X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Finspect.c;h=dbb194b969cfa426dca7e69f6f9016e2cae12948;hp=d1bb7bb42802d88daf6f6d53d1c83e277e1223f5;hb=b4618fb060b40ba70f2be28b1b1ad625722a7edf;hpb=8289aa1ad68ec94c87fc4d538f638d8816052d92

diff --git a/src/inspect.c b/src/inspect.c
index d1bb7bb..dbb194b 100644
--- a/src/inspect.c
+++ b/src/inspect.c
@@ -31,6 +31,7 @@
 #include <hivex.h>
 #include <augeas.h>
 
+#include "c-ctype.h"
 #include "ignore-value.h"
 #include "xstrtol.h"
 
@@ -51,12 +52,14 @@ static pcre *re_fedora;
 static pcre *re_rhel_old;
 static pcre *re_rhel;
 static pcre *re_rhel_no_minor;
-static pcre *re_debian;
+static pcre *re_major_minor;
 static pcre *re_aug_seq;
 static pcre *re_xdev;
 static pcre *re_windows_version;
 
 static void compile_regexps (void) __attribute__((constructor));
+static void free_regexps (void) __attribute__((destructor));
+
 static void
 compile_regexps (void)
 {
@@ -82,12 +85,28 @@ compile_regexps (void)
            "(?:Red Hat Enterprise Linux|CentOS|Scientific Linux).*release (\\d+)\\.(\\d+)", 0);
   COMPILE (re_rhel_no_minor,
            "(?:Red Hat Enterprise Linux|CentOS|Scientific Linux).*release (\\d+)", 0);
-  COMPILE (re_debian, "(\\d+)\\.(\\d+)", 0);
+  COMPILE (re_major_minor, "(\\d+)\\.(\\d+)", 0);
   COMPILE (re_aug_seq, "/\\d+$", 0);
   COMPILE (re_xdev, "^/dev/(?:h|s|v|xv)d([a-z]\\d*)$", 0);
   COMPILE (re_windows_version, "^(\\d+)\\.(\\d+)", 0);
 }
 
+static void
+free_regexps (void)
+{
+  pcre_free (re_file_elf);
+  pcre_free (re_file_win64);
+  pcre_free (re_elf_ppc64);
+  pcre_free (re_fedora);
+  pcre_free (re_rhel_old);
+  pcre_free (re_rhel);
+  pcre_free (re_rhel_no_minor);
+  pcre_free (re_major_minor);
+  pcre_free (re_aug_seq);
+  pcre_free (re_xdev);
+  pcre_free (re_windows_version);
+}
+
 /* Match a regular expression which contains no captures.  Returns
  * true if it matches or false if it doesn't.
  */
@@ -209,6 +228,15 @@ is_regular_file (const char *filename)
 static char *
 cpio_arch (guestfs_h *g, const char *file, const char *path)
 {
+  TMP_TEMPLATE_ON_STACK (dir);
+#define dir_len (strlen (dir))
+#define initrd_len (dir_len + 16)
+  char initrd[initrd_len];
+#define cmd_len (dir_len + 256)
+  char cmd[cmd_len];
+#define bin_len (dir_len + 32)
+  char bin[bin_len];
+
   char *ret = NULL;
 
   const char *method;
@@ -219,20 +247,16 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
   else
     method = "cat";
 
-  char dir[] = "/tmp/initrd.XXXXXX";
-#define dir_len (sizeof dir)
   if (mkdtemp (dir) == NULL) {
     perrorf (g, "mkdtemp");
     goto out;
   }
 
-  char dir_initrd[dir_len + 16];
-  snprintf (dir_initrd, dir_len + 16, "%s/initrd", dir);
-  if (guestfs_download (g, path, dir_initrd) == -1)
+  snprintf (initrd, initrd_len, "%s/initrd", dir);
+  if (guestfs_download (g, path, initrd) == -1)
     goto out;
 
-  char cmd[dir_len + 256];
-  snprintf (cmd, dir_len + 256,
+  snprintf (cmd, cmd_len,
             "cd %s && %s initrd | cpio --quiet -id " INITRD_BINARIES1,
             dir, method);
   int r = system (cmd);
@@ -241,11 +265,10 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
     goto out;
   }
 
