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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
| 51 | #include <asm/uaccess.h> |
| 52 | #include <asm/system.h> |
| 53 | |
| 54 | /* number of characters left in xmit buffer before select has we have room */ |
| 55 | #define WAKEUP_CHARS 256 |
| 56 | |
| 57 | /* |
| 58 | * This defines the low- and high-watermarks for throttling and |
| 59 | * unthrottling the TTY driver. These watermarks are used for |
| 60 | * controlling the space in the read buffer. |
| 61 | */ |
| 62 | #define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */ |
| 63 | #define TTY_THRESHOLD_UNTHROTTLE 128 |
| 64 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 65 | /* |
| 66 | * Special byte codes used in the echo buffer to represent operations |
| 67 | * or special handling of characters. Bytes in the echo buffer that |
| 68 | * are not part of such special blocks are treated as normal character |
| 69 | * codes. |
| 70 | */ |
| 71 | #define ECHO_OP_START 0xff |
| 72 | #define ECHO_OP_MOVE_BACK_COL 0x80 |
| 73 | #define ECHO_OP_SET_CANON_COL 0x81 |
| 74 | #define ECHO_OP_ERASE_TAB 0x82 |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | static inline unsigned char *alloc_buf(void) |
| 77 | { |
Al Viro | b4e3ca1 | 2005-10-21 03:22:34 -0400 | [diff] [blame] | 78 | gfp_t prio = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | if (PAGE_SIZE != N_TTY_BUF_SIZE) |
| 81 | return kmalloc(N_TTY_BUF_SIZE, prio); |
| 82 | else |
| 83 | return (unsigned char *)__get_free_page(prio); |
| 84 | } |
| 85 | |
| 86 | static inline void free_buf(unsigned char *buf) |
| 87 | { |
| 88 | if (PAGE_SIZE != N_TTY_BUF_SIZE) |
| 89 | kfree(buf); |
| 90 | else |
| 91 | free_page((unsigned long) buf); |
| 92 | } |
| 93 | |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 94 | static inline int tty_put_user(struct tty_struct *tty, unsigned char x, |
| 95 | unsigned char __user *ptr) |
| 96 | { |
| 97 | tty_audit_add_data(tty, &x, 1); |
| 98 | return put_user(x, ptr); |
| 99 | } |
| 100 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 101 | /** |
| 102 | * n_tty_set__room - receive space |
| 103 | * @tty: terminal |
| 104 | * |
| 105 | * Called by the driver to find out how much data it is |
| 106 | * permitted to feed to the line discipline without any being lost |
| 107 | * and thus to manage flow control. Not serialized. Answers for the |
| 108 | * "instant". |
| 109 | */ |
| 110 | |
| 111 | static void n_tty_set_room(struct tty_struct *tty) |
| 112 | { |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 113 | /* tty->read_cnt is not read locked ? */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 114 | int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; |
| 115 | |
| 116 | /* |
| 117 | * If we are doing input canonicalization, and there are no |
| 118 | * pending newlines, let characters through without limit, so |
| 119 | * that erase characters will be handled. Other excess |
| 120 | * characters will be beeped. |
| 121 | */ |
| 122 | if (left <= 0) |
| 123 | left = tty->icanon && !tty->canon_data; |
| 124 | tty->receive_room = left; |
| 125 | } |
| 126 | |
| 127 | static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | { |
| 129 | if (tty->read_cnt < N_TTY_BUF_SIZE) { |
| 130 | tty->read_buf[tty->read_head] = c; |
| 131 | tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1); |
| 132 | tty->read_cnt++; |
| 133 | } |
| 134 | } |
| 135 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 136 | /** |
| 137 | * put_tty_queue - add character to tty |
| 138 | * @c: character |
| 139 | * @tty: tty device |
| 140 | * |
| 141 | * Add a character to the tty read_buf queue. This is done under the |
| 142 | * read_lock to serialize character addition and also to protect us |
| 143 | * against parallel reads or flushes |
| 144 | */ |
| 145 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 146 | static void put_tty_queue(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | { |
| 148 | unsigned long flags; |
| 149 | /* |
| 150 | * The problem of stomping on the buffers ends here. |
| 151 | * Why didn't anyone see this one coming? --AJK |
| 152 | */ |
| 153 | spin_lock_irqsave(&tty->read_lock, flags); |
| 154 | put_tty_queue_nolock(c, tty); |
| 155 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * check_unthrottle - allow new receive data |
| 160 | * @tty; tty device |
| 161 | * |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 162 | * Check whether to call the driver unthrottle functions |
| 163 | * |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 164 | * Can sleep, may be called under the atomic_read_lock mutex but |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | * this is not guaranteed. |
| 166 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 167 | static void check_unthrottle(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | { |
Alan Cox | 39c2e60 | 2008-04-30 00:54:18 -0700 | [diff] [blame] | 169 | if (tty->count) |
| 170 | tty_unthrottle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | } |
| 172 | |
| 173 | /** |
| 174 | * reset_buffer_flags - reset buffer state |
| 175 | * @tty: terminal to reset |
| 176 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 177 | * Reset the read buffer counters, clear the flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | * and make sure the driver is unthrottled. Called |
| 179 | * from n_tty_open() and n_tty_flush_buffer(). |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 180 | * |
| 181 | * Locking: tty_read_lock for read fields. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 183 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | static void reset_buffer_flags(struct tty_struct *tty) |
| 185 | { |
| 186 | unsigned long flags; |
| 187 | |
| 188 | spin_lock_irqsave(&tty->read_lock, flags); |
| 189 | tty->read_head = tty->read_tail = tty->read_cnt = 0; |
| 190 | spin_unlock_irqrestore(&tty->read_lock, flags); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 191 | |
| 192 | mutex_lock(&tty->echo_lock); |
| 193 | tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0; |
| 194 | mutex_unlock(&tty->echo_lock); |
| 195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | tty->canon_head = tty->canon_data = tty->erasing = 0; |
| 197 | memset(&tty->read_flags, 0, sizeof tty->read_flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 198 | n_tty_set_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | check_unthrottle(tty); |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * n_tty_flush_buffer - clean input queue |
| 204 | * @tty: terminal device |
| 205 | * |
| 206 | * Flush the input buffer. Called when the line discipline is |
| 207 | * being closed, when the tty layer wants the buffer flushed (eg |
| 208 | * at hangup) or when the N_TTY line discipline internally has to |
| 209 | * clean the pending queue (for example some signals). |
| 210 | * |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 211 | * Locking: ctrl_lock, read_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 213 | |
| 214 | static void n_tty_flush_buffer(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | { |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 216 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | /* clear everything and unthrottle the driver */ |
| 218 | reset_buffer_flags(tty); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 219 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | if (!tty->link) |
| 221 | return; |
| 222 | |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 223 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | if (tty->link->packet) { |
| 225 | tty->ctrl_status |= TIOCPKT_FLUSHREAD; |
| 226 | wake_up_interruptible(&tty->link->read_wait); |
| 227 | } |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 228 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | } |
| 230 | |
| 231 | /** |
| 232 | * n_tty_chars_in_buffer - report available bytes |
| 233 | * @tty: tty device |
| 234 | * |
| 235 | * Report the number of characters buffered to be delivered to user |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 236 | * at this instant in time. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 237 | * |
| 238 | * Locking: read_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 240 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) |
| 242 | { |
| 243 | unsigned long flags; |
| 244 | ssize_t n = 0; |
| 245 | |
| 246 | spin_lock_irqsave(&tty->read_lock, flags); |
| 247 | if (!tty->icanon) { |
| 248 | n = tty->read_cnt; |
| 249 | } else if (tty->canon_data) { |
| 250 | n = (tty->canon_head > tty->read_tail) ? |
| 251 | tty->canon_head - tty->read_tail : |
| 252 | tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail); |
| 253 | } |
| 254 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 255 | return n; |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * is_utf8_continuation - utf8 multibyte check |
| 260 | * @c: byte to check |
| 261 | * |
| 262 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 263 | * character. We use this to correctly compute the on screen size |
| 264 | * of the character when printing |
| 265 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 266 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | static inline int is_utf8_continuation(unsigned char c) |
| 268 | { |
| 269 | return (c & 0xc0) == 0x80; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * is_continuation - multibyte check |
| 274 | * @c: byte to check |
| 275 | * |
| 276 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 277 | * character and the terminal is in unicode mode. |
| 278 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | static inline int is_continuation(unsigned char c, struct tty_struct *tty) |
| 281 | { |
| 282 | return I_IUTF8(tty) && is_utf8_continuation(c); |
| 283 | } |
| 284 | |
| 285 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 286 | * do_output_char - output one character |
| 287 | * @c: character (or partial unicode symbol) |
| 288 | * @tty: terminal device |
| 289 | * @space: space available in tty driver write buffer |
| 290 | * |
| 291 | * This is a helper function that handles one output character |
| 292 | * (including special characters like TAB, CR, LF, etc.), |
| 293 | * putting the results in the tty driver's write buffer. |
| 294 | * |
| 295 | * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY |
| 296 | * and NLDLY. They simply aren't relevant in the world today. |
