From 704232c2718c9d4b3375ec15a14fc0397970c449 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 23 Apr 2007 12:20:05 -0700 Subject: [WIRELESS] cfg80211: New wireless config infrastructure. This patch creates the core cfg80211 code along with some sysfs bits. This is a stripped down version to allow mac80211 to function, but doesn't include any configuration yet except for creating and removing virtual interfaces. This patch includes the nl80211 header file but it only contains the interface types which the cfg80211 interface for creating virtual interfaces relies on. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- net/wireless/core.c | 209 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 net/wireless/core.c (limited to 'net/wireless/core.c') diff --git a/net/wireless/core.c b/net/wireless/core.c new file mode 100644 index 0000000..532e1e0 --- /dev/null +++ b/net/wireless/core.c @@ -0,0 +1,209 @@ +/* + * This is the linux wireless configuration interface. + * + * Copyright 2006, 2007 Johannes Berg + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "core.h" +#include "sysfs.h" + +/* name for sysfs, %d is appended */ +#define PHY_NAME "phy" + +MODULE_AUTHOR("Johannes Berg"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("wireless configuration support"); + +/* RCU might be appropriate here since we usually + * only read the list, and that can happen quite + * often because we need to do it for each command */ +LIST_HEAD(cfg80211_drv_list); +DEFINE_MUTEX(cfg80211_drv_mutex); +static int wiphy_counter; + +/* for debugfs */ +static struct dentry *ieee80211_debugfs_dir; + +/* exported functions */ + +struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv) +{ + struct cfg80211_registered_device *drv; + int alloc_size; + + alloc_size = sizeof(*drv) + sizeof_priv; + + drv = kzalloc(alloc_size, GFP_KERNEL); + if (!drv) + return NULL; + + drv->ops = ops; + + mutex_lock(&cfg80211_drv_mutex); + + if (unlikely(wiphy_counter<0)) { + /* ugh, wrapped! */ + kfree(drv); + return NULL; + } + drv->idx = wiphy_counter; + + /* give it a proper name */ + snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE, + PHY_NAME "%d", drv->idx); + + /* now increase counter for the next time */ + wiphy_counter++; + mutex_unlock(&cfg80211_drv_mutex); + + mutex_init(&drv->mtx); + mutex_init(&drv->devlist_mtx); + INIT_LIST_HEAD(&drv->netdev_list); + + device_initialize(&drv->wiphy.dev); + drv->wiphy.dev.class = &ieee80211_class; + drv->wiphy.dev.platform_data = drv; + + return &drv->wiphy; +} +EXPORT_SYMBOL(wiphy_new); + +int wiphy_register(struct wiphy *wiphy) +{ + struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); + int res; + + mutex_lock(&cfg80211_drv_mutex); + + + res = device_add(&drv->wiphy.dev); + if (res) + goto out_unlock; + + list_add(&drv->list, &cfg80211_drv_list); + + /* add to debugfs */ + drv->wiphy.debugfsdir = + debugfs_create_dir(wiphy_name(&drv->wiphy), + ieee80211_debugfs_dir); + + res = 0; +out_unlock: + mutex_unlock(&cfg80211_drv_mutex); + return res; +} +EXPORT_SYMBOL(wiphy_register); + +void wiphy_unregister(struct wiphy *wiphy) +{ + struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); + + mutex_lock(&cfg80211_drv_mutex); + + /* hold registered driver mutex during list removal as well + * to make sure no commands are in progress at the moment */ + mutex_lock(&drv->mtx); + list_del(&drv->list); + mutex_unlock(&drv->mtx); + + device_del(&drv->wiphy.dev); + debugfs_remove(drv->wiphy.debugfsdir); + + mutex_unlock(&cfg80211_drv_mutex); +} +EXPORT_SYMBOL(wiphy_unregister); + +void cfg80211_dev_free(struct cfg80211_registered_device *drv) +{ + mutex_destroy(&drv->mtx); + mutex_destroy(&drv->devlist_mtx); + kfree(drv); +} + +void wiphy_free(struct wiphy *wiphy) +{ + put_device(&wiphy->dev); +} +EXPORT_SYMBOL(wiphy_free); + +static int cfg80211_netdev_notifier_call(struct notifier_block * nb, + unsigned long state, + void *ndev) +{ + struct net_device *dev = ndev; + struct cfg80211_registered_device *rdev; + + if (!dev->ieee80211_ptr) + return 0; + + rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); + + switch (state) { + case NETDEV_REGISTER: + mutex_lock(&rdev->devlist_mtx); + list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list); + if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj, + "phy80211")) { + printk(KERN_ERR "wireless: failed to add phy80211 " + "symlink to netdev!