/**
* virNetlinkEventServiceStop:
*
* stop the monitor to receive netlink messages for libvirtd.
* This removes the netlink socket fd from the event handler.
*
* Returns -1 if the monitor cannot be unregistered, 0 upon success
*/
int
virNetlinkEventServiceStop(void)
{
virNetlinkEventSrvPrivatePtr srv = server;
int i;
VIR_INFO("stopping netlink event service");
if (!server)
return 0;
virNetlinkEventServerLock(srv);
nl_close(srv->netlinknh);
virNetlinkFree(srv->netlinknh);
virEventRemoveHandle(srv->eventwatch);
/* free any remaining clients on the list */
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted == VIR_NETLINK_HANDLE_VALID)
virNetlinkEventRemoveClientPrimitive(i);
}
server = 0;
virNetlinkEventServerUnlock(srv);
virMutexDestroy(&srv->lock);
VIR_FREE(srv);
return 0;
}
/**
* virNetlinkEventServiceStopAll:
*
* Stop all the monitors to receive netlink messages for libvirtd.
*
* Returns -1 if any monitor cannot be unregistered, 0 upon success
*/
int
virNetlinkEventServiceStopAll(void)
{
size_t i, j;
virNetlinkEventSrvPrivatePtr srv = NULL;
VIR_INFO("stopping all netlink event services");
for (i = 0; i < MAX_LINKS; i++) {
srv = server[i];
if (!srv)
continue;
virNetlinkEventServerLock(srv);
nl_close(srv->netlinknh);
virNetlinkFree(srv->netlinknh);
virEventRemoveHandle(srv->eventwatch);
for (j = 0; j < srv->handlesCount; j++) {
if (srv->handles[j].deleted == VIR_NETLINK_HANDLE_VALID)
virNetlinkEventRemoveClientPrimitive(j, i);
}
server[i] = NULL;
virNetlinkEventServerUnlock(srv);
virMutexDestroy(&srv->lock);
VIR_FREE(srv);
}
return 0;
}
/**
* virNetlinkEventServiceStop:
*
* stop the monitor to receive netlink messages for libvirtd.
* This removes the netlink socket fd from the event handler.
*
* @protocol: netlink protocol
*
* Returns -1 if the monitor cannot be unregistered, 0 upon success
*/
int
virNetlinkEventServiceStop(unsigned int protocol)
{
if (protocol >= MAX_LINKS)
return -EINVAL;
virNetlinkEventSrvPrivatePtr srv = server[protocol];
size_t i;
VIR_INFO("stopping netlink event service");
if (!server[protocol])
return 0;
virNetlinkEventServerLock(srv);
nl_close(srv->netlinknh);
virNetlinkFree(srv->netlinknh);
virEventRemoveHandle(srv->eventwatch);
/* free any remaining clients on the list */
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted == VIR_NETLINK_HANDLE_VALID)
virNetlinkEventRemoveClientPrimitive(i, protocol);
}
server[protocol] = NULL;
virNetlinkEventServerUnlock(srv);
virMutexDestroy(&srv->lock);
VIR_FREE(srv);
return 0;
}
/**
* virNetlinkEventAddClient:
*
* @handleCB: callback to invoke when an event occurs
* @removeCB: callback to invoke when removing a client
* @opaque: user data to pass to callback
* @macaddr: macaddr to store with the data. Used to identify callers.
* May be null.
*
* register a callback for handling of netlink messages. The
* registered function receives the entire netlink message and
* may choose to act upon it.
*
* Returns -1 if the file handle cannot be registered, number of
* monitor upon success.
