364 lines
8.1 KiB
C
364 lines
8.1 KiB
C
/*-
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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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* 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/filio.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/poll.h>
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#include <sys/proc.h>
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#include <sys/snoop.h>
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#include <sys/sx.h>
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#include <sys/systm.h>
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#include <sys/tty.h>
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#include <sys/uio.h>
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static struct cdev *snp_dev;
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static MALLOC_DEFINE(M_SNP, "snp", "tty snoop device");
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/* XXX: should be mtx, but TTY can be locked by Giant. */
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#if 0
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static struct mtx snp_register_lock;
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MTX_SYSINIT(snp_register_lock, &snp_register_lock,
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"tty snoop registration", MTX_DEF);
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#define SNP_LOCK() mtx_lock(&snp_register_lock)
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#define SNP_UNLOCK() mtx_unlock(&snp_register_lock)
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#else
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static struct sx snp_register_lock;
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SX_SYSINIT(snp_register_lock, &snp_register_lock,
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"tty snoop registration");
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#define SNP_LOCK() sx_xlock(&snp_register_lock)
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#define SNP_UNLOCK() sx_xunlock(&snp_register_lock)
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#endif
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/*
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* There is no need to have a big input buffer. In most typical setups,
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* we won't inject much data into the TTY, because users can't type
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* really fast.
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*/
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#define SNP_INPUT_BUFSIZE 16
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/*
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* The output buffer has to be really big. Right now we don't support
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* any form of flow control, which means we lost any data we can't
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* accept. We set the output buffer size to about twice the size of a
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* pseudo-terminal/virtual console's output buffer.
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*/
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#define SNP_OUTPUT_BUFSIZE 16384
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static d_open_t snp_open;
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static d_read_t snp_read;
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static d_write_t snp_write;
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static d_ioctl_t snp_ioctl;
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static d_poll_t snp_poll;
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static struct cdevsw snp_cdevsw = {
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.d_version = D_VERSION,
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.d_open = snp_open,
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.d_read = snp_read,
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.d_write = snp_write,
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.d_ioctl = snp_ioctl,
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.d_poll = snp_poll,
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.d_name = "snp",
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};
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static th_getc_capture_t snp_getc_capture;
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static struct ttyhook snp_hook = {
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.th_getc_capture = snp_getc_capture,
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};
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/*
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* Per-instance structure.
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*
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* List of locks
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* (r) locked by snp_register_lock on assignment
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* (t) locked by tty_lock
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*/
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struct snp_softc {
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struct tty *snp_tty; /* (r) TTY we're snooping. */
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struct ttyoutq snp_outq; /* (t) Output queue. */
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struct cv snp_outwait; /* (t) Output wait queue. */
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struct selinfo snp_outpoll; /* (t) Output polling. */
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};
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static void
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snp_dtor(void *data)
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{
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struct snp_softc *ss = data;
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struct tty *tp;
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tp = ss->snp_tty;
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if (tp != NULL) {
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tty_lock(tp);
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ttyoutq_free(&ss->snp_outq);
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ttyhook_unregister(tp);
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}
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cv_destroy(&ss->snp_outwait);
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free(ss, M_SNP);
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}
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/*
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* Snoop device node routines.
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*/
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static int
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snp_open(struct cdev *dev, int flag, int mode, struct thread *td)
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{
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struct snp_softc *ss;
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/* Allocate per-snoop data. */
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ss = malloc(sizeof(struct snp_softc), M_SNP, M_WAITOK|M_ZERO);
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cv_init(&ss->snp_outwait, "snp out");
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devfs_set_cdevpriv(ss, snp_dtor);
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return (0);
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}
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static int
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snp_read(struct cdev *dev, struct uio *uio, int flag)
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{
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int error, oresid = uio->uio_resid;
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struct snp_softc *ss;
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struct tty *tp;
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if (uio->uio_resid == 0)
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return (0);
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error = devfs_get_cdevpriv((void **)&ss);
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if (error != 0)
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return (error);
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tp = ss->snp_tty;
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if (tp == NULL || tty_gone(tp))
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return (EIO);
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tty_lock(tp);
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for (;;) {
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error = ttyoutq_read_uio(&ss->snp_outq, tp, uio);
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if (error != 0 || uio->uio_resid != oresid)
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break;
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/* Wait for more data. */
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if (flag & O_NONBLOCK) {
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error = EWOULDBLOCK;
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break;
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}
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error = cv_wait_sig(&ss->snp_outwait, tp->t_mtx);
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if (error != 0)
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break;
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if (tty_gone(tp)) {
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error = EIO;
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break;
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}
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}
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tty_unlock(tp);
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return (error);
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}
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static int
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snp_write(struct cdev *dev, struct uio *uio, int flag)
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{
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struct snp_softc *ss;
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struct tty *tp;
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int error, len, i;
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char in[SNP_INPUT_BUFSIZE];
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error = devfs_get_cdevpriv((void **)&ss);
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if (error != 0)
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return (error);
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tp = ss->snp_tty;
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if (tp == NULL || tty_gone(tp))
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return (EIO);
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while (uio->uio_resid > 0) {
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/* Read new data. */
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len = imin(uio->uio_resid, sizeof in);
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error = uiomove(in, len, uio);
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if (error != 0)
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return (error);
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tty_lock(tp);
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/* Driver could have abandoned the TTY in the mean time. */
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if (tty_gone(tp)) {
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tty_unlock(tp);
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return (ENXIO);
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}
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/*
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* Deliver data to the TTY. Ignore errors for now,
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* because we shouldn't bail out when we're running
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* close to the watermarks.
