netconf: add the handler to dump entries

It's useful to be able to get the initial state of all entries. The patch adds
the support for IPv4 and IPv6.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 138 insertions, 2 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index f678507bc829..af57bbae05b9 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1791,6 +1791,74 @@ errout:
         return err;
 }
 
+static int inet_netconf_dump_devconf(struct sk_buff *skb,
+                                     struct netlink_callback *cb)
+{
+        struct net *net = sock_net(skb->sk);
+        int h, s_h;
+        int idx, s_idx;
+        struct net_device *dev;
+        struct in_device *in_dev;
+        struct hlist_head *head;
+
+        s_h = cb->args[0];
+        s_idx = idx = cb->args[1];
+
+        for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
+                idx = 0;
+                head = &net->dev_index_head[h];
+                rcu_read_lock();
+                hlist_for_each_entry_rcu(dev, head, index_hlist) {
+                        if (idx < s_idx)
+                                goto cont;
+                        in_dev = __in_dev_get_rcu(dev);
+                        if (!in_dev)
+                                goto cont;
+
+                        if (inet_netconf_fill_devconf(skb, dev->ifindex,
+                                                      &in_dev->cnf,
+                                                      NETLINK_CB(cb->skb).portid,
+                                                      cb->nlh->nlmsg_seq,
+                                                      RTM_NEWNETCONF,
+                                                      NLM_F_MULTI,
+                                                      -1) <= 0) {
+                                rcu_read_unlock();
+                                goto done;
+                        }
+cont:
+                        idx++;
+                }
+                rcu_read_unlock();
+        }
+        if (h == NETDEV_HASHENTRIES) {
+                if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
+                                              net->ipv4.devconf_all,
+                                              NETLINK_CB(cb->skb).portid,
+                                              cb->nlh->nlmsg_seq,
+                                              RTM_NEWNETCONF, NLM_F_MULTI,
+                                              -1) <= 0)
+                        goto done;
+                else
+                        h++;
+        }
+        if (h == NETDEV_HASHENTRIES + 1) {
+                if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
+                                              net->ipv4.devconf_dflt,
+                                              NETLINK_CB(cb->skb).portid,
+                                              cb->nlh->nlmsg_seq,
+                                              RTM_NEWNETCONF, NLM_F_MULTI,
+                                              -1) <= 0)
+                        goto done;
+                else
+                        h++;
+        }
+done:
+        cb->args[0] = h;
+        cb->args[1] = idx;
+
+        return skb->len;
+}
+
 #ifdef CONFIG_SYSCTL
 
 static void devinet_copy_dflt_conf(struct net *net, int i)
@@ -2195,6 +2263,6 @@ void __init devinet_init(void)
         rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, NULL);
         rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, NULL);
         rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
-                      NULL, NULL);
+                      inet_netconf_dump_devconf, NULL);
 }
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f2c7e615f902..fa36a677490f 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -605,6 +605,74 @@ errout:
         return err;
 }
 
+static int inet6_netconf_dump_devconf(struct sk_buff *skb,
+                                      struct netlink_callback *cb)
+{
+        struct net *net = sock_net(skb->sk);
+        int h, s_h;
+        int idx, s_idx;
+        struct net_device *dev;
+        struct inet6_dev *idev;
+        struct hlist_head *head;
+
+        s_h = cb->args[0];
+        s_idx = idx = cb->args[1];
+
+        for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
+                idx = 0;
+                head = &net->dev_index_head[h];
+                rcu_read_lock();
+                hlist_for_each_entry_rcu(dev, head, index_hlist) {
+                        if (idx < s_idx)
+                                goto cont;
+                        idev = __in6_dev_get(dev);
+                        if (!idev)
+                                goto cont;
+
+                        if (inet6_netconf_fill_devconf(skb, dev->ifindex,
+                                                       &idev->cnf,
+                                                       NETLINK_CB(cb->skb).portid,
+                                                       cb->nlh->nlmsg_seq,
+                                                       RTM_NEWNETCONF,
+                                                       NLM_F_MULTI,
+                                                       -1) <= 0) {
+                                rcu_read_unlock();
+                                goto done;
+                        }
+cont:
+                        idx++;
+                }
+                rcu_read_unlock();
+        }
+        if (h == NETDEV_HASHENTRIES) {
+                if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
+                                               net->ipv6.devconf_all,
+                                               NETLINK_CB(cb->skb).portid,
+                                               cb->nlh->nlmsg_seq,
+                                               RTM_NEWNETCONF, NLM_F_MULTI,
+                                               -1) <= 0)
+                        goto done;
+                else
+                        h++;
+        }
+        if (h == NETDEV_HASHENTRIES + 1) {
+                if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
+                                               net->ipv6.devconf_dflt,
+                                               NETLINK_CB(cb->skb).portid,
+                                               cb->nlh->nlmsg_seq,
+                                               RTM_NEWNETCONF, NLM_F_MULTI,
+                                               -1) <= 0)
+                        goto done;
+                else
+                        h++;
+        }
+done:
+        cb->args[0] = h;
+        cb->args[1] = idx;
+
+        return skb->len;
+}
+
 #ifdef CONFIG_SYSCTL
 static void dev_forward_change(struct inet6_dev *idev)
 {
@@ -4940,7 +5008,7 @@ int __init addrconf_init(void)
         __rtnl_register(PF_INET6, RTM_GETANYCAST, NULL,
                         inet6_dump_ifacaddr, NULL);
         __rtnl_register(PF_INET6, RTM_GETNETCONF, inet6_netconf_get_devconf,
-                        NULL, NULL);
+                        inet6_netconf_dump_devconf, NULL);
 
         ipv6_addr_label_rtnl_register();