xref: /linux-6.15/include/linux/tty.h (revision 2d6ffcca)
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		18
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 
49 /*
50  * This character is the same as _POSIX_VDISABLE: it cannot be used as
51  * a c_cc[] character, but indicates that a particular special character
52  * isn't in use (eg VINTR has no character etc)
53  */
54 #define __DISABLED_CHAR '\0'
55 
56 struct tty_buffer {
57 	struct tty_buffer *next;
58 	char *char_buf_ptr;
59 	unsigned char *flag_buf_ptr;
60 	int used;
61 	int size;
62 	int commit;
63 	int read;
64 	/* Data points here */
65 	unsigned long data[0];
66 };
67 
68 struct tty_bufhead {
69 	struct delayed_work work;
70 	spinlock_t lock;
71 	struct tty_buffer *head;	/* Queue head */
72 	struct tty_buffer *tail;	/* Active buffer */
73 	struct tty_buffer *free;	/* Free queue head */
74 	int memory_used;		/* Buffer space used excluding
75 								free queue */
76 };
77 /*
78  * When a break, frame error, or parity error happens, these codes are
79  * stuffed into the flags buffer.
80  */
81 #define TTY_NORMAL	0
82 #define TTY_BREAK	1
83 #define TTY_FRAME	2
84 #define TTY_PARITY	3
85 #define TTY_OVERRUN	4
86 
87 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
88 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
89 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
90 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
91 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
92 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
93 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
94 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
95 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
96 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
97 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
98 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
99 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
100 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
101 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
102 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
103 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
104 
105 #define _I_FLAG(tty, f)	((tty)->termios->c_iflag & (f))
106 #define _O_FLAG(tty, f)	((tty)->termios->c_oflag & (f))
107 #define _C_FLAG(tty, f)	((tty)->termios->c_cflag & (f))
108 #define _L_FLAG(tty, f)	((tty)->termios->c_lflag & (f))
109 
110 #define I_IGNBRK(tty)	_I_FLAG((tty), IGNBRK)
111 #define I_BRKINT(tty)	_I_FLAG((tty), BRKINT)
112 #define I_IGNPAR(tty)	_I_FLAG((tty), IGNPAR)
113 #define I_PARMRK(tty)	_I_FLAG((tty), PARMRK)
114 #define I_INPCK(tty)	_I_FLAG((tty), INPCK)
115 #define I_ISTRIP(tty)	_I_FLAG((tty), ISTRIP)
116 #define I_INLCR(tty)	_I_FLAG((tty), INLCR)
117 #define I_IGNCR(tty)	_I_FLAG((tty), IGNCR)
118 #define I_ICRNL(tty)	_I_FLAG((tty), ICRNL)
119 #define I_IUCLC(tty)	_I_FLAG((tty), IUCLC)
120 #define I_IXON(tty)	_I_FLAG((tty), IXON)
121 #define I_IXANY(tty)	_I_FLAG((tty), IXANY)
122 #define I_IXOFF(tty)	_I_FLAG((tty), IXOFF)
123 #define I_IMAXBEL(tty)	_I_FLAG((tty), IMAXBEL)
124 #define I_IUTF8(tty)	_I_FLAG((tty), IUTF8)
125 
126 #define O_OPOST(tty)	_O_FLAG((tty), OPOST)
127 #define O_OLCUC(tty)	_O_FLAG((tty), OLCUC)
128 #define O_ONLCR(tty)	_O_FLAG((tty), ONLCR)
129 #define O_OCRNL(tty)	_O_FLAG((tty), OCRNL)
