Problem: ZAP client code is duplicated in all mechanisms

Solution: created a zap_client_t class, extracted first function send_zap_request from curve_server_t

CMakeLists.txt

@@ -565,7 +565,8 @@ set (cxx-sources
         udp_engine.cpp
         udp_address.cpp
         scatter.cpp
-        gather.cpp)
+        gather.cpp
+		zap_client.cpp)
 
 set (rc-sources version.rc)
 

Makefile.am

@@ -242,6 +242,8 @@ src_libzmq_la_SOURCES = \
 	src/decoder_allocators.hpp \
 	src/socket_poller.cpp \
 	src/socket_poller.hpp \
+	src/zap_client.cpp \
+	src/zap_client.hpp \
 	src/zmq_draft.h
 
 if USE_TWEETNACL

builds/gyp/project.gyp

@@ -272,6 +272,8 @@
         '../../src/ypipe_base.hpp',
         '../../src/ypipe_conflate.hpp',
         '../../src/yqueue.hpp',
+        '../../src/zap_client.cpp',
+        '../../src/zap_client.hpp',
         '../../src/zmq.cpp',
         '../../src/zmq_utils.cpp'
       ],

src/curve_server.cpp

@@ -44,10 +44,11 @@ zmq::curve_server_t::curve_server_t (session_base_t *session_,
     mechanism_t (options_),
     session (session_),
     peer_address (peer_address_),
+    zap_client (session, peer_address, options),
     state (expect_hello),
     current_error_detail (no_detail),
     cn_nonce (1),
-    cn_peer_nonce(1)
+    cn_peer_nonce (1)
 {
     int rc;
     //  Fetch our secret key from socket options
@@ -602,85 +603,8 @@ int zmq::curve_server_t::produce_error (msg_t *msg_) const
 
 int zmq::curve_server_t::send_zap_request (const uint8_t *key)
 {
-    // TODO  I don't think the rc can be -1 anywhere below.
-    // It might only be -1 if the HWM was exceeded, but on the ZAP socket, 
-    // the HWM is disabled. They should be changed to zmq_assert (rc == 0);
-    // The method's return type can be changed to void then.
-
-    int rc;
-    msg_t msg;
-
-    //  Address delimiter frame
-    rc = msg.init ();
-    errno_assert (rc == 0);
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Version frame
-    rc = msg.init_size (3);
-    errno_assert (rc == 0);
-    memcpy (msg.data (), "1.0", 3);
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Request ID frame
-    rc = msg.init_size (1);
-    errno_assert (rc == 0);
-    memcpy (msg.data (), "1", 1);
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Domain frame
-    rc = msg.init_size (options.zap_domain.length ());
-    errno_assert (rc == 0);
-    memcpy (msg.data (), options.zap_domain.c_str (), options.zap_domain.length ());
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Address frame
-    rc = msg.init_size (peer_address.length ());
-    errno_assert (rc == 0);
-    memcpy (msg.data (), peer_address.c_str (), peer_address.length ());
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Identity frame
-    rc = msg.init_size (options.identity_size);
-    errno_assert (rc == 0);
-    memcpy (msg.data (), options.identity, options.identity_size);
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Mechanism frame
-    rc = msg.init_size (5);
-    errno_assert (rc == 0);
-    memcpy (msg.data (), "CURVE", 5);
-    msg.set_flags (msg_t::more);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    //  Credentials frame
-    rc = msg.init_size (crypto_box_PUBLICKEYBYTES);
-    errno_assert (rc == 0);
-    memcpy (msg.data (), key, crypto_box_PUBLICKEYBYTES);
-    rc = session->write_zap_msg (&msg);
-    if (rc != 0)
-        return close_and_return (&msg, -1);
-
-    return 0;
+    return zap_client.send_zap_request ("CURVE", 5, key,
+                                        crypto_box_PUBLICKEYBYTES);
 }
 
 int zmq::curve_server_t::receive_and_process_zap_reply ()

src/curve_server.hpp

@@ -51,6 +51,7 @@
 
 #include "mechanism.hpp"
 #include "options.hpp"
+#include "zap_client.hpp"
 
 namespace zmq
 {
@@ -93,6 +94,8 @@ namespace zmq
 
         const std::string peer_address;
 
+        zap_client_t zap_client;
+
         //  Current FSM state
         state_t state;
 

src/zap_client.cpp

+/*
+    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "precompiled.hpp"
+
+#include "zap_client.hpp"
+#include "msg.hpp"
+
+namespace zmq
+{
+int zap_client_t::send_zap_request (const char *mechanism,
+                                    size_t mechanism_length,
+                                    const uint8_t *credentials,
+                                    size_t credentials_size)
+{
+    // TODO  I don't think the rc can be -1 anywhere below.
+    // It might only be -1 if the HWM was exceeded, but on the ZAP socket,
+    // the HWM is disabled. They should be changed to zmq_assert (rc == 0);
+    // The method's return type can be changed to void then.
+
+    int rc;
+    msg_t msg;
+
+    //  Address delimiter frame
+    rc = msg.init ();
+    errno_assert (rc == 0);
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Version frame
+    rc = msg.init_size (3);
+    errno_assert (rc == 0);
+    memcpy (msg.data (), "1.0", 3);
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Request ID frame
+    rc = msg.init_size (1);
+    errno_assert (rc == 0);
+    memcpy (msg.data (), "1", 1);
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Domain frame
+    rc = msg.init_size (options.zap_domain.length ());
+    errno_assert (rc == 0);
+    memcpy (msg.data (), options.zap_domain.c_str (),
+            options.zap_domain.length ());
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Address frame
+    rc = msg.init_size (peer_address.length ());
+    errno_assert (rc == 0);
+    memcpy (msg.data (), peer_address.c_str (), peer_address.length ());
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Identity frame
+    rc = msg.init_size (options.identity_size);
+    errno_assert (rc == 0);
+    memcpy (msg.data (), options.identity, options.identity_size);
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Mechanism frame
+    rc = msg.init_size (mechanism_length);
+    errno_assert (rc == 0);
+    memcpy (msg.data (), mechanism, mechanism_length);
+    msg.set_flags (msg_t::more);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    //  Credentials frame
+    rc = msg.init_size (credentials_size);
+    errno_assert (rc == 0);
+    memcpy (msg.data (), credentials, credentials_size);
+    rc = session->write_zap_msg (&msg);
+    if (rc != 0)
+        return close_and_return (&msg, -1);
+
+    return 0;
+}
+}

src/zap_client.hpp

+/*
+    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_ZAP_CLIENT_HPP_INCLUDED__
+#define __ZMQ_ZAP_CLIENT_HPP_INCLUDED__
+
+#include "session_base.hpp"
+
+namespace zmq
+{
+class zap_client_t
+{
+  public:
+    zap_client_t (session_base_t *const session_,
+                  const std::string &peer_address_,
+                  const options_t &options_) :
+        session (session_),
+        peer_address (peer_address_),
+        options (options_)
+    {
+    }
+
+    int send_zap_request (const char *mechanism,
+                          size_t mechanism_length,
+                          const uint8_t *credentials,
+                          size_t credentials_size);
+
+  private:
+    session_base_t *const session;
+    const std::string &peer_address;
+    const options_t &options;
+};
+}
+
+#endif