diff options
Diffstat (limited to 'drivers/char/pty.c')
| -rw-r--r-- | drivers/char/pty.c | 777 |
1 files changed, 0 insertions, 777 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c deleted file mode 100644 index 923a48585501..000000000000 --- a/drivers/char/pty.c +++ /dev/null @@ -1,777 +0,0 @@ -/* - * linux/drivers/char/pty.c - * - * Copyright (C) 1991, 1992 Linus Torvalds - * - * Added support for a Unix98-style ptmx device. - * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 - * - * When reading this code see also fs/devpts. In particular note that the - * driver_data field is used by the devpts side as a binding to the devpts - * inode. - */ - -#include <linux/module.h> - -#include <linux/errno.h> -#include <linux/interrupt.h> -#include <linux/tty.h> -#include <linux/tty_flip.h> -#include <linux/fcntl.h> -#include <linux/sched.h> -#include <linux/string.h> -#include <linux/major.h> -#include <linux/mm.h> -#include <linux/init.h> -#include <linux/smp_lock.h> -#include <linux/sysctl.h> -#include <linux/device.h> -#include <linux/uaccess.h> -#include <linux/bitops.h> -#include <linux/devpts_fs.h> -#include <linux/slab.h> - -#include <asm/system.h> - -#ifdef CONFIG_UNIX98_PTYS -static struct tty_driver *ptm_driver; -static struct tty_driver *pts_driver; -#endif - -static void pty_close(struct tty_struct *tty, struct file *filp) -{ - BUG_ON(!tty); - if (tty->driver->subtype == PTY_TYPE_MASTER) - WARN_ON(tty->count > 1); - else { - if (tty->count > 2) - return; - } - wake_up_interruptible(&tty->read_wait); - wake_up_interruptible(&tty->write_wait); - tty->packet = 0; - if (!tty->link) - return; - tty->link->packet = 0; - set_bit(TTY_OTHER_CLOSED, &tty->link->flags); - wake_up_interruptible(&tty->link->read_wait); - wake_up_interruptible(&tty->link->write_wait); - if (tty->driver->subtype == PTY_TYPE_MASTER) { - set_bit(TTY_OTHER_CLOSED, &tty->flags); -#ifdef CONFIG_UNIX98_PTYS - if (tty->driver == ptm_driver) - devpts_pty_kill(tty->link); -#endif - tty_unlock(); - tty_vhangup(tty->link); - tty_lock(); - } -} - -/* - * The unthrottle routine is called by the line discipline to signal - * that it can receive more characters. For PTY's, the TTY_THROTTLED - * flag is always set, to force the line discipline to always call the - * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE - * characters in the queue. This is necessary since each time this - * happens, we need to wake up any sleeping processes that could be - * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() - * for the pty buffer to be drained. - */ -static void pty_unthrottle(struct tty_struct *tty) -{ - tty_wakeup(tty->link); - set_bit(TTY_THROTTLED, &tty->flags); -} - -/** - * pty_space - report space left for writing - * @to: tty we are writing into - * - * The tty buffers allow 64K but we sneak a peak and clip at 8K this - * allows a lot of overspill room for echo and other fun messes to - * be handled properly - */ - -static int pty_space(struct tty_struct *to) -{ - int n = 8192 - to->buf.memory_used; - if (n < 0) - return 0; - return n; -} - -/** - * pty_write - write to a pty - * @tty: the tty we write from - * @buf: kernel buffer of data - * @count: bytes to write - * - * Our "hardware" write method. Data is coming from the ldisc which - * may be in a non sleeping state. We simply throw this at the other - * end of the link as if we were an IRQ handler receiving stuff for - * the other side of the pty/tty pair. - */ - -static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) -{ - struct tty_struct *to = tty->link; - - if (tty->stopped) - return 0; - - if (c > 0) { - /* Stuff the data into the input queue of the other end */ - c = tty_insert_flip_string(to, buf, c); - /* And shovel */ - if (c) { - tty_flip_buffer_push(to); - tty_wakeup(tty); - } - } - return c; -} - -/** - * pty_write_room - write space - * @tty: tty we are writing from - * - * Report how many bytes the ldisc can send into the queue for - * the other device. - */ - -static int pty_write_room(struct tty_struct *tty) -{ - if (tty->stopped) - return 0; - return