Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * n_tty.c --- implements the N_TTY line discipline. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * This code used to be in tty_io.c, but things are getting hairy |
| 5 | * enough that it made sense to split things off. (The N_TTY |
| 6 | * processing has changed so much that it's hardly recognizable, |
| 7 | * anyway...) |
| 8 | * |
| 9 | * Note that the open routine for N_TTY is guaranteed never to return |
| 10 | * 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] | 11 | * 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] | 12 | * |
| 13 | * Written by Theodore Ts'o, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 14 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | * This file also contains code originally written by Linus Torvalds, |
| 16 | * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 17 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | * This file may be redistributed under the terms of the GNU General Public |
| 19 | * License. |
| 20 | * |
| 21 | * Reduced memory usage for older ARM systems - Russell King. |
| 22 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 23 | * 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] | 24 | * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu> |
| 25 | * who actually finally proved there really was a race. |
| 26 | * |
| 27 | * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to |
| 28 | * waiting writing processes-Sapan Bhatia <sapan@corewars.org>. |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 29 | * Also fixed a bug in BLOCKING mode where n_tty_write returns |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | * EAGAIN |
| 31 | */ |
| 32 | |
| 33 | #include <linux/types.h> |
| 34 | #include <linux/major.h> |
| 35 | #include <linux/errno.h> |
| 36 | #include <linux/signal.h> |
| 37 | #include <linux/fcntl.h> |
| 38 | #include <linux/sched.h> |
| 39 | #include <linux/interrupt.h> |
| 40 | #include <linux/tty.h> |
| 41 | #include <linux/timer.h> |
| 42 | #include <linux/ctype.h> |
| 43 | #include <linux/mm.h> |
| 44 | #include <linux/string.h> |
| 45 | #include <linux/slab.h> |
| 46 | #include <linux/poll.h> |
| 47 | #include <linux/bitops.h> |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 48 | #include <linux/audit.h> |
| 49 | #include <linux/file.h> |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 50 | #include <linux/uaccess.h> |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 51 | #include <linux/module.h> |
George Spelvin | 593fb1ae4 | 2013-02-12 02:00:43 -0500 | [diff] [blame] | 52 | #include <linux/ratelimit.h> |
Peter Hurley | 86e35ae | 2013-07-24 09:30:05 -0400 | [diff] [blame] | 53 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
| 56 | /* number of characters left in xmit buffer before select has we have room */ |
| 57 | #define WAKEUP_CHARS 256 |
| 58 | |
| 59 | /* |
| 60 | * This defines the low- and high-watermarks for throttling and |
| 61 | * unthrottling the TTY driver. These watermarks are used for |
| 62 | * controlling the space in the read buffer. |
| 63 | */ |
| 64 | #define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */ |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 65 | #define TTY_THRESHOLD_UNTHROTTLE 128 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 67 | /* |
| 68 | * Special byte codes used in the echo buffer to represent operations |
| 69 | * or special handling of characters. Bytes in the echo buffer that |
| 70 | * are not part of such special blocks are treated as normal character |
| 71 | * codes. |
| 72 | */ |
| 73 | #define ECHO_OP_START 0xff |
| 74 | #define ECHO_OP_MOVE_BACK_COL 0x80 |
| 75 | #define ECHO_OP_SET_CANON_COL 0x81 |
| 76 | #define ECHO_OP_ERASE_TAB 0x82 |
| 77 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 78 | #define ECHO_COMMIT_WATERMARK 256 |
| 79 | #define ECHO_BLOCK 256 |
| 80 | #define ECHO_DISCARD_WATERMARK N_TTY_BUF_SIZE - (ECHO_BLOCK + 32) |
| 81 | |
| 82 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 83 | #undef N_TTY_TRACE |
| 84 | #ifdef N_TTY_TRACE |
| 85 | # define n_tty_trace(f, args...) trace_printk(f, ##args) |
| 86 | #else |
| 87 | # define n_tty_trace(f, args...) |
| 88 | #endif |
| 89 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 90 | struct n_tty_data { |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 91 | /* producer-published */ |
| 92 | size_t read_head; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 93 | size_t commit_head; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 94 | size_t canon_head; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 95 | size_t echo_head; |
| 96 | size_t echo_commit; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 97 | size_t echo_mark; |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 98 | DECLARE_BITMAP(char_map, 256); |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 99 | |
| 100 | /* private to n_tty_receive_overrun (single-threaded) */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 101 | unsigned long overrun_time; |
| 102 | int num_overrun; |
| 103 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 104 | /* non-atomic */ |
| 105 | bool no_room; |
| 106 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 107 | /* must hold exclusive termios_rwsem to reset these */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 108 | 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] | 109 | unsigned char push:1; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 110 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 111 | /* shared by producer and consumer */ |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 112 | char read_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 113 | DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 114 | unsigned char echo_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 115 | |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 116 | int minimum_to_wake; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 117 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 118 | /* consumer-published */ |
| 119 | size_t read_tail; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 120 | size_t line_start; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 121 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 122 | /* protected by output lock */ |
| 123 | unsigned int column; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 124 | unsigned int canon_column; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 125 | size_t echo_tail; |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 126 | |
| 127 | struct mutex atomic_read_lock; |
| 128 | struct mutex output_lock; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 129 | }; |
| 130 | |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 131 | static inline size_t read_cnt(struct n_tty_data *ldata) |
| 132 | { |
Peter Hurley | a2f73be | 2013-06-15 09:14:22 -0400 | [diff] [blame] | 133 | return ldata->read_head - ldata->read_tail; |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 134 | } |
| 135 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 136 | static inline unsigned char read_buf(struct n_tty_data *ldata, size_t i) |
| 137 | { |
| 138 | return ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 139 | } |
| 140 | |
| 141 | static inline unsigned char *read_buf_addr(struct n_tty_data *ldata, size_t i) |
| 142 | { |
| 143 | return &ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 144 | } |
| 145 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 146 | static inline unsigned char echo_buf(struct n_tty_data *ldata, size_t i) |
| 147 | { |
| 148 | return ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 149 | } |
| 150 | |
| 151 | static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i) |
| 152 | { |
| 153 | return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 154 | } |
| 155 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 156 | static int tty_copy_to_user(struct tty_struct *tty, void __user *to, |
| 157 | size_t tail, size_t n) |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 158 | { |
| 159 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 160 | size_t size = N_TTY_BUF_SIZE - tail; |
| 161 | const void *from = read_buf_addr(ldata, tail); |
| 162 | int uncopied; |
| 163 | |
| 164 | if (n > size) { |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 165 | tty_audit_add_data(tty, from, size); |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 166 | uncopied = copy_to_user(to, from, size); |
| 167 | if (uncopied) |
| 168 | return uncopied; |
| 169 | to += size; |
| 170 | n -= size; |
| 171 | from = ldata->read_buf; |
| 172 | } |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 173 | |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 174 | tty_audit_add_data(tty, from, n); |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 175 | return copy_to_user(to, from, n); |
| 176 | } |
| 177 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 178 | /** |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 179 | * n_tty_kick_worker - start input worker (if required) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 180 | * @tty: terminal |
| 181 | * |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 182 | * Re-schedules the flip buffer work if it may have stopped |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 183 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 184 | * Caller holds exclusive termios_rwsem |
| 185 | * or |
| 186 | * n_tty_read()/consumer path: |
| 187 | * holds non-exclusive termios_rwsem |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 188 | */ |
| 189 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 190 | static void n_tty_kick_worker(struct tty_struct *tty) |
Peter Hurley | 7879a9f | 2013-06-15 07:28:31 -0400 | [diff] [blame] | 191 | { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 192 | struct n_tty_data *ldata = tty->disc_data; |
| 193 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 194 | /* Did the input worker stop? Restart it */ |
| 195 | if (unlikely(ldata->no_room)) { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 196 | ldata->no_room = 0; |
| 197 | |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 198 | WARN_RATELIMIT(tty->port->itty == NULL, |
Sasha Levin | cadf748 | 2012-10-25 14:26:35 -0400 | [diff] [blame] | 199 | "scheduling with invalid itty\n"); |
Peter Hurley | 2162293 | 2013-03-11 16:44:21 -0400 | [diff] [blame] | 200 | /* see if ldisc has been killed - if so, this means that |
| 201 | * even though the ldisc has been halted and ->buf.work |
| 202 | * cancelled, ->buf.work is about to be rescheduled |
| 203 | */ |
| 204 | WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags), |
| 205 | "scheduling buffer work for halted ldisc\n"); |
Peter Hurley | e176058 | 2015-10-17 16:36:23 -0400 | [diff] [blame] | 206 | tty_buffer_restart_work(tty->port); |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 207 | } |
Linus Torvalds | 55db4c6 | 2011-06-04 06:33:24 +0900 | [diff] [blame] | 208 | } |
| 209 | |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 210 | static ssize_t chars_in_buffer(struct tty_struct *tty) |
| 211 | { |
| 212 | struct n_tty_data *ldata = tty->disc_data; |
| 213 | ssize_t n = 0; |
| 214 | |
| 215 | if (!ldata->icanon) |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 216 | n = ldata->commit_head - ldata->read_tail; |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 217 | else |
| 218 | n = ldata->canon_head - ldata->read_tail; |
| 219 | return n; |
| 220 | } |
| 221 | |
Peter Hurley | ee0bab8 | 2013-06-15 09:14:34 -0400 | [diff] [blame] | 222 | /** |
| 223 | * n_tty_write_wakeup - asynchronous I/O notifier |
| 224 | * @tty: tty device |
| 225 | * |
| 226 | * Required for the ptys, serial driver etc. since processes |
| 227 | * that attach themselves to the master and rely on ASYNC |
| 228 | * IO must be woken up |
| 229 | */ |
| 230 | |
| 231 | static void n_tty_write_wakeup(struct tty_struct *tty) |
| 232 | { |
| 233 | if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) |
| 234 | kill_fasync(&tty->fasync, SIGIO, POLL_OUT); |
| 235 | } |
| 236 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 237 | static void n_tty_check_throttle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 238 | { |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 239 | struct n_tty_data *ldata = tty->disc_data; |
| 240 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 241 | /* |
| 242 | * Check the remaining room for the input canonicalization |
| 243 | * mode. We don't want to throttle the driver if we're in |
| 244 | * canonical mode and don't have a newline yet! |
| 245 | */ |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 246 | if (ldata->icanon && ldata->canon_head == ldata->read_tail) |
| 247 | return; |
| 248 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 249 | while (1) { |
| 250 | int throttled; |
| 251 | tty_set_flow_change(tty, TTY_THROTTLE_SAFE); |
Peter Hurley | 5e28cca | 2015-01-16 15:05:36 -0500 | [diff] [blame] | 252 | if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 253 | break; |
| 254 | throttled = tty_throttle_safe(tty); |
| 255 | if (!throttled) |
| 256 | break; |
| 257 | } |
| 258 | __tty_set_flow_change(tty, 0); |
| 259 | } |
| 260 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 261 | static void n_tty_check_unthrottle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 262 | { |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 263 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 264 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 265 | return; |
| 266 | if (!tty->count) |
| 267 | return; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 268 | n_tty_kick_worker(tty); |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 269 | tty_wakeup(tty->link); |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 270 | return; |
| 271 | } |
| 272 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 273 | /* If there is enough space in the read buffer now, let the |
| 274 | * low-level driver know. We use chars_in_buffer() to |
| 275 | * check the buffer, as it now knows about canonical mode. |
| 276 | * Otherwise, if the driver is throttled and the line is |
| 277 | * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, |
| 278 | * we won't get any more characters. |
| 279 | */ |
| 280 | |
| 281 | while (1) { |
| 282 | int unthrottled; |
| 283 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 284 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 285 | break; |
| 286 | if (!tty->count) |
| 287 | break; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 288 | n_tty_kick_worker(tty); |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 289 | unthrottled = tty_unthrottle_safe(tty); |
| 290 | if (!unthrottled) |
| 291 | break; |
| 292 | } |
| 293 | __tty_set_flow_change(tty, 0); |
| 294 | } |
| 295 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 296 | /** |
| 297 | * put_tty_queue - add character to tty |
| 298 | * @c: character |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 299 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 300 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 301 | * Add a character to the tty read_buf queue. |
| 302 | * |
| 303 | * n_tty_receive_buf()/producer path: |
| 304 | * caller holds non-exclusive termios_rwsem |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 305 | */ |
| 306 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 307 | 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] | 308 | { |
Christian Riesch | 8bfbe2d | 2014-11-13 05:53:26 +0100 | [diff] [blame] | 309 | *read_buf_addr(ldata, ldata->read_head) = c; |
| 310 | ldata->read_head++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | } |
| 312 | |
