[NL80211]: add netlink interface to cfg80211

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/nl80211.h

@@ -6,18 +6,109 @@
  * Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
  */
 
+/**
+ * enum nl80211_commands - supported nl80211 commands
+ *
+ * @NL80211_CMD_UNSPEC: unspecified command to catch errors
+ *
+ * @NL80211_CMD_GET_WIPHY: request information about a wiphy or dump request
+ *	to get a list of all present wiphys.
+ * @NL80211_CMD_SET_WIPHY: set wiphy name, needs %NL80211_ATTR_WIPHY and
+ *	%NL80211_ATTR_WIPHY_NAME.
+ * @NL80211_CMD_NEW_WIPHY: Newly created wiphy, response to get request
+ *	or rename notification. Has attributes %NL80211_ATTR_WIPHY and
+ *	%NL80211_ATTR_WIPHY_NAME.
+ * @NL80211_CMD_DEL_WIPHY: Wiphy deleted. Has attributes
+ *	%NL80211_ATTR_WIPHY and %NL80211_ATTR_WIPHY_NAME.
+ *
+ * @NL80211_CMD_GET_INTERFACE: Request an interface's configuration;
+ *	either a dump request on a %NL80211_ATTR_WIPHY or a specific get
+ *	on an %NL80211_ATTR_IFINDEX is supported.
+ * @NL80211_CMD_SET_INTERFACE: Set type of a virtual interface, requires
+ *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_IFTYPE.
+ * @NL80211_CMD_NEW_INTERFACE: Newly created virtual interface or response
+ *	to %NL80211_CMD_GET_INTERFACE. Has %NL80211_ATTR_IFINDEX,
+ *	%NL80211_ATTR_WIPHY and %NL80211_ATTR_IFTYPE attributes. Can also
+ *	be sent from userspace to request creation of a new virtual interface,
+ *	then requires attributes %NL80211_ATTR_WIPHY, %NL80211_ATTR_IFTYPE and
+ *	%NL80211_ATTR_IFNAME.
+ * @NL80211_CMD_DEL_INTERFACE: Virtual interface was deleted, has attributes
+ *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_WIPHY. Can also be sent from
+ *	userspace to request deletion of a virtual interface, then requires
+ *	attribute %NL80211_ATTR_IFINDEX.
+ *
+ * @NL80211_CMD_MAX: highest used command number
+ * @__NL80211_CMD_AFTER_LAST: internal use
+ */
+enum nl80211_commands {
+/* don't change the order or add anything inbetween, this is ABI! */
+	NL80211_CMD_UNSPEC,
+
+	NL80211_CMD_GET_WIPHY,		/* can dump */
+	NL80211_CMD_SET_WIPHY,
+	NL80211_CMD_NEW_WIPHY,
+	NL80211_CMD_DEL_WIPHY,
+
+	NL80211_CMD_GET_INTERFACE,	/* can dump */
+	NL80211_CMD_SET_INTERFACE,
+	NL80211_CMD_NEW_INTERFACE,
+	NL80211_CMD_DEL_INTERFACE,
+
+	/* add commands here */
+
+	/* used to define NL80211_CMD_MAX below */
+	__NL80211_CMD_AFTER_LAST,
+	NL80211_CMD_MAX = __NL80211_CMD_AFTER_LAST - 1
+};
+
+
+/**
+ * enum nl80211_attrs - nl80211 netlink attributes
+ *
+ * @NL80211_ATTR_UNSPEC: unspecified attribute to catch errors
+ *
+ * @NL80211_ATTR_WIPHY: index of wiphy to operate on, cf.
+ *	/sys/class/ieee80211/<phyname>/index
+ * @NL80211_ATTR_WIPHY_NAME: wiphy name (used for renaming)
+ *
+ * @NL80211_ATTR_IFINDEX: network interface index of the device to operate on
+ * @NL80211_ATTR_IFNAME: network interface name
+ * @NL80211_ATTR_IFTYPE: type of virtual interface, see &enum nl80211_iftype
+ *
+ * @NL80211_ATTR_MAX: highest attribute number currently defined
+ * @__NL80211_ATTR_AFTER_LAST: internal use
+ */
+enum nl80211_attrs {
+/* don't change the order or add anything inbetween, this is ABI! */
+	NL80211_ATTR_UNSPEC,
+
+	NL80211_ATTR_WIPHY,
+	NL80211_ATTR_WIPHY_NAME,
+
+	NL80211_ATTR_IFINDEX,
+	NL80211_ATTR_IFNAME,
+	NL80211_ATTR_IFTYPE,
+
+	/* add attributes here, update the policy in nl80211.c */
+
+	__NL80211_ATTR_AFTER_LAST,
+	NL80211_ATTR_MAX = __NL80211_ATTR_AFTER_LAST - 1
+};
+
 /**
  * enum nl80211_iftype - (virtual) interface types
+ *
  * @NL80211_IFTYPE_UNSPECIFIED: unspecified type, driver decides
  * @NL80211_IFTYPE_ADHOC: independent BSS member
  * @NL80211_IFTYPE_STATION: managed BSS member
  * @NL80211_IFTYPE_AP: access point
  * @NL80211_IFTYPE_AP_VLAN: VLAN interface for access points
  * @NL80211_IFTYPE_WDS: wireless distribution interface
  * @NL80211_IFTYPE_MONITOR: monitor interface receiving all frames
+ * @NL80211_IFTYPE_MAX: highest interface type number currently defined
  * @__NL80211_IFTYPE_AFTER_LAST: internal use
  *
- * These values are used with the NL80211_ATTR_IFTYPE
+ * These values are used with the %NL80211_ATTR_IFTYPE
  * to set the type of an interface.
  *
  */
@@ -31,8 +122,8 @@ enum nl80211_iftype {
 	NL80211_IFTYPE_MONITOR,
 
