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
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/option.h"
  28 #include "chardev/char.h"
  29 #include "sysemu/block-backend.h"
  30 #include "sysemu/sysemu.h"
  31 #include "chardev/char-mux.h"
  32
  33 /* MUX driver for serial I/O splitting */
  34
  35 /* Called with chr_write_lock held.  */
  36 static int mux_chr_write(Chardev *chr, const uint8_t *buf, int len)
  37 {
  38     MuxChardev *d = MUX_CHARDEV(chr);
  39     int ret;
  40     if (!d->timestamps) {
  41         ret = qemu_chr_fe_write(&d->chr, buf, len);
  42     } else {
  43         int i;
  44
  45         ret = 0;
  46         for (i = 0; i < len; i++) {
  47             if (d->linestart) {
  48                 char buf1[64];
  49                 int64_t ti;
  50                 int secs;
  51
  52                 ti = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  53                 if (d->timestamps_start == -1) {
  54                     d->timestamps_start = ti;
  55                 }
  56                 ti -= d->timestamps_start;
  57                 secs = ti / 1000;
  58                 snprintf(buf1, sizeof(buf1),
  59                          "[%02d:%02d:%02d.%03d] ",
  60                          secs / 3600,
  61                          (secs / 60) % 60,
  62                          secs % 60,
  63                          (int)(ti % 1000));
  64                 /* XXX this blocks entire thread. Rewrite to use
  65                  * qemu_chr_fe_write and background I/O callbacks */
  66                 qemu_chr_fe_write_all(&d->chr,
  67                                       (uint8_t *)buf1, strlen(buf1));
  68                 d->linestart = 0;
  69             }
  70             ret += qemu_chr_fe_write(&d->chr, buf + i, 1);
  71             if (buf[i] == '\n') {
  72                 d->linestart = 1;
  73             }
  74         }
  75     }
  76     return ret;
  77 }
  78
  79 static const char * const mux_help[] = {
  80     "% h    print this help\n\r",
  81     "% x    exit emulator\n\r",
  82     "% s    save disk data back to file (if -snapshot)\n\r",
  83     "% t    toggle console timestamps\n\r",
  84     "% b    send break (magic sysrq)\n\r",
  85     "% c    switch between console and monitor\n\r",
  86     "% %  sends %\n\r",
  87     NULL
  88 };
  89
  90 int term_escape_char = 0x01; /* ctrl-a is used for escape */
  91 static void mux_print_help(Chardev *chr)
  92 {
  93     int i, j;
  94     char ebuf[15] = "Escape-Char";
  95     char cbuf[50] = "\n\r";
  96
  97     if (term_escape_char > 0 && term_escape_char < 26) {
  98         snprintf(cbuf, sizeof(cbuf), "\n\r");
  99         snprintf(ebuf, sizeof(ebuf), "C-%c", term_escape_char - 1 + 'a');
 100     } else {
 101         snprintf(cbuf, sizeof(cbuf),
 102                  "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r",
 103                  term_escape_char);
 104     }
 105     /* XXX this blocks entire thread. Rewrite to use
 106      * qemu_chr_fe_write and background I/O callbacks */
 107     qemu_chr_write_all(chr, (uint8_t *)cbuf, strlen(cbuf));
 108     for (i = 0; mux_help[i] != NULL; i++) {
 109         for (j = 0; mux_help[i][j] != '\0'; j++) {
 110             if (mux_help[i][j] == '%') {
 111                 qemu_chr_write_all(chr, (uint8_t *)ebuf, strlen(ebuf));
 112             } else {
 113                 qemu_chr_write_all(chr, (uint8_t *)&mux_help[i][j], 1);
 114             }
 115         }
 116     }
 117 }
 118
 119 static void mux_chr_send_event(MuxChardev *d, int mux_nr, int event)
 120 {
 121     CharBackend *be = d->backends[mux_nr];
 122
 123     if (be && be->chr_event) {
 124         be->chr_event(be->opaque, event);
 125     }
 126 }
 127
 128 static void mux_chr_be_event(Chardev *chr, int event)
 129 {
 130     MuxChardev *d = MUX_CHARDEV(chr);
 131
 132     if (d->focus != -1) {
 133         mux_chr_send_event(d, d->focus, event);
 134     }
 135 }
 136
 137 static int mux_proc_byte(Chardev *chr, MuxChardev *d, int ch)
 138 {
 139     if (d->term_got_escape) {
 140         d->term_got_escape = 0;
 141         if (ch == term_escape_char) {
 142             goto send_char;
 143         }
 144         switch (ch) {
 145         case '?':
 146         case 'h':
 147             mux_print_help(chr);
 148             break;
 149         case 'x':
 150             {
 151                  const char *term =  "QEMU: Terminated\n\r";
 152                  qemu_chr_write_all(chr, (uint8_t *)term, strlen(term));
 153                  exit(0);
 154                  break;
 155             }
 156         case 's':
 157             blk_commit_all();
 158             break;
 159         case 'b':
 160             qemu_chr_be_event(chr, CHR_EVENT_BREAK);
 161             break;
 162         case 'c':
 163             assert(d->mux_cnt > 0); /* handler registered with first fe */
 164             /* Switch to the next registered device */
 165             mux_set_focus(chr, (d->focus + 1) % d->mux_cnt);
 166             break;
 167         case 't':
 168             d->timestamps = !d->timestamps;
 169             d->timestamps_start = -1;
 170             d->linestart = 0;
 171             break;
 172         }
 173     } else if (ch == term_escape_char) {
 174         d->term_got_escape = 1;
 175     } else {
 176     send_char:
 177         return 1;
 178     }
 179     return 0;
 180 }
 181
 182 static void mux_chr_accept_input(Chardev *chr)
 183 {
