/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_TTY_H #define _LINUX_TTY_H #include <linux/fs.h> #include <linux/major.h> #include <linux/termios.h> #include <linux/workqueue.h> #include <linux/tty_driver.h> #include <linux/tty_ldisc.h> #include <linux/tty_port.h> #include <linux/mutex.h> #include <linux/tty_flags.h> #include <uapi/linux/tty.h> #include <linux/rwsem.h> #include <linux/llist.h> /* * (Note: the *_driver.minor_start values 1, 64, 128, 192 are * hardcoded at present.) */ #define NR_UNIX98_PTY_DEFAULT … #define NR_UNIX98_PTY_RESERVE … #define NR_UNIX98_PTY_MAX … /* * This character is the same as _POSIX_VDISABLE: it cannot be used as * a c_cc[] character, but indicates that a particular special character * isn't in use (eg VINTR has no character etc) */ #define __DISABLED_CHAR … #define INTR_CHAR(tty) … #define QUIT_CHAR(tty) … #define ERASE_CHAR(tty) … #define KILL_CHAR(tty) … #define EOF_CHAR(tty) … #define TIME_CHAR(tty) … #define MIN_CHAR(tty) … #define SWTC_CHAR(tty) … #define START_CHAR(tty) … #define STOP_CHAR(tty) … #define SUSP_CHAR(tty) … #define EOL_CHAR(tty) … #define REPRINT_CHAR(tty) … #define DISCARD_CHAR(tty) … #define WERASE_CHAR(tty) … #define LNEXT_CHAR(tty) … #define EOL2_CHAR(tty) … #define _I_FLAG(tty, f) … #define _O_FLAG(tty, f) … #define _C_FLAG(tty, f) … #define _L_FLAG(tty, f) … #define I_IGNBRK(tty) … #define I_BRKINT(tty) … #define I_IGNPAR(tty) … #define I_PARMRK(tty) … #define I_INPCK(tty) … #define I_ISTRIP(tty) … #define I_INLCR(tty) … #define I_IGNCR(tty) … #define I_ICRNL(tty) … #define I_IUCLC(tty) … #define I_IXON(tty) … #define I_IXANY(tty) … #define I_IXOFF(tty) … #define I_IMAXBEL(tty) … #define I_IUTF8(tty) … #define O_OPOST(tty) … #define O_OLCUC(tty) … #define O_ONLCR(tty) … #define O_OCRNL(tty) … #define O_ONOCR(tty) … #define O_ONLRET(tty) … #define O_OFILL(tty) … #define O_OFDEL(tty) … #define O_NLDLY(tty) … #define O_CRDLY(tty) … #define O_TABDLY(tty) … #define O_BSDLY(tty) … #define O_VTDLY(tty) … #define O_FFDLY(tty) … #define C_BAUD(tty) … #define C_CSIZE(tty) … #define C_CSTOPB(tty) … #define C_CREAD(tty) … #define C_PARENB(tty) … #define C_PARODD(tty) … #define C_HUPCL(tty) … #define C_CLOCAL(tty) … #define C_CIBAUD(tty) … #define C_CRTSCTS(tty) … #define C_CMSPAR(tty) … #define L_ISIG(tty) … #define L_ICANON(tty) … #define L_XCASE(tty) … #define L_ECHO(tty) … #define L_ECHOE(tty) … #define L_ECHOK(tty) … #define L_ECHONL(tty) … #define L_NOFLSH(tty) … #define L_TOSTOP(tty) … #define L_ECHOCTL(tty) … #define L_ECHOPRT(tty) … #define L_ECHOKE(tty) … #define L_FLUSHO(tty) … #define L_PENDIN(tty) … #define L_IEXTEN(tty) … #define L_EXTPROC(tty) … struct device; struct signal_struct; struct tty_operations; /** * struct tty_struct - state associated with a tty while open * * @kref: reference counting by tty_kref_get() and tty_kref_put(), reaching zero * frees the structure * @dev: class device or %NULL (e.g. ptys, serdev) * @driver: &struct tty_driver operating this tty * @ops: &struct tty_operations of @driver for this tty (open, close, etc.) * @index: index of this tty (e.g. to construct @name like tty12) * @ldisc_sem: protects line discipline changes (@ldisc) -- lock tty not pty * @ldisc: the current line discipline for this tty (n_tty by default) * @atomic_write_lock: protects against concurrent writers, i.e. locks * @write_cnt, @write_buf and similar * @legacy_mutex: leftover from history (BKL -> BTM -> @legacy_mutex), * protecting several operations on this tty * @throttle_mutex: protects against concurrent tty_throttle_safe() and * tty_unthrottle_safe() (but not tty_unthrottle()) * @termios_rwsem: protects @termios and @termios_locked * @winsize_mutex: protects @winsize * @termios: termios for the current tty, copied from/to @driver.termios * @termios_locked: locked termios (by %TIOCGLCKTRMIOS and %TIOCSLCKTRMIOS * ioctls) * @name: name of the tty constructed by tty_line_name() (e.g. ttyS3) * @flags: bitwise OR of %TTY_THROTTLED, %TTY_IO_ERROR, ... * @count: count of open processes, reaching zero cancels all the work for * this tty and drops a @kref too (but does not free this tty) * @winsize: size of the terminal "window" (cf. @winsize_mutex) * @flow: flow settings grouped together * @flow.lock: lock for @flow members * @flow.stopped: tty stopped/started by stop_tty()/start_tty() * @flow.tco_stopped: tty stopped/started by %TCOOFF/%TCOON ioctls (it has * precedence over @flow.stopped) * @ctrl: control settings grouped together * @ctrl.lock: lock for @ctrl members * @ctrl.pgrp: process group of this tty (setpgrp(2)) * @ctrl.session: session of this tty (setsid(2)). Writes