e7ab7a907c
Change-Id: I8f6693108c43959e54911d35b4fbf730c59add60 Reviewed-on: https://code.wireshark.org/review/26361 Reviewed-by: Anders Broman <a.broman58@gmail.com>
672 lines
23 KiB
C
672 lines
23 KiB
C
/******************************************************************************
|
|
* Copyright (C) 2010-2012 Lua.org, PUC-Rio. All rights reserved.
|
|
*
|
|
* SPDX-License-Identifier: MIT
|
|
*
|
|
******************************************************************************/
|
|
/*
|
|
** {======================================================
|
|
** Library for packing/unpacking structures.
|
|
** See Copyright Notice above.
|
|
**
|
|
** Small changes were made by Hadriel Kaplan - those changes
|
|
** are in the Public Domain.
|
|
**
|
|
** Some changes are based on a patch to struct.h from
|
|
** Flemming Madsen, from here:
|
|
** http://lua-users.org/lists/lua-l/2009-10/msg00572.html
|
|
** In particular, these changes from him:
|
|
** -Can handle 'long long' integers (i8 / I8); though they're converted to doubles
|
|
** -Can insert/specify padding anywhere in a struct. ('X' eg. when a string is following a union)
|
|
** -Can report current offset in both pack and unpack ('=')
|
|
** -Can mask out return values when you only want to calculate sizes or unmarshal pascal-style strings. '(' & ')'
|
|
**
|
|
** Changes I made:
|
|
** -Added support for Int64/UInt64 being packed/unpacked, using 'e'/'E'
|
|
** -Made it follow Wireshark's conventions so we could get API docs
|
|
** =======================================================
|
|
*/
|
|
/*
|
|
** Valid formats:
|
|
** > - big endian
|
|
** < - little endian
|
|
** ![num] - alignment
|
|
** x[num] - pad num bytes, default 1
|
|
** X[num] - pad to num align, default MAXALIGN
|
|
**
|
|
** Following are system-dependent sizes:
|
|
** i/I - signed/unsigned int
|
|
** l/L - signed/unsigned long
|
|
** f - float
|
|
** T - size_t
|
|
**
|
|
** Following are system-independent sizes:
|
|
** b/B - signed/unsigned byte
|
|
** h/H - signed/unsigned short
|
|
** in/In - signed/unsigned integer of size `n' bytes
|
|
Note: Unpack of i/I is done to a Lua_number, typically a double,
|
|
so unpacking a 64-bit field (i8/I8) will lose precision.
|
|
Use e/E to unpack into a Wireshark Int64/UInt64 object/userdata instead.
|
|
** e/E - signed/unsigned eight-byte Integer (64bits, long long), to/from Int64/UInt64 object
|
|
** d - double
|
|
** cn - sequence of `n' chars (from/to a string); when packing, n==0 means
|
|
the whole string; when unpacking, n==0 means use the previous
|
|
read number as the string length
|
|
** s - zero-terminated string
|
|
** ' ' - ignored
|
|
** '(' ')' - stop assigning items. ')' start assigning (padding when packing)
|
|
** '=' - return current position / offset
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <assert.h>
|
|
#include <limits.h>
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
#include "wslua.h"
|
|
|
|
/* WSLUA_MODULE Struct Binary encode/decode support
|
|
|
|
The Struct class offers basic facilities to convert Lua values to and from C-style structs
|
|
in binary Lua strings. This is based on Roberto Ierusalimschy's Lua struct library found
|
|
in http://www.inf.puc-rio.br/~roberto/struct/, with some minor modifications as follows:
|
|
* Added support for `Int64`/`UInt64` being packed/unpacked, using 'e'/'E'.
|
|
* Can handle 'long long' integers (i8 / I8); though they're converted to doubles.
|
|
* Can insert/specify padding anywhere in a struct. ('X' eg. when a string is following a union).
|
|
* Can report current offset in both `pack` and `unpack` ('`=`').
|
|
* Can mask out return values when you only want to calculate sizes or unmarshal
|
|
pascal-style strings using '`(`' & '`)`'.
|
|
|
|
All but the first of those changes are based on an email from Flemming Madsen, on the lua-users
|
|
mailing list, which can be found http://lua-users.org/lists/lua-l/2009-10/msg00572.html[here].
