add fib

Signed-off-by: duxbbo <duxiaobo@huawei.com>

code/linux/net/newip/nip_fib.c

@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Huawei Device Co., Ltd.
+ *
+ * Linux NewIP INET implementation
+ * Forwarding Information Database
+ *
+ * Based on net/ipv6/ip6_fib.c
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/net.h>
+#include <linux/route.h>
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+
+#include <net/nip.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+
+#include <net/nip_fib.h>
+#include <net/nip_route.h>
+
+static struct kmem_cache *nip_fib_node_kmem __read_mostly;
+
+struct nip_fib_table *nip_fib_get_table(struct net *net, u32 id)
+{
+	if (id == NIP_RT_TABLE_MAIN)
+		return net->newip.nip_fib_main_tbl;
+	else if (id == NIP_RT_TABLE_LOCAL)
+		return net->newip.nip_fib_local_tbl;
+	else
+		return NULL;
+}
+
+static struct nip_fib_node *nip_node_alloc(void)
+{
+	struct nip_fib_node *fn;
+
+	fn = kmem_cache_zalloc(nip_fib_node_kmem, GFP_ATOMIC);
+
+	return fn;
+}
+
+void nip_rt_free_pcpu(struct nip_rt_info *non_pcpu_rt)
+{
+	int cpu;
+
+	if (!non_pcpu_rt->rt_pcpu)
+		return;
+
+	for_each_possible_cpu(cpu) {
+		struct nip_rt_info **ppcpu_rt;
+		struct nip_rt_info *pcpu_rt;
+
+		ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt_pcpu, cpu);
+		pcpu_rt = *ppcpu_rt;
+		if (pcpu_rt) {
+			dst_dev_put(&pcpu_rt->dst);
+			dst_release(&pcpu_rt->dst);
+			*ppcpu_rt = NULL;
+		}
+	}
+
+	free_percpu(non_pcpu_rt->rt_pcpu);
+	non_pcpu_rt->rt_pcpu = NULL;
+}
+
+static u32 ninet_route_hash(const struct nip_addr *addr)
+{
+	return hash_32(nip_addr_hash(addr), NIN_ROUTE_HSIZE_SHIFT);
+}
+
+struct nip_fib_node *nip_fib_locate(struct hlist_head *nip_tb_head,
+				    const struct nip_addr *daddr)
+{
+	struct nip_fib_node *fib_node;
+	struct hlist_head *h;
+	unsigned int hash;
+
+	hash = ninet_route_hash(daddr);
+	h = &nip_tb_head[hash];
+
+	hlist_for_each_entry_rcu(fib_node, h, fib_hlist) {
+		if (nip_addr_eq(&fib_node->nip_route_info->rt_dst, daddr))
+			return fib_node;
+	}
+
+	/* find default route */
+	hash = ninet_route_hash(&nip_any_addr);
+	h = &nip_tb_head[hash];
+
+	hlist_for_each_entry_rcu(fib_node, h, fib_hlist) {
+		if (nip_addr_eq
+		    (&fib_node->nip_route_info->rt_dst, &nip_any_addr)) {
+			return fib_node;
+		}
+	}
+
+	return NULL;
+}
+
+/* nip_tb_lock must be taken to avoid racing */
+int nip_fib_add(struct hlist_head *nip_tb_head, struct nip_rt_info *rt)
+{
+	struct nip_fib_node *fib_node, *new_node;
+	int err = 0;
+	struct hlist_head *h;
+	unsigned int hash;
+
+	hash = ninet_route_hash(&rt->rt_dst);
+	h = &nip_tb_head[hash];
+
+	hlist_for_each_entry(fib_node, h, fib_hlist) {
+		if (nip_addr_eq(&fib_node->nip_route_info->rt_dst,
+				&rt->rt_dst)) {
+			err = -EEXIST;
+			goto fail;
+		}
+	}
+
+	new_node = nip_node_alloc();
+	if (!new_node) {
+		DEBUG("%s: fail to alloc mem.", __func__);
+		err = -ENOMEM;
+		goto fail;
+	}
+	new_node->nip_route_info = rt;
+	rcu_assign_pointer(rt->rt_node, new_node);
+	atomic_inc(&rt->rt_ref);
+	hlist_add_tail_rcu(&new_node->fib_hlist, h);
+
+out:
+	return err;
+
+fail:
