add XDPLua

.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/linux/netdevice.h

@@ -3772,6 +3772,10 @@ u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,
 		    enum bpf_netdev_command cmd);
 int xdp_umem_query(struct net_device *dev, u16 queue_id);
 
+#ifdef CONFIG_XDP_LUA
+int generic_xdp_lua_install_prog(char *lua_prog);
+#endif /* CONFIG_XDP_LUA */
+
 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
 bool is_skb_forwardable(const struct net_device *dev,

include/net/xdp.h

@@ -63,13 +63,33 @@ struct xdp_rxq_info {
 	struct xdp_mem_info mem;
 } ____cacheline_aligned; /* perf critical, avoid false-sharing */
 
+#ifdef CONFIG_XDP_LUA
+struct xdplua_create_work {
+	char				lua_script[8192];
+	struct lua_State	*L;
+	struct work_struct	work;
+	spinlock_t		lock;
+	bool			init;
+};
+
+DECLARE_PER_CPU(struct xdplua_create_work, luaworks);
+
+#define LUA_MAXINSNS 1e6
+
+#endif /* CONFIG_XDP_LUA */
+
+
 struct xdp_buff {
 	void *data;
 	void *data_end;
 	void *data_meta;
 	void *data_hard_start;
 	unsigned long handle;
 	struct xdp_rxq_info *rxq;
+#ifdef CONFIG_XDP_LUA
+	struct sk_buff *skb;
+	struct lua_State *L;
+#endif /* CONFIG_XDP_LUA */
 };
 
 struct xdp_frame {

include/uapi/linux/bpf.h

@@ -2890,6 +2890,106 @@ union bpf_attr {
  *		Obtain the 64bit jiffies
  *	Return
  *		The 64 bit jiffies
+ *
+ * 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(void *ctx, int data_ref)
+ *	Description
+ *		Releases the data-object reference, allowing it to be
+ *		garbage-collected	
+ *
+ * void bpf_lua_pcall(void *ctx, 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(void *ctx, int n)
+ *	Description
+ *		Pops n elements from the Lua stack
+ *
+ * void bpf_lua_pushinteger(void *ctx, int num)
+ *	Description
+ *		Pushes an integer with value n onto the Lua stack.
+ *
+ * void bpf_lua_pushlightuserdata(void *ctx, 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(void *ctx, 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 *ctx, void *map)
+ *	Description
+ *		Pushes a BPF map onto the Lua stack
+ *
+ * void bpf_lua_pushskb(void *ctx)
+ *	Description
+ *		Pushes an SKB structure onto the Lua stack
+ *
+ * void bpf_lua_pushstring(void *ctx, 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(void *ctx, 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(void *ctx, 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(void *ctx, 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
+ *
+ * void bpf_lua_type(void *ctx, 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),			\
@@ -3010,7 +3110,24 @@ union bpf_attr {
 	FN(probe_read_kernel_str),	\
 	FN(tcp_send_ack),		\
 	FN(send_signal_thread),		\
-	FN(jiffies64),
+	FN(jiffies64),	\
+	/* #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_newpacket),		\
+	FN(lua_tostring),		\
+	FN(lua_type),
+	/* #endif CONFIG_XDP_LUA */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

include/uapi/linux/if_link.h

@@ -984,6 +984,9 @@ enum {
 	IFLA_XDP_DRV_PROG_ID,
 	IFLA_XDP_SKB_PROG_ID,
 	IFLA_XDP_HW_PROG_ID,
+#ifdef CONFIG_XDP_LUA
+	IFLA_XDP_LUA_PROG,
+#endif /* CONFIG_XDP_LUA */
 	__IFLA_XDP_MAX,
 };
 

init/Kconfig

@@ -1307,6 +1307,12 @@ config HAVE_PCSPKR_PLATFORM
 config BPF
 	bool
 
+config LUNATIK
+	bool "Lunatik"
+	default n
+	help
+	  Support for the Lua interpreter
+
 menuconfig EXPERT
 	bool "Configure standard kernel features (expert users)"
 	# Unhide debug options, to make the on-by-default options visible

lib/Makefile

@@ -300,3 +300,11 @@ obj-$(CONFIG_OBJAGG) += objagg.o
 
 # KUnit tests
 obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
+subdir-ccflags-y += -I$(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/

net/core/Makefile

@@ -8,6 +8,10 @@ obj-y := sock.o request_sock.o skbuff.o datagram.o stream.o scm.o \
 
 obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
 
+CFLAGS_dev.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/
+CFLAGS_filter.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/ -Ilib/luaunpack/
 obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
 			neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
 			sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \

