[mdns] add validation for names in browser and resolver APIs (#12184)

This commit introduces validation for names provided to mDNS browser,
resolver, and querier start and stop functions.

New `ValidateNamesIn()` overloads are added to check the validity of
service types, instance names, and host names passed to APIs like
`otMdnsStartBrowser()`, `otMdnsStartSrvResolver()`, etc.

include/openthread/instance.h

@@ -52,7 +52,7 @@ extern "C" {
  *
  * @note This number versions both OpenThread platform and user APIs.
  */
-#define OPENTHREAD_API_VERSION (555)
+#define OPENTHREAD_API_VERSION (556)
 
 /**
  * @addtogroup api-instance

include/openthread/mdns.h

@@ -684,6 +684,7 @@ typedef otPlatDnssdRecordQuerier otMdnsRecordQuerier;
  * @retval OT_ERROR_NONE           Browser started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical browser (same service and callback) is already active.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aBrowser is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartBrowser(otInstance *aInstance, const otMdnsBrowser *aBrowser);
 
@@ -697,6 +698,7 @@ otError otMdnsStartBrowser(otInstance *aInstance, const otMdnsBrowser *aBrowser)
  *
  * @retval OT_ERROR_NONE           Browser stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aBrowser is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopBrowser(otInstance *aInstance, const otMdnsBrowser *aBroswer);
 
@@ -721,6 +723,7 @@ otError otMdnsStopBrowser(otInstance *aInstance, const otMdnsBrowser *aBroswer);
  * @retval OT_ERROR_NONE           Resolver started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical resolver (same service and callback) is already active.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartSrvResolver(otInstance *aInstance, const otMdnsSrvResolver *aResolver);
 
@@ -734,6 +737,7 @@ otError otMdnsStartSrvResolver(otInstance *aInstance, const otMdnsSrvResolver *a
  *
  * @retval OT_ERROR_NONE           Resolver stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopSrvResolver(otInstance *aInstance, const otMdnsSrvResolver *aResolver);
 
@@ -758,6 +762,7 @@ otError otMdnsStopSrvResolver(otInstance *aInstance, const otMdnsSrvResolver *aR
  * @retval OT_ERROR_NONE           Resolver started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical resolver (same service and callback) is already active.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartTxtResolver(otInstance *aInstance, const otMdnsTxtResolver *aResolver);
 
@@ -771,6 +776,7 @@ otError otMdnsStartTxtResolver(otInstance *aInstance, const otMdnsTxtResolver *a
  *
  * @retval OT_ERROR_NONE           Resolver stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopTxtResolver(otInstance *aInstance, const otMdnsTxtResolver *aResolver);
 
@@ -795,6 +801,7 @@ otError otMdnsStopTxtResolver(otInstance *aInstance, const otMdnsTxtResolver *aR
  * @retval OT_ERROR_NONE           Resolver started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical resolver (same host and callback) is already active.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartIp6AddressResolver(otInstance *aInstance, const otMdnsAddressResolver *aResolver);
 
@@ -808,6 +815,7 @@ otError otMdnsStartIp6AddressResolver(otInstance *aInstance, const otMdnsAddress
  *
  * @retval OT_ERROR_NONE           Resolver stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopIp6AddressResolver(otInstance *aInstance, const otMdnsAddressResolver *aResolver);
 
@@ -833,6 +841,7 @@ otError otMdnsStopIp6AddressResolver(otInstance *aInstance, const otMdnsAddressR
  * @retval OT_ERROR_NONE           Resolver started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical resolver (same host and callback) is already active.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartIp4AddressResolver(otInstance *aInstance, const otMdnsAddressResolver *aResolver);
 
@@ -846,6 +855,7 @@ otError otMdnsStartIp4AddressResolver(otInstance *aInstance, const otMdnsAddress
  *
  * @retval OT_ERROR_NONE           Resolver stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   A name in @p aResolver is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopIp4AddressResolver(otInstance *aInstance, const otMdnsAddressResolver *aResolver);
 
@@ -886,7 +896,8 @@ otError otMdnsStopIp4AddressResolver(otInstance *aInstance, const otMdnsAddressR
  * @retval OT_ERROR_NONE           Record @p aQuerier started successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
  * @retval OT_ERROR_ALREADY        An identical querier (same name, record type, and callback) is already active.
- * @retval OT_ERROR_INVALID_ARGS   The `mRecordType` in @p aQuerier is invalid. MUST use browser/resolvers.
+ * @retval OT_ERROR_INVALID_ARGS   The `mRecordType` in @p aQuerier is invalid (MUST use browser/resolvers), or
+ *                                 a name in @p aQuerier is invalid, or the callback is `NULL`.
  */
 otError otMdnsStartRecordQuerier(otInstance *aInstance, const otMdnsRecordQuerier *aQuerier);
 
