/* * linux/drivers/char/tty_io.c * * Copyright (C) 1991, 1992 Linus Torvalds */ /* * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles * or rs-channels. It also implements echoing, cooked mode etc. * * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. * * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the * tty_struct and tty_queue structures. Previously there was a array * of 256 tty_struct's which was statically allocated, and the * tty_queue structures were allocated at boot time. Both are now * dynamically allocated only when the tty is open. * * Also restructured routines so that there is more of a separation * between the high-level tty routines (tty_io.c and tty_ioctl.c) and * the low-level tty routines (serial.c, pty.c, console.c). This * makes for cleaner and more compact code. -TYT, 9/17/92 * * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines * which can be dynamically activated and de-activated by the line * discipline handling modules (like SLIP). * * NOTE: pay no attention to the line discipline code (yet); its * interface is still subject to change in this version... * -- TYT, 1/31/92 * * Added functionality to the OPOST tty handling. No delays, but all * other bits should be there. * -- Nick Holloway , 27th May 1993. * * Rewrote canonical mode and added more termios flags. * -- [e-mail] (J. Cowley), 13Jan94 * * Reorganized FASYNC support so mouse code can share it. * -- [e-mail], 9Sep95 * * New TIOCLINUX variants added. * -- [e-mail], 19-Nov-95 * * Restrict vt switching via ioctl() * -- [e-mail], 5-Dec-95 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kbd_kern.h" #include "vt_kern.h" #include "selection.h" #ifdef CONFIG_KERNELD #include #endif #define CONSOLE_DEV MKDEV(TTY_MAJOR,0) #define TTY_DEV MKDEV(TTYAUX_MAJOR,0) #undef TTY_DEBUG_HANGUP #define TTY_PARANOIA_CHECK #define CHECK_TTY_COUNT extern void do_blank_screen(int nopowersave); extern void set_vesa_blanking(const unsigned long arg); struct termios tty_std_termios; /* for the benefit of tty drivers */ struct tty_driver *tty_drivers = NULL; /* linked list of tty drivers */ struct tty_ldisc ldiscs[NR_LDISCS]; /* line disc dispatch table */ /* * fg_console is the current virtual console, * last_console is the last used one, * want_console is the console we want to switch to, * kmsg_redirect is the console for kernel messages, * redirect is the pseudo-tty that console output * is redirected to if asked by TIOCCONS. */ int fg_console = 0; int last_console = 0; int want_console = -1; int kmsg_redirect = 0; struct tty_struct * redirect = NULL; struct wait_queue * keypress_wait = NULL; char vt_dont_switch = 0; static void initialize_tty_struct(struct tty_struct *tty); static int tty_read(struct inode *, struct file *, char *, int); static int tty_write(struct inode *, struct file *, const char *, int); static int tty_select(struct inode *, struct file *, int, select_table *); static int tty_open(struct inode *, struct file *); static void tty_release(struct inode *, struct file *); static int tty_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg); static int tty_fasync(struct inode * inode, struct file * filp, int on); extern void reset_palette(int currcons) ; extern void set_palette(void) ; #ifndef MIN #define MIN(a,b) ((a) < (b) ? (a) : (b)) #endif /* * These two routines return the name of tty. tty_name() should NOT * be used in interrupt drivers, since it's not re-entrant. Use * _tty_name() instead. */ char *_tty_name(struct tty_struct *tty, char *buf) { if (tty) sprintf(buf, "%s%d", tty->driver.name, MINOR(tty->device) - tty->driver.minor_start + tty->driver.name_base); else strcpy(buf, "NULL tty"); return buf; } char *tty_name(struct tty_struct *tty) { static char buf[64]; return(_tty_name(tty, buf)); } inline int tty_paranoia_check(struct tty_struct *tty, kdev_t device, const char *routine) { #ifdef TTY_PARANOIA_CHECK static const char *badmagic = "Warning: bad magic number for tty struct (%s) in %s\n"; static const char *badtty = "Warning: null TTY for (%s) in %s\n"; if (!tty) { printk(badtty, kdevname(device), routine); return 1; } if (tty->magic != TTY_MAGIC) { printk(badmagic, kdevname(device), routine); return 1; } #endif return 0; } static int check_tty_count(struct tty_struct *tty, const char *routine) { #ifdef CHECK_TTY_COUNT struct file *f; int i, count = 0; for (f = first_file, i=0; if_next) { if (!f->f_count) continue; if (f->private_data == tty) { count++; } } if (tty->driver.type == TTY_DRIVER_TYPE_PTY && tty->driver.subtype == PTY_TYPE_SLAVE && tty->link && tty->link->count) count++; if (tty->count != count) { printk("Warning: dev (%s) tty->count(%d) != #fd's(%d) in %s\n", kdevname(tty->device), tty->count, count, routine); return count; } #endif return 0; } int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) { if (disc < N_TTY || disc >= NR_LDISCS) return -EINVAL; if (new_ldisc) { ldiscs[disc] = *new_ldisc; ldiscs[disc].flags |= LDISC_FLAG_DEFINED; ldiscs[disc].num = disc; } else memset(&ldiscs[disc], 0, sizeof(struct tty_ldisc)); return 0; } /* Set the discipline of a tty line. */ static int tty_set_ldisc(struct tty_struct *tty, int ldisc) { int retval = 0; struct tty_ldisc o_ldisc; if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) return -EINVAL; #ifdef CONFIG_KERNELD /* Eduardo Blanco */ if (!