radare2/libr/anal/rpnesil.c
2014-06-25 11:43:29 +02:00

834 lines
19 KiB
C

/* radare - LGPL - Copyright 2014 - pancake */
#include <r_anal.h>
#include <r_types.h>
#define FLG(x) R_ANAL_ESIL_FLAG_##x
static int esil_reg_write (RAnalEsil *esil, const char *dst, ut64 num);
static int esil_reg_read (RAnalEsil *esil, const char *regname, ut64 *num);
R_API RAnalEsil *r_anal_esil_new() {
RAnalEsil *esil = R_NEW0 (RAnalEsil);
esil->stackptr = 0;
esil->flags = 0;
return esil;
}
R_API void r_anal_esil_free (RAnalEsil *esil) {
int i;
for (i=0; i<esil->stackptr;i++)
free (esil->stack[i]);
free (esil);
}
static int internal_esil_mem_read(RAnalEsil *esil, ut64 addr, ut8 *buf, int len) {
if (!esil || !esil->anal || !esil->anal->iob.io)
return 0;
return esil->anal->iob.read_at (esil->anal->iob.io, addr, buf, len);
}
static int esil_mem_read(RAnalEsil *esil, ut64 addr, ut8 *buf, int len) {
int i, ret = 0;
if (!buf || !esil)
return 0;
if (esil->hook_mem_read) {
ret = esil->hook_mem_read (esil, addr, buf, len);
}
if (!ret && esil->mem_read) {
ret = esil->mem_read (esil, addr, buf, len);
}
if (esil->debug) {
eprintf ("0x%08"PFMT64x" R> ", addr);
for (i=0;i<len;i++)
eprintf ("%02x", buf[i]);
eprintf ("\n");
}
return ret;
}
static int internal_esil_mem_write (ESIL *esil, ut64 addr, const ut8 *buf, int len) {
if (!esil || !esil->anal || !esil->anal->iob.io)
return 0;
return esil->anal->iob.write_at (esil->anal->iob.io, addr, buf, len);
}
static int esil_mem_write (ESIL *esil, ut64 addr, const ut8 *buf, int len) {
int i, ret = 0;
if (!buf || !esil)
return 0;
if (esil->debug) {
eprintf ("0x%08"PFMT64x" <W ", addr);
for (i=0;i<len;i++)
eprintf ("%02x", buf[i]);
eprintf ("\n");
}
if (esil->hook_mem_write) {
ret = esil->hook_mem_write (esil, addr, buf, len);
}
if (!ret && esil->mem_write) {
ret = esil->mem_write (esil, addr, buf, len);
}
return ret;
}
static int internal_esil_reg_read(RAnalEsil *esil, const char *regname, ut64 *num) {
RRegItem *reg = r_reg_get (esil->anal->reg, regname, -1);
if (reg) {
if (num)
*num = r_reg_get_value (esil->anal->reg, reg);
return 1;
}
return 0;
}
static int internal_esil_reg_write(RAnalEsil *esil, const char *regname, ut64 num) {
RRegItem *reg = r_reg_get (esil->anal->reg, regname, -1);
if (reg) {
r_reg_set_value (esil->anal->reg, reg, num);
return 1;
}
return 0;
}
R_API int r_anal_esil_setup (RAnalEsil *esil, RAnal *anal) {
// register callbacks using this anal module.
