chardev/char-mux.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 #include "qemu/osdep.h"
  25 #include "qapi/error.h"
  26 #include "qemu-common.h"
  27 #include "chardev/char.h"
  28 #include "sysemu/block-backend.h"
  29 #include "chardev/char-mux.h"
  30
  31 /* MUX driver for serial I/O splitting */
  32
  33 /* Called with chr_write_lock held.  */
  34 static int mux_chr_write(Chardev *chr, const uint8_t *buf, int len)
  35 {
  36     MuxChardev *d = MUX_CHARDEV(chr);
  37     int ret;
  38     if (!d->timestamps) {
  39         ret = qemu_chr_fe_write(&d->chr, buf, len);
  40     } else {
  41         int i;
  42
  43         ret = 0;
  44         for (i = 0; i < len; i++) {
  45             if (d->linestart) {
  46                 char buf1[64];
  47                 int64_t ti;
  48                 int secs;
  49
  50                 ti = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  51                 if (d->timestamps_start == -1) {
  52                     d->timestamps_start = ti;
  53                 }
  54                 ti -= d->timestamps_start;
  55                 secs = ti / 1000;
  56                 snprintf(buf1, sizeof(buf1),
  57                          "[%02d:%02d:%02d.%03d] ",
  58                          secs / 3600,
  59                          (secs / 60) % 60,
  60                          secs % 60,
  61                          (int)(ti % 1000));
  62                 /* XXX this blocks entire thread. Rewrite to use
  63                  * qemu_chr_fe_write and background I/O callbacks */
  64                 qemu_chr_fe_write_all(&d->chr,
  65                                       (uint8_t *)buf1, strlen(buf1));
  66                 d->linestart = 0;
  67             }
  68             ret += qemu_chr_fe_write(&d->chr, buf + i, 1);
  69             if (buf[i] == '\n') {
  70                 d->linestart = 1;
  71             }
  72         }
  73     }
  74     return ret;
  75 }
  76
  77 static const char * const mux_help[] = {
  78     "% h    print this help\n\r",
  79     "% x    exit emulator\n\r",
  80     "% s    save disk data back to file (if -snapshot)\n\r",
  81     "% t    toggle console timestamps\n\r",
  82     "% b    send break (magic sysrq)\n\r",
  83     "% c    switch between console and monitor\n\r",
  84     "% %  sends %\n\r",
  85     NULL
  86 };
  87
  88 int term_escape_char = 0x01; /* ctrl-a is used for escape */
  89 static void mux_print_help(Chardev *chr)
  90 {
  91     int i, j;
  92     char ebuf[15] = "Escape-Char";
  93     char cbuf[50] = "\n\r";
  94
  95     if (term_escape_char > 0 && term_escape_char < 26) {
  96         snprintf(cbuf, sizeof(cbuf), "\n\r");
  97         snprintf(ebuf, sizeof(ebuf), "C-%c", term_escape_char - 1 + 'a');
  98     } else {
  99         snprintf(cbuf, sizeof(cbuf),
 100                  "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r",
 101                  term_escape_char);
 102     }
 103     /* XXX this blocks entire thread. Rewrite to use
 104      * qemu_chr_fe_write and background I/O callbacks */
 105     qemu_chr_write_all(chr, (uint8_t *)cbuf, strlen(cbuf));
 106     for (i = 0; mux_help[i] != NULL; i++) {
 107         for (j = 0; mux_help[i][j] != '\0'; j++) {
 108             if (mux_help[i][j] == '%') {
 109                 qemu_chr_write_all(chr, (uint8_t *)ebuf, strlen(ebuf));
 110             } else {
 111                 qemu_chr_write_all(chr, (uint8_t *)&mux_help[i][j], 1);
 112             }
 113         }
 114     }
 115 }
 116
 117 static void mux_chr_send_event(MuxChardev *d, int mux_nr, int event)
 118 {
 119     CharBackend *be = d->backends[mux_nr];
 120
 121     if (be && be->chr_event) {
 122         be->chr_event(be->opaque, event);
 123     }
 124 }
 125