are protected by both * @ctrl.lock and @legacy_mutex, readers must use at least one of * them. * @ctrl.pktstatus: packet mode status (bitwise OR of %TIOCPKT_ constants) * @ctrl.packet: packet mode enabled * @hw_stopped: not controlled by the tty layer, under @driver's control for CTS * handling * @receive_room: bytes permitted to feed to @ldisc without any being lost * @flow_change: controls behavior of throttling, see tty_throttle_safe() and * tty_unthrottle_safe() * @link: link to another pty (master -> slave and vice versa) * @fasync: state for %O_ASYNC (for %SIGIO); managed by fasync_helper() * @write_wait: concurrent writers are waiting in this queue until they are * allowed to write * @read_wait: readers wait for data in this queue * @hangup_work: normally a work to perform a hangup (do_tty_hangup()); while * freeing the tty, (re)used to release_one_tty() * @disc_data: pointer to @ldisc's private data (e.g. to &struct n_tty_data) * @driver_data: pointer to @driver's private data (e.g. &struct uart_state) * @files_lock: protects @tty_files list * @tty_files: list of (re)openers of this tty (i.e. linked &struct * tty_file_private) * @closing: when set during close, n_tty processes only START & STOP chars * @write_buf: temporary buffer used during tty_write() to copy user data to * @write_cnt: count of bytes written in tty_write() to @write_buf * @SAK_work: if the tty has a pending do_SAK, it is queued here * @port: persistent storage for this device (i.e. &struct tty_port) * * All of the state associated with a tty while the tty is open. Persistent * storage for tty devices is referenced here as @port and is documented in * &struct tty_port. */ struct tty_struct { … } __randomize_layout; /* Each of a tty's open files has private_data pointing to tty_file_private */ struct tty_file_private { … }; /** * DOC: TTY Struct Flags * * These bits are used in the :c:member:`tty_struct.flags` field. * * So that interrupts won't be able to mess up the queues, * copy_to_cooked must be atomic with respect to itself, as must * tty->write. Thus, you must use the inline functions set_bit() and * clear_bit() to make things atomic. * * TTY_THROTTLED * Driver input is throttled. The ldisc should call * :c:member:`tty_driver.unthrottle()` in order to resume reception when * it is ready to process more data (at threshold min). * * TTY_IO_ERROR * If set, causes all subsequent userspace read/write calls on the tty to * fail, returning -%EIO. (May be no ldisc too.) * * TTY_OTHER_CLOSED * Device is a pty and the other side has closed. * * TTY_EXCLUSIVE * Exclusive open mode (a single opener). * * TTY_DO_WRITE_WAKEUP * If set, causes the driver to call the * :c:member:`tty_ldisc_ops.write_wakeup()` method in order to resume * transmission when it can accept more data to transmit. * * TTY_LDISC_OPEN * Indicates that a line discipline is open. For debugging purposes only. * * TTY_PTY_LOCK * A flag private to pty code to implement %TIOCSPTLCK/%TIOCGPTLCK logic. * * TTY_NO_WRITE_SPLIT * Prevent driver from splitting up writes into smaller chunks (preserve * write boundaries to driver). * * TTY_HUPPED * The TTY was hung up. This is set post :c:member:`tty_driver.hangup()`. * * TTY_HUPPING * The TTY is in the process of hanging up to abort potential readers. * * TTY_LDISC_CHANGING * Line discipline for this TTY is being changed. I/O should not block * when this is set. Use tty_io_nonblock() to check. * * TTY_LDISC_HALTED * Line discipline for this TTY was stopped. No work should be queued to * this ldisc. */ #define TTY_THROTTLED … #define TTY_IO_ERROR … #define TTY_OTHER_CLOSED … #define TTY_EXCLUSIVE … #define TTY_DO_WRITE_WAKEUP … #define TTY_LDISC_OPEN … #define TTY_PTY_LOCK … #define TTY_NO_WRITE_SPLIT … #define TTY_HUPPED … #define TTY_HUPPING … #define TTY_LDISC_CHANGING … #define TTY_LDISC_HALTED … static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file) { … } static inline bool tty_io_error(struct tty_struct *tty) { … } static inline bool tty_throttled(struct tty_struct *tty) { … } #ifdef CONFIG_TTY void tty_kref_put(struct tty_struct *tty); struct pid *tty_get_pgrp(struct tty_struct *tty); void tty_vhangup_self(void); void disassociate_ctty(int priv); dev_t tty_devnum(struct tty_struct *tty); void proc_clear_tty(struct task_struct *p); struct tty_struct *get_current_tty(void); /* tty_io.c */ int __init tty_init(void); const char *tty_name(const struct tty_struct *tty); struct tty_struct *tty_kopen_exclusive(dev_t device); struct tty_struct *tty_kopen_shared(dev_t device); void tty_kclose(struct tty_struct *tty); int tty_dev_name_to_number(const char *name, dev_t *number); #else static inline void tty_kref_put(struct tty_struct *tty) { } static inline struct pid *tty_get_pgrp(struct tty_struct *tty) { return NULL; } static inline void tty_vhangup_self(void) { } static inline void disassociate_ctty(int priv) { } static inline dev_t tty_devnum(struct tty_struct *tty) { return 0; } static inline void proc_clear_tty(struct task_struct *p) { } static inline struct tty_struct *get_current_tty(void) { return NULL; } /* tty_io.c */ static inline int __init tty_init(void) { return 0; } static inline const char *tty_name(const struct tty_struct *tty) { return "(none)"; } static inline struct tty_struct *tty_kopen_exclusive(dev_t device) { return ERR_PTR(-ENODEV); } static inline void tty_kclose(struct tty_struct *tty) { } static inline int tty_dev_name_to_number(const char *name, dev_t *number) { return -ENOTSUPP; } #endif extern struct ktermios tty_std_termios; int vcs_init(void); extern const struct class tty_class; /** * tty_kref_get - get a tty reference * @tty: tty device * * Returns: a new reference to a tty object * * Locking: The caller must hold sufficient locks/counts to ensure that their * existing reference cannot go away. */ static inline struct tty_struct *tty_kref_get(struct tty_struct *tty) { … } const char *tty_driver_name(const struct tty_struct *tty); void tty_wait_until_sent(struct tty_struct *tty, long timeout); void stop_tty(struct tty_struct *tty); void start_tty(struct tty_struct *tty); void tty_write_message(struct tty_struct *tty, char *msg); int tty_send_xchar(struct tty_struct *tty, u8 ch); int tty_put_char(struct tty_struct *tty, u8 c); unsigned int tty_chars_in_buffer(struct tty_struct *tty); unsigned int tty_write_room(struct tty_struct *tty); void tty_driver_flush_buffer(struct tty_struct *tty); void tty_unthrottle(struct tty_struct *tty); bool tty_throttle_safe(struct tty_struct *tty); bool tty_unthrottle_safe(struct tty_struct *tty); int tty_do_resize(struct tty_struct *tty, struct winsize *ws); int tty_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount); int tty_get_tiocm(struct tty_struct *tty); int is_current_pgrp_orphaned(void); void tty_hangup(struct tty_struct *tty); void tty_vhangup(struct tty_struct *tty); int tty_hung_up_p(struct file *filp); void do_SAK(struct tty_struct *tty); void __do_SAK(struct tty_struct *tty); void no_tty(void); speed_t tty_termios_baud_rate(const struct ktermios *termios); void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud); void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud); /** * tty_get_baud_rate - get tty bit rates * @tty: tty to query * * Returns: the baud rate as an integer for this terminal * * Locking: The termios lock must be held by the caller. */ static inline speed_t tty_get_baud_rate(const struct tty_struct *tty) { … } unsigned char tty_get_char_size(unsigned int cflag); unsigned char tty_get_frame_size(unsigned int cflag); void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old); bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b); int tty_set_termios(struct tty_struct *tty, struct ktermios *kt); void tty_wakeup(struct tty_struct *tty); int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); int tty_perform_flush(struct tty_struct *tty, unsigned long arg); struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); void tty_release_struct(struct tty_struct *tty, int idx); void tty_init_termios(struct tty_struct *tty); void tty_save_termios(struct tty_struct *tty); int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty); extern struct mutex tty_mutex; /* n_tty.c */ void n_tty_inherit_ops(struct tty_ldisc_ops *ops); #ifdef CONFIG_TTY void __init n_tty_init(void); #else static inline void n_tty_init(void) { } #endif /* tty_audit.c */ #ifdef CONFIG_AUDIT void tty_audit_exit(void); void tty_audit_fork(struct signal_struct *sig); int tty_audit_push(void); #else static inline void tty_audit_exit(void) { } static inline void tty_audit_fork(struct signal_struct *sig) { } static inline int tty_audit_push(void) { return 0; } #endif /* tty_ioctl.c */ int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd, unsigned long arg); /* vt.c */ int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); /* tty_mutex.c */ /* functions for preparation of BKL removal */ void tty_lock(struct tty_struct *tty); int tty_lock_interruptible(struct tty_struct *tty); void tty_unlock(struct tty_struct *tty); void tty_lock_slave(struct tty_struct *tty); void tty_unlock_slave(struct tty_struct *tty); void tty_set_lock_subclass(struct tty_struct *tty); #endif
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