| 1 | /* |
| 2 | * QEMU I/O channels |
| 3 | * |
| 4 | * Copyright (c) 2015 Red Hat, Inc. |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This library 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 GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include "qemu/osdep.h" |
| 22 | #include "qemu/aio-wait.h" |
| 23 | #include "io/channel.h" |
| 24 | #include "qapi/error.h" |
| 25 | #include "qemu/main-loop.h" |
| 26 | #include "qemu/module.h" |
| 27 | #include "qemu/iov.h" |
| 28 | |
| 29 | bool qio_channel_has_feature(QIOChannel *ioc, |
| 30 | QIOChannelFeature feature) |
| 31 | { |
| 32 | return ioc->features & (1 << feature); |
| 33 | } |
| 34 | |
| 35 | |
| 36 | void qio_channel_set_feature(QIOChannel *ioc, |
| 37 | QIOChannelFeature feature) |
| 38 | { |
| 39 | ioc->features |= (1 << feature); |
| 40 | } |
| 41 | |
| 42 | |
| 43 | void qio_channel_set_name(QIOChannel *ioc, |
| 44 | const char *name) |
| 45 | { |
| 46 | g_free(ioc->name); |
| 47 | ioc->name = g_strdup(name); |
| 48 | } |
| 49 | |
| 50 | |
| 51 | ssize_t qio_channel_readv_full(QIOChannel *ioc, |
| 52 | const struct iovec *iov, |
| 53 | size_t niov, |
| 54 | int **fds, |
| 55 | size_t *nfds, |
| 56 | int flags, |
| 57 | Error **errp) |
| 58 | { |
| 59 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 60 | |
| 61 | if ((fds || nfds) && |
| 62 | !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) { |
| 63 | error_setg_errno(errp, EINVAL, |
| 64 | "Channel does not support file descriptor passing"); |
| 65 | return -1; |
| 66 | } |
| 67 | |
| 68 | if ((flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) && |
| 69 | !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) { |
| 70 | error_setg_errno(errp, EINVAL, |
| 71 | "Channel does not support peek read"); |
| 72 | return -1; |
| 73 | } |
| 74 | |
| 75 | return klass->io_readv(ioc, iov, niov, fds, nfds, flags, errp); |
| 76 | } |
| 77 | |
| 78 | |
| 79 | ssize_t qio_channel_writev_full(QIOChannel *ioc, |
| 80 | const struct iovec *iov, |
| 81 | size_t niov, |
| 82 | int *fds, |
| 83 | size_t nfds, |
| 84 | int flags, |
| 85 | Error **errp) |
| 86 | { |
| 87 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 88 | |
| 89 | if (fds || nfds) { |
| 90 | if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) { |
| 91 | error_setg_errno(errp, EINVAL, |
| 92 | "Channel does not support file descriptor passing"); |
| 93 | return -1; |
| 94 | } |
| 95 | if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { |
| 96 | error_setg_errno(errp, EINVAL, |
| 97 | "Zero Copy does not support file descriptor passing"); |
| 98 | return -1; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | if ((flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) && |
| 103 | !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) { |
| 104 | error_setg_errno(errp, EINVAL, |
| 105 | "Requested Zero Copy feature is not available"); |
| 106 | return -1; |
| 107 | } |
| 108 | |
| 109 | return klass->io_writev(ioc, iov, niov, fds, nfds, flags, errp); |
| 110 | } |
| 111 | |
| 112 | |
| 113 | int coroutine_mixed_fn qio_channel_readv_all_eof(QIOChannel *ioc, |
| 114 | const struct iovec *iov, |
| 115 | size_t niov, |
| 116 | Error **errp) |
| 117 | { |
| 118 | return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, 0, |
| 119 | errp); |
| 120 | } |
| 121 | |
| 122 | int coroutine_mixed_fn qio_channel_readv_all(QIOChannel *ioc, |
| 123 | const struct iovec *iov, |
| 124 | size_t niov, |
| 125 | Error **errp) |
| 126 | { |
| 127 | return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp); |
