xref: /linux-6.15/include/linux/tty.h (revision 2b8232ce)
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		17
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 <[email protected]> */
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 
48 /*
49  * This character is the same as _POSIX_VDISABLE: it cannot be used as
50  * a c_cc[] character, but indicates that a particular special character
51  * isn't in use (eg VINTR has no character etc)
52  */
53 #define __DISABLED_CHAR '\0'
54 
55 /*
56  * This is the flip buffer used for the tty driver.  The buffer is
57  * located in the tty structure, and is used as a high speed interface
58  * between the tty driver and the tty line discipline.
59  */
60 #define TTY_FLIPBUF_SIZE 512
61 
62 struct tty_buffer {
63 	struct tty_buffer *next;
64 	char *char_buf_ptr;
65 	unsigned char *flag_buf_ptr;
66 	int used;
67 	int size;
68 	int commit;
69 	int read;
70 	/* Data points here */
71 	unsigned long data[0];
72 };
73 
74 struct tty_bufhead {
75 	struct delayed_work work;
76 	struct semaphore pty_sem;
77 	spinlock_t lock;
78 	struct tty_buffer *head;	/* Queue head */
79 	struct tty_buffer *tail;	/* Active buffer */
80 	struct tty_buffer *free;	/* Free queue head */
81 	int memory_used;		/* Buffer space used excluding free queue */
82 };
83 /*
84  * The pty uses char_buf and flag_buf as a contiguous buffer
85  */
86 #define PTY_BUF_SIZE	4*TTY_FLIPBUF_SIZE
87 
88 /*
89  * When a break, frame error, or parity error happens, these codes are
90  * stuffed into the flags buffer.
91  */
92 #define TTY_NORMAL	0
93 #define TTY_BREAK	1
94 #define TTY_FRAME	2
95 #define TTY_PARITY	3
96 #define TTY_OVERRUN	4
97 
98 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
99 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
100 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
101 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
102 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
103 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
104 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
105 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
106 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
107 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
108 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
109 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
110 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
111 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
112 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
113 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
114 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
115 
116 #define _I_FLAG(tty,f)	((tty)->termios->c_iflag & (f))
117 #define _O_FLAG(tty,f)	((tty)->termios->c_oflag & (f))
118 #define _C_FLAG(tty,f)	((tty)->termios->c_cflag & (f))
119 #define _L_FLAG(tty,f)	((tty)->termios->c_lflag & (f))
120 
121 #define I_IGNBRK(tty)	_I_FLAG((tty),IGNBRK)
122 #define I_BRKINT(tty)	_I_FLAG((tty),BRKINT)
123 #define I_IGNPAR(tty)	_I_FLAG((tty),IGNPAR)
124 #define I_PARMRK(tty)	_I_FLAG((tty),PARMRK)
125 #define I_INPCK(tty)	_I_FLAG((tty),INPCK)
126 #define I_ISTRIP(tty)	_I_FLAG((tty),ISTRIP)
127 #define I_INLCR(tty)	_I_FLAG((tty),INLCR)
128 #define I_IGNCR(tty)	_I_FLAG((tty),IGNCR)
129 #define I_ICRNL(tty)	_I_FLAG((tty),ICRNL)
130 #define I_IUCLC(tty)	_I_FLAG((tty),IUCLC)
131 #define I_IXON(tty)	_I_FLAG((tty),IXON)
132 #define I_IXANY(tty)	_I_FLAG((tty),IXANY)
133 #define I_IXOFF(tty)	_I_FLAG((tty),IXOFF)
134 #define I_IMAXBEL(tty)	_I_FLAG((tty),IMAXBEL)
135 #define I_IUTF8(tty)	_I_FLAG((tty),IUTF8)
136 
137 #define O_OPOST(tty)	_O_FLAG((tty),OPOST)
138 #define O_OLCUC(tty)	_O_FLAG((tty),OLCUC)
139 #define O_ONLCR(tty)	_O_FLAG((tty),ONLCR)
140 #define O_OCRNL(tty)	_O_FLAG((tty),OCRNL)
141 #define O_ONOCR(tty)	_O_FLAG((tty),ONOCR)
142 #define O_ONLRET(tty)	_O_FLAG((tty),ONLRET)
143 #define O_OFILL(tty)	_O_FLAG((tty),OFILL)
144 #define O_OFDEL(tty)	_O_FLAG((tty),OFDEL)
145 #define O_NLDLY(tty)	_O_FLAG((tty),NLDLY)
