mirror of
https://github.com/freebsd/freebsd-src
synced 2024-10-19 23:03:55 +00:00
47eaa5f542
needs instead of relying on idiosyncratic hacks in the tty subsystem. Also add module code since this can now be compiled as a module. Silence by: -hackers, -audit
599 lines
12 KiB
C
599 lines
12 KiB
C
/*
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* Copyright (c) 1995 Ugen J.S.Antsilevich
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*
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* Redistribution and use in source forms, with and without modification,
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* are permitted provided that this entire comment appears intact.
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*
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* Redistribution in binary form may occur without any restrictions.
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* Obviously, it would be nice if you gave credit where credit is due
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* but requiring it would be too onerous.
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*
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* This software is provided ``AS IS'' without any warranties of any kind.
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*
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* Snoop stuff.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/filio.h>
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
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#include <sys/ioctl_compat.h>
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#endif
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#include <sys/malloc.h>
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#include <sys/tty.h>
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#include <sys/conf.h>
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#include <sys/poll.h>
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#include <sys/kernel.h>
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#include <sys/snoop.h>
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#include <sys/vnode.h>
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#include <sys/conf.h>
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static d_open_t snpopen;
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static d_close_t snpclose;
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static d_read_t snpread;
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static d_write_t snpwrite;
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static d_ioctl_t snpioctl;
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static d_poll_t snppoll;
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#define CDEV_MAJOR 53
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static struct cdevsw snp_cdevsw = {
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/* open */ snpopen,
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/* close */ snpclose,
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/* read */ snpread,
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/* write */ snpwrite,
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/* ioctl */ snpioctl,
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/* poll */ snppoll,
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/* mmap */ nommap,
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/* strategy */ nostrategy,
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/* name */ "snp",
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/* maj */ CDEV_MAJOR,
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/* dump */ nodump,
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/* psize */ nopsize,
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/* flags */ 0,
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};
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#ifndef MIN
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#define MIN(a,b) (((a)<(b))?(a):(b))
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#endif
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static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data");
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#define ttytosnp(t) (struct snoop *)(t)->t_sc
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static struct tty *snpdevtotty __P((dev_t dev));
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static int snp_detach __P((struct snoop *snp));
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/*
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* The number of the "snoop" line discipline. This gets determined at
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* module load time.
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*/
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static int mylinedisc;
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static int
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dsnwrite(struct tty *tp, struct uio *uio, int flag)
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{
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struct snoop *snp = ttytosnp(tp);
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int error = 0;
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char ibuf[1024];
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int ilen;
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struct iovec iov;
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struct uio uio2;
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while (uio->uio_resid) {
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ilen = MIN(sizeof(ibuf), uio->uio_resid);
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error = uiomove(ibuf, ilen, uio);
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if (error)
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break;
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snpin(snp, ibuf, ilen);
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/* Hackish, but I think it's the least of all evils. */
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iov.iov_base = ibuf;
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iov.iov_len = ilen;
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uio2.uio_iov = &iov;
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uio2.uio_iovcnt = 1;
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uio2.uio_offset = 0;
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uio2.uio_resid = ilen;
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uio2.uio_segflg = UIO_SYSSPACE;
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uio2.uio_rw = UIO_WRITE;
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uio2.uio_procp = uio->uio_procp;
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error = ttwrite(tp, &uio2, flag);
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if (error)
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break;
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}
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return (error);
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}
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/*
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* XXX should there be a global version of this?
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*/
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static int
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l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, struct proc *p)
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{
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return (ENOIOCTL);
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}
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static struct linesw snpdisc = {
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ttyopen, ttylclose, ttread, dsnwrite,
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l_nullioctl, ttyinput, ttstart, ttymodem };
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static struct tty *
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snpdevtotty (dev)
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dev_t dev;
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{
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struct cdevsw *cdp;
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cdp = devsw(dev);
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if (cdp && cdp->d_flags & D_TTY)
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return (dev->si_tty);
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return (NULL);
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}
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#define SNP_INPUT_BUF 5 /* This is even too much, the maximal
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* interactive mode write is 3 bytes
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* length for function keys...
