1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * proc_tty.c -- handles /proc/tty
41da177e4SLinus Torvalds *
51da177e4SLinus Torvalds * Copyright 1997, Theodore Ts'o
61da177e4SLinus Torvalds */
7b640a89dSAlexey Dobriyan #include <linux/module.h>
81da177e4SLinus Torvalds #include <linux/init.h>
91da177e4SLinus Torvalds #include <linux/errno.h>
101da177e4SLinus Torvalds #include <linux/time.h>
111da177e4SLinus Torvalds #include <linux/proc_fs.h>
121da177e4SLinus Torvalds #include <linux/stat.h>
131da177e4SLinus Torvalds #include <linux/tty.h>
141da177e4SLinus Torvalds #include <linux/seq_file.h>
151da177e4SLinus Torvalds #include <linux/bitops.h>
16c79dde62Snixiaoming #include "internal.h"
171da177e4SLinus Torvalds
181da177e4SLinus Torvalds /*
191da177e4SLinus Torvalds * The /proc/tty directory inodes...
201da177e4SLinus Torvalds */
21849d20a1SAlexey Dobriyan static struct proc_dir_entry *proc_tty_driver;
221da177e4SLinus Torvalds
231da177e4SLinus Torvalds /*
241da177e4SLinus Torvalds * This is the handler for /proc/tty/drivers
251da177e4SLinus Torvalds */
show_tty_range(struct seq_file * m,struct tty_driver * p,dev_t from,int num)261da177e4SLinus Torvalds static void show_tty_range(struct seq_file *m, struct tty_driver *p,
271da177e4SLinus Torvalds dev_t from, int num)
281da177e4SLinus Torvalds {
291da177e4SLinus Torvalds seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
301da177e4SLinus Torvalds seq_printf(m, "/dev/%-8s ", p->name);
311da177e4SLinus Torvalds if (p->num > 1) {
321da177e4SLinus Torvalds seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
331da177e4SLinus Torvalds MINOR(from) + num - 1);
341da177e4SLinus Torvalds } else {
351da177e4SLinus Torvalds seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
361da177e4SLinus Torvalds }
371da177e4SLinus Torvalds switch (p->type) {
381da177e4SLinus Torvalds case TTY_DRIVER_TYPE_SYSTEM:
399d6de12fSAlexey Dobriyan seq_puts(m, "system");
401da177e4SLinus Torvalds if (p->subtype == SYSTEM_TYPE_TTY)
419d6de12fSAlexey Dobriyan seq_puts(m, ":/dev/tty");
421da177e4SLinus Torvalds else if (p->subtype == SYSTEM_TYPE_SYSCONS)
439d6de12fSAlexey Dobriyan seq_puts(m, ":console");
441da177e4SLinus Torvalds else if (p->subtype == SYSTEM_TYPE_CONSOLE)
459d6de12fSAlexey Dobriyan seq_puts(m, ":vtmaster");
461da177e4SLinus Torvalds break;
471da177e4SLinus Torvalds case TTY_DRIVER_TYPE_CONSOLE:
489d6de12fSAlexey Dobriyan seq_puts(m, "console");
491da177e4SLinus Torvalds break;
501da177e4SLinus Torvalds case TTY_DRIVER_TYPE_SERIAL:
519d6de12fSAlexey Dobriyan seq_puts(m, "serial");
521da177e4SLinus Torvalds break;
531da177e4SLinus Torvalds case TTY_DRIVER_TYPE_PTY:
541da177e4SLinus Torvalds if (p->subtype == PTY_TYPE_MASTER)
559d6de12fSAlexey Dobriyan seq_puts(m, "pty:master");
561da177e4SLinus Torvalds else if (p->subtype == PTY_TYPE_SLAVE)
579d6de12fSAlexey Dobriyan seq_puts(m, "pty:slave");
581da177e4SLinus Torvalds else
599d6de12fSAlexey Dobriyan seq_puts(m, "pty");
601da177e4SLinus Torvalds break;
611da177e4SLinus Torvalds default:
621da177e4SLinus Torvalds seq_printf(m, "type:%d.%d", p->type, p->subtype);
