| File: | epan/wslua/wslua_struct.c |
| Warning: | line 453, column 48 The result of left shift is undefined because the right operand is negative |
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| 1 | /****************************************************************************** | |||
| 2 | * Copyright (C) 2010-2012 Lua.org, PUC-Rio. All rights reserved. | |||
| 3 | * | |||
| 4 | * SPDX-License-Identifier: MIT | |||
| 5 | * | |||
| 6 | ******************************************************************************/ | |||
| 7 | /* | |||
| 8 | ** {====================================================== | |||
| 9 | ** Library for packing/unpacking structures. | |||
| 10 | ** See Copyright Notice above. | |||
| 11 | ** | |||
| 12 | ** Small changes were made by Hadriel Kaplan - those changes | |||
| 13 | ** are in the Public Domain. | |||
| 14 | ** | |||
| 15 | ** Some changes are based on a patch to struct.h from | |||
| 16 | ** Flemming Madsen, from here: | |||
| 17 | ** http://lua-users.org/lists/lua-l/2009-10/msg00572.html | |||
| 18 | ** In particular, these changes from him: | |||
| 19 | ** -Can handle 'long long' integers (i8 / I8); though they're converted to doubles | |||
| 20 | ** -Can insert/specify padding anywhere in a struct. ('X' eg. when a string is following a union) | |||
| 21 | ** -Can report current offset in both pack and unpack ('=') | |||
| 22 | ** -Can mask out return values when you only want to calculate sizes or unmarshal pascal-style strings. '(' & ')' | |||
| 23 | ** | |||
| 24 | ** Changes I made: | |||
| 25 | ** -Added support for Int64/UInt64 being packed/unpacked, using 'e'/'E' | |||
| 26 | ** -Made it follow Wireshark's conventions so we could get API docs | |||
| 27 | ** ======================================================= | |||
| 28 | */ | |||
| 29 | /* | |||
| 30 | ** Valid formats: | |||
| 31 | ** > - big endian | |||
| 32 | ** < - little endian | |||
| 33 | ** ![num] - alignment | |||
| 34 | ** x[num] - pad num bytes, default 1 | |||
| 35 | ** X[num] - pad to num align, default MAXALIGN | |||
| 36 | ** | |||
| 37 | ** Following are system-dependent sizes: | |||
| 38 | ** i/I - signed/unsigned int | |||
| 39 | ** l/L - signed/unsigned long | |||
| 40 | ** f - float | |||
| 41 | ** T - size_t | |||
| 42 | ** | |||
| 43 | ** Following are system-independent sizes: | |||
| 44 | ** b/B - signed/unsigned byte | |||
| 45 | ** h/H - signed/unsigned short | |||
| 46 | ** in/In - signed/unsigned integer of size `n' bytes | |||
| 47 | Note: Unpack of i/I is done to a Lua_number, typically a double, | |||
| 48 | so unpacking a 64-bit field (i8/I8) will lose precision. | |||
| 49 | Use e/E to unpack into a Wireshark Int64/UInt64 object/userdata instead. | |||
| 50 | ** e/E - signed/unsigned eight-byte Integer (64bits, long long), to/from Int64/UInt64 object | |||
| 51 | ** d - double | |||
| 52 | ** cn - sequence of `n' chars (from/to a string); when packing, n==0 means | |||
| 53 | the whole string; when unpacking, n==0 means use the previous | |||
| 54 | read number as the string length | |||
| 55 | ** s - zero-terminated string | |||
| 56 | ** ' ' - ignored | |||
| 57 | ** '(' ')' - stop assigning items. ')' start assigning (padding when packing) | |||
| 58 | ** '=' - return current position / offset | |||
| 59 | */ | |||
| 60 | ||||
| 61 | #include "config.h" | |||
| 62 | ||||
| 63 | #include <limits.h> | |||
| 64 | #include <wsutil/array.h> | |||
| 65 | #include "wslua.h" | |||
| 66 | ||||
| 67 | /* WSLUA_MODULE Struct Binary encode/decode support | |||
| 68 | ||||
| 69 | The Struct class offers basic facilities to convert Lua values to and from C-style structs | |||
| 70 | in binary Lua strings. This is based on Roberto Ierusalimschy's Lua struct library found | |||
| 71 | in http://www.inf.puc-rio.br/~roberto/struct/, with some minor modifications as follows: | |||
| 72 | * Added support for `Int64`/`UInt64` being packed/unpacked, using 'e'/'E'. | |||
| 73 | * Can handle 'long long' integers (i8 / I8); though they're converted to doubles. | |||
| 74 | * Can insert/specify padding anywhere in a struct. ('X' eg. when a string is following a union). | |||
| 75 | * Can report current offset in both `pack` and `unpack` ('`=`'). | |||
| 76 | * Can mask out return values when you only want to calculate sizes or unmarshal | |||
| 77 | pascal-style strings using '`(`' & '`)`'. | |||
