1 /* $NetBSD: tty_bsdpty.c,v 1.9 2006/07/23 22:06:11 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2004 The NetBSD Foundation, Inc. 5 * 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the NetBSD 18 * Foundation, Inc. and its contributors. 19 * 4. Neither the name of The NetBSD Foundation nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c,v 1.9 2006/07/23 22:06:11 ad Exp $"); 38 39 #include "opt_ptm.h" 40 41 #ifdef COMPAT_BSDPTY 42 /* bsd tty implementation for pty multiplexor driver /dev/ptm{,x} */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/ioctl.h> 47 #include <sys/lwp.h> 48 #include <sys/tty.h> 49 #include <sys/stat.h> 50 #include <sys/file.h> 51 #include <sys/uio.h> 52 #include <sys/kernel.h> 53 #include <sys/vnode.h> 54 #include <sys/namei.h> 55 #include <sys/signalvar.h> 56 #include <sys/uio.h> 57 #include <sys/filedesc.h> 58 #include <sys/conf.h> 59 #include <sys/poll.h> 60 #include <sys/malloc.h> 61 #include <sys/pty.h> 62 #include <sys/kauth.h> 63 64 /* 65 * pts == /dev/tty[pqrs]? 66 * ptc == /dev/pty[pqrs]? 67 */ 68 69 /* 70 * All this hard-coding is really evil. 71 */ 72 #define TTY_GID 4 73 #define TTY_PERM (S_IRUSR|S_IWUSR|S_IWGRP) 74 #define TTY_TEMPLATE "/dev/XtyXX" 75 #define TTY_NAMESIZE sizeof(TTY_TEMPLATE) 76 #define TTY_LETTERS "pqrstuvwxyzPQRST" 77 #define TTY_OLD_SUFFIX "0123456789abcdef" 78 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 79 80 static int pty_makename(struct ptm_pty *, struct lwp *, char *, size_t, dev_t, 81 char); 82 static int pty_allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 83 dev_t, char); 84 static void pty_getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 85 86 struct ptm_pty ptm_bsdpty = { 87 pty_allocvp, 88 pty_makename, 89 pty_getvattr, 90 NULL 91 }; 92 93 static int 94 /*ARGSUSED*/ 95 pty_makename(struct ptm_pty *ptm, struct lwp *l, char *bf, size_t bufsiz, 96 dev_t dev, char c) 97 { 98 size_t nt; 99 dev_t minor = minor(dev); 100 const char *suffix; 101 102 if (bufsiz < TTY_NAMESIZE) 103 return EINVAL; 104 105 (void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE); 106 107 if (minor < 256) { 108 suffix = TTY_OLD_SUFFIX; 109 nt = sizeof(TTY_OLD_SUFFIX) - 1; 110 } else { 111 minor -= 256; 112 suffix = TTY_NEW_SUFFIX; 113 nt = sizeof(TTY_NEW_SUFFIX) - 1; 114 } 115 116 bf[5] = c; 117 bf[8] = TTY_LETTERS[minor / nt]; 118 bf[9] = suffix[minor % nt]; 119 return 0; 120 } 121 122 123 static int 124 /*ARGSUSED*/ 125 pty_allocvp(struct ptm_pty *ptm, struct lwp *l, struct vnode **vp, dev_t dev, 126 char ms) 127 { 128 int error; 129 struct nameidata nd; 130 char name[TTY_NAMESIZE]; 131 132 error = (*ptm->makename)(ptm, l, name, sizeof(name), dev, ms); 133 if (error) 134 return error; 135 136 NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, UIO_SYSSPACE, name, l); 137 if ((error = namei(&nd)) != 0) 138 return error; 139 *vp = nd.ni_vp; 140 return 0; 141 } 142 143 144 static void 145 /*ARGSUSED*/ 146 pty_getvattr(struct ptm_pty *ptm, struct lwp *l, struct vattr *vattr) 147 { 148 VATTR_NULL(vattr); 149 /* get real uid */ 150 vattr->va_uid = kauth_cred_getuid(l->l_cred); 151 vattr->va_gid = TTY_GID; 152 vattr->va_mode = TTY_PERM; 153 } 154 #endif 155