Commit bfd0aeac authored by Nikolay Aleksandrov's avatar Nikolay Aleksandrov Committed by David S. Miller
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bridge: fdb: converge fdb searching functions into one 



Before this patch we had 3 different fdb searching functions which was
confusing. This patch reduces all of them to one - fdb_find_rcu(), and
two flavors: br_fdb_find() which requires hash_lock and br_fdb_find_rcu
which requires RCU. This makes it clear what needs to be used, we also
remove two abusers of __br_fdb_get which called it under hash_lock and
replace them with br_fdb_find().

Signed-off-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 91eaa475

net/bridge/br_device.c

+1 −1
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 
			br_multicast_flood(mdst, skb, false, true);

		else

			br_flood(br, skb, BR_PKT_MULTICAST, false, true);

	} else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) {

	} else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {

		br_forward(dst->dst, skb, false, true);

	} else {

		br_flood(br, skb, BR_PKT_UNICAST, false, true);

net/bridge/br_fdb.c

+48 −65
Original line number Diff line number Diff line
@@ -28,9 +28,6 @@ 
#include "br_private.h"



static struct kmem_cache *br_fdb_cache __read_mostly;

static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,

					     const unsigned char *addr,

					     __u16 vid);

static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,

		      const unsigned char *addr, u16 vid);

static void fdb_notify(struct net_bridge *br,
@@ -86,6 +83,43 @@ static void fdb_rcu_free(struct rcu_head *head) 
	kmem_cache_free(br_fdb_cache, ent);

}



static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,

						 const unsigned char *addr,

						 __u16 vid)

{

	struct net_bridge_fdb_entry *f;



	hlist_for_each_entry_rcu(f, head, hlist)

		if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)

			break;



	return f;

}



/* requires bridge hash_lock */

static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,

						const unsigned char *addr,

						__u16 vid)

{

	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];

	struct net_bridge_fdb_entry *fdb;



	rcu_read_lock();

	fdb = fdb_find_rcu(head, addr, vid);

	rcu_read_unlock();



	return fdb;

}



struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,

					     const unsigned char *addr,

					     __u16 vid)

{

	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];



	return fdb_find_rcu(head, addr, vid);

}



/* When a static FDB entry is added, the mac address from the entry is

 * added to the bridge private HW address list and all required ports

 * are then updated with the new information.
@@ -198,11 +232,10 @@ void br_fdb_find_delete_local(struct net_bridge *br, 
			      const struct net_bridge_port *p,

			      const unsigned char *addr, u16 vid)

{

	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];

	struct net_bridge_fdb_entry *f;



	spin_lock_bh(&br->hash_lock);

	f = fdb_find(head, addr, vid);

	f = br_fdb_find(br, addr, vid);

	if (f && f->is_local && !f->added_by_user && f->dst == p)

		fdb_delete_local(br, p, f);

	spin_unlock_bh(&br->hash_lock);
@@ -266,7 +299,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) 
	spin_lock_bh(&br->hash_lock);



	/* If old entry was unassociated with any port, then delete it. */

	f = __br_fdb_get(br, br->dev->dev_addr, 0);

	f = br_fdb_find(br, br->dev->dev_addr, 0);

	if (f && f->is_local && !f->dst && !f->added_by_user)

		fdb_delete_local(br, NULL, f);
@@ -281,7 +314,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) 
	list_for_each_entry(v, &vg->vlan_list, vlist) {

		if (!br_vlan_should_use(v))

			continue;

		f = __br_fdb_get(br, br->dev->dev_addr, v->vid);

		f = br_fdb_find(br, br->dev->dev_addr, v->vid);

		if (f && f->is_local && !f->dst && !f->added_by_user)

			fdb_delete_local(br, NULL, f);

		fdb_insert(br, NULL, newaddr, v->vid);
@@ -380,24 +413,6 @@ void br_fdb_delete_by_port(struct net_bridge *br, 
	spin_unlock_bh(&br->hash_lock);

}



/* No locking or refcounting, assumes caller has rcu_read_lock */

struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,

					  const unsigned char *addr,

					  __u16 vid)

{

	struct net_bridge_fdb_entry *fdb;



	hlist_for_each_entry_rcu(fdb,

				&br->hash[br_mac_hash(addr, vid)], hlist) {

		if (ether_addr_equal(fdb->addr.addr, addr) &&

		    fdb->vlan_id == vid) {

			return fdb;

		}

	}



	return NULL;

}



#if IS_ENABLED(CONFIG_ATM_LANE)

/* Interface used by ATM LANE hook to test

 * if an addr is on some other bridge port */
@@ -412,7 +427,7 @@ int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) 
	if (!port)

		ret = 0;

	else {

		fdb = __br_fdb_get(port->br, addr, 0);

		fdb = br_fdb_find_rcu(port->br, addr, 0);

		ret = fdb && fdb->dst && fdb->dst->dev != dev &&

			fdb->dst->state == BR_STATE_FORWARDING;

