adapter: Catch polling errors

Receiving a NFC_EVENT_TARGETS_FOUND with a NULL payload means the driver
entered an error state. This is handled by checking if the devices and
targets arrays are empty from the GET_TARGET finish handler.
In the polling error case, neard resets the adapter and starts polling
again.

The polling error handler runs asynchrounously for the D-Bus properties
toggle to be exported properly.

3 files changed, 59 insertions, 2 deletions

diff --git a/src/adapter.c b/src/adapter.c
index 52f11a6..98331a5 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -854,6 +854,50 @@ int __near_adapter_remove_target(uint32_t idx, uint32_t target_idx)
 	return 0;
 }
 
+static gboolean poll_error(gpointer user_data)
+{
+	struct near_adapter *adapter = user_data;
+
+	DBG("adapter %d", adapter->idx);
+
+	/*
+	 * Resettting the adapter upon polling errors.
+	 * This could be handled through a configuration setting.
+	 */
+	__near_netlink_adapter_enable(adapter->idx, false);
+	__near_netlink_adapter_enable(adapter->idx, true);
+
+	adapter_start_poll(adapter);
+
+	return FALSE;
+}
+
+int __near_adapter_get_targets_done(uint32_t idx)
+{
+	struct near_adapter *adapter;
+
+	DBG("idx %d", idx);
+
+	adapter = g_hash_table_lookup(adapter_hash, GINT_TO_POINTER(idx));
+	if (!adapter)
+		return -ENODEV;
+
+	if (g_hash_table_size(adapter->devices) > 0)
+		return 0;
+
+	if (g_hash_table_size(adapter->tags) > 0)
+		return 0;
+
+	near_error("No targets found - Polling error");
+
+	adapter->polling = false;
+	polling_changed(adapter);
+
+	g_idle_add(poll_error, adapter);
+
+	return 0;
+}
+
 int __near_adapter_add_device(uint32_t idx, uint8_t *nfcid, uint8_t nfcid_len)
 {
 	struct near_adapter *adapter;
diff --git a/src/near.h b/src/near.h
index cf00675..c75aefe 100644
--- a/src/near.h
+++ b/src/near.h
@@ -86,6 +86,7 @@ int __near_adapter_add_target(uint32_t idx, uint32_t target_idx,
 			uint32_t protocols, uint16_t sens_res, uint8_t sel_res,
 			uint8_t *nfcid, uint8_t nfcid_len);
 int __near_adapter_remove_target(uint32_t idx, uint32_t target_idx);
+int __near_adapter_get_targets_done(uint32_t idx);
 int __near_adapter_add_device(uint32_t idx, uint8_t *nfcid, uint8_t nfcid_len);
 int __near_adapter_remove_device(uint32_t idx);
 int __near_adapter_set_dep_state(uint32_t idx, bool dep);
diff --git a/src/netlink.c b/src/netlink.c
index 936f65a..65e42a8 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -492,6 +492,17 @@ static int get_targets_handler(struct nl_msg *n, void *arg)
 	return 0;
 }
 
+static int get_targets_finish_handler(struct nl_msg *n, void *arg)
+{
+	uint32_t adapter_idx;
+
+	DBG("");
+
+	adapter_idx = *((uint32_t *)arg);
+
+	return __near_adapter_get_targets_done(adapter_idx);
+}
+
 static int nfc_netlink_event_targets_found(struct genlmsghdr *gnlh)
 {
 	struct nlattr *attr[NFC_ATTR_MAX + 1];
@@ -526,8 +537,9 @@ static int nfc_netlink_event_targets_found(struct genlmsghdr *gnlh)
 
 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, adapter_idx);
 
-	err = nl_send_msg(nfc_state->cmd_sock, msg,
-				get_targets_handler, &adapter_idx);
+	err = __nl_send_msg(nfc_state->cmd_sock, msg,
+				get_targets_handler, get_targets_finish_handler,
+								&adapter_idx);
 
 nla_put_failure:
 	nlmsg_free(msg);