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event: server RPC protocol tweaks for domain lifecycle events

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This patch adds some new RPC call numbers, but for ease of review,
they sit idle until a later patch adds the client counterpart to
drive the new RPCs.  Also for ease of review, I limited this patch
to just the lifecycle event; although converting the remaining
15 domain events will be quite mechanical.  On the server side,
we have to have a function per RPC call, largely with duplicated
bodies (the key difference being that we store in our callback
opaque pointer whether events should be fired with old or new
style); meanwhile, a single function can drive multiple RPC
messages.  With a strategic choice of XDR struct layout, we can
make the event generation code for both styles fairly compact.

I debated about adding a tri-state witness variable per
connection (values 'unknown', 'legacy', 'modern').  It would start
as 'unknown', move to 'legacy' if any RPC call is made to a legacy
event call, and move to 'modern' if the feature probe is made;
then the event code could issue an error if the witness state is
incorrect (a legacy RPC call while in 'modern', a modern RPC call
while in 'unknown' or 'legacy', and a feature probe while in
'legacy' or 'modern').  But while it might prevent odd behavior
caused by protocol fuzzing, I don't see that it would prevent
any security holes, so I considered it bloat.

Note that sticking @acl markers on the new RPCs generates unused
functions in access/viraccessapicheck.c, because there is no new
API call that needs to use the new checks; however, having a
consistent .x file is worth the dead code.

* src/libvirt_internal.h (VIR_DRV_FEATURE_REMOTE_EVENT_CALLBACK):
New feature.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_REGISTER_ANY)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_DEREGISTER_ANY)
(REMOTE_PROC_DOMAIN_EVENT_CALLBACK_LIFECYCLE): New RPCs.
* daemon/remote.c (daemonClientCallback): Add field.
(remoteDispatchConnectDomainEventCallbackRegisterAny)
(remoteDispatchConnectDomainEventCallbackDeregisterAny): New
functions.
(remoteDispatchConnectDomainEventRegisterAny)
(remoteDispatchConnectDomainEventDeregisterAny): Mark legacy use.
(remoteRelayDomainEventLifecycle): Change message based on legacy
or new use.
(remoteDispatchConnectSupportsFeature): Advertise new feature.
* src/remote_protocol-structs: Regenerate.

Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Eric Blake 2014-01-08 13:59:35 -07:00
parent 047fd2e83e
commit 0372295770
4 changed files with 226 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

