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 "chardev/char-mux.h"
  31
  32 /* MUX driver for serial I/O splitting */
  33
  34 /* Called with chr_write_lock held.  */
  35 static int mux_chr_write(Chardev *chr, const uint8_t *buf, int len)
  36 {
  37     MuxChardev *d = MUX_CHARDEV(chr);
  38     int ret;
  39     if (!d->timestamps) {
  40         ret = qemu_chr_fe_write(&d->chr, buf, len);
  41     } else {
  42         int i;
  43
  44         ret = 0;
  45         for (i = 0; i < len; i++) {
  46             if (d->linestart) {
  47                 char buf1[64];
  48                 int64_t ti;
  49                 int secs;
  50
  51                 ti = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  52                 if (d->timestamps_start == -1) {
  53                     d->timestamps_start = ti;
  54                 }
  55                 ti -= d->timestamps_start;
  56                 secs = ti / 1000;
  57                 snprintf(buf1, sizeof(buf1),
  58                          "[%02d:%02d:%02d.%03d] ",
  59                          secs / 3600,
  60                          (secs / 60) % 60,
  61                          secs % 60,
  62                          (int)(ti % 1000));
  63                 /* XXX this blocks entire thread. Rewrite to use
  64                  * qemu_chr_fe_write and background I/O callbacks */
  65                 qemu_chr_fe_write_all(&d->chr,
  66                                       (uint8_t *)buf1, strlen(buf1));
  67                 d->linestart = 0;
  68             }
  69             ret += qemu_chr_fe_write(&d->chr, buf + i, 1);
  70             if (buf[i] == '\n') {
  71                 d->linestart = 1;
  72             }
  73         }
  74     }
  75     return ret;
  76 }
  77
  78 static const char * const mux_help[] = {
  79     "% h    print this help\n\r",
  80     "% x    exit emulator\n\r",
  81     "% s    save disk data back to file (if -snapshot)\n\r",
  82     "% t    toggle console timestamps\n\r",
  83     "% b    send break (magic sysrq)\n\r",
  84     "% c    switch between console and monitor\n\r",
  85     "% %  sends %\n\r",
  86     NULL
  87 };
  88
  89 int term_escape_char = 0x01; /* ctrl-a is used for escape */
  90 static void mux_print_help(Chardev *chr)
  91 {
  92     int i, j;
  93     char ebuf[15] = "Escape-Char";
  94     char cbuf[50] = "\n\r";
  95
  96     if (term_escape_char > 0 && term_escape_char < 26) {
  97         snprintf(cbuf, sizeof(cbuf), "\n\r");
  98         snprintf(ebuf, sizeof(ebuf), "C-%c", term_escape_char - 1 + 'a');
  99     } else {
 100         snprintf(cbuf, sizeof(cbuf),
 101                  "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r",
 102                  term_escape_char);
 103     }
 104     /* XXX this blocks entire thread. Rewrite to use
 105      * qemu_chr_fe_write and background I/O callbacks */
 106     qemu_chr_write_all(chr, (uint8_t *)cbuf, strlen(cbuf));
 107     for (i = 0; mux_help[i] != NULL; i++) {
 108         for (j = 0; mux_help[i][j] != '\0'; j++) {
 109             if (mux_help[i][j] == '%') {
 110                 qemu_chr_write_all(chr, (uint8_t *)ebuf, strlen(ebuf));
 111             } else {
 112                 qemu_chr_write_all(chr, (uint8_t *)&mux_help[i][j], 1);
 113             }
 114         }
 115     }
 116 }
 117
 118 static void mux_chr_send_event(MuxChardev *d, int mux_nr, int event)
 119 {
 120     CharBackend *be = d->backends[mux_nr];
 121
 122     if (be && be->chr_event) {
 123         be->chr_event(be->opaque, event);
 124     }
 125 }
 126
 127 static void mux_chr_be_event(Chardev *chr, int event)
 128 {
 129     MuxChardev *d = MUX_CHARDEV(chr);
 130
 131     if (d->focus != -1) {
 132         mux_chr_send_event(d, d->focus, event);
 133     }
 134 }
 135
 136 static int mux_proc_byte(Chardev *chr, MuxChardev *d, int ch)
 137 {
 138     if (d->term_got_escape) {
 139         d->term_got_escape = 0;
 140         if (ch == term_escape_char) {
 141             goto send_char;
 142         }
 143         switch (ch) {
 144         case '?':
 145         case 'h':
 146             mux_print_help(chr);
 147             break;
 148         case 'x':
 149             {
 150                  const char *term =  "QEMU: Terminated\n\r";
 151                  qemu_chr_write_all(chr, (uint8_t *)term, strlen(term));
 152                  exit(0);
 153                  break;
 154             }
 155         case 's':
 156             blk_commit_all();
 157             break;
 158         case 'b':
 159             qemu_chr_be_event(chr, CHR_EVENT_BREAK);
 160             break;
 161         case 'c':
 162             assert(d->mux_cnt > 0); /* handler registered with first fe */
 163             /* Switch to the next registered device */
 164             mux_set_focus(chr, (d->focus + 1) % d->mux_cnt);
 165             break;
 166         case 't':
