Generalise RPC connection handling code to allow more listening sockets

Using this modification it should be relatively easy to, at a later
time, listen on multiple addresses (even Unix domain sockets should be
possible).

Signed-off-by: Giel van Schijndel <me@mortis.eu>

src/bitcoinrpc.cpp

@@ -17,6 +17,7 @@
 #include <boost/asio/ip/v6_only.hpp>
 #include <boost/bind.hpp>
 #include <boost/filesystem.hpp>
+#include <boost/foreach.hpp>
 #include <boost/iostreams/concepts.hpp>
 #include <boost/iostreams/stream.hpp>
 #include <boost/algorithm/string.hpp>
@@ -24,7 +25,7 @@
 #include <boost/asio/ssl.hpp> 
 #include <boost/filesystem/fstream.hpp>
 #include <boost/shared_ptr.hpp>
-typedef boost::asio::ssl::stream<boost::asio::ip::tcp::socket> SSLStream;
+#include <list>
 
 #define printf OutputDebugStringF
 // MinGW 3.4.5 gets "fatal error: had to relocate PCH" if the json headers are
@@ -2571,9 +2572,10 @@ bool ClientAllowed(const boost::asio::ip::address& address)
 //
 // IOStream device that speaks SSL but can also speak non-SSL
 //
+template <typename Protocol>
 class SSLIOStreamDevice : public iostreams::device<iostreams::bidirectional> {
 public:
-    SSLIOStreamDevice(SSLStream &streamIn, bool fUseSSLIn) : stream(streamIn)
+    SSLIOStreamDevice(asio::ssl::stream<typename Protocol::socket> &streamIn, bool fUseSSLIn) : stream(streamIn)
     {
         fUseSSL = fUseSSLIn;
         fNeedHandshake = fUseSSLIn;
@@ -2617,21 +2619,54 @@ public:
 private:
     bool fNeedHandshake;
     bool fUseSSL;
-    SSLStream& stream;
+    asio::ssl::stream<typename Protocol::socket>& stream;
 };
 
 class AcceptedConnection
 {
 public:
-    SSLStream sslStream;
-    SSLIOStreamDevice d;
-    iostreams::stream<SSLIOStreamDevice> stream;
+    virtual ~AcceptedConnection() {}
 
-    ip::tcp::endpoint peer;
+    virtual std::iostream& stream() = 0;
+    virtual std::string peer_address_to_string() const = 0;
+    virtual void close() = 0;
+};
+
+template <typename Protocol>
+class AcceptedConnectionImpl : public AcceptedConnection
+{
+public:
+    AcceptedConnectionImpl(
+            asio::io_service& io_service,
+            ssl::context &context,
+            bool fUseSSL) :
+        sslStream(io_service, context),
+        _d(sslStream, fUseSSL),
+        _stream(_d)
+    {
+    }
+
+    virtual std::iostream& stream()
+    {
+        return _stream;
+    }
+
+    virtual std::string peer_address_to_string() const
+    {
+        return peer.address().to_string();
+    }
 
-    AcceptedConnection(asio::io_service &io_service, ssl::context &context,
-     bool fUseSSL) : sslStream(io_service, context), d(sslStream, fUseSSL),
-     stream(d) { ; }
+    virtual void close()
+    {
+        _stream.close();
+    }
+
+    typename Protocol::endpoint peer;
+    asio::ssl::stream<typename Protocol::socket> sslStream;
+
+private:
+    SSLIOStreamDevice<Protocol> _d;
+    iostreams::stream< SSLIOStreamDevice<Protocol> > _stream;
 };
 
 void ThreadRPCServer(void* parg)
@@ -2654,7 +2689,8 @@ void ThreadRPCServer(void* parg)
 }
 
 // Forward declaration required for RPCListen
-static void RPCAcceptHandler(boost::shared_ptr<ip::tcp::acceptor> acceptor,
+template <typename Protocol, typename SocketAcceptorService>
+static void RPCAcceptHandler(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketAcceptorService> > acceptor,
                              ssl::context& context,
                              bool fUseSSL,
                              AcceptedConnection* conn,
@@ -2663,18 +2699,19 @@ static void RPCAcceptHandler(boost::shared_ptr<ip::tcp::acceptor> acceptor,
 /**
  * Sets up I/O resources to accept and handle a new connection.
  */
-static void RPCListen(boost::shared_ptr<ip::tcp::acceptor> acceptor,
+template <typename Protocol, typename SocketAcceptorService>
+static void RPCListen(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketAcceptorService> > acceptor,
                    ssl::context& context,
                    const bool fUseSSL)
 {
 
