tests/test-char.c

   1 #include "qemu/osdep.h"
   2 #include <glib/gstdio.h>
   3
   4 #include "qemu/config-file.h"
   5 #include "qemu/option.h"
   6 #include "qemu/sockets.h"
   7 #include "chardev/char-fe.h"
   8 #include "chardev/char-mux.h"
   9 #include "sysemu/sysemu.h"
  10 #include "qapi/error.h"
  11 #include "qapi/qapi-commands-char.h"
  12 #include "qapi/qmp/qdict.h"
  13 #include "qom/qom-qobject.h"
  14
  15 static bool quit;
  16
  17 typedef struct FeHandler {
  18     int read_count;
  19     int last_event;
  20     char read_buf[128];
  21 } FeHandler;
  22
  23 static void main_loop(void)
  24 {
  25     quit = false;
  26     do {
  27         main_loop_wait(false);
  28     } while (!quit);
  29 }
  30
  31 static int fe_can_read(void *opaque)
  32 {
  33     FeHandler *h = opaque;
  34
  35     return sizeof(h->read_buf) - h->read_count;
  36 }
  37
  38 static void fe_read(void *opaque, const uint8_t *buf, int size)
  39 {
  40     FeHandler *h = opaque;
  41
  42     g_assert_cmpint(size, <=, fe_can_read(opaque));
  43
  44     memcpy(h->read_buf + h->read_count, buf, size);
  45     h->read_count += size;
  46     quit = true;
  47 }
  48
  49 static void fe_event(void *opaque, int event)
  50 {
  51     FeHandler *h = opaque;
  52
  53     h->last_event = event;
  54     if (event != CHR_EVENT_BREAK) {
  55         quit = true;
  56     }
  57 }
  58
  59 #ifdef CONFIG_HAS_GLIB_SUBPROCESS_TESTS
  60 #ifdef _WIN32
  61 static void char_console_test_subprocess(void)
  62 {
  63     QemuOpts *opts;
  64     Chardev *chr;
  65
  66     opts = qemu_opts_create(qemu_find_opts("chardev"), "console-label",
  67                             1, &error_abort);
  68     qemu_opt_set(opts, "backend", "console", &error_abort);
  69
  70     chr = qemu_chr_new_from_opts(opts, NULL);
  71     g_assert_nonnull(chr);
  72
  73     qemu_chr_write_all(chr, (const uint8_t *)"CONSOLE", 7);
  74
  75     qemu_opts_del(opts);
  76     object_unparent(OBJECT(chr));
  77 }
  78
  79 static void char_console_test(void)
  80 {
  81     g_test_trap_subprocess("/char/console/subprocess", 0, 0);
  82     g_test_trap_assert_passed();
  83     g_test_trap_assert_stdout("CONSOLE");
  84 }
  85 #endif
  86 static void char_stdio_test_subprocess(void)
  87 {
  88     Chardev *chr;
  89     CharBackend be;
  90     int ret;
  91
  92     chr = qemu_chr_new("label", "stdio");
  93     g_assert_nonnull(chr);
  94
  95     qemu_chr_fe_init(&be, chr, &error_abort);
  96     qemu_chr_fe_set_open(&be, true);
  97     ret = qemu_chr_fe_write(&be, (void *)"buf", 4);
  98     g_assert_cmpint(ret, ==, 4);
  99
 100     qemu_chr_fe_deinit(&be, true);
 101 }
 102
 103 static void char_stdio_test(void)
 104 {
 105     g_test_trap_subprocess("/char/stdio/subprocess", 0, 0);
 106     g_test_trap_assert_passed();
 107     g_test_trap_assert_stdout("buf");
 108 }
 109 #endif
 110
 111 static void char_ringbuf_test(void)
 112 {
 113     QemuOpts *opts;
 114     Chardev *chr;
 115     CharBackend be;
 116     char *data;
 117     int ret;
 118
 119     opts = qemu_opts_create(qemu_find_opts("chardev"), "ringbuf-label",
 120                             1, &error_abort);
 121     qemu_opt_set(opts, "backend", "ringbuf", &error_abort);
 122
 123     qemu_opt_set(opts, "size", "5", &error_abort);
 124     chr = qemu_chr_new_from_opts(opts, NULL);
 125     g_assert_null(chr);
 126     qemu_opts_del(opts);
 127
 128     opts = qemu_opts_create(qemu_find_opts("chardev"), "ringbuf-label",
 129                             1, &error_abort);
 130     qemu_opt_set(opts, "backend", "ringbuf", &error_abort);
