net: Add support for filtering neigh dump by device index

Add support for filtering neighbor dumps by device by adding the
NDA_IFINDEX attribute to the dump request.

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

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 8c57fdf..1aa8437 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2249,6 +2249,14 @@ static bool neigh_master_filtered(struct net_device *dev, int master_idx)
        return false;
 }
 
+static bool neigh_ifindex_filtered(struct net_device *dev, int filter_idx)
+{
+       if (filter_idx && dev->ifindex != filter_idx)
+               return true;
+
+       return false;
+}
+
 static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
                            struct netlink_callback *cb)
 {
@@ -2259,16 +2267,19 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
        int rc, h, s_h = cb->args[1];
        int idx, s_idx = idx = cb->args[2];
        struct neigh_hash_table *nht;
-       int filter_master_idx = 0;
+       int filter_master_idx = 0, filter_idx = 0;
        unsigned int flags = NLM_F_MULTI;
        int err;
 
        err = nlmsg_parse(nlh, sizeof(struct ndmsg), tb, NDA_MAX, NULL);
        if (!err) {
+               if (tb[NDA_IFINDEX])
+                       filter_idx = nla_get_u32(tb[NDA_IFINDEX]);
+
                if (tb[NDA_MASTER])
                        filter_master_idx = nla_get_u32(tb[NDA_MASTER]);
 
-               if (filter_master_idx)
+               if (filter_idx || filter_master_idx)
                        flags |= NLM_F_DUMP_FILTERED;
        }
 
@@ -2283,6 +2294,8 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,
                     n = rcu_dereference_bh(n->next)) {
                        if (!net_eq(dev_net(n->dev), net))
                                continue;
+                       if (neigh_ifindex_filtered(n->dev, filter_idx))
+                               continue;
                        if (neigh_master_filtered(n->dev, filter_master_idx))
                                continue;
                        if (idx < s_idx)