Changeset 23 for trunk/kernel/syscalls/sys_readdir.c

Timestamp:

Jun 18, 2017, 10:06:41 PM (7 years ago)

Author:

alain

Message:

Introduce syscalls.

File:

• trunk/kernel/syscalls/sys_readdir.c (modified) (2 diffs)

trunk/kernel/syscalls/sys_readdir.c

@@ -1 +1 @@
 /*
- * sys_read.c: read entries from an opened directory
- * 
- * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
- * Copyright (c) 2011,2012 UPMC Sorbonne Universites
+ * sys_readdir.c - Read one entry from an open directory.
  *
- * This file is part of ALMOS-kernel.
+ * Author    Alain Greiner (2016,2017)
  *
- * ALMOS-kernel is free software; you can redistribute it and/or modify it
+ * Copyright (c) UPMC Sorbonne Universites
+ *
+ * This file is part of ALMOS-MKH.
+ *
+ * ALMOS-MKH 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; version 2.0 of the License.
  *
- * ALMOS-kernel is distributed in the hope that it will be useful, but
+ * ALMOS-MKH 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
@@ -17 +18 @@
  *
  * You should have received a copy of the GNU General Public License
- * along with ALMOS-kernel; if not, write to the Free Software Foundation,
+ * along with ALMOS-MKH; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <kernel_config.h>
+#include <hal_types.h>
+#include <hal_uspace.h>
+#include <errno.h>
+#include <thread.h>
+#include <printk.h>
 #include <vfs.h>
-#include <sys-vfs.h>
-#include <task.h>
-#include <thread.h>
+#include <process.h>
+#include <syscalls.h>
 
-/* FIXEME: reading dirent from user without any protection */
+//////////////////////////////////////////
+int sys_readdir ( uint32_t       file_id,
+                  vfs_dirent_t * dirent )
+{
+        error_t        error;
+    paddr_t        paddr;
+        xptr_t         file_xp;    // extended pointer on searched directory file descriptor 
+    vfs_dirent_t   k_dirent;   // kernel copy of dirent
 
-int sys_readdir (uint_t fd, struct vfs_usp_dirent_s *dirent)
-{
-        error_t err;
-        struct ku_obj dir;
-        struct task_s *task;
-        struct thread_s *this;
-        struct vfs_file_s *file;
-  
-        file = NULL;
-        task = current_task;
-        this = current_thread;
+        thread_t     * this     = CURRENT_THREAD;
+        process_t    * process  = this->process;
 
-        if((dirent == NULL)                || 
-           (fd >= CONFIG_TASK_FILE_MAX_NR) || 
-           (task_fd_lookup(task, fd, &file)))
+    // check file_id argument
+        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
         {
-                this->info.errno = EBADFD;
+        printk("\n[ERROR] in %s : illegal file descriptor index\n", __FUNCTION__ );
+        this->errno = EBADFD;
                 return -1;
         }
 
-        KU_OBJ(dir, dirent);
-        if((err = vfs_readdir(file, &dir)))
+    // check dirent structure in user space
+    error = vmm_v2p_translate( false , dirent , &paddr );
+
+    if ( error )
+    {
+        printk("\n[ERROR] in %s : user buffer for dirent unmapped = %x\n",
+               __FUNCTION__ , (intptr_t)dirent );
+                this->errno = EFAULT;
+                return -1;
+    }
+
+    // get extended pointer on remote file descriptor
+    file_xp = process_fd_get_xptr( process , file_id );
+
+    if( file_xp == XPTR_NULL )
+    {
+        printk("\n[ERROR] in %s : undefined file descriptor index = %d\n",
+               __FUNCTION__ , file_id );
+            this->errno = EBADFD;
+        return -1;
+    }
+  
+    // call the relevant VFS function
+        error = vfs_readdir( file_xp , &k_dirent );
+
+        if( error )
         {
-                this->info.errno = (err < 0) ? -err : err; 
+        printk("\n[ERROR] in %s : cannot access directory %d\n",
+               __FUNCTION__ , file_id );
+                this->errno = error;
                 return -1;
         }
    
+    // copy dirent to user space
+    hal_copy_to_uspace( dirent , &k_dirent , sizeof(vfs_dirent_t) );
+
         return 0;
-}
+
+}  // end sys_readdir()