@@ -903,6 +914,8 @@ otError otMdnsStartRecordQuerier(otInstance *aInstance, const otMdnsRecordQuerie
  *
  * @retval OT_ERROR_NONE           Querier stopped successfully.
  * @retval OT_ERROR_INVALID_STATE  mDNS module is not enabled.
+ * @retval OT_ERROR_INVALID_ARGS   The `mRecordType` in @p aQuerier is invalid (MUST use browser/resolvers), or
+ *                                 a name in @p aQuerier is invalid, or the callback is `NULL`.
  */
 otError otMdnsStopRecordQuerier(otInstance *aInstance, const otMdnsRecordQuerier *aQuerier);
 

src/core/net/mdns.cpp

@@ -5147,6 +5147,7 @@ Error Core::Start(const BrowserResolverType &aBrowserOrResolver)
 
     VerifyOrExit(mIsEnabled, error = kErrorInvalidState);
     VerifyOrExit(aBrowserOrResolver.mCallback != nullptr, error = kErrorInvalidArgs);
+    SuccessOrExit(error = ValidateNamesIn(aBrowserOrResolver));
 
     cacheEntry = GetCacheList<CacheType>().FindMatching(aBrowserOrResolver);
 
@@ -5172,6 +5173,7 @@ Error Core::Stop(const BrowserResolverType &aBrowserOrResolver)
 
     VerifyOrExit(mIsEnabled, error = kErrorInvalidState);
     VerifyOrExit(aBrowserOrResolver.mCallback != nullptr, error = kErrorInvalidArgs);
+    SuccessOrExit(error = ValidateNamesIn(aBrowserOrResolver));
 
     cacheEntry = GetCacheList<CacheType>().FindMatching(aBrowserOrResolver);
     VerifyOrExit(cacheEntry != nullptr);
@@ -5221,6 +5223,8 @@ Error Core::StartRecordQuerier(const RecordQuerier &aQuerier)
     return error;
 }
 
+Error Core::StopRecordQuerier(const RecordQuerier &aQuerier) { return Stop<RecordCache, RecordQuerier>(aQuerier); }
+
 Error Core::StopIp6AddressResolver(const AddressResolver &aResolver)
 {
     return Stop<Ip6AddrCache, AddressResolver>(aResolver);
@@ -5236,7 +5240,62 @@ Error Core::StopIp4AddressResolver(const AddressResolver &aResolver)
     return Stop<Ip4AddrCache, AddressResolver>(aResolver);
 }
 
-Error Core::StopRecordQuerier(const RecordQuerier &aQuerier) { return Stop<RecordCache, RecordQuerier>(aQuerier); }
+Error Core::ValidateNamesIn(const Browser &aBrowser) const
+{
+    Error error;
+
+    SuccessOrExit(error = Name::ValidateName(aBrowser.mServiceType));
+
+    if (aBrowser.mSubTypeLabel != nullptr)
+    {
+        error = Name::ValidateLabel(aBrowser.mSubTypeLabel);
+    }
+
+exit:
+    return error;
+}
+
+Error Core::ValidateNamesIn(const SrvResolver &aSrvResolver) const
+{
+    Error error;
+
+    SuccessOrExit(error = Name::ValidateLabel(aSrvResolver.mServiceInstance));
+    error = Name::ValidateName(aSrvResolver.mServiceType);
+
+exit:
+    return error;
+}
+
+Error Core::ValidateNamesIn(const TxtResolver &aTxtResolver) const
+{
+    Error error;
+
+    SuccessOrExit(error = Name::ValidateLabel(aTxtResolver.mServiceInstance));
+    error = Name::ValidateName(aTxtResolver.mServiceType);
+
+exit:
+    return error;
+}
+
+Error Core::ValidateNamesIn(const AddressResolver &aAddressResolver) const
+{
+    return Name::ValidateName(aAddressResolver.mHostName);
+}
+
+Error Core::ValidateNamesIn(const RecordQuerier &aRecordQuerier) const
+{
+    Error error;
+
+    SuccessOrExit(error = Name::ValidateLabel(aRecordQuerier.mFirstLabel));
+
+    if (aRecordQuerier.mNextLabels != nullptr)
+    {
+        error = Name::ValidateName(aRecordQuerier.mNextLabels);
+    }
+
+exit:
+    return error;
+}
 
 void Core::AddPassiveSrvTxtCache(const char *aServiceInstance, const char *aServiceType)
 {

src/core/net/mdns.hpp

@@ -472,6 +472,7 @@ public:
      * @retval kErrorNone           Browser started successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
      * @retval kErrorAlready        An identical browser (same service and callback) is already active.
+     * @retval kErrorInvalidArgs    A name in @p aBrowser is invalid, or the callback is `nullptr`.
      */
     Error StartBrowser(const Browser &aBrowser);
 
