interface_backend_netcf.c

/*
 * interface_backend_netcf.c: backend driver methods to handle physical
 *                            interface configuration using the netcf library.
 *
 * Copyright (C) 2006-2015 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, see
 * <http://www.gnu.org/licenses/>.
 *
 * Author: Laine Stump <laine@redhat.com>
 */

#include <config.h>

#include <netcf.h>

#include "virerror.h"
#include "datatypes.h"
#include "interface_driver.h"
#include "interface_conf.h"
#include "viralloc.h"
#include "virlog.h"
#include "virstring.h"
#include "viraccessapicheck.h"
#include "virinterfaceobj.h"

#define VIR_FROM_THIS VIR_FROM_INTERFACE

VIR_LOG_INIT("interface.interface_backend_netcf");

#define INTERFACE_DRIVER_NAME "netcf"

/* Main driver state */
typedef struct
{
    virObjectLockable parent;
    struct netcf *netcf;
    bool privileged;
} virNetcfDriverState, *virNetcfDriverStatePtr;

static virClassPtr virNetcfDriverStateClass;
static void virNetcfDriverStateDispose(void *obj);

static int
virNetcfDriverStateOnceInit(void)
{
    if (!(virNetcfDriverStateClass = virClassNew(virClassForObjectLockable(),
                                       "virNetcfDriverState",
                                       sizeof(virNetcfDriverState),
                                       virNetcfDriverStateDispose)))
        return -1;
    return 0;
}

VIR_ONCE_GLOBAL_INIT(virNetcfDriverState)

static virNetcfDriverStatePtr driver;


static void
virNetcfDriverStateDispose(void *obj)
{
    virNetcfDriverStatePtr _driver = obj;

    if (_driver->netcf)
        ncf_close(_driver->netcf);
}


static int
netcfStateInitialize(bool privileged,
                     virStateInhibitCallback callback ATTRIBUTE_UNUSED,
                     void *opaque ATTRIBUTE_UNUSED)
{
    if (virNetcfDriverStateInitialize() < 0)
        return -1;

    if (!(driver = virObjectLockableNew(virNetcfDriverStateClass)))
        return -1;

    driver->privileged = privileged;

    /* open netcf */
    if (ncf_init(&driver->netcf, NULL) != 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("failed to initialize netcf"));
        virObjectUnref(driver);
        driver = NULL;
        return -1;
    }
    return 0;
}


static int
netcfStateCleanup(void)
{
    if (!driver)
        return -1;

    if (virObjectUnref(driver)) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Attempt to close netcf state driver "
                         "with open connections"));
        return -1;
    }
    driver = NULL;
    return 0;
}


static int
netcfStateReload(void)
{
    int ret = -1;

    if (!driver)
        return 0;

    virObjectLock(driver);
    ncf_close(driver->netcf);
    if (ncf_init(&driver->netcf, NULL) != 0) {
        /* this isn't a good situation, because we can't shut down the
         * driver as there may still be connections to it. If we set
         * the netcf handle to NULL, any subsequent calls to netcf
         * will just fail rather than causing a crash. Not ideal, but
         * livable (since this should never happen).
         */
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("failed to re-init netcf"));
        driver->netcf = NULL;
        goto cleanup;
    }

    ret = 0;
 cleanup:
    virObjectUnlock(driver);

    return ret;
}


static virDrvOpenStatus
netcfConnectOpen(virConnectPtr conn,
                 virConnectAuthPtr auth ATTRIBUTE_UNUSED,
                 virConfPtr conf ATTRIBUTE_UNUSED,
                 unsigned int flags)
{
    virCheckFlags(VIR_CONNECT_RO, VIR_DRV_OPEN_ERROR);

    /* Verify uri was specified */
    if (conn->uri == NULL) {
        /* Only hypervisor drivers are permitted to auto-open on NULL uri */
        return VIR_DRV_OPEN_DECLINED;
    } else {
        if (STRNEQ_NULLABLE(conn->uri->scheme, "interface"))
            return VIR_DRV_OPEN_DECLINED;

