add LuaUnpack submodule

Author: VictorNogueiraRio

.gitmodules

@@ -10,3 +10,6 @@
 [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/uapi/linux/bpf.h

@@ -3100,7 +3100,8 @@ union bpf_attr {
 	FN(lua_pushskb),		\
 	FN(lua_pushstring),		\
 	FN(lua_toboolean),		\
-	FN(lua_tointeger),
+	FN(lua_tointeger),		\
+	FN(lua_newpacket),
 	/* #endif CONFIG_XDP_LUA */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

lib/Makefile

@@ -301,9 +301,10 @@ 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$(srctree)/lib/luadata/ -I$(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/

lib/luaunpack

@@ -11,7 +11,7 @@ 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/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/Makefile

@@ -77,6 +77,7 @@
 #ifdef CONFIG_XDP_LUA
 #include <lua.h>
 #include <luadata.h>
+#include <luaunpack.h>
 #endif /* CONFIG_XDP_LUA */
 
 /**
@@ -6073,6 +6074,24 @@ static const struct bpf_func_proto bpf_lua_tointeger_proto = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 	.arg2_type	= ARG_ANYTHING,
 };
+
+BPF_CALL_2(bpf_lua_newpacket, struct xdp_buff *, ctx, int, offset) {
+	if (offset + ctx->data < ctx->data_end) {
+		return lunpack_newpacket(ctx->L, ctx->data + offset,
+				ctx->data_end - ctx->data - offset);
+	}
+
+	return -EINVAL;
+}
+
+static const struct bpf_func_proto bpf_lua_newpacket_proto = {
+	.func		= bpf_lua_newpacket,
+	.gpl_only	= false,
+	.pkt_access	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+};
 #endif /* CONFIG_XDP_LUA */
 
 bool bpf_helper_changes_pkt_data(void *func)
@@ -6176,6 +6195,8 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 		return &bpf_lua_toboolean_proto;
 	case BPF_FUNC_lua_tointeger:
 		return &bpf_lua_tointeger_proto;
+	case BPF_FUNC_lua_newpacket:
+		return &bpf_lua_newpacket_proto;
 #endif /* CONFIG_XDP_LUA */
 	default:
 		return NULL;

net/core/filter.c

@@ -2967,6 +2967,11 @@ union bpf_attr {
  *		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_newpacket(void *ctx, int offset)
+ *	Description
+ *		Create new luaunpack user data buffer pointing to
+ *		the captured packet at the specified offset
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3100,7 +3105,8 @@ union bpf_attr {
 	FN(lua_pushskb),		\
 	FN(lua_pushstring),		\
 	FN(lua_toboolean),		\
-	FN(lua_tointeger),
+	FN(lua_tointeger),		\
+	FN(lua_newpacket),
 	/* #endif CONFIG_XDP_LUA */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper