io: introduce a network socket listener API

The existing QIOChannelSocket class provides the ability to
listen on a single socket at a time. This patch introduces
a QIONetListener class that provides a higher level API
concept around listening for network services, allowing
for listening on multiple sockets.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrange 2016-07-19 13:37:51 +01:00
parent 5705b536b5
commit 530473924d
3 changed files with 482 additions and 0 deletions

174
include/io/net-listener.h Normal file
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@ -0,0 +1,174 @@
/*
* QEMU network listener
*
* Copyright (c) 2016-2017 Red Hat, Inc.
*
* 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; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef QIO_NET_LISTENER_H
#define QIO_NET_LISTENER_H
#include "io/channel-socket.h"
#define TYPE_QIO_NET_LISTENER "qio-net-listener"
#define QIO_NET_LISTENER(obj) \
OBJECT_CHECK(QIONetListener, (obj), TYPE_QIO_NET_LISTENER)
#define QIO_NET_LISTENER_CLASS(klass) \
OBJECT_CLASS_CHECK(QIONetListenerClass, klass, TYPE_QIO_NET_LISTENER)
#define QIO_NET_LISTENER_GET_CLASS(obj) \
OBJECT_GET_CLASS(QIONetListenerClass, obj, TYPE_QIO_NET_LISTENER)
typedef struct QIONetListener QIONetListener;
typedef struct QIONetListenerClass QIONetListenerClass;
typedef void (*QIONetListenerClientFunc)(QIONetListener *listener,
QIOChannelSocket *sioc,
gpointer data);
/**
* QIONetListener:
*
* The QIONetListener object encapsulates the management of a
* listening socket. It is able to listen on multiple sockets
* concurrently, to deal with the scenario where IPv4 / IPv6
* needs separate sockets, or there is a need to listen on a
* subset of interface IP addresses, instead of the wildcard
* address.
*/
struct QIONetListener {
Object parent;
char *name;
QIOChannelSocket **sioc;
gulong *io_tag;
size_t nsioc;
bool connected;
QIONetListenerClientFunc io_func;
gpointer io_data;
GDestroyNotify io_notify;
};
struct QIONetListenerClass {
ObjectClass parent;
};
/**
* qio_net_listener_new:
*
* Create a new network listener service, which is not
* listening on any sockets initially.
*
* Returns: the new listener
*/
QIONetListener *qio_net_listener_new(void);
/**
* qio_net_listener_set_name:
* @listener: the network listener object
* @name: the listener name
*
* Set the name of the listener. This is used as a debugging
* aid, to set names on any GSource instances associated
* with the listener
*/
void qio_net_listener_set_name(QIONetListener *listener,
const char *name);
/**
* qio_net_listener_open_sync:
* @listener: the network listener object
* @addr: the address to listen on
* @errp: pointer to a NULL initialized error object
*
* Synchronously open a listening connection on all
* addresses associated with @addr. This method may
* also be invoked multiple times, in order to have a
* single listener on multiple distinct addresses.
*/
int qio_net_listener_open_sync(QIONetListener *listener,
SocketAddress *addr,
Error **errp);
/**
* qio_net_listener_add:
* @listener: the network listener object
* @sioc: the socket I/O channel
*
* Associate a listening socket I/O channel with the
* listener. The listener will acquire a new reference
* on @sioc, so the caller should release its own reference
* if it no longer requires the object.
*/
void qio_net_listener_add(QIONetListener *listener,
QIOChannelSocket *sioc);
/**
* qio_net_listener_set_client_func:
* @listener: the network listener object
* @func: the callback function
* @data: opaque data to pass to @func
* @notify: callback to free @data
*
* Register @func to be invoked whenever a new client
* connects to the listener. @func will be invoked
* passing in the QIOChannelSocket instance for the
* client.
*/
void qio_net_listener_set_client_func(QIONetListener *listener,
QIONetListenerClientFunc func,
gpointer data,
GDestroyNotify notify);
/**
* qio_net_listener_wait_client:
* @listener: the network listener object
*
* Block execution of the caller until a new client arrives
* on one of the listening sockets. If there was previously
* a callback registered with qio_net_listener_set_client_func
* it will be temporarily disabled, and re-enabled afterwards.
