From eb7c36d72c04628aacea18c79dc95e87fc1a7581 Mon Sep 17 00:00:00 2001 From: wolfy852 Date: Sat, 16 Jan 2016 19:31:36 -0600 Subject: [PATCH] Reimplement I/O library Note: I/O library is fully functioning in this state, but lacks security restrictions. We'll get to those later ;) --- src/blua/Makefile.cfg | 1 + src/blua/linit.c | 1 + src/blua/liolib.c | 553 ++++++++++++++++++++++++++++++++++++++++++ src/blua/lualib.h | 3 + 4 files changed, 558 insertions(+) create mode 100644 src/blua/liolib.c diff --git a/src/blua/Makefile.cfg b/src/blua/Makefile.cfg index e3fb3df4..895f9362 100644 --- a/src/blua/Makefile.cfg +++ b/src/blua/Makefile.cfg @@ -18,6 +18,7 @@ OBJS:=$(OBJS) \ $(OBJDIR)/ldo.o \ $(OBJDIR)/lfunc.o \ $(OBJDIR)/linit.o \ + $(OBJDIR)/liolib.o \ $(OBJDIR)/llex.o \ $(OBJDIR)/lmem.o \ $(OBJDIR)/lobject.o \ diff --git a/src/blua/linit.c b/src/blua/linit.c index 52b02dbe..d17390b2 100644 --- a/src/blua/linit.c +++ b/src/blua/linit.c @@ -17,6 +17,7 @@ static const luaL_Reg lualibs[] = { {"", luaopen_base}, {LUA_TABLIBNAME, luaopen_table}, + {LUA_IOLIBNAME, luaopen_io}, {LUA_STRLIBNAME, luaopen_string}, {NULL, NULL} }; diff --git a/src/blua/liolib.c b/src/blua/liolib.c new file mode 100644 index 00000000..e79ed1cb --- /dev/null +++ b/src/blua/liolib.c @@ -0,0 +1,553 @@ +/* +** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 roberto Exp $ +** Standard I/O (and system) library +** See Copyright Notice in lua.h +*/ + + +#include +#include +#include +#include + +#define liolib_c +#define LUA_LIB + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + + +#define IO_INPUT 1 +#define IO_OUTPUT 2 + + +static const char *const fnames[] = {"input", "output"}; + + +static int pushresult (lua_State *L, int i, const char *filename) { + int en = errno; /* calls to Lua API may change this value */ + if (i) { + lua_pushboolean(L, 1); + return 1; + } + else { + lua_pushnil(L); + if (filename) + lua_pushfstring(L, "%s: %s", filename, strerror(en)); + else + lua_pushfstring(L, "%s", strerror(en)); + lua_pushinteger(L, en); + return 3; + } +} + + +static void fileerror (lua_State *L, int arg, const char *filename) { + lua_pushfstring(L, "%s: %s", filename, strerror(errno)); + luaL_argerror(L, arg, lua_tostring(L, -1)); +} + + +#define tofilep(L) ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE)) + + +static int io_type (lua_State *L) { + void *ud; + luaL_checkany(L, 1); + ud = lua_touserdata(L, 1); + lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE); + if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1)) + lua_pushnil(L); /* not a file */ + else if (*((FILE **)ud) == NULL) + lua_pushliteral(L, "closed file"); + else + lua_pushliteral(L, "file"); + return 1; +} + + +static FILE *tofile (lua_State *L) { + FILE **f = tofilep(L); + if (*f == NULL) + luaL_error(L, "attempt to use a closed file"); + return *f; +} + + + +/* +** When creating file handles, always creates a `closed' file handle +** before opening the actual file; so, if there is a memory error, the +** file is not left opened. +*/ +static FILE **newfile (lua_State *L) { + FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *)); + *pf = NULL; /* file handle is currently `closed' */ + luaL_getmetatable(L, LUA_FILEHANDLE); + lua_setmetatable(L, -2); + return pf; +} + + +/* +** function to (not) close the standard files stdin, stdout, and stderr +*/ +static int io_noclose (lua_State *L) { + lua_pushnil(L); + lua_pushliteral(L, "cannot close standard file"); + return 2; +} + + +/* +** function to close 'popen' files +*/ +static int io_pclose (lua_State *L) { + FILE **p = tofilep(L); + int ok = lua_pclose(L, *p); + *p = NULL; + return