Fix mac address get for dnssd (#15221)

* Fix mac address get for dnssd * Stop asserting that the primary mac getting returns a default - it should not * remove one more use of the default mac * Use DRBG_get_bytes to get a random mac * Remove the NO_ERROR assumption for getting primary mac. Emulators have no active IP interface to get a mac from
project-chip · Oct 17, 2023 · 1312908 · 1312908
1 parent b0113eb
commit 1312908
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Showing 3 changed files with 19 additions and 30 deletions.
diff --git a/src/app/server/Dnssd.cpp b/src/app/server/Dnssd.cpp
@@ -256,7 +256,11 @@ CHIP_ERROR DnssdServer::AdvertiseOperational()
         {
             uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
             MutableByteSpan mac(macBuffer);
-            chip::DeviceLayer::ConfigurationMgr().GetPrimaryMACAddress(mac);
+            if (chip::DeviceLayer::ConfigurationMgr().GetPrimaryMACAddress(mac) != CHIP_NO_ERROR)
+            {
+                ChipLogError(Discovery, "Failed to get primary mac address of device. Generating a random one.");
+                Crypto::DRBG_get_bytes(macBuffer, sizeof(macBuffer));
+            }
 
             const auto advertiseParameters = chip::Dnssd::OperationalAdvertisingParameters()
                                                  .SetPeerId(fabricInfo.GetPeerId())
@@ -293,7 +297,11 @@ CHIP_ERROR DnssdServer::Advertise(bool commissionableNode, chip::Dnssd::Commissi
 
     uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
     MutableByteSpan mac(macBuffer);
-    chip::DeviceLayer::ConfigurationMgr().GetPrimaryMACAddress(mac);
+    if (chip::DeviceLayer::ConfigurationMgr().GetPrimaryMACAddress(mac) != CHIP_NO_ERROR)
+    {
+        ChipLogError(Discovery, "Failed to get primary mac address of device. Generating a random one.");
+        Crypto::DRBG_get_bytes(macBuffer, sizeof(macBuffer));
+    }
     advertiseParameters.SetMac(mac);
 
     uint16_t value;

diff --git a/src/include/platform/internal/GenericConfigurationManagerImpl.cpp b/src/include/platform/internal/GenericConfigurationManagerImpl.cpp
@@ -136,18 +136,15 @@ CHIP_ERROR GenericConfigurationManagerImpl<ConfigClass>::GetPrimaryMACAddress(Mu
         ChipLogDetail(DeviceLayer, "Using Thread extended MAC for hostname.");
         return CHIP_NO_ERROR;
     }
-#else
-    if (DeviceLayer::ConfigurationMgr().GetPrimaryWiFiMACAddress(buf.data()) == CHIP_NO_ERROR)
+#endif
+
+    if (chip::DeviceLayer::ConfigurationMgr().GetPrimaryWiFiMACAddress(buf.data()) == CHIP_NO_ERROR)
     {
         ChipLogDetail(DeviceLayer, "Using wifi MAC for hostname");
         return CHIP_NO_ERROR;
     }
-#endif
 
-    ChipLogError(DeviceLayer, "MAC is not known, using a default.");
-    uint8_t temp[ConfigurationManager::kMaxMACAddressLength] = { 0xEE, 0xAA, 0xBA, 0xDA, 0xBA, 0xD0, 0xDD, 0xCA };
-    memcpy(buf.data(), temp, buf.size());
-    return CHIP_NO_ERROR;
+    return CHIP_ERROR_NOT_FOUND;
 }
 
 template <class ConfigClass>

diff --git a/src/platform/tests/TestConfigurationMgr.cpp b/src/platform/tests/TestConfigurationMgr.cpp
@@ -187,8 +187,7 @@ static void TestConfigurationMgr_Breadcrumb(nlTestSuite * inSuite, void * inCont
 
 static void TestConfigurationMgr_GetPrimaryMACAddress(nlTestSuite * inSuite, void * inContext)
 {
-    CHIP_ERROR err                     = CHIP_NO_ERROR;
-    const uint8_t defaultMacAddress[8] = { 0xEE, 0xAA, 0xBA, 0xDA, 0xBA, 0xD0, 0xDD, 0xCA };
+    CHIP_ERROR err = CHIP_NO_ERROR;
     uint8_t macBuffer8Bytes[8];
     uint8_t macBuffer6Bytes[6];
     MutableByteSpan mac8Bytes(macBuffer8Bytes);
@@ -199,32 +198,17 @@ static void TestConfigurationMgr_GetPrimaryMACAddress(nlTestSuite * inSuite, voi
     {
         NL_TEST_ASSERT(inSuite, err == CHIP_ERROR_INVALID_ARGUMENT);
     }
-    else
-    {
-        NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
-
-        // Verify default MAC address value
-        NL_TEST_ASSERT(inSuite,
-                       strncmp(reinterpret_cast<char *>(mac8Bytes.data()), reinterpret_cast<const char *>(defaultMacAddress),
-                               mac8Bytes.size()) == 0);
-    }
 
     err = ConfigurationMgr().GetPrimaryMACAddress(mac6Bytes);
     if (mac6Bytes.size() != ConfigurationManager::kPrimaryMACAddressLength)
     {
         NL_TEST_ASSERT(inSuite, err == CHIP_ERROR_INVALID_ARGUMENT);
     }
-    else
-    {
-        NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-#ifndef __MBED__
-        // Verify default MAC address value
-        NL_TEST_ASSERT(inSuite,
-                       strncmp(reinterpret_cast<char *>(mac6Bytes.data()), reinterpret_cast<const char *>(defaultMacAddress),
-                               mac6Bytes.size()) == 0);
-#endif
-    }
+    // NOTICE for above:
+    //   no validation for CHIP_NO_ERROR:
+    //    - there is no guarantee in CI that a valid IP address exists,
+    //      expecially if running in emulators (zephyr and qemu)
 }
 
 /**