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mirror of https://gitlab.com/libvirt/libvirt.git synced 2024-12-23 21:34:54 +03:00
libvirt/tools/virsh-util.c
Daniel P. Berrangé 8615c19b5d tools: add helper method for printing an XML document
The trivial case of fully printing an XML document is boring, but
this helper does more by allowing an XPath expression to be given.
It will then print just the subset of nodes which match the
expression. It either print each match as a standalone XML doc
or can put them into one new XML doc wrapped woith <nodes>...</nodes>

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2022-06-20 10:40:34 +01:00

498 lines
12 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 "virxml.h"
static virDomainPtr
virshLookupDomainInternal(vshControl *ctl,
const char *cmdname,
const char *name,
unsigned int flags)
{
virDomainPtr dom = NULL;
int id;
virshControl *priv = ctl->privData;
virCheckFlags(VIRSH_BYID | VIRSH_BYUUID | VIRSH_BYNAME, NULL);
/* 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;
virshControl *priv = ctl->privData;
if (reason)
*reason = -1;
if (!priv->useGetInfo) {
int state;
if (virDomainGetState(dom, &state, reason, 0) < 0) {
if (virGetLastErrorCode() == 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;
return info.state;
}
int
virshStreamSink(virStreamPtr st G_GNUC_UNUSED,
const char *bytes,
size_t nbytes,
void *opaque)
{
virshStreamCallbackData *cbData = opaque;
return safewrite(cbData->fd, bytes, nbytes);
}
int
virshStreamSource(virStreamPtr st G_GNUC_UNUSED,
char *bytes,
size_t nbytes,
void *opaque)
{
virshStreamCallbackData *cbData = opaque;
int fd = cbData->fd;
return saferead(fd, bytes, nbytes);
}
int
virshStreamSourceSkip(virStreamPtr st G_GNUC_UNUSED,
long long offset,
void *opaque)
{
virshStreamCallbackData *cbData = opaque;
int fd = cbData->fd;
if (lseek(fd, offset, SEEK_CUR) == (off_t) -1)
return -1;
return 0;
}
int
virshStreamSkip(virStreamPtr st G_GNUC_UNUSED,
long long offset,
void *opaque)
{
virshStreamCallbackData *cbData = opaque;
off_t cur;
if (cbData->isBlock) {
g_autofree char * buf = NULL;
const size_t buflen = 1 * 1024 * 1024; /* 1MiB */
/* While for files it's enough to lseek() and ftruncate() to create
* a hole which would emulate zeroes on read(), for block devices
* we have to write zeroes to read() zeroes. And we have to write
* @got bytes of zeroes. Do that in smaller chunks though.*/
buf = g_new0(char, buflen);
while (offset) {
size_t count = MIN(offset, buflen);
ssize_t r;
if ((r = safewrite(cbData->fd, buf, count)) < 0)
return -1;
offset -= r;
}
} else {
if ((cur = lseek(cbData->fd, offset, SEEK_CUR)) == (off_t) -1)
return -1;
if (ftruncate(cbData->fd, cur) < 0)
return -1;
}
return 0;
}
int
virshStreamInData(virStreamPtr st G_GNUC_UNUSED,
int *inData,
long long *offset,
void *opaque)
{
virshStreamCallbackData *cbData = opaque;
vshControl *ctl = cbData->ctl;
int fd = cbData->fd;
if (cbData->isBlock) {
/* Block devices are always in data section by definition. The
* @sectionLen is slightly more tricky. While we could try and get
* how much bytes is there left until EOF, we can pretend there is
* always X bytes left and let the saferead() below hit EOF (which
* is then handled gracefully anyway). Worst case scenario, this
* branch is called more than once.
