Add XDPLua helper version

include/linux/filter.h

@@ -38,6 +38,8 @@ struct sock_reuseport;
 struct ctl_table;
 struct ctl_table_header;
 
+u32 lua_prog_run_xdp(struct xdp_buff *ctx, const char *func);
+
 /* ArgX, context and stack frame pointer register positions. Note,
  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  * calls in BPF_CALL instruction.

include/linux/netdevice.h

@@ -3684,6 +3684,7 @@ 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);
 
+int generic_xdp_lua_install(char *lua_prog);
 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/uapi/linux/bpf.h

@@ -2824,7 +2824,8 @@ union bpf_attr {
 	FN(strtoul),			\
 	FN(sk_storage_get),		\
 	FN(sk_storage_delete),		\
-	FN(send_signal),
+	FN(send_signal),		\
+	FN(lua_run),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

include/uapi/linux/if_link.h

@@ -974,6 +974,7 @@ enum {
 	IFLA_XDP_DRV_PROG_ID,
 	IFLA_XDP_SKB_PROG_ID,
 	IFLA_XDP_HW_PROG_ID,
+	IFLA_XDP_LUA,
 	__IFLA_XDP_MAX,
 };
 

net/core/Makefile

@@ -8,6 +8,7 @@ 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 = -Iinclude/linux/lunatik/ -Iinclude/linux/luadata/ -D_KERNEL
 obj-y		     += dev.o ethtool.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 +68,18 @@
  *				        - netif_rx() feedback
  */
 
+#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>
 #include <linux/capability.h>
@@ -150,11 +162,20 @@
 /* This should be increased if a protocol with a bigger head is added. */
 #define GRO_MAX_HEAD (MAX_HEADER + 128)
 
+struct lua_state_cpu {
+	lua_State 		*L;
+	int			cpu;
+	struct list_head	list;
+};
+
+typedef struct lua_state_cpu lua_state_cpu;
+
 static DEFINE_SPINLOCK(ptype_lock);
 static DEFINE_SPINLOCK(offload_lock);
 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;
+static struct list_head lua_state_cpu_list;
 
 static int netif_rx_internal(struct sk_buff *skb);
 static int call_netdevice_notifiers_info(unsigned long val,
@@ -868,6 +889,46 @@ struct net_device *dev_get_by_index(struct net *net, int ifindex)
 }
 EXPORT_SYMBOL(dev_get_by_index);
 
+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();
+	list_for_each_entry(sc, &lua_state_cpu_list, list) {
+		if (sc->cpu == cpu) {
+			L = sc->L;
+			break;
+		}
+	}
+
+	if (!L)
+		goto out;
+
+	base = lua_gettop(L);
+	if (lua_getglobal(L, func) != LUA_TFUNCTION) {
+		printk(KERN_WARNING "function %s not found\n", func);
+		goto out;
+	}
+
+	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);
+
+cleanup:
+	lua_settop(L, base);
+	ldata_unref(L, data_ref);
+out:
+	return ret;
+}
+
 /**
  *	dev_get_by_napi_id - find a device by napi_id
  *	@napi_id: ID of the NAPI struct
@@ -5183,6 +5244,20 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
 	return ret;
 }
 
+int generic_xdp_lua_install(char *lua_prog) {
+	lua_state_cpu *sc;
+
+	list_for_each_entry(sc, &lua_state_cpu_list, list) {
+		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;
+}
+
 static int netif_receive_skb_internal(struct sk_buff *skb)
 {
 	int ret;
@@ -9800,6 +9875,7 @@ static struct pernet_operations __net_initdata default_device_ops = {
 static int __init net_dev_init(void)
 {
 	int i, rc = -ENOMEM;
+	lua_state_cpu *new_state_cpu;
 
 	BUG_ON(!dev_boot_phase);
 
@@ -9814,6 +9890,7 @@ static int __init net_dev_init(void)
 		INIT_LIST_HEAD(&ptype_base[i]);
 