| 313 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | * reset_buffer_flags - reset buffer state |
| 315 | * @tty: terminal to reset |
| 316 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 317 | * Reset the read buffer counters and clear the flags. |
| 318 | * Called from n_tty_open() and n_tty_flush_buffer(). |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 319 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 320 | * Locking: caller holds exclusive termios_rwsem |
| 321 | * (or locking is not required) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 323 | |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 324 | static void reset_buffer_flags(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | { |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 326 | ldata->read_head = ldata->canon_head = ldata->read_tail = 0; |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 327 | ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 328 | ldata->commit_head = 0; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 329 | ldata->echo_mark = 0; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 330 | ldata->line_start = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 331 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 332 | ldata->erasing = 0; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 333 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 334 | ldata->push = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | } |
| 336 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 337 | static void n_tty_packet_mode_flush(struct tty_struct *tty) |
| 338 | { |
| 339 | unsigned long flags; |
| 340 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 341 | if (tty->link->packet) { |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 342 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 343 | tty->ctrl_status |= TIOCPKT_FLUSHREAD; |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 344 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 345 | wake_up_interruptible(&tty->link->read_wait); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 346 | } |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 347 | } |
| 348 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | /** |
| 350 | * n_tty_flush_buffer - clean input queue |
| 351 | * @tty: terminal device |
| 352 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 353 | * Flush the input buffer. Called when the tty layer wants the |
| 354 | * buffer flushed (eg at hangup) or when the N_TTY line discipline |
| 355 | * internally has to clean the pending queue (for example some signals). |
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 | * Holds termios_rwsem to exclude producer/consumer while |
| 358 | * buffer indices are reset. |
| 359 | * |
| 360 | * Locking: ctrl_lock, exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 362 | |
| 363 | static void n_tty_flush_buffer(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | { |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 365 | down_write(&tty->termios_rwsem); |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 366 | reset_buffer_flags(tty->disc_data); |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 367 | n_tty_kick_worker(tty); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 368 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 369 | if (tty->link) |
| 370 | n_tty_packet_mode_flush(tty); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 371 | up_write(&tty->termios_rwsem); |
| 372 | } |
| 373 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | * is_utf8_continuation - utf8 multibyte check |
| 376 | * @c: byte to check |
| 377 | * |
| 378 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 379 | * character. We use this to correctly compute the on screen size |
| 380 | * of the character when printing |
| 381 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 382 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | static inline int is_utf8_continuation(unsigned char c) |
| 384 | { |
| 385 | return (c & 0xc0) == 0x80; |
| 386 | } |
| 387 | |
| 388 | /** |
| 389 | * is_continuation - multibyte check |
| 390 | * @c: byte to check |
| 391 | * |
| 392 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 393 | * character and the terminal is in unicode mode. |
| 394 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 395 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | static inline int is_continuation(unsigned char c, struct tty_struct *tty) |
| 397 | { |
| 398 | return I_IUTF8(tty) && is_utf8_continuation(c); |
| 399 | } |
| 400 | |
| 401 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 402 | * do_output_char - output one character |
| 403 | * @c: character (or partial unicode symbol) |
| 404 | * @tty: terminal device |
| 405 | * @space: space available in tty driver write buffer |
| 406 | * |
| 407 | * This is a helper function that handles one output character |
| 408 | * (including special characters like TAB, CR, LF, etc.), |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 409 | * doing OPOST processing and putting the results in the |
| 410 | * tty driver's write buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 411 | * |
| 412 | * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY |
| 413 | * and NLDLY. They simply aren't relevant in the world today. |
| 414 | * If you ever need them, add them here. |
| 415 | * |
| 416 | * Returns the number of bytes of buffer space used or -1 if |
| 417 | * no space left. |
| 418 | * |
| 419 | * Locking: should be called under the output_lock to protect |
| 420 | * the column state and space left in the buffer |
| 421 | */ |
| 422 | |
| 423 | static int do_output_char(unsigned char c, struct tty_struct *tty, int space) |
| 424 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 425 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 426 | int spaces; |
| 427 | |
| 428 | if (!space) |
| 429 | return -1; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 430 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 431 | switch (c) { |
| 432 | case '\n': |
| 433 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 434 | ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 435 | if (O_ONLCR(tty)) { |
| 436 | if (space < 2) |
| 437 | return -1; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 438 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 37f81fa | 2009-09-05 12:46:07 -0700 | [diff] [blame] | 439 | tty->ops->write(tty, "\r\n", 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 440 | return 2; |
| 441 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 442 | ldata->canon_column = ldata->column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 443 | break; |
| 444 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 445 | if (O_ONOCR(tty) && ldata->column == 0) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 446 | return 0; |
| 447 | if (O_OCRNL(tty)) { |
| 448 | c = '\n'; |
| 449 | if (O_ONLRET(tty)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 450 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 451 | break; |
| 452 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 453 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 454 | break; |
| 455 | case '\t': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 456 | spaces = 8 - (ldata->column & 7); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 457 | if (O_TABDLY(tty) == XTABS) { |
| 458 | if (space < spaces) |
| 459 | return -1; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 460 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 461 | tty->ops->write(tty, " ", spaces); |
| 462 | return spaces; |
| 463 | } |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 464 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 465 | break; |
| 466 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 467 | if (ldata->column > 0) |
| 468 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 469 | break; |
| 470 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 471 | if (!iscntrl(c)) { |
| 472 | if (O_OLCUC(tty)) |
| 473 | c = toupper(c); |
| 474 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 475 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 476 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 477 | break; |
| 478 | } |
| 479 | |
| 480 | tty_put_char(tty, c); |
| 481 | return 1; |
| 482 | } |
| 483 | |
| 484 | /** |
| 485 | * process_output - output post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | * @c: character (or partial unicode symbol) |
| 487 | * @tty: terminal device |
| 488 | * |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 489 | * Output one character with OPOST processing. |
| 490 | * Returns -1 when the output device is full and the character |
| 491 | * must be retried. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 493 | * Locking: output_lock to protect column state and space left |
| 494 | * (also, this is called from n_tty_write under the |
| 495 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 497 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 498 | static int process_output(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 500 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 501 | int space, retval; |
| 502 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 503 | mutex_lock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 505 | space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 506 | retval = do_output_char(c, tty, space); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 508 | mutex_unlock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 509 | if (retval < 0) |
| 510 | return -1; |
| 511 | else |
| 512 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | } |
| 514 | |
| 515 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 516 | * process_output_block - block post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | * @tty: terminal device |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 518 | * @buf: character buffer |
| 519 | * @nr: number of bytes to output |
| 520 | * |
| 521 | * Output a block of characters with OPOST processing. |
| 522 | * Returns the number of characters output. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | * |
| 524 | * This path is used to speed up block console writes, among other |
| 525 | * things when processing blocks of output data. It handles only |
| 526 | * the simple cases normally found and helps to generate blocks of |
| 527 | * symbols for the console driver and thus improve performance. |
| 528 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 529 | * Locking: output_lock to protect column state and space left |
| 530 | * (also, this is called from n_tty_write under the |
| 531 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 533 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 534 | static ssize_t process_output_block(struct tty_struct *tty, |
| 535 | const unsigned char *buf, unsigned int nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 537 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | int space; |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 539 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | const unsigned char *cp; |
| 541 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 542 | mutex_lock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 543 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 544 | space = tty_write_room(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 545 | if (!space) { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 546 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | return 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 548 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | if (nr > space) |
| 550 | nr = space; |
| 551 | |
| 552 | for (i = 0, cp = buf; i < nr; i++, cp++) { |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 553 | unsigned char c = *cp; |
| 554 | |
| 555 | switch (c) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | case '\n': |
| 557 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 558 | ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | if (O_ONLCR(tty)) |
| 560 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 561 | ldata->canon_column = ldata->column; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | break; |
| 563 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 564 | if (O_ONOCR(tty) && ldata->column == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | goto break_out; |
| 566 | if (O_OCRNL(tty)) |
| 567 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 568 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | break; |
| 570 | case '\t': |
| 571 | goto break_out; |
| 572 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 573 | if (ldata->column > 0) |
| 574 | ldata->column--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | break; |
| 576 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 577 | if (!iscntrl(c)) { |
| 578 | if (O_OLCUC(tty)) |
| 579 | goto break_out; |
| 580 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 581 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 582 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | break; |
| 584 | } |
| 585 | } |
| 586 | break_out: |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 587 | i = tty->ops->write(tty, buf, i); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 588 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 589 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | return i; |
| 591 | } |
| 592 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 593 | /** |
| 594 | * process_echoes - write pending echo characters |
| 595 | * @tty: terminal device |
| 596 | * |
| 597 | * Write previously buffered echo (and other ldisc-generated) |
| 598 | * characters to the tty. |
| 599 | * |
| 600 | * Characters generated by the ldisc (including echoes) need to |
| 601 | * be buffered because the driver's write buffer can fill during |
| 602 | * heavy program output. Echoing straight to the driver will |
| 603 | * often fail under these conditions, causing lost characters and |
| 604 | * resulting mismatches of ldisc state information. |
| 605 | * |
| 606 | * Since the ldisc state must represent the characters actually sent |
| 607 | * to the driver at the time of the write, operations like certain |
| 608 | * changes in column state are also saved in the buffer and executed |
| 609 | * here. |
| 610 | * |
| 611 | * A circular fifo buffer is used so that the most recent characters |
| 612 | * are prioritized. Also, when control characters are echoed with a |
| 613 | * prefixed "^", the pair is treated atomically and thus not separated. |
| 614 | * |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 615 | * Locking: callers must hold output_lock |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 616 | */ |
| 617 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 618 | static size_t __process_echoes(struct tty_struct *tty) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 619 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 620 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 621 | int space, old_space; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 622 | size_t tail; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 623 | unsigned char c; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 624 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 625 | old_space = space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 626 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 627 | tail = ldata->echo_tail; |
Peter Hurley | 29c7c5c | 2013-06-15 10:04:28 -0400 | [diff] [blame] | 628 | while (ldata->echo_commit != tail) { |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 629 | c = echo_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 630 | if (c == ECHO_OP_START) { |
