source: trunk/kernel/syscalls/sys_chmod.c @ 23

Last change on this file since 23 was 23, checked in by alain, 7 years ago

Introduce syscalls.

File size: 2.8 KB
Line 
1/*
2 * sys_chmod.c - Change file access rights.
3 *
4 * Author    Alain Greiner  (2016,2017)
5 *
6 * Copyright (c) 2015 UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <hal_types.h>
25#include <hal_uspace.h>
26#include <vfs.h>
27#include <vmm.h>
28#include <printk.h>
29#include <thread.h>
30#include <process.h>
31
32//////////////////////////////////
33int sys_chmod( char    * pathname,
34               uint32_t  rights )
35{
36    error_t     error;
37    paddr_t     paddr;
38    uint32_t    length;
39    char        kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
40       
41        thread_t  * this    = CURRENT_THREAD;
42        process_t * process = this->process;
43
44    // check pathname in user space
45    error = vmm_v2p_translate( false , pathname , &paddr );
46
47        if( error )
48        {
49        printk("\n[ERROR] in %s : user pathname unmapped for thread %x in process %x\n",
50               __FUNCTION__ , this->trdid , process->pid );
51                this->errno = EINVAL;
52                return -1;
53        }       
54
55    // get pathname length
56    length = hal_strlen_from_uspace( pathname );
57
58    if( length >= CONFIG_VFS_MAX_PATH_LENGTH )
59    {
60        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
61                this->errno = ENFILE;
62        return -1;
63    }
64 
65        // get pathname copy in kernel space
66    hal_copy_from_uspace( kbuf, pathname, length );
67
68    // get cluster and local pointer on reference process
69    xptr_t      ref_xp  = process->ref_xp;
70    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
71    cxy_t       ref_cxy = GET_CXY( ref_xp );
72
73    // get extended pointer on cwd inode
74    xptr_t cwd_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
75   
76    // get the cwd lock in read mode from reference process
77        remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
78
79    // call the relevant VFS function
80        error = vfs_chmod( cwd_xp,
81                       kbuf,
82                       rights );
83
84    // release the cwd lock
85        remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
86
87    if( error )
88        {
89        printk("\n[ERROR] in %s : cannot remove directory %s\n",
90               __FUNCTION__ , kbuf );
91                this->errno = error;
92                return -1;
93        }
94   
95        return 0;
96
97}  // end sys_chmod()   
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