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 | #include "qemu/osdep.h" |
25 | #include <zlib.h> |
26 | #include "qemu/error-report.h" |
27 | #include "qemu/iov.h" |
28 | #include "migration.h" |
29 | #include "qemu-file.h" |
30 | #include "trace.h" |
31 | #include "qapi/error.h" |
32 | |
33 | #define IO_BUF_SIZE 32768 |
34 | #define MAX_IOV_SIZE MIN(IOV_MAX, 64) |
35 | |
36 | struct QEMUFile { |
37 | const QEMUFileOps *ops; |
38 | const QEMUFileHooks *hooks; |
39 | void *opaque; |
40 | |
41 | int64_t bytes_xfer; |
42 | int64_t xfer_limit; |
43 | |
44 | int64_t pos; /* start of buffer when writing, end of buffer |
45 | when reading */ |
46 | int buf_index; |
47 | int buf_size; /* 0 when writing */ |
48 | uint8_t buf[IO_BUF_SIZE]; |
49 | |
50 | DECLARE_BITMAP(may_free, MAX_IOV_SIZE); |
51 | struct iovec iov[MAX_IOV_SIZE]; |
52 | unsigned int iovcnt; |
53 | |
54 | int last_error; |
55 | Error *last_error_obj; |
56 | }; |
57 | |
58 | /* |
59 | * Stop a file from being read/written - not all backing files can do this |
60 | * typically only sockets can. |
61 | */ |
62 | int qemu_file_shutdown(QEMUFile *f) |
63 | { |
64 | if (!f->ops->shut_down) { |
65 | return -ENOSYS; |
66 | } |
67 | return f->ops->shut_down(f->opaque, true, true, NULL); |
68 | } |
69 | |
70 | /* |
71 | * Result: QEMUFile* for a 'return path' for comms in the opposite direction |
72 | * NULL if not available |
73 | */ |
74 | QEMUFile *qemu_file_get_return_path(QEMUFile *f) |
75 | { |
76 | if (!f->ops->get_return_path) { |
77 | return NULL; |
78 | } |
79 | return f->ops->get_return_path(f->opaque); |
80 | } |
81 | |
82 | bool qemu_file_mode_is_not_valid(const char *mode) |
83 | { |
84 | if (mode == NULL || |
85 | (mode[0] != 'r' && mode[0] != 'w') || |
86 | mode[1] != 'b' || mode[2] != 0) { |
87 | fprintf(stderr, "qemu_fopen: Argument validity check failed\n" ); |
88 | return true; |
89 | } |
90 | |
91 | return false; |
92 | } |
93 | |
94 | QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) |
95 | { |
96 | QEMUFile *f; |
97 | |
98 | f = g_new0(QEMUFile, 1); |
99 | |
100 | f->opaque = opaque; |
101 | f->ops = ops; |
102 | return f; |
103 | } |
104 | |
105 | |
106 | void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks) |
107 | { |
108 | f->hooks = hooks; |
109 | } |
110 | |
111 | /* |
112 | * Get last error for stream f with optional Error* |
113 | * |
114 | * Return negative error value if there has been an error on previous |
115 | * operations, return 0 if no error happened. |
116 | * Optional, it returns Error* in errp, but it may be NULL even if return value |
117 | * is not 0. |
118 | * |
119 | */ |
120 | int qemu_file_get_error_obj(QEMUFile *f, Error **errp) |
121 | { |
122 | if (errp) { |
123 | *errp = f->last_error_obj ? error_copy(f->last_error_obj) : NULL; |
124 | } |
125 | return f->last_error; |
126 | } |
127 | |
128 | /* |
129 | * Set the last error for stream f with optional Error* |
130 | */ |
131 | void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err) |
132 | { |
133 | if (f->last_error == 0 && ret) { |
134 | f->last_error = ret; |
135 | error_propagate(&f->last_error_obj, err); |
136 | } else if (err) { |
137 | error_report_err(err); |
138 | } |
139 | } |
140 | |
141 | /* |
142 | * Get last error for stream f |
143 | * |
