| 1 |
199 |
simons |
/*
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| 2 |
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* n_tty.c --- implements the N_TTY line discipline.
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*
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| 4 |
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* This code used to be in tty_io.c, but things are getting hairy
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* enough that it made sense to split things off. (The N_TTY
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| 6 |
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* processing has changed so much that it's hardly recognizable,
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| 7 |
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* anyway...)
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| 8 |
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*
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| 9 |
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* Note that the open routine for N_TTY is guaranteed never to return
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* an error. This is because Linux will fall back to setting a line
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| 11 |
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* to N_TTY if it can not switch to any other line discipline.
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*
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| 13 |
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* Written by Theodore Ts'o, Copyright 1994.
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*
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* This file also contains code originally written by Linus Torvalds,
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* Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
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*
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| 18 |
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* This file may be redistributed under the terms of the GNU Public
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* License.
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*/
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#include <linux/types.h>
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| 23 |
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#include <linux/major.h>
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| 24 |
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#include <linux/errno.h>
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| 25 |
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#include <linux/signal.h>
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| 26 |
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#include <linux/fcntl.h>
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| 27 |
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#include <linux/sched.h>
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| 28 |
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#include <linux/interrupt.h>
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| 29 |
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#include <linux/tty.h>
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#include <linux/timer.h>
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| 31 |
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#include <linux/ctype.h>
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| 32 |
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#include <linux/kd.h>
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| 33 |
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#include <linux/mm.h>
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| 34 |
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#include <linux/string.h>
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#include <linux/malloc.h>
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| 37 |
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#include <asm/segment.h>
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| 38 |
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#include <asm/system.h>
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| 39 |
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#include <asm/bitops.h>
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#define CONSOLE_DEV MKDEV(TTY_MAJOR,0)
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| 43 |
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#ifndef MIN
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#define MIN(a,b) ((a) < (b) ? (a) : (b))
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#endif
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| 47 |
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/* number of characters left in xmit buffer before select has we have room */
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#define WAKEUP_CHARS 256
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| 49 |
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| 50 |
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/*
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| 51 |
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* This defines the low- and high-watermarks for throttling and
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| 52 |
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* unthrottling the TTY driver. These watermarks are used for
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| 53 |
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* controlling the space in the read buffer.
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| 54 |
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*/
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| 55 |
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#define TTY_THRESHOLD_THROTTLE (N_TTY_BUF_SIZE - 128)
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#define TTY_THRESHOLD_UNTHROTTLE 128
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| 57 |
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| 58 |
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static inline void put_tty_queue(unsigned char c, struct tty_struct *tty)
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| 59 |
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{
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| 60 |
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if (tty->read_cnt < N_TTY_BUF_SIZE) {
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| 61 |
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tty->read_buf[tty->read_head] = c;
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| 62 |
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tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
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| 63 |
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tty->read_cnt++;
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| 64 |
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}
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| 65 |
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}
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| 66 |
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| 67 |
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/*
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| 68 |
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* Flush the input buffer
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| 69 |
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*/
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| 70 |
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void n_tty_flush_buffer(struct tty_struct * tty)
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| 71 |
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{
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| 72 |
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tty->read_head = tty->read_tail = tty->read_cnt = 0;
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| 73 |
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tty->canon_head = tty->canon_data = tty->erasing = 0;
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| 74 |
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memset(&tty->read_flags, 0, sizeof tty->read_flags);
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| 75 |
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| 76 |
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if (!tty->link)
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| 77 |
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return;
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| 78 |
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| 79 |
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if (tty->driver.unthrottle)
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| 80 |
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(tty->driver.unthrottle)(tty);
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| 81 |
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if (tty->link->packet) {
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| 82 |
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tty->ctrl_status |= TIOCPKT_FLUSHREAD;
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| 83 |
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wake_up_interruptible(&tty->link->read_wait);
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| 84 |
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}
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| 85 |
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}
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| 86 |
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| 87 |
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/*
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| 88 |
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* Return number of characters buffered to be delivered to user
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| 89 |
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*/
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| 90 |
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int n_tty_chars_in_buffer(struct tty_struct *tty)
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| 91 |
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{
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| 92 |