| 128 | } |
| 129 | |
| 130 | int coroutine_mixed_fn qio_channel_readv_full_all_eof(QIOChannel *ioc, |
| 131 | const struct iovec *iov, |
| 132 | size_t niov, |
| 133 | int **fds, size_t *nfds, |
| 134 | int flags, |
| 135 | Error **errp) |
| 136 | { |
| 137 | int ret = -1; |
| 138 | struct iovec *local_iov = g_new(struct iovec, niov); |
| 139 | struct iovec *local_iov_head = local_iov; |
| 140 | unsigned int nlocal_iov = niov; |
| 141 | int **local_fds = fds; |
| 142 | size_t *local_nfds = nfds; |
| 143 | bool partial = false; |
| 144 | |
| 145 | if (nfds) { |
| 146 | *nfds = 0; |
| 147 | } |
| 148 | |
| 149 | if (fds) { |
| 150 | *fds = NULL; |
| 151 | } |
| 152 | |
| 153 | nlocal_iov = iov_copy(local_iov, nlocal_iov, |
| 154 | iov, niov, |
| 155 | 0, iov_size(iov, niov)); |
| 156 | |
| 157 | while ((nlocal_iov > 0) || local_fds) { |
| 158 | ssize_t len; |
| 159 | len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds, |
| 160 | local_nfds, flags, errp); |
| 161 | if (len == QIO_CHANNEL_ERR_BLOCK) { |
| 162 | qio_channel_wait_cond(ioc, G_IO_IN); |
| 163 | continue; |
| 164 | } |
| 165 | |
| 166 | if (len == 0) { |
| 167 | if (local_nfds && *local_nfds) { |
| 168 | /* |
| 169 | * Got some FDs, but no data yet. This isn't an EOF |
| 170 | * scenario (yet), so carry on to try to read data |
| 171 | * on next loop iteration |
| 172 | */ |
| 173 | goto next_iter; |
| 174 | } else if (!partial) { |
| 175 | /* No fds and no data - EOF before any data read */ |
| 176 | ret = 0; |
| 177 | goto cleanup; |
| 178 | } else { |
| 179 | len = -1; |
| 180 | error_setg(errp, |
| 181 | "Unexpected end-of-file before all data were read"); |
| 182 | /* Fallthrough into len < 0 handling */ |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | if (len < 0) { |
| 187 | /* Close any FDs we previously received */ |
| 188 | if (nfds && fds) { |
| 189 | size_t i; |
| 190 | for (i = 0; i < (*nfds); i++) { |
| 191 | close((*fds)[i]); |
| 192 | } |
| 193 | g_free(*fds); |
| 194 | *fds = NULL; |
| 195 | *nfds = 0; |
| 196 | } |
| 197 | goto cleanup; |
| 198 | } |
| 199 | |
| 200 | if (nlocal_iov) { |
| 201 | iov_discard_front(&local_iov, &nlocal_iov, len); |
| 202 | } |
| 203 | |
| 204 | next_iter: |
| 205 | partial = true; |
| 206 | local_fds = NULL; |
| 207 | local_nfds = NULL; |
| 208 | } |
| 209 | |
| 210 | ret = 1; |
| 211 | |
| 212 | cleanup: |
| 213 | g_free(local_iov_head); |
| 214 | return ret; |
| 215 | } |
| 216 | |
| 217 | int coroutine_mixed_fn qio_channel_readv_full_all(QIOChannel *ioc, |
| 218 | const struct iovec *iov, |
| 219 | size_t niov, |
| 220 | int **fds, size_t *nfds, |
| 221 | Error **errp) |
| 222 | { |
| 223 | int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, 0, |
| 224 | errp); |
| 225 | |
| 226 | if (ret == 0) { |
| 227 | error_setg(errp, "Unexpected end-of-file before all data were read"); |
| 228 | return -1; |
| 229 | } |
| 230 | if (ret == 1) { |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | return ret; |
| 235 | } |
| 236 | |
| 237 | int coroutine_mixed_fn qio_channel_writev_all(QIOChannel *ioc, |
| 238 | const struct iovec *iov, |
| 239 | size_t niov, |
| 240 | Error **errp) |
| 241 | { |
| 242 | return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, 0, errp); |
| 243 | } |
| 244 | |
| 245 | int coroutine_mixed_fn qio_channel_writev_full_all(QIOChannel *ioc, |
| 246 | const struct iovec *iov, |
| 247 | size_t niov, |
| 248 | int *fds, size_t nfds, |
| 249 | int flags, Error **errp) |
| 250 | { |
| 251 | int ret = -1; |
