wimax: Add netlink interface to get device state

wimax connection manager / daemon has to know what is current
state of the device. Previously it was only possible to get
notification whet state has changed.

Note:

 By mistake, the new generic netlink's number for
 WIMAX_GNL_OP_STATE_GET was declared inserting into the existing list
 of API calls, not appending; thus, it'd break existing API.

 Fixed by Inaky Perez-Gonzalez <inaky@linux.intel.com> by moving to
 the tail, where we add to the interface, not modify the interface.

 Thanks to Stephen Hemminger <shemminger@vyatta.com> for catching this.

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>

1 files changed, 86 insertions, 0 deletions

diff --git a/net/wimax/op-state-get.c b/net/wimax/op-state-get.c
new file mode 100644
index 000000000000..a76b8fcb056d
--- /dev/null
+++ b/net/wimax/op-state-get.c
@@ -0,0 +1,86 @@
+/*
+ * Linux WiMAX
+ * Implement and export a method for getting a WiMAX device current state
+ *
+ * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * Based on previous WiMAX core work by:
+ *  Copyright (C) 2008 Intel Corporation <linux-wimax@intel.com>
+ *  Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <net/wimax.h>
+#include <net/genetlink.h>
+#include <linux/wimax.h>
+#include <linux/security.h>
+#include "wimax-internal.h"
+
+#define D_SUBMODULE op_state_get
+#include "debug-levels.h"
+
+
+static const
+struct nla_policy wimax_gnl_state_get_policy[WIMAX_GNL_ATTR_MAX + 1] = {
+	[WIMAX_GNL_STGET_IFIDX] = {
+		.type = NLA_U32,
+	},
+};
+
+
+/*
+ * Exporting to user space over generic netlink
+ *
+ * Parse the state get command from user space, return a combination
+ * value that describe the current state.
+ *
+ * No attributes.
+ */
+static
+int wimax_gnl_doit_state_get(struct sk_buff *skb, struct genl_info *info)
+{
+	int result, ifindex;
+	struct wimax_dev *wimax_dev;
+	struct device *dev;
+
+	d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
+	result = -ENODEV;
+	if (info->attrs[WIMAX_GNL_STGET_IFIDX] == NULL) {
+		printk(KERN_ERR "WIMAX_GNL_OP_STATE_GET: can't find IFIDX "
+			"attribute\n");
+		goto error_no_wimax_dev;
+	}
+	ifindex = nla_get_u32(info->attrs[WIMAX_GNL_STGET_IFIDX]);
+	wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
+	if (wimax_dev == NULL)
+		goto error_no_wimax_dev;
+	dev = wimax_dev_to_dev(wimax_dev);
+	/* Execute the operation and send the result back to user space */
+	result = wimax_state_get(wimax_dev);
+	dev_put(wimax_dev->net_dev);
+error_no_wimax_dev:
+	d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
+	return result;
+}
+
+
+struct genl_ops wimax_gnl_state_get = {
+	.cmd = WIMAX_GNL_OP_STATE_GET,
+	.flags = GENL_ADMIN_PERM,
+	.policy = wimax_gnl_state_get_policy,
+	.doit = wimax_gnl_doit_state_get,
+	.dumpit = NULL,
+};