ipv6: provide addr and netconf dump consistency info

This patch adds a dev_addr_genid for IPv6. The goal is to use it, combined with
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 only dump of unicast addresses is checked (multicast and anycast are
not checked).

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/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 1242f37..005e2c2 100644 (file)
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -71,6 +71,7 @@ struct netns_ipv6 {
        struct fib_rules_ops    *mr6_rules_ops;
 #endif
 #endif
+       atomic_t                dev_addr_genid;
 };
 
 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 15794fd..1b9f4f2 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -621,6 +621,8 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
                idx = 0;
                head = &net->dev_index_head[h];
                rcu_read_lock();
+               cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^
+                         net->dev_base_seq;
                hlist_for_each_entry_rcu(dev, head, index_hlist) {
                        if (idx < s_idx)
                                goto cont;
@@ -638,6 +640,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
                                rcu_read_unlock();
                                goto done;
                        }
+                       nl_dump_check_consistent(cb, nlmsg_hdr(skb));
 cont:
                        idx++;
                }
@@ -3874,6 +3877,7 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
                                                NLM_F_MULTI);
                        if (err <= 0)
                                break;
+                       nl_dump_check_consistent(cb, nlmsg_hdr(skb));
                }
                break;
        }
@@ -3931,6 +3935,7 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
        s_ip_idx = ip_idx = cb->args[2];
 
        rcu_read_lock();
+       cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^ net->dev_base_seq;
        for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
                idx = 0;
                head = &net->dev_index_head[h];
@@ -4407,6 +4412,8 @@ errout:
 
 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
 {
+       struct net *net = dev_net(ifp->idev->dev);
+
        inet6_ifa_notify(event ? : RTM_NEWADDR, ifp);
 
        switch (event) {
@@ -4432,6 +4439,7 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
                        dst_free(&ifp->rt->dst);
                break;
        }
+       atomic_inc(&net->ipv6.dev_addr_genid);
 }
 
 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)