net: add bpf_is_local_ipaddr bpf helper function

hulk inclusion
category: feature
bugzilla: NA
CVE: N/A

----------------------------------------------------

Some network acceleration solutions, such as sockmap, are valid only for
internal packets of the local host. The bpf_is_local_ipaddr() bpf helper
function is added so that the ebpf program can determine whether a packet
is an internal packet of the local host.
Signed-off-by: NLiu Jian <liujian56@huawei.com>

arch/arm64/configs/openeuler_defconfig

@@ -3139,6 +3139,7 @@ CONFIG_DLCI_MAX=8
 CONFIG_USB4_NET=m
 # CONFIG_NETDEVSIM is not set
 CONFIG_NET_FAILOVER=m
+CONFIG_NET_LOCALIP_LST=m
 # CONFIG_ISDN is not set
 
 #

arch/x86/configs/openeuler_defconfig

@@ -3216,6 +3216,7 @@ CONFIG_USB4_NET=m
 CONFIG_HYPERV_NET=m
 CONFIG_NETDEVSIM=m
 CONFIG_NET_FAILOVER=m
+CONFIG_NET_LOCALIP_LST=m
 CONFIG_ISDN=y
 CONFIG_ISDN_CAPI=y
 CONFIG_CAPI_TRACE=y

drivers/net/Kconfig

@@ -592,4 +592,12 @@ config NET_FAILOVER
 	  a VM with direct attached VF by failing over to the paravirtual
 	  datapath when the VF is unplugged.
 
+config NET_LOCALIP_LST
+	tristate "Collect local ipv4 address"
+	depends on INET
+	default n
+	help
+	  Similar to inet_addr_lst, only the IP address is recorded, and
+	  net_namespace is not concerned.
+
 endif # NETDEVICES

drivers/net/Makefile

@@ -84,3 +84,4 @@ thunderbolt-net-y += thunderbolt.o
 obj-$(CONFIG_USB4_NET) += thunderbolt-net.o
 obj-$(CONFIG_NETDEVSIM) += netdevsim/
 obj-$(CONFIG_NET_FAILOVER) += net_failover.o
+obj-$(CONFIG_NET_LOCALIP_LST) += localip/

drivers/net/localip/Makefile

+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the linux kernel.
+#
+
+# Object file lists.
+
+obj-$(CONFIG_NET_LOCALIP_LST) += localip.o

drivers/net/localip/localip.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Huawei Technologies Co., Ltd
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/inetdevice.h>
+#include <linux/spinlock.h>
+#include <trace/events/net.h>
+
+#define IN4_ADDR_HSIZE_SHIFT	8
+#define IN4_ADDR_HSIZE		(1U << IN4_ADDR_HSIZE_SHIFT)
+
+static struct hlist_head localip_lst[IN4_ADDR_HSIZE];
+
+static DEFINE_SPINLOCK(localip_lock);
+
+struct localipaddr {
+	struct hlist_node node;
+	struct rcu_head rcu;
+	__u32 ipaddr;
+};
+
+static u32 localip_hash(__be32 addr)
+{
+	return hash_32(addr, IN4_ADDR_HSIZE_SHIFT);
+}
+
+static void localip_hash_insert(struct localipaddr *ip)
+{
+	u32 hash = localip_hash(ip->ipaddr);
+
+	hlist_add_head_rcu(&ip->node, &localip_lst[hash]);
+}
+
+static void localip_hash_remove(struct localipaddr *ip)
+{
+	hlist_del_init_rcu(&ip->node);
+}
+
+static int is_local_ipaddr(uint32_t ipaddr)
+{
+	u32 hash = localip_hash(ipaddr);
+	struct localipaddr *localip;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(localip, &localip_lst[hash], node) {
+		if (localip->ipaddr == ipaddr) {
+			rcu_read_unlock();
+			return 1;
+		}
+	}
+	rcu_read_unlock();
+
+	return 0;
+}
+
+static int localip_event(struct notifier_block *this, unsigned long event,
+			 void *ptr)
+{
+	struct in_ifaddr *ifa = ptr;
+	struct net_device *event_netdev = ifa->ifa_dev->dev;
+	struct localipaddr *localip;
+	u32 hash;
+
+	if (ipv4_is_loopback(ifa->ifa_local))
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_UP:
+		pr_debug("UP, dev:%s, ip:0x%x, mask:0x%x\n", event_netdev->name,
+			 ifa->ifa_local, ifa->ifa_mask);
+		localip = kzalloc(sizeof(struct localipaddr), GFP_KERNEL);
+		if (!localip) {
+			pr_err("kzalloc failed.\n");
+			break;
+		}
+		localip->ipaddr = ifa->ifa_local;
+		spin_lock(&localip_lock);
+		localip_hash_insert(localip);
+		spin_unlock(&localip_lock);
+		break;
+	case NETDEV_DOWN:
+		pr_debug("DOWN, dev:%s, ip:0x%x, mask:0x%x\n", event_netdev->name,
+			 ifa->ifa_local, ifa->ifa_mask);
+		hash = localip_hash(ifa->ifa_local);
+		spin_lock(&localip_lock);
+		hlist_for_each_entry(localip, &localip_lst[hash], node) {
+			if (localip->ipaddr == ifa->ifa_local) {
+				localip_hash_remove(localip);
+				kfree_rcu(localip, rcu);
+				break;
+			}
+		}
+		spin_unlock(&localip_lock);
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block localip_notifier = {
+	.notifier_call  = localip_event,
+};
+
+static void is_local_ipaddr_trace(void *data, int *ret, uint32_t ipaddr)
+{
+	*ret = is_local_ipaddr(ipaddr);
+}
+
+static int localip_init(void)
+{
+	int i, err;
+
+	for (i = 0; i < IN4_ADDR_HSIZE; i++)
+		INIT_HLIST_HEAD(&localip_lst[i]);
+
+	err = register_inetaddr_notifier(&localip_notifier);
+	if (err)
+		return err;
+
+	err = register_trace_is_local_ipaddr(is_local_ipaddr_trace, NULL);
+	if (err) {
+		pr_err("Failed to connet probe to is_local_ipaddr.\n");
+		unregister_inetaddr_notifier(&localip_notifier);
+		return err;
+	}
+	return 0;
+}
+
+static void localip_cleanup(void)
+{
+	struct localipaddr *localip;
+	struct hlist_node *n;
+	int i;
+
+	unregister_trace_is_local_ipaddr(is_local_ipaddr_trace, NULL);
+	unregister_inetaddr_notifier(&localip_notifier);
+
+	spin_lock(&localip_lock);
+	for (i = 0; i < IN4_ADDR_HSIZE; i++) {
+		hlist_for_each_entry_safe(localip, n, &localip_lst[i], node) {
+			pr_debug("cleanup, hash:%i, ip:0x%x\n", i, localip->ipaddr);
+			localip_hash_remove(localip);
+			kfree_rcu(localip, rcu);
+		}
+	}
+	spin_unlock(&localip_lock);
+	synchronize_rcu();
+}
+
+module_init(localip_init);
+module_exit(localip_cleanup);
+MODULE_LICENSE("GPL");