| 297 | * If you ever need them, add them here. |
| 298 | * |
| 299 | * Returns the number of bytes of buffer space used or -1 if |
| 300 | * no space left. |
| 301 | * |
| 302 | * Locking: should be called under the output_lock to protect |
| 303 | * the column state and space left in the buffer |
| 304 | */ |
| 305 | |
| 306 | static int do_output_char(unsigned char c, struct tty_struct *tty, int space) |
| 307 | { |
| 308 | int spaces; |
| 309 | |
| 310 | if (!space) |
| 311 | return -1; |
| 312 | |
| 313 | switch (c) { |
| 314 | case '\n': |
| 315 | if (O_ONLRET(tty)) |
| 316 | tty->column = 0; |
| 317 | if (O_ONLCR(tty)) { |
| 318 | if (space < 2) |
| 319 | return -1; |
| 320 | tty->canon_column = tty->column = 0; |
| 321 | tty_put_char(tty, '\r'); |
| 322 | tty_put_char(tty, c); |
| 323 | return 2; |
| 324 | } |
| 325 | tty->canon_column = tty->column; |
| 326 | break; |
| 327 | case '\r': |
| 328 | if (O_ONOCR(tty) && tty->column == 0) |
| 329 | return 0; |
| 330 | if (O_OCRNL(tty)) { |
| 331 | c = '\n'; |
| 332 | if (O_ONLRET(tty)) |
| 333 | tty->canon_column = tty->column = 0; |
| 334 | break; |
| 335 | } |
| 336 | tty->canon_column = tty->column = 0; |
| 337 | break; |
| 338 | case '\t': |
| 339 | spaces = 8 - (tty->column & 7); |
| 340 | if (O_TABDLY(tty) == XTABS) { |
| 341 | if (space < spaces) |
| 342 | return -1; |
| 343 | tty->column += spaces; |
| 344 | tty->ops->write(tty, " ", spaces); |
| 345 | return spaces; |
| 346 | } |
| 347 | tty->column += spaces; |
| 348 | break; |
| 349 | case '\b': |
| 350 | if (tty->column > 0) |
| 351 | tty->column--; |
| 352 | break; |
| 353 | default: |
| 354 | if (O_OLCUC(tty)) |
| 355 | c = toupper(c); |
| 356 | if (!iscntrl(c) && !is_continuation(c, tty)) |
| 357 | tty->column++; |
| 358 | break; |
| 359 | } |
| 360 | |
| 361 | tty_put_char(tty, c); |
| 362 | return 1; |
| 363 | } |
| 364 | |
| 365 | /** |
| 366 | * process_output - output post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | * @c: character (or partial unicode symbol) |
| 368 | * @tty: terminal device |
| 369 | * |
| 370 | * Perform OPOST processing. Returns -1 when the output device is |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 371 | * full and the character must be retried. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 373 | * Locking: output_lock to protect column state and space left |
| 374 | * (also, this is called from n_tty_write under the |
| 375 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 377 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 378 | static int process_output(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 380 | int space, retval; |
| 381 | |
| 382 | mutex_lock(&tty->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 384 | space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 385 | retval = do_output_char(c, tty, space); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 387 | mutex_unlock(&tty->output_lock); |
| 388 | if (retval < 0) |
| 389 | return -1; |
| 390 | else |
| 391 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | } |
| 393 | |
| 394 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 395 | * process_output_block - block post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | * @tty: terminal device |
| 397 | * @inbuf: user buffer |
| 398 | * @nr: number of bytes |
| 399 | * |
| 400 | * This path is used to speed up block console writes, among other |
| 401 | * things when processing blocks of output data. It handles only |
| 402 | * the simple cases normally found and helps to generate blocks of |
| 403 | * symbols for the console driver and thus improve performance. |
| 404 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 405 | * Locking: output_lock to protect column state and space left |
| 406 | * (also, this is called from n_tty_write under the |
| 407 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 409 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 410 | static ssize_t process_output_block(struct tty_struct *tty, |
| 411 | const unsigned char *buf, unsigned int nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | { |
| 413 | int space; |
| 414 | int i; |
| 415 | const unsigned char *cp; |
| 416 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 417 | mutex_lock(&tty->output_lock); |
| 418 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 419 | space = tty_write_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | if (!space) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 421 | { |
| 422 | mutex_unlock(&tty->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | return 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 424 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | if (nr > space) |
| 426 | nr = space; |
| 427 | |
| 428 | for (i = 0, cp = buf; i < nr; i++, cp++) { |
| 429 | switch (*cp) { |
| 430 | case '\n': |
| 431 | if (O_ONLRET(tty)) |
| 432 | tty->column = 0; |
| 433 | if (O_ONLCR(tty)) |
| 434 | goto break_out; |
| 435 | tty->canon_column = tty->column; |
| 436 | break; |
| 437 | case '\r': |
| 438 | if (O_ONOCR(tty) && tty->column == 0) |
| 439 | goto break_out; |
| 440 | if (O_OCRNL(tty)) |
| 441 | goto break_out; |
| 442 | tty->canon_column = tty->column = 0; |
| 443 | break; |
| 444 | case '\t': |
| 445 | goto break_out; |
| 446 | case '\b': |
| 447 | if (tty->column > 0) |
| 448 | tty->column--; |
| 449 | break; |
| 450 | default: |
| 451 | if (O_OLCUC(tty)) |
| 452 | goto break_out; |
| 453 | if (!iscntrl(*cp)) |
| 454 | tty->column++; |
| 455 | break; |
| 456 | } |
| 457 | } |
| 458 | break_out: |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 459 | i = tty->ops->write(tty, buf, i); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 460 | |
| 461 | mutex_unlock(&tty->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | return i; |
| 463 | } |
| 464 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 465 | /** |
| 466 | * process_echoes - write pending echo characters |
| 467 | * @tty: terminal device |
| 468 | * |
| 469 | * Write previously buffered echo (and other ldisc-generated) |
| 470 | * characters to the tty. |
| 471 | * |
| 472 | * Characters generated by the ldisc (including echoes) need to |
| 473 | * be buffered because the driver's write buffer can fill during |
| 474 | * heavy program output. Echoing straight to the driver will |
| 475 | * often fail under these conditions, causing lost characters and |
| 476 | * resulting mismatches of ldisc state information. |
| 477 | * |
| 478 | * Since the ldisc state must represent the characters actually sent |
| 479 | * to the driver at the time of the write, operations like certain |
| 480 | * changes in column state are also saved in the buffer and executed |
| 481 | * here. |
| 482 | * |
| 483 | * A circular fifo buffer is used so that the most recent characters |
| 484 | * are prioritized. Also, when control characters are echoed with a |
| 485 | * prefixed "^", the pair is treated atomically and thus not separated. |
| 486 | * |
| 487 | * Locking: output_lock to protect column state and space left, |
| 488 | * echo_lock to protect the echo buffer |
| 489 | */ |
| 490 | |
| 491 | static void process_echoes(struct tty_struct *tty) |
| 492 | { |
| 493 | int space, nr; |
| 494 | unsigned char c; |
| 495 | unsigned char *cp, *buf_end; |
| 496 | |
| 497 | if (!tty->echo_cnt) |
| 498 | return; |
| 499 | |
| 500 | mutex_lock(&tty->output_lock); |
| 501 | mutex_lock(&tty->echo_lock); |
| 502 | |
| 503 | space = tty_write_room(tty); |
| 504 | |
| 505 | buf_end = tty->echo_buf + N_TTY_BUF_SIZE; |
| 506 | cp = tty->echo_buf + tty->echo_pos; |
| 507 | nr = tty->echo_cnt; |
| 508 | while (nr > 0) { |
| 509 | c = *cp; |
| 510 | if (c == ECHO_OP_START) { |
| 511 | unsigned char op; |
| 512 | unsigned char *opp; |
| 513 | int no_space_left = 0; |
| 514 | |
| 515 | /* |
| 516 | * If the buffer byte is the start of a multi-byte |
| 517 | * operation, get the next byte, which is either the |
| 518 | * op code or a control character value. |
| 519 | */ |
| 520 | opp = cp + 1; |
| 521 | if (opp == buf_end) |
| 522 | opp -= N_TTY_BUF_SIZE; |
| 523 | op = *opp; |
| 524 | |
| 525 | switch (op) { |
| 526 | unsigned int num_chars, num_bs; |
| 527 | |
| 528 | case ECHO_OP_ERASE_TAB: |
| 529 | if (++opp == buf_end) |
| 530 | opp -= N_TTY_BUF_SIZE; |
| 531 | num_chars = *opp; |
| 532 | |
| 533 | /* |
| 534 | * Determine how many columns to go back |
| 535 | * in order to erase the tab. |
| 536 | * This depends on the number of columns |
| 537 | * used by other characters within the tab |
| 538 | * area. If this (modulo 8) count is from |
| 539 | * the start of input rather than from a |
| 540 | * previous tab, we offset by canon column. |
| 541 | * Otherwise, tab spacing is normal. |
| 542 | */ |
| 543 | if (!(num_chars & 0x80)) |
| 544 | num_chars += tty->canon_column; |
| 545 | num_bs = 8 - (num_chars & 7); |
| 546 | |
| 547 | if (num_bs > space) { |
| 548 | no_space_left = 1; |
| 549 | break; |
| 550 | } |
| 551 | space -= num_bs; |
| 552 | while (num_bs--) { |
| 553 | tty_put_char(tty, '\b'); |
| 554 | if (tty->column > 0) |
| 555 | tty->column--; |
| 556 | } |
| 557 | cp += 3; |
| 558 | nr -= 3; |
| 559 | break; |
| 560 | |
| 561 | case ECHO_OP_SET_CANON_COL: |
| 562 | tty->canon_column = tty->column; |
| 563 | cp += 2; |
| 564 | nr -= 2; |
| 565 | break; |
| 566 | |
| 567 | case ECHO_OP_MOVE_BACK_COL: |
| 568 | if (tty->column > 0) |
| 569 | tty->column--; |
| 570 | cp += 2; |
| 571 | nr -= 2; |
| 572 | break; |
| 573 | |
| 574 | case ECHO_OP_START: |
| 575 | /* This is an escaped echo op start code */ |
| 576 | if (!space) { |
| 577 | no_space_left = 1; |
| 578 | break; |
| 579 | } |
| 580 | tty_put_char(tty, ECHO_OP_START); |
| 581 | tty->column++; |
| 582 | space--; |
| 583 | cp += 2; |
| 584 | nr -= 2; |
| 585 | break; |
| 586 | |
| 587 | default: |
| 588 | if (iscntrl(op)) { |
| 589 | if (L_ECHOCTL(tty)) { |
| 590 | /* |
| 591 | * Ensure there is enough space |
| 592 | * for the whole ctrl pair. |
| 593 | */ |
| 594 | if (space < 2) { |
| 595 | no_space_left = 1; |
| 596 | break; |
| 597 | } |
| 598 | tty_put_char(tty, '^'); |
| 599 | tty_put_char(tty, op ^ 0100); |
| 600 | tty->column += 2; |
| 601 | space -= 2; |
| 602 | } else { |
| 603 | if (!space) { |
| 604 | no_space_left = 1; |
| 605 | break; |
| 606 | } |
| 607 | tty_put_char(tty, op); |
| 608 | space--; |
| 609 | } |
| 610 | } |
| 611 | /* |
| 612 | * If above falls through, this was an |
