diff options
Diffstat (limited to 'fs/proc/proc_tty.c')
| -rw-r--r-- | fs/proc/proc_tty.c | 242 |
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 0000000..15c4455 --- /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; +} |