(ldiscs[ldisc].flags & LDISC_FLAG_DEFINED)) { char modname [20]; sprintf(modname, "tty-ldisc-%d", ldisc); request_module (modname); } #endif if (!(ldiscs[ldisc].flags & LDISC_FLAG_DEFINED)) return -EINVAL; if (tty->ldisc.num == ldisc) return 0; /* We are already in the desired discipline */ o_ldisc = tty->ldisc; tty_wait_until_sent(tty, 0); /* Shutdown the current discipline. */ if (tty->ldisc.close) (tty->ldisc.close)(tty); /* Now set up the new line discipline. */ tty->ldisc = ldiscs[ldisc]; tty->termios->c_line = ldisc; if (tty->ldisc.open) retval = (tty->ldisc.open)(tty); if (retval < 0) { tty->ldisc = o_ldisc; tty->termios->c_line = tty->ldisc.num; if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { tty->ldisc = ldiscs[N_TTY]; tty->termios->c_line = N_TTY; if (tty->ldisc.open) { int r = tty->ldisc.open(tty); if (r < 0) panic("Couldn't open N_TTY ldisc for " "%s --- error %d.", tty_name(tty), r); } } } if (tty->ldisc.num != o_ldisc.num && tty->driver.set_ldisc) tty->driver.set_ldisc(tty); return retval; } /* * This routine returns a tty driver structure, given a device number */ struct tty_driver *get_tty_driver(kdev_t device) { int major, minor; struct tty_driver *p; minor = MINOR(device); major = MAJOR(device); for (p = tty_drivers; p; p = p->next) { if (p->major != major) continue; if (minor < p->minor_start) continue; if (minor >= p->minor_start + p->num) continue; return p; } return NULL; } /* * If we try to write to, or set the state of, a terminal and we're * not in the foreground, send a SIGTTOU. If the signal is blocked or * ignored, go ahead and perform the operation. (POSIX 7.2) */ int tty_check_change(struct tty_struct * tty) { if (current->tty != tty) return 0; if (tty->pgrp pgrp == tty->pgrp) return 0; if (is_ignored(SIGTTOU)) return 0; if (is_orphaned_pgrp(current->pgrp)) return -EIO; (void) kill_pg(current->pgrp,SIGTTOU,1); return -ERESTARTSYS; } static int hung_up_tty_read(struct inode * inode, struct file * file, char * buf, int count) { return 0; } static int hung_up_tty_write(struct inode * inode, struct file * file, const char * buf, int count) { return -EIO; } static int hung_up_tty_select(struct inode * inode, struct file * filp, int sel_type, select_table * wait) { return 1; } static int hung_up_tty_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg) { return cmd == TIOCSPGRP ? -ENOTTY : -EIO; } static int tty_lseek(struct inode * inode, struct file * file, off_t offset, int orig) { return -ESPIPE; } static struct file_operations tty_fops = { tty_lseek, tty_read, tty_write, NULL, /* tty_readdir */ tty_select, tty_ioctl, NULL, /* tty_mmap */ tty_open, tty_release, NULL, /* tty_fsync */ tty_fasync }; static struct file_operations hung_up_tty_fops = { tty_lseek, hung_up_tty_read, hung_up_tty_write, NULL, /* hung_up_tty_readdir */ hung_up_tty_select, hung_up_tty_ioctl, NULL, /* hung_up_tty_mmap */ NULL, /* hung_up_tty_open */ tty_release, /* hung_up_tty_release */ NULL, /* hung_up_tty_fsync */ NULL /* hung_up_tty_fasync */ }; void do_tty_hangup(struct tty_struct * tty, struct file_operations *fops) { int i; struct file * filp; struct task_struct *p; if (!tty) return; check_tty_count(tty, "do_tty_hangup"); for (filp = first_file, i=0; if_next) { if (!filp->f_count) continue; if (filp->private_data != tty) continue; if (filp->f_inode && filp->f_inode->i_rdev == CONSOLE_DEV) continue; if (filp->f_op != &tty_fops) continue; tty_fasync(filp->f_inode, filp, 0); filp->f_op = fops; } if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty); if (tty->driver.flush_buffer) tty->driver.flush_buffer(tty); if ((tty->flags & (1 ldisc.write_wakeup) (tty->ldisc.write_wakeup)(tty); wake_up_interruptible(&tty->write_wait); wake_up_interruptible(&tty->read_wait); /* * Shutdown the current line discipline, and reset it to * N_TTY. */ if (tty->ldisc.num != ldiscs[N_TTY].num) { if (tty->ldisc.close) (tty->ldisc.close)(tty); tty->ldisc = ldiscs[N_TTY]; tty->termios->c_line = N_TTY; if (tty->ldisc.open) { i = (tty->ldisc.open)(tty); if (i < 0) printk("do_tty_hangup: N_TTY open: error %d\n", -i); } } for_each_task(p) { if ((tty->session > 0) && (p->session == tty->session) && p->leader) { send_sig(SIGHUP,p,1); send_sig(SIGCONT,p,1); if (tty->pgrp > 0) p->tty_old_pgrp = tty->pgrp; } if (p->tty == tty) p->tty = NULL; } tty->flags = 0; tty->session = 0; tty->pgrp = -1; tty->ctrl_status = 0; if (tty->driver.flags & TTY_DRIVER_RESET_TERMIOS) *tty->termios = tty->driver.init_termios; if (tty->driver.hangup) (tty->driver.hangup)(tty); } void tty_hangup(struct tty_struct * tty) { #ifdef TTY_DEBUG_HANGUP printk("%s hangup...\n", tty_name(tty)); #endif do_tty_hangup(tty, &hung_up_tty_fops); } void tty_vhangup(struct tty_struct * tty) { #ifdef TTY_DEBUG_HANGUP printk("%s vhangup...