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if (tty->icanon) {
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| 93 |
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if (!tty->canon_data) return 0;
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| 94 |
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| 95 |
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return (tty->canon_head > tty->read_tail) ?
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| 96 |
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tty->canon_head - tty->read_tail :
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| 97 |
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tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
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| 98 |
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}
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| 99 |
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return tty->read_cnt;
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| 100 |
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}
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| 101 |
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| 102 |
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/*
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| 103 |
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* Perform OPOST processing. Returns -1 when the output device is
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| 104 |
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* full and the character must be retried.
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| 105 |
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*/
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| 106 |
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static int opost(unsigned char c, struct tty_struct *tty)
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| 107 |
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{
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| 108 |
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int space, spaces;
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| 109 |
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| 110 |
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space = tty->driver.write_room(tty);
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| 111 |
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if (!space)
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| 112 |
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return -1;
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| 113 |
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| 114 |
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if (O_OPOST(tty)) {
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| 115 |
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switch (c) {
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| 116 |
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case '\n':
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| 117 |
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if (O_ONLRET(tty))
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| 118 |
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tty->column = 0;
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| 119 |
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if (O_ONLCR(tty)) {
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| 120 |
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if (space < 2)
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| 121 |
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return -1;
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| 122 |
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tty->driver.put_char(tty, '\r');
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| 123 |
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tty->column = 0;
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| 124 |
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}
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| 125 |
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tty->canon_column = tty->column;
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| 126 |
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break;
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| 127 |
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case '\r':
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| 128 |
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if (O_ONOCR(tty) && tty->column == 0)
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| 129 |
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return 0;
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| 130 |
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if (O_OCRNL(tty)) {
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| 131 |
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c = '\n';
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| 132 |
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if (O_ONLRET(tty))
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| 133 |
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tty->canon_column = tty->column = 0;
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| 134 |
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break;
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| 135 |
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}
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| 136 |
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tty->canon_column = tty->column = 0;
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| 137 |
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break;
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| 138 |
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case '\t':
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| 139 |
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spaces = 8 - (tty->column & 7);
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| 140 |
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if (O_TABDLY(tty) == XTABS) {
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| 141 |
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if (space < spaces)
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| 142 |
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return -1;
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| 143 |
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tty->column += spaces;
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| 144 |
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tty->driver.write(tty, 0, " ", spaces);
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| 145 |
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return 0;
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| 146 |
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}
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| 147 |
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tty->column += spaces;
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| 148 |
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break;
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| 149 |
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case '\b':
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| 150 |
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if (tty->column > 0)
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| 151 |
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tty->column--;
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| 152 |
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break;
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| 153 |
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default:
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| 154 |
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if (O_OLCUC(tty))
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| 155 |
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c = toupper(c);
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| 156 |
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if (!iscntrl(c))
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| 157 |
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tty->column++;
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| 158 |
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break;
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| 159 |
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}
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| 160 |
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}
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| 161 |
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tty->driver.put_char(tty, c);
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| 162 |
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return 0;
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| 163 |
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}
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| 164 |
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| 165 |
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static inline void put_char(unsigned char c, struct tty_struct *tty)
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| 166 |
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{
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| 167 |
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tty->driver.put_char(tty, c);
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| 168 |
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}
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| 169 |
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| 170 |
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/* Must be called only when L_ECHO(tty) is true. */
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| 171 |
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| 172 |
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static void echo_char(unsigned char c, struct tty_struct *tty)
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| 173 |
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{
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| 174 |
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if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') {
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| 175 |