     // Accept connection
-    AcceptedConnection* conn = new AcceptedConnection(acceptor->get_io_service(), context, fUseSSL);
+    AcceptedConnectionImpl<Protocol>* conn = new AcceptedConnectionImpl<Protocol>(acceptor->get_io_service(), context, fUseSSL);
 
     acceptor->async_accept(
             conn->sslStream.lowest_layer(),
             conn->peer,
-            boost::bind(&RPCAcceptHandler,
+            boost::bind(&RPCAcceptHandler<Protocol, SocketAcceptorService>,
                 acceptor,
                 boost::ref(context),
                 fUseSSL,
@@ -2685,7 +2722,8 @@ static void RPCListen(boost::shared_ptr<ip::tcp::acceptor> acceptor,
 /**
  * Accept and handle incoming connection.
  */
-static void RPCAcceptHandler(boost::shared_ptr<ip::tcp::acceptor> acceptor,
+template <typename Protocol, typename SocketAcceptorService>
+static void RPCAcceptHandler(boost::shared_ptr< basic_socket_acceptor<Protocol, SocketAcceptorService> > acceptor,
                              ssl::context& context,
                              const bool fUseSSL,
                              AcceptedConnection* conn,
@@ -2696,6 +2734,8 @@ static void RPCAcceptHandler(boost::shared_ptr<ip::tcp::acceptor> acceptor,
     // Immediately start accepting new connections
     RPCListen(acceptor, context, fUseSSL);
 
+    AcceptedConnectionImpl<ip::tcp>* tcp_conn = dynamic_cast< AcceptedConnectionImpl<ip::tcp>* >(conn);
+
     // TODO: Actually handle errors
     if (error)
     {
@@ -2705,11 +2745,12 @@ static void RPCAcceptHandler(boost::shared_ptr<ip::tcp::acceptor> acceptor,
     // Restrict callers by IP.  It is important to
     // do this before starting client thread, to filter out
     // certain DoS and misbehaving clients.
-    else if (!ClientAllowed(conn->peer.address()))
+    else if (tcp_conn
+          && !ClientAllowed(tcp_conn->peer.address()))
     {
         // Only send a 403 if we're not using SSL to prevent a DoS during the SSL handshake.
         if (!fUseSSL)
-            conn->stream << HTTPReply(403, "", false) << std::flush;
+            conn->stream() << HTTPReply(403, "", false) << std::flush;
         delete conn;
     }
 
@@ -2778,21 +2819,21 @@ void ThreadRPCServer2(void* parg)
     asio::ip::address bindAddress = loopback ? asio::ip::address_v6::loopback() : asio::ip::address_v6::any();
     ip::tcp::endpoint endpoint(bindAddress, GetArg("-rpcport", 8332));
 
-    boost::shared_ptr<ip::tcp::acceptor> acceptor, acceptor4;
+    std::list< boost::shared_ptr<ip::tcp::acceptor> > acceptors;
     try
     {
-        acceptor.reset(new ip::tcp::acceptor(io_service));
-        acceptor->open(endpoint.protocol());
-        acceptor->set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
+        acceptors.push_back(boost::shared_ptr<ip::tcp::acceptor>(new ip::tcp::acceptor(io_service)));
+        acceptors.back()->open(endpoint.protocol());
+        acceptors.back()->set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
 
         // Try making the socket dual IPv6/IPv4 (if listening on the "any" address)
         boost::system::error_code v6_only_error;
-        acceptor->set_option(boost::asio::ip::v6_only(loopback), v6_only_error);
+        acceptors.back()->set_option(boost::asio::ip::v6_only(loopback), v6_only_error);
 
-        acceptor->bind(endpoint);
-        acceptor->listen(socket_base::max_connections);
+        acceptors.back()->bind(endpoint);
+        acceptors.back()->listen(socket_base::max_connections);
 
-        RPCListen(acceptor, context, fUseSSL);
+        RPCListen(acceptors.back(), context, fUseSSL);
 
         // If dual IPv6/IPv4 failed (or we're opening loopback interfaces only), open IPv4 separately
         if (loopback || v6_only_error)
@@ -2800,13 +2841,13 @@ void ThreadRPCServer2(void* parg)
             bindAddress = loopback ? asio::ip::address_v4::loopback() : asio::ip::address_v4::any();
             endpoint.address(bindAddress);
 