\n", tty_name(tty)); #endif do_tty_hangup(tty, &hung_up_tty_fops); } int tty_hung_up_p(struct file * filp) { return (filp->f_op == &hung_up_tty_fops); } /* * This function is typically called only by the session leader, when * it wants to disassociate itself from its controlling tty. * * It performs the following functions: * (1) Sends a SIGHUP and SIGCONT to the foreground process group * (2) Clears the tty from being controlling the session * (3) Clears the controlling tty for all processes in the * session group. * * The argument on_exit is set to 1 if called when a process is * exiting; it is 0 if called by the ioctl TIOCNOTTY. */ void disassociate_ctty(int on_exit) { struct tty_struct *tty = current->tty; struct task_struct *p; int tty_pgrp = -1; if (tty) { tty_pgrp = tty->pgrp; if (on_exit && tty->driver.type != TTY_DRIVER_TYPE_PTY) tty_vhangup(tty); } else { if (current->tty_old_pgrp) { kill_pg(current->tty_old_pgrp, SIGHUP, on_exit); kill_pg(current->tty_old_pgrp, SIGCONT, on_exit); } return; } if (tty_pgrp > 0) { kill_pg(tty_pgrp, SIGHUP, on_exit); if (!on_exit) kill_pg(tty_pgrp, SIGCONT, on_exit); } current->tty_old_pgrp = 0; tty->session = 0; tty->pgrp = -1; for_each_task(p) if (p->session == current->session) p->tty = NULL; } /* * Sometimes we want to wait until a particular VT has been activated. We * do it in a very simple manner. Everybody waits on a single queue and * get woken up at once. Those that are satisfied go on with their business, * while those not ready go back to sleep. Seems overkill to add a wait * to each vt just for this - usually this does nothing! */ static struct wait_queue *vt_activate_queue = NULL; /* * Sleeps until a vt is activated, or the task is interrupted. Returns * 0 if activation, -1 if interrupted. */ int vt_waitactive(void) { interruptible_sleep_on(&vt_activate_queue); return (current->signal & ~current->blocked) ? -1 : 0; } #define vt_wake_waitactive() wake_up(&vt_activate_queue) void reset_vc(unsigned int new_console) { vt_cons[new_console]->vc_mode = KD_TEXT; kbd_table[new_console].kbdmode = VC_XLATE; vt_cons[new_console]->vt_mode.mode = VT_AUTO; vt_cons[new_console]->vt_mode.waitv = 0; vt_cons[new_console]->vt_mode.relsig = 0; vt_cons[new_console]->vt_mode.acqsig = 0; vt_cons[new_console]->vt_mode.frsig = 0; vt_cons[new_console]->vt_pid = -1; vt_cons[new_console]->vt_newvt = -1; reset_palette (new_console) ; } /* * Performs the back end of a vt switch */ void complete_change_console(unsigned int new_console) { unsigned char old_vc_mode; if ((new_console == fg_console) || (vt_dont_switch)) return; if (!vc_cons_allocated(new_console)) return; last_console = fg_console; /* * If we're switching, we could be going from KD_GRAPHICS to * KD_TEXT mode or vice versa, which means we need to blank or * unblank the screen later. */ old_vc_mode = vt_cons[fg_console]->vc_mode; update_screen(new_console); /* * If this new console is under process control, send it a signal * telling it that it has acquired. Also check if it has died and * clean up (similar to logic employed in change_console()) */ if (vt_cons[new_console]->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_proc() will * tell us if the process has gone or something else * is awry */ if (kill_proc(vt_cons[new_console]->vt_pid, vt_cons[new_console]->vt_mode.acqsig, 1) != 0) { /* * The controlling process has died, so we revert back to * normal operation. In this case, we'll also change back * to KD_TEXT mode. I'm not sure if this is strictly correct * but it saves the agony when the X server dies and the screen * remains blanked due to KD_GRAPHICS! It would be nice to do * this outside of VT_PROCESS but there is no single process * to account for and tracking tty count may be undesirable. */ reset_vc(new_console); } } /* * We do this here because the controlling process above may have * gone, and so there is now a new vc_mode */ if (old_vc_mode != vt_cons[new_console]->vc_mode) { if (vt_cons[new_console]->vc_mode == KD_TEXT) do_unblank_screen(); else do_blank_screen(1); } /* Set the colour palette for this VT */ if (vt_cons[new_console]->vc_mode == KD_TEXT) set_palette() ; /* * Wake anyone waiting for their VT to activate */ vt_wake_waitactive(); return; } /* * Performs the front-end of a vt switch */ void change_console(unsigned int new_console) { if ((new_console == fg_console) || (vt_dont_switch)) return; if (!vc_cons_allocated(new_console)) return; /* * If this vt is in process mode, then we need to handshake with * that process before switching. Essentially, we store where that * vt wants to switch to and wait for it to tell us when it's done * (via VT_RELDISP ioctl). * * We also check to see if the controlling process still exists. * If it doesn't, we reset this vt to auto mode and continue. * This is a cheap way to track process control. The worst thing * that can happen is: we send a signal to a process, it dies, and * the switch gets "lost" waiting for a response; hopefully, the * user will try again, we'll detect the process is gone (unless * the user waits just the right amount of time :-) and revert the * vt to auto control. */ if (vt_cons[fg_console]->vt_mode.mode == VT_PROCESS) { /* * Send the signal as privileged - kill_proc() will * tell us if the process has gone or something else * is awry */ if (kill_proc(vt_cons[fg_console]->vt_pid, vt_cons[fg_console]->vt_mode.relsig, 1) == 0) { /* * It worked. Mark the vt to switch to and * return. The process needs to send us a * VT_RELDISP ioctl to complete the switch. */ vt_cons[fg_console]->vt_newvt = new_console; return; } /* * The controlling process has died, so we revert back to * normal operation. In this case, we'll also change back * to KD_TEXT mode. I'm not sure if this is strictly correct * but it saves the agony when the X server dies and the screen * remains blanked due to KD_GRAPHICS! It would be nice to do * this outside of VT_PROCESS but there is no single process * to account for and tracking tty count may be undesirable. */ reset_vc(fg_console); /* * Fall through to normal (VT_AUTO) handling of the switch... */ } /* * Ignore all switches in KD_GRAPHICS+VT_AUTO mode */ if (vt_cons[fg_console]->vc_mode == KD_GRAPHICS) return; complete_change_console(new_console); } void wait_for_keypress(void) { sleep_on(&keypress_wait); } void stop_tty(struct tty_struct *tty) { if (tty->stopped) return; tty->stopped = 1; if (tty->link && tty->link->packet) { tty->ctrl_status &= ~TIOCPKT_START; tty->ctrl_status |= TIOCPKT_STOP; wake_up_interruptible(&tty->link->read_wait); } if (tty->driver.stop) (tty->driver.stop)(tty); } void start_tty(struct tty_struct *tty) { if (!tty->stopped) return; tty->stopped = 0; if (tty->link && tty->link->packet) { tty->ctrl_status &= ~TIOCPKT_STOP; tty->ctrl_status |= TIOCPKT_START; wake_up_interruptible(&tty->link->read_wait); } if (tty->driver.start) (tty->driver.start)(tty); if ((tty->flags & (1 ldisc.write_wakeup) (tty->ldisc.write_wakeup)(tty); wake_up_interruptible(&tty->write_wait); } static int tty_read(struct inode * inode, struct file * file, char * buf, int count) { int i; struct tty_struct * tty; tty = (struct tty_struct *)file->private_data; if (tty_paranoia_check(tty, inode->i_rdev, "tty_read")) return -EIO; if (!tty || (tty->flags & (1 pgrp > 0) && (current->tty == tty) && (tty->pgrp != current->pgrp)) if (is_ignored(SIGTTIN) || is_orphaned_pgrp(current->pgrp)) return -EIO; else { (void) kill_pg(current->pgrp, SIGTTIN, 1); return -ERESTARTSYS; } #endif if (tty->ldisc.read) /* XXX casts are for what kernel-wide prototypes should be. */ i = (tty->ldisc.read)(tty,file,(unsigned char *)buf,(unsigned int)count); else i = -EIO; if (i > 0) inode->i_atime = CURRENT_TIME; return i; } /* * Split writes up in sane blocksizes to avoid * denial-of-service type attacks */ static inline int do_tty_write( int (*write)(struct tty_struct *, struct file *, const unsigned char *, unsigned int), struct inode *inode, struct tty_struct *tty, struct file *file, const unsigned char *buf, unsigned int count) { int ret = 0, written = 0; for (;;) { unsigned int size = PAGE_SIZE*2; if (size > count) size = count; ret = write(tty, file, buf, size); if (ret signal & ~current->blocked) break; if (need_resched) schedule(); } if (written) { inode->i_mtime = CURRENT_TIME; ret = written; } return ret; } static int tty_write(struct inode * inode, struct file * file, const char * buf, int count) { int is_console; struct tty_struct * tty; is_console = (inode->i_rdev == CONSOLE_DEV); if (is_console && redirect) tty = redirect; else tty = (struct tty_struct *)file->private_data; if (tty_paranoia_check(tty, inode->i_rdev, "tty_write")) return -EIO; if (!tty || !tty->driver.write || (tty->flags & (1 pgrp > 0) && (current->tty == tty) && (tty->pgrp != current->pgrp)) { if (is_orphaned_pgrp(current->pgrp)) return -EIO; if (!is_ignored(SIGTTOU)) { (void) kill_pg(current->pgrp, SIGTTOU, 1); return -ERESTARTSYS; } } #endif if (!tty->ldisc.write) return -EIO; return do_tty_write(tty->ldisc.write, inode, tty, file, (const unsigned char *)buf, (unsigned int)count); } /* * This is so ripe with races that you should *really* not touch this * unless you know exactly what you are doing. All the changes have to be * made atomically, or there may be incorrect pointers all over the place. */ static int init_dev(kdev_t device, struct tty_struct **ret_tty) { struct tty_struct *tty, **tty_loc, *o_tty, **o_tty_loc; struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; struct tty_driver *driver; int retval; int idx; driver = get_tty_driver(device); if (!driver) return -ENODEV; idx = MINOR(device) - driver->minor_start; tty = o_tty = NULL; tp = o_tp = NULL; ltp = o_ltp = NULL; o_tty_loc = NULL; o_tp_loc = o_ltp_loc = NULL; tty_loc = &driver->table[idx]; tp_loc = &driver->termios[idx]; ltp_loc = &driver->termios_locked[idx]; repeat: retval = -EIO; if (driver->type == TTY_DRIVER_TYPE_PTY && driver->subtype == PTY_TYPE_MASTER && *tty_loc && (*tty_loc)->count) goto end_init; retval = -ENOMEM; if (!*tty_loc && !tty) { if (!(tty = (struct tty_struct*) get_free_page(GFP_KERNEL))) goto end_init; initialize_tty_struct(tty); tty->device = device; tty->driver = *driver; goto repeat; } if (!*tp_loc && !tp) { tp = (struct termios *) kmalloc(sizeof(struct termios), GFP_KERNEL); if (!tp) goto end_init; *tp = driver->init_termios; goto repeat; } if (!