130 #define O_ONOCR(tty)	_O_FLAG((tty), ONOCR)
131 #define O_ONLRET(tty)	_O_FLAG((tty), ONLRET)
132 #define O_OFILL(tty)	_O_FLAG((tty), OFILL)
133 #define O_OFDEL(tty)	_O_FLAG((tty), OFDEL)
134 #define O_NLDLY(tty)	_O_FLAG((tty), NLDLY)
135 #define O_CRDLY(tty)	_O_FLAG((tty), CRDLY)
136 #define O_TABDLY(tty)	_O_FLAG((tty), TABDLY)
137 #define O_BSDLY(tty)	_O_FLAG((tty), BSDLY)
138 #define O_VTDLY(tty)	_O_FLAG((tty), VTDLY)
139 #define O_FFDLY(tty)	_O_FLAG((tty), FFDLY)
140 
141 #define C_BAUD(tty)	_C_FLAG((tty), CBAUD)
142 #define C_CSIZE(tty)	_C_FLAG((tty), CSIZE)
143 #define C_CSTOPB(tty)	_C_FLAG((tty), CSTOPB)
144 #define C_CREAD(tty)	_C_FLAG((tty), CREAD)
145 #define C_PARENB(tty)	_C_FLAG((tty), PARENB)
146 #define C_PARODD(tty)	_C_FLAG((tty), PARODD)
147 #define C_HUPCL(tty)	_C_FLAG((tty), HUPCL)
148 #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
149 #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
150 #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
151 
152 #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
153 #define L_ICANON(tty)	_L_FLAG((tty), ICANON)
154 #define L_XCASE(tty)	_L_FLAG((tty), XCASE)
155 #define L_ECHO(tty)	_L_FLAG((tty), ECHO)
156 #define L_ECHOE(tty)	_L_FLAG((tty), ECHOE)
157 #define L_ECHOK(tty)	_L_FLAG((tty), ECHOK)
158 #define L_ECHONL(tty)	_L_FLAG((tty), ECHONL)
159 #define L_NOFLSH(tty)	_L_FLAG((tty), NOFLSH)
160 #define L_TOSTOP(tty)	_L_FLAG((tty), TOSTOP)
161 #define L_ECHOCTL(tty)	_L_FLAG((tty), ECHOCTL)
162 #define L_ECHOPRT(tty)	_L_FLAG((tty), ECHOPRT)
163 #define L_ECHOKE(tty)	_L_FLAG((tty), ECHOKE)
164 #define L_FLUSHO(tty)	_L_FLAG((tty), FLUSHO)
165 #define L_PENDIN(tty)	_L_FLAG((tty), PENDIN)
166 #define L_IEXTEN(tty)	_L_FLAG((tty), IEXTEN)
167 
168 struct device;
169 struct signal_struct;
170 
171 /*
172  * Port level information. Each device keeps its own port level information
173  * so provide a common structure for those ports wanting to use common support
174  * routines.
175  *
176  * The tty port has a different lifetime to the tty so must be kept apart.
177  * In addition be careful as tty -> port mappings are valid for the life
178  * of the tty object but in many cases port -> tty mappings are valid only
179  * until a hangup so don't use the wrong path.
180  */
181 
182 struct tty_port {
183 	struct tty_struct	*tty;		/* Back pointer */
184 	int			blocked_open;	/* Waiting to open */
185 	int			count;		/* Usage count */
186 	wait_queue_head_t	open_wait;	/* Open waiters */
187 	wait_queue_head_t	close_wait;	/* Close waiters */
188 	unsigned long		flags;		/* TTY flags ASY_*/
189 	struct mutex		mutex;		/* Locking */
190 	unsigned char		*xmit_buf;	/* Optional buffer */
191 	int			close_delay;	/* Close port delay */
192 	int			closing_wait;	/* Delay for output */
193 };
194 
195 /*
196  * Where all of the state associated with a tty is kept while the tty
197  * is open.  Since the termios state should be kept even if the tty
198  * has been closed --- for things like the baud rate, etc --- it is
199  * not stored here, but rather a pointer to the real state is stored
200  * here.  Possible the winsize structure should have the same
201  * treatment, but (1) the default 80x24 is usually right and (2) it's
202  * most often used by a windowing system, which will set the correct
203  * size each time the window is created or resized anyway.
