virt-alignment-scan: Add ability to list all domains.

The output looks like this:

 F16x64:/dev/sda1      1048576         1024K   ok
 F16x64:/dev/sda2      2097152         2048K   ok
 F16x64:/dev/sda3    526385152         2048K   ok

If the --uuid option is used, then UUIDs are shown instead of names.

5 files changed, 446 insertions, 25 deletions

diff --git a/align/Makefile.am b/align/Makefile.am
index d1d13255..eccb05c0 100644
--- a/align/Makefile.am
+++ b/align/Makefile.am
@@ -34,7 +34,9 @@ SHARED_SOURCE_FILES = \
 
 virt_alignment_scan_SOURCES = \
 	$(SHARED_SOURCE_FILES) \
-	scan.c
+	domains.c \
+	scan.c \
+	scan.h
 
 virt_alignment_scan_CFLAGS = \
 	-DGUESTFS_WARN_DEPRECATED=1 \
diff --git a/align/domains.c b/align/domains.c
new file mode 100644
index 00000000..4ade3f66
--- /dev/null
+++ b/align/domains.c
@@ -0,0 +1,339 @@
+/* virt-alignment-scan
+ * Copyright (C) 2012 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#ifdef HAVE_LIBVIRT
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+#endif
+
+#include "progname.h"
+
+#define GUESTFS_PRIVATE_FOR_EACH_DISK 1
+
+#include "guestfs.h"
+#include "options.h"
+#include "scan.h"
+
+#if defined(HAVE_LIBVIRT) && defined(HAVE_LIBXML2)
+
+/* The list of domains and disks that we build up in
+ * get_domains_from_libvirt.
+ */
+struct disk {
+  struct disk *next;
+  char *filename;
+  char *format; /* could be NULL */
+};
+
+struct domain {
+  char *name;
+  char *uuid;
+  struct disk *disks;
+  size_t nr_disks;
+};
+
+struct domain *domains = NULL;
+size_t nr_domains;
+
+static int
+compare_domain_names (const void *p1, const void *p2)
+{
+  const struct domain *d1 = p1;
+  const struct domain *d2 = p2;
+
+  return strcmp (d1->name, d2->name);
+}
+
+static void
+free_domain (struct domain *domain)
+{
+  struct disk *disk, *next;
+
+  for (disk = domain->disks; disk; disk = next) {
+    next = disk->next;
+    free (disk->filename);
+    free (disk->format);
+    free (disk);
+  }
+
+  free (domain->name);
+  free (domain->uuid);
+}
+
+static void add_domains_by_id (virConnectPtr conn, int *ids, size_t n);
+static void add_domains_by_name (virConnectPtr conn, char **names, size_t n);
+static void add_domain (virDomainPtr dom);
+static int add_disk (guestfs_h *g, const char *filename, const char *format, int readonly, void *domain_vp);
+static void add_disks_to_handle_reverse (struct disk *disk);
+static void reset_guestfs_handle (void);
+
+void
+get_domains_from_libvirt (int uuid, size_t *worst_alignment_ptr)
+{
+  virErrorPtr err;
+  virConnectPtr conn;
+  int n;
+  size_t i;
+  const char *prefix;
+
+  nr_domains = 0;
+  domains = NULL;
+
+  /* Get the list of all domains. */
+  conn = virConnectOpenReadOnly (libvirt_uri);
+  if (!conn) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not connect to libvirt (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  n = virConnectNumOfDomains (conn);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not get number of running domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  int ids[n];
+  n = virConnectListDomains (conn, ids, n);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not list running domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  add_domains_by_id (conn, ids, n);
+
+  n = virConnectNumOfDefinedDomains (conn);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not get number of inactive domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  char *names[n];
+  n = virConnectListDefinedDomains (conn, names, n);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not list inactive domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  add_domains_by_name (conn, names, n);
+
+  /* You must free these even though the libvirt documentation doesn't
+   * mention it.
+   */
+  for (i = 0; i < (size_t) n; ++i)
+    free (names[i]);
+
+  virConnectClose (conn);
+
+  /* No domains? */
+  if (nr_domains == 0)
+    return;
+
+  /* Sort the domains alphabetically by name for display. */
