| From: Sven Eckelmann <sven@narfation.org> |
| Date: Fri, 1 Jun 2018 19:24:24 +0200 |
| Subject: batman-adv: Fix debugfs path for renamed softif |
| |
| commit 6da7be7d24b2921f8215473ba7552796dff05fe1 upstream. |
| |
| batman-adv is creating special debugfs directories in the init |
| net_namespace for each created soft-interface (batadv net_device). But it |
| is possible to rename a net_device to a completely different name then the |
| original one. |
| |
| It can therefore happen that a user registers a new batadv net_device with |
| the name "bat0". batman-adv is then also adding a new directory under |
| $debugfs/batman-adv/ with the name "wlan0". |
| |
| The user then decides to rename this device to "bat1" and registers a |
| different batadv device with the name "bat0". batman-adv will then try to |
| create a directory with the name "bat0" under $debugfs/batman-adv/ again. |
| But there already exists one with this name under this path and thus this |
| fails. batman-adv will detect a problem and rollback the registering of |
| this device. |
| |
| batman-adv must therefore take care of renaming the debugfs directories for |
| soft-interfaces whenever it detects such a net_device rename. |
| |
| Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") |
| Signed-off-by: Sven Eckelmann <sven@narfation.org> |
| Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> |
| [bwh: Backported to 3.16: adjust context] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| net/batman-adv/debugfs.c | 20 +++++++++++++++++++ |
| net/batman-adv/debugfs.h | 5 +++++ |
| net/batman-adv/hard-interface.c | 34 +++++++++++++++++++++++++++------ |
| 3 files changed, 53 insertions(+), 6 deletions(-) |
| |
| --- a/net/batman-adv/debugfs.c |
| +++ b/net/batman-adv/debugfs.c |
| @@ -560,6 +560,26 @@ out: |
| return -ENOMEM; |
| } |
| |
| +/** |
| + * batadv_debugfs_rename_meshif() - Fix debugfs path for renamed softif |
| + * @dev: net_device which was renamed |
| + */ |
| +void batadv_debugfs_rename_meshif(struct net_device *dev) |
| +{ |
| + struct batadv_priv *bat_priv = netdev_priv(dev); |
| + const char *name = dev->name; |
| + struct dentry *dir; |
| + struct dentry *d; |
| + |
| + dir = bat_priv->debug_dir; |
| + if (!dir) |
| + return; |
| + |
| + d = debugfs_rename(dir->d_parent, dir, dir->d_parent, name); |
| + if (!d) |
| + pr_err("Can't rename debugfs dir to %s\n", name); |
| +} |
| + |
| void batadv_debugfs_del_meshif(struct net_device *dev) |
| { |
| struct batadv_priv *bat_priv = netdev_priv(dev); |
| --- a/net/batman-adv/debugfs.h |
| +++ b/net/batman-adv/debugfs.h |
| @@ -25,6 +25,7 @@ |
| void batadv_debugfs_init(void); |
| void batadv_debugfs_destroy(void); |
| int batadv_debugfs_add_meshif(struct net_device *dev); |
| +void batadv_debugfs_rename_meshif(struct net_device *dev); |
| void batadv_debugfs_del_meshif(struct net_device *dev); |
| int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface); |
| void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface); |
| @@ -45,6 +46,10 @@ static inline int batadv_debugfs_add_mes |
| return 0; |
| } |
| |
| +static inline void batadv_debugfs_rename_meshif(struct net_device *dev) |
| +{ |
| +} |
| + |
| static inline void batadv_debugfs_del_meshif(struct net_device *dev) |
| { |
| } |
| --- a/net/batman-adv/hard-interface.c |
| +++ b/net/batman-adv/hard-interface.c |
| @@ -640,6 +640,32 @@ void batadv_hardif_remove_interfaces(voi |
| rtnl_unlock(); |
| } |
| |
| +/** |
| + * batadv_hard_if_event_softif() - Handle events for soft interfaces |
| + * @event: NETDEV_* event to handle |
| + * @net_dev: net_device which generated an event |
| + * |
| + * Return: NOTIFY_* result |
| + */ |
| +static int batadv_hard_if_event_softif(unsigned long event, |
| + struct net_device *net_dev) |
| +{ |
| + struct batadv_priv *bat_priv; |
| + |
| + switch (event) { |
| + case NETDEV_REGISTER: |
| + batadv_sysfs_add_meshif(net_dev); |
| + bat_priv = netdev_priv(net_dev); |
| + batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS); |
| + break; |
| + case NETDEV_CHANGENAME: |
| + batadv_debugfs_rename_meshif(net_dev); |
| + break; |
| + } |
| + |
| + return NOTIFY_DONE; |
| +} |
| + |
| static int batadv_hard_if_event(struct notifier_block *this, |
| unsigned long event, void *ptr) |
| { |
| @@ -648,12 +674,8 @@ static int batadv_hard_if_event(struct n |
| struct batadv_hard_iface *primary_if = NULL; |
| struct batadv_priv *bat_priv; |
| |
| - if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) { |
| - batadv_sysfs_add_meshif(net_dev); |
| - bat_priv = netdev_priv(net_dev); |
| - batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS); |
| - return NOTIFY_DONE; |
| - } |
| + if (batadv_softif_is_valid(net_dev)) |
| + return batadv_hard_if_event_softif(event, net_dev); |
| |
| hard_iface = batadv_hardif_get_by_netdev(net_dev); |
| if (!hard_iface && event == NETDEV_REGISTER) |