From 5b7c5e7c09311c14dfb8a5b2e7ed213872efc421 Mon Sep 17 00:00:00 2001
From: Benjamin Berg <bberg@redhat.com>
Date: Wed, 21 Apr 2021 21:24:30 +0200
Subject: [PATCH] device: Check for device overheating and abort when needed

Check if a device is too hot. If it is too hot already, refuse
operation. If it becomes too hot while an operation is ongoing, then
cancel the action and force a FP_DEVICE_ERROR_TOO_HOT return value.
---
 libfprint/fp-device.c  | 24 ++++++++++++++++++++++++
 libfprint/fpi-device.c | 15 +++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/libfprint/fp-device.c b/libfprint/fp-device.c
index 99399c6..8d508d3 100644
--- a/libfprint/fp-device.c
+++ b/libfprint/fp-device.c
@@ -986,6 +986,12 @@ fp_device_enroll (FpDevice           *device,
   setup_task_cancellable (device);
 
   fpi_device_update_temp (device, TRUE);
+  if (priv->temp_current == FP_TEMPERATURE_HOT)
+    {
+      g_task_return_error (task, fpi_device_error_new (FP_DEVICE_ERROR_TOO_HOT));
+      fpi_device_update_temp (device, FALSE);
+      return;
+    }
 
   data = g_new0 (FpEnrollData, 1);
   data->print = g_object_ref_sink (template_print);
@@ -1081,6 +1087,12 @@ fp_device_verify (FpDevice           *device,
   setup_task_cancellable (device);
 
   fpi_device_update_temp (device, TRUE);
+  if (priv->temp_current == FP_TEMPERATURE_HOT)
+    {
+      g_task_return_error (task, fpi_device_error_new (FP_DEVICE_ERROR_TOO_HOT));
+      fpi_device_update_temp (device, FALSE);
+      return;
+    }
 
   data = g_new0 (FpMatchData, 1);
   data->enrolled_print = g_object_ref (enrolled_print);
@@ -1202,6 +1214,12 @@ fp_device_identify (FpDevice           *device,
   setup_task_cancellable (device);
 
   fpi_device_update_temp (device, TRUE);
+  if (priv->temp_current == FP_TEMPERATURE_HOT)
+    {
+      g_task_return_error (task, fpi_device_error_new (FP_DEVICE_ERROR_TOO_HOT));
+      fpi_device_update_temp (device, FALSE);
+      return;
+    }
 
   data = g_new0 (FpMatchData, 1);
   /* We cannot store the gallery directly, because the ptr array may not own
@@ -1321,6 +1339,12 @@ fp_device_capture (FpDevice           *device,
   setup_task_cancellable (device);
 
   fpi_device_update_temp (device, TRUE);
+  if (priv->temp_current == FP_TEMPERATURE_HOT)
+    {
+      g_task_return_error (task, fpi_device_error_new (FP_DEVICE_ERROR_TOO_HOT));
+      fpi_device_update_temp (device, FALSE);
+      return;
+    }
 
   priv->wait_for_finger = wait_for_finger;
 
diff --git a/libfprint/fpi-device.c b/libfprint/fpi-device.c
index 5704622..cfbd167 100644
--- a/libfprint/fpi-device.c
+++ b/libfprint/fpi-device.c
@@ -1806,6 +1806,21 @@ fpi_device_update_temp (FpDevice *device, gboolean is_active)
   if (priv->temp_current != old_temp)
     g_object_notify (G_OBJECT (device), "temperature");
 
+  /* If the device is HOT, then do an internal cancellation of long running tasks. */
+  if (priv->temp_current == FP_TEMPERATURE_HOT)
+    {
+      if (priv->current_action == FPI_DEVICE_ACTION_ENROLL ||
+          priv->current_action == FPI_DEVICE_ACTION_VERIFY ||
+          priv->current_action == FPI_DEVICE_ACTION_IDENTIFY ||
+          priv->current_action == FPI_DEVICE_ACTION_CAPTURE)
+        {
+          if (!priv->current_cancellation_reason)
+            priv->current_cancellation_reason = fpi_device_error_new (FP_DEVICE_ERROR_TOO_HOT);
+
+          g_cancellable_cancel (priv->current_cancellable);
+        }
+    }
+
   g_clear_pointer (&priv->temp_timeout, g_source_destroy);
 
   if (next_threshold < 0)