NetBSD/sys/kern/tty_bsdpty.c

166 lines
4.2 KiB
C

/* $NetBSD: tty_bsdpty.c,v 1.20 2014/04/04 18:11:58 christos Exp $ */
/*-
* Copyright (c) 2004 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c,v 1.20 2014/04/04 18:11:58 christos Exp $");
#include "opt_ptm.h"
#ifndef NO_DEV_PTM
#ifdef COMPAT_BSDPTY
/* bsd tty implementation for pty multiplexor driver /dev/ptm{,x} */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/lwp.h>
#include <sys/tty.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/signalvar.h>
#include <sys/filedesc.h>
#include <sys/conf.h>
#include <sys/poll.h>
#include <sys/pty.h>
#include <sys/kauth.h>
/*
* pts == /dev/tty[pqrs]?
* ptc == /dev/pty[pqrs]?
*/
/*
* All this hard-coding is really evil.
*/
#define TTY_GID 4
#define TTY_PERM (S_IRUSR|S_IWUSR|S_IWGRP)
#define TTY_TEMPLATE "/dev/XtyXX"
#define TTY_NAMESIZE sizeof(TTY_TEMPLATE)
#define TTY_LETTERS "pqrstuvwxyzPQRST"
#define TTY_OLD_SUFFIX "0123456789abcdef"
#define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
static int pty_makename(struct mount *, struct lwp *, char *, size_t, dev_t,
char);
static int pty_allocvp(struct mount *, struct lwp *, struct vnode **,
dev_t, char);
static void pty_getvattr(struct mount *, struct lwp *, struct vattr *);
static int pty__getmp(struct lwp *, struct mount **);
struct ptm_pty ptm_bsdpty = {
pty_allocvp,
pty_makename,
pty_getvattr,
pty__getmp,
};
static int
/*ARGSUSED*/
pty_makename(struct mount *mp, struct lwp *l, char *bf,
size_t bufsiz, dev_t dev, char c)
{
size_t nt;
dev_t minor = minor(dev);
const char *suffix;
if (bufsiz < TTY_NAMESIZE)
return EINVAL;
(void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE);
if (minor < 256) {
suffix = TTY_OLD_SUFFIX;
nt = sizeof(TTY_OLD_SUFFIX) - 1;
} else {
minor -= 256;
suffix = TTY_NEW_SUFFIX;
nt = sizeof(TTY_NEW_SUFFIX) - 1;
}
bf[5] = c;
bf[8] = TTY_LETTERS[minor / nt];
bf[9] = suffix[minor % nt];
return 0;
}
static int
/*ARGSUSED*/
pty_allocvp(struct mount *mp, struct lwp *l, struct vnode **vp, dev_t dev,
char ms)
{
int error;
struct pathbuf *pb;
struct nameidata nd;
char name[TTY_NAMESIZE];
error = pty_makename(NULL, l, name, sizeof(name), dev, ms);
if (error)
return error;
pb = pathbuf_create(name);
if (pb == NULL) {
return ENOMEM;
}
NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, pb);
if ((error = namei(&nd)) != 0) {
pathbuf_destroy(pb);
return error;
}
*vp = nd.ni_vp;
pathbuf_destroy(pb);
return 0;
}
static void
/*ARGSUSED*/
pty_getvattr(struct mount *mp, struct lwp *l, struct vattr *vattr)
{
vattr_null(vattr);
/* get real uid */
vattr->va_uid = kauth_cred_getuid(l->l_cred);
vattr->va_gid = TTY_GID;
vattr->va_mode = TTY_PERM;
}
static int
pty__getmp(struct lwp *l __unused, struct mount **mpp)
{
*mpp = 0;
return 0;
}
#endif /* COMPAT_BSDPTY */
#endif /* NO_DEV_PTM */