launch: libvirt: Use guestfs_disk_format API to autodetect input format.

1 files changed, 19 insertions, 85 deletions

diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 9f14add6..07b65571 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -94,7 +94,6 @@ xmlBufferDetach (xmlBufferPtr buf)
 #endif
 
 static xmlChar *construct_libvirt_xml (guestfs_h *g, const char *capabilities_xml, const char *kernel, const char *initrd, const char *appliance, const char *guestfsd_sock, const char *console_sock);
-static char *autodetect_format (guestfs_h *g, const char *path);
 static void libvirt_error (guestfs_h *g, const char *fs, ...);
 static int is_blk (const char *path);
 static int random_chars (char *ret, size_t len);
@@ -838,10 +837,28 @@ construct_libvirt_xml_disk (guestfs_h *g, xmlTextWriterPtr xo,
                                            BAD_CAST drv->format));
   }
   else {
-    format = autodetect_format (g, path);
+    /* libvirt has disabled the feature of detecting the disk format,
+     * unless the administrator sets allow_disk_format_probing=1 in
+     * qemu.conf.  There is no way to detect if this option is set, so we
+     * have to do format detection here using qemu-img and pass that to
+     * libvirt.
+     *
+     * This is still a security issue, so in most cases it is recommended
+     * the users pass the format to libguestfs which will faithfully pass
+     * that to libvirt and this function won't be used.
+     */
+    format = guestfs_disk_format (g, path);
     if (!format)
       goto err;
 
+    if (STREQ (format, "unknown")) {
+      error (g, _("could not auto-detect the format of '%s'\n"
+                  "If the format is known, pass the format to libguestfs, eg. using the\n"
+                  "'--format' option, or via the optional 'format' argument to 'add-drive'."),
+             path);
+      goto err;
+    }
+
     XMLERROR (-1,
               xmlTextWriterWriteAttribute (xo, BAD_CAST "type",
                                            BAD_CAST format));
@@ -1070,89 +1087,6 @@ construct_libvirt_xml_qemu_cmdline (guestfs_h *g, xmlTextWriterPtr xo)
   return -1;
 }
 
-/* libvirt has disabled the feature of detecting the disk format,
- * unless the administrator sets allow_disk_format_probing=1 in
- * qemu.conf.  There is no way to detect if this option is set, so we
- * have to do format detection here using qemu-img and pass that to
- * libvirt.
- *
- * This is still a security issue, so in most cases it is recommended
- * the users pass the format to libguestfs which will faithfully pass
- * that to libvirt and this function won't be used.
- */
-static char *
-autodetect_format (guestfs_h *g, const char *path)
-{
-  pid_t pid;
-  int fd[2];
-  FILE *fp;
-  char *line = NULL;
-  size_t len;
-  char *p;
-  size_t n;
-  char *ret = NULL;
-
-  if (pipe2 (fd, O_CLOEXEC) == -1) {
-    perrorf (g, "pipe2");
-    return NULL;
-  }
-
-  pid = fork ();
-  if (pid == -1) {
-    perrorf (g, "fork");
-    close (fd[0]);
-    close (fd[1]);
-    return NULL;
-  }
-
-  if (pid == 0) {               /* child */
-    close (fd[0]);
-    dup2 (fd[1], 1);
-    close (fd[1]);
-
-    execlp ("qemu-img", "qemu-img", "info", path, NULL);
-    perror ("could not execute 'qemu-img info'");
-    _exit (EXIT_FAILURE);
-  }
-
-  close (fd[1]);
-
-  fp = fdopen (fd[0], "r");
-  if (fp == NULL) {
-    perrorf (g, "fdopen: qemu-img info");
-    close (fd[0]);
-    waitpid (pid, NULL, 0);
-    return NULL;
-  }
-
-  while (getline (&line, &len, fp) != -1) {
-    if (STRPREFIX (line, "file format: ")) {
-      p = &line[13];
-      n = strlen (p);
-      if (n > 0 && p[n-1] == '\n')
-        n--;
-      memmove (line, p, n);
-      line[n] = '\0';
-      ret = line;
-      break;
-    }
-  }
-
-  fclose (fp); /* also closes fd[0] */
-  waitpid (pid, NULL, 0);
-
-  if (ret == NULL) {
-    error (g, _("could not auto-detect the format of '%s'\n"
-                "If the format is known, pass the format to libguestfs, eg. using the\n"
-                "'--format=...' option, or via the optional 'format' argument to 'add-drive'."),
-           path);
-    free (line);
-    return NULL;
-  }
-
-  return ret;                   /* caller frees */
-}
-
 static int
 is_blk (const char *path)
 {