+	dst_release_immediate(&rt->dst);
+	goto out;
+}
+
+static void nip_fib_destroy_rcu(struct rcu_head *head)
+{
+	struct nip_fib_node *fn = container_of(head, struct nip_fib_node, rcu);
+
+	nip_rt_release(fn->nip_route_info);
+	kfree(fn);
+}
+
+/* nip_tb_lock must be taken to avoid racing */
+int nip_fib_del(struct nip_rt_info *rt, struct nl_info *info)
+{
+	struct nip_fib_node *fn;
+	struct net *net = info->nl_net;
+
+	fn = rcu_dereference_protected(rt->rt_node,
+				       lockdep_is_held(&rt->rt_table->nip_tb_lock));
+	if (!fn || rt == net->newip.nip_null_entry)
+		return -ENOENT;
+
+	hlist_del_init_rcu(&fn->fib_hlist);
+
+	/* 当fib_node释放后，fib_node指向的route_info才可释放 */
+	RCU_INIT_POINTER(rt->rt_node, NULL);
+	call_rcu(&fn->rcu, nip_fib_destroy_rcu);
+
+	return 0;
+}
+
+static void nip_fib_free_table(struct nip_fib_table *table)
+{
+	kfree(table);
+}
+
+/* caller must hold nip_tb_lock */
+static void nip_fib_clean_hash(struct net *net, struct hlist_head *nip_tb_head,
+			       int (*func)(struct nip_rt_info *, void *arg),
+			       void *arg)
+{
+	int i;
+	struct nip_fib_node *fn;
+	struct hlist_node *tmp;
+	struct nl_info info = {
+		.nl_net = net,
+	};
+
+	for (i = 0; i < NIN_ROUTE_HSIZE; i++) {
+		struct hlist_head *h = &nip_tb_head[i];
+
+		hlist_for_each_entry_safe(fn, tmp, h, fib_hlist) {
+			if (func(fn->nip_route_info, arg) < 0) {
+				DEBUG("%s: try to del nip_rt_info\n", __func__);
+				nip_fib_del(fn->nip_route_info, &info);
+			}
+		}
+	}
+}
+
+void nip_fib_clean_all(struct net *net,
+		       int (*func)(struct nip_rt_info *, void *arg), void *arg)
+{
+	struct nip_fib_table *main_tbl = net->newip.nip_fib_main_tbl;
+	struct nip_fib_table *local_tbl = net->newip.nip_fib_local_tbl;
+
+	spin_lock_bh(&main_tbl->nip_tb_lock);
+	nip_fib_clean_hash(net, main_tbl->nip_tb_head, func, arg);
+	spin_unlock_bh(&main_tbl->nip_tb_lock);
+
+	spin_lock_bh(&local_tbl->nip_tb_lock);
+	nip_fib_clean_hash(net, local_tbl->nip_tb_head, func, arg);
+	spin_unlock_bh(&local_tbl->nip_tb_lock);
+}
+
+static void nip_fib_link_table(struct nip_fib_table *tb)
+{
+	/* You need to initialize multiple routing tables */
+	spin_lock_init(&tb->nip_tb_lock);
+}
+
+static void __net_init nip_fib_tables_init(struct net *net)
+{
+	nip_fib_link_table(net->newip.nip_fib_main_tbl);
+	nip_fib_link_table(net->newip.nip_fib_local_tbl);
+}
+
+static int __net_init nip_fib_net_init(struct net *net)
+{
+	net->newip.nip_fib_main_tbl =
+	    kzalloc(sizeof(*net->newip.nip_fib_main_tbl), GFP_KERNEL);
+	if (!net->newip.nip_fib_main_tbl)
+		goto out_fib_table_hash;
+
+	net->newip.nip_fib_main_tbl->nip_tb_id = NIP_RT_TABLE_MAIN;
+	net->newip.nip_fib_main_tbl->flags = 1;
+
+	net->newip.nip_fib_local_tbl =
+	    kzalloc(sizeof(*net->newip.nip_fib_local_tbl), GFP_KERNEL);
+	if (!net->newip.nip_fib_local_tbl)
+		goto out_main_tbl;
+
+	net->newip.nip_fib_local_tbl->nip_tb_id = NIP_RT_TABLE_LOCAL;
+
+	nip_fib_tables_init(net);
+
+	return 0;
+
+out_main_tbl:
+	kfree(net->newip.nip_fib_main_tbl);
+out_fib_table_hash:
+	return -ENOMEM;
+}
+
+static void nip_fib_net_exit(struct net *net)
+{
+	nip_fib_free_table(net->newip.nip_fib_main_tbl);
