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+/*
+ * libzebra ZeroMQ bindings
+ * Copyright (C) 2015 David Lamparter
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _FRRZMQ_H
+#define _FRRZMQ_H
+
+#include "thread.h"
+#include <zmq.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* linking/packaging note: this is a separate library that needs to be
+ * linked into any daemon/library/module that wishes to use its
+ * functionality. The purpose of this is to encapsulate the libzmq
+ * dependency and not make libfrr/FRR itself depend on libzmq.
+ *
+ * libfrrzmq should be put in LDFLAGS/LIBADD *before* either libfrr or
+ * libzmq, and both of these should always be listed, e.g.
+ * foo_LDFLAGS = libfrrzmq.la libfrr.la $(ZEROMQ_LIBS)
+ */
+
+/* callback integration */
+struct cb_core {
+ struct thread *thread;
+ void *arg;
+
+ bool cancelled;
+
+ void (*cb_msg)(void *arg, void *zmqsock);
+ void (*cb_part)(void *arg, void *zmqsock, zmq_msg_t *msg,
+ unsigned partnum);
+ void (*cb_error)(void *arg, void *zmqsock);
+};
+
+struct frrzmq_cb {
+ void *zmqsock;
+ int fd;
+
+ bool in_cb; /* This context is in a read or write callback. */
+
+ struct cb_core read;
+ struct cb_core write;
+};
+
+/* libzmq's context
+ *
+ * this is mostly here as a convenience, it has IPv6 enabled but nothing
+ * else is tied to it; you can use a separate context without problems
+ */
+extern void *frrzmq_context;
+
+extern void frrzmq_init(void);
+extern void frrzmq_finish(void);
+
+#define _xref_zmq_a(type, f, d, call) \
+ ({ \
+ static const struct xref_threadsched _xref \
+ __attribute__((used)) = { \
+ .xref = XREF_INIT(XREFT_THREADSCHED, NULL, __func__), \
+ .funcname = #f, \
+ .dest = #d, \
+ .thread_type = THREAD_ ## type, \
+ }; \
+ XREF_LINK(_xref.xref); \
+ call; \
+ }) \
+ /* end */
+
+/* core event registration, one of these 2 macros should be used */
+#define frrzmq_thread_add_read_msg(m, f, e, a, z, d) \
+ _xref_zmq_a(READ, f, d, \
+ _frrzmq_thread_add_read(&_xref, m, f, NULL, e, a, z, d))
+
+#define frrzmq_thread_add_read_part(m, f, e, a, z, d) \
+ _xref_zmq_a(READ, f, d, \
+ _frrzmq_thread_add_read(&_xref, m, NULL, f, e, a, z, d))
+
+#define frrzmq_thread_add_write_msg(m, f, e, a, z, d) \
+ _xref_zmq_a(WRITE, f, d, \
+ _frrzmq_thread_add_write(&_xref, m, f, e, a, z, d))
+
+struct cb_core;
+struct frrzmq_cb;
+
+/* Set up a POLLIN or POLLOUT notification to be called from the libfrr main
+ * loop. This has the following properties:
+ *
+ * - since ZeroMQ works with edge triggered notifications, it will loop and
+ * dispatch as many events as ZeroMQ has pending at the time libfrr calls
+ * into this code
+ * - due to this looping (which means it non-single-issue), the callback is
+ * also persistent. Do _NOT_ re-register the event inside of your
+ * callback function.
+ * - either msgfunc or partfunc will be called (only one can be specified)
+ * - msgfunc is called once for each incoming message
+ * - if partfunc is specified, the message is read and partfunc is called
+ * for each ZeroMQ multi-part subpart. Note that you can't send replies
+ * before all parts have been read because that violates the ZeroMQ FSM.
+ * - write version doesn't allow for partial callback, you must handle the
+ * whole message (all parts) in msgfunc callback
+ * - you can safely cancel the callback from within itself
+ * - installing a callback will check for pending events (ZMQ_EVENTS) and
+ * may schedule the event to run as soon as libfrr is back in its main
+ * loop.
+ */
+extern int _frrzmq_thread_add_read(
+ const struct xref_threadsched *xref, struct thread_master *master,
+ void (*msgfunc)(void *arg, void *zmqsock),
+ void (*partfunc)(void *arg, void *zmqsock, zmq_msg_t *msg,
+ unsigned partnum),
+ void (*errfunc)(void *arg, void *zmqsock), void *arg, void *zmqsock,
+ struct frrzmq_cb **cb);
+extern int _frrzmq_thread_add_write(
+ const struct xref_threadsched *xref, struct thread_master *master,
+ void (*msgfunc)(void *arg, void *zmqsock),
+ void (*errfunc)(void *arg, void *zmqsock), void *arg, void *zmqsock,
+ struct frrzmq_cb **cb);
+
+extern void frrzmq_thread_cancel(struct frrzmq_cb **cb, struct cb_core *core);
+
+/*
+ * http://api.zeromq.org/4-2:zmq-getsockopt#toc10
+ *
+ * As the descriptor is edge triggered, applications must update the state of
+ * ZMQ_EVENTS after each invocation of zmq_send or zmq_recv.To be more explicit:
+ * after calling zmq_send the socket may become readable (and vice versa)
+ * without triggering a read event on the file descriptor.
+ */
+extern void frrzmq_check_events(struct frrzmq_cb **cbp, struct cb_core *core,
+ int event);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _FRRZMQ_H */