-            acceptor4.reset(new ip::tcp::acceptor(io_service));
-            acceptor4->open(endpoint.protocol());
-            acceptor4->set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
-            acceptor4->bind(endpoint);
-            acceptor4->listen(socket_base::max_connections);
+            acceptors.push_back(boost::shared_ptr<ip::tcp::acceptor>(new ip::tcp::acceptor(io_service)));
+            acceptors.back()->open(endpoint.protocol());
+            acceptors.back()->set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
+            acceptors.back()->bind(endpoint);
+            acceptors.back()->listen(socket_base::max_connections);
 
-            RPCListen(acceptor4, context, fUseSSL);
+            RPCListen(acceptors.back(), context, fUseSSL);
         }
     }
     catch(boost::system::system_error &e)
@@ -2821,6 +2862,19 @@ void ThreadRPCServer2(void* parg)
     while (!fShutdown)
         io_service.run_one();
     vnThreadsRunning[THREAD_RPCLISTENER]++;
+
+    // Terminate all outstanding accept-requests
+    BOOST_FOREACH(boost::shared_ptr<ip::tcp::acceptor>& acceptor, acceptors)
+    {
+        acceptor->cancel();
+        acceptor->close();
+    }
+    acceptors.clear();
+
+    // Handle any actions that are still in progress.
+    vnThreadsRunning[THREAD_RPCLISTENER]--;
+    io_service.run();
+    vnThreadsRunning[THREAD_RPCLISTENER]++;
 }
 
 void ThreadRPCServer3(void* parg)
@@ -2833,7 +2887,7 @@ void ThreadRPCServer3(void* parg)
     loop {
         if (fShutdown || !fRun)
         {
-            conn->stream.close();
+            conn->close();
             delete conn;
             --vnThreadsRunning[THREAD_RPCHANDLER];
             return;
@@ -2841,24 +2895,24 @@ void ThreadRPCServer3(void* parg)
         map<string, string> mapHeaders;
         string strRequest;
 
-        ReadHTTP(conn->stream, mapHeaders, strRequest);
+        ReadHTTP(conn->stream(), mapHeaders, strRequest);
 
         // Check authorization
         if (mapHeaders.count("authorization") == 0)
         {
-            conn->stream << HTTPReply(401, "", false) << std::flush;
+            conn->stream() << HTTPReply(401, "", false) << std::flush;
             break;
         }
         if (!HTTPAuthorized(mapHeaders))
         {
-            printf("ThreadRPCServer incorrect password attempt from %s\n", conn->peer.address().to_string().c_str());
+            printf("ThreadRPCServer incorrect password attempt from %s\n", conn->peer_address_to_string().c_str());
             /* Deter brute-forcing short passwords.
                If this results in a DOS the user really
                shouldn't have their RPC port exposed.*/
             if (mapArgs["-rpcpassword"].size() < 20)
                 Sleep(250);
 
-            conn->stream << HTTPReply(401, "", false) << std::flush;
+            conn->stream() << HTTPReply(401, "", false) << std::flush;
             break;
         }
         if (mapHeaders["connection"] == "close")
@@ -2900,16 +2954,16 @@ void ThreadRPCServer3(void* parg)
 
             // Send reply
             string strReply = JSONRPCReply(result, Value::null, id);
-            conn->stream << HTTPReply(200, strReply, fRun) << std::flush;
+            conn->stream() << HTTPReply(200, strReply, fRun) << std::flush;
         }
         catch (Object& objError)
         {
-            ErrorReply(conn->stream, objError, id);
+            ErrorReply(conn->stream(), objError, id);
             break;
         }
         catch (std::exception& e)
         {
-            ErrorReply(conn->stream, JSONRPCError(-32700, e.what()), id);
+            ErrorReply(conn->stream(), JSONRPCError(-32700, e.what()), id);
             break;
         }
     }
@@ -2961,9 +3015,9 @@ Object CallRPC(const string& strMethod, const Array& params)
     asio::io_service io_service;
     ssl::context context(io_service, ssl::context::sslv23);
     context.set_options(ssl::context::no_sslv2);
-    SSLStream sslStream(io_service, context);
-    SSLIOStreamDevice d(sslStream, fUseSSL);
-    iostreams::stream<SSLIOStreamDevice> stream(d);
+    asio::ssl::stream<asio::ip::tcp::socket> sslStream(io_service, context);
+    SSLIOStreamDevice<asio::ip::tcp> d(sslStream, fUseSSL);
+    iostreams::stream< SSLIOStreamDevice<asio::ip::tcp> > stream(d);
     if (!d.connect(GetArg("-rpcconnect", "127.0.0.1"), GetArg("-rpcport", "8332")))
         throw runtime_error("couldn't connect to server");