diff options
Diffstat (limited to 'accel-pppd/lua/lua_lpack.c')
| -rw-r--r-- | accel-pppd/lua/lua_lpack.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/accel-pppd/lua/lua_lpack.c b/accel-pppd/lua/lua_lpack.c new file mode 100644 index 0000000..e9ceb85 --- /dev/null +++ b/accel-pppd/lua/lua_lpack.c @@ -0,0 +1,271 @@ +/* +* 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 Castaņo <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 */ +#define OP_BYTE 'b' /* byte = unsigned char */ +#define OP_SHORT 'h' /* short */ +#define OP_USHORT 'H' /* unsigned short */ +#define OP_INT 'i' /* int */ +#define OP_UINT 'I' /* unsigned int */ +#define OP_LONG 'l' /* long */ +#define OP_ULONG 'L' /* unsigned long */ +#define OP_LITTLEENDIAN '<' /* little endian */ +#define OP_BIGENDIAN '>' /* big endian */ +#define OP_NATIVE '=' /* native endian */ + +#include <ctype.h> +#include <stdint.h> +#include <string.h> + +#include "lua.h" +#include "lualib.h" +#include "lauxlib.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=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) goto done; \ + memcpy(&a,s+i,m); \ + i+=m; \ + doswap(swap,&a,m); \ + lua_pushinteger(L,(lua_Integer)a); \ + ++n; \ + break; \ + } + +#define UNPACKSTRING(OP,T) \ + case OP: \ + { \ + T l; \ + int m=sizeof(l); \ + if (i+m>len) goto done; \ + memcpy(&l,s+i,m); \ + doswap(swap,&l,m); \ + if (i+m+l>len) goto done; \ + i+=m; \ + lua_pushlstring(L,s+i,l); \ + i+=l; \ + ++n; \ + break; \ + } + +static int l_unpack(lua_State *L) /** unpack(s,f,[init]) */ +{ + size_t len; + const char *s=luaL_checklstring(L,1,&len); + const char *f=luaL_checkstring(L,2); + int i=luaL_optnumber(L,3,1)-1; + int n=0; + int swap=0; + lua_pushnil(L); + while (*f) + { + 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--) 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) goto done; + lua_pushlstring(L,s+i,N); + i+=N; + ++n; + N=0; + break; + } + case OP_ZSTRING: + { + size_t l; + if (i>=len) goto done; + l=strlen(s+i); + lua_pushlstring(L,s+i,l); + i+=l+1; + ++n; + break; + } + UNPACKSTRING(OP_BSTRING, unsigned char) + UNPACKSTRING(OP_WSTRING, unsigned short) + UNPACKSTRING(OP_SSTRING, size_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 ' ': case ',': + break; + default: + badcode(L,c); + break; + } + } +done: + 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,(void*)&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,(void*)&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, unsigned char) + PACKSTRING(OP_WSTRING, unsigned short) + PACKSTRING(OP_SSTRING, size_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 ' ': case ',': + break; + default: + badcode(L,c); + break; + } + } + luaL_pushresult(&b); + return 1; +} + +static const struct luaL_Reg R[] = +{ + {"pack", l_pack}, + {"unpack", l_unpack}, + {NULL, NULL} +}; + +LUALIB_API __attribute__((visibility("default"))) int luaopen_lpack(lua_State *L) +{ +#if LUA_VERSION_NUM < 502 + luaL_register(L, LUA_STRLIBNAME, R); +#else + luaL_newmetatable(L, LUA_STRLIBNAME); + luaL_newlib(L, R); +#endif + return 1; +} |