        /* Leave for remote driver */
        if (conn->uri->server != NULL)
            return VIR_DRV_OPEN_DECLINED;

        if (driver == NULL) {
            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                           _("interface state driver is not active"));
            return VIR_DRV_OPEN_ERROR;
        }

        if (driver->privileged) {
            if (STRNEQ(conn->uri->path, "/system")) {
                virReportError(VIR_ERR_INTERNAL_ERROR,
                               _("unexpected interface URI path '%s', try interface:///system"),
                               conn->uri->path);
                return VIR_DRV_OPEN_ERROR;
            }
        } else {
            if (STRNEQ(conn->uri->path, "/session")) {
                virReportError(VIR_ERR_INTERNAL_ERROR,
                               _("unexpected interface URI path '%s', try interface:///session"),
                               conn->uri->path);
                return VIR_DRV_OPEN_ERROR;
            }
        }
    }

    if (virConnectOpenEnsureACL(conn) < 0)
        return VIR_DRV_OPEN_ERROR;

    return VIR_DRV_OPEN_SUCCESS;
}

static int netcfConnectClose(virConnectPtr conn ATTRIBUTE_UNUSED)
{
    return 0;
}


static int netcfConnectIsSecure(virConnectPtr conn ATTRIBUTE_UNUSED)
{
    /* Trivially secure, since always inside the daemon */
    return 1;
}


static int netcfConnectIsEncrypted(virConnectPtr conn ATTRIBUTE_UNUSED)
{
    /* Not encrypted, but remote driver takes care of that */
    return 0;
}


static int netcfConnectIsAlive(virConnectPtr conn ATTRIBUTE_UNUSED)
{
    return 1;
}


/*
 * Get a minimal virInterfaceDef containing enough metadata
 * for access control checks to be performed. Currently
 * this implies existence of name and mac address attributes
 */
static virInterfaceDef * ATTRIBUTE_NONNULL(1)
netcfGetMinimalDefForDevice(struct netcf_if *iface)
{
    virInterfaceDef *def;

    /* Allocate our interface definition structure */
    if (VIR_ALLOC(def) < 0)
        return NULL;

    if (VIR_STRDUP(def->name, ncf_if_name(iface)) < 0)
        goto cleanup;

    if (VIR_STRDUP(def->mac, ncf_if_mac_string(iface)) < 0)
        goto cleanup;

    return def;

 cleanup:
    virInterfaceDefFree(def);
    return NULL;
}


static int netcf_to_vir_err(int netcf_errcode)
{
    switch (netcf_errcode) {
        case NETCF_NOERROR:
            /* no error, everything ok */
            return VIR_ERR_OK;
        case NETCF_EINTERNAL:
            /* internal error, aka bug */
            return VIR_ERR_INTERNAL_ERROR;
        case NETCF_EOTHER:
            /* other error, copout for being more specific */
            return VIR_ERR_INTERNAL_ERROR;
        case NETCF_ENOMEM:
            /*
             * allocation failed return VIR ERR NO MEMORY
             * though it should not be used now.
             */
            return 2;
        case NETCF_EXMLPARSER:
            /* XML parser choked */
            return VIR_ERR_XML_ERROR;
        case NETCF_EXMLINVALID:
            /* XML invalid in some form */
            return VIR_ERR_XML_ERROR;
        case NETCF_ENOENT:
            /* Required entry in a tree is missing */
            return VIR_ERR_INTERNAL_ERROR;
        case NETCF_EEXEC:
            /* external program execution failed or returned non-0 */
            return VIR_ERR_INTERNAL_ERROR;
#ifdef NETCF_EINVALIDOP
        case NETCF_EINVALIDOP:
            /* attempted operation is invalid while the system is in the current state. */
            return VIR_ERR_OPERATION_INVALID;
#endif
        default:
            return VIR_ERR_INTERNAL_ERROR;
    }
}