| 252 | struct iovec *local_iov = g_new(struct iovec, niov); |
| 253 | struct iovec *local_iov_head = local_iov; |
| 254 | unsigned int nlocal_iov = niov; |
| 255 | |
| 256 | nlocal_iov = iov_copy(local_iov, nlocal_iov, |
| 257 | iov, niov, |
| 258 | 0, iov_size(iov, niov)); |
| 259 | |
| 260 | while (nlocal_iov > 0) { |
| 261 | ssize_t len; |
| 262 | |
| 263 | len = qio_channel_writev_full(ioc, local_iov, nlocal_iov, fds, |
| 264 | nfds, flags, errp); |
| 265 | |
| 266 | if (len == QIO_CHANNEL_ERR_BLOCK) { |
| 267 | qio_channel_wait_cond(ioc, G_IO_OUT); |
| 268 | continue; |
| 269 | } |
| 270 | if (len < 0) { |
| 271 | goto cleanup; |
| 272 | } |
| 273 | |
| 274 | iov_discard_front(&local_iov, &nlocal_iov, len); |
| 275 | |
| 276 | fds = NULL; |
| 277 | nfds = 0; |
| 278 | } |
| 279 | |
| 280 | ret = 0; |
| 281 | cleanup: |
| 282 | g_free(local_iov_head); |
| 283 | return ret; |
| 284 | } |
| 285 | |
| 286 | ssize_t qio_channel_readv(QIOChannel *ioc, |
| 287 | const struct iovec *iov, |
| 288 | size_t niov, |
| 289 | Error **errp) |
| 290 | { |
| 291 | return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, 0, errp); |
| 292 | } |
| 293 | |
| 294 | |
| 295 | ssize_t qio_channel_writev(QIOChannel *ioc, |
| 296 | const struct iovec *iov, |
| 297 | size_t niov, |
| 298 | Error **errp) |
| 299 | { |
| 300 | return qio_channel_writev_full(ioc, iov, niov, NULL, 0, 0, errp); |
| 301 | } |
| 302 | |
| 303 | |
| 304 | ssize_t qio_channel_read(QIOChannel *ioc, |
| 305 | void *buf, |
| 306 | size_t buflen, |
| 307 | Error **errp) |
| 308 | { |
| 309 | struct iovec iov = { .iov_base = buf, .iov_len = buflen }; |
| 310 | return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, 0, errp); |
| 311 | } |
| 312 | |
| 313 | |
| 314 | ssize_t qio_channel_write(QIOChannel *ioc, |
| 315 | const void *buf, |
| 316 | size_t buflen, |
| 317 | Error **errp) |
| 318 | { |
| 319 | struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; |
| 320 | return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, 0, errp); |
| 321 | } |
| 322 | |
| 323 | |
| 324 | int coroutine_mixed_fn qio_channel_read_all_eof(QIOChannel *ioc, |
| 325 | void *buf, |
| 326 | size_t buflen, |
| 327 | Error **errp) |
| 328 | { |
| 329 | struct iovec iov = { .iov_base = buf, .iov_len = buflen }; |
| 330 | return qio_channel_readv_all_eof(ioc, &iov, 1, errp); |
| 331 | } |
| 332 | |
| 333 | |
| 334 | int coroutine_mixed_fn qio_channel_read_all(QIOChannel *ioc, |
| 335 | void *buf, |
| 336 | size_t buflen, |
| 337 | Error **errp) |
| 338 | { |
| 339 | struct iovec iov = { .iov_base = buf, .iov_len = buflen }; |
| 340 | return qio_channel_readv_all(ioc, &iov, 1, errp); |
| 341 | } |
| 342 | |
| 343 | |
| 344 | int coroutine_mixed_fn qio_channel_write_all(QIOChannel *ioc, |
| 345 | const void *buf, |
| 346 | size_t buflen, |
| 347 | Error **errp) |
| 348 | { |
| 349 | struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; |
| 350 | return qio_channel_writev_all(ioc, &iov, 1, errp); |
| 351 | } |
| 352 | |
| 353 | |
| 354 | bool qio_channel_set_blocking(QIOChannel *ioc, |
| 355 | bool enabled, |
| 356 | Error **errp) |
| 357 | { |
| 358 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 359 | return klass->io_set_blocking(ioc, enabled, errp) == 0; |
| 360 | } |
| 361 | |
| 362 | |
| 363 | void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled) |
| 364 | { |
| 365 | ioc->follow_coroutine_ctx = enabled; |
| 366 | } |
| 367 | |
| 368 | |
| 369 | int qio_channel_close(QIOChannel *ioc, |
| 370 | Error **errp) |
| 371 | { |
