[rest] return border agent ID (#1864)

* [rest] return node information when detached

Ignore error return of otThreadGetLeaderData(). It only returns an error
when the Thread border router is detached, which we don't want to
consider as an error condition. Instead, make sure the NodeInfo struct
is cleared. This makes sure that we don't leak stack data.

* [rest] return border agent ID

Add BaId to the node JSON object and add a dedicated endpoint
/node/ba-id to retrive the border agent ID.

src/rest/json.cpp

@@ -346,6 +346,7 @@ std::string Node2JsonString(const NodeInfo &aNode)
     cJSON      *node = cJSON_CreateObject();
     std::string ret;
 
+    cJSON_AddItemToObject(node, "BaId", Bytes2HexJson(aNode.mBaId, OT_BORDER_AGENT_ID_LENGTH));
     cJSON_AddItemToObject(node, "State", cJSON_CreateNumber(aNode.mRole));
     cJSON_AddItemToObject(node, "NumOfRouter", cJSON_CreateNumber(aNode.mNumOfRouter));
     cJSON_AddItemToObject(node, "RlocAddress", IpAddr2Json(aNode.mRlocAddress));

src/rest/openapi.yaml

@@ -43,6 +43,20 @@ paths:
             application/json:
               schema:
                 type: object
+  /node/ba-id:
+    get:
+      tags:
+        - node
+      summary: Get the border agent ID
+      responses:
+        "200":
+          description: Successful operation
+          content:
+            application/json:
+              schema:
+                type: string
+                description: 16 byte border agent ID as hex string.
+                example: "AA897CA8A67F6E6DD6166133AD1562A5"
   /node/rloc:
     get:
       tags:

src/rest/resource.cpp

@@ -37,6 +37,7 @@
 
 #define OT_REST_RESOURCE_PATH_DIAGNOSTICS "/diagnostics"
 #define OT_REST_RESOURCE_PATH_NODE "/node"
+#define OT_REST_RESOURCE_PATH_NODE_BAID "/node/ba-id"
 #define OT_REST_RESOURCE_PATH_NODE_RLOC "/node/rloc"
 #define OT_REST_RESOURCE_PATH_NODE_RLOC16 "/node/rloc16"
 #define OT_REST_RESOURCE_PATH_NODE_EXTADDRESS "/node/ext-address"
@@ -129,6 +130,7 @@ Resource::Resource(ControllerOpenThread *aNcp)
     // Resource Handler
     mResourceMap.emplace(OT_REST_RESOURCE_PATH_DIAGNOSTICS, &Resource::Diagnostic);
     mResourceMap.emplace(OT_REST_RESOURCE_PATH_NODE, &Resource::NodeInfo);
+    mResourceMap.emplace(OT_REST_RESOURCE_PATH_NODE_BAID, &Resource::BaId);
     mResourceMap.emplace(OT_REST_RESOURCE_PATH_NODE_STATE, &Resource::State);
     mResourceMap.emplace(OT_REST_RESOURCE_PATH_NODE_EXTADDRESS, &Resource::ExtendedAddr);
     mResourceMap.emplace(OT_REST_RESOURCE_PATH_NODE_NETWORKNAME, &Resource::NetworkName);
@@ -215,13 +217,15 @@ void Resource::ErrorHandler(Response &aResponse, HttpStatusCode aErrorCode) cons
 void Resource::GetNodeInfo(Response &aResponse) const
 {
     otbrError       error = OTBR_ERROR_NONE;
-    struct NodeInfo node;
+    struct NodeInfo node  = {};
     otRouterInfo    routerInfo;
     uint8_t         maxRouterId;
     std::string     body;
     std::string     errorCode;
+    uint16_t        idLength = OT_BORDER_AGENT_ID_LENGTH;
 
