ipv4: provide addr and netconf dump consistency info

This patch takes benefit of dev_addr_genid and dev_base_seq to check if a change
occurs during a netlink dump. If a change is detected, the flag NLM_F_DUMP_INTR
is set in the first message after the dump was interrupted.

Note that seq and prev_seq must be reset between each family in rtnl_dump_all()
because they are specific to each family.

Reported-by: Junwei Zhang <junwei.zhang@6wind.com>
Reported-by: Hongjun Li <hongjun.li@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 20a9f9274f3f..5d985e367535 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1499,6 +1499,8 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
                 idx = 0;
                 head = &net->dev_index_head[h];
                 rcu_read_lock();
+                cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^
+                          net->dev_base_seq;
                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
                         if (idx < s_idx)
                                 goto cont;
@@ -1519,6 +1521,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
                                         rcu_read_unlock();
                                         goto done;
                                 }
+                                nl_dump_check_consistent(cb, nlmsg_hdr(skb));
                         }
 cont:
                         idx++;
@@ -1807,6 +1810,8 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb,
                 idx = 0;
                 head = &net->dev_index_head[h];
                 rcu_read_lock();
+                cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^
+                          net->dev_base_seq;
                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
                         if (idx < s_idx)
                                 goto cont;
@@ -1824,6 +1829,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb,
                                 rcu_read_unlock();
                                 goto done;
                         }
+                        nl_dump_check_consistent(cb, nlmsg_hdr(skb));
 cont:
                         idx++;
                 }