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Diffstat (limited to '')
| -rw-r--r-- | lib/frr_zmq.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/lib/frr_zmq.h b/lib/frr_zmq.h new file mode 100644 index 0000000..b3be78c --- /dev/null +++ b/lib/frr_zmq.h @@ -0,0 +1,154 @@ +/* + * 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 */ |