/* * lpack.c * a Lua library for packing and unpacking binary data * Luiz Henrique de Figueiredo * 29 Jun 2007 19:27:20 * This code is hereby placed in the public domain. * with contributions from Ignacio Castao and * Roberto Ierusalimschy . */ #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 #include #include #include #include #include #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 = 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'; 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 ' ': 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((unsigned char)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; }