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put_char('^', tty);
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| 176 |
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put_char(c ^ 0100, tty);
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| 177 |
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tty->column += 2;
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| 178 |
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} else
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| 179 |
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opost(c, tty);
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| 180 |
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}
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| 181 |
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| 182 |
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static inline void finish_erasing(struct tty_struct *tty)
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| 183 |
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{
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| 184 |
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if (tty->erasing) {
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| 185 |
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put_char('/', tty);
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| 186 |
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tty->column += 2;
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| 187 |
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tty->erasing = 0;
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| 188 |
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}
|
| 189 |
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}
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| 190 |
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| 191 |
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static void eraser(unsigned char c, struct tty_struct *tty)
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| 192 |
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{
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| 193 |
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enum { ERASE, WERASE, KILL } kill_type;
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| 194 |
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int head, seen_alnums;
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| 195 |
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| 196 |
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if (tty->read_head == tty->canon_head) {
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| 197 |
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/* opost('\a', tty); */ /* what do you think? */
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| 198 |
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return;
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| 199 |
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}
|
| 200 |
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if (c == ERASE_CHAR(tty))
|
| 201 |
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kill_type = ERASE;
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| 202 |
|
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else if (c == WERASE_CHAR(tty))
|
| 203 |
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kill_type = WERASE;
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| 204 |
|
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else {
|
| 205 |
|
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if (!L_ECHO(tty)) {
|
| 206 |
|
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tty->read_cnt -= ((tty->read_head - tty->canon_head) &
|
| 207 |
|
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(N_TTY_BUF_SIZE - 1));
|
| 208 |
|
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tty->read_head = tty->canon_head;
|
| 209 |
|
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return;
|
| 210 |
|
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}
|
| 211 |
|
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if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
|
| 212 |
|
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tty->read_cnt -= ((tty->read_head - tty->canon_head) &
|
| 213 |
|
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(N_TTY_BUF_SIZE - 1));
|
| 214 |
|
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tty->read_head = tty->canon_head;
|
| 215 |
|
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finish_erasing(tty);
|
| 216 |
|
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echo_char(KILL_CHAR(tty), tty);
|
| 217 |
|
|
/* Add a newline if ECHOK is on and ECHOKE is off. */
|
| 218 |
|
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if (L_ECHOK(tty))
|
| 219 |
|
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opost('\n', tty);
|
| 220 |
|
|
return;
|
| 221 |
|
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}
|
| 222 |
|
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kill_type = KILL;
|
| 223 |
|
|
}
|
| 224 |
|
|
|
| 225 |
|
|
seen_alnums = 0;
|
| 226 |
|
|
while (tty->read_head != tty->canon_head) {
|
| 227 |
|
|
head = (tty->read_head - 1) & (N_TTY_BUF_SIZE-1);
|
| 228 |
|
|
c = tty->read_buf[head];
|
| 229 |
|
|
if (kill_type == WERASE) {
|
| 230 |
|
|
/* Equivalent to BSD's ALTWERASE. */
|
| 231 |
|
|
if (isalnum(c) || c == '_')
|
| 232 |
|
|
seen_alnums++;
|
| 233 |
|
|
else if (seen_alnums)
|
| 234 |
|
|
break;
|
| 235 |
|
|
}
|
| 236 |
|
|
tty->read_head = head;
|
| 237 |
|
|
tty->read_cnt--;
|
| 238 |
|
|
if (L_ECHO(tty)) {
|
| 239 |
|
|
if (L_ECHOPRT(tty)) {
|
| 240 |
|
|
if (!tty->erasing) {
|
| 241 |
|
|
put_char('\\', tty);
|
| 242 |
|
|
tty->column++;
|
| 243 |
|
|
tty->erasing = 1;
|
| 244 |
|
|
}
|
| 245 |
|
|
echo_char(c, tty);
|
| 246 |
|
|
} else if (kill_type == ERASE && !L_ECHOE(tty)) {
|
| 247 |
|
|
echo_char(ERASE_CHAR(tty), tty);
|
| 248 |
|
|
} else if (c == '\t') {
|
| 249 |
|
|
unsigned int col = tty->canon_column;
|
| 250 |
|
|
unsigned long tail = tty->canon_head;
|
| 251 |
|
|
|
| 252 |
|
|
/* Find the column of the last char. */
|
| 253 |
|
|
while (tail != tty->read_head) {
|
| 254 |
|
|
c = tty->read_buf[tail];
|
| 255 |
|
|
if (c == '\t')
|
| 256 |
|
|
col = (col | 7) + 1;
|
| 257 |
|
|
else if (iscntrl(c)) {
|
| 258 |
|
|
if (L_ECHOCTL(tty))
|
| 259 |
|
|
col += 2;
|
| 260 |
|
|
} else
|
| 261 |
|
|
col++;
|
| 262 |
|
|
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
|
| 263 |
|
|
}
|
| 264 |
|
|
|
| 265 |
|
|
/* should never happen */
|
| 266 |
|
|
if (tty->column > 0x80000000)
|
| 267 |
|
|
tty->column = 0;
|
| 268 |
|
|
|
| 269 |
|
|
/* Now backup to that column. */
|
| 270 |
|
|
while (tty->column > col) {
|
| 271 |
|
|
/* Can't use opost here. */
|
| 272 |
|
|
put_char('\b', tty);
|
| 273 |
|
|
if (tty->column > 0)
|
| 274 |
|
|
tty->column--;
|
| 275 |
|
|
}
|
| 276 |
|
|
} else {
|
| 277 |
|
|
if (iscntrl(c) && L_ECHOCTL(tty)) {
|
| 278 |
|
|
put_char('\b', tty);
|
| 279 |
|
|
put_char(' ', tty);
|
| 280 |
|
|
put_char('\b', tty);
|
| 281 |
|
|
if (tty->column > 0)
|
| 282 |
|
|
tty->column--;
|
| 283 |
|
|
}
|
| 284 |
|
|
if (!iscntrl(c) || L_ECHOCTL(tty)) {
|
| 285 |
|
|
put_char('\b', tty);
|
| 286 |
|
|
put_char(' ', tty);
|
| 287 |
|
|
put_char('\b', tty);
|
| 288 |
|
|
if (tty->column > 0)
|
| 289 |
|
|
tty->column--;
|
| 290 |
|
|
}
|
| 291 |
|
|
}
|
| 292 |
|
|
}
|
| 293 |
|
|
if (kill_type == ERASE)
|
| 294 |
|
|
break;
|
| 295 |
|
|
}
|
| 296 |
|
|
if (tty->read_head == tty->canon_head)
|
| 297 |
|
|
finish_erasing(tty);
|
| 298 |
|
|
}
|
| 299 |
|
|
|
| 300 |
|
|
static inline void isig(int sig, struct tty_struct *tty, int flush)
|
| 301 |
|
|
{
|
| 302 |
|
|
if (tty->pgrp > 0)
|
| 303 |
|
|
kill_pg(tty->pgrp, sig, 1);
|
| 304 |
|
|
if (flush || !L_NOFLSH(tty)) {
|
| 305 |
|
|
n_tty_flush_buffer(tty);
|
| 306 |
|
|
if (tty->driver.flush_buffer)
|
| 307 |
|
|
tty->driver.flush_buffer(tty);
|
| 308 |
|
|
}
|
| 309 |
|
|
}
|
| 310 |
|
|
|
| 311 |
|
|
static inline void n_tty_receive_break(struct tty_struct *tty)
|
| 312 |
|
|
{
|
| 313 |
|
|
if (I_IGNBRK(tty))
|
| 314 |
|
|
return;
|
| 315 |
|
|
if (I_BRKINT(tty)) {
|
| 316 |
|
|
isig(SIGINT, tty, 1);
|
| 317 |
|
|
return;
|
| 318 |
|
|
}
|
| 319 |
|
|
if (I_PARMRK(tty)) {
|
| 320 |
|
|
put_tty_queue('\377', tty);
|
| 321 |
|
|
put_tty_queue('\0', tty);
|
| 322 |
|
|
}
|
| 323 |
|
|
put_tty_queue('\0', tty);
|
| 324 |
|
|
wake_up_interruptible(&tty->read_wait);
|
| 325 |
|
|
}
|
| 326 |
|
|
|
| 327 |
|
|
static inline void n_tty_receive_overrun(struct tty_struct *tty)
|
| 328 |
|
|
{
|
| 329 |
|
|
char buf[64];
|
| 330 |
|
|
|
| 331 |
|
|
tty->num_overrun++;
|
| 332 |
|
|
if (tty->overrun_time < (jiffies - HZ)) {
|
| 333 |
|
|
printk("%s: %d input overrun(s)\n", _tty_name(tty, buf),
|
| 334 |
|
|
tty->num_overrun);
|
| 335 |
|
|
tty->overrun_time = jiffies;
|
| 336 |
|
|
tty->num_overrun = 0;
|
| 337 |
|
|
}
|
| 338 |
|
|
}
|
| 339 |
|
|
|
| 340 |
|
|
static inline void n_tty_receive_parity_error(struct tty_struct *tty,
|
| 341 |
|
|
unsigned char c)
|
| 342 |
|
|
{
|
| 343 |
|
|
if (I_IGNPAR(tty)) {
|
| 344 |
|
|
return;
|
| 345 |
|
|
}
|
| 346 |
|
|
if (I_PARMRK(tty)) {
|
| 347 |
|
|
put_tty_queue('\377', tty);
|
| 348 |
|
|
put_tty_queue('\0', tty);
|
| 349 |
|
|
put_tty_queue(c, tty);
|
| 350 |
|
|
} else if (I_INPCK(tty))
|
| 351 |
|
|
put_tty_queue('\0', tty);
|
| 352 |
|
|
else
|
| 353 |
|
|
put_tty_queue(c, tty);
|
| 354 |
|
|
wake_up_interruptible(&tty->read_wait);
|
| 355 |
|
|
}
|
| 356 |
|
|
|
| 357 |
|
|
static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
|
| 358 |
|
|
{
|
| 359 |
|
|
if (tty->raw) {
|
| 360 |
|
|
put_tty_queue(c, tty);
|
| 361 |
|
|
return;
|
| 362 |
|
|
}
|
| 363 |
|
|
|
| 364 |
|
|
if (tty->stopped && I_IXON(tty) && I_IXANY(tty)) {
|
| 365 |
|
|
start_tty(tty);
|
| 366 |
|
|
return;
|
| 367 |
|
|
}
|
| 368 |
|
|
|
| 369 |
|
|
if (I_ISTRIP(tty))
|
| 370 |
|
|
c &= 0x7f;
|
| 371 |
|
|
if (I_IUCLC(tty) && L_IEXTEN(tty))
|
| 372 |
|
|
c=tolower(c);
|
| 373 |
|
|
|
| 374 |
|
|
if (tty->closing) {
|
| 375 |
|
|
if (I_IXON(tty)) {
|
| 376 |
|
|
if (c == START_CHAR(tty))
|
| 377 |
|
|
start_tty(tty);
|
| 378 |
|
|
else if (c == STOP_CHAR(tty))
|
| 379 |
|
|
stop_tty(tty);
|
| 380 |
|
|
}
|
| 381 |
|
|
return;
|
| 382 |
|
|
}
|
| 383 |
|
|
|
| 384 |
|
|
/*
|
| 385 |
|
|
* If the previous character was LNEXT, or we know that this
|
| 386 |
|
|
* character is not one of the characters that we'll have to
|
| 387 |
|
|
* handle specially, do shortcut processing to speed things
|
| 388 |
|
|
* up.