* X was chosen to be 1MiB but it has ho special meaning. */
*inData = 1;
*offset = 1 * 1024 * 1024;
} else {
if (virFileInData(fd, inData, offset) < 0) {
vshError(ctl, "%s", _("Unable to get current position in stream"));
return -1;
}
}
return 0;
}
void
virshDomainFree(virDomainPtr dom)
{
if (!dom)
return;
vshSaveLibvirtHelperError();
virDomainFree(dom); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshDomainCheckpointFree(virDomainCheckpointPtr chk)
{
if (!chk)
return;
vshSaveLibvirtHelperError();
virDomainCheckpointFree(chk); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshDomainSnapshotFree(virDomainSnapshotPtr snap)
{
if (!snap)
return;
vshSaveLibvirtHelperError();
virDomainSnapshotFree(snap); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshInterfaceFree(virInterfacePtr iface)
{
if (!iface)
return;
vshSaveLibvirtHelperError();
virInterfaceFree(iface); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshNetworkFree(virNetworkPtr network)
{
if (!network)
return;
vshSaveLibvirtHelperError();
virNetworkFree(network); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshNodeDeviceFree(virNodeDevicePtr device)
{
if (!device)
return;
vshSaveLibvirtHelperError();
virNodeDeviceFree(device); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshNWFilterFree(virNWFilterPtr nwfilter)
{
if (!nwfilter)
return;
vshSaveLibvirtHelperError();
virNWFilterFree(nwfilter); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshSecretFree(virSecretPtr secret)
{
if (!secret)
return;
vshSaveLibvirtHelperError();
virSecretFree(secret); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshStoragePoolFree(virStoragePoolPtr pool)
{
if (!pool)
return;
vshSaveLibvirtHelperError();
virStoragePoolFree(pool); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshStorageVolFree(virStorageVolPtr vol)
{
if (!vol)
return;
vshSaveLibvirtHelperError();
virStorageVolFree(vol); /* sc_prohibit_obj_free_apis_in_virsh */
}
void
virshStreamFree(virStreamPtr stream)
{
if (!stream)
return;
vshSaveLibvirtHelperError();
virStreamFree(stream); /* sc_prohibit_obj_free_apis_in_virsh */
}
int
virshDomainGetXMLFromDom(vshControl *ctl,
virDomainPtr dom,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
{
g_autofree char *desc = NULL;
if (!(desc = virDomainGetXMLDesc(dom, flags))) {
vshError(ctl, _("Failed to get domain description xml"));
return -1;
}
*xml = virXMLParseStringCtxt(desc, _("(domain_definition)"), ctxt);
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;
}
VIR_ENUM_IMPL(virshDomainBlockJob,
VIR_DOMAIN_BLOCK_JOB_TYPE_LAST,
N_("Unknown job"),
N_("Block Pull"),
N_("Block Copy"),
N_("Block Commit"),
N_("Active Block Commit"),
N_("Backup"),
);
const char *
virshDomainBlockJobToString(int type)
{
const char *str = virshDomainBlockJobTypeToString(type);
return str ? _(str) : _("Unknown job");
}
bool
virshDumpXML(vshControl *ctl,
const char *xml,
const char *url,
const char *xpath,
bool wrap)
{
g_autoptr(xmlDoc) doc = NULL;
g_autoptr(xmlXPathContext) ctxt = NULL;
g_autofree xmlNodePtr *nodes = NULL;
int nnodes = 0;
size_t i;
int oldblanks;
if (xpath == NULL) {
vshPrint(ctl, "%s", xml);
return true;
}
oldblanks = xmlKeepBlanksDefault(0);
doc = virXMLParseString(xml, url);
xmlKeepBlanksDefault(oldblanks);
if (!doc)
return false;
if (!(ctxt = virXMLXPathContextNew(doc)))
return false;
if ((nnodes = virXPathNodeSet(xpath, ctxt, &nodes)) < 0) {
return false;
}
if (wrap) {
g_autoptr(xmlDoc) newdoc = xmlNewDoc((xmlChar *)"1.0");
xmlNodePtr newroot = xmlNewNode(NULL, (xmlChar *)"nodes");
g_autofree char *xmlbit = NULL;
xmlDocSetRootElement(newdoc, newroot);
for (i = 0; i < nnodes; i++) {
g_autoptr(xmlNode) copy = xmlDocCopyNode(nodes[i], newdoc, 1);
if (!xmlAddChild(newroot, copy))
return false;
copy = NULL;
}
xmlbit = virXMLNodeToString(doc, newroot);
vshPrint(ctl, "%s\n", xmlbit);
} else {
for (i = 0; i < nnodes; i++) {
g_autofree char *xmlbit = virXMLNodeToString(doc, nodes[i]);
vshPrint(ctl, "%s\n", xmlbit);
}
}
return true;
}