| 78 | ||||
| 79 | All but the first of those changes are based on an email from Flemming Madsen, on the lua-users | |||
| 80 | mailing list, which can be found http://lua-users.org/lists/lua-l/2009-10/msg00572.html[here]. | |||
| 81 | ||||
| 82 | The main functions are `Struct.pack`, which packs multiple Lua values into a struct-like | |||
| 83 | Lua binary string; and `Struct.unpack`, which unpacks multiple Lua values from a given | |||
| 84 | struct-like Lua binary string. There are some additional helper functions available as well. | |||
| 85 | ||||
| 86 | All functions in the Struct library are called as static member functions, not object methods, | |||
| 87 | so they are invoked as "Struct.pack(...)" instead of "object:pack(...)". | |||
| 88 | ||||
| 89 | The fist argument to several of the `Struct` functions is a format string, which describes | |||
| 90 | the layout of the structure. The format string is a sequence of conversion elements, which | |||
| 91 | respect the current endianness and the current alignment requirements. Initially, the | |||
| 92 | current endianness is the machine's native endianness and the current alignment requirement | |||
| 93 | is 1 (meaning no alignment at all). You can change these settings with appropriate directives | |||
| 94 | in the format string. | |||
| 95 | ||||
| 96 | The supported elements in the format string are as follows: | |||
| 97 | ||||
| 98 | * `$$ $$' (empty space) ignored. | |||
| 99 | * `++!++__n__' flag to set the current alignment requirement to 'n' (necessarily a power of 2); | |||
| 100 | an absent 'n' means the machine's native alignment. | |||
| 101 | * `++>++' flag to set mode to big endian (i.e., network-order). | |||
| 102 | * `++<++' flag to set mode to little endian. | |||
| 103 | * `++x++' a padding zero byte with no corresponding Lua value. | |||
| 104 | * `++b++' a signed char. | |||
| 105 | * `++B++' an unsigned char. | |||
| 106 | * `++h++' a signed short (native size). | |||
| 107 | * `++H++' an unsigned short (native size). | |||
| 108 | * `++l++' a signed long (native size). | |||
| 109 | * `++L++' an unsigned long (native size). | |||
| 110 | * `++T++' a size_t (native size). | |||
| 111 | * `++i++__n__' a signed integer with 'n' bytes. An absent 'n' means the native size of an int. | |||
| 112 | * `++I++__n__' like `++i++__n__' but unsigned. | |||
| 113 | * `++e++' signed 8-byte Integer (64-bits, long long), to/from a +Int64+ object. | |||
| 114 | * `++E++' unsigned 8-byte Integer (64-bits, long long), to/from a +UInt64+ object. | |||
| 115 | * `++f++' a float (native size). | |||
| 116 | * `++d++' a double (native size). | |||
| 117 | * `++s++' a zero-terminated string. | |||
| 118 | * `++c++__n__' a sequence of exactly 'n' chars corresponding to a single Lua string. An absent 'n' | |||
| 119 | means 1. When packing, the given string must have at least 'n' characters (extra | |||
| 120 | characters are discarded). | |||
| 121 | * `++c0++' this is like `++c++__n__', except that the 'n' is given by other means: When packing, 'n' is | |||
| 122 | the length of the given string; when unpacking, 'n' is the value of the previous unpacked | |||
| 123 | value (which must be a number). In that case, this previous value is not returned. | |||
| 124 | * `++x++__n__' pad to 'n' number of bytes, default 1. | |||
| 125 | * `++X++__n__' pad to 'n' alignment, default MAXALIGN. | |||
| 126 | * `++(++' to stop assigning items, and `++)++' start assigning (padding when packing). | |||
| 127 | * `++=++' to return the current position / offset. | |||
| 128 | ||||
| 129 | [IMPORTANT] | |||
| 130 | ==== | |||
| 131 | Using `i`, `I`, `h`, `H`, `l`, `L`, `f`, and `T` is strongly discouraged, as those sizes | |||
| 132 | are system-dependent. Use the explicitly sized variants instead, such as `i4` or `E`. | |||
| 133 | ||||
| 134 | Unpacking of `i`/`I` is done to a Lua number, a double-precision floating point, | |||
| 135 | so unpacking a 64-bit field (`i8`/`I8`) will lose precision. | |||
| 136 | Use `e`/`E` to unpack into a Wireshark `Int64`/`UInt64` object instead. | |||
| 137 | ==== | |||
| 138 | ||||
| 139 | [NOTE] | |||
| 140 | ==== | |||
| 141 | Lua 5.3 and later provides several built-in functions for struct unpacking and packing: | |||
| 142 | https://www.lua.org/manual/5.4/manual.html#pdf-string.pack[string.pack], | |||