 131     qemu_opt_set(opts, "size", "2", &error_abort);
 132     chr = qemu_chr_new_from_opts(opts, &error_abort);
 133     g_assert_nonnull(chr);
 134     qemu_opts_del(opts);
 135
 136     qemu_chr_fe_init(&be, chr, &error_abort);
 137     ret = qemu_chr_fe_write(&be, (void *)"buff", 4);
 138     g_assert_cmpint(ret, ==, 4);
 139
 140     data = qmp_ringbuf_read("ringbuf-label", 4, false, 0, &error_abort);
 141     g_assert_cmpstr(data, ==, "ff");
 142     g_free(data);
 143
 144     data = qmp_ringbuf_read("ringbuf-label", 4, false, 0, &error_abort);
 145     g_assert_cmpstr(data, ==, "");
 146     g_free(data);
 147
 148     qemu_chr_fe_deinit(&be, true);
 149
 150     /* check alias */
 151     opts = qemu_opts_create(qemu_find_opts("chardev"), "memory-label",
 152                             1, &error_abort);
 153     qemu_opt_set(opts, "backend", "memory", &error_abort);
 154     qemu_opt_set(opts, "size", "2", &error_abort);
 155     chr = qemu_chr_new_from_opts(opts, NULL);
 156     g_assert_nonnull(chr);
 157     object_unparent(OBJECT(chr));
 158     qemu_opts_del(opts);
 159 }
 160
 161 static void char_mux_test(void)
 162 {
 163     QemuOpts *opts;
 164     Chardev *chr, *base;
 165     char *data;
 166     FeHandler h1 = { 0, }, h2 = { 0, };
 167     CharBackend chr_be1, chr_be2;
 168
 169     muxes_realized = true; /* done after machine init */
 170     opts = qemu_opts_create(qemu_find_opts("chardev"), "mux-label",
 171                             1, &error_abort);
 172     qemu_opt_set(opts, "backend", "ringbuf", &error_abort);
 173     qemu_opt_set(opts, "size", "128", &error_abort);
 174     qemu_opt_set(opts, "mux", "on", &error_abort);
 175     chr = qemu_chr_new_from_opts(opts, &error_abort);
 176     g_assert_nonnull(chr);
 177     qemu_opts_del(opts);
 178
 179     qemu_chr_fe_init(&chr_be1, chr, &error_abort);
 180     qemu_chr_fe_set_handlers(&chr_be1,
 181                              fe_can_read,
 182                              fe_read,
 183                              fe_event,
 184                              NULL,
 185                              &h1,
 186                              NULL, true);
 187
 188     qemu_chr_fe_init(&chr_be2, chr, &error_abort);
 189     qemu_chr_fe_set_handlers(&chr_be2,
 190                              fe_can_read,
 191                              fe_read,
 192                              fe_event,
 193                              NULL,
 194                              &h2,
 195                              NULL, true);
 196     qemu_chr_fe_take_focus(&chr_be2);
 197
 198     base = qemu_chr_find("mux-label-base");
 199     g_assert_cmpint(qemu_chr_be_can_write(base), !=, 0);
 200
 201     qemu_chr_be_write(base, (void *)"hello", 6);
 202     g_assert_cmpint(h1.read_count, ==, 0);
 203     g_assert_cmpint(h2.read_count, ==, 6);
 204     g_assert_cmpstr(h2.read_buf, ==, "hello");
 205     h2.read_count = 0;
 206
 207     g_assert_cmpint(h1.last_event, !=, 42); /* should be MUX_OUT or OPENED */
 208     g_assert_cmpint(h2.last_event, !=, 42); /* should be MUX_IN or OPENED */
 209     /* sending event on the base broadcast to all fe, historical reasons? */
 210     qemu_chr_be_event(base, 42);
 211     g_assert_cmpint(h1.last_event, ==, 42);
 212     g_assert_cmpint(h2.last_event, ==, 42);
 213     qemu_chr_be_event(chr, -1);
 214     g_assert_cmpint(h1.last_event, ==, 42);
 215     g_assert_cmpint(h2.last_event, ==, -1);
 216
 217     /* switch focus */
 218     qemu_chr_be_write(base, (void *)"\1c", 2);
 219     g_assert_cmpint(h1.last_event, ==, CHR_EVENT_MUX_IN);