-  char bin[dir_len + 32];
   const char *bins[] = INITRD_BINARIES2;
   size_t i;
   for (i = 0; i < sizeof bins / sizeof bins[0]; ++i) {
-    snprintf (bin, dir_len + 32, "%s/%s", dir, bins[i]);
+    snprintf (bin, bin_len, "%s/%s", dir, bins[i]);
 
     if (is_regular_file (bin)) {
       int flags = g->verbose ? MAGIC_DEBUG : 0;
@@ -287,11 +310,14 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
    * contain shell meta-characters because of the way it was
    * constructed above.
    */
-  snprintf (cmd, dir_len + 256, "rm -rf %s", dir);
+  snprintf (cmd, cmd_len, "rm -rf %s", dir);
   ignore_value (system (cmd));
 
   return ret;
 #undef dir_len
+#undef initrd_len
+#undef cmd_len
+#undef bin_len
 }
 
 char *
@@ -430,6 +456,7 @@ guestfs___free_inspect_info (guestfs_h *g)
     free (g->fses[i].device);
     free (g->fses[i].product_name);
     free (g->fses[i].arch);
+    free (g->fses[i].windows_systemroot);
     size_t j;
     for (j = 0; j < g->fses[i].nr_fstab; ++j) {
       free (g->fses[i].fstab[j].device);
@@ -476,10 +503,8 @@ static int check_filesystem (guestfs_h *g, const char *device);
 static int check_linux_root (guestfs_h *g, struct inspect_fs *fs);
 static int check_fstab (guestfs_h *g, struct inspect_fs *fs);
 static int check_windows_root (guestfs_h *g, struct inspect_fs *fs);
-static int check_windows_arch (guestfs_h *g, struct inspect_fs *fs,
-                               const char *systemroot);
-static int check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
-                                   const char *systemroot);
+static int check_windows_arch (guestfs_h *g, struct inspect_fs *fs);
+static int check_windows_registry (guestfs_h *g, struct inspect_fs *fs);
 static char *resolve_windows_path_silently (guestfs_h *g, const char *);
 static int extend_fses (guestfs_h *g);
 static int parse_unsigned_int (guestfs_h *g, const char *str);
@@ -597,6 +622,50 @@ check_filesystem (guestfs_h *g, const char *device)
   return 0;
 }
 
+/* Set fs->product_name to the first line of the release file. */
+static int
+parse_release_file (guestfs_h *g, struct inspect_fs *fs,
+                    const char *release_filename)
+{
+  char **product_name = guestfs_head_n (g, 1, release_filename);
+  if (product_name == NULL)
+    return -1;
+  if (product_name[0] == NULL) {
+    error (g, "%s: file is empty", release_filename);
+    free_string_list (product_name);
+    return -1;
+  }
+
+  /* Note that this string becomes owned by the handle and will
+   * be freed by guestfs___free_inspect_info.
+   */
+  fs->product_name = product_name[0];
+  free (product_name);
+
+  return 0;
+}
+
+/* Parse generic MAJOR.MINOR from the fs->product_name string. */
+static int
+parse_major_minor (guestfs_h *g, struct inspect_fs *fs)
+{
+  char *major, *minor;
+
+  if (match2 (g, fs->product_name, re_major_minor, &major, &minor)) {
+    fs->major_version = parse_unsigned_int (g, major);
+    free (major);
+    if (fs->major_version == -1) {
+      free (minor);
+      return -1;
+    }
+    fs->minor_version = parse_unsigned_int (g, minor);
+    free (minor);
+    if (fs->minor_version == -1)
+      return -1;
+  }
+  return 0;
+}
+
 /* The currently mounted device is known to be a Linux root.  Try to
  * determine from this the distro, version, etc.  Also parse
  * /etc/fstab to determine the arrangement of mountpoints and
@@ -610,20 +679,8 @@ check_linux_root (guestfs_h *g, struct inspect_fs *fs)
   if (guestfs_exists (g, "/etc/redhat-release") > 0) {
     fs->distro = OS_DISTRO_REDHAT_BASED; /* Something generic Red Hat-like. */
 
