mac80211: add explicit monitor interface if needed From: Johannes Berg The queue mapping redesign that I'm planning to do will break pure injection unless we handle monitor interfaces explicitly. One possible option would be to have the driver tell mac80211 about monitor mode queues etc., but that would duplicate the API since we already need to have queue assignments handled per virtual interface. So in order to solve this, have a virtual monitor interface that is added whenever all active vifs are monitors. We could also use the state of one of the monitor interfaces, but managing that would be complicated, so allocate separate state. Signed-off-by: Johannes Berg --- drivers/net/wireless/mac80211_hwsim.c | 3 + include/net/mac80211.h | 6 ++- net/mac80211/driver-ops.h | 3 - net/mac80211/ieee80211_i.h | 3 + net/mac80211/iface.c | 64 ++++++++++++++++++++++++++++++++++ net/mac80211/pm.c | 4 ++ net/mac80211/tx.c | 7 ++- net/mac80211/util.c | 10 +++++ 8 files changed, 94 insertions(+), 6 deletions(-) --- a/net/mac80211/ieee80211_i.h 2012-03-26 12:25:17.000000000 +0200 +++ b/net/mac80211/ieee80211_i.h 2012-03-26 14:33:02.000000000 +0200 @@ -1077,6 +1077,9 @@ struct ieee80211_local { struct net_device napi_dev; struct napi_struct napi; + + /* virtual monitor interface */ + struct ieee80211_sub_if_data __rcu *monitor_sdata; }; static inline struct ieee80211_sub_if_data * --- a/net/mac80211/pm.c 2012-03-10 09:17:06.000000000 +0100 +++ b/net/mac80211/pm.c 2012-03-26 16:03:43.000000000 +0200 @@ -127,6 +127,10 @@ int __ieee80211_suspend(struct ieee80211 drv_remove_interface(local, sdata); } + sdata = rtnl_dereference(local->monitor_sdata); + if (sdata) + drv_remove_interface(local, sdata); + /* stop hardware - this must stop RX */ if (local->open_count) ieee80211_stop_device(local); --- a/include/net/mac80211.h 2012-03-26 12:25:20.000000000 +0200 +++ b/include/net/mac80211.h 2012-03-26 16:05:49.000000000 +0200 @@ -1173,6 +1173,10 @@ enum sta_notify_cmd { * @IEEE80211_HW_SCAN_WHILE_IDLE: The device can do hw scan while * being idle (i.e. mac80211 doesn't have to go idle-off during the * the scan). + * + * @IEEE80211_HW_WANT_MONITOR_VIF: The driver would like to be informed of + * a virtual monitor interface when monitor interfaces are the only + * active interfaces. */ enum ieee80211_hw_flags { IEEE80211_HW_HAS_RATE_CONTROL = 1<<0, @@ -1189,7 +1193,7 @@ enum ieee80211_hw_flags { IEEE80211_HW_PS_NULLFUNC_STACK = 1<<11, IEEE80211_HW_SUPPORTS_DYNAMIC_PS = 1<<12, IEEE80211_HW_MFP_CAPABLE = 1<<13, - /* reuse bit 14 */ + IEEE80211_HW_WANT_MONITOR_VIF = 1<<14, IEEE80211_HW_SUPPORTS_STATIC_SMPS = 1<<15, IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS = 1<<16, IEEE80211_HW_SUPPORTS_UAPSD = 1<<17, --- a/net/mac80211/iface.c 2012-03-26 13:23:41.000000000 +0200 +++ b/net/mac80211/iface.c 2012-03-26 16:12:55.000000000 +0200 @@ -169,6 +169,58 @@ void ieee80211_adjust_monitor_flags(stru #undef ADJUST } +static int ieee80211_add_virtual_monitor(struct ieee80211_local *local) +{ + struct ieee80211_sub_if_data *sdata; + int ret; + + if (!(local->hw.flags & IEEE80211_HW_WANT_MONITOR_VIF)) + return 0; + + if (local->monitor_sdata) + return 0; + + sdata = kzalloc(sizeof(*sdata) + local->hw.vif_data_size, GFP_KERNEL); + if (!sdata) + return -ENOMEM; + + /* set up data */ + sdata->vif.type = NL80211_IFTYPE_MONITOR; + snprintf(sdata->name, IFNAMSIZ, "%s-monitor", + wiphy_name(local->hw.wiphy)); + + ret = drv_add_interface(local, sdata); + if (WARN_ON(ret)) { + /* ok .. stupid driver, it asked for this! */ + kfree(sdata); + return ret; + } + + rcu_assign_pointer(local->monitor_sdata, sdata); + + return 0; +} + +static void ieee80211_del_virtual_monitor(struct ieee80211_local *local) +{ + struct ieee80211_sub_if_data *sdata; + + if (!