6a113b3de7
event handler, dev_clone, which accepts a credential argument. Implementors of the event can ignore it if they're not interested, and most do. This avoids having multiple event handler types and fall-back/precedence logic in devfs. This changes the kernel API for /dev cloning, and may affect third party packages containg cloning kernel modules. Requested by: phk MFC after: 3 days
463 lines
10 KiB
C
463 lines
10 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. 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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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* Pseudo-nulmodem driver
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* Mighty handy for use with serial console in Vmware
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*/
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#include "opt_compat.h"
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#include "opt_tty.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/tty.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/poll.h>
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#include <sys/kernel.h>
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#include <sys/module.h>
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#include <sys/serial.h>
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#include <sys/signalvar.h>
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#include <sys/malloc.h>
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#include <sys/taskqueue.h>
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MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
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static d_close_t nmdmclose;
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static t_modem_t nmdmmodem;
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static d_open_t nmdmopen;
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static t_oproc_t nmdmoproc;
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static t_param_t nmdmparam;
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static t_stop_t nmdmstop;
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static void nmdminit(struct cdev *dev);
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static struct cdevsw nmdm_cdevsw = {
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.d_version = D_VERSION,
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.d_open = nmdmopen,
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.d_close = nmdmclose,
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.d_name = "nmdn",
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.d_flags = D_TTY | D_PSEUDO | D_NEEDGIANT,
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};
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#define BUFSIZ 100 /* Chunk size iomoved to/from user */
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#define NMDM_MAX_NUM 128 /* Artificially limit # devices. */
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#define PF_STOPPED 0x10 /* user told stopped */
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#define BFLAG CLONE_FLAG0
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struct softpart {
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struct tty *nm_tty;
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struct cdev *dev;
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int nm_dcd;
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struct task pt_task;
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struct softpart *other;
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struct callout co;
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u_long quota;
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u_long accumulator;
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int rate;
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int credits;
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#define QS 8 /* Quota shift */
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};
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struct nm_softc {
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TAILQ_ENTRY(nm_softc) pt_list;
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int pt_flags;
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struct softpart part1, part2;
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struct prison *pt_prison;
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};
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static struct clonedevs *nmdmclones;
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static TAILQ_HEAD(,nm_softc) nmdmhead = TAILQ_HEAD_INITIALIZER(nmdmhead);
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static void
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nmdm_clone(void *arg, struct ucred *cred, char *name, int nameen,
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struct cdev **dev)
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{
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int i, unit;
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char *p;
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struct cdev *d1, *d2;
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if (*dev != NULL)
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return;
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if (strcmp(name, "nmdm") == 0) {
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p = NULL;
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unit = -1;
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} else {
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i = dev_stdclone(name, &p, "nmdm", &unit);
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if (i == 0)
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return;
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if (p[0] != '\0' && p[0] != 'A' && p[0] != 'B')
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return;
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else if (p[0] != '\0' && p[1] != '\0')
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return;
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}
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i = clone_create(&nmdmclones, &nmdm_cdevsw, &unit, &d1, 0);
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if (i) {
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d1 = make_dev(&nmdm_cdevsw, unit2minor(unit),
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0, 0, 0666, "nmdm%dA", unit);
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if (d1 == NULL)
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return;
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d2 = make_dev(&nmdm_cdevsw, unit2minor(unit) | BFLAG,
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0, 0, 0666, "nmdm%dB", unit);
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if (d2 == NULL) {
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destroy_dev(d1);
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return;
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}
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d2->si_drv2 = d1;
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d1->si_drv2 = d2;
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dev_depends(d1, d2);
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dev_depends(d2, d1);
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d1->si_flags |= SI_CHEAPCLONE;
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d2->si_flags |= SI_CHEAPCLONE;
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}
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if (p != NULL && p[0] == 'B')
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*dev = d1->si_drv2;
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else
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*dev = d1;
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dev_ref(*dev);
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}
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static void
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nmdm_timeout(void *arg)
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{
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struct softpart *sp;
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sp = arg;
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if (sp->rate == 0)
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return;
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/*
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* Do a simple Floyd-Steinberg dither here to avoid FP math.
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* Wipe out unused quota from last tick.