 220     g_assert_cmpint(h2.last_event, ==, CHR_EVENT_MUX_OUT);
 221     qemu_chr_be_event(chr, -1);
 222     g_assert_cmpint(h1.last_event, ==, -1);
 223     g_assert_cmpint(h2.last_event, ==, CHR_EVENT_MUX_OUT);
 224
 225     qemu_chr_be_write(base, (void *)"hello", 6);
 226     g_assert_cmpint(h2.read_count, ==, 0);
 227     g_assert_cmpint(h1.read_count, ==, 6);
 228     g_assert_cmpstr(h1.read_buf, ==, "hello");
 229     h1.read_count = 0;
 230
 231     /* remove first handler */
 232     qemu_chr_fe_set_handlers(&chr_be1, NULL, NULL, NULL, NULL,
 233                              NULL, NULL, true);
 234     qemu_chr_be_write(base, (void *)"hello", 6);
 235     g_assert_cmpint(h1.read_count, ==, 0);
 236     g_assert_cmpint(h2.read_count, ==, 0);
 237
 238     qemu_chr_be_write(base, (void *)"\1c", 2);
 239     qemu_chr_be_write(base, (void *)"hello", 6);
 240     g_assert_cmpint(h1.read_count, ==, 0);
 241     g_assert_cmpint(h2.read_count, ==, 6);
 242     g_assert_cmpstr(h2.read_buf, ==, "hello");
 243     h2.read_count = 0;
 244
 245     /* print help */
 246     qemu_chr_be_write(base, (void *)"\1?", 2);
 247     data = qmp_ringbuf_read("mux-label-base", 128, false, 0, &error_abort);
 248     g_assert_cmpint(strlen(data), !=, 0);
 249     g_free(data);
 250
 251     qemu_chr_fe_deinit(&chr_be1, false);
 252     qemu_chr_fe_deinit(&chr_be2, true);
 253 }
 254
 255 typedef struct SocketIdleData {
 256     GMainLoop *loop;
 257     Chardev *chr;
 258     bool conn_expected;
 259     CharBackend *be;
 260     CharBackend *client_be;
 261 } SocketIdleData;
 262
 263 static gboolean char_socket_test_idle(gpointer user_data)
 264 {
 265     SocketIdleData *data = user_data;
 266
 267     if (object_property_get_bool(OBJECT(data->chr), "connected", NULL)
 268         == data->conn_expected) {
 269         quit = true;
 270         return FALSE;
 271     }
 272
 273     return TRUE;
 274 }
 275
 276 static void socket_read(void *opaque, const uint8_t *buf, int size)
 277 {
 278     SocketIdleData *data = opaque;
 279
 280     g_assert_cmpint(size, ==, 1);
 281     g_assert_cmpint(*buf, ==, 'Z');
 282
 283     size = qemu_chr_fe_write(data->be, (const uint8_t *)"hello", 5);
 284     g_assert_cmpint(size, ==, 5);
 285 }
 286
 287 static int socket_can_read(void *opaque)
 288 {
 289     return 10;
 290 }
 291
 292 static void socket_read_hello(void *opaque, const uint8_t *buf, int size)
 293 {
 294     g_assert_cmpint(size, ==, 5);
 295     g_assert(strncmp((char *)buf, "hello", 5) == 0);
 296
 297     quit = true;
 298 }
 299
 300 static int socket_can_read_hello(void *opaque)
 301 {
 302     return 10;
 303 }
 304
 305 static void char_socket_test(void)
 306 {
 307     Chardev *chr = qemu_chr_new("server", "tcp:127.0.0.1:0,server,nowait");
 308     Chardev *chr_client;
 309     QObject *addr;
 310     QDict *qdict;
 311     const char *port;
 312     SocketIdleData d = { .chr = chr };
 313     CharBackend be;
 314     CharBackend client_be;
 315     char *tmp;
 316
 317     d.be = &be;
 318     d.client_be = &be;
 319
 320     g_assert_nonnull(chr);
 321     g_assert(!object_property_get_bool(OBJECT(chr), "connected", &error_abort));
 322
 323     addr = object_property_get_qobject(OBJECT(chr), "addr", &error_abort);
 324     qdict = qobject_to_qdict(addr);
 325     port = qdict_get_str(qdict, "port");
 326     tmp = g_strdup_printf("tcp:127.0.0.1:%s", port);
 327     QDECREF(qdict);
 328
 329     qemu_chr_fe_init(&be, chr, &error_abort);
 330     qemu_chr_fe_set_handlers(&be, socket_can_read, socket_read,
 331                              NULL, NULL, &d, NULL, true);
 332
