/*

** $Id: lundump.c,v 2.22 2012/05/08 13:53:33 roberto Exp $

** load precompiled Lua chunks

** See Copyright Notice in lua.h

*/

#include <string.h>

#define lundump_c

#define LUA_CORE

#include "lua.h"

#include "ldebug.h"

#include "ldo.h"

#include "lfunc.h"

#include "lmem.h"

#include "lobject.h"

#include "lstring.h"

#include "lundump.h"

#include "lzio.h"

#include "lopcodes.h"

typedef struct {

lua_State* L;

ZIO* Z;

Mbuffer* b;

const char* name;

} LoadState;

static l_noret error(LoadState* S, const char* why)

{

luaO_pushfstring(S->L,"%s: %s precompiled chunk",S->name,why);

luaD_throw(S->L,LUA_ERRSYNTAX);

}

#define LoadMem(S,b,n,size) LoadBlock(S,b,(n)*(size))

#define LoadByte(S) (lu_byte)LoadChar(S)

#define LoadVar(S,x) LoadMem(S,&x,1,sizeof(x))

#define LoadVector(S,b,n,size) LoadMem(S,b,n,size)

#define bytecode_assert(S,cond) if (!(cond)) error(S, "invalid bytecode in");

static void verify_jump(LoadState* S, int pc, Instruction inst, Proto* f)

{

bytecode_assert(S, GETARG_A(inst) <= f->maxstacksize);

// verify jump is at least within func body, this does allow jumps which violate var-initialization rules still

// but at most you get something that was already on the Lua stack

bytecode_assert(S, pc + 1 + GETARG_sBx(inst) < f->sizecode);

bytecode_assert(S, pc + 1 + GETARG_sBx(inst) >= 0);

}

static void verify_pc_increment(LoadState* S, int pc, Proto* f)

{

bytecode_assert(S, pc + 2 < f->sizecode); // + 1 from the incrment after each instruction, + 1 from the extra increment.

}

static void luai_verify_last_inst(LoadState* S, Proto* f)

{

Instruction inst = f->code[f->sizecode - 1];

OpCode op = GET_OPCODE(inst);

if (op == OP_JMP || op == OP_FORPREP)

{

bytecode_assert(S, GETARG_sBx(inst) < 0); // is an upwards jump, or when 0 it's an infinite loop

return;

}

if (op == OP_RETURN)

return;

bytecode_assert(S, false); // not going to start giving custom error messages, so just assert false

}

static void luai_verifycode(LoadState* S, Proto* f)

{

luai_verify_last_inst(S, f);

// verify all instructions refer to in-range register, upval, and constant indexes

// this is *not* meant to be bulletproof against multi-instruction constructs that

// lead to misuse within the lua stack, but should catch reading off the end of

// const/upval/funcproto lists with nonsensical arguments to VM opcodes.

for (size_t i = 0; i < f->sizecode; i++)

{

Instruction inst = f->code[i];

OpCode op = GET_OPCODE(inst);

switch (op)

{

case OP_LOADK: // A Bx R(A) := Kst(Bx)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_Bx(inst) < f->sizek);

break;

case OP_LOADKX:// A R(A) := Kst(extra arg)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

inst = f->code[++i];

bytecode_assert(S, GET_OPCODE(inst) == OP_EXTRAARG);

bytecode_assert(S, GETARG_Ax(inst) < f->sizek)

break;

case OP_LOADBOOL:// A B C R(A) := (Bool)B; if (C) pc++

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) == 0 || GETARG_B(inst) == 1);

bytecode_assert(S, GETARG_C(inst) == 0 || GETARG_C(inst) == 1);

// any op is valid next (unlike other skips), so validate as normal

// commonly used with an opposite LOADBOOL so that a test/jmp pair

// immediately before runs only one of them

if (GETARG_C(inst) == 1)

verify_pc_increment(S, i, f); // skipping the last inst is not valid however

break;

case OP_LOADNIL:// A B R(A), R(A+1), ..., R(A+B) := nil

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_A(inst) + GETARG_B(inst) < f->maxstacksize);

break;

case OP_GETUPVAL:// A B R(A) := UpValue[B]

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->sizeupvalues);

break;

case OP_GETTABUP:// A B C R(A) := UpValue[B][RK(C)]

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->sizeupvalues);

bytecode_assert(S, ISK(GETARG_C(inst)) ? INDEXK(GETARG_C(inst)) < f->sizek : GETARG_C(inst) < f->maxstacksize);

break;

case OP_SELF:// A B C R(A+1) := R(B); R(A) := R(B)[RK(C)]

bytecode_assert(S, GETARG_A(inst) + 1 < f->maxstacksize);

// fallthrough

case OP_GETTABLE:// A B C R(A) := R(B)[RK(C)]

