xref: /linux-6.15/include/linux/tty.h (revision 930cc144)
1 #ifndef _LINUX_TTY_H
2 #define _LINUX_TTY_H
3 
4 /*
5  * 'tty.h' defines some structures used by tty_io.c and some defines.
6  */
7 
8 #ifdef __KERNEL__
9 #include <linux/fs.h>
10 #include <linux/major.h>
11 #include <linux/termios.h>
12 #include <linux/workqueue.h>
13 #include <linux/tty_driver.h>
14 #include <linux/tty_ldisc.h>
15 #include <linux/mutex.h>
16 
17 #include <asm/system.h>
18 
19 
20 /*
21  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
22  * hardcoded at present.)
23  */
24 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
25 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
26 #define NR_LDISCS		19
27 
28 /* line disciplines */
29 #define N_TTY		0
30 #define N_SLIP		1
31 #define N_MOUSE		2
32 #define N_PPP		3
33 #define N_STRIP		4
34 #define N_AX25		5
35 #define N_X25		6	/* X.25 async */
36 #define N_6PACK		7
37 #define N_MASC		8	/* Reserved for Mobitex module <[email protected]> */
38 #define N_R3964		9	/* Reserved for Simatic R3964 module */
39 #define N_PROFIBUS_FDL	10	/* Reserved for Profibus */
40 #define N_IRDA		11	/* Linux IrDa - http://irda.sourceforge.net/ */
41 #define N_SMSBLOCK	12	/* SMS block mode - for talking to GSM data */
42 				/* cards about SMS messages */
43 #define N_HDLC		13	/* synchronous HDLC */
44 #define N_SYNC_PPP	14	/* synchronous PPP */
45 #define N_HCI		15	/* Bluetooth HCI UART */
46 #define N_GIGASET_M101	16	/* Siemens Gigaset M101 serial DECT adapter */
47 #define N_SLCAN		17	/* Serial / USB serial CAN Adaptors */
48 #define N_PPS		18	/* Pulse per Second */
49 
50 /*
51  * This character is the same as _POSIX_VDISABLE: it cannot be used as
52  * a c_cc[] character, but indicates that a particular special character
53  * isn't in use (eg VINTR has no character etc)
54  */
55 #define __DISABLED_CHAR '\0'
56 
57 struct tty_buffer {
58 	struct tty_buffer *next;
59 	char *char_buf_ptr;
60 	unsigned char *flag_buf_ptr;
61 	int used;
62 	int size;
63 	int commit;
64 	int read;
65 	/* Data points here */
66 	unsigned long data[0];
67 };
68 
69 struct tty_bufhead {
70 	struct delayed_work work;
71 	spinlock_t lock;
72 	struct tty_buffer *head;	/* Queue head */
73 	struct tty_buffer *tail;	/* Active buffer */
74 	struct tty_buffer *free;	/* Free queue head */
75 	int memory_used;		/* Buffer space used excluding
76 								free queue */
77 };
78 /*
79  * When a break, frame error, or parity error happens, these codes are
80  * stuffed into the flags buffer.