 	/* keep last */
-	__NL80211_IFTYPE_AFTER_LAST
+	__NL80211_IFTYPE_AFTER_LAST,
+	NL80211_IFTYPE_MAX = __NL80211_IFTYPE_AFTER_LAST - 1
 };
-#define NL80211_IFTYPE_MAX (__NL80211_IFTYPE_AFTER_LAST - 1)
 
 #endif /* __LINUX_NL80211_H */

include/net/cfg80211.h

@@ -3,15 +3,15 @@
 
 #include <linux/netlink.h>
 #include <linux/skbuff.h>
+#include <linux/nl80211.h>
 #include <net/genetlink.h>
 
 /*
  * 802.11 configuration in-kernel interface
  *
- * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
  */
 
-
 /* Radiotap header iteration
  *   implemented in net/wireless/radiotap.c
  *   docs in Documentation/networking/radiotap-headers.txt
@@ -68,11 +68,16 @@ struct wiphy;
  * @add_virtual_intf: create a new virtual interface with the given name
  *
  * @del_virtual_intf: remove the virtual interface determined by ifindex.
+ *
+ * @change_virtual_intf: change type of virtual interface
+ *
  */
 struct cfg80211_ops {
 	int	(*add_virtual_intf)(struct wiphy *wiphy, char *name,
-				    unsigned int type);
+				    enum nl80211_iftype type);
 	int	(*del_virtual_intf)(struct wiphy *wiphy, int ifindex);
+	int	(*change_virtual_intf)(struct wiphy *wiphy, int ifindex,
+				       enum nl80211_iftype type);
 };
 
 #endif /* __NET_CFG80211_H */

include/net/iw_handler.h

@@ -431,7 +431,13 @@ struct iw_public_data {
  * Those may be called only within the kernel.
  */
 
-/* functions that may be called by driver modules */
+/* First : function strictly used inside the kernel */
+
+/* Handle /proc/net/wireless, called in net/code/dev.c */
+extern int dev_get_wireless_info(char * buffer, char **start, off_t offset,
+				 int length);
+
+/* Second : functions that may be called by driver modules */
 
 /* Send a single event to user space */
 extern void wireless_send_event(struct net_device *	dev,

net/mac80211/ieee80211_cfg.c

@@ -14,7 +14,7 @@
 #include "ieee80211_cfg.h"
 
 static int ieee80211_add_iface(struct wiphy *wiphy, char *name,
-			       unsigned int type)
+			       enum nl80211_iftype type)
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
 	int itype;

net/wireless/Kconfig

@@ -1,6 +1,19 @@
 config CFG80211
         tristate "Improved wireless configuration API"
 
+config NL80211
+	bool "nl80211 new netlink interface support"
+	depends CFG80211
+	default y
+	---help---
+         This option turns on the new netlink interface
+         (nl80211) support in cfg80211.
+
+         If =n, drivers using mac80211 will be configured via
+         wireless extension support provided by that subsystem.
+
+         If unsure, say Y.
+
 config WIRELESS_EXT
 	bool "Wireless extensions"
 	default n
@@ -10,7 +23,9 @@ config WIRELESS_EXT
 
 	  Wireless extensions will be replaced by cfg80211 and
 	  will be required only by legacy drivers that implement
-	  wireless extension handlers.
+	  wireless extension handlers. This option does not
+	  affect the wireless-extension backward compatibility
+	  code in cfg80211.
 
