Throw exception if parameter has wrong type in RPC method.

Formally, depending on the method implementation, this kind of error
is just ignored and parameter is skipped. Now aria2 responds error for
these cases. The required parameter checking is also reworked along
with this change.

src/RpcMethodImpl.cc

@@ -179,33 +179,24 @@ findRequestGroup(const SharedHandle<RequestGroupMan>& rgman, a2_gid_t gid)
 } // namespace
 
 namespace {
-void getPosParam(const RpcRequest& req, size_t posParamIndex,
-                 bool& posGiven, size_t& pos)
+bool checkPosParam(const Integer* posParam)
 {
-  const Integer* p = req.getIntegerParam(posParamIndex);
-  if(p) {
-    if(p->i() >= 0) {
-      pos = p->i();
-      posGiven = true;
-      return;
+  if(posParam) {
+    if(posParam->i() >= 0) {
+      return true;
     } else {
       throw DL_ABORT_EX("Position must be greater than or equal to 0.");
     }
   }
-  posGiven = false;
-} 
+  return false;
+}
 } // namespace
 
 namespace {
-a2_gid_t getRequiredGidParam
-(const RpcRequest& req, size_t posParamIndex)
+a2_gid_t str2Gid(const String* str)
 {
-  const String* gidParam = req.getStringParam(posParamIndex);
-  if(gidParam) {
-    return util::parseLLInt(gidParam->s());
-  } else {
-    throw DL_ABORT_EX(MSG_GID_NOT_PROVIDED);
-  }
+  assert(str);
+  return util::parseLLInt(str->s());
 }
 } // namespace
 
@@ -228,18 +219,21 @@ void extractUris(OutputIterator out, const List* src)
 SharedHandle<ValueBase> AddUriRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
+  const List* urisParam = checkRequiredParam<List>(req, 0);
+  const Dict* optsParam = checkParam<Dict>(req, 1);
+  const Integer* posParam = checkParam<Integer>(req, 2);
+
   std::vector<std::string> uris;
-  extractUris(std::back_inserter(uris), req.getListParam(0));
+  extractUris(std::back_inserter(uris), urisParam);
   if(uris.empty()) {
     throw DL_ABORT_EX("URI is not provided.");
   }
 
   SharedHandle<Option> requestOption(new Option(*e->getOption()));
-  gatherRequestOption(requestOption, req.getDictParam(1));
+  gatherRequestOption(requestOption, optsParam);
 
-  size_t pos = 0;
-  bool posGiven = false;
-  getPosParam(req, 2, posGiven, pos);
+  bool posGiven = checkPosParam(posParam);
+  size_t pos = posGiven ? posParam->i() : 0;
 
   std::vector<SharedHandle<RequestGroup> > result;
   createRequestGroupForUri(result, requestOption, uris,
@@ -269,24 +263,24 @@ std::string getHexSha1(const std::string& s)
 SharedHandle<ValueBase> AddTorrentRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  const String* torrentParam = req.getStringParam(0);
-  if(!torrentParam) {
-    throw DL_ABORT_EX("Torrent data is not provided.");
-  }
+  const String* torrentParam = checkRequiredParam<String>(req, 0);
+  const List* urisParam = checkParam<List>(req, 1);
+  const Dict* optsParam = checkParam<Dict>(req, 2);
+  const Integer* posParam = checkParam<Integer>(req, 3);
+
   SharedHandle<String> tempTorrentParam;
   if(req.jsonRpc) {
     tempTorrentParam = String::g(Base64::decode(torrentParam->s()));
     torrentParam = tempTorrentParam.get();
   }
   std::vector<std::string> uris;
-  extractUris(std::back_inserter(uris), req.getListParam(1));
+  extractUris(std::back_inserter(uris), urisParam);
 
   SharedHandle<Option> requestOption(new Option(*e->getOption()));
-  gatherRequestOption(requestOption, req.getDictParam(2));
+  gatherRequestOption(requestOption, optsParam);
 
