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/module.h"
  28 #include "qemu/option.h"
  29 #include "chardev/char.h"
  30 #include "sysemu/block-backend.h"
  31 #include "sysemu/sysemu.h"
  32 #include "chardev/char-mux.h"
  33
  34 /* MUX driver for serial I/O splitting */
  35
  36 /* Called with chr_write_lock held.  */
  37 static int mux_chr_write(Chardev *chr, const uint8_t *buf, int len)
  38 {
  39     MuxChardev *d = MUX_CHARDEV(chr);
  40     int ret;
  41     if (!d->timestamps) {
  42         ret = qemu_chr_fe_write(&d->chr, buf, len);
  43     } else {
  44         int i;
  45
  46         ret = 0;
  47         for (i = 0; i < len; i++) {
  48             if (d->linestart) {
  49                 char buf1[64];
  50                 int64_t ti;
  51                 int secs;
  52
  53                 ti = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
  54                 if (d->timestamps_start == -1) {
  55                     d->timestamps_start = ti;
  56                 }
  57                 ti -= d->timestamps_start;
  58                 secs = ti / 1000;
  59                 snprintf(buf1, sizeof(buf1),
  60                          "[%02d:%02d:%02d.%03d] ",
  61                          secs / 3600,
  62                          (secs / 60) % 60,
  63                          secs % 60,
  64                          (int)(ti % 1000));
  65                 /* XXX this blocks entire thread. Rewrite to use
  66                  * qemu_chr_fe_write and background I/O callbacks */
  67                 qemu_chr_fe_write_all(&d->chr,
  68                                       (uint8_t *)buf1, strlen(buf1));
  69                 d->linestart = 0;
  70             }
  71             ret += qemu_chr_fe_write(&d->chr, buf + i, 1);
  72             if (buf[i] == '\n') {
  73                 d->linestart = 1;
  74             }
  75         }
  76     }
  77     return ret;
  78 }
  79
  80 static const char * const mux_help[] = {
  81     "% h    print this help\n\r",
  82     "% x    exit emulator\n\r",
  83     "% s    save disk data back to file (if -snapshot)\n\r",
  84     "% t    toggle console timestamps\n\r",
  85     "% b    send break (magic sysrq)\n\r",
  86     "% c    switch between console and monitor\n\r",
  87     "% %  sends %\n\r",
  88     NULL
  89 };
  90
  91 int term_escape_char = 0x01; /* ctrl-a is used for escape */
  92 static void mux_print_help(Chardev *chr)
  93 {
  94     int i, j;
  95     char ebuf[15] = "Escape-Char";
  96     char cbuf[50] = "\n\r";
  97
  98     if (term_escape_char > 0 && term_escape_char < 26) {
  99         snprintf(cbuf, sizeof(cbuf), "\n\r");
 100         snprintf(ebuf, sizeof(ebuf), "C-%c", term_escape_char - 1 + 'a');
 101     } else {
 102         snprintf(cbuf, sizeof(cbuf),
 103                  "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r",
 104                  term_escape_char);
 105     }
 106     /* XXX this blocks entire thread. Rewrite to use
 107      * qemu_chr_fe_write and background I/O callbacks */
 108     qemu_chr_write_all(chr, (uint8_t *)cbuf, strlen(cbuf));
 109     for (i = 0; mux_help[i] != NULL; i++) {
 110         for (j = 0; mux_help[i][j] != '\0'; j++) {
 111             if (mux_help[i][j] == '%') {
 112                 qemu_chr_write_all(chr, (uint8_t *)ebuf, strlen(ebuf));
 113             } else {
 114                 qemu_chr_write_all(chr, (uint8_t *)&mux_help[i][j], 1);
 115             }
 116         }
 117     }
 118 }
 119
 120 static void mux_chr_send_event(MuxChardev *d, int mux_nr, int event)
 121 {
 122     CharBackend *be = d->backends[mux_nr];
 123
 124     if (be && be->chr_event) {
