/*
* proc_tty.c -- handles /proc/tty
*
* Copyright 1997, Theodore Ts'o
*/
#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/console.h>
#include <linux/seq_file.h>
#include <linux/fdtable.h>
#include <linux/bitops.h>
/*
* The /proc/tty directory inodes...
*/
static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
/*
* This is the handler for /proc/tty/drivers
*/
static void show_tty_range(struct seq_file *m, struct tty_driver *p,
dev_t from, int num)
{
seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
seq_printf(m, "/dev/%-8s ", p->name);
if (p->num > 1) {
seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
MINOR(from) + num - 1);
} else {
seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
}
switch (p->type) {
case TTY_DRIVER_TYPE_SYSTEM:
seq_printf(m, "system");
if (p->subtype == SYSTEM_TYPE_TTY)
seq_printf(m, ":/dev/tty");
else if (p->subtype == SYSTEM_TYPE_SYSCONS)
seq_printf(m, ":console");
else if (p->subtype == SYSTEM_TYPE_CONSOLE)
seq_printf(m, ":vtmaster");
break;
case TTY_DRIVER_TYPE_CONSOLE:
seq_printf(m, "console");
break;
case TTY_DRIVER_TYPE_SERIAL:
seq_printf(m, "serial");
break;
case TTY_DRIVER_TYPE_PTY:
if (p->subtype == PTY_TYPE_MASTER)
seq_printf(m, "pty:master");
else if (p->subtype == PTY_TYPE_SLAVE)
seq_printf(m, "pty:slave");
else
seq_printf(m, "pty");
break;
default:
seq_printf(m, "type:%d.%d", p->type, p->subtype);
}
seq_putc(m, '\n');
}
static int show_tty_driver(struct seq_file *m, void *v)
{
struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
dev_t from = MKDEV(p->major, p->minor_start);
dev_t to = from + p->num;
if (&p->tty_drivers == tty_drivers.next) {
/* pseudo-drivers first */
seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
seq_printf(m, "system:/dev/tty\n");
seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
seq_printf(m, "system:console\n");
#ifdef CONFIG_UNIX98_PTYS
seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
seq_printf(m, "system\n");
#endif
#ifdef CONFIG_VT
seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
seq_printf(m, "system:vtmaster\n");
#endif
}
while (MAJOR(from) < MAJOR(to)) {
dev_t next = MKDEV(MAJOR(from)+1, 0);
show_tty_range(m, p, from, next - from);
from = next;
}
if (from != to)
show_tty_range(m, p, from, to - from);
return 0;
}
/* iterator */
static void *t_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&tty_mutex);
return seq_list_start(&tty_drivers, *pos);
}
static void *t_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &tty_drivers, pos);
}
static void t_stop(struct seq_file *m, void *v)
{
mutex_unlock(&tty_mutex);
}
static const struct seq_operations tty_drivers_op = {
.start = t_start,
.next = t_next,
.stop = t_stop,
.show = show_tty_driver
};
static int tty_drivers_open(struct inode *inode, struct file *file)
{
return seq_open(file, &tty_drivers_op);
}
static const struct file_operations proc_tty_drivers_operations = {
.open = tty_drivers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* The device ID of file descriptor 0 of the current reading
* task if a character device...
*/
static dev_t current_dev;
/*
* This is the handler for /proc/tty/consoles
*/
static int show_console_dev(struct seq_file *m, void *v)
{
const struct tty_driver *driver;
struct console *con;
int index, len;
char flags[10];
dev_t dev;
if (v == SEQ_START_TOKEN)
return 0;
con = (struct console *)v;
if (!con)
return 0;
driver = con->device(con, &index);
if (!driver)
return 0;
dev = MKDEV(driver->major, driver->minor_start) + index;
index = 0;
if (con->flags & CON_ENABLED)
flags[index++] = 'E';
if (con->flags & CON_CONSDEV)
flags[index++] = 'C';
if (con->flags & CON_BOOT)
flags[index++] = 'B';
if (con->flags & CON_PRINTBUFFER)
flags[index++] = 'p';
if (con->flags & CON_BRL)
flags[index++] = 'b';
if (con->flags & CON_ANYTIME)
flags[index++] = 'a';
if (current_dev == dev)
flags[index++] = '*';
flags[index] = 0;
seq_printf(m, "%s%d%n", con->name, con->index, &len);
len = 21 - len;
if (len < 1)
len = 1;
seq_printf(m, "%*c", len, ' ');
seq_printf(m, "%c%c%c (%s)%n", con->read ? 'R' : '-',
con->write ? 'W' : '-', con->unblank ? 'U' : '-',
flags, &len);
len = 13 - len;
if (len < 1)
len = 1;
seq_printf(m, "%*c%4d:%d\n", len, ' ', MAJOR(dev), MINOR(dev));
return 0;
}
/* iterator for consoles */
static void *c_start(struct seq_file *m, loff_t *pos)
{
struct console *con;
loff_t off = 0;
if (*pos == 0)
return SEQ_START_TOKEN;
acquire_console_sem();
for (con = console_drivers; con; con = con->next) {
if (!con->device)
continue;
if (++off == *pos)
break;
}
release_console_sem();
return con;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
struct console *con;
acquire_console_sem();
if (v == SEQ_START_TOKEN)
con = console_drivers;
else
con = ((struct console *)v)->next;
for (; con; con = con->next) {
if (!con->device)
continue;
++*pos;
break;
}
release_console_sem();
return con;
}
static void c_stop(struct seq_file *m, void *v)
{
}
static const struct seq_operations tty_consoles_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_console_dev
};
/*
* Used for open /proc/tty/consoles. Before this detect
* the device ID of file descriptor 0 of the current
* reading task if a character device...
*/
static int tty_consoles_open(struct inode *inode, struct file *file)
{
struct files_struct *curfiles;
current_dev = 0;
curfiles = get_files_struct(current);
if (curfiles) {
const struct file *curfp;
spin_lock(&curfiles->file_lock);
curfp = fcheck_files(curfiles, 0);
if (curfp && curfp->private_data) {
const struct inode *inode;
dget(curfp->f_dentry);
inode = curfp->f_dentry->d_inode;
if (S_ISCHR(inode->i_mode)) {
struct tty_struct *tty;
tty = (struct tty_struct *)curfp->private_data;
if (tty && tty->magic == TTY_MAGIC) {
tty = tty_pair_get_tty(tty);
current_dev = tty_devnum(tty);
}
}
dput(curfp->f_dentry);
}
spin_unlock(&curfiles->file_lock);
put_files_struct(curfiles);
}
return seq_open(file, &tty_consoles_op);
}
static const struct file_operations proc_tty_consoles_operations = {
.open = tty_consoles_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* This function is called by tty_register_driver() to handle
* registering the driver's /proc handler into /proc/tty/driver/<foo>
*/
void proc_tty_register_driver(struct tty_driver *driver)
{
struct proc_dir_entry *ent;
if (!driver->driver_name || driver->proc_entry ||
!driver->ops->proc_fops)
return;
ent = proc_create_data(driver->driver_name, 0, proc_tty_driver,
driver->ops->proc_fops, driver);
driver->proc_entry = ent;
}
/*
* This function is called by tty_unregister_driver()
*/
void proc_tty_unregister_driver(struct tty_driver *driver)
{
struct proc_dir_entry *ent;
ent = driver->proc_entry;
if (!ent)
return;
remove_proc_entry(driver->driver_name, proc_tty_driver);
driver->proc_entry = NULL;
}
/*
* Called by proc_root_init() to initialize the /proc/tty subtree
*/
void __init proc_tty_init(void)
{
if (!proc_mkdir("tty", NULL))
return;
proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
/*
* /proc/tty/driver/serial reveals the exact character counts for
* serial links which is just too easy to abuse for inferring
* password lengths and inter-keystroke timings during password
* entry.
*/
proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
proc_create("tty/consoles", 0, NULL, &proc_tty_consoles_operations);
}
