net neigh: neigh_delete() and neigh_add() changes

neigh_delete() and neigh_add() dont need to touch device refcount,
we hold RTNL when calling them, so device cannot disappear under us.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index b142a0d..d6996e0 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1531,6 +1531,7 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
        struct net_device *dev = NULL;
        int err = -EINVAL;
 
+       ASSERT_RTNL();
        if (nlmsg_len(nlh) < sizeof(*ndm))
                goto out;
 
@@ -1540,7 +1541,7 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
        ndm = nlmsg_data(nlh);
        if (ndm->ndm_ifindex) {
-               dev = dev_get_by_index(net, ndm->ndm_ifindex);
+               dev = __dev_get_by_index(net, ndm->ndm_ifindex);
                if (dev == NULL) {
                        err = -ENODEV;
                        goto out;
@@ -1556,34 +1557,31 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                read_unlock(&neigh_tbl_lock);
 
                if (nla_len(dst_attr) < tbl->key_len)
-                       goto out_dev_put;
+                       goto out;
 
                if (ndm->ndm_flags & NTF_PROXY) {
                        err = pneigh_delete(tbl, net, nla_data(dst_attr), dev);
-                       goto out_dev_put;
+                       goto out;
                }
 
                if (dev == NULL)
-                       goto out_dev_put;
+                       goto out;
 
                neigh = neigh_lookup(tbl, nla_data(dst_attr), dev);
                if (neigh == NULL) {
                        err = -ENOENT;
-                       goto out_dev_put;
+                       goto out;
                }
 
                err = neigh_update(neigh, NULL, NUD_FAILED,
                                   NEIGH_UPDATE_F_OVERRIDE |
                                   NEIGH_UPDATE_F_ADMIN);
                neigh_release(neigh);
-               goto out_dev_put;
+               goto out;
        }
        read_unlock(&neigh_tbl_lock);
        err = -EAFNOSUPPORT;
 
-out_dev_put:
-       if (dev)
-               dev_put(dev);
 out:
        return err;
 }
@@ -1597,6 +1595,7 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
        struct net_device *dev = NULL;
        int err;
 
+       ASSERT_RTNL();
        err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
        if (err < 0)
                goto out;
@@ -1607,14 +1606,14 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
        ndm = nlmsg_data(nlh);
        if (ndm->ndm_ifindex) {
-               dev = dev_get_by_index(net, ndm->ndm_ifindex);
+               dev = __dev_get_by_index(net, ndm->ndm_ifindex);
                if (dev == NULL) {
                        err = -ENODEV;
                        goto out;
                }
 
                if (tb[NDA_LLADDR] && nla_len(tb[NDA_LLADDR]) < dev->addr_len)
-                       goto out_dev_put;
+                       goto out;
        }
 
        read_lock(&neigh_tbl_lock);
@@ -1628,7 +1627,7 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                read_unlock(&neigh_tbl_lock);
 
                if (nla_len(tb[NDA_DST]) < tbl->key_len)
-                       goto out_dev_put;
+                       goto out;
                dst = nla_data(tb[NDA_DST]);
                lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL;
 
@@ -1641,29 +1640,29 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                                pn->flags = ndm->ndm_flags;
                                err = 0;
                        }
-                       goto out_dev_put;
+                       goto out;
                }
 
                if (dev == NULL)
-                       goto out_dev_put;
+                       goto out;
 
                neigh = neigh_lookup(tbl, dst, dev);
                if (neigh == NULL) {
                        if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
                                err = -ENOENT;
-                               goto out_dev_put;
+                               goto out;
                        }
 
                        neigh = __neigh_lookup_errno(tbl, dst, dev);
                        if (IS_ERR(neigh)) {
                                err = PTR_ERR(neigh);
-                               goto out_dev_put;
+                               goto out;
                        }
                } else {
                        if (nlh->nlmsg_flags & NLM_F_EXCL) {
                                err = -EEXIST;
                                neigh_release(neigh);
-                               goto out_dev_put;
+                               goto out;
                        }
 
                        if (!(nlh->nlmsg_flags & NLM_F_REPLACE))
@@ -1676,15 +1675,11 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                } else
                        err = neigh_update(neigh, lladdr, ndm->ndm_state, flags);
                neigh_release(neigh);
-               goto out_dev_put;
+               goto out;
        }
 
        read_unlock(&neigh_tbl_lock);
        err = -EAFNOSUPPORT;
-
-out_dev_put:
-       if (dev)
-               dev_put(dev);
 out:
        return err;
 }