 333     chr_client = qemu_chr_new("client", tmp);
 334     qemu_chr_fe_init(&client_be, chr_client, &error_abort);
 335     qemu_chr_fe_set_handlers(&client_be, socket_can_read_hello,
 336                              socket_read_hello,
 337                              NULL, NULL, &d, NULL, true);
 338     g_free(tmp);
 339
 340     d.conn_expected = true;
 341     guint id = g_idle_add(char_socket_test_idle, &d);
 342     g_source_set_name_by_id(id, "test-idle");
 343     g_assert_cmpint(id, >, 0);
 344     main_loop();
 345
 346     g_assert(object_property_get_bool(OBJECT(chr), "connected", &error_abort));
 347     g_assert(object_property_get_bool(OBJECT(chr_client),
 348                                       "connected", &error_abort));
 349
 350     qemu_chr_write_all(chr_client, (const uint8_t *)"Z", 1);
 351     main_loop();
 352
 353     object_unparent(OBJECT(chr_client));
 354
 355     d.conn_expected = false;
 356     g_idle_add(char_socket_test_idle, &d);
 357     main_loop();
 358
 359     object_unparent(OBJECT(chr));
 360 }
 361
 362 #ifndef _WIN32
 363 static void char_pipe_test(void)
 364 {
 365     gchar *tmp_path = g_dir_make_tmp("qemu-test-char.XXXXXX", NULL);
 366     gchar *tmp, *in, *out, *pipe = g_build_filename(tmp_path, "pipe", NULL);
 367     Chardev *chr;
 368     CharBackend be;
 369     int ret, fd;
 370     char buf[10];
 371     FeHandler fe = { 0, };
 372
 373     in = g_strdup_printf("%s.in", pipe);
 374     if (mkfifo(in, 0600) < 0) {
 375         abort();
 376     }
 377     out = g_strdup_printf("%s.out", pipe);
 378     if (mkfifo(out, 0600) < 0) {
 379         abort();
 380     }
 381
 382     tmp = g_strdup_printf("pipe:%s", pipe);
 383     chr = qemu_chr_new("pipe", tmp);
 384     g_assert_nonnull(chr);
 385     g_free(tmp);
 386
 387     qemu_chr_fe_init(&be, chr, &error_abort);
 388
 389     ret = qemu_chr_fe_write(&be, (void *)"pipe-out", 9);
 390     g_assert_cmpint(ret, ==, 9);
 391
 392     fd = open(out, O_RDWR);
 393     ret = read(fd, buf, sizeof(buf));
 394     g_assert_cmpint(ret, ==, 9);
 395     g_assert_cmpstr(buf, ==, "pipe-out");
 396     close(fd);
 397
 398     fd = open(in, O_WRONLY);
 399     ret = write(fd, "pipe-in", 8);
 400     g_assert_cmpint(ret, ==, 8);
 401     close(fd);
 402
 403     qemu_chr_fe_set_handlers(&be,
 404                              fe_can_read,
 405                              fe_read,
 406                              fe_event,
 407                              NULL,
 408                              &fe,
 409                              NULL, true);
 410
 411     main_loop();
 412
 413     g_assert_cmpint(fe.read_count, ==, 8);
 414     g_assert_cmpstr(fe.read_buf, ==, "pipe-in");
 415
 416     qemu_chr_fe_deinit(&be, true);
 417
 418     g_assert(g_unlink(in) == 0);
 419     g_assert(g_unlink(out) == 0);
 420     g_assert(g_rmdir(tmp_path) == 0);
 421     g_free(in);
 422     g_free(out);
 423     g_free(tmp_path);
 424     g_free(pipe);
 425 }
 426 #endif
 427
 428 static int make_udp_socket(int *port)
 429 {
 430     struct sockaddr_in addr = { 0, };
 431     socklen_t alen = sizeof(addr);
 432     int ret, sock = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 433
 434     g_assert_cmpint(sock, >, 0);
 435     addr.sin_family = AF_INET ;
 436     addr.sin_addr.s_addr = htonl(INADDR_ANY);
 437     addr.sin_port = 0;
 438     ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));
 439     g_assert_cmpint(ret, ==, 0);
 440     ret = getsockname(sock, (struct sockaddr *)&addr, &alen);
 441     g_assert_cmpint(ret, ==, 0);
 442
 443     *port = ntohs(addr.sin_port);
 444     return sock;
