[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

[Sven Eckelmann]

The net_xmit_eval has side effects because it is not making sure that e
isn't evaluated twice.

    #define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))

The code proposed by David Miller

    return net_xmit_eval(dev_queue_xmit(skb));

will therefore get transformed into

    return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))

dev_queue_xmit will therefore be tried again (with an already consumed skb)
whenever the return code is not NET_XMIT_CN.

Fixes: 17efab9867c5 ("batman-adv: Simplify handling of NET_XMIT_CN")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/send.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index d9b28890..1489ec27 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -77,6 +77,7 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 {
 	struct batadv_priv *bat_priv;
 	struct ethhdr *ethhdr;
+	int ret;
 
 	bat_priv = netdev_priv(hard_iface->soft_iface);
 
@@ -115,7 +116,8 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 	 * (which is > 0). This will not be treated as an error.
 	 */
-	return net_xmit_eval(dev_queue_xmit(skb));
+	ret = dev_queue_xmit(skb);
+	return net_xmit_eval(ret);
 send_skb_err:
 	kfree_skb(skb);
 	return NET_XMIT_DROP;
-- 
2.11.0

Re: [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

[Sven Eckelmann]

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On Samstag, 28. Januar 2017 10:25:25 CET Sven Eckelmann wrote:
> The net_xmit_eval has side effects because it is not making sure that e
> isn't evaluated twice.
> 
>     #define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))
> 
> The code proposed by David Miller
> 
>     return net_xmit_eval(dev_queue_xmit(skb));
> 
> will therefore get transformed into
> 
>     return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))
> 
> dev_queue_xmit will therefore be tried again (with an already consumed skb)
> whenever the return code is not NET_XMIT_CN.
> 
> Fixes: 17efab9867c5 ("batman-adv: Simplify handling of NET_XMIT_CN")
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
>  net/batman-adv/send.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

I was so embarrassed about not catching these two that I've already applied
them an prepared the changes for net-next.

Kind regards,
	Sven

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[B.A.T.M.A.N.] [PATCH 0/2] pull request for net-next: batman-adv 2017-01-28

[Simon Wunderlich]

Hi David,

here is another pull request for batman-adv in net-next. One of them fixes
a regression introduced by a patch in the previous pull request two days ago.

Please pull or let me know of any problem!

Thank you,
      Simon

The following changes since commit c33705188c493b7de3b8dc2956d67de91b444727:

  batman-adv: Treat NET_XMIT_CN as transmit successfully (2017-01-26 08:41:18 +0100)

are available in the git repository at:

  git://git.open-mesh.org/linux-merge.git tags/batadv-next-for-davem-20170128

for you to fetch changes up to 3e7514afc7d728dd47c5fe9d7a1f5216fe659cda:

  batman-adv: Fix includes for IS_ERR/ERR_PTR (2017-01-28 10:40:35 +0100)

----------------------------------------------------------------
Here are two fixes for batman-adv for net-next:

 - fix double call of dev_queue_xmit(), caused by the recent introduction
   of net_xmit_eval(), by Sven Eckelmann

 - Fix includes for IS_ERR/ERR_PTR, by Sven Eckelmann

----------------------------------------------------------------
Sven Eckelmann (2):
      batman-adv: Fix double call of dev_queue_xmit
      batman-adv: Fix includes for IS_ERR/ERR_PTR

 net/batman-adv/debugfs.c  | 2 +-
 net/batman-adv/send.c     | 4 +++-
 net/batman-adv/tp_meter.c | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

The net_xmit_eval has side effects because it is not making sure that e
isn't evaluated twice.

    #define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))

The code requested by David Miller [1]

    return net_xmit_eval(dev_queue_xmit(skb));

will get transformed into

    return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))

dev_queue_xmit will therefore be tried again (with an already consumed skb)
whenever the return code is not NET_XMIT_CN.

[1] https://lkml.kernel.org/r/20170125.225624.965229145391320056.davem@davemloft.net

Fixes: c33705188c49 ("batman-adv: Treat NET_XMIT_CN as transmit successfully")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/send.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index d9b2889064a6..1489ec27daff 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -77,6 +77,7 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 {
 	struct batadv_priv *bat_priv;
 	struct ethhdr *ethhdr;
+	int ret;
 
 	bat_priv = netdev_priv(hard_iface->soft_iface);
 
@@ -115,7 +116,8 @@ int batadv_send_skb_packet(struct sk_buff *skb,
 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 	 * (which is > 0). This will not be treated as an error.
 	 */
-	return net_xmit_eval(dev_queue_xmit(skb));
+	ret = dev_queue_xmit(skb);
+	return net_xmit_eval(ret);
 send_skb_err:
 	kfree_skb(skb);
 	return NET_XMIT_DROP;
-- 
2.11.0

[B.A.T.M.A.N.] [PATCH 2/2] batman-adv: Fix includes for IS_ERR/ERR_PTR

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

IS_ERR/ERR_PTR are not defined in linux/device.h but in linux/err.h. The
files using these macros therefore have to include the correct one.

Reported-by: Linus Luessing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/debugfs.c  | 2 +-
 net/batman-adv/tp_meter.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 5406148b9497..e32ad47c6efd 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -19,7 +19,7 @@
 #include "main.h"
 
 #include <linux/debugfs.h>
-#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/fs.h>
diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index 07f64b60b528..c94ebdecdc3d 100644
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -23,7 +23,7 @@
 #include <linux/byteorder/generic.h>
 #include <linux/cache.h>
 #include <linux/compiler.h>
-#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/etherdevice.h>
 #include <linux/fs.h>
 #include <linux/if_ether.h>
-- 
2.11.0

Re: [B.A.T.M.A.N.] [PATCH 0/2] pull request for net-next: batman-adv 2017-01-28

[David Miller]

From: Simon Wunderlich <sw@simonwunderlich.de>
Date: Sat, 28 Jan 2017 11:56:49 +0100

> here is another pull request for batman-adv in net-next. One of them fixes
> a regression introduced by a patch in the previous pull request two days ago.
> 
> Please pull or let me know of any problem!

Pulled, thanks Simon.

Re: [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix double call of dev_queue_xmit

[David Laight]

From: Simon Wunderlich
> Sent: 28 January 2017 10:57
> From: Sven Eckelmann <sven@narfation.org>
> 
> The net_xmit_eval has side effects because it is not making sure that e
> isn't evaluated twice.
> 
>     #define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))

It is probably worth fixing the #define.

	David