Greg Kroah-Hartman | e3b3d0f | 2017-11-06 18:11:51 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-1.0+ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * n_tty.c --- implements the N_TTY line discipline. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 4 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * This code used to be in tty_io.c, but things are getting hairy |
| 6 | * enough that it made sense to split things off. (The N_TTY |
| 7 | * processing has changed so much that it's hardly recognizable, |
| 8 | * anyway...) |
| 9 | * |
| 10 | * Note that the open routine for N_TTY is guaranteed never to return |
| 11 | * an error. This is because Linux will fall back to setting a line |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 12 | * to N_TTY if it can not switch to any other line discipline. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | * |
| 14 | * Written by Theodore Ts'o, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 15 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | * This file also contains code originally written by Linus Torvalds, |
| 17 | * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 18 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | * Reduced memory usage for older ARM systems - Russell King. |
| 20 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 21 | * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu> |
| 23 | * who actually finally proved there really was a race. |
| 24 | * |
| 25 | * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to |
| 26 | * waiting writing processes-Sapan Bhatia <sapan@corewars.org>. |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 27 | * Also fixed a bug in BLOCKING mode where n_tty_write returns |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | * EAGAIN |
| 29 | */ |
| 30 | |
| 31 | #include <linux/types.h> |
| 32 | #include <linux/major.h> |
| 33 | #include <linux/errno.h> |
| 34 | #include <linux/signal.h> |
| 35 | #include <linux/fcntl.h> |
| 36 | #include <linux/sched.h> |
| 37 | #include <linux/interrupt.h> |
| 38 | #include <linux/tty.h> |
| 39 | #include <linux/timer.h> |
| 40 | #include <linux/ctype.h> |
| 41 | #include <linux/mm.h> |
| 42 | #include <linux/string.h> |
| 43 | #include <linux/slab.h> |
| 44 | #include <linux/poll.h> |
| 45 | #include <linux/bitops.h> |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 46 | #include <linux/audit.h> |
| 47 | #include <linux/file.h> |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 48 | #include <linux/uaccess.h> |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 49 | #include <linux/module.h> |
George Spelvin | 593fb1ae4 | 2013-02-12 02:00:43 -0500 | [diff] [blame] | 50 | #include <linux/ratelimit.h> |
Peter Hurley | 86e35ae | 2013-07-24 09:30:05 -0400 | [diff] [blame] | 51 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | /* number of characters left in xmit buffer before select has we have room */ |
| 55 | #define WAKEUP_CHARS 256 |
| 56 | |
| 57 | /* |
| 58 | * This defines the low- and high-watermarks for throttling and |
| 59 | * unthrottling the TTY driver. These watermarks are used for |
| 60 | * controlling the space in the read buffer. |
| 61 | */ |
| 62 | #define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */ |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 63 | #define TTY_THRESHOLD_UNTHROTTLE 128 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 65 | /* |
| 66 | * Special byte codes used in the echo buffer to represent operations |
| 67 | * or special handling of characters. Bytes in the echo buffer that |
| 68 | * are not part of such special blocks are treated as normal character |
| 69 | * codes. |
| 70 | */ |
| 71 | #define ECHO_OP_START 0xff |
| 72 | #define ECHO_OP_MOVE_BACK_COL 0x80 |
| 73 | #define ECHO_OP_SET_CANON_COL 0x81 |
| 74 | #define ECHO_OP_ERASE_TAB 0x82 |
| 75 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 76 | #define ECHO_COMMIT_WATERMARK 256 |
| 77 | #define ECHO_BLOCK 256 |
| 78 | #define ECHO_DISCARD_WATERMARK N_TTY_BUF_SIZE - (ECHO_BLOCK + 32) |
| 79 | |
| 80 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 81 | #undef N_TTY_TRACE |
| 82 | #ifdef N_TTY_TRACE |
| 83 | # define n_tty_trace(f, args...) trace_printk(f, ##args) |
| 84 | #else |
| 85 | # define n_tty_trace(f, args...) |
| 86 | #endif |
| 87 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 88 | struct n_tty_data { |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 89 | /* producer-published */ |
| 90 | size_t read_head; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 91 | size_t commit_head; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 92 | size_t canon_head; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 93 | size_t echo_head; |
| 94 | size_t echo_commit; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 95 | size_t echo_mark; |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 96 | DECLARE_BITMAP(char_map, 256); |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 97 | |
| 98 | /* private to n_tty_receive_overrun (single-threaded) */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 99 | unsigned long overrun_time; |
| 100 | int num_overrun; |
| 101 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 102 | /* non-atomic */ |
| 103 | bool no_room; |
| 104 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 105 | /* must hold exclusive termios_rwsem to reset these */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 106 | unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1; |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 107 | unsigned char push:1; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 108 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 109 | /* shared by producer and consumer */ |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 110 | char read_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 111 | DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 112 | unsigned char echo_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 113 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 114 | /* consumer-published */ |
| 115 | size_t read_tail; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 116 | size_t line_start; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 117 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 118 | /* protected by output lock */ |
| 119 | unsigned int column; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 120 | unsigned int canon_column; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 121 | size_t echo_tail; |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 122 | |
| 123 | struct mutex atomic_read_lock; |
| 124 | struct mutex output_lock; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 125 | }; |
| 126 | |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 127 | static inline size_t read_cnt(struct n_tty_data *ldata) |
| 128 | { |
Peter Hurley | a2f73be | 2013-06-15 09:14:22 -0400 | [diff] [blame] | 129 | return ldata->read_head - ldata->read_tail; |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 130 | } |
| 131 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 132 | static inline unsigned char read_buf(struct n_tty_data *ldata, size_t i) |
| 133 | { |
| 134 | return ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 135 | } |
| 136 | |
| 137 | static inline unsigned char *read_buf_addr(struct n_tty_data *ldata, size_t i) |
| 138 | { |
| 139 | return &ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 140 | } |
| 141 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 142 | static inline unsigned char echo_buf(struct n_tty_data *ldata, size_t i) |
| 143 | { |
| 144 | return ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 145 | } |
| 146 | |
| 147 | static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i) |
| 148 | { |
| 149 | return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 150 | } |
| 151 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 152 | static int tty_copy_to_user(struct tty_struct *tty, void __user *to, |
| 153 | size_t tail, size_t n) |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 154 | { |
| 155 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 156 | size_t size = N_TTY_BUF_SIZE - tail; |
| 157 | const void *from = read_buf_addr(ldata, tail); |
| 158 | int uncopied; |
| 159 | |
| 160 | if (n > size) { |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 161 | tty_audit_add_data(tty, from, size); |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 162 | uncopied = copy_to_user(to, from, size); |
| 163 | if (uncopied) |
| 164 | return uncopied; |
| 165 | to += size; |
| 166 | n -= size; |
| 167 | from = ldata->read_buf; |
| 168 | } |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 169 | |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 170 | tty_audit_add_data(tty, from, n); |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 171 | return copy_to_user(to, from, n); |
| 172 | } |
| 173 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 174 | /** |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 175 | * n_tty_kick_worker - start input worker (if required) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 176 | * @tty: terminal |
| 177 | * |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 178 | * Re-schedules the flip buffer work if it may have stopped |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 179 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 180 | * Caller holds exclusive termios_rwsem |
| 181 | * or |
| 182 | * n_tty_read()/consumer path: |
| 183 | * holds non-exclusive termios_rwsem |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 184 | */ |
| 185 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 186 | static void n_tty_kick_worker(struct tty_struct *tty) |
Peter Hurley | 7879a9f | 2013-06-15 07:28:31 -0400 | [diff] [blame] | 187 | { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 188 | struct n_tty_data *ldata = tty->disc_data; |
| 189 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 190 | /* Did the input worker stop? Restart it */ |
| 191 | if (unlikely(ldata->no_room)) { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 192 | ldata->no_room = 0; |
| 193 | |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 194 | WARN_RATELIMIT(tty->port->itty == NULL, |
Sasha Levin | cadf748 | 2012-10-25 14:26:35 -0400 | [diff] [blame] | 195 | "scheduling with invalid itty\n"); |
Peter Hurley | 2162293 | 2013-03-11 16:44:21 -0400 | [diff] [blame] | 196 | /* see if ldisc has been killed - if so, this means that |
| 197 | * even though the ldisc has been halted and ->buf.work |
| 198 | * cancelled, ->buf.work is about to be rescheduled |
| 199 | */ |
| 200 | WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags), |
| 201 | "scheduling buffer work for halted ldisc\n"); |
Peter Hurley | e176058 | 2015-10-17 16:36:23 -0400 | [diff] [blame] | 202 | tty_buffer_restart_work(tty->port); |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 203 | } |
Linus Torvalds | 55db4c6 | 2011-06-04 06:33:24 +0900 | [diff] [blame] | 204 | } |
| 205 | |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 206 | static ssize_t chars_in_buffer(struct tty_struct *tty) |
| 207 | { |
| 208 | struct n_tty_data *ldata = tty->disc_data; |
| 209 | ssize_t n = 0; |
| 210 | |
| 211 | if (!ldata->icanon) |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 212 | n = ldata->commit_head - ldata->read_tail; |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 213 | else |
| 214 | n = ldata->canon_head - ldata->read_tail; |
| 215 | return n; |
| 216 | } |
| 217 | |
Peter Hurley | ee0bab8 | 2013-06-15 09:14:34 -0400 | [diff] [blame] | 218 | /** |
| 219 | * n_tty_write_wakeup - asynchronous I/O notifier |
| 220 | * @tty: tty device |
| 221 | * |
| 222 | * Required for the ptys, serial driver etc. since processes |
| 223 | * that attach themselves to the master and rely on ASYNC |
| 224 | * IO must be woken up |
| 225 | */ |
| 226 | |
| 227 | static void n_tty_write_wakeup(struct tty_struct *tty) |
| 228 | { |
Peter Hurley | 7bccc36 | 2016-01-09 21:45:12 -0800 | [diff] [blame] | 229 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
| 230 | kill_fasync(&tty->fasync, SIGIO, POLL_OUT); |
Peter Hurley | ee0bab8 | 2013-06-15 09:14:34 -0400 | [diff] [blame] | 231 | } |
| 232 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 233 | static void n_tty_check_throttle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 234 | { |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 235 | struct n_tty_data *ldata = tty->disc_data; |
| 236 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 237 | /* |
| 238 | * Check the remaining room for the input canonicalization |
| 239 | * mode. We don't want to throttle the driver if we're in |
| 240 | * canonical mode and don't have a newline yet! |
| 241 | */ |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 242 | if (ldata->icanon && ldata->canon_head == ldata->read_tail) |
| 243 | return; |
| 244 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 245 | while (1) { |
| 246 | int throttled; |
| 247 | tty_set_flow_change(tty, TTY_THROTTLE_SAFE); |
Peter Hurley | 5e28cca | 2015-01-16 15:05:36 -0500 | [diff] [blame] | 248 | if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 249 | break; |
| 250 | throttled = tty_throttle_safe(tty); |
| 251 | if (!throttled) |
| 252 | break; |
| 253 | } |
| 254 | __tty_set_flow_change(tty, 0); |
| 255 | } |
| 256 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 257 | static void n_tty_check_unthrottle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 258 | { |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 259 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 260 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 261 | return; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 262 | n_tty_kick_worker(tty); |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 263 | tty_wakeup(tty->link); |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 264 | return; |
| 265 | } |
| 266 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 267 | /* If there is enough space in the read buffer now, let the |
| 268 | * low-level driver know. We use chars_in_buffer() to |
| 269 | * check the buffer, as it now knows about canonical mode. |
| 270 | * Otherwise, if the driver is throttled and the line is |
| 271 | * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, |
| 272 | * we won't get any more characters. |
| 273 | */ |
| 274 | |
| 275 | while (1) { |
| 276 | int unthrottled; |
| 277 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 278 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 279 | break; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 280 | n_tty_kick_worker(tty); |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 281 | unthrottled = tty_unthrottle_safe(tty); |
| 282 | if (!unthrottled) |
| 283 | break; |
| 284 | } |
| 285 | __tty_set_flow_change(tty, 0); |
| 286 | } |
| 287 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 288 | /** |
| 289 | * put_tty_queue - add character to tty |
| 290 | * @c: character |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 291 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 292 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 293 | * Add a character to the tty read_buf queue. |
| 294 | * |
| 295 | * n_tty_receive_buf()/producer path: |
| 296 | * caller holds non-exclusive termios_rwsem |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 297 | */ |
| 298 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 299 | static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | { |
