mac80211: support runtime interface type changes
Add support to mac80211 for changing the interface
type even when the interface is UP, if the driver
supports it.
To achieve this
* add a new driver callback for switching,
* split some of the interface up/down code out
into new functions (do_open/do_stop), and
* maintain an own __SDATA_RUNNING bit that will
not be set during interface type, so that any
other code doesn't use the interface.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f82b18e..5de1ca3 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -52,9 +52,6 @@
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
int ret;
- if (ieee80211_sdata_running(sdata))
- return -EBUSY;
-
ret = ieee80211_if_change_type(sdata, type);
if (ret)
return ret;
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 14123dc..6064b7b 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -54,6 +54,20 @@
return ret;
}
+static inline int drv_change_interface(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ enum nl80211_iftype type)
+{
+ int ret;
+
+ might_sleep();
+
+ trace_drv_change_interface(local, sdata, type);
+ ret = local->ops->change_interface(&local->hw, &sdata->vif, type);
+ trace_drv_return_int(local, ret);
+ return ret;
+}
+
static inline void drv_remove_interface(struct ieee80211_local *local,
struct ieee80211_vif *vif)
{
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index b5a9558..f6f3d89 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -136,6 +136,31 @@
)
);
+TRACE_EVENT(drv_change_interface,
+ TP_PROTO(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ enum nl80211_iftype type),
+
+ TP_ARGS(local, sdata, type),
+
+ TP_STRUCT__entry(
+ LOCAL_ENTRY
+ VIF_ENTRY
+ __field(u32, new_type)
+ ),
+
+ TP_fast_assign(
+ LOCAL_ASSIGN;
+ VIF_ASSIGN;
+ __entry->new_type = type;
+ ),
+
+ TP_printk(
+ LOCAL_PR_FMT VIF_PR_FMT " new type:%d",
+ LOCAL_PR_ARG, VIF_PR_ARG, __entry->new_type
+ )
+);
+
TRACE_EVENT(drv_remove_interface,
TP_PROTO(struct ieee80211_local *local, struct ieee80211_sub_if_data *sdata),
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f648377..d529bd5 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -472,6 +472,16 @@
IEEE80211_SDATA_DONT_BRIDGE_PACKETS = BIT(3),
};
+/**
+ * enum ieee80211_sdata_state_bits - virtual interface state bits
+ * @SDATA_STATE_RUNNING: virtual interface is up & running; this
+ * mirrors netif_running() but is separate for interface type
+ * change handling while the interface is up
+ */
+enum ieee80211_sdata_state_bits {
+ SDATA_STATE_RUNNING,
+};
+
struct ieee80211_sub_if_data {
struct list_head list;
@@ -485,6 +495,8 @@
unsigned int flags;
+ unsigned long state;
+
int drop_unencrypted;
char name[IFNAMSIZ];
@@ -1087,7 +1099,7 @@
static inline bool ieee80211_sdata_running(struct ieee80211_sub_if_data *sdata)
{
- return netif_running(sdata->dev);
+ return test_bit(SDATA_STATE_RUNNING, &sdata->state);
}
/* tx handling */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index cba3d80..c1cc200 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -148,7 +148,12 @@
return 0;
}
-static int ieee80211_open(struct net_device *dev)
+/*
+ * NOTE: Be very careful when changing this function, it must NOT return
+ * an error on interface type changes that have been pre-checked, so most
+ * checks should be in ieee80211_check_concurrent_iface.
+ */
+static int ieee80211_do_open(struct net_device *dev, bool coming_up)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ieee80211_local *local = sdata->local;
@@ -157,15 +162,6 @@
int res;
u32 hw_reconf_flags = 0;
- /* fail early if user set an invalid address */
- if (!is_zero_ether_addr(dev->dev_addr) &&
- !is_valid_ether_addr(dev->dev_addr))
- return -EADDRNOTAVAIL;
-
- res = ieee80211_check_concurrent_iface(sdata, sdata->vif.type);
- if (res)
- return res;
-
switch (sdata->vif.type) {
case NL80211_IFTYPE_WDS:
if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
@@ -258,9 +254,11 @@
netif_carrier_on(dev);
break;
default:
- res = drv_add_interface(local, &sdata->vif);
- if (res)
- goto err_stop;
+ if (coming_up) {
+ res = drv_add_interface(local, &sdata->vif);
+ if (res)
+ goto err_stop;
+ }
if (ieee80211_vif_is_mesh(&sdata->vif)) {
local->fif_other_bss++;
@@ -316,7 +314,9 @@
hw_reconf_flags |= __ieee80211_recalc_idle(local);
mutex_unlock(&local->mtx);
- local->open_count++;
+ if (coming_up)
+ local->open_count++;
+
if (hw_reconf_flags) {
ieee80211_hw_config(local, hw_reconf_flags);
/*
@@ -331,6 +331,8 @@
netif_tx_start_all_queues(dev);
+ set_bit(SDATA_STATE_RUNNING, &sdata->state);
+
return 0;
err_del_interface:
drv_remove_interface(local, &sdata->vif);
@@ -344,19 +346,38 @@
return res;
}
-static int ieee80211_stop(struct net_device *dev)
+static int ieee80211_open(struct net_device *dev)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ int err;
+
+ /* fail early if user set an invalid address */
+ if (!is_zero_ether_addr(dev->dev_addr) &&
+ !is_valid_ether_addr(dev->dev_addr))
+ return -EADDRNOTAVAIL;
+
+ err = ieee80211_check_concurrent_iface(sdata, sdata->vif.type);
+ if (err)
+ return err;
+
+ return ieee80211_do_open(dev, true);
+}
+
+static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
+ bool going_down)
+{
struct ieee80211_local *local = sdata->local;
unsigned long flags;
struct sk_buff *skb, *tmp;
u32 hw_reconf_flags = 0;
int i;
+ clear_bit(SDATA_STATE_RUNNING, &sdata->state);
+
/*
* Stop TX on this interface first.