net/core/dev.c

@@ -68,6 +68,14 @@
  *				        - netif_rx() feedback
  */
 
+#ifdef CONFIG_XDP_LUA
+#include <lua.h>
+#include <lauxlib.h>
+#include <lstate.h>
+#include <lualib.h>
+#include <luadata.h>
+#endif /* CONFIG_XDP_LUA */
+
 #include <linux/uaccess.h>
 #include <linux/bitops.h>
 #include <linux/capability.h>
@@ -152,6 +160,9 @@
 
 static DEFINE_SPINLOCK(ptype_lock);
 static DEFINE_SPINLOCK(offload_lock);
+#ifdef CONFIG_XDP_LUA
+DEFINE_PER_CPU(struct xdplua_create_work, luaworks);
+#endif
 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 struct list_head ptype_all __read_mostly;	/* Taps */
 static struct list_head offload_base __read_mostly;
@@ -4512,6 +4523,9 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 	bool orig_bcast;
 	int hlen, off;
 	u32 mac_len;
+#ifdef CONFIG_XDP_LUA
+	struct xdplua_create_work *lw;
+#endif /* CONFIG_XDP_LUA */
 
 	/* Reinjected packets coming from act_mirred or similar should
 	 * not get XDP generic processing.
@@ -4556,9 +4570,22 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 
 	rxqueue = netif_get_rxqueue(skb);
 	xdp->rxq = &rxqueue->xdp_rxq;
+#ifdef CONFIG_XDP_LUA
+	lw = this_cpu_ptr(&luaworks);
+
+	xdp->skb = skb;
+	xdp->L = lw->L;
+#endif /* CONFIG_XDP_LUA */
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 
+#ifdef CONFIG_XDP_LUA
+	if (lw->init) {
+		lw->init = false;
+		spin_unlock(&lw->lock);
+	}
+#endif /* CONFIG_XDP_LUA */
+
 	/* check if bpf_xdp_adjust_head was used */
 	off = xdp->data - orig_data;
 	if (off) {
@@ -5366,6 +5393,50 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
 	return ret;
 }
 
+#ifdef CONFIG_XDP_LUA
+
+static void lstop(struct lua_State *L, struct lua_Debug *ar) {
+	luaL_error(L, "instruction limit exceeded");
+}
+
+static void per_cpu_xdp_lua_install(struct work_struct *w) {
+	int this_cpu = smp_processor_id();
+	struct xdplua_create_work *lw =
+		container_of(w, struct xdplua_create_work, work);
+
+	spin_lock_bh(&lw->lock);
+	if (luaL_loadstring(lw->L, lw->lua_script)) {
+		pr_err(KERN_INFO "Error on script loading: %s\nOn cpu: %d\n",
+			lua_tostring(lw->L, -1), this_cpu);
+		goto unlock;
+	}
+
+	lua_sethook(lw->L, lstop, LUA_MASKCOUNT, LUA_MAXINSNS);
+	if (lua_pcall(lw->L, 0, LUA_MULTRET, 0)) {
+		pr_err(KERN_INFO "Error on script execution: %s\nOn cpu: %d\n",
+			lua_tostring(lw->L, -1), this_cpu);
+	}
+
+	lua_sethook(lw->L, NULL, 0, 0);
+
+unlock:
+	spin_unlock_bh(&lw->lock);
+}
+
+int generic_xdp_lua_install_prog(char *lua_script)
+{
+	int cpu;
+	struct xdplua_create_work *lw;
+
+	for_each_possible_cpu(cpu) {
+		lw = per_cpu_ptr(&luaworks, cpu);
+		strcpy(lw->lua_script, lua_script);
+		schedule_work_on(cpu, &lw->work);
+	}
+	return 0;
+}
+#endif /* CONFIG_XDP_LUA */
+
 static int netif_receive_skb_internal(struct sk_buff *skb)
 {
 	int ret;
@@ -10487,6 +10558,9 @@ static int __init net_dev_init(void)
 	for_each_possible_cpu(i) {
 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
 		struct softnet_data *sd = &per_cpu(softnet_data, i);
+#ifdef CONFIG_XDP_LUA
+		struct xdplua_create_work *lw = per_cpu_ptr(&luaworks, i);
+#endif
 
 		INIT_WORK(flush, flush_backlog);
 
@@ -10506,6 +10580,19 @@ static int __init net_dev_init(void)
 		init_gro_hash(&sd->backlog);
 		sd->backlog.poll = process_backlog;
 		sd->backlog.weight = weight_p;
+#ifdef CONFIG_XDP_LUA
+		lw->L = luaL_newstate();
+		WARN_ON(!lw->L);
+
+		if (!lw->L)
+			continue;
+
+		luaL_openlibs(lw->L);
+		luaL_requiref(lw->L, "data", luaopen_data, 1);
+		lua_pop(lw->L, 1);
+
+		INIT_WORK(&lw->work, per_cpu_xdp_lua_install);
+#endif /* CONFIG_XDP_LUA */
 	}
 
 	dev_boot_phase = 0;