libvirt/tools/virsh-util.c
Peter Krempa c8a637c7d0 virsh: add helpers for getting domain XML for XPath purposes
In virsh we quite often get the domain XML just to initialize the XPath
parser so that we can extract information.

Add helpers which will simplify this by wrapping the getting of the XML
and parsing it along with error reporting.

Additionally a second helper also gets the domain object from the
parameters and releases it so that functions which need the XML as only
source of data can be simplified further.
2017-04-12 14:12:56 +02:00

223 lines
5.4 KiB
C

/*
* virsh-util.c: helpers for virsh
*
* 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/>.
*/
#include <config.h>
#include "virsh-util.h"
#include "virfile.h"
#include "virstring.h"
#include "viralloc.h"
static virDomainPtr
virshLookupDomainInternal(vshControl *ctl,
const char *cmdname,
const char *name,
unsigned int flags)
{
virDomainPtr dom = NULL;
int id;
virCheckFlags(VIRSH_BYID | VIRSH_BYUUID | VIRSH_BYNAME, NULL);
virshControlPtr priv = ctl->privData;
/* try it by ID */
if (flags & VIRSH_BYID) {
if (virStrToLong_i(name, NULL, 10, &id) == 0 && id >= 0) {
vshDebug(ctl, VSH_ERR_DEBUG, "%s: <domain> looks like ID\n",
cmdname);
dom = virDomainLookupByID(priv->conn, id);
}
}
/* try it by UUID */
if (!dom && (flags & VIRSH_BYUUID) &&
strlen(name) == VIR_UUID_STRING_BUFLEN-1) {
vshDebug(ctl, VSH_ERR_DEBUG, "%s: <domain> trying as domain UUID\n",
cmdname);
dom = virDomainLookupByUUIDString(priv->conn, name);
}
/* try it by NAME */
if (!dom && (flags & VIRSH_BYNAME)) {
vshDebug(ctl, VSH_ERR_DEBUG, "%s: <domain> trying as domain NAME\n",
cmdname);
dom = virDomainLookupByName(priv->conn, name);
}
vshResetLibvirtError();
if (!dom)
vshError(ctl, _("failed to get domain '%s'"), name);
return dom;
}
virDomainPtr
virshLookupDomainBy(vshControl *ctl,
const char *name,
unsigned int flags)
{
return virshLookupDomainInternal(ctl, "unknown", name, flags);
}
virDomainPtr
virshCommandOptDomainBy(vshControl *ctl,
const vshCmd *cmd,
const char **name,
unsigned int flags)
{
const char *n = NULL;
const char *optname = "domain";
if (vshCommandOptStringReq(ctl, cmd, optname, &n) < 0)
return NULL;
vshDebug(ctl, VSH_ERR_INFO, "%s: found option <%s>: %s\n",
cmd->def->name, optname, n);
if (name)
*name = n;
return virshLookupDomainInternal(ctl, cmd->def->name, n, flags);
}
virDomainPtr
virshCommandOptDomain(vshControl *ctl,
const vshCmd *cmd,
const char **name)
{
return virshCommandOptDomainBy(ctl, cmd, name,
VIRSH_BYID | VIRSH_BYUUID | VIRSH_BYNAME);
}
int
virshDomainState(vshControl *ctl,
virDomainPtr dom,
int *reason)
{
virDomainInfo info;
virshControlPtr priv = ctl->privData;
if (reason)
*reason = -1;
if (!priv->useGetInfo) {
int state;
if (virDomainGetState(dom, &state, reason, 0) < 0) {
virErrorPtr err = virGetLastError();
if (err && err->code == VIR_ERR_NO_SUPPORT)
priv->useGetInfo = true;
else
return -1;
} else {
return state;
}
}
/* fall back to virDomainGetInfo if virDomainGetState is not supported */
if (virDomainGetInfo(dom, &info) < 0)
return -1;
else
return info.state;
}
int
virshStreamSink(virStreamPtr st ATTRIBUTE_UNUSED,
const char *bytes,
size_t nbytes,
void *opaque)
{
int *fd = opaque;
return safewrite(*fd, bytes, nbytes);
}
void
virshDomainFree(virDomainPtr dom)
{
if (!dom)
return;
vshSaveLibvirtHelperError();
virDomainFree(dom); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshDomainSnapshotFree(virDomainSnapshotPtr snap)
{
if (!snap)
return;
vshSaveLibvirtHelperError();
virDomainSnapshotFree(snap); /* sc_prohibit_obj_free_apis_in_virsh */
}
int
virshDomainGetXMLFromDom(vshControl *ctl,
virDomainPtr dom,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
{
char *desc = NULL;
if (!(desc = virDomainGetXMLDesc(dom, flags))) {
vshError(ctl, _("Failed to get domain description xml"));
return -1;
}
*xml = virXMLParseStringCtxt(desc, _("(domain_definition)"), ctxt);
VIR_FREE(desc);
if (!(*xml)) {
vshError(ctl, _("Failed to parse domain description xml"));
return -1;
}
return 0;
}
int
virshDomainGetXML(vshControl *ctl,
const vshCmd *cmd,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
{
virDomainPtr dom;
int ret;
if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
return -1;
ret = virshDomainGetXMLFromDom(ctl, dom, flags, xml, ctxt);
virshDomainFree(dom);
return ret;
}