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-rw-r--r--fs/proc/proc_tty.c242
1 files changed, 242 insertions, 0 deletions
diff --git a/fs/proc/proc_tty.c b/fs/proc/proc_tty.c
new file mode 100644
index 000000000000..15c4455b09eb
--- /dev/null
+++ b/fs/proc/proc_tty.c
@@ -0,0 +1,242 @@
1/*
2 * proc_tty.c -- handles /proc/tty
3 *
4 * Copyright 1997, Theodore Ts'o
5 */
6
7#include <asm/uaccess.h>
8
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
18static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
19 int count, int *eof, void *data);
20
21/*
22 * The /proc/tty directory inodes...
23 */
24static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
25
26/*
27 * This is the handler for /proc/tty/drivers
28 */
29static void show_tty_range(struct seq_file *m, struct tty_driver *p,
30 dev_t from, int num)
31{
32 seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
33 seq_printf(m, "/dev/%-8s ", p->name);
34 if (p->num > 1) {
35 seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
36 MINOR(from) + num - 1);
37 } else {
38 seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
39 }
40 switch (p->type) {
41 case TTY_DRIVER_TYPE_SYSTEM:
42 seq_printf(m, "system");
43 if (p->subtype == SYSTEM_TYPE_TTY)
44 seq_printf(m, ":/dev/tty");
45 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
46 seq_printf(m, ":console");
47 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
48 seq_printf(m, ":vtmaster");
49 break;
50 case TTY_DRIVER_TYPE_CONSOLE:
51 seq_printf(m, "console");
52 break;
53 case TTY_DRIVER_TYPE_SERIAL:
54 seq_printf(m, "serial");
55 break;
56 case TTY_DRIVER_TYPE_PTY:
57 if (p->subtype == PTY_TYPE_MASTER)
58 seq_printf(m, "pty:master");
59 else if (p->subtype == PTY_TYPE_SLAVE)
60 seq_printf(m, "pty:slave");
61 else
62 seq_printf(m, "pty");
63 break;
64 default:
65 seq_printf(m, "type:%d.%d", p->type, p->subtype);
66 }
67 seq_putc(m, '\n');
68}
69
70static int show_tty_driver(struct seq_file *m, void *v)
71{
72 struct tty_driver *p = v;
73 dev_t from = MKDEV(p->major, p->minor_start);
74 dev_t to = from + p->num;
75
76 if (&p->tty_drivers == tty_drivers.next) {
77 /* pseudo-drivers first */
78 seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
79 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
80 seq_printf(m, "system:/dev/tty\n");
81 seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
82 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
83 seq_printf(m, "system:console\n");
84#ifdef CONFIG_UNIX98_PTYS
85 seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
86 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
87 seq_printf(m, "system\n");
88#endif
89#ifdef CONFIG_VT
90 seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
91 seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
92 seq_printf(m, "system:vtmaster\n");
93#endif
94 }
95
96 while (MAJOR(from) < MAJOR(to)) {
97 dev_t next = MKDEV(MAJOR(from)+1, 0);
98 show_tty_range(m, p, from, next - from);
99 from = next;
100 }
101 if (from != to)
102 show_tty_range(m, p, from, to - from);
103 return 0;
104}
105
106/* iterator */
107static void *t_start(struct seq_file *m, loff_t *pos)
108{
109 struct list_head *p;
110 loff_t l = *pos;
111 list_for_each(p, &tty_drivers)
112 if (!l--)
113 return list_entry(p, struct tty_driver, tty_drivers);
114 return NULL;
115}
116
117static void *t_next(struct seq_file *m, void *v, loff_t *pos)
118{
119 struct list_head *p = ((struct tty_driver *)v)->tty_drivers.next;
120 (*pos)++;
121 return p==&tty_drivers ? NULL :
122 list_entry(p, struct tty_driver, tty_drivers);
123}
124
125static void t_stop(struct seq_file *m, void *v)
126{
127}
128
129static struct seq_operations tty_drivers_op = {
130 .start = t_start,
131 .next = t_next,
132 .stop = t_stop,
133 .show = show_tty_driver
134};
135
136static int tty_drivers_open(struct inode *inode, struct file *file)
137{
138 return seq_open(file, &tty_drivers_op);
139}
140
141static struct file_operations proc_tty_drivers_operations = {
142 .open = tty_drivers_open,
143 .read = seq_read,
144 .llseek = seq_lseek,
145 .release = seq_release,
146};
147
148/*
149 * This is the handler for /proc/tty/ldiscs
150 */
151static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
152 int count, int *eof, void *data)
153{
154 int i;
155 int len = 0;
156 off_t begin = 0;
157 struct tty_ldisc *ld;
158
159 for (i=0; i < NR_LDISCS; i++) {
160 ld = tty_ldisc_get(i);
161 if (ld == NULL)
162 continue;
163 len += sprintf(page+len, "%-10s %2d\n",
164 ld->name ? ld->name : "???", i);
165 tty_ldisc_put(i);
166 if (len+begin > off+count)
167 break;
168 if (len+begin < off) {
169 begin += len;
170 len = 0;
171 }
172 }
173 if (i >= NR_LDISCS)
174 *eof = 1;
175 if (off >= len+begin)
176 return 0;
177 *start = page + (off-begin);
178 return ((count < begin+len-off) ? count : begin+len-off);
179}
180
181/*
182 * This function is called by tty_register_driver() to handle
183 * registering the driver's /proc handler into /proc/tty/driver/<foo>
184 */
185void proc_tty_register_driver(struct tty_driver *driver)
186{
187 struct proc_dir_entry *ent;
188
189 if ((!driver->read_proc && !driver->write_proc) ||
190 !driver->driver_name ||
191 driver->proc_entry)
192 return;
193
194 ent = create_proc_entry(driver->driver_name, 0, proc_tty_driver);
195 if (!ent)
196 return;
197 ent->read_proc = driver->read_proc;
198 ent->write_proc = driver->write_proc;
199 ent->owner = driver->owner;
200 ent->data = driver;
201
202 driver->proc_entry = ent;
203}
204
205/*
206 * This function is called by tty_unregister_driver()
207 */
208void proc_tty_unregister_driver(struct tty_driver *driver)
209{
210 struct proc_dir_entry *ent;
211
212 ent = driver->proc_entry;
213 if (!ent)
214 return;
215
216 remove_proc_entry(driver->driver_name, proc_tty_driver);
217
218 driver->proc_entry = NULL;
219}
220
221/*
222 * Called by proc_root_init() to initialize the /proc/tty subtree
223 */
224void __init proc_tty_init(void)
225{
226 struct proc_dir_entry *entry;
227 if (!proc_mkdir("tty", NULL))
228 return;
229 proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
230 /*
231 * /proc/tty/driver/serial reveals the exact character counts for
232 * serial links which is just too easy to abuse for inferring
233 * password lengths and inter-keystroke timings during password
234 * entry.
235 */
236 proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR | S_IXUSR, NULL);
237
238 create_proc_read_entry("tty/ldiscs", 0, NULL, tty_ldiscs_read_proc, NULL);
239 entry = create_proc_entry("tty/drivers", 0, NULL);
240 if (entry)
241 entry->proc_fops = &proc_tty_drivers_operations;
242}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-13 21:22:21 -0500