*ltp_loc && !ltp) { ltp = (struct termios *) kmalloc(sizeof(struct termios), GFP_KERNEL); if (!ltp) goto end_init; memset(ltp, 0, sizeof(struct termios)); goto repeat; } if (driver->type == TTY_DRIVER_TYPE_PTY) { o_tty_loc = &driver->other->table[idx]; o_tp_loc = &driver->other->termios[idx]; o_ltp_loc = &driver->other->termios_locked[idx]; if (!*o_tty_loc && !o_tty) { kdev_t o_device; o_tty = (struct tty_struct *) get_free_page(GFP_KERNEL); if (!o_tty) goto end_init; o_device = MKDEV(driver->other->major, driver->other->minor_start + idx); initialize_tty_struct(o_tty); o_tty->device = o_device; o_tty->driver = *driver->other; goto repeat; } if (!*o_tp_loc && !o_tp) { o_tp = (struct termios *) kmalloc(sizeof(struct termios), GFP_KERNEL); if (!o_tp) goto end_init; *o_tp = driver->other->init_termios; goto repeat; } if (!*o_ltp_loc && !o_ltp) { o_ltp = (struct termios *) kmalloc(sizeof(struct termios), GFP_KERNEL); if (!o_ltp) goto end_init; memset(o_ltp, 0, sizeof(struct termios)); goto repeat; } } /* Now we have allocated all the structures: update all the pointers.. */ if (!*tp_loc) { *tp_loc = tp; tp = NULL; } if (!*ltp_loc) { *ltp_loc = ltp; ltp = NULL; } if (!*tty_loc) { tty->termios = *tp_loc; tty->termios_locked = *ltp_loc; *tty_loc = tty; (*driver->refcount)++; (*tty_loc)->count++; if (tty->ldisc.open) { retval = (tty->ldisc.open)(tty); if (retval < 0) { (*tty_loc)->count--; tty = NULL; goto end_init; } } tty = NULL; } else { if ((*tty_loc)->flags & (1 count++; } if (driver->type == TTY_DRIVER_TYPE_PTY) { if (!*o_tp_loc) { *o_tp_loc = o_tp; o_tp = NULL; } if (!*o_ltp_loc) { *o_ltp_loc = o_ltp; o_ltp = NULL; } if (!*o_tty_loc) { o_tty->termios = *o_tp_loc; o_tty->termios_locked = *o_ltp_loc; *o_tty_loc = o_tty; (*driver->other->refcount)++; if (o_tty->ldisc.open) { retval = (o_tty->ldisc.open)(o_tty); if (retval < 0) { (*tty_loc)->count--; o_tty = NULL; goto end_init; } } o_tty = NULL; } (*tty_loc)->link = *o_tty_loc; (*o_tty_loc)->link = *tty_loc; if (driver->subtype == PTY_TYPE_MASTER) (*o_tty_loc)->count++; } (*tty_loc)->driver = *driver; *ret_tty = *tty_loc; retval = 0; end_init: if (tty) free_page((unsigned long) tty); if (o_tty) free_page((unsigned long) o_tty); if (tp) kfree_s(tp, sizeof(struct termios)); if (o_tp) kfree_s(o_tp, sizeof(struct termios)); if (ltp) kfree_s(ltp, sizeof(struct termios)); if (o_ltp) kfree_s(o_ltp, sizeof(struct termios)); return retval; } /* * Even releasing the tty structures is a tricky business.. We have * to be very careful that the structures are all released at the * same time, as interrupts might otherwise get the wrong pointers. */ static void release_dev(struct file * filp) { struct tty_struct *tty, *o_tty; struct termios *tp, *o_tp, *ltp, *o_ltp; struct task_struct **p; int idx; tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, filp->f_inode->i_rdev, "release_dev")) return; check_tty_count(tty, "release_dev"); tty_fasync(filp->f_inode, filp, 0); tp = tty->termios; ltp = tty->termios_locked; idx = MINOR(tty->device) - tty->driver.minor_start; #ifdef TTY_PARANOIA_CHECK if (idx < 0 || idx >= tty->driver.num) { printk("release_dev: bad idx when trying to free (%s)\n", kdevname(tty->device)); return; } if (tty != tty->driver.table[idx]) { printk("release_dev: driver.table[%d] not tty for (%s)\n", idx, kdevname(tty->device)); return; } if (tp != tty->driver.termios[idx]) { printk("release_dev: driver.termios[%d] not termios for (" "%s)\n", idx, kdevname(tty->device)); return; } if (ltp != tty->driver.termios_locked[idx]) { printk("release_dev: driver.termios_locked[%d] not termios_locked for (" "%s)\n", idx, kdevname(tty->device)); return; } #endif #ifdef TTY_DEBUG_HANGUP printk("release_dev of %s (tty count=%d)...", tty_name(tty), tty->count); #endif o_tty = tty->link; o_tp = (o_tty) ? o_tty->termios : NULL; o_ltp = (o_tty) ? o_tty->termios_locked : NULL; #ifdef TTY_PARANOIA_CHECK if (tty->driver.other) { if (o_tty != tty->driver.other->table[idx]) { printk("release_dev: other->table[%d] not o_tty for (" "%s)\n", idx, kdevname(tty->device)); return; } if (o_tp != tty->driver.other->termios[idx]) { printk("release_dev: other->termios[%d] not o_termios for (" "%s)\n", idx, kdevname(tty->device)); return; } if (o_ltp != tty->driver.other->termios_locked[idx]) { printk("release_dev: other->termios_locked[%d] not o_termios_locked for (" "%s)\n", idx, kdevname(tty->device)); return; } if (o_tty->link != tty) { printk("release_dev: bad pty pointers\n"); return; } } #endif if (tty->driver.close) tty->driver.close(tty, filp); if (tty->driver.type == TTY_DRIVER_TYPE_PTY && tty->driver.subtype == PTY_TYPE_MASTER) { if (--tty->link->count < 0) { printk("release_dev: bad pty slave count (%d) for %s\n", tty->count, tty_name(tty)); tty->link->count = 0; } } if (--tty->count < 0) { printk("release_dev: bad tty->count (%d) for %s\n", tty->count, tty_name(tty)); tty->count = 0; } if (tty->count) return; /* * We're committed; at this point, we must not block! */ if (o_tty) { if (o_tty->count) return; tty->driver.other->table[idx] = NULL; tty->driver.other->termios[idx] = NULL; kfree_s(o_tp, sizeof(struct termios)); } #ifdef TTY_DEBUG_HANGUP printk("freeing tty structure..."); #endif tty->flags |= (1 