631da177e4SLinus Torvalds }
641da177e4SLinus Torvalds seq_putc(m, '\n');
651da177e4SLinus Torvalds }
661da177e4SLinus Torvalds
show_tty_driver(struct seq_file * m,void * v)671da177e4SLinus Torvalds static int show_tty_driver(struct seq_file *m, void *v)
681da177e4SLinus Torvalds {
6925216b00SPavel Emelianov struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
701da177e4SLinus Torvalds dev_t from = MKDEV(p->major, p->minor_start);
711da177e4SLinus Torvalds dev_t to = from + p->num;
721da177e4SLinus Torvalds
731da177e4SLinus Torvalds if (&p->tty_drivers == tty_drivers.next) {
741da177e4SLinus Torvalds /* pseudo-drivers first */
751da177e4SLinus Torvalds seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
761da177e4SLinus Torvalds seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
779d6de12fSAlexey Dobriyan seq_puts(m, "system:/dev/tty\n");
781da177e4SLinus Torvalds seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
791da177e4SLinus Torvalds seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
809d6de12fSAlexey Dobriyan seq_puts(m, "system:console\n");
811da177e4SLinus Torvalds #ifdef CONFIG_UNIX98_PTYS
821da177e4SLinus Torvalds seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
831da177e4SLinus Torvalds seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
849d6de12fSAlexey Dobriyan seq_puts(m, "system\n");
851da177e4SLinus Torvalds #endif
861da177e4SLinus Torvalds #ifdef CONFIG_VT
871da177e4SLinus Torvalds seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
881da177e4SLinus Torvalds seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
899d6de12fSAlexey Dobriyan seq_puts(m, "system:vtmaster\n");
901da177e4SLinus Torvalds #endif
911da177e4SLinus Torvalds }
921da177e4SLinus Torvalds
931da177e4SLinus Torvalds while (MAJOR(from) < MAJOR(to)) {
941da177e4SLinus Torvalds dev_t next = MKDEV(MAJOR(from)+1, 0);
951da177e4SLinus Torvalds show_tty_range(m, p, from, next - from);
961da177e4SLinus Torvalds from = next;
971da177e4SLinus Torvalds }
981da177e4SLinus Torvalds if (from != to)
991da177e4SLinus Torvalds show_tty_range(m, p, from, to - from);
1001da177e4SLinus Torvalds return 0;
1011da177e4SLinus Torvalds }
1021da177e4SLinus Torvalds
1031da177e4SLinus Torvalds /* iterator */
t_start(struct seq_file * m,loff_t * pos)1041da177e4SLinus Torvalds static void *t_start(struct seq_file *m, loff_t *pos)
1051da177e4SLinus Torvalds {
106ca509f69SAlexey Dobriyan mutex_lock(&tty_mutex);
10725216b00SPavel Emelianov return seq_list_start(&tty_drivers, *pos);
1081da177e4SLinus Torvalds }
1091da177e4SLinus Torvalds
t_next(struct seq_file * m,void * v,loff_t * pos)1101da177e4SLinus Torvalds static void *t_next(struct seq_file *m, void *v, loff_t *pos)
1111da177e4SLinus Torvalds {
11225216b00SPavel Emelianov return seq_list_next(v, &tty_drivers, pos);
1131da177e4SLinus Torvalds }
1141da177e4SLinus Torvalds
t_stop(struct seq_file * m,void * v)1151da177e4SLinus Torvalds static void t_stop(struct seq_file *m, void *v)
1161da177e4SLinus Torvalds {
117ca509f69SAlexey Dobriyan mutex_unlock(&tty_mutex);
1181da177e4SLinus Torvalds }
1191da177e4SLinus Torvalds