Christian Riesch | 8bfbe2d | 2014-11-13 05:53:26 +0100 | [diff] [blame] | 301 | *read_buf_addr(ldata, ldata->read_head) = c; |
| 302 | ldata->read_head++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | } |
| 304 | |
| 305 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | * reset_buffer_flags - reset buffer state |
| 307 | * @tty: terminal to reset |
| 308 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 309 | * Reset the read buffer counters and clear the flags. |
| 310 | * Called from n_tty_open() and n_tty_flush_buffer(). |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 311 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 312 | * Locking: caller holds exclusive termios_rwsem |
| 313 | * (or locking is not required) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 315 | |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 316 | static void reset_buffer_flags(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | { |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 318 | ldata->read_head = ldata->canon_head = ldata->read_tail = 0; |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 319 | ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 320 | ldata->commit_head = 0; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 321 | ldata->echo_mark = 0; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 322 | ldata->line_start = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 323 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 324 | ldata->erasing = 0; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 325 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 326 | ldata->push = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | } |
| 328 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 329 | static void n_tty_packet_mode_flush(struct tty_struct *tty) |
| 330 | { |
| 331 | unsigned long flags; |
| 332 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 333 | if (tty->link->packet) { |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 334 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 335 | tty->ctrl_status |= TIOCPKT_FLUSHREAD; |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 336 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 337 | wake_up_interruptible(&tty->link->read_wait); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 338 | } |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 339 | } |
| 340 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | /** |
| 342 | * n_tty_flush_buffer - clean input queue |
| 343 | * @tty: terminal device |
| 344 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 345 | * Flush the input buffer. Called when the tty layer wants the |
| 346 | * buffer flushed (eg at hangup) or when the N_TTY line discipline |
| 347 | * internally has to clean the pending queue (for example some signals). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 349 | * Holds termios_rwsem to exclude producer/consumer while |
| 350 | * buffer indices are reset. |
| 351 | * |
| 352 | * Locking: ctrl_lock, exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 354 | |
| 355 | static void n_tty_flush_buffer(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | { |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 357 | down_write(&tty->termios_rwsem); |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 358 | reset_buffer_flags(tty->disc_data); |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 359 | n_tty_kick_worker(tty); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 360 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 361 | if (tty->link) |
| 362 | n_tty_packet_mode_flush(tty); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 363 | up_write(&tty->termios_rwsem); |
| 364 | } |
| 365 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | * is_utf8_continuation - utf8 multibyte check |
| 368 | * @c: byte to check |
| 369 | * |
| 370 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 371 | * character. We use this to correctly compute the on screen size |
| 372 | * of the character when printing |
| 373 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 374 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | static inline int is_utf8_continuation(unsigned char c) |
| 376 | { |
| 377 | return (c & 0xc0) == 0x80; |
| 378 | } |
| 379 | |
| 380 | /** |
| 381 | * is_continuation - multibyte check |
| 382 | * @c: byte to check |
| 383 | * |
| 384 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 385 | * character and the terminal is in unicode mode. |
| 386 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | static inline int is_continuation(unsigned char c, struct tty_struct *tty) |
| 389 | { |
| 390 | return I_IUTF8(tty) && is_utf8_continuation(c); |
| 391 | } |
| 392 | |
| 393 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 394 | * do_output_char - output one character |
| 395 | * @c: character (or partial unicode symbol) |
| 396 | * @tty: terminal device |
| 397 | * @space: space available in tty driver write buffer |
| 398 | * |
| 399 | * This is a helper function that handles one output character |
| 400 | * (including special characters like TAB, CR, LF, etc.), |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 401 | * doing OPOST processing and putting the results in the |
| 402 | * tty driver's write buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 403 | * |
| 404 | * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY |
| 405 | * and NLDLY. They simply aren't relevant in the world today. |
| 406 | * If you ever need them, add them here. |
| 407 | * |
| 408 | * Returns the number of bytes of buffer space used or -1 if |
| 409 | * no space left. |
| 410 | * |
| 411 | * Locking: should be called under the output_lock to protect |
| 412 | * the column state and space left in the buffer |
| 413 | */ |
| 414 | |
| 415 | static int do_output_char(unsigned char c, struct tty_struct *tty, int space) |
| 416 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 417 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 418 | int spaces; |
| 419 | |
| 420 | if (!space) |
| 421 | return -1; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 422 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 423 | switch (c) { |
| 424 | case '\n': |
| 425 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 426 | ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 427 | if (O_ONLCR(tty)) { |
| 428 | if (space < 2) |
| 429 | return -1; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 430 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 37f81fa | 2009-09-05 12:46:07 -0700 | [diff] [blame] | 431 | tty->ops->write(tty, "\r\n", 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 432 | return 2; |
| 433 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 434 | ldata->canon_column = ldata->column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 435 | break; |
| 436 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 437 | if (O_ONOCR(tty) && ldata->column == 0) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 438 | return 0; |
| 439 | if (O_OCRNL(tty)) { |
| 440 | c = '\n'; |
| 441 | if (O_ONLRET(tty)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 442 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 443 | break; |
| 444 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 445 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 446 | break; |
| 447 | case '\t': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 448 | spaces = 8 - (ldata->column & 7); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 449 | if (O_TABDLY(tty) == XTABS) { |
| 450 | if (space < spaces) |
| 451 | return -1; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 452 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 453 | tty->ops->write(tty, " ", spaces); |
| 454 | return spaces; |
| 455 | } |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 456 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 457 | break; |
| 458 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 459 | if (ldata->column > 0) |
| 460 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 461 | break; |
| 462 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 463 | if (!iscntrl(c)) { |
| 464 | if (O_OLCUC(tty)) |
| 465 | c = toupper(c); |
| 466 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 467 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 468 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 469 | break; |
| 470 | } |
| 471 | |
| 472 | tty_put_char(tty, c); |
| 473 | return 1; |
| 474 | } |
| 475 | |
| 476 | /** |
| 477 | * process_output - output post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | * @c: character (or partial unicode symbol) |
| 479 | * @tty: terminal device |
| 480 | * |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 481 | * Output one character with OPOST processing. |
| 482 | * Returns -1 when the output device is full and the character |
| 483 | * must be retried. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 485 | * Locking: output_lock to protect column state and space left |
| 486 | * (also, this is called from n_tty_write under the |
| 487 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 489 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 490 | static int process_output(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | { |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 492 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 493 | int space, retval; |
| 494 | |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 495 | mutex_lock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 497 | space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 498 | retval = do_output_char(c, tty, space); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 500 | mutex_unlock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 501 | if (retval < 0) |
| 502 | return -1; |
| 503 | else |
| 504 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | } |
| 506 | |
| 507 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 508 | * process_output_block - block post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | * @tty: terminal device |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 510 | * @buf: character buffer |
| 511 | * @nr: number of bytes to output |
| 512 | * |
| 513 | * Output a block of characters with OPOST processing. |
| 514 | * Returns the number of characters output. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | * |
| 516 | * This path is used to speed up block console writes, among other |
| 517 | * things when processing blocks of output data. It handles only |
| 518 | * the simple cases normally found and helps to generate blocks of |
| 519 | * symbols for the console driver and thus improve performance. |
| 520 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 521 | * Locking: output_lock to protect column state and space left |
| 522 | * (also, this is called from n_tty_write under the |
| 523 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 525 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 526 | static ssize_t process_output_block(struct tty_struct *tty, |
| 527 | const unsigned char *buf, unsigned int nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 529 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | int space; |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 531 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | const unsigned char *cp; |
| 533 | |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 534 | mutex_lock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 535 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 536 | space = tty_write_room(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 537 | if (!space) { |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 538 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | return 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 540 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | if (nr > space) |
| 542 | nr = space; |
| 543 | |
| 544 | for (i = 0, cp = buf; i < nr; i++, cp++) { |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 545 | unsigned char c = *cp; |
| 546 | |
| 547 | switch (c) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | case '\n': |
| 549 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 550 | ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | if (O_ONLCR(tty)) |
| 552 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 553 | ldata->canon_column = ldata->column; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | break; |
| 555 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 556 | if (O_ONOCR(tty) && ldata->column == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | goto break_out; |
| 558 | if (O_OCRNL(tty)) |
| 559 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 560 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | break; |
| 562 | case '\t': |
| 563 | goto break_out; |
| 564 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 565 | if (ldata->column > 0) |
| 566 | ldata->column--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | break; |
| 568 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 569 | if (!iscntrl(c)) { |
| 570 | if (O_OLCUC(tty)) |
| 571 | goto break_out; |
| 572 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 573 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 574 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | break; |
| 576 | } |
| 577 | } |
| 578 | break_out: |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 579 | i = tty->ops->write(tty, buf, i); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 580 | |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 581 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | return i; |
| 583 | } |
| 584 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 585 | /** |
| 586 | * process_echoes - write pending echo characters |
| 587 | * @tty: terminal device |
| 588 | * |
| 589 | * Write previously buffered echo (and other ldisc-generated) |
| 590 | * characters to the tty. |
| 591 | * |
| 592 | * Characters generated by the ldisc (including echoes) need to |
| 593 | * be buffered because the driver's write buffer can fill during |
| 594 | * heavy program output. Echoing straight to the driver will |
| 595 | * often fail under these conditions, causing lost characters and |
| 596 | * resulting mismatches of ldisc state information. |
| 597 | * |
| 598 | * Since the ldisc state must represent the characters actually sent |
| 599 | * to the driver at the time of the write, operations like certain |
| 600 | * changes in column state are also saved in the buffer and executed |
| 601 | * here. |
| 602 | * |
| 603 | * A circular fifo buffer is used so that the most recent characters |
| 604 | * are prioritized. Also, when control characters are echoed with a |
| 605 | * prefixed "^", the pair is treated atomically and thus not separated. |
| 606 | * |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 607 | * Locking: callers must hold output_lock |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 608 | */ |
| 609 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 610 | static size_t __process_echoes(struct tty_struct *tty) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 611 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 612 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 613 | int space, old_space; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 614 | size_t tail; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 615 | unsigned char c; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 616 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 617 | old_space = space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 618 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 619 | tail = ldata->echo_tail; |
