1 /* $NetBSD: tty_bsdpty.c,v 1.13 2007/12/08 19:29:49 pooka 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 1.13 2007/12/08 19:29:49 pooka 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/filedesc.h> 57 #include <sys/conf.h> 58 #include <sys/poll.h> 59 #include <sys/malloc.h> 60 #include <sys/pty.h> 61 #include <sys/kauth.h> 62 63 /* 64 * pts == /dev/tty[pqrs]? 65 * ptc == /dev/pty[pqrs]? 66 */ 67 68 /* 69 * All this hard-coding is really evil. 70 */ 71 #define TTY_GID 4 72 #define TTY_PERM (S_IRUSR|S_IWUSR|S_IWGRP) 73 #define TTY_TEMPLATE "/dev/XtyXX" 74 #define TTY_NAMESIZE sizeof(TTY_TEMPLATE) 75 #define TTY_LETTERS "pqrstuvwxyzPQRST" 76 #define TTY_OLD_SUFFIX "0123456789abcdef" 77 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 78 79 static int pty_makename(struct ptm_pty *, struct lwp *, char *, size_t, dev_t, 80 char); 81 static int pty_allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 82 dev_t, char); 83 static void pty_getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 84 85 struct ptm_pty ptm_bsdpty = { 86 pty_allocvp, 87 pty_makename, 88 pty_getvattr, 89 NULL 90 }; 91 92 static int 93 /*ARGSUSED*/ 94 pty_makename(struct ptm_pty *ptm, struct lwp *l, char *bf, 95 size_t bufsiz, dev_t dev, char c) 96 { 97 size_t nt; 98 dev_t minor = minor(dev); 99 const char *suffix; 100 101 if (bufsiz < TTY_NAMESIZE) 102 return EINVAL; 103 104 (void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE); 105 106 if (minor < 256) { 107 suffix = TTY_OLD_SUFFIX; 108 nt = sizeof(TTY_OLD_SUFFIX) - 1; 109 } else { 110 minor -= 256; 111 suffix = TTY_NEW_SUFFIX; 112 nt = sizeof(TTY_NEW_SUFFIX) - 1; 113 } 114 115 bf[5] = c; 116 bf[8] = TTY_LETTERS[minor / nt]; 117 bf[9] = suffix[minor % nt]; 118 return 0; 119 } 120 121 122 static int 123 /*ARGSUSED*/ 124 pty_allocvp(struct ptm_pty *ptm, struct lwp *l, struct vnode **vp, dev_t dev, 125 char ms) 126 { 127 int error; 128 struct nameidata nd; 129 char name[TTY_NAMESIZE]; 130 131 error = (*ptm->makename)(ptm, l, name, sizeof(name), dev, ms); 132 if (error) 133 return error; 134 135 NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, UIO_SYSSPACE, name); 136 if ((error = namei(&nd)) != 0) 137 return error; 138 *vp = nd.ni_vp; 139 return 0; 140 } 141 142 143 static void 144 /*ARGSUSED*/ 145 pty_getvattr(struct ptm_pty *ptm, struct lwp *l, struct vattr *vattr) 146 { 147 VATTR_NULL(vattr); 148 /* get real uid */ 149 vattr->va_uid = kauth_cred_getuid(l->l_cred); 150 vattr->va_gid = TTY_GID; 151 vattr->va_mode = TTY_PERM; 152 } 153 #endif 154