include/trace/events/net.h

@@ -326,6 +326,10 @@ DEFINE_EVENT(net_dev_rx_exit_template, netif_receive_skb_list_exit,
 	TP_ARGS(ret)
 );
 
+DECLARE_TRACE(is_local_ipaddr,
+	TP_PROTO(int *ret, u32 ipaddr),
+	TP_ARGS(ret, ipaddr));
+
 #endif /* _TRACE_NET_H */
 
 /* This part must be outside protection */

include/uapi/linux/bpf.h

@@ -3872,6 +3872,12 @@ union bpf_attr {
  *		check src_cpu whether share cache with dst_cpu.
  *	Return
  *		yes 1, no 0.
+ *
+ * long bpf_is_local_ipaddr(u32 ipaddr)
+ *	Description
+ *		Check the ipaddr is local address or not.
+ *	Return
+ *		1 is local address, 0 is not.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -4044,6 +4050,7 @@ union bpf_attr {
 	FN(sched_entity_to_tg),		\
 	FN(cpumask_op),			\
 	FN(cpus_share_cache),		\
+	FN(is_local_ipaddr),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

net/core/filter.c

@@ -77,6 +77,7 @@
 #include <net/transp_v6.h>
 #include <linux/btf_ids.h>
 #include <net/tls.h>
+#include <trace/events/net.h>
 
 static const struct bpf_func_proto *
 bpf_sk_base_func_proto(enum bpf_func_id func_id);
@@ -5084,6 +5085,21 @@ static const struct bpf_func_proto bpf_sk_original_addr_proto = {
 	.arg4_type	= ARG_CONST_SIZE,
 };
 
+BPF_CALL_1(bpf_is_local_ipaddr, uint32_t, ipaddr)
+{
+	int ret = 0;
+
+	trace_is_local_ipaddr(&ret, ipaddr);
+	return ret;
+}
+
+static const struct bpf_func_proto bpf_is_local_ipaddr_proto = {
+	.func		= bpf_is_local_ipaddr,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+};
+
 BPF_CALL_5(bpf_sock_addr_getsockopt, struct bpf_sock_addr_kern *, ctx,
 	   int, level, int, optname, char *, optval, int, optlen)
 {
@@ -7398,6 +7414,8 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_tcp_sock:
 		return &bpf_tcp_sock_proto;
 #endif /* CONFIG_INET */
+	case BPF_FUNC_is_local_ipaddr:
+		return &bpf_is_local_ipaddr_proto;
 	default:
 		return bpf_sk_base_func_proto(func_id);
 	}

net/core/net-traces.c

@@ -60,3 +60,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
 EXPORT_TRACEPOINT_SYMBOL_GPL(napi_poll);
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(tcp_send_reset);
+EXPORT_TRACEPOINT_SYMBOL_GPL(is_local_ipaddr);

tools/include/uapi/linux/bpf.h

@@ -3872,6 +3872,12 @@ union bpf_attr {
  *		check src_cpu whether share cache with dst_cpu.
  *	Return
  *		true yes, false no.
+ *
+ * long bpf_is_local_ipaddr(u32 ipaddr)
+ *     Description
+ *             Check the ipaddr is local address or not.
+ *     Return
+ *             1 is local address, 0 is not.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -4044,6 +4050,7 @@ union bpf_attr {
 	FN(sched_entity_to_tg),		\
 	FN(cpumask_op),			\
 	FN(cpus_share_cache),		\
+	FN(is_local_ipaddr),            \
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper