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Commit d7480fd3 authored by WANG Cong's avatar WANG Cong Committed by David S. Miller
Browse files

neigh: remove dynamic neigh table registration support 



Currently there are only three neigh tables in the whole kernel:
arp table, ndisc table and decnet neigh table. What's more,
we don't support registering multiple tables per family.
Therefore we can just make these tables statically built-in.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b2e2f0c7

include/net/neighbour.h

+9 −2
Original line number Diff line number Diff line
@@ -220,6 +220,13 @@ struct neigh_table { 
	struct pneigh_entry	**phash_buckets;

};



enum {

	NEIGH_ARP_TABLE = 0,

	NEIGH_ND_TABLE = 1,

	NEIGH_DN_TABLE = 2,

	NEIGH_NR_TABLES,

};



static inline int neigh_parms_family(struct neigh_parms *p)

{

	return p->tbl->family;
@@ -240,8 +247,8 @@ static inline void *neighbour_priv(const struct neighbour *n) 
#define NEIGH_UPDATE_F_ISROUTER			0x40000000

#define NEIGH_UPDATE_F_ADMIN			0x80000000



void neigh_table_init(struct neigh_table *tbl);

int neigh_table_clear(struct neigh_table *tbl);

void neigh_table_init(int index, struct neigh_table *tbl);

int neigh_table_clear(int index, struct neigh_table *tbl);

struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey,

			       struct net_device *dev);

struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net,

net/core/neighbour.c

+112 −135
Original line number Diff line number Diff line
@@ -56,7 +56,6 @@ static void __neigh_notify(struct neighbour *n, int type, int flags); 
static void neigh_update_notify(struct neighbour *neigh);

static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);



static struct neigh_table *neigh_tables;

#ifdef CONFIG_PROC_FS

static const struct file_operations neigh_stat_seq_fops;

#endif
@@ -87,13 +86,8 @@ static const struct file_operations neigh_stat_seq_fops; 
   the most complicated procedure, which we allow is dev->hard_header.

   It is supposed, that dev->hard_header is simplistic and does

   not make callbacks to neighbour tables.



   The last lock is neigh_tbl_lock. It is pure SMP lock, protecting

   list of neighbour tables. This list is used only in process context,

 */



static DEFINE_RWLOCK(neigh_tbl_lock);



static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb)

{

	kfree_skb(skb);
@@ -1520,7 +1514,9 @@ static void neigh_parms_destroy(struct neigh_parms *parms) 


static struct lock_class_key neigh_table_proxy_queue_class;



static void neigh_table_init_no_netlink(struct neigh_table *tbl)

static struct neigh_table *neigh_tables[NEIGH_NR_TABLES] __read_mostly;



void neigh_table_init(int index, struct neigh_table *tbl)

{

	unsigned long now = jiffies;

	unsigned long phsize;
@@ -1566,34 +1562,14 @@ static void neigh_table_init_no_netlink(struct neigh_table *tbl) 


	tbl->last_flush = now;

	tbl->last_rand	= now + tbl->parms.reachable_time * 20;

}



void neigh_table_init(struct neigh_table *tbl)

{

	struct neigh_table *tmp;



	neigh_table_init_no_netlink(tbl);

	write_lock(&neigh_tbl_lock);

	for (tmp = neigh_tables; tmp; tmp = tmp->next) {

		if (tmp->family == tbl->family)

			break;

	}

	tbl->next	= neigh_tables;

	neigh_tables	= tbl;

	write_unlock(&neigh_tbl_lock);



	if (unlikely(tmp)) {

		pr_err("Registering multiple tables for family %d\n",

		       tbl->family);

		dump_stack();

	}

	neigh_tables[index] = tbl;

}

EXPORT_SYMBOL(neigh_table_init);



int neigh_table_clear(struct neigh_table *tbl)

int neigh_table_clear(int index, struct neigh_table *tbl)

{

	struct neigh_table **tp;



	neigh_tables[index] = NULL;

