[people/ms/linux.git] / fs / proc / proc_tty.c

/*
 * proc_tty.c -- handles /proc/tty
 *
 * Copyright 1997, Theodore Ts'o
 */

#include <asm/uaccess.h>

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <linux/seq_file.h>
#include <linux/bitops.h>

static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
				int count, int *eof, void *data);

/*
 * The /proc/tty directory inodes...
 */
static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;

/*
 * This is the handler for /proc/tty/drivers
 */
static void show_tty_range(struct seq_file *m, struct tty_driver *p,
	dev_t from, int num)
{
	seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
	seq_printf(m, "/dev/%-8s ", p->name);
	if (p->num > 1) {
		seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
			MINOR(from) + num - 1);
	} else {
		seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
	}
	switch (p->type) {
	case TTY_DRIVER_TYPE_SYSTEM:
		seq_printf(m, "system");
		if (p->subtype == SYSTEM_TYPE_TTY)
			seq_printf(m, ":/dev/tty");
		else if (p->subtype == SYSTEM_TYPE_SYSCONS)
			seq_printf(m, ":console");
		else if (p->subtype == SYSTEM_TYPE_CONSOLE)
			seq_printf(m, ":vtmaster");
		break;
	case TTY_DRIVER_TYPE_CONSOLE:
		seq_printf(m, "console");
		break;
	case TTY_DRIVER_TYPE_SERIAL:
		seq_printf(m, "serial");
		break;
	case TTY_DRIVER_TYPE_PTY:
		if (p->subtype == PTY_TYPE_MASTER)
			seq_printf(m, "pty:master");
		else if (p->subtype == PTY_TYPE_SLAVE)
			seq_printf(m, "pty:slave");
		else
			seq_printf(m, "pty");
		break;
	default:
		seq_printf(m, "type:%d.%d", p->type, p->subtype);
	}
	seq_putc(m, '\n');
}

static int show_tty_driver(struct seq_file *m, void *v)
{
	struct tty_driver *p = v;
	dev_t from = MKDEV(p->major, p->minor_start);
	dev_t to = from + p->num;

	if (&p->tty_drivers == tty_drivers.next) {
		/* pseudo-drivers first */
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
		seq_printf(m, "system:/dev/tty\n");
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
		seq_printf(m, "system:console\n");
#ifdef CONFIG_UNIX98_PTYS
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
		seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
		seq_printf(m, "system\n");
#endif
#ifdef CONFIG_VT
		seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
		seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
		seq_printf(m, "system:vtmaster\n");
#endif
	}

	while (MAJOR(from) < MAJOR(to)) {
		dev_t next = MKDEV(MAJOR(from)+1, 0);
		show_tty_range(m, p, from, next - from);
		from = next;
	}
	if (from != to)
		show_tty_range(m, p, from, to - from);
	return 0;
}

/* iterator */
static void *t_start(struct seq_file *m, loff_t *pos)
{
	struct list_head *p;
	loff_t l = *pos;

	mutex_lock(&tty_mutex);
	list_for_each(p, &tty_drivers)
		if (!l--)
			return list_entry(p, struct tty_driver, tty_drivers);
	return NULL;
}

static void *t_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct list_head *p = ((struct tty_driver *)v)->tty_drivers.next;
	(*pos)++;
	return p==&tty_drivers ? NULL :
			list_entry(p, struct tty_driver, tty_drivers);
}

static void t_stop(struct seq_file *m, void *v)
{
	mutex_unlock(&tty_mutex);
}

static struct seq_operations tty_drivers_op = {
	.start	= t_start,
	.next	= t_next,
	.stop	= t_stop,
	.show	= show_tty_driver
};

static int tty_drivers_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &tty_drivers_op);
}

static const struct file_operations proc_tty_drivers_operations = {
	.open		= tty_drivers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

/*
 * This is the handler for /proc/tty/ldiscs
 */
static int tty_ldiscs_read_proc(char *page, char **start, off_t off,
				int count, int *eof, void *data)
{
	int	i;
	int	len = 0;
	off_t	begin = 0;
	struct tty_ldisc *ld;
	
	for (i=0; i < NR_LDISCS; i++) {
		ld = tty_ldisc_get(i);
		if (ld == NULL)
			continue;
		len += sprintf(page+len, "%-10s %2d\n",
			       ld->name ? ld->name : "???", i);
		tty_ldisc_put(i);
		if (len+begin > off+count)
			break;
		if (len+begin < off) {
			begin += len;
			len = 0;
		}
	}
	if (i >= NR_LDISCS)
		*eof = 1;
	if (off >= len+begin)
		return 0;
	*start = page + (off-begin);
	return ((count < begin+len-off) ? count : begin+len-off);
}

/*
 * This function is called by tty_register_driver() to handle
 * registering the driver's /proc handler into /proc/tty/driver/<foo>
 */
void proc_tty_register_driver(struct tty_driver *driver)
{
	struct proc_dir_entry *ent;
		
	if ((!driver->read_proc && !driver->write_proc) ||
	    !driver->driver_name ||
	    driver->proc_entry)
		return;

	ent = create_proc_entry(driver->driver_name, 0, proc_tty_driver);
	if (!ent)
		return;
	ent->read_proc = driver->read_proc;
	ent->write_proc = driver->write_proc;
	ent->owner = driver->owner;
	ent->data = driver;

	driver->proc_entry = ent;
}

/*
 * This function is called by tty_unregister_driver()
 */
void proc_tty_unregister_driver(struct tty_driver *driver)
{
	struct proc_dir_entry *ent;

	ent = driver->proc_entry;
	if (!ent)
		return;
		
	remove_proc_entry(driver->driver_name, proc_tty_driver);
	
