net: add dev_uc_sync_multiple() and dev_mc_sync_multiple() api

The current implementation of dev_uc_sync/unsync() assumes that there is
a strict 1-to-1 relationship between the source and destination of the sync.
In other words, once an address has been synced to a destination device, it
will not be synced to any other device through the sync API.
However, there are some virtual devices that aggreate a number of lower
devices and need to sync addresses to all of them.  The current
API falls short there.

This patch introduces a new dev_uc_sync_multiple() api that can be called
in the above circumstances and allows sync to work for every invocation.

CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 171 insertions, 42 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 53d3939358a7..623b57b52195 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -209,6 +209,7 @@ struct netdev_hw_addr {
 #define NETDEV_HW_ADDR_T_UNICAST        4
 #define NETDEV_HW_ADDR_T_MULTICAST      5
         bool                    global_use;
+        int                     sync_cnt;
         int                     refcount;
         int                     synced;
         struct rcu_head         rcu_head;
@@ -2627,6 +2628,7 @@ extern int dev_uc_add(struct net_device *dev, const unsigned char *addr);
 extern int dev_uc_add_excl(struct net_device *dev, const unsigned char *addr);
 extern int dev_uc_del(struct net_device *dev, const unsigned char *addr);
 extern int dev_uc_sync(struct net_device *to, struct net_device *from);
+extern int dev_uc_sync_multiple(struct net_device *to, struct net_device *from);
 extern void dev_uc_unsync(struct net_device *to, struct net_device *from);
 extern void dev_uc_flush(struct net_device *dev);
 extern void dev_uc_init(struct net_device *dev);
@@ -2638,6 +2640,7 @@ extern int dev_mc_add_excl(struct net_device *dev, const unsigned char *addr);
 extern int dev_mc_del(struct net_device *dev, const unsigned char *addr);
 extern int dev_mc_del_global(struct net_device *dev, const unsigned char *addr);
 extern int dev_mc_sync(struct net_device *to, struct net_device *from);
+extern int dev_mc_sync_multiple(struct net_device *to, struct net_device *from);
 extern void dev_mc_unsync(struct net_device *to, struct net_device *from);
 extern void dev_mc_flush(struct net_device *dev);
 extern void dev_mc_init(struct net_device *dev);
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index abdc9e6ef33e..c013f38482a1 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -22,7 +22,8 @@
 
 static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
                                const unsigned char *addr, int addr_len,
-                               unsigned char addr_type, bool global)
+                               unsigned char addr_type, bool global,
+                               bool sync)
 {
         struct netdev_hw_addr *ha;
         int alloc_size;
@@ -37,7 +38,7 @@ static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
         ha->type = addr_type;
         ha->refcount = 1;
         ha->global_use = global;
-        ha->synced = 0;
+        ha->synced = sync;
         list_add_tail_rcu(&ha->list, &list->list);
         list->count++;
 
@@ -46,7 +47,7 @@ static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
 
 static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
                             const unsigned char *addr, int addr_len,
-                            unsigned char addr_type, bool global)
+                            unsigned char addr_type, bool global, bool sync)
 {
         struct netdev_hw_addr *ha;
 
@@ -63,43 +64,62 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
                                 else
                                         ha->global_use = true;
                         }
+                        if (sync) {
+                                if (ha->synced)
+                                        return 0;
+                                else
+                                        ha->synced = true;
+                        }
                         ha->refcount++;
                         return 0;
                 }
         }
 
-        return __hw_addr_create_ex(list, addr, addr_len, addr_type, global);
+        return __hw_addr_create_ex(list, addr, addr_len, addr_type, global,
+                                   sync);
 }
 
 static int __hw_addr_add(struct netdev_hw_addr_list *list,
                          const unsigned char *addr, int addr_len,
                          unsigned char addr_type)
 {
-        return __hw_addr_add_ex(list, addr, addr_len, addr_type, false);
+        return __hw_addr_add_ex(list, addr, addr_len, addr_type, false, false);
+}
+
+static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
+                               struct netdev_hw_addr *ha, bool global,
+                               bool sync)
+{
+        if (global && !ha->global_use)
+                return -ENOENT;
+
+        if (sync && !ha->synced)
+                return -ENOENT;
+
+        if (global)
+                ha->global_use = false;
+
+        if (sync)
+                ha->synced = false;
+
+        if (--ha->refcount)
+                return 0;
+        list_del_rcu(&ha->list);
+        kfree_rcu(ha, rcu_head);
+        list->count--;
+        return 0;
 }
 
 static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
                             const unsigned char *addr, int addr_len,
-                            unsigned char addr_type, bool global)
+                            unsigned char addr_type, bool global, bool sync)
 {
         struct netdev_hw_addr *ha;
 
         list_for_each_entry(ha, &list->list, list) {
                 if (!memcmp(ha->addr, addr, addr_len) &&
-                    (ha->type == addr_type || !addr_type)) {
-                        if (global) {
-                                if (!ha->global_use)
-                                        break;
-                                else
-                                        ha->global_use = false;
-                        }
-                        if (--ha->refcount)
-                                return 0;
-                        list_del_rcu(&ha->list);
-                        kfree_rcu(ha, rcu_head);
-                        list->count--;
-                        return 0;
-                }
+                    (ha->type == addr_type || !addr_type))
+                        return __hw_addr_del_entry(list, ha, global, sync);
         }
         return -ENOENT;
 }
@@ -108,7 +128,57 @@ static int __hw_addr_del(struct netdev_hw_addr_list *list,
                          const unsigned char *addr, int addr_len,
                          unsigned char addr_type)
 {
-        return __hw_addr_del_ex(list, addr, addr_len, addr_type, false);
+        return __hw_addr_del_ex(list, addr, addr_len, addr_type, false, false);
+}
+
+static int __hw_addr_sync_one(struct netdev_hw_addr_list *to_list,
+                               struct netdev_hw_addr *ha,
+                               int addr_len)
+{
+        int err;
+
+        err = __hw_addr_add_ex(to_list, ha->addr, addr_len, ha->type,
+                               false, true);
+        if (err)
+                return err;
+        ha->sync_cnt++;
+        ha->refcount++;
+
+        return 0;
+}
+
+static void __hw_addr_unsync_one(struct netdev_hw_addr_list *to_list,