	}
@@ -474,34 +489,6 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf, 
	return num;

}



static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,

					     const unsigned char *addr,

					     __u16 vid)

{

	struct net_bridge_fdb_entry *fdb;



	hlist_for_each_entry(fdb, head, hlist) {

		if (ether_addr_equal(fdb->addr.addr, addr) &&

		    fdb->vlan_id == vid)

			return fdb;

	}

	return NULL;

}



static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,

						 const unsigned char *addr,

						 __u16 vid)

{

	struct net_bridge_fdb_entry *fdb;



	hlist_for_each_entry_rcu(fdb, head, hlist) {

		if (ether_addr_equal(fdb->addr.addr, addr) &&

		    fdb->vlan_id == vid)

			return fdb;

	}

	return NULL;

}



static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,

					       struct net_bridge_port *source,

					       const unsigned char *addr,
@@ -535,7 +522,7 @@ static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, 
	if (!is_valid_ether_addr(addr))

		return -EINVAL;



	fdb = fdb_find(head, addr, vid);

	fdb = br_fdb_find(br, addr, vid);

	if (fdb) {

		/* it is okay to have multiple ports with same

		 * address, just use the first one.
@@ -608,7 +595,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, 
		}

	} else {

		spin_lock(&br->hash_lock);

		if (likely(!fdb_find(head, addr, vid))) {

		if (likely(!fdb_find_rcu(head, addr, vid))) {

			fdb = fdb_create(head, source, addr, vid, 0, 0);

			if (fdb) {

				if (unlikely(added_by_user))
@@ -792,7 +779,7 @@ static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, 
		return -EINVAL;

	}



	fdb = fdb_find(head, addr, vid);

	fdb = br_fdb_find(br, addr, vid);

	if (fdb == NULL) {

		if (!(flags & NLM_F_CREATE))

			return -ENOENT;
@@ -942,10 +929,9 @@ out: 
static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,

			      u16 vid)

{

	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];

	struct net_bridge_fdb_entry *fdb;



	fdb = fdb_find(head, addr, vid);

	fdb = br_fdb_find(br, addr, vid);

	if (!fdb)

		return -ENOENT;
@@ -969,10 +955,9 @@ static int fdb_delete_by_addr_and_port(struct net_bridge_port *p, 
				       const u8 *addr, u16 vlan)

{

	struct net_bridge *br = p->br;

	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];

	struct net_bridge_fdb_entry *fdb;



	fdb = fdb_find(head, addr, vlan);

	fdb = br_fdb_find(br, addr, vlan);

	if (!fdb || fdb->dst != p)

		return -ENOENT;
@@ -1117,7 +1102,7 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, 
	spin_lock_bh(&br->hash_lock);



	head = &br->hash[br_mac_hash(addr, vid)];

	fdb = fdb_find(head, addr, vid);

	fdb = br_fdb_find(br, addr, vid);

	if (!fdb) {

		fdb = fdb_create(head, p, addr, vid, 0, 0);

		if (!fdb) {
@@ -1145,15 +1130,13 @@ err_unlock: 
int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,

			      const unsigned char *addr, u16 vid)

{

	struct hlist_head *head;

	struct net_bridge_fdb_entry *fdb;

	int err = 0;



	ASSERT_RTNL();

	spin_lock_bh(&br->hash_lock);



	head = &br->hash[br_mac_hash(addr, vid)];

	fdb = fdb_find(head, addr, vid);

	fdb = br_fdb_find(br, addr, vid);

	if (fdb && fdb->added_by_external_learn)

		fdb_delete(br, fdb);

	else

net/bridge/br_input.c

+2 −2
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, 
			return;

		}



		f = __br_fdb_get(br, n->ha, vid);

		f = br_fdb_find_rcu(br, n->ha, vid);

		if (f && ((p->flags & BR_PROXYARP) ||

			  (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) {

			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
@@ -189,7 +189,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb 
		}

		break;

	case BR_PKT_UNICAST:

		dst = __br_fdb_get(br, dest, vid);

		dst = br_fdb_find_rcu(br, dest, vid);

	default:

		break;

	}

net/bridge/br_private.h

+3 −2
Original line number Diff line number Diff line
@@ -507,8 +507,9 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr); 
void br_fdb_cleanup(struct work_struct *work);

void br_fdb_delete_by_port(struct net_bridge *br,

			   const struct net_bridge_port *p, u16 vid, int do_all);

struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,

					  const unsigned char *addr, __u16 vid);

struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,

					     const unsigned char *addr,

					     __u16 vid);

int br_fdb_test_addr(struct net_device *dev, unsigned char *addr);

int br_fdb_fillbuf(struct net_bridge *br, void *buf, unsigned long count,

		   unsigned long off);

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