+	nip_fib_free_table(net->newip.nip_fib_local_tbl);
+}
+
+static struct pernet_operations nip_fib_net_ops = {
+	.init = nip_fib_net_init,
+	.exit = nip_fib_net_exit,
+};
+
+int __init nip_fib_init(void)
+{
+	int ret = -ENOMEM;
+
+	nip_fib_node_kmem = kmem_cache_create("nip_fib_nodes",
+					      sizeof(struct nip_fib_node),
+					      0, SLAB_HWCACHE_ALIGN, NULL);
+	if (!nip_fib_node_kmem)
+		goto out;
+
+	DEBUG("nip_fib_node size is %lu\n",
+	      sizeof(struct nip_fib_node) + sizeof(struct nip_rt_info));
+
+	ret = register_pernet_subsys(&nip_fib_net_ops);
+	if (ret)
+		goto out_kmem_cache_create;
+
+out:
+	return ret;
+
+out_kmem_cache_create:
+	kmem_cache_destroy(nip_fib_node_kmem);
+	goto out;
+}
+
+void nip_fib_gc_cleanup(void)
+{
+	unregister_pernet_subsys(&nip_fib_net_ops);
+	kmem_cache_destroy(nip_fib_node_kmem);
+}
+

code/linux/net/newip/nip_fib_rules.c

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Huawei Device Co., Ltd.
+ *
+ * NewIP Routing Policy Rules
+ *
+ * Based on net/ipv6/fib_rules.c
+ * Based on net/ipv6/fib6_rules.c
+ */
+#include <net/nip_fib.h>
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/export.h>
+
+struct dst_entry *nip_fib_rule_lookup(struct net *net, struct flow_nip *fln,
+				      int flags, nip_pol_lookup_t lookup)
+{
+	struct nip_rt_info *rt;
+
+	rt = lookup(net, net->newip.nip_fib_local_tbl, fln, flags);
+	if (rt != net->newip.nip_null_entry)
+		return &rt->dst;
+	nip_rt_put(rt);
+	rt = lookup(net, net->newip.nip_fib_main_tbl, fln, flags);
+	if (rt != net->newip.nip_null_entry)
+		return &rt->dst;
+	nip_rt_put(rt);
+
+	dst_hold(&net->newip.nip_null_entry->dst);
+	return &net->newip.nip_null_entry->dst;
+}

code/linux/net/newip/nndisc.c

@@ -0,0 +1,602 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Huawei Device Co., Ltd.
+ *
+ * Neighbour Discovery for NewIP
+ * Linux NewIP INET implementation
+ *
+ * Based on net/ipv6/ndisc.c
+ */
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/route.h>
+#include <linux/init.h>
+#include <linux/rcupdate.h>
+#include <linux/nip.h>
+#include <linux/nip_icmp.h>
+#include <linux/jhash.h>
+#include <net/sock.h>
+#include <net/nip.h>
+#include <net/nip_udp.h>
+#include <net/protocol.h>
+#include <net/nndisc.h>
+#include <net/nip_route.h>
+#include <net/addrconf.h>
+#include <net/nip_fib.h>
+#include <net/netlink.h>
+#include <linux/rtnetlink.h>
+#include <net/flow.h>
+#include <net/inet_common.h>
+#include <net/nip_addrconf.h>
+#include <linux/newip_route.h>
+#include <linux/netfilter.h>
+#include "nip_hdr.h"
+#include "nip_checksum.h"
+
+/* NUD_INCOMPLETE
+ * The neighbor request packet has been sent but no response has been received
+ * NUD_REACHABLE
+ * Reachable: Indicates that the neighbor is reachable
+ * NUD_STAL
+ * Idle state, which has not been confirmed for a long time,
+ * and the idle time exceeds the rated time
+ * NUD_DELAY
+ * If the acknowledgment time expires but the idle time does not exceed the rated time,
+ * you need to obtain the acknowledgment packet
+ * NUD_PROBE
+ * After NUD_DELAY does not receive confirmation for a long time, ARP request messages are sent