 125         be->chr_event(be->opaque, event);
 126     }
 127 }
 128
 129 static void mux_chr_be_event(Chardev *chr, int event)
 130 {
 131     MuxChardev *d = MUX_CHARDEV(chr);
 132
 133     if (d->focus != -1) {
 134         mux_chr_send_event(d, d->focus, event);
 135     }
 136 }
 137
 138 static int mux_proc_byte(Chardev *chr, MuxChardev *d, int ch)
 139 {
 140     if (d->term_got_escape) {
 141         d->term_got_escape = 0;
 142         if (ch == term_escape_char) {
 143             goto send_char;
 144         }
 145         switch (ch) {
 146         case '?':
 147         case 'h':
 148             mux_print_help(chr);
 149             break;
 150         case 'x':
 151             {
 152                  const char *term =  "QEMU: Terminated\n\r";
 153                  qemu_chr_write_all(chr, (uint8_t *)term, strlen(term));
 154                  exit(0);
 155                  break;
 156             }
 157         case 's':
 158             blk_commit_all();
 159             break;
 160         case 'b':
 161             qemu_chr_be_event(chr, CHR_EVENT_BREAK);
 162             break;
 163         case 'c':
 164             assert(d->mux_cnt > 0); /* handler registered with first fe */
 165             /* Switch to the next registered device */
 166             mux_set_focus(chr, (d->focus + 1) % d->mux_cnt);
 167             break;
 168         case 't':
 169             d->timestamps = !d->timestamps;
 170             d->timestamps_start = -1;
 171             d->linestart = 0;
 172             break;
 173         }
 174     } else if (ch == term_escape_char) {
 175         d->term_got_escape = 1;
 176     } else {
 177     send_char:
 178         return 1;
 179     }
 180     return 0;
 181 }
 182
 183 static void mux_chr_accept_input(Chardev *chr)
 184 {
 185     MuxChardev *d = MUX_CHARDEV(chr);
 186     int m = d->focus;
 187     CharBackend *be = d->backends[m];
 188
 189     while (be && d->prod[m] != d->cons[m] &&
 190            be->chr_can_read && be->chr_can_read(be->opaque)) {
 191         be->chr_read(be->opaque,
 192                      &d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1);
 193     }
 194 }
 195
 196 static int mux_chr_can_read(void *opaque)
 197 {
 198     MuxChardev *d = MUX_CHARDEV(opaque);
 199     int m = d->focus;
 200     CharBackend *be = d->backends[m];
 201
 202     if ((d->prod[m] - d->cons[m]) < MUX_BUFFER_SIZE) {
 203         return 1;
 204     }
 205
 206     if (be && be->chr_can_read) {
 207         return be->chr_can_read(be->opaque);
 208     }
 209
 210     return 0;
 211 }
 212
 213 static void mux_chr_read(void *opaque, const uint8_t *buf, int size)
 214 {
 215     Chardev *chr = CHARDEV(opaque);
 216     MuxChardev *d = MUX_CHARDEV(opaque);
 217     int m = d->focus;
 218     CharBackend *be = d->backends[m];
 219     int i;
 220
 221     mux_chr_accept_input(opaque);
 222
 223     for (i = 0; i < size; i++)
 224         if (mux_proc_byte(chr, d, buf[i])) {
 225             if (d->prod[m] == d->cons[m] &&
 226                 be && be->chr_can_read &&
 227                 be->chr_can_read(be->opaque)) {
 228                 be->chr_read(be->opaque, &buf[i], 1);
 229             } else {
 230                 d->buffer[m][d->prod[m]++ & MUX_BUFFER_MASK] = buf[i];
 231             }
 232         }
 233 }
 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 (!machine_init_done) {
 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 static void mux_chr_update_read_handlers(Chardev *chr)
 283 {
 284     MuxChardev *d = MUX_CHARDEV(chr);
 285
 286     /* Fix up the real driver with mux routines */