// this is: set
esil->debug = 1;
esil->anal = anal;
//esil->user = NULL;
esil->reg_read = internal_esil_reg_read;
esil->reg_write = internal_esil_reg_write;
esil->mem_read = internal_esil_mem_read;
esil->mem_write = internal_esil_mem_write;
return 1;
}
R_API int r_anal_esil_pushnum(RAnalEsil *esil, ut64 num) {
char str[64];
snprintf (str, sizeof (str)-1, "0x%"PFMT64x, num);
return r_anal_esil_push (esil, str);
}
R_API int r_anal_esil_push(RAnalEsil *esil, const char *str) {
if (!str || !esil || !*str || esil->stackptr>30)
return 0;
esil->stack[esil->stackptr++] = strdup (str);
return 1;
}
R_API char *r_anal_esil_pop(RAnalEsil *esil) {
if (esil->stackptr<1)
return NULL;
return esil->stack[--esil->stackptr];
}
static int isnum (RAnalEsil *esil, const char *str, ut64 *num) {
if (*str >= '0' && *str <= '9') {
if (num)
*num = r_num_get (NULL, str);
return 1;
}
if (num)
*num = 0;
return 0;
}
static int isregornum(RAnalEsil *esil, const char *str, ut64 *num) {
if (!esil_reg_read (esil, str, num))
if (!isnum (esil, str, num))
return 0;
return 1;
}
static int esil_reg_write (RAnalEsil *esil, const char *dst, ut64 num) {
int ret = 0;
if (esil->debug) {
eprintf ("%s=0x%"PFMT64x"\n", dst, num);
}
if (esil->hook_reg_write) {
ret = esil->hook_reg_write (esil, dst, num);
if (!ret)
return ret;
}
if (esil->reg_write) {
return esil->reg_write (esil, dst, num);
}
return ret;
}
static int esil_reg_read (RAnalEsil *esil, const char *regname, ut64 *num) {
int ret = 0;
if (num)
*num = 0LL;
if (esil->hook_reg_read) {
ret = esil->hook_reg_read (esil, regname, num);
}
if (!ret && esil->reg_read) {
ret = esil->reg_read (esil, regname, num);
}
if (ret && num && esil->debug) {
eprintf ("%s=0x%"PFMT64x"\n", regname, *num);
}
return ret;
}
static int esil_eq (RAnalEsil *esil) {
int ret = 0;
ut64 num;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && dst && esil_reg_read (esil, dst, NULL)) {
if (isregornum (esil, src, &num)) {
if (num) {
R_BIT_UNSET (&esil->flags, FLG(ZERO));
} else {
R_BIT_SET (&esil->flags, FLG(ZERO));
}
ret = esil_reg_write (esil, dst, num);
} else eprintf ("esil_eq: invalid src\n");
} else {
eprintf ("esil_eq: invalid parameters\n");
}
free (src);
free (dst);
return ret;
}
static int esil_neg(RAnalEsil *esil) {
int ret = 0;
ut64 num;
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &num)) {
num = !num;
r_anal_esil_pushnum (esil, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
free (src);
return ret;
}
static int esil_negeq(RAnalEsil *esil) { //check me
int ret = 0;
ut64 num;
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &num)) {
num = !num;
esil_reg_write (esil, src, num);
ret = 1;
} else {
eprintf ("esil_negeq: empty stack\n");
}
free (src);
return ret;
}
static int esil_andeq(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num &= num2;
esil_reg_write (esil, dst, num);
ret = 1;
} else {
eprintf ("esil_andeq: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_xoreq(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, src, &num)) {
if (src && isregornum (esil, src, &num2)) {
num ^= num2;
esil_reg_write (esil, dst, num);
ret = 1;
} else {
eprintf ("esil_xoreq: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_syscall(RAnalEsil *esil) {
// pop number
// resolve arguments and run syscall handler
eprintf ("SYSCALL: Not yet implemented\n");
return 0;
}
static int esil_cmp(RAnalEsil *esil) {
// pop 2 elements
ut64 num, num2;
// update flags based on given operation
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
if (num == num2) {
R_BIT_SET (&esil->flags, FLG(ZERO));
} else {
R_BIT_UNSET (&esil->flags, FLG(ZERO));
if (num > num2) {