static struct netcf_if *interfaceDriverGetNetcfIF(struct netcf *ncf, virInterfacePtr ifinfo)
{
    /* 1) caller already has lock,
     * 2) caller cleans up iface on return
     */
    struct netcf_if *iface = ncf_lookup_by_name(ncf, ifinfo->name);
    if (!iface) {
        const char *errmsg, *details;
        int errcode = ncf_error(ncf, &errmsg, &details);
        if (errcode != NETCF_NOERROR) {
            virReportError(netcf_to_vir_err(errcode),
                           _("couldn't find interface named '%s': %s%s%s"),
                           ifinfo->name, errmsg, details ? " - " : "",
                           details ? details : "");
        } else {
            virReportError(VIR_ERR_NO_INTERFACE,
                           _("couldn't find interface named '%s'"),
                           ifinfo->name);
        }
    }
    return iface;
}

static int
netcfInterfaceObjIsActive(struct netcf_if *iface,
                          bool *active)
{
    int ret = -1;
    unsigned int flags = 0;

    virObjectRef(driver);
    if (ncf_if_status(iface, &flags) < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to get status of interface %s: %s%s%s"),
                       ncf_if_name(iface), errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    *active = flags & NETCF_IFACE_ACTIVE;
    ret = 0;

 cleanup:
    virObjectUnref(driver);
    return ret;
}

static int netcfConnectNumOfInterfacesImpl(virConnectPtr conn,
                                           int status,
                                           virInterfaceObjListFilter filter)
{
    int count;
    int want = 0;
    int ret = -1;
    size_t i;
    char **names = NULL;

    /* List all interfaces, in case we might support new filter flags
     * beyond active|inactive in future.
     */
    count = ncf_num_of_interfaces(driver->netcf, status);
    if (count < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to get number of host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    if (count == 0) {
        ret = 0;
        goto cleanup;
    }

    if (VIR_ALLOC_N(names, count) < 0)
        goto cleanup;

    if ((count = ncf_list_interfaces(driver->netcf, count, names, status)) < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to list host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    for (i = 0; i < count; i++) {
        virInterfaceDefPtr def;
        struct netcf_if *iface;

        iface = ncf_lookup_by_name(driver->netcf, names[i]);
        if (!iface) {
            const char *errmsg, *details;
            int errcode = ncf_error(driver->netcf, &errmsg, &details);
            if (errcode != NETCF_NOERROR) {
                virReportError(netcf_to_vir_err(errcode),
                               _("couldn't find interface named '%s': %s%s%s"),
                               names[i], errmsg,
                               details ? " - " : "", details ? details : "");
                goto cleanup;
            } else {
                /* Ignore the NETCF_NOERROR, as the interface is very likely
                 * deleted by other management apps (e.g. virt-manager).
                 */
                VIR_WARN("couldn't find interface named '%s', might be "
                         "deleted by other process", names[i]);
                continue;
            }
        }

        if (!(def = netcfGetMinimalDefForDevice(iface))) {
            ncf_if_free(iface);
            goto cleanup;
        }
        ncf_if_free(iface);

        if (!filter(conn, def)) {
            virInterfaceDefFree(def);
            continue;
        }
        virInterfaceDefFree(def);

        want++;
    }

    ret = want;

 cleanup:
    if (names && count > 0)
        for (i = 0; i < count; i++)
            VIR_FREE(names[i]);
    VIR_FREE(names);
    return ret;
}


static int netcfConnectListInterfacesImpl(virConnectPtr conn,
                                          int status,
                                          char **const names, int nnames,
                                          virInterfaceObjListFilter filter)
{
    int count = 0;
    int want = 0;
    int ret = -1;
    size_t i;
    char **allnames = NULL;

    count = ncf_num_of_interfaces(driver->netcf, status);
    if (count < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to get number of host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    if (count == 0) {
        ret = 0;
        goto cleanup;
    }

    if (VIR_ALLOC_N(allnames, count) < 0)
        goto cleanup;

    if ((count = ncf_list_interfaces(driver->netcf, count, allnames, status)) < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to list host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    if (count == 0) {
        ret = 0;
        goto cleanup;
    }