144 | * Return negative error value if there has been an error on previous |
145 | * operations, return 0 if no error happened. |
146 | * |
147 | */ |
148 | int qemu_file_get_error(QEMUFile *f) |
149 | { |
150 | return qemu_file_get_error_obj(f, NULL); |
151 | } |
152 | |
153 | /* |
154 | * Set the last error for stream f |
155 | */ |
156 | void qemu_file_set_error(QEMUFile *f, int ret) |
157 | { |
158 | qemu_file_set_error_obj(f, ret, NULL); |
159 | } |
160 | |
161 | bool qemu_file_is_writable(QEMUFile *f) |
162 | { |
163 | return f->ops->writev_buffer; |
164 | } |
165 | |
166 | static void qemu_iovec_release_ram(QEMUFile *f) |
167 | { |
168 | struct iovec iov; |
169 | unsigned long idx; |
170 | |
171 | /* Find and release all the contiguous memory ranges marked as may_free. */ |
172 | idx = find_next_bit(f->may_free, f->iovcnt, 0); |
173 | if (idx >= f->iovcnt) { |
174 | return; |
175 | } |
176 | iov = f->iov[idx]; |
177 | |
178 | /* The madvise() in the loop is called for iov within a continuous range and |
179 | * then reinitialize the iov. And in the end, madvise() is called for the |
180 | * last iov. |
181 | */ |
182 | while ((idx = find_next_bit(f->may_free, f->iovcnt, idx + 1)) < f->iovcnt) { |
183 | /* check for adjacent buffer and coalesce them */ |
184 | if (iov.iov_base + iov.iov_len == f->iov[idx].iov_base) { |
185 | iov.iov_len += f->iov[idx].iov_len; |
186 | continue; |
187 | } |
188 | if (qemu_madvise(iov.iov_base, iov.iov_len, QEMU_MADV_DONTNEED) < 0) { |
189 | error_report("migrate: madvise DONTNEED failed %p %zd: %s" , |
190 | iov.iov_base, iov.iov_len, strerror(errno)); |
191 | } |
192 | iov = f->iov[idx]; |
193 | } |
194 | if (qemu_madvise(iov.iov_base, iov.iov_len, QEMU_MADV_DONTNEED) < 0) { |
195 | error_report("migrate: madvise DONTNEED failed %p %zd: %s" , |
196 | iov.iov_base, iov.iov_len, strerror(errno)); |
197 | } |
198 | memset(f->may_free, 0, sizeof(f->may_free)); |
199 | } |
200 | |
201 | /** |
202 | * Flushes QEMUFile buffer |
203 | * |
204 | * If there is writev_buffer QEMUFileOps it uses it otherwise uses |
205 | * put_buffer ops. This will flush all pending data. If data was |
206 | * only partially flushed, it will set an error state. |
207 | */ |
208 | void qemu_fflush(QEMUFile *f) |
209 | { |
210 | ssize_t ret = 0; |
211 | ssize_t expect = 0; |
212 | Error *local_error = NULL; |
213 | |
214 | if (!qemu_file_is_writable(f)) { |
215 | return; |
216 | } |
217 | |
218 | if (f->iovcnt > 0) { |
219 | expect = iov_size(f->iov, f->iovcnt); |
220 | ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos, |
221 | &local_error); |
222 | |
223 | qemu_iovec_release_ram(f); |
224 | } |
225 | |
226 | if (ret >= 0) { |
227 | f->pos += ret; |
228 | } |
229 | /* We expect the QEMUFile write impl to send the full |
230 | * data set we requested, so sanity check that. |
231 | */ |
232 | if (ret != expect) { |
233 | qemu_file_set_error_obj(f, ret < 0 ? ret : -EIO, local_error); |
234 | } |
235 | f->buf_index = 0; |
236 | f->iovcnt = 0; |
237 | } |
238 | |
239 | void ram_control_before_iterate(QEMUFile *f, uint64_t flags) |
240 | { |
241 | int ret = 0; |
242 | |
243 | if (f->hooks && f->hooks->before_ram_iterate) { |
244 | ret = f->hooks->before_ram_iterate(f, f->opaque, flags, NULL); |
245 | if (ret < 0) { |
246 | qemu_file_set_error(f, ret); |
247 | } |
248 | } |
249 | } |
250 | |
251 | void ram_control_after_iterate(QEMUFile *f, uint64_t flags) |
252 | { |
253 | int ret = 0; |
254 | |
255 | if (f->hooks && f->hooks->after_ram_iterate) { |
256 | ret = f->hooks->after_ram_iterate(f, f->opaque, flags, NULL); |
257 | if (ret < 0) { |
258 | qemu_file_set_error(f, ret); |
259 | } |
260 | } |
261 | } |
262 | |
263 | void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data) |
264 | { |
265 | int ret = -EINVAL; |
266 | |
267 | if (f->hooks && f->hooks->hook_ram_load) { |
268 | ret = f->hooks->hook_ram_load(f, f->opaque, flags, data); |
269 | if (ret < 0) { |
270 | qemu_file_set_error(f, ret); |
271 | } |
272 | } else { |
273 | /* |
274 | * Hook is a hook specifically requested by the source sending a flag |
275 | * that expects there to be a hook on the destination. |
276 | */ |
277 | if (flags == RAM_CONTROL_HOOK) { |
278 | qemu_file_set_error(f, ret); |
279 | } |
280 | } |
281 | } |
282 | |
283 | size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset, |
284 | ram_addr_t offset, size_t size, |
285 | uint64_t *bytes_sent) |
286 | { |
287 | if (f->hooks && f->hooks->save_page) { |
288 | int ret = f->hooks->save_page(f, f->opaque, block_offset, |
289 | offset, size, bytes_sent); |
290 | if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { |
291 | f->bytes_xfer += size; |
292 | } |
293 | |
294 | if (ret != RAM_SAVE_CONTROL_DELAYED && |
295 | ret != RAM_SAVE_CONTROL_NOT_SUPP) { |
296 | if (bytes_sent && *bytes_sent > 0) { |
297 | qemu_update_position(f, *bytes_sent); |
298 | } else if (ret < 0) { |
299 | qemu_file_set_error(f, ret); |
300 | } |
301 | } |
302 | |
303 | return ret; |
304 | } |
305 | |
306 | return RAM_SAVE_CONTROL_NOT_SUPP; |
307 | } |
308 | |
309 | /* |
310 | * Attempt to fill the buffer from the underlying file |
311 | * Returns the number of bytes read, or negative value for an error. |
312 | * |
313 | * Note that it can return a partially full buffer even in a not error/not EOF |
314 | * case if the underlying file descriptor gives a short read, and that can |
315 | * happen even on a blocking fd. |
316 | */ |
317 | static ssize_t qemu_fill_buffer(QEMUFile *f) |
318 | { |
319 | int len; |
320 | int pending; |
321 | Error *local_error = NULL; |
322 | |
323 | assert(!qemu_file_is_writable(f)); |
324 | |
325 | pending = f->buf_size - f->buf_index; |
326 | if (pending > 0) { |
327 | memmove(f->buf, f->buf + f->buf_index, pending); |
328 | } |
329 | f->buf_index = 0; |
330 | f->buf_size = pending; |
331 | |
332 | len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos, |
333 | IO_BUF_SIZE - pending, &local_error); |
334 | if (len > 0) { |
335 | f->buf_size += len; |
336 | f->pos += len; |
337 | } else if (len == 0) { |
338 | qemu_file_set_error_obj(f, -EIO, local_error); |
339 | } else if (len != -EAGAIN) { |
340 | qemu_file_set_error_obj(f, len, local_error); |
341 | } else { |
342 | error_free(local_error); |
343 | } |
344 | |
345 | return len; |
346 | } |
347 | |
348 | void qemu_update_position(QEMUFile *f, size_t size) |
349 | { |
350 | f->pos += size; |
351 | } |
352 | |
353 | /** Closes the file |
354 | * |
355 | * Returns negative error value if any error happened on previous operations or |
356 | * while closing the file. Returns 0 or positive number on success. |
357 | * |