| 631 | unsigned char op; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 632 | int no_space_left = 0; |
| 633 | |
| 634 | /* |
| 635 | * If the buffer byte is the start of a multi-byte |
| 636 | * operation, get the next byte, which is either the |
| 637 | * op code or a control character value. |
| 638 | */ |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 639 | op = echo_buf(ldata, tail + 1); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 640 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 641 | switch (op) { |
| 642 | unsigned int num_chars, num_bs; |
| 643 | |
| 644 | case ECHO_OP_ERASE_TAB: |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 645 | num_chars = echo_buf(ldata, tail + 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 646 | |
| 647 | /* |
| 648 | * Determine how many columns to go back |
| 649 | * in order to erase the tab. |
| 650 | * This depends on the number of columns |
| 651 | * used by other characters within the tab |
| 652 | * area. If this (modulo 8) count is from |
| 653 | * the start of input rather than from a |
| 654 | * previous tab, we offset by canon column. |
| 655 | * Otherwise, tab spacing is normal. |
| 656 | */ |
| 657 | if (!(num_chars & 0x80)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 658 | num_chars += ldata->canon_column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 659 | num_bs = 8 - (num_chars & 7); |
| 660 | |
| 661 | if (num_bs > space) { |
| 662 | no_space_left = 1; |
| 663 | break; |
| 664 | } |
| 665 | space -= num_bs; |
| 666 | while (num_bs--) { |
| 667 | tty_put_char(tty, '\b'); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 668 | if (ldata->column > 0) |
| 669 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 670 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 671 | tail += 3; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 672 | break; |
| 673 | |
| 674 | case ECHO_OP_SET_CANON_COL: |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 675 | ldata->canon_column = ldata->column; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 676 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 677 | break; |
| 678 | |
| 679 | case ECHO_OP_MOVE_BACK_COL: |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 680 | if (ldata->column > 0) |
| 681 | ldata->column--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 682 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 683 | break; |
| 684 | |
| 685 | case ECHO_OP_START: |
| 686 | /* This is an escaped echo op start code */ |
| 687 | if (!space) { |
| 688 | no_space_left = 1; |
| 689 | break; |
| 690 | } |
| 691 | tty_put_char(tty, ECHO_OP_START); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 692 | ldata->column++; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 693 | space--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 694 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 695 | break; |
| 696 | |
| 697 | default: |
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 the op is not a special byte code, |
| 700 | * it is a ctrl char tagged to be echoed |
| 701 | * as "^X" (where X is the letter |
| 702 | * representing the control char). |
| 703 | * Note that we must ensure there is |
| 704 | * enough space for the whole ctrl pair. |
| 705 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 706 | */ |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 707 | if (space < 2) { |
| 708 | no_space_left = 1; |
| 709 | break; |
| 710 | } |
| 711 | tty_put_char(tty, '^'); |
| 712 | tty_put_char(tty, op ^ 0100); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 713 | ldata->column += 2; |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 714 | space -= 2; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 715 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 716 | } |
| 717 | |
| 718 | if (no_space_left) |
| 719 | break; |
| 720 | } else { |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 721 | if (O_OPOST(tty)) { |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 722 | int retval = do_output_char(c, tty, space); |
| 723 | if (retval < 0) |
| 724 | break; |
| 725 | space -= retval; |
| 726 | } else { |
| 727 | if (!space) |
| 728 | break; |
| 729 | tty_put_char(tty, c); |
| 730 | space -= 1; |
| 731 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 732 | tail += 1; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 733 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 734 | } |
| 735 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 736 | /* If the echo buffer is nearly full (so that the possibility exists |
| 737 | * of echo overrun before the next commit), then discard enough |
| 738 | * data at the tail to prevent a subsequent overrun */ |
| 739 | while (ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) { |
Roel Kluin | c476f65 | 2013-10-11 22:08:49 +0200 | [diff] [blame] | 740 | if (echo_buf(ldata, tail) == ECHO_OP_START) { |
Peter Hurley | 6f22253 | 2013-11-08 09:42:18 -0500 | [diff] [blame] | 741 | if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 742 | tail += 3; |
| 743 | else |
| 744 | tail += 2; |
| 745 | } else |
| 746 | tail++; |
| 747 | } |
| 748 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 749 | ldata->echo_tail = tail; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 750 | return old_space - space; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 751 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 753 | static void commit_echoes(struct tty_struct *tty) |
| 754 | { |
| 755 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 756 | size_t nr, old, echoed; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 757 | size_t head; |
| 758 | |
| 759 | head = ldata->echo_head; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 760 | ldata->echo_mark = head; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 761 | old = ldata->echo_commit - ldata->echo_tail; |
| 762 | |
| 763 | /* Process committed echoes if the accumulated # of bytes |
| 764 | * is over the threshold (and try again each time another |
| 765 | * block is accumulated) */ |
| 766 | nr = head - ldata->echo_tail; |
| 767 | if (nr < ECHO_COMMIT_WATERMARK || (nr % ECHO_BLOCK > old % ECHO_BLOCK)) |
| 768 | return; |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 769 | |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 770 | mutex_lock(&ldata->output_lock); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 771 | ldata->echo_commit = head; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 772 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 773 | mutex_unlock(&ldata->output_lock); |
| 774 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 775 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 776 | tty->ops->flush_chars(tty); |
| 777 | } |
| 778 | |
| 779 | static void process_echoes(struct tty_struct *tty) |
| 780 | { |
| 781 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 782 | size_t echoed; |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 783 | |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 784 | if (ldata->echo_mark == ldata->echo_tail) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 785 | return; |
| 786 | |
| 787 | mutex_lock(&ldata->output_lock); |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 788 | ldata->echo_commit = ldata->echo_mark; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 789 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 790 | mutex_unlock(&ldata->output_lock); |
| 791 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 792 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 793 | tty->ops->flush_chars(tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 794 | } |
| 795 | |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 796 | /* NB: echo_mark and echo_head should be equivalent here */ |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 797 | static void flush_echoes(struct tty_struct *tty) |
| 798 | { |
| 799 | struct n_tty_data *ldata = tty->disc_data; |
| 800 | |
Peter Hurley | 39434ab | 2013-11-29 12:56:10 -0500 | [diff] [blame] | 801 | if ((!L_ECHO(tty) && !L_ECHONL(tty)) || |
| 802 | ldata->echo_commit == ldata->echo_head) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 803 | return; |
| 804 | |
| 805 | mutex_lock(&ldata->output_lock); |
| 806 | ldata->echo_commit = ldata->echo_head; |
| 807 | __process_echoes(tty); |
| 808 | mutex_unlock(&ldata->output_lock); |
| 809 | } |
| 810 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 812 | * add_echo_byte - add a byte to the echo buffer |
| 813 | * @c: unicode byte to echo |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 814 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 815 | * |
| 816 | * Add a character or operation byte to the echo buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 817 | */ |
| 818 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 819 | 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] | 820 | { |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 821 | *echo_buf_addr(ldata, ldata->echo_head++) = c; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 822 | } |
| 823 | |
| 824 | /** |
| 825 | * echo_move_back_col - add operation to move back a column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 826 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 827 | * |
| 828 | * Add an operation to the echo buffer to move back one column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 829 | */ |
| 830 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 831 | static void echo_move_back_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 832 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 833 | add_echo_byte(ECHO_OP_START, ldata); |
| 834 | add_echo_byte(ECHO_OP_MOVE_BACK_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 835 | } |
| 836 | |
| 837 | /** |
| 838 | * echo_set_canon_col - add operation to set the canon column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 839 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 840 | * |
| 841 | * Add an operation to the echo buffer to set the canon column |
| 842 | * to the current column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 843 | */ |
| 844 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 845 | static void echo_set_canon_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 846 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 847 | add_echo_byte(ECHO_OP_START, ldata); |
| 848 | add_echo_byte(ECHO_OP_SET_CANON_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 849 | } |
| 850 | |
| 851 | /** |
| 852 | * echo_erase_tab - add operation to erase a tab |
| 853 | * @num_chars: number of character columns already used |
| 854 | * @after_tab: true if num_chars starts after a previous tab |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 855 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 856 | * |
| 857 | * Add an operation to the echo buffer to erase a tab. |
| 858 | * |
| 859 | * Called by the eraser function, which knows how many character |
| 860 | * columns have been used since either a previous tab or the start |
| 861 | * of input. This information will be used later, along with |
| 862 | * canon column (if applicable), to go back the correct number |
| 863 | * of columns. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 864 | */ |
| 865 | |
| 866 | static void echo_erase_tab(unsigned int num_chars, int after_tab, |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 867 | struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 868 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 869 | add_echo_byte(ECHO_OP_START, ldata); |
| 870 | add_echo_byte(ECHO_OP_ERASE_TAB, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 871 | |
| 872 | /* We only need to know this modulo 8 (tab spacing) */ |
| 873 | num_chars &= 7; |
| 874 | |
| 875 | /* Set the high bit as a flag if num_chars is after a previous tab */ |
| 876 | if (after_tab) |
| 877 | num_chars |= 0x80; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 878 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 879 | add_echo_byte(num_chars, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 880 | } |
| 881 | |
| 882 | /** |
| 883 | * echo_char_raw - echo a character raw |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | * @c: unicode byte to echo |
| 885 | * @tty: terminal device |
| 886 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 887 | * 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] | 888 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 889 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 890 | * This variant does not treat control characters specially. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 891 | */ |
| 892 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 893 | 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] | 894 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 895 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 896 | add_echo_byte(ECHO_OP_START, ldata); |
| 897 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 898 | } else { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 899 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 900 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 901 | } |
| 902 | |
| 903 | /** |
| 904 | * echo_char - echo a character |
| 905 | * @c: unicode byte to echo |
| 906 | * @tty: terminal device |
| 907 | * |
| 908 | * Echo user input back onto the screen. This must be called only when |
| 909 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
| 910 | * |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 911 | * This variant tags control characters to be echoed as "^X" |
| 912 | * (where X is the letter representing the control char). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | */ |
| 914 | |
| 915 | static void echo_char(unsigned char c, struct tty_struct *tty) |
| 916 | { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 917 | struct n_tty_data *ldata = tty->disc_data; |
| 918 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 919 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 920 | add_echo_byte(ECHO_OP_START, ldata); |
| 921 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 922 | } else { |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 923 | if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 924 | add_echo_byte(ECHO_OP_START, ldata); |
| 925 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 926 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | } |
| 928 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 929 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 930 | * finish_erasing - complete erase |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 931 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 932 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 933 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 934 | static inline void finish_erasing(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 936 | if (ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 937 | echo_char_raw('/', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 938 | ldata->erasing = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | } |
| 940 | } |
| 941 | |
| 942 | /** |
| 943 | * eraser - handle erase function |
| 944 | * @c: character input |
| 945 | * @tty: terminal device |
| 946 | * |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 947 | * Perform erase and necessary output when an erase character is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | * present in the stream from the driver layer. Handles the complexities |
