batman-adv/patches/0043-batman-adv-Fix-debugfs-path-for-renamed-softif.patch

   1 From: Sven Eckelmann <sven@narfation.org>
   2 Date: Fri, 1 Jun 2018 19:24:24 +0200
   3 Subject: batman-adv: Fix debugfs path for renamed softif
   4
   5 batman-adv is creating special debugfs directories in the init
   6 net_namespace for each created soft-interface (batadv net_device). But it
   7 is possible to rename a net_device to a completely different name then the
   8 original one.
   9
  10 It can therefore happen that a user registers a new batadv net_device with
  11 the name "bat0". batman-adv is then also adding a new directory under
  12 $debugfs/batman-adv/ with the name "wlan0".
  13
  14 The user then decides to rename this device to "bat1" and registers a
  15 different batadv device with the name "bat0". batman-adv will then try to
  16 create a directory with the name "bat0" under $debugfs/batman-adv/ again.
  17 But there already exists one with this name under this path and thus this
  18 fails. batman-adv will detect a problem and rollback the registering of
  19 this device.
  20
  21 batman-adv must therefore take care of renaming the debugfs directories for
  22 soft-interfaces whenever it detects such a net_device rename.
  23
  24 Fixes: 230202d4b530 ("batman-adv: Move device for icmp injection to debugfs")
  25 Signed-off-by: Sven Eckelmann <sven@narfation.org>
  26
  27 Origin: backport, https://git.open-mesh.org/batman-adv.git/commit/3f2237bb191cd17654a4d5a5badfd6e7379c4b37
  28
  29 diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
  30 index a229d2d9acfd1f3d6fea071aa0df3bf06a0e2ecf..fa396394edd02e74f49323216027f4ef9739dfa0 100644
  31 --- a/net/batman-adv/debugfs.c
  32 +++ b/net/batman-adv/debugfs.c
  33 @@ -421,6 +421,26 @@ out:
  34         return -ENOMEM;
  35  }
  36
  37 +/**
  38 + * batadv_debugfs_rename_meshif() - Fix debugfs path for renamed softif
  39 + * @dev: net_device which was renamed
  40 + */
  41 +void batadv_debugfs_rename_meshif(struct net_device *dev)
  42 +{
  43 +       struct batadv_priv *bat_priv = netdev_priv(dev);
  44 +       const char *name = dev->name;
  45 +       struct dentry *dir;
  46 +       struct dentry *d;
  47 +
  48 +       dir = bat_priv->debug_dir;
  49 +       if (!dir)
  50 +               return;
  51 +
  52 +       d = debugfs_rename(dir->d_parent, dir, dir->d_parent, name);
  53 +       if (!d)
  54 +               pr_err("Can't rename debugfs dir to %s\n", name);
  55 +}
  56 +
  57  void batadv_debugfs_del_meshif(struct net_device *dev)
  58  {
  59         struct batadv_priv *bat_priv = netdev_priv(dev);
  60 diff --git a/net/batman-adv/debugfs.h b/net/batman-adv/debugfs.h
  61 index 3d9b684b862d0aa9d2380fbcb15fd4ef68a4511c..59a0d6d70ecd4d0b49e15138306acc371da2d8b7 100644
  62 --- a/net/batman-adv/debugfs.h
  63 +++ b/net/batman-adv/debugfs.h
  64 @@ -29,6 +29,7 @@ struct net_device;
  65  void batadv_debugfs_init(void);
  66  void batadv_debugfs_destroy(void);
  67  int batadv_debugfs_add_meshif(struct net_device *dev);
  68 +void batadv_debugfs_rename_meshif(struct net_device *dev);
  69  void batadv_debugfs_del_meshif(struct net_device *dev);
  70  int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface);
  71  void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface);
  72 @@ -49,6 +50,10 @@ static inline int batadv_debugfs_add_meshif(struct net_device *dev)
  73         return 0;
  74  }
  75
  76 +static inline void batadv_debugfs_rename_meshif(struct net_device *dev)
  77 +{
  78 +}
  79 +
  80  static inline void batadv_debugfs_del_meshif(struct net_device *dev)
  81  {
  82  }
  83 diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
  84 index 507eaff8582a8c58adc6d23abc42bb6c31d2816f..23d3893264f989c9740e68d83f6db300dee20dc3 100644
  85 --- a/net/batman-adv/hard-interface.c
  86 +++ b/net/batman-adv/hard-interface.c
  87 @@ -958,6 +958,32 @@ void batadv_hardif_remove_interfaces(void)
  88         rtnl_unlock();
  89  }
  90
  91 +/**
  92 + * batadv_hard_if_event_softif() - Handle events for soft interfaces
  93 + * @event: NETDEV_* event to handle
  94 + * @net_dev: net_device which generated an event
  95 + *
  96 + * Return: NOTIFY_* result
  97 + */
  98 +static int batadv_hard_if_event_softif(unsigned long event,
  99 +                                      struct net_device *net_dev)
 100 +{
 101 +       struct batadv_priv *bat_priv;
 102 +
 103 +       switch (event) {
 104 +       case NETDEV_REGISTER:
 105 +               batadv_sysfs_add_meshif(net_dev);
 106 +               bat_priv = netdev_priv(net_dev);
 107 +               batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 108 +               break;
 109 +       case NETDEV_CHANGENAME:
 110 +               batadv_debugfs_rename_meshif(net_dev);
 111 +               break;
 112 +       }
 113 +
 114 +       return NOTIFY_DONE;
 115 +}
 116 +
 117  static int batadv_hard_if_event(struct notifier_block *this,
 118                                 unsigned long event, void *ptr)
 119  {
 120 @@ -966,12 +992,8 @@ static int batadv_hard_if_event(struct notifier_block *this,
 121         struct batadv_hard_iface *primary_if = NULL;
 122         struct batadv_priv *bat_priv;
 123
 124 -       if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
 125 -               batadv_sysfs_add_meshif(net_dev);
 126 -               bat_priv = netdev_priv(net_dev);
 127 -               batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
 128 -               return NOTIFY_DONE;
 129 -       }
 130 +       if (batadv_softif_is_valid(net_dev))
 131 +               return batadv_hard_if_event_softif(event, net_dev);
 132
 133         hard_iface = batadv_hardif_get_by_netdev(net_dev);
 134         if (!hard_iface && (event == NETDEV_REGISTER ||