| 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 "qemu/bitops.h" |
| 30 | #include "chardev/char.h" |
| 31 | #include "system/block-backend.h" |
| 32 | #include "qapi/qapi-commands-control.h" |
| 33 | #include "chardev-internal.h" |
| 34 | |
| 35 | /* MUX driver for serial I/O splitting */ |
| 36 | |
| 37 | /* |
| 38 | * Set to false by suspend_mux_open. Open events are delayed until |
| 39 | * resume_mux_open. Usually suspend_mux_open is called before |
| 40 | * command line processing and resume_mux_open afterwards. |
| 41 | */ |
| 42 | static bool muxes_opened = true; |
| 43 | |
| 44 | /* Called with chr_write_lock held. */ |
| 45 | static int mux_chr_write(Chardev *chr, const uint8_t *buf, int len) |
| 46 | { |
| 47 | MuxChardev *d = MUX_CHARDEV(chr); |
| 48 | int ret; |
| 49 | if (!d->timestamps) { |
| 50 | ret = qemu_chr_fe_write(&d->chr, buf, len); |
| 51 | } else { |
| 52 | int i; |
| 53 | |
| 54 | ret = 0; |
| 55 | for (i = 0; i < len; i++) { |
| 56 | if (d->linestart) { |
| 57 | char buf1[64]; |
| 58 | int64_t ti; |
| 59 | int secs; |
| 60 | |
| 61 | ti = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); |
| 62 | if (d->timestamps_start == -1) { |
| 63 | d->timestamps_start = ti; |
| 64 | } |
| 65 | ti -= d->timestamps_start; |
| 66 | secs = ti / 1000; |
| 67 | snprintf(buf1, sizeof(buf1), |
| 68 | "[%02d:%02d:%02d.%03d] ", |
| 69 | secs / 3600, |
| 70 | (secs / 60) % 60, |
| 71 | secs % 60, |
| 72 | (int)(ti % 1000)); |
| 73 | /* XXX this blocks entire thread. Rewrite to use |
| 74 | * qemu_chr_fe_write and background I/O callbacks */ |
| 75 | qemu_chr_fe_write_all(&d->chr, |
| 76 | (uint8_t *)buf1, strlen(buf1)); |
| 77 | d->linestart = false; |
| 78 | } |
| 79 | ret += qemu_chr_fe_write(&d->chr, buf + i, 1); |
| 80 | if (buf[i] == '\n') { |
| 81 | d->linestart = true; |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | return ret; |
| 86 | } |
| 87 | |
| 88 | static const char * const mux_help[] = { |
| 89 | "% h print this help\n\r", |
| 90 | "% x exit emulator\n\r", |
| 91 | "% s save disk data back to file (if -snapshot)\n\r", |
| 92 | "% t toggle console timestamps\n\r", |
| 93 | "% b send break (magic sysrq)\n\r", |
| 94 | "% c switch between console and monitor\n\r", |
| 95 | "% % sends %\n\r", |
| 96 | NULL |
| 97 | }; |
| 98 | |
| 99 | int term_escape_char = 0x01; /* ctrl-a is used for escape */ |
| 100 | static void mux_print_help(Chardev *chr) |
| 101 | { |
| 102 | int i, j; |
| 103 | char ebuf[15] = "Escape-Char"; |
| 104 | char cbuf[50] = "\n\r"; |
| 105 | |
| 106 | if (term_escape_char > 0 && term_escape_char < 26) { |
| 107 | snprintf(cbuf, sizeof(cbuf), "\n\r"); |
| 108 | snprintf(ebuf, sizeof(ebuf), "C-%c", term_escape_char - 1 + 'a'); |
| 109 | } else { |
| 110 | snprintf(cbuf, sizeof(cbuf), |
| 111 | "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r", |
| 112 | term_escape_char); |
| 113 | } |
| 114 | /* XXX this blocks entire thread. Rewrite to use |
| 115 | * qemu_chr_fe_write and background I/O callbacks */ |
| 116 | qemu_chr_write_all(chr, (uint8_t *)cbuf, strlen(cbuf)); |
| 117 | for (i = 0; mux_help[i] != NULL; i++) { |
| 118 | for (j = 0; mux_help[i][j] != '\0'; j++) { |
| 119 | if (mux_help[i][j] == '%') { |
| 120 | qemu_chr_write_all(chr, (uint8_t *)ebuf, strlen(ebuf)); |
| 121 | } else { |
| 122 | qemu_chr_write_all(chr, (uint8_t *)&mux_help[i][j], 1); |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | static void mux_chr_send_event(MuxChardev *d, unsigned int mux_nr, |
| 129 | QEMUChrEvent event) |
| 130 | { |
| 131 | CharFrontend *fe = d->frontends[mux_nr]; |
