[NET]: dev: introduce generic net_device address lists

Introduce struct dev_addr_list and list maintenance functions
based on dev_mc_list and the related functions. This will be
used by follow-up patches for both multicast and secondary
unicast addresses.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 80 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 7a8f22fb4ee..aa389c77aa3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -177,6 +177,14 @@ struct netif_rx_stats
 
 DECLARE_PER_CPU(struct netif_rx_stats, netdev_rx_stat);
 
+struct dev_addr_list
+{
+        struct dev_addr_list    *next;
+        u8                      da_addr[MAX_ADDR_LEN];
+        u8                      da_addrlen;
+        int                     da_users;
+        int                     da_gusers;
+};
 
 /*
  *      We tag multicasts with these structures.
@@ -1008,6 +1016,9 @@ extern void		dev_mc_upload(struct net_device *dev);
 extern int              dev_mc_delete(struct net_device *dev, void *addr, int alen, int all);
 extern int              dev_mc_add(struct net_device *dev, void *addr, int alen, int newonly);
 extern void             dev_mc_discard(struct net_device *dev);
+extern int              __dev_addr_delete(struct dev_addr_list **list, void *addr, int alen, int all);
+extern int              __dev_addr_add(struct dev_addr_list **list, void *addr, int alen, int newonly);
+extern void             __dev_addr_discard(struct dev_addr_list **list);
 extern void             dev_set_promiscuity(struct net_device *dev, int inc);
 extern void             dev_set_allmulti(struct net_device *dev, int inc);
 extern void             netdev_state_change(struct net_device *dev);
diff --git a/net/core/dev.c b/net/core/dev.c
index a0a46e7ed13..18759ccdf21 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2553,6 +2553,75 @@ void dev_set_allmulti(struct net_device *dev, int inc)
                 dev_mc_upload(dev);
 }
 
+int __dev_addr_delete(struct dev_addr_list **list, void *addr, int alen,
+                      int glbl)
+{
+        struct dev_addr_list *da;
+
+        for (; (da = *list) != NULL; list = &da->next) {
+                if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
+                    alen == da->da_addrlen) {
+                        if (glbl) {
+                                int old_glbl = da->da_gusers;
+                                da->da_gusers = 0;
+                                if (old_glbl == 0)
+                                        break;
+                        }
+                        if (--da->da_users)
+                                return 0;
+
+                        *list = da->next;
+                        kfree(da);
+                        return 0;
+                }
+        }
+        return -ENOENT;
+}
+
+int __dev_addr_add(struct dev_addr_list **list, void *addr, int alen, int glbl)
+{
+        struct dev_addr_list *da;
+
+        for (da = *list; da != NULL; da = da->next) {
+                if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
+                    da->da_addrlen == alen) {
+                        if (glbl) {
+                                int old_glbl = da->da_gusers;
+                                da->da_gusers = 1;
+                                if (old_glbl)
+                                        return 0;
+                        }
+                        da->da_users++;
+                        return 0;
+                }
+        }
+
+        da = kmalloc(sizeof(*da), GFP_ATOMIC);
+        if (da == NULL)
+                return -ENOMEM;
+        memcpy(da->da_addr, addr, alen);
+        da->da_addrlen = alen;
+        da->da_users = 1;
+        da->da_gusers = glbl ? 1 : 0;
+        da->next = *list;
+        *list = da;
+        return 0;
+}
+
+void __dev_addr_discard(struct dev_addr_list **list)
+{
+        struct dev_addr_list *tmp;
+
+        while (*list != NULL) {
+                tmp = *list;
+                *list = tmp->next;
+                if (tmp->da_users > tmp->da_gusers)
+                        printk("__dev_addr_discard: address leakage! "
+                               "da_users=%d\n", tmp->da_users);
+                kfree(tmp);
+        }
+}
+
 unsigned dev_get_flags(const struct net_device *dev)
 {
         unsigned flags;