[PATCH 0/6] pull request for net: batman-adv 2018-07-17

[PATCH 0/6] pull request for net: batman-adv 2018-07-17

[Simon Wunderlich]

Hi David,

here are some batman-adv bugfixes for net.

Please pull or let me know of any problem!

Thank you,
      Simon

The following changes since commit ce397d215ccd07b8ae3f71db689aedb85d56ab40:

  Linux 4.18-rc1 (2018-06-17 08:04:49 +0900)

are available in the git repository at:

  git://git.open-mesh.org/linux-merge.git tags/batadv-net-for-davem-20180717

for you to fetch changes up to a44ebeff6bbd6ef50db41b4195fca87b21aefd20:

  batman-adv: Fix multicast TT issues with bogus ROAM flags (2018-06-23 10:29:33 +0200)

----------------------------------------------------------------
Here are some batman-adv fixes:

 - Fix gateway refcounting in BATMAN IV and V, by Sven Eckelmann (2 patches)

 - Fix debugfs paths when renaming interfaces, by Sven Eckelmann (2 patches)

 - Fix TT flag issues, by Linus Luessing (2 patches)

----------------------------------------------------------------
Linus Lüssing (2):
      batman-adv: Avoid storing non-TT-sync flags on singular entries too
      batman-adv: Fix multicast TT issues with bogus ROAM flags

Sven Eckelmann (4):
      batman-adv: Fix bat_ogm_iv best gw refcnt after netlink dump
      batman-adv: Fix bat_v best gw refcnt after netlink dump
      batman-adv: Fix debugfs path for renamed hardif
      batman-adv: Fix debugfs path for renamed softif

 net/batman-adv/bat_iv_ogm.c        |  4 +++-
 net/batman-adv/bat_v.c             |  4 +++-
 net/batman-adv/debugfs.c           | 40 ++++++++++++++++++++++++++++++++++++++
 net/batman-adv/debugfs.h           | 11 +++++++++++
 net/batman-adv/hard-interface.c    | 37 +++++++++++++++++++++++++++++------
 net/batman-adv/translation-table.c |  7 +++++--
 6 files changed, 93 insertions(+), 10 deletions(-)

[PATCH 1/6] batman-adv: Fix bat_ogm_iv best gw refcnt after netlink dump

[Simon Wunderlich]

From: Sven Eckelmann <sven-KaDOiPu9UxWEi8DpZVb4nw@public.gmane.org>

A reference for the best gateway is taken when the list of gateways in the
mesh is sent via netlink. This is necessary to check whether the currently
dumped entry is the currently selected gateway or not. This information is
then transferred as flag BATADV_ATTR_FLAG_BEST.

After the comparison of the current entry is done,
batadv_iv_gw_dump_entry() has to decrease the reference counter again.
Otherwise the reference will be held and thus prevents a proper shutdown of
the batman-adv interfaces (and some of the interfaces enslaved in it).

Fixes: efb766af06e3 ("batman-adv: add B.A.T.M.A.N. IV bat_gw_dump implementations")
Reported-by: Andreas Ziegler <dev-ARtvInVfO7m7XaAKMTL6PIQuADTiUCJX@public.gmane.org>
Tested-by: Andreas Ziegler <dev-ARtvInVfO7m7XaAKMTL6PIQuADTiUCJX@public.gmane.org>
Signed-off-by: Sven Eckelmann <sven-KaDOiPu9UxWEi8DpZVb4nw@public.gmane.org>
Acked-by: Marek Lindner <mareklindner-rVWd3aGhH2z5bpWLKbzFeg@public.gmane.org>
Signed-off-by: Simon Wunderlich <sw-2YrNx6rUIHYiY0qSoAWiAoQuADTiUCJX@public.gmane.org>
---
 net/batman-adv/bat_iv_ogm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index be09a9883825..73bf6a93a3cf 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -2732,7 +2732,7 @@ static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 {
 	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 	struct batadv_neigh_node *router;
-	struct batadv_gw_node *curr_gw;
+	struct batadv_gw_node *curr_gw = NULL;
 	int ret = 0;
 	void *hdr;
 
@@ -2780,6 +2780,8 @@ static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 	ret = 0;
 
 out:
+	if (curr_gw)
+		batadv_gw_node_put(curr_gw);
 	if (router_ifinfo)
 		batadv_neigh_ifinfo_put(router_ifinfo);
 	if (router)
-- 
2.11.0

[PATCH 2/6] batman-adv: Fix bat_v best gw refcnt after netlink dump

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

A reference for the best gateway is taken when the list of gateways in the
mesh is sent via netlink. This is necessary to check whether the currently
dumped entry is the currently selected gateway or not. This information is
then transferred as flag BATADV_ATTR_FLAG_BEST.