Peter Hurley | 29c7c5c | 2013-06-15 10:04:28 -0400 | [diff] [blame] | 620 | while (ldata->echo_commit != tail) { |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 621 | c = echo_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 622 | if (c == ECHO_OP_START) { |
| 623 | unsigned char op; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 624 | int no_space_left = 0; |
| 625 | |
| 626 | /* |
| 627 | * If the buffer byte is the start of a multi-byte |
| 628 | * operation, get the next byte, which is either the |
| 629 | * op code or a control character value. |
| 630 | */ |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 631 | op = echo_buf(ldata, tail + 1); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 632 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 633 | switch (op) { |
| 634 | unsigned int num_chars, num_bs; |
| 635 | |
| 636 | case ECHO_OP_ERASE_TAB: |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 637 | num_chars = echo_buf(ldata, tail + 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 638 | |
| 639 | /* |
| 640 | * Determine how many columns to go back |
| 641 | * in order to erase the tab. |
| 642 | * This depends on the number of columns |
| 643 | * used by other characters within the tab |
| 644 | * area. If this (modulo 8) count is from |
| 645 | * the start of input rather than from a |
| 646 | * previous tab, we offset by canon column. |
| 647 | * Otherwise, tab spacing is normal. |
| 648 | */ |
| 649 | if (!(num_chars & 0x80)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 650 | num_chars += ldata->canon_column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 651 | num_bs = 8 - (num_chars & 7); |
| 652 | |
| 653 | if (num_bs > space) { |
| 654 | no_space_left = 1; |
| 655 | break; |
| 656 | } |
| 657 | space -= num_bs; |
| 658 | while (num_bs--) { |
| 659 | tty_put_char(tty, '\b'); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 660 | if (ldata->column > 0) |
| 661 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 662 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 663 | tail += 3; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 664 | break; |
| 665 | |
| 666 | case ECHO_OP_SET_CANON_COL: |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 667 | ldata->canon_column = ldata->column; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 668 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 669 | break; |
| 670 | |
| 671 | case ECHO_OP_MOVE_BACK_COL: |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 672 | if (ldata->column > 0) |
| 673 | ldata->column--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 674 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 675 | break; |
| 676 | |
| 677 | case ECHO_OP_START: |
| 678 | /* This is an escaped echo op start code */ |
| 679 | if (!space) { |
| 680 | no_space_left = 1; |
| 681 | break; |
| 682 | } |
| 683 | tty_put_char(tty, ECHO_OP_START); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 684 | ldata->column++; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 685 | space--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 686 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 687 | break; |
| 688 | |
| 689 | default: |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 690 | /* |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 691 | * If the op is not a special byte code, |
| 692 | * it is a ctrl char tagged to be echoed |
| 693 | * as "^X" (where X is the letter |
| 694 | * representing the control char). |
| 695 | * Note that we must ensure there is |
| 696 | * enough space for the whole ctrl pair. |
| 697 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 698 | */ |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 699 | if (space < 2) { |
| 700 | no_space_left = 1; |
| 701 | break; |
| 702 | } |
| 703 | tty_put_char(tty, '^'); |
| 704 | tty_put_char(tty, op ^ 0100); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 705 | ldata->column += 2; |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 706 | space -= 2; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 707 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 708 | } |
| 709 | |
| 710 | if (no_space_left) |
| 711 | break; |
| 712 | } else { |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 713 | if (O_OPOST(tty)) { |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 714 | int retval = do_output_char(c, tty, space); |
| 715 | if (retval < 0) |
| 716 | break; |
| 717 | space -= retval; |
| 718 | } else { |
| 719 | if (!space) |
| 720 | break; |
| 721 | tty_put_char(tty, c); |
| 722 | space -= 1; |
| 723 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 724 | tail += 1; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 725 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 726 | } |
| 727 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 728 | /* If the echo buffer is nearly full (so that the possibility exists |
| 729 | * of echo overrun before the next commit), then discard enough |
| 730 | * data at the tail to prevent a subsequent overrun */ |
| 731 | while (ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) { |
Roel Kluin | c476f65 | 2013-10-11 22:08:49 +0200 | [diff] [blame] | 732 | if (echo_buf(ldata, tail) == ECHO_OP_START) { |
Peter Hurley | 6f22253 | 2013-11-08 09:42:18 -0500 | [diff] [blame] | 733 | if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 734 | tail += 3; |
| 735 | else |
| 736 | tail += 2; |
| 737 | } else |
| 738 | tail++; |
| 739 | } |
| 740 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 741 | ldata->echo_tail = tail; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 742 | return old_space - space; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 743 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 745 | static void commit_echoes(struct tty_struct *tty) |
| 746 | { |
| 747 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 748 | size_t nr, old, echoed; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 749 | size_t head; |
| 750 | |
| 751 | head = ldata->echo_head; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 752 | ldata->echo_mark = head; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 753 | old = ldata->echo_commit - ldata->echo_tail; |
| 754 | |
| 755 | /* Process committed echoes if the accumulated # of bytes |
| 756 | * is over the threshold (and try again each time another |
| 757 | * block is accumulated) */ |
| 758 | nr = head - ldata->echo_tail; |
| 759 | if (nr < ECHO_COMMIT_WATERMARK || (nr % ECHO_BLOCK > old % ECHO_BLOCK)) |
| 760 | return; |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 761 | |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 762 | mutex_lock(&ldata->output_lock); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 763 | ldata->echo_commit = head; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 764 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 765 | mutex_unlock(&ldata->output_lock); |
| 766 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 767 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 768 | tty->ops->flush_chars(tty); |
| 769 | } |
| 770 | |
| 771 | static void process_echoes(struct tty_struct *tty) |
| 772 | { |
| 773 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 774 | size_t echoed; |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 775 | |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 776 | if (ldata->echo_mark == ldata->echo_tail) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 777 | return; |
| 778 | |
| 779 | mutex_lock(&ldata->output_lock); |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 780 | ldata->echo_commit = ldata->echo_mark; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 781 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 782 | mutex_unlock(&ldata->output_lock); |
| 783 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 784 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 785 | tty->ops->flush_chars(tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 786 | } |
| 787 | |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 788 | /* NB: echo_mark and echo_head should be equivalent here */ |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 789 | static void flush_echoes(struct tty_struct *tty) |
| 790 | { |
| 791 | struct n_tty_data *ldata = tty->disc_data; |
| 792 | |
Peter Hurley | 39434ab | 2013-11-29 12:56:10 -0500 | [diff] [blame] | 793 | if ((!L_ECHO(tty) && !L_ECHONL(tty)) || |
| 794 | ldata->echo_commit == ldata->echo_head) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 795 | return; |
| 796 | |
| 797 | mutex_lock(&ldata->output_lock); |
| 798 | ldata->echo_commit = ldata->echo_head; |
| 799 | __process_echoes(tty); |
| 800 | mutex_unlock(&ldata->output_lock); |
| 801 | } |
| 802 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 804 | * add_echo_byte - add a byte to the echo buffer |
| 805 | * @c: unicode byte to echo |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 806 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 807 | * |
| 808 | * Add a character or operation byte to the echo buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 809 | */ |
| 810 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 811 | static inline void add_echo_byte(unsigned char c, struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 812 | { |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 813 | *echo_buf_addr(ldata, ldata->echo_head++) = c; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 814 | } |
| 815 | |
| 816 | /** |
| 817 | * echo_move_back_col - add operation to move back a column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 818 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 819 | * |
| 820 | * Add an operation to the echo buffer to move back one column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 821 | */ |
| 822 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 823 | static void echo_move_back_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 824 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 825 | add_echo_byte(ECHO_OP_START, ldata); |
| 826 | add_echo_byte(ECHO_OP_MOVE_BACK_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 827 | } |
| 828 | |
| 829 | /** |
| 830 | * echo_set_canon_col - add operation to set the canon column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 831 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 832 | * |
| 833 | * Add an operation to the echo buffer to set the canon column |
| 834 | * to the current column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 835 | */ |
| 836 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 837 | static void echo_set_canon_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 838 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 839 | add_echo_byte(ECHO_OP_START, ldata); |
| 840 | add_echo_byte(ECHO_OP_SET_CANON_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 841 | } |
| 842 | |
| 843 | /** |
| 844 | * echo_erase_tab - add operation to erase a tab |
| 845 | * @num_chars: number of character columns already used |
| 846 | * @after_tab: true if num_chars starts after a previous tab |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 847 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 848 | * |
| 849 | * Add an operation to the echo buffer to erase a tab. |
| 850 | * |
| 851 | * Called by the eraser function, which knows how many character |
| 852 | * columns have been used since either a previous tab or the start |
| 853 | * of input. This information will be used later, along with |
| 854 | * canon column (if applicable), to go back the correct number |
| 855 | * of columns. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 856 | */ |
| 857 | |
| 858 | static void echo_erase_tab(unsigned int num_chars, int after_tab, |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 859 | struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 860 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 861 | add_echo_byte(ECHO_OP_START, ldata); |
| 862 | add_echo_byte(ECHO_OP_ERASE_TAB, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 863 | |
| 864 | /* We only need to know this modulo 8 (tab spacing) */ |
| 865 | num_chars &= 7; |
| 866 | |
| 867 | /* Set the high bit as a flag if num_chars is after a previous tab */ |
| 868 | if (after_tab) |
| 869 | num_chars |= 0x80; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 870 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 871 | add_echo_byte(num_chars, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 872 | } |
| 873 | |
| 874 | /** |
| 875 | * echo_char_raw - echo a character raw |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | * @c: unicode byte to echo |
| 877 | * @tty: terminal device |
| 878 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 879 | * Echo user input back onto the screen. This must be called only when |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 881 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 882 | * This variant does not treat control characters specially. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 883 | */ |
| 884 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 885 | static void echo_char_raw(unsigned char c, struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 886 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 887 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 888 | add_echo_byte(ECHO_OP_START, ldata); |
| 889 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 890 | } else { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 891 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 892 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 893 | } |
| 894 | |
| 895 | /** |
| 896 | * echo_char - echo a character |
| 897 | * @c: unicode byte to echo |
| 898 | * @tty: terminal device |
| 899 | * |
| 900 | * Echo user input back onto the screen. This must be called only when |
| 901 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
| 902 | * |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 903 | * This variant tags control characters to be echoed as "^X" |
| 904 | * (where X is the letter representing the control char). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | */ |
| 906 | |
| 907 | static void echo_char(unsigned char c, struct tty_struct *tty) |
| 908 | { |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 909 | struct n_tty_data *ldata = tty->disc_data; |
| 910 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 911 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 912 | add_echo_byte(ECHO_OP_START, ldata); |
| 913 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 914 | } else { |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 915 | if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 916 | add_echo_byte(ECHO_OP_START, ldata); |
| 917 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 918 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 919 | } |
| 920 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 921 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 922 | * finish_erasing - complete erase |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 923 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 924 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 925 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 926 | static inline void finish_erasing(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 928 | if (ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 929 | echo_char_raw('/', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 930 | ldata->erasing = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | } |
| 932 | } |
| 933 | |
| 934 | /** |
| 935 | * eraser - handle erase function |
| 936 | * @c: character input |
| 937 | * @tty: terminal device |
| 938 | * |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 939 | * Perform erase and necessary output when an erase character is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 940 | * present in the stream from the driver layer. Handles the complexities |
| 941 | * of UTF-8 multibyte symbols. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 942 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 943 | * n_tty_receive_buf()/producer path: |
| 944 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 946 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | static void eraser(unsigned char c, struct tty_struct *tty) |
| 948 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 949 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | enum { ERASE, WERASE, KILL } kill_type; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 951 | size_t head; |
| 952 | size_t cnt; |
| 953 | int seen_alnums; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 955 | if (ldata->read_head == ldata->canon_head) { |
Joe Peterson | 7e94b1d | 2009-01-02 13:43:40 +0000 | [diff] [blame] | 956 | /* process_output('\a', tty); */ /* what do you think? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | return; |
| 958 | } |
| 959 | if (c == ERASE_CHAR(tty)) |
| 960 | kill_type = ERASE; |
| 961 | else if (c == WERASE_CHAR(tty)) |
| 962 | kill_type = WERASE; |
| 963 | else { |
| 964 | if (!L_ECHO(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 965 | ldata->read_head = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | return; |
| 967 | } |
| 968 | if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 969 | ldata->read_head = ldata->canon_head; |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 970 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | echo_char(KILL_CHAR(tty), tty); |
| 972 | /* Add a newline if ECHOK is on and ECHOKE is off. */ |
| 973 | if (L_ECHOK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 974 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 975 | return; |
| 976 | } |
| 977 | kill_type = KILL; |
| 978 | } |
| 979 | |
| 980 | seen_alnums = 0; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 981 | while (ldata->read_head != ldata->canon_head) { |
| 982 | head = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | |
| 984 | /* erase a single possibly multibyte character */ |
| 985 | do { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 986 | head--; |
| 987 | c = read_buf(ldata, head); |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 988 | } while (is_continuation(c, tty) && head != ldata->canon_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 989 | |
| 990 | /* do not partially erase */ |
| 991 | if (is_continuation(c, tty)) |
| 992 | break; |
| 993 | |
| 994 | if (kill_type == WERASE) { |
| 995 | /* Equivalent to BSD's ALTWERASE. */ |
| 996 | if (isalnum(c) || c == '_') |
| 997 | seen_alnums++; |
| 998 | else if (seen_alnums) |
| 999 | break; |
| 1000 | } |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1001 | cnt = ldata->read_head - head; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1002 | ldata->read_head = head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | if (L_ECHO(tty)) { |
| 1004 | if (L_ECHOPRT(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1005 | if (!ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1006 | echo_char_raw('\\', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1007 | ldata->erasing = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | } |
| 1009 | /* if cnt > 1, output a multi-byte character */ |
| 1010 | echo_char(c, tty); |
| 1011 | while (--cnt > 0) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1012 | head++; |
| 1013 | echo_char_raw(read_buf(ldata, head), ldata); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1014 | echo_move_back_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | } |
| 1016 | } else if (kill_type == ERASE && !L_ECHOE(tty)) { |
| 1017 | echo_char(ERASE_CHAR(tty), tty); |
| 1018 | } else if (c == '\t') { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1019 | unsigned int num_chars = 0; |
| 1020 | int after_tab = 0; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1021 | size_t tail = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1023 | /* |
| 1024 | * Count the columns used for characters |
| 1025 | * since the start of input or after a |
| 1026 | * previous tab. |
| 1027 | * This info is used to go back the correct |
| 1028 | * number of columns. |
| 1029 | */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1030 | while (tail != ldata->canon_head) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1031 | tail--; |
| 1032 | c = read_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1033 | if (c == '\t') { |
| 1034 | after_tab = 1; |
| 1035 | break; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 1036 | } else if (iscntrl(c)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | if (L_ECHOCTL(tty)) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1038 | num_chars += 2; |
| 1039 | } else if (!is_continuation(c, tty)) { |
| 1040 | num_chars++; |
| 1041 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1043 | echo_erase_tab(num_chars, after_tab, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | } else { |
| 1045 | if (iscntrl(c) && L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1046 | echo_char_raw('\b', ldata); |
| 1047 | echo_char_raw(' ', ldata); |
| 1048 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | } |
| 1050 | if (!iscntrl(c) || L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1051 | echo_char_raw('\b', ldata); |
| 1052 | echo_char_raw(' ', ldata); |
| 1053 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1054 | } |
| 1055 | } |
| 1056 | } |
| 1057 | if (kill_type == ERASE) |
| 1058 | break; |
| 1059 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1060 | if (ldata->read_head == ldata->canon_head && L_ECHO(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1061 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1062 | } |
| 1063 | |
| 1064 | /** |
| 1065 | * isig - handle the ISIG optio |
| 1066 | * @sig: signal |
| 1067 | * @tty: terminal |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1069 | * Called when a signal is being sent due to terminal input. |
| 1070 | * Called from the driver receive_buf path so serialized. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1071 | * |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1072 | * Performs input and output flush if !NOFLSH. In this context, the echo |
| 1073 | * buffer is 'output'. The signal is processed first to alert any current |
| 1074 | * readers or writers to discontinue and exit their i/o loops. |
| 1075 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1076 | * Locking: ctrl_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1078 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1079 | static void __isig(int sig, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1081 | struct pid *tty_pgrp = tty_get_pgrp(tty); |
| 1082 | if (tty_pgrp) { |
| 1083 | kill_pgrp(tty_pgrp, sig, 1); |
| 1084 | put_pid(tty_pgrp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | } |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1086 | } |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1087 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1088 | static void isig(int sig, struct tty_struct *tty) |
| 1089 | { |
| 1090 | struct n_tty_data *ldata = tty->disc_data; |
| 1091 | |
| 1092 | if (L_NOFLSH(tty)) { |
| 1093 | /* signal only */ |
| 1094 | __isig(sig, tty); |
| 1095 | |
| 1096 | } else { /* signal and flush */ |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1097 | up_read(&tty->termios_rwsem); |
| 1098 | down_write(&tty->termios_rwsem); |
| 1099 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1100 | __isig(sig, tty); |
| 1101 | |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1102 | /* clear echo buffer */ |
| 1103 | mutex_lock(&ldata->output_lock); |
| 1104 | ldata->echo_head = ldata->echo_tail = 0; |
| 1105 | ldata->echo_mark = ldata->echo_commit = 0; |
| 1106 | mutex_unlock(&ldata->output_lock); |
| 1107 | |
| 1108 | /* clear output buffer */ |
| 1109 | tty_driver_flush_buffer(tty); |
| 1110 | |
| 1111 | /* clear input buffer */ |
| 1112 | reset_buffer_flags(tty->disc_data); |
| 1113 | |
| 1114 | /* notify pty master of flush */ |
| 1115 | if (tty->link) |
| 1116 | n_tty_packet_mode_flush(tty); |
| 1117 | |
| 1118 | up_write(&tty->termios_rwsem); |
| 1119 | down_read(&tty->termios_rwsem); |
| 1120 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | } |
| 1122 | |
| 1123 | /** |
| 1124 | * n_tty_receive_break - handle break |
| 1125 | * @tty: terminal |
| 1126 | * |
| 1127 | * An RS232 break event has been hit in the incoming bitstream. This |
| 1128 | * can cause a variety of events depending upon the termios settings. |
| 1129 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1130 | * n_tty_receive_buf()/producer path: |
| 1131 | * caller holds non-exclusive termios_rwsem |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1132 | * |
| 1133 | * Note: may get exclusive termios_rwsem if flushing input buffer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1135 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1136 | static void n_tty_receive_break(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1138 | struct n_tty_data *ldata = tty->disc_data; |
| 1139 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | if (I_IGNBRK(tty)) |
| 1141 | return; |
| 1142 | if (I_BRKINT(tty)) { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1143 | isig(SIGINT, tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | return; |
| 1145 | } |
| 1146 | if (I_PARMRK(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1147 | put_tty_queue('\377', ldata); |
| 1148 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1150 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | } |
| 1152 | |
| 1153 | /** |
| 1154 | * n_tty_receive_overrun - handle overrun reporting |
| 1155 | * @tty: terminal |
| 1156 | * |
| 1157 | * Data arrived faster than we could process it. While the tty |
| 1158 | * driver has flagged this the bits that were missed are gone |
| 1159 | * forever. |
| 1160 | * |
| 1161 | * Called from the receive_buf path so single threaded. Does not |
| 1162 | * need locking as num_overrun and overrun_time are function |
| 1163 | * private. |
| 1164 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1165 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1166 | static void n_tty_receive_overrun(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1168 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1170 | ldata->num_overrun++; |
| 1171 | if (time_after(jiffies, ldata->overrun_time + HZ) || |
| 1172 | time_after(ldata->overrun_time, jiffies)) { |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1173 | tty_warn(tty, "%d input overrun(s)\n", ldata->num_overrun); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1174 | ldata->overrun_time = jiffies; |
| 1175 | ldata->num_overrun = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | /** |
| 1180 | * n_tty_receive_parity_error - error notifier |
| 1181 | * @tty: terminal device |
| 1182 | * @c: character |
| 1183 | * |
| 1184 | * Process a parity error and queue the right data to indicate |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1185 | * the error case if necessary. |
| 1186 | * |
| 1187 | * n_tty_receive_buf()/producer path: |
| 1188 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | */ |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1190 | static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1191 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1192 | struct n_tty_data *ldata = tty->disc_data; |
| 1193 | |
Peter Hurley | 66528f9 | 2014-06-16 08:10:42 -0400 | [diff] [blame] | 1194 | if (I_INPCK(tty)) { |
| 1195 | if (I_IGNPAR(tty)) |
| 1196 | return; |
| 1197 | if (I_PARMRK(tty)) { |
| 1198 | put_tty_queue('\377', ldata); |
| 1199 | put_tty_queue('\0', ldata); |
| 1200 | put_tty_queue(c, ldata); |
| 1201 | } else |
| 1202 | put_tty_queue('\0', ldata); |
| 1203 | } else |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1204 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | } |
| 1206 | |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1207 | static void |
| 1208 | n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c) |
| 1209 | { |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1210 | isig(signal, tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1211 | if (I_IXON(tty)) |
| 1212 | start_tty(tty); |
| 1213 | if (L_ECHO(tty)) { |
| 1214 | echo_char(c, tty); |
| 1215 | commit_echoes(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1216 | } else |
| 1217 | process_echoes(tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1218 | return; |
| 1219 | } |
| 1220 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | /** |
| 1222 | * n_tty_receive_char - perform processing |
| 1223 | * @tty: terminal device |
| 1224 | * @c: character |
| 1225 | * |
| 1226 | * Process an individual character of input received from the driver. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1227 | * This is serialized with respect to itself by the rules for the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | * driver above. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1229 | * |
| 1230 | * n_tty_receive_buf()/producer path: |
| 1231 | * caller holds non-exclusive termios_rwsem |
| 1232 | * publishes canon_head if canonical mode is active |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1233 | * |
| 1234 | * Returns 1 if LNEXT was received, else returns 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1235 | */ |
| 1236 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1237 | static int |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1238 | n_tty_receive_char_special(struct tty_struct *tty, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1240 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | if (I_IXON(tty)) { |
| 1243 | if (c == START_CHAR(tty)) { |
| 1244 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1245 | process_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1246 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | } |
| 1248 | if (c == STOP_CHAR(tty)) { |
| 1249 | stop_tty(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1250 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1251 | } |
| 1252 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1253 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1254 | if (L_ISIG(tty)) { |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1255 | if (c == INTR_CHAR(tty)) { |
| 1256 | n_tty_receive_signal_char(tty, SIGINT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1257 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1258 | } else if (c == QUIT_CHAR(tty)) { |
| 1259 | n_tty_receive_signal_char(tty, SIGQUIT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1260 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1261 | } else if (c == SUSP_CHAR(tty)) { |
| 1262 | n_tty_receive_signal_char(tty, SIGTSTP, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1263 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1264 | } |
