[border-agent] use ephemeral port (#6450)

This commit changes border agent service to use ephemeral port by
default. This change makes it easier to support multiple Thread
interfaces on a single host.

include/openthread/border_agent.h

@@ -65,13 +65,23 @@ typedef enum otBorderAgentState
 /**
  * This function gets the state of Thread Border Agent role.
  *
- * @param[in]  aInstance         A pointer to an OpenThread instance.
+ * @param[in]  aInstance  A pointer to an OpenThread instance.
  *
  * @returns State of the Border Agent.
  *
  */
 otBorderAgentState otBorderAgentGetState(otInstance *aInstance);
 
+/**
+ * This function gets the UDP port of Thread Border Agent service.
+ *
+ * @param[in]  aInstance  A pointer to an OpenThread instance.
+ *
+ * @returns UDP port of the Border Agent.
+ *
+ */
+uint16_t otBorderAgentGetUdpPort(otInstance *aInstance);
+
 /**
  * @}
  *

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (102)
+#define OPENTHREAD_API_VERSION (103)
 
 /**
  * @addtogroup api-instance

src/cli/README.md

@@ -21,6 +21,7 @@ Done
 
 ## OpenThread Command List
 
+- [ba](#ba-port)
 - [bbr](#bbr)
 - [br](#br)
 - [bufferinfo](#bufferinfo)
@@ -316,6 +317,16 @@ Set jitter (in seconds) for Backbone Router registration for Thread 1.2 FTD.
 Done
 ```
 
+### ba port
+
+Print border agent service port.
+
+```bash
+> ba port
+49152
+Done
+```
+
 ### br
 
 Enbale/disable the Border Routing functionality.

src/cli/cli.cpp

@@ -285,6 +285,20 @@ otError Interpreter::ProcessHelp(uint8_t aArgsLength, char *aArgs[])
     return OT_ERROR_NONE;
 }
 
+#if OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE
+otError Interpreter::ProcessBorderAgent(uint8_t aArgsLength, char *aArgs[])
+{
+    otError error = OT_ERROR_NONE;
+
+    VerifyOrExit(aArgsLength == 1 && strcmp(aArgs[0], "port") == 0, error = OT_ERROR_INVALID_COMMAND);
+
+    OutputLine("%hu", otBorderAgentGetUdpPort(mInstance));
+
+exit:
+    return error;
+}
+#endif
+
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 otError Interpreter::ProcessBorderRouting(uint8_t aArgsLength, char *aArgs[])
 {

src/cli/cli.hpp

@@ -332,6 +332,9 @@ private:
     otError ProcessCcaThreshold(uint8_t aArgsLength, char *aArgs[]);
     otError ProcessBufferInfo(uint8_t aArgsLength, char *aArgs[]);
     otError ProcessChannel(uint8_t aArgsLength, char *aArgs[]);
+#if OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE
+    otError ProcessBorderAgent(uint8_t aArgsLength, char *aArgs[]);
+#endif
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     otError ProcessBorderRouting(uint8_t aArgsLength, char *aArgs[]);
 #endif
@@ -638,6 +641,9 @@ private:
     void HandleDiscoveryRequest(const otThreadDiscoveryRequestInfo &aInfo);
 
     static constexpr Command sCommands[] = {
+#if OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE
+        {"ba", &Interpreter::ProcessBorderAgent},
+#endif
 #if (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
         {"bbr", &Interpreter::ProcessBackboneRouter},
 #endif

src/core/api/border_agent_api.cpp

@@ -49,4 +49,11 @@ otBorderAgentState otBorderAgentGetState(otInstance *aInstance)
     return static_cast<otBorderAgentState>(instance.Get<MeshCoP::BorderAgent>().GetState());
 }
 
+uint16_t otBorderAgentGetUdpPort(otInstance *aInstance)
+{
+    Instance &instance = *static_cast<Instance *>(aInstance);
+
+    return instance.Get<MeshCoP::BorderAgent>().GetUdpPort();