    for (i = 0; i < count && want < nnames; i++) {
        virInterfaceDefPtr def;
        struct netcf_if *iface;

        iface = ncf_lookup_by_name(driver->netcf, allnames[i]);
        if (!iface) {
            const char *errmsg, *details;
            int errcode = ncf_error(driver->netcf, &errmsg, &details);
            if (errcode != NETCF_NOERROR) {
                virReportError(netcf_to_vir_err(errcode),
                               _("couldn't find interface named '%s': %s%s%s"),
                               allnames[i], errmsg,
                               details ? " - " : "", details ? details : "");
                goto cleanup;
            } else {
                /* Ignore the NETCF_NOERROR, as the interface is very likely
                 * deleted by other management apps (e.g. virt-manager).
                 */
                VIR_WARN("couldn't find interface named '%s', might be "
                         "deleted by other process", allnames[i]);
                continue;
            }
        }

        if (!(def = netcfGetMinimalDefForDevice(iface))) {
            ncf_if_free(iface);
            goto cleanup;
        }
        ncf_if_free(iface);

        if (!filter(conn, def)) {
            virInterfaceDefFree(def);
            continue;
        }
        virInterfaceDefFree(def);

        names[want++] = allnames[i];
        allnames[i] = NULL;
    }

    ret = want;

 cleanup:
    if (allnames && count > 0)
        for (i = 0; i < count; i++)
            VIR_FREE(allnames[i]);
    VIR_FREE(allnames);
    if (ret < 0) {
        for (i = 0; i < nnames; i++)
            VIR_FREE(names[i]);
    }
    return ret;
}


static int netcfConnectNumOfInterfaces(virConnectPtr conn)
{
    int count;

    if (virConnectNumOfInterfacesEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);
    count = netcfConnectNumOfInterfacesImpl(conn,
                                            NETCF_IFACE_ACTIVE,
                                            virConnectNumOfInterfacesCheckACL);
    virObjectUnlock(driver);
    return count;
}

static int netcfConnectListInterfaces(virConnectPtr conn, char **const names, int nnames)
{
    int count;

    if (virConnectListInterfacesEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);
    count = netcfConnectListInterfacesImpl(conn,
                                           NETCF_IFACE_ACTIVE,
                                           names, nnames,
                                           virConnectListInterfacesCheckACL);
    virObjectUnlock(driver);
    return count;

}

static int netcfConnectNumOfDefinedInterfaces(virConnectPtr conn)
{
    int count;

    if (virConnectNumOfDefinedInterfacesEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);
    count = netcfConnectNumOfInterfacesImpl(conn,
                                            NETCF_IFACE_INACTIVE,
                                            virConnectNumOfDefinedInterfacesCheckACL);
    virObjectUnlock(driver);
    return count;
}

static int netcfConnectListDefinedInterfaces(virConnectPtr conn, char **const names, int nnames)
{
    int count;

    if (virConnectListDefinedInterfacesEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);
    count = netcfConnectListInterfacesImpl(conn,
                                           NETCF_IFACE_INACTIVE,
                                           names, nnames,
                                           virConnectListDefinedInterfacesCheckACL);
    virObjectUnlock(driver);
    return count;

}

#define MATCH(FLAG) (flags & (FLAG))
static int
netcfConnectListAllInterfaces(virConnectPtr conn,
                              virInterfacePtr **ifaces,
                              unsigned int flags)
{
    int count;
    size_t i;
    unsigned int ncf_flags = 0;
    struct netcf_if *iface = NULL;
    virInterfacePtr *tmp_iface_objs = NULL;
    virInterfacePtr iface_obj = NULL;
    int niface_objs = 0;
    int ret = -1;
    char **names = NULL;

    virCheckFlags(VIR_CONNECT_LIST_INTERFACES_FILTERS_ACTIVE, -1);

    if (virConnectListAllInterfacesEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);