-    char **product_name = guestfs_head_n (g, 1, "/etc/redhat-release");
-    if (product_name == NULL)
-      return -1;
-    if (product_name[0] == NULL) {
-      error (g, "/etc/redhat-release file is empty");
-      free_string_list (product_name);
+    if (parse_release_file (g, fs, "/etc/redhat-release") == -1)
       return -1;
-    }
-
-    /* Note that this string becomes owned by the handle and will
-     * be freed by guestfs___free_inspect_info.
-     */
-    fs->product_name = product_name[0];
-    free (product_name);
 
     char *major, *minor;
     if ((major = match1 (g, fs->product_name, re_fedora)) != NULL) {
@@ -659,34 +716,27 @@ check_linux_root (guestfs_h *g, struct inspect_fs *fs)
   else if (guestfs_exists (g, "/etc/debian_version") > 0) {
     fs->distro = OS_DISTRO_DEBIAN;
 
-    char **product_name = guestfs_head_n (g, 1, "/etc/debian_version");
-    if (product_name == NULL)
+    if (parse_release_file (g, fs, "/etc/debian_version") == -1)
       return -1;
-    if (product_name[0] == NULL) {
-      error (g, "/etc/debian_version file is empty");
-      free_string_list (product_name);
+
+    if (parse_major_minor (g, fs) == -1)
       return -1;
-    }
+  }
+  else if (guestfs_exists (g, "/etc/pardus-release") > 0) {
+    fs->distro = OS_DISTRO_PARDUS;
 
-    /* Note that this string becomes owned by the handle and will
-     * be freed by guestfs___free_inspect_info.
-     */
-    fs->product_name = product_name[0];
-    free (product_name);
+    if (parse_release_file (g, fs, "/etc/pardus-release") == -1)
+      return -1;
 
-    char *major, *minor;
-    if (match2 (g, fs->product_name, re_debian, &major, &minor)) {
-      fs->major_version = parse_unsigned_int (g, major);
-      free (major);
-      if (fs->major_version == -1) {
-        free (minor);
-        return -1;
-      }
-      fs->minor_version = parse_unsigned_int (g, minor);
-      free (minor);
-      if (fs->minor_version == -1)
-        return -1;
-    }
+    if (parse_major_minor (g, fs) == -1)
+      return -1;
+  }
+  else if (guestfs_exists (g, "/etc/arch-release") > 0) {
+    fs->distro = OS_DISTRO_ARCHLINUX;
+
+    /* /etc/arch-release file is empty and I can't see a way to
+     * determine the actual release or product string.
+     */
   }
 
   /* Determine the architecture. */
@@ -806,17 +856,24 @@ add_fstab_entry (guestfs_h *g, struct inspect_fs *fs,
       STREQ (mp, "/sys"))
     return 0;
 
+  /* Ignore /dev/fd (floppy disks) (RHBZ#642929) and CD-ROM drives. */
+  if ((STRPREFIX (spec, "/dev/fd") && c_isdigit (spec[7])) ||
+      STREQ (spec, "/dev/floppy") ||
+      STREQ (spec, "/dev/cdrom"))
+    return 0;
+
   /* Resolve UUID= and LABEL= to the actual device. */
   char *device = NULL;
   if (STRPREFIX (spec, "UUID="))
     device = guestfs_findfs_uuid (g, &spec[5]);
   else if (STRPREFIX (spec, "LABEL="))
     device = guestfs_findfs_label (g, &spec[6]);
-  /* Resolve guest block device names. */
-  else if (spec[0] == '/')
+  /* Ignore "/.swap" (Pardus) and pseudo-devices like "tmpfs". */
+  else if (STRPREFIX (spec, "/dev/"))
+    /* Resolve guest block device names. */
     device = resolve_fstab_device (g, spec);
-  /* Also ignore pseudo-devices completely, like spec == "tmpfs".
-   * If we haven't resolved the device successfully by this point,
+
+  /* If we haven't resolved the device successfully by this point,
    * we don't care, just ignore it.
    */
   if (device == NULL)
@@ -853,39 +910,54 @@ add_fstab_entry (guestfs_h *g, struct inspect_fs *fs,
 }
 
