[B.A.T.M.A.N.] [PATCH v3 1/2] batman-adv: Use default throughput value on cfg80211 error

[B.A.T.M.A.N.] [PATCH v3 1/2] batman-adv: Use default throughput value on cfg80211 error

[Sven Eckelmann]

A wifi interface should never be handled like an ethernet devices. The
parser of the cfg80211 output must therefore skip the ethtool code when
cfg80211_get_station returned an error.

Fixes: 01b1fe819ee0 ("batman-adv: refactor wifi interface detection")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
v2:
 - no changes

 net/batman-adv/bat_v_elp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index b90c9903..96e73337 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -109,8 +109,10 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 			 */
 			return 0;
 		}
-		if (!ret)
-			return sinfo.expected_throughput / 100;
+		if (ret)
+			goto default_throughput;
+
+		return sinfo.expected_throughput / 100;
 	}
 
 	/* if not a wifi interface, check if this device provides data via
-- 
2.11.0

[B.A.T.M.A.N.] [PATCH v3 2/2] batman-adv: Accept only filled wifi station info

[Sven Eckelmann]

The wifi driver can decide to not provide parts of the station info. For
example, the expected throughput of the station can be omitted when the
used rate control doesn't provide this kind of information.

The B.A.T.M.A.N. V implementation must therefore check the filled bitfield
before it tries to access the expected_throughput of the returned
station_info.

Reported-by: Alvaro Antelo <alvaro.antelo@gmail.com>
Fixes: 5c3245172c01 ("batman-adv: ELP - compute the metric based on the estimated throughput")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
v3:
 - work around compat problems with v3.15 and below
v2:
 - switched to BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT) for Linux 4.0+

 compat-include/linux/nl80211.h      | 14 ++++++++++++++
 compat-include/uapi/linux/nl80211.h | 16 ++++++++++++++++
 net/batman-adv/bat_v_elp.c          |  4 ++++
 3 files changed, 34 insertions(+)
 create mode 100644 compat-include/linux/nl80211.h
 create mode 100644 compat-include/uapi/linux/nl80211.h

diff --git a/compat-include/linux/nl80211.h b/compat-include/linux/nl80211.h
new file mode 100644
index 00000000..e6654df8
--- /dev/null
+++ b/compat-include/linux/nl80211.h
@@ -0,0 +1,14 @@
+#ifndef _NET_BATMAN_ADV_COMPAT_LINUX_NL80211_H_
+#define _NET_BATMAN_ADV_COMPAT_LINUX_NL80211_H_
+
+#include <linux/version.h>
+#include_next <linux/nl80211.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 16, 0)
+
+/* Linux 3.15 misses the uapi include.... */
+#include <uapi/linux/nl80211.h>
+
+#endif /* < KERNEL_VERSION(3, 16, 0) */
+
+#endif	/* _NET_BATMAN_ADV_COMPAT_LINUX_NL80211_H_ */
diff --git a/compat-include/uapi/linux/nl80211.h b/compat-include/uapi/linux/nl80211.h
new file mode 100644
index 00000000..06f5625a
--- /dev/null
+++ b/compat-include/uapi/linux/nl80211.h
@@ -0,0 +1,16 @@
+#ifndef _NET_BATMAN_ADV_COMPAT_UAPI_LINUX_NL80211_H_
+#define _NET_BATMAN_ADV_COMPAT_UAPI_LINUX_NL80211_H_
+
+#include <linux/version.h>
+#include_next <uapi/linux/nl80211.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
+
+/* for batadv_v_elp_get_throughput which would have used
+ * STATION_INFO_EXPECTED_THROUGHPUT in Linux 4.0.0
+ */
+#define NL80211_STA_INFO_EXPECTED_THROUGHPUT    28
+
+#endif /* < KERNEL_VERSION(4, 0, 0) */
+
+#endif	/* _NET_BATMAN_ADV_COMPAT_UAPI_LINUX_NL80211_H_ */
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index 96e73337..b58007b7 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -19,6 +19,7 @@
 #include "main.h"
 
 #include <linux/atomic.h>
+#include <linux/bitops.h>
 #include <linux/byteorder/generic.h>
 #include <linux/errno.h>
 #include <linux/etherdevice.h>
@@ -29,6 +30,7 @@
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/netdevice.h>
+#include <linux/nl80211.h>
 #include <linux/random.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
@@ -111,6 +113,8 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 		}
 		if (ret)
 			goto default_throughput;
+		if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
+			goto default_throughput;
 
 		return sinfo.expected_throughput / 100;
 	}
-- 
2.11.0

Re: [B.A.T.M.A.N.] [PATCH v3 2/2] batman-adv: Accept only filled wifi station info

[Marek Lindner]

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On Friday, June 9, 2017 5:06:51 PM HKT Sven Eckelmann wrote:
> The wifi driver can decide to not provide parts of the station info. For
> example, the expected throughput of the station can be omitted when the
> used rate control doesn't provide this kind of information.
> 
> The B.A.T.M.A.N. V implementation must therefore check the filled bitfield
> before it tries to access the expected_throughput of the returned
> station_info.

We tested the patchset on the battlemesh testbed and can confirm that it 
reduces the packet loss rate over lossy links to 1-2% which previously had 
been at 20-30%.

Reviewed-by: Marek Lindner <mareklindner@neomailbox.ch>


Cheers,
Marek


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