xref: /openbmc/qemu/chardev/char-stdio.c (revision dc5bd18f)
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     tcsetattr(0, TCSANOW, &oldtty);
50     fcntl(0, F_SETFL, old_fd0_flags);
51 }
52 
53 static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)
54 {
55     struct termios tty;
56 
57     stdio_echo_state = echo;
58     tty = oldtty;
59     if (!echo) {
60         tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
61                          | INLCR | IGNCR | ICRNL | IXON);
62         tty.c_oflag |= OPOST;
63         tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
64         tty.c_cflag &= ~(CSIZE | PARENB);
65         tty.c_cflag |= CS8;
66         tty.c_cc[VMIN] = 1;
67         tty.c_cc[VTIME] = 0;
68     }
69     if (!stdio_allow_signal) {
70         tty.c_lflag &= ~ISIG;
71     }
72 
73     tcsetattr(0, TCSANOW, &tty);
74 }
75 
76 static void term_stdio_handler(int sig)
77 {
78     /* restore echo after resume from suspend. */
79     qemu_chr_set_echo_stdio(NULL, stdio_echo_state);
80 }
81 
82 static void qemu_chr_open_stdio(Chardev *chr,
83                                 ChardevBackend *backend,
84                                 bool *be_opened,
85                                 Error **errp)
86 {
87     ChardevStdio *opts = backend->u.stdio.data;
88     struct sigaction act;
89 
90     if (is_daemonized()) {
91         error_setg(errp, "cannot use stdio with -daemonize");
92         return;
93     }
94 
95     if (stdio_in_use) {
96         error_setg(errp, "cannot use stdio by multiple character devices");
97         return;
98     }
99 
100     stdio_in_use = true;
101     old_fd0_flags = fcntl(0, F_GETFL);
102     tcgetattr(0, &oldtty);
103     qemu_set_nonblock(0);
104     atexit(term_exit);
105 
106     memset(&act, 0, sizeof(act));
107     act.sa_handler = term_stdio_handler;
108     sigaction(SIGCONT, &act, NULL);
109 
110     qemu_chr_open_fd(chr, 0, 1);
111 
112     if (opts->has_signal) {
113         stdio_allow_signal = opts->signal;
114     }
115     qemu_chr_set_echo_stdio(chr, false);
116 }
117 #endif
118 
119 static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
120                                  Error **errp)
121 {
122     ChardevStdio *stdio;
123 
124     backend->type = CHARDEV_BACKEND_KIND_STDIO;
125     stdio = backend->u.stdio.data = g_new0(ChardevStdio, 1);
126     qemu_chr_parse_common(opts, qapi_ChardevStdio_base(stdio));
127     stdio->has_signal = true;
128     stdio->signal = qemu_opt_get_bool(opts, "signal", true);
129 }
130 
131 static void char_stdio_class_init(ObjectClass *oc, void *data)
132 {
133     ChardevClass *cc = CHARDEV_CLASS(oc);
134 
135     cc->parse = qemu_chr_parse_stdio;
136 #ifndef _WIN32
137     cc->open = qemu_chr_open_stdio;
138     cc->chr_set_echo = qemu_chr_set_echo_stdio;
139 #endif
140 }
141 
142 static void char_stdio_finalize(Object *obj)
143 {
144 #ifndef _WIN32
145     term_exit();
146 #endif
147 }
148 
149 static const TypeInfo char_stdio_type_info = {
150     .name = TYPE_CHARDEV_STDIO,
151 #ifdef _WIN32
152     .parent = TYPE_CHARDEV_WIN_STDIO,
153 #else
154     .parent = TYPE_CHARDEV_FD,
155 #endif
156     .instance_finalize = char_stdio_finalize,
157     .class_init = char_stdio_class_init,
158 };
159 
160 static void register_types(void)
161 {
162     type_register_static(&char_stdio_type_info);
163 }
164 
165 type_init(register_types);
166