| 949 | * of UTF-8 multibyte symbols. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 950 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 951 | * n_tty_receive_buf()/producer path: |
| 952 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 954 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | static void eraser(unsigned char c, struct tty_struct *tty) |
| 956 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 957 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | enum { ERASE, WERASE, KILL } kill_type; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 959 | size_t head; |
| 960 | size_t cnt; |
| 961 | int seen_alnums; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 963 | if (ldata->read_head == ldata->canon_head) { |
Joe Peterson | 7e94b1d | 2009-01-02 13:43:40 +0000 | [diff] [blame] | 964 | /* process_output('\a', tty); */ /* what do you think? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | return; |
| 966 | } |
| 967 | if (c == ERASE_CHAR(tty)) |
| 968 | kill_type = ERASE; |
| 969 | else if (c == WERASE_CHAR(tty)) |
| 970 | kill_type = WERASE; |
| 971 | else { |
| 972 | if (!L_ECHO(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 973 | ldata->read_head = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | return; |
| 975 | } |
| 976 | if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 977 | ldata->read_head = ldata->canon_head; |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 978 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | echo_char(KILL_CHAR(tty), tty); |
| 980 | /* Add a newline if ECHOK is on and ECHOKE is off. */ |
| 981 | if (L_ECHOK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 982 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | return; |
| 984 | } |
| 985 | kill_type = KILL; |
| 986 | } |
| 987 | |
| 988 | seen_alnums = 0; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 989 | while (ldata->read_head != ldata->canon_head) { |
| 990 | head = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | |
| 992 | /* erase a single possibly multibyte character */ |
| 993 | do { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 994 | head--; |
| 995 | c = read_buf(ldata, head); |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 996 | } while (is_continuation(c, tty) && head != ldata->canon_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | |
| 998 | /* do not partially erase */ |
| 999 | if (is_continuation(c, tty)) |
| 1000 | break; |
| 1001 | |
| 1002 | if (kill_type == WERASE) { |
| 1003 | /* Equivalent to BSD's ALTWERASE. */ |
| 1004 | if (isalnum(c) || c == '_') |
| 1005 | seen_alnums++; |
| 1006 | else if (seen_alnums) |
| 1007 | break; |
| 1008 | } |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1009 | cnt = ldata->read_head - head; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1010 | ldata->read_head = head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | if (L_ECHO(tty)) { |
| 1012 | if (L_ECHOPRT(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1013 | if (!ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1014 | echo_char_raw('\\', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1015 | ldata->erasing = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | } |
| 1017 | /* if cnt > 1, output a multi-byte character */ |
| 1018 | echo_char(c, tty); |
| 1019 | while (--cnt > 0) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1020 | head++; |
| 1021 | echo_char_raw(read_buf(ldata, head), ldata); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1022 | echo_move_back_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | } |
| 1024 | } else if (kill_type == ERASE && !L_ECHOE(tty)) { |
| 1025 | echo_char(ERASE_CHAR(tty), tty); |
| 1026 | } else if (c == '\t') { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1027 | unsigned int num_chars = 0; |
| 1028 | int after_tab = 0; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1029 | size_t tail = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1031 | /* |
| 1032 | * Count the columns used for characters |
| 1033 | * since the start of input or after a |
| 1034 | * previous tab. |
| 1035 | * This info is used to go back the correct |
| 1036 | * number of columns. |
| 1037 | */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1038 | while (tail != ldata->canon_head) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1039 | tail--; |
| 1040 | c = read_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1041 | if (c == '\t') { |
| 1042 | after_tab = 1; |
| 1043 | break; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 1044 | } else if (iscntrl(c)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1045 | if (L_ECHOCTL(tty)) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1046 | num_chars += 2; |
| 1047 | } else if (!is_continuation(c, tty)) { |
| 1048 | num_chars++; |
| 1049 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1051 | echo_erase_tab(num_chars, after_tab, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1052 | } else { |
| 1053 | if (iscntrl(c) && L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1054 | echo_char_raw('\b', ldata); |
| 1055 | echo_char_raw(' ', ldata); |
| 1056 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1057 | } |
| 1058 | if (!iscntrl(c) || L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1059 | echo_char_raw('\b', ldata); |
| 1060 | echo_char_raw(' ', ldata); |
| 1061 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1062 | } |
| 1063 | } |
| 1064 | } |
| 1065 | if (kill_type == ERASE) |
| 1066 | break; |
| 1067 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1068 | if (ldata->read_head == ldata->canon_head && L_ECHO(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1069 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | } |
| 1071 | |
| 1072 | /** |
| 1073 | * isig - handle the ISIG optio |
| 1074 | * @sig: signal |
| 1075 | * @tty: terminal |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1077 | * Called when a signal is being sent due to terminal input. |
| 1078 | * Called from the driver receive_buf path so serialized. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1079 | * |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1080 | * Performs input and output flush if !NOFLSH. In this context, the echo |
| 1081 | * buffer is 'output'. The signal is processed first to alert any current |
| 1082 | * readers or writers to discontinue and exit their i/o loops. |
| 1083 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1084 | * Locking: ctrl_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1086 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1087 | static void __isig(int sig, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1089 | struct pid *tty_pgrp = tty_get_pgrp(tty); |
| 1090 | if (tty_pgrp) { |
| 1091 | kill_pgrp(tty_pgrp, sig, 1); |
| 1092 | put_pid(tty_pgrp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | } |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1094 | } |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1095 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1096 | static void isig(int sig, struct tty_struct *tty) |
| 1097 | { |
| 1098 | struct n_tty_data *ldata = tty->disc_data; |
| 1099 | |
| 1100 | if (L_NOFLSH(tty)) { |
| 1101 | /* signal only */ |
| 1102 | __isig(sig, tty); |
| 1103 | |
| 1104 | } else { /* signal and flush */ |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1105 | up_read(&tty->termios_rwsem); |
| 1106 | down_write(&tty->termios_rwsem); |
| 1107 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1108 | __isig(sig, tty); |
| 1109 | |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1110 | /* clear echo buffer */ |
| 1111 | mutex_lock(&ldata->output_lock); |
| 1112 | ldata->echo_head = ldata->echo_tail = 0; |
| 1113 | ldata->echo_mark = ldata->echo_commit = 0; |
| 1114 | mutex_unlock(&ldata->output_lock); |
| 1115 | |
| 1116 | /* clear output buffer */ |
| 1117 | tty_driver_flush_buffer(tty); |
| 1118 | |
| 1119 | /* clear input buffer */ |
| 1120 | reset_buffer_flags(tty->disc_data); |
| 1121 | |
| 1122 | /* notify pty master of flush */ |
| 1123 | if (tty->link) |
| 1124 | n_tty_packet_mode_flush(tty); |
| 1125 | |
| 1126 | up_write(&tty->termios_rwsem); |
| 1127 | down_read(&tty->termios_rwsem); |
| 1128 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1129 | } |
| 1130 | |
| 1131 | /** |
| 1132 | * n_tty_receive_break - handle break |
| 1133 | * @tty: terminal |
| 1134 | * |
| 1135 | * An RS232 break event has been hit in the incoming bitstream. This |
| 1136 | * can cause a variety of events depending upon the termios settings. |
| 1137 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1138 | * n_tty_receive_buf()/producer path: |
| 1139 | * caller holds non-exclusive termios_rwsem |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1140 | * |
| 1141 | * Note: may get exclusive termios_rwsem if flushing input buffer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1143 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1144 | static void n_tty_receive_break(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1146 | struct n_tty_data *ldata = tty->disc_data; |
| 1147 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | if (I_IGNBRK(tty)) |
| 1149 | return; |
| 1150 | if (I_BRKINT(tty)) { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1151 | isig(SIGINT, tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | return; |
| 1153 | } |
| 1154 | if (I_PARMRK(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1155 | put_tty_queue('\377', ldata); |
| 1156 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1158 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | } |
| 1160 | |
| 1161 | /** |
| 1162 | * n_tty_receive_overrun - handle overrun reporting |
| 1163 | * @tty: terminal |
| 1164 | * |
| 1165 | * Data arrived faster than we could process it. While the tty |
| 1166 | * driver has flagged this the bits that were missed are gone |
| 1167 | * forever. |
| 1168 | * |
| 1169 | * Called from the receive_buf path so single threaded. Does not |
| 1170 | * need locking as num_overrun and overrun_time are function |
| 1171 | * private. |
| 1172 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1173 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1174 | static void n_tty_receive_overrun(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1175 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1176 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1177 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1178 | ldata->num_overrun++; |
| 1179 | if (time_after(jiffies, ldata->overrun_time + HZ) || |
| 1180 | time_after(ldata->overrun_time, jiffies)) { |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1181 | tty_warn(tty, "%d input overrun(s)\n", ldata->num_overrun); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1182 | ldata->overrun_time = jiffies; |
| 1183 | ldata->num_overrun = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | } |
| 1185 | } |
| 1186 | |
| 1187 | /** |
| 1188 | * n_tty_receive_parity_error - error notifier |
| 1189 | * @tty: terminal device |
| 1190 | * @c: character |
| 1191 | * |
| 1192 | * Process a parity error and queue the right data to indicate |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1193 | * the error case if necessary. |
| 1194 | * |
| 1195 | * n_tty_receive_buf()/producer path: |
| 1196 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1197 | */ |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1198 | 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] | 1199 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1200 | struct n_tty_data *ldata = tty->disc_data; |
| 1201 | |
Peter Hurley | 66528f9 | 2014-06-16 08:10:42 -0400 | [diff] [blame] | 1202 | if (I_INPCK(tty)) { |
| 1203 | if (I_IGNPAR(tty)) |
| 1204 | return; |
| 1205 | if (I_PARMRK(tty)) { |
| 1206 | put_tty_queue('\377', ldata); |
| 1207 | put_tty_queue('\0', ldata); |
| 1208 | put_tty_queue(c, ldata); |
| 1209 | } else |
| 1210 | put_tty_queue('\0', ldata); |
| 1211 | } else |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1212 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1213 | } |
| 1214 | |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1215 | static void |
| 1216 | n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c) |
| 1217 | { |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1218 | isig(signal, tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1219 | if (I_IXON(tty)) |
| 1220 | start_tty(tty); |
| 1221 | if (L_ECHO(tty)) { |
| 1222 | echo_char(c, tty); |
| 1223 | commit_echoes(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1224 | } else |
| 1225 | process_echoes(tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1226 | return; |
| 1227 | } |
| 1228 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1229 | /** |
| 1230 | * n_tty_receive_char - perform processing |
| 1231 | * @tty: terminal device |
| 1232 | * @c: character |
| 1233 | * |
| 1234 | * Process an individual character of input received from the driver. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1235 | * This is serialized with respect to itself by the rules for the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | * driver above. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1237 | * |
| 1238 | * n_tty_receive_buf()/producer path: |
| 1239 | * caller holds non-exclusive termios_rwsem |
| 1240 | * publishes canon_head if canonical mode is active |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1241 | * |
| 1242 | * Returns 1 if LNEXT was received, else returns 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | */ |
| 1244 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1245 | static int |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1246 | n_tty_receive_char_special(struct tty_struct *tty, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1248 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1249 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1250 | if (I_IXON(tty)) { |
| 1251 | if (c == START_CHAR(tty)) { |
| 1252 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1253 | process_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1254 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | } |
| 1256 | if (c == STOP_CHAR(tty)) { |
| 1257 | stop_tty(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1258 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | } |
| 1260 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1262 | if (L_ISIG(tty)) { |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1263 | if (c == INTR_CHAR(tty)) { |
| 1264 | n_tty_receive_signal_char(tty, SIGINT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1265 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1266 | } else if (c == QUIT_CHAR(tty)) { |
| 1267 | n_tty_receive_signal_char(tty, SIGQUIT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1268 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1269 | } else if (c == SUSP_CHAR(tty)) { |
| 1270 | n_tty_receive_signal_char(tty, SIGTSTP, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1271 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | } |
| 1273 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1274 | |
Peter Hurley | 855df3c | 2013-07-24 08:29:50 -0400 | [diff] [blame] | 1275 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1276 | start_tty(tty); |
| 1277 | process_echoes(tty); |
| 1278 | } |
| 1279 | |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1280 | if (c == '\r') { |
| 1281 | if (I_IGNCR(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1282 | return 0; |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1283 | if (I_ICRNL(tty)) |
| 1284 | c = '\n'; |
| 1285 | } else if (c == '\n' && I_INLCR(tty)) |
| 1286 | c = '\r'; |
| 1287 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1288 | if (ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) || |
| 1290 | (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) { |
| 1291 | eraser(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1292 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1293 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1294 | } |
| 1295 | if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1296 | ldata->lnext = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1297 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1298 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1299 | if (L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1300 | echo_char_raw('^', ldata); |
| 1301 | echo_char_raw('\b', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1302 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | } |
| 1304 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1305 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1307 | if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1308 | size_t tail = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1310 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | echo_char(c, tty); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1312 | echo_char_raw('\n', ldata); |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1313 | while (tail != ldata->read_head) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1314 | echo_char(read_buf(ldata, tail), tty); |
| 1315 | tail++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1317 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1318 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | } |
| 1320 | if (c == '\n') { |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1321 | if (L_ECHO(tty) || L_ECHONL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1322 | echo_char_raw('\n', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1323 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | } |
| 1325 | goto handle_newline; |
| 1326 | } |
| 1327 | if (c == EOF_CHAR(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1328 | c = __DISABLED_CHAR; |
| 1329 | goto handle_newline; |
| 1330 | } |
| 1331 | if ((c == EOL_CHAR(tty)) || |
| 1332 | (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) { |
| 1333 | /* |
| 1334 | * XXX are EOL_CHAR and EOL2_CHAR echoed?!? |
| 1335 | */ |
| 1336 | if (L_ECHO(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1338 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1339 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | echo_char(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1341 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1342 | } |
| 1343 | /* |
| 1344 | * XXX does PARMRK doubling happen for |
| 1345 | * EOL_CHAR and EOL2_CHAR? |
| 1346 | */ |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1347 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1348 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1350 | handle_newline: |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1351 | 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] | 1352 | put_tty_queue(c, ldata); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1353 | smp_store_release(&ldata->canon_head, ldata->read_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1355 | wake_up_interruptible_poll(&tty->read_wait, POLLIN); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1356 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | } |
| 1358 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1359 | |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1360 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1361 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | if (c == '\n') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1363 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | else { |
| 1365 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1366 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1367 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | echo_char(c, tty); |
| 1369 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1370 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1371 | } |
| 1372 | |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1373 | /* PARMRK doubling check */ |
| 1374 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1375 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1376 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1377 | put_tty_queue(c, ldata); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1378 | return 0; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1379 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1381 | static inline void |
| 1382 | n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c) |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1383 | { |
| 1384 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1385 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1386 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1387 | start_tty(tty); |
| 1388 | process_echoes(tty); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1389 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1390 | if (L_ECHO(tty)) { |
| 1391 | finish_erasing(ldata); |
| 1392 | /* Record the column of first canon char. */ |
| 1393 | if (ldata->canon_head == ldata->read_head) |
| 1394 | echo_set_canon_col(ldata); |
| 1395 | echo_char(c, tty); |
| 1396 | commit_echoes(tty); |
| 1397 | } |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1398 | /* PARMRK doubling check */ |
| 1399 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1400 | put_tty_queue(c, ldata); |
| 1401 | put_tty_queue(c, ldata); |
| 1402 | } |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1403 | |
Peter Hurley | eb3e466 | 2013-12-02 14:24:42 -0500 | [diff] [blame] | 1404 | 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] | 1405 | { |
| 1406 | n_tty_receive_char_inline(tty, c); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1407 | } |
| 1408 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1409 | static inline void |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1410 | n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c) |
| 1411 | { |
| 1412 | struct n_tty_data *ldata = tty->disc_data; |
| 1413 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1414 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1415 | start_tty(tty); |
| 1416 | process_echoes(tty); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1417 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1418 | if (L_ECHO(tty)) { |
| 1419 | finish_erasing(ldata); |
| 1420 | /* Record the column of first canon char. */ |
| 1421 | if (ldata->canon_head == ldata->read_head) |
| 1422 | echo_set_canon_col(ldata); |
| 1423 | echo_char(c, tty); |
| 1424 | commit_echoes(tty); |
| 1425 | } |
| 1426 | put_tty_queue(c, ldata); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1427 | } |
| 1428 | |
Peter Hurley | 8dc4b25 | 2013-12-02 14:24:43 -0500 | [diff] [blame] | 1429 | 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] | 1430 | { |
| 1431 | if (I_ISTRIP(tty)) |
| 1432 | c &= 0x7f; |
| 1433 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1434 | c = tolower(c); |
| 1435 | |
| 1436 | if (I_IXON(tty)) { |
| 1437 | if (c == STOP_CHAR(tty)) |
| 1438 | stop_tty(tty); |
| 1439 | else if (c == START_CHAR(tty) || |
| 1440 | (tty->stopped && !tty->flow_stopped && I_IXANY(tty) && |
| 1441 | c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && |
| 1442 | c != SUSP_CHAR(tty))) { |
| 1443 | start_tty(tty); |
| 1444 | process_echoes(tty); |
| 1445 | } |
| 1446 | } |
| 1447 | } |
| 1448 | |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1449 | static void |
| 1450 | n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag) |
| 1451 | { |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1452 | switch (flag) { |
| 1453 | case TTY_BREAK: |
| 1454 | n_tty_receive_break(tty); |
| 1455 | break; |
| 1456 | case TTY_PARITY: |
| 1457 | case TTY_FRAME: |
| 1458 | n_tty_receive_parity_error(tty, c); |
| 1459 | break; |
| 1460 | case TTY_OVERRUN: |
| 1461 | n_tty_receive_overrun(tty); |
| 1462 | break; |
| 1463 | default: |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1464 | tty_err(tty, "unknown flag %d\n", flag); |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1465 | break; |
| 1466 | } |
| 1467 | } |
| 1468 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1469 | static void |
| 1470 | n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag) |
| 1471 | { |
| 1472 | struct n_tty_data *ldata = tty->disc_data; |
| 1473 | |
| 1474 | ldata->lnext = 0; |
| 1475 | if (likely(flag == TTY_NORMAL)) { |
| 1476 | if (I_ISTRIP(tty)) |
| 1477 | c &= 0x7f; |
| 1478 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1479 | c = tolower(c); |
| 1480 | n_tty_receive_char(tty, c); |
| 1481 | } else |
| 1482 | n_tty_receive_char_flagged(tty, c, flag); |
| 1483 | } |
| 1484 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1485 | static void |
| 1486 | n_tty_receive_buf_real_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1487 | char *fp, int count) |
| 1488 | { |
| 1489 | struct n_tty_data *ldata = tty->disc_data; |
| 1490 | size_t n, head; |
| 1491 | |
| 1492 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1493 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1494 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1495 | ldata->read_head += n; |
| 1496 | cp += n; |
| 1497 | count -= n; |
| 1498 | |
| 1499 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1500 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1501 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1502 | ldata->read_head += n; |
| 1503 | } |
| 1504 | |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1505 | static void |
| 1506 | n_tty_receive_buf_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1507 | char *fp, int count) |
| 1508 | { |
| 1509 | struct n_tty_data *ldata = tty->disc_data; |
| 1510 | char flag = TTY_NORMAL; |
| 1511 | |
| 1512 | while (count--) { |
| 1513 | if (fp) |
| 1514 | flag = *fp++; |
| 1515 | if (likely(flag == TTY_NORMAL)) |
| 1516 | put_tty_queue(*cp++, ldata); |
| 1517 | else |
| 1518 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1519 | } |
| 1520 | } |
| 1521 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1522 | static void |
| 1523 | n_tty_receive_buf_closing(struct tty_struct *tty, const unsigned char *cp, |
| 1524 | char *fp, int count) |
| 1525 | { |
| 1526 | char flag = TTY_NORMAL; |
| 1527 | |
| 1528 | while (count--) { |
| 1529 | if (fp) |
| 1530 | flag = *fp++; |
| 1531 | if (likely(flag == TTY_NORMAL)) |
| 1532 | n_tty_receive_char_closing(tty, *cp++); |
| 1533 | else |
| 1534 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1535 | } |
| 1536 | } |
| 1537 | |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1538 | static void |
| 1539 | 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] | 1540 | char *fp, int count) |
| 1541 | { |
| 1542 | struct n_tty_data *ldata = tty->disc_data; |
| 1543 | char flag = TTY_NORMAL; |
| 1544 | |
| 1545 | while (count--) { |
| 1546 | if (fp) |
| 1547 | flag = *fp++; |
| 1548 | if (likely(flag == TTY_NORMAL)) { |
| 1549 | unsigned char c = *cp++; |
| 1550 | |
| 1551 | if (I_ISTRIP(tty)) |
| 1552 | c &= 0x7f; |
| 1553 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1554 | c = tolower(c); |
| 1555 | if (L_EXTPROC(tty)) { |
| 1556 | put_tty_queue(c, ldata); |
| 1557 | continue; |
| 1558 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1559 | if (!test_bit(c, ldata->char_map)) |
| 1560 | n_tty_receive_char_inline(tty, c); |
| 1561 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1562 | if (fp) |
| 1563 | flag = *fp++; |
| 1564 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1565 | count--; |
| 1566 | } |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1567 | } else |
| 1568 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1569 | } |
| 1570 | } |
| 1571 | |
| 1572 | static void |
| 1573 | n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp, |
| 1574 | char *fp, int count) |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1575 | { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1576 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1577 | char flag = TTY_NORMAL; |
| 1578 | |
| 1579 | while (count--) { |
| 1580 | if (fp) |
| 1581 | flag = *fp++; |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1582 | if (likely(flag == TTY_NORMAL)) { |
| 1583 | unsigned char c = *cp++; |
| 1584 | |
| 1585 | if (!test_bit(c, ldata->char_map)) |
| 1586 | n_tty_receive_char_fast(tty, c); |
| 1587 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1588 | if (fp) |
| 1589 | flag = *fp++; |
| 1590 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1591 | count--; |
| 1592 | } |
| 1593 | } else |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1594 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1595 | } |
| 1596 | } |
| 1597 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1598 | static void __receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1599 | char *fp, int count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1600 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1601 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1602 | bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1604 | if (ldata->real_raw) |
| 1605 | n_tty_receive_buf_real_raw(tty, cp, fp, count); |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1606 | else if (ldata->raw || (L_EXTPROC(tty) && !preops)) |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1607 | n_tty_receive_buf_raw(tty, cp, fp, count); |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1608 | else if (tty->closing && !L_EXTPROC(tty)) |
| 1609 | n_tty_receive_buf_closing(tty, cp, fp, count); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1610 | else { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1611 | if (ldata->lnext) { |
| 1612 | char flag = TTY_NORMAL; |
| 1613 | |
| 1614 | if (fp) |
| 1615 | flag = *fp++; |
| 1616 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1617 | count--; |
| 1618 | } |
| 1619 | |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1620 | if (!preops && !I_PARMRK(tty)) |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1621 | n_tty_receive_buf_fast(tty, cp, fp, count); |
| 1622 | else |
| 1623 | n_tty_receive_buf_standard(tty, cp, fp, count); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 1624 | |
| 1625 | flush_echoes(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1626 | if (tty->ops->flush_chars) |
| 1627 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1628 | } |
| 1629 | |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1630 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1631 | return; |
| 1632 | |
| 1633 | /* publish read_head to consumer */ |
| 1634 | smp_store_release(&ldata->commit_head, ldata->read_head); |
| 1635 | |
| 1636 | if ((read_cnt(ldata) >= ldata->minimum_to_wake) || L_EXTPROC(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1637 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1638 | wake_up_interruptible_poll(&tty->read_wait, POLLIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1639 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1640 | } |
| 1641 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1642 | /** |
| 1643 | * n_tty_receive_buf_common - process input |
| 1644 | * @tty: device to receive input |
| 1645 | * @cp: input chars |
| 1646 | * @fp: flags for each char (if NULL, all chars are TTY_NORMAL) |
| 1647 | * @count: number of input chars in @cp |
| 1648 | * |
| 1649 | * Called by the terminal driver when a block of characters has |
| 1650 | * been received. This function must be called from soft contexts |
| 1651 | * not from interrupt context. The driver is responsible for making |
| 1652 | * calls one at a time and in order (or using flush_to_ldisc) |
