Fix minor bug.

Add draft of ac kernel module.

src/ac/kmod/Makefile

@@ -0,0 +1,13 @@
+KVERSION = $(shell uname -r)
+
+obj-m += smartcapwap.o
+
+smartcapwap-y := \
+	main.o \
+	netlinkapp.o
+
+all:
+	make -C /lib/modules/$(KVERSION)/build M="$(PWD)" modules
+
+clean:
+	make -C /lib/modules/$(KVERSION)/build M="$(PWD)" clean

src/ac/kmod/main.c

@@ -0,0 +1,24 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include "netlinkapp.h"
+
+/* */
+static int __init smartcapwap_ac_init(void) {
+	int result = 0;
+
+	/* */
+	result = nlsmartcapwap_ac_init();
+
+	return result;
+}
+module_init(smartcapwap_ac_init);
+
+/* */
+static void __exit smartcapwap_ac_exit(void) {
+	nlsmartcapwap_ac_exit();
+}
+module_exit(smartcapwap_ac_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Massimo Vellucci <vemax78@gmail.com>");
+MODULE_DESCRIPTION("SmartCAPWAP AC Data Channel Module");

src/ac/kmod/netlinkapp.c

@@ -0,0 +1,158 @@
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/rtnetlink.h>
+#include <linux/netlink.h>
+#include <net/genetlink.h>
+#include <linux/rcupdate.h>
+#include <linux/err.h>
+#include <net/mac80211.h>
+#include <linux/ieee80211.h>
+#include "nlsmartcapwap.h"
+#include "netlinkapp.h"
+
+/* */
+struct nlsmartcapwap_ac_device {
+	struct list_head list;
+
+	u32 usermodeid;
+};
+
+/* */
+static u32 nlsmartcapwap_ac_usermodeid = 0;
+static LIST_HEAD(nlsmartcapwap_ac_dev_list);
+
+/* Netlink Family */
+static struct genl_family nlsmartcapwap_ac_family = {
+	.id = GENL_ID_GENERATE,
+	.name = SMARTCAPWAP_AC_GENL_NAME,
+	.hdrsize = 0,
+	.version = 1,
+	.maxattr = NLSMARTCAPWAP_AC_ATTR_MAX,
+	.netnsok = true,
+};
+
+/* */
+static void nlsmartcapwap_ac_free_device(struct nlsmartcapwap_ac_device* nldev) {
+	/* Free memory */
+	kfree(nldev);
+}
+
+/* */
+static void nlsmartcapwap_ac_close(void) {
+	struct nlsmartcapwap_ac_device* nldev;
+	struct nlsmartcapwap_ac_device* tmp;
+
+	list_for_each_entry_safe(nldev, tmp, &nlsmartcapwap_ac_dev_list, list) {
+		list_del(&nldev->list);
+
+		/* Free device */
+		nlsmartcapwap_ac_free_device(nldev);
+	}
+}
+
+
+/* */
+static int nlsmartcapwap_ac_link(struct sk_buff* skb, struct genl_info* info) {
+	int ret = 0;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,7,0)
+	u32 portid = info->snd_pid;
+#else
+	u32 portid = info->snd_portid;
+#endif
+
+	rtnl_lock();
+
+	if (!nlsmartcapwap_ac_usermodeid) {
+		nlsmartcapwap_ac_usermodeid = portid;
+	} else if (nlsmartcapwap_ac_usermodeid == portid) {
+		ret = -EALREADY;
+	} else {
+		ret = -EBUSY;
+	}
+
+	rtnl_unlock();
+
+	return ret;
+}
+
+/* */
+static int nlsmartcapwap_ac_netlink_notify(struct notifier_block* nb, unsigned long state, void* _notify) {
+	struct netlink_notify* notify = (struct netlink_notify*)_notify;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,7,0)
+	u32 portid = notify->pid;
+#else
+	u32 portid = notify->portid;
+#endif
+
+	/* */
+	if (state == NETLINK_URELEASE) {
+		rtnl_lock();
+
+		if (nlsmartcapwap_ac_usermodeid == portid) {
+			nlsmartcapwap_ac_usermodeid = 0;
+
+			/* Close all devices */
+			nlsmartcapwap_ac_close();
+		}
+
+		rtnl_unlock();
+	}
+
+	return NOTIFY_DONE;
+}
+
+/* */
+static const struct nla_policy nlsmartcapwap_ac_policy[NLSMARTCAPWAP_AC_ATTR_MAX + 1] = {
+	[NLSMARTCAPWAP_AC_ATTR_FLAGS] = { .type = NLA_U32 },
+};
+
+/* Netlink Ops */
+static struct genl_ops nlsmartcapwap_ac_ops[] = {
+	{
+		.cmd = NLSMARTCAPWAP_AC_CMD_LINK,
+		.doit = nlsmartcapwap_ac_link,
+		.policy = nlsmartcapwap_ac_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+};
+
+/* Netlink notify */
+static struct notifier_block nlsmartcapwap_ac_netlink_notifier = {
+	.notifier_call = nlsmartcapwap_ac_netlink_notify,
+};
+
+/* */
+int nlsmartcapwap_ac_init(void) {
+	int ret;
+
+	/* Register netlink family */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,12,0)
+	ret = genl_register_family_with_ops(&nlsmartcapwap_ac_family, nlsmartcapwap_ac_ops, sizeof(nlsmartcapwap_ac_ops) / sizeof(nlsmartcapwap_ac_ops[0]));
+#else
+	ret = genl_register_family_with_ops(&nlsmartcapwap_ac_family, nlsmartcapwap_ac_ops);
+#endif
+	if (ret) {
+		return ret;
+	}
+
+	/* Register netlink notifier */
+	ret = netlink_register_notifier(&nlsmartcapwap_ac_netlink_notifier);
+	if (ret) {
+		genl_unregister_family(&nlsmartcapwap_ac_family);
+		return ret;
+	}
+
+	return ret;
+}
+
+/* */
+void nlsmartcapwap_ac_exit(void) {
+	/* */
+	rtnl_lock();
+	nlsmartcapwap_ac_close();
+	rtnl_unlock();
+
+	/* */
+	netlink_unregister_notifier(&nlsmartcapwap_ac_netlink_notifier);
+	genl_unregister_family(&nlsmartcapwap_ac_family);
+}