pty_space(tty->link); -} - -/** - * pty_chars_in_buffer - characters currently in our tx queue - * @tty: our tty - * - * Report how much we have in the transmit queue. As everything is - * instantly at the other end this is easy to implement. - */ - -static int pty_chars_in_buffer(struct tty_struct *tty) -{ - return 0; -} - -/* Set the lock flag on a pty */ -static int pty_set_lock(struct tty_struct *tty, int __user *arg) -{ - int val; - if (get_user(val, arg)) - return -EFAULT; - if (val) - set_bit(TTY_PTY_LOCK, &tty->flags); - else - clear_bit(TTY_PTY_LOCK, &tty->flags); - return 0; -} - -/* Send a signal to the slave */ -static int pty_signal(struct tty_struct *tty, int sig) -{ - unsigned long flags; - struct pid *pgrp; - - if (tty->link) { - spin_lock_irqsave(&tty->link->ctrl_lock, flags); - pgrp = get_pid(tty->link->pgrp); - spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); - - kill_pgrp(pgrp, sig, 1); - put_pid(pgrp); - } - return 0; -} - -static void pty_flush_buffer(struct tty_struct *tty) -{ - struct tty_struct *to = tty->link; - unsigned long flags; - - if (!to) - return; - /* tty_buffer_flush(to); FIXME */ - if (to->packet) { - spin_lock_irqsave(&tty->ctrl_lock, flags); - tty->ctrl_status |= TIOCPKT_FLUSHWRITE; - wake_up_interruptible(&to->read_wait); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - } -} - -static int pty_open(struct tty_struct *tty, struct file *filp) -{ - int retval = -ENODEV; - - if (!tty || !tty->link) - goto out; - - retval = -EIO; - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) - goto out; - if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) - goto out; - if (tty->link->count != 1) - goto out; - - clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); - set_bit(TTY_THROTTLED, &tty->flags); - retval = 0; -out: - return retval; -} - -static void pty_set_termios(struct tty_struct *tty, - struct ktermios *old_termios) -{ - tty->termios->c_cflag &= ~(CSIZE | PARENB); - tty->termios->c_cflag |= (CS8 | CREAD); -} - -/** - * pty_do_resize - resize event - * @tty: tty being resized - * @ws: window size being set. - * - * Update the termios variables and send the necessary signals to - * peform a terminal resize correctly - */ - -int pty_resize(struct tty_struct *tty, struct winsize *ws) -{ - struct pid *pgrp, *rpgrp; - unsigned long flags; - struct tty_struct *pty = tty->link; - - /* For a PTY we need to lock the tty side */ - mutex_lock(&tty->termios_mutex); - if (!memcmp(ws, &tty->winsize, sizeof(*ws))) - goto done; - - /* Get the PID values and reference them so we can - avoid holding the tty ctrl lock while sending signals. - We need to lock these individually however. */ - - spin_lock_irqsave(&tty->ctrl_lock, flags); - pgrp = get_pid(tty->pgrp); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - - spin_lock_irqsave(&pty->ctrl_lock, flags); - rpgrp = get_pid(pty->pgrp); - spin_unlock_irqrestore(&pty->ctrl_lock, flags); - - if (pgrp) - kill_pgrp(pgrp, SIGWINCH, 1); - if (rpgrp != pgrp && rpgrp) - kill_pgrp(rpgrp, SIGWINCH, 1); - - put_pid(pgrp); - put_pid(rpgrp); - - tty->winsize = *ws; - pty->winsize = *ws; /* Never used so will go away soon */ -done: - mutex_unlock(&tty->termios_mutex); - return 0; -} - -/* Traditional BSD devices */ -#ifdef CONFIG_LEGACY_PTYS - -static int pty_install(struct tty_driver *driver, struct tty_struct *tty) -{ - struct tty_struct *o_tty; - int idx = tty->index; - int retval; - - o_tty = alloc_tty_struct(); - if (!o_tty) - return -ENOMEM; - if (!try_module_get(driver->other->owner)) { - /* This cannot in fact currently happen */ - free_tty_struct(o_tty); - return -ENOMEM; - } - initialize_tty_struct(o_tty, driver->other, idx); - - /* We always use new tty termios data so we can do this - the easy way .. */ - retval = tty_init_termios(tty); - if (retval) - goto free_mem_out; - - retval = tty_init_termios(o_tty); - if (retval) { - tty_free_termios(tty); - goto free_mem_out; - } - - /* - * Everything allocated ... set up the o_tty structure. - */ - driver->other->ttys[idx] = o_tty; - tty_driver_kref_get(driver->other); - if (driver->subtype == PTY_TYPE_MASTER) - o_tty->count++; - /* Establish