    /* let netcf pre-filter for this flag to save time */
    if (MATCH(VIR_CONNECT_LIST_INTERFACES_FILTERS_ACTIVE)) {
        if (MATCH(VIR_CONNECT_LIST_INTERFACES_ACTIVE))
            ncf_flags |= NETCF_IFACE_ACTIVE;
        if (MATCH(VIR_CONNECT_LIST_INTERFACES_INACTIVE))
            ncf_flags |= NETCF_IFACE_INACTIVE;
    } else {
        ncf_flags = NETCF_IFACE_ACTIVE | NETCF_IFACE_INACTIVE;
    }

    if ((count = ncf_num_of_interfaces(driver->netcf, ncf_flags)) < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);

        virReportError(netcf_to_vir_err(errcode),
                       _("failed to get number of host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    if (count == 0) {
        ret = 0;
        goto cleanup;
    }

    if (VIR_ALLOC_N(names, count) < 0)
        goto cleanup;

    if ((count = ncf_list_interfaces(driver->netcf, count,
                                     names, ncf_flags)) < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);

        virReportError(netcf_to_vir_err(errcode),
                       _("failed to list host interfaces: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    if (ifaces && VIR_ALLOC_N(tmp_iface_objs, count + 1) < 0)
        goto cleanup;

    for (i = 0; i < count; i++) {
        virInterfaceDefPtr def;

        iface = ncf_lookup_by_name(driver->netcf, names[i]);
        if (!iface) {
            const char *errmsg, *details;
            int errcode = ncf_error(driver->netcf, &errmsg, &details);
            if (errcode != NETCF_NOERROR) {
                virReportError(netcf_to_vir_err(errcode),
                               _("couldn't find interface named '%s': %s%s%s"),
                               names[i], errmsg,
                               details ? " - " : "", details ? details : "");
                goto cleanup;
            } else {
                /* Ignore the NETCF_NOERROR, as the interface is very likely
                 * deleted by other management apps (e.g. virt-manager).
                 */
                VIR_WARN("couldn't find interface named '%s', might be "
                         "deleted by other process", names[i]);
                continue;
            }
        }

        if (!(def = netcfGetMinimalDefForDevice(iface)))
            goto cleanup;

        if (!virConnectListAllInterfacesCheckACL(conn, def)) {
            ncf_if_free(iface);
            iface = NULL;
            virInterfaceDefFree(def);
            continue;
        }

        if (ifaces) {
            if (!(iface_obj = virGetInterface(conn, def->name, def->mac))) {
                virInterfaceDefFree(def);
                goto cleanup;
            }
            tmp_iface_objs[niface_objs] = iface_obj;
        }
        niface_objs++;

        virInterfaceDefFree(def);
        ncf_if_free(iface);
        iface = NULL;
    }

    if (tmp_iface_objs) {
        /* trim the array to the final size */
        ignore_value(VIR_REALLOC_N(tmp_iface_objs, niface_objs + 1));
        *ifaces = tmp_iface_objs;
        tmp_iface_objs = NULL;
    }

    ret = niface_objs;

 cleanup:
    ncf_if_free(iface);

    if (names && count > 0)
        for (i = 0; i < count; i++)
            VIR_FREE(names[i]);
    VIR_FREE(names);

    if (tmp_iface_objs) {
        for (i = 0; i < niface_objs; i++)
            virObjectUnref(tmp_iface_objs[i]);
        VIR_FREE(tmp_iface_objs);
    }

    virObjectUnlock(driver);
    return ret;
}


static virInterfacePtr netcfInterfaceLookupByName(virConnectPtr conn,
                                                  const char *name)
{
    struct netcf_if *iface;
    virInterfacePtr ret = NULL;
    virInterfaceDefPtr def = NULL;

    virObjectLock(driver);
    iface = ncf_lookup_by_name(driver->netcf, name);
    if (!iface) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        if (errcode != NETCF_NOERROR) {
            virReportError(netcf_to_vir_err(errcode),
                           _("couldn't find interface named '%s': %s%s%s"),
                           name, errmsg,
                           details ? " - " : "", details ? details : "");
        } else {
            virReportError(VIR_ERR_NO_INTERFACE,
                           _("couldn't find interface named '%s'"), name);
        }
        goto cleanup;
    }