*
* Returns: the new client socket
*/
QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener);
/**
* qio_net_listener_disconnect:
* @listener: the network listener object
*
* Disconnect the listener, removing all I/O callback
* watches and closing the socket channels.
*/
void qio_net_listener_disconnect(QIONetListener *listener);
/**
* qio_net_listener_is_connected:
* @listener: the network listener object
*
* Determine if the listener is connected to any socket
* channels
*
* Returns: true if connected, false otherwise
*/
bool qio_net_listener_is_connected(QIONetListener *listener);
#endif /* QIO_NET_LISTENER_H */

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@ -8,4 +8,5 @@ io-obj-y += channel-watch.o
io-obj-y += channel-websock.o
io-obj-y += channel-util.o
io-obj-y += dns-resolver.o
io-obj-y += net-listener.o
io-obj-y += task.o

307
io/net-listener.c Normal file
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@ -0,0 +1,307 @@
/*
* QEMU network listener
*
* Copyright (c) 2016-2017 Red Hat, Inc.
*
* 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; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "io/net-listener.h"
#include "io/dns-resolver.h"
#include "qapi/error.h"
QIONetListener *qio_net_listener_new(void)
{
QIONetListener *ret;
ret = QIO_NET_LISTENER(object_new(TYPE_QIO_NET_LISTENER));
return ret;
}
void qio_net_listener_set_name(QIONetListener *listener,
const char *name)
{
g_free(listener->name);
listener->name = g_strdup(name);
}
static gboolean qio_net_listener_channel_func(QIOChannel *ioc,
GIOCondition condition,
gpointer opaque)
{
QIONetListener *listener = QIO_NET_LISTENER(opaque);
QIOChannelSocket *sioc;
sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
NULL);
if (!sioc) {
return TRUE;
}
if (listener->io_func) {
listener->io_func(listener, sioc, listener->io_data);
}
object_unref(OBJECT(sioc));
return TRUE;
}
int qio_net_listener_open_sync(QIONetListener *listener,
SocketAddress *addr,
Error **errp)
{
QIODNSResolver *resolver = qio_dns_resolver_get_instance();
SocketAddress **resaddrs;
size_t nresaddrs;
size_t i;
Error *err = NULL;
bool success = false;
if (qio_dns_resolver_lookup_sync(resolver,
addr,
&nresaddrs,
&resaddrs,
errp) < 0) {
return -1;
}
for (i = 0; i < nresaddrs; i++) {
QIOChannelSocket *sioc = qio_channel_socket_new();
if (qio_channel_socket_listen_sync(sioc, resaddrs[i],
err ? NULL : &err) == 0) {
success = true;
qio_net_listener_add(listener, sioc);
}
qapi_free_SocketAddress(resaddrs[i]);
object_unref(OBJECT(sioc));
}
g_free(resaddrs);
if (success) {
error_free(err);
return 0;
} else {
error_propagate(errp, err);
return -1;
}
}
void qio_net_listener_add(QIONetListener *listener,
QIOChannelSocket *sioc)
{
if (listener->name) {
char *name = g_strdup_printf("%s-listen", listener->name);
qio_channel_set_name(QIO_CHANNEL(sioc), name);
g_free(name);
}
listener->sioc = g_renew(QIOChannelSocket *, listener->sioc,
listener->nsioc + 1);
listener->io_tag = g_renew(gulong, listener->io_tag, listener->nsioc + 1);
listener->sioc[listener->nsioc] = sioc;
listener->io_tag[listener->nsioc] = 0;
object_ref(OBJECT(sioc));
listener->connected = true;
if (listener->io_func != NULL) {
object_ref(OBJECT(listener));
listener->io_tag[listener->nsioc] = qio_channel_add_watch(
QIO_CHANNEL(listener->sioc[listener->nsioc]), G_IO_IN,
qio_net_listener_channel_func,
listener, (GDestroyNotify)object_unref);
}
listener->nsioc++;