358 | * The meaning of return value on success depends on the specific backend |
359 | * being used. |
360 | */ |
361 | int qemu_fclose(QEMUFile *f) |
362 | { |
363 | int ret; |
364 | qemu_fflush(f); |
365 | ret = qemu_file_get_error(f); |
366 | |
367 | if (f->ops->close) { |
368 | int ret2 = f->ops->close(f->opaque, NULL); |
369 | if (ret >= 0) { |
370 | ret = ret2; |
371 | } |
372 | } |
373 | /* If any error was spotted before closing, we should report it |
374 | * instead of the close() return value. |
375 | */ |
376 | if (f->last_error) { |
377 | ret = f->last_error; |
378 | } |
379 | error_free(f->last_error_obj); |
380 | g_free(f); |
381 | trace_qemu_file_fclose(); |
382 | return ret; |
383 | } |
384 | |
385 | static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, |
386 | bool may_free) |
387 | { |
388 | /* check for adjacent buffer and coalesce them */ |
389 | if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base + |
390 | f->iov[f->iovcnt - 1].iov_len && |
391 | may_free == test_bit(f->iovcnt - 1, f->may_free)) |
392 | { |
393 | f->iov[f->iovcnt - 1].iov_len += size; |
394 | } else { |
395 | if (may_free) { |
396 | set_bit(f->iovcnt, f->may_free); |
397 | } |
398 | f->iov[f->iovcnt].iov_base = (uint8_t *)buf; |
399 | f->iov[f->iovcnt++].iov_len = size; |
400 | } |
401 | |
402 | if (f->iovcnt >= MAX_IOV_SIZE) { |
403 | qemu_fflush(f); |
404 | } |
405 | } |
406 | |
407 | void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size, |
408 | bool may_free) |
409 | { |
410 | if (f->last_error) { |
411 | return; |
412 | } |
413 | |
414 | f->bytes_xfer += size; |
415 | add_to_iovec(f, buf, size, may_free); |
416 | } |
417 | |
418 | void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size) |
419 | { |
420 | size_t l; |
421 | |
422 | if (f->last_error) { |
423 | return; |
424 | } |
425 | |
426 | while (size > 0) { |
427 | l = IO_BUF_SIZE - f->buf_index; |
428 | if (l > size) { |
429 | l = size; |
430 | } |
431 | memcpy(f->buf + f->buf_index, buf, l); |
432 | f->bytes_xfer += l; |
433 | add_to_iovec(f, f->buf + f->buf_index, l, false); |
434 | f->buf_index += l; |
435 | if (f->buf_index == IO_BUF_SIZE) { |
436 | qemu_fflush(f); |
437 | } |
438 | if (qemu_file_get_error(f)) { |
439 | break; |
440 | } |
441 | buf += l; |
442 | size -= l; |
443 | } |
444 | } |
445 | |
446 | void qemu_put_byte(QEMUFile *f, int v) |
447 | { |
448 | if (f->last_error) { |
449 | return; |
450 | } |
451 | |
452 | f->buf[f->buf_index] = v; |
453 | f->bytes_xfer++; |
454 | add_to_iovec(f, f->buf + f->buf_index, 1, false); |
455 | f->buf_index++; |
456 | if (f->buf_index == IO_BUF_SIZE) { |
457 | qemu_fflush(f); |
458 | } |
459 | } |
460 | |
461 | void qemu_file_skip(QEMUFile *f, int size) |
462 | { |
463 | if (f->buf_index + size <= f->buf_size) { |
464 | f->buf_index += size; |
465 | } |
466 | } |
467 | |
468 | /* |
469 | * Read 'size' bytes from file (at 'offset') without moving the |
470 | * pointer and set 'buf' to point to that data. |
471 | * |
472 | * It will return size bytes unless there was an error, in which case it will |
473 | * return as many as it managed to read (assuming blocking fd's which |
474 | * all current QEMUFile are) |
475 | */ |
476 | size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset) |
477 | { |
478 | ssize_t pending; |
479 | size_t index; |
480 | |
