[libvirt] [PATCH v3 05/13] Implement keepalive protocol in libvirt daemon
Jiri Denemark
jdenemar at redhat.com
Wed Oct 12 05:16:23 UTC 2011
---
Notes:
Version 3:
- keepalive_supported configuration option can be used to refuse
connections from clients that do not support keepalive protocol
- explain what keepalive_interval = -1 means
- start up the keepalive protocol when a client asks if we support
it (clients without keepalive support do not ask for it)
- add filters to the end of the list so that they are processed
in the same order they were added (and not in reverse order); as
a result of that the keepalive filter will always be the first one
and libvirtd will not send keepalive requests while client is
sending stream packets
Version 2:
- no change
daemon/libvirtd.aug | 5 ++
daemon/libvirtd.c | 15 +++++
daemon/libvirtd.conf | 22 +++++++
daemon/libvirtd.h | 1 +
daemon/remote.c | 48 ++++++++++++++-
src/libvirt_private.syms | 2 +
src/remote/remote_protocol.x | 2 +-
src/rpc/virnetserver.c | 22 +++++++
src/rpc/virnetserver.h | 5 ++
src/rpc/virnetserverclient.c | 143 ++++++++++++++++++++++++++++++++++++++---
src/rpc/virnetserverclient.h | 7 ++
11 files changed, 259 insertions(+), 13 deletions(-)
diff --git a/daemon/libvirtd.aug b/daemon/libvirtd.aug
index ce00db5..9d78bd7 100644
--- a/daemon/libvirtd.aug
+++ b/daemon/libvirtd.aug
@@ -66,6 +66,10 @@ module Libvirtd =
let auditing_entry = int_entry "audit_level"
| bool_entry "audit_logging"
+ let keepalive_entry = int_entry "keepalive_interval"
+ | int_entry "keepalive_count"
+ | bool_entry "keepalive_required"
+
(* Each enty in the config is one of the following three ... *)
let entry = network_entry
| sock_acl_entry
@@ -75,6 +79,7 @@ module Libvirtd =
| processing_entry
| logging_entry
| auditing_entry
+ | keepalive_entry
let comment = [ label "#comment" . del /#[ \t]*/ "# " . store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
let empty = [ label "#empty" . eol ]
diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index d1bc3dd..13fba64 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -146,6 +146,10 @@ struct daemonConfig {
int audit_level;
int audit_logging;
+
+ int keepalive_interval;
+ unsigned int keepalive_count;
+ int keepalive_required;
};
enum {
@@ -899,6 +903,10 @@ daemonConfigNew(bool privileged ATTRIBUTE_UNUSED)
data->audit_level = 1;
data->audit_logging = 0;
+ data->keepalive_interval = 5;
+ data->keepalive_count = 5;
+ data->keepalive_required = 0;
+
localhost = virGetHostname(NULL);
if (localhost == NULL) {
/* we couldn't resolve the hostname; assume that we are
@@ -1062,6 +1070,10 @@ daemonConfigLoad(struct daemonConfig *data,
GET_CONF_STR (conf, filename, log_outputs);
GET_CONF_INT (conf, filename, log_buffer_size);
+ GET_CONF_INT (conf, filename, keepalive_interval);
+ GET_CONF_INT (conf, filename, keepalive_count);
+ GET_CONF_INT (conf, filename, keepalive_required);
+
virConfFree (conf);
return 0;
@@ -1452,6 +1464,9 @@ int main(int argc, char **argv) {
config->max_workers,
config->prio_workers,
config->max_clients,
+ config->keepalive_interval,
+ config->keepalive_count,
+ !!config->keepalive_required,
config->mdns_adv ? config->mdns_name : NULL,
use_polkit_dbus,
remoteClientInitHook))) {
diff --git a/daemon/libvirtd.conf b/daemon/libvirtd.conf
index da3983e..5d1e011 100644
--- a/daemon/libvirtd.conf
+++ b/daemon/libvirtd.conf
@@ -366,3 +366,25 @@
# it with the output of the 'uuidgen' command and then
# uncomment this entry
#host_uuid = "00000000-0000-0000-0000-000000000000"
+
+###################################################################
+# Keepalive protocol:
+# This allows libvirtd to detect broken client connections or even
+# dead client. A keepalive message is sent to a client after
+# keepalive_interval seconds of inactivity to check if the client is
+# still responding; keepalive_count is a maximum number of keepalive
+# messages that are allowed to be sent to the client without getting
+# any response before the connection is considered broken. In other
+# words, the connection is automatically closed approximately after
+# keepalive_interval * (keepalive_count + 1) seconds since the last
+# message received from the client. If keepalive_interval is set to
+# -1, libvirtd will never send keepalive requests; however clients
+# can still send them and the deamon will send responses.
