[libvirt] [RFC PATCH 1/7] config: Adding source for the config driver

[Adam Walters]

This is the source code to the config driver. This driver is a hypervisor driver that does not support any domain operations. The sole purpose of this driver is to allow access to various bits of configuration information, such as secret or network definitions, from the initialization and auto-start routines of other drivers. This is the first step toward breaking the circular dependencies present in QEMU and the Storage driver, in addition to preventing future cases.

Signed-off-by: Adam Walters <adam at pandorasboxen.com>
---
 src/config/config_driver.c | 237 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 237 insertions(+)
 create mode 100644 src/config/config_driver.c

diff --git a/src/config/config_driver.c b/src/config/config_driver.c
new file mode 100644
index 0000000..a057300
--- /dev/null
+++ b/src/config/config_driver.c
@@ -0,0 +1,237 @@
+/*
+ * config_driver.c: core driver methods for accessing configs
+ *
+ * Copyright (C) 2013 Adam Walters
+ *
+ * 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, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Author: Adam Walters <adam at pandorasboxen.com>
+ */
+#include <config.h>
+#include <string.h>
+
+#include "internal.h"
+#include "datatypes.h"
+#include "driver.h"
+#include "virlog.h"
+#include "viralloc.h"
+#include "virerror.h"
+#include "virstring.h"
+#include "viraccessapicheck.h"
+#include "nodeinfo.h"
+#include "config_driver.h"
+
+#define VIR_FROM_THIS VIR_FROM_CONFIG
+
+virConfigDriverPtr config_driver = NULL;
+
+static int configStateCleanup(void) {
+    if (config_driver == NULL)
+        return -1;
+
+    virObjectUnref(config_driver->closeCallbacks);
+
+    virSysinfoDefFree(config_driver->hostsysinfo);
+
+    virMutexDestroy(&config_driver->lock);
+    VIR_FREE(config_driver);
+
+    return 0;
+}
+
+static int configStateInitialize(bool privileged,
+                                 virStateInhibitCallback callback ATTRIBUTE_UNUSED,
+                                 void *opaque ATTRIBUTE_UNUSED)
+{
+    if (!privileged) {
+        VIR_INFO("Not running privileged, disabling driver");
+        return 0;
+    }
+
+    if (VIR_ALLOC(config_driver) < 0)
+        return -1;
+
+    if (virMutexInit(&config_driver->lock) < 0) {
+        VIR_ERROR(_("cannot initialize mutex"));
+        VIR_FREE(config_driver);
+        return -1;
+    }
+
+    config_driver->hostsysinfo = virSysinfoRead();
+
+    if (!(config_driver->closeCallbacks = virCloseCallbacksNew()))
+        goto cleanup;
+
+    return 0;
+
+cleanup:
+    configStateCleanup();
+    return -1;
+}
+
+static int configStateReload(void) {
+    return 0;
+}
+
+static virDrvOpenStatus configConnectOpen(virConnectPtr conn,
+                                          virConnectAuthPtr auth ATTRIBUTE_UNUSED,
+                                          unsigned int flags)
+{
+    virDrvOpenStatus ret = VIR_DRV_OPEN_ERROR;
+    virCheckFlags(VIR_CONNECT_RO, VIR_DRV_OPEN_ERROR);
+
+    if (conn->uri != NULL) {
+        /* If URI isn't 'config', decline the connection */
+        if (conn->uri->scheme == NULL ||
+            STRNEQ(conn->uri->scheme, "config")) {
+            ret = VIR_DRV_OPEN_DECLINED;
+            goto cleanup;
+        }
+
+        /* Allow remote driver to deal with URIs with hostname set */
