Implement common keepalive handling

These APIs are used by both client and server RPC layer to handle
processing of keepalive messages.
This commit is contained in:
Jiri Denemark 2011-09-22 13:40:00 +02:00
parent 4acd358a76
commit 71b779a1ad
5 changed files with 519 additions and 1 deletions

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@ -73,6 +73,7 @@ src/qemu/qemu_monitor_text.c
src/qemu/qemu_process.c
src/remote/remote_client_bodies.h
src/remote/remote_driver.c
src/rpc/virkeepalive.c
src/rpc/virnetclient.c
src/rpc/virnetclientprogram.c
src/rpc/virnetclientstream.c

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@ -1387,7 +1387,8 @@ libvirt_net_rpc_la_SOURCES = \
rpc/virnetprotocol.h rpc/virnetprotocol.c \
rpc/virnetsocket.h rpc/virnetsocket.c \
rpc/virnettlscontext.h rpc/virnettlscontext.c \
rpc/virkeepaliveprotocol.h rpc/virkeepaliveprotocol.c
rpc/virkeepaliveprotocol.h rpc/virkeepaliveprotocol.c \
rpc/virkeepalive.h rpc/virkeepalive.c
if HAVE_SASL
libvirt_net_rpc_la_SOURCES += \
rpc/virnetsaslcontext.h rpc/virnetsaslcontext.c

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@ -72,6 +72,18 @@ provider libvirt {
probe rpc_tls_session_handshake_fail(void *sess);
# file: src/rpc/virkeepalive.c
# prefix: rpc
probe rpc_keepalive_new(void *ka, void *client, int refs);
probe rpc_keepalive_ref(void *ka, void *client, int refs);
probe rpc_keepalive_free(void *ka, void *client, int refs);
probe rpc_keepalive_start(void *ka, void *client, int interval, int count);
probe rpc_keepalive_stop(void *ka, void *client);
probe rpc_keepalive_send(void *ka, void *client, int prog, int vers, int proc);
probe rpc_keepalive_received(void *ka, void *client, int prog, int vers, int proc);
probe rpc_keepalive_timeout(void *ka, void *client, int coundToDeath, int idle);
# file: src/qemu/qemu_monitor.c
# prefix: qemu
# binary: libvirtd