|
|
|
|
The main functions are `Struct.pack`, which packs multiple Lua values into a struct-like
|
|
Lua binary string; and `Struct.unpack`, which unpacks multiple Lua values from a given
|
|
struct-like Lua binary string. There are some additional helper functions available as well.
|
|
|
|
All functions in the Struct library are called as static member functions, not object methods,
|
|
so they are invoked as "Struct.pack(...)" instead of "object:pack(...)".
|
|
|
|
The fist argument to several of the `Struct` functions is a format string, which describes
|
|
the layout of the structure. The format string is a sequence of conversion elements, which
|
|
respect the current endianness and the current alignment requirements. Initially, the
|
|
current endianness is the machine's native endianness and the current alignment requirement
|
|
is 1 (meaning no alignment at all). You can change these settings with appropriate directives
|
|
in the format string.
|
|
|
|
The supported elements in the format string are as follows:
|
|
|
|
* `$$ $$' (empty space) ignored.
|
|
* `++!++__n__' flag to set the current alignment requirement to 'n' (necessarily a power of 2);
|
|
an absent 'n' means the machine's native alignment.
|
|
* `++>++' flag to set mode to big endian (i.e., network-order).
|
|
* `++<++' flag to set mode to little endian.
|
|
* `++x++' a padding zero byte with no corresponding Lua value.
|
|
* `++b++' a signed char.
|
|
* `++B++' an unsigned char.
|
|
* `++h++' a signed short (native size).
|
|
* `++H++' an unsigned short (native size).
|
|
* `++l++' a signed long (native size).
|
|
* `++L++' an unsigned long (native size).
|
|
* `++T++' a size_t (native size).
|
|
* `++i++__n__' a signed integer with 'n' bytes. An absent 'n' means the native size of an int.
|
|
* `++I++__n__' like `++i++__n__' but unsigned.
|
|
* `++e++' signed 8-byte Integer (64-bits, long long), to/from a +Int64+ object.
|
|
* `++E++' unsigned 8-byte Integer (64-bits, long long), to/from a +UInt64+ object.
|
|
* `++f++' a float (native size).
|
|
* `++d++' a double (native size).
|
|
* `++s++' a zero-terminated string.
|
|
* `++c++__n__' a sequence of exactly 'n' chars corresponding to a single Lua string. An absent 'n'
|
|
means 1. When packing, the given string must have at least 'n' characters (extra
|
|
characters are discarded).
|
|
* `++c0++' this is like `++c++__n__', except that the 'n' is given by other means: When packing, 'n' is
|
|
the length of the given string; when unpacking, 'n' is the value of the previous unpacked
|
|
value (which must be a number). In that case, this previous value is not returned.
|
|
* `++x++__n__' pad to 'n' number of bytes, default 1.
|
|
* `++X++__n__' pad to 'n' alignment, default MAXALIGN.
|
|
* `++(++' to stop assigning items, and `++)++' start assigning (padding when packing).
|
|
* `++=++' to return the current position / offset.
|
|
|
|
[NOTE]
|
|
====
|
|
Using `i`, `I`, `h`, `H`, `l`, `L`, `f`, and `T` is strongly discouraged, as those sizes
|
|
are system-dependent. Use the explicitly sized variants instead, such as `i4` or `E`.
|
|
|
|
Unpacking of `i`/`I` is done to a Lua number, a double-precision floating point,
|
|
so unpacking a 64-bit field (`i8`/`I8`) will lose precision.
|
|
Use `e`/`E` to unpack into a Wireshark `Int64`/`UInt64` object instead.
|
|
====
|
|
|
|
@since 1.11.3
|
|
*/
|
|
|
|
|
|
/* The following line is here so that make-reg.pl does the right thing. This 'Struct' class
|
|
isn't really a class, so it doesn't have the checkStruct/pushStruct/etc. functions
|
|
the following macro would generate; but it does need to be registered and such, so...