+  qsort (domains, nr_domains, sizeof (struct domain), compare_domain_names);
+
+  for (i = 0; i < nr_domains; ++i) {
+    add_disks_to_handle_reverse (domains[i].disks);
+
+    if (guestfs_launch (g) == -1)
+      exit (EXIT_FAILURE);
+
+    prefix = !uuid ? domains[i].name : domains[i].uuid;
+
+    /* Perform the scan. */
+    scan (worst_alignment_ptr, prefix);
+
+    if (i < nr_domains - 1)
+      reset_guestfs_handle ();
+  }
+
+  /* Free up domains structure. */
+  for (i = 0; i < nr_domains; ++i)
+    free_domain (&domains[i]);
+  free (domains);
+}
+
+static void
+add_domains_by_id (virConnectPtr conn, int *ids, size_t n)
+{
+  size_t i;
+  virDomainPtr dom;
+
+  for (i = 0; i < n; ++i) {
+    if (ids[i] != 0) {          /* RHBZ#538041 */
+      dom = virDomainLookupByID (conn, ids[i]);
+      if (dom) { /* transient errors are possible here, ignore them */
+        add_domain (dom);
+        virDomainFree (dom);
+      }
+    }
+  }
+}
+
+static void
+add_domains_by_name (virConnectPtr conn, char **names, size_t n)
+{
+  size_t i;
+  virDomainPtr dom;
+
+  for (i = 0; i < n; ++i) {
+    dom = virDomainLookupByName (conn, names[i]);
+    if (dom) { /* transient errors are possible here, ignore them */
+      add_domain (dom);
+      virDomainFree (dom);
+    }
+  }
+}
+
+static void
+add_domain (virDomainPtr dom)
+{
+  struct domain *domain;
+
+  domains = realloc (domains, (nr_domains + 1) * sizeof (struct domain));
+  if (domains == NULL) {
+    perror ("realloc");
+    exit (EXIT_FAILURE);
+  }
+
+  domain = &domains[nr_domains];
+  nr_domains++;
+
+  domain->name = strdup (virDomainGetName (dom));
+  if (domain->name == NULL) {
+    perror ("strdup");
+    exit (EXIT_FAILURE);
+  }
+
+  char uuid[VIR_UUID_STRING_BUFLEN];
+  if (virDomainGetUUIDString (dom, uuid) == 0) {
+    domain->uuid = strdup (uuid);
+    if (domain->uuid == NULL) {
+      perror ("strdup");
+      exit (EXIT_FAILURE);
+    }
+  }
+  else
+    domain->uuid = NULL;
+
+  domain->disks = NULL;
+  int n = guestfs___for_each_disk (g, dom, add_disk, domain);
+  if (n == -1)
+    exit (EXIT_FAILURE);
+  domain->nr_disks = n;
+}
+
+static int
+add_disk (guestfs_h *g,
+          const char *filename, const char *format, int readonly,
+          void *domain_vp)
+{
+  struct domain *domain = domain_vp;
+  struct disk *disk;
+
+  disk = malloc (sizeof *disk);
+  if (disk == NULL) {
+    perror ("malloc");
+    return -1;
+  }
+
+  disk->next = domain->disks;
+  domain->disks = disk;
+
+  disk->filename = strdup (filename);
+  if (disk->filename == NULL) {
+    perror ("malloc");
+    return -1;
+  }
+  if (format) {
+    disk->format = strdup (format);
+    if (disk->format == NULL) {
+      perror ("malloc");
+      return -1;
+    }
+  }
+  else
+    disk->format = NULL;
+
+  return 0;
+}
+
+static void
+add_disks_to_handle_reverse (struct disk *disk)
+{
+  if (disk == NULL)
+    return;
+
+  add_disks_to_handle_reverse (disk->next);
+
+  struct guestfs_add_drive_opts_argv optargs = { .bitmask = 0 };
+
+  optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK;
+  optargs.readonly = 1;
+
+  if (disk->format) {
+    optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK;
+    optargs.format = disk->format;
+  }
+
+  if (guestfs_add_drive_opts_argv (g, disk->filename, &optargs) == -1)
+    exit (EXIT_FAILURE);
+}
+
+/* Close and reopen the libguestfs handle. */
+static void
+reset_guestfs_handle (void)
+{
+  /* Copy the settings from the old handle. */
+  int verbose = guestfs_get_verbose (g);
+  int trace = guestfs_get_trace (g);
+
+  guestfs_close (g);
+
+  g = guestfs_create ();
+  if (g == NULL) {
+    fprintf (stderr, _("guestfs_create: failed to create handle\n"));
+    exit (EXIT_FAILURE);
+  }
+
+  guestfs_set_verbose (g, verbose);
+  guestfs_set_trace (g, trace);
+}
+
+#endif
diff --git a/align/scan.c b/align/scan.c
index 7b4631ab..e1fd0d04 100644
--- a/align/scan.c
+++ b/align/scan.c
@@ -39,6 +39,7 @@
 
