fish: Add -c/--connect and -d/--domain options.

[libguestfs.git] / fish / virt.c

diff --git a/fish/virt.c b/fish/virt.c
new file mode 100644 (file)
index 0000000..9c4ce1a
--- /dev/null
+++ b/fish/virt.c
@@ -0,0 +1,191 @@
+/* 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"
+
+static int add_drives_from_node_set (xmlDocPtr doc, xmlNodeSetPtr nodes);
+
+/* 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;
+  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;
+  }
+
+  xpathObj = xmlXPathEvalExpression (BAD_CAST "//devices/disk/source/@dev",
+                                     xpathCtx);
+  if (xpathObj == NULL) {
+    fprintf (stderr, _("guestfish: unable to evaluate XPath expression\n"));
+    goto cleanup;
+  }
+
+  nr_added += add_drives_from_node_set (doc, xpathObj->nodesetval);
+
+  xmlXPathFreeObject (xpathObj); xpathObj = NULL;
+
+  xpathObj = xmlXPathEvalExpression (BAD_CAST "//devices/disk/source/@file",
+                                     xpathCtx);
+  if (xpathObj == NULL) {
+    fprintf (stderr, _("guestfish: unable to evaluate XPath expression\n"));
+    goto cleanup;
+  }
+
+  nr_added += add_drives_from_node_set (doc, xpathObj->nodesetval);
+
+  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;
+}
+
+static int
+add_drives_from_node_set (xmlDocPtr doc, xmlNodeSetPtr nodes)
+{
+  if (!nodes)
+    return 0;
+
+  int i;
+
+  for (i = 0; i < nodes->nodeNr; ++i) {
+    assert (nodes->nodeTab[i]);
+    assert (nodes->nodeTab[i]->type == XML_ATTRIBUTE_NODE);
+    xmlAttrPtr attr = (xmlAttrPtr) nodes->nodeTab[i];
+
+    char *device = (char *) xmlNodeListGetString (doc, attr->children, 1);
+
+    int r;
+    if (!read_only)
+      r = guestfs_add_drive (g, device);
+    else
+      r = guestfs_add_drive_ro (g, device);
+    if (r == -1)
+      exit (EXIT_FAILURE);
+
+    xmlFree (device);
+  }
+
+  return nodes->nodeNr;
+}