|
| 389 |
|
|
*/
|
| 390 |
|
|
if (!test_bit(c, &tty->process_char_map) || tty->lnext) {
|
| 391 |
|
|
finish_erasing(tty);
|
| 392 |
|
|
tty->lnext = 0;
|
| 393 |
|
|
if (L_ECHO(tty)) {
|
| 394 |
|
|
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
|
| 395 |
|
|
put_char('\a', tty); /* beep if no space */
|
| 396 |
|
|
return;
|
| 397 |
|
|
}
|
| 398 |
|
|
/* Record the column of first canon char. */
|
| 399 |
|
|
if (tty->canon_head == tty->read_head)
|
| 400 |
|
|
tty->canon_column = tty->column;
|
| 401 |
|
|
echo_char(c, tty);
|
| 402 |
|
|
}
|
| 403 |
|
|
if (I_PARMRK(tty) && c == (unsigned char) '\377')
|
| 404 |
|
|
put_tty_queue(c, tty);
|
| 405 |
|
|
put_tty_queue(c, tty);
|
| 406 |
|
|
return;
|
| 407 |
|
|
}
|
| 408 |
|
|
|
| 409 |
|
|
if (c == '\r') {
|
| 410 |
|
|
if (I_IGNCR(tty))
|
| 411 |
|
|
return;
|
| 412 |
|
|
if (I_ICRNL(tty))
|
| 413 |
|
|
c = '\n';
|
| 414 |
|
|
} else if (c == '\n' && I_INLCR(tty))
|
| 415 |
|
|
c = '\r';
|
| 416 |
|
|
if (I_IXON(tty)) {
|
| 417 |
|
|
if (c == START_CHAR(tty)) {
|
| 418 |
|
|
start_tty(tty);
|
| 419 |
|
|
return;
|
| 420 |
|
|
}
|
| 421 |
|
|
if (c == STOP_CHAR(tty)) {
|
| 422 |
|
|
stop_tty(tty);
|
| 423 |
|
|
return;
|
| 424 |
|
|
}
|
| 425 |
|
|
}
|
| 426 |
|
|
if (L_ISIG(tty)) {
|
| 427 |
|
|
int signal;
|
| 428 |
|
|
signal = SIGINT;
|
| 429 |
|
|
if (c == INTR_CHAR(tty))
|
| 430 |
|
|
goto send_signal;
|
| 431 |
|
|
signal = SIGQUIT;
|
| 432 |
|
|
if (c == QUIT_CHAR(tty))
|
| 433 |
|
|
goto send_signal;
|
| 434 |
|
|
signal = SIGTSTP;
|
| 435 |
|
|
if (c == SUSP_CHAR(tty)) {
|
| 436 |
|
|
send_signal:
|
| 437 |
|
|
isig(signal, tty, 0);
|
| 438 |
|
|
return;
|
| 439 |
|
|
}
|
| 440 |
|
|
}
|
| 441 |
|
|
if (L_ICANON(tty)) {
|
| 442 |
|
|
if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
|
| 443 |
|
|
(c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
|
| 444 |
|
|
eraser(c, tty);
|
| 445 |
|
|
return;
|
| 446 |
|
|
}
|
| 447 |
|
|
if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
|
| 448 |
|
|
tty->lnext = 1;
|
| 449 |
|
|
if (L_ECHO(tty)) {
|
| 450 |
|
|
finish_erasing(tty);
|
| 451 |
|
|
if (L_ECHOCTL(tty)) {
|
| 452 |
|
|
put_char('^', tty);
|
| 453 |
|
|
put_char('\b', tty);
|
| 454 |
|
|
}
|
| 455 |
|
|
}
|
| 456 |
|
|
return;
|
| 457 |
|
|
}
|
| 458 |
|
|
if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
|
| 459 |
|
|
L_IEXTEN(tty)) {
|
| 460 |
|
|
unsigned long tail = tty->canon_head;
|
| 461 |
|
|
|
| 462 |
|
|
finish_erasing(tty);
|
| 463 |
|
|
echo_char(c, tty);
|
| 464 |
|
|
opost('\n', tty);
|
| 465 |
|
|
while (tail != tty->read_head) {
|
| 466 |
|
|
echo_char(tty->read_buf[tail], tty);
|
| 467 |
|
|
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
|
| 468 |
|
|
}
|
| 469 |
|
|
return;
|
| 470 |
|
|
}
|
| 471 |
|
|
if (c == '\n') {
|
| 472 |
|
|
if (L_ECHO(tty) || L_ECHONL(tty)) {
|
| 473 |
|
|
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
|
| 474 |
|
|
put_char('\a', tty);
|
| 475 |
|
|
return;
|
| 476 |
|
|
}
|
| 477 |
|
|
opost('\n', tty);
|
| 478 |
|
|
}
|
| 479 |
|
|
goto handle_newline;
|
| 480 |
|
|
}
|
| 481 |
|
|
if (c == EOF_CHAR(tty)) {
|
| 482 |
|
|
if (tty->canon_head != tty->read_head)
|
| 483 |
|
|
set_bit(TTY_PUSH, &tty->flags);
|
| 484 |
|
|
c = __DISABLED_CHAR;
|
| 485 |
|
|
goto handle_newline;
|
| 486 |
|
|
}
|
| 487 |
|
|
if ((c == EOL_CHAR(tty)) ||
|
| 488 |
|
|
(c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
|
| 489 |
|
|
/*
|
| 490 |
|
|
* XXX are EOL_CHAR and EOL2_CHAR echoed?!?
|
| 491 |
|
|
*/
|
| 492 |
|
|
if (L_ECHO(tty)) {
|
| 493 |
|
|
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
|
| 494 |
|
|
put_char('\a', tty);
|
| 495 |
|
|
return;
|
| 496 |
|
|
}
|
| 497 |
|
|
/* Record the column of first canon char. */
|
| 498 |
|
|
if (tty->canon_head == tty->read_head)
|
| 499 |
|
|
tty->canon_column = tty->column;
|
| 500 |
|
|
echo_char(c, tty);
|
| 501 |
|
|
}
|
| 502 |
|
|
/*
|
| 503 |
|
|
* XXX does PARMRK doubling happen for
|
| 504 |
|
|
* EOL_CHAR and EOL2_CHAR?
|
| 505 |
|
|
*/
|
| 506 |
|
|
if (I_PARMRK(tty) && c == (unsigned char) '\377')
|
| 507 |
|
|
put_tty_queue(c, tty);
|
| 508 |
|
|
|
| 509 |
|
|
handle_newline:
|
| 510 |
|
|
set_bit(tty->read_head, &tty->read_flags);
|
| 511 |
|
|
put_tty_queue(c, tty);
|
| 512 |
|
|
tty->canon_head = tty->read_head;
|
| 513 |
|
|
tty->canon_data++;
|
| 514 |
|
|
if (tty->fasync)
|
| 515 |
|
|
kill_fasync(tty->fasync, SIGIO);
|
| 516 |
|
|
if (tty->read_wait)
|
| 517 |
|
|
wake_up_interruptible(&tty->read_wait);
|
| 518 |
|
|
return;
|
| 519 |
|
|
}
|
| 520 |
|
|
}
|
| 521 |
|
|
|
| 522 |
|
|
finish_erasing(tty);
|
| 523 |
|
|
if (L_ECHO(tty)) {