448
src/rpc/virkeepalive.c Normal file
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@ -0,0 +1,448 @@
/*
* virkeepalive.c: keepalive handling
*
* Copyright (C) 2011 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Jiri Denemark <jdenemar@redhat.com>
*/
#include <config.h>
#include "memory.h"
#include "threads.h"
#include "virfile.h"
#include "logging.h"
#include "util.h"
#include "virterror_internal.h"
#include "virnetsocket.h"
#include "virkeepaliveprotocol.h"
#include "virkeepalive.h"
#define VIR_FROM_THIS VIR_FROM_RPC
#define virNetError(code, ...) \
virReportErrorHelper(VIR_FROM_THIS, code, __FILE__, \
__FUNCTION__, __LINE__, __VA_ARGS__)
struct _virKeepAlive {
int refs;
virMutex lock;
int interval;
unsigned int count;
unsigned int countToDeath;
time_t lastPacketReceived;
int timer;
virNetMessagePtr response;
int responseTimer;
virKeepAliveSendFunc sendCB;
virKeepAliveDeadFunc deadCB;
virKeepAliveFreeFunc freeCB;
void *client;
};
static void
virKeepAliveLock(virKeepAlivePtr ka)
{
virMutexLock(&ka->lock);
}
static void
virKeepAliveUnlock(virKeepAlivePtr ka)
{
virMutexUnlock(&ka->lock);
}
static virNetMessagePtr
virKeepAliveMessage(int proc)
{
virNetMessagePtr msg;
if (!(msg = virNetMessageNew(false)))
return NULL;
msg->header.prog = KEEPALIVE_PROGRAM;
msg->header.vers = KEEPALIVE_PROTOCOL_VERSION;
msg->header.type = VIR_NET_MESSAGE;
msg->header.proc = proc;
if (virNetMessageEncodeHeader(msg) < 0 ||
virNetMessageEncodePayloadEmpty(msg) < 0) {
virNetMessageFree(msg);
return NULL;
}
return msg;
}
static void
virKeepAliveSend(virKeepAlivePtr ka, virNetMessagePtr msg)
{
const char *proc = NULL;
void *client = ka->client;
virKeepAliveSendFunc sendCB = ka->sendCB;
switch (msg->header.proc) {
case KEEPALIVE_PROC_PING:
proc = "request";
break;
case KEEPALIVE_PROC_PONG:
proc = "response";
break;
}
if (!proc) {
VIR_WARN("Refusing to send unknown keepalive message: %d",
msg->header.proc);
virNetMessageFree(msg);
return;
}
VIR_DEBUG("Sending keepalive %s to client %p", proc, ka->client);
PROBE(RPC_KEEPALIVE_SEND,
"ka=%p client=%p prog=%d vers=%d proc=%d",
ka, ka->client, msg->header.prog, msg->header.vers, msg->header.proc);
ka->refs++;
virKeepAliveUnlock(ka);
if (sendCB(client, msg) < 0) {
VIR_WARN("Failed to send keepalive %s to client %p", proc, client);
virNetMessageFree(msg);
}
virKeepAliveLock(ka);
ka->refs--;
}
static void
virKeepAliveScheduleResponse(virKeepAlivePtr ka)
{
if (ka->responseTimer == -1)
return;
VIR_DEBUG("Scheduling keepalive response to client %p", ka->client);
if (!ka->response &&
!(ka->response = virKeepAliveMessage(KEEPALIVE_PROC_PONG))) {
VIR_WARN("Failed to generate keepalive response");
return;
}
virEventUpdateTimeout(ka->responseTimer, 0);
}
static void
virKeepAliveTimer(int timer ATTRIBUTE_UNUSED, void *opaque)
{
virKeepAlivePtr ka = opaque;
time_t now = time(NULL);
virKeepAliveLock(ka);
PROBE(RPC_KEEPALIVE_TIMEOUT,
"ka=%p client=%p countToDeath=%d idle=%d",
ka, ka->client, ka->countToDeath,
(int) (now - ka->lastPacketReceived));
if (now - ka->lastPacketReceived < ka->interval - 1) {
int timeout = ka->interval - (now - ka->lastPacketReceived);
virEventUpdateTimeout(ka->timer, timeout * 1000);
goto cleanup;
}
if (ka->countToDeath == 0) {
virKeepAliveDeadFunc deadCB = ka->deadCB;
void *client = ka->client;
VIR_WARN("No response from client %p after %d keepalive messages in"
" %d seconds",
ka->client,
ka->count,
(int) (now - ka->lastPacketReceived));
ka->refs++;
virKeepAliveUnlock(ka);
deadCB(client);
virKeepAliveLock(ka);
ka->refs--;
} else {
virNetMessagePtr msg;
ka->countToDeath--;
if (!(msg = virKeepAliveMessage(KEEPALIVE_PROC_PING)))
VIR_WARN("Failed to generate keepalive request");
else
virKeepAliveSend(ka, msg);
virEventUpdateTimeout(ka->timer, ka->interval * 1000);
}
cleanup:
virKeepAliveUnlock(ka);
}
static void
virKeepAliveResponseTimer(int timer ATTRIBUTE_UNUSED, void *opaque)
{
virKeepAlivePtr ka = opaque;
virNetMessagePtr msg;
virKeepAliveLock(ka);
VIR_DEBUG("ka=%p, client=%p, response=%p",
ka, ka->client, ka->response);
if (ka->response) {
msg = ka->response;
ka->response = NULL;
virKeepAliveSend(ka, msg);
}
virEventUpdateTimeout(ka->responseTimer, ka->response ? 0 : -1);
virKeepAliveUnlock(ka);
}
static void
virKeepAliveTimerFree(void *opaque)
{
virKeepAliveFree(opaque);
}
virKeepAlivePtr
virKeepAliveNew(int interval,
unsigned int count,
void *client,
virKeepAliveSendFunc sendCB,
virKeepAliveDeadFunc deadCB,
virKeepAliveFreeFunc freeCB)
{
virKeepAlivePtr ka;
VIR_DEBUG("client=%p, interval=%d, count=%u", client, interval, count);
if (VIR_ALLOC(ka) < 0) {
virReportOOMError();
return NULL;
}
if (virMutexInit(&ka->lock) < 0) {
VIR_FREE(ka);
return NULL;
}
ka->refs = 1;
ka->interval = interval;
ka->count = count;
ka->countToDeath = count;
ka->timer = -1;
ka->client = client;
ka->sendCB = sendCB;
ka->deadCB = deadCB;
ka->freeCB = freeCB;
ka->responseTimer = virEventAddTimeout(-1, virKeepAliveResponseTimer,
ka, virKeepAliveTimerFree);
if (ka->responseTimer < 0) {
virKeepAliveFree(ka);
return NULL;
}
/* the timer now has a reference to ka */
ka->refs++;
PROBE(RPC_KEEPALIVE_NEW,
"ka=%p client=%p refs=%d",
ka, ka->client, ka->refs);
return ka;
}
void
virKeepAliveRef(virKeepAlivePtr ka)
{
virKeepAliveLock(ka);
ka->refs++;
PROBE(RPC_KEEPALIVE_REF,
"ka=%p client=%p refs=%d",
ka, ka->client, ka->refs);
virKeepAliveUnlock(ka);
}
void
virKeepAliveFree(virKeepAlivePtr ka)
{
if (!ka)
return;
virKeepAliveLock(ka);
PROBE(RPC_KEEPALIVE_FREE,
"ka=%p client=%p refs=%d",
ka, ka->client, ka->refs);
if (--ka->refs > 0) {
virKeepAliveUnlock(ka);
return;
}
virMutexDestroy(&ka->lock);
ka->freeCB(ka->client);
VIR_FREE(ka);
}
int
virKeepAliveStart(virKeepAlivePtr ka,
int interval,
unsigned int count)
{
int ret = -1;
time_t delay;
int timeout;
virKeepAliveLock(ka);
if (ka->timer >= 0) {
VIR_DEBUG("Keepalive messages already enabled");
ret = 0;
goto cleanup;
}
if (interval > 0) {
if (ka->interval > 0) {
virNetError(VIR_ERR_INTERNAL_ERROR, "%s",
_("keepalive interval already set"));
goto cleanup;
}
ka->interval = interval;
ka->count = count;
ka->countToDeath = count;
}
if (ka->interval <= 0) {
VIR_DEBUG("Keepalive messages disabled by configuration");
ret = 0;
goto cleanup;
}
PROBE(RPC_KEEPALIVE_START,
"ka=%p client=%p interval=%d count=%u",
ka, ka->client, interval, count);
delay = time(NULL) - ka->lastPacketReceived;
if (delay > ka->interval)
timeout = 0;
else
timeout = ka->interval - delay;
ka->timer = virEventAddTimeout(timeout * 1000, virKeepAliveTimer,
ka, virKeepAliveTimerFree);
if (ka->timer < 0)
goto cleanup;
/* the timer now has another reference to this object */
ka->refs++;
ret = 0;
cleanup:
virKeepAliveUnlock(ka);
return ret;
}
void
virKeepAliveStop(virKeepAlivePtr ka)
{
virKeepAliveLock(ka);
PROBE(RPC_KEEPALIVE_STOP,
"ka=%p client=%p",
ka, ka->client);
if (ka->timer > 0) {
virEventRemoveTimeout(ka->timer);
ka->timer = -1;
}
if (ka->responseTimer > 0) {
virEventRemoveTimeout(ka->responseTimer);
ka->responseTimer = -1;
}
virNetMessageFree(ka->response);
ka->response = NULL;
virKeepAliveUnlock(ka);
}
bool
virKeepAliveCheckMessage(virKeepAlivePtr ka,
virNetMessagePtr msg)
{
bool ret = false;
VIR_DEBUG("ka=%p, client=%p, msg=%p",
ka, ka ? ka->client : "(null)", msg);
if (!ka)
return false;
virKeepAliveLock(ka);
ka->countToDeath = ka->count;
ka->lastPacketReceived = time(NULL);
if (msg->header.prog == KEEPALIVE_PROGRAM &&
msg->header.vers == KEEPALIVE_PROTOCOL_VERSION &&
msg->header.type == VIR_NET_MESSAGE) {
PROBE(RPC_KEEPALIVE_RECEIVED,
"ka=%p client=%p prog=%d vers=%d proc=%d",
ka, ka->client, msg->header.prog,
msg->header.vers, msg->header.proc);
ret = true;
switch (msg->header.proc) {
case KEEPALIVE_PROC_PING:
VIR_DEBUG("Got keepalive request from client %p", ka->client);
virKeepAliveScheduleResponse(ka);
break;
case KEEPALIVE_PROC_PONG:
VIR_DEBUG("Got keepalive response from client %p", ka->client);
break;
default:
VIR_DEBUG("Ignoring unknown keepalive message %d from client %p",
msg->header.proc, ka->client);
}
}
if (ka->timer >= 0)
virEventUpdateTimeout(ka->timer, ka->interval * 1000);
virKeepAliveUnlock(ka);
return ret;
}

