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1/*
2 * proc_tty.c -- handles /proc/tty
3 *
4 * Copyright 1997, Theodore Ts'o
5 */
6
7#include <asm/uaccess.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/errno.h>
11#include <linux/time.h>
12#include <linux/proc_fs.h>
13#include <linux/stat.h>
14#include <linux/tty.h>
15#include <linux/seq_file.h>
16#include <linux/bitops.h>
17
18/*
19 * The /proc/tty directory inodes...
20 */
21static struct proc_dir_entry *proc_tty_driver;
22
23/*
24 * This is the handler for /proc/tty/drivers
25 */
26static void show_tty_range(struct seq_file *m, struct tty_driver *p,
27 dev_t from, int num)
28{
29 seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
30 seq_printf(m, "/dev/%-8s ", p->name);
31 if (p->num > 1) {
32 seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
33 MINOR(from) + num - 1);
34 } else {
35 seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
36 }
37 switch (p->type) {
38 case TTY_DRIVER_TYPE_SYSTEM:
39 seq_puts(m, "system");
40 if (p->subtype == SYSTEM_TYPE_TTY)
41 seq_puts(m, ":/dev/tty");
42 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
43 seq_puts(m, ":console");
44 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
45 seq_puts(m, ":vtmaster");
46 break;
47 case TTY_DRIVER_TYPE_CONSOLE:
48 seq_puts(m, "console");
49 break;
50 case TTY_DRIVER_TYPE_SERIAL:
51 seq_puts(m, "serial");
52 break;
53 case TTY_DRIVER_TYPE_PTY:
54 if (p->subtype == PTY_TYPE_MASTER)
55 seq_puts(m, "pty:master");
56 else if (p->subtype == PTY_TYPE_SLAVE)
57 seq_puts(m, "pty:slave");
58 else
59 seq_puts(m, "pty");
60 break;
61 default:
62 seq_printf(m, "type:%d.%d", p->type, p->subtype);
63 }
64 seq_putc(m, '\n');
65}
66
67static int show_tty_driver(struct seq_file *m, void *v)
68{
69 struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
70 dev_t from = MKDEV(p->major, p->minor_start);
71 dev_t to = from + p->num;
72
73 if (&p->tty_drivers == tty_drivers.next) {
74 /* pseudo-drivers first */
75 seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
76 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
77 seq_puts(m, "system:/dev/tty\n");
78 seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
79 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
80 seq_puts(m, "system:console\n");
81#ifdef CONFIG_UNIX98_PTYS
82 seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
83 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
84 seq_puts(m, "system\n");
85#endif
86#ifdef CONFIG_VT
87 seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
88 seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
89 seq_puts(m, "system:vtmaster\n");
90#endif
91 }
92
93 while (MAJOR(from) < MAJOR(to)) {
94 dev_t next = MKDEV(MAJOR(from)+1, 0);
95 show_tty_range(m, p, from, next - from);
96 from = next;
97 }
98 if (from != to)
99 show_tty_range(m, p, from, to - from);
100 return 0;
101}
102
103/* iterator */
104static void *t_start(struct seq_file *m, loff_t *pos)
105{
106 mutex_lock(&tty_mutex);
107 return seq_list_start(&tty_drivers, *pos);
108}
109
110static void *t_next(struct seq_file *m, void *v, loff_t *pos)
111{
112 return seq_list_next(v, &tty_drivers, pos);
113}
114
115static void t_stop(struct seq_file *m, void *v)
116{
117 mutex_unlock(&tty_mutex);
118}
119
120static const struct seq_operations tty_drivers_op = {
121 .start = t_start,
122 .next = t_next,
123 .stop = t_stop,
124 .show = show_tty_driver
125};
126
127static int tty_drivers_open(struct inode *inode, struct file *file)
128{
129 return seq_open(file, &tty_drivers_op);
130}
131
132static const struct file_operations proc_tty_drivers_operations = {
133 .open = tty_drivers_open,
134 .read = seq_read,
135 .llseek = seq_lseek,
136 .release = seq_release,
137};
138
139/*
140 * This function is called by tty_register_driver() to handle
141 * registering the driver's /proc handler into /proc/tty/driver/<foo>
142 */
143void proc_tty_register_driver(struct tty_driver *driver)
144{
145 struct proc_dir_entry *ent;
146
147 if (!driver->driver_name || driver->proc_entry ||
148 !driver->ops->proc_fops)
149 return;
150
151 ent = proc_create_data(driver->driver_name, 0, proc_tty_driver,
152 driver->ops->proc_fops, driver);
153 driver->proc_entry = ent;
154}
155
156/*
157 * This function is called by tty_unregister_driver()
158 */
159void proc_tty_unregister_driver(struct tty_driver *driver)
160{
161 struct proc_dir_entry *ent;
162
163 ent = driver->proc_entry;
164 if (!ent)
165 return;
166
167 remove_proc_entry(driver->driver_name, proc_tty_driver);
168
169 driver->proc_entry = NULL;
170}
171
172/*
173 * Called by proc_root_init() to initialize the /proc/tty subtree
174 */
175void __init proc_tty_init(void)
176{
177 if (!proc_mkdir("tty", NULL))
178 return;
179 proc_mkdir("tty/ldisc", NULL); /* Preserved: it's userspace visible */
180 /*
181 * /proc/tty/driver/serial reveals the exact character counts for
182 * serial links which is just too easy to abuse for inferring
183 * password lengths and inter-keystroke timings during password
184 * entry.
