xref: /csrg-svn/sys/kern/tty_tty.c (revision 39554)
1 /*
2  * Copyright (c) 1982, 1986 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  *
6  *	@(#)tty_tty.c	7.5 (Berkeley) 11/20/89
7  */
8 
9 /*
10  * Indirect driver for controlling tty.
11  */
12 #include "param.h"
13 #include "systm.h"
14 #include "conf.h"
15 #include "user.h"
16 #include "ioctl.h"
17 #include "tty.h"
18 #include "proc.h"
19 #include "vnode.h"
20 #include "file.h"
21 #include "uio.h"
22 
23 #define cttyvp(p) ((p)->p_flag&SCTTY ? (p)->p_session->s_ttyvp : NULL)
24 
25 static off_t dummyoff;
26 
27 /*ARGSUSED*/
28 syopen(dev, flag)
29 	dev_t dev;
30 	int flag;
31 {
32 	struct vnode *ttyvp = cttyvp(u.u_procp);
33 	int error;
34 
35 	if (ttyvp == NULL)
36 		return (ENXIO);
37 	if (error = VOP_ACCESS(ttyvp,
38 	   (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), u.u_cred))
39 		return (error);
40 	return (VOP_OPEN(ttyvp, flag, NOCRED));
41 }
42 
43 /*ARGSUSED*/
44 syread(dev, uio, flag)
45 	dev_t dev;
46 	struct uio *uio;
47 {
48 	struct vnode *ttyvp = cttyvp(u.u_procp);
49 
50 	if (ttyvp == NULL)
51 		return (ENXIO);
52 	return (VOP_READ(ttyvp, uio, &dummyoff, flag, NOCRED));
53 }
54 
55 /*ARGSUSED*/
56 sywrite(dev, uio, flag)
57 	dev_t dev;
58 	struct uio *uio;
59 {
60 	struct vnode *ttyvp = cttyvp(u.u_procp);
61 
62 	if (ttyvp == NULL)
63 		return (ENXIO);
64 	return (VOP_WRITE(ttyvp, uio, &dummyoff, flag, NOCRED));
65 }
66 
67 /*ARGSUSED*/
68 syioctl(dev, cmd, addr, flag)
69 	dev_t dev;
70 	int cmd;
71 	caddr_t addr;
72 	int flag;
73 {
74 	struct vnode *ttyvp = cttyvp(u.u_procp);
75 
76 	if (ttyvp == NULL)
77 		return (ENXIO);
78 	if (cmd == TIOCNOTTY) {
79 		if (!SESS_LEADER(u.u_procp)) {
80 			u.u_procp->p_flag &= ~SCTTY;
81 			return (0);
82 		} else
83 			return (EINVAL);
84 	}
85 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED));
86 }
87 
88 /*ARGSUSED*/
89 syselect(dev, flag)
90 	dev_t dev;
91 	int flag;
92 {
93 	struct vnode *ttyvp = cttyvp(u.u_procp);
94 
95 	if (ttyvp == NULL)
96 		return (ENXIO);
97 	return (VOP_SELECT(ttyvp, flag, NOCRED));
98 }
99