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*/
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static int
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snpwrite(dev, uio, flag)
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dev_t dev;
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struct uio *uio;
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int flag;
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{
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int len, i, error;
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struct snoop *snp = dev->si_drv1;
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struct tty *tp;
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char c[SNP_INPUT_BUF];
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if (snp->snp_tty == NULL)
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return (EIO);
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tp = snp->snp_tty;
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if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
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tp->t_line == mylinedisc)
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goto tty_input;
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printf("Snoop: attempt to write to bad tty.\n");
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return (EIO);
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tty_input:
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if (!(tp->t_state & TS_ISOPEN))
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return (EIO);
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while (uio->uio_resid > 0) {
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len = MIN(uio->uio_resid, SNP_INPUT_BUF);
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if ((error = uiomove(c, len, uio)) != 0)
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return (error);
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for (i=0; i < len; i++) {
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if (ttyinput(c[i], tp))
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return (EIO);
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}
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}
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return 0;
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}
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static int
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snpread(dev, uio, flag)
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dev_t dev;
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struct uio *uio;
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int flag;
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{
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struct snoop *snp = dev->si_drv1;
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int len, n, nblen, s, error = 0;
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caddr_t from;
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char *nbuf;
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KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen,
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("snoop buffer error"));
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if (snp->snp_tty == NULL)
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return (EIO);
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snp->snp_flags &= ~SNOOP_RWAIT;
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do {
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if (snp->snp_len == 0) {
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if (flag & IO_NDELAY)
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return (EWOULDBLOCK);
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snp->snp_flags |= SNOOP_RWAIT;
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tsleep((caddr_t)snp, (PZERO + 1) | PCATCH, "snprd", 0);
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}
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} while (snp->snp_len == 0);
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n = snp->snp_len;
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while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) {
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len = MIN(uio->uio_resid, snp->snp_len);
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from = (caddr_t)(snp->snp_buf + snp->snp_base);
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if (len == 0)
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break;
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error = uiomove(from, len, uio);
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snp->snp_base += len;
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snp->snp_len -= len;
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}
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if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) {
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snp->snp_flags &= ~SNOOP_OFLOW;
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}
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s = spltty();
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nblen = snp->snp_blen;
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if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) {
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while (((nblen / 2) >= snp->snp_len) && ((nblen / 2) >= SNOOP_MINLEN))
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nblen = nblen / 2;
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if ((nbuf = malloc(nblen, M_SNP, M_NOWAIT)) != NULL) {
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bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
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free(snp->snp_buf, M_SNP);
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snp->snp_buf = nbuf;
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snp->snp_blen = nblen;
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snp->snp_base = 0;
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}
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}
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splx(s);
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return error;
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}
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int
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snpinc(struct snoop *snp, char c)
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{
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char buf;
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buf = c;
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return (snpin(snp, &buf, 1));
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}
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int
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snpin(snp, buf, n)
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struct snoop *snp;
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char *buf;
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int n;
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{
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int s_free, s_tail;
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int s, len, nblen;
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caddr_t from, to;
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char *nbuf;
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KASSERT(n >= 0, ("negative snoop char count"));
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if (n == 0)
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return 0;
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if (snp->snp_flags & SNOOP_DOWN) {
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printf("Snoop: more data to down interface.\n");
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return 0;
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}
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if (snp->snp_flags & SNOOP_OFLOW) {
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printf("Snoop: buffer overflow.\n");
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/*
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* On overflow we just repeat the standart close
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* procedure...yes , this is waste of space but.. Then next
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* read from device will fail if one would recall he is
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* snooping and retry...