|
| 524 |
|
|
if (tty->read_cnt >= N_TTY_BUF_SIZE-1) {
|
| 525 |
|
|
put_char('\a', tty); /* beep if no space */
|
| 526 |
|
|
return;
|
| 527 |
|
|
}
|
| 528 |
|
|
if (c == '\n')
|
| 529 |
|
|
opost('\n', tty);
|
| 530 |
|
|
else {
|
| 531 |
|
|
/* Record the column of first canon char. */
|
| 532 |
|
|
if (tty->canon_head == tty->read_head)
|
| 533 |
|
|
tty->canon_column = tty->column;
|
| 534 |
|
|
echo_char(c, tty);
|
| 535 |
|
|
}
|
| 536 |
|
|
}
|
| 537 |
|
|
|
| 538 |
|
|
if (I_PARMRK(tty) && c == (unsigned char) '\377')
|
| 539 |
|
|
put_tty_queue(c, tty);
|
| 540 |
|
|
|
| 541 |
|
|
put_tty_queue(c, tty);
|
| 542 |
|
|
}
|
| 543 |
|
|
|
| 544 |
|
|
static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
|
| 545 |
|
|
char *fp, int count)
|
| 546 |
|
|
{
|
| 547 |
|
|
const unsigned char *p;
|
| 548 |
|
|
char *f, flags = 0;
|
| 549 |
|
|
int i;
|
| 550 |
|
|
|
| 551 |
|
|
if (!tty->read_buf)
|
| 552 |
|
|
return;
|
| 553 |
|
|
|
| 554 |
|
|
if (tty->real_raw) {
|
| 555 |
|
|
i = MIN(count, MIN(N_TTY_BUF_SIZE - tty->read_cnt,
|
| 556 |
|
|
N_TTY_BUF_SIZE - tty->read_head));
|
| 557 |
|
|
memcpy(tty->read_buf + tty->read_head, cp, i);
|
| 558 |
|
|
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
|
| 559 |
|
|
tty->read_cnt += i;
|
| 560 |
|
|
cp += i;
|
| 561 |
|
|
count -= i;
|
| 562 |
|
|
|
| 563 |
|
|
i = MIN(count, MIN(N_TTY_BUF_SIZE - tty->read_cnt,
|
| 564 |
|
|
N_TTY_BUF_SIZE - tty->read_head));
|
| 565 |
|
|
memcpy(tty->read_buf + tty->read_head, cp, i);
|
| 566 |
|
|
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
|
| 567 |
|
|
tty->read_cnt += i;
|
| 568 |
|
|
} else {
|
| 569 |
|
|
for (i=count, p = cp, f = fp; i; i--, p++) {
|
| 570 |
|
|
if (f)
|
| 571 |
|
|
flags = *f++;
|
| 572 |
|
|
switch (flags) {
|
| 573 |
|
|
case TTY_NORMAL:
|
| 574 |
|
|
n_tty_receive_char(tty, *p);
|
| 575 |
|
|
break;
|
| 576 |
|
|
case TTY_BREAK:
|
| 577 |
|
|
n_tty_receive_break(tty);
|
| 578 |
|
|
break;
|
| 579 |
|
|
case TTY_PARITY:
|
| 580 |
|
|
case TTY_FRAME:
|
| 581 |
|
|
n_tty_receive_parity_error(tty, *p);
|
| 582 |
|
|
break;
|
| 583 |
|
|
case TTY_OVERRUN:
|
| 584 |
|
|
n_tty_receive_overrun(tty);
|
| 585 |
|
|
break;
|
| 586 |
|
|
default:
|
| 587 |
|
|
printk("%s: unknown flag %d\n", tty_name(tty),
|
| 588 |
|
|
flags);
|
| 589 |
|
|
break;
|
| 590 |
|
|
}
|
| 591 |
|
|
}
|
| 592 |
|
|
if (tty->driver.flush_chars)
|
| 593 |
|
|
tty->driver.flush_chars(tty);
|
| 594 |
|
|
}
|
| 595 |
|
|
|
| 596 |
|
|
if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) {
|
| 597 |
|
|
if (tty->fasync)
|
| 598 |
|
|
kill_fasync(tty->fasync, SIGIO);
|
| 599 |
|
|
if (tty->read_wait)
|
| 600 |
|
|
wake_up_interruptible(&tty->read_wait);
|
| 601 |
|
|
}
|
| 602 |
|
|
|
| 603 |
|
|
if ((tty->read_cnt >= TTY_THRESHOLD_THROTTLE) &&
|
| 604 |
|
|
tty->driver.throttle &&
|
| 605 |
|
|
!set_bit(TTY_THROTTLED, &tty->flags))
|
| 606 |
|
|
tty->driver.throttle(tty);
|
| 607 |
|
|
}
|
| 608 |
|
|
|
| 609 |
|
|
static int n_tty_receive_room(struct tty_struct *tty)
|
| 610 |
|
|
{
|
| 611 |
|
|
int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
|
| 612 |
|
|
|
| 613 |
|
|
/*
|
| 614 |
|
|
* If we are doing input canonicalization, and there are no
|
| 615 |
|
|
* pending newlines, let characters through without limit, so
|
| 616 |
|
|
* that erase characters will be handled. Other excess
|
| 617 |
|
|
* characters will be beeped.
|
| 618 |
|
|
*/
|
| 619 |
|
|
if (tty->icanon && !tty->canon_data)
|
| 620 |
|
|
return N_TTY_BUF_SIZE;
|
| 621 |
|
|
|
| 622 |
|
|
if (left > 0)
|
| 623 |
|
|
return left;
|
| 624 |
|
|
return 0;
|
| 625 |
|
|
}
|
| 626 |
|
|
|
| 627 |
|
|
int is_ignored(int sig)
|
| 628 |
|
|
{
|
| 629 |
|
|
return ((current->blocked & (1<<(sig-1))) ||
|
| 630 |
|
|
(current->sig->action[sig-1].sa_handler == SIG_IGN));
|
| 631 |
|
|
}
|
| 632 |
|
|
|
| 633 |
|
|
static void n_tty_set_termios(struct tty_struct *tty, struct termios * old)
|
| 634 |
|
|
{
|
| 635 |
|
|
if (!tty)
|
| 636 |
|
|
return;
|
| 637 |
|
|
|
| 638 |
|
|
tty->icanon = (L_ICANON(tty) != 0);
|
| 639 |
|
|
if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
|
| 640 |
|
|
I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
|
| 641 |
|
|
I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
|
| 642 |
|
|
I_PARMRK(tty)) {
|
| 643 |
|
|
cli();
|
| 644 |
|
|
memset(tty->process_char_map, 0, 256/8);
|
| 645 |
|
|
|
| 646 |
|
|
if (I_IGNCR(tty) || I_ICRNL(tty))
|
| 647 |
|
|
set_bit('\r', &tty->process_char_map);
|
| 648 |
|
|
if (I_INLCR(tty))
|
| 649 |
|
|
set_bit('\n', &tty->process_char_map);
|
| 650 |
|
|
|
| 651 |
|
|
if (L_ICANON(tty)) {
|
| 652 |
|
|