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*/
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if (ttydisc_can_bypass(tp)) {
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ttydisc_rint_bypass(tp, in, len);
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} else {
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for (i = 0; i < len; i++)
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ttydisc_rint(tp, in[i], 0);
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}
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ttydisc_rint_done(tp);
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tty_unlock(tp);
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}
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return (0);
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}
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static int
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snp_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
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struct thread *td)
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{
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struct snp_softc *ss;
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struct tty *tp;
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int error;
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error = devfs_get_cdevpriv((void **)&ss);
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if (error != 0)
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return (error);
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switch (cmd) {
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case SNPSTTY:
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/* Bind TTY to snoop instance. */
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SNP_LOCK();
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if (ss->snp_tty != NULL) {
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SNP_UNLOCK();
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return (EBUSY);
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}
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error = ttyhook_register(&ss->snp_tty, td->td_proc,
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*(int *)data, &snp_hook, ss);
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SNP_UNLOCK();
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if (error != 0)
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return (error);
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/* Now that went okay, allocate a buffer for the queue. */
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tp = ss->snp_tty;
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tty_lock(tp);
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ttyoutq_setsize(&ss->snp_outq, tp, SNP_OUTPUT_BUFSIZE);
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tty_unlock(tp);
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return (0);
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case SNPGTTY:
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/* Obtain device number of associated TTY. */
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if (ss->snp_tty == NULL)
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*(dev_t *)data = NODEV;
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else
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*(dev_t *)data = tty_udev(ss->snp_tty);
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return (0);
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case FIONREAD:
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tp = ss->snp_tty;
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if (tp != NULL) {
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tty_lock(tp);
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*(int *)data = ttyoutq_bytesused(&ss->snp_outq);
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tty_unlock(tp);
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} else {
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*(int *)data = 0;
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}
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return (0);
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default:
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return (ENOTTY);
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}
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}
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static int
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snp_poll(struct cdev *dev, int events, struct thread *td)
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{
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struct snp_softc *ss;
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struct tty *tp;
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int revents;
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if (devfs_get_cdevpriv((void **)&ss) != 0)
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return (events &
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(POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
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revents = 0;
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if (events & (POLLIN | POLLRDNORM)) {
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tp = ss->snp_tty;
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if (tp != NULL) {
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tty_lock(tp);
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if (ttyoutq_bytesused(&ss->snp_outq) > 0)
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revents |= events & (POLLIN | POLLRDNORM);
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tty_unlock(tp);
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}
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}
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if (revents == 0)
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selrecord(td, &ss->snp_outpoll);
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return (revents);
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}
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/*
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* TTY hook events.
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*/
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static int
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snp_modevent(module_t mod, int type, void *data)
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{
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switch (type) {
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case MOD_LOAD:
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snp_dev = make_dev(&snp_cdevsw, 0,
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UID_ROOT, GID_WHEEL, 0600, "snp");
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return (0);
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case MOD_UNLOAD:
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/* XXX: Make existing users leave. */
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destroy_dev(snp_dev);
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return (0);
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default:
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return (EOPNOTSUPP);
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}
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}
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static void
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snp_getc_capture(struct tty *tp, const void *buf, size_t len)
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{
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struct snp_softc *ss = ttyhook_softc(tp);
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ttyoutq_write(&ss->snp_outq, buf, len);
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cv_broadcast(&ss->snp_outwait);
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selwakeup(&ss->snp_outpoll);
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}
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static moduledata_t snp_mod = {
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"snp",
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snp_modevent,
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NULL
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};
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DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
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