| 143 | https://www.lua.org/manual/5.4/manual.html#pdf-string.packsize[string.packsize], and | |||
| 144 | https://www.lua.org/manual/5.4/manual.html#pdf-string.unpack[string.unpack]. | |||
| 145 | You can use those as well, but note that the | |||
| 146 | https://www.lua.org/manual/5.4/manual.html#6.4.2[format string] conversion elements | |||
| 147 | are slightly different, and they do not support the Wireshark `Int64`/`UInt64` objects. | |||
| 148 | ==== | |||
| 149 | */ | |||
| 150 | ||||
| 151 | ||||
| 152 | /* The following line is here so that make-reg.py does the right thing. This 'Struct' class | |||
| 153 | isn't really a class, so it doesn't have the checkStruct/pushStruct/etc. functions | |||
| 154 | the following macro would generate; but it does need to be registered and such, so... | |||
| 155 | WSLUA_CLASS_DEFINE_BASE(Struct,NOP,0); | |||
| 156 | */ | |||
| 157 | ||||
| 158 | /* basic integer type - yes this is system-specific size - it's meant to be */ | |||
| 159 | #if !defined(STRUCT_INTlong) | |||
| 160 | #define STRUCT_INTlong long | |||
| 161 | #endif | |||
| 162 | ||||
| 163 | typedef STRUCT_INTlong Inttype; | |||
| 164 | ||||
| 165 | /* corresponding unsigned version */ | |||
| 166 | typedef unsigned STRUCT_INTlong Uinttype; | |||
| 167 | ||||
| 168 | /* maximum size (in bytes) for integral types */ | |||
| 169 | #define MAXINTSIZE32 32 | |||
| 170 | ||||
| 171 | /* is 'x' a power of 2? */ | |||
| 172 | #define isp2(x)((x) > 0 && ((x) & ((x) - 1)) == 0) ((x) > 0 && ((x) & ((x) - 1)) == 0) | |||
| 173 | ||||
| 174 | /* dummy structure to get padding/alignment requirements */ | |||
| 175 | struct cD { | |||
| 176 | char c; | |||
| 177 | double d; | |||
| 178 | }; | |||
| 179 | ||||
| 180 | ||||
| 181 | #define PADDING(sizeof(struct cD) - sizeof(double)) (sizeof(struct cD) - sizeof(double)) | |||
| 182 | #define MAXALIGN((sizeof(struct cD) - sizeof(double)) > sizeof(int) ? (sizeof (struct cD) - sizeof(double)) : sizeof(int)) (PADDING(sizeof(struct cD) - sizeof(double)) > sizeof(int) ? PADDING(sizeof(struct cD) - sizeof(double)) : sizeof(int)) | |||
| 183 | ||||
| 184 | ||||
| 185 | /* endian options */ | |||
| 186 | #define BIG0 0 | |||
| 187 | #define LITTLE1 1 | |||
| 188 | ||||
| 189 | /* trick to determine native endianness of system */ | |||
| 190 | static union { | |||
| 191 | int dummy; | |||
| 192 | char endian; | |||
| 193 | } const native = {1}; | |||
| 194 | ||||
| 195 | /* settings info */ | |||
| 196 | typedef struct Header { | |||
| 197 | int endian; | |||
| 198 | int align; | |||
| 199 | bool_Bool noassign; | |||
| 200 | } Header; | |||
| 201 | ||||
| 202 | /* For options that take a number argument, gets the number */ | |||
| 203 | static int getnum (lua_State *L, const char **fmt, int df) { | |||
| 204 | if (!g_ascii_isdigit(**fmt)((g_ascii_table[(guchar) (**fmt)] & G_ASCII_DIGIT) != 0)) /* no number? */ | |||
| 205 | return df; /* return default value */ | |||
| 206 | else { | |||
| 207 | int a = 0; | |||
| 208 | do { | |||
| 209 | if (a > (INT_MAX2147483647 / 10) || a * 10 > (INT_MAX2147483647 - (**fmt - '0'))) | |||
| 210 | luaL_error(L, "integral size overflow"); | |||
| 211 | a = a*10 + *((*fmt)++) - '0'; | |||
| 212 | } while (g_ascii_isdigit(**fmt)((g_ascii_table[(guchar) (**fmt)] & G_ASCII_DIGIT) != 0)); | |||
| 213 | return a; | |||
| 214 | } | |||
| 215 | } | |||
| 216 | ||||
| 217 | ||||
| 218 | #define defaultoptions(h)((h)->endian = native.endian, (h)->align = 1, (h)->noassign = 0) ((h)->endian = native.endian, (h)->align = 1, (h)->noassign = false0) | |||
| 219 | ||||
| 220 | ||||
| 221 | /* gets size (number of bytes) for a given type */ | |||
| 222 | static size_t optsize (lua_State *L, char opt, const char **fmt) { | |||
| 223 | switch (opt) { | |||
| 224 | case 'B': case 'b': return sizeof(char); | |||
| 225 | case 'H': case 'h': return sizeof(short); | |||
| 226 | case 'L': case 'l': return sizeof(long); | |||
| 227 | case 'E': case 'e': return sizeof(int64_t); | |||
| 228 | case 'T': return sizeof(size_t); | |||
| 229 | case 'f': return sizeof(float); | |||
| 230 | case 'd': return sizeof(double); | |||
| 231 | case 'x': return getnum(L, fmt, 1); | |||
| 232 | case 'X': return getnum(L, fmt, MAXALIGN((sizeof(struct cD) - sizeof(double)) > sizeof(int) ? (sizeof (struct cD) - sizeof(double)) : sizeof(int))); | |||
| 233 | case 'c': return getnum(L, fmt, 1); | |||
