| 1 | /* |
| 2 | * QEMU network listener |
| 3 | * |
| 4 | * Copyright (c) 2016-2017 Red Hat, Inc. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License along |
| 17 | * with this program; if not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include "qemu/osdep.h" |
| 22 | #include "io/net-listener.h" |
| 23 | #include "io/dns-resolver.h" |
| 24 | #include "qapi/error.h" |
| 25 | #include "qemu/module.h" |
| 26 | #include "qemu/lockable.h" |
| 27 | #include "qemu/main-loop.h" |
| 28 | #include "trace.h" |
| 29 | |
| 30 | struct QIONetListenerSource { |
| 31 | QIOChannelSocket *sioc; |
| 32 | GSource *io_source; |
| 33 | QIONetListener *listener; |
| 34 | }; |
| 35 | |
| 36 | QIONetListener *qio_net_listener_new(void) |
| 37 | { |
| 38 | QIONetListener *listener; |
| 39 | |
| 40 | listener = QIO_NET_LISTENER(object_new(TYPE_QIO_NET_LISTENER)); |
| 41 | return listener; |
| 42 | } |
| 43 | |
| 44 | void qio_net_listener_set_name(QIONetListener *listener, |
| 45 | const char *name) |
| 46 | { |
| 47 | g_free(listener->name); |
| 48 | listener->name = g_strdup(name); |
| 49 | } |
| 50 | |
| 51 | |
| 52 | static gboolean qio_net_listener_channel_func(QIOChannel *ioc, |
| 53 | GIOCondition condition, |
| 54 | gpointer opaque) |
| 55 | { |
| 56 | QIONetListener *listener = QIO_NET_LISTENER(opaque); |
| 57 | QIOChannelSocket *sioc; |
| 58 | QIONetListenerClientFunc io_func; |
| 59 | gpointer io_data; |
| 60 | GMainContext *context; |
| 61 | AioContext *aio_context; |
| 62 | |
| 63 | sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), |
| 64 | NULL); |
| 65 | if (!sioc) { |
| 66 | return TRUE; |
| 67 | } |
| 68 | |
| 69 | WITH_QEMU_LOCK_GUARD(&listener->lock) { |
| 70 | io_func = listener->io_func; |
| 71 | io_data = listener->io_data; |
| 72 | context = listener->context; |
| 73 | aio_context = listener->aio_context; |
| 74 | } |
| 75 | |
| 76 | trace_qio_net_listener_callback(listener, io_func, context, aio_context); |
| 77 | if (io_func) { |
| 78 | io_func(listener, sioc, io_data); |
| 79 | } |
| 80 | |
| 81 | object_unref(OBJECT(sioc)); |
| 82 | |
| 83 | return TRUE; |
| 84 | } |
| 85 | |
| 86 | |
| 87 | static void qio_net_listener_aio_func(void *opaque) |
| 88 | { |
| 89 | QIONetListenerSource *data = opaque; |
| 90 | |
| 91 | assert(data->io_source == NULL); |
| 92 | assert(data->listener->aio_context != NULL); |
| 93 | qio_net_listener_channel_func(QIO_CHANNEL(data->sioc), G_IO_IN, |
| 94 | data->listener); |
| 95 | } |
| 96 | |
| 97 | |
| 98 | int qio_net_listener_open_sync(QIONetListener *listener, |
| 99 | SocketAddress *addr, |
| 100 | int num, |
| 101 | Error **errp) |
| 102 | { |
| 103 | QIODNSResolver *resolver = qio_dns_resolver_get_instance(); |
| 104 | SocketAddress **resaddrs; |
| 105 | size_t nresaddrs; |
| 106 | size_t i; |
| 107 | Error *err = NULL; |
| 108 | bool success = false; |
| 109 | |
| 110 | if (qio_dns_resolver_lookup_sync(resolver, |
| 111 | addr, |
| 112 | &nresaddrs, |
| 113 | &resaddrs, |
| 114 | errp) < 0) { |
| 115 | return -1; |
| 116 | } |
| 117 | |
| 118 | for (i = 0; i < nresaddrs; i++) { |