}
void qio_net_listener_set_client_func(QIONetListener *listener,
QIONetListenerClientFunc func,
gpointer data,
GDestroyNotify notify)
{
size_t i;
if (listener->io_notify) {
listener->io_notify(listener->io_data);
}
listener->io_func = func;
listener->io_data = data;
listener->io_notify = notify;
for (i = 0; i < listener->nsioc; i++) {
if (listener->io_tag[i]) {
g_source_remove(listener->io_tag[i]);
listener->io_tag[i] = 0;
}
}
if (listener->io_func != NULL) {
for (i = 0; i < listener->nsioc; i++) {
object_ref(OBJECT(listener));
listener->io_tag[i] = qio_channel_add_watch(
QIO_CHANNEL(listener->sioc[i]), G_IO_IN,
qio_net_listener_channel_func,
listener, (GDestroyNotify)object_unref);
}
}
}
struct QIONetListenerClientWaitData {
QIOChannelSocket *sioc;
GMainLoop *loop;
};
static gboolean qio_net_listener_wait_client_func(QIOChannel *ioc,
GIOCondition condition,
gpointer opaque)
{
struct QIONetListenerClientWaitData *data = opaque;
QIOChannelSocket *sioc;
sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
NULL);
if (!sioc) {
return TRUE;
}
if (data->sioc) {
object_unref(OBJECT(sioc));
} else {
data->sioc = sioc;
g_main_loop_quit(data->loop);
}
return TRUE;
}
QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
{
GMainContext *ctxt = g_main_context_new();
GMainLoop *loop = g_main_loop_new(ctxt, TRUE);
GSource **sources;
struct QIONetListenerClientWaitData data = {
.sioc = NULL,
.loop = loop
};
size_t i;
for (i = 0; i < listener->nsioc; i++) {
if (listener->io_tag[i]) {
g_source_remove(listener->io_tag[i]);
listener->io_tag[i] = 0;
}
}
sources = g_new0(GSource *, listener->nsioc);
for (i = 0; i < listener->nsioc; i++) {
sources[i] = qio_channel_create_watch(QIO_CHANNEL(listener->sioc[i]),
G_IO_IN);
g_source_set_callback(sources[i],
(GSourceFunc)qio_net_listener_wait_client_func,
&data,
NULL);
g_source_attach(sources[i], ctxt);
}
g_main_loop_run(loop);
for (i = 0; i < listener->nsioc; i++) {
g_source_unref(sources[i]);
}
g_main_loop_unref(loop);
g_main_context_unref(ctxt);
if (listener->io_func != NULL) {
for (i = 0; i < listener->nsioc; i++) {
object_ref(OBJECT(listener));
listener->io_tag[i] = qio_channel_add_watch(
QIO_CHANNEL(listener->sioc[i]), G_IO_IN,
qio_net_listener_channel_func,
listener, (GDestroyNotify)object_unref);
}
}
return data.sioc;
}
void qio_net_listener_disconnect(QIONetListener *listener)
{
size_t i;
if (!listener->connected) {
return;
}
for (i = 0; i < listener->nsioc; i++) {
if (listener->io_tag[i]) {
g_source_remove(listener->io_tag[i]);
listener->io_tag[i] = 0;
}
qio_channel_close(QIO_CHANNEL(listener->sioc[i]), NULL);
}
listener->connected = false;
}
bool qio_net_listener_is_connected(QIONetListener *listener)
{
return listener->connected;
}
static void qio_net_listener_finalize(Object *obj)
{
QIONetListener *listener = QIO_NET_LISTENER(obj);
size_t i;
qio_net_listener_disconnect(listener);
for (i = 0; i < listener->nsioc; i++) {
object_unref(OBJECT(listener->sioc[i]));
}
g_free(listener->io_tag);
g_free(listener->sioc);
g_free(listener->name);
}
static const TypeInfo qio_net_listener_info = {
.parent = TYPE_OBJECT,
.name = TYPE_QIO_NET_LISTENER,
.instance_size = sizeof(QIONetListener),
.instance_finalize = qio_net_listener_finalize,
.class_size = sizeof(QIONetListenerClass),
};
static void qio_net_listener_register_types(void)
{
type_register_static(&qio_net_listener_info);
}
type_init(qio_net_listener_register_types);