 167             d->timestamps = !d->timestamps;
 168             d->timestamps_start = -1;
 169             d->linestart = 0;
 170             break;
 171         }
 172     } else if (ch == term_escape_char) {
 173         d->term_got_escape = 1;
 174     } else {
 175     send_char:
 176         return 1;
 177     }
 178     return 0;
 179 }
 180
 181 static void mux_chr_accept_input(Chardev *chr)
 182 {
 183     MuxChardev *d = MUX_CHARDEV(chr);
 184     int m = d->focus;
 185     CharBackend *be = d->backends[m];
 186
 187     while (be && d->prod[m] != d->cons[m] &&
 188            be->chr_can_read && be->chr_can_read(be->opaque)) {
 189         be->chr_read(be->opaque,
 190                      &d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1);
 191     }
 192 }
 193
 194 static int mux_chr_can_read(void *opaque)
 195 {
 196     MuxChardev *d = MUX_CHARDEV(opaque);
 197     int m = d->focus;
 198     CharBackend *be = d->backends[m];
 199
 200     if ((d->prod[m] - d->cons[m]) < MUX_BUFFER_SIZE) {
 201         return 1;
 202     }
 203
 204     if (be && be->chr_can_read) {
 205         return be->chr_can_read(be->opaque);
 206     }
 207
 208     return 0;
 209 }
 210
 211 static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
 212 {
 213     Chardev *chr = CHARDEV(opaque);
 214     MuxChardev *d = MUX_CHARDEV(opaque);
 215     int m = d->focus;
 216     CharBackend *be = d->backends[m];
 217     int i;
 218
 219     mux_chr_accept_input(opaque);
 220
 221     for (i = 0; i < size; i++)
 222         if (mux_proc_byte(chr, d, buf[i])) {
 223             if (d->prod[m] == d->cons[m] &&
 224                 be && be->chr_can_read &&
 225                 be->chr_can_read(be->opaque)) {
 226                 be->chr_read(be->opaque, &buf[i], 1);
 227             } else {
 228                 d->buffer[m][d->prod[m]++ & MUX_BUFFER_MASK] = buf[i];
 229             }
 230         }
 231 }
 232
 233 bool muxes_realized;
 234
 235 void mux_chr_send_all_event(Chardev *chr, int event)
 236 {
 237     MuxChardev *d = MUX_CHARDEV(chr);
 238     int i;
 239
 240     if (!muxes_realized) {
 241         return;
 242     }
 243
 244     /* Send the event to all registered listeners */
 245     for (i = 0; i < d->mux_cnt; i++) {
 246         mux_chr_send_event(d, i, event);
 247     }
 248 }
 249
 250 static void mux_chr_event(void *opaque, int event)
 251 {
 252     mux_chr_send_all_event(CHARDEV(opaque), event);
 253 }
 254
 255 static GSource *mux_chr_add_watch(Chardev *s, GIOCondition cond)
 256 {
 257     MuxChardev *d = MUX_CHARDEV(s);
 258     Chardev *chr = qemu_chr_fe_get_driver(&d->chr);
 259     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
 260
 261     if (!cc->chr_add_watch) {
 262         return NULL;
 263     }
 264
 265     return cc->chr_add_watch(chr, cond);
 266 }
 267
 268 static void char_mux_finalize(Object *obj)
 269 {
 270     MuxChardev *d = MUX_CHARDEV(obj);
 271     int i;
 272
 273     for (i = 0; i < d->mux_cnt; i++) {
 274         CharBackend *be = d->backends[i];
 275         if (be) {
 276             be->chr = NULL;
 277         }
 278     }
 279     qemu_chr_fe_deinit(&d->chr, false);
 280 }
 281
 282 void mux_chr_set_handlers(Chardev *chr, GMainContext *context)
 283 {
 284     MuxChardev *d = MUX_CHARDEV(chr);
 285
 286     /* Fix up the real driver with mux routines */
 287     qemu_chr_fe_set_handlers(&d->chr,
 288                              mux_chr_can_read,
 289                              mux_chr_read,
 290                              mux_chr_event,
 291                              NULL,
 292                              chr,
 293                              context, true);
 294 }
 295
 296 void mux_set_focus(Chardev *chr, int focus)
 297 {
 298     MuxChardev *d = MUX_CHARDEV(chr);
 299
 300     assert(focus >= 0);
 301     assert(focus < d->mux_cnt);
 302
 303     if (d->focus != -1) {
 304         mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_OUT);
 305     }
 306
 307     d->focus = 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 = muxes_realized;
 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 static void char_mux_class_init(ObjectClass *oc, void *data)
 351 {
 352     ChardevClass *cc = CHARDEV_CLASS(oc);
 353
 354     cc->parse = qemu_chr_parse_mux;
 355     cc->open = qemu_chr_open_mux;
 356     cc->chr_write = mux_chr_write;
 357     cc->chr_accept_input = mux_chr_accept_input;
 358     cc->chr_add_watch = mux_chr_add_watch;
 359     cc->chr_be_event = mux_chr_be_event;
 360 }
 361
 362 static const TypeInfo char_mux_type_info = {
 363     .name = TYPE_CHARDEV_MUX,
 364     .parent = TYPE_CHARDEV,
 365     .class_init = char_mux_class_init,
 366     .instance_size = sizeof(MuxChardev),
 367     .instance_finalize = char_mux_finalize,
 368 };
 369
 370 static void register_types(void)
 371 {
 372     type_register_static(&char_mux_type_info);
 373 }
 374
 375 type_init(register_types);