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authorNikolay Aleksandrov <nikolay@cumulusnetworks.com>2015-11-28 13:45:28 +0100
committerDavid S. Miller <davem@davemloft.net>2015-12-01 15:31:57 -0500
commit02fff96a79775b7adc34eb599fc6b0476ccda520 (patch)
treeb8b5ccf5a9c21f47ef78f563ff8c6c734567be64 /lib/netdev-notifier-error-inject.c
parent27a70af3f4cf633a1b86c0ac7b426e2fe16ad2e5 (diff)
net: add support for netdev notifier error injection
This module allows to insert errors in some of netdevice's notifier events. All network drivers use these notifiers to signal various events and to check if they are allowed, e.g. PRECHANGEMTU and CHANGEMTU afterwards. Until recently I had to run failure tests by injecting a custom module, but now this infrastructure makes it trivial to test these failure paths. Some of the recent bugs I fixed were found using this module. Here's an example: $ cd /sys/kernel/debug/notifier-error-inject/netdev $ echo -22 > actions/NETDEV_CHANGEMTU/error $ ip link set eth0 mtu 1024 RTNETLINK answers: Invalid argument CC: Akinobu Mita <akinobu.mita@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev <netdev@vger.kernel.org> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/netdev-notifier-error-inject.c')
-rw-r--r--lib/netdev-notifier-error-inject.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/lib/netdev-notifier-error-inject.c b/lib/netdev-notifier-error-inject.c
new file mode 100644
index 000000000000..b2b856675d61
--- /dev/null
+++ b/lib/netdev-notifier-error-inject.c
@@ -0,0 +1,54 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+
+#include "notifier-error-inject.h"
+
+static int priority;
+module_param(priority, int, 0);
+MODULE_PARM_DESC(priority, "specify netdevice notifier priority");
+
+static struct notifier_err_inject netdev_notifier_err_inject = {
+ .actions = {
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_REGISTER) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGEMTU) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_CHANGENAME) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_UP) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRE_TYPE_CHANGE) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_POST_INIT) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEMTU) },
+ { NOTIFIER_ERR_INJECT_ACTION(NETDEV_PRECHANGEUPPER) },
+ {}
+ }
+};
+
+static struct dentry *dir;
+
+static int netdev_err_inject_init(void)
+{
+ int err;
+
+ dir = notifier_err_inject_init("netdev", notifier_err_inject_dir,
+ &netdev_notifier_err_inject, priority);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+
+ err = register_netdevice_notifier(&netdev_notifier_err_inject.nb);
+ if (err)
+ debugfs_remove_recursive(dir);
+
+ return err;
+}
+
+static void netdev_err_inject_exit(void)
+{
+ unregister_netdevice_notifier(&netdev_notifier_err_inject.nb);
+ debugfs_remove_recursive(dir);
+}
+
+module_init(netdev_err_inject_init);
+module_exit(netdev_err_inject_exit);
+
+MODULE_DESCRIPTION("Netdevice notifier error injection module");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nikolay Aleksandrov <razor@blackwall.org>");