+ * NUD_FAILED
+ * The neighbor is unreachable
+ * NUD_NOARP
+ * Indicates the status of the neighbor that does not need the ARP status change
+ * NUD_PERMANENT
+ * Indicates that the status of the neighbor item is permanent and does not need to change
+ * NUD_NONE
+ * Initialization status of the neighbor item
+ */
+static void nndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
+
+static u32 nndisc_hash(const void *pkey,
+		       const struct net_device *dev, __u32 *fhash_rnd);
+static bool nndisc_key_eq(const struct neighbour *neigh, const void *pkey);
+static int nndisc_constructor(struct neighbour *neigh);
+
+static void nndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
+{
+	kfree_skb(skb);
+}
+
+static const struct neigh_ops nndisc_generic_ops = {
+	.family = AF_NINET,
+	.solicit = nndisc_solicit,
+	.output = neigh_resolve_output,
+	.connected_output = neigh_connected_output,
+};
+
+static const struct neigh_ops nndisc_hh_ops = {
+	.family = AF_NINET,
+	.solicit = nndisc_solicit,
+	.error_report = nndisc_error_report,
+	.output = neigh_resolve_output,
+	.connected_output = neigh_resolve_output,
+};
+
+static const struct neigh_ops nndisc_direct_ops = {
+	.family = AF_NINET,
+	.output = neigh_direct_output,
+	.connected_output = neigh_direct_output,
+};
+
+#define NIP_NEIGH_MCAST_PROBES 4
+#define NIP_NEIGH_UCAST_PROBES 4
+#define NIP_NEIGH_DELAY_PROBE_TIME (5 * HZ)
+#define NIP_NEIGH_GC_STALETIME (60 * HZ)
+#define NIP_NEIGH_QUEUE_LEN_BYTES (64 * 1024)
+#define NIP_NEIGH_PROXY_QLEN 64
+#define NIP_NEIGH_ANYCAST_DELAY (1 * HZ)
+#define NIP_NEIGH_PROXY_DELAY ((8 * HZ) / 10)
+#define NIP_NEIGH_GC_INTERVAL (30 * HZ)
+#define NIP_NEIGH_GC_THRESH_1 128
+#define NIP_NEIGH_GC_THRESH_2 512
+#define NIP_NEIGH_GC_THRESH_3 1024
+
+struct neigh_table nnd_tbl = {
+	.family = AF_NINET,
+	.key_len = sizeof(struct nip_addr),
+	.protocol = cpu_to_be16(ETH_P_NEWIP),
+	.hash = nndisc_hash,
+	.key_eq = nndisc_key_eq,
+	.constructor = nndisc_constructor,
+	.id = "nndisc_cache",
+	.parms = {
+		  .tbl = &nnd_tbl,
+		  .reachable_time = ND_REACHABLE_TIME,
+		  .data = {
+			   [NEIGH_VAR_MCAST_PROBES] = NIP_NEIGH_MCAST_PROBES,
+			   [NEIGH_VAR_UCAST_PROBES] = NIP_NEIGH_UCAST_PROBES,
+			   [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
+			   [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
+			   [NEIGH_VAR_DELAY_PROBE_TIME] = NIP_NEIGH_DELAY_PROBE_TIME,
+			   [NEIGH_VAR_GC_STALETIME] = NIP_NEIGH_GC_STALETIME,
+			   [NEIGH_VAR_QUEUE_LEN_BYTES] = NIP_NEIGH_QUEUE_LEN_BYTES,
+			   [NEIGH_VAR_PROXY_QLEN] = NIP_NEIGH_PROXY_QLEN,
+			   [NEIGH_VAR_ANYCAST_DELAY] = NIP_NEIGH_ANYCAST_DELAY,
+			   [NEIGH_VAR_PROXY_DELAY] = NIP_NEIGH_PROXY_DELAY,
+			   },
+		   },
+	.gc_interval = NIP_NEIGH_GC_INTERVAL,
+	.gc_thresh1 = NIP_NEIGH_GC_THRESH_1,
+	.gc_thresh2 = NIP_NEIGH_GC_THRESH_2,
+	.gc_thresh3 = NIP_NEIGH_GC_THRESH_3,
+};
+
+static u32 nndisc_hash(const void *pkey,
+		       const struct net_device *dev, __u32 *hash_rnd)
+{
+	return nndisc_hashfn(pkey, dev, hash_rnd);
+}
+
+static bool nndisc_key_eq(const struct neighbour *n, const void *pkey)