    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceLookupByNameEnsureACL(conn, def) < 0)
       goto cleanup;

    ret = virGetInterface(conn, def->name, def->mac);

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

static virInterfacePtr netcfInterfaceLookupByMACString(virConnectPtr conn,
                                                       const char *macstr)
{
    struct netcf_if *iface;
    int niface;
    virInterfacePtr ret = NULL;
    virInterfaceDefPtr def = NULL;

    virObjectLock(driver);
    niface = ncf_lookup_by_mac_string(driver->netcf, macstr, 1, &iface);

    if (niface < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("couldn't find interface with MAC address '%s': %s%s%s"),
                       macstr, errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }
    if (niface == 0) {
        virReportError(VIR_ERR_NO_INTERFACE,
                       _("couldn't find interface with MAC address '%s'"),
                       macstr);
        goto cleanup;
    }
    if (niface > 1) {
        virReportError(VIR_ERR_MULTIPLE_INTERFACES,
                       "%s", _("multiple interfaces with matching MAC address"));
        goto cleanup;
    }


    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceLookupByMACStringEnsureACL(conn, def) < 0)
       goto cleanup;

    ret = virGetInterface(conn, def->name, def->mac);

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

static char *netcfInterfaceGetXMLDesc(virInterfacePtr ifinfo,
                                      unsigned int flags)
{
    struct netcf_if *iface = NULL;
    char *xmlstr = NULL;
    virInterfaceDefPtr ifacedef = NULL;
    char *ret = NULL;
    bool active;

    virCheckFlags(VIR_INTERFACE_XML_INACTIVE, NULL);

    virObjectLock(driver);

    iface = interfaceDriverGetNetcfIF(driver->netcf, ifinfo);
    if (!iface) {
        /* helper already reported error */
        goto cleanup;
    }

    if (netcfInterfaceObjIsActive(iface, &active) < 0)
       goto cleanup;

    if ((flags & VIR_INTERFACE_XML_INACTIVE) || !active) {
        xmlstr = ncf_if_xml_desc(iface);
    } else {
        xmlstr = ncf_if_xml_state(iface);
    }
    if (!xmlstr) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("could not get interface XML description: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    ifacedef = virInterfaceDefParseString(xmlstr);
    if (!ifacedef) {
        /* error was already reported */
        goto cleanup;
    }

    if (virInterfaceGetXMLDescEnsureACL(ifinfo->conn, ifacedef) < 0)
        goto cleanup;

    ret = virInterfaceDefFormat(ifacedef);
    if (!ret) {
        /* error was already reported */
        goto cleanup;
    }

 cleanup:
    ncf_if_free(iface);
    VIR_FREE(xmlstr);
    virInterfaceDefFree(ifacedef);
    virObjectUnlock(driver);
    return ret;
}

static virInterfacePtr netcfInterfaceDefineXML(virConnectPtr conn,
                                               const char *xml,
                                               unsigned int flags)
{
    struct netcf_if *iface = NULL;
    char *xmlstr = NULL;
    virInterfaceDefPtr ifacedef = NULL;
    virInterfacePtr ret = NULL;

    virCheckFlags(0, NULL);

    virObjectLock(driver);

    ifacedef = virInterfaceDefParseString(xml);
    if (!ifacedef) {
        /* error was already reported */
        goto cleanup;
    }

    if (virInterfaceDefineXMLEnsureACL(conn, ifacedef) < 0)
        goto cleanup;

    xmlstr = virInterfaceDefFormat(ifacedef);
    if (!xmlstr) {
        /* error was already reported */
        goto cleanup;
    }

    iface = ncf_define(driver->netcf, xmlstr);
    if (!iface) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("could not get interface XML description: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

    ret = virGetInterface(conn, ncf_if_name(iface), ncf_if_mac_string(iface));

 cleanup:
    ncf_if_free(iface);
    VIR_FREE(xmlstr);
    virInterfaceDefFree(ifacedef);
    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceUndefine(virInterfacePtr ifinfo)
{
    struct netcf_if *iface = NULL;
    virInterfaceDefPtr def = NULL;
    int ret = -1;

    virObjectLock(driver);

    iface = interfaceDriverGetNetcfIF(driver->netcf, ifinfo);
    if (!iface) {
        /* helper already reported error */
        goto cleanup;
    }