 126 static void mux_chr_be_event(Chardev *chr, int event)
 127 {
 128     MuxChardev *d = MUX_CHARDEV(chr);
 129
 130     if (d->focus != -1) {
 131         mux_chr_send_event(d, d->focus, event);
 132     }
 133 }
 134
 135 static int mux_proc_byte(Chardev *chr, MuxChardev *d, int ch)
 136 {
 137     if (d->term_got_escape) {
 138         d->term_got_escape = 0;
 139         if (ch == term_escape_char) {
 140             goto send_char;
 141         }
 142         switch (ch) {
 143         case '?':
 144         case 'h':
 145             mux_print_help(chr);
 146             break;
 147         case 'x':
 148             {
 149                  const char *term =  "QEMU: Terminated\n\r";
 150                  qemu_chr_write_all(chr, (uint8_t *)term, strlen(term));
 151                  exit(0);
 152                  break;
 153             }
 154         case 's':
 155             blk_commit_all();
 156             break;
 157         case 'b':
 158             qemu_chr_be_event(chr, CHR_EVENT_BREAK);
 159             break;
 160         case 'c':
 161             assert(d->mux_cnt > 0); /* handler registered with first fe */
 162             /* Switch to the next registered device */
 163             mux_set_focus(chr, (d->focus + 1) % d->mux_cnt);
 164             break;
 165         case 't':
 166             d->timestamps = !d->timestamps;
 167             d->timestamps_start = -1;
 168             d->linestart = 0;
 169             break;
 170         }
 171     } else if (ch == term_escape_char) {
 172         d->term_got_escape = 1;
 173     } else {
 174     send_char:
 175         return 1;
 176     }
 177     return 0;
 178 }
 179
 180 static void mux_chr_accept_input(Chardev *chr)
 181 {
 182     MuxChardev *d = MUX_CHARDEV(chr);
 183     int m = d->focus;
 184     CharBackend *be = d->backends[m];
 185
 186     while (be && d->prod[m] != d->cons[m] &&
 187            be->chr_can_read && be->chr_can_read(be->opaque)) {
 188         be->chr_read(be->opaque,
 189                      &d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1);
 190     }
 191 }
 192
 193 static int mux_chr_can_read(void *opaque)
 194 {
 195     MuxChardev *d = MUX_CHARDEV(opaque);
 196     int m = d->focus;
 197     CharBackend *be = d->backends[m];
 198
 199     if ((d->prod[m] - d->cons[m]) < MUX_BUFFER_SIZE) {
 200         return 1;
 201     }
 202
 203     if (be && be->chr_can_read) {
 204         return be->chr_can_read(be->opaque);
 205     }
 206
 207     return 0;
 208 }
 209
 210 static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
 211 {
 212     Chardev *chr = CHARDEV(opaque);
 213     MuxChardev *d = MUX_CHARDEV(opaque);
 214     int m = d->focus;
 215     CharBackend *be = d->backends[m];
 216     int i;
 217
 218     mux_chr_accept_input(opaque);
 219
 220     for (i = 0; i < size; i++)
 221         if (mux_proc_byte(chr, d, buf[i])) {
 222             if (d->prod[m] == d->cons[m] &&
 223                 be && be->chr_can_read &&
 224                 be->chr_can_read(be->opaque)) {
 225                 be->chr_read(be->opaque, &buf[i], 1);
 226             } else {
 227                 d->buffer[m][d->prod[m]++ & MUX_BUFFER_MASK] = buf[i];
 228             }
 229         }
 230 }
 231
 232 bool muxes_realized;
 233
 234 void mux_chr_send_all_event(Chardev *chr, int event)
 235 {
 236     MuxChardev *d = MUX_CHARDEV(chr);
 237     int i;
 238
 239     if (!muxes_realized) {
 240         return;
 241     }
 242
 243     /* Send the event to all registered listeners */
 244     for (i = 0; i < d->mux_cnt; i++) {
 245         mux_chr_send_event(d, i, event);
 246     }
 247 }
 248
 249 static void mux_chr_event(void *opaque, int event)
 250 {
 251     mux_chr_send_all_event(CHARDEV(opaque), event);
 252 }
 253