 287     qemu_chr_fe_set_handlers_full(&d->chr,
 288                                   mux_chr_can_read,
 289                                   mux_chr_read,
 290                                   mux_chr_event,
 291                                   NULL,
 292                                   chr,
 293                                   chr->gcontext, true, false);
 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     chr->be = d->backends[focus];
 309     mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_IN);
 310 }
 311
 312 static void qemu_chr_open_mux(Chardev *chr,
 313                               ChardevBackend *backend,
 314                               bool *be_opened,
 315                               Error **errp)
 316 {
 317     ChardevMux *mux = backend->u.mux.data;
 318     Chardev *drv;
 319     MuxChardev *d = MUX_CHARDEV(chr);
 320
 321     drv = qemu_chr_find(mux->chardev);
 322     if (drv == NULL) {
 323         error_setg(errp, "mux: base chardev %s not found", mux->chardev);
 324         return;
 325     }
 326
 327     d->focus = -1;
 328     /* only default to opened state if we've realized the initial
 329      * set of muxes
 330      */
 331     *be_opened = machine_init_done;
 332     qemu_chr_fe_init(&d->chr, drv, errp);
 333 }
 334
 335 static void qemu_chr_parse_mux(QemuOpts *opts, ChardevBackend *backend,
 336                                Error **errp)
 337 {
 338     const char *chardev = qemu_opt_get(opts, "chardev");
 339     ChardevMux *mux;
 340
 341     if (chardev == NULL) {
 342         error_setg(errp, "chardev: mux: no chardev given");
 343         return;
 344     }
 345     backend->type = CHARDEV_BACKEND_KIND_MUX;
 346     mux = backend->u.mux.data = g_new0(ChardevMux, 1);
 347     qemu_chr_parse_common(opts, qapi_ChardevMux_base(mux));
 348     mux->chardev = g_strdup(chardev);
 349 }
 350
 351 /**
 352  * Called after processing of default and command-line-specified
 353  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
 354  * to a mux chardev. This is done here to ensure that
 355  * output/prompts/banners are only displayed for the FE that has
 356  * focus when initial command-line processing/machine init is
 357  * completed.
 358  *
 359  * After this point, any new FE attached to any new or existing
 360  * mux will receive CHR_EVENT_OPENED notifications for the BE
 361  * immediately.
 362  */
 363 static int open_muxes(Chardev *chr)
 364 {
 365     /* send OPENED to all already-attached FEs */
 366     mux_chr_send_all_event(chr, CHR_EVENT_OPENED);
 367     /*
 368      * mark mux as OPENED so any new FEs will immediately receive
 369      * OPENED event
 370      */
 371     chr->be_open = 1;
 372
 373     return 0;
 374 }
 375
 376 static void char_mux_class_init(ObjectClass *oc, void *data)
 377 {
 378     ChardevClass *cc = CHARDEV_CLASS(oc);
 379
 380     cc->parse = qemu_chr_parse_mux;
 381     cc->open = qemu_chr_open_mux;
 382     cc->chr_write = mux_chr_write;
 383     cc->chr_accept_input = mux_chr_accept_input;
 384     cc->chr_add_watch = mux_chr_add_watch;
 385     cc->chr_be_event = mux_chr_be_event;
 386     cc->chr_machine_done = open_muxes;
 387     cc->chr_update_read_handler = mux_chr_update_read_handlers;
 388 }
 389
 390 static const TypeInfo char_mux_type_info = {
 391     .name = TYPE_CHARDEV_MUX,
 392     .parent = TYPE_CHARDEV,
 393     .class_init = char_mux_class_init,
 394     .instance_size = sizeof(MuxChardev),
 395     .instance_finalize = char_mux_finalize,
 396 };
 397
 398 static void register_types(void)
 399 {
 400     type_register_static(&char_mux_type_info);
 401 }
 402
 403 type_init(register_types);