| 119 | QIOChannelSocket *sioc = qio_channel_socket_new(); |
| 120 | |
| 121 | if (qio_channel_socket_listen_sync(sioc, resaddrs[i], num, |
| 122 | err ? NULL : &err) == 0) { |
| 123 | success = true; |
| 124 | |
| 125 | qio_net_listener_add(listener, sioc); |
| 126 | } |
| 127 | |
| 128 | qapi_free_SocketAddress(resaddrs[i]); |
| 129 | object_unref(OBJECT(sioc)); |
| 130 | } |
| 131 | g_free(resaddrs); |
| 132 | |
| 133 | if (success) { |
| 134 | error_free(err); |
| 135 | return 0; |
| 136 | } else { |
| 137 | error_propagate(errp, err); |
| 138 | return -1; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * i == 0 to set watch on entire array, non-zero to only set watch on |
| 144 | * recent additions when earlier entries are already watched. |
| 145 | * |
| 146 | * listener->lock must be held by caller. |
| 147 | */ |
| 148 | static void |
| 149 | qio_net_listener_watch(QIONetListener *listener, size_t i, const char *caller) |
| 150 | { |
| 151 | if (!listener->io_func) { |
| 152 | return; |
| 153 | } |
| 154 | |
| 155 | trace_qio_net_listener_watch(listener, listener->io_func, |
| 156 | listener->context, listener->aio_context, |
| 157 | caller); |
| 158 | for ( ; i < listener->nsioc; i++) { |
| 159 | if (!listener->aio_context) { |
| 160 | /* |
| 161 | * The user passed a GMainContext with the async callback; |
| 162 | * they plan on running the default or their own g_main_loop. |
| 163 | */ |
| 164 | object_ref(OBJECT(listener)); |
| 165 | listener->source[i]->io_source = qio_channel_add_watch_source( |
| 166 | QIO_CHANNEL(listener->source[i]->sioc), G_IO_IN, |
| 167 | qio_net_listener_channel_func, |
| 168 | listener, (GDestroyNotify)object_unref, listener->context); |
| 169 | } else { |
| 170 | /* |
| 171 | * The user passed an AioContext. At this point, |
| 172 | * AioContext lacks a clean way to call a notify function |
| 173 | * to release a final reference after any callback is |
| 174 | * complete. But we asserted earlier that the async |
| 175 | * callback is changed only from the thread associated |
| 176 | * with aio_context, which means no other thread is in the |
| 177 | * middle of running the callback when we are changing the |
| 178 | * refcount on listener here. Therefore, a single |
| 179 | * reference here is sufficient to ensure listener is not |
| 180 | * finalized during the callback. |
| 181 | */ |
| 182 | assert(listener->context == NULL); |
| 183 | if (i == 0) { |
| 184 | object_ref(OBJECT(listener)); |
| 185 | } |
| 186 | qio_channel_set_aio_fd_handler( |
| 187 | QIO_CHANNEL(listener->source[i]->sioc), |
| 188 | listener->aio_context, qio_net_listener_aio_func, |
| 189 | NULL, NULL, listener->source[i]); |
| 190 | } |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | /* listener->lock must be held by caller. */ |
| 195 | static void |
| 196 | qio_net_listener_unwatch(QIONetListener *listener, const char *caller) |
| 197 | { |
| 198 | size_t i; |
| 199 | |
| 200 | if (!listener->io_func) { |
| 201 | return; |
| 202 | } |
| 203 | |
| 204 | trace_qio_net_listener_unwatch(listener, listener->io_func, |
