Add XDPLua

Author: VictorNogueiraRio

.gitmodules

@@ -0,0 +1,15 @@
+[submodule "lib/lunatik"]
+	path = lib/lunatik
+	url = https://github.com/luainkernel/lunatik.git
+[submodule "lib/luadata"]
+	path = lib/luadata
+	url = https://github.com/luainkernel/luadata
+[submodule "lib/luaxdp"]
+	path = lib/luaxdp
+	url = https://github.com/luainkernel/luaxdp.git
+[submodule "lib/luarcu"]
+	path = lib/luarcu
+	url = https://github.com/luainkernel/luarcu
+[submodule "lib/luaunpack"]
+	path = lib/luaunpack
+	url = https://github.com/VictorNogueiraRio/luaunpack.git

include/net/xdplua.h

@@ -0,0 +1,79 @@
+/* XDPLua internal functions
+ * Copyright (C) 2021 Victor Nogueira <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __LINUX_NET_XDP_LUA_H__
+#define __LINUX_NET_XDP_LUA_H__
+
+#include <lua.h>
+
+#include <linux/skbuff.h>
+#include <linux/workqueue.h>
+#include <uapi/linux/if_link.h>
+#include <linux/filter.h>
+
+struct xdp_lua_work {
+	char				script[XDP_LUA_MAX_SCRIPT_LEN];
+	size_t				script_len;
+	struct lua_State	*L;
+	struct sk_buff		*skb;
+	struct work_struct	work;
+};
+
+DECLARE_PER_CPU(struct xdp_lua_work, luaworks);
+
+
+#define XDP_LUA_BPF_FUNC(name)	BPF_FUNC_lua_##name
+
+#define xdp_lua_get_skb() 		(this_cpu_ptr(&luaworks)->skb)
+#define xdp_lua_set_skb(skb) 	(this_cpu_ptr(&luaworks)->skb = skb)
+
+int generic_xdp_lua_install_prog(const char *script, size_t script_len);
+void xdp_lua_init(void);
+
+#define __BPF_LUA_MAP_0(l, m, v, ...) l
+#define __BPF_LUA_MAP_1(l, m, v, t, a, ...) l, __BPF_MAP_1(m, v, t, a, __VA_ARGS__)
+#define __BPF_LUA_MAP_2(l, m, v, t, a, ...) l, __BPF_MAP_2(m, v, t, a, __VA_ARGS__)
+#define __BPF_LUA_MAP_3(l, m, v, t, a, ...) l, __BPF_MAP_3(m, v, t, a, __VA_ARGS__)
+#define __BPF_LUA_MAP_4(l, m, v, t, a, ...) l, __BPF_MAP_4(m, v, t, a, __VA_ARGS__)
+#define __BPF_LUA_MAP_5(l, m, v, t, a, ...) l, __BPF_MAP_5(m, v, t, a, __VA_ARGS__)
+
+#define __BPF_LUA_MAP(n, l, ...) __BPF_LUA_MAP_##n(l, __VA_ARGS__)
+
+#define LST_TYPE	lua_State
+#define LST_NAME	L
+#define LST_DECL	__BPF_DECL_ARGS(LST_TYPE*, LST_NAME)
+
+#define BPF_LUA_CALL_x(x, name, ...)					\
+	static __always_inline						       \
+	u64 ____##name(__BPF_LUA_MAP(x, LST_DECL, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \
+	u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));	       \
+	u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))	       \
+	{								       \
+		int ret = -ENOENT;					\
+		lua_State *L = this_cpu_ptr(&luaworks)->L;		\
+		WARN_ON(!L);							\
+		if (!L)								\
+			return ret;						\
+		ret = ____##name(__BPF_LUA_MAP(x, LST_NAME, __BPF_CAST, __BPF_N, __VA_ARGS__));	\
+		return ret;								\
+	}								       \
+	static __always_inline						       \
+	u64 ____##name(__BPF_LUA_MAP(x, LST_DECL, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
+
+#define BPF_LUA_CALL_0(name, ...)	BPF_LUA_CALL_x(0, name, __VA_ARGS__)
+#define BPF_LUA_CALL_1(name, ...)	BPF_LUA_CALL_x(1, name, __VA_ARGS__)
+#define BPF_LUA_CALL_2(name, ...)	BPF_LUA_CALL_x(2, name, __VA_ARGS__)
+#define BPF_LUA_CALL_3(name, ...)	BPF_LUA_CALL_x(3, name, __VA_ARGS__)
+#define BPF_LUA_CALL_4(name, ...)	BPF_LUA_CALL_x(4, name, __VA_ARGS__)
+#define BPF_LUA_CALL_5(name, ...)	BPF_LUA_CALL_x(5, name, __VA_ARGS__)
+
+#endif /* __LINUX_NET_XDP_LUA_H__ */