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, ISK(GETARG_C(inst)) ? INDEXK(GETARG_C(inst)) < f->sizek : GETARG_C(inst) < f->maxstacksize);

break;

case OP_SETTABUP:// A B C UpValue[A][RK(B)] := RK(C)

bytecode_assert(S, GETARG_A(inst) < f->sizeupvalues);

bytecode_assert(S, ISK(GETARG_B(inst)) ? INDEXK(GETARG_B(inst)) < f->sizek : GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, ISK(GETARG_C(inst)) ? INDEXK(GETARG_C(inst)) < f->sizek : GETARG_C(inst) < f->maxstacksize);

break;

case OP_SETUPVAL:// A B UpValue[B] := R(A)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->sizeupvalues);

break;

case OP_NEWTABLE:// A B C R(A) := {} (size = B,C)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

break;

case OP_SETTABLE:// A B C R(A)[RK(B)] := RK(C)

case OP_ADD:// A B C R(A) := RK(B) + RK(C)

case OP_SUB:// A B C R(A) := RK(B) - RK(C)

case OP_MUL:// A B C R(A) := RK(B) * RK(C)

case OP_DIV:// A B C R(A) := RK(B) / RK(C)

case OP_MOD:// A B C R(A) := RK(B) % RK(C)

case OP_POW:// A B C R(A) := RK(B) ^ RK(C)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, ISK(GETARG_B(inst)) ? INDEXK(GETARG_B(inst)) < f->sizek : GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, ISK(GETARG_C(inst)) ? INDEXK(GETARG_C(inst)) < f->sizek : GETARG_C(inst) < f->maxstacksize);

break;

case OP_MOVE:// A B R(A) := R(B)

case OP_UNM: // A B R(A) := -R(B)

case OP_NOT: // A B R(A) := not R(B)

case OP_LEN: // A B R(A) := length of R(B)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->maxstacksize);

break;

case OP_CONCAT:// A B C R(A) := R(B).. ... ..R(C)

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_C(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < GETARG_C(inst));

break;

case OP_JMP:// A sBx pc+=sBx; if (A) close all upvalues >= R(A) + 1

verify_jump(S, i, inst, f);

break;

case OP_EQ:/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */

case OP_LT:/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */

case OP_LE:/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */

bytecode_assert(S, GETARG_A(inst) == 0 || GETARG_A(inst) == 1);

bytecode_assert(S, ISK(GETARG_B(inst)) ? INDEXK(GETARG_B(inst)) < f->sizek : GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, ISK(GETARG_C(inst)) ? INDEXK(GETARG_C(inst)) < f->sizek : GETARG_C(inst) < f->maxstacksize);

inst = f->code[++i];

bytecode_assert(S, GET_OPCODE(inst) == OP_JMP);

verify_jump(S, i, inst, f);

verify_pc_increment(S, i, f);

break;

case OP_TEST:/* A C if not (R(A) <=> C) then pc++ */

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_C(inst) == 0 || GETARG_C(inst) == 1);

inst = f->code[++i];

bytecode_assert(S, GET_OPCODE(inst) == OP_JMP);

verify_jump(S, i, inst, f);

verify_pc_increment(S, i, f);

break;

case OP_TESTSET:/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_B(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_C(inst) == 0 || GETARG_C(inst) == 1);

inst = f->code[++i];

bytecode_assert(S, GET_OPCODE(inst) == OP_JMP);

verify_jump(S, i, inst, f);

verify_pc_increment(S, i, f);

break;

case OP_CALL:// A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) if B=0 use top, if C=0 return var num results and set top

if (GETARG_C(inst) == 0 || GETARG_C(inst) == 1) // C=1 call for 0 results

{

// at least function in a valid register

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

}

else

{

// full return list in valid registers

bytecode_assert(S, GETARG_A(inst) + GETARG_C(inst) - 2 < f->maxstacksize);

}

// fallthrough

case OP_TAILCALL:// A B C return R(A)(R(A+1), ... ,R(A+B-1)) if B=0 use top

if (GETARG_B(inst) == 0 || GETARG_B(inst) == 1) // B=1 call with 0 args

{

// at least function in a valid register

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

}

else

{

// full arg list in valid registers

bytecode_assert(S, GETARG_A(inst) + GETARG_B(inst) - 1 < f->maxstacksize);

}

break;

case OP_RETURN:// A B return R(A), ... ,R(A+B-2) if B=0 use actual top

if (GETARG_B(inst) == 0)

{

// at least *start* in a valid register

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

}

else if (GETARG_B(inst) != 1) // B=1 returns no results, ignoring A entirely

{

bytecode_assert(S, GETARG_A(inst) + GETARG_B(inst) - 2 < f->maxstacksize);