| 1265 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1266 | |
Peter Hurley | 855df3c | 2013-07-24 08:29:50 -0400 | [diff] [blame] | 1267 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1268 | start_tty(tty); |
| 1269 | process_echoes(tty); |
| 1270 | } |
| 1271 | |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1272 | if (c == '\r') { |
| 1273 | if (I_IGNCR(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1274 | return 0; |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1275 | if (I_ICRNL(tty)) |
| 1276 | c = '\n'; |
| 1277 | } else if (c == '\n' && I_INLCR(tty)) |
| 1278 | c = '\r'; |
| 1279 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1280 | if (ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) || |
| 1282 | (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) { |
| 1283 | eraser(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1284 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1285 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | } |
| 1287 | if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1288 | ldata->lnext = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1290 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1291 | if (L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1292 | echo_char_raw('^', ldata); |
| 1293 | echo_char_raw('\b', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1294 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | } |
| 1296 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1297 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1299 | if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1300 | size_t tail = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1302 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | echo_char(c, tty); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1304 | echo_char_raw('\n', ldata); |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1305 | while (tail != ldata->read_head) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1306 | echo_char(read_buf(ldata, tail), tty); |
| 1307 | tail++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1308 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1309 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1310 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | } |
| 1312 | if (c == '\n') { |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1313 | if (L_ECHO(tty) || L_ECHONL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1314 | echo_char_raw('\n', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1315 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | } |
| 1317 | goto handle_newline; |
| 1318 | } |
| 1319 | if (c == EOF_CHAR(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | c = __DISABLED_CHAR; |
| 1321 | goto handle_newline; |
| 1322 | } |
| 1323 | if ((c == EOL_CHAR(tty)) || |
| 1324 | (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) { |
| 1325 | /* |
| 1326 | * XXX are EOL_CHAR and EOL2_CHAR echoed?!? |
| 1327 | */ |
| 1328 | if (L_ECHO(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1330 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1331 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1332 | echo_char(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1333 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | } |
| 1335 | /* |
| 1336 | * XXX does PARMRK doubling happen for |
| 1337 | * EOL_CHAR and EOL2_CHAR? |
| 1338 | */ |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1339 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1340 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1342 | handle_newline: |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1343 | set_bit(ldata->read_head & (N_TTY_BUF_SIZE - 1), ldata->read_flags); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1344 | put_tty_queue(c, ldata); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1345 | smp_store_release(&ldata->canon_head, ldata->read_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1346 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 1347 | wake_up_interruptible_poll(&tty->read_wait, EPOLLIN); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1348 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | } |
| 1350 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1351 | |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1352 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1353 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | if (c == '\n') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1355 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | else { |
| 1357 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1358 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1359 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1360 | echo_char(c, tty); |
| 1361 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1362 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | } |
| 1364 | |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1365 | /* PARMRK doubling check */ |
| 1366 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1367 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1369 | put_tty_queue(c, ldata); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1370 | return 0; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1371 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1373 | static inline void |
| 1374 | n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c) |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1375 | { |
| 1376 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1377 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1378 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1379 | start_tty(tty); |
| 1380 | process_echoes(tty); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1381 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1382 | if (L_ECHO(tty)) { |
| 1383 | finish_erasing(ldata); |
| 1384 | /* Record the column of first canon char. */ |
| 1385 | if (ldata->canon_head == ldata->read_head) |
| 1386 | echo_set_canon_col(ldata); |
| 1387 | echo_char(c, tty); |
| 1388 | commit_echoes(tty); |
| 1389 | } |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1390 | /* PARMRK doubling check */ |
| 1391 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1392 | put_tty_queue(c, ldata); |
| 1393 | put_tty_queue(c, ldata); |
| 1394 | } |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1395 | |
Peter Hurley | eb3e466 | 2013-12-02 14:24:42 -0500 | [diff] [blame] | 1396 | static void n_tty_receive_char(struct tty_struct *tty, unsigned char c) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1397 | { |
| 1398 | n_tty_receive_char_inline(tty, c); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1399 | } |
| 1400 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1401 | static inline void |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1402 | n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c) |
| 1403 | { |
| 1404 | struct n_tty_data *ldata = tty->disc_data; |
| 1405 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1406 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1407 | start_tty(tty); |
| 1408 | process_echoes(tty); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1409 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1410 | if (L_ECHO(tty)) { |
| 1411 | finish_erasing(ldata); |
| 1412 | /* Record the column of first canon char. */ |
| 1413 | if (ldata->canon_head == ldata->read_head) |
| 1414 | echo_set_canon_col(ldata); |
| 1415 | echo_char(c, tty); |
| 1416 | commit_echoes(tty); |
| 1417 | } |
| 1418 | put_tty_queue(c, ldata); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1419 | } |
| 1420 | |
Peter Hurley | 8dc4b25 | 2013-12-02 14:24:43 -0500 | [diff] [blame] | 1421 | static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c) |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1422 | { |
| 1423 | if (I_ISTRIP(tty)) |
| 1424 | c &= 0x7f; |
| 1425 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1426 | c = tolower(c); |
| 1427 | |
| 1428 | if (I_IXON(tty)) { |
| 1429 | if (c == STOP_CHAR(tty)) |
| 1430 | stop_tty(tty); |
| 1431 | else if (c == START_CHAR(tty) || |
| 1432 | (tty->stopped && !tty->flow_stopped && I_IXANY(tty) && |
| 1433 | c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && |
| 1434 | c != SUSP_CHAR(tty))) { |
| 1435 | start_tty(tty); |
| 1436 | process_echoes(tty); |
| 1437 | } |
| 1438 | } |
| 1439 | } |
| 1440 | |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1441 | static void |
| 1442 | n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag) |
| 1443 | { |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1444 | switch (flag) { |
| 1445 | case TTY_BREAK: |
| 1446 | n_tty_receive_break(tty); |
| 1447 | break; |
| 1448 | case TTY_PARITY: |
| 1449 | case TTY_FRAME: |
| 1450 | n_tty_receive_parity_error(tty, c); |
| 1451 | break; |
| 1452 | case TTY_OVERRUN: |
| 1453 | n_tty_receive_overrun(tty); |
| 1454 | break; |
| 1455 | default: |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1456 | tty_err(tty, "unknown flag %d\n", flag); |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1457 | break; |
| 1458 | } |
| 1459 | } |
| 1460 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1461 | static void |
| 1462 | n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag) |
| 1463 | { |
| 1464 | struct n_tty_data *ldata = tty->disc_data; |
| 1465 | |
| 1466 | ldata->lnext = 0; |
| 1467 | if (likely(flag == TTY_NORMAL)) { |
| 1468 | if (I_ISTRIP(tty)) |
| 1469 | c &= 0x7f; |
| 1470 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1471 | c = tolower(c); |
| 1472 | n_tty_receive_char(tty, c); |
| 1473 | } else |
| 1474 | n_tty_receive_char_flagged(tty, c, flag); |
| 1475 | } |
| 1476 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1477 | static void |
| 1478 | n_tty_receive_buf_real_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1479 | char *fp, int count) |
| 1480 | { |
| 1481 | struct n_tty_data *ldata = tty->disc_data; |
| 1482 | size_t n, head; |
| 1483 | |
| 1484 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1485 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1486 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1487 | ldata->read_head += n; |
| 1488 | cp += n; |
| 1489 | count -= n; |
| 1490 | |
| 1491 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1492 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1493 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1494 | ldata->read_head += n; |
| 1495 | } |
| 1496 | |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1497 | static void |
| 1498 | n_tty_receive_buf_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1499 | char *fp, int count) |
| 1500 | { |
| 1501 | struct n_tty_data *ldata = tty->disc_data; |
| 1502 | char flag = TTY_NORMAL; |
| 1503 | |
| 1504 | while (count--) { |
| 1505 | if (fp) |
| 1506 | flag = *fp++; |
| 1507 | if (likely(flag == TTY_NORMAL)) |
| 1508 | put_tty_queue(*cp++, ldata); |
| 1509 | else |
| 1510 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1511 | } |
| 1512 | } |
| 1513 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1514 | static void |
| 1515 | n_tty_receive_buf_closing(struct tty_struct *tty, const unsigned char *cp, |
| 1516 | char *fp, int count) |
| 1517 | { |
| 1518 | char flag = TTY_NORMAL; |
| 1519 | |
| 1520 | while (count--) { |
| 1521 | if (fp) |
| 1522 | flag = *fp++; |
| 1523 | if (likely(flag == TTY_NORMAL)) |
| 1524 | n_tty_receive_char_closing(tty, *cp++); |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1525 | } |
| 1526 | } |
| 1527 | |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1528 | static void |
| 1529 | n_tty_receive_buf_standard(struct tty_struct *tty, const unsigned char *cp, |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1530 | char *fp, int count) |
| 1531 | { |
| 1532 | struct n_tty_data *ldata = tty->disc_data; |
| 1533 | char flag = TTY_NORMAL; |
| 1534 | |
| 1535 | while (count--) { |
| 1536 | if (fp) |
| 1537 | flag = *fp++; |
| 1538 | if (likely(flag == TTY_NORMAL)) { |
| 1539 | unsigned char c = *cp++; |
| 1540 | |
| 1541 | if (I_ISTRIP(tty)) |
| 1542 | c &= 0x7f; |
| 1543 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1544 | c = tolower(c); |
| 1545 | if (L_EXTPROC(tty)) { |
| 1546 | put_tty_queue(c, ldata); |
| 1547 | continue; |
| 1548 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1549 | if (!test_bit(c, ldata->char_map)) |
| 1550 | n_tty_receive_char_inline(tty, c); |
| 1551 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1552 | if (fp) |
| 1553 | flag = *fp++; |
| 1554 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1555 | count--; |
| 1556 | } |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1557 | } else |
| 1558 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1559 | } |
| 1560 | } |
| 1561 | |
| 1562 | static void |
| 1563 | n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp, |
| 1564 | char *fp, int count) |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1565 | { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1566 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1567 | char flag = TTY_NORMAL; |
| 1568 | |
| 1569 | while (count--) { |
| 1570 | if (fp) |
| 1571 | flag = *fp++; |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1572 | if (likely(flag == TTY_NORMAL)) { |
| 1573 | unsigned char c = *cp++; |
| 1574 | |
| 1575 | if (!test_bit(c, ldata->char_map)) |
| 1576 | n_tty_receive_char_fast(tty, c); |
| 1577 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1578 | if (fp) |
| 1579 | flag = *fp++; |
| 1580 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1581 | count--; |
| 1582 | } |
| 1583 | } else |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1584 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1585 | } |
| 1586 | } |
| 1587 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1588 | static void __receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1589 | char *fp, int count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1590 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1591 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1592 | bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1593 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1594 | if (ldata->real_raw) |
| 1595 | n_tty_receive_buf_real_raw(tty, cp, fp, count); |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1596 | else if (ldata->raw || (L_EXTPROC(tty) && !preops)) |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1597 | n_tty_receive_buf_raw(tty, cp, fp, count); |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1598 | else if (tty->closing && !L_EXTPROC(tty)) |
| 1599 | n_tty_receive_buf_closing(tty, cp, fp, count); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1600 | else { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1601 | if (ldata->lnext) { |
| 1602 | char flag = TTY_NORMAL; |
| 1603 | |
| 1604 | if (fp) |
| 1605 | flag = *fp++; |
| 1606 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1607 | count--; |
| 1608 | } |
| 1609 | |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1610 | if (!preops && !I_PARMRK(tty)) |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1611 | n_tty_receive_buf_fast(tty, cp, fp, count); |
| 1612 | else |
| 1613 | n_tty_receive_buf_standard(tty, cp, fp, count); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 1614 | |
| 1615 | flush_echoes(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1616 | if (tty->ops->flush_chars) |
| 1617 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | } |
| 1619 | |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1620 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1621 | return; |
| 1622 | |
| 1623 | /* publish read_head to consumer */ |
| 1624 | smp_store_release(&ldata->commit_head, ldata->read_head); |
| 1625 | |
Peter Hurley | 33d7136 | 2016-01-09 21:45:08 -0800 | [diff] [blame] | 1626 | if (read_cnt(ldata)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 1628 | wake_up_interruptible_poll(&tty->read_wait, EPOLLIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | } |
| 1631 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1632 | /** |
| 1633 | * n_tty_receive_buf_common - process input |
| 1634 | * @tty: device to receive input |
| 1635 | * @cp: input chars |
| 1636 | * @fp: flags for each char (if NULL, all chars are TTY_NORMAL) |
| 1637 | * @count: number of input chars in @cp |
| 1638 | * |
| 1639 | * Called by the terminal driver when a block of characters has |
| 1640 | * been received. This function must be called from soft contexts |
| 1641 | * not from interrupt context. The driver is responsible for making |
| 1642 | * calls one at a time and in order (or using flush_to_ldisc) |
| 1643 | * |
| 1644 | * Returns the # of input chars from @cp which were processed. |
| 1645 | * |
| 1646 | * In canonical mode, the maximum line length is 4096 chars (including |
| 1647 | * the line termination char); lines longer than 4096 chars are |
| 1648 | * truncated. After 4095 chars, input data is still processed but |
| 1649 | * not stored. Overflow processing ensures the tty can always |
| 1650 | * receive more input until at least one line can be read. |
| 1651 | * |
| 1652 | * In non-canonical mode, the read buffer will only accept 4095 chars; |
| 1653 | * this provides the necessary space for a newline char if the input |
| 1654 | * mode is switched to canonical. |
| 1655 | * |
| 1656 | * Note it is possible for the read buffer to _contain_ 4096 chars |
| 1657 | * in non-canonical mode: the read buffer could already contain the |
| 1658 | * maximum canon line of 4096 chars when the mode is switched to |
| 1659 | * non-canonical. |
| 1660 | * |
| 1661 | * n_tty_receive_buf()/producer path: |
| 1662 | * claims non-exclusive termios_rwsem |
| 1663 | * publishes commit_head or canon_head |
| 1664 | */ |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1665 | static int |
| 1666 | n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp, |
| 1667 | char *fp, int count, int flow) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1668 | { |
| 1669 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1670 | int room, n, rcvd = 0, overflow; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1671 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1672 | down_read(&tty->termios_rwsem); |
| 1673 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1674 | while (1) { |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1675 | /* |
Peter Hurley | 06c49f9 | 2015-01-16 15:05:38 -0500 | [diff] [blame] | 1676 | * When PARMRK is set, each input char may take up to 3 chars |
| 1677 | * in the read buf; reduce the buffer space avail by 3x |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1678 | * |
| 1679 | * If we are doing input canonicalization, and there are no |
| 1680 | * pending newlines, let characters through without limit, so |
| 1681 | * that erase characters will be handled. Other excess |
| 1682 | * characters will be beeped. |
| 1683 | * |
| 1684 | * paired with store in *_copy_from_read_buf() -- guarantees |
| 1685 | * the consumer has loaded the data in read_buf up to the new |
| 1686 | * read_tail (so this producer will not overwrite unread data) |
| 1687 | */ |
| 1688 | size_t tail = smp_load_acquire(&ldata->read_tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1689 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1690 | room = N_TTY_BUF_SIZE - (ldata->read_head - tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1691 | if (I_PARMRK(tty)) |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1692 | room = (room + 2) / 3; |
| 1693 | room--; |
| 1694 | if (room <= 0) { |
| 1695 | overflow = ldata->icanon && ldata->canon_head == tail; |
| 1696 | if (overflow && room < 0) |
| 1697 | ldata->read_head--; |
| 1698 | room = overflow; |
| 1699 | ldata->no_room = flow && !room; |
| 1700 | } else |
| 1701 | overflow = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1702 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1703 | n = min(count, room); |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1704 | if (!n) |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1705 | break; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1706 | |
| 1707 | /* ignore parity errors if handling overflow */ |
| 1708 | if (!overflow || !fp || *fp != TTY_PARITY) |
| 1709 | __receive_buf(tty, cp, fp, n); |
| 1710 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1711 | cp += n; |
| 1712 | if (fp) |
| 1713 | fp += n; |
| 1714 | count -= n; |
| 1715 | rcvd += n; |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1716 | } |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1717 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1718 | tty->receive_room = room; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1719 | |
| 1720 | /* Unthrottle if handling overflow on pty */ |
| 1721 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
| 1722 | if (overflow) { |
| 1723 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 1724 | tty_unthrottle_safe(tty); |
| 1725 | __tty_set_flow_change(tty, 0); |
| 1726 | } |
| 1727 | } else |
| 1728 | n_tty_check_throttle(tty); |
| 1729 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1730 | up_read(&tty->termios_rwsem); |
| 1731 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1732 | return rcvd; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1733 | } |
| 1734 | |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1735 | static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1736 | char *fp, int count) |
| 1737 | { |
| 1738 | n_tty_receive_buf_common(tty, cp, fp, count, 0); |
| 1739 | } |
| 1740 | |
| 1741 | static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp, |
| 1742 | char *fp, int count) |
| 1743 | { |
| 1744 | return n_tty_receive_buf_common(tty, cp, fp, count, 1); |
| 1745 | } |
| 1746 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | /** |
| 1748 | * n_tty_set_termios - termios data changed |
| 1749 | * @tty: terminal |
| 1750 | * @old: previous data |
| 1751 | * |
| 1752 | * Called by the tty layer when the user changes termios flags so |
| 1753 | * that the line discipline can plan ahead. This function cannot sleep |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1754 | * and is protected from re-entry by the tty layer. The user is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1755 | * guaranteed that this function will not be re-entered or in progress |
| 1756 | * when the ldisc is closed. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1757 | * |
Peter Hurley | 6a1c068 | 2013-06-15 09:14:23 -0400 | [diff] [blame] | 1758 | * Locking: Caller holds tty->termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1759 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1760 | |
| 1761 | static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1762 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1763 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1764 | |
Linus Torvalds | 966031f | 2017-12-20 17:57:06 -0800 | [diff] [blame] | 1765 | if (!old || (old->c_lflag ^ tty->termios.c_lflag) & (ICANON | EXTPROC)) { |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 1766 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 1767 | ldata->line_start = ldata->read_tail; |
| 1768 | if (!L_ICANON(tty) || !read_cnt(ldata)) { |
| 1769 | ldata->canon_head = ldata->read_tail; |
| 1770 | ldata->push = 0; |
| 1771 | } else { |
| 1772 | set_bit((ldata->read_head - 1) & (N_TTY_BUF_SIZE - 1), |
| 1773 | ldata->read_flags); |
| 1774 | ldata->canon_head = ldata->read_head; |
| 1775 | ldata->push = 1; |
| 1776 | } |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1777 | ldata->commit_head = ldata->read_head; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1778 | ldata->erasing = 0; |
Peter Hurley | 6f9b028 | 2013-06-15 09:14:27 -0400 | [diff] [blame] | 1779 | ldata->lnext = 0; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1780 | } |
| 1781 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1782 | ldata->icanon = (L_ICANON(tty) != 0); |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 1783 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1784 | if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || |
| 1785 | I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || |
| 1786 | I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || |
| 1787 | I_PARMRK(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1788 | bitmap_zero(ldata->char_map, 256); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1789 | |
| 1790 | if (I_IGNCR(tty) || I_ICRNL(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1791 | set_bit('\r', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1792 | if (I_INLCR(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1793 | set_bit('\n', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1794 | |
| 1795 | if (L_ICANON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1796 | set_bit(ERASE_CHAR(tty), ldata->char_map); |
| 1797 | set_bit(KILL_CHAR(tty), ldata->char_map); |
| 1798 | set_bit(EOF_CHAR(tty), ldata->char_map); |
| 1799 | set_bit('\n', ldata->char_map); |
| 1800 | set_bit(EOL_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1801 | if (L_IEXTEN(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1802 | set_bit(WERASE_CHAR(tty), ldata->char_map); |
| 1803 | set_bit(LNEXT_CHAR(tty), ldata->char_map); |
| 1804 | set_bit(EOL2_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | if (L_ECHO(tty)) |
| 1806 | set_bit(REPRINT_CHAR(tty), |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1807 | ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | } |
| 1809 | } |
| 1810 | if (I_IXON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1811 | set_bit(START_CHAR(tty), ldata->char_map); |
| 1812 | set_bit(STOP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1813 | } |
| 1814 | if (L_ISIG(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1815 | set_bit(INTR_CHAR(tty), ldata->char_map); |
| 1816 | set_bit(QUIT_CHAR(tty), ldata->char_map); |
| 1817 | set_bit(SUSP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1818 | } |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1819 | clear_bit(__DISABLED_CHAR, ldata->char_map); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1820 | ldata->raw = 0; |
| 1821 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | } else { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1823 | ldata->raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1824 | if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && |
| 1825 | (I_IGNPAR(tty) || !I_INPCK(tty)) && |
| 1826 | (tty->driver->flags & TTY_DRIVER_REAL_RAW)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1827 | ldata->real_raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1828 | else |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1829 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1830 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1831 | /* |
| 1832 | * Fix tty hang when I_IXON(tty) is cleared, but the tty |
| 1833 | * been stopped by STOP_CHAR(tty) before it. |
| 1834 | */ |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1835 | if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) { |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1836 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1837 | process_echoes(tty); |
| 1838 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1839 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1840 | /* The termios change make the tty ready for I/O */ |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1841 | wake_up_interruptible(&tty->write_wait); |
| 1842 | wake_up_interruptible(&tty->read_wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1843 | } |
| 1844 | |
| 1845 | /** |
| 1846 | * n_tty_close - close the ldisc for this tty |
| 1847 | * @tty: device |
| 1848 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1849 | * Called from the terminal layer when this line discipline is |
| 1850 | * being shut down, either because of a close or becsuse of a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1851 | * discipline change. The function will not be called while other |
| 1852 | * ldisc methods are in progress. |
| 1853 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1854 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1855 | static void n_tty_close(struct tty_struct *tty) |
| 1856 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1857 | struct n_tty_data *ldata = tty->disc_data; |
| 1858 | |
Peter Hurley | 7990131 | 2013-03-11 16:44:23 -0400 | [diff] [blame] | 1859 | if (tty->link) |
| 1860 | n_tty_packet_mode_flush(tty); |
| 1861 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1862 | vfree(ldata); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1863 | tty->disc_data = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | } |
| 1865 | |
| 1866 | /** |
| 1867 | * n_tty_open - open an ldisc |
| 1868 | * @tty: terminal to open |
| 1869 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1870 | * Called when this line discipline is being attached to the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1871 | * terminal device. Can sleep. Called serialized so that no |
| 1872 | * other events will occur in parallel. No further open will occur |
| 1873 | * until a close. |
| 1874 | */ |
| 1875 | |
| 1876 | static int n_tty_open(struct tty_struct *tty) |
| 1877 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1878 | struct n_tty_data *ldata; |
| 1879 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1880 | /* Currently a malloc failure here can panic */ |
| 1881 | ldata = vmalloc(sizeof(*ldata)); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1882 | if (!ldata) |
| 1883 | goto err; |
| 1884 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1885 | ldata->overrun_time = jiffies; |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1886 | mutex_init(&ldata->atomic_read_lock); |
| 1887 | mutex_init(&ldata->output_lock); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1888 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1889 | tty->disc_data = ldata; |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 1890 | reset_buffer_flags(tty->disc_data); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1891 | ldata->column = 0; |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1892 | ldata->canon_column = 0; |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1893 | ldata->num_overrun = 0; |
| 1894 | ldata->no_room = 0; |
| 1895 | ldata->lnext = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1896 | tty->closing = 0; |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 1897 | /* indicate buffer work may resume */ |
| 1898 | clear_bit(TTY_LDISC_HALTED, &tty->flags); |
| 1899 | n_tty_set_termios(tty, NULL); |
| 1900 | tty_unthrottle(tty); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1901 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | return 0; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1903 | err: |
Jiri Slaby | b91939f | 2012-10-18 22:26:35 +0200 | [diff] [blame] | 1904 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1905 | } |
| 1906 | |