-  size_t pos = 0;
-  bool posGiven = false;
-  getPosParam(req, 3, posGiven, pos);
+  bool posGiven = checkPosParam(posParam);
+  size_t pos = posGiven ? posParam->i() : 0;
 
   std::string filename = util::applyDir
     (requestOption->get(PREF_DIR), getHexSha1(torrentParam->s())+".torrent");
@@ -316,21 +310,20 @@ SharedHandle<ValueBase> AddTorrentRpcMethod::process
 SharedHandle<ValueBase> AddMetalinkRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  const String* metalinkParam = req.getStringParam(0);
-  if(!metalinkParam) {
-    throw DL_ABORT_EX("Metalink data is not provided.");
-  }
+  const String* metalinkParam = checkRequiredParam<String>(req, 0);
+  const Dict* optsParam = checkParam<Dict>(req, 1);
+  const Integer* posParam = checkParam<Integer>(req, 2);
+
   SharedHandle<String> tempMetalinkParam;
   if(req.jsonRpc) {
     tempMetalinkParam = String::g(Base64::decode(metalinkParam->s()));
     metalinkParam = tempMetalinkParam.get();
   }
   SharedHandle<Option> requestOption(new Option(*e->getOption()));
-  gatherRequestOption(requestOption, req.getDictParam(1));
+  gatherRequestOption(requestOption, optsParam);
 
-  size_t pos = 0;
-  bool posGiven = false;
-  getPosParam(req, 2, posGiven, pos);
+  bool posGiven = checkPosParam(posParam);
+  size_t pos = posGiven ? posParam->i() : 0;
 
   std::vector<SharedHandle<RequestGroup> > result;
 #ifdef ENABLE_MESSAGE_DIGEST
@@ -375,8 +368,9 @@ namespace {
 SharedHandle<ValueBase> removeDownload
 (const RpcRequest& req, DownloadEngine* e, bool forceRemove)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
 
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     e->getRequestGroupMan()->findRequestGroup(gid);
   if(!group) {
@@ -447,8 +441,9 @@ namespace {
 SharedHandle<ValueBase> pauseDownload
 (const RpcRequest& req, DownloadEngine* e, bool forcePause)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
 
+  a2_gid_t gid = str2Gid(gidParam);
   bool reserved = false;
   SharedHandle<RequestGroup> group =
     e->getRequestGroupMan()->findRequestGroup(gid);
@@ -520,7 +515,9 @@ SharedHandle<ValueBase> ForcePauseAllRpcMethod::process
 SharedHandle<ValueBase> UnpauseRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     e->getRequestGroupMan()->findReservedGroup(gid);
   if(!group || !group->isPauseRequested()) {
@@ -919,7 +916,9 @@ void gatherStoppedDownload
 SharedHandle<ValueBase> GetFilesRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<List> files = List::g();
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
@@ -950,7 +949,9 @@ SharedHandle<ValueBase> GetFilesRpcMethod::process
 SharedHandle<ValueBase> GetUrisRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
   if(!group) {
@@ -970,8 +971,9 @@ SharedHandle<ValueBase> GetUrisRpcMethod::process
 SharedHandle<ValueBase> GetPeersRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
 
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
   if(!group) {
@@ -992,9 +994,10 @@ SharedHandle<ValueBase> GetPeersRpcMethod::process
 SharedHandle<ValueBase> TellStatusRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
-  
-  const List* keysParam = req.getListParam(1);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+  const List* keysParam = checkParam<List>(req, 1);
+
+  a2_gid_t gid = str2Gid(gidParam);
   std::vector<std::string> keys;
   toStringList(std::back_inserter(keys), keysParam);
 