| 613 | * undefined op. |
| 614 | */ |
| 615 | cp += 2; |
| 616 | nr -= 2; |
| 617 | } |
| 618 | |
| 619 | if (no_space_left) |
| 620 | break; |
| 621 | } else { |
| 622 | int retval; |
| 623 | |
| 624 | if ((retval = do_output_char(c, tty, space)) < 0) |
| 625 | break; |
| 626 | space -= retval; |
| 627 | cp += 1; |
| 628 | nr -= 1; |
| 629 | } |
| 630 | |
| 631 | /* When end of circular buffer reached, wrap around */ |
| 632 | if (cp >= buf_end) |
| 633 | cp -= N_TTY_BUF_SIZE; |
| 634 | } |
| 635 | |
| 636 | if (nr == 0) { |
| 637 | tty->echo_pos = 0; |
| 638 | tty->echo_cnt = 0; |
| 639 | tty->echo_overrun = 0; |
| 640 | } else { |
| 641 | int num_processed = tty->echo_cnt - nr; |
| 642 | tty->echo_pos += num_processed; |
| 643 | tty->echo_pos &= N_TTY_BUF_SIZE - 1; |
| 644 | tty->echo_cnt = nr; |
| 645 | if (num_processed > 0) |
| 646 | tty->echo_overrun = 0; |
| 647 | } |
| 648 | |
| 649 | mutex_unlock(&tty->echo_lock); |
| 650 | mutex_unlock(&tty->output_lock); |
| 651 | |
| 652 | if (tty->ops->flush_chars) |
| 653 | tty->ops->flush_chars(tty); |
| 654 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | |
| 656 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 657 | * add_echo_byte - add a byte to the echo buffer |
| 658 | * @c: unicode byte to echo |
| 659 | * @tty: terminal device |
| 660 | * |
| 661 | * Add a character or operation byte to the echo buffer. |
| 662 | * |
| 663 | * Should be called under the echo lock to protect the echo buffer. |
| 664 | */ |
| 665 | |
| 666 | static void add_echo_byte(unsigned char c, struct tty_struct *tty) |
| 667 | { |
| 668 | int new_byte_pos; |
| 669 | |
| 670 | if (tty->echo_cnt == N_TTY_BUF_SIZE) { |
| 671 | /* Circular buffer is already at capacity */ |
| 672 | new_byte_pos = tty->echo_pos; |
| 673 | |
| 674 | /* |
| 675 | * Since the buffer start position needs to be advanced, |
| 676 | * be sure to step by a whole operation byte group. |
| 677 | */ |
| 678 | if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) |
| 679 | { |
| 680 | if (tty->echo_buf[(tty->echo_pos + 1) & |
| 681 | (N_TTY_BUF_SIZE - 1)] == |
| 682 | ECHO_OP_ERASE_TAB) { |
| 683 | tty->echo_pos += 3; |
| 684 | tty->echo_cnt -= 2; |
| 685 | } else { |
| 686 | tty->echo_pos += 2; |
| 687 | tty->echo_cnt -= 1; |
| 688 | } |
| 689 | } else { |
| 690 | tty->echo_pos++; |
| 691 | } |
| 692 | tty->echo_pos &= N_TTY_BUF_SIZE - 1; |
| 693 | |
| 694 | tty->echo_overrun = 1; |
| 695 | } else { |
| 696 | new_byte_pos = tty->echo_pos + tty->echo_cnt; |
| 697 | new_byte_pos &= N_TTY_BUF_SIZE - 1; |
| 698 | tty->echo_cnt++; |
| 699 | } |
| 700 | |
| 701 | tty->echo_buf[new_byte_pos] = c; |
| 702 | } |
| 703 | |
| 704 | /** |
| 705 | * echo_move_back_col - add operation to move back a column |
| 706 | * @tty: terminal device |
| 707 | * |
| 708 | * Add an operation to the echo buffer to move back one column. |
| 709 | * |
| 710 | * Locking: echo_lock to protect the echo buffer |
| 711 | */ |
| 712 | |
| 713 | static void echo_move_back_col(struct tty_struct *tty) |
| 714 | { |
| 715 | mutex_lock(&tty->echo_lock); |
| 716 | |
| 717 | add_echo_byte(ECHO_OP_START, tty); |
| 718 | add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty); |
| 719 | |
| 720 | mutex_unlock(&tty->echo_lock); |
| 721 | } |
| 722 | |
| 723 | /** |
| 724 | * echo_set_canon_col - add operation to set the canon column |
| 725 | * @tty: terminal device |
| 726 | * |
| 727 | * Add an operation to the echo buffer to set the canon column |
| 728 | * to the current column. |
| 729 | * |
| 730 | * Locking: echo_lock to protect the echo buffer |
| 731 | */ |
| 732 | |
| 733 | static void echo_set_canon_col(struct tty_struct *tty) |
| 734 | { |
| 735 | mutex_lock(&tty->echo_lock); |
| 736 | |
| 737 | add_echo_byte(ECHO_OP_START, tty); |
| 738 | add_echo_byte(ECHO_OP_SET_CANON_COL, tty); |
| 739 | |
| 740 | mutex_unlock(&tty->echo_lock); |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * echo_erase_tab - add operation to erase a tab |
| 745 | * @num_chars: number of character columns already used |
| 746 | * @after_tab: true if num_chars starts after a previous tab |
| 747 | * @tty: terminal device |
| 748 | * |
| 749 | * Add an operation to the echo buffer to erase a tab. |
| 750 | * |
| 751 | * Called by the eraser function, which knows how many character |
| 752 | * columns have been used since either a previous tab or the start |
| 753 | * of input. This information will be used later, along with |
| 754 | * canon column (if applicable), to go back the correct number |
| 755 | * of columns. |
| 756 | * |
| 757 | * Locking: echo_lock to protect the echo buffer |
| 758 | */ |
| 759 | |
| 760 | static void echo_erase_tab(unsigned int num_chars, int after_tab, |
| 761 | struct tty_struct *tty) |
| 762 | { |
| 763 | mutex_lock(&tty->echo_lock); |
| 764 | |
| 765 | add_echo_byte(ECHO_OP_START, tty); |
| 766 | add_echo_byte(ECHO_OP_ERASE_TAB, tty); |
| 767 | |
| 768 | /* We only need to know this modulo 8 (tab spacing) */ |
| 769 | num_chars &= 7; |
| 770 | |
| 771 | /* Set the high bit as a flag if num_chars is after a previous tab */ |
| 772 | if (after_tab) |
| 773 | num_chars |= 0x80; |
| 774 | |
| 775 | add_echo_byte(num_chars, tty); |
| 776 | |
| 777 | mutex_unlock(&tty->echo_lock); |
| 778 | } |
| 779 | |
| 780 | /** |
| 781 | * echo_char_raw - echo a character raw |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | * @c: unicode byte to echo |
| 783 | * @tty: terminal device |
| 784 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 785 | * 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] | 786 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 787 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 788 | * This variant does not treat control characters specially. |
| 789 | * |
| 790 | * Locking: echo_lock to protect the echo buffer |
| 791 | */ |
| 792 | |
| 793 | static void echo_char_raw(unsigned char c, struct tty_struct *tty) |
| 794 | { |
| 795 | mutex_lock(&tty->echo_lock); |
| 796 | |
| 797 | if (c == ECHO_OP_START) { |
| 798 | add_echo_byte(ECHO_OP_START, tty); |
| 799 | add_echo_byte(ECHO_OP_START, tty); |
| 800 | } else { |
| 801 | add_echo_byte(c, tty); |
| 802 | } |
| 803 | |
| 804 | mutex_unlock(&tty->echo_lock); |
| 805 | } |
| 806 | |
| 807 | /** |
| 808 | * echo_char - echo a character |
| 809 | * @c: unicode byte to echo |
| 810 | * @tty: terminal device |
| 811 | * |
| 812 | * Echo user input back onto the screen. This must be called only when |
| 813 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
| 814 | * |
| 815 | * This variant tags control characters to be possibly echoed as |
| 816 | * as "^X" (where X is the letter representing the control char). |
| 817 | * |
| 818 | * Locking: echo_lock to protect the echo buffer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | */ |
| 820 | |
| 821 | static void echo_char(unsigned char c, struct tty_struct *tty) |
| 822 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 823 | mutex_lock(&tty->echo_lock); |
| 824 | |
| 825 | if (c == ECHO_OP_START) { |
| 826 | add_echo_byte(ECHO_OP_START, tty); |
| 827 | add_echo_byte(ECHO_OP_START, tty); |
| 828 | } else { |
| 829 | if (iscntrl(c) && c != '\t') |
| 830 | add_echo_byte(ECHO_OP_START, tty); |
| 831 | add_echo_byte(c, tty); |
| 832 | } |
| 833 | |
| 834 | mutex_unlock(&tty->echo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | } |
| 836 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 837 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 838 | * finish_erasing - complete erase |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 839 | * @tty: tty doing the erase |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 840 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 841 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | static inline void finish_erasing(struct tty_struct *tty) |
| 843 | { |
| 844 | if (tty->erasing) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 845 | echo_char_raw('/', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | tty->erasing = 0; |
| 847 | } |
| 848 | } |
| 849 | |
| 850 | /** |
| 851 | * eraser - handle erase function |
| 852 | * @c: character input |
| 853 | * @tty: terminal device |
| 854 | * |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 855 | * Perform erase and necessary output when an erase character is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | * present in the stream from the driver layer. Handles the complexities |
| 857 | * of UTF-8 multibyte symbols. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 858 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 859 | * Locking: read_lock for tty buffers |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 861 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | static void eraser(unsigned char c, struct tty_struct *tty) |
| 863 | { |
| 864 | enum { ERASE, WERASE, KILL } kill_type; |
| 865 | int head, seen_alnums, cnt; |
| 866 | unsigned long flags; |
| 867 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 868 | /* FIXME: locking needed ? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | if (tty->read_head == tty->canon_head) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 870 | /* echo_char_raw('\a', tty); */ /* what do you think? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | return; |
| 872 | } |
| 873 | if (c == ERASE_CHAR(tty)) |
| 874 | kill_type = ERASE; |
| 875 | else if (c == WERASE_CHAR(tty)) |
| 876 | kill_type = WERASE; |
| 877 | else { |
| 878 | if (!L_ECHO(tty)) { |
| 879 | spin_lock_irqsave(&tty->read_lock, flags); |
| 880 | tty->read_cnt -= ((tty->read_head - tty->canon_head) & |
| 881 | (N_TTY_BUF_SIZE - 1)); |
| 882 | tty->read_head = tty->canon_head; |
| 883 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 884 | return; |
| 885 | } |
| 886 | if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { |
| 887 | spin_lock_irqsave(&tty->read_lock, flags); |
| 888 | tty->read_cnt -= ((tty->read_head - tty->canon_head) & |
| 889 | (N_TTY_BUF_SIZE - 1)); |
| 890 | tty->read_head = tty->canon_head; |
| 891 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 892 | finish_erasing(tty); |
| 893 | echo_char(KILL_CHAR(tty), tty); |
| 894 | /* Add a newline if ECHOK is on and ECHOKE is off. */ |
| 895 | if (L_ECHOK(tty)) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 896 | echo_char_raw('\n', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | return; |
| 898 | } |
| 899 | kill_type = KILL; |
| 900 | } |
| 901 | |