185 */
186 proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
187 proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
188 proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
189}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * proc_tty.c -- handles /proc/tty
4 *
5 * Copyright 1997, Theodore Ts'o
6 */
7
8#include <linux/uaccess.h>
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/time.h>
13#include <linux/proc_fs.h>
14#include <linux/stat.h>
15#include <linux/tty.h>
16#include <linux/seq_file.h>
17#include <linux/bitops.h>
18#include "internal.h"
19
20/*
21 * The /proc/tty directory inodes...
22 */
23static struct proc_dir_entry *proc_tty_driver;
24
25/*
26 * This is the handler for /proc/tty/drivers
27 */
28static void show_tty_range(struct seq_file *m, struct tty_driver *p,
29 dev_t from, int num)
30{
31 seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
32 seq_printf(m, "/dev/%-8s ", p->name);
33 if (p->num > 1) {
34 seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
35 MINOR(from) + num - 1);
36 } else {
37 seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
38 }
39 switch (p->type) {
40 case TTY_DRIVER_TYPE_SYSTEM:
41 seq_puts(m, "system");
42 if (p->subtype == SYSTEM_TYPE_TTY)
43 seq_puts(m, ":/dev/tty");
44 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
45 seq_puts(m, ":console");
46 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
47 seq_puts(m, ":vtmaster");
48 break;
49 case TTY_DRIVER_TYPE_CONSOLE:
50 seq_puts(m, "console");
51 break;
52 case TTY_DRIVER_TYPE_SERIAL:
53 seq_puts(m, "serial");
54 break;
55 case TTY_DRIVER_TYPE_PTY:
56 if (p->subtype == PTY_TYPE_MASTER)
57 seq_puts(m, "pty:master");
58 else if (p->subtype == PTY_TYPE_SLAVE)
59 seq_puts(m, "pty:slave");
60 else
61 seq_puts(m, "pty");
62 break;
63 default:
64 seq_printf(m, "type:%d.%d", p->type, p->subtype);
65 }
66 seq_putc(m, '\n');
67}
68
69static int show_tty_driver(struct seq_file *m, void *v)
70{
71 struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
72 dev_t from = MKDEV(p->major, p->minor_start);
73 dev_t to = from + p->num;
74
75 if (&p->tty_drivers == tty_drivers.next) {
76 /* pseudo-drivers first */
77 seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
78 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
79 seq_puts(m, "system:/dev/tty\n");
80 seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
81 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
82 seq_puts(m, "system:console\n");
83#ifdef CONFIG_UNIX98_PTYS
84 seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
85 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
86 seq_puts(m, "system\n");
87#endif
88#ifdef CONFIG_VT
89 seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
90 seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
91 seq_puts(m, "system:vtmaster\n");
92#endif
93 }
94
95 while (MAJOR(from) < MAJOR(to)) {
96 dev_t next = MKDEV(MAJOR(from)+1, 0);
97 show_tty_range(m, p, from, next - from);
98 from = next;
99 }
100 if (from != to)
101 show_tty_range(m, p, from, to - from);
102 return 0;
103}
104
105/* iterator */
106static void *t_start(struct seq_file *m, loff_t *pos)
107{
108 mutex_lock(&tty_mutex);
109 return seq_list_start(&tty_drivers, *pos);
110}
111
112static void *t_next(struct seq_file *m, void *v, loff_t *pos)
113{
114 return seq_list_next(v, &tty_drivers, pos);
115}
116
117static void t_stop(struct seq_file *m, void *v)
118{
119 mutex_unlock(&tty_mutex);
120}
121
122static const struct seq_operations tty_drivers_op = {
123 .start = t_start,
124 .next = t_next,
125 .stop = t_stop,
126 .show = show_tty_driver
127};
128
129static int tty_drivers_open(struct inode *inode, struct file *file)
130{
131 return seq_open(file, &tty_drivers_op);
132}
133
134static const struct file_operations proc_tty_drivers_operations = {
135 .open = tty_drivers_open,
136 .read = seq_read,
137 .llseek = seq_lseek,
138 .release = seq_release,
139};
140
141/*
142 * This function is called by tty_register_driver() to handle
143 * registering the driver's /proc handler into /proc/tty/driver/<foo>
144 */
145void proc_tty_register_driver(struct tty_driver *driver)
146{
147 struct proc_dir_entry *ent;
148
149 if (!driver->driver_name || driver->proc_entry ||
150 !driver->ops->proc_fops)
151 return;
152
153 ent = proc_create_data(driver->driver_name, 0, proc_tty_driver,
154 driver->ops->proc_fops, driver);
155 driver->proc_entry = ent;
156}
157
158/*
159 * This function is called by tty_unregister_driver()
160 */
161void proc_tty_unregister_driver(struct tty_driver *driver)
162{
163 struct proc_dir_entry *ent;
164
165 ent = driver->proc_entry;
166 if (!ent)
167 return;
168
169 remove_proc_entry(ent->name, proc_tty_driver);
170
171 driver->proc_entry = NULL;
172}
173
174/*
175 * Called by proc_root_init() to initialize the /proc/tty subtree
176 */
177void __init proc_tty_init(void)
178{
179 if (!proc_mkdir("tty", NULL))
180 return;
181 proc_mkdir("tty/ldisc", NULL); /* Preserved: it's userspace visible */
182 /*
183 * /proc/tty/driver/serial reveals the exact character counts for
184 * serial links which is just too easy to abuse for inferring
185 * password lengths and inter-keystroke timings during password
186 * entry.
187 */
188 proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
189 proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
190 proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
191}