| 234 | case 'i': case 'I': { | |||
| 235 | int sz = getnum(L, fmt, sizeof(int)); | |||
| 236 | if (sz > MAXINTSIZE32) | |||
| 237 | luaL_error(L, "integral size %d is larger than limit of %d", | |||
| 238 | sz, MAXINTSIZE32); | |||
| 239 | return sz; | |||
| 240 | } | |||
| 241 | case 's': case ' ': | |||
| 242 | case '<': case '>': | |||
| 243 | case '(': case ')': | |||
| 244 | case '!': case '=': | |||
| 245 | return 0; /* these cases do not have a size */ | |||
| 246 | default: { | |||
| 247 | const char *msg = lua_pushfstring(L, "invalid format option [%c]", opt); | |||
| 248 | return luaL_argerror(L, 1, msg); | |||
| 249 | } | |||
| 250 | } | |||
| 251 | } | |||
| 252 | ||||
| 253 | ||||
| 254 | /* | |||
| 255 | ** return number of bytes needed to align an element of size 'size' | |||
| 256 | ** at current position 'len' | |||
| 257 | */ | |||
| 258 | static int gettoalign (size_t len, Header *h, int opt, size_t size) { | |||
| 259 | if (size == 0 || opt == 'c' || opt == 's') return 0; | |||
| 260 | if (size > (size_t)h->align) | |||
| 261 | size = h->align; /* respect max. alignment */ | |||
| 262 | return (int)((size - (len & (size - 1))) & (size - 1)); | |||
| 263 | } | |||
| 264 | ||||
| 265 | ||||
| 266 | /* | |||
| 267 | ** options to control endianness and alignment settings | |||
| 268 | */ | |||
| 269 | static void controloptions (lua_State *L, int opt, const char **fmt, | |||
| 270 | Header *h) { | |||
| 271 | switch (opt) { | |||
| 272 | case ' ': return; /* ignore white spaces */ | |||
| 273 | case '>': h->endian = BIG0; return; | |||
| 274 | case '<': h->endian = LITTLE1; return; | |||
| 275 | case '(': h->noassign = true1; return; | |||
| 276 | case ')': h->noassign = false0; return; | |||
| 277 | case '!': { | |||
| 278 | int a = getnum(L, fmt, MAXALIGN((sizeof(struct cD) - sizeof(double)) > sizeof(int) ? (sizeof (struct cD) - sizeof(double)) : sizeof(int))); | |||
| 279 | if (!isp2(a)((a) > 0 && ((a) & ((a) - 1)) == 0)) | |||
| 280 | luaL_error(L, "alignment %d is not a power of 2", a); | |||
| 281 | h->align = a; | |||
| 282 | return; | |||
| 283 | } | |||
| 284 | default: { | |||
| 285 | const char *msg = lua_pushfstring(L, "invalid format option '%c'", opt); | |||
| 286 | luaL_argerror(L, 1, msg); | |||
| 287 | } | |||
| 288 | } | |||
| 289 | } | |||
| 290 | ||||
| 291 | /* Encodes a Lua number as an integer of given size and endianness into a string struct */ | |||
| 292 | static void putinteger (lua_State *L, luaL_Buffer *b, int arg, int endian, | |||
| 293 | int size) { | |||
| 294 | lua_Number n = luaL_checknumber(L, arg); | |||
| 295 | /* this one's not system dependent size - it's a long long */ | |||
| 296 | int64_t value; | |||
| 297 | char buff[MAXINTSIZE32]; | |||
| 298 | if (n < 0) | |||
| 299 | value = (uint64_t)(int64_t)n; | |||
| 300 | else | |||
| 301 | value = (uint64_t)n; | |||
| 302 | if (endian == LITTLE1) { | |||
| 303 | int i; | |||
| 304 | for (i = 0; i < size; i++) { | |||
| 305 | buff[i] = (value & 0xff); | |||
| 306 | value >>= 8; | |||
| 307 | } | |||
| 308 | } | |||
| 309 | else { | |||
| 310 | int i; | |||
| 311 | for (i = size - 1; i >= 0; i--) { | |||
| 312 | buff[i] = (value & 0xff); | |||
| 313 | value >>= 8; | |||
| 314 | } | |||
| 315 | } | |||
| 316 | luaL_addlstring(b, buff, size); | |||
| 317 | } | |||
| 318 | ||||
| 319 | /* corrects endianness - usually done by other functions themselves, but is | |||
| 320 | * used for float/doubles, since on some platforms they're endian'ed as well | |||
| 321 | */ | |||
| 322 | static void correctbytes (char *b, int size, int endian) { | |||
| 323 | if (endian != native.endian) { | |||
| 324 | int i = 0; | |||
| 325 | while (i < --size) { | |||
| 326 | char temp = b[i]; | |||
| 327 | b[i++] = b[size]; | |||
| 328 | b[size] = temp; | |||
| 329 | } | |||
| 330 | } | |||
| 331 | } | |||
| 332 | ||||
| 333 | ||||
| 334 | WSLUA_CONSTRUCTORstatic int Struct_pack (lua_State *L) { | |||
| 335 | /* Returns a string containing the values arg1, arg2, etc. packed/encoded according to the format string. */ | |||
| 336 | #define WSLUA_ARG_Struct_pack_FORMAT1 1 /* The format string */ | |||
| 337 | #define WSLUA_ARG_Struct_pack_VALUE2 2 /* One or more Lua value(s) to encode, based on the given format. */ | |||
| 338 | luaL_Buffer b; | |||
| 339 | const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_pack_FORMAT1); | |||
