508 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			508 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*
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|  * Copyright (c) 2006-2023, RT-Thread Development Team
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|  *
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|  * SPDX-License-Identifier: Apache-2.0
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|  *
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|  * Change Logs:
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|  * Date           Author       Notes
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|  * 2023-11-13     Shell        init ver.
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|  */
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| 
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| #include "../bsd_porting.h"
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| #include "../terminal.h"
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| 
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| /*-
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  *
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|  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
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|  * All rights reserved.
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|  *
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|  * Portions of this software were developed under sponsorship from Snow
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|  * B.V., the Netherlands.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| /*
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|  * TTY input queue buffering.
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|  *
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|  * Unlike the output queue, the input queue has more features that are
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|  * needed to properly implement various features offered by the TTY
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|  * interface:
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|  *
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|  * - Data can be removed from the tail of the queue, which is used to
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|  *   implement backspace.
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|  * - Once in a while, input has to be `canonicalized'. When ICANON is
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|  *   turned on, this will be done after a CR has been inserted.
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|  *   Otherwise, it should be done after any character has been inserted.
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|  * - The input queue can store one bit per byte, called the quoting bit.
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|  *   This bit is used by TTYDISC to make backspace work on quoted
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|  *   characters.
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|  *
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|  * In most cases, there is probably less input than output, so unlike
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|  * the outq, we'll stick to 128 byte blocks here.
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|  */
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| 
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| static int ttyinq_flush_secure = 1;
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| 
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| #define TTYINQ_QUOTESIZE (TTYINQ_DATASIZE / BMSIZE)
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| #define BMSIZE           32
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| #define GETBIT(tib, boff) \
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|     ((tib)->tib_quotes[(boff) / BMSIZE] & (1 << ((boff) % BMSIZE)))
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| #define SETBIT(tib, boff) \
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|     ((tib)->tib_quotes[(boff) / BMSIZE] |= (1 << ((boff) % BMSIZE)))
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| #define CLRBIT(tib, boff) \
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|     ((tib)->tib_quotes[(boff) / BMSIZE] &= ~(1 << ((boff) % BMSIZE)))
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| 
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| struct ttyinq_block
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| {
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|     struct ttyinq_block *tib_prev;
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|     struct ttyinq_block *tib_next;
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|     uint32_t tib_quotes[TTYINQ_QUOTESIZE];
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|     char tib_data[TTYINQ_DATASIZE];
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| };
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| 
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| static uma_zone_t ttyinq_zone;
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| 
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| #define TTYINQ_INSERT_TAIL(ti, tib)                     \
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|     do                                                  \
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|     {                                                   \
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|         if (ti->ti_end == 0)                            \
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|         {                                               \
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|             tib->tib_prev = NULL;                       \
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|             tib->tib_next = ti->ti_firstblock;          \
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|             ti->ti_firstblock = tib;                    \
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|         }                                               \
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|         else                                            \
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|         {                                               \
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|             tib->tib_prev = ti->ti_lastblock;           \
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|             tib->tib_next = ti->ti_lastblock->tib_next; \
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|             ti->ti_lastblock->tib_next = tib;           \
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|         }                                               \
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|         if (tib->tib_next != NULL)                      \
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|             tib->tib_next->tib_prev = tib;              \
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|         ti->ti_nblocks++;                               \
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|     } while (0)
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| 
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| #define TTYINQ_REMOVE_HEAD(ti)                           \
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|     do                                                   \
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|     {                                                    \
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|         ti->ti_firstblock = ti->ti_firstblock->tib_next; \
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|         if (ti->ti_firstblock != NULL)                   \
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|             ti->ti_firstblock->tib_prev = NULL;          \
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|         ti->ti_nblocks--;                                \
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|     } while (0)
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| 
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| #define TTYINQ_RECYCLE(ti, tib)             \
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|     do                                      \
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|     {                                       \
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|         if (ti->ti_quota <= ti->ti_nblocks) \
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|             uma_zfree(ttyinq_zone, tib);    \
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|         else                                \
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|             TTYINQ_INSERT_TAIL(ti, tib);    \
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|     } while (0)
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| 
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| int ttyinq_setsize(struct ttyinq *ti, struct lwp_tty *tp, size_t size)
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| {
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|     struct ttyinq_block *tib;
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| 
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|     ti->ti_quota = howmany(size, TTYINQ_DATASIZE);
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| 
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|     while (ti->ti_quota > ti->ti_nblocks)
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|     {
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|         /*
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|          * List is getting bigger.