R_BIT_UNSET (&esil->flags, FLG(CARRY));
} else {
R_BIT_SET (&esil->flags, FLG(CARRY));
}
}
return 1;
}
}
return 0;
// +
// -
// = esil->zf=1
// TODO
#if 0
x86 documentation:
CF - carry flag -- Set on high-order bit carry or borrow; cleared otherwise
num>>63
PF - parity flag
(num&0xff)
Set if low-order eight bits of result contain an even number of "1" bits; cleared otherwise
ZF - zero flags
Set if result is zero; cleared otherwise
zf = num?0:1;
SF - sign flag
Set equal to high-order bit of result (0 if positive 1 if negative)
sf = ((st64)num)<0)?1:0;
OF - overflow flag
if (a>0&&b>0 && (a+b)<0)
Set if result is too large a positive number or too small a negative number (excluding sign bit) to fit in destination operand; cleared otherwise
JBE : CF = 1 || ZF = 1
#endif
}
static int esil_ifset(RAnalEsil *esil) {
// set RReg flags acording to esil->flags
//ut64 num = 0;
char *src = r_anal_esil_pop (esil);
eprintf ("UPDATE FLAGS (%s)\n", src);
esil_reg_write (esil, "zf", R_BIT_CHK(&esil->flags, FLG(ZERO)));
esil_reg_write (esil, "cf", R_BIT_CHK(&esil->flags, FLG(CARRY)));
esil_reg_write (esil, "of", R_BIT_CHK(&esil->flags, FLG(OVERFLOW)));
esil_reg_write (esil, "pf", R_BIT_CHK(&esil->flags, FLG(PARITY)));
return 0;
}
static int esil_if(RAnalEsil *esil) {
ut64 num = 0;
char *src = r_anal_esil_pop (esil);
if (src) {
if (!isregornum (esil, src, &num)) {
int zf = R_BIT_CHK (&esil->flags, FLG(ZERO));
int cf = R_BIT_CHK (&esil->flags, FLG(CARRY));
num = 0;
if (!strcmp (src, "z")) {
// equal, zero
if (!zf) num = 1;
} else
if (!strcmp (src, "nz")) {
// different, non-zero
if (zf) num = 1;
} else
if (!strcmp (src, "a")) {
// above
if (!zf && !cf)
num = 1;
} else
if (!strcmp (src, "ae")) {
// above or equal
if (!zf) num = 1;
if (!zf && !cf) num = 1;
} else
if (!strcmp (src, "b")) {
// below
if (!zf && cf)
num = 1;
} else
if (!strcmp (src, "be")) {
// below or equal
if (!zf) num = 1;
}
}
if (!num) {
// condition not matching, skipping until }
esil->skip = R_TRUE;
}
}
return 0;
}
static int esil_lsl(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num <<= num2;
r_anal_esil_pushnum (esil, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_lsleq(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num <<= num2;
esil_reg_write (esil, dst, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_lsr(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num >>= num2;
r_anal_esil_pushnum (esil, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_lsreq(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num >>= num2;
esil_reg_write (esil, dst, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_and(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num &= num2;
r_anal_esil_pushnum (esil, num);
ret = 1;
} else {
eprintf ("esil_neg: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
static int esil_xor(RAnalEsil *esil) {
int ret = 0;
ut64 num, num2;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (dst && esil_reg_read (esil, dst, &num)) {
if (src && isregornum (esil, src, &num2)) {
num ^= num2;
r_anal_esil_pushnum (esil, num);
ret = 1;
} else {
eprintf ("esil_xor: empty stack\n");
}
}
free (src);
free (dst);
return ret;
}
R_API int r_anal_esil_dumpstack (RAnalEsil *esil) {
int i;
if (esil->stackptr<1)
return 0;
eprintf ("StackDump:\n");
for (i=esil->stackptr-1;i>=0; i--) {
eprintf (" [%d] %s\n", i, esil->stack[i]);
}
return 1;
}
static int esil_div(RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
// TODO: check overflow
if (s == 0) {
eprintf ("esil_div: Division by zero!\n");
} else {
r_anal_esil_pushnum (esil, d/s);
}
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_mul(RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
