Phonet: back-end for autoconfigured addresses

In some cases, the network device driver knows what layer-3 address the
device should have. This adds support for the Phonet stack to
automatically request from the driver and add that address to the
network device.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 42 insertions, 1 deletions

diff --git a/include/linux/phonet.h b/include/linux/phonet.h
index ee5e3c9e2bca..82b45d16e50c 100644
--- a/include/linux/phonet.h
+++ b/include/linux/phonet.h
@@ -170,4 +170,21 @@ static inline __u8 pn_sockaddr_get_resource(const struct sockaddr_pn *spn)
         return spn->spn_resource;
 }
 
+/* Phonet device ioctl requests */
+#ifdef __KERNEL__
+#define SIOCPNGAUTOCONF         (SIOCDEVPRIVATE + 0)
+
+struct if_phonet_autoconf {
+        uint8_t device;
+};
+
+struct if_phonet_req {
+        char ifr_phonet_name[16];
+        union {
+                struct if_phonet_autoconf ifru_phonet_autoconf;
+        } ifr_ifru;
+};
+#define ifr_phonet_autoconf ifr_ifru.ifru_phonet_autoconf
+#endif /* __KERNEL__ */
+
 #endif
diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index 5ae4c01e8388..2f65dcaed2fb 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -28,6 +28,7 @@
 #include <linux/netdevice.h>
 #include <linux/phonet.h>
 #include <linux/proc_fs.h>
+#include <linux/if_arp.h>
 #include <net/sock.h>
 #include <net/netns/generic.h>
 #include <net/phonet/pn_dev.h>
@@ -195,14 +196,37 @@ found:
         return err;
 }
 
+/* automatically configure a Phonet device, if supported */
+static int phonet_device_autoconf(struct net_device *dev)
+{
+        struct if_phonet_req req;
+        int ret;
+
+        if (!dev->netdev_ops->ndo_do_ioctl)
+                return -EOPNOTSUPP;
+
+        ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
+                                                SIOCPNGAUTOCONF);
+        if (ret < 0)
+                return ret;
+        return phonet_address_add(dev, req.ifr_phonet_autoconf.device);
+}
+
 /* notify Phonet of device events */
 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
                                 void *arg)
 {
         struct net_device *dev = arg;
 
-        if (what == NETDEV_UNREGISTER)
+        switch (what) {
+        case NETDEV_REGISTER:
+                if (dev->type == ARPHRD_PHONET)
+                        phonet_device_autoconf(dev);
+                break;
+        case NETDEV_UNREGISTER:
                 phonet_device_destroy(dev);
+                break;
+        }
         return 0;
 
 }