*/
int
virNetlinkEventAddClient(virNetlinkEventHandleCallback handleCB,
virNetlinkEventRemoveCallback removeCB,
void *opaque, const unsigned char *macaddr)
{
int i, r, ret = -1;
virNetlinkEventSrvPrivatePtr srv = server;
if (handleCB == NULL) {
netlinkError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Invalid NULL callback provided"));
return -1;
}
virNetlinkEventServerLock(srv);
VIR_DEBUG("adding client: %d.", nextWatch);
r = 0;
/* first try to re-use deleted free slots */
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted == VIR_NETLINK_HANDLE_DELETED) {
r = i;
goto addentry;
}
}
/* Resize the eventLoop array if needed */
if (srv->handlesCount == srv->handlesAlloc) {
VIR_DEBUG("Used %zu handle slots, adding at least %d more",
srv->handlesAlloc, NETLINK_EVENT_ALLOC_EXTENT);
if (VIR_RESIZE_N(srv->handles, srv->handlesAlloc,
srv->handlesCount, NETLINK_EVENT_ALLOC_EXTENT) < 0) {
virReportOOMError();
goto error;
}
}
r = srv->handlesCount++;
addentry:
srv->handles[r].watch = nextWatch;
srv->handles[r].handleCB = handleCB;
srv->handles[r].removeCB = removeCB;
srv->handles[r].opaque = opaque;
srv->handles[r].deleted = VIR_NETLINK_HANDLE_VALID;
if (macaddr)
memcpy(srv->handles[r].macaddr, macaddr, VIR_MAC_BUFLEN);
else
memset(srv->handles[r].macaddr, 0, VIR_MAC_BUFLEN);
VIR_DEBUG("added client to loop slot: %d. with macaddr ptr=%p", r, macaddr);
ret = nextWatch++;
error:
virNetlinkEventServerUnlock(srv);
return ret;
}
static void
virNetlinkEventCallback(int watch,
int fd ATTRIBUTE_UNUSED,
int events ATTRIBUTE_UNUSED,
void *opaque)
{
virNetlinkEventSrvPrivatePtr srv = opaque;
struct nlmsghdr *msg;
struct sockaddr_nl peer;
struct ucred *creds = NULL;
size_t i;
int length;
bool handled = false;
length = nl_recv(srv->netlinknh, &peer,
(unsigned char **)&msg, &creds);
if (length == 0)
return;
if (length < 0) {
virReportSystemError(errno,
"%s", _("nl_recv returned with error"));
return;
}
virNetlinkEventServerLock(srv);
VIR_DEBUG("dispatching to max %d clients, called from event watch %d",
(int)srv->handlesCount, watch);
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted != VIR_NETLINK_HANDLE_VALID)
continue;
VIR_DEBUG("dispatching client %zu.", i);
(srv->handles[i].handleCB)(msg, length, &peer, &handled,
srv->handles[i].opaque);
}
if (!handled)
VIR_DEBUG("event not handled.");
VIR_FREE(msg);
virNetlinkEventServerUnlock(srv);
}
/**
* virNetlinkEventRemoveClient:
*
* @watch: watch whose handle to remove
* @macaddr: macaddr whose handle to remove
* @protocol: netlink protocol
*
* Unregister a callback from a netlink monitor.
* The handler function referenced will no longer receive netlink messages.
* Either watch or macaddr may be used, the other should be null.
*
* Returns -1 if the file handle was not registered, 0 upon success
*/
int
virNetlinkEventRemoveClient(int watch, const virMacAddr *macaddr,
unsigned int protocol)
{
size_t i;
int ret = -1;
virNetlinkEventSrvPrivatePtr srv = NULL;
if (protocol >= MAX_LINKS)
return -EINVAL;
srv = server[protocol];
VIR_DEBUG("removing client watch=%d, mac=%p.", watch, macaddr);
if (watch <= 0 && !macaddr) {
VIR_WARN("Ignoring invalid netlink client id: %d", watch);
return -1;
}
virNetlinkEventServerLock(srv);
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted != VIR_NETLINK_HANDLE_VALID)
continue;
if ((watch && srv->handles[i].watch == watch) ||
(!watch &&
virMacAddrCmp(macaddr, &srv->handles[i].macaddr) == 0)) {
VIR_DEBUG("removed client: %d by %s.",
srv->handles[i].watch, watch ? "index" : "mac");
virNetlinkEventRemoveClientPrimitive(i, protocol);
ret = 0;
goto cleanup;
}
}
VIR_DEBUG("no client found to remove.");
cleanup:
virNetlinkEventServerUnlock(srv);
return ret;
}
/**
* virNetlinkEventRemoveClient:
*
* @watch: watch whose handle to remove
* @macaddr: macaddr whose handle to remove
*
* Unregister a callback from a netlink monitor.
* The handler function referenced will no longer receive netlink messages.
* Either watch or macaddr may be used, the other should be null.
*
* Returns -1 if the file handle was not registered, 0 upon success
*/
int
virNetlinkEventRemoveClient(int watch, const unsigned char *macaddr)
{
int i;
int ret = -1;
virNetlinkEventSrvPrivatePtr srv = server;
VIR_DEBUG("removing client watch=%d, mac=%p.", watch, macaddr);
if (watch <= 0 && !macaddr) {
VIR_WARN("Ignoring invalid netlink client id: %d", watch);
return -1;
}
virNetlinkEventServerLock(srv);
for (i = 0; i < srv->handlesCount; i++) {
if (srv->handles[i].deleted != VIR_NETLINK_HANDLE_VALID)
continue;
if ((watch && srv->handles[i].watch == watch) ||
(!watch &&
memcmp(macaddr, srv->handles[i].macaddr, VIR_MAC_BUFLEN) == 0)) {
VIR_DEBUG("removed client: %d by %s.",
srv->handles[i].watch, watch ? "index" : "mac");
virNetlinkEventRemoveClientPrimitive(i);
ret = 0;
goto cleanup;
}
}
VIR_DEBUG("no client found to remove.");
cleanup:
virNetlinkEventServerUnlock(srv);
return ret;
}
/**
* virNetlinkEventServiceStart:
*
* start a monitor to receive netlink messages for libvirtd.