@@ -483,7 +484,8 @@ public:
      * @param[in] aBrowser    The browser to stop.
      *
      * @retval kErrorNone           Browser stopped successfully.
-     * @retval kErrorInvalidSatet  mDNS module is not enabled.
+     * @retval kErrorInvalidState   mDNS module is not enabled.
+     * @retval kErrorInvalidArgs    A name in @p aBrowser is invalid, or the callback is `nullptr`.
      */
     Error StopBrowser(const Browser &aBrowser);
 
@@ -507,6 +509,7 @@ public:
      * @retval kErrorNone           Resolver started successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
      * @retval kErrorAlready        An identical resolver (same service and callback) is already active.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StartSrvResolver(const SrvResolver &aResolver);
 
@@ -519,6 +522,7 @@ public:
      *
      * @retval kErrorNone           Resolver stopped successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StopSrvResolver(const SrvResolver &aResolver);
 
@@ -542,6 +546,7 @@ public:
      * @retval kErrorNone           Resolver started successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
      * @retval kErrorAlready        An identical resolver (same service and callback) is already active.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StartTxtResolver(const TxtResolver &aResolver);
 
@@ -554,6 +559,7 @@ public:
      *
      * @retval kErrorNone           Resolver stopped successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StopTxtResolver(const TxtResolver &aResolver);
 
@@ -577,6 +583,7 @@ public:
      * @retval kErrorNone           Resolver started successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
      * @retval kErrorAlready        An identical resolver (same host and callback) is already active.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StartIp6AddressResolver(const AddressResolver &aResolver);
 
@@ -589,6 +596,7 @@ public:
      *
      * @retval kErrorNone           Resolver stopped successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StopIp6AddressResolver(const AddressResolver &aResolver);
 
@@ -613,6 +621,7 @@ public:
      * @retval kErrorNone           Resolver started successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
      * @retval kErrorAlready        An identical resolver (same host and callback) is already active.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StartIp4AddressResolver(const AddressResolver &aResolver);
 
@@ -625,6 +634,7 @@ public:
      *
      * @retval kErrorNone           Resolver stopped successfully.
      * @retval kErrorInvalidState   mDNS module is not enabled.
+     * @retval kErrorInvalidArgs    A name in @p aResolver is invalid, or the callback is `nullptr`.
      */
     Error StopIp4AddressResolver(const AddressResolver &aResolver);
 
@@ -653,10 +663,11 @@ public:
      *
      * @param[in] aQuerier    The record querier to be started.
      *
-     * @retval kErrorNone              Record @p aQuerier started successfully.
-     * @retval kErrorInvalidState      mDNS module is not enabled.
-     * @retval kErrorAlready           An identical querier (same name, record type, and callback) is already active.
-     * @retval kErrorInvalidArg   The `mRecordType` in @p aQuerier is invalid. MUST use browser/resolvers.
+     * @retval kErrorNone          Record @p aQuerier started successfully.
+     * @retval kErrorInvalidState  mDNS module is not enabled.
+     * @retval kErrorAlready       An identical querier (same name, record type, and callback) is already active.
+     * @retval kErrorInvalidArgs   The `mRecordType` in @p aQuerier is invalid (MUST use browser/resolvers), or
+     *                             a name in @p aQuerier is invalid, or the callback is `nullptr`.
      */
     Error StartRecordQuerier(const RecordQuerier &aQuerier);
 
@@ -667,8 +678,10 @@ public:
      *
      * @param[in] aQuerier    The record querier to be stopped.
      *
-     * @retval kErrorNone           Querier stopped successfully.
-     * @retval kErrorInvalidStat    mDNS module is not enabled.
+     * @retval kErrorNone          Querier stopped successfully.
+     * @retval kErrorInvalidState  mDNS module is not enabled.
+     * @retval kErrorInvalidArgs   The `mRecordType` in @p aQuerier is invalid (MUST use browser/resolvers), or
+     *                             a name in @p aQuerier is invalid, or the callback is `nullptr`.
      */
     Error StopRecordQuerier(const RecordQuerier &aQuerier);
 
@@ -2328,6 +2341,11 @@ private:
     Error     ValidateHostName(const Host &aHost) const;
     Error     ValidateServiceNames(const Service &aService, bool aCheckHostAndSubTypeLabels) const;
     Error     ValidateKeyName(const Key &aKey) const;
+    Error     ValidateNamesIn(const Browser &aBrowser) const;
+    Error     ValidateNamesIn(const SrvResolver &aSrvResolver) const;
+    Error     ValidateNamesIn(const TxtResolver &aTxtResolver) const;
+    Error     ValidateNamesIn(const AddressResolver &aAddressResolver) const;
+    Error     ValidateNamesIn(const RecordQuerier &aRecordQuerier) const;
     void      HandleInfraIfStateChanged(void);
     void      HandleHostAddressEvent(const Ip6::Address &aAddress, bool aAdded, uint32_t aInfraIfIndex);
     void      HandleHostAddressRemoveAll(uint32_t aInfraIfIndex);