+}
+
 #endif // OPENTHREAD_CONFIG_BORDER_AGENT_ENABLE

src/core/coap/coap_secure.hpp

@@ -155,6 +155,14 @@ public:
      */
     MeshCoP::Dtls &GetDtls(void) { return mDtls; }
 
+    /**
+     * This method gets the UDP port of this agent.
+     *
+     * @returns  UDP port number.
+     *
+     */
+    uint16_t GetUdpPort(void) const { return mDtls.GetUdpPort(); }
+
     /**
      * This method sets the PSK.
      *

src/core/config/border_router.h

@@ -65,4 +65,14 @@
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE 0
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_BORDER_AGENT_UDP_PORT
+ *
+ * Specifies the Border Agent UDP port, and use 0 for ephemeral port.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_BORDER_AGENT_UDP_PORT
+#define OPENTHREAD_CONFIG_BORDER_AGENT_UDP_PORT 0
+#endif
+
 #endif // CONFIG_BORDER_ROUTER_H_

src/core/config/srp_server.h

@@ -48,7 +48,7 @@
 /**
  * @def OPENTHREAD_CONFIG_SRP_SERVER_UDP_PORT
  *
- * Specifies the SRP Server UDP port.
+ * Specifies the SRP Server UDP port, and use 0 for ephemeral port.
  *
  */
 #ifndef OPENTHREAD_CONFIG_SRP_SERVER_UDP_PORT

src/core/meshcop/border_agent.cpp

@@ -48,6 +48,10 @@
 namespace ot {
 namespace MeshCoP {
 
+namespace {
+constexpr uint16_t kBorderAgentUdpPort = OPENTHREAD_CONFIG_BORDER_AGENT_UDP_PORT; ///< UDP port of border agent service.
+}
+
 void BorderAgent::ForwardContext::Init(Instance &           aInstance,
                                        const Coap::Message &aMessage,
                                        bool                 aPetition,
@@ -570,6 +574,11 @@ void BorderAgent::HandleConnected(bool aConnected)
     }
 }
 
+uint16_t BorderAgent::GetUdpPort(void) const
+{
+    return Get<Coap::CoapSecure>().GetUdpPort();
+}
+
 Error BorderAgent::Start(void)
 {
     Error             error;

src/core/meshcop/border_agent.hpp

@@ -74,6 +74,14 @@ public:
      */
     explicit BorderAgent(Instance &aInstance);
 
+    /**
+     * This method gets the UDP port of this service.
+     *
+     * @returns  UDP port number.
+     *
+     */
+    uint16_t GetUdpPort(void) const;
+
     /**
      * This method starts the Border Agent service.
      *

src/core/meshcop/dtls.cpp

@@ -208,6 +208,11 @@ exit:
     return;
 }
 
+uint16_t Dtls::GetUdpPort(void) const
+{
+    return mSocket.GetSockName().GetPort();
+}
+
 Error Dtls::Bind(uint16_t aPort)
 {
     Error error;

src/core/meshcop/dtls.hpp

@@ -135,6 +135,14 @@ public:
      */
     Error Bind(uint16_t aPort);
 
+    /**
+     * This method gets the UDP port of this session.
+     *
+     * @returns  UDP port number.
+     *
+     */
+    uint16_t GetUdpPort(void) const;
+
     /**
      * This method binds this DTLS with a transport callback.
      *

src/core/meshcop/meshcop.hpp

@@ -59,7 +59,7 @@ namespace MeshCoP {
 
 enum
 {
-    kBorderAgentUdpPort = 49191, ///< UDP port of border agent service.
+    kNativeCommissionerUdpPort = 49191, ///< UDP port of native commissioner service.
 };
 
 /**

src/core/net/ip6_filter.cpp

@@ -88,7 +88,7 @@ bool Filter::Accept(Message &aMessage) const
         }
 
         // Allow native commissioner traffic
-        if (mAllowNativeCommissioner && dstport == MeshCoP::kBorderAgentUdpPort)
+        if (mAllowNativeCommissioner && dstport == MeshCoP::kNativeCommissionerUdpPort)
         {
             ExitNow(rval = true);