| 902 | seen_alnums = 0; |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 903 | /* FIXME: Locking ?? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | while (tty->read_head != tty->canon_head) { |
| 905 | head = tty->read_head; |
| 906 | |
| 907 | /* erase a single possibly multibyte character */ |
| 908 | do { |
| 909 | head = (head - 1) & (N_TTY_BUF_SIZE-1); |
| 910 | c = tty->read_buf[head]; |
| 911 | } while (is_continuation(c, tty) && head != tty->canon_head); |
| 912 | |
| 913 | /* do not partially erase */ |
| 914 | if (is_continuation(c, tty)) |
| 915 | break; |
| 916 | |
| 917 | if (kill_type == WERASE) { |
| 918 | /* Equivalent to BSD's ALTWERASE. */ |
| 919 | if (isalnum(c) || c == '_') |
| 920 | seen_alnums++; |
| 921 | else if (seen_alnums) |
| 922 | break; |
| 923 | } |
| 924 | cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1); |
| 925 | spin_lock_irqsave(&tty->read_lock, flags); |
| 926 | tty->read_head = head; |
| 927 | tty->read_cnt -= cnt; |
| 928 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 929 | if (L_ECHO(tty)) { |
| 930 | if (L_ECHOPRT(tty)) { |
| 931 | if (!tty->erasing) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 932 | echo_char_raw('\\', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | tty->erasing = 1; |
| 934 | } |
| 935 | /* if cnt > 1, output a multi-byte character */ |
| 936 | echo_char(c, tty); |
| 937 | while (--cnt > 0) { |
| 938 | head = (head+1) & (N_TTY_BUF_SIZE-1); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 939 | echo_char_raw(tty->read_buf[head], tty); |
| 940 | echo_move_back_col(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | } |
| 942 | } else if (kill_type == ERASE && !L_ECHOE(tty)) { |
| 943 | echo_char(ERASE_CHAR(tty), tty); |
| 944 | } else if (c == '\t') { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 945 | unsigned int num_chars = 0; |
| 946 | int after_tab = 0; |
| 947 | unsigned long tail = tty->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 949 | /* |
| 950 | * Count the columns used for characters |
| 951 | * since the start of input or after a |
| 952 | * previous tab. |
| 953 | * This info is used to go back the correct |
| 954 | * number of columns. |
| 955 | */ |
| 956 | while (tail != tty->canon_head) { |
| 957 | tail = (tail-1) & (N_TTY_BUF_SIZE-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | c = tty->read_buf[tail]; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 959 | if (c == '\t') { |
| 960 | after_tab = 1; |
| 961 | break; |
| 962 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | else if (iscntrl(c)) { |
| 964 | if (L_ECHOCTL(tty)) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 965 | num_chars += 2; |
| 966 | } else if (!is_continuation(c, tty)) { |
| 967 | num_chars++; |
| 968 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 970 | echo_erase_tab(num_chars, after_tab, tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | } else { |
| 972 | if (iscntrl(c) && L_ECHOCTL(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 973 | echo_char_raw('\b', tty); |
| 974 | echo_char_raw(' ', tty); |
| 975 | echo_char_raw('\b', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | } |
| 977 | if (!iscntrl(c) || L_ECHOCTL(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 978 | echo_char_raw('\b', tty); |
| 979 | echo_char_raw(' ', tty); |
| 980 | echo_char_raw('\b', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | } |
| 982 | } |
| 983 | } |
| 984 | if (kill_type == ERASE) |
| 985 | break; |
| 986 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 987 | if (tty->read_head == tty->canon_head && L_ECHO(tty)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | finish_erasing(tty); |
| 989 | } |
| 990 | |
| 991 | /** |
| 992 | * isig - handle the ISIG optio |
| 993 | * @sig: signal |
| 994 | * @tty: terminal |
| 995 | * @flush: force flush |
| 996 | * |
| 997 | * Called when a signal is being sent due to terminal input. This |
| 998 | * may caus terminal flushing to take place according to the termios |
| 999 | * settings and character used. Called from the driver receive_buf |
| 1000 | * path so serialized. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1001 | * |
| 1002 | * Locking: ctrl_lock, read_lock (both via flush buffer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1004 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | static inline void isig(int sig, struct tty_struct *tty, int flush) |
| 1006 | { |
Eric W. Biederman | ab521dc | 2007-02-12 00:53:00 -0800 | [diff] [blame] | 1007 | if (tty->pgrp) |
| 1008 | kill_pgrp(tty->pgrp, sig, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | if (flush || !L_NOFLSH(tty)) { |
| 1010 | n_tty_flush_buffer(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1011 | tty_driver_flush_buffer(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | } |
| 1013 | } |
| 1014 | |
| 1015 | /** |
| 1016 | * n_tty_receive_break - handle break |
| 1017 | * @tty: terminal |
| 1018 | * |
| 1019 | * An RS232 break event has been hit in the incoming bitstream. This |
| 1020 | * can cause a variety of events depending upon the termios settings. |
| 1021 | * |
| 1022 | * Called from the receive_buf path so single threaded. |
| 1023 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1024 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | static inline void n_tty_receive_break(struct tty_struct *tty) |
| 1026 | { |
| 1027 | if (I_IGNBRK(tty)) |
| 1028 | return; |
| 1029 | if (I_BRKINT(tty)) { |
| 1030 | isig(SIGINT, tty, 1); |
| 1031 | return; |
| 1032 | } |
| 1033 | if (I_PARMRK(tty)) { |
| 1034 | put_tty_queue('\377', tty); |
| 1035 | put_tty_queue('\0', tty); |
| 1036 | } |
| 1037 | put_tty_queue('\0', tty); |
| 1038 | wake_up_interruptible(&tty->read_wait); |
| 1039 | } |
| 1040 | |
| 1041 | /** |
| 1042 | * n_tty_receive_overrun - handle overrun reporting |
| 1043 | * @tty: terminal |
| 1044 | * |
| 1045 | * Data arrived faster than we could process it. While the tty |
| 1046 | * driver has flagged this the bits that were missed are gone |
| 1047 | * forever. |
| 1048 | * |
| 1049 | * Called from the receive_buf path so single threaded. Does not |
| 1050 | * need locking as num_overrun and overrun_time are function |
| 1051 | * private. |
| 1052 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1053 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1054 | static inline void n_tty_receive_overrun(struct tty_struct *tty) |
| 1055 | { |
| 1056 | char buf[64]; |
| 1057 | |
| 1058 | tty->num_overrun++; |
| 1059 | if (time_before(tty->overrun_time, jiffies - HZ) || |
| 1060 | time_after(tty->overrun_time, jiffies)) { |
| 1061 | printk(KERN_WARNING "%s: %d input overrun(s)\n", |
| 1062 | tty_name(tty, buf), |
| 1063 | tty->num_overrun); |
| 1064 | tty->overrun_time = jiffies; |
| 1065 | tty->num_overrun = 0; |
| 1066 | } |
| 1067 | } |
| 1068 | |
| 1069 | /** |
| 1070 | * n_tty_receive_parity_error - error notifier |
| 1071 | * @tty: terminal device |
| 1072 | * @c: character |
| 1073 | * |
| 1074 | * Process a parity error and queue the right data to indicate |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 1075 | * the error case if necessary. Locking as per n_tty_receive_buf. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | */ |
| 1077 | static inline void n_tty_receive_parity_error(struct tty_struct *tty, |
| 1078 | unsigned char c) |
| 1079 | { |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1080 | if (I_IGNPAR(tty)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | if (I_PARMRK(tty)) { |
| 1083 | put_tty_queue('\377', tty); |
| 1084 | put_tty_queue('\0', tty); |
| 1085 | put_tty_queue(c, tty); |
| 1086 | } else if (I_INPCK(tty)) |
| 1087 | put_tty_queue('\0', tty); |
| 1088 | else |
| 1089 | put_tty_queue(c, tty); |
| 1090 | wake_up_interruptible(&tty->read_wait); |
| 1091 | } |
| 1092 | |
| 1093 | /** |
| 1094 | * n_tty_receive_char - perform processing |
| 1095 | * @tty: terminal device |
| 1096 | * @c: character |
| 1097 | * |
| 1098 | * Process an individual character of input received from the driver. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1099 | * This is serialized with respect to itself by the rules for the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | * driver above. |
| 1101 | */ |
| 1102 | |
| 1103 | static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c) |
| 1104 | { |
| 1105 | unsigned long flags; |
| 1106 | |
| 1107 | if (tty->raw) { |
| 1108 | put_tty_queue(c, tty); |
| 1109 | return; |
| 1110 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1111 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1112 | if (I_ISTRIP(tty)) |
| 1113 | c &= 0x7f; |
| 1114 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1115 | c=tolower(c); |
| 1116 | |
Joe Peterson | 54d2a37 | 2008-02-06 01:37:59 -0800 | [diff] [blame] | 1117 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1118 | I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) && |
| 1119 | c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) { |
Joe Peterson | 54d2a37 | 2008-02-06 01:37:59 -0800 | [diff] [blame] | 1120 | start_tty(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1121 | process_echoes(tty); |
| 1122 | } |
Joe Peterson | 54d2a37 | 2008-02-06 01:37:59 -0800 | [diff] [blame] | 1123 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1124 | if (tty->closing) { |
| 1125 | if (I_IXON(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1126 | if (c == START_CHAR(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1127 | start_tty(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1128 | process_echoes(tty); |
| 1129 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | else if (c == STOP_CHAR(tty)) |
| 1131 | stop_tty(tty); |
| 1132 | } |
| 1133 | return; |
| 1134 | } |
| 1135 | |
| 1136 | /* |
| 1137 | * If the previous character was LNEXT, or we know that this |
| 1138 | * character is not one of the characters that we'll have to |
| 1139 | * handle specially, do shortcut processing to speed things |
| 1140 | * up. |
| 1141 | */ |
| 1142 | if (!test_bit(c, tty->process_char_map) || tty->lnext) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | tty->lnext = 0; |
| 1144 | if (L_ECHO(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1145 | finish_erasing(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1147 | /* beep if no space */ |
| 1148 | echo_char_raw('\a', tty); |
| 1149 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | return; |
| 1151 | } |