12003a44825SJan Engelhardt static const struct seq_operations tty_drivers_op = {
1211da177e4SLinus Torvalds .start = t_start,
1221da177e4SLinus Torvalds .next = t_next,
1231da177e4SLinus Torvalds .stop = t_stop,
1241da177e4SLinus Torvalds .show = show_tty_driver
1251da177e4SLinus Torvalds };
1261da177e4SLinus Torvalds
1271da177e4SLinus Torvalds /*
1281da177e4SLinus Torvalds * This function is called by tty_register_driver() to handle
1291da177e4SLinus Torvalds * registering the driver's /proc handler into /proc/tty/driver/<foo>
1301da177e4SLinus Torvalds */
proc_tty_register_driver(struct tty_driver * driver)1311da177e4SLinus Torvalds void proc_tty_register_driver(struct tty_driver *driver)
1321da177e4SLinus Torvalds {
1331da177e4SLinus Torvalds struct proc_dir_entry *ent;
1341da177e4SLinus Torvalds
1350f043a81SAlexey Dobriyan if (!driver->driver_name || driver->proc_entry ||
136*8a8dcabfSChristoph Hellwig !driver->ops->proc_show)
1371da177e4SLinus Torvalds return;
1381da177e4SLinus Torvalds
139*8a8dcabfSChristoph Hellwig ent = proc_create_single_data(driver->driver_name, 0, proc_tty_driver,
140*8a8dcabfSChristoph Hellwig driver->ops->proc_show, driver);
1411da177e4SLinus Torvalds driver->proc_entry = ent;
1421da177e4SLinus Torvalds }
1431da177e4SLinus Torvalds
1441da177e4SLinus Torvalds /*
1451da177e4SLinus Torvalds * This function is called by tty_unregister_driver()
1461da177e4SLinus Torvalds */
proc_tty_unregister_driver(struct tty_driver * driver)1471da177e4SLinus Torvalds void proc_tty_unregister_driver(struct tty_driver *driver)
1481da177e4SLinus Torvalds {
1491da177e4SLinus Torvalds struct proc_dir_entry *ent;
1501da177e4SLinus Torvalds
1511da177e4SLinus Torvalds ent = driver->proc_entry;
1521da177e4SLinus Torvalds if (!ent)
1531da177e4SLinus Torvalds return;
1541da177e4SLinus Torvalds
155c79dde62Snixiaoming remove_proc_entry(ent->name, proc_tty_driver);
1561da177e4SLinus Torvalds
1571da177e4SLinus Torvalds driver->proc_entry = NULL;
1581da177e4SLinus Torvalds }
1591da177e4SLinus Torvalds
1601da177e4SLinus Torvalds /*
1611da177e4SLinus Torvalds * Called by proc_root_init() to initialize the /proc/tty subtree
1621da177e4SLinus Torvalds */
proc_tty_init(void)1631da177e4SLinus Torvalds void __init proc_tty_init(void)
1641da177e4SLinus Torvalds {
1651da177e4SLinus Torvalds if (!proc_mkdir("tty", NULL))
1661da177e4SLinus Torvalds return;
167849d20a1SAlexey Dobriyan proc_mkdir("tty/ldisc", NULL); /* Preserved: it's userspace visible */
1681da177e4SLinus Torvalds /*
1691da177e4SLinus Torvalds * /proc/tty/driver/serial reveals the exact character counts for
1701da177e4SLinus Torvalds * serial links which is just too easy to abuse for inferring
1711da177e4SLinus Torvalds * password lengths and inter-keystroke timings during password
1721da177e4SLinus Torvalds * entry.
1731da177e4SLinus Torvalds */
1741da177e4SLinus Torvalds proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
175fddda2b7SChristoph Hellwig proc_create_seq("tty/ldiscs", 0, NULL, &tty_ldiscs_seq_ops);
176fddda2b7SChristoph Hellwig proc_create_seq("tty/drivers", 0, NULL, &tty_drivers_op);
1771da177e4SLinus Torvalds }
178