xref: /openbmc/qemu/chardev/char-stdio.c (revision 6c090d4a)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/option.h"
27 #include "qemu/sockets.h"
28 #include "qapi/error.h"
29 #include "chardev/char.h"
30 
31 #ifdef _WIN32
32 #include "chardev/char-win.h"
33 #include "chardev/char-win-stdio.h"
34 #else
35 #include <termios.h>
36 #include "chardev/char-fd.h"
37 #endif
38 
39 #ifndef _WIN32
40 /* init terminal so that we can grab keys */
41 static struct termios oldtty;
42 static int old_fd0_flags;
43 static bool stdio_in_use;
44 static bool stdio_allow_signal;
45 static bool stdio_echo_state;
46 
47 static void term_exit(void)
48 {
49     if (stdio_in_use) {
50         tcsetattr(0, TCSANOW, &oldtty);
51         fcntl(0, F_SETFL, old_fd0_flags);
52     }
53 }
54 
55 static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)
56 {
57     struct termios tty;
58 
59     stdio_echo_state = echo;
60     tty = oldtty;
61     if (!echo) {
62         tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
63                          | INLCR | IGNCR | ICRNL | IXON);
64         tty.c_oflag |= OPOST;
65         tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
66         tty.c_cflag &= ~(CSIZE | PARENB);
67         tty.c_cflag |= CS8;
68         tty.c_cc[VMIN] = 1;
69         tty.c_cc[VTIME] = 0;
70     }
71     if (!stdio_allow_signal) {
72         tty.c_lflag &= ~ISIG;
73     }
74 
75     tcsetattr(0, TCSANOW, &tty);
76 }
77 
78 static void term_stdio_handler(int sig)
79 {
80     /* restore echo after resume from suspend. */
81     qemu_chr_set_echo_stdio(NULL, stdio_echo_state);
82 }
83 
84 static void qemu_chr_open_stdio(Chardev *chr,
85                                 ChardevBackend *backend,
86                                 bool *be_opened,
87                                 Error **errp)
88 {
89     ChardevStdio *opts = backend->u.stdio.data;
90     struct sigaction act;
91 
92     if (is_daemonized()) {
93         error_setg(errp, "cannot use stdio with -daemonize");
94         return;
95     }
96 
97     if (stdio_in_use) {
98         error_setg(errp, "cannot use stdio by multiple character devices");
99         return;
100     }
101 
102     stdio_in_use = true;
103     old_fd0_flags = fcntl(0, F_GETFL);
104     tcgetattr(0, &oldtty);
105     qemu_set_nonblock(0);
106     atexit(term_exit);
107 
108     memset(&act, 0, sizeof(act));
109     act.sa_handler = term_stdio_handler;
110     sigaction(SIGCONT, &act, NULL);
111 
112     qemu_chr_open_fd(chr, 0, 1);
113 
114     if (opts->has_signal) {
115         stdio_allow_signal = opts->signal;
116     }
117     qemu_chr_set_echo_stdio(chr, false);
118 }
119 #endif
120 
121 static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
122                                  Error **errp)
123 {
124     ChardevStdio *stdio;
125 
126     backend->type = CHARDEV_BACKEND_KIND_STDIO;
127     stdio = backend->u.stdio.data = g_new0(ChardevStdio, 1);
128     qemu_chr_parse_common(opts, qapi_ChardevStdio_base(stdio));
129     stdio->has_signal = true;
130     stdio->signal = qemu_opt_get_bool(opts, "signal", true);
131 }
132 
133 static void char_stdio_class_init(ObjectClass *oc, void *data)
134 {
135     ChardevClass *cc = CHARDEV_CLASS(oc);
136 
137     cc->parse = qemu_chr_parse_stdio;
138 #ifndef _WIN32
139     cc->open = qemu_chr_open_stdio;
140     cc->chr_set_echo = qemu_chr_set_echo_stdio;
141 #endif
142 }
143 
144 static void char_stdio_finalize(Object *obj)
145 {
146 #ifndef _WIN32
147     term_exit();
148 #endif
149 }
150 
151 static const TypeInfo char_stdio_type_info = {
152     .name = TYPE_CHARDEV_STDIO,
153 #ifdef _WIN32
154     .parent = TYPE_CHARDEV_WIN_STDIO,
155 #else
156     .parent = TYPE_CHARDEV_FD,
157 #endif
158     .instance_finalize = char_stdio_finalize,
159     .class_init = char_stdio_class_init,
160 };
161 
162 static void register_types(void)
163 {
164     type_register_static(&char_stdio_type_info);
165 }
166 
167 type_init(register_types);
168