 445 }
 446
 447 static void char_udp_test_internal(Chardev *reuse_chr, int sock)
 448 {
 449     struct sockaddr_in other;
 450     SocketIdleData d = { 0, };
 451     Chardev *chr;
 452     CharBackend *be;
 453     socklen_t alen = sizeof(other);
 454     int ret;
 455     char buf[10];
 456     char *tmp = NULL;
 457
 458     if (reuse_chr) {
 459         chr = reuse_chr;
 460         be = chr->be;
 461     } else {
 462         int port;
 463         sock = make_udp_socket(&port);
 464         tmp = g_strdup_printf("udp:127.0.0.1:%d", port);
 465         chr = qemu_chr_new("client", tmp);
 466         g_assert_nonnull(chr);
 467
 468         be = g_alloca(sizeof(CharBackend));
 469         qemu_chr_fe_init(be, chr, &error_abort);
 470     }
 471
 472     d.chr = chr;
 473     qemu_chr_fe_set_handlers(be, socket_can_read_hello, socket_read_hello,
 474                              NULL, NULL, &d, NULL, true);
 475     ret = qemu_chr_write_all(chr, (uint8_t *)"hello", 5);
 476     g_assert_cmpint(ret, ==, 5);
 477
 478     ret = recvfrom(sock, buf, sizeof(buf), 0,
 479                    (struct sockaddr *)&other, &alen);
 480     g_assert_cmpint(ret, ==, 5);
 481     ret = sendto(sock, buf, 5, 0, (struct sockaddr *)&other, alen);
 482     g_assert_cmpint(ret, ==, 5);
 483
 484     main_loop();
 485
 486     if (!reuse_chr) {
 487         close(sock);
 488         qemu_chr_fe_deinit(be, true);
 489     }
 490     g_free(tmp);
 491 }
 492
 493 static void char_udp_test(void)
 494 {
 495     char_udp_test_internal(NULL, 0);
 496 }
 497
 498 #ifdef HAVE_CHARDEV_SERIAL
 499 static void char_serial_test(void)
 500 {
 501     QemuOpts *opts;
 502     Chardev *chr;
 503
 504     opts = qemu_opts_create(qemu_find_opts("chardev"), "serial-id",
 505                             1, &error_abort);
 506     qemu_opt_set(opts, "backend", "serial", &error_abort);
 507     qemu_opt_set(opts, "path", "/dev/null", &error_abort);
 508
 509     chr = qemu_chr_new_from_opts(opts, NULL);
 510     g_assert_nonnull(chr);
 511     /* TODO: add more tests with a pty */
 512     object_unparent(OBJECT(chr));
 513
 514     /* test tty alias */
 515     qemu_opt_set(opts, "backend", "tty", &error_abort);
 516     chr = qemu_chr_new_from_opts(opts, NULL);
 517     g_assert_nonnull(chr);
 518     object_unparent(OBJECT(chr));
 519
 520     qemu_opts_del(opts);
 521 }
 522 #endif
 523
 524 #ifndef _WIN32
 525 static void char_file_fifo_test(void)
 526 {
 527     Chardev *chr;
 528     CharBackend be;
 529     char *tmp_path = g_dir_make_tmp("qemu-test-char.XXXXXX", NULL);
 530     char *fifo = g_build_filename(tmp_path, "fifo", NULL);
 531     char *out = g_build_filename(tmp_path, "out", NULL);
 532     ChardevFile file = { .in = fifo,
 533                          .has_in = true,
 534                          .out = out };
 535     ChardevBackend backend = { .type = CHARDEV_BACKEND_KIND_FILE,
 536                                .u.file.data = &file };
 537     FeHandler fe = { 0, };
 538     int fd, ret;
 539
 540     if (mkfifo(fifo, 0600) < 0) {
 541         abort();
 542     }
 543
 544     fd = open(fifo, O_RDWR);
 545     ret = write(fd, "fifo-in", 8);
 546     g_assert_cmpint(ret, ==, 8);
 547
 548     chr = qemu_chardev_new("label-file", TYPE_CHARDEV_FILE, &backend,
 549                            &error_abort);
 550
 551     qemu_chr_fe_init(&be, chr, &error_abort);
 552     qemu_chr_fe_set_handlers(&be,
 553                              fe_can_read,
 554                              fe_read,
 555                              fe_event,
 556                              NULL,