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|          * Add new blocks to the tail of the list.
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|          *
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|          * We must unlock the TTY temporarily, because we need
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|          * to allocate memory. This won't be a problem, because
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|          * in the worst case, another thread ends up here, which
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|          * may cause us to allocate too many blocks, but this
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|          * will be caught by the loop below.
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|          */
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|         tty_unlock(tp);
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|         tib = uma_zalloc(ttyinq_zone, M_WAITOK);
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|         tty_lock(tp);
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| 
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|         if (tty_gone(tp))
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|         {
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|             uma_zfree(ttyinq_zone, tib);
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|             return -ENXIO;
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|         }
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| 
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|         TTYINQ_INSERT_TAIL(ti, tib);
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|     }
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|     return 0;
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| }
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| 
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| void ttyinq_free(struct ttyinq *ti)
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| {
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|     struct ttyinq_block *tib;
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| 
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|     ttyinq_flush(ti);
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|     ti->ti_quota = 0;
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| 
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|     while ((tib = ti->ti_firstblock) != NULL)
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|     {
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|         TTYINQ_REMOVE_HEAD(ti);
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|         uma_zfree(ttyinq_zone, tib);
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|     }
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| 
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|     MPASS(ti->ti_nblocks == 0);
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| }
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| 
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| int ttyinq_read_uio(struct ttyinq *ti, struct lwp_tty *tp, struct uio *uio,
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|                     size_t rlen, size_t flen)
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| {
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|     MPASS(rlen <= uio->uio_resid);
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| 
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|     while (rlen > 0)
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|     {
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|         int error;
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|         struct ttyinq_block *tib;
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|         size_t cbegin, cend, clen;
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| 
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|         /* See if there still is data. */
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|         if (ti->ti_begin == ti->ti_linestart)
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|             return 0;
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|         tib = ti->ti_firstblock;
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|         if (tib == NULL)
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|             return 0;
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| 
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|         /*
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|          * The end address should be the lowest of these three:
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|          * - The write pointer
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|          * - The blocksize - we can't read beyond the block
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|          * - The end address if we could perform the full read
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|          */
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|         cbegin = ti->ti_begin;
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|         cend = MIN(MIN(ti->ti_linestart, ti->ti_begin + rlen), TTYINQ_DATASIZE);
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|         clen = cend - cbegin;
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|         MPASS(clen >= flen);
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|         rlen -= clen;
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| 
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|         /*
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|          * We can prevent buffering in some cases:
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|          * - We need to read the block until the end.
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|          * - We don't need to read the block until the end, but
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|          *   there is no data beyond it, which allows us to move
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|          *   the write pointer to a new block.
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|          */
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|         if (cend == TTYINQ_DATASIZE || cend == ti->ti_end)
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|         {
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|             /*
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|              * Fast path: zero copy. Remove the first block,
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|              * so we can unlock the TTY temporarily.
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|              */
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|             TTYINQ_REMOVE_HEAD(ti);
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|             ti->ti_begin = 0;
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| 
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|             /*
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|              * Because we remove the first block, we must
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|              * fix up the block offsets.
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|              */
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| #define CORRECT_BLOCK(t)          \
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|     do                            \
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|     {                             \
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|         if (t <= TTYINQ_DATASIZE) \
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|             t = 0;                \
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|         else                      \
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|             t -= TTYINQ_DATASIZE; \
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|     } while (0)
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|             CORRECT_BLOCK(ti->ti_linestart);
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|             CORRECT_BLOCK(ti->ti_reprint);
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|             CORRECT_BLOCK(ti->ti_end);
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| #undef CORRECT_BLOCK
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| 
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|             /*
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|              * Temporary unlock and copy the data to
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|              * userspace. We may need to flush trailing
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|              * bytes, like EOF characters.
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|              */
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|             tty_unlock(tp);
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|             error = uiomove(tib->tib_data + cbegin, clen - flen, uio);
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|             tty_lock(tp);
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| 
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|             /* Block can now be readded to the list. */
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|             TTYINQ_RECYCLE(ti, tib);
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|         }
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|         else
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|         {
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|             char ob[TTYINQ_DATASIZE - 1];
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| 
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|             /*
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|              * Slow path: store data in a temporary buffer.