+{
+	return neigh_key_eq800(n, pkey);
+}
+
+static int nndisc_constructor(struct neighbour *neigh)
+{
+	struct nip_addr *addr = (struct nip_addr *)&neigh->primary_key;
+	struct net_device *dev = neigh->dev;
+	struct ninet_dev *nin_dev;
+	struct neigh_parms *parms;
+	bool is_broadcast = (bool)nip_addr_eq(addr, &nip_broadcast_addr_arp);
+
+	nin_dev = nin_dev_get(dev);
+	if (!nin_dev)
+		return -EINVAL;
+
+	parms = nin_dev->nd_parms;
+	__neigh_parms_put(neigh->parms);
+	neigh->parms = neigh_parms_clone(parms);
+	neigh->type = RTN_UNICAST;
+	if (!dev->header_ops) {
+		neigh->nud_state = NUD_NOARP;
+		neigh->ops = &nndisc_direct_ops;
+		neigh->output = neigh_direct_output;
+	} else {
+		if (is_broadcast ||
+		    (dev->flags & IFF_POINTOPOINT)) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
+		} else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
+			if (dev->flags & IFF_LOOPBACK)
+				neigh->type = RTN_LOCAL;
+		}
+
+		if (dev->header_ops->cache)
+			neigh->ops = &nndisc_hh_ops;
+		else
+			neigh->ops = &nndisc_generic_ops;
+
+		if (neigh->nud_state & NUD_VALID)
+			neigh->output = neigh->ops->connected_output;
+		else
+			neigh->output = neigh->ops->output;
+	}
+
+	nin_dev_put(nin_dev);
+
+	return 0;
+}
+
+void nip_insert_nndisc_send_checksum(struct sk_buff *skb, u_short checksum)
+{
+#define NNDISC_CHECKSUM_BIAS 2
+	*(__u16 *)(skb_transport_header(skb) + NNDISC_CHECKSUM_BIAS) =
+	htons(checksum);
+}
+
+unsigned short nip_get_nndisc_send_checksum(struct sk_buff *skb,
+					    struct nip_hdr_encap *head,
+					    int payload_len)
+{
+	struct nip_pseudo_header nph = {0};
+
+	nph.nexthdr = head->nexthdr;
+	nph.saddr = head->saddr;
+	nph.daddr = head->daddr;
+	nph.check_len = htons(payload_len);
+	return nip_check_sum_build(skb_transport_header(skb),
+				   payload_len, &nph);
+}
+
+bool nip_get_nndisc_rcv_checksum(struct sk_buff *skb,
+				 u_char *transport_tail)
+{
+	struct nip_pseudo_header nph = {0};
+	unsigned short check_len = (unsigned short)(transport_tail - (skb_transport_header(skb)));
+
+	nph.nexthdr = NIPCB(skb)->nexthdr;
+	nph.saddr = NIPCB(skb)->srcaddr;
+	nph.daddr = NIPCB(skb)->dstaddr;
+	nph.check_len = htons(check_len);
+
+	return nip_check_sum_parse(skb_transport_header(skb), check_len, &nph)
+	       == 0xffff ? true : false;
+}
+
+static void nndisc_payload_ns_pack(const struct nip_addr *solicit,
+				   struct sk_buff *skb)
+{
+	struct nnd_msg *msg = (struct nnd_msg *)skb->data;
+	u_char *p = msg->data;
+
+	memset(&msg->icmph, 0, sizeof(msg->icmph));
+	msg->icmph.nip_icmp_type = NIP_ARP_NS;
+	msg->icmph.nip_icmp_cksum = 0;
+	p = build_nip_addr(solicit, p);
+}
+
+static struct dst_entry *nndisc_dst_alloc(struct net_device *dev)
+{
+	struct nip_rt_info *rt;
+	struct net *net = dev_net(dev);
+
+	rt = nip_dst_alloc(net, dev, 0);
+	if (!rt)
+		return NULL;
+
+	rt->dst.flags |= DST_HOST;
+	rt->dst.input = nip_input;
+	rt->dst.output = nip_output;
+	atomic_set(&rt->dst.__refcnt, 1);
+
+	return &rt->dst;
+}
+
+static int get_ns_payload_len(const struct nip_addr *solicit)
+{