| 132 | |
| 133 | if (fe && fe->chr_event) { |
| 134 | fe->chr_event(fe->opaque, event); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | static void mux_chr_be_event(Chardev *chr, QEMUChrEvent event) |
| 139 | { |
| 140 | MuxChardev *d = MUX_CHARDEV(chr); |
| 141 | |
| 142 | if (d->focus != -1) { |
| 143 | mux_chr_send_event(d, d->focus, event); |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | static int mux_proc_byte(Chardev *chr, MuxChardev *d, int ch) |
| 148 | { |
| 149 | if (d->term_got_escape) { |
| 150 | d->term_got_escape = false; |
| 151 | if (ch == term_escape_char) { |
| 152 | goto send_char; |
| 153 | } |
| 154 | switch (ch) { |
| 155 | case '?': |
| 156 | case 'h': |
| 157 | mux_print_help(chr); |
| 158 | break; |
| 159 | case 'x': |
| 160 | { |
| 161 | const char *term = "QEMU: Terminated\n\r"; |
| 162 | qemu_chr_write_all(chr, (uint8_t *)term, strlen(term)); |
| 163 | qmp_quit(NULL); |
| 164 | break; |
| 165 | } |
| 166 | case 's': |
| 167 | blk_commit_all(); |
| 168 | break; |
| 169 | case 'b': |
| 170 | qemu_chr_be_event(chr, CHR_EVENT_BREAK); |
| 171 | break; |
| 172 | case 'c': { |
| 173 | unsigned int bit; |
| 174 | |
| 175 | /* Handler registered with first fe */ |
| 176 | assert(d->mux_bitset != 0); |
| 177 | /* Switch to the next registered device */ |
| 178 | bit = find_next_bit(&d->mux_bitset, MAX_MUX, d->focus + 1); |
| 179 | if (bit >= MAX_MUX) { |
| 180 | bit = find_next_bit(&d->mux_bitset, MAX_MUX, 0); |
| 181 | } |
| 182 | mux_set_focus(chr, bit); |
| 183 | break; |
| 184 | } case 't': |
| 185 | d->timestamps = !d->timestamps; |
| 186 | d->timestamps_start = -1; |
| 187 | d->linestart = false; |
| 188 | break; |
| 189 | } |
| 190 | } else if (ch == term_escape_char) { |
| 191 | d->term_got_escape = true; |
| 192 | } else { |
| 193 | send_char: |
| 194 | return 1; |
| 195 | } |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | static void mux_chr_accept_input(Chardev *chr) |
| 200 | { |
| 201 | MuxChardev *d = MUX_CHARDEV(chr); |
| 202 | int m = d->focus; |
| 203 | CharFrontend *fe = d->frontends[m]; |
| 204 | |
| 205 | while (fe && d->prod[m] != d->cons[m] && |
| 206 | fe->chr_can_read && fe->chr_can_read(fe->opaque)) { |
| 207 | fe->chr_read(fe->opaque, |
| 208 | &d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1); |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | static int mux_chr_can_read(void *opaque) |
| 213 | { |
| 214 | MuxChardev *d = MUX_CHARDEV(opaque); |
| 215 | int m = d->focus; |
| 216 | CharFrontend *fe = d->frontends[m]; |
| 217 | |
| 218 | if ((d->prod[m] - d->cons[m]) < MUX_BUFFER_SIZE) { |
| 219 | return 1; |
| 220 | } |
| 221 | |
| 222 | if (fe && fe->chr_can_read) { |
| 223 | return fe->chr_can_read(fe->opaque); |
| 224 | } |
| 225 | |
| 226 | return 0; |
| 227 | } |
| 228 | |
| 229 | static void mux_chr_read(void *opaque, const uint8_t *buf, int size) |
| 230 | { |
| 231 | Chardev *chr = CHARDEV(opaque); |
| 232 | MuxChardev *d = MUX_CHARDEV(opaque); |
| 233 | int m = d->focus; |
| 234 | CharFrontend *fe = d->frontends[m]; |
| 235 | int i; |
| 236 | |
| 237 | mux_chr_accept_input(opaque); |
| 238 | |
| 239 | for (i = 0; i < size; i++) |
| 240 | if (mux_proc_byte(chr, d, buf[i])) { |
| 241 | if (d->prod[m] == d->cons[m] && |
| 242 | fe && fe->chr_can_read && |
| 243 | fe->chr_can_read(fe->opaque)) { |
| 244 | fe->chr_read(fe->opaque, &buf[i], 1); |
| 245 | } else { |
| 246 | d->buffer[m][d->prod[m]++ & MUX_BUFFER_MASK] = buf[i]; |
| 247 | } |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event) |
| 252 | { |
