| 1 | /* $NetBSD: tty_tty.c,v 1.40 2014/07/25 08:10:40 dholland Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1982, 1986, 1991, 1993, 1995 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * 3. Neither the name of the University nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | * SUCH DAMAGE. |
| 30 | * |
| 31 | * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 |
| 32 | */ |
| 33 | |
| 34 | /* |
| 35 | * Indirect driver for controlling tty. |
| 36 | */ |
| 37 | |
| 38 | #include <sys/cdefs.h> |
| 39 | __KERNEL_RCSID(0, "$NetBSD: tty_tty.c,v 1.40 2014/07/25 08:10:40 dholland Exp $" ); |
| 40 | |
| 41 | #include <sys/param.h> |
| 42 | #include <sys/systm.h> |
| 43 | #include <sys/ioctl.h> |
| 44 | #include <sys/proc.h> |
| 45 | #include <sys/tty.h> |
| 46 | #include <sys/vnode.h> |
| 47 | #include <sys/file.h> |
| 48 | #include <sys/conf.h> |
| 49 | #include <sys/kauth.h> |
| 50 | |
| 51 | /* XXXSMP */ |
| 52 | #define cttyvp(p) ((p)->p_lflag & PL_CONTROLT ? (p)->p_session->s_ttyvp : NULL) |
| 53 | |
| 54 | /*ARGSUSED*/ |
| 55 | static int |
| 56 | cttyopen(dev_t dev, int flag, int mode, struct lwp *l) |
| 57 | { |
| 58 | struct vnode *ttyvp = cttyvp(l->l_proc); |
| 59 | int error; |
| 60 | |
| 61 | if (ttyvp == NULL) |
| 62 | return (ENXIO); |
| 63 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
| 64 | #ifdef PARANOID |
| 65 | /* |
| 66 | * Since group is tty and mode is 620 on most terminal lines |
| 67 | * and since sessions protect terminals from processes outside |
| 68 | * your session, this check is probably no longer necessary. |
| 69 | * Since it inhibits setuid root programs that later switch |
| 70 | * to another user from accessing /dev/tty, we have decided |
| 71 | * to delete this test. (mckusick 5/93) |
| 72 | */ |
| 73 | error = VOP_ACCESS(ttyvp, |
| 74 | (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), l->l_cred, l); |
| 75 | if (!error) |
| 76 | #endif /* PARANOID */ |
| 77 | error = VOP_OPEN(ttyvp, flag, NOCRED); |
| 78 | VOP_UNLOCK(ttyvp); |
| 79 | return (error); |
| 80 | } |
| 81 | |
| 82 | /*ARGSUSED*/ |
| 83 | static int |
| 84 | cttyread(dev_t dev, struct uio *uio, int flag) |
| 85 | { |
| 86 | struct vnode *ttyvp = cttyvp(curproc); |
| 87 | int error; |
| 88 | |
| 89 | if (ttyvp == NULL) |
| 90 | return (EIO); |
| 91 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
| 92 | error = VOP_READ(ttyvp, uio, flag, NOCRED); |
| 93 | VOP_UNLOCK(ttyvp); |
| 94 | return (error); |
| 95 | } |
| 96 | |
| 97 | /*ARGSUSED*/ |
| 98 | static int |
| 99 | cttywrite(dev_t dev, struct uio *uio, int flag) |
| 100 | { |
| 101 | struct vnode *ttyvp = cttyvp(curproc); |
| 102 | int error; |
| 103 | |
| 104 | if (ttyvp == NULL) |
| 105 | return (EIO); |
| 106 | vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); |
| 107 | error = VOP_WRITE(ttyvp, uio, flag, NOCRED); |
| 108 | VOP_UNLOCK(ttyvp); |
| 109 | return (error); |
| 110 | } |
| 111 | |
| 112 | /*ARGSUSED*/ |
| 113 | static int |
| 114 | cttyioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l) |
| 115 | { |
| 116 | struct vnode *ttyvp = cttyvp(l->l_proc); |
| 117 | int rv; |
| 118 | |
| 119 | if (ttyvp == NULL) |
| 120 | return (EIO); |
| 121 | if (cmd == TIOCSCTTY) /* XXX */ |
| 122 | return (EINVAL); |
| 123 | if (cmd == TIOCNOTTY) { |
| 124 | mutex_enter(proc_lock); |
| 125 | if (!SESS_LEADER(l->l_proc)) { |
| 126 | l->l_proc->p_lflag &= ~PL_CONTROLT; |
| 127 | rv = 0; |
| 128 | } else |
| 129 | rv = EINVAL; |
| 130 | mutex_exit(proc_lock); |
| 131 | return (rv); |
| 132 | } |
| 133 | return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED)); |
| 134 | } |
| 135 | |
| 136 | /*ARGSUSED*/ |
| 137 | static int |
| 138 | cttypoll(dev_t dev, int events, struct lwp *l) |
| 139 | { |
| 140 | struct vnode *ttyvp = cttyvp(l->l_proc); |
| 141 | |
| 142 | if (ttyvp == NULL) |
| 143 | return (seltrue(dev, events, l)); |
| 144 | return (VOP_POLL(ttyvp, events)); |
| 145 | } |
| 146 | |
| 147 | static int |
| 148 | cttykqfilter(dev_t dev, struct knote *kn) |
| 149 | { |
| 150 | /* This is called from filt_fileattach() by the attaching process. */ |
| 151 | struct proc *p = curproc; |
| 152 | struct vnode *ttyvp = cttyvp(p); |
| 153 | |
| 154 | if (ttyvp == NULL) |
| 155 | return (1); |
| 156 | return (VOP_KQFILTER(ttyvp, kn)); |
| 157 | } |
| 158 | |
| 159 | const struct cdevsw ctty_cdevsw = { |
| 160 | .d_open = cttyopen, |
| 161 | .d_close = nullclose, |
| 162 | .d_read = cttyread, |
| 163 | .d_write = cttywrite, |
| 164 | .d_ioctl = cttyioctl, |
| 165 | .d_stop = nullstop, |
| 166 | .d_tty = notty, |
| 167 | .d_poll = cttypoll, |
| 168 | .d_mmap = nommap, |
| 169 | .d_kqfilter = cttykqfilter, |
| 170 | .d_discard = nodiscard, |
| 171 | .d_flag = D_TTY |
| 172 | }; |
| 173 | |