the links in both directions */ - tty->link = o_tty; - o_tty->link = tty; - - tty_driver_kref_get(driver); - tty->count++; - driver->ttys[idx] = tty; - return 0; -free_mem_out: - module_put(o_tty->driver->owner); - free_tty_struct(o_tty); - return -ENOMEM; -} - -static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) -{ - switch (cmd) { - case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ - return pty_set_lock(tty, (int __user *) arg); - case TIOCSIG: /* Send signal to other side of pty */ - return pty_signal(tty, (int) arg); - } - return -ENOIOCTLCMD; -} - -static int legacy_count = CONFIG_LEGACY_PTY_COUNT; -module_param(legacy_count, int, 0); - -/* - * The master side of a pty can do TIOCSPTLCK and thus - * has pty_bsd_ioctl. - */ -static const struct tty_operations master_pty_ops_bsd = { - .install = pty_install, - .open = pty_open, - .close = pty_close, - .write = pty_write, - .write_room = pty_write_room, - .flush_buffer = pty_flush_buffer, - .chars_in_buffer = pty_chars_in_buffer, - .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, - .ioctl = pty_bsd_ioctl, - .resize = pty_resize -}; - -static const struct tty_operations slave_pty_ops_bsd = { - .install = pty_install, - .open = pty_open, - .close = pty_close, - .write = pty_write, - .write_room = pty_write_room, - .flush_buffer = pty_flush_buffer, - .chars_in_buffer = pty_chars_in_buffer, - .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, - .resize = pty_resize -}; - -static void __init legacy_pty_init(void) -{ - struct tty_driver *pty_driver, *pty_slave_driver; - - if (legacy_count <= 0) - return; - - pty_driver = alloc_tty_driver(legacy_count); - if (!pty_driver) - panic("Couldn't allocate pty driver"); - - pty_slave_driver = alloc_tty_driver(legacy_count); - if (!pty_slave_driver) - panic("Couldn't allocate pty slave driver"); - - pty_driver->owner = THIS_MODULE; - pty_driver->driver_name = "pty_master"; - pty_driver->name = "pty"; - pty_driver->major = PTY_MASTER_MAJOR; - pty_driver->minor_start = 0; - pty_driver->type = TTY_DRIVER_TYPE_PTY; - pty_driver->subtype = PTY_TYPE_MASTER; - pty_driver->init_termios = tty_std_termios; - pty_driver->init_termios.c_iflag = 0; - pty_driver->init_termios.c_oflag = 0; - pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; - pty_driver->init_termios.c_lflag = 0; - pty_driver->init_termios.c_ispeed = 38400; - pty_driver->init_termios.c_ospeed = 38400; - pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; - pty_driver->other = pty_slave_driver; - tty_set_operations(pty_driver, &master_pty_ops_bsd); - - pty_slave_driver->owner = THIS_MODULE; - pty_slave_driver->driver_name = "pty_slave"; - pty_slave_driver->name = "ttyp"; - pty_slave_driver->major = PTY_SLAVE_MAJOR; - pty_slave_driver->minor_start = 0; - pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; - pty_slave_driver->subtype = PTY_TYPE_SLAVE; - pty_slave_driver->init_termios = tty_std_termios; - pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; - pty_slave_driver->init_termios.c_ispeed = 38400; - pty_slave_driver->init_termios.c_ospeed = 38400; - pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | - TTY_DRIVER_REAL_RAW; - pty_slave_driver->other = pty_driver; - tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); - - if (tty_register_driver(pty_driver)) - panic("Couldn't register pty driver"); - if (tty_register_driver(pty_slave_driver)) - panic("Couldn't register pty slave driver"); -} -#else -static inline void legacy_pty_init(void) { } -#endif - -/* Unix98 devices */ -#ifdef CONFIG_UNIX98_PTYS -/* - * sysctl support for setting limits on the number of Unix98 ptys allocated. - * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. - */ -int pty_limit = NR_UNIX98_PTY_DEFAULT; -static int pty_limit_min; -static int pty_limit_max = NR_UNIX98_PTY_MAX; -static int pty_count; - -static struct cdev ptmx_cdev; - -static struct ctl_table pty_table[] = { - { - .procname = "max", - .maxlen = sizeof(int), - .mode = 0644, - .data = &pty_limit, - .proc_handler = proc_dointvec_minmax, - .extra1 = &pty_limit_min, - .extra2 = &pty_limit_max, - }, { - .procname = "nr", - .maxlen = sizeof(int), - .mode = 0444, - .data = &pty_count, - .proc_handler = proc_dointvec, - }, - {} -}; - -static struct ctl_table pty_kern_table[] = { - { - .procname = "pty", - .mode = 0555, - .child = pty_table, - }, - {} -}; - -static struct ctl_table pty_root_table[] = { - { - .procname = "kernel", - .mode = 0555, - .child = pty_kern_table, - }, - {} -}; - - -static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, - unsigned int cmd, unsigned long arg) -{ - switch (cmd) { - case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ - return pty_set_lock(tty, (int __user *)arg); - case TIOCGPTN: /* Get PT Number */ - return put_user(tty->index, (unsigned int __user *)arg); - case TIOCSIG: /* Send signal to other side of pty */ - return pty_signal(tty, (int) arg); - } - - return -ENOIOCTLCMD; -} - -/** - * ptm_unix98_lookup - find a pty master - * @driver: ptm driver - * @idx: tty index - * - * Look up a pty master device. Called under the tty_mutex for now. - * This provides our locking. - */ - -static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, - struct inode *ptm_inode, int idx) -{ - struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); - if (tty) - tty = tty->link; - return tty; -} - -/** - * pts_unix98_lookup - find a pty slave - * @driver: pts driver - * @idx: tty index - * - * Look up a pty master device. Called under the tty_mutex for now. - * This provides our locking. - */ - -static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, - struct inode *pts_inode, int idx) -{ - struct tty_struct *tty = devpts_get_tty(pts_inode, idx); - /* Master must be open before slave */ - if (!tty) - return ERR_PTR(-EIO); - return tty; -} - -static void pty_unix98_shutdown(struct tty_struct *tty) -{ - /* We have our own method as we don't use the tty index */ - kfree(tty->termios); -} - -/* We have no need to install and remove our tty objects as devpts does all - the work for us */ - -static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) -{ - struct tty_struct *o_tty; - int idx = tty->index; - - o_tty = alloc_tty_struct(); - if (!o_tty) - return -ENOMEM; - if (!try_module_get(driver->other->owner)) { - /* This cannot in fact currently happen */ - free_tty_struct(o_tty); - return -ENOMEM; - } - initialize_tty_struct(o_tty, driver->other, idx); - - tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); - if (tty->termios == NULL) - goto free_mem_out; - *tty->termios = driver->init_termios; - tty->termios_locked = tty->termios + 1; - - o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); - if (o_tty->termios == NULL) - goto free_mem_out; - *o_tty->termios = driver->other->init_termios; - o_tty->termios_locked = o_tty->termios + 1; - - tty_driver_kref_get(driver->other); - if (driver->subtype == PTY_TYPE_MASTER) - o_tty->count++; - /* Establish the links in both directions */ - tty->link = o_tty; - o_tty->link = tty; - /* - * All structures have been allocated, so now we install them. - * Failures after this point use release_tty to clean up, so - * there's no need to null out the local pointers. - */ - tty_driver_kref_get(driver); - tty->count++; - pty_count++; - return 0; -free_mem_out: - kfree(o_tty->termios); - module_put(o_tty->driver->owner); - free_tty_struct(o_tty); - kfree(tty->termios); - return -ENOMEM; -} - -static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) -{ - pty_count--; -} - -static const struct tty_operations ptm_unix98_ops = { - .lookup = ptm_unix98_lookup, - .install = pty_unix98_install, - .remove = pty_unix98_remove, - .open = pty_open, - .close = pty_close, - .write = pty_write, - .write_room = pty_write_room, - .flush_buffer = pty_flush_buffer, - .chars_in_buffer = pty_chars_in_buffer, - .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, - .ioctl = pty_unix98_ioctl, - .shutdown = pty_unix98_shutdown, - .resize = pty_resize -}; - -static const struct tty_operations pty_unix98_ops = { - .lookup = pts_unix98_lookup, - .install = pty_unix98_install, - .remove = pty_unix98_remove, - .open = pty_open, - .close = pty_close, - .write = pty_write, - .write_room = pty_write_room, - .flush_buffer = pty_flush_buffer, - .chars_in_buffer = pty_chars_in_buffer, - .