f_flags & O_NOCTTY; device = inode->i_rdev; if (device == TTY_DEV) { if (!current->tty) return -ENXIO; device = current->tty->device; /* noctty = 1; */ } if (device == CONSOLE_DEV) { device = MKDEV(TTY_MAJOR, fg_console+1); noctty = 1; } minor = MINOR(device); retval = init_dev(device, &tty); if (retval) return retval; filp->private_data = tty; check_tty_count(tty, "tty_open"); if (tty->driver.type == TTY_DRIVER_TYPE_PTY && tty->driver.subtype == PTY_TYPE_MASTER) noctty = 1; #ifdef TTY_DEBUG_HANGUP printk("opening %s...", tty_name(tty)); #endif if (tty->driver.open) retval = tty->driver.open(tty, filp); else retval = -ENODEV; if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !suser()) retval = -EBUSY; if (retval) { #ifdef TTY_DEBUG_HANGUP printk("error %d in opening %s...", retval, tty_name(tty)); #endif release_dev(filp); if (retval != -ERESTARTSYS) return retval; if (current->signal & ~current->blocked) return retval; schedule(); /* * Need to reset f_op in case a hangup happened. */ filp->f_op = &tty_fops; goto retry_open; } if (!noctty && current->leader && !current->tty && tty->session == 0) { current->tty = tty; current->tty_old_pgrp = 0; tty->session = current->session; tty->pgrp = current->pgrp; } return 0; } /* * Note that releasing a pty master also releases the child, so * we have to make the redirection checks after that and on both * sides of a pty. */ static void tty_release(struct inode * inode, struct file * filp) { release_dev(filp); } static int tty_select(struct inode * inode, struct file * filp, int sel_type, select_table * wait) { struct tty_struct * tty; tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, inode->i_rdev, "tty_select")) return 0; if (tty->ldisc.select) return (tty->ldisc.select)(tty, inode, filp, sel_type, wait); return 0; } /* * fasync_helper() is used by some character device drivers (mainly mice) * to set up the fasync queue. It returns negative on error, 0 if it did * no changes and positive if it added/deleted the entry. */ int fasync_helper(struct inode * inode, struct file * filp, int on, struct fasync_struct **fapp) { struct fasync_struct *fa, **fp; unsigned long flags; for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) { if (fa->fa_file == filp) break; } if (on) { if (fa) return 0; fa = (struct fasync_struct *)kmalloc(sizeof(struct fasync_struct), GFP_KERNEL); if (!fa) return -ENOMEM; fa->magic = FASYNC_MAGIC; fa->fa_file = filp; save_flags(flags); cli(); fa->fa_next = *fapp; *fapp = fa; restore_flags(flags); return 1; } if (!fa) return 0; save_flags(flags); cli(); *fp = fa->fa_next; restore_flags(flags); kfree(fa); return 1; } static int tty_fasync(struct inode * inode, struct file * filp, int on) { struct tty_struct * tty; int retval; tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, inode->i_rdev, "tty_fasync")) return 0; retval = fasync_helper(inode, filp, on, &tty->fasync); if (retval read_wait) tty->minimum_to_wake = 1; if (filp->f_owner == 0) { if (tty->pgrp) filp->f_owner = -tty->pgrp; else filp->f_owner = current->pid; } } else { if (!tty->fasync && !tty->read_wait) tty->minimum_to_wake = N_TTY_BUF_SIZE; } return 0; } #if 0 /* * XXX does anyone use this anymore?!? */ static int do_get_ps_info(unsigned long arg) { struct tstruct { int flag; int present[NR_TASKS]; struct task_struct tasks[NR_TASKS]; }; struct tstruct *ts = (struct tstruct *)arg; struct task_struct **p; char *c, *d; int i, n = 0; i = verify_area(VERIFY_WRITE, (void *)arg, sizeof(struct tstruct)); if (i) return i; for (p = &FIRST_TASK ; p tasks+n); for (i=0 ; ipresent+n); } else put_user(0, ts->present+n); return(0); } #endif static int tty_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg) { int retval; struct tty_struct * tty; struct tty_struct * real_tty; struct winsize tmp_ws; pid_t pgrp; unsigned char ch; char mbz = 0; tty = (struct tty_struct *)file->private_data; if (tty_paranoia_check(tty, inode->i_rdev, "tty_ioctl")) return -EINVAL; if (tty->driver.type == TTY_DRIVER_TYPE_PTY && tty->driver.subtype == PTY_TYPE_MASTER) real_tty = tty->link; else real_tty = tty; switch (cmd) { case TIOCSTI: if ((current->tty != tty) && !suser()) return -EPERM; retval = verify_area(VERIFY_READ, (void *) arg, 1); if (retval) return retval; ch = get_user((char *) arg); tty->ldisc.receive_buf(tty, &ch, &mbz, 1); return 0; case TIOCGWINSZ: retval = verify_area(VERIFY_WRITE, (void *) arg, sizeof (struct winsize)); if (retval) return retval; memcpy_tofs((struct winsize *) arg, &tty->winsize, sizeof (struct winsize)); return 0; case TIOCSWINSZ: retval = verify_area(VERIFY_READ, (void *) arg, sizeof (struct winsize)); if (retval) return retval; memcpy_fromfs(&tmp_ws, (struct winsize *) arg, sizeof (struct winsize)); if (memcmp(&tmp_ws, &tty->winsize, sizeof(struct winsize))) { if (tty->pgrp > 0) kill_pg(tty->pgrp, SIGWINCH, 1); if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) kill_pg(real_tty->pgrp, SIGWINCH, 1); } tty->winsize = tmp_ws; real_tty->winsize = tmp_ws; return 0; case TIOCCONS: if (tty->driver.type == TTY_DRIVER_TYPE_CONSOLE) { if (!suser()) return -EPERM; redirect = NULL; return 0; } if (redirect) return -EBUSY; redirect = real_tty; return 0; case FIONBIO: retval = verify_area(VERIFY_READ, (void *) arg, sizeof(int)); if (retval) return retval; arg = get_user((unsigned int *) arg); if (arg) file->f_flags |= O_NONBLOCK; else file->f_flags &= ~O_NONBLOCK; return 0; case TIOCEXCL: set_bit(TTY_EXCLUSIVE, &tty->flags); return 0; case TIOCNXCL: clear_bit(TTY_EXCLUSIVE, &tty->flags); return 0; case TIOCNOTTY: if (current->tty != tty) return -ENOTTY; if (current->leader) disassociate_ctty(0); current->tty = NULL; return 0; case TIOCSCTTY: if (current->leader && (current->session == tty->session)) return 0; /* * The process must be a session leader and * not have a controlling tty already. */ if (!current->leader || current->tty) return -EPERM; if (tty->session > 0) { /* * This tty is already the controlling * tty for another session group! */ if ((arg == 1) && suser()) { /* * Steal it away */ struct task_struct *p; for_each_task(p) if (p->tty == tty) p->tty = NULL; } else return -EPERM; } current->tty = tty; current->tty_old_pgrp = 0; tty->session = current->session; tty->pgrp = current->pgrp; return 0; case TIOCGPGRP: /* * (tty == real_tty) is a cheap way of * testing if the tty is NOT a master pty. */ if (tty == real_tty && current->tty != real_tty) return -ENOTTY; retval = verify_area(VERIFY_WRITE, (void *) arg, sizeof (pid_t)); if (retval) return retval; put_user(real_tty->pgrp, (pid_t *) arg); return 0; case TIOCSPGRP: retval = tty_check_change(real_tty); if (retval == -EIO) return -ENOTTY; if (retval) return retval; if (!current->tty || (current->tty != real_tty) || (real_tty->session != current->session)) return -ENOTTY; pgrp = get_user((pid_t *) arg); if (pgrp < 0) return -EINVAL; if (session_of_pgrp(pgrp) != current->session) return -EPERM; real_tty->pgrp = pgrp; return 0; case TIOCGETD: retval = verify_area(VERIFY_WRITE, (void *) arg, sizeof (int)); if (retval) return retval; put_user(tty->ldisc.num, (int *) arg); return 0; case TIOCSETD: retval = tty_check_change(tty); if (retval) return retval; retval = verify_area(VERIFY_READ, (void *) arg, sizeof (int)); if (retval) return retval; arg = get_user((int *) arg); return tty_set_ldisc(tty, arg); case TIOCLINUX: if (tty->driver.type != TTY_DRIVER_TYPE_CONSOLE) return -EINVAL; if (current->tty != tty && !suser()) return -EPERM; retval = verify_area(VERIFY_READ, (void *) arg, 1); if (retval) return retval; switch (retval = get_user((char *)arg)) { case 0: case 8: case 9: printk("TIOCLINUX (0/8/9) ioctl is gone - use /dev/vcs\n"); return -EINVAL; #if 0 case 1: printk("Deprecated TIOCLINUX (1) ioctl\n"); return do_get_ps_info(arg); #endif case 2: return set_selection(arg, tty, 1); case 3: return paste_selection(tty); case 4: do_unblank_screen(); return 0; case 5: return sel_loadlut(arg); case 6: /* * Make it possible to react to Shift+Mousebutton. * Note that 'shift_state' is an undocumented * kernel-internal variable; programs not closely * related to the kernel should not use this. */ retval = verify_area(VERIFY_WRITE, (void *) arg, 1); if (retval) return retval; put_user(shift_state,(char *) arg); return 0; case 7: retval = verify_area(VERIFY_WRITE, (void *) arg, 1); if (retval) return retval; put_user(mouse_reporting(),(char *) arg); return 0; case 10: set_vesa_blanking(arg); return 0; case 11: /* set kmsg redirect */ if (!suser()) return -EPERM; retval = verify_area(VERIFY_READ, (void *) arg+1, 1); if (retval) return retval; kmsg_redirect = get_user((char *)arg+1); return 0; case 12: /* get fg_console */ return fg_console; default: return -EINVAL; } case TIOCTTYGSTRUCT: retval = verify_area(VERIFY_WRITE, (void *) arg, sizeof(struct tty_struct)); if (retval) return retval; memcpy_tofs((struct tty_struct *) arg, tty, sizeof(struct tty_struct)); return 0; default: if (tty->driver.ioctl) { retval = (tty->driver.ioctl)(tty, file, cmd, arg); if (retval != -ENOIOCTLCMD) return retval; } if (tty->ldisc.ioctl) { retval = (tty->ldisc.ioctl)(tty, file, cmd, arg); if (retval != -ENOIOCTLCMD) return retval; } return -EINVAL; } } /* * This implements the "Secure Attention Key" --- the idea is to * prevent trojan horses by killing all processes associated with this * tty when the user hits the "Secure Attention Key". Required for * super-paranoid applications --- see the Orange Book for more details. * * This code could be nicer; ideally it should send a HUP, wait a few * seconds, then send a INT, and then a KILL signal. But you then * have to coordinate with the init process, since all processes associated * with the current tty must be dead before the new getty is allowed * to spawn. */ void do_SAK( struct tty_struct *tty) { #ifdef TTY_SOFT_SAK tty_hangup(tty); #else struct task_struct **p; int session; int i; struct file *filp; if (!tty) return; session = tty->session; if (tty->ldisc.flush_buffer) tty->ldisc.flush_buffer(tty); if (tty->driver.flush_buffer) tty->driver.flush_buffer(tty); for (p = &LAST_TASK ; p > &FIRST_TASK ; --p) { if (!