// TODO: check overflow
r_anal_esil_pushnum (esil, d*s);
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_add (RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
// TODO: check overflow
r_anal_esil_pushnum (esil, d+s);
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_addeq (RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
// src -= dst;
// src = src - dst;
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
esil_reg_write (esil, dst, s+d);
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_sub (RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
// TODO: check overflow
r_anal_esil_pushnum (esil, s-d);
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_subeq (RAnalEsil *esil) {
int ret = 0;
ut64 s, d;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
// src -= dst;
// src = src - dst;
if (src && isregornum (esil, src, &s)) {
if (dst && isregornum (esil, dst, &d)) {
esil_reg_write (esil, dst, s-d);
}
} else {
eprintf ("esil_eq: invalid parameters");
}
free (src);
free (dst);
return ret;
}
static int esil_poke1(RAnalEsil *esil) {
int ret = 0;
ut64 num, addr;
ut8 num1;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &num)) {
if (dst && isregornum (esil, dst, &addr)) {
num1 = (ut8)num;
ret = esil_mem_write (esil, addr,
(const ut8*)&num1, 1);
}
}
return ret;
}
static int esil_poke4(RAnalEsil *esil) {
int ret = 0;
ut64 num, addr;
ut32 num4;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &num)) {
if (dst && isregornum (esil, dst, &addr)) {
num4 = (ut32)num;
ret = esil_mem_write (esil, addr,
(const ut8*)&num4, 4);
}
}
return ret;
}
static int esil_peek1(RAnalEsil *esil) {
int ret = 0;
char res[32];
ut64 num;
char *dst = r_anal_esil_pop (esil);
if (dst && isregornum (esil, dst, &num)) {
ut8 buf;
ret = esil_mem_read (esil, num, &buf, 1);
snprintf (res, sizeof (res), "0x%x", buf);
r_anal_esil_push (esil, res);
}
return ret;
}
static int esil_peek2(RAnalEsil *esil) {
int ret = 0;
char res[32];
ut64 num;
char *dst = r_anal_esil_pop (esil);
if (dst && isregornum (esil, dst, &num)) {
ut8 buf[4];
ut16 *n16 = (ut16 *)&buf;
ret = esil_mem_read (esil, num, buf, 2);
snprintf (res, sizeof (res), "0x%hx", *n16);
r_anal_esil_push (esil, res);
}
return ret;
}
static int esil_peek4(RAnalEsil *esil) {
int ret = 0;
char res[32];
ut64 num;
char *dst = r_anal_esil_pop (esil);
if (dst && isregornum (esil, dst, &num)) {
ut8 buf[4];
ut32 *n32 = (ut32 *)&buf;
ret = esil_mem_read (esil, num, buf, 4);
snprintf (res, sizeof (res), "0x%x", *n32);
r_anal_esil_push (esil, res);
}
return ret;
}
static int esil_poke8(RAnalEsil *esil) {
int ret = 0;
ut64 num, addr;
ut64 num8;
char *dst = r_anal_esil_pop (esil);
char *src = r_anal_esil_pop (esil);
if (src && isregornum (esil, src, &num)) {
if (dst && isregornum (esil, dst, &addr)) {
num8 = (ut64)num;
ret = esil_mem_write (esil, addr,
(const ut8*)&num8, sizeof (num8));
}
}
return ret;
}
static int esil_peek8(RAnalEsil *esil) {
int ret = 0;
char res[32];
ut64 num;
char *dst = r_anal_esil_pop (esil);
if (dst && isregornum (esil, dst, &num)) {
ut8 buf[8];
ut64 *n64 = (ut64 *)&buf;
ret = esil_mem_read (esil, num, buf, sizeof (ut64));
snprintf (res, sizeof (res), "0x%"PFMT64x, *n64);
r_anal_esil_push (esil, res);
}
return ret;
}
static int esil_peek(RAnalEsil *esil) {
switch (esil->anal->bits) {
case 64: return esil_peek8 (esil);
case 32: return esil_peek4 (esil);
case 16: return esil_peek2 (esil);
case 8: return esil_peek1 (esil);
}
return 0;
}
typedef int RAnalEsilCmd(RAnalEsil *esil);
static int iscommand (RAnalEsil *esil, const char *word, RAnalEsilCmd **cmd) {
//TODO: use RCmd here?
