mac80211-hwsim: Add support for HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE

Add support for new attribute HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE
which can be set by the user space component. The attribute
will cause the kernel to destroy all those radios that were
created by a process if that process dies. The old behaviour
i.e., radios are persistent is still the default.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 40 insertions, 3 deletions

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index f1a0794b33f3..6ffe07323e6e 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -412,6 +412,9 @@ struct mac80211_hwsim_data {
         struct mac_address addresses[2];
         int channels, idx;
         bool use_chanctx;
+        bool destroy_on_close;
+        struct work_struct destroy_work;
+        u32 portid;
 
         struct ieee80211_channel *tmp_chan;
         struct delayed_work roc_done;
@@ -496,6 +499,7 @@ static const struct nla_policy hwsim_genl_policy[HWSIM_ATTR_MAX + 1] = {
         [HWSIM_ATTR_REG_CUSTOM_REG] = { .type = NLA_U32 },
         [HWSIM_ATTR_REG_STRICT_REG] = { .type = NLA_FLAG },
         [HWSIM_ATTR_SUPPORT_P2P_DEVICE] = { .type = NLA_FLAG },
+        [HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE] = { .type = NLA_FLAG },
 };
 
 static void mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
@@ -1947,7 +1951,8 @@ static struct ieee80211_ops mac80211_hwsim_mchan_ops;
 static int mac80211_hwsim_create_radio(int channels, const char *reg_alpha2,
                                        const struct ieee80211_regdomain *regd,
                                        bool reg_strict, bool p2p_device,
-                                       bool use_chanctx)
+                                       bool use_chanctx, bool destroy_on_close,
+                                       u32 portid)
 {
         int err;
         u8 addr[ETH_ALEN];
@@ -2007,6 +2012,8 @@ static int mac80211_hwsim_create_radio(int channels, const char *reg_alpha2,
         data->channels = channels;
         data->use_chanctx = use_chanctx;
         data->idx = idx;
+        data->destroy_on_close = destroy_on_close;
+        data->portid = portid;
 
         if (data->use_chanctx) {
                 hw->wiphy->max_scan_ssids = 255;
@@ -2434,6 +2441,7 @@ static int hwsim_create_radio_nl(struct sk_buff *msg, struct genl_info *info)
         const struct ieee80211_regdomain *regd = NULL;
         bool reg_strict = info->attrs[HWSIM_ATTR_REG_STRICT_REG];
         bool p2p_device = info->attrs[HWSIM_ATTR_SUPPORT_P2P_DEVICE];
+        bool destroy_on_close = info->attrs[HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE];
         bool use_chanctx;
 
         if (info->attrs[HWSIM_ATTR_CHANNELS])
@@ -2456,7 +2464,8 @@ static int hwsim_create_radio_nl(struct sk_buff *msg, struct genl_info *info)
         }
 
         return mac80211_hwsim_create_radio(chans, alpha2, regd, reg_strict,
-                                           p2p_device, use_chanctx);
+                                           p2p_device, use_chanctx,
+                                           destroy_on_close, info->snd_portid);
 }
 
 static int hwsim_destroy_radio_nl(struct sk_buff *msg, struct genl_info *info)
@@ -2514,6 +2523,29 @@ static const struct genl_ops hwsim_ops[] = {
         },
 };
 
+static void destroy_radio(struct work_struct *work)
+{
+        struct mac80211_hwsim_data *data =
+                container_of(work, struct mac80211_hwsim_data, destroy_work);
+
+        mac80211_hwsim_destroy_radio(data);
+}
+
+static void remove_user_radios(u32 portid)
+{
+        struct mac80211_hwsim_data *entry, *tmp;
+
+        spin_lock_bh(&hwsim_radio_lock);
+        list_for_each_entry_safe(entry, tmp, &hwsim_radios, list) {
+                if (entry->destroy_on_close && entry->portid == portid) {
+                        list_del(&entry->list);
+                        INIT_WORK(&entry->destroy_work, destroy_radio);
+                        schedule_work(&entry->destroy_work);
+                }
+        }
+        spin_unlock_bh(&hwsim_radio_lock);
+}
+
 static int mac80211_hwsim_netlink_notify(struct notifier_block *nb,
                                          unsigned long state,
                                          void *_notify)
@@ -2523,6 +2555,8 @@ static int mac80211_hwsim_netlink_notify(struct notifier_block *nb,
         if (state != NETLINK_URELEASE)
                 return NOTIFY_DONE;
 
+        remove_user_radios(notify->portid);
+
         if (notify->portid == wmediumd_portid) {
                 printk(KERN_INFO "mac80211_hwsim: wmediumd released netlink"
                        " socket, switching to perfect channel medium\n");
@@ -2676,7 +2710,7 @@ static int __init init_mac80211_hwsim(void)
                 err = mac80211_hwsim_create_radio(channels, reg_alpha2,
                                                   regd, reg_strict,
                                                   support_p2p_device,
-                                                  channels > 1);
+                                                  channels > 1, false, 0);
                 if (err < 0)
                         goto out_free_radios;
         }
diff --git a/drivers/net/wireless/mac80211_hwsim.h b/drivers/net/wireless/mac80211_hwsim.h
index c9d0315575ba..b96d8670a703 100644
--- a/drivers/net/wireless/mac80211_hwsim.h
+++ b/drivers/net/wireless/mac80211_hwsim.h
@@ -111,6 +111,8 @@ enum {
  * @HWSIM_ATTR_USE_CHANCTX: used with the %HWSIM_CMD_CREATE_RADIO
  *      command to force use of channel contexts even when only a
  *      single channel is supported
+ * @HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE: used with the %HWSIM_CMD_CREATE_RADIO
+ *      command to force radio removal when process that created the radio dies
  * @__HWSIM_ATTR_MAX: enum limit
  */
 
@@ -132,6 +134,7 @@ enum {
         HWSIM_ATTR_REG_STRICT_REG,
         HWSIM_ATTR_SUPPORT_P2P_DEVICE,
         HWSIM_ATTR_USE_CHANCTX,
+        HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE,
         __HWSIM_ATTR_MAX,
 };
 #define HWSIM_ATTR_MAX (__HWSIM_ATTR_MAX - 1)