the file before append the log

void qbdi_setLogConsole()

Write log to the console (stderr)

void qbdi_setLogDefault()

Write log to the default location (stderr for linux, android_logger for android)

void qbdi_setLogPriority(LogPriority priority)

Enable logs matching priority.

Parameters

priority[in] Filter logs with greater or equal priority.