(*p)) continue; if (((*p)->tty == tty) || ((session > 0) && ((*p)->session == session))) send_sig(SIGKILL, *p, 1); else { for (i=0; i < NR_OPEN; i++) { filp = (*p)->files->fd[i]; if (filp && (filp->f_op == &tty_fops) && (filp->private_data == tty)) { send_sig(SIGKILL, *p, 1); break; } } } } #endif } /* * This routine is called out of the software interrupt to flush data * from the flip buffer to the line discipline. */ static void flush_to_ldisc(void *private_) { struct tty_struct *tty = (struct tty_struct *) private_; unsigned char *cp; char *fp; int count; if (tty->flip.buf_num) { cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE; fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; tty->flip.buf_num = 0; cli(); tty->flip.char_buf_ptr = tty->flip.char_buf; tty->flip.flag_buf_ptr = tty->flip.flag_buf; } else { cp = tty->flip.char_buf; fp = tty->flip.flag_buf; tty->flip.buf_num = 1; cli(); tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE; tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; } count = tty->flip.count; tty->flip.count = 0; sti(); #if 0 if (count > tty->max_flip_cnt) tty->max_flip_cnt = count; #endif tty->ldisc.receive_buf(tty, cp, fp, count); } /* * This subroutine initializes a tty structure. */ static void initialize_tty_struct(struct tty_struct *tty) { memset(tty, 0, sizeof(struct tty_struct)); tty->magic = TTY_MAGIC; tty->ldisc = ldiscs[N_TTY]; tty->pgrp = -1; tty->flip.char_buf_ptr = tty->flip.char_buf; tty->flip.flag_buf_ptr = tty->flip.flag_buf; tty->flip.tqueue.routine = flush_to_ldisc; tty->flip.tqueue.data = tty; } /* * The default put_char routine if the driver did not define one. */ void tty_default_put_char(struct tty_struct *tty, unsigned char ch) { tty->driver.write(tty, 0, &ch, 1); } /* * Called by a tty driver to register itself. */ int tty_register_driver(struct tty_driver *driver) { int error; if (driver->flags & TTY_DRIVER_INSTALLED) return 0; error = register_chrdev(driver->major, driver->name, &tty_fops); if (error < 0) return error; else if(driver->major == 0) driver->major = error; if (!driver->put_char) driver->put_char = tty_default_put_char; driver->prev = 0; driver->next = tty_drivers; if (tty_drivers) tty_drivers->prev = driver; tty_drivers = driver; return error; } /* * Called by a tty driver to unregister itself. */ int tty_unregister_driver(struct tty_driver *driver) { int retval; struct tty_driver *p; int found = 0; const char *othername = NULL; if (*driver->refcount) return -EBUSY; for (p = tty_drivers; p; p = p->next) { if (p == driver) found++; else if (p->major == driver->major) othername = p->name; } if (!found) return -ENOENT; if (othername == NULL) { retval = unregister_chrdev(driver->major, driver->name); if (retval) return retval; } else register_chrdev(driver->major, othername, &tty_fops); if (driver->prev) driver->prev->next = driver->next; else tty_drivers = driver->next; if (driver->next) driver->next->prev = driver->prev; return 0; } /* * Initialize the console device. This is called *early*, so * we can't necessarily depend on lots of kernel help here. * Just do some early initializations, and do the complex setup * later. */ long console_init(long kmem_start, long kmem_end) { /* Setup the default TTY line discipline. */ memset(ldiscs, 0, sizeof(ldiscs)); (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); /* * Set up the standard termios. Individual tty drivers may * deviate from this; this is used as a template. */ memset(&tty_std_termios, 0, sizeof(struct termios)); memcpy(tty_std_termios.c_cc, INIT_C_CC, NCCS); tty_std_termios.c_iflag = ICRNL | IXON; tty_std_termios.c_oflag = OPOST | ONLCR; tty_std_termios.c_cflag = B38400 | CS8 | CREAD | HUPCL; tty_std_termios.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN; /* * set up the console device so that later boot sequences can * inform about problems etc.. */ return con_init(kmem_start); } static struct tty_driver dev_tty_driver, dev_console_driver; /* * Ok, now we can initialize the rest of the tty devices and can count * on memory allocations, interrupts etc.. */ int tty_init(void) { if (sizeof(struct tty_struct) > PAGE_SIZE) panic("size of tty structure > PAGE_SIZE!"); /* * dev_tty_driver and dev_console_driver are actually magic * devices which get redirected at open time. Nevertheless, * we register them so that register_chrdev is called * appropriately. */ memset(&dev_tty_driver, 0, sizeof(struct tty_driver)); dev_tty_driver.magic = TTY_DRIVER_MAGIC; dev_tty_driver.name = "tty"; dev_tty_driver.name_base = 0; dev_tty_driver.major = TTY_MAJOR; dev_tty_driver.minor_start = 0; dev_tty_driver.num = 1; if (tty_register_driver(&dev_tty_driver)) panic("Couldn't register /dev/tty driver\n"); dev_console_driver = dev_tty_driver; dev_console_driver.name = "console"; dev_console_driver.major = TTYAUX_MAJOR; if (tty_register_driver(&dev_console_driver)) panic("Couldn't register /dev/console driver\n"); kbd_init(); #ifdef CONFIG_SERIAL rs_init(); #endif #ifdef CONFIG_SCC scc_init(); #endif #ifdef CONFIG_CYCLADES cy_init(); #endif #ifdef CONFIG_STALLION stl_init(); #endif #ifdef CONFIG_ISTALLION stli_init(); #endif #ifdef CONFIG_DIGI pcxe_init(); #endif #ifdef CONFIG_RISCOM8 riscom8_init(); #endif #ifdef CONFIG_BAYCOM baycom_init(); #endif pty_init(); vcs_init(); return 0; }