| 340 | Header h; | |||
| 341 | int poscnt = 0; | |||
| 342 | int posBuf[10]; | |||
| 343 | int arg = 2; | |||
| 344 | size_t totalsize = 0; | |||
| 345 | defaultoptions(&h)((&h)->endian = native.endian, (&h)->align = 1, (&h)->noassign = 0); | |||
| 346 | lua_pushnil(L); /* mark to separate arguments from string buffer */ | |||
| 347 | luaL_buffinit(L, &b); | |||
| 348 | while (*fmt != '\0') { | |||
| 349 | int opt = *fmt++; | |||
| 350 | size_t size = optsize(L, opt, &fmt); | |||
| 351 | int toalign = gettoalign(totalsize, &h, opt, size); | |||
| 352 | totalsize += toalign; | |||
| 353 | while (toalign-- > 0) luaL_addchar(&b, '\0')((void)((&b)->n < (&b)->size || luaL_prepbuffsize ((&b), 1)), ((&b)->b[(&b)->n++] = ('\0'))); | |||
| 354 | if (opt == 'X') size = 0; /* 'X' is about alignment, not size */ | |||
| 355 | if (h.noassign && size) opt = 'x'; /* for pack, "(i4)" is the same as "x4" */ | |||
| 356 | switch (opt) { | |||
| 357 | case 'b': case 'B': case 'h': case 'H': | |||
| 358 | case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */ | |||
| 359 | putinteger(L, &b, arg++, h.endian, (int)size); | |||
| 360 | break; | |||
| 361 | } | |||
| 362 | case 'e': { | |||
| 363 | Int64_pack(L, &b, arg++, h.endian == LITTLE1); | |||
| 364 | break; | |||
| 365 | } | |||
| 366 | case 'E': { | |||
| 367 | UInt64_pack(L, &b, arg++, h.endian == LITTLE1); | |||
| 368 | break; | |||
| 369 | } | |||
| 370 | case 'x': case 'X': { | |||
| 371 | size_t len = size; | |||
| 372 | while (len-- > 0) | |||
| 373 | luaL_addchar(&b, '\0')((void)((&b)->n < (&b)->size || luaL_prepbuffsize ((&b), 1)), ((&b)->b[(&b)->n++] = ('\0'))); | |||
| 374 | break; | |||
| 375 | } | |||
| 376 | case 'f': { | |||
| 377 | float f = (float)luaL_checknumber(L, arg++); | |||
| 378 | correctbytes((char *)&f, (int)size, h.endian); | |||
| 379 | luaL_addlstring(&b, (char *)&f, size); | |||
| 380 | break; | |||
| 381 | } | |||
| 382 | case 'd': { | |||
| 383 | double d = luaL_checknumber(L, arg++); | |||
| 384 | correctbytes((char *)&d, (int)size, h.endian); | |||
| 385 | luaL_addlstring(&b, (char *)&d, size); | |||
| 386 | break; | |||
| 387 | } | |||
| 388 | case 'c': case 's': { | |||
| 389 | size_t l; | |||
| 390 | const char *s = luaL_checklstring(L, arg++, &l); | |||
| 391 | if (size == 0) size = l; | |||
| 392 | luaL_argcheck(L, l >= (size_t)size, arg, "string too short")((void)((__builtin_expect(((l >= (size_t)size) != 0), 1)) || luaL_argerror(L, (arg), ("string too short")))); | |||
| 393 | luaL_addlstring(&b, s, size); | |||
| 394 | if (opt == 's') { | |||
| 395 | luaL_addchar(&b, '\0')((void)((&b)->n < (&b)->size || luaL_prepbuffsize ((&b), 1)), ((&b)->b[(&b)->n++] = ('\0'))); /* add zero at the end */ | |||
| 396 | size++; | |||
| 397 | } | |||
| 398 | break; | |||
| 399 | } | |||
| 400 | case '=': { | |||
| 401 | if (poscnt < (int)array_length(posBuf)(sizeof (posBuf) / sizeof (posBuf)[0])) | |||
| 402 | posBuf[poscnt++] = (int)totalsize + 1; | |||
| 403 | break; | |||
| 404 | } | |||
| 405 | default: controloptions(L, opt, &fmt, &h); | |||
| 406 | } | |||
| 407 | totalsize += size; | |||
| 408 | } | |||
| 409 | luaL_pushresult(&b); | |||
| 410 | for (arg = 0; arg < poscnt; arg++) | |||
| 411 | lua_pushinteger(L, posBuf[arg]); | |||
| 412 | WSLUA_RETURN(poscnt + 1)return (poscnt + 1); /* The packed binary Lua string, plus any positions due to '=' being used in format. */ | |||
| 413 | } | |||
| 414 | ||||
| 415 | static Uinttype decodeinteger (const char *buff, int endian, int size) | |||
| 416 | { | |||
| 417 | Uinttype l = 0; | |||
| 418 | int i; | |||
| 419 | if (endian == BIG0) { | |||
| 420 | for (i = 0; i < size; i++) { | |||
| 421 | l <<= 8; | |||
| 422 | l |= (Uinttype)(unsigned char)buff[i]; | |||
| 423 | } | |||
| 424 | } | |||
| 425 | else { | |||
| 426 | for (i = size - 1; i >= 0; i--) { | |||
| 427 | l <<= 8; | |||
| 428 | l |= (Uinttype)(unsigned char)buff[i]; | |||
| 429 | } | |||
| 430 | } | |||
| 431 | return l; | |||
| 432 | } | |||
| 433 | ||||
| 434 | /* Decodes an integer from a string struct into a lua_Integer, if it fits | |||
| 435 | * without truncation, or a lua_Number, based on given endianness and size. | |||
| 436 | * If the integer type is signed, that is handled correctly as well. | |||
| 437 | * Note for large values of size there can be a loss of precision. | |||
| 438 | */ | |||
| 439 | static void getinteger (lua_State *L, const char *buff, int endian, | |||
| 440 | int issigned, int size) { | |||
| 441 | Uinttype l = decodeinteger(buff, endian, size); | |||
| 442 | if (!issigned
| |||
| 443 | if (size < LUA_INTEGER_SIZE8) { | |||
| 444 | /* Fits in a lua_Integer (we need a larger size as lua_Integer | |||
| 445 | * is signed.) */ | |||
| 446 | lua_pushinteger(L, (lua_Integer)l); | |||
| 447 | } else { | |||
| 448 | /* Does not fit in a lua_Integer */ | |||
| 449 | lua_pushnumber(L, (lua_Number)l); | |||
| 450 | } | |||
| 451 | } | |||
| 452 | else { /* signed format */ | |||
| 453 | Uinttype mask = (Uinttype)(~((Uinttype)0)) << (size*8 - 1); | |||
| ||||
| 454 | if (l & mask) /* negative value? */ | |||
| 455 | l |= mask; /* sign extension */ | |||
| 456 | if (size <= LUA_INTEGER_SIZE8) { | |||
| 457 | /* Fits in a lua_Integer */ | |||
| 458 | lua_pushinteger(L, (lua_Integer)(Inttype)l); | |||
| 459 | } else { | |||
| 460 | /* Does not fit in a lua_Integer */ | |||
| 461 | lua_pushnumber(L, (lua_Number)(Inttype)l); | |||
| 462 | } | |||
| 463 | } | |||
| 464 | } | |||
| 465 | ||||
| 466 | #define b_pushnumber(n){ if (!h.noassign) lua_pushnumber(L, (lua_Number)(n)); } { if (!h.noassign) lua_pushnumber(L, (lua_Number)(n)); } | |||
| 467 | ||||
| 468 | WSLUA_CONSTRUCTORstatic int Struct_unpack (lua_State *L) { | |||
| 469 | /* Unpacks/decodes multiple Lua values from a given struct-like binary Lua string. | |||
| 470 | The number of returned values depends on the format given, plus an additional value of the position where it stopped reading is returned. */ | |||
| 471 | #define WSLUA_ARG_Struct_unpack_FORMAT1 1 /* The format string */ | |||
| 472 | #define WSLUA_ARG_Struct_unpack_STRUCT2 2 /* The binary Lua string to unpack */ | |||
| 473 | #define WSLUA_OPTARG_Struct_unpack_BEGIN3 3 /* The position to begin reading from (default=1) */ | |||
| 474 | Header h; | |||
| 475 | const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_unpack_FORMAT1); | |||
| 476 | size_t ld; | |||
| 477 | const char *data = wslua_checklstring_only(L, WSLUA_ARG_Struct_unpack_STRUCT2, &ld); | |||
| 478 | size_t pos = luaL_optinteger(L, WSLUA_OPTARG_Struct_unpack_BEGIN3, 1) - 1; | |||
| 479 | defaultoptions(&h)((&h)->endian = native.endian, (&h)->align = 1, (&h)->noassign = 0); | |||
| 480 | lua_settop(L, 2); | |||
| 481 | while (*fmt) { | |||
| ||||
| 482 | int opt = *fmt++; | |||
| 483 | size_t size = optsize(L, opt, &fmt); | |||
| 484 | pos += gettoalign(pos, &h, opt, size); | |||
| 485 | luaL_argcheck(L, pos+size <= ld, 2, "data string too short")((void)((__builtin_expect(((pos+size <= ld) != 0), 1)) || luaL_argerror (L, (2), ("data string too short")))); | |||
| 486 | ||||
| 487 | if (opt == 'X') size = 0; | |||
| 488 | if (h.noassign
| |||
| 489 | /* if we're not assigning, and the opt type has a size, then loop again */ | |||
| 490 | /* this will not be the case for control options, 'c0', 's', and '=' */ | |||
| 491 | pos += size; | |||
| 492 | continue; | |||
| 493 | } | |||
| 494 | ||||
| 495 | luaL_checkstack(L, 1, "too many results"); | |||
| 496 | switch (opt) { | |||
| 497 | case 'b': case 'B': case 'h': case 'H': | |||
| 498 | case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */ | |||
| 499 | int issigned = g_ascii_islower(opt)((g_ascii_table[(guchar) (opt)] & G_ASCII_LOWER) != 0); | |||
| 500 | getinteger(L, data+pos, h.endian, issigned, (int)size); | |||
| 501 | break; | |||
| 502 | } | |||
| 503 | case 'e': { | |||
| 504 | Int64_unpack(L, data+pos, h.endian == LITTLE1); | |||
| 505 | break; | |||
| 506 | } | |||
| 507 | case 'E': { | |||
| 508 | UInt64_unpack(L, data+pos, h.endian == LITTLE1); | |||
| 509 | break; | |||
| 510 | } | |||
| 511 | case 'x': case 'X': { | |||
| 512 | break; | |||
| 513 | } | |||
| 514 | case 'f': { | |||
| 515 | float f; | |||
| 516 | memcpy(&f, data+pos, size); | |||
| 517 | correctbytes((char *)&f, sizeof(f), h.endian); | |||
| 518 | lua_pushnumber(L, f); | |||
| 519 | break; | |||
| 520 | } | |||
| 521 | case 'd': { | |||
| 522 | double d; | |||
| 523 | memcpy(&d, data+pos, size); | |||
| 524 | correctbytes((char *)&d, sizeof(d), h.endian); | |||
| 525 | lua_pushnumber(L, d); | |||
| 526 | break; | |||
| 527 | } | |||
| 528 | case 'c': { | |||
| 529 | if (size == 0) { | |||
| 530 | if (!lua_isnumber(L, -1)) | |||