+#
+#keepalive_interval = 5
+#keepalive_count = 5
+#
+# If set to 1, libvirtd will refuse to talk to clients that do not
+# support keepalive protocol. Defaults to 0.
+#
+#keepalive_required = 1
diff --git a/daemon/libvirtd.h b/daemon/libvirtd.h
index ecb7374..e02d7b8 100644
--- a/daemon/libvirtd.h
+++ b/daemon/libvirtd.h
@@ -62,6 +62,7 @@ struct daemonClientPrivate {
virConnectPtr conn;
daemonClientStreamPtr streams;
+ bool keepalive_supported;
};
# if HAVE_SASL
diff --git a/daemon/remote.c b/daemon/remote.c
index 550bed4..b33c619 100644
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -533,7 +533,7 @@ int remoteClientInitHook(virNetServerPtr srv ATTRIBUTE_UNUSED,
/*----- Functions. -----*/
static int
-remoteDispatchOpen(virNetServerPtr server ATTRIBUTE_UNUSED,
+remoteDispatchOpen(virNetServerPtr server,
virNetServerClientPtr client,
virNetMessageHeaderPtr hdr ATTRIBUTE_UNUSED,
virNetMessageErrorPtr rerr,
@@ -552,6 +552,12 @@ remoteDispatchOpen(virNetServerPtr server ATTRIBUTE_UNUSED,
goto cleanup;
}
+ if (virNetServerKeepAliveRequired(server) && !priv->keepalive_supported) {
+ virNetError(VIR_ERR_OPERATION_FAILED, "%s",
+ _("keepalive support is required to connect"));
+ goto cleanup;
+ }
+
name = args->name ? *args->name : NULL;
/* If this connection arrived on a readonly socket, force
@@ -3124,6 +3130,46 @@ cleanup:
}
+static int
+remoteDispatchSupportsFeature(virNetServerPtr server ATTRIBUTE_UNUSED,
+ virNetServerClientPtr client,
+ virNetMessageHeaderPtr hdr ATTRIBUTE_UNUSED,
+ virNetMessageErrorPtr rerr,
+ remote_supports_feature_args *args,
+ remote_supports_feature_ret *ret)
+{
+ int rv = -1;
+ int supported;
+ struct daemonClientPrivate *priv =
+ virNetServerClientGetPrivateData(client);
+
+ if (args->feature == VIR_DRV_FEATURE_PROGRAM_KEEPALIVE) {
+ if (virNetServerClientStartKeepAlive(client) < 0)
+ goto cleanup;
+ supported = 1;
+ goto done;
+ }
+
+ if (!priv->conn) {
+ virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("connection not open"));
+ goto cleanup;
+ }
+
+ if ((supported = virDrvSupportsFeature(priv->conn, args->feature)) < 0)
+ goto cleanup;
+
+done:
+ ret->supported = supported;
+ rv = 0;
+
+cleanup:
+ if (rv < 0)
+ virNetMessageSaveError(rerr);
+ return rv;
+}
+
+
+
/*----- Helpers. -----*/
/* get_nonnull_domain and get_nonnull_network turn an on-wire
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 11ff705..fcad1f4 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1187,6 +1187,7 @@ virNetServerAutoShutdown;
virNetServerClose;
virNetServerFree;
virNetServerIsPrivileged;
+virNetServerKeepAliveRequired;
virNetServerNew;
virNetServerQuit;
virNetServerRef;
@@ -1219,6 +1220,7 @@ virNetServerClientSendMessage;
virNetServerClientSetCloseHook;
virNetServerClientSetIdentity;
virNetServerClientSetPrivateData;
+virNetServerClientStartKeepAlive;
# virnetserverprogram.h
diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x
index f95253e..8a29b18 100644
--- a/src/remote/remote_protocol.x
+++ b/src/remote/remote_protocol.x
@@ -2340,7 +2340,7 @@ enum remote_procedure {