set_bit(ERASE_CHAR(tty), &tty->process_char_map);
|
| 653 |
|
|
set_bit(KILL_CHAR(tty), &tty->process_char_map);
|
| 654 |
|
|
set_bit(EOF_CHAR(tty), &tty->process_char_map);
|
| 655 |
|
|
set_bit('\n', &tty->process_char_map);
|
| 656 |
|
|
set_bit(EOL_CHAR(tty), &tty->process_char_map);
|
| 657 |
|
|
if (L_IEXTEN(tty)) {
|
| 658 |
|
|
set_bit(WERASE_CHAR(tty),
|
| 659 |
|
|
&tty->process_char_map);
|
| 660 |
|
|
set_bit(LNEXT_CHAR(tty),
|
| 661 |
|
|
&tty->process_char_map);
|
| 662 |
|
|
set_bit(EOL2_CHAR(tty),
|
| 663 |
|
|
&tty->process_char_map);
|
| 664 |
|
|
if (L_ECHO(tty))
|
| 665 |
|
|
set_bit(REPRINT_CHAR(tty),
|
| 666 |
|
|
&tty->process_char_map);
|
| 667 |
|
|
}
|
| 668 |
|
|
}
|
| 669 |
|
|
if (I_IXON(tty)) {
|
| 670 |
|
|
set_bit(START_CHAR(tty), &tty->process_char_map);
|
| 671 |
|
|
set_bit(STOP_CHAR(tty), &tty->process_char_map);
|
| 672 |
|
|
}
|
| 673 |
|
|
if (L_ISIG(tty)) {
|
| 674 |
|
|
set_bit(INTR_CHAR(tty), &tty->process_char_map);
|
| 675 |
|
|
set_bit(QUIT_CHAR(tty), &tty->process_char_map);
|
| 676 |
|
|
set_bit(SUSP_CHAR(tty), &tty->process_char_map);
|
| 677 |
|
|
}
|
| 678 |
|
|
clear_bit(__DISABLED_CHAR, &tty->process_char_map);
|
| 679 |
|
|
sti();
|
| 680 |
|
|
tty->raw = 0;
|
| 681 |
|
|
tty->real_raw = 0;
|
| 682 |
|
|
} else {
|
| 683 |
|
|
tty->raw = 1;
|
| 684 |
|
|
if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
|
| 685 |
|
|
(I_IGNPAR(tty) || !I_INPCK(tty)) &&
|
| 686 |
|
|
(tty->driver.flags & TTY_DRIVER_REAL_RAW))
|
| 687 |
|
|
tty->real_raw = 1;
|
| 688 |
|
|
else
|
| 689 |
|
|
tty->real_raw = 0;
|
| 690 |
|
|
}
|
| 691 |
|
|
}
|
| 692 |
|
|
|
| 693 |
|
|
static void n_tty_close(struct tty_struct *tty)
|
| 694 |
|
|
{
|
| 695 |
|
|
n_tty_flush_buffer(tty);
|
| 696 |
|
|
if (tty->read_buf) {
|
| 697 |
|
|
free_page((unsigned long) tty->read_buf);
|
| 698 |
|
|
tty->read_buf = 0;
|
| 699 |
|
|
}
|
| 700 |
|
|
}
|
| 701 |
|
|
|
| 702 |
|
|
static int n_tty_open(struct tty_struct *tty)
|
| 703 |
|
|
{
|
| 704 |
|
|
if (!tty)
|
| 705 |
|
|
return -EINVAL;
|
| 706 |
|
|
|
| 707 |
|
|
if (!tty->read_buf) {
|
| 708 |
|
|
tty->read_buf = (unsigned char *)
|
| 709 |
|
|
get_free_page(intr_count ? GFP_ATOMIC : GFP_KERNEL);
|
| 710 |
|
|
if (!tty->read_buf)
|
| 711 |
|
|
return -ENOMEM;
|
| 712 |
|
|
}
|
| 713 |
|
|
memset(tty->read_buf, 0, N_TTY_BUF_SIZE);
|
| 714 |
|
|
tty->read_head = tty->read_tail = tty->read_cnt = 0;
|
| 715 |
|
|
tty->canon_head = tty->canon_data = tty->erasing = 0;
|
| 716 |
|
|
tty->column = 0;
|
| 717 |
|
|
memset(tty->read_flags, 0, sizeof(tty->read_flags));
|
| 718 |
|
|
n_tty_set_termios(tty, 0);
|
| 719 |
|
|
tty->minimum_to_wake = 1;
|
| 720 |
|
|
tty->closing = 0;
|
| 721 |
|
|
return 0;
|
| 722 |
|
|
}
|
| 723 |
|
|
|
| 724 |
|
|
static inline int input_available_p(struct tty_struct *tty, int amt)
|
| 725 |
|
|
{
|
| 726 |
|
|
if (L_ICANON(tty)) {
|
| 727 |
|
|
if (tty->canon_data)
|
| 728 |
|
|
return 1;
|
| 729 |
|
|
} else if (tty->read_cnt >= (amt ? amt : 1))
|
| 730 |
|
|
return 1;
|
| 731 |
|
|
|
| 732 |
|
|
return 0;
|
| 733 |
|
|
}
|
| 734 |
|
|
|
| 735 |
|
|
/*
|
| 736 |
|
|
* Helper function to speed up read_chan. It is only called when
|
| 737 |
|
|
* ICANON is off; it copies characters straight from the tty queue to
|
| 738 |
|
|
* user space directly. It can be profitably called twice; once to
|
| 739 |
|
|
* drain the space from the tail pointer to the (physical) end of the
|
| 740 |
|
|
* buffer, and once to drain the space from the (physical) beginning of
|
| 741 |
|
|
* the buffer to head pointer.
|
| 742 |
|
|
*/
|
| 743 |
|
|
static inline void copy_from_read_buf(struct tty_struct *tty,
|
| 744 |
|
|
unsigned char **b,
|
| 745 |
|
|
unsigned int *nr)
|
| 746 |
|
|
|
| 747 |
|
|
{
|
| 748 |
|
|
int n;
|
| 749 |
|
|
|
| 750 |
|
|
n = MIN(*nr, MIN(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail));
|
| 751 |
|
|
if (!n)
|
| 752 |
|
|
return;
|
| 753 |
|
|
memcpy_tofs(*b, &tty->read_buf[tty->read_tail], n);
|
| 754 |
|
|
tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
|
| 755 |
|
|
tty->read_cnt -= n;
|
| 756 |
|
|
*b += n;
|
| 757 |
|
|
*nr -= n;
|
| 758 |
|
|
}
|
| 759 |
|
|
|
| 760 |
|
|
static int read_chan(struct tty_struct *tty, struct file *file,
|
| 761 |
|
|
unsigned char *buf, unsigned int nr)
|
| 762 |
|
|
{
|
| 763 |
|
|
struct wait_queue wait = { current, NULL };
|
| 764 |
|
|
int c;
|
| 765 |
|
|
unsigned char *b = buf;
|
| 766 |
|
|
int minimum, time;
|
| 767 |
|
|
int retval = 0;
|
| 768 |
|
|
int size;
|
| 769 |
|
|
|
| 770 |
|
|
do_it_again:
|
| 771 |
|
|
|
| 772 |
|
|
if (!tty->read_buf) {
|
| 773 |
|
|
printk("n_tty_read_chan: called with read_buf == NULL?!?\n");