 254 static GSource *mux_chr_add_watch(Chardev *s, GIOCondition cond)
 255 {
 256     MuxChardev *d = MUX_CHARDEV(s);
 257     Chardev *chr = qemu_chr_fe_get_driver(&d->chr);
 258     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
 259
 260     if (!cc->chr_add_watch) {
 261         return NULL;
 262     }
 263
 264     return cc->chr_add_watch(chr, cond);
 265 }
 266
 267 static void char_mux_finalize(Object *obj)
 268 {
 269     MuxChardev *d = MUX_CHARDEV(obj);
 270     int i;
 271
 272     for (i = 0; i < d->mux_cnt; i++) {
 273         CharBackend *be = d->backends[i];
 274         if (be) {
 275             be->chr = NULL;
 276         }
 277     }
 278     qemu_chr_fe_deinit(&d->chr, false);
 279 }
 280
 281 void mux_chr_set_handlers(Chardev *chr, GMainContext *context)
 282 {
 283     MuxChardev *d = MUX_CHARDEV(chr);
 284
 285     /* Fix up the real driver with mux routines */
 286     qemu_chr_fe_set_handlers(&d->chr,
 287                              mux_chr_can_read,
 288                              mux_chr_read,
 289                              mux_chr_event,
 290                              NULL,
 291                              chr,
 292                              context, true);
 293 }
 294
 295 void mux_set_focus(Chardev *chr, int focus)
 296 {
 297     MuxChardev *d = MUX_CHARDEV(chr);
 298
 299     assert(focus >= 0);
 300     assert(focus < d->mux_cnt);
 301
 302     if (d->focus != -1) {
 303         mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_OUT);
 304     }
 305
 306     d->focus = focus;
 307     mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_IN);
 308 }
 309
 310 static void qemu_chr_open_mux(Chardev *chr,
 311                               ChardevBackend *backend,
 312                               bool *be_opened,
 313                               Error **errp)
 314 {
 315     ChardevMux *mux = backend->u.mux.data;
 316     Chardev *drv;
 317     MuxChardev *d = MUX_CHARDEV(chr);
 318
 319     drv = qemu_chr_find(mux->chardev);
 320     if (drv == NULL) {
 321         error_setg(errp, "mux: base chardev %s not found", mux->chardev);
 322         return;
 323     }
 324
 325     d->focus = -1;
 326     /* only default to opened state if we've realized the initial
 327      * set of muxes
 328      */
 329     *be_opened = muxes_realized;
 330     qemu_chr_fe_init(&d->chr, drv, errp);
 331 }
 332
 333 static void qemu_chr_parse_mux(QemuOpts *opts, ChardevBackend *backend,
 334                                Error **errp)
 335 {
 336     const char *chardev = qemu_opt_get(opts, "chardev");
 337     ChardevMux *mux;
 338
 339     if (chardev == NULL) {
 340         error_setg(errp, "chardev: mux: no chardev given");
 341         return;
 342     }
 343     backend->type = CHARDEV_BACKEND_KIND_MUX;
 344     mux = backend->u.mux.data = g_new0(ChardevMux, 1);
 345     qemu_chr_parse_common(opts, qapi_ChardevMux_base(mux));
 346     mux->chardev = g_strdup(chardev);
 347 }
 348
 349 static void char_mux_class_init(ObjectClass *oc, void *data)
 350 {
 351     ChardevClass *cc = CHARDEV_CLASS(oc);
 352
 353     cc->parse = qemu_chr_parse_mux;
 354     cc->open = qemu_chr_open_mux;
 355     cc->chr_write = mux_chr_write;
 356     cc->chr_accept_input = mux_chr_accept_input;
 357     cc->chr_add_watch = mux_chr_add_watch;
 358     cc->chr_be_event = mux_chr_be_event;
 359 }
 360
 361 static const TypeInfo char_mux_type_info = {
 362     .name = TYPE_CHARDEV_MUX,
 363     .parent = TYPE_CHARDEV,
 364     .class_init = char_mux_class_init,
 365     .instance_size = sizeof(MuxChardev),
 366     .instance_finalize = char_mux_finalize,
 367 };
 368
 369 static void register_types(void)
 370 {
 371     type_register_static(&char_mux_type_info);
 372 }
 373
 374 type_init(register_types);