 /* Resolve block device name to the libguestfs device name, eg.
- * /dev/xvdb1 => /dev/vdb1.  This assumes that disks were added in the
- * same order as they appear to the real VM, which is a reasonable
- * assumption to make.  Return things like LV names unchanged (or
- * anything we don't recognize).
+ * /dev/xvdb1 => /dev/vdb1; and /dev/mapper/VG-LV => /dev/VG/LV.  This
+ * assumes that disks were added in the same order as they appear to
+ * the real VM, which is a reasonable assumption to make.  Return
+ * anything we don't recognize unchanged.
  */
 static char *
 resolve_fstab_device (guestfs_h *g, const char *spec)
 {
-  char **devices = guestfs_list_devices (g);
-  if (devices == NULL)
-    return NULL;
+  char *a1;
+  char *device = NULL;
 
-  size_t count;
-  for (count = 0; devices[count] != NULL; count++)
-    ;
+  if (STRPREFIX (spec, "/dev/mapper/")) {
+    /* LVM2 does some strange munging on /dev/mapper paths for VGs and
+     * LVs which contain '-' character:
+     *
+     * ><fs> lvcreate LV--test VG--test 32
+     * ><fs> debug ls /dev/mapper
+     * VG----test-LV----test
+     *
+     * This makes it impossible to reverse those paths directly, so
+     * we have implemented lvm_canonical_lv_name in the daemon.
+     */
+    device = guestfs_lvm_canonical_lv_name (g, spec);
+  }
+  else if ((a1 = match1 (g, spec, re_xdev)) != NULL) {
+    char **devices = guestfs_list_devices (g);
+    if (devices == NULL)
+      return NULL;
+
+    size_t count;
+    for (count = 0; devices[count] != NULL; count++)
+      ;
 
-  char *device = NULL;
-  char *a1 = match1 (g, spec, re_xdev);
-  if (a1) {
     size_t i = a1[0] - 'a'; /* a1[0] is always [a-z] because of regex. */
     if (i < count) {
       size_t len = strlen (devices[i]) + strlen (a1) + 16;
       device = safe_malloc (g, len);
       snprintf (device, len, "%s%s", devices[i], &a1[1]);
     }
-  } else {
+
+    free (a1);
+    free_string_list (devices);
+  }
+  else {
     /* Didn't match device pattern, return original spec unchanged. */
     device = safe_strdup (g, spec);
   }
 
-  free (a1);
-  free_string_list (devices);
-
   return device;
 }
 
@@ -915,34 +987,27 @@ check_windows_root (guestfs_h *g, struct inspect_fs *fs)
     return -1;
   }
 
-  /* XXX There is a case for exposing systemroot and many variables
-   * from the registry through the libguestfs API.
-   */
-
   if (g->verbose)
     fprintf (stderr, "windows %%SYSTEMROOT%% = %s", systemroot);
 
-  if (check_windows_arch (g, fs, systemroot) == -1) {
-    free (systemroot);
+  /* Freed by guestfs___free_inspect_info. */
+  fs->windows_systemroot = systemroot;
+
+  if (check_windows_arch (g, fs) == -1)
     return -1;
-  }
 
-  if (check_windows_registry (g, fs, systemroot) == -1) {
-    free (systemroot);
+  if (check_windows_registry (g, fs) == -1)
     return -1;
-  }
 
-  free (systemroot);
   return 0;
 }
 
 static int
-check_windows_arch (guestfs_h *g, struct inspect_fs *fs,
-                    const char *systemroot)
+check_windows_arch (guestfs_h *g, struct inspect_fs *fs)
 {
-  size_t len = strlen (systemroot) + 32;
+  size_t len = strlen (fs->windows_systemroot) + 32;
   char cmd_exe[len];
-  snprintf (cmd_exe, len, "%s/system32/cmd.exe", systemroot);
+  snprintf (cmd_exe, len, "%s/system32/cmd.exe", fs->windows_systemroot);
 
   char *cmd_exe_path = resolve_windows_path_silently (g, cmd_exe);
   if (!cmd_exe_path)
@@ -962,12 +1027,19 @@ check_windows_arch (guestfs_h *g, struct inspect_fs *fs,
  * registry fields available to callers.
  */
 static int
-check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
-                        const char *systemroot)
+check_windows_registry (guestfs_h *g, struct inspect_fs *fs)
 {
-  size_t len = strlen (systemroot) + 64;
+  TMP_TEMPLATE_ON_STACK (dir);
+#define dir_len (strlen (dir))
+#define software_hive_len (dir_len + 16)
+  char software_hive[software_hive_len];
+#define cmd_len (dir_len + 16)
+  char cmd[cmd_len];
+
+  size_t len = strlen (fs->windows_systemroot) + 64;
   char software[len];
-  snprintf (software, len, "%s/system32/config/software", systemroot);
+  snprintf (software, len, "%s/system32/config/software",
+            fs->windows_systemroot);
 
   char *software_path = resolve_windows_path_silently (g, software);
   if (!software_path)
@@ -980,15 +1052,12 @@ check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
   hive_h *h = NULL;
   hive_value_h *values = NULL;
 
