The new options allows querying the maximum allowed number of sockets.
This is system dependent and cannot be encoded in the include file as a
preprocessor macro: for ZMQ_USE_SELECT, this depends on the FD_SETSIZE
macro at time of library compilation, not at time of include file use.
The ${libdir} was getting replaced/removed by configure_file() making pkg-config give bad flags: -L -lzmq
My fix was to add @ONLY to configure_file() so ${} style pkg-config substitutions are left alone.
In addition, I put the other typical ${} substitutions back into the libzmq.pc, since its now safe.
- renamed to ZMQ_CONNECT_RID
- fixed whitespace malformating around previous patch
- renamamed next_peer_id to next_rid in preparation for
larger rename of IDENTITY to ROUTING_ID
Note: ZMQ_CONNECT_RID has no test case and no entry in the man
page, as yet.
This change simply provides the user with a socket option that sets a user defined name of the next outbound connection:
zmq_setsockopt(routerSock,ZMQ_NEXT_IDENTITY,"myname",6);
if(0 > zmq_connect(routerSock,"tcp://127.0.0.1:1234")) return 1;
ret = zmq_send(routerSock,"myname",6,ZMQ_SNDMORE);
zmq_send(routerSock,b.mem,b.used,0);
In this example, the socket is immediately given the name "myname", and is capable of immediately sending traffic.
This approach is more effective in three ways:
1) It prevents all sorts of malicious peer naming attacks that can cause undefined behavior in existing ROUTER connections. (Two connections are made that both transmit the same name to the ROUTER, the ROUTER behavior is undefined)
2) It allows immediate control of connections made to external parties for STREAM sockets. Something that is not possible right now. Before an outbound connection had no name for STREAM or ROUTER sockets because outbound connections cannot be sent to without first receiving traffic.
3) It is simpler and more general than expecting two ROUTER sockets to handshake on assigned connection names. Plus it allows inline sending to new connections on ROUTER.
When a ZMQ_STREAM socket connection is broken (intentionally, via `shutdown()`
or accidentally via client crash or network failure), there is no way for the
application to dertermine that it should drop per-connection data (such as
buffers).
This contribution makes sure the application receives a 0-length message to
notify it that the connection has been broken. This is symmetric with the
process of closing the connection from within the application (where the
application sends a 0-length message to tell ZeroMQ to close the connection).
Conflicts:
CMakeLists.txt
The get_credential () member function returns
credential for the last peer we received message for.
The idea is that this function is used to implement user-level API.
