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/* guestfish - the filesystem interactive shell
* Copyright (C) 2010 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <libvirt/libvirt.h>
#include <libvirt/virterror.h>
#include <libxml/xpath.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include "fish.h"
/* Implements the guts of the '-d' option.
*
* Note that we have to observe the '--ro' flag in two respects: by
* adding the drives read-only if the flag is set, and by restricting
* guests to shut down ones unless '--ro' is set.
*
* Returns the number of drives added (> 0), or -1 for failure.
*/
int
add_libvirt_drives (const char *guest)
{
static int initialized = 0;
if (!initialized) {
initialized = 1;
if (virInitialize () == -1)
return -1;
xmlInitParser ();
LIBXML_TEST_VERSION;
}
int r = -1, nr_added = 0, i;
virErrorPtr err;
virConnectPtr conn = NULL;
virDomainPtr dom = NULL;
xmlDocPtr doc = NULL;
xmlXPathContextPtr xpathCtx = NULL;
xmlXPathObjectPtr xpathObj = NULL;
char *xml = NULL;
/* Connect to libvirt, find the domain. */
conn = virConnectOpenReadOnly (libvirt_uri);
if (!conn) {
err = virGetLastError ();
fprintf (stderr, _("guestfish: could not connect to libvirt (code %d, domain %d): %s\n"),
err->code, err->domain, err->message);
goto cleanup;
}
dom = virDomainLookupByName (conn, guest);
if (!dom) {
err = virConnGetLastError (conn);
fprintf (stderr, _("guestfish: no libvirt domain called '%s': %s\n"),
guest, err->message);
goto cleanup;
}
if (!read_only) {
virDomainInfo info;
if (virDomainGetInfo (dom, &info) == -1) {
err = virConnGetLastError (conn);
fprintf (stderr, _("guestfish: error getting domain info about '%s': %s\n"),
guest, err->message);
goto cleanup;
}
if (info.state != VIR_DOMAIN_SHUTOFF) {
fprintf (stderr, _("guestfish: error: '%s' is a live virtual machine.\nYou must use '--ro' because write access to a running virtual machine can\ncause disk corruption.\n"),
guest);
goto cleanup;
}
}
/* Domain XML. */
xml = virDomainGetXMLDesc (dom, 0);
if (!xml) {
err = virConnGetLastError (conn);
fprintf (stderr, _("guestfish: error reading libvirt XML information about '%s': %s\n"),
guest, err->message);
goto cleanup;
}
/* Now the horrible task of parsing out the fields we need from the XML.
* http://www.xmlsoft.org/examples/xpath1.c
*/
doc = xmlParseMemory (xml, strlen (xml));
if (doc == NULL) {
fprintf (stderr, _("guestfish: unable to parse XML information returned by libvirt\n"));
goto cleanup;
}
xpathCtx = xmlXPathNewContext (doc);
if (xpathCtx == NULL) {
fprintf (stderr, _("guestfish: unable to create new XPath context\n"));
goto cleanup;
}
/* This gives us a set of all the <disk> nodes. */
xpathObj = xmlXPathEvalExpression (BAD_CAST "//devices/disk", xpathCtx);
if (xpathObj == NULL) {
fprintf (stderr, _("guestfish: unable to evaluate XPath expression\n"));
goto cleanup;
}
xmlNodeSetPtr nodes = xpathObj->nodesetval;
for (i = 0; i < nodes->nodeNr; ++i) {
xmlXPathObjectPtr xpfilename;
xmlXPathObjectPtr xpformat;
/* Change the context to the current <disk> node.
* DV advises to reset this before each search since older versions of
* libxml2 might overwrite it.
*/
xpathCtx->node = nodes->nodeTab[i];
/* Filename can be in <source dev=..> or <source file=..> attribute. */
xpfilename = xmlXPathEvalExpression (BAD_CAST "./source/@dev", xpathCtx);
if (xpfilename == NULL ||
xpfilename->nodesetval == NULL ||
xpfilename->nodesetval->nodeNr == 0) {
xmlXPathFreeObject (xpfilename);
xpathCtx->node = nodes->nodeTab[i];
xpfilename = xmlXPathEvalExpression (BAD_CAST "./source/@file", xpathCtx);
if (xpfilename == NULL ||
xpfilename->nodesetval == NULL ||
xpfilename->nodesetval->nodeNr == 0) {
xmlXPathFreeObject (xpfilename);
continue; /* disk filename not found, skip this */
}
}
assert (xpfilename->nodesetval->nodeTab[0]);
assert (xpfilename->nodesetval->nodeTab[0]->type == XML_ATTRIBUTE_NODE);
xmlAttrPtr attr = (xmlAttrPtr) xpfilename->nodesetval->nodeTab[0];
char *filename = (char *) xmlNodeListGetString (doc, attr->children, 1);
/* Get the disk format (may not be set). */
xpathCtx->node = nodes->nodeTab[i];
xpformat = xmlXPathEvalExpression (BAD_CAST "./driver/@type", xpathCtx);
char *format = NULL;
if (xpformat != NULL &&
xpformat->nodesetval &&
xpformat->nodesetval->nodeNr > 0) {
assert (xpformat->nodesetval->nodeTab[0]);
assert (xpformat->nodesetval->nodeTab[0]->type == XML_ATTRIBUTE_NODE);
attr = (xmlAttrPtr) xpformat->nodesetval->nodeTab[0];
format = (char *) xmlNodeListGetString (doc, attr->children, 1);
}
/* Add the disk, with optional format. */
struct guestfs_add_drive_opts_argv optargs = { .bitmask = 0 };
if (read_only) {
optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK;
optargs.readonly = read_only;
}
if (format) {
optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK;
optargs.format = format;
}
int t = guestfs_add_drive_opts_argv (g, filename, &optargs);
xmlFree (filename);
xmlFree (format);
xmlXPathFreeObject (xpfilename);
xmlXPathFreeObject (xpformat);
if (t == -1)
goto cleanup;
nr_added++;
}
if (nr_added == 0) {
fprintf (stderr, _("guestfish: libvirt domain '%s' has no disks\n"),
guest);
goto cleanup;
}
/* Successful. */
r = nr_added;
cleanup:
free (xml);
if (xpathObj) xmlXPathFreeObject (xpathObj);
if (xpathCtx) xmlXPathFreeContext (xpathCtx);
if (doc) xmlFreeDoc (doc);
if (dom) virDomainFree (dom);
if (conn) virConnectClose (conn);
return r;
}
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