 184     MuxChardev *d = MUX_CHARDEV(chr);
 185     int m = d->focus;
 186     CharBackend *be = d->backends[m];
 187
 188     while (be && d->prod[m] != d->cons[m] &&
 189            be->chr_can_read && be->chr_can_read(be->opaque)) {
 190         be->chr_read(be->opaque,
 191                      &d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1);
 192     }
 193 }
 194
 195 static int mux_chr_can_read(void *opaque)
 196 {
 197     MuxChardev *d = MUX_CHARDEV(opaque);
 198     int m = d->focus;
 199     CharBackend *be = d->backends[m];
 200
 201     if ((d->prod[m] - d->cons[m]) < MUX_BUFFER_SIZE) {
 202         return 1;
 203     }
 204
 205     if (be && be->chr_can_read) {
 206         return be->chr_can_read(be->opaque);
 207     }
 208
 209     return 0;
 210 }
 211
 212 static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
 213 {
 214     Chardev *chr = CHARDEV(opaque);
 215     MuxChardev *d = MUX_CHARDEV(opaque);
 216     int m = d->focus;
 217     CharBackend *be = d->backends[m];
 218     int i;
 219
 220     mux_chr_accept_input(opaque);
 221
 222     for (i = 0; i < size; i++)
 223         if (mux_proc_byte(chr, d, buf[i])) {
 224             if (d->prod[m] == d->cons[m] &&
 225                 be && be->chr_can_read &&
 226                 be->chr_can_read(be->opaque)) {
 227                 be->chr_read(be->opaque, &buf[i], 1);
 228             } else {
 229                 d->buffer[m][d->prod[m]++ & MUX_BUFFER_MASK] = buf[i];
 230             }
 231         }
 232 }
 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 (!machine_init_done) {
 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 static void mux_chr_update_read_handlers(Chardev *chr)
 282 {
 283     MuxChardev *d = MUX_CHARDEV(chr);
 284
 285     /* Fix up the real driver with mux routines */
 286     qemu_chr_fe_set_handlers_full(&d->chr,
 287                                   mux_chr_can_read,
 288                                   mux_chr_read,
 289                                   mux_chr_event,
 290                                   NULL,
 291                                   chr,
 292                                   chr->gcontext, true, false);
 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     chr->be = d->backends[focus];
 308     mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_IN);
 309 }
 310
 311 static void qemu_chr_open_mux(Chardev *chr,
 312                               ChardevBackend *backend,
 313                               bool *be_opened,
 314                               Error **errp)
 315 {
 316     ChardevMux *mux = backend->u.mux.data;
 317     Chardev *drv;
 318     MuxChardev *d = MUX_CHARDEV(chr);
 319
 320     drv = qemu_chr_find(mux->chardev);
 321     if (drv == NULL) {
 322         error_setg(errp, "mux: base chardev %s not found", mux->chardev);
 323         return;
 324     }
 325
 326     d->focus = -1;
 327     /* only default to opened state if we've realized the initial
 328      * set of muxes
 329      */
 330     *be_opened = machine_init_done;
 331     qemu_chr_fe_init(&d->chr, drv, errp);
 332 }
 333
 334 static void qemu_chr_parse_mux(QemuOpts *opts, ChardevBackend *backend,
 335                                Error **errp)
 336 {
 337     const char *chardev = qemu_opt_get(opts, "chardev");
 338     ChardevMux *mux;
 339
 340     if (chardev == NULL) {
 341         error_setg(errp, "chardev: mux: no chardev given");
 342         return;
 343     }
 344     backend->type = CHARDEV_BACKEND_KIND_MUX;
 345     mux = backend->u.mux.data = g_new0(ChardevMux, 1);
 346     qemu_chr_parse_common(opts, qapi_ChardevMux_base(mux));
 347     mux->chardev = g_strdup(chardev);
 348 }
 349
 350 /**
 351  * Called after processing of default and command-line-specified
 352  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
 353  * to a mux chardev. This is done here to ensure that
 354  * output/prompts/banners are only displayed for the FE that has
 355  * focus when initial command-line processing/machine init is
 356  * completed.
 357  *
 358  * After this point, any new FE attached to any new or existing
 359  * mux will receive CHR_EVENT_OPENED notifications for the BE
 360  * immediately.
 361  */
 362 static int open_muxes(Chardev *chr)
 363 {
 364     /* send OPENED to all already-attached FEs */
 365     mux_chr_send_all_event(chr, CHR_EVENT_OPENED);
 366     /*
 367      * mark mux as OPENED so any new FEs will immediately receive
 368      * OPENED event
 369      */
 370     chr->be_open = 1;
 371
 372     return 0;
 373 }
 374
 375 static void char_mux_class_init(ObjectClass *oc, void *data)
 376 {
 377     ChardevClass *cc = CHARDEV_CLASS(oc);
 378
 379     cc->parse = qemu_chr_parse_mux;
 380     cc->open = qemu_chr_open_mux;
 381     cc->chr_write = mux_chr_write;
 382     cc->chr_accept_input = mux_chr_accept_input;
 383     cc->chr_add_watch = mux_chr_add_watch;
 384     cc->chr_be_event = mux_chr_be_event;
 385     cc->chr_machine_done = open_muxes;
 386     cc->chr_update_read_handler = mux_chr_update_read_handlers;
 387 }
 388
 389 static const TypeInfo char_mux_type_info = {
 390     .name = TYPE_CHARDEV_MUX,
 391     .parent = TYPE_CHARDEV,
 392     .class_init = char_mux_class_init,
 393     .instance_size = sizeof(MuxChardev),
 394     .instance_finalize = char_mux_finalize,
 395 };
 396
 397 static void register_types(void)
 398 {
 399     type_register_static(&char_mux_type_info);
 400 }
 401
 402 type_init(register_types);