rtnetlink: Warn when interface's information won't fit in our packet

[karo-tx-linux.git] / net / core / rtnetlink.c

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 048dc8d183aa9f9f105c0d4615b03d8ebd75931b..68867bf44cbcfef7cb10b5b2cd5321f9a106f1a7 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1130,6 +1130,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
        struct hlist_head *head;
        struct nlattr *tb[IFLA_MAX+1];
        u32 ext_filter_mask = 0;
+       int err;
 
        s_h = cb->args[0];
        s_idx = cb->args[1];
@@ -1150,11 +1151,17 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
                hlist_for_each_entry_rcu(dev, head, index_hlist) {
                        if (idx < s_idx)
                                goto cont;
-                       if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
-                                            NETLINK_CB(cb->skb).portid,
-                                            cb->nlh->nlmsg_seq, 0,
-                                            NLM_F_MULTI,
-                                            ext_filter_mask) <= 0)
+                       err = rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
+                                              NETLINK_CB(cb->skb).portid,
+                                              cb->nlh->nlmsg_seq, 0,
+                                              NLM_F_MULTI,
+                                              ext_filter_mask);
+                       /* If we ran out of room on the first message,
+                        * we're in trouble
+                        */
+                       WARN_ON((err == -EMSGSIZE) && (skb->len == 0));
+
+                       if (err <= 0)
                                goto out;
 
                        nl_dump_check_consistent(cb, nlmsg_hdr(skb));
@@ -1963,16 +1970,21 @@ replay:
 
                dev->ifindex = ifm->ifi_index;
 
-               if (ops->newlink)
+               if (ops->newlink) {
                        err = ops->newlink(net, dev, tb, data);
-               else
+                       /* Drivers should call free_netdev() in ->destructor
+                        * and unregister it on failure so that device could be
+                        * finally freed in rtnl_unlock.
+                        */
+                       if (err < 0)
+                               goto out;
+               } else {
                        err = register_netdevice(dev);
-
-               if (err < 0) {
-                       free_netdev(dev);
-                       goto out;
+                       if (err < 0) {
+                               free_netdev(dev);
+                               goto out;
+                       }
                }
-
                err = rtnl_configure_link(dev, ifm);
                if (err < 0)
                        unregister_netdevice(dev);
@@ -2116,12 +2128,13 @@ EXPORT_SYMBOL(rtmsg_ifinfo);
 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)
+                                  int type, unsigned int flags,
+                                  int nlflags)
 {
        struct nlmsghdr *nlh;
        struct ndmsg *ndm;
 
-       nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), NLM_F_MULTI);
+       nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), nlflags);
        if (!nlh)
                return -EMSGSIZE;
 
@@ -2159,7 +2172,7 @@ static void rtnl_fdb_notify(struct net_device *dev, u8 *addr, int type)
        if (!skb)
                goto errout;
 
-       err = nlmsg_populate_fdb_fill(skb, dev, addr, 0, 0, type, NTF_SELF);
+       err = nlmsg_populate_fdb_fill(skb, dev, addr, 0, 0, type, NTF_SELF, 0);
        if (err < 0) {
                kfree_skb(skb);
                goto errout;
@@ -2384,7 +2397,8 @@ static int nlmsg_populate_fdb(struct sk_buff *skb,
 
                err = nlmsg_populate_fdb_fill(skb, dev, ha->addr,
                                              portid, seq,
-                                             RTM_NEWNEIGH, NTF_SELF);
+                                             RTM_NEWNEIGH, NTF_SELF,
+                                             NLM_F_MULTI);
                if (err < 0)
                        return err;
 skip: