fixup! Add initial XDPLua helper version

Author: VictorNogueiraRio

net/core/dev.c

@@ -72,10 +72,17 @@
  *				        - netif_rx() feedback
  */
 
-#include "lua.h"
-#include "lauxlib.h"
-#include "lualib.h"
-#include "luadata.h"
+#ifndef _LUNATIK_H
+#define _LUNATIK_H
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+#endif
+
+#ifndef _LUADATA_H
+#define _LUADATA_H
+#include <luadata.h>
+#endif
 
 #include <linux/uaccess.h>
 #include <linux/bitops.h>
@@ -891,6 +898,8 @@ u32 lua_prog_run_xdp(struct xdp_buff *ctx, const char *func)
 	lua_State *L = NULL;
 	lua_state_cpu *sc;
 	int cpu;
+	int base;
+	int data_ref;
 	u32 ret = 0;
 
 	cpu = smp_processor_id();
@@ -904,16 +913,22 @@ u32 lua_prog_run_xdp(struct xdp_buff *ctx, const char *func)
 	if (!L)
 		goto out;
 
+	base = lua_gettop(L);
 	if (lua_getglobal(L, func) != LUA_TFUNCTION) {
-		printk(KERN_INFO "function %s not found\n", func);
+		printk(KERN_WARNING "function %s not found\n", func);
 		goto out;
 	}
 
-	ldata_newref(L, ctx->data, ctx->data_end - ctx->data);
-	lua_pcall(L, 1, 1, 0);
+	data_ref = ldata_newref(L, ctx->data, ctx->data_end - ctx->data);
+	if (lua_pcall(L, 1, 1, 0)) {
+		printk(KERN_WARNING "%s\n", lua_tostring(L, -1));
+		goto cleanup;
+	}
 	ret = lua_tointeger(L, -1);
-	lua_pop(L, 1);
 
+cleanup:
+	lua_settop(L, base);
+	ldata_unref(L, data_ref);
 out:
 	return ret;
 }
@@ -5219,7 +5234,11 @@ int generic_xdp_lua_install(char *lua_prog) {
 	lua_state_cpu *sc;
 
 	list_for_each_entry(sc, &lua_state_cpu_list, list) {
-		luaL_dostring(sc->L, lua_prog);
+		if (luaL_dostring(sc->L, lua_prog)) {
+			printk(KERN_WARNING "error: %s\nOn cpu: %d\n",
+				lua_tostring(sc->L, -1), sc->cpu);
+			return -1;
+		}
 	}
 
 	return 0;
@@ -9927,6 +9946,7 @@ static int __init net_dev_init(void)
 		}
 
 		luaL_openlibs(new_state_cpu->L);
+		luaL_requiref(new_state_cpu->L, "data", luaopen_data, 1);
 		new_state_cpu->cpu = i;
 
 		list_add(&new_state_cpu->list, &lua_state_cpu_list);

net/core/rtnetlink.c

@@ -1790,11 +1790,11 @@ static const struct nla_policy ifla_port_policy[IFLA_PORT_MAX+1] = {
 };
 
 static const struct nla_policy ifla_xdp_policy[IFLA_XDP_MAX + 1] = {
-	[IFLA_XDP_LUA]		= { .type = NLA_STRING, .len = 1024 },
 	[IFLA_XDP_FD]		= { .type = NLA_S32 },
 	[IFLA_XDP_ATTACHED]	= { .type = NLA_U8 },
 	[IFLA_XDP_FLAGS]	= { .type = NLA_U32 },
 	[IFLA_XDP_PROG_ID]	= { .type = NLA_U32 },
+	[IFLA_XDP_LUA]		= { .type = NLA_STRING, .len = 4096 },
 };
 
 static const struct rtnl_link_ops *linkinfo_to_kind_ops(const struct nlattr *nla)

samples/bpf/xdplua_user.c

@@ -60,7 +60,7 @@ static int do_attach(int idx, int fd, const char *name, char *lua_prog)
 
 	err = bpf_set_link_xdp_lua(idx, lua_prog);
 	if (err < 0)
-		printf("ERROR: failed to attach lua script 2to %s\n", name);
+		printf("ERROR: failed to attach lua script to %s\n", name);
 
 	return err;
 }

tools/lib/bpf/netlink.c

@@ -194,7 +194,7 @@ int bpf_set_link_xdp_lua(int ifindex, char *lua_prog)
 	struct {
 		struct nlmsghdr  nh;
 		struct ifinfomsg ifinfo;
-		char             attrbuf[1088];
+		char             attrbuf[4096];
 	} req;
 	__u32 nl_pid;