 	INIT_LIST_HEAD(&offload_base);
+	INIT_LIST_HEAD(&lua_state_cpu_list);
 
 	if (register_pernet_subsys(&netdev_net_ops))
 		goto out;
@@ -9844,6 +9921,22 @@ static int __init net_dev_init(void)
 		init_gro_hash(&sd->backlog);
 		sd->backlog.poll = process_backlog;
 		sd->backlog.weight = weight_p;
+
+		new_state_cpu = (lua_state_cpu *) kmalloc(sizeof(lua_state_cpu), GFP_KERNEL);
+		if (!new_state_cpu)
+			continue;
+
+		new_state_cpu->L = luaL_newstate();
+		if  (!new_state_cpu->L) {
+			kfree(new_state_cpu);
+			continue;
+		}
+
+		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);
 	}
 
 	dev_boot_phase = 0;

net/core/filter.c

@@ -2006,6 +2006,19 @@ static const struct bpf_func_proto bpf_csum_diff_proto = {
 	.arg5_type	= ARG_ANYTHING,
 };
 
+BPF_CALL_2(bpf_lua_run, struct xdp_buff *, ctx, const char *, func)
+{
+	return lua_prog_run_xdp(ctx, func);
+}
+
+static const struct bpf_func_proto bpf_lua_run_proto = {
+	.func           = bpf_lua_run,
+	.gpl_only       = false,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_ANYTHING,
+	.arg2_type      = ARG_ANYTHING,
+};
+
 BPF_CALL_2(bpf_csum_update, struct sk_buff *, skb, __wsum, csum)
 {
 	/* The interface is to be used in combination with bpf_csum_diff()
@@ -6175,6 +6188,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_tcp_check_syncookie:
 		return &bpf_tcp_check_syncookie_proto;
 #endif
+	case BPF_FUNC_lua_run:
+		return &bpf_lua_run_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}

net/core/rtnetlink.c

@@ -1799,6 +1799,7 @@ static const struct nla_policy ifla_xdp_policy[IFLA_XDP_MAX + 1] = {
 	[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)
@@ -2707,6 +2708,10 @@ static int do_setlink(const struct sk_buff *skb,
 				goto errout;
 			status |= DO_SETLINK_NOTIFY;
 		}
+		if (xdp[IFLA_XDP_LUA]) {
+			char *lua_prog = nla_data(xdp[IFLA_XDP_LUA]);
+			generic_xdp_lua_install(lua_prog);
+		}
 	}
 
 errout:

samples/bpf/Makefile

@@ -29,6 +29,7 @@ hostprogs-y += test_cgrp2_attach
 hostprogs-y += test_cgrp2_sock
 hostprogs-y += test_cgrp2_sock2
 hostprogs-y += xdp1
+hostprogs-y += xdplua
 hostprogs-y += xdp2
 hostprogs-y += xdp_router_ipv4
 hostprogs-y += test_current_task_under_cgroup
@@ -109,6 +110,7 @@ task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS)
 xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS)
 ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS)
 hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
+xdplua-objs := xdplua_user.o
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -170,6 +172,7 @@ always += xdp_sample_pkts_kern.o
 always += ibumad_kern.o
 always += hbm_out_kern.o
 always += hbm_edt_kern.o
+always += xdplua_kern.o
 
 KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include
 KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/bpf/

samples/bpf/bpf_load.h

@@ -55,4 +55,5 @@ int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map);
 
 void read_trace_pipe(void);
 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
+int bpf_set_link_xdp_lua(int ifindex, char *lua_prog);
 #endif

samples/bpf/xdplua_kern.c

@@ -0,0 +1,13 @@
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+SEC("xdp1")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	char funcname[] = "callback";
+
+	return bpf_lua_run(ctx, funcname);
+}
+
+char _license[] SEC("license") = "GPL";