481 | assert(!qemu_file_is_writable(f)); |
482 | assert(offset < IO_BUF_SIZE); |
483 | assert(size <= IO_BUF_SIZE - offset); |
484 | |
485 | /* The 1st byte to read from */ |
486 | index = f->buf_index + offset; |
487 | /* The number of available bytes starting at index */ |
488 | pending = f->buf_size - index; |
489 | |
490 | /* |
491 | * qemu_fill_buffer might return just a few bytes, even when there isn't |
492 | * an error, so loop collecting them until we get enough. |
493 | */ |
494 | while (pending < size) { |
495 | int received = qemu_fill_buffer(f); |
496 | |
497 | if (received <= 0) { |
498 | break; |
499 | } |
500 | |
501 | index = f->buf_index + offset; |
502 | pending = f->buf_size - index; |
503 | } |
504 | |
505 | if (pending <= 0) { |
506 | return 0; |
507 | } |
508 | if (size > pending) { |
509 | size = pending; |
510 | } |
511 | |
512 | *buf = f->buf + index; |
513 | return size; |
514 | } |
515 | |
516 | /* |
517 | * Read 'size' bytes of data from the file into buf. |
518 | * 'size' can be larger than the internal buffer. |
519 | * |
520 | * It will return size bytes unless there was an error, in which case it will |
521 | * return as many as it managed to read (assuming blocking fd's which |
522 | * all current QEMUFile are) |
523 | */ |
524 | size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size) |
525 | { |
526 | size_t pending = size; |
527 | size_t done = 0; |
528 | |
529 | while (pending > 0) { |
530 | size_t res; |
531 | uint8_t *src; |
532 | |
533 | res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0); |
534 | if (res == 0) { |
535 | return done; |
536 | } |
537 | memcpy(buf, src, res); |
538 | qemu_file_skip(f, res); |
539 | buf += res; |
540 | pending -= res; |
541 | done += res; |
542 | } |
543 | return done; |
544 | } |
545 | |
546 | /* |
547 | * Read 'size' bytes of data from the file. |
548 | * 'size' can be larger than the internal buffer. |
549 | * |
550 | * The data: |
551 | * may be held on an internal buffer (in which case *buf is updated |
552 | * to point to it) that is valid until the next qemu_file operation. |
553 | * OR |
554 | * will be copied to the *buf that was passed in. |
555 | * |
556 | * The code tries to avoid the copy if possible. |
557 | * |
558 | * It will return size bytes unless there was an error, in which case it will |
559 | * return as many as it managed to read (assuming blocking fd's which |
560 | * all current QEMUFile are) |
561 | * |
562 | * Note: Since **buf may get changed, the caller should take care to |
563 | * keep a pointer to the original buffer if it needs to deallocate it. |
564 | */ |
565 | size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size) |
566 | { |
567 | if (size < IO_BUF_SIZE) { |
568 | size_t res; |
569 | uint8_t *src; |
570 | |
571 | res = qemu_peek_buffer(f, &src, size, 0); |
572 | |
573 | if (res == size) { |
574 | qemu_file_skip(f, res); |
575 | *buf = src; |
576 | return res; |
577 | } |
578 | } |
579 | |
580 | return qemu_get_buffer(f, *buf, size); |
581 | } |
582 | |
583 | /* |
584 | * Peeks a single byte from the buffer; this isn't guaranteed to work if |
585 | * offset leaves a gap after the previous read/peeked data. |
586 | */ |
587 | int qemu_peek_byte(QEMUFile *f, int offset) |
588 | { |
589 | int index = f->buf_index + offset; |
590 | |
591 | assert(!qemu_file_is_writable(f)); |
