1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 31 #pragma ident "%Z%%M% %I% %E% SMI" 32 33 #include <sys/types.h> 34 #include <sys/sysmacros.h> 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/file.h> 38 #include <sys/vnode.h> 39 #include <sys/errno.h> 40 #include <sys/signal.h> 41 #include <sys/cred.h> 42 #include <sys/policy.h> 43 #include <sys/conf.h> 44 #include <sys/debug.h> 45 #include <sys/proc.h> 46 #include <sys/session.h> 47 #include <sys/kmem.h> 48 #include <sys/cmn_err.h> 49 #include <sys/strsubr.h> 50 51 sess_t session0 = { 52 1, /* s_ref */ 53 NODEV, /* s_dev */ 54 NULL, /* s_vp */ 55 &pid0, /* s_sidp */ 56 NULL /* s_cred */ 57 }; 58 59 void 60 sess_rele(sess_t *sp) 61 { 62 ASSERT(MUTEX_HELD(&pidlock)); 63 64 ASSERT(sp->s_ref != 0); 65 if (--sp->s_ref == 0) { 66 if (sp == &session0) 67 panic("sp == &session0"); 68 PID_RELE(sp->s_sidp); 69 mutex_destroy(&sp->s_lock); 70 cv_destroy(&sp->s_wait_cv); 71 kmem_free(sp, sizeof (sess_t)); 72 } 73 } 74 75 void 76 sess_create(void) 77 { 78 proc_t *pp; 79 sess_t *sp; 80 81 pp = ttoproc(curthread); 82 83 sp = kmem_zalloc(sizeof (sess_t), KM_SLEEP); 84 85 mutex_init(&sp->s_lock, NULL, MUTEX_DEFAULT, NULL); 86 cv_init(&sp->s_wait_cv, NULL, CV_DEFAULT, NULL); 87 88 mutex_enter(&pidlock); 89 90 /* 91 * We need to protect p_pgidp with p_lock because 92 * /proc looks at it while holding only p_lock. 93 */ 94 mutex_enter(&pp->p_lock); 95 pgexit(pp); 96 SESS_RELE(pp->p_sessp); 97 98 sp->s_sidp = pp->p_pidp; 99 sp->s_ref = 1; 100 sp->s_dev = NODEV; 101 102 pp->p_sessp = sp; 103 104 pgjoin(pp, pp->p_pidp); 105 mutex_exit(&pp->p_lock); 106 107 PID_HOLD(sp->s_sidp); 108 mutex_exit(&pidlock); 109 } 110 111 void 112 freectty(sess_t *sp) 113 { 114 vnode_t *vp = sp->s_vp; 115 cred_t *cred = sp->s_cred; 116 117 strfreectty(vp->v_stream); 118 119 mutex_enter(&sp->s_lock); 120 while (sp->s_cnt > 0) { 121 cv_wait(&sp->s_wait_cv, &sp->s_lock); 122 } 123 ASSERT(sp->s_cnt == 0); 124 ASSERT(vp->v_count >= 1); 125 sp->s_vp = NULL; 126 sp->s_cred = NULL; 127 128 /* 129 * It is possible for the VOP_CLOSE below to call stralloctty() 130 * and reallocate a new tty vnode. To prevent that the 131 * session is marked as closing here. 132 */ 133 134 sp->s_flag = SESS_CLOSE; 135 mutex_exit(&sp->s_lock); 136 137 /* 138 * This will be the only thread with access to 139 * this vnode, from this point on. 140 */ 141 142 (void) VOP_CLOSE(vp, 0, 1, (offset_t)0, cred); 143 VN_RELE(vp); 144 145 crfree(cred); 146 } 147 148 /* 149 * ++++++++++++++++++++++++ 150 * ++ SunOS4.1 Buyback ++ 151 * ++++++++++++++++++++++++ 152 * 153 * vhangup: Revoke access of the current tty by all processes 154 * Used by privileged users to give a "clean" terminal at login 155 */ 156 int 157 vhangup(void) 158 { 159 if (secpolicy_sys_config(CRED(), B_FALSE) != 0) 160 return (set_errno(EPERM)); 161 /* 162 * This routine used to call freectty() under a condition that 163 * could never happen. So this code has never actually done 164 * anything, and evidently nobody has ever noticed. 165 */ 166 return (0); 167 } 168 169 dev_t 170 cttydev(proc_t *pp) 171 { 172 sess_t *sp = pp->p_sessp; 173 if (sp->s_vp == NULL) 174 return (NODEV); 175 return (sp->s_dev); 176 } 177 178 void 179 alloctty(proc_t *pp, vnode_t *vp) 180 { 181 sess_t *sp = pp->p_sessp; 182 cred_t *crp; 183 184 sp->s_vp = vp; 185 sp->s_dev = vp->v_rdev; 186 187 mutex_enter(&pp->p_crlock); 188 crhold(crp = pp->p_cred); 189 mutex_exit(&pp->p_crlock); 190 sp->s_cred = crp; 191 } 192