Check the availability of ares_set_servers and ares_addr_node.

m4/libcares.m4

@@ -26,7 +26,10 @@ if test "x$have_libcares" != "xyes"; then
 fi
 
 if test "x$have_libcares" = "xyes"; then
-
+    if test "x$need_librt" = "xyes"; then
+      LIBS="-lrt $LIBS"
+    fi
+    LIBS="-lcares $LIBS"
     AC_MSG_CHECKING([whether ares_host_callback accepts timeouts(c-ares >= 1.5)])
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
     #include <ares.h>
@@ -43,6 +46,8 @@ if test "x$have_libcares" = "xyes"; then
     if test "x$have_libcares1_5" = "xyes"; then
         AC_DEFINE([HAVE_LIBCARES1_5], [1], [Define 1 if ares_host_callback accepts timeouts(c-ares >= 1.5)])
     fi
+    AC_CHECK_TYPES([ares_addr_node], [], [], [[#include <ares.h>]])
+    AC_CHECK_FUNCS([ares_set_servers])
 
     AC_DEFINE([HAVE_LIBCARES], [1], [Define to 1 if you have libcares.])
     LIBCARES_LIBS="-L$libcares_prefix_lib -lcares"

src/AbstractCommand.cc

@@ -651,7 +651,12 @@ void AbstractCommand::initAsyncNameResolver(const std::string& hostname)
     family = AF_INET;
   }
   asyncNameResolver_.reset
-    (new AsyncNameResolver(family, e_->getAsyncDNSServers()));
+    (new AsyncNameResolver(family
+#ifdef HAVE_ARES_ADDR_NODE
+                           ,
+                           e_->getAsyncDNSServers()
+#endif // HAVE_ARES_ADDR_NODE
+                           ));
   A2_LOG_INFO(fmt(MSG_RESOLVING_HOSTNAME,
                   getCuid(),
                   hostname.c_str()));

src/AsyncNameResolver.cc

@@ -78,18 +78,25 @@ void callback(void* arg, int status, int timeouts, struct hostent* host)
   }
 }
 
-AsyncNameResolver::AsyncNameResolver(int family, ares_addr_node* servers):
+AsyncNameResolver::AsyncNameResolver
-  status_(STATUS_READY),
+(int family
+#ifdef HAVE_ARES_ADDR_NODE
+ , ares_addr_node* servers
+#endif // HAVE_ARES_ADDR_NODE
+ )
+  : status_(STATUS_READY),
     family_(family)
 {
   // TODO evaluate return value
   ares_init(&channel_);
+#if defined HAVE_ARES_SET_SERVERS && HAVE_ARES_ADDR_NODE
   if(servers) {
     // ares_set_servers has been added since c-ares 1.7.1
     if(ares_set_servers(channel_, servers) != ARES_SUCCESS) {
       A2_LOG_DEBUG("ares_set_servers failed");
     }
   }
+#endif // HAVE_ARES_SET_SERVERS && HAVE_ARES_ADDR_NODE
 }
 
 AsyncNameResolver::~AsyncNameResolver()

src/AsyncNameResolver.h

@@ -70,7 +70,12 @@ private:
   std::string error_;
   std::string hostname_;
 public:
-  AsyncNameResolver(int family, ares_addr_node* servers);
+  AsyncNameResolver
+  (int family
+#ifdef HAVE_ARES_ADDR_NODE
+   , ares_addr_node* servers
+#endif // HAVE_ARES_ADDR_NODE
+   );
 
   ~AsyncNameResolver();
 

src/DHTEntryPointNameResolveCommand.cc

@@ -84,7 +84,11 @@ bool DHTEntryPointNameResolveCommand::execute()
     } else {
       family = AF_INET;
     }
-    resolver_.reset(new AsyncNameResolver(family, e_->getAsyncDNSServers()));
+    resolver_.reset(new AsyncNameResolver(family
+#ifdef HAVE_ARES_ADDR_NODE
+                                          , e_->getAsyncDNSServers()
+#endif // HAVE_ARES_ADDR_NODE
+                                          ));
   }
 #endif // ENABLE_ASYNC_DNS
   try {