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*/
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return (snpdown(snp));
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}
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s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base);
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s_free = snp->snp_blen - snp->snp_len;
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if (n > s_free) {
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s = spltty();
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nblen = snp->snp_blen;
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while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) {
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nblen = snp->snp_blen * 2;
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s_free = nblen - (snp->snp_len + snp->snp_base);
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}
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if ((n <= s_free) && (nbuf = malloc(nblen, M_SNP, M_NOWAIT))) {
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bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
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free(snp->snp_buf, M_SNP);
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snp->snp_buf = nbuf;
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snp->snp_blen = nblen;
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snp->snp_base = 0;
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} else {
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snp->snp_flags |= SNOOP_OFLOW;
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if (snp->snp_flags & SNOOP_RWAIT) {
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snp->snp_flags &= ~SNOOP_RWAIT;
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wakeup((caddr_t)snp);
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}
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splx(s);
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return 0;
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}
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splx(s);
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}
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if (n > s_tail) {
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from = (caddr_t)(snp->snp_buf + snp->snp_base);
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to = (caddr_t)(snp->snp_buf);
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len = snp->snp_len;
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bcopy(from, to, len);
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snp->snp_base = 0;
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}
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to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len);
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bcopy(buf, to, n);
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snp->snp_len += n;
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if (snp->snp_flags & SNOOP_RWAIT) {
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snp->snp_flags &= ~SNOOP_RWAIT;
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wakeup((caddr_t)snp);
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}
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selwakeup(&snp->snp_sel);
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snp->snp_sel.si_pid = 0;
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return n;
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}
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static int
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snpopen(dev, flag, mode, p)
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dev_t dev;
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int flag, mode;
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struct proc *p;
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{
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struct snoop *snp;
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int error;
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if ((error = suser(p)) != 0)
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return (error);
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if (dev->si_drv1 == NULL) {
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if (!(dev->si_flags & SI_NAMED))
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make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
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0600, "snp%d", dev2unit(dev));
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dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP, M_WAITOK|M_ZERO);
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} else
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return (EBUSY);
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/*
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* We intentionally do not OR flags with SNOOP_OPEN, but set them so
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* all previous settings (especially SNOOP_OFLOW) will be cleared.
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*/
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snp->snp_flags = SNOOP_OPEN;
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snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
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snp->snp_blen = SNOOP_MINLEN;
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snp->snp_base = 0;
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snp->snp_len = 0;
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/*
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* snp_tty == NULL is for inactive snoop devices.
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*/
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snp->snp_tty = NULL;
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snp->snp_target = NODEV;
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return (0);
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}
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static int
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snp_detach(snp)
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struct snoop *snp;
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{
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struct tty *tp;
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snp->snp_base = 0;
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snp->snp_len = 0;
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/*
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* If line disc. changed we do not touch this pointer, SLIP/PPP will
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* change it anyway.
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*/
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if (snp->snp_tty == NULL)
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goto detach_notty;
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tp = snp->snp_tty;
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if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
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tp->t_line == mylinedisc) {
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tp->t_sc = NULL;
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tp->t_state &= ~TS_SNOOP;
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tp->t_line = snp->snp_olddisc;
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} else
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printf("Snoop: bad attached tty data.\n");
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snp->snp_tty = NULL;
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snp->snp_target = NODEV;
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detach_notty:
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selwakeup(&snp->snp_sel);
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snp->snp_sel.si_pid = 0;
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if ((snp->snp_flags & SNOOP_OPEN) == 0)
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free(snp, M_SNP);
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return (0);
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}
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static int
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snpclose(dev, flags, fmt, p)