81  */
82 #define TTY_NORMAL	0
83 #define TTY_BREAK	1
84 #define TTY_FRAME	2
85 #define TTY_PARITY	3
86 #define TTY_OVERRUN	4
87 
88 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
89 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
90 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
91 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
92 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
93 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
94 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
95 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
96 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
97 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
98 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
99 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
100 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
101 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
102 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
103 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
104 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
105 
106 #define _I_FLAG(tty, f)	((tty)->termios->c_iflag & (f))
107 #define _O_FLAG(tty, f)	((tty)->termios->c_oflag & (f))
108 #define _C_FLAG(tty, f)	((tty)->termios->c_cflag & (f))
109 #define _L_FLAG(tty, f)	((tty)->termios->c_lflag & (f))
110 
111 #define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
112 #define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
113 #define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
114 #define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
115 #define I_INPCK(tty)	_I_FLAG((tty), INPCK)
116 #define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
117 #define I_INLCR(tty)	_I_FLAG((tty), INLCR)
118 #define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
119 #define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
120 #define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
121 #define I_IXON(tty)	_I_FLAG((tty), IXON)
122 #define I_IXANY(tty)	_I_FLAG((tty), IXANY)
123 #define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
124 #define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
125 #define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
126 
127 #define O_OPOST(tty)	_O_FLAG((tty), OPOST)
128 #define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
129 #define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
130 #define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
131 #define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
132 #define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
133 #define O_OFILL(tty)	_O_FLAG((tty), OFILL)
134 #define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
135 #define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
136 #define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
137 #define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
138 #define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
139 #define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
140 #define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
141 
142 #define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
143 #define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
144 #define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
145 #define C_CREAD(tty)	_C_FLAG((tty), CREAD)
146 #define C_PARENB(tty)	_C_FLAG((tty), PARENB)
147 #define C_PARODD(tty)	_C_FLAG((tty), PARODD)
148 #define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
149 #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
150 #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
151 #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
152 
153 #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
154 #define L_ICANON(tty)	_L_FLAG((tty), ICANON)
155 #define L_XCASE(tty)	_L_FLAG((tty), XCASE)
156 #define L_ECHO(tty)	_L_FLAG((tty), ECHO)
157 #define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
158 #define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
159 #define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
160 #define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
161 #define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
162 #define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
163 #define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
164 #define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
165 #define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
166 #define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
167 #define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
168 
169 struct device;
170 struct signal_struct;
171 
172 /*
173  * Port level information. Each device keeps its own port level information
174  * so provide a common structure for those ports wanting to use common support
175  * routines.
176  *
177  * The tty port has a different lifetime to the tty so must be kept apart.
178  * In addition be careful as tty -> port mappings are valid for the life
179  * of the tty object but in many cases port -> tty mappings are valid only
180  * until a hangup so don't use the wrong path.
181  */
182 
183 struct tty_port {
184 	struct tty_struct	*tty;		/* Back pointer */
185 	spinlock_t		lock;		/* Lock protecting tty field */
186 	int			blocked_open;	/* Waiting to open */
187 	int			count;		/* Usage count */
188 	wait_queue_head_t	open_wait;	/* Open waiters */
189 	wait_queue_head_t	close_wait;	/* Close waiters */
190 	unsigned long		flags;		/* TTY flags ASY_*/
191 	struct mutex		mutex;		/* Locking */
192 	unsigned char		*xmit_buf;	/* Optional buffer */
193 	int			close_delay;	/* Close port delay */
194 	int			closing_wait;	/* Delay for output */
195 };
196 
197 /*
198  * Where all of the state associated with a tty is kept while the tty
199  * is open.  Since the termios state should be kept even if the tty
200  * has been closed --- for things like the baud rate, etc --- it is
201  * not stored here, but rather a pointer to the real state is stored
202  * here.  Possible the winsize structure should have the same
203  * treatment, but (1) the default 80x24 is usually right and (2) it's
204  * most often used by a windowing system, which will set the correct
205  * size each time the window is created or resized anyway.
206  * 						- TYT, 9/14/92
207  */
208 
209 struct tty_operations;
210 
211 struct tty_struct {
212 	int	magic;
213 	struct kref kref;
214 	struct tty_driver *driver;
215 	const struct tty_operations *ops;
216 	int index;
217 	/* The ldisc objects are protected by tty_ldisc_lock at the moment */
218 	struct tty_ldisc ldisc;
219 	struct mutex termios_mutex;
220 	spinlock_t ctrl_lock;
221 	/* Termios values are protected by the termios mutex */
222 	struct ktermios *termios, *termios_locked;
223 	struct termiox *termiox;	/* May be NULL for unsupported */
224 	char name[64];
225 	struct pid *pgrp;		/* Protected by ctrl lock */
226 	struct pid *session;
227 	unsigned long flags;
228 	int count;
229 	struct winsize winsize;		/* termios mutex */
230 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
231 	unsigned char low_latency:1, warned:1;
232 	unsigned char ctrl_status;	/* ctrl_lock */
233 	unsigned int receive_room;	/* Bytes free for queue */
234 
235 	struct tty_struct *link;
236 	struct fasync_struct *fasync;
237 	struct tty_bufhead buf;		/* Locked internally */
238 	int alt_speed;		/* For magic substitution of 38400 bps */
239 	wait_queue_head_t write_wait;
240 	wait_queue_head_t read_wait;
241 	struct work_struct hangup_work;
242 	void *disc_data;
243 	void *driver_data;
244 	struct list_head tty_files;
245 
246 #define N_TTY_BUF_SIZE 4096
247 
248 	/*
249 	 * The following is data for the N_TTY line discipline.  For
250 	 * historical reasons, this is included in the tty structure.