| 1653 | * |
| 1654 | * Returns the # of input chars from @cp which were processed. |
| 1655 | * |
| 1656 | * In canonical mode, the maximum line length is 4096 chars (including |
| 1657 | * the line termination char); lines longer than 4096 chars are |
| 1658 | * truncated. After 4095 chars, input data is still processed but |
| 1659 | * not stored. Overflow processing ensures the tty can always |
| 1660 | * receive more input until at least one line can be read. |
| 1661 | * |
| 1662 | * In non-canonical mode, the read buffer will only accept 4095 chars; |
| 1663 | * this provides the necessary space for a newline char if the input |
| 1664 | * mode is switched to canonical. |
| 1665 | * |
| 1666 | * Note it is possible for the read buffer to _contain_ 4096 chars |
| 1667 | * in non-canonical mode: the read buffer could already contain the |
| 1668 | * maximum canon line of 4096 chars when the mode is switched to |
| 1669 | * non-canonical. |
| 1670 | * |
| 1671 | * n_tty_receive_buf()/producer path: |
| 1672 | * claims non-exclusive termios_rwsem |
| 1673 | * publishes commit_head or canon_head |
| 1674 | */ |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1675 | static int |
| 1676 | n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp, |
| 1677 | char *fp, int count, int flow) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1678 | { |
| 1679 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1680 | int room, n, rcvd = 0, overflow; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1681 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1682 | down_read(&tty->termios_rwsem); |
| 1683 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1684 | while (1) { |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1685 | /* |
Peter Hurley | 06c49f9 | 2015-01-16 15:05:38 -0500 | [diff] [blame] | 1686 | * When PARMRK is set, each input char may take up to 3 chars |
| 1687 | * in the read buf; reduce the buffer space avail by 3x |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1688 | * |
| 1689 | * If we are doing input canonicalization, and there are no |
| 1690 | * pending newlines, let characters through without limit, so |
| 1691 | * that erase characters will be handled. Other excess |
| 1692 | * characters will be beeped. |
| 1693 | * |
| 1694 | * paired with store in *_copy_from_read_buf() -- guarantees |
| 1695 | * the consumer has loaded the data in read_buf up to the new |
| 1696 | * read_tail (so this producer will not overwrite unread data) |
| 1697 | */ |
| 1698 | size_t tail = smp_load_acquire(&ldata->read_tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1699 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1700 | room = N_TTY_BUF_SIZE - (ldata->read_head - tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1701 | if (I_PARMRK(tty)) |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1702 | room = (room + 2) / 3; |
| 1703 | room--; |
| 1704 | if (room <= 0) { |
| 1705 | overflow = ldata->icanon && ldata->canon_head == tail; |
| 1706 | if (overflow && room < 0) |
| 1707 | ldata->read_head--; |
| 1708 | room = overflow; |
| 1709 | ldata->no_room = flow && !room; |
| 1710 | } else |
| 1711 | overflow = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1712 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1713 | n = min(count, room); |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1714 | if (!n) |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1715 | break; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1716 | |
| 1717 | /* ignore parity errors if handling overflow */ |
| 1718 | if (!overflow || !fp || *fp != TTY_PARITY) |
| 1719 | __receive_buf(tty, cp, fp, n); |
| 1720 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1721 | cp += n; |
| 1722 | if (fp) |
| 1723 | fp += n; |
| 1724 | count -= n; |
| 1725 | rcvd += n; |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1726 | } |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1727 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1728 | tty->receive_room = room; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1729 | |
| 1730 | /* Unthrottle if handling overflow on pty */ |
| 1731 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
| 1732 | if (overflow) { |
| 1733 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 1734 | tty_unthrottle_safe(tty); |
| 1735 | __tty_set_flow_change(tty, 0); |
| 1736 | } |
| 1737 | } else |
| 1738 | n_tty_check_throttle(tty); |
| 1739 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1740 | up_read(&tty->termios_rwsem); |
| 1741 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1742 | return rcvd; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1743 | } |
| 1744 | |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1745 | static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1746 | char *fp, int count) |
| 1747 | { |
| 1748 | n_tty_receive_buf_common(tty, cp, fp, count, 0); |
| 1749 | } |
| 1750 | |
| 1751 | static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp, |
| 1752 | char *fp, int count) |
| 1753 | { |
| 1754 | return n_tty_receive_buf_common(tty, cp, fp, count, 1); |
| 1755 | } |
| 1756 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1757 | /** |
| 1758 | * n_tty_set_termios - termios data changed |
| 1759 | * @tty: terminal |
| 1760 | * @old: previous data |
| 1761 | * |
| 1762 | * Called by the tty layer when the user changes termios flags so |
| 1763 | * that the line discipline can plan ahead. This function cannot sleep |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1764 | * 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] | 1765 | * guaranteed that this function will not be re-entered or in progress |
| 1766 | * when the ldisc is closed. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1767 | * |
Peter Hurley | 6a1c068 | 2013-06-15 09:14:23 -0400 | [diff] [blame] | 1768 | * Locking: Caller holds tty->termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1769 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1770 | |
| 1771 | 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] | 1772 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1773 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1774 | |
Peter Hurley | c786f74 | 2013-09-17 12:53:35 -0400 | [diff] [blame] | 1775 | if (!old || (old->c_lflag ^ tty->termios.c_lflag) & ICANON) { |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 1776 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 1777 | ldata->line_start = ldata->read_tail; |
| 1778 | if (!L_ICANON(tty) || !read_cnt(ldata)) { |
| 1779 | ldata->canon_head = ldata->read_tail; |
| 1780 | ldata->push = 0; |
| 1781 | } else { |
| 1782 | set_bit((ldata->read_head - 1) & (N_TTY_BUF_SIZE - 1), |
| 1783 | ldata->read_flags); |
| 1784 | ldata->canon_head = ldata->read_head; |
| 1785 | ldata->push = 1; |
| 1786 | } |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1787 | ldata->commit_head = ldata->read_head; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1788 | ldata->erasing = 0; |
Peter Hurley | 6f9b028 | 2013-06-15 09:14:27 -0400 | [diff] [blame] | 1789 | ldata->lnext = 0; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1790 | } |
| 1791 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1792 | ldata->icanon = (L_ICANON(tty) != 0); |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 1793 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1794 | if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || |
| 1795 | I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || |
| 1796 | I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || |
| 1797 | I_PARMRK(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1798 | bitmap_zero(ldata->char_map, 256); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | |
| 1800 | if (I_IGNCR(tty) || I_ICRNL(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1801 | set_bit('\r', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1802 | if (I_INLCR(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1803 | set_bit('\n', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1804 | |
| 1805 | if (L_ICANON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1806 | set_bit(ERASE_CHAR(tty), ldata->char_map); |
| 1807 | set_bit(KILL_CHAR(tty), ldata->char_map); |
| 1808 | set_bit(EOF_CHAR(tty), ldata->char_map); |
| 1809 | set_bit('\n', ldata->char_map); |
| 1810 | set_bit(EOL_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1811 | if (L_IEXTEN(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1812 | set_bit(WERASE_CHAR(tty), ldata->char_map); |
| 1813 | set_bit(LNEXT_CHAR(tty), ldata->char_map); |
| 1814 | set_bit(EOL2_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1815 | if (L_ECHO(tty)) |
| 1816 | set_bit(REPRINT_CHAR(tty), |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1817 | ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1818 | } |
| 1819 | } |
| 1820 | if (I_IXON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1821 | set_bit(START_CHAR(tty), ldata->char_map); |
| 1822 | set_bit(STOP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1823 | } |
| 1824 | if (L_ISIG(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1825 | set_bit(INTR_CHAR(tty), ldata->char_map); |
| 1826 | set_bit(QUIT_CHAR(tty), ldata->char_map); |
| 1827 | set_bit(SUSP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1828 | } |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1829 | clear_bit(__DISABLED_CHAR, ldata->char_map); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1830 | ldata->raw = 0; |
| 1831 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1832 | } else { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1833 | ldata->raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1834 | if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && |
| 1835 | (I_IGNPAR(tty) || !I_INPCK(tty)) && |
| 1836 | (tty->driver->flags & TTY_DRIVER_REAL_RAW)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1837 | ldata->real_raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1838 | else |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1839 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1840 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1841 | /* |
| 1842 | * Fix tty hang when I_IXON(tty) is cleared, but the tty |
| 1843 | * been stopped by STOP_CHAR(tty) before it. |
| 1844 | */ |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1845 | if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) { |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1846 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1847 | process_echoes(tty); |
| 1848 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1849 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1850 | /* The termios change make the tty ready for I/O */ |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1851 | wake_up_interruptible(&tty->write_wait); |
| 1852 | wake_up_interruptible(&tty->read_wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | } |
| 1854 | |
| 1855 | /** |
| 1856 | * n_tty_close - close the ldisc for this tty |
| 1857 | * @tty: device |
| 1858 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1859 | * Called from the terminal layer when this line discipline is |
| 1860 | * being shut down, either because of a close or becsuse of a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | * discipline change. The function will not be called while other |
| 1862 | * ldisc methods are in progress. |
| 1863 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1864 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1865 | static void n_tty_close(struct tty_struct *tty) |
| 1866 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1867 | struct n_tty_data *ldata = tty->disc_data; |
| 1868 | |
Peter Hurley | 7990131 | 2013-03-11 16:44:23 -0400 | [diff] [blame] | 1869 | if (tty->link) |
| 1870 | n_tty_packet_mode_flush(tty); |
| 1871 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1872 | vfree(ldata); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1873 | tty->disc_data = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1874 | } |
| 1875 | |
| 1876 | /** |
| 1877 | * n_tty_open - open an ldisc |
| 1878 | * @tty: terminal to open |
| 1879 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1880 | * Called when this line discipline is being attached to the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | * terminal device. Can sleep. Called serialized so that no |
| 1882 | * other events will occur in parallel. No further open will occur |
| 1883 | * until a close. |
| 1884 | */ |
| 1885 | |
| 1886 | static int n_tty_open(struct tty_struct *tty) |
| 1887 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1888 | struct n_tty_data *ldata; |
| 1889 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1890 | /* Currently a malloc failure here can panic */ |
| 1891 | ldata = vmalloc(sizeof(*ldata)); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1892 | if (!ldata) |
| 1893 | goto err; |
| 1894 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1895 | ldata->overrun_time = jiffies; |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1896 | mutex_init(&ldata->atomic_read_lock); |
| 1897 | mutex_init(&ldata->output_lock); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1898 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1899 | tty->disc_data = ldata; |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 1900 | reset_buffer_flags(tty->disc_data); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1901 | ldata->column = 0; |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1902 | ldata->canon_column = 0; |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 1903 | ldata->minimum_to_wake = 1; |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1904 | ldata->num_overrun = 0; |
| 1905 | ldata->no_room = 0; |
| 1906 | ldata->lnext = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1907 | tty->closing = 0; |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 1908 | /* indicate buffer work may resume */ |
| 1909 | clear_bit(TTY_LDISC_HALTED, &tty->flags); |
| 1910 | n_tty_set_termios(tty, NULL); |
| 1911 | tty_unthrottle(tty); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1912 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1913 | return 0; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1914 | err: |
Jiri Slaby | b91939f | 2012-10-18 22:26:35 +0200 | [diff] [blame] | 1915 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1916 | } |
| 1917 | |
Peter Hurley | eafbe67 | 2013-12-02 14:24:45 -0500 | [diff] [blame] | 1918 | static inline int input_available_p(struct tty_struct *tty, int poll) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1919 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1920 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a593480 | 2014-02-11 11:49:58 -0500 | [diff] [blame] | 1921 | 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] | 1922 | |
Peter Hurley | 25e8d0e | 2014-02-11 18:55:30 -0500 | [diff] [blame] | 1923 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1924 | return ldata->canon_head != ldata->read_tail; |
| 1925 | else |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1926 | return ldata->commit_head - ldata->read_tail >= amt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1927 | } |
| 1928 | |
Peter Hurley | 1a48632 | 2015-04-13 13:24:34 -0400 | [diff] [blame] | 1929 | static inline int check_other_done(struct tty_struct *tty) |
| 1930 | { |
| 1931 | int done = test_bit(TTY_OTHER_DONE, &tty->flags); |
| 1932 | if (done) { |
| 1933 | /* paired with cmpxchg() in check_other_closed(); ensures |
| 1934 | * read buffer head index is not stale |
| 1935 | */ |
| 1936 | smp_mb__after_atomic(); |
| 1937 | } |
| 1938 | return done; |
| 1939 | } |