         }

src/core/thread/mle_router.cpp

@@ -2909,7 +2909,8 @@ Error MleRouter::SendDiscoveryResponse(const Ip6::Address &aDestination, const M
 
     if (Get<KeyManager>().GetSecurityPolicy().mNativeCommissioningEnabled)
     {
-        SuccessOrExit(error = Tlv::Append<MeshCoP::CommissionerUdpPortTlv>(*message, MeshCoP::kBorderAgentUdpPort));
+        SuccessOrExit(error =
+                          Tlv::Append<MeshCoP::CommissionerUdpPortTlv>(*message, MeshCoP::kNativeCommissionerUdpPort));
 
         discoveryResponse.SetNativeCommissioner(true);
     }

tests/scripts/expect/cli-misc.exp

@@ -167,4 +167,7 @@ expect_line "Done"
 send "diag start\n"
 expect ": InvalidState"
 
+send "ba port\n"
+expect "Done"
+
 dispose_all

tests/scripts/thread-cert/border_router/test_dnssd_server.py

@@ -232,13 +232,16 @@ class TestDnssdServerOnBr(thread_cert.TestCase):
         dp_instance_name = f'{network_name}._meshcop._udp.default.service.arpa.'
         dp_hostname = lambda x: x.endswith('.default.service.arpa.')
 
+        def check_border_agent_port(port):
+            return 0 < port <= 65535
+
         dig_result = self.nodes[DIGGER].dns_dig(server_addr, dp_service_name, 'PTR')
         self._assert_dig_result_matches(
             dig_result, {
                 'QUESTION': [(dp_service_name, 'IN', 'PTR'),],
                 'ANSWER': [(dp_service_name, 'IN', 'PTR', dp_instance_name),],
                 'ADDITIONAL': [
-                    (dp_instance_name, 'IN', 'SRV', 0, 0, config.BORDER_AGENT_UDP_PORT, dp_hostname),
+                    (dp_instance_name, 'IN', 'SRV', 0, 0, check_border_agent_port, dp_hostname),
                     (dp_instance_name, 'IN', 'TXT', lambda txt: (isinstance(txt, dict) and txt.get(
                         'nn') == network_name and 'xp' in txt and 'tv' in txt and 'dd' in txt)),
                 ],
@@ -258,7 +261,7 @@ class TestDnssdServerOnBr(thread_cert.TestCase):
         self._assert_dig_result_matches(
             dig_result, {
                 'QUESTION': [(dp_instance_name, 'IN', 'SRV'),],
-                'ANSWER': [(dp_instance_name, 'IN', 'SRV', 0, 0, config.BORDER_AGENT_UDP_PORT, dp_hostname),],
+                'ANSWER': [(dp_instance_name, 'IN', 'SRV', 0, 0, check_border_agent_port, dp_hostname),],
                 'ADDITIONAL': [(dp_instance_name, 'IN', 'TXT', lambda txt: (isinstance(txt, dict) and txt.get(
                     'nn') == network_name and 'xp' in txt and 'tv' in txt and 'dd' in txt)),],
             })
@@ -269,7 +272,7 @@ class TestDnssdServerOnBr(thread_cert.TestCase):
                 'QUESTION': [(dp_instance_name, 'IN', 'TXT'),],
                 'ANSWER': [(dp_instance_name, 'IN', 'TXT', lambda txt: (isinstance(txt, dict) and txt.get(
                     'nn') == network_name and 'xp' in txt and 'tv' in txt and 'dd' in txt)),],
-                'ADDITIONAL': [(dp_instance_name, 'IN', 'SRV', 0, 0, config.BORDER_AGENT_UDP_PORT, dp_hostname),],
+                'ADDITIONAL': [(dp_instance_name, 'IN', 'SRV', 0, 0, check_border_agent_port, dp_hostname),],
             })
 
         if dp_ip6_address is not None:

tests/scripts/thread-cert/config.py

@@ -144,8 +144,6 @@ LEADER_NOTIFY_SED_BY_CHILD_UPDATE_REQUEST = True
 THREAD_VERSION_1_1 = 2
 THREAD_VERSION_1_2 = 3
 
-BORDER_AGENT_UDP_PORT = 49191
-
 
 def create_default_network_data_prefix_sub_tlvs_factories():
     return {