    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceUndefineEnsureACL(ifinfo->conn, def) < 0)
       goto cleanup;

    ret = ncf_if_undefine(iface);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to undefine interface %s: %s%s%s"),
                       ifinfo->name, errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceCreate(virInterfacePtr ifinfo,
                                unsigned int flags)
{
    struct netcf_if *iface = NULL;
    virInterfaceDefPtr def = NULL;
    int ret = -1;
    bool active;

    virCheckFlags(0, -1);

    virObjectLock(driver);

    iface = interfaceDriverGetNetcfIF(driver->netcf, ifinfo);
    if (!iface) {
        /* helper already reported error */
        goto cleanup;
    }


    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceCreateEnsureACL(ifinfo->conn, def) < 0)
       goto cleanup;

    if (netcfInterfaceObjIsActive(iface, &active) < 0)
        goto cleanup;

    if (active) {
        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                       _("interface is already running"));
        goto cleanup;
    }

    ret = ncf_if_up(iface);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to create (start) interface %s: %s%s%s"),
                       ifinfo->name, errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceDestroy(virInterfacePtr ifinfo,
                                 unsigned int flags)
{
    struct netcf_if *iface = NULL;
    virInterfaceDefPtr def = NULL;
    int ret = -1;
    bool active;

    virCheckFlags(0, -1);

    virObjectLock(driver);

    iface = interfaceDriverGetNetcfIF(driver->netcf, ifinfo);
    if (!iface) {
        /* helper already reported error */
        goto cleanup;
    }


    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceDestroyEnsureACL(ifinfo->conn, def) < 0)
       goto cleanup;

    if (netcfInterfaceObjIsActive(iface, &active) < 0)
        goto cleanup;

    if (!active) {
        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                       _("interface is not running"));
        goto cleanup;
    }

    ret = ncf_if_down(iface);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to destroy (stop) interface %s: %s%s%s"),
                       ifinfo->name, errmsg, details ? " - " : "",
                       details ? details : "");
        goto cleanup;
    }

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceIsActive(virInterfacePtr ifinfo)
{
    struct netcf_if *iface = NULL;
    virInterfaceDefPtr def = NULL;
    int ret = -1;
    bool active;

    virObjectLock(driver);

    iface = interfaceDriverGetNetcfIF(driver->netcf, ifinfo);
    if (!iface) {
        /* helper already reported error */
        goto cleanup;
    }

    if (!(def = netcfGetMinimalDefForDevice(iface)))
        goto cleanup;

    if (virInterfaceIsActiveEnsureACL(ifinfo->conn, def) < 0)
       goto cleanup;

    if (netcfInterfaceObjIsActive(iface, &active) < 0)
        goto cleanup;

    ret = active ? 1 : 0;

 cleanup:
    ncf_if_free(iface);
    virInterfaceDefFree(def);
    virObjectUnlock(driver);
    return ret;
}

#ifdef HAVE_NETCF_TRANSACTIONS
static int netcfInterfaceChangeBegin(virConnectPtr conn, unsigned int flags)
{
    int ret;

    virCheckFlags(0, -1); /* currently flags must be 0 */

    if (virInterfaceChangeBeginEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);

    ret = ncf_change_begin(driver->netcf, 0);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to begin transaction: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
    }