|
| 774 |
|
|
return -EIO;
|
| 775 |
|
|
}
|
| 776 |
|
|
|
| 777 |
|
|
/* Job control check -- must be done at start and after
|
| 778 |
|
|
every sleep (POSIX.1 7.1.1.4). */
|
| 779 |
|
|
/* NOTE: not yet done after every sleep pending a thorough
|
| 780 |
|
|
check of the logic of this change. -- jlc */
|
| 781 |
|
|
/* don't stop on /dev/console */
|
| 782 |
|
|
if (file->f_inode->i_rdev != CONSOLE_DEV &&
|
| 783 |
|
|
current->tty == tty) {
|
| 784 |
|
|
if (tty->pgrp <= 0)
|
| 785 |
|
|
printk("read_chan: tty->pgrp <= 0!\n");
|
| 786 |
|
|
else if (current->pgrp != tty->pgrp) {
|
| 787 |
|
|
if (is_ignored(SIGTTIN) ||
|
| 788 |
|
|
is_orphaned_pgrp(current->pgrp))
|
| 789 |
|
|
return -EIO;
|
| 790 |
|
|
kill_pg(current->pgrp, SIGTTIN, 1);
|
| 791 |
|
|
return -ERESTARTSYS;
|
| 792 |
|
|
}
|
| 793 |
|
|
}
|
| 794 |
|
|
|
| 795 |
|
|
if (L_ICANON(tty)) {
|
| 796 |
|
|
minimum = time = 0;
|
| 797 |
|
|
current->timeout = (unsigned long) -1;
|
| 798 |
|
|
} else {
|
| 799 |
|
|
time = (HZ / 10) * TIME_CHAR(tty);
|
| 800 |
|
|
minimum = MIN_CHAR(tty);
|
| 801 |
|
|
if (minimum) {
|
| 802 |
|
|
current->timeout = (unsigned long) -1;
|
| 803 |
|
|
if (time)
|
| 804 |
|
|
tty->minimum_to_wake = 1;
|
| 805 |
|
|
else if (!waitqueue_active(&tty->read_wait) ||
|
| 806 |
|
|
(tty->minimum_to_wake > minimum))
|
| 807 |
|
|
tty->minimum_to_wake = minimum;
|
| 808 |
|
|
} else {
|
| 809 |
|
|
if (time) {
|
| 810 |
|
|
current->timeout = time + jiffies;
|
| 811 |
|
|
time = 0;
|
| 812 |
|
|
} else
|
| 813 |
|
|
current->timeout = 0;
|
| 814 |
|
|
tty->minimum_to_wake = minimum = 1;
|
| 815 |
|
|
}
|
| 816 |
|
|
}
|
| 817 |
|
|
|
| 818 |
|
|
add_wait_queue(&tty->read_wait, &wait);
|
| 819 |
|
|
while (1) {
|
| 820 |
|
|
/* First test for status change. */
|
| 821 |
|
|
if (tty->packet && tty->link->ctrl_status) {
|
| 822 |
|
|
if (b != buf)
|
| 823 |
|
|
break;
|
| 824 |
|
|
put_user(tty->link->ctrl_status, b++);
|
| 825 |
|
|
tty->link->ctrl_status = 0;
|
| 826 |
|
|
break;
|
| 827 |
|
|
}
|
| 828 |
|
|
/* This statement must be first before checking for input
|
| 829 |
|
|
so that any interrupt will set the state back to
|
| 830 |
|
|
TASK_RUNNING. */
|
| 831 |
|
|
current->state = TASK_INTERRUPTIBLE;
|
| 832 |
|
|
|
| 833 |
|
|
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
|
| 834 |
|
|
((minimum - (b - buf)) >= 1))
|
| 835 |
|
|
tty->minimum_to_wake = (minimum - (b - buf));
|
| 836 |
|
|
|
| 837 |
|
|
if (!input_available_p(tty, 0)) {
|
| 838 |
|
|
if (tty->flags & (1 << TTY_OTHER_CLOSED)) {
|
| 839 |
|
|
retval = -EIO;
|
| 840 |
|
|
break;
|
| 841 |
|
|
}
|
| 842 |
|
|
if (tty_hung_up_p(file))
|
| 843 |
|
|
break;
|
| 844 |
|
|
if (!current->timeout)
|
| 845 |
|
|
break;
|
| 846 |
|
|
if (file->f_flags & O_NONBLOCK) {
|
| 847 |
|
|
retval = -EAGAIN;
|
| 848 |
|
|
break;
|
| 849 |
|
|
}
|
| 850 |
|
|
if (current->signal & ~current->blocked) {
|
| 851 |
|
|
retval = -ERESTARTSYS;
|
| 852 |
|
|
break;
|
| 853 |
|
|
}
|
| 854 |
|
|
schedule();
|
| 855 |
|
|
continue;
|
| 856 |
|
|
}
|
| 857 |
|
|
current->state = TASK_RUNNING;
|
| 858 |
|
|
|
| 859 |
|
|
/* Deal with packet mode. */
|
| 860 |
|
|
if (tty->packet && b == buf) {
|
| 861 |
|
|
put_user(TIOCPKT_DATA, b++);
|
| 862 |
|
|
nr--;
|
| 863 |
|
|
}
|
| 864 |
|
|
|
| 865 |
|
|
if (L_ICANON(tty)) {
|
| 866 |
|
|
while (1) {
|
| 867 |
|
|
int eol;
|
| 868 |
|
|
|
| 869 |
|
|
disable_bh(TQUEUE_BH);
|
| 870 |
|
|
if (!tty->read_cnt) {
|
| 871 |
|
|
enable_bh(TQUEUE_BH);
|
| 872 |
|
|
break;
|
| 873 |
|
|
}
|
| 874 |
|
|
eol = clear_bit(tty->read_tail,
|
| 875 |
|
|
&tty->read_flags);
|
| 876 |
|
|
c = tty->read_buf[tty->read_tail];
|
| 877 |
|
|
tty->read_tail = ((tty->read_tail+1) &
|
| 878 |
|
|
(N_TTY_BUF_SIZE-1));
|
| 879 |
|
|
tty->read_cnt--;
|
| 880 |
|
|
enable_bh(TQUEUE_BH);
|
| 881 |
|
|
if (!eol) {
|
| 882 |
|
|
put_user(c, b++);
|
| 883 |
|
|
if (--nr)
|
| 884 |
|
|
continue;
|
| 885 |
|
|
break;
|
| 886 |
|
|
}
|
| 887 |
|
|
if (--tty->canon_data < 0) {
|
| 888 |
|
|
tty->canon_data = 0;
|
| 889 |
|
|
}
|
| 890 |
|
|
if (c != __DISABLED_CHAR) {
|
| 891 |
|
|
put_user(c, b++);
|
| 892 |
|
|
nr--;
|
| 893 |
|
|
}
|
| 894 |
|
|
break;
|
| 895 |
|
|
}
|
| 896 |
|
|
} else {
|
| 897 |
|
|
disable_bh(TQUEUE_BH);
|
| 898 |
|
|
copy_from_read_buf(tty, &b, &nr);
|
| 899 |
|
|
copy_from_read_buf(tty, &b, &nr);
|
| 900 |
|
|
enable_bh(TQUEUE_BH);
|
| 901 |
|
|
}
|
| 902 |
|
|
|
| 903 |
|
|
/* If there is enough space in the read buffer now, let the
|
| 904 |
|
|
low-level driver know. */
|
| 905 |
|
|
if (tty->driver.unthrottle &&
|
| 906 |
|
|
(tty->read_cnt <= TTY_THRESHOLD_UNTHROTTLE)