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dev_t dev;
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int flags;
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int fmt;
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struct proc *p;
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{
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struct snoop *snp = dev->si_drv1;
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snp->snp_blen = 0;
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free(snp->snp_buf, M_SNP);
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snp->snp_flags &= ~SNOOP_OPEN;
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dev->si_drv1 = NULL;
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destroy_dev(dev);
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return (snp_detach(snp));
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}
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int
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snpdown(snp)
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struct snoop *snp;
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{
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if (snp->snp_blen != SNOOP_MINLEN) {
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free(snp->snp_buf, M_SNP);
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snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
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snp->snp_blen = SNOOP_MINLEN;
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}
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snp->snp_flags |= SNOOP_DOWN;
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return (snp_detach(snp));
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}
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static int
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snpioctl(dev, cmd, data, flags, p)
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dev_t dev;
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u_long cmd;
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caddr_t data;
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int flags;
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struct proc *p;
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{
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dev_t tdev;
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struct snoop *snp = dev->si_drv1;
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struct tty *tp, *tpo;
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int s;
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switch (cmd) {
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case SNPSTTY:
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tdev = udev2dev(*((udev_t *)data), 0);
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if (tdev == NODEV)
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return (snpdown(snp));
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tp = snpdevtotty(tdev);
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if (!tp)
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return (EINVAL);
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s = spltty();
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if (snp->snp_target == NODEV) {
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tpo = snp->snp_tty;
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if (tpo)
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tpo->t_state &= ~TS_SNOOP;
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}
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tp->t_sc = (caddr_t)snp;
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tp->t_state |= TS_SNOOP;
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snp->snp_olddisc = tp->t_line;
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tp->t_line = mylinedisc;
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snp->snp_tty = tp;
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snp->snp_target = tdev;
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/*
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* Clean overflow and down flags -
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* we'll have a chance to get them in the future :)))
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*/
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snp->snp_flags &= ~SNOOP_OFLOW;
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snp->snp_flags &= ~SNOOP_DOWN;
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splx(s);
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break;
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case SNPGTTY:
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/*
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* We keep snp_target field specially to make
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* SNPGTTY happy, else we can't know what is device
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* major/minor for tty.
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*/
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*((dev_t *)data) = snp->snp_target;
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break;
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case FIONBIO:
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break;
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case FIOASYNC:
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if (*(int *)data)
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snp->snp_flags |= SNOOP_ASYNC;
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else
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snp->snp_flags &= ~SNOOP_ASYNC;
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break;
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case FIONREAD:
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s = spltty();
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if (snp->snp_tty != NULL)
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*(int *)data = snp->snp_len;
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else
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if (snp->snp_flags & SNOOP_DOWN) {
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if (snp->snp_flags & SNOOP_OFLOW)
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*(int *)data = SNP_OFLOW;
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else
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*(int *)data = SNP_TTYCLOSE;
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} else {
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*(int *)data = SNP_DETACH;
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}
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|
splx(s);
|
|
break;
|
|
|
|
default:
|
|
return (ENOTTY);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
|
|
static int
|
|
snppoll(dev, events, p)
|
|
dev_t dev;
|
|
int events;
|
|
struct proc *p;
|
|
{
|
|
struct snoop *snp = dev->si_drv1;
|
|
int revents = 0;
|
|
|
|
|
|
/*
|
|
* If snoop is down, we don't want to poll() forever so we return 1.
|
|
* Caller should see if we down via FIONREAD ioctl(). The last should
|
|
* return -1 to indicate down state.
|
|
*/
|
|
if (events & (POLLIN | POLLRDNORM)) {
|
|
if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0)
|
|
revents |= events & (POLLIN | POLLRDNORM);
|
|
else
|
|
selrecord(p, &snp->snp_sel);
|
|
}
|
|
return (revents);
|
|
}
|
|
|
|
static void
|
|
snp_clone(void *arg, char *name, int namelen, dev_t *dev)
|
|
{
|
|
int u;
|
|
|
|
if (*dev != NODEV)
|
|
return;
|
|
if (dev_stdclone(name, NULL, "snp", &u) != 1)
|
|
return;
|
|
*dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
|
|
"snp%d", u);
|
|
return;
|
|
}
|
|
|
|
static int
|
|
snp_modevent(module_t mod, int type, void *data)
|
|
{
|
|
static eventhandler_tag eh_tag = NULL;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
eh_tag = EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000);
|
|
mylinedisc = ldisc_register(LDISC_LOAD, &snpdisc);
|
|
cdevsw_add(&snp_cdevsw);
|
|
break;
|
|
case MOD_UNLOAD:
|
|
EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
|
|
ldisc_deregister(mylinedisc);
|
|
cdevsw_remove(&snp_cdevsw);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static moduledata_t snp_mod = {
|
|
"snp",
|
|
snp_modevent,
|
|
NULL
|
|
};
|
|
DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR);
|