 	  Say N (if you can) unless you know you need wireless
 	  extensions for external modules.

net/wireless/Makefile

@@ -2,3 +2,4 @@ obj-$(CONFIG_WIRELESS_EXT) += wext.o
 obj-$(CONFIG_CFG80211) += cfg80211.o
 
 cfg80211-y += core.o sysfs.o radiotap.o
+cfg80211-$(CONFIG_NL80211) += nl80211.o

net/wireless/core.c

@@ -16,6 +16,7 @@
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include <net/wireless.h>
+#include "nl80211.h"
 #include "core.h"
 #include "sysfs.h"
 
@@ -36,6 +37,146 @@ static int wiphy_counter;
 /* for debugfs */
 static struct dentry *ieee80211_debugfs_dir;
 
+/* requires cfg80211_drv_mutex to be held! */
+static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy)
+{
+	struct cfg80211_registered_device *result = NULL, *drv;
+
+	list_for_each_entry(drv, &cfg80211_drv_list, list) {
+		if (drv->idx == wiphy) {
+			result = drv;
+			break;
+		}
+	}
+
+	return result;
+}
+
+/* requires cfg80211_drv_mutex to be held! */
+static struct cfg80211_registered_device *
+__cfg80211_drv_from_info(struct genl_info *info)
+{
+	int ifindex;
+	struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL;
+	struct net_device *dev;
+	int err = -EINVAL;
+
+	if (info->attrs[NL80211_ATTR_WIPHY]) {
+		bywiphy = cfg80211_drv_by_wiphy(
+				nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
+		err = -ENODEV;
+	}
+
+	if (info->attrs[NL80211_ATTR_IFINDEX]) {
+		ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
+		dev = dev_get_by_index(&init_net, ifindex);
+		if (dev) {
+			if (dev->ieee80211_ptr)
+				byifidx =
+					wiphy_to_dev(dev->ieee80211_ptr->wiphy);
+			dev_put(dev);
+		}
+		err = -ENODEV;
+	}
+
+	if (bywiphy && byifidx) {
+		if (bywiphy != byifidx)
+			return ERR_PTR(-EINVAL);
+		else
+			return bywiphy; /* == byifidx */
+	}
+	if (bywiphy)
+		return bywiphy;
+
+	if (byifidx)
+		return byifidx;
+
+	return ERR_PTR(err);
+}
+
+struct cfg80211_registered_device *
+cfg80211_get_dev_from_info(struct genl_info *info)
+{
+	struct cfg80211_registered_device *drv;
+
+	mutex_lock(&cfg80211_drv_mutex);
+	drv = __cfg80211_drv_from_info(info);
+
+	/* if it is not an error we grab the lock on
+	 * it to assure it won't be going away while
+	 * we operate on it */
+	if (!IS_ERR(drv))
+		mutex_lock(&drv->mtx);
+
+	mutex_unlock(&cfg80211_drv_mutex);
+
+	return drv;
+}
+
+struct cfg80211_registered_device *
+cfg80211_get_dev_from_ifindex(int ifindex)
+{
+	struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
+	struct net_device *dev;
+
+	mutex_lock(&cfg80211_drv_mutex);
+	dev = dev_get_by_index(&init_net, ifindex);
+	if (!dev)
+		goto out;
+	if (dev->ieee80211_ptr) {
+		drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
+		mutex_lock(&drv->mtx);
+	} else
+		drv = ERR_PTR(-ENODEV);
+	dev_put(dev);
+ out:
+	mutex_unlock(&cfg80211_drv_mutex);
+	return drv;
+}
+
+void cfg80211_put_dev(struct cfg80211_registered_device *drv)
+{
+	BUG_ON(IS_ERR(drv));
+	mutex_unlock(&drv->mtx);
+}
+
+int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
+			char *newname)
+{
+	int idx, taken = -1, result, digits;
+
+	/* prohibit calling the thing phy%d when %d is not its number */
+	sscanf(newname, PHY_NAME "%d%n", &idx, &taken);
+	if (taken == strlen(newname) && idx != rdev->idx) {
+		/* count number of places needed to print idx */
+		digits = 1;
+		while (idx /= 10)
+			digits++;
+		/*
+		 * deny the name if it is phy<idx> where <idx> is printed
+		 * without leading zeroes. taken == strlen(newname) here
+		 */
+		if (taken == strlen(PHY_NAME) + digits)
+			return -EINVAL;
+	}
+
+	/* this will check for collisions */
+	result = device_rename(&rdev->wiphy.dev, newname);
+	if (result)
+		return result;
+
+	if (!debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
+			    rdev->wiphy.debugfsdir,
+			    rdev->wiphy.debugfsdir->d_parent,
+			    newname))
+		printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
+		       newname);
+
+	nl80211_notify_dev_rename(rdev);
+
+	return 0;
+}
+
 /* exported functions */
 
 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
@@ -204,10 +345,16 @@ static int cfg80211_init(void)
 	if (err)
 		goto out_fail_notifier;
 
+	err = nl80211_init();
+	if (err)
+		goto out_fail_nl80211;
+
 	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 
 	return 0;
 
+out_fail_nl80211:
+	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 out_fail_notifier:
 	wiphy_sysfs_exit();
 out_fail_sysfs:
@@ -218,6 +365,7 @@ subsys_initcall(cfg80211_init);
 static void cfg80211_exit(void)
 {
 	debugfs_remove(ieee80211_debugfs_dir);
+	nl80211_exit();
 	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 	wiphy_sysfs_exit();
 }