| 1152 | /* Record the column of first canon char. */ |
| 1153 | if (tty->canon_head == tty->read_head) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1154 | echo_set_canon_col(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1155 | echo_char(c, tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1156 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | } |
| 1158 | if (I_PARMRK(tty) && c == (unsigned char) '\377') |
| 1159 | put_tty_queue(c, tty); |
| 1160 | put_tty_queue(c, tty); |
| 1161 | return; |
| 1162 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | if (I_IXON(tty)) { |
| 1165 | if (c == START_CHAR(tty)) { |
| 1166 | start_tty(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1167 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1168 | return; |
| 1169 | } |
| 1170 | if (c == STOP_CHAR(tty)) { |
| 1171 | stop_tty(tty); |
| 1172 | return; |
| 1173 | } |
| 1174 | } |
Joe Peterson | 575537b | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1175 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | if (L_ISIG(tty)) { |
| 1177 | int signal; |
| 1178 | signal = SIGINT; |
| 1179 | if (c == INTR_CHAR(tty)) |
| 1180 | goto send_signal; |
| 1181 | signal = SIGQUIT; |
| 1182 | if (c == QUIT_CHAR(tty)) |
| 1183 | goto send_signal; |
| 1184 | signal = SIGTSTP; |
| 1185 | if (c == SUSP_CHAR(tty)) { |
| 1186 | send_signal: |
Joe Peterson | ec5b115 | 2008-02-06 01:37:38 -0800 | [diff] [blame] | 1187 | /* |
Joe Peterson | ec5b115 | 2008-02-06 01:37:38 -0800 | [diff] [blame] | 1188 | * Note that we do not use isig() here because we want |
| 1189 | * the order to be: |
| 1190 | * 1) flush, 2) echo, 3) signal |
| 1191 | */ |
| 1192 | if (!L_NOFLSH(tty)) { |
| 1193 | n_tty_flush_buffer(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1194 | tty_driver_flush_buffer(tty); |
Joe Peterson | ec5b115 | 2008-02-06 01:37:38 -0800 | [diff] [blame] | 1195 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1196 | if (I_IXON(tty)) |
| 1197 | start_tty(tty); |
| 1198 | if (L_ECHO(tty)) { |
Joe Peterson | ec5b115 | 2008-02-06 01:37:38 -0800 | [diff] [blame] | 1199 | echo_char(c, tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1200 | process_echoes(tty); |
| 1201 | } |
Joe Peterson | ec5b115 | 2008-02-06 01:37:38 -0800 | [diff] [blame] | 1202 | if (tty->pgrp) |
| 1203 | kill_pgrp(tty->pgrp, signal, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | return; |
| 1205 | } |
| 1206 | } |
Joe Peterson | 575537b | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1207 | |
| 1208 | if (c == '\r') { |
| 1209 | if (I_IGNCR(tty)) |
| 1210 | return; |
| 1211 | if (I_ICRNL(tty)) |
| 1212 | c = '\n'; |
| 1213 | } else if (c == '\n' && I_INLCR(tty)) |
| 1214 | c = '\r'; |
| 1215 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | if (tty->icanon) { |
| 1217 | if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) || |
| 1218 | (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) { |
| 1219 | eraser(c, tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1220 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | return; |
| 1222 | } |
| 1223 | if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) { |
| 1224 | tty->lnext = 1; |
| 1225 | if (L_ECHO(tty)) { |
| 1226 | finish_erasing(tty); |
| 1227 | if (L_ECHOCTL(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1228 | echo_char_raw('^', tty); |
| 1229 | echo_char_raw('\b', tty); |
| 1230 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | } |
| 1232 | } |
| 1233 | return; |
| 1234 | } |
| 1235 | if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && |
| 1236 | L_IEXTEN(tty)) { |
| 1237 | unsigned long tail = tty->canon_head; |
| 1238 | |
| 1239 | finish_erasing(tty); |
| 1240 | echo_char(c, tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1241 | echo_char_raw('\n', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | while (tail != tty->read_head) { |
| 1243 | echo_char(tty->read_buf[tail], tty); |
| 1244 | tail = (tail+1) & (N_TTY_BUF_SIZE-1); |
| 1245 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1246 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | return; |
| 1248 | } |
| 1249 | if (c == '\n') { |
| 1250 | if (L_ECHO(tty) || L_ECHONL(tty)) { |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 1251 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1252 | echo_char_raw('\a', tty); |
| 1253 | echo_char_raw('\n', tty); |
| 1254 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | } |
| 1256 | goto handle_newline; |
| 1257 | } |
| 1258 | if (c == EOF_CHAR(tty)) { |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1259 | if (tty->canon_head != tty->read_head) |
| 1260 | set_bit(TTY_PUSH, &tty->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | c = __DISABLED_CHAR; |
| 1262 | goto handle_newline; |
| 1263 | } |
| 1264 | if ((c == EOL_CHAR(tty)) || |
| 1265 | (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) { |
| 1266 | /* |
| 1267 | * XXX are EOL_CHAR and EOL2_CHAR echoed?!? |
| 1268 | */ |
| 1269 | if (L_ECHO(tty)) { |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 1270 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1271 | echo_char_raw('\a', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | /* Record the column of first canon char. */ |
| 1273 | if (tty->canon_head == tty->read_head) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1274 | echo_set_canon_col(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | echo_char(c, tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1276 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | } |
| 1278 | /* |
| 1279 | * XXX does PARMRK doubling happen for |
| 1280 | * EOL_CHAR and EOL2_CHAR? |
| 1281 | */ |
| 1282 | if (I_PARMRK(tty) && c == (unsigned char) '\377') |
| 1283 | put_tty_queue(c, tty); |
| 1284 | |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1285 | handle_newline: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | spin_lock_irqsave(&tty->read_lock, flags); |
| 1287 | set_bit(tty->read_head, tty->read_flags); |
| 1288 | put_tty_queue_nolock(c, tty); |
| 1289 | tty->canon_head = tty->read_head; |
| 1290 | tty->canon_data++; |
| 1291 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 1292 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
| 1293 | if (waitqueue_active(&tty->read_wait)) |
| 1294 | wake_up_interruptible(&tty->read_wait); |
| 1295 | return; |
| 1296 | } |
| 1297 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1298 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1299 | if (L_ECHO(tty)) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1300 | finish_erasing(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1302 | /* beep if no space */ |
| 1303 | echo_char_raw('\a', tty); |
| 1304 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1305 | return; |
| 1306 | } |
| 1307 | if (c == '\n') |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1308 | echo_char_raw('\n', tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | else { |
| 1310 | /* Record the column of first canon char. */ |
| 1311 | if (tty->canon_head == tty->read_head) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1312 | echo_set_canon_col(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | echo_char(c, tty); |
| 1314 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1315 | process_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | } |
| 1317 | |
| 1318 | if (I_PARMRK(tty) && c == (unsigned char) '\377') |
| 1319 | put_tty_queue(c, tty); |
| 1320 | |
| 1321 | put_tty_queue(c, tty); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1322 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | |
| 1325 | /** |
| 1326 | * n_tty_write_wakeup - asynchronous I/O notifier |
| 1327 | * @tty: tty device |
| 1328 | * |
| 1329 | * Required for the ptys, serial driver etc. since processes |
| 1330 | * that attach themselves to the master and rely on ASYNC |
| 1331 | * IO must be woken up |
| 1332 | */ |
| 1333 | |
| 1334 | static void n_tty_write_wakeup(struct tty_struct *tty) |
| 1335 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1336 | /* Write out any echoed characters that are still pending */ |
| 1337 | process_echoes(tty); |
| 1338 | |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1339 | if (tty->fasync) { |
| 1340 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | kill_fasync(&tty->fasync, SIGIO, POLL_OUT); |
| 1342 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | } |
| 1344 | |
| 1345 | /** |
| 1346 | * n_tty_receive_buf - data receive |
| 1347 | * @tty: terminal device |
| 1348 | * @cp: buffer |
| 1349 | * @fp: flag buffer |
| 1350 | * @count: characters |
| 1351 | * |
| 1352 | * Called by the terminal driver when a block of characters has |
| 1353 | * been received. This function must be called from soft contexts |
| 1354 | * not from interrupt context. The driver is responsible for making |
| 1355 | * calls one at a time and in order (or using flush_to_ldisc) |
| 1356 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1357 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1359 | char *fp, int count) |
| 1360 | { |
| 1361 | const unsigned char *p; |
| 1362 | char *f, flags = TTY_NORMAL; |
| 1363 | int i; |
| 1364 | char buf[64]; |
| 1365 | unsigned long cpuflags; |
| 1366 | |
| 1367 | if (!tty->read_buf) |
| 1368 | return; |
| 1369 | |
| 1370 | if (tty->real_raw) { |
| 1371 | spin_lock_irqsave(&tty->read_lock, cpuflags); |
| 1372 | i = min(N_TTY_BUF_SIZE - tty->read_cnt, |
| 1373 | N_TTY_BUF_SIZE - tty->read_head); |
| 1374 | i = min(count, i); |
| 1375 | memcpy(tty->read_buf + tty->read_head, cp, i); |
| 1376 | tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); |
| 1377 | tty->read_cnt += i; |
| 1378 | cp += i; |
| 1379 | count -= i; |
| 1380 | |
| 1381 | i = min(N_TTY_BUF_SIZE - tty->read_cnt, |
| 1382 | N_TTY_BUF_SIZE - tty->read_head); |
| 1383 | i = min(count, i); |
| 1384 | memcpy(tty->read_buf + tty->read_head, cp, i); |
| 1385 | tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); |
| 1386 | tty->read_cnt += i; |
| 1387 | spin_unlock_irqrestore(&tty->read_lock, cpuflags); |
| 1388 | } else { |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1389 | for (i = count, p = cp, f = fp; i; i--, p++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | if (f) |
| 1391 | flags = *f++; |
| 1392 | switch (flags) { |
| 1393 | case TTY_NORMAL: |
| 1394 | n_tty_receive_char(tty, *p); |
| 1395 | break; |
| 1396 | case TTY_BREAK: |
| 1397 | n_tty_receive_break(tty); |