-  char dir[] = "/tmp/winreg.XXXXXX";
-#define dir_len 18
   if (mkdtemp (dir) == NULL) {
     perrorf (g, "mkdtemp");
     goto out;
   }
 
-  char software_hive[dir_len + 16];
-  snprintf (software_hive, dir_len + 16, "%s/software", dir);
+  snprintf (software_hive, software_hive_len, "%s/software", dir);
 
   if (guestfs_download (g, software_path, software_hive) == -1)
     goto out;
@@ -1074,10 +1143,11 @@ check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
    * contain shell meta-characters because of the way it was
    * constructed above.
    */
-  char cmd[dir_len + 16];
-  snprintf (cmd, dir_len + 16, "rm -rf %s", dir);
+  snprintf (cmd, cmd_len, "rm -rf %s", dir);
   ignore_value (system (cmd));
 #undef dir_len
+#undef software_hive_len
+#undef cmd_len
 
   return ret;
 }
@@ -1182,8 +1252,10 @@ guestfs__inspect_get_distro (guestfs_h *g, const char *root)
 
   char *ret;
   switch (fs->distro) {
+  case OS_DISTRO_ARCHLINUX: ret = safe_strdup (g, "archlinux"); break;
   case OS_DISTRO_DEBIAN: ret = safe_strdup (g, "debian"); break;
   case OS_DISTRO_FEDORA: ret = safe_strdup (g, "fedora"); break;
+  case OS_DISTRO_PARDUS: ret = safe_strdup (g, "pardus"); break;
   case OS_DISTRO_REDHAT_BASED: ret = safe_strdup (g, "redhat-based"); break;
   case OS_DISTRO_RHEL: ret = safe_strdup (g, "rhel"); break;
   case OS_DISTRO_WINDOWS: ret = safe_strdup (g, "windows"); break;
@@ -1193,7 +1265,7 @@ guestfs__inspect_get_distro (guestfs_h *g, const char *root)
   return ret;
 }
 
-int 
+int
 guestfs__inspect_get_major_version (guestfs_h *g, const char *root)
 {
   struct inspect_fs *fs = search_for_root (g, root);
@@ -1203,7 +1275,7 @@ guestfs__inspect_get_major_version (guestfs_h *g, const char *root)
   return fs->major_version;
 }
 
-int 
+int
 guestfs__inspect_get_minor_version (guestfs_h *g, const char *root)
 {
   struct inspect_fs *fs = search_for_root (g, root);
@@ -1223,6 +1295,21 @@ guestfs__inspect_get_product_name (guestfs_h *g, const char *root)
   return safe_strdup (g, fs->product_name ? : "unknown");
 }
 
+char *
+guestfs__inspect_get_windows_systemroot (guestfs_h *g, const char *root)
+{
+  struct inspect_fs *fs = search_for_root (g, root);
+  if (!fs)
+    return NULL;
+
+  if (!fs->windows_systemroot) {
+    error (g, _("not a Windows guest, or systemroot could not be determined"));
+    return NULL;
+  }
+
+  return safe_strdup (g, fs->windows_systemroot);
+}
+
 char **
 guestfs__inspect_get_mountpoints (guestfs_h *g, const char *root)
 {
@@ -1295,3 +1382,140 @@ guestfs__inspect_get_filesystems (guestfs_h *g, const char *root)
 