pushresult(L, ok, NULL); +} + + +/* +** function to close regular files +*/ +static int io_fclose (lua_State *L) { + FILE **p = tofilep(L); + int ok = (fclose(*p) == 0); + *p = NULL; + return pushresult(L, ok, NULL); +} + + +static int aux_close (lua_State *L) { + lua_getfenv(L, 1); + lua_getfield(L, -1, "__close"); + return (lua_tocfunction(L, -1))(L); +} + + +static int io_close (lua_State *L) { + if (lua_isnone(L, 1)) + lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT); + tofile(L); /* make sure argument is a file */ + return aux_close(L); +} + + +static int io_gc (lua_State *L) { + FILE *f = *tofilep(L); + /* ignore closed files */ + if (f != NULL) + aux_close(L); + return 0; +} + + +static int io_tostring (lua_State *L) { + FILE *f = *tofilep(L); + if (f == NULL) + lua_pushliteral(L, "file (closed)"); + else + lua_pushfstring(L, "file (%p)", f); + return 1; +} + + +static int io_open (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + FILE **pf = newfile(L); + *pf = fopen(filename, mode); + return (*pf == NULL) ? pushresult(L, 0, filename) : 1; +} + + +/* +** this function has a separated environment, which defines the +** correct __close for 'popen' files +*/ +static int io_popen (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + FILE **pf = newfile(L); + *pf = lua_popen(L, filename, mode); + return (*pf == NULL) ? pushresult(L, 0, filename) : 1; +} + + +static int io_tmpfile (lua_State *L) { + FILE **pf = newfile(L); + *pf = tmpfile(); + return (*pf == NULL) ? pushresult(L, 0, NULL) : 1; +} + + +static FILE *getiofile (lua_State *L, int findex) { + FILE *f; + lua_rawgeti(L, LUA_ENVIRONINDEX, findex); + f = *(FILE **)lua_touserdata(L, -1); + if (f == NULL) + luaL_error(L, "standard %s file is closed", fnames[findex - 1]); + return f; +} + + +static int g_iofile (lua_State *L, int f, const char *mode) { + if (!lua_isnoneornil(L, 1)) { + const char *filename = lua_tostring(L, 1); + if (filename) { + FILE **pf = newfile(L); + *pf = fopen(filename, mode); + if (*pf == NULL) + fileerror(L, 1, filename); + } + else { + tofile(L); /* check that it's a valid file handle */ + lua_pushvalue(L, 1); + } + lua_rawseti(L, LUA_ENVIRONINDEX, f); + } + /* return current value */ + lua_rawgeti(L, LUA_ENVIRONINDEX, f); + return 1; +} + + +static int io_input (lua_State *L) { + return g_iofile(L, IO_INPUT, "r"); +} + + +static int io_output (lua_State *L) { + return g_iofile(L, IO_OUTPUT, "w"); +} + + +static int io_readline (lua_State *L); + + +static void aux_lines (lua_State *L, int idx, int toclose) { + lua_pushvalue(L, idx); + lua_pushboolean(L, toclose); /* close/not close file when finished */ + lua_pushcclosure(L, io_readline, 2); +} + + +static int f_lines (lua_State *L) { + tofile(L); /* check that it's a valid file handle */ + aux_lines(L, 1, 0); + return 1; +} + + +static int io_lines (lua_State *L) { + if (lua_isnoneornil(L, 1)) { /* no arguments? */ + /* will iterate over default input */ + lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT); + return f_lines(L); + } + else { + const char *filename = luaL_checkstring(L, 1); + FILE **pf = newfile(L); + *pf = fopen(filename, "r"); + if (*pf == NULL) + fileerror(L, 1, filename); + aux_lines(L, lua_gettop(L), 1); + return 1; + } +} + + +/* +** {====================================================== +** READ +** ======================================================= +*/ + + +static int read_number (lua_State *L, FILE *f) { + lua_Number d; + if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) { + lua_pushnumber(L, d); + return 1; + } + else return 0; /* read fails */ +} + + +static int test_eof (lua_State *L, FILE *f) { + int c = getc(f); + ungetc(c, f); + lua_pushlstring(L, NULL, 0); + return (c != EOF); +} + + +static int read_line (lua_State *L, FILE *f) { + luaL_Buffer b; + luaL_buffinit(L, &b); + for (;;) { + size_t l; + char *p = luaL_prepbuffer(&b); + if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */ + luaL_pushresult(&b); /* close buffer */ + return (lua_objlen(L, -1) > 0); /* check whether read something */ + } + l = strlen(p); + if (l == 0 || p[l-1] != '\n') + luaL_addsize(&b, l); + else { + luaL_addsize(&b, l - 1); /* do not include `eol' */ + luaL_pushresult(&b); /* close buffer */ + return 1; /* read at least an `eol' */ + } + } +} + + +static int read_chars (lua_State *L, FILE *f, size_t n) { + size_t rlen; /* how much to read */ + size_t nr; /* number of chars actually read */ + luaL_Buffer b; + luaL_buffinit(L, &b); + rlen = LUAL_BUFFERSIZE; /* try to read that much each time */ + do { + char *p = luaL_prepbuffer(&b); + if (rlen > n) rlen = n; /* cannot read more than asked */ + nr = fread(p, sizeof(char), rlen, f); + luaL_addsize(&b, nr); + n -= nr; /* still have to read `n' chars */ + } while (n > 0 && nr == rlen); /* until end of count or eof */ + luaL_pushresult(&b); /* close buffer */ + return (n == 0 || lua_objlen(L, -1) > 0); +} + + +static int g_read (lua_State *L, FILE *f, int first) { + int nargs = lua_gettop(L) - 1; + int success; + int n; + clearerr(f); + if (nargs == 0) { /* no arguments? */ + success = read_line(L, f); + n = first+1; /* to return 1 result */ + } + else { /* ensure stack space for all results and for auxlib's buffer */ + luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); + success = 1; + for (n = first; nargs-- && success; n++) { + if (lua_type(L, n) == LUA_TNUMBER) { + size_t l = (size_t)lua_tointeger(L, n); + success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); + } + else { + const char *p = lua_tostring(L, n); + luaL_argcheck(L, p && p[0] == '*', n, "invalid option"); + switch (p[1]) { + case 'n': /* number */ + success = read_number(L, f); + break; + case 'l': /* line */ + success = read_line(L, f); + break; + case 'a': /* file */ + read_chars(L, f, ~((size_t)0)); /* read MAX_SIZE_T chars */ + success = 1; /* always success */ + break; + default: + return luaL_argerror(L, n, "invalid format"); + } + } + } + } + if (ferror(f)) + return pushresult(L, 0, NULL); + if (!success) { + lua_pop(L, 1); /* remove last result */ + lua_pushnil(L); /* push nil instead */ + } + return n - first; +} + + +static int io_read (lua_State *L) { + return g_read(L, getiofile(L, IO_INPUT), 1); +} + + +static int f_read (lua_State *L) { + return g_read(L, tofile(L), 2); +} + + +static int io_readline (lua_State *L) { + FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1)); + int sucess; + if (f == NULL) /* file is already closed? */ + luaL_error(L, "file is already closed"); + sucess = read_line(L, f); + if (ferror(f)) + return luaL_error(L, "%s", strerror(errno)); + if (sucess) return 1; + else { /* EOF */ + if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */ + lua_settop(L, 0); + lua_pushvalue(L, lua_upvalueindex(1)); + aux_close(L); /* close it */ + } + return 0; + } +} + +/* }====================================================== */ + + +static int g_write (lua_State *L, FILE *f, int arg) { + int nargs = lua_gettop(L) - 1; + int status = 1; + for (; nargs--; arg++) { + if (lua_type(L, arg) == LUA_TNUMBER) { + /* optimization: could be done exactly as for strings */ + status = status && + fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0; + } + else { + size_t l; + const char *s = luaL_checklstring(L, arg, &l); + status = status && (fwrite(s, sizeof(char), l, f) == l); + } + } + return