146 #define O_CRDLY(tty)	_O_FLAG((tty),CRDLY)
147 #define O_TABDLY(tty)	_O_FLAG((tty),TABDLY)
148 #define O_BSDLY(tty)	_O_FLAG((tty),BSDLY)
149 #define O_VTDLY(tty)	_O_FLAG((tty),VTDLY)
150 #define O_FFDLY(tty)	_O_FLAG((tty),FFDLY)
151 
152 #define C_BAUD(tty)	_C_FLAG((tty),CBAUD)
153 #define C_CSIZE(tty)	_C_FLAG((tty),CSIZE)
154 #define C_CSTOPB(tty)	_C_FLAG((tty),CSTOPB)
155 #define C_CREAD(tty)	_C_FLAG((tty),CREAD)
156 #define C_PARENB(tty)	_C_FLAG((tty),PARENB)
157 #define C_PARODD(tty)	_C_FLAG((tty),PARODD)
158 #define C_HUPCL(tty)	_C_FLAG((tty),HUPCL)
159 #define C_CLOCAL(tty)	_C_FLAG((tty),CLOCAL)
160 #define C_CIBAUD(tty)	_C_FLAG((tty),CIBAUD)
161 #define C_CRTSCTS(tty)	_C_FLAG((tty),CRTSCTS)
162 
163 #define L_ISIG(tty)	_L_FLAG((tty),ISIG)
164 #define L_ICANON(tty)	_L_FLAG((tty),ICANON)
165 #define L_XCASE(tty)	_L_FLAG((tty),XCASE)
166 #define L_ECHO(tty)	_L_FLAG((tty),ECHO)
167 #define L_ECHOE(tty)	_L_FLAG((tty),ECHOE)
168 #define L_ECHOK(tty)	_L_FLAG((tty),ECHOK)
169 #define L_ECHONL(tty)	_L_FLAG((tty),ECHONL)
170 #define L_NOFLSH(tty)	_L_FLAG((tty),NOFLSH)
171 #define L_TOSTOP(tty)	_L_FLAG((tty),TOSTOP)
172 #define L_ECHOCTL(tty)	_L_FLAG((tty),ECHOCTL)
173 #define L_ECHOPRT(tty)	_L_FLAG((tty),ECHOPRT)
174 #define L_ECHOKE(tty)	_L_FLAG((tty),ECHOKE)
175 #define L_FLUSHO(tty)	_L_FLAG((tty),FLUSHO)
176 #define L_PENDIN(tty)	_L_FLAG((tty),PENDIN)
177 #define L_IEXTEN(tty)	_L_FLAG((tty),IEXTEN)
178 
179 struct device;
180 struct signal_struct;
181 /*
182  * Where all of the state associated with a tty is kept while the tty
183  * is open.  Since the termios state should be kept even if the tty
184  * has been closed --- for things like the baud rate, etc --- it is
185  * not stored here, but rather a pointer to the real state is stored
186  * here.  Possible the winsize structure should have the same
187  * treatment, but (1) the default 80x24 is usually right and (2) it's
188  * most often used by a windowing system, which will set the correct
189  * size each time the window is created or resized anyway.
190  * 						- TYT, 9/14/92
191  */
192 struct tty_struct {
193 	int	magic;
194 	struct tty_driver *driver;
195 	int index;
196 	struct tty_ldisc ldisc;
197 	struct mutex termios_mutex;
198 	struct ktermios *termios, *termios_locked;
199 	char name[64];
200 	struct pid *pgrp;
201 	struct pid *session;
202 	unsigned long flags;
203 	int count;
204 	struct winsize winsize;
205 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
206 	unsigned char low_latency:1, warned:1;
207 	unsigned char ctrl_status;
208 	unsigned int receive_room;	/* Bytes free for queue */
209 
210 	struct tty_struct *link;
211 	struct fasync_struct *fasync;
212 	struct tty_bufhead buf;
213 	int alt_speed;		/* For magic substitution of 38400 bps */
214 	wait_queue_head_t write_wait;
215 	wait_queue_head_t read_wait;
216 	struct work_struct hangup_work;
217 	void *disc_data;
218 	void *driver_data;
219 	struct list_head tty_files;
220 
221 #define N_TTY_BUF_SIZE 4096
222 
223 	/*
224 	 * The following is data for the N_TTY line discipline.  For
225 	 * historical reasons, this is included in the tty structure.
226 	 */
227 	unsigned int column;
228 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
229 	unsigned char closing:1;
230 	unsigned short minimum_to_wake;
231 	unsigned long overrun_time;
232 	int num_overrun;
233 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
234 	char *read_buf;
235 	int read_head;
236 	int read_tail;
237 	int read_cnt;
238 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
239 	int canon_data;
240 	unsigned long canon_head;
241 	unsigned int canon_column;
242 	struct mutex atomic_read_lock;
243 	struct mutex atomic_write_lock;
244 	unsigned char *write_buf;
245 	int write_cnt;
246 	spinlock_t read_lock;
247 	/* If the tty has a pending do_SAK, queue it here - akpm */
248 	struct work_struct SAK_work;
249 };
250 
251 /* tty magic number */
252 #define TTY_MAGIC		0x5401
253 
254 /*
255  * These bits are used in the flags field of the tty structure.