 557                              &fe, NULL, true);
 558
 559     g_assert_cmpint(fe.last_event, !=, CHR_EVENT_BREAK);
 560     qmp_chardev_send_break("label-foo", NULL);
 561     g_assert_cmpint(fe.last_event, !=, CHR_EVENT_BREAK);
 562     qmp_chardev_send_break("label-file", NULL);
 563     g_assert_cmpint(fe.last_event, ==, CHR_EVENT_BREAK);
 564
 565     main_loop();
 566
 567     close(fd);
 568
 569     g_assert_cmpint(fe.read_count, ==, 8);
 570     g_assert_cmpstr(fe.read_buf, ==, "fifo-in");
 571
 572     qemu_chr_fe_deinit(&be, true);
 573
 574     g_unlink(fifo);
 575     g_free(fifo);
 576     g_unlink(out);
 577     g_free(out);
 578     g_rmdir(tmp_path);
 579     g_free(tmp_path);
 580 }
 581 #endif
 582
 583 static void char_file_test_internal(Chardev *ext_chr, const char *filepath)
 584 {
 585     char *tmp_path = g_dir_make_tmp("qemu-test-char.XXXXXX", NULL);
 586     char *out;
 587     Chardev *chr;
 588     char *contents = NULL;
 589     ChardevFile file = {};
 590     ChardevBackend backend = { .type = CHARDEV_BACKEND_KIND_FILE,
 591                                .u.file.data = &file };
 592     gsize length;
 593     int ret;
 594
 595     if (ext_chr) {
 596         chr = ext_chr;
 597         out = g_strdup(filepath);
 598         file.out = out;
 599     } else {
 600         out = g_build_filename(tmp_path, "out", NULL);
 601         file.out = out;
 602         chr = qemu_chardev_new(NULL, TYPE_CHARDEV_FILE, &backend,
 603                                &error_abort);
 604     }
 605     ret = qemu_chr_write_all(chr, (uint8_t *)"hello!", 6);
 606     g_assert_cmpint(ret, ==, 6);
 607
 608     ret = g_file_get_contents(out, &contents, &length, NULL);
 609     g_assert(ret == TRUE);
 610     g_assert_cmpint(length, ==, 6);
 611     g_assert(strncmp(contents, "hello!", 6) == 0);
 612
 613     if (!ext_chr) {
 614         object_unref(OBJECT(chr));
 615         g_unlink(out);
 616     }
 617     g_free(contents);
 618     g_rmdir(tmp_path);
 619     g_free(tmp_path);
 620     g_free(out);
 621 }
 622
 623 static void char_file_test(void)
 624 {
 625     char_file_test_internal(NULL, NULL);
 626 }
 627
 628 static void char_null_test(void)
 629 {
 630     Error *err = NULL;
 631     Chardev *chr;
 632     CharBackend be;
 633     int ret;
 634
 635     chr = qemu_chr_find("label-null");
 636     g_assert_null(chr);
 637
 638     chr = qemu_chr_new("label-null", "null");
 639     chr = qemu_chr_find("label-null");
 640     g_assert_nonnull(chr);
 641
 642     g_assert(qemu_chr_has_feature(chr,
 643                  QEMU_CHAR_FEATURE_FD_PASS) == false);
 644     g_assert(qemu_chr_has_feature(chr,
 645                  QEMU_CHAR_FEATURE_RECONNECTABLE) == false);
 646
 647     /* check max avail */
 648     qemu_chr_fe_init(&be, chr, &error_abort);
 649     qemu_chr_fe_init(&be, chr, &err);
 650     error_free_or_abort(&err);
 651
 652     /* deinit & reinit */
 653     qemu_chr_fe_deinit(&be, false);
 654     qemu_chr_fe_init(&be, chr, &error_abort);
 655
 656     qemu_chr_fe_set_open(&be, true);
 657
 658     qemu_chr_fe_set_handlers(&be,
 659                              fe_can_read,
 660                              fe_read,
 661                              fe_event,
 662                              NULL,
 663                              NULL, NULL, true);
 664
 665     ret = qemu_chr_fe_write(&be, (void *)"buf", 4);
 666     g_assert_cmpint(ret, ==, 4);
 667
 668     qemu_chr_fe_deinit(&be, true);
 669 }
 670
 671 static void char_invalid_test(void)
 672 {
 673     Chardev *chr;
 674
 675     chr = qemu_chr_new("label-invalid", "invalid");