| 372 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 373 | return klass->io_close(ioc, errp); |
| 374 | } |
| 375 | |
| 376 | |
| 377 | GSource *qio_channel_create_watch(QIOChannel *ioc, |
| 378 | GIOCondition condition) |
| 379 | { |
| 380 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 381 | GSource *ret = klass->io_create_watch(ioc, condition); |
| 382 | |
| 383 | if (ioc->name) { |
| 384 | g_source_set_name(ret, ioc->name); |
| 385 | } |
| 386 | |
| 387 | return ret; |
| 388 | } |
| 389 | |
| 390 | |
| 391 | void qio_channel_set_aio_fd_handler(QIOChannel *ioc, |
| 392 | AioContext *read_ctx, |
| 393 | IOHandler *io_read, |
| 394 | AioContext *write_ctx, |
| 395 | IOHandler *io_write, |
| 396 | void *opaque) |
| 397 | { |
| 398 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 399 | |
| 400 | klass->io_set_aio_fd_handler(ioc, read_ctx, io_read, write_ctx, io_write, |
| 401 | opaque); |
| 402 | } |
| 403 | |
| 404 | guint qio_channel_add_watch_full(QIOChannel *ioc, |
| 405 | GIOCondition condition, |
| 406 | QIOChannelFunc func, |
| 407 | gpointer user_data, |
| 408 | GDestroyNotify notify, |
| 409 | GMainContext *context) |
| 410 | { |
| 411 | GSource *source; |
| 412 | guint id; |
| 413 | |
| 414 | source = qio_channel_create_watch(ioc, condition); |
| 415 | |
| 416 | g_source_set_callback(source, (GSourceFunc)func, user_data, notify); |
| 417 | |
| 418 | id = g_source_attach(source, context); |
| 419 | g_source_unref(source); |
| 420 | |
| 421 | return id; |
| 422 | } |
| 423 | |
| 424 | guint qio_channel_add_watch(QIOChannel *ioc, |
| 425 | GIOCondition condition, |
| 426 | QIOChannelFunc func, |
| 427 | gpointer user_data, |
| 428 | GDestroyNotify notify) |
| 429 | { |
| 430 | return qio_channel_add_watch_full(ioc, condition, func, |
| 431 | user_data, notify, NULL); |
| 432 | } |
| 433 | |
| 434 | GSource *qio_channel_add_watch_source(QIOChannel *ioc, |
| 435 | GIOCondition condition, |
| 436 | QIOChannelFunc func, |
| 437 | gpointer user_data, |
| 438 | GDestroyNotify notify, |
| 439 | GMainContext *context) |
| 440 | { |
| 441 | GSource *source; |
| 442 | guint id; |
| 443 | |
| 444 | id = qio_channel_add_watch_full(ioc, condition, func, |
| 445 | user_data, notify, context); |
| 446 | source = g_main_context_find_source_by_id(context, id); |
| 447 | g_source_ref(source); |
| 448 | return source; |
| 449 | } |
| 450 | |
| 451 | |
| 452 | ssize_t qio_channel_pwritev(QIOChannel *ioc, const struct iovec *iov, |
| 453 | size_t niov, off_t offset, Error **errp) |
| 454 | { |
| 455 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 456 | |
| 457 | if (!klass->io_pwritev) { |
| 458 | error_setg(errp, "Channel does not support pwritev"); |
| 459 | return -1; |
| 460 | } |
| 461 | |
| 462 | if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) { |
| 463 | error_setg_errno(errp, EINVAL, "Requested channel is not seekable"); |
| 464 | return -1; |
| 465 | } |
| 466 | |
| 467 | return klass->io_pwritev(ioc, iov, niov, offset, errp); |
| 468 | } |
| 469 | |
| 470 | ssize_t qio_channel_pwrite(QIOChannel *ioc, void *buf, size_t buflen, |
| 471 | off_t offset, Error **errp) |
| 472 | { |
| 473 | struct iovec iov = { |
| 474 | .iov_base = buf, |
| 475 | .iov_len = buflen |
| 476 | }; |
| 477 | |
| 478 | return qio_channel_pwritev(ioc, &iov, 1, offset, errp); |
| 479 | } |
| 480 | |
| 481 | int coroutine_mixed_fn qio_channel_pwritev_all(QIOChannel *ioc, |
| 482 | const struct iovec *iov, |
| 483 | size_t niov, |
| 484 | off_t offset, |
| 485 | Error **errp) |
| 486 | { |
| 487 | int ret = -1; |