@@ -1035,7 +1038,7 @@ SharedHandle<ValueBase> TellStatusRpcMethod::process
 SharedHandle<ValueBase> TellActiveRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  const List* keysParam = req.getListParam(0);
+  const List* keysParam = checkParam<List>(req, 0);
   std::vector<std::string> keys;
   toStringList(std::back_inserter(keys), keysParam);
   SharedHandle<List> list = List::g();
@@ -1100,7 +1103,9 @@ SharedHandle<ValueBase> PurgeDownloadResultRpcMethod::process
 SharedHandle<ValueBase> RemoveDownloadResultRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+
+  a2_gid_t gid = str2Gid(gidParam);
   if(!e->getRequestGroupMan()->removeDownloadResult(gid)) {
     throw DL_ABORT_EX
       (fmt("Could not remove download result of GID#%s",
@@ -1112,8 +1117,10 @@ SharedHandle<ValueBase> RemoveDownloadResultRpcMethod::process
 SharedHandle<ValueBase> ChangeOptionRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+  const Dict* optsParam = checkRequiredParam<Dict>(req, 1);
 
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
   if(!group) {
@@ -1122,38 +1129,33 @@ SharedHandle<ValueBase> ChangeOptionRpcMethod::process
            util::itos(gid).c_str()));
   }
   SharedHandle<Option> option(new Option());
-  const Dict* optionsParam = req.getDictParam(1);
-  if(optionsParam) {
-    gatherChangeableOption(option, optionsParam);
-    applyChangeableOption(group->getOption().get(), option.get());
-    if(option->defined(PREF_MAX_DOWNLOAD_LIMIT)) {
-      group->setMaxDownloadSpeedLimit
-        (option->getAsInt(PREF_MAX_DOWNLOAD_LIMIT));
-    }
-    if(option->defined(PREF_MAX_UPLOAD_LIMIT)) {
-      group->setMaxUploadSpeedLimit(option->getAsInt(PREF_MAX_UPLOAD_LIMIT));
-    }
-#ifdef ENABLE_BITTORRENT
-    BtObject btObject = e->getBtRegistry()->get(group->getGID());
-    if(!btObject.isNull()) {
-      if(option->defined(PREF_BT_MAX_PEERS)) {
-        btObject.btRuntime_->setMaxPeers(option->getAsInt(PREF_BT_MAX_PEERS));
-      }
-    }
-#endif // ENABLE_BITTORRENT
+  gatherChangeableOption(option, optsParam);
+  applyChangeableOption(group->getOption().get(), option.get());
+  if(option->defined(PREF_MAX_DOWNLOAD_LIMIT)) {
+    group->setMaxDownloadSpeedLimit
+      (option->getAsInt(PREF_MAX_DOWNLOAD_LIMIT));
   }
+  if(option->defined(PREF_MAX_UPLOAD_LIMIT)) {
+    group->setMaxUploadSpeedLimit(option->getAsInt(PREF_MAX_UPLOAD_LIMIT));
+  }
+#ifdef ENABLE_BITTORRENT
+  BtObject btObject = e->getBtRegistry()->get(group->getGID());
+  if(!btObject.isNull()) {
+    if(option->defined(PREF_BT_MAX_PEERS)) {
+      btObject.btRuntime_->setMaxPeers(option->getAsInt(PREF_BT_MAX_PEERS));
+    }
+  }
+#endif // ENABLE_BITTORRENT
   return VLB_OK;
 }
 
 SharedHandle<ValueBase> ChangeGlobalOptionRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  const Dict* optionsParam = req.getDictParam(0);
-  if(!optionsParam) {
-    return VLB_OK;
-  }
+  const Dict* optsParam = checkRequiredParam<Dict>(req, 0);
+
   SharedHandle<Option> option(new Option());
-  gatherChangeableGlobalOption(option, optionsParam);
+  gatherChangeableGlobalOption(option, optsParam);
   applyChangeableGlobalOption(e->getOption(), option.get());
 
   if(option->defined(PREF_MAX_OVERALL_DOWNLOAD_LIMIT)) {
@@ -1219,8 +1221,9 @@ void pushRequestOption
 SharedHandle<ValueBase> GetOptionRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
 
