net: add fdb generic dump routine

This adds a generic dump routine drivers can call. It
should be sufficient to handle any bridging model that
uses the unicast address list. This should be most SR-IOV
enabled NICs.

v2: return error on nlmsg_put and use -EMSGSIZE instead
    of -ENOMEM this is inline other usages

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b348b7fbf53a761b6b931d436b4a82938b62f165..e8488c7b092ce2066e5c4092ff43419bd8caa425 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1980,6 +1980,37 @@ errout:
                rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 }
 
+static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
+                                  struct net_device *dev,
+                                  u8 *addr, u32 pid, u32 seq,
+                                  int type, unsigned int flags)
+{
+       struct nlmsghdr *nlh;
+       struct ndmsg *ndm;
+
+       nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), NLM_F_MULTI);
+       if (!nlh)
+               return -EMSGSIZE;
+
+       ndm = nlmsg_data(nlh);
+       ndm->ndm_family  = AF_BRIDGE;
+       ndm->ndm_pad1    = 0;
+       ndm->ndm_pad2    = 0;
+       ndm->ndm_flags   = flags;
+       ndm->ndm_type    = 0;
+       ndm->ndm_ifindex = dev->ifindex;
+       ndm->ndm_state   = NUD_PERMANENT;
+
+       if (nla_put(skb, NDA_LLADDR, ETH_ALEN, addr))
+               goto nla_put_failure;
+
+       return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+       nlmsg_cancel(skb, nlh);
+       return -EMSGSIZE;
+}
+
 static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
        struct net *net = sock_net(skb->sk);
@@ -2101,6 +2132,59 @@ out:
        return err;
 }
 
+static int nlmsg_populate_fdb(struct sk_buff *skb,
+                             struct netlink_callback *cb,
+                             struct net_device *dev,
+                             int *idx,
+                             struct netdev_hw_addr_list *list)
+{
+       struct netdev_hw_addr *ha;
+       int err;
+       u32 pid, seq;
+
+       pid = NETLINK_CB(cb->skb).pid;
+       seq = cb->nlh->nlmsg_seq;
+
+       list_for_each_entry(ha, &list->list, list) {
+               if (*idx < cb->args[0])
+                       goto skip;
+
+               err = nlmsg_populate_fdb_fill(skb, dev, ha->addr,
+                                             pid, seq, 0, NTF_SELF);
+               if (err < 0)
+                       return err;
+skip:
+               *idx += 1;
+       }
+       return 0;
+}
+
+/**
+ * ndo_dflt_fdb_dump: default netdevice operation to dump an FDB table.
+ * @nlh: netlink message header
+ * @dev: netdevice
+ *
+ * Default netdevice operation to dump the existing unicast address list.
+ * Returns zero on success.
+ */
+int ndo_dflt_fdb_dump(struct sk_buff *skb,
+                     struct netlink_callback *cb,
+                     struct net_device *dev,
+                     int idx)
+{
+       int err;
+
+       netif_addr_lock_bh(dev);
+       err = nlmsg_populate_fdb(skb, cb, dev, &idx, &dev->uc);
+       if (err)
+               goto out;
+       nlmsg_populate_fdb(skb, cb, dev, &idx, &dev->mc);
+out:
+       netif_addr_unlock_bh(dev);
+       return idx;
+}
+EXPORT_SYMBOL(ndo_dflt_fdb_dump);
+
 static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
        int idx = 0;