|
| 907 |
|
|
&& clear_bit(TTY_THROTTLED, &tty->flags))
|
| 908 |
|
|
tty->driver.unthrottle(tty);
|
| 909 |
|
|
|
| 910 |
|
|
if (b - buf >= minimum || !nr)
|
| 911 |
|
|
break;
|
| 912 |
|
|
if (time)
|
| 913 |
|
|
current->timeout = time + jiffies;
|
| 914 |
|
|
}
|
| 915 |
|
|
remove_wait_queue(&tty->read_wait, &wait);
|
| 916 |
|
|
|
| 917 |
|
|
if (!waitqueue_active(&tty->read_wait))
|
| 918 |
|
|
tty->minimum_to_wake = minimum;
|
| 919 |
|
|
|
| 920 |
|
|
current->state = TASK_RUNNING;
|
| 921 |
|
|
current->timeout = 0;
|
| 922 |
|
|
size = b - buf;
|
| 923 |
|
|
if (size && nr)
|
| 924 |
|
|
clear_bit(TTY_PUSH, &tty->flags);
|
| 925 |
|
|
if (!size && clear_bit(TTY_PUSH, &tty->flags))
|
| 926 |
|
|
goto do_it_again;
|
| 927 |
|
|
if (!size && !retval)
|
| 928 |
|
|
clear_bit(TTY_PUSH, &tty->flags);
|
| 929 |
|
|
return (size ? size : retval);
|
| 930 |
|
|
}
|
| 931 |
|
|
|
| 932 |
|
|
static int write_chan(struct tty_struct * tty, struct file * file,
|
| 933 |
|
|
const unsigned char * buf, unsigned int nr)
|
| 934 |
|
|
{
|
| 935 |
|
|
struct wait_queue wait = { current, NULL };
|
| 936 |
|
|
int c;
|
| 937 |
|
|
const unsigned char *b = buf;
|
| 938 |
|
|
int retval = 0;
|
| 939 |
|
|
|
| 940 |
|
|
/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
|
| 941 |
|
|
if (L_TOSTOP(tty) && file->f_inode->i_rdev != CONSOLE_DEV) {
|
| 942 |
|
|
retval = tty_check_change(tty);
|
| 943 |
|
|
if (retval)
|
| 944 |
|
|
return retval;
|
| 945 |
|
|
}
|
| 946 |
|
|
|
| 947 |
|
|
add_wait_queue(&tty->write_wait, &wait);
|
| 948 |
|
|
while (1) {
|
| 949 |
|
|
current->state = TASK_INTERRUPTIBLE;
|
| 950 |
|
|
if (current->signal & ~current->blocked) {
|
| 951 |
|
|
retval = -ERESTARTSYS;
|
| 952 |
|
|
break;
|
| 953 |
|
|
}
|
| 954 |
|
|
if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
|
| 955 |
|
|
retval = -EIO;
|
| 956 |
|
|
break;
|
| 957 |
|
|
}
|
| 958 |
|
|
if (O_OPOST(tty)) {
|
| 959 |
|
|
while (nr > 0) {
|
| 960 |
|
|
c = get_user(b);
|
| 961 |
|
|
if (opost(c, tty) < 0)
|
| 962 |
|
|
break;
|
| 963 |
|
|
b++; nr--;
|
| 964 |
|
|
}
|
| 965 |
|
|
if (tty->driver.flush_chars)
|
| 966 |
|
|
tty->driver.flush_chars(tty);
|
| 967 |
|
|
} else {
|
| 968 |
|
|
c = tty->driver.write(tty, 1, b, nr);
|
| 969 |
|
|
b += c;
|
| 970 |
|
|
nr -= c;
|
| 971 |
|
|
}
|
| 972 |
|
|
if (!nr)
|
| 973 |
|
|
break;
|
| 974 |
|
|
if (file->f_flags & O_NONBLOCK) {
|
| 975 |
|
|
retval = -EAGAIN;
|
| 976 |
|
|
break;
|
| 977 |
|
|
}
|
| 978 |
|
|
schedule();
|
| 979 |
|
|
}
|
| 980 |
|
|
current->state = TASK_RUNNING;
|
| 981 |
|
|
remove_wait_queue(&tty->write_wait, &wait);
|
| 982 |
|
|
return (b - buf) ? b - buf : retval;
|
| 983 |
|
|
}
|
| 984 |
|
|
|
| 985 |
|
|
static int normal_select(struct tty_struct * tty, struct inode * inode,
|
| 986 |
|
|
struct file * file, int sel_type, select_table *wait)
|
| 987 |
|
|
{
|
| 988 |
|
|
switch (sel_type) {
|
| 989 |
|
|
case SEL_IN:
|
| 990 |
|
|
if (input_available_p(tty, TIME_CHAR(tty) ? 0 :
|
| 991 |
|
|
MIN_CHAR(tty)))
|
| 992 |
|
|
return 1;
|
| 993 |
|
|
/* fall through */
|
| 994 |
|
|
case SEL_EX:
|
| 995 |
|
|
if (tty->packet && tty->link->ctrl_status)
|
| 996 |
|
|
return 1;
|
| 997 |
|
|
if (tty->flags & (1 << TTY_OTHER_CLOSED))
|
| 998 |
|
|
return 1;
|
| 999 |
|
|
if (tty_hung_up_p(file))
|
| 1000 |
|
|
return 1;
|
| 1001 |
|
|
if (!waitqueue_active(&tty->read_wait)) {
|
| 1002 |
|
|
if (MIN_CHAR(tty) && !TIME_CHAR(tty))
|
| 1003 |
|
|
tty->minimum_to_wake = MIN_CHAR(tty);
|
| 1004 |
|
|
else
|
| 1005 |
|
|
tty->minimum_to_wake = 1;
|
| 1006 |
|
|
}
|
| 1007 |
|
|
select_wait(&tty->read_wait, wait);
|
| 1008 |
|
|
return 0;
|
| 1009 |
|
|
case SEL_OUT:
|
| 1010 |
|
|
if (tty->driver.chars_in_buffer(tty) < WAKEUP_CHARS)
|
| 1011 |
|
|
return 1;
|
| 1012 |
|
|
select_wait(&tty->write_wait, wait);
|
| 1013 |
|
|
return 0;
|
| 1014 |
|
|
}
|
| 1015 |
|
|
return 0;
|
| 1016 |
|
|
}
|
| 1017 |
|
|
|
| 1018 |
|
|
struct tty_ldisc tty_ldisc_N_TTY = {
|
| 1019 |
|
|
TTY_LDISC_MAGIC, /* magic */
|
| 1020 |
|
|
0, /* num */
|
| 1021 |
|
|
0, /* flags */
|
| 1022 |
|
|
n_tty_open, /* open */
|
| 1023 |
|
|
n_tty_close, /* close */
|
| 1024 |
|
|
n_tty_flush_buffer, /* flush_buffer */
|
| 1025 |
|
|
n_tty_chars_in_buffer, /* chars_in_buffer */
|
| 1026 |
|
|
read_chan, /* read */
|
| 1027 |
|
|
write_chan, /* write */
|
| 1028 |
|
|
n_tty_ioctl, /* ioctl */
|
| 1029 |
|
|
n_tty_set_termios, /* set_termios */
|
| 1030 |
|
|
normal_select, /* select */
|
| 1031 |
|
|
n_tty_receive_buf, /* receive_buf */
|
| 1032 |
|
|
n_tty_receive_room, /* receive_room */
|
| 1033 |
|
|
|
| 1034 |
|
|
};
|
| 1035 |
|
|
|