	driver->proc_entry = NULL;
}

/*
 * Called by proc_root_init() to initialize the /proc/tty subtree
 */
void __init proc_tty_init(void)
{
	struct proc_dir_entry *entry;
	if (!proc_mkdir("tty", NULL))
		return;
	proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
	/*
	 * /proc/tty/driver/serial reveals the exact character counts for
	 * serial links which is just too easy to abuse for inferring
	 * password lengths and inter-keystroke timings during password
	 * entry.
	 */
	proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR | S_IXUSR, NULL);

	create_proc_read_entry("tty/ldiscs", 0, NULL, tty_ldiscs_read_proc, NULL);
	entry = create_proc_entry("tty/drivers", 0, NULL);
	if (entry)
		entry->proc_fops = &proc_tty_drivers_operations;
}
Commit	Line	Data
1da177e4 LT	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
	18	static 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	*/
	24	static struct proc_dir_entry proc_tty_ldisc, proc_tty_driver;
	25
	26	/*
	27	* This is the handler for /proc/tty/drivers
	28	*/
	29	static 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
70	static 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 */
107	static void t_start(struct seq_file m, loff_t *pos)
108	{
109	struct list_head *p;
110	loff_t l = *pos;
ca509f69 AD	111
ca509f69 AD	112	mutex_lock(&tty_mutex);
1da177e4 LT	113	list_for_each(p, &tty_drivers)
	114	if (!l--)
	115	return list_entry(p, struct tty_driver, tty_drivers);
	116	return NULL;
	117	}
	118
	119	static void t_next(struct seq_file m, void v, loff_t pos)
	120	{
	121	struct list_head p = ((struct tty_driver )v)->tty_drivers.next;
	122	(*pos)++;
	123	return p==&tty_drivers ? NULL :
	124	list_entry(p, struct tty_driver, tty_drivers);
	125	}
	126
	127	static void t_stop(struct seq_file m, void v)
	128	{
ca509f69	129	mutex_unlock(&tty_mutex);
1da177e4 LT	130	}
	131
	132	static struct seq_operations tty_drivers_op = {
	133	.start = t_start,
	134	.next = t_next,
	135	.stop = t_stop,
	136	.show = show_tty_driver
	137	};
	138
	139	static int tty_drivers_open(struct inode inode, struct file file)
	140	{
	141	return seq_open(file, &tty_drivers_op);
	142	}
	143
00977a59	144	static const struct file_operations proc_tty_drivers_operations = {
1da177e4 LT	145	.open = tty_drivers_open,
	146	.read = seq_read,
	147	.llseek = seq_lseek,
	148	.release = seq_release,
	149	};
	150
	151	/*
	152	* This is the handler for /proc/tty/ldiscs
	153	*/
	154	static int tty_ldiscs_read_proc(char page, char *start, off_t off,
	155	int count, int eof, void data)
	156	{
	157	int i;
	158	int len = 0;
	159	off_t begin = 0;
	160	struct tty_ldisc *ld;
	161
	162	for (i=0; i < NR_LDISCS; i++) {
	163	ld = tty_ldisc_get(i);
	164	if (ld == NULL)
	165	continue;
	166	len += sprintf(page+len, "%-10s %2d\n",
	167	ld->name ? ld->name : "???", i);
	168	tty_ldisc_put(i);
	169	if (len+begin > off+count)
	170	break;
	171	if (len+begin < off) {
	172	begin += len;
	173	len = 0;
	174	}
	175	}
	176	if (i >= NR_LDISCS)
	177	*eof = 1;
	178	if (off >= len+begin)
	179	return 0;
	180	*start = page + (off-begin);
	181	return ((count < begin+len-off) ? count : begin+len-off);
	182	}
	183
	184	/*
	185	* This function is called by tty_register_driver() to handle
	186	* registering the driver's /proc handler into /proc/tty/driver/<foo>
	187	*/
	188	void proc_tty_register_driver(struct tty_driver *driver)
	189	{
	190	struct proc_dir_entry *ent;
	191
	192	if ((!driver->read_proc && !driver->write_proc) \|\|
	193	!driver->driver_name \|\|
	194	driver->proc_entry)
	195	return;
	196
	197	ent = create_proc_entry(driver->driver_name, 0, proc_tty_driver);
	198	if (!ent)
	199	return;
	200	ent->read_proc = driver->read_proc;
	201	ent->write_proc = driver->write_proc;
	202	ent->owner = driver->owner;
	203	ent->data = driver;
	204
	205	driver->proc_entry = ent;
	206	}
	207
	208	/*
209	* This function is called by tty_unregister_driver()
210	*/
211	void proc_tty_unregister_driver(struct tty_driver *driver)
212	{
213	struct proc_dir_entry *ent;
214
215	ent = driver->proc_entry;
216	if (!ent)
217	return;
218
219	remove_proc_entry(driver->driver_name, proc_tty_driver);
220
221	driver->proc_entry = NULL;
222	}
223
224	/*
225	* Called by proc_root_init() to initialize the /proc/tty subtree
226	*/
227	void __init proc_tty_init(void)
228	{
229	struct proc_dir_entry *entry;
230	if (!proc_mkdir("tty", NULL))
231	return;
232	proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
233	/*
234	* /proc/tty/driver/serial reveals the exact character counts for
235	* serial links which is just too easy to abuse for inferring
236	* password lengths and inter-keystroke timings during password
237	* entry.
238	*/
239	proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR \| S_IXUSR, NULL);
240
241	create_proc_read_entry("tty/ldiscs", 0, NULL, tty_ldiscs_read_proc, NULL);
242	entry = create_proc_entry("tty/drivers", 0, NULL);
243	if (entry)
244	entry->proc_fops = &proc_tty_drivers_operations;
245	}