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 <d9eca20059088ad8bdaac70d7d98811166839b27.camel@hadess.net>
In-Reply-To: <d9eca20059088ad8bdaac70d7d98811166839b27.camel@hadess.net>
From:   Andrey Batyiev <batyiev@gmail.com>
Date:   Wed, 8 Jul 2020 18:53:00 +0300
Message-ID: <CAEQQxWyz-9iDU5Cs_NjHm81A6kdr0WUXPggp_2DTHeVVAQXUZQ@mail.gmail.com>
Subject: Re: Temporary device removal during discovery
To:     Bastien Nocera <hadess@hadess.net>
Cc:     linux-bluetooth <linux-bluetooth@vger.kernel.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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Hi Bastien, everyone,

I've made a patch to the bluez, so the temporary devices are routinely
purged based on their last_seen attribute.

What do you think about such solution?

Thanks,
    Andrey


diff --git a/src/adapter.c b/src/adapter.c
index 529002b02..101b03633 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -88,6 +88,7 @@

#define CONN_SCAN_TIMEOUT (3)
#define IDLE_DISCOV_TIMEOUT (5)
+#define TEMP_DEV_REAPER_INTERVAL (30)
#define TEMP_DEV_TIMEOUT (3 * 60)
#define BONDING_TIMEOUT (2 * 60)

@@ -1491,18 +1492,18 @@ static gboolean remove_temp_devices(gpointer user_data)

       DBG("%s", adapter->path);

-       adapter->temp_devices_timeout = 0;
-
       for (l = adapter->devices; l != NULL; l = next) {
               struct btd_device *dev = l->data;

               next = g_slist_next(l);

-               if (device_is_temporary(dev) && !btd_device_is_connected(dev))
+               if (device_is_temporary(dev) &&
+                   !btd_device_is_connected(dev) &&
+                   device_last_seen_delta(dev) > TEMP_DEV_TIMEOUT)
                       btd_adapter_remove_device(adapter, dev);
       }

-       return FALSE;
+       return TRUE;
}

static void discovery_cleanup(struct btd_adapter *adapter)
@@ -1516,11 +1517,6 @@ static void discovery_cleanup(struct
btd_adapter *adapter)
               adapter->discovery_idle_timeout = 0;
       }

-       if (adapter->temp_devices_timeout > 0) {
-               g_source_remove(adapter->temp_devices_timeout);
-               adapter->temp_devices_timeout = 0;
-       }
-
       g_slist_free_full(adapter->discovery_found,
                                               invalidate_rssi_and_tx_power);
       adapter->discovery_found = NULL;
@@ -1536,9 +1532,6 @@ static void discovery_cleanup(struct btd_adapter *adapter)
               if (device_is_temporary(dev) && !device_is_connectable(dev))
                       btd_adapter_remove_device(adapter, dev);
       }
-
-       adapter->temp_devices_timeout = g_timeout_add_seconds(TEMP_DEV_TIMEOUT,
-                                               remove_temp_devices, adapter);
}

static void discovery_free(void *user_data)
@@ -2405,7 +2398,7 @@ static bool parse_pathloss(DBusMessageIter *value,
       return true;
}

-static bool parse_transport(DBusMessageIter *value,
+static bool parse_transport(DBusMessageIter *value,
                                       struct discovery_filter *filter)
{
       char *transport_str;
@@ -5362,6 +5355,11 @@ static void adapter_free(gpointer user_data)
               adapter->passive_scan_timeout = 0;
       }

+       if (adapter->temp_devices_timeout > 0) {
+               g_source_remove(adapter->temp_devices_timeout);
+               adapter->temp_devices_timeout = 0;
+       }
+
       if (adapter->load_ltks_timeout > 0)
               g_source_remove(adapter->load_ltks_timeout);

@@ -6343,6 +6341,9 @@ static struct btd_adapter *btd_adapter_new(uint16_t index)

       adapter->auths = g_queue_new();

+       adapter->temp_devices_timeout =
g_timeout_add_seconds(TEMP_DEV_REAPER_INTERVAL,
+                                               remove_temp_devices, adapter);
+
       return btd_adapter_ref(adapter);
}

diff --git a/src/device.c b/src/device.c
index 0deee2707..cebbabab2 100644
--- a/src/device.c
+++ b/src/device.c
@@ -4240,6 +4240,15 @@ void device_update_last_seen(struct btd_device
*device, uint8_t bdaddr_type)
               device->le_seen = time(NULL);
}

+time_t device_last_seen_delta(struct btd_device *device)
+{
+       const time_t now = time(NULL);
+       const time_t bredr_time = now - device->bredr_seen;
+       const time_t le_time = now - device->le_seen;
+
+       return bredr_time < le_time ? bredr_time : le_time;
+}
+
/* It is possible that we have two device objects for the same device in
 * case it has first been discovered over BR/EDR and has a private
 * address when discovered over LE for the first time. In such a case we
diff --git a/src/device.h b/src/device.h
index cb8d884e8..75fd3ec60 100644
--- a/src/device.h
+++ b/src/device.h
@@ -44,6 +44,7 @@ void device_update_addr(struct btd_device *device,
const bdaddr_t *bdaddr,
void device_set_bredr_support(struct btd_device *device);
void device_set_le_support(struct btd_device *device, uint8_t bdaddr_type);
void device_update_last_seen(struct btd_device *device, uint8_t bdaddr_type);
+time_t device_last_seen_delta(struct btd_device *device);
void device_merge_duplicate(struct btd_device *dev, struct btd_device *dup);
uint32_t btd_device_get_class(struct btd_device *device);
uint16_t btd_device_get_vendor(struct btd_device *device);