After the comparison of the current entry is done,
batadv_v_gw_dump_entry() has to decrease the reference counter again.
Otherwise the reference will be held and thus prevents a proper shutdown of
the batman-adv interfaces (and some of the interfaces enslaved in it).

Fixes: b71bb6f924fe ("batman-adv: add B.A.T.M.A.N. V bat_gw_dump implementations")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/bat_v.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index ec93337ee259..6baec4e68898 100644
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -927,7 +927,7 @@ static int batadv_v_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 {
 	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 	struct batadv_neigh_node *router;
-	struct batadv_gw_node *curr_gw;
+	struct batadv_gw_node *curr_gw = NULL;
 	int ret = 0;
 	void *hdr;
 
@@ -995,6 +995,8 @@ static int batadv_v_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
 	ret = 0;
 
 out:
+	if (curr_gw)
+		batadv_gw_node_put(curr_gw);
 	if (router_ifinfo)
 		batadv_neigh_ifinfo_put(router_ifinfo);
 	if (router)
-- 
2.11.0

[PATCH 3/6] batman-adv: Fix debugfs path for renamed hardif

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

batman-adv is creating special debugfs directories in the init
net_namespace for each valid hard-interface (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 net_device which gets
the name "wlan0" assigned by default. batman-adv is also adding a new
directory under $debugfs/batman-adv/ with the name "wlan0".

The user then decides to rename this device to "wl_pri" and registers a
different device. The kernel may now decide to use the name "wlan0" again
for this new device. batman-adv will detect it as a valid net_device and
tries to create a directory with the name "wlan0" under
$debugfs/batman-adv/. 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 hard-interfaces whenever it detects such a net_device rename.

Fixes: 5bc7c1eb44f2 ("batman-adv: add debugfs structure for information per interface")
Reported-by: John Soros <sorosj@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/debugfs.c        | 20 ++++++++++++++++++++
 net/batman-adv/debugfs.h        |  6 ++++++
 net/batman-adv/hard-interface.c |  3 +++
 3 files changed, 29 insertions(+)

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 4229b01ac7b5..7e5de7b9f6d5 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -19,6 +19,7 @@
 #include "debugfs.h"
 #include "main.h"
 
+#include <linux/dcache.h>
 #include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -344,6 +345,25 @@ int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface)
 }
 
 /**
+ * batadv_debugfs_rename_hardif() - Fix debugfs path for renamed hardif
+ * @hard_iface: hard interface which was renamed
+ */
+void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface)
+{
+	const char *name = hard_iface->net_dev->name;
+	struct dentry *dir;
+	struct dentry *d;
+
+	dir = hard_iface->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);
+}
+
+/**
  * batadv_debugfs_del_hardif() - delete the base directory for a hard interface
  *  in debugfs.
  * @hard_iface: hard interface which is deleted.
diff --git a/net/batman-adv/debugfs.h b/net/batman-adv/debugfs.h
index 37b069698b04..8538a7a75e93 100644
--- a/net/batman-adv/debugfs.h
+++ b/net/batman-adv/debugfs.h
@@ -32,6 +32,7 @@ void batadv_debugfs_destroy(void);
 int batadv_debugfs_add_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);
 void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface);
 
 #else
@@ -60,6 +61,11 @@ int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface)
 }
 
 static inline
+void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface)
+{
+}
+
+static inline
 void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface)
 {
 }
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index c405d15befd6..dc2763b11107 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -1051,6 +1051,9 @@ static int batadv_hard_if_event(struct notifier_block *this,
 		if (batadv_is_wifi_hardif(hard_iface))
 			hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 		break;
+	case NETDEV_CHANGENAME:
+		batadv_debugfs_rename_hardif(hard_iface);
+		break;
 	default:
 		break;
 	}
-- 
2.11.0

[PATCH 4/6] batman-adv: Fix debugfs path for renamed softif

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

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>
---
 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(-)

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 7e5de7b9f6d5..87479c60670e 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -434,6 +434,26 @@ int batadv_debugfs_add_meshif(struct net_device *dev)
 }
 
