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, 4 insertions, 1 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 751f1244b648..aeb81316a704 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1929,8 +1929,11 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
                 if (rtnl_msg_handlers[idx] == NULL ||
                     rtnl_msg_handlers[idx][type].dumpit == NULL)
                         continue;
-                if (idx > s_idx)
+                if (idx > s_idx) {
                         memset(&cb->args[0], 0, sizeof(cb->args));
+                        cb->prev_seq = 0;
+                        cb->seq = 0;
+                }
                 if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
                         break;
         }