pushresult(L, status, NULL); +} + + +static int io_write (lua_State *L) { + return g_write(L, getiofile(L, IO_OUTPUT), 1); +} + + +static int f_write (lua_State *L) { + return g_write(L, tofile(L), 2); +} + + +static int f_seek (lua_State *L) { + static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; + static const char *const modenames[] = {"set", "cur", "end", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, "cur", modenames); + long offset = luaL_optlong(L, 3, 0); + op = fseek(f, offset, mode[op]); + if (op) + return pushresult(L, 0, NULL); /* error */ + else { + lua_pushinteger(L, ftell(f)); + return 1; + } +} + + +static int f_setvbuf (lua_State *L) { + static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; + static const char *const modenames[] = {"no", "full", "line", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, NULL, modenames); + lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); + int res = setvbuf(f, NULL, mode[op], sz); + return pushresult(L, res == 0, NULL); +} + + + +static int io_flush (lua_State *L) { + return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); +} + + +static int f_flush (lua_State *L) { + return pushresult(L, fflush(tofile(L)) == 0, NULL); +} + + +static const luaL_Reg iolib[] = { + {"close", io_close}, + {"flush", io_flush}, + {"input", io_input}, + {"lines", io_lines}, + {"open", io_open}, + {"output", io_output}, + {"popen", io_popen}, + {"read", io_read}, + {"tmpfile", io_tmpfile}, + {"type", io_type}, + {"write", io_write}, + {NULL, NULL} +}; + + +static const luaL_Reg flib[] = { + {"close", io_close}, + {"flush", f_flush}, + {"lines", f_lines}, + {"read", f_read}, + {"seek", f_seek}, + {"setvbuf", f_setvbuf}, + {"write", f_write}, + {"__gc", io_gc}, + {"__tostring", io_tostring}, + {NULL, NULL} +}; + + +static void createmeta (lua_State *L) { + luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */ + lua_pushvalue(L, -1); /* push metatable */ + lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */ + luaL_register(L, NULL, flib); /* file methods */ +} + + +static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) { + *newfile(L) = f; + if (k > 0) { + lua_pushvalue(L, -1); + lua_rawseti(L, LUA_ENVIRONINDEX, k); + } + lua_pushvalue(L, -2); /* copy environment */ + lua_setfenv(L, -2); /* set it */ + lua_setfield(L, -3, fname); +} + + +static void newfenv (lua_State *L, lua_CFunction cls) { + lua_createtable(L, 0, 1); + lua_pushcfunction(L, cls); + lua_setfield(L, -2, "__close"); +} + + +LUALIB_API int luaopen_io (lua_State *L) { + createmeta(L); + /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */ + newfenv(L, io_fclose); + lua_replace(L, LUA_ENVIRONINDEX); + /* open library */ + luaL_register(L, LUA_IOLIBNAME, iolib); + /* create (and set) default files */ + newfenv(L, io_noclose); /* close function for default files */ + createstdfile(L, stdin, IO_INPUT, "stdin"); + createstdfile(L, stdout, IO_OUTPUT, "stdout"); + createstdfile(L, stderr, 0, "stderr"); + lua_pop(L, 1); /* pop environment for default files */ + lua_getfield(L, -1, "popen"); + newfenv(L, io_pclose); /* create environment for 'popen' */ + lua_setfenv(L, -2); /* set fenv for 'popen' */ + lua_pop(L, 1); /* pop 'popen' */ + return 1; +} + diff --git a/src/blua/lualib.h b/src/blua/lualib.h index 6ebe2728..4ea97edf 100644 --- a/src/blua/lualib.h +++ b/src/blua/lualib.h @@ -21,6 +21,9 @@ LUALIB_API int (luaopen_base) (lua_State *L); #define LUA_TABLIBNAME "table" LUALIB_API int (luaopen_table) (lua_State *L); +#define LUA_IOLIBNAME "io" +LUALIB_API int (luaopen_io) (lua_State *L); + #define LUA_STRLIBNAME "string" LUALIB_API int (luaopen_string) (lua_State *L);