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>

1 files changed, 17 insertions, 22 deletions

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index b142a0d76072..d6996e072a41 100644
--- 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;
 }