(local->hw.flags & IEEE80211_HW_WANT_MONITOR_VIF)) + return; + + sdata = rtnl_dereference(local->monitor_sdata); + + if (WARN_ON(!sdata)) + return; + + rcu_assign_pointer(local->monitor_sdata, NULL); + synchronize_net(); + + drv_remove_interface(local, sdata); + + kfree(sdata); +} + /* * 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 @@ -266,6 +318,12 @@ static int ieee80211_do_open(struct net_ break; } + if (local->monitors == 0 && local->open_count == 0) { + res = ieee80211_add_virtual_monitor(local); + if (res) + return res; + } + /* must be before the call to ieee80211_configure_filter */ local->monitors++; if (local->monitors == 1) { @@ -280,6 +338,8 @@ static int ieee80211_do_open(struct net_ break; default: if (coming_up) { + ieee80211_del_virtual_monitor(local); + res = drv_add_interface(local, sdata); if (res) goto err_stop; @@ -511,6 +571,7 @@ static void ieee80211_do_stop(struct iee if (local->monitors == 0) { local->hw.conf.flags &= ~IEEE80211_CONF_MONITOR; hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR; + ieee80211_del_virtual_monitor(local); } ieee80211_adjust_monitor_flags(sdata, -1); @@ -584,6 +645,9 @@ static void ieee80211_do_stop(struct iee } } spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); + + if (local->monitors == local->open_count && local->monitors > 0) + ieee80211_add_virtual_monitor(local); } static int ieee80211_stop(struct net_device *dev) --- a/net/mac80211/util.c 2012-03-26 12:25:22.000000000 +0200 +++ b/net/mac80211/util.c 2012-03-26 16:04:50.000000000 +0200 @@ -1214,6 +1214,16 @@ int ieee80211_reconfig(struct ieee80211_ IEEE80211_TPT_LEDTRIG_FL_RADIO, 0); /* add interfaces */ + sdata = rtnl_dereference(local->monitor_sdata); + if (sdata) { + res = drv_add_interface(local, sdata); + if (WARN_ON(res)) { + rcu_assign_pointer(local->monitor_sdata, NULL); + synchronize_net(); + kfree(sdata); + } + } + list_for_each_entry(sdata, &local->interfaces, list) { if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN && sdata->vif.type != NL80211_IFTYPE_MONITOR && --- a/net/mac80211/tx.c 2012-03-26 12:25:23.000000000 +0200 +++ b/net/mac80211/tx.c 2012-03-26 16:07:46.000000000 +0200 @@ -1284,8 +1284,11 @@ static bool __ieee80211_tx(struct ieee80 switch (sdata->vif.type) { case NL80211_IFTYPE_MONITOR: - sdata = NULL; - vif = NULL; + sdata = rcu_dereference(local->monitor_sdata); + if (sdata) + vif = &sdata->vif; + else + vif = NULL; break; case NL80211_IFTYPE_AP_VLAN: sdata = container_of(sdata->bss, --- a/drivers/net/wireless/mac80211_hwsim.c 2012-03-15 20:43:13.000000000 +0100 +++ b/drivers/net/wireless/mac80211_hwsim.c 2012-03-26 16:24:36.000000000 +0200 @@ -1789,7 +1789,8 @@ static int __init init_mac80211_hwsim(vo IEEE80211_HW_SIGNAL_DBM | IEEE80211_HW_SUPPORTS_STATIC_SMPS | IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS | - IEEE80211_HW_AMPDU_AGGREGATION; + IEEE80211_HW_AMPDU_AGGREGATION | + IEEE80211_HW_WANT_MONITOR_VIF; hw->wiphy->flags |= WIPHY_FLAG_SUPPORTS_TDLS; --- a/net/mac80211/driver-ops.h 2012-03-26 12:25:20.000000000 +0200 +++ b/net/mac80211/driver-ops.h 2012-03-26 16:29:15.000000000 +0200 @@ -98,8 +98,7 @@ static inline int drv_add_interface(stru might_sleep(); - if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_AP_VLAN || - sdata->vif.type == NL80211_IFTYPE_MONITOR)) + if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) return -EINVAL; trace_drv_add_interface(local, sdata);