xref: /linux-6.15/include/linux/tty.h (revision 2a677896)
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_PTYS	CONFIG_LEGACY_PTY_COUNT   /* Number of legacy ptys */
25 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
26 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
27 #define NR_LDISCS		17
28 
29 /* line disciplines */
30 #define N_TTY		0
31 #define N_SLIP		1
32 #define N_MOUSE		2
33 #define N_PPP		3
34 #define N_STRIP		4
35 #define N_AX25		5
36 #define N_X25		6	/* X.25 async */
37 #define N_6PACK		7
38 #define N_MASC		8	/* Reserved for Mobitex module <[email protected]> */
39 #define N_R3964		9	/* Reserved for Simatic R3964 module */
40 #define N_PROFIBUS_FDL	10	/* Reserved for Profibus <[email protected]> */
41 #define N_IRDA		11	/* Linux IrDa - http://irda.sourceforge.net/ */
42 #define N_SMSBLOCK	12	/* SMS block mode - for talking to GSM data */
43 				/* cards about SMS messages */
44 #define N_HDLC		13	/* synchronous HDLC */
45 #define N_SYNC_PPP	14	/* synchronous PPP */
46 #define N_HCI		15	/* Bluetooth HCI UART */
47 #define N_GIGASET_M101	16	/* Siemens Gigaset M101 serial DECT adapter */
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 /*
57  * This is the flip buffer used for the tty driver.  The buffer is
58  * located in the tty structure, and is used as a high speed interface
59  * between the tty driver and the tty line discipline.
60  */
61 #define TTY_FLIPBUF_SIZE 512
62 
63 struct tty_buffer {
64 	struct tty_buffer *next;
65 	char *char_buf_ptr;
66 	unsigned char *flag_buf_ptr;
67 	int used;
68 	int size;
69 	int commit;
70 	int read;
71 	/* Data points here */
72 	unsigned long data[0];
73 };
74 
75 struct tty_bufhead {
76 	struct delayed_work work;
77 	struct semaphore pty_sem;
78 	spinlock_t lock;
79 	struct tty_buffer *head;	/* Queue head */
80 	struct tty_buffer *tail;	/* Active buffer */
81 	struct tty_buffer *free;	/* Free queue head */
82 	int memory_used;		/* Buffer space used excluding free queue */
83 };
84 /*
85  * The pty uses char_buf and flag_buf as a contiguous buffer
86  */
87 #define PTY_BUF_SIZE	4*TTY_FLIPBUF_SIZE
88 
89 /*
90  * When a break, frame error, or parity error happens, these codes are
91  * stuffed into the flags buffer.
92  */
93 #define TTY_NORMAL	0
94 #define TTY_BREAK	1
95 #define TTY_FRAME	2
96 #define TTY_PARITY	3
97 #define TTY_OVERRUN	4
98 
99 #define INTR_CHAR(tty) ((tty)->termios->c_cc[VINTR])
100 #define QUIT_CHAR(tty) ((tty)->termios->c_cc[VQUIT])
101 #define ERASE_CHAR(tty) ((tty)->termios->c_cc[VERASE])
102 #define KILL_CHAR(tty) ((tty)->termios->c_cc[VKILL])
103 #define EOF_CHAR(tty) ((tty)->termios->c_cc[VEOF])
104 #define TIME_CHAR(tty) ((tty)->termios->c_cc[VTIME])
105 #define MIN_CHAR(tty) ((tty)->termios->c_cc[VMIN])
106 #define SWTC_CHAR(tty) ((tty)->termios->c_cc[VSWTC])
107 #define START_CHAR(tty) ((tty)->termios->c_cc[VSTART])
108 #define STOP_CHAR(tty) ((tty)->termios->c_cc[VSTOP])
109 #define SUSP_CHAR(tty) ((tty)->termios->c_cc[VSUSP])
110 #define EOL_CHAR(tty) ((tty)->termios->c_cc[VEOL])
111 #define REPRINT_CHAR(tty) ((tty)->termios->c_cc[VREPRINT])
112 #define DISCARD_CHAR(tty) ((tty)->termios->c_cc[VDISCARD])
113 #define WERASE_CHAR(tty) ((tty)->termios->c_cc[VWERASE])
114 #define LNEXT_CHAR(tty)	((tty)->termios->c_cc[VLNEXT])
115 #define EOL2_CHAR(tty) ((tty)->termios->c_cc[VEOL2])
116 
117 #define _I_FLAG(tty,f)	((tty)->termios->c_iflag & (f))
