/*
* 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 Castao <castanyo@yahoo.es> and
* Roberto Ierusalimschy <roberto@inf.puc-rio.br>.
*/
#define OP_ZSTRING 'z' /* zero-terminated string */
#define OP_BSTRING 'p' /* string preceded by length byte */
#define OP_WSTRING 'P' /* string preceded by length word */
#define OP_SSTRING 'a' /* string preceded by length size_t */
#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_HEX 'H'
#include <ctype.h>
#include <string.h>
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
#include <stdint.h>
#include "pm3_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_optinteger(L, 3, 1) - 1;
//int i_read = (int)luaL_optint(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((int)(unsigned char) *f)) {
N = 0;
while (isdigit((int)(unsigned char) *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, uint8_t)
UNPACKSTRING(OP_WSTRING, uint16_t)
UNPACKSTRING(OP_SSTRING, uint32_t)
UNPACKNUMBER(OP_NUMBER, lua_Number)
UNPACKNUMBER(OP_DOUBLE, double)
UNPACKNUMBER(OP_FLOAT, float)
UNPACKNUMBER(OP_CHAR, int8_t)
UNPACKNUMBER(OP_BYTE, uint8_t)
UNPACKNUMBER(OP_SHORT, int16_t)
UNPACKNUMBER(OP_USHORT, uint16_t)
UNPACKNUMBER(OP_INT, int32_t)
UNPACKNUMBER(OP_UINT, uint32_t)
UNPACKNUMBER(OP_LONG, int64_t)
UNPACKNUMBER(OP_ULONG, uint64_t)
case OP_HEX: {
luaL_Buffer buf;
char hdigit = '0';
luaL_buffinit(L, &buf);
N++;
if (i + N > len) {done = 1; break;}
for (unsigned int ii = i; ii < i + N; ii++) {
int 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 ' ':
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((int)(unsigned char) *f)) {
N = 0;
while (isdigit((int)(unsigned char) *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, uint8_t)
PACKSTRING(OP_WSTRING, uint16_t)
PACKSTRING(OP_SSTRING, uint32_t)
PACKNUMBER(OP_NUMBER, lua_Number)
PACKNUMBER(OP_DOUBLE, double)
PACKNUMBER(OP_FLOAT, float)
PACKNUMBER(OP_CHAR, int8_t)
PACKNUMBER(OP_BYTE, uint8_t)
PACKNUMBER(OP_SHORT, int16_t)
PACKNUMBER(OP_USHORT, uint16_t)
PACKNUMBER(OP_INT, int32_t)
PACKNUMBER(OP_UINT, uint32_t)
PACKNUMBER(OP_LONG, int64_t)
PACKNUMBER(OP_ULONG, uint64_t)
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((int)(unsigned char) a[ii])) {
if (isdigit((int)(unsigned char) 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}
};
LUALIB_API int luaopen_binlib(lua_State *L) {
luaL_newlib(L, binlib);
return 1;
}
/*
** Open bin library
*/
int set_bin_library(lua_State *L) {
luaL_requiref(L, "bin", luaopen_binlib, 1);
lua_pop(L, 1);
return 1;
}