}

break;

case OP_FORLOOP:// A sBx R(A)+=R(A+2); if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }

bytecode_assert(S, GETARG_A(inst) + 3 < f->maxstacksize);

verify_jump(S, i, inst, f); // verifies R(A) and pc+=sBx

break;

case OP_FORPREP:// A sBx R(A)-=R(A+2); pc+=sBx

bytecode_assert(S, GETARG_A(inst) + 2 < f->maxstacksize);

verify_jump(S, i, inst, f); // verifies R(A) and pc+=sBx

break;

case OP_TFORCALL:// A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2))

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_A(inst) + 3 < f->maxstacksize);

bytecode_assert(S, GETARG_C(inst) > 0); // TFORCALL for 0 values is nonsense, would be `for in` with no names

bytecode_assert(S, GETARG_A(inst) + GETARG_C(inst) + 2 < f->maxstacksize);

inst = f->code[++i];

//OP_TFORLOOP: A sBx if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }

bytecode_assert(S, GET_OPCODE(inst) == OP_TFORLOOP);

bytecode_assert(S, GETARG_A(inst) + 1 < f->maxstacksize);

verify_jump(S, i, inst, f); // verifies R(A) and pc+=sBx

break;

case OP_SETLIST:// A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B if B=0 use top, if C=0 use EXTRAARG

// at least *start* in a valid register

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

// if B sets an end, validate that too

if (GETARG_B(inst) != 0)

{

bytecode_assert(S, GETARG_A(inst) + GETARG_B(inst) < f->maxstacksize);

}

// any C is valid, but if it's 0, verify EXTRAARG

if (GETARG_C(inst) == 0)

{

inst = f->code[++i];

bytecode_assert(S, GET_OPCODE(inst) == OP_EXTRAARG);

}

break;

case OP_CLOSURE:// A Bx R(A) := closure(KPROTO[Bx])

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

bytecode_assert(S, GETARG_Bx(inst) < f->sizep);

break;

case OP_VARARG:// A B R(A), R(A+1), ..., R(A+B-2) = vararg, if B==0 then actual num of vararg and set top

// start in a valid register

bytecode_assert(S, GETARG_A(inst) < f->maxstacksize);

if (GETARG_B(inst) != 0)

{

bytecode_assert(S, GETARG_B(inst) != 1); // vararg for no results is nonsense, it sets no registers

bytecode_assert(S, GETARG_A(inst) + GETARG_B(inst) - 2 < f->maxstacksize);

}

break;

case OP_TFORLOOP: // TFORLOOP will always be immediately after TFORCALL and verified/consumed by it, it should never appear on its own

case OP_EXTRAARG: // EXTRAARG will always be consumed by the instruction before it, it should never appear on its own

default: // invalid opcodes

bytecode_assert(S, 0);

break;

}

}

}

static void LoadBlock(LoadState* S, void* b, size_t size)

{

if (luaZ_read(S->Z,b,size)!=0) error(S,"truncated");

}

static int LoadChar(LoadState* S)

{

char x;

LoadVar(S,x);

return x;

}

static int LoadInt(LoadState* S)

{

int x;

LoadVar(S,x);

if (x<0) error(S,"corrupted");

return x;

}

static lua_Number LoadNumber(LoadState* S)

{

lua_Number x;

LoadVar(S,x);

return x;

}

static TString* LoadString(LoadState* S)

{

size_t size;

LoadVar(S,size);

if (size==0)

return luaS_newlstr(S->L,"",0);

else

{

char* s=luaZ_openspace(S->L,S->b,size);

LoadBlock(S,s,size*sizeof(char));

return luaS_newlstr(S->L,s,size-1); /* remove trailing '\0' */

}

}

static void LoadCode(LoadState* S, Proto* f)

{

int n=LoadInt(S);

// minimum function size is 1: a single OP_RET

bytecode_assert(S, n>0);

f->code=luaM_newvector(S->L,n,Instruction);

f->sizecode=n;

LoadVector(S,f->code,n,sizeof(Instruction));

}

static void LoadFunction(LoadState* S, Proto* f);

static void LoadConstants(LoadState* S, Proto* f)

{

int i,n;

n=LoadInt(S);

f->k=luaM_newvector(S->L,n,TValue);

f->sizek=n;

for (i=0; i<n; i++) setnilvalue(&f->k[i]);

for (i=0; i<n; i++)

{

TValue* o=&f->k[i];

int t=LoadChar(S);

switch (t)

{

case LUA_TNIL:

setnilvalue(o);

break;

case LUA_TBOOLEAN:

setbvalue(o,LoadChar(S));

break;

case LUA_TNUMBER:

setnvalue(o,LoadNumber(S));

break;

case LUA_TSTRING:

setsvalue2n(S->L, o, LoadString(S));

break;

default:

bytecode_assert(S, 0);