173
daemon/remote.c
View File

@ -79,6 +79,7 @@ struct daemonClientEventCallback {
virNetServerClientPtr client;
int eventID;
int callbackID;
bool legacy;
};
static virDomainPtr get_nonnull_domain(virConnectPtr conn, remote_nonnull_domain domain);
@ -199,8 +200,8 @@ remoteRelayDomainEventLifecycle(virConnectPtr conn,
!remoteRelayDomainEventCheckACL(callback->client, conn, dom))
return -1;
VIR_DEBUG("Relaying domain lifecycle event %d %d, callback %d",
event, detail, callback->callbackID);
VIR_DEBUG("Relaying domain lifecycle event %d %d, callback %d legacy %d",
event, detail, callback->callbackID, callback->legacy);
/* build return data */
memset(&data, 0, sizeof(data));
@ -208,9 +209,20 @@ remoteRelayDomainEventLifecycle(virConnectPtr conn,
data.event = event;
data.detail = detail;
remoteDispatchObjectEventSend(callback->client, remoteProgram,
REMOTE_PROC_DOMAIN_EVENT_LIFECYCLE,
(xdrproc_t)xdr_remote_domain_event_lifecycle_msg, &data);
if (callback->legacy) {
remoteDispatchObjectEventSend(callback->client, remoteProgram,
REMOTE_PROC_DOMAIN_EVENT_LIFECYCLE,
(xdrproc_t)xdr_remote_domain_event_lifecycle_msg,
&data);
} else {
remote_domain_event_callback_lifecycle_msg msg = { callback->callbackID,
data };
remoteDispatchObjectEventSend(callback->client, remoteProgram,
REMOTE_PROC_DOMAIN_EVENT_CALLBACK_LIFECYCLE,
(xdrproc_t)xdr_remote_domain_event_callback_lifecycle_msg,
&msg);
}
return 0;
}
@ -3281,6 +3293,7 @@ remoteDispatchConnectDomainEventRegister(virNetServerPtr server ATTRIBUTE_UNUSED
callback->client = client;
callback->eventID = VIR_DOMAIN_EVENT_ID_LIFECYCLE;
callback->callbackID = -1;
callback->legacy = true;
ref = callback;
if (VIR_APPEND_ELEMENT(priv->domainEventCallbacks,
priv->ndomainEventCallbacks,
@ -3469,6 +3482,12 @@ cleanup:
return rv;
}
/* Due to back-compat reasons, two RPC calls map to the same libvirt
* API of virConnectDomainEventRegisterAny. A client should only use
* the new call if they have probed
* VIR_DRV_SUPPORTS_FEATURE(VIR_DRV_FEATURE_REMOTE_EVENT_CALLBACK),
* and must not mix the two styles. */
static int
remoteDispatchConnectDomainEventRegisterAny(virNetServerPtr server ATTRIBUTE_UNUSED,
virNetServerClientPtr client,
@ -3490,9 +3509,13 @@ remoteDispatchConnectDomainEventRegisterAny(virNetServerPtr server ATTRIBUTE_UNU
virMutexLock(&priv->lock);
if (args->eventID >= VIR_DOMAIN_EVENT_ID_LAST ||
/* We intentionally do not use VIR_DOMAIN_EVENT_ID_LAST here; any
* new domain events added after this point should only use the
* modern callback style of RPC. */
if (args->eventID > VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED ||
args->eventID < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, _("unsupported event ID %d"), args->eventID);
virReportError(VIR_ERR_INTERNAL_ERROR, _("unsupported event ID %d"),
args->eventID);
goto cleanup;
}
@ -3507,6 +3530,7 @@ remoteDispatchConnectDomainEventRegisterAny(virNetServerPtr server ATTRIBUTE_UNU
callback->client = client;
callback->eventID = args->eventID;
callback->callbackID = -1;
callback->legacy = true;
ref = callback;
if (VIR_APPEND_ELEMENT(priv->domainEventCallbacks,
priv->ndomainEventCallbacks,
@ -3538,6 +3562,85 @@ cleanup:
}
static int
remoteDispatchConnectDomainEventCallbackRegisterAny(virNetServerPtr server ATTRIBUTE_UNUSED,
virNetServerClientPtr client,
virNetMessagePtr msg ATTRIBUTE_UNUSED,
virNetMessageErrorPtr rerr ATTRIBUTE_UNUSED,
remote_connect_domain_event_callback_register_any_args *args,
remote_connect_domain_event_callback_register_any_ret *ret)
{
int callbackID;
int rv = -1;
daemonClientEventCallbackPtr callback = NULL;
daemonClientEventCallbackPtr ref;
struct daemonClientPrivate *priv =
virNetServerClientGetPrivateData(client);
virDomainPtr dom = NULL;
if (!priv->conn) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("connection not open"));
goto cleanup;
}
virMutexLock(&priv->lock);
if (args->dom &&
!(dom = get_nonnull_domain(priv->conn, *args->dom)))
goto cleanup;
/* FIXME: support all domain events */
if (args->eventID != VIR_DOMAIN_EVENT_ID_LIFECYCLE) {
virReportError(VIR_ERR_INTERNAL_ERROR, _("unsupported event ID %d"),
args->eventID);
goto cleanup;
}
/* If we call register first, we could append a complete callback
* to our array, but on OOM append failure, we'd have to then hope
* deregister works to undo our register. So instead we append an
* incomplete callback to our array, then register, then fix up
* our callback; but since VIR_APPEND_ELEMENT clears 'callback' on
* success, we use 'ref' to save a copy of the pointer. */
if (VIR_ALLOC(callback) < 0)
goto cleanup;
callback->client = client;
callback->eventID = args->eventID;
callback->callbackID = -1;
ref = callback;
if (VIR_APPEND_ELEMENT(priv->domainEventCallbacks,
priv->ndomainEventCallbacks,
callback) < 0)
goto cleanup;
if ((callbackID = virConnectDomainEventRegisterAny(priv->conn,
dom,
args->eventID,
domainEventCallbacks[args->eventID],
ref,
remoteEventCallbackFree)) < 0) {
VIR_SHRINK_N(priv->domainEventCallbacks,
priv->ndomainEventCallbacks, 1);
callback = ref;
goto cleanup;
}
ref->callbackID = callbackID;
ret->callbackID = callbackID;
rv = 0;
cleanup:
VIR_FREE(callback);
if (rv < 0)
virNetMessageSaveError(rerr);
if (dom)
virDomainFree(dom);
virMutexUnlock(&priv->lock);
return rv;
}
static int
remoteDispatchConnectDomainEventDeregisterAny(virNetServerPtr server ATTRIBUTE_UNUSED,
virNetServerClientPtr client,
@ -3558,9 +3661,13 @@ remoteDispatchConnectDomainEventDeregisterAny(virNetServerPtr server ATTRIBUTE_U
virMutexLock(&priv->lock);
if (args->eventID >= VIR_DOMAIN_EVENT_ID_LAST ||
/* We intentionally do not use VIR_DOMAIN_EVENT_ID_LAST here; any
* new domain events added after this point should only use the
* modern callback style of RPC. */
if (args->eventID > VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED ||
args->eventID < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, _("unsupported event ID %d"), args->eventID);
virReportError(VIR_ERR_INTERNAL_ERROR, _("unsupported event ID %d"),
args->eventID);
goto cleanup;
}
@ -3591,6 +3698,53 @@ cleanup:
return rv;
}
static int
remoteDispatchConnectDomainEventCallbackDeregisterAny(virNetServerPtr server ATTRIBUTE_UNUSED,
virNetServerClientPtr client,
virNetMessagePtr msg ATTRIBUTE_UNUSED,
virNetMessageErrorPtr rerr ATTRIBUTE_UNUSED,
remote_connect_domain_event_callback_deregister_any_args *args)
{
int rv = -1;
size_t i;
struct daemonClientPrivate *priv =
virNetServerClientGetPrivateData(client);
if (!priv->conn) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("connection not open"));
goto cleanup;
}
virMutexLock(&priv->lock);
for (i = 0; i < priv->ndomainEventCallbacks; i++) {
if (priv->domainEventCallbacks[i]->callbackID == args->callbackID)
break;
}
if (i == priv->ndomainEventCallbacks) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("domain event callback %d not registered"),
args->callbackID);
goto cleanup;
}
if (virConnectDomainEventDeregisterAny(priv->conn, args->callbackID) < 0)
goto cleanup;
VIR_DELETE_ELEMENT(priv->domainEventCallbacks, i,
priv->ndomainEventCallbacks);
rv = 0;
cleanup:
if (rv < 0)
virNetMessageSaveError(rerr);
virMutexUnlock(&priv->lock);
return rv;
}
static int
qemuDispatchDomainMonitorCommand(virNetServerPtr server ATTRIBUTE_UNUSED,
virNetServerClientPtr client ATTRIBUTE_UNUSED,
@ -3911,6 +4065,7 @@ static int remoteDispatchConnectSupportsFeature(virNetServerPtr server ATTRIBUTE
switch (args->feature) {
case VIR_DRV_FEATURE_FD_PASSING:
case VIR_DRV_FEATURE_REMOTE_EVENT_CALLBACK:
supported = 1;
break;

7
src/libvirt_internal.h
View File

@ -1,7 +1,7 @@
/*
* libvirt_internal.h: internally exported APIs, not for public use
*
* Copyright (C) 2006-2013 Red Hat, Inc.
* Copyright (C) 2006-2014 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
@ -115,6 +115,11 @@ enum {
* Support for migration parameters.
*/
VIR_DRV_FEATURE_MIGRATION_PARAMS = 13,
/*
* Support for server-side event filtering via callback ids in events.
*/
VIR_DRV_FEATURE_REMOTE_EVENT_CALLBACK = 14,
};

40
src/remote/remote_protocol.x
View File

@ -1972,6 +1972,10 @@ struct remote_domain_event_lifecycle_msg {
int event;
int detail;
};
struct remote_domain_event_callback_lifecycle_msg {
int callbackID;
remote_domain_event_lifecycle_msg msg;
};
struct remote_connect_domain_xml_from_native_args {
@ -2248,6 +2252,19 @@ struct remote_connect_domain_event_deregister_any_args {
int eventID;
};
struct remote_connect_domain_event_callback_register_any_args {
int eventID;
remote_domain dom;
};
struct remote_connect_domain_event_callback_register_any_ret {
int callbackID;
};
struct remote_connect_domain_event_callback_deregister_any_args {
int callbackID;
};
struct remote_domain_event_reboot_msg {
remote_nonnull_domain dom;
};
@ -5068,5 +5085,26 @@ enum remote_procedure {
* @generate: both
* @acl: none
*/
REMOTE_PROC_NETWORK_EVENT_LIFECYCLE = 315
REMOTE_PROC_NETWORK_EVENT_LIFECYCLE = 315,
/**
* @generate: none
* @priority: high
* @acl: connect:search_domains
* @aclfilter: domain:getattr
*/
REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_REGISTER_ANY = 316,
/**
* @generate: none
* @priority: high
* @acl: connect:read
*/
REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_DEREGISTER_ANY = 317,
/**
* @generate: both
* @acl: none
*/
REMOTE_PROC_DOMAIN_EVENT_CALLBACK_LIFECYCLE = 318
};

17
src/remote_protocol-structs
View File

@ -1491,6 +1491,10 @@ struct remote_domain_event_lifecycle_msg {
int event;
int detail;
};
struct remote_domain_event_callback_lifecycle_msg {
int callbackID;
remote_domain_event_lifecycle_msg msg;
};
struct remote_connect_domain_xml_from_native_args {
remote_nonnull_string nativeFormat;
remote_nonnull_string nativeConfig;
@ -1707,6 +1711,16 @@ struct remote_connect_domain_event_register_any_args {
struct remote_connect_domain_event_deregister_any_args {
int eventID;
};
struct remote_connect_domain_event_callback_register_any_args {
int eventID;
remote_domain dom;
};
struct remote_connect_domain_event_callback_register_any_ret {
int callbackID;
};
struct remote_connect_domain_event_callback_deregister_any_args {
int callbackID;
};
struct remote_domain_event_reboot_msg {
remote_nonnull_domain dom;
};
@ -2660,4 +2674,7 @@ enum remote_procedure {
REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY = 313,
REMOTE_PROC_CONNECT_NETWORK_EVENT_DEREGISTER_ANY = 314,
REMOTE_PROC_NETWORK_EVENT_LIFECYCLE = 315,
REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_REGISTER_ANY = 316,
REMOTE_PROC_CONNECT_DOMAIN_EVENT_CALLBACK_DEREGISTER_ANY = 317,
REMOTE_PROC_DOMAIN_EVENT_CALLBACK_LIFECYCLE = 318,
};