    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceChangeCommit(virConnectPtr conn, unsigned int flags)
{
    int ret;

    virCheckFlags(0, -1); /* currently flags must be 0 */

    if (virInterfaceChangeCommitEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);

    ret = ncf_change_commit(driver->netcf, 0);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to commit transaction: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
    }

    virObjectUnlock(driver);
    return ret;
}

static int netcfInterfaceChangeRollback(virConnectPtr conn, unsigned int flags)
{
    int ret;

    virCheckFlags(0, -1); /* currently flags must be 0 */

    if (virInterfaceChangeRollbackEnsureACL(conn) < 0)
        return -1;

    virObjectLock(driver);

    ret = ncf_change_rollback(driver->netcf, 0);
    if (ret < 0) {
        const char *errmsg, *details;
        int errcode = ncf_error(driver->netcf, &errmsg, &details);
        virReportError(netcf_to_vir_err(errcode),
                       _("failed to rollback transaction: %s%s%s"),
                       errmsg, details ? " - " : "",
                       details ? details : "");
    }

    virObjectUnlock(driver);
    return ret;
}
#endif /* HAVE_NETCF_TRANSACTIONS */

static virInterfaceDriver interfaceDriver = {
    .name = INTERFACE_DRIVER_NAME,
    .connectNumOfInterfaces = netcfConnectNumOfInterfaces, /* 0.7.0 */
    .connectListInterfaces = netcfConnectListInterfaces, /* 0.7.0 */
    .connectNumOfDefinedInterfaces = netcfConnectNumOfDefinedInterfaces, /* 0.7.0 */
    .connectListDefinedInterfaces = netcfConnectListDefinedInterfaces, /* 0.7.0 */
    .connectListAllInterfaces = netcfConnectListAllInterfaces, /* 0.10.2 */
    .interfaceLookupByName = netcfInterfaceLookupByName, /* 0.7.0 */
    .interfaceLookupByMACString = netcfInterfaceLookupByMACString, /* 0.7.0 */
    .interfaceGetXMLDesc = netcfInterfaceGetXMLDesc, /* 0.7.0 */
    .interfaceDefineXML = netcfInterfaceDefineXML, /* 0.7.0 */
    .interfaceUndefine = netcfInterfaceUndefine, /* 0.7.0 */
    .interfaceCreate = netcfInterfaceCreate, /* 0.7.0 */
    .interfaceDestroy = netcfInterfaceDestroy, /* 0.7.0 */
    .interfaceIsActive = netcfInterfaceIsActive, /* 0.7.3 */
#ifdef HAVE_NETCF_TRANSACTIONS
    .interfaceChangeBegin = netcfInterfaceChangeBegin, /* 0.9.2 */
    .interfaceChangeCommit = netcfInterfaceChangeCommit, /* 0.9.2 */
    .interfaceChangeRollback = netcfInterfaceChangeRollback, /* 0.9.2 */
#endif /* HAVE_NETCF_TRANSACTIONS */
};


static virHypervisorDriver interfaceHypervisorDriver = {
    .name = "interface",
    .connectOpen = netcfConnectOpen, /* 4.1.0 */
    .connectClose = netcfConnectClose, /* 4.1.0 */
    .connectIsEncrypted = netcfConnectIsEncrypted, /* 4.1.0 */
    .connectIsSecure = netcfConnectIsSecure, /* 4.1.0 */
    .connectIsAlive = netcfConnectIsAlive, /* 4.1.0 */
};


static virConnectDriver interfaceConnectDriver = {
    .hypervisorDriver = &interfaceHypervisorDriver,
    .interfaceDriver = &interfaceDriver,
};


static virStateDriver interfaceStateDriver = {
    .name = INTERFACE_DRIVER_NAME,
    .stateInitialize = netcfStateInitialize,
    .stateCleanup = netcfStateCleanup,
    .stateReload = netcfStateReload,
};

int netcfIfaceRegister(void)
{
    if (virRegisterConnectDriver(&interfaceConnectDriver, false) < 0)
        return -1;
    if (virSetSharedInterfaceDriver(&interfaceDriver) < 0)
        return -1;
    if (virRegisterStateDriver(&interfaceStateDriver) < 0)
        return -1;
    return 0;
}