|
|
WSLUA_CLASS_DEFINE_BASE(Struct,NOP,0);
|
|
*/
|
|
|
|
/* basic integer type - yes this is system-specific size - it's meant to be */
|
|
#if !defined(STRUCT_INT)
|
|
#define STRUCT_INT long
|
|
#endif
|
|
|
|
typedef STRUCT_INT Inttype;
|
|
|
|
/* corresponding unsigned version */
|
|
typedef unsigned STRUCT_INT Uinttype;
|
|
|
|
/* maximum size (in bytes) for integral types */
|
|
#define MAXINTSIZE 32
|
|
|
|
/* is 'x' a power of 2? */
|
|
#define isp2(x) ((x) > 0 && ((x) & ((x) - 1)) == 0)
|
|
|
|
/* dummy structure to get padding/alignment requirements */
|
|
struct cD {
|
|
gchar c;
|
|
gdouble d;
|
|
};
|
|
|
|
|
|
#define PADDING (sizeof(struct cD) - sizeof(gdouble))
|
|
#define MAXALIGN (PADDING > sizeof(int) ? PADDING : sizeof(int))
|
|
|
|
|
|
/* endian options */
|
|
#define BIG 0
|
|
#define LITTLE 1
|
|
|
|
/* trick to determine native endianness of system */
|
|
static union {
|
|
int dummy;
|
|
gchar endian;
|
|
} const native = {1};
|
|
|
|
/* settings info */
|
|
typedef struct Header {
|
|
int endian;
|
|
int align;
|
|
gboolean noassign;
|
|
} Header;
|
|
|
|
/* For options that take a number argument, gets the number */
|
|
static int getnum (const gchar **fmt, int df) {
|
|
if (!g_ascii_isdigit(**fmt)) /* no number? */
|
|
return df; /* return default value */
|
|
else {
|
|
int a = 0;
|
|
do {
|
|
a = a*10 + *((*fmt)++) - '0';
|
|
} while (g_ascii_isdigit(**fmt));
|
|
return a;
|
|
}
|
|
}
|
|
|
|
|
|
#define defaultoptions(h) ((h)->endian = native.endian, (h)->align = 1, (h)->noassign = FALSE)
|
|
|
|
|
|
/* gets size (number of bytes) for a given type */
|
|
static size_t optsize (lua_State *L, gchar opt, const gchar **fmt) {
|
|
switch (opt) {
|
|
case 'B': case 'b': return sizeof(gchar);
|
|
case 'H': case 'h': return sizeof(gshort);
|
|
case 'L': case 'l': return sizeof(glong);
|
|
case 'E': case 'e': return sizeof(gint64);
|
|
case 'T': return sizeof(size_t);
|
|
case 'f': return sizeof(gfloat);
|
|
case 'd': return sizeof(gdouble);
|
|
case 'x': return getnum(fmt, 1);
|
|
case 'X': return getnum(fmt, MAXALIGN);
|
|
case 'c': return getnum(fmt, 1);
|
|
case 'i': case 'I': {
|
|
int sz = getnum(fmt, sizeof(int));
|
|
if (sz > MAXINTSIZE)
|
|
luaL_error(L, "integral size %d is larger than limit of %d",
|
|
sz, MAXINTSIZE);
|
|
return sz;
|
|
}
|
|
case 's': case ' ':
|
|
case '<': case '>':
|
|
case '(': case ')':
|
|
case '!': case '=':
|
|
return 0; /* these cases do not have a size */
|
|
default: {
|
|
const gchar *msg = lua_pushfstring(L, "invalid format option [%c]", opt);
|
|
return luaL_argerror(L, 1, msg);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
** return number of bytes needed to align an element of size 'size'
|
|
** at current position 'len'
|
|
*/
|
|
static int gettoalign (size_t len, Header *h, int opt, size_t size) {
|
|
if (size == 0 || opt == 'c' || opt == 's') return 0;
|
|
if (size > (size_t)h->align)
|
|
size = h->align; /* respect max. alignment */
|
|
return (int)((size - (len & (size - 1))) & (size - 1));
|
|
}
|
|
|
|
|
|
/*
|
|
** options to control endianness and alignment settings
|
|
*/
|
|
static void controloptions (lua_State *L, int opt, const gchar **fmt,
|
|
Header *h) {
|
|
switch (opt) {
|
|
case ' ': return; /* ignore white spaces */
|
|
case '>': h->endian = BIG; return;
|
|
case '<': h->endian = LITTLE; return;
|
|
case '(': h->noassign = TRUE; return;
|
|
case ')': h->noassign = FALSE; return;
|
|
case '!': {
|
|
int a = getnum(fmt, MAXALIGN);
|
|
if (!isp2(a))
|
|
luaL_error(L, "alignment %d is not a power of 2", a);
|
|
h->align = a;
|
|
return;
|
|
}
|
|
default: {
|
|
const char *msg = lua_pushfstring(L, "invalid format option '%c'", opt);
|
|
luaL_argerror(L, 1, msg);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Encodes a Lua number as an integer of given size and endianness into a string struct */
|
|