| 531 | luaL_error(L, "format `c0' needs a previous size"); | |||
| 532 | size = wslua_touint32(L, -1)(uint32_t) ( lua_tointegerx(L,(-1),((void*)0)) ); | |||
| 533 | lua_pop(L, 1)lua_settop(L, -(1)-1); | |||
| 534 | luaL_argcheck(L, pos+size <= ld, 2, "data string too short")((void)((__builtin_expect(((pos+size <= ld) != 0), 1)) || luaL_argerror (L, (2), ("data string too short")))); | |||
| 535 | } | |||
| 536 | if (!h.noassign) | |||
| 537 | lua_pushlstring(L, data+pos, size); | |||
| 538 | break; | |||
| 539 | } | |||
| 540 | case 's': { | |||
| 541 | const char *e = (const char *)memchr(data+pos, '\0', ld - pos); | |||
| 542 | if (e == NULL((void*)0)) | |||
| 543 | luaL_error(L, "unfinished string in data"); | |||
| 544 | size = (e - (data+pos)) + 1; | |||
| 545 | if (!h.noassign) | |||
| 546 | lua_pushlstring(L, data+pos, size - 1); | |||
| 547 | break; | |||
| 548 | } | |||
| 549 | case '=': { | |||
| 550 | lua_pushinteger(L, pos + 1); | |||
| 551 | break; | |||
| 552 | } | |||
| 553 | default: controloptions(L, opt, &fmt, &h); | |||
| 554 | } | |||
| 555 | pos += size; | |||
| 556 | } | |||
| 557 | lua_pushinteger(L, pos + 1); | |||
| 558 | WSLUA_RETURN(lua_gettop(L) - 2)return (lua_gettop(L) - 2); /* One or more values based on format, plus the position it stopped unpacking. */ | |||
| 559 | } | |||
| 560 | ||||
| 561 | ||||
| 562 | WSLUA_CONSTRUCTORstatic int Struct_size (lua_State *L) { | |||
| 563 | /* Returns the length of a binary string that would be consumed/handled by the given format string. */ | |||
| 564 | #define WSLUA_ARG_Struct_size_FORMAT1 1 /* The format string */ | |||
| 565 | Header h; | |||
| 566 | const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_size_FORMAT1); | |||
| 567 | size_t pos = 0; | |||
| 568 | defaultoptions(&h)((&h)->endian = native.endian, (&h)->align = 1, (&h)->noassign = 0); | |||
| 569 | while (*fmt) { | |||
| 570 | int opt = *fmt++; | |||
| 571 | size_t size = optsize(L, opt, &fmt); | |||
| 572 | pos += gettoalign(pos, &h, opt, size); | |||
| 573 | if (opt == 's') | |||
| 574 | luaL_argerror(L, 1, "option 's' has no fixed size"); | |||
| 575 | else if (opt == 'c' && size == 0) | |||
| 576 | luaL_argerror(L, 1, "option 'c0' has no fixed size"); | |||
| 577 | if (!g_ascii_isalnum(opt)((g_ascii_table[(guchar) (opt)] & G_ASCII_ALNUM) != 0)) | |||
| 578 | controloptions(L, opt, &fmt, &h); | |||
| 579 | pos += size; | |||
| 580 | } | |||
| 581 | lua_pushinteger(L, pos); | |||
| 582 | WSLUA_RETURN(1)return (1); /* The size number */ | |||
| 583 | } | |||
| 584 | ||||
| 585 | WSLUA_CONSTRUCTORstatic int Struct_values (lua_State *L) { | |||
| 586 | /* Returns the number of Lua values contained in the given format string. | |||
| 587 | This will be the number of returned values from a call to Struct.unpack() | |||
| 588 | not including the extra return value of offset position. (i.e., Struct.values() | |||
| 589 | does not count that extra return value) This will also be the number of | |||
| 590 | arguments Struct.pack() expects, not including the format string argument. */ | |||
| 591 | #define WSLUA_ARG_Struct_values_FORMAT1 1 /* The format string */ | |||
| 592 | Header h; | |||
| 593 | const char *fmt = wslua_checkstring_only(L, WSLUA_ARG_Struct_values_FORMAT1); | |||
| 594 | size_t vals = 0; | |||
| 595 | defaultoptions(&h)((&h)->endian = native.endian, (&h)->align = 1, (&h)->noassign = 0); | |||
| 596 | while (*fmt) { | |||
| 597 | int opt = *fmt++; | |||
| 598 | /* we use a size != 0 to mean it is a value */ | |||
| 599 | size_t size = optsize(L, opt, &fmt); | |||
| 600 | /* but some will be zero and not be a value, or vice-versa */ | |||
| 601 | switch (opt) { | |||
| 602 | case 's': case 'c': | |||
| 603 | /* these are values */ | |||
| 604 | size = 1; | |||
| 605 | break; | |||
| 606 | case 'x': case 'X': | |||
| 607 | /* these are not */ | |||
| 608 | size = 0; | |||
| 609 | break; | |||
| 610 | default: | |||
| 611 | break; | |||
| 612 | } | |||
| 613 | if (!g_ascii_isalnum(opt)((g_ascii_table[(guchar) (opt)] & G_ASCII_ALNUM) != 0)) | |||
| 614 | controloptions(L, opt, &fmt, &h); | |||
| 615 | else if (size && !h.noassign) | |||
| 616 | vals++; | |||
| 617 | } | |||
| 618 | lua_pushinteger(L, vals); | |||
| 619 | WSLUA_RETURN(1)return (1); /* The number of values */ | |||
| 620 | } | |||
| 621 | ||||
| 622 | WSLUA_CONSTRUCTORstatic int Struct_tohex (lua_State *L) { | |||
