Subject: [PATCH 1/1] drivers/net: param for lapbether for specific ethernet device

From: Stephen Moorby <[email-masked]>
Date: Wed, 19 Jun 2013 09:21:27 +0100

From 35607dd0607bca5322860703143c31cb04377764 Mon Sep 17 00:00:00 2001
From: Stephen Moorby <[email-masked]>
Date: Wed, 19 Jun 2013 08:22:51 +0100
Subject: [PATCH 1/1] drivers/net: param for lapbether for specific ethernet
  device

The lapbether driver binds to the first ethernet device that comes up.
This causes problems in hardware with multiple ethernet interfaces,
potentially resulting in the LAPB traffic on the wrong interface.
Have added a module parameter 'eth_dev' to specify the ethernet
interface over which lapbether should operate.  The module behaves
as before if no device is specified.

Patch created on linux-next 18-Jun-2013.
Tested on 2.6.32-45-generic.

Signed-off-by: Stephen Moorby <[email-masked]>
---
  drivers/net/wan/lapbether.c | 15 +++++++++++++--
  1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index a33a46f..510fc4a 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -47,6 +47,7 @@

  #include <net/x25device.h>

+static char *eth_dev;
  static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

  /* If this number is made larger, check that the temporary string buffer
@@ -381,8 +382,14 @@ static int lapbeth_device_event(struct 
notifier_block *this,
      switch (event) {
      case NETDEV_UP:
          /* New ethernet device -> new LAPB interface     */
-        if (lapbeth_get_x25_dev(dev) == NULL)
-            lapbeth_new_device(dev);
+        if (lapbeth_get_x25_dev(dev) == NULL) {
+            if (NULL != eth_dev) {
+                if (0 == strcmp(dev->name, eth_dev))
+                    lapbeth_new_device(dev);
+            } else {
+                lapbeth_new_device(dev);
+            }
+        }
          break;
      case NETDEV_DOWN:
          /* ethernet device closed -> close LAPB interface */
@@ -446,6 +453,10 @@ static void __exit lapbeth_cleanup_driver(void)
  }
  module_exit(lapbeth_cleanup_driver);

+module_param(eth_dev, charp, S_IRUGO);
+MODULE_PARM_DESC(eth_dev, "Ethernet device to use");
+
+
  MODULE_AUTHOR("Jonathan Naylor <[email-masked]>");
  MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
  MODULE_LICENSE("GPL");
-- 
1.8.1.2