1/* 2 * Copyright (c) 1997-2012 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/*- 29 * Copyright (c) 1982, 1986, 1991, 1993 30 * The Regents of the University of California. All rights reserved. 31 * 32 * Redistribution and use in source and binary forms, with or without 33 * modification, are permitted provided that the following conditions 34 * are met: 35 * 1. Redistributions of source code must retain the above copyright 36 * notice, this list of conditions and the following disclaimer. 37 * 2. Redistributions in binary form must reproduce the above copyright 38 * notice, this list of conditions and the following disclaimer in the 39 * documentation and/or other materials provided with the distribution. 40 * 3. All advertising materials mentioning features or use of this software 41 * must display the following acknowledgement: 42 * This product includes software developed by the University of 43 * California, Berkeley and its contributors. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 61 */ 62 63/* 64 * Indirect driver for controlling tty. 65 */ 66#include <sys/param.h> 67#include <sys/systm.h> 68#include <sys/conf.h> 69#include <sys/ioctl.h> 70#include <sys/proc_internal.h> 71#include <sys/tty.h> 72#include <sys/vnode_internal.h> 73#include <sys/file_internal.h> 74#include <sys/kauth.h> 75 76/* Forward declarations for cdevsw[] entry */ 77/* XXX we should consider making these static */ 78int cttyopen(dev_t dev, int flag, int mode, proc_t p); 79int cttyclose(dev_t dev, int flag, int mode, proc_t p); 80int cttyread(dev_t dev, struct uio *uio, int flag); 81int cttywrite(dev_t dev, struct uio *uio, int flag); 82int cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p); 83int cttyselect(dev_t dev, int flag, void* wql, proc_t p); 84static vnode_t cttyvp(proc_t p); 85 86int 87cttyopen(dev_t dev, int flag, __unused int mode, proc_t p) 88{ 89 vnode_t ttyvp; 90 int error; 91 92 /* 93 * A little hack--this device, used by many processes, 94 * does an open on another device, which can cause unhappiness 95 * if the second-level open blocks indefinitely (e.g. if the 96 * master side has hung up). This driver doesn't care 97 * about serializing opens and closes, so drop the lock. 98 */ 99 devsw_unlock(dev, S_IFCHR); 100 101 if ((ttyvp = cttyvp(p)) == NULL) { 102 error = ENXIO; 103 } else { 104 struct vfs_context context; 105 106 context.vc_thread = current_thread(); 107 context.vc_ucred = kauth_cred_proc_ref(p); 108 109 error = VNOP_OPEN(ttyvp, flag, &context); 110 111 kauth_cred_unref(&context.vc_ucred); 112 vnode_put(ttyvp); 113 } 114 115 devsw_lock(dev, S_IFCHR); 116 return (error); 117} 118 119/* 120 * This driver is marked D_TRACKCLOSE and so gets a close 121 * for every open so that ttyvp->v_specinfo->si_count can be kept sane. 122 */ 123int 124cttyclose(dev_t dev, int flag, __unused int mode, proc_t p) 125{ 126 vnode_t ttyvp; 127 int error; 128 129 /* See locking commentary above. */ 130 131 devsw_unlock(dev, S_IFCHR); 132 133 if ((ttyvp = cttyvp(p)) == NULL) { 134 error = ENXIO; 135 } else { 136 struct vfs_context context; 137 138 context.vc_thread = current_thread(); 139 context.vc_ucred = kauth_cred_proc_ref(p); 140 141 error = VNOP_CLOSE(ttyvp, flag, &context); 142 143 kauth_cred_unref(&context.vc_ucred); 144 vnode_put(ttyvp); 145 } 146 147 devsw_lock(dev, S_IFCHR); 148 return (error); 149} 150 151int 152cttyread(__unused dev_t dev, struct uio *uio, int flag) 153{ 154 vnode_t ttyvp = cttyvp(current_proc()); 155 struct vfs_context context; 156 int error; 157 158 if (ttyvp == NULL) 159 return (EIO); 160 161 context.vc_thread = current_thread(); 162 context.vc_ucred = NOCRED; 163 164 error = VNOP_READ(ttyvp, uio, flag, &context); 165 vnode_put(ttyvp); 166 167 return (error); 168} 169 170int 171cttywrite(__unused dev_t dev, struct uio *uio, int flag) 172{ 173 vnode_t ttyvp = cttyvp(current_proc()); 174 struct vfs_context context; 175 int error; 176 177 if (ttyvp == NULL) 178 return (EIO); 179 180 context.vc_thread = current_thread(); 181 context.vc_ucred = NOCRED; 182 183 error = VNOP_WRITE(ttyvp, uio, flag, &context); 184 vnode_put(ttyvp); 185 186 return (error); 187} 188 189int 190cttyioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p) 191{ 192 vnode_t ttyvp = cttyvp(current_proc()); 193 struct vfs_context context; 194 struct session *sessp; 195 int error = 0; 196 197 if (ttyvp == NULL) 198 return (EIO); 199 if (cmd == TIOCSCTTY) { /* don't allow controlling tty to be set */ 200 error = EINVAL; /* to controlling tty -- infinite recursion */ 201 goto out; 202 } 203 if (cmd == TIOCNOTTY) { 204 sessp = proc_session(p); 205 if (!SESS_LEADER(p, sessp)) { 206 OSBitAndAtomic(~((uint32_t)P_CONTROLT), &p->p_flag); 207 if (sessp != SESSION_NULL) 208 session_rele(sessp); 209 error = 0; 210 goto out; 211 } else { 212 if (sessp != SESSION_NULL) 213 session_rele(sessp); 214 error = EINVAL; 215 goto out; 216 } 217 } 218 context.vc_thread = current_thread(); 219 context.vc_ucred = NOCRED; 220 221 error = VNOP_IOCTL(ttyvp, cmd, addr, flag, &context); 222out: 223 vnode_put(ttyvp); 224 return (error); 225} 226 227int 228cttyselect(__unused dev_t dev, int flag, void* wql, __unused proc_t p) 229{ 230 vnode_t ttyvp = cttyvp(current_proc()); 231 struct vfs_context context; 232 int error; 233 234 context.vc_thread = current_thread(); 235 context.vc_ucred = NOCRED; 236 237 if (ttyvp == NULL) 238 return (1); /* try operation to get EOF/failure */ 239 error = VNOP_SELECT(ttyvp, flag, FREAD|FWRITE, wql, &context); 240 vnode_put(ttyvp); 241 return (error); 242} 243 244/* This returns vnode with ioref */ 245static vnode_t 246cttyvp(proc_t p) 247{ 248 vnode_t vp; 249 int vid; 250 struct session *sessp; 251 252 sessp = proc_session(p); 253 254 session_lock(sessp); 255 vp = (p->p_flag & P_CONTROLT ? sessp->s_ttyvp : NULLVP); 256 vid = sessp->s_ttyvid; 257 session_unlock(sessp); 258 259 session_rele(sessp); 260 261 if (vp != NULLVP) { 262 /* cannot get an IO reference, return NULLVP */ 263 if (vnode_getwithvid(vp, vid) != 0) 264 vp = NULLVP; 265 } 266 return(vp); 267} 268 269