| 1940 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1941 | /** |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 1942 | * copy_from_read_buf - copy read data directly |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | * @tty: terminal device |
| 1944 | * @b: user data |
| 1945 | * @nr: size of data |
| 1946 | * |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1947 | * 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] | 1948 | * ICANON is off; it copies characters straight from the tty queue to |
| 1949 | * user space directly. It can be profitably called twice; once to |
| 1950 | * drain the space from the tail pointer to the (physical) end of the |
| 1951 | * buffer, and once to drain the space from the (physical) beginning of |
| 1952 | * the buffer to head pointer. |
| 1953 | * |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1954 | * Called under the ldata->atomic_read_lock sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1955 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1956 | * n_tty_read()/consumer path: |
| 1957 | * caller holds non-exclusive termios_rwsem |
| 1958 | * read_tail published |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1960 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1961 | static int copy_from_read_buf(struct tty_struct *tty, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1962 | unsigned char __user **b, |
| 1963 | size_t *nr) |
| 1964 | |
| 1965 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1966 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1967 | int retval; |
| 1968 | size_t n; |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 1969 | bool is_eof; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1970 | size_t head = smp_load_acquire(&ldata->commit_head); |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1971 | size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1972 | |
| 1973 | retval = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1974 | n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1975 | n = min(*nr, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1976 | if (n) { |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1977 | const unsigned char *from = read_buf_addr(ldata, tail); |
| 1978 | retval = copy_to_user(*b, from, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1979 | n -= retval; |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1980 | is_eof = n == 1 && *from == EOF_CHAR(tty); |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 1981 | tty_audit_add_data(tty, from, n); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1982 | smp_store_release(&ldata->read_tail, ldata->read_tail + n); |
hyc@symas.com | 26df6d1 | 2010-06-22 10:14:49 -0700 | [diff] [blame] | 1983 | /* Turn single EOF into zero-length read */ |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1984 | if (L_EXTPROC(tty) && ldata->icanon && is_eof && |
| 1985 | (head == ldata->read_tail)) |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 1986 | n = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1987 | *b += n; |
| 1988 | *nr -= n; |
| 1989 | } |
| 1990 | return retval; |
| 1991 | } |
| 1992 | |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1993 | /** |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 1994 | * canon_copy_from_read_buf - copy read data in canonical mode |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 1995 | * @tty: terminal device |
| 1996 | * @b: user data |
| 1997 | * @nr: size of data |
| 1998 | * |
| 1999 | * 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] | 2000 | * it copies one line of input up to and including the line-delimiting |
| 2001 | * character into the user-space buffer. |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2002 | * |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 2003 | * NB: When termios is changed from non-canonical to canonical mode and |
| 2004 | * the read buffer contains data, n_tty_set_termios() simulates an EOF |
| 2005 | * push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer. |
| 2006 | * This causes data already processed as input to be immediately available |
| 2007 | * as input although a newline has not been received. |
| 2008 | * |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2009 | * Called under the atomic_read_lock mutex |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2010 | * |
| 2011 | * n_tty_read()/consumer path: |
| 2012 | * caller holds non-exclusive termios_rwsem |
| 2013 | * read_tail published |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2014 | */ |
| 2015 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2016 | static int canon_copy_from_read_buf(struct tty_struct *tty, |
| 2017 | unsigned char __user **b, |
| 2018 | size_t *nr) |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2019 | { |
| 2020 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2021 | size_t n, size, more, c; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2022 | size_t eol; |
| 2023 | size_t tail; |
| 2024 | int ret, found = 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2025 | |
| 2026 | /* N.B. avoid overrun if nr == 0 */ |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2027 | if (!*nr) |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2028 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2029 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2030 | n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail); |
| 2031 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2032 | tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2033 | size = min_t(size_t, tail + n, N_TTY_BUF_SIZE); |
| 2034 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2035 | 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] | 2036 | __func__, *nr, tail, n, size); |
| 2037 | |
| 2038 | eol = find_next_bit(ldata->read_flags, size, tail); |
| 2039 | more = n - (size - tail); |
| 2040 | if (eol == N_TTY_BUF_SIZE && more) { |
| 2041 | /* scan wrapped without finding set bit */ |
| 2042 | eol = find_next_bit(ldata->read_flags, more, 0); |
Peter Hurley | b985e9e | 2015-11-27 14:11:04 -0500 | [diff] [blame] | 2043 | found = eol != more; |
| 2044 | } else |
| 2045 | found = eol != size; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2046 | |
Peter Hurley | c77569d | 2013-11-22 07:16:25 -0500 | [diff] [blame] | 2047 | n = eol - tail; |
Mark Tomlinson | da555db | 2015-05-18 12:01:48 +1200 | [diff] [blame] | 2048 | if (n > N_TTY_BUF_SIZE) |
| 2049 | n += N_TTY_BUF_SIZE; |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2050 | c = n + found; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2051 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2052 | if (!found || read_buf(ldata, eol) != __DISABLED_CHAR) { |
| 2053 | c = min(*nr, c); |
| 2054 | n = c; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2055 | } |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2056 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2057 | n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n", |
| 2058 | __func__, eol, found, n, c, tail, more); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2059 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2060 | ret = tty_copy_to_user(tty, *b, tail, n); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2061 | if (ret) |
| 2062 | return -EFAULT; |
| 2063 | *b += n; |
| 2064 | *nr -= n; |
| 2065 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2066 | if (found) |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2067 | clear_bit(eol, ldata->read_flags); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 2068 | smp_store_release(&ldata->read_tail, ldata->read_tail + c); |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2069 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2070 | if (found) { |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 2071 | if (!ldata->push) |
| 2072 | ldata->line_start = ldata->read_tail; |
| 2073 | else |
| 2074 | ldata->push = 0; |
Peter Hurley | b50819f | 2016-01-09 22:55:30 -0800 | [diff] [blame^] | 2075 | tty_audit_push(); |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2076 | } |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2077 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2078 | } |
| 2079 | |
Al Viro | cc4191d | 2008-03-29 03:08:48 +0000 | [diff] [blame] | 2080 | extern ssize_t redirected_tty_write(struct file *, const char __user *, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2081 | size_t, loff_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2082 | |
| 2083 | /** |
| 2084 | * job_control - check job control |
| 2085 | * @tty: tty |
| 2086 | * @file: file handle |
| 2087 | * |
| 2088 | * Perform job control management checks on this file/tty descriptor |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2089 | * and if appropriate send any needed signals and return a negative |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2090 | * error code if action should be taken. |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2091 | * |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2092 | * Locking: redirected write test is safe |
| 2093 | * current->signal->tty check is safe |
| 2094 | * ctrl_lock to safely reference tty->pgrp |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2095 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2096 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2097 | static int job_control(struct tty_struct *tty, struct file *file) |
| 2098 | { |
| 2099 | /* Job control check -- must be done at start and after |
| 2100 | every sleep (POSIX.1 7.1.1.4). */ |
| 2101 | /* NOTE: not yet done after every sleep pending a thorough |
| 2102 | check of the logic of this change. -- jlc */ |
| 2103 | /* don't stop on /dev/console */ |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2104 | if (file->f_op->write == redirected_tty_write) |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2105 | return 0; |
| 2106 | |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2107 | return __tty_check_change(tty, SIGTTIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2108 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2109 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2110 | |
| 2111 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2112 | * n_tty_read - read function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | * @tty: tty device |
| 2114 | * @file: file object |
| 2115 | * @buf: userspace buffer pointer |
| 2116 | * @nr: size of I/O |
| 2117 | * |
| 2118 | * Perform reads for the line discipline. We are guaranteed that the |
| 2119 | * line discipline will not be closed under us but we may get multiple |
| 2120 | * parallel readers and must handle this ourselves. We may also get |
| 2121 | * a hangup. Always called in user context, may sleep. |
| 2122 | * |
| 2123 | * This code must be sure never to sleep through a hangup. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2124 | * |
| 2125 | * n_tty_read()/consumer path: |
| 2126 | * claims non-exclusive termios_rwsem |
| 2127 | * publishes read_tail |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2128 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2129 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2130 | 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] | 2131 | unsigned char __user *buf, size_t nr) |
| 2132 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2133 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2134 | unsigned char __user *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2135 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Peter Hurley | 1a48632 | 2015-04-13 13:24:34 -0400 | [diff] [blame] | 2136 | int c, done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2137 | int minimum, time; |
| 2138 | ssize_t retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2139 | long timeout; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2140 | int packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2141 | size_t tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | c = job_control(tty, file); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2144 | if (c < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2145 | return c; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2146 | |
Peter Hurley | aefceaf | 2013-08-11 08:04:23 -0400 | [diff] [blame] | 2147 | /* |
| 2148 | * Internal serialization of reads. |
| 2149 | */ |
| 2150 | if (file->f_flags & O_NONBLOCK) { |
| 2151 | if (!mutex_trylock(&ldata->atomic_read_lock)) |
| 2152 | return -EAGAIN; |
| 2153 | } else { |
| 2154 | if (mutex_lock_interruptible(&ldata->atomic_read_lock)) |
| 2155 | return -ERESTARTSYS; |
| 2156 | } |
| 2157 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2158 | down_read(&tty->termios_rwsem); |
| 2159 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2160 | minimum = time = 0; |
| 2161 | timeout = MAX_SCHEDULE_TIMEOUT; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2162 | if (!ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2163 | minimum = MIN_CHAR(tty); |
| 2164 | if (minimum) { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2165 | time = (HZ / 10) * TIME_CHAR(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2166 | if (time) |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2167 | ldata->minimum_to_wake = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2168 | else if (!waitqueue_active(&tty->read_wait) || |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2169 | (ldata->minimum_to_wake > minimum)) |
| 2170 | ldata->minimum_to_wake = minimum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2171 | } else { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2172 | timeout = (HZ / 10) * TIME_CHAR(tty); |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2173 | ldata->minimum_to_wake = minimum = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2174 | } |
| 2175 | } |
| 2176 | |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2177 | packet = tty->packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2178 | tail = ldata->read_tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2179 | |
| 2180 | add_wait_queue(&tty->read_wait, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2181 | while (nr) { |
| 2182 | /* First test for status change. */ |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2183 | if (packet && tty->link->ctrl_status) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2184 | unsigned char cs; |
| 2185 | if (b != buf) |
| 2186 | break; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2187 | spin_lock_irq(&tty->link->ctrl_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2188 | cs = tty->link->ctrl_status; |
| 2189 | tty->link->ctrl_status = 0; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2190 | spin_unlock_irq(&tty->link->ctrl_lock); |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2191 | if (put_user(cs, b)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2192 | retval = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2193 | break; |
| 2194 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2195 | b++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2196 | nr--; |
| 2197 | break; |
| 2198 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2199 | |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2200 | if (((minimum - (b - buf)) < ldata->minimum_to_wake) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2201 | ((minimum - (b - buf)) >= 1)) |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2202 | ldata->minimum_to_wake = (minimum - (b - buf)); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2203 | |
Peter Hurley | 1a48632 | 2015-04-13 13:24:34 -0400 | [diff] [blame] | 2204 | done = check_other_done(tty); |
| 2205 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2206 | if (!input_available_p(tty, 0)) { |
