New wire format for REQ/REP pattern

This patch introduces two changes:
1. 32-bit ID is used to identify the peer instead of UUID
2. REQ socket seeds the label stack with unique 32-bit request ID
   It also drops any replies with non-matching request ID

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/src/random.cpp b/src/random.cpp
new file mode 100644
index 0000000..ee7a7fb
--- /dev/null
+++ b/src/random.cpp
@@ -0,0 +1,39 @@
+/*
+    Copyright (c) 2007-2011 iMatix Corporation
+    Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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 "random.hpp"
+#include "uuid.hpp"
+#include "err.hpp"
+
+//  Here we can use different ways of generating random data, as avialable
+//  on different platforms. At the moment, we'll assume the UUID is random
+//  enough to use for that purpose.
+void zmq::generate_random (void *buf_, size_t size_)
+{
+    //  Collapsing an UUID into 4 bytes.
+    zmq_assert (size_ == 4);
+    uint32_t buff [4];
+    generate_uuid ((void*) buff);
+    uint32_t result = buff [0];
+    result ^= buff [1];
+    result ^= buff [2];
+    result ^= buff [3];
+    *((uint32_t*) buf_) = result;
+}