251 	 * Mostly locked by the BKL.
252 	 */
253 	unsigned int column;
254 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
255 	unsigned char closing:1;
256 	unsigned short minimum_to_wake;
257 	unsigned long overrun_time;
258 	int num_overrun;
259 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
260 	char *read_buf;
261 	int read_head;
262 	int read_tail;
263 	int read_cnt;
264 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
265 	int canon_data;
266 	unsigned long canon_head;
267 	unsigned int canon_column;
268 	struct mutex atomic_read_lock;
269 	struct mutex atomic_write_lock;
270 	unsigned char *write_buf;
271 	int write_cnt;
272 	spinlock_t read_lock;
273 	/* If the tty has a pending do_SAK, queue it here - akpm */
274 	struct work_struct SAK_work;
275 	struct tty_port *port;
276 };
277 
278 /* tty magic number */
279 #define TTY_MAGIC		0x5401
280 
281 /*
282  * These bits are used in the flags field of the tty structure.
283  *
284  * So that interrupts won't be able to mess up the queues,
285  * copy_to_cooked must be atomic with respect to itself, as must
286  * tty->write.  Thus, you must use the inline functions set_bit() and
287  * clear_bit() to make things atomic.
288  */
289 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
290 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
291 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
292 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
293 #define TTY_DEBUG 		4	/* Debugging */
294 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
295 #define TTY_PUSH 		6	/* n_tty private */
296 #define TTY_CLOSING 		7	/* ->close() in progress */
297 #define TTY_LDISC 		9	/* Line discipline attached */
298 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
299 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
300 #define TTY_PTY_LOCK 		16	/* pty private */
301 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
302 #define TTY_HUPPED 		18	/* Post driver->hangup() */
303 #define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
304 #define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
305 
306 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
307 
308 extern void tty_write_flush(struct tty_struct *);
309 
310 extern struct ktermios tty_std_termios;
311 
312 extern int kmsg_redirect;
313 
314 extern void console_init(void);
315 extern int vcs_init(void);
316 
317 extern struct class *tty_class;
318 
319 /**
320  *	tty_kref_get		-	get a tty reference
321  *	@tty: tty device
322  *
323  *	Return a new reference to a tty object. The caller must hold
324  *	sufficient locks/counts to ensure that their existing reference cannot
325  *	go away
326  */
327 
328 extern inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
329 {
330 	if (tty)
331 		kref_get(&tty->kref);
332 	return tty;
333 }
334 extern void tty_kref_put(struct tty_struct *tty);
335 
336 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
337 			      const char *routine);
338 extern char *tty_name(struct tty_struct *tty, char *buf);
339 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
340 extern int tty_check_change(struct tty_struct *tty);
341 extern void stop_tty(struct tty_struct *tty);
342 extern void start_tty(struct tty_struct *tty);
343 extern int tty_register_driver(struct tty_driver *driver);
344 extern int tty_unregister_driver(struct tty_driver *driver);
345 extern struct device *tty_register_device(struct tty_driver *driver,
346 					  unsigned index, struct device *dev);
347 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
348 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
349 			     int buflen);
350 extern void tty_write_message(struct tty_struct *tty, char *msg);
351 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
352 extern int tty_chars_in_buffer(struct tty_struct *tty);
353 extern int tty_write_room(struct tty_struct *tty);
354 extern void tty_driver_flush_buffer(struct tty_struct *tty);
355 extern void tty_throttle(struct tty_struct *tty);
356 extern void tty_unthrottle(struct tty_struct *tty);
357 extern int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
358 						struct winsize *ws);
359 extern void tty_shutdown(struct tty_struct *tty);
360 extern void tty_free_termios(struct tty_struct *tty);
361 extern int is_current_pgrp_orphaned(void);
362 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
363 extern int is_ignored(int sig);
364 extern int tty_signal(int sig, struct tty_struct *tty);
365 extern void tty_hangup(struct tty_struct *tty);
366 extern void tty_vhangup(struct tty_struct *tty);
367 extern void tty_vhangup_self(void);
368 extern void tty_unhangup(struct file *filp);
