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179 lines
4.5 KiB
179 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* proc_tty.c -- handles /proc/tty |
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* |
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* Copyright 1997, Theodore Ts'o |
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*/ |
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#include <linux/uaccess.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/errno.h> |
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#include <linux/time.h> |
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#include <linux/proc_fs.h> |
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#include <linux/stat.h> |
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#include <linux/tty.h> |
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#include <linux/seq_file.h> |
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#include <linux/bitops.h> |
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#include "internal.h" |
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/* |
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* The /proc/tty directory inodes... |
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*/ |
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static struct proc_dir_entry *proc_tty_driver; |
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/* |
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* This is the handler for /proc/tty/drivers |
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*/ |
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static void show_tty_range(struct seq_file *m, struct tty_driver *p, |
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dev_t from, int num) |
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{ |
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seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown"); |
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seq_printf(m, "/dev/%-8s ", p->name); |
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if (p->num > 1) { |
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seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from), |
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MINOR(from) + num - 1); |
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} else { |
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seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from)); |
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} |
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switch (p->type) { |
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case TTY_DRIVER_TYPE_SYSTEM: |
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seq_puts(m, "system"); |
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if (p->subtype == SYSTEM_TYPE_TTY) |
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seq_puts(m, ":/dev/tty"); |
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else if (p->subtype == SYSTEM_TYPE_SYSCONS) |
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seq_puts(m, ":console"); |
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else if (p->subtype == SYSTEM_TYPE_CONSOLE) |
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seq_puts(m, ":vtmaster"); |
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break; |
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case TTY_DRIVER_TYPE_CONSOLE: |
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seq_puts(m, "console"); |
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break; |
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case TTY_DRIVER_TYPE_SERIAL: |
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seq_puts(m, "serial"); |
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break; |
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case TTY_DRIVER_TYPE_PTY: |
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if (p->subtype == PTY_TYPE_MASTER) |
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seq_puts(m, "pty:master"); |
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else if (p->subtype == PTY_TYPE_SLAVE) |
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seq_puts(m, "pty:slave"); |
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else |
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seq_puts(m, "pty"); |
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break; |
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default: |
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seq_printf(m, "type:%d.%d", p->type, p->subtype); |
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} |
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seq_putc(m, '\n'); |
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} |
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static int show_tty_driver(struct seq_file *m, void *v) |
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{ |
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struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers); |
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dev_t from = MKDEV(p->major, p->minor_start); |
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dev_t to = from + p->num; |
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if (&p->tty_drivers == tty_drivers.next) { |
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/* pseudo-drivers first */ |
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seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty"); |
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seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0); |
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seq_puts(m, "system:/dev/tty\n"); |
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seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console"); |
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seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1); |
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seq_puts(m, "system:console\n"); |
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#ifdef CONFIG_UNIX98_PTYS |
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seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx"); |
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seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2); |
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seq_puts(m, "system\n"); |
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#endif |
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#ifdef CONFIG_VT |
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seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0"); |
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seq_printf(m, "%3d %7d ", TTY_MAJOR, 0); |
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seq_puts(m, "system:vtmaster\n"); |
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#endif |
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} |
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while (MAJOR(from) < MAJOR(to)) { |
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dev_t next = MKDEV(MAJOR(from)+1, 0); |
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show_tty_range(m, p, from, next - from); |
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from = next; |
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} |
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if (from != to) |
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show_tty_range(m, p, from, to - from); |
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return 0; |
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} |
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/* iterator */ |
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static void *t_start(struct seq_file *m, loff_t *pos) |
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{ |
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mutex_lock(&tty_mutex); |
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return seq_list_start(&tty_drivers, *pos); |
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} |
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static void *t_next(struct seq_file *m, void *v, loff_t *pos) |
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{ |
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return seq_list_next(v, &tty_drivers, pos); |
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} |
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static void t_stop(struct seq_file *m, void *v) |
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{ |
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mutex_unlock(&tty_mutex); |
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} |
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static const struct seq_operations tty_drivers_op = { |
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.start = t_start, |
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.next = t_next, |
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.stop = t_stop, |
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.show = show_tty_driver |
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}; |
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/* |
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* This function is called by tty_register_driver() to handle |
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* registering the driver's /proc handler into /proc/tty/driver/<foo> |
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*/ |
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void proc_tty_register_driver(struct tty_driver *driver) |
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{ |
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struct proc_dir_entry *ent; |
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if (!driver->driver_name || driver->proc_entry || |
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!driver->ops->proc_show) |
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return; |
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ent = proc_create_single_data(driver->driver_name, 0, proc_tty_driver, |
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driver->ops->proc_show, driver); |
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driver->proc_entry = ent; |
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} |
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/* |
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* This function is called by tty_unregister_driver() |
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*/ |
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void proc_tty_unregister_driver(struct tty_driver *driver) |
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{ |
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struct proc_dir_entry *ent; |
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ent = driver->proc_entry; |
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if (!ent) |
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return; |
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remove_proc_entry(ent->name, proc_tty_driver); |
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driver->proc_entry = NULL; |
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} |
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/* |
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* Called by proc_root_init() to initialize the /proc/tty subtree |
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*/ |
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void __init proc_tty_init(void) |
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{ |
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if (!proc_mkdir("tty", NULL)) |
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return; |
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proc_mkdir("tty/ldisc", NULL); /* Preserved: it's userspace visible */ |
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/* |
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* /proc/tty/driver/serial reveals the exact character counts for |
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* serial links which is just too easy to abuse for inferring |
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* password lengths and inter-keystroke timings during password |
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* entry. |
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*/ |
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proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL); |
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proc_create_seq("tty/ldiscs", 0, NULL, &tty_ldiscs_seq_ops); |
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proc_create_seq("tty/drivers", 0, NULL, &tty_drivers_op); |
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}
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