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*/
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sp->accumulator += sp->credits;
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sp->quota = sp->accumulator >> QS;
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sp->accumulator &= ((1 << QS) - 1);
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taskqueue_enqueue(taskqueue_swi_giant, &sp->pt_task);
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callout_reset(&sp->co, sp->rate, nmdm_timeout, arg);
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}
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static void
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nmdm_task_tty(void *arg, int pending __unused)
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{
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struct tty *tp, *otp;
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struct softpart *sp;
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int c;
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tp = arg;
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sp = tp->t_sc;
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otp = sp->other->nm_tty;
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KASSERT(otp != NULL, ("NULL otp in nmdmstart"));
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KASSERT(otp != tp, ("NULL otp == tp nmdmstart"));
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if (sp->other->nm_dcd) {
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if (!(tp->t_state & TS_ISOPEN)) {
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sp->other->nm_dcd = 0;
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(void)ttyld_modem(otp, 0);
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}
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} else {
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if (tp->t_state & TS_ISOPEN) {
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sp->other->nm_dcd = 1;
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(void)ttyld_modem(otp, 1);
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}
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}
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if (tp->t_state & TS_TTSTOP)
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return;
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while (tp->t_outq.c_cc != 0) {
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if (sp->rate && !sp->quota)
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return;
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if (otp->t_state & TS_TBLOCK)
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return;
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sp->quota--;
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c = getc(&tp->t_outq);
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if (otp->t_state & TS_ISOPEN)
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ttyld_rint(otp, c);
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}
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if (tp->t_outq.c_cc == 0)
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ttwwakeup(tp);
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}
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/*
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* This function creates and initializes a pair of ttys.
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*/
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static void
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nmdminit(struct cdev *dev1)
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{
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struct cdev *dev2;
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struct nm_softc *pt;
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dev2 = dev1->si_drv2;
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dev1->si_flags &= ~SI_CHEAPCLONE;
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dev2->si_flags &= ~SI_CHEAPCLONE;
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pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK | M_ZERO);
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TAILQ_INSERT_TAIL(&nmdmhead, pt, pt_list);
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dev1->si_drv1 = dev2->si_drv1 = pt;
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pt->part1.dev = dev1;
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pt->part2.dev = dev2;
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pt->part1.nm_tty = ttymalloc(pt->part1.nm_tty);
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pt->part1.nm_tty->t_oproc = nmdmoproc;
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pt->part1.nm_tty->t_stop = nmdmstop;
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pt->part1.nm_tty->t_modem = nmdmmodem;
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pt->part1.nm_tty->t_param = nmdmparam;
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pt->part1.nm_tty->t_dev = dev1;
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pt->part1.nm_tty->t_sc = &pt->part1;
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TASK_INIT(&pt->part1.pt_task, 0, nmdm_task_tty, pt->part1.nm_tty);
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callout_init(&pt->part1.co, 0);
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pt->part2.nm_tty = ttymalloc(pt->part2.nm_tty);
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pt->part2.nm_tty->t_oproc = nmdmoproc;
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pt->part2.nm_tty->t_stop = nmdmstop;
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pt->part2.nm_tty->t_modem = nmdmmodem;
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pt->part2.nm_tty->t_param = nmdmparam;
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pt->part2.nm_tty->t_dev = dev2;
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pt->part2.nm_tty->t_sc = &pt->part2;
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TASK_INIT(&pt->part2.pt_task, 0, nmdm_task_tty, pt->part2.nm_tty);
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callout_init(&pt->part2.co, 0);
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pt->part1.other = &pt->part2;
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pt->part2.other = &pt->part1;
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dev1->si_tty = pt->part1.nm_tty;
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dev1->si_drv1 = pt;
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dev2->si_tty = pt->part2.nm_tty;
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dev2->si_drv1 = pt;
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}
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/*
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* Device opened from userland
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*/
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static int
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nmdmopen(struct cdev *dev, int flag, int devtype, struct thread *td)
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{
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struct tty *tp, *tp2;
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int error;
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struct nm_softc *pti;
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struct softpart *sp;
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if (dev->si_drv1 == NULL)
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nmdminit(dev);
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pti = dev->si_drv1;
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if (pti->pt_prison != td->td_ucred->cr_prison)
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return (EBUSY);
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tp = dev->si_tty;
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sp = tp->t_sc;
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tp2 = sp->other->nm_tty;
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if ((tp->t_state & TS_ISOPEN) == 0) {
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ttyinitmode(tp, 0, 0);
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ttsetwater(tp); /* XXX ? */
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} else if (tp->t_state & TS_XCLUDE && suser(td)) {
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return (EBUSY);
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}
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error = ttyld_open(tp, dev);
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return (error);
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}
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static int
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bits_per_char(struct termios *t)
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{
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int bits;
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bits = 1; /* start bit */
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switch (t->c_cflag & CSIZE) {
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case CS5: bits += 5; break;
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case CS6: bits += 6; break;
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case CS7: bits += 7; break;
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case CS8: bits += 8; break;
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}
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bits++; /* stop bit */
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if (t->c_cflag & PARENB)
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bits++;
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if (t->c_cflag & CSTOPB)
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bits++;
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return (bits);
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}
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static int
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nmdmparam(struct tty *tp, struct termios *t)
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{
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struct softpart *sp;
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struct tty *tp2;
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int bpc, rate, speed, i;
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sp = tp->t_sc;
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tp2 = sp->other->nm_tty;
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if (!((t->c_cflag | tp2->t_cflag) & CDSR_OFLOW)) {
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sp->rate = 0;
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sp->other->rate = 0;
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return (0);
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}
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/*
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* DSRFLOW one either side enables rate-simulation for both
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* directions.