| 205 | listener->context, listener->aio_context, |
| 206 | caller); |
| 207 | for (i = 0; i < listener->nsioc; i++) { |
| 208 | if (!listener->aio_context) { |
| 209 | if (listener->source[i]->io_source) { |
| 210 | g_source_destroy(listener->source[i]->io_source); |
| 211 | g_source_unref(listener->source[i]->io_source); |
| 212 | listener->source[i]->io_source = NULL; |
| 213 | } |
| 214 | } else { |
| 215 | assert(listener->context == NULL); |
| 216 | qio_channel_set_aio_fd_handler( |
| 217 | QIO_CHANNEL(listener->source[i]->sioc), |
| 218 | listener->aio_context, NULL, NULL, NULL, NULL); |
| 219 | if (i == listener->nsioc - 1) { |
| 220 | object_unref(OBJECT(listener)); |
| 221 | } |
| 222 | } |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | void qio_net_listener_add(QIONetListener *listener, |
| 227 | QIOChannelSocket *sioc) |
| 228 | { |
| 229 | if (listener->name) { |
| 230 | qio_channel_set_name(QIO_CHANNEL(sioc), listener->name); |
| 231 | } |
| 232 | |
| 233 | listener->source = g_renew(typeof(listener->source[0]), |
| 234 | listener->source, |
| 235 | listener->nsioc + 1); |
| 236 | listener->source[listener->nsioc] = g_new0(QIONetListenerSource, 1); |
| 237 | listener->source[listener->nsioc]->sioc = sioc; |
| 238 | listener->source[listener->nsioc]->listener = listener; |
| 239 | |
| 240 | object_ref(OBJECT(sioc)); |
| 241 | listener->connected = true; |
| 242 | |
| 243 | QEMU_LOCK_GUARD(&listener->lock); |
| 244 | listener->nsioc++; |
| 245 | qio_net_listener_watch(listener, listener->nsioc - 1, "add"); |
| 246 | } |
| 247 | |
| 248 | |
| 249 | static void |
| 250 | qio_net_listener_set_client_func_internal(QIONetListener *listener, |
| 251 | QIONetListenerClientFunc func, |
| 252 | gpointer data, |
| 253 | GDestroyNotify notify, |
| 254 | GMainContext *context, |
| 255 | AioContext *aio_context) |
| 256 | { |
| 257 | QEMU_LOCK_GUARD(&listener->lock); |
| 258 | if (listener->io_func == func && listener->io_data == data && |
| 259 | listener->io_notify == notify && listener->context == context && |
| 260 | listener->aio_context == aio_context) { |
| 261 | return; |
| 262 | } |
| 263 | |
| 264 | qio_net_listener_unwatch(listener, "set_client_func"); |
| 265 | if (listener->io_notify) { |
| 266 | listener->io_notify(listener->io_data); |
| 267 | } |
| 268 | listener->io_func = func; |
| 269 | listener->io_data = data; |
| 270 | listener->io_notify = notify; |
| 271 | listener->context = context; |
| 272 | listener->aio_context = aio_context; |
| 273 | |
| 274 | qio_net_listener_watch(listener, 0, "set_client_func"); |
| 275 | } |
| 276 | |
| 277 | void qio_net_listener_set_client_func_full(QIONetListener *listener, |
| 278 | QIONetListenerClientFunc func, |
| 279 | gpointer data, |
| 280 | GDestroyNotify notify, |
| 281 | GMainContext *context) |
| 282 | { |
| 283 | qio_net_listener_set_client_func_internal(listener, func, data, |
| 284 | notify, context, NULL); |
| 285 | } |
| 286 | |
| 287 | void qio_net_listener_set_client_func(QIONetListener *listener, |
| 288 | QIONetListenerClientFunc func, |
| 289 | gpointer data, |