| 1398 | break; |
| 1399 | case TTY_PARITY: |
| 1400 | case TTY_FRAME: |
| 1401 | n_tty_receive_parity_error(tty, *p); |
| 1402 | break; |
| 1403 | case TTY_OVERRUN: |
| 1404 | n_tty_receive_overrun(tty); |
| 1405 | break; |
| 1406 | default: |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1407 | printk(KERN_ERR "%s: unknown flag %d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | tty_name(tty, buf), flags); |
| 1409 | break; |
| 1410 | } |
| 1411 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1412 | if (tty->ops->flush_chars) |
| 1413 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | } |
| 1415 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1416 | n_tty_set_room(tty); |
| 1417 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) { |
| 1419 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
| 1420 | if (waitqueue_active(&tty->read_wait)) |
| 1421 | wake_up_interruptible(&tty->read_wait); |
| 1422 | } |
| 1423 | |
| 1424 | /* |
| 1425 | * Check the remaining room for the input canonicalization |
| 1426 | * mode. We don't want to throttle the driver if we're in |
| 1427 | * canonical mode and don't have a newline yet! |
| 1428 | */ |
Alan Cox | 39c2e60 | 2008-04-30 00:54:18 -0700 | [diff] [blame] | 1429 | if (tty->receive_room < TTY_THRESHOLD_THROTTLE) |
| 1430 | tty_throttle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | } |
| 1432 | |
| 1433 | int is_ignored(int sig) |
| 1434 | { |
| 1435 | return (sigismember(¤t->blocked, sig) || |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1436 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | } |
| 1438 | |
| 1439 | /** |
| 1440 | * n_tty_set_termios - termios data changed |
| 1441 | * @tty: terminal |
| 1442 | * @old: previous data |
| 1443 | * |
| 1444 | * Called by the tty layer when the user changes termios flags so |
| 1445 | * that the line discipline can plan ahead. This function cannot sleep |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1446 | * 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] | 1447 | * guaranteed that this function will not be re-entered or in progress |
| 1448 | * when the ldisc is closed. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1449 | * |
| 1450 | * Locking: Caller holds tty->termios_mutex |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1451 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1452 | |
| 1453 | 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] | 1454 | { |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1455 | int canon_change = 1; |
| 1456 | BUG_ON(!tty); |
| 1457 | |
| 1458 | if (old) |
| 1459 | canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON; |
| 1460 | if (canon_change) { |
| 1461 | memset(&tty->read_flags, 0, sizeof tty->read_flags); |
| 1462 | tty->canon_head = tty->read_tail; |
| 1463 | tty->canon_data = 0; |
| 1464 | tty->erasing = 0; |
| 1465 | } |
| 1466 | |
| 1467 | if (canon_change && !L_ICANON(tty) && tty->read_cnt) |
| 1468 | wake_up_interruptible(&tty->read_wait); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1469 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | tty->icanon = (L_ICANON(tty) != 0); |
| 1471 | if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { |
| 1472 | tty->raw = 1; |
| 1473 | tty->real_raw = 1; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1474 | n_tty_set_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | return; |
| 1476 | } |
| 1477 | if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || |
| 1478 | I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || |
| 1479 | I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || |
| 1480 | I_PARMRK(tty)) { |
| 1481 | memset(tty->process_char_map, 0, 256/8); |
| 1482 | |
| 1483 | if (I_IGNCR(tty) || I_ICRNL(tty)) |
| 1484 | set_bit('\r', tty->process_char_map); |
| 1485 | if (I_INLCR(tty)) |
| 1486 | set_bit('\n', tty->process_char_map); |
| 1487 | |
| 1488 | if (L_ICANON(tty)) { |
| 1489 | set_bit(ERASE_CHAR(tty), tty->process_char_map); |
| 1490 | set_bit(KILL_CHAR(tty), tty->process_char_map); |
| 1491 | set_bit(EOF_CHAR(tty), tty->process_char_map); |
| 1492 | set_bit('\n', tty->process_char_map); |
| 1493 | set_bit(EOL_CHAR(tty), tty->process_char_map); |
| 1494 | if (L_IEXTEN(tty)) { |
| 1495 | set_bit(WERASE_CHAR(tty), |
| 1496 | tty->process_char_map); |
| 1497 | set_bit(LNEXT_CHAR(tty), |
| 1498 | tty->process_char_map); |
| 1499 | set_bit(EOL2_CHAR(tty), |
| 1500 | tty->process_char_map); |
| 1501 | if (L_ECHO(tty)) |
| 1502 | set_bit(REPRINT_CHAR(tty), |
| 1503 | tty->process_char_map); |
| 1504 | } |
| 1505 | } |
| 1506 | if (I_IXON(tty)) { |
| 1507 | set_bit(START_CHAR(tty), tty->process_char_map); |
| 1508 | set_bit(STOP_CHAR(tty), tty->process_char_map); |
| 1509 | } |
| 1510 | if (L_ISIG(tty)) { |
| 1511 | set_bit(INTR_CHAR(tty), tty->process_char_map); |
| 1512 | set_bit(QUIT_CHAR(tty), tty->process_char_map); |
| 1513 | set_bit(SUSP_CHAR(tty), tty->process_char_map); |
| 1514 | } |
| 1515 | clear_bit(__DISABLED_CHAR, tty->process_char_map); |
| 1516 | tty->raw = 0; |
| 1517 | tty->real_raw = 0; |
| 1518 | } else { |
| 1519 | tty->raw = 1; |
| 1520 | if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && |
| 1521 | (I_IGNPAR(tty) || !I_INPCK(tty)) && |
| 1522 | (tty->driver->flags & TTY_DRIVER_REAL_RAW)) |
| 1523 | tty->real_raw = 1; |
| 1524 | else |
| 1525 | tty->real_raw = 0; |
| 1526 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1527 | n_tty_set_room(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1528 | /* The termios change make the tty ready for I/O */ |
| 1529 | wake_up_interruptible(&tty->write_wait); |
| 1530 | wake_up_interruptible(&tty->read_wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | } |
| 1532 | |
| 1533 | /** |
| 1534 | * n_tty_close - close the ldisc for this tty |
| 1535 | * @tty: device |
| 1536 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1537 | * Called from the terminal layer when this line discipline is |
| 1538 | * being shut down, either because of a close or becsuse of a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | * discipline change. The function will not be called while other |
| 1540 | * ldisc methods are in progress. |
| 1541 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1542 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | static void n_tty_close(struct tty_struct *tty) |
| 1544 | { |
| 1545 | n_tty_flush_buffer(tty); |
| 1546 | if (tty->read_buf) { |
| 1547 | free_buf(tty->read_buf); |
| 1548 | tty->read_buf = NULL; |
| 1549 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1550 | if (tty->echo_buf) { |
| 1551 | free_buf(tty->echo_buf); |
| 1552 | tty->echo_buf = NULL; |
| 1553 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1554 | } |
| 1555 | |
| 1556 | /** |
| 1557 | * n_tty_open - open an ldisc |
| 1558 | * @tty: terminal to open |
| 1559 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1560 | * Called when this line discipline is being attached to the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1561 | * terminal device. Can sleep. Called serialized so that no |
| 1562 | * other events will occur in parallel. No further open will occur |
| 1563 | * until a close. |
| 1564 | */ |
| 1565 | |
| 1566 | static int n_tty_open(struct tty_struct *tty) |
| 1567 | { |
| 1568 | if (!tty) |
| 1569 | return -EINVAL; |
| 1570 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1571 | /* These are ugly. Currently a malloc failure here can panic */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | if (!tty->read_buf) { |
| 1573 | tty->read_buf = alloc_buf(); |
| 1574 | if (!tty->read_buf) |
| 1575 | return -ENOMEM; |
| 1576 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1577 | if (!tty->echo_buf) { |
| 1578 | tty->echo_buf = alloc_buf(); |
| 1579 | if (!tty->echo_buf) |
| 1580 | return -ENOMEM; |
| 1581 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1582 | memset(tty->read_buf, 0, N_TTY_BUF_SIZE); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1583 | memset(tty->echo_buf, 0, N_TTY_BUF_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | reset_buffer_flags(tty); |
| 1585 | tty->column = 0; |
| 1586 | n_tty_set_termios(tty, NULL); |
| 1587 | tty->minimum_to_wake = 1; |
| 1588 | tty->closing = 0; |
| 1589 | return 0; |
| 1590 | } |
| 1591 | |
| 1592 | static inline int input_available_p(struct tty_struct *tty, int amt) |
| 1593 | { |
| 1594 | if (tty->icanon) { |
| 1595 | if (tty->canon_data) |
| 1596 | return 1; |
| 1597 | } else if (tty->read_cnt >= (amt ? amt : 1)) |
| 1598 | return 1; |
| 1599 | |
| 1600 | return 0; |
| 1601 | } |
| 1602 | |
| 1603 | /** |
| 1604 | * copy_from_read_buf - copy read data directly |
| 1605 | * @tty: terminal device |
| 1606 | * @b: user data |
| 1607 | * @nr: size of data |
| 1608 | * |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1609 | * 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] | 1610 | * ICANON is off; it copies characters straight from the tty queue to |
| 1611 | * user space directly. It can be profitably called twice; once to |
| 1612 | * drain the space from the tail pointer to the (physical) end of the |
| 1613 | * buffer, and once to drain the space from the (physical) beginning of |
| 1614 | * the buffer to head pointer. |
| 1615 | * |
Paul Fulghum | 817d6d3 | 2006-06-28 04:26:47 -0700 | [diff] [blame] | 1616 | * Called under the tty->atomic_read_lock sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1617 | * |
| 1618 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1619 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1620 | static int copy_from_read_buf(struct tty_struct *tty, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | unsigned char __user **b, |
| 1622 | size_t *nr) |
| 1623 | |
| 1624 | { |
| 1625 | int retval; |
| 1626 | size_t n; |
| 1627 | unsigned long flags; |
| 1628 | |
| 1629 | retval = 0; |
| 1630 | spin_lock_irqsave(&tty->read_lock, flags); |
| 1631 | n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail); |
| 1632 | n = min(*nr, n); |
| 1633 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 1634 | if (n) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n); |
| 1636 | n -= retval; |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1637 | tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1638 | spin_lock_irqsave(&tty->read_lock, flags); |
| 1639 | tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1); |
| 1640 | tty->read_cnt -= n; |