include/uapi/linux/bpf.h

@@ -3742,6 +3742,111 @@ union bpf_attr {
  * 	Return
  * 		The helper returns **TC_ACT_REDIRECT** on success or
  * 		**TC_ACT_SHOT** on error.
+ *
+ * int bpf_lua_dataref(void *ctx, int offset)
+ *	Description
+ *		Create a new lua data buffer object pointing to the captured
+ *		packet at the specified offset. The function leaves the new
+ *		object on top of the Lua stack.
+ *	Return
+ *		Data object reference number on success, or -1 in case
+ *		of failure
+ *
+ * void bpf_lua_dataunref(int data_ref)
+ *	Description
+ *		Releases the data-object reference, allowing it to be
+ *		garbage-collected
+ *
+ * int bpf_lua_pcall(char *funcname, int num_args, int num_rets)
+ *	Description
+ *		Calls Lua function funcname with the given nargs arguments in protected mode
+ *
+ * void bpf_lua_pop(int n)
+ *	Description
+ *		Pops n elements from the Lua stack
+ *
+ * void bpf_lua_pushinteger(int num)
+ *	Description
+ *		Pushes an integer with value n onto the Lua stack.
+ *
+ * void bpf_lua_pushlightuserdata(void *ptr)
+ *	Description
+ *		Pushes a light userdata onto the Lua stack.
+ *		Userdata represent C values in Lua.
+ *		A light userdata represents a pointer, a void*.
+ *		It is a value (like a number): you do not create it,
+ *		it has no individual metatable, and it is not collected
+ *		(as it was never created).
+ *		A light userdata is equal to "any" light userdata with
+ *		the same C address.
+ *
+ * void bpf_lua_pushlstring(const char *s, size_t len)
+ *	Description
+ *		Pushes the string pointed to by s with size len onto the stack.
+ *		Lua makes (or reuses) an internal copy of the given string,
+ *		so the memory at s can be freed or reused immediately after the
+ *		function returns.
+ *		The string can contain any binary data, including embedded zeros.
+ *
+ * void bpf_lua_pushmap(void *map)
+ *	Description
+ *		Pushes a BPF map onto the Lua stack
+ *
+ * void bpf_lua_pushskb(void)
+ *	Description
+ *		Pushes an SKB structure onto the Lua stack
+ *
+ * void bpf_lua_pushstring(const char *s)
+ *	Description
+ *		Pushes the zero-terminated string pointed to by s onto the stack.
+ *		Lua makes (or reuses) an internal copy of the given string,
+ *		so the memory at s can be freed or reused immediately after the
+ *		function returns.
+ *
+ * int bpf_lua_toboolean(int index)
+ *	Description
+ *		Converts the Lua value at the given index to a C
+ *		boolean value (0 or 1)
+ *	Return
+ *		1 if the value in the given index of the Lua stack is
+ *		different from from false or null, otherwise returns 0
+ *
+ * int bpf_lua_tointeger(int index)
+ *	Description
+ *		Converts the Lua value at the given index of the Lua stack
+ *		to the signed integral type lua_Integer.
+ *	Return
+ *		The converted Lua value at the given index, if the value is
+ *		convertible to an integer(see the Lua manual for more details
+ *		on type conversion); otherwise returns 0
+ *
+ * void bpf_lua_tostring(const char *str, u32 size, int index)
+ *	Description
+ *		Converts the Lua value at the given index of the Lua
+ *		stack to a C string and copies size bytes of it to
+ *		value pointed by str
+ *	Return
+ *		1 if the value at the given index of the Lua stack is a
+ *		string; otherwise it returns 0
+ *
+ * int bpf_lua_newpacket(void *ctx, int offset)
+ *	Description
+ *		Create new luaunpack user data buffer pointing to
+ *		the captured packet at the specified offset
+ *
+ * int bpf_lua_type(int index)
+ *	Description
+ *		Obtains the type of the Lua value at the given index
+ *		of the Lua stack
+ *
+ *	Return
+ *		Type of the value in the given valid index,
+ *		or LUA_TNONE for a non-valid (but acceptable) index.
+ *		The types returned by lua_type are coded by the
+ *		following constants defined in lua.h: LUA_TNIL (0),
+ *		LUA_TNUMBER, LUA_TBOOLEAN, LUA_TSTRING, LUA_TTABLE,
+ *		LUA_TFUNCTION, LUA_TUSERDATA, LUA_TTHREAD, and
+ *		LUA_TLIGHTUSERDATA.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3900,6 +4005,23 @@ union bpf_attr {
 	FN(per_cpu_ptr),		\
 	FN(this_cpu_ptr),		\
 	FN(redirect_peer),		\
+	/* #ifdef CONFIG_XDP_LUA */	\
+	FN(lua_dataref),		\
+	FN(lua_dataunref),		\
+	FN(lua_pcall),			\
+	FN(lua_pop),			\
+	FN(lua_pushinteger),		\
+	FN(lua_pushlightuserdata),	\
+	FN(lua_pushlstring),		\
+	FN(lua_pushmap),		\
+	FN(lua_pushskb),		\
+	FN(lua_pushstring),		\
+	FN(lua_toboolean),		\
+	FN(lua_tointeger),		\
+	FN(lua_tostring),		\
+	FN(lua_newpacket),		\
+	FN(lua_type),
+	/* #endif CONFIG_XDP_LUA */
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

