1 /* $NetBSD: tty_bsdpty.c,v 1.20 2014/04/04 18:11:58 christos 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 1.20 2014/04/04 18:11:58 christos Exp $"); 31 32 #include "opt_ptm.h" 33 34 #ifndef NO_DEV_PTM 35 #ifdef COMPAT_BSDPTY 36 /* bsd tty implementation for pty multiplexor driver /dev/ptm{,x} */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/ioctl.h> 41 #include <sys/lwp.h> 42 #include <sys/tty.h> 43 #include <sys/stat.h> 44 #include <sys/file.h> 45 #include <sys/uio.h> 46 #include <sys/kernel.h> 47 #include <sys/vnode.h> 48 #include <sys/namei.h> 49 #include <sys/signalvar.h> 50 #include <sys/filedesc.h> 51 #include <sys/conf.h> 52 #include <sys/poll.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 mount *, struct lwp *, char *, size_t, dev_t, 73 char); 74 static int pty_allocvp(struct mount *, struct lwp *, struct vnode **, 75 dev_t, char); 76 static void pty_getvattr(struct mount *, struct lwp *, struct vattr *); 77 static int pty__getmp(struct lwp *, struct mount **); 78 79 struct ptm_pty ptm_bsdpty = { 80 pty_allocvp, 81 pty_makename, 82 pty_getvattr, 83 pty__getmp, 84 }; 85 86 static int 87 /*ARGSUSED*/ 88 pty_makename(struct mount *mp, struct lwp *l, char *bf, 89 size_t bufsiz, dev_t dev, char c) 90 { 91 size_t nt; 92 dev_t minor = minor(dev); 93 const char *suffix; 94 95 if (bufsiz < TTY_NAMESIZE) 96 return EINVAL; 97 98 (void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE); 99 100 if (minor < 256) { 101 suffix = TTY_OLD_SUFFIX; 102 nt = sizeof(TTY_OLD_SUFFIX) - 1; 103 } else { 104 minor -= 256; 105 suffix = TTY_NEW_SUFFIX; 106 nt = sizeof(TTY_NEW_SUFFIX) - 1; 107 } 108 109 bf[5] = c; 110 bf[8] = TTY_LETTERS[minor / nt]; 111 bf[9] = suffix[minor % nt]; 112 return 0; 113 } 114 115 116 static int 117 /*ARGSUSED*/ 118 pty_allocvp(struct mount *mp, struct lwp *l, struct vnode **vp, dev_t dev, 119 char ms) 120 { 121 int error; 122 struct pathbuf *pb; 123 struct nameidata nd; 124 char name[TTY_NAMESIZE]; 125 126 error = pty_makename(NULL, l, name, sizeof(name), dev, ms); 127 if (error) 128 return error; 129 130 pb = pathbuf_create(name); 131 if (pb == NULL) { 132 return ENOMEM; 133 } 134 135 NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, pb); 136 if ((error = namei(&nd)) != 0) { 137 pathbuf_destroy(pb); 138 return error; 139 } 140 *vp = nd.ni_vp; 141 pathbuf_destroy(pb); 142 return 0; 143 } 144 145 146 static void 147 /*ARGSUSED*/ 148 pty_getvattr(struct mount *mp, struct lwp *l, struct vattr *vattr) 149 { 150 vattr_null(vattr); 151 /* get real uid */ 152 vattr->va_uid = kauth_cred_getuid(l->l_cred); 153 vattr->va_gid = TTY_GID; 154 vattr->va_mode = TTY_PERM; 155 } 156 157 static int 158 pty__getmp(struct lwp *l __unused, struct mount **mpp) 159 { 160 *mpp = 0; 161 return 0; 162 } 163 164 #endif /* COMPAT_BSDPTY */ 165 #endif /* NO_DEV_PTM */ 166