static void putinteger (lua_State *L, luaL_Buffer *b, int arg, int endian,
|
|
int size) {
|
|
lua_Number n = luaL_checknumber(L, arg);
|
|
/* this one's not system dependent size - it's a long long */
|
|
gint64 value;
|
|
gchar buff[MAXINTSIZE];
|
|
if (n < 0)
|
|
value = (guint64)(gint64)n;
|
|
else
|
|
value = (guint64)n;
|
|
if (endian == LITTLE) {
|
|
int i;
|
|
for (i = 0; i < size; i++) {
|
|
buff[i] = (value & 0xff);
|
|
value >>= 8;
|
|
}
|
|
}
|
|
else {
|
|
int i;
|
|
for (i = size - 1; i >= 0; i--) {
|
|
buff[i] = (value & 0xff);
|
|
value >>= 8;
|
|
}
|
|
}
|
|
luaL_addlstring(b, buff, size);
|
|
}
|
|
|
|
/* corrects endianness - usually done by other functions themselves, but is
|
|
* used for float/doubles, since on some platforms they're endian'ed as well
|
|
*/
|
|
static void correctbytes (gchar *b, int size, int endian) {
|
|
if (endian != native.endian) {
|
|
int i = 0;
|
|
while (i < --size) {
|
|
gchar temp = b[i];
|
|
b[i++] = b[size];
|
|
b[size] = temp;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
WSLUA_CONSTRUCTOR Struct_pack (lua_State *L) {
|
|
/* Returns a string containing the values arg1, arg2, etc. packed/encoded according to the format string. */
|
|
#define WSLUA_ARG_Struct_pack_FORMAT 1 /* The format string */
|
|
#define WSLUA_ARG_Struct_pack_VALUE 2 /* One or more Lua value(s) to encode, based on the given format. */
|
|
luaL_Buffer b;
|
|
const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_pack_FORMAT);
|
|
Header h;
|
|
int poscnt = 0;
|
|
int posBuf[10];
|
|
int arg = 2;
|
|
size_t totalsize = 0;
|
|
defaultoptions(&h);
|
|
lua_pushnil(L); /* mark to separate arguments from string buffer */
|
|
luaL_buffinit(L, &b);
|
|
while (*fmt != '\0') {
|
|
int opt = *fmt++;
|
|
size_t size = optsize(L, opt, &fmt);
|
|
int toalign = gettoalign(totalsize, &h, opt, size);
|
|
totalsize += toalign;
|
|
while (toalign-- > 0) luaL_addchar(&b, '\0');
|
|
if (opt == 'X') size = 0; /* 'X' is about alignment, not size */
|
|
if (h.noassign && size) opt = 'x'; /* for pack, "(i4)" is the same as "x4" */
|
|
switch (opt) {
|
|
case 'b': case 'B': case 'h': case 'H':
|
|
case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */
|
|
putinteger(L, &b, arg++, h.endian, (int)size);
|
|
break;
|
|
}
|
|
case 'e': {
|
|
Int64_pack(L, &b, arg++, h.endian == LITTLE);
|
|
break;
|
|
}
|
|
case 'E': {
|
|
UInt64_pack(L, &b, arg++, h.endian == LITTLE);
|
|
break;
|
|
}
|
|
case 'x': case 'X': {
|
|
size_t len = size;
|
|
while (len-- > 0)
|
|
luaL_addchar(&b, '\0');
|
|
break;
|
|
}
|
|
case 'f': {
|
|
gfloat f = (gfloat)luaL_checknumber(L, arg++);
|
|
correctbytes((gchar *)&f, (int)size, h.endian);
|
|
luaL_addlstring(&b, (gchar *)&f, size);
|
|
break;
|
|
}
|
|
case 'd': {
|
|
gdouble d = luaL_checknumber(L, arg++);
|
|
correctbytes((gchar *)&d, (int)size, h.endian);
|
|
luaL_addlstring(&b, (gchar *)&d, size);
|
|
break;
|
|
}
|
|
case 'c': case 's': {
|
|
size_t l;
|
|
const gchar *s = luaL_checklstring(L, arg++, &l);
|
|
if (size == 0) size = l;
|
|
luaL_argcheck(L, l >= (size_t)size, arg, "string too short");
|
|
luaL_addlstring(&b, s, size);
|
|
if (opt == 's') {
|
|
luaL_addchar(&b, '\0'); /* add zero at the end */
|
|
size++;
|
|
}
|
|
break;
|
|
}
|
|
case '=': {
|
|
if (poscnt < (int)(sizeof(posBuf)/sizeof(posBuf[0])))
|
|
posBuf[poscnt++] = (int)totalsize + 1;
|
|
break;
|
|
}
|
|
default: controloptions(L, opt, &fmt, &h);
|
|
}
|
|
totalsize += size;
|
|
}
|
|
luaL_pushresult(&b);
|
|
for (arg = 0; arg < poscnt; arg++)
|
|
lua_pushinteger(L, posBuf[arg]);
|
|
WSLUA_RETURN(poscnt + 1); /* The packed binary Lua string, plus any positions due to '=' being used in format. */
|
|
}
|
|
|
|
/* Decodes an integer from a string struct into a Lua number, based on
|
|
* given endianness and size. If the integer type is signed, this makes
|
|
* the Lua number be +/- correctly as well.
