[trel] refactor Peer class and enhance PeerInfo parsing (openthread#11477)

This commit contains smaller changes related to the TREL `Peer` class
and the parsing of TXT data within the `PeerInfo` class.

The `Peer` class definition is now moved into its own `trel_peer.hpp`
and `trel_peer.cpp` header and source files, separating it from the
`Trel::Interface` class. Additionally, the `Log()` method within the
`Peer` class has been enhanced (now using an `Action` enum).

The `PeerInfo` class remains a nested class of `Interface` and now
provides a `ParseTxtData()` method to parse the included TXT data
entries.

Author: abtink

src/core/BUILD.gn

@@ -617,6 +617,8 @@ openthread_core_files = [
   "radio/trel_link.hpp",
   "radio/trel_packet.cpp",
   "radio/trel_packet.hpp",
+  "radio/trel_peer.cpp",
+  "radio/trel_peer.hpp",
   "thread/address_resolver.cpp",
   "thread/address_resolver.hpp",
   "thread/announce_begin_server.cpp",

src/core/CMakeLists.txt

@@ -203,6 +203,7 @@ set(COMMON_SOURCES
     radio/trel_interface.cpp
     radio/trel_link.cpp
     radio/trel_packet.cpp
+    radio/trel_peer.cpp
     thread/address_resolver.cpp
     thread/announce_begin_server.cpp
     thread/announce_sender.cpp

src/core/radio/trel_interface.cpp

@@ -115,7 +115,7 @@ void Interface::ClearPeerList(void)
     mPeerPool.FreeAll();
 }
 
-Interface::Peer *Interface::FindPeer(const Mac::ExtAddress &aExtAddress) { return mPeerList.FindMatching(aExtAddress); }
+Peer *Interface::FindPeer(const Mac::ExtAddress &aExtAddress) { return mPeerList.FindMatching(aExtAddress); }
 
 void Interface::NotifyPeerSocketAddressDifference(const Ip6::SockAddr &aPeerSockAddr, const Ip6::SockAddr &aRxSockAddr)
 {
@@ -175,13 +175,13 @@ extern "C" void otPlatTrelHandleDiscoveredPeerInfo(otInstance *aInstance, const
     Instance &instance = AsCoreType(aInstance);
 
     VerifyOrExit(instance.IsInitialized());
-    instance.Get<Interface>().HandleDiscoveredPeerInfo(*static_cast<const Interface::Peer::Info *>(aInfo));
+    instance.Get<Interface>().HandleDiscoveredPeerInfo(*static_cast<const Interface::PeerInfo *>(aInfo));
 
 exit:
     return;
 }
 
-void Interface::HandleDiscoveredPeerInfo(const Peer::Info &aInfo)
+void Interface::HandleDiscoveredPeerInfo(const PeerInfo &aInfo)
 {
     Peer                  *entry;
     Mac::ExtAddress        extAddress;
@@ -190,7 +190,7 @@ void Interface::HandleDiscoveredPeerInfo(const Peer::Info &aInfo)
 
     VerifyOrExit(mInitialized && mEnabled);
 
-    SuccessOrExit(ParsePeerInfoTxtData(aInfo, extAddress, extPanId));
+    SuccessOrExit(aInfo.ParseTxtData(extAddress, extPanId));
 
     VerifyOrExit(extAddress != Get<Mac::Mac>().GetExtAddress());
 
@@ -238,15 +238,13 @@ void Interface::HandleDiscoveredPeerInfo(const Peer::Info &aInfo)
     entry->SetExtPanId(extPanId);
     entry->SetSockAddr(aInfo.GetSockAddr());
 
-    entry->Log(isNew ? "Added" : "Updated");
+    entry->Log(isNew ? Peer::kAdded : Peer::kUpdated);
 
 exit:
     return;
 }
 
-Error Interface::ParsePeerInfoTxtData(const Peer::Info       &aInfo,
-                                      Mac::ExtAddress        &aExtAddress,
-                                      MeshCoP::ExtendedPanId &aExtPanId) const
+Error Interface::PeerInfo::ParseTxtData(Mac::ExtAddress &aExtAddress, MeshCoP::ExtendedPanId &aExtPanId) const
 {
     Error                   error;
     Dns::TxtEntry           entry;
@@ -256,7 +254,7 @@ Error Interface::ParsePeerInfoTxtData(const Peer::Info       &aInfo,
 
     aExtPanId.Clear();
 
-    iterator.Init(aInfo.GetTxtData(), aInfo.GetTxtLength());
+    iterator.Init(mTxtData, mTxtLength);
 
     while ((error = iterator.GetNextEntry(entry)) == kErrorNone)
     {
@@ -296,7 +294,7 @@ Error Interface::ParsePeerInfoTxtData(const Peer::Info       &aInfo,
     return error;
 }
 