| 623 | /* Converts the passed-in binary string to a hex-ascii string. */ | |||
| 624 | #define WSLUA_ARG_Struct_tohex_BYTESTRING1 1 /* A Lua string consisting of binary bytes */ | |||
| 625 | #define WSLUA_OPTARG_Struct_tohex_LOWERCASE2 2 /* True to use lower-case hex characters (default=false). */ | |||
| 626 | #define WSLUA_OPTARG_Struct_tohex_SEPARATOR3 3 /* A string separator to insert between hex bytes (default=nil). */ | |||
| 627 | const char* s = NULL((void*)0); | |||
| 628 | size_t len = 0; | |||
| 629 | bool_Bool lowercase = false0; | |||
| 630 | const char* sep = NULL((void*)0); | |||
| 631 | ||||
| 632 | /* luaL_checklstring coerces the argument to a string, and that's ok for tohex, | |||
| 633 | just not fromhex. In fact, we should accept/coerce a Int64/UInt64 here too someday. */ | |||
| 634 | s = luaL_checklstring(L, WSLUA_ARG_Struct_tohex_BYTESTRING1, &len); | |||
| 635 | ||||
| 636 | lowercase = wslua_optbool(L,WSLUA_OPTARG_Struct_tohex_LOWERCASE2,false0); | |||
| 637 | sep = luaL_optstring(L,WSLUA_OPTARG_Struct_tohex_SEPARATOR,NULL)(luaL_optlstring(L, (3), (((void*)0)), ((void*)0))); | |||
| 638 | ||||
| 639 | wslua_bin2hex(L, s, (unsigned)len, lowercase, sep); | |||
| 640 | WSLUA_RETURN(1)return (1); /* The Lua hex-ascii string */ | |||
| 641 | } | |||
| 642 | ||||
| 643 | WSLUA_CONSTRUCTORstatic int Struct_fromhex (lua_State *L) { | |||
| 644 | /* Converts the passed-in hex-ascii string to a binary string. */ | |||
| 645 | #define WSLUA_ARG_Struct_fromhex_HEXBYTES1 1 /* A string consisting of hexadecimal bytes like "00 B1 A2" or "1a2b3c4d" */ | |||
| 646 | #define WSLUA_OPTARG_Struct_fromhex_SEPARATOR2 2 /* A string separator between hex bytes/words (default none). */ | |||
| 647 | const char* s = NULL((void*)0); | |||
| 648 | size_t len = 0; | |||
| 649 | const char* sep = NULL((void*)0); | |||
| 650 | ||||
| 651 | /* luaL_checklstring coerces the argument to a string, and we don't want to do that */ | |||
| 652 | s = wslua_checklstring_only(L, WSLUA_ARG_Struct_fromhex_HEXBYTES1, &len); | |||
| 653 | ||||
| 654 | sep = luaL_optstring(L,WSLUA_OPTARG_Struct_fromhex_SEPARATOR,NULL)(luaL_optlstring(L, (2), (((void*)0)), ((void*)0))); | |||
| 655 | ||||
| 656 | wslua_hex2bin(L, s, (unsigned)len, sep); | |||
| 657 | WSLUA_RETURN(1)return (1); /* The Lua binary string */ | |||
| 658 | } | |||
| 659 | ||||
| 660 | /* }====================================================== */ | |||
| 661 | ||||
| 662 | /* Gets registered as metamethod automatically by WSLUA_REGISTER_CLASS/META */ | |||
| 663 | static int Struct__gc(lua_State* L _U___attribute__((unused))) { | |||
| 664 | return 0; | |||
| 665 | } | |||
| 666 | ||||
| 667 | WSLUA_METHODSstatic const luaL_Reg Struct_methods[] = { | |||
| 668 | WSLUA_CLASS_FNREG(Struct,pack){ "pack", Struct_pack }, | |||
| 669 | WSLUA_CLASS_FNREG(Struct,unpack){ "unpack", Struct_unpack }, | |||
| 670 | WSLUA_CLASS_FNREG(Struct,size){ "size", Struct_size }, | |||
| 671 | WSLUA_CLASS_FNREG(Struct,values){ "values", Struct_values }, | |||
| 672 | WSLUA_CLASS_FNREG(Struct,tohex){ "tohex", Struct_tohex }, | |||
| 673 | WSLUA_CLASS_FNREG(Struct,fromhex){ "fromhex", Struct_fromhex }, | |||
| 674 | { NULL((void*)0), NULL((void*)0) } | |||
| 675 | }; | |||
| 676 | ||||
| 677 | WSLUA_METAstatic const luaL_Reg Struct_meta[] = { | |||
| 678 | { NULL((void*)0), NULL((void*)0) } | |||
| 679 | }; | |||
| 680 | ||||
| 681 | LUALIB_APIextern int Struct_register(lua_State* L) { | |||
| 682 | WSLUA_REGISTER_CLASS(Struct){ const wslua_class Struct_class = { .name = "Struct", .class_methods = Struct_methods, .class_meta = Struct_meta, .instance_methods = Struct_methods, .instance_meta = Struct_meta, .attrs = ((void *)0) }; wslua_register_class(L, &Struct_class); (lua_getfield (L, (-1000000 - 1000), ("Struct"))); lua_pushcclosure(L, (Struct__gc ), 0); lua_setfield(L, -2, "__gc"); lua_settop(L, -(1)-1); }; | |||
| 683 | return 0; | |||
| 684 | } | |||
| 685 | ||||
| 686 | /* | |||
| 687 | * Editor modelines - https://www.wireshark.org/tools/modelines.html | |||
| 688 | * | |||
| 689 | * Local Variables: | |||
| 690 | * c-basic-offset: 2 | |||
| 691 | * tab-width: 8 | |||
| 692 | * indent-tabs-mode: nil | |||
| 693 | * End: | |||
| 694 | * | |||
| 695 | * vi: set shiftwidth=2 tabstop=8 expandtab: | |||
| 696 | * :indentSize=2:tabSize=8:noTabs=true: | |||
| 697 | */ |