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: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index d208ee9ab60af4db725d4380148406b0a561085f..ea71513fca21a0aea0dd569b482717a1b1dbe673 100644 (file)
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -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);

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 5693168e88b646b698d13386187cfcd2c207ad89..04a53a0b733d7572e9ee901321449048bb75c4c9 100644 (file)
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -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

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 4615a9b3e26ce60c7205492ce3690c92a19c53dd..236f34244dbe1f2cd2bdfaf9d4eceb0765276882 100644 (file)
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -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;
        }

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 1cbbf63a5ef79f9da29acb1e128ab3e5ec38ce35..61368186edea53841b1f00b37ddaa0d26461aee3 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -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);