 #include "guestfs.h"
 #include "options.h"
+#include "scan.h"
 
 /* These globals are shared with options.c. */
 guestfs_h *g;
@@ -53,8 +54,6 @@ int inspector = 0;
 
 static int quiet = 0;           /* --quiet */
 
-static int scan (void);
-
 static inline char *
 bad_cast (char const *s)
 {
@@ -111,6 +110,7 @@ main (int argc, char *argv[])
     { "format", 2, 0, 0 },
     { "help", 0, 0, HELP_OPTION },
     { "quiet", 0, 0, 'q' },
+    { "uuid", 0, 0, 0, },
     { "verbose", 0, 0, 'v' },
     { "version", 0, 0, 'V' },
     { 0, 0, 0, 0 }
@@ -120,6 +120,9 @@ main (int argc, char *argv[])
   const char *format = NULL;
   int c;
   int option_index;
+  int uuid = 0;
+  /* This just needs to be larger than any alignment we care about. */
+  size_t worst_alignment = UINT_MAX;
   int exit_code;
 
   g = guestfs_create ();
@@ -141,6 +144,8 @@ main (int argc, char *argv[])
           format = NULL;
         else
           format = optarg;
+      } else if (STREQ (long_options[option_index].name, "uuid")) {
+        uuid = 1;
       } else {
         fprintf (stderr, _("%s: unknown long option: %s (%d)\n"),
                  program_name, long_options[option_index].name, option_index);
@@ -197,30 +202,50 @@ main (int argc, char *argv[])
     usage (EXIT_FAILURE);
 
   /* The user didn't specify any drives to scan. */
-  if (drvs == NULL)
-    usage (EXIT_FAILURE);
+  if (drvs == NULL) {
+#if defined(HAVE_LIBVIRT) && defined(HAVE_LIBXML2)
+    get_domains_from_libvirt (uuid, &worst_alignment);
+#else
+    fprintf (stderr, _("%s: compiled without support for libvirt and/or libxml2.\n"),
+             program_name);
+    exit (EXIT_FAILURE);
+#endif
+  } else {
+    if (uuid) {
+      fprintf (stderr, _("%s: --uuid option cannot be used with -a or -d\n"),
+               program_name);
+      exit (EXIT_FAILURE);
+    }
 
-  /* Add domains/drives from the command line (for a single guest). */
-  add_drives (drvs, 'a');
+    /* Add domains/drives from the command line (for a single guest). */
+    add_drives (drvs, 'a');
 
-  if (guestfs_launch (g) == -1)
-    exit (EXIT_FAILURE);
+    if (guestfs_launch (g) == -1)
+      exit (EXIT_FAILURE);
+
+    /* Free up data structures, no longer needed after this point. */
+    free_drives (drvs);
 
-  /* Free up data structures, no longer needed after this point. */
-  free_drives (drvs);
+    /* Perform the scan. */
+    scan (&worst_alignment, NULL);
 
-  /* Perform the scan. */
-  exit_code = scan ();
+    guestfs_close (g);
+  }
 
-  guestfs_close (g);
+  /* Decide on an appropriate exit code. */
+  if (worst_alignment < 4096)
+    exit_code = 3;
+  else if (worst_alignment < 65536)
+    exit_code = 2;
+  else
+    exit_code = 0;
 
   exit (exit_code);
 }
 
-static int
-scan (void)
+void
+scan (size_t *worst_alignment, const char *prefix)
 {
-  int exit_code = 0;
   char **devices;
   size_t i, j;
   size_t alignment;
@@ -247,9 +272,13 @@ scan (void)
       /* Start offset of the partition in bytes. */
       start = parts->val[j].part_start;
 
