netconf: add proxy-arp support

Add support to netconf to show changes to proxy-arp status on a per
interface basis via netlink in a manner similar to forwarding
and reverse path state.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 30 insertions, 12 deletions

diff --git a/include/uapi/linux/netconf.h b/include/uapi/linux/netconf.h
index 64804a798b0c..bd969d77ce52 100644
--- a/include/uapi/linux/netconf.h
+++ b/include/uapi/linux/netconf.h
@@ -14,6 +14,7 @@ enum {
         NETCONFA_FORWARDING,
         NETCONFA_RP_FILTER,
         NETCONFA_MC_FORWARDING,
+        NETCONFA_PROXY_ARP,
         __NETCONFA_MAX
 };
 #define NETCONFA_MAX    (__NETCONFA_MAX - 1)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 84956f5f0135..de03fe7002d0 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1696,6 +1696,8 @@ static int inet_netconf_msgsize_devconf(int type)
                 size += nla_total_size(4);
         if (type == -1 || type == NETCONFA_MC_FORWARDING)
                 size += nla_total_size(4);
+        if (type == -1 || type == NETCONFA_PROXY_ARP)
+                size += nla_total_size(4);
 
         return size;
 }
@@ -1732,6 +1734,10 @@ static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
             nla_put_s32(skb, NETCONFA_MC_FORWARDING,
                         IPV4_DEVCONF(*devconf, MC_FORWARDING)) < 0)
                 goto nla_put_failure;
+        if ((type == -1 || type == NETCONFA_PROXY_ARP) &&
+            nla_put_s32(skb, NETCONFA_PROXY_ARP,
+                        IPV4_DEVCONF(*devconf, PROXY_ARP)) < 0)
+                goto nla_put_failure;
 
         return nlmsg_end(skb, nlh);
 
@@ -1769,6 +1775,7 @@ static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = {
         [NETCONFA_IFINDEX]      = { .len = sizeof(int) },
         [NETCONFA_FORWARDING]   = { .len = sizeof(int) },
         [NETCONFA_RP_FILTER]    = { .len = sizeof(int) },
+        [NETCONFA_PROXY_ARP]    = { .len = sizeof(int) },
 };
 
 static int inet_netconf_get_devconf(struct sk_buff *in_skb,
@@ -1950,6 +1957,19 @@ static void inet_forward_change(struct net *net)
         }
 }
 
+static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
+{
+        if (cnf == net->ipv4.devconf_dflt)
+                return NETCONFA_IFINDEX_DEFAULT;
+        else if (cnf == net->ipv4.devconf_all)
+                return NETCONFA_IFINDEX_ALL;
+        else {
+                struct in_device *idev
+                        = container_of(cnf, struct in_device, cnf);
+                return idev->dev->ifindex;
+        }
+}
+
 static int devinet_conf_proc(struct ctl_table *ctl, int write,
                              void __user *buffer,
                              size_t *lenp, loff_t *ppos)
@@ -1962,6 +1982,7 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
                 struct ipv4_devconf *cnf = ctl->extra1;
                 struct net *net = ctl->extra2;
                 int i = (int *)ctl->data - cnf->data;
+                int ifindex;
 
                 set_bit(i, cnf->state);
 
@@ -1971,23 +1992,19 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
                     i == IPV4_DEVCONF_ROUTE_LOCALNET - 1)
                         if ((new_value == 0) && (old_value != 0))
                                 rt_cache_flush(net);
+
                 if (i == IPV4_DEVCONF_RP_FILTER - 1 &&
                     new_value != old_value) {
-                        int ifindex;
-
-                        if (cnf == net->ipv4.devconf_dflt)
-                                ifindex = NETCONFA_IFINDEX_DEFAULT;
-                        else if (cnf == net->ipv4.devconf_all)
-                                ifindex = NETCONFA_IFINDEX_ALL;
-                        else {
-                                struct in_device *idev =
-                                        container_of(cnf, struct in_device,
-                                                     cnf);
-                                ifindex = idev->dev->ifindex;
-                        }
+                        ifindex = devinet_conf_ifindex(net, cnf);
                         inet_netconf_notify_devconf(net, NETCONFA_RP_FILTER,
                                                     ifindex, cnf);
                 }
+                if (i == IPV4_DEVCONF_PROXY_ARP - 1 &&
+                    new_value != old_value) {
+                        ifindex = devinet_conf_ifindex(net, cnf);
+                        inet_netconf_notify_devconf(net, NETCONFA_PROXY_ARP,
+                                                    ifindex, cnf);
+                }
         }
 
         return ret;