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

@@ -2826,6 +2826,8 @@ union bpf_attr {
 	FN(sk_storage_delete),		\
 	FN(send_signal),		\
 	/* #ifdef CONFIG_XDPLUA */	\
+	FN(lua_dataref),		\
+	FN(lua_dataunref),		\
 	FN(lua_pcall),			\
 	FN(lua_pop),			\
 	FN(lua_pushinteger),		\

lib/Makefile

@@ -296,5 +296,7 @@ obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
 obj-$(CONFIG_OBJAGG) += objagg.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

@@ -5857,6 +5857,41 @@ static const struct bpf_func_proto bpf_tcp_check_syncookie_proto = {
 #endif /* CONFIG_INET */
 
 #ifdef CONFIG_XDPLUA
+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) {
@@ -6106,6 +6141,10 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 	case BPF_FUNC_trace_printk:
 		return bpf_get_trace_printk_proto();
 #ifdef CONFIG_XDPLUA
+	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

@@ -2825,6 +2825,8 @@ union bpf_attr {
 	FN(sk_storage_get),		\
 	FN(sk_storage_delete),		\
 	/* #ifdef CONFIG_XDPLUA */	\
+	FN(lua_dataref),		\
+	FN(lua_dataunref),		\
 	FN(lua_pcall),			\
 	FN(lua_pop),			\
 	FN(lua_pushinteger),		\

tools/include/uapi/linux/bpf.h

@@ -230,6 +230,10 @@ static int (*bpf_sk_storage_delete)(void *map, struct bpf_sock *sk) =
 static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal;
 
 /* #fidef CONFIG_XDPLUA */
+static int (*bpf_lua_dataref)(void *ctx, int offset) =
+    (void *)BPF_FUNC_lua_dataref;
+static void (*bpf_lua_dataunref)(void *ctx, int data_ref) =
+    (void *)BPF_FUNC_lua_dataunref;
 static void (*bpf_lua_pcall)(void *ctx, char *funcname, int num_args,
 				   int num_rets) =
     (void *) BPF_FUNC_lua_pcall;