/*
* -- nse_packlib.cc
* -- adapted from:
* lpack.c
* a Lua library for packing and unpacking binary data
* Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>
* 29 Jun 2007 19:27:20
* This code is hereby placed in the public domain.
* with contributions from Ignacio Castaño <castanyo@yahoo.es> and
* Roberto Ierusalimschy <roberto@inf.puc-rio.br>.
* -- modified:
* BinStringHandling
*/
#define OP_ZSTRING 'z' /* zero-terminated string */
#define OP_BSTRING 'p' /* string preceded by 1 byte integer */
#define OP_WSTRING 'P' /* string preceded by 2 byte integer */
#define OP_SSTRING 'a' /* string preceded by 4 byte integer */
#define OP_STRING 'A' /* string */
#define OP_FLOAT 'f' /* float */
#define OP_DOUBLE 'd' /* double */
#define OP_NUMBER 'n' /* Lua number */
#define OP_CHAR 'c' /* char (1-byte int) */
#define OP_BYTE 'C' /* byte = unsigned char (1-byte unsigned int) */
#define OP_SHORT 's' /* short (2-byte int) */
#define OP_USHORT 'S' /* unsigned short (2-byte unsigned int) */
#define OP_INT 'i' /* int (4-byte int) */
#define OP_UINT 'I' /* unsigned int (4-byte unsigned int) */
#define OP_LONG 'l' /* long (8-byte int) */
#define OP_ULONG 'L' /* unsigned long (8-byte unsigned int) */
#define OP_LITTLEENDIAN '<' /* little endian */
#define OP_BIGENDIAN '>' /* big endian */
#define OP_NATIVE '=' /* native endian */
#define OP_BINMSB 'B'
#define OP_HEX 'H'
#define OP_NULL 'x'
#include <ctype.h>
#include <string.h>
#include <nbase.h>
extern "C" {
#include "lua.h"
#include "lauxlib.h"
}
#include "nse_binlib.h"
static void badcode(lua_State *L, int c)
{
char s[]="bad code `?'";
s[sizeof(s)-3]=c;
luaL_argerror(L,1,s);
}
static int doendian(int c)
{
int x=1;
int e=*(char*)&x;
if (c==OP_LITTLEENDIAN) return !e;
if (c==OP_BIGENDIAN) return e;
if (c==OP_NATIVE) return 0;
return 0;
}
static void doswap(int swap, void *p, size_t n)
{
if (swap)
{
char *a=(char*)p;
int i,j;
for (i=0, j=n-1, n=n/2; n--; i++, j--)
{
char t=a[i]; a[i]=a[j]; a[j]=t;
}
}
}
#define UNPACKNUMBER(OP,T) \
case OP: \
{ \
T a; \
int m=sizeof(a); \
if (i+m>len) { done = 1; break;} \
memcpy(&a,s+i,m); \
i+=m; \
doswap(swap,&a,m); \
lua_pushnumber(L,(lua_Number)a); \
++n; \
break; \
}
#define UNPACKSTRING(OP,T) \
case OP: \
{ \
T l; \
int m=sizeof(l); \
if (i+m>len) { done = 1; break; } \
memcpy(&l,s+i,m); \
doswap(swap,&l,m); \
if (i+m+l>len) { done = 1; break;} \
i+=m; \
lua_pushlstring(L,s+i,l); \
i+=l; \
++n; \
break; \
}
#define HEXDIGITS(DIG) \
"0123456789ABCDEF"[DIG]
static int l_unpack(lua_State *L) /** unpack(f,s, [init]) */
{
size_t len;
const char *s=luaL_checklstring(L,2,&len); /* switched s and f */
const char *f=luaL_checkstring(L,1);
int i_read = luaL_optnumber(L,3,1)-1;
unsigned int i;
if (i_read >= 0) {
i = i_read;
} else {
i = 0;
}
int n=0;
int swap=0;
int done=0;
lua_pushnil(L);
while (*f && done == 0)
{
int c=*f++;
int N=1;
if (isdigit(*f))
{
N=0;
while (isdigit(*f)) N=10*N+(*f++)-'0';
if (N==0 && c==OP_STRING) { lua_pushliteral(L,""); ++n; }
}
while (N-- && done == 0) switch (c)
{
case OP_LITTLEENDIAN:
case OP_BIGENDIAN:
case OP_NATIVE:
{
swap=doendian(c);
N=0;
break;
}
case OP_STRING:
{
++N;
if (i+N>len) {done = 1; break; }
lua_pushlstring(L,s+i,N);
i+=N;
++n;
N=0;
break;
}
case OP_ZSTRING:
{
size_t l;
if (i>=len) {done = 1; break; }
l=strlen(s+i);
lua_pushlstring(L,s+i,l);
i+=l+1;
++n;
break;
}
UNPACKSTRING(OP_BSTRING, u8)
UNPACKSTRING(OP_WSTRING, u16)
UNPACKSTRING(OP_SSTRING, u32)
UNPACKNUMBER(OP_NUMBER, lua_Number)
UNPACKNUMBER(OP_DOUBLE, double)
UNPACKNUMBER(OP_FLOAT, float)
UNPACKNUMBER(OP_CHAR, s8)
UNPACKNUMBER(OP_BYTE, u8)
UNPACKNUMBER(OP_SHORT, s16)
UNPACKNUMBER(OP_USHORT, u16)
UNPACKNUMBER(OP_INT, s32)
UNPACKNUMBER(OP_UINT, u32)
UNPACKNUMBER(OP_LONG, s64)
UNPACKNUMBER(OP_ULONG, u64)
case OP_BINMSB:
{
luaL_Buffer buf;
luaL_buffinit(L,&buf);
unsigned char sbyte = 0x80;
N++;
if (i+N > len) {done = 1; break;}
for (unsigned int ii = i; ii < i+N; ii++) {
sbyte = 0x80;
for (int ij = 0; ij < 8; ij++) {
if (s[ii] & sbyte) {
luaL_addlstring(&buf, "1", 1);
} else {
luaL_addlstring(&buf, "0", 1);
}
sbyte = sbyte >> 1;
}
}
luaL_pushresult(&buf);
n++;
i += N;
N = 0;
break;
}
case OP_HEX:
{
luaL_Buffer buf;
char hdigit = '0';
int val = 0;
luaL_buffinit(L,&buf);
N++;
if (i+N > len) {done = 1; break;}
for (unsigned int ii = i; ii < i+N; ii++) {
val = s[ii] & 0xF0;
val = val >> 4;
hdigit = HEXDIGITS(val);
luaL_addlstring(&buf, &hdigit, 1);
val = s[ii] & 0x0F;
hdigit = HEXDIGITS(val);
luaL_addlstring(&buf, &hdigit, 1);
}
luaL_pushresult(&buf);
n++;
i += N;
N = 0;
break;
}
case OP_NULL:
{
i+= N + 1;
N = 0;
break;
}
case ' ': case ',':
break;
default:
badcode(L,c);
break;
}
}
lua_pushnumber(L,i+1);
lua_replace(L,-n-2);
return n+1;
}
#define PACKNUMBER(OP,T) \
case OP: \
{ \
T a=(T)luaL_checknumber(L,i++); \
doswap(swap,&a,sizeof(a)); \
luaL_addlstring(&b,(char*)&a,sizeof(a)); \
break; \
}
#define PACKSTRING(OP,T) \
case OP: \
{ \
size_t l; \
const char *a=luaL_checklstring(L,i++,&l); \
T ll=(T)l; \
doswap(swap,&ll,sizeof(ll)); \
luaL_addlstring(&b,(char*)&ll,sizeof(ll)); \
luaL_addlstring(&b,a,l); \
break; \
}
static int l_pack(lua_State *L) /** pack(f,...) */
{
int i=2;
const char *f=luaL_checkstring(L,1);
int swap=0;
luaL_Buffer b;
luaL_buffinit(L,&b);
while (*f)
{
int c=*f++;
int N=1;
if (isdigit(*f))
{
N=0;
while (isdigit(*f)) N=10*N+(*f++)-'0';
}
while (N--) switch (c)
{
case OP_LITTLEENDIAN:
case OP_BIGENDIAN:
case OP_NATIVE:
{
swap=doendian(c);
N=0;
break;
}
case OP_STRING:
case OP_ZSTRING:
{
size_t l;
const char *a=luaL_checklstring(L,i++,&l);
luaL_addlstring(&b,a,l+(c==OP_ZSTRING));
break;
}
PACKSTRING(OP_BSTRING, u8)
PACKSTRING(OP_WSTRING, u16)
PACKSTRING(OP_SSTRING, u32)
PACKNUMBER(OP_NUMBER, lua_Number)
PACKNUMBER(OP_DOUBLE, double)
PACKNUMBER(OP_FLOAT, float)
PACKNUMBER(OP_CHAR, s8)
PACKNUMBER(OP_BYTE, u8)
PACKNUMBER(OP_SHORT, s16)
PACKNUMBER(OP_USHORT, u16)
PACKNUMBER(OP_INT, s32)
PACKNUMBER(OP_UINT, u32)
PACKNUMBER(OP_LONG, s64)
PACKNUMBER(OP_ULONG, u64)
case OP_BINMSB:
{
unsigned char sbyte = 0;
size_t l;
unsigned int ii = 0, ia = 0;
const char *a = luaL_checklstring(L, i++, &l);
for (ia = 0; ia < l; ia+= 8) {
sbyte = 0;
for (ii = 0; ii+ia < l && ii < 8; ii++) {
sbyte = sbyte << 1;
if (a[ii+ia] != '0') {
sbyte++;
}
}
for (; ii < 8; ii++) {
sbyte = sbyte << 1;
}
luaL_addlstring(&b, (char *) &sbyte, 1);
}
break;
}
case OP_NULL:
{
char nullbyte = 0;
luaL_addlstring(&b, &nullbyte, 1);
break;
}
case OP_HEX:
{ // doing digit parsing the lpack way
unsigned char sbyte = 0;
size_t l;
unsigned int ii = 0;
int odd = 0;
const char *a = luaL_checklstring(L, i++, &l);
for (ii = 0; ii < l; ii++) {
if (isxdigit(a[ii])) {
if (isdigit(a[ii])) {
sbyte += a[ii] - '0';
odd++;
} else if (a[ii] >= 'A' && a[ii] <= 'F') {
sbyte += a[ii] - 'A' + 10;
odd++;
} else if (a[ii] >= 'a' && a[ii] <= 'f') {
sbyte += a[ii] - 'a' + 10;
odd++;
}
if (odd == 1) {
sbyte = sbyte << 4;
} else if (odd == 2) {
luaL_addlstring(&b, (char *) &sbyte, 1);
sbyte = 0;
odd = 0;
}
} else if (isspace(a[ii])) {
/* ignore */
} else {
/* err ... ignore too*/
}
}
if (odd == 1) {
luaL_addlstring(&b, (char *) &sbyte, 1);
}
break;
}
case ' ': case ',':
break;
default:
badcode(L,c);
break;
}
}
luaL_pushresult(&b);
return 1;
}
static const luaL_reg binlib[] =
{
{"pack", l_pack},
{"unpack", l_unpack},
{NULL, NULL}
};
/*
** Open bin library
*/
LUALIB_API int luaopen_binlib (lua_State *L) {
luaL_register(L, NSE_BINLIBNAME, binlib);
return 1;
}