+	return sizeof(struct nip_icmp_hdr) + get_nip_addr_len(solicit);
+}
+
+static void nndisc_send_ns(struct net_device *dev,
+			   const struct nip_addr *solicit,
+			   const struct nip_addr *daddr,
+			   const struct nip_addr *saddr)
+{
+	int ret;
+	struct sk_buff *skb;
+	struct dst_entry *dst;
+	struct net *net;
+	struct sock *sk = NULL;
+	int payload_len = get_ns_payload_len(solicit);
+	int len = NIP_ETH_HDR_LEN + NIP_HDR_MAX + payload_len;
+	struct nip_hdr_encap head = {0};
+	unsigned short checksum;
+
+	head.saddr = *saddr;
+	head.daddr = *daddr;
+	head.ttl = NIP_ARP_DEFAULT_TTL;
+	head.nexthdr = IPPROTO_NIP_ICMP;
+
+	skb = alloc_skb(len, 0);
+	if (!skb) {
+		DEBUG("%s: no space for skbuff!", __func__);
+		return;
+	}
+
+	skb->protocol = htons(ETH_P_NEWIP);
+	skb->dev = dev;
+	skb->ip_summed = CHECKSUM_NONE;
+	skb->csum = 0;
+	memset(NIPCB(skb), 0, sizeof(struct ninet_skb_parm));
+
+	NIPCB(skb)->dstaddr = head.daddr;
+	NIPCB(skb)->srcaddr = head.saddr;
+	NIPCB(skb)->nexthdr = head.nexthdr;
+
+	/* reserve space for hardware header */
+	skb_reserve(skb, NIP_ETH_HDR_LEN);
+	skb_reset_network_header(skb);
+
+	/* build nwk header */
+	head.hdr_buf = (unsigned char *)skb->data;
+	nip_hdr_comm_encap(&head);
+	head.total_len = head.hdr_buf_pos + payload_len;
+	nip_update_total_len(&head, htons(head.total_len));
+	skb_reserve(skb, head.hdr_buf_pos);
+	skb_reset_transport_header(skb);
+
+	/* build transport header */
+	nndisc_payload_ns_pack(solicit, skb);
+	skb_reserve(skb, payload_len);
+
+	skb->data = skb_network_header(skb);
+	skb->len = head.hdr_buf_pos + payload_len;
+
+	dst = nndisc_dst_alloc(dev);
+	if (!dst) {
+		kfree_skb(skb);
+		return;
+	}
+
+	/* add check sum*/
+	checksum = nip_get_nndisc_send_checksum(skb, &head, payload_len);
+	nip_insert_nndisc_send_checksum(skb, checksum);
+
+	skb_dst_set(skb, dst);
+	net = dev_net(skb->dev);
+
+	/* DST is set to SKB, and output is used to release SKB regardless of success or failure */
+	ret = dst_output(net, sk, skb);
+	if (ret)
+		DEBUG("%s: dst output fail.", __func__);
+}
+
+static void nndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
+{
+	struct net_device *dev = neigh->dev;
+	struct nip_addr *target = (struct nip_addr *)&neigh->primary_key;
+	struct nip_addr *saddr = NULL;
+	struct ninet_dev *idev;
+
+	/* Obtain the NewIP address from the current dev as
+	 * the source address of the request packet
+	 */
+	rcu_read_lock();
+	idev = __nin_dev_get(dev);
+	if (idev) {
+		read_lock_bh(&idev->lock);
+		if (!list_empty(&idev->addr_list)) {
+			struct ninet_ifaddr *ifp;
+
+			list_for_each_entry(ifp, &idev->addr_list, if_list) {
+				saddr = &ifp->addr;
+				nndisc_send_ns(dev, target,
+					       &nip_broadcast_addr_arp,
+					       saddr);
+			}
+		}
+		read_unlock_bh(&idev->lock);
+	} else {
+		DEBUG("%s:idev don't exist.", __func__);
+	}
+	rcu_read_unlock();
+}
+
+static void build_na_hdr(u_char *smac, u_char mac_len, struct sk_buff *skb)
+{
+	struct nnd_msg *msg = (struct nnd_msg *)skb->data;
+	u_char *p = msg->data;
+
+	memset(&msg->icmph, 0, sizeof(msg->icmph));
+	msg->icmph.nip_icmp_type = NIP_ARP_NA;
+	msg->icmph.nip_icmp_cksum = 0;