| 253 | MuxChardev *d = MUX_CHARDEV(chr); |
| 254 | int bit; |
| 255 | |
| 256 | if (!muxes_opened) { |
| 257 | return; |
| 258 | } |
| 259 | |
| 260 | /* Send the event to all registered listeners */ |
| 261 | bit = -1; |
| 262 | while ((bit = find_next_bit(&d->mux_bitset, MAX_MUX, bit + 1)) < MAX_MUX) { |
| 263 | mux_chr_send_event(d, bit, event); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | static void mux_chr_event(void *opaque, QEMUChrEvent event) |
| 268 | { |
| 269 | mux_chr_send_all_event(CHARDEV(opaque), event); |
| 270 | } |
| 271 | |
| 272 | static GSource *mux_chr_add_watch(Chardev *s, GIOCondition cond) |
| 273 | { |
| 274 | MuxChardev *d = MUX_CHARDEV(s); |
| 275 | Chardev *chr = qemu_chr_fe_get_driver(&d->chr); |
| 276 | ChardevClass *cc = CHARDEV_GET_CLASS(chr); |
| 277 | |
| 278 | if (!cc->chr_add_watch) { |
| 279 | return NULL; |
| 280 | } |
| 281 | |
| 282 | return cc->chr_add_watch(chr, cond); |
| 283 | } |
| 284 | |
| 285 | static void char_mux_finalize(Object *obj) |
| 286 | { |
| 287 | MuxChardev *d = MUX_CHARDEV(obj); |
| 288 | int bit; |
| 289 | |
| 290 | bit = -1; |
| 291 | while ((bit = find_next_bit(&d->mux_bitset, MAX_MUX, bit + 1)) < MAX_MUX) { |
| 292 | CharFrontend *be = d->frontends[bit]; |
| 293 | be->chr = NULL; |
| 294 | d->frontends[bit] = NULL; |
| 295 | } |
| 296 | d->mux_bitset = 0; |
| 297 | qemu_chr_fe_deinit(&d->chr, false); |
| 298 | } |
| 299 | |
| 300 | static void mux_chr_update_read_handlers(Chardev *chr) |
| 301 | { |
| 302 | MuxChardev *d = MUX_CHARDEV(chr); |
| 303 | |
| 304 | /* Fix up the real driver with mux routines */ |
| 305 | qemu_chr_fe_set_handlers_full(&d->chr, |
| 306 | mux_chr_can_read, |
| 307 | mux_chr_read, |
| 308 | mux_chr_event, |
| 309 | NULL, |
| 310 | chr, |
| 311 | chr->gcontext, true, false); |
| 312 | } |
| 313 | |
| 314 | bool mux_chr_attach_frontend(MuxChardev *d, CharFrontend *c, |
| 315 | unsigned int *tag, Error **errp) |
| 316 | { |
| 317 | unsigned int bit; |
| 318 | |
| 319 | QEMU_BUILD_BUG_ON(MAX_MUX > (sizeof(d->mux_bitset) * BITS_PER_BYTE)); |
| 320 | |
| 321 | bit = find_next_zero_bit(&d->mux_bitset, MAX_MUX, 0); |
| 322 | if (bit >= MAX_MUX) { |
| 323 | error_setg(errp, |
| 324 | "too many uses of multiplexed chardev '%s'" |
| 325 | " (maximum is " stringify(MAX_MUX) ")", |
| 326 | d->parent.label); |
| 327 | return false; |
| 328 | } |
| 329 | |
| 330 | d->mux_bitset |= (1ul << bit); |
| 331 | d->frontends[bit] = c; |
| 332 | *tag = bit; |
| 333 | |
| 334 | return true; |
| 335 | } |
| 336 | |
| 337 | bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag) |
| 338 | { |
| 339 | if (!(d->mux_bitset & (1ul << tag))) { |
| 340 | return false; |
| 341 | } |
| 342 | |
| 343 | d->mux_bitset &= ~(1ul << tag); |
| 344 | d->frontends[tag] = NULL; |
| 345 | |
| 346 | return true; |
| 347 | } |
| 348 | |
| 349 | void mux_set_focus(Chardev *chr, unsigned int focus) |
| 350 | { |
| 351 | MuxChardev *d = MUX_CHARDEV(chr); |
| 352 | |
| 353 | assert(d->mux_bitset & (1ul << focus)); |
| 354 | |
| 355 | if (d->focus != -1) { |
| 356 | mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_OUT); |
| 357 | } |
| 358 | |
| 359 | d->focus = focus; |
| 360 | chr->fe = d->frontends[focus]; |
| 361 | mux_chr_send_event(d, d->focus, CHR_EVENT_MUX_IN); |
| 362 | } |
| 363 | |
| 364 | static bool mux_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp) |
| 365 | { |
| 366 | ChardevMux *mux = backend->u.mux.data; |
| 367 | Chardev *drv; |
| 368 | MuxChardev *d = MUX_CHARDEV(chr); |
| 369 | |
| 370 | drv = qemu_chr_find(mux->chardev); |
| 371 | if (drv == NULL) { |