src/DownloadEngine.cc

@@ -95,9 +95,9 @@ DownloadEngine::DownloadEngine(const SharedHandle<EventPoll>& eventPoll)
 #ifdef ENABLE_BITTORRENT
     btRegistry_(new BtRegistry()),
 #endif // ENABLE_BITTORRENT
-#ifdef ENABLE_ASYNC_DNS
+#ifdef HAVE_ARES_ADDR_NODE
     asyncDNSServers_(0),
-#endif // ENABLE_ASYNC_DNS
+#endif // HAVE_ARES_ADDR_NODE
     dnsCache_(new DNSCache())
 {
   unsigned char sessionId[20];
@@ -107,7 +107,9 @@ DownloadEngine::DownloadEngine(const SharedHandle<EventPoll>& eventPoll)
 
 DownloadEngine::~DownloadEngine() {
   cleanQueue();
+#ifdef HAVE_ARES_ADDR_NODE
   setAsyncDNSServers(0);
+#endif // HAVE_ARES_ADDR_NODE
 }
 
 void DownloadEngine::cleanQueue() {
@@ -564,6 +566,7 @@ void DownloadEngine::setCheckIntegrityMan
   checkIntegrityMan_ = ciman;
 }
 
+#ifdef HAVE_ARES_ADDR_NODE
 void DownloadEngine::setAsyncDNSServers(ares_addr_node* asyncDNSServers)
 {
   ares_addr_node* node = asyncDNSServers_;
@@ -574,5 +577,6 @@ void DownloadEngine::setAsyncDNSServers(ares_addr_node* asyncDNSServers)
   }
   asyncDNSServers_ = asyncDNSServers;
 }
+#endif // HAVE_ARES_ADDR_NODE
 
 } // namespace aria2

src/DownloadEngine.h

@@ -135,9 +135,9 @@ private:
 
   CUIDCounter cuidCounter_;
 
-#ifdef ENABLE_ASYNC_DNS
+#ifdef HAVE_ARES_ADDR_NODE
   ares_addr_node* asyncDNSServers_;
-#endif // ENABLE_ASYNC_DNS
+#endif // HAVE_ARES_ADDR_NODE
 
   SharedHandle<DNSCache> dnsCache_;
 
@@ -331,12 +331,14 @@ public:
     return sessionId_;
   }
 
+#ifdef HAVE_ARES_ADDR_NODE
   void setAsyncDNSServers(ares_addr_node* asyncDNSServers);
 
   ares_addr_node* getAsyncDNSServers() const
   {
     return asyncDNSServers_;
   }
+#endif // HAVE_ARES_ADDR_NODE
 };
 
 typedef SharedHandle<DownloadEngine> DownloadEngineHandle;

src/MultiUrlRequestInfo.cc

@@ -215,10 +215,11 @@ error_code::Value MultiUrlRequestInfo::execute()
     }
     SocketCore::setTLSContext(tlsContext);
 #endif
+#ifdef HAVE_ARES_ADDR_NODE
     ares_addr_node* asyncDNSServers =
       parseAsyncDNSServers(option_->get(PREF_ASYNC_DNS_SERVER));
     e->setAsyncDNSServers(asyncDNSServers);
-
+#endif // HAVE_ARES_ADDR_NODE
     if(!Timer::monotonicClock()) {
       A2_LOG_WARN("Don't change system time while aria2c is running."
                   " Doing this may make aria2c hang for long time.");

src/OptionHandlerFactory.cc

@@ -89,6 +89,7 @@ OptionHandlers OptionHandlerFactory::createOptionHandlers()
     op->addTag(TAG_ADVANCED);
     handlers.push_back(op);
   }
+#if defined HAVE_ARES_SET_SERVERS && HAVE_ARES_ADDR_NODE
   {
     SharedHandle<OptionHandler> op(new DefaultOptionHandler
                                    (PREF_ASYNC_DNS_SERVER,
@@ -97,6 +98,7 @@ OptionHandlers OptionHandlerFactory::createOptionHandlers()
     op->addTag(TAG_ADVANCED);
     handlers.push_back(op);
   }
+#endif // HAVE_ARES_SET_SERVERS && HAVE_ARES_ADDR_NODE
 #endif // ENABLE_ASYNC_DNS
   {
     SharedHandle<OptionHandler> op(new BooleanOptionHandler