1 /* $NetBSD: tty_bsdpty.c,v 1.14 2008/04/28 20:24:05 martin 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 1.14 2008/04/28 20:24:05 martin 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/malloc.h> 53 #include <sys/pty.h> 54 #include <sys/kauth.h> 55 56 /* 57 * pts == /dev/tty[pqrs]? 58 * ptc == /dev/pty[pqrs]? 59 */ 60 61 /* 62 * All this hard-coding is really evil. 63 */ 64 #define TTY_GID 4 65 #define TTY_PERM (S_IRUSR|S_IWUSR|S_IWGRP) 66 #define TTY_TEMPLATE "/dev/XtyXX" 67 #define TTY_NAMESIZE sizeof(TTY_TEMPLATE) 68 #define TTY_LETTERS "pqrstuvwxyzPQRST" 69 #define TTY_OLD_SUFFIX "0123456789abcdef" 70 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 71 72 static int pty_makename(struct ptm_pty *, struct lwp *, char *, size_t, dev_t, 73 char); 74 static int pty_allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 75 dev_t, char); 76 static void pty_getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 77 78 struct ptm_pty ptm_bsdpty = { 79 pty_allocvp, 80 pty_makename, 81 pty_getvattr, 82 NULL 83 }; 84 85 static int 86 /*ARGSUSED*/ 87 pty_makename(struct ptm_pty *ptm, struct lwp *l, char *bf, 88 size_t bufsiz, dev_t dev, char c) 89 { 90 size_t nt; 91 dev_t minor = minor(dev); 92 const char *suffix; 93 94 if (bufsiz < TTY_NAMESIZE) 95 return EINVAL; 96 97 (void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE); 98 99 if (minor < 256) { 100 suffix = TTY_OLD_SUFFIX; 101 nt = sizeof(TTY_OLD_SUFFIX) - 1; 102 } else { 103 minor -= 256; 104 suffix = TTY_NEW_SUFFIX; 105 nt = sizeof(TTY_NEW_SUFFIX) - 1; 106 } 107 108 bf[5] = c; 109 bf[8] = TTY_LETTERS[minor / nt]; 110 bf[9] = suffix[minor % nt]; 111 return 0; 112 } 113 114 115 static int 116 /*ARGSUSED*/ 117 pty_allocvp(struct ptm_pty *ptm, struct lwp *l, struct vnode **vp, dev_t dev, 118 char ms) 119 { 120 int error; 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 NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, UIO_SYSSPACE, name); 129 if ((error = namei(&nd)) != 0) 130 return error; 131 *vp = nd.ni_vp; 132 return 0; 133 } 134 135 136 static void 137 /*ARGSUSED*/ 138 pty_getvattr(struct ptm_pty *ptm, struct lwp *l, struct vattr *vattr) 139 { 140 VATTR_NULL(vattr); 141 /* get real uid */ 142 vattr->va_uid = kauth_cred_getuid(l->l_cred); 143 vattr->va_gid = TTY_GID; 144 vattr->va_mode = TTY_PERM; 145 } 146 #endif 147