	/* It is not clean... Fix it to unload IPv6 module safely */

	cancel_delayed_work_sync(&tbl->gc_work);

	del_timer_sync(&tbl->proxy_timer);
@@ -1601,14 +1577,6 @@ int neigh_table_clear(struct neigh_table *tbl) 
	neigh_ifdown(tbl, NULL);

	if (atomic_read(&tbl->entries))

		pr_crit("neighbour leakage\n");

	write_lock(&neigh_tbl_lock);

	for (tp = &neigh_tables; *tp; tp = &(*tp)->next) {

		if (*tp == tbl) {

			*tp = tbl->next;

			break;

		}

	}

	write_unlock(&neigh_tbl_lock);



	call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu,

		 neigh_hash_free_rcu);
@@ -1626,12 +1594,32 @@ int neigh_table_clear(struct neigh_table *tbl) 
}

EXPORT_SYMBOL(neigh_table_clear);



static struct neigh_table *neigh_find_table(int family)

{

	struct neigh_table *tbl = NULL;



	switch (family) {

	case AF_INET:

		tbl = neigh_tables[NEIGH_ARP_TABLE];

		break;

	case AF_INET6:

		tbl = neigh_tables[NEIGH_ND_TABLE];

		break;

	case AF_DECnet:

		tbl = neigh_tables[NEIGH_DN_TABLE];

		break;

	}



	return tbl;

}



static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh)

{

	struct net *net = sock_net(skb->sk);

	struct ndmsg *ndm;

	struct nlattr *dst_attr;

	struct neigh_table *tbl;

	struct neighbour *neigh;

	struct net_device *dev = NULL;

	int err = -EINVAL;
@@ -1652,13 +1640,9 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh) 
		}

	}



	read_lock(&neigh_tbl_lock);

	for (tbl = neigh_tables; tbl; tbl = tbl->next) {

		struct neighbour *neigh;



		if (tbl->family != ndm->ndm_family)

			continue;

		read_unlock(&neigh_tbl_lock);

	tbl = neigh_find_table(ndm->ndm_family);

	if (tbl == NULL)

		return -EAFNOSUPPORT;



	if (nla_len(dst_attr) < tbl->key_len)

		goto out;
@@ -1681,10 +1665,6 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh) 
			   NEIGH_UPDATE_F_OVERRIDE |

			   NEIGH_UPDATE_F_ADMIN);

	neigh_release(neigh);

		goto out;

	}

	read_unlock(&neigh_tbl_lock);

	err = -EAFNOSUPPORT;



out:

	return err;
@@ -1692,11 +1672,14 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh) 


static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)

{

	int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;

	struct net *net = sock_net(skb->sk);

	struct ndmsg *ndm;

	struct nlattr *tb[NDA_MAX+1];

	struct neigh_table *tbl;

	struct net_device *dev = NULL;

	struct neighbour *neigh;

	void *dst, *lladdr;

	int err;



	ASSERT_RTNL();
@@ -1720,15 +1703,9 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh) 
			goto out;

	}



	read_lock(&neigh_tbl_lock);

	for (tbl = neigh_tables; tbl; tbl = tbl->next) {

		int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;

		struct neighbour *neigh;

		void *dst, *lladdr;



		if (tbl->family != ndm->ndm_family)

			continue;

		read_unlock(&neigh_tbl_lock);

	tbl = neigh_find_table(ndm->ndm_family);

	if (tbl == NULL)

		return -EAFNOSUPPORT;



	if (nla_len(tb[NDA_DST]) < tbl->key_len)

		goto out;
@@ -1779,11 +1756,7 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh) 
	} else

		err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);

	neigh_release(neigh);

		goto out;

	}



	read_unlock(&neigh_tbl_lock);

	err = -EAFNOSUPPORT;

out:

	return err;

