1 /* $NetBSD: tty_bsdpty.c,v 1.17 2010/11/19 06:44:43 dholland 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 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c,v 1.17 2010/11/19 06:44:43 dholland Exp $"); 31 32 #include "opt_ptm.h" 33 34 #ifdef COMPAT_BSDPTY 35 /* bsd tty implementation for pty multiplexor driver /dev/ptm{,x} */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/ioctl.h> 40 #include <sys/lwp.h> 41 #include <sys/tty.h> 42 #include <sys/stat.h> 43 #include <sys/file.h> 44 #include <sys/uio.h> 45 #include <sys/kernel.h> 46 #include <sys/vnode.h> 47 #include <sys/namei.h> 48 #include <sys/signalvar.h> 49 #include <sys/filedesc.h> 50 #include <sys/conf.h> 51 #include <sys/poll.h> 52 #include <sys/pty.h> 53 #include <sys/kauth.h> 54 55 /* 56 * pts == /dev/tty[pqrs]? 57 * ptc == /dev/pty[pqrs]? 58 */ 59 60 /* 61 * All this hard-coding is really evil. 62 */ 63 #define TTY_GID 4 64 #define TTY_PERM (S_IRUSR|S_IWUSR|S_IWGRP) 65 #define TTY_TEMPLATE "/dev/XtyXX" 66 #define TTY_NAMESIZE sizeof(TTY_TEMPLATE) 67 #define TTY_LETTERS "pqrstuvwxyzPQRST" 68 #define TTY_OLD_SUFFIX "0123456789abcdef" 69 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 70 71 static int pty_makename(struct ptm_pty *, struct lwp *, char *, size_t, dev_t, 72 char); 73 static int pty_allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 74 dev_t, char); 75 static void pty_getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 76 77 struct ptm_pty ptm_bsdpty = { 78 pty_allocvp, 79 pty_makename, 80 pty_getvattr, 81 NULL 82 }; 83 84 static int 85 /*ARGSUSED*/ 86 pty_makename(struct ptm_pty *ptm, struct lwp *l, char *bf, 87 size_t bufsiz, dev_t dev, char c) 88 { 89 size_t nt; 90 dev_t minor = minor(dev); 91 const char *suffix; 92 93 if (bufsiz < TTY_NAMESIZE) 94 return EINVAL; 95 96 (void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE); 97 98 if (minor < 256) { 99 suffix = TTY_OLD_SUFFIX; 100 nt = sizeof(TTY_OLD_SUFFIX) - 1; 101 } else { 102 minor -= 256; 103 suffix = TTY_NEW_SUFFIX; 104 nt = sizeof(TTY_NEW_SUFFIX) - 1; 105 } 106 107 bf[5] = c; 108 bf[8] = TTY_LETTERS[minor / nt]; 109 bf[9] = suffix[minor % nt]; 110 return 0; 111 } 112 113 114 static int 115 /*ARGSUSED*/ 116 pty_allocvp(struct ptm_pty *ptm, struct lwp *l, struct vnode **vp, dev_t dev, 117 char ms) 118 { 119 int error; 120 struct pathbuf *pb; 121 struct nameidata nd; 122 char name[TTY_NAMESIZE]; 123 124 error = (*ptm->makename)(ptm, l, name, sizeof(name), dev, ms); 125 if (error) 126 return error; 127 128 pb = pathbuf_create(name); 129 if (pb == NULL) { 130 return ENOMEM; 131 } 132 133 NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, pb); 134 if ((error = namei(&nd)) != 0) { 135 pathbuf_destroy(pb); 136 return error; 137 } 138 *vp = nd.ni_vp; 139 pathbuf_destroy(pb); 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