}

}

n=LoadInt(S);

f->p=luaM_newvector(S->L,n,Proto*);

f->sizep=n;

for (i=0; i<n; i++) f->p[i]=NULL;

for (i=0; i<n; i++)

{

f->p[i]=luaF_newproto(S->L);

LoadFunction(S,f->p[i]);

}

}

static void LoadUpvalues(LoadState* S, Proto* f)

{

int i,n;

n=LoadInt(S);

f->upvalues=luaM_newvector(S->L,n,Upvaldesc);

f->sizeupvalues=n;

for (i=0; i<n; i++) f->upvalues[i].name=NULL;

for (i=0; i<n; i++)

{

f->upvalues[i].instack=LoadByte(S);

f->upvalues[i].idx=LoadByte(S);

}

}

static void LoadDebug(LoadState* S, Proto* f)

{

int i,n;

f->source=LoadString(S);

n=LoadInt(S);

f->lineinfo=luaM_newvector(S->L,n,int);

f->sizelineinfo=n;

LoadVector(S,f->lineinfo,n,sizeof(int));

n=LoadInt(S);

f->locvars=luaM_newvector(S->L,n,LocVar);

f->sizelocvars=n;

for (i=0; i<n; i++)

{

f->locvars[i].varname=LoadString(S);

f->locvars[i].startpc=LoadInt(S);

f->locvars[i].endpc=LoadInt(S);

}

n=LoadInt(S);

for (i=0; i<n; i++) f->upvalues[i].name=LoadString(S);

}

static void LoadFunction(LoadState* S, Proto* f)

{

f->linedefined=LoadInt(S);

f->lastlinedefined=LoadInt(S);

f->numparams=LoadByte(S);

f->is_vararg=LoadByte(S);

f->maxstacksize=LoadByte(S);

LoadCode(S,f);

LoadConstants(S,f);

LoadUpvalues(S,f);

LoadDebug(S,f);

luai_verifycode(S,f);

}

/* the code below must be consistent with the code in luaU_header */

#define N0 LUAC_HEADERSIZE

#define N1 (sizeof(LUA_SIGNATURE)-sizeof(char))

#define N2 N1+2

#define N3 N2+6

static void LoadHeader(LoadState* S)

{

lu_byte h[LUAC_HEADERSIZE];

lu_byte s[LUAC_HEADERSIZE];

luaU_header(h);

memcpy(s,h,sizeof(char)); /* first char already read */

LoadBlock(S,s+sizeof(char),LUAC_HEADERSIZE-sizeof(char));

if (memcmp(h,s,N0)==0) return;

if (memcmp(h,s,N1)!=0) error(S,"not a");

if (memcmp(h,s,N2)!=0) error(S,"version mismatch in");

if (memcmp(h,s,N3)!=0) error(S,"incompatible"); else error(S,"corrupted");

}

/*

** load precompiled chunk

*/

Closure* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, const char* name)

{

LoadState S;

Closure* cl;

if (*name=='@' || *name=='=')

S.name=name+1;

else if (*name==LUA_SIGNATURE[0])

S.name="binary string";

else

S.name=name;

S.L=L;

S.Z=Z;

S.b=buff;

LoadHeader(&S);

cl=luaF_newLclosure(L,1);

setclLvalue(L,L->top,cl); incr_top(L);

cl->l.p=luaF_newproto(L);

LoadFunction(&S,cl->l.p);

if (cl->l.p->sizeupvalues != 1)

{

Proto* p=cl->l.p;

cl=luaF_newLclosure(L,cl->l.p->sizeupvalues);

cl->l.p=p;

setclLvalue(L,L->top-1,cl);

}

return cl;

}

#define MYINT(s) (s[0]-'0')

#define VERSION MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR)

#define FORMAT 0 /* this is the official format */

/*

* make header for precompiled chunks

* if you change the code below be sure to update LoadHeader and FORMAT above

* and LUAC_HEADERSIZE in lundump.h

*/

void luaU_header (lu_byte* h)

{

int x=1;

memcpy(h,LUA_SIGNATURE,sizeof(LUA_SIGNATURE)-sizeof(char));

h+=sizeof(LUA_SIGNATURE)-sizeof(char);

*h++=cast_byte(VERSION);

*h++=cast_byte(FORMAT);

*h++=cast_byte(*(char*)&x); /* endianness */

*h++=cast_byte(sizeof(int));

*h++=cast_byte(sizeof(size_t));

*h++=cast_byte(sizeof(Instruction));

*h++=cast_byte(sizeof(lua_Number));

*h++=cast_byte(((lua_Number)0.5)==0); /* is lua_Number integral? */

memcpy(h,LUAC_TAIL,sizeof(LUAC_TAIL)-sizeof(char));

}