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 120eecc0f5a471f0157894f48ee33f1d1f6a9af5..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));