| 372 | error_setg(errp, "mux: base chardev %s not found", mux->chardev); |
| 373 | return false; |
| 374 | } |
| 375 | |
| 376 | d->focus = -1; |
| 377 | if (!qemu_chr_fe_init(&d->chr, drv, errp)) { |
| 378 | return false; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Only move to opened state if we've realized |
| 383 | * the initial set of muxes: |
| 384 | */ |
| 385 | if (muxes_opened) { |
| 386 | qemu_chr_be_event(chr, CHR_EVENT_OPENED); |
| 387 | } |
| 388 | |
| 389 | return true; |
| 390 | } |
| 391 | |
| 392 | static void mux_chr_parse(QemuOpts *opts, ChardevBackend *backend, Error **errp) |
| 393 | { |
| 394 | const char *chardev = qemu_opt_get(opts, "chardev"); |
| 395 | ChardevMux *mux; |
| 396 | |
| 397 | if (chardev == NULL) { |
| 398 | error_setg(errp, "chardev: mux: no chardev given"); |
| 399 | return; |
| 400 | } |
| 401 | backend->type = CHARDEV_BACKEND_KIND_MUX; |
| 402 | mux = backend->u.mux.data = g_new0(ChardevMux, 1); |
| 403 | qemu_chr_parse_common(opts, qapi_ChardevMux_base(mux)); |
| 404 | mux->chardev = g_strdup(chardev); |
| 405 | } |
| 406 | |
| 407 | /** |
| 408 | * Called after processing of default and command-line-specified |
| 409 | * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached |
| 410 | * to a mux chardev. This is done here to ensure that |
| 411 | * output/prompts/banners are only displayed for the FE that has |
| 412 | * focus when initial command-line processing/machine init is |
| 413 | * completed. |
| 414 | * |
| 415 | * After this point, any new FE attached to any new or existing |
| 416 | * mux will receive CHR_EVENT_OPENED notifications for the BE |
| 417 | * immediately. |
| 418 | */ |
| 419 | static void open_muxes(Chardev *chr) |
| 420 | { |
| 421 | /* send OPENED to all already-attached FEs */ |
| 422 | mux_chr_send_all_event(chr, CHR_EVENT_OPENED); |
| 423 | |
| 424 | /* |
| 425 | * mark mux as OPENED so any new FEs will immediately receive |
| 426 | * OPENED event |
| 427 | */ |
| 428 | chr->be_open = 1; |
| 429 | } |
| 430 | |
| 431 | void suspend_mux_open(void) |
| 432 | { |
| 433 | muxes_opened = false; |
| 434 | } |
| 435 | |
| 436 | static int chardev_options_parsed_cb(Object *child, void *opaque) |
| 437 | { |
| 438 | Chardev *chr = (Chardev *)child; |
| 439 | |
| 440 | if (!chr->be_open && CHARDEV_IS_MUX(chr)) { |
| 441 | open_muxes(chr); |
| 442 | } |
| 443 | |
| 444 | return 0; |
| 445 | } |
| 446 | |
| 447 | void resume_mux_open(void) |
| 448 | { |
| 449 | muxes_opened = true; |
| 450 | object_child_foreach(get_chardevs_root(), |
| 451 | chardev_options_parsed_cb, NULL); |
| 452 | } |
| 453 | |
| 454 | static void char_mux_class_init(ObjectClass *oc, const void *data) |
| 455 | { |
| 456 | ChardevClass *cc = CHARDEV_CLASS(oc); |
| 457 | |
| 458 | cc->chr_parse = mux_chr_parse; |
| 459 | cc->chr_open = mux_chr_open; |
| 460 | cc->chr_write = mux_chr_write; |
| 461 | cc->chr_accept_input = mux_chr_accept_input; |
| 462 | cc->chr_add_watch = mux_chr_add_watch; |
| 463 | cc->chr_be_event = mux_chr_be_event; |
| 464 | cc->chr_update_read_handler = mux_chr_update_read_handlers; |
| 465 | } |
| 466 | |
| 467 | static const TypeInfo char_mux_type_info = { |
| 468 | .name = TYPE_CHARDEV_MUX, |
| 469 | .parent = TYPE_CHARDEV, |
| 470 | .class_init = char_mux_class_init, |
| 471 | .instance_size = sizeof(MuxChardev), |
| 472 | .instance_finalize = char_mux_finalize, |
| 473 | }; |
| 474 | |
| 475 | static void register_types(void) |
| 476 | { |
| 477 | type_register_static(&char_mux_type_info); |
| 478 | } |
| 479 | |
| 480 | type_init(register_types); |