-Interface::Peer *Interface::GetNewPeerEntry(void)
+Peer *Interface::GetNewPeerEntry(void)
 {
     Peer *peerEntry;
 
@@ -342,7 +340,7 @@ Interface::Peer *Interface::GetNewPeerEntry(void)
 
 void Interface::RemovePeerEntry(Peer &aEntry)
 {
-    aEntry.Log("Removing");
+    aEntry.Log(Peer::kRemoving);
 
     if (mPeerList.Remove(aEntry) == kErrorNone)
     {
@@ -415,7 +413,7 @@ void Interface::HandleReceived(uint8_t *aBuffer, uint16_t aLength, const Ip6::So
     return;
 }
 
-const Interface::Peer *Interface::GetNextPeer(PeerIterator &aIterator) const
+const Peer *Interface::GetNextPeer(PeerIterator &aIterator) const
 {
     const Peer *entry = static_cast<const Peer *>(aIterator);
 
@@ -439,14 +437,6 @@ uint16_t Interface::GetNumberOfPeers(void) const
     return count;
 }
 
-void Interface::Peer::Log(const char *aAction) const
-{
-    OT_UNUSED_VARIABLE(aAction);
-
-    LogInfo("%s peer mac:%s, xpan:%s, %s", aAction, GetExtAddress().ToString().AsCString(),
-            GetExtPanId().ToString().AsCString(), GetSockAddr().ToString().AsCString());
-}
-
 } // namespace Trel
 } // namespace ot
 

src/core/radio/trel_interface.hpp

@@ -46,16 +46,14 @@
 #include "common/pool.hpp"
 #include "common/tasklet.hpp"
 #include "common/time.hpp"
-#include "mac/mac_types.hpp"
-#include "net/ip6_address.hpp"
-#include "net/socket.hpp"
 #include "radio/trel_packet.hpp"
-#include "thread/mle_types.hpp"
+#include "radio/trel_peer.hpp"
 
 namespace ot {
 namespace Trel {
 
 class Link;
+class Interface;
 
 extern "C" void otPlatTrelHandleReceived(otInstance       *aInstance,
                                          uint8_t          *aBuffer,
@@ -81,84 +79,6 @@ class Interface : public InstanceLocator
     friend void otPlatTrelHandleDiscoveredPeerInfo(otInstance *aInstance, const otPlatTrelPeerInfo *aInfo);
 
 public:
-    /**
-     * Represents information about a discovered TREL peer.
-     */
-    class Peer : public otTrelPeer, public LinkedListEntry<Peer>
-    {
-        friend class Interface;
-        friend class LinkedListEntry<Peer>;
-        friend void otPlatTrelHandleDiscoveredPeerInfo(otInstance *aInstance, const otPlatTrelPeerInfo *aInfo);
-
-    public:
-        /**
-         * Returns the Extended MAC Address of the discovered TREL peer.
-         *
-         * @returns The Extended MAC Address of the TREL peer.
-         */
-        const Mac::ExtAddress &GetExtAddress(void) const { return static_cast<const Mac::ExtAddress &>(mExtAddress); }
-
-        /**
-         * Returns the Extended PAN Identifier of the discovered TREL peer.
-         *
-         * @returns The Extended PAN Identifier of the TREL peer.
-         */
-        const MeshCoP::ExtendedPanId &GetExtPanId(void) const
-        {
-            return static_cast<const MeshCoP::ExtendedPanId &>(mExtPanId);
-        }
-
-        /**
-         * Returns the IPv6 socket address of the discovered TREL peer.
-         *
-         * @returns The IPv6 socket address of the TREL peer.
-         */
-        const Ip6::SockAddr &GetSockAddr(void) const { return static_cast<const Ip6::SockAddr &>(mSockAddr); }
-
-        /**
-         * Set the IPv6 socket address of the discovered TREL peer.
-         *
-         * @param[in] aSockAddr   The IPv6 socket address.
-         */
-        void SetSockAddr(const Ip6::SockAddr &aSockAddr) { mSockAddr = aSockAddr; }
-
-        /**
-         * Indicates whether the peer matches a given Extended Address.
-         *
-         * @param[in] aExtAddress   A Extended Address to match with.
-         *
-         * @retval TRUE if the peer matches @p aExtAddress.
-         * @retval FALSE if the peer does not match @p aExtAddress.
-         */
-        bool Matches(const Mac::ExtAddress &aExtAddress) const { return GetExtAddress() == aExtAddress; }
-
-        /**
-         * Indicates whether the peer matches a given Socket Address.
-         *
-         * @param[in] aSockAddr   A Socket Address to match with.
-         *
-         * @retval TRUE if the peer matches @p aSockAddr.
-         * @retval FALSE if the peer does not match @p aSockAddr.
-         */
-        bool Matches(const Ip6::SockAddr &aSockAddr) const { return GetSockAddr() == aSockAddr; }
-
-    private:
-        class Info : public otPlatTrelPeerInfo
-        {
-        public:
-            bool                 IsRemoved(void) const { return mRemoved; }
-            const uint8_t       *GetTxtData(void) const { return mTxtData; }
-            uint16_t             GetTxtLength(void) const { return mTxtLength; }
-            const Ip6::SockAddr &GetSockAddr(void) const { return static_cast<const Ip6::SockAddr &>(mSockAddr); }
-        };
-
-        void SetExtAddress(const Mac::ExtAddress &aExtAddress) { mExtAddress = aExtAddress; }
-        void SetExtPanId(const MeshCoP::ExtendedPanId &aExtPanId) { mExtPanId = aExtPanId; }
-        void Log(const char *aAction) const;
-
-        Peer *mNext;
-    };
-
     /**
      * Represents an iterator for iterating over TREL peer table entries.
      */
@@ -288,6 +208,13 @@ class Interface : public InstanceLocator
     static const char kTxtRecordExtAddressKey[];
     static const char kTxtRecordExtPanIdKey[];
 