| 488 | struct iovec *local_iov = g_new(struct iovec, niov); |
| 489 | struct iovec *local_iov_head = local_iov; |
| 490 | unsigned int nlocal_iov = niov; |
| 491 | |
| 492 | nlocal_iov = iov_copy(local_iov, nlocal_iov, |
| 493 | iov, niov, |
| 494 | 0, iov_size(iov, niov)); |
| 495 | |
| 496 | while (nlocal_iov > 0) { |
| 497 | ssize_t len; |
| 498 | |
| 499 | len = qio_channel_pwritev(ioc, local_iov, nlocal_iov, offset, errp); |
| 500 | |
| 501 | if (len == QIO_CHANNEL_ERR_BLOCK) { |
| 502 | qio_channel_wait_cond(ioc, G_IO_OUT); |
| 503 | continue; |
| 504 | } |
| 505 | if (len < 0) { |
| 506 | goto cleanup; |
| 507 | } |
| 508 | |
| 509 | offset += len; |
| 510 | iov_discard_front(&local_iov, &nlocal_iov, len); |
| 511 | } |
| 512 | |
| 513 | ret = 0; |
| 514 | cleanup: |
| 515 | g_free(local_iov_head); |
| 516 | return ret; |
| 517 | } |
| 518 | |
| 519 | int coroutine_mixed_fn qio_channel_pwrite_all(QIOChannel *ioc, |
| 520 | const void *buf, |
| 521 | size_t buflen, |
| 522 | off_t offset, |
| 523 | Error **errp) |
| 524 | { |
| 525 | struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; |
| 526 | return qio_channel_pwritev_all(ioc, &iov, 1, offset, errp); |
| 527 | } |
| 528 | |
| 529 | ssize_t qio_channel_preadv(QIOChannel *ioc, const struct iovec *iov, |
| 530 | size_t niov, off_t offset, Error **errp) |
| 531 | { |
| 532 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 533 | |
| 534 | if (!klass->io_preadv) { |
| 535 | error_setg(errp, "Channel does not support preadv"); |
| 536 | return -1; |
| 537 | } |
| 538 | |
| 539 | if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) { |
| 540 | error_setg_errno(errp, EINVAL, "Requested channel is not seekable"); |
| 541 | return -1; |
| 542 | } |
| 543 | |
| 544 | return klass->io_preadv(ioc, iov, niov, offset, errp); |
| 545 | } |
| 546 | |
| 547 | ssize_t qio_channel_pread(QIOChannel *ioc, void *buf, size_t buflen, |
| 548 | off_t offset, Error **errp) |
| 549 | { |
| 550 | struct iovec iov = { |
| 551 | .iov_base = buf, |
| 552 | .iov_len = buflen |
| 553 | }; |
| 554 | |
| 555 | return qio_channel_preadv(ioc, &iov, 1, offset, errp); |
| 556 | } |
| 557 | |
| 558 | int coroutine_mixed_fn qio_channel_preadv_all_eof(QIOChannel *ioc, |
| 559 | const struct iovec *iov, |
| 560 | size_t niov, |
| 561 | off_t offset, |
| 562 | Error **errp) |
| 563 | { |
| 564 | int ret = -1; |
| 565 | struct iovec *local_iov = g_new(struct iovec, niov); |
| 566 | struct iovec *local_iov_head = local_iov; |
| 567 | unsigned int nlocal_iov = niov; |
| 568 | bool partial = false; |
| 569 | |
| 570 | nlocal_iov = iov_copy(local_iov, nlocal_iov, |
| 571 | iov, niov, |
| 572 | 0, iov_size(iov, niov)); |
| 573 | |
| 574 | while (nlocal_iov > 0) { |
| 575 | ssize_t len; |
| 576 | len = qio_channel_preadv(ioc, local_iov, nlocal_iov, offset, errp); |
| 577 | |
| 578 | if (len == QIO_CHANNEL_ERR_BLOCK) { |
| 579 | qio_channel_wait_cond(ioc, G_IO_IN); |
| 580 | continue; |
| 581 | } |
| 582 | |
| 583 | if (len == 0) { |
| 584 | if (!partial) { |
| 585 | ret = 0; |
| 586 | goto cleanup; |
| 587 | } |
| 588 | error_setg(errp, |
| 589 | "Unexpected end-of-file before all data were read"); |
| 590 | goto cleanup; |
| 591 | } |
| 592 | |
| 593 | if (len < 0) { |
| 594 | goto cleanup; |
| 595 | } |
| 596 | |
| 597 | partial = true; |
| 598 | offset += len; |
| 599 | iov_discard_front(&local_iov, &nlocal_iov, len); |
| 600 | } |
| 601 | |
| 602 | ret = 1; |
| 603 | |
| 604 | cleanup: |
| 605 | g_free(local_iov_head); |
| 606 | return ret; |
| 607 | } |
| 608 | |