256  *
257  * So that interrupts won't be able to mess up the queues,
258  * copy_to_cooked must be atomic with respect to itself, as must
259  * tty->write.  Thus, you must use the inline functions set_bit() and
260  * clear_bit() to make things atomic.
261  */
262 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
263 #define TTY_IO_ERROR 		1	/* Canse an I/O error (may be no ldisc too) */
264 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
265 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
266 #define TTY_DEBUG 		4	/* Debugging */
267 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
268 #define TTY_PUSH 		6	/* n_tty private */
269 #define TTY_CLOSING 		7	/* ->close() in progress */
270 #define TTY_LDISC 		9	/* Line discipline attached */
271 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
272 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
273 #define TTY_PTY_LOCK 		16	/* pty private */
274 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
275 #define TTY_HUPPED 		18	/* Post driver->hangup() */
276 #define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
277 #define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
278 
279 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
280 
281 extern void tty_write_flush(struct tty_struct *);
282 
283 extern struct ktermios tty_std_termios;
284 
285 extern int kmsg_redirect;
286 
287 extern void console_init(void);
288 extern int vcs_init(void);
289 
290 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
291 			      const char *routine);
292 extern char *tty_name(struct tty_struct *tty, char *buf);
293 extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
294 extern int tty_check_change(struct tty_struct * tty);
295 extern void stop_tty(struct tty_struct * tty);
296 extern void start_tty(struct tty_struct * tty);
297 extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
298 extern int tty_unregister_ldisc(int disc);
299 extern int tty_register_driver(struct tty_driver *driver);
300 extern int tty_unregister_driver(struct tty_driver *driver);
301 extern struct device *tty_register_device(struct tty_driver *driver,
302 					  unsigned index, struct device *dev);
303 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
304 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
305 			     int buflen);
306 extern void tty_write_message(struct tty_struct *tty, char *msg);
307 
308 extern int is_current_pgrp_orphaned(void);
309 extern int is_ignored(int sig);
310 extern int tty_signal(int sig, struct tty_struct *tty);
311 extern void tty_hangup(struct tty_struct * tty);
312 extern void tty_vhangup(struct tty_struct * tty);
313 extern void tty_unhangup(struct file *filp);
314 extern int tty_hung_up_p(struct file * filp);
315 extern int is_tty(struct file *filp);
316 extern void do_SAK(struct tty_struct *tty);
317 extern void __do_SAK(struct tty_struct *tty);
318 extern void disassociate_ctty(int priv);
319 extern void no_tty(void);
320 extern void tty_flip_buffer_push(struct tty_struct *tty);
321 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
322 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
323 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
324 
325 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
326 extern void tty_ldisc_deref(struct tty_ldisc *);
327 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
328 
329 extern struct tty_ldisc *tty_ldisc_get(int);
330 extern void tty_ldisc_put(int);
331 
332 extern void tty_wakeup(struct tty_struct *tty);
333 extern void tty_ldisc_flush(struct tty_struct *tty);
334 
335 extern int tty_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
336 		     unsigned long arg);
337 
338 extern dev_t tty_devnum(struct tty_struct *tty);
339 extern void proc_clear_tty(struct task_struct *p);
340 extern struct tty_struct *get_current_tty(void);
341 
342 extern struct mutex tty_mutex;
343 
344 extern void tty_write_unlock(struct tty_struct *tty);
345 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
346 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
347 
348 
349 
350 /* n_tty.c */
351 extern struct tty_ldisc tty_ldisc_N_TTY;
352 
353 /* tty_audit.c */
354 #ifdef CONFIG_AUDIT
355 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
356 			       size_t size);
357 extern void tty_audit_exit(void);
358 extern void tty_audit_fork(struct signal_struct *sig);
359 extern void tty_audit_push(struct tty_struct *tty);
360 extern void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid);
361 extern void tty_audit_opening(void);
362 #else
363 static inline void tty_audit_add_data(struct tty_struct *tty,
364 				      unsigned char *data, size_t size)
365 {
366 }
367 static inline void tty_audit_exit(void)
368 {
369 }
370 static inline void tty_audit_fork(struct signal_struct *sig)
371 {
372 }
373 static inline void tty_audit_push(struct tty_struct *tty)
374 {
375 }
376 static inline void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid)
377 {
378 }
379 static inline void tty_audit_opening(void)
380 {
381 }
382 #endif
383 
384 /* tty_ioctl.c */
385 extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
386 		       unsigned int cmd, unsigned long arg);
387 
388 /* serial.c */
389 
390 extern void serial_console_init(void);
391 
392 /* pcxx.c */
393 
394 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
395 
396 /* printk.c */
397 
398 extern void console_print(const char *);
399 
400 /* vt.c */
401 
402 extern int vt_ioctl(struct tty_struct *tty, struct file * file,
403 		    unsigned int cmd, unsigned long arg);
404 
405 #endif /* __KERNEL__ */
406 #endif
407