204  * 						- TYT, 9/14/92
205  */
206 
207 struct tty_operations;
208 
209 struct tty_struct {
210 	int	magic;
211 	struct tty_driver *driver;
212 	const struct tty_operations *ops;
213 	int index;
214 	/* The ldisc objects are protected by tty_ldisc_lock at the moment */
215 	struct tty_ldisc ldisc;
216 	struct mutex termios_mutex;
217 	spinlock_t ctrl_lock;
218 	/* Termios values are protected by the termios mutex */
219 	struct ktermios *termios, *termios_locked;
220 	char name[64];
221 	struct pid *pgrp;		/* Protected by ctrl lock */
222 	struct pid *session;
223 	unsigned long flags;
224 	int count;
225 	struct winsize winsize;		/* termios mutex */
226 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
227 	unsigned char low_latency:1, warned:1;
228 	unsigned char ctrl_status;	/* ctrl_lock */
229 	unsigned int receive_room;	/* Bytes free for queue */
230 
231 	struct tty_struct *link;
232 	struct fasync_struct *fasync;
233 	struct tty_bufhead buf;		/* Locked internally */
234 	int alt_speed;		/* For magic substitution of 38400 bps */
235 	wait_queue_head_t write_wait;
236 	wait_queue_head_t read_wait;
237 	struct work_struct hangup_work;
238 	void *disc_data;
239 	void *driver_data;
240 	struct list_head tty_files;
241 
242 #define N_TTY_BUF_SIZE 4096
243 
244 	/*
245 	 * The following is data for the N_TTY line discipline.  For
246 	 * historical reasons, this is included in the tty structure.
247 	 * Mostly locked by the BKL.
248 	 */
249 	unsigned int column;
250 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
251 	unsigned char closing:1;
252 	unsigned short minimum_to_wake;
253 	unsigned long overrun_time;
254 	int num_overrun;
255 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
256 	char *read_buf;
257 	int read_head;
258 	int read_tail;
259 	int read_cnt;
260 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
261 	int canon_data;
262 	unsigned long canon_head;
263 	unsigned int canon_column;
264 	struct mutex atomic_read_lock;
265 	struct mutex atomic_write_lock;
266 	unsigned char *write_buf;
267 	int write_cnt;
268 	spinlock_t read_lock;
269 	/* If the tty has a pending do_SAK, queue it here - akpm */
270 	struct work_struct SAK_work;
271 	struct tty_port *port;
272 };
273 
274 /* tty magic number */
275 #define TTY_MAGIC		0x5401
276 
277 /*
278  * These bits are used in the flags field of the tty structure.
279  *
280  * So that interrupts won't be able to mess up the queues,
281  * copy_to_cooked must be atomic with respect to itself, as must
282  * tty->write.  Thus, you must use the inline functions set_bit() and
283  * clear_bit() to make things atomic.
284  */
285 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
286 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
287 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
288 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
289 #define TTY_DEBUG 		4	/* Debugging */
290 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
291 #define TTY_PUSH 		6	/* n_tty private */
292 #define TTY_CLOSING 		7	/* ->close() in progress */
293 #define TTY_LDISC 		9	/* Line discipline attached */
294 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
295 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
296 #define TTY_PTY_LOCK 		16	/* pty private */
297 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
298 #define TTY_HUPPED 		18	/* Post driver->hangup() */
299 #define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
300 #define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
301 
302 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
303 
304 extern void tty_write_flush(struct tty_struct *);
305 
306 extern struct ktermios tty_std_termios;
307 
308 extern int kmsg_redirect;
309 
310 extern void console_init(void);
311 extern int vcs_init(void);
312 
313 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
314 			      const char *routine);
315 extern char *tty_name(struct tty_struct *tty, char *buf);
316 extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
317 extern int tty_check_change(struct tty_struct *tty);
318 extern void stop_tty(struct tty_struct *tty);
319 extern void start_tty(struct tty_struct *tty);
320 extern int tty_register_driver(struct tty_driver *driver);
321 extern int tty_unregister_driver(struct tty_driver *driver);
322 extern struct device *tty_register_device(struct tty_driver *driver,
323 					  unsigned index, struct device *dev);
324 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
325 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
326 			     int buflen);
327 extern void tty_write_message(struct tty_struct *tty, char *msg);