include/uapi/linux/if_link.h

@@ -1172,6 +1172,7 @@ enum {
 #define XDP_FLAGS_MASK			(XDP_FLAGS_UPDATE_IF_NOEXIST | \
 					 XDP_FLAGS_MODES | XDP_FLAGS_REPLACE)
 
+#define XDP_LUA_MAX_SCRIPT_LEN			8192
 /* These are stored into IFLA_XDP_ATTACHED on dump. */
 enum {
 	XDP_ATTACHED_NONE = 0,
@@ -1191,6 +1192,7 @@ enum {
 	IFLA_XDP_SKB_PROG_ID,
 	IFLA_XDP_HW_PROG_ID,
 	IFLA_XDP_EXPECTED_FD,
+	IFLA_XDP_LUA_PROG,
 	__IFLA_XDP_MAX,
 };
 

lib/Makefile

@@ -353,3 +353,12 @@ obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o
 obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
 obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
 obj-$(CONFIG_BITS_TEST) += test_bits.o
+
+subdir-ccflags-y += -I$(srctree)/lib/lunatik/lua \
+	            -I$(srctree)/lib/luadata/ -I$(srctree)/lib/luaunpack/ \
+	            -D_KERNEL
+obj-$(CONFIG_LUNATIK) += lunatik/
+obj-$(CONFIG_LUADATA) += luadata/
+obj-$(CONFIG_LUAXDP) += luaxdp/
+obj-$(CONFIG_LUARCU) += luarcu/
+obj-$(CONFIG_LUAUNPACK) += luaunpack/