batman-adv: Make sysfs support optional

The sysfs files will be marked as deprecated in the near future. They are
already replaced by the batadv generic netlink family. Add an Kconfig
option to disable the sysfs support for users who want to test their tools
or want to safe some space. This setting should currently still be enabled
by default to keep backward compatible with legacy tools.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

1 files changed, 73 insertions, 0 deletions

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 33b9b38b82da..dabcaff87e34 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -10,6 +10,7 @@
 #include <linux/build_bug.h>
 #include <linux/byteorder/generic.h>
 #include <linux/crc32c.h>
+#include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/genetlink.h>
 #include <linux/gfp.h>
@@ -19,6 +20,7 @@
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/kernel.h>
+#include <linux/kobject.h>
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/module.h>
@@ -28,6 +30,7 @@
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/stddef.h>
 #include <linux/string.h>
@@ -72,6 +75,22 @@ struct workqueue_struct *batadv_event_workqueue;
 
 static void batadv_recv_handler_init(void);
 
+#define BATADV_UEV_TYPE_VAR	"BATTYPE="
+#define BATADV_UEV_ACTION_VAR	"BATACTION="
+#define BATADV_UEV_DATA_VAR	"BATDATA="
+
+static char *batadv_uev_action_str[] = {
+	"add",
+	"del",
+	"change",
+	"loopdetect",
+};
+
+static char *batadv_uev_type_str[] = {
+	"gw",
+	"bla",
+};
+
 static int __init batadv_init(void)
 {
 	int ret;
@@ -666,6 +685,60 @@ bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
 	return ap_isolation_enabled;
 }
 
+/**
+ * batadv_throw_uevent() - Send an uevent with batman-adv specific env data
+ * @bat_priv: the bat priv with all the soft interface information
+ * @type: subsystem type of event. Stored in uevent's BATTYPE
+ * @action: action type of event. Stored in uevent's BATACTION
+ * @data: string with additional information to the event (ignored for
+ *  BATADV_UEV_DEL). Stored in uevent's BATDATA
+ *
+ * Return: 0 on success or negative error number in case of failure
+ */
+int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
+			enum batadv_uev_action action, const char *data)
+{
+	int ret = -ENOMEM;
+	struct kobject *bat_kobj;
+	char *uevent_env[4] = { NULL, NULL, NULL, NULL };
+
+	bat_kobj = &bat_priv->soft_iface->dev.kobj;
+
+	uevent_env[0] = kasprintf(GFP_ATOMIC,
+				  "%s%s", BATADV_UEV_TYPE_VAR,
+				  batadv_uev_type_str[type]);
+	if (!uevent_env[0])
+		goto out;
+
+	uevent_env[1] = kasprintf(GFP_ATOMIC,
+				  "%s%s", BATADV_UEV_ACTION_VAR,
+				  batadv_uev_action_str[action]);
+	if (!uevent_env[1])
+		goto out;
+
+	/* If the event is DEL, ignore the data field */
+	if (action != BATADV_UEV_DEL) {
+		uevent_env[2] = kasprintf(GFP_ATOMIC,
+					  "%s%s", BATADV_UEV_DATA_VAR, data);
+		if (!uevent_env[2])
+			goto out;
+	}
+
+	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
+out:
+	kfree(uevent_env[0]);
+	kfree(uevent_env[1]);
+	kfree(uevent_env[2]);
+
+	if (ret)
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
+			   batadv_uev_type_str[type],
+			   batadv_uev_action_str[action],
+			   (action == BATADV_UEV_DEL ? "NULL" : data), ret);
+	return ret;
+}
+
 module_init(batadv_init);
 module_exit(batadv_exit);