-    VerifyOrExit(otThreadGetLeaderData(mInstance, &node.mLeaderData) == OT_ERROR_NONE, error = OTBR_ERROR_REST);
+    VerifyOrExit(otBorderAgentGetId(mInstance, node.mBaId, &idLength) == OT_ERROR_NONE, error = OTBR_ERROR_REST);
+    (void)otThreadGetLeaderData(mInstance, &node.mLeaderData);
 
     node.mNumOfRouter = 0;
     maxRouterId       = otThreadGetMaxRouterId(mInstance);
@@ -269,6 +273,45 @@ void Resource::NodeInfo(const Request &aRequest, Response &aResponse) const
     }
 }
 
+void Resource::GetDataBaId(Response &aResponse) const
+{
+    otbrError   error = OTBR_ERROR_NONE;
+    uint8_t     id[OT_BORDER_AGENT_ID_LENGTH];
+    uint16_t    idLength = OT_BORDER_AGENT_ID_LENGTH;
+    std::string body;
+    std::string errorCode;
+
+    VerifyOrExit(otBorderAgentGetId(mInstance, id, &idLength) == OT_ERROR_NONE, error = OTBR_ERROR_REST);
+
+    body = Json::Bytes2HexJsonString(id, idLength);
+    aResponse.SetBody(body);
+
+exit:
+    if (error == OTBR_ERROR_NONE)
+    {
+        errorCode = GetHttpStatus(HttpStatusCode::kStatusOk);
+        aResponse.SetResponsCode(errorCode);
+    }
+    else
+    {
+        ErrorHandler(aResponse, HttpStatusCode::kStatusInternalServerError);
+    }
+}
+
+void Resource::BaId(const Request &aRequest, Response &aResponse) const
+{
+    std::string errorCode;
+
+    if (aRequest.GetMethod() == HttpMethod::kGet)
+    {
+        GetDataBaId(aResponse);
+    }
+    else
+    {
+        ErrorHandler(aResponse, HttpStatusCode::kStatusMethodNotAllowed);
+    }
+}
+
 void Resource::GetDataExtendedAddr(Response &aResponse) const
 {
     const uint8_t *extAddress = reinterpret_cast<const uint8_t *>(otLinkGetExtendedAddress(mInstance));

src/rest/resource.hpp

@@ -36,6 +36,7 @@
 
 #include <unordered_map>
 
+#include <openthread/border_agent.h>
 #include <openthread/border_router.h>
 
 #include "ncp/ncp_openthread.hpp"
@@ -117,6 +118,7 @@ class Resource
     typedef void (Resource::*ResourceHandler)(const Request &aRequest, Response &aResponse) const;
     typedef void (Resource::*ResourceCallbackHandler)(const Request &aRequest, Response &aResponse);
     void NodeInfo(const Request &aRequest, Response &aResponse) const;
+    void BaId(const Request &aRequest, Response &aResponse) const;
     void ExtendedAddr(const Request &aRequest, Response &aResponse) const;
     void State(const Request &aRequest, Response &aResponse) const;
     void NetworkName(const Request &aRequest, Response &aResponse) const;
@@ -132,6 +134,7 @@ class Resource
     void HandleDiagnosticCallback(const Request &aRequest, Response &aResponse);
 
     void GetNodeInfo(Response &aResponse) const;
+    void GetDataBaId(Response &aResponse) const;
     void GetDataExtendedAddr(Response &aResponse) const;
     void GetDataState(Response &aResponse) const;
     void GetDataNetworkName(Response &aResponse) const;

src/rest/types.hpp

@@ -38,6 +38,8 @@
 #include <string>
 #include <vector>
 
+#include <openthread/border_agent.h>
+
 #include "openthread/netdiag.h"
 
 #define OT_REST_ACCEPT_HEADER "Accept"
@@ -96,6 +98,7 @@ enum class ConnectionState : std::uint8_t
 };
 struct NodeInfo
 {
+    uint8_t        mBaId[OT_BORDER_AGENT_ID_LENGTH];
     uint32_t       mRole;
     uint32_t       mNumOfRouter;
     uint16_t       mRloc16;