56
src/rpc/virkeepalive.h Normal file
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@ -0,0 +1,56 @@
/*
* virkeepalive.h: keepalive handling
*
* Copyright (C) 2011 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Jiri Denemark <jdenemar@redhat.com>
*/
#ifndef __VIR_KEEPALIVE_H__
# define __VIR_KEEPALIVE_H__
# include "virnetmessage.h"
typedef int (*virKeepAliveSendFunc)(void *client, virNetMessagePtr msg);
typedef void (*virKeepAliveDeadFunc)(void *client);
typedef void (*virKeepAliveFreeFunc)(void *client);
typedef struct _virKeepAlive virKeepAlive;
typedef virKeepAlive *virKeepAlivePtr;
virKeepAlivePtr virKeepAliveNew(int interval,
unsigned int count,
void *client,
virKeepAliveSendFunc sendCB,
virKeepAliveDeadFunc deadCB,
virKeepAliveFreeFunc freeCB)
ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4)
ATTRIBUTE_NONNULL(5) ATTRIBUTE_NONNULL(6);
void virKeepAliveRef(virKeepAlivePtr ka);
void virKeepAliveFree(virKeepAlivePtr ka);
int virKeepAliveStart(virKeepAlivePtr ka,
int interval,
unsigned int count);
void virKeepAliveStop(virKeepAlivePtr ka);
bool virKeepAliveCheckMessage(virKeepAlivePtr ka,
virNetMessagePtr msg);
#endif /* __VIR_KEEPALIVE_H__ */