592 | assert(offset < IO_BUF_SIZE); |
593 | |
594 | if (index >= f->buf_size) { |
595 | qemu_fill_buffer(f); |
596 | index = f->buf_index + offset; |
597 | if (index >= f->buf_size) { |
598 | return 0; |
599 | } |
600 | } |
601 | return f->buf[index]; |
602 | } |
603 | |
604 | int qemu_get_byte(QEMUFile *f) |
605 | { |
606 | int result; |
607 | |
608 | result = qemu_peek_byte(f, 0); |
609 | qemu_file_skip(f, 1); |
610 | return result; |
611 | } |
612 | |
613 | int64_t qemu_ftell_fast(QEMUFile *f) |
614 | { |
615 | int64_t ret = f->pos; |
616 | int i; |
617 | |
618 | for (i = 0; i < f->iovcnt; i++) { |
619 | ret += f->iov[i].iov_len; |
620 | } |
621 | |
622 | return ret; |
623 | } |
624 | |
625 | int64_t qemu_ftell(QEMUFile *f) |
626 | { |
627 | qemu_fflush(f); |
628 | return f->pos; |
629 | } |
630 | |
631 | int qemu_file_rate_limit(QEMUFile *f) |
632 | { |
633 | if (qemu_file_get_error(f)) { |
634 | return 1; |
635 | } |
636 | if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) { |
637 | return 1; |
638 | } |
639 | return 0; |
640 | } |
641 | |
642 | int64_t qemu_file_get_rate_limit(QEMUFile *f) |
643 | { |
644 | return f->xfer_limit; |
645 | } |
646 | |
647 | void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit) |
648 | { |
649 | f->xfer_limit = limit; |
650 | } |
651 | |
652 | void qemu_file_reset_rate_limit(QEMUFile *f) |
653 | { |
654 | f->bytes_xfer = 0; |
655 | } |
656 | |
657 | void qemu_file_update_transfer(QEMUFile *f, int64_t len) |
658 | { |
659 | f->bytes_xfer += len; |
660 | } |
661 | |
662 | void qemu_put_be16(QEMUFile *f, unsigned int v) |
663 | { |
664 | qemu_put_byte(f, v >> 8); |
665 | qemu_put_byte(f, v); |
666 | } |
667 | |
668 | void qemu_put_be32(QEMUFile *f, unsigned int v) |
669 | { |
670 | qemu_put_byte(f, v >> 24); |
671 | qemu_put_byte(f, v >> 16); |
672 | qemu_put_byte(f, v >> 8); |
673 | qemu_put_byte(f, v); |
674 | } |
675 | |
676 | void qemu_put_be64(QEMUFile *f, uint64_t v) |
677 | { |
678 | qemu_put_be32(f, v >> 32); |
679 | qemu_put_be32(f, v); |
680 | } |
681 | |
682 | unsigned int qemu_get_be16(QEMUFile *f) |
683 | { |
684 | unsigned int v; |
685 | v = qemu_get_byte(f) << 8; |
686 | v |= qemu_get_byte(f); |
687 | return v; |
688 | } |
689 | |
690 | unsigned int qemu_get_be32(QEMUFile *f) |
691 | { |
692 | unsigned int v; |
693 | v = (unsigned int)qemu_get_byte(f) << 24; |
694 | v |= qemu_get_byte(f) << 16; |
695 | v |= qemu_get_byte(f) << 8; |
696 | v |= qemu_get_byte(f); |
697 | return v; |
698 | } |
699 | |
700 | uint64_t qemu_get_be64(QEMUFile *f) |
701 | { |
702 | uint64_t v; |
703 | v = (uint64_t)qemu_get_be32(f) << 32; |
704 | v |= qemu_get_be32(f); |
705 | return v; |
706 | } |
707 | |
708 | /* return the size after compression, or negative value on error */ |
709 | static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len, |
710 | const uint8_t *source, size_t source_len) |
711 | { |
712 | int err; |
713 | |
714 | err = deflateReset(stream); |
715 | if (err != Z_OK) { |
716 | return -1; |
717 | } |
718 | |
719 | stream->avail_in = source_len; |
720 | stream->next_in = (uint8_t *)source; |
721 | stream->avail_out = dest_len; |
722 | stream->next_out = dest; |
723 | |
724 | err = deflate(stream, Z_FINISH); |
725 | if (err != Z_STREAM_END) { |
726 | return -1; |
727 | } |
728 | |