| 609 | int coroutine_mixed_fn qio_channel_preadv_all(QIOChannel *ioc, |
| 610 | const struct iovec *iov, |
| 611 | size_t niov, |
| 612 | off_t offset, |
| 613 | Error **errp) |
| 614 | { |
| 615 | int ret = qio_channel_preadv_all_eof(ioc, iov, niov, offset, errp); |
| 616 | |
| 617 | if (ret == 0) { |
| 618 | error_setg(errp, |
| 619 | "Unexpected end-of-file before all data were read"); |
| 620 | return -1; |
| 621 | } |
| 622 | if (ret == 1) { |
| 623 | return 0; |
| 624 | } |
| 625 | |
| 626 | return ret; |
| 627 | } |
| 628 | |
| 629 | int coroutine_mixed_fn qio_channel_pread_all_eof(QIOChannel *ioc, |
| 630 | void *buf, |
| 631 | size_t buflen, |
| 632 | off_t offset, |
| 633 | Error **errp) |
| 634 | { |
| 635 | struct iovec iov = { .iov_base = buf, .iov_len = buflen }; |
| 636 | return qio_channel_preadv_all_eof(ioc, &iov, 1, offset, errp); |
| 637 | } |
| 638 | |
| 639 | int coroutine_mixed_fn qio_channel_pread_all(QIOChannel *ioc, |
| 640 | void *buf, |
| 641 | size_t buflen, |
| 642 | off_t offset, |
| 643 | Error **errp) |
| 644 | { |
| 645 | struct iovec iov = { .iov_base = buf, .iov_len = buflen }; |
| 646 | return qio_channel_preadv_all(ioc, &iov, 1, offset, errp); |
| 647 | } |
| 648 | |
| 649 | int qio_channel_shutdown(QIOChannel *ioc, |
| 650 | QIOChannelShutdown how, |
| 651 | Error **errp) |
| 652 | { |
| 653 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 654 | |
| 655 | if (!klass->io_shutdown) { |
| 656 | error_setg(errp, "Data path shutdown not supported"); |
| 657 | return -1; |
| 658 | } |
| 659 | |
| 660 | return klass->io_shutdown(ioc, how, errp); |
| 661 | } |
| 662 | |
| 663 | |
| 664 | void qio_channel_set_delay(QIOChannel *ioc, |
| 665 | bool enabled) |
| 666 | { |
| 667 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 668 | |
| 669 | if (klass->io_set_delay) { |
| 670 | klass->io_set_delay(ioc, enabled); |
| 671 | } |
| 672 | } |
| 673 | |
| 674 | |
| 675 | void qio_channel_set_cork(QIOChannel *ioc, |
| 676 | bool enabled) |
| 677 | { |
| 678 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 679 | |
| 680 | if (klass->io_set_cork) { |
| 681 | klass->io_set_cork(ioc, enabled); |
| 682 | } |
| 683 | } |
| 684 | |
| 685 | int qio_channel_get_peerpid(QIOChannel *ioc, |
| 686 | unsigned int *pid, |
| 687 | Error **errp) |
| 688 | { |
| 689 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 690 | |
| 691 | if (!klass->io_peerpid) { |
| 692 | error_setg(errp, "Channel does not support peer pid"); |
| 693 | return -1; |
| 694 | } |
| 695 | klass->io_peerpid(ioc, pid, errp); |
| 696 | return 0; |
| 697 | } |
| 698 | |
| 699 | off_t qio_channel_io_seek(QIOChannel *ioc, |
| 700 | off_t offset, |
| 701 | int whence, |
| 702 | Error **errp) |
| 703 | { |
| 704 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 705 | |
| 706 | if (!klass->io_seek) { |
| 707 | error_setg(errp, "Channel does not support random access"); |
| 708 | return -1; |
| 709 | } |
| 710 | |
| 711 | return klass->io_seek(ioc, offset, whence, errp); |
| 712 | } |
| 713 | |
| 714 | int qio_channel_flush(QIOChannel *ioc, |
| 715 | Error **errp) |
| 716 | { |
| 717 | QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); |
| 718 | |
| 719 | if (!klass->io_flush || |
| 720 | !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) { |
| 721 | return 0; |
| 722 | } |
| 723 | |
| 724 | return klass->io_flush(ioc, errp); |
| 725 | } |
| 726 | |
| 727 | |
| 728 | static void qio_channel_restart_read(void *opaque) |
| 729 | { |
| 730 | QIOChannel *ioc = opaque; |
| 731 | Coroutine *co = qatomic_xchg(&ioc->read_coroutine, NULL); |