+	*p = mac_len;
+	p++;
+	memcpy(p, smac, mac_len);
+}
+
+static int get_na_payload_len(struct net_device *dev)
+{
+	/* Icmp Header Length
+	 * Number of bytes in the MAC address length field
+	 * MAC Address Length
+	 */
+	return sizeof(struct nip_icmp_hdr) + 1 + dev->addr_len;
+}
+
+static void nndisc_send_na(struct net_device *dev,
+			   const struct nip_addr *daddr,
+			   const struct nip_addr *saddr)
+{
+	int ret;
+	struct sk_buff *skb = NULL;
+	struct dst_entry *dst = NULL;
+	struct sock *sk = NULL;
+	int csummode = CHECKSUM_NONE;
+	int payload_len = get_na_payload_len(dev);
+	int len = NIP_ETH_HDR_LEN + NIP_HDR_MAX + payload_len;
+	u_char *smac = dev->dev_addr;
+	struct nip_hdr_encap head = {0};
+	u_short checksum = 0;
+
+	head.saddr = *saddr;
+	head.daddr = *daddr;
+	head.ttl = NIP_ARP_DEFAULT_TTL;
+	head.nexthdr = IPPROTO_NIP_ICMP;
+
+	skb = alloc_skb(len, 0);
+	if (!skb) {
+		DEBUG("%s: no space for skbuff!", __func__);
+		return;
+	}
+	skb->protocol = htons(ETH_P_NEWIP);
+	skb->ip_summed = csummode;
+	skb->csum = 0;
+	skb->dev = dev;
+	memset(NIPCB(skb), 0, sizeof(struct ninet_skb_parm));
+
+	NIPCB(skb)->dstaddr = head.daddr;
+	NIPCB(skb)->srcaddr = head.saddr;
+	NIPCB(skb)->nexthdr = head.nexthdr;
+
+	/* reserve space for hardware header */
+	skb_reserve(skb, NIP_ETH_HDR_LEN);
+	skb_reset_network_header(skb);
+
+	/* build nwk header */
+	head.hdr_buf = (unsigned char *)skb->data;
+	nip_hdr_comm_encap(&head);
+	head.total_len = head.hdr_buf_pos + payload_len;
+	nip_update_total_len(&head, htons(head.total_len));
+	skb_reserve(skb, head.hdr_buf_pos);
+	skb_reset_transport_header(skb);
+
+	/* build na header */
+	build_na_hdr(smac, dev->addr_len, skb);
+
+	/* skip transport hdr */
+	skb_reserve(skb, payload_len);
+
+	/* set skb->data to point network header */
+	skb->data = skb_network_header(skb);
+	skb->len = head.hdr_buf_pos + payload_len;
+
+	dst = nndisc_dst_alloc(dev);
+	if (!dst) {
+		kfree_skb(skb);
+		return;
+	}
+
+	/* add check sum*/
+	checksum = nip_get_nndisc_send_checksum(skb, &head, payload_len);
+	nip_insert_nndisc_send_checksum(skb, checksum);
+
+	skb_dst_set(skb, dst);
+	ret = dst_output(dev_net(skb->dev), sk, skb);
+	if (ret)
+		DEBUG("%s: dst output fail.", __func__);
+}
+
+bool nip_addr_local(struct net_device *dev, struct nip_addr *addr)
+{
+	struct ninet_dev *idev;
+	bool ret = false;
+
+	rcu_read_lock();
+	idev = __nin_dev_get(dev);
+	if (idev) {
+		read_lock_bh(&idev->lock);
+		if (!list_empty(&idev->addr_list)) {
+			struct ninet_ifaddr *ifp;
+
+			list_for_each_entry(ifp, &idev->addr_list, if_list) {
+				if (nip_addr_eq(addr, &ifp->addr)) {
+					ret = true;
+					break;
+				}
+			}
+		}
+		read_unlock_bh(&idev->lock);
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int nndisc_rcv_ns(struct sk_buff *skb)
+{
+	struct nnd_msg *msg = (struct nnd_msg *)skb_transport_header(skb);
+	u_char *p = msg->data;
+	u_char *lladdr;
+	struct nip_addr addr = {0};
+	struct neighbour *neigh;
+	struct ethhdr *eth;
+	struct net_device *dev = skb->dev;
+	int err = 0;
+
+	p = decode_nip_addr(p, &addr);
+	if (!p) {