* This registers a netlink socket with the event interface.
*
* Returns -1 if the monitor cannot be registered, 0 upon success
*/
int
virNetlinkEventServiceStart(void)
{
virNetlinkEventSrvPrivatePtr srv;
int fd;
int ret = -1;
if (server)
return 0;
VIR_INFO("starting netlink event service");
if (VIR_ALLOC(srv) < 0) {
virReportOOMError();
return -1;
}
if (virMutexInit(&srv->lock) < 0) {
VIR_FREE(srv);
return -1;
}
virNetlinkEventServerLock(srv);
/* Allocate a new socket and get fd */
srv->netlinknh = virNetlinkAlloc();
if (!srv->netlinknh) {
virReportSystemError(errno,
"%s", _("cannot allocate nlhandle for virNetlinkEvent server"));
goto error_locked;
}
if (nl_connect(srv->netlinknh, NETLINK_ROUTE) < 0) {
virReportSystemError(errno,
"%s", _("cannot connect to netlink socket"));
goto error_server;
}
fd = nl_socket_get_fd(srv->netlinknh);
if (fd < 0) {
virReportSystemError(errno,
"%s", _("cannot get netlink socket fd"));
goto error_server;
}
if (nl_socket_set_nonblocking(srv->netlinknh)) {
virReportSystemError(errno, "%s",
_("cannot set netlink socket nonblocking"));
goto error_server;
}
if ((srv->eventwatch = virEventAddHandle(fd,
VIR_EVENT_HANDLE_READABLE,
virNetlinkEventCallback,
srv, NULL)) < 0) {
netlinkError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Failed to add netlink event handle watch"));
goto error_server;
}
srv->netlinkfd = fd;
VIR_DEBUG("netlink event listener on fd: %i running", fd);
ret = 0;
server = srv;
error_server:
if (ret < 0) {
nl_close(srv->netlinknh);
virNetlinkFree(srv->netlinknh);
}
error_locked:
virNetlinkEventServerUnlock(srv);
if (ret < 0) {
virMutexDestroy(&srv->lock);
VIR_FREE(srv);
}
return ret;
}
/**
* virNetlinkEventServiceStart:
*
* start a monitor to receive netlink messages for libvirtd.
* This registers a netlink socket with the event interface.
*
* @protocol: netlink protocol
* @groups: broadcast groups to join in
* Returns -1 if the monitor cannot be registered, 0 upon success
*/
int
virNetlinkEventServiceStart(unsigned int protocol, unsigned int groups)
{
virNetlinkEventSrvPrivatePtr srv;
int fd;
int ret = -1;
if (protocol >= MAX_LINKS) {
virReportSystemError(EINVAL,
_("invalid protocol argument: %d"), protocol);
return -EINVAL;
}
if (server[protocol])
return 0;
VIR_INFO("starting netlink event service with protocol %d", protocol);
if (VIR_ALLOC(srv) < 0)
return -1;
if (virMutexInit(&srv->lock) < 0) {
VIR_FREE(srv);
return -1;
}
virNetlinkEventServerLock(srv);
/* Allocate a new socket and get fd */
if (!(srv->netlinknh = virNetlinkCreateSocket(protocol)))
goto error_locked;
fd = nl_socket_get_fd(srv->netlinknh);
if (fd < 0) {
virReportSystemError(errno,
"%s", _("cannot get netlink socket fd"));
goto error_server;
}
if (groups && nl_socket_add_membership(srv->netlinknh, groups) < 0) {
virReportSystemError(errno,
"%s", _("cannot add netlink membership"));
goto error_server;
}
if (nl_socket_set_nonblocking(srv->netlinknh)) {
virReportSystemError(errno, "%s",
_("cannot set netlink socket nonblocking"));
goto error_server;
}
if ((srv->eventwatch = virEventAddHandle(fd,
VIR_EVENT_HANDLE_READABLE,
virNetlinkEventCallback,
srv, NULL)) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Failed to add netlink event handle watch"));
goto error_server;
}
srv->netlinkfd = fd;
VIR_DEBUG("netlink event listener on fd: %i running", fd);
ret = 0;
server[protocol] = srv;
error_server:
if (ret < 0) {
nl_close(srv->netlinknh);
virNetlinkFree(srv->netlinknh);
}
error_locked:
virNetlinkEventServerUnlock(srv);
if (ret < 0) {
virMutexDestroy(&srv->lock);
VIR_FREE(srv);
}
return ret;
}