wifi(implementation): Generate randomized mac address
Generate random MAC address on the first creation of AP iface after
reboot.
Bug: 78353419
Test: ./hardware/interfaces/wifi/1.3/default/tests/runtests.sh
Test: Manually verified that the AP MAC address & BSSID changes on every
reboot.
Change-Id: Ie9984ec72b2dfec9b7de7a9ef33b9e9ebfaf945c
diff --git a/wifi/1.3/default/Android.mk b/wifi/1.3/default/Android.mk
index 7ebea4f..199ea3b 100644
--- a/wifi/1.3/default/Android.mk
+++ b/wifi/1.3/default/Android.mk
@@ -148,7 +148,8 @@
tests/mock_wifi_mode_controller.cpp \
tests/ringbuffer_unit_tests.cpp \
tests/wifi_ap_iface_unit_tests.cpp \
- tests/wifi_chip_unit_tests.cpp
+ tests/wifi_chip_unit_tests.cpp \
+ tests/wifi_iface_util_unit_tests.cpp
LOCAL_STATIC_LIBRARIES := \
libgmock \
libgtest \
diff --git a/wifi/1.3/default/tests/wifi_iface_util_unit_tests.cpp b/wifi/1.3/default/tests/wifi_iface_util_unit_tests.cpp
new file mode 100644
index 0000000..e5758fa
--- /dev/null
+++ b/wifi/1.3/default/tests/wifi_iface_util_unit_tests.cpp
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/logging.h>
+#include <android-base/macros.h>
+#include <gmock/gmock.h>
+
+#undef NAN
+#include "wifi_iface_util.h"
+
+using testing::Test;
+
+namespace {
+constexpr uint8_t kValidUnicastLocallyAssignedMacAddressMask = 0x02;
+
+bool isValidUnicastLocallyAssignedMacAddress(
+ const std::array<uint8_t, 6>& mac_address) {
+ uint8_t first_byte = mac_address[0];
+ return (first_byte & 0x3) == kValidUnicastLocallyAssignedMacAddressMask;
+}
+} // namespace
+
+namespace android {
+namespace hardware {
+namespace wifi {
+namespace V1_3 {
+namespace implementation {
+class WifiIfaceUtilTest : public Test {
+ protected:
+ iface_util::WifiIfaceUtil iface_util_;
+};
+
+TEST_F(WifiIfaceUtilTest, GetOrCreateRandomMacAddress) {
+ auto mac_address = iface_util_.getOrCreateRandomMacAddress();
+ ASSERT_TRUE(isValidUnicastLocallyAssignedMacAddress(mac_address));
+
+ // All further calls should return the same MAC address.
+ ASSERT_EQ(mac_address, iface_util_.getOrCreateRandomMacAddress());
+ ASSERT_EQ(mac_address, iface_util_.getOrCreateRandomMacAddress());
+}
+} // namespace implementation
+} // namespace V1_3
+} // namespace wifi
+} // namespace hardware
+} // namespace android
diff --git a/wifi/1.3/default/wifi_iface_util.cpp b/wifi/1.3/default/wifi_iface_util.cpp
index 164aca7..5d61271 100644
--- a/wifi/1.3/default/wifi_iface_util.cpp
+++ b/wifi/1.3/default/wifi_iface_util.cpp
@@ -14,12 +14,24 @@
* limitations under the License.
*/
+#include <cstddef>
+#include <iostream>
+#include <limits>
+#include <random>
+
#include <android-base/logging.h>
#include <android-base/macros.h>
#include <private/android_filesystem_config.h>
+#undef NAN
#include "wifi_iface_util.h"
+namespace {
+// Constants to set the local bit & clear the multicast bit.
+constexpr uint8_t kMacAddressMulticastMask = 0x01;
+constexpr uint8_t kMacAddressLocallyAssignedMask = 0x02;
+} // namespace
+
namespace android {
namespace hardware {
namespace wifi {
@@ -62,8 +74,19 @@
}
std::array<uint8_t, 6> WifiIfaceUtil::createRandomMacAddress() {
- // TODO: Generate random MAC address here.
- return {};
+ std::array<uint8_t, 6> address = {};
+ std::random_device rd;
+ std::default_random_engine engine(rd());
+ std::uniform_int_distribution<uint8_t> dist(
+ std::numeric_limits<uint8_t>::min(),
+ std::numeric_limits<uint8_t>::max());
+ for (size_t i = 0; i < address.size(); i++) {
+ address[i] = dist(engine);
+ }
+ // Set the local bit and clear the multicast bit.
+ address[0] |= kMacAddressLocallyAssignedMask;
+ address[0] &= ~kMacAddressMulticastMask;
+ return address;
}
} // namespace iface_util
} // namespace implementation