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
   if(!group) {
@@ -1251,13 +1254,11 @@ SharedHandle<ValueBase> GetGlobalOptionRpcMethod::process
 SharedHandle<ValueBase> ChangePositionRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
-  const Integer* posParam = req.getIntegerParam(1);
-  const String* howParam = req.getStringParam(2);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+  const Integer* posParam = checkRequiredParam<Integer>(req, 1);
+  const String* howParam = checkRequiredParam<String>(req, 2);
 
-  if(!posParam || !howParam) {
-    throw DL_ABORT_EX("Illegal argument.");
-  }
+  a2_gid_t gid = str2Gid(gidParam);
   int pos = posParam->i();
   const std::string& howStr = howParam->s();
   RequestGroupMan::HOW how;
@@ -1287,7 +1288,9 @@ SharedHandle<ValueBase> GetSessionInfoRpcMethod::process
 SharedHandle<ValueBase> GetServersRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+
+  a2_gid_t gid = str2Gid(gidParam);
   SharedHandle<RequestGroup> group =
     e->getRequestGroupMan()->findRequestGroup(gid);
   if(!group) {
@@ -1326,17 +1329,15 @@ SharedHandle<ValueBase> GetServersRpcMethod::process
 SharedHandle<ValueBase> ChangeUriRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  a2_gid_t gid = getRequiredGidParam(req, 0);
-  const Integer* indexParam = req.getIntegerParam(1);
-  const List* delUrisParam = req.getListParam(2);
-  const List* addUrisParam = req.getListParam(3);
-  if(!indexParam || !delUrisParam || ! addUrisParam) {
-    throw DL_ABORT_EX("Bad request");
-  }
-  size_t pos = 0;
-  bool posGiven = false;
-  getPosParam(req, 4, posGiven, pos);
+  const String* gidParam = checkRequiredParam<String>(req, 0);
+  const Integer* indexParam = checkRequiredParam<Integer>(req, 1);
+  const List* delUrisParam = checkRequiredParam<List>(req, 2);
+  const List* addUrisParam = checkRequiredParam<List>(req, 3);
+  const Integer* posParam = checkParam<Integer>(req, 4);
 
+  a2_gid_t gid = str2Gid(gidParam);
+  bool posGiven = checkPosParam(posParam);
+  size_t pos = posGiven ? posParam->i() : 0;
   size_t index = indexParam->i()-1;
   SharedHandle<RequestGroup> group =
     findRequestGroup(e->getRequestGroupMan(), gid);
@@ -1431,10 +1432,7 @@ SharedHandle<ValueBase> GetGlobalStatRpcMethod::process
 SharedHandle<ValueBase> SystemMulticallRpcMethod::process
 (const RpcRequest& req, DownloadEngine* e)
 {
-  const List* methodSpecs = req.getListParam(0);
-  if(!methodSpecs) {
-    throw DL_ABORT_EX("Illegal argument. One item list is expected.");
-  }
+  const List* methodSpecs = checkRequiredParam<List>(req, 0);
   SharedHandle<List> list = List::g();
   for(List::ValueType::const_iterator i = methodSpecs->begin(),
         eoi = methodSpecs->end(); i != eoi; ++i) {

src/RpcMethodImpl.h

@@ -45,6 +45,7 @@
 #include "ValueBase.h"
 #include "TorrentAttribute.h"
 #include "DlAbortEx.h"
+#include "fmt.h"
 
 namespace aria2 {
 
@@ -53,6 +54,28 @@ class RequestGroup;
 