| 732 | |
| 733 | if (!co) { |
| 734 | return; |
| 735 | } |
| 736 | |
| 737 | /* Assert that aio_co_wake() reenters the coroutine directly */ |
| 738 | assert(qemu_get_current_aio_context() == |
| 739 | qemu_coroutine_get_aio_context(co)); |
| 740 | aio_co_wake(co); |
| 741 | } |
| 742 | |
| 743 | static void qio_channel_restart_write(void *opaque) |
| 744 | { |
| 745 | QIOChannel *ioc = opaque; |
| 746 | Coroutine *co = qatomic_xchg(&ioc->write_coroutine, NULL); |
| 747 | |
| 748 | if (!co) { |
| 749 | return; |
| 750 | } |
| 751 | |
| 752 | /* Assert that aio_co_wake() reenters the coroutine directly */ |
| 753 | assert(qemu_get_current_aio_context() == |
| 754 | qemu_coroutine_get_aio_context(co)); |
| 755 | aio_co_wake(co); |
| 756 | } |
| 757 | |
| 758 | static void coroutine_fn |
| 759 | qio_channel_set_fd_handlers(QIOChannel *ioc, GIOCondition condition) |
| 760 | { |
| 761 | AioContext *ctx = ioc->follow_coroutine_ctx ? |
| 762 | qemu_coroutine_get_aio_context(qemu_coroutine_self()) : |
| 763 | iohandler_get_aio_context(); |
| 764 | AioContext *read_ctx = NULL; |
| 765 | IOHandler *io_read = NULL; |
| 766 | AioContext *write_ctx = NULL; |
| 767 | IOHandler *io_write = NULL; |
| 768 | |
| 769 | if (condition == G_IO_IN) { |
| 770 | ioc->read_coroutine = qemu_coroutine_self(); |
| 771 | ioc->read_ctx = ctx; |
| 772 | read_ctx = ctx; |
| 773 | io_read = qio_channel_restart_read; |
| 774 | |
| 775 | /* |
| 776 | * Thread safety: if the other coroutine is set and its AioContext |
| 777 | * matches ours, then there is mutual exclusion between read and write |
| 778 | * because they share a single thread and it's safe to set both read |
| 779 | * and write fd handlers here. If the AioContext does not match ours, |
| 780 | * then both threads may run in parallel but there is no shared state |
| 781 | * to worry about. |
| 782 | */ |
| 783 | if (ioc->write_coroutine && ioc->write_ctx == ctx) { |
| 784 | write_ctx = ctx; |
| 785 | io_write = qio_channel_restart_write; |
| 786 | } |
| 787 | } else if (condition == G_IO_OUT) { |
| 788 | ioc->write_coroutine = qemu_coroutine_self(); |
| 789 | ioc->write_ctx = ctx; |
| 790 | write_ctx = ctx; |
| 791 | io_write = qio_channel_restart_write; |
| 792 | if (ioc->read_coroutine && ioc->read_ctx == ctx) { |
| 793 | read_ctx = ctx; |
| 794 | io_read = qio_channel_restart_read; |
| 795 | } |
| 796 | } else { |
| 797 | abort(); |
| 798 | } |
| 799 | |
| 800 | qio_channel_set_aio_fd_handler(ioc, read_ctx, io_read, |
| 801 | write_ctx, io_write, ioc); |
| 802 | } |
| 803 | |
| 804 | static void coroutine_fn |
| 805 | qio_channel_clear_fd_handlers(QIOChannel *ioc, GIOCondition condition) |
| 806 | { |
| 807 | AioContext *read_ctx = NULL; |
| 808 | IOHandler *io_read = NULL; |
| 809 | AioContext *write_ctx = NULL; |
| 810 | IOHandler *io_write = NULL; |
| 811 | AioContext *ctx; |
| 812 | |
| 813 | if (condition == G_IO_IN) { |
| 814 | ctx = ioc->read_ctx; |
| 815 | read_ctx = ctx; |
| 816 | io_read = NULL; |
| 817 | if (ioc->write_coroutine && ioc->write_ctx == ctx) { |
| 818 | write_ctx = ctx; |
| 819 | io_write = qio_channel_restart_write; |
| 820 | } |
| 821 | } else if (condition == G_IO_OUT) { |
| 822 | ctx = ioc->write_ctx; |
| 823 | write_ctx = ctx; |
| 824 | io_write = NULL; |
| 825 | if (ioc->read_coroutine && ioc->read_ctx == ctx) { |
| 826 | read_ctx = ctx; |
| 827 | io_read = qio_channel_restart_read; |
| 828 | } |
| 829 | } else { |
| 830 | abort(); |
| 831 | } |
| 832 | |
| 833 | qio_channel_set_aio_fd_handler(ioc, read_ctx, io_read, |
