You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
213 lines
7.6 KiB
213 lines
7.6 KiB
'\" t
|
|
.\" Title: zbeacon_v2
|
|
.\" Author: [see the "AUTHORS" section]
|
|
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
|
|
.\" Date: 09/14/2016
|
|
.\" Manual: CZMQ Manual
|
|
.\" Source: CZMQ 3.0.2
|
|
.\" Language: English
|
|
.\"
|
|
.TH "ZBEACON_V2" "3" "09/14/2016" "CZMQ 3\&.0\&.2" "CZMQ Manual"
|
|
.\" -----------------------------------------------------------------
|
|
.\" * Define some portability stuff
|
|
.\" -----------------------------------------------------------------
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
.\" http://bugs.debian.org/507673
|
|
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
.ie \n(.g .ds Aq \(aq
|
|
.el .ds Aq '
|
|
.\" -----------------------------------------------------------------
|
|
.\" * set default formatting
|
|
.\" -----------------------------------------------------------------
|
|
.\" disable hyphenation
|
|
.nh
|
|
.\" disable justification (adjust text to left margin only)
|
|
.ad l
|
|
.\" -----------------------------------------------------------------
|
|
.\" * MAIN CONTENT STARTS HERE *
|
|
.\" -----------------------------------------------------------------
|
|
.SH "NAME"
|
|
zbeacon_v2 \- LAN discovery and presence (deprecated)
|
|
.SH "SYNOPSIS"
|
|
.sp
|
|
.nf
|
|
// Create a new beacon on a certain UDP port\&. If the system does not
|
|
// support UDP broadcasts (lacking a useful interface), returns NULL\&.
|
|
// To force the beacon to operate on a given port, set the environment
|
|
// variable ZSYS_INTERFACE, or call zsys_set_interface() beforehand\&.
|
|
// If you are using the new zsock API then pass NULL as the ctx here\&.
|
|
CZMQ_EXPORT zbeacon_t *
|
|
zbeacon_new (zctx_t *ctx, int port_nbr);
|
|
|
|
// Destroy a beacon
|
|
CZMQ_EXPORT void
|
|
zbeacon_destroy (zbeacon_t **self_p);
|
|
|
|
// Return our own IP address as printable string
|
|
CZMQ_EXPORT char *
|
|
zbeacon_hostname (zbeacon_t *self);
|
|
|
|
// Set broadcast interval in milliseconds (default is 1000 msec)
|
|
CZMQ_EXPORT void
|
|
zbeacon_set_interval (zbeacon_t *self, int interval);
|
|
|
|
// Filter out any beacon that looks exactly like ours
|
|
CZMQ_EXPORT void
|
|
zbeacon_noecho (zbeacon_t *self);
|
|
|
|
// Start broadcasting beacon to peers at the specified interval
|
|
CZMQ_EXPORT void
|
|
zbeacon_publish (zbeacon_t *self, byte *transmit, size_t size);
|
|
|
|
// Stop broadcasting beacons
|
|
CZMQ_EXPORT void
|
|
zbeacon_silence (zbeacon_t *self);
|
|
|
|
// Start listening to other peers; zero\-sized filter means get everything
|
|
CZMQ_EXPORT void
|
|
zbeacon_subscribe (zbeacon_t *self, byte *filter, size_t size);
|
|
|
|
// Stop listening to other peers
|
|
CZMQ_EXPORT void
|
|
zbeacon_unsubscribe (zbeacon_t *self);
|
|
|
|
// Get beacon ZeroMQ socket, for polling or receiving messages
|
|
CZMQ_EXPORT void *
|
|
zbeacon_socket (zbeacon_t *self);
|
|
|
|
// Self test of this class
|
|
CZMQ_EXPORT void
|
|
zbeacon_v2_test (bool verbose);
|
|
.fi
|
|
.SH "DESCRIPTION"
|
|
.sp
|
|
The zbeacon class implements a peer\-to\-peer discovery service for local networks\&. A beacon can broadcast and/or capture service announcements using UDP messages on the local area network\&. This implementation uses IPv4 UDP broadcasts\&. You can define the format of your outgoing beacons, and set a filter that validates incoming beacons\&. Beacons are sent and received asynchronously in the background\&. The zbeacon API provides a incoming beacons on a ZeroMQ socket (the pipe) that you can configure, poll on, and receive messages on\&. Incoming beacons are always delivered as two frames: the ipaddress of the sender (a string), and the beacon data itself (binary, as published)\&.
|
|
.sp
|
|
This class is deprecated in CZMQ v3; it works together with zctx, zsocket, and other deprecated V2 classes\&. New applications should use the V3 zauth interface, based on zactor, together with the zsock class for sockets\&.
|
|
.SH "EXAMPLE"
|
|
.PP
|
|
\fBFrom zbeacon_v2_test method\fR.