Peter Hurley | eafbe67 | 2013-12-02 14:24:45 -0500 | [diff] [blame] | 1907 | static inline int input_available_p(struct tty_struct *tty, int poll) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1908 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1909 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a593480 | 2014-02-11 11:49:58 -0500 | [diff] [blame] | 1910 | int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1911 | |
Peter Hurley | 25e8d0e | 2014-02-11 18:55:30 -0500 | [diff] [blame] | 1912 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1913 | return ldata->canon_head != ldata->read_tail; |
| 1914 | else |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1915 | return ldata->commit_head - ldata->read_tail >= amt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1916 | } |
| 1917 | |
| 1918 | /** |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 1919 | * copy_from_read_buf - copy read data directly |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | * @tty: terminal device |
| 1921 | * @b: user data |
| 1922 | * @nr: size of data |
| 1923 | * |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1924 | * Helper function to speed up n_tty_read. It is only called when |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1925 | * ICANON is off; it copies characters straight from the tty queue to |
| 1926 | * user space directly. It can be profitably called twice; once to |
| 1927 | * drain the space from the tail pointer to the (physical) end of the |
| 1928 | * buffer, and once to drain the space from the (physical) beginning of |
| 1929 | * the buffer to head pointer. |
| 1930 | * |
Jiri Slaby | bddc7152f | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1931 | * Called under the ldata->atomic_read_lock sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1932 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1933 | * n_tty_read()/consumer path: |
| 1934 | * caller holds non-exclusive termios_rwsem |
| 1935 | * read_tail published |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1936 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1937 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1938 | static int copy_from_read_buf(struct tty_struct *tty, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1939 | unsigned char __user **b, |
| 1940 | size_t *nr) |
| 1941 | |
| 1942 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1943 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1944 | int retval; |
| 1945 | size_t n; |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 1946 | bool is_eof; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1947 | size_t head = smp_load_acquire(&ldata->commit_head); |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1948 | size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1949 | |
| 1950 | retval = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1951 | n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1952 | n = min(*nr, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1953 | if (n) { |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1954 | const unsigned char *from = read_buf_addr(ldata, tail); |
| 1955 | retval = copy_to_user(*b, from, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1956 | n -= retval; |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1957 | is_eof = n == 1 && *from == EOF_CHAR(tty); |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 1958 | tty_audit_add_data(tty, from, n); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1959 | smp_store_release(&ldata->read_tail, ldata->read_tail + n); |
hyc@symas.com | 26df6d1 | 2010-06-22 10:14:49 -0700 | [diff] [blame] | 1960 | /* Turn single EOF into zero-length read */ |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1961 | if (L_EXTPROC(tty) && ldata->icanon && is_eof && |
| 1962 | (head == ldata->read_tail)) |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 1963 | n = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1964 | *b += n; |
| 1965 | *nr -= n; |
| 1966 | } |
| 1967 | return retval; |
| 1968 | } |
| 1969 | |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1970 | /** |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 1971 | * canon_copy_from_read_buf - copy read data in canonical mode |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1972 | * @tty: terminal device |
| 1973 | * @b: user data |
| 1974 | * @nr: size of data |
| 1975 | * |
| 1976 | * Helper function for n_tty_read. It is only called when ICANON is on; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 1977 | * it copies one line of input up to and including the line-delimiting |
| 1978 | * character into the user-space buffer. |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1979 | * |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 1980 | * NB: When termios is changed from non-canonical to canonical mode and |
| 1981 | * the read buffer contains data, n_tty_set_termios() simulates an EOF |
| 1982 | * push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer. |
| 1983 | * This causes data already processed as input to be immediately available |
| 1984 | * as input although a newline has not been received. |
| 1985 | * |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1986 | * Called under the atomic_read_lock mutex |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1987 | * |
| 1988 | * n_tty_read()/consumer path: |
| 1989 | * caller holds non-exclusive termios_rwsem |
| 1990 | * read_tail published |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1991 | */ |
| 1992 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 1993 | static int canon_copy_from_read_buf(struct tty_struct *tty, |
| 1994 | unsigned char __user **b, |
| 1995 | size_t *nr) |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1996 | { |
| 1997 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 1998 | size_t n, size, more, c; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1999 | size_t eol; |
| 2000 | size_t tail; |
| 2001 | int ret, found = 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2002 | |
| 2003 | /* N.B. avoid overrun if nr == 0 */ |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2004 | if (!*nr) |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2005 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2006 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2007 | n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail); |
| 2008 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2009 | tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2010 | size = min_t(size_t, tail + n, N_TTY_BUF_SIZE); |
| 2011 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2012 | n_tty_trace("%s: nr:%zu tail:%zu n:%zu size:%zu\n", |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2013 | __func__, *nr, tail, n, size); |
| 2014 | |
| 2015 | eol = find_next_bit(ldata->read_flags, size, tail); |
| 2016 | more = n - (size - tail); |
| 2017 | if (eol == N_TTY_BUF_SIZE && more) { |
| 2018 | /* scan wrapped without finding set bit */ |
| 2019 | eol = find_next_bit(ldata->read_flags, more, 0); |
Peter Hurley | b985e9e | 2015-11-27 14:11:04 -0500 | [diff] [blame] | 2020 | found = eol != more; |
| 2021 | } else |
| 2022 | found = eol != size; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2023 | |
Peter Hurley | c77569d | 2013-11-22 07:16:25 -0500 | [diff] [blame] | 2024 | n = eol - tail; |
Mark Tomlinson | da555db | 2015-05-18 12:01:48 +1200 | [diff] [blame] | 2025 | if (n > N_TTY_BUF_SIZE) |
| 2026 | n += N_TTY_BUF_SIZE; |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2027 | c = n + found; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2028 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2029 | if (!found || read_buf(ldata, eol) != __DISABLED_CHAR) { |
| 2030 | c = min(*nr, c); |
| 2031 | n = c; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2032 | } |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2033 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2034 | n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n", |
| 2035 | __func__, eol, found, n, c, tail, more); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2036 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2037 | ret = tty_copy_to_user(tty, *b, tail, n); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2038 | if (ret) |
| 2039 | return -EFAULT; |
| 2040 | *b += n; |
| 2041 | *nr -= n; |
| 2042 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2043 | if (found) |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2044 | clear_bit(eol, ldata->read_flags); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 2045 | smp_store_release(&ldata->read_tail, ldata->read_tail + c); |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2046 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2047 | if (found) { |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 2048 | if (!ldata->push) |
| 2049 | ldata->line_start = ldata->read_tail; |
| 2050 | else |
| 2051 | ldata->push = 0; |
Peter Hurley | b50819f | 2016-01-09 22:55:30 -0800 | [diff] [blame] | 2052 | tty_audit_push(); |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2053 | } |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2054 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2055 | } |
| 2056 | |
Al Viro | cc4191d | 2008-03-29 03:08:48 +0000 | [diff] [blame] | 2057 | extern ssize_t redirected_tty_write(struct file *, const char __user *, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2058 | size_t, loff_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2059 | |
| 2060 | /** |
| 2061 | * job_control - check job control |
| 2062 | * @tty: tty |
| 2063 | * @file: file handle |
| 2064 | * |
| 2065 | * Perform job control management checks on this file/tty descriptor |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2066 | * and if appropriate send any needed signals and return a negative |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2067 | * error code if action should be taken. |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2068 | * |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2069 | * Locking: redirected write test is safe |
| 2070 | * current->signal->tty check is safe |
| 2071 | * ctrl_lock to safely reference tty->pgrp |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2072 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2073 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2074 | static int job_control(struct tty_struct *tty, struct file *file) |
| 2075 | { |
| 2076 | /* Job control check -- must be done at start and after |
| 2077 | every sleep (POSIX.1 7.1.1.4). */ |
| 2078 | /* NOTE: not yet done after every sleep pending a thorough |
| 2079 | check of the logic of this change. -- jlc */ |
| 2080 | /* don't stop on /dev/console */ |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2081 | if (file->f_op->write == redirected_tty_write) |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2082 | return 0; |
| 2083 | |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2084 | return __tty_check_change(tty, SIGTTIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2085 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2086 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2087 | |
| 2088 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2089 | * n_tty_read - read function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2090 | * @tty: tty device |
| 2091 | * @file: file object |
| 2092 | * @buf: userspace buffer pointer |
| 2093 | * @nr: size of I/O |
| 2094 | * |
| 2095 | * Perform reads for the line discipline. We are guaranteed that the |
| 2096 | * line discipline will not be closed under us but we may get multiple |
| 2097 | * parallel readers and must handle this ourselves. We may also get |
| 2098 | * a hangup. Always called in user context, may sleep. |
| 2099 | * |
| 2100 | * This code must be sure never to sleep through a hangup. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2101 | * |
| 2102 | * n_tty_read()/consumer path: |
| 2103 | * claims non-exclusive termios_rwsem |
| 2104 | * publishes read_tail |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2105 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2106 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2107 | static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2108 | unsigned char __user *buf, size_t nr) |
| 2109 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2110 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2111 | unsigned char __user *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2112 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2113 | int c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2114 | int minimum, time; |
| 2115 | ssize_t retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2116 | long timeout; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2117 | int packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2118 | size_t tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2119 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2120 | c = job_control(tty, file); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2121 | if (c < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2122 | return c; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2123 | |
Peter Hurley | aefceaf | 2013-08-11 08:04:23 -0400 | [diff] [blame] | 2124 | /* |
| 2125 | * Internal serialization of reads. |
| 2126 | */ |
| 2127 | if (file->f_flags & O_NONBLOCK) { |
| 2128 | if (!mutex_trylock(&ldata->atomic_read_lock)) |
| 2129 | return -EAGAIN; |
| 2130 | } else { |
| 2131 | if (mutex_lock_interruptible(&ldata->atomic_read_lock)) |
| 2132 | return -ERESTARTSYS; |
| 2133 | } |
| 2134 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2135 | down_read(&tty->termios_rwsem); |
| 2136 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2137 | minimum = time = 0; |
| 2138 | timeout = MAX_SCHEDULE_TIMEOUT; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2139 | if (!ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2140 | minimum = MIN_CHAR(tty); |
| 2141 | if (minimum) { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2142 | time = (HZ / 10) * TIME_CHAR(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | } else { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2144 | timeout = (HZ / 10) * TIME_CHAR(tty); |
Peter Hurley | 33d7136 | 2016-01-09 21:45:08 -0800 | [diff] [blame] | 2145 | minimum = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2146 | } |
| 2147 | } |
| 2148 | |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2149 | packet = tty->packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2150 | tail = ldata->read_tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2151 | |
| 2152 | add_wait_queue(&tty->read_wait, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2153 | while (nr) { |
| 2154 | /* First test for status change. */ |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2155 | if (packet && tty->link->ctrl_status) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2156 | unsigned char cs; |
| 2157 | if (b != buf) |
| 2158 | break; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2159 | spin_lock_irq(&tty->link->ctrl_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2160 | cs = tty->link->ctrl_status; |
| 2161 | tty->link->ctrl_status = 0; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2162 | spin_unlock_irq(&tty->link->ctrl_lock); |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2163 | if (put_user(cs, b)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2164 | retval = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2165 | break; |
