mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
b87a267eb7
Add a .show_options super operation to devpts. Small cleanup: when parsing the "mode" option, mask with S_IALLUGO instead of ~S_IFMT. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
260 lines
5.7 KiB
C
260 lines
5.7 KiB
C
/* -*- linux-c -*- --------------------------------------------------------- *
|
|
*
|
|
* linux/fs/devpts/inode.c
|
|
*
|
|
* Copyright 1998-2004 H. Peter Anvin -- All Rights Reserved
|
|
*
|
|
* This file is part of the Linux kernel and is made available under
|
|
* the terms of the GNU General Public License, version 2, or at your
|
|
* option, any later version, incorporated herein by reference.
|
|
*
|
|
* ------------------------------------------------------------------------- */
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/devpts_fs.h>
|
|
#include <linux/parser.h>
|
|
#include <linux/fsnotify.h>
|
|
#include <linux/seq_file.h>
|
|
|
|
#define DEVPTS_SUPER_MAGIC 0x1cd1
|
|
|
|
#define DEVPTS_DEFAULT_MODE 0600
|
|
|
|
static struct vfsmount *devpts_mnt;
|
|
static struct dentry *devpts_root;
|
|
|
|
static struct {
|
|
int setuid;
|
|
int setgid;
|
|
uid_t uid;
|
|
gid_t gid;
|
|
umode_t mode;
|
|
} config = {.mode = DEVPTS_DEFAULT_MODE};
|
|
|
|
enum {
|
|
Opt_uid, Opt_gid, Opt_mode,
|
|
Opt_err
|
|
};
|
|
|
|
static match_table_t tokens = {
|
|
{Opt_uid, "uid=%u"},
|
|
{Opt_gid, "gid=%u"},
|
|
{Opt_mode, "mode=%o"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
static int devpts_remount(struct super_block *sb, int *flags, char *data)
|
|
{
|
|
char *p;
|
|
|
|
config.setuid = 0;
|
|
config.setgid = 0;
|
|
config.uid = 0;
|
|
config.gid = 0;
|
|
config.mode = DEVPTS_DEFAULT_MODE;
|
|
|
|
while ((p = strsep(&data, ",")) != NULL) {
|
|
substring_t args[MAX_OPT_ARGS];
|
|
int token;
|
|
int option;
|
|
|
|
if (!*p)
|
|
continue;
|
|
|
|
token = match_token(p, tokens, args);
|
|
switch (token) {
|
|
case Opt_uid:
|
|
if (match_int(&args[0], &option))
|
|
return -EINVAL;
|
|
config.uid = option;
|
|
config.setuid = 1;
|
|
break;
|
|
case Opt_gid:
|
|
if (match_int(&args[0], &option))
|
|
return -EINVAL;
|
|
config.gid = option;
|
|
config.setgid = 1;
|
|
break;
|
|
case Opt_mode:
|
|
if (match_octal(&args[0], &option))
|
|
return -EINVAL;
|
|
config.mode = option & S_IALLUGO;
|
|
break;
|
|
default:
|
|
printk(KERN_ERR "devpts: called with bogus options\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int devpts_show_options(struct seq_file *seq, struct vfsmount *vfs)
|
|
{
|
|
if (config.setuid)
|
|
seq_printf(seq, ",uid=%u", config.uid);
|
|
if (config.setgid)
|
|
seq_printf(seq, ",gid=%u", config.gid);
|
|
seq_printf(seq, ",mode=%03o", config.mode);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct super_operations devpts_sops = {
|
|
.statfs = simple_statfs,
|
|
.remount_fs = devpts_remount,
|
|
.show_options = devpts_show_options,
|
|
};
|
|
|
|
static int
|
|
devpts_fill_super(struct super_block *s, void *data, int silent)
|
|
{
|
|
struct inode * inode;
|
|
|
|
s->s_blocksize = 1024;
|
|
s->s_blocksize_bits = 10;
|
|
s->s_magic = DEVPTS_SUPER_MAGIC;
|
|
s->s_op = &devpts_sops;
|
|
s->s_time_gran = 1;
|
|
|
|
inode = new_inode(s);
|
|
if (!inode)
|
|
goto fail;
|
|
inode->i_ino = 1;
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
|
|