\n"); + } + dev->ieee80211_ptr->netdev = dev; + mutex_unlock(&rdev->devlist_mtx); + break; + case NETDEV_UNREGISTER: + mutex_lock(&rdev->devlist_mtx); + if (!list_empty(&dev->ieee80211_ptr->list)) { + sysfs_remove_link(&dev->dev.kobj, "phy80211"); + list_del_init(&dev->ieee80211_ptr->list); + } + mutex_unlock(&rdev->devlist_mtx); + break; + } + + return 0; +} + +static struct notifier_block cfg80211_netdev_notifier = { + .notifier_call = cfg80211_netdev_notifier_call, +}; + +static int cfg80211_init(void) +{ + int err = wiphy_sysfs_init(); + if (err) + goto out_fail_sysfs; + + err = register_netdevice_notifier(&cfg80211_netdev_notifier); + if (err) + goto out_fail_notifier; + + ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL); + + return 0; + +out_fail_notifier: + wiphy_sysfs_exit(); +out_fail_sysfs: + return err; +} +module_init(cfg80211_init); + +static void cfg80211_exit(void) +{ + debugfs_remove(ieee80211_debugfs_dir); + unregister_netdevice_notifier(&cfg80211_netdev_notifier); + wiphy_sysfs_exit(); +} +module_exit(cfg80211_exit); -- cgit v1.1 From a4d73ee168eeaed3baea86542ad42e1fd7e192d3 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 26 Apr 2007 20:50:35 -0700 Subject: [WIRELESS] cfg80211: Fix locking in wiphy_new. This patch fixes the locking in wiphy new. Ingo Oeser noticed that locking in the error case was wrong and also suggested this fix. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- net/wireless/core.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'net/wireless/core.c') diff --git a/net/wireless/core.c b/net/wireless/core.c index 532e1e0..24a21add 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -53,21 +53,25 @@ struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv) mutex_lock(&cfg80211_drv_mutex); - if (unlikely(wiphy_counter<0)) { + drv->idx = wiphy_counter; + + /* now increase counter for the next device unless + * it has wrapped previously */ + if (wiphy_counter >= 0) + wiphy_counter++; + + mutex_unlock(&cfg80211_drv_mutex); + + if (unlikely(drv->idx < 0)) { /* ugh, wrapped! */ kfree(drv); return NULL; } - drv->idx = wiphy_counter; /* give it a proper name */ snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE, PHY_NAME "%d", drv->idx); - /* now increase counter for the next time */ - wiphy_counter++; - mutex_unlock(&cfg80211_drv_mutex); - mutex_init(&drv->mtx); mutex_init(&drv->devlist_mtx); INIT_LIST_HEAD(&drv->netdev_list); -- cgit v1.1 From f16bfc1c0958ff340a02779ab139b03fb5ba6e82 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 26 Apr 2007 20:51:12 -0700 Subject: [WIRELESS] cfg80211: Clarify locking comment. This patch clarifies the comment about locking in wiphy_unregister. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- net/wireless/core.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'net/wireless/core.c') diff --git a/net/wireless/core.c b/net/wireless/core.c index 24a21add..7eabd55 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -91,7 +91,6 @@ int wiphy_register(struct wiphy *wiphy) mutex_lock(&cfg80211_drv_mutex); - res = device_add(&drv->wiphy.dev); if (res) goto out_unlock; @@ -114,14 +113,26 @@ void wiphy_unregister(struct wiphy *wiphy) { struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); + /* protect the device list */ mutex_lock(&cfg80211_drv_mutex); - /* hold registered driver mutex during list removal as well - * to make sure no commands are in progress at the moment */ + BUG_ON(!list_empty(&drv->netdev_list)); + + /* + * Try to grab drv->mtx. If a command is still in progress, + * hopefully the driver will refuse it since it's tearing + * down the device already. We wait for this command to complete + * before unlinking the item from the list. + * Note: as codified by the BUG_ON above we cannot get here if + * a virtual interface is still associated. Hence, we can only + * get to lock contention here if userspace issues a command + * that identified the hardware by wiphy index. + */ mutex_lock(&drv->mtx); - list_del(&drv->list); + /* unlock again before freeing */ mutex_unlock(&drv->mtx); + list_del(&drv->list); device_del(&drv->wiphy.dev); debugfs_remove(drv->wiphy.debugfsdir); -- cgit v1.1