729 | return stream->next_out - dest; |
730 | } |
731 | |
732 | /* Compress size bytes of data start at p and store the compressed |
733 | * data to the buffer of f. |
734 | * |
735 | * When f is not writable, return -1 if f has no space to save the |
736 | * compressed data. |
737 | * When f is wirtable and it has no space to save the compressed data, |
738 | * do fflush first, if f still has no space to save the compressed |
739 | * data, return -1. |
740 | */ |
741 | ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, |
742 | const uint8_t *p, size_t size) |
743 | { |
744 | ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t); |
745 | |
746 | if (blen < compressBound(size)) { |
747 | if (!qemu_file_is_writable(f)) { |
748 | return -1; |
749 | } |
750 | qemu_fflush(f); |
751 | blen = IO_BUF_SIZE - sizeof(int32_t); |
752 | if (blen < compressBound(size)) { |
753 | return -1; |
754 | } |
755 | } |
756 | |
757 | blen = qemu_compress_data(stream, f->buf + f->buf_index + sizeof(int32_t), |
758 | blen, p, size); |
759 | if (blen < 0) { |
760 | return -1; |
761 | } |
762 | |
763 | qemu_put_be32(f, blen); |
764 | if (f->ops->writev_buffer) { |
765 | add_to_iovec(f, f->buf + f->buf_index, blen, false); |
766 | } |
767 | f->buf_index += blen; |
768 | if (f->buf_index == IO_BUF_SIZE) { |
769 | qemu_fflush(f); |
770 | } |
771 | return blen + sizeof(int32_t); |
772 | } |
773 | |
774 | /* Put the data in the buffer of f_src to the buffer of f_des, and |
775 | * then reset the buf_index of f_src to 0. |
776 | */ |
777 | |
778 | int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src) |
779 | { |
780 | int len = 0; |
781 | |
782 | if (f_src->buf_index > 0) { |
783 | len = f_src->buf_index; |
784 | qemu_put_buffer(f_des, f_src->buf, f_src->buf_index); |
785 | f_src->buf_index = 0; |
786 | f_src->iovcnt = 0; |
787 | } |
788 | return len; |
789 | } |
790 | |
791 | /* |
792 | * Get a string whose length is determined by a single preceding byte |
793 | * A preallocated 256 byte buffer must be passed in. |
794 | * Returns: len on success and a 0 terminated string in the buffer |
795 | * else 0 |
796 | * (Note a 0 length string will return 0 either way) |
797 | */ |
798 | size_t qemu_get_counted_string(QEMUFile *f, char buf[256]) |
799 | { |
800 | size_t len = qemu_get_byte(f); |
801 | size_t res = qemu_get_buffer(f, (uint8_t *)buf, len); |
802 | |
803 | buf[res] = 0; |
804 | |
805 | return res == len ? res : 0; |
806 | } |
807 | |
808 | /* |
809 | * Put a string with one preceding byte containing its length. The length of |
810 | * the string should be less than 256. |
811 | */ |
812 | void qemu_put_counted_string(QEMUFile *f, const char *str) |
813 | { |
814 | size_t len = strlen(str); |
815 | |
816 | assert(len < 256); |
817 | qemu_put_byte(f, len); |
818 | qemu_put_buffer(f, (const uint8_t *)str, len); |
819 | } |
820 | |
821 | /* |
822 | * Set the blocking state of the QEMUFile. |
823 | * Note: On some transports the OS only keeps a single blocking state for |
824 | * both directions, and thus changing the blocking on the main |
825 | * QEMUFile can also affect the return path. |
826 | */ |
827 | void qemu_file_set_blocking(QEMUFile *f, bool block) |
828 | { |
829 | if (f->ops->set_blocking) { |
830 | f->ops->set_blocking(f->opaque, block, NULL); |
831 | } |
832 | } |
833 | |