| 834 | write_ctx, io_write, ioc); |
| 835 | } |
| 836 | |
| 837 | void coroutine_fn qio_channel_yield(QIOChannel *ioc, |
| 838 | GIOCondition condition) |
| 839 | { |
| 840 | AioContext *ioc_ctx; |
| 841 | |
| 842 | assert(qemu_in_coroutine()); |
| 843 | ioc_ctx = qemu_coroutine_get_aio_context(qemu_coroutine_self()); |
| 844 | |
| 845 | if (condition == G_IO_IN) { |
| 846 | assert(!ioc->read_coroutine); |
| 847 | } else if (condition == G_IO_OUT) { |
| 848 | assert(!ioc->write_coroutine); |
| 849 | } else { |
| 850 | abort(); |
| 851 | } |
| 852 | qio_channel_set_fd_handlers(ioc, condition); |
| 853 | qemu_coroutine_yield(); |
| 854 | assert(in_aio_context_home_thread(ioc_ctx)); |
| 855 | |
| 856 | /* Allow interrupting the operation by reentering the coroutine other than |
| 857 | * through the aio_fd_handlers. */ |
| 858 | if (condition == G_IO_IN) { |
| 859 | assert(ioc->read_coroutine == NULL); |
| 860 | } else if (condition == G_IO_OUT) { |
| 861 | assert(ioc->write_coroutine == NULL); |
| 862 | } |
| 863 | qio_channel_clear_fd_handlers(ioc, condition); |
| 864 | } |
| 865 | |
| 866 | void qio_channel_wake_read(QIOChannel *ioc) |
| 867 | { |
| 868 | Coroutine *co = qatomic_xchg(&ioc->read_coroutine, NULL); |
| 869 | if (co) { |
| 870 | aio_co_wake(co); |
| 871 | } |
| 872 | } |
| 873 | |
| 874 | static gboolean qio_channel_wait_complete(QIOChannel *ioc, |
| 875 | GIOCondition condition, |
| 876 | gpointer opaque) |
| 877 | { |
| 878 | GMainLoop *loop = opaque; |
| 879 | |
| 880 | g_main_loop_quit(loop); |
| 881 | return FALSE; |
| 882 | } |
| 883 | |
| 884 | |
| 885 | void qio_channel_wait(QIOChannel *ioc, |
| 886 | GIOCondition condition) |
| 887 | { |
| 888 | GMainContext *ctxt = g_main_context_new(); |
| 889 | GMainLoop *loop = g_main_loop_new(ctxt, TRUE); |
| 890 | GSource *source; |
| 891 | |
| 892 | source = qio_channel_create_watch(ioc, condition); |
| 893 | |
| 894 | g_source_set_callback(source, |
| 895 | (GSourceFunc)qio_channel_wait_complete, |
| 896 | loop, |
| 897 | NULL); |
| 898 | |
| 899 | g_source_attach(source, ctxt); |
| 900 | |
| 901 | g_main_loop_run(loop); |
| 902 | |
| 903 | g_source_unref(source); |
| 904 | g_main_loop_unref(loop); |
| 905 | g_main_context_unref(ctxt); |
| 906 | } |
| 907 | |
| 908 | void coroutine_mixed_fn |
| 909 | qio_channel_wait_cond(QIOChannel *ioc, |
| 910 | GIOCondition condition) |
| 911 | { |
| 912 | if (qemu_in_coroutine()) { |
| 913 | qio_channel_yield(ioc, condition); |
| 914 | } else { |
| 915 | qio_channel_wait(ioc, condition); |
| 916 | } |
| 917 | } |
| 918 | |
| 919 | static void qio_channel_finalize(Object *obj) |
| 920 | { |
| 921 | QIOChannel *ioc = QIO_CHANNEL(obj); |
| 922 | |
| 923 | /* Must not have coroutines in qio_channel_yield() */ |
| 924 | assert(!ioc->read_coroutine); |
| 925 | assert(!ioc->write_coroutine); |
| 926 | |
| 927 | g_free(ioc->name); |
| 928 | |
| 929 | #ifdef _WIN32 |
| 930 | if (ioc->event) { |
| 931 | CloseHandle(ioc->event); |
| 932 | } |
| 933 | #endif |
| 934 | } |
| 935 | |
| 936 | static const TypeInfo qio_channel_info = { |
| 937 | .parent = TYPE_OBJECT, |
| 938 | .name = TYPE_QIO_CHANNEL, |
| 939 | .instance_size = sizeof(QIOChannel), |
| 940 | .instance_finalize = qio_channel_finalize, |
| 941 | .abstract = true, |
| 942 | .class_size = sizeof(QIOChannelClass), |
| 943 | }; |
| 944 | |
| 945 | |
| 946 | static void qio_channel_register_types(void) |
| 947 | { |
| 948 | type_register_static(&qio_channel_info); |
| 949 | } |
| 950 | |
| 951 | |
| 952 | type_init(qio_channel_register_types); |