add LuaData submodule

Author: VictorNogueiraRio

.gitmodules

@@ -1,3 +1,6 @@
 [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

include/uapi/linux/bpf.h

@@ -2891,6 +2891,20 @@ union bpf_attr {
  *	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
@@ -3079,6 +3093,8 @@ union bpf_attr {
 	FN(send_signal_thread),		\
 	FN(jiffies64),	\
 	/* #ifdef CONFIG_XDP_LUA */	\
+	FN(lua_dataref),		\
+	FN(lua_dataunref),		\
 	FN(lua_pcall),			\
 	FN(lua_pop),			\
 	FN(lua_pushinteger),		\

lib/Makefile

@@ -301,5 +301,7 @@ 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/ \
 	            -D_KERNEL
 obj-$(CONFIG_LUNATIK) += lunatik/
+obj-$(CONFIG_LUADATA) += luadata/

lib/luadata

@@ -8,8 +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
-CFLAGS_filter.o = -Ilib/lunatik/lua/ -D_KERNEL
+CFLAGS_dev.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/
+CFLAGS_filter.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/
 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/Makefile

@@ -72,6 +72,7 @@
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
+#include <luadata.h>
 #endif /* CONFIG_XDP_LUA */
 
 #include <linux/uaccess.h>
@@ -10555,6 +10556,7 @@ static int __init net_dev_init(void)
 		}
 
 		luaL_openlibs(new_state_cpu->L);
+		luaL_requiref(new_state_cpu->L, "data", luaopen_data, 1);
 		lua_pop(new_state_cpu->L, 1);
 		new_state_cpu->cpu = i;
 

net/core/dev.c

@@ -76,6 +76,7 @@
 
 #ifdef CONFIG_XDP_LUA
 #include <lua.h>
+#include <luadata.h>
 #endif /* CONFIG_XDP_LUA */
 
 /**
@@ -5854,6 +5855,41 @@ static const struct bpf_func_proto bpf_tcp_gen_syncookie_proto = {
 #endif /* CONFIG_INET */
 
 #ifdef CONFIG_XDP_LUA
+BPF_CALL_2(bpf_lua_dataref, struct xdp_buff *, ctx, int, offset) {
+	if (offset + ctx->data < ctx->data_end) {
+		int data_ref;
+
+		data_ref = ldata_newref(ctx->L, ctx->data + offset,
+				ctx->data_end - ctx->data - offset);
+		return data_ref;
+	}
+
+	return -1;
+}
+
+static const struct bpf_func_proto bpf_lua_dataref_proto = {
+	.func		= bpf_lua_dataref,
+	.gpl_only	= false,
+	.pkt_access	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg1_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_lua_dataunref, struct xdp_buff *, ctx, int, data_ref) {
+	ldata_unref(ctx->L, data_ref);
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_lua_dataunref_proto = {
+	.func		= bpf_lua_dataunref,
+	.gpl_only	= false,
+	.pkt_access	= false,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+};
+
 BPF_CALL_4(bpf_lua_pcall, struct xdp_buff *, ctx, char *, funcname,
 			int, num_args, int, num_rets) {
 	if (lua_getglobal(ctx->L, funcname) != LUA_TFUNCTION) {
@@ -6105,6 +6141,10 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 	case BPF_FUNC_jiffies64:
 		return &bpf_jiffies64_proto;
 #ifdef CONFIG_XDP_LUA
+	case BPF_FUNC_lua_dataref:
+		return &bpf_lua_dataref_proto;
+	case BPF_FUNC_lua_dataunref:
+		return &bpf_lua_dataunref_proto;
 	case BPF_FUNC_lua_pcall:
 		return &bpf_lua_pcall_proto;
 	case BPF_FUNC_lua_pop:

net/core/filter.c

@@ -2891,6 +2891,20 @@ union bpf_attr {
  *	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
@@ -3079,6 +3093,8 @@ union bpf_attr {
 	FN(send_signal_thread),		\
 	FN(jiffies64),	\
 	/* #ifdef CONFIG_XDP_LUA */	\
+	FN(lua_dataref),		\
+	FN(lua_dataunref),		\
 	FN(lua_pcall),			\
 	FN(lua_pop),			\
 	FN(lua_pushinteger),		\