|
|
*/
|
|
static lua_Number getinteger (const gchar *buff, int endian,
|
|
int issigned, int size) {
|
|
Uinttype l = 0;
|
|
int i;
|
|
if (endian == BIG) {
|
|
for (i = 0; i < size; i++) {
|
|
l <<= 8;
|
|
l |= (Uinttype)(guchar)buff[i];
|
|
}
|
|
}
|
|
else {
|
|
for (i = size - 1; i >= 0; i--) {
|
|
l <<= 8;
|
|
l |= (Uinttype)(guchar)buff[i];
|
|
}
|
|
}
|
|
if (!issigned)
|
|
return (lua_Number)l;
|
|
else { /* signed format */
|
|
Uinttype mask = (Uinttype)(~((Uinttype)0)) << (size*8 - 1);
|
|
if (l & mask) /* negative value? */
|
|
l |= mask; /* signal extension */
|
|
return (lua_Number)(Inttype)l;
|
|
}
|
|
}
|
|
|
|
#define b_pushnumber(n) { if (!h.noassign) lua_pushnumber(L, (lua_Number)(n)); }
|
|
|
|
WSLUA_CONSTRUCTOR Struct_unpack (lua_State *L) {
|
|
/* Unpacks/decodes multiple Lua values from a given struct-like binary Lua string.
|
|
The number of returned values depends on the format given, plus an additional value of the position where it stopped reading is returned. */
|
|
#define WSLUA_ARG_Struct_unpack_FORMAT 1 /* The format string */
|
|
#define WSLUA_ARG_Struct_unpack_STRUCT 2 /* The binary Lua string to unpack */
|
|
#define WSLUA_OPTARG_Struct_unpack_BEGIN 3 /* The position to begin reading from (default=1) */
|
|
Header h;
|
|
const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_unpack_FORMAT);
|
|
size_t ld;
|
|
const char *data = wslua_checklstring_only(L, WSLUA_ARG_Struct_unpack_STRUCT, &ld);
|
|
size_t pos = luaL_optinteger(L, WSLUA_OPTARG_Struct_unpack_BEGIN, 1) - 1;
|
|
defaultoptions(&h);
|
|
lua_settop(L, 2);
|
|
while (*fmt) {
|
|
int opt = *fmt++;
|
|
size_t size = optsize(L, opt, &fmt);
|
|
pos += gettoalign(pos, &h, opt, size);
|
|
luaL_argcheck(L, pos+size <= ld, 2, "data string too short");
|
|
|
|
if (opt == 'X') size = 0;
|
|
if (h.noassign && size > 0) {
|
|
/* if we're not assigning, and the opt type has a size, then loop again */
|
|
/* this will not be the case for control options, 'c0', 's', and '=' */
|
|
pos += size;
|
|
continue;
|
|
}
|
|
|
|
luaL_checkstack(L, 1, "too many results");
|
|
switch (opt) {
|
|
case 'b': case 'B': case 'h': case 'H':
|
|
case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */
|
|
int issigned = g_ascii_islower(opt);
|
|
lua_Number res = getinteger(data+pos, h.endian, issigned, (int)size);
|
|
lua_pushnumber(L, res);
|
|
break;
|
|
}
|
|
case 'e': {