src/ac/kmod/netlinkapp.h

@@ -0,0 +1,8 @@
+#ifndef __KMOD_AC_NETLINKAPP_HEADER__
+#define __KMOD_AC_NETLINKAPP_HEADER__
+
+/* */
+int nlsmartcapwap_ac_init(void);
+void nlsmartcapwap_ac_exit(void);
+
+#endif /* __KMOD_AC_NETLINKAPP_HEADER__ */

src/ac/kmod/nlsmartcapwap.h

@@ -0,0 +1,29 @@
+#ifndef __AC_NLSMARTCAPWAP_HEADER__
+#define __AC_NLSMARTCAPWAP_HEADER__
+
+/* */
+#define SMARTCAPWAP_AC_GENL_NAME			"smartcapwap_ac"
+
+/* */
+enum nlsmartcapwap_ac_attrs {
+	NLSMARTCAPWAP_AC_ATTR_UNSPEC,
+
+	NLSMARTCAPWAP_AC_ATTR_FLAGS,
+
+	/* Last attribute */
+	__NLSMARTCAPWAP_AC_ATTR_AFTER_LAST,
+	NLSMARTCAPWAP_AC_ATTR_MAX = __NLSMARTCAPWAP_AC_ATTR_AFTER_LAST - 1
+};
+
+/* */
+enum nlsmartcapwap_ac_commands {
+	NLSMARTCAPWAP_AC_CMD_UNSPEC,
+
+	NLSMARTCAPWAP_AC_CMD_LINK,
+
+	/* Last command */
+	__NLSMARTCAPWAP_AC_CMD_AFTER_LAST,
+	NLSMARTCAPWAP_AC_CMD_MAX = __NLSMARTCAPWAP_AC_CMD_AFTER_LAST - 1
+};
+
+#endif /* __AC_NLSMARTCAPWAP_HEADER__ */