| 290 | GDestroyNotify notify) |
| 291 | { |
| 292 | qio_net_listener_set_client_func_internal(listener, func, data, |
| 293 | notify, NULL, NULL); |
| 294 | } |
| 295 | |
| 296 | void qio_net_listener_set_client_aio_func(QIONetListener *listener, |
| 297 | QIONetListenerClientFunc func, |
| 298 | void *data, |
| 299 | AioContext *context) |
| 300 | { |
| 301 | if (!context) { |
| 302 | assert(qemu_in_main_thread()); |
| 303 | context = qemu_get_aio_context(); |
| 304 | } else { |
| 305 | /* |
| 306 | * TODO: The API was intentionally designed to allow a caller |
| 307 | * to pass an alternative AioContext for future expansion; |
| 308 | * however, actually implementating that is not possible |
| 309 | * without notify callbacks wired into AioContext similar to |
| 310 | * how they work in GSource. So for now, this code hard-codes |
| 311 | * the knowledge that the only client needing AioContext is |
| 312 | * the NBD server, which uses the global context and does not |
| 313 | * suffer from cross-thread safety issues. |
| 314 | */ |
| 315 | g_assert_not_reached(); |
| 316 | } |
| 317 | qio_net_listener_set_client_func_internal(listener, func, data, |
| 318 | NULL, NULL, context); |
| 319 | } |
| 320 | |
| 321 | struct QIONetListenerClientWaitData { |
| 322 | QIOChannelSocket *sioc; |
| 323 | GMainLoop *loop; |
| 324 | }; |
| 325 | |
| 326 | |
| 327 | static gboolean qio_net_listener_wait_client_func(QIOChannel *ioc, |
| 328 | GIOCondition condition, |
| 329 | gpointer opaque) |
| 330 | { |
| 331 | struct QIONetListenerClientWaitData *data = opaque; |
| 332 | QIOChannelSocket *sioc; |
| 333 | |
| 334 | sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), |
| 335 | NULL); |
| 336 | if (!sioc) { |
| 337 | return TRUE; |
| 338 | } |
| 339 | |
| 340 | if (data->sioc) { |
| 341 | object_unref(OBJECT(sioc)); |
| 342 | } else { |
| 343 | data->sioc = sioc; |
| 344 | g_main_loop_quit(data->loop); |
| 345 | } |
| 346 | |
| 347 | return TRUE; |
| 348 | } |
| 349 | |
| 350 | QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener) |
| 351 | { |
| 352 | GMainContext *ctxt = g_main_context_new(); |
| 353 | GMainLoop *loop = g_main_loop_new(ctxt, TRUE); |
| 354 | GSource **sources; |
| 355 | struct QIONetListenerClientWaitData data = { |
| 356 | .sioc = NULL, |
| 357 | .loop = loop |
| 358 | }; |
| 359 | size_t i; |
| 360 | |
| 361 | WITH_QEMU_LOCK_GUARD(&listener->lock) { |
| 362 | qio_net_listener_unwatch(listener, "wait_client"); |
| 363 | } |
| 364 | |
| 365 | sources = g_new0(GSource *, listener->nsioc); |
| 366 | for (i = 0; i < listener->nsioc; i++) { |
| 367 | sources[i] = qio_channel_create_watch( |
| 368 | QIO_CHANNEL(listener->source[i]->sioc), G_IO_IN); |
| 369 | |
| 370 | g_source_set_callback(sources[i], |
| 371 | (GSourceFunc)qio_net_listener_wait_client_func, |
| 372 | &data, |
| 373 | NULL); |
| 374 | g_source_attach(sources[i], ctxt); |
| 375 | } |
| 376 | |
| 377 | g_main_loop_run(loop); |
| 378 | |
| 379 | for (i = 0; i < listener->nsioc; i++) { |
| 380 | g_source_unref(sources[i]); |
| 381 | } |
| 382 | g_free(sources); |