+    struct PeerInfo : public otPlatTrelPeerInfo
+    {
+        bool                 IsRemoved(void) const { return mRemoved; }
+        const Ip6::SockAddr &GetSockAddr(void) const { return AsCoreType(&mSockAddr); }
+        Error                ParseTxtData(Mac::ExtAddress &aExtAddress, MeshCoP::ExtendedPanId &aExtPanId) const;
+    };
+
     explicit Interface(Instance &aInstance);
 
     // Methods used by `Trel::Link`.
@@ -298,12 +225,9 @@ class Interface : public InstanceLocator
 
     // Callbacks from `otPlatTrel`.
     void HandleReceived(uint8_t *aBuffer, uint16_t aLength, const Ip6::SockAddr &aSenderAddr);
-    void HandleDiscoveredPeerInfo(const Peer::Info &aInfo);
+    void HandleDiscoveredPeerInfo(const PeerInfo &aInfo);
 
     void  RegisterService(void);
-    Error ParsePeerInfoTxtData(const Peer::Info       &aInfo,
-                               Mac::ExtAddress        &aExtAddress,
-                               MeshCoP::ExtendedPanId &aExtPanId) const;
     Peer *GetNewPeerEntry(void);
     void  RemovePeerEntry(Peer &aEntry);
     void  ClearPeerList(void);

src/core/radio/trel_link.hpp

@@ -165,8 +165,6 @@ class Link : public InstanceLocator
     static constexpr uint32_t kAckWaitWindow   = 750; // (in msec)
     static constexpr uint16_t kFcfFramePending = 1 << 4;
 
-    typedef Interface::Peer Peer;
-
     enum State : uint8_t
     {
         kStateDisabled,

src/core/radio/trel_peer.cpp

@@ -0,0 +1,76 @@
+/*
+ *    Copyright (c) 2025, The OpenThread Authors.
+ *    All rights reserved.
+ *
+ *    Redistribution and use in source and binary forms, with or without
+ *    modification, are permitted provided that the following conditions are met:
+ *    1. Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *    3. Neither the name of the copyright holder nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ *    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ *    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+ *    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ *    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ *    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ *   This file implements Thread Radio Encapsulation Link (TREL) peer.
+ */
+
+#include "trel_peer.hpp"
+
+#if OPENTHREAD_CONFIG_RADIO_LINK_TREL_ENABLE
+
+#include "instance/instance.hpp"
+
+namespace ot {
+namespace Trel {
+
+RegisterLogModule("TrelInterface");
+
+#if OT_SHOULD_LOG_AT(OT_LOG_LEVEL_INFO)
+
+void Peer::Log(Action aAction) const
+{
+    LogInfo("%s peer mac:%s, xpan:%s, %s", ActionToString(aAction), GetExtAddress().ToString().AsCString(),
+            GetExtPanId().ToString().AsCString(), GetSockAddr().ToString().AsCString());
+}
+
+const char *Peer::ActionToString(Action aAction)
+{
+    static const char *const kActionStrings[] = {
+        "Added",    // (0) kAdded
+        "Updated",  // (1) kUpdated
+        "Removing", // (2) kRemoving
+    };
+
+    struct EnumCheck
+    {
+        InitEnumValidatorCounter();
+        ValidateNextEnum(kAdded);
+        ValidateNextEnum(kUpdated);
+        ValidateNextEnum(kRemoving);
+    };
+
+    return kActionStrings[aAction];
+}
+
+#endif // OT_SHOULD_LOG_AT(OT_LOG_LEVEL_INFO)
+
+} // namespace Trel
+} // namespace ot
+
+#endif // #if OPENTHREAD_CONFIG_RADIO_LINK_TREL_ENABLE