118 #define _O_FLAG(tty,f)	((tty)->termios->c_oflag & (f))
119 #define _C_FLAG(tty,f)	((tty)->termios->c_cflag & (f))
120 #define _L_FLAG(tty,f)	((tty)->termios->c_lflag & (f))
121 
122 #define I_IGNBRK(tty)	_I_FLAG((tty),IGNBRK)
123 #define I_BRKINT(tty)	_I_FLAG((tty),BRKINT)
124 #define I_IGNPAR(tty)	_I_FLAG((tty),IGNPAR)
125 #define I_PARMRK(tty)	_I_FLAG((tty),PARMRK)
126 #define I_INPCK(tty)	_I_FLAG((tty),INPCK)
127 #define I_ISTRIP(tty)	_I_FLAG((tty),ISTRIP)
128 #define I_INLCR(tty)	_I_FLAG((tty),INLCR)
129 #define I_IGNCR(tty)	_I_FLAG((tty),IGNCR)
130 #define I_ICRNL(tty)	_I_FLAG((tty),ICRNL)
131 #define I_IUCLC(tty)	_I_FLAG((tty),IUCLC)
132 #define I_IXON(tty)	_I_FLAG((tty),IXON)
133 #define I_IXANY(tty)	_I_FLAG((tty),IXANY)
134 #define I_IXOFF(tty)	_I_FLAG((tty),IXOFF)
135 #define I_IMAXBEL(tty)	_I_FLAG((tty),IMAXBEL)
136 #define I_IUTF8(tty)	_I_FLAG((tty),IUTF8)
137 
138 #define O_OPOST(tty)	_O_FLAG((tty),OPOST)
139 #define O_OLCUC(tty)	_O_FLAG((tty),OLCUC)
140 #define O_ONLCR(tty)	_O_FLAG((tty),ONLCR)
141 #define O_OCRNL(tty)	_O_FLAG((tty),OCRNL)
142 #define O_ONOCR(tty)	_O_FLAG((tty),ONOCR)
143 #define O_ONLRET(tty)	_O_FLAG((tty),ONLRET)
144 #define O_OFILL(tty)	_O_FLAG((tty),OFILL)
145 #define O_OFDEL(tty)	_O_FLAG((tty),OFDEL)
146 #define O_NLDLY(tty)	_O_FLAG((tty),NLDLY)
147 #define O_CRDLY(tty)	_O_FLAG((tty),CRDLY)
148 #define O_TABDLY(tty)	_O_FLAG((tty),TABDLY)
149 #define O_BSDLY(tty)	_O_FLAG((tty),BSDLY)
150 #define O_VTDLY(tty)	_O_FLAG((tty),VTDLY)
151 #define O_FFDLY(tty)	_O_FLAG((tty),FFDLY)
152 
153 #define C_BAUD(tty)	_C_FLAG((tty),CBAUD)
154 #define C_CSIZE(tty)	_C_FLAG((tty),CSIZE)
155 #define C_CSTOPB(tty)	_C_FLAG((tty),CSTOPB)
156 #define C_CREAD(tty)	_C_FLAG((tty),CREAD)
157 #define C_PARENB(tty)	_C_FLAG((tty),PARENB)
158 #define C_PARODD(tty)	_C_FLAG((tty),PARODD)
159 #define C_HUPCL(tty)	_C_FLAG((tty),HUPCL)
160 #define C_CLOCAL(tty)	_C_FLAG((tty),CLOCAL)
161 #define C_CIBAUD(tty)	_C_FLAG((tty),CIBAUD)
162 #define C_CRTSCTS(tty)	_C_FLAG((tty),CRTSCTS)
163 
164 #define L_ISIG(tty)	_L_FLAG((tty),ISIG)
165 #define L_ICANON(tty)	_L_FLAG((tty),ICANON)
166 #define L_XCASE(tty)	_L_FLAG((tty),XCASE)
167 #define L_ECHO(tty)	_L_FLAG((tty),ECHO)
168 #define L_ECHOE(tty)	_L_FLAG((tty),ECHOE)
169 #define L_ECHOK(tty)	_L_FLAG((tty),ECHOK)
170 #define L_ECHONL(tty)	_L_FLAG((tty),ECHONL)
171 #define L_NOFLSH(tty)	_L_FLAG((tty),NOFLSH)
172 #define L_TOSTOP(tty)	_L_FLAG((tty),TOSTOP)
173 #define L_ECHOCTL(tty)	_L_FLAG((tty),ECHOCTL)
174 #define L_ECHOPRT(tty)	_L_FLAG((tty),ECHOPRT)
175 #define L_ECHOKE(tty)	_L_FLAG((tty),ECHOKE)
176 #define L_FLUSHO(tty)	_L_FLAG((tty),FLUSHO)
177 #define L_PENDIN(tty)	_L_FLAG((tty),PENDIN)
178 #define L_IEXTEN(tty)	_L_FLAG((tty),IEXTEN)
179 
180 struct device;
181 struct signal_struct;
182 /*
183  * Where all of the state associated with a tty is kept while the tty
184  * is open.  Since the termios state should be kept even if the tty
185  * has been closed --- for things like the baud rate, etc --- it is
186  * not stored here, but rather a pointer to the real state is stored
187  * here.  Possible the winsize structure should have the same
188  * treatment, but (1) the default 80x24 is usually right and (2) it's
189  * most often used by a windowing system, which will set the correct
190  * size each time the window is created or resized anyway.