 676     g_assert_null(chr);
 677 }
 678
 679 static int chardev_change(void *opaque)
 680 {
 681     return 0;
 682 }
 683
 684 static int chardev_change_denied(void *opaque)
 685 {
 686     return -1;
 687 }
 688
 689 static void char_hotswap_test(void)
 690 {
 691     char *chr_args;
 692     Chardev *chr;
 693     CharBackend be;
 694
 695     gchar *tmp_path = g_dir_make_tmp("qemu-test-char.XXXXXX", NULL);
 696     char *filename = g_build_filename(tmp_path, "file", NULL);
 697     ChardevFile file = { .out = filename };
 698     ChardevBackend backend = { .type = CHARDEV_BACKEND_KIND_FILE,
 699                                .u.file.data = &file };
 700     ChardevReturn *ret;
 701
 702     int port;
 703     int sock = make_udp_socket(&port);
 704     g_assert_cmpint(sock, >, 0);
 705
 706     chr_args = g_strdup_printf("udp:127.0.0.1:%d", port);
 707
 708     chr = qemu_chr_new("chardev", chr_args);
 709     qemu_chr_fe_init(&be, chr, &error_abort);
 710
 711     /* check that chardev operates correctly */
 712     char_udp_test_internal(chr, sock);
 713
 714     /* set the handler that denies the hotswap */
 715     qemu_chr_fe_set_handlers(&be, NULL, NULL,
 716                              NULL, chardev_change_denied, NULL, NULL, true);
 717
 718     /* now, change is denied and has to keep the old backend operating */
 719     ret = qmp_chardev_change("chardev", &backend, NULL);
 720     g_assert(!ret);
 721     g_assert(be.chr == chr);
 722
 723     char_udp_test_internal(chr, sock);
 724
 725     /* now allow the change */
 726     qemu_chr_fe_set_handlers(&be, NULL, NULL,
 727                              NULL, chardev_change, NULL, NULL, true);
 728
 729     /* has to succeed now */
 730     ret = qmp_chardev_change("chardev", &backend, &error_abort);
 731     g_assert(be.chr != chr);
 732
 733     close(sock);
 734     chr = be.chr;
 735
 736     /* run the file chardev test */
 737     char_file_test_internal(chr, filename);
 738
 739     object_unparent(OBJECT(chr));
 740
 741     qapi_free_ChardevReturn(ret);
 742     g_unlink(filename);
 743     g_free(filename);
 744     g_rmdir(tmp_path);
 745     g_free(tmp_path);
 746     g_free(chr_args);
 747 }
 748
 749 int main(int argc, char **argv)
 750 {
 751     qemu_init_main_loop(&error_abort);
 752     socket_init();
 753
 754     g_test_init(&argc, &argv, NULL);
 755
 756     module_call_init(MODULE_INIT_QOM);
 757     qemu_add_opts(&qemu_chardev_opts);
 758
 759     g_test_add_func("/char/null", char_null_test);
 760     g_test_add_func("/char/invalid", char_invalid_test);
 761     g_test_add_func("/char/ringbuf", char_ringbuf_test);
 762     g_test_add_func("/char/mux", char_mux_test);
 763 #ifdef CONFIG_HAS_GLIB_SUBPROCESS_TESTS
 764 #ifdef _WIN32
 765     g_test_add_func("/char/console/subprocess", char_console_test_subprocess);
 766     g_test_add_func("/char/console", char_console_test);
 767 #endif
 768     g_test_add_func("/char/stdio/subprocess", char_stdio_test_subprocess);
 769     g_test_add_func("/char/stdio", char_stdio_test);
 770 #endif
 771 #ifndef _WIN32
 772     g_test_add_func("/char/pipe", char_pipe_test);
 773 #endif
 774     g_test_add_func("/char/file", char_file_test);
 775 #ifndef _WIN32
 776     g_test_add_func("/char/file-fifo", char_file_fifo_test);
 777 #endif
 778     g_test_add_func("/char/socket", char_socket_test);
 779     g_test_add_func("/char/udp", char_udp_test);
 780 #ifdef HAVE_CHARDEV_SERIAL
 781     g_test_add_func("/char/serial", char_serial_test);
 782 #endif
 783     g_test_add_func("/char/hotswap", char_hotswap_test);
 784
 785     return g_test_run();
 786 }