Implement device name translation. Remove device name hacks in tests.

[libguestfs.git] / daemon / guestfsd.c

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 1d74054..2e83b9f 100644 (file)
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -32,6 +32,8 @@
 #include <sys/select.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 #include <ctype.h>
 #include <signal.h>
 
@@ -685,3 +687,50 @@ shell_quote (char *out, int len, const char *in)
 
   return outlen;
 }
+
+/* Perform device name translation.  Don't call this directly -
+ * use the IS_DEVICE macro.
+ *
+ * See guestfs(3) for the algorithm.
+ *
+ * We have to open the device and test for ENXIO, because
+ * the device nodes themselves will exist in the appliance.
+ */
+int
+device_name_translation (char *device, const char *func)
+{
+  int fd;
+
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
+
+  if (errno != ENXIO) {
+  error:
+    reply_with_perror ("%s: %s", func, device);
+    return -1;
+  }
+
+  /* If the name begins with "/dev/sd" then try the alternatives. */
+  if (strncmp (device, "/dev/sd", 7) != 0)
+    goto error;
+
+  device[5] = 'h';             /* /dev/hd (old IDE driver) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
+
+  device[5] = 'v';             /* /dev/vd (for virtio devices) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
+
+  device[5] = 's';             /* Restore original device name. */
+  goto error;
+}