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>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 751f124..aeb8131 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1929,8 +1929,11 @@
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;
}
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 20a9f92..5d985e3 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1499,6 +1499,8 @@
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 @@
rcu_read_unlock();
goto done;
}
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
}
cont:
idx++;
@@ -1807,6 +1810,8 @@
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 @@
rcu_read_unlock();
goto done;
}
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
cont:
idx++;
}