Peter Hurley | 1a48632 | 2015-04-13 13:24:34 -0400 | [diff] [blame] | 2207 | if (done) { |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2208 | retval = -EIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | break; |
| 2210 | } |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2211 | if (tty_hung_up_p(file)) |
| 2212 | break; |
| 2213 | if (!timeout) |
| 2214 | break; |
| 2215 | if (file->f_flags & O_NONBLOCK) { |
| 2216 | retval = -EAGAIN; |
| 2217 | break; |
| 2218 | } |
| 2219 | if (signal_pending(current)) { |
| 2220 | retval = -ERESTARTSYS; |
| 2221 | break; |
| 2222 | } |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2223 | up_read(&tty->termios_rwsem); |
| 2224 | |
Linus Torvalds | 37da7bb | 2014-12-14 15:23:32 -0800 | [diff] [blame] | 2225 | timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, |
| 2226 | timeout); |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2227 | |
| 2228 | down_read(&tty->termios_rwsem); |
| 2229 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2230 | } |
| 2231 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2232 | if (ldata->icanon && !L_EXTPROC(tty)) { |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2233 | retval = canon_copy_from_read_buf(tty, &b, &nr); |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2234 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | break; |
| 2236 | } else { |
| 2237 | int uncopied; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2238 | |
| 2239 | /* Deal with packet mode. */ |
| 2240 | if (packet && b == buf) { |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2241 | if (put_user(TIOCPKT_DATA, b)) { |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2242 | retval = -EFAULT; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2243 | break; |
| 2244 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2245 | b++; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2246 | nr--; |
| 2247 | } |
| 2248 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2249 | uncopied = copy_from_read_buf(tty, &b, &nr); |
| 2250 | uncopied += copy_from_read_buf(tty, &b, &nr); |
| 2251 | if (uncopied) { |
| 2252 | retval = -EFAULT; |
| 2253 | break; |
| 2254 | } |
| 2255 | } |
| 2256 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 2257 | n_tty_check_unthrottle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2258 | |
| 2259 | if (b - buf >= minimum) |
| 2260 | break; |
| 2261 | if (time) |
| 2262 | timeout = time; |
| 2263 | } |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2264 | if (tail != ldata->read_tail) |
| 2265 | n_tty_kick_worker(tty); |
Peter Hurley | 42458f4 | 2013-11-07 13:59:46 -0500 | [diff] [blame] | 2266 | up_read(&tty->termios_rwsem); |
| 2267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2268 | remove_wait_queue(&tty->read_wait, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2269 | if (!waitqueue_active(&tty->read_wait)) |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2270 | ldata->minimum_to_wake = minimum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2271 | |
Peter Hurley | aebf0453 | 2013-11-07 14:01:57 -0500 | [diff] [blame] | 2272 | mutex_unlock(&ldata->atomic_read_lock); |
| 2273 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2274 | if (b - buf) |
| 2275 | retval = b - buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2276 | |
| 2277 | return retval; |
| 2278 | } |
| 2279 | |
| 2280 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2281 | * n_tty_write - write function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2282 | * @tty: tty device |
| 2283 | * @file: file object |
| 2284 | * @buf: userspace buffer pointer |
| 2285 | * @nr: size of I/O |
| 2286 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2287 | * Write function of the terminal device. This is serialized with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2288 | * respect to other write callers but not to termios changes, reads |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2289 | * and other such events. Since the receive code will echo characters, |
| 2290 | * thus calling driver write methods, the output_lock is used in |
| 2291 | * the output processing functions called here as well as in the |
| 2292 | * echo processing function to protect the column state and space |
| 2293 | * left in the buffer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2294 | * |
| 2295 | * This code must be sure never to sleep through a hangup. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2296 | * |
| 2297 | * Locking: output_lock to protect column state and space left |
| 2298 | * (note that the process_output*() functions take this |
| 2299 | * lock themselves) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2300 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2301 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2302 | 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] | 2303 | const unsigned char *buf, size_t nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2304 | { |
| 2305 | const unsigned char *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2306 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2307 | int c; |
| 2308 | ssize_t retval = 0; |
| 2309 | |
| 2310 | /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */ |
| 2311 | if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) { |
| 2312 | retval = tty_check_change(tty); |
| 2313 | if (retval) |
| 2314 | return retval; |
| 2315 | } |
| 2316 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2317 | down_read(&tty->termios_rwsem); |
| 2318 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2319 | /* Write out any echoed characters that are still pending */ |
| 2320 | process_echoes(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 2321 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2322 | add_wait_queue(&tty->write_wait, &wait); |
| 2323 | while (1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2324 | if (signal_pending(current)) { |
| 2325 | retval = -ERESTARTSYS; |
| 2326 | break; |
| 2327 | } |
| 2328 | if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) { |
| 2329 | retval = -EIO; |
| 2330 | break; |
| 2331 | } |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 2332 | if (O_OPOST(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2333 | while (nr > 0) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2334 | ssize_t num = process_output_block(tty, b, nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | if (num < 0) { |
| 2336 | if (num == -EAGAIN) |
| 2337 | break; |
| 2338 | retval = num; |
| 2339 | goto break_out; |
| 2340 | } |
| 2341 | b += num; |
| 2342 | nr -= num; |
| 2343 | if (nr == 0) |
| 2344 | break; |
| 2345 | c = *b; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2346 | if (process_output(c, tty) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2347 | break; |
| 2348 | b++; nr--; |
| 2349 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2350 | if (tty->ops->flush_chars) |
| 2351 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2352 | } else { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2353 | struct n_tty_data *ldata = tty->disc_data; |
| 2354 | |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2355 | while (nr > 0) { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2356 | mutex_lock(&ldata->output_lock); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2357 | c = tty->ops->write(tty, b, nr); |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2358 | mutex_unlock(&ldata->output_lock); |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2359 | if (c < 0) { |
| 2360 | retval = c; |
| 2361 | goto break_out; |
| 2362 | } |
| 2363 | if (!c) |
| 2364 | break; |
| 2365 | b += c; |
| 2366 | nr -= c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2367 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2368 | } |
| 2369 | if (!nr) |
| 2370 | break; |
| 2371 | if (file->f_flags & O_NONBLOCK) { |
| 2372 | retval = -EAGAIN; |
| 2373 | break; |
| 2374 | } |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2375 | up_read(&tty->termios_rwsem); |
| 2376 | |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2377 | wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2378 | |
| 2379 | down_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2380 | } |
| 2381 | break_out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2382 | remove_wait_queue(&tty->write_wait, &wait); |
Thomas Pfaff | ff8cb0f | 2009-01-02 13:47:13 +0000 | [diff] [blame] | 2383 | if (b - buf != nr && tty->fasync) |
| 2384 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2385 | up_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2386 | return (b - buf) ? b - buf : retval; |
| 2387 | } |
| 2388 | |
| 2389 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2390 | * n_tty_poll - poll method for N_TTY |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2391 | * @tty: terminal device |
| 2392 | * @file: file accessing it |
| 2393 | * @wait: poll table |
| 2394 | * |
| 2395 | * Called when the line discipline is asked to poll() for data or |
| 2396 | * for special events. This code is not serialized with respect to |
| 2397 | * other events save open/close. |
| 2398 | * |
| 2399 | * This code must be sure never to sleep through a hangup. |
| 2400 | * Called without the kernel lock held - fine |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2401 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2402 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2403 | static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2404 | poll_table *wait) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2405 | { |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2406 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2407 | unsigned int mask = 0; |
| 2408 | |
| 2409 | poll_wait(file, &tty->read_wait, wait); |
| 2410 | poll_wait(file, &tty->write_wait, wait); |
Peter Hurley | 1a48632 | 2015-04-13 13:24:34 -0400 | [diff] [blame] | 2411 | if (check_other_done(tty)) |
| 2412 | mask |= POLLHUP; |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2413 | if (input_available_p(tty, 1)) |
| 2414 | mask |= POLLIN | POLLRDNORM; |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2415 | if (tty->packet && tty->link->ctrl_status) |
| 2416 | mask |= POLLPRI | POLLIN | POLLRDNORM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2417 | if (tty_hung_up_p(file)) |
| 2418 | mask |= POLLHUP; |
| 2419 | if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) { |
| 2420 | if (MIN_CHAR(tty) && !TIME_CHAR(tty)) |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2421 | ldata->minimum_to_wake = MIN_CHAR(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2422 | else |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2423 | ldata->minimum_to_wake = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2424 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2425 | if (tty->ops->write && !tty_is_writelocked(tty) && |
| 2426 | tty_chars_in_buffer(tty) < WAKEUP_CHARS && |
| 2427 | tty_write_room(tty) > 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2428 | mask |= POLLOUT | POLLWRNORM; |
| 2429 | return mask; |
| 2430 | } |
| 2431 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2432 | static unsigned long inq_canon(struct n_tty_data *ldata) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2433 | { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2434 | size_t nr, head, tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2435 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2436 | if (ldata->canon_head == ldata->read_tail) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2437 | return 0; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2438 | head = ldata->canon_head; |
| 2439 | tail = ldata->read_tail; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2440 | nr = head - tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2441 | /* Skip EOF-chars.. */ |
| 2442 | while (head != tail) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2443 | if (test_bit(tail & (N_TTY_BUF_SIZE - 1), ldata->read_flags) && |
| 2444 | read_buf(ldata, tail) == __DISABLED_CHAR) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2445 | nr--; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2446 | tail++; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2447 | } |
| 2448 | return nr; |
| 2449 | } |
| 2450 | |
| 2451 | static int n_tty_ioctl(struct tty_struct *tty, struct file *file, |
| 2452 | unsigned int cmd, unsigned long arg) |
| 2453 | { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2454 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2455 | int retval; |
| 2456 | |
| 2457 | switch (cmd) { |
| 2458 | case TIOCOUTQ: |
| 2459 | return put_user(tty_chars_in_buffer(tty), (int __user *) arg); |
| 2460 | case TIOCINQ: |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2461 | down_write(&tty->termios_rwsem); |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2462 | if (L_ICANON(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2463 | retval = inq_canon(ldata); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2464 | else |
| 2465 | retval = read_cnt(ldata); |
| 2466 | up_write(&tty->termios_rwsem); |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2467 | return put_user(retval, (unsigned int __user *) arg); |
| 2468 | default: |
| 2469 | return n_tty_ioctl_helper(tty, file, cmd, arg); |
| 2470 | } |
| 2471 | } |
| 2472 | |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2473 | static void n_tty_fasync(struct tty_struct *tty, int on) |
| 2474 | { |
| 2475 | struct n_tty_data *ldata = tty->disc_data; |
| 2476 | |
| 2477 | if (!waitqueue_active(&tty->read_wait)) { |
| 2478 | if (on) |
| 2479 | ldata->minimum_to_wake = 1; |
| 2480 | else if (!tty->fasync) |
| 2481 | ldata->minimum_to_wake = N_TTY_BUF_SIZE; |
| 2482 | } |
| 2483 | } |
| 2484 | |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2485 | static struct tty_ldisc_ops n_tty_ops = { |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2486 | .magic = TTY_LDISC_MAGIC, |
| 2487 | .name = "n_tty", |
| 2488 | .open = n_tty_open, |
| 2489 | .close = n_tty_close, |
| 2490 | .flush_buffer = n_tty_flush_buffer, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2491 | .read = n_tty_read, |
| 2492 | .write = n_tty_write, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2493 | .ioctl = n_tty_ioctl, |
| 2494 | .set_termios = n_tty_set_termios, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2495 | .poll = n_tty_poll, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2496 | .receive_buf = n_tty_receive_buf, |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2497 | .write_wakeup = n_tty_write_wakeup, |
| 2498 | .fasync = n_tty_fasync, |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 2499 | .receive_buf2 = n_tty_receive_buf2, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2500 | }; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2501 | |
| 2502 | /** |
| 2503 | * n_tty_inherit_ops - inherit N_TTY methods |
| 2504 | * @ops: struct tty_ldisc_ops where to save N_TTY methods |
| 2505 | * |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2506 | * Enables a 'subclass' line discipline to 'inherit' N_TTY methods. |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2507 | */ |
| 2508 | |
| 2509 | void n_tty_inherit_ops(struct tty_ldisc_ops *ops) |
| 2510 | { |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2511 | *ops = n_tty_ops; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2512 | ops->owner = NULL; |
| 2513 | ops->refcount = ops->flags = 0; |
| 2514 | } |
| 2515 | EXPORT_SYMBOL_GPL(n_tty_inherit_ops); |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2516 | |
| 2517 | void __init n_tty_init(void) |
| 2518 | { |
| 2519 | tty_register_ldisc(N_TTY, &n_tty_ops); |
| 2520 | } |