inode->i_blocks = 0;
|
|
inode->i_uid = inode->i_gid = 0;
|
|
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
|
|
inode->i_op = &simple_dir_inode_operations;
|
|
inode->i_fop = &simple_dir_operations;
|
|
inode->i_nlink = 2;
|
|
|
|
devpts_root = s->s_root = d_alloc_root(inode);
|
|
if (s->s_root)
|
|
return 0;
|
|
|
|
printk("devpts: get root dentry failed\n");
|
|
iput(inode);
|
|
fail:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int devpts_get_sb(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_single(fs_type, flags, data, devpts_fill_super, mnt);
|
|
}
|
|
|
|
static struct file_system_type devpts_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "devpts",
|
|
.get_sb = devpts_get_sb,
|
|
.kill_sb = kill_anon_super,
|
|
};
|
|
|
|
/*
|
|
* The normal naming convention is simply /dev/pts/<number>; this conforms
|
|
* to the System V naming convention
|
|
*/
|
|
|
|
static struct dentry *get_node(int num)
|
|
{
|
|
char s[12];
|
|
struct dentry *root = devpts_root;
|
|
mutex_lock(&root->d_inode->i_mutex);
|
|
return lookup_one_len(s, root, sprintf(s, "%d", num));
|
|
}
|
|
|
|
int devpts_pty_new(struct tty_struct *tty)
|
|
{
|
|
int number = tty->index;
|
|
struct tty_driver *driver = tty->driver;
|
|
dev_t device = MKDEV(driver->major, driver->minor_start+number);
|
|
struct dentry *dentry;
|
|
struct inode *inode = new_inode(devpts_mnt->mnt_sb);
|
|
|
|
/* We're supposed to be given the slave end of a pty */
|
|
BUG_ON(driver->type != TTY_DRIVER_TYPE_PTY);
|
|
BUG_ON(driver->subtype != PTY_TYPE_SLAVE);
|
|
|
|
if (!inode)
|
|
return -ENOMEM;
|
|
|
|
inode->i_ino = number+2;
|
|
inode->i_uid = config.setuid ? config.uid : current->fsuid;
|
|
inode->i_gid = config.setgid ? config.gid : current->fsgid;
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
|
|
init_special_inode(inode, S_IFCHR|config.mode, device);
|
|
inode->i_private = tty;
|
|
|
|
dentry = get_node(number);
|
|
if (!IS_ERR(dentry) && !dentry->d_inode) {
|
|
d_instantiate(dentry, inode);
|
|
fsnotify_create(devpts_root->d_inode, dentry);
|
|
}
|
|
|
|
mutex_unlock(&devpts_root->d_inode->i_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct tty_struct *devpts_get_tty(int number)
|
|
{
|
|
struct dentry *dentry = get_node(number);
|
|
struct tty_struct *tty;
|
|
|
|
tty = NULL;
|
|
if (!IS_ERR(dentry)) {
|
|
if (dentry->d_inode)
|
|
tty = dentry->d_inode->i_private;
|
|
dput(dentry);
|
|
}
|
|
|
|
mutex_unlock(&devpts_root->d_inode->i_mutex);
|
|
|
|
return tty;
|
|
}
|
|
|
|
void devpts_pty_kill(int number)
|
|
{
|
|
struct dentry *dentry = get_node(number);
|
|
|
|
if (!IS_ERR(dentry)) {
|
|
struct inode *inode = dentry->d_inode;
|
|
if (inode) {
|
|
inode->i_nlink--;
|
|
d_delete(dentry);
|
|
dput(dentry);
|
|
}
|
|
dput(dentry);
|
|
}
|
|
mutex_unlock(&devpts_root->d_inode->i_mutex);
|
|
}
|
|
|
|
static int __init init_devpts_fs(void)
|
|
{
|
|
int err = register_filesystem(&devpts_fs_type);
|
|
if (!err) {
|
|
devpts_mnt = kern_mount(&devpts_fs_type);
|
|
if (IS_ERR(devpts_mnt))
|
|
err = PTR_ERR(devpts_mnt);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void __exit exit_devpts_fs(void)
|
|
{
|
|
unregister_filesystem(&devpts_fs_type);
|
|
mntput(devpts_mnt);
|
|
}
|
|
|
|
module_init(init_devpts_fs)
|
|
module_exit(exit_devpts_fs)
|
|
MODULE_LICENSE("GPL");
|