*/
- netif_tx_stop_all_queues(dev);
+ netif_tx_stop_all_queues(sdata->dev);
/*
* Purge work for this interface.
@@ -394,11 +415,12 @@
if (sdata->vif.type == NL80211_IFTYPE_AP)
local->fif_pspoll--;
- netif_addr_lock_bh(dev);
+ netif_addr_lock_bh(sdata->dev);
spin_lock_bh(&local->filter_lock);
- __hw_addr_unsync(&local->mc_list, &dev->mc, dev->addr_len);
+ __hw_addr_unsync(&local->mc_list, &sdata->dev->mc,
+ sdata->dev->addr_len);
spin_unlock_bh(&local->filter_lock);
- netif_addr_unlock_bh(dev);
+ netif_addr_unlock_bh(sdata->dev);
ieee80211_configure_filter(local);
@@ -432,7 +454,8 @@
WARN_ON(!list_empty(&sdata->u.ap.vlans));
}
- local->open_count--;
+ if (going_down)
+ local->open_count--;
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
@@ -504,7 +527,8 @@
*/
ieee80211_free_keys(sdata);
- drv_remove_interface(local, &sdata->vif);
+ if (going_down)
+ drv_remove_interface(local, &sdata->vif);
}
sdata->bss = NULL;
@@ -540,6 +564,13 @@
}
}
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
+}
+
+static int ieee80211_stop(struct net_device *dev)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+ ieee80211_do_stop(sdata, true);
return 0;
}
@@ -857,9 +888,72 @@
ieee80211_debugfs_add_netdev(sdata);
}
+static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata,
+ enum nl80211_iftype type)
+{
+ struct ieee80211_local *local = sdata->local;
+ int ret, err;
+
+ ASSERT_RTNL();
+
+ if (!local->ops->change_interface)
+ return -EBUSY;
+
+ switch (sdata->vif.type) {
+ case NL80211_IFTYPE_AP:
+ case NL80211_IFTYPE_STATION:
+ case NL80211_IFTYPE_ADHOC:
+ /*
+ * Could maybe also all others here?
+ * Just not sure how that interacts
+ * with the RX/config path e.g. for
+ * mesh.
+ */
+ break;
+ default:
+ return -EBUSY;
+ }
+
+ switch (type) {
+ case NL80211_IFTYPE_AP:
+ case NL80211_IFTYPE_STATION:
+ case NL80211_IFTYPE_ADHOC:
+ /*
+ * Could probably support everything
+ * but WDS here (WDS do_open can fail
+ * under memory pressure, which this
+ * code isn't prepared to handle).
+ */
+ break;
+ default:
+ return -EBUSY;
+ }
+
+ ret = ieee80211_check_concurrent_iface(sdata, type);
+ if (ret)
+ return ret;
+
+ ieee80211_do_stop(sdata, false);
+
+ ieee80211_teardown_sdata(sdata->dev);
+
+ ret = drv_change_interface(local, sdata, type);
+ if (ret)
+ type = sdata->vif.type;
+
+ ieee80211_setup_sdata(sdata, type);
+
+ err = ieee80211_do_open(sdata->dev, false);
+ WARN(err, "type change: do_open returned %d", err);
+
+ return ret;
+}
+
int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
enum nl80211_iftype type)
{
+ int ret;
+
ASSERT_RTNL();
if (type == sdata->vif.type)
@@ -870,18 +964,15 @@
type == NL80211_IFTYPE_ADHOC)
return -EOPNOTSUPP;
- /*
- * We could, here, on changes between IBSS/STA/MESH modes,
- * invoke an MLME function instead that disassociates etc.
- * and goes into the requested mode.
- */
-
- if (ieee80211_sdata_running(sdata))
- return -EBUSY;
-
- /* Purge and reset type-dependent state. */
- ieee80211_teardown_sdata(sdata->dev);
- ieee80211_setup_sdata(sdata, type);
+ if (ieee80211_sdata_running(sdata)) {
+ ret = ieee80211_runtime_change_iftype(sdata, type);
+ if (ret)
+ return ret;
+ } else {
+ /* Purge and reset type-dependent state. */
+ ieee80211_teardown_sdata(sdata->dev);
+ ieee80211_setup_sdata(sdata, type);
+ }
/* reset some values that shouldn't be kept across type changes */
sdata->vif.bss_conf.basic_rates =