Энциклопедия разработчика модулей ядра Linux

* structure we want to use, and the function we use for

* permissions. It's also possible to specify functions

* to be called for anything else which could be done to

* an inode (although we don't bother, we just put NULL). */

static struct inode_operations Inode_Ops_4_Our_Proc_File = {

 &File_Ops_4_Our_Proc_File,

 NULL, /* create */

 NULL, /* lookup */

 NULL, /* link */

 NULL, /* unlink */

 NULL, /* symlink */

 NULL, /* mkdir */

 NULL, /* rmdir */

 NULL, /* mknod */

 NULL, /* rename */

 NULL, /* readlink */

 NULL, /* follow_link */

 NULL, /* readpage */

 NULL, /* writepage */

 NULL, /* bmap */

 NULL, /* truncate */

 module_permission /* check for permissions */

};

/* Directory entry */

static struct proc_dir_entry Our_Proc_File = {

 0, /* Inode number - ignore, it will be filled by proc_register[_dynamic] */

 7, /* Length of the file name */

 "rw_test", /* The file name */

 S_IFREG | S_IRUGO | S_IWUSR,

 /* File mode - this is a regular file which

 * can be read by its owner, its group, and everybody

 * else. Also, its owner can write to it.

 *

 * Actually, this field is just for reference, it's

 * module_permission that does the actual check. It

 * could use this field, but in our implementation it

 * doesn't, for simplicity. */

 1, /* Number of links (directories where the file is referenced) */

 0, 0, /* The uid and gid for the file - we give it to root */

 80, /* The size of the file reported by ls. */

 &Inode_Ops_4_Our_Proc_File,

 /* A pointer to the inode structure for

 * the file, if we need it. In our case we

 * do, because we need a write function. */

 NULL

 /* The read function for the file. Irrelevant,

 * because we put it in the inode structure above */

};

/* Module initialization and cleanup ******************* */

/* Initialize the module - register the proc file */

int init_module() {

 /* Success if proc_register[_dynamic] is a success, failure otherwise */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)

 /* In version 2.2, proc_register assign a dynamic

 * inode number automatically if it is zero in the

 * structure, so there's no more need for

 * proc_register_dynamic */

 return proc_register(&proc_root, &Our_Proc_File);

 #else

 return proc_register_dynamic(&proc_root, &Our_Proc_File);

#endif

}

/* Cleanup - unregister our file from /proc */

void cleanup_module() {

 proc_unregister(&proc_root, Our_Proc_File.low_ino);

}

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