[border-agent] add support for vo key in TXT data parser (#12858)

This commit adds support for the Vendor OUI (`vo`) key in the Border
Agent MeshCoP service TXT data parser.

The `otBorderAgentTxtDataInfo` structure and its internal counterpart
`TxtData::Info` are updated to include a boolean flag `mHasVendorOui`
and a 3-byte array `mVendorOui` to store the 24-bit vendor OUI.

The parsing logic in `TxtData::Info::ProcessTxtEntry()` is updated to
recognize the `vo` key and extract its value. Additionally, the CLI
`Interpreter` is updated to output the vendor OUI in hexadecimal
format when it is present in the parsed information.

include/openthread/border_agent_txt_data.h

@@ -61,6 +61,7 @@ extern "C" {
 #define OT_BORDER_AGENT_THREAD_VERSION_SIZE (16) ///< Max size of Thread Version string in `otBorderAgentTxtDataInfo`.
 #define OT_BORDER_AGENT_VENDOR_NAME_SIZE (32)    ///< Max size of Vendor Name string in `otBorderAgentTxtDataInfo`.
 #define OT_BORDER_AGENT_MODEL_NAME_SIZE (32)     ///< Max size of Model Name string in `otBorderAgentTxtDataInfo`.
+#define OT_BORDER_AGENT_VENDOR_OUI_SIZE (3)      ///< Size of Vendor OUI (in bytes) in `otBorderAgentTxtDataInfo`.
 
 /**
  * Represents the Connection Mode in a Border Agent State Bitmap.
@@ -152,6 +153,7 @@ typedef struct otBorderAgentTxtDataInfo
     bool                     mHasExtAddress : 1;      ///< Indicates whether Extended Address is present.
     bool                     mHasVendorName : 1;      ///< Indicates whether Vendor Name is present.
     bool                     mHasModelName : 1;       ///< Indicates whether Model Name is present.
+    bool                     mHasVendorOui : 1;       ///< Indicates whether Vendor OUI is present.
     char                     mRecordVersion[OT_BORDER_AGENT_RECORD_VERSION_SIZE]; ///< Record Version string.
     otBorderAgentId          mAgentId;                                            ///< Agent ID.
     char                     mThreadVersion[OT_BORDER_AGENT_THREAD_VERSION_SIZE]; ///< Thread Version string.
@@ -167,6 +169,7 @@ typedef struct otBorderAgentTxtDataInfo
     otExtAddress             mExtAddress;                                         ///< Extended Address.
     char                     mVendorName[OT_BORDER_AGENT_VENDOR_NAME_SIZE];       ///< Vendor Name string.
     char                     mModelName[OT_BORDER_AGENT_MODEL_NAME_SIZE];         ///< Model Name string.
+    uint8_t                  mVendorOui[OT_BORDER_AGENT_VENDOR_OUI_SIZE];         ///< Vendor OUI (24-bit).
 } otBorderAgentTxtDataInfo;
 
 /**

include/openthread/instance.h

@@ -52,7 +52,7 @@ extern "C" {
  *
  * @note This number versions both OpenThread platform and user APIs.
  */
-#define OPENTHREAD_API_VERSION (589)
+#define OPENTHREAD_API_VERSION (590)
 
 /**
  * @addtogroup api-instance

src/cli/cli.cpp

@@ -740,6 +740,12 @@ void Interpreter::OutputBorderAgentTxtDataInfo(uint8_t aIndentSize, const otBord
         OutputLine(aIndentSize, "ModelName: %s", aInfo.mModelName);
     }
 
+    if (aInfo.mHasVendorOui)
+    {
+        OutputLine(aIndentSize, "VendorOui: %02X-%02X-%02X", aInfo.mVendorOui[0], aInfo.mVendorOui[1],
+                   aInfo.mVendorOui[2]);
+    }
+
     if (aInfo.mHasStateBitmap)
     {
         uint8_t indent = aIndentSize + kIndentSize;

src/core/meshcop/border_agent_txt_data.cpp

@@ -59,6 +59,7 @@ const char TxtData::Key::kOmrPrefix[]       = "omr";
 const char TxtData::Key::kExtAddress[]      = "xa";
 const char TxtData::Key::kVendorName[]      = "vn";
 const char TxtData::Key::kModelName[]       = "mn";
+const char TxtData::Key::kVendorOui[]       = "vo";
 
 TxtData::TxtData(Instance &aInstance)
     : InstanceLocator(aInstance)
@@ -478,6 +479,10 @@ void TxtData::Info::ProcessTxtEntry(const Dns::TxtEntry &aEntry)
         ReadStringValue(aEntry, mModelName);
         mHasModelName = true;
     }
+    else if (aEntry.MatchesKey(Key::kVendorOui))
+    {
+        mHasVendorOui = ReadValue(aEntry, mVendorOui);
+    }
 }
 
 bool TxtData::Info::ReadValue(const Dns::TxtEntry &aEntry, void *aBuffer, uint16_t aSize)

src/core/meshcop/border_agent_txt_data.hpp

@@ -300,6 +300,7 @@ private:
         static const char kExtAddress[];
         static const char kVendorName[];
         static const char kModelName[];
+        static const char kVendorOui[];
     };
 
     struct StateBitmap