191  * 						- TYT, 9/14/92
192  */
193 struct tty_struct {
194 	int	magic;
195 	struct tty_driver *driver;
196 	int index;
197 	struct tty_ldisc ldisc;
198 	struct mutex termios_mutex;
199 	struct ktermios *termios, *termios_locked;
200 	char name[64];
201 	struct pid *pgrp;
202 	struct pid *session;
203 	unsigned long flags;
204 	int count;
205 	struct winsize winsize;
206 	unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
207 	unsigned char low_latency:1, warned:1;
208 	unsigned char ctrl_status;
209 	unsigned int receive_room;	/* Bytes free for queue */
210 
211 	struct tty_struct *link;
212 	struct fasync_struct *fasync;
213 	struct tty_bufhead buf;
214 	int alt_speed;		/* For magic substitution of 38400 bps */
215 	wait_queue_head_t write_wait;
216 	wait_queue_head_t read_wait;
217 	struct work_struct hangup_work;
218 	void *disc_data;
219 	void *driver_data;
220 	struct list_head tty_files;
221 
222 #define N_TTY_BUF_SIZE 4096
223 
224 	/*
225 	 * The following is data for the N_TTY line discipline.  For
226 	 * historical reasons, this is included in the tty structure.
227 	 */
228 	unsigned int column;
229 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
230 	unsigned char closing:1;
231 	unsigned short minimum_to_wake;
232 	unsigned long overrun_time;
233 	int num_overrun;
234 	unsigned long process_char_map[256/(8*sizeof(unsigned long))];
235 	char *read_buf;
236 	int read_head;
237 	int read_tail;
238 	int read_cnt;
239 	unsigned long read_flags[N_TTY_BUF_SIZE/(8*sizeof(unsigned long))];
240 	int canon_data;
241 	unsigned long canon_head;
242 	unsigned int canon_column;
243 	struct mutex atomic_read_lock;
244 	struct mutex atomic_write_lock;
245 	unsigned char *write_buf;
246 	int write_cnt;
247 	spinlock_t read_lock;
248 	/* If the tty has a pending do_SAK, queue it here - akpm */
249 	struct work_struct SAK_work;
250 };
251 
252 /* tty magic number */
253 #define TTY_MAGIC		0x5401
254 
255 /*
256  * These bits are used in the flags field of the tty structure.
257  *
258  * So that interrupts won't be able to mess up the queues,
259  * copy_to_cooked must be atomic with respect to itself, as must
260  * tty->write.  Thus, you must use the inline functions set_bit() and
261  * clear_bit() to make things atomic.