328 extern int tty_put_char(struct tty_struct *tty, unsigned char c);
329 extern int tty_chars_in_buffer(struct tty_struct *tty);
330 extern int tty_write_room(struct tty_struct *tty);
331 extern void tty_driver_flush_buffer(struct tty_struct *tty);
332 extern void tty_throttle(struct tty_struct *tty);
333 extern void tty_unthrottle(struct tty_struct *tty);
334 
335 extern int is_current_pgrp_orphaned(void);
336 extern struct pid *tty_get_pgrp(struct tty_struct *tty);
337 extern int is_ignored(int sig);
338 extern int tty_signal(int sig, struct tty_struct *tty);
339 extern void tty_hangup(struct tty_struct *tty);
340 extern void tty_vhangup(struct tty_struct *tty);
341 extern void tty_unhangup(struct file *filp);
342 extern int tty_hung_up_p(struct file *filp);
343 extern void do_SAK(struct tty_struct *tty);
344 extern void __do_SAK(struct tty_struct *tty);
345 extern void disassociate_ctty(int priv);
346 extern void no_tty(void);
347 extern void tty_flip_buffer_push(struct tty_struct *tty);
348 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
349 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
350 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
351 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
352 						speed_t ibaud, speed_t obaud);
353 extern void tty_encode_baud_rate(struct tty_struct *tty,
354 						speed_t ibaud, speed_t obaud);
355 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
356 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
357 
358 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
359 extern void tty_ldisc_deref(struct tty_ldisc *);
360 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
361 extern const struct file_operations tty_ldiscs_proc_fops;
362 
363 extern void tty_wakeup(struct tty_struct *tty);
364 extern void tty_ldisc_flush(struct tty_struct *tty);
365 
366 extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
367 extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
368 			unsigned int cmd, unsigned long arg);
369 extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
370 extern dev_t tty_devnum(struct tty_struct *tty);
371 extern void proc_clear_tty(struct task_struct *p);
372 extern struct tty_struct *get_current_tty(void);
373 
374 extern struct mutex tty_mutex;
375 
376 extern void tty_write_unlock(struct tty_struct *tty);
377 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
378 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
379 
380 extern void tty_port_init(struct tty_port *port);
381 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
382 extern void tty_port_free_xmit_buf(struct tty_port *port);
383 
384 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
385 extern int tty_unregister_ldisc(int disc);
386 extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
387 extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
388 extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
389 extern void tty_ldisc_init(struct tty_struct *tty);
390 extern void tty_ldisc_begin(void);
391 /* This last one is just for the tty layer internals and shouldn't be used elsewhere */
392 extern void tty_ldisc_enable(struct tty_struct *tty);
393 
394 
395 /* n_tty.c */
396 extern struct tty_ldisc_ops tty_ldisc_N_TTY;
397 
398 /* tty_audit.c */
399 #ifdef CONFIG_AUDIT
400 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
401 			       size_t size);
402 extern void tty_audit_exit(void);
403 extern void tty_audit_fork(struct signal_struct *sig);
404 extern void tty_audit_push(struct tty_struct *tty);
405 extern void tty_audit_push_task(struct task_struct *tsk,
406 					uid_t loginuid, u32 sessionid);
407 #else
408 static inline void tty_audit_add_data(struct tty_struct *tty,
409 				      unsigned char *data, size_t size)
410 {
411 }
412 static inline void tty_audit_exit(void)
413 {
414 }
415 static inline void tty_audit_fork(struct signal_struct *sig)
416 {
417 }
418 static inline void tty_audit_push(struct tty_struct *tty)
419 {
420 }
421 static inline void tty_audit_push_task(struct task_struct *tsk,
422 					uid_t loginuid, u32 sessionid)
423 {
424 }
425 #endif
426 
427 /* tty_ioctl.c */
428 extern int n_tty_ioctl(struct tty_struct *tty, struct file *file,
429 		       unsigned int cmd, unsigned long arg);
430 
431 /* serial.c */
432 
433 extern void serial_console_init(void);
434 
435 /* pcxx.c */
436 
437 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
438 
439 /* printk.c */
440 
441 extern void console_print(const char *);
442 
443 /* vt.c */
444 
445 extern int vt_ioctl(struct tty_struct *tty, struct file *file,
446 		    unsigned int cmd, unsigned long arg);
447 
448 #endif /* __KERNEL__ */
449 #endif
450