   return ret;
 }
+
+/* List filesystems.
+ *
+ * The current implementation just uses guestfs_vfs_type and doesn't
+ * try mounting anything, but we reserve the right in future to try
+ * mounting filesystems.
+ */
+
+static void remove_from_list (char **list, const char *item);
+static void check_with_vfs_type (guestfs_h *g, const char *dev, char ***ret, size_t *ret_size);
+
+char **
+guestfs__list_filesystems (guestfs_h *g)
+{
+  size_t i;
+  char **ret;
+  size_t ret_size;
+
+  ret = safe_malloc (g, sizeof (char *));
+  ret[0] = NULL;
+  ret_size = 0;
+
+  /* Look to see if any devices directly contain filesystems
+   * (RHBZ#590167).  However vfs-type will fail to tell us anything
+   * useful about devices which just contain partitions, so we also
+   * get the list of partitions and exclude the corresponding devices
+   * by using part-to-dev.
+   */
+  char **devices;
+  devices = guestfs_list_devices (g);
+  if (devices == NULL) {
+    free_string_list (ret);
+    return NULL;
+  }
+  char **partitions;
+  partitions = guestfs_list_partitions (g);
+  if (partitions == NULL) {
+    free_string_list (devices);
+    free_string_list (ret);
+    return NULL;
+  }
+
+  for (i = 0; partitions[i] != NULL; ++i) {
+    char *dev = guestfs_part_to_dev (g, partitions[i]);
+    if (dev)
+      remove_from_list (devices, dev);
+    free (dev);
+  }
+
+  /* Use vfs-type to check for filesystems on devices. */
+  for (i = 0; devices[i] != NULL; ++i)
+    check_with_vfs_type (g, devices[i], &ret, &ret_size);
+  free_string_list (devices);
+
+  /* Use vfs-type to check for filesystems on partitions. */
+  for (i = 0; partitions[i] != NULL; ++i)
+    check_with_vfs_type (g, partitions[i], &ret, &ret_size);
+  free_string_list (partitions);
+
+  if (feature_available (g, "lvm2")) {
+    /* Use vfs-type to check for filesystems on LVs. */
+    char **lvs;
+    lvs = guestfs_lvs (g);
+    if (lvs == NULL) {
+      free_string_list (ret);
+      return NULL;
+    }
+
+    for (i = 0; lvs[i] != NULL; ++i)
+      check_with_vfs_type (g, lvs[i], &ret, &ret_size);
+    free_string_list (lvs);
+  }
+
+  return ret;
+}
+
+/* If 'item' occurs in 'list', remove and free it. */
+static void
+remove_from_list (char **list, const char *item)
+{
+  size_t i;
+
+  for (i = 0; list[i] != NULL; ++i)
+    if (STREQ (list[i], item)) {
+      free (list[i]);
+      for (; list[i+1] != NULL; ++i)
+        list[i] = list[i+1];
+      list[i] = NULL;
+      return;
+    }
+}
+
+/* Use vfs-type to look for a filesystem of some sort on 'dev'.
+ * Apart from some types which we ignore, add the result to the
+ * 'ret' string list.
+ */
+static void
+check_with_vfs_type (guestfs_h *g, const char *device,
+                     char ***ret, size_t *ret_size)
+{
+  char *v;
+
+  guestfs_error_handler_cb old_error_cb = g->error_cb;
+  g->error_cb = NULL;
+  char *vfs_type = guestfs_vfs_type (g, device);
+  g->error_cb = old_error_cb;
+
+  if (!vfs_type)
+    v = safe_strdup (g, "unknown");
+  else {
+    /* Ignore all "*_member" strings.  In libblkid these are returned
+     * for things which are members of some RAID or LVM set, most
+     * importantly "LVM2_member" which is a PV.
+     */
+    size_t n = strlen (vfs_type);
+    if (n >= 7 && STREQ (&vfs_type[n-7], "_member")) {
+      free (vfs_type);
+      return;
+    }
+
+    /* Ignore LUKS-encrypted partitions.  These are also containers. */
+    if (STREQ (vfs_type, "crypto_LUKS")) {
+      free (vfs_type);
+      return;
+    }
+
+    v = vfs_type;
+  }
+
+  /* Extend the return array. */
+  size_t i = *ret_size;
+  *ret_size += 2;
+  *ret = safe_realloc (g, *ret, (*ret_size + 1) * sizeof (char *));
+  (*ret)[i] = safe_strdup (g, device);
+  (*ret)[i+1] = v;
+  (*ret)[i+2] = NULL;
+}