262  */
263 #define TTY_THROTTLED 		0	/* Call unthrottle() at threshold min */
264 #define TTY_IO_ERROR 		1	/* Canse an I/O error (may be no ldisc too) */
265 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
266 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
267 #define TTY_DEBUG 		4	/* Debugging */
268 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
269 #define TTY_PUSH 		6	/* n_tty private */
270 #define TTY_CLOSING 		7	/* ->close() in progress */
271 #define TTY_LDISC 		9	/* Line discipline attached */
272 #define TTY_HW_COOK_OUT 	14	/* Hardware can do output cooking */
273 #define TTY_HW_COOK_IN 		15	/* Hardware can do input cooking */
274 #define TTY_PTY_LOCK 		16	/* pty private */
275 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
276 #define TTY_HUPPED 		18	/* Post driver->hangup() */
277 #define TTY_FLUSHING		19	/* Flushing to ldisc in progress */
278 #define TTY_FLUSHPENDING	20	/* Queued buffer flush pending */
279 
280 #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
281 
282 extern void tty_write_flush(struct tty_struct *);
283 
284 extern struct ktermios tty_std_termios;
285 
286 extern int kmsg_redirect;
287 
288 extern void console_init(void);
289 extern int vcs_init(void);
290 
291 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
292 			      const char *routine);
293 extern char *tty_name(struct tty_struct *tty, char *buf);
294 extern void tty_wait_until_sent(struct tty_struct * tty, long timeout);
295 extern int tty_check_change(struct tty_struct * tty);
296 extern void stop_tty(struct tty_struct * tty);
297 extern void start_tty(struct tty_struct * tty);
298 extern int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc);
299 extern int tty_unregister_ldisc(int disc);
300 extern int tty_register_driver(struct tty_driver *driver);
301 extern int tty_unregister_driver(struct tty_driver *driver);
302 extern struct device *tty_register_device(struct tty_driver *driver,
303 					  unsigned index, struct device *dev);
304 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
305 extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
306 			     int buflen);
307 extern void tty_write_message(struct tty_struct *tty, char *msg);
308 
309 extern int is_current_pgrp_orphaned(void);
310 extern int is_ignored(int sig);
311 extern int tty_signal(int sig, struct tty_struct *tty);
312 extern void tty_hangup(struct tty_struct * tty);
313 extern void tty_vhangup(struct tty_struct * tty);
314 extern void tty_unhangup(struct file *filp);
315 extern int tty_hung_up_p(struct file * filp);
316 extern int is_tty(struct file *filp);
317 extern void do_SAK(struct tty_struct *tty);
318 extern void __do_SAK(struct tty_struct *tty);
319 extern void disassociate_ctty(int priv);
320 extern void no_tty(void);
321 extern void tty_flip_buffer_push(struct tty_struct *tty);
322 extern speed_t tty_get_baud_rate(struct tty_struct *tty);
323 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
324 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
325 
326 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
327 extern void tty_ldisc_deref(struct tty_ldisc *);
328 extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
329 
330 extern struct tty_ldisc *tty_ldisc_get(int);
331 extern void tty_ldisc_put(int);
332 
333 extern void tty_wakeup(struct tty_struct *tty);
334 extern void tty_ldisc_flush(struct tty_struct *tty);
335 
336 extern int tty_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
337 		     unsigned long arg);
338 
339 extern dev_t tty_devnum(struct tty_struct *tty);
340 extern void proc_clear_tty(struct task_struct *p);
341 extern struct tty_struct *get_current_tty(void);
342 
343 extern struct mutex tty_mutex;
344 
345 extern void tty_write_unlock(struct tty_struct *tty);
346 extern int tty_write_lock(struct tty_struct *tty, int ndelay);
347 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
348 
349 
350 
351 /* n_tty.c */
352 extern struct tty_ldisc tty_ldisc_N_TTY;
353 
354 /* tty_audit.c */
355 #ifdef CONFIG_AUDIT
356 extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
357 			       size_t size);
358 extern void tty_audit_exit(void);
359 extern void tty_audit_fork(struct signal_struct *sig);
360 extern void tty_audit_push(struct tty_struct *tty);
361 extern void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid);
362 extern void tty_audit_opening(void);
363 #else
364 static inline void tty_audit_add_data(struct tty_struct *tty,
365 				      unsigned char *data, size_t size)
366 {
367 }
368 static inline void tty_audit_exit(void)
369 {
370 }
371 static inline void tty_audit_fork(struct signal_struct *sig)
372 {
373 }
374 static inline void tty_audit_push(struct tty_struct *tty)
375 {
376 }
377 static inline void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid)
378 {
379 }
380 static inline void tty_audit_opening(void)
381 {
382 }
383 #endif
384 
385 /* tty_ioctl.c */
386 extern int n_tty_ioctl(struct tty_struct * tty, struct file * file,
387 		       unsigned int cmd, unsigned long arg);
388 
389 /* serial.c */
390 
391 extern void serial_console_init(void);
392 
393 /* pcxx.c */
394 
395 extern int pcxe_open(struct tty_struct *tty, struct file *filp);
396 
397 /* printk.c */
398 
399 extern void console_print(const char *);
400 
401 /* vt.c */
402 
403 extern int vt_ioctl(struct tty_struct *tty, struct file * file,
404 		    unsigned int cmd, unsigned long arg);
405 
406 #endif /* __KERNEL__ */
407 #endif
408