1 files changed, 149 insertions, 0 deletions
diff --git a/libs/luci-lib-nixio/src/bit.c b/libs/luci-lib-nixio/src/bit.c
new file mode 100644
index 000000000..1b352c51c
--- /dev/null
+++ b/libs/luci-lib-nixio/src/bit.c
@@ -0,0 +1,149 @@
+/*
+ * nixio - Linux I/O library for lua
+ *
+ *   Copyright (C) 2009 Steven Barth <steven@midlink.org>
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "nixio.h"
+#include <stdint.h>
+#include <stdlib.h>
+
+/* 52 bit maximum precision */
+#ifdef NIXIO_DOUBLE
+#define NIXIO_BIT_BMAX 52
+#define NIXIO_BIT_NMAX 0xfffffffffffff
+#else
+#define NIXIO_BIT_BMAX 32
+#define NIXIO_BIT_NMAX 0xffffffff
+#endif
+
+#define NIXIO_BIT_XOP(BIT_XOP)						\
+	uint64_t oper = nixio__checknumber(L, 1);		\
+	const int args = lua_gettop(L);					\
+													\
+	for (int i = 2; i <= args; i++) {				\
+		uint64_t oper2 = nixio__checknumber(L, i);	\
+		oper BIT_XOP oper2;							\
+	}												\
+													\
+	nixio__pushnumber(L, oper);						\
+	return 1;										\
+
+
+static int nixio_bit_or(lua_State *L) {
+	NIXIO_BIT_XOP(|=);
+}
+
+static int nixio_bit_and(lua_State *L) {
+	NIXIO_BIT_XOP(&=);
+}
+
+static int nixio_bit_xor(lua_State *L) {
+	NIXIO_BIT_XOP(^=);
+}
+
+static int nixio_bit_unset(lua_State *L) {
+	NIXIO_BIT_XOP(&= ~);
+}
+
+static int nixio_bit_not(lua_State *L) {
+	nixio__pushnumber(L,
+			(~((uint64_t)nixio__checknumber(L, 1))) & NIXIO_BIT_NMAX);
+	return 1;
+}
+
+static int nixio_bit_shl(lua_State *L) {
+	uint64_t oper = nixio__checknumber(L, 1);
+	oper <<= luaL_checkinteger(L, 2);
+	if (oper > NIXIO_BIT_NMAX) {
+		return luaL_error(L, "arithmetic overflow");
+	} else {
+		nixio__pushnumber(L, oper);
+		return 1;
+	}
+}
+
+static int nixio_bit_ashr(lua_State *L) {
+	int64_t oper = nixio__checknumber(L, 1);
+	nixio__pushnumber(L, oper >> luaL_checkinteger(L, 2));
+	return 1;
+}
+
+static int nixio_bit_shr(lua_State *L) {
+	uint64_t oper = nixio__checknumber(L, 1);
+	nixio__pushnumber(L, oper >> luaL_checkinteger(L, 2));
+	return 1;
+}
+
+static int nixio_bit_div(lua_State *L) {
+	uint64_t oper = luaL_checknumber(L, 1);
+	const int args = lua_gettop(L);
+
+	for (int i = 2; i <= args; i++) {
+		uint64_t oper2 = nixio__checknumber(L, i);
+		oper /= oper2;
+	}
+
+	nixio__pushnumber(L, oper);
+	return 1;
+}
+
+static int nixio_bit_check(lua_State *L) {
+	uint64_t oper  = nixio__checknumber(L, 1);
+	uint64_t oper2 = nixio__checknumber(L, 2);
+	lua_pushboolean(L, (oper & oper2) == oper2);
+	return 1;
+}
+
+static int nixio_bit_cast(lua_State *L) {
+	nixio__pushnumber(L, ((uint64_t)nixio__checknumber(L, 1)) & NIXIO_BIT_NMAX);
+	return 1;
+}
+
+static int nixio_bit_swap(lua_State *L) {
+	uint64_t op = nixio__checknumber(L, 1);
+	op = (op >> 24) | ((op >> 8) & 0xff00) | ((op & 0xff00) << 8) | (op << 24);
+	nixio__pushnumber(L, op);
+	return 1;
+}
+
+/* module table */
+static const luaL_reg R[] = {
+	{"bor",			nixio_bit_or},
+	{"set",			nixio_bit_or},
+	{"band",		nixio_bit_and},
+	{"bxor",		nixio_bit_xor},
+	{"unset",		nixio_bit_unset},
+	{"bnot",		nixio_bit_not},
+	{"rshift",		nixio_bit_shr},
+	{"arshift",		nixio_bit_ashr},
+	{"lshift",		nixio_bit_shl},
+	{"div",			nixio_bit_div},
+	{"check",		nixio_bit_check},
+	{"cast",		nixio_bit_cast},
+	{"tobit",		nixio_bit_cast},
+	{"bswap",		nixio_bit_swap},
+	{NULL,			NULL}
+};
+
+void nixio_open_bit(lua_State *L) {
+	lua_newtable(L);
+	luaL_register(L, NULL, R);
+	nixio__pushnumber(L, NIXIO_BIT_BMAX);
+	lua_setfield(L, -2, "bits");
+	nixio__pushnumber(L, NIXIO_BIT_NMAX);
+	lua_setfield(L, -2, "max");
+	lua_setfield(L, -2, "bit");
+}