Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * proc_tty.c -- handles /proc/tty | |
4 | * | |
5 | * Copyright 1997, Theodore Ts'o | |
6 | */ | |
7 | ||
7c0f6ba6 | 8 | #include <linux/uaccess.h> |
b640a89d | 9 | #include <linux/module.h> |
1da177e4 LT |
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> | |
c79dde62 | 18 | #include "internal.h" |
1da177e4 | 19 | |
1da177e4 LT |
20 | /* |
21 | * The /proc/tty directory inodes... | |
22 | */ | |
849d20a1 | 23 | static struct proc_dir_entry *proc_tty_driver; |
1da177e4 LT |
24 | |
25 | /* | |
26 | * This is the handler for /proc/tty/drivers | |
27 | */ | |
28 | static 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: | |
9d6de12f | 41 | seq_puts(m, "system"); |
1da177e4 | 42 | if (p->subtype == SYSTEM_TYPE_TTY) |
9d6de12f | 43 | seq_puts(m, ":/dev/tty"); |
1da177e4 | 44 | else if (p->subtype == SYSTEM_TYPE_SYSCONS) |
9d6de12f | 45 | seq_puts(m, ":console"); |
1da177e4 | 46 | else if (p->subtype == SYSTEM_TYPE_CONSOLE) |
9d6de12f | 47 | seq_puts(m, ":vtmaster"); |
1da177e4 LT |
48 | break; |
49 | case TTY_DRIVER_TYPE_CONSOLE: | |
9d6de12f | 50 | seq_puts(m, "console"); |
1da177e4 LT |
51 | break; |
52 | case TTY_DRIVER_TYPE_SERIAL: | |
9d6de12f | 53 | seq_puts(m, "serial"); |
1da177e4 LT |
54 | break; |
55 | case TTY_DRIVER_TYPE_PTY: | |
56 | if (p->subtype == PTY_TYPE_MASTER) | |
9d6de12f | 57 | seq_puts(m, "pty:master"); |
1da177e4 | 58 | else if (p->subtype == PTY_TYPE_SLAVE) |
9d6de12f | 59 | seq_puts(m, "pty:slave"); |
1da177e4 | 60 | else |
9d6de12f | 61 | seq_puts(m, "pty"); |
1da177e4 LT |
62 | break; |
63 | default: | |
64 | seq_printf(m, "type:%d.%d", p->type, p->subtype); | |
65 | } | |
66 | seq_putc(m, '\n'); | |
67 | } | |
68 | ||
69 | static int show_tty_driver(struct seq_file *m, void *v) | |
70 | { | |
25216b00 | 71 | struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers); |
1da177e4 LT |
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); | |
9d6de12f | 79 | seq_puts(m, "system:/dev/tty\n"); |
1da177e4 LT |
80 | seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console"); |
81 | seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1); | |
9d6de12f | 82 | seq_puts(m, "system:console\n"); |
1da177e4 LT |
83 | #ifdef CONFIG_UNIX98_PTYS |
84 | seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx"); | |
85 | seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2); | |
9d6de12f | 86 | seq_puts(m, "system\n"); |
1da177e4 LT |
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); | |
9d6de12f | 91 | seq_puts(m, "system:vtmaster\n"); |
1da177e4 LT |
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 */ | |
106 | static void *t_start(struct seq_file *m, loff_t *pos) | |
107 | { | |
ca509f69 | 108 | mutex_lock(&tty_mutex); |
25216b00 | 109 | return seq_list_start(&tty_drivers, *pos); |
1da177e4 LT |
110 | } |
111 | ||
112 | static void *t_next(struct seq_file *m, void *v, loff_t *pos) | |
113 | { | |
25216b00 | 114 | return seq_list_next(v, &tty_drivers, pos); |
1da177e4 LT |
115 | } |
116 | ||
117 | static void t_stop(struct seq_file *m, void *v) | |
118 | { | |
ca509f69 | 119 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
120 | } |
121 | ||
03a44825 | 122 | static const struct seq_operations tty_drivers_op = { |
1da177e4 LT |
123 | .start = t_start, |
124 | .next = t_next, | |
125 | .stop = t_stop, | |
126 | .show = show_tty_driver | |
127 | }; | |
128 | ||
129 | static int tty_drivers_open(struct inode *inode, struct file *file) | |
130 | { | |
131 | return seq_open(file, &tty_drivers_op); | |
132 | } | |
133 | ||
00977a59 | 134 | static const struct file_operations proc_tty_drivers_operations = { |
1da177e4 LT |
135 | .open = tty_drivers_open, |
136 | .read = seq_read, | |
137 | .llseek = seq_lseek, | |
138 | .release = seq_release, | |
139 | }; | |
140 | ||
1da177e4 LT |
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 | */ | |
145 | void proc_tty_register_driver(struct tty_driver *driver) | |
146 | { | |
147 | struct proc_dir_entry *ent; | |
148 | ||
0f043a81 AD |
149 | if (!driver->driver_name || driver->proc_entry || |
150 | !driver->ops->proc_fops) | |
1da177e4 LT |
151 | return; |
152 | ||
0f043a81 AD |
153 | ent = proc_create_data(driver->driver_name, 0, proc_tty_driver, |
154 | driver->ops->proc_fops, driver); | |
1da177e4 LT |
155 | driver->proc_entry = ent; |
156 | } | |
157 | ||
158 | /* | |
159 | * This function is called by tty_unregister_driver() | |
160 | */ | |
161 | void 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 | ||
c79dde62 | 169 | remove_proc_entry(ent->name, proc_tty_driver); |
1da177e4 LT |
170 | |
171 | driver->proc_entry = NULL; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Called by proc_root_init() to initialize the /proc/tty subtree | |
176 | */ | |
177 | void __init proc_tty_init(void) | |
178 | { | |
1da177e4 LT |
179 | if (!proc_mkdir("tty", NULL)) |
180 | return; | |
849d20a1 | 181 | proc_mkdir("tty/ldisc", NULL); /* Preserved: it's userspace visible */ |
1da177e4 LT |
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 | */ | |
b640a89d AD |
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); | |
0d5c9f5f | 190 | proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations); |
1da177e4 | 191 | } |