file: Fix file command on /dev/VG/LV paths (RHBZ#582484).

[libguestfs.git] / daemon / file.c

diff --git a/daemon/file.c b/daemon/file.c
index 2594207..da899b6 100644 (file)
--- a/daemon/file.c
+++ b/daemon/file.c
@@ -34,6 +34,26 @@ do_touch (const char *path)
 {
   int fd;
   int r;
+  struct stat buf;
+
+  /* RHBZ#582484: Restrict touch to regular files.  It's also OK
+   * here if the file does not exist, since we will create it.
+   */
+  CHROOT_IN;
+  r = lstat (path, &buf);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    if (errno != ENOENT) {
+      reply_with_perror ("lstat: %s", path);
+      return -1;
+    }
+  } else {
+    if (! S_ISREG (buf.st_mode)) {
+      reply_with_error ("%s: touch can only be used on a regular files", path);
+      return -1;
+    }
+  }
 
   CHROOT_IN;
   fd = open (path, O_WRONLY | O_CREAT | O_NOCTTY, 0666);
@@ -524,21 +544,50 @@ do_file (const char *path)
       return NULL;
     }
     path = buf;
+
+    /* For non-dev, check this is a regular file, else just return the
+     * file type as a string (RHBZ#582484).
+     */
+    struct stat statbuf;
+    if (lstat (path, &statbuf) == -1) {
+      reply_with_perror ("lstat: %s", display_path);
+      free (buf);
+      return NULL;
+    }
+
+    if (! S_ISREG (statbuf.st_mode)) {
+      char *ret;
+
+      free (buf);
+
+      if (S_ISDIR (statbuf.st_mode))
+        ret = strdup ("directory");
+      else if (S_ISCHR (statbuf.st_mode))
+        ret = strdup ("character device");
+      else if (S_ISBLK (statbuf.st_mode))
+        ret = strdup ("block device");
+      else if (S_ISFIFO (statbuf.st_mode))
+        ret = strdup ("FIFO");
+      else if (S_ISLNK (statbuf.st_mode))
+        ret = strdup ("symbolic link");
+      else if (S_ISSOCK (statbuf.st_mode))
+        ret = strdup ("socket");
+      else
+        ret = strdup ("unknown, not regular file");
+
+      if (ret == NULL)
+        reply_with_perror ("strdup");
+      return ret;
+    }
   }
 
-  /* file(1) manpage claims "file returns 0 on success, and non-zero on
-   * error", but this is evidently not true.  It always returns 0, in
-   * every scenario I can think up.  So check the target is readable
-   * first.
+  /* Which flags to use?  For /dev paths, follow links because
+   * /dev/VG/LV is a symbolic link.
    */
-  if (access (path, R_OK) == -1) {
-    reply_with_perror ("access: %s", display_path);
-    free (buf);
-    return NULL;
-  }
+  const char *flags = is_dev ? "-zbsL" : "-zb";
 
   char *out, *err;
-  int r = command (&out, &err, "file", "-zbsL", path, NULL);
+  int r = command (&out, &err, "file", flags, path, NULL);
   free (buf);
 
   if (r == -1) {