|
|
.sp
|
|
.if n \{\
|
|
.RS 4
|
|
.\}
|
|
.nf
|
|
// Create beacon to broadcast our service
|
|
zctx_t *ctx = zctx_new ();
|
|
assert (ctx);
|
|
zbeacon_t *service_beacon = zbeacon_new (ctx, 9999);
|
|
if (service_beacon == NULL) {
|
|
printf ("OK (skipping test, no UDP discovery)\en");
|
|
return;
|
|
}
|
|
// Create a service socket and bind to an ephemeral port
|
|
zsock_t *service = zsock_new (ZMQ_PUB);
|
|
assert (service);
|
|
int port_nbr = zsock_bind (service, "tcp://127\&.0\&.0\&.1:*");
|
|
byte announcement [2] = { (port_nbr >> 8) & 0xFF, port_nbr & 0xFF };
|
|
zbeacon_set_interval (service_beacon, 100);
|
|
zbeacon_publish (service_beacon, announcement, 2);
|
|
|
|
// Create beacon to lookup service
|
|
zbeacon_t *client_beacon = zbeacon_new (ctx, 9999);
|
|
assert (client_beacon);
|
|
zbeacon_subscribe (client_beacon, NULL, 0);
|
|
|
|
// Wait for at most 1/2 second if there\*(Aqs no broadcast networking
|
|
zsocket_set_rcvtimeo (zbeacon_socket (client_beacon), 500);
|
|
|
|
char *ipaddress = zstr_recv (zbeacon_socket (client_beacon));
|
|
if (ipaddress) {
|
|
zframe_t *content = zframe_recv (zbeacon_socket (client_beacon));
|
|
int received_port = (zframe_data (content) [0] << 8)
|
|
+ zframe_data (content) [1];
|
|
assert (received_port == port_nbr);
|
|
zframe_destroy (&content);
|
|
zbeacon_silence (service_beacon);
|
|
zstr_free (&ipaddress);
|
|
}
|
|
zbeacon_destroy (&client_beacon);
|
|
zbeacon_destroy (&service_beacon);
|
|
|
|
zbeacon_t *node1 = zbeacon_new (ctx, 5670);
|
|
assert (node1);
|
|
zbeacon_t *node2 = zbeacon_new (ctx, 5670);
|
|
assert (node2);
|
|
zbeacon_t *node3 = zbeacon_new (ctx, 5670);
|
|
assert (node3);
|
|
|
|
assert (*zbeacon_hostname (node1));
|
|
assert (*zbeacon_hostname (node2));
|
|
assert (*zbeacon_hostname (node3));
|
|
|
|
zbeacon_set_interval (node1, 250);
|
|
zbeacon_set_interval (node2, 250);
|
|
zbeacon_set_interval (node3, 250);
|
|
zbeacon_noecho (node1);
|
|
zbeacon_publish (node1, (byte *) "NODE/1", 6);
|
|
zbeacon_publish (node2, (byte *) "NODE/2", 6);
|
|
zbeacon_publish (node3, (byte *) "GARBAGE", 7);
|
|
zbeacon_subscribe (node1, (byte *) "NODE", 4);
|
|
|
|
// Poll on three API sockets at once
|
|
zpoller_t *poller = zpoller_new (
|
|
zbeacon_socket (node1),
|
|
zbeacon_socket (node2),
|
|
zbeacon_socket (node3), NULL);
|
|
assert (poller);
|
|
|
|
int64_t stop_at = zclock_mono () + 1000;
|
|
while (zclock_mono () < stop_at) {
|
|
long timeout = (long) (stop_at \- zclock_mono ());
|
|
if (timeout < 0)
|
|
timeout = 0;
|
|
void *which = zpoller_wait (poller, timeout * ZMQ_POLL_MSEC);
|
|
if (which) {
|
|
assert (which == zbeacon_socket (node1));
|
|
char *ipaddress, *beacon;
|
|
zstr_recvx (zbeacon_socket (node1), &ipaddress, &beacon, NULL);
|
|
assert (streq (beacon, "NODE/2"));
|
|
zstr_free (&ipaddress);
|
|
zstr_free (&beacon);
|
|
}
|
|
}
|
|
zpoller_destroy (&poller);
|
|
|
|
// Stop listening
|
|
zbeacon_unsubscribe (node1);
|
|
|
|
// Stop all node broadcasts
|
|
zbeacon_silence (node1);
|
|
zbeacon_silence (node2);
|
|
zbeacon_silence (node3);
|
|
|
|
// Destroy the test nodes
|
|
zbeacon_destroy (&node1);
|
|
zbeacon_destroy (&node2);
|
|
zbeacon_destroy (&node3);
|
|
|
|
zsock_destroy (&service);
|
|
zctx_destroy (&ctx);
|
|
.fi
|
|
.if n \{\
|
|
.RE
|
|
.\}
|
|
.sp
|
|
.SH "AUTHORS"
|
|
.sp
|
|
The czmq manual was written by the authors in the AUTHORS file\&.
|
|
.SH "RESOURCES"
|
|
.sp
|
|
Main web site: \m[blue]\fB\%\fR\m[]
|
|
.sp
|
|
Report bugs to the email <\m[blue]\fBzeromq\-dev@lists\&.zeromq\&.org\fR\m[]\&\s-2\u[1]\d\s+2>
|
|
.SH "COPYRIGHT"
|
|
.sp
|
|
Copyright (c) 1991\-2012 iMatix Corporation \-\- http://www\&.imatix\&.com Copyright other contributors as noted in the AUTHORS file\&. This file is part of CZMQ, the high\-level C binding for 0MQ: http://czmq\&.zeromq\&.org This Source Code Form is subject to the terms of the Mozilla Public License, v\&. 2\&.0\&. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla\&.org/MPL/2\&.0/\&. LICENSE included with the czmq distribution\&.
|
|
.SH "NOTES"
|
|
.IP " 1." 4
|
|
zeromq-dev@lists.zeromq.org
|
|
.RS 4
|
|
\%mailto:zeromq-dev@lists.zeromq.org
|
|
.RE
|
|
|