|
|
Int64_unpack(L, data+pos, h.endian == LITTLE);
|
|
break;
|
|
}
|
|
case 'E': {
|
|
UInt64_unpack(L, data+pos, h.endian == LITTLE);
|
|
break;
|
|
}
|
|
case 'x': case 'X': {
|
|
break;
|
|
}
|
|
case 'f': {
|
|
gfloat f;
|
|
memcpy(&f, data+pos, size);
|
|
correctbytes((gchar *)&f, sizeof(f), h.endian);
|
|
lua_pushnumber(L, f);
|
|
break;
|
|
}
|
|
case 'd': {
|
|
gdouble d;
|
|
memcpy(&d, data+pos, size);
|
|
correctbytes((gchar *)&d, sizeof(d), h.endian);
|
|
lua_pushnumber(L, d);
|
|
break;
|
|
}
|
|
case 'c': {
|
|
if (size == 0) {
|
|
if (!lua_isnumber(L, -1))
|
|
luaL_error(L, "format `c0' needs a previous size");
|
|
size = wslua_toguint32(L, -1);
|
|
lua_pop(L, 1);
|
|
luaL_argcheck(L, pos+size <= ld, 2, "data string too short");
|
|
}
|
|
if (!h.noassign)
|
|
lua_pushlstring(L, data+pos, size);
|
|
break;
|
|
}
|
|
case 's': {
|
|
const gchar *e = (const char *)memchr(data+pos, '\0', ld - pos);
|
|
if (e == NULL)
|
|
luaL_error(L, "unfinished string in data");
|
|
size = (e - (data+pos)) + 1;
|
|
if (!h.noassign)
|
|
lua_pushlstring(L, data+pos, size - 1);
|
|
break;
|
|
}
|
|
case '=': {
|
|
lua_pushinteger(L, pos + 1);
|
|
break;
|
|
}
|
|
default: controloptions(L, opt, &fmt, &h);
|
|
}
|
|
pos += size;
|
|
}
|
|
lua_pushinteger(L, pos + 1);
|
|
WSLUA_RETURN(lua_gettop(L) - 2); /* One or more values based on format, plus the position it stopped unpacking. */
|
|
}
|
|
|
|
|
|
WSLUA_CONSTRUCTOR Struct_size (lua_State *L) {
|
|
/* Returns the length of a binary string that would be consumed/handled by the given format string. */
|
|
#define WSLUA_ARG_Struct_size_FORMAT 1 /* The format string */
|
|
Header h;
|
|
const gchar *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_size_FORMAT);
|
|
size_t pos = 0;
|
|
defaultoptions(&h);
|
|
while (*fmt) {
|
|
int opt = *fmt++;
|
|
size_t size = optsize(L, opt, &fmt);
|
|
pos += gettoalign(pos, &h, opt, size);
|
|
if (opt == 's')
|
|
luaL_argerror(L, 1, "option 's' has no fixed size");
|
|
else if (opt == 'c' && size == 0)
|
|
luaL_argerror(L, 1, "option 'c0' has no fixed size");
|
|
if (!g_ascii_isalnum(opt))
|
|
controloptions(L, opt, &fmt, &h);
|
|
pos += size;
|
|
}
|
|
lua_pushinteger(L, pos);
|
|
WSLUA_RETURN(1); /* The size number */
|
|
}
|
|
|
|
WSLUA_CONSTRUCTOR Struct_values (lua_State *L) {
|
|
/* Returns the number of Lua values contained in the given format string.