}
@@ -1982,7 +1955,8 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) 
	struct neigh_table *tbl;

	struct ndtmsg *ndtmsg;

	struct nlattr *tb[NDTA_MAX+1];

	int err;

	bool found = false;

	int err, tidx;



	err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,

			  nl_neightbl_policy);
@@ -1995,20 +1969,22 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) 
	}



	ndtmsg = nlmsg_data(nlh);

	read_lock(&neigh_tbl_lock);

	for (tbl = neigh_tables; tbl; tbl = tbl->next) {



	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {

		tbl = neigh_tables[tidx];

		if (!tbl)

			continue;

		if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family)

			continue;



		if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0)

		if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0) {

			found = true;

			break;

		}



	if (tbl == NULL) {

		err = -ENOENT;

		goto errout_locked;

	}



	if (!found)

		return -ENOENT;



	/*

	 * We acquire tbl->lock to be nice to the periodic timers and

	 * make sure they always see a consistent set of values.
@@ -2118,8 +2094,6 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) 


errout_tbl_lock:

	write_unlock_bh(&tbl->lock);

errout_locked:

	read_unlock(&neigh_tbl_lock);

errout:

	return err;

}
@@ -2134,10 +2108,13 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 


	family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;



	read_lock(&neigh_tbl_lock);

	for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) {

	for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) {

		struct neigh_parms *p;



		tbl = neigh_tables[tidx];

		if (!tbl)

			continue;



		if (tidx < tbl_skip || (family && tbl->family != family))

			continue;
@@ -2168,7 +2145,6 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 
		neigh_skip = 0;

	}

out:

	read_unlock(&neigh_tbl_lock);

	cb->args[0] = tidx;

	cb->args[1] = nidx;
@@ -2351,7 +2327,6 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 
	int proxy = 0;

	int err;



	read_lock(&neigh_tbl_lock);

	family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;



	/* check for full ndmsg structure presence, family member is
@@ -2363,8 +2338,11 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 


	s_t = cb->args[0];



	for (tbl = neigh_tables, t = 0; tbl;

	     tbl = tbl->next, t++) {

	for (t = 0; t < NEIGH_NR_TABLES; t++) {

		tbl = neigh_tables[t];



		if (!tbl)

			continue;

		if (t < s_t || (family && tbl->family != family))

			continue;

		if (t > s_t)
@@ -2377,7 +2355,6 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) 
		if (err < 0)

			break;

	}

	read_unlock(&neigh_tbl_lock);



	cb->args[0] = t;

	return skb->len;

net/decnet/dn_neigh.c

+2 −2
Original line number Diff line number Diff line
@@ -591,7 +591,7 @@ static const struct file_operations dn_neigh_seq_fops = { 


void __init dn_neigh_init(void)

{

	neigh_table_init(&dn_neigh_table);

	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);

	proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,

		    &dn_neigh_seq_fops);

}
@@ -599,5 +599,5 @@ void __init dn_neigh_init(void) 
void __exit dn_neigh_cleanup(void)

{

	remove_proc_entry("decnet_neigh", init_net.proc_net);

	neigh_table_clear(&dn_neigh_table);

	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);

}

net/ipv4/arp.c

+1 −1
Original line number Diff line number Diff line
@@ -1292,7 +1292,7 @@ static int arp_proc_init(void); 


void __init arp_init(void)

{

	neigh_table_init(&arp_tbl);

	neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);



	dev_add_pack(&arp_packet_type);

	arp_proc_init();

net/ipv6/ndisc.c

+2 −2
Original line number Diff line number Diff line
@@ -1763,7 +1763,7 @@ int __init ndisc_init(void) 
	/*

	 * Initialize the neighbour table

	 */

	neigh_table_init(&nd_tbl);

	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);



#ifdef CONFIG_SYSCTL

	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
@@ -1796,6 +1796,6 @@ void ndisc_cleanup(void) 
#ifdef CONFIG_SYSCTL

	neigh_sysctl_unregister(&nd_tbl.parms);

#endif

	neigh_table_clear(&nd_tbl);

	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);

	unregister_pernet_subsys(&ndisc_net_ops);

}