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, - .shutdown = pty_unix98_shutdown -}; - -/** - * ptmx_open - open a unix 98 pty master - * @inode: inode of device file - * @filp: file pointer to tty - * - * Allocate a unix98 pty master device from the ptmx driver. - * - * Locking: tty_mutex protects the init_dev work. tty->count should - * protect the rest. - * allocated_ptys_lock handles the list of free pty numbers - */ - -static int ptmx_open(struct inode *inode, struct file *filp) -{ - struct tty_struct *tty; - int retval; - int index; - - nonseekable_open(inode, filp); - - /* find a device that is not in use. */ - tty_lock(); - index = devpts_new_index(inode); - tty_unlock(); - if (index < 0) - return index; - - mutex_lock(&tty_mutex); - tty_lock(); - tty = tty_init_dev(ptm_driver, index, 1); - mutex_unlock(&tty_mutex); - - if (IS_ERR(tty)) { - retval = PTR_ERR(tty); - goto out; - } - - set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ - - retval = tty_add_file(tty, filp); - if (retval) - goto out; - - retval = devpts_pty_new(inode, tty->link); - if (retval) - goto out1; - - retval = ptm_driver->ops->open(tty, filp); - if (retval) - goto out2; -out1: - tty_unlock(); - return retval; -out2: - tty_unlock(); - tty_release(inode, filp); - return retval; -out: - devpts_kill_index(inode, index); - tty_unlock(); - return retval; -} - -static struct file_operations ptmx_fops; - -static void __init unix98_pty_init(void) -{ - ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); - if (!ptm_driver) - panic("Couldn't allocate Unix98 ptm driver"); - pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); - if (!pts_driver) - panic("Couldn't allocate Unix98 pts driver"); - - ptm_driver->owner = THIS_MODULE; - ptm_driver->driver_name = "pty_master"; - ptm_driver->name = "ptm"; - ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; - ptm_driver->minor_start = 0; - ptm_driver->type = TTY_DRIVER_TYPE_PTY; - ptm_driver->subtype = PTY_TYPE_MASTER; - ptm_driver->init_termios = tty_std_termios; - ptm_driver->init_termios.c_iflag = 0; - ptm_driver->init_termios.c_oflag = 0; - ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; - ptm_driver->init_termios.c_lflag = 0; - ptm_driver->init_termios.c_ispeed = 38400; - ptm_driver->init_termios.c_ospeed = 38400; - ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | - TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; - ptm_driver->other = pts_driver; - tty_set_operations(ptm_driver, &ptm_unix98_ops); - - pts_driver->owner = THIS_MODULE; - pts_driver->driver_name = "pty_slave"; - pts_driver->name = "pts"; - pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; - pts_driver->minor_start = 0; - pts_driver->type = TTY_DRIVER_TYPE_PTY; - pts_driver->subtype = PTY_TYPE_SLAVE; - pts_driver->init_termios = tty_std_termios; - pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; - pts_driver->init_termios.c_ispeed = 38400; - pts_driver->init_termios.c_ospeed = 38400; - pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | - TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; - pts_driver->other = ptm_driver; - tty_set_operations(pts_driver, &pty_unix98_ops); - - if (tty_register_driver(ptm_driver)) - panic("Couldn't register Unix98 ptm driver"); - if (tty_register_driver(pts_driver)) - panic("Couldn't register Unix98 pts driver"); - - register_sysctl_table(pty_root_table); - - /* Now create the /dev/ptmx special device */ - tty_default_fops(&ptmx_fops); - ptmx_fops.open = ptmx_open; - - cdev_init(&ptmx_cdev, &ptmx_fops); - if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || - register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) - panic("Couldn't register /dev/ptmx driver\n"); - device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); -} - -#else -static inline void unix98_pty_init(void) { } -#endif - -static int __init pty_init(void) -{ - legacy_pty_init(); - unix98_pty_init(); - return 0; -} -module_init(pty_init); |