| 2166 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2167 | b++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2168 | nr--; |
| 2169 | break; |
| 2170 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2171 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2172 | if (!input_available_p(tty, 0)) { |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2173 | up_read(&tty->termios_rwsem); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2174 | tty_buffer_flush_work(tty->port); |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2175 | down_read(&tty->termios_rwsem); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2176 | if (!input_available_p(tty, 0)) { |
| 2177 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { |
| 2178 | retval = -EIO; |
| 2179 | break; |
| 2180 | } |
| 2181 | if (tty_hung_up_p(file)) |
| 2182 | break; |
| 2183 | if (!timeout) |
| 2184 | break; |
| 2185 | if (file->f_flags & O_NONBLOCK) { |
| 2186 | retval = -EAGAIN; |
| 2187 | break; |
| 2188 | } |
| 2189 | if (signal_pending(current)) { |
| 2190 | retval = -ERESTARTSYS; |
| 2191 | break; |
| 2192 | } |
| 2193 | up_read(&tty->termios_rwsem); |
| 2194 | |
| 2195 | timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, |
| 2196 | timeout); |
| 2197 | |
| 2198 | down_read(&tty->termios_rwsem); |
| 2199 | continue; |
| 2200 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2201 | } |
| 2202 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2203 | if (ldata->icanon && !L_EXTPROC(tty)) { |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2204 | retval = canon_copy_from_read_buf(tty, &b, &nr); |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2205 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2206 | break; |
| 2207 | } else { |
| 2208 | int uncopied; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2209 | |
| 2210 | /* Deal with packet mode. */ |
| 2211 | if (packet && b == buf) { |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2212 | if (put_user(TIOCPKT_DATA, b)) { |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2213 | retval = -EFAULT; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2214 | break; |
| 2215 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2216 | b++; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2217 | nr--; |
| 2218 | } |
| 2219 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2220 | uncopied = copy_from_read_buf(tty, &b, &nr); |
| 2221 | uncopied += copy_from_read_buf(tty, &b, &nr); |
| 2222 | if (uncopied) { |
| 2223 | retval = -EFAULT; |
| 2224 | break; |
| 2225 | } |
| 2226 | } |
| 2227 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 2228 | n_tty_check_unthrottle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2229 | |
| 2230 | if (b - buf >= minimum) |
| 2231 | break; |
| 2232 | if (time) |
| 2233 | timeout = time; |
| 2234 | } |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2235 | if (tail != ldata->read_tail) |
| 2236 | n_tty_kick_worker(tty); |
Peter Hurley | 42458f4 | 2013-11-07 13:59:46 -0500 | [diff] [blame] | 2237 | up_read(&tty->termios_rwsem); |
| 2238 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2239 | remove_wait_queue(&tty->read_wait, &wait); |
Peter Hurley | aebf0453 | 2013-11-07 14:01:57 -0500 | [diff] [blame] | 2240 | mutex_unlock(&ldata->atomic_read_lock); |
| 2241 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2242 | if (b - buf) |
| 2243 | retval = b - buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2244 | |
| 2245 | return retval; |
| 2246 | } |
| 2247 | |
| 2248 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2249 | * n_tty_write - write function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2250 | * @tty: tty device |
| 2251 | * @file: file object |
| 2252 | * @buf: userspace buffer pointer |
| 2253 | * @nr: size of I/O |
| 2254 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2255 | * Write function of the terminal device. This is serialized with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2256 | * respect to other write callers but not to termios changes, reads |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2257 | * and other such events. Since the receive code will echo characters, |
| 2258 | * thus calling driver write methods, the output_lock is used in |
| 2259 | * the output processing functions called here as well as in the |
| 2260 | * echo processing function to protect the column state and space |
| 2261 | * left in the buffer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2262 | * |
| 2263 | * This code must be sure never to sleep through a hangup. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2264 | * |
| 2265 | * Locking: output_lock to protect column state and space left |
| 2266 | * (note that the process_output*() functions take this |
| 2267 | * lock themselves) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2268 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2269 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2270 | static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2271 | const unsigned char *buf, size_t nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2272 | { |
| 2273 | const unsigned char *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2274 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2275 | int c; |
| 2276 | ssize_t retval = 0; |
| 2277 | |
| 2278 | /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */ |
| 2279 | if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) { |
| 2280 | retval = tty_check_change(tty); |
| 2281 | if (retval) |
| 2282 | return retval; |
| 2283 | } |
| 2284 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2285 | down_read(&tty->termios_rwsem); |
| 2286 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2287 | /* Write out any echoed characters that are still pending */ |
| 2288 | process_echoes(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 2289 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2290 | add_wait_queue(&tty->write_wait, &wait); |
| 2291 | while (1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2292 | if (signal_pending(current)) { |
| 2293 | retval = -ERESTARTSYS; |
| 2294 | break; |
| 2295 | } |
| 2296 | if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) { |
| 2297 | retval = -EIO; |
| 2298 | break; |
| 2299 | } |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 2300 | if (O_OPOST(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2301 | while (nr > 0) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2302 | ssize_t num = process_output_block(tty, b, nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2303 | if (num < 0) { |
| 2304 | if (num == -EAGAIN) |
| 2305 | break; |
| 2306 | retval = num; |
| 2307 | goto break_out; |
| 2308 | } |
| 2309 | b += num; |
| 2310 | nr -= num; |
| 2311 | if (nr == 0) |
| 2312 | break; |
| 2313 | c = *b; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2314 | if (process_output(c, tty) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2315 | break; |
| 2316 | b++; nr--; |
| 2317 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2318 | if (tty->ops->flush_chars) |
| 2319 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | } else { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2321 | struct n_tty_data *ldata = tty->disc_data; |
| 2322 | |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2323 | while (nr > 0) { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2324 | mutex_lock(&ldata->output_lock); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2325 | c = tty->ops->write(tty, b, nr); |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2326 | mutex_unlock(&ldata->output_lock); |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2327 | if (c < 0) { |
| 2328 | retval = c; |
| 2329 | goto break_out; |
| 2330 | } |
| 2331 | if (!c) |
| 2332 | break; |
| 2333 | b += c; |
| 2334 | nr -= c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2336 | } |
| 2337 | if (!nr) |
| 2338 | break; |
| 2339 | if (file->f_flags & O_NONBLOCK) { |
| 2340 | retval = -EAGAIN; |
| 2341 | break; |
| 2342 | } |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2343 | up_read(&tty->termios_rwsem); |
| 2344 | |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2345 | wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2346 | |
| 2347 | down_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2348 | } |
| 2349 | break_out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2350 | remove_wait_queue(&tty->write_wait, &wait); |
Peter Hurley | 87108bc | 2016-01-09 21:45:14 -0800 | [diff] [blame] | 2351 | if (nr && tty->fasync) |
Thomas Pfaff | ff8cb0f | 2009-01-02 13:47:13 +0000 | [diff] [blame] | 2352 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2353 | up_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2354 | return (b - buf) ? b - buf : retval; |
| 2355 | } |
| 2356 | |
| 2357 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2358 | * n_tty_poll - poll method for N_TTY |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2359 | * @tty: terminal device |
| 2360 | * @file: file accessing it |
| 2361 | * @wait: poll table |
| 2362 | * |
| 2363 | * Called when the line discipline is asked to poll() for data or |
| 2364 | * for special events. This code is not serialized with respect to |
| 2365 | * other events save open/close. |
| 2366 | * |
| 2367 | * This code must be sure never to sleep through a hangup. |
| 2368 | * Called without the kernel lock held - fine |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2369 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2370 | |
Al Viro | afc9a42 | 2017-07-03 06:39:46 -0400 | [diff] [blame] | 2371 | static __poll_t n_tty_poll(struct tty_struct *tty, struct file *file, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2372 | poll_table *wait) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2373 | { |
Al Viro | afc9a42 | 2017-07-03 06:39:46 -0400 | [diff] [blame] | 2374 | __poll_t mask = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2375 | |
| 2376 | poll_wait(file, &tty->read_wait, wait); |
| 2377 | poll_wait(file, &tty->write_wait, wait); |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2378 | if (input_available_p(tty, 1)) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2379 | mask |= EPOLLIN | EPOLLRDNORM; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2380 | else { |
| 2381 | tty_buffer_flush_work(tty->port); |
| 2382 | if (input_available_p(tty, 1)) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2383 | mask |= EPOLLIN | EPOLLRDNORM; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2384 | } |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2385 | if (tty->packet && tty->link->ctrl_status) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2386 | mask |= EPOLLPRI | EPOLLIN | EPOLLRDNORM; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2387 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2388 | mask |= EPOLLHUP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2389 | if (tty_hung_up_p(file)) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2390 | mask |= EPOLLHUP; |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2391 | if (tty->ops->write && !tty_is_writelocked(tty) && |
| 2392 | tty_chars_in_buffer(tty) < WAKEUP_CHARS && |
| 2393 | tty_write_room(tty) > 0) |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame^] | 2394 | mask |= EPOLLOUT | EPOLLWRNORM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2395 | return mask; |
| 2396 | } |
| 2397 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2398 | static unsigned long inq_canon(struct n_tty_data *ldata) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2399 | { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2400 | size_t nr, head, tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2401 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2402 | if (ldata->canon_head == ldata->read_tail) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2403 | return 0; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2404 | head = ldata->canon_head; |
| 2405 | tail = ldata->read_tail; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2406 | nr = head - tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2407 | /* Skip EOF-chars.. */ |
| 2408 | while (head != tail) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2409 | if (test_bit(tail & (N_TTY_BUF_SIZE - 1), ldata->read_flags) && |
| 2410 | read_buf(ldata, tail) == __DISABLED_CHAR) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2411 | nr--; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2412 | tail++; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2413 | } |
| 2414 | return nr; |
| 2415 | } |
| 2416 | |
| 2417 | static int n_tty_ioctl(struct tty_struct *tty, struct file *file, |
| 2418 | unsigned int cmd, unsigned long arg) |
| 2419 | { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2420 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2421 | int retval; |
| 2422 | |
| 2423 | switch (cmd) { |
| 2424 | case TIOCOUTQ: |
| 2425 | return put_user(tty_chars_in_buffer(tty), (int __user *) arg); |
| 2426 | case TIOCINQ: |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2427 | down_write(&tty->termios_rwsem); |
Linus Torvalds | 966031f | 2017-12-20 17:57:06 -0800 | [diff] [blame] | 2428 | if (L_ICANON(tty) && !L_EXTPROC(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2429 | retval = inq_canon(ldata); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2430 | else |
| 2431 | retval = read_cnt(ldata); |
| 2432 | up_write(&tty->termios_rwsem); |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2433 | return put_user(retval, (unsigned int __user *) arg); |
| 2434 | default: |
| 2435 | return n_tty_ioctl_helper(tty, file, cmd, arg); |
| 2436 | } |
| 2437 | } |
| 2438 | |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2439 | static struct tty_ldisc_ops n_tty_ops = { |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2440 | .magic = TTY_LDISC_MAGIC, |
| 2441 | .name = "n_tty", |
| 2442 | .open = n_tty_open, |
| 2443 | .close = n_tty_close, |
| 2444 | .flush_buffer = n_tty_flush_buffer, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2445 | .read = n_tty_read, |
| 2446 | .write = n_tty_write, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2447 | .ioctl = n_tty_ioctl, |
| 2448 | .set_termios = n_tty_set_termios, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2449 | .poll = n_tty_poll, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2450 | .receive_buf = n_tty_receive_buf, |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2451 | .write_wakeup = n_tty_write_wakeup, |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 2452 | .receive_buf2 = n_tty_receive_buf2, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2453 | }; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2454 | |
| 2455 | /** |
| 2456 | * n_tty_inherit_ops - inherit N_TTY methods |
| 2457 | * @ops: struct tty_ldisc_ops where to save N_TTY methods |
| 2458 | * |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2459 | * Enables a 'subclass' line discipline to 'inherit' N_TTY methods. |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2460 | */ |
| 2461 | |
| 2462 | void n_tty_inherit_ops(struct tty_ldisc_ops *ops) |
| 2463 | { |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2464 | *ops = n_tty_ops; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2465 | ops->owner = NULL; |
| 2466 | ops->refcount = ops->flags = 0; |
| 2467 | } |
| 2468 | EXPORT_SYMBOL_GPL(n_tty_inherit_ops); |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2469 | |
| 2470 | void __init n_tty_init(void) |
| 2471 | { |
| 2472 | tty_register_ldisc(N_TTY, &n_tty_ops); |
| 2473 | } |