|
|
This will be the number of returned values from a call to Struct.unpack()
|
|
not including the extra return value of offset position. (i.e., Struct.values()
|
|
does not count that extra return value) This will also be the number of
|
|
arguments Struct.pack() expects, not including the format string argument. */
|
|
#define WSLUA_ARG_Struct_values_FORMAT 1 /* The format string */
|
|
Header h;
|
|
const gchar *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_values_FORMAT);
|
|
size_t vals = 0;
|
|
defaultoptions(&h);
|
|
while (*fmt) {
|
|
int opt = *fmt++;
|
|
/* we use a size != 0 to mean it is a value */
|
|
size_t size = optsize(L, opt, &fmt);
|
|
/* but some will be zero and not be a value, or vice-versa */
|
|
switch (opt) {
|
|
case 's': case 'c':
|
|
/* these are values */
|
|
size = 1;
|
|
break;
|
|
case 'x': case 'X':
|
|
/* these are not */
|
|
size = 0;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
if (!g_ascii_isalnum(opt))
|
|
controloptions(L, opt, &fmt, &h);
|
|
else if (size && !h.noassign)
|
|
vals++;
|
|
}
|
|
lua_pushinteger(L, vals);
|
|
WSLUA_RETURN(1); /* The number of values */
|
|
}
|
|
|
|
WSLUA_CONSTRUCTOR Struct_tohex (lua_State *L) {
|
|
/* Converts the passed-in binary string to a hex-ascii string. */
|
|
#define WSLUA_ARG_Struct_tohex_BYTESTRING 1 /* A Lua string consisting of binary bytes */
|
|
#define WSLUA_OPTARG_Struct_tohex_LOWERCASE 2 /* True to use lower-case hex characters (default=false). */
|
|
#define WSLUA_OPTARG_Struct_tohex_SEPARATOR 3 /* A string separator to insert between hex bytes (default=nil). */
|
|
const gchar* s = NULL;
|
|
size_t len = 0;
|
|
gboolean lowercase = FALSE;
|
|
const gchar* sep = NULL;
|
|
|
|
/* luaL_checklstring coerces the argument to a string, and that's ok for tohex,
|
|
just not fromhex. In fact, we should accept/coerce a Int64/UInt64 here too someday. */
|
|
s = luaL_checklstring(L, WSLUA_ARG_Struct_tohex_BYTESTRING, &len);
|
|
|
|
lowercase = wslua_optbool(L,WSLUA_OPTARG_Struct_tohex_LOWERCASE,FALSE);
|
|
sep = luaL_optstring(L,WSLUA_OPTARG_Struct_tohex_SEPARATOR,NULL);
|
|
|
|
wslua_bin2hex(L, s, (guint)len, lowercase, sep);
|
|
WSLUA_RETURN(1); /* The Lua hex-ascii string */
|
|
}
|
|
|
|
WSLUA_CONSTRUCTOR Struct_fromhex (lua_State *L) {
|
|
/* Converts the passed-in hex-ascii string to a binary string. */
|
|
#define WSLUA_ARG_Struct_fromhex_HEXBYTES 1 /* A string consisting of hexadecimal bytes like "00 B1 A2" or "1a2b3c4d" */
|
|
#define WSLUA_OPTARG_Struct_fromhex_SEPARATOR 2 /* A string separator between hex bytes/words (default none). */
|
|
const gchar* s = NULL;
|
|
size_t len = 0;
|
|
const gchar* sep = NULL;
|
|
|
|
/* luaL_checklstring coerces the argument to a string, and we don't want to do that */
|
|
s = wslua_checklstring_only(L, WSLUA_ARG_Struct_fromhex_HEXBYTES, &len);
|
|
|
|
sep = luaL_optstring(L,WSLUA_OPTARG_Struct_fromhex_SEPARATOR,NULL);
|
|
|
|
wslua_hex2bin(L, s, (guint)len, sep);
|
|
WSLUA_RETURN(1); /* The Lua binary string */
|
|
}
|
|
|
|
/* }====================================================== */
|
|
|
|
/* Gets registered as metamethod automatically by WSLUA_REGISTER_CLASS/META */
|
|
static int Struct__gc(lua_State* L _U_) {
|
|
return 0;
|
|
}
|
|
|
|
WSLUA_METHODS Struct_methods[] = {
|
|
WSLUA_CLASS_FNREG(Struct,pack),
|
|
WSLUA_CLASS_FNREG(Struct,unpack),
|
|
WSLUA_CLASS_FNREG(Struct,size),
|
|
WSLUA_CLASS_FNREG(Struct,values),
|
|
WSLUA_CLASS_FNREG(Struct,tohex),
|
|
WSLUA_CLASS_FNREG(Struct,fromhex),
|
|
{ NULL, NULL }
|
|
};
|
|
|
|
WSLUA_META Struct_meta[] = {
|
|
{ NULL, NULL }
|
|
};
|
|
|
|
LUALIB_API int Struct_register(lua_State* L) {
|
|
WSLUA_REGISTER_CLASS(Struct);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Editor modelines - http://www.wireshark.org/tools/modelines.html
|
|
*
|
|
* Local Variables:
|
|
* c-basic-offset: 2
|
|
* tab-width: 8
|
|
* indent-tabs-mode: nil
|
|
* End:
|
|
*
|
|
* vi: set shiftwidth=2 tabstop=8 expandtab:
|
|
* :indentSize=2:tabSize=8:noTabs=true:
|
|
*/
|