+		DEBUG("failure when decode source address!");
+		err = -EFAULT;
+		goto out;
+	}
+
+	if (nip_addr_invalid(&addr)) {
+		DEBUG("%s: icmp hdr addr invalid.", __func__);
+		err = -EFAULT;
+		goto out;
+	}
+
+	if (!nip_addr_local(dev, &addr)) {
+		err = -ENXIO;
+		goto out;
+	}
+
+	eth = (struct ethhdr *)skb_mac_header(skb);
+	lladdr = eth->h_source;
+
+	/* checksum parse*/
+	if (!nip_get_nndisc_rcv_checksum(skb, p)) {
+		DEBUG("%s:ns ICMP checksum failed, drop the packet", __func__);
+		err = -EINVAL;
+		goto out;
+	}
+
+	neigh = __neigh_lookup(&nnd_tbl, &NIPCB(skb)->srcaddr, dev, lladdr ||
+			       !dev->addr_len);
+	if (neigh) {
+		neigh_update(neigh, lladdr, NUD_STALE, NEIGH_UPDATE_F_OVERRIDE,
+			     0);
+		neigh_release(neigh);
+	}
+
+	nndisc_send_na(dev, &NIPCB(skb)->srcaddr, &addr);
+out:
+	kfree_skb(skb);
+	return err;
+}
+
+int nndisc_rcv_na(struct sk_buff *skb)
+{
+	struct nnd_msg *msg = (struct nnd_msg *)skb_transport_header(skb);
+	u_char *p = msg->data;
+	u_char len;
+	u8 lladdr[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
+	struct net_device *dev = skb->dev;
+	struct neighbour *neigh;
+
+	len = *p;
+	p++;
+	memset(lladdr, 0, ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)));
+	memcpy(lladdr, p, len);
+
+	if (!nip_get_nndisc_rcv_checksum(skb, p + len)) {
+		DEBUG("%s:na ICMP checksum failed! drop the packet!"
+		      , __func__);
+		kfree_skb(skb);
+		return 0;
+	}
+
+	neigh = neigh_lookup(&nnd_tbl, &NIPCB(skb)->srcaddr, dev);
+	if (neigh) {
+		neigh_update(neigh, lladdr, NUD_REACHABLE,
+			     NEIGH_UPDATE_F_OVERRIDE, 0);
+		neigh_release(neigh);
+		kfree_skb(skb);
+		return 0;
+	}
+	kfree_skb(skb);
+	return -EFAULT;
+}
+
+int nndisc_rcv(struct sk_buff *skb)
+{
+	int ret = 0;
+	struct nip_icmp_hdr *hdr = nip_icmp_header(skb);
+	u8 type = hdr->nip_icmp_type;
+
+	switch (type) {
+	case NIP_ARP_NS:
+		ret = nndisc_rcv_ns(skb);
+		break;
+	case NIP_ARP_NA:
+		ret = nndisc_rcv_na(skb);
+		break;
+	default:
+		DEBUG("arp packet type error");
+	}
+
+	return ret;
+}
+
+int __init nndisc_init(void)
+{
+	neigh_table_init(NEIGH_NND_TABLE, &nnd_tbl);
+	return 0;
+}

code/linux/net/newip/protocol.c

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Huawei Device Co., Ltd.
+ *
+ * NewIP INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. NewIP INET is implemented using the  BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * NewIP INET protocol dispatch tables.
+ *
+ * Based on net/ipv6/protocol.c
+ */
+#include <net/protocol.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/spinlock.h>
+
+const struct ninet_protocol __rcu *ninet_protos[MAX_INET_PROTOS] __read_mostly;
+
+int ninet_add_protocol(const struct ninet_protocol *prot,
+		       unsigned char protocol)
+{
+	return !cmpxchg((const struct ninet_protocol **)&ninet_protos[protocol],
+			NULL, prot) ? 0 : -1;
+}
+
+int ninet_del_protocol(const struct ninet_protocol *prot,
+		       unsigned char protocol)
+{
+	int ret;
+
+	ret = (cmpxchg((const struct ninet_protocol **)&ninet_protos[protocol],
+		       prot, NULL) == prot) ? 0 : -1;
+
+	synchronize_net();
+
+	return ret;
+}
+