-      if (!quiet)
+      if (!quiet) {
+        if (prefix)
+          printf ("%s:", prefix);
+
         printf ("%s%d %12" PRIu64 " ",
                 devices[i], (int) parts->val[j].part_num, start);
+      }
 
       /* What's the alignment? */
       if (start == 0)           /* Probably not possible, but anyway. */
@@ -267,13 +296,13 @@ scan (void)
           printf ("- ");
       }
 
+      if (alignment < *worst_alignment)
+        *worst_alignment = alignment;
+
       if (alignment < 12) {     /* Bad in general: < 4K alignment */
-        exit_code = 3;
         if (!quiet)
           printf ("bad (%s)\n", _("alignment < 4K"));
       } else if (alignment < 16) { /* Bad on NetApps: < 64K alignment */
-        if (exit_code < 2)
-          exit_code = 2;
         if (!quiet)
           printf ("bad (%s)\n", _("alignment < 64K"));
       } else {
@@ -286,6 +315,4 @@ scan (void)
     free (devices[i]);
   }
   free (devices);
-
-  return exit_code;
 }
diff --git a/align/scan.h b/align/scan.h
new file mode 100644
index 00000000..1678d8d2
--- /dev/null
+++ b/align/scan.h
@@ -0,0 +1,30 @@
+/* virt-alignment-scan
+ * Copyright (C) 2012 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef GUESTFS_VIRT_ALIGNMENT_SCAN_H_
+#define GUESTFS_VIRT_ALIGNMENT_SCAN_H_
+
+/* domains.c */
+#if defined(HAVE_LIBVIRT) && defined(HAVE_LIBXML2)
+extern void get_domains_from_libvirt (int uuid, size_t *worst_alignment);
+#endif
+
+/* scan.c */
+extern void scan (size_t *worst_alignment, const char *prefix);
+
+#endif /* GUESTFS_VIRT_ALIGNMENT_SCAN_H_ */
diff --git a/align/virt-alignment-scan.pod b/align/virt-alignment-scan.pod
index 56c51abd..3be721b0 100755
--- a/align/virt-alignment-scan.pod
+++ b/align/virt-alignment-scan.pod
@@ -10,6 +10,8 @@ virt-alignment-scan - Check alignment of virtual machine partitions
 
  virt-alignment-scan [--options] -a disk.img [-a disk.img ...]
 
+ virt-alignment-scan [--options]
+
 =head1 DESCRIPTION
 
 When older operating systems install themselves, the partitioning
@@ -51,6 +53,14 @@ possibly the I<-c> option:
  /dev/sda2    105906176         1024K   ok
  /dev/sdb1        65536           64K   ok
 
+Run virt-alignment-scan without any I<-a> or I<-d> options to scan all
+libvirt domains.
+
+ # virt-alignment-scan
+ F16x64:/dev/sda1      1048576         1024K   ok
+ F16x64:/dev/sda2      2097152         2048K   ok
+ F16x64:/dev/sda3    526385152         2048K   ok
+
 The output consists of 4 or more whitespace-separated columns.  Only
 the first 4 columns are significant if you want to parse this from a
 program.  The columns are:
@@ -59,8 +69,12 @@ program.  The columns are:
 
 =item col 1
 
-the device and partition name (eg. C</dev/sda1> meaning the
-first partition on the first block device)
+The device and partition name (eg. C</dev/sda1> meaning the
+first partition on the first block device).
+
+When listing all libvirt domains (no I<-a> or I<-d> option given) this
+column is prefixed by the libvirt name or UUID (if I<--uuid> is
+given).  eg: C<WinXP:/dev/sda1>
 
 =item col 2
 
@@ -151,6 +165,15 @@ security problem with malicious guests (CVE-2010-3851).
 Don't produce any output.  Just set the exit code
 (see L</EXIT STATUS> below).
 
+=item B<--uuid>
+
+Print UUIDs instead of names.  This is useful for following a guest
+even when the guest is migrated or renamed, or when two guests happen
+to have the same name.
+
+This option only applies when listing all libvirt domains (when no
+I<-a> or I<-d> options are specified).
+
 =item B<-v>
 
 =item B<--verbose>