| 1641 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 1642 | *b += n; |
| 1643 | *nr -= n; |
| 1644 | } |
| 1645 | return retval; |
| 1646 | } |
| 1647 | |
Al Viro | cc4191d | 2008-03-29 03:08:48 +0000 | [diff] [blame] | 1648 | extern ssize_t redirected_tty_write(struct file *, const char __user *, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1649 | size_t, loff_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | |
| 1651 | /** |
| 1652 | * job_control - check job control |
| 1653 | * @tty: tty |
| 1654 | * @file: file handle |
| 1655 | * |
| 1656 | * Perform job control management checks on this file/tty descriptor |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1657 | * and if appropriate send any needed signals and return a negative |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1658 | * error code if action should be taken. |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1659 | * |
| 1660 | * FIXME: |
| 1661 | * Locking: None - redirected write test is safe, testing |
| 1662 | * current->signal should possibly lock current->sighand |
| 1663 | * pgrp locking ? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1664 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1666 | static int job_control(struct tty_struct *tty, struct file *file) |
| 1667 | { |
| 1668 | /* Job control check -- must be done at start and after |
| 1669 | every sleep (POSIX.1 7.1.1.4). */ |
| 1670 | /* NOTE: not yet done after every sleep pending a thorough |
| 1671 | check of the logic of this change. -- jlc */ |
| 1672 | /* don't stop on /dev/console */ |
| 1673 | if (file->f_op->write != redirected_tty_write && |
| 1674 | current->signal->tty == tty) { |
Eric W. Biederman | ab521dc | 2007-02-12 00:53:00 -0800 | [diff] [blame] | 1675 | if (!tty->pgrp) |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1676 | printk(KERN_ERR "n_tty_read: no tty->pgrp!\n"); |
Eric W. Biederman | ab521dc | 2007-02-12 00:53:00 -0800 | [diff] [blame] | 1677 | else if (task_pgrp(current) != tty->pgrp) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | if (is_ignored(SIGTTIN) || |
Eric W. Biederman | 3e7cd6c | 2007-02-12 00:52:58 -0800 | [diff] [blame] | 1679 | is_current_pgrp_orphaned()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1680 | return -EIO; |
Eric W. Biederman | ab521dc | 2007-02-12 00:53:00 -0800 | [diff] [blame] | 1681 | kill_pgrp(task_pgrp(current), SIGTTIN, 1); |
Oleg Nesterov | 040b636 | 2007-06-01 00:46:53 -0700 | [diff] [blame] | 1682 | set_thread_flag(TIF_SIGPENDING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1683 | return -ERESTARTSYS; |
| 1684 | } |
| 1685 | } |
| 1686 | return 0; |
| 1687 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1688 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | |
| 1690 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1691 | * n_tty_read - read function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | * @tty: tty device |
| 1693 | * @file: file object |
| 1694 | * @buf: userspace buffer pointer |
| 1695 | * @nr: size of I/O |
| 1696 | * |
| 1697 | * Perform reads for the line discipline. We are guaranteed that the |
| 1698 | * line discipline will not be closed under us but we may get multiple |
| 1699 | * parallel readers and must handle this ourselves. We may also get |
| 1700 | * a hangup. Always called in user context, may sleep. |
| 1701 | * |
| 1702 | * This code must be sure never to sleep through a hangup. |
| 1703 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1704 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1705 | 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] | 1706 | unsigned char __user *buf, size_t nr) |
| 1707 | { |
| 1708 | unsigned char __user *b = buf; |
| 1709 | DECLARE_WAITQUEUE(wait, current); |
| 1710 | int c; |
| 1711 | int minimum, time; |
| 1712 | ssize_t retval = 0; |
| 1713 | ssize_t size; |
| 1714 | long timeout; |
| 1715 | unsigned long flags; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1716 | int packet; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1717 | |
| 1718 | do_it_again: |
| 1719 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1720 | BUG_ON(!tty->read_buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | |
| 1722 | c = job_control(tty, file); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1723 | if (c < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | return c; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1725 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | minimum = time = 0; |
| 1727 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 1728 | if (!tty->icanon) { |
| 1729 | time = (HZ / 10) * TIME_CHAR(tty); |
| 1730 | minimum = MIN_CHAR(tty); |
| 1731 | if (minimum) { |
| 1732 | if (time) |
| 1733 | tty->minimum_to_wake = 1; |
| 1734 | else if (!waitqueue_active(&tty->read_wait) || |
| 1735 | (tty->minimum_to_wake > minimum)) |
| 1736 | tty->minimum_to_wake = minimum; |
| 1737 | } else { |
| 1738 | timeout = 0; |
| 1739 | if (time) { |
| 1740 | timeout = time; |
| 1741 | time = 0; |
| 1742 | } |
| 1743 | tty->minimum_to_wake = minimum = 1; |
| 1744 | } |
| 1745 | } |
| 1746 | |
| 1747 | /* |
| 1748 | * Internal serialization of reads. |
| 1749 | */ |
| 1750 | if (file->f_flags & O_NONBLOCK) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1751 | if (!mutex_trylock(&tty->atomic_read_lock)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | return -EAGAIN; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1753 | } else { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1754 | if (mutex_lock_interruptible(&tty->atomic_read_lock)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1755 | return -ERESTARTSYS; |
| 1756 | } |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1757 | packet = tty->packet; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1758 | |
| 1759 | add_wait_queue(&tty->read_wait, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1760 | while (nr) { |
| 1761 | /* First test for status change. */ |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1762 | if (packet && tty->link->ctrl_status) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1763 | unsigned char cs; |
| 1764 | if (b != buf) |
| 1765 | break; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1766 | spin_lock_irqsave(&tty->link->ctrl_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1767 | cs = tty->link->ctrl_status; |
| 1768 | tty->link->ctrl_status = 0; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1769 | spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1770 | if (tty_put_user(tty, cs, b++)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1771 | retval = -EFAULT; |
| 1772 | b--; |
| 1773 | break; |
| 1774 | } |
| 1775 | nr--; |
| 1776 | break; |
| 1777 | } |
| 1778 | /* This statement must be first before checking for input |
| 1779 | so that any interrupt will set the state back to |
| 1780 | TASK_RUNNING. */ |
| 1781 | set_current_state(TASK_INTERRUPTIBLE); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1782 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | if (((minimum - (b - buf)) < tty->minimum_to_wake) && |
| 1784 | ((minimum - (b - buf)) >= 1)) |
| 1785 | tty->minimum_to_wake = (minimum - (b - buf)); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1786 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1787 | if (!input_available_p(tty, 0)) { |
| 1788 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { |
| 1789 | retval = -EIO; |
| 1790 | break; |
| 1791 | } |
| 1792 | if (tty_hung_up_p(file)) |
| 1793 | break; |
| 1794 | if (!timeout) |
| 1795 | break; |
| 1796 | if (file->f_flags & O_NONBLOCK) { |
| 1797 | retval = -EAGAIN; |
| 1798 | break; |
| 1799 | } |
| 1800 | if (signal_pending(current)) { |
| 1801 | retval = -ERESTARTSYS; |
| 1802 | break; |
| 1803 | } |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1804 | /* FIXME: does n_tty_set_room need locking ? */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1805 | n_tty_set_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1806 | timeout = schedule_timeout(timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1807 | continue; |
| 1808 | } |
| 1809 | __set_current_state(TASK_RUNNING); |
| 1810 | |
| 1811 | /* Deal with packet mode. */ |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1812 | if (packet && b == buf) { |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1813 | if (tty_put_user(tty, TIOCPKT_DATA, b++)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1814 | retval = -EFAULT; |
| 1815 | b--; |
| 1816 | break; |
| 1817 | } |
| 1818 | nr--; |
| 1819 | } |
| 1820 | |
| 1821 | if (tty->icanon) { |
| 1822 | /* N.B. avoid overrun if nr == 0 */ |
| 1823 | while (nr && tty->read_cnt) { |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1824 | int eol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1825 | |
| 1826 | eol = test_and_clear_bit(tty->read_tail, |
| 1827 | tty->read_flags); |
| 1828 | c = tty->read_buf[tty->read_tail]; |
| 1829 | spin_lock_irqsave(&tty->read_lock, flags); |
| 1830 | tty->read_tail = ((tty->read_tail+1) & |
| 1831 | (N_TTY_BUF_SIZE-1)); |
| 1832 | tty->read_cnt--; |
| 1833 | if (eol) { |
| 1834 | /* this test should be redundant: |
| 1835 | * we shouldn't be reading data if |
| 1836 | * canon_data is 0 |
| 1837 | */ |
| 1838 | if (--tty->canon_data < 0) |
| 1839 | tty->canon_data = 0; |
| 1840 | } |
| 1841 | spin_unlock_irqrestore(&tty->read_lock, flags); |
| 1842 | |
| 1843 | if (!eol || (c != __DISABLED_CHAR)) { |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1844 | if (tty_put_user(tty, c, b++)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | retval = -EFAULT; |
| 1846 | b--; |
| 1847 | break; |
| 1848 | } |
| 1849 | nr--; |
| 1850 | } |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1851 | if (eol) { |
| 1852 | tty_audit_push(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | break; |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 1854 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1855 | } |
| 1856 | if (retval) |
| 1857 | break; |
| 1858 | } else { |
| 1859 | int uncopied; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 1860 | /* The copy function takes the read lock and handles |
| 1861 | locking internally for this case */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1862 | uncopied = copy_from_read_buf(tty, &b, &nr); |
| 1863 | uncopied += copy_from_read_buf(tty, &b, &nr); |
| 1864 | if (uncopied) { |
| 1865 | retval = -EFAULT; |
| 1866 | break; |