REMOTE_PROC_DOMAIN_GET_SCHEDULER_PARAMETERS = 57, /* skipgen autogen */
REMOTE_PROC_DOMAIN_SET_SCHEDULER_PARAMETERS = 58, /* autogen autogen */
REMOTE_PROC_GET_HOSTNAME = 59, /* autogen autogen priority:high */
- REMOTE_PROC_SUPPORTS_FEATURE = 60, /* autogen autogen priority:high */
+ REMOTE_PROC_SUPPORTS_FEATURE = 60, /* skipgen autogen priority:high */
REMOTE_PROC_DOMAIN_MIGRATE_PREPARE = 61, /* skipgen skipgen */
REMOTE_PROC_DOMAIN_MIGRATE_PERFORM = 62, /* autogen autogen */
diff --git a/src/rpc/virnetserver.c b/src/rpc/virnetserver.c
index f739743..4c8273f8 100644
--- a/src/rpc/virnetserver.c
+++ b/src/rpc/virnetserver.c
@@ -102,6 +102,10 @@ struct _virNetServer {
size_t nclients_max;
virNetServerClientPtr *clients;
+ int keepaliveInterval;
+ unsigned int keepaliveCount;
+ bool keepaliveRequired;
+
unsigned int quit :1;
virNetTLSContextPtr tls;
@@ -260,6 +264,9 @@ static int virNetServerDispatchNewClient(virNetServerServicePtr svc ATTRIBUTE_UN
virNetServerDispatchNewMessage,
srv);
+ virNetServerClientInitKeepAlive(client, srv->keepaliveInterval,
+ srv->keepaliveCount);
+
virNetServerUnlock(srv);
return 0;
@@ -299,6 +306,9 @@ virNetServerPtr virNetServerNew(size_t min_workers,
size_t max_workers,
size_t priority_workers,
size_t max_clients,
+ int keepaliveInterval,
+ unsigned int keepaliveCount,
+ bool keepaliveRequired,
const char *mdnsGroupName,
bool connectDBus ATTRIBUTE_UNUSED,
virNetServerClientInitHook clientInitHook)
@@ -320,6 +330,9 @@ virNetServerPtr virNetServerNew(size_t min_workers,
goto error;
srv->nclients_max = max_clients;
+ srv->keepaliveInterval = keepaliveInterval;
+ srv->keepaliveCount = keepaliveCount;
+ srv->keepaliveRequired = keepaliveRequired;
srv->sigwrite = srv->sigread = -1;
srv->clientInitHook = clientInitHook;
srv->privileged = geteuid() == 0 ? true : false;
@@ -839,3 +852,12 @@ void virNetServerClose(virNetServerPtr srv)
virNetServerUnlock(srv);
}
+
+bool virNetServerKeepAliveRequired(virNetServerPtr srv)
+{
+ bool required;
+ virNetServerLock(srv);
+ required = srv->keepaliveRequired;
+ virNetServerUnlock(srv);
+ return required;
+}
diff --git a/src/rpc/virnetserver.h b/src/rpc/virnetserver.h
index cc9d039..a04ffdd 100644
--- a/src/rpc/virnetserver.h
+++ b/src/rpc/virnetserver.h
@@ -41,6 +41,9 @@ virNetServerPtr virNetServerNew(size_t min_workers,
size_t max_workers,
size_t priority_workers,
size_t max_clients,
+ int keepaliveInterval,
+ unsigned int keepaliveCount,
+ bool keepaliveRequired,
const char *mdnsGroupName,
bool connectDBus,
virNetServerClientInitHook clientInitHook);
@@ -88,4 +91,6 @@ void virNetServerFree(virNetServerPtr srv);
void virNetServerClose(virNetServerPtr srv);
+bool virNetServerKeepAliveRequired(virNetServerPtr srv);
+
#endif
diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c
index 05077d6..c5641ef 100644
--- a/src/rpc/virnetserverclient.c
+++ b/src/rpc/virnetserverclient.c
@@ -33,6 +33,7 @@
#include "virterror_internal.h"
#include "memory.h"
#include "threads.h"
+#include "virkeepalive.h"
#define VIR_FROM_THIS VIR_FROM_RPC
