root/kernel/syscalls/mknod.c

/* */

DEFINITIONS

1. sys_mknod

   1 /*
   2  * fiwix/kernel/syscalls/mknod.c
   3  *
   4  * Copyright 2018, Jordi Sanfeliu. All rights reserved.
   5  * Distributed under the terms of the Fiwix License.
   6  */
   7 
   8 #include <fiwix/types.h>
   9 #include <fiwix/fs.h>
  10 #include <fiwix/stat.h>
  11 #include <fiwix/errno.h>
  12 #include <fiwix/string.h>
  13 
  14 #ifdef __DEBUG__
  15 #include <fiwix/stdio.h>
  16 #include <fiwix/process.h>
  17 #endif /*__DEBUG__ */
  18 
  19 int sys_mknod(const char *pathname, __mode_t mode, __dev_t dev)
  20 {
  21         struct inode *i, *dir;
  22         char *tmp_name, *basename;
  23         int errno;
  24 
  25 #ifdef __DEBUG__
  26         printk("(pid %d) sys_mknod('%s', %d, %x)\n", current->pid, pathname, mode, dev);
  27 #endif /*__DEBUG__ */
  28 
  29         if(!S_ISCHR(mode) && !S_ISBLK(mode) && !S_ISFIFO(mode)) {
  30                 return -EINVAL;
  31         }
  32         if(!S_ISFIFO(mode) && !IS_SUPERUSER) {
  33                 return -EPERM;
  34         }
  35 
  36         if((errno = malloc_name(pathname, &tmp_name)) < 0) {
  37                 return errno;
  38         }
  39         basename = get_basename(tmp_name);
  40         if((errno = namei(tmp_name, &i, &dir, !FOLLOW_LINKS))) {
  41                 if(!dir) {
  42                         free_name(tmp_name);
  43                         return errno;
  44                 }
  45         }
  46         if(!errno) {
  47                 iput(i);
  48                 iput(dir);
  49                 free_name(tmp_name);
  50                 return -EEXIST;
  51         }
  52         if(IS_RDONLY_FS(dir)) {
  53                 iput(dir);
  54                 free_name(tmp_name);
  55                 return -EROFS;
  56         }
  57         if(check_permission(TO_EXEC | TO_WRITE, dir) < 0) {
  58                 iput(dir);
  59                 free_name(tmp_name);
  60                 return -EACCES;
  61         }
  62 
  63         if(dir->fsop && dir->fsop->mknod) {
  64                 errno = dir->fsop->mknod(dir, basename, mode, dev);
  65         } else {
  66                 errno = -EPERM;
  67         }
  68         iput(dir);
  69         free_name(tmp_name);
  70         return errno;
  71 }

/* */