1 /* $OpenBSD: tty_tty.c,v 1.33 2024/09/30 12:32:26 claudio Exp $ */
2 /* $NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $ */
3
4 /*-
5 * Copyright (c) 1982, 1986, 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
33 */
34
35 /*
36 * Indirect driver for controlling tty.
37 */
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/proc.h>
41 #include <sys/tty.h>
42 #include <sys/vnode.h>
43 #include <sys/lock.h>
44 #include <sys/fcntl.h>
45
46
47 #define cttyvp(p) \
48 ((p)->p_p->ps_flags & PS_CONTROLT ? \
49 (p)->p_p->ps_session->s_ttyvp : NULL)
50
51 int
cttyopen(dev_t dev,int flag,int mode,struct proc * p)52 cttyopen(dev_t dev, int flag, int mode, struct proc *p)
53 {
54 struct vnode *ttyvp = cttyvp(p);
55 int error;
56
57 if (ttyvp == NULL)
58 return (ENXIO);
59 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
60 error = VOP_OPEN(ttyvp, flag, NOCRED, p);
61 VOP_UNLOCK(ttyvp);
62 return (error);
63 }
64
65 int
cttyread(dev_t dev,struct uio * uio,int flag)66 cttyread(dev_t dev, struct uio *uio, int flag)
67 {
68 struct vnode *ttyvp = cttyvp(uio->uio_procp);
69 int error;
70
71 if (ttyvp == NULL)
72 return (EIO);
73 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
74 error = VOP_READ(ttyvp, uio, flag, NOCRED);
75 VOP_UNLOCK(ttyvp);
76 return (error);
77 }
78
79 int
cttywrite(dev_t dev,struct uio * uio,int flag)80 cttywrite(dev_t dev, struct uio *uio, int flag)
81 {
82 struct vnode *ttyvp = cttyvp(uio->uio_procp);
83 int error;
84
85 if (ttyvp == NULL)
86 return (EIO);
87 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
88 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
89 VOP_UNLOCK(ttyvp);
90 return (error);
91 }
92
93 int
cttyioctl(dev_t dev,u_long cmd,caddr_t addr,int flag,struct proc * p)94 cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
95 {
96 struct vnode *ttyvp = cttyvp(p);
97 struct session *sess;
98 int error, secs;
99
100 if (ttyvp == NULL)
101 return (EIO);
102 if (cmd == TIOCSCTTY) /* XXX */
103 return (EINVAL);
104 if (cmd == TIOCNOTTY) {
105 if (!SESS_LEADER(p->p_p)) {
106 atomic_clearbits_int(&p->p_p->ps_flags, PS_CONTROLT);
107 return (0);
108 } else
109 return (EINVAL);
110 }
111 switch (cmd) {
112 case TIOCSETVERAUTH:
113 if ((error = suser(p)))
114 return error;
115 secs = *(int *)addr;
116 if (secs < 1 || secs > 3600)
117 return EINVAL;
118 sess = p->p_p->ps_pgrp->pg_session;
119 sess->s_verauthuid = p->p_ucred->cr_ruid;
120 sess->s_verauthppid = p->p_p->ps_ppid;
121 timeout_add_sec(&sess->s_verauthto, secs);
122 return 0;
123 case TIOCCLRVERAUTH:
124 sess = p->p_p->ps_pgrp->pg_session;
125 timeout_del(&sess->s_verauthto);
126 zapverauth(sess);
127 return 0;
128 case TIOCCHKVERAUTH:
129 /*
130 * It's not clear when or what these checks are for.
131 * How can we reach this code with a different ruid?
132 * The ppid check is also more porous than desired.
133 * Nevertheless, the checks reflect the original intention;
134 * namely, that it be the same user using the same shell.
135 */
136 sess = p->p_p->ps_pgrp->pg_session;
137 if (sess->s_verauthuid == p->p_ucred->cr_ruid &&
138 sess->s_verauthppid == p->p_p->ps_ppid)
139 return 0;
140 return EPERM;
141 }
142 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
143 }
144
145 int
cttykqfilter(dev_t dev,struct knote * kn)146 cttykqfilter(dev_t dev, struct knote *kn)
147 {
148 struct vnode *ttyvp = cttyvp(curproc);
149
150 if (ttyvp == NULL) {
151 if (kn->kn_flags & (__EV_POLL | __EV_SELECT))
152 return (seltrue_kqfilter(dev, kn));
153 return (ENXIO);
154 }
155 return (VOP_KQFILTER(ttyvp, FREAD|FWRITE, kn));
156 }
157