#define virNetError(code, ...) \
@@ -98,6 +99,9 @@ struct _virNetServerClient
void *privateData;
virNetServerClientFreeFunc privateDataFreeFunc;
virNetServerClientCloseFunc privateDataCloseFunc;
+
+ virKeepAlivePtr keepalive;
+ int keepaliveFilter;
};
@@ -207,15 +211,15 @@ static void virNetServerClientUpdateEvent(virNetServerClientPtr client)
}
-int virNetServerClientAddFilter(virNetServerClientPtr client,
- virNetServerClientFilterFunc func,
- void *opaque)
+static int
+virNetServerClientAddFilterLocked(virNetServerClientPtr client,
+ virNetServerClientFilterFunc func,
+ void *opaque)
{
virNetServerClientFilterPtr filter;
+ virNetServerClientFilterPtr *place;
int ret = -1;
- virNetServerClientLock(client);
-
if (VIR_ALLOC(filter) < 0) {
virReportOOMError();
goto cleanup;
@@ -225,22 +229,34 @@ int virNetServerClientAddFilter(virNetServerClientPtr client,
filter->func = func;
filter->opaque = opaque;
- filter->next = client->filters;
- client->filters = filter;
+ place = &client->filters;
+ while (*place)
+ place = &(*place)->next;
+ *place = filter;
ret = filter->id;
cleanup:
- virNetServerClientUnlock(client);
return ret;
}
+int virNetServerClientAddFilter(virNetServerClientPtr client,
+ virNetServerClientFilterFunc func,
+ void *opaque)
+{
+ int ret;
-void virNetServerClientRemoveFilter(virNetServerClientPtr client,
- int filterID)
+ virNetServerClientLock(client);
+ ret = virNetServerClientAddFilterLocked(client, func, opaque);
+ virNetServerClientUnlock(client);
+ return ret;
+}
+
+static void
+virNetServerClientRemoveFilterLocked(virNetServerClientPtr client,
+ int filterID)
{
virNetServerClientFilterPtr tmp, prev;
- virNetServerClientLock(client);
prev = NULL;
tmp = client->filters;
@@ -257,7 +273,13 @@ void virNetServerClientRemoveFilter(virNetServerClientPtr client,
prev = tmp;
tmp = tmp->next;
}
+}
+void virNetServerClientRemoveFilter(virNetServerClientPtr client,
+ int filterID)
+{
+ virNetServerClientLock(client);
+ virNetServerClientRemoveFilterLocked(client, filterID);
virNetServerClientUnlock(client);
}
@@ -318,6 +340,7 @@ virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock,
client->readonly = readonly;
client->tlsCtxt = tls;
client->nrequests_max = nrequests_max;
+ client->keepaliveFilter = -1;
if (tls)
virNetTLSContextRef(tls);
@@ -577,6 +600,7 @@ void virNetServerClientFree(virNetServerClientPtr client)
void virNetServerClientClose(virNetServerClientPtr client)
{
virNetServerClientCloseFunc cf;
+ virKeepAlivePtr ka;
virNetServerClientLock(client);
VIR_DEBUG("client=%p refs=%d", client, client->refs);
@@ -585,6 +609,20 @@ void virNetServerClientClose(virNetServerClientPtr client)
return;
}
+ if (client->keepaliveFilter >= 0)
+ virNetServerClientRemoveFilterLocked(client, client->keepaliveFilter);
+
+ if (client->keepalive) {
+ virKeepAliveStop(client->keepalive);
+ ka = client->keepalive;
+ client->keepalive = NULL;
+ client->refs++;
+ virNetServerClientUnlock(client);
+ virKeepAliveFree(ka);
+ virNetServerClientLock(client);
+ client->refs--;
+ }
+
