proc: convert /proc/tty/ldiscs to seq_file interface
[linux-2.6.git] / fs / proc / proc_tty.c
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  */
21 static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
22
23 /*
24  * This is the handler for /proc/tty/drivers
25  */
26 static 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_printf(m, "system");
40                 if (p->subtype == SYSTEM_TYPE_TTY)
41                         seq_printf(m, ":/dev/tty");
42                 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
43                         seq_printf(m, ":console");
44                 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
45                         seq_printf(m, ":vtmaster");
46                 break;
47         case TTY_DRIVER_TYPE_CONSOLE:
48                 seq_printf(m, "console");
49                 break;
50         case TTY_DRIVER_TYPE_SERIAL:
51                 seq_printf(m, "serial");
52                 break;
53         case TTY_DRIVER_TYPE_PTY:
54                 if (p->subtype == PTY_TYPE_MASTER)
55                         seq_printf(m, "pty:master");
56                 else if (p->subtype == PTY_TYPE_SLAVE)
57                         seq_printf(m, "pty:slave");
58                 else
59                         seq_printf(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
67 static 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_printf(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_printf(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_printf(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_printf(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 */
104 static 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
110 static void *t_next(struct seq_file *m, void *v, loff_t *pos)
111 {
112         return seq_list_next(v, &tty_drivers, pos);
113 }
114
115 static void t_stop(struct seq_file *m, void *v)
116 {
117         mutex_unlock(&tty_mutex);
118 }
119
120 static 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
127 static int tty_drivers_open(struct inode *inode, struct file *file)
128 {
129         return seq_open(file, &tty_drivers_op);
130 }
131
132 static 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 static void * tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
140 {
141         return (*pos < NR_LDISCS) ? pos : NULL;
142 }
143
144 static void * tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
145 {
146         (*pos)++;
147         return (*pos < NR_LDISCS) ? pos : NULL;
148 }
149
150 static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
151 {
152 }
153
154 static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
155 {
156         int i = *(loff_t *)v;
157         struct tty_ldisc *ld;
158         
159         ld = tty_ldisc_get(i);
160         if (ld == NULL)
161                 return 0;
162         seq_printf(m, "%-10s %2d\n", ld->name ? ld->name : "???", i);
163         tty_ldisc_put(i);
164         return 0;
165 }
166
167 static const struct seq_operations tty_ldiscs_seq_ops = {
168         .start  = tty_ldiscs_seq_start,
169         .next   = tty_ldiscs_seq_next,
170         .stop   = tty_ldiscs_seq_stop,
171         .show   = tty_ldiscs_seq_show,
172 };
173
174 static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
175 {
176         return seq_open(file, &tty_ldiscs_seq_ops);
177 }
178
179 static const struct file_operations tty_ldiscs_proc_fops = {
180         .owner          = THIS_MODULE,
181         .open           = proc_tty_ldiscs_open,
182         .read           = seq_read,
183         .llseek         = seq_lseek,
184         .release        = seq_release,
185 };
186
187 /*
188  * This function is called by tty_register_driver() to handle
189  * registering the driver's /proc handler into /proc/tty/driver/<foo>
190  */
191 void proc_tty_register_driver(struct tty_driver *driver)
192 {
193         struct proc_dir_entry *ent;
194                 
195         if ((!driver->read_proc && !driver->write_proc) ||
196             !driver->driver_name ||
197             driver->proc_entry)
198                 return;
199
200         ent = create_proc_entry(driver->driver_name, 0, proc_tty_driver);
201         if (!ent)
202                 return;
203         ent->read_proc = driver->read_proc;
204         ent->write_proc = driver->write_proc;
205         ent->owner = driver->owner;
206         ent->data = driver;
207
208         driver->proc_entry = ent;
209 }
210
211 /*
212  * This function is called by tty_unregister_driver()
213  */
214 void proc_tty_unregister_driver(struct tty_driver *driver)
215 {
216         struct proc_dir_entry *ent;
217
218         ent = driver->proc_entry;
219         if (!ent)
220                 return;
221                 
222         remove_proc_entry(driver->driver_name, proc_tty_driver);
223         
224         driver->proc_entry = NULL;
225 }
226
227 /*
228  * Called by proc_root_init() to initialize the /proc/tty subtree
229  */
230 void __init proc_tty_init(void)
231 {
232         if (!proc_mkdir("tty", NULL))
233                 return;
234         proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
235         /*
236          * /proc/tty/driver/serial reveals the exact character counts for
237          * serial links which is just too easy to abuse for inferring
238          * password lengths and inter-keystroke timings during password
239          * entry.
240          */
241         proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
242         proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
243         proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
244 }