From 01c2f53329b06e51c9cc9a9bca802120808dbe76 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Thu, 19 Nov 2020 09:28:51 -0800
Subject: [PATCH] [radio-spinel] verify host is connected to an RCP (#5822)

This commit addresses an issue in `RadioSpinel::Init()` to correctly
verify that device is connected to an RCP (i.e., capability list
includes `SPINEL_CAP_CONFIG_RADIO`) and if not then exit (`DieNow()`)
with `OT_EXIT_RADIO_SPINEL_INCOMPATIBLE` code.

It also simplifies the checking of capabilities for log stream support
(`SPINEL_CAP_OPENTHREAD_LOG_METADATA`) by changing the code to get and
process the `SPINEL_PROP_RADIO_CAPS` list only once from `IsRcp()`.
---
 src/lib/spinel/radio_spinel_impl.hpp | 42 +++++++++++-----------------
 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/src/lib/spinel/radio_spinel_impl.hpp b/src/lib/spinel/radio_spinel_impl.hpp
index 678f07244..5339f0288 100644
--- a/src/lib/spinel/radio_spinel_impl.hpp
+++ b/src/lib/spinel/radio_spinel_impl.hpp
@@ -221,10 +221,18 @@ void RadioSpinel<InterfaceType, ProcessContextType>::Init(bool aResetRadio, bool
     SuccessOrExit(error = Get(SPINEL_PROP_NCP_VERSION, SPINEL_DATATYPE_UTF8_S, mVersion, sizeof(mVersion)));
     SuccessOrExit(error = Get(SPINEL_PROP_HWADDR, SPINEL_DATATYPE_EUI64_S, mIeeeEui64.m8));
 
-    if (!IsRcp() && aRestoreDatasetFromNcp)
+    if (!IsRcp())
     {
-        DieNow((RestoreDatasetFromNcp() == OT_ERROR_NONE) ? OT_EXIT_SUCCESS : OT_EXIT_FAILURE);
+        uint8_t exitCode = OT_EXIT_RADIO_SPINEL_INCOMPATIBLE;
+
+        if (aRestoreDatasetFromNcp)
+        {
+            exitCode = (RestoreDatasetFromNcp() == OT_ERROR_NONE) ? OT_EXIT_SUCCESS : OT_EXIT_FAILURE;
+        }
+
+        DieNow(exitCode);
     }
+
     SuccessOrDie(CheckRadioCapabilities());
 
     mRxRadioFrame.mPsdu  = mRxPsdu;
@@ -287,6 +295,11 @@ bool RadioSpinel<InterfaceType, ProcessContextType>::IsRcp(void)
             isRcp = true;
         }
 
+        if (capability == SPINEL_CAP_OPENTHREAD_LOG_METADATA)
+        {
+            mSupportsLogStream = true;
+        }
+
         capsData += unpacked;
         capsLength -= static_cast<spinel_size_t>(unpacked);
     }
@@ -309,11 +322,8 @@ otError RadioSpinel<InterfaceType, ProcessContextType>::CheckRadioCapabilities(v
 #endif
         OT_RADIO_CAPS_ACK_TIMEOUT | OT_RADIO_CAPS_TRANSMIT_RETRIES | OT_RADIO_CAPS_CSMA_BACKOFF;
 
-    otError        error = OT_ERROR_NONE;
-    unsigned int   radioCaps;
-    uint8_t        capsBuffer[kCapsBufferSize];
-    const uint8_t *capsData   = capsBuffer;
-    spinel_size_t  capsLength = sizeof(capsBuffer);
+    otError      error = OT_ERROR_NONE;
+    unsigned int radioCaps;
 
     SuccessOrExit(error = Get(SPINEL_PROP_RADIO_CAPS, SPINEL_DATATYPE_UINT_PACKED_S, &radioCaps));
     mRadioCaps = static_cast<otRadioCaps>(radioCaps);
@@ -332,24 +342,6 @@ otError RadioSpinel<InterfaceType, ProcessContextType>::CheckRadioCapabilities(v
         DieNow(OT_EXIT_RADIO_SPINEL_INCOMPATIBLE);
     }
 
-    SuccessOrExit(error = Get(SPINEL_PROP_CAPS, SPINEL_DATATYPE_DATA_S, capsBuffer, &capsLength));
-    while (capsLength > 0)
-    {
-        unsigned int   capability;
-        spinel_ssize_t unpacked =
-            spinel_datatype_unpack(capsData, capsLength, SPINEL_DATATYPE_UINT_PACKED_S, &capability);
-
-        VerifyOrDie(unpacked > 0, OT_EXIT_RADIO_SPINEL_INCOMPATIBLE);
-
-        if (capability == SPINEL_CAP_OPENTHREAD_LOG_METADATA)
-        {
-            mSupportsLogStream = true;
-        }
-
-        capsData += unpacked;
-        capsLength -= static_cast<spinel_size_t>(unpacked);
-    }
-
 exit:
     return error;
 }