if (!strcmp (word, "$")) { *cmd = &esil_syscall; return 1; } else
if (!strcmp (word, "==")) { *cmd = &esil_cmp; return 1; } else
if (!strcmp (word, "?=")) { *cmd = &esil_ifset; return 1; } else
if (!strcmp (word, "?{")) { *cmd = &esil_if; return 1; } else
//if (!strcmp (word, "!?{")) { *cmd = &esil_ask; return 1; } else
if (!strcmp (word, "<<")) { *cmd = &esil_lsl; return 1; } else
if (!strcmp (word, "<<=")) { *cmd = &esil_lsleq; return 1; } else
if (!strcmp (word, ">>")) { *cmd = &esil_lsr; return 1; } else
if (!strcmp (word, ">>=")) { *cmd = &esil_lsreq; return 1; } else
if (!strcmp (word, "&")) { *cmd = &esil_and; return 1; } else
if (!strcmp (word, "&=")) { *cmd = &esil_andeq; return 1; } else
if (!strcmp (word, "!")) { *cmd = &esil_neg; return 1; } else
if (!strcmp (word, "!=")){ *cmd = &esil_negeq; return 1; } else
if (!strcmp (word, "=")) { *cmd = &esil_eq; return 1; } else
if (!strcmp (word, "*")) { *cmd = &esil_mul; return 1; } else
if (!strcmp (word, "^")) { *cmd = &esil_xor; return 1; } else
if (!strcmp (word, "^=")) { *cmd = &esil_xoreq; return 1; } else
if (!strcmp (word, "+")) { *cmd = &esil_add; return 1; } else
if (!strcmp (word, "+=")) { *cmd = &esil_addeq; return 1; } else
if (!strcmp (word, "-")) { *cmd = &esil_sub; return 1; } else
if (!strcmp (word, "-=")) { *cmd = &esil_subeq; return 1; } else
if (!strcmp (word, "/")) { *cmd = &esil_div; return 1; } else
if (!strcmp (word, "=[1]")) { *cmd = &esil_poke1; return 1; } else
if (!strcmp (word, "=[4]")) { *cmd = &esil_poke4; return 1; } else
if (!strcmp (word, "=[8]")) { *cmd = &esil_poke8; return 1; } else
if (!strcmp (word, "[1]")) { *cmd = &esil_peek1; return 1; } else
if (!strcmp (word, "[4]")) { *cmd = &esil_peek4; return 1; } else
if (!strcmp (word, "[8]")) { *cmd = &esil_peek8; return 1; } else
if (!strcmp (word, "[]")) { *cmd = &esil_peek; return 1; } else {
}
return 0;
}
static int runword (RAnalEsil *esil, const char *word) {
RAnalEsilCmd *cmd = NULL;
if (esil->skip) {
if (!strcmp (word, "}"))
esil->skip = 0;
return 0;
} else {
if (!strcmp (word, "}{")) {
esil->skip = 1;
return 0;
}
}
if (iscommand (esil, word, &cmd)) {
// run action
if (cmd)
return cmd (esil);
}
// push value
r_anal_esil_push (esil, word);
return 0;
}
R_API int r_anal_esil_parse(RAnalEsil *esil, const char *str) {
int wordi = 0;
char word[64];
const char *ostr = str;
loop:
esil->repeat = 0;
wordi = 0;
str = ostr;
while (*str) {
if (wordi>62) {
eprintf ("Invalid esil string\n");
return -1;
}
if (*str == ';') {
word[wordi] = 0;
wordi = 0;
runword (esil, word);
if (esil->repeat)
goto loop;
return 0;
}
if (*str == ',') {
word[wordi] = 0;
wordi = 0;
runword (esil, word);
if (esil->repeat)
goto loop;
str++;
}
word[wordi++] = *str;
str++;
}
word[wordi-1] = 0;
runword (esil, word);
if (esil->repeat)
goto loop;
return 0;
}
R_API int r_anal_esil_register_cmd() {
// TODO: register new commands
return 0;
}