tun: send netlink notification when the device is modified

I added dumping of link information about tun devices over netlink in
commit 631b92c16587 ("tun: export flags, uid, gid, queue information
over netlink"), but didn't add the missing netlink notifications when
the device's exported properties change.

This patch adds notifications when owner/group or flags are modified,
when queues are attached/detached, and when a tun fd is closed.

Reported-by: Thomas Haller <thaller@redhat.com>
Fixes: 631b92c16587 ("tun: export flags, uid, gid, queue information over netlink")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index c9e68fd76a372515ac02ed0c2816bdbeeaaaa4b0..28583aa0c17df6fdbeb4f30625f258dcd69855d0 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -743,8 +743,15 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 
 static void tun_detach(struct tun_file *tfile, bool clean)
 {
+       struct tun_struct *tun;
+       struct net_device *dev;
+
        rtnl_lock();
+       tun = rtnl_dereference(tfile->tun);
+       dev = tun ? tun->dev : NULL;
        __tun_detach(tfile, clean);
+       if (dev)
+               netdev_state_change(dev);
        rtnl_unlock();
 }
 
@@ -2562,13 +2569,15 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
                        /* One or more queue has already been attached, no need
                         * to initialize the device again.
                         */
+                       netdev_state_change(dev);
                        return 0;
                }
 
                tun->flags = (tun->flags & ~TUN_FEATURES) |
                              (ifr->ifr_flags & TUN_FEATURES);
-       }
-       else {
+
+               netdev_state_change(dev);
+       } else {
                char *name;
                unsigned long flags = 0;
                int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
@@ -2808,6 +2817,9 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
        } else
                ret = -EINVAL;
 
+       if (ret >= 0)
+               netdev_state_change(tun->dev);
+
 unlock:
        rtnl_unlock();
        return ret;
@@ -2848,6 +2860,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
        unsigned int ifindex;
        int le;
        int ret;
+       bool do_notify = false;
 
        if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
            (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
@@ -2944,10 +2957,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                if (arg && !(tun->flags & IFF_PERSIST)) {
                        tun->flags |= IFF_PERSIST;
                        __module_get(THIS_MODULE);
+                       do_notify = true;
                }
                if (!arg && (tun->flags & IFF_PERSIST)) {
                        tun->flags &= ~IFF_PERSIST;
                        module_put(THIS_MODULE);
+                       do_notify = true;
                }
 
                tun_debug(KERN_INFO, tun, "persist %s\n",
@@ -2962,6 +2977,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                        break;
                }
                tun->owner = owner;
+               do_notify = true;
                tun_debug(KERN_INFO, tun, "owner set to %u\n",
                          from_kuid(&init_user_ns, tun->owner));
                break;
@@ -2974,6 +2990,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                        break;
                }
                tun->group = group;
+               do_notify = true;
                tun_debug(KERN_INFO, tun, "group set to %u\n",
                          from_kgid(&init_user_ns, tun->group));
                break;
@@ -3133,6 +3150,9 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                break;
        }
 
+       if (do_notify)
+               netdev_state_change(tun->dev);
+
 unlock:
        rtnl_unlock();
        if (tun)