| 383 | g_main_loop_unref(loop); |
| 384 | g_main_context_unref(ctxt); |
| 385 | |
| 386 | WITH_QEMU_LOCK_GUARD(&listener->lock) { |
| 387 | qio_net_listener_watch(listener, 0, "wait_client"); |
| 388 | } |
| 389 | |
| 390 | return data.sioc; |
| 391 | } |
| 392 | |
| 393 | void qio_net_listener_disconnect(QIONetListener *listener) |
| 394 | { |
| 395 | size_t i; |
| 396 | |
| 397 | if (!listener->connected) { |
| 398 | return; |
| 399 | } |
| 400 | |
| 401 | QEMU_LOCK_GUARD(&listener->lock); |
| 402 | qio_net_listener_unwatch(listener, "disconnect"); |
| 403 | for (i = 0; i < listener->nsioc; i++) { |
| 404 | qio_channel_close(QIO_CHANNEL(listener->source[i]->sioc), NULL); |
| 405 | } |
| 406 | listener->connected = false; |
| 407 | } |
| 408 | |
| 409 | |
| 410 | bool qio_net_listener_is_connected(QIONetListener *listener) |
| 411 | { |
| 412 | return listener->connected; |
| 413 | } |
| 414 | |
| 415 | size_t qio_net_listener_nsioc(QIONetListener *listener) |
| 416 | { |
| 417 | return listener->nsioc; |
| 418 | } |
| 419 | |
| 420 | QIOChannelSocket *qio_net_listener_sioc(QIONetListener *listener, size_t n) |
| 421 | { |
| 422 | if (n >= listener->nsioc) { |
| 423 | return NULL; |
| 424 | } |
| 425 | return listener->source[n]->sioc; |
| 426 | } |
| 427 | |
| 428 | SocketAddress * |
| 429 | qio_net_listener_get_local_address(QIONetListener *listener, size_t n, |
| 430 | Error **errp) |
| 431 | { |
| 432 | QIOChannelSocket *sioc = qio_net_listener_sioc(listener, n); |
| 433 | |
| 434 | if (!sioc) { |
| 435 | error_setg(errp, "Listener index out of range"); |
| 436 | return NULL; |
| 437 | } |
| 438 | |
| 439 | return qio_channel_socket_get_local_address(sioc, errp); |
| 440 | } |
| 441 | |
| 442 | static void qio_net_listener_instance_init(Object *obj) |
| 443 | { |
| 444 | QIONetListener *listener = QIO_NET_LISTENER(obj); |
| 445 | |
| 446 | qemu_mutex_init(&listener->lock); |
| 447 | } |
| 448 | |
| 449 | static void qio_net_listener_finalize(Object *obj) |
| 450 | { |
| 451 | QIONetListener *listener = QIO_NET_LISTENER(obj); |
| 452 | size_t i; |
| 453 | |
| 454 | qio_net_listener_disconnect(listener); |
| 455 | if (listener->io_notify) { |
| 456 | listener->io_notify(listener->io_data); |
| 457 | } |
| 458 | |
| 459 | for (i = 0; i < listener->nsioc; i++) { |
| 460 | object_unref(OBJECT(listener->source[i]->sioc)); |
| 461 | g_free(listener->source[i]); |
| 462 | } |
| 463 | g_free(listener->source); |
| 464 | g_free(listener->name); |
| 465 | qemu_mutex_destroy(&listener->lock); |
| 466 | } |
| 467 | |
| 468 | static const TypeInfo qio_net_listener_info = { |
| 469 | .parent = TYPE_OBJECT, |
| 470 | .name = TYPE_QIO_NET_LISTENER, |
| 471 | .instance_size = sizeof(QIONetListener), |
| 472 | .instance_init = qio_net_listener_instance_init, |
| 473 | .instance_finalize = qio_net_listener_finalize, |
| 474 | }; |
| 475 | |
| 476 | |
| 477 | static void qio_net_listener_register_types(void) |
| 478 | { |
| 479 | type_register_static(&qio_net_listener_info); |
| 480 | } |
| 481 | |
| 482 | |
| 483 | type_init(qio_net_listener_register_types); |