1 | /* |
2 | * Copyright (c) 2000-2007 Apple Inc. All rights reserved. |
3 | */ |
4 | /* |
5 | * Copyright (c) 1987, 1988 NeXT, Inc. |
6 | * |
7 | * HISTORY 7-Jan-93 Mac Gillon (mgillon) at NeXT Integrated POSIX support |
8 | * |
9 | * 12-Aug-87 John Seamons (jks) at NeXT Ported to NeXT. |
10 | */ |
11 | |
12 | /* |
13 | * Indirect driver for console. |
14 | */ |
15 | #include <kern/locks.h> |
16 | #include <machine/cons.h> |
17 | #include <sys/param.h> |
18 | #include <sys/systm.h> |
19 | #include <sys/conf.h> |
20 | #include <sys/ioctl.h> |
21 | #include <sys/tty.h> |
22 | #include <sys/proc.h> |
23 | #include <sys/uio.h> |
24 | |
25 | static struct tty *_constty; /* current console device */ |
26 | static LCK_GRP_DECLARE(_constty_lock_grp, "constty" ); |
27 | static LCK_MTX_DECLARE(_constty_lock, &_constty_lock_grp); |
28 | |
29 | struct tty * |
30 | copy_constty(void) |
31 | { |
32 | struct tty *result = NULL; |
33 | lck_mtx_lock(lck: &_constty_lock); |
34 | if (_constty != NULL) { |
35 | ttyhold(tp: _constty); |
36 | result = _constty; |
37 | } |
38 | lck_mtx_unlock(lck: &_constty_lock); |
39 | return result; |
40 | } |
41 | |
42 | struct tty * |
43 | set_constty(struct tty *new_tty) |
44 | { |
45 | struct tty *old_tty = NULL; |
46 | lck_mtx_lock(lck: &_constty_lock); |
47 | old_tty = _constty; |
48 | _constty = new_tty; |
49 | if (_constty) { |
50 | ttyhold(tp: _constty); |
51 | } |
52 | lck_mtx_unlock(lck: &_constty_lock); |
53 | |
54 | return old_tty; |
55 | } |
56 | |
57 | /* |
58 | * The km driver supplied the default console device for the systems |
59 | * (usually a raw frame buffer driver, but potentially a serial driver). |
60 | */ |
61 | extern struct tty *km_tty[1]; |
62 | |
63 | /* |
64 | * cdevsw[] entries for the console device driver |
65 | */ |
66 | int cnopen(__unused dev_t dev, int flag, int devtype, proc_t pp); |
67 | int cnclose(__unused dev_t dev, int flag, int mode, proc_t pp); |
68 | int cnread(__unused dev_t dev, struct uio *uio, int ioflag); |
69 | int cnwrite(__unused dev_t dev, struct uio *uio, int ioflag); |
70 | int cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flg, proc_t p); |
71 | int cnselect(__unused dev_t dev, int flag, void * wql, proc_t p); |
72 | |
73 | int |
74 | cnopen(__unused dev_t dev, int flag, int devtype, struct proc *pp) |
75 | { |
76 | int error; |
77 | struct tty *constty = copy_constty(); |
78 | if (constty) { |
79 | dev = constty->t_dev; |
80 | } else { |
81 | dev = km_tty[0]->t_dev; |
82 | } |
83 | error = (*cdevsw[major(dev)].d_open)(dev, flag, devtype, pp); |
84 | if (constty != NULL) { |
85 | ttyfree(constty); |
86 | } |
87 | return error; |
88 | } |
89 | |
90 | |
91 | int |
92 | cnclose(__unused dev_t dev, int flag, int mode, struct proc *pp) |
93 | { |
94 | int error; |
95 | struct tty *constty = copy_constty(); |
96 | if (constty) { |
97 | dev = constty->t_dev; |
98 | } else { |
99 | dev = km_tty[0]->t_dev; |
100 | } |
101 | error = (*cdevsw[major(dev)].d_close)(dev, flag, mode, pp); |
102 | if (constty != NULL) { |
103 | ttyfree(constty); |
104 | } |
105 | return error; |
106 | } |
107 | |
108 | |
109 | int |
110 | cnread(__unused dev_t dev, struct uio *uio, int ioflag) |
111 | { |
112 | int error; |
113 | struct tty *constty = copy_constty(); |
114 | if (constty) { |
115 | dev = constty->t_dev; |
116 | } else { |
117 | dev = km_tty[0]->t_dev; |
118 | } |
119 | error = (*cdevsw[major(dev)].d_read)(dev, uio, ioflag); |
120 | if (constty != NULL) { |
121 | ttyfree(constty); |
122 | } |
123 | return error; |
124 | } |
125 | |
126 | |
127 | int |
128 | cnwrite(__unused dev_t dev, struct uio *uio, int ioflag) |
129 | { |
130 | int error; |
131 | struct tty *constty = copy_constty(); |
132 | if (constty) { |
133 | dev = constty->t_dev; |
134 | } else { |
135 | dev = km_tty[0]->t_dev; |
136 | } |
137 | error = (*cdevsw[major(dev)].d_write)(dev, uio, ioflag); |
138 | if (constty != NULL) { |
139 | ttyfree(constty); |
140 | } |
141 | return error; |
142 | } |
143 | |
144 | |
145 | int |
146 | cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p) |
147 | { |
148 | int error; |
149 | struct tty *constty = copy_constty(); |
150 | struct tty *freetp = NULL; |
151 | if (constty) { |
152 | dev = constty->t_dev; |
153 | } else { |
154 | dev = km_tty[0]->t_dev; |
155 | } |
156 | |
157 | /* |
158 | * XXX This check prevents the cons.c code from being shared between |
159 | * XXX all architectures; it is probably not needed on ARM, either, |
160 | * XXX but I have no test platforms or ability to run a kernel. |
161 | * |
162 | * Superuser can always use this to wrest control of console |
163 | * output from the "virtual" console. |
164 | */ |
165 | if ((unsigned) cmd == TIOCCONS && constty) { |
166 | error = proc_suser(p); |
167 | if (error) { |
168 | goto finish; |
169 | } |
170 | freetp = set_constty(NULL); |
171 | if (freetp) { |
172 | ttyfree(freetp); |
173 | freetp = NULL; |
174 | } |
175 | } else { |
176 | error = (*cdevsw[major(dev)].d_ioctl)(dev, cmd, addr, flag, p); |
177 | } |
178 | finish: |
179 | if (constty != NULL) { |
180 | ttyfree(constty); |
181 | } |
182 | return error; |
183 | } |
184 | |
185 | |
186 | int |
187 | cnselect(__unused dev_t dev, int flag, void *wql, struct proc *p) |
188 | { |
189 | int error; |
190 | struct tty *constty = copy_constty(); |
191 | if (constty) { |
192 | dev = constty->t_dev; |
193 | } else { |
194 | dev = km_tty[0]->t_dev; |
195 | } |
196 | error = (*cdevsw[major(dev)].d_select)(dev, flag, wql, p); |
197 | if (constty != NULL) { |
198 | ttyfree(constty); |
199 | } |
200 | return error; |
201 | } |
202 | |