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* NB: the two directions may run at different rates.
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*/
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/* Find the larger of the number of bits transmitted */
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bpc = imax(bits_per_char(t), bits_per_char(&tp2->t_termios));
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for (i = 0; i < 2; i++) {
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/* Use the slower of our receive and their transmit rate */
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speed = imin(tp2->t_ospeed, t->c_ispeed);
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if (speed == 0) {
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sp->rate = 0;
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sp->other->rate = 0;
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return (0);
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}
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speed <<= QS; /* [bit/sec, scaled] */
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speed /= bpc; /* [char/sec, scaled] */
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rate = (hz << QS) / speed; /* [hz per callout] */
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if (rate == 0)
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rate = 1;
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speed *= rate;
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speed /= hz; /* [(char/sec)/tick, scaled */
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sp->credits = speed;
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sp->rate = rate;
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callout_reset(&sp->co, rate, nmdm_timeout, sp);
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/*
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* swap pointers for second pass so the other end gets
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* updated as well.
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*/
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sp = sp->other;
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t = &tp2->t_termios;
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tp2 = 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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nmdmmodem(struct tty *tp, int sigon, int sigoff)
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{
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struct softpart *sp;
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int i;
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sp = tp->t_sc;
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if (sigon || sigoff) {
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if (sigon & SER_DTR)
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sp->other->nm_dcd = 1;
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if (sigoff & SER_DTR)
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sp->other->nm_dcd = 0;
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ttyld_modem(sp->other->nm_tty, sp->other->nm_dcd);
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return (0);
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} else {
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i = 0;
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if (sp->nm_dcd)
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i |= SER_DCD;
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if (sp->other->nm_dcd)
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i |= SER_DTR;
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return (i);
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}
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}
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static int
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nmdmclose(struct cdev *dev, int flag, int mode, struct thread *td)
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{
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return (tty_close(dev->si_tty));
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}
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static void
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nmdmoproc(struct tty *tp)
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{
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struct softpart *pt;
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pt = tp->t_sc;
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taskqueue_enqueue(taskqueue_swi_giant, &pt->pt_task);
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}
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static void
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nmdmstop(struct tty *tp, int flush)
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{
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struct softpart *pt;
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pt = tp->t_sc;
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taskqueue_enqueue(taskqueue_swi_giant, &pt->pt_task);
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}
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/*
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* Module handling
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*/
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static int
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nmdm_modevent(module_t mod, int type, void *data)
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{
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static eventhandler_tag tag;
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struct nm_softc *pt, *tpt;
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int error = 0;
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switch(type) {
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case MOD_LOAD:
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clone_setup(&nmdmclones);
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tag = EVENTHANDLER_REGISTER(dev_clone, nmdm_clone, 0, 1000);
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if (tag == NULL)
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return (ENOMEM);
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break;
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case MOD_SHUTDOWN:
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/* FALLTHROUGH */
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case MOD_UNLOAD:
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EVENTHANDLER_DEREGISTER(dev_clone, tag);
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TAILQ_FOREACH_SAFE(pt, &nmdmhead, pt_list, tpt) {
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destroy_dev(pt->part1.dev);
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TAILQ_REMOVE(&nmdmhead, pt, pt_list);
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free(pt, M_NLMDM);
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}
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clone_cleanup(&nmdmclones);
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break;
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default:
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error = EOPNOTSUPP;
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}
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return (error);
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}
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DEV_MODULE(nmdm, nmdm_modevent, NULL);
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