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|              */
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|             memcpy(ob, tib->tib_data + cbegin, clen - flen);
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|             ti->ti_begin += clen;
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|             MPASS(ti->ti_begin < TTYINQ_DATASIZE);
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| 
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|             /* Temporary unlock and copy the data to userspace. */
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|             tty_unlock(tp);
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|             error = uiomove(ob, clen - flen, uio);
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|             tty_lock(tp);
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|         }
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| 
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|         if (error != 0)
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|             return error;
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|         if (tty_gone(tp))
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|             return -ENXIO;
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|     }
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| 
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|     return 0;
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| }
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| 
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| rt_inline void ttyinq_set_quotes(struct ttyinq_block *tib, size_t offset,
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|                                  size_t length, int value)
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| {
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|     if (value)
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|     {
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|         /* Set the bits. */
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|         for (; length > 0; length--, offset++) SETBIT(tib, offset);
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|     }
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|     else
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|     {
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|         /* Unset the bits. */
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|         for (; length > 0; length--, offset++) CLRBIT(tib, offset);
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|     }
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| }
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| 
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| size_t ttyinq_write(struct ttyinq *ti, const void *buf, size_t nbytes,
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|                     int quote)
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| {
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|     const char *cbuf = buf;
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|     struct ttyinq_block *tib;
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|     unsigned int boff;
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|     size_t l;
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| 
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|     while (nbytes > 0)
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|     {
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|         boff = ti->ti_end % TTYINQ_DATASIZE;
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| 
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|         if (ti->ti_end == 0)
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|         {
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|             /* First time we're being used or drained. */
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|             MPASS(ti->ti_begin == 0);
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|             tib = ti->ti_firstblock;
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|             if (tib == NULL)
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|             {
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|                 /* Queue has no blocks. */
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|                 break;
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|             }
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|             ti->ti_lastblock = tib;
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|         }
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|         else if (boff == 0)
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|         {
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|             /* We reached the end of this block on last write. */
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|             tib = ti->ti_lastblock->tib_next;
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|             if (tib == NULL)
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|             {
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|                 /* We've reached the watermark. */
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|                 break;
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|             }
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|             ti->ti_lastblock = tib;
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|         }
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|         else
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|         {
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|             tib = ti->ti_lastblock;
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|         }
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| 
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|         /* Don't copy more than was requested. */
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|         l = MIN(nbytes, TTYINQ_DATASIZE - boff);
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|         MPASS(l > 0);
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|         memcpy(tib->tib_data + boff, cbuf, l);
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| 
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|         /* Set the quoting bits for the proper region. */
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|         ttyinq_set_quotes(tib, boff, l, quote);
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| 
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|         cbuf += l;
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|         nbytes -= l;
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|         ti->ti_end += l;
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|     }
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| 
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|     return (cbuf - (const char *)buf);
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| }
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| 
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| int ttyinq_write_nofrag(struct ttyinq *ti, const void *buf, size_t nbytes,
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|                         int quote)
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| {
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|     size_t ret __unused;
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| 
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|     if (ttyinq_bytesleft(ti) < nbytes)
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|         return -1;
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| 
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|     /* We should always be able to write it back. */
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|     ret = ttyinq_write(ti, buf, nbytes, quote);
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|     MPASS(ret == nbytes);
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| 
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|     return 0;
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| }
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| 
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| void ttyinq_canonicalize(struct ttyinq *ti)
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| {
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|     ti->ti_linestart = ti->ti_reprint = ti->ti_end;
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|     ti->ti_startblock = ti->ti_reprintblock = ti->ti_lastblock;
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| }
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| 
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| size_t ttyinq_findchar(struct ttyinq *ti, const char *breakc, size_t maxlen,
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|                        char *lastc)
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| {
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|     struct ttyinq_block *tib = ti->ti_firstblock;
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|     unsigned int boff = ti->ti_begin;
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|     unsigned int bend =
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|         MIN(MIN(TTYINQ_DATASIZE, ti->ti_linestart), ti->ti_begin + maxlen);
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| 
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|     MPASS(maxlen > 0);
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| 
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|     if (tib == NULL)
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|         return 0;
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| 
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|     while (boff < bend)
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|     {
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|         if (strchr(breakc, tib->tib_data[boff]) && !GETBIT(tib, boff))
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|         {