+        if (conn->uri->server != NULL) {
+            ret = VIR_DRV_OPEN_DECLINED;
+            goto cleanup;
+        }
+
+        if (config_driver == NULL) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("config state driver is not active"));
+            goto cleanup;
+        }
+    } else {
+        ret = VIR_DRV_OPEN_DECLINED;
+        goto cleanup;
+    }
+
+    if (virConnectOpenEnsureACL(conn) < 0)
+        goto cleanup;
+
+    conn->privateData = config_driver;
+
+    ret = VIR_DRV_OPEN_SUCCESS;
+cleanup:
+    return ret;
+}
+
+static int configConnectClose(virConnectPtr conn ATTRIBUTE_UNUSED)
+{
+    /* Cleanup callbacks on config_driver */
+    /* Set conn->privateData to NULL */
+    return 0;
+}
+
+static int
+configConnectSupportsFeature(virConnectPtr conn, int feature ATTRIBUTE_UNUSED)
+{
+    if (virConnectSupportsFeatureEnsureACL(conn) < 0)
+        return -1;
+
+    return 0;
+}
+
+static const char *configConnectGetType(virConnectPtr conn ATTRIBUTE_UNUSED) {
+    if (virConnectGetTypeEnsureACL(conn) < 0)
+        return NULL;
+
+    return "config";
+}
+
+static int configConnectIsSecure(virConnectPtr conn ATTRIBUTE_UNUSED)
+{
+    return 1;
+}
+
+static int configConnectIsEncrypted(virConnectPtr conn ATTRIBUTE_UNUSED)
+{
+    return 0;
+}
+
+static char *configConnectGetHostname(virConnectPtr conn)
+{
+    if (virConnectGetHostnameEnsureACL(conn) < 0)
+        return NULL;
+
+    return virGetHostname();
+}
+
+static char *
+configConnectGetSysinfo(virConnectPtr conn, unsigned int flags)
+{
+    virConfigDriverPtr driver = conn->privateData;
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+
+    virCheckFlags(0, NULL);
+
+    if (virConnectGetSysinfoEnsureACL(conn) < 0)
+        return NULL;
+
+    if (!driver->hostsysinfo) {
+        return NULL;
+    }
+
+    if (virSysinfoFormat(&buf, driver->hostsysinfo) < 0)
+        return NULL;
+
+    if (virBufferError(&buf)) {
+        virReportOOMError();
+        return NULL;
+    }
+
+    return virBufferContentAndReset(&buf);
+}
+
+static int
+configNodeGetInfo(virConnectPtr conn,
+                  virNodeInfoPtr nodeinfo)
+{
+    if (virNodeGetInfoEnsureACL(conn) < 0)
+        return -1;
+
+    return nodeGetInfo(nodeinfo);
+}
+
+static int configConnectIsAlive(virConnectPtr conn ATTRIBUTE_UNUSED)
+{
+    return 1;
+}
+
+static virDriver configDriver = {
+    .name = "config",
+    .connectOpen = configConnectOpen, /* 0.2.0 */
+    .connectClose = configConnectClose, /* 0.2.0 */
+    .connectSupportsFeature = configConnectSupportsFeature, /* 0.5.0 */
+    .connectGetType = configConnectGetType, /* 0.2.0 */
+    .connectGetHostname = configConnectGetHostname, /* 0.3.3 */
+    .connectGetSysinfo = configConnectGetSysinfo, /* 0.8.8 */
+    .nodeGetInfo = configNodeGetInfo, /* 0.2.0 */
+    .connectIsEncrypted = configConnectIsEncrypted, /* 0.7.3 */
+    .connectIsSecure = configConnectIsSecure, /* 0.7.3 */
+    .connectIsAlive = configConnectIsAlive, /* 0.9.8 */
+};
+
+
+static virStateDriver configStateDriver = {
+    .name = "config",
+    .stateInitialize = configStateInitialize,
+    .stateCleanup = configStateCleanup,
+    .stateReload = configStateReload,
+};
+
+int configRegister(void) {
+    virRegisterDriver(&configDriver);
+    virRegisterStateDriver(&configStateDriver);
+    return 0;
+}
-- 
1.8.5.2