| 1867 | } |
| 1868 | } |
| 1869 | |
| 1870 | /* If there is enough space in the read buffer now, let the |
| 1871 | * low-level driver know. We use n_tty_chars_in_buffer() to |
| 1872 | * check the buffer, as it now knows about canonical mode. |
| 1873 | * Otherwise, if the driver is throttled and the line is |
| 1874 | * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, |
| 1875 | * we won't get any more characters. |
| 1876 | */ |
Paul Mackerras | 289a1e9 | 2006-06-12 12:16:26 +1000 | [diff] [blame] | 1877 | if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) { |
| 1878 | n_tty_set_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | check_unthrottle(tty); |
Paul Mackerras | 289a1e9 | 2006-06-12 12:16:26 +1000 | [diff] [blame] | 1880 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | |
| 1882 | if (b - buf >= minimum) |
| 1883 | break; |
| 1884 | if (time) |
| 1885 | timeout = time; |
| 1886 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1887 | mutex_unlock(&tty->atomic_read_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1888 | remove_wait_queue(&tty->read_wait, &wait); |
| 1889 | |
| 1890 | if (!waitqueue_active(&tty->read_wait)) |
| 1891 | tty->minimum_to_wake = minimum; |
| 1892 | |
| 1893 | __set_current_state(TASK_RUNNING); |
| 1894 | size = b - buf; |
| 1895 | if (size) { |
| 1896 | retval = size; |
| 1897 | if (nr) |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1898 | clear_bit(TTY_PUSH, &tty->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1899 | } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) |
| 1900 | goto do_it_again; |
| 1901 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1902 | n_tty_set_room(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1903 | return retval; |
| 1904 | } |
| 1905 | |
| 1906 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1907 | * n_tty_write - write function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1908 | * @tty: tty device |
| 1909 | * @file: file object |
| 1910 | * @buf: userspace buffer pointer |
| 1911 | * @nr: size of I/O |
| 1912 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1913 | * Write function of the terminal device. This is serialized with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1914 | * respect to other write callers but not to termios changes, reads |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1915 | * and other such events. Since the receive code will echo characters, |
| 1916 | * thus calling driver write methods, the output_lock is used in |
| 1917 | * the output processing functions called here as well as in the |
| 1918 | * echo processing function to protect the column state and space |
| 1919 | * left in the buffer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | * |
| 1921 | * This code must be sure never to sleep through a hangup. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1922 | * |
| 1923 | * Locking: output_lock to protect column state and space left |
| 1924 | * (note that the process_output*() functions take this |
| 1925 | * lock themselves) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1926 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1927 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1928 | 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^] | 1929 | const unsigned char *buf, size_t nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1930 | { |
| 1931 | const unsigned char *b = buf; |
| 1932 | DECLARE_WAITQUEUE(wait, current); |
| 1933 | int c; |
| 1934 | ssize_t retval = 0; |
| 1935 | |
| 1936 | /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */ |
| 1937 | if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) { |
| 1938 | retval = tty_check_change(tty); |
| 1939 | if (retval) |
| 1940 | return retval; |
| 1941 | } |
| 1942 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1943 | /* Write out any echoed characters that are still pending */ |
| 1944 | process_echoes(tty); |
| 1945 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1946 | add_wait_queue(&tty->write_wait, &wait); |
| 1947 | while (1) { |
| 1948 | set_current_state(TASK_INTERRUPTIBLE); |
| 1949 | if (signal_pending(current)) { |
| 1950 | retval = -ERESTARTSYS; |
| 1951 | break; |
| 1952 | } |
| 1953 | if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) { |
| 1954 | retval = -EIO; |
| 1955 | break; |
| 1956 | } |
| 1957 | if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) { |
| 1958 | while (nr > 0) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1959 | ssize_t num = process_output_block(tty, b, nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1960 | if (num < 0) { |
| 1961 | if (num == -EAGAIN) |
| 1962 | break; |
| 1963 | retval = num; |
| 1964 | goto break_out; |
| 1965 | } |
| 1966 | b += num; |
| 1967 | nr -= num; |
| 1968 | if (nr == 0) |
| 1969 | break; |
| 1970 | c = *b; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame^] | 1971 | if (process_output(c, tty) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1972 | break; |
| 1973 | b++; nr--; |
| 1974 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1975 | if (tty->ops->flush_chars) |
| 1976 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1977 | } else { |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 1978 | while (nr > 0) { |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1979 | c = tty->ops->write(tty, b, nr); |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 1980 | if (c < 0) { |
| 1981 | retval = c; |
| 1982 | goto break_out; |
| 1983 | } |
| 1984 | if (!c) |
| 1985 | break; |
| 1986 | b += c; |
| 1987 | nr -= c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1988 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1989 | } |
| 1990 | if (!nr) |
| 1991 | break; |
| 1992 | if (file->f_flags & O_NONBLOCK) { |
| 1993 | retval = -EAGAIN; |
| 1994 | break; |
| 1995 | } |
| 1996 | schedule(); |
| 1997 | } |
| 1998 | break_out: |
| 1999 | __set_current_state(TASK_RUNNING); |
| 2000 | remove_wait_queue(&tty->write_wait, &wait); |
| 2001 | return (b - buf) ? b - buf : retval; |
| 2002 | } |
| 2003 | |
| 2004 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2005 | * n_tty_poll - poll method for N_TTY |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2006 | * @tty: terminal device |
| 2007 | * @file: file accessing it |
| 2008 | * @wait: poll table |
| 2009 | * |
| 2010 | * Called when the line discipline is asked to poll() for data or |
| 2011 | * for special events. This code is not serialized with respect to |
| 2012 | * other events save open/close. |
| 2013 | * |
| 2014 | * This code must be sure never to sleep through a hangup. |
| 2015 | * Called without the kernel lock held - fine |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2016 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2017 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2018 | 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] | 2019 | poll_table *wait) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2020 | { |
| 2021 | unsigned int mask = 0; |
| 2022 | |
| 2023 | poll_wait(file, &tty->read_wait, wait); |
| 2024 | poll_wait(file, &tty->write_wait, wait); |
| 2025 | if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty))) |
| 2026 | mask |= POLLIN | POLLRDNORM; |
| 2027 | if (tty->packet && tty->link->ctrl_status) |
| 2028 | mask |= POLLPRI | POLLIN | POLLRDNORM; |
| 2029 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
| 2030 | mask |= POLLHUP; |
| 2031 | if (tty_hung_up_p(file)) |
| 2032 | mask |= POLLHUP; |
| 2033 | if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) { |
| 2034 | if (MIN_CHAR(tty) && !TIME_CHAR(tty)) |
| 2035 | tty->minimum_to_wake = MIN_CHAR(tty); |
| 2036 | else |
| 2037 | tty->minimum_to_wake = 1; |
| 2038 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2039 | if (tty->ops->write && !tty_is_writelocked(tty) && |
| 2040 | tty_chars_in_buffer(tty) < WAKEUP_CHARS && |
| 2041 | tty_write_room(tty) > 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2042 | mask |= POLLOUT | POLLWRNORM; |
| 2043 | return mask; |
| 2044 | } |
| 2045 | |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2046 | static unsigned long inq_canon(struct tty_struct *tty) |
| 2047 | { |
| 2048 | int nr, head, tail; |
| 2049 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 2050 | if (!tty->canon_data) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2051 | return 0; |
| 2052 | head = tty->canon_head; |
| 2053 | tail = tty->read_tail; |
| 2054 | nr = (head - tail) & (N_TTY_BUF_SIZE-1); |
| 2055 | /* Skip EOF-chars.. */ |
| 2056 | while (head != tail) { |
| 2057 | if (test_bit(tail, tty->read_flags) && |
| 2058 | tty->read_buf[tail] == __DISABLED_CHAR) |
| 2059 | nr--; |
| 2060 | tail = (tail+1) & (N_TTY_BUF_SIZE-1); |
| 2061 | } |
| 2062 | return nr; |
| 2063 | } |
| 2064 | |
| 2065 | static int n_tty_ioctl(struct tty_struct *tty, struct file *file, |
| 2066 | unsigned int cmd, unsigned long arg) |
| 2067 | { |
| 2068 | int retval; |
| 2069 | |
| 2070 | switch (cmd) { |
| 2071 | case TIOCOUTQ: |
| 2072 | return put_user(tty_chars_in_buffer(tty), (int __user *) arg); |
| 2073 | case TIOCINQ: |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 2074 | /* FIXME: Locking */ |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2075 | retval = tty->read_cnt; |
| 2076 | if (L_ICANON(tty)) |
| 2077 | retval = inq_canon(tty); |
| 2078 | return put_user(retval, (unsigned int __user *) arg); |
| 2079 | default: |
| 2080 | return n_tty_ioctl_helper(tty, file, cmd, arg); |
| 2081 | } |
| 2082 | } |
| 2083 | |
Alan Cox | a352def | 2008-07-16 21:53:12 +0100 | [diff] [blame] | 2084 | struct tty_ldisc_ops tty_ldisc_N_TTY = { |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2085 | .magic = TTY_LDISC_MAGIC, |
| 2086 | .name = "n_tty", |
| 2087 | .open = n_tty_open, |
| 2088 | .close = n_tty_close, |
| 2089 | .flush_buffer = n_tty_flush_buffer, |
| 2090 | .chars_in_buffer = n_tty_chars_in_buffer, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2091 | .read = n_tty_read, |
| 2092 | .write = n_tty_write, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2093 | .ioctl = n_tty_ioctl, |
| 2094 | .set_termios = n_tty_set_termios, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2095 | .poll = n_tty_poll, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2096 | .receive_buf = n_tty_receive_buf, |
| 2097 | .write_wakeup = n_tty_write_wakeup |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2098 | }; |