ZeroMQ Interface

File: csp/interfaces/csp_if_zmqhub.h

Description: ZMQ (ZeroMQ) interface.

The ZMQ interface is designed to connect to a ZMQ hub, also refered to as zmqproxy. The zmqproxy can be found under examples, and is based on zmq_proxy() - provided by the ZMQ API.

For further details on ZMQ, see http://www.zeromq.org.

Defines

CSP_ZMQ_MTU

max payload data, see documentation

CSP_ZMQPROXY_SUBSCRIBE_PORT

zmqproxy default subscribe (rx) port. The client must connect it’s publish endpoint to the zmqproxy’s subscribe port.

CSP_ZMQPROXY_PUBLISH_PORT

zmqproxy default publish (tx) port. The client must connect it’s subscribe endpoint to the zmqproxy’s publish port.

CSP_ZMQHUB_IF_NAME

Default ZMQ interface name.

Interface Functions

int csp_zmqhub_make_endpoint(const char *host, uint16_t port, char *buf, size_t buf_size)

Format endpoint connection string for ZMQ.

Parameters:

• host – host name of IP.

• port – IP port.

• buf – user allocated buffer for receiving formatted string.

• buf_size – size of buf.

Returns:

#CSP_ERR_NONE on succcess. #CSP_ERR_NOMEM if supplied buffer too small.

int csp_zmqhub_init(uint16_t addr, const char *host, uint32_t flags, csp_iface_t **return_interface)

Setup ZMQ interface.

Parameters:

• addr – only receive messages matching this address (255 means all). This is set as rx_filter in call to

• host – host name or IP of zmqproxy host. Endpoints are created using the host and the default subscribe/publish ports.

• flags – flags for controlling features on the connection.

• return_interface – created CSP interface.

Returns:

#CSP_ERR_NONE on succcess - else assert.

int csp_zmqhub_init_w_endpoints(uint16_t addr, const char *publish_endpoint, const char *subscribe_endpoint, uint32_t flags, csp_iface_t **return_interface)

Setup ZMQ interface.

Parameters:

• addr – only receive messages matching this address (255 means all). This is set as a rx_filter.

• publish_endpoint – publish (tx) endpoint -> connect to zmqproxy’s subscribe port #CSP_ZMQPROXY_SUBSCRIBE_PORT.

• subscribe_endpoint – subscribe (rx) endpoint -> connect to zmqproxy’s publish port #CSP_ZMQPROXY_PUBLISH_PORT.

• flags – flags for controlling features on the connection.

• return_interface – created CSP interface.

Returns:

#CSP_ERR_NONE on succcess - else assert.

int csp_zmqhub_init_w_name_endpoints_rxfilter(const char *ifname, uint16_t addr, const uint16_t rx_filter[], unsigned int rx_filter_count, const char *publish_endpoint, const char *subscribe_endpoint, uint32_t flags, csp_iface_t **return_interface)

Setup ZMQ interface.

Parameters:

• ifname – Name of CSP interface, use NULL for default name #CSP_ZMQHUB_IF_NAME.

• addr – Address assigned to the CSP interface. rx_filter (const uint16_t) [in]: Rx filters, use NULL for no filters - receive all messages. rx_filter_count (unsigned int) [in]: Number of Rx filters in rx_filter.

• publish_endpoint – publish (tx) endpoint -> connect to zmqproxy’s subscribe port #CSP_ZMQPROXY_SUBSCRIBE_PORT.

• subscribe_endpoint – subscribe (rx) endpoint -> connect to zmqproxy’s publish port #CSP_ZMQPROXY_PUBLISH_PORT.

• flags – flags for controlling features on the connection.

• return_interface – created CSP interface.

Returns:

#CSP_ERR_NONE on succcess - else assert.

int csp_zmqhub_init_filter2(const char *ifname, const char *host, uint16_t addr, uint16_t netmask, int promisc, csp_iface_t **return_interface, char *sec_key, uint16_t subport, uint16_t pubport)

Setup filtered ZMQ interface. The filter can be enabled with promisc = 0, or disabled with promisc = 1.

The filter only works with CSP 2.0 protocol, because the first two bytes are the priority and the destination address. ZMQ does not support masking, so the code actually subscribes to the address once for each priority. It also calculates the broadcast address and subscribes to that, aagin for each priority. Finally the global broadcast address is also subscribed to. meaning a total of 3 * 4 filters.

If a secret key curve zmq is enabled