xref: /openbmc/qemu/chardev/char-stdio.c (revision 80adf54e)
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 #include "qemu/osdep.h"
25 #include "qemu/sockets.h"
26 #include "qapi/error.h"
27 #include "qemu-common.h"
28 #include "chardev/char.h"
29 
30 #ifdef _WIN32
31 #include "chardev/char-win.h"
32 #include "chardev/char-win-stdio.h"
33 #else
34 #include <termios.h>
35 #include "chardev/char-fd.h"
36 #endif
37 
38 #ifndef _WIN32
39 /* init terminal so that we can grab keys */
40 static struct termios oldtty;
41 static int old_fd0_flags;
42 static bool stdio_in_use;
43 static bool stdio_allow_signal;
44 static bool stdio_echo_state;
45 
46 static void term_exit(void)
47 {
48     tcsetattr(0, TCSANOW, &oldtty);
49     fcntl(0, F_SETFL, old_fd0_flags);
50 }
51 
52 static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)
53 {
54     struct termios tty;
55 
56     stdio_echo_state = echo;
57     tty = oldtty;
58     if (!echo) {
59         tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
60                          | INLCR | IGNCR | ICRNL | IXON);
61         tty.c_oflag |= OPOST;
62         tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
63         tty.c_cflag &= ~(CSIZE | PARENB);
64         tty.c_cflag |= CS8;
65         tty.c_cc[VMIN] = 1;
66         tty.c_cc[VTIME] = 0;
67     }
68     if (!stdio_allow_signal) {
69         tty.c_lflag &= ~ISIG;
70     }
71 
72     tcsetattr(0, TCSANOW, &tty);
73 }
74 
75 static void term_stdio_handler(int sig)
76 {
77     /* restore echo after resume from suspend. */
78     qemu_chr_set_echo_stdio(NULL, stdio_echo_state);
79 }
80 
81 static void qemu_chr_open_stdio(Chardev *chr,
82                                 ChardevBackend *backend,
83                                 bool *be_opened,
84                                 Error **errp)
85 {
86     ChardevStdio *opts = backend->u.stdio.data;
87     struct sigaction act;
88 
89     if (is_daemonized()) {
90         error_setg(errp, "cannot use stdio with -daemonize");
91         return;
92     }
93 
94     if (stdio_in_use) {
95         error_setg(errp, "cannot use stdio by multiple character devices");
96         return;
97     }
98 
99     stdio_in_use = true;
100     old_fd0_flags = fcntl(0, F_GETFL);
101     tcgetattr(0, &oldtty);
102     qemu_set_nonblock(0);
103     atexit(term_exit);
104 
105     memset(&act, 0, sizeof(act));
106     act.sa_handler = term_stdio_handler;
107     sigaction(SIGCONT, &act, NULL);
108 
109     qemu_chr_open_fd(chr, 0, 1);
110 
111     if (opts->has_signal) {
112         stdio_allow_signal = opts->signal;
113     }
114     qemu_chr_set_echo_stdio(chr, false);
115 }
116 #endif
117 
118 static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
119                                  Error **errp)
120 {
121     ChardevStdio *stdio;
122 
123     backend->type = CHARDEV_BACKEND_KIND_STDIO;
124     stdio = backend->u.stdio.data = g_new0(ChardevStdio, 1);
125     qemu_chr_parse_common(opts, qapi_ChardevStdio_base(stdio));
126     stdio->has_signal = true;
127     stdio->signal = qemu_opt_get_bool(opts, "signal", true);
128 }
129 
130 static void char_stdio_class_init(ObjectClass *oc, void *data)
131 {
132     ChardevClass *cc = CHARDEV_CLASS(oc);
133 
134     cc->parse = qemu_chr_parse_stdio;
135 #ifndef _WIN32
136     cc->open = qemu_chr_open_stdio;
137     cc->chr_set_echo = qemu_chr_set_echo_stdio;
138 #endif
139 }
140 
141 static void char_stdio_finalize(Object *obj)
142 {
143 #ifndef _WIN32
144     term_exit();
145 #endif
146 }
147 
148 static const TypeInfo char_stdio_type_info = {
149     .name = TYPE_CHARDEV_STDIO,
150 #ifdef _WIN32
151     .parent = TYPE_CHARDEV_WIN_STDIO,
152 #else
153     .parent = TYPE_CHARDEV_FD,
154 #endif
155     .instance_finalize = char_stdio_finalize,
156     .class_init = char_stdio_class_init,
157 };
158 
159 static void register_types(void)
160 {
161     type_register_static(&char_stdio_type_info);
162 }
163 
164 type_init(register_types);
165