 /**
+ * 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);
+}
+
+/**
  * batadv_debugfs_del_meshif() - Remove interface dependent debugfs entries
  * @dev: netdev struct of the soft interface
  */
diff --git a/net/batman-adv/debugfs.h b/net/batman-adv/debugfs.h
index 8538a7a75e93..08a592ffbee5 100644
--- a/net/batman-adv/debugfs.h
+++ b/net/batman-adv/debugfs.h
@@ -30,6 +30,7 @@ struct net_device;
 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);
@@ -50,6 +51,10 @@ static inline int batadv_debugfs_add_meshif(struct net_device *dev)
 	return 0;
 }
 
+static inline void batadv_debugfs_rename_meshif(struct net_device *dev)
+{
+}
+
 static inline void batadv_debugfs_del_meshif(struct net_device *dev)
 {
 }
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index dc2763b11107..2f0d42f2f913 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -989,6 +989,32 @@ void batadv_hardif_remove_interfaces(void)
 	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)
 {
@@ -997,12 +1023,8 @@ static int batadv_hard_if_event(struct notifier_block *this,
 	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 ||
-- 
2.11.0

[PATCH 5/6] batman-adv: Avoid storing non-TT-sync flags on singular entries too

[Simon Wunderlich]

From: Linus Lüssing <linus.luessing@c0d3.blue>

Since commit 54e22f265e87 ("batman-adv: fix TT sync flag inconsistencies")
TT sync flags and TT non-sync'd flags are supposed to be stored
separately.

The previous patch missed to apply this separation on a TT entry with
only a single TT orig entry.

This is a minor fix because with only a single TT orig entry the DDoS
issue the former patch solves does not apply.

Fixes: 54e22f265e87 ("batman-adv: fix TT sync flag inconsistencies")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/translation-table.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 3986551397ca..61ce300091f3 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1705,7 +1705,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		ether_addr_copy(common->addr, tt_addr);
 		common->vid = vid;
 
-		common->flags = flags;
+		common->flags = flags & (~BATADV_TT_SYNC_MASK);
+
 		tt_global_entry->roam_at = 0;
 		/* node must store current time in case of roaming. This is
 		 * needed to purge this entry out on timeout (if nobody claims
-- 
2.11.0

[PATCH 6/6] batman-adv: Fix multicast TT issues with bogus ROAM flags

[Simon Wunderlich]

From: Linus Lüssing <linus.luessing@c0d3.blue>

When a (broken) node wrongly sends multicast TT entries with a ROAM
flag then this causes any receiving node to drop all entries for the
same multicast MAC address announced by other nodes, leading to
packet loss.

Fix this DoS vector by only storing TT sync flags. For multicast TT
non-sync'ing flag bits like ROAM are unused so far anyway.

Fixes: 1d8ab8d3c176 ("batman-adv: Modified forwarding behaviour for multicast packets")
Reported-by: Leonardo Mörlein <me@irrelefant.net>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/translation-table.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 61ce300091f3..12a2b7d21376 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1705,7 +1705,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		ether_addr_copy(common->addr, tt_addr);
 		common->vid = vid;
 
-		common->flags = flags & (~BATADV_TT_SYNC_MASK);
+		if (!is_multicast_ether_addr(common->addr))
+			common->flags = flags & (~BATADV_TT_SYNC_MASK);
 
 		tt_global_entry->roam_at = 0;
 		/* node must store current time in case of roaming. This is
@@ -1769,7 +1770,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		 * TT_CLIENT_TEMP, therefore they have to be copied in the
 		 * client entry
 		 */
-		common->flags |= flags & (~BATADV_TT_SYNC_MASK);
+		if (!is_multicast_ether_addr(common->addr))
+			common->flags |= flags & (~BATADV_TT_SYNC_MASK);
 
 		/* If there is the BATADV_TT_CLIENT_ROAM flag set, there is only
 		 * one originator left in the list and we previously received a
-- 
2.11.0

Re: [PATCH 0/6] pull request for net: batman-adv 2018-07-17

[David Miller]

From: Simon Wunderlich <sw@simonwunderlich.de>
Date: Tue, 17 Jul 2018 17:19:40 +0200

> here are some batman-adv bugfixes for net.
> 
> Please pull or let me know of any problem!

Pulled, thanks Simon.