 namespace rpc {
 
+template<typename T>
+const T* checkParam(const RpcRequest& req, size_t index, bool required = false)
+{
+  const T* p = 0;
+  if(req.params->size() > index) {
+    if((p = downcast<T>(req.params->get(index))) == 0) {
+      throw DL_ABORT_EX(fmt("The parameter at %lu has wrong type.",
+                            static_cast<unsigned long>(index)));
+    }
+  } else if(required) {
+    throw DL_ABORT_EX(fmt("The parameter at %lu is required but missing.",
+                          static_cast<unsigned long>(index)));
+  }
+  return p;
+}
+
+template<typename T>
+const T* checkRequiredParam(const RpcRequest& req, size_t index)
+{
+  return checkParam<T>(req, index, true);
+}
+
 template<typename OutputIterator>
 void toStringList(OutputIterator out, const List* src)
 {
@@ -335,27 +358,19 @@ private:
     std::advance(last, lastDistance);
     return std::make_pair(first, last);
   }
-
-  void checkPaginationParams(const SharedHandle<List>& params) const
-  {
-    if(params->size() < 2) {
-      throw DL_ABORT_EX("Invalid argument. Specify offset and num in integer.");
-    }
-    const Integer* p1 = asInteger(params->get(0));
-    const Integer* p2 = asInteger(params->get(1));
-    if(!p1 || !p2 || p2->i() < 0) {
-      throw DL_ABORT_EX("Invalid argument. Specify offset and num in integer.");
-    }
-  }
 protected:
   virtual SharedHandle<ValueBase> process
   (const RpcRequest& req, DownloadEngine* e)
   {
-    const SharedHandle<List>& params = req.params;
-    checkPaginationParams(params);
-    ssize_t offset = req.getIntegerParam(0)->i();
-    size_t num = req.getIntegerParam(1)->i();
-    const List* keysParam = req.getListParam(2);
+    const Integer* offsetParam = checkRequiredParam<Integer>(req, 0);
+    const Integer* numParam = checkRequiredParam<Integer>(req, 1);
+    const List* keysParam = checkParam<List>(req, 2);
+
+    if(numParam->i() < 0) {
+      throw DL_ABORT_EX("The parameter num must be zero or positive integer.");
+    }
+    ssize_t offset = offsetParam->i();
+    size_t num = numParam->i();
     std::vector<std::string> keys;
     toStringList(std::back_inserter(keys), keysParam);
     const std::deque<SharedHandle<T> >& items = getItems(e);

src/RpcRequest.cc

@@ -64,42 +64,6 @@ RpcRequest& RpcRequest::operator=(const RpcRequest& c)
   return *this;
 }
 
-const String* RpcRequest::getStringParam(size_t index) const
-{
-  const String* stringParam = 0;
-  if(params->size() > index) {
-    stringParam = asString(params->get(index));
-  }
-  return stringParam;
-}
-
-const Integer* RpcRequest::getIntegerParam(size_t index) const
-{
-  const Integer* integerParam = 0;
-  if(params->size() > index) {
-    integerParam = asInteger(params->get(index));
-  }
-  return integerParam;
-}
-
-const List* RpcRequest::getListParam(size_t index) const
-{
-  const List* listParam = 0;
-  if(params->size() > index) {
-    listParam = asList(params->get(index));
-  }
-  return listParam;
-}
-
-const Dict* RpcRequest::getDictParam(size_t index) const
-{
-  const Dict* dictParam = 0;
-  if(params->size() > index) {
-    dictParam = asDict(params->get(index));
-  }
-  return dictParam;
-}
-
 } // namespace rpc
 
 } // namespace aria2

src/RpcRequest.h

@@ -63,14 +63,6 @@ struct RpcRequest {
   RpcRequest(const RpcRequest& c);
 
   RpcRequest& operator=(const RpcRequest& c);
-
-  const String* getStringParam(size_t index) const;
-
-  const Integer* getIntegerParam(size_t index) const;
-
-  const List* getListParam(size_t index) const;
-  
-  const Dict* getDictParam(size_t index) const;
 };
 
 } // namespace rpc