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 @@
+/*
+ * 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;
+	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)
+{
+}
+
+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 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;
+}