chardev/char-stdio.c

   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/module.h"
  27 #include "qemu/option.h"
  28 #include "qemu/sockets.h"
  29 #include "qapi/error.h"
  30 #include "chardev/char.h"
  31
  32 #ifdef _WIN32
  33 #include "chardev/char-win.h"
  34 #include "chardev/char-win-stdio.h"
  35 #else
  36 #include <termios.h>
  37 #include "chardev/char-fd.h"
  38 #endif
  39
  40 #ifndef _WIN32
  41 /* init terminal so that we can grab keys */
  42 static struct termios oldtty;
  43 static int old_fd0_flags;
  44 static bool stdio_in_use;
  45 static bool stdio_allow_signal;
  46 static bool stdio_echo_state;
  47
  48 static void term_exit(void)
  49 {
  50     if (stdio_in_use) {
  51         tcsetattr(0, TCSANOW, &oldtty);
  52         fcntl(0, F_SETFL, old_fd0_flags);
  53     }
  54 }
  55
  56 static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)
  57 {
  58     struct termios tty;
  59
  60     stdio_echo_state = echo;
  61     tty = oldtty;
  62     if (!echo) {
  63         tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
  64                          | INLCR | IGNCR | ICRNL | IXON);
  65         tty.c_oflag |= OPOST;
  66         tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
  67         tty.c_cflag &= ~(CSIZE | PARENB);
  68         tty.c_cflag |= CS8;
  69         tty.c_cc[VMIN] = 1;
  70         tty.c_cc[VTIME] = 0;
  71     }
  72     if (!stdio_allow_signal) {
  73         tty.c_lflag &= ~ISIG;
  74     }
  75
  76     tcsetattr(0, TCSANOW, &tty);
  77 }
  78
  79 static void term_stdio_handler(int sig)
  80 {
  81     /* restore echo after resume from suspend. */
  82     qemu_chr_set_echo_stdio(NULL, stdio_echo_state);
  83 }
  84
  85 static void qemu_chr_open_stdio(Chardev *chr,
  86                                 ChardevBackend *backend,
  87                                 bool *be_opened,
  88                                 Error **errp)
  89 {
  90     ChardevStdio *opts = backend->u.stdio.data;
  91     struct sigaction act;
  92
  93     if (is_daemonized()) {
  94         error_setg(errp, "cannot use stdio with -daemonize");
  95         return;
  96     }
  97
  98     if (stdio_in_use) {
  99         error_setg(errp, "cannot use stdio by multiple character devices");
 100         return;
 101     }
 102
 103     stdio_in_use = true;
 104     old_fd0_flags = fcntl(0, F_GETFL);
 105     tcgetattr(0, &oldtty);
 106     if (!g_unix_set_fd_nonblocking(0, true, NULL)) {
 107         error_setg_errno(errp, errno, "Failed to set FD nonblocking");
 108         return;
 109     }
 110     atexit(term_exit);
 111
 112     memset(&act, 0, sizeof(act));
 113     act.sa_handler = term_stdio_handler;
 114     sigaction(SIGCONT, &act, NULL);
 115
 116     qemu_chr_open_fd(chr, 0, 1);
 117
 118     stdio_allow_signal = !opts->has_signal || opts->signal;
 119     qemu_chr_set_echo_stdio(chr, false);
 120 }
 121 #endif
 122
 123 static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
 124                                  Error **errp)
 125 {
 126     ChardevStdio *stdio;
 127
 128     backend->type = CHARDEV_BACKEND_KIND_STDIO;
 129     stdio = backend->u.stdio.data = g_new0(ChardevStdio, 1);
 130     qemu_chr_parse_common(opts, qapi_ChardevStdio_base(stdio));
 131     stdio->has_signal = true;
 132     stdio->signal = qemu_opt_get_bool(opts, "signal", true);
 133 }
 134
 135 static void char_stdio_class_init(ObjectClass *oc, void *data)
 136 {
 137     ChardevClass *cc = CHARDEV_CLASS(oc);
 138
 139     cc->parse = qemu_chr_parse_stdio;
 140 #ifndef _WIN32
 141     cc->open = qemu_chr_open_stdio;
 142     cc->chr_set_echo = qemu_chr_set_echo_stdio;
 143 #endif
 144 }
 145
 146 static void char_stdio_finalize(Object *obj)
 147 {
 148 #ifndef _WIN32
 149     term_exit();
 150 #endif
 151 }
 152
 153 static const TypeInfo char_stdio_type_info = {
 154     .name = TYPE_CHARDEV_STDIO,
 155 #ifdef _WIN32
 156     .parent = TYPE_CHARDEV_WIN_STDIO,
 157 #else
 158     .parent = TYPE_CHARDEV_FD,
 159 #endif
 160     .instance_finalize = char_stdio_finalize,
 161     .class_init = char_stdio_class_init,
 162 };
 163
 164 static void register_types(void)
 165 {
 166     type_register_static(&char_stdio_type_info);
 167 }
 168
 169 type_init(register_types);