if (client->privateDataCloseFunc) {
cf = client->privateDataCloseFunc;
client->refs++;
@@ -988,6 +1026,7 @@ int virNetServerClientSendMessage(virNetServerClientPtr client,
VIR_DEBUG("msg=%p proc=%d len=%zu offset=%zu",
msg, msg->header.proc,
msg->bufferLength, msg->bufferOffset);
+
virNetServerClientLock(client);
if (client->sock && !client->wantClose) {
@@ -1003,6 +1042,7 @@ int virNetServerClientSendMessage(virNetServerClientPtr client,
}
virNetServerClientUnlock(client);
+
return ret;
}
@@ -1016,3 +1056,84 @@ bool virNetServerClientNeedAuth(virNetServerClientPtr client)
virNetServerClientUnlock(client);
return need;
}
+
+
+static void
+virNetServerClientKeepAliveDeadCB(void *opaque)
+{
+ virNetServerClientImmediateClose(opaque);
+}
+
+static int
+virNetServerClientKeepAliveSendCB(void *opaque,
+ virNetMessagePtr msg)
+{
+ return virNetServerClientSendMessage(opaque, msg);
+}
+
+static void
+virNetServerClientFreeCB(void *opaque)
+{
+ virNetServerClientFree(opaque);
+}
+
+static int
+virNetServerClientKeepAliveFilter(virNetServerClientPtr client,
+ virNetMessagePtr msg,
+ void *opaque ATTRIBUTE_UNUSED)
+{
+ if (virKeepAliveCheckMessage(client->keepalive, msg)) {
+ virNetMessageFree(msg);
+ client->nrequests--;
+ return 1;
+ }
+
+ return 0;
+}
+
+int
+virNetServerClientInitKeepAlive(virNetServerClientPtr client,
+ int interval,
+ unsigned int count)
+{
+ virKeepAlivePtr ka;
+ int ret = -1;
+
+ virNetServerClientLock(client);
+
+ if (!(ka = virKeepAliveNew(interval, count, client,
+ virNetServerClientKeepAliveSendCB,
+ virNetServerClientKeepAliveDeadCB,
+ virNetServerClientFreeCB)))
+ goto cleanup;
+ /* keepalive object has a reference to client */
+ client->refs++;
+
+ client->keepaliveFilter =
+ virNetServerClientAddFilterLocked(client,
+ virNetServerClientKeepAliveFilter,
+ NULL);
+ if (client->keepaliveFilter < 0)
+ goto cleanup;
+
+ client->keepalive = ka;
+ ka = NULL;
+
+cleanup:
+ virNetServerClientUnlock(client);
+ if (ka)
+ virKeepAliveStop(ka);
+ virKeepAliveFree(ka);
+
+ return ret;
+}
+
+int
+virNetServerClientStartKeepAlive(virNetServerClientPtr client)
+{
+ int ret;
+ virNetServerClientLock(client);
+ ret = virKeepAliveStart(client->keepalive, 0, 0);
+ virNetServerClientUnlock(client);
+ return ret;
+}
diff --git a/src/rpc/virnetserverclient.h b/src/rpc/virnetserverclient.h
index bedb179..a201dca 100644
--- a/src/rpc/virnetserverclient.h
+++ b/src/rpc/virnetserverclient.h
@@ -99,6 +99,13 @@ bool virNetServerClientWantClose(virNetServerClientPtr client);
int virNetServerClientInit(virNetServerClientPtr client);
+int virNetServerClientInitKeepAlive(virNetServerClientPtr client,
+ int interval,
+ unsigned int count);
+bool virNetServerClientCheckKeepAlive(virNetServerClientPtr client,
+ virNetMessagePtr msg);
+int virNetServerClientStartKeepAlive(virNetServerClientPtr client);
+
const char *virNetServerClientLocalAddrString(virNetServerClientPtr client);
const char *virNetServerClientRemoteAddrString(virNetServerClientPtr client);
--
1.7.7
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