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|             *lastc = tib->tib_data[boff];
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|             return (boff - ti->ti_begin + 1);
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|         }
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|         boff++;
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|     }
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| 
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|     /* Not found - just process the entire block. */
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|     return (bend - ti->ti_begin);
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| }
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| 
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| void ttyinq_flush(struct ttyinq *ti)
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| {
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|     struct ttyinq_block *tib;
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| 
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|     ti->ti_begin = 0;
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|     ti->ti_linestart = 0;
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|     ti->ti_reprint = 0;
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|     ti->ti_end = 0;
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| 
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|     /* Zero all data in the input queue to get rid of passwords. */
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|     if (ttyinq_flush_secure)
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|     {
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|         for (tib = ti->ti_firstblock; tib != NULL; tib = tib->tib_next)
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|             memset(&tib->tib_data, 0, sizeof tib->tib_data);
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|     }
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| }
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| 
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| int ttyinq_peekchar(struct ttyinq *ti, char *c, int *quote)
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| {
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|     unsigned int boff;
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|     struct ttyinq_block *tib = ti->ti_lastblock;
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| 
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|     if (ti->ti_linestart == ti->ti_end)
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|         return -1;
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| 
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|     MPASS(ti->ti_end > 0);
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|     boff = (ti->ti_end - 1) % TTYINQ_DATASIZE;
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| 
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|     *c = tib->tib_data[boff];
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|     *quote = GETBIT(tib, boff);
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| 
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|     return 0;
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| }
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| 
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| void ttyinq_unputchar(struct ttyinq *ti)
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| {
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|     MPASS(ti->ti_linestart < ti->ti_end);
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| 
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|     if (--ti->ti_end % TTYINQ_DATASIZE == 0)
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|     {
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|         /* Roll back to the previous block. */
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|         ti->ti_lastblock = ti->ti_lastblock->tib_prev;
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|         /*
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|          * This can only fail if we are unputchar()'ing the
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|          * first character in the queue.
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|          */
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|         MPASS((ti->ti_lastblock == NULL) == (ti->ti_end == 0));
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|     }
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| }
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| 
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| void ttyinq_reprintpos_set(struct ttyinq *ti)
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| {
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|     ti->ti_reprint = ti->ti_end;
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|     ti->ti_reprintblock = ti->ti_lastblock;
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| }
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| 
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| void ttyinq_reprintpos_reset(struct ttyinq *ti)
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| {
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|     ti->ti_reprint = ti->ti_linestart;
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|     ti->ti_reprintblock = ti->ti_startblock;
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| }
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| 
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| static void ttyinq_line_iterate(struct ttyinq *ti,
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|                                 ttyinq_line_iterator_t *iterator, void *data,
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|                                 unsigned int offset, struct ttyinq_block *tib)
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| {
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|     unsigned int boff;
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| 
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|     /* Use the proper block when we're at the queue head. */
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|     if (offset == 0)
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|         tib = ti->ti_firstblock;
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| 
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|     /* Iterate all characters and call the iterator function. */
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|     for (; offset < ti->ti_end; offset++)
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|     {
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|         boff = offset % TTYINQ_DATASIZE;
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|         MPASS(tib != NULL);
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| 
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|         /* Call back the iterator function. */
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|         iterator(data, tib->tib_data[boff], GETBIT(tib, boff));
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| 
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|         /* Last byte iterated - go to the next block. */
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|         if (boff == TTYINQ_DATASIZE - 1)
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|             tib = tib->tib_next;
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|     }
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| }
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| 
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| void ttyinq_line_iterate_from_linestart(struct ttyinq *ti,
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|                                         ttyinq_line_iterator_t *iterator,
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|                                         void *data)
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| {
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|     ttyinq_line_iterate(ti, iterator, data, ti->ti_linestart,
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|                         ti->ti_startblock);
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| }
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| 
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| void ttyinq_line_iterate_from_reprintpos(struct ttyinq *ti,
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|                                          ttyinq_line_iterator_t *iterator,
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|                                          void *data)
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| {
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|     ttyinq_line_iterate(ti, iterator, data, ti->ti_reprint,
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|                         ti->ti_reprintblock);
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| }
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| 
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| static int ttyinq_startup(void)
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| {
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|     ttyinq_zone = uma_zcreate("ttyinq", sizeof(struct ttyinq_block), NULL, NULL,
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|                               NULL, NULL, UMA_ALIGN_PTR, 0);
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|     return 0;
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| }
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| INIT_PREV_EXPORT(ttyinq_startup);
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| 
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| #if 0
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| 
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| SYSINIT(ttyinq, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyinq_startup, NULL);
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| #endif
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