369 extern int tty_hung_up_p(struct file *filp);
370 extern void do_SAK(struct tty_struct *tty);
371 extern void __do_SAK(struct tty_struct *tty);
372 extern void disassociate_ctty(int priv);
373 extern void no_tty(void);
374 extern void tty_flip_buffer_push(struct tty_struct *tty);
375 extern void tty_buffer_free_all(struct tty_struct *tty);
376 extern void tty_buffer_flush(struct tty_struct *tty);
377 extern void tty_buffer_init(struct tty_struct *tty);
378 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
379 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
380 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
381 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
382 						speed_t ibaud, speed_t obaud);
383 extern void tty_encode_baud_rate(struct tty_struct *tty,
384 						speed_t ibaud, speed_t obaud);
385 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
386 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
387 
388 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
389 extern void tty_ldisc_deref(struct tty_ldisc *);
390 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
391 extern const struct file_operations tty_ldiscs_proc_fops;
392 
393 extern void tty_wakeup(struct tty_struct *tty);
394 extern void tty_ldisc_flush(struct tty_struct *tty);
395 
396 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
397 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
398 			unsigned int cmd, unsigned long arg);
399 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
400 extern dev_t tty_devnum(struct tty_struct *tty);
401 extern void proc_clear_tty(struct task_struct *p);
402 extern struct tty_struct *get_current_tty(void);
403 extern void tty_default_fops(struct file_operations *fops);
404 extern struct tty_struct *alloc_tty_struct(void);
405 extern void free_tty_struct(struct tty_struct *tty);
406 extern void initialize_tty_struct(struct tty_struct *tty,
407 		struct tty_driver *driver, int idx);
408 extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
409 								int first_ok);
410 extern void tty_release_dev(struct file *filp);
411 extern int tty_init_termios(struct tty_struct *tty);
412 
413 extern struct mutex tty_mutex;
414 
415 extern void tty_write_unlock(struct tty_struct *tty);
416 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
417 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
418 
419 extern void tty_port_init(struct tty_port *port);
420 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
421 extern void tty_port_free_xmit_buf(struct tty_port *port);
422 extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
423 extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
424 
425 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
426 extern int tty_unregister_ldisc(int disc);
427 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
428 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
429 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
430 extern void tty_ldisc_init(struct tty_struct *tty);
431 extern void tty_ldisc_begin(void);
432 /* This last one is just for the tty layer internals and shouldn't be used elsewhere */
433 extern void tty_ldisc_enable(struct tty_struct *tty);
434 
435 
436 /* n_tty.c */
437 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
438 
439 /* tty_audit.c */
440 #ifdef CONFIG_AUDIT
441 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
442 			       size_t size);
443 extern void tty_audit_exit(void);
444 extern void tty_audit_fork(struct signal_struct *sig);
445 extern void tty_audit_push(struct tty_struct *tty);
446 extern void tty_audit_push_task(struct task_struct *tsk,
447 					uid_t loginuid, u32 sessionid);
448 #else
449 static inline void tty_audit_add_data(struct tty_struct *tty,
450 				      unsigned char *data, size_t size)
451 {
452 }
453 static inline void tty_audit_exit(void)
454 {
455 }
456 static inline void tty_audit_fork(struct signal_struct *sig)
457 {
458 }
459 static inline void tty_audit_push(struct tty_struct *tty)
460 {
461 }
462 static inline void tty_audit_push_task(struct task_struct *tsk,
463 					uid_t loginuid, u32 sessionid)
464 {
465 }
466 #endif
467 
468 /* tty_ioctl.c */
469 extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
470 		       unsigned int cmd, unsigned long arg);
471 
472 /* serial.c */
473 
474 extern void serial_console_init(void);
475 
476 /* pcxx.c */
477 
478 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
479 
480 /* printk.c */
481 
482 extern void console_print(const char *);
483 
484 